R. H. Rigdon

Effect of feeding benzpyrene on reproduction in the rat

Lorsque des rats sont soumis à une diète riche en benzopyrène, leurs embryons peuvent dégénerer et être résorbés. Le placenta et les membranes fétales ont une fluorescence bleue. Normalement, ces mêmes tissus ont une fluorescence rouge.

Relationship of leukemia to lung and stomach tumors in mice fed benzo (a) pyrene.

Summary CFW mice fed 0.25 mg of benzo(a)pyrene/g of food develop gastric papillomas and squamous cell carcinomas, pulmonary adenomas, and leukemia. Mice that develop leukemia have a significant increase in the number of pulmonary adenomas. There is no relationship, however, between the occurrence of pulmonary adenomas and gastric tumors in this nonleukemic group of mice.

Glycoside effect upon membrane enzymes of erythrocytes and muscle in duck myopathy

Skelettmuskelmembrane und Erythrozytenstromata normaler Enten zeigen eine adenosine triphosphatase Aktivität, die durch das herzaktive Glykosid Ouabain gehemmt wird. Das gleiche Material von Enten mit Myopathien zeigte eine durch Ouabain stimulierte ATPase-Aktivität.

Intravascular Life Span of the Duck Red Blood Cell as Determined by Radioactive Selenium

Summary Use has been made of the ability of selenium to be fixed in red blood cells to estimate the intravascular life span of the duck erythrocyte. Donor ducks were injected with sodium selenate containing radio-selenium. These ducks were then bled and the red blood cells injected into 10 young ducks. Two each of the recipient ducks were bled at various time intervals up to 10 days. It was noted that there was a linear disappearance of selenium-tagged red blood cells from the circulation of the ducks. The value of 11.7 days was found to be the intravascular life span of the duck erythrocytes under the experimental conditions described here. In correlating the relationship between the disappearance of fixed erythrocyte selenium and the destruction of the red cell certain assumptions have been made which are discussed.

Blood Volumes of Ducks Using Human Serum Albumin Labeled with Radioiodine

Summary Blood volume determinations were performed on 42 ducks of various weights, using radioiodinated human serum albumin. The blood in ml per kg body weight in young ducks weighing 150-450 g is 107 + 2.34. For the intermediate group weighing 700-1100 g it is 102 + 1.79. In young adult birds weighing 1100-2000 g it is 86.3 + 1.58. Several supplementary procedures were carried out to test the propriety of this method in the duck.

Effect of dinitrophenol on lens of chick embryo.

Summary 1) Injections of 1-25 μg of DNP into chicken eggs, prior to incubation resulted in embryonic mortality after 3 days incubation, but did not produce lens changes. 2) Injections of 25-200 μg of DNP after 5 days incubation did not produce lenticular changes. 3) Cataracts were produced in embryos and hatched chicks from eggs injected with 200-500 μg of DNP after 8 days incubation. The size of cataract was roughly the same in hatched chicks as in embryos from the 500 μg group. 4) Injection of 750 μg of DNP after 15 days incubation produced an opacity evident after 20 hours. However, the opacity apparently regressed since the eyes of chicks hatched from this group appeared to be normal.

Acid mucopolysaccharides in the liver of Pekin duck with amyloidosis.

Summary Studies on the liver involved with increasing amounts of amyloidosis and control tissues indicate that there is a marked increase in MPS content with severe amyloid infiltration. The increase of MPS was accounted for by increases in heparitin sulfate, chondroitin sulfate B, and somewhat less of chondroitin sulfates A and C. The consistent increase of heparitin sulfate in the liver of the ducks was similar to that observed in amyloidosis in humans and in experimentally induced disease. This remarkable increase of chondroitin sulfate B suggests a link to other vascular diseases and genetic connective tissue defects. The Pekin duck serves as an interesting model to study spontaneously occurring amyloidosis.

Fibroma Arising from Feather Follicle of Duck Following Local Application of Methylcholanthrene to Skin.

Summary A fibroma is described as arising from the feather follicle of White Pekin ducks following multiple local applications of methylcholanthrene to the skin.

Pancreatic fibrosis in ducks on a nutritional basis.

Summary A degeneration of the acinar cells of the pancreas as the result of a nutritional deficiency has been described. The microscopic lesion was characterized by increased acidophilia and vacuoles within the cytoplasm of the acinar cells, pyknosis and karyorrhexis, which were followed by disintegration of the acinar structure and infiltration by fibroblasts. Finally, there was anincrease in the perilobular and periacinar fibrous stroma and in some areas, large amounts of the parenchymal tissue were replaced by fibroblastic material. No changes were observed in the islet cells.

Morphologic Changes in the Dog's Adrenal Gland Following Anoxia.

Summary Dogs were given pure nitrogen to breathe and then resuscitated by lung insufflation and cardiac massage about 6 1/2 minutes after the onset of anoxia. This was at a time when breathing and circulation had failed. These animals were sacrificed at various intervals thereafter. The earliest morphological changes that occur in the adrenal glands are pyknosis of the nucleus and coagulation of the cytoplasm of epithelial cells in the zona fasciculata and zona reticularis. Subsequently, polymorphonuclear leucocytes infiltrate these areas of the cortex. A few petechiae occur. Clinical manifestations in such anoxic dogs appear to be the result of cerebral injury and not due to adrenal insufficiency.