Aspects of luteal function in pigs and sheep

Both the luteotrophic effects of estrogen and the relative lack of luteolytic effects of PGF[subscript]2[alpha] in cycling pigs might be interpreted to suggest that luteal function in this species differs markedly from that in other domestic animals. These aspects of porcine luteal function were studied to establish the basis for this premise. Additionally, the cellular effects of PGF[subscript]2[alpha] and the activation of protein kinase C on luteal cells was investigated using dispersed ovine luteal preparations. Dispersion of ovine CL results in luteal cell preparations suitable for cell culture experiments not obtainable by similar dispersion techniques;Experiment I. Estradiol-17[beta] containing implants were placed unilaterally inside 3 individual CL of one ovary on day 11 of the estrous cycle to evaluate the direct luteal effects of this hormone in pigs following recovery of ovaries on day 19. At the highest dose of estradiol, but not in other groups, CL were maintained bilaterally with an additional significant increase in luteal weight and progesterone content in those CL receiving estradiol implants over all others;Experiment II. Estrogen implants were placed unilaterally inside all CL on an ovary on day 11 of the cycle to evaluate the functional effects of estrogen exposure for 8 days on progesterone and PGF[subscript]2[alpha] concentrations in utero-ovarian venous (UOV) blood. Estrogen induced uniform, bilateral luteal maintenance, and markedly suppressed UOV PGF[subscript]2[alpha] concentration. Luteal function appeared to decline to day 15 then recovered in estrogen-treated gilts to preinjection levels on day 19 as indicated by UOV progesterone;Experiment III. An ovary was removed from gilts on day 8 of the estrous cycle, prior to PGF[subscript]2[alpha] or vehicle administration on day 9, and the final ovary was recovered on day 12. Progesterone was monitored in systemic blood and luteal weight and content of progesterone, protein and DNA were determined in luteal tissue before and after PGF[subscript]2[alpha] exposure;Experiment IV. The effects and interaction between PGF[subscript]2[alpha], phorbol ester and calcium ionophore were investigated in day 9 dispersed oveine luteal cells by monitoring progesterone in culture medium. Phorbol ester, calcium ionophore and PGF[subscript]2[alpha] were all inhibitory at higher concentrations but none were additive in their effects. (Abstract shortened with permission of author.

Health Shocks, Insurance Status and Net Worth: Intra- and Inter-Generational Effects

An extensive literature has documented a robust correlation between socioeconomic status—measured in a variety of ways—and health outcomes; however, much uncertainty remains regarding what causal processes underlie this association. The present paper builds on a growing literature that seeks to better document how and why wealth and SES are related. Specifically, we ask the extent to which health shocks affect net worth—a less-studied dimension of socioeconomic status. Given a lack of instruments that meet the exclusion restriction, we use data from the Panel Study of Income Dynamics to pursue a first-differences identification strategy. We estimate a parameter for acute illnesses (which should have a causal effect on wave-to-wave wealth changes) and compare this coefficient to a counterfactual parameter for the presence of chronic illnesses (which we argue should be less causally related to wealth differences year-to-year). Additionally, we interact these health indicators with insurance status as a further test that the health-wealth relationship is likely causal net of covariates. Results show that the onset of an acute illness has a negative effect on family wealth levels and that the onset of chronic illnesses only makes an impact when it occurs for those uninsured. In intergenerational models, parental health insurance status also seems to matter. When parents suffer from chronic illness and have no health insurance, adult children’s net worth declines. Adult children in white families also face a greater likelihood of falling into debt (excluding wealth from home equity) when parental medical expenses increase. Together, these findings suggest that health dynamics play an important role in intergenerational stratification processes—at least under the current health regime of the United States.

Botanical research in the Galapagos islands : the last fifty years and the next fifty

We review recommendations made since the founding of the Charles Darwin Foundation in 1959, concerning botanical research for the conservation of Galapagos, and present our suggestions for priorities for the immediate future

Tissue steroid levels in response to reduced testicular estrogen synthesis in the male pig, Sus scrofa.

Production of steroid hormones is complex and dependent upon steroidogenic enzymes, cofactors, receptors, and transporters expressed within a tissue. Collectively, these factors create an environment for tissue-specific steroid hormone profiles and potentially tissue-specific responses to drug administration. Our objective was to assess steroid production, including sulfated steroid metabolites in the boar testis, prostate, and liver following inhibition of aromatase, the enzyme that converts androgen precursors to estrogens. Boars were treated with the aromatase inhibitor, letrozole from 11 to 16 weeks of age and littermate boars received the canola oil vehicle. Steroid profiles were evaluated in testes, prostate, and livers of 16, 20, and 40 week old boars using liquid chromatography/mass spectrometry. Testis, prostate, and liver had unique steroid profiles in vehicle-treated animals. Only C18 steroid hormones were altered by treatment with the aromatase inhibitor, letrozole; no significant differences were detected in any of the C19 or C21 steroids evaluated. Testis was the only tissue with significantly decreased free estrogens following treatment with the aromatase inhibitor; estrone and estradiol concentrations were lower (p < 0.05) in testes from 16, 20, and 40 week letrozole-treated boars. However, concentrations of the sulfated conjugates, estrone-sulfate and estradiol-sulfate, were significantly decreased (p<0.05) in 16 and 20 week boar testes, prostates, and livers from letrozole-treated boars. Hence, the distribution of estrogens between the free and conjugated forms was altered in a tissue-specific manner following inhibition of aromatase. The results suggest sulfated testicular estrogens are important estrogen precursors for the prostate, potentially enabling peripheral target tissues to synthesize free estrogens in the male pig

Report Regional Niagara - Proposed Town of Pelham Official Plan Amendment No. 7: Final Recommendations

The document is titled amendment No. 7 to proposed Town of Pelham official plan. Included in the document are letters from the Town of Pelham and the Ontario Ministry of Agriculture and Food

Immunolocalization of steroidogenic enzymes in the vaginal mucous of Galea spixii during the estrous cycle.

BackgroundThe synthesis of sex steroids is controlled by several enzymes such as17α-hydroxylase cytochrome P450 (P450c17) catalyzing androgen synthesis and aromatase cytochrome P450 (P450arom) catalyzing estrogen synthesis, both of which must complex with the redox partner NADPH-cytochrome P450 oxidoreductase (CPR) for activity. Previous studies have identified expression of steroidogenic enzymes in vaginal tissue, suggesting local sex steroid synthesis. The current studies investigate P450c17, P450aromatase and CPR expression in vaginal mucosa of Galea spixii (Spix cavy) by immuno-histochemical and western immunoblot analyses.MethodsStages of estrous cyclicity were monitored by vaginal exfoliative cytology. After euthanasia, vaginal tissues were retrieved, fixed and frozen at diestrus, proestrus, estrus and metestrus. The ovaries and testis were used as positive control tissues for immunohistochemistry.ResultsData from cytological study allowed identification of different estrous cycle phases. Immunohistochemical analysis showed different sites of expression of steroidogenic enzymes along with tissue response throughout different phases of the estrous cycle. However, further studies are needed to characterize the derived hormones synthesized by, and the enzymes activities associated with, vaginal tissues.ConclusionCurrent results not only support the expression of enzymes involved in sex steroid synthesis in the wall of the vagina, they also indicate that expression changes with the stage of the cycle, both the levels and types of cells exhibiting expression. Thus, changes in proliferation of vaginal epithelial cells and the differentiation of the mucosa may be influenced by local steroid synthesis as well as circulating androgens and estrogens

Evaluation of Handheld Assays for the Detection of Ricin and Staphylococcal Enterotoxin B in Disinfected Waters

Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs) in detecting ricin and Staphylococcal Enterotoxin B (SEB) in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO) with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD) were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured