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Biomedical subjects

J S Tapanainen

Publications and source records attributed to J S Tapanainen.

At least 19 recordsLinked to original sources
PubMed2006

Endocrine and metabolic effects of rosiglitazone in overweight women with PCOS: a randomized placebo-controlled study.

BACKGROUND: The objective of the study was to assess the therapeutic effects of rosiglitazone in overweight women with polycystic ovary syndrome (PCOS). METHODS: A double-blind, placebo-controlled study was conducted on 30 (BMI > 25 kg/m2, mean age 29.1 +/- 1.2 years) overweight women with PCOS treated with rosiglitazone or placebo for 4 months. Waist-to-hip ratios (WHRs), serum concentrations of sex hormones and binding proteins, blood glucose, serum insulin and serum C-peptide during a 75-g oral glucose tolerance test (OGTT), first-phase insulin secretion as determined by an intravenous glucose tolerance test (IVGTT), M values (expressing insulin sensitivity using a euglycaemic clamp) and calorimetric data were assessed at 0 and 4 months of treatment. RESULTS: Rosiglitazone improved menstrual cyclicity, increased serum sex hormone-binding globulin (SHBG) levels and decreased serum levels of androstenedione, 17-hydroxyprogesterone (17-OHP), dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEA-S). Glucose tolerance [expressed as AUC(glucose) during the OGTT] improved (P = 0.002) and peripheral insulin response (expressed as AUC(insulin)) decreased (P = 0.004) in the rosiglitazone group (ROSI group). M value improved in the ROSI group from 33.4 +/- 3.27 to 40.0 +/- 5.51 micromol/kg min (P = 0.04). CONCLUSION: Rosiglitazone, by improving menstrual cyclicity, hyperandrogenism, insulin resistance and hyperinsulinaemia, represents an alternative treatment for overweight anovulatory women with PCOS and no pregnancy desire.

17-alpha-Hydroxyprogesterone↗
PubMed2005

Association between sequence variations in genes encoding human zona pellucida glycoproteins and fertilization failure in IVF.

BACKGROUND: The zona pellucida (ZP) has multiple roles in reproductive processes, including oocyte maturation, fertilization and implantation. We used, for the first time, a genetic approach to study whether human ZP genes possess structural alterations in women with unsuccessful IVF trials. In theory, this may result in gradual reduction of sperm-zona interaction and eventually in total fertilization failure (TFF). METHODS: Eighteen infertile women (TFFs) whose IVF did not result in any fertilized oocytes, whereas fertilization by ICSI was successful, were screened for mutations in ZP genes by means of conformation-sensitive gel electrophoresis. Twenty-three fertilizers in IVF (FIVFs) and 68 women with proven fertility (WPFs) constituted the two control groups. RESULTS: Altogether, 20 sequence variations were found in the ZP genes. Two variations in ZP3, one in the regulatory region (c. 1-87 T --> G) and one in exon 6 [c. 894 G --> A (p. K298)] existed more frequently in TFFs than in FIVF and WPF groups (P-values 0.027 and 0.008, respectively). CONCLUSIONS: Our study on ZP genes of infertile women revealed a high degree of sequence variations. This may reflect gradual reduction of fertility among TFFs, but the putative roles and influences of single variations can only be hypothesized.

Adult↗
PubMed2005

Low-dose aspirin does not improve ovarian responsiveness or pregnancy rate in IVF and ICSI patients: a randomized, placebo-controlled double-blind study.

BACKGROUND: Poor ovarian and endometrial responses to gonadotrophin stimulation in assisted reproduction techniques lead to decreased pregnancy rates. The aim of the present study was to test the hypothesis that low-dose aspirin started prior to controlled ovarian stimulation improves ovarian responsiveness, pregnancy rate (PR) and pregnancy outcome. METHODS: A total of 374 women who were to undergo IVF/ICSI were randomized to receive 100 mg of aspirin (n=186) or placebo (n=188) daily. Treatment was started on the first day of controlled ovarian stimulation. It was continued until menstruation or a negative pregnancy test. Pregnant women continued the medication until delivery. The main outcome measures were the number of oocytes, number and quality of embryos, the clinical PR and pregnancy outcome. RESULTS: The mean (+/-SD) number of oocytes (12.0+/-7.0 versus 12.7+/-7.2), the total mean number of embryos (5.82+/-4.35 versus 5.99+/-4.66), the mean number of top quality embryos (0.99+/-1.39 versus 1.18+/-1.51) and the number of embryos transferred (1.64+/-0.64 versus 1.63+/-0.71) did not differ in the aspirin and placebo groups. Between the aspirin and placebo group, there was no statistically significant difference in clinical PR per embryo transfer (25.3%, n=44 out of 174 versus 27.4%, n=48 out of 175) or clinical PR per cycle initiated (23.7% versus 25.5%). Birth rate per embryo transfer did not differ significantly between the aspirin (18.4%) and placebo (21.1%) groups. The incidence of poor responders [12 (6.5%) versus 13 (6.9%)] was similar in both groups. CONCLUSIONS: The present results indicate that low-dose aspirin treatment does not have any beneficial effect on ovarian responsiveness, PR and pregnancy outcome in unselected women undergoing IVF/ICSI.

Adult↗
PubMed2005

Effects of metformin and ethinyl estradiol-cyproterone acetate on lipid levels in obese and non-obese women with polycystic ovary syndrome.

OBJECTIVE: Women with polycystic ovary syndrome (PCOS) exhibit risk factors for cardiovascular diseases such as abdominal obesity, insulin resistance and dyslipidemia. Insulin sensitizers, especially metformin, have been shown to improve these metabolic disturbances, but there are only a few studies on their effects on serum lipids in polycystic ovary syndrome. METHODS: Thirty-five women with PCOS (18 obese and 17 non-obese) were randomized to 6-month treatments with metformin or ethinyl estradiol-cyproterone acetate oral contraceptive pills. RESULTS: In the whole-study population (non-obese and obese women) serum levels of high-density lipoprotein cholesterol increased from 1.4+/-0.2 to 1.6+/-0.1 mmol/l (means +/-S.E. throughout) at 3 and 6 months (P < 0.001), the total cholesterol:high-density lipoprotein cholesterol ratio decreased significantly from 3.8+/-0.3 to 3.3+/-0.2 at 6 months (P < 0.001) and a similar trend was observed in serum triglyceride levels during metformin treatment. In the oral contraceptive group, serum levels of total cholesterol increased from 4.9+/-0.3 to 5.4+/-0.3 mmol/l (P < 0.05), high-density lipoprotein cholesterol increased from 1.2+/-0.1 to 1.5+/-0.1 mmol/l (P < 0.001), the total cholesterol:high-density lipoprotein cholesterol ratio decreased from 4.6+/-0.4 to 3.7+/-0.2 (P < 0.001) and triglycerides increased from 1.3+/-0.1 to 1.9+/-0.2 mmol/l at 6 months of treatment (P < 0.001). Serum low-density lipoprotein cholesterol levels remained unchanged during both treatments. Milder but similar changes in the subgroups of obese and non-obese women were observed during both treatments. Moreover, in the whole-study population both systolic (P = 0.02) and diastolic (P = 0.05) blood pressures decreased over the 6 months of metformin treatment. CONCLUSION: In women with PCOS, metformin treatment had beneficial effects on lipid profile and blood pressure, and therefore it could be useful in the prevention of cardiovascular complications in these women.

Adult↗
PubMed2004

Long-term reproductive endocrine health in young women with epilepsy during puberty.

OBJECTIVE: To evaluate the outcome of epilepsy and later reproductive endocrine health in girls who had epilepsy during puberty, using a population-based controlled study. METHODS: Sixty-nine patients (88%) and 51 control subjects (94%) of previously identified cohorts of 78 girls with epilepsy and 54 healthy control girls participated in this study (initial age 8 to 18.5 years, at follow-up 12.5 to 25.8 years). Thirty-five of the patients were initially taking valproate (VPA), 17 carbamazepine, and 17 oxcarbazepine as monotherapy. Most of the patients (61%) were off medication. All the subjects were examined clinically, the medical and menstrual histories were obtained, ovarian ultrasonography was examined, and serum reproductive hormone concentrations were analyzed. RESULTS: There were no significant differences in laboratory or clinical findings between the patients off medication and the control subjects. Postpubertal patients on medication had higher serum testosterone (1.9 nmol/L, SD 0.7 nmol/L) and androstenedione (18.8 nmol/L, SD 15.2 nmol/L) levels than patients off medication (1.4 nmol/L, SD 0.5 nmol/L, and 9.5 nmol/L, SD 2.6 nmol/L) or control subjects (1.4 nmol/L, SD 0.5 nmol/L, and 10.2 nmol/L, SD 3.2 nmol/L) (all comparisons p < 0.02). All patients still on VPA had elevated serum androstenedione levels. Polycystic ovary syndrome was more common in patients on medication (38%; in 63% on VPA, in 25% on other medication) than in patients off medication (6%) or in controls (11%) (p = 0.005). CONCLUSIONS: Epilepsy during pubertal maturation does not affect reproductive endocrine health in female subjects who discontinue the medication before adulthood. However, an increased prevalence of endocrine disorders is detected if the patients remain on antiepileptic drugs, especially VPA, until adulthood.

Adolescent↗
PubMed2004

Effects of tibolone and cyclic hormone replacement therapy on glucose metabolism in non-diabetic obese postmenopausal women: a randomized study.

OBJECTIVE AND METHODS: To study the effects of hormone replacement therapy on glucose metabolism, 31 obese (body mass index > or =27 kg/m(2)) postmenopausal women were randomized to treatment with tibolone (2.5 mg once daily; TIB; n=16) or to oestradiol valerate (2 mg daily)-dydrogesterone (20 mg daily for 2 weeks every 3 months; ED; n=15) for 12 months. Oral (OGTTs) and intravenous glucose tolerance tests (IVGTTs) and a euglycaemic hyperinsulinaemic clamp were performed before and at 6 and 12 months of treatment. RESULTS: TIB decreased the rates of whole body glucose uptake (WBGU) at 6 (P=0.04) and 12 months (P<0.001), but it did not have a significant effect on glucose tolerance. In OGTTs, serum insulin and C-peptide concentrations 2 h after the oral glucose load were increased (P<0.001 and P=0.05 respectively) at 12 months of treatment with TIB, but no changes in the areas under the curve (AUC) of insulin or C-peptide were observed. Furthermore, TIB did not have a significant effect on insulin secretion, the metabolic clearance rate (MCR) of insulin or hepatic insulin extraction. Treatment with ED did not modify the rates of WBGU, but it increased the MCR of insulin (P=0.017) and hepatic insulin extraction (P<0.001) and tended to decrease the insulin AUC (P=0.07). Moreover, glucose tolerance slightly deteriorated during this treatment (P=0.02). Although early phase insulin secretion evaluated by the serum C-peptide response at 30 min in the OGTT increased (P=0.046), the first-phase insulin response during the IVGTT decreased (P=0.05) during ED treatment. CONCLUSIONS: Despite the impairment in peripheral insulin sensitivity, TIB treatment had a neutral effect on glucose tolerance, possibly due to a compensatory decrease in endogenous glucose production. The increased demand on insulin induced by ED, due to both a stimulatory effect on pancreatic beta cells and increased insulin metabolism, may explain the slightly detrimental effect on glucose tolerance with this treatment.

Area Under Curve↗
PubMed2003

Polymorphism in the peroxisome proliferator-activated receptor-gamma gene in women with polycystic ovary syndrome.

BACKGROUND: In view of the strong evidence implicating peroxisome proliferator-activated receptor-gamma (PPARgamma) in adiposity and insulin resistance a study was carried out to investigate PPARgamma genotype frequencies in women with polycystic ovary syndrome (PCOS) and to elucidate its role in the pathogenesis of the syndrome. METHODS: The study involved 135 women with PCOS and 115 healthy control women who were genotyped for a known functional variant of the PPARgamma gene using single strand conformation polymorphism (SSCP) analysis. RESULTS: A significantly different allele distribution of the Pro12 Ala polymorphism of the PPARgamma gene was observed between the two groups, with the frequency of the variant Ala isoform being significantly reduced in the PCOS group (12.6%) when compared with the control group (19.1%) (P = 0.045), at an odds ratio of 0.609 (95% confidence interval: 0.374-0.991). The genotype distributions of the Pro12 Ala polymorphism in the PCOS and control groups were different with borderline significance (P = 0.051). CONCLUSIONS: Our data support a role for PPARgamma gene polymorphism in the pathogenesis of PCOS, the presence of the Ala isoform being protective against the development of PCOS.

Alleles↗
PubMed2002

Ovarian and adrenal steroid production: regulatory role of LH/HCG.

BACKGROUND: The contribution of the adrenal glands to the total circulating steroid pool in women is not well known. There is evidence that human adrenals express the LH receptor gene and that LH may affect adrenal androgen secretion. METHODS: HCG stimulation tests (a single dose of 5000 IU i.m.) were performed in women at reproductive age (group 1, n = 6, age 21--39 years) before and after treatment with a GnRH agonist for 3 weeks, and in oophorectomized post-menopausal women (group 2, n = 6, 47--59 years) during and after estrogen replacement therapy (ERT). RESULTS: HCG did not stimulate the secretion of cortisol, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulphate (DHEAS) in group 2. In contrast, in group 1, the basal concentrations of serum 17-hydroxyprogesterone (17-OHP), androstenedione, testosterone and estradiol (E(2)) were stimulated significantly (17-OHP 105%, androstenedione 31%, testosterone 20%, E(2) 136%) by HCG, and the treatment with GnRH agonist decreased the responses. The basal serum concentrations of these steroids were significantly lower in oophorectomized women (17-OHP 57%, androstenedione 46%, testosterone 25%), and HCG did not increase these levels. It can be approximated that the ovarian contribution to the circulating levels of 17-OHP, androstenedione and testosterone is 25--30%, and that the adrenals are the primary source of cortisol, DHEA and DHEAS. CONCLUSION: LH/HCG does not have a major role in the regulation of adrenal steroid synthesis in endocrinologically healthy women.

Adrenal Glands↗
PubMed2001

Altered ovarian function and cardiovascular risk factors in valproate-treated women.

PURPOSE: Polycystic ovaries and menstrual disturbances seem to be common among women taking valproate for epilepsy. The purpose of the present study was to assess the frequency of valproate-related metabolic and endocrine disorders in different groups of women with epilepsy. SUBJECTS AND METHODS: Seventy-two women with epilepsy and 52 control subjects from centers in three European countries (Finland, Norway, and the Netherlands) participated in the study. Thirty-seven of the women with epilepsy were taking valproate monotherapy and 35 carbamazepine monotherapy. RESULTS: The frequency of polycystic ovaries or hyperandrogenism, or both, among valproate-treated women with epilepsy was 70% (26 of 37) compared with 19% (10 of 52) among control subjects (P <0.001). They were found in 79% (11 of 14) of obese and 65% (15 of 23) of lean women on valproate, and in 20% (7 of 35) of carbamazepine-treated women. The obese valproate-treated women with polycystic ovaries or hyperandrogenism, or both, had hyperinsulinemia and associated unfavorable changes in serum lipid levels consistent with insulin resistance. CONCLUSIONS: Polycystic ovaries and related hyperandrogenism are frequently encountered in both obese and lean women taking valproate for epilepsy. The use of valproate is associated with risk factors for cardiovascular disease in obese women.

Adult↗
PubMed2001

Ovarian steroidogenic response to human chorionic gonadotrophin in obese women with polycystic ovary syndrome: effect of metformin.

BACKGROUND: The aim of the present study was to investigate the steroidogenic response pattern to HCG in obese women with polycystic ovary syndrome (PCOS) and the possible effects of metformin treatment on it. METHODS: A single injection of human chorionic gonadotrophin (HCG, 5000 IU) was given to 12 obese [body mass index (BMI) > or = 27 kg/m2] women with PCOS and to 27 control women. Blood samples for assays of 17alpha-hydroxyprogesterone (17-OHP), androstenedione, testosterone and oestradiol were collected at baseline and 1, 2 and 4 days after the injection. Responses to HCG were also assessed in the PCOS women after 2-month treatment with metformin (500 mg x 3 daily). RESULTS: Serum 17-OHP and oestradiol concentrations peaked at 24 h in the PCOS women and preceded the maximum testosterone concentration, which was seen at 48 h. In the control women the maximum concentrations of all these steroids were reached 96 h after HCG. After metformin treatment, the basal serum testosterone concentration and the areas under the androstenedione (AUC(A)) and testosterone (AUC(T)) response curves after HCG decreased significantly. CONCLUSIONS: The results demonstrate that obese PCOS women have a male-type steroidogenic response pattern to a single injection of HCG and a higher androgen secretory capacity than control women, which may be explained by the increased thecal cell activity in the polycystic ovary. The slight alleviation of hyperandrogenism brought about by metformin therapy appears to be due to its effect on ovarian steroidogenesis possibly mediated by decreased insulin action.

17-alpha-Hydroxyprogesterone↗
PubMed2001

Metabolic and steroidogenic alterations related to increased frequency of polycystic ovaries in women with a history of gestational diabetes.

The prevalence of polycystic ovaries (PCO) and clinical, endocrine, and metabolic features were investigated in women with previous gestational diabetes (GDM). Thirty-three women with a history of GDM and 48 controls were studied. Glucose and insulin secretion capacity was evaluated by means of the oral glucose tolerance test (OGTT), and insulin action was determined by means of a euglycemic insulin clamp. Compared with control women, women with previous GDM more often had significantly abnormal OGTT, a higher prevalence of PCO (39.4% vs. 16.7%; P = 0.03), higher serum concentrations of cortisol, dehydroepiandrosterone, and dehydroepiandrosterone sulfate and a greater area under the glucose curve. Women with previous GDM showed a lowered early phase insulin response to glucose and impaired insulin sensitivity, which was accounted for mainly by decreased glucose nonoxidation. They also demonstrated a significantly lower fasting serum C peptide/insulin ratio than the controls, indicating that women with previous GDM have impaired hepatic insulin extraction, which tended to be more marked among women with PCO. This may explain why women with PCO and previous GDM were significantly more hyperinsulinemic than women with normal ovaries. In conclusion, our data demonstrate that women with previous GDM often have PCO and abnormal OGTT. They are insulin resistant as a result of lowered glucose nonoxidation and show inappropriately low insulin responses to glucose, reflecting impaired beta-cell function. They also have higher adrenal androgen secretion, which may be associated with abdominal obesity.

Adult↗
PubMed2001

Survival of human ovarian follicles from fetal to adult life: apoptosis, apoptosis-related proteins, and transcription factor GATA-4.

The majority of oocytes present in fetal ovaries are depleted before birth, and only about 400 will ovulate during the normal fertile life span. Studies on animals have shown that apoptosis is the mechanism behind oocyte depletion and follicular atresia. In the present study, we investigated the extent and localization of apoptosis in human fetal (aged 13-40 weeks) and adult ovaries. Furthermore, the expression of apoptosis-regulating proteins, bcl-2 and bax, and the relationship of transcription factor GATA-4 were studied. Apoptosis was found in ovarian follicles throughout fetal and adult life. During fetal development, apoptosis was localized mainly to primary oocytes and was highest between weeks 14-28, decreasing thereafter toward term. Expression of bcl-2 was observed only in the youngest fetal ovaries (weeks 13-14), and bax was present in the ovaries throughout the entire fetal period. In adult ovaries, apoptosis was detected in granulosa cells of secondary and antral follicles, and Bcl-2 and bax were expressed from primary follicles onwards. During fetal ovarian development, GATA-4 messenger RNA and protein were localized to the granulosa cells, with expression being highest in the youngest ovaries and decreasing somewhat toward term. The expression pattern of GATA-4 suggests that it may be involved in the mechanisms protecting granulosa cells from apoptosis from fetal to adult life. The results indicate that depletion of ovarian follicles in the human fetus occurs through intrinsic mechanisms of apoptosis in oocytes, and later in adult life the survival of growing follicles may be primarily determined by granulosa cell apoptosis.

Aging↗
PubMed2001

Gonadal tumors of mice double transgenic for inhibin-alpha promoter-driven simian virus 40 T-antigen and herpes simplex virus thymidine kinase are sensitive to ganciclovir treatment.

We have previously produced transgenic (TG) mice expressing the mouse inhibin alpha-subunit promoter/Simian virus 40 T-antigen (Inhalpha/Tag) fusion gene. The mice develop gonadal somatic cell tumors at the age of 5-7 months; the ovarian tumors originate from granulosa cells, and those of the testes from Leydig cells. In the present study another TG mouse line was produced, expressing under the same inh-alpha promoter the herpes simplex virus thymidine kinase gene (Inhalpha/TK). Crossbreeding of the two TG mouse lines resulted in double TG mice (Inhalpha/TK-Inhalpha/Tag), which also developed gonadal tumors. The single (Inhalpha/Tag) and double TG (Inhalpha/TK-Inhalpha/Tag) mice, both bearing gonadal tumors, were treated at the age of 5.5-6.5 months with ganciclovir (GCV, 150 mg/kg body weight twice daily i.p.) for 14 days, or with aciclovir (ACV, 300-400 mg/kg body weight per day perorally) for 2 months. During GCV treatment, the total gonadal volume including the tumor, decreased in double TG mice by an average of 40% (P<0.05), while in single TG mice, there was a concomitant increase of 60% in gonadal size (P<0.05). GCV was also found to increase apoptosis in gonads of the double TG mice. Peroral treatment with ACV was less effective, it did not reduce significantly the gonadal volume. We also analyzed the in vitro efficacy of ACV and GCV treatments in transiently HSV-TK-transfected KK-1 murine granulosa tumor cells, originating from a single-positive Inhalpha/Tag mouse. GCV proved to be more effective and more specific than ACV in action. These results prove the principle that targeted expression of the HSV-TK gene in gonadal somatic cell tumors is potentially useful for tumor ablation by antiherpes treatment. The findings provide a lead for further development of somatic gene therapy for gonadal tumors.

Acyclovir↗
PubMed2000

Apoptosis and apoptosis-related proteins in human endometrium.

Apoptosis has been shown to be an important regulator of endometrium function. To study the regulation of apoptosis in the endometrium during the normal menstrual cycle, the expression of the apoptosis related proteins Bcl-2 and Bax and their correlation to serum estradiol and progesterone, as well as to a replication-related antigen Ki-67 were analyzed. Nine uterine tissue samples and thirty-nine endometrial biopsy specimens were studied. Apoptosis was studied quantitatively by Southern blot analysis of internucleosomal cleavage of genomic DNA, and qualitatively by using in situ 3'-end labeling of fragmented DNA, and Bcl-2, Bax and Ki-67 were detected and quantified immunohistochemically. Apoptotic cells were mostly detected in the glandular epithelium of late secretory and menstruating endometrium. Immunostaining of Ki-67 was detected predominantly in proliferative endometrium. The expression of Bcl-2 was high in proliferative endometrium and decreased in the secretory phase, being very low or absent in the mid- and late secretory and menstruatory phases. Similarly, Bax expression also decreased, but was still present throughout the secretory phase. In human endometrium, apoptosis occurs predominantly in the late secretory and menstrual phases, and is related to alterations in the expression of Bcl-2 and Bax. A decrease in the Bcl-2/Bax ratio in the early secretory phase precedes DNA fragmentation and may predispose the cells to apoptosis.

Apoptosis↗
PubMed2000

Valproate, hyperandrogenism, and polycystic ovaries: a report of 3 cases.

BACKGROUND: Reproductive endocrine disorders characterized by menstrual disorders, polycystic ovaries, and hyperandrogenism seem to be common among women treated with sodium valproate for epilepsy. OBJECTIVE: To describe the development of valproate-related reproductive endocrine disorders in women with epilepsy. DESIGN: Case report. PATIENTS: Three patients developed a reproductive endocrine disorder during treatment with valproate. It was characterized by hyperandrogenism and polycystic ovaries in all cases, and it was associated with weight gain and menstrual disorders in 2 of the 3 women. RESULTS: Replacing valproate with lamotrigine resulted in a decrease in serum testosterone concentrations in all 3 women. The polycystic changes disappeared from the ovaries in 2 of the women after valproate therapy was discontinued, and the 2 women who had gained weight and developed amenorrhea while being treated with valproate lost weight and resumed menstruating after the change in medication. CONCLUSIONS: The 3 cases presented here illustrate the development of reproductive endocrine disorders after the initiation of valproate therapy in women with epilepsy. The disorders were characterized by hyperandrogenism and polycystic ovaries in all cases, and were associated with weight gain and menstrual disorders in 2 of the 3 women. An evaluation of ovarian structure and function should be considered in women of reproductive age being treated with valproate for epilepsy, especially if they develop menstrual cycle disturbances during treatment.

Adolescent↗
PubMed2000

Insulin sensitivity, insulin secretion, and metabolic and hormonal parameters in healthy women and women with polycystic ovarian syndrome.

To study the contributions of body mass, body fat distribution and family history of type 2 diabetes mellitus to hyperinsulinaemia, insulin secretion and resistance in polycystic ovarian syndrome (PCOS), 17 lean (LC) and 17 obese (OC) healthy control subjects, and 15 lean (LPCOS) and 28 obese (OPCOS) women with PCOS were investigated. Waist:hip ratio (WHR), serum concentrations of sex steroids, glucose and insulin during a 75 g oral glucose tolerance test (OGTT), and insulin and C-peptide early phase secretion, and insulin sensitivity index using a euglycaemic hyperinsulinaemic clamp were assessed. The PCOS subjects had a higher mean WHR than the controls. A trend towards hyperinsulinaemia and impairment of insulin sensitivity (including the rates of both glucose oxidation and non-oxidation) was observed in LPCOS subjects, but only in OPCOS subjects were these changes significant. Early phase insulin secretion but not the early phase C-peptide secretion was increased in PCOS subjects compared to controls, suggesting that peripheral hyperinsulinaemia in PCOS women was mainly due to the observed lowered hepatic insulin extraction and insulin resistance in skeletal muscle. Moreover, the presence of a family history of type 2 diabetes did not affect early phase insulin or C-peptide secretion in the PCOS group. These results confirm and strengthen earlier contentions, that insulin resistance is a characteristic defect in PCOS and is worsened particularly by abdominal obesity.

Adult↗
PubMed2000

Expression of transcription factor GATA-4 during human testicular development and disease.

GATA-4 is a highly conserved transcription factor that plays a critical role in regulating embryonic morphogenesis and cellular differentiation. Given the emerging role of GATA-4 in the development and function of murine gonads, we have now studied its role in human testis. We find that GATA-4 is expressed from early human fetal testicular development to adulthood. This transcription factor is evident in Sertoli cells through fetal and postnatal development. Expression of GATA-4 in Sertoli cells peaks at 19-22 weeks gestation at the time of high circulating fetal FSH. In Leydig cells, GATA-4 is expressed during fetal period and after puberty, coinciding with the periods of active androgen synthesis in the testis; this suggests a link between GATA-4 and steroidogenesis. Also, fetal germ cells and prepubertal spermatogonia express GATA-4, and it is down-regulated in these cells after puberty. As hormonal regulation of GATA-4 in human testis was not possible to study directly, we used testicular samples from patients who had endocrine abnormalities or were hormonally treated. Testicular expression of GATA-4 in hCG-treated cryptorchidism does not differ from that in controls. In androgen resistance, GATA-4 expression in Sertoli and germ cells is weak or totally absent. GATA-4 protein is abundantly present in Sertoli and Leydig cell tumors, suggesting a relationship to tumorigenesis or tumor progression in somatic cell-derived testicular neoplasms.

Adult↗