Inhibition of yeast ribonucleic acid polymerases by thiolutin. Yeast ribonucleic acid (RNA) polymerase II, isolated after fractionation on diethylaminoethyl (DEAE)-cellulose (DE-52) or on DEAE-Sephadex (A-25), is 50% inhibited by 1.5 mug of alpha-amanitin. This inhibition is independent of the sequence of interaction of enzyme, template, nucleotides, and antibiotic and is expressed immediately on addition of alpha-amanitin to a preparation actively synthesizing RNA. Thus, alpha-amanitin's primary effect is inhibition of elongation of preinitiated RNA sequences in this system, as in others. A single peak of alpha-amanitin-resistant RNA polymerase activity (I) was eluted before enzyme II on either column. On A-25 but not on DE-52, a third peak of activity (III) was eluted after enzyme II. This activity was also resistant to alpha-amanitin. Enzymes I, II, and III were 50% inhibited by 3, 4, and 3 mug of thiolutin per ml, respectively. The extent of inhibition was independent of the nature of the template (native or denatured salmon sperm deoxyribonucleic acid or poly(dA-dT) or of the presence of 0.4 mM dithiothreitol, but this marked inhibition was only seen when enzymes were preincubated with thiolutin in the absence of template. Template protected the enzymes against thiolutin in the absence of nucleotides. Either the sensitive site on the polymerase is only accessible to thiolutin before interaction with template or thiolutin inhibits functional polymerase-template interaction but not elongation of preinitiated RNA chains.


Effects of external osmolarity on phospholipid metabolism in Escherichia coli B. The turnover of total [(32)P]phospholipids in Escherichia coli B is shown to be inversely related to the osmolarity of the medium and a reflection of the rates of turnover of the major phospholipid classes, phosphatidylglycerol and phosphatidylethanolamine. External osmolarity also affects the phosphatidylglycerol content of the culture. These results suggest that alterations in the metabolism of membrane phospholipids may be part of the process of adaptation to the external osmotic environment.


Growth in high osmotic medium of an unsaturated fatty acid auxotroph of Escherichia coli K-12. A temperature-sensitive mutant of Escherichia coli K-12, which is impaired in the biosynthesis of the unsaturated fatty acids at 42 C, continues to grow and remains viable in a medium with a high osmotic pressure. Under these growth conditions, 50% of the fatty acids of the parental strain and 80% of the fatty acids of the mutant strain are saturated.


Kinetics of the mating-specific aggregation in Saccharomyces cerevisiae. Procedures are described for obtaining efficient mating (zygote formation) in the heterothallic yeast Saccharomyces cerevisiae. The methods separate operationally the initial, mating-specific aggregation from subsequent steps in conjugation. This cell-cell interaction has been characterized. The data support the conclusions that (i) aggregation in liquid suspension is a random collision process, and (ii) only non-budded cells participate in aggregation. A mathematical model for the kinetics of aggregation in liquid suspension has been developed which is in good agreement with the experimental data.


Process of cellular division in Escherichia coli: physiological study on thermosensitive mutants defective in cell division. Thermosensitive fts mutants of Escherichia coli belonging to seven previously identified genetic classes (ftsA to ftsG) were studied from a physiological standpoint. These mutants immediately stopped dividing and formed multinucleated filaments when the temperature was shifted to 41 C. Macromolecular syntheses (deoxyribonucleic acid), ribonucleic acid, cell mass, and murein) continued exponentially for at least 40 to 120 min. The number of surviving bacteria remained constant during the time of incubation, and this number began to decrease exponentially, as the rate of cell mass increase leveled off from the initial rate. The recovery of cell division at 30 C in these filamentous cells was studied after 60 min of incubation at 41 C. The existence of three types of mutants was shown. The ftsA and ftsE mutants resumed cell division without new protein synthesis; ftsD mutants resumed cell division only if new protein synthesis occured, while ftsB, C, F and G mutants did not resume cell division at all. No alteration in the cell envelope was detected by the method used here, although the ftsA, B, D, F and G mutations, in contrast with ftsC and E, caused an increased resistance to penicillin G. It was also shown that the recA mutation did not suppress the effect of the fts mutations and that none of the lysogenic fts mutants induced prophage multiplication while forming filaments. The effects of osmotic pressure and salts which rescue the mutant phenotype is described.


Duplication-translocations of tryptophan operon genes in Escherichia coli. Mutants of Escherichia coli were selected in which a single mutational event had both relieved the polar effect of an early trpE mutation on trpB and simultaneously released the expression of trpB from tryptophan repression. The frequency at which these mutations appeared was roughly equal to the frequency of point mutations. In each of these mutants, the mutation increased the function of trpB and also increased the activity of some, but not all, of the other four tryptophan operon genes. Genetic analysis showed that the mutations were not located within the trp operon since in each case the parental trp operon could be recovered from the mutants. Each mutant was shown to carry a duplication of a trp operon segment translocated to a new position near the trp operon. Polarity is relieved since the trpB duplication-translocation is not in the same operon as the trpE polar mutation. The duplicated and translocated segments are fused to operons not regulated by tryptophan, so trpB function is no longer subject to tryptophan repression. The properties of the mutants indicate that the length of the duplicated segment and the position to which it is translocated differ in each of the seven mutants studied. The duplications are unstable, but the segregation pattern observed is not consistent with a single crossover model for segregation. That such duplication-translocation events generate a variety of new genetic arrangements at a frequency comparable with point mutations suggests they may play an important role in evolution.


Glycolaldehyde is a precursor of pyridoxal phosphate in Escherichia coli B. Carbon-labeled glycolaldehyde prepared from [(14)C]serine was used to supply the nutritional requirement of a pyridoxineless auxotroph of Escherichia coli. Pyridoxal phosphate isolated from bacteria so grown was found to have incorporated the radioactive glycolaldehyde with little dilution. The radioactivity which was unincorporated into pyridoxal phosphate was recovered almost entirely in the culture fluid. The results establish for the first time that glycolaldehyde is indeed a natural precursor of pyridoxal phosphate or it is readily converted to such a precursor.


Osmotically induced excretion of putrescine by mutants of Escherichia coli defective in potassium transport. Escherichia coli is known to excrete putrescine rapidly after a sudden elevation in the osmolarity of the medium. We report here that mutants defective in the transport of potassium ions display a greatly diminished rate of [(14)C]putrescine excretion.


Lysis of Escherichia coli by glycine is potentiated by pyridoxine starvation. Pyridoxineless mutants of Escherichia coli are lysed in a few hours when starved for pyridoxine in a glucose minimal medium containing glycine at 10 mM. The lysis is prevented equally well by l-alanine and by d-alanine when either is present at 0.1 mM. The lysis is potentiated by 0.5 mM l-methionine. The peculiar susceptibility of E. coli B to glycine-mediated lysis during starvation for pyridoxine suggests that the starvation reduces the availability of some normal antagonist of glycine, presumably alanine.


Regulation of phospholipid synthesis in Escherichia coli by guanosine tetraphosphate. Phospholipid synthesis has been reported to be subject to stringent control in Escherichia coli. We present evidence that demonstrates a strict correlation between guanosine tetraphosphate accumulation and inhibition of phospholipid synthesis. In vivo experiments designed to examine the pattern of phospholipid labeling with (32)P-inorganic phosphate and (32)P-sn-glycerol-3-phosphate suggest that regulation must occur at the glycerol-3-phosphate acyltransferase step. Assay of phospholipid synthesis by cell-free extracts and semipurified preparations revealed that guanosine tetraphosphate inhibits at least two enzymes specific for the biosynthetic pathway, sn-glycerol-3-phosphate acyltransferase as well as sn-glycerol-3-phosphate phosphatidyl transferase. These findings provide a biochemical basis for the stringent control of lipid synthesis as well as regulation of steady-state levels of phospholipid in growing cells.


Degradation of cellular deoxyribonucleic acid after gamma irradiation of spheroplasted Escherichia coli CR thy- cells. Gamma-ray-irradiated Escherichia coli CR thy(-) cells and spheroplasts, prelabeled with (14)C-thymine, were assayed for acid-insoluble activity as a function of incubation time after irradiation. Under similar irradiation and incubation conditions, degradation profiles of cells and spheroplasts were virtually identical. Similar results were found for cells and protoplasts irradiated in the presence of rifampin (20 mug/ml). These results suggest that postirradiation deoxyribonucleic acid degradation enzymes are probably not loosely localized in the periplasm, unlike endonuclease I.


Biotin uptake in biotin regulatory mutant of Escherichia coli. A transport system for biotin in Escherichia coli is regulated by biotin and is not affected by the mutation (bioR) that causes the constitutive synthesis of the bio operon enzymes.


Kinetics of reaction of Escherichia coli ribosomal proteins toward N-ethylmaleimide. The kinetics of reaction of the exposed ribosomal proteins from Escherichia coli toward N-ethylmaleimide (NEM) have been studied. While most of the proteins from the 30S subunit react rapidly with NEM and plateau levels can be reached, most of the proteins from the 50S subunit show biphasic uptake kinetics. Furthermore, differences have been observed in the reactivity of proteins toward NEM depending on whether the protein is in the free subunit or in the 70S ribosome.


Mutation to erythromycin dependence in Escherichia coli K-12. A nitrosoguanidine-induced mutant of Escherichia coli K-12 strain JC12 was absolutely dependent on erythromycin or related macrolide antibiotics for growth. The only other drugs which permitted growth (lincomycin and chloramphenicol) are, like the macrolides, inhibitors of the 50S ribosome. The order of relative effectiveness of these drugs was macrolides > lincomycin > chloramphenicol. Rates of growth with all drugs were concentration dependent. Erythromycin starvation was followed by normal rates of increase in cell mass and macromolecular synthesis for approximately one mass-doubling time, after which macromolecular synthesis abruptly ceased and cell lysis and death occurred. The dependent mutant gave rise spontaneously to revertants to independence with very high frequency (10(-4)). The gene (mac) for macrolide dependence is located near minute 25 on the E. coli chromosome; it does not result in increased resistance to these drugs. A separate gene for erythromycin resistance (eryA) is located in the cluster of ribosomal structural genes near spc, close to minute 63. Dependence on macrolides was most clearly evident in strains carrying mutations at both eryA and mac.


Temperature-sensitive growth inhibition by valine in Salmonella typhimurium: alteration of one form of acetohydroxy acid synthetase. A strain of Salmonella typhimurium, MF1680, was isolated that required isoleucine for normal growth at 37 C but not at 27 C. In minimal medium the growth of MF1680 was strongly blocked by valine. Growth inhibition was reversed by isoleucine. When this mutant was grown at 37 C, the form of acetohydroxy acid synthetase not inhibited by valine, (AHAS(R)), could not be detected. The site of this mutation in AHAS(R), termed ilvG, was found to map in the ilv gene cluster between ilvD and ilvE.


Characterization of the membranes of Thermoplasma acidophilum. Thermoplasma acidophilum grows optimally under aeration at 59 C and pH 2. Both intact cells and membranes disaggregate below pH 1 and above pH 5, producing no sedimentable particles. Increase in ionic strength at pH 5 or below results in cellular lysis and membrane disaggregation. Membranous components produced by lysis at alkaline pH reaggregate upon reduction of both pH and ionic strength. Osmotic environment plays little role in cellular stability. Membranes prepared by sonic lysis at pH 5 exhibit vesicular structures and are composed of multiple proteins. Although the amino acid composition of the membrane proteins is similar to other mycoplasmal membranes, the number of free amino and carboxyl groups is less than half of those in Acholeplasma. Reduction of the number of free carboxyl groups results in membrane stabilization over a wide range of pH. Increase in the number of free amino groups reverses the stability of membranes relative to pH. Acidophily in Thermoplasma can be related to a significant reduction in repulsing negative charges on the membrane proteins.


Location of the structural gene for fructose-1,6-diphosphate aldolase in Escherichia coli. Gene fda has been mapped, by co-transduction, between thyA and serA on the Escherichia coli chromosome.


Studies with a gluconate-6-phosphate dehydrogenase mutant in Escherichia coli strain C. A map location of the gluconate-6-phosphate dehydrogenase (gnd) marker was estimated in Escherichia coli C at approximately 46 min by P1 transduction. The gnd locus appears to lie between the co-transducible histidine and prophage P2 location I markers.


Association of lysozyme with ribosomes and ribosome precursor particles. Lysozyme, used to prepare osmotically fragile cells, combines with ribosomal subunits unless salt is present in excess of 50 mM. The binding of lysozyme to precursor ribonucleoprotein particles can result in their conversion to particles which sediment as mature ribosomes.


Deletion map of the chloramphenicol resistance region of R1 and R100-1. Recombination between single-site and multisite chloramphenicol-sensitive mutants of the F-like R factors R1 and R100-1 indicates that the chloramphenicol resistance region is a single structural gene coding for the 20,000-molecular weight subunit of chloramphenicol acetyltransferase.


General method for the isolation of plasmid deoxyribonucleic acid. Plasmid deoxyribonucleic acid (DNA) ranging from 5 x 10(6) to 65 x 10(6) daltons may be isolated from chromosomal DNA by the preferential precipitation of the higher-molecular-weight chromosomal DNA in the presence of sodium lauryl sulfate and a high concentration of NaCl.


Influence of thymine starvation on the integrity of episomal and chromosomal deoxyribonucleic acids in Escherichia coli CR34 (lambda ind-). The effect of thymine deprivation on the integrity of phage lambda, sex factor, and chromosomal deoxyribonucleic acid (DNA) in Escherichia coli CR34 (lambda ind(-)) was examined by sedimenting cell lysates through alkaline sucrose gradients. Both sex factor and chromosomal DNAs showed evidence of being degraded during the starvation period. In contrast, no loss of closed circular lambda DNA was observed.


Distribution of an inducible hexose-phosphate transport system among various bacteria. A transport system for glucose-6-phosphate, which is inducible by glucose-6-phosphate but not glucose or beta-glycerophosphate, occurs in a variety of bacterial genera. The correlation of the fosfomycin sensitivity with the presence of the transport system is described.


Isolation and characterization of phi80 transducing bacteriophage for a ribonucleic acid polymerase gene. A new method for isolating specialized transducing phages is described. It was used to isolate a group of phi80 transducing phages which carry various bacterial markers from the metB region of the Escherichia coli chromosome. Some of the phages selected for transduction of the supA36 marker were also shown to carry rif, a locus known to specify the beta subunit of ribonucleic acid polymerase. Expression of the prophage rif(r) gene in lysogens was demonstrated by its ability to confer rifampin resistance on part of the cellular ribonucleic acid polymerase pool.


Isolation of a specialized lambda transducing bacteriophage carrying the beta subunit gene for Escherichia coli ribonucleic acid polymerase. A heat-inducible lysis-defective lambda prophage has been integrated directly into the E. coli chromosome at a site (bfe) very closely linked to the ribonucleic acid polymerase mutation rif(d), a dominant rifampin resistance allele. This unusual lysogen has facilitated the isolation of specialized transducing phages conferring rifampin resistance to sensitive cells, and carrying at least the beta subunit gene of RNA polymerase in intact form.


Nitrosoguanidine assay of episomal integration in Escherichia coli. Mutations affecting utilization of lactose and resistance to the male-specific phages f1, f2, and Qbeta tend to occur simultaneously more often than expected by chance in Hfr strains whose origin of transfer is close to the genes for lactose utilization, but not in F(+) strains. Strains derived from the Hfr, but exhibiting poor ability to transfer early chromosomal genes, may or may not show this comutation phenomenon. These results support the concept that the F factor is integrated into the Hfr chromosome during vegetative growth, but is autonomous in the F(+) strains and could serve as an assay for episomal localization.


Isolation of temperature-sensitive membrane mutants of Escherichia coli K-12. Mutants with impaired biosynthesis of unsaturated fatty acids or altered metabolism of the phospholipids were isolated at a rather high frequency from a set of temperature-sensitive lysis mutants. It is suggested that preselection for the lysis phenotype makes it possible to isolate several kinds of mutants affected in the integrity of the cytoplasmic membrane.


Participation of branched-chain amino acid analogues in multivalent repression. Two isoleucine analogues and two leucine analogues were examined for their ability to replace the natural amino acid preventing the accumulation of threonine deaminase-forming potential. The procedure used to study repression by the analogues distinguishes between true repression and the formation of inactive enzyme by the analogue in question. The leucine analogue 4-azaleucine was found to replace leucine in multivalent repression of threonine deaminase-forming potential in Escherichia coli but not in Salmonella typhimurium. Another leucine analogue, trifluoroleucine, was only partially effective in causing repression in either organism. The isoleucine analogue 4-azaisoleucine was ineffective in replacing isoleucine in repression. In contrast, 4-thiaisoleucine effectively replaced isoleucine in the repression of threonine deaminase-forming potential in S. typhimurium and E. coli.


Genetic characterization of mutations which affect catabolite-sensitive operons in Escherichia coli, including deletions of the gene for adenyl cyclase. Sixty-two spontaneous mutations have been characterized which reduce the level of expression of catabolite-sensitive operons. These mutations appear to affect either the crp (catabolite gene activator protein) or cya (adenyl cyclase) loci. No new loci have been discovered. Deletions of the cya gene do not remove an essential function. phi80 transducing phage for the cya gene have been used to do recombination and complementation studies on cya mutants.


Influence of polyamine limitation on the chain growth rates of beta-galactosidase and of its messenger ribonucleic acid. The rates of elongation of beta-galactosidase and its messenger ribonucleic acid (RNA) were estimated in a polyamine-deficient mutant of Escherichia coli through an analysis of the kinetics of enzyme induction. The chain growth of beta-galactosidase was calculated from the time required after the appearance of an amino terminal fragment of 60 amino acids (auto-alpha) until completed enzyme began to accumulate. The elongation rate of beta-galactosidase messenger RNA was estimated from the time after induction at which streptolydigen-resistant, enzyme-forming capacity first appeared. Upon polyamine starvation, the rate of polypeptide elongation slowed from 17 to 10 amino acids per s and the messenger RNA elongation rate decreased from 47 to 30 nucleotides per s. These reductions in polymerization rates were proportional to the decrease in cellular growth rate produced by polyamine starvation. It was concluded that, although it is quite unlikely that polyamine levels are involved in regulation of cell growth, they may be acting as cofactors in the synthesis of RNA or protein, or both.


Mutant of Escherichia coli K-12 defective in the transport of basic amino acids. Escherichia coli K-12 possesses two active transport systems for arginine, two for ornithine, and two for lysine. In each case there is a low- and a high-affinity transport system. They have been characterized kinetically and by response to competitive inhibition by arginine, lysine, ornithine and other structurally related amino acids. Competitors inhibit the high-affinity systems of the three amino acids, whereas the low-affinity systems are not inhibited. On the basis of kinetic evidence and competition studies, it is concluded that there is a common high-affinity transport system for arginine, ornithine, and lysine, and three low-affinity specific ones. Repression studies have shown that arginine and ornithine repress each other's specific transport systems in addition to the repression of their own specific systems, whereas lysine represses its own specific transport system. The common transport system was found to be repressible only by lysine. A mutant was studied in which the uptake of arginine, ornithine, and lysine is reduced. The mutation was found to affect both the common and the specific transport systems.


Stable ribonucleic acid synthesis in stringent (rel+) and relaxed (rel-) polyamine auxotrophs of Escherichia coli K-12. The relationship of polyamines to stable ribonucleic acid (RNA) synthesis under conditions of amino acid withdrawal or chloramphenicol treatment was examined with the use of a closely related rel(+), rel(-) pair conditionally incapable of synthesizing putrescine. Under conditions of polyamine starvation, the cellular sperimidine level fell to one-third to one-half of the value observed in putrescine-supplemented cultures and putrescine became undetectable; cadaverine was synthesized by both strains, but the relaxed strain, MA 252, accumulated less cadaverine per cell than its stringent twin, MA 254. Upon amino acid withdrawal, the stringent strain remained stringent whether starved of or supplemented with polyamines. Similarly, the relaxed strain was capable of making RNA either with or without polyamine starvation. On the addition of chloramphenicol or upon amino acid withdrawal in the relaxed strain, supplementation with spermidine had no effect on the initial rate of RNA synthesis, although RNA accumulation was greater in the presence of added spermidine. Spermidine added at the conclusion of RNA synthesis prompted additional synthesis, although preincubation with spermidine again had no effect on the initial rate. All forms of stable RNA species were made with polyamine supplementation. The present data appear to rule out the possibility that polyamines are primary causative agents in stimulating RNA synthesis, but rather suggest an indirect or secondary role for spermidine in which the polyamines "stimulate" stable RNA synthesis probably by relieving RNA product inhibition of RNA synthesis.


Basic amino acid transport in Escherichia coli: properties of canavanine-resistant mutants. A mutant of Escherichia coli strain CanR 22 has been isolated which is resistant to growth inhibition by canavanine, an analogue of arginine. The properties of this strain and of another canavanine-resistant mutant, JC182-5 (isolated by Celis et al. [5]), were studied. The mutation is pleiotropic in that it results in a reduction in the activity of two distinct permeases, the arginine-specific and lysine-arginine-ornithine transport systems. The lesion maps at min 56 of the E. coli linkage map, at or near the argP locus. Although strain CanR 22 excretes arginine, this excretion appears to result from reduced ability to concentrate arginine, rather than the loss of transport ability being the result of excretion. This conclusion is based on findings with a canavanine-resistant strain auxotrophic for arginine, which exhibits transport properties similar to those of the prototrophic strains. Additionally, growth in the presence of arginine or ornithine results in a repression of the activity of the two basic amino acid transport systems. Neither the arginine-specific nor the lysine-arginine-ornithine binding proteins of the mutant cells show significant alterations in terms of amount, physical properties, or kinetic parameters. These observations lead to the proposal of a model for the two basic amino acid transport systems in which two carrier proteins with different specificities interact with a common energy coupling mechanism. A lesion in the gene (or one of the genes) for this coupling mechanism can confer canavanine resistance.


Deletion mapping and orientation of the histidine operon of Escherichia coli on a transducing bacteriophage. The defective prophage phi80ilambdac(I)857dhis has been mapped through both marker rescue and deletion analysis. Deletions have been isolated which put residual his genes close to trp genes. Analysis of these deletions shows that the histidine operon on the prophage is oriented clockwise as on the bacterial chromosome, thus opposite to the orientation of the trp operon. The presence of the his promoter-operator region is inferred by the ability of the prophage-carrying strain to derepress sequentially under conditions in which the histidine concentration is limiting. In addition to his, the gnd gene is also present on the prophage and is located between his and trp operons. The bacterial genes are inserted in the right arm of the prophage and substitute for all of the late function genes, except for the first three. These data indicate that the "sense" strand for transcription of the his operon in vivo must be the "R" strand.


Molecular and genetic studies of an R factor system consisting of independent transfer and drug resistance plasmids. Certain genetic, structural, and biochemical properties of a class 2 R-factor system consisting of the conjugally proficient transfer plasmid I and the naturally occurring non-conjugative tetracycline (Tc) resistance plasmid 219 are reported. I and 219 exist as separate plasmid deoxyribonucleic acid (DNA) species in both Escherichia coli and Salmonella panama, having molecular weights of 42 x 10(6) and 5.8 x 10(6), respectively. The buoyant densities of I and 219 are 1.702 and 1.710 g/cm(3), respectively, in neutral cesium chloride. Although the Tc resistance plasmid is not transmissible in a normal conjugal mating, it is mobilized in a three-component mating by plasmid I and by certain other conjugative plasmids of the fi(+) or fi(-) phenotype. Mobilization does not appear to involve intermolecular recombination between plasmids, and no covalent linkage of resistance markers and fertility functions is observed. Transformation of CaCl(2)-treated E. coli by plasmid DNA is shown to be a useful procedure for studying the biological properties of different plasmid molecular species that have been fractionated in vitro, and for selectively inserting non-self-transmissible plasmids into specific bacterial strains. The effects of tetracycline on the rate of protein synthesis carried out by plasmid 219 were studied by using isolated E. coli minicells into which this plasmid had segregated. Consistent with the results of earlier investigations showing the inducibility of plasmid-mediated Tc resistance in E. coli, the antibiotic was observed to stimulate protein synthesis in minicells carrying the plasmid 219 and totally inhibit (3)H-leucine incorporation by minicells lacking the Tc resistance marker. Five discrete polypeptide species were synthesized by minicells carrying plasmid 219; exposure of minicells or parent bacteria to Tc resulted in specific and reproducible changes in polypeptide synthesis patterns.


Messenger ribonucleic acid synthesis and degradation in Escherichia coli during inhibition of translation. Various aspects of the coupling between the movement of ribosomes along messenger ribonucleic acids (mRNA) and the synthesis and degradation of mRNA have been investigated. Decreasing the rate of movement of ribosomes along an mRNA does not affect the rate of movement of some, and possibly most, of the RNA polymerases transcribing the gene coding for that mRNA. Inhibiting translation with antibiotics such as chloramphenicol, tetracycline, or fusidic acid protects extant mRNA from degradation, presumably by immobilizing ribosomes, whereas puromycin exposes mRNA to more rapid degradation than normal. The promoter distal (3') portion of mRNA, synthesized after ribosomes have been immobilized by chloramphenicol on the promoter proximal (5') portion of the mRNA, is subsequently degraded.


Comparison of the activities of extracts of Escherichia coli and Salmonella typhimurium in amino acid incorporation. We have compared the amino acid incorporating activities of extracts of Escherichia coli and Salmonella typhimurium in in vitro protein-synthesizing systems directed by bacterial messenger ribonucleic acid (mRNA) of both species and by the genomes of coliphages Qbeta and f2. E. coli and S. typhimurium extracts translate both homologous and heterologous bacterial mRNAs at comparable rates. S. typhimurium extracts translate phage RNAs only 10 to 15% as fast as E. coli extracts do. The presence of glucose in the growth medium increases the activity of S. typhimurium extracts three- to fourfold in the phage RNA-directed systems. Glucose has a much more limited effect on the activities of E. coli extracts. We show that similar amounts of phage RNA-ribosome complexes are formed in both the E. coli and the S. typhimurium systems, indicating that the different activities observed may be attributed to different rates of peptide elongation or to the formation of complexes at different sites on the RNA strand.


Regulation of cell division in a temperature-sensitive division mutant of Escherichia coli. Escherichia coli fil ts forms multinucleate filaments when suspensions of about 10(7) organisms per ml are shifted from 37 to 43 C in rich medium. Occasional septation continues, chiefly at the poles, and immediately becomes more frequent when the filaments are returned to 37 C. The addition of chloramphenicol (200 mug/ml) at either temperature initially stimulates the formation of polar septa. When very dilute suspensions of the strain (<10(6) organisms per ml) are shifted to the restrictive temperature, the inhibition of septation is more complete and only seldom reversible. Conversely, cell division is little affected when suspensions of >10(8) organisms per ml, or microcolonies of several hundred organisms on agar, are incubated at 43 C; evidence is presented that this is a consequence of a slight reduction in the mutant's growth rate. In certain media, septation is blocked irreversibly by even brief exposure to 43 C, after which cell elongation without division proceeds at 37 C for some hours. Several findings, when considered together, suggest that the cytoplasmic membrane is normal at the restrictive temperature, and that the block in septation is caused by a defect in the cell wall: it is largely overcome by NaCl, but not by sucrose; in some circumstances the filaments become swollen and develop localized bulges in the wall, yet the membrane remains intact and retains its selective permeability; lastly, the strain is insensitive to deoxycholate at both temperatures. The mutation has been mapped between arg B and thr, at a locus which appears to be distinct from others known primarily to influence cell division.


Induction and repression in the S-adenosylmethionine and methionine biosynthetic systems of Saccharomyces cerevisiae. Two methionine biosynthetic enzymes and the methionine adenosyltransferase are repressed in Saccharomyces cerevisiae when grown under conditions where the intracellular levels of S-adenosylmethionine are high. The nature of the co-repressor molecule of this repression was investigated by following the intracellular levels of methionine, S-adenosylmethionine, and S-adenosylhomocysteine, as well as enzyme activities, after growth under various conditions. Under all of the conditions found to repress these enzymes, there is an accompanying induction of the S-adenosylmethionine-homocysteine methyltransferase which suggests that this enzyme may play a key role in the regulation of S-adenosylmethionine and methionine balance and synthesis. S-methylmethionine also induces the methyltransferase, but unlike S-adenosylmethionine, it does not repress the methionine adenosyltransferase or other methionine biosynthetic enzymes tested.


Modification of ribosomes in cryptopleurine-resistant mutants of yeast. Cryptopleurine-resistant mutants of Saccharomyces cerevisiae were isolated. A single, recessive nuclear gene, very closely linked to the mating locus (2.1 centimorgans), is responsible for resistance. Ribosomes from the mutants were found to be resistant to cryptopleurine when analyzed by poly(U)-directed polyphenylalanine synthesis. Analysis of the distribution of ribosomes between monosomes and polysomes in sensitive cells exposed to cryptopleurine suggests that some step is inhibited during the elongation phase of protein synthesis.


Glucosylation of lipopolysaccharide in Salmonella: mutants negative for O antigen factor 1221. In salmonella O group B, the O antigen factor 12(2) is created by glucosylation at C4 of the galactose units of the O side chains; phage-determined glucosylation at C6 of these galactose units yields factor 1. 12(2)-negative mutants were isolated from 12(2) (+) (stable) parents (genetically oafR(+st)). All 20 mutants studied were stable in respect of their 12(2) character. In eight of them, lysogenization by phage P22 resulted in the appearance of the 12(2) factor-these were interpreted to be defective in the enzyme(s) needed to synthesize the glucose-lipid intermediate that participates in both 12(2)- and 1-specific glucosylation; the corresponding cistron was termed oafE. This "complementation" assay also demonstrated that the P22 genome can determine the synthesis of this glucose-lipid intermediate. The 12(2) character in the oafE(-) mutants became variable after P22 lysogenization, corresponding to factor 1 variation normally determined by this phage. In the remaining 12 mutants, P22 caused the appearance of a variable factor 1, but not of 12(2). The lesion in all the 12(2) mutants was mapped close to the gene purE at min 19 of the Salmonella map. This is the same area where the locus oafR that controls the variation (stable or variable, + or -) of 12(2) had been previously mapped. The results suggest the presence of a 12(2) glucosylation operon in this region.


Characterization of Escherichia coli mutants tolerant to bacteriocin JF246: two new classes of tolerant mutants. Several hundred independent bacteriocin-tolerant mutants have been isolated without mutagenesis from three strains of Escherichia coli. On the basis of patterns of sensitivity to eight different colicins, over 85% of these mutants could be grouped into four classes. Two classes of mutants, class A and class B, are equivalent to tolA and tolB type mutants. We found tolA and tolB mutants were sensitive to the antibiotic bacitracin. The other two classes of bacteriocin-tolerant mutants, class F and class G, are distinguished from other types of colicin-tolerant mutants on the basis of sensitivity to colicins, dyes, detergents, antibiotics, and chelating agents. The mutation in class F and class G mutants is located between 21 to 23 min on the E. coli chromosome. We propose to designate the loci of these mutations as tolF and tolG, respectively.


Outer penetration barrier of Escherichia coli K-12: kinetics of the uptake of gentian violet by wild type and envelope mutants. Wild-type strains of Escherichia coli K-12 adsorb gentian violet to the cell surface, but the dye is not transported into the cytoplasm. However, when some mutants that have an altered outer membrane are exposed to gentian violet, the dye is also found in the ribosomal fraction. The transport into the cytoplasm is inhibited at 0 C and requires that the concentration of gentian violet exceeds a threshold value. The initial rate of uptake as well as the amount of gentian violet found in the cytoplasm increases with the concentration of the dye in the medium. The rate of transport of the dye into the cytoplasm is much lower for stationary mutant cells than for exponentially growing cells. The rate of uptake into the cytoplasm increases with increasing deficiency of carbohydrate in the lipopolysaccharide (carbohydrate content lpsB > lpsA > galU). However, other components are also responsible for the barrier since an envA mutant which is not altered in the lipopolysaccharide carbohydrates show an extremely rapid uptake of the dye. The rate of uptake for the envA mutant was the highest found and the same as that of spheroplasts. Growth in the presence of agents affecting the murein sacculus, e.g., lysozyme and sublethal concentrations of penicillin, increased the rate of uptake of gentian violet. Brief treatments with tris(hydroxymethyl)aminomethane-ethylenediaminetetraacetic acid drastically impaired the barrier function. Inhibition of protein synthesis by chloramphenicol also opened the barrier to gentian violet. In conclusion, the outer part of the bacterial envelope is a penetration barrier for gentian violet and probably also for other substances. The lipopolysaccharide, the murein and also other components are important for the function of this barrier. Resistance to gentian violet was found to be inversely correlated to the rate of penetration of the dye into the cytoplasm.


Sporulation synchrony of Saccharomyces cerevisiae grown in various carbon sources. Sporulation of several strains of Saccharomyces cerevisiae grown in a variety of carbon sources that do not repress the tricarboxylic acid cycle enzymes was more synchronous than the sporulation of cells grown in medium containing dextrose which does repress those enzymes. Dextrose-grown cells showed optimal sporulation synchrony when inoculated into sporulation medium from early stationary phase when the dextrose in the medium is exhausted. Logarithmic-phase cells grown in either non-fermentable carbon sources (acetate and glycerol) or a fermentable carbon source that does not repress tricarboxylic acid cycle enzymes (galactose) sporulated more synchronously than the early stationary-phase dextrose cells. Attempts were made to sporulate cells taken from both complex and semidefined media. The semidefined acetate medium failed to support the growth of a number of strains. However, cells grown in the complex acetate medium, as well as both complex and semidefined glycerol and galactose media, sporulated with better synchrony than did the dextrose-grown cells.


Suppression of lex mutations affecting deoxyribonucleic acid repair in Escherichia coli K-12 by closely linked thermosensitive mutations. A major class of ultraviolet (UV)-resistant derivatives of lex(-) strains of Escherichia coli K-12 grows normally at 30 C but at 42.5 C fails to produce colonies on complete or minimal agar. At 42.5 C these thermosensitive strains form filaments without septa, due to an apparent defect in cell division. Deoxyribonucleic acid degradation in UV-irradiated cultures of the thermosensitive strains is slow, in contrast to the rapid degradation in UV-irradiated cultures of the parental lex(-) strains. The thermosensitive mutations (tsl) are tightly linked (less than 0.04 min on the E. coli K-12 linkage map) to the site of the lex mutation in the parental strain and could lie within the same gene. The tsl(+)/tsl(-) heterozygotes grow at 42.5 C and are UV resistant when grown at 30 or 42.5 C. The tsl mutations are, therefore, recessive in contrast to lex mutations, which are dominant. It appears likely that the tsl mutations alter the diffusible product that gives rise to the Lex(-) mutant phenotype. This product appears to be necessary for deoxyribonucleic acid repair and cell division.


Poly-beta-hydroxybutyrate metabolism during growth and sporulation of Clostridium botulinum. The granules observed in the cytoplasm of cells of sporogenic and asporogenic strains of Clostridium botulinum type E were isolated at various developmental stages of growth and sporulation. Electron microscopy of thin sections showed that most of the granules were dispersed throughout the cytoplasm. Chemical analysis and electron microscopy showed that the granules were poly-beta-hydroxybutyrate (PHB). The polymer began to accumulate after 8 h of growth, reaching 9 and 13% of the cell dry weight in the sporogenic and asporogenic strains, respectively, during early stationary phase. (14)C-acetate was readily incorporated into PHB. The rate of assimilation paralleled the production and utilization of PHB, indicating that the acetate served as its precursor. (14)C-butyric acid was not utilized to any significant extent. Most of the PHB which had accumulated in the sporogenic strain was catabolized during the development of the spore, but in the asporogenic mutant it remained essentially unchanged. The findings suggest that the PHB provides endogenous carbon and energy for the synthesis of spore-specific components required for spore maturation.


Studies on T3-induced ribonucleic acid polymerase. IV. Transcription of denatured deoxyribonucleic acid preparations by T3 ribonucleic acid polymerase.


Specific chemical cleavage in high yield at the amino peptide bonds of cysteine and cystine residues.


The specificity of cathepsin D.

The specificity of cathepsin D.


Pseudoverification. Hydrolysis of aminoacyl transfer ribonucleic acid catalyzed by an aminoacyl transfer ribonucleic acid synthetase in mixed solvents.


Pseudoverification of mixed aminoacyl transfer ribonucleic acids. The generality of the process.


Purification and properties of a ribonucleic acid primer-independent polyriboadenylate polymerase from Escherichia coli.


Siroheme and sirohydrochlorin. The basis for a new type of porphyrin-related prosthetic group common to both assimilatory and dissimilatory sulfite reductases.


Immobilization of beta-galactosidase on an insoluble carrier with a polyisocyanate polymer. I. Preparation and properties.


Immobilization of beta-galactosidase on an insoluble carrier with a polyisocyanate polymer. II. Kinetics and stability.


Reduction of lactose content of milk by entrapped beta-galactosidase. I. Characteristics of beta-galactosidase from yeast and Escherichia coli.


Effects of various additives on in vitro survival time of human fibroblasts.


Antiparasitic 5-nitrothiazoles and 5-nitro-4-thiazolines. 2.


Antiparasitic 5-nitrothiazoles and 5-nitro-4-thiazolines. 3.


Antimalarials. 5. 2-Aryl-6-trifluoromethyl-4-pyridinemethanols.


Thiosulfuric acid analog of quinine as a potential antimalarial agent.


Synthesis and microbiological properties of 3-amino-1-hydroxy-2-indolinone and related compounds.


An improved solid-phase synthesis of the luteinizing-hormone releasing-hormone-follicle-stimulating hormone releasing-hormone (LH-RH-FSH-RH).


N-Substituted derivatives of erythromycylamine.


Quantitation of reticuloendothelial cells in rat marrow.


Letter: Immunofluorescence as a diagnostic aid in cryptococcal meningitis.


Albert Lasker Clinical Medical Research Awards: Citations.


Development of electric control of cardiac rhythm.


"The pleasurable recreation" of Dr. William H. Feldman.


A plea for balance. Presidential address.


Proliferation and differentiation of gastrointestinal cells.


Replantation surgery surgery in China. Report of the American Replantation Mission to China.


Findings in 300 patients with facial lacerations.


Clinical replantation of digits.

Clinical replantation of digits.


Soft tissue changes in the hands of drug addicts.


Use of the gastroepiploic vessels as recipient or donor vessels in the free transfer of composite flaps by microvascular anastomoses.


Replantation of a completely amputated distal thumb without venous anastomosis. Case report.


Use of acrylic fiber in a pressure dressing.


Immunologic glomerular injury.

Immunologic glomerular injury.


Immunologic disorders of the gastrointestinal tract.


Letter: Differentiating RMCD test from RAST.


The immune cytopenias.

The immune cytopenias.


Assessment of body-image disturbances in peripheral neurological disease.


In memoriam: Basil W. H. Fergus.

In memoriam: Basil W. H. Fergus.


Nasolabial subcutaneous pedicle flap.

Nasolabial subcutaneous pedicle flap.


Dermatitis factitia.

Dermatitis factitia.


Hydroxyurea-sensitive mutants of T4. II. Degradation and utilization of bacterial DNA.


Lambda-repressed mutants of bacteriophage T5. I. Isolation and genetical characterization.


Genetic characterization of a prm- mutant of bacteriophage lambda.


A new effect of the rex gene of phage lambda: premature lysis after infection by phage T1.


An f1 mutant with reduced sensitivity to P1 restriction.


Membrane binding of phage S13 messenger RNA.


Lambda imm lambda-434: a phage with a hybrid immunity region.


St. Louis encephalitis virus: an ultrastructural study of infection in a mosquito vector.


In memoriam. Tom Moore 1928-1973.

In memoriam. Tom Moore 1928-1973.


Oral habits--studies in form, function, and therapy.


Allergy: expanding horizons in science and patient care. A 30-minute color-sound 16-mm motion picture.


Re-appraisal of helium-oxygen therapy on patients with chronic lung disease.


Fractionation of mouse myeloma chromatin.


Characterization of poly(riboadenylic acid) segments in L-cell messenger ribonucleic acid.


Studies on the fluorescence of the Y base of yeast phenylalanine transfer ribonucleic acid. Effect of pH, aminoacylation, and interaction with elongation factor Tu.


Kinetics of homologous and heterologous aminoacylation with yeast phenylalanyl transfer ribonucleic acid synthetase.


Regulatory features of the cysteine desulfhydrase of Salmonella typhimurium.


Monitoring in anesthesia. Legal aspects.


Blood volume studies.

Blood volume studies.


Pulmonary function testing.

Pulmonary function testing.


Monitoring in anesthesia. Patients with multisystem trauma.


Monitoring in anesthesia. Neurosurgery.

Monitoring in anesthesia. Neurosurgery.


Monitoring in anesthesia. Pediatrics.

Monitoring in anesthesia. Pediatrics.


Patients in renal failure and those undergoing repeated dialysis.


Monitoring in anesthesia. The recovery room.


Safety in the use of monitoring equipment.


The stethoscope--the anesthesiologist's best friend.


The coronary care unit.

The coronary care unit.


Telemetry in monitoring practice.

Telemetry in monitoring practice.


Computers in monitoring practice.

Computers in monitoring practice.


The cell surface in cell interactions.

The cell surface in cell interactions.


On the screening, diagnosis and investigation of hereditary aminoacidopathies.


The citation of bibliographic references in biochemical journals. Recommendations 1971.


Postjunctional supersensitivity and subsensitivity of excitable tissues to drugs.


Kinetic properties of phenylalanyl-tRNA and seryl-tRNA synthetases for normal substrates and fluorescent analogs.


Yeast 3-phosphoglycerate kinase. Interaction of enzyme with substrates studied by partial isotopic exchange and difference spectrophotometry.


Autoimmune uveo-retinitis in the rat sensitized with retina photoreceptor cell antigen.


A modified agarose method for detection of migration inhibitory factor and delineation of its antigen dependency.


Studies on heterophile antigen in lymphoma and leukemia spleens by means of absorption of infectious mononucleosis sera.


Ultraviolet irradiation inhibition of replicative deoxyribonucleic acid synthesis in toluene-treated Escherichia coli.


The biosynthesis of basement membrane collagen in embryonic chick lens. 3. Intracellular formation of the triple helix and the formation of aggregates through disulfide bonds.


Role of elongation factor G and a protein factor on the release of ribosomes from messenger ribonucleic acid.


A complex between the catalytic and regulatory subunits of aspartate transcarbamylase.


Crystallographic studies on L-asparaginase from Proteus vulgaris. I. Preliminary crystal data.


A systematic approach to antibiotic control of dental caries.


Immediate mandibular reconstruction following resection.


Pretraining effects on performance of rats with hippocampal lesions.


Self-stimulation of preoptic and lateral hypothalamus during behavioral thermo-regulation in the albino rat.


2-Substituted cinchoninic acids as intermediates in quinolinemethanol syntheses.


Structure-activity relationship of chloramphenicols.


Preparation and antimalarial activity of some derivatives of 6-bromo-alpha-(di-n-heptylaminomethyl)-9-phenanthrenemethanol.


Synthesis of 3-(aminoalkyl)-1-((5-nitrofurfurylidene)amino)hydantoins.


Subunits of RNA polymerase in function and structure. 3. Accumulation of the intermediate alpha 2beta in the subunit assembly of Escherichia coli RNA polymerase by treatment with cyanate.


Subunits of RNA polymerase in function and structure. IV. Enhancing role of sigma in the subunit assembly of Escherichia coli RNA polymerase.


X-ray diffraction studies of bacterial pili.


Control of bacteriophage T4 DNA polymerase synthesis.


Augmentation of the adoptive transfer of specific tumor immunity by non-specifically immunized macrophages.


Suggested correlation between radiation-induced immunosuppression and radiogenic leukemia in mice.


Antitumor action of cis-dichlorobis(methylamine)platinum(II).


Tumorigenesis by Millipore filters in mice: histology and ultrastructure of tissue reactions as related to pore size.


Brief communication: Effects of chronic cyclophosphamide and methotrexate treatment on skin allograft survival in mice and rats.


A clinical and histological evaluation of autogenous iliac bone grafts in humans. I. Wound healing 2 to 8 months.


A clinical and histological evaluation of autogenous iliac bone grafts in humans. II. External root resorption.


A dual-parameter flow microfluorometer for rapid cell analysis.


Mesenchymoma of the mandible.

Mesenchymoma of the mandible.


The effect of a yeast extract (PCO) on the mitotic activity of neoplastic and normal cells in vitro.


Wastewater treatment: detergents.

Wastewater treatment: detergents.


Marine and estuarine pollution.

Marine and estuarine pollution.


Microbiology--detection of bacterial pathogens and their occurrence.


Effects of residual chlorine on aquatic life.


Pankhurst tubes modified to indicate anaerobiosis.


Affinity chromatography.

Affinity chromatography.


State-approved schools of nursing-R.N. 1973.


Masters education. Route to opportunities in modern nursing.


Certification of occupational health nurses.


The effects of anxiety and frustration on muscular tension related to the temporomandibular joint syndrome.


Anson Jones: Texas patriot.

Anson Jones: Texas patriot.


Anastomosis of the small intestine of pigs by Schmieden's suture.


Metabolic care of the horse with acute intestinal obstruction.


Plasma levels of nortriptyline in the treatment of endogenous depression.


Managing medical emergencies caused by bacterial infections.


Improved techniques of identification and determination of airborne asbestos.


Epizootiologic aspects of raccoon rabies in Florida.


Creutzfeldt-Jakob disease: a case-control study.


Immunization of man against sporozite-induced falciparum malaria.


In search of the opiate receptor.

In search of the opiate receptor.


A new computer-assisted method for rapid analysis of cardiac catheterization data.


Cerebral mucormycosis and renal aspergillosis in heroin addicts without endocarditis.


Disparity between humoral and cellular immune responses to desoxyribonucleic acid in systemic lupus erythematosus.


Multidisciplinary responsibilities in orthopedic-occlusal rehabilitation.


Enamel pretreatment: a critical variable in direct bonding systems.


Martin Dewey Memorial Award for 1973. Presentation of the Martin Dewey Memorial Award to J. Victor Benton by George R. Webber.


The concept of child advocacy.

The concept of child advocacy.


In memoriam. Ludwig von Bertalanffy 1901-1972.


Editorial: "There shall be no pain".

Editorial: "There shall be no pain".


Some pupils of John Hunter. II.

Some pupils of John Hunter. II.


The pancreas as a transplantable organ.

The pancreas as a transplantable organ.


A continuous suture technique for mitral valve replacement.


Quantitative conjunctival bacteriology.

Quantitative conjunctival bacteriology.


Diverticular disease of the large intestine.


Cornea and sclera.

Cornea and sclera.


Hematopoiesis versus osteogenesis in ectopic bone marrow transplants.


Granulocyte-monocyte colony-forming capacity of human marrow: a clinical study.


Tissue factor activity of normal and leukemic cells.


Defective capacity of bone marrow from nude mice to restore lethally irradiated recipients.


Paul Revere (1734-1818). Dentist and patriot.


Psychiatry in South-East Asia.

Psychiatry in South-East Asia.


Iprindole and imipramine in non-psychotic depressed out-patients.


Letter: Osler and acupuncture.

Letter: Osler and acupuncture.


Medieval survivals in 17th century English medicine.


Transferable antibiotic resistance in E. coli and Klebsiella pneumoniae. Twenty-three of 43 E. coli and 25 of 39 Klebsiella isolates, resistant to two or more antibiotics, transferred one or more resistance genes to a recipient E. coli K(12) culture. Resistances transferred most frequently by both species were those to kanamycin and neomycin. E. coli cultures transferred resistance to tetracycline, chloramphenicol, ampicillin and carbenicillin, whereas Klebsiella isolates transferred resistance to the first two of these antibiotics. Extrapolation of these results to a larger series of isolations of E. coli and Klebsiella from hospital patients suggested that 21 and 18% respectively of cultures of these two organisms carried potentially transferable resistance.


Presidental address: Christ and psychiatry.


Psychopharmacology. Yesterday, today and tomorrow: a point of view.


Freud's "The Moses  of Michelangelo": an ethological viewpoint.


Calcium distribution in human and bovine surface enamel.


The acquisition of fluoride by tooth enamel in vivo from self-applied APF gel and prophylaxis paste.


Experimental infective manganese pneumoconiosis in guinea pigs.


The pattern of malignant lymphomas. A study of two hundred cases.


A reinvestigation of the synthesis and properties of trans-4,5-dehydrolysine.


Medicare and medicaid, 1973.

Medicare and medicaid, 1973.


Biosynthesis of prodigiosin. Incorporation patterns of C-labeled alanine, proline, glycine, and serine elucidated by fourier transform nuclear magnetic resonance.


Sound wave diagnosis for cancer developed.


Immunological prostate cancer test developed.


The Abraham Flexner Award. Dr. George T. Harrell, Jr.


The Borden Award. Dr. Thomas C. Merigan, Jr.


Infancy in a cultural context. Caudill's contribution to comparative child development.


Emission of microbial aerosols from sewage treatment plants that use trickling filters.


The active role of schools in mental health as seen in retrospect and prospect.


Studies of the metabolism of dapsone in man and experimental animals: formation of N-hydroxy metabolites.


American Lung Association: shorter name, wider aim.


Escherichia coli in urinary tract infection: an epidemiological study.


Ophthalmic old wives' tales.

Ophthalmic old wives' tales.


Pathologist's view of JFK autopsy: an unsolved case. Ninth anniversary of assassination.


Chemonucleolysis. A preliminary report.

Chemonucleolysis. A preliminary report.


Methadone induced mortality as a function of the circadian cycle.


Continued expression of H-Y antigen on male lymphoid cells resident in female (chimaeric) mice.


Ovarian control of vitellogenin synthesis by the fat body in Aedes aegypti.


Sterilization of rodent and other pests using a synthetic oestrogen.


San Miguel sea lion virus isolation, preliminary characterization and relationship to vesicular exanthema of swine virus.


Versatile interactive graphics display system for molecular modelling by computer.


Dislocations in tobacco mosaic virus.

Dislocations in tobacco mosaic virus.


Tooth chipping in the australopithecines.


Richard J. Winzler.

Richard J. Winzler.


Growth of the biochemical literature.

Growth of the biochemical literature.


Histidinaemic mutant in the mouse.

Histidinaemic mutant in the mouse.


Model for membrane movements in the neural growth cone.


Rapid immunological method for diagnosis of natural scrapie in sheep.


Embryonic and adult chymotrypsinogens of chicken pancreas.


Reflex balance.

Reflex balance.


Modification of tumour growth with a defined glycoprotein antigen.


Evolutionary relationship between carboxyterminal region of a human alpha chain and other immunoglobulin heavy chain constant regions.


Effects of antibodies to luteinizing hormone-releasing hormone in the male rabbit and on the rat oestrous cycle.


Identification by radioimmunoassay of the luteinizing hormone-releasing hormone in human urine.


Haemoglobin synthesis during human foetal development.


Significance of lead isotope composition in blood.


Aggregation of human platelets by bovine or human factor VIII: role of carbohydrate side chains.


Locating protein in membranes.

Locating protein in membranes.


Enzyme-containing liposomes alleviate a model for storage disease.


Emergence of rifampin-resistance in Chlamydia trachomatis.


Scrapie-like antigen(s) in ageing tissues.


Role of activity in the differentiation of slow and fast muscles.


Malignant tumours of liver and lung in rats fed aminopyrine or heptamethyleneimine together with nitrite.


Early and late methylations in HeLa cell ribosome maturation.


Effects of contraceptive pill constituents on foetal mouse hearts.


Chemical and mechanical requirements for fibroblast adhesion.


Methods of examining fibrinolysis in plasma.


Trypanosome identification by electrophoresis of soluble enzymes.


Photomicrography of corneal endothelial cells in vivo.


Radiation sterilization of Aedes aegypti in nitrogen and implications for sterile male technique.


New complexes of phenols and lactams.

New complexes of phenols and lactams.


Evidence of two operators in the biotin locus of Escherichia coli.


Letter: No evidence for a common evolutionary origin of 5S rRNA and tRNA.


Diagnosis of superior sagittal sinus thrombosis by dynamic and sequential brain scanning. Report of one case.


Complement independence of stimulation of mouse splenic B lymphocytes by mitogens.


Mortality of stroke among U.S. veterans in Georgia and five western states. VI. Criteria and guidelines for automated diagnosis of stroke from medical records.


Field studies of monocularly evoked cerebral potentials in bitemporal hemianopsia.


Location of the site of the tranquillizing action of diazepam by intralimbic application.


Geneticists and the biology of race crossing. Geneticists in England and the United States clearly reversed their published remarks on the effects of race crossing between 1930 and 1950. The reversal occurred in two steps. First came the change in the 1930's from a condemnation of wide race crosses to an agnostic view. The second change, from the agnostic view to the belief that wide race crosses were at worst biologically harmless, took place during and shortly after World War II. The entire reversal occurred in the light of little new compelling data from studies of actual human race crosses. The lack of new data is unsurprising. Few geneticists wished to initiate experiments that took three human generations to complete. And controlled race crosses are hard to arrange, even with government grants. What might be more surprising was the willingness of geneticists to make such positive statements about race crossing when they had so little reliable genetic evidence. I interviewed or wrote to ten prominent geneticists who worked on human genetics between 1930 and 1950. Not one believed that new evidence on race crossing was the primary reason why geneticists changed their minds about the effects of race crossing. One plausible explanation, that the rise of "population thinking" (44) caused geneticists to change their minds, does not fit the evidence. Castle was no more of a "population" thinker than East, yet they differed radically in their conclusions about race crossing. What, then, did cause geneticists to change their minds? Most important was the revulsion of educated people in the United States and England to Nazi race doctrines and their use in justifying extermination of Jews. Few geneticists wanted to argue, as had the Nazis, that biology showed race crossing was harmful. Instead, having witnessed the horrible toll, geneticists naturally wanted to argue that biology showed race crossing was at worst harmless. No racist nation could misuse that conclusion. And geneticists did revise their biology to fit their feelings of revulsion. Geneticists' ideas about the related question of hereditary mental differences between races is perhaps undergoing a similar development to that seen earlier in their ideas about race crossing. In 1951, judging from the response to the Unesco second statement on race and comments in genetics literature, most geneticists agreed with Muller that races probably differed in significant average mental traits. By 1969, when Arthur Jensen advocated this view in his controversial article (45), most geneticists who spoke publicly on the issue had adopted an agnostic position. Knowledge of hereditary racial differences in IQ had scarcely changed since 1951, but society had changed considerably in racial attitudes. It will be interesting to see if during the next several decades geneticists will argue, on the basis of little additional evidence, that hereditary mental differences between races do not exist. I am not condemning geneticists because social and political factors have influenced their scientific conclusions about race crossing and race differences. It is necessary and natural that changing social attitudes will influence areas of biology where little is known and the conclusions are possibly socially explosive. The real danger is not that biology changes with society, but that the public expects biology to provide the objective truth apart from social influences. Geneticists and the public should realize that the science of genetics is often closely intertwined with social attitudes and political considerations.


The expanding role of diagnostic ultrasound in obstetrics and gynecology.


Saxton Temple Pope, M.D.

Saxton Temple Pope, M.D.


Bilateral nephrectomy in patients with polycystic renal disease.


Normal and defective phagocytosis. Theory, clinical aspects and laboratory diagnosis.


25th anniversary of the World Health Organization.


Biochemical evaluation of low dose of urokinase in acute myocardial infarction. A double-blind study.


Renal involvement in essential cryoglobulinaemia.


Pregnancy in a patient after cadaveric renal transplantation.


Isochromosome X. Clinical and psychological findings.


Leptospirosis with acalculous cholecystitis.


Letter: Urosepsis with jaundice due to hemolytic Escherichia coli.


Pulmonary cryptococcosis: clinical forms and treatment. A Center for Disease Control cooperative mycoses study.


Effect of isoniazid on reproduction.

Effect of isoniazid on reproduction.


Further studies on the inactivation of mycobacteriophage D29 by chloroform.


Lysosomal enzyme release in canine endotoxin shock treated with methylprednisolone.


Meromelia and other developmental abnormalities in experimental oligohydramnios.


Percutaneous transvenous endomyocardial biopsy in human heart recipients. Experience with a new technique.


Applications of pressure reactions to acetylene chemistry.


Pulmonary hypertension and congenital heart disease.


Editorial: Wider application of the endomyocardial biopsy technique.


The presence of cellulose microfibrils in the proteinaceous slime track of Dictyostelium discoideum.


Technique of direct goniotomy.

Technique of direct goniotomy.


Derrick Tilton Vail, 1898-1973.

Derrick Tilton Vail, 1898-1973.


Morphological and functional aspects of oxytetracycline administration to conventional rats.


A pilot study of vitamin B12 in the treatment of tiredness.


Extracellular localization of cathepsin D in ossifying cartilage.


The effects of anorexic doses of dextro-amphetamine on the ventromedial-hypothalamic hyperphagic rat.


Renin activity in canine acute hepatic necrosis and chronic toxic hepatitis.


External otitis, acute diffuse. Evaluation of therapy.


First stereotaxic apparatus created by Russian scientists in the 19th century.


Studies on the metabolism of phenylalanine and tyrosine in patients with renal disease.


Alterations in turnover and endogenous levels of norepinephrine in cerebral cortex following electrical stimulation and acute axotomy of cerebral noradrenergic pathways.


The sites of action of bumetanide in man.


Transplanted mucosa of the mouse intestine as model for cell proliferation studies.


The metapsychology of pleasure.

The metapsychology of pleasure.


Letter: Radioisotope scan--a possible aid in differentiating retained gastric antrum from Zollinger-Ellison syndrome in patients with recurrent peptic ulcer.


The Freud library.

The Freud library.


A controlled comparison of metiapine and chlorpromazine in chronic schizophrenia.


Clinical trial with guanabenz, a new antihypertensive agent.


Long-term use of molindone in schizophrenics.


Cell-cycling characteristics of exogenous spleen colony-forming units.


An ASDC CE certificate.

An ASDC CE certificate.


Ribonucleoprotein antibodies: frequency and clinical significance in systemic lupus erythematosus, scleroderma, and mixed connective tissue disease.


The value of endoscopy and secretion studies in the management of recurrent symptoms after surgery for peptic ulceration.


Alveolar bone resorption in a child with healing rickets: report of case.


Palatal lift for velopharyngeal incompetence: report of case.


The teaching of endodontics in Scandinavia: treatment of primary and young permanent teeth.


Infective endocarditis today.

Infective endocarditis today.


Reaction of the gingiva to acidulated fluoride gel.


Gram-negative bacteremic shock.

Gram-negative bacteremic shock.


Multiple familial dental anomalies: report of case.


Hyponatremic syndromes.

Hyponatremic syndromes.


Utilization of a splint combining bracket-type orthodontic bands and cold-curing resin for stabilization of replaced avulsed teeth: report of case.


Hypokalemia and hyperkalemia.

Hypokalemia and hyperkalemia.


Hypodontia, anomalies of the extremities, and associated stenosis of lacrimal ducts: report of case.


Barbiturate poisoning--an endemic disease. Five years' experience in a municipal hospital.


Non-invasive techniques in the diagnosis and management of acute cardiac problems.


Life-threatening arrhythmias.

Life-threatening arrhythmias.


Cardiac pacemakers.

Cardiac pacemakers.


The diagnosis and management of arterial aneurysms.


Acute respiratory failure. Current concepts of pathophysiology and management.


Application of ventilators in acute respiratory failure.


Recognition and management of acute and chronic hepatic encephalopathy.


Acute manifestations of platelet dysfunction.


Genetic analysis of UV inactivation, recovery and regulatory phenomena in a strain of the yeast Saccharomyces cerevisiae.


A comparative study of the effects of UV irradiation upon diploid cultures of yeast defective at the rad 3 locus.


Coliphage phi gamma, a novel type of specialized transducer.


Intensive nuclear selection in tryptophan limited cultures of Escherichia coli B-r-l, trp.


Antisuppressors in yeast.

Antisuppressors in yeast.


An operator constitutive mutant affecting the synthesis of two enzymes involved in the catabolism of nucleosides in Escherichia coli.


Genetic control of maltase formation in yeast. II. Evidence for a gene regulating the level of maltase production.


Close linkage of prd and rel genes in Escherichia coli K-12.


A role for the product of gene suA in restoration of polarity in vitro.


Mitochondrial DNA synthesis in permeable cells.


Elongation factors for chloroplast and mitochondrial protein synthesis in Chlorella vulgaris.


Specific suppression of immune response to a given antigen by emulsified oil droplets containing a mixture of antigen and dexamethasone phosphate.


Growth kinetics in cultured epithelioid cells and phenotypic expression of blood group H.


Correlation between the outputs of pepsin and HCl by isolated, ex vivo perfused, canine stomach stimulated with humoral and cholinergic drugs.


Postreplication repair in an excision-defective mutant of Escherichia coli: ultraviolet light-induced incorporation of bromodeoxyuridine into parental DNA.


Destruction of photoreactivating enzyme by 365 nm radiation.


Fluorescence and the location of tryptophan residues in protein molecules.


Inhibition of the UV-ionizing radiation synergism in Escherichia coli B/r by liquid holding between the two irradiations.


Differential effect of bursectomy on antibody production in a large and small bursa line of New Hampshire chickens.


Selective bronchial catheterization for the study of experimental lung damage in the rabbit.


Differentiation of Escherichia, Enterobacter, and Klebsiella by thin-layer chromatography.


Allogeneic bone marrow chimerism in germfree mice. 1. Prevention of spontaneous leukemia in AKR mice.


Para-aminohippurate and tetraethylammonium transport in fragments of rat renal cortex.


Influence of castration and testosterone propionate on cardiac output, renal blood flow, and blood volume in mice. The effects of castration and testosterone propionate on cardiac output, renal blood flow, and blood volume in mice were studied.  The cardiac output and renal blood flow were determined by the adaptation of the rubidium-86 method of Sapirstein.  Cardiac output also was determined with iodine-131 albumin.  Castration decreased the cardiac output, renal rubidium-86 uptake, and renal blood flow.  Testosterone propionate was ineffective after 2 days but within 7 days had restored these values to normal.  Extension of the androgen treatment did not produce any further changes.  The blood volume of the mice was decreased approximately 10% by castration and restored to normal by testosterone propionate.  Since the changes in renal blood flow and cardiac output were not observed until after 2 days of androgen treatment, they do not represent or affect any of the earliest physiological actions of androgen.  In this respect the mouse kidney is different from the uterus, ovary, and liver, where circulatory changes occur much earlier.  It is postulated that the general mechanism of hormone action may involve expansion of the microcirculation of the target organ, as has been suggested for the uterus.  The degree of decrease in blood volume after castration is similar to that in the weight of the heart and may represent a general decrease in the circulatory system or possibly vasoconstriction.


The reversal of anticholinergic intoxication in man with the cholinesterase inhibitor VX.


Immediate ventilatory response to elastic loads and positive pressure in man.


In memoriam: Solomon Kirk-Cohen.

In memoriam: Solomon Kirk-Cohen.


Cardiac muscle mechanics in the evaluation of myocardial contractility and pump function: problems, concepts, and directions.


Leakage of serum proteins in brain tissues in experimentally induced renal hypertension.


L-asparaginase: a review.

L-asparaginase: a review.


The hexokinases: kinetic, physical, and regulatory properties.


Rhodanese.

Rhodanese.


1973 Harvey A. K. Whitney lecture: Uncle Harvey.


The Medicare-Medicaid amendments.

The Medicare-Medicaid amendments.


Effects of intrauterine inoculation of bovine viral diarrhea-mucosal disease virus on uterine tubes and uterus of nonpregnant cows.


A study of cellular immune response in HL-A identical renal transplant recipients.


Experimentally induced coliform mastitis: inoculation of udders with serum-sensitive and serum-resistant organisms.


Distribution of group E Streptococcus in head and neck regions of swine.


Bilateral ex vivo renal artery reconstruction with autotransplantation.


Detection of tonsillar and nasal colonization of group E Streptococcus in swine.


Technology of multiphasic patient screening.


Optimization of the mammalian respiratory gas transport system.


Primary processes in bacterial photosynthesis.


Toward direct brain-computer communication.


Aharon (Katzir) Katchalsky.

Aharon (Katzir) Katchalsky.


Long-range physical forces in the biological milieu.


Structure and symmetry of oligomeric enzymes.


Electric and magnetic field of the heart.


Interpretation of some microelectrode measurements of electrical properties of cells.


Frequency dynamics of peripheral vascular blood flow.


Clustering.

Clustering.


Virological and immunofluorescent studies on the multiplication of Sindbis virus in L cells.


Dependence of conjugation frequency on the division cycle of Escherichia coli and flexneri cells.


Simulataneous determination of transferrin and albumin phenotypes in horses.


Transfer of second set response to immunologically immature rats.


Transport of uridine in Escherichia coli B and a showdomycin-resistant mutant.


Methylation of purified transfer RNAs by liver extracts from normal and mestranol-treated rats.


Reversal of inhibition of membrane-bound RNA synthesis in Escherichia coli infected with R23.


Studies on the release of N-acetylphenylalanyl-tRNA from its ribosomal complex: effect of size of poly(u).


The structural basis for functional inactivity of reconstituted 50-S ribosomal subunits of Escherichia coli.


Template waveform recognition applied to ECG-VCG analysis.


Studies in the sphingolipids series. XXXV. Separation and chemical characterization of the cerebrins from the yeast Saccharomyces cerevisiae.


Formyltetrahydrofolate synthetase.

Formyltetrahydrofolate synthetase.


Clustering algorithm for QRS and ST-T waveform typing.


Aging: alteration of DNA-protein information.


Duration of immunologic memory in mice primed at different ages.


Enzyme changes in ageing mammals.

Enzyme changes in ageing mammals.


Evaluation of a new system for recording by computer the findings at physical examination.


The problem oriented medical system--a progress report.


Serial extractions in orthodontic therapy: a literature review.


Chemical and physical properties of starch.


The influence of the automobile on rural health care, 1900-29.


Endocrine response after GnRH in luteal phase cows and cows with ovarian follicular cysts.


Galen's contribution to surgery.

Galen's contribution to surgery.


London coroner's inquests for 1590.

London coroner's inquests for 1590.


Foundation of the Orphans of Cholera Home by the Archbishop of Paris. Lithograph (circa 1843) after Louis-Joseph César Ducornet (1806-56).


Contributions of some early Russian scientists to the understanding of glycolysis.


Detection of anaerobic mycoplasmas in cell cultures.


Alexander Mavrocordatos (1641-1709): physician and statesman.


A simple and accurate method for the measurement of the growth of cell monolayers.


John Stainback Wilson and female medical education.


Recent developments in analytical electron microscopy.


Properties of a hamster tumor cell line grown in a glutamine-free medium.


Immunological liver disease.

Immunological liver disease.


Immunosuppressive therapy for chronic liver disease.


Alcohol and chronic liver disease.

Alcohol and chronic liver disease.


Iron and chronic liver disease.

Iron and chronic liver disease.


Hepatic encephalopathy.

Hepatic encephalopathy.


Diagnostic approaches in liver disease. The Bradshaw lecture 1973.


Impaired coagulation in the bleeding of chronic liver disease.


The Chelsea Physic Garden.

The Chelsea Physic Garden.


The relationship of hepatitis associated antigen (Australia antigen) and chronic active hepatitis--review of current literature.


Unidirectional air flow surgical isolator for hysterectomy of mice.


Denturism--illegal dentistry. A report.

Denturism--illegal dentistry. A report.


The effect of hydromassage on capillary strength.


Effects of mouth rinses with sucrose, glucose, fructose, lactose, sorbitol and Lycasin on the pH of dental plaque.


Sucrose content of saliva after consumption of various food products.


The American Pediatric Society. Presidential address to the American Pediatric Society, May 18, 1973 (Abraham Jacobi), (Job Lewis Smith), (Thomas Morgan Rotch), (William Osler).


What is new in our understanding of perinatal pulmonary problems? Presidential address to the Society for Pediatric Research, May 19, 1973.


Implanted silver-silver chloride magnesium power sources.


Acceptance of the Howland Award. Reflections on pediatric care (Kenneth Daniel Blackfan).


Presentation of the Howland Award to Louis K. Diamond.


Sociometric status and cognitive style in kindergarten children.


Review of flooding procedures (implosion) in animals and man.


Correlations between Hand Test variables and patrolman performance.


Performance of children with spina bifida manifesta on the Frostig Developmental Test of Visual Perception.


Bibliography related to use of instrumental aids in stuttering therapy: supplement I.


The growth promoting effect of cortisol on human fetal lung cells.


My debt to Osler.

My debt to Osler.


Memoir of Bernard C. Gettes 1912-73.

Memoir of Bernard C. Gettes 1912-73.


Deformity is a disease.

Deformity is a disease.


Memoir of Leon Kacher 1913-73.

Memoir of Leon Kacher 1913-73.


Memoir of James J. Ryan 1915-73.

Memoir of James J. Ryan 1915-73.


Memoir of Frederick R. Robbins 1897-1973.


Memoir of Samuel Emlen Stokes 1894-1972.


Introduction of Manfred Bleuler, M.D., for honorary fellowship.


The history of Neurology in the State of Virginia (1854-1973).


Medicare. B. Laboratory services by physicians. (Reference 6325.2 item 7C HIM 14).


Editorial. Horizon fever.

Editorial. Horizon fever.


Histochemical studies of specific dehydrogenases in the jejunum after thioctacid application.


Cerebral haemodynamics and metabolism in ischaemic disturbances of cerebral circulation.


Ultrasonic provocation of local Shwartzman-reaction.


Clinical studies on the pathogenesis of pernicious anaemia. IV. Immunological study of the duodenal juice.


History of intraocular implants.

History of intraocular implants.


The Australian and New Zealand College of Psychiatrists. Office bearers and Fellows and Members: May, 1973.


A note concerning non-uniform pool labeling.


Investigations on the mode of action of the combination sulfamethoxazole-trimethoprim.


Replication of DNA in mammalian chromosomes. II. Kinetics of 3H-thymidine incorporation and the isolation and partial characterization of labeled subunits at the growing point.


Prologue and epilogue of carbon dioxide therapy. Carbon dioxide as a physiological agent.


Deficiency of the second component of complement associated with anaphylactoid purpura and presence of mycoplasma in the serum.


Immune responsiveness to Mycobacterium leprae and other mycobacterial antigens throughout the clinical and histopathological spectrum of leprosy.


A naturally occurring human antibody to loops of Henle.


An experimental study using tissue culture medium as preservation and perfusion fluid.


Haemopoietic stem cells and progenitors of functional T-lymphocytes in the bone marrow of 'nude' mice.


Clinical and EEG investigations with CI-579 and CI-600 (quantitative pharmacoelectroencephalography and "sleep prints").


Lymphocyte activation. V. Quantitation of the proliferative responses to mitogens using defined T and B cell populations.


Fucidin in psoriasis. A double-blind study of twenty psoriatics over two periods of four weeks each.


On allergic contact dermatitis to virginiamycin.


Protein synthesis on ribosomes isolated from rat liver mitochondria: sensitivity to erythromycin.


RNA synthesis in isolated chloroplasts: characterisation of the newly synthesised RNA.


Membrane associated proteases in E. coli.


Recognition of tRNA by the ribosome. A possible role of 5 S RNA.


Activation of chicken pepsin by modification of its cysteine residue with o-nitrophenyl sulfenyl chloride.


Study of microbial ecology of Thai women with dermatophytosis.


A short history of dermatology in Lagos, Nigeria.


A double-blind comparison of fluphenazine and haloperidol in outpatient schizophrenic children.


Treatment of vitiligo with autologous thin Thiersch's grafts.


Icosahedral cytoplasmic deoxyriboviruses.


Comparative virology of the small RNA viruses.


Comparative aspects of togaviruses.

Comparative aspects of togaviruses.


Biogenesis of mitochondria. XXV. Studies on the mitochondrial genomes of petite mutants of yeast using ethidium bromide as a probe.


Martin J. Cattoni, D.D.S., M.S.D.

Martin J. Cattoni, D.D.S., M.S.D.


The effects of homologous bone and matrix, with and without marrow, on implanted dentin and cementum.


The birth of early infantile autism.

The birth of early infantile autism.


Osseous coagulum collection filter.

Osseous coagulum collection filter.


Childhood schizophrenia--what is it?

Childhood schizophrenia--what is it?


The National Society for Autistic Children in Britain.


Historical perspective on developmental deviations.


Advances in medicine.

Advances in medicine.


Advances in orthopaedic surgery.

Advances in orthopaedic surgery.


School phobia: a Babel of tongues.

School phobia: a Babel of tongues.


Control of gene function in bacteriophage T4. IV. Post-transcriptional shutoff of expression of early genes. The selective and sequential shutoff of synthesis of early T4 proteins in bacteria infected with DNA-negative mutants is under the active control of one or more T4-induced proteins. Selective shutoff of synthesis of early T4 proteins is accompanied by a selective degradation of distinct species of T4 mRNA. We present circumstantial evidence that selective degradation of mRNA is the cause, and not the consequence, of selective termination of expression of early T4 genes. The mutation sp62 inactivates the shutoff mechanism and prevents the selective degradation of distinct species of T4 mRNA.


Advances in gynaecology.

Advances in gynaecology.


Advances in anaesthesia.

Advances in anaesthesia.


Advances in the treatment of rheumatic diseases.


'More fashionable than scientific'. Sir Henry Holland, Bt, M.D., F.R.C.P., F.R.S. (1788-1873).


Crohn's disease. Burrill Bernard Crohn (born 1884).


Obituary. Robert Helmer MacArthur. (1930-1972).


Autonomic innervation of canine urinary bladder. Cholinergic and adrenergic contributions and interaction of sympathetic and parasympathetic nervous systems in bladder function.


The isolated ureter. A model for study of ureteral rejection.


Surgical effects of rotation of ureter. An experimental study.


Arteriography during ex vivo renal perfusion. A complication.


Turner-Warwick urethroplasty for membranous urethral stricture. Revised technique.


Use of trimethoprim-sulfamethoxazole in chronic prostatitis.


Spontaneous rupture of kidney associated with renal papillary necrosis.


Eugene Fuller, M.D. (1858-1930).

Eugene Fuller, M.D. (1858-1930).


The amygdala: historical and functional analysis. The amygdala, part of the limbic system, is a small collection of neurons located in the ventral temporal lobe, and can be divided into two morphologically and functionally distinct nuclei - the corticomedial, a phylogenetically old group, and the basolateral, a phylogenetically more recent group. Both divisions of the amygdala have extensive interconnections with the hypothalamus, the corticomedial nucleus via the stria terminalis and the basolateral nucleus via the ventral amygdalohypothalamic pathway. The amygdala receives input from the orbital frontal cortex, the piriform cortex, the hypothalamus, the thalamus, and all sensory modalities as well as from the other structures of the limbic system. Early theories positing strictly emotional, olfactory, or visceral functions for the amygdala are at best incomplete. An intact amygdala seems to be essential for the successful performance of behavior patterns such as instinctive food getting and instinctive defensive reactions that are necessary for the survival of the individual organism and the species. Ablation of the amygdala produces many behavioral deficits that center around the inability to integrate changes in reinforcement contigencies into new behavior patterns.


Obituaries. In memory of Professor Mieczyslaw Minkowski. 1884-1972.


Gonadal function in hypophysectomized dogs with glandular transplants in the sella turcica.


Analysis of mercury compounds by gas-liquid chromatography utilizing an electron capture detector.


American Association of Anatomists 1973-1974.


The substructure of crystalloids in secretory granules of dog pancreatic islet B cells.


Processing histological specimens. A rapid method.


Directory of schools.

Directory of schools.


Prevalence of toxoplasmosis in a Canadian city.


Autotrophism of an "intracellular parasite" Mycobacterium leprae.


The amino acid sequence of the N-terminal region of some 30S ribosomal proteins from Escherichia coli and Bacillus stearothermophilus: homologies in ribosomal proteins.


Suppressive therapy in the control of bilharziasis: a comparative trial in African school children.


The pattern of neurological disease in African children in Kenya. A review of 906 cases.


Nasopharyngeal suture.

Nasopharyngeal suture.


On the evolution of treatment for otogenic brain abscess.


Effect of the growth rate on the level of the DNA-dependent RNA polymerases in Saccharomyces cerevisiae.


Precursors of stable RNA accumulated in a mutant of E. coli.


Biosynthesis of lipid-linked sugars in Saccharomyces cerevisiae.


Regulation of wall synthesis during Saccharomyces cerevisiae cell cycle.


In vivo biosynthesis of murein-lipoprotein of the outer membrane of E. coli.


Distribution of murein-lipoprotein between the cytoplasmic and outer membrane of Escherichia coli.


The N-terminal amino acid sequence of bovine pepsin (EC 3.4.4.1) and the sequence overlapping the activation fragment.


The sequential nature of in vitro formation of 23 S RNA-50 S protein complexes of Escherichia coli: dependence on temperature and magnesium.


On the adaptability of man's hand (with reference to the equiangular curve).


Paralytic claw fingers--a graft tenodesis operation.


Gunshot wounds of the hand.

Gunshot wounds of the hand.


Gillies "cocked hat" reconstruction for total loss of ulnar four fingers.


The "grasping" technique for tendon repair.


Douglas Leslie Savill, M.B., Ch.B. Edinburgh, F.R.C.S.Edinburgh.


Changes in survival of Escherichia coli K-12 cells as a function of the medium in which they are X-irradiated: a rec and exr gene-dependent phenomenon.


Revival of an ancient medicine. Acupuncture.


Toxoplasmosis: a review.

Toxoplasmosis: a review.


Epidemiology of the principal systemic mycoses of man and lower animals and the ecology of their etiologic agents.


Inapparent rabies virus infection of the central nervous system.


Characteristics of Greek Isolates of Agrobacterium tumefaciens (E. F. Smith & Townsend) Conn.


Serine dehydratase from bacteria.

Serine dehydratase from bacteria.


Relationships between estimates of binding of antimicrobial agents by macromolecules, based on physicochemical and microbiological data: cetylpyridinium chloride and polyethylene glycol.


Comparison of plating and most probable number techniques for the isolation of staphylococci from foods.


Microbial changes leading to the spoilage of hung pheasants, with special reference to the clostridia.


The use of semi-automatic pipettes in the viable counting of bacteria.


Analysis of the intracellular amino acid pool and proteins from whole cells of Rhizobium japonicum.


A selective medium for enumerating salt requiring vibrio spp. from Wiltshire bacon and curing brines.


The survival of infectious bronchitis (IB) virus in an iodophor disinfectant and the influence of certain components.


The influence of temperature and moisture on the disinfecting activity of methyl bromide on infected poultry litter.


Viable cell and electronic particle count.


Effects of some beta-lactam antibiotics on the morphology of some beta-lactamase and non-beta-lactamase producing strains of gram negative bacteria.


Light and electron microscope localization of binding sites of antibodies against ovine luteinizing hormone and its two subunits in rat adenohypophysis using peroxidase-labeled antibody technique. The binding sites of antisera generated in the guinea pig against ovine luteinizing hormone (oLH) and its two subunits (oLHalpha and oLHbeta) have been localized in rat anterior pituitaries taken from normal or castrated males and from ovariectomized females with the peroxidase-labeled antibody method, using light and electron microscopy. With the light microscope, the cells positive with antiserum to ovine luteinizing hormone (A-oLH) were violet after the Alcian blue-periodic acid-Schiff (AB-PAS) staining; they were also positive for A-oLHalpha and for A-oLHbeta and, from castrated males, they displayed an increased affinity for A-oLHbeta. Another cell type which was blue after the AB-PAS method reacted with the A-oLHalpha only; these cells, presumably thyrotropic cells, were retracted after castration and, besides their affinity for A-oLHalpha, acquired an affinity for A-oLHbeta. As seen through the electron microscope, two cell types were positive for A-oLH, A-oLHbeta, and A-oLHalpha and may be identified as luteinizing hormone-secreting cells. Type A cells were characterized by two classes of rounded, secretory granules. Type B cells were smaller and contained only small secretory granules. 1 mo after the rats were castrated the type A cells were hypertrophied and vacuolized. In both cases the secretory granules were the main sites of the antigenicity with the three antisera. A positive reaction was also found in the cytoplasm, particularly in hypertrophied cells from ovariectomized females and with A-oLHbeta. The cisternae of the rough endoplasmic reticulum were usually negative, except in highly degranulated cells from ovariectomized females and with A-oLHbeta.


The "Barnum effect" and acceptance of negative personal evaluation.


Preferred interpersonal distance as a function of locus of control orientation in chronic schizophrenics, nonschizophreic patients, and normals.


The structure of a simple Z line.

The structure of a simple Z line. The structural simplicity of the Z line in fish muscle fibers allows direct visualization of its basic geometry. Models which postulate termination of the I filaments at the edges of the Z line and the direct linkage of I filaments belonging to the two adjacent sarcomeres by Z filaments crossing the whole width of the Z line give the best fit to the electron micrographs. The structure of fish Z lines is not significantly altered by the use of different fixation procedures and by changes in sarcomere length.


Synthesis of 5-substituted quinazolines as potential antimalarial agents.


New asparagine analogs.

New asparagine analogs.


Penetration into host cells of naked, partially injected (post-FST) DNA of bacteriophage T5. The experiments presented here suggest that the naked post-FST DNA, attached to the bacteria after a centrifugation at 6,000 x g of Escherichia coli-T5 complexes arrested at the FST stage, can be injected into the host cell if protein synthesis is allowed. This results from the observation that the production of infectious centers by this naked DNA is sensitive to DNase or moderate shearing treatments. The process of injection seems to be the same as that for DNA normally rolled in an adsorbed capsid.


Effects of the decay of incorporated radioactive phosphorus on the transfer of the bacteriophage SP82G genome. The last genetic markers to be transferred during bacteriophage SP82G infection have a higher sensitivity to the decay of incorporated radioactive phosphorous ((32)P) than those which are located on the proximal end of the genome. If (32)P decay is permitted to take place after DNA transfer is complete (in frozen infective centers) and in the absence of DNA replication, no dependence of marker sensitivity on map position is observed. These results indicate that the decay of incorporated (32)P leads to damages that prevent the efficient transfer of portions of the genome distal to the lesion. At 4 C, failure to transfer some portion of the genome occurs in 49% of all lethal events. Even though damages that prevent transfer of the genome are in themselves lethal, they do not prevent rescue of genetic markers on portions of the genome that are transferred. The portion of the genome that is transferred, is transferred at the same rate as an undamaged genome. We interpret these results to mean that double-strand breaks in the DNA are the lesions that prevent distal transfer and that single-strand breaks have little or no effect on the transfer of the bacteriophage SP82G genome.


Host-mediated repair of discontinuities in DNA from T4 bacteriophage. Discontinuities of T4 DNA which are caused by excision of UV-damaged areas, by decay of (32)P atoms, or which are present in DNA from rII(-)lig(am) (-) phage produced in a host nonpermissive for amber mutants are all repaired by bacterial enzymes after infection in the presence of chloramphenicol. Escherichia coli DNA polymerase I participates in the host-mediated repair, but an approximately 20-fold variation in the levels of host polynucleotide ligase does not affect either the kinetics or the extent of repair observed. Upon removal of chloramphenicol, host-repaired DNA from UV-irradiated phage undergoes a secondary cycle of breakage, which ultimately results in solubilization of most of the phage DNA. If the cells are co-infected with nonirradiated helper phage, the secondary breaks are repaired and the continuity of the polynucleotide chain is restored. The close coincidence in the extent of primary and secondary breakage suggests that phage-coded enzymes recognize and excise areas improperly repaired by the host. In contrast to host-mediated repair, repair mediated by rescuing phage probably restored functionality to the damaged DNA.


Effect of a gene-specific suppressor mutation (das) on DNA synthesis of gene 46-47 mutants of bacteriophage T4D. Mutants in genes 46 and 47 of bacteriophage T4 exhibit early cessation of DNA synthesis, inability to form a normal rapidly sedimenting DNA intermediate (200S), reduced genetic recombination, and reduced viable phage production. A gene-specific suppressor mutation called das partially restores many of the pleiotropic effects of gene 46-47 mutants (13). Our results indicate that this partial suppression by das is associated with (i) the synthesis of a small fraction of DNA containing long single chains not detectable in 46-47 infection and (ii) a decrease in an "early" function which participates in the degradation of DNA synthesized in the absence of 46-47 functions. However, das does not restore the formation of a normal rapidly sedimenting (200S) DNA intermediate.


Variable transforming activity of nonglucosylated and fragmented T4 DNA. Nonglucosylated and fragmented T4 DNA shows a gene-specific variation in transformation efficiency.


Transforming ability of a T4 RNA-DNA copolymer. A coliphage T4-specific RNA-DNA copolymer is genetically competent to transform a marker in gene 43, the DNA polymerase.


Rickets in Appalachia during the early years; an interview.


Evaluation of the Treponema pallidum haemagglutination test.


A highly mucoid isolate of Serratia marcescens.


Effects of fimbria-fornix lesion on avoidance conditioning in the rat.


Neuroendocrine influences on visual discrimination and reversal learning in the albino and hooded rat.


Effect of septal lesions on retention of negative contrast.


Diurnal drinking of rats with limbic system lesions maintained in an open vivarium.


DRL training and performance following anterior, posterior, or complete septal lesions in infant and adult rats.


Fear behavior and passive avoidance deficits in mice with amygdala lesions.


Wood-gnawing in rats following cortical, olfactory bulb or limbic lesions.


Archistriatal lesions enhance tonic immobility in the chicken (Gallus gallus).


Dr. von Sallman honored.

Dr. von Sallman honored.


Hedwig S. Kuhn, M.D., dies.

Hedwig S. Kuhn, M.D., dies.


Derrick Vail, M.D., dies.

Derrick Vail, M.D., dies.


Evaluation of indicator dilution curve areas.


Effect of "osmotic stabilizers" and glycerol on yeast cell envelopes.


Dye dilution technique in the investigation of renal blood flow in solitary cysts.


Herman Boerhaave and the history of vessels carrying aqueous humor from the eye.


Intracranial hypertension and papilledema associated with nalidixic acid therapy.


The American Journal of Roentgenology, Radium Therapy and Nuclear Medicine.


The first Walter Bradford Cannon lecture before the Society of Gastro-intestinal Radiologists.


The Society of Gastro-Intestinal Radiologists.


In vitro culture of bovine embryos.

In vitro culture of bovine embryos.


Renal tubular acidosis after kidney transplantation. Natural history and significance.


Carbon monoxide effect on exercise-induced angina pectoris.


Letter: Serratia marcescens endocarditis.


Annotated answers to the 1902 examination on Osler's Principles and Practice of Medicine.


Percutaneous transtracheal aspiration in the diagnosis of anaerobic pulmonary infection.