Studies of newly synthesized ribosomal ribonucleic acid of Escherichia coli. 1. RNA synthesized by Escherichia coli during one-hundredth of the generation time contains two fractions distinguishable by hybridization with homologous DNA. One fraction, approximately 30% of the newly synthesized RNA, did not compete with ribosomal RNA, being apparently messenger RNA. The other fraction, approximately 70% of the newly made RNA, hybridized as ribosomal RNA. These values are comparable with previous estimates (McCarthy & Bolton, 1964; Pigott & Midgley, 1968). 2. Hybridization-competition experiments showed that the newly made RNA associated with 70s ribosomes and larger ribosome aggregates was a mixture of ribosomal RNA and messenger RNA, whereas that associated with nascent ribosomal subunits consisted exclusively of ribosomal RNA. This observation provides means by which newly synthesized ribosomal RNA can be isolated free from messenger RNA. 3. Newly made ribosomal RNA in nascent ribosomal subunits was sensitive to shear under conditions where ribosomal RNA in mature ribosomes was shear-resistant. Thus, when RNA was extracted from cells of E. coli disrupted by mechanical means, newly made ribosomal RNA appeared heterogeneous in size, sedimenting as a broad peak extending from 8s to 16s. 4. Newly synthesized ribosomal RNA in nascent ribosomal subunits was rapidly degraded in the presence of actinomycin D and during glucose starvation. 5. Newly synthesized ribosomal RNA stimulated amino acid incorporation in a system synthesizing protein in vitro to the same extent as the RNA which contained the messenger RNA fraction.


The functional characterization of mitoribosomes from rat liver and Krebs 2 ascites-tumour-cell mitochondria.


A substoicheiometric assay for the determination of free adenosine triphosphate in the presence of reversibly bound adenosine triphosphate.


Developmental and regional variations in ribonucleic acid synthesis on cerebral chromatin. 1. Chromatin was prepared from purified nuclei isolated from liver and cerebral regions of the rat. 2. The capacity of these preparations to promote RNA synthesis in the presence of bacterial RNA polymerase was determined. 3. The rate of RNA synthesis on chromatin was normally 12-21% of the rate observed with native DNA, but was markedly stimulated on addition of 200mm-ammonium sulphate. 4. At physiological concentrations (80mug./ml.), the brain-specific S-100 protein inhibited RNA synthesis on DNA and chromatin. 5. Cerebral chromatin from foetal and newborn animals was more active in RNA synthesis than were the analogous preparations from liver. 6. Cerebellar chromatin maintained a high rate of RNA synthesis during brain maturation. In contrast, RNA synthesis on chromatin from other brain regions and liver declined with age of the rat. 7. RNA synthesized on chromatin stimulated amino acid incorporation in an Escherichia coli ribosomal system and hybridized with homologous DNA. 8. RNA synthesized on chromatin from adult cortex or hindbrain hybridized with DNA to a greater extent than that synthesized on cerebellar chromatin. 9. The proportion of RNA formed on cerebral-cortical chromatin that hybridized with DNA increased with age of the rat. 10. The results indicate that the total amount and the types of RNA synthesized on cerebral chromatin vary regionally and during development.


The occurrence of bound serine in acetone extracts of Serratia marcescens exclusively in compounds of a cyclic depsipeptide structure related to serratamolide.


Role of liver-cell potassium ions in secretion of serum albumin and lipoproteins. 1. The incorporation of l-[1-(14)C]leucine into the proteins of liver slices and into the serum albumin and lipoproteins transported by these slices was investigated. 2. Transport rates were found to be dependent on the K(+) content of the slices. 3. The effect of K(+) on transport of serum albumin and of serum lipoprotein can be separated from any effect on synthesis by altering K(+) concentrations after inhibition of protein synthesis by cycloheximide or puromycin. 4. The effect of low K(+) concentrations is reversible. 5. There is linear relationship between the K(+) content of the slices and the transport of protein. A simple method is described for maintaining various steady concentrations of K(+) in the liver slices. 6. K(+) may be replaced by Rb(+). Cs(+) is partly effective, but NH(4) (+) and Li(+) are no more effective than Na(+). 7. We found evidence that K(+) content rather than the flux rates of K(+) or Na(+) is important in this effect. 8. These results are probably important in ethionine and carbon tetrachloride poisoning in the rat, and may be significant in liver transplantation.


Effects of hypothalamic lesions on protein-bound 131-iodine and thyroidal 131-I uptake in the chicken.


André Thomas.

André Thomas.


Salmonella spp. and serotypes of Escherichia coli isolated from the lesser mealworm collected in poultry brooder houses.


The biomechanical development of injury-attenuating motor vehicle design.


Suprachiasmatic LH-releasing factor.

Suprachiasmatic LH-releasing factor.


Recent research in child development.

Recent research in child development.


Effect of heparin administration on plasma growth hormone concentrations.


Reaction of bovine conglutinin in human in vitro phagocytic systems.


Promotion of activation of pepsinogen by polyanions including RNA and sulfated mucosubstances.


Hemoglobin synthesis in mice after bone marrow transplantation.


Effective and ineffective antilymphocyte sera correlation of in vitro tests with potency of early antisera.


Studies on marrow histogenesis. I. The site of choice for extramedullary marrow implants.


Effect of antihistamine on reproductive organ and body growth and attainment of puberty in female rats.


Stimulation of release and synthesis of growth hormone (GH) in tissue cultures of anterior pituitaries in response to GH-releasing hormone (GH-RH).


Production of fibrinogen following an endotoxin injection.


Conditioned insulin secretion in the albino rat.


Inhibition by chloroquine of UV repair in E. coli B.


Review of cerebral edema.

Review of cerebral edema.


The snakes.

The snakes.


Influence of triphenyltim acetate on lymphatic tissue and immune responses in guinea pigs.


The cochlea and the cochlear nuclei in the bat.


Atypical cilia in normal human and guinea pig middle ear mucosa.


Formation and structure of the spinal nerve.


Morphologic changes in vestibular hair cells in a strain of the waltzing guinea pig.


Ventricular function in atrial septal defect.


Tuberous sclerosis.

Tuberous sclerosis.


Toxoplasmosis of the central nervous system in the adult. A light and electron microscopic study of three cases.


Depolarization of the intrinsic and extrinsic fluorescence of pepsinogen and pepsin. 1. The effects on the intrinsic tryptophan emission anisotropy of pepsin and pepsinogen solutions produced by (a) changes in temperature, (b) increases in viscosity with added glycerol at constant temperature and (c) decreases in lifetime through collisional quenching by potassium iodide were measured at several excitation wavelengths. The rotational-relaxation times calculated from results provided by method (b) approximate to the theoretical values for the two proteins, on taking hydration and shape factors into account, on the basis of random orientation of the tryptophan groups within the macromolecules. Differences between the results provided by methods (b) and (c) are attributable to inter-tryptophan resonance-energy-transfer depolarization, and the anomalous values recorded in method (a) can be attributed to the temperature-dependence of the limiting anisotropies. 2. Two different monomeric conjugates of pepsin, each containing one extrinsic fluorescent group per macromolecule, gave widely different relaxation times. This difference may arise from a specific orientation of the emission dipole in the enzyme. In active-site-labelled pepsin (1-dimethylaminonaphthalene-5-sulphonylphenylalanine-pepsin) this orientation would be approximately parallel to the symmetry axis of the equivalent ellipsoid, whereas in the other conjugate (1-dimethylaminonaphthalene-5-sulphonyl-pepsin) the orientation may be roughly normal to this direction, or some independent rotation of parts of the protein molecule is possible.


Studies on the heterogeneity of human gastric zymogens. THE PEPTIC ZYMOGENS OF HUMAN GASTRIC MUCOSA HAVE BEEN STUDIED IN THE PAST BY THREE DIFFERENT TECHNIQUES: phosphate-gradient chromatography on a column of DEAE-cellulose, chloride-gradient chromatography on DEAE-cellulose and agar-gel electrophoresis. These techniques have given different results, each suggesting the presence of a different number of pepsin zymogens in human gastric mucosa. In the present experiments gastric mucosal homogenates were subjected to analysis by all three techniques. The two major zymogen peaks obtained from phosphate-gradient chromatography were found to be composed of the three fractions found on chloride-gradient chromatography; these fractions in turn were shown to be heterogeneous on agar-gel electrophoresis. The latter technique demonstrated the presence of seven separable enzymically active components in human gastric mucosal homogenates. The relationships of the components separated by the three techniques are discussed.


Urological complications of renal transplantation.


Cortical hormones, systemic and topical. Jubilee memorial lecture.


The amino acid sequences of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin. 1. The half-cystine content of ovotransferrin, measured as cysteic acid, was 31mol/80000g of protein. 2. The amino acid sequences of cysteic acid-containing peptides from performic acid-oxidized ovotransferrin were studied. 3. 34 unique cysteic acid residues were identified. 4. It is concluded that hen ovotransferrin does not consist of two identical halves or subunits.


Bulbar and suprabulbar control of the cardiovascular autonomic effects during arterial hypoxia in the rabbit.


Induction of DNA synthesis in lymphocytes from ALG-treated patients.


Technic-cosmetic treatment of gingival recession: pseudo-gingiva.


Social Security answers in the dentist.

Social Security answers in the dentist.


A review of alumina re-inforced restorative units.


Effect of sciatic neurectomy on myelinogenesis in the rat spinal cord.


Adrenosem therapy for bleeding coincident with the use of intrauterine contraceptive devices: a double blind study.


Some factors affecting membrane immunofluorescence reactivity of Burkitt lymphoma tissue culture cell lines.


Direct membrane fluorescence reaction of EBV-carrying human lymphoblastoid cells: blocking tests with xenogeneic antisera.


Enhancing antibody. 3. Site of activity.


Why antibody inhibits vascular clearance of staphylococcal enterotoxin B.


The biology and vector capability of Triatoma sanguisuga texana usinger and Triatoma gerstaeckeri (Stål) compared with Rhodnius prolixus (Stål) (Hemiptera: Triatominae).


Diastematomyelia and the tight filum terminale.


Stanley Cobb (1887-1968).

Stanley Cobb (1887-1968).


Similarity, recall, and appraisal of others.


Inherited resistance and mouse typhoid. I. Some factors which affect the survival of infected mice.


A method for the electron microscopic study of cerebrospinal fluid sediment.


Antibacterial action of vegetable extracts on the growth of pathogenic bacteria.


Reference standards for cortisol production and 17-hydroxy-corticosteroid excretion during growth: variation in the pattern of excretion of radiolabeled cortisol metabolites.


National Council of Women's Woman of Conscience Award to Annie Mae Bankhead.


American Public Health Association Sedgwick Memorial Medal to Marion W. Sheahan.


The hemodynamic effects of diphenylhydantoin in patients with fixed rate pacemakers.


Surgical approaches to midline lesions at the base of the skull: a review.


Occlusion, articulation and the development of a functional masticatory apparatus. II. Principal elements of motion.


William Dameshek, M.D., 1900-1969.

William Dameshek, M.D., 1900-1969.


Simultaneous temporal and delto-pectoral flaps for full-thickness defects of the cheek.


Tubed neck flaps in facial reconstruction.


On restoring sunken noses without scarring the face.


Cervical auriculars; congenital chondro-cutaneous appendages of the neck.


A muscle-skin pedicle for total reconstruction of the lower lip; case report.


Marriage research and conflict: an integrative review.


Identification of creativity: the individual.


Reexamination of the role of the hypothalamus in motivation.


Cooperation of dentist and dental laboratory. Application of systematized materials.


The occlusionally required functional impression of the interalveolar space in case of a complete denture.


Editorial. Oh, my aching fingers. Telephone directories.


Recovery of neuronal function after prolonged cerebral ischemia. Cats were submitted to complete cerebral ischemia by clamping the innominate and subclavian arteries and simultaneously lowering the systemic blood pressure. Neuronal function was assessed by recording the electroencephalogram and the anti- and orthodromic activation of the pyramidal tract. A full recovery of the pyramidal response and even of evoked electroencephalographic activity occurred after ischemia of more than 1 hour's duration.


Improved surgical technique for arteriovenous shunt implantation: experiences with an all-Silastic shunt.


Experimental studies on the effect of dimethyl sulfoxide on pedicle flaps.


Hemodynamic alterations and results of treatment in patients with gram-negative septic shock.


The immunologic response to intravascular skin allografts.


Thiothixene and trifluoperazine in a step system.


The value of worsening rates in psychiatric clinical trials.


Auxiliary homotransplantation of the porcine liver into the retroperitoneal space.


Vampire-bat transmitted rabies virus from Surinam. Comparison of properties with European street virus and fixed virus.


Nicolaas Hendrik Swellengrebel, August 12th, 1885-January 1st, 1970.


Long-term cardiac pacing. Experience of fixed-rate pacing with an endocardial electrode in 260 patients. XIV. The effect of lanatoside C on ventricular automaticity in man.


Electron microscopic studies of the otosclerotic focus.


Glycogen in the inner ear after acoustic stimulation. A light and electron microscopic study.


Some morphological aspects of sound perception in birds.


Activity of acetylcholinesterase on the endolymphatic surface of outer hair cells.


Fear and escape reaction evoked by the intrahypothalamic injection of D-tubocurarine in unrestrained cats.


Effects of nicotine and tobacco smoke on gastric secretion in rats with gastric fistulas.


Current publications in gerontology and geriatrics.


Uremia (first of two parts). Uremia. I.

Uremia (first of two parts). Uremia. I.


Compensatory mechanisms in congestive heart failure--the role of the peripheral resistance vessels.


Standards of early american medical education.


Chemistry and biology of the histones.

Chemistry and biology of the histones.


Sensory mechanisms in mammalian teeth and their supporting structures.


Oxygen and carbon dioxide gas stores of the body.


Selective chemical modification of proteins.


Idiopathic juvenile osteoporosis: report of a case and review of the literature.


Emphasis on surgical technic and judgment in the management of gastric ulcers.


Improved technic for canine lung transplantation.


A new procedure for portal decompression: proximal splenic-caval anastomosis.


Histidine decarboxylase activity of the rat spleen following skin allografting.


Diabetes mellitus in Mystromys albicaudatus.


Heterologous serum-induced cellular alterations in the renal papilla. In vitro studies.


Specific binding to adenylosuccinate synthetase of analogs of inosinic acid with nitrogen, sulfur, and carbon substituted for phosphate oxygens.


Intramolecular hydrogen transfer catalyzed by UDP-D-glucose 4'-epimerase from Escherichia coli.


Lethal and mutagenic lesions induced by ionizing radiations in E. coli and DNA strand breaks.


The etiology of transient synovitis of the hip in childhood.


Gastrocnemius-plasty for primary closure of compound injuries of the knee.


Sir Frank Wild Holdsworth 1904-1969.

Sir Frank Wild Holdsworth 1904-1969.


Sir Walter Mercer.

Sir Walter Mercer.


Miescher's discoveries of 1869. A centenary of nuclear chemistry.


The management of open skeletal trauma with particular reference to internal fixation.


Histological skin reaction to pokeweed in humans.


Defense mechanisms of mollusks.

Defense mechanisms of mollusks.


Biphasic response of the reticuloendothelial system (RES) induced by pyran copolymer.


Introductory report on ST responses to maximal exercise, quantitative measurements, time course and relationships.


Exercise tolerance tests in cardiac patients and the use of the computer in such studies.


A method of quantitative evaluation of disturbances in heart rhythm during physical activity.


Man and aggression.

Man and aggression.


Imunohistochemical localization of hormones in the human adenohypophysis.


Types of neuronal activity in the medial vestibular nucleus.


Albert Camus. Camus' The Fall: the Icarus complex.


Passive ion transport through the Reissner membrane.


Camus' Stranger: his act of violence.

Camus' Stranger: his act of violence.


Camus' The Stranger: the silent society and the ecstasy of rage.


Pimaricin therapy of cephalosporium and fusarium keratitis.


As I remember her--Beryl J. Roberts.

As I remember her--Beryl J. Roberts.


X-ray irradiation of the inner ear of the guinea pig. Early degenerative changes in the cochlea.


Eight nerve in experimental lead poisoning.


Bookshelf for the community health nurse specialist.


A selected public health bibliography with annotations.


The medicolegal framework for clinical research in medicine.


Conducting investigational drug studies for industry.


Transfusion in hemophilia.

Transfusion in hemophilia.


Tympanosclerosis. Electron microscopic study.


A randomized controlled trial of ergotamine tartrate.


Placental localisation.

Placental localisation.


Skull injury from stoning--in Western Samoa and in history.


The concept of mainstream medicine for all Californians. Fifth progress report of Committee on Role of Medicine in Society. 3. This Fifth Progress Report is being printed in three parts in California Medicine. Following the appearance of Part III the report will be bound in a pamphlet which may be ordered at $1 a copy from 693 Sutter Publications, Inc., 693 Sutter Street, San Francisco, California 94102.


Cytological localization of DNA complementary to ribosomal RNA in polytene chromosomes of Diptera.


Ammonia in clinical medicine. I. Some aspects of ammonia metabolism.


The chemistry of lysozyme.

The chemistry of lysozyme.


Nursing service.

Nursing service.


In memoriam Professor Guido Guida.

In memoriam Professor Guido Guida.


Studies on the mechanism of target cell lysis induced by immune cells.


Topical treatment of minipig split thickness skin graft donor sites using 2-cyanoacrylate homologues.


Histocompatibility antigens as markers for investigating population dynamics of lymphoid cells.


A pilot trial of sustained-release aspirin ("Bi-Prin").


Measles in Australia and New Zealand, 1834-1835.


With good advice and little medicine.

With good advice and little medicine.


A new type of oral contraceptive.

A new type of oral contraceptive.


Plasma pepsinogen levels in three races of Malaysia.


Severe shear injury to the buttocks and perineum.


Senator Mansfield, his mark.

Senator Mansfield, his mark.


Uremia. II.

Uremia. II.


Use of a streptomycin-dependent Escherichia coli strain for the quantitative determination of streptomycin residues in fruit.


High-pressure injection injuries of the hand.


Supraorbital and glabellar fractures.

Supraorbital and glabellar fractures.


Secondary correction of velopharyngeal incompetence. A review.


A new method for earlobe reconstruction.


Multiple dorsal rotation flaps from the hand for thumb web contractures.


The correction of angular deformities of the nose by a subcutaneous operation.


Phalangizing the first metacarpal. Case report.


Dream discussion as a means of reopening blocked familial communication.


Tuberculosis of the nervous system.

Tuberculosis of the nervous system.


Biochemical differentiation during amphibian metamorphosis.


The cyclic dynamism of the incidence and complications of ulcer disease.


A biographical sketch. David A. Karnofsky.


Function of auxiliary liver allografts.

Function of auxiliary liver allografts.


Helena Emma Riggs 1899-1968.

Helena Emma Riggs 1899-1968.


Infectious feline panleukopenia. (Developmental report of a tissue culture origin formalin-inactivated vaccine).


In memoriam. Ralph Irving Lloyd, 1875-1969.


Nutrition and diseases of the endocrine glands.


A comparison of intestinal and renal transport systems.


Gastrin and absorption. A review.

Gastrin and absorption. A review.


The combined bacteriostatic activity of chloramphenicol and benzalkonium chloride.


Assessment of bronchodilator drugs on asthmatic out-patients by daily measurements of the peak expiratory flow rate.


Chemical heterogeneity of ribosomal protein of Escherichia coli examined by electrofocusing.


Poultry environment in the U. K. A review of progress.


Studies on the sense of smell to ketone compounds in a Hungarian population.


Protein synthesis in the medulla of the rat brain. Reproducibility of the results.


The effect of botulinum toxin on uptake of calcium by synaptosomes.


Noradrenaline uptake into cerebral cortex: a histochemical study.


Lymphoma-like lesions induced in the hamster cheek pouch with topical vitamin A palmitate.


Attachment and feeding behavior of Ancylostoma caninum.


Immediate revascularization of the ischemic heart. Clinical experience with 70 cases.


Pulmonary blastoma. A case report and review of the literature.


An evaluation of influenza immunization: influence of route of administration and vaccine strain. A field study was undertaken in Tampa, Fla., to assess the efficacy of subcutaneous and aerosol methods of administering vaccine, and to compare the protection afforded by bivalent (A2 and B) influenza virus vaccine and by A2/Hong Kong/68 virus vaccine. Further objectives of the study included a comparison of the effectiveness of single-dose and 2-dose immunization. Approximately 2100 volunteers received, in a double-blind manner, both an injection and an aerosol administration on 2 occasions 3 weeks apart. The results showed that aerosol administration gave a lower over-all protection rate, although the booster dose seemed to have a marked effect. The protection afforded by A2/Hong Kong/68 virus vaccine was considerably greater than that afforded by the bivalent vaccine, particularly when administration was subcutaneous. Results are also given on the occurrence of side-effects and on the correlation between cigarette smoking and the occurrence of influenza-like illness.


Evaluation of amantadine hydrochloride in the treatment of A2 influenzal disease. Amantadine hydrochloride is the first drug to show promise as a practical anti-influenza agent. Several studies demonstrating a prophylactic effect in volunteers with induced A2 disease as well as in patients during A2 outbreaks have created the impetus for therapeutic trials. The widespread A2 influenza epidemic that occurred early in 1968 provided the opportunity for therapeutic evaluation in the USA.A total of 197 prison inmates with proven influenza agreed to participate in the 10-day double-blind evaluation of amantadine (100 mg, twice daily). Onset of therapy was approximately 20 hours after first subjective awareness of illness.Assessment of drug effectiveness was based on rapidity of resolution of illness. There was a significant increase in the number of drug-treated as against placebo patients in the "rapid resolver" group whereas individuals receiving placebo dominated the "slow resolver" group. Analysis of febrile responses indicated that amantadine-treated patients had significantly more rapid defervescence. Virus isolation studies revealed etiologically related virus in 90% of all volunteers during the first 5 days of therapy. It was apparent that clinical improvement was not correlated with disappearance of the virus. Nevertheless, the trials conducted during the influenza season of early 1968 indicated the therapeutic effect of amantadine hydrochloride. Administration of 100 mg, twice daily, for 10 days did not cause any adverse effects.


Study of 1-adamantanamine hydrochloride used prophylactically during the Hong Kong influenza epidemic in the family environment. 1-Adamantanamine hydrochloride (aminoadamantane) has been shown to inhibit the multiplication of influenza A viruses in cell cultures, organ cultures and experimentally infected mice. An epidemic of influenza in Great Britain in the winter of 1967-68 provided the opportunity to study the prophylactic effect of aminoadamantane in the family environment and this paper reports the results of further observations in January-March 1969 during an influenza epidemic due to A2/Hong Kong/68.In a double-blind, placebo-controlled investigation of aminoadamantane given prophylactically, in doses of 100 mg every 12 hours for 10 days, no protective effect of the drug was demonstrated. In view of the positive effect of the drug in the earlier study during the winter of 1967-68, and the apparent sensitivity of the virus strain, an explanation involving the very high incidence of individuals possessing HI antibody of less than 1:12 is offered.


Mass lesions of the mediastinum.

Mass lesions of the mediastinum.


Human ecology in medicine.

Human ecology in medicine.


Predictive functions in the control of annual cycles.


A technique for breast reduction.

A technique for breast reduction.


Stereotaxic cryosurgery in the management of acromegaly.


Influence of induced uterine infection at various stages of the estrous cycle on the corpus luteum of the ewe.


Darwin and heredity: the evolution of his hypothesis of pangenesis.


The contributions of Heinrich and Hermann Berghaus to medical cartography.


The founding of the Yale School of Applied Chemistry.


The study of medicine at the Vermont Academy of Medicine (1827-29) as revealed in the Journal of Asa Fitch.


Le malade imaginaire. A lithograph by Daniel Maclise.


The effect of autotransplantation on the progression or reversibility of aging in human skin.


Neomycin-induced spiral organ degeneration in the guinea pig. A study using the surface specimen technique.


Psychomotor epilepsy: rehabilitation after surgical treatment.


Directory of otolaryngologic societies.

Directory of otolaryngologic societies.


A comparison of marijuana users and non-users.


Effect of thymine concentration on the replication velocity of DNA in a thymineless mutant of Escherichia coli.


Effects of interferon inducers on the intracellular growth of the protozoan parasite, Leishmania donovani.


Induction of resistance to bacterial infections of mice with poly I-poly C.


Concentration of rubella virus antigen in chondrocytes of congenitally infected rabbits.


X-ray mutagenesis of cultured Chinese hamster cells.


The current state of high resolution scanning electron microscopy.


Physics and chemistry of spin labels.

Physics and chemistry of spin labels.


Transfer of a primary immune response by homologous sensitized cells.


ABO blood group incompatibility in renal transplantation.


Comparison of rabbit antimouse thymus sera produced after different numbers of injections of lymphoid cells.


The ultrasonic velocity detector for determining vascular patency in renal homografts.


Effect of the number of injections of antigen on the effectiveness of antilymphocyte serum.


Allograft rejection in the lizard Calotes versicolor.


Inhibition of the development of primary antitoxic immunity by heterologous antilymphocyte serum.


Fatty acids in Staphylococcus aureus and Escherichia coli cultured in vivo.


Colicin sensitivity and colicinogenity of type O124:K72(B17) E. coli strains.


Immunological aspects of malaria infection.


Genetic control of specific immune responses.


The lesions in cell membranes caused by complement.


The physiologic-psychologic relationship: some experiences during experiments in a medical research institution.


Skin graft survival in partially inbred beagles.


Clinical experience with a plastic short leg brace.


On the pharmacology of marihuana.

On the pharmacology of marihuana.


Problems of toxicants in marine food products. 1. Marine biotoxins. The expansion of marine fisheries into tropical waters, which is now occurring, will increase the risks of widespread poisonings because of the abundance of biotoxins in warm-water organisms. However, toxic marine organisms are not only a health hazard but also a possible source of new pharmaceutical products.A classification of marine intoxicants is given in this paper with special reference to the oral biotoxins which will be of primary concern in the expansion of warm-water fisheries. The biotoxins are both invertebrate (e.g., molluscs, arthropods) and vertebrate (mostly fishes) in origin. Biotoxications of vertebrate origin may be caused by the muscles, the gonads or the blood of certain fishes or by special poison glands not equipped with traumagenic devices. (Venomous fishes, having poison glands and traumagenic spines, etc., are of no direct concern as oral intoxicants.)The ichthyosarcotoxic fishes, in which the flesh is poisonous, appear to constitute the most significant health hazard. A list of fishes reported as causing ciguatera poisoning (one of the most serious and widespread forms of ichthyosarcotoxism) is included in this paper.


Rat gastric secretion following acute exposure to nicotine.


Cholera: a continuing threat and challenge.


Skin--the interface between man and tropical environments.


Pathology of gastrointestinal helminthiases.


Ovarian and pituitary gland changes in hysterectomized postpartum sows treated with FSH and oxytocin.


The Rutgers Drawing Test and intelligence: a preliminary comparative study.


Disappearance of naturally fixated luminous stimuli and stability of phase sequences: a selective review and related experiment.


Perception bibliography: 43. Psychological Abstracts, 1931, volume 5.


Perception bibliography: XLIV. Psychological Abstracts, 1932, volume 6.


The influence of the artificial kidney, nephrectomy, and kidney transplantation on the human circulation.


Electron microscopic investigations on the human carotid body. (Preliminary communication).


The structure of the cerebral cortex of the Ganges dolphin Susu (Plactanista) gangetia Lebeck 1801.


Vesicle and granule content of sympathetic ganglion cells during limb regeneration of the newt Triturus.


Anionic binding of ruthenium red in fish extraocular muscle.


Morphological studies of possible neuroendocrine structures in Helisoma tenue (Gastropoda: Pulmonata).


Human cochlear aqueduct.

Human cochlear aqueduct.


The combination of gas chromatography and mass spectrometry in the identification of drugs and metabolites.


Cerebellar degeneration in thiamine-deficient rats.


The effect of glucagon on renal hemodynamics and renal arteriography.


Regional pulmonary function in man. Quantitative transmission radiography as an adjunct to lung scintiscanning.


Martin Herman Wittenborg, M.D., 1914-1969.


Dermal arthroplasty.

Dermal arthroplasty.


Importance of blood-group substances in interactions between man and microbes.


Recovery of anaerobic microorganisms from clinical specimens in prereduced media versus recovery by routine clinical laboratory methods. Prereduced anaerobically sterilized culture media, used with rigid adherence to the cultivation techniques described by Moore and his associates, were capable of recovering more than twice the number of anaerobic bacteria from clinical specimens than could be recovered by the conventional use of fluid thioglycolate medium and of blood-agar plates incubated anaerobically with hydrogen generation packets. No loss of clinical isolates was encountered with the more sensitive methods; however many of the isolates recovered only in prereduced media would not grow when placed into thioglycolate medium. A representative anaerobic isolate placed into aerobic transport broth was unable to survive beyond 30 min. Methods employing prereduced media were not difficult to master and were feasible for clinical laboratory use. Evidence implicating the gingival crevice flora as an important possible source of anaerobic bacteria that become involved in systemic infections was considered.


Assay of Chikungunya virus in cell monolayers by immunofluorescence. Chikungunya virus was quantitatively assayed by counting immunofluorescent foci after infection of BHK21/C13 cell monolayers. The speed and efficiency of virus attachment to cells were markedly enhanced when augmented by centrifugal force. By this procedure, a proportionality was obtained between the number of immunofluorescent foci and the volume of inoculum. Virus penetration into cells was linear and complete within 15 min at 35 C. From observations on the sequential development of viral antigen within cells and immunofluorescent focus counts, foci of infected cells may be enumerated as early as 16 hr after inoculation of cell monolayers. A linear function was demonstrated between immunofluorescent focus counts and relative virus concentration. The immunofluorescent assay was comparable in sensitivity but more precise and rapid than virus assays based on the intracerebral inoculation of suckling mice or on plaque counting. By the immunofluorescent procedure, the 50% neutralizing end point of antiviral serum was rapidly and quantitatively determined.


Accumulation of Escherichia coli by the Northern quahaug. The uptake of Escherichia coli by the quahaug, Mercenaria mercenaria, was studied to obtain an insight into the environmental parameters significant to the accumulation of bacterial pathogens by shellfish growing in polluted waters and into the kinetics of the uptake process. Experimental uptake was achieved by placing the animals in a flowing water system in which the contamination level of the water and its temperature and salinity could be controlled. Data from periodic assays of individual animals suggested that accumulation of the bacteria by the quahaug proceeds to an equilibrium level which is a function of E. coli content of the water and its overall particulate matter. Accumulation takes place in the digestive gland and, to a lesser extent, in the siphon of the animal.


Comparative enumeration of lipophilic and nonlipophilic cutaneous diphtheroids and cocci. Swabbing skin to collect bacteria for enumeration revealed that a single washing or rinsing of the swab in buffer removed between 90 and 95% of the bacteria collected. Further removal of the remaining bacteria from the initial swab by repeated washings of the swab produced plate counts that showed nearly proportional decreases in the numbers and types of bacteria retained or eluted from the swab. None of the commonly isolated cutaneous bacteria was retained or eluted from the single swab in numbers that misrepresented measurement of their proportions present in the sample. Populations of nonlipophilic bacteria on skin when present were mainly gram-positive catalase-producing cocci. Diphtheroids when present were chiefly lipophilic. Media containing furoxone were selective for cutaneous diphtheroids. The concentration of furoxone used affected isolation and enumeration of the diphtheroids. Lipophilic diphtheroids from the stratum corneum were basically aerobic and anaerobic incubation reduced or eliminated this group from enumeration studies. Lipophilic furoxone-resistant aerobic diphtheroids from several areas, particularly the nasal passages, occurred in numbers inversely proportional to the numbers of staphylococci for periods up to 11 months. The cocci-diphtheroid relationships occurred independently of the total number of aerobic bacteria present, the transient appearance of yeasts or gram-negative bacilli, the required use of certain antibiotics by the subjects, climate, age, and sex.


Mycoplasma recovery from the male genitourinary tract: voided urine versus the urethral swab. A study of Mycoplasma recovery from the genitourinary tract was made on a group of 50 males attending a venereal disease clinic. The purpose of the investigation was to compare recovery rates of mycoplasma from two types of clinical specimens-the urethral swab and voided urine. The total number of positive cultures did not differ significantly when either the swab or urine was used; Mycoplasma hominis type 1 was the only taxonomic species isolated, either alone or mixed with T-strain mycoplasma. Recovery rates of the two types from both the swab and the urine did not differ significantly. Age did not relate to the presence of mycoplasma in the group studied.


Separation of Treponema pallidum from tissue debris through continuous-particle electrophoresis. Treponema pallidum can only be cultured in living animal tissue, such as rabbit testes. However, the extract of these organisms from the testicular material leaves the T. pallidum contaminated with tissue debris. This paper describes the separation of T. pallidum from the debris by continuous-particle electrophoresis. The importance of equilibration time before electrophoresis is discussed.


Colorimetric assay for lysine decarboxylase in Escherichia coli. A new assay is described for lysine decarboxylase. It is rapid and reproducible in assaying large numbers of samples, a situation in which earlier methods were less convenient. The new method is valuable in the study of peptide fractions and amino acid mixtures which stimulate induction of lysine decarboxylase. It may be useful for work on enzyme structure and modification, genetics, and kinetics.


Passage of Treponema pallidium through membrane filters of various pore sizes. The passage of Treponema pallidum through commercially available Millipore membrane filters of various pore sizes was examined. No microscopically detectable organisms passed through a filter with a pore diameter of 0.22 mum. As pore size was increased, progressively more organisms passed through. Motile organisms passed through filters to a greater extent than nonmotile ones; however, 22% of the motile and 50% of the nonmotile T. pallidum organisms did not pass through the largest pore diameter tested (14.0 mum). Filtration of T. pallidum suspensions through membrane filters may offer a way of separating the organisms from larger particles of debris which accompany their extraction from rabbit testicular syphilomas.


Radiation treatment of foods. II. Public health significance of irradiation-recycled Salmonella. Salmonellae resistant to gamma irradiation were developed by repeated irradiation and subculturing in a nutrient broth-yeast extract medium. Few differences were noted in the biochemical characteristics of parent and resistant cultures; however, microculture studies revealed variations in morphology and in cell division patterns. A considerable decrease in pathogenicity for day-old chicks was apparent with resistant cultures, but their phenol-water extracts were as toxic as parent material for 10-day chick embryos. Five serial chick passages did not reverse the reduced pathogenicity or aberrant morphology of a resistant Salmonella typhimurium culture. Results of phage typing of both parent and serially irradiated S. typhimurium were inconclusive, whereas the O-1 genus-specific phage lysed all parent serotypes tested but only one of the serially irradiated cultures. Agglutination of parent S. typhimurium cells with their homologous rabbit antiserum was unaffected by prior absorption with resistant strains. The results indicate that radiation recycling altered Salmonella into strains of lesser public health significance.


Combined medium to determine deoxyribonuclease activity and phenylalanine deamination by Enterobacteriaceae. A combination medium has been developed to aid in the identification of Serratia and urease-negative Providencia recovered from clinical specimens.


Tear gas injuries of the hand.

Tear gas injuries of the hand.


Chikungunya virus infection of cell monolayers by cell-to-cell and extracellular transmission. Both cell-to-cell and extracellular transmission of chikungunya virus infection was demonstrated in BHK21/C13 cell monolayers. The mode of virus infection may depend on the cell line. Virus transmission in L-929 and guinea pig lung cell lines was extracellular.


Instability effects in diffusion analyses of antimicrobial activity. Diameter reductions accompanying preincubation, and funnel-shaped diffusion zones from agar wells, readily demonstrate chemical and physical instability of preparations in antimicrobial analyses.


On the possibility of a stage in the evolution of the genetic message in which replication was imprecise.


Formation of a ternary complex between yeast aminoacyl-tRNA binding factor, GTP, and aminoacyl-tRNA.


E. coli tyrosine transfer RNA: chemical modification of thiouridine to uridine.


DNA-DNA hybridization at low temperature using DNA chemically labeled with 14C-dimethyl sulfate.


Enterobactin, an iron transport compound from Salmonella typhimurium.


Calf thymus RNA polymerases exhibit template specificity.


Purification of a leucine-specific binding protein from Escherichia coli.


Estimating the distribution of spherical and elliptical bodies in conglomerates from plane sections.


S-Adenosylmethionine synthetase deficient mutants of Escherichia coli K-12 with impaired control of methionine biosynthesis.


Multiple serum protein abnormalities in lichen myxoedematosus.


Hereditary angio-oedema treated with E-aminocaproic acid.


Dermatology at the London Hospital.

Dermatology at the London Hospital.


The early orthopaedic surgeons of New York. Robert K. Lippmann memorial lecture.


Cell-mediated immunological processes in leprosy. A large number of organisms such as viruses, protozoa, helminths, fungi and bacteria, especially mycobacteria, need cell-mediated immunological processes for their elimination. As well as being involved in protection, cell-mediated immunological processes are also involved in a number of allergic reactions to products derived from mycobacteria. Cell-mediated immunological processes can be demonstrated by a number of in vitro reactions. Leprosy can present with a wide range of different clinical patterns. The clinical spectrum of leprosy can be shown to depend on the degree of the cell-mediated immune response of the host against Mycobacterium leprae. Thus in tuberculoid leprosy there is a high degree of cell-mediated immune response whereas in lepromatous leprosy such a response is virtually absent. There appears to be a constitutional predisposition to lepromatous leprosy. In addition to a specific loss of cell-mediated immune response against Myco. leprae, there is also a non-specific drop in the ability of patients with lepromatous leprosy to show other aspects of cell-mediated immune response, e.g., contact sensitivity and skin homograft rejection. There is also a relative impairment of the ability of lymphocytes to react in vitro. Lymph nodes from patients with lepromatous leprosy show a deficiency in those areas associated with the development of cell-mediated immune responses.The article includes a discussion on the possible causes of deficiencies in cell-mediated immune responses in lepromatous leprosy.


An extensive community outbreak of enteropathogenic Escherichia coli O86: B7 gastroenteritis. During the last 20 years numerous reports of hospital-associated epidemics of enteropathogenic Escherichia coli (EEC) gastroenteritis have appeared in the medical literature. Some of the reports suggest that EEC gastroenteritis can also be a community problem. However, community epidemics of EEC gastroenteritis comparable to those of other communicable diseases like cholera or typhoid are rare.An extensive epidemic of acute gastroenteritis occurred among children in Surat, Gujarat State, India, between 29 October and 3 December 1965. A total of 418 patients was hospitalized during this period: 344 of them were under 2 years of age. Faecal specimens from 81 children admitted between 25 November and 30 November were subjected to microbiological examination. Of these samples, 34 yielded pure cultures of E. coli O(86):B(7) and 1 yielded a pure culture of O(126):B(16). The cases occurred throughout the town including a rural ward. The morbidity rate for the total population was 0.16% and the age-specific morbidity rate for the 0-2-years age-group, was 0.98%; the highest morbidity rate (2.4%) was in the 6-11-months age-group in the urban wards. No definite mode of transmission of the disease could be established.


Contributions of electron microscopy to the study of myocardial ischaemia. Electron-microscope studies of experimental models of myocardial ischaemia have provided basic information on the pathogenesis of hypoxic heart injury. Correlation of ultrastructural changes with biochemical data confirms the importance of catecholamine release and ionic shifts in the early evolution of ischaemic injury. An altered cellular metabolism induced by ischaemia causes rapid depletion of glycogen and is followed quickly by alterations in the nucleus, the mitochondria and the sarcotubular system; the myofibril is the organelle most resistant to hypoxia.Postmortem autolysis mimics early ischaemic change very closely and it probably has an initial hypoxic basis. Significant hypoxic-autolytic changes may begin during the agonal state. The time elapsing and the techniques of tissue preservation are critical in determining the amount of artefact. At present it is unrealistic to expect to obtain acutely ischaemic human myocardium soon enough after death to be of value in the estimation of the degree or duration of ischaemia by electron-microscope techniques. Rapidly progressive autolytic changes preclude the meaningful morphological assessment of hypoxic change at the ultrastructural level.


Experimental studies of the central nervous system related to anaesthesia. IV. Effects of pentobarbital placement in caudate nucleus.


CI-581 in anaesthesia for tonsillectomies in children.


Mutagenicity and cytotoxicity of irradiated foods and food components. The preservation of foods by treatment with ionizing radiation can significantly increase the world's food resources by reducing spoilage and waste. However, irradiation can bring about chemical transformations in food and food components resulting in the formation of potential mutagens, particularly hydrogen peroxide and various organic peroxides. In order to evaluate the safety of irradiated foods for general consumption by the public, and, indeed, the safety of all foods subjected to environmental factors such as food additives, pesticides, drugs, air and water pollutants, etc., it is necessary to supplement the usual feeding tests with procedures designed to detect all classes of genetic damage. This article includes a comprehensive critical review of (1) the experimental evidence relating to the presence of mutagenic and cytotoxic agents in irradiated media, as detected by their effects on mammalian and non-mammalian cells; (2) the chemical changes produced in irradiated media, especially those which produce known mutagenic substances; and (3) new and convenient in vivo methods for the detection and evaluation of genetic damage in mammals.


A double-blind study of diazepam, droperidol, and meperidine as premedication in children.


Activity and location of two enzyme fractions during the culture cycle of Schizosaccharomyces pombe.


The performance of nine human hearts before, during, and after transplantation.


The detection of Clostridium botulinum type E in smoked fish products in the Pacific Northwest.


Anatomical and functional changes induced by oral contraception. The hormonal contraceptives seem to have no direct effect on cervical carcinoma or dysplasia, but they are responsible for the appearance of glandular adenomatous hyperplasia of the endocervix.The long-term use of progestins is responsible for the inactive appearance of the ovaries, with thickening of the tunica albuginea, rare follicle growth, occasional fibrosis of the stroma and a decreased DNA formation.After stopping oral and injectable hormonal contraceptives the first cycle is usually long and cases of amenorrhea have been reported. The causes of secondary amenorrhea probably lie in the hypothalamus and/or the ovaries.The time lapse between cessation of oral contraception and conception is between 5.8 and 6.5 months. No increase in abortion has been noted, but abortuses and ova have an increased polyploid tendency and incidence of chromosome breaks. Further investigations of larger series are necessary to provide definite proof. Meanwhile it would seem advisable that after cessation of hormonal contraception there should be a time lapse of six to eight months before a patient becomes pregnant.


Male fertility in uremia: restoration by renal allografts. Spermatogenesis has been studied in eight chronic uremic patients on hemodialysis and in 11 recipients of well-functioning renal allografts. Sexual activity, semen analysis and testicular biopsy are abnormal in chronic uremic patients. Spermatogenesis remains "arrested" even when uremia is well controlled by intermittent hemodialysis. Marked improvement occurs in sexual performance, semen analysis and testicular biopsy after successful kidney transplantation. Immunosuppressive treatment, at dosages used six months after allografting, does not appear to affect male fertility adversely.


Report on controlled therapeutic trials in progress registered by the Information Office of the Committee on Controlled Therapeutic Trials of the UICC.


Probit analysis of clinical data as a means for comparing antibiotic efficacies.


The meiotic behavior of the Drosophila oocyte.


The origin of bone cells.

The origin of bone cells.


Virus uptake, cell wall regeneration, and virus multiplication in isolated plant protoplasts.


Scanning the interior of living brain by impedography.


Preparation and characterization of temperate, non-inducible bacteriophage P2 (host: Escherichia coli).


Behavioral reflexes in Rana catesbeiana and Rana clamitans with large skin grafts.


Cellular differentiation in the thymus. II. Thymus-specific antigens in rat thymus and peripheral lymphoid cells.


In the wisdom of Congress.

In the wisdom of Congress.


Relationship of socioeconomic status and preference for symptoms in a role-playing situation.


Constantin von Monakow (1853-1930), neurobiologic philosopher.


Nathaniel Chapman (1780-1853), first president of the American Medical Association.


Changes in leptomonads of Leishmania tropica grown in media containing immune serum.


Rotation flap skin graft.

Rotation flap skin graft.


Comparison of the partial amino-acid sequence of dogfish trypsinogen with bovine trypsinogen.


Ferrokinetics in man.

Ferrokinetics in man.


Failure of some bacterial enzymes to increase decalcification and permeability of enamel exposed to lactic acid.


Factors influencing cholesterol biosynthesis in rat liver.


Advances in the clinical and laboratory evaluation of renovascular hypertension.


Sexual differences in the protein content of the hypothalamus in rats.


Rudolf Virchow and his friends Heinrich Schliemann and Salomon Neumann.


Mycoplasmas as contaminants and their detection.


Clinical trial of new attenuated mumps virus vaccine (Jeryl Lynn strain): preliminary report.


Phenolization of smallpox vaccine.

Phenolization of smallpox vaccine.


Principles of clinical control of viral vaccines.


Continuous production of highly purified Clostridium tetani toxin.


The theory and practice of plaque counting in the bioassay of virus infectivity.


Serum CPK and dolase activity in man following controlled administration of psychotomimetic drugs.


The action of ionizing radiation on transcription (and translation) in several strains of Escherichia coli.


The modification of post-irradiation DNA degradation in Escherichia coli B/r.


Effect of hypoxia, irradiation, and bone marrow transplantation on erythropoietin levels in mice.


Experimental therapy of intestinal radiation reactions in patients undergoing abdominal irradiation.


Clinical evaluation of rubella vaccine, Cendehill strain.


Reticulum cell sarcoma presenting as a vulvar lesion.


Index Medicus--abridged.

Index Medicus--abridged.


Prolongation of heterotopic cardiac allografts in dogs by topical radiation.


Evaluation of strain-specific effects in the immunosuppressive action of heterologous antithymus sera in mice.


The preparation and properties of antisera to subcellular fractions from lymphocytes.


Pathogenesis, differentiation and management of hypertriglyceridemia.


The role of catecholamines in circulatory diseases.


Dysphagia.

Dysphagia.


Drugs and the liver: a review of metabolism and adverse reactions.


Pathophysiology of sprue syndromes.

Pathophysiology of sprue syndromes.


Rationale for the selection of chemotherapeutic agents.


Disseminated intravascular coagulation.

Disseminated intravascular coagulation.


Drug--induced bone marrow injury.

Drug--induced bone marrow injury.


Diseases of maturation of the lymphoid system.


Clinical usefulness of thoracic duct cannulation.


Pulmonary vascular resistance.

Pulmonary vascular resistance.


Curable hypertension.

Curable hypertension.


Clinical notes on the illness and death of President Franklin D. Roosevelt.


Medicine in history.

Medicine in history.


An averaged electroencephalic auditory diagnostic (AEA-D) procedure.


Innominate artery hemorrhage complicating tracheotomy.


Albert C. Furstenberg, M.D. 1890-1969.

Albert C. Furstenberg, M.D. 1890-1969.


Biologically active compounds containing 2,3-dihydroxybenzoic acid and serine formed by Escherichia coli.


Metabolic basis of platelet phagocytosis.


Control of xylose metabolism in Escherichia coli.


Gene photoinactivation in Escherichia coli which contain 5-bromodeoxyuridine-substituted DNA.


Dinucleotide production by DNA polymerase.


Studies with the RNA polymerase. 3. Enzymatic activity of the monomer form.


Circular dichroism of valine and formylmethionine transfer RNA from Escherichia coli: effect of aminoacylation.


Purification and properties of peptidyl-tRNA hydrolase from Escherichia coli.


Substrate specificity of ribosomal peptidyl transferase. II. 2'(3')-O-aminoacyl nucleosides as acceptors of the peptide chain in the fragment reaction.


Effect of polyriboinosinic acid on RNA chain initiation.


Inhibition of polyriboadenylate polymerase activity in Escherichia coli by infection with amber mutants of phage T4.


Improvement of leukocyte bactericidal activity in chronic granulomatous disease.


Paul M. Aggeler, M.D.

Paul M. Aggeler, M.D.


Granulocytic sarcoma (chloroma).

Granulocytic sarcoma (chloroma).


Testosterone-induced depletion of thymus and marrow lymphocytes as related to lymphopoiesis and hematopoiesis.


Research in the field of psychiatry.

Research in the field of psychiatry.


Sir Lawrence Bragg, FRS.

Sir Lawrence Bragg, FRS.


Pituitary and hypothalamic endocrine changes associated with reproductive development of Holstein bulls.


Thymineless death in Escherichia coli: deoxyribonucleic acid replication and the immune state. Thymineless death (TLD) and nalidixic acid (NA) inactivation were studied in multiple auxotrophic strains of Escherichia coli B and B/r. As expected, it was found that both E. coli B and B/r exhibited an "immune state," i.e., a fraction of the population survived inactivation to both TLD and NA. With glucose as a carbon source in minimal medium, 0.1 to 0.3% of strain B and 0.2 to 0.5% of strain B/r survived inactivation; with acetate as the carbon source, the surviving fractions were increased to 1 to 2% and 5 to 7%, respectively. These immune fractions could be increased in magnitude by preincubation in minimal media containing thymine. Systematic analysis of the particular supplements necessary for the immune state indicated that the absence of the required amino acids was essential for the maximal expression of immunity. However, immunity was not abolished in acetate medium even in the presence of the required supplements. Further studies on the replication of deoxyribonucleic acid (DNA) during preincubation indicated that the degree of immunity did not necessarily correlate with the completion of a round of DNA replication. This finding was supported by examining the immune state in synchronous populations. In both glucose and acetate medium, there was no significant change in the degree of immunity to inactivation within the cell cycles of E. coli B and B/r. We concluded that some other event, possibly inhibition of protein synthesis, was necessary in determining the degree of the immune state. DNA replication was investigated after TLD and NA inactivation, and, as expected, it was found that both events led to premature initiation of replication. The only differences observed in the effects of these two processes on DNA synthesis were the following. (i) NA-induced replication was less sensitive to chloramphenicol than was TLD. (ii) TLD-induced replication was unaffected by pretreatment of the cells with mitomycin C, but this pretreatment prevented the replication of DNA after NA treatment. It was suggested that the mechanism of action of NA could involve a monofunctional attack on the DNA.


Pyrimidine pools and macromolecular composition of pyrimidine-limited Escherichia coli. The growth rate of a pyrimidine-requiring strain was controlled by limiting the concentration of exogenous orotic acid. As the steady state, pyrimidine-limited growth rate was decreased, the intracellular pyrimidine pools and the total nucleic acid per unit mass of culture also decreased. The ratio of deoxyribonucleic acid to protein remained constant, whereas the ratio of ribonucleic acid to protein decreased 30% over a threefold variation in growth rate (50- to 150-min doubling times). The intracellular uridine triphosphate and cytosine triphosphate pools also decreased (although not coordinately), and the pyrimidine biosynthetic enzymes were derepressed. Cell size was unaffected by pyrimidine-mediated variation of the growth rate.


Biochemical characterization of sulfur assimilation by Salmonella pullorum. The biochemical basis for a cysteine requirement in Salmonella pullorum strain MS35 is presented. Before determining the missing biochemical functions, it was established that the assimilatory sulfate-reducing pathway for this species is an inorganic one in which 3'-phosphoadenylylsulfate (PAPS), sulfite, and sulfide are intermediates. A requirement for 2'- and 3'-adenosine monophosphate was found for in vitro synthesis of PAPS, possibly because 2'- and 3'-adenosine monophosphate inhibits endogenous nucleases that destroy PAPS. The cysteine requirement of strain MS35 was attributed to a defect at 37 C in sulfate permeation and temperature sensitivity in sulfite reduction. At 25 C, sulfite was metabolized to sulfide. A novel property of sulfate-utilizing revertants was their unselected ability to assimilate thiosulfate sulfur at 25 C but not at 37 C.


Early host damage in the infection cycle of Bdellovibrio bacteriovorus. The effects of bdellovibrio infection on host permeability and respiration were investigated by measuring respiration rates and the rate of o-nitrophenyl-beta-d-galactopyranoside hydrolysis during the course of single infection cycles of Bdellovibrio bacteriovorus strain 109 growing on Escherichia coli ML 35 (lac i(-)z(+)y(-)). The data show that among the very early consequences of parasite attack on the host are an increase in permeability and a general disruption of respiratory activity of the host, and it is suggested that both phenomena stem from early damage to host membrane. The rapid onset of damage after inception of the cycle and the failure of streptomycin to prevent the damage indicate that complete penetration of the parasite into the host is not a requirement for the observed effects. The data also show that bdellovibrio does not use host energy-generating mechanisms for its growth and suggest that the parasites may have a search mechanism that permits them, to some degree, to distinguish between infected and uninfected hosts.


Isolation and partial characterization of Escherichia coli mutants with altered glycyl transfer ribonucleic acid synthetases. Isolates with mutations in glyS, the structural gene for glycyl-transfer ribonucleic acid (tRNA) synthetase (GRS) in Escherichia coli, are frequently found among glycine auxotrophs. Extracts of glyS mutants have altered GRS activities. The mutants grow with normal growth rates in minimal media when high levels of glycine are provided. No other metabolite of a variety tested is capable of restoring normal growth. The glyS mutants fail to make ribonucleic acid (RNA) when depleted of exogenous glycine in strains which are RC(str) but do so when the cells are RC(rel). In contrast, biosynthetic mutants which are unable to synthesize glycine (glyA mutants) do not make RNA when deprived of glycine even if they are RC(rel); in this case, RNA is synthesized upon glycine deprivation only when the nucleic acid precursors made from glycine are provided in the medium. The level of serine transhydroxymethylase is unaltered in extracts of any of the glyS mutants, even though the level of charged tRNA(Gly) is at least 20-fold lower than that found in a prototrophic parent; this indicates that, if there is control over the synthesis of serine transhydroxymethylase, it is not modified by reduced levels of charging of the major species of tRNA(Gly).


Characterization of altered forms of glycyl transfer ribonucleic acid synthetase and the effects of such alterations on aminoacyl transfer ribonucleic acid synthesis in vivo. The glycyl transfer ribonucleic acid (tRNA) synthetase (GRS) activities of several Escherichia coli glyS mutants have been partially characterized; the K(m) for glycine and the apparent V(max) of several of the altered GRS differ significantly from the parental GRS. Paradoxically, some of the altered forms exhibit more activity in vitro than the GRS from a prototrophic strain (GRS(L)); several parameters of these activities have been studied in an attempt to resolve this problem. The amount of acylated tRNA(Gly) in vivo was examined to assess the GRS activities inside the cells. During exponential growth in media containing glycine, moderate amounts of acylated tRNA(Gly) occur in the glyS mutants; glycine deprivation leads to a dramatic drop in the amount of acylated tRNA(Gly). An alternative measure of the in vivo activities of the altered enzymes is the efficiency of suppression of the trpA36 locus by su(36) (+); glyS mutants grown with added glycine exhibit one-third to one-fourth the suppression efficiency of the prototrophic glyS(H) parent, presumably because they are less efficient, even in the presence of high levels of glycine, in charging the tRNA(Gly) species which functions as the translational suppressor.


Some biological effects of carbamoyloxyurea, an oxidation product of hydroxyurea. Carbamoyloxyurea, an oxidation product of hydroxyurea, is bactericidal for Escherichia coli. Drug-induced killing is independent of cellular metabolism; ribonucleic acid and protein syntheses are the processes most affected, and the lethal action is accompanied by degradation of cellular deoxyribonucleic acid. In all of these effects the drug differs from hydroxyurea, a primarily bacteriostatic agent that inhibits deoxyribonucleic acid synthesis, whose lethal action ultimately depends on cellular activity.


Thymineless death in Escherichia coli 15T- and recombinants of 15T- and Escherichia coli K-12. Thymineless death was examined in Escherichia coli 15T(-) and recombinants of 15T(-) and E. coli K-12. Those strains that were very sensitive to thymine deprivation were also very sensitive to a variety of inducing agents (mitomycin C, ultraviolet light, hydroxyurea, and nalidixic acid). Those strains that were relatively resistant to thymineless death were also relatively resistant to the inducing agents. After exposure to thymineless death and the inducing agents, sensitive strains lysed, produced colicin, and had phage particles in their lysates. These strains also showed an increase in the 6-methyladenine content of their deoxyribonucleic acid (DNA) and an increase in the DNA methylase activity of their crude extracts under these conditions. None of these effects was noted in the strains relatively resistant to thymineless death and the inducing agents. These data indicate that there are two types of thymineless death. One is represented by the strains that are very sensitive to thymine deprivation and other inducing agents and is secondary to the induction of phage psi. The strains more resistant to thymine deprivation and the other inducing agents undergo a non-phage-mediated thymineless death. The mechanism of this latter process is currently under study.


Formation and ultrastructure of extra membranes in Escherichia coli. A temperature-sensitive strain of Escherichia coli (strain 0111a(1)) was shown to accumulate membranous structures at 40 C. These "extra membranes" appeared as vesicles or whorls (or both), depending on the time of growth at 40 C. After 2 hr of growth at 40 C, only vesicles were observed in E. coli 0111a(1) cells; both vesicles and whorls were apparent after 6 hr. The number of cells which contained both types of extra membrane reached a maximum value (75%) after 10 hr of growth at 40 C. Extra membrane production was also studied by using temperature shifts. In shift-up experiments, cells grown at 30 C into early stationary phase accumulated extra membrane after a shift to 40 C. The percentage of E. coli 0111a(1) cells containing extra membrane decreased significantly after a shift from 40 to 30 C. Phase- and electron-microscopic observations indicated that E. coli 0111a(1) cells grown at 40 C were larger than E. coli 0111: B(4) cells grown at either temperature. The ratio of optical density per cell and cell measurements obtained from quantitative electron microscopy confirmed that E. coli 0111a(1) cells grown at 40 C were about twice as large. Microdensitometer traces indicated that the dimension of a single membrane of either whorls or vesicles was 5.4 nm in peak-to-peak distance (8.8 nm total thickness).


Purification of phosphomannanase and its action on the yeast cell wall. An improved assay for phosphomannanase (an enzyme required for the preparation of yeast protoplasts) has been developed based on the release of mannan from yeast cell walls. A procedure for the growth of Bacillus circulans on a large scale for maximal production of the enzyme is described. The culture medium containing the secreted enzyme was concentrated, and the enzyme was purified by protamine sulfate treatment, ammonium sulfate fractionation, gel filtration on P-100, and isoelectric density gradient electrophoresis. Although the enzyme was purified to apparent homogeneity, it still contained laminarinase activity which could not be separated by size or charge. The two enzymatic activities also exhibited two isoelectric points (pH 5.9 and 6.8) on ampholine electrophoresis. The laminarinase was not active on yeast glucan. The enzyme preparation was shown to remove mannan from yeast without removing glucan. Electron microscopic observation supports the idea that this mannan is the outer layer of the yeast wall. Phosphomannanase will produce protoplasts from yeast when supplemented with relatively low amounts of snail enzyme. This activity is present in snail enzyme but appeares to be rate-limiting when snail enzyme alone is used. Phosphomannanase has proven useful for studying the macromolecular organization of polymers in the yeast cell wall.


Behavior of coliphage lambda in hybrids between Escherichia coli and Salmonella. Salmonella typhosa hybrids able to adsorb lambda were obtained by mating S. typhosa recipients with Escherichia coli K-12 donors. After adsorption of wild-type lambda to these S. typhosa hybrids, no plaques or infective centers could be detected. E. coli K-12 gal(+) genes carried by the defective phage lambdadg were transduced to S. typhosa hybrids with HFT lysates derived from E. coli heterogenotes. The lysogenic state which resulted in the S. typhosa hybrids after gal(+) transduction differed from that of E. coli. Ability to produce lambda, initially present, was permanently segregated by transductants of the S. typhosa hybrid. S. typhosa lysogens did not lyse upon treatment for phage induction with mitomycin C, ultraviolet light, or heat in the case of thermoinducible lambda. A further difference in the behavior of lambda in Salmonella hybrids was the absence of zygotic induction of the prophage when transferred from E. coli K-12 donors to S. typhosa. A new lambda mutant class, capable of forming plaques on S. typhosa hybrids refractory to wild-type lambda, was isolated at low frequency by plating lambda on S. typhosa hybrid WR4254. Such mutants have been designated as lambdasx, and a mutant allele of lambdasx was located between the P and Q genes of the lambda chromosome. Plaques were formed also on the S. typhosa hybrid host with a series of lambda(i21) hybrid phages which contain the N gene of phage 21. The significance of these results in terms of Salmonella species as hosts for lambda is discussed.


Induction of dimorphism in the basidiomycete Lenzites saepiaria. Sugars can serve as the germinant for basidiospores of the wood-rotting fungus Lenzites saepiaria. Hexoses sterilized by autoclaving were better germinants than hexoses that were sterilized by filtration. The degradation products in heated hexose which were responsible for the stimulation of germination were levulinic and formic acid. Another product of hexose degradation, hydroxymethyl furfural, had a marked effect on outgrowth of L. saepiaria basidiospores and on the development of mycelia. Basidiospores that germinated in the presence of hydroxymethyl furfural yielded large rounded bodies that, in some cases, developed as a chain of yeastlike cells. Addition of hydroxymethyl furfural to developing mycelia resulted in the production of chains of round yeastlike structures. Similar results were obtained by treating basidiospores or mycelia with phenethyl alcohol.


Facilitation of the transfer of R factor by the resident R factor. Transfer of some R factors were shown to be facilitated by resident R factors. The sex factor itself may be responsible for this phenomenon.


Plasmid formation after lambda bacteriophage infection of Escherichia coli-Salmonella typhosa hybrids. Defective phage lambdadg, when present in certain Salmonella typhosa hybrids, could be eliminated with acridine orange or ethidium bromide treatment. The lambdadg deoxyribonucleic acid could be separated from the S. typhosa host deoxyribonucleic acid as a distinctly covalently closed molecule.


Resistance transfer to the resident intestinal Escherichia coli of rats. The transfer of resistance factors from introduced donor cells to the resident intestinal Escherichia coli flora of conventional rats was tested.


Induction of filament formation and thymineless death in Escherichia coli K-12. The study of isogenic strains of Escherichia coli K-12 carrying mutations which control filament formation after ultraviolet irradiation showed that there is not necessarily a relationship between filament formation and thymineless death.


Comparative study of isoenzyme formation of bacterial beta-galactosidase. The enzyme beta-galactosidase was studied in crude extracts of Escherichia coli 3300, E. coli grown on a selenium and sulfur medium, Salmonella typhimurium F-lac, Serratia marcescens F-lac, S. marcescens P-lac, Proteus mirabilis F-lac, P. mirabilis P-lac, Aeromonas formicans, and Streptococcus lactis. The isoenzymes could be demonstrated by an alternative histochemical technique. Different isoenzyme patterns were found to be determined by the beta-galactosidase structural gene and not by the cytoplasm within which the beta-galactosidase was formed. In addition, the beta-galactosidases from strains which form isoenzymes were more stable to heat and urea treatments than the enzyme formed by those organisms which produce reduced amounts of, or no, isoenzyme.


Ultraviolet irradiation of the vegetative cells of Dictyostelium discoideum. Experiments on the effect of ultraviolet (UV) light on the survival of vegetative Dictyostelium discoideum cells indicate that this is a relatively UV-resistant organism. Several factors suggest the presence of some type of repair process. Experiments to test for liquid-holding recovery and simple photoreactivation yielded negative results. Acriflavine and caffeine were utilized to possibly interfere with dark repair. Acriflavine produced no UV sensitization, but caffeine did cause a concentration-dependent decrease in survival of irradiated cells. When UV-irradiated cells were illuminated with photoreactivating light while suspended in caffeine, the survival increased above that for cells treated with caffeine alone, suggesting an overlap between lesions repaired by photorepair and dark repair. Growth experiments showed that UV light induced a dose-dependent division delay, followed by a period of retarded growth characterized by the presence of a constant fraction of nonviable cells in the irradiated population. The delayed exposure of cells to caffeine after irradiation showed that the magnitude of the caffeine sensitization diminished throughout the division-delay period. An action spectrum indicated probable nucleoprotein involvement in the induction of division delay. UV light retarded ribonucleic acid and protein synthesis and temporarily blocked deoxyribonucleic acid synthesis. However, synthesis of all three accelerated prior to the end of the division-delay period and then closely paralleled the increase in cell number.


Studies of immunosuppressive potency of rabbit antimouse antisera raised in response to various murine tissues.


Usefulness of the hemagglutination test using Treponema pallidum antigen (TPHA) for the serodiagnosis of syphilis.


The hepatic response to endotoxin shock; hemodynamic and enzymatic observations.


Infectious megaenteron of mice. II. Detection of coliform organisms of an unusual biotype as the primary cause.


Extended schizogony of Eimeria mivati in betamethasone-treated chickens.


Larvae of the Ixodes ricinus complex of species.


The penetration of human epidermal sheets by the cercariae of Schistosoma mansoni and the collection of schistosomula.


Clinical and experimental aspects of sulphobromophthalein and related compounds.


Vitamin B12 and the liver.

Vitamin B12 and the liver.


Recent progress in the hepatic porphyrias.


Computer-oriented laboratory testing of hepatic status.


Neonatal jaundice.

Neonatal jaundice.


The bilirubin shunt and shunt hyperbilirubinemia.


Management of acute liver damage in man.


The management of fulminant hepatic failure.


Immunologic aspects of liver diseases.

Immunologic aspects of liver diseases.


Nonsuppurative destructive chronic cholangitis and chronic hepatitis.


Anti-inflammatory treatment of chronic active liver disease.


Some effects of ethanol on normal and pathologic livers.


Liver diseases and diabetes mellitus.

Liver diseases and diabetes mellitus.


Liver injury induced by aflatoxin.

Liver injury induced by aflatoxin.


Traumatic liver injuries.

Traumatic liver injuries.


Hepatic angiography.

Hepatic angiography.


Umbilico-portal catheterization in diagnosis of liver disease.


Hepatic disease in animals.

Hepatic disease in animals.


Protracted ambulatory infusion cancer chemotherapy of the liver and biliary system.


Transplantation of the liver.

Transplantation of the liver.


The normal hepatocyte in division: regeneration of the mammalian liver.


Recent advances in the mechanism of hepatic carcinogenesis.


The influence of hormones on hepatic function.


Recent progress in the study of liver culture.


The production of chloramphenicol acetyltransferase by bacteriophage P1CM.


Properties of P22 and a related Salmonella typhimurium phage. 3. Studies on clear-plaque mutants of phage L.


Stages in phage R17 infection. II. Ionic requirements for phage R17 attachment to F-pili.


Stages in phage R17 infection. 3. Energy requirements for the F-pili mediated eclipse of viral infectivity.


Localization of a Mycoplasma-like organism in tissues of a leafhopper vector carrying clover phyllody agent.


The metabolism of T4 phage ghost-infected cells. I. Macromolecular synthesis and ransport of nucleic acid and protein precursors.


Protein synthesis and the inhibition of host messenger ribonucleic acid production in bacteriophage T4-infected Escherichia coli.


Plating of lambda derivatives on an Escherichia coli-Salmonella typhosa hybrid.


Rapid bacteriophage sedimentation in the presence of polyethylene glycol and its application to large-scale virus purification.


Mutual relations of colicinogenic factors and resistance determinants in Escherichia coli.


New species of bifid bacteria from Apis mellifica L. and Apis indica F. A contribution to the taxonomy and biochemistry of the genus Bifidobacterium.


Comparison of paired midstream-voided and catheterization urine samples from the postpartum clinic population.


Review of 40 histologically proven cases of epithelial downgrowth following cataract extraction and suggested surgical management.


Mortality in association with ophthalmic surgery.


Fetal gastrointestinal obstruction. Prenatal diagnosis based on amniotic fluid analysis.


A compact indirect ophthalmoscope providing an erect aerial image.


Eugene Maurice Blake 1882-1969.

Eugene Maurice Blake 1882-1969.


Leuman M. Waugh receives William John Gies award.


Primary incompetance of the gastric cardia.


Ruptured arteriosclerotic abdominal aortic aneurysms. A pathologic and clinical study.


Surgical considerations in the management of lesions of the profunda femoris artery.


A survey of the acute toxicity of elemental fluorine.


Intermittent cuff inflation during prolonged positive-pressure ventilation.


Functional restoration of decompensated ureters in children.


Controlled normocarbia during IPPV with the Emerson anesthetic ventilator.


Noise-induced hearing loss. Exposures to steady-state noise.


Does prayer preserve?

Does prayer preserve?


Wains and Wainwrights. Wagon making as an occupation.


Information technologies and health care. 4. The need for new technologies to support planning and management.


Cellular hypersensitivity in the cornea. An analysis of the limbus and limbal cellular infiltration by light and electron microscopy.


Physiological chemistry of the eye.

Physiological chemistry of the eye.


Semiautomated method for serum pepsinogen determination.


Steroid diabetes in the guinea pig. Studies on islet-cell ultrastructure and regeneration.


Over-all therapeutic usefulness of glybenclamide, a new hypoglycemic sulfonylurea.


Current concepts of albumin metabolism. A review.


Electrophoretic heterogeneity and relationships of pepsinogens in human urine, serum, and gastric mucosa.


Effect of combinations of histamine and pentagastric on gastric-secretion in man and dog.


Effect of prolonged aministration of parietal cell antibodies from patients with atrophic gastritis and pernicious anemia on the parietal cell mass and hydrochloric acid output in rats.


In memoriam: Robert Kho-Seng Lim, M.B., Ch.B., Ph.D., D.Sc., 1897-1969.


Organelle pathology of the liver. The endoplasmic reticulum.


Maimonides (1135-1204).

Maimonides (1135-1204).


Accrediated dental schools.

Accrediated dental schools.


Dr. Diefenbach named to ADA dental health post.


Ultrastructural changes associated with germination and outgrowth of an appendage-bearing clostridial spore. The sequence of events occurring during the germination and outgrowth of appendage-bearing spores of Clostridium bifermentans was studied by phase-contrast and electron microscopy. The mature spore was characterized ultrastructurally as having the normal spore components as well as long tubular appendages which orginated from the surface of the spore coat. Spores were incompletely enclosed by a distinctly laminated exosporium which possessed hairlike projections on its outermost layer. During germination, structural changes were observed in the core, core wall, cortex, and spore coat layers. Cortical material was extruded from the spore during outgrowth, which usually occurred from the pole opposite the appendages. The subunits comprising the structure of the appendages and the morphology of the mature appendages were observed. No discernible changes could be observed in the spore appendages during germination and outgrowth.


Stability and comparative transport capacity of cells, mureinoplasts, and true protoplasts of a gram-negative bacterium. The outer layers of the cell envelope of a pseudomonad of marine origin were removed by washing the cells in 0.5 m NaCl followed by suspension in 0.5 m sucrose. The term mureinoplast has been suggested for the rod-shaped forms which resulted from this treatment. As previously established, these forms lacked the outer cell wall layers but still retained a rigid peptidoglycan structure. Mureinoplasts remained stable if suspended in a balanced salt solution containing 0.3 m NaCl, 0.05 m MgSO(4), and 0.01 m KCl but, unlike whole cells, lost ultraviolet (UV)-absorbing material if suspended in 0.5 m NaCl or 0.05 m MgCl(2). Sucrose added to the balanced salt solution also enhanced the loss of UV-absorbing material. Addition of lysozyme to suspensions of mureinoplasts in the balanced salt solution produced spherical forms which, by electron microscopy and the analysis of residual cell wall material, appeared to be true protoplasts. Only undamaged mureinoplasts, as judged by their capacity to fully retain alpha-aminoisobutyric acid, were capable of being converted to protoplasts. Protoplasts and undamaged mureinoplasts retained 100% transport capacity when compared to an equal number of whole cells. The Na(+) requirement for transport of alpha-aminoisobutyric acid and the sparing action of Li(+) on this Na(+) requirement were the same for both protoplasts and whole cells. These observations indicate that, in this gram-negative bacterium, the cell wall does not participate in the transport process though it does stabilize the cytoplasmic membrane against changes in porosity produced by unbalanced salt solutions. The results also indicate that the requirements for Na(+) for transport and for the retention of intracellular solutes are manifested at the level of the cytoplasmic membrane.


Effect of glycine on thiazole biosynthesis in Escherichia coli. Glycine was found to replace thiamine thiazole for the growth of the thiazoleless mutant of Escherichia coli; it also stimulated the production of thiamine thiazole by washed cell suspensions of the mutant.


Glycolate uptake by mutant strains of Escherichia coli K-12. Mutant strains of Escherichia coli K-12 were shown to be impaired in their ability to assimilate glycolate-2-(14)C. One strain (Glc-103) has lost the ability to oxidize glycolate; another strain (Glc-102) was relatively impermeable to the compound. A third strain (Glc-104) had undergone a similar loss in permeability, and, in addition, was deranged in the synthesis of either glyoxylate reductase or malate synthase G.


Effect of the thiol-oxidizing agent diamide on the growth of Escherichia coli. Oxidation of glutathione within Escherichia coli cells by diamide, (CH(3))(2)NCON=NCON(CH(3))(2), stops growth but does not cause cell death. Normal growth rates are resumed after periods which vary in length according to the diamide concentration. Consumption of excess reagent with added glutathione quickly reverses the inhibition. Another thiol-oxidizing agent, azoester, C(6)H(5)N=NCOOCH(3), causes lysis.


Isolation and characterization of a mutant of Escherichia coli blocked in the synthesis of putrescine. A mutant of Escherichia coli is described which is defective in the conversion of arginine to putrescine. The activity of the enzyme agmatine ureohydrolase is greatly reduced, whereas the activity of the other two enzymes of the pathway, the constitutive arginine decarboxylase and the inducible arginine decarboxylase, are within the normal range. The growth behavior of the mutant reflects the enzymatic block. It grows well in the absence of arginine, but only poorly in the presence of arginine. Under the former conditions, putrescine can be formed from ornithine as well as arginine, whereas under the latter conditions, because of feedback control, it can be formed only from arginine.


Potassium-dependant mutants of Escherichia coli K-12. Mutants of Escherichia coli K-12 that grow more slowly in media containing low concentrations of K have been isolated. All independent mutants of this type which have been studied carry a mutation in a small region of the bacterial chromosome between the supE and gal loci. The growth rate of the mutants is the same as that of the parental strains in medium containing more than 1 mm K, but is only 50% that of the parent when the K concentration is reduced to 0.1 mm. The mutants do not appear to have a primary alteration in K transport, and are therefore referred to as K-dependent. The abbreviation kdp is proposed for this class of mutant.


Requirement of polyamines for bacterial division. Synchronous cell division in an arginine auxotroph and a histidine auxotroph of Escherichia coli was obtained after starving for the required amino acid for 1 hr. However, cell division was not synchronized after starvation for 1 hr in another arginine auxotroph. This difference is proposed to depend on differences in the concentrations of polyamines in the cells. During amino acid starvation the ratio of putrescine concentration to spermidine concentration decreased in all strains, but it recovered afterward more rapidly in the third strain than in the other two. The cells divided when the ratio returned to normal in the Arg(-) mutants. Added putrescine permitted some of the cells of the first two mutants to divide sooner after amino acid starvation and thus eliminated synchrony. Spermidine added alone had no effect, but, when it was added together with putrescine, it restored synchronous division. Synchrony was established in the third mutant by adding spermidine after arginine starvation. Thus, both the variations in polyamine content and the effects of added polyamines suggest that the polyamines are essential in permitting cell division. We suggest that the molar ratio of putrescine to spermidine can be a critical factor for cell division. This effect of polyamines seems to be specific for cell division. Amino acid starvation does not induce delays in subsequent mass increase or deoxyribonucleic acid synthesis. Possible mechanisms of polyamine action are discussed.


Isolation of conditionally putrescine-deficient mutants of Escherichia coli. Mutants defective in the conversion of arginine to putrescine were found by screening clones from mutagenized cultures for inability to produce urea during growth in arginine-supplemented media. Two partially blocked mutants were isolated; one was deficient in arginine decarboxylase and the other was deficient in agmatine ureohydrolase. As predicted from the pattern of putrescine synthesis in Escherichia coli, these mutants were conditionally putrescine-deficient. When grown in either minimal or ornithine-supplemented media, conditions which lead to preferential utilization of the ornithine to putrescine pathway, the mutants had normal intracellular polyamine levels. However, when the mutants were placed in arginine-supplemented media, the level of intracellular putrescine was lowered markedly. Under conditions where intracellular putrescine was 1% of normal, the doubling time of the mutants was increased approximately 10%. The putrescine-deficient mutants had wild-type morphology, normal levels of protein and ribonucleic acid (RNA), and stringent amino acid control of RNA synthesis.


Base composition of deoxyribonucleic acid of the temperature-sensitive kanamycin-resistant R factor, Rts1. The buoyant density of deoxyribonucleic acid (DNA) from the temperature-sensitive R factor, Rts1, was determined by CsCl density-gradient centrifugation. Rts1 was found to consist of a single species of DNA of density 1.705 g/cm(3), which corresponds to a base composition of 45% guanine plus cytosine. This value is distinct from the densities previously reported for other R factors, suggesting that Rts1 represents a new molecular class of R factors.


Inhibition of de novo purine biosynthesis and interconversion by 6-methylpurine in Escherichia coli. The inhibition of Escherichia coli strain B and strain W-11 by 6-methylpurine depended on the formation of 6-methylpurine ribonucleotide by the action of adenine phosphoribosyltransferase (AMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.7). 6-Methylpurine ribonucleotide inhibited the de novo synthesis of purines, presumably via pseudofeedback inhibition of phosphoribosylpyrophosphate amidotransferase (EC 2.4.2.14). The same mechanism accounted for its inhibition of adenylosuccinate synthetase [IMP: l-aspartate ligase (GDP), EC 6.3.4.4]. Adenine and 6-methylaminopurine prevented inhibition by competing for the action of adenine phosphoribosyltransferase. In addition, adenine reversed this inhibition by replenishing the AMP to bypass both sites of inhibition. Nonproliferating suspensions of strain B-94, which lacked adenylosuccinate lyase (EC 4.3.2.2), converted exogenous hypoxanthine and aspartate to succinoadenine derivatives which accumulated in the medium. Compounds which inhibited adenylosuccinate synthetase inhibited accumulation of the succinoadenine derivatives. A method was described for the isolation of mutants which potentially possessed an altered adenylosuccinate synthetase.


Accumulation of a protein required for division during the cell cycle of Escherichia coli. A heat-labile protein required for division accumulates during the duplication cycle of Escherichia coli. Its formation appears to commence shortly after the cell divides, and it reaches a maximal amount shortly before the next division. A plausible mechanism for timing cell division depends on building up the critical amount of this protein. Completion of deoxyribonucleic acid (DNA) replication is also necessary for division to occur, but it does not uniquely initiate division. The evidence for these conclusions comes from heat-shock experiments; heating to 45 C for 15 min delays division increasingly with the age of a cell. A heat shock given near the end of a cycle delays division for about 30 min, whereas at the beginning of the cycle it hardly affects division. The net result is synchronization of cell division. The effect of heat is increased in bacteria which have incorporated p-fluoro-phenylalanine into their proteins. When the incorporation is early and the heat shock is late in the cycle, division is delayed by about 30 min, indicating that the division protein is synthesized early even though its sensitivity is not observed until later. At any time in the cell cycle, heat shock simply delays total protein and DNA synthesis ((3)H-thymidine uptake) for approximately 14 min. DNA replication and cell division are thus discoordinated, since DNA replication is not synchronized by the treatment.


Pathways of anaerobic acetate utilization in Escherichia coli and Aerobacter cloacae. Acetate-1-(14)C was added to anaerobic glucose-fermenting cultures of Escherichia coli and Aerobacter cloacae. In the E. coli culture, lactate formation occurred late in the fermentation, when the rate of production of formate and acetate had decreased. The occurrence of acetate label in the lactate indicated formation of pyruvate from acetyl-coenzyme A (CoA) and formate. In the A. cloacae cultures, substantial amounts of acetate label were found in the 2,3-butanediol formed. Evidence is presented that the label could have entered the diol only by conversion of formate and acetyl-CoA into pyruvate. The observed levels of radioactivity in the diol indicated that during diol formation the reaction yielding formate and acetyl-CoA from pyruvate CoA was operating close to equilibrium. The shift in metabolism from formation of acetate, ethyl alcohol, and formate to the formation of butanediol or lactate appears to be due basically to an approach to equilibrium of the pyruvate-splitting reaction, whatever the induction mechanism by which the shift is implemented.


Fertility regulation in F-like resistance transfer factors. Mutants of the R factor R100 have been isolated that mediate high-frequency transfer of the R factor during conjugation. Complementation tests revealed two classes of mutants, operator-constitutive and repressor-negative. Some of the latter class were suppressible by amber and ochre suppressors. The results support a simple model of regulation for the control of R-factor-mediated piliation.


Control of uridine diphosphate-glucose dehydrogenase synthesis and uridine diphosphate-glucuronic acid accumulation by a regulator gene mutation in Escherichia coli K-12. Uridine diphosphate (UDP)-glucose dehydrogenase, the enzyme that converts UDP-glucose to UDP-glucuronic acid, was derepressed in a mucoid (capR9) strain of Escherichia coli K-12 and repressed in a nonmucoid (capR(+)) strain. A nonmucoid mutant (strain MC 152; capR9 non-2) derived from the mucoid strain accumulated large quantities of nucleotides. Among these nucleotides, UDP-glucuronic acid was identified as well as guanosine triphosphate and an adenosine diphosphate-sugar. UDP-glucose dehydrogenase was still derepressed in strain MC 152. When the nonmucoid mutant was transduced to the wild-type state for this regulator gene (capR(+)), the transductant was found to accumulate less total nucleotides, and the accumulation of UDP-glucuronic acid was abolished. UDP-glucose dehydrogenase was repressed in the capR(+)non-2 strain but not to the same extent that it was in the capR(+) strain.


Depression of guanosine diphosphate-mannose pyrophosphorylase by mutations in two different regulator genes involved in capsular polysaccharide synthesis in Escherichia coli K-12. Mutations in a regulator gene (capR) that causes increased synthesis of capsular polysaccharide and derepressed synthesis of several enzymes involved in polysaccharide synthesis also derepress synthesis of guanosine diphosphate (GDP)-mannose pyrophosphorylase. In addition, a second mucoid mutation (capS, which maps separately from capR) also results in the derepression of GDP-mannose pyrophosphorylase. New conditions for assaying GDP-mannose hydrolyase and GDP-l-fucose synthetase permitted us to show that these enzymes are also derepressed in the capS mucoid strain. Although phosphomannose isomerase and uridine diphosphate-galactose-4-epimerase are derepressed in capR mucoid strains, they are not derepressed in capS mucoid strains. A nonmucoid mutant of a strain containing the capR9 (mucoid) allele was deficient in GDP-mannose pyrophosphorylase.


Aerobic heterotrophic bacteria indigenous to pH 2.8 acid mine water: predominant slime-producing bacteria in acid streamers. Five gram-negative bacteria, two gram-positive bacteria, and one yeast were isolated from "acid streamers" taken from acid mine water. One gram-positive rod which has been tentatively identified as a Bacillus species appeared to be the predominant organism in the streamers. This isolate produced copious amounts of extracellular polymer at 10 C in the laboratory and was considered to be the primary source of polymer in the "acid streamer" slime matrix. The organism grew slowly at pH 2.8 in mine water media, but the optimal pH was approximately 7.0.


Facultatively parasitic strain of Bdellovibrio bacteriovorus. A strain of Bdellovibrio bacteriovorus (designated strain UKi2) was isolated which was capable of growing either saprophytically in host-free medium or endoparasitically in Escherichia coli B/r. It was quantitatively determined that each bdellovibrio could develop in solid medium to produce a colony, and 65% of the cells in a late exponential-phase culture were capable of inducing E. coli B/r spheroplasts. A photomicrographic sequence of single E. coli spheroplasts containing bdellovibrios demonstrated that parasitically derived B. bacteriovorus UKi2 could develop saprophytically after release from the host cells. Strain UKi2 appears to be morphologically quite similar to previously described obligately parasitic bdellovibrios; biochemical data on this strain suggests its close relationship to some of the previously described host-independent strains of Bdellovibrio.


Ultrastructure and cell division of a facultatively parasitic strain of Bdellovibrio bacteriovorus. Some aspects of cell development and division of Bdellovibrio bacteriovorus strain UKi2 were examined by use of electron microscopic techniques. Under saprophytic and parasitic conditions of growth, the comma-shaped cells enlarge, elongate, and form helical filaments. The mechanism of division appears to consist of an asymmetrical constriction of the filamentous cell by the cytoplasmic membrane, accompanied by a breakdown of the outer layers of the cell wall in the division region. During regeneration of the cell wall, the flagellum and flagellar sheath are formed. The development of the flagellum of the daughter cell is initiated prior to separation of the newly formed cells from the filament. Observations of B. bacteriovorus UKi2 grown under saprophytic and parasitic conditions indicate that development and ultrastructure are similar in both modes of growth.


Evidence for the existence of multipotential lympho-hematopoietic stem cells in adult rat.


Density distribution analysis of in vivo and in vitro colony forming cells in bone marrow.


Differential proliferation of erythroid and granuloid spleen colonies following sublethal irradiation of the bone marrow donor.


Asymptomatic chromophobe adenoma in an eight-year-old child biopsied by stereotaxic technique and treated with cobalt-60. Case report.


The development of cutaneous and oral pigmentation in Labrador retriever fetuses (Canis familiaris).


Occlusal plane determination.

Occlusal plane determination.


The mouth examination for complete dentures: a review.


Initial retention of complete mandibular dentures.