Expression of the viral thymidine kinase gene in herpes simplex virus-transformed L cells. In these studies, the expression of thymidine kinase (TK) in normal and herpes simplex virus (HSV)-transformed L cells has been compared. In asynchronously dividing cultures of L cells, the TK activity rose and declined rapidly and coordinately with DNA synthesis. When net cell increase stopped, TK activity was at a minimum. In contrast, TK activity of HSV-transformed cells remained at a minimum during rapid DNA synthesis and gradually increased as the rate of DNA synthesis decreased. When net cell increase stopped, TK activity was at a maximum. In synchronous cultures of L cells, TK activity rose and fell coordinately with the rate of DNA synthesis. In synchronous cultures of HSV-transformed cells, no increase in TK activity was observed during the period of rapid DNA synthesis, i.e., the S phase. These findings indicated that the viral TK gene in HSV-transformed cells was not placed under the control of the cellular mechanisms which normally modulate the host cell TK gene. Lytic infection of HSV-transformed cells with a TK(-) mutant of HSV-1 induced a four-to fivefold increase in viral TK. The TK of HSV-1 was induced in the HSV-1-transformed cells and HSV-2 in the HSV-2-transformed cells by this TK(-) mutant. The same infection of normal L cells decreased the cellular TK activity by 80%. This stimulation, rather than inhibition, suggest that the viral gene in HSV-transformed cells retain some of its original viral characteristics.


Envelope proteins of vesicular stomatitis virus: effect of temperature-sensitive mutations in complementation groups III and V. All five major viral proteins were synthesized in chicken embryo cells infected with vesicular stomatitis virus temperature-sensitive (ts) mutants of complementation groups III and V and maintained at the nonpermissive temperature. The distribution of these proteins among cytoplasmic cellular fractions separated on discontinuous sucrose gradients was identical for wild-type and tsIII-infected cells. Strikingly different patterns were observed for the G protein in gradients from cells infected by tsV mutants; very little, if any, G protein was found in the lightest fraction. Pulse and chase experiments with wild-type, virus-infected cells showed that protein G moves from the heaviest to the lightest fraction before being incorporated into the virion. After shift down to the permissive temperature (30 C), G protein synthesized at 39.6 C in tsV-infected cells became associated with the lightest cellular fraction and later with the released virions. In contrast, M protein, synthesized at 39.6 C in tsIII-infected cells, was not incorporated into the virions after shift down. These data strongly suggest, first, that M protein is encoded by the vesicular stomatitis gene III, and second, that incorporation of G protein in the lightest cellular fraction is a necessary step of vesicular stomatitis maturation. This step is impaired by tsV mutations.


Effects of actinomycin D on the cytopathology induced by poliovirus in HEp-2 cells. One possible mechanism of virus-induced cell damage is that the redistributed (released) lysosomal enzymes produce the cytopathic effect during cytolytic types of infections such as poliovirus in HEp-2 cells. To determine if the lysosomal enzyme redistribution and cell damage are host-cell directed, we studied sensitivity of these events to the action of actinomycin D. By the use of actinomycin D at concentrations producing the least toxicity but maximal effectiveness in shuting down cell RNA synthesis, it was shown that the cytopathic effect and enzyme redistribution were not inhibited and, therefore, not directly controlled and induced by the cell genome in response to the virus infection. Evaluation of cytopathic effect by a phase contrast microscopy method detected changes earlier than the erythrocin B uptake method.


Analysis of endonuclease R-EcoRI fragments of DNA from lambdoid bacteriophages and other viruses by agarose-gel electrophoresis. By means of agarose-gel electrophoresis, endonuclease R.EcoRI-generated fragments of DNA from various viruses were separated, their molecular weights were determined, and complete or partial fragment maps for lambda, phi80, and hybrid phages were constructed.


Proteolytic cleavage of subunits of the nucleocapsid of the paramyxovirus simian virus 5. The protein subunits of the nucleocapsid of the parainfluenza virus simian virus 5 isolated from infected cells after dispersion with trypsin, chymotrypsin, or ficin are cleaved proteolytically. The molecular weights of the subunits which result from cleavage depend on the enzyme used, but are around 43,000, compared to the native subunit of 61,000. In most instances cleavage of the subunit appears to be due to the protease used to disperse the cell, and follows cell disruption. Nucleocapsids composed of native, uncleaved subunits can frequently be obtained from infected cells dispersed without a proteolytic enzyme; however, cleavage occasionally occurs even under those conditions, indicating that cellular proteases can at times cleave this protein. Nucleocapsids containing uncleaved subunits can be isolated from cells persistently infected with simian virus 5, indicating that persistent infection is not invariably associated with intracellular cleavage of this protein. Nucleocapsids composed of native subunits are hydrophobic, whereas those composed of the cleaved subunit can be dispersed in aqueous solution. It is suggested that the portion of the molecule removed by cleavage may be responsible for a specific interaction during virus assembly between the nucleocapsid and those areas of plasma membrane which contain the non-glycosylated viral membrane protein, which is also hydrophobic. An amino acid analysis of native and cleaved subunits has been done. The portion of the subunit removed by cleavage does not have a high proportion of hydrophobic residues, suggesting that those present are arranged together to form a hydrophobic domain. The N termini of both the native and cleaved subunits are blocked. This suggests that the portion of the molecule which is externally disposed and removed by cleavage contains the C terminus, and the cleaved subunit which reacts with the viral RNA contains the N terminus.


Structure of the mouse mammary tumor virus: characterization of bald particles. The polypeptide, antigenic, and morphological structure of the mouse mammary tumor virus was studied following protease digestion of intact virions. Intact, untreated virions (rho = 1.17 g/ml) had characteristic envelope spikes, five major polypeptides, and were precipitated by antisera against gp52. Two of the major polypeptides, with molecular weights of 52,000 (gp52) and 36,000 (gp36), had carbohydrate moieties. Protease treatment resulted in spikeless, "bald" particles (rho = 1.14 g/ml), which had altered surface antigenicity and which contained neither gp52 nor gp36. These data indicated that gp52 and gp36 were on the viral envelope. Bald particles retained a 28,000 dalton polypeptide (p28) which was proposed as the major internal polypeptide.


Hemagglutination-inhibition: rapid assay for neuraminic acid-containing viruses. Influenza virus particles bind rapidly to vesicular stomatitis, Sindbis, or Rauscher murine leukemia virus particles, forming mixed aggregates demonstrable by electron microscopy. The normal hemagglutinating property of influenza virus is inhibited by these viruses, providing a rapid quantitative assay. Prior treatment with neuraminidase blocks the ability of other viruses to inhibit influenza virus hemagglutination.


Characterization of polyoma DNA-protein complexes. I. Electrophoretic identification of the proteins in a nucleoprotein complex isolated from polyoma-infected cells. A study was undertaken to examine polyoma DNA-protein complexes. A biophysical characterization of the complexes was made, and the proteins found in such complexes were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A comparison was made between a 52S nucleoprotein complex isolated from nuclei of 26-h polyoma-infected cells and a 28S virion core complex ejected out of mature virus particles. It was found that both complexes were reduced to a 20S viral DNA component plus free protein after incubation in 1 M NaCl or Sarkosyl. Treatment of the complexes with either Pronase or 0.5 M NaCl resulted in only partial removal of proteins from the viral DNA. After fixation in formaldehyde, the 52S nucleoprotein complex had a buoyant density of 1.45 g/cm(3), and the virion core complex had a buoyant density of 1.59 g/cm(3). Sodium dodecyl sulfate-polyacrylamide gel profiles of purified polyoma virion proteins, used as a reference marker, demonstrated three capsid proteins, V1 to V3, as well as four histones, V4 to V7, which constituted about 7% of the total virion protein. Electrophoretic analysis of the proteins comprising the 52S nucleoprotein complex revealed that the same seven proteins present in the mature virion were also found in this complex. However, the ratios of the proteins in the complex were quite different from that of the mature virion, with the four histones comprising 48% of the total complex protein. A pulse-chase experiment of the nucleoprotein complex demonstrated that the 26-h complex was chased into mature virions.


Molecular weight of two oncornavirus genomes: derivation from particle molecular weights and RNA content. Sedimentation analysis and intensity fluctuation spectroscopy have been used in conjunction with the Svedberg equation to determine the particle molecular weights of Rous sarcoma virus (Prague strain) and avian myeloblastosis virus (BAI strain). The molecular weights of these two viruses are (294 +/- 20) x 10(6) and (256 +/- 18) x 10(6), respectively. Values for the molecular weight of the RNA contained in each particle have been calculated as (5.58 +/- 0.5) x 10(6) and (5.88 +/- 0.5) x 10(6). Since the proportion of the viral RNA represented by 4 to 7S low-molecular-weight material is known, the molecular weight of the 60 to 70S genomes may be calculated to lie in the range (3.8 +/- 0.3 to 4.8 +/- 0.4) x 10(6) for both particles. These estimates for the molecular weight of the 60 to 70S genome are much lower than previous estimates and fall within the range of current estimates of the size of a single 35S subunit. The implications of this finding are discussed in terms of current theories for the structure of the genome of RNA tumor viruses.


Nucleic acid homology of murine type-C viral genes. The nucleic acid sequence homology between various murine, endogenous type-C viruses (three host range classes of BALB/c virus, the AT-124 virus, and the CCL 52 virus) and two laboratory strains of murine leukemia virus (Rauscher and Kirsten) was determined by DNA:RNA hybridization. The viral sequences exhibit varying degrees of partial homology. DNA:DNA hybridizations were performed between [(3)H]DNA probes prepared from N- and X-tropic BALB/c endogenous viruses and cellular DNAs from BALB/c, NIH Swiss, and AKR inbred mouse strains as well as from California feral mice and the Asian mouse subspecies Mus musculus molossinus and M. musculus castaneus. All of these strains of mice are shown to possess multiple (six to seven per haploid genome), partially related copies of type-C virogenes in their DNAs. Thermal melting profiles of the DNA:RNA and DNA:DNA hybrids suggest that the partial homology of the viral nucleic acid sequences is the result of base alterations throughout the viral genomes, rather than the loss of discrete segments of viral sequences.


Avian tumor virus proteins and RNA in uninfected chicken embryo cells. The content of proteins P19 and P15 (mol wt 19,000 and 15,000, respectively) of avian leukovirus in various types of uninfected chicken embryos has been determined by radioimmunoassay. All chicken embryos examined, including embryos which have thus far been classified as group specific (gs) antigen negative by complement fixation tests, contained these viral proteins as well as P27 as previously reported. The embryos known as "gs antigen-positive" type contained about five times as much of these viral proteins as did the "gs antigen-negative" type. The ratio of the three viral proteins was similar for all types of embryos, suggesting that the genes for these proteins are coordinately controlled. In contrast to the relatively high levels of viral internal proteins in gs antigen-negative cells, the amounts of virus-specific RNA detectable by molecular hybridization were extremely low. The levels of helper activity, which presumably reflect the level of viral envelope glycoprotein, were also generally low or undetectable in these cells. Thus, the expression of the gene for envelope glycoprotein does not appear to be controlled coordinately with the genes for viral internal proteins.


Isolation and characterization of revertant cell lines. VI. Susceptibility of revertants to retransformation by simian virus 40 and murine sarcoma virus. The susceptibility of two classes of revertants of Simian virus 40 (SV40)-transformed 3T3 cells to retransformation by SV40 or murine sarcoma virus (MSV) was studied. Both serum-sensitive and density-sensitive revertants are not retransformable by SV40. MSV can transform both types of revertants. The MSV-transformed revertants grow to high cell densities and form colonies when suspended in semi-solid methylcellulose medium, but are unable to grow in 1% calf serum. The MSV-transformed revertants produce infectious MSV and murine leukemia virus and possess the same number of chromosomes as the untransformed revertants.


Levels of rat cellular RNA homologous to either Kirsten sarcoma virus or rat type-C virus in cell lines derived from Osborne-Mendel rats. DNA transcripts from V-NRK and RT21c rat type-C viruses were found to differ in their sequence homology to Kirsten and Harvey sarcoma viruses. V-NRK DNA transcripts consistently had homology to Kirsten and Harvey sarcoma virus, whereas RT21c DNA transcripts did not. To explain the differences, the nucleic acids and structural proteins of the two type-C viruses, released from each of two cell lines derived from Osborne-Mendel rats, were analyzed by molecular hybridization and competition radioimmunoassays. The p30 and p12 structural proteins of the two viruses were found to be highly related immunologically. In the V-NRK virus preparation, two sets of distinct RNA sequences were found in approximately equal amounts. One set is homologous to Ki-SV, and the other homologous to RT21c. In contrast, the RT21c virus preparation was found to contain a different ratio of these sequences. In this case the RT21c-like RNA sequences are present in 100-fold excess as compared to the additional Ki-SV specific sequences. Both NRK and RT21c cells contain in their DNA the full complement of Ki-SV homologous sequences, but NRK cells express much higher levels of these Ki-SV sequences in their RNA. These additional sequences, not homologous to RT21c, which are detected in uninfected NRK cellular RNA or V-NRK rat virus, could also be detected in the 60-70S RNA from a Moloney mouse type-C virus released from the NRK cells infected with the Moloney type-C virus. The results suggest that type-C viruses released from NRK cells incorporate species of RNA present in NRK cells which are homologous to Kirsten and Harvey sarcoma viruses. Either these sequences are of cellular origin, or rat cells contain two endogenous viruses with completely distinct nucleic acid sequences.


Extent of double strandedness in avian myeloblastosis virus RNA. The extent of double strandedness of avian myeloblastosis virus 70S RNA has been determined from fluorescence measurements of the intercalation of ethidium bromide. We have shown that 50% of the nucleotides of 70S RNA in solution are in a stable helical configuration. This value does not include small helical regions that are too unstable to permit intercalation of the dye. The avian myeloblastosis virus RNA as it exists within the virion has the same degree of helicity as the free 70S RNA. Heating the free 70S RNA to 55 or 70 C, followed by cooling, does not measurably change the degree of helicity; the subunits therefore have as much helicity as the parent molecule.


Mechanistic independence of avian myeloblastosis virus DNA polymerase and ribonuclease H. Differential inhibition conditions were established for the DNA polymerase and RNase H activities of avian myeloblastosis virus (AMV) with ether-disrupted AMV and a purified enzyme preparation. The RNase H activity of ether-disrupted AMV with (rA)(n).(dT)(n) and (rA)(n).(dT)(11) as substrates was inhibited 80 to 100% by preincubation with NaF at a final reaction concentration of 27 to 30 mM. Under these conditions, the DNA polymerase activity was inhibited only 0 to 20%. Similar inhibitions were found with exogenous Rous sarcoma virus 35S and 70S RNA.DNA hybrid and phiX174 DNA.RNA hybrid as substrates. Studies were also performed with a purified enzyme preparation, in which the two activities essentially co-purified. The RNase H activity was inhibited >80% by 150 mM KCl with three different hybrid substrates, whereas the DNA polymerase activity was uninhibited. The DNA polymerase was completely inactivated by heat denaturation at 41 C or by omission of the deoxytriphosphates from the reaction mixture; the RNase H remained active. These differential inhibition conditions were used to compare the size of the DNA product synthesized with and without simultaneous RNase H action and to examine the effect of inhibition of the DNA polymerase on the size of the RNase H products. The size of the products of one activity was not affected by inhibition of the other activity. These results suggest that the AMV DNA polymerase and RNase H are not coupled mechanistically.


Simian virus 40-host cell interactions. II. Cytoplasmic and nucleolar accumulation of simian virus 40 virion protein. We have used immunofluorescence in parallel with transmission and scanning electron microscopy to characterize the unusual cytoplasmic and nucleolar accumulation of Simian virus 40 (SV40) virion protein (C antigen) at restrictive temperatures (39 to 41 C) in monkey cells infected with a temperature-sensitive mutant of SV40 defective in virion assembly, tsB11. Cytoplasmic and nucleolar accumulation of C antigen did not occur in wild-type-infected cells at any temperature. Wild-type- and tsBll-infected cells were not distinguishable at 33 C by immunofluorescence or electron microscopy. Temperature-shift experiments using metabolic inhibitors of DNA (cytosine arabinonucleoside, 20 mug/ml), RNA (actinomycin D, 5 mug/ml), and protein synthesis (cycloheximide, 2 x 10(-4) to 10 x 10(-4) M) were used to investigate the requirements for ongoing DNA, RNA, and protein synthesis in the distribution of virion protein between the nucleus, nucleolus, and cytoplasm. The transport of C antigen from the nucleolus and cytoplasm into the nucleus was complete after a temperature shift-down (41 and 39 to 33 C). Limited virus particle formation occurred after the shift-down in the presence of actinomycin D and cycloheximide, indicating some of the 39 to 41 C synthesized virion protein could be used for capsid assembly at 33 C in the absence of further virion protein synthesis. Nucleolar and cytoplasmic accumulations of C antigen occurred in the absence of drugs after a shift-up (33 to 39 C and 41 C) indicating a continuous requirement for the tsB11 mutant function. Furthermore, the virion protein synthesized at 33 C remained confined to the nucleus when the cells were shifted to 39 and 41 C in the presence of actinomycin D or cycloheximide. In the presence of cytosine arabinonucleoside, however, the virion protein accumulated in large aggregates in the nucleus and nucleolus after the shift-up, but did not migrate into the cytoplasm as it did in drug-free tsB11-infected control cells. Colchicine (10(-3) M) had no effect on the abnormal accumulation of C antigen during shift-up or shift-down experiments suggesting that microtubular transport plays little if any role in the abnormal transport of tsB11 virion protein from cytoplasm to nucleus. Although virus particles were never observed by electron microscopy and V antigen was not detected by immunofluorescence at 39 or 41 C in tsB11-infected cells, dense amorphous accumulations were formed in the nucleoli and cytoplasm. We suggest that the tsB11 function is continuously required for the normal transport of SV40 virion protein between the cytoplasm, nucleolus, and nucleus and for the assembly of capsids and virions. Several possible mechanisms for the altered tsB11 function or protein are discussed. One of the virion proteins may also be involved in some presently undetermined nucleolar function during SV40 productive infection.


Properties and location of poly(A) in Rous sarcoma virus RNA. The poly(A) sequence of 30 to 40S Rous sarcoma virus RNA, prepared by digestion of the RNA with RNase T(1), showed a rather homogenous electrophoretic distribution in formamide-polyacrylamide gels. Its size was estimated to be about 200 AMP residues. The poly(A) appears to be located at or near the 3' end of the 30 to 40S RNA because: (i) it contained one adenosine per 180 AMP residues, and because (ii) incubation of 30 to 40S RNA with bacterial RNase H in the presence of poly(dT) removed its poly(A) without significantly affecting its hydrodynamic or electrophoretic properties in denaturing solvents. The viral 60 to 70S RNA complex was found to consist of 30 to 40S subunits both with (65%) and without (approximately 30%) poly(A). The heteropolymeric sequences of these two species of 30 to 40S subunits have the same RNase T(1)-resistant oligonucleotide composition. Some, perhaps all, RNase T(1)-resistant oligonucleotides of 30 to 40S Rous sarcoma virus RNA appear to have a unique location relative to the poly(A) sequence, because the complexity of poly(A)-tagged fragments of 30 to 40S RNA decreased with decreasing size of the fragment. Two RNase T(1)-resistant oligonucleotides which distinguish sarcoma virus Prague B RNA from that of a transformation-defective deletion mutant of the same virus appear to be associated with an 11S poly(A)-tagged fragment of Prague B RNA. Thus RNA sequences concerned with cell transformation seem to be located within 5 to 10% of the 3' terminus of Prague B RNA.


Replication process of the parvovirus H-1. IV. H-1-specific proteins synthesized in synchronized human NB kidney cells. The synthesis of two virus-induced proteins, VP1 (mol wt 92,000) and VP2' (mol wt 72,000), was detected in the cell and in purified virions from H-1 parvovirus propagated in synchronous cell cultures.


Murine type-C virus group-specific antigens: interstrain immunochemical, biophysical, and amino acid sequence differences. The 30,000-molecular-weight internal protein, p30, was purified from seven strains of mouse type-C viruses. The individual p30's showed variation in isoelectric points and also intrastrain heterogeneity. The individual p30's could be distinguished by peptide map and quantitative complement fixation techniques with relatedness estimates of >95%. Amino terminal sequence analysis showed variability at position 4 for several p30's with complete homology otherwise through 24 residues. The intrastrain heterogeneity in p30 isoelectric points could not be explained by common contaminants, as shown by peptide mapping, and is more likely based on post-transcriptional modifications. These data provide a chemical basis for the recently described type-specific immunological properties of individual p30's.


Plaque formation with simian virus 40: enhancement by dimethyl sulfoxide. Dimethyl sulfoxide (DMSO) added to agar overlays during plaque assays of simian virus 40 (SV40) in CV1 monkey cells increases the plaque size and number and enables plaques to be read several days earlier than usual. DMSO appears to act during development of plaques, perhaps by causing cell lysis at smaller burst sizes in the presence of near-lethal DMSO concentrations. It does not act synergistically in determining virus inactivation with UV light and is equally effective on wild type and a late mutant of SV40.


Differential effect of phenethyl alcohol on mycoplasmas and enveloped viruses. Mycoplasmas are totally inactivated by a 20-min treatment with 1% phenethyl alcohol, whereas suspensions of enveloped viruses resist the same treatment. This treatment has proved successful in eliminating mycoplasma contamination of a virus suspension.


Type-C RNA virus gene expression in human tissue. Partially purified fractions of human tissues have been analyzed by competition radioimmunoassay for the presence of two of the principle structural components of type-C RNA viruses, the major core protein (p27 to p30) and the major envelope glycopeptides (gp69/71). Screening of tissues was carried out by use of a heterologous assay system of (125)I-labeled Rauscher murine virus p30 antigen and anti-RD 114 virus serum which was found to detect a class of interspecies determinants common to murine, feline, and primate viruses. A competitor with the same apparent affinity for antibody binding as that of purified viral core proteins was found in relatively high concentration in tissues from patients with systemic lupus erythematosus, in some neoplastic tissues, and also in normal human tissues. This competitor from a lupus spleen chromatographed on phosphocellulose and showed size fractionation during gel filtration similar to known p27 to p30 viral proteins. An immunologically reactive protein was also demonstrated by immunodiffusion and by immunoprecipitation of (125)I-labeled human protein with anti-RD 114 p28 serum. Analysis of these human competitor proteins with homologous assay systems of viral core proteins and corresponding antisera showed that all, including the normal tissue extracts, appear similar to core proteins of known viruses, especially the RD 114 and woolly monkey species. A hypothesis suggested by these data is that many, if not all, humans harbor at least part of the genome of one or more type-C viruses, the properties of which are similar to those of viruses from other mammalian species, particularly primates.


In vitro radioisotopic labeling of proteins associated with purified polyoma virions. An in vitro procedure using [(14)C]formaldehyde and sodium borohydride was used to label the proteins of purified polyoma virions. This method, which labeled the three capsid proteins and the four internal histones of polyoma virus, did not alter the biological and biophysical characteristics of the virus. In addition to the seven viral proteins, five additional radioactive peaks were resolved on polyacrylamide gels. Four of these peaks could be attributed to growing the virus in the presence of serum. The fifth peak appears to be a nonhistone host-contributed protein made before infection.


Screening for hyperlipidemia in childhood.


Islet cell hyperinsulinism in adults and children.


Pneumocystis carinii pneumonia in an adopted Vietnamese infant. A case of diffuse, fulminant disease, with recovery.


Phosphoesterases of hemolytic streptococci.


Epidemiology of myxo- paramyxovirus infections among cynomolgus monkeys imported for laboratory use.


Selective adsorption of serum proteins to aerosil.


The effects of amino acids and metals on the infectivity of poliovirus ribonucleic acid.


Growth characteristics of Bordetella pertussis in the chick tracheal organ culture.


Production of mouse interferon with high titers in a large-scale suspension culture system.


Effect of a lactobacillus product administration on the anaerobic intestinal flora of aged adults.


Enhanced production of interferon by temperature shift-down from 37 C to 25 C in rabbit cell cultures stimulated with Newcastle disease virus.


Enhancing effect of interferon pretreatment on interferon production.


Sensitivity of various H particles of poliovirus to alkaline treatment.


A sensitive plaque assay for Sendai virus in an established line of monkey kidney cells.


Typing of herpes simplex virus strains of genital and nongenital origins.


Biochemical basis for narcotic tolerance and physical dependence.


Low-renin hypertension.

Low-renin hypertension.


Tubular reabsorption of phosphate after release of complete ureteral obstruction in the rat.


The role of angiotensin in the cardiovascular and renal response to salt restriction.


Evidence for renal glomerular receptors for angiotensin II.


Phylogeny of the renal effects of angiotensin.


The adrenal cortex and the kidney.

The adrenal cortex and the kidney.


A proposed cybernetic system for sodium and potassium homeostasis: coordination of aldosterone and intrarenal physical factors.


Effects of adrenergic nervous system and catecholamines on systemic and renal hemodynamics, sodium and water excretion and renin secretion.


Vasopressin.

Vasopressin.


Parathyroid hormone and calcitonin regulation of renal function.


Estrogens and the kidney.

Estrogens and the kidney.


Estradiol receptor functions of soluble proteins from target-specific lysosomes.


The intramitochondrial distribution of the 3beta-hydroxysteroid dehydrogenase-oxosteroid isomerase. A probable redistribution artifact.


The origin of 5alpha-androstane-3alpha, 17beta-diol and its 3beta epimer in peripheral blood of immature female rats.


The epidemiologic pathology of carcinomas of the large bowel.


Intra-axonal transport and degeneration of adrenergic nerve terminals after axotomy with long and short nerve stump.


Is adenylate cyclase the dopamine receptor?


The autonomic innervation of the exocrine pancreas.


The APUD cells of the alimentary tract in health and disease.


Normal mechanisms of fat absorption and derangements induced by various gastrointestinal diseases.


Gas gangrene-on the basis of 19 observations. Advantages of combining surgery with hyperbaric oxygen therapy.


In vitro studies on the thyroid.

In vitro studies on the thyroid.


Altered stearoyl-CoA desaturase activities in Morris hepatomas 5123C and 7800.


Tumor lipids: long chain dienoic acid in sphingomyelin.


Alleged role of boric acid in detritylation of diglyceride-alpha-trityl ethers by silicic acid.


The intravenous L-alanine tolerance test as a means for investigating gluconeogenesis.


Preliminary study of the treatment of nephrolithiasis (calcium stones) with diphosphonate.


Editorial: Oestrogen receptors and breast carcinoma.


A mechanism for hyporeninemic hypoaldosteronism in chronic renal disease.


Two types of spin-labels and their interaction with phospholipid micelles and mitochondrial enzymes.


Investigation of the lysozyme macromolecule by a spin-labeling method.


Reaction of DNA with Girard's reagent P: kinetics of the reaction and resistance of the product to some nucleases.


A study of nucleus-cytoplasm interrelationships in a cell-free system with isolated rat liver cell nuclei.


Investigation of electron transport in chloroplasts and their fragments by the ESR method. Communication I. Electron transport and kinetic characteristics of the light-induced ESR signal.


An investigation of the interaction of steroids with human serum albumin by the spin-label method.


An investigation of rRNA and synthetic polyribonucleotides by the spin-label method.


Distribution of transcribable DNA sequences in mouse liver hepatoma chromatin.


Hemoglobin. Cooperativity and electronic properties.


Covalent coupling of alkaline Bacillus subtilis protease to controlled-pore silica with a new simplified coupling technique.


On the dual role of respiration.

On the dual role of respiration.


The induction of thymidine- and IUdR-resistant variants in P388 mouse lymphoma cells by x-rays, UV and mono- and bi-functional alkylating agents.


Requirements for the initiation of polyphenylalanine synthesis by recombined ribosomal subunits from yeast.


The use of different test systems with yeasts for the evaluation of chemically induced gene conversions and gene mutations.


Comparison of the genetic activity of dimethylnitrosamine, ethyl methanesulfonate, 2-acetylaminofluorene and ICR-170 in Saccharomyces cerevisiae strains D3, D4 and D5 using in vitro assays with and without metabolic activation.


Detection of chemical mutagens using a host-mediated assay (L5178Y) mutagenesis system.


The induction of micronuclei by frameshift mutagens at the time of nucleus expulsion in mouse erythroblasts.


The ultrastructure of the spherules of Emmonsia crescens studied by the technique of freeze-etching.


Editorial: Killer T cells.

Editorial: Killer T cells.


Letter: Collagenases: human and bacterial.


Poly(C) in animal viral RNAs.

Poly(C) in animal viral RNAs.


Detection of cell-dependent cytotoxic antibody to cells infected with herpes simplex virus.


Cyclic GMP stimulates lymphocyte nucleic acid synthesis.


Membrane antigens of murine leukaemia cells.


Collagenase activity in experimental hepatic fibrosis.


Autologous human B and T lymphoblastoid cell lines.


Activity of CNS depressants related to hydrophobicity.


Caffeine inhibits induction of endogenous C-type virus.


Rapid in vivo assay for murine lymphatic leukaemia viruses.


Antigenic inhibition of cell-mediated cytotoxicity against tumour cells.


Human times mouse hybrid cells segregating mouse chromosomes and isozymes.


Evolution of C-type viral genes: inheritance of exogenously acquired viral genes.


Transcription, translation and maturation of succinate dehydrogenase during cell cycle.


Octopamine receptors on Aplysia neurones mediate hyperpolarisation by increasing membrane conductance.


Binding of interferon to gangliosides.

Binding of interferon to gangliosides.


Association of polyanion resistance with tumorigenicity and other properties in BHK-21 cells.


Ultrastructural localization of herpes simplex virus antigens on rabbit corneal cells using sheep antihuman IgG antihorse ferritin hybrid antibodies.


Effects on the neonate of prednisone and azathioprine administered to the mother during pregnancy.


Serum concentrations of parathyroid hormone in infants, children, and adolescents.


Peripheral neuropathy and lead poisoning in a child with sickle-cell anemia. Case report and review of the literature.


Extending the scope of the VATER association: definition of the VATER syndrome.


Occipito-facial-cervico-thoracic-abdomino-digital dysplasia; Jarcho-Levin syndrome of vertebral anomalies. Report of six cases and review of the literature.


Possible model reactions for the nitrate reductases.


Oral contraceptive for men.

Oral contraceptive for men.


Voltage clamp studies of glutamate synapse.


Cell-mediated immunity to Epstein-Barr virus and a blocking factor in patients with infectious mononucleosis.


A rapid and simple procedure for the determination of guanosine 3',5'-monophosphate by use of the protein-binding method.


Cancer genetics: urological system. II.

Cancer genetics: urological system. II.


Appearance of alpha-fetoprotein in rat serum during induction of primary hepatoma with regard to development of histological changes in liver tissue.


Dynamics of alpha-fetoprotein production compared to alpha 2-macroglobulin during induction of primary hepatoma with 4-dimethylaminoazobenzene in rats.


Protein synthesizing activities of ribosome-like structure isolated from avian myeloblastosis virus in chicken cell-free protein synthesis.


Difference in density of nuclear pores in normal and malignant fibroblasts of Syrian hamster.


For goodness sake - let your patients sleep.


Chronic respiratory problems in neuromyopathic disorders: their nature and management.


I-cell disease (mucolipidosis II): a lysosomopathy.


Asthma: current concepts.

Asthma: current concepts.


Roadside resuscitation.

Roadside resuscitation.


Familial and acquired hyperlipoproteinemias in children and adolescents.


Soft-tissue swellings.

Soft-tissue swellings.


Relipidation of phospholipid-depleted microsomal particles with high glucose 6-phosphatase activity. Microsomal particles enriched up to 20-fold in glucose 6-phosphatase activity (as compared to crude microsomal fractions) were prepared from livers of phenobarbital-treated, normal, and diabetic rats by a method involving sucrose-density gradient centrifugation through a layer containing deoxycholate, followed by flotation of the delipidated particles in a phospholipid-detergent mixture. The flotation with phospholipid resulted in the extraction of additional protein, in a corresponding increase in specific activity, and in relipidation of the particles to their original phospholipid content. Detergents alone did not extract any additional protein. Relipidation caused a change in the properties of the microsomal membrane, as indicated by a 4-fold decrease in the K(m) for glucose 6-phosphate and mannose 6-phosphate. The maximal rate was not affected. The crude homogenate of diabetic rat liver contained more latent enzyme than that of normal rats. The diabetic rats also yielded purified microsomal particles of specific glucose 6-phosphatase activity twice that of normal and five times that of phenobarbital-treated rats, indicating that some regulatory mechanism exists for the incorporation of different amounts of the enzyme into the endoplasmic reticulum.


Degradation of pseudoviral DNA after infection of mouse cells with polyoma pseudovirions. When mouse cells are infected with [(3)H]-thymidine-labeled polyoma pseudovirions, as much as 11% of the input pseudoviral radioactivity is found in the recipient cell DNA. However, the radioactivity found in the recipient cell DNA virtually disappears when nonradioactive thymidine and deoxycytidine, or D-arabinosyl cytosine, are added to the medium. The radioactivity found in the recipient cell DNA appears to be the result of the breakdown of pseudoviral DNA to precursors of DNA and the utilization of these precursors for the synthesis of cell DNA.


Aldosterone-induced increase in protein phosphatase activity of toad bladder. A study has been carried out of the effect of aldosterone on the endogenous phosphorylation and dephosphorylation of membrane-bound and of soluble proteins from toad bladder. Membrane-bound protein D (apparent molecular weight, 49,000), a protein which may possibly be involved in the regulation of sodium transport across the mucosal epithelium of toad bladder, contained a substantial fraction of the radioactive phosphate incorporated into membrane proteins; moreover, it was the only protein to appear consistently in autoradiographs of polyacrylamide gels of phosphorylated membrane proteins. Pretreatment of toad bladder slices with aldosterone caused an increase in the endogenous dephosphorylation of membrane-bound protein D. A half-maximal increase in this dephosphorylation occurred at an aldosterone concentration of 20-40 nM. The increase in protein D phosphatase activity induced by aldosterone was prevented by inhibitors of RNA and protein synthesis as well as by spironolactone, a specific antagonist of aldosterone. The mineralocorticoid, 9alpha-fluorohydrocortisone, also increased protein D phosphatase activity, but testosterone did not. Aldosterone also increased the removal of [(32)P]phosphate from protein D in the cell sap. In contrast to the increase in protein D phosphatase activity, aldosterone had little effect on the phosphorylation of protein D by endogenous protein D kinase. In some experiments, effects of aldosterone and of cAMP, qualitatively similar to those found with protein D, were also observed on the phosphorylation and dephosphorylation of a protein with an apparent molecular weight of 37,000, in both the microsomal and cell sap fractions. No consistent effect of preincubation with aldosterone or of cAMP was observed on any membrane-bound or cell sap protein other than protein D and the 37,000 dalton protein.


Synthesis of viral DNA in the cytoplasm of duck embryo fibroblasts and in enucleated cells after infection by avian sarcoma virus. TWO LINES OF EVIDENCE INDICATE THAT SYNTHESIS OF VIRAL DNA OCCURS IN THE CYTOPLASM OF DUCK EMBRYO FIBROBLASTS INFECTED WITH AVIAN SARCOMA VIRUS: (i) viral DNA is detected first in the cytoplasmic fraction of infected cells and subsequently in the nuclear fraction; and (ii) viral DNA is synthesized at a normal rate in cells infected after enucleation with cytochalasin B. The presence of viral DNA in the cytoplasmic fraction is not a consequence of leakage of newly synthesized viral DNA from the nucleus, since it remains in nuclear fractions late after infection when integration of viral DNA into the host genome is inhibited by ethidium bromide.


Enhancement of dopamine-stimulated adenylate cyclase activity in rat caudate after lesions in substantia nigra: evidence for denervation supersensitivity. Unilateral radiofrequency lesions or chemical lesions with 6-hydroxydopamine were produced in the substantia nigra of rat brain in order to destroy dopaminergic innervations to caudate nucleus and thereby to produce functional denervation supersensitivity. Both types of lesions resulted in enhanced stimulation of caudate adenylate cyclase (EC 4.6.1.1) activity by dopamine at all dopamine concentrations tested, with more marked enhancement at the lower concentrations. Response to another dopamine agonist, 1-(3,4-dihydroxybenzyl)-4-(20pyrimidinyl) piperazine (S584) was also enhanced. 6-Hydroxydopamine lesions resulted in selective enhancement of the dopamine-stimulated component of adenylate cyclase, whereas radiofrequency lesions resulted also in a marked decrease in basal activity. It is postulated that the basal activity of caudate represents primarily an adenylate cyclase distinct from that stimulated by dopamine and destroyed only by the less selective radiofrequency lesion. The enhancement of dopamine-sensitive adenylate cyclase after lesions serves as indirect evidence for a significant role of this system in the transmitter function of dopamine and indicates, furthermore, that it is directly involved in dopamine receptor supersensitivity in vivo produced by denervation.


Receptors from glucocorticoid-sensitive lymphoma cells and two clases of insensitive clones: physical and DNA-binding properties. Mouse lymphoma tissue culture cells (S49.1A) are normally killed by dexamethasone, a synthetic glucocorticoid hormone. Dexamethasone-resistant clones have been selected from this line, some of which retain the ability to specifically bind dexamethasone. Addition of [(3)H]dexamethasone to cultures, followed by cell fractionation, reveals that the nuclear transfer of hormone-receptor complexes in some of these variant clones is deficient (nt(-)), while others show increased nuclear transfer (nt(i)) relative to the parental line. Two independently selected members of each class have been studied here, in an effort to elucidate the molecular determinants involved in the receptor-nucleus interaction in vivo. The labeled receptors in cell-free extracts bind to DNA-cellulose, but only after previous incubation of the extract at 20 degrees , similar to the treatment required for cell-free interaction of receptors with nuclei. More importantly, the apparent DNA-binding affinity of the nt(-) receptors is lower than the wild type, whereas the nt(i) receptors bind DNA with an affinity higher than the parental molecules. The parallelism of nuclear and DNA binding, together with the observations that the receptors from the variants have sedimentation properties different from the wild-type cells, lead us to conclude that (i) these variants may contain altered receptor molecules and (ii) DNA is probably the primary nuclear binding site for steroid receptors in vivo.


Identification of methylated nucleosides in messenger RNA from Novikoff hepatoma cells. The poly(A) tract found in eukaryotic mRNA was used to study methylation in mRNA obtained from Novikoff hepatoma cells. Methyl labeling of RNA was achieved with L-[methyl-(3)H]methionine under conditions that suppress radioactive incorporation into the purine ring. RNA that contains a poly(A) segment was obtained from polysomal RNA by chromatography on oligo(dT)-cellulose. Sucrose density gradient centrifugation of this RNA revealed a pattern expected for mRNA. The composition of the methyl-labeled nucleosides in the RNA was analyzed after complete enzymatic degradation to nucleosides. By use of DEAE-cellulose (borate) chromatography, which separates 2'-O-methylnucleosides from normal and base-methylated nucleosides, about 50% of the radioactivity was recovered in the 2'-O-methylnucleoside fraction and 50% in the base-methylnucleoside fraction. High-speed liquid chromatography (Aminex A-5) of the 2'-O-methylnucleoside fraction produced four peaks coincident with the four 2'-O-methylnucleoside standards. Analysis of the base-methylnucleoside fraction revealed a unique pattern. While ribosomal RNA and tRNA possessed complex base-methylnucleoside patterns, the distribution in mRNA was quite simple, consisting predominantly of N(6)-methyladenosine. These results demonstrate a unique distribution of methylated nucleosides in mRNA. By analogy to ribosomal RNA synthesis, the presence of methylnucleosides in mRNA may reflect a cellular mechanism for the selective processing of certain mRNA sequences.


Induction of type-C RNA virus by cycloheximide: increased expression of virus-specific RNA. Mouse cells contain the genetic information for multiple endogenous type-C RNA viruses. The mechanisms by which the cell controls expression of these naturally integrated viruses are not yet known. Recently, chemicals that inhibit protein synthesis have been shown to induce a specific type-C virus at high frequency from BALB/c mouse embryo cells. In the present studies, virus activation in response to a representative translational inhibitor, cycloheximide, is demonstrated to be transient, with virus release primarily occurring within the first 12-24 hr following drug exposure. Analysis of virus-specific RNA in cells by molecular hybridization revealed an absolute increase in viral RNA concentration in cycloheximide-treated cells. This was blocked by simultaneous exposure of the cells to actinomycin D. Further, inhibition of RNA synthesis during but not subsequent to cycloheximide exposure prevented virus activation. These findings show that virus induction by cycloheximide requires de novo RNA synthesis during but not after drug exposure and suggest that the required RNA species may be that of the virus itself. The present results are consistent with the hypothesis that translational inhibitors prevent synthesis of a labile protein whose normal action is to inhibit viral RNA transcription or to cause degradation of viral RNA.


The glycine synaptic receptor: evidence that strychnine binding is associated with the ionic conductance mechanism. The ability of a series of anions to inhibit [(3)H]strychnine binding to spinal cord synaptic membranes correlates closely with their neurophysiologic capacity to reverse inhibitory postsynaptic potentials in the mammalian spinal cord. Seven neurophysiologically active anions are also effective inhibitors of [(3)H]strychnine binding with mean effective doses ranging from 160 to 620 mM. Seven other anions that are ineffective neurophysiologically also fail to alter strychnine binding. Chloride inhibits strychnine binding in a noncompetitive fashion. Hill plots of the displacement of [(3)H]strychnine by chloride give coefficients of 2.3-2.7. The inhibition of strychnine binding by these anions suggests that strychnine binding is closely associated with the ionic conductance mechanism for chloride in the glycine receptor.


Differences between laboratory strains of Epstein-Barr virus based on immortalization, abortive infection, and interference. Biologic activities of extracellular Epstein-Barr virus (EB virus) from two laboratory strains, namely, P(3)J-HR-1 (P-H) from Burkitt lymphoma and B95-8 (B95) from infectious mononucleosis, were compared. Virus stocks from both sources contained approximately the same number of virions. Virus from the P-H line induced "early antigen" in six nonproducer EB virus genome carrier cell lines; virus from B95 did not induce "early antigen." Extracellular virus from B95 regularly caused lymphocytes from human umbilical cords to form continuous lines (immortalization); P-H virus did not cause primary cultures of human lymphocytes to grow continuously. B95 virus stimulated DNA synthesis as determined by rate of incorporation of [(3)H]thymidine into acid-insoluble material; P-H virus did not stimulate DNA synthesis. Pretreatment of lymphocytes with undiluted P-H virus inhibited immortalization and stimulation of DNA synthesis by B95 virus. The inhibitory properties of the P-H virus were sedimented at 100,000 x g and inactivated by heat and UV irradiation; interference by the P-H virus was neutralized by human serum with antibody to EB virus and not by antibody-negative human serum. The hypothesis most consistent with these results is that the P-H virus is defective in gene(s) needed for initiation of immortalization. We speculate that the absence of this gene allows early antigen to be expressed upon super-infection of nonproducer cell lines. The availability of two laboratory strains of EB virus which differ in biologic behavior provides starting material for analysis of the mechanism of lymphocyte immortalization by EB virus and of virus structural differences which affect immortalization.


Carbohydrate composition of the membrane glycoprotein of vesicular stomatitis virus grown in four mammalian cell lines. The carbohydrate composition of the membrane glycoprotein of vesicular stomatitis virus has been determined for virus grown in four different mammalian cell lines. The glycoprotein contains mannose, galactose, N-acetylglucosamine, and neuraminic acid as the major carbohydrate components, whereas N-acetyl-galactosamine and fucose are present in lesser amounts. The glycoprotein contains approximately 9-10% carbohydrate regardless of the host cell in which it is synthesized. Small quantitative differences are evident in the composition of the component sugars of the glycoprotein when the virus is grown in different host cells, and the glycoprotein of virus grown in a mouse fibroblast line (L cells) lacks fucose. The major oligosaccharide moieties of the virus glycoprotein from all cells are approximately the same size (3000-3400 daltons). The data presented here, in conjunction with previous data, indicate that the viral glycoprotein contains two major oligosaccharide constituents regardless of the host cell in which it is synthesized.


Guanosine 3':5'-monophosphate-dependent protein kinases in mammalian tissues. The mammalian protein kinase activity stimulated preferentially by low concentrations of guanosine 3':5'-monophosphate (cyclic GMP), but not by adenosine 3':5'-monophosphate (cyclic AMP), was readily assayed in a modified incubation system that contained a neutral phosphate buffer, protein kinase modulator, and arginine-rich histone. Cyclic GMP-dependent protein kinase activity assayed under these conditions was about two to three orders of magnitude higher than that previously detected. The enzyme activity occurred in all guinea pig and rat tissues (lung, heart, aorta, brain, liver, ileum, adipose, and pancreatic islets) examined. The activity can be separated from the cyclic AMP-dependent protein kinase activity, also present in the same tissues, by means of either Sephadex G-200 gel filtration or ammonium sulfate fractionation. The cyclic GMP-dependent enzyme preparations had K(a) values for cyclic GMP ranging from 0.03 to 0.12 muM, compared to the K(a) values for cyclic AMP ranging from 0.6 to 3.8 muM. The presence of phosphate and protein kinase modulator was essential for maximal cyclic GMP-dependent enzyme activity. The occurrence of high levels of cyclic GMP-dependent protein kinase activity in mammalian tissues clearly suggests that it may serve as a "target" enzyme for cyclic GMP, mediating many biological effects of this cyclic nucleotide.


Initiation of oncogenic transformation of mouse lymphocytes in vitro by Abelson leukemia virus. While C-type RNA viruses are known to induce leukemias and lymphomas, oncogenic transformation of lymphoid cells by them in vitro has not been reported. In this study, splenocytes from female BALB/c mice were infected in vitro with Abelson virus, a C-type RNA virus that induces nonthymic lymphomas and plasmacytomas in mice. The cells were transplanted into recipients of different karyotype, either male BALB/c mice or hybrid BALB/c x AL/N (CALF1) mice, which bear the Rb(5.19)1Wh translocation. Transplants of eight of the resulting tumors (one plasmacytoma and seven lymphomas) contained cells of donor BALB/c karyotype, indicating that transformation of splenocytes occurred in vitro.


Stimulation of synthesis of free chondroitin sulfate chains by beta-D-xylosides in cultured cells. Previous studies have shown that D-xylose partially overcomes the puromycin inhibition of chondroitin sulfate synthesis in cultured chick embryo chondrocytes. Likewise, D-xylose stimulates chondroitin sulfate synthesis by limb bud mesenchyme cells previously treated with BrdU or limb bud cartilage cells treated with puromycin. The studies reported here show that p-nitrophenyl-beta-D-xylopyranoside and 4-methyl-umbelliferyl-beta-D-xylopyranoside cause a much greater stimulation than does D-xylose and are active at much lower concentrations. In contrast to D-xylose, the xylosides strikingly stimulate chondroitin sulfate synthesis in predifferentiated mesenchyme cells. The xylosides stimulate synthesis of chondroitin sulfate by rat glial cell tumor cells (RC-6), a mouse neuroblastoma (C1300, NB41A), and two strains of cultured rat hepatoma cells (HTC, H(4)). These results indicate that certain types of nonconnective tissue cells contain the enzymic machinery for synthesis of chondroitin sulfate which is normally not utilized because of limited synthesis of core protein and/or xylosyltransferase. The beta-xylosides may be used as a probe of the capacity of various cell types to synthesize sulfated glycosaminoglycans.


Correlation between thermal death and membrane fluidity in Bacillus stearothermophilus. Paramagnetic resonance spectra of spin labels partitioned into spheroplast membranes of Bacillus stearothermophilus indicate lateral lipid phase separations. Cells adjust their lipid composition in response to temperature changes so that the same change of state in membrane phospholipids is achieved at the respective growth temperature. A temperature-sensitive mutant that fails to change its lipid composition above a certain temperature can survive only up to the higher temperature boundary for lateral phase separation. These data are interpreted to indicate that the maximal and minimal growth temperatures of thermophiles are regulated by the onset and conclusion of phase separations of the particular lipid composition they synthesize. It is suggested that isolated lipid domains are required for functional membrane assembly.


Chromosome assignment of the T-antigen gene of simian virus 40 in African green monkey cells transformed by adeno 7-SV40 hybrid. Somatic cell hybrids between mouse cells deficient in thymidine kinase [ATP:thymidine 5'-phosphotransferase (EC 2.7.1.75)] and two different monkey cell lines transformed by an adeno 7-SV40 hybrid have been produced using both a semiselective and a double selective procedure. Concordant segregation of the expression of SV40 T antigen with a specific monkey chromosome has been observed in all the mouse-monkey hybrid clones examined. Subcloning of three SV40 T antigen positive hybrid clones resulted in their segregation into SV40 T antigen-positive and negative subclones. Positive correlation between the SV40 T antigen and the same monkey chromosome has been observed in all the subclones examined.


Alterations in glucose metabolism in chick-embryo cells transformed by Rous sarcoma virus: intracellular levels of glycolytic intermediates. Chick-embryo cells, transformed with Rous sarcoma virus, show enhanced rates of sugar transport and glycolysis. Determination of intracellular concentrations of glycolytic intermediates suggests that the enhanced glycolytic flux is due to increased activities of hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1), phosphofructokinase, (ATP:D-fructose-1-phosphate 6-phosphotransferase, EC 2.7.1.56), and pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40), and not directly to the increased glucose transport. This conclusion is supported by the finding that the intracellular concentration of free glucose is decreased, rather than increased, in the transformed cells. The present observations suggest that the increased glycolytic flux is related to an increased rate of phosphorylation of glucose, and that hexokinase in the transformed cells is at least partly released from its normal control mechanism involving feedback inhibition by glucose-6-P.


Myosin is a component of the cell surface of cultured cells. Antisera to myosin from mouse L929 cells, mouse uterus, and rabbit skeletal muscle have been prepared in goats. Each antiserum shows specific reaction by immunodiffusion only to the myosin against which it was prepared. Antiserum against L cell myosin agglutinates L929 cells and shows surface localization in unfixed cells by indirect immunofluorescence. This reaction is prevented by immunoabsorption with L cell myosin, but not by absorption with mouse uterine or rabbit skeletal muscle myosins. Elution of the antibody from L cell myosin antiserum that absorbs to fixed L cells yields antibody reactive to L cell myosin in immunodiffusion. At the ultrastructural level, surface localization is also evident with a peroxidase bridge immunocytologic method as a uniform distribution of surface label. Antiserum against L cell myosin also shows localization on the surface of other cells of rodent origin (3T3-4, NRK, MNRK, KNRK, and MEF) and HeLa cells, but not with some other cells of human origin (ALL and WI-38). The reactivity with antibody of the plasma membrane myosin is unaffected by trypsin treatment or fixation with 0.5-2.0% formalin. These results strongly suggest that myosin in cultured nonmuscle cells is a component of the plasma membrane, a finding of possible significance in studying the mechanisms regulating the motility, morphology, and growth of these cells.


Evidence for the involvement of sulfhydryl oxidation in the regulation of fat cell hexose transport by insulin. Previous studies have shown that the oxidants Cu(++), H(2)O(2), and diamide mimic the stimulatory effect of insulin on 3-O-methylglucose transport in isolated fat cells. The present experiments were designed to determine whether sulfhydryl oxidation plays a key role in the activation of the glucose transport system. It was found that reductants such as dithiothreitol inhibited 3-O-methylglucose transport rates and that this effect was reversible when cells were washed free of reducing agent. Treatment of cells with 1 mM N-ethylmalcimide for 5 min completely blocked the actions of insulin and oxidants on hexose transport without affecting control transport system activity. Under these conditions, binding of (125)I-labeled insulin to fat cell surface receptors was inhibited by only about 50%. Addition of insulin or oxidants to fat cells for 10 min before addition of N-ethylmaleimide completely prevented the inhibitory effect of N-ethylmaleimide on the activated transport system. This protective effect on transport rates appears to reside at a site that is altered by insulin subsequent to hormone-receptor interaction, since prior treatment of fat cells with insulin did not prevent the partial inhibitory effect of N-ethylmaleimide on insulin receptors. Furthermore, treatment of cells with N-ethylmaleimide after incubation with insulin prevented the elevated transport rates from returning to control levels when either the cells were washed free of hormone or insulin binding to its receptors was disrupted by trypsin digestion. However, transport rates in these cells treated with N-ethylmaleimide remained sensitive to cytochalasin B, phlorizin, and reductants. These data suggest that a component of the glucose transport system in isolated fat cells must be maintained in its disulfide state for expression of transport activity. Further, the results are consistent with the concept that the binding of insulin to cell surface receptors triggers sulfhydryl oxidation in this component, which prevents its reaction with N-ethylmaleimide.


Viral DNA in transformed cells. III. The amounts of different regions of the SV40 genome present in a line of transformed mouse cells. (32)P-Labeled SV40 DNA was treated sequentially with restricting endonucleases EcoRI and Hpa I, and the resulting four fragments of DNA were separated by gel electrophoresis. The kinetics of renaturation of each of the fragments and of complete SV40 DNA were measured in the presence of DNA extracted from the SVT2 line of SV40-transformed mouse cells. It was found that these cells contain about six copies of a segment of DNA which includes the early region of the SV40 genome, and about one copy of the late viral sequences. To map the region of the viral genome which is transcribed in SVT2 cells, separated strands of each of the four fragments were prepared and hybridized to total transformed cell RNA. Part of the E strands of the two DNA fragments (A and C) which span the early region of the SV40 genome were found to enter the hybrid.


Further comparison of predicted and experimentally determined structure of adenylate kinase. An analysis is made of various predictive methods used to locate alpha-helices and beta-sheets in proteins. The analysis is based on attempts to locate the alpha-helices and beta-sheets in adenylate kinase (ATP:AMP phosphotransferase EC 2.7.4.3) from the sequence without prior knowledge of the x-ray findings. Specification of the beta-sheet breaking and alpha-helix breaking tripeptides, a method independent of the others combined with the best of the other methods would substantially reduce the prediction of nonexistent beta-sheets and to a lesser extent would aid in locating alpha-helices.


Vitamin D: concerning the relationship between molecular topology and biological function. Structure-function relationships for vitamin D, its metabolites, and analogs are discussed with particular emphasis on the A-ring conformation. It is emphasized that the A-ring of these seco-steroids consists of a pair of rapidly equilibrating chair conformers. As a consequence, different chair conformations produce different orientations of substituent groups in the A-ring. It is proposed that the 1alpha-hydroxyl of 1alpha,25-dihydroxyvitamin D(3) or its geometric equivalent in analogs must occupy the equatorial, as opposed to the axial, orientation for optimization of biological activity. This proposal is discussed in relation to existing published data on structure-function relationships and the steroid hormone model of action for the biologically active form of vitamin D. This three-dimensional topological model suggests the synthesis of other vitamin D analogs.


Reciprocal inhibition of mouse leukemia virus infection by Fv-1 allele cell extracts. Soluble extracts of mouse cells with Fv-1(n) or Fv-1(b) gene alleles specifically and reciprocally inhibit infection of B- or N-tropic mouse leukemia viruses in permissive cell cultures. NB-tropic virus infection was not inhibited by either cell extract. Extracts from Fv-1(-) cells did not inhibit infection by the three virus host-range types, but N- or B-tropic virus infection of Fv-1(-) cells was inhibited by extracts of the nonpermissive cells, and Fv-1(nb) cell extracts inhibited both viruses. The maximum degree of inhibition was 50-80% as determined by immunofluorescent or plaque assays, with extracts containing up to 500 mug/ml of nonpermissive cell protein. The inhibitor(s) is relatively unstable since activity is lost after 2 hr at 37 degrees or 30 min at 56 degrees . The inhibitor(s) was most effective if added 2 hr before or within 2 hr after infection, did not react with the virus directly, inhibit virus attachment, or inhibit the normal cell functions tested. These results indicate that nonpermissive mouse cells contain a product, possibly determined by the Fv-1 gene, which inhibits some early postpenetration event(s) in leukemia virus infection.


Evidence for crossing-over between avian tumor viruses based on analysis of viral RNAs. The RNAs of several avian tumor virus recombinants that had inherited their focus-forming ability from a sarcoma virus and their host range marker from a leukosis virus were investigated. Electrophoretic analyses showed that the cloned sarcoma virus recombinants contained only size class a RNA, although they had acquired a marker that resided on class b RNA in the leukosis virus parent. Class a RNA of different recombinant clones, derived from the same pair of parental viruses and selected for the same biological markers, differed slightly in electrophoretic mobility from each other and from the parental sarcoma virus. They were also found to have different fingerprints of RNase T1-resistant oligonucleotides. The average complexity of the 60-70S RNA prepared from Prague Rous sarcoma virus of subgroup B was estimated to be 3.5 x 10(6) daltons from the size of 20 RNase T1-resistant oligonucleotides, which represented 3.9% of the RNA and that of a recombinant to be 3.3 x 10(6) daltons from 23 oligonucleotides, which represented 4.7% of the RNA. This result suggests that the genome of wild-type and of recombinant RNA tumor viruses is polyploid. The sum of these observations led us to propose that recombination among avian tumor viruses occurred by crossing-over between homologous pieces of nucleic acid.


Biological activity of a growth factor for ovarian cells. The biological activity of a protein growth factor is described. This factor was isolated from bovine pituitary tissue, and its activity was tested on cells of rat ovarian origin. Activity was assayed as growth-promoting potential measured by cell counts and is concentrationdependent. Similar growth stimulation was not produced by several cyclic nucleotides tested, neither was there crossreactivity between this growth factor and a chemically similar one produced by rat liver cells.


Changing the actions of neuroactive drugs by changing brain protein synthesis. Diminution of cerebral protein synthesis diminished the cerebral responses of mice to some neuroactive drugs, while an increase in synthesis increased the responses. Protein synthesis in whole brains (tested in vitro) was diminished by giving living mice different inhibitors by different routes. The inhibitors tested (chloramphenicol, cycloheximide, and puromycin) diminished the behavioral responses of the mice to levodopa without affecting either its cerebral uptake or its conversion to dopamine. A diminution of the reactions of dopaminergic receptors was suggested by the diminished responses to the dopaminergic drug, apomorphine, while participation of cholinergic ones was suggested by experiments with oxotremorine. Proof that receptors had been specifically involved was secured on homogenized caudate nuclei from chloramphenicol-treated mice, in which the dopamine-activated production of cyclic AMP was markedly diminished. A stimulator of cerebral protein synthesis, the artificial double-stranded RNA, poly(I).poly(C), increased the behavioral responses to these three drugs while it increased the dopamine-activated production of cyclic AMP. Since all these experimental increases or decreases in the responses to drugs required the lapse of only a few hours, proteins with rapid turnover rates must be critical in the activation of several kinds of cerebral receptors.


The pancreatic beta-cell recognition of insulin secretagogues: does cyclic AMP mediate the effect of glucose? Insulin release and the content of cAMP were studied in microdissected pancreatic islets of noninbred ob/ob (obese) mice. In the absence of 3-isobutyl-1-methylxanthine, a phosphodiesterase inhibitor, 20 mM glucose had no effect on cAMP save a very small initial rise detectable by a freeze-stop perifusion technique only. However, combined with this methylxanthine, 20 mM glucose produced significant increases of cAMP both in perifused islets and in islets conventionally incubated in closed vials. Glucose shared this capacity to raise the cAMP level with D-glyceraldehyde and 1,3-dihydroxyacetone. Isobutylmethylxanthine (0.05-1.0 mM) or 5 mug/ml of cholera toxin, an activator of adenylate cyclase, also increased the islet cAMP level; the effects of the methylxanthine, whether or not combined with cholera toxin, were potentiated by glucose. Isobutylmethylxanthine (0.05-1.0 mM) or 5 mug/ml of cholera toxin potentiated insulin release in response to 20 mM glucose. However, only 0.5-1.0 mM isobutylmethylxanthine stimulated insulin release in the presence of 3 mM glucose, whereas 0.05-0.1 mM isobutylmethylxanthine or 5 mug/ml of cholera toxin had no effect on secretion at the low glucose concentration. These discrepancies between cAMP-promoting and insulin-releasing activities suggest that glucose does not initiate insulin release by activating the beta-cell adenylate cyclase. By being metabolized in the beta-cells, glucose may both create a release-initiating signal not identical with cAMP and enhance cAMP formation, leading to potentiation of the effect of the initiator signal.


Purification and separation of pyridine nucleotide-linked dehydrogenases by affinity chromatography techniques. A number of different dehydrogenases have been shown to bind to Sepharose-bound N(6)-(6-aminohexyl)-AMP. These dehydrogenases can be specifically eluted by binary adducts of NAD(+) or with cofactor gradients. In such manner pure enzymes can be obtained from crude extracts, as demonstrated in the purification on a preparative scale of lactate dehydrogenase from dogfish muscle. The data presented indicate the usefulness of general ligands as affinity agents. The techniques are particularly adaptable for the isolation of human mutant enzymes in blood or in the purification and concentration of enzymes present at low levels in fluids or tissues, as shown in the extensive purification of serum lactate dehydrogenase and glucose 6-phosphate dehydrogenase from hemolysate. lsoenzymes with different affinities for co-enzymes can be separated by affinity techniques. Application of affinity techniques may lead to the separation of isoenzymes or mutant enzymes that are not separable by electrophoretic methods.


The contribution of subunits of thyroid stimulating hormone to the binding and biological activity of thyrotropin. The binding of bovine TSH (thyroid stimulating hormone), LH (luteinizing hormone), and their subunits to the TSH receptor of beef thyroid membranes was compared to stimulation by these agents of adenylate cyclase [ATP pyrophosphate-lyase(cyelizing), EC 4.6.1.1] in the same membranes, glucose oxidation in dog thyroid slices, and the secretory process in mouse thyroids in vitro (colloid droplet formation) and in vivo (hormone release). The beta-subunits of TSH and LH can bind to the TSH receptor and can activate thyroid function in vitro. In contrast, the alpha-subunit of TSH binds negligibly to the TSH receptor and has very low potency for stimulation of thyroid function (except for colloid droplet formation). Neither binding nor the biological activity of the beta-subunits can be accounted for by TSH contamination, whereas this cannot be ruled out for alpha-TSH. LH binds to the TSH receptor even better than the beta-subunit of TSH but the increased binding does not result in a corresponding activation of thyroid function. Neither alpha- nor beta-TSH alone can induce more than 4-8% of the response to intact TSH in any of the investigated parameters. It is proposed that the beta-subunit has within its structure the primary determinants which are necessary to stimulate biological activity, whereas the alpha-subunit imposes conformational changes on the beta-subunit which in intact TSH promote binding and biological activity commensurately but in LH promote only binding.


Reversibility of the pyrophosphoryl transfer from ATP to GTP by Escherichia coli stringent factor. The stringent factor-catalyzed, ribosome-dependent synthesis of guanosine polyphosphates is found to be reversible. The reverse reaction specifically requires 5'-AMP as the pyrophosphoryl acceptor, and guanosine 5'-triphosphate-3'-diphosphate is preferentially utilized as the pyrophosphoryl donor. The primary products of the reaction are GTP and ATP. The reverse reaction is strongly inhibited by the antibiotics thiostrepton and tetracycline, and by ATP and beta-gamma-methylene-adenosine-triphosphate, but not by ADP, GTP, and GDP. The reverse reaction occurs under conditions for nonribosomal synthesis. The overall reaction for stringent factor-catalyzed guanosine polyphosphate formation may thus be formulated: (p)pp5'G + ppp5'A right harpoon over left harpoon (p)pp5'G3'pp + p5'A.


Distribution and fate of synthetic lipid vesicles in the mouse: a combined radionuclide and spin label study. Single compartmental spherules of various lipid constituents (vesicles), enclosing (99m)TcO(4) (-) as a radioactive marker, were injected intravenously into C(3)H mice, and the distribution of radioactivity was studied. About 25% of the administered radioactivity was present in the liver 5 min and 30 min after the injection of vesicles composed of phosphatidylcholine and gangliosides, which were sonicated for 5 min (standard preparation). About 10-20% of the radioactivity remained in the circulation. By use of a nonradioactive spin label (tempocholine) enclosed within vesicles, intact vesicles were demonstrated in the circulation for 46 min after intravenous injection. The distribution of radioactivity from (99m)TcO(4) (-) inside vesicles is very different from that of free (99m)TcO(4) (-) or of (99m)Tc sulfur colloid. Increase in the length of sonication or incorporation of cholesterol into the wall of the vesicles enhanced hepatic levels and reduced blood levels of radioactivity. These same manipulations also slowed the rate of transfer of (99m)TcO(4) (-) out of vesicles in dialysis experiments in vitro. Addition of phosphatidic acid, phosphatidylethanolamine, or phosphatidylserine to the standard constituents did not greatly alter the distribution of radioactivity in vivo but did increase the number and type of active coupling sites on the outside of the vesicle. The results indicate that vesicles might be valuable as carriers of diagnostic or therapeutic agents.


Sequence arrangements in clonal isolates of polyoma defective DNA. Five clonal isolates of purified polyoma defective DNA [Fried, M. (1974) J. Virol. 13, 939-946] have been examined by electron microscopy. Four isolates (D-92, D-74, D-50, and D-47) are largely homogeneous in sequence, whereas, the fifth isolate (D-80) is somewhat heterogeneous.Polyoma nondefective DNA is cleaved in a unique region of the genome by the EcoR(I) endonuclease. Hybridization of the resulting linear molecules with randomly nicked defective DNA reveals distinguishable types of heteroduplex structures for each of the different defective DNAs. Although the defective DNAs are shorter than polyoma nondefective DNA, the heteroduplex experiments demonstrate that they are not simply deletion mutants containing only a portion of the viral genome. Three isolates (D-92, D-50, and D-47) contain regions of homology to polyoma DNA covalently linked to non-homologous regions. One isolate (D-74) contained no regions of detectable homology to polyoma DNA. Another isolate (D-80) contained a large proportion of molecules with duplicated-inverted regions. Some of these isolates of defective DNA may contain specific host sequences at the site(s) of integration of the polyoma genome during the lytic cycle in mouse cells. A process we term "abortive replication" may explain the formation of different types of defective DNAs.


AKR murine leukemia virus genome: frequency of sequences in DNA of high-, low-, and non-virus-yielding mouse strains. Studies with a single-stranded DNA probe complementary to the RNA of mouse-tropic AKR murine leukemia virus indicate that the complete genome of the AKR-type murine leukemia virus is present in the DNA of high- and low-virus-yielding mouse strains, while DNA of non-virus-yielding strains contains only a part of the genome. Furthermore, in those strains where the genome is complete, two populations of virus-specific DNA sequences can be identified (more abundant and less abundant species) according to their rate of association with the probe. Low-virus-yielding mouse strains contain fewer copies of the less abundant species and, consequently, fewer complete viral genomes than do high-virus-yielding strains. Thus, in the ten strains tested, there is a good correlation between completeness of the genome of AKR-type murine leukemia virus in cellular DNA and the capacity of the cells to release infectious AKR-type murine leukemia virus. Moreover, the number of complete viral genomes correlates with the frequency of infectious virus production by virus-positive strains. DNA from wild Mus musculus also contained viral sequences, the sample tested showing reassociation kinetics identical to the non-virus-producing strains.


The nucleotide sequence complexity of avian tumor virus RNA. The nucleotide sequence complexity of 60-70S RNA of Rous sarcoma virus was determined from the molar yields of 11 pure oligonucleotides of known chain length, obtained from [(32)P]RNA of Rous sarcoma virus by T1 RNase digestion and two-dimensional polyacrylamide gel electrophoresis. We calculate an apparent chain length of about 9800 nucleotides, corresponding to a molecular weight of 3.4 x 10(6). Assuming the molecular weight of 60-70S RNA of Rous sarcoma virus to be about 10(7), our data suggest that the virus genome consists of identical, or very similar, nucleotide sequences repeated three to four times.


Activation of protein kinase by physiological concentrations of cyclic AMP. When determined under the usual conditions of an excess of ligand over protein, the concentration of cyclic AMP necessary to activate pure preparations of cyclic AMP-dependent protein kinase (EC 2.7.1.37; ATP:-protein protein phosphotransferase) half-maximally is in the range of 0.2-0.3 muM when casein or glycogen synthetase is used as the substrate, i.e., essentially the same as the concentration of the nucleotide that is found in resting skeletal muscle. The apparent dissociation constant for cyclic AMP bound to the protein kinase is also about 0.2-0.3 muM when measured under similar conditions. The concentration of the protein kinase in muscle is relatively high (0.23 muM), however, and under these conditions the apparent activation constant of the enzyme for cyclic AMP is raised so that an increase in cyclic AMP levels in the tissue would cause a concomitant increase in protein kinase activity over a wide range of nucleotide concentration. As a result, it is unnecessary to invoke compartmentalization of cyclic AMP to explain how it can control protein kinase activity in vivo. Another factor that may increase the effectiveness of changes in cyclic AMP concentration is the heat-stable protein inhibitor of protein kinase that may function to inhibit the activity of nearly all the protein kinase catalytic subunit dissociated by basal concentrations of cyclic AMP. Finally, the near equity between the concentration of cyclic AMP binding sites and the ligand itself provides a potential mechanism whereby agents can affect the total cyclic AMP content without directly affecting adenylate cyclase, cyclic AMP phosphodiesterase, or cyclic AMP transport.


Establishment of a clone of mouse hypothalamic neurosecretory cells synthesizing neurophysin and vasopressin. Hypothalamic cells taken from 14-day-old mouse embryos were cultured for 6 days and transformed with simian virus 40. After cloning, a homogeneous cell population was obtained. Its morphological, Ultrastructural, biochemical, and immunochemical properties were studied. These cells possess ultrastructural features of primitive neurosecretory cells. They synthesize (35)S-labeled protein components that have the molecular weight and isoelectric focusing behavior of, and display the same immunoreactivity as, neurophysin. In addition, a (35)S-labeled peptidic fraction with a molecular weight close to 1000 is synthesized and is radioimmunologically indistinguishable from vasopressin. Immunochemical staining shows that both neurophysin and vasopressin are localized in the cytoplasm. These observations strongly suggest that a clone of mouse hypothalamic neurosecretory cells has been obtained with the synthesizing capacities of secretory neurons of the magnocellular hypothalamic nuclei.


Collagenase production by endotoxin-activated macrophages. Peritoneal exudate macrophages, when exposed to bacterial lipopolysaccharide in culture, were found to produce collagenase (EC 3.4.24.3). This enzyme was not detected in extracts of the macrophages or in media from nonstimulated macrophage cultures. Lipidcontaining fractions of the lipopolysaccharide, including a glycolipid from the rough mutant of Salmonella minnesota (R595) and lipid A, were potent stimulators of collagenase production. The lipid-free polysaccharide fraction had no effect. Cycloheximide prevented the production of collagenase by endotoxin-treated macrophages, suggesting that it was newly synthesized.


The primary structure of high density apolipoprotein-glutamine-I. The major protein constituent of human plasma high density lipoproteins has been isolated and its complete amino-acid sequence determined. The protein, designated apolipoprotein-glutamine-I by the presence of carboxyl-terminal glutamine, is a single polypeptide chain of 245 amino-acid residues, including three residues of methionine. The protein is devoid of cysteine, cystine, and isoleucine. Cleavage of apolipoprotein-glutamine-I with cyanogen bromide yields four fragments with 94, 90, 36, and 25 amino acids. The amino-acid sequence of each fragment was determined by conventional methods, with proteolytic digestion with trypsin, chymotrypsin, and thermolysin. The alignment of the cyanogen bromide fragments was determined by the isolation of the methionine-containing tryptic peptides from apolipoprotein-glutamine-I. Inspection of the sequence of apolipoprotein-glutamine-I suggests an interesting distribution of amino acids that may account for its helical structure and its ability to bind and transport lipid.


Evidence for cholinergic synapses between dissociated rat sympathetic neurons in cell culture. Sympathetic principal neurons were dissociated from superior cervical ganglia of new-born rats, and grown in cell culture. In electrophysiological experiments two types of excitatory synapses were found. One, which was relatively rare, was shown to operate by electrical transmission. The other, the predominant type, had several characteristics of chemical transmission, and pharmacological evidence indicated it was cholinergic.


Change in state of spin labels bound to sarcoplasmic reticulum with change in enzymic state, as deduced from ascorbate-quenching studies. The ATPase (EC 3.6.1.3) of sarcoplasmic reticulum vesicles was reacted to various extents with thiol-directed spin labels. By suspension of the preparation in appropriate solutions, the enzyme could be placed and held in certain intermediate states of the ATPase cycle, or it could be set into steady-state catalysis. Ascorbate added to the system destroyed the spin-label signals with undetectable distortion of the electron paramagnetic resonance spectrum. In general, in the presence of ascorbate, undestroyed signal as a function of time could be described as the sum of two first-order reductions going on in separate compartments with different ascorbate concentrations. In different enzymatic states the proportion of total signal in the two compartments was different, but the first-order velocity constants remained the same. If the labeled membrane was first attacked with Triton, then exposed to ascorbate, signal was destroyed according to a single first-order constant, equal to the faster of the two constants observed with intact membrane, and equal to the constant whereby ascorbate attacks free label in solution. The data were reconciled by a simple rotary model, envisioning that an enzymatic state corresponds to an average angular position of the ATPase and thereby determines the proportion of labeled thiols exposed to external and internal ascorbate concentrations.


Host control of endogenous murine leukemia virus gene expression: concentrations of viral proteins in high and low leukemia mouse strains. Two of the major molecular components of murine leukemia virus particles, the internal protein (p30) and the envelope glycoprotein (gp69/71) have been measured in the spleens of normal, 6- to 10-week-old mice of various inbred strains and crosses. Both proteins were detected in virtually all mice. Extracts of high leukemia, high murine leukemia virus strains (AKR, C58, PL) showed high levels of both proteins; extracts of other strains usually showed lower levels. Of particular interest, however, were the exceptions to these general observations: (1) Very little gp69/71 could be detected in spleens of BALB mice, and this trait was dominant in crosses with AKR and DBA/2, both of which express a high level of gp69/71. Thymus-deficient BALB/c-nu/nu (nude) mice, in contrast, showed a higher concentration of gp69/71 typical of other low leukemia strains, suggesting that the virtual absence of the protein in normal BALB/c mice may result from immunologic suppression. (2) With C57L, C57BL/10Sn, and C57BL/6 strains the concentration of p30 was lower, in some cases much lower, than would be expected from the concentration of gp69/71. (3) DBA/2 mice showed high levels of gp69/71, 10-fold greater than that of p30, whereas congenic DBA/2-Fv-1(b) mice showed the opposite pattern. (4) Mice of 129-G(IX) (-) strain showed no detectable levels of either p30 or gp69/71 proteins, although the congenic 129 (G(IX) (+)) showed appreciable levels of both. The absence of these proteins in 129-G(IX) (-) mice is a recessive trait, as F(1) hybrids with AKR and DBA/2 showed appropriate levels of both proteins. It is concluded that expression of viral p30 and gp69/71 proteins in mice is not coordinately linked and that expression is complex, being influenced by several genes, including Gv-1, H-2, Fv-1, and probably still others.


13C nuclear magnetic resonance spectroscopic evidence for hydrophobic lipid-protein interactions in human high density lipoproteins. Phosphatidylcholines, sphingomyelins, cholesterol, and cholesterol esters were enriched with (13)C by chemical synthesis in specific positions of their hydrophilic groups and aliphatic chains. Their spin-lattice relaxation times were determined in organic solvents. The substances were organized as liposomes and recombined with total human high density apolipoproteins and the two separated main components, apolipoprotein A-I (apoLp-Gln-I) and apolipoprotein A-II (apoLp-Gln-II). These (13)C nuclear magnetic resonance data established that in reassembled high density lipoproteins the phospholipid molecules bind to the apoprotein moieties with their hydrophobic fatty acid chains and not with their hydrophilic zwitterionic groups. Apolipoprotein A-I preferentially binds phosphatidylcholine, although its lipid-binding capacity is smaller than that of apolipoprotein A-II. Apolipoprotein A-II avidly reassembles with sphingomyelin by hydrophobic interactions. A model of the molecular organization of the high density lipoportein particle has been derived.


13C nuclear magnetic resonance spectroscopy of native and recombined lipoproteins. (13)C nuclear magnetic resonance data on native and recombined lipoproteins are reported. [Methyl-(13)C]phosphatidylcholine, [methyl-(13)C]sphingomyelin, 1,2-[dioleoyl-1-(13)C]-sn-phosphatidylcholine and cholesteryl-[1-(13)C]oleate were enriched with 90% carbon-13 in respective molecules by chemical synthesis and used for recombination experiments with high density lipoprotein apoproteins. Relaxation times for these specifically enriched lipids in organic solvents, (2)H(2)O, and lipid-protein complexes isolated by ultracentrifugal flotation, were measured. The results show that both the phosphatidylcholine and sphingomyelin polar headgroups have the same hydrophilic environment in either sonicated lipid particles or reassembled lipoproteins, and suggest that ionic interaction of lipid and apolipoproteins is of minor importance in the formation of plasma lipoprotein complexes. Our experiments indicate that (13)C nuclear magnetic resonance spectroscopy will contribute to the understanding of lipidprotein interaction in lipoproteins and membranes.


Simian virus 40 T antigen binds to DNA.

Simian virus 40 T antigen binds to DNA. The T antigen of simian virus 40, which may play a role in the control of viral DNA replication, is recovered from nuclei of cells transformed by simian virus 40 in several forms sedimenting at different rates. The large molecular weight forms are converted to the smallest (5 S) form by high salt, suggesting that they differ in the degree of aggregation. All the forms of the antigen bind efficiently to double-stranded DNA-cellulose columns at pH 6.2 and low salt, and elute in two fractions: one at pH 8.0 and low salt, the other at pH 8.0 and high salt. The antigen has little affinity for single-stranded DNA.


Necrolytic migratory erythema with glucagon-secreting tumour of the pancreas.


Type C viral expression in primate tissues. Nucleic acid sequences homologous to a [(3)H]DNA transcript prepared from an endogenous baboon type C virus are readily detected in both the cellular DNA and RNA of several different Old World monkeys. Competitive radioimmunoassays for the major viral protein (p30) of baboon type C viruses detect viral antigen in a normal stumptail spleen and a rhesus ovarian carcinoma. The p30 antigen from these tissues is closely related by several immunologic criteria to the p30 protein of baboon type C viruses. The results indicate that normal primate tissues transcribe endogenous viral-specific RNA and translate at least one viral structural protein.


Diagnosis and management of insulinoma.

Diagnosis and management of insulinoma.


Emiocytosis: a possible molecular mechanism.


Equilibrium between metabolic pathways producing energy: a key factor in regulating lipolysis.


Cyclophosphates VI. Cyclophosphates as substrates and effectors of phosphodiesterase.


Sodium preference induced by angiotensin in the rat.


The concept of the quasi-abstinence effect and its use in the investigation of dependence mechanisms.


Effects of ACTH on conditioned suppression: a time and strength of conditioning analysis.


Duration of paradoxical sleep necessary for the acquisition of conditioned avoidance in the rat.


Polypeptide influences on attention, memory and anxiety in man.


Proceedings: Evolutionary role of neuromelanin.


Proceedings: Drug and sociotherapy in the aftercare of schizophrenic patients.


The effect of internally deposited plutonium-239 on the lysosomes of rat liver.


The extraction of the yet unused wealth of information in diagnostic radiology.


Adenohypophyseal function during cerebral angiography.


Effect of daytime alpha rhythm maintenance on subsequent sleep.


Heart rate levels of black and white newborns.


Prostaglandin-sepharose: application to the purification of bovine lung 15 (S) -hydroxyprostaglandin dehydrogenase.


The hypothalamic "savage" syndrome.

The hypothalamic "savage" syndrome.


Experimental sheep pox. A histological and ultrastructural study.


Oestrogen excretion by sows with induced cystic ovarian follicles.


Inhibition of hepatic drug metabolism by cyclic 3',5'-adenosine monophosphate.


Antagonism of the dipsogenic action of intraseptal angiotensin II in the rat.


Acute lymphoblastic leukemia of childhood: results of combination therapy.


Fluorescent antibody inhibition for determination of serum antibodies against the enterotoxin of Clostridium perfringens type A.


Studies on human serum high-density lipoproteins. II. Isolation of subfractions in the cold.


Megaduodenum. A case with bacterial overgrowth, deconjugation of bile salts, malabsorption, and polyneuropathy.


Ultrastructural changes in jejunal epithelial cells in liver cirrhosis.


Adrenocortical function in children with juvenile rheumatoid arthritis and other connective tissue disorders.


FL 1039 in bacteriuria following prostatectomy. A double-blind comparison with pivampicillin and placebo.


Emphysematous cholecystitis--an important clinical variant of acute cholecystitis.


Reversal of catecholamine refractoriness by inhibitors of RNA and protein synthesis. The generation of adenosine 3',5'-monophosphate (cyclic AMP) in response to catecholamines in the 2B subclone of RGC6 rat glioma cells previously exposed to norepinephrine and refractory to further norepinephrine addition is substantially increased by addition of inhibitors of RNA and protein synthesis. The time course of the effect of these inhibitors on cyclic AMP concentration suggests that rapid protein synthesis and turnover are involved in catecholamine refractoriness. Norepinephrine induction of cyclic nucleotide phosphodiesterase is demonstrable in RGC6 cells but not in the 2B subclone. Thus, catecholamine refractoriness cannot be attributed to induction of phosphodiesterase. This implies that induction of a protein or proteins, important in catecholamine refractoriness, affects the synthesis rather than the degradation of cyclic AMP.


Leukemia and lymphoma in experimental and domestic animals.


Etiologic factors in autoimmune hemolytic anemia.


Psychotherapy with donors and recipients of kidney transplants.


The West Philadelphia Community Mental Health Consortium in retrospect: supraprocess and infraprocess.


Mental health counselors--new professionals? The NIMH pilot group ten years later.


Behavioral effects of cortisol in man.

Behavioral effects of cortisol in man.


"Delayed" iatrogenic diseases.

"Delayed" iatrogenic diseases.


Adenovirus type 11 epidemic conjunctivitis in Singapore.


Epidemic haemorrhagic conjunctivitis associated with adenovirus type 11 in Taiwan.


Immunological tests in asymptomatic intestinal amoebiasis.


Axenic cultivation of four strains of Entamoeba histolytica from liver abscesses.


Dynamics of activity of redox enzymes in ontogenesis of Colorado beetle (Leptinotarsa decemlineata Say).


Oestrogen, headache and oral contraceptives.


Cervical synovial sarcoma in a young boy.


Liver aspiration cytology.

Liver aspiration cytology.


Toxicity and carcinogenicity of some South African cycad (Encephalartos) species.


Inflammatory carcinoma of the breast.

Inflammatory carcinoma of the breast.


Radiologically occult lung cancer. Report of 26 cases.


Results of treating malignant melanoma intralymphatically with radioactive isotopes.


Low cerebro-spinal fluid sugar associated with malignant glioma.


Immune responses in patients with gliomas.


Structural changes during preparation of autogenous venous grafts.


X-ray diffraction analysis of quartz in lung tissue.


Immunological responsiveness in rats infected with the Soehner-Dmochowski murine sarcoma virus (MSV-SD).


Antimicrobial therapy in experimental pseudomonas infection.


Effect of fulvine on pulmonary arteries and veins of the rat.


Response of patients receiving high dose beclomethasone dipropionate.


Enhancement of plasminogen activator by vasopressin and adrenaline: a role of cyclic AMP?


Membrane fusion in the growth cone-microspike region of embryonic nerve cells undergoing axon elongation in cell culture.


Fine structure of ocelli in sphinx moths.


A preliminary report on complex fibrillar aggregates in the gill epithelium of Panulirus interruptus (Randall).


Crystalline inclusions in the pituitary gonadotrophs of estrogen-primed, spayed rhesus monkeys (Macaca mulatta).


Effects of dibutyryl cyclic AMP on carbohydrate and lipid metabolism.


Obesity and pituitary lipolytic hormones.


Adenosine kinase from normal mouse erythrocytes and from Plasmodium chabaudi: partial purification and characterization.


The production of blood cell stasis and endothelial damage in the blood vessels of chick embryos treated with ultrasound in a stationary wave field.


Cyclic 3',5'-AMP-stimulated and non-stimulated phosphorylation of protein fractions from rat-liver cell sap on incubation with (gamma-32P)ATP.


Active site phosphopeptides from pea seed nucleoside diphosphate kinase.


(32P)phosphoryl transfer by endogenous protein kinase at the Ehrlich cell surface into extrinsic acceptor proteins.


Innervation of the detrusor muscle and urethra.


Sphincter electromyography.

Sphincter electromyography.


Symposium on renal lithiasis. Medical evaluation of urolithiasis. Etiologic aspects and diagnostic evaluation.


Symposium on renal lithiasis. Renal lithiasis in review.


Symposium on renal lithiasis. Urinary tract infection and renal lithiasis.


Genetic determinants of urologic disease.


Studies on the nucleic acid metabolism of renal tumour cells in vitro.


Clostridial cystitis emphysematosa.

Clostridial cystitis emphysematosa.


Shedding patterns of herpes simplex virus and cytomegalovirus among chronic dialysis patients.


Secondary hyperparathyroidism in rats with experimentally induced pyelonephritis.


Spontaneous neoplasms in aging Gerbillinae. A summary of forty-four neoplasms.


An indirect haemagglutination test for the detection and assay of antibody to infectious bovine rhinotracheitis virus.


Recent studies with etamiphyllin camsylate.


Airborne stability of swine vesicular disease virus.


Interaction of phage P2 DNA with some fast-sedimenting host components during infection.


Temperature-sensitive mutants of herpes simplex virus type 1: isolation, complementation and partial characterization.


Phosphoproteins, structural components of rhabdoviruses.


Control of transcription during the expression of the bluetongue virus genome.


Polyoma virus proteins: a description of the structural proteins of the virion based on polyacrylamide gel electrophoresis and peptide analysis.


Studies on the type C viral replication defect in MSV-transformed rat nonproducer variant clones.


Electron microscopic studies of temperature-sensitive mutants of herpes simplex virus type 1.


Cucumber mosaic virus-induced RNA polymerase: partial purification and properties of the template-free enzyme.


The persistence and expression of virus-specific DNA in revertants of Rous sarcoma virus-transformed BHK-21 cells.