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Biomedical subjects

W J Swartz

Publications and source records attributed to W J Swartz.

34 records · Page 2Linked to original sources
PubMed1979

A syndrome characterized by recurrent symptomatic functional ovarian cysts in young women.

A syndrome characterized by the persistent recurrence of symptomatic functional ovarian cysts, elevated plasma estradiol levels, and infertility in four young patients is described. Two of the patients experienced recurring ovarian cysts following total abdominal hysterectomy and bilateral salpingo-oophorectomy. Pathologic findings confirmed the presence of ovarian tissue in all cysts. Recurrent cysts formation is attributed to either an increased production of gonadotropins or a hypersensitive response to normal gonadotropins. The development of recurrent cysts following bilateral oophorectomy indicates that some ovarian or "ovarian-like" tissue is present within the pelvic cavity, anatomically unrelated to the normally positioned ovaries. This extraovarian tissue may become sensitive to circulating gonadotropin levels in the absence of normal ovarian tissue. The source of this extraovarian tissue is discussed from an embryologic standpoint.

Adolescent↗
PubMed1979

Enzyme histochemical investigation of glycol methacrylate embedded chick embryonic tissue.

The advantages of the water-soluble glycol methacrylate (GMA) embedding procedure make it highly applicable for use with fragile early embryonic material. Not only can one obtain tissue sections containing excellent histological detail, but numerous enzymes are retained for subsequent histochemical localization. For the purpose of establishing a methodology whereby concomitant histology and histochemistry could be obtainable, various fixatives and fixation times have been evaluated on GMA embedded chick embryonic mesonephros and gonad. It was found that fixing the tissues for 1 h in a solution of 95% ethanol, 5% acetic acid and 10% neutral-buffered formalin resulted in the retention of not only excellent histology but also alkaline and acid phosphatase. Thus, with this procedure, more specific investigations of early embryonic tissue can be performed.

Acetates↗
PubMed1979

Histologic investigation of glycol methacrylate embedded chick embryonic tissue.

Specific light microscopic investigations (i.e. histochemical) of early embryonic material have always been beset by difficulties in processing and obtaining tissue sections of good quality. The advent of glycol methacrylate (GMA) as an embedding medium now provides a means to overcome these inherent problems with this tissue. Investigations were carried out to assess the histological results produced by different fixatives and times of fixation of GMA embedded 5-day chick embryonic tissue. Optimum cellular preservation of all tissues occurred following fixation in a mixture of acetic acid, 95% ethanol and neutral buffered formalin (AAF). With the procedures described in this study, a new method is available for more comprehensive examination of all types of early embryonic material.

Acrylates↗
PubMed1978

The use of ultrasonication to remove non-specific precipitate.

The non-specific artifactual precipitate found in glycol methacrylate (GMA) embedded tissues, following acid phosphatase histochemical incubation, can now be eliminated with brief ultrasonication. A treatment of 1 to 2 min totally eliminated the artifactual residue, leaving the true histochemical reaction product and the physical integrity of the tissues intact. With this technique, most loosely bound precipitates, which clutter and mask GMA or conventionally embedded tissues, may now be treated and eliminated.

Acid Phosphatase↗
PubMed1975

Effect of steroids on definitive localization of primordial germ cells in the chick embryo.

It has been suggested that PGCs are attracted to developing gonads by a chemotactic-like agent secreted by the gonads and that this agent might be steroidal in nature. This study was undertaken to ascertain whether specific exogenous steroid hormones exert an influence on germ cell colonization of the gonads, by enhancing, inhibiting or otherwise interfering with it. Testosterone cypionate in cottonseed oil, crystalline testosterone propionate, estrone in aqueous suspension and crystalline estradiol-17beta were adminstered to chick embryos at 33 hours incubation. Normally developed embryos, those receiving cottonseed oil (vehicle for testosterone cypionate) and those receiving cholesterol served as controls. A decrease in the number of germ cells in the gonadal area at five days of incubation occurred in all groups receiving the androgens and estrogens. However, in only one group (that receiving testosterone cypionate) was this decrease found to be significant. The mean number of germ cells found in the cottonseed oil controls and the cholesterol controls closely paralleled that of the normally developed controls. Normal asymmetry in the distribution of the germ cells favoring the left side in the chick was not affected in any of the groups; however, the percentage distribution of the germ cells between the right and left gonads at this early stage appeared to be affected.

Androgens↗
PubMed1975

Morphological diversity of oocytes released from the adult mouse ovary.

This study was designed to classify and differentiate the population of oocytes released from the mouse ovary by mechanical means. Liberated oocytes were classified on the basis of their number, size and by the nature of the attachment of follicle cells to these oocytes. Microscopical examination of oocytes mechanically released from the ovaries revealed three distinct morphological classifications of oocytes: (1) those completely devoid of follicle cells, (2) those encased in follicle cells and (3) those in the process of degeneration. Ooxytes ranged in size from approximatley 30mu to 119mu. Those oocytes surrounded by follicle cells could be further subdivided into two groups depending on whether the follicle cells could be mechanically removed from the oocyte. These data demonstrate that the adult ovary contains a variety of classes of oocytes which differ in size and in the extent to which the follicle cells are attached to the oocytes. It is suggested that the metabolic activities and meiotic potnetials of the various oocyte populations differ and as a result, care should be employed to insure a uniform population of oocytes when conducting further studies sith mechanically liberated oocytes.

Animals↗
PubMedDate not supplied

Response of adult murine uterine epithelium to 50% methoxychlor.

This study was designed to assess the response of uterine epithelia of adult mice to a 4-week exposure of 50% methoxychlor (MXC) to ascertain whether significant changes were induced by 50% MXC that might compromise future implantation. Sexually mature virgin female mice were exposed to 0.1, 0.5, 1.0, 2.5, or 5.0 mg MXC via oral gavage for 5 consecutive days for 4 weeks. Controls received either sesame oil or 25 micrograms estradiol-17 beta (E-17 beta) also by gavage. At sacrifice, segments from each uterine horn were prepared for morphometric studies or for transmission electron microscopy. Results revealed a dose-dependent increase in the heights of uterine epithelial cells. Epithelial cell heights of the two groups treated with the highest doses of the pesticide were similar to that of the E-17 beta-treated group. Electron microscopy revealed increased vacuolization and swelling of mitochondria in cells of the 2.5 and 5.0 mg treated groups when compared to either of the control groups. In addition, there were effects on the number and size of microvilli in the uterine epithelial cells. The present study clearly demonstrates that a 4-week exposure of adult female mice to 50% MXC elicits significant estrogenic and toxic effects on the uterine epithelium.

Animals↗
PubMedDate not supplied

Decreased superovulation in adult mice following neonatal exposures to technical methoxychlor.

To examine the effects of technical methoxychlor (MXC) on superovulation, neonatal mice received intraperitoneal (i.p.) injections of either sesame oil, 10 micrograms of estradiol 17 beta, or 0.1, 0.5, or 1 mg of technical MXC. At 2 and 4 months, half of the mice received a superovulatory regimen of 10 IU pregnant mare's serum gonadotropin followed by 10 IU human chorionic gonadotropin. The mice were sacrificed 15 to 20 h later, the number of ovulated oocytes were counted, and the ovaries were removed for histology. In the lowest MXC dose, the ovaries appeared normal and at 2 months, ovulated the same number of oocytes as controls. Estradiol or the highest two MXC doses induced ovarian atrophy. Following gonadotropin injections, these ovaries also ovulated oocytes. However, the number of oocytes recovered from experimental mice exhibited a time- and dose-dependent decline, and by 4 months, their number was significantly reduced. Neonatal exposures to MXC reduces ovulatory rates and ovarian functions in adults.

Animals↗
PubMedDate not supplied

Neonatal exposure to technical methoxychlor alters pregnancy outcome in female mice.

This study was designed to determine the ability of female mice who were exposed neonatally to the pesticide methoxychlor (MXC) to mate, ovulate, and become pregnant upon reaching sexual maturity. One-day-old female mice (5 to 8/group) were exposed daily by intraperitoneal (ip) injection for 14 d to either sesame oil or 10 microg estradiol-17beta or 0.1, 0.5 or 1.0 mg MXC suspended in sesame oil. The MXC exposures corresponded to 14 to 71, 68 to 357, or 135 to 714 mg/kg body weight, respectively. Three months later, female mice were placed with proven breeder males and checked daily for vaginal plugs. Mated female mice were sacrificed 18 d after the appearance of a vaginal plug to evaluate pregnancy. Uteri were examined for the presence of living fetuses and/or resorption sites. Ovaries were removed and prepared for histologic evaluation and tabulation of corpora lutea. All mice from all three MXC-treated groups did in fact mate, in comparison with only one of those exposed neonatally to estradiol. Increasing the dose of MXC produced a decreased number of pregnant animals at 18 d following mating. The mean number of live fetuses/litter was reduced in the 0.5 and 1.0 mg MXC-treated groups. Corpora lutea were significantly reduced in ovaries from only the 1.0 mg MXC group and the estradiol group. No effects of treatment were seen at 0.1 mg MXC. It is concluded that neonatal exposure to MXC does not interfere with mating. Instead, significant alterations are seen in initiating and/or maintaining pregnancy. The deleterious effects on pregnancy may be due to the influence of neonatal MXC treatments on the hypothalamic-pituitary-ovarian axis as well as on possible alteration of the uterine environment.

Animals↗