Use of purified polysomes from rabbit reticulocytes in a specific test for initiation factors. Initiation factors, extracted from ribosomal particles by high salt, are usually tested for with the extracted ribosomes. However, it is theoretically possible that such tests may respond not only to factors (i.e., proteins that join and leave a ribosome during its cycle), but also to true ribosomal proteins that may have been extracted. We have eliminated this circularity by tests with purified polysomes, which have not been extracted with high salt; the polysomes are deficient in initiation factors because they have been largely separated from the native subunits. Tests with both systems, applied to extracts of different classes of particles, suggest that high salt does extract both initiation factors and essential ribosomal proteins. Extracts of native subunits contain both, and stimulate both systems; while, in the presence of these extracts, the extracts of polysomes further stimulate only the extracted ribosomes.


D-nor steroids: anomalous conformation and reactivity of C-D-cis D-norandrostanes. The C/D-cisD-norandrostanes 1a, 1b, 1c, 2a, 2b, and 2c were prepared and their reactivity studied. Whereas carbonium ion reactions of 1b and 1c are readily interpreted on the basis of their assigned stereochemistry, reactions of 2b and 2c suggest that these compounds react via conformations in which the 16beta-substituents are pseudoequatorial, requiring a ring C boat conformation as shown in formula 3b. X-ray crystallographic studies on 1a and 2a establish that while 1a has the expected conformation, 2a exists preferentially with ring C in the boat form. Molecular models suggest that this is the result of severe nonbonded interactions in the alternative conformation (3a) in which a chair C ring is retained.


Distribution of bupivacaine in the rabbit under normal and acidotic conditions.


Germ line basis for antibody diversity: immunoglobulin VH-and CH-gene frequencies measured by DNA-RNA hybridization. The reiteration frequency for mouse immunoglobulin V(H)-genes and C(H)-genes has been directly estimated by hybridization of purified MOPC 315 alpha-chain mRNA with a vast excess of mouse DNA. A biphasic C(o)t curve resulted. The low C(o)t transition (C(o)t(1/2) about 1.5) was interpreted as hybridization to V(H)-genes and the high C(o)t transition (C(o)t(1/2) about 10(3)) as hybridization to C(H)-genes. These values correspond to about 5000 V(H)-genes and less than 8 C(H)-genes. This germ-line content of V(H)-genes is sufficient to account for antibody diversity given a comparable set of V(L)-genes. Minimal-gene models are invalidated and there is no need to invoke somatic generators of diversity.


Computerized anaesthetic record-keeping. A clinical study of the preanaesthetic data, the risk groups and the choice of anaesthetic method.


Urometry in vesico-ureteral reflux. Pressure recordings in refluxing and non-refluxing urinary tracts of children.


Korsakoff-like amnesic syndrome in penetrating brain injury. A study of Finnish war veterans.


Growth and spread of laryngeal and hypopharyngeal carcinoma with reflections on the effect of preoperative irradiation. 139 cases studied by whole organ serial sectioning.


Distorted speech audiometry. A methodological and clinical study.


The mechanics of the expiration evaluated by a model.


Topography of the monoamine neuron systems in the human brain as revealed in fetuses.


Studies on the inhibitory nervous control of gastric motility.


Evaluation of the effects of 5,7-dihydroxytryptamine on serotonin and catecholamine neurons in the rat CNS.


The flag of the Royal Australasian College of Surgeons.


Bilateral cervical rib and subclavian aneurysm.


Superior vena cava obstruction: resection and bypass for malignant lesions.


The intraarterial use of tetracycline in the treatment of two patients with digital gangrene secondary to obliterative arterial disease.


Glandula in glandula: the intrathyroid parathyroid.


Renal trauma in children: a ten-year review.


A case of giant ureteric polyp.

A case of giant ureteric polyp.


Knuckle pads.

Knuckle pads.


Congenital short bowel.

Congenital short bowel.


Annular pancreas in an adult.

Annular pancreas in an adult.


A unique case of fracture-dislocation of the spine.


Judicious turbinectomy for nasal obstruction.


Teratoma of the neck.

Teratoma of the neck.


A valve at the bladder outlet.

A valve at the bladder outlet.


Neuromuscular reflexes in Hirschsprung's disease.


The function of the isolated perfused pig liver after cooling.


Pharmacokinetics of 1-beta-D-arabinofuranosylcytosine in humans.


Perfusion between the lateral ventricles in the study of experimental hydrocephalus.


Deficit in cerebrospinal fluid absorption in patients with symptoms of normal pressure hydrocephalus.


An EEG device for monitoring seizure discharges.


Concentration of carbamazepine (Tegretol) in serum and in cerebrospinal fluid in patients with epilepsy.


The seizures of benign childhood epilepsy with Rolandic paroxysmal discharges.


Rehabilitation in epilepsy. A follow-up study of 427 epileptics in the period 1969-1972.


Paroxysmal depolarization and changes in action potentials induced by pentylenetetrazol in isolated neurons of Helix pomatia.


Cobalt experimental epilepsy in various strains of rat.


Concentration of amino acids in the brain of cobalt-epileptic rat.


Secondary epileptogenic EEG focus in temporal lobe epilepsy.


Experimental thalamic focus and thalamocortical epileptogenic mechanisms in the brain of turtle.


Post-rotational nystagmus. An unreliable sign of diphenylhydantoin toxicity.


Principles for clinical testing of antiepileptic drugs.


The state of the college.

The state of the college.


Third Party Programs. Implications for the future.


Proposed recommendation for change in American College of Dentists, Inc. bylaws.


Professionalism--Fact or Fantasy--Who needs it?


The nature of professionalism--its value to society.


Current challenges to the professions in America.


Professional misconduct of individuals.

Professional misconduct of individuals.


Professional misconduct of organizations and agencies.


Chromosome studies on rat leukemias and lymphomas, with special attention to fluorescent karyotype analysis.


Production of monospecific rabbit antihuman eosinophil serums and demonstration of a blocking phenomenon.


Responses of a chemoreceptor to mechanical and electrical stimulation in the frog tongue.


Composition, fluorescence, and circular dichroism of rat lysozyme.


Continuing education.

Continuing education.


Cementifying fibroma: Report of three cases.


Rinsing study--self application of fluoride in East Vancouver.


Establishing rapport: phase I, the first four minutes.


Diet counselling to prevent caries.

Diet counselling to prevent caries.


Tension pneumothorax following induction of anesthesia.


Rapid pin expanding prosthesis in the cleft lip/palate infant.


Conscious awareness with I don't careness.


Modification of cardiovascular effects of ketamine by diazepam.


Oral precancerous conditions frequency in 1648 Malaysians with correlation to oral habits.


The prenatal value of fluoridated water.


Changes in the tissues adjacent to oral squamous cell carcinomas.


The history, composition, chemistry & pharmacology of the betel-tobacco chew (QUID.).


Final steps to a successful retirement.

Final steps to a successful retirement.


Keogh vs. corporations: Now who's on first?


Erosive lichen planus: report of a case.


Is dental education going in the right direction?


Fit into tomorrow.

Fit into tomorrow.


Bruxism, occlusion, and restorative dentistry.


HMO dentist: Is it for you?

HMO dentist: Is it for you?


Variety is the staple of the public health dentist.


Group.

Group.


Do you know what you're looking for?

Do you know what you're looking for?


Let the computer take the labor out of site selection.


Needed: Dentists to help dentists keep learning.


Drugs for comprehensive treatment of patients.


Building an effective dentist-pharmacist relationship.


Drug interactions of chemotherapeutic agents.


HMO as a dental care delivery system.

HMO as a dental care delivery system.


Trade that operatory for a desk?

Trade that operatory for a desk?


The role of breakfast in preventive dentistry.


The use of U-V cured composite in the treatment of fractured anterior teeth.


Endodontic preparation.

Endodontic preparation.


Are your patients as healthy as you think they are, doctor?


The consumer's viewpoint of dental hygiene.


The clinical laboratory--what it means to you and your patients.


Expanded duties. Implementation and control of a team dental practice.


The traditional dental hygienist: a factual review.


The Food and Drug Administration and its position in regard to new dental and oral drugs.


Organizing for instruction.

Organizing for instruction.


Optimum use of dental hygienists in health care.


An index to Philippine dental literature.


Some thoughts on the medical management of renal stones.


Diagnostic laboratory test--who needs it?


Loose vs tight fitting of silastic prosthesis of the MP joint of the hand.


Asymptomatic Mullerian anomalies.

Asymptomatic Mullerian anomalies.


Use of lingual ascorbic acid test in assessing vitamin C status.


Uremic constrictive pericarditis.

Uremic constrictive pericarditis.


Oral disease--infective or degenerative?


Navy periodontal screening examination.

Navy periodontal screening examination.


The use of liver function tests.

The use of liver function tests.


The vanishing dentist.

The vanishing dentist.


Possible coagulation defects seen in Rocky Mountain spotted fever.


Unusual abnormalities associated with the floppy mitral valve syndrome.


Two methods of treatment of muco-gingival periodontal lesions.


Variant angina pectoris.

Variant angina pectoris.


Political action. The prelude to state legislation.


The use of fluorescent dye in evaluation of application and retention of fissure sealers.


HMOs. Can they maintain health?

HMOs. Can they maintain health?


Letter: Craniospinal irradiation and immunity.


Some considerations on massive stomach bleeding complicated with head and neck cancers.


The effect of staphylococcal antigen on the output of cells from the popliteal lymph node of immunized sheep.


The geographic distribution of carcinomas of the small intestine in New Zealand sheep.


The incidence and microbiology of otitis externa of dogs and cats in New Zealand.


Methylmalonic acid excretion and incipient cobalt deficiency disease in sheep.


Letter: Fasciola hepatica in sheep: a preliminary epidemiological study.


Letter: Chronic granular rhinitis (nasal catarrh) of cattle.


Letter: Hydrallantois in Ayrshire cows.

Letter: Hydrallantois in Ayrshire cows.


Dentistry: Where the NHS has failed.

Dentistry: Where the NHS has failed.


A discussion about resistance of enamel.


A-Z of practice management. V is for valour.


Rubber for denture linings.

Rubber for denture linings.


Pathological gemination of second and third upper molars.


Triplet-triplet energy transfer in alpha-trypsin. Experiments are reported that demonstrate that light absorbed by ionized tyrosinyl sensitizes the phosphorescence of tryptophanyl residues of native alpha-trypsin. The sensitization effect is abolished when alpha-trypsin is unfolded in guanidine hydrochloride. Under the experimental conditions used, the tryptophan phosphorescence could only have been induced by an electron-exchange interaction. These results, therefore, require that there be at least one ionized tyrosinyl-tryptophanyl pair in the native enzyme and that the distance between the two side chains be sufficiently short to permit electron exchange.


The effect of aspirin on sickling and oxygen affinity of erythrocytes. The recent suggestion that the administration of aspirin might be useful in the treatment of sickle-cell anemia has been further studied and found to be without basis. After incubation with aspirin, sickle-cell erythrocytes are not inhibited from sickling after deoxygenation. In addition, although aspirin does transfer the acetyl group to hemoglobin both in vitro and in vivo, in our experiments the reaction does not result in any alteration in the oxygen equilibrium of either intact erythrocytes or hemoglobin in solution. Furthermore, patients maintained on long-term aspirin administration also showed no shift in the oxygen affinity of their blood.


The purification of choline acetyltransferase of squid-head ganglia. Choline acetyltransferase (EC 2.3.1.6) isolated from the head ganglia of squid could be purified by use of mercurial-Sepharose columns as well as Sepharose columns to which the enzyme inhibitor p-(m-bromophenyl)vinyl pyridinium had been attached. These columns, in conjunction with 30-55% ammonium sulfate precipitation, 40-30% ammonium sulfate extraction, chromatography on sulfopropyl-Sephadex and on cellulose phosphate and hydroxylapatite columns, led to the isolation of three factions of choline acetyltransferase ranging in activity from 1000 to 4000 mumole/mg of protein/per hr. Polyacrylamide gel electrophoresis suggests that two of these fractions are homogeneous. The squid choline acetyltransferase is different from the mammalian-brain enzymes in having a larger molecular weight under the conditions used and in being relatively poorly inhibited by styryl pyridinium compounds.


Molecular orbital calculations of magnetic circular dichroism spectra: a benzene-indole sequence. The magnetic circular dichroism of benzene and indole derivatives was measured down to 190 nM. The following pairs of molecules have magnetic circular dichroisms of the opposite sign in the B(2u) absorption region: aniline and benzonitrile, indene and indoline, indole and 4-aminoindole, and 4-aminoindole and 5-aminoindole. The sign and magnitude of the magnetic circular dichroisms observed are in good agreement with those calculated by the semiempirical self-consistent field with configuration interaction Pariser-Parr-Pople method with incorporation of variable pi-electronegativity and sigma-polarization. The energy dominator in the magnetic rotational strength expression serves to limit the important contributions to a few terms only.


Purification of a family of specific messenger ribonucleic acids from moth follicular cells. When moth follicular cells synthesize the characteristic, low-molecular-weight chorion (eggshell) proteins, they contain at least two groups of 8-9S RNAs which appear to be chorion mRNA. This class of RNA yields a characteristic radiolabeled profile on polyacrylamide slab gels. The same profile is obtained irrespective of whether lebeling is performed in vivo or in organ culture, and whether the RNAs are purified from whole cells or specifically released from polysomes. Polysomes contain putative chorion mRNA only when the cells actually synthesize chorion protein. The RNA size is correlated with the size of the chorion proteins: two month species differing in the size distribution of their chorion proteins show a corresponding difference in the size distribution of the RNAs.


Sodium uptake associated with activation of action potential ionophores of cultured neuroblastoma and muscle cells. Veratridine, an activator of action potential Na(+) ionophores, stimulated passive Na(+) uptake by electrically excitable neuroblastoma and muscle cells but had no effect on clonal cell lines defective in Na(+)-ionophore activity. Veratridine-dependent Na(+) uptake was completely inhibited by tetrodotoxin, a specific inhibitor of the action potential Na(+) ionophore. Half-maximal inhibition was obtained with 11 nM tetrodotoxin. Thus, veratridinedependent Na(+) uptake provides a specific and convenient means of assaying populations of cultured cells for action potential Na(+)-ionophore activity.


The function of the two subunits of thermophilic aminopeptidase I. The thermophilic high-molecular-weight aminopeptidase I (EC 3.4.11.1) from Bacillus stearothermophilus is composed of 12 subunits of two different types (alpha,beta) which can combine in various ratios. Only one type of subunit (alpha) is needed for the degradation of neutral peptides, but dipeptides having amino-terminal aspartic or gultamic acid are substantially hydrolyzed only by enzyme containing the other subunit (beta) as well. Asp-Gly inhibits the enzymatic hydrolysis of glutamic acid 1-(4-nitroanilide) very strongly but hardly affects the hydrolysis of leucine p-nitroanilide. These results indicate that both types of subunit have hydrolytic activity but different specificity. The two subunits have identical molecular weights and their amino-terminal regions are homologous, suggesting that the two chains originate from a single ancestral gene by gene duplication and independent mutation.


A magnetic suspension osmometer.

A magnetic suspension osmometer. The magnetic suspension balance is used for the measurement of very small osmotic pressures. The apparatus is essentially the same as that previously used for the measurement of the density and viscosity of protein solutions except that the magnetically suspended buoy is modified to make it pressure sensitive. The method is especially useful for the measurement of osmotic pressure in small samples of dilute solutions (about 10(-6) M) or of substances with molecular weights greater than 10(5). A height-sensing device has been developed which is not dependent upon the visual precision of the operator.


Enzymatic activities of carobxypeptidase A's in solution and in crystals. Activities of all known forms of bovine carboxypeptidase A's (alpha having 307, beta having 305, and gamma having 300 amino acids) are essentially the same in solution under given conditions. However, activities in the crystals differ. The A(alpha) crystals elongated along the a axis (a) have unit cell parameters a = 51.41 A, b = 59.89 A, c = 47.19 A, and beta = 97 degrees 35', (b) show about [unk] of the activity of the dissolved enzyme, and (c) have the same color of the arsanilazo Tyr 248 derivative in the crystalline and solution states, namely red at pH 8.2 and yellow at pH 7.4. The A(gamma) crystals elongated along the b axis (a) have unit cell parameters a = 50.9 A, b = 57.9 A, c = 45.0 A, and beta = 94 degrees 40', (b) show [unk] of the activity of the dissolved enzyme, and (c) show, in the arsanilazo Tyr 248 derivative, yellow crystals and red solution at pH 8.2. Although the detailed three-dimensional structure is known for the A(alpha) form described above, the structure of the A(gamma) form is as yet undertermined. A reasonable hypothesis is that the major part of the differences in crystal behaviors is due to differences in intermolecular (crystal-packing) interactions. In particular the movement of Tyr 248 may be somewhat hindered by these intermolecular contacts in the A(gamma) crystals, and in other crystalline forms which are elongated along the b axis. The movement observed in the x-ray diffraction studies, of the OH group of Tyr 248 by 12 A when the very slowly hydrolyzed substrate Gly-Tyr is bound to A(alpha) crystals, appears to be largely unhindered by intermolecular interactions. Examination of a three-dimensional space-filling structural model of the carboxypeptidase A molecule reveals that the phenolic oxygen of Tyr 248 can approach within 2 A of the Zn cofactor. This approach requires a movement by about 6 A of the polypeptide chain in the general region of Tyr 248. Moreover, the position of Tyr 248 when bonded to Zn can just be seen in the electron density map of the crystal structure at a level which, averaged over many unit cells, suggests some 15-25% of the enzyme is in this form at pH 7.4 and 4 degrees in the crystals of the x-ray diffraction study. It is probable that when the Zn-Tyr 248 bond is present the enzyme is catalytically inactive.


300-MHz nuclear magnetic resonance study of oxytocin aqueous solution: conformational implications. The 300-MHz nuclear magnetic resonance spectrum of the peptide hormone, oxytocin, in water, was obtained. Extensive nuclear magnetic resonance spindecoupling experiments, including those involving irradiation of the alpha-proton resonance under the water peak, studies using partially deuterated hormone derivatives, and nuclear magnetic resonance studies of some precursor peptides to oxytocin, permitted us to assign most of the proton resonance of the hormone unambiguously. The JNalpha values and temperature dependence of the chemical shift of the peptide amide and carboxamide protons of oxytocin were also obtained. These studies indicate that, in aqueous solution, oxytocin is a flexible molecule possessing several different conformations. Corresponding studies of [4-leucine]oxytocin were also made, with similar results and conclusions.


Unique nuclear DNA sequences in the involved tissues of Hodgkin's and Burkitt's lymphomas. Previous studies have demonstrated that Hodgkin's, Burkitt's, and other human lymphomas contain particulate elements encapsulating 70S RNA and RNA-dependent DNA polymerase. [(3)H]DNA probes endogenously synthesized by these particles were used to demonstrate that the nuclear DNA of the lymphomas contain particle-related sequences that cannot be detected (less than 1/20th of a copy per genome) in the DNA of normal cells. This result agrees with our earlier findings in human leukemias. The data are inconsistent with any etiologic concept that invokes germ-line transmission of at least one complete copy of the particulate information associated with the malignancy. The unique sequences found in the nuclear DNA of Burkitt's and Hodgkin's tissues are related to each other but not to the DNA of the Epstein-Barr virus.


Effect of interferon treatment on cellular messenger RNA. Cell monolayers wre treated with interferon, and then were labeled with RNA precursors. Messenger ribonucleoprotein and transfer RNA were liberated from isolated polysomes, and analyzed by electrophoresis on polyacrylamide gels. The messenger ribonucleoproteins and transfer RNA from interferon-treated cells migrated slightly slower than did the corresponding components from control cells. It was shown that the differences in migration speeds was attributable to the fact that the messenger RNAs and transfer RNA that were polysomebound (i.e., being translated) were slightly larger than control-cell RNAs. This phenomenon was seen in mouse L cells, primary mouse-embryo cells, and rabbit-kidney cells. Ribosomal 28S and 18S RNA was not altered, nor was nuclear RNA. Several types of evidence indicate that the biochemical changes are attributable to the interferon in the preparations, and not to impurities. These data may bear on the mechanism by which interferon-treated cells recognize and translate viral RNA poorly. It is tentatively suggested that interferon treatment of cells leads to a change in cellular messenger RNA such that the cell can distinguish it from the subsequently infecting viral RNA.


Stimulation of hepatic beta-hydroxy-beta-methylglutaryl coenzyme A reductase activity in hypophysectomized rats by L-triiodothyronine. Diurnally varying activity of hepatic beta-hydroxy-beta-methylglutaryl coenzyme A reductase (EC 1.1.1.34) was decreased to very low levels in hypophysectomized rats with no discernable diurnal rhythm retained. Administration of triiodothyronine (100 mug/100 g of body weight) produced a supranormal level of reductase activity, about 3-4 times the highest activity found in normal rats. Reductase activity began to rise about 30 hr after hormone administration, maintained a constant high level from 48 to 72 hr, and declined to the control level by 96 hr. The supranormal response was elicited equally well either during the day or at night. When normal animals received triiodothyronine, reductase activity was increased only to a level comparable to the highest level found in normal rats. Administration of hydrocortisone markedly inhibited the triiodothyronine-induced increase in reductase activity. This finding suggests that glucocorticoids might act to suppress and thus account for the smaller increase in reductase activity observed in normal rats given triiodothyronine. When actinomycin D was given before the triiodothyronine-induced rise in reductase activity, the increase was effectively blocked, indicating that the hormonal effect requires new RNA synthesis.


The binding of riboflavin-5'-phosphate in a flavoprotein: flavodoxin at 2.0-Angstrom resolution. The crystal structure of the oxidized form of flavodoxin from Desulfovibrio vulgaris has been studied at 2.0-A resolution, and a detailed description of the region around the flavin mononucleotide binding site is now available. The flavin is between a tyrosine group, roughly parallel to it on one side, and a tryptophan, about 45 degrees from being parallel, on the other side. The two carbonyl groups and two nitrogen atoms of the flavin are hydrogen bonded to the peptide chain of the protein, while the two methyl groups are exposed at the surface of the protein. The phosphate group of the flavin mononucleotide is inside the protein and extensively hydrogen bonded to it. The ribityl group is hydrogen bonded both to the protein and to water on the surface of the protein.


The ultrastructure of ferritin macromolecules. The lattice structure of the core crystallites. The ultrastructure of the crystalline ferric mineral that forms the central core of ferritin macro-molecules has been examined by means of ultrahigh resolution electron microscopy at 100 kV. Very high magnification dark-field images reveal the presence of either a single large crystal or several smaller crystallites within many of the cores. When the highly crystalline core contents are suitably oriented to transmit their Bragg reflections through the objective aperture, regular fringes separated by 2-9.5 A have been visualized. The geometrical relations of lattice fringes and of periodically organized point details in these individual crystallites largely confirm the structural model proposed by Towe and Bradley (1967). The highly variable occupancy of ferric ions in certain planes of the lattice suggests that 20-33% of the iron content of fully saturated ferritin should undergo more rapid physiological release than does the remainder, and that iron uptake will have kinetics that depend upon more than only the maximal rate of crystallization.


Non-Mendelian inheritance of DNA-induced inositol independence in Neurospora. Inositol-independent (inos(+)) revertants of Neurospora induced in inositol-requiring mutants by treatment with wild-type DNA in previous studies were found to be stable and to grow well in the absence of inositol. Genetic data presented in this paper show that a major proportion of these induced revertants rarely transmitted the inositol independence character (inos(+)) to their sexual progeny. Non-Mendelian transmission of the transformed character (inos(+)) was also found to occur in some of the sexual progeny in subsequent generations. These genetic data support the idea that the transforming DNA pieces carrying the genetic information (called exosomes) are not readily integrated into the host genome. It is suggested that elimination of most exosomes during meiosis causes a loss of the genetic information and leads to non-Mendelian transmission of the induced revertant character (inos(+)).


Structure of hemoglobin M Boston, a variant with a five-coordinated ferric heme. X-ray analysis of the natural valency hybrid alpha(2) (+M Boston)beta(2) (deoxy) shows that the ferric iron atoms in the abnormal alpha subunits are bonded to the phenolate side chains of the tyrosines that have replaced the distal histidines; the iron atoms are displaced to the distal side of the porphyrin ring and are not bonded to the proximal histidines. The resulting changes in tertiary structure of the alpha subunits stabilize the hemoglobin tetramer in the quaternary deoxy structure, which lowers the oxygen affinity of the normal beta subunits and causes cyanosis. The strength of the bond from the ferric iron to the phenolate oxygen appears to be the main factor responsible for the many abnormal properties of hemoglobin M Boston.


Alkaline phosphatase activity in mouse teratoma. In tumors and embryoid bodies of mouse teratoma a correlation has been established between specific activity of alkaline phosphatase (EC 3.1.3.1) and content of embryonal carcinoma, the stem cell of the tumor. A histochemical study of embryoid bodies has shown that high levels of the enzyme are confined to embryonal carcinoma. Fifteen tissue culture lines could be classified into three groups: (a) lines identifiable as pluripotential embryonal carcinoma by their morphology, tumorigenicity, and capacity to differentiate in vivo; (b) nullipotential embryonal carcinoma, resembling pluripotential embryonal carcinoma in morphology and malignancy but giving rise to undifferentiated tumors; and (c) lines of apparently nonmalignant somatic cells. Both types of embryonal carcinoma possess levels of alkaline phosphatase 5- to a 100-fold higher than the somatic cell lines. The embryonal carcinoma enzyme resembles the enzymes from kidney and placenta in kinetics of thermal inactivation and sensitivity to the inhibitor L-phenylalanine, but is distinguishable from the alkaline phosphatases of liver and intestine. These findings are discussed in relation to the use of teratoma for the study of cell differentiation.


Purine metabolism in normal and thioguanine-resistant neuroblastoma. Purine metabolism has been examined in a clonal line of mouse neuroblastoma cells resistant to the cytotoxic effects of 6-thioguanine. Comparative studies in the resistant and parental lines indicate that the former cells have less than 1% of normal hypoxanthine phosphoribosyltransferase (EC 2.4.2.8) activity. The activities of other enzymes important in the de novo and salvage pathways of purine biosynthesis were not significantly different in the two lines. Hypoxanthine phosphoribosyltransferase deficiency in this neuroblastoma line was associated with increased intracellular concentrations of 5-phosphoribosyl-1-pyrophosphate, an increased rate of purine biosynthesis de novo, and failure to incorporate hypoxanthine, but not adenine, into nucleotides. There are essentially the same alterations in purine metabolism that occur in hypoxanthine phosphoribosyltransferase-deficient fibroblasts or lymphoblasts derived from individuals with the Lesch-Nyhan syndrome. Clonal lines of hypoxanthine phosphoribosyltransferase-deficient neuroblastoma cells may therefore be of use in elucidating the mechanisms by which the enzyme defect leads to the neurologic dysfunction seen in children with this disease.


Poly(inosinic acid)-poly(cytidylic acid) inhibition of DNA synthesis in synchronized HeLa cells. Inhibition by double-stranded polyribonucleotides of DNA synthesis in synchronized HeLa cultures is dose- and time-dependent. Inhibition by poly(I.C) primarily affected late G(1) and early S phases of the cell cycle. Single-stranded polynucleotides, native calf-thymus DNA, and yeast RNA had no effect. Radioautography showed that after 2-hr exposure the synthetic polyribonucleotides were predominantly inside the nucleus. The results extend the spectrum of action of double-stranded RNA.


Statistical mechanics applied to cooperative ligand binding to proteins. By using the lattice statistical argument, we have shown that for a protein whose subunits have the same number of neighbors, the three parameters (K(AB), K(BB), and K(S)K(t)) in the sequential theory formulated by Koshland, Nemethy, and Filmer [Biochemistry (1966) 5, 365] can be reduced to two parameters. One of the parameters, Z, measures the strength of the subunit interactions and is related to the apparent free energy of interaction (DeltaF degrees I) by Z = exp (-DeltaF degrees I/2mkT), where m is the number of neighbors in a subunit and kT has the usual meaning. In addition, we relate Wyman's allosteric binding potential [Advan. Protein Chem. (1964) 19, 223] to the canonical partition function of the McMillan-Mayer theory [J. Chem. Phys. (1945) 13, 276]. An explicit form relating the apparent free energy of interaction and the Hill coefficient is given for an allosteric protein that has nonequivalent and independent ligand-binding sites. The present formulation can be used to account for a number of recent experimental results on hemoglobins.


Stereochemical trigger for initiating cooperative interaction of the subunits during the oxygenation of cobaltohemoglobin. Relative to the standard provided by an unconstrained five-coordinate imidazoleiron(II) porphyrin, the axial separation (N(epsilon)...P(mu)) in deoxyhemoglobin of the complexed histidine-nitrogen (N(epsilon)) atom from the mean plane (P(mu)) of the protoporphyrin is stretched by [unk] 0.30 A. Retention of the same globin framework (quaternary structure) in deoxycobaltohemoglobin implies an axial connection with the cobalt protoporphyrin that carries enhanced tension, but a somewhat smaller value of N(epsilon)...P(mu) than the 2.90 A observed in deoxyhemoglobin. Structural constraints imposed on and by the globin in support of tension in the axial linkage are conducive to doming of the entire 24-atom porphine skeleton of the protoporphyrin toward the metal (M) atom. Furthermore, the presence of an odd electron in the 3d(z) (2) orbital of the metal atom is responsible for an easily stretched M-N(epsilon) bond. It then appears that moderate doming of the porphinato core in combination with modest stretch in the Co-N(epsilon) bond can readily lead to an N(epsilon)...P(mu) distance approaching 2.90 A in deoxycobaltohemoglobin and, consequently, to compatibility with Perutz's postulated trigger for the initiation of cooperative interaction of the subunits during the reversible oxygenation of hemoglobin.


Still more genetic variability in natural populations. Heat-denaturation studies of xanthine dehydrogenase have revealed many more additional alleles at the locus controlling this enzyme than are revealed by electrophoretic studies. In natural populations of species in the virilis group of the genus Drosophila, heat-denaturation studies of flies from the same locality revealed 1.74 times as many alleles as did electrophoretic studies. Similarly, studies of several species over their geographic range also revealed 1.74 times as many alleles. In addition, for the nine species studied, electrophoretic analysis had revealed only 11 alleles within the group, whereas heat-denaturation studies revealed a total of 32 alleles. These findings are discussed in the light of the continuing controversy over Darwinian and non-Darwinian theories of evolution.


Navy Dental Corps casualty treatment training program.


Personality correlates and plaque scores.


Preventive dentistry--new concepts.

Preventive dentistry--new concepts.


Who will establish the rules?

Who will establish the rules?


Digital computer analysis of circulatory and respiratory pressures in water-immersed dogs breathing liquid in force environments of 1 and 7 Gy.


The effects of camptothecin on mammalian DNA.


Letter: Thrombin cell block: a critique.


Peliosis-like changes induced by phalloidin in the rat liver: a light and electron microscopic study.


Cytologic changes of the respiratory epithelium in iron foundry workers.


Erythropoietin activity in isolated canine liver-kidney perfusion after pretreatment of donor animals.


Materia cytotechnologica. Anatomy of a test. I.


Unusual ciliated epithelial cells from an ovarian cyst.


Change in overbite: a ten-year postretention study.


Variations in edgewise biomechanics.

Variations in edgewise biomechanics.


Familial osteogenic sarcoma.

Familial osteogenic sarcoma.


Combined orthodontic and surgical management of maxillary protrusion in adults.


Treatment planning in maxillary prognathism.


AAO Orthodontic Review Committee Guidelines.


Steroid anaesthesia--its discovery and development for clinical use.


AAO governmental dependence on the eight constituent societies.


Supplemental diazepam.

Supplemental diazepam.


Treatment of neoplastic subtrochanteric fracture. Six cases treated with the Zickel nail.


Case report: Tooth replantation, treatment after oral injury.


Excessive occlusal wear.

Excessive occlusal wear.


Root sensitivity reduced by rubbing with paste.


A tool to aid placement of class V restorations.


Extraoral swelling of the face and neck.


A simplified technic to achieve minor tooth movement in adults.


"Jungle safari" theme excites young patients.


Editorial: Include me out?

Editorial: Include me out?


Letter: Statement from Aetna.

Letter: Statement from Aetna.


Letter: Plea for uniformity.

Letter: Plea for uniformity.


Letter: S mutans and caries.

Letter: S mutans and caries.


Letter: Myofascial pain dysfunction.

Letter: Myofascial pain dysfunction.


American Fund for Dental Health.

American Fund for Dental Health.


Dental health exhibit opens in Chicago.

Dental health exhibit opens in Chicago.


Christian Dental Society volunteers upgrade dental care in developing nations.


Report of a breakthrough in preventive dental care for a National Football League team.


Prediction of tetracycline-induced tooth discoloration.


Guides to orthodontic treatment timing.

Guides to orthodontic treatment timing.


Patient exposures from intraoral radiographic examinations.


Screening for hypertension in the dental office.


Retrieving broken endodontic instruments.


Extraction of a horizontally transmigrated impacted mandibular canine: report of case.


Nitrous oxide-oxygen sedation machines and devices. Council on Dental Materials and Devices, Council on Dental Therapeutics.


Acceptance program for dental materials and devices. Council on Dental Materials and Devices.


The secret of control.

The secret of control.


Comprehensive health education K-12--total preventive dentistry?


Care of the handicapped. II.

Care of the handicapped. II.


Acupuncture & dentistry.

Acupuncture & dentistry.


Diet counseling in your practice.

Diet counseling in your practice.


Fixed prostheses and blade implants.

Fixed prostheses and blade implants.


The New Jersey Dental School undergraduate program.


Sarcoidosis.

Sarcoidosis.


Fixed prosthesis without torque.

Fixed prosthesis without torque.


Dental health education via mobile trailer.


A comparison of two cytologic methods for mass screening against oral cancer.


Preventative periodontics.

Preventative periodontics.


Pulpal therapy for primary teeth.

Pulpal therapy for primary teeth.


Intramucosal inserts.

Intramucosal inserts.


What's your diagnosis, doctor? Osteitis of the right temporomandibular joint.


Editorial. Implantology: the state of the art.


We professionals can do more together.

We professionals can do more together.


Wegener's granulomatosis: current clinicopathologic concepts and oral differential diagnosis.


The diabetic dental patient: Part II. Diabetes and periodontal disease.


Antecedent-consequent variables of N2O-O2 administration in stage I analgesia.


Learning from your mistakes: a radiograph and a misdiagnosis.


The hygiene at fixed, rigidly connected saddles--a summary of the results of previous investigations.


Treatment of endangered pulp.

Treatment of endangered pulp.


A case of forced positional change (redressement forcé).


Hygienic aspects of dental practice management.


Structures of the bones of the jaw as seen with the scanning electron microscope. II. A series of illustrations from the collection of the Dental Clinic of the City Hospitals of Karlsruhe.


"Partial dentures"--and superstition. An observation on Thai patients.


The role of prevention in operative dentistry: a philosophical and practical approach.


Bleaching of pulpless teeth.

Bleaching of pulpless teeth.


Emergency endodontic treatment.

Emergency endodontic treatment.


The need for and use of community dental surveys.


Brief history of endodontics.

Brief history of endodontics.


A clinical application of practical photography for dentistry.


HL-A antigens and hematologic malignancy.


Complications of cytostatic therapy in childhood leukemia.


Androgens and human blood volume changes. Comparison in normal and various anemic states.


Histochemical study of acute leukemia.

Histochemical study of acute leukemia.


Report on drugs, narcotic and dangerous.


A mutuality of interest.

A mutuality of interest.


Centric relation records: the effect of muscle action.


Anteroposterior position of the mandible as related to centric relation registrations.


Versatile uses for alginate impression material.


A technique for determination of the occlusal plane.


A concept of preliminary treatments for successful restorative dentistry.


Microprobe analysis of an in vivo discoloration.


Tooth movement and repositioning of the mandible without appliances.


Endodontic access for metal veneered crowns for anterior teeth.


The load of the temporomandibular joint: physical calculations and analyses.


Effective management of laboratory procedures and use of split-cast technique.


Technique for duplicating a denture.

Technique for duplicating a denture.


Letter: Overlay dentures.

Letter: Overlay dentures.


Leukemic infiltration of the lungs in the chemotherapeutic era.


Gastric duplication.

Gastric duplication.


Treatment of Class 3 malocclusion with the Begg light-wire technique.


Tooth, face, and skull dimensions in different ethnic groups in Israel.


Photoelastic visualization of orthodontic forces during canine retraction.


Activators in orthodontic treatment: indications and advantages.


Force systems from an ideal arch.

Force systems from an ideal arch.


Research Council sets pattern for orthodontics' future.


Orthodontic tooth movement during an ascorbic acid deficiency.


Editorial: Constituent society presidents discuss issues facing orthodontics. II.


Electromyographic investigation of the buccinator mechanism.


The reliability of metallic implant and anatomic cephalometric superimposition techniques for the maxilla and mandible.


Timing of facial growth: a study of relations with stature and ossification in the hand around puberty.


Chronic granulocytic leukemia (CGL) during the course of chronic lymphocytic leukemia (CLL): correlation of blood, marrow, and spleen morphology and cytogenetics.


Juvenile "chronic granulocytic" leukemia: a panmyelopathy with prominent monocytic involvement and circulating monocyte colony-forming cells.


Cyclical granulopoiesis in chronic granulocytic leukemia: a simulation study.


Letter: Megakaryocytes in myeloproliferative disorders.


Proceedings: Hyponatraemia in acute myeloid leukaemia.


Models of sexual and natural selection in polygamous species.


Analysis of gene action in the control of body weight in the chicken.


Ecological genetics of a population of the snail Cepaea nemoralis at the northern limit of its range.


Assortative mating and artificial selection.


Polymorphisms for extra heterochromatin in Phaulacridium marginale.


Letter: Legislation--the solution to a dilemma.


Editorial: Improved cooperation between the oral surgeon and anesthesiologist.


JCAH and the hospital dentist.

JCAH and the hospital dentist.


An anesthetic technique utilizing Innovar, fentanyl, and methohexital sodium for outpatient oral surgery.


Case 5, Part 2, Osteoma cutis.

Case 5, Part 2, Osteoma cutis.


Superior orbital fissure syndrome: report of case.


Surgical treatment of ankylosis of the temporomandibular joint.


An improved splint in anterior osteotomies.


The basal cell nevus syndrome: report of two cases.


The reactivity of leukaemic cells to HL-A typing sera.


HL-A antigens and acute lymphocytic leukemia: the nature of the HL-A2 association.


Renal response to mechanical ventilation in patients with chronic hypercapnia.


Panel on race and poverty as considerations in the management of motor disability.


A philosophic preface to morals in medicine.


Poverty as a factor in the pathogenesis of motor disability: a two-year study on the inpatient rehabilitation service.


Some approaches to the problem of poverty as a factor in the pathogenesis of motor disability.


The first report of the National Commission on marihuana (1972): signal of misunderstanding or exercise in ambiguity.


The percentage of monocytes among "mononuclear" cell fractions obtained from normal human blood.


Editorial: Reciprocity--an ongoing affront.


Notes on prepayment. Council on Dental Care Programs.


The New York Dental Service Corporation--present status. A report.


Laboratory regulation--a reappraisal.

Laboratory regulation--a reappraisal.


Clinical significance of periodontic-orthodontic interrelationships.


Messenger RNA in eukaryotic cells: the life history of duck globin messenger RNA.


The translation of messenger RNA injected in living oocytes of Xenopus laevis.


Mitochondrial protein synthesis in HeLa cells.


Transcription of nonrepetitive DNA in human tissues.


Evidence for granulocytic incorporation of 67gallium in chronic granulocytic leukemia.


Editorial: Preleukaemic syndrome.

Editorial: Preleukaemic syndrome.


Hyponatraemia syndrome in acute myeloid leukaemia. Hyponatraemia was observed in 11 out of 14 consecutive patients with acute myeloid leukaemia and its variants. Metabolic studies on these patients revealed an early increase in the urinary sodium excretion, negative free water clearance, and urine osmolality inappropriately higher than that of the serum. It is postulated that this syndrome is caused by a substance released from the primitive cells of the abnormal myeloid series.


Epidemiology of long-term survival with acute leukemia.


Chronic cor pulmonale.

Chronic cor pulmonale.


Purification and properties of cytidine deaminase from normal and leukemic granulocytes. Cytidine deaminase, an enzyme that catalyses the deamination of both cytidine and its nucleoside analogues including the antineoplastic agents cytosine arabinoside (ara-C) and 5-azacytidine (5-azaC), has been partially purified from normal and leukemic human granulocytes. The purification procedure included heat precipitation at 70 degrees C, ammonium sulfate precipitation, calcium phosphate gel ion exchange, and Sephadex G-150 gel filtration. The enzyme has mol wt 51,000, isoelectric pH of 4.8, and maximum activity over a broad pH range of 5-9.5. The enzyme is stabilized by the presence of the sulfhydryl reagent, dithiothreitol. Cytidine deaminase from normal human granulocytes has a greater affinity for its physiologic substrate cytidine (K(m) = 1.1 x 10(-5) M) than for ara-C (8.8 x 10(-5) M) or 5-azaC (4.3 x 10(-4) M). Halogenated analogues such as 5-fluorocytidine and 5-bromo-2'-deoxycytidine also exhibited substrate activity, with maximum velocities greater than that of the physiologic substrates cytidine and deoxycytidine. No activity was observed with nucleotides or deoxynucleotides. The relative maximum velocity of the enzyme for cytidine and its nucleoside analogues remained constant during purification, indicating that a single enzyme was responsible for deamination of these substrates. Tetrahydrouridine (THU) was found to be a strong competitive inhibitor of partially purified deaminase with a K(i) of 5.4 x 10(-8) M. The biochemical properties of partially purified preparations of cytidine deaminase from normal and leukemic cells were compared with respect to isoelectric pH, molecular weight, and substrate and inhibitor kinetic parameters, and no differences were observed. However, normal circulating granulocytes contained a significantly greater concentration of cytidine deaminase (3.52+/-1.86 x 10(3)/mg protein) than chronic myelocytic leukemia (CML) cells (1.40+/-0.70 x 10(3) U/mg protein) or acute myelocytic leukemia (AML) cells (0.19+/-0.17 x 10(3) U/mg protein). To explain these differences in enzyme levels in leukemic versus normal cells, the changes in cytidine deaminase levels associated with maturation of normal granulocytes were studied in normal human bone marrow. Myeloid precursors obtained from bone marrow aspirates were separated into mature and immature fractions by Ficoll density centrifugation. Deaminase activity in lysates of mature granulocytes was 3.55-14.2 times greater than the activity found in the lysates of immature cells. Decreased enzyme activity was also found in immature myeloid cells from a patient with CML as compared to mature granulocytes from the same patient. These observations support the conclusion that the greater specific activity of cytidine deaminase in normal mature granulocytes as compared to leukemic cells is related to the process of granulocyte maturation rather than a specific enzymatic defect in leukemic cells.


Visual correction following cataract surgery.


Community determined diagnosis.

Community determined diagnosis.


Behavior modification with the severely mentally retarded.


Specific learning disabilities in children.


Infarcted omentum simulating acute appendicitis (report of three cases).


Extrinsic allergic alveolitis, (hypersensitivity pneumonitis) (case report).


Editorial: Some thoughts on sexuality.

Editorial: Some thoughts on sexuality.


Kanamycin dosage in renal failure.

Kanamycin dosage in renal failure.


Microembolism syndrome: acute respiratory failure and disseminated intravascular coagulation.


Idiopathic thrombocythaemia: a review of seven cases in Western Australia.


Ocular anomalies in Seckel's syndrome.

Ocular anomalies in Seckel's syndrome.


An experiment in continuing education for physicians.


Dental appointment with the sceptical Aymarás of Bolivia.


A comparison of monopolar and bipolar pulp-testing.


CDA up-dates fluoridation statistics.

CDA up-dates fluoridation statistics.


Antibiotic therapy for the practicing dentist.


Implications of the Combines Investigation Act.


1.5 million dollars MRC grant to U of T.


Advantages of a basic concept in lip reconstruction after tumour resection.


Results after midface-osteotomies.

Results after midface-osteotomies.


The conjunctival approach to the orbital floor and maxilla in congenital malformation and trauma.


Intra- and postoperative complications in surgical repair of clefts in infancy.


Speech development and maxillary growth in relation to technique and timing of palatoplasty.


Ameloblastic sarcoma in the maxilla--a case report.


Simianism: surgical-orthodontic correction of bimaxillary protrusion.


A program of general anesthesia for dental care of mentally retarded patients.


Control of the anxiety-pain complex in dentistry. Intravenous psychosedation with techniques using diazepam.


"Blade-vent" implant resulting in an oro-antral fistula. Report of a case.


Unusual complication associated with severe maxillofacial trauma.


Dental treatment and heart valve complications in narcotic addicts.


Congenital sublingual cystic swellings due to imperforate salivary ducts. Two case reports.


Giant-cell fibroma.

Giant-cell fibroma.


Cysticercosis of the maxillofacial region. A clinicopathologic study of five cases.


Nasopalatine duct cyst with pigmented lining suggestive of olfactory epithelium.


Median mandibular cyst--a rare lesion of debatable origin.


Biologic effect of dental materials. 6. Effects of isobutyl cyanoacrylate on HeLa cells in vitro.


Injection obturation in surgical endodontics.


A critical evaluation of some methods of determining tooth length.


Cirsoid aneurysm secondary to an arteriovenous fistula of the facial artery and vein.


Bilateral nasolabial cyst.

Bilateral nasolabial cyst.


Bilaterial fourth molar impactions.

Bilaterial fourth molar impactions.


Cytarabine for acute leukemia in adults. Effect of schedule on therapeutic response.


Chemotherapy of acute leukemia. Comparison of cytarabine alone and in combination with vincristine, prednisone, and cyclophosphamide.


Proceedings: Medullary extension of osteosarcoma. Implications for rational therapy.


The effect of surgery and posture on the pattern and rate of gastric emptying.


Proceedings: Splenectomy and chemotherapy in acute myelocytic leukemia of childhood.


Proceedings: Parenchymatous degeneration of the central nervous system in childhood leukemia.


Cytosine arabinoside and 6-thioguanine in refractory acute lymphocytic leukemia.


Proceedings: Daunorubicin cardiac toxicity in children with acute lymphocytic leukemia.


Demonstration of corrosion of dental alloys.


Editorial: The Annual Session.

Editorial: The Annual Session.


Report of the Special Committee to review annual session format.


Otolaryngologic manifestations of acute leukemia.


A contribution to the surgical treatment of open bite.


Some determinants of the therapeutic efficacy of actinomycin D (NSC-3053), adriamycin (NSC-123127), and daunorubicin (NSC-83142).


Pulp vitality of multirooted teeth after injury to one root.


In vitro studies on lines of osteotomy in the pterygoid region.


Comparative investigation on the classification of carcinoma of the oral cavity.


Experiences with intraoral trans-osseous wiring of mandibular fractures.


Malformations of the ear in cleft palate patients.


Adverse haematological effects and trimethoprim-sulphamethoxazole administration.


Salmonella cubana infection.

Salmonella cubana infection.


Identification of the high risk pregnancy by a scoring system.


Editorial: Pollution in the operating theatre.


Letter: Upper and lower respiratory infections in children.


A case of acute myelomonocytic leukaemia associated with myelomatosis.


Analysis of the electrophoretic pattern of mycoplasma proteins for the identification of canine mycoplasma strains.


The potency of BCG vaccine determined by the tuberculin shock method on hamsters.


Passive hemagglutination test, using erythrocytes sensitized with Klebsiella type specific polysaccharides.


Leukemic cell proliferation and maturation in vivo.


Rabbit anti rat lymphocyte serum: in vitro activity towards macrophages in monolayer.


Clinical trials of the acute leukemia group B in acute lymphocytic leukemia of childhood.


Rationale and results of combination chemotherapy and central nervous system irradiation in acute lymphocytic leukemia.


Combination therapy involving L-asparaginase in acute leukemia.


Treatment of acute myeloblastic leukemia.


Pharmacologic and cytokinetic studies of arabinosyl cytosine.


Epidemiological observations of human leukemia in a metropolitan area.


New results of active immunotherapy of acute lymphoid leukaemia.


Combined chemotherapy of acute myeloblastic leukemia.


Transplantation of radiation-induced canine myelomonocytic leukemia.


Myelogenous leukemia and related myeloproliferative disorders in beagles continuously exposed to 60Co gamma-radiation.


Eventual control of clinical leukemia.

Eventual control of clinical leukemia.


Abnormal regulation of granulopoiesis in human acute granulocytic leukemia.


Cellular cytotoxicity reactions to human leukemia associated antigens.


Leukaemic stem cell kinetics in experimental animals.


Human macellaria myiasis in Puerto Rico.


The toxicology of aspirin.

The toxicology of aspirin.


Effectiveness of minocyline in bacterial infection.


Acute trifascicular block. A report of four cases and a review of the literature.


Hyperlipoproteinemic types among Puerto Ricans: a progress report.


Prevention of complicating emotional problems of the paraplegic.


Takayasu's arteritis in pregnancy.

Takayasu's arteritis in pregnancy.


Comparison of two vectorcardiographic leadsystems (Burger and Frank).


The non-equivalence of mouse and human marrow culture in the assay of granulopoietic stimulatory factors.


Different sensitivity to actinomycin D of biopsies of human tumors cultivated in vitro.


Physician's bill of rights.

Physician's bill of rights.


Tic del Gilles de la Tourette: case report and brief discussion.


A psychologist looks at the smoking habit and how to stop it.


Effective use of the static brain scan.

Effective use of the static brain scan.


The diagnosis and treatment of vitamin B12 deficiency in young lambs.


An investigation of ewe to lamb transfer of the itch mite Psorergates ovis.


Letter: Copper and molybdenum imbalance in relationship to post-parturient haemoglobinuria in cattle.


An introduction to principles of veterinary clinical pharmacology: the absorption of drugs.


Hypocuprosis: a clinical investigation of dairy herds in Northland.


Practical screening for diabetes mellitus in pregnant women.


Clinical classification and evaluation of treatment response in acute myeloid leukaemia on the basis of differences of leukaemic cell differentiation.


Serum progesterone in diabetic pregnancy.


Human chorionic somatomammotropin in diabetic pregnancies.


Serum levels of human chorionic somatomammotropin (HCS) in normal and abnormal pregnancies.


Urinary oestriol excretion in diabetic pregnancy. The problem of reference intervals.


The transverse diameter of the pelvic inlet in diabetic women in relation to age at onset of diabetes.


Hemoglobin F in newborn infants of diabetic mothers.


Oestriol excretion in pregnant diabetics related to long-term prognosis of surviving children.


Contraception in diabetic patients.

Contraception in diabetic patients.


Dental students, then and now.

Dental students, then and now.


Atypical megakaryocytes in preleukemic phase of acute myeloid leukemia.


Delta Dental Plans special relationship with the profession.


Letter: Trichinosis in the U.S.

Letter: Trichinosis in the U.S.


On national licensure.

On national licensure.


Importance of nutrition.

Importance of nutrition.


Letter: milk and fluoridation.

Letter: milk and fluoridation.


Letter: USA dental plans.

Letter: USA dental plans.


Standards for dental prepayment programs. Council on Dental Care Programs.


Pit and fissure sealants: one-year results from a study in Kalispell, Montana.


Progress report on the effect of a fissure sealant on bacteria in dental caries.


Recurrent severe facial emphysema in a submariner.


Degradation of dental radiographic processing solutions.


Abnormal bone repair in jaws, socket sclerosis: a sign of systemic disease.


In vivo alterations in enamel from zinc phosphate cement containing stannous fluoride.


Modification of an endodontic film holder.


Occlusion and preventive dentistry.

Occlusion and preventive dentistry.


The solution of a battered-child homicide by dental evidence: report of case.


Endodontic pain referred across the midline: report of case.


Pulpitis simulating the myofascial pain dysfunction syndrome: report of three cases.


Inventory of dentists--1973. Bureau of Economic Research and Statistics.


Japanese Division of the International Association for Dental Research--Abstracts of papers presented at the Twentieth Annual Meeting.


Awards offered by the IADR.

Awards offered by the IADR.


A micromethod for determination of antibiotic concentrations in body fluids.


Experimental study of surface and lattice effects on the solubility of hydroxyapatite.


Experience with gentamicin in respiratory tract infections caused by gram-negative rods.


Reflections on the clinical pharmacology of gentamicin.


Gentamicin therapy administered by intermittent intravenous injections.


Scandinavian Division of the International Association for Dental Research--Absttracts of Papers presented at the Annual Meeting.


President-Elect's Message: Challenge for tomorrow.


Effect of gentamicin on mycobacteria in vitro.


Gentamicin therapy of severe infections.


The use of gentamicin intravenously.

The use of gentamicin intravenously.


Effect of occlusal trauma on interstitial pressure in the periodontal ligament.


Hearing loss and cochlear pathology in gentamicin intoxicated guinea pigs.


Treatment with gentamicin. Application and therapeutic effect.


Concentration of gentamicin in serum, urine and urogenital tissue in man.


Methicillin-resistant staphylococci as an epidemiological indication for gentamicin therapy.


Renal excretion of gentamicin and effect of probenecid.


North Carolina gains in health manpower production.


Gilles de la Tourette's syndrome following methylphenidate administration.


Impotence as a symptom of depression.

Impotence as a symptom of depression.


School policies for first aid.

School policies for first aid.


Dr. Jerome L. Reeves on "milk sick". An interview.


Lungs and automatic ventilation. 2. Types of ventilation.


A trip with a Bennett.

A trip with a Bennett.


Factors contributing to future rise of blood pressure.


Mechanism of the heterotopic calcification induced by subcutaneous injection of lead acetate.


Inhibition of bone growth by sodium salicylate.


Effect of viscosity on the accuracy and stability of elastic impression material.


Elasticity of elastomer impression materials. I. Measurement of Young's modulus of elasticity and of the coefficient of elasticity.


Free amino acids in human saliva.

Free amino acids in human saliva.


Target tissue pressure in 3 water jet devices.


Fluoride acquisition in vitro by etched enamel from acidulated phosphate-fluoride preparations.


Effect of biting force on the duration of the masseteric silent period.


Interrelationships and sex differences of dental and skeletal measurements.


Trials of 3 organic phosphorus-containing compounds as protective agents against dental caries in rats.


Improvement in abrasive biopsy sampling of tooth enamel.


Dentinogenesis in incisord of rats deficient in essential fatty acids.


Effect of addition of Cafpo3 to a zinc oxide-eugenol base liner on the michrohardeness and fluoride content of dentin.


Comparison of rheological properties of four dental restorative materials.


Caries prevention in deciduous dentition using table salt fluoridation.


Tensile strength distribution study of a dental restorative material.


Relation of arsenic supplements to dental caries and the periodontal syndrome in experimental rodents.


Ovarian liposarcoma. A case report.

Ovarian liposarcoma. A case report.


Role of attrition and occlusal contact in the physiology of the rat incisor. VII. Formation of impeded and unimpeded incisors in magnesium-deficient rats.


Psychiatric peculiarities of the young adult.


Influence of age and duration of diabetes on dental development in diabetic children.


Desquamative interstitial pneumonia. A systemic disease and precancerous lesion?


Scanning electron microscope studies of dextranase-treated plaque streptococci.


Growth of the tooth germ in new born rats exposed to oxygen at atmospheric and high pressure.


Some effects of breakfast cereals on caries in rats.


Hair crystallinity and its relation to drug use.


Foreign bodies in incisors of mice.

Foreign bodies in incisors of mice.


Penicillium infection in man.

Penicillium infection in man.


Gas gangrene after abdominal surgery. A report of three cases.


Malalignment of teeth in different human ethnic groups.


Incisor fluorosis in mice fed fish protein concentrate.


Effect of fluoride pretreatment or rehardening with calcifying solutions on enamel softened by orange juice.


Science in medicine: the complications of success.


Gasserian ganglion injection for trigeminal neuralgia.


Radiologic diagnosis of urinary tract injuries following gynecologic surgery.


Letter: "Digitalis cachexia".

Letter: "Digitalis cachexia".


Correlative study of the physiologic and morphologic characteristics of the temporal and masseter muscles of the cat.


Effect of saliva on oral chemical carcinogenesis.


Immunosuppressive treatment to enhance spinal cord regeneration in rats.


Further observations on cardiac rehabilitation.


Dental growth fields and premolar morphology.


Quantitation of human dental plaque by turbidimetry.


The GP's task: educational objectives.

The GP's task: educational objectives.


Radiography of fossilized dentaries of Tyrannosaurus rex.


Peroxidase localization in von Ebner's gland of man.


Editorial: WHO in the Western Pacific Region.


Phencyclidine-induced anesthesia for dental procedures in the baboon.


Editorial: Vasectomy.

Editorial: Vasectomy.


Letter: Anaemia in Polynesian infants.

Letter: Anaemia in Polynesian infants.


Letter: Rabies vaccine.

Letter: Rabies vaccine.


Letter: Tricyclic antidepressants: dangers with overdosage.


Origin of the Philadelphia chromosome. Tracing of chromosome 22 to parents of patients with chronic myelocytic leukemia.


Primary medical care and group practice in North Carolina.


Carolinas' camp for diabetic children. II. Descriptive features of a camper population with emphasis on complications.


Significance of enamel remineralization.


Initial care for lacerations of flexor tendons of the hand.


Some analytical ultramicro-techniques.

Some analytical ultramicro-techniques.


An outline of the basic electrochemistry of porous membranes.


Characterization of ion transport properties of enamel and plaque.


Physicochemical mechanisms of dental caries.


Microbes and their products in plaque.

Microbes and their products in plaque.


Ultrastructure of carious lesions.

Ultrastructure of carious lesions.


Physicochemistry of demineralization and remineralization.


Salivary products in plaque and saliva.

Salivary products in plaque and saliva.


Crystal-chemical considerations.

Crystal-chemical considerations.


The tail is wagging the dog.

The tail is wagging the dog.


Letter: Recommendation for DTP.

Letter: Recommendation for DTP.


A community of care.

A community of care.


[Letter: A matter of discretion].

[Letter: A matter of discretion].


Medical and surgical complications of therapeutic termination of pregnancy.


Letter: Treatment and drug addiction.

Letter: Treatment and drug addiction.


Editorial: The health and hospital corporation debacle.


Editorial: Bill of Rights for the doctor: without consent or due process, it is rape.


Pregnancies of methadone patients. Findings in New York City Methadone Maintenance Treatment Program.


Providing incentives to successful methadone patients: experimental program.


Effect of fiberoptic bronchoscopy on arterial oxygen tension.


Hospital dependency: popular but specious concept.


Evaluation of suicidal patients.

Evaluation of suicidal patients.


Rapid and gentle pharmacotherapy of depression.


Serum cholesterol in ambulatory patients: relationship to age, sex, diabetes, and myocardial infarction.


Neglected rupture of bilateral patellar ligaments.


Mediastinal hematoma: complication of subclavian vein catheterization.


Bilateral absence of breasts.

Bilateral absence of breasts.


Nephrotic syndrome in drug addicts.

Nephrotic syndrome in drug addicts.


Electrocardiograms of the month.

Electrocardiograms of the month.


Organization and delivery of public medical care services in New York City.


The efficiency of a new aspirating system.


The respirability of aerosols produced in dentistry.


Lateral tongue spreading.

Lateral tongue spreading.


A modification of the acid-etching technique for restoring fractured incisors.


An evaluation of Progold.

An evaluation of Progold.


Lungs and automatic ventilation. 3. The patient on the ventilator.


Symposium on toxoplasmosis. Introduction.


Toxoplasmosis in pregnancy and its transmission to the fetus.


Manifestations and management of ocular toxoplasmosis.


Breaking the transmission chain of Toxoplasma: a program for the prevention of human toxoplasmosis.


Discussion of paper by J.K. Frenkel, M.D., Ph. D.: breaking the transmission chain of Toxoplasma: a program for the prevention of human toxoplasmosis.


Multi-faceted James Granberry D.D.S.

Multi-faceted James Granberry D.D.S.


Flow requirements for a modified Mapleson D system during controlled ventilation.


Teeth and tetracyclines.

Teeth and tetracyclines.


Occupational health case report--no. 1.

Occupational health case report--no. 1.


Cardiovascular genetic immunopathies.

Cardiovascular genetic immunopathies.


Indications for coronary arteriography and myocardial revascularization procedures.


A physical fitness and cardiovascular risk factor screening program for State Legislators.


Radiographic diagnosis of aortic coarctation.


Alteration of diet habits in children.

Alteration of diet habits in children.


Psychological aspects of intensive care units.


President's message: Communication.

President's message: Communication.


Continuous infusion of diazepam in infants with severe recurrent convulsions.


Actinomycosis arthritis: a case report.

Actinomycosis arthritis: a case report.


The use of immunosuppressive agents in Takayasu's arteritis.


Editorial: The dangerous sex offender.

Editorial: The dangerous sex offender.


A non-endotracheal airway for surgery of the head in outpatients.


Acute leukaemia in pregnancy with placental involvement.


Reflex adrenergic inhibition of gastric motility elicited from the gastric antrum.


The assessment of small-for-dates infants and associated sociobiological factors.


Clinical nutrition. Requirements of energy and nutrients in diseases.


Leukemia and the somatic risks of chemical mutagens.


Editorial: Let's get a decision.

Editorial: Let's get a decision.


Water hardness and teeth.

Water hardness and teeth.


Dosage and premedicating drugs.

Dosage and premedicating drugs.


Tetracycline staining.

Tetracycline staining.


Letter: Medi-Cal patients.

Letter: Medi-Cal patients.


Letter: The DMD vs DDS situation.

Letter: The DMD vs DDS situation.


Letter: Seeks some answers.

Letter: Seeks some answers.


Letter: On professional liability.

Letter: On professional liability.


Peer review: building a network. Council on Dental Care Programs.


Collagen and periodontal disease: report from the annual AAAS meeting.


Mercury vapor exposure in a dental school environment.


Children's incremental dental care program: an overview of the southeast Tennessee-northwest Georgia project.


A two-, three-, and four-year follow-up of a clinical study of the effect of trituration on amalgam restorations.


The prediction of the size of unerupted canines and premolars in a contemporary orthodontic population.


Alveolar osteitis associated with mandibular third molar extractions.


Comparison of common root canal filling techniques and sealers with the simplified pressure injection method and zinc oxide-eugenol as the sealing agent.


A superior desensitizer--potassium nitrate.


An unusual fracture of the central incisor: report of case.


Mycotic infections associated with complete dentures: report of three cases.


Letter: Virus-like particles in human leukemic cells.


Extraosseous osteogenic sarcoma of forearm.


The Nursing Council.

The Nursing Council.


Searching for facts.

Searching for facts.


Counselling service.

Counselling service.


Depression. How to recognize it.

Depression. How to recognize it.


Some relations between optometry and psychology.


Peripheral and central components in the formation of visual illusions.


Changes in the cornea following removal of the epithelium.


The measurement and stability of hydrophilic lens dimensions.


Differential diagnosis of optic nerve pathology and its anomalies.


Conjunctival absorption of pigment from eye makeup.


A new content emphasis for a public health class for optometric students.


Validity of selected academic and non-academic predictors of optometry grades.


Previous and simultaneous cancers in patients with leukemia.


Redox potentials of certain vitamins K: implications for a role in sulfite reduction by obligately anaerobic bacteria. Redox potentials of a menaquinone (MK-6), isolated in earlier researches from two species of the obligately anaerobic genus, Desulfovibrio, as well as two other vitamins K(2)-menaquinones (MK-5) and (MK-9)- have been determined polarographically. The measurements have been validated by determination of redox potentials of 1,4-naphthoquinone and vitamin K(1) which agree with published potentiometric values. E(m7) for menaquinone (MK-6) is -0.067 +/- 0.010 V. Redox potentials calculated for terminal acceptor couples currently proposed in the mechanisms of sulfate reduction by Desulfovibrio are consistent with the involvement of menaquinone (MK-6) in at least one of the steps postulated during electron transfer with ultimate production of sulfide.


Long-range, pH-dependent effects on the carbon-13 nuclear magnetic resonance spectra of oxytocin. The effects of hydrogen ion concentrations on the carbon-13 nuclear magnetic resonance spectra of oxytocin were investigated. The starting pD of 3.0 was increased stepwise to 8.4. A change of the state of protonation of the N-terminal amino group of oxytocin is accompanied by changes in chemical shifts of carbon-13 nuclei of amino-acid residues located in the 20-membered ring of the hormone. The resonance positions of the acyclic peptide portion, Pro-Leu-Gly-NH(2), remain constant. The pD-induced chemical-shift changes of carbons up to five bonds removed from the site of protonation are interpreted in terms of "through-bond" and "through-space" mechanisms. Chemical-shift changes of carbons more than five bonds removed are proposed to have a conformational origin. It is suggested that a change in the charge density of the amino group perturbs the dihedral angle of the -CH(2)-S-S-CH(2)- moiety of oxytocin, which in turn significantly affects the overall conformation of the 20-membered ring of the hormone.


The site of force generation in muscle contraction as deduced from fluorescence polarization studies. The fluorescent dye, N(-iodoacetylamino)-l-naphthylanine-5-sulfonic acid, labeled exclusively the myosin cross-bridges in rabbit glycerinated psoas muscle fibers, without impairing their function. Fluorescence polarization was used to study cross-bridge orientation in rigor, relaxation, and contraction, as a function of sarcomere length. At a length where no overlap between thick and thin filaments occurs, rigor-inducing, relaxation-inducing, and contraction-inducing solutions all induced the relaxation attitude. At lengths where overlap does exist, the slowly-hydrolyzing ATP analog, "alpha,beta-methylene ATP," induced the relaxation attitude. The data were consistent with the A. F. Huxley-Simmons model of force generation. Combined with our earlier results, the data indicated that torque was generated at the actin-myosin interface.


Repression by hematin of porphyrin biosynthesis in erythrocyte precursors in congenital erythropoietic porphyria. Hematin administered intravenously in a patient with congenital erythropoietic porphyria evidently entered erythrocyte precursors in the bone marrow, producing the well-known negative feedback repression of porphyrin biosynthesis with marked decline of porphyrin concentrations in urine, circulating plasma, and erythrocytes. A delay in the major segment of this effect corresponded roughly with the sum of the average transit times through the maturation compartments of the erythrocyte precursors. This delay was considerably longer than previously observed in the decline of porphyrin precursors after administration of hematin in patients with hepatic porphyria. The effect of hematin was compared with that of packed erythrocyte transfusions given at regular intervals in the same patient over a period of 2.5 years. In general, administration of hematin results in a reduction of porphyrin formation of the same order of magnitude, but of shorter duration, possibly in relation to the relatively small amounts of hematin infused.


A proposed model for interaction of polypeptides with RNA. Pairs of antiparallel beta polypeptide-chain segments in known protein structures are usually observed to form right-handed double helixes with helix parameters in the same range as those of nucleic acids. We have constructed a model containing only standard bond lengths, bond angles, and dihedral angles in which such a polypeptide double helix fits precisely into the minor groove of an RNA double helix with identical helix parameters. The geometry of the RNA portion is essentially a hybrid between those of the A and A' forms. Hydrogen bonds can be made between the ribose 2'-hydroxyls and polypeptide carbonyl oxygens. Since such precise complementarity between the stable conformations of RNA and polypeptides is unlikely to be merely coincidental, we propose that it played a fundamental role in the initiation of precellular evolution. Specificially, we propose that the two double-helical structures are mutually catalytic for assembly of one another from activated precursors in the prebiotic soup, and moreover that they provide some degree of genetic coding.


Trinitrophenol: a membrane-impermeable uncoupler of oxidative phosphorylation. Picrate (trinitrophenol) is a unique uncoupler of oxidative phosphorylation. Unlike the commonly used uncouplers (e.g., 2,4-dinitrophenol, pentachlorophenol, m-chlorocarbonylcyanide phenylhydrazone, and 5-chloro-3-t-butyl-2'-chloro-4'-nitrosalicylanilide), picrate seems to penetrate the mitochondrial inner membrane very slowly. Consequently, it is ineffective when added to intact mitochondria or to mitochondria depleted of their outer membranes. In contrast, when added to phosphorylating submitochondrial particles prepared by sonication in which the inner membrane orientation is inside-out, picrate binds to the uncoupler-binding sites and uncouples oxidative phosphorylation. This unique property of picrate has made it possible to compare the potencies of picrate and dinitrophenol for (a) uncoupling and (b) increasing the proton permeability of submitochondrial particle vesicles. At 50% uncoupling concentration, dinitrophenol increased the proton permeability of submitochondrial particle vesicles by 9- to 12-fold. In contrast, at 100% uncoupling concentrations or higher, picrate augmented the proton permeability of the particles by only about 3-fold. These results indicate that facilitation of transmembrane proton equilibration does not determine the degree of uncoupling, and lead to the corollary conclusion that the magnitude of transmembrane proton gradient need not be the quantitative driving force for ATP synthesis.


A peculiar substructure in the postsynaptic membrane of Torpedo electroplax. Freeze-etching of Torpedo marmorata electroplax reveals an unusual substructure in one of the fracture faces of the postsynaptic membrane. This substructure consists of a lattice of closely spaced particles that are smaller than the usual 80- to 90-A particles present in other membrane types. The lattice occurs exclusively on the B-face of the postsynaptic membrane.


Tandem duplication in bacteriophage P2: electron microscopic mapping. The physical position of vir37, a new immunity-insensitive mutant of Escherichia coli bacteriophage P2, was mapped by the electron microscopic heteroduplex method. In P2 vir37, a segment equivalent to 2.8% of P2 DNA is added. The addition was characterized as a tandem duplication of the segment occurring between 77.2 and 80.0% from the left end of P2 DNA (the right half of P2 DNA is arbitrarily defined, from denaturation map studies, as the half richer in A + T). The point of addition of the duplicated segment (the "novel-joint") was, thus, 80.0% from the left end of P2 DNA. On the basis of previous studies on P2 vir22, it was tentatively concluded that the physical and genetic maps of P2 are colinear. This conclusion is now further supported by physical and genetic data on P2 vir37.


Constitutive expression of bacteriophage P2 early genes resulting from a tandem duplication. A tandem-duplication mutant of bacteriophage P2 was isolated. Physically, its particles are characterized by a higher buoyant density and lower heat stability than the wild type, both consequences of increased DNA content. Genetically, the mutant is easily recognized by its insensitivity to control by the immunity-specific repressor. The duplication covers part of gene B, necessary for phage DNA replication. To explain the immunity-insensitivity of the duplication it is proposed that the promoter, but not the operator site, in the early gene operon is duplicated in this mutant. By crosses with a gene-B mutant, a recombinant carrying a heterozygous duplication was isolated.


Isolation and structure of two prostaglandin endoperoxides that cause platelet aggregation. Incubation for a short time of arachidonic acid with the microsomal fraction of a homogenate of the vesicular gland of sheep in the presence of 1 mM p-mercuribenzoate followed by extraction and silicic acid chromatography yielded two prostaglandin endoperoxides. The structures of these compounds, i.e., 15-hydroperoxy-9alpha,11alpha-peroxidoprosta-5,13-dienoic acid (prostaglandin G(2)) and 15-hydroxy-9alpha,11alpha-peroxidoprosta-5,13-dienoic acid (prostaglandin H(2)), were assigned mainly by a number of chemical transformations into previously known prostaglandins. The new prostaglandins were 50-200 times (prostaglandin G(2)) and 100-450 times (prostaglandin H(2)) more active than prostaglandin E(2) on the superfused aorta strip. The half-life of the prostaglandin endoperoxides in aqueous medium (about 5 min) was significantly longer than that of "rabbit aorta-contracting substance" released from guinea pig lung, indicating that none of the prostaglandin endoperoxides is identical with this factor. Addition of 10-300 ng/ml of the endoperoxides to suspensions of washed human platelets resulted in rapid aggregation. Furthermore, platelet aggregation induced by thrombin was accompanied by release of material reducible by stannous chloride into prostaglandin F(2alpha), thus indicating the involvement of endogenous prostaglandin endoperoxides in platelet aggregation.


A kinase that transfers the gamma-phosphoryl group of GTP to proteins of eukaryotic 40S ribosomal subunits. An enzyme in rat-liver cytosol transferred the gamma-phosphoryl of GTP to serine and threonine residues of at least four proteins (S6, S10, S14 or S15, and S17) of the small (40S) subunit of rat-liver ribosomes. A number of nonribosomal proteins in the enzyme preparation were also phosphorylated; they were preferentially and tightly bound to the large subunit. The enzyme could be distinguished from protein kinase-ATP (which also phosphorylated ribosomal proteins) by a number of criteria: (1) GTP was the phosphoryl donor; (2) the pattern of phosphorylation of ribosomal proteins by the two enzymes was different; and (3) the protein kinase that used GTP as the phosphoryl donor was not stimulated by cyclic AMP (or by cyclic GMP).


Differential interaction of cholesterol with phosphatidylcholine on the inner and outer surfaces of lipid bilayer vesicles. The separate identification of the -N(+)-(CH(3))(3) groups located on the outside and inside of phospholipid bilayers observed in proton magnetic resonance spectroscopy upon addition of low concentrations of praseodymium ion was exploited to investigate the effects of incorporated cholesterol. Only about 7% of the phosphate groups on the outside of the bilayer belong to a class of strong binding or shifting sites. Upon addition of up to about 30% cholesterol to egg lecithin bilayers, no changes in chemical shift or ratio of areas of peaks due to outer and inner -N(+)(CH(3))(3) groups appear. At about 30% incorporated cholesterol, an abrupt decrease occurs in the chemical-shift difference between -N(+)(CH(3))(3) groups located on the outer and inner bilayer surfaces, and an abrupt increase occurs in the ratio of the areas of the two peaks. For L-alpha-dipalmitoyl lecithin bilayers, an abrupt change in chemical-shift difference occurring between 10 and 20% cholesterol is not accompanied by a change in the relative number of -N(+)(CH(3))(3) groups located on the outer and inner surfaces. These results are interpreted as due to the homogeneous distribution of up to 30% cholesterol in egg lecithin bilayers. Above 30%, cholesterol is asymmetrically distributed in favor of the inner layer. In egg lecithin with a variety of polyunsaturated side chains, the side chains with the greater number of double bonds are preferentially displaced by high concentrations of cholesterol, which accounts for the increase in the ratio of outer to inner -N(+)(CH(3))(3) groups. Such preferential displacement by cholesterol cannot occur with the saturated L-alpha-dipalmitoyl lecithin. It is suggested that modified phospholipid vesicles of low radii of curvature may provide high concentrations of "active sites" present in membranes.


The amino-acid sequence of the amino-terminal 37 residues of human parathyroid hormone. The sequence of the amino-terminal 37 residues of human parathyroid hormone has been established. The hormone used in these studies was isolated in highly purified form from parathyroid adenomata and was subjected to automated degradation in a Beckman sequencer. A high-sensitivity sequencing procedure employing (35)S-labeled phenylisothiocyanate of high specific activity as the coupling agent was used. The sequence obtained differs from that of bovine parathyroid hormone in three of the first 37 positions, and from that of porcine parathyroid hormone in two positions. A single human-specific residue was found (asparagine 16). The sequence obtained differs at three positions (22, 28, and 30) from the structure for human parathyroid hormone reported recently by Brewer et al. [(1972) Proc. Nat. Acad. Sci. USA 69, 3585-3588] and synthesized by Andreatta et al. [(1973) Helv. Chim. Acta, 56, 470-473] We have carefully reviewed our data, reported here in detail, on the sequence positions in dispute. We must conclude, on the basis of all available data, that the structure that we propose is the correct structure. The objective resolution of these discrepancies in structural analysis through further chemical and immunochemical studies is important, since synthesis of human parathyroid hormone, in which there is widespread interest for physiological and clinical studies, must be based on the correct sequence of the human hormone if the peptide is to be genuinely useful.


Magnetic circular dichroism studies. XXV. A preliminary investigation of microsomal cytochromes. The application of magnetic circular dichroism as an optical probe for simultaneous identification and determination of at least two microsomal cytochromes is demonstrated. The assignments of the bands in the spectra of microsomal suspensions are made from the spectra of soluble preparations of cytochrome P-450 obtained from Pseudomonas putida and of cytochrome b(5) obtained from rat livers.


Effects of phagocytosis and colchicine on the distribution of lectin-binding sites on cell surfaces. The effect of phagocytosis on lectin binding to plasma membranes of polymorphonuclear leukocytes was examined. The specific activities of binding sites of concanavalin A and Ricinus communis agglutinin (defined as mug of lectin bound per 100 mug of membrane protein) were measured on isolated membranes; they decreased in parallel with phagocytosis. Our data suggest that this removal occurs by concentration of binding sites into internalized membrane. Colchicine and vinblastine, which did not inhibit phagocytosis, prevented the selective removal of lectin-binding sites from the surface. It was also shown that at 37 degrees lectins induce their own internalization. This property was used to define operationally three classes of lectin receptors, one of which is most extensively removed from plasma membrane during phagocytosis. Based on other morphological studies in which it is shown that before phagocytosis the surface distribution of concanavalin-binding sites is random, it is inferred that phagocytosis alters surface topography by inducing the selective movement of binding sites into membrane undergoing internalization and that colchicine-sensitive proteins are essential for this imposed topographical reorganization.


Chromosome assignment of the human gene for galactose-1-phosphate uridyltransferase. Somatic cell hybrids formed between galactose-negative mutant Chinese hamster cells and human lymphocytes were selected in galactose medium and analyzed for the concurrent presence of specific human chromosome(s) and human galactose-1-phosphate uridyltransferase. In one of the hybrid clones only a single human chromosome, A2, was consistently present when the hybrid cells were maintained in the selective medium, suggesting that the location of the structural gene for galactose-1-phosphate uridyltransferase is on this chromosome. Among subclones derived from this cell hybrid in the absence of selection, a complete concordance was demonstrated between the ability or inability to utilize galactose and the concomitant presence or absence of the human transferase and the A2 chromosome.


Transfer RNA biosynthesis: the nucleotide sequence of a precursor to serine and proline transfer RNAs. The nucleotide sequence of a transfer RNA precursor molecule coded by bacteriophage T4 has been determined. The molecule is a single polynucleotide chain which contains two transfer RNA species that are destined to recognize serine and proline. The 3' -CCA(OH) termini of both mature transfer RNA species are absent in the precursor molecule; these termini must therefore be added enzymatically at a subsequent stage of maturation. Nucleotide residues unique to the precursor are located at both ends of the molecule and between the two transfer RNA sequences.


Conversion of protein nitrogen into gaseous catabolites by the chick embryo. Chicken eggs incubated under hatchery conditions for 19 days show significant decreases in the total content of water and organic nitrogen, but not of sodium or potassium. The hypothesis is discussed that the formation of gaseous nitrogen is responsible for the nitrogen loss.


Formation in vitro of infective joint molecules of lambda DNA by T4 gene-32 protein. Half molecules of lambda DNA that had been partially digested by lambda exonuclease to expose homologous single strands were rejoined by the action of T4 gene-32 protein at 37 degrees in the presence of Mg(++). Measurements of infectivity in su(-) spheroplasts and sedimentation in sucrose demonstrated the formation of sus(+) joint molecules from two preparations of sheared lambda DNA that carried sus mutations at opposite ends of the genome. The biological activity of joint molecules made by annealing at 75 degrees was diminished by the addition of the gene-32 protein in the absence of Mg(++), and largely restored by the subsequent addition of Mg(++). The specific infectivity of joint molecules made by gene-32 protein at 37 degrees was similar to that of joint molecules made by annealing at 75 degrees . The experimental system described provides a possible model for simulating early steps in genetic recombination.


Two eukaryotic initiation factors (IF-I and IF-II) of protein synthesis that are required to form an initiation complex with rabbit reticulocyte ribosomes. The formation of an initiation complex with rabbit reticulocyte ribosomes and certain templates is dependent upon the action of two initiation factors (IF-I and IF-II) of protein synthesis isolated from 0.5 M KCl extracts of rabbit reticulocyte polysomes. IF-I mediates the GTP-dependent, but template-independent, binding of the cytoplasmic initiator transfer RNA (rabbit liver) to a 40S ribosomal subunit. In the presence of a 60S ribosomal subunit and of AUG, AUG(U)(25), or rabbit-globin messenger ribonucleoproteins (but not of rabbit-globin messenger RNAs), IF-II causes the transfer of the initiator transfer RNA to an initiation complex containing an 80S ribosome. Although 5'-guanylylmethylenediphosphonate can replace GTP as the cofactor used in binding the initiator transfer RNA to IF-I or to a 40S ribosomal subunit, the subsequent transfer of the initiator transfer RNA to an initiation complex requires GTP and cannot take place in the presence of 5'-guanylylmethylenediphosphonate. After the formation of this initiation complex, the initiator transfer RNA is bound in the P site of the 80S ribosome since exposure of the complex to puromycin releases the methionine residue from the initiator transfer RNA as methionyl-puromycin.IF-I and IF-II are dissociated from polysomes by 0.5 M KCl as a complex having a molecular weight of about 370,000, and they remain in this form during and after gel filtration. However, the two factors can be separated by appropriate step elutions from DEAE-cellulose. After separation of the two activities, the molecular weights of IF-I and IF-II are about 150,000 and 220,000, respectively.


Interaction of mycoplasmas with cell cultures, as visualized by electron microscopy. Mycoplasmas were examined on the surfaces of tissue culture cells prepared for transmission and scanning electron microscopy. The pleomorphic bodies seen were proved to be mycoplasmas by the use of thin sections, passage of the infection from one cell line to another, and by autoradiography with [(3)H]thymidine both on the sections and the replicas. The mycoplasmas were not always evenly distributed over the cell's surface; their arrangement seemed to correlate with the activity or morphology of the cell. The use of replicas and scanning electron microscopy in routine examination of cultures for mycoplasma contamination is discussed.


Quasilinkage equilibrium and the evolution of two-locus systems. In terms of intrinsic variables of the system, short, intermediate, transitional, and long (or asymptotic) times are defined for the evolution of a two-locus model with linkage and epistasis. It is argued that, during the first two and last periods, all quantities of genetic interest, such as the gametic frequencies, the mean fitness, the linkage disequilibrium, and the linkage disequilibrium ratio, Z, change with time in essentially the same manner, characteristic of the particular epoch concerned and determined in this paper, and therefore, when quasilinkage equilibrium occurs, it is a transitional phenomenon. Both continuous random births and deaths and discrete, nonoverlapping generations are considered.


On the very rapid enhancement by D2O of the temperature-tolerance of adult Drosophila. Deuterium oxide, D(2)O, increases the temperature-tolerance of Drosophila pseudoobscura when it is administered to adult flies as a sucrose solution. The effect is very rapidly exerted; it is detected within 10 min after the flies have a brief (10 min) opportunity to drink. This increased resistance to heat-death surely implies an increased resistance of macromolecules to thermal denaturation. D(2)O is known to exert such an effect on in vitro protein solutions. The speed with which the increased stability develops clearly implicates a solvent action of D(2)O, and is most easily understood if the effect is traceable to enhancement of the hydrophobic interactions which contribute to conformational stability. The increased strength of deuterated hydrogen bonds cannot be excluded however. The possible bearing of these results on the hypothesis that D(2)O always increases the period of circadian oscillations by "diminishing the apparent temperature" is briefly considered.


Demonstration of electrogenic Na+-dependent D-glucose transport in intestinal brush border membranes. Na(+)-coupled D-glucose transport was studied in isolated membrane vesicles from intestinal brush borders. Concentration gradients of SCN(-), K(+), and H(+) were established between the intravesicular solution and the incubation medium and their influence on D-glucose uptake from the medium was measured. A gradient (medium > vesicle) of NaSCN, but not of KSCN, produced a transient overshoot of D-glucose uptake above the equilibrium level. Similarly, an increase of the membrane conductance with valinomycin (K(+)-conductance) or with uncoupling agents of oxidative phosphorylation (H(+)-conductance) induced an overshooting D-glucose uptake, provided a (vesicle > medium) K(+)-gradient or a H(+)-gradient, respectively, was present in each case. The transient overshoot is evidence that D-glucose was taken up against its concentration gradient (up to 10-fold). The gradients of SCN(-), K(+) (in the presence of valinomycin), and H(+) (in the presence of uncouplers) are thought to contribute to the "driving" force for this "active" D-glucose transport by changing the electrical potential across the vesicle membrane and thus making the inside more negative (with respect to the medium). These experiments, therefore, provide evidence that the Na(+)-coupled D-glucose translocation across the brush border membrane is an electrogenic process, i.e., the positive charge associated with Na(+) is not compensated by the co-movement of an anion or the counter-movement of a cation via the glucose "carrier". The results imply that an electrical potential across the brush border membrane may play an important role in determining the transport of D-glucose by intact cells.


Metabolism of 25-hydroxyvitamin D3 in anephric rats: a new active metabolite. After the injection of radioactive 25-hydroxyvitamin D(3) into rats given a normal diet, two metabolites can be detected on Sephadex LH-20 chromatography modified to reveal polar metabolites. The first is designated peak Va, which by means of periodate cleavage has been identified as 24,25-dihydroxyvitamin D(3). The second more polar metabolite has been designated peak X(1) and is only partially sensitive to periodate. This metabolite appears in serum, bone, intestine, and liver and does not chromatograph on any system like any of the previously identified metabolites. Nephrectomy, especially in the animals given large doses of 25-hydroxyvitamin D(3), does not abolish production of either peak Va or X(1), revealing that both metabolites can be made in extra-renal tissue. Peak X(1) has marked ability to elevate serum calcium of rats on a vitamin D-deficient, low calcium diet, but requires the presence of kidneys to carry out this function.


The kinetics of conformational changes in hemoglobin, studied by laser photolysis. Photolysis of carbon monoxide and oxygen derivatives of hemoglobin by a short laser pulse produces a transient species that rapidly decays to normal deoxyhemoglobin. The effect, which is also observed on single chain proteins and on noncooperative aggregated forms, has been interpreted as corresponding to structural changes in the heme pocket on ligand dissociation. The decay of the transient species follows first-order kinetics with constants ranging from 0.8 to 1.8 x 10(7) sec(-1). In cooperative hemoglobins, the kinetic constants are pH-dependent, though remaining first- or pseudo first-order at all wavelengths. This shows the close linkage of tertiary and quaternary structure changes in normal hemoglobin.