Regionally specific modulation of brain apolipoprotein E in the mouse during the estrous cycle and by exogenous 17beta estradiol.

Studies have suggested that 17beta estradiol (E2) can modify apolipoprotein E (apoE) expression. The current study determined if apoE protein varied in different regions of the mouse brain as a function of the estrous cycle and if E2 could increase apoE protein expression. In this study apoE concentration was lowest on estrus in the hippocampus, cingulate cortex and frontal cortex. In contrast, apoE concentration was highest on estrus in the olfactory bulb and cerebellum. There were no differences in the striatal apoE expression throughout the estrous cycle. Exogenous E2 significantly raised tissue levels of apoE in the olfactory bulb and cerebellum at 5 days after treatment. There was a slight, but nonsignificant increase in cortical expression of apoE and no change in striatum. Immunocytochemical localization studies found estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) in cortical neurons and glia. In the cerebellum and olfactory bulb, ERbeta was seen primarily in glia. ERalpha was not observed in the cerebellum and was rare in the olfactory bulb. Neither ERalpha nor ERbeta was seen in the striatum. Our data show regional differences in the production of apoE throughout the estrous cycle. In addition, exogenous E2 has regionally specific effects on apoE expression. Regional variability in apoE production appears to vary as a function of the estrogen receptor subtype.

Effects of hormone replacement therapy on olfactory sensitivity: cross-sectional and longitudinal studies.

OBJECTIVE: To determine whether hormone replacement therapy (HRT) preserved or improved olfactory sensitivity in healthy postmenopausal women. METHODS: Sixty-two postmenopausal women participated in a cross-sectional study of olfactory sensitivity involving detection, intensity discrimination, quality discrimination and two measures of quality recognition. In addition, 24 postmenopausal women participated in a longitudinal study of olfactory sensitivity. This study allowed for the measurement of estrogen effects (while holding practice effects constant) and the measurement of practice effects (while holding HRT conditions constant). RESULTS: In the cross-sectional study, we were unable to detect any differences between those receiving HRT and those not receiving HRT. Duration of exposure to HRT was examined by selecting women who had 5 or more years of exposure to their HRT regimen. Even after the data were reorganized into those for opposed- and unopposed-estrogen use, we were unable to detect any differences. However, olfactory threshold increased as a function of increasing age, regardless of HRT status. A gradual decrease in ability to detect odors was observed from the 4th to the 6th decade, with a greater decrease between the 6th and 7th decades. In the longitudinal study, no effects of HRT were detected even when practice effects were uncontrolled. Practice effects were assessed both between and within subjects. No effects of practice were detected when initial baseline performance was used as a covariate. CONCLUSION: Although prophylactic HRT has been suggested to be associated with improved olfactory function, we find that its use in healthy postmenopausal women does not enhance performance in a wide range of olfactory tasks.

Endoglin expression as a measure of microvessel density in cervical cancer.

OBJECTIVE: To evaluate endoglin, a membrane protein and member of the transforming growth factor beta-1 receptor complex, as an endothelial marker of angiogenesis in cervical cancer tissues. METHODS: Tumor tissue was collected from 31 surgically treated stage IB nonbulky (under 5 cm) cervical cancer subjects, and samples were fixed in formalin and embedded in paraffin. Endoglin was stained on 5-microm slide sections by the DAKO Catalyzed Signal Amplification method (DAKO Corporation, Carpinteria, CA). Factor VIII was stained by standard immunohistochemistry. Positively stained microvessels were counted in "hot spots" at 200x magnification. Clinical data were correlated with vessel counts by Spearman correlation. Mean differences in counts were tested using paired t tests. RESULTS: This staining method for endoglin identified significantly more vessels than the factor VIII method (mean 92 +/- 45 versus 33 +/- 16, P <. 001). Endoglin and factor VIII counts correlated significantly with deep stromal invasion (Spearman rho 0.466 and 0.522, respectively, P <.05); however, only endoglin counts correlated significantly with lymph node metastases (rho =.495, P <.01). CONCLUSION: Endoglin is stimulated in tumor angiogenesis and might be relatively more specific than commonly used endothelial markers. The endoglin system was more sensitive for staining capillaries in neoplastic cervical tissue, better predicted lymph node metastases, and should be widely applicable for the study of other tumors.

An essential role for ovarian inhibin in pineal gland-mediated anestrus in Syrian hamsters.

When transferred from long photoperiod (LP) to short photoperiod (SP), female Syrian hamsters exhibit depressions of follicle stimulating hormone (FSH) and follicular development, cessation of ovulation, and marked ovarian interstitial tissue hyperplasia. Pinealectomy prevents these effects of SP. The object of this study was to determine the role of inhibin in the regulation of FSH during SP-induced anestrus. Adult LSH/SsLak hamsters maintained in LP (LD 14:10 hr) were transferred to SP (LD 8:16 hr) on the day of estrus, and groups of animals killed at either 16.00 hr on proestrus or 08.00 hr on estrus during each of five consecutive 4-day estrus cycles after transfer. Groups of females that became anestrus in SP were killed either at 08.00 or 16.00 hr, 12 days after the last observed estrus discharge. Compared to LP controls, serum FSH levels on estrus increased significantly (P<0.01) during the first two cycles in SP before declining to concentrations that were significantly lower than control values (P<0.01). Serum inhibin levels increased significantly by the third, fourth, and five days of estrus in SP. Regression analysis revealed a significant inverse correlation between serum inhibin and FSH levels on estrus during SP exposure (P=0.021) but not on proestrus. Relative levels of inhibin alpha- and betaA-subunit mRNAs were lower in ovaries from SP proestrus and anestrus females killed at 16.00 hr as compared to those from proestrus LP controls; they were elevated in ovaries from SP estrus and anestrus females killed at 08.00 hr compared to those from estrus LP controls. The absence of antral follicles on estrus in the last cycles of SP and anestrus suggests that the increase in circulating inhibin and inhibin mRNAs may be derived from hyperplastic interstitium. These observations suggest that inhibin may play an essential role in suppressing FSH secretion during pineal gland-mediated anestrus in Syrian hamsters.

Inhibin-A and pro-alpha C are elevated in preeclamptic pregnancy and correlate with human chorionic gonadotropin.

PROBLEM: Serum concentrations of the heterodimeric glycoprotein inhibin-A (alpha-beta A) and its alpha-subunit increase during pregnancy. The placenta is the predominant source of inhibin during pregnancy, and a paracrine role in the trophoblast has been suggested. Elevated serum concentrations of inhibin alpha-subunit as well as the glycoprotein human chorionic gonadotropin (hCG) have been described in preeclamptic pregnancy. The objectives of this investigation were to compare serum concentrations of inhibin-A and inhibin pro-alpha C in preeclamptic and normotensive pregnancy, and to examine the relationship of hCG and inhibin-A in those pregnancies. METHOD OF STUDY: A case-control design using 32 patients with preeclampsia with a single fetus at 32-40 weeks of gestation and 34 gestation age-matched normotensive control subjects was used for this investigation. Solid-phase enzyme-linked immunosorbent assays were used to measure inhibin-A and inhibin pro-alpha C in sera. An immunoradiometric assay was used to measure intact hCG. RESULTS: Inhibin-A and inhibin pro-alpha C concentrations were significantly elevated in the sera of women with preeclampsia compared with those concentrations in normotensive control subjects (P < 0.05). A relationship of inhibin-A or pro-alpha C with severity of preeclampsia was not observed. There was a significant positive correlation of serum hCG with both inhibin-A and pro-alpha C (P < 0.05). CONCLUSIONS: Levels of inhibin-A and the subunit pro-alpha C are increased in pregnancies complicated by preeclampsia. These findings are potentially the effect of a paracrine role of inhibin-A in the development and proliferation of the trophoblast.

Involvement of apoptosis in 4-vinylcyclohexene diepoxide-induced ovotoxicity in rats.

Previous studies have determined that 4-vinylcyclohexene diepoxide (VCD) causes specific destruction of oocytes contained in small pre-antral (primordial and primary) ovarian follicles of Fischer 344 rats following 30 days of daily dosing with VCD. The purposes of this study were to identify the type of VCD-induced cell death occurring in small pre-antral follicles and to determine the earliest time following the onset of dosing when evidence of follicular destruction could first be detected. A significant decrease in the number of oocytes contained in small pre-antral follicles in ovaries of rats after 15 days of daily dosing (ip) with VCD (80 mg/kg) had been observed in preliminary experiments. Therefore, a study was conducted to determine the time of the onset of this follicular destruction by examination of follicular DNA integrity. Female Fischer 344 rats were dosed daily (80 mg/kg, i.p.) for 6, 8, 10, 12, or 14 days, and ovaries were removed 1, 4, or 24 hr after the final dose. Small pre-antral follicles (25-100 microns) were isolated by gentle dissociation of ovaries with collagenase, and follicles were sorted with micropipets. Genomic DNA was isolated from follicles and radiolabeled with [32P]dideoxy ATP, and the degree of fragmentation quantified by agarose gel electrophoresis and autoradiography. Degradation of DNA was evaluated by 32P content in low-molecular-weight fragments ( < 4 kilobase pairs). Degradation of DNA was not observed in follicles collected 24 hr after the final dose on any day. However, a random pattern of DNA degradation was observed, and was significantly greater (p < 0.05) compared with controls, when follicles were collected 4 hr following VCD administration on Days 10 and 12, but not on Days 6 or 8, of dosing. Although not significant, there was also evidence of DNA degradation in dosed animals on Day 14. Histological evaluation of small pre-antral follicles in ovarian sections during the early stages of VCD-induced DNA degradation (Day 10; 4 hr) demonstrated margination of chromatin along the nuclear membrane in oocytes and disruptions in focal contact between granulosa cells and oocytes, both features indicative of apoptosis. Furthermore, there was no sign of ruptured membranes in granulosa cells or oocytes or of an inflammatory response, characteristics of necrosis (pathological cell death). Whereas biochemical and morphological evidence of follicular destruction was seen 4 hr after dosing on Day 10, numbers of oocyte-containing primordial and primary follicles in VCD-treated animals were not different from controls at that time. These results demonstrate that the initial evidence of impending destruction of small pre-antral follicles is first consistently visualized following 10 days of daily dosing with VCD, although a measurable reduction in oocyte numbers has not yet occurred. Despite the fact that internucleosomal cleavage of genomic DNA was not observed, morphological evaluations support that granulosa cells and oocytes in primordial and primary follicles are destroyed via the induction of apoptosis.

Immunoreactive inhibin decreases following bilateral ovariectomy and during the postovulatory rise of FSH in Syrian hamsters.

Inhibin is a heterodimeric glycoprotein which may regulate FSH synthesis and secretion as well as follicular development and maturation. The source and physiological role of inhibin have not been established for the hamster, although several investigators have suggested that this hormone may function in the regulation of FSH in this species. The major objectives of the present studies were to develop a radioimmunoassay (RIA) for the measurement of inhibin in hamster serum and tissue, to identify the primary source of inhibin and to examine the relationship between inhibin and FSH during the estrous cycle. A sensitive, accurate and specific RIA was developed and utilized to measure changes in circulating levels of immunoreactive inhibin (ir-inh-alpha) following bilateral gonadectomy and throughout the estrous cycle. Circulating ir-inh-alpha declined rapidly and significantly following bilateral gonadectomy in female hamsters suggesting a gonadal source. Serum FSH concentrations increased following the decline in serum ir-inh-alpha levels. In the adult female hamster circulating ir-inh-alpha increased gradually throughout diestrus, peaked at the time of the preovulatory gonadotropin surge, then declined to a nadir on the morning of estrus. Changes in ovarian inhibin subunit mRNAs were examined throughout the estrous cycle and correlated with changes observed in circulating ir-inh-alpha levels. Observed significant reductions in the relative amount of inhibin mRNAs and serum concentrations of ir-inh-alpha during early estrus may moderate the amount and duration of the secondary FSH rise and thus contribute to the regulation of follicle recruitment in the hamster.

Diagnosis of ectopic pregnancy: endovaginal vs transabdominal sonography.

During a 25-month period, 193 women with the clinical diagnosis of suspected ectopic pregnancy had transabdominal and endovaginal sonograms. Most had quantitative determinations of serum human chorionic gonadotropin (HCG). Endovaginal sonography was diagnostic of ectopic pregnancy in 23 (38%) of the 60 patients with surgically proved ectopic pregnancies: transabdominal sonography was diagnostic in 13 patients (22%). All 83 intrauterine pregnancies were identified with endovaginal sonography, compared with 34 identified with transabdominal sonography. Endovaginal sonography was somewhat more helpful in the diagnosis of missed abortion and blighted ovum. Eighty endovaginal sonograms were classified as indeterminate as compared with 141 transabdominal studies. This indeterminate group included patients with complete abortions, ectopic pregnancies without sonographic evidence of an extrauterine gestation, incomplete abortions, and patients with subsequent negative serum levels. As in prior reports, endovaginal sonography was superior to transabdominal sonography in the evaluation of suspected ectopic pregnancies. Overall, endovaginal sonography was diagnostic in 113 patients, whereas transabdominal sonography was diagnostic in 52 patients. The finding of an extrauterine fetal pole or embryo was diagnostic for an ectopic pregnancy. Pelvic fluid, the appearance of the endometrium, and a single positive serum HCG determination were not helpful in making the diagnosis of ectopic pregnancy.

Inability of sonography to detect imminent ovulation.

Sonographic visualization of the cumulus oophorus or of morphologic alterations in the wall of the dominant follicle have been reported to be reliable signs of imminent ovulation when conventional transabdominal sonography is used. To determine if transvaginal sonography could allow a more frequent and confident prediction of imminent ovulation, we prospectively monitored 22 ovulatory menstrual cycles in four women undergoing artificial insemination and in 13 normally menstruating volunteers. Scanning was done on alternate days in the periovulatory period; a 7.5-MHz transvaginal transducer was used. Despite the improved resolution obtained with transvaginal sonography, confident identification of the cumulus oophorus or of mural changes in the follicle was not possible in any of the cycles followed. No other consistent follicular characteristic predicted imminent ovulation. We conclude that confident prediction of imminent ovulation is not possible with sonographic analysis.

The role of arginine vasotocin and prostaglandin F2 alpha on oviposition and luteolysis in the common snapping turtle Chelydra serpentina.

The administration of arginine vasotocin (AVT) to gravid snapping turtles with steroidogenically active corpora lutea and high plasma progesterone concentration (1480 +/- 155 pg/ml) did not trigger oviposition, whereas 12 days after ovulation when luteolysis occurred and plasma progesterone concentration was low (570 +/- 78 pg/ml), treatment with AVT caused oviposition. Controls with high plasma progesterone concentration (1605 +/- 185 pg/ml) oviposited 15-23 days after ovulation when plasma progesterone concentration dropped to 201 +/- 35 pg/ml. Deluteinization-induced oviposition was initiated 15 hr after surgery and was completed by 30 hr. Oviposition of complete clutches occurred and was correlated with a significant drop in plasma progesterone. Sham-operated turtles did not exhibit oviposition and no significant change in progesterone concentration was observed. A single injection of prostaglandin F2 alpha (PGF) in recently ovulated turtles induced early luteolysis and a significant decrease in plasma progesterone concentration after 24-30 hr. A single administration of PGF caused the disappearance of steroidogenic features such as the smooth endoplasmic reticulum and mitochondria with tubular cristae 48 hr later. Also PGF triggered the invasion of a hyaline-like material from the luteal theca into the luteal cell mass which eventually induced luteolysis. The role of AVT, PGF, and progesterone in relation to egg retention and oviposition is discussed.

Serum and seminal plasma prolactin concentrations in men with normospermia, oligospermia, or azoospermia.

Semen analyses were performed and serum and seminal plasma prolactin (PRL) concentrations were determined in 165 samples from 120 men seen with their wives because of infertility. The mean (+/- standard deviation) serum and seminal plasma PRL concentrations were 6.5 +/- 3.3 and 7.5 +/- 3.1 ng/ml, respectively. The mean concentrations of PRL in serum and seminal plasma were similar in groups of men divided by sperm concentration. Seven men had an increased serum PRL concentration. Three of these 7 men had sperm concentrations less than 20 million/ml and none of these 7 men had an increased seminal plasma PRL concentration. Four men had an increased seminal plasma PRL concentration; the serum PRL concentration, sperm concentrations, and motilities were normal in all 4. No man had a decreased serum or seminal plasma PRL concentration. Increased serum PRL concentrations were found infrequently and the increase was slight (23.2 ng/ml or less). Seminal plasma PRL concentrations were related directly to sperm concentrations and motilities, relationships that were statistically significant.