L. F. Cavazos

THE FINE STRUCTURE OF THE HAMSTER SEMINAL VESICLE WITH SPECIAL REFERENCE TO PIGMENT FORMATION.

SummaryThis study describes the fine structure of the hamster seminal vesicle. Intact, sexually mature young and aged animals were used to obtain the results presented. The epithelium of the hamster seminal vesicle contains numerous large electron-dense structures, with a single limiting membrane, with many internal granules and, in the aged animals, myelin-like figures. Based on histochemical results presented in this study, and those of others, it is suggested that this material is a lipofuscin pigment. This substance is of special interest inasmuch as in the hamster seminal vesicle epithelium, pigment is a more sensitive indicator of circulating androgen than is, as in the case of the rat seminal vesicle, regression of cell height. It is possible that this pigment takes origin as breakdown products of mitochondria, the endoplasmic reticulum and the Golgi apparatus. The relation of “pro-pigment granules” and lysosomes is discussed. Results indicate that pigment is formed at sites of increased catabolism in response to a biological insult to the cell.

Comparative Study of Lipids in Vertebrate Testes.

Summary 1. Comparative histochemical study of vertebrate testes was carried out on sexually mature males representing the classes Mammalia, Aves, Reptilia, Amphibia, and Pisces. Lipids were examined as to their morphological localization in the bull, ram, boar, rat, guinea pig, rooster, the horned lizard, Phrynosoma cornutum (Harlan), the frog, Rana pipiens, and the bluegill fish, Lepomis macrochirus Rafinesque. 2. Following the use of Sudan dyes, lipids were observed in the interstitial cell cytoplasm, the basement membrane, and the cytoplasm of the Sertoli cells, spermatogonia, spermatocytes, and spermatids of all species studied with the exception of the bluegill fish. In the bluegill, lipids were visible in the germ cells and in the interlobular connective tissue sheath. A reaction for carbonyl groups was obtained suggesting the presence of ketosteroid material in the Leydig cells of all species examined, except in the case of the boar, rooster, and fish. With the aid of Bakers acid hematin test, phospholipid was found in the testicular cell types of the species studied. This method was not applied to the bluegill fish testis. Schultz-positive material was noted in the Leydig cells of the bull, ram, boar, rat, guinea pig, horned lizard, and frog. Birefringent digitonides were present in the Leydig cells and seminiferous tubules of the frog. 3. The similarity in the patterns of lipid distribution in the testis of closely related vertebrate species, and those species which are more distant in taxonomic relationship, suggests the structural and metabolic importance of lipids in spermatogenesis as well as in the function of Sertoli and interstitial cells.

Restructuring Education and Its Impact on Medical Education.

Abstract The United States has an education deficit that in the long term may be more harmful to the country than the serious budget and trade deficits. U.S. students are far less prepared in mathematics, chemistry, and physics than are their counterparts in Western Europe and Japan. The dropout rate among high school students, and the high and increasing rate of functional illiteracy, blight lives and represent an enormous economic loss to the nation. American education must be restructured at all levels so that local and federal funds can be used flexibly to pursue revised educational goals. Students and their families should be allowed to choose their elementary and secondary schools, and school management should be decentralized and more rooted in the community. The medical profession must become involved in elementary and secondary education, and medical faculty must be involved in their communities. Further, medical faculty must encourage minority students at all educational levels, must recruit minority medical students, and must increase the number of minority faculty members. Acad. Med. 65(1990):230–233.

Cytochemistry of Male Reproductive Tract in Scurvy and Inanition.

Summary Histochemical studies were conducted on effects of avitaminosis C on the reproductive tract of the male guinea pig, and an attempt was made to differentiate these changes from those which result from inanition in the presence of an adequate dietary intake of ascorbic acid. Results indicate that scurvy may cause an inability to utilize other essential dietary substances resulting in more severe cachexia than that noted in inanition controls. These studies suggest that changes in the cytochemistry of the Golgi apparatus are involved in spermatogenic arrest. Furthermore, as noted in this investigation, the relation of scurvy and/or inanition to reproductive physiology is indicated by altered carbohydrate metabolism in testes and seminal vesicles. These changes were more marked in scorbutic animals than in inanition controls.

A message to the 1989 medical graduates.

No abstract available.

Composition of Rat Seminal Vesicles and Effects of Testosterone Propionate on Lipid distribution.

Summary In sexually immature rats (wt 77 g) the seminal vesicles weighed 2.1 mg (dry wt0 and contained 0.3 mg total N and 0.1 mg lipid, whereas in sexually mature animals (wt 386 g) the glands weighed 394 mg with 59.5 mg N and 4.7 mg lipid. A diffuse cytoplasmic sudanophilia was observed in the columnar epithelium of the seminal vesicles of sexually mature males. Following castration there was a marked accumulation of lipid in the basal end of the cuboidal cells. The administration of testosterone propionate caused the diffuse sudanophilia to appear. Phospholipid was observed in the secretory granules. A marked reduction in phospholipid reaction was observed following gonadectomy due to the disappearance of the granules. A marked increase in the granules and associated phospholipid reaction was noted following hormone replacement.