The influence of a Vitamin D receptor gene polymorphism on the timing of female reproductive functions in humans

OBJECTIVE

To evaluate the association between a common polymorphism of the Vitamin D receptor gene (VDR) and the timing of female reproductive functions in humans.

METHODS

One thousand fifty-eight consecutive women were included in this cross-sectional study. We analyzed the intron 8 Bsm I restriction fragment length polymorphism (RFLP) of VDR on chromosome 12q using a microarray-based system.

RESULTS

The presence of the VDR polymorphism did not influence the timing of menarche and natural menopause and was not associated with the number of spontaneous abortions, full term pregnancies (FTP) as well as the total number of pregnancies. Of note, women with at least one mutant allele of VDR were at a significantly decreased risk for experiencing surgical menopause (odds ratio [OR] 0.65, 95% confidence interval [CI], 0.46-0.92, P = 0.02). Smoking and a body mass index (BMI) > 25 were associated with an earlier natural menopause and an increased risk for surgical menopause, respectively.

CONCLUSIONS

While no association of a common polymorphism of VDR with the timing of menarche and menopause was ascertained, we found the presence of at least one mutant allele of VDR to be associated with a decreased risk of experiencing surgical menopause, i.e., premenopausal hysterectomy, in a large series of Caucasian women.

Estrogen-metabolizing gene polymorphisms and age at natural menopause in Caucasian women

BACKGROUND

Lifestyle parameters, personal history and genetic factors are thought to affect the timing of natural menopause in humans. Based on their biological function, estrogen-metabolizing gene polymorphisms have been regarded as candidate genes for early menopause.

METHODS

In the present cross-sectional, multi-centre study, we analysed nine single nucleotide polymorphisms of six estrogen-metabolizing genes [three estrogen-synthesizing genes, i.e. 17-beta-hydroxysteroid dehydrogenase type 1 (17-beta HSD), cytochrome P-450 (CYP) 17 and CYP19; and three estrogen-inactivating genes, i.e. catechol-O-methyltransferase (COMT), CYP1A1 and CYP1B1] by sequencing-on-chip-technology in 1360 Caucasian women with natural menopause. Women's lifestyle parameters, reproductive and personal histories were ascertained.

RESULTS

Carriage of at least one mutant allele of the CYP1B1-4 Asn453Ser A--> G polymorphism (P = 0.004) and the number of full-term pregnancies (P < 0.001) were found to be independently associated with age at natural menopause. Women with at least one polymorphic allele of CYP1B1-4 experienced natural menopause earlier than non-carriers of the polymorphism [mean (SD) 48.6 (5.0) versus 49.4 (4.3) years]. Women with no, one, two and three or more full-term pregnancies experienced natural menopause at 48.5 (5.0), 48.8 (4.8), 49.5 (4.2) and 49.6 (4.6) years, respectively.

CONCLUSION

We present the most comprehensive data on estrogen-metabolizing gene polymorphisms and timing of natural menopause to date. The number of full-term pregnancies and the CYP1B1-4 polymorphism are significant predictors of timing of natural menopause in Caucasian women.

A predictive model for endometriosis

BACKGROUND

Aromatase is the key enzyme in the process of estrogen biosynthesis from the precursor androgen. Recently, aromatase has been found to be aberrantly expressed in eutopic endometrium of patients suffering from endometriosis. This finding has prompted speculation about the contribution of this enzyme to the prediction of this disease.

METHODS

We prospectively aimed to evaluate whether endometrial biopsy, prior to laparoscopy in symptomatic women to screen for the presence of aromatase by real-time RT-PCR and immunohistochemistry, combined with select patients' characteristics, is of value to predict endometriosis.

RESULTS

Of 48 consecutive symptomatic and eligible patients, 25 (52.1%) exhibited endometriosis and 23 (47.9%) were disease-free. A multiple logistic regression model revealed that 95.5% of patients whose eutopic endometrium was found to be positive for aromatase mRNA as well as immunohistochemically detected protein and who were additionally suffering from moderate to severe dysmenorrhoea (visual analogue scale score >4/10) exhibited endometriosis at laparoscopy.

CONCLUSIONS

These findings provide direct evidence that screening for eutopic endometrial aromatase in combination with clinical data could be of discriminative value in the prediction of disease.

Recurrent pregnancy failure is associated with a polymorphism in the p53 tumour suppressor gene

BACKGROUND

The p53 tumour suppressor gene is a well-known factor regulating apoptosis in a wide variety of cells and tissues. Alterations in the p53 gene are among the most common genetic changes in human cancers. In addition, recent data provide evidence that p53 plays a critical role in mediating pregnancy by regulating steroid hormone activation. In idiopathic recurrent miscarriages (IRM), causes and associations are much debated as the exact pathophysiological mechanisms are unknown. In this study, we assess whether an established polymorphism in the p53 gene is associated with the occurrence of IRM.

METHODS

Genotyping was performed by PCR-based amplification of the p53 Arg and Pro variants at codon 72 in 175 cases of IRM and 143 controls.

RESULTS

We observed a statistically significant association between carriage of the Pro allele and the occurrence of IRM (P = 0.03, odds ratio 1.49, confidence interval 1.04-2.14). Distribution of genotypes was in Hardy-Weinberg equilibrium.

CONCLUSIONS

Our results indicate an over-representation of the Pro allele of the p53 gene in women with IRM, giving support to the theory that p53 has a potential role during pregnancy.

Effects of an herbal medication containing bee products on menopausal symptoms and cardiovascular risk markers: results of a pilot open-uncontrolled trial

OBJECTIVES

Fifty-five postmenopausal women with menopausal complaints were treated with the food supplement Melbrosia for 3 months. Menopausal symptom evaluation scales and psychological questionnaires were administered, and cardiovascular disease markers in blood were analyzed at the beginning and the end of the trial.

SETTING

The perimenopausal care unit of Second Obstetrics and Gynecology Hospital, Sofia, Bulgaria.

DESIGN

The study was an open, multicenter, uncontrolled, prospective observation study. The subjective symptoms questionnaires administered before Melbrosia treatment and after 3 months of treatment were Kupperman Score, Zerssen Symptom List, Zung Depression Score, and Frankfurt Self-concept Scale (self-assessment test, problem-solving test, self-esteem test, and irritability test). The blood levels of high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides (TG), total cholesterol (TC), vascular cell adhesion molecule-1 (VCAM-1), and C-reactive protein (CRP) levels were measured in a subgroup of patients.

RESULTS

Treatment of postmenopausal women with Melbrosia led to a statistically significant reduction in the Kupperman score, Zerssen's Symptoms List, and Zung Depression Score. The Frankfurt Self-concept Scale revealed significant improvement in problem-solving, no change in self-assessment and self-esteem, and worsening of irritability. Treatment with Melbrosia significantly reduced TC and LDL and significantly elevated HDL and TG. There were nonsignificant changes of serum VCAM-1 and CRP levels in patients treated with Melbrosia.

CONCLUSIONS

The presented data suggest that Melbrosia may offer a potential alternative to hormone therapy for the treatment of menopausal symptoms. However, because of this study's uncontrolled, open- label methodology, no cause-and-effect inferences can be drawn until a larger, longer-term, blinded, placebo-controlled, randomized clinical trial is performed.

Systemic HCG treatment in patients with endometriosis: A new perspective for a painful disease

BACKGROUND

Endometriosis is characterized by the presence of endometrium-like tissue outside the uterus. This condition causes painful periods, chronic pelvic pain, subfertility and a profound reduction in quality of life, especially during women's reproductive years. Currently available medical therapies offer comparatively little therapeutic benefit and are often burdened by considerable side effects. However, since clinical evidence shows that pregnancy leads to alleviation of endometriotic symptoms, we have for the first time examined the effect of human chorionic gonadotrophin (HCG) injections on symptoms such as dysmenorrhea and pelvic pain.

PATIENTS AND METHODS

Thirty-one patients with histologically verified endometriosis refractory to therapy received 1 to 2 intramuscular injections of 1500 to 5000 IU HCG per week for a period of 3-12 months. A QoL questionnaire and the visual analog pain intensity scale (VAS) were used to evaluate quality of life and pain intensity, respectively, before and after three months of treatment.

RESULTS

Three months of HCG therapy led to a highly significant reduction of endometriosis-related pain (p<0.001, Wilcoxon test) and to improvement of disease-related parameters such as sleeplessness (p<0.001), irritability (p<0.001), overall discomfort (p<0.001), depressive moods (p<0.001) and painful defecation (p=0.01). Dyspareunia and dysmenorrhea also clearly improved (both p<0.001), though HCG did not lead to significant reduction of dysuria (p=0.66). Prolonged therapy with HCG for up to 12 months (mean: 4.42 months) did not lead to reduction of the beneficial effect.

CONCLUSIONS

HCG injections lead to significant and clinically relevant reduction in pain intensity and to greatly improved quality of life in women with therapy-refractory endometriosis. The remarkable clinical effect of parenteral HCG in our study will have to be confirmed in additional trials but clearly indicates an extremely promising new perspective in the treatment of endometriosis.

Body mass index, follicle-stimulating hormone and their predictive value in in vitro fertilization

PURPOSE

The objective was to explore whether body mass and day 3 follicle-stimulating hormone have predictive value on odds of pregnancy after in vitro fertilisation. Few studies show that obesity produces a variety of alterations in the reproductive system, and that women with an elevation of day 3 FSH have declining ovarian function.

METHODS

The data of one-hundred-seventy-one women who underwent a standard regime of controlled ovarian hyperstimulation was analyzed with particular reference to variations in body mass and hormone levels.

RESULTS

By raising BMI and FSH (mIU/mL) by one unit, the odds for pregnancy were decreased by the respective factors 0.84 (95% confidence interval 0.73-0.97) and 0.77 (95% confidence interval 0.59-1.00).

CONCLUSIONS

The results demonstrate that for the purpose of raising the odds of pregnancy BMI should be reduced. A low FSH value may cause the same effect. Nontheless, obesity and hormonal function may be independent risk factors for failure in assisted reproduction.

The influence of Nos3 polymorphisms on age at menarche and natural menopause

OBJECTIVE

Deficiency of the gene encoding endothelial nitric oxide synthase, i.e. Nos3, has been reported to be associated with late menarche, reduced ovulation rates, fewer deliveries, and earlier onset of menopause in a mouse model.

METHODS

We assessed the Glu298Asp and the T-786C polymorphisms of Nos3 in 87 consecutive healthy postmenopausal women by pyro- and capillary-sequencing, respectively. Results were correlated with age at menarche and natural menopause, number of miscarriages and live births, as well as body mass index (BMI) and smoking habits.

RESULTS

Allelic frequencies of the Glu298Asp polymorphism of Nos3 were 121 (69.5%) and 53 (30.5%) for the wild-type G allele and the mutant T allele, respectively. Forty-one women (47.1%) were homozygote wild-type (G/G), 39 (44.9%) were heterozygote (G/T), and 7 (8.0%) were homozygote mutant (T/T). Allelic frequencies of the T-786C polymorphism of Nos3 were 105 (60.6%) and 69 (39.4%) for the wild-type T allele and the mutant C allele, respectively. Thirty-three women (38.0%) were homozygote wild-type (T/T), 39 (45.1%) were heterozygote (T/C), and 15 (16.9%) were homozygote mutant (C/C). Presence of at least one mutant allele of the Glu298Asp or the T-786C polymorphisms of Nos3 were not associated with age at menarche, natural menopause, and number of miscarriages and deliveries. BMI above 27 kg/m2 and smoking were associated with earlier onset of natural menopause (47.8 years versus 50.2 years (P = 0.01) and 46.8 years versus 49.8 years (p = 0.02)).

CONCLUSIONS

Our data show that smoking and increased BMI, but not Glu298Asp or the T-786C polymorphisms of Nos3, are associated with an early onset of natural menopause.

DNA microarray–based analysis of single nucleotide polymorphisms may be useful for assessing the risks and benefits of hormone therapy

OBJECTIVE

To determine what percentage of women can be given individualized counseling based on genetic information, as single nucleotide polymorphisms (SNPs) are associated with risks and benefits of estrogen therapy and hormone therapy such as thrombosis, myocardial infarction, breast cancer, and bone protection.

DESIGN

Cross-sectional study.

SETTING

Academic research institution.

PATIENT(S)

A consecutive series of 2,507 perimenopausal and postmenopausal women.

INTERVENTION(S)

Peripheral venous puncture and multiplex polymerase chain reaction on a microarray system.

MAIN OUTCOME MEASURE(S)

Analysis of 22 SNPs of 17 genes: AGTMet235Thr, APOECys112Arg, APOEArg158Cys, COMTVal158Met, CYP17-34T>C, CYP191558C>T, CYP19Arg264Cys, CYP1A16235T>C, CYP1A1Ile462Val, CYP1B1Leu432Val, CYP1B1Asn453Ser, HSD17B1-27A>C, ER-alphaIVS-401T>C, prothrombin20210G>A, factor V Leiden, eNOS-786T>C, eNOSGlu298Asp, MRSer810Leu, MTHFR677C>T, PAI 15G>4G, SRD5A2Val89Leu, and VDRb>B.

RESULT(S)

Among the women in the study, 66% had at least two homozygous mutant SNPs of interest. A thrombophilic disposition was found in 9.9% of women, and 23% of women had at least two SNPs associated with an increased risk of breast cancer (COMT, CYP17, CYP19, CYP1A1, and CYP1B1). The SNPs predisposing women to cardiovascular pathologies (e.g., APOE, AGT, eNOS, and PAI 1) were found in 12.3% of women. Carriage of SNPs predisposing to early postmenopausal bone loss and osteoporosis (ER-alpha and VDR) were found in 26.7% of women.

CONCLUSION(S)

These data suggest that the assessment of SNPs associated with risks and benefits of estrogen/hormone therapy may be a new means to individualize counseling about and prescription of estrogen/hormone therapy in up to 66% of women.

Differential effects of progestins on the brain

Interactions exist between progestins and the gamma-aminobutyric acid (GABA) receptor subtype A where C(21)-steroids function as activators. Other interactions between progesterone and neurotransmitter systems include stimulation of dopamine release in striatal tissue, stimulation of GnRH release from hypothalamic neurons and inhibition of opioid receptor binding and activation. Cyproterone acetate increases dopaminergic responses and binds to opiate receptors independently of its classical effect on the androgen receptor. Progesterone substitution in perimenopausal women promotes length and quality of sleep. This effect seems most prominent for progesterone administered vaginally. Progestins also play a role in the pathogenesis of migraine. Migraine symptoms occur predominantly during the perimenstrual stage. Women who suffer from menstrual migraine triggered by premenstrual progesterone loss often benefit from cyclic progesterone administration. This may be because progesterone and allopregnenolone reduce meningeal release of substance P and inhibit the development of neurogenic oedema. Women whose migraine symptoms subside during pregnancy, however, benefit from intramuscular medroxyprogesterone acetate. Progesterone, generated from pregnenolone by Schwann cells, also enhances myelin synthesis. Myelination of axons is promoted when progesterone is added to cultures of rat dorsal root ganglia. No reliable data exist with respect to the effects of other progestins on demyelinating disease. Progestins promote the growth of meningioma as progesterone receptors predominate in meningioma tissue. Progesterone and synthetic progestins should therefore not be prescribed in these patients.

A common interleukin-6 gene promoter polymorphism influences the clinical characteristics of women with polycystic ovary syndrome

OBJECTIVE

To investigate the association of a common polymorphism of the interleukin-6 gene (IL6) promoter with the occurence and the clinical characteristics of polycystic ovary syndrome (PCOS).

DESIGN

Prospective, case-control study.

SETTING

Academic research institution.

PATIENT(S)

Sixty-two patients with PCOS and 94 healthy controls.

INTERVENTION(S)

Peripheral venous puncture, ultrasonography, oral glucose tolerance test (OGTT), questionnaire.

MAIN OUTCOME MEASURE(S)

Genotype analysis with respect to the common -174 G/C polymorphism of the IL6 gene promoter, analysis of testosterone (T), androstendione, and sex hormone binding globulin serum levels, and evaluation of the OGTT.

RESULT(S)

Allele frequencies among women with PCOS and controls were 62.9% and 64.4%, respectively, for the wild-type G allele, and 37.1% and 35.6%, respectively, for the mutant C allele. We ascertained a significant association between presence of at least one mutant C allele and the clinical characteristics of affected women: these women were more likely to present with a body mass index >27 kg/m(2), elevated total T serum levels, and a pathological OGTT result.

CONCLUSION(S)

A common polymorphism of the IL6 promoter, although not associated with the presence of PCOS, is associated with the clinical characteristics of women affected by this condition.

Endometriosis: a genetic disease

Endometriosis is a multifactorial disease affecting up to 15% of women of reproductive age. This condition is characterized by the presence and growth of endometrial cells outside the uterus. Susceptibility to endometriosis depends on complex interactions of immunologic, hormonal, environmental and genetic factors. Although familial inheritance plays a role, multiple candidate genes appear to be involved. New studies investigating the influence of genetic variants on endometriosis are published with increasing frequency. A number of technologies have emerged to facilitate progress in this field, including subtractive cDNA hybridization to identify secretory endometrial genes, DNA chip technology, differential display polymerase chain reaction, cytogenetics evaluation of endometriotic cells and tissues, and complementary methods in proteomics and informatics. One general approach to uncovering genes pivotal to endometriosis is to search systematically for perturbations in selective candidate genes or chromosomal regions using polymerase chain reaction. We describe here novel association studies on obvious candidates, including genes governing cancer susceptibility, hormone sensitivity or immunology. The assessment of mutations and polymorphisms may allow individualization of therapies as well as primary and secondary prevention strategies for endometriosis, aimed at high-risk populations.

Applications of polymorphisms and pharmacogenomics in obstetrics and gynecology

The number of reports investigating disease susceptibility based on the carriage of low-penetrance, high-frequency polymorphisms has steadily increased over the last years. Evidence based on meta-analyses of individual case-control studies is accumulating, defining specific individual variations in disease susceptibility. For example, genetic variations of the estradiol metabolism have been described as significant contributors to disease susceptibility with variations depending on ethnic background. In the field of obstetrics and gynecology, the genetic contribution of polymorphic markers to a series of disorders has been characterized. These disorders include recurrent pregnancy loss, pre-eclampsia, endometriosis, breast cancer, and hormone replacement therapy (HRT)-related complications such as thrombosis. Among other genetic markers, thrombophilic genetic variants, such as the Factor V Leiden and prothrombin G20210A polymorphisms, as well as genetic variants of cytochrome P450 (CYP) enzymes, for example, CYP19 and CYP1B1, have been established as genetic risk markers and disease modifiers of recurrent and sporadic pregnancy loss and HRT-independent and -dependent breast cancer, respectively. In addition, meta-analyses of data in the literature established the TGFBR1*6A, GSTP I105V, and TP53 R72P polymorphisms, as well as the GSTM1 gene deletion as low-penetrance genetic risk factors of sporadic breast cancer. With respect to genetic modulation of therapeutic effects, beneficial effects of estrogen replacement therapy and HRT are modulated by the carriage of single nucleotide polymorphisms, for example, osteoprotection and blood lipid changes by the estrogen receptor-alpha (ER-a) PvuII polymorphism. Polymorphisms of the catechol-O-methyltransferase (COMT), ER-alpha, IL-1 receptor antagonist, and Factor V genes have been demonstrated to modulate the timing of natural menopause. Lastly, a strong genetic contribution of polymorphisms to the development and the clinical course of endometriosis has been established with data pointing to polymorphisms of the COMT, GST, NAT-2, and ER-alpha genes as susceptibility markers. In summary, the available evidence points to a number of polymorphisms of a wide variety of genes as strong hereditary determinants of the susceptibility to benign and malignant gynecologic and obstetric conditions.

Expression of estrogen receptors in human corpus cavernosum and male urethra

Estrogen, largely produced in testis and adrenal gland, may play important roles in male reproduction. Most of the effects of estrogens are mediated by binding of estrogen to one or both of the two estrogen receptor (ER) subtypes alpha and beta. Recently, they have been described in testis, prostate, and efferent ducts, mostly in rodents. The goal of this study was to prove the evidence of ERs in human corpus cavernosum and male urethra, exploring the protein expression of these receptors by immunohistochemistry. Corpus cavernosum and corpus spongiosum smooth muscle was immunoreactive for the androgen receptor (AR), ER alpha, and strongly for ER beta. Endothelial cells were negative for AR, sporadically positive for ER alpha, and positive for ER beta. Urethral epithelium showed strong nuclear expression of AR, predominantly in the basal cell layer, and nuclear expression of ER alpha in the intermediate cells. ER beta was highly expressed in almost all urethral nuclei and, much more weakly, in cytoplasm. Progesterone receptor (PGR) was negative in all cases and all tissues. These results represent the first report that ER alpha and particularly ER beta are regularly expressed in human penile tissue.

Anatomy of the estrogen response element

Estrogens exert their regulatory potential on gene expression through different nuclear and non-nuclear mechanisms. A direct nuclear approach is the interaction of estrogen with specific target sequences of DNA, estrogen response elements (ERE) or units. EREs can be grouped into perfect and imperfect palindromic sequences with the imperfect sequences differing from the consensus sequence in one or more nucleotides and being less responsive to the activated estrogen-estrogen receptor (ER) complex. Differences in the ERE sequence and the ER subtype involved can substantially alter ER-ERE interaction. In addition, cross-talk between ERs and other nuclear transcription factors profoundly influences gene expression. Here, we focus on the recent advances in the understanding of the structure of EREs and how ERs are recruited to these. Identifying known target genes for estrogen action could help us to understand the potential risks and benefits of the administration of this steroid to humans.

Genetic factors in assisted reproduction

It is still unclear whether the procedures of assisted reproduction increase the risk of congenital malformations. Thus, it remains to be clarified whether an increased risk, if any, of congenital malformations in these children is caused by the procedure of assisted reproduction itself or by the underlying maternal and paternal background. From the genetic point of view, infertility patients seeking assisted reproduction have to be classified as a high-risk group. The prevalence of numerical chromosomal abnormalities is around 10% in these patients, compared with 0.85% in the general population. The prevalence of structural chromosomal abnormalities is around 0.1% in the general population and is increased up to 1% in patients seeking assisted reproduction. In addition, patients with microdeletions of the Y-chromosome or mutations in the cystic fibrosis transmembrane-conductance regulator gene are likely to be encountered at the fertility clinic. Therefore, genetic screening and counselling should be routinely offered to infertility patients. They also need to understand that parental factors can be transferred to offspring that would most likely not have been conceived by natural means.

Absence of microdeletions in the azoospermia-factor region of the Y-chromosome in viennese men seeking assisted reproduction

PURPOSE

The azoospermia-factor region of the Y-chromosome is essential for spermatogenesis in humans. In the literature, a wide range is given for the frequency of microdeletions in this region. The purpose of this study was to evaluate our own population of patients.

METHODS

During a two-year period at Vienna Medical School, all male patients (n = 383) seeking assisted reproduction were screened for microdeletions. Thirty-three men had azoospermia and 154 severe oligozoospermia. Genomic DNA was prepared from peripheral lymphocytes and polymerase chain reaction analysis of the azoospermia-factor region was performed using the Promega kit.

RESULTS

No case tested positive for azoospermia-factor microdeletions. In all cases amplification of 18 non-polymorphic sequence tagged sites was obtained.

CONCLUSIONS

Y-chromosome microdeletions do not seem to be an important factor for male infertility in our patients. This suggests that screening should be restricted to men with azoospermia or severe oligozoospermia only.

Physical characteristics of newborn babies after vaginal delivery: a 25-year study from Vienna

This retrospective analysis evaluated whether the gestational age, mean birth weight, length and shoulder width of vaginally delivered newborns have increased during the last 25 years in Vienna, Austria. Women who have given birth at the University of Vienna Medical School Hospital were divided into four age groups: under 20 years, 20-24 years, 25-29 years, and 30 years of age or over. Patient data collected between 1976 to 2000 were grouped into five periods: 1976-1979, 1980-1984, 1985-1989, 1990-1994, and 1995-2000. A highly significant increase of all four parameters was observed for all age groups between 1976 and 2000. The changes were most marked in the 25-29 year age group.

Differential regulation of proteasome-dependent estrogen receptor alpha and beta turnover in cultured human uterine artery endothelial cells

Estrogen-induced loss of estrogen receptor (ER) alpha expression limits estrogen responsiveness in many target cells. However, whether such a mechanism contributes to changes in vascular endothelial ER alpha and/or ER beta levels is unclear. Using RT-PCR assays, we did not find any regulation of ER alpha or ER beta mRNA expression in human uterine artery endothelial cell (HUAEC) nuclear extracts on stimulation with 17 beta-estradiol for 1 or 2 h. By contrast, Western analysis on HUAEC extracts revealed that 17 beta-estradiol was capable of down-regulating both ER alpha and ER beta protein starting 1 h after treatment, an effect that can be blocked by pretreatment with tamoxifen as well as with the proteasome inhibitor lactacystin. The proteolysis inhibitors insulin, cycloheximide, and puromycin impede ER alpha, but not ER beta, turnover. Ubiquitin, but not its competitive inhibitor methyl-ubiquitin, induces rapid turnover of both ERs in a cell-free system of MCF-7 and HUAEC extracts. We, thus, propose the existence of estrogen-induced ER degradation that serves to control physiological responses in an estrogen target tissue, i.e. human vascular endothelium, by down- regulating ER alpha as well as ER beta through different proteasomal uptake mechanisms.

Combined thrombophilic polymorphisms in women with idiopathic recurrent miscarriage

OBJECTIVE

To identify associations or interrelations between carriage of the methylenetetrahydrofolate reductase (MTHFR) C677T, the MTHFR A1298C, the factor V Leiden G1691A, the factor II prothrombin G20210A, the human platelet antigen (HPA) 1 C12548T, and the apolipoprotein (APO) B R3500Q polymorphisms and idiopathic recurrent miscarriage (IRM).

DESIGN

Prospective case control study.

SETTING

Academic research institution.

PATIENT(S)

One hundred forty-five women with a history of three or more consecutive pregnancy losses before 20 weeks gestation and 101 healthy postmenopausal women with at least two live births and no history of pregnancy loss.

INTERVENTION(S)

Peripheral venous punctures.

MAIN OUTCOME MEASURE(S)

Multiplex polymerase chain reaction was performed to identify the different alleles of six candidate genetic risk factors for IRM (MTHFR C677T, MTHFR A1298C, factor V Leiden G1691A, factor II prothrombin G20210A, HPA 1 C12548T, and the APO B R3500Q).

RESULT(S)

Allele and genotype frequencies of all polymorphisms were not significantly different between the study and the control groups. Also, no significant associations occurred between combinations of polymorphisms and the occurrence of IRM.

CONCLUSION(S)

Our data fall short of showing any significant association between single polymorphisms of the MTHFR, the Factor V Leiden, the Factor II Prothrombin, the HPA 1 and APO B genes or combinations of these polymorphisms and the occurrence of IRM.