938 resultados para STEROID SULFATASE
Resumo:
Fetal growth is compromised in animal models with high cortisol availability. In healthy pregnancies, the fetus is protected from high circulating cortisol levels by the placental 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), which is reduced in preeclampsia. We hypothesized increased placental cortisol availability in preeclampsia as missing link to fetal growth restriction and prematurity. Placental tissue was obtained from 39 pregnant women dichotomized normotensive (n = 16) or preeclamptic (n = 23). Placental steroid hormone metabolites were analyzed by gas chromatography-mass spectrometry. Apparent 11beta-HSD2 enzyme activity was calculated as substrate to product ratio. Estradiol and pregnandiol positively correlated with gestational age. Cortisol was virtually absent in 93.8% of controls, yet detectable in 79.3% of preeclamptic samples resulting in an odds ratio (OR) of 0.019 (95% CI 0.002-0.185) for the presence of placental cortisol. Apparent 11beta-HSD2 activity directly correlated with birth weight (R2 = 0.16; p < 0.02) and gestational age (R2 = 0.11; p < 0.04) ensuing a reduced risk of premature delivery (OR 0.12; 95% CI 0.02-0.58). We conclude that normotensive pregnancies are characterized by an almost completely inactivated placental cortisol. In line with our hypothesis, reduced 11beta-HSD2 activity in preeclampsia is unable to abolish placental cortisol, a finding clearly associated with prematurity and low birth weight.
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BACKGROUND: Organotins are highly toxic and widely distributed environmental chemicals. Dibutyltin (DBT) is used as stabilizer in the production of polyvinyl chloride plastics, and it is also the major metabolite formed from tributyltin (TBT) in vivo. DBT is immunotoxic, however, the responsible targets remain to be defined. Due to the importance of glucocorticoids in immune-modulation, we investigated whether DBT could interfere with glucocorticoid receptor (GR) function. METHODOLOGY: We used HEK-293 cells transiently transfected with human GR as well as rat H4IIE hepatoma cells and native human macrophages and human THP-1 macrophages expressing endogenous receptor to study organotin effects on GR function. Docking of organotins was used to investigate the binding mechanism. PRINCIPAL FINDINGS: We found that nanomolar concentrations of DBT, but not other organotins tested, inhibit ligand binding to GR and its transcriptional activity. Docking analysis indicated that DBT inhibits GR activation allosterically by inserting into a site close to the steroid-binding pocket, which disrupts a key interaction between the A-ring of the glucocorticoid and the GR. DBT inhibited glucocorticoid-induced expression of phosphoenolpyruvate carboxykinase (PEPCK) and tyrosine-aminotransferase (TAT) and abolished the glucocorticoid-mediated transrepression of TNF-alpha-induced NF-kappaB activity. Moreover, DBT abrogated the glucocorticoid-mediated suppression of interleukin-6 (IL-6) and TNF-alpha production in lipopolysaccharide (LPS)-stimulated native human macrophages and human THP-1 macrophages. CONCLUSIONS: DBT inhibits ligand binding to GR and subsequent activation of the receptor. By blocking GR activation, DBT may disturb metabolic functions and modulation of the immune system, providing an explanation for some of the toxic effects of this organotin.
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This study surveyed 32 athletes competing at a mixed martial arts (MMA) event held in Butte, Montana. The survey attempted to gather information regarding overall training volume, supplement use, volume change and specific exercises used. The survey return rate was 100 percent (32/32). Twenty-five of 32 athletes supplemented their training with strength training. Overall frequency of strength training ranged from one to six sessions/week, and overall frequency of fighting-specific training sessions/weel ranged from two to 10. Two of the 32 athletes used/had used anabolic-androgenic steroids. Sixteen MMA athletes performed exercises specifically for the neck musculature, and eight use the power clean within their strength-training program. Results suggested that strength and conditioning speciialists should educate the importance of, volume variation and periodization, balanced training, effective exercises, and the side effects of anabolic steroid use.
Resumo:
Regular preoperative application of corticosteroids has been considered as a contraindication to lung transplantation for fear of an increased risk of postoperative morbidity and mortality. Recently, however, we have accepted patients for transplantation in whom treatment with steroid medication could not be terminated preoperatively. Up to February 1991, 27 unilateral and bilateral transplantations in 26 patients were analyzed. Corticosteroid therapy was discontinued at least three months prior to transplantation in 13 patients (group 1), whereas in 14 cases, the patients continued their daily corticosteroid therapy to the time of transplantation (prednisolone, 0.1 to 0.3 mg/kg/day; group 2). There were no significant differences between the groups with respect to sex, age, diagnosis, or type of transplantation. One limited bronchial dehiscence occurred; the incidence of postoperative bronchial stenosis was identical in both cohorts; one patient died in each group. In conclusion, no increased morbidity or mortality could be found following lung transplantation with regular preoperative administration of prednisolone up to 0.3 mg/kg/day. Thus, patients who cannot be weaned from their steroid medication but who otherwise are acceptable candidates should not be excluded from lung transplantation.
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We present the case of a 67-year-old male patient with mediastinal and retroperitoneal fibrosis. In Europe, this is a rare disease. Treatment was established to prevent complications due to strictures or compressions. Because of his diabetes, a therapy of low-dose prednisone combined with mycophenolate mofetil, known as steroid sparing agent, was applied. As a result, the radiological follow-up showed a marked decrease in the mediastinal and retroperitoneal masses.
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The diagnosis of an acute asthmatic attack in a child is made on a clinical basis. The severity of the exacerbation can be assessed by physical examination and measurement of the transcutaneous oxygenation saturation. A blood gas analysis can be helpful in this assessment. A child with a severe asthma exacerbation should be promptly referred to an emergency department of a hospital. Oxygen should be given to keep the oxygen saturation above 92% and short-acting, selective beta-2 agonists should be administered. Beta-2 agonists can be delivered by intermittent nebulization, continuous nebulization or by metered dose inhaler (MDI) with a spacer They can also be given intravenously in patients who are unresponsive to escalating therapy. The early administration of systemic corticosteroids is essential for the management of acute asthma in children. When tolerated, systemic corticoseroids can be given orally but inhaled corticosteroids are not recommended. Oxygen delivery, beta-2 agonists and steroid therapy are the mainstay of emergency treatment. Hypovolemia should be corrected either intravenously or orally. Administration of multiple doses of ipratropium bromide has been shown to decrease the hospitalization rate in children and adolescents with severe asthma. Clinical response to initial treatment is the main criterion for hospital admission. Patients with failure to respond to treatment should be transferred to an intensive care unit. A critical aspect of management of the acute asthma attack in a child is the prevention of similar attacks in the future.
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BACKGROUND: The relationship between uveitis anterior in childhood and juvenile chronic arthritis (JCA, respectively JRA) has been known since 1950. In a review, the clinical picture of uveitis anterior, its prevalence, pathogenesis, prognosis and current therapy of ocular complications are presented. In addition, we will report our results of a clinical study. PATIENTS AND METHODS: In a cross-sectional study, 64 patients with juvenile chronic arthritis (JCA) had an ophthalmological screening for eye complications either from the disease itself or from the treatment. RESULTS: In 16% of the patients, an iridocyclitis was found, in one case acute, in 9 cases chronic. The cases of chronic uveitis anterior showed in 43% a combination with the classic risk factors (ANA-positive, oligoarticular, female). At the beginning of uveitis, the patients had a mean age of 81 months, at the beginning of JCA disease a mean age of 37 months. Four of 10 patients (= 40%) had eye complications from uveitis (cataract, posterior synechiae, glaucoma). Complications from therapy were found in 27%, mostly cataract as a complication of systemic and topical steroid treatment. Eighteen % had a visual acuity of 0.4 or less. CONCLUSIONS: Because of the often asymptomatic progression of chronic uveitis anterior, the risk of severe undetected eye complications is high. Therefore, an intensive interdisciplinary cooperation between rheumatologists, pediatrics and ophthalmologists is required.
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The National Institutes of Health (NIH) classification of graft-versus-host disease (GVHD) is a significant improvement over prior classifications, and has prognostic implications. We hypothesized that the NIH classification of GVHD would predict the survival of patients with GVHD treated with extracorporeal photopheresis (ECP). Sixty-four patients with steroid refractory/dependent GVHD treated with ECP were studied. The 3-year overall survival (OS) was 36% (95% confidence interval [CI] 13-59). Progressive GVHD was seen in 39% of patients with any acute GVHD (aGVHD) (classic acute, recurrent acute, overlap) compared to 3% of patients with classic chronic GVHD (cGVHD) (P=.002). OS was superior for patients with classic cGVHD (median survival, not reached) compared to overlap GVHD (median survival, 395 days, 95% CI 101 to not reached) and aGVHD (delayed, recurrent or persistent) (median survival, 72 days, 95% CI 39-152). In univariate analyses, significant predictors of survival after ECP included GVHD subtype, bilirubin, platelet count, and steroid dose. In multivariate analyses overlap plus classic cGVHD was an independent prognostic feature predictive of superior survival (hazard ratio [HR] 0.34, 95% CI 0.14-0.8, p=.014). This study suggests that NIH classification can predict outcome after ECP for steroid refractory/dependent GVHD.
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A 27-year-old Caucasian (gravida 2 para 1) presented in week 16 of her twin pregnancy with worsening of hyperandrogenic symptoms. In week 17, she developed an acute abdomen due to a twisted, incarcerated right ovary, which was surgically removed. Histological analysis revealed a diffuse steroid cell hyperplasia. Postsurgery testosterone levels fell temporarily within normal limits, diminishing the hyperandrogenic symptoms. Over time androgen levels rose again slowly above normal values with clinical worsening of hirsutism. In the 32nd week of gestation, a cesarean section of two healthy female infants was necessary due to the development of preeclampsia. An ovarian biopsy revealed again the picture of hyperreactio luteinalis. Postpartum peripheral hormone levels fell within normal limits and the hyperandrogenic symptoms subsided.
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In the kidney, progesterone is inactivated to 20alpha-dihydro-progesterone (20alpha-DH-progesterone) to protect the mineralocorticoid receptor from progesterone excess. In an attempt to clone the enzyme with 20alpha-hydroxysteroid activity using expression cloning in CHOP cells and a human kidney expression library, serendipitously cDNA encoding CYP27A1 was isolated. Overexpression of CYP27A1 in CHOP cells decreased progesterone conversion to 20alpha-DH-progesterone in a dose-dependent manner, an effect enhanced by cotransfection with adrenodoxin and adrenodoxin reductase. Incubation of CHOP cells with 27-hydroxycholesterol, a product of CYP27A1, increased the ratio of progesterone/20alpha-DH-progesterone in a concentration-dependent manner, indicating that the effect of CYP27A1 overexpression was mediated by 27-hydroxycholesterol. In order to analyze whether these observations are relevant in vivo, progesterone and 20alpha-DH-progesterone were measured by GC-MS in 24-h urine of CYP27A1 gene knock out (ko) mice and their control wild type (wt) and heterozygote (hz) littermates. In CYP27A1 ko mice, urinary progesterone concentrations were decreased, 20alpha-DH-progesterone increased and the progesterone/20alpha-DH-progesterone ratio decreased threefold (p<0.001). Thus, CYP27A1 modulates progesterone concentrations. The underlying mechanism is inhibition of 20alpha-hydroxysteroid dehydrogenase by 27-hydroxycholesterol. Key words: Progesterone, sterol 27-hydroxylase, 27-hydroxycholesterol, 20a-steroid dehydrogenase, 20a-DH-progesterone.
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Hyperkalemia is a common life-threatening problem in hemodialysis patients. Because glycyrrhetinic acid (GA) inhibits the enzyme 11beta-hydroxy-steroid dehydrogenase II and thereby increases cortisol availability to the colonic mineralocorticoid receptor, it has the potential to lower serum potassium concentrations. To test this, 10 patients in a 6 month prospective, double-blind, placebo-controlled crossover study were given cookies or bread rolls supplemented with glycyrrhetinic acid or placebo. Twenty-four-hour blood pressure measurements were performed at baseline and week 6 and 12 of each treatment period. The ratio of plasma cortisol/cortisone was significantly increased in all patients on GA as compared to baseline or placebo, indicating appropriate enzyme inhibition. Nine of the 10 patients had a persistent decrease in predialysis serum potassium concentration. On GA, mean predialysis serum potassium was significantly lower than at baseline or on placebo. On placebo, serum potassium was significantly elevated above the upper limit of normal in 76% compared to 30% of measurements during GA treatment. Furthermore, on this treatment the frequency of severe hyperkalemia significantly decreased from 9% to 0.6%. No differences were found in parameters reflecting sodium retention. Although these studies show that prolonged GA supplementation persistently lowers serum potassium in dialysis patients, a long-term toxicity study will be mandatory before we recommend the routine use of this treatment.
Resumo:
Although osteoporosis is a systemic disease, vertebral fractures due to spinal bone loss are a frequent, sometimes early and often neglected complication of the disease, generally associated with considerable disability and pain. As osteoporotic vertebral fractures are an important predictor of future fracture risk, including at the hip, medical management is targeted at reducing fracture risk. A literature search for randomized, double-blind, prospective, controlled clinical studies addressing medical treatment possibilities of vertebral fractures in postmenopausal Caucasian women was performed on the leading medical databases. For each publication, the number of patients with at least one new vertebral fracture and the number of randomized patients by treatment arm was retrieved. The relative risk (RR) and the number needed to treat (NNT, i.e. the number of patients to be treated to avoid one radiological vertebral fracture over the duration of the study), together with the respective 95% confidence intervals (95%CI) were calculated for each study. Treatment of steroid-induced osteoporosis and treatment of osteoporosis in men were reviewed separately, based on the low number of publications available. Forty-five publications matched with the search criteria, allowing for analysis of 15 different substances tested regarding their anti-fracture efficacy at the vertebral level. Bisphosphonates, mainly alendronate and risedronate, were reported to have consistently reduced the risk of a vertebral fracture over up to 50 months of treatment in four (alendronate) and two (risedronate) publications. Raloxifene reduced vertebral fracture risk in one study over 36 months, which was confirmed by 48 months' follow-up data. Parathormone (PTH) showed a drastic reduction in vertebral fracture risk in early studies, while calcitonin may also be a treatment option to reduce fracture risk. For other substances published data are conflicting (calcitriol, fluoride) or insufficient to conclude about efficacy (calcium, clodronate, etidronate, hormone replacement therapy, pamidronate, strontium, tiludronate, vitamin D). The low NNTs for the leading substances (ranges: 15-64 for alendronate, 8-26 for risedronate, 23 for calcitonin and 28-31 for raloxifene) confirm that effective and efficient drug interventions for treatment and prevention of osteoporotic vertebral fractures are available. Bisphosphonates have demonstrated similar efficacy in treatment and prevention of steroid-induced and male osteoporosis as in postmenopausal osteoporosis. The selection of the appropriate drug for treatment of vertebral osteoporosis from among a bisphosphonate (alendronate or risedronate), PTH, calcitonin or raloxifene will mainly depend on the efficacy, tolerability and safety profile, together with the patient's willingness to comply with a long-term treatment. Although reduction of vertebral fracture risk is an important criterion for decision making, drugs with proven additional fracture risk reduction at all clinically relevant sites (especially at the hip) should be the preferred options.
Resumo:
Postmenopausal bone loss can be prevented by continuous or intermittent estradiol (E2) administration. Concomitant progestogen therapy is mandatory in nonhysterectomized women to curtail the risk of endometrial hyperplasia or cancer. However, the recurrence of vaginal bleeding induced by sequential progestogen therapy in addition to continuous estrogen administration is one of the reasons for noncompliance to hormone replacement therapy (HRT). Tibolone, a synthetic steroid with simultaneous weak estrogenic, androgenic, and progestational activity, which does not stimulate endometrial proliferation, has recently been proposed for the treatment of climacteric symptoms. To compare the efficacy of conventional oral and transdermal HRT with that of tibolone in the prevention of postmenopausal bone loss, 140 postmenopausal women (age, 52 +/- 0.6 years; median duration of menopause, 3 years) were enrolled in an open 2-year study. Volunteers had been offered a choice between HRT and no therapy (control group, CO). Patients selecting HRT were randomly allocated to one of the following three treatment groups: TIB, tibolone, 2.5 mg/day continuously, orally; PO, peroral E2, 2 mg/day continuously, plus sequential oral dydrogesterone (DYD), 10 mg/day, for 14 days of a 28-day cycle; TTS, transdermal E2 by patch releasing 50 microg/day, plus DYD as above. Bone densitometry of the lumbar spine, upper femur, and whole body was performed using dual-energy X-ray absorptiometry at baseline, and then 6, 12, 18, and 24 months after initiation of therapy. One hundred and fifteen women (82%) completed the 2 years of the study. The dropout rate was similar in each group. Over 2 years, bone preservation was observed in all three treatment groups as compared with controls, without significant differences among treatment regimens. In conclusion, tibolone can be regarded as an alternative to conventional HRT to prevent postmenopausal bone loss.
Resumo:
Endocrine-disrupting compounds (EDCs) are widespread in the aquatic environment and can cause alterations in development, physiological homeostasis and health of vertebrates. Zebrafish, Danio rerio, has been suggested as a model species to identify targets as well as modes of EDC action. In fact, zebrafish has been found useful in EDC screening, in EDC effects assessment and in studying targets and mechanisms of EDC action. Since many of the environmental EDCs interfere with the sex steroid system of vertebrates, most EDC studies with zebrafish addressed disruption of sexual differentiation and reproduction. However, other targets of EDCs action must not be overlooked. For using a species as a toxicological model, a good knowledge of the biological traits of this species is a pre-requisite for the rational design of test protocols and endpoints as well as for the interpretation and extrapolation of the toxicological findings. Due to the genomic resources available for zebrafish and the long experience with zebrafish in toxicity testing, it is easily possible to establish molecular endpoints for EDC effects assessment. Additionally, the zebrafish model offers a number of technical advantages including ease and cost of maintenance, rapid development, high fecundity, optical transparency of embryos supporting phenotypic screening, existence of many mutant strains, or amenability for both forward and reverse genetics. To date, the zebrafish has been mainly used to identify molecular targets of EDC action and to determine effect thresholds, while the potential of this model species to study immediate and delayed physiological consequences of molecular interactions has been instrumentalized only partly. One factor that may limit the exploitation of this potential is the still rather fragmentary knowledge of basic biological and endocrine traits of zebrafish. Information on species-specific features in endocrine processes and biological properties, however, need to be considered in establishing EDC test protocols using zebrafish, in extrapolating findings from zebrafish to other vertebrate species, and in understanding how EDC-induced gene expression changes translate into disease.
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The effects of superovulatory treatment (follicle stimulating hormone [FSH] versus human menopausal gonadotropin [HMG]) and of route of administration (intramuscular versus intravenous) of prostaglandin F2a (PGF2a) on hormonal profiles were determined in 32 Angus x Hereford heifers for breeding and subsequent embryo collection and transfer. Heifers were superstimulated either with FSH (total of 26 milligrams) or HMG (total of 1,050 international units) beginning on days 9 to 12 of an estrous cycle and PGF2a (40 milligrams) was administered at 60 and 72 hours after the beginning of superovulatory treatments. Heifers were artificially inseminated three times at 12-hour intervals beginning 48 hours after PGF2a treatment. Blood serum samples were collected immediately before treatments began and at frequent intervals until embryo collection 288 hours later. Concentrations of luteinizing hormone (LH) and FSH were not affected by hormone treatments, route of PGF2a injection, or interactions between them. Estradiol-17ß (E2-17ß) levels were higher in HMG- than in FSH-treated heifers 60 hours after gonadotropin treatment. Peak concentration of E2-17ß occurred earlier in HMGthan in FSH-treated heifers and earlier in heifers injected with PGF2a intramuscularly than those injected intravenously. Progesterone concentrations were not influenced by treatment or route of PGF2a administration. The progesterone:E2-17ß ratio was higher in FSH- than in HMG-treated heifers 24 hours after the LH peak. The high steroid hormone concentrations in superovulated beef heifers before and after ovulation may lead to asynchrony between stages of embryonic development, a situation that may interfere with the pregnancy outcome of superovulated embryos in recipient animals.