Inducible Lysis in Clostridium tetani

Lysis was induced in seven strains of Clostridium tetani by exposure to mitomycin C. The search for a suitable indicator strain to detect bacteriophage in lysates has, so far, been unsuccessful. Inhibition studies on macromolecular synthesis during induction have shown that deoxyribonucleic acid, ribonucleic acid, and protein syntheses are all involved in the lysis induced by mitomycin C. In experiments comparing toxin and protein content in induced and uninduced cells of C. tetani, the toxin-protein ratio proved to be the same in both systems up to the point of lysis. Several possible hypotheses deduced from these results are discussed.     

Comparative cytological study of Phasianus colchicus,Meleagris gallopavo,and Gallus domesticus

Summary Since viable intergeneric hybrids between the chicken (Gallus domesticus) and the pheasant (Phasianus colchicus) have been reported, as well as interfamilial hybrids between the chicken and the turkey (Meleagris gallopavo), the chromosome complements of the pheasant and the turkey were compared with that of the chicken. In these three species belonging to the order Galli, the Z-chromosomes appeared to be identical, while the autosomal complements of the pheasant and the turkey differed radically from that of the chicken. It was noted with some surprise that the pheasant of the family Phasianidae and the turkey of the family Meleagridae have very similar chromosome complements, at least so far as gross morphology of somatic metaphase chromosomes is concerned.This work was supported in part by grant C-5138 from the National Cancer Institute, U.S. Public Health Service, and grant C-17601 from the National Science Foundation.The authors gratefully acknowledge the generosity of Rea's Game Birds, Paramount, California, who supplied the pheasant chicks, and the McPherin Hatcheries, Sunnymead, California, who furnished the turkey chicks. The authors also appreciate the editorial assistance of'Patricia A. Ray.     

Clear Media for the Recovery of Pasteurella tularensis

Peptic digests of blood and hemoglobin were investigated as substitutes for the blood used in the preparation of glucose-cysteine-blood agar plating medium for the recovery of the virulent Schu strain of Pasteurella tularensis. Digest media so prepared were found to be satisfactory for the quantitative recovery of freshly grown cells but not for cells stored longer than several days. The addition of appropriate quantities of human plasma, bovine sera, or soluble starch rendered the digest media appropriate for use with stored cultures. The peptic digest-plasma (PDP) and peptic digest-starch (PDS) media were evaluated and found satisfactory for the quantitative recovery of P. tularensis Schu from freshly prepared and stored cultures, and from aerosols produced therefrom. With cultures stored longer than 6 weeks, the starch modification (PDS) was not as satisfactory as, and the plasma variation (PDP) was better than, glucose-cysteine-blood agar (GCBA) for the recovery of the organisms. PDP was superior to either GCBA or PDS medium for the recovery of the weakly virulent Jap 4 and Niieg-blue strains of P. tularensis.     

THE DEGENERATIVE CHANGES IN PANCREATIC ACINAR CELLS CAUSED BY DL-ETHIONINE

Degeneration of pancreatic acinar cells in rats injected with ethionine was studied by electron microscopy. The most conspicuous morphologic lesions occurred in the ergastoplasm. There was a widening of the endoplasmic reticulum, a decrease in number of membrane-associated ribosomes, and a development of fine and coarse vacuoles containing agranular disoriented membranes. Cytoplasmic ribosomes unassociated with membranes were less numerous. Nuclear changes consisted of a coarsening and clumping of the nuclear chromatin, chromatin margination, and increased osmiophilia and vacuolation of the nucleolus. Eight to ten days after the beginning of ethionine injections, changes in zymogen granules, mitochondria, and the Golgi apparatus appeared, but only after extensive damage to the acinar cell. The effects were consistent with ethionine's known interference with protein metabolism but also suggest disturbance in ribonucleic acid metabolism. The ergastoplasmic changes after ethionine were similar in some respects to the early lesions produced in liver parenchymal cells by fasting, to the changes occurring in animals on protein-free diets, or to some of the liver changes produced by azo dye carcinogens. The ribosomal and ergastoplasmic changes represent early morphologic expressions of the biochemical effect of ethionine.     

Local Temperature in Gastric Hypothermia

Measurements of temperatures inside the stomachs of humans by means of thermister probes introduced with the balloon used in cryotherapy indicated that the mucosa does not undergo freezing in this procedure.     

FINE STRUCTURE OF THE NEUROHYPOPHYSIS OF THE OPOSSUM (DIDELPHIS VIRGINIANA)

The neurohypophysis of the opossum (Didelphis virginiana) was studied by electron microscopy in order to amplify Bodian''s classic light microscopic observations in which he demonstrated a definite lobular pattern. The lobule of the opossum neurohypophysis is divided into three regions: a hilar, a palisade, and a septal zone. The hilar portion contains bundles of nerve fibers, the extensions of the hypothalamo-hypophyseal tract containing neurofilaments but few neurosecretory granules. In the opossum, pituicytes have a densely fibrillar cytoplasm. Herring bodies are prominent in the hilar region. They are large bodies packed with neurosecretory granules that have been described as end bulb formations of axons. From the hilar region, axons fan out into a palisade zone where the nerve terminals packed with neurosecretory granules, mitochondria, and microvesicles abut upon basement membranes. The neurosecretory granules are similar to those present in the neurohypophysis of other mammals, except for an occasional huge granule of distinctive type. Material morphologically and histochemically resembling glycogen occurs as scattered particles and as aggregates within nerve fibers. The septal zone, containing collagen, fibroblasts, and numerous small capillaries, is separated from the adjacent glandular tissue by a basement membrane.     

Red Cell Glucose-6-Phosphate Dehydrogenase Deficiency—A Newly Recognized Cause of Neonatal Jaundice and Kernicterus in Canada

Seven male newborns of Chinese, Greek and Italian origin presented with severe hemolytic jaundice due to red cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. In five, the hemolysis was precipitated by inhalation of mothball vapours in the home. Kernicterus was evident upon admission in six infants and was fatal in four of these.G-6-PD deficiency should be suspected as a cause of jaundice in all full-term male infants of these ethnic groups. The diagnosis can be confirmed in any hospital by the methemoglobin reduction test. In areas similar to Toronto, Canada, where these high-risk ethnic groups prevail, the following measures are recommended: (1) detection of G-6-PD deficient newborns by screening cord bloods of all infants of these ethnic groups; (2) protection of affected infants from potentially hemolytic agents such as naphthalene, certain vitamin K preparations, and sulfonamides; and (3) observation of serum bilirubin levels to assess the need for exchange transfusion for hyperbilirubinemia.