Ultrastructural observations on fertilization and sporulation in Goussia iroquoina (Molnar and Fernando, 1974) in experimentally infected fathead minnows (Pimephales promelas, Cyprinidae)

The ultrastructural features of fertilization and sporogony of Eimeria iroquoina are described from the intestinal epithelium of experimentally infected fathead minnows (Pimephales promelas). Intact microgametes were observed in the cytoplasm of macrogametes. Within immature macrogametes the microgamete was segregated from the cytoplasm of the former by the plasma membrane of each cell plus additional membranes. Within mature macrogametes, only the plasma membranes separated the gametes. Fertilization by fusion of the limiting membrane of both gametes occurred after the entire microgamete lay within the cytoplasm of the macrogamete. The cytoplasm of the zygote cleaved into sporoblasts within cisternae of endoplasmic reticulum. The sporocystic wall was composed of an outer electron-lucent layer and an inner, thicker layer with periodic striations at right angles to the surface of the sporocyst. The sporocysts were bivalved and joined by a continuous suture. The sporozoites were morphologically similar to sporozoites and merozoites of other Coccidia. Due to the structure of the sporocyst, Eimeria iroquoina Molnar and Fernando, 1974 is amended to Goussia iroquoina (Molnar and Fernando, 1974).     

Endometrial disease after treatment with oestrogens and progestogens in the climacteric.

A prospective study of 745 women receiving different regimens of hormone treatment for the climacteric for a total of 21 736 months was performed. There was a lower incidence of endometrial hyperplasia in biopsy specimens in the women receiving cyclical low-dose oestrogen by mouth than in those receiving cyclical high-dose oestrogen by mouth. The incidence of abnormalities in the women receiving sequential oestrogen and progestogen was lower than in either of these two groups. Among the women receiving subcutaneous oestrogen implants the incidence was higher still, but over half of the abnormal specimens were from women who had not taken their progestogen. The incidence of hyperplasia fell with longer courses of progestogen, and no hyperplasia was found in patients taking progestogen for over 10 days each month. The incidence of adenomatous and atypical hyperplasia is significantly reduced by a progestogen when taken for 10 or more days monthly. The absence of vaginal bleeding or of a regular bleeding response does not guarantee histologically normal endometrium in patients taking oestrogens without progestogen.     

Structural genes of the mouse major urinary protein are on chromosome 4

The major urinary proteins (MUPs) of mouse are a family of at least three major proteins which are synthesized in the liver of all strains of mice. The relative levels of synthesis of these proteins with respect to each other in the presence of testosterone is regulated by the Mup-a locus located on chromosome 4. In an effort to determine the mechanism of this regulation in molecular terms, a cDNA clone containing most of the coding region of a MUP protein has been isolated and identified by partial DNA sequence analysis. Using a combination of hybridization analysis and somatic cell genetics, the structural gene family has been unambiguously mapped to mouse chromosome 4. These data suggest that Mup-a regulation operates in a cis fashion and that models proposing trans regulation of MUP protein synthesis are unlikely.