"Figuring out your place at a school like this:" Intersectionality and sense of belonging among STEM and non-STEM college students.

BACKGROUND: Students' sense of belonging in college-an individual's feelings of contentment, mattering, importance, and "finding one's place" in a social setting-can influence choice of major and career trajectory. We contribute to the belongingness literature through a mixed methods intersectional study of students attending a STEM-focused public university we call Meadow State University (MSU). We assess the potential for students' intersecting social identities to differentially influence their experiences with intersectional oppression-subjection to multiple systems of oppression due to simultaneous membership in more than one marginalized group-that, in turn, may influence their college pathways. In addition, we explore whether intersectional differences affect sense of belonging differently in STEM and non-STEM majors. We employ a mixed-methods approach, informed by critical quantitative methods and in-depth interviews. We utilize quantitative institutional data measuring college satisfaction, expressed as "willingness to return" to the same university, for over 3,000 students during two academic years (2013-14 and 2016-17). Survey data explores college satisfaction as an indicator of intersectional differences in student experiences. Then, we analyze 37 in-depth interviews, collected between 2014-2016 at the same institution, to further contextualize the intersectional variation suggested by survey results. RESULTS: Willingness to return is influenced by major, as well as academic, social, and campus belonging. Moreover, the extent to which these factors affected outcomes additionally varied by race/ethnicity, gender, family income, other background factors, and the ways these factors may intersect. Important components of academic belonging included faculty-student interactions, perceptions of academic support, and a privileging of STEM degree programs and students over non-STEM students and their degree programs at MSU. Faculty responsiveness and high impact practices like internships played an important role, particularly in STEM programs. Taken together, our findings demonstrate that, particularly for students of color and those subject to intersectional oppression due to multiple marginalized identities, satisfaction with academics did not always outweigh deficiencies in other areas of campus life shaping belongingness. CONCLUSIONS: Our mixed-methods approach contributes insights into how and why students' background, individual choices, and institutional practices concurrently-and intersectionally-influence their ability to form a sense of belonging on campus. Structural changes are required to end practices that support intersecting systems of oppression by favoring White, upper-income men as the "default" STEM students in the U.S. Our research supports growing evidence that institutions must actively build models of inclusion for underrepresented and marginalized groups that address inequitable and unjust practices, providing transformative mentoring and educational guidance that attends to intersectional oppression, in order to effectively support the next generation of women and scholars of color.

Systemic advantage has a meaningful relationship with grade outcomes in students' early STEM courses at six research universities.

Background: Large introductory lecture courses are frequently post-secondary students' first formal interaction with science, technology, engineering, and mathematics (STEM) disciplines. Grade outcomes in these courses are often disparate across student populations, which, in turn, has implications for student retention. This study positions such disparities as a manifestation of systemic inequities along the dimensions of sex, race/ethnicity, income, and first-generation status and investigates the extent to which they are similar across peer institutions. Results: We examined grade outcomes in a selected set of early STEM courses across six large, public, research-intensive universities in the United States over ten years. In this sample of more than 200,000 STEM course enrollments, we find that course grade benefits increase significantly with the number of systemic advantages students possess at all six institutions. The observed trends in academic outcomes versus advantage are strikingly similar across universities despite the fact that we did not control for differences in grading practices, contexts, and instructor and student populations. The findings are concerning given that these courses are often students' first post-secondary STEM experiences. Conclusions: STEM course grades are typically lower than those in other disciplines; students taking them often pay grade penalties. The systemic advantages some student groups experience are correlated with significant reductions in these grade penalties at all six institutions. The consistency of these findings across institutions and courses supports the claim that inequities in STEM education are a systemic problem, driven by factors that go beyond specific courses or individual institutions. Our work provides a basis for the exploration of contexts where inequities are exacerbated or reduced and can be used to advocate for structural change within STEM education. To cultivate more equitable learning environments, we must reckon with how pervasive structural barriers in STEM courses negatively shape the experiences of marginalized students. Supplementary Information: The online version contains supplementary material available at 10.1186/s40594-024-00474-7.

Integrating Critical Approaches into Quantitative STEM Equity Work.

The recent anti-racist movements in the United States have inspired a national call for more research on the experiences of racially marginalized and minoritized students in science, technology, engineering, and mathematics (STEM) fields. As researchers focused on promoting diversity, equity, and inclusion, we contend that STEM education must, as a discipline, grapple with how analytic approaches may not fully support equity efforts. We discuss how researchers and educational practitioners should more critically approach STEM equity analyses and why modifying our approaches matters for STEM equity goals. Engaging with equity as a process rather than a static goal, we provide a primer of reflective questions to assist researchers with framing, analysis, and interpretation of student-level data frequently used to identify disparities and assess course-level and programmatic interventions. This guidance can inform analyses conducted by campus units such as departments and programs, but also across universities and the scientific community to enhance how we understand and address systemic inequity in STEM fields.

Perceived COVID-19 health threat increases psychological distress among Black Americans.

The present study used data from the American Trends Panel to examine the interplay between the perceived COVID-19 health threat, discriminatory beliefs in medical settings, and psychological distress among Black Americans. We measured psychological distress as an average of five items modified from two established scales and used self-reports of perceived COVID-19 health threat and beliefs about discrimination in medical settings as focal predictors. Ordinary least squares regression was used to examine these relationships. Holding all else constant, we found that perceived COVID-19 health threat and the belief that Black Americans face racial discrimination in medical settings were both positively and significantly associated with higher levels of psychological distress. We also found a significant perceived COVID-19 health threat by belief about discrimination in medical settings interaction in the full model. Future studies should assess how these relationships vary across age groups and over time.

The microsporidian spore invasion tube. II. Role of calcium in the activation of invasion tube discharge.

A swelling response by the polaroplast organelle initiated microsporidian invasion tube extrusions by Glugea hertwigi spores. The tumescence was induced by the displacement of internal calcium. Sodium citrate, phosphate, and the calcium ionophore A23187 were effective in initiating polaroplast swelling and spore discharge; however, the addition of external CaCl2 switched the expanded polaroplasts to a contracted state and blocked spore discharge. Unlike CaCl2, equivalent concentrations of KCl, NaCl, MgCl2, and BaCl2 did not induced polaroplast contraction, and spore discharge was not blocked. 45CaCl2 readily incorporated into spores with expanded polaroplasts; however, little calcium uptake was apparent in spores with contracted polaroplasts. Metallochromic arsenazo III yielded a color spectrum characteristic of the dye-Ca++ complex in the polaroplast region; furthermore, a membrane association with calcium was indicated by strong chlorotetracycline fluorescence within the polaroplast; this fluorescence was extinguished by pretreating spores with ionophore A23187. An association of the membrane with calcium was also indicated by a potassium ferrocyanide-osmium tetroxide technique. All evidence indicates that an internal calcium displacement is an important initial step in the swelling response of the polaroplast organelle.

Between (Racial) Groups and a Hard Place: An Exploration of Social Science Approaches to Race and Genetics, 2000-2014.

As the social sciences expand their involvement in genetic and genomic research, more information is needed to understand how theoretical concepts are applied to genetic data found in social surveys. Given the layers of complexity of studying race in relation to genetics and genomics, it is important to identify the varying approaches used to discuss and operationalize race and identity by social scientists. The present study explores how social scientists have used race, ethnicity, and ancestry in studies published in four social science journals from 2000 to 2014. We identify not only how race, ethnicity, and ancestry are classified and conceptualized in this growing area of research, but also how these concepts are incorporated into the methodology and presentation of results, all of which structure the discussion of race, identity, and inequality. This research indicates the slippage between concepts, classifications, and their use by social scientists in their genetics-related research. The current study can assist social scientists with clarifying their use and interpretations of race and ethnicity with the incorporation of genetic data, while limiting possible misinterpretations of the complexities of the connection between genetics and the social world.

Nicotine patch therapy in smoking cessation reduces the extent of exercise-induced myocardial ischemia.

OBJECTIVES: We sought to determine the effects of nicotine patch therapy, when used to promote smoking cessation, on myocardial ischemia in patients with coronary artery disease. BACKGROUND: Nicotine patches substantially increase quit rates among cigarette smokers, but their safety in patients with myocardial ischemia who are attempting to quit smoking is unknown. METHODS: This is a prospective study using exercise thallium-201 single-photon emission computed tomography (SPECT) to assess serial changes in the total and ischemic myocardial perfusion defect size at baseline while patients were smoking and during treatment with 14- and 21-mg nicotine patches. Entry criteria required that patients 1) smoked > or = 1 pack of cigarettes per day; 2) had known coronary artery disease; and 3) had myocardial ischemia (i.e., > or = 5% reversible perfusion defect) on SPECT. All patients performed symptom-limited treadmill exercise, and the baseline SPECT study served as its own control. We interpreted and computer quantified the SPECT images with no knowledge of the testing sequence. RESULTS: Thirty-six of the 40 enrolled patients had exercise SPECT at baseline and during treatment with at least 14-mg nicotine patches. These patients had an initial perfusion defect size of 17.5 +/- 10.6% while smoking an average of 31 +/- 11 cigarettes per day for 40 +/- 12 years. A significant reduction in the total perfusion defect size (p < 0.001) was observed from baseline (17.5 +/- 10.6%) to treatment with 14-mg (12.6 +/- 10.1%) and 21-mg (11.8 +/- 9.9%) nicotine patches. This reduction occurred despite an increase in treadmill exercise duration (p < 0.05) and higher serum nicotine levels (p < 0.001). There was a significant correlation between the reduction in defect size and exhaled carbon monoxide levels (p < 0.001) because patients reduced their smoking by approximately 74% during the trial. CONCLUSIONS: Nicotine patches, when used to promote smoking cessation, significantly reduce the extent of exercise-induced myocardial ischemia as assessed by exercise thallium-201 SPECT.

Institutional origins of health care-associated infection knowledge: lessons from an analysis of articles about methicillin-resistant Staphylococcus aureus published in leading biomedical journals from 1960-2009.

BACKGROUND: Biomedical research journals are important because peer reviewed research is viewed as more legitimate and trustworthy than non-peer reviewed work. Therefore, it is important to know how knowledge transmitted through academic biomedical journals is produced. This article asks if some organizations are more likely to produce research than others and if organizational setting is linked with an article's impact, as measured by citation counts. METHODS: Using research on methicillin-resistant Staphylococcus aureus (MRSA) as a case study, we examined the role that hospitals, universities, public health agencies, and other organizations have in shaping an emerging research area. We collected public data on the organizational affiliations of researchers who authored 1,721 articles in general interest and selected specialty journals. RESULTS: MRSA research appears to have evolved in stages that require the participation of different types of organizations. Additionally, our analyses indicate that an author's organizational affiliation predicts citation counts, even when controlling for other factors. CONCLUSION: Organizations vary greatly in their ability to produce research, and this should be taken into account by those who manage or award funds to research organizations.

3 beta-hydroxysteroid dehydrogenase/isomerase in the fetal zone and neocortex of the human fetal adrenal gland.

The fetal zone of the human fetal adrenal (HFA) gland is established to have decreased 3 beta-hydroxysteroid dehydrogenase/delta 4-5 isomerase (3 beta HSD) activity compared to the neocortex or definitive zone. 3 beta HSD activity, however, can be induced in primary cell culture through treatment with ACTH. Therefore, the HFA with two distinct steroidogenic zones with differences in 3 beta HSD activity as well as the capacity to increase 3 beta HSD activity in response to ACTH provides an excellent model to study the regulation of this enzyme. The presence of 3 beta HSD in the fetal and neocortex zones of the HFA was examined using a polyclonal antibody raised against purified human placental microsomal 3 beta HSD. After homogenates of the fetal and neocortical zones of the HFA were electrophoresed on a sodium dodecyl sulfate-polyacrylamide gel and immunoblotted, the presence of the 3 beta HSD protein with a molecular size of 45 kDa could be demonstrated only in the neocortical zone. ACTH treatment (greater than 2 days) of fetal and neocortical zone explant cultures produced increases in cortisol secretion associated with the respective levels of immunodetectable 3 beta HSD protein. Cortisol and dehydroepiandrosterone sulfate were the respective principal steroid products of neocortical and fetal zone explants. After ACTH treatment, immunodetectable 3 beta HSD was induced to a greater magnitude in the neocortex. These findings provide evidence that the lack of 3 beta HSD activity in the fetal zone, previously considered to be the result of the presence of an endogenous inhibitor, is due to an absence of the protein in this portion of the gland. The lack or minimal expression of 3 beta HSD in the fetal zone of HFA may be due to the action (or lack thereof) of a tissue-specific factor regulating the synthesis of 3 beta HSD.

Transforming growth factor-beta inhibits steroid 17 alpha-hydroxylase cytochrome P-450 expression in ovine adrenocortical cells.

The maintenance of optimal steroidogenesis in adrenocortical cells primarily depends on the chronic action of ACTH to promote the synthesis of the various steroid-metabolizing cytochrome P-450 enzymes. In the steroidogenic pathway, 17 alpha-hydroxylase cytochrome P-450 (P-450(17) alpha) is a key enzyme controlling the formation of cortisol and androgens. Recently, we demonstrated that transforming growth factor-beta (TGF beta) is a potent inhibitor of steroid production in ovine adrenocortical cells. In the present study we used a polyclonal antibody to P450(17) alpha to determine adrenal cell P-450(17) alpha enzyme content by Western analysis. In addition, we used a cDNA probe encoding for bovine P-450(17) alpha mRNA to determine levels of P-450(17) alpha mRNA in sheep ovarian adrenocortical cells in primary culture. When cells were cultured in a serum-free medium in the presence of ACTH for 48 h, P-450(17) alpha activity, enzyme content, and mRNA levels for P-450(17) alpha increased by 3- to more than 10-fold. TGF beta decreased the basal level and completely blocked the stimulatory action of ACTH on P-450(17) alpha enzyme activity. The effects of TGF beta on P-450(17) alpha enzyme content and mRNA levels were manifested in a dose-dependent manner, with maximal inhibition observed using 1 ng/ml TGF beta. Importantly, the inhibitory effects of TGF beta on P-450(17) alpha were not overcome by (Bu)2cAMP. These findings indicate that TGF beta is a potent negative regulator of P-450, and the inhibitory action appears to be at the level of P-450(17) alpha gene expression. The ability of TGF beta to suppress the positive stimulatory action of ACTH suggests that TGF beta could play a role in determining the pathway of steroidogenesis and, thereby, the specific steroids secreted by adrenocortical cells.

The effects of growth factors and phorbol esters on steroid biosynthesis in isolated human theca interna and granulosa-lutein cells in long term culture.

In this report we examined the effects of growth factors and phorbol esters on steroid hydroxylase activity in cultured human thecal and granulosa-lutein cells. Treatment of thecal cells with epidermal growth factor (EGF), fibroblast growth factor (FGF), transforming growth factor-beta (TGF beta), and tetradecanoyl phorbol acetate (TPA) resulted in the inhibition of forskolin- and dibutyryl cAMP-stimulated 17 alpha-hydroxylase activity and 17 alpha-hydroxyprogesterone and dehydroepiandrosterone production. In contrast, cAMP-stimulated 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) activity was enhanced by FGF and TGF beta, and treatment with EGF enhanced cAMP-stimulated progesterone production. cAMP stimulated 3 beta HSD activity was unaffected by TPA (10 nmol/L) treatment, yet TPA inhibited cAMP-stimulated progesterone production. Basal 3 beta HSD activity and progesterone production were inhibited by TPA. In contrast to the inhibitory actions of EGF, FGF, and TGF beta on 17 alpha-hydroxylase expression, insulin and insulin-like growth factor-I enhanced forskolin-stimulated 17 alpha-hydroxylase activity. In granulosa-lutein cells, forskolin-stimulated aromatase activity was suppressed by EGF, FGF, and TPA. TGF beta had no effect on forskolin-stimulated aromatase activity. EGF, FGF, and TGF beta did not affect forskolin-stimulated progesterone production, whereas treatment with TPA inhibited cAMP-stimulated progesterone secretion. These data suggest that growth factors may differentially regulate cAMP-dependent processes in human thecal and granulosa cells of the developing follicle.

Massive amounts of immunoreactive endothelin in human seminal fluid.

We found that immunoreactive endothelin (ET) is present in seminal fluid in very large amounts (500-5000 ng/L; quantification based on ET-1 standard). This immunoreactive ET was detected by use of a radioimmunoassay system in which the N-terminal portion of ET-1 and ET-2 (and big ET-1 and big ET-2) are recognized. Thus, the immunoreactive ET in seminal fluid may include the precursors of ET-1 or ET-2 (i.e., big ET) as well as metabolites of ET-1 or ET-2 in which the N-terminal region is intact. The levels of immunoreactive ET in seminal fluid from men with normal semen analyses and that in seminal fluid of vasectomized men were within the same range. Using a different radioimmunoassay system in which the C-terminal portion of ET-1, ET-2, and ET-3 is recognized, we found that the levels of immunoreactive ET were much lower (or undetectable). We speculate that bioactive ET may be produced and act to promote sperm transport in the male reproductive tract; thereafter, bioactive ET may be metabolized by membrane metalloendopeptidase (which is present in male reproductive tissues and semen) to immunoreactive, inactive products. Alternatively, big ET in seminal fluid may be processed in tissues of the female internal genitalia to bioactive ET, which could act to promote sperm transport through the uterine cavity by stimulating myometrial contractions.

Effect of superovulation with human menopausal gonadotropins on growth hormone levels in women.

GH synthesis and secretion are influenced by several factors, including age, body weight, and sex steroid hormones. Endogenous and exogenous estrogens influence the circulating levels of GH. The purpose of the present investigation was to define the relationship between serum GH and estradiol levels during the follicular phase in women with normal ovulatory menstrual cycles compared with that in women undergoing superovulation with human menopausal gonadotropins (hMG) alone or hMG plus GnRH agonists during treatment for infertility. Serum GH and estradiol levels were determined by immunoassay in eight women during the follicular phase of a spontaneous natural cycle (group I). Thirty women underwent ovulation induction with hMG alone (group II), and 30 women received GnRH agonists followed by hMG (group III). During the follicular phase estradiol levels increased gradually in group I and reached a peak estradiol level of 1.19 +/- 0.2 nmol/L (mean +/- SEM). As expected, estradiol levels rose faster and reached higher levels in groups II and III (5.44 +/- 0.62 and 8.73 +/- 0.91 nmol/L, respectively). Whereas serum GH levels increased minimally in group I, reaching a peak level of 2.54 +/- 1.15 nmol/L, serum GH concentrations increased markedly after day 8 in groups II and III, reaching peak levels of 8.70 +/- 1.58 and 7.54 +/- 1.12 nmol/L, respectively (P less than 0.01). Basal to peak GH levels were higher in groups II and III than in group I. In summary, there are modest increases in GH levels during the follicular phase of the normal menstrual cycle, but the levels are markedly increased during superovulation with hMG or hMG plus GnRH agonists, and parallel increases in estradiol levels.

The effect of gonadotropin-releasing hormone agonists on adrenocorticotropin and cortisol secretion in adult premenopausal women.

GnRH agonists are known to suppress LH, FSH, and subsequent ovarian estradiol production by down-regulation of pituitary gonadotropin receptors. Previous investigations have demonstrated that GnRH agonists also suppress GHRH-stimulated GH release in normal men and women and PRL levels in subjects with hyperprolactinemia. Little is known about the effects of GnRH agonists on the hypothalamic-pituitary-adrenal axis. The purpose of the present investigation was to determine the secretion of ACTH and cortisol after an iv infusion of hCRH in control women (n = 11) and in women undergoing treatment with GnRH agonists (n = 10). The plasma and serum levels of ACTH and cortisol increased after infusion of CRH in all women. The basal and CRH-stimulated plasma levels of ACTH and cortisol at each time point were not statistically different between GnRH agonist-treated women and controls. Thus, the chronic use of GnRH agonists is known to suppress the hypothalamic-pituitary-ovarian axis and is associated with GH and PRL suppression as well, but does not apparently alter the hypothalamic-pituitary-adrenal axis.

Oral contraceptive pills, gonadotropin-releasing hormone agonists, or use in combination for treatment of hirsutism: a clinical research center study.

The effectiveness of oral contraceptive pills (OCPs), GnRH agonist (GnRH-a), and a combination of OCPs and GnRH-a in the treatment of hirsute women was compared and the impact of these treatments on hormonal and Ca metabolism was investigated. Thirty-three women were prospectively enrolled and randomized into three treatment groups (11 in each group). The serum levels of LH, estradiol, testosterone, free testosterone, androstenedione, and 17-hydroxyprogesterone declined in all 3 treatment groups, whereas the inclusion of GnRH-a treatment tended to promote a more rapid decrease in these hormone levels. Total cholesterol, low density lipoprotein, and high density lipoprotein levels remained unchanged. The assessment of hirsutism by the Ferriman-Gallwey score revealed a similar 25% reduction in score by all three treatment groups by 6 months. In addition, no difference was detected between groups with respect to hair diameters and the vellus index. Clinical assessment of hirsutism at 3 months by the patients revealed that the GnRH-a and the OCPs-plus-GnRH-a groups had better responses than the group on OCPs alone, but by 6 months all three groups were similar. The symptoms of hot flashes and vaginal dryness were greatest in subjects treated with GnRH-a alone. Serum Ca, phosphorus, alkaline phosphatase, osteocalcin, and 2-h fasting and 24-h urinary Ca excretion levels all increased significantly in subjects treated with the GnRH-a alone, whereas a decrement or no changes occurred for these measurement in the other two groups. The estimated Ca balance was unchanged in the OCPs and the OCPs-plus-GnRH-a groups but declined by 90 mg/day from baseline in the GnRH-a-treated women (p < or = 0.001). Bone density significantly decreased in the lumber spine in women treated with GnRH-a alone, with a less marked decline in the femoral neck. In contrast, women receiving OCPs plus GnRH had increased bone density in the lumbar spine. It is concluded that: 1) clinical measures of hirsutism are not different after 6 months of treatment with OCPs alone, GnRH-a alone, or a combination of the two; 2) the decline in gonadotropins and steroid hormones and improvement in clinical response were more rapid and pronounced when GnRH-a treatment was added to OCP administration; and 3) the negative impact of GnRH-a alone on Ca balance and bone loss limits its usefulness as a single agent for long-term therapy of hirsutism.

PIP: The effectiveness of oral contraceptive pills (OCPs), GnRH agonist (GnRH-a), and a combination of OCPs and GnRH-a in the treatment of hirsute women (modified Ferriman-Gallwey score 10), 20-39 years old, was compared and the impact of these treatments on hormonal and Ca metabolism was investigated. 33 women were prospectively enrolled and randomized into 3 treatment groups (11 in each group): 1) OCPs [35 mcg ethinyl estradiol plus 1 mg norethindrone administered cyclically]; 2) GnRH-a, 3.75 mg im, every 4 weeks for 24 weeks; or 3) a combination of both OCPs and GnRH-a at the above doses taken concurrently. All medications were administered for 6 months. The serum levels of LH, estradiol, testosterone, free testosterone, androstenedione, and 17-hydroxyprogesterone declined in all 3 treatment groups. The assessment of hirsutism by the Ferriman-Gallwey score revealed a similar 25% reduction in score by all 3 treatment groups by 6 months. The symptoms of hot flashes and vaginal dryness were greatest in subjects treated with GnRH-a alone. Serum Ca, phosphorus, alkaline phosphatase, osteocalcin, and 2-h fasting and 24-h urinary Ca excretion levels all increased significantly in subjects treated with the GnRH-a alone. In the OCP groups there was significant decline in serum Ca from baseline to 24 weeks (p or = 0.01). There was significant urinary loss of Ca in the GnRH-a group with respect to 24-hour excretion (p or = 0.001). The estimated Ca balance was unchanged in the OCPs and the OCPs-plus-GnRH-a groups, however, it declined by 90 mg/day from baseline in the GnRH-a-treated women from 111 +or- 43 to 21 +or- 58 mg/day (p or = 0.001). Bone density significantly decreased (by 2.7%) in the lumber spine in women treated with GnRH-a alone (p or = 0.02), with a less marked decline in the femoral neck. The negative impact of GnRH-a alone on Ca balance and bone loss limits its usefulness as a single agent for long-term therapy of hirsutism.

Regulation of biologically active dimeric inhibin A and B from infancy to adulthood in the male.

Inhibins are glycoprotein members of the transforming growth factor-beta family that have been implicated in the control of spermatogenesis by exerting a negative feedback on FSH secretion. In addition, locally produced inhibins may play a role in paracrine regulation of testicular function. Immunoassays were used to measure the two biologically active dimeric forms of inhibin (inhibin A and B) in serum, seminal plasma, and urine. To better define their actions, inhibins were measured in the male during infancy, sexual maturation, and senescence. Inhibin B but not A was measurable in the serum of male newborns, infants, children, and adults. In adult males, measurable levels of inhibin B were detected in the seminal plasma but not the urine. The circulating levels of inhibin B increased shortly after birth and peaked at 4-12 months of age (210 +/- 31 pg/mL). The concentration measured in the serum then decreased to a low of 81 +/- 12 pg/mL of inhibin B from 3-9 yr of age followed by a gradual increase beginning with the onset of puberty and reaching another peak of 167 +/- 20 pg/mL in males who were 20-30 yr of age. Inhibin B levels then gradually declined with increasing age up through 90 yr of age. Serum levels of gonadotropins and total testosterone production were also measured in these same males. There was a brief increase in the gonadotropins (FSH and LH) during the few months of postnatal development, followed by a decrease to basal levels until the onset of puberty at 10-14 yr of age. Testosterone was also increased in the serum of infants from day 1 through 12 months of age, which decreased in young children but increased again following the elevation of gonadotropins during puberty. In adults aged 20-90 yr, serum levels of inhibin B were inversely proportional to levels of FSH but not LH or testosterone. In males in which a semen analysis was performed, those males with normal semen analysis had a significantly higher inhibin B levels, sperm production, and lower FSH levels than males with either oligospermia or nonobstructive azoospermia. The levels of Inhibin B found in circulation were a good marker for testicular function and could be useful in the diagnosis of patients with semen abnormalities or a complete absence of spermatogenesis. Because this glycoprotein is secreted in high amounts in the prepubertal testis up to 3 yr of age, inhibin B could potentially be used as a marker in the diagnosis of cryptorchidism and precocious puberty.

Proliferating human granulosa-lutein cells in long term monolayer culture: expression of aromatase, cholesterol side-chain cleavage, and 3 beta-hydroxysteroid dehydrogenase.

The development of long term culture conditions with which to study the regulation of expression of aromatase, cholesterol side-chain cleavage enzyme, and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD) in human granulosa-lutein cells is described in this report. Conditions have been established for the dispersal, growth, freezing, and storage of functional human granulosa cells isolated from preovulatory follicles of women undergoing laparoscopy for gamete intrafallopian tube transfer and in vitro fertilization procedures. Optimal growth conditions for human granulosa-lutein cells were determined by plating cells at a low density and testing the capacity of a variety of culture conditions to support growth. A combination of fetal bovine serum (FBS), horse serum, and the serum substitute UltroSer G was found to increase cell number to maximal levels, 8- to 10-fold higher than with sera alone. Human granulosa-lutein cells grown under these conditions had a doubling rate of 36-40 h and were morphologically distinct from human theca interna cells grown under similar conditions. Human granulosa-lutein cells treated with forskolin retracted and rounded up, whereas cultures of human ovarian theca interna cells or human fibroblasts treated similarly did not retract. Human granulosa-lutein cells were grown for successive passages and transferred to serum-free medium containing forskolin, LH, hCG, or cholera toxin. Addition of these agents resulted in a time- and dose-dependent increase in aromatase activity and progesterone secretion. In these studies FSH treatment was found not to increase aromatase activity. In a study of the time course of 3 beta HSD activity in the absence of forskolin under serum-free conditions, it was found that 3 beta HSD activity increased 3-fold during the 72-h treatment period. Forskolin-stimulated 3 beta HSD activity also increased in a time-dependent manner, with levels in treated cells 3-fold higher than those in control cells. Northern analysis performed on total RNA obtained from forskolin- or hCG-stimulated granulosa-lutein cells confirmed that the increase in aromatase activity was associated with a corresponding increase in levels of mRNA specific for aromatase cytochrome P-450. Levels of mRNA encoding cholesterol side-chain cleavage cytochrome P-450 were similarly increased in cells treated with forskolin compared with unstimulated values at each of the time points investigated. Under serum-free conditions in the absence of stimulation, the 3.4-kilobase band of aromatase cytochrome P-450 mRNA was detectable.(ABSTRACT TRUNCATED AT 400 WORDS)

Transformation of human granulosa cells with the E6 and E7 regions of human papillomavirus.

Ovarian granulosa cells are the primary site of estrogen and progesterone synthesis and play an essential role in the maturation of the developing ovum. Freshly isolated granulosa cells are often used to study the regulation of steroid and protein biosynthesis, but the small number of cells available for these cultures has proven inadequate for many detailed gene regulatory studies. The goal of this study was to develop human granulosa (HG) cell lines that maintain differentiated function. The E6 and E7 open reading frames of high risk strains of human papillomavirus have been used to produce immortalized cell lines. Primary cultures of human luteinized granulosa cells were infected with defective retroviruses containing the E6 and E7 regions of human papillomavirus 16 and with the neomycin phosphotransferase gene to confer G418 resistance. Three of eight clones that were isolated after selection in medium containing G418 were found to produce progesterone following treatment with forskolin or dibutyryl cAMP for 48 h. Forskolin caused these cells to retract in the characteristic rounding response, as described in primary HG cultures. One clone, HGL5, was used for a detailed characterization of differentiated function. HGL5 cells retained the ability to increase progesterone production and convert exogenously added androstenedione to estradiol in response to agonists of the protein kinase-A pathway (forskolin and dibutyryl cAMP), but were not responsive to FSH or LH treatment. A key enzyme in the production of estradiol, cytochrome P450 aromatase, has proven difficult to maintain in long term cultures of granulosa cells. For that reason, we examined the expression of aromatase in the transformed HGL5 clone by monitoring mRNA levels. Aromatase mRNA increased by 4- to 5-fold after forskolin treatment, as determined by Northern analysis. This human granulosa cell culture line maintains many of the functions of normal cells and should provide an important model to study the molecular events controlling granulosa cell differentiation and function.

Inhibin-B: a likely candidate for the physiologically important form of inhibin in men.

Inhibin is a glycoprotein hormone that is defined on the basis of inhibition of pituitary FSH production, However, previous data have not shown any correlation between RIA measurements of inhibin and FSH in men. New enzyme-linked immunosorbent assays, specific for inhibin A, inhibin B, and inhibin pro-alphaC-related immunoreactivity, were applied to the measurement of inhibin in 32 healthy men. Further measurements of inhibin B and pro-alphaC-RI were carried out on groups of men exhibiting a wide range of FSH concentrations, including semen donors, infertile men, and men with elevated FSH concentrations. Inhibin A was undetectable (<2 pg/mL) in all men studied. The healthy men studied all had measurable concentrations of inhibin B (135.6 pg/mL; confidence interval, 108.4-169.4) and pro-alphaC-RI (426.3 pg/mL; confidence interval, 378.4-480.2). A close negative correlation was found between the inhibin B and FSH concentrations in the semen donors (r = -0.69; P < 0.001), the infertile men (r = -0.81; P < 0.001), and the men with elevated FSH concentrations (r = -0.54; P < 0.01), but not in a group of healthy volunteers (r = -0.08; P = NS). No correlation was observed between concentrations of pro-alphaC-RI and FSH in any of the groups studied. These results strongly suggest that the physiologically important form of inhibin in men is inhibin B, which has a critical effect on FSH release. Inhibin B may offer a clinically useful serum marker of testicular function.

An evaluation of the effect of gonadotropin-releasing hormone analogs and medroxyprogesterone acetate on uterine leiomyomata volume by magnetic resonance imaging: a prospective, randomized, double blind, placebo-controlled, crossover trial.

The purpose of this study was to prospectively compare the effectiveness of administering medroxyprogesterone acetate (MPA; 20 mg/day) in either the first (protocol A) or last (protocol B) 12-week period along with a 6-month course of the GnRH analog (GnRH-a; leuprolide acetate; 1 mg/day, sc) on uterine and leiomyomata volumes and hormone (estradiol, LH, and FSH) and serum lipid (total cholesterol, triglycerides, and high and low density lipoprotein) levels. Sixteen women were randomized into protocol A or B, received either MPA or placebo along with GnRH-a, respectively, and were then crossed over at 12 weeks to placebo or MPA, respectively, for the final 12-week interval of GnRH-a therapy. Total, myoma, and nonmyoma uterine volumes were determined by magnetic resonance imaging, and serum studies were performed at the beginning of the study and at 12 and 24 weeks. In both protocols, LH and estradiol levels declined by 80-90% (P < 0.03) and 55-72% (P < 0.02) of the baseline, respectively, at 12 weeks and remained at this level at 24 weeks. There were no significant changes in the other laboratory tests between protocols or longitudinally over time. Total uterine volume decreased to 73% of the baseline at 12 weeks in protocol B (P < 0.04), but did not change in protocol A. After crossover at 12 weeks, the total uterine volume of women in protocol A decreased to 74% of the baseline (P < 0.02) at 24 weeks. Between-protocol comparisons demonstrated a greater decline in total uterine volume in protocol B than A at 12 weeks, but after cross-over, MPA addition was associated with a significant increase in total uterine volume (protocol B) compared to a decrease in protocol A at 24 weeks (P < 0.005). In contrast, although myoma volume declined in both protocols, no significant changes in myoma volume were detected within or between groups over the treatment period. Nonmyoma volume changes in protocols A and B roughly paralleled total uterine volume changes, with MPA coadministration showing a correlation with a reversal in the GnRH-a-associated decrease in nonmyomatous tissue volume.(ABSTRACT TRUNCATED AT 400 WORDS)