Water and electrolyte content of human ileostomy fluid after d-aldosterone administration.


Anal sphincter pressure characteristics.


Pituitary-adrenal suppression following intrarectal administration of dexamethasone-21-phosphate.


Morphological and biochemical studies of benign recurrent cholestasis.


Idiopathic recurrent cholestasis.

Idiopathic recurrent cholestasis.


Gastric secretion tests.

Gastric secretion tests.


Loss and regeneration of the esophageal mucosa in pemphigoid.


Aortoiliac femoropopliteal obliterative arteriosclerosis. Roentgenographic evaluation.


Peripheral arteriography and lymphography.


Nephrotic syndrome in a 92-year-old woman.


Myocardial infarction among Japanese.

Myocardial infarction among Japanese.


Prevention of femoral neck fractures in the elderly. A Singapore population study.


Minor foot lesions with diabetes mellitus and peripheral vascular disease.


Social disabilities created by gait disturbances in the aged.


The older psychiatric patient and the community.


Permeability of the rectosigmoid mucosa to tritiated water in normal subjects and in patients with milk idiopathic ulcerative colitis.


Histamine content of rectal mucosa in ulcerative colitis.


Rectal reaction to injected ulcerative colitis leucocytes and plasma.


Inhibitory action of cholecystokinin on acid secretion from Heidenhain pouches induced by endogenous gastrin.


Effect of decreased levels of endogenous gastric tissue histamine on acid secretion and stress ulcer formation in the rat.


Histamine- and insulin-stimulated gastric acid secretion after selective and truncal vagotomy.


A preliminary study of the structure and function of enlarged parotid glands in chronic relapsing pancreatitis by sialography and biopsy methods.


Serum bilirubin studies in patients with intermittent intrahepatic cholestasis.


Miliary Crohn's disease.

Miliary Crohn's disease.


Secretory response of the human pancreas to continuous intravenous infusion of secretin.


Incidence of perforated duodenal and gastric ulcer in Oxford.


Hookworm disease and duodenal ulceration.


A general method for estimating the properties of antacids.


Technique of retrograde colonic intubation and its initial application to high colonic biopsy.


Analysis of 400 examinations using the gastrocamera.


Phonoenterography: the recording and analysis of bowel sounds.


On the use of antigenic relationships among species for the study of molecular evolution. I. The lens proteins of the agnatha and chondrichthyes.


Designing sanitation standards to benefit the public.


Costs and rate of labor turnover in a hospital dietary department.


Ready-prepared vs. conventionally prepared foods. Comparisons of acceptability, food costs, and direct labor costs.


Eating quality, nutritive value, and cost of ground round and hamburger.


Yield and cost of inside round of beef. Effect of short freezer storage.


Effect of microwave-vs. water-blanching on nutrients in broccoli. Chlorophylls, ascorbic acid, pH, and total acids.


Mouse isoantigens: separation of soluble TL (thymus-leukemia) antigen from soluble H-2 histocompatibility antigen by column chromatography. Mouse H-2 histocompatibility antigen has been extracted, solubilized, and partly purified from the cells of an A strain spontaneous leukemia carrying TL (thymus-leukemia) antigens. H-2 and TL. 1, 2, 3 activities were measured by inhibition of the cytotoxic effect of the corresponding isoantibodies. TL activity was associated with the H-2 active fraction obtained by solubilization and fractionation by gel filtration. TL specificity was largely separated from H-2 antigen by subsequent chromatography on DEAE Sephadex as an adjacent component in a series of fractions. The soluble H-2 antigen prepared from the leukemia cells was tested for most of the specificities determined by H-2(a) with no exceptional results. TL. 1, 2, 3 activities, measured as each component separately, were located in approximately the same position; there is no clear indication yet whether the three TL specificities are separable from one another. It appears that in addition to the close genetic linkage between the H-2 and TL loci, and their reciprocal interaction in producing H-2 and TL antigens, these antigens exhibit some similarity at the chemical level.


Mouse complement: the effect of sex hormones and castration on two of the late-acting components. The titer of late-acting complement components in sera from male mice is 8-10 times higher than the titer of sera from female mice. Using assays developed to measure the serum content of two of the late-acting components, we have shown that this difference is due to the effect of androgen and estrogen on these two late-acting complement components. These two components have been tentatively identified as C'5 and C'6. Androgen and estrogen have greater effect on C'6 than on C'5. The possibility has not been excluded that still other of the late-acting complement components are affected by androgens and estrogens. The course of homograft rejection was unchanged in mice deficient in C'5 and C'6.


Specific transplantation antigens of mouse sarcomas induced by adenovirus type 12. A specific isograft resistance against three different mouse adeno 12 sarcomas was demonstrated in mice treated with four to eight doses of viable or X-ray-killed adeno 12 mouse tumors. Whole-body X-ray irradiation with 350 R 24 hr previous to the test challenge did not abolish the resistance, indicating that it was due to a true anamnestic immune reaction. This was further proven by the finding that similar treatment with tumors of other origin did not induce any immunity, nor did the treatment with adeno 12 tumor material induce any immunity against two neoplasms of Schmidt-Ruppin-Rous viral origin. The previous report by Trentin et al. (17) that adeno 12 infection leads to a specific transplantation immunity was fully confirmed. When the specificity of this virus-induced immunity was studied it was discovered that besides adeno virus type 12, type 7 and probably type 18 also gave the same type of resistance while adenovirus type 5 did not. A contamination of the adeno 7-infected mice with adeno type 12 was excluded by testing pooled sera from these animals for anti-adeno 12 CF or HI antibodies.


Effect of anticoagulants on delayed hypersensitivity reactions.


Differentiation of arboviruses by immunoelectrophoresis.


An attitudinal objective: its measurement through the use of taxonomy II.


Cytotoxic potential of stimulated human lymphocytes. Viable and immunologically competent lymphocytes from unsensitized donors damage allogeneic tissue culture cells in the presence of phytohemagglutinin (PHA). This cytotoxicity is specific since syngeneic tissue culture cells are not at all or only slightly damaged under similar experimental conditions. In this investigation, the relation between the stimulation of human lymphocytes and their cytotoxicity was studied. Chang cells (human liver) served as target cells in all experiments. Cell damage was quantitated by measuring the release of isotope from target cells labeled with chromate-(51)Cr. The cytotoxicity of the lymphocytes was dependent on the concentration of PHA in the incubation medium. Cell damage was maximal at concentrations of 4-8 microl PHA/ml. Higher concentrations were inhibitory although aggregation was increased and no injury of the lymphocytes was noted. Stimulation of DNA and RNA synthesis in PHA-treated lymphocytes each followed dose response curves which were similar to that of cytotoxicity. In order to establish whether stimulation without mixed aggregation of lymphocytes and target cells would suffice for cytotoxicity, a series of nonagglutinating stimulants were investigated. Lymphocytes pretreated with a crude filtrate of Staphylococcus aureus for periods of 0.5-72 hr damaged Chang cells even in the absence of PHA. Lymphocytes from a tuberculin-positive donor were strongly cytotoxic after prestimulation with PPD while those from a negative donor were inactive. Moreover, strong cytotoxic effects were also obtained with lymphocytes which had been stimulated by preincubation with allogeneic lymphocytes in mixed culture. When two stimulants were applied at the same time, additive cytotoxic effects were seen. Addition of PHA to the lymphocyte/Chang cell mixtures potentiated the cytotoxicity of prestimulated lymphocytes. The cytotoxic potential of the lymphocytes was in all cases correlated to the degree of stimulation recorded as transformation into blast cells, and was independent both of the degree of aggregation and of the stimulating factor. These findings are compatible with the assumption that injury of the Chang cells reflected an immunologically nonspecific activity of lymphocytes enhanced by stimulation. The possible importance of this activity for a number of tissue-damaging immune reactions in vivo is pointed out.


Evaluation of a programmed text in six medical schools.


Attitudes of medical students and graduate students toward emotional illness and psychiatric practice.


Medical school and career performances of medical students with low medical college admission test scores.


The quantitative evaluation of student performance in the medical interview.


Estimating the quality of patient care in a pediatric emergency room.


Datagrams. Medical school expenditures for facilities construction, 1948-1965.


Performance analysis in pediatric practice: preliminary report.


The human element in medical education and medical education research.


Method for detecting intracranial arteriovenous malformation with an ultrasonic transducer using the Doppler phenomenon.


Employment and emotional disturbance.

Employment and emotional disturbance.


Is premedication necessary for minor operations?


Medical education in Germany.

Medical education in Germany.


Report on the stay of a German medical student in South Africa from August to October 1965.


Circadian periodicity in susceptibility to lidocaine hydrochloride. Separate groups of mice standardized in an alternating 12-hour-light,12-hour-dark regimen were treated with lidocaine hydrochloride every 3 hours over a 24-hour period. The results indicate a quantitative circadian periodicity with maximal convulsant activity at 2100 hours which was approximately a fourteen fold increase over the values observed at 1500 hours.


Thalamic reticular system and central grey: self-stimulation. Rats will press a bar that brings about stimulation of midline thalamic reticular, periventricular, and central grey brain regions. In the latter two regions stimulation can also cause pain or fear.


Ambiguities in the use of the term "circadian".


Medical research: NIH wants divorce from PHS.


Pattern classification by adaptive machines. Man's intelligent behavior is due in part to his ability to select, classify, and abstract significant information reaching him from his environment by way of his senses. This function, pattern recognition, has become a major focus of research by scientists working in the field of artificial intelligence. At the lowest level, pattern recognition reduces to pattern classification, which consists of the separation, into desired classes, of groups of objects, sounds, odors, events, properties, and the like; the separations are based on sets of measurements made on the entities being classified. The pattern classifier is composed of a data filter and a categorizer. The data filter selects the distinguishing features and represents them as sets of real numbers; each set is termed a pattern. The categorizer assigns each pattern to one of several desired classes. Patterns can be represented geometrically as points in an n-dimensional space; the n coordinates of each point are the numerical values of the features selected to represent the pattern. A pattern classification system separates an n-dimensional space into regions, each of which ideally contains points of only one class. One method to effect this separation is by means of ldquo;trainablerdquo; categorizers-major components of adaptive machines. They consist of networks whose internal parameters are varied according to a set of fixed rules during a training cycle. A statistically large sample of known patterns are presented, one at a time, to the networks; internal corrections are made each time a pattern is erroneously classified. Classifica-tion performance tends to improve as the set of known patterns is cycled repetitively through the machine. Finally, the adequacy of adaptation is tested by a separate set of similar patterns which have not been used in the training process. A number of different machine organizations and training rules have been developed and are being applied successfully to numerous classification problems. More difficult recognition problems requiring the aid of logioal tests and analysis, search and association, use the digital computer programmed to supplement the functions of the adaptive classifier.


Oxygen-18 variations in sulfate ions in sea water and saline lakes. A new method measures the oxygen-isotopic composition of dissolved sulfate ions and barium sulfate. Sulfate ions in the oceans are enriched in oxygen-18 by 9.5 per mille relative to mean ocean water and show only minor variations, probably because the exchange rate with water is slow enough to prevent local equilibrium with surface waters. Sulfate ions in saline lakes and brines have oxygen-18 enrichment of from 7 to 23 per mille relative to mean ocean water;the value of the highest enrichment observed is about the same as that of atmospheric oxygen.


Sex attractants in frass from bark beetles.


Osmotic mechanism and negative pressure. When solute molecules are confined, they exert a positive pressure on the barrier. If this is simply the free solvent surface, balance of forces requires the solvent to attain an equal negative hydrostatic pressure. This offers a sufficient explanation for the reduction of the vapor pressure over a solution.


Cytokinins in the soluble RNA of plant tissues. The cytokinin, N(6)-(Delta(2)-isopentenyl) adenosine occurs in the soluble RNA of yeast and mammalian tissue and has now been detected in plant soluble RNA. A hydroxylated derivative of this cytokinin 6-(cis-4-hydroxy-3-methylbut-2-enylamino)-9-,beta-D-ribofuranosylpurine has also been identified as a constituent of plant soluble RNA.


Hominid humeral fragment from early Pleistocene of northwestern Kenya. The distal end of a hominoid humerus was recovered from early Pleistocene sediments in the Kanapoi drainage near the southern end of Lake Rudolf. Lava capping the sediments yielded a potassium/argon date of 2.5 million years. The fragment can be distinguished on inspection from gorilla and orangutan; discriminate analysis of humeri of Homo and Pan assigns it as hominid. From other evidence we consider it more likely to represent Australopithecus s.s. than Paranthropus.


Heat inactivation of the relaxing site of actomyosin: prevention and reversal with dithiothreitol. Adenosine triphosphate and magnesium (MgATP) inhibit contraction by binding to a specific relaxing site on natural actomyosin gel. This inhibitory control site is distinct from the active sites where MgATP causes contraction. In high concentrations of MgATP, calcium triggers contraction by releasing the protein from substrate inhibition, allowing the contractile reactions to occur. Heating the protein for 5 minutes at 43 degrees C selectively inactivates the relaxing site. After this treatment, actomyosin with MgATP contracts as well without calcium as with it. That this effect of heat is prevented and reversed by dithiothreitol (an agent that reduces disulfide bonds) indicates that the structure of the relaxing site depends on certain labile sulfhydryl groups, which may be those of tropomyosin. When these are oxidized to disulfide bonds, the site loses its activity; when the disulfide bonds are reduced, the site regains its activity.


Histones in the wild-type and the anucleolate mutant of Xenopus laevis. A comparison of anucleolate mutant and wild-type tadpoles of Xenopus laevis reveals striking differences in histones. In the mutant, synthesis of histone fractions I and IIb is virtually absent and IIa is reduced, while fractions III and IV are significantly increased.


Testis-specific and sex-associated hexokinases in Drosophila melanogaster. Hexokinases of Drosophila melanogaster were investigated by starchgel electrophoresis. A hexokinase is present in both sexes during earlier stages of development, but it persists only in male adults. In addition, in this species there is a testis-specific hexokinase which is first observed during the pupal period.


Rabbit lactate dehydrogenase isozymes: effect of pH on activity. The ability of lactate dehydrogenase isozyme five from rabbit skeletal muscle to catalyze pyruvate reduction is extremely sensitive to changes of pH within the range of 6.2 to 7.8. The activity of lactate dehydrogenase isozyme one from rabbit heart is virtually unaffected by changes of pH within the same range. Isozyme five is activated by low concentrations of oxalacetate and inhibited by higher concentrations, but other substrates of the citric acid cycle have no effect.


Growth and sporulation of a pyrimidine spore color mutant of Sordaria fimicola. A nonautonomous spore color mutant of Sordaria fimicola is a pyrimidine auxotroph that produces hyaline nonviable ascospores. Uracil, uridine, and cytidine are more effective growth factors than cytosine and thymine and, in high concentrations, render the mutant self-fertile by inducing the ascospores to resume development and maturation. Crosses with the unlinked arginine non-autonomus spore color mutant st-59 yielded the double mutant st-59 pyr that requires both arginine and a pyrimidine for growth, which indicates a lack of suppression of the pyrimidine requirement by the arginine locus.


Role of enzymatic wall-softening in plant morphogenesis: hormonal induction in Achlya. Sexual hormone A, which induces antheridial branching in male strains of Achlya, also elicits a rise in cellulase. The peak of induced cellulase corresponds in time with the appearance of branches that are the male sexual organ primordia; only those strains that branch in response to the hormone show a concomitant rise in cellulase. The response to the hormone is inhibited by compounds that block protein synthesis, for example, p-fluorophenylalanine and puronmycin. Vegetative branching, induced by substrates such as casein hydrolysate, is also accompanied by a rise in cellulase.


Enzymatic solubilization of insoluble proteins at neutral pH. Insoluble epidermal proteins (possibly keratin), previously considered inert to enzyme action, were solubilized by either trypsin or chymotrypsin. Cleavage of the disulfide bonds prior to enzymatic action is not necessary. In addition, the enzymatic action on intact epidermis is not influenced by the presence or absence of endogenous lipids, soluble proteins, peptides, or amino acids. Solubilization of epidermal protein by chymotrypsin is inhibited by the supernatant solution of the homogenized epidermis.


Esterase polymorphism in natural populations of a sulfur butterfly, Colias eurytheme. Starch-gel electrophoresis of esterases of wild and laboratoryreared individuals of Colias eurytheme indicates that populations in central Texas are exceedingly variable, consisting almost entirely of heterozygotes formed from a large number of alleles at an autosomal locus controlling the production of an esterase designated EST E. Few wild individuals are genetically identical at this locus. The commonest member of the allelic series is an apparent null allele that results in no EST E activity.


Femoropopliteal arterial occlusive disease: report of 180 autogenous vein by-pass grafts.


Transferrin polymorphism and population differences in the genetic variability of chimpanzees. Genetic divergencies between chimpanzee populations, not only.between Pan panicus and Pan troglodytes but also between different groups of the latter, are revealed by typing of transferrin. In particular, differences in the incidence of polymorphic transferrins occur between the groups formed by subdividing a large captive chimpanzee colony of heterogeneous geographic origins into racial types solely on the basis of morphological traits. Genetic variability is extremely high in one of these groups, intermediate in another, and relatively low in a third, with the pattern of changing frequencies of allelic genes at the T(f) locus following the pattern of geographic distribution of the actual conspecific populations or races for which the groups are named.


The effect of complete thoracic-duct lymph diversion on gastric secretion in dogs.


Motor innervation of human thenar and hypothenar muscles in 25 hands: a study combining electromyography and percutaneous nerve stimulation.


The use of hyperbaric oxygen in experimental renal ischemia.


Massive systemic tumour embolism during pneumonectomy: successful removal by means of balloon catheter.


Synovial regeneration after synovectomy.


Successful use of the Miller-Abbott tube.


Chromosome analysis of cells in effusions from cancer patients.


Changes in renal function produced by lymphatic obstruction.


Transport of alanine, arginine and glutamic acid in the rabbit erythrocyte and reticulocyte.


Malignant transformation and maturation in non-dividing cells during polymer tumorigenesis.


Arteriography in gynecology.

Arteriography in gynecology.


Radiology in pediatric gynecology.

Radiology in pediatric gynecology.


Treatment of arterial hypertensive disease with diuretics. V. Spironolactone, an aldosterone antagonist.


Hypertension and nephrosclerosis: a reappraisal and a new theory of renal ischemia. An observation in human autopsy material showing a statistically close relationship between complicated atherosclerosis of the aorta, at or above the renal artery take-off, and nephrosclerosis of usual type (i.e. the "granular kidney" of essential hypertension) led to a study of platelet aggregates as a cause of renal lesions. The renal cortical surface is peculiarly sensitive to ischemic damage. When an embolic source, which sheds repeatedly, was placed in the thoracic aorta of rabbits, they became hypertensive. The hypertension persisted for six months, at which time the kidneys showed nephrosclerosis characterized by surface cortical lesions consisting of shrunken glomeruli and atrophical tubules, subtended by arterioles whose intimas showed fibrous thickening. It is suggested that the renal component of the hypertension so induced is transitory, serving as a trigger mechanism for sustained hypertension.


Altered thyroid function in the rat. Effects on gastric secretion and vitamin B12 metabolism.


Sodium ion in drinking water. II. Importance, problems, and potential applications of sodium-ion-restricted therapy.


Sodium ion in drinking water. I. Properties, analysis, and occurrence.


Implications for nutritional programs in multiphasic screening.


The relationship of students' experiences before and during medical school to their conceptions of professional responsibility.


Effects of human chorionic gonadotropin and human menopausal gonadotropin (pergonal) in males with oligospermia.


Social class and academic performance by medical students.


Cerebral amino acid transport in vitro. IV. The effect of inhibitors on exit from brain slices.


Undergraduate teaching in paediatrics.

Undergraduate teaching in paediatrics.


Nerve endings in methionine sulphoximine convulsant rats, a neurochemical and ultrastructural study.


Pulmonary function in sarcoidosis.

Pulmonary function in sarcoidosis.


Sexual promiscuity among students.

Sexual promiscuity among students.


Neutrons against cancer.

Neutrons against cancer.


Pacemakers for heart block.

Pacemakers for heart block.


Negotiators for hospital doctors.

Negotiators for hospital doctors.


Phlegmasia cerulea dolens.

Phlegmasia cerulea dolens.


Pathology of malaria in West Africa.

Pathology of malaria in West Africa.


Bidirectional tachycardia.

Bidirectional tachycardia.


Cerebral arterial insufficiency and oral contraceptives.


Effects of a 24-week exercise programme on normal adults and patients with previous myocardial infarction.


Primary traumatic coronary thrombosis.

Primary traumatic coronary thrombosis.


Fenfluramine overdosage.

Fenfluramine overdosage.


Today's drugs. Nalidixic acid.

Today's drugs. Nalidixic acid.


Primary amyloidosis of the renal pelvis.


Clinicopathological conference. A case of open heart surgery with inadequate perfusion of the liver. Presented at the Royal Postgraduate Medical School.


Exposure marker for angiography.

Exposure marker for angiography.


Refresher course at Queen Victoria Hospital, Melbourne, for married women wishing to return to medical practice.


Medical research in France.

Medical research in France.


Recent advances in the gastrointestinal circulation and related areas: comments on a symposium.


Bioenergetics, why?

Bioenergetics, why?


Discussion of "Rheology and the microcirculation".


Abortion bill: Restrictive amendment rejected.


Discussion of "The elastic properties of arteries in relation to the physiological functions of the arterial system".


The elastic properties of arteries in relation to the physiological functions of the arterial system.


Some applications and limitations of electromagnetic blood flow measurements in chronic animal preparations.


Discussion of "Some applications and limitations of electromagnetic blood flow measurements in chronic animal preparations".


Washout of intra-arterially injected xenon-133 from the intestine of the dog as a method for estimating blood flow.


Discussion of "Heat exchange methods in the assessment of blood flow and heat production in solid organs".


Blood flow and secretion in the stomach.


Discussion of "Blood flow and secretion in the stomach".


Discussion of "Regional adjustments of intestinal blood flow".


Autoregulation of blood flow in the intestine.


Discussion of "Intestinal vascular responses to naturally occurring vasoactive substances".


Discussion of "Autoregulation of blood flow in the intestine".


The intestinal circulation in shock.

The intestinal circulation in shock.


Discussion of "The intestinal circulation in shock".


Macrophages from tolerant rabbits as mediators of a specific immunological response in vitro.


Fractionation of encephalitogenic polypeptides from bovine spinal cord by gel filtration in phenol--acetic acid--water.


Reagin-like antibodies in rats infected with the nematode parasite Nippostrongylus brasiliensis.


A monocytogenic humoral factor released after lymph node stimulation.


Pathological changes of thymic epithelial cells and autoimmune disease in NZB, NZW and (NZB x NZW)F1 mice.


Inhibitory effect of analogues of phenylarsonate on purified 19S and 7S antibodies specific for azophenylarsonate.


The role of macrophages in the induction of antibody in x-irradiated animals.


The effect of vesicoureteral reflux on renal function in dogs.


Transfer of immunity to Ancylostoma caninum infection in pups by serum and lymphoid cells.


Calcium oxalate solubility: the effect of trace metals.


Effect of trace metals on the crystallization of calcium oxalate.


Specific antisera to myoglobin.

Specific antisera to myoglobin.


Prolonged suprapubic drainage. Canine experience with a new teflon vesical conduit.


The deterrent effect of milk fat on urinary calculus formation in milk fed rats.


Urea reabsorption from a hydroureter.

Urea reabsorption from a hydroureter.


Influence of flow rate on changes in the composition of artificial urine during transit in normal and dilated dog ureters.


Immediate resection with an end-to-end anastomosis for carcinoma of the large bowel presenting with acute obstruction.


Metachronous carcinoma of the large intestine and intestinal polyps.


Current trends in the epidemiology of cancer of the colon and rectum.


An experimental approach to adjuvant chemotherapy in carcinoma of the rectum and colon.


Laxatives and anti-diarrhoeal agents: transit studies.


Catecholamines.

Catecholamines.


The effect of 5-hydroxytryptamine on the human colon in vivo and in vitro.


Drainage operations for vagotomy.

Drainage operations for vagotomy.


The effect of neostigmine methyl sulphate on the human colon in health and in diverticulosis.


Medical problems of the emergency force for overseas. Sea transportation.


Recent experiences with the Fogarty catheter in the treatment of arterial occlusion.


Aeromedical casualty evacuation.

Aeromedical casualty evacuation.


The preparation of the force.

The preparation of the force.


The pulmonary lesion in chorion carcinoma.


The use of pool cryoglobulin factor 8 concentrate in the management of haemophilia.


Familial chronic nephritis.

Familial chronic nephritis.


Teratoma of testis.

Teratoma of testis.


The schizophrenic reaction-type in late life.


The role of the general practitioner in psychological medicine.


The relationship between quantitative measures of dementia and of degenerative changes in the cerebral grey matter of elderly subjects.


Events in dying cells.

Events in dying cells.


'V' arthrodesis of the hip.

'V' arthrodesis of the hip.


Seven cases of traumatic dislocation of the knee.


Total hip replacement.

Total hip replacement.


Allergic vasculitis due to streptococcal sensitivity.


Stimulation and suppression tests of thyroid function.


Carbamazepine.

Carbamazepine.


The exocrine pancreas and protein-calorie malnutrition.


Homozygous abnormal haemoglobins in Cape Town. A study of Hb.C disease in a white family, Hb.E disease in an Asiatic family and Hb.S disease in a coloured family.


Renal artery stenosis and the nephrotic syndrome.


Osteopoikilosis--a clinical and genetic study.


Effect of hyperthyroidism on metabolism of albumin in man.


Serum haptoglobin in cases with Starr-Edwards ball-valve prosthesis.


Absorption of hemoglobin iron in man.

Absorption of hemoglobin iron in man.


Prostatitis and its treatment.

Prostatitis and its treatment.


Chediak--Steinbrinck--Higashi's anomaly. A case report.


Treatment of acute phlebothrombosis with streptase.


Congenital convex pes valgus with vertical talus.


Regression of dietary cirrhosis in rats fed alcohol and a "super diet". Evidence of the nonhepatotoxic nature of ethanol.


Effect of four multiples of a basic mixture of essential amino acids on nitrogen retention of adult human subjects.


Plasma amino acid response to glucose administration in various nutritive states.


Metabolism of l-ascorbic-4-3H acid in man.


Hunger and satiety sensations in men, women, boys, and girls.


Parallel food classifications in developing and industrialized countries.


Vitamin E content of infant formulas and cereals.


Acute perforation of the small intestine in regional enteritis.


Small intestine studies in giardiasis.

Small intestine studies in giardiasis.


Trends in the management of the cancer patient. The president's address, 1966.


Cobalt 60 teletherapy of early carcinoma of the vocal cords.


Preservation of the larynx in the surgical treatment of cancer, recurrent after radiation therapy.


Surgical treatment of carcinoma of the cervix, recurrent after irradiation or combination of irradiation and surgery.


Transvaginal cesium 137 therapy.

Transvaginal cesium 137 therapy.


Treatment of primary adenocarcinoma of the cervix.


Opaque portal ruler for cobalt therapy. With special reference to its use with uterine cervix carcinoma.


A direct reading intracavitary dosimeter for use in radium therapy.


Embryonal rhabdomyosarcoma: five- year survival of a patient treated by radiation and chemotherapy.


The value of strontium 85 bone scanning in radiation therapy.


The treatment of bone metastases with parathormone followed by radiophosphorus.


Accuracy in measuring nodules by scanning.


Radiation induced hepatic injury; its detection by scintillation scanning.


An isodose plotter using modified isotope instruments.


A technique in testing radium sources for leakage.


The response of the gil epithelium of the adult axolotl (Siredon mexicanum) to roentgen radiation.


Allergy and infection. IV. Allergic permutations.


Hidden allergens--vehicles and excipients.


Specific and nonspecific passive desensitization. IX. The effect of diluting sensitizing doses of antiserum with normal heterologous and homologous sera.


Information sources for drug actions and reactions.


Lactic dehydrogenase and succinic dehydrogenase in psoriasis.


Special articles in an allergy journal.

Special articles in an allergy journal.


Enzymes of the glycolytic pathway in skin. 3. phosphorylase.


Enzymes of the glycolytic pathway in skin. IV. Phosphoglucose isomerase.


Changes induced by phytohaemagglutinin in guinea-pig skin in vivo.


Shear injuries of the brain.

Shear injuries of the brain. A blow to the head will impart rotational velocity to the brain and, depending on its magnitude, will produce effects ranging from concussion to profound neurological dysfunction. Resultant shear strains distort and rupture axons, blood vessels and major fibre tracts. Thirty-seven patients with head injury that was not complicated by significant hemorrhage or superficial laceration of the brain had coma or severe dementia, spastic quadriparesis, incontinence and autonomic dysfunction. These patients survived 24 hours to 243 days. Gross pathological examination revealed little, but there was microscopic evidence of axonal and small vessel injury in all; this was localized to the basal and midsagittal areas of the diencephalon and mesencephalon, particularly in those less severely injured. Such changes represent the basic pathology of all head injury. Data from this study suggest that concussion depends upon varying degrees of damage to the axon as well as the neuron. The current definition of concussion-immediate loss of consciousness with rapid and complete recovery of cerebral function-should not exclude the fact that a small number of neurons may have been permanently disconnected or have perished.


A three-year survey of the antibacterial spectra of the more commonly used chemotherapeutic agents. Eight major bacterial groups (25,000 strains) of gram-positive and gram-negative organisms which were isolated from a variety of clinical specimens were tested by the disc-plate and tube dilution procedure. The in vitro antibacterial spectra of 17 commonly used chemotherapeutic agents were recorded and evaluated statistically during a three-year period. Penicillin G, erythromycin and chloramphenicol were very effective against members of the diplococci and streptococci genera. The synthetic penicillins inhibited 99% of Staph. aureus whereas penicillin G was effective against only 45% of these strains. There was a significant increase in the number of tetracycline-resistant strains of both D. pneumoniae and the Lancefield Group A streptococci. A yearly increase in gram-negative pathogens was noted. These organisms (i.e. Escherichia, Aerobacter, Proteus, Pseudomonas) showed greater resistance to the majority of chemotherapeutic agents than did the gram-positive organisms. The percentage of susceptible strains for each bacterial group appears in the text.


Medullary sponge kidney: its occurrence in a father and daughter.


Reovirus hemagglutinins.

Reovirus hemagglutinins.


The relationship of pregnancy, vaginal candidiasis and glucose metabolism. In 72 pregnant women with culture-proved vaginal candidiasis, and an equal number of controls matched for parity, size, stage of gestation and age, the intravenous glucose tolerance curves were compared using Silverstone's method. The results in both study and control groups did not differ and resembled closely those in Silverstone's series. Half the study group were treated using nystatin alone, while the other half also received tolbutamide. The cure rate was equal in the two groups. Candidiasis in pregnancy does not appear to be related to altered glucose metabolism nor does the addition of this hypoglycemic drug (tolbutamide) improve results. No ill effects, fetal or maternal, were apparent following the use of tolbutamide.


Hypothalamic and cerebral cortical inhibition of melanocyte-stimulating hormone secretion in the frog, Rana pipiens.


In vivo and in vitro effects of androgens on the biosynthesis of luteinizing hormone (LH) in the anterior pituitary glands of male rats.


Thyroparathyroid uptake of selenomethionine in the rat.


Effect of thyroparathyroidectomy in hypercalcemia associated with malignancy.


Blockade of release of growth hormone by brain norepinephrine depletors.


Uptake and distribution of exogenous testosterone-1,2-3H in neural and genital tissues of the castrate guinea pig.


Effect of pregnancy and hormones on the activity of aspartate transcarbamylase and the level of nucleic acids in the mammary gland of the rat.


A specific adsorbent for vasopressin: the purification of labeled hormone.


Effects of stimulation of the vagus nerve on insulin secretion.


Effect of 17-beta-estradiol in vitro on the template capacity of uterine chromatin.


Thyrocalcitonin inhibition of bone resorption induced by parathyroid extract in thyroparathyroidectomized rats.


An effect of isoproterenol on ventilation-perfusion in asthmatic versus normal subjects.


Comparison of alveolar and arterial concentrations of 85Kr and 133Xe infused intravenously in man.


Posthyperventilation hypoxia.

Posthyperventilation hypoxia.


Hypoxia and carbon dioxide retention following breath-hold diving.


Alveolar resistance to atelectasis.

Alveolar resistance to atelectasis.


Scaling of respiratory variables in mammals.


Distribution of pulmonary blood flow as affected by transverse (+Gx) acceleration.


Effect of respiratory alkalosis on blood lactate and pyruvate in humans.


Pulmonary vascular obstruction following administration of high-energy nucleotides.


Effect of dextran on rheology of human blood: low shear viscometery.


Measurement of coronary blood flow by coincidence counting and a bolus of 84RbCl.


Partial and "complete" adrenergic blockade in posthemorrhagic shock.


Determinant of the optimal hematocrit.

Determinant of the optimal hematocrit.


Venous distensibility in patients with varicosities: in vitro studies.


Central circulatory responses to work in dry heat before and after acclimatization.


Maintenance of aortic pressure and total peripheral resistance during exercise in heat.


Sex differences in physiological reactions to thermal stress.


Reactions of men and women to repeated exposure to humid heat.


Influence of age, sex, and body weight on the energy expenditure of bicycle riding.


Regulation of ventilation during exercise at 10,200 ft in athletes born at low altitude.


Muscular exercise in young men native to 3,100 m altitude.


Cardiovascular and renal function during continuous negative pressure breathing in dogs.


Oxygen consumption and body temperatures of Eskimos during sleep.


A technique for ventricular pacing from the His bundle of the intact heart.


Cardiovascular and renal function during total body water immersion of dogs.


A simple, inexpensive, sinusoidal pressure generator.


Automatic dual-channel stimulator control unit.


Small animal anesthesia with halothane.

Small animal anesthesia with halothane.


Quantification of electrical activity in the human diaphragm.


A method for dynamic calibration of the whole-body pressure plethysmographic system.


Isolated perfused rat small bowel--technic, studies of viability, glucose absorption.


An isolated constant-current stimulator for use with man.


The effect of norethandrolone (Nilevar) on serum proteins in the female guinea-pig.


The binding of cortisol by ovine plasma proteins.


The value of rats with hereditary hypothalamic diabetes insipidus for the bioassay of vasopressin.


Endocrine influences on the net extrarenal fluxes of sodium and potassium in the European eel (Anguilla anguilla L.).


Metabolism of the dog's thyroid in vivo and in vitro.


The role of the toad urinary bladder in the amphibian "water balance effect" of neurohypophysial hormones.


Differences in the response of three- and five-week- old rats to cortisol.


Naso-alveolar cysts: aetiology, presentation and treatment. Six cases are reported.


Transzygomatic approach to the petrous apex with a record of three cases.


The place of myringotomy in the management of secretory otitis media in children.


Narrow field mastoidectomy in tympanoplasty.


On the treatment of parotid fistulae.

On the treatment of parotid fistulae.


The auditory evoked cortical response as an index of hearing in practical audiometry.


Congenital unilateral choanal atresia associated with a rhinolith.


Membranous total closure of the external auditory canal.


Further studies of the bacterial flora of the blood and tissue of dogs.


The alteration of blood-borne metastases by oriented electric fields.


Effects of electric currents and interfacial potentials on wound healing.


An ethylene oxide gas sterilizer surgical instrument case.


Rheumatoid arthritis.

Rheumatoid arthritis.


Rheumatoid arthritis--the orthopaedic contribution. I. General survey.


Improvement in psychiatric illness. Report on 400 cases treated in a psychiatric hospital.


Experimentation: rights and risks.

Experimentation: rights and risks.


Behavior of captive white-footed mice.

Behavior of captive white-footed mice. Detailed studies of the behavior of captive white-footed mice have cast a number of old problems in new perspectives. Many responses of small captive mammals cannot be interpreted at face value because of severe distortions of behavior that are caused by depriving the wild animal of natural outlets for activity. Confined animals are likely to seize upon and repeatedly exercise virtually any opportunities to modify (and alter their relationships with) their surroundings. In addition they have a strong tendency to counteract nonvolitional and "unexpected" deviations from the status quo. As a result, their responses do not bear an immutable relationship to the nature of the stimulus or other variable being modified; stimuli and activities that are rewarding in certain circumstances are avoided in others. These aspects of behavior have been illustrated by studies of nest occupancy, running in motordriven wheels, and control of intensity of illumination. The results of the control-of-illumination studies suggest the complex interplay of tendencies to modify features of the environment, to avoid conditions imposed compulsorily, and to select preferred levels of illumination. The importance of split-second timing, coordination, and quick reflex actions in the running of activity wheels is indicated by the fact that experienced white-footed mice prefer running in square "wheels" and wheels with hurdles to running in plain round wheels. The relatively conservative behavior of these mice in selecting between multiple sources of food and water and different types of activity wheels suggests the need for careful experimental design in free-choice studies with inexperienced animals. The tendency of trained animals to give some so-called "incorrect" responses even after long experience can be interpreted most reasonably in terms of the adaptive value of a certain degree of variability of behavior in the wild. White-footed mice readily master complex regimes in which several different levers and shutters must be pressed or rotated in certain sequences within seconds for different rewards. They quickly learn to traverse mazes containing hundreds of blind alleys and do so frequently without extrinsic reward. It is unlikely that these remarkable learning performances even begin to approach the capacities of the animals. When two female mice having markedly different solitary behavior patterns were placed in consort, the behavior of each changed, becoming more like that of the other, and the animals showed a strong tendency to remain in each other's company. The behavior of mice in enclosures of great extent casts doubt upon the postulate that hunger and thirst play leading roles in the motivation of wide-ranging locomotor movements. Accordingly, studies of deprived domestic animals in simple mazes may have but limited significance for understanding the behavior of wild and relatively unconfined animals. The existence of marked individual differences between mice selected at random from wild populations sounds the need for a cautious approach in the interpretation of results obtained with highly inbred domestic animals. The relatively uniform behavior of inbred strains represents only a small fragment of the total response spectrum for the species and probably has minimal significance for adaptation and evolution in the wild. When allowed to control the intensity of illumination by operating a series of switches, white-footed mice establish a roughly 24-hour regime consistent with that experienced in the wild, namely dim light during periods of activity and very dim light during periods of inactivity. Consistent with this finding, when exposed to a dim-dark light cycle, the mice are active during the dim phase, not in darkness. Artificial twilight transitions of both constant and varying color temperature have several marked effects upon the activity of white-footed mice. The existence of a strong orienting influence of dim light on the direction of wheel-running suggests that mice in the wild use the twilight sun and the moon (and possibly other celestial light sources) as navigational references.


Stereoscan electron microscopy of soil microorganisms. Details of the surface structure of microorganisms growing in soil and the complex topography of individual soil particles were observed with the Stereoscan electron microscope. Because it was not necessary to remove the microorganisms from the soil particles, it was possible to establish their occurrence in different microhabitats. This technique can provide useful ecological information about the soil microflora.


Disaccharidase: localization in hamster intestine brush borders. Electron microscopy of isolated brush borders from epithelial cells of hamster intestine demonstrates 60-angstrom knobs attached to the lumen surface of the plasma membrane. Digestion with activated papain removes these knobs. Separation and recovery of the knobs and the plasma membrane are possible. The activities of the disaccharidases invertase and maltase reside in the knobs and are not found with the plasma membrane.


Glutaraldehyde activation of nuclear acid phosphatase in cultured plant cells. Cultured tobacco cells exhibited a nuclear reaction in the cytochemical test for acid phosphatase after exposure to 2 percent glutaraldehyde. A slight preference for adenosine monophosphate over beta glycerophosphate as substrate was noted, but the enzymatic activity was not typically 5' nucleotidase. Other aldehydes tested did not elicit the same enzyme response. Nucleolar localization was distinct from that in the rest of the nucleus. Assay for spectrophotometric measurements of enzymatic activity in vitro was developed as a modification of the Burstone procedure with naphthol AS-B1 phosphate and diazo blue B.


Turgor pressure: direct manometric measurement in single cells of Nitella. A small capillary, fused at one end, serves as a micromanometer when the open end is inserted into a large Nitella cell. The cell's ability to compress the gas reveals its turgor pressure directly-save for a small correction due to capillarity. The method gives a lower limit to turgor pressure for the same cell in the normal state. The common method, incipient plasmolysis, gives an upper limit. On Nitella axillaris cells the two methods limit the turgor pressure at 5.1 to 5.7 atmospheres. The manometric method is also applicable to growing cells, where osmotic equilibrium is not present.


Chromosomal breakage induced by extracts of human allogeneic lymphocytes. A high frequency of chromosomal breakage and rearrangement has been found in fibroblasts treated with extracts of allogeneic human lymphocytes. The fact that these changes were not observed when extracts of autologous lymphocytes were tested indicates that mechanisms involving self-recognition are operative. Abnormalities, such as chromosome lagging and bridges, occurring in anaphase were also served.


Passive transport of 5,5-dimethyl-2, 4-oxazolidinedione into beef heart mitochondria. 5,5-Dimethyl-2,4-oxazolidinedione is used to estimate intracellular pH. The mechanism of transport of this compound into beef heart mitochondria was investigated to assess the validity of its use for the measurement of intramitochondrial pH. This compound and (14)C-labeled carboxy dextran were simultaneously used to determine the intra- and extramitochondrial compartments and the distribution of the compound, which was passively transported into resting, respiring, and simultaneously respiring and phosphorylating mitochondria. The transport of the compound was neither associated with electron transport nor with oxidative phosphorylation.


Enzyme defect associated with a sex-linked human neurological disorder and excessive purine synthesis. A sex-linked familial neurological disease consisting of cerebral palsy, mental retardation, choreoathetosis, and compulsive aggressive behavior is associated with a loss of an enzyme that participates in purine metabolism, namely, hypoxanthine-guanine phosphoribosyltransferase. The production of excessive uric acid in this disorder implies that the enzyme is involved in the normal regulation of purine biosynthesis. This is the first example of a relation between a specific enzyme defect and abnormal compulsive behavior. It is also the first enzyme defect in purine metabolism demonstrated in a neurological disease.


Luteinizing hormone activity in plasma during the menstrual cycle. Daily determinations of luteinizing hormone activity in plasma throughout a menstrual cycle in ten young women showed a sharp peak of activity lasting less than 48 hours around midcycle and higher mean values during the follicular phase than during the luteal phase in nine instances.


Temperature measurements from oxygen isotope ratios of fish otoliths. Measurements have shown that the temperature of a fish's habitat can be deduced from the Oxygen isotope ratio of its otoliths (ear bones). Isotope ratios Obtained from fossil otoliths indicate a water temperature which agrees wiht that found by isotope measurements on associated benthonic foraminifera.


Ant stridulations and their synchronization with abdominal movement. Two techniques for accurately correlating movements with vibrations produced by Pogonomyrmex Occidentalis show three characteristics of the stridulations: alternation of mean chirp intensity, higher frequencies during the upstroke, and interruption of chirps into distinct pulses. These pulses are produced by briefly stopping the gaster during a chirp.


Flaxedil (gallamine triethiodide): evidence for a central action. A central action of gallamine triethiodide has been demonstrated in cats with permanently implanted electrodes that permit direct repetitive stimulation and recording of afterdischarges from cerebral cortex. Systemically administered gallamine produced a consistent and reproducible augmentation of duration of afterdischarge at doses just sufficient to produce skeletal muscle paralysis. Simultaneous examination of expiratory carbon dioxide, blood pressure, body temperature, blood glucose, and direct cortical response to brief single stimuli failed to reveal any consistent peripheral change to which the centrally observed effecte Could be attributed.


Brain lesions in birds: effects on discrimination acquisition and reversal. Bobwhite quail (Colinus virginianus) with lesions of the cortex and the dorsal portion of the hyperstriatum (or " wulst") showed a considerable deficit in ability to reverse a learned discrimination between horizontal and vertical stripes. Two birds that had been run on 25 such reversals before ablation showed the same result. Lesioned birds did not, however, differ from controls in the Original acquisition of the discrimination. Analysis of performance indicated that the reversal deficit was not due to difficulties in discrimination, interference with motor ability, or lack of motivation. The deficit appeared to be based on perseveration of response to the previous positive stimulus during reversal training.


Prenatal auditory imprinting in chickens. A batch of eggs was exposed to a patterned sound continuously from day 12 to day 18 of incubation, while a control group was hatched in the quiet. In a postnatal test all chicks tended to creep toward a stationary sound source, but the experimental group showed a preference for the sound heard during incubation. In a second test the experimental chicks followed a moving model longer when it emitted the familiar sound than when it emitted a novel sound or no sound at all.


Recommendations on nomenclature of the order Mycoplasmatales.


Sexual reproduction in Histoplasma capsulatum.


Medial superior olive and sound localization.


Legg-Perthes disease in the dog.

Legg-Perthes disease in the dog.


Problems of nomenclature in cardiac arrhythmias.


Myocardial infarction in young men.

Myocardial infarction in young men.


Revascularization of the right and left coronary arterial systems. Internal mammary artery implantation, epicardiectomy and free omental graft operation.


Atrial pacing and atrioventricular conduction in anomalous atrioventricular excitation (Wolff-Parkinson-White syndrome).


Pulsus paradoxus. Effect of gravity and acceleration in its production.


Drill biopsy of the canine interventricular septum. A new cardiac catheterization technic.


Percutaneous implantation of cardiac pacemaker electrodes.


Hypertensive vascular disease. The long term effect of rapid repeated reductions of arterial pressure with diazoxide.


Fatal myocardial infarction in an 11 year old boy associated with a unique coronary artery anomaly.


The electrocardiogram today. A symposium discussion.


Single coronary artery. Antemortem diagnosis in a patient with congestive heart failure.


Congenital right coronary artery to left atrium fistula.


Effusive-constrictive radiation pericarditis. Two cases illustrating value of angiocardiography in diagnosis.


Bacterial endocarditis, pericarditis and cardiac tamponade.


Congenital absence of the left pericardium with surgical correction.


Obstructive ventricular septal defect in double outlet right ventricle.


Value of apex cardiography in the assessment of cardiac aneurysms.


Apex cardiography in the elucidation of a double or multiple impulse apex beat.


President's page. A master plan for postgraduate education.


Long-term anticoagulant treatment in coronary disease.


Fifty per cent sodium diatrizoate for selective angiocardiography in infants.


Anti-inflammatory action of a xanthinic base erivative.


Metrizoate, a new contrast medium: clinical trial in 101 cases.


Prominent auricular  T waves (Ta) as an important guide to the diagnosis of alkalosis.


Salicylate ototoxicity. A biochemical and electrophysiological study.


Experimental synotia dorsalis in mouse embryos.


Equilibrium and vertigo in a tilting environment.


Metastatic tumors of the temporal bone.

Metastatic tumors of the temporal bone.


Two tests of tone decay: their contribution to diagnostic decisions.


A histochemical survey of the activity of some dehydrogenases in the normal and infected skin of the external auditory canal of the cat.


Bilateral ivory osteoma of the nasal bones. (First case recorded).


Oncocytic cyst of the larynx.

Oncocytic cyst of the larynx.


Benign teratoma of the tonsil.

Benign teratoma of the tonsil.


The epidemiology of cancer of the bronchus: facts and suppositions.


Endoscopic management of tracheal and bronchial resection and anastomosis in bronchogenic carcinoma.


Two thousand bronchoscopies in search of cancer.


Is surgery worth-while in carcinoma of the bronchus?


New directions in the radiotherapy of lung cancer.


The development of the facial nerve in man.


Frequency of histological otosclerosis.

Frequency of histological otosclerosis.


Acetylcholinesterase activity in the efferent nerve fibers of the human inner ear.


Applicants to Canadian medical schools for 1966-67. An examination of applicants to Canadian medical schools for 1966-67 revealed that 4534 applications were received for the approximately 974 available places. The number of Canadian applications was 2866 and these were made by 1815 individual applicants, an increase of 48 over 1965-66. United States applicants declined from 1143 to 1013.Evaluations made by the schools concerning the acceptability of the Canadian applicants disclosed that 55 applicants who rated as "acceptable" by one or more schools failed to gain admission to any medical school in 1966-67 (as compared to 36 in 1965-66). However, of those applicants who did find a place 76 were evaluated as "marginal" or "unacceptable", while another 126 were rated as "acceptable" by one school but "marginal" and/or "acceptable" by one or more other schools.These results were interpreted to imply that the Canadian medical schools were still experiencing difficulty in attracting well-qualified applicants for study in medicine.


Medical education. I. Medical students in Canadian Universities: report of statistics, 1966-67. Enrolment in the 13 Canadian medical schools in 1966-67 reached a new high of 4230, an increase of 5.1% over 1965-66. The percentage of women among medical students (12.1%) was close to that of the preceding three years. There has been a levelling off in the decline of students from outside Canada in 1966-67, when 9.5% of medical students were non-Canadian. The decline had been primarily in the number of American students, which continues. The number of students from Commonwealth countries has shown a steady increase during the eight-year period under review; in 1966-67, they make up nearly one-half of all non-Canadian students. It was noted that 18.5% of overseas students came to Canada under governmental or intergovernmental sponsorship. Of the Canadian students, 94% came from the "home" provinces of the medical schools.


An attempted simulation by computer of a committee on admissions. The rising interest in formalized premedical courses preparatory to professional courses in medicine and the problem of selecting applicants to such courses have led to the formulation of a scoring technique to evaluate applicants to the first year of the premedical course offered by the Faculty of Medicine, University of Toronto. This method was applied to applicants considered for provisional admission in March 1966, and for final admission in August 1966, independently of the conventional selection carried out by the Admissions Committee. The results of the two methods are compared and discussed, and a combined selection procedure, using both the score and the Committee approach, is described.


Research in medical education: some methodological considerations. The complexities of describing human characteristics with sufficient accuracy to enable successful selection of candidates for medical school demand precise and penetrating analysis. An important tool is statistical analysis; however, current methods have not been sufficient. Methods of multivariate analysis which have been extended only recently to problems in the social sciences have great diversity and power. These methods have been outlined and their application in medical education indicated. The appropriateness of a particular method depends upon four factors: the subjects under study, nature of the data, conditions under which data were obtained, and the purpose of the analysis. A critical consideration of these factors should enable the choice of a method capable of providing meaningful conclusions concerning medical school selection to be made.


Experiences with evaluation procedures in pathology teaching at Dalhousic University. The experience of evaluation of both students and course in pathology at Dalhousie Medical School indicates that valuable reproducible and probably objective information is obtained by the use of frequent multiple-choice tests combined with substantial final oral examinations. Course evaluation by student questionnaires has provided useful information on course modifications and teaching techniques. The most informative feature of the evaluation program is in the provision of mechanisms for feedback from students to faculty and among faculty members. By these means weaknesses in teaching have been identified and often corrected. The method has aided in the early identification of poor students and of their areas of weakness so that remedial instruction can be instituted before the final examination.


Depth in training in academic pathology including teaching and research. Excellent training in academic pathology, including research, results when teaching becomes the prime function of the scholars in an academic department. Teaching of postgraduates requires research and practice and furthermore requires excellence in these fields. A program designed to teach the postgraduates orientates the research and practice to this end rather than making these ends in themselves. A major aim of pathology is to explain at the cell level the mechanism of interaction between intrinsic and extrinsic factors resulting in the abnormality of cell function in disease. The traditional core training in tissue diagnosis develops the interest and ability to analyze the cell and its intracellular activities. To realize the relation of structure and function as the ultimate aim of pathology an intensive study of some of the collateral fields of cell chemistry, physiology, immunology and genetics must become a major part of the organized program.


Thoughts on learning and teaching in the first two years of the medical curriculum. Suggestions for improvement of the educational program in the first two years of the medical curriculum are made in the light of simultaneous experiences as teacher and student. The learning needs of the student should be given more consideration. Many of the present learning-teaching problems could be solved by closer communication and collaboration between instructors teaching the same students coupled to an official recognition of the value of good teaching. In spite of a multiplicity of courses and basic science departments, the student is a single person with a rather limited goal. He is required to learn and remember a vast amount of detailed factual information during his first two years of the medical curriculum. The medical student should be reinstated as an integral human component of the structure and functioning of each department. This is a difficult task because the dual functions of research in a specialized discipline and undergraduate medical teaching frequently pull an individual's or department's activities in opposite directions and lead to administrative problems.


Medical education today.

Medical education today.


Canadian schools of medicine.

Canadian schools of medicine.


Inhibition of DNA synthesis in HeLa cells by hydroxyurea.


Studies on latent derivatives of aminoethanethiols as potentially selective cytoprotectants. I. A spectrophotometric assay for aminoethanethiols in biologic media.


Studies on latent derivatives of aminoethanethiols as potentially selective cytoprotectants. 3. Reactions of cysteamine-S-sulfate in biologic media.


Effects of antitumor agents on the synthesis of nucleolar DNA.


Free amino acids and related compounds in the blood and urine of patients with malignant melanoma.


The reduction of the tumorigenicity of cigarette smoke condensate by addition of sodium nitrate to tobacco.


Preliminary report on virus-like particles in canine leukemia and derived cell cultures.


Effect of human cancerous serum on the chick embryo.


Acellular passage of 32-P-induced leukemia: an electron microscopic study.


Subcutaneous sarcomas in Wistar rats following single 3-methylcholanthrene ingestion at age 8-15 days.


The fatty acid composition of the phosphatides of normal and malignant epidermis.


Reaction mechanism of some aromatic nitrogen mustards.


Turnover of 45 S RNA of regenerating liver and Walker tumor.


Hydroxyurea. I. Acute cell death in proliferating tissues in rats.


The isolation, characterization, and antigenicity of malignolipin-like material from normal and tumor tissue.


Neutralization of sublines of a mouse leukemia virus with murine antibody, as measured by the spleen focus assay.


Survival time and mode of death in treated and untreated mice with Bergen A4 ascites carcinoma.


Inhibition of in vitro lymphocyte transformation during chemotherapy in man.


Some effects of a high sodium intake in burned patients.


The effect of a high intake of calcium on magnesium metabolism in normal subjects and patients with chronic renal failure.


The effect of breathing 30 per cent oxygen on pulmonary ventilation-perfusion inequality in normal subjects and patients with chronic lung disease.


Structural and functional changes following small intestinal resection in the rat.


Respiratory gas exchange in chronic anaemia.


The intestinal response to high bulk feeding in the rat.


Plasma renin concentration in conscious rabbits during pressor infusions of renin.


The effect of dietary calcium on the absorption and retention of radiostrontium.


Reinforcement uptake. 1. A dimension of behavior.


Radiopaque markers as components of orally ingestible toxic drugs.


Niemann-Pick's disease manifesting as schizophrenia.


Patterns of gastric acid secretion in patients with duodenal ulcer: correlations with clinical and personality features.


Acid secretion from canine separated fundic pouches.


Stimulation of gastric motility by acid.


Validation of dilution indicators in the stomach.


Gastric blood flow and acid secretion during direct intraarterial histamine administration.


Presence of a gastric motor-stimulating property in duodenal extracts.


Congenital familial nonhemolytic hyperbilirubinemia in an adult with central nervous system derangement.


Hepatic lesions in chronic inflammatory bowel disease. I. Clinical correlations with liver biopsy diagnoses in 103 patients.


Dysphagia in children with epidermolysis bullosa.


Radiological demonstration of a patent ductus venosus in an adult.


Clonorchiasis. Treatment with chloroquine phosphate.


Stress and the gut.

Stress and the gut.


Maximal acid secretion in man.

Maximal acid secretion in man.


The drug reaction problem.

The drug reaction problem.


The effect of 7S and 19S antibodies on the primary response to Salmonella typhi antigens.


On the significance of the phacoautoantibodies demonstrated in the sera of patients with senile cataract.


The uptake of tritiated thymidine by human spleen cell cultures: a comparison between fresh and stored cells.


Antibacterial sensitivity of Bifidobacterium (Lactobacillus bifidus). The antibacterial sensitivity patterns of gram-positive, nonsporeforming, anaerobic bacilli variously classed as Lactobacillus bifidus, Actinomyces bifidus, or Bifidobacterium were studied by the plate dilution method. A total of 34 strains, mostly from human feces, was studied. Three species, B. longum, B. adolescentis, and B. bifidum, were represented with 11, 11, and 6 strains, respectively. The other six strains fell into four other species. Most strains of all types resisted 100 mug/ml or more of neomycin, polymyxin B, and nalidixic acid. They were somewhat less resistant to kanamycin and still less so to streptomycin. All strains were inhibited by less than 1 mug/ml of penicillin G and erythromycin, by 3.1 units or less per ml of bacitracin, by 3.1 mug/ml or less of chloramphenicol, and by 6.2 mug/ml or less of tetracycline and lincomycin. Most strains were inhibited by 3.1 mug/ml of vancomycin. Results were very variable with cephalothin and nitrofurantoin, with some strains quite resistant. With half of the drugs tested, there were moderate differences in sensitivity between different species. These data are discussed in relation to the effect of antimicrobial agents on bifid bacilli in the normal human fecal flora, in relation to the implications thereof, and in relation to the usefulness of several agents (particularly neomycin, nalidixic acid, and polymyxin B) in selective media for Bifidobacterium.


Purification and characterization of yeast beta-glucosidases. Constitutive beta-glucosidases from Saccharomyces fragilis (Y-18) and S. dobzhanskii (Y-19) precipitated at the same concentration of ammonium sulfate. The partially purified enzymes had similar activation energies, molecular weights, affinities for certain natural and synthetic beta-glucosides, and optimal pH values for substrate hydrolysis, and they were stable over approximately the same pH range. The enzymes, however, could be clearly distinguished by other criteria. Affinities of the synthetic, sulfur-containing beta-glucosides for Y-18 enzyme were many times greater than for Y-19 enzyme. The latter enzyme was more resistant to heat. The two enzymes eluted from diethylaminoethyl cellulose at different concentrations of sodium chloride. In precipitin tests, homologous enzyme-antisera systems were highly specific. The beta-glucosidase synthesized by a hybrid, S. fragilis x S. dobzhanskii (Y-42), was unique. Characterization of this enzyme produced values which were intermediate to those for the enzymes from the parental yeast strains. Heat-inactivation slopes and Lineweaver-Burk plots for the Y-42 enzyme were anomalous. It is suggested that hydrolytic activity in Y-42 preparations is due to a spectrum of hybrid enzyme molecules composed of varying amounts of two distinct polypeptides. It is further suggested that these polypeptides may be identical to those synthesized by the parental Y-18 and Y-19 yeast strains.


Evidence for multiple molecular forms of yeast beta-glucosidase in a hybrid yeast. A mixture of beta-glucosidases from Saccharomyces fragilis (Y-18) and S. dobzhanskii (Y-19) eluted from diethylaminoethyl cellulose in two peaks, whereas the enzyme from a hybrid, S. fragilis x S. dobzhanskii (Y-42), eluted in a single broad peak. The highest Y-42 activity fractions eluted at a sodium chloride molarity which was intermediate to the molarities at which most of the Y-18 and Y-19 activity was eluted. In cellulose polyacetate strips, Y-42 enzyme migrated as a diffuse band which spanned the distances migrated by the enzymes from the parent yeast strains. Antisera against either Y-18 or Y-19 enzyme precipitated 80 to 90% of Y-42 enzyme activity. When Y-42 enzyme was dissociated by heat or urea and reacted with parental antiserum, a concomitant increase in the opposite parental activity was demonstrable in both precipitation and complement-fixation (CF) tests. Urea-dissociated beta-glucosidases were resolvable by sucrose-gradient centrifugation into multiple bands displaying specific CF activity. When the enzymes were exposed to 4 m urea for 12 min, particles of approximately 110,000 molecular weight were obtained. By extending the exposure time to 40 min, and incorporating 0.5 m urea in the gradients, smaller particles were detected with molecular weights ranging from 18,000 to 23,000. Attempts to regenerate enzyme activity after dissociation with urea were only moderately successful. Results suggested that a slightly acidic environment favored reassociation, as did the presence of 2-mercaptoethanol. Residual urea also seemed important. It is proposed that the structural genes for both Y-18 and Y-19 enzyme are present in Y-42 cells with either independent or closely interacting regulatory mechanisms. Since synthesis of the two parental-type polypeptides may be unequal, the availability of enzyme subunits for subsequent polymerization in the cell cytoplasm might be equalized at the polysome level. Random association of subunits would produce a binomial distribution of true hybrid enzyme molecules.


Cell permeability: a factor in the biotin-oleate relationship in Lactobacillus arabinosus. II. Effect of oleic acid and other surfactants on free biotin uptake. Bound biotin-saturated cells were incubated in the presence of biotin and glucose (37 C, pH 7.5) with or without oleic acid, Tween 20, 40, 60, and 80, Aerosol OT, sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide, Triton X-100, Non-Ion-Ox, and Haemo-Sol. With low concentrations (up to 5 mug/ml) and short reaction times (up to 10 min), oleic acid stimulated free biotin accumulation. Increased concentrations (10 to 50 mug/ml) or reaction times (10 to 30 min) caused progressive reductions in uptake or increased release of previously accumulated vitamin. Combination of Tween 40 (1 mg/ml) with oleic acid (up to 50 mug/ml) detoxified oleic acid and stimulated free biotin uptake. Oleic acid (5 mug/ml or more) reduced cell viability, an effect which was overcome by Tween 40. All other surfactants tested stimulated free biotin accumulation at sublethal concentrations. Aerosol OT and SDS exhibited the same degree of stimulatory activity as detoxified oleic acid; however, at concentrations higher than 200 mum, a rapid decrease in vitamin accumulation was observed which paralleled that caused by increased oleic acid concentrations. The results suggest that oleic acid and other surfactants affect the permeability of cells of Lactobacillus plantarum (formerly called L. arabinosus) in a similar manner.


Thiobarbiturate-reacting materials in microorganisms. The amount of thiobarbiturate-reacting material in 51 strains of bacteria and three yeasts was determined. Reactive material was found to be present in all of the gram-negative bacteria examined. It was assumed that the reactive material in this case was primarily 2-keto-3-deoxyoctonate (KDO), an eight-carbon sugar acid which is usually associated with the cell wall lipolysaccharide of members of the Salmonella-Escherichia group. Very little reactive material could be detected in the gram-positive species and yeasts that were examined. When expressed as per cent dry weight, the gram-negative bacteria exhibited about eight times more reactive material than the gram-positive species. It is suggested that the small amount of reactive material detected in gram-positive cells and yeasts is due to compounds other than KDO.


Induction by L-tryptophan and an analogue, alpha-methyl-DL-tryptophan, of the enzymes catabolizing L-tryptophan in Pseudomonas. An investigation was made of the pattern of induction of the enzymes that metabolize l-tryptophan through kynurenic acid (the quinoline pathway) in Pseudomonas fluorescens. The first four enzymes in the pathway were not induced in the same proportions or in the same time courses. This lack of coordinate induction excludes a mechanism of regulation of these enzymes at a single site as proposed in the operon model. The enzymes were induced in a sequential pattern in the order of their position on the pathway, when they became the limiting reactions. The nonmetabolizable analogue, alpha-methyl-dl-tryptophan, caused a measurable elevation in the levels of the first three enzymes of the same pathway. Evidence is presented that growth of the cells in the presence of alpha-methyl-dl-tryptophan caused the accumulation of endogenous tryptophan, and that induction by the nonmetabolizable analogue is induction by the endogenous tryptophan.


Transaminase activity and other enzymatic reactions involving pyruvate and glutamate in Chlamydia (psittacosis-trachoma group). The agents of meningopneumonitis (MN) and of trachoma (TR) purified from chick embryo allantoic fluids and yolk sacs, respectively, were shown to produce CO(2) from the C(1) positions of pyruvate and glutamate, but not from the other carbon atoms. The reaction with pyruvate did not require did not require the addition of cofactors, but was stimulated to a small extent by alpha-lipoic acid and, in the case of TR, also by diphosphothiamine, and nicotinamide adenine dinucleotide (NAD). The reaction of MN with glutamate was greatly stimulated by the addition of NAD and pyruvate, and resulted in the accumulation of alanine. The reaction of TR with glutamate was also greatly enhanced by added NAD, but was not affected by added pyruvate. When eight intermediates of the citric acid cycle were added to MN cells incubated with glutamate-C(14), plus NAD and pyruvate, they reduced to varying degrees the evolution of C(14)O(2). It was shown by chromatography that the C(14) label extended to alpha-ketoglutarate and succinate, but not to fumarate and malate. A net gain in adenosine triphosphate could not be demonstrated in MN cells incubated with combined glutamate, pyruvate, oxaloacetate, and various cofactors. These results furnish additional examples of real or apparent gaps in enzyme sequences in Chlamydia.


Nature of penicillin-induced growth inhibition of Mycoplasma neurolyticum. When penicillin was added to cultures of Mycoplasma neurolyticum in amounts up to 1,000 units per ml, lag time and generation time were increased and the total population was reduced in proportion to the antibiotic concentration. Although growth suppression by penicillin was complete, the death rate was slow and linear over periods up to 12 days. Growth after induced lag was due to a decay in penicillin activity and was not the result of mutant selection. However, repeated transfer in media which contained increasing concentrations of penicillin resulted in normal growth of M. neurolyticum at penicillin levels as high as 1,000 units per ml. Penicillinase did not play a role in recovery from penicillin-induced lag, and the inactive penicillin molecule did not prevent normal growth of M. neurolyticum. Removal of penicillin from the medium by washing or penicillinase during the induced lag was immediately followed by normal growth of the organism. These results suggest a reversible antibiotic function for penicillin which prevents multiplication of the organism by means unrelated to cell wall formation.


Heat-labile enzymes in a psychrophilic bacterium. The oxidative and fermentative activities of a psychrophilic bacterium (strain 82), whose maximal growth temperature is 35 C, were completely destroyed by exposure of the cells to 46 C for about 1 hr, whereas those of mesophilic Escherichia coli were unaffected. Similar results were obtained with cell-free extracts. In attempts to determine some of the specific enzymes inactivated in strain 82 by exposure to 46 C, it was found that reduced nicotinamide adenine dinucleotide oxidase was completely inactivated at 46 C in 2 hr. Also, cytochrome c reductase was completely destroyed at 46 C in 1 hr and was 70% destroyed at 40 C in 2 hr. The heat lability of the latter may determine the maximal growth temperature of the organism. In addition, the results indicated that the enzymes of strain 82 involved in the clastic split of pyruvate to formate and acetate are inactivated by exposure to 46 C and that the lactic and glycerol dehydrogenases are more heat-labile than those in E. coli. Succinic, nicotinamide adenine dinucleotide phosphate-alcohol, and glucose-6-phosphate dehydrogenases, however, in both strain 82 and E. coli, were essentially unaffected by exposure to 46 C for 2 hr.


Complex lipids of Rhodomicrobium vannielii. Eight components, seven of which contained phosphorus, were found in the phospholipid fraction of Rhodomicrobium vannielii. The major components were lipoamino acid (o-ornithine ester of phosphatidyl glycerol, 46.5%) and phosphatidyl choline (26.5%). The other six components were phosphatidyl glycerol (9.7%), bisphosphatidic acid (6.7%), phosphatidyl ethanolamine (4.5%), phosphatidic acid (1.8%), lysophosphatidyl glycerol-o-ornithine ester (3.2%), and N,N-ornithine amide of unidentified fatty acid (0.95%). Total phospholipid accounted for 4.2% of cell dry weight. The major fatty acid was vaccenic acid, C(18:1), which accounted for approximately 90% of the total fatty acids of the complex lipid fraction. The other four fatty acids were C(16:0) (6.25%), C(18:0) (3.8%), C(14:0) (0.7%), and C(16:1) (0.35%). The sulfolipid content was 0.01% of the cell dry weight or 0.14 mumoles per g of dried cells, assuming that its fatty acid component is vaccenic acid. No steroids were detected.


Fatty acids of extractable and bound lipids of Rhodomicrobium vannielii. Cells of Rhodomicrobium vannielii grown at 29 C in a lactate-containing medium were extracted at room temperature with organic solvents. The extractable fraction contained the bulk of the simple lipid (1.87% of cell dry weight) and complex lipids (phospholipids, 4.2%; sulfolipid, 0.01%), coenzyme Q (0.09%), and pigments (carotenoids 1.2%; bacteriochlorophyll, 1.9%). The cell residue contained the bound lipids (nonpolar fatty acid fraction, 1.86%; polar hydroxy fatty acids, 0.49%). The residue also contained poly-beta-hydroxybutyric acid (0.2%), which was extracted in boiling chloroform. In both the simple and complex lipids, vaccenic acid (11-octadecenoic acid) was the largest single component (approximately 90% in each fraction). The fatty acids of the bound lipid contained 35% vaccenic acid, even- and odd-numbered saturated and unsaturated straight-chain fatty acids, cyclopropane-, branched-, and alpha- and beta-hydroxy fatty acids. The extractable lipids contained only straight-chain saturated and unsaturated even-numbered fatty acids. Nearly 60% of hydroxy fatty acid fraction was alpha-hydroxydodecanoic acid (24%) and beta-hydroxydodecanoic acid (34.5%). Coenzyme Q was crystallized and identified as Q(9) on the basis of melting point and chromatographic properties. Q(10) had been previously reported.


Cell wall constituents of Leuconostoc citrovorum and Leuconostoc mesenteroides. The cell wall constituents of Leuconostoc citrovorum 8082, L. mesenteroides 10830a, and L. mesenteroides 11449 have been ascertained. All three strains contained glycerol. Glucose and rhamnose were the major reducing sugar constituents. Alanine, glutamic acid, lysine, glucosamine, and muramic acid were the principal amino acids and amino sugars in all three strains. In addition, strain 10830a contained l-serine as a major cell wall component. Quantitative amino acid analyses indicate that glutamic acid, lysine, glucosamine, muramic acid, and serine may be present in the cell walls in equimolar amounts and that alanine is present in three to four times these quantities. The similarities and differences between the cell wall constituents of the leuconostocs and those of the lactobacilli and streptococci are discussed.


Magnesium starvation of Aerobacter aerogenes. I. Changes in nucleic acid composition. Aerobacter aerogenes incubated in a medium containing all factors necessary for exponential growth except Mg(++) continued to synthesize nucleic acids and proteins for more than 70 hr, provided the major carbon source was in excess at all times. After 24 hr of Mg(++) starvation, deoxyribonucleic acid content in the culture had increased 10-fold. In contrast, the viable-cell count increased only about threefold during the first few hours and then remained approximately constant for the subsequent 70 hr. After specified intervals of Mg(++) starvation, extracts of the bacteria, or ribonucleic acid (RNA) purified from them, was centrifuged through gradients of sucrose to separate transfer RNA from ribosomal components. After correcting for losses, we obtained the following results. (i) There was a progressive rise in the content of transfer RNA competent to accept amino acids and during starvation it remained completely stable. (ii) In contrast, the contents of normally sedimenting ribosomal RNA and ribosomal subunits (30 and 50S) remained approximately constant for more than 24 hr. This did not result from stability of ribosomes made prior to starvation together with an inhibition of synthesis of new particles. Rather, ribosomes were continually breaking down and being replaced by an equivalent number of new ones. (iii) The breakdown of ribosomes appeared to be sequentially ordered; polysomes yielded 70S monomers, which then gave 30 and 50S particles, and these disintegrated to smaller units and finally to acid-soluble products. (iv) Furthermore, the particles derived from breakdown do not appear to exchange with subparticles on the path of assembly. Thus, ribosome decay was age-dependent and ribosomal RNA molecules had a minimal life expectancy of 90 min; however, some survived much longer.


Antibodies in histoplasmosis.

Antibodies in histoplasmosis. Production of precipitating and complement-fixing antibody in rabbits and other animals was induced by immunization with live yeast-phase cells of Histoplasma capsulatum. Results of studies of polysaccharide antigens from three strains of H. capsulatum, by quantitative complement-fixation with human and rabbit antisera, strongly suggest the presence of type specificity. The variations of titer during 11 weeks in one patient with histoplasmosis and the variations of titer among a group of patients with histoplasmosis were studied by use of quantitative complement-fixation tests.


Magnesium starvation of Aerobacter aerogenes. 3. Protein metabolism. The metabolism of the ribosomal and soluble protein components of Aerobacter aerogenes was examined during its incubation in a Mg(++)-deficient medium. Bacteria were exposed to leucine-H(3) during the exponential growth period preceding Mg(++) starvation, and extracts were prepared after intervals of starvation and were centrifuged through gradients of sucrose to separate ribosomal from soluble proteins. Ribosomal proteins synthesized during the preceding exponential growth were slowly lost from the ribosomes; after 8 hr of starvation, few, if any, sedimented with ribosomes. Losses of total protein, together with the known rate of ribosome decay during Mg(++) starvation, suggested that these ribosomal proteins are ultimately degraded to acid-soluble products and account for all protein lost by the starving cells. These conclusions were supported by studies of Mg(++) starvation in a uracil-requiring strain of A. aerogenes: during uracil starvation a smaller fraction of the proteins synthesized were ribosomal, and the fraction of protein which subsequently decayed during Mg(++) starvation was correspondingly less. During recovery from Mg(++) starvation, proteins, lost from disintegrated ribosomes, were not detectably reutilized into new particles even before their degradation to acid-soluble products was complete. Synthesis of soluble proteins continued for more than 24 hr of starvation at a rate per milliliter close to 45% of the instantaneous rate per milliliter of the exponentially growing bacteria at the time Mg(++) was removed. This value agreed with that found previously for synthetic rates of deoxyribonucleic acid, transfer ribonucleic acid, and ribosomal ribonucleic acid during starvation relative to rates during exponential growth.


Effect of temperature on the intracellular growth of Histoplasma capsulatum. The rate and form of growth of Histoplasma capsulatum within histiocytes derived from homothermic and poikilothermic animals, and incubated at 25, 30, and 37 C, are described. The generation time of the fungus in mouse cells incubated at 37 and 25 C was 11 and 24 hr, respectively. Blastospore formation was progressively retarded in cells at 25 C, and this retardation was accompanied by germination of some of the blastospores. The generation time of the fungus in mouse cells incubated at 30 C was the same as it was at 37 C. Germ tube formation was not a prominent feature of intracellular growth at 30 C. The rate of growth of H. capsulatum within frog histiocytes at 30 and 25 C was slower than it was in mouse cells at the same temperatures. Some loss of frog histiocytes in cultures incubated at 37 C prevented accurate estimation of the rate of growth of the fungus at this temperature. Growth of H. capsulatum in frog histiocytes kept at 25 C was progressively retarded, and the retardation was accompanied by germination of the yeasts. Yeast-phase growth predominated in fish histiocytes incubated at 30 C, whereas germ tubes were formed within such cells incubated at 25 C. Cell survival of fish histiocytes was relatively poor in culture, and no estimates of rate of growth of the fungus within these cells were made.


Autoradiographic evidence for the impermeability of mouse peritoneal macrophages to tritiated streptomycin. Cultured mouse peritoneal macrophages were found to be relatively impermeable to streptomycin. Based on radioactivity measurements and radioautographic evidence, macrophages were impermeable to tritiated dihydrostreptomycin for periods up to 20 hr of incubation. Little or no intracellular streptomycin could be detected even when incubation was carried out in the presence of therapeutic blood levels of carrier dihydrostreptomycin. When the cultured mouse macrophages were allowed to phagocytize staphylococci, yeast cells, or polystyrene latex particles in the presence of tritiated streptomycin, the impermeability of the cells to the antibiotic was not affected. These observations suggested that the process of phagocytosis does not facilitate the intracellular accumulation of streptomycin, as seems to be the case for the fixed phagocytic cells of the liver.


Group A streptococcal L forms. I. Persistence among inoculated mice. L forms induced from two strains of group A Streptococcus were inoculated intraperitoneally and intravenously into conventional and germ-free mice. After intravenous injection, streptococcal L forms disappeared very quickly from the blood, whereas, after intraperitoneal injection, it was possible to isolate them as long as 25 days after inoculation. Observations suggest that a certain degree of reversion to a bacterial form may occur spontaneously in animals.


Function of growth factors for rumen microorganisms. I. Nutritional characteristics of Selenomonas ruminantium. Nutritional characteristics of Selenomonas ruminantium var. lactilytica isolated from a sheep rumen were studied. The organism required for growth the addition of a clarified rumen fluid to a Trypticase-yeast extract medium with either lactate or glucose as an energy source. The requirement for rumen fluid was found to be satisfied by volatile fatty acids in glucose media and by biotin in lactate media. Straight-chain saturated fatty acids with C(3) to C(10) carbon skeleton had been found to be effective. Among them, n-valerate was most effective at the lowest concentration. An abnormal morphology was observed with n-valerate-deficient glucose media. n-Valerate was essential in glucose media, and it was stimulatory in lactate media. Fermentation products from glucose were lactate, propionate, and acetate, and fermentation products from lactate were propionate and acetate. When cells were grown in a glucose medium containing n-valerate-C(14), the label was present in cell fractions. Almost all of the activity was found in lipid materials.


Use of refined agar for the in vitro propagation of the spherule phase of Coccidioides immitis.


Ultrastructure of the membrane system in Lactobacillus plantarum. Electron microscopic study of Lactobacillus plantarum revealed mesosomes in different stages of maturation and structural relation with other cell organelles. Small, immature mesosomes were bounded by a prominent electron-dense layer with another extremely faint layer on the outside. This corresponds to the appearance of the cytoplasmic membrane. Large mature mesosomes were surrounded by a triple-layered unit membrane having electron-opaque layers of approximately equal density, suggesting that the composition of the boundary membrane alters during development of this structure. Three-dimensional observations derived from serial sections indicated that mesosomes always maintain a connection between the cytoplasmic membrane and the comparable layers of their boundary. The cytoplasmic membrane also consisted of a triple-layered unit membrane, the innermost layer of which was less electron-opaque and was usually hidden by the relatively dense background of the cytoplasm. The innermost layer of the cytoplasmic membrane was most clearly seen in plasmolyzed cells. Only mature mesosomes made distinct contacts with, or were partially immersed in, the nucleoplasm. The boundary of such mesosomes frequently seemed to be discontinuous, suggesting that the mesosome interior was in direct contact with the nucleoplasm. Mesosomes involved in cross-wall formation at a division plane increased in size and passed through a sequence of positions which led ultimately to an association with the nucleoplasms of the daughter cells. The inner surface of the cell wall was lined by a thin, electron-dense layer whose composition and function are unknown. Under the cultural conditions used, this organism regularly contained a polyphosphate granule.


Carotenoid pigments and photokilling by acridine orange.


Pathway of propionate formation in Bacteroides ruminicola.


Estimates of the overall rate of growth of the intestinal microflora of hamsters, guinea pigs, and mice.


Factors enhancing the host-cell penetration of Toxoplasma gondii. The penetration into HeLa cells of Toxoplasma gondii was studied with a cell culture technique. The influence on the rate of penetration and the number of penetrating Toxoplasma parasites was tested by use of preparations of disintegrated parasites mixed with test parasites. These preparations were found to contain factors enhancing the penetrating rate of the parasites. This effect was demonstrable by use of untreated parasites as well as parasites lacking active motility owing to a previous exposure to Formalin. The preparations of disintegrated parasites contained, in addition, components inhibitory to the penetration-enhancing factors. These inhibitory components were able to reduce the penetrating capacity of normal Toxoplasma parasites, suggesting that the studied enhancing factors may play a role in the natural process of penetration. The efficacy of various techniques for disintegration of Toxoplasma parasites was investigated for release of penetration-enhancing factors from Toxoplasma parasites. The methods used resemble those used for liberation of lysosomal enzymes. Reduced osmotic pressure was obviously not adequate for release of enhancing factors, whereas the freezing and thawing procedure, sonic treatment, and irradiation produced high yields. It was difficult to evaluate the effect of incubation at acid pH on release of enhancing activity, because the penetration-promoting factors seemed unstable on both the acid and the alkaline sides of pH 7.6.


Hog intrinsic factor. I. Isolation of vitamin B12-binding fractions from hog pylorus.


Antimicrobial activity of aflatoxins.

Antimicrobial activity of aflatoxins. Antimicrobial activity of a crude aflatoxin preparation and of aflatoxin B(1) was studied. They were found inactive against common gram-positive and gram-negative bacteria at a concentration of 100 mug/ml. Both samples of aflatoxin did, however, exhibit antimicrobial activity, though narrow and limited, against various strains of Streptomyces and Nocardia. The antibiotic action of aflatoxin B(1) was confirmed by bioautogram after thin-layer chromatography. Among seven strains of microorganisms, including aflatoxin-sensitive and -resistant strains, N. asteroides IFM 8 was found to reduce aflatoxin B(1), in addition to other minor fluorescent components in the crude preparation.


Hog intrinsic factor. II. Some physicochemical properties of vitamin B12-binding fractions from hog pylorus.


Characterization of a nuclease produced by Staphylococcus aureus.


The metabolism of ceramide trihexosides. I. Purification and properties of an enzyme that cleaves the terminal galactose molecule of galactosylgalactosylglucosylceramide.


Titration studies on adenosine triphosphate-creatine phosphotransferase.


Studies on the chemical modification of arginine. I. The reaction of 1,2-cyclohexanedione with arginine and arginyl residues of proteins.


The binding of saccharide to crystalline and soluble lysozyme measured directly and through solubility studies.


Acyl dihydroxyacetone phosphate. A rapidly labeled lipid in guinea pig liver mitochondria.


Direct calorimetric studies on the heats of ionization of oxygenated and deoxygenated hemoglobin.


The effect of temperature on the oxygen-linked ionizations of hemoglobin.


Alterations in the nature of ribonucleic acid synthesized in rat liver during regeneration and after cortisol administration.


Biosynthesis of streptomycin. IV. Further studies on the biosynthesis of streptidine and N-methyl-L-glucosamine.


Alginic acid degradation by eliminases from abalone hepatopancreas.


Energy-linked changes of hydrogen ion concentration in submitochondrial particles.


Studies on the control of fatty acid synthesis. I. Stimulation by (+)-palmitylcarnitine of fatty acid synthesis in liver preparations from fed and fasted rats.


Liver glucokinase induction in acute and chronic insulin insufficiency in rats.


The histidyl residues of insulin. I. Reactivity toward iodine.


Mammalian alpha-keto acid dehydrogenase complexes. II. An improved procedure for the preparation of 2-oxoglutarate dehydrogenase complex from pig heart muscle.


Investigations of the chymotrypsin-catalyzed hydrolysis of specific substrates. I. The pH dependence of the catalytic hydrolysis of N-acetyl-L-tryptophanamide by three forms of the enzyme at alkaline pH.


Reactions of renal dipeptidase and cupric ions with unsaturated dipeptides.


Ion transport in liver mitochondria. I. Metabolism-independent Ca++ binding and H+ release.


The oxidation of 1-deuterated glucose by glucose oxidase.


The effect of cholesterol feeding and fasting upon beta-hydroxy-beta-methylglutaryl coenzyme A reductase.


Clinical effects of recurrent attacks of acute rheumatic fever: a prospective epidemiologic study of 105 episodes.


An analysis of blood pressure trends based on annual observations of the same subjects.


Editorial: peptic ulcer diet.

Editorial: peptic ulcer diet.


Educating stroke patient families.

Educating stroke patient families.


Patients' misconceptions about their peptic ulcer diets: potential obstacles to cooperation.


Complications following hip fractures.

Complications following hip fractures.


On the isolation and characterization of substances in the urine of patients with collagen disease.


The normal range--a common misuse.

The normal range--a common misuse.


Previous pulmonary disease and lung cancer: a case-control study.


Myocardial infarction in Hawaiian and Japanese males on Oahu--a review of 505 cases occurring between 1955 and 1964.


The penetration of 5-hydroxytryptamine through the blood-brain barrier.