WorldWideScience
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Sex, Sex steroids and Brain injury  

OpenAIRE

Biologic sex and sex steroids are important factors in clinical and experimental stroke and traumatic brain injury (TBI). Laboratory data strongly show that progesterone treatment after TBI reduces edema, improves outcomes and restores blood brain barrier function. Clinical studies to date agree with these data, and there are ongoing human trials for progesterone treatment after TBI. Estrogen has accumulated an impressive reputation as a neuroprotectant when evaluated at physiologically relev...

Herson, Paco S.; Koerner, Ines P.; Hurn, Patricia D.

2009-01-01

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Steroid signaling activation and intracellular localization of sex steroid receptors  

Science.gov (United States)

In addition to stimulating gene transcription, sex steroids trigger rapid, non-genomic responses in the extra-nuclear compartment of target cells. These events take place within seconds or minutes after hormone administration and do not require transcriptional activity of sex steroid receptors. Depending on cell systems, activation of extra-nuclear signaling pathways by sex steroids fosters cell cycle progression, prevents apoptosis, leads to epigenetic modifications and increases cell migration through cytoskeleton changes. These findings have raised the question of intracellular localization of sex steroid receptors mediating these responses. During the past years, increasing evidence has shown that classical sex steroid receptors localized in the extra-nuclear compartment or close to membranes of target cells induce these events. The emerging picture is that a process of bidirectional control between signaling activation and sex steroid receptor localization regulates the outcome of hormonal responses in target cells. This mechanism ensures cell cycle progression in estradiol-treated breast cancer cells, and its derangement might occur in progression of human proliferative diseases. These findings will be reviewed here together with unexpected examples of the relationship between sex steroid receptor localization, signaling activation and biological responses in target cells. We apologize to scientists whose reports are not mentioned or extensively discussed owing to space limitations. PMID:21234121

Giraldi, Tiziana; Giovannelli, Pia; Di Donato, Marzia; Migliaccio, Antimo; Auricchio, Ferdinando

2010-01-01

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Sex steroids and their receptors in lampreys.  

Science.gov (United States)

The use of steroids and their receptors as ligand-gated transcription factors is thought to be an important step in vertebrate evolution. The lamprey is the earliest-evolving vertebrate to date in which sex steroids and their receptors have been demonstrated to have hormonal roles similar to those found in jawed vertebrates. Sex steroids and their receptors have been examined in several lamprey species, and the majority of studies have focused on the sea lamprey, Petromyzon marinus. While classical steroids appear to be present in lampreys, their function, concentrations, and synthesis have not been determined conclusively. The only classical steroid that is thought to act as a hormone in both males and females is estradiol. Recent research has established that lampreys produce and circulate 15alpha-hydroxylated steroids, and that these steroids respond to upstream stimulation within the hypothalamic-pituitary-gonadal axis. In particular, 15alpha-hydroxyprogesterone is highly sensitive and responds in great magnitude to stimulation, and is likely a hormone. Lampreys also appear to use androstenedione, a precursor to vertebrate androgens, as their main androgen, and a receptor for androstenedione has recently been described. Non-classical steroids are prevalent in many aquatic vertebrates, and the non-classical steroids found in the sea lamprey may represent an evolutionary artifact, or alternatively may be a way to avoid endocrine disruption when ingesting the body fluids of host fish. The lamprey will continue to be an interesting model for examining the evolution of steroid hormones, steroid receptors, and steroid function. PMID:17931674

Bryan, Mara B; Scott, Alexander P; Li, Weiming

2008-01-01

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Application of Rapid and Simul­taneous Measurement of Sex Steroid Hormones to the Monitoring of Gonadotropin Therapy  

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Full Text Available A high performance liquid chromatographic (HPLC method with both electrochemical detection (ECD and ultraviolet spectrometric detection (UVD was developed for the rapid and simultaneous measurement of estradiol (E2, estrone (E1, testosterone (T, 17 alpha-hydroxyprogesterone (17-OHP and progesterone (P in serum. These hormones were extracted with diethylether, and chromatographed on an octadecyl silane-silica (ODS column with an eluent of a phosphate buffer solution - acetonitrile mixture (volume ratio 49:51. Estrogens were detected by ECD at +1.0 V vs. Ag/AgCl, and other hormones by UVD at 242 nm. With this method, the simultaneous determination of sex steroid hormones could be performed within approximately two hours with high precision. The hormones of 34 patients (39 menstrual cycles undergoing human menopausal gonadotropin (HMG-human chorionic gonadotropin (HCG therapy were measured. It was concluded that the switch from HMG to HCG should be performed when the E2 level reaches 400 pg/ml for ovulation and 800 pg/ml for pregnancy. The occurrence of ovarian hyperstimulation syndrome (OHSS can be predicted when the P level rises above 30 ng/ml on the 7th day after the switch. Moreover, conception may be indicated when the P level does not increase from the 7th to 14th day after the switch. In this way, this method proved to be useful for the monitoring of HMG-HCG therapy.

Hayata,Koshi

1985-06-01

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Hepatic tumors induced by sex steroids.  

Science.gov (United States)

Our study of more than 250 women with hepatic tumors, accessioned in our tumor registry at the University of Louisville, disclosed three types of tumor: FNH , HCA, and HCC. The ingestion of sundry kinds of sex steroids by the majority of these women, chiefly for purposes of preventing conception, warrants the suspicion that such hormones induced these different types of hepatic tumors. Publications by others reporting similar hepatic tumors in men using male sex steroids lends support to this hypothesis. Rupture of the hepatic tumor and consequent hemorrhage, producing hemoperitoneum, is a major risk factor. Other presenting symptoms are pain and palpable mass. Symptomatic women using OCs should be subjected to a CT or technetium hepatic scan as an initial screening assessment. Because of the imminent possibility of rupture, large turgid vascular tumors should be resected without biopsy. Biopsy-proved HCC should also be removed surgically. All other tumors, including small multiple tumors, will usually regress when exogenous sex steroids are withdrawn and pregnancy avoided. Other significant hepatic changes observed in this study are peliosis hepatis, periportal sinusoidal dilation, and vascular lesions. The branches of the hepatic artery and the tributaries of the portal vein show combinations of intimal and smooth muscle proliferation, vascular thickening, occlusive intimal thickening, and, at times, obstructing thrombosis. Similar smooth muscle proliferation in the afferent vessels of the livers of animals treated with sex steroids suggests that there is a cause and effect relationship in women using OCs. PMID:6087460

Mays, E T; Christopherson, W

1984-05-01

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Sex Steroid Effects at Target Tissues: Mechanisms of Action  

Science.gov (United States)

This review outlines new advances in our understanding of the spectrum of steroid hormone ligands, newly recognized target tissues, structure-function relationships of steroid receptors, and, finally, their genomic and nongenomic actions. Sex-based specific effects are often related to the different steroid hormone mileu in men compared with women. Understanding the mechanisms of sex steroid action gives insight into the differences in normal physiology and disease states.

Margaret E. Wierman (University of Colorado Veterans Affairs Medical Center)

2007-03-01

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Developmental synergism of steroidal estrogens in sex determination.  

OpenAIRE

Gonadal sex in the red-eared slider turtle, Trachemys scripta, is determined by incubation temperature during embryonic development. Evidence suggests that temperature determines sex by influencing steroid hormone metabolism and/or sensitivity: steroidogenic enzyme inhibitors or exogenous sex steroid hormones and their man-made analogs override (or enhance) temperature effects on sex determination. Specifically, nonaromatizable androgens and aromatase inhibitors induce testis differentiation ...

Bergeron, J. M.; Willingham, E.; Osborn, C. T.; Rhen, T.; Crews, D.

1999-01-01

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Urinary Sex Steroid Excretion Levels During a Soy Intervention Among Young Girls: A Pilot Study  

OpenAIRE

Soy intake early in life may protect against breast cancer later in life, possibly by altering sex hormone metabolism. We evaluated the feasibility of assessing urinary sex steroid excretion among 20 young girls aged 8–14 yr in an 8-wk trial. The girls consumed one daily soy serving, collected weekly overnight urine samples, and reported Tanner stages for breast and pubic hair development. Sex steroid excretion was measured in duplicate by gas chromatography-mass spectrometry and adjusted f...

Maskarinec, Gertraud; Morimoto, Yukiko; Franke, Adrian A.; Novotny, Rachel; Nordt, Frank J.; Stanczyk, Frank Z.

2005-01-01

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The influence of sex steroids on pineal enzymes  

International Nuclear Information System (INIS)

The influence of the gonadal sex steroids namely, estradiol, progesterone and testosterone on the two major enzymes responsible for the synthesis of melatonin in the pineal gland was investigated. These enzymes are Serotonin-N-acetyltransferase (SNAT) and Hydroxyindole-O-methyltransferase (H10MT). Testosterone was found to be the only sex steroid capable of influencing SNAT activity whereas all three of the sex steroids were found to influence H10MT activity in a biphasic dose-dependent manner. The influence of these sex steroids on radiolabelled serotonin metabolism by pineals in organ culture was also investigated. Ovariectomy, castration and the sex steroids were all found to alter the pattern of the radiolabelled serotonin metabolism by these pineal glands in organ culture

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Digit Ratio (2D:4D: A biomarker for prenatal sex steroids and adult sex steroids in challenge situations  

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Full Text Available Digit ratio (2D:4D, which denotes the relative length of the 2nd and 4th digits, is considered to be a biomarker of the balance between foetal testosterone and oestrogen in a narrow window of early ontogeny. Evidence from this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that there is little in the way of associations. Here we suggest that in order to understand the link between 2D:4D and sex hormones one must consider both foetal organising and adult activating effects of testosterone and oestrogen. In particular, we hypothesise that 2D:4D correlates with early organising effects on the endocrine system that moderate activating effects in adulthood. We argue that this can be especially observed through an elevated propensity in adults to produce testosterone in “challenging” conditions such as aggressive and sexual encounters. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression.

JohnManning

2014-01-01

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Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.  

Science.gov (United States)

Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in "challenging" conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression. PMID:24523714

Manning, John; Kilduff, Liam; Cook, Christian; Crewther, Blair; Fink, Bernhard

2014-01-01

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Sex steroid receptor evolution and signalling in aquatic invertebrates.  

Science.gov (United States)

In vertebrate reproductive endocrinology sex steroids play a pivotal role via binding to receptors. However, information on the origin and relevance of sex steroids in invertebrates is limited. This review highlights current literature on steroid receptors in aquatic invertebrates and reports on some new findings. It has been shown that invertebrates of the deuterostome clade, such as Acrania and Echinodermata, respond to estrogens and androgens and, at least in Branchiostoma, an estrogen receptor has been cloned. Within the protostomes, most findings are related to aquatic molluscs. Sex steroid receptor-like proteins are abundant in gastropods, bivalves and cephalopods and also sex hormone signalling shows partial similarity to the deuterostomes. In ecdysozoans, however, the impact of sex steroids is still a matter of debate even though there is evidence on the presence of estrogen receptor-like proteins in Crustacea and on physiological effects of estrogens in both Nematoda and Crustacea. Recent findings suggest the presence of an estrogen receptor alpha-like protein of unclear physiological role in Gammarus fossarum (Crustacea). Binding studies revealed the crustacean Hyalella azteca to possess specific binding sites only for androgens but not for estrogens suggesting a possible limitation to functional androgen receptors in this species. Further studies have to be conducted to shed more light into the discussion about the controversy about sex steroid receptors in invertebrates. PMID:17219085

Köhler, Heinz-R; Kloas, Werner; Schirling, Martin; Lutz, Ilka; Reye, Anna L; Langen, Jan-S; Triebskorn, Rita; Nagel, Roland; Schönfelder, Gilbert

2007-02-01

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Accuracy of methods of sex steroid determination  

OpenAIRE

Reproductive hormones (estrogenic and androgenic steroids) enter natural water bodies from various sources, e.g. human sewage, farmed livestock and vertebrate wildlife. A previous Defra research study (SF0241 Impacts of intensive in-river aquaculture on wild salmonids) reported very high concentrations of such steroids in two UK rivers (the River Test and R. Avon in Hampshire/Wiltshire) in the vicinity of trout farms. The mean reported concentrations of the natural steroids 11-ketotestosteron...

Ellis, T.; Scott, A. P.; Waring, C.; Margiotta-casaluci, L.; Pottinger, T. G.; Morris, S.; Sumpter, J. P.

2011-01-01

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Influence of sex steroid hormones on cerebrovascular function.  

Science.gov (United States)

The cerebral vasculature is a target tissue for sex steroid hormones. Estrogens, androgens, and progestins all influence the function and pathophysiology of the cerebral circulation. Estrogen decreases cerebral vascular tone and increases cerebral blood flow by enhancing endothelial-derived nitric oxide and prostacyclin pathways. Testosterone has opposite effects, increasing cerebral artery tone. Cerebrovascular inflammation is suppressed by estrogen but increased by testosterone and progesterone. Evidence suggests that sex steroids also modulate blood-brain barrier permeability. Estrogen has important protective effects on cerebral endothelial cells by increasing mitochondrial efficiency, decreasing free radical production, promoting cell survival, and stimulating angiogenesis. Although much has been learned regarding hormonal effects on brain blood vessels, most studies involve young, healthy animals. It is becoming apparent that hormonal effects may be modified by aging or disease states such as diabetes. Furthermore, effects of testosterone are complicated because this steroid is also converted to estrogen, systemically and possibly within the vessels themselves. Elucidating the impact of sex steroids on the cerebral vasculature is important for understanding male-female differences in stroke and conditions such as menstrual migraine and preeclampsia-related cerebral edema in pregnancy. Cerebrovascular effects of sex steroids also need to be considered in untangling current controversies regarding consequences of hormone replacement therapies and steroid abuse. PMID:16794020

Krause, Diana N; Duckles, Sue P; Pelligrino, Dale A

2006-10-01

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Sex steroids and food intake in fish  

OpenAIRE

This study was conducted to test the sensitivity to gonadal steroids of the systems regulating food intake in sea bass. Animals were treated with silastic implants containing 17-?-estradiol or testosterone. Self-feeding was recorded for 31 days using computerized demand feeders and unfed-pellet recovery systems. Both steroids strongly decreased selffeeding levels, feed efficiency and specific growth rates. The linear growth of fish treated with testosterone was higher than in 17-?-estradiol...

Leal, Esther; Sa?nchez, Elisa; Muriach, Borja; Cerda?-reverter, Jose? Miguel

2009-01-01

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Sex Differences and Sex Steroids in Lung Health and Disease  

OpenAIRE

Sex differences in the biology of different organ systems and the influence of sex hormones in modulating health and disease are increasingly relevant in clinical and research areas. Although work has focused on sex differences and sex hormones in cardiovascular, musculoskeletal, and neuronal systems, there is now increasing clinical evidence for sex differences in incidence, morbidity, and mortality of lung diseases including allergic diseases (such as asthma), chronic obstructive pulmonary ...

Townsend, Elizabeth A.; Miller, Virginia M.; Prakash, Y. S.

2012-01-01

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Multiple Sclerosis in relation to sex steroid exposure  

OpenAIRE

Multiple sclerosis (MS) is a potentially severe chronic inflammatory disease of the central nervous system (CNS) and is usually diagnosed between 20 and 40 years of age. The incidence of MS is two to three times higher among women and the type and course of the disease often differ between the sexes. Sex steroids, especially estrogens, have been shown to influence the immunopathology involved in MS and the mouse model experimental allergic encephalomyelitis (EAE), as well as radiological and ...

Kempe, Per

2014-01-01

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Steroid receptor expression in the fish inner earvaries with sex, social status, and reproductive state  

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Full Text Available Abstract Background Gonadal and stress-related steroid hormones are known to influence auditory function across vertebrates but the cellular and molecular mechanisms responsible for steroid-mediated auditory plasticity at the level of the inner ear remain unknown. The presence of steroid receptors in the ear suggests a direct pathway for hormones to act on the peripheral auditory system, but little is known about which receptors are expressed in the ear or whether their expression levels change with internal physiological state or external social cues. We used qRT-PCR to measure mRNA expression levels of multiple steroid receptor subtypes (estrogen receptors: ER?, ER?a, ER?b; androgen receptors: AR?, AR?; corticosteroid receptors: GR2, GR1a/b, MR and aromatase in the main hearing organ of the inner ear (saccule in the highly social African cichlid fish Astatotilapia burtoni, and tested whether these receptor levels were correlated with circulating steroid concentrations. Results We show that multiple steroid receptor subtypes are expressed within the main hearing organ of a single vertebrate species, and that expression levels differ between the sexes. We also show that steroid receptor subtype-specific changes in mRNA expression are associated with reproductive phase in females and social status in males. Sex-steroid receptor mRNA levels were negatively correlated with circulating estradiol and androgens in both males and females, suggesting possible ligand down-regulation of receptors in the inner ear. In contrast, saccular changes in corticosteroid receptor mRNA levels were not related to serum cortisol levels. Circulating steroid levels and receptor subtype mRNA levels were not as tightly correlated in males as compared to females, suggesting different regulatory mechanisms between sexes. Conclusions This is the most comprehensive study of sex-, social-, and reproductive-related steroid receptor mRNA expression in the peripheral auditory system of any single vertebrate. Our data suggest that changes in steroid receptor mRNA expression in the inner ear could be a regulatory mechanism for physiological state-dependent auditory plasticity across vertebrates.

Fernald Russell D

2010-04-01

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Influence of sex and oral contraceptive steroids on paracetamol metabolism.  

OpenAIRE

Paracetamol metabolism was investigated in eight healthy males, eight healthy females and eight healthy females receiving oral contraceptive steroids (OCS). Paracetamol clearance was 22% greater in males compared to the control female group. This difference was entirely due to increased activity of the glucuronidation pathway in males, there being no sex-related differences in the sulphation or oxidative metabolism of paracetamol. Paracetamol clearance in females using OCS was 49% greater tha...

Miners, J. O.; Attwood, J.; Birkett, D. J.

1983-01-01

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No sex difference in yolk steroid concentrations of avian eggs at laying  

OpenAIRE

Yolk steroids of maternal origin have been proposed to influence genetic sex determination in birds, based on sex differences in yolk steroid concentrations of peafowl eggs incubated for 10 days. More recent reports dispute this proposal, as yolk steroids in eggs incubated for 3 days do not show such sex differences. To date, research examining this phenomenon has only analysed incubated eggs, although sex in avian species is determined before incubation begins. This may be a serious methodol...

Pilz, Kevin M.; Adkins-regan, Elizabeth; Schwabl, Hubert

2005-01-01

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Associations between polymorphisms in sex steroid related genes and autistic-like traits.  

Science.gov (United States)

Sex differences in psychiatric disorders are common, which is particularly striking in autism spectrum disorders (ASDs) that are four times more prevalent in boys. High levels of testosterone during early development have been hypothesized to be a risk factor for ASDs, supported by several studies showing fetal testosterone levels, as well as indirect measures of prenatal androgenization, to be associated with ASDs and autistic-like traits (ALTs). Further, the importance of sex steroid related genes in ASDs is supported by studies reporting associations between polymorphisms in genes involved in sex steroid synthesis/metabolism and ASDs and ALTs. The aim of the present study was to investigate possible associations between 29 single nucleotide polymorphisms (SNPs) in eight genes related to sex steroids and autistic features. Individuals included in the study belong to a subset (n=1771) from The Child and Adolescent Twin Study in Sweden (CATSS), which are all assessed for ALTs. For two SNPs, rs2747648 located in the 3'-UTR of ESR1 encoding the estrogen receptor alpha and rs523349 (Leu89Val) located in SRD5A2 encoding 5-alpha-reductase, type 2, highly significant associations with ALTs were found in boys and girls, respectively. The results of the present study suggest that SNPs in sex steroid related genes, known to affect gene expression (rs2747648 in ESR1) and enzymatic activity (Leu89Val in SRD5A2), seem to be associated with ALTs in a general population. In conclusion, the current findings provide further support for a role of sex steroids in the pathophysiology of ASDs. PMID:23867117

Zettergren, Anna; Jonsson, Lina; Johansson, Daniel; Melke, Jonas; Lundström, Sebastian; Anckarsäter, Henrik; Lichtenstein, Paul; Westberg, Lars

2013-11-01

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Factors That Contribute to Assay Variation in Quantitative Analysis of Sex Steroid Hormones Using Liquid and Gas Chromatography-Mass Spectrometry  

Science.gov (United States)

The list of physiological events in which sex steroids play a role continues to increase. To decipher the roles that sex steroids play in any condition requires high quality cohorts of samples and assays that provide highly accurate quantitative measures. Liquid and gas chromatography coupled with mass spectrometry (LC-MS and GC-MS) have…

Xu, Xia; Veenstra, Timothy D.

2012-01-01

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Serum-sex steroids, gonadotrophins and sex hormone-binding globulin inprostatic hyperplasia  

International Nuclear Information System (INIS)

Benign prostatic hyperplasia (BPH) develops in elderly males when serumandrogens are relatively lower than in healthy younger males, but is not wellunderstood whether and how sex steroids are altered in prostatic hyperplasia.It is also uncertain that whether there is any change in sex steroids levelsin males older than 40 years of age. The use of androgens in elderly males isoften discouraged because of the probable worsening effect of androgens onprostatism. This study aimed to determine the relationship between prostatichyperplasia and sex steroid levels and whether there is any significantchange in these hormones after the age of 40 years. We studied healthy malesof >40 years with (n=92) or without (n=93) clinical prostatic hyperplasia.Serum testosterone, estradiol, gonadotrophins and sex hormone-bindingglobulin (SHBG) were compared. The hormones and SHGB were also correlatedwith age. No significant difference was found in any hormone in cases withprostatic hyperplasia as compared with the controls. There was no significantage-related change in any hormone except estradiol where as a negativecorrelation (P<0.003) with age was found. Serum sex steroids and SHGBremained unchanged in symptomatic prostatic hyperplasia and except forestrdoil there was no significant age-related change in serum testosterone,gonadotrophins and SHGB in healthy males after the fourth decade. Morestudies are needed to confirm the age-related decline of estrogens in males.(author)of estrogens in males.(author)

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Controlled ovarian hyperstimulation: are we monitoring the appropriate sex-steroid hormones?  

Science.gov (United States)

We prospectively evaluated the behavior of serum 17-hydroxyprogesterone (17-OHP), sex-steroid hormones, and C-reactive protein (CRP) levels in 27 patients during controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF). While routine measurement of COH via serum 17-OHP may replace estradiol (E(2)) and progesterone levels, additional studies are needed to elucidate the ceiling level of serum 17-OHP beyond which intervention is required to prevent severe ovarian hyperstimulation syndrome. PMID:17658530

Orvieto, Raoul; Hod, Eduard; Volodarsky, Michael; Homburg, Roy; Rabinson, Jacob; Meltcer, Simion

2008-05-01

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Acute Effects of Sex Steroid Hormones on Susceptibility to Cardiac Arrhythmias: A Simulation Study  

OpenAIRE

Acute effects of sex steroid hormones likely contribute to the observation that post-pubescent males have shorter QT intervals than females. However, the specific role for hormones in modulating cardiac electrophysiological parameters and arrhythmia vulnerability is unclear. Here we use a computational modeling approach to incorporate experimentally measured effects of physiological concentrations of testosterone, estrogen and progesterone on cardiac ion channel targets. We then study the hor...

Yang, Pei-chi; Kurokawa, Junko; Furukawa, Tetsushi; Clancy, Colleen E.

2010-01-01

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The association of urinary cadmium with sex steroid hormone concentrations in a general population sample of US adult men  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Studies investigating the association of cadmium and sex steroid hormones in men have been inconsistent, but previous studies were relatively small. Methods In a nationally representative sample of 1,262 men participating in the morning examination session of phase I (1998–1991 of the third National Health and Nutrition Examination Survey, creatinine corrected urinary cadmium and serum concentrations of sex steroid hormones were measured following a standardized protocol. Results After adjustment for age and race-ethnicity, higher cadmium levels were associated with higher levels of total testosterone, total estradiol, sex hormone-binding globulin, estimated free testosterone, and estimated free estradiol (each p-trend 0.05. Conclusion Urinary cadmium levels were not associated with sex steroid hormone concentrations in a large nationally representative sample of US men.

Basaria Shehzad

2008-02-01

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Early pregnancy sex steroids and maternal risk of epithelial ovarian cancer.  

Science.gov (United States)

Well-established associations between reproductive characteristics and epithelial ovarian cancer (EOC) support an involvement of sex steroid hormones in the etiology of EOC. Limited previous studies have evaluated circulating androgens and the risk of EOC, and estrogens and progesterone have been investigated in only one of the previous studies. Furthermore, there is little data on potential heterogeneity in the association between circulating hormones and EOC by histological subgroup. Therefore, we conducted a nested case-control study within the Finnish Maternity Cohort and the Northern Sweden Maternity Cohort to investigate the associations between circulating pre-diagnostic sex steroid concentrations and the histological subtypes of EOC. We identified 1052 EOC cases among cohort members diagnosed after recruitment (1975-2008) and before March 2011. Up to three controls were individually matched to each case (n=2694). Testosterone, androstenedione, 17-hydroxyprogesterone (17-OHP), progesterone, estradiol (E2), and sex hormone-binding globulin levels were measured in serum samples collected during the last pregnancy before EOC diagnosis. We used conditional logistic regression to estimate odds ratios (ORs) and 95% CIs. Associations between hormones and EOC differed with respect to tumor histology and invasiveness. Sex steroid concentrations were not associated with invasive serous tumors; however, doubling of testosterone and 17-OHP concentration was associated with approximately 40% increased risk of borderline serous tumors. A doubling of androgen concentrations was associated with a 50% increased risk of mucinous tumors. The risk of endometrioid tumors increased with higher E2 concentrations (OR: 1.89 (1.20-2.98)). This large prospective study in pregnant women supports a role of sex steroid hormones in the etiology of EOC arising in the ovaries. PMID:25270324

Schock, Helena; Surcel, Heljä-Marja; Zeleniuch-Jacquotte, Anne; Grankvist, Kjell; Lakso, Hans-Åke; Fortner, Renée Turzanski; Kaaks, Rudolf; Pukkala, Eero; Lehtinen, Matti; Toniolo, Paolo; Lundin, Eva

2014-01-01

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Sex steroid modulation of AT2 receptors in human myometrium.  

Science.gov (United States)

In contrast to the abundant expression of the AT2 subtype of angiotensin II (AII) receptors during fetal development, AT2 receptor in adult life is expressed in few tissues. We now report studies on the presence and hormonal regulation of AT2 receptor in human pregnant and nonpregnant myometrium obtained from a large study population (n = 50). AT2 receptor subtypes have been characterized using self- and cross-competition curves among [125I]CGP42112A (a selective AT2 ligand), [125I](Sar1,Ile8)AII (a unselective antagonist), the corresponding unlabeled ligands, and several peptidic and nonpeptidic analogs with different affinities for the AT1 and AT2 receptor subtypes. We found that the human nonpregnant uterus expresses almost exclusively the AT2 subtype, and that [125I]CGP42112A is a selective probe to study human AT2 receptor. By using [125I]CGP42112A, we demonstrated that the density of AT2 receptor in human myometrium is dramatically affected by the hormonal milieu. Indeed, in the estrogen-dominant uterus of normal cycling women in the proliferative phase and that of perimenopausal women with anovulatory cycles, the density of binding sites was very high [1565 +/- 246 fmol/mg protein (n = 11) and 2176 +/- 429 (n = 7), respectively]. The concomitant presence of progestogens blunted the estrogen effect [term pregnancy, 61 +/- 12 fmol/mg protein (n = 5); secretive phase of the cycle, 453 +/- 154 (n = 10); combined oral contraceptive, 243 +/- 74 fmol/mg protein (n = 6)]. Very low concentrations of binding sites are also present in the sex steroid-deprived uterus of postmenopausal women (100 +/- 12 fmol/mg protein; n = 8) and the uterus of fertile women chronically treated with GnRH agonists (199 +/- 100 fmol/mg protein; n = 3). Hence, these data confirm the presence of AT2 receptors in human uterus and indicate their regulation by sex steroids. PMID:8626829

Mancina, R; Susini, T; Renzetti, A; Forti, G; Razzoli, E; Serio, M; Maggi, M

1996-05-01

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Augmented transport and metabolism of sex steroids in lymphoid neoplasia in the rat  

International Nuclear Information System (INIS)

Sex steroid hormones have been shown to influence a number of biological properties of lymphoid neoplastic tissue. Receptor occupancy is a function of the pool size of cellular exchangeable hormone therefore it is important to understand the mechanisms regulating hormone transport from the microcirculation and hormone metabolism. In this study, steroid hormone transport and metabolism were investigated in control and neoplastic lymph nodes after transplanting control rats with the WR-6 leukemic line. Steroid hormone transport and metabolism were studied after pulse labeling the nodal tissue in vivo with arterial bolus injections of [3H]testosterone. Residual vascular radioactivity was monitored by simultaneously injecting 113m indium chelated to bovine transferrin. Both testosterone and estradiol were partially available for transport through the capillary barriers of control and neoplastic lymph nodes from the circulating albumin-bound pool. Estradiol was readily available for transport from the circulating sex hormone-binding globulin-bound pool in both control and neoplastic lymph nodes. Testosterone was not available for transport from the sex hormone-binding globulin-bound pool in control lymph nodes, but was readily available for transport in metastatic lymph nodes. Thaw-mount autoradiography and physiological measurements showed that plasma proteins such as albumin or transferrin were confined to the microcirculation compartment. The transport of proculation compartment. The transport of protein-bound hormones into lymph node represents a mechanism of enhanced steroid hormone dissociation from the binding protein without the plasma protein per se significantly exiting the microcirculation compartment. Metabolic studies showed no measurable metabolism of [3H]testosterone in the control lymph nodes by 60 sec after arterial injection

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All sex steroids are made intracellularly in peripheral tissues by the mechanisms of intracrinology after menopause.  

Science.gov (United States)

Following the arrest of estradiol secretion by the ovaries at menopause, all estrogens and all androgens in postmenopausal women are made locally in peripheral target tissues according to the physiological mechanisms of intracrinology. The locally made sex steroids exert their action and are inactivated intracellularly without biologically significant release of the active sex steroids in the circulation. The level of expression of the steroid-forming and steroid-inactivating enzymes is specific to each cell type in each tissue, thus permitting to each cell/tissue to synthesize a small amount of androgens and/or estrogens in order to meet the local physiological needs without affecting the other tissues of the organism. Achieved after 500 million years of evolution, combination of the arrest of ovarian estrogen secretion, the availability of high circulating levels of DHEA and the expression of the peripheral sex steroid-forming enzymes have permitted the appearance of menopause with a continuing access to intratissular sex steroids for the individual cells/tissues without systemic exposure to circulating estradiol. In fact, one essential condition of menopause is to maintain serum estradiol at biologically inactive (substhreshold) concentrations, thus avoiding stimulation of the endometrium and risk of endometrial cancer. Measurement of the low levels of serum estrogens and androgens in postmenopausal women absolutely requires the use of MS/MS-based technology in order to obtain reliable accurate, specific and precise assays. While the activity of the series of steroidogenic enzymes can vary, the serum levels of DHEA show large individual variations going from barely detectable to practically normal "premenopausal" values, thus explaining the absence of menopausal symptoms in about 25% of women. It should be added that the intracrine system has no feedback elements to adjust the serum levels of DHEA, thus meaning that women with low DHEA activity will not be improved without external supplementation. Exogenous DHEA, however, follows the same intracrine rules as described for endogenous DHEA, thus maintaining serum estrogen levels at substhreshold or biologically inactive concentrations. Such blood concentrations are not different from those observed in normal postmenopausal women having high serum DHEA concentrations. Androgens, on the other hand, are practically all made intracellularly from DHEA by the mechanisms of intracrinology and are always maintained at very low levels in the blood in both pre- and postmenopausal women. Proof of the importance of intracrinology is also provided, among others, by the well-recognized benefits of aromatase inhibitors and antiestrogens used successfully for the treatment of breast cancer in postmenopausal women where all estrogens are made locally. Each medical indication for the use of DHEA, however, requires clinical trials performed according to the FDA guidelines and the best rules of clinical medicine. PMID:24923731

Labrie, Fernand

2015-01-01

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Sex steroid dynamics during embryogenesis and sexual differentiation in Eurasian perch, Perca fluviatilis  

OpenAIRE

It is widely accepted that sex steroid hormones play an important and a specific role during the process of sex differentiation in fish. In order to describe the role of the three main sex steroid hormones (testosterone--T, 17beta-estradiol--E2 and 11keto-testosterone--11KT) during embryogenesis and sex differentiation in Eurasian perch, Perca fluviatilis, eggs, larvae and juveniles originating from two mixed-sex and two all-female progenies were regularly sampled from fertilization to hatchi...

Rougeot, Carole; Krim, A.; Mandiki, S. N.; Kestemont, P.; Me?lard, Charles

2007-01-01

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Sex steroid biosynthesis enzymes in ovarian sex-cord stromal tumors.  

Science.gov (United States)

Previous studies on neoplastic and hyperplastic ovarian lesions using paraffin-embedded material have demonstrated immunolocalization of sex steroid biosynthetic enzymes (SSBEs): P-450 side chain cleavage (P-450 SCC), which converts cholesterol to pregnenolone; 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), which converts pregnenolone to progesterone; P-450 17 alpha-hydroxylase and lyase (P-450 17A), which convert progesterone to 17 alpha-hydroxyprogesterone and 4-androstene-3,17-dione; and P-450 aromatase (P-450 AR), which converts 4-androstene-3,17-dione to estradiol. To investigate the utility of immunohistochemical staining for SSBEs, we studied a series of 45 sex cord-stromal tumors of the ovary. P-450 SCC was present in 9 of 11 Sertoli-stromal cell tumors, 3 of 12 granulosa cell tumors, 2 of 7 thecomas, and 1 of 1 stromal luteomas; 3 beta-HSD was present in 5 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, 2 of 7 thecomas, and 1 of 1 stromal luteoma; P-450 17A was present in 5 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, 2 of 6 thecomas, and 1 of 1 stromal luteomas; P-450 AR was present in 6 of 11 Sertoli-stromal cell tumors, 2 of 12 granulosa cell tumors, none of 7 thecomas, and 1 of 1 stromal luteoma. SSBEs were not present in 12 fibromas, one sclerosing stromal tumor, and one myxoma. Five of 45 patients with sex cord-stromal tumors showed androgenic effects; 4 of 11 patients with Sertoli-stromal cell tumors and the patient with a stromal luteoma. These five sex cord-stromal tumors contained P-450 SCC, and three of four of the Sertoli-stromal cell tumors contained 3 beta-HSD, P-450 17A, and P-450 AR. Concurrent endometrial histology was available in 25 of 45 sex cord-stromal tumor patients. None of the five sex cord-stromal tumors arising in patients with endometria that showed hyperplasia or adenocarcinoma showed immunoreactivity for SSBEs. Eight patients' endometria were unremarkable, but their sex cord-stromal tumor contained SSBEs. SSBEs were present in areas showing Leydig cell, Sertoli cell, or steroid cell differentiation or luteinized areas; however, the results did not significantly add to the histologic classification of sex-cord stromal tumors. Androgenic hormonal effects could always be explained by synthesis of hormones by SSBEs present in the patient's sex cord-stromal tumor.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8005731

Costa, M J; Morris, R; Sasano, H

1994-04-01

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Impact of sex and gonadal steroids on neonatal brain structure.  

Science.gov (United States)

There are numerous reports of sexual dimorphism in brain structure in children and adults, but data on sex differences in infancy are extremely limited. Our primary goal was to identify sex differences in neonatal brain structure. Our secondary goal was to explore whether brain structure was related to androgen exposure or sensitivity. Two hundred and ninety-three neonates (149 males) received high-resolution structural magnetic resonance imaging scans. Sensitivity to androgen was measured using the number of cytosine, adenine, guanine (CAG) triplets in the androgen receptor gene and the ratio of the second to fourth digit, provided a proxy measure of prenatal androgen exposure. There was a significant sex difference in intracranial volume of 5.87%, which was not related to CAG triplets or digit ratios. Tensor-based morphometry identified extensive areas of local sexual dimorphism. Males had larger volumes in medial temporal cortex and rolandic operculum, and females had larger volumes in dorsolateral prefrontal, motor, and visual cortices. Androgen exposure and sensitivity had minor sex-specific effects on local gray matter volume, but did not appear to be the primary determinant of sexual dimorphism at this age. Comparing our study with the existing literature suggests that sex differences in cortical structure vary in a complex and highly dynamic way across the human lifespan. PMID:23689636

Knickmeyer, Rebecca C; Wang, Jiaping; Zhu, Hongtu; Geng, Xiujuan; Woolson, Sandra; Hamer, Robert M; Konneker, Thomas; Styner, Martin; Gilmore, John H

2014-10-01

34

Manipulative mothers : maternal steroid hormones and avian offspring sex ratio : studies in the homing pigeon  

OpenAIRE

This thesis deals with the potential involvement of maternal steroid hormones in the manipulation of avian primary sex ratio (the proportion of sons) and the identification of underlying mechanics, using the homing pigeon (Columba livia domestica) as model species.

Vivian Charlotte, Goerlich

2009-01-01

35

Activation of PPAR? by Rosiglitazone Does Not Negatively Impact Male Sex Steroid Hormones in Diabetic Rats  

OpenAIRE

Peroxisome proliferator-activated receptor gamma (PPAR?) activation decreased serum testosterone (T) in women with hyperthecosis and/or polycystic ovary syndrome and reduced the conversion of androgens to estradiol (E2) in female rats. This implies modulation of female sex steroid hormones by PPAR?. It is not clear if PPAR? modulates sex steroid hormones in diabetic males. Because PPAR? activation by thiazolidinedione increased insulin sensitivity in type 2 diabetes, understanding the lon...

Mansour, Mahmoud; Coleman, Elaine; Dennis, John; Akingbemi, Benson; Schwartz, Dean; Braden, Tim; Judd, Robert; Plaisance, Eric; Stewart, Laura Ken; Morrison, Edward

2009-01-01

36

Regulation of Physiological and Metabolic Function of Muscle by Female Sex Steroids  

OpenAIRE

The ability of female sex steroids to regulate tissue function has long been appreciated, however their role in the regulation of striated muscle function has received considerably less attention. The purpose of this symposium review is to document recent evidence indicating the role female sex steroids have in defining the functional characteristics of striated muscle. The presentations provide substantial evidence indicating that estrogens are critical to the physiological and metabolic reg...

Spangenburg, Espen E.; Geiger, Paige C.; Leinwand, Leslie A.; Lowe, Dawn A.

2012-01-01

37

Steroid Hormone Measurement in Epidemiological Studies  

Science.gov (United States)

July 17, 2014 10:30 AM - 11:30 AM Shady Grove, Room TE406 + Add to Outlook Calendar Speaker: Neal E. Craft, Ph.D. President Craft Technologies, Inc. Print This Page Steroid Hormone Measurement in Epidemiological Studies DCEG Seminar News & Events

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Offspring sex in a TSD gecko correlates with an interaction between incubation temperature and yolk steroid hormones  

Science.gov (United States)

We incubated eggs of the Japanese gecko Gekko japonicus at three temperatures, and measured yolk testosterone (T) and 17?-estradiol (E2) levels at three time points in embryonic development (oviposition, 1/3 of incubation, and 2/3 of incubation), to examine whether maternal influence on offspring sex via yolk steroid hormone deposition is significant in the species. Eggs incubated at 24 °C and 32 °C produced mostly females, and eggs incubated at 28 °C almost a 50:50 sex ratio of hatchlings. Female-producing eggs were larger than male-producing eggs. Clutches in which eggs were incubated at the same temperature produced mostly same-sex siblings. Yolk T level at laying was negatively related to eggs mass, and yolk E2/T ratio was positively related to egg mass. Results of two-way ANOVA with incubation temperature and stage as the factors show that: yolk E2 level was higher at 32 °C than at 24 °C; yolk T level was higher, whereas yolk E2/T ratio was smaller, at 28 °C than at 24 °C; yolk E2 and T levels were higher at 2/3 than at 1/3 of incubation. Our data in G. japonucus show that: (1) maternal influence on offspring sex via yolk steroid hormone deposition is significant; (2) incubation temperature affects the dynamics of developmental changes in yolk steroid hormones; (3) influences of yolk steroid hormones on offspring sex are secondary relative to incubation temperature effects; and (4) offspring sex correlates with an interaction between incubation temperature and yolk steroid hormones.

Ding, Guo-Hua; Yang, Jing; Wang, Jin; Ji, Xiang

2012-12-01

39

Measurement of steroid concentrations in brain tissue: methodological considerations  

Directory of Open Access Journals (Sweden)

Full Text Available It is well recognized that steroids are synthesized de novo in the brain (neurosteroids. In addition, steroids circulating in the blood enter the brain. Steroids play numerous roles in the brain, such as influencing neural development, behavior, neuroplasticity, and inflammation. In order to understand the regulation and functions of steroids in the brain, it is important to directly measure steroid concentrations in brain tissue. In this brief review, we discuss methods for the detection and quantification of steroids in the brain. We concisely present the major advantages and disadvantages of different technical approaches at various experimental stages: euthanasia, tissue collection, steroid extraction, steroid separation, and steroid measurement. We discuss, among other topics, the potential effects of anesthesia and saline perfusion prior to tissue collection; microdissection via Palkovits punch; solid phase extraction; chromatographic separation of steroids; and immunoassays and mass spectrometry for steroid quantification, particularly the use of mass spectrometry for “steroid profiling.” Finally, we discuss the interpretation of local steroid concentrations, such as comparing steroid levels in brain tissue with those in the circulation (plasma vs. whole blood samples; total vs. free steroid levels. This brief review highlights some of the major methodological considerations at multiple experimental stages and provides a broad framework for designing studies that examine local steroid levels in the brain as well as other tissues.

MatthewDTaves

2011-09-01

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Digit Ratio (2D:4D): A biomarker for prenatal sex steroids and adult sex steroids in challenge situations  

OpenAIRE

Digit ratio (2D:4D), which denotes the relative length of the 2nd and 4th digits, is considered to be a biomarker of the balance between foetal testosterone and oestrogen in a narrow window of early ontogeny. Evidence from this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroi...

JohnManning; LiamKilduff; CristianCook; BlairCrewther; BernhardFink

2014-01-01

41

No effect of sex steroids on compensatory muscle hypertrophy  

Science.gov (United States)

The effects of orchiectomy and/or subcutaneously implanted testosterone propionate (TP) on the hypertrophic response of rat plantaris muscles to functional overload (induced by bilateral removal of gastrocnemius and soleus muscles) are investigated experimentally. Muscle wet weight, metabolic substrate oxidation, and cytosolic androgen-receptor binding are measured, and the results are presented in tables. Eight weeks after surgery, the plantaris muscle weight as a percentage of body weight is found to be about twice that in rats without muscle overload, regardless of the sex-hormone status. Overloading causes decreased ability to oxidize glucose and pyruvate, decreased succinate dehydrogenase specific activity, and no change in the ability to oxidize beta-hydroxybutyrate or in androgen-receptor binding. The oxidative response is unaffected by orchiectomy or TP or both. It is argued that the actions of sex hormones and functional overload are not synergistic.

Max, S. R.; Rance, N. E.

1984-01-01

42

Analysis of In Vitro Effects of Sex Steroids on Lymphocyte Responsiveness in Murrah Buffaloes (Bubalus bubalis)  

OpenAIRE

Present study was carried out on forty four apparently healthy Murrah buffaloes of different age groups of both sexes to investigate the effects of sex steroids on cell mediated immunity in vitro. Estrogen inhibited proliferation in mitogen-stimulated lymphocytes from prepubertal but not post pubertal buffaloes of either sex. Estrogen at 100?pg/mL concentration stimulating the proliferation significantly (P < 0.05). in all groups and had higher stimulatory effect in lymphocytes from day 10 ...

Zahoor Ahmad Pampori; Sujata Pandita

2012-01-01

43

The epidemiology of sex steroid hormones and their signaling and metabolic pathways in the etiology of prostate cancer.  

Science.gov (United States)

The purpose of this review is to discuss the epidemiologic literature on the association of sex steroid hormones and components of their signaling and metabolic pathways with prostate cancer and to describe data evaluating racial variation in sex steroid hormone pathways as a possible explanation for the notably higher risk of prostate cancer in African-American men compared to white or Asian men. Although sex steroid hormones likely contribute to the growth and progression of prostate cancer, associations between hormones and prostate cancer risk across the range of normal levels have been difficult to reliably demonstrate epidemiologically. Methodologic issues no doubt have made the detection of these associations difficult. Of particular importance are (1) the inadequacy of measuring circulating hormones in middle age as a surrogate for the exposure in the target cells in the prostate at the relevant time in life and (2) the current inability to integrate across components of the sex steroid hormone signaling pathway to fully capture target cell androgenic and estrogenic stimulation. Although the approach of evaluating polymorphisms in genes involved in sex steroid hormone signaling or metabolism as a way to minimize some of the issues in the direct measurement of hormones is logical, the findings among these studies are somewhat difficult to reconcile as well. The problems of the changing case mix due to screening for elevated PSA, small sample sizes increasing the likelihood of false negative and false positive results, the controls and their allele frequencies not being representative of the population at risk, and lack of knowledge of the functional consequence of a polymorphism in relation to other polymorphisms in that gene or without consideration of other genes involved in the same pathway may be contributory. The primary result of the Prostate Cancer Prevention Trial confirms that intraprostatic dihydrotestosterone levels in the normal range indeed do contribute to the growth of prostate adenocarcinoma. However, the secondary result of higher-grade disease in cases in the finasteride arm coupled with clinical studies showing higher grade disease in non-metastatic cases with lower serum androgens, if not a pathological artifact or detection bias in the finasteride arm, possibly suggests a complex relationship between androgens and the growth versus differentiation of a prostate tumor. Finally, racial variation in components of the sex steroid hormone pathway do appear to exist, but whether the extent of the variation is adequately great such that it accounts for some of the substantial differences in prostate cancer incidence among blacks, whites, and Asians is unclear. PMID:15663987

Platz, Elizabeth A; Giovannucci, Edward

2004-11-01

44

Regulation of antioxidant enzyme activities in male and female rat macrophages by sex steroids  

Directory of Open Access Journals (Sweden)

Full Text Available Human and animal immune functions present sex dimorphism that seems to be mainly regulated by sex hormones. In the present study, the activities of the antioxidant enzymes total superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px were measured in intraperitoneal resident macrophages from adult male and female rats. In addition to comparing males and females, we also examined the regulation of these enzyme activities in macrophages by sex steroids. GSH-Px activity did not differ between male and female macrophages. However, both total SOD and CAT activities were markedly higher in females than in males (83 and 180%. Removal of the gonads in both males and females (comparison between castrated groups increased the difference in SOD activity from 83 to 138% and reduced the difference in CAT activity from 180 to 86%. Castration and testosterone administration did not significantly modify the activities of the antioxidant enzymes in male macrophages. Ovariectomy did not affect SOD or GSH-Px activity but markedly reduced (48% CAT activity. This latter change was fully reversed by estrogen administration, whereas progesterone had a smaller effect. These results led us to conclude that differences in the SOD and CAT activities may partially explain some of the differences in immune function reported for males and females. Also, estrogen is a potent regulator of CAT in macrophages and therefore this enzyme activity in macrophages may vary considerably during the menstrual cycle.

Azevedo R.B.

2001-01-01

45

The sensitivity of the child to sex steroids: possible impact of exogenous estrogens  

DEFF Research Database (Denmark)

The current trends of increasing incidences of testis, breast and prostate cancers are poorly understood, although it is assumed that sex hormones play a role. Disrupted sex hormone action is also believed to be involved in the increased occurrence of genital abnormalities among newborn boys and precocious puberty in girls. In this article, recent literature on sex steroid levels and their physiological roles during childhood is reviewed. It is concluded that (i) circulating levels of estradiol in prepubertal children are lower than originally claimed; (ii) children are extremely sensitive to estradiol and may respond with increased growth and/or breast development even at serum levels below the current detection limits; (iii) no threshold has been established, below which no hormonal effects can be seen in children exposed to exogenous steroids or endocrine disruptors; (iv) changes in hormone levels during fetal and prepubertal development may have severe effects in adult life and (v) the daily production rates of sex steroids in children estimated by the Food and Drug Administration in 1999 and still used in risk assessments are highly overestimated and should be revised. Because no lower threshold for estrogenic action has been established, caution should be taken to avoid unnecessary exposure of fetuses and children to exogenous sex steroids and endocrine disruptors, even at very low levels.

Aksglaede, Lise; Juul, Anders

2006-01-01

46

The influence of gender and sex steroids on craniofacial nociception.  

Science.gov (United States)

Several pain conditions localized to the craniofacial region show a remarkable sex-related difference in their prevalence. These conditions include temporomandibular disorders and burning mouth syndrome as well as tension-type, migraine, and cluster headaches. The mechanisms that underlie sex-related differences in the prevalence of these craniofacial pain conditions remain obscure and likely involve both physiological and psychosocial factors. In terms of physiological factors relevant to the development of headache, direct evidence of sex-related differences in the properties of dural afferent fibers or durally activated second-order trigeminal sensory neurons has yet to be provided. There is, however, evidence for sex-related differences in the response properties of afferent fibers and second-order trigeminal sensory neurons that convey nociceptive input from other craniofacial tissues associated with sex-related differences in chronic pain conditions, such as those that innervate the masseter muscle and temporomandibular joint. Further, modulation of craniofacial nociceptive input by opioidergic receptor mechanisms appears to be dependent on biological sex. Research into mechanisms that may contribute to sex-related differences in trigeminal nociceptive processing has primarily focused on effect of the female sex hormone estrogen, which appears to alter the excitability of trigeminal afferent fibers and sensory neurons to noxious stimulation of craniofacial tissues. This article discusses current knowledge of potential physiological mechanisms that could contribute to sex-related differences in certain craniofacial pain conditions. PMID:17300382

Cairns, Brian E

2007-02-01

47

Steroid hormones, receptors, and perceptual and cognitive sex differences in the visual system.  

Science.gov (United States)

The actions of gonadal steroid hormones induce morphological sex differences in many tissues in the body, including brain. These occur either during development to organize tissues in a sex-specific pattern and/or in adulthood to activate specific cellular pathways. Cellular and morphological changes in the brain, induced by androgens and estrogens, underlie behavioral sex differences in both reproductive and non-reproductive behaviors, including visual perception. A growing body of evidence indicates that some sex differences related to visual perception arise as the result of the organizational actions of gonadal steroid hormones on cerebral cortical pathways involved in visual processing of objects and movement. This review addresses the influence of gonadal steroids on structural, biochemical and morphological changes in tissues in the brain and body. These effects are extended to consider how gonadal hormone effects may contribute to cognitive sex differences across species that are related to processing within the dorsal and ventral visual streams for motion and objects, respectively. Lastly, this review considers the question of how cognitive sex differences related to processing of movement and objects in humans may be reflective of two types of cognitive style that are only superficially related to gender. PMID:25153712

Handa, Robert J; McGivern, Robert F

2015-02-01

48

Secondary osteoporosis due to sickle cell anemia: Do sex steroids play a role?  

Directory of Open Access Journals (Sweden)

Full Text Available Background : The exact cause of osteoporosis in patients with sickle cell disease (SCD is not known, and various hypotheses have been put forward. Aim: To assess the effect of sex steroids on bone mass in SCD patients. Settings and Design: In King Fahd Hospital of the university, Alkhobar, Saudi Arabia, a cross-sectional study was carried out. Materials and Methods : All patients known to suffer from SCD attending the hospital between August 2006 and August 2007 were subjects of the study. Blood was extracted for serum level of androgens, gonadotropins, thyroid stimulating hormone (TSH, calcium, phosphorus, and alkaline phosphatase. Measurement of bone mineral density (BMD of hip and spine was done using dual-energy X-ray absorptiometry (DEXA. All tests were performed using SPSS (Statistical Package for Social Sciences, version 14.0, Chicago, Illinois, with P value of < 0.05 being statistically significant with confidence interval (CI of 95%. Results : One hundred three consecutive patients with an average age of 27.83 years were studied. Forty-five were males; and 58, females. Low bone mass (osteoporotic/osteopenic was found in 62.2% of the patients in the male group and 67.06% in the female group. In males, testosterone level was not significant between different groups, but total estradiol levels were significantly lower in the osteopenic and osteoporotic patients (P < 0.003 and < 0.01 respectively. In female patients, estradiol and testosterone levels were lower in osteoporotic patients in comparison to non-osteoporotic patients (P = 0.05 and 0.001. Conclusions : Our study indicates that sex steroids play a major role in the development of osteopenia and osteoporosis in patients with SCD

Sadat-Ali Mir

2008-05-01

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New insights into the role of sex steroid hormones in pregnancy: possible therapeutic approach by sex steroid hormones for the treatment of both preeclampsia and preterm labor.  

Science.gov (United States)

Fetal peptide hormones are essential for the development of fetus, which increase in accordance with pregnancy term. Concentration of these hormones within the feto-placental unit is normally higher than that of maternal circulation. Since these hormones are biologically active, the leakage of these hormones into the maternal circulation is regulated by degradation activity by placental aminopeptidases, in order to maintain the balance between carriage of pregnancy and onset of labor.Because the concentration of these hormones, being regulated by the amount of endogenous production and by physiological degradation by enzymes in the blood and tissue, the balance between production and degradation is a definitive element for maintaining normal gestation and term delivery.The changes of the balance between fetal angiotensin II (A-II) and vasopressin (AVP) andA-II and AVP degrading enzymes, between aminopeptidase A (APA) and placental leucine aminopeptidase( P-LAP) - in the placenta and maternal blood due to fetal stress such as hypoxia - are the provable causes of preeclampsia or preterm labor.Induction of APA and P-LAP by estradiol benzoate (E2) and progesterone (P) from placenta has been demonstrated. They are involved in the regulation of fetal peptide hormones via placental aminopeptidases in homeostasis of pregnancy.Recently it was shown that both APA and P-LAP could be potentially safe and effective drugs for preeclampsia and preterm labor. The authors' proposed sex steroid treatment with dose increasing manner by gestational week (sex steroid treatment) for severe preeclampsia and preterm labor could be candidates replacing conventional treatments. In light of lacking safe and effective medication, the proposed sex steroid treatment is worthwhile for the prospective controlled studies for the treatment of both preeclampsia and preterm labor. PMID:25658663

Mizutani, S; Mizutani, E

2015-03-01

50

Sex steroid hormones modulate responses to social challenge and opportunity in males of the monogamous convict cichlid, Amatitliana nigrofasciata.  

Science.gov (United States)

Steroid hormones play an important role in modulating behavioral responses to various social stimuli. It has been suggested that variation in the hormonal regulation of behavior across species is associated with social organization and/or mating system. In order to further elucidate the interplay of hormones and behavior in social situations, we exposed males of the monogamous convict cichlid Amatitliana nigrofasciata to three social stimuli: gravid female, intruder male, and a nonsocial stimulus. We used a repeated measure design to create behavioral profiles and explore how sex steroid hormones respond to and regulate social behavior. Results show distinct behavioral responses to different social situations, with circulating 11-ketotestosterone increasing in response to social stimuli. Pharmacological manipulations using specific androgen and estrogen receptor agonists and antagonists exposed complex control over digging behavior in the social opportunity context. In the social challenge context, aggressive behaviors decreased in response to blocking the androgen receptor pathway. Our results extend our understanding of sex steroid regulation of behavioral responses to social stimulation. PMID:23651580

Sessa, Anna K; Harris, Rayna M; Hofmann, Hans A

2013-08-01

51

Social environment and steroid hormones affect species and sex differences in immune function among voles.  

Science.gov (United States)

Testosterone has bipotential effects on male fitness; that is, it both suppresses immune function and maintains characteristics important for reproductive success. Presumably, these effects of testosterone may be more pronounced among polygynous species because testosterone concentrations are generally higher among polygynous than monogamous males. The present study examined sex and species differences in cell-mediated immunity among four arvicoline rodents. The role of mating system and sex steroids in sex differences in immune function was examined in individually housed polygynous meadow (Microtus pennsylvanicus) and montane (M. montanus) voles and monogamous prairie (M. ochrogaster) and pine (M. pinetorum) voles in Experiment 1. No sex differences in splenocyte proliferation were observed among the four species and circulating testosterone concentrations did not correlate with immune function of individuals within each species. The contribution of social isolation to these results was examined in Experiment 2, in which meadow and prairie voles were housed individually, or with same- or opposite-sex conspecifics in either pairs or groups of four per cage for 28 days. Overall, prairie voles exhibited more robust immune responses than meadow voles when housed in pairs or in same-sex groups. Sex differences in immune function were also apparent; male meadow voles had higher immune responses than female conspecifics when housed in pairs, whereas female prairie voles had higher responses than male conspecifics when housed in same-sex pairs. Circulating sex steroid hormones and corticosterone appear to mediate some, but not all, of the changes in immune function evoked by differential housing conditions. Taken together, these results suggest that social factors have significant effects on immunity and should be considered in studies of sex differences in immunity at both proximate and ultimate levels. PMID:9344689

Klein, S L; Hairston, J E; Devries, A C; Nelson, R J

1997-08-01

52

Postmenopausal serum sex steroids and risk of hormone receptor positive and negative breast cancer: a nested case-control study  

DEFF Research Database (Denmark)

Pre-diagnostic endogenous sex steroid hormone levels have well established associations with overall risk of breast cancer. While evidence towards the existence of distinct subtypes of breast cancer accumulates, few studies have investigated the associations of sex steroid hormone levels with risk of hormone receptor (estrogen (ER) and/or progesterone receptor (PR)) defined breast cancer. In a case-control study nested within the EPIC cohort (European Prospective Investigation into Cancer and Nutrition), estradiol, testosterone and sex hormone binding globulin levels were measured in pre-diagnostic serum samples from postmenopausal women not using HRT at blood donation. 554 women who developed invasive breast cancer with information on receptor status were matched with 821 control subjects. Conditional logistic regression models estimated breast cancer risk with hormone concentrations according to hormone receptor status of the tumor. Sex steroid hormones were associated with risks of not only ER+PR+ breast cancer [estradiol OR for highest versus lowest tertile=2.91 (95%CI:1.62-5.23), Ptrend0.002; testosterone OR=2.27 (95%CI:1.35-3.81), Ptrend=0.002] but also of ER-PR- breast cancer [estradiol OR=2.11 (95%CI:1.00-4.46), Ptrend =0.05; testosterone OR= 2.06 (95%CI:0.95-4.46), Ptrend=0.03], with associations appearing somewhat stronger in the receptor positive disease. Serum androgens and estrogens are associated with risks of both hormone receptor negative as well as receptor positive breast tumors. Further research is needed to establish through which molecular pathways, and during which evolutionary stages of development, androgens and estrogens can promote the occurrence of both receptor-positive and -negative clinical breast tumors.

James, Rebecca E.; Lukanova, Annekatrin

2011-01-01

53

Skeletal muscle and bone: effect of sex steroids and aging  

Science.gov (United States)

Both estrogen and testosterone are present in males and females. Both hormones contribute to the well being of skeletal muscle and bone in men and women, and there is evidence that the loss of sex hormones is associated with the age-related decline in bone and skeletal muscle mass. Hormonal supplementation of older adults to restore estrogen and testosterone levels to those of young men and women is not without penalty.

PhD Marybeth Brown (University of Missouri-Columbia Dept of Physical Therapy)

2008-02-14

54

[Testosterone, albumin and sex steroid-binding globulin in the blood serum of patients with laryngeal cancer].  

Science.gov (United States)

Since endocrine factors play a role in the etiology and pathogenesis of precancerous and tumor diseases of the pharynx, the study was concerned with assays of total testosterone, albumin, sex steroid-binding globulin and free and protein-bound androgens in the blood serum of patients with malignant and benign tumors of the larynx. Laryngeal cancer patients revealed raised levels of total, free and albumin-bound testosterone matched by a lower concentration of sex steroid-binding globulin. Maximum differences between the study groups were established in the relationship between the fraction of testosterone associated with sex steroid-binding globulin and that of free androgen. An important role of androgens in the pathogenesis of laryngeal cancer was inferred. Further studies of androgen secretion and transport by blood proteins in laryngeal cancer patients are essential for the investigations of pathways of sex steroid hormones action. PMID:4041091

Kushlinski?, N E; Bassalyk, L S; Alferov, V S; Ogol'tsova, E S; Savinskaia, A P

1985-01-01

55

Hyperostosis frontalis interna: archaeological evidence of possible microevolution of human sex steroids?  

Science.gov (United States)

Hyperostosis frontalis interna is a restricted bilateral thickening of the frontal endocranial surface, which is frequently found in postmenopausal females today. Surprisingly, this condition had a higher male prevalence in its rare archaeological records. This is again highlighted by the oldest known male European hyperostosis frontalis interna case in an adult Celtic from 100 BC presented here. This unique specimen supports earlier suggestions of the possible microevolution of human endocrine regulation, e.g. by sex steroids, and its pathoanatomical impact. PMID:15553271

Rühli, F J; Böni, T; Henneberg, M

2004-01-01

56

Short fused? associations between white matter connections, sex steroids, and aggression across adolescence.  

Science.gov (United States)

Functional neuroimaging studies in adults show that aggression involves reduced brain communication between subcortical and cortical areas dedicated to motivation and control, respectively. Prior research indicates that sex steroid hormone production during adolescence negatively influences the rapid development of white matter connectivity between subcortical and cortical areas during adolescence and may potentiate aggression. Here, we tested this hypothesis in 258 participants between 8 and 25 years of age by using Diffusion Weighted Imaging to examine the microstructure of white matter connections within the fronto-temporal-subcortical network. Trait aggression was measured using the Buss Perry Aggression Questionnaire and testosterone and estradiol levels were measured in saliva. Results indicated that higher levels of testosterone were associated with less white matter integrity within the fronto-temporal-subcortical network (i.e., higher mean diffusivity [MD] longitudinal [LD], and radial diffusivity [RD]). Furthermore, lower fractional anisotropy and higher MD, LD, and RD values within this network increased expressive forms of aggression and reduced inhibited forms of aggression (hostility). Our study indicates higher levels of testosterone relating to lower quality of structural cortical-subcortical connectivity, arguably resulting in a shift from inhibited towards expressive forms of aggression. Our data adds evidence to the idea that aggressive tendencies are subcortically driven, but individuals with relatively high testosterone might have lower structural connectivity within cortical control areas, resulting in a stronger tendency to act on these aggressive tendencies. PMID:25359710

Peper, Jiska S; de Reus, Marcel A; van den Heuvel, Martijn P; Schutter, Dennis J L G

2015-03-01

57

Sex steroid hormones modulate the activation of murine peritoneal macrophages: receptor mediated modulation.  

Science.gov (United States)

The comparative dose and time-dependent effects of male and female sex steroid hormones on nitrite release by murine peritoneal macrophages (M phi) stimulated by LPS were studied. M phi from gonadectomized mice released larger amounts of nitrite on LPS stimulation than controls; although nitrite release was significantly greater in castrated males than in ovariectomized females, suggesting that sex hormone deprivation results in an increase in nitrite release. This was further confirmed by in vitro treatment of M phi with estradiol (E2), testosterone (T) and progesterone (P) at different doses and duration prior to, and during, stimulation of nitrite production by LPS. E2 (except at 10(-2) ng/ml), T and P significantly (P < 0.05) suppressed the nitrite release in a dose-dependent manner. Nitrite release from M phi increased with decreasing exposure time to E2, T and P. Preincubation of M phi with sex hormones prior to LPS treatment also reduced nitrite production. Sex steroid receptor antagonists tamoxifen citrate, cyproterone acetate/flutamide and RU486 markedly reduced the inhibitory effect of E2, T and P, respectively, suggesting that sex hormones modulate M phi nitrite release via a receptor-mediated system. PMID:9669089

Savita; Rai, U

1998-02-01

58

Endogenous sex steroids and risk of cervical carcinoma: results from the EPIC study  

DEFF Research Database (Denmark)

BACKGROUND: Epidemiological data and animal models suggest that, despite the predominant role of human papillomavirus infection, sex steroid hormones are also involved in the etiology of invasive cervical carcinoma (ICC).METHODS: 99 ICC cases, 121 cervical intraepithelial neoplasia grade 3 (CIN3) cases and 2 control women matched with each case for center, age, menopausal status and blood collection-related variables, were identified in the EPIC study. Circulating levels of testosterone (T) and estradiol (E2); dehydroepiandrosterone sulfate (DHEAS); progesterone (pre-menopausal women); and sex hormone binding globulin (SHBG) were measured using immunoassays. Levels of free (f) T and E2 were calculated from absolute concentrations of T, E2 and SHBG. Odds ratios (OR) and 95% confidence intervals (CI) were computed using regularized conditional logistic regression. RESULTS: Among pre-menopausal women, associations with ICC were observed for fT (OR for highest vs lowest tertile=5.16, 95% CI: 1.50-20.1). SHBG level was associated with a significant downward trend in ICC risk. T, E2, fE2 and DHEAS showed non significant positive association with ICC. Progesterone was uninfluential. Among post-menopausal women, associations with ICC were found for T (OR=3.14; 95% CI: 1.21-9.37), whereas E2, and fT showed non significant positive association. SHBG level was unrelated to ICC risk in post-menopausal women. No associations between any hormone and CIN3 were detected in either pre- or post-menopausal women.CONCLUSIONS: Our findings suggest for the first time that T and possibly E2 may be involved in the etiology of ICC.Impact:The responsiveness of cervical tumors to hormone modulators is worth exploring.

Rinaldi, Sabina; Plummer, Martyn

2011-01-01

59

Bone turnover markers in patients with prostate carcinoma: influence of sex steroids levels.  

Science.gov (United States)

There are limited data about bone turnover markers (BTM) in androgen deprivation therapy (ADT)-treated prostate cancer (PCa) patients, and the relationship between sex steroids, bone mass, and BTM has not been explored. Our objective was to analyze the influence of sex steroids levels on BTM in patients with PCa treated with or without ADT. We performed a cross-sectional study including 83 subjects with PCa (54% with ADT). BTM, bone mineral density (BMD), and sex steroids were determined. BTM were inversely related to serum level of estrogens. Tartrate-specific acid phosphatase (TRAP-5b) showed a negative correlation with free estradiol (Free E) (r = -0.274, p = 0.014) and Bio E (r = -0.256, p = 0.022) that remained after adjustment for age: Free E (? = -0.241, p = 0.03) and Bio E (? = -0.213, p = 0.063). Bone-specific alkaline phosphatase (BSAP) concentrations were inversely related to Free E (r = -0.281, p = 0.011, age-adjusted ? = -0.256, p = 0.024). There was a negative correlation between osteocalcin (OC) levels and Free E (r = -0.195, p = 0.082; age-adjusted ? = -0.203, p = 0.076) and Bio E (r = -0.215, p = 0.054; age-adjusted ? = -0.240, p = 0.039). BTM and androgens were inversely related to TRAP-5b: total testosterone (total T) (r = -0.238, p = 0.033), Free T (r = -0.309, p = 0.05), and Bio T (r = -0.310, p = 0.05), but these correlations disappeared after age-adjustment. We did not find any relationship between BMD at different locations and sex steroids. In conclusion, in patients with PCa, estrogen levels influence bone resorption and bone formation whereas androgens may exert actions only in bone resorption. These results suggest that estradiol is the main sex steroid that regulates bone metabolism in males with prostate carcinoma. PMID:23640678

Varsavsky, Mariela; Reyes-García, Rebeca; García-Martín, Antonia; Rozas-Moreno, Pedro; González-Ramírez, Rocío; Rocío, González-Ramírez; Muñoz-Torres, Manuel

2014-01-01

60

Annual sex steroid profiles and effects of gender and season on cytochrome P450 mRNA induction in Atlantic tomcod (Microgadus tomcod)  

Energy Technology Data Exchange (ETDEWEB)

As a preliminary step in a 4-year biomonitoring program, sex steroid levels, gonad weights, and diameter of vitellogenic oocytes were measured in tomcod collected bimonthly from the Miramichi and Kouchibouguac rivers from September 1993 to September 1994. As well as the reproductive indices, hepatic levels of cytochrome P4501A mRNA (CYP1A mRNA) were also measured. The preparatory period for spawning began in September, with maximal steroid levels in November, and spawning took place from late December to January. The CYP1A mRNA levels in female tomcod appeared inversely related to plasma steroids, with the lowest amounts of CYP1A mRNA coinciding with maximal steroids. The CYP1A mRNA levels in male tomcod did not exhibit this relationship. River-river comparisons of female tomcod showed significantly smaller vitellogenic oocytes in the Miramichi, along with lower plasma testosterone, estradiol, and relative gonad weight. Miramichi CYP1A mRNA levels were higher than Kouchibouguac in the fall but lower in the spring sample. The CYP1A mRNA-sex steroid relationship observed in this study will facilitate meaningful interpretation of data collected during the full 4-year study.

Williams, P.J.; Courtenay, S.C. [Dept. of Fisheries and Oceans, New Brunswick (Canada); Wilson, C.E. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Ocean Sciences Center

1998-08-01

61

Sex steroids do not affect muscle weight, oxidative metabolism or cytosolic androgen reception binding of functionally overloaded rat Plantaris muscles  

Science.gov (United States)

The effects of sex steroids on muscle weight and oxidative capacity of rat planaris muscles subjected to functional overload by removal of synergistic muscles were investigated. Ten weeks after bilateral synergist removal, plantaris muscles were significantly hypertrophic compared with unoperated controls. After this period, the ability of the muscles to oxide three substrates of oxidative metabolism was assessed. Experimental procedures are discussed and results are presented herein. Results suggest a lack of beneficial effect of sex hormone status on the process of hypertrophy and on biochemical changes in overloaded muscle. Such findings are not consistent with the idea of synergistic effects of sex steroids and muscle usage.

Max, S. R.; Rance, N.

1983-01-01

62

Intracellular distribution and biological effects of phytochemicals in a sex steroid- sensitive model of human prostate adenocarcinoma.  

Science.gov (United States)

Prostate function is critical for male fertility and its well-known oncological biomarker, namely Prostate-Specific Antigen (PSA), can be also used to monitor prostate epithelial human cells upon treatment with pharmaceutical drugs or natural bioactive compounds. The LNCaP human prostate cell line was previously set up as a model system to investigate chemicals affecting prostate epithelium functionality by means of a tiered approach integrating two different toxicological endpoints, cell viability (MTS) and PSA secretion assays. Here, the same approach has been used to characterize the biological effects of phytochemicals on prostate epithelium. The antiandrogenic ability of phytochemicals to inhibit DHT-induced PSA secretion has been investigated also characterizing their intracellular distribution, in the presence or absence of sex steroids. Intracellular distribution allows to verify whether and to which extent each phytochemical is able to enter the cell and to reach the nucleus, the latter being the target of the supposed transcriptional modulatory activity upon phytochemicals' binding to sex steroid receptors. Some phytochemicals, supposed to have a role in the functionality of the prostate epithelium, have been tested in a dose-dependent manner in both MTS and PSA secretion assays. In parallel, to establish the "effective concentration", in comparison to the "nominal one", the intracellular amount of each phytochemical has been assessed upon cell fractionation of LNCaP-treated cells and subsequent chromatographic measurements. PMID:24962071

Smeriglio, Antonella; Trombetta, Domenico; Marcoccia, Daniele; Narciso, Laura; Mantovani, Alberto; Lorenzetti, Stefano

2014-01-01

63

Sex steroid levels in urine of cattle of different ages: evaluation of abuse control procedures.  

Science.gov (United States)

Levels of several natural urinary steroids have been determined in the urine of a large number of animals of different cattle categories in the context of steroid abuse in beef production. Bovine animals of different breeds, sex and age included in the Slovene national residue detection plan for steroid abuse were studied. Urine from 120 males and 174 females was analysed. Urinary boldenone, boldione, androstenedione, equiline, medroxyprogesterone, medroxyprogesterone acetate, melengestrol acetate, progesterone, stanozolol, trenbolone, trenbolone acetate, 17?-ethinylestradiol, 17?-methyltestosterone, epitestosterone, 17?-estradiol, testosterone, and nandrolone were determined by LC-MS/MS. Epitestosterone was found in all bulls; while the proportion of animals containing testosterone and androstenedione increased with age. Testosterone was not detected in bulls less than 5 months of age. Epitestosterone levels, however, were not age dependent. The ratio of testosterone to epitestosterone thus increased with age, from 0.13 ± 0.09 at 1-7 months to 0.42 ± 0.10 at 25-38 months. It was significantly (p < 0.01) higher in bulls above 13 months than in younger animals. In contrast to males, no urinary testosterone was found in females, whereas epitestosterone, androstenedione, progesterone and estradiol were present. The proportion of animals of various age groups in which epitestosterone was detected ranged from 68% to 100%, but the differences were not significant. The presence of both estradiol and progesterone in the same sample was not observed in any animal. The results of this study could be helpful in determining physiological urinary steroid levels in order to provide a baseline for the control of steroid abuse in beef production. PMID:24405322

Snoj, Tomaz; Dolenc, Jozica; Kobal, Silvestra

2014-04-01

64

Anabolic Steroids  

Science.gov (United States)

... steroids are manmade substances related to testosterone (male sex hormone). Doctors use anabolic steroids to treat hormone problems ... Methamphetamine (Meth) Prescription Depressant Medications Prescription Drugs Prescription Pain ... Stimulant Medications (Amphetamines) Salvia Spice ...

65

The growth hormone response to hexarelin in children: reproducibility and effect of sex steroids.  

OpenAIRE

We studied the variability of the GH response to the synthetic hexapeptide hexarelin (Hex) and the effect of sex steroids on the GH-releasing effect of Hex in a group of prepubertal short normal children. Twenty-five children were tested on two occasions 3-7 days apart with 2 micrograms/kg, i.v., Hex. The GH response to Hex was reevaluated after testosterone (T) administration in 10 boys, after ethinyl estradiol (EE) administration in 15 children (5 boys and 10 girls), and after oxandrolone (...

Ghigo, Ezio

1997-01-01

66

Steroid Signaling within Drosophila Ovarian Epithelial Cells Sex-Specifically Modulates Early Germ Cell Development and Meiotic Entry  

OpenAIRE

Drosophila adult females but not males contain high levels of the steroid hormone ecdysone, however, the roles played by steroid signaling during Drosophila gametogenesis remain poorly understood. Drosophila germ cells in both sexes initially follow a similar pathway. After germline stem cells are established, their daughters form interconnected cysts surrounded by somatic escort (female) or cyst (male) cells and enter meiosis. Subsequently, female cysts acquire a new covering of somatic cell...

Morris, Lucy X.; Spradling, Allan C.

2012-01-01

67

Modelling the binding affinity of steroids to zebrafish sex hormone-binding globulin.  

Science.gov (United States)

The circulating endogenous steroids are transported in the bloodstream. These are bound to a highly specific sex hormone-binding globulin (SHBG) and in lower affinity to proteins such as the corticosteroid-binding protein and albumin in vertebrates, including fish. It is generally believed that the glycoprotein SHBG protects these steroids from rapid metabolic degradation and thus intervenes in its availability at the target tissues. Endocrine disrupters binding to SHBG affect the normal activity of natural steroids. Since xenobiotics are primarily released in the aquatic environment, there is a need to evaluate the binding affinity of xenosteroid mimics on fish SHBG, especially in zebrafish (Danio rerio), a small freshwater fish originating in India and widely employed in ecotoxicology, toxicology, and genetics. In this context, a zebrafish SHBG (zfSHBG) homology model was developed using the human SHBG (hSHBG) receptor structure as template. It was shown that interactions with amino acids Ser-36, Asp-59 and Thr-54 were important for binding affinity. A ligand-based pharmacophore model was also developed for both zfSHBG and hSHBG inhibitors that differentiated binders from non-binders, but also demonstrated structural requirements for zfSHBG and hSHBG ligands. The study provides insights into the mechanism of action of endocrine disruptors in zebrafish as well as providing a useful tool for identifying anthropogenic compounds inhibiting zfSHBG. PMID:24874994

Saxena, A K; Devillers, J; Pery, A R R; Beaudouin, R; Balaramnavar, V M; Ahmed, S

2014-01-01

68

Male-to-female transsexuals show sex-atypical hypothalamus activation when smelling odorous steroids.  

Science.gov (United States)

One working hypothesis behind transsexuality is that the normal sex differentiation of certain hypothalamic networks is altered. We tested this hypothesis by investigating the pattern of cerebral activation in 12 nonhomosexual male-to-female transsexuals (MFTRs) when smelling 4,16-androstadien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST). These steroids are reported to activate the hypothalamic networks in a sex-differentiated way. Like in female controls the hypothalamus in MFTRs activated with AND, whereas smelling of EST engaged the amygdala and piriform cortex. Male controls, on the other hand, activated the hypothalamus with EST. However, when restricting the volume of interest to the hypothalamus activation was detected in MFTR also with EST, and explorative conjunctional analysis revealed that MFTR shared a hypothalamic cluster with women when smelling AND, and with men when smelling EST. Because the EST effect was limited, MFTR differed significantly only from male controls, and only for EST-AIR and EST-AND. These data suggest a pattern of activation away from the biological sex, occupying an intermediate position with predominantly female-like features. Because our MFTRs were nonhomosexual, the results are unlikely to be an effect of sexual practice. Instead, the data implicate that transsexuality may be associated with sex-atypical physiological responses in specific hypothalamic circuits, possibly as a consequence of a variant neuronal differentiation. PMID:18056697

Berglund, H; Lindström, P; Dhejne-Helmy, C; Savic, I

2008-08-01

69

Crystal structure of human sex hormone-binding globulin: steroid transport by a laminin G-like domain  

OpenAIRE

Human sex hormone-binding globulin (SHBG) transports sex steroids in blood and regulates their access to target tissues. In biological fluids, SHBG exists as a homodimer and each monomer comprises two laminin G-like domains (G domains). The crystal structure of the N–terminal G domain of SHBG in complex with 5?–dihydrotestosterone at 1.55 ? resolution reveals both the architecture of the steroid-binding site and the quaternary structure of the dimer. We also show that G domains have je...

Grishkovskaya, Irina; Avvakumov, George V.; Sklenar, Gisela; Dales, David; Hammond, Geoffrey L.; Muller, Yves A.

2000-01-01

70

A genome-wide association meta-analysis of circulating sex hormone-binding globulin reveals multiple Loci implicated in sex steroid hormone regulation.  

OpenAIRE

Sex hormone-binding globulin (SHBG) is a glycoprotein responsible for the transport and biologic availability of sex steroid hormones, primarily testosterone and estradiol. SHBG has been associated with chronic diseases including type 2 diabetes (T2D) and with hormone-sensitive cancers such as breast and prostate cancer. We performed a genome-wide association study (GWAS) meta-analysis of 21,791 individuals from 10 epidemiologic studies and validated these findings in 7,046 individuals in an ...

Coviello, Ad; Haring, R.; Wellons, M.; Vaidya, D.; Lehtima?ki, T.; Keildson, S.; Lunetta, Kl; He, C.; Fornage, M.; Lagou, V.; Mangino, M.; Onland-moret, Nc; Chen, B.; Eriksson, J.; Garcia, M.

2012-01-01

71

A genome-wide association meta-analysis of circulating sex hormone-binding globulin reveals multiple loci implicated in sex steroid hormone regulation  

OpenAIRE

Sex hormone-binding globulin (SHBG) is a glycoprotein responsible for the transport and biologic availability of sex steroid hormones, primarily testosterone and estradiol. SHBG has been associated with chronic diseases including type 2 diabetes (T2D) and with hormone-sensitive cancers such as breast and prostate cancer. We performed a genome-wide association study (GWAS) meta-analysis of 21,791 individuals from 10 epidemiologic studies and validated these findings in 7,046 individuals in an ...

Coviello, Andrea D.; Haring, Robin; Wellons, Melissa; Vaidya, Dhananjay; Lehtimaki, Terho; Keildson, Sarah; Lunetta, Kathryn L.; He, Chunyan; Fornage, Myriam; Lagou, Vasiliki; Mangino, Massimo; Onland-moret, N. Charlotte; Chen, Brian; Eriksson, Joel; Garcia, Melissa

2012-01-01

72

Intramuscular sex steroid hormones are associated with skeletal muscle strength and power in women with different hormonal status.  

Science.gov (United States)

Estrogen (E2 )-responsive peripheral tissues, such as skeletal muscle, may suffer from hormone deficiency after menopause potentially contributing to the aging of muscle. However, recently E2 was shown to be synthesized by muscle and its systemic and intramuscular hormone levels are unequal. The objective of the study was to examine the association between intramuscular steroid hormones and muscle characteristics in premenopausal women (n = 8) and in postmenopausal monozygotic twin sister pairs (n = 16 co-twins from eight pairs) discordant for the use of E2 -based hormone replacement. Isometric skeletal muscle strength was assessed by measuring knee extension strength. Explosive lower body muscle power was assessed as vertical jump height. Due to sequential nature of enzymatic conversion of biologically inactive dehydroepiandrosterone (DHEA) to testosterone (T) and subsequently to E2 or dihydrotestosterone (DHT), separate linear regression models were used to estimate the association of each hormone with muscle characteristics. Intramuscular E2 , T, DHT, and DHEA proved to be significant, independent predictors of strength and power explaining 59-64% of the variation in knee extension strength and 80-83% of the variation of vertical jumping height in women (P statistics used took into account the lack of statistical independence of twin sisters. Furthermore, muscle cells were shown to take up and actively synthesize hormones. Present study suggests intramuscular sex steroids to associate with strength and power regulation in female muscle providing novel insight to the field of muscle aging. PMID:25645687

Pöllänen, Eija; Kangas, Reeta; Horttanainen, Mia; Niskala, Paula; Kaprio, Jaakko; Butler-Browne, Gillian; Mouly, Vincent; Sipilä, Sarianna; Kovanen, Vuokko

2015-04-01

73

Specific estrogen-binding protein of rat liver and sex steroid metabolism  

International Nuclear Information System (INIS)

Model experiments were conducted to study the effect of a highly purified preparation of specific estrogen-binding protein (SEBP) on the intensity of estradiol and testosterone metabolism under the influence of enzymes in liver homogenate from female rats, not containing SEBP. The liver of mature female rats was homogenized in two volumes of 50 mM Tris-HCl buffer, pH 7.5, containing 600 mg% of glucose. The tritium-steroid was preincubated for 15 min at 0-4 C with 0-4 microg of the preparation of SEBP (200 microl). A standard preparation of partially purified SEBP was obtained from liver cystosol of mature male rats; affinity chromatography on estradiolagarose was used. It is shown that SEBP can really take part in regulation of the dynamics of sex steroids in the liver. E1 did not affect the metabolic rate of H 3-E2 by liver homogenate from females, but caused marked acceleration of H 3-E2 metabolism by male liver homogenate

74

Enhanced Hematopoietic Stem Cell Function Mediates Immune Regeneration following Sex Steroid Blockade.  

Science.gov (United States)

Mechanisms underlying age-related defects within lymphoid-lineages remain poorly understood. We previously reported that sex steroid ablation (SSA) induced lymphoid rejuvenation and enhanced recovery from hematopoietic stem cell (HSC) transplantation (HSCT). We herein show that, mechanistically, SSA induces hematopoietic and lymphoid recovery by functionally enhancing both HSC self-renewal and propensity for lymphoid differentiation through intrinsic molecular changes. Our transcriptome analysis revealed further hematopoietic support through rejuvenation of the bone marrow (BM) microenvironment, with upregulation of key hematopoietic factors and master regulatory factors associated with aging such as Foxo1. These studies provide important cellular and molecular insights into understanding how SSA-induced regeneration of the hematopoietic compartment can underpin recovery of the immune system following damaging cytoablative treatments. These findings support a short-term strategy for clinical use of SSA to enhance the production of lymphoid cells and HSC engraftment, leading to improved outcomes in adult patients undergoing HSCT and immune depletion in general. PMID:25733018

Khong, Danika M; Dudakov, Jarrod A; Hammett, Maree V; Jurblum, Marc I; Khong, Sacha M L; Goldberg, Gabrielle L; Ueno, Tomoo; Spyroglou, Lisa; Young, Lauren F; van den Brink, Marcel R M; Boyd, Richard L; Chidgey, Ann P

2015-03-10

75

Morphological and functional features of the sex steroid-responsive posterodorsal medial amygdala of adult rats.  

Science.gov (United States)

The rat posterodorsal medial amygdala (MePD) expresses receptors for gonadal hormones and integrates sex steroid-sensitive subcortical networks. Male-female differences are found in the morphology, connectivity, and local neuropil structure of MePD. For example, dendritic spine density is sexually-dimorphic and changes with the estrous cycle and following gonadal hormones manipulations. Due to its connectivity, the MePD may affect emotionally-loaded social behaviors, according to a former Newman's seminal proposition. Unilateral fiber-sparing ibotenic acid damage of the MePD does not impair male sexual behavior. However, microinjecting glutamate and histamine into the right MePD facilitates ejaculation. Further, MePD-lesioned rats are not different from normal rats in anxiety-like behavior as evaluated by the elevated plus maze test or innate fear test induced by a live cat. In another study, an adapted model for inducing aggressive behavior in rats by a brief period of restraint prior to the resident-intruder paradigm was used to study Fos-immunoreactivity in the MePD. Following stressful stimulation (restraint) or the restraint and fight condition, but not after aggression alone, Fos-immunoreactivity was detected in the MePD. Microinjecting the inhibitory neuropeptide somatostatin into the right MePD notably reduces fighting behavior without affecting locomotion. Overall, these data indicate that sex steroids and local neurochemical stimulatory/inhibitory transmitters modulate the MePD and reinforce the idea that this area is a node for modulating social behavior neural networks. PMID:22827219

Rasia-Filho, A A; Haas, D; de Oliveira, A P; de Castilhos, J; Frey, R; Stein, D; Lazzari, V M; Back, F; Pires, G N; Pavesi, E; Winkelmann-Duarte, E C; Giovenardi, M

2012-10-01

76

Cardiovascular risk factors in men : The role of gonadal steroids and sex hormone-binding globulin  

DEFF Research Database (Denmark)

Males have higher risk of cardiovascular disease (CVD) than premenopausal females. Gonadal steroids are probably involved in the gender difference in CVD, but previous results have been conflicting. We investigated the associations between CVD risk factors and sex hormones in a cross-sectional designed study of 508 healthy males, aged 41 to 72 years. We determined total testosterone (T), sex hormone-binding globulin (SHBG), free androgen index (FAI), and estradiol (E2) and studied their relationship to body fat mass (BF), blood pressure (BP), aortic compliance, left ventricular mass (LVM), and plasma lipids (total cholesterol, high-density lipoprotein [HDL], low-density lipoprotein [LDL], very--low-density lipoprotein [VLDL], and triglycerides). In quartile analyses after adjustment for confounders (age, body mass index [BMI], alcohol consumption, and smoking), SHBG and E2 were positively associated with HDL, while FAI was negatively associated with HDL. T and SHBG were negatively associated with VLDL and triglycerides, while FAI was positively associated with VLDL and triglycerides. T and SHBG were negatively associated with BMI and BF, while FAI and E2 were positively associated with BMI and BF. E2 was negatively associated with LVM. No hormone varied with total cholesterol, LDL, BP, and aortic compliance in the adjusted analyses. In multiple regression analyses, SHBG was the main predictive variable of HDL, VLDL, and triglycerides explaining 12%, 17%, and 17% of the variation, respectively. No other hormones were selected as predictive variables for VLDL and triglycerides, but E2, T, and FAI were selected in the HDL regression, explaining 3%, 2%, and less than 1%, respectively. Our regression analyses illustrate the diverging results when investigating associations between gonadal steroids and lipids with and without SHBG adjustment. Atherogenic lipid profile in males is associated with low SHBG, low T levels, and a high FAI. Males with high E2 levels may have a less atherogenic lipid profile and lower LVM. SHBG is a key hormone in the association between sex hormones and plasma lipids. We suggest that conflicting results of cross-sectional and intervention studies of sex hormones and lipids, in part, may be explained by interindividual differences or changes in SHBG. Thus, further studies on the potential role of SHBG in the development of ischemic heart disease (IHD) should be performed.

Gyllenborg, J; Rasmussen, S L

2001-01-01

77

Effects of gonadal sex and incubation temperature on the ontogeny of gonadal steroid concentrations and secondary sex structures in leopard geckos, Eublepharis macularius.  

Science.gov (United States)

Incubation temperature during embryonic development determines gonadal sex in the leopard gecko (Eublepharis macularius). Incubation temperature and gonadal sex jointly influence the display of sexual and agonistic behavior in adult leopard geckos. These differences in adult behavior are organized prior to sexual maturity, and it is plausible that post-natal hormones influence neural and behavioral differentiation. Here we assessed incubation temperature and sex effects on sex steroid levels in leopard geckos at 2, 10, and 25 weeks of age and monitored the development of male secondary sex structures. Males had significantly higher androgen concentrations at all time points, whereas females had significantly higher 17beta-estradiol (E2) concentrations only at 10 and 25 weeks. Within males, age but not incubation temperature affected steroid levels and morphological development. Male androgen levels increased modestly by 10 and dramatically by 25 weeks of age, whereas E2 levels remained unchanged over this period. Most males had signs of hemipenes at 10 weeks of age, and all males had hemipenes and open preanal pores by 25 weeks of age. In females, age and incubation temperature affected E2 and dihydrotestosterone (DHT) but not T concentrations. Controlling for age, females from 34 degrees C have higher DHT and lower E2 levels than females from 30 degrees C. Further, E2 concentrations increased significantly from 2 to 10 weeks, after which E2 levels remained steady. Together, these results indicate that sexually dimorphic levels of steroids play a major role in the development of leopard gecko behavior and morphology. Furthermore, these data suggest that the organizational effects of incubation temperature on adult female phenotype could be, in part, mediated by incubation temperature effects on steroid hormone levels during juvenile development. PMID:15935155

Rhen, Turk; Sakata, Jon T; Crews, David

2005-07-01

78

Anatomical distribution of sex steroid hormone receptors in the brain of female medaka.  

Science.gov (United States)

Estrogen and androgen play crucial roles in coordinating reproductive functions through estrogen receptors (ERs) and androgen receptors (ARs), respectively. These receptors are considered important for regulation of the hypothalamo-pituitary-gonadal (HPG) axis. Despite their biological importance, the distribution of sex steroid receptors has not been fully analyzed anatomically in the teleost brain. The teleosts have many characteristic features, which allow unique approaches toward an understanding of the regulatory mechanisms of reproductive functions. Medaka serves as a good model system for studying the mechanisms by which steroid receptor-mediated systems are regulated, because (1) their breeding conditions can be easily manipulated; (2) we can take advantage of the genome database; and 3) molecular genetic tools, such as transgenic techniques, are applicable. We analyzed the distribution of ER?, ER?1, ER?2, AR?, and AR? mRNA by in situ hybridization in the brain of female medaka. We found that all subtypes of ERs and ARs were expressed in the following nuclei: the dorsal part of the ventral telencephalic area (Vd), supracommissural part of the ventral telencephalic area (Vs), postcommissural part of the ventral telencephalic area (Vp), preoptic area (POA), and nucleus ventralis tuberis (NVT). These regions are known to be involved in the regulation of sexual behavior (Vd, Vs, Vp, POA) or the HPG axis (NVT). These ER- and/or AR-expressing neurons may regulate sexual behavior or the HPG axis according to their axonal projections. Future analysis should be targeted to the neurons described in the present study to extend our understanding of the central regulatory mechanisms of reproduction. PMID:23124931

Zempo, Buntaro; Kanda, Shinji; Okubo, Kataaki; Akazome, Yasuhisa; Oka, Yoshitaka

2013-06-01

79

Binding of xenoestrogens to the sex steroid-binding protein in plasma from Arctic charr (Salvelinus alpinus L.).  

Science.gov (United States)

A specific sex steroid-binding protein (SBP) is believed to be involved in regulation of circulating sex steroids, steroid delivery to target cells and intracellular signalling in sex steroid-sensitive tissues. In the present work, interactions between xenoestrogens and the plasma SBP in Arctic charr (Salvelinus alpinus L.) were determined using ligand-protein binding studies. The test compounds were all able to displace tritiated 17 beta-estradiol (E2) from the Arctic charr SBP (acSBP) in a competitive and dose-dependent manner. The acSBP affinities for the xenoestrogens ranged over several orders of magnitude (17 beta-estradiol>ethynylestradiol (EE2)>zearalenone (ZEA)>diethylstilbestrol (DES)>genistein (GEN)>bisphenol A (BPA), 4-t-octylphenol (OP)>o,p'-DDT, and dieldrin (DIN)), but were consistently lower than that of 17 beta-estradiol (about 4 x 10(2) -10(6)-fold less potent). The relative binding affinity (RBA) for selected chemicals were independent of both gender, age and maturation status, as well as variations of acSBP binding affinity. The affinity of endogenous steroids and estrogen mimics for the acSBP shows a high correlation to the affinity for the rainbow trout SBP, thus suggesting a phylogenetically conserved ligand-binding site between closely related species. Furthermore, it is argued that interaction with the acSBP- and SBP-mediated processes may introduce novel pathways for endocrine disruption, which may work in concert with the classical receptor-mediated effects. PMID:15556074

Tollefsen, K-E; Ovrevik, J; Stenersen, J

2004-10-01

80

Disparate changes in kisspeptin and neurokinin B expression in the arcuate nucleus after sex steroid manipulation reveal differential regulation of the two KNDy peptides in rats.  

Science.gov (United States)

Kisspeptin, neurokinin B (NKB) and dynorphin A are coexpressed in a population of neurons in the arcuate nucleus (ARC), termed KNDy neurons, which were recently recognized as important elements for the generation of GnRH pulses. However, the topographic distribution of these peptides and their regulated expression by sex steroids are still not well understood. In this study, detailed examination of NKB and kisspeptin immunoreactivity in the rat ARC was carried out, including comparison between sexes, with and without sex steroid replacement. Neurons expressing kisspeptin and NKB were more prominent in the caudal ARC of females, whereas neurons expressing NKB, but not kisspeptin, were the most abundant in the male. Sex steroid manipulation revealed differential regulation of kisspeptin and NKB; although kisspeptin immunoreactive (ir) cells increased in response to gonadectomy, NKB remained unchanged. Furthermore, the number of NKB-ir cells increased upon sex steroid replacement compared with gonadectomy, whereas kisspeptin did not, suggesting that sex steroids differently regulate these peptides. In addition, only in females did the density of kisspeptin- and NKB-ir fibers in the ARC increase upon sex steroid replacement in relation to sham and ovariectomy, respectively, suggesting sex-specific regulation of release. In conclusion, our observations reveal sex differences in the number of kisspeptin- and NKB-ir cells, which are more prominent in the caudal ARC. The divergent regulation of kisspeptin and NKB peptide contents in the ARC as a function of sex and steroid milieu enlarge our understanding on how these neuropeptides are posttranscriptionally regulated in KNDy neurons. PMID:25051440

Overgaard, Agnete; Ruiz-Pino, Francisco; Castellano, Juan M; Tena-Sempere, Manuel; Mikkelsen, Jens D

2014-10-01

81

The progestin levonorgestrel disrupts gonadotropin expression and sex steroid levels in pubertal roach (Rutilus rutilus).  

Science.gov (United States)

The aim of the present study was to investigate the effects of the synthetic progestin levonorgestrel (LNG) on the reproductive endocrine system of a teleost fish, the roach (Rutilus rutilus). Pubertal roach were exposed for 28 days in a flow-through system to four concentrations of LNG (3, 31, 312, and 3124 ng/l). Both males and females treated with 3124 ng/l LNG exhibited the upregulated levels of vitellogenin and oestrogen receptor 1 mRNA in the liver. At the same concentration, LNG caused a significant upregulation of the mRNA expression of the gene encoding luteinising hormone ?-subunit (lh?) and the suppression of the mRNA expression of the gene encoding follicle-stimulating hormone ?-subunit (fsh?) in the pituitary of both male and female roach. A lower LNG concentration (312 ng/l) suppressed mRNA expression of fsh? in males only. Females treated with 3124 ng/l LNG exhibited significantly lower plasma 11-ketotestosterone (11-KT) and oestradiol (E2) concentrations, whereas their testosterone (T) level was higher compared with the control. Females exposed to 312 ng/l LNG presented significantly lower plasma E2 concentrations. Males exposed to ?31 ng/l LNG exhibited significantly reduced 11-KT levels. As determined through a histological analysis, the ovaries of females were not affected by LNG exposure, whereas the testes of males exposed to 31 and 312 ng/l LNG exhibited a significantly higher percentage of spermatogonia B compared with the control. The results of the present study demonstrate that LNG disrupts the reproductive system of pubertal roach by affecting the pituitary gonadotropin expression and the sex steroid levels. This disruption was determined to occur in males after exposure to an environmentally relevant concentration (31 ng/l). Moreover, the highest tested concentration of LNG (3124 ng/l) exerted an oestrogenic effect on fish of both sexes. PMID:24893273

Kroupova, H K; Trubiroha, A; Lorenz, C; Contardo-Jara, V; Lutz, I; Grabic, R; Kocour, M; Kloas, W

2014-09-01

82

The studies of controlled release of sex steroids hormones by radiation induced polymerization of glass forming monomers  

International Nuclear Information System (INIS)

The continuous long-term systemic administration of steroid hormones to rats was attempted by the capsules. Glass capsules containing sex hormone were made by low-temperature radiation-induced polymerization. Testosterone was eluted at a constant speed up to the 120th day in vitro, and could be administered up to the 56th day in vivo. The amount of testosterone released in vitro up to the 120th day was only 10% of the content. (Chiba, N.)

83

The hepatic receptor for sex steroid-binding protein: study on a non-malignant cell line (Chang liver).  

OpenAIRE

The binding of human sex steroid-binding protein (SBP), labelled with 125I, was studied on whole cultured liver cells (Chang liver cells). SBP was shown to bind to a receptor site on normal hepatocytes. The binding was time- and temperature-dependent, highly specific and of high affinity. The liver receptor recognizing SBP was demonstrated to be different from the asialoglycoprotein receptor; in addition, laminin, which is structurally related to SBP, could not bind to the receptor. SBP was s...

Frairia, Roberto; Berta, Laura Adelaide Angela

1993-01-01

84

Sex steroids and the growth hormone/insulin-like growth factor-I axis in adults  

DEFF Research Database (Denmark)

In healthy adults insulin-like growth factor (IGF)-I levels do not differ between males and females, whereas spontaneous growth hormone (GH) secretion is approximately twofold higher in females. Untreated GH-deficient (GHD) women exhibit lower IGF-I levels compared with men and the increase in serum IGF-I during GH replacement is also significantly less. These data suggest a resistance to GH in women, which in healthy subjects is compensated for by increased GH secretion. Administration of oral oestrogen in healthy postmenopausal women suppresses hepatic IGF-I production and increases pituitary GH release, and oral oestrogen replacement in women with GHD lowers IGF-I concentrations and increases the amount of GH necessary to achieve IGF-I target levels during treatment. These data clearly suggest that hepatic suppression of IGF-I production by oestrogen subserves the gender difference in GH sensitivity, but it is also likely that sex steroids may interact with the GH/IGF axis at other levels. There is also circumstantial evidence to indicate that testosterone stimulates IGF-I production and it is speculated that a certain threshold level of androgens is essential to ensure hepatic IGF-I production. Whether these data should translate into earlier discontinuation of oestrogen replacement therapy in women with hypopituitarism merits consideration.

JØrgensen, Jens O L; Vestergaard, Esben

2005-01-01

85

Sex-related differences in steroid concentrations in the blue mussel (Mytilus edulis trossulus) from the southern Baltic Sea.  

Science.gov (United States)

This paper reports on sex-related differences in free steroid hormone concentrations including the concentrations of three naturally occurring estrogens (17?-estradiol E2, estrone E1, and estriol E3) and one androgen (testosterone T) in the tissues (gills and gonads) of the blue mussel Mytilus edulis trossulus sampled from the Gulf of Gda?sk (Baltic Sea, Poland). The dissimilarity in steroid concentrations between tissues was particularly evident in the T concentration with a level in gills almost three times higher compared to gonads (on average, 15.38ng/g w.w. and 5.31ng/g w.w., respectively, p=0.00008), suggesting its exogenous origin. In general, a tendency towards a skewed steroid profile related to sex, with E2 more abundant for males and T for females, was observed. Female gonads were characterized by a higher level of T than testis (4.61ng/g w.w. for females and 0.70ng/g w.w. for males, p=0.0121). At the same time, the level of E2 found in the testis was higher than in the ovary (4.81ng/g w.w. and 3.86ng/g w.w., respectively); however, the difference was not statistically significant. As for gills, similar trend with T and E2 being more abundant in males was observed. At the same time, no disturbances in the sex ratio and gametogenesis process were observed which suggests i) efficient deactivation of free forms of steroids, and/or ii) their little or no physiological role. PMID:25536333

Zabrza?ska, Sandra; Smolarz, Katarzyna; Hallmann, Anna; Konieczna, Lucyna; B?czek, Tomasz; Wo?owicz, Maciej

2015-05-01

86

Testosterone regulation of sex steroid-related mRNAs and dopamine-related mRNAs in adolescent male rat substantia nigra  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Increased risk of schizophrenia in adolescent males indicates that a link between the development of dopamine-related psychopathology and testosterone-driven brain changes may exist. However, contradictions as to whether testosterone increases or decreases dopamine neurotransmission are found and most studies address this in adult animals. Testosterone-dependent actions in neurons are direct via activation of androgen receptors (AR or indirect by conversion to 17?-estradiol and activation of estrogen receptors (ER. How midbrain dopamine neurons respond to sex steroids depends on the presence of sex steroid receptor(s and the level of steroid conversion enzymes (aromatase and 5?-reductase. We investigated whether gonadectomy and sex steroid replacement could influence dopamine levels by changing tyrosine hydroxylase (TH protein and mRNA and/or dopamine breakdown enzyme mRNA levels [catechol-O-methyl transferase (COMT and monoamine oxygenase (MAO A and B] in the adolescent male rat substantia nigra. We hypothesized that adolescent testosterone would regulate sex steroid signaling through regulation of ER and AR mRNAs and through modulation of aromatase and 5?-reductase mRNA levels. Results We find ER? and AR in midbrain dopamine neurons in adolescent male rats, indicating that dopamine neurons are poised to respond to circulating sex steroids. We report that androgens (T and DHT increase TH protein and increase COMT, MAOA and MAOB mRNAs in the adolescent male rat substantia nigra. We report that all three sex steroids increase AR mRNA. Differential action on ER pathways, with ER? mRNA down-regulation and ER? mRNA up-regulation by testosterone was found. 5? reductase-1 mRNA was increased by AR activation, and aromatase mRNA was decreased by gonadectomy. Conclusions We conclude that increased testosterone at adolescence can shift the balance of sex steroid signaling to favor androgenic responses through promoting conversion of T to DHT and increasing AR mRNA. Further, testosterone may increase local dopamine synthesis and metabolism, thereby changing dopamine regulation within the substantia nigra. We show that testosterone action through both AR and ERs modulates synthesis of sex steroid receptor by altering AR and ER mRNA levels in normal adolescent male substantia nigra. Increased sex steroids in the brain at adolescence may alter substantia nigra dopamine pathways, increasing vulnerability for the development of psychopathology.

Purves-Tyson Tertia D

2012-08-01

87

Adults with Prader-Willi syndrome have weaker bones: effect of treatment with GH and sex steroids.  

Science.gov (United States)

Obesity has been considered to have a protective effect against the risk of fractures in adults. However, a high frequency of fracture is described in obese adults with Prader-Willi syndrome. To evaluate bone geometry, density and strength in a group of adult obese patients with Prader-Willi syndrome (PWS) and to examine the modulating effect on bone of treatment with growth hormone (GH) and sex steroids. This was a cross-sectional study performed in 41 (17 males, 24 females) obese subjects with genetically confirmed PWS, aged 29.4 ± 8.6 years. Forty-six healthy subjects (22 males and 24 females) served as controls. Digitalized X-rays were evaluated at the level of the 2nd metacarpal bone to assess bone geometry, i.e. cross-sectional area (CSA), cortical area (CA), medullary area (MA), metacarpal index (MI) and bone strength evaluated as bending breaking resistance index (BBRI). DEXA was also used to evaluate body composition and bone mineral density (total body, lumbar spine and femoral neck). PWS subjects, after adjusting for height and bone size, had a reduced CSA, CA and BBRI, while bone density was not different. GH treatment had a positive effect and sex steroids a negative effect on bone size and strength. PWS subjects showed a reduced bone size at the metacarpus leading to a reduced strength, while bone density was appropriate for size. GH treatment improves bone geometry but not bone density. Bone strength was significantly reduced in PWS patients who did not receive GH and had been treated with sex steroids. PMID:25577526

Longhi, Silvia; Grugni, Graziano; Gatti, Davide; Spinozzi, Emiliano; Sartorio, Alessandro; Adami, Silvano; Fanolla, Antonio; Radetti, Giorgio

2015-02-01

88

Organization of Cytochrome P450 Enzymes Involved in Sex Steroid Synthesis: PROTEIN-PROTEIN INTERACTIONS IN LIPID MEMBRANES*  

OpenAIRE

Mounting evidence underscores the importance of protein-protein interactions in the functional regulation of drug-metabolizing P450s, but few studies have been conducted in membrane environments, and none have examined P450s catalyzing sex steroid synthesis. Here we report specific protein-protein interactions for full-length, human, wild type steroidogenic cytochrome P450 (P450, CYP) enzymes: 17?-hydroxylase/17,20-lyase (P450c17, CYP17) and aromatase (P450arom, CYP19), as well as their elec...

Praporski, Slavica; Ng, Su May; Nguyen, Ann D.; Corbin, C. Jo; Mechler, Adam; Zheng, Jie; Conley, Alan J.; Martin, Lisandra L.

2009-01-01

89

Sex-related differences in metabolism of 14C-acetate in response to steroid hormones by isolated rat hepatocytes  

International Nuclear Information System (INIS)

No differences were found in the basal rate of lipid synthesis from 14C-acetate in hepatocytes isolated from mature male and virgin female rats. Lipid biosynthesis was stimulated 22-43% in the female 60 min after the addition of gonadal steroids. This rapid response suggests that subtle differences exist in the enzyme profile controlling the pathways of lipid metabolism in male and female rats. This difference may have been determined genetically or acquired after a period of sex-dependent hormonal stimulation beginning with puberty. (orig.)

90

Large scale genome-wide association and LDLA mapping study identifies QTLs for boar taint and related sex steroids  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Boar taint is observed in a high proportion of uncastrated male pigs and is characterized by an unpleasant odor/flavor in cooked meat, primarily caused by elevated levels of androstenone and skatole. Androstenone is a steroid produced in the testis in parallel with biosynthesis of other sex steroids like testosterone and estrogens. This represents a challenge when performing selection against androstenone in breeding programs, without simultaneously decreasing levels of other steroids. The aim of this study was to use high-density genome wide association (GWA in combination with linkage disequilibrium-linkage analysis (LDLA to identify quantitative trait loci (QTL associated with boar taint compounds and related sex steroids in commercial Landrace (n = 1,251 and Duroc (n = 918 breeds. Results Altogether, 14 genome wide significant (GWS QTL regions for androstenone in subcutaneous fat were obtained from the LDLA study in Landrace and 14 GWS QTL regions in Duroc. LDLA analysis revealed that 7 of these QTL regions, located on SSC 1, 2, 3, 7 and 15, were obtained in both breeds. All 14 GWS androstenone QTLs in Landrace are also affecting the estrogens at chromosome wise significance (CWS or GWS levels, while in Duroc, 3 of the 14 QTLs affect androstenone without affecting any of the estrogens. For skatole, 10 and 4 QTLs were GWS in the LDLA analysis for Landrace and Duroc respectively, with 4 of these detected in both breeds. The GWS QTLs for skatole obtained by LDLA are located at SSC 1, 5, 6, 7, 10, 11, 13 and 14. Conclusion This is the first report applying the Porcine 60 K SNP array for simultaneous analysis of boar taint compounds and related sex hormones, using both GWA and LDLA approaches. Several QTLs are involved in regulation of androstenone and skatole, and most of the QTLs for androstenone are also affecting the levels of estrogens. Seven QTLs for androstenone were detected in one breed and confirmed in the other, i.e. in an independent sample, although the majority of QTLs are breed specific. Most QTLs for skatole do not negatively affect other sex hormones and should be easier to implement into the breeding scheme.

Hansen Marianne HS

2011-07-01

91

Sex-specific development of spatial orientation is independent of peripubertal gonadal steroids.  

Science.gov (United States)

Prenatal exposure to androgens has been shown to modulate brain development, resulting in changed behavioral attitudes, sexual orientation and cognitive functions, including processing of spatial information. Whether later changes in gonadotropic hormones during puberty induce further organizational effects within the brain is still insufficiently understood. The purpose of this study was to assess development of spatial orientation before and after the time of normal pubertal development, in an ovine model where half of the animals did not undergo typical reproductive maturation due to the pharmacological blockade of gonadotropin releasing hormone receptor (GnRHR) signaling. The study formed part of a larger trial and utilized 46 pairs of same sex Scottish Mule Texel Cross twins (22 female and 24 male). One twin remained untreated throughout (control) while the other received a subcutaneous GnRH agonist (GnRHa: Goserelin-Acetate) implant every fourth week. GnRHa treatment began at eight and 28 weeks of age, in males and females respectively, because the timing of the pubertal transition is sexually differentiated in sheep as it is in humans. Spatial orientation was assessed at three different time points: eight weeks of age, before puberty and treatment in both sexes; 28 weeks of age, after 20 weeks GnRHa treatment in males and before puberty and GnRHa treatment in females; and at 48 weeks of age, which is after the normal time of the pubertal transition in both sexes. Spatial orientation was tested in a spatial maze with traverse time as the main outcome measure. GnRHa treatment did not affect spatial maze performance as no significant differences in traverse time between treated and untreated animals were observed at any time-point. Adolescent females (48 weeks of age) traversed the maze significantly faster than adolescent males, whereas no sex differences in traverse time were seen at earlier developmental stages (eight and 28 weeks). Development of sex differences in spatial orientation was independent of exposure to pubertal hormones since puberty-blocked and control animals both showed the same pattern of spatial maze performance. This result demonstrates the prenatal nature of spatial orientation development. Furthermore, the unexpected finding that female animals outperformed males in the spatial orientation task, underscores the importance of the testing context in spatial orientation experiments. PMID:23477973

Wojniusz, Slawomir; Ropstad, Erik; Evans, Neil; Robinson, Jane; Solbakk, Anne-Kristin; Endestad, Tor; Haraldsen, Ira Ronit Hebold

2013-09-01

92

Fertility in Tall Men and Women Treated with High-Dose Sex Steroids during Adolescence and Genetic Determinants of Tall Stature  

OpenAIRE

This doctoral thesis describes in a large group of constitutional tall men and women the long-term effects of high-dose sex steroid treatment to reduce final height and the genetic determinants of tall stature. In part 1 we evaluated fertility and gonadal function in later life of two independent cohorts of tall women and one cohort of tall men who did or did not receive high-dose sex steroid treatment in adolescence. We found that estrogen treated women experienced more difficulties conceivi...

Hendriks, A. E. J.

2012-01-01

93

Synthesis of measuring steroid metabolites in goose feces.  

Science.gov (United States)

The reliability of noninvasively measuring steroid hormones from feces in greylag geese (Anser anser) and domestic geese (A. domesticus), both qualitatively and quantitatively, was tested experimentally. Geese are mainly herbivorous birds with a short gut-passage time (2-3 h). Groups of eight outdoor-housed male domestic geese were subjected to two different experiments, injection of either GnRH or ACTH, which were replicated in three different seasons (spring, summer, and fall). GnRH stimulation resulted in significant increases of response fecal testosterone metabolites (TM; 17beta-OH-androgens) in spring and fall, but not during the summer photorefractoriness. Testosterone response patterns obtained from plasma samples paralleled those from feces; however, no direct correlation between individual immunoreactive plasma and feces contents was observed. To improve the sample handling during extraction and the assay sensitivity, we promote the use of a group-specific antibody against 17-oxoandrogens that does not require deconjugation prior to the analysis. ACTH robustly increased fecal corticosterone in all seasons. The polar nature of glucocorticoids, however, seems to make a distinction between conjugated and nonconjugated types difficult, and the available avian literature on this topic is discussed. PMID:16055848

Hirschenhauser, Katharina; Kotrschal, Kurt; Möstl, Erich

2005-06-01

94

Parasitic castration, growth, and sex steroids in the freshwater bonefish Cyphocharax gilbert (Curimatidae infested by Riggia paranensis (Cymothoidea  

Directory of Open Access Journals (Sweden)

Full Text Available Cyphocharax gilbert shows parasitic castration when infested by the crustacean Riggia paranensis, being unable to reproduce. Fish were sampled in the middle rio Itabapoana, Brazil, to study the prevalence of parasitism, growth, and sex steroid concentrations, considering the body size, sex, and reproductive condition of specimens. Most of the fish analyzed were infested (56.0%. The presence of two lines on the scales was more frequent among infested fish (22.0% than among fish without parasites (12.0% for females and 10.0% for males. The occurrence of three lines on the scales was rare (3.5% among infested and 2.0% among females without parasites. These results suggest that growth of the host is faster than that of non infested fish. The serum concentrations of sex steroids from fish without parasites varied at different gonadal development stages (17 beta-estradiol: 60.0 to 976.7 pg/ml; total testosterone: 220.0 to 3,887.7 pg/ml. All infested fish had lower levels of the two sex steroids and undeveloped gonads. Sex steroids levels in infested females were close to those in females at post-spawning stages. Total testosterone concentrations of infested males were below those of males at early gonadal maturation stage. These results suggest that R. paranensis reduces the reproductive capacity of C. gilbert by affecting the host endocrine system.Cyphocharax gilbert exibe castração parasitária quando está infestado pelo crustáceo Riggia paranensis, estando impossibilitado de reproduzir. Os peixes foram coletados no trecho médio do rio Itabapoana, Brasil, para analisar a prevalência do parasitismo, quantificar crescimento e as concentrações de esteróides sexuais, considerando o tamanho do corpo, o sexo e a condição reprodutiva dos espécimes. A maioria dos peixes analisados estava infestada (56,0%. A presença de duas linhas em escamas foi mais freqüente entre os peixes infestados (22,0% que entre os peixes não infestados (12,0% para as fêmeas e 10,0% para os machos. A presença de três linhas na escama foi rara (3,5% entre os peixes infestados e 2,0% entre as fêmeas não infestadas. Estes resultados sugerem que o crescimento no hospeideiro pode ser mais rapido que no peixes não parasitados. As concentrações de esteróides sexuais no soro dos peixes não infestados variaram entre os diferentes estágios reprodutivos (17 beta-estradiol: 60,0 a 976,7 pg/ml; total testosterona: 220,0 a 3.887,7 pg/ml. Todos os peixes infestados apresentaram baixos níveis dos dois hormônios esteroidais e ausência de desenvolvimento gonadal. Os níveis de esteróides sexuais nas fêmeas infestadas foram próximos aos níveis encontrados nas fêmeas pós-desovadas. A concentração de testosterona encontrada nos machos infestados foi inferior àquela obtida nos machos que estavam iniciando o desenvolvimento gonadal. Estes resultados sugerem que R. paranensis impede a reprodução de C. gilbert, afetando o sistema endócrino do hospedeiro.

Neuza R. W. Lima

2007-12-01

95

Parasitic castration, growth, and sex steroids in the freshwater bonefish Cyphocharax gilbert (Curimatidae) infested by Riggia paranensis (Cymothoidea)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Cyphocharax gilbert exibe castração parasitária quando está infestado pelo crustáceo Riggia paranensis, estando impossibilitado de reproduzir. Os peixes foram coletados no trecho médio do rio Itabapoana, Brasil, para analisar a prevalência do parasitismo, quantificar crescimento e as concentrações d [...] e esteróides sexuais, considerando o tamanho do corpo, o sexo e a condição reprodutiva dos espécimes. A maioria dos peixes analisados estava infestada (56,0%). A presença de duas linhas em escamas foi mais freqüente entre os peixes infestados (22,0%) que entre os peixes não infestados (12,0% para as fêmeas e 10,0% para os machos). A presença de três linhas na escama foi rara (3,5% entre os peixes infestados e 2,0% entre as fêmeas não infestadas). Estes resultados sugerem que o crescimento no hospeideiro pode ser mais rapido que no peixes não parasitados. As concentrações de esteróides sexuais no soro dos peixes não infestados variaram entre os diferentes estágios reprodutivos (17 beta-estradiol: 60,0 a 976,7 pg/ml; total testosterona: 220,0 a 3.887,7 pg/ml). Todos os peixes infestados apresentaram baixos níveis dos dois hormônios esteroidais e ausência de desenvolvimento gonadal. Os níveis de esteróides sexuais nas fêmeas infestadas foram próximos aos níveis encontrados nas fêmeas pós-desovadas. A concentração de testosterona encontrada nos machos infestados foi inferior àquela obtida nos machos que estavam iniciando o desenvolvimento gonadal. Estes resultados sugerem que R. paranensis impede a reprodução de C. gilbert, afetando o sistema endócrino do hospedeiro. Abstract in english Cyphocharax gilbert shows parasitic castration when infested by the crustacean Riggia paranensis, being unable to reproduce. Fish were sampled in the middle rio Itabapoana, Brazil, to study the prevalence of parasitism, growth, and sex steroid concentrations, considering the body size, sex, and repr [...] oductive condition of specimens. Most of the fish analyzed were infested (56.0%). The presence of two lines on the scales was more frequent among infested fish (22.0%) than among fish without parasites (12.0% for females and 10.0% for males). The occurrence of three lines on the scales was rare (3.5% among infested and 2.0% among females without parasites). These results suggest that growth of the host is faster than that of non infested fish. The serum concentrations of sex steroids from fish without parasites varied at different gonadal development stages (17 beta-estradiol: 60.0 to 976.7 pg/ml; total testosterone: 220.0 to 3,887.7 pg/ml). All infested fish had lower levels of the two sex steroids and undeveloped gonads. Sex steroids levels in infested females were close to those in females at post-spawning stages. Total testosterone concentrations of infested males were below those of males at early gonadal maturation stage. These results suggest that R. paranensis reduces the reproductive capacity of C. gilbert by affecting the host endocrine system.

Neuza R. W., Lima; Juliana de S., Azevedo; Leonardo G. da, Silva; Marilvia, Dansa-Petretski.

2007-12-01

96

Serum pituitary and sex steroid hormone levels in the etiology of prostatic cancer--a population-based case-control study.  

OpenAIRE

The hypothesis that serum concentrations of pituitary hormones, sex steroid hormones, or sex hormone-binding globulin (SHBG) affect the occurrence of prostatic cancer was tested in a consecutive sample of 93 patients with newly diagnosed, untreated cancer and in 98 population controls of similar ages without the disease. Cases did not differ significantly from controls regarding serum levels of luteinising hormone (LH) or follicle stimulating hormone (FSH). Remarkably close agreement was foun...

Andersson, S. O.; Adami, H. O.; Bergstro?m, R.; Wide, L.

1993-01-01

97

Waste products of oilsands mine inhibit sex steroids in exposed fish  

Energy Technology Data Exchange (ETDEWEB)

Mature fine tailings (MFT) and tailing pond water (TPW) are two of the wastes generated by oil sand mining operations at Syncrude Canada Ltd. in northern Alberta. A study was conducted to determine the impact of these wastes on reproductive steroid production in sexually mature goldfish. MFT is a toxic aqueous suspension consisting of organic acids, bitumen and metals. TPW is a saline solution consisting of both organic and inorganic contaminants. Goldfish were examined for 19 days in 3 of Syncrude's specially designed experimental ponds which were lined with or without MFT and capped with or without TPW. The study showed that plasma levels of testosterone and 17 {beta}-estradiol in male and female fish in ponds with MFT but no TPW and ponds with both MFT and TPW were much lower compared to fish in a control pond with neither MFT nor TPW. The study also involved in vitro testis and ovarian incubations on the fish to determine potential differences in basal steroid production levels and how they react to gonadotropin. Results showed that gonadal tissues of fish from all ponds behaved similarly to the gonadotropin, thereby suggesting that under normal conditions, the oilsands wastes do not affect the ability of gonads to produce steroids. Compared to the control pond, both male and female fish from the pond with both MFT and TPW had significantly lower basal levels of testosterone, suggesting that the steroid inhibition could be caused at a site within the gonad. It was concluded that waste products of oilsands mining disrupt the reproductive endocrine system in goldfish.

Lister, A.; Van Der Kraak, G.J. [Guelph Univ., ON (Canada); Nero, V.; Farwell, A.J.; Dixon, D.G. [Waterloo Univ., ON (Canada). Dept. of Biology

2002-07-01

98

Waste products of oilsands mine inhibit sex steroids in exposed fish  

International Nuclear Information System (INIS)

Mature fine tailings (MFT) and tailing pond water (TPW) are two of the wastes generated by oil sand mining operations at Syncrude Canada Ltd. in northern Alberta. A study was conducted to determine the impact of these wastes on reproductive steroid production in sexually mature goldfish. MFT is a toxic aqueous suspension consisting of organic acids, bitumen and metals. TPW is a saline solution consisting of both organic and inorganic contaminants. Goldfish were examined for 19 days in 3 of Syncrude's specially designed experimental ponds which were lined with or without MFT and capped with or without TPW. The study showed that plasma levels of testosterone and 17 ?-estradiol in male and female fish in ponds with MFT but no TPW and ponds with both MFT and TPW were much lower compared to fish in a control pond with neither MFT nor TPW. The study also involved in vitro testis and ovarian incubations on the fish to determine potential differences in basal steroid production levels and how they react to gonadotropin. Results showed that gonadal tissues of fish from all ponds behaved similarly to the gonadotropin, thereby suggesting that under normal conditions, the oilsands wastes do not affect the ability of gonads to produce steroids. Compared to the control pond, both male and female fish from the pond with both MFT and TPW had significantly lower basal levels of testosterone, suggesting that the steroid inhibition could be caused at a site within the gonad. It was coned at a site within the gonad. It was concluded that waste products of oilsands mining disrupt the reproductive endocrine system in goldfish

99

Influence of mesonephros on foetal and neonatal rabbit gonads. I. Sex-steroid release by the testis in vitro  

DEFF Research Database (Denmark)

The experiments were performed to study the influence of mesonephros on gonadal sex hormone release. Foetal and neonatal rabbit testes were cultured for 5 days, with and without their mesonephric tissue. The culture media were harvested every day and analyzed by RIA for the content of testosterone, progesterone and oestradiol. The development of the tissues were evaluated microscopically after culturing. The results show that between day 20 pc and day 1 pp the mesonephric tissue lowered the amounts of testosterone in co-cultures with testis. This effect disappears when the mesonephric derived cells develop the capacity to synthesize a meiosis inducing substance (MIS). A relationship between decrease of testosterone and secretion of MIS is discussed. It is concluded that the steroid producing cells of the testis, the Leydig cells, originate or are heavily influenced by mesonephros during early testicular organogenesis.

Grinsted, Jacob Peter; Byskov, A G

1982-01-01

100

Sex-specific effect of the anabolic steroid, 17?-methyltestosterone, on inhibitory avoidance learning in periadolescent rats.  

Science.gov (United States)

The illicit use of anabolic androgenic steroids (AAS) has gained popularity among adolescents in the last decade. However, although it is known that exposure to AAS impairs cognition in adult animal models, the cognitive effects during adolescence remain undetermined. An inhibitory avoidance task (IAT) was used to assess the effect of AAS (17?-methyltestosterone; 17?-meT--7.5 mg/kg) in male and female periadolescent rats. A single injection of 17?-meT immediately before the footshock produced significant impairment of inhibitory avoidance learning in males but not females. Generalized anxiety, locomotion, and risk assessment behaviors (RAB) were not affected. Our results show that exposure to a single pharmacological dose of 17?-meT during periadolescence exerts sex-specific cognitive effects without affecting anxiety. Thus, disruption of the hormonal milieu during this early developmental period might have negative impact on learning and memory. PMID:23792034

Ramos-Pratts, Keyla; Rosa-González, Dariana; Pérez-Acevedo, Nivia L; Cintrón-López, Dahima; Barreto-Estrada, Jennifer L

2013-10-01

101

Effects of dopamine 2 receptor antagonist on sex steroid levels, oocyte maturation and spawning performances in Waigieu seaperch (Psammoperca waigiensis).  

Science.gov (United States)

The present study has investigated the effects of domperidone (DOM), a dopamine 2 receptor antagonist, on plasma steroid hormone levels and reproductive performances of a female tropical marine finfish, Waigieu seaperch (Psammoperca waigiensis), with potential for cultivation in Vietnam. We showed that oral treatment of DOM during early stage of the reproductive cycle had no significant effects on the maturation and reproductive performances of the female fish, while plasma steroid hormone (testosterone (T), 11-ketotestosterone (11-KT), 17?-estradiol (E2) and progesterone (P)) levels were modulated based on month, DOM dose and the individual hormones measured. Overall, these findings suggest that DOM may not be needed for the induction of maturation and spawning of this species under aquaculture conditions. The data in the present study are significant in highlighting practical efforts for reducing drug use, production costs and for a sustainable aquaculture in a developing country such as Vietnam. PMID:22911104

Pham, Hung Quoc; Arukwe, Augustine

2013-04-01

102

The macrophage low-grade inflammation marker sCD163 is modulated by exogenous sex steroids  

DEFF Research Database (Denmark)

Soluble CD163 (sCD163) is a novel marker linked to states of low-grade inflammation such as diabetes, obesity, liver disease, and atherosclerosis, all prevalent in subjects with Turner syndrome (TS) and Klinefelter syndrome (KS). We aimed to assess the levels of sCD163 and the regulation of sCD163 in regards to treatment with sex hormone therapy in males with and without KS and females with and without TS. Males with KS (n=70) and age-matched controls (n=71) participating in a cross-sectional study and 12 healthy males from an experimental hypogonadism study. Females with TS (n=8) and healthy age-matched controls (n=8) participating in a randomized crossover trial. The intervention comprised of treatment with sex steroids. Males with KS had higher levels of sCD163 compared with controls (1.75 (0.47-6.90) and 1.36 (0.77-3.11) respectively, P

Thomsen, Henrik; MØller, Holger Jon

2013-01-01

103

Noninvasive Measurement of Steroid Hormones in Zebrafish Holding-Water  

OpenAIRE

Zebrafish (Danio rerio) has recently emerged as a new animal model in neuroendocrinology and behavior (e.g., stress physiology and ecotoxicology studies). In these areas, the concentrations of steroid hormones in the blood are often used to study the endocrinological status of individuals. However, due to the small body size of zebrafish, blood sampling is difficult to perform and the amount of plasma obtained per sample for assaying hormones is very small (ca. 1–5??L), and therefore mos...

Fe?lix, Ana S.; Faustino, Ana I.; Cabral, Eduarda M.; Oliveira, Rui F.

2013-01-01

104

Simplified method for measuring sex-hormone binding globulin  

International Nuclear Information System (INIS)

We describe a simple, rapid method for measurement of sex-hormone binding globulin. Serial dilutions of pregnancy serum are prepared in serum from males that has been pre-treated by heating to 60 degrees C for 1 h to destroy endogenous binding globulin, which is then determined by a long-used technique to yield a set of ''standards.'' In the assay itself, a fixed amount of [3H]-labeled and unlabeled dihydrotestosterone is incubated with standard or unknown, and the bound fraction precipitated with saturated ammonium sulfate. A plot of percent of the steroid bound vs standard dilution yields a sigmoid curve, from which the results in unknowns can be read by simple extrapolation. Within-assay CVs for pools of serum from men, women, and women in late pregnancy were 6.56, 9.59, and 8.4%, respectively. Between-assay CVs for the same pools were 8.05, 9.5, and 11.5%, respectively. The correlation between results obtained by this method and those of the older technique was 0.95 for samples from non-pregnant subjects and 0.73 for those from pregnant women. Our procedure is simpler and faster than previous methods and accurately measures the differences in the globulin in sera from men, women, and pregnant women. Forty to 50 samples can be assayed in a working day

105

Novel galanin receptors in teleost fish: identification, expression and regulation by sex steroids.  

Science.gov (United States)

In fish, the onset of puberty, the transition from juvenile to sexually reproductive adult animals, is triggered by the activation of pituitary gonadotropin secretion and its timing is influenced by external and internal factors that include the growth/adiposity status of the animal. Kisspeptins have been implicated in the activation of puberty but peripheral signals coming from the immature gonad or associated to the metabolic/nutritional status are also thought to be involved. Therefore we hypothesize the importance of the galinergic system in the brain and testis of pre-pubertal male sea bass as a candidate to translate the signals leading to activation of testicular maturation. Here, the transcripts for four galanin receptors (GALR), named GALR1a, 1b, 2a and 2b, were isolated from European sea bass, Dicentrarchus labrax. Phylogenetic analysis confirmed the previously reported duplication of GALR1 in teleost fish, and unravelled the duplication of GALR2 in teleost fish and in some tetrapod species. Comparison with human showed that the key amino acids involved in ligand binding are present in the corresponding GALR1 and GALR2 orthologs. Transcripts for all four receptors are expressed in brain and testes of adult fish with GALR1a and GALR1b abundant in testes and hardly detected in ovaries. In order to investigate whether GALR1 dimorphic expression was dependent on steroid context we evaluated the effect of 11-ketotestosterone and 17?-estradiol treatments on the receptor expression in brain and testes of pre-pubertal males. Interestingly, steroid treatments had no effect on the expression of GALRs in the brain while in the testes, GALR1a and GALR1b were significantly up regulated by 11KT. Altogether, these results support a role for the galaninergic system, in particular the GALR1 paralog, in fish reproductive function. PMID:25016048

Martins, Rute S T; Pinto, Patrícia I S; Guerreiro, Pedro M; Zanuy, Silvia; Carrillo, Manuel; Canário, Adelino V M

2014-09-01

106

The moderating impact of lifestyle factors on sex steroids, sexual activities and aging in Asian men  

OpenAIRE

The present study sought to evaluate the relative associations of exercise, sleep and other lifestyle habits with aging, sex hormones, percent body fat (%BF) and sexual activities in men living in the community. A better understanding of this complex interrelationship is important in helping the formulation of modalities for a holistic approach to the management of aging men. The results showed that age is a major determinant for many physiological parameters, including sleep, hormonal and me...

Goh, Victor Hh; Tong, Terry Yy

2011-01-01

107

Mono-hydroxy methoxychlor alters levels of key sex steroids and steroidogenic enzymes in cultured mouse antral follicles  

International Nuclear Information System (INIS)

Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by decreasing antral follicle numbers and increasing follicular death. MXC is metabolized in the body to mono-hydroxy MXC (mono-OH). Little is known about the effects of mono-OH on the ovary. Thus, this work tested the hypothesis that mono-OH exposure decreases production of 17?-estradiol (E2) by cultured mouse antral follicles. Antral follicles were isolated from CD-1 mice (age 35-39 days) and exposed to dimethylsulfoxide (DMSO), or mono-OH (0.1-10 ?g/mL) for 96 h. Media and follicles were collected for analysis of sex steroid levels and mRNA expression, respectively. Mono-OH treatment (10 ?g/mL) decreased E2 (DMSO: 3009.72 ± 744.99 ng/mL; mono-OH 0.1 ?g/mL: 1679.66 ± 461.99 ng/mL; 1 ?g/mL: 1752.72 ± 532.41 ng/mL; 10 ?g/mL: 45.89 ± 33.83 ng/mL), testosterone (DMSO: 15.43 ± 2.86 ng/mL; mono-OH 0.1 ?g/mL: 17.17 ± 4.71 ng/mL; 1 ?g/mL: 13.64 ± 3.53 ng/mL; 10 ?g/mL: 1.29 ± 0.23 ng/mL), androstenedione (DMSO: 1.92 ± 0.34 ng/mL; mono-OH 0.1 ?g/mL: 1.49 ± 0.43 ng/mL; 1 ?g/mL: 0.64 ± 0.31 ng/mL; 10 ?g/mL: 0.12 ± 0.06 ng/mL) and progesterone (DMSO: 24.11 ± 4.21 ng/mL; mono-OH 0.1 ?g/mL: 26.77 ± 4.41 ng/mL; 1 ?g/mL: 20.90 ± 3.75 ng/mL; 10 ?g/mL: 9.44 ± 2.97 ng/mL) levels. Mono-OH did not alter expression of Star, Hsd3b1, Hsd17b1 and Cyp1b1, but it did reduce levels of Cyp11a1, Cyp17a1 and Cyp19a1 mRNA. Collectively, these data suggest ta suggest that mono-OH significantly decreases levels of key sex steroid hormones and the expression of enzymes required for steroidogenesis.

108

The impact of common genetic variations in genes of the sex hormone metabolic pathways on steroid hormone levels and prostate cancer aggressiveness.  

Science.gov (United States)

Our previous work suggested that there was no significant association between plasma steroid hormone levels and prostate cancer tumor grade at diagnosis. In this study, we systematically tested the hypothesis that inherited variations in the androgen and estrogen metabolic pathways may be associated with plasma levels of steroid hormones, or prostate cancer aggressiveness at diagnosis. Plasma hormone levels including total testosterone, total estradiol, and sex hormone-binding globulin were measured in a cohort of 508 patients identified with localized prostate cancer. D'Amico risk classification at diagnosis was also determined. A total of 143 single-nucleotide polymorphisms (SNPs) from 30 genes that are involved in androgen and estrogen metabolism were selected for analysis. The global association of genotypes with plasma hormone levels and prostate cancer aggressiveness (D'Amico risk classification) was statistically analyzed. Q values were estimated to account for multiple testing. We observed significant associations between plasma testosterone level and SNPs in HSD17B2 (rs1424151), HSD17B3 (rs9409407), and HSD17B1 (rs12602084), with P values of 0.002, 0.006, and 0.006, respectively. We also observed borderline significant associations between prostate aggressiveness at diagnosis and SNPs in AKR1C1 (rs11252845; P = 0.005), UGT2B15 (rs2045100; P = 0.007), and HSD17B12 (rs7932905; P = 0.008). No individual SNP was associated with both clinical variables. Genetic variants of genes in hormone metabolic pathways may influence plasma androgen levels or prostate cancer aggressiveness. However, it seems that the inherited variations affecting plasma hormone levels differ from those affecting disease aggressiveness. PMID:21900597

Sun, Tong; Oh, William K; Jacobus, Susanna; Regan, Meredith; Pomerantz, Mark; Freedman, Matthew L; Lee, Gwo-Shu Mary; Kantoff, Philip W

2011-12-01

109

Suppression of sex behavior by kappa opiates and stress steroids occurs via independent neuroendocrine pathways.  

Science.gov (United States)

Endocannabinoids and their receptors are found throughout the brain of all vertebrates. By virtue of their wide distribution, endocannabinoids have the potential to affect many behaviors. Prior research has shown that cannabinoids inhibit courtship-clasping and mediate behavioral responses to stress in male rough-skinned newts, Taricha granulosa, and cannabinoid signaling is initiated by rapid actions of the steroid corticosterone (CORT) at its specific membrane receptor (mCR). This same mCR also recognizes ?-opioid receptor agonists and antagonists. Prior behavioral studies show that ?-opioid agonists suppress clasping behavior in a dose dependent manner. Combined, these studies suggest that ?-opioid agonists might suppress clasping behavior via the same pathway initiated by CORT: up-regulation of endocannabinoid signaling. We examined whether pretreatment with a CB1 antagonist, AM281, would block ?-opioid-mediated suppression of clasping. We found that the CB1 antagonist did not reverse ?-opioid-induced suppression of clasping, revealing that while endocannabinoids mediate CORT-induced suppression of clasping, endocannabinoids do not mediate the ?-opioid-induced suppression of clasping. PMID:25307952

Lombana, Karla; Middleton, Natalie; Coddington, Emma

2015-01-01

110

Determination of steroid sex hormones in real matrices by bar adsorptive microextraction (BA?E).  

Science.gov (United States)

In the present work, the development of a novel analytical approach which combines a miniaturized bar adsorptive microextraction device with a micro-liquid desorption in one single step, followed by high performance liquid chromatography with diode array detection (BAµE-µLD/HPLC-DAD), is proposed for the determination of trace levels of nine steroid hormones (estriol, 17ß-estradiol, 17?-estradiol, 19-northisterone, 17?-ethynylestradiol, estrone, D-(-)-norgestrel, progesterone and mestranol) in environmental and biological matrices. From the comparison of ten different coating phases (five polymeric and five activated carbon sorbents), the modified pyrrolidone polymer (P2) showed the best compromise between selectivity and efficiency. Assays performed through BAµE(P2, 1.3mg)-µLD(100µL)/HPLC-DAD on 25mL of ultrapure water samples spiked at the 6.0?g/L level, yielded recoveries ranging from 93±9% to 101±8%, under optimized experimental conditions. The analytical performance showed convenient detection (50.0-100.0ng/L) and quantification limits (165.0-330.0ng/L), as well as good linear dynamic ranges (0.2-24.0µg/L) with remarkable determination coefficients (r(2)>0.9968). Excellent repeatability were also achieved through intraday (RSDcombined with the minimization of the solvent volume for back-extraction in one single step demonstrated remarkable performance, increasing the enrichment factor, being simultaneously more easier to implement and environment friendly. PMID:25702996

Almeida, C; Nogueira, J M F

2015-05-01

111

Effects of long-term cortisol treatments on gonadal development, sex steroids levels and ovarian cortisol content in cultured great sturgeon Huso huso.  

Science.gov (United States)

The objective of this study was to examine the effect of cortisol implantations on gonadal development, sex steroid levels, and ovarian cortisol content in cultured great sturgeon Huso huso. Three groups of 5 fish for each treatment were considered. The experimental groups included: control (capsules containing cocoa butter alone), low cortisol (C(5); 5mg cortisol/kg body mass+cocoa butter) and, high cortisol (C(50); 50mg cortisol/kg body mass+cocoa butter). The capsules containing hormones and cocoa butter were intraperitoneally implanted into 3-year-old female fish at pre-vitellogenic stage (mean initial body mass 6809.7 ± 73 g) every 6 weeks over a 6-month period from January to June. The serum levels of cortisol, glucose, cholesterol and sex steroids (testosterone and 17?-estradiol) were determined at the initial time and three weeks after each implantation. Oocyte histological characteristics (the diameter and area of the oocyte, the diameter and area of the nucleus and the ratio of the nucleus area to the oocyte area) were measured at the end of the experiment and compared to those at the initial time. Ovarian cortisol content was measured at the end of the experiment. The results showed that serum cortisol levels varied in a dose-independent manner, so that the highest cortisol concentrations were observed in C(5)-treated fish throughout the experiment. Serum glucose levels were significantly higher in cortisol-treated groups than those in the control group. The high dose of cortisol elicited a significant constant increase in serum cholesterol concentrations. Fish implanted with the high cortisol dose showed significant declines in serum testosterone and 17?-estradiol concentrations throughout the experiment. No significant differences were found in oocyte histological characteristics among experimental groups. The cortisol implants elicited a dose-dependent increase in ovarian cortisol content. At the end of trial, body-growth indices were the lowest in C(50)-implanted fish, while the low cortisol dose had no effect on growth relative to the controls. These results indicated that chronic stress induced by cortisol implantation in great sturgeon suppressed gonadal steroidogenesis and somatic growth but had no effect on ovarian growth and development. PMID:22643336

Poursaeid, Samaneh; Falahatkar, Bahram; Mojazi Amiri, Bagher; Van Der Kraak, Glen

2012-09-01

112

Effects of steroids and sex reversal on intestinal absorption of L-[14C]leucine in vivo, in rainbow trout, Salmo gairdneri  

International Nuclear Information System (INIS)

The effects of steroids (17 alpha-methyltestosterone (MT), 17 beta-oestradiol (E2)), and of sex reversal (XX male) on intestinal absorption and accumulation of L-[14C]leucine (5 mM), were investigated in unanaesthetized rainbow trout (Salmo gairdneri), using an in vivo gut perfusion technique. Each steroid was luminally perfused through the gut at a concentration of 50 micrograms/ml perfusate, during five separate perfusions carried out on the same fish at 30-min intervals (perfusion periods 1 to 5), for a total of 120 min at 14 degrees. Experiments were also conducted on masculinized, genetically female trout (XX male) with steroid-free perfusate. MT treatment significantly increased the intestinal absorption of radioleucine during periods 1 and 2, whilst E2 was without effect. Neither MT nor E2 influenced intestinal accumulation (mid- and hindgut) of radioleucine, and accumulation of 14C-solutes in skeletal muscle. Sex reversal, however, whilst having no effect on leucine absorption, nevertheless significantly increased intestinal accumulation of radioleucine, and accumulation of 14C-solutes in skeletal muscle. The effects observed in the present study are in agreement with previous work in trout using everted gut sac preparations. It is suggested that the growth-promoting effects of anabolic-androgenic steroids in fish may be partly explained by their action on gastrointestinal function

113

Effects of steroids and sex reversal on intestinal absorption of L-(/sup 14/C)leucine in vivo, in rainbow trout, Salmo gairdneri  

Energy Technology Data Exchange (ETDEWEB)

The effects of steroids (17 alpha-methyltestosterone (MT), 17 beta-oestradiol (E2)), and of sex reversal (XX male) on intestinal absorption and accumulation of L-(/sup 14/C)leucine (5 mM), were investigated in unanaesthetized rainbow trout (Salmo gairdneri), using an in vivo gut perfusion technique. Each steroid was luminally perfused through the gut at a concentration of 50 micrograms/ml perfusate, during five separate perfusions carried out on the same fish at 30-min intervals (perfusion periods 1 to 5), for a total of 120 min at 14 degrees. Experiments were also conducted on masculinized, genetically female trout (XX male) with steroid-free perfusate. MT treatment significantly increased the intestinal absorption of radioleucine during periods 1 and 2, whilst E2 was without effect. Neither MT nor E2 influenced intestinal accumulation (mid- and hindgut) of radioleucine, and accumulation of /sup 14/C-solutes in skeletal muscle. Sex reversal, however, whilst having no effect on leucine absorption, nevertheless significantly increased intestinal accumulation of radioleucine, and accumulation of /sup 14/C-solutes in skeletal muscle. The effects observed in the present study are in agreement with previous work in trout using everted gut sac preparations. It is suggested that the growth-promoting effects of anabolic-androgenic steroids in fish may be partly explained by their action on gastrointestinal function.

Habibi, H.R.; Ince, B.W.

1983-12-01

114

Effects of developmental exposure to 2,2 ,4,4 ,5-pentabromodiphenyl ether (PBDE-99) on sex steroids, sexual development, and sexually dimorphic behavior in rats  

OpenAIRE

Increasing concentrations of polybrominated flame retardants, including polybrominated diphenyl ethers (PBDEs), in breast milk cause concern about possible developmental effects in nursed babies. Because previous studies in rats have indicated effects on sex steroids and sexually dimorphic behavior after maternal exposure to polychlorinated biphenyls (PCBs), our goal in the present study was to determine if developmental exposure to 2,2?,4,4?,5-pentabromodiphenyl ether (PBDE-99) induces s...

Lilienthal, Hellmuth; Hack, Alfons; Roth-haerer, Astrid; Grande, Simone Wichert; Talsness, Chris E.

2006-01-01

115

An immunohistochemical analysis of sex-steroid receptors, tumor suppressor gene p53 and Ki-67 in the normal and neoplastic uterine cervix squamous epithelium  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction. Malignant transformation of sex-steroid dependent tissues is associated with the loss of expression of sex steroid receptors as well as of the tumor suppression gene p53. The aim of this study is to evaluate the expression of sex-steroid receptors, p53 and Ki-67 in specimens from pre-malignant and malignant cervical epithelial lesions throughout the menstrual cycle. Material and Methods. Immunohistochemical staining was performed on formalin fixed, paraffin embedded tissue sections of normal squamous cervical epithelium, cervical intraepithelial neoplasia and invasive squamous cervical carcinoma, specimens utilizing antibodies against estrogen receptors, progesterone receptors, p53 protein and Ki-67 antigen. Results. In the samples taken from the normal cervical tissue, basal cells were usually estrogen receptor-positive, progesterone receptornegative, p53-negative and Ki-67-negative throughout the menstrual cycle. In contrast, para-basal cells were estrogen receptorpositive and progesterone receptor-negative in the follicular phase, but estrogen receptor-negative and progesterone receptor -positive and Ki-67 positive in the luteal phase. In cervical precancerous and cancer tissue samples (cervical intraepithelial neoplasia and squamous cervical carcinoma, the expression of estrogen receptors decreased. 31.15% of cervical intraepithelial neoplasia and 11.5% of squamous cervical carcinoma were positive for estrogen receptors. However, the expression of progesterone receptors increased. 29.5% of cervical intraepithelial neoplasia and 49.2% of squamous cervical carcinoma were positive for progesterone receptors. Positive staining for p53 was observed in 15 (24.59% cases of cervical intraepithelial neoplasia and in 39 (64% of squamous cervical carcinoma. The expression Ki-67 index in squamous cervical carcinoma cases (47.60% was significantly higher than of cervical intraepithelial neoplasia cases (30.2% (p=0.041. Conclusion. The findings of this study suggest that tumor cervical cells evade normal growth control by sex steroid hormones while synchronously abnormal regulatory mechanisms acquire control of the cell cycle.

Nikolaou Marinos

2014-01-01

116

The Role of Ovarian Sex Steroids in Metabolic Homeostasis, Obesity, and Postmenopausal Breast Cancer: Molecular Mechanisms and Therapeutic Implications  

Science.gov (United States)

Obese postmenopausal women have an increased risk of breast cancer and are likely to have a worse prognosis than nonobese postmenopausal women. The cessation of ovarian function after menopause results in withdrawal of ovarian sex steroid hormones, estrogen, and progesterone. Accumulating evidence suggests that the withdrawal of estrogen and progesterone causes homeostasis imbalances, including decreases in insulin sensitivity and leptin secretion and changes in glucose and lipid metabolism, resulting in a total reduction in energy expenditure. Together with a decrease in physical activity and consumption of a high fat diet, these factors significantly contribute to obesity in postmenopausal women. Obesity may contribute to breast cancer development through several mechanisms. Obesity causes localized inflammation, an increase in local estrogen production, and changes in cellular metabolism. In addition, obese women have a higher risk of insulin insensitivity, and an increase in insulin and other growth factor secretion. In this review, we describe our current understanding of the molecular actions of estrogen and progesterone and their contributions to cellular metabolism, obesity, inflammation, and postmenopausal breast cancer. We also discuss how modifications of estrogen and progesterone actions might be used as a therapeutic approach for obesity and postmenopausal breast cancer.

2015-01-01

117

Inhaled Steroids  

Science.gov (United States)

... Diseases > Long-Term Control Medications > Inhaled Steroids Inhaled Steroids What are some common inhaled steroids? How are ... more about steroids? What are some common inhaled steroids? Common inhaled steroids include: Asmanex ® (mometasone) Alvesco ® (ciclesonide) ...

118

The influence of sex steroid hormones in the immunopathology of experimental pulmonary tuberculosis.  

Science.gov (United States)

The relation between men and women suffering pulmonary tuberculosis is 7/3 in favor to males. Sex hormones could be a significant factor for this difference, considering that testosterone impairs macrophage activation and pro-inflammatory cytokines production, while estrogens are proinflammatory mediator's inducer. The aim of this work was to compare the evolution of tuberculosis in male and female mice using a model of progressive disease. BALB/c mice, male and female were randomized into two groups: castrated or sham-operated, and infected by the intratracheal route with a high dose of Mycobacterium tuberculosis strain H37Rv. Mice were euthanized at different time points and in their lungs were determined bacilli loads, inflammation, cytokines expression, survival and testosterone levels in serum. Non-castrated male mice showed significant higher mortality and bacilli burdens during late disease than female and castrated male animals. Compared to males, females and castrated males exhibited significant higher inflammation in all lung compartments, earlier formation of granulomas and pneumonia, while between castrated and non-castrated females there were not significant differences. Females and castrated males expressed significant higher TNF-?, IFN ?, IL12, iNOS and IL17 than non-castrated males during the first month of infection. Serum Testosterone of males showed higher concentration during late infection. Orchidectomy at day 60 post-infection produced a significant decrease of bacilli burdens in coexistence with higher expression of TNF?, IL-12 and IFN?. Thus, male mice are more susceptible to tuberculosis than females and this was prevented by castration suggesting that testosterone could be a tuberculosis susceptibility factor. PMID:24722144

Bini, Estela Isabel; Mata Espinosa, Dulce; Marquina Castillo, Brenda; Barrios Payán, Jorge; Colucci, Darío; Cruz, Alejandro Francisco; Zatarain, Zyanya Lucía; Alfonseca, Edgar; Pardo, Marta Romano; Bottasso, Oscar; Hernández Pando, Rogelio

2014-01-01

119

Hepatic overexpression of steroid sulfatase ameliorates mouse models of obesity and type 2 diabetes through sex-specific mechanisms.  

Science.gov (United States)

The steroid sulfatase (STS)-mediated desulfation is a critical metabolic mechanism that regulates the chemical and functional homeostasis of endogenous and exogenous molecules. In this report, we first showed that the liver expression of Sts was induced in both the high fat diet (HFD) and ob/ob models of obesity and type 2 diabetes and during the fed to fasting transition. In defining the functional relevance of STS induction in metabolic disease, we showed that overexpression of STS in the liver of transgenic mice alleviated HFD and ob/ob models of obesity and type 2 diabetes, including reduced body weight, improved insulin sensitivity, and decreased hepatic steatosis and inflammation. Interestingly, STS exerted its metabolic benefit through sex-specific mechanisms. In female mice, STS may have increased hepatic estrogen activity by converting biologically inactive estrogen sulfates to active estrogens and consequently improved the metabolic functions, whereas ovariectomy abolished this protective effect. In contrast, the metabolic benefit of STS in males may have been accounted for by the male-specific decrease of inflammation in white adipose tissue and skeletal muscle as well as a pattern of skeletal muscle gene expression that favors energy expenditure. The metabolic benefit in male STS transgenic mice was retained after castration. Treatment with the STS substrate estrone sulfate also improved metabolic functions in both the HFD and ob/ob models. Our results have uncovered a novel function of STS in energy metabolism and type 2 diabetes. Liver-specific STS induction or estrogen/estrogen sulfate delivery may represent a novel approach to manage metabolic syndrome. PMID:24497646

Jiang, Mengxi; He, Jinhan; Kucera, Heidi; Gaikwad, Nilesh W; Zhang, Bin; Xu, Meishu; O'Doherty, Robert M; Selcer, Kyle W; Xie, Wen

2014-03-21

120

Sex differences in jealousy: evolutionary mechanism or artifact of measurement?  

Science.gov (United States)

Two studies are presented that challenge the evidentiary basis for the existence of evolved sex differences in jealousy. In opposition to the evolutionary view, Study I demonstrated that a sex difference in jealousy resulting from sexual versus emotional infidelity is observed only when judgments are recorded using a forced-choice response format. On all other measures, no sex differences were found; both men and women reported greater jealousy in response to sexual infidelity. A second study revealed that the sex difference on the forced-choice measure disappeared under conditions of cognitive constraint. These findings suggest that the sex difference used to support the evolutionary view of jealousy (e.g., D. M. Buss, R. Larsen, D. Westen, & J. Semmelroth, 1992; D. M. Buss et al., 1999) likely represents a measurement artifact resulting from a format-induced effortful decision strategy and not an automatic, sex-specific response shaped by evolution. PMID:12416915

DeSteno, David; Bartlett, Monica Y; Braverman, Julia; Salovey, Peter

2002-11-01

121

Histologia mamária após uso de esteróides sexuais - estudo em ratas / Breast histologic changes in female rats treated with sex steroids  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese OBJETIVO: Avaliar as alterações histológicas em mamas de ratas submetidas à terapêutica com estrogênio, progestogênio e tibolona. MÉTODOS: Estudo experimental com 40 ratas, sendo 20 sem prole (grupo A) e 20 com prole (grupo B). Todas as ratas foram castradas e, após quatro semanas, alocadas aleatori [...] amente em subgrupos: A1, A2, A3, A4, A5 e B1, B2, B3, B4, B5. Os esteróides foram administrados da seguinte forma: A1 e B1 - benzoato de estradiol; A2 e B2 - acetato de medroxiprogesterona; A3 e B3 - benzoato de estradiol e acetato de medroxiprogesterona; A4 e B4 - tibolona; A5 e B5 - placebo. Após dez semanas de tratamento, os animais foram sacrificados e suas glândulas mamárias submetidas à análise histológica. Os parâmetros avaliados foram: proliferação epitelial, atividade secretora e atipias epiteliais nas unidades de ductos ou alvéolos terminais. A associação entre os achados histológicos e os esquemas terapêuticos foi avaliada por meio do odds ratio e intervalo de confiança de 95%. RESULTADOS: Alterações histológicas foram observadas em 29 ratas: hiperplasia moderada (52,5%), hiperplasia alvéolo-nodular (42,5%), atipia sem proliferação (35%), hiperplasia leve (32,5%), atividade secretora (20%) e hiperplasia severa (5%). Em ratas sem prole observou-se 1,3 mais chance, em relação ao grupo controle, de apresentar hiperplasia alvéolo-nodular no grupo que recebeu estrogênio, hiperplasia moderada no grupo tratado com progestogênio, e hiperplasia alvéolo-nodular e atipia sem proliferação epitelial com a associação entre estrogênio e progestogênio. CONCLUSÃO: Hiperplasia moderada e atipia epitelial associaram-se à terapia combinada de estrogênio e progestogênio, e o antecedente de prole reduziu a ocorrência destas alterações e de hiperplasia alvéolo-nodular. Abstract in english OBJECTIVE: To evaluate the association of histologic changes in the breasts of female rats undergoing therapy with sex steroids. METHODS: An experimental study was conducted of 40 castrated female non-pubertal rats, 20 had given birth (Group B) and 20 had no offspring (Group A). After four weeks, th [...] ese rats were randomly allocated to subgroups: A1, A2, A3, A4, A5 and B1, B2, B3, B4, B5. Steroids were given to subgroups as follows: A1 and B1 - estradiol benzoate; A2 and B2 - medroxyprogesterone acetate; A3 and B3 - estradiol benzoate and medroxyprogesterone acetate; A4 and B4 - tibolone; A5 and B5 - placebo. After 10 weeks of treatment, animals were sacrificed and their mammary glands were analyzed. Histologic parameters evaluated were: epithelial cell proliferation, epithelial cells with secretory activity; and cell atypia in terminal duct units and buds or terminal alveoli. The association between microscopic analysis and diverse therapeutic regimens were analyzed by calculating the odds ratio and its respective 95% confidence interval. RESULTS: Histologic changes were observed in 29 rats: moderate hyperplasia (52.5%), hyperplastic alveolar nodule (42.5%), epithelial atypia (35%), mild hyperplasia (32.5%), secretory activity (20%) and severe hyperplasia (5%). In rats with no offspring when compared to the control, 1.3 times more hyperplastic alveolar nodules were found in the group treated with estradiol, the same was true for moderate hyperplasia in the rats that received medroxyprogesterone acetate, hyperplastic alveolar nodules and epithelial atypia in the group treated with estradiol plus medroxyprogesterone acetate. In the rats with offspring 1.3 times more secretory activity was found with estradiol. CONCLUSION: Epithelial hyperplasia and epithelial atypia with no proliferation are strongly associated to combined therapy with estradiol plus medroxyprogesterone acetate, mainly in the rats without offspring.

José Tadeu, Vicelli; Maria Salete Costa, Gurgel; Marcelo, Alvarenga.

2006-10-01

122

Melatonin reduces LH, 17 beta-estradiol and induces differential regulation of sex steroid receptors in reproductive tissues during rat ovulation  

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Full Text Available Abstract Background Melatonin is associated with direct or indirect actions upon female reproductive function. However, its effects on sex hormones and steroid receptors during ovulation are not clearly defined. This study aimed to verify whether exposure to long-term melatonin is able to cause reproductive hormonal disturbances as well as their role on sex steroid receptors in the rat ovary, oviduct and uterus during ovulation. Methods Twenty-four adult Wistar rats, 60 days old (+/- 250 g were randomly divided into two groups. Control group (Co: received 0.9% NaCl 0.3 mL + 95% ethanol 0.04 mL as vehicle; Melatonin-treated group (MEL: received vehicle + melatonin [100 ?g/100 g BW/day] both intraperitoneally during 60 days. All animals were euthanized by decapitation during the morning estrus at 4 a.m. Results Melatonin significantly reduced the plasma levels of LH and 17 beta-estradiol, while urinary 6-sulfatoximelatonin (STM was increased at the morning estrus. In addition, melatonin promoted differential regulation of the estrogen receptor (ER, progesterone receptor (PR, androgen receptor (AR and melatonin receptor (MTR along the reproductive tissues. In ovary, melatonin induced a down-regulation of ER-alpha and PRB levels. Conversely, it was observed that PRA and MT1R were up-regulated. In oviduct, AR and ER-alpha levels were down-regulated, in contrast to high expression of both PRA and PRB. Finally, the ER-beta and PRB levels were down-regulated in uterus tissue and only MT1R was up-regulated. Conclusions We suggest that melatonin partially suppress the hypothalamus-pituitary-ovarian axis, in addition, it induces differential regulation of sex steroid receptors in the ovary, oviduct and uterus during ovulation.

Pinheiro Patrícia Fernanda F

2011-08-01

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Dicamba affects sex steroid hormone level and mRNA expression of related genes in adult rare minnow (Gobiocypris rarus) at environmentally relevant concentrations.  

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Dicamba is a benzoic acid herbicide that has been detected in surface and ground water. The herbicide has been shown to have cytogeneic and DNA damaging effects and to cause organ damage in mammals; however, little is known about the endocrine disrupting effects of dicamba in fish. In this study, histological changes, plasma vitellogenin (VTG) and sex hormone levels, and mRNA expression of sex steroid hormone-related genes were determined in adult rare minnow exposed to environmentally relevant concentrations of dicamba (0, 0.05, 0.5, 5, and 50 ?g/L) for 40 days. The results showed inhibition of spermatogenesis in male testes and ovarian degeneration in females. Plasma 17?-estradiol (E2) levels were significantly increased in both genders, and plasma VTG levels were significantly increased in males (p?rare minnows (p < 0.05). The downregulation of cytochrome P450c19a (cyp19a) and steroidogenic acute regulatory protein (star) mRNA levels, and the upregulation of cytochrome P450c17 (cyp17) mRNA levels were observed in the livers and ovaries (p?steroid hormone-related gene expression could serve as a regulatory mechanism to maintain sex hormone homeostasis. Overall, dicamba exposure could result in histological lesions, plasma VTG increases, changes in sex hormone levels, and alterations of hormone-related gene expression. Therefore, dicamba should be considered to be a potential endocrine disruptor. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014. PMID:24420721

Zhu, Lifei; Li, Wei; Zha, Jinmiao; Wang, Zijian

2014-01-13

124

Influence of water temperature on induced reproduction by hypophysation, sex steroids concentrations and final oocyte maturation of the "curimatã-pacu" Prochilodus argenteus (Pisces: Prochilodontidae).  

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Most fishes with commercial importance from the São Francisco basin are migratory and do not complete the reproductive cycle in lentic environments, such as hydroelectric plant reservoirs, hence natural stocks are declining and there is an urgent need to reduce the pressure of fishing on those wild populations. Therefore, studies on reproductive biology and its relationship with endocrine and environmental factors are key to improving the cultivation techniques of Brazilian fish species. This study examined the influence of water temperature on sex steroid concentrations (testosterone, 17?-estradiol and 17?-hydroxyprogesterone), spawning efficiency, fecundity, fertilisation rate, larval abnormality rates and involvement of the cytoskeleton during the final oocyte maturation of Prochilodus argenteus under experimental conditions. The results of our study showed that in captivity, sex steroid plasma concentrations and spawning performance of P. argenteus were clearly different for fish kept in water with different temperature regimes. In lower water temperature (23°C), it was observed that: 33% of females did not ovulate, fecundity was lower and vitellogenic oocytes after the spawning induction procedure exhibited a smaller diameter. Moreover, concentrations of 17?-estradiol and 17?-hydroxyprogesterone were lower and there was a delay in the final oocyte maturation and, consequently, ovulation and spawning. Our experiments showed direct influence of water temperature in the process of induced spawning of P. argenteus. Changes in water temperature also suggest the tubulin involvement in the nuclear dislocation process and the possible action of actin filaments in the release of polar bodies during final oocyte maturation of P. argenteus. PMID:21501616

Arantes, Fábio P; Santos, Hélio B; Rizzo, Elizete; Sato, Yoshimi; Bazzoli, Nilo

2011-07-01

125

Sex steroid hormones exert biphasic effects on cytosolic magnesium ions in cerebral vascular smooth muscle cells: possible relationships to migraine frequency in premenstrual syndromes and stroke incidence.  

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Clinically, it is known that: (1) magnesium (Mg) supplementation relieves premenstrual problems (e.g., migraine, bloating and edema) occurring in the late luteal phase of the menstrual cycle; and (2) migraine syndromes, particularly in women, are associated with deficits in brain and serum ionized Mg levels. We investigated whether concentrations of sex steroid hormones, found in the serum during the menstrual cycle of women, are associated with changes in the levels of cytosolic free magnesium ions ([Mg2+]i in single cultured canine cerebral vascular smooth muscle cells. The resting level of [Mg2+]i in these cells was 645 +/- 89 microM before exposure to sex steroid hormones. Exposure of these vascular cells to a low concentration of estrogen (10 pg/ml) failed to interfere with the levels of [Mg2+]i. However, exposure to estrogen, at concentrations ranging from 40 to 200 pg/ml, induced significant loss of [Mg2+]i in a concentration-dependent manner. At a concentration of 200 pg/ml estrogen, the level of [Mg2+]i decreased approximately 30% in comparison with controls. Progesterone produced biphasic effects on the levels of [Mg2+]i, depending on its concentration. Exposure of the cultured cells to a low concentration of progesterone (0.5 ng/ml) resulted in an increased level of [Mg2+]i (from 690 +/- 50 microM to 753 +/- 56 microM, p hormone, didn't produce any significant alteration in [Mg2+]i levels in these cerebral vascular smooth muscle cells. These data indicate that low, physiological concentrations of female sex hormones, estrogen and progesterone, help cerebral vascular smooth cells sustain normal concentrations of [Mg2+]i, which are beneficial to vascular function, whereas high levels of estrogen and progesterone deplete, significantly, [Mg2+]i in cerebral vascular smooth muscle cells, possibly resulting in cerebrovasospasms and reduced cerebral blood flows related to premenstrual syndromes, migraine and stroke risk. Our findings could provide new insight into the mechanism whereby migraine occurs frequently in the late luteal phase in the premenstrual syndrome. In addition, our results demonstrate that female sex steroids but not testosterone (in physiologic concentrations) can exert direct effects on [Mg2+]i in cerebral vascular cells. PMID:11226717

Li, W; Zheng, T; Altura, B M; Altura, B T

2001-01-01

126

Genes related to sex steroids, neural growth, and social-emotional behavior are associated with autistic traits, empathy, and Asperger syndrome.  

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Genetic studies of autism spectrum conditions (ASC) have mostly focused on the "low functioning" severe clinical subgroup, treating it as a rare disorder. However, ASC is now thought to be relatively common ( approximately 1%), and representing one end of a quasi-normal distribution of autistic traits in the general population. Here we report a study of common genetic variation in candidate genes associated with autistic traits and Asperger syndrome (AS). We tested single nucleotide polymorphisms in 68 candidate genes in three functional groups (sex steroid synthesis/transport, neural connectivity, and social-emotional responsivity) in two experiments. These were (a) an association study of relevant behavioral traits (the Empathy Quotient (EQ), the Autism Spectrum Quotient (AQ)) in a population sample (n=349); and (b) a case-control association study on a sample of people with AS, a "high-functioning" subgroup of ASC (n=174). 27 genes showed a nominally significant association with autistic traits and/or ASC diagnosis. Of these, 19 genes showed nominally significant association with AQ/EQ. In the sex steroid group, this included ESR2 and CYP11B1. In the neural connectivity group, this included HOXA1, NTRK1, and NLGN4X. In the socio-responsivity behavior group, this included MAOB, AVPR1B, and WFS1. Fourteen genes showed nominally significant association with AS. In the sex steroid group, this included CYP17A1 and CYP19A1. In the socio-emotional behavior group, this included OXT. Six genes were nominally associated in both experiments, providing a partial replication. Eleven genes survived family wise error rate (FWER) correction using permutations across both experiments, which is greater than would be expected by chance. CYP11B1 and NTRK1 emerged as significantly associated genes in both experiments, after FWER correction (P<0.05). This is the first candidate-gene association study of AS and of autistic traits. The most promising candidate genes require independent replication and fine mapping. PMID:19598235

Chakrabarti, B; Dudbridge, F; Kent, L; Wheelwright, S; Hill-Cawthorne, G; Allison, C; Banerjee-Basu, S; Baron-Cohen, S

2009-06-01

127

Measurement of steroid hormones in saliva: Effects of sample storage condition.  

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Measurement of steroid hormones in saliva is increasingly common in elite sport settings. However, this environment may enforce handling and storage practices that introduce error in measurement of hormone concentrations. We assessed the influence of storage temperature and duration on reproducibility of salivary steroid levels. Nine healthy adults provided morning and afternoon saliva samples on two separate occasions. Each sample was divided into identical saliva aliquots which were stored long-term (i.e. 28 and 84 days) at - 80°C or - 20°C (testing day 1), and short-term (i.e. 1, 3, 7 and 14 days) at 4°C or 20°C (testing day 2). Samples were analyzed for cortisol, testosterone and estradiol using ELISA. In non-freezer conditions, there was a decrease from baseline to 7 days in testosterone (- 26 ± 15%) and estradiol (- 58 ± 17%) but not cortisol concentrations (p cortisol, testosterone and estradiol should be frozen at - 20°C or below within 24 h of collection, and analyzed within 28 days. Storage of samples for measurement of testosterone and estradiol at temperatures above - 20°C can introduce large error variance to measured concentrations. PMID:24033227

Toone, Rebecca J; Peacock, Oliver J; Smith, Alan A; Thompson, Dylan; Drawer, Scott; Cook, Christian; Stokes, Keith A

2013-12-01

128

Flow cytometric measurement of DNA level and steroid hormone receptor assay in breast cancer  

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DNA level measured by flow cytometry and estrogen and progesteron receptors assayed in tissue samples obtained from 85 malignant and 16 benign lesions of the breast. All the benign tumors revealed 2c DNA content and most of them were receptor-negative, while 74.1% of breast carcinomas displayed aneuploidy. Three patients (3.5%) had two lines of aneuploid cells. Many aneuploid tumors were receptor-negative. Preoperative radiation treatmet (14-20 Gy) did not significantly influence the level of steroid hormone receptors in tumors. Estrogen receptor level was higher in menopausal patients than in premenopausal ones

129

Sex-specific effect of the anabolic steroid, 17?-methyltestosterone, on inhibitory avoidance learning in periadolescent rats  

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The illicit use of anabolic androgenic steroids (AAS) has gained popularity among adolescents in the last decade. However, although it is known that exposure to AAS impairs cognition in adult animal models, the cognitive effects during adolescence remain undetermined. An inhibitory avoidance task (IAT) was used to assess the effect of AAS (17?-methyltestosterone; 17?-meT-7.5 mg/kg) in male and female periadolescent rats. A single injection of 17?-meT immediately before the footshock produc...

Ramos-pratts, Keyla; Rosa-gonza?lez, Dariana; Pe?rez-acevedo, Nivia L.; Cintro?n-lo?pez, Dahima; Barreto-estrada, Jennifer L.

2013-01-01

130

Assessment of spermatogenesis and plasma sex steroids in a seasonal breeding teleost: a comparative study in an area of influence of a tributary, downstream from a hydroelectric power dam, Brazil.  

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River damming and building of hydroelectric power plants interrupt the reproductive migration routes and change the major physicochemical parameters of water quality, with drastic consequences for populations of migratory fishes. The goal of this study was to evaluate proliferation and cell death during spermatogenesis and serum profiles of sex steroids in Prochilodus argenteus, from the São Francisco River, downstream from the Três Marias Dam. A total of 257 adult males were caught quarterly during a reproductive cycle in two sites: the first 34 km of the river after the dam (site 1) and the second 34-54 km after the dam (site 2), after the confluence with a tributary, the Abaeté River. Seasonal changes in the testicular activity associated with morphometric analyses of germ cells as well as proliferation and testicular apoptosis support a more active spermatogenesis in fish from site 2, where higher levels of sex steroids and gonadosomatic index (GSI) were also found. In site 1, fish presented low serum levels of testosterone, 17?-estradiol and 17?-hydroxyprogesterone and a low GSI during gonadal maturation. Spermatogonial proliferation (PCNA) and apoptosis (TUNEL) were more elevated in fish from site 1, but spermatocytes were mainly labelled in fish from site 2. Overall, these data demonstrate changes in testicular activity and plasma sex steroids in a neotropical teleost fish living downstream from a hydroelectric dam, supplying new data on fish reproduction in regulated rivers. Moreover, morphometric analyses associated with sex steroids profiles provide reliable tools to assess fish spermatogenesis under environmental stress conditions. PMID:22688450

Domingos, Fabricio F T; Thomé, Ralph G; Arantes, Fabio P; Castro, Antonio Carlos S; Sato, Yoshimi; Bazzoli, Nilo; Rizzo, Elizete

2012-12-01

131

Expression analysis of cyp11a1 during gonadal development, recrudescence and after hCG induction and sex steroid analog treatment in the catfish, Clarias batrachus.  

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In teleosts, the levels of steroids are critical for sexual development and hence, expression of steroidogenic enzyme genes and specific substrate availability are indispensable for gonadal steroidogenesis. Early stages of steroidogenesis specifically cholesterol to pregnenolone conversion by Cyp11a1 is crucial for estradiol and testosterone biosynthesis. Based on this, in this study, full length cDNA of cyp11a1 (2581bp) was cloned from catfish testis to investigate the importance of Cyp11a1 by analyzing the expression of cyp11a1 during gonadal development, seasonal reproductive cycle, after human chorionic gonadotropin (hCG) induction and sex steroid analog treatment. Phylogenetic analysis revealed that the Cyp11a1 is more conserved across teleosts. Tissue distribution analysis showed that the cyp11a1 expression was higher in the testis followed by the brain, head kidney, muscle and ovary compared to other tissues analyzed. High expression of cyp11a1 in the head kidney and muscle revealed that Cyp11a1 could potentially regulate the extra-gonadal and/or circulating steroid levels in teleosts. Developing and mature testes showed higher expression of cyp11a1 than the ovary of corresponding age group. Further, cyp11a1 expression was found to be higher during pre-spawning and spawning phases of testicular cycle and was upregulated by hCG, in vivo and in vitro, which indicates the possible regulation by gonadotropin. Exposure of methyltestosterone (1?g/L) and ethinylestradiol (1?g/L) for 21days during catfish testicular development showed lower cyp11a1 expression levels in the testis and brain indicating a certain feedback intervention. These results suggest possible role for Cyp11a1 in the testis development and recrudescence. PMID:25107325

Rajakumar, Anbazhagan; Senthilkumaran, Balasubramanian

2014-10-01

132

Standardization of androstenedione and estrone radioimmunoassay and profile of sex steroids, gonadotropins and prolactin - in patients with chronic anovulation due to inappropriate feedback (polycystic ovarian syndrome)  

International Nuclear Information System (INIS)

Full text. In order to evaluate the profile of the sex steroids gonadotropin and prolactin in polycystic ovarian syndrome (POS), 24 patients with POS were studied and compared with 20 normal women during the early follicular phase of the menstrual cycle. Radioimmunoassay techniques for androstenedione (A) and estrone (E1) were standardized for the purpose of the study. Androstenedione and estrone were extracted from plasma with ethyl ether. The assays were maintained in equilibrium and the labelled hormone-antibody complex was then separated from the free hormone using dextran charcoal. The sensitivity of the method was 6.8 pg/tube for A and 3.7 pg/tube for E1. Nonspecific binding ws 3.4 for A and 3.3 for E1. The interessay error at the D50 level was 15.6 for A and 8.6 for E1. Patients with POS had significantly higher basal levels of LH, A, T E1 and PRL and similar FSH and DHEA-S levels when compared with normal women. The LH/FSH ratio was significantly elevated and the A/T ratio was significantly decreased. The A/E1 and T/E2 ratios were elevated and the E1/E2 was decreased, although the differences were not statistically significant. A positive correlation between A and E1 was observed in patients with POS. In view of the above data, it was concluded that: the quality control parameters of the radioimmunoassay for A and E1 standardized in the presand E1 standardized in the present study are considered satisfactory, and the assay could be used for diagnosis and research; the patients with POS have a different sex steroid and gonadotropin profile when compared normal women during the early follicular phase of the menstrual cycle

133

Brief exposure of embryos to steroids or aromatase inhibitor induces sex reversal in Nile tilapia (Oreochromis niloticus).  

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This study aimed to develop sex reversal procedures targeting the embryonic period as tools to study the early steps of sex differentiation in Nile tilapia with XX, XY, and YY sexual genotypes. XX eggs were exposed to masculinizing treatments with androgens (17?-methyltestosterone, 11-ketotestosterone) or aromatase inhibitor (Fadrozole), whereas XY and YY eggs were subjected to feminizing treatments with estrogen analog (17?-ethynylestradiol). All treatments consisted of a single or double 4-hr immersion applied between 1 and 36 hour post-fertilization (hpf). Concentrations of active substances were 1000 or 2000 ?g l(-1) in XX and XY, and 2000 or 6500 ?g l(-1) in YY. Masculinizing treatments of XX embryos achieved a maximal sex reversal rate of 10% with an exposure at 24 hpf to 1000 ?g l(-1) of 11-ketotestosterone or to 2000 ?g l(-1) of Fadrozole. Feminization of XY embryos was more efficient and induced up to 91% sex reversal with an exposure to 2000 ?g l(-1) of 17?-ethynylestradiol. Interestingly, similar treatments failed to reverse YY fish to females, suggesting either that a sex determinant linked to the Y chromosome prevents the female pathway when present in two copies, or that a gene present on the X chromosome is needed for the development of a female phenotype. PMID:25376842

Gennotte, Vincent; Mafwila Kinkela, Patrick; Ulysse, Bernard; Akian Djétouan, Dieudonné; Bere Sompagnimdi, Frédéric; Tomson, Thomas; Mélard, Charles; Rougeot, Carole

2015-01-01

134

Application of Double Isotope Derivative Dilution Procedures to Steroid Hormone Measurement  

International Nuclear Information System (INIS)

The measurement of the concentration of specific steroid hormones in human peripheral plasma has required the development of sensitive analytical procedures. Of the various analytical techniques available, procedures based on the principle of double isotope derivative dilution have great specificity and precision at low levels, and can be readily applied to the measurement of androgens, oestrogens, progesterone and adrenocortical hormones. In these procedures a known amount of 14C- or 3H-labelled steroid is added to the sample as an internal recovery indicator to account for losses over the various analytical steps. Mass is determined by formation of a labelled derivative of the hormone following reaction with a radioactive reagent of known specific activity. These reagents are usually either 3H- or 35S-labelled. Separation of the various steroid hormones from each other and from the excess radioactivity arising from derivative formation is carried out by chromatography and by further chemical modification of the labelled derivative. The problems of developing a method suitable for the measurement of aldosterone in human peripheral plasma are described, and a comparison made between two methods, one which uses 14C-aldosterone as internal indicator and 3H-acetic anhydride for derivative formation, and another which uses 3H-aldosterone and 35S-tosan (toluene sulphonic acid anhydride). The subsequent modification of the basic 3H-acetic anhydride procedure to enable simultaneous measurement of cortisol, cortisone, corticosterone, desoxycortisol, desoxycorticosterone, dehydroepiandrosterone and testosterone in a single sample are described. The application of these procedures to the measurement of progesterone and oestrone and oestradiol- 178 are also discussed; in particular, the enzymatic reduction of progesterone to enable acetylation, or the use of 35S-pipsyl chloride (p-iodo benzene sulphonyl chloride) for derivative formation. The advantages and disadvantages of this type of methodology are also discussed with particular reference to specificity, accuracy, precision and suitability for routine analytical use. The sensitivity and precision of double isotope methodology is dependent not only on the specific activity of the labelled reagents but also on the performance of the liquid scintillation counting system. Statistical counting errors and an assessment of the precision and reliability of liquid scintillation counting systems used to count samples containing 3H and 14C are described. (author)

135

Reproductive periodicity and steroid hormone profiles in the sex-changing coral-reef fish, Plectropomus leopardus  

Science.gov (United States)

The reproductive biology of coral trout, Plectropomus leopardus, from the Great Barrier Reef (Australia) was investigated by correlating gonadal condition with plasma levels of gonadal steroids. Female fish were found to be regressed from mid-summer to early spring, after which rapid and cyclical increases in gonado-somatic index ( I G), maximum oocyte diameter (MOD) and plasma concentrations of estradiol-17? and testosterone were detected. Male fish, in contrast, commenced recrudescence slightly earlier in winter and responded with less dramatic increases in both I G and plasma concentrations of testosterone and 11-ketotestosterone. The mode of oocyte development was multiple group-synchronous, and cyclical fluctuations in reproductive parameters ( I G, MOD and gonadal steroid concentrations) were synchronized with new-moon lunar phases. It is likely, therefore, that individual P. leopardus have the capacity to spawn on multiple occasions, with lunar periodicity. However, evidence suggests that early bouts of reproduction may be more important in terms of reproductive investment than subsequent bouts later in the same season. It is concluded that patterns of gametogenesis and steroidogenesis in P. leopardus are similar to the patterns displayed by other tropical groupers, suggesting that management regimes and propagation protocols developed for these fishes may also be appropriate for use with P. leopardus.

Frisch, A. J.; McCormick, M. I.; Pankhurst, N. W.

2007-03-01

136

Measures to curb rising sex ratio at birth.  

Science.gov (United States)

This article describes the imbalanced sex ratio in Zhejiang province and Wenling City and government programs established to correct the imbalance. The author conducted interviews with some leading officials of the Zhejiang Provincial Family Planning Committee and of the Wenling City Family Planning Committee in the southern area of the province. The sex ratio is described as more imbalanced in areas with less efficient family planning programs. The rising sex ratio occurs unevenly geographically; northern Zhejiang has more balanced ratios. An examination by officials of the underlying causes for the high sex ratios at birth uncovered the misuse of ultrasound scanning in early pregnancy. In Wenling City the Family Planning and Public Health Department maintains strict control of its 51 scanning machines. However, in Yueqing City in Wenzhou Prefecture, which is adjacent to Wenling City, private doctors purchase their own machines. Illegal scanning of fetuses is reported by mothers from Wenling City who visit doctors in Yueqing City. An obstacle to control of misuse of ultrasound scanning to detect the sex of the fetus is the considerable wealth of families who can afford to visit a private doctor. Wenling City has conducted IEC campaigns to inform the public about the importance of valuing boys and girls equally. Information is disseminated through the news media and in county and township schools. Disciplinary sanctions based on local regulations apply to misuse of machines for sex identification. Social insurance programs for the aged are also being provided in the city. Support for social insurance comes from families based on the size of the family and from government revenues. During 1993-95 the sex ratio declined, and the downturn is attributed to the aforementioned measures taken in Wenling City. PMID:12290274

Zhu, H

1995-08-01

137

Transcripts involved in steroid biosynthesis and steroid receptor signaling are expressed early in development in the fathead minnow (Pimephales promelas).  

Science.gov (United States)

Sex differentiation in organisms is correlated to sex steroid production and receptor signaling pathways involving androgens and estrogens. Timing of expression is critical, and characterization of sensitive windows is needed to determine how environmental stressors may perturb sex differentiation. The objectives of this study were to determine whether genes related to steroid biosynthesis, steroid receptor signaling, and those related to sex differentiation were expressed in pre-differentiated fathead minnow (FHM) embryos, an ecotoxicological model. Transcripts were measured over two weeks (1day post fertilization (dpf) to 14days), prior to sex differentiation. The first three time points investigated (1, 3, and 5dpf) corresponded to the neurula stage, dorsal swim bladder pigmentation, and pre-hatch. The fourth time point (6dpf) was collected immediately post-hatch and the fifth time point investigated was after 8days of larval growth (14dpf). The majority of transcripts investigated, for example estrogen, androgen, and thyroid receptors as well as steroid biosynthesis transcripts, were expressed within the first 72hours of development; exceptions were star (steroidogenic acute regulatory protein) and cyp19a, which did not have detectable expression until 5dpf (pre-hatch). Transcripts that increased in relative mRNA abundance over the first two weeks of development included ar, dax1, hsd11b2, hsd17b, cyp19a and thra. This study demonstrates that there is early expression of transcripts related to steroid biosynthesis, steroid receptor signaling, and sex differentiation in pre-hatch FHM embryos. Additional studies are required to determine their relative roles in male and female differentiation during these early developmental periods. PMID:25546055

Wood, Richard K; Seidel, Jason S; Martyniuk, Christopher J

2015-04-01

138

NCI: SBIR & STTR - Past Funding Opportunities - Contracts - 230 Synthesis of Stable Isotope-Labeled Steroids as Internal Standards for the Measurement of Endogenous Steroid Hormones in Biologic Samples by Liquid Chromatography - Mass Spectrometry (LC-MS)  

Science.gov (United States)

Although endogenous steroid hormones, specifically estrogens, androgens, and progestogens, are believed to play critical roles in the etiology of breast, endometrial, ovarian, prostate, and possibly other cancers, research has been limited for many years by the absence of sensitive, accurate methods for measuring the absolute concentrations of steroid hormones and their metabolites in serum, urine, and tissue. The assays routinely used by epidemiologists and clinicians have relied on radiobinding kits with poor specificity and sensitivity in biologic matrixes.

139

Differential Expression of Na+/H+-Exchanger (NHE-1, 2, and 4) Proteins and mRNA in Rodent's Uterus under Sex Steroid Effect and at Different Phases of the Oestrous Cycle  

OpenAIRE

Precise uterine fluid pH regulation may involve the Na+/H+-exchanger (NHE). We hypothesized that NHE isoforms are differentially expressed under different sex steroid treatment and at different oestrous cycle phases which may explain the uterine fluid pH changes observed under these conditions. Method. Oestrous cycle phases of intact WKY rats were identified by vaginal smear. Another group of rats was ovariectomized and treated with 0.2??g 17?-oestradiol (E), 4?mg progesterone (P), and ...

Gholami, Khadijeh; Muniandy, Sekaran; Salleh, Naguib

2013-01-01

140

Anabolic Steroids  

Science.gov (United States)

... refer to the following sources on NIDA’s Web site: Research Report: Anabolic Steroid Abuse Health Effects Chart Tags Fact Sheets Parents Students Teachers Steroids (Anabolic) DrugFacts This page was last updated ...

141

Sex steroid levels across the reproductive cycle of female leopard geckos, Eublepharis macularius, from different incubation temperatures.  

Science.gov (United States)

Incubation temperature during embryonic development determines gonadal sex in many reptiles, including the leopard gecko (Eublepharis macularius). In this study, we examined the hormonal and behavioral changes that occur during the reproductive cycle of female leopard geckos from four (i.e., 26, 30, 32.5, and 34 degrees C) incubation temperatures. Controlling for reproductive status, plasma levels of dihydrotestosterone (DHT), testosterone (T), and progesterone (P) varied with incubation temperature but estradiol 17-beta (E2) levels did not. Controlling for the effects of incubation temperature, DHT and T levels were low when females were previtellogenic, increased slightly during early vitellogenesis, increased dramatically during late vitellogenesis (i.e., prior to ovulation), and then decreased to previtellogenic levels after ovulation. In contrast, E2 levels increased gradually from the previtellogenic stage to the early vitellogenic stage, peaked during late vitellogenesis, and decreased to previtellogenic levels after ovulation. Levels of P increased from the previtellogenic stage to the early vitellogenic stage, remained elevated during late vitellogenesis, and then decreased after ovulation. Moreover, we determined that females were not sexually receptive when previtellogenic, were somewhat receptive during early vitellogenesis (approximately 20% receptive), were most receptive during late vitellogenesis (approximately 80% receptive), and were again unreceptive after ovulation. Incubation temperature did not influence receptivity. Overall, these data show that hormone levels and behavior change coordinately during the reproductive cycle. Although incubation temperature has persistent effects on endocrine physiology in adult female leopard geckos, these effects are modest compared to hormonal changes across the reproductive cycle. PMID:10890571

Rhen, T; Sakata, J T; Zeller, M; Crews, D

2000-05-01

142

The effects of female sex steroids on the development of autoimmune thyroiditis in thymectomized and irradiated rats  

International Nuclear Information System (INIS)

Female PVG/c strain rats are more susceptible to induction of autoimmune thyroiditis initiated by thymectomy and irradiation (Tx-X) than similarly treated males. Pre-pubertal ovariectomy further augmented susceptibility. Administration of oestrogen or progesterone to groups of 4 weeks old ovariectomized Tx-X animals over a period of 15 weeks significantly altered induction of this condition. Oestrogen administered repeatedly at dose levels of 1 ?g and 10 ?g/100 g body weight resulted in partial suppression of thyroiditis with a corresponding change in the incidence of antibodies to thyroglobulin. Oestrogen administered by a single implantation had a suppressive effect on the development of autoimmunity in ovariectomized Tx-X females. Oestrogen given by either of these procedures also reduced the incidence of thyroiditis and autoantibody induction in orchidectomized male Tx-X rats. In contrast, repeated administration of progesterone at a dose of 250 mg and 1,500 ?g/100 g body weight appeared to augment levels of autoimmunity. It is concluded that the differential susceptibility to the induction of autoimmunity by thymectomy and irradiation is the direct consequence of sex hormonal influences. The higher incidence of the disease in the female would appear to be determined by the balance between the activity of oestrogen and progesterone which would further appear to have antagonistic influences in this particular situation. (UK))

143

ALTERED SERUM SEX STEROIDS AND VITELLOGENIN INDUCTION IN WALLEYE (STIZOSTEDION VITREUM) COLLECTED NEAR A METROPOLITAN SEWAGE TREATMENT PLANT  

Science.gov (United States)

Feral, male walleye collected from the Mississippi River below the St. Paul metropolitan sewage treatment plant (STP) contained measurable levels of the estrogen-inducible, female egg protein, vitellogenin. These same fish showed significantly decreased serum androgen and signifi...

144

Mutations in exons of the CYP17-II gene affect sex steroid concentration in male Japanese flounder ( Paralichthys olivaceus)  

Science.gov (United States)

As a specific gene of fish, cytochrome P450c17-II ( CYP17-II) gene plays a key role in the growth, development an reproduction level of fish. In this study, the single-stranded conformational polymorphism (SSCP) technique was used to characterize polymorphisms within the coding region of CYP17-II gene in a population of 75 male Japanese flounder ( Paralichthys olivaceus). Three single nucleotide polymorphisms (SNPs) were identified in CYP17-II gene of Japanese flounder. They were c.G594A (p.G188R), c.G939A and c.G1502A (p.G490D). SNP1 (c.G594A), located in exon 4 of CYP17-II gene, was significantly associated with gonadosomatic index (GSI). Individuals with genotype GG of SNP1 had significantly lower GSI ( P mutation changed the methylation of exon 6. Individuals with genotype AA of SNP2 had significantly lower serum testosterone (T) level and hepatosomatic index (HSI) compared to those with genotype GG. The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder. However, the SNP3 (c.G1502A) located in exon 9 did not affect the four measured reproductive traits. This study showed that CYP17-II gene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.

Ma, Ruiqin; He, Feng; Wen, Haishen; Li, Jifang; Shi, Bao; Shi, Dan; Liu, Miao; Mu, Weijie; Zhang, Yuanqing; Hu, Jian; Han, Weiguo; Zhang, Jianan; Wang, Qingqing; Yuan, Yuren; Liu, Qun

2012-03-01

145

Influence of estrus of dairy goats on somatic cell count, milk traits, and sex steroid receptors in the mammary gland.  

Science.gov (United States)

Two experiments were conducted to study the effect of the stage of a spontaneous estrus cycle on milk yield and constituents [somatic cell count (SCC), fat, protein, caseins, lactose, and urea content] and on estrogen receptor-alpha (ERalpha ) and progesterone receptor (PR) immunostaining in the mammary gland. In experiment I, the major components of milk and SCC were monitored weekly in 80 lactating Saanen goats for 6 wk, whereas detection of estrus was daily. In experiment II, milk samples were collected daily for SCC determination during 1 spontaneous estrus (d 0) until the second spontaneous estrus in 14 Saanen goats. The day of the estrous cycle was confirmed by plasma progesterone and 17beta-estradiol levels. Immunoreactivity of ERalpha and PR was analyzed in mammary gland samples of 8 Saanen goats (d 0, n = 4; d 10, n = 4) and the number of positive nuclei and intensity of the staining were evaluated in 1,000 cells. In experiment I, milk casein and protein percentages were significantly affected by the stage of estrous cycle; during proestrus and estrus, these variables were higher (3.32 +/- 0.06 and 4.44 +/- 0.08) than during metestrus (3.03 +/- 0.07 and 4.07 +/- 0.10), but not higher than during diestrus (3.23 +/- 0.06 and 4.35 +/- 0.09, respectively). In experiment II, daily measurement of SCC revealed higher levels at estrus (7,195 +/- 672 x 10(3) cells/mL) and a decline toward the luteal phase (1,694 +/- 672 +/- 10(3) cells/mL). Estrogen receptor-alpha and PR immunostaining were exclusively detected on epithelial cells. The percentage of positive nuclei to ERalpha was higher on d 0 than on d 10 (75.4 +/- 8.8 vs. 68.3 +/- 8.8%), but no change was observed for PR (4.0 +/- 0.3 vs. 3.5 +/- 0.4%). The average immunostaining intensity for both receptors was greater on d 0 than on d 10 (ERalpha : 1.44 +/- 0.02 vs. 1.35 +/- 0.02; PR: 0.079 +/- 0.008 vs. 0.057 +/- 0.008). The high SCC at estrus in experiment II was associated with high plasma estradiol and low progesterone, suggesting that the increased SCC could be brought about by the estrogen-induced proliferation and exfoliation of epithelial cells. In addition, this action may be supported by the higher sensitivity to estrogens (ERalpha content) found at d 0. PMID:17235156

Moroni, P; Pisoni, G; Savoini, G; van Lier, E; Acuña, S; Damián, J P; Meikle, A

2007-02-01

146

Steroid osteopathy  

International Nuclear Information System (INIS)

Patients receiving steroids or having disease processes which increase natural steroid production often demonstrate ''the classic x-ray changes'' of avascular necrosis of bone. Bone scintigraphy in these patients most frequently demonstrates an increased radionuclide localization. The literature suggests that the increased activity is related to healing of the avascular process. In a recent study of Legg-Calve-Perthes Disease (LCPD), 37 of the children had multiple studies and increased activity within the epiphysis during revascularization was extremely rare. Not only are the scintigraphic findings in steroid osteopathy dissimilar to that in healing LCPD, but the time interval for healing is much to short for that of a vascular necrosis and no patients demonstrated an avascular phase on bone scintigraphy. Of 15 children with renal transplants on steroid therapy, 9 demonstrated x-ray and clinical findings of osteopathy. In 8 of 9 instances, bone scintigraphy showed increased localization of radionuclide in the affected bone. Improvement or a return to normal occurred in those patients in whom steroids were discontinued. The following is a proposed mechanism for steroid osteopathy. Steroids affect the osteoblastic and osteoclastic activity of bone and weaken its internal structure. Ordinary stress produces microtrabecular fractures. Fractures characteristically stimulate reactive hyperemia and increase bone metabolism. The result is increased bone radiopharmaceutical llt is increased bone radiopharmaceutical localization. The importance of recognizing this concept is that steroid osteopathy is preventable by reducing the administered steroid dose. As opposed to avascular necrosis, bone changes are reversible

147

Steroid osteopathy  

Energy Technology Data Exchange (ETDEWEB)

Patients receiving steroids or having disease processes which increase natural steroid production often demonstrate ''the classic x-ray changes'' of avascular necrosis of bone. Bone scintigraphy in these patients most frequently demonstrates an increased radionuclide localization. The literature suggests that the increased activity is related to healing of the avascular process. In a recent study of Legg-Calve-Perthes Disease (LCPD), 37 of the children had multiple studies and increased activity within the epiphysis during revascularization was extremely rare. Not only are the scintigraphic findings in steroid osteopathy dissimilar to that in healing LCPD, but the time interval for healing is much to short for that of a vascular necrosis and no patients demonstrated an avascular phase on bone scintigraphy. Of 15 children with renal transplants on steroid therapy, 9 demonstrated x-ray and clinical findings of osteopathy. In 8 of 9 instances, bone scintigraphy showed increased localization of radionuclide in the affected bone. Improvement or a return to normal occurred in those patients in whom steroids were discontinued. The following is a proposed mechanism for steroid osteopathy. Steroids affect the osteoblastic and osteoclastic activity of bone and weaken its internal structure. Ordinary stress produces microtrabecular fractures. Fractures characteristically stimulate reactive hyperemia and increase bone metabolism. The result is increased bone radiopharmaceutical localization. The importance of recognizing this concept is that steroid osteopathy is preventable by reducing the administered steroid dose. As opposed to avascular necrosis, bone changes are reversible.

Conway, J.J.; Weiss, S.C.

1984-01-01

148

Sex steroids and cardiovascular disease.  

Science.gov (United States)

As men grow older, testosterone (T) levels decline and the significance of this change is debated. The evidence supporting a causal role for lower circulating T, or its metabolites dihydrotestosterone (DHT) and estradiol, in the genesis of atherosclerosis and cardiovascular disease (CVD) in men is limited. Observational studies associate low baseline T levels with carotid atherosclerosis, aortic and peripheral vascular disease, and with the incidence of cardiovascular events and mortality. Studies using mass spectrometry suggest that when total T is assayed optimally, calculation of free T might not necessarily improve risk stratification. There is limited evidence to support an association of estradiol with CVD. Interventional studies of T therapy in men with coronary artery disease have shown beneficial effects on exercise-induced myocardial ischemia. However, placebo-controlled, randomized clinical trials (RCTs) of T therapy in men with the prespecified outcomes of cardiovascular events or deaths are lacking. Meta-analyses of randomized controlled trials of T published up to 2010 found no increase in cardiovascular events, mortality, or prostate cancer with therapy. Recently, in a trial of older men with mobility limitations, men randomized to receive a substantial dose of T reported cardiovascular adverse effects. This phenomenon was not reported from a comparable trial where men received a more conservative dose of T, suggesting a prudent approach should be adopted when considering therapy in frail older men with existing CVD. Adequately powered RCTs of T in middle-aged and older men are needed to clarify whether or not hormonal intervention would reduce the incidence of CVD. PMID:24407188

Yeap, Bu Beng

2014-01-01

149

Sex steroids and cardiovascular disease  

Directory of Open Access Journals (Sweden)

Full Text Available As men grow older, testosterone (T levels decline and the significance of this change is debated. The evidence supporting a causal role for lower circulating T, or its metabolites dihydrotestosterone (DHT and estradiol, in the genesis of atherosclerosis and cardiovascular disease (CVD in men is limited. Observational studies associate low baseline T levels with carotid atherosclerosis, aortic and peripheral vascular disease, and with the incidence of cardiovascular events and mortality. Studies using mass spectrometry suggest that when total T is assayed optimally, calculation of free T might not necessarily improve risk stratification. There is limited evidence to support an association of estradiol with CVD. Interventional studies of T therapy in men with coronary artery disease have shown beneficial effects on exercise-induced myocardial ischemia. However, placebo-controlled, randomized clinical trials (RCTs of T therapy in men with the prespecified outcomes of cardiovascular events or deaths are lacking. Meta-analyses of randomized controlled trials of T published up to 2010 found no increase in cardiovascular events, mortality, or prostate cancer with therapy. Recently, in a trial of older men with mobility limitations, men randomized to receive a substantial dose of T reported cardiovascular adverse effects. This phenomenon was not reported from a comparable trial where men received a more conservative dose of T, suggesting a prudent approach should be adopted when considering therapy in frail older men with existing CVD. Adequately powered RCTs of T in middle-aged and older men are needed to clarify whether or not hormonal intervention would reduce the incidence of CVD.

Bu Beng Yeap

2014-04-01

150

Conceptualization and measurement of homosexuality in sex surveys: a critical review  

OpenAIRE

This article reviews major national population sex surveys that have asked questions about homosexuality focusing on conceptual and methodological issues, including the definitions of sex, the measured aspects of homosexuality, sampling and interviewing technique, and questionnaire design. Reported rates of major measures of same-sex attraction, behavior, partners, and sexual identity from surveys are also presented and compared. The study of homosexuality in surveys has been shaped by the re...

Michaels Stuart; Lhomond Brigitte

2006-01-01

151

2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro  

International Nuclear Information System (INIS)

The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1–100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 ?M) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3–4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. -- Highlights: ?TCDD disrupts sex steroid hormone levels, but not growth of antral follicles. ?Pregnenolone co-treatment by-passes TCDD-induced steroid hormone disruption. ?TCDD affects steroid hormone levels through an AHR pathway in antral follicles.

152

Steroid radioimmunoassays  

International Nuclear Information System (INIS)

An estrogen radioimmunoassay was used to study the problem of blanks in steroid assays. Negligible binding (1.5 percent) in the non-antibody tubes prevailed throughout the study. The assay was validated using accepted procedures. Both water and solvent blanks had estrogen concentrations of 7-9 pg/tube. However, neither water nor solvent blanks showed a dose-related response, indicating that they were 'real' blanks. Exogenous estradiol, when added to water and solvent in quantities less than the estimated blank, was not quantitatively recovered. However, exogenous estradiol added to the water solvent in quantities greater than the blank estimate was quantitatively recovered. The sensitivity of the reference standard curve was 6-10 pg/tube, approximately the same as the blank estimate. These results indicated that the estimates of water and solvent blanks were measures of the assay sensitivity. In such circumstances, it is suggested that blank estimates should not be subtracted from sample values. If the blank estimates are high, attention should be directed towards improving the sensitivity of the assay

153

Extensive esterification of adrenal C19-delta 5-sex steroids to long-chain fatty acids in the ZR-75-1 human breast cancer cell line  

International Nuclear Information System (INIS)

Estrogen-sensitive human breast cancer cells (ZR-75-1) were incubated with the 3H-labeled adrenal C19-delta 5-steroids dehydroepiandrosterone (DHEA) and its fully estrogenic derivative, androst-5-ene-3 beta,17 beta-diol (delta 5-diol) for various time intervals. When fractionated by solvent partition, Sephadex LH-20 column chromatography and silica gel TLC, the labeled cell components were largely present (40-75%) in three highly nonpolar, lipoidal fractions. Mild alkaline hydrolysis of these lipoidal derivatives yielded either free 3H-labeled DHEA or delta 5-diol. The three lipoidal fractions cochromatographed with the synthetic DHEA 3 beta-esters, delta 5-diol 3 beta (or 17 beta)-monoesters and delta 5-diol 3 beta,17 beta-diesters of long-chain fatty acids. DHEA and delta 5-diol were mainly esterified to saturated and mono-unsaturated fatty acids. For delta 5-diol, the preferred site of esterification of the fatty acids is the 3 beta-position while some esterification also takes place at the 17 beta-position. Time course studies show that ZR-75-1 cells accumulate delta 5-diol mostly (greater than 95%) as fatty acid mono- and diesters while DHEA is converted to delta 5-diol essentially as the esterified form. Furthermore, while free C19-delta 5-steroids rapidly diffuse out of the cells after removal of the precursor [3H]delta 5-diol, the fatty acid ester derivatives are progressively hydrolyzed, and DHEA and delta 5-diol thus formed are then sulfurylated prior to the formed are then sulfurylated prior to their release into the culture medium. The latter process however is rate-limited, since new steady-state levels of free steroids and fatty acid esters are rapidly reached and maintained for extended periods of time after removal of precursor, thus maintaining minimal concentrations of intracellular steroids

154

Steroids (For Parents)  

Science.gov (United States)

... your child isn't at risk. What Are Steroids? Drugs commonly referred to as "steroids" are classified ... number of health problems. Continue How Do Anabolic Steroids Work? Anabolic steroids are drugs that resemble the ...

155

External calibration in gas chromatography-combustion-isotope ratio mass spectrometry measurements of endogenous androgenic anabolic steroids in sports doping control.  

Science.gov (United States)

An alternative calibration procedure for the gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) measurements of the World Antidoping Agency (WADA) Accredited Laboratories is presented. To alleviate the need for externally calibrated CO? gas for GC-C-IRMS analysis of urinary steroid metabolites, calibration using an external standard mixture solution of steroids with certified isotopic composition was investigated. The reference steroids of the calibration mixture and routine samples underwent identical instrumental processes. The calibration standards bracketed the entire range of the relevant ?¹³C values for the endogenous and exogenous steroids as well as their chromatographic retention times. The certified ?¹³C values of the reference calibrators were plotted in relation to measured m/z ¹³CO?/¹²CO? (i.e. R(45/44)) mass spectrometric signals of each calibrator. ?¹³C values of the sample steroids were calculated from the least squares fit through the calibration curve. The effect of the external calibration on ?¹³C values, using the same calibration standards and set of urine samples but different brands of GC-C-IRMS instruments, was assessed by an interlaboratory study in the WADA Accredited Laboratories of Sydney, Australia and Athens, Greece. Relative correspondence between the laboratories for determination of androsterone, etiocholanolone, 5?-androstane-3?,17?-diacetate, and pregnanediacetate means were SD(?¹³C)=0.12‰, 0.58‰, -0.34‰, and -0.40‰, respectively. These data demonstrate that accurate intralaboratory external calibration with certified steroids provided by United States Antidoping Agency (USADA) and without external CO? calibration is feasible and directly applicable to the WADA Accredited Laboratories for the harmonization of the GC-C-IRMS measurements. PMID:21752385

Kioussi, Maroula K; Angelis, Yiannis S; Cawley, Adam T; Koupparis, Michalis; Kazlauskas, Rymantas; Brenna, J Thomas; Georgakopoulos, Costas G

2011-08-19

156

A dual estrogen receptor TR-FRET assay for simultaneous measurement of steroid site binding and coactivator recruitment.  

Science.gov (United States)

The human estrogen receptors (hER) are members of the nuclear hormone receptor (NHR) superfamily and represent important drug targets for the pharmaceutical industry. Initially, ligand binding assays were used to identify novel ligands using receptors purified from native tissues. With the advent of molecular cloning techniques, cell-based transactivation assays have been the gold standard for many years of drug discovery. With the elucidation of the structural mechanisms underlying the activation of NHRs, cell-free assays with purified receptors have become important tools to directly assess different binding sites (e.g., the hormone binding site or the cofactor binding site). The available cell-free assays have so far facilitated the study of one binding site at a time. With the introduction of Terbium (Tb(3+))-based time-resolved fluorescence energy transfer (TR-FRET), it has become possible to measure 2 different interactions within 1 test tube in parallel. The authors have applied this technology to develop a dual readout system for the simultaneous monitoring of steroid hormone site binding and cofactor peptide recruitment. They took advantage of a commercially available fluorescent tracer as an indicator for classical steroid site binding and designed a novel peptide derived from the peroxisome proliferator-activated receptor gamma coactivator-1a (PGC1a) as an indicator for functional agonistic behavior of a test compound. The established assay is able to differentiate between agonists, antagonists, partial agonists, and compounds binding to the cofactor recruitment site. The IC(50) values obtained for a number of reference compounds in the multiplexed assay are in concordance with published data. The simple 1-step mix-and-measure protocol gives excellent quality and robustness and can be miniaturized to 5-microL volume. PMID:20150592

Hilal, Tarek; Puetter, Vera; Otto, Christiane; Parczyk, Karsten; Bader, Benjamin

2010-03-01

157

Are there sex differences in Fetal Abdominal Subcutaneous Tissue (FAST) measurements?  

LENUS (Irish Health Repository)

OBJECTIVE: To determine if Fetal Abdominal Subcutaneous Tissue (FAST) measurements using antenatal ultrasound differ between male and female fetuses. STUDY DESIGN: Women who had an ultrasound examination for fetal growth between 20 and 40 weeks gestation were studied. Women with diabetes mellitus were excluded. The fetal anterior abdominal subcutaneous tissue was measured on the anterior abdominal wall in millimetres anterior to the margins of the ribs, using magnification at the level of the abdominal circumference. The fetal sex was recorded after delivery. RESULTS: A total of 557 fetuses were measured, 290 male and 267 female. The FAST measurements increased with gestational age. The FAST increased at the same rate for both male and female fetuses and at any given week there was no sex difference. CONCLUSIONS: The increased fat composition in females reported after birth was not found in abdominal wall subcutaneous fat measurements using ultrasound during pregnancy. Antenatal centile charts for FAST do not need to be based on sex.

Farah, Nadine

2012-02-01

158

Estradiol stimulation of Pulsatile gonadotropin-releasing hormone secretion in vitro: Correlation with perinatal exposure to sex steroids and induction of sexual precocity in vivo  

OpenAIRE

Our aim was to study the effect of estradiol (E2) on pulsatile GnRH secretion in vitro in relation to sex and development. When hypothalamic explants obtained from 5- and 15-d-old female rats were exposed to E2 (10(-7) m), a reduction of GnRH interpulse interval (IPI) occurred but not at 25 and 50 d of age. This effect was prevented by the estrogen receptor antagonist ICI 182.780 and the AMPA/kainate receptor antagonist DNQX but not by the AMPA and N-methyl-D-aspartate receptor antagonists SY...

Matagne, V.; Rasier, G.; Lebrethon, Marie-christine; Gerard, Arlette; Bourguignon, Jean-pierre

2004-01-01

159

Flow Cytometry as a Tool for Measurement of Steroid Hormone Receptor Protein Expression in Leukocytes  

OpenAIRE

Measurement of protein expression in live, intact cells using flow cytometry (FC) has been employed for several decades in the areas of immunology, cell biology, and molecular biology. More recently, this technique has found appreciation in applied scientific fields, including cancer biology and endocrinology, to serve as a tool for identifying cells more likely to respond to specific treatments. FC, also referred to as fluorescence-activated cell sorting (FACS), is an antibody-based method t...

Butts, Cherie L.; Sternberg, Esther M.

2009-01-01

160

The essence of female-male physiological dimorphism: differential Ca2+-homeostasis enabled by the interplay between farnesol-like endogenous sesquiterpenoids and sex-steroids? The Calcigender paradigm.  

Science.gov (United States)

Ca(2+) is the most omnipresent pollutant on earth, in higher concentrations a real threat to all living cells. When [Ca(2+)]i rises above 100 nM (=resting level), excess Ca(2+) needs to be confined in the SER and mitochondria, or extruded by the different Ca(2+)-ATPases. The evolutionary origin of eggs and sperm cells has a crucial, yet often overlooked link with Ca(2+)-homeostasis. Because there is no goal whatsoever in evolution, gametes did neither originate "with the purpose" of generating a progeny nor of increasing fitness by introducing meiosis. The explanation may simply be that females "invented the trick" to extrude eggs from their body as an escape strategy for getting rid of toxic excess Ca(2+) resulting from a sex-hormone driven increased influx into particular cells and tissues. The production of Ca(2+)-rich milk, seminal fluid in males and all secreted proteins by eukaryotic cells may be similarly explained. This view necessitates an upgrade of the role of the RER-Golgi system in extruding Ca(2+). In the context of insect metamorphosis, it has recently been (re)discovered that (some isoforms of) Ca(2+)-ATPases act as membrane receptors for some types of lipophilic ligands, in particular for endogenous farnesol-like sesquiterpenoids (FLS) and, perhaps, for some steroid hormones as well. A novel paradigm, tentatively named "Calcigender" emerges. Its essence is: gender-specific physiotypes ensue from differential Ca(2+)-homeostasis enabled by genetic differences, farnesol/FLS and sex hormones. Apparently the body of reproducing females gets temporarily more poisoned by Ca(2+) than the male one, a selective benefit rather than a disadvantage. PMID:25540913

De Loof, Arnold

2015-01-15

161

Expression of integrin alpha5 and integrin beta4 and their extracellular ligands fibronectin and laminin in human decidua during early pregnancy and its sex steroid-mediated regulation.  

Science.gov (United States)

The reorganization of the human endometrium is termed decidualization, which includes endometrial cell proliferation, differentiation, integrin switching and extracellular matrix (ECM) remodeling during early pregnancy. The present study aimed to investigate distribution patterns, staining intensity and sex steroid-mediated regulation of integrin alpha5 (CD49e), integrin beta4 (CD49f) expression and their ligands fibronectin and laminin during decidualization. Human tissue samples were evaluated in two groups, those collected in early days and those collected in advanced days of the first trimester. Correlating immunostaining was found between laminin and integrin beta4, and between fibronectin and integrin alpha5. The expression of fibronectin was higher than that of laminin in the early days (p endometrial stromal cells in culture. Our results suggest that fibronectin is responsible for induction of decidual cell differentiation, and different temporal and spatial expression of the integrins may play a role in implantation. Our in vitro results suggest that regulation of extracellular matrix remodeling and integrin switching are at least partially regulated by reproductive hormones. PMID:15964615

Kayisli, Umit A; Korgun, Emin T; Akkoyunlu, Gokhan; Arici, Aydin; Demir, Ramazan

2005-01-01

162

The alteration of the urinary steroid profile under the stress  

OpenAIRE

In the second part of twentieth century anabolic-androgenic steroids were introduced into doping practice and received continuously increasing significance. In order to prove the usage of doping substances, the determination of steroid profile in the urine came into practice. Several factors may be responsible for alterations in the normal steroid profile for example age, sex and diet. The aim of this study was to find out, whether the psychological stress may cause modifications in the stero...

Gronowska, A.; Kwiatkowska, D.; Pokrywka, A.; Koteras, M.; Turek-lepa, E.; Szutowski, M.

2010-01-01

163

Age and sex differences in estimated tibia strength: influence of measurement site  

Science.gov (United States)

Variability in peripheral Quantitative Computed Tomography (pQCT) measurement sites and outcome variables limit direct comparisons of results between studies. Further, it is unclear what estimates of bone strength are most indicative of changes due to aging, disease, or interventions. The purpose of this study was to examine age and sex differences in estimates of tibia strength. An additional purpose of this study was to determine which tibia site or sites are most sensitive for detecting age and sex differences in tibia strength. Methods Self-identifying Caucasian men (n=55) and women (n=59) ages 20–59 years had their tibias measured with pQCT from 5%–85% of limb length in 10% increments distal to proximal. Bone strength index (BSI), strength strain index (SSI), moments of inertia (Ip, Imax, Imin), and strength-to-mass ratios (Ip:Tot.BMC, SSIp:Tot.BMC) were quantified. Results There were significant (p<0.01) site effects for all strength variables and strength to mass ratios. Site*sex interaction effects were significant (p<0.05) for all strength variables. Men had greater (p<0.01) values than women for all strength variables. Sex differences in Ip, Imax, Ip:Tot.BMC, SSI, and SSI:Tot.BMC ratio were smallest at the 15% site and peaked at various sites, depending on variable. Site*age interactions existed for Imax, Ip:Tot.BMC, and SSI:Tot.BMC. There were significant age effects Imax, Ip:Tot.BMC and SSI:Tot.BMC, as values were lowest in the 20–29 age group. Conclusion Age and sex differences varied by measurement site and variable and larger sex differences existed for moments of inertia than SSI. Strength-to-mass ratios may reflect efficiency of the whole bone architecture. PMID:22677196

Sherk, Vanessa D.; Bemben, Debra A.

2014-01-01

164

Measurement of Serum Leptin Concentrations in University Undergraduates by Competitive Elisa Reveals Correlations With Body Mass Index and Sex  

Science.gov (United States)

Synthesized mainly in adipocytes, leptin is a peptide hormone that plays a key role in the regulation of body weight and composition. The serum leptin concentrations of 193 Singapore university medical and bioscience undergraduates aged 19Â?26 yr were measured using a competitive ELISA kit, and their leptin levels were correlated with sex and body mass index (BMI). Mean leptin levels were more than twice as high in females than in males of corresponding weight status, especially among females of healthy weight who exhibited levels that were 5.7 times higher. Overweight individuals generally demonstrated higher circulating leptin concentrations than healthy-weight and underweight participants. The differences in mean leptin levels between underweight and overweight males (P = 0.006), as well as between healthy-weight and overweight males (P = 0.011) were statistically significant. Comparison tests of leptin levels between healthy-weight and underweight females were highly significant (P = 0.001). Highly significant linear correlations between BMI and the logarithm of leptin concentration were observed in the female (r = 0.44) and male (r = 0.36) groups. These results reiterate the impact of gonadal steroids as mediators of the apparent sexual dimorphism in circulating leptin. The findings also corroborate evidence that adiposity determines leptin levels. This laboratory exercise has educational value for undergraduates by determining their BMIs, by alluding to the importance of maintaining healthy body composition, and by emphasizing the molecular mechanisms of body weight regulation and obesity, with special reference to leptin. This practical study also exemplifies the principles and applications of the competitive ELISA technique and integrates certain key concepts of physiology, molecular biology, immunology, and medicine.

Dr. Vincent T. K. Chow (National University of Singapore Faculty of Medicine Department of Microbiology)

2003-06-01

165

An interlaboratory study measuring sex steroids with RIAs and/or ELISAs: Are we comparing apples to oranges?  

Science.gov (United States)

Endocrine-disrupting chemicals (EDCs) are exogenous substances released into the environment that can lead to adverse reproductive effects in fish by a number of mechanisms including altering circulating levels of estradiol (E2), testosterone (T) and 11-ketotestosterone (11KT). ...

166

Adolescent Steroid Use.  

Science.gov (United States)

The study focused on non-medical steroid use by adolescents according to data obtained from the National Institute on Drug Abuse, professional literature, 30 key informants knowledgeable in steroid issues, and 72 current or former steroid users. The findings indicated: (1) over 250,000 adolescents, primarily males, used or have used steroids, and…

Office of Inspector General (DHHS), Washington, DC.

167

Differentiation of subspecies and sexes of Beringian Dunlins using morphometric measures  

Science.gov (United States)

Five subspecies of Dunlins (Calidris alpina) that breed in Beringia are potentially sympatric during the non-breeding season. Studying their ecology during this period requires techniques to distinguish individuals by subspecies. Our objectives were to determine (1) if five morphometric measures (body mass, culmen, head, tarsus, and wing chord) differed between sexes and among subspecies (C. a. actites, arcticola, kistchinski, pacifica, and sakhalina), and (2) if these differences were sufficient to allow for correct classification of individuals using equations derived from discriminant function analyses. We conducted analyses using morphometric data from 10 Dunlin populations breeding in northern Russia and Alaska, USA. Univariate tests revealed significant differences between sexes in most morphometric traits of all subspecies, and discriminant function equations predicted the sex of individuals with an accuracy of 83–100% for each subspecies. We provide equations to determine sex and subspecies of individuals in mixed subspecies groups, including the (1) Western Alaska group of arcticola and pacifica (known to stage together in western Alaska) and (2) East Asia group of arcticola, actites, kistchinski, and sakhalina (known to winter together in East Asia). Equations that predict the sex of individuals in mixed groups had classification accuracies between 75% and 87%, yielding reliable classification equations. We also provide equations that predict the subspecies of individuals with an accuracy of 22–96% for different mixed subspecies groups. When the sex of individuals can be predetermined, the accuracy of these equations is increased substantially. Investigators are cautioned to consider limitations due to age and feather wear when using these equations during the non-breeding season. These equations will allow determination of sexual and subspecies segregation in non-breeding areas, allowing implementation of taxonomic-specific conservation actions.

Gates, H. River; Yezerinac, Stephen; Powell, Abby N.; Tomkovich, Pavel S.; Valchuk, Olga P.; Lanctot, Richard B.

2013-01-01

168

Assessing Invariance Across Sex and Race/Ethnicity in Measures of Youth Psychopathic Characteristics.  

Science.gov (United States)

The aim of this study was to assess the measurement invariance of 2 commonly used measures of youth psychopathic characteristics across sex and racial/ethnic groups. Among a community sample of Hispanic and Black adolescents (N = 355; 50.5% female; mean age = 15.09) and their parents, this study tested the configural and metric invariance of the Levenson Self-Report Psychopathy Scale (LSRP; Levenson, Fitzpatrick, & Kiehl, 1995) and the parent-report version of the Inventory of Callous-Unemotional Traits (Frick, 2004). Preliminary analyses indicated that the adolescents in the present study reported similar rates of psychopathic characteristics as those reported by other studies of adolescents and young adults. Results of the multigroup invariance analyses indicated that these measures are invariant across sex and between Hispanic and Black youth. In addition, further analyses assessing associations between these measures and a number of behavioral and emotional characteristics indicated that scores on the LSRP Scale and Callous-Unemotional Traits demonstrate good convergent and discriminant validity with few differences by sex or race/ethnicity. To date, research on psychopathy has focused predominantly on samples of White males. Therefore, it is important that research examines the equivalence of measures of psychopathic characteristics across different populations, so that accurate assessments can be made to inform intervention and treatment efforts. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25383582

Horan, Jacqueline M; Brown, Joshua L; Jones, Stephanie M; Aber, J Lawrence

2014-11-10

169

Copy-number variations (CNVs) of the human sex steroid metabolizing genes UGT2B17 and UGT2B28 and their associations with a UGT2B15 functional polymorphism.  

Science.gov (United States)

UGT2B17 and UGT2B28 are among the most commonly deleted genes in humans and encode members of the uridine diphosphate (UDP)-glucuronosyltransferase 2B (UGT2B) subfamily. They are involved, along with UGT2B15, in the catabolism of sex-steroid hormones. Despite the recent biomedical interest in UGT2B17 and UGT2B28 copy-number variations (CNVs) within human populations, the impact of their gene dosage has been hampered by the lack of precise molecular identification of the common deletion breakpoints within high homology sequence regions on chromosome 4. We have characterized these common deletions and report their coexistence in Caucasians, along with the p.D85Y (rs1902023:G>T) functional polymorphism of UGT2B15. Segmental duplications of 4.9 kb for UGT2B17 and 6.8 kb for UGT2B28 comprise purine-rich recombination sites located 117 kb and 108 kb apart on both ends of the deletions. CNVs of UGT2B17 and UGT2B28 occur in Caucasians at 27% and 13.5%, respectively. While only 43% have two copies of both genes, 57% harbor at least one deletion. Their co-occurrence on 5% of chromosomes creates a 225-kb genomic gap. CNVs of both UGT2B17 and UGT2B28, with the co-occurrence of UGT2B15:p.D85Y, generate seven distinct haplotypes. Restricting the analyses to CNV of the UGT2B17 gene without evaluating UGT2B28 CNV, along with the genotype of UGT2B15, may over- or underestimate the impact of each gene under physiological conditions or disease states. PMID:19572376

Ménard, Vincent; Eap, Olivier; Harvey, Mario; Guillemette, Chantal; Lévesque, Eric

2009-09-01

170

Sex and individual differences in induced and evoked EEG measures of action observation.  

Science.gov (United States)

We used two established methods for analysing the EEG response of the neurotypical adult human brain to examine the execution and observation of simple motor actions. In one, execution or observation of a button-press in response to a tone caused a decrease in the power at 8-13 Hz ("mu") frequencies. In the other, the response preparation (or the inferred response preparation when these actions are observed in another person) was measured by the averaged response time-locked potentials measured over motor cortex--the "readiness potential". Results indicated that the mirrored readiness potentials were bilaterally generated. We found sex differences for both measures. However, whereas females showed a greater degree of response for the mu power measure during the observation of movement only, males showed larger readiness potentials during both movement performance and observation. Both measures have been claimed to be neural correlates of mirror systems in the brain where processes responsible for actions are linked to the perception of such actions. Such mirror systems have also been implicated in higher order social cognition such as empathy. However, we found no correlations between either of our EEG measures and self-report scales of social cognition. The results imply sex differences in the measured systems and for mirroring that are not directly related to social cognition. We suggest that the results may indicate two dissociable motor mirroring systems that can be measured by induced and evoked EEG. PMID:20226800

Silas, Jonathan; Levy, Joseph P; Nielsen, Maria Kragh; Slade, Lance; Holmes, Amanda

2010-07-01

171

Steroid profiling and confirmation of the T/E - ratio in doping control  

OpenAIRE

Anabolic-androgenic steroids are naturally occurring or synthetic derivates of male sex hormones. All anabolic-androgenic steroids are prohibited by the World Anti-Doping Agency because of their muscle growth stimulating effect. At the Seibersdorf Doping-Control Laboratory, urine samples from athletes are first screened with a screen testing procedure to obtain an endogenous steroid profile, in order to identify samples suspected of containing endogenous steroids of exogenous origin. This i...

Hanssen, Kine Østnes

2010-01-01

172

[Mass spectrometry for steroid assays].  

Science.gov (United States)

Steroid hormone measurement, first developed with radioimmunoassay, is now becoming easier with the use of automated platforms of immunoassay. However, some hormones remain uneasily detectable because of their low blood concentration, their structural homology or the presence of interferences. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be considered as an alternative to immunoassays. This approach allows the simultaneous determination of several parameters thanks to its selectivity led by the detector mass spectrometer and the separate dimension of chromatography liquid. In addition, recourse to UHPLC (ultra high performance liquid chromatography) allows improving selectivity and sensitivity while limiting the samples volumes. The "ready-to-use" kits are now available and added to the "homemade" techniques developed by laboratories, thus giving opportunity for measurement of a wide steroid panel with only one sample. Finally, mass spectrometry methods, including a prior extraction step, allow the use of varied biological fluids (blood, urine, saliva…). Also, several clinical indications could gain from mass spectrometry, especially when hormone levels are low, when several steroids have to be identified, when the sample volume is low. However, this technology represents an important financial investment and in-depth staff training. In addition, some steroids are not easily quantifiable by mass spectrometry. It is likely by immunoassay and mass spectrometry, well-matched technologies, that we could answer the best to clinical questions about steroids. PMID:25582724

Dufour-Rainfray, Diane; Moal, Valérie; Cloix, Lucie; Mathieu, Elisabeth; Gauchez, Anne-Sophie; Brossaud, Julie; Corcuff, Jean-Benoît; Fraissinet, François; Collet, Christine; Boux de Casson, Florence; Guilloteau, Denis; Emond, Patrick; Reynier, Pascal

2015-01-01

173

Synthesis of pentacyclic steroids.  

Science.gov (United States)

Due to their high profile biological activity, the steroids are among the most important secondary metabolites. A review of literature on the synthesis of pentacyclic steroids is presented. PMID:18495190

Ibrahim-Ouali, Malika

2008-09-01

174

Inhaled Steroid Drugs  

Science.gov (United States)

... One is a class of drugs called inhaled steroids. There are six medicines in this class. To ... choose among them, Consumer Reports has analyzed the steroid inhalers based on their effectiveness, safety, dosing convenience, ...

175

Conceptualization and measurement of homosexuality in sex surveys: a critical review  

Directory of Open Access Journals (Sweden)

Full Text Available This article reviews major national population sex surveys that have asked questions about homosexuality focusing on conceptual and methodological issues, including the definitions of sex, the measured aspects of homosexuality, sampling and interviewing technique, and questionnaire design. Reported rates of major measures of same-sex attraction, behavior, partners, and sexual identity from surveys are also presented and compared. The study of homosexuality in surveys has been shaped by the research traditions and questions ranging from sexology to the epidemiology of HIV/AIDS. Sexual behavior has been a central topic at least since Kinsey. Issues of sexual attraction and/or orientation and sexual identity have emerged more recently. Differences in the treatment of men and women in the design and analysis of surveys as well as in the reported rates in different surveys, in different countries and time periods are also presented and discussed. We point out the importance of the consideration of both methodological and social change issues in assessing such differences.

Michaels Stuart

2006-01-01

176

Minireview: tipping the balance: ligand-independent activation of steroid receptors.  

Science.gov (United States)

Steroid receptors are prototypical ligand-dependent transcription factors and a textbook example for allosteric regulation. According to this canonical model, binding of cognate steroid is an absolute requirement for transcriptional activation. Remarkably, the simple one ligand-one receptor model could not be farther from the truth. Steroid receptors, notably the sex steroid receptors, can receive multiple inputs. Activation of steroid receptors by other signals, working through their own signaling pathways, in the absence of the cognate steroids, represents the most extreme form of signaling cross talk. Compared with cognate steroids, ligand-independent activation pathways produce similar but not identical outputs. Here we review the phenomena and discuss what is known about the underlying molecular mechanisms and the biological significance. We hypothesize that steroid receptors may have evolved to be trigger happy. In addition to their cognate steroids, many posttranslational modifications and interactors, modulated by other signals, may be able to tip the balance. PMID:25625619

Bennesch, Marcela A; Picard, Didier

2015-03-01

177

Recent advances in steroid radioimmunoassay  

International Nuclear Information System (INIS)

The advances since 1974 in the techniques of measuring steroid molecules by radioimmunoassay are reviewed in this paper. They are considered under the following headings: preparation and use of antisera; preparation and use of tracers; preparation of biological samples before assay; dispensing of the reagents in the assay; separation of free and bound radioactivity; counting and data processing; quality control and standardization. (orig.)

178

Age- and sex-related changes in bone mass measured by neutron activation  

Energy Technology Data Exchange (ETDEWEB)

Total-body calcium (TBCa) measurements have been employed in two basic types of studies. In the first type, serial measurements made on an individual patient are used to trace the time variation in body calcium. In the second type of study, the absolute total body calcium of an individual is determined and compared to a standard or predicted value in order to determine the deficit or excess of calcium. Generally, the standards are derived from data obtained from normal populations and grouped by the parameters of age and sex (mean value denoted TBCa/sub m/). In the study reported in this paper, the clinical usefulness of predicted calcium (TBCa/sub p/) is evaluated. The predicted value (TBCa/sub p/) for an individual is obtained with an algorithm utilizing values of sex and age, height and lean body mass (as derived from /sup 40/K measurement). The latter two components characterize skeletal size and body habitus, respectively. For the study, 133 white women and 71 white men ranging in age from 20 to 80 years were selected from a larger population. Individuals with evidence of metabolic calcium disorders or osteoporosis were excluded. Additionally, the women and men selected were first judged to have total body potassium levels in the normal range. For each age decade, the variance of TBCa values of these individuals, when expressed in terms of TBCa/sub p/, was significantly less than when expressed in terms of TBCa/sub m/. Thus, erroneous conclusions based on Ca deficit in osteoporosis could be drawn for individuals whose height and body size differ markedly from the average, as the variation of their TBCa values often exceeds the variation in the age and sex cohort. Data on a group of osteoporotic women were compared with the normal skeletal baseline values both in terms of the TBCa and the TBCa/sub p/ values.

Cohn, S.H.; Aloia, J.F.; Vaswani, A.N.; Zanzi, I.; Vartsky, D.; Ellis, K.J.

1981-01-01

179

Age- and sex-related changes in bone mass measured by neutron activation  

International Nuclear Information System (INIS)

Total-body calcium (TBCa) measurements have been employed in two basic types of studies. In the first type, serial measurements made on an individual patient are used to trace the time variation in body calcium. In the second type of study, the absolute total body calcium of an individual is determined and compared to a standard or predicted value in order to determine the deficit or excess of calcium. Generally, the standards are derived from data obtained from normal populations and grouped by the parameters of age and sex (mean value denoted TBCa/sub m/). In the study reported in this paper, the clinical usefulness of predicted calcium (TBCa/sub p/) is evaluated. The predicted value (TBCa/sub p/) for an individual is obtained with an algorithm utilizing values of sex and age, height and lean body mass (as derived from 40K measurement). The latter two components characterize skeletal size and body habitus, respectively. For the study, 133 white women and 71 white men ranging in age from 20 to 80 years were selected from a larger population. Individuals with evidence of metabolic calcium disorders or osteoporosis were excluded. Additionally, the women and men selected were first judged to have total body potassium levels in the normal range. For each age decade, the variance of TBCa values of these individuals, when expressed in terms of TBCa/sub p/, was significantly less than when expressed in terms of TBCa/sub m/. Thus, erroneous conclusions based on Ca deficit in osteoporosis could be drawn for individuals whose height and body size differ markedly from the average, as the variation of their TBCa values often exceeds the variation in the age and sex cohort. Data on a group of osteoporotic women were compared with the normal skeletal baseline values both in terms of the TBCa and the TBCa/sub p/ values

180

Steroids in childhood epilepsy  

Directory of Open Access Journals (Sweden)

Full Text Available Treatment of epileptic encephalopathies can be very challenging as most anticonvulsant drugs fail to achieve good seizure control. Steroids are disease modifying as well as anticonvulsant in these conditions. Though steroids are accepted as the first-line treatment for infantile spasms, there are many unanswered questions with regard to the preparation, dose and duration of treatment. In this review a re-exploration of the literature is attempted. Putative mechanism of action of steroids in infantile spasms is also discussed. As steroids are being increasingly used in other epileptic encephalopathies and Rasmussen?s encephalitis, a brief discussion on the role of steroids in these conditions is attempted. The review ends with the discussion on newer neuroactive steroids in the management of epilepsy.

Ramachandrannair Rajesh

2006-01-01

181

The alteration of the urinary steroid profile under the stress  

Directory of Open Access Journals (Sweden)

Full Text Available In the second part of twentieth century anabolic-androgenic steroids were introduced into doping practice and received continuously increasing significance. In order to prove the usage of doping substances, the determination of steroid profile in the urine came into practice. Several factors may be responsible for alterations in the normal steroid profile for example age, sex and diet. The aim of this study was to find out, whether the psychological stress may cause modifications in the steroid profile and T/Et ratio. The effect of physical activity was also considered. The steroid profile was determined in the group of 34 students being in non-stress conditions and under stress immediately before an important university exam. The intensity of stress was rated by self-reported questionnaire. The GC/MS method was applied to determine the steroid profile in the urine samples. The results of the experiment have shown that psychological stress may cause significant changes in the steroid profile, especially in females. Physical activity, independently of stress significantly modified the steroid profile. In summary, observed changes in steroid profile suggest, that major fluctuations of T/Et and A/E ratios under the influence of stressogenic factors and physical activity are unlikely.

A Gronowska

2010-03-01

182

Steroid ulcers: Any news?  

OpenAIRE

Steroid ulcers, although a common feature in experimental studies, seldom develop in clinical practice, as observed by the meta-analyses carried out in the 90s. Corticosteroids alone become ulcerogenic only if treatment lasts longer than one month and the total administered dose exceeds 1000 mg. On the other hand concomitant intake of non-steroidal anti-inflammatory drugs results in a synergistic, highly damaging effect on the gastroduodenal mucosa. Thus, despite the survival of the steroid u...

Guslandi, Mario

2013-01-01

183

Steroids in childhood epilepsy  

OpenAIRE

Treatment of epileptic encephalopathies can be very challenging as most anticonvulsant drugs fail to achieve good seizure control. Steroids are disease modifying as well as anticonvulsant in these conditions. Though steroids are accepted as the first-line treatment for infantile spasms, there are many unanswered questions with regard to the preparation, dose and duration of treatment. In this review a re-exploration of the literature is attempted. Putative mechanism of action of steroids in i...

Ramachandrannair Rajesh

2006-01-01

184

Quantification of steroids and endocrine disrupting chemicals in rat ovaries by LC-MS/MS for reproductive toxicology assessment.  

Science.gov (United States)

Reproductive function is controlled by a finely tuned balance of androgens and estrogens. Environmental toxicants, notably endocrine disrupting chemicals (EDCs), appear to be involved in the disruption of hormonal balance in several studies. To further describe the effects of selected EDCs on steroid secretion in female rats, we aim to simultaneously investigate the EDC concentration and the sex hormone balance in the ovaries. Therefore, an effective method has been developed for the quantification of the sex steroid hormones (testosterone, androstenedione, estradiol, and estrone) and four endocrine disrupting chemicals (bisphenol A, atrazine, and the active metabolites of methoxychlor and vinclozolin) in rat ovaries. The sample preparation procedure is based on the so-called "quick, easy, cheap, effective, rugged, and safe" approach, and an analytical method was developed to quantify these compounds with low detection limits by liquid chromatography coupled with a tandem mass spectrometer. This analytical method, applied to rat ovary samples following subacute EDC exposure, revealed some new findings for toxicological evaluation. In particular, we showed that EDCs with the same described in vitro mechanisms of action have different effects on the gonadal steroid balance. These results highlight the need to develop an integrative evaluation with the simultaneous measurement of EDCs and numerous steroids for good risk assessment. PMID:22526662

Quignot, Nadia; Tournier, Mikaël; Pouech, Charlène; Cren-Olivé, Cécile; Barouki, Robert; Lemazurier, Emmanuel

2012-06-01

185

Development and Refinement of a Measure of Attitudes toward Sex Offender Treatment  

Science.gov (United States)

In recent years public attitudes toward sex offenders have become increasingly punitive. Consequently, new legislation pertaining to the sentencing and treatment of convicted sex offenders has been focused on containment and monitoring rather than rehabilitation. However, research suggests that treatment programs for sex offenders are effective in…

Wnuk, Dorota; Chapman, Jason E; Jeglic, Elizabeth L.

2006-01-01

186

Localization and functions of steroid hormone receptors  

OpenAIRE

This review focuses on the subcellular localization of steroid hormone receptors (SHRs), taking into account the technical problems of immunohistochemistry and the characteristics of nuclear localization signals (NLSs) of each receptor, on the interaction between SHKs and cellular components, and on the possible roles of sex SHRs in the reproductive organs. It is concluded that SHRs are basically localized in the nucleus, regardless of hormonal status, and that...

Yamashita, S.

1998-01-01

187

Principles and clinical applications of liquid chromatography - tandem mass spectrometry for the determination of adrenal and gonadal steroid hormones.  

Science.gov (United States)

Liquid-chromatography - tandem mass spectrometry (LC-MS/MS) is becoming the method of choice for clinical steroid analysis. In most instances, it has the advantage of higher sensitivity, better reproducibility and greater specificity than commercial immunoassay techniques. The method requires only minimal sample preparation and a small sample volume. Furthermore, it has the potential to analyze multiple steroids simultaneously. Modern instruments guarantee high throughput, allowing an affordable price for the individual assay. All this makes LC-MS/MS an attractive method for use in a clinical setting. Reliable reference ranges for the detected analytes are the pre-requisite for their clinical use. If these are available, LC-MS/MS can find application in congenital disorders of steroid metabolism, such as congenital adrenal hyperplasia, disorders of sex development and disorders of salt homeostasis, as well as in acquired disorders of steroid metabolism, such as primary aldosteronism, Cushing's disease, Addison's disease, and hyperandrogenemia, as well as in psychiatric disease states such as depression or anxiety disorders. The principles of LC-MS/MS for steroid measurement, the pros and cons of LC-MS/MS compared with conventional immunoassays and the possible applications in clinical routine, with a special focus on pediatric endocrinology needs, are discussed here. PMID:21738000

Kulle, A E; Welzel, M; Holterhus, P-M; Riepe, F G

2011-10-01

188

Steroid Hormones Stimulate Germination and Tube Growth of in Vitro Matured Tobacco Pollen.  

Science.gov (United States)

A study of the effects of different steroids on germination and tube growth of tobacco pollen (Nicotiana tabacum L. cv Petit Havana SR1) matured in vitro is presented. Application of the mammalian steroid sex hormones (testosterone, progesterone, and estradiol) resulted in a stimulation of pollen germination and tube elongation. The presence of both steroids and flavonols in the germination medium strongly enhanced the growth of tobacco male gametophytes. PMID:12228388

Ylstra, B.; Touraev, A.; Brinkmann, A. O.; Heberle-Bors, E.; Tunen, AJV.

1995-02-01

189

Conserved steroid hormone homology converges on nuclear factor ?B to modulate inflammation in asthma.  

Science.gov (United States)

Asthma is a complex, multifactorial disease comprising multiple different subtypes, rather than a single disease entity, yet it has a consistent clinical phenotype: recurring episodes of chest tightness, wheezing, and difficulty breathing (Pediatr Pulmonol Suppl. 1997;15:9-12). Despite the complex pathogenesis of asthma, steroid hormones (eg, glucocorticoids) are ubiquitous in the short-term and long-term management of all types of asthma. Overall, steroid hormones are a class of widely relevant, biologically active compounds originating from cholesterol and altered in a stepwise fashion, but maintain a basic 17-carbon, 4-ring structure. Steroids are lipophilic molecules that diffuse readily through cell membranes to directly and/or indirectly affect gene transcription. In addition, they use rapid, nongenomic actions to affect cellular products. Steroid hormones comprise several groups (including glucocorticoids, sex steroid hormones, and secosteroids) with critical divergent biological and physiological functions relevant to health and disease. However, the conserved homology of steroid hormone molecules, receptors, and signaling pathways suggests that each of these is part of a dynamic system of hormone interaction, likely involving an overlap of downstream signaling mechanisms. Therefore, we will review the similarities and differences of these 3 groups of steroid hormones (ie, glucocorticoids, sex steroid hormones, and secosteroids), identifying nuclear factor ?B as a common inflammatory mediator. Despite our understanding of the impact of individual steroids (eg, glucocorticoids, sex steroids and secosteroids) on asthma, research has yet to explain the interplay of the dynamic system in which these hormones function. To do so, there needs to be a better understanding of the interplay of classic, nonclassic, and nongenomic steroid hormone functions. However, clues from the conserved homology steroid hormone structure and function and signaling pathways offer insight into a possible model of steroid hormone regulation of inflammation in asthma through common nuclear factor ?B-mediated downstream events. PMID:22183120

Payne, Asha S; Freishtat, Robert J

2012-01-01

190

Problems of Birds Sex Determination  

Directory of Open Access Journals (Sweden)

Full Text Available Sex determination system in birds is characterized by a homo-(Neognatae and heteromorphic (Paleognatae sex chromosomes. Heterogametic sex is female (ZZ/ZW system. DMRT1 gene is a gene regarded as a main male sex determining factor in this group of animals. The question remains about the participation of other factors (HEMOGEN, AMH etc. in appearance of testis, and the role of steroid hormones in formation of ovaries. Complete sex inversion is not typical for species with genotypic sex determination (GSD, although the effect of estrogen metabolites is noted for birds. For birds epigenetic mechanisms of regulation (methylation of DNA and non-coding RNA have been described for sex controlling genes such as CYP19A1 and DMRT1.

Antonina V. Trukhina

2014-09-01

191

Conceptualization and measurement of homosexuality in sex surveys: a critical review Modos de conceitualizar e medir homossexualidade em pesquisas sobre sexualidade: uma revisão crítica  

OpenAIRE

This article reviews major national population sex surveys that have asked questions about homosexuality focusing on conceptual and methodological issues, including the definitions of sex, the measured aspects of homosexuality, sampling and interviewing technique, and questionnaire design. Reported rates of major measures of same-sex attraction, behavior, partners, and sexual identity from surveys are also presented and compared. The study of homosexuality in surveys has been shaped by the re...

Stuart Michaels; Brigitte Lhomond

2006-01-01

192

Measuring Effectiveness in School Sex Education--Methodological Dilemmas in Researching an Intervention Involving Young Mothers  

Science.gov (United States)

Defining and therefore evaluating the effectiveness of school sex education is problematic because of its location at the site of struggle between competing discourses. Those discourses--summarised here as "moralistic," "harm reductionist" and "empowering"--each emphasise a different conceptualisation of sex education's intended outcomes. The…

Kidger, Judi

2006-01-01

193

Virtual characters designed for forensic assessment and rehabilitation of sex offenders: standardized and made-to-measure  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents two studies pertaining to the use of virtual characters applied in clinical forensic rehabilitation of sex offenders. The first study is about the validation of the perceived age of virtual characters designed to simulate primary and secondary sexual character of typical adult and child individuals. The second study puts to use these virtual characters in comparing a group of sex offenders and a group of non deviant individuals on their sexual arousal responses as recorded in virtual immersion. Finally, two clinical vignettes illustrating the use of made-to-measure virtual characters to more closely fit sexual preferences are presented in Discussion.

Benoît Dassylva

2010-11-01

194

Motor function measure scale, steroid therapy and patients with Duchenne muscular dystrophy / Medida de função motora, corticoterapia e pacientes com distrofia muscular de Duchenne  

Scientific Electronic Library Online (English)

Full Text Available OBJETIVO: Avaliar a evolução da função motora de pacientes com distrofia muscular de Duchenne (DMD) em corticoterapia (predinisolona e deflazacort), por meio da escala Medida da Função Motora (MFM), que avalia três dimensões de funções motoras (D1, D2, D3). MÉTODOS: Trinta e três pacientes com DMD ( [...] 22 deambulantes, seis cadeirantes e cinco que perderam a capacidade de andar ao longo do estudo) foram avaliados pela escala MFM em seis momentos durante 18 meses. RESULTADOS: Todas as funções motoras mantiveram-se estáveis durante 14 meses, exceto D1 para os pacientes que perderam a marcha. Nos pacientes deambulantes, a D2 (função motora axial e proximal) apresentou melhora durante seis meses. Melhora em D3 (função motora distal) também foi observada durante o seguimento. A D1 (postura em pé e transferências) e o escore total foram importantes para predizer a perda de marcha. CONCLUSÕES: O uso da MFM nos pacientes com DMD confirma os benefícios do tratamento com corticoides na diminuição da velocidade de progressão da doença. Abstract in english OBJECTIVE: To assess the evolution of motor function in patients with Duchenne muscular dystrophy (DMD) treated with steroids (prednisolone or deflazacort) through the Motor Function Measure (MFM), which evaluates three dimensions of motor performance (D1, D2, D3). METHODS: Thirty-three patients wit [...] h DMD (22 ambulant, 6 non-ambulant and 5 who lost the capacity to walk during the period of the study) were assessed using the MFM scale six times over a period of 18 months. RESULTS: All the motor functions remained stable for 14 months in all patients, except D1 for those who lost their walking ability. In ambulant patients, D2 (axial and proximal motor capacities) motor functions improved during six months; an improvement in D3 (distal motor capacity) was noted during the total follow-up. D1 (standing posture and transfers) and total score were useful to predict the loss of the ability to walk. CONCLUSIONS: The use of the MFM in DMD patients confirms the benefits of the steroid treatment for slowing the progression of the disease.

Elaine C. da, Silva; Darlene L., Machado; Maria B. D., Resende; Renata F., Silva; Edmar, Zanoteli; Umbertina C., Reed.

2012-03-01

195

Standardization of androstenedione and estrone radioimmunoassay and profile of sex steroids, gonadotropins and prolactin - in patients with chronic anovulation due to inappropriate feedback (polycystic ovarian syndrome); Padronizacao do radioimunoensaio da androstenediona e da estrona e o perfil dos esteroides sexuais, gonadotrofinas e prolactina em pacientes com anovulacao cronica por retrocontrole improprio (sindrome dos ovarios policisticos)  

Energy Technology Data Exchange (ETDEWEB)

Full text. In order to evaluate the profile of the sex steroids gonadotropin and prolactin in polycystic ovarian syndrome (POS), 24 patients with POS were studied and compared with 20 normal women during the early follicular phase of the menstrual cycle. Radioimmunoassay techniques for androstenedione (A) and estrone (E{sub 1}) were standardized for the purpose of the study. Androstenedione and estrone were extracted from plasma with ethyl ether. The assays were maintained in equilibrium and the labelled hormone-antibody complex was then separated from the free hormone using dextran charcoal. The sensitivity of the method was 6.8 pg/tube for A and 3.7 pg/tube for E{sub 1}. Nonspecific binding ws 3.4 for A and 3.3 for E{sub 1}. The interessay error at the D50 level was 15.6 for A and 8.6 for E{sub 1}. Patients with POS had significantly higher basal levels of LH, A, T E{sub 1} and PRL and similar FSH and DHEA-S levels when compared with normal women. The LH/FSH ratio was significantly elevated and the A/T ratio was significantly decreased. The A/E{sub 1} and T/E{sub 2} ratios were elevated and the E{sub 1}/E{sub 2} was decreased, although the differences were not statistically significant. A positive correlation between A and E{sub 1} was observed in patients with POS. In view of the above data, it was concluded that: the quality control parameters of the radioimmunoassay for A and E{sub 1} standardized in the present study are considered satisfactory, and the assay could be used for diagnosis and research; the patients with POS have a different sex steroid and gonadotropin profile when compared normal women during the early follicular phase of the menstrual cycle

Vilanova, Maria do Socorro Veras

1992-12-01

196

Quantitative measure of sexual selection with respect to the operational sex ratio: a comparison of selection indices  

OpenAIRE

Despite numerous indices proposed to predict the evolution of mating systems, a unified measure of sexual selection has remained elusive. Three previous studies have compared indices of sexual selection under laboratory conditions. Here, we use a genetic study to compare the most widely used measures of sexual selection in natural populations. We explored the mating and reproductive successes of male and female bank voles, Clethrionomys glareolus, across manipulated operational sex ratios (OS...

Mills, Suzanne C.; Grapputo, Alessandro; Koskela, Esa; Mappes, Tapio

2006-01-01

197

Measuring the effects of aging and sex on regional brain stiffness with MR elastography in healthy older adults.  

Science.gov (United States)

Changes in tissue composition and cellular architecture have been associated with neurological disease, and these in turn can affect biomechanical properties. Natural biological factors such as aging and an individual's sex also affect underlying tissue biomechanics in different brain regions. Understanding the normal changes is necessary before determining the efficacy of stiffness imaging for neurological disease diagnosis and therapy monitoring. The objective of this study was to evaluate global and regional changes in brain stiffness as a function of age and sex, using improved MRE acquisition and processing that have been shown to provide median stiffness values that are typically reproducible to within 1% in global measurements and within 2% for regional measurements. Furthermore, this is the first study to report the effects of age and sex over the entire cerebrum volume and over the full frontal, occipital, parietal, temporal, deep gray matter/white matter (insula, deep gray nuclei and white matter tracts), and cerebellum volumes. In 45 volunteers, we observed a significant linear correlation between age and brain stiffness in the cerebrum (P.20 for all other regions). The model predicted female occipital and temporal lobes to be 0.23kPa and 0.09kPa stiffer than males of the same age, respectively. This study confirms that as the brain ages, there is softening; however, the changes are dependent on region. In addition, stiffness effects due to sex exist in the occipital and temporal lobes. PMID:25698157

Arani, Arvin; Murphy, Matthew C; Glaser, Kevin J; Manduca, Armando; Lake, David S; Kruse, Scott A; Jack, Clifford R; Ehman, Richard L; Huston, John

2015-05-01

198

Self-reported Sex Partner Dates for Use in Measuring Concurrent Sexual Partnerships: Correspondence Between Two Assessment Methods.  

Science.gov (United States)

Although prevalence of concurrent sexual partnerships is increasingly investigated as a driver of HIV epidemics, its measurement varies and its role in transmission dynamics remains contested. Relying on different methods of obtaining self-reported partnership histories may lead to significant differences in prevalence. This study examined the reliability of two methods for assessing dates of sex and the implications for measuring concurrent sexual partnerships. We conducted a cross-sectional reliability study using self-reported survey data from 650 women ages 18-65 years, recruited online nationwide for human papillomavirus natural history studies from 2007 to 2012. Intermethod reliability of first and last sex with the most recent partner was assessed using weighted kappa. Intraclass correlation coefficient was estimated for intramethod reliability across two consecutive questionnaires administered 4 months apart. Point prevalence of concurrent sexual partnerships at 6 months prior to the questionnaire date was similar between the two question formats (10.5 % for categorical and 10.9 % for continuous). The range between the minimum and maximum cumulative prevalence for 12 months was larger when using the categorical questions (17.0-29.6 % compared to 27.6-28.6 % using the continuous questions). Agreement between the two question formats was moderate for the date of first sex with the most recent partner (? = 0.56, 95 % CI 0.48-0.64) and almost perfect for the date of last sex (? = 0.93, 95 % CI 0.91-0.94). Longitudinal agreement for date of first sex was high for the continuous date question (ICC = 0.89, 95 % CI 0.86-0.92). Results of this reliability study can be used to inform the design of future studies of concurrent sexual partnerships and their association with HIV. PMID:25391584

Huang, Claire E; Cassels, Susan L; Winer, Rachel L

2015-05-01

199

Mind Over Matter: Anabolic Steroids  

Science.gov (United States)

... Easy-to-Read Web site Citation Site Map Mind Over Matter Teaching Guide and Series Anabolic Steroids Home / Educators / NIDA Teaching Guides / Mind Over Matter Teaching Guide and Series / Anabolic Steroids Print Anabolic ...

200

Does the mechanism of sex determination constrain the potential for sex manipulation? A test in geckos with contrasting sex-determining systems  

Science.gov (United States)

The concentration of yolk steroids was suggested to influence offspring gender in oviparous animals subject to both temperature-dependent sex determination (TSD) and genotypic sex determination (GSD). However, the proposed mechanisms of steroid effects are thought to differ between TSD and GSD: a direct effect of oestrogens on gonad feminisation in TSD species vs a differential induction of male-producing or female-producing gametes in GSD species. Geckos offer an ideal opportunity for testing these suggested mechanisms. Closely related gecko species differ in their modes of sex determination. They lay clutches of two synchronously formed eggs; both eggs share equal steroid levels. If identical hormonal composition and environment during vitellogenesis, gravidity and incubation determine the sex of the progeny, siblings should share the same gender in both TSD and GSD geckos. We found strong support for this prediction in a TSD gecko species. Among clutches that were incubated at the temperature that produced both sexes, there were no clutches with siblings of the opposite sex. On the other hand, about half of the clutches yielded siblings of the opposite sex in four GSD species. These results suggest that sex-determining systems constrain the ability of the female to produce single-sex siblings and, hence, it seems that the GSD mechanism constrains the opportunities for sex ratio manipulation in geckos via yolk steroid manipulation.

Kratochvíl, Lukáš; Kubi?ka, Lukáš; Landová, Eva

2008-03-01

201

Social interactions unmask sex differences in humoral immunity in voles.  

Science.gov (United States)

Sex differences in immune function are well established among laboratory rodents, with males typically having lower immunity than females. This sex difference may reflect the suppressive effects of testosterone on immune function. Because polygynous males generally have higher circulating testosterone concentrations than monogamous males, sex differences in immune function are hypothesized to be more pronounced among polygynous as compared to monogamous species. Sex differences in immune function have not been consistently observed among individually housed Microtus in the laboratory; thus, social interactions are hypothesized to be necessary for the expression of sex differences in immune function. We assessed the effect of differential housing conditions on humoral immunity and steroid hormone concentrations in polygynous meadow voles Microtus pennsylvanicus, and monogamous prairie voles M. ochrogaster. We examined humoral immunity by immunizing voles with keyhole limpet haemocyanin (KLH) and measuring antibody production 5, 10, 15 and 30 days postimmunization. Overall, meadow voles mounted higher anti-KLH immunoglobulin (Ig)M and IgG responses than prairie voles, regardless of the housing condition. Sex differences in antibody production were only observed among meadow voles housed in pairs, in which females had higher anti-KLH IgM and IgG responses than males. Sex differences in antibody production were not observed among prairie voles or meadow voles housed individually. Sex and species differences in circulating oestradiol, testosterone, and corticosterone concentrations were not related to differences in humoral immunity. These data suggest that sex differences in immune function are more pronounced among polygynous species than monogamous species, but may be context dependent. Copyright 1999 The Association for the Study of Animal Behaviour. PMID:10196049

Klein; Nelson

1999-03-01

202

Steroids. A Resource Guide.  

Science.gov (United States)

This guide provides information on steroid use as well as prevention and intervention strategies. It is intended to serve as a supplement to drug abuse education and prevention programs in elementary and secondary schools and as the basis for local curriculum development and instructional activities. The following topics are covered: (1) history…

New York State Education Dept., Albany. Bureau of School Health Education and Services.

203

Sex dimorphism of cortical water diffusion in normal aging measured by magnetic resonance imaging  

Directory of Open Access Journals (Sweden)

Diffusion-weighted images covering the majority of the brain were acquired from 77 healthy participants. Both the mean water diffusivity and diffusion kurtosis were calculated from the cortical regions and parcellated according to the template in Anatomical Automatic Labeling. The mean water diffusivity and diffusion kurtosis from both sexes were examined and subsequently correlated with age. Statistical significance was set at a threshold of p

Jiun-JieWang

2013-11-01

204

Examining the effects of age, sex, and body mass index on normative median motor nerve excitability measurements.  

LENUS (Irish Health Repository)

OBJECTIVES: The purpose of this study was to build a large reference database of excitability measures in normal subjects and to examine the effects of age, sex, and BMI. METHODS: One hundred and five healthy subjects had median motor nerve excitability testing performed at the wrist using the automated threshold-tracking program, QTRAC. Statistical linear regression was used to explore relationships between nerve excitability and the independent variables. RESULTS: The main effect of age is a reduced superexcitability. Lesser effects are flattening of the normalized stimulus response curve and reduction in threshold change following strong hyperpolarizing currents. Females have lower thresholds than males and small but significant differences in voltage-gated potassium channel (KCNQ) mediated properties (late subexcitability, accommodation half time, and threshold undershoot following depolarizing electrotonus), as well as a small increase in superexcitability. BMI has no influence on nerve excitability data and does not explain sex-related differences in threshold. CONCLUSIONS: Age and sex have few and small effects on excitability parameters. SIGNIFICANCE: The expression of nodal KCNQ channels appears to be greater in females. Age-related increases in subexcitability may be attributable to changes in the muscle fibre and not the nerve.

McHugh, John C

2012-02-01

205

Regulation of brain microglia by female gonadal steroids.  

Science.gov (United States)

Microglial cells are the primary mediators of the CNS immune defense system and crucial for shaping inflammatory responses. They represent a highly dynamic cell population which is constantly moving and surveying their environment. Acute brain damage causes a local attraction and activation of this immune cell type which involves neuron-to-glia and glia-to-glia interactions. The prevailing view attributes microglia a "negative" role such as defense and debris elimination. More topical studies also suggest a protective and "positive" regulatory function. Estrogens and progestins exert anti-inflammatory and neuroprotective effects in the CNS in acute and chronic brain diseases. Recent work revealed that microglial cells express subsets of classical and non-classical estrogen and progesterone receptors in a highly dynamic way. In this review article, we would like to stress the importance of microglia for the spreading of neural damage during hypoxia, their susceptibility to functional modulation by sex steroids, the potency of sex hormones to switch microglia from a pro-inflammatory M1 to neuroprotective M2 phenotype, and the regulation of pro- and anti-inflammatory properties including the inflammasome. We will further discuss the possibility that the neuroprotective action of sex steroids in the brain involves an early and direct modulation of local microglia cell function. This article is part of a Special Issue entitled 'Sex steroids and brain disorders'. PMID:24607811

Habib, Pardes; Beyer, Cordian

2015-02-01

206

Viviparity as a constraint on sex-ratio evolution.  

OpenAIRE

In polytocous mammals, the sex ratio during gestation can influence a variety of morphological, physiological, and life-history traits because of steroid leakage between fetuses. Similar phenomena have also recently been described for a viviparous lizard. Some of these effects have important fitness consequences by influencing reproductive success later in life. Thus, biasing the sex ratio toward one sex may lead to a decreased fitness for the other sex, and therefore constrain the evolution ...

Uller, T.

2003-01-01

207

Radioimmunoassay of synthetic steroids  

International Nuclear Information System (INIS)

The sensitivity of a radioimmunoassay depends on the intrinsic association constant of the interaction between ligand and antibody. Its specificity depends on the position of the chain which forms the link with the antigen. Thus, an antibody specific of estradiol has been obtained by coupling estradiol to albumin via a chain at position 7. For synthetic steroids the structure of which is sufficiency different from that of natural hormones, the requirements for a sensitive assay method not involving chromatography are simply maximum affinity and positioning of the couple at a site which does not undergo metabolic attack. These criteria were used to develop assays for R 2858 and R 2453 which obviate the need to administer radioactive product in clinical pharmacology. Cross-reaction with structural analogs may be used to assay competitors. Thus, R 2323 antibody, highly specific for endogenous steroids, may be used to assay other trienes such as R 1697 (trenbolone) and R 2010 (norgestrienone)

208

Steroids facing emotions  

OpenAIRE

The studies reported in this thesis have been performed to gain a better understanding about motivational mediators of selective attention and memory for emotionally relevant stimuli, and about the roles that some steroid hormones play in regulation of human motivation and emotion. The stimuli used are pictures of human facial expressions of emotion. The main interest was in establishing psychoneuronedocrine and psychological motivational predictors of biased processing of angry and fearful f...

Putman, Peter Leo Johan

2006-01-01

209

Steroid resistance in leukemia  

OpenAIRE

There are several types of leukemia which are characterized by the abnormal growth of cells from the myeloid or lymphoid lineage. Because of their lympholytic actions, glucocorticoids (GCs) are included in many therapeutic regimens for the treatment of various forms of leukemia. Although a significant number of acute lymphoblastic leukemia patients respond well to GC treatment during initial phases; prolonged treatments sometimes results in steroid-resistance. The exact mechanism of this resi...

Shah, Darshan S.; Kumar, Raj

2013-01-01

210

Safe sex  

Science.gov (United States)

Safe sex means taking steps before and during sex that can prevent you from getting an infection, or from ... the skin around the genital area. Before having sex: Get to know your partner and discuss your ...

211

Sleep, Rhythms, and the Endocrine Brain: Influence of Sex and Gonadal Hormones  

OpenAIRE

While much is known about the mechanisms that underlie sleep and circadian rhythms, the investigation into sex differences and gonadal steroid modulation of sleep and biological rhythms is in its infancy. There is a growing recognition of sex disparities in sleep and rhythm disorders. Understanding how neuroendocrine mediators and sex differences influence sleep and biological rhythms is central to advancing our understanding of sleep-related disorders. While it is known that ovarian steroids...

Mong, Jessica A.; Baker, Fiona C.; Mahoney, Megan M.; Paul, Ketema N.; Schwartz, Michael D.; Semba, Kazue; Silver, Rae

2011-01-01

212

Nonprescription Steroids on the Internet  

OpenAIRE

This study evaluated the degree to which anabolic-androgenic steroids are proffered for sale over the Internet and how they are characterized on popular websites. Searches for specific steroid product labels (e.g., Dianabol) between March and June, 2006 revealed that approximately half of the websites advocated their “safe” use, and roughly one-third offered to sell them without prescriptions. The websites frequently presented misinformation about steroids and minimized their dangers. Les...

Mcdonald, Christen L.; Marlowe, Douglas B.; Patapis, Nicholas S.; Festinger, David S.; Forman, Robert F.

2011-01-01

213

Steroid induced huge mediastinal lipomatosis  

International Nuclear Information System (INIS)

Mediastinal lipomatosis induced by steroid is an unusual byproduct of such therapy and has been reported after prolonged and large doses of steroid therapy. The radiologic findings of mediastinal lipomatosis in simple chest film are nonspecific, but with the advent of CT scan, differentiation the fatty lesion from other mediastinal decreases can be made easily. Recently we expended steroid induced huge mediastinal lipomatosis and report the case with review including radiologic findings

214

Steroid induced huge mediastinal lipomatosis  

Energy Technology Data Exchange (ETDEWEB)

Mediastinal lipomatosis induced by steroid is an unusual byproduct of such therapy and has been reported after prolonged and large doses of steroid therapy. The radiologic findings of mediastinal lipomatosis in simple chest film are nonspecific, but with the advent of CT scan, differentiation the fatty lesion from other mediastinal decreases can be made easily. Recently we expended steroid induced huge mediastinal lipomatosis and report the case with review including radiologic findings.

Kim, Jang Min; Chung, Suk Tae; Kang, Eun Young; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)

1990-04-15

215

Topical Steroid-Damaged Skin  

OpenAIRE

Topical steroids, commonly used for a wide range of skin disorders, are associated with side effects both systemic and cutaneous. This article aims at bringing awareness among practitioners, about the cutaneous side effects of easily available, over the counter, topical steroids. This makes it important for us as dermatologists to weigh the usefulness of topical steroids versus their side effects, and to make an informed decision regarding their use in each individual based on other factors s...

Abraham, Anil; Roga, Gillian

2014-01-01

216

Measurements of vertebral shape by r[iographic morphometry: sex differences and relationships with vertebral level and lumbar lordosis  

International Nuclear Information System (INIS)

Objective. To examine sex-related and vertebral-level-specific differences in vertebral shape and to investigate the relationships between the lumbar lordosis angle and vertebral morphology. Design and patients. Lateral thoracic and lumbar spine r[iographs were obtained with a standardized protocol in 142 healthy men and 198 healthy women over 50 years old. Anterior (Ha), central (Hc) and posterior (Hp) heights of each vertebra from T4 to L4 were measured using a digitizing technique, and the Ha/Hp and Hc/Hp ratios were calculated. The lumbar lordosis angle was measured on the lateral lumbar spine r[iographs. Results. Ha/Hp and Hc/Hp ratios were smaller in men than women by 1.8% and 0.7%, respectively, and these ratios varied with vertebral level. Significant correlations were found between vertebral shape and the lumbar lordosis angle. Conclusions. These results demonstrate that vertebral shape varies significantly with sex, vertebral level and lumbar lordosis angle. Awareness of these relationships may help prevent misdiagnosis in clinical vertebral morphometry. (orig.)

217

Androgenic anabolic steroid exposure during adolescence: Ramifications for brain development and behavior  

OpenAIRE

Puberty is a critical period for brain maturation that is highly dependent on gonadal sex hormones. Modifications in the gonadal steroid environment, via the use of anabolic androgenic steroids (AAS), have been shown to affect brain development and behavior. Studies in both humans and animal models indicate that AAS exposure during adolescence alters normal brain remodeling, including structural changes and neurotransmitter function. The most commonly reported behavioral effect is an increase...

Cunningham, Rebecca L.; Lumia, Augustus R.; Mcginnis, Marilyn Y.

2012-01-01

218

A simple method for measuring sex-hormone binding protein (SHBP) - typical values in men and women and in pregnant women  

International Nuclear Information System (INIS)

Assuming that the binding forces between steroid hormones and their binding proteins are similar to those between antigens and their antibodies, the authors describe how to determine SHBP activity by a dilution method analogous to that used for titration of antisera in radioimmunoassay. The method consists of the following stages: (1) plasma dilution; (2) incubation of the dilution with 20,000dis/min of 1,2-3H-testosterone; (3) separation of the fraction of tracer bound to the SHBP by precipitation with ammonium sulphate; (4) centrifugation and measurement of the supernatant; and (5) plotting of the results on a graph where the axis of ordinates represents the quotient given by bound steroid over free steroid (U/L) and the abscissa represents the plasma dilutions. The values are expressed as the 50% bound titre. An advantage of the method is the higher sensitivity of the dilution curves in the steepest part where the 50% bound is encountered; it is thus not necessary to use the saturation part of the curves where sensitivity is lost owing to the steeper slope. A further advantage of the method is that there is no need for costly processes such as dialysis. The SHBP values obtained for healthy subjects were as follows: 1/5 for men, 1/93 for women, and 1/360 in pregnant women. These physiological values showed no overlapping. (author)

219

Physicochemical and biological properties of new steroid metal complexes  

International Nuclear Information System (INIS)

The aim of this investigation was to prepare stable steroid metal chelates by chemical conversion of the natural steroid hormones testerone, 5?-dihydrotestosterone (5?-DHT) and estradiol and to characterize these by means of their spectroscopic and other physico-chemical properties. In addition, various measuring techniques for the qualitative and quantitative study of complex stabilities and hydrolytic properties were employed. The distribution of some tritiated steroid metal complexes in the tissues of rats was tested using whole animal autoradiography, mainly with a view to identifying whether selective concentration occurs in certain organs. (orig.)

220

Steroids 54. Amino acylamidosteroids.  

Science.gov (United States)

Aminosteroids were prepared and acylated with protected amino acids by means of the mixed anhydride or the active ester method. The tert-butyloxycarbonyl- (BOC) protecting group was eliminated by acidolysis, and the benzyloxycarbonyl- (Z) group by catalytic hydrogenation. 3 beta- and 6 beta-Glycylamidosteroids were prepared by indirect amination of chloroacetamido derivatives, formed by the Ritter reaction on the corresponding 3 alpha,5 alpha-cyclo and 5 alpha,6 alpha-epoxy steroids. Water-soluble double salts were produced from the compounds for pharmacological investigations. PMID:8987138

Vincze, I; Hackler, L; Szendi, Z; Schneider, G

1996-12-01

221

Steroids/Nutritional Supplements/Antibiotics  

Science.gov (United States)

Steroids/Nutritional Supplements/Antibiotics There are multiple steroid/supplemental treatments for Duchenne although there is little agreement ( ... creatine and Duchenne continue. back to top Anabolic steroids These, which act to build tissues in the ...

222

Yolk-albumen testosterone in a lizard with temperature-dependent sex determination: relation with development.  

Science.gov (United States)

The leopard gecko (Eublepharis macularius) exhibits temperature-dependent sex determination as well as temperature-influenced polymorphisms. Research suggests that in oviparous reptiles with temperature-dependent sex determination, steroid hormones in the yolk might influence sex determination and sexual differentiation. From captive leopard geckos that were all from the same incubation temperature regime, we gathered freshly laid eggs, incubated them at one of two female-biased incubation temperatures (26 or 34°C), and measured testosterone content in the yolk-albumen at early or late development. No differences in the concentration of testosterone were detected in eggs from different incubation temperatures. We report testosterone concentrations in the yolk-albumen were higher in eggs of late development than early development at 26°C incubation temperatures, a finding opposite that reported in other TSD reptiles studied to date. PMID:23467072

Huang, Victoria; Bowden, Rachel M; Crews, David

2013-06-01

223

Roles of Steroids in Nematodes  

Science.gov (United States)

The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

224

Role of Steroids in COPD  

OpenAIRE

There has been a lot of debate regarding the role of steroids in the management of Chronic Obstructive Pulmonary Disease. Now with a better understanding of the pathophysiology of COPD, the role of steroids in the management of COPD has become clearer.

Vishnu Sharma

2002-01-01

225

2,3,7,8-Tetrachlorodibenzo-p-dioxin activates the aryl hydrocarbon receptor and alters sex steroid hormone secretion without affecting growth of mouse antral follicles in vitro.  

Science.gov (United States)

The persistent environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an ovarian toxicant. These studies were designed to characterize the actions of TCDD on steroidogenesis and growth of intact mouse antral follicles in vitro. Specifically, these studies tested the hypothesis that TCDD exposure leads to decreased sex hormone production/secretion by antral follicles as well as decreased growth of antral follicles in vitro. Since TCDD acts through binding to the aryl hydrocarbon receptor (AHR), and the AHR has been identified as an important factor in ovarian function, we also conducted experiments to confirm the presence and activation of the AHR in our tissue culture system. To do so, we exposed mouse antral follicles for 96 h to a series of TCDD doses previously shown to have effects on ovarian tissues and cells in culture, which also encompass environmentally relevant and pharmacological exposures (0.1-100 nM), to determine a dose response for TCDD in our culture system for growth, hormone production, and expression of the Ahr and Cyp1b1. The results indicate that TCDD decreases progesterone, androstenedione, testosterone, and estradiol levels in a non-monotonic dose response manner without altering growth of antral follicles. The addition of pregnenolone substrate (10 ?M) restores hormone levels to control levels. Additionally, Cyp1b1 levels were increased by 3-4 fold regardless of the dose of TCDD exposure, evidence of AHR activation. Overall, these data indicate that TCDD may act prior to pregnenolone formation and through AHR transcriptional control of Cyp1b1, leading to decreased hormone levels without affecting growth of antral follicles. PMID:22483799

Karman, Bethany N; Basavarajappa, Mallikarjuna S; Craig, Zelieann R; Flaws, Jodi A

2012-05-15

226

ANABOLIC ANDROGENIC STEROIDS AND DEPENDENCE  

Directory of Open Access Journals (Sweden)

Full Text Available Anabolic androgenic steroids are used for sportive, cosmetic, therapeutic and occupational reasons and there are many side effects reported (George, 2005; Nieminen et al., 1996; O'Sullivan et al., 2000. Prevalence of anabolic steroids’ use also indicates the importance of this topic. Moreover, it is now known that use of anabolic steroids could lead to dependence which could be psychological or/and physiological (Copeland et al., 2000. It isimportant to know about all aspects of anabolic steroids including dependence. Therefore, this study has attempted to give an insight into use of anabolic steroids and dependence. The discussion will focus on prevalence, reasons, and side effects of use and physiological and psychological dependence

IHSAN SARI

2010-12-01

227

Continuous microbiological transformation of steroids.  

Science.gov (United States)

Continuous fermentation trials on the bioconversions of pregnadiene to pregnatriene by Septomyxa affinis and progesterone to 11alpha-hydroxyprogesterone by Rhizopus nigricans were conducted successfully in an eight-stage pilot plant reactor. The first stage was used as the mycelial growth stage while the steroid solutions were added continuously to stage 2, thus using the remaining stages as conversion vessels. Recoveries of 50 to 60% oxidized steroid (based on total steroid supplied) were obtained in both cases upon a contact time of 5 hr between mycelium and steroid. Longer contact times resulted in a gradual net loss of steroid. It was concluded that two-stage reactors (one growth stage and one conversion stage) were adequate for efficient continuous operation of such processes. The reaction volumes of both stages have to be kept in proper balance to insure optimal holdup times for both the cell growth and conversion steps. PMID:13740999

REUSSER, F; KOEPSELL, H J; SAVAGE, G M

1961-07-01

228

A rare occurrence of a malignant ovarian steroid cell tumor not otherwise specified: A case report and literature review.  

Science.gov (United States)

Steroid cell tumors not otherwise specified (NOS) are a rare subgroup of sex cord-stromal tumors. The tumors can occur at any age, although the mean age of occurrence is 43 years old. The majority are benign, but have the capability of producing one or more steroids associated with virilization. The present study reports the case of a 29-year-old female who presented to the Second Xiangya Hospital suffering from lower back and leg pain that had persisted for five months. The patient had regular menstrual cycles and no virilization symptoms were present. Laboratory investigations revealed normal hormone levels. Multiple areas of bone destruction and a right ovarian mass were confirmed via positron emission tomography/computed tomography. The patient underwent an exploratory laparotomy, and a mass measuring ~6 cm in diameter was subsequently identified in the right ovary. A right salpingo-oophorectomy and pelvic washings for cytology were performed. Histopathological studies confirmed the diagnosis of a malignant steroid cell tumor NOS of the right ovary. The patient underwent eight cycles of chemotherapy (docetaxel, 120 mg and nedaplatin, 80 mg). The patient continued to have relatively good health, with no deterioration of the condition for one year and a half, however, the disease progressed and the patient succumbed to brain metastases six months later. PMID:25009655

Li, Kai; Zhu, Fufan; Xiong, Jing; Liu, Fengying

2014-08-01

229

Steroid withdrawal in renal transplantation.  

Science.gov (United States)

Over the last decade, steroid minimization became one of the major goals in pediatric renal transplantation. Different protocols have been used by individual centers and multicenter study groups, including early and late steroid withdrawal or even complete avoidance. The timing of steroid withdrawal determines if antibodies are used, as avoidance and early withdrawal require antibody induction, while late withdrawal typically does not. A monoclonal antibody was used in most protocols during an early steroid withdrawal together with tacrolimus and mycophenolate mofetil in low immunological risk patients. Polyclonal induction was reported as effective in high-risk patients. Cyclosporine A and mycophenolate mofetil were used in late steroid withdrawal with no induction. All described protocols were effective in terms of preventing acute rejection and preserving renal graft function. There was no superiority of any specific protocol in terms of clinical benefits of steroid withdrawal. Pre-puberty determined growth benefit while other clinical advantages, including better control of glycemia, lipids, and blood pressure, were age independent. It is not clear whether the steroid withdrawal increases the risk of recurrence of primary glomerular diseases post-transplant, however it cannot be excluded. There is no evidence to date for a higher risk of anti-HLA production in steroid-free children after renal transplantation. Key summary points--Current strategies to minimize the steroid-related adverse effects in pediatric renal graft recipients include steroid withdrawal, early or late after transplantation, or complete steroid avoidance--Early steroid withdrawal or avoidance is generally used following the induction therapy with mono- or polyclonal antibodies, while in late steroid withdrawal induction therapy was generally not used- Elimination of steroids (early or late) does not increase the risk of acute rejection and does not deteriorate long-term renal graft function- Early steroid withdrawal is possible in patients at high immunological risk using a combination of polyclonal antibody induction, tacrolimus, and mycophenolate mofetil- All protocols of steroid minimization showed relevant clinical benefits, however the growth-related benefit was limited to pre-pubertal patients in all but one of the studies- Adverse events of steroid withdrawal occurred in a higher incidence of post-transplant bone marrow suppression Key research points - There is no clear evidence of the impact of steroid withdrawal on the risk of recurrence of primary glomerulonephritis after renal transplantation in children, therefore further evaluation of this important issue should be performed in prospective trials- There is limited pediatric data on the risk of anti-HLA/donor-specific antibody production in steroid-free patients after renal transplantation. It is not clear whether the selection of the type of induction antibody (lymphocyte depleting versus short, two-dose administration of anti-IL2R inhibitor) is important in this term. The production of anti-HLA antibodies should then be monitored on a regular basis and analyzed in prospective trials. PMID:23288351

Grenda, Ryszard

2013-11-01

230

The role of steroids in follicular growth  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The steroidogenic pathway within the ovary gives rise to progestins, androgens and oestrogens, all of which act via specific nuclear receptors to regulate reproductive function and maintain fertility. The role of progestins in follicular growth and development is limited, its action confined largely to ovulation, although direct effects on granulosa cell function have been reported. Consistent with these findings, progesterone receptor knockout mice are infertile because they cannot ovulate. Androgens have been shown to promote early follicular growth, but also to impede follicular development by stimulating atresia and apoptosis. The inability of androgens to transduce a signal in mice lacking androgen receptors culminates in reduced fertility. Oestrogens are known to exert effects on granulosa cell growth and differentiation in association with gonadotrophins. Studies with oestrogen receptor knockouts and oestrogen depleted mice have shown us that oestrogen is essential for folliculogenesis beyond the antral stage and is necessary to maintain the female phenotype of ovarian somatic cells. In summary, the action of steroids within the ovary is based on the developmental status of the follicle. In the absence of any single sex steroid, ovarian function and subsequently fertility, are compromised.

Drummond Ann E

2006-04-01

231

Quantitative measure of sexual selection with respect to the operational sex ratio: a comparison of selection indices  

Science.gov (United States)

Despite numerous indices proposed to predict the evolution of mating systems, a unified measure of sexual selection has remained elusive. Three previous studies have compared indices of sexual selection under laboratory conditions. Here, we use a genetic study to compare the most widely used measures of sexual selection in natural populations. We explored the mating and reproductive successes of male and female bank voles, Clethrionomys glareolus, across manipulated operational sex ratios (OSRs) by genotyping all adult and pup bank voles on 13 islands using six microsatellite loci. We used Bateman's principles (Is and I and Bateman gradients) and selection coefficients (s? and ??) to evaluate, for the first time, the genetic mating system of bank voles and compared these measures with alternative indices of sexual selection (index of monopolization and Morisita's index) across the OSRs. We found that all the sexual selection indices show significant positive intercorrelations for both males and females, suggesting that Bateman's principles are an accurate and a valid measure of the mating system. The Bateman gradient, in particular, provides information over and above that of other sexual selection indices. Male bank voles show a greater potential for sexual selection than females, and Bateman gradients indicate a polygynandrous mating system. Selection coefficients reveal strong selection gradients on male bank vole plasma testosterone level rather than body size. PMID:17134998

Mills, Suzanne C; Grapputo, Alessandro; Koskela, Esa; Mappes, Tapio

2006-01-01

232

Prenatal sex determination by radioimmunoassay of testosterone with and without chromatography of the amniotic fluid  

International Nuclear Information System (INIS)

Amniotic fluid testosterone measured by radioimmunoassay (RIA) without chromatography (immunoreactive testosterone) seems not to be a definitive test for prenatal sex determination in all cases. In this study testosterone (T) levels measured by RIA with chromatography of the amniotic fluid samples were compared with immunoreactive testosterone (iT) values, to determine the predictive accuracy of the two methods. In 111 amniotic fluid samples between 15 and 19 weeks of gestation iT and T were measured parallelly. There are significant differences between iT- and T-means of both sexes (p < 0.001). 95%-confidence limits of iT-values of the male and female fetuses are largely overlapping. In contrast, the overlap of 95%-confidence limits of the T-values is only minor. The measurement of testosterone with chromatography of the amniotic fluid samples shows for prenatal sex determination in over 90% accuracy. This result is due to the elimination of sex-specific differences in crossreacting steroids within the amniotic fluid of both sexes. (orig)

233

Aplicação da Cromatografia Líquida de Alta Performance Como Método Preparativo Para a Dosagem de Esteróides Hormonais Por RIE: Dosagens de 17OH-Progesterona e Diidrotestosterona Preparative HPLC for Steroid Measurements: Determinations of 170H-Progesterone and Dihydrotestosterone  

Directory of Open Access Journals (Sweden)

Full Text Available A dosagem dos esteróides hormonais tem apresentado evolução técnica significativa, sendo os principais esteróides de interesse clínico dosados, atualmente, por métodos simples, rápidos e automatizados. Existe, no entanto, um compromisso em detrimento da exatidão, que é mais evidente na determinação de esteróides de menor concentração relativa e maior número de interferentes potenciais, como a 17-hidroxiprogesterona (17OHP, a diidrotestosterona (DHT e outros. Nestes casos, um processo preparativo versátil e robusto é fundamental para garantir resultados com alto grau de exatidão. Apresentamos a padronização de um processo preparativo baseado em cromatografia líquida de alta performance (HPLC comparado à cromatografia em coluna de celite para a dosagem de 17OHP e DHT. Os anticorpos empregados nos respectivos radioimunoensaios apresentam especificidade semelhante aos descritos na literatura. As amostras foram inicialmente extraídas em éter etílico e em seguida submetidas ao processo cromatográfico. Amostras de soro provenientes da rotina foram dosadas em paralelo pelos dois métodos, sendo 57 amostras para 17OHP e 84 para DHT. Não houve diferença significativa entre os resultados, e os índices de correlação foram elevados (R= 0,95 e 0,97. Os resultados comprovam que a aplicação do HPLC é válida, além de ser mais reprodutível, versátil e menos operador-dependente. Sua aplicação mais ampla permitirá uma melhora de exatidão na dosagem de esteróides de baixa concentração relativa, onde os métodos mais simples resultam em valores falsamente elevados.Measurement of steroid hormones has undergone a significant technical evolution so that steroids with greater clinical interest are, nowadays, measured with methods that are simple, fast and prone to automation. Nevertheless, a compromise is made in detriment of accuracy, which is more evident with steroids with lower concentration and more potential interferents, as 17-hydroxyprogesterone (17OHP, dihydrotestosterone (DHT, and others. In such cases, a robust and versatile preparative process is of utmost importance to warrant results with the highest degree of accuracy. In this paper we present the results obtained with the use of a preparative process based on high-pressure chromatography (HPLC for the measurement of 17OHP and DHT, as compared with a process based on celite column chromatography. The antibodies used in the radioimmunoassays have similar specificity to those previously described for these kinds of assays. Samples were initially extracted in ethyl ether and then submitted to HPLC. Routine samples (57 for 17OHP and 84 for DHT were measured in parallel with both methods. The differences between results were not statistically significant, and the correlation indexes were high (R= 0.95 and 0.97. Our results confirm that systems based on HPLC are valid, besides being more robust, versatile and operator independent. A more pervasive application of HPLC preparation systems will allow an improvement in the accuracy of steroid measurements, specially those with low concentrations, where simple preparative processes result in falsely elevated results.

José Gilberto H. Vieira

2002-02-01

234

Aplicação da Cromatografia Líquida de Alta Performance Como Método Preparativo Para a Dosagem de Esteróides Hormonais Por RIE: Dosagens de 17OH-Progesterona e Diidrotestosterona / Preparative HPLC for Steroid Measurements: Determinations of 170H-Progesterone and Dihydrotestosterone  

Scientific Electronic Library Online (English)

Full Text Available A dosagem dos esteróides hormonais tem apresentado evolução técnica significativa, sendo os principais esteróides de interesse clínico dosados, atualmente, por métodos simples, rápidos e automatizados. Existe, no entanto, um compromisso em detrimento da exatidão, que é mais evidente na determinação [...] de esteróides de menor concentração relativa e maior número de interferentes potenciais, como a 17-hidroxiprogesterona (17OHP), a diidrotestosterona (DHT) e outros. Nestes casos, um processo preparativo versátil e robusto é fundamental para garantir resultados com alto grau de exatidão. Apresentamos a padronização de um processo preparativo baseado em cromatografia líquida de alta performance (HPLC) comparado à cromatografia em coluna de celite para a dosagem de 17OHP e DHT. Os anticorpos empregados nos respectivos radioimunoensaios apresentam especificidade semelhante aos descritos na literatura. As amostras foram inicialmente extraídas em éter etílico e em seguida submetidas ao processo cromatográfico. Amostras de soro provenientes da rotina foram dosadas em paralelo pelos dois métodos, sendo 57 amostras para 17OHP e 84 para DHT. Não houve diferença significativa entre os resultados, e os índices de correlação foram elevados (R= 0,95 e 0,97). Os resultados comprovam que a aplicação do HPLC é válida, além de ser mais reprodutível, versátil e menos operador-dependente. Sua aplicação mais ampla permitirá uma melhora de exatidão na dosagem de esteróides de baixa concentração relativa, onde os métodos mais simples resultam em valores falsamente elevados. Abstract in english Measurement of steroid hormones has undergone a significant technical evolution so that steroids with greater clinical interest are, nowadays, measured with methods that are simple, fast and prone to automation. Nevertheless, a compromise is made in detriment of accuracy, which is more evident with [...] steroids with lower concentration and more potential interferents, as 17-hydroxyprogesterone (17OHP), dihydrotestosterone (DHT), and others. In such cases, a robust and versatile preparative process is of utmost importance to warrant results with the highest degree of accuracy. In this paper we present the results obtained with the use of a preparative process based on high-pressure chromatography (HPLC) for the measurement of 17OHP and DHT, as compared with a process based on celite column chromatography. The antibodies used in the radioimmunoassays have similar specificity to those previously described for these kinds of assays. Samples were initially extracted in ethyl ether and then submitted to HPLC. Routine samples (57 for 17OHP and 84 for DHT) were measured in parallel with both methods. The differences between results were not statistically significant, and the correlation indexes were high (R= 0.95 and 0.97). Our results confirm that systems based on HPLC are valid, besides being more robust, versatile and operator independent. A more pervasive application of HPLC preparation systems will allow an improvement in the accuracy of steroid measurements, specially those with low concentrations, where simple preparative processes result in falsely elevated results.

José Gilberto H., Vieira; Odete H., Nakamura; Keiko O., Noguti.

2002-02-01

235

Sex Hormones as Potential Modulators of Vascular Function in Hypertension  

OpenAIRE

The greater incidence of hypertension in men and postmenopausal women compared with premenopausal women has suggested gender differences in vascular function. Vascular effects of the female sex hormones estrogen and progesterone, and the male hormone testosterone have been described. Sex steroid receptors have been identified in vascular endothelium and smooth muscle. Interaction of sex hormones with cytosolic/nuclear receptors initiates long-term genomic effects that stimulate endothelial ce...

Khalil, Raouf A.

2005-01-01

236

Reactive Arrays of Colorimetric Sensors for Metabolite and Steroid Identification  

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Full Text Available The work described herein examines a rapid mix-and-measure method called DETECHIP suitable for screening of steroids and metabolites. The addition of steroids and metabolites to reactive arrays of colorimetric sensors generated characteristic color “fingerprints” that were used to identify the analyte. A color analysis tool was used to identify the analyte pool that now includes biologically relevant analytes. The mix-and-measure arrays allowed the detection of disease metabolites, orotic acid and argininosuccinic acid; and the steroids androsterone, 1,4-androstadiene, testosterone, stanozolol, and estrone. The steroid 1,4-androstadiene was also detected by this method while dissolved in synthetic urine. Some of the steroids, such as androstadiene, stanozolol, and androsterone were co-dissolved with (2-hydroxypropyl-?-cyclodextrin in order to increase solubility in aqueous buffered solutions. The colorimetric arrays do not intend to eliminate ELISA or mass spectroscopy based screening, but to possibly provide an alternative analytical detection method for steroids and metabolites.

Gary Batres

2014-03-01

237

Steroids in Athletics: One University's Experience.  

Science.gov (United States)

Presents an account of one university's experience in conducting an investigation into possible steroid use by student athletes and the development of a program to deal with the problem. Discusses why athletes use steroids and how steroids are taken. Concludes it is likely many steroid-related deaths of athletes go undetected. (Author/ABL)

Lopez, Mike

1990-01-01

238

A quantitiative LC-MS/MS method for the measurement of arachidonic acid, prostanoids, endocannabinoids, N-acylethanolamines and steroids in human plasma.  

Science.gov (United States)

Free arachidonic acid is functionally interlinked with different lipid signaling networks including those involving prostanoid pathways, the endocannabinoid system, N-acylethanolamines, as well as steroids. A sensitive and specific LC-MS/MS method for the quantification of arachidonic acid, prostaglandin E2, thromboxane B2, anandamide, 2-arachidonoylglycerol, noladin ether, lineoyl ethanolamide, oleoyl ethanolamide, palmitoyl ethanolamide, steroyl ethanolamide, aldosterone, cortisol, dehydroepiandrosterone, progesterone, and testosterone in human plasma was developed and validated. Analytes were extracted using acetonitrile precipitation followed by solid phase extraction. Separations were performed by UFLC using a C18 column and analyzed on a triple quadrupole MS with electron spray ionization. Analytes were run first in negative mode and, subsequently, in positive mode in two independent LC-MS/MS runs. For each analyte, two MRM transitions were collected in order to confirm identity. All analytes showed good linearity over the investigated concentration range (r>0.98). Validated LLOQs ranged from 0.1 to 190ng/mL and LODs ranged from 0.04 to 12.3ng/mL. Our data show that this LC-MS/MS method is suitable for the quantification of a diverse set of bioactive lipids in plasma from human donors (n=32). The determined plasma levels are in agreement with the literature, thus providing a versatile method to explore pathophysiological processes in which changes of these lipids are implicated. PMID:25436483

Gachet, María Salomé; Rhyn, Peter; Bosch, Oliver G; Quednow, Boris B; Gertsch, Jürg

2015-01-22

239

Sex Chromosome  

Science.gov (United States)

A sex chromosome is one of the two chromosomes that specify an organism's genetic sex. Humans have two kinds of sex chromosomes, one called X and the other Y. Normal females possess two X chromosomes and normal males one X and one Y.

Darryl Leja (National Human Genome Research Institute REV)

2005-04-14

240

Impaired hepatic drug and steroid metabolism in congenital adrenal hyperplasia due to P450 oxidoreductase deficiency  

OpenAIRE

Objective: Patients with congenital adrenal hyperplasia due to P450 oxidoreductase (POR) deficiency(ORD) present with disordered sex development and glucocorticoid deficiency. This is due to disruption of electron transfer from mutant POR to microsomal cytochrome P450 (CYP) enzymes that play a key role in glucocorticoid and sex steroid synthesis. POR also transfers electrons to all major drugmetabolizing CYP enzymes, including CYP3A4 that inactivates glucocorticoid and oestrogens. However, wh...

Tomalik-scharte, D.; Maiter, D.; Kirchheiner, J.; Ivison, H. E.; Fuhr, U.; Arlt, Wiebke

2010-01-01

241

Assessment of Borderline Personality Features in Population Samples: Is the Personality Assessment Inventory-Borderline Features Scale Measurement Invariant across Sex and Age?  

Science.gov (United States)

Borderline personality disorder (BPD) is more often diagnosed in women than in men, and symptoms tend to decline with age. Using a large community sample, the authors investigated whether sex and age differences in four main features of BPD, measured with the "Personality Assessment Inventory-Borderline Features" scale (PAI-BOR; Morey, 1991), are…

De Moor, Marleen H. M.; Distel, Marijn A.; Trull, Timothy J.; Boomsma, Dorret I.

2009-01-01

242

History, chemistry and pharmacodynamics of anabolic-androgenic steroids.  

Science.gov (United States)

It had been known for centuries that castration resulted in the loss of certain secondary male sex characteristics. The first inkling as to the cause of these changes were provided in 1849 by a prevention of the regression of the comb and wattles of capons by implantation of testis into the abdominal cavity of the castrated rooster. The results were correctly interpreted that the testis secreted a substance into the blood to regulate the development and maintenance of the male characteristics. The first active extract of testis, however, was not prepared until 1927. Shortly thereafter (1929), a similar type of activity was found in men's urine which was followed (1931) by the isolation of a pure substance, androsterone. A substance with the properties of the testis extract was quickly (1935) synthesized and proved to be identical to a pure substance, testosterone, obtained almost simultaneously from testis extract. Testosterone influences the growth, development, and function of practically every organ in the body. The chemically and endogenously modified steroids do not have parallel effects on the different biological properties of testosterone. Furthermore animal species and dose of steroid affect the response of the different organs. Many chemically modified steroids and some endogenous steroids of both the C19 and C21 series exhibit definite separation of undesirable biological effects. PMID:8256446

Kochakian, C D

1993-01-01

243

Electroimmunoassay of sex hormone binding globulin. Enhanced sensitivity by autoradiography using A-ring 125I-17-?-oestradiol  

International Nuclear Information System (INIS)

Four different 125I-iodinated steroids were tested for their binding to human sex hormone binding globulin (SHBG) using an electrophoretic technique. 17-?-oestradiol iodinated in its A-ring bound with high affinity to SHBG. This radioactive steroid was used to increase the sensitivity of the electroimmunoassay of SHBG by adding the steroid to the samples before electroimmunoassay. The radioactive steroid incorporated into the immunoprecipitates could be observed by autoradiography. The sensitivity of the assay, which employed a rabbit antiserum against purified human SHBG and was standardized with pure SHBG, was about 0.2 mg/1. The coefficient of variation within and between assays was 2.4% and 2.6% respectively, for values within the normal range. The mean SHBG concentration in healthy regularly menstruating women was 3.50 +- 0.74 (SD) mg/1 when measured in plasma, and 3.78 +- 0.80 mg/1 when measured in serum. The corresponding mean concentrations in healthy men were 2.26 +- 0.45 and 2.44 +- 0.49 mg/1. The modified electroimmunoassay described is a simple modification, which increases the sensitivity sufficiently to permit reliable quantification of SHBG over the entire range of concentration which could be relevant in clinical practice. (author)

244

Prenatal sex ratios influence sexual dimorphism in a reptile.  

OpenAIRE

The prenatal environment influences offspring traits in a variety of ways and in a wide range of taxa. For example, maternal allocation of steroids to the eggs influences offspring traits in birds, and in some mammals the intrauterine position influences morphological, behavioural, and physiological traits due to sex-related steroid transfer between sibling fetuses. We show that similar phenomena occur in the common lizard (Lacerta vivipara), a viviparous reptile. Females developing in male-b...

Uller, T.; Olsson, M.

2003-01-01

245

Effect of the Steroidal Saponins of Fructus tribuli on Growth of Three Lactobacillus acidophilus  

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Full Text Available Effect of the steroidal saponins of Fructus tribuli on Growth of Lactobacillus acidophilus LA04, LA05 and LA06 was studied by measuring optical density at 600 nm (OD600 and pH using MRS media as the control. The addition of steroidal saponins (w/v was 0.05, 0.10, 0.15, 0.20 and 0.25%, respectively. Results were as follows: addition of steroidal saponins of Fructus tribuli could promote the growth of Lactobacillus acidophilus A04, LA05 and LA06 and the optimum concentration of steroidal saponins was all 0.25% for the three strains.

He Chen

2014-01-01

246

Sex, hormones and neuroeffector mechanisms.  

Science.gov (United States)

Incidence and rate of cardiovascular disease differ between men and women across the life span. Although hypertension is more prominent in men than women, there is a group of vasomotor disorders [i.e. Raynaud's disease, postural orthostatic tachycardia syndrome and vasomotor symptoms (hot flashes) of menopause and migraine] with a female predominance. Both sex and hormones interact to modulate neuroeffector mechanisms including integrated regulation of the Sry gene and direct effect of sex steroid hormones on synthesis, release and disposition of monoamine neurotransmitters, and distribution and sensitivity of their receptors in brain areas associated with autonomic control. The interaction of the sex chromosomes and steroids also modulates these effector tissues, that is, the heart, vascular smooth muscle and endothelium. Although involvement of central serotonergic centres has been studied in regard to mood disorders such as depression, their contribution to cardiovascular risk is gaining attention. Studies are needed to further evaluate how hormonal treatments and drugs used to modulate adrenergic and serotonergic activity affect progression and risk for cardiovascular disease in men and women. PMID:20874808

Hart, E C; Charkoudian, N; Miller, V M

2011-09-01

247

The steroid hormone ecdysone functions with intrinsic chromatin remodeling factors to control female germline stem cells in Drosophila  

OpenAIRE

Steroid hormones are known systemic regulators of multiple normal and cancerous tissues; however, whether or how they impact the fate and function of adult stem cells is unclear. In the Drosophila ovary, insulin signals modulate the proliferation and self-renewal of germline stem cells (GSCs), yet despite evidence that additional systemic factors control GSC activity, these have remained largely unknown. Here, we report that ecdysone, a steroid hormone structurally related to mammalian sex st...

Ables, Elizabeth T.; Drummond-barbosa, Daniela

2010-01-01

248

Sex Steroids and Prostate Carcinogenesis Integrated, Multifactorial Working Hypothesis  

OpenAIRE

Androgens are thought to cause prostate cancer, but there is little epidemiological support for this notion. Animal studies, however, demonstrate that androgens are very strong tumor promotors for prostate carcinogenesis after tumor-initiating events. Even treatment with low doses of testosterone alone can induce prostate cancer in rodents. Because testosterone can be converted to estradiol-17? by the enzyme aromatase, expressed in human and rodent prostate, estrogen may be involved in prost...

Bosland, Maarten C.

2006-01-01

249

Circulating sex steroids and breast cancer risk in premenopausal women  

OpenAIRE

Evidence from both laboratory and epidemiologic studies indicate a key role of hormones in the etiology of breast cancer. In epidemiologic studies, indirect data, including the consistent associations observed between reproductive factors and breast cancer risk, support an important contribution of hormones to risk. Recently, the associations between circulating hormones in premenopausal women and subsequent risk of breast cancer have been evaluated. To date, both positive and null associatio...

Hankinson, Susan E.; Eliassen, A. Heather

2010-01-01

250

Esophageal lipomatosis: another consequence of the use of steroids  

Energy Technology Data Exchange (ETDEWEB)

After we incidentally found on CT extensive esophageal fat accumulations in a patient with long-term use of steroids, we prospectively evaluated during a 6-month period all CT studies of the chest for esophageal lipomatosis and related the findings to the possible use of steroids. The diagnosis of esophageal fat on CT was made by density measurements or if too small for reliable density measurements by comparison with mediastinal fat. In 21 of 1320 exclusively older male patients the diagnosis of esophageal lipomatosis was definite in 7 and likely in 14 patients. All fat accumulations were located in the upper third of the esophagus (mean length 22 {+-} 6 mm) and presented ring-like (n = 10), irregular (n = 3), or as a horseshoe sparing the posterior border (n = 8). In 20 patients there was an unequivocal history of steroid treatment. Associated centripetal fat infiltration was found in 11 patients. None of the patients had swallowing problems. Prolonged use of steroids, either orally or inhalationally administered, is associated with esophageal lipomatosis. The predisposition for the upper esophagus might be related to the presence of striated muscle cells in this part of the esophagus; moreover, inhalational steroid therapy may adversely affect the upper esophagus. (orig.)

Bogaert, J.; Rosseel, F.; Verhaegen, S.; Verschakelen, J. [University Hospitals Leuven (Belgium). Dept. of Radiology

2000-09-01

251

Esophageal lipomatosis: another consequence of the use of steroids  

International Nuclear Information System (INIS)

After we incidentally found on CT extensive esophageal fat accumulations in a patient with long-term use of steroids, we prospectively evaluated during a 6-month period all CT studies of the chest for esophageal lipomatosis and related the findings to the possible use of steroids. The diagnosis of esophageal fat on CT was made by density measurements or if too small for reliable density measurements by comparison with mediastinal fat. In 21 of 1320 exclusively older male patients the diagnosis of esophageal lipomatosis was definite in 7 and likely in 14 patients. All fat accumulations were located in the upper third of the esophagus (mean length 22 ± 6 mm) and presented ring-like (n = 10), irregular (n = 3), or as a horseshoe sparing the posterior border (n = 8). In 20 patients there was an unequivocal history of steroid treatment. Associated centripetal fat infiltration was found in 11 patients. None of the patients had swallowing problems. Prolonged use of steroids, either orally or inhalationally administered, is associated with esophageal lipomatosis. The predisposition for the upper esophagus might be related to the presence of striated muscle cells in this part of the esophagus; moreover, inhalational steroid therapy may adversely affect the upper esophagus. (orig.)

252

Allergy to ethylenediamine and steroid.  

Science.gov (United States)

Intravenous preparations combining aminophylline and a steroid are used frequently in the treatment of bronchial asthma attacks. However, anaphylactoid reactions to such preparations have been rarely observed. We report the case of a 31-year-old man with aminophylline and steroid allergy. Aminophylline is the ethylenediamine salt of theophylline. In our patient, aminophylline, ethylenediamine and various steroids were found to be positive in the intradermal test. The challenge test with intravenous aminophylline was positive, while that with oral theophylline was negative. Ethylenediamine is used in everyday products such as shellacs and rubber products. In the case of our patient, his asthma worsened following the remodelling of his restaurant. Occupational asthma due to exposure to ethylenediamine is also discussed. PMID:11206939

Asakawa, H; Araki, T; Yamamoto, N; Imai, I; Yamane, M; Tsutsumi, Y; Kawakami, F

2000-01-01

253

Green Light for Steroid Hormones  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. In his Perspective, D. Russell describes two papers--one in this week's issue of Science (Li et al., p. 398) and one in the 19 April issue of Cell (M. Szekeres et al.)--which report on two enzymes that synthesize steroid hormones cloned from Arabidopsis. These enzymes, DET2 and CPD, are in the biosynthetic pathway for brassinolides, steroids that seem to participate in the regulation of gene expression by light.

David W. Russell (University of Texas Southwestern Medical Center; Department of Molecular Genetics)

1996-04-19

254

MEDICAL ISSUES ASSOCIATED WITH ANABOLIC STEROID USE: ARE THEY EXAGGERATED?  

Directory of Open Access Journals (Sweden)

Full Text Available For the past 50 years anabolic steroids have been at the forefront of the controversy surrounding performance enhancing drugs. For almost half of this time no attempt was made by sports governing bodies to control its use, and only recently have all of the major sports governing bodies in North America agreed to ban from competition and punish athletes who test positive for anabolic steroids. These punitive measures were developed with the primary concern for promotion of fair play and eliminating potential health risks associated with androgenic-anabolic steroids. Yet, controversy exists whether these testing programs deter anabolic steroid use. Although the scope of this paper does not focus on the effectiveness of testing, or the issue of fair play, it is of interest to understand why many athletes underestimate the health risks associated from these drugs. What creates further curiosity is the seemingly well-publicized health hazards that the medical community has depicted concerning anabolic steroidabuse. Is there something that the athletes know, or are they simply naïve regarding the dangers? The focus of this review is to provide a brief history of anabolic steroid use in North America, the prevalence of its use in both athletic and recreational populations and its efficacy. Primary discussion will focus on health issues associated with anabolic steroid use with an examination of the contrasting views held between the medical community and the athletes that are using these ergogenic drugs. Existing data suggest that in certain circumstances the medical risk associated with anabolic steroid use may have been somewhat exaggerated, possibly to dissuade use in athletes

Jay R. Hoffman

2006-06-01

255

Steroid Injections for the Carpal Tunnel Syndrome  

Science.gov (United States)

Steroid Injections for the Carpal Tunnel Syndrome The full report is titled “Methylprednisolone Injections for the Carpal ... treatment is wrist splinting. When splinting is ineffective, steroid injections are often given and provide relief. However, ...

256

Critical behavior near the Lifshitz point in Sn2P2(S1-xSex)6 ferroelectric semiconductors from thermal diffusivity measurements  

International Nuclear Information System (INIS)

The thermal diffusivity of the ferroelectric family Sn2P2(SexS1-x)6 (0 ? x ? 1) has been measured by a high-resolution ac photopyroelectric technique, using single crystals, with the aim of studying the evolution of the ferroelectric transition with Se doping. Its change from second order character to first order while passing the Lifshitz point (x?0.28) has been evaluated, as well as the splitting of the transition at high Se concentrations. The critical behavior of the ferroelectric transition in terms of the different universality classes and their underlying physical dominant effects (tricriticality, long-range dipole interactions, Lifshitz point) has been discussed using thermal diffusivity measurements in the very close vicinity of the critical temperature. This study reveals that for Se concentrations around the Lifshitz point, long-range dipole interactions do not play a significant role and that the critical parameters are close to those predicted for the Lifshitz universality class.

257

New steroid derivative with hypoglycemic activity  

OpenAIRE

Data indicates that some steroid derivatives may induce changes on glucose levels; nevertheless, data are very confusing. Therefore, more pharmacological data are needed to characterize the activity induced by the steroid derivatives on glucose levels. The aim of this study was to synthesize a new steroid derivative for evaluate its hypoglycemic activity. The effects of steroid derivative on glucose concentration were evaluated in a diabetic animal model using glibenclamide and metformin as c...

Lauro, Figueroa-valverde; Francisco, Di?az-cedillo; Lenin, Hau-heredia; Elodia, Garci?a-cervera; Eduardo, Pool-go?mez; Marcela, Rosas-nexticapa; Bety, Sarabia-alcocer

2014-01-01

258

Adolescents and Steroids: A User Perspective.  

Science.gov (United States)

Anabolic-androgenic steroids ("steroids") are synthetic derivatives of the natural male hormone testosterone. They were first used non-medically by elite athletes seeking to improve performance. More recently, however, steroid use has filtered down to high school and junior high school levels. The purpose of this study was to describe adolescent…

Office of Inspector General (DHHS), Washington, DC.

259

Steroidal Triterpenes of Cholesterol Synthesis  

Directory of Open Access Journals (Sweden)

Full Text Available Cholesterol synthesis is a ubiquitous and housekeeping metabolic pathway that leads to cholesterol, an essential structural component of mammalian cell membranes, required for proper membrane permeability and fluidity. The last part of the pathway involves steroidal triterpenes with cholestane ring structures. It starts by conversion of acyclic squalene into lanosterol, the first sterol intermediate of the pathway, followed by production of 20 structurally very similar steroidal triterpene molecules in over 11 complex enzyme reactions. Due to the structural similarities of sterol intermediates and the broad substrate specificity of the enzymes involved (especially sterol-?24-reductase; DHCR24 the exact sequence of the reactions between lanosterol and cholesterol remains undefined. This article reviews all hitherto known structures of post-squalene steroidal triterpenes of cholesterol synthesis, their biological roles and the enzymes responsible for their synthesis. Furthermore, it summarises kinetic parameters of enzymes (Vmax and Km and sterol intermediate concentrations from various tissues. Due to the complexity of the post-squalene cholesterol synthesis pathway, future studies will require a comprehensive meta-analysis of the pathway to elucidate the exact reaction sequence in different tissues, physiological or disease conditions. A major reason for the standstill of detailed late cholesterol synthesis research was the lack of several steroidal triterpene standards. We aid to this efforts by summarizing commercial and laboratory standards, referring also to chemical syntheses of meiosis-activating sterols.

Damjana Rozman

2013-04-01

260

Influence of Music on Steroid Hormones and the Relationship between Receptor Polymorphism and Musical Ability: a Pilot Study  

Directory of Open Access Journals (Sweden)

Full Text Available Studies have shown that music confers plasticity to the brain. In a preliminary pilot study, we examined the effect of music listening on steroid hormones and the relationship between steroid hormone receptor polymorphisms and musical ability. Twenty-one subjects (10 males and 11 females were recruited and divided into musically talented and control groups. The subjects selected (1 music they preferred (chill-inducing music and (2 music they did not like. Before and after the experiments, saliva was collected to measure the levels of steroid hormones such as testosterone, estradiol, and cortisol. DNA was also isolated from the saliva samples to determine the androgen receptor and arginine vasopressin receptor 1A genotypes. Advanced Measures of Music Audiation (AMMA was used to determine the musical ability of the subjects. With both types of music, the cortisol levels decreased significantly in both sexes. The testosterone (T levels declined in males when they listened to both types of music. In females, the T levels increased in those listening to chill-inducing music but declined when they listened to music they disliked. However, these differences were not significant. The 17-beta estradiol levels increased in males with both types of music, whereas the levels increased with chill-inducing music but declined with disliked music in females. The AMMA scores were higher for the short repeat length-type AR than for the long repeat length-type. Comparisons of AR polymorphisms and T levels before the experiments showed that the T levels were within the low range in the short repeat length-type group and there was a positive relationship with the repeat length, although it was not significant. This is the first study conducted in humans to analyze the relationships between the AR gene, T levels, and musical ability.

HajimeFukui

2013-12-01

261

Steroid radioimmunoassay: contribution of standards to blank values, ch. 4  

International Nuclear Information System (INIS)

The sensitivity of the radioimmunoassay of steroids is considerably reduced by high blank values which may be derived in part from co-chromatographed standards. Blank levels approach the detection limit of the radioimmunoassay of aldosterone, testosterone and androstenedione when 10,000 dpm (30-35 pg) labelled steroids are used as reference standard. When 20 ?g aldosterone, testosterone, or androstenedione is used as standard, blank levels of up to 12,800 pg were measured in the radioimmunoassay. Application of the standards on a separate strip does not improve the results. From the experiments it appeared that contamination took place by transport by the solvent

262

Differential responses to steroid hormones in fibroblasts from the vocal fold, trachea, and esophagus.  

Science.gov (United States)

There is accumulating evidence that fibroblasts are target cells for steroids such as sex hormones and corticoids. The characteristics of fibroblasts vary among tissues and organs. Our aim in this study is to examine differences in responses to steroid hormones among fibroblasts from different cervicothoracic regions. We compared the actions of steroid hormones on cultured fibroblasts from the vocal folds, which are considered to be the primary target of steroid hormones, and the trachea and esophagus in adult male rats. Expression of steroid hormone receptors (androgen receptor, estrogen receptor ?, and glucocorticoid receptor) was identified by immunofluorescence histochemistry. Androgen receptor was much more frequently expressed in fibroblasts from the vocal fold than in those from the trachea and esophagus. Cell proliferation analysis showed that administration of testosterone, estradiol, or corticosterone suppressed growth of all 3 types of fibroblasts. However, mRNA expression for extracellular matrix-associated genes, including procollagen I and III and elastin, and hyaluronic acid synthase I was elevated only by addition of testosterone to fibroblasts from the vocal fold. These results indicate that each steroid hormone exerts region-specific effects on cervicothoracic fibroblasts with different properties through binding to specific receptors. PMID:25514085

Mukudai, Shigeyuki; Matsuda, Ken Ichi; Nishio, Takeshi; Sugiyama, Yoichiro; Bando, Hideki; Hirota, Ryuichi; Sakaguchi, Hirofumi; Hisa, Yasuo; Kawata, Mitsuhiro

2015-03-01

263

Environmental sex determination mechanisms in reptiles.  

Science.gov (United States)

Temperature-dependent sex determination (TSD) was first discovered in reptiles. Since then, a great diversity of sex-determining responses to temperature has been reported. Higher temperatures can produce either males or females, and the temperature ranges and lengths of exposure that influence TSD are remarkably variable among species. In addition, transitory gene regulatory networks leading to gonadal TSD have evolved. Although most genes involved in gonadal development are conserved in vertebrates, including TSD species, temporal and spatial gene expression patterns vary among species. Despite variation in TSD pattern and gene expression heterochrony, the structural framework, the medullary cords, and cortex of the bipotential gonad have been strongly conserved. Aromatase (CYP19), which regulates gonadal estrogen levels, is proposed to be the main target of a putative thermosensitive factor for TSD. However, manipulation of estrogen levels rarely mimics the precise timing of temperature effects on expression of gonadal genes, as occurs with TSD. Estrogen levels may influence sex determination or gonad differentiation depending on the species. Furthermore, the process leading to sex determination under the influence of temperature poses problems that are not encountered by species with genetic sex determination. Yolk steroids of maternal origin and steroids produced by the embryonic nervous system should also be considered as sources of hormones that may play a role in TSD. PMID:22948613

Merchant-Larios, H; Díaz-Hernández, V

2013-01-01

264

Condom Use at Last Sex as a Proxy for Other Measures of Condom Use: Is It Good Enough?  

Science.gov (United States)

Condom use at last sex is a widely used indicator in sexual behavior research; however, there is little empirical research validating this indicator. This study examined whether a single-event recall period (the last time coitus occurred) was consistent with longer recall periods (14 days and 60 days) for a sample of African American adolescent…

Younge, Sinead N.; Salazar, Laura F.; Crosby, Richard F.; DiClemente, Ralph J.; Wingood, Gina M.; Rose, Eve

2008-01-01

265

Sex Determination from Occipital Condylar Measurements by Baudoin Index in Forensic Purposes / Determinación del Sexo desde Mediciones del Cóndilo Occipital Mediante el Índice de Baudoin con Propósitos Forenses  

Scientific Electronic Library Online (English)

Full Text Available En la identificación de personas con fines forenses el sexo es una de las características más importantes y primordiales a evaluar en cada caso. El índice condilar Baudoin es un método de determinación del sexo basado en mediciones de la longitud y la anchura del cóndilo occipital. El objetivo de es [...] ta investigación fue aplicar el índice condilar de Baudoin para la determinación del sexo, y evaluar su fiabilidad. La muestra fue compuesta de 100 cráneos humanos brasileños, 50 hombres y 50 mujeres del cementerio São Gonçalo, ciudad de Cuiabá, Brasil. Los valores de medición se analizaron estadísticamente con el fin de comparar la tasa de coincidencia para cada sexo, cada lado, además de la media general. Los resultados mostraron que el porcentaje general de éxito en la aplicación del índice de Baudoin fue de 44,83% para los hombres y 51,93% para las mujeres, lo que asciende a una coincidencia del 47,5%. La precisión del índice de Baudoin para la determinación del sexo fue bastante baja para esta muestra brasileña, por lo que este método debe ser considerado como criterio para determinar el sexo de los cráneos en un contexto forense. Abstract in english In human identification for forensic purposes the sex is one of the most important and first features to be assessed in each case. Baudoin condylar index is a sex determination method based on measurements of length and width of the occipital condyle. The aim of this research was to apply the Baudoi [...] n condylar index for sex determination, and evaluate its reliability. The sample was composed of 100 Brazilian human skulls, 50 male and 50 female from São Gonçalo cemetery, City of Cuiabá, Brazil. The measurement values were statistically analyzed in order to compare the matching rate for each sex, each side, as well as the overall average. The results showed that the overall percentage of success in applying the Baudoin index was 44.83% to males, and 51.93% to females, amounting to 47.5% matching. The accuracy of the Baudoin index to sex determination was quite low for this Brazilian sample, the reason why this method should be disregarded as a criterion to sexing skulls in a forensic context.

Osvaldo Fortes de, Oliviera; Rachel Lima Ribeiro, Tinoco; Eduardo, Daruge Júnior; Laís Gomes de, Araujo; Ricardo Henrique Alves da, Silva; Luiz Renato, Paranhos.

1297-13-01

266

Safe sex  

Science.gov (United States)

There are many diseases that humans can contract through sexual contact with each other. Humans can lower their risk of contracting these diseases by practicing safe sex techniques if they choose to participate in those kinds of actions.

Olivia Worland (Purdue University; Biological Sciences)

2008-07-09

267

Sex determination  

OpenAIRE

How the sex of offspring is determined has puzzled philosophers and scientists for millennia. Modern science has identified both genetic and environmental factors, but the question is still not yet fully answered.

Mccullagh, W. Mck H.

2013-01-01

268

Sex work and sex trafficking.  

Science.gov (United States)

Preventing HIV infection and other sexually transmitted diseases (STDs), as well as sexual and physical violence, are major occupational health and safety concerns for prostitutes. Considerable evidence shows that anti-prostitution laws facilitate violence and abuse against prostitutes and may increase their risk of contracting HIV/STDs. For example, police often take advantage of existing laws against prostitution to demand money or sex. In general, the strict enforcement of anti-prostitution laws marginalizes prostitutes from services which could help them avoid abuse and promotes an environment in which prostitutes must take risks to avoid detection and arrest. One strategy to improve prostitutes' lives would therefore be to remove laws which prevent them from working safely and from travelling abroad to work legally. Projects in which prostitutes are actively involved have helped break down stereotypes against prostitutes, while police-sex worker liaison projects in Scotland and Australia have led to higher levels of reporting of crimes against prostitutes. The Network of Sex Work Projects (NSWP), an organization which links sex worker health programs around the world, has found that the incidence of HIV/STDs among prostitutes is lowest when they have control over their work conditions; access to condoms, lubricants, and other safe sex materials; and respect of their basic human and legal rights. People need to understand that consensual involvement in sex work is different from forced sex trafficking. PMID:12348692

Ditmore, M; Saunders, P

1998-01-01

269

Endocrine Correlates of Musth in Free-Ranging Asian Elephants (Elephas maximus) Determined by Non-Invasive Faecal Steroid Hormone Metabolite Measurements  

OpenAIRE

The occurrence of musth, a period of elevated levels of androgens and heightened sexual activity, has been well documented for the male Asian elephant (Elephas maximus). However, the relationship between androgen-dependent musth and adrenocortical function in this species is unclear. The current study is the first assessment of testicular and adrenocortical function in free-ranging male Asian elephants by measuring levels of testosterone (androgen) and cortisol (glucocorticoid - a physiologic...

Ghosal, Sukumar; Ganswindt, Andre; Seshagiri, Polani B.; Sukumar, Raman

2013-01-01

270

Comparison of steroid pulse therapy and conventional oral steroid therapy as initial treatment for autoimmune pancreatitis  

International Nuclear Information System (INIS)

The efficacy of oral steroid therapy for autoimmune pancreatitis (AIP) is well known, and oral prednisolone treatment is most usually commenced at 30-40 mg/day, but there have been few reports about comparative studies of oral steroid therapy and steroid pulse therapy as the initial treatment for AIP. We studied the clinical course and image findings to estimate the utility of steroid pulse therapy for AIP, comparing it with oral steroid therapy. Laboratory and image findings were assessed retrospectively in 11 patients who received steroid pulse therapy, and the findings were compared to those in 10 patients who received conventional oral steroid therapy. Change in pancreatic size showed no significant difference between the therapies after 2 weeks of treatment. Significant improvement of lower bile duct strictures after 2 weeks of treatment and that of immunoglobulin values within 6 months were shown with both therapies. However, steroid pulse therapy showed significant improvement of ?-guanosine triphosphate (GTP) in 2 weeks and of alanine aminotransferase (ALT) in 2 and 8 weeks, compared with oral steroid therapy. Moreover, there was one patient in whom the lower bile duct stricture was not improved by oral steroid therapy, but it did show improvement with steroid pulse therapy. Initial steroid pulse therapy is a beneficial alternative to oral steroid therapy for the improvement of bile duct lesions. In future, the accumulation of a larger number of patients receation of a larger number of patients receiving steroid pulse therapy is needed, and prospective studies will be required. (author)

271

Sumoylated PPAR? mediates sex-specific gene repression and protects the liver from estrogen-induced toxicity in mice  

OpenAIRE

As most metabolic studies are conducted in male animals, understanding the sex specificity of the underlying molecular pathways has been broadly neglected; for example, whether PPARs elicit sex-dependent responses has not been determined. Here we show that in mice, PPAR? has broad female-dependent repressive actions on hepatic genes involved in steroid metabolism and immunity. In male mice, this effect was reproduced by the administration of a synthetic PPAR? ligand. Using the steroid oxyst...

Leuenberger, Nicolas; Pradervand, Sylvain; Wahli, Walter

2009-01-01

272

Differentiation of endogenous and exogenous steroids by gas chromatography-combustion-mass spectrometry isotope ratio  

International Nuclear Information System (INIS)

Urinary steroids profiles are used to control the misuse of endogenous steroids such as testosterone and dihydrotestosterone. The testosterone/epistestosterone ratio, measured by Gas Chromatography-Mass Spectrometry, is used to control testosterone administration. When T/E ratio is higher than 4, consumption of testosterone or its precursors is suspected. Recent researches have demonstrated the effectiveness of Carbon Isotope Ratio Mass Spectrometry to detect and confirm endogenous steroids administration. The ratio of the two stable carbon isotopes 13C and 12C allows the differentiation of natural and synthetic steroids because synthetic steroids have lower 13C abundance. In fact, the carbon isotope ratios can be used to determine endogenous steroids administration even when testosterone/epistestosterone ratio is at its normal value. In the current work, some of the most important aspects related to differentiation of endogenous and exogenous steroids by means of Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry are discussed. Also, this article provides a review about the purification and sample preparation previous to the analysis, and diet effects on carbon isotope ratio of endogenous anabolics steroids is presented too

273

Use of radioimmunoassay procedures for the determination of sex hormones in animal tissues  

Energy Technology Data Exchange (ETDEWEB)

Radioimmunoassay methods for the determination of sex steroids and other compounds with sex hormone-like activities in various edible animal tissues and endocrine glands have been developed. Reliability of these methods, allowing quantification in a range of 10/sup -11/ M, has been adequately demonstrated. When applied to monitoring residues of anabolic sex hormones in edible tissues of veal calves, physiological baseline levels of some endogenous ''anabolic'' steroids (like testosterone, oestrogens) were established; in the case of xenobiotics residues at the scheduled time of slaughter could be quantified (trenbolone) and a regulatory method to implement the ban of diethylstilbestrol was introduced.

Hoffmann, B. (Institut fuer Veterinaermedizin des Bundesgesundheitsamtes (Robert von Ostertag-Institut), Berlin (Germany, F.R.))

1983-07-01

274

Endocrine correlates of musth in free-ranging Asian elephants (Elephas maximus) determined by non-invasive faecal steroid hormone metabolite measurements.  

Science.gov (United States)

The occurrence of musth, a period of elevated levels of androgens and heightened sexual activity, has been well documented for the male Asian elephant (Elephas maximus). However, the relationship between androgen-dependent musth and adrenocortical function in this species is unclear. The current study is the first assessment of testicular and adrenocortical function in free-ranging male Asian elephants by measuring levels of testosterone (androgen) and cortisol (glucocorticoid--a physiological indicator of stress) metabolites in faeces. During musth, males expectedly showed significant elevation in faecal testosterone metabolite levels. Interestingly, glucocorticoid metabolite concentrations remained unchanged between musth and non-musth periods. This observation is contrary to that observed with wild and captive African elephant bulls and captive Asian bull elephants. Our results show that musth may not necessarily represent a stressful condition in free-ranging male Asian elephants. PMID:24358371

Ghosal, Ratna; Ganswindt, André; Seshagiri, Polani B; Sukumar, Raman

2013-01-01

275

Steroidal saponins from Asparagus acutifolius.  

Science.gov (United States)

Six new steroidal saponins (1-6) were isolated from the roots of A. acutifolius L., together with a known spirostanol glycoside (7). Their structures were elucidated mainly by extensive spectroscopic analysis (1D and 2D NMR, FABMS and HRESIMS). Compounds 4-7 demonstrated antifungal activity against the human pathogenic yeasts C. albicans, C. glabrata and C. tropicalis with MICs values between 12.5 and 100 microg/ml. PMID:17449075

Sautour, Marc; Miyamoto, Tomofumi; Lacaille-Dubois, Marie-Aleth

2007-10-01

276

Perioperative Stress-Dose Steroids  

OpenAIRE

Supraphysiologic corticosteroid doses have routinely been considered the perioperative standard of care over the past six decades for patients on long-term steroid therapy. However, the accumulation of data over this period is beginning to suggest that such a practice may not be necessary. The majority of these studies are retrospective reviews or small prospective cohorts, but there are two small prospective, randomized placebo-controlled trials, one prospective primate trial, and several sy...

Kelly, Kristin N.; Domajnko, Bastian

2013-01-01

277

Rats with steroid-induced polycystic ovaries develop hypertension and increased sympathetic nervous system activity  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Polycystic ovary syndrome (PCOS is a complex endocrine and metabolic disorder associated with ovulatory dysfunction, abdominal obesity, hyperandrogenism, hypertension, and insulin resistance. Methods Our objectives in this study were (1 to estimate sympathetic-adrenal medullary (SAM activity by measuring mean systolic blood pressure (MSAP in rats with estradiol valerate (EV-induced PCO; (2 to estimate alpha1a and alpha2a adrenoceptor expression in a brain area thought to mediate central effects on MSAP regulation and in the adrenal medulla; (3 to assess hypothalamic-pituitary-adrenal (HPA axis regulation by measuring adrenocorticotropic hormone (ACTH and corticosterone (CORT levels in response to novel-environment stress; and (4 to measure abdominal obesity, sex steroids, and insulin sensitivity. Results The PCO rats had significantly higher MSAP than controls, higher levels of alpha1a adrenoceptor mRNA in the hypothalamic paraventricular nucleus (PVN, and lower levels of alpha2a adrenoceptor mRNA in the PVN and adrenal medulla. After exposure to stress, PCO rats had higher ACTH and CORT levels. Plasma testosterone concentrations were lower in PCO rats, and no differences in insulin sensitivity or in the weight of intraabdominal fat depots were found. Conclusion Thus, rats with EV-induced PCO develop hypertension and increased sympathetic and HPA-axis activity without reduced insulin sensitivity, obesity, or hyperandrogenism. These findings may have implications for mechanisms underlying hypertension in PCOS.

Ploj Karolina

2005-09-01

278

Mechanisms of pain modulation by sex hormones in migraine.  

Science.gov (United States)

A number of pain conditions, acute as well as chronic, are much more prevalent in women, such as temporomandibular disorder (TMD), irritable bowel syndrome, fibromyalgia, and migraine. The association of female sex steroids with these nociceptive conditions is well known, but the mechanisms of their effects on pain signaling are yet to be deciphered. We reviewed the mechanisms through which female sex steroids might influence the trigeminal nociceptive pathways with a focus on migraine. Sex steroid receptors are located in trigeminal circuits, providing the molecular substrate for direct effects. In addition to classical genomic effects, sex steroids exert rapid nongenomic actions to modulate nociceptive signaling. Although there are only a handful of studies that have directly addressed the effect of sex hormones in animal models of migraine, the putative mechanisms can be extrapolated from observations in animal models of other trigeminal pain disorders, like TMD. Sex hormones may regulate sensitization of trigeminal neurons by modulating expression of nociceptive mediator such as calcitonin gene-related peptide. Its expression is mostly positively regulated by estrogen, although a few studies also report an inverse relationship. Serotonin (5-Hydroxytryptamine [5-HT]) is a neurotransmitter implicated in migraine; its synthesis is enhanced in most parts of brain by estrogen, which increases expression of the rate-limiting enzyme tryptophan hydroxylase and decreases expression of the serotonin re-uptake transporter. Downstream signaling, including extracellular signal-regulated kinase activation, calcium-dependent mechanisms, and cAMP response element-binding activation, are thought to be the major signaling events affected by sex hormones. These findings need to be confirmed in migraine-specific animal models that may also provide clues to additional ion channels, neuropeptides, and intracellular signaling cascades that contribute to the increased prevalence of migraine in women. PMID:21631476

Gupta, Saurabh; McCarson, Kenneth E; Welch, K M A; Berman, Nancy E J

2011-06-01

279

Environmentally relevant concentrations of benzo[a]pyrene affect steroid levels and affect gonad of male scallop Chlamys farreri.  

Science.gov (United States)

Sexually mature male Chlamys farreri were exposed to benzo[a]pyrene for 10 days at four concentrations at 0, 0.025, 0.5 and 10?g/L. Fluctuations in sex steroids during the exposure period were observed, which indicated that sex steroids have a role in gamete development. Exposure to B[a]P altered levels of 17?-estradiol, testosterone, and progesterone. Furthermore, B[a]P treatments induced oxidative stress in a dose-dependent manner on spermary of scallop and led to delayed development and damaged spermatid in germinal epithelium of spermary. Overall, B[a]P affected the steroid levels and induced gonadal toxicity at environmentally relevant concentrations. PMID:25637750

Tian, Shuangmei; Pan, Luqing; Tao, Yanxia; Sun, Xiaohua

2015-04-01

280

Endothelial function in male body builders taking anabolic androgenic steroids  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Adverse cardiovascular events have been reported in body builders taking anabolic steroids. Adverse effects of AAS on endothelial function can initiate atherosclerosis. This study evaluates endothelial function in body builders using AAS, compared with non-steroids using athletes as controls. Methods: We recruited 30 nonsmoking male body builders taking AAS, 14 in build up phase, 8 in work out phase, and 8 in post steroid phase, and 30 nonsmoking male athletes who denied ever using steroids. Serum lipids and fasting plasma glucose were measured to exclude dyslipidemia and diabetes. Brachial artery diameter was measured by ultrasound at rest, after cuff inflation, and after sublingual glyceriltrinitrate (GTN to determine flow mediated dilation (FMD, nitro mediated dilation (NMD and ratio of FMD to NMD (index of endothelial function. Result: Use of AAS was associated with higher body mass index (BMI and low density lipoprotein–cholesterol (LDL-C. Mean ratio of flow mediated dilatation after cuff deflation to post GTN dilatation of brachial artery (index of endothelial function in body builders taking AAS was significantly lower than control group (0.96(0.05 versus 1(0.08; p=0.03. After adjusting BMI, age and weight, no significant difference was seen in index of endothelial function between two groups (p=0 .21. Conclusion: Our study indicates that taking AAS in body builders doesn’t have direct effect on endothelial function. Future study with bigger sample size and measurement of AAS metabolites is recommended. Key words: endothelium, lipids, anabolic steroids, body builders

H Hashemi

2005-11-01

281

Use of AUDIT, and measures of drinking frequency and patterns to detect associations between alcohol and sexual behaviour in male sex workers in Kenya  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Previous research has linked alcohol use with an increased number of sexual partners, inconsistent condom use and a raised incidence of sexually transmitted infections (STIs. However, alcohol measures have been poorly standardised, with many ill-suited to eliciting, with adequate precision, the relationship between alcohol use and sexual risk behaviour. This study investigates which alcohol indicator - single-item measures of frequency and patterns of drinking ( > = 6 drinks on 1 occasion, or the Alcohol Use Disorders Identification Test (AUDIT - can detect associations between alcohol use and unsafe sexual behaviour among male sex workers. Methods A cross-sectional survey in 2008 recruited male sex workers who sell sex to men from 65 venues in Mombasa district, Kenya, similar to a 2006 survey. Information was collected on socio-demographics, substance use, sexual behaviour, violence and STI symptoms. Multivariate models examined associations between the three measures of alcohol use and condom use, sexual violence, and penile or anal discharge. Results The 442 participants reported a median 2 clients/week (IQR = 1-3, with half using condoms consistently in the last 30 days. Of the approximately 70% of men who drink alcohol, half (50.5% drink two or more times a week. Binge drinking was common (38.9%. As defined by AUDIT, 35% of participants who drink had hazardous drinking, 15% harmful drinking and 21% alcohol dependence. Compared with abstinence, alcohol dependence was associated with inconsistent condom use (AOR = 2.5, 95%CI = 1.3-4.6, penile or anal discharge (AOR = 1.9, 95%CI = 1.0-3.8, and two-fold higher odds of sexual violence (AOR = 2.0, 95%CI = 0.9-4.9. Frequent drinking was associated with inconsistent condom use (AOR = 1.8, 95%CI = 1.1-3.0 and partner number, while binge drinking was only linked with inconsistent condom use (AOR = 1.6, 95%CI = 1.0-2.5. Conclusions Male sex workers have high levels of hazardous and harmful drinking, and require alcohol-reduction interventions. Compared with indicators of drinking frequency or pattern, the AUDIT measure has stronger associations with inconsistent condom use, STI symptoms and sexual violence. Increased use of the AUDIT tool in future studies may assist in delineating with greater precision the explanatory mechanisms which link alcohol use, drinking contexts, sexual behaviours and HIV transmission.

Temmerman Marleen

2011-05-01

282

Vibrational properties and phonon anharmonicity in ZnS1?xSex: Inelastic neutron scattering, Raman scattering, X-ray diffraction measurements and lattice dynamical studies  

International Nuclear Information System (INIS)

Inelastic neutron scattering, Raman and X-ray diffraction measurements coupled with lattice dynamical calculations (employing a semi-empirical transferable potential model) have been carried out to gain a detailed understanding of the peculiar vibrational spectrum exhibited by the mixed crystal ZnS1?xSex. Raman scattering measurements performed over a varying range of temperature (100–800 K) and pressure (up to 13 GPa) have confirmed that the additional mode observed in the spectra are visible over the entire range of temperature and pressure. Correlation of the individual motions of atoms (obtained from computed total and partial phonon density of states) with the inelastic neutron scattering measurements (carried out over the entire Brillouin zone) have then indicated that the existence of the additional mode in ZnS1?xSex is due to the vibrations of the Se atom being in resonance with that of the S atom. Further, it has been shown that the presence of this additional mode can be tuned by varying the mass of the atom at the Se site. In addition, an analysis of bond-length distribution with increasing Se concentration have elucidated that bond-length spread is not responsible for the presence of the additional mode. An analysis of the peak shifts of the Raman modes with temperature and pressure indicate that the anharmonicity of the vibrational modes increases with increasing compositional disorder. This is attributed to the fact that increasing Se concentration gives rise to a distribution of bond-lengths in ZnS1?xSex, which is responsible for this compositional disorder induced anharmonicity. Our computations have thus revealed that mass of the anion is responsible for the presence of additional mode while bond-length distribution gives rise to the existence of compositional disorder induced anharmonicity in ZnS1?xSex. Further, it is observed that the contribution of explicit anharmonicity to the total anharmonicity becomes dominant at higher temperatures. This compound also exhibits negative thermal expansion at low temperatures as obtained from our X-ray diffraction measurements as a function of temperature (10–800 K)

283

PLANT SCIENCES: Plant Genes on Steroids  

Science.gov (United States)

Access to the article is free, however registration and sign-in are required. Plants, like animals, use steroid hormones to regulate their development. However, in plants, the steroid hormone is bound by a receptor at the cell surface instead of a nuclear receptor. In a Perspective, Sablowski and Harberd discuss studies published here (He et al.) and elsewhere that provide the missing link between binding of the steroid by its receptor and changes in the expression of target genes.

Robert Sablowski (John Innes Centre; Department of Cell and Developmental Biology)

2005-03-11

284

Azoospermi hos to bodybuildere efter anaboliske steroider  

DEFF Research Database (Denmark)

During investigations for infertility azoospermia was diagnosed in two men who were concomitantly using anabolic steroids for body-building. Following cessation of anabolic steroid use the semen quality was normalized. Suppression of spermatogenesis during treatment with testosterone and derivatives hereof is wellknown. Usage of anabolic steroids should be remembered as a cause of oligo- and azoospermia and asked about in cases of sperm counts approaching or at zero.

SØrensen, M B; Ingerslev, Hans Jakob

1995-01-01

285

Measurements of the frontal and prefrontal lobe volumes by three dimensional magnetic resonance imaging scan. III. Analysis of sex differences with advanced age  

International Nuclear Information System (INIS)

To determine whether there is sex difference in the growth of the frontal and prefrontal lobes, we quantitatively measured the volume of these lobes by three dimensional (3-D) MRI in healthy 12 males (5 months to 39 years) and six females (1 year 11 months to 27 years). The left and right lobes were studied separately. The 3-D MRI data were acquired by the fast spoiled gradient recalled (SPGR) sequence using a 1.5 T MR imager. The frontal and prefrontal lobe volumes were measured by the volume measurement function of the Workstation. In males, the left to right ratio (L/R ratio) of the frontal and prefrontal lobes increased with age. On the contrary, in females, L/R ratio of the frontal and prefrontal lobes showed no significant change with advancing age. These results highlighted sex-specific maturational changes of the frontal and prefrontal lobes and suggested that quantitative data on the frontal and prefrontal lobe are important in interpreting brain abnormalities in children with developmental disorders. (author)

286

46,XY disorder of sex development in a sudanese patient caused by a novel mutation in the HSD17B3 gene.  

Science.gov (United States)

In this study, we present a Sudanese 46,XY patient raised as a female and diagnosed at the age of 20 years with having 17?-hydroxysteroid dehydrogenase type 3 (17?-HSD3) deficiency. She presented with primary amenorrhea, undeveloped breasts and a male pattern of secondary sexual characteristics. Examination of her external genitalia showed type IV genital circumcision. Steroid measurements both in urine and serum pointed to 17?-HSD3 deficiency. A novel homozygous splice-site mutation [c.524 + 2T>A] was detected in intron 7 of the HSD17B3 gene. In this patient, steroid concentration clearly supported both the clinical diagnosis of 17?-HSD3 deficiency and the functional relevance of the mutation. Interestingly, despite of the type IV genital circumcision, the patient expressed her interest in reassigning her sex from female to male. PMID:24941935

Ellaithi, Mona; Werner, Ralf; Riepe, Felix G; Krone, Nils; Kulle, Alexandra E; Diab, Tayseer; Kamel, Alaa K; Arlt, Wiebke; Holterhus, Paul-Martin; Sabir, Omyma; Hiort, Olaf

2014-01-01

287

Estimación del sexo en cazadores-recolectores de Sudamérica a partir de variables métricas del húmero Sex estimation of South american hunter-gatherers using humeral measurements  

Directory of Open Access Journals (Sweden)

Full Text Available El objetivo de este trabajo es desarrollar funciones discriminantes para estimar el sexo en poblaciones cazadoras recolectoras sudamericanas a partir de variables métricas del húmero. Se seleccionaron tres muestras de poblaciones del Holoceno tardío procedentes de: a Sur de Patagonia (n= 64, b Noreste de Patagonia (n= 47, y c Noreste de Pampa y Entre Ríos (n= 35. Para obtener una estimación confiable del sexo se incluyeron individuos con estructuras diagnósticas presentes de la pelvis o el cráneo. Se analizaron seis variables del húmero que fueron empleadas para generar funciones discriminantes a través del método stepwise forward. El sexo estimado fue contrastado con el sexo basado en la pelvis a fin de establecer su exactitud. Las asignaciones correctas calculadas mediante el método de validación cruzada fueron relevadas en las tres muestras, que variaron entre el 82% y el 100%. A su vez, se estimó el sexo con funciones provenientes de otras poblaciones del mundo, que arrojaron porcentajes menores de asignaciones correctas. Por lo tanto, la técnica desarrollada proporciona estándares específicos para las poblaciones del cono sur de América y constituye una herramienta confiable para la estimación del sexo en muestras procedentes de las áreas analizadas.The purpose of this study is to develop discriminant functions for sex estimation in hunter-gatherer South American populations, using humerus metric variables. Three Late Holocene aboriginal population samples were selected from: a South Patagonia (n= 64, b Northeastern Patagonia (n= 47 and c Northeastern Pampa and Entre Ríos (n= 35. Only those individuals showing pelvic or cranial diagnostic structures were included, in order to obtain reliable and independent sex estimation. Six humeral variables were measured (Maximum Length, Epicondylar Breadth, Vertical Diameter of Head, Maximum and Minimum Diameter at Midshaft and Minimum Diaphyseal Circumference and discriminant functions were generated from them through stepwise forward method, which selected different combinations of these variables for each sample. In order to assess the accuracy of estimations, both pelvic and humeral sex results were compared. Cross-validation percentages of correct sex assignations were high, ranging between 82 and 100 percent. In turn, other functions were tested, generated from different populations worldwide, and results for the three samples showed mostly lower percentages. Therefore, it is concluded that Southern-South America population-specific standards were obtained through this method, allowing for reliable sex determination in samples from the studied areas.

Marien Béguelin

2011-07-01

288

Age-dependent role of steroids in the regulation of growth of the hen follicular wall  

OpenAIRE

Abstract Background The ovaries are the primary targets of senescence effects in mammalian and avian species. In the present study, relationships between reproductive aging, sex steroids and the growth pattern of the pre-ovulatory follicle wall were investigated using young hens with long clutch (YLC), old hens with long clutch (OLC), old hens with short clutch (OSC), and old hens with interrupted long clutch (OILC). Methods Experiment 1: Hens were sacrificed 1.5 and 14.5 h after ovulation. E...

Lebedev Vladimir A; Lebedeva Irina Y; Grossmann Roland; Parvizi Nahid

2010-01-01

289

Ketoconazole inhibition of testicular secretion of testosterone and displacement of steroid hormones from serum transport proteins.  

OpenAIRE

In vivo perfusion of canine testes with ketoconazole inhibited the stimulation of testosterone production by human chorionic gonadotropin in a dose-dependent manner. Ketoconazole also selectively displaced steroids from serum-binding globulins. Dihydrotestosterone and estradiol binding to sex hormone-binding globulin were inhibited by ketoconazole. Cortisol binding to corticosteroid-binding globulin was unaffected. The concentrations of ketoconazole that inhibited human chorionic gonadotropin...

Grosso, D. S.; Boyden, T. W.; Pamenter, R. W.; Johnson, D. G.; Stevens, D. A.; Galgiani, J. N.

1983-01-01

290

Into the world of steroids: A biochemical “keep in touch” in plants and animals  

OpenAIRE

Evolution of steroids such as sex hormones and ecdysteroids occurred independently in the animal and plant kingdoms. Plants use phytoecdysteroids (PEs) to control defense interactions with some predators; furthermore, PEs can exert beneficial influence on many aspects of mammalian metabolism. Endocrine disrupting compounds such as the estrogen agonist bisphenol A (BPA) are widespread in the environment, posing a potential hormonal risk to animals and plants. Adverse BPA effects on reproductiv...

Speranza, Anna

2010-01-01

291

Steroidal glycosides from Hoodia gordonii.  

Science.gov (United States)

Ten new C21-steroidal derivatives, namely gordonosides A-L (1-10) were isolated from a chloroform extract of the aerial parts of Hoodia gordonii, a plant widely used in the nutraceutical market as an ingredient of weight loss supplements. Compounds (2-10) are based on 3beta,14beta-dihydroxy-pregn-5-en-17-betaone aglycone (1). Their structures were characterized on the basis of HR-MS spectrometry and both 1D and 2D NMR techniques. PMID:17485103

Dall'Acqua, Stefano; Innocenti, Gabbriella

2007-06-01

292

Steroid dynamics in the rabbit  

International Nuclear Information System (INIS)

Male rabbits were infused at a constant rate with 3H-androstenedione/14C-estrone (n . 5) or 3H-testosterone/14C-estradiol-17 beta (n . 3) for 3 1/2 hr and blood samples were obtained over the last hour and analyzed for radioactivity as androstenedione (A), testosterone (T), estrone (E1), estradiol-17 beta (E2 beta) and estradiol-17 alpha (E2 alpha). The mean value for the metabolic clearance rate of androstenedione (MCRA) was 85 +/- 10 l/day/kg, which was significantly greater than the mean MCRE1 59 +/- 10 l/day/kg. MCRT, 42 +/- 8 l/day/kg, and MCRE2 beta, 45 +/- 9 l/day/kg were not different. The conversion ratio of androstenedione to testosterone (CRA,T) was greater than CRT,A but for the estrogens, CRE2 beta, E1 was greater than CRE1,E2 beta. CRE2 beta, E2 alpha was greater than CRE1,E2 alpha. The overall aromatization of androstenedione to estrone, the fraction of 3H-androstenedione infused into the blood and measured as 3H-estrone in blood [( rho]A,E1BB) was 0.0005 +/- 0.0001 and for [rho]T,E2 beta BB was 0.0012 +/- 0.0006. In the rabbit both sex hormone binding globulin (SHBG) and albumin binding may effect the MCRs, and peripheral aromatization of androgens occurs to a far lesser degree than in humans and primates

293

Sex during Pregnancy  

Science.gov (United States)

... satisfying and safe sexual relationship during pregnancy. Is Sex During Pregnancy Safe? Sex is considered safe during ... frequently asked questions about sex during pregnancy. Can sex harm my baby? No. Your baby is fully ...

294

Steroids  

Science.gov (United States)

... favorite sport, not to mention earning a big salary. But in recent years, people have been looking ... or fear (paranoia) problems sleeping nausea vomiting trembling high blood pressure that can damage the heart or ...

295

Cyanobacterial Bioamarkers: Triterpenoids plus Steroids?  

Science.gov (United States)

Reconstructing the biomarker record of the early Earth requires us to make assumptions about the constancy and specificity of lipid biosynthetic pathways through geological time and rests upon our knowledge of the lipid composition of extant organisms.\\x90\\x90 For example, the three domains of extant life Eukarya, Archaea and Bacteria were present in Archean ecosystems if we are to believe the record of chemical fossils that have been found in rocks as old as 2700Ma.\\x90 However, the validity of the steroid signature as an indicator for Eukarya has questioned because of some reports of Ophytosterol, biosynthesis in cyanobacteria and we examined this issue in some new experiments with cyanobacteria grown in culture.\\x90 After initial cultures of Phormidium and Chlorogloeopsis proved to contain sterols, in addition to the expected complement of hopanoid and 2-methylhopanoid, we hypothesized that these might be the result of fungal contamination.\\x90 Subsequent cultures grown after repeated sub-culturing in the presence of cycloheximide proved to be devoid of sterol. Our results are therefore consistent with the notion that sterol biosynthesis is, with very few exceptions, a primary characteristic of Eukarya.\\x90 Consequently, the steroid hydrocarbons that are found in ancient sediments are most likely the remains of algae and other eukaryotes.\\x90

Summons, R. E.; Jahnke, L. L.; Cullings, K. W.; Logan, G. A.

2001-12-01

296

Relative potencies and combination effects of steroidal estrogens in fish.  

Science.gov (United States)

The natural steroids estradiol-17beta (E2) and estrone (E1) and the synthetic steroid ethynylestradiol-17alpha (EE2) have frequently been measured in waters receiving domestic effluents. All of these steroids bind to the estrogen receptor(s) and have been shown to elicit a range of estrogenic responses in fish at environmentally relevant concentrations. At present, however, no relative potency estimates have been derived for either the individual steroidal estrogens or their mixtures in vivo. In this study the estrogenic activity of E2, E1, and EE2, and the combination effects of a mixture of E2 and EE2 (equi-potent fixed-ratio mixture), were assessed using vitellogenin induction in a 14-day in vivo juvenile rainbow trout screening assay. Median effective concentrations, relative to E2, for induction of vitellogenin were determined from the concentration-response curves and the relative estrogenic potencies of each of the test chemicals calculated. Median effective concentrations were between 19 and 26 ng L(-1) for E2, 60 ng L(-1) for E1, and between 0.95 and 1.8 ng L(-1) for EE2, implying that EE2 was approximately 11 to 27 times more potent than E2, while E2 was 2.3 to 3.2 times more potent than E1. The median effective concentration, relative to E2, for the binary mixture of E2 and EE2 was 15 ng L(-1) (comprising 14.4 ng L(-1) E2 and 0.6 ng L(-1) EE2). Using the model of concentration addition it was shown that this activity of the binary mixture could be predicted from the activity of the individual chemicals. The ability of each individual steroid to contribute to the overall effect of a mixture, even at individual no-effect concentrations, combined with the high estrogenic potency of the steroids, particularly the synthetic steroid EE2, emphasizes the need to consider the total estrogenic load of these chemicals in our waterways. PMID:12680667

Thorpe, Karen L; Cummings, Rob I; Hutchinson, Thomas H; Scholze, Martin; Brighty, Geoff; Sumpter, John P; Tyler, Charles R

2003-03-15

297

About Steroids (Inhaled and Oral Corticosteroids)  

Science.gov (United States)

... make steroids? Corticosteroids are similar to cortisol, a hormone produced by the adrenal glands in the body. Cortisol is one of the body's own natural steroids. Cortisol is essential for life and well being. During stress, our bodies produce extra cortisol to keep us ...

298

Steroids: To Test or to Educate?  

Science.gov (United States)

In February 2005, The Dallas Morning News published a multipart series on steroid use among high school students in Texas. The paper's four-month investigation was wide-ranging, but shined a particular spotlight upon alleged abuses in the 13,700-student Grapevine-Colleyville Independent School District, north of Dallas. Use of steroids and other…

LaFee, Scott

2006-01-01

299

Steroids Update, Part 1 and Part 2.  

Science.gov (United States)

Part 1 of this two-part article describes the views of a physician who believes that athletes who want to take steroids are best protected by receiving a prescription and monitoring. Part 2 discusses the more general view of physicians that steroids should not be prescribed but perhaps should be monitored. (MT)

Miller, Calvin; Duda, Marty

1986-01-01

300

Osteonecrosis following alcohol, cocaine, and steroid use.  

LENUS (Irish Health Repository)

Alcohol, steroids and cocaine have all been shown to be independent risk factors for osteonecrosis when taken in excess. Here we present a case of a young girl who developed debilitating osteonecrosis secondary to low doses of alcohol, steroids and cocaine. We feel it is important to highlight to those caring for such patients of the potential devastating complication of these three agents.

Ziraldo, Laura

2012-02-01

301

Behavioural manifestations of anabolic steroid use.  

Science.gov (United States)

The use of anabolic androgenic steroids (AAS) for gains in strength and muscle mass is relatively common among certain subpopulations, including athletes, bodybuilders, adolescents and young adults. Adverse physical effects associated with steroid abuse are well documented, but more recently, increased attention has been given to the adverse psychiatric effects of these compounds. Steroids may be used in oral, 17alpha-alkylated, or intramuscular, 17beta-esterified, preparations. Commonly, steroid users employ these agents at levels 10- to 100-fold in excess of therapeutic doses and use multiple steroids simultaneously, a practice known as 'stacking'. Significant psychiatric symptoms including aggression and violence, mania, and less frequently psychosis and suicide have been associated with steroid abuse. Long-term steroid abusers may develop symptoms of dependence and withdrawal on discontinuation of AAS. Treatment of AAS abusers should address both acute physical and behavioural symptoms as well as long-term abstinence and recovery. To date, limited information is available regarding specific pharmacological treatments for individuals recovering from steroid abuse. This paper reviews the published literature concerning the recognition and treatment of behavioural manifestations of AAS abuse. PMID:15984895

Trenton, Adam J; Currier, Glenn W

2005-01-01

302

Enhanced ovarian steroid secretion before implantation in early human pregnancy.  

Science.gov (United States)

Previous studies have compared ovarian steroid production in the luteal phase of nonconceptive and conceptive cycles. Some investigators reported higher preimplantational levels of progesterone in conceptive cycles vs. nonconceptive cycles, but other studies have found no differences. Many of these results were difficult to interpret because the studies included infertile women and/or women who received exogenous hormones. In this study we have characterized the profiles of gonadotropin secretion and ovarian steroid response during early pregnancy in a population of spontaneously ovulating women and compared them to those in nonconceptive cycles of recently fertile women. Blood samples were collected daily during the luteal phase from 24 women during 51 cycles of artificial insemination with donor semen. Cycles were segregated to those from women who had a successful term pregnancy (normal group) and those having an early spontaneous abortion (SAB group) and were also classified as nonconceptive or conceptive based on measurements of hCG. Serum LH and FSH did not show marked differences between nonconceptive and conceptive cycles in the periimplantation period in either the normal or SAB group. In the normal group, estradiol concentrations were significantly higher in conceptive cycles than in nonconceptive cycles beginning 6 days after the LH peak and continuing through the end of the cycle, while differences in progesterone concentrations bordered on or exceeded significance during the same time period. In the SAB group, preimplantation differences in pituitary gonadotropin and ovarian steroid secretion were not observed, whereas the postimplantation hCG concentrations in the SAB group were significantly lower than those in the normal group. It is reasoned that embryos with defective post-implantation hCG secretion may have had this defect before detection of hCG in serum, thus accounting for the lack of stimulation of steroid secretion in these pregnancies. These findings suggest that the enhanced ovarian steroid secretion in conceptive cycles may be due to a gonadotropic stimulus from the preimplantation embryo. PMID:8501152

Stewart, D R; Overstreet, J W; Nakajima, S T; Lasley, B L

1993-06-01

303

Determinación del genero por medio de medidas y verificación del peso del hueso esternon (Brasil Sex determination by measures and weight verification of sternum bone.Brasil  

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Full Text Available La determinación del género humano (sexo es una de las principales atribuciones del odontólogo forense y del médico legista encargados del análisis antropológico de esqueletos, piezas y fragmentos óseos. Entre los huesos que pueden y deben ser analizados se encuentra el hueso esternón, considerando, principalmente, sus características particulares. En el presente estudio fueron medidos y pesados 100 huesos esternón, siendo 50 del género femenino y 50 del género masculino, provenientes de Cuiabá, Mato Grosso, Brasil, con edades comprendidas entre 19 y 103 años. Fue verificado que la medida del centro de la escotadura de inserción del primer arco costal derecho al izquierdo y el peso del manubrio y cuerpo del esternón, altamente significantes, constituyen parámetros para determinar el género. Fue obtenida, también, una fórmula matemática que posibilita determinar el género en análisis futuras con índices de acierto de 69,2%. (SEX DETERMINATION BY MEASURES AND WEIGHT VERIFICATION OF ESTERNUM BONEHuman gender determination is one of the main attributions of forensic odontologists and forensic pathologists responsible for the anthropological analysis of skeletons, parts and fragmented bones. One of the bones that can and must be analyzed is the sternum, considering its particular characteristics. In the present study we’ve measured and weighed 100 sternums, 50 belonging to female gender and 50 to male gender proceeding from Cuiabá-MT, with age varying between 19 and 103 years. It was verified that the measure of the center of the chamfer of the insertion of the first to the left costal arc and the weight of the manubrium and body of sternum, are highly significant, becoming parameters to determine the gender. A mathematical formula was also obtained that permitted to determine the gender in future analyses with indices of 69,2%. (SEX DETERMINATION BY MEASURES AND WEIGHT VERIFICATION OF ESTERNUM BONE

Antonio Queiroz

2005-03-01

304

EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES  

Science.gov (United States)

Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

305

Stress and Sex Versus Immunity and Inflammation  

Science.gov (United States)

Glucocorticoids, the major effector hormones of the stress system, influence almost all aspects of mammalian physiology. These steroids exert their effects on a large network of primary, secondary, and tertiary target genes, encompassing up to 20% of the expressed genome in a tissue. New evidence shows quantitative and qualitative gender-specific differences in the actions of glucocorticoids on the rat liver transcriptome, suggesting that the pervasive actions of these hormones are modulated by gender, both as an inherent property of the target tissues and as a result of exposure of these tissues to estrogens and possibly also androgens. Generally, albeit not always, female mammals have more robust behavioral and somatic responses to stress and more potent immune and inflammatory reactions than males—differences that are inherent, sex steroid–mediated, or both and possibly the evolutionary products of natural selection of female and male roles.

George P. Chrousos (University of Athens; Children's Hospital Aghia Sophia REV)

2010-10-12

306

Gonadal steroid hormones and the hypothalamo-pituitary-adrenal axis.  

Science.gov (United States)

The hypothalamo-pituitary-adrenal (HPA) axis represents a complex neuroendocrine feedback loop controlling the secretion of adrenal glucocorticoid hormones. Central to its function is the paraventricular nucleus of the hypothalamus (PVN) where neurons expressing corticotropin releasing factor reside. These HPA motor neurons are a primary site of integration leading to graded endocrine responses to physical and psychological stressors. An important regulatory factor that must be considered, prior to generating an appropriate response is the animal's reproductive status. Thus, PVN neurons express androgen and estrogen receptors and receive input from sites that also express these receptors. Consequently, changes in reproduction and gonadal steroid levels modulate the stress response and this underlies sex differences in HPA axis function. This review examines the make up of the HPA axis and hypothalamo-pituitary-gonadal (HPG) axis and the interactions between the two that should be considered when exploring normal and pathological responses to environmental stressors. PMID:24246855

Handa, Robert J; Weiser, Michael J

2014-04-01

307

Cytotoxic steroids from Polyporus umbellatus.  

Science.gov (United States)

The steroids ergone (1), (22E, 24R)-ergosta-7,22-dien-3?-ol (2), 5?,8?-epidioxy-(22E,24R) -ergosta-6,22-dien-3?-ol (3), ergosta-6,22-dien-3?,5?,6?-triol (4), and polyporusterone B (5) were isolated from Polyporus umbellatus by bioassay-guided approach. They showed potent anticancer activity against HepG2 cells. Ergone displayed remarkable anticancer activity against HepG2, Hep-2, and Hela cancer cells, of which HepG2 cells were the most sensitive. Furthermore, the cytotoxic effects of ergone on normal human cells (HUVEC) were smaller than on cancer cells. The results showed that ergone had more selective cytotoxic activity against cancer cells than against normal cells. PMID:20458671

Zhao, Ying-Yong; Chao, Xu; Zhang, Yongmin; Lin, Rui-Chao; Sun, Wen-Ji

2010-10-01

308

A rare occurrence of a malignant ovarian steroid cell tumor not otherwise specified: A case report and literature review  

OpenAIRE

Steroid cell tumors not otherwise specified (NOS) are a rare subgroup of sex cord-stromal tumors. The tumors can occur at any age, although the mean age of occurrence is 43 years old. The majority are benign, but have the capability of producing one or more steroids associated with virilization. The present study reports the case of a 29-year-old female who presented to the Second Xiangya Hospital suffering from lower back and leg pain that had persisted for five months. The patient had regul...

Li, Kai; Zhu, Fufan; Xiong, Jing; Liu, Fengying

2014-01-01

309

Testosterone content of developing eggs and sex reversal in the medaka (Oryzias latipes).  

Science.gov (United States)

To understand the effect of testosterone on sex differentiation, the quantities of testosterone (T) and estradiol-17beta (E2) in developing eggs of medaka (Oryzias latipes) were measured by radioimmunoassay, and the influence on sex differentiation of treating embryos with exogenous androgens was also examined. Endogenous T of eggs dispersed into the environmental water at spawning, and precipitously declined to a minimum level during incubation for 2 days post-fertilization (dpf). It did not significantly increase during development. The E2 content of fertilized eggs increased when eggs were incubated in medium containing exogenous T at the concentrations of 100 and 500 ng/ml, but not in low concentrations of 10 ng/ml or less. The presence of 500 ng/ml 17alpha-methyltestosterone (MT) in the incubation medium also induced an increase in the E2 content of embryos. Exposure of embryos to exogenous 1 ng/ml T that corresponded with the level of T in eggs shortly after fertilization was enough to induce sex reversal of genotypic females to functional males. The co-existence of T and aromatase inhibitor in incubation medium inhibited not only the T-induced increase in the embryonic E2 content, but also the estrogenic effect of T in causing the paradoxical sex reversal from genotypic males to phenotypic females. However, treatment of embryos with the non-aromatizable androgen, 17alpha-methyldihydrotestosterone, induced no detectable increase in the E2 content of embryos, but still brought about sex reversal of genotypic males into females. This contradictory result suggests that the conversion of androgens to E2 may not always be the cause for induction of paradoxical sex reversal by T treatment. Consequently, these results on sex reversal induced by treatment of embryos with exogenous androgens suggest that endogenous T of developing medaka embryos may not act as the natural andro-inducer, and that genotypic sex can be modified by exogenous sex steroids at early developmental stages long before gonadal differentiation in the medaka. PMID:16137690

Iwamatsu, Takashi; Kobayashi, Hirokuni; Sagegami, Reiko; Shuo, Takuya

2006-01-01

310

Inhaled steroid/tobacco smoke particle interactions: a new light on steroid resistance  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Inhaled steroid resistance is an obstacle to asthma control in asthmatic smokers. The reasons of this phenomenon are not yet entirely understood. Interaction of drug particles with environmental tobacco smoke (ETS could change the aerodynamic profile of the drug through the particle coagulation phenomenon. Aim of the present study was to examine whether steroid particles interact with smoke when delivered in the presence of ETS. Methods Beclomethasone-hydrofluoralkane (BDP-HFA pMDI particle profile was studied after a single actuation delivered in ambient air or in the presence of ETS in an experimental chamber using a light scattering Optical Particle Counter capable of measuring the concentrations of particle sized 0.3–1.0, 1.1–2.0, 2.1–3.0, 3.1–4.0, 4.1–5.0, and > 5.1 ?m in diameter with a sampling time of one second. The number of drug particles delivered after a single actuation was measured as the difference between total particle number after drug delivery and background particle number. Two groups of experiments were carried out at different ambient background particle concentrations. Two-tail Student's t-test was used for statistical analysis. Results When delivered in ambient air, over 90% of BDP-HFA particles were found in the 0.3–1.0 ?m size class, while particles sized 1.1–2.0 ?m and 2.1–3.0 represented less than 6.6% and 2.8% of total particles, respectively. However, when delivered in the presence of ETS, drug particle profile was modified, with an impressive decrease of 0.3–1.0 ?m particles, the most represented particles resulting those sized 1.1–2.0 ?m (over 66.6% of total particles, and 2.1–3.0 ?m particles accounting up to 31% of total particles. Conclusion Our data suggest that particle interaction between inhaled BDP-HFA pMDI and ETS takes place in the first few seconds after drug delivery, with a decrease in smaller particles and a concurrent increase of larger particles. The resulting changes in aerosol particle profile might modify regional drug deposition with potential detriment to drug efficacy, and represent a new element of steroid resistance in smokers. Although the present study does not provide any functional or clinical assessment, it might be useful to advise smokers and non smokers with obstructive lung disease such as asthma or COPD, to avoid to act inhaled drugs in the presence of ETS in order to obtain the best therapeutic effect.

Nicolini Gabriele

2009-06-01

311

Age- and sex-related bone uptake of Tc-99m-HDP measured by whole-body bone scanning  

International Nuclear Information System (INIS)

Aim of this study was to validate a recently introduced new and easy-to-perform method for quantifying bone uptake of Tc-99m-labelled diphosphonate in a routine clinical setting and to establish a normal data base for bone uptake depending on age and gender. Methods: In 49 women (14-79 years) and 47 men (6-89 years) with normal bone scans as well as in 49 women (33-81 years) and 37 men (27-88 years) with metastatic bone disease whole-body bone scans were acquired at 3 min and 3-4 hours p.i. to calculate bone uptake after correction for both urinary excretion and soft tissue retention. Results: Bone uptake values of various age-related subgroups showed no significant differences between men and women (p>0.05). Furthermore, no differences could be proven between age-matched subgroups of normals and patients with less than 10 metastatic bone lesions, while patients with wide-spread bone metastases revealed significantly increased uptake values. In both men and women highest bone uptake was obtained (p<0.05) in subjects younger than 20 years with active epiphyseal growth plates. In men, bone uptake slowly decreased with age up to 60 years and then showed a tendency towards increasing uptake values. In women, the mean uptake reached a minimum in the decade 20-29 years and then slowly increased with a positive linear correlation of age and uptake in subjects older than 55 years (r=0.57). Conclusion: Since the results proposed in this study are in good agreement with data frs study are in good agreement with data from literature, the new method used for quantification could be validated in a large number of patients. Furthermore, age- and sex-related normal bone uptake values of Tc-99m-HDP covering a wide range of age could be presented for this method as a basis for further studies on bone uptake. (orig.)

312

Screening for anabolic steroids in urine of forensic cases using fully automated solid phase extraction and LC-MS-MS.  

Science.gov (United States)

A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids. Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic steroids. Only seven different steroids including testosterone were found in the material, suggesting that only a small number of common steroids are likely to occur in a forensic context. The steroids were often in high concentrations (>100 ng/mL), and a combination of steroids and/or other drugs of abuse were seen in the majority of cases. The method presented serves as a fast and automated screening procedure, proving the suitability of LC-MS-MS for analyzing anabolic steroids. PMID:25104076

Andersen, David W; Linnet, Kristian

2014-01-01

313

Distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals in wild fish species from Dianchi Lake, China  

International Nuclear Information System (INIS)

The distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals (EDCs) were studied in various tissues of wild fish species from Dianchi Lake, China. In muscle tissue, 4-tert-octylphenol, 4-cumylphenol, 4-nonlyphenol and bisphenol A were detected in fish from each sampling site, with maximal concentrations of 4.6, 4.4, 18.9 and 83.5 ng/g dry weight (dw), respectively. Steroids (estrone, 17?-estradiol 17?-ethynylestradiol and estriol) were found at lower levels (<11.3 ng/g dw) and less frequently in muscle samples. The highest concentrations of steroids and phenols were found in liver, followed by those in gill and the lowest concentration was found in muscle. The field bioconcentration factors (BCFs) of phenols were calculated in fish species ranged from 18 to 97. Moreover, the measured tissue concentrations were utilized in order to estimate water concentration of steroids (4.4-18.0 ng/L). These results showed that steroidal and phenolic EDCs were likely ubiquitous contaminants in wild fish. - Highlights: ? We assess the occurrence of EDCs in wild fish from Dianchi Lake, China. ? We investigate the distribution of steroidal and phenolic EDCs in fish tissues. ? We estimate the bioaccumulation of wild fish to steroidal and phenolic EDCs. ? Steroidal and phenolic EDCs are likely ubiquitous contaminants in wild fish. - Contaminants of endocrine disrupting chemicals in wild fish.

314

Distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals in wild fish species from Dianchi Lake, China  

Energy Technology Data Exchange (ETDEWEB)

The distribution and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals (EDCs) were studied in various tissues of wild fish species from Dianchi Lake, China. In muscle tissue, 4-tert-octylphenol, 4-cumylphenol, 4-nonlyphenol and bisphenol A were detected in fish from each sampling site, with maximal concentrations of 4.6, 4.4, 18.9 and 83.5 ng/g dry weight (dw), respectively. Steroids (estrone, 17{beta}-estradiol 17{alpha}-ethynylestradiol and estriol) were found at lower levels (<11.3 ng/g dw) and less frequently in muscle samples. The highest concentrations of steroids and phenols were found in liver, followed by those in gill and the lowest concentration was found in muscle. The field bioconcentration factors (BCFs) of phenols were calculated in fish species ranged from 18 to 97. Moreover, the measured tissue concentrations were utilized in order to estimate water concentration of steroids (4.4-18.0 ng/L). These results showed that steroidal and phenolic EDCs were likely ubiquitous contaminants in wild fish. - Highlights: > We assess the occurrence of EDCs in wild fish from Dianchi Lake, China. > We investigate the distribution of steroidal and phenolic EDCs in fish tissues. > We estimate the bioaccumulation of wild fish to steroidal and phenolic EDCs. > Steroidal and phenolic EDCs are likely ubiquitous contaminants in wild fish. - Contaminants of endocrine disrupting chemicals in wild fish.

Liu Jingliang; Wang Renmin; Huang Bin; Lin Chan; Wang Yu [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Pan Xuejun, E-mail: xjpan@kmust.edu.cn [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China)

2011-10-15

315

Steroid-induced Kager's fat pad atrophy  

International Nuclear Information System (INIS)

We report a rare case of Kager's fat pad atrophy and fibrosis in a 60-year-old woman 1 year after a steroid injection for Achilles tendinopathy. There are few published reports of steroid-induced atrophy affecting deeper layers of fat tissue. To our knowledge, this case report is the first to illustrate its features using magnetic resonance imaging. A review of the scientific literature is also presented. (orig.)

316

Polyhydroxylated steroidal glycosides from Paris polyphylla.  

Science.gov (United States)

Three new steroidal saponins, parisyunnanosides G-I (1-3), one new C(21) steroidal glycoside, parisyunnanoside J (4), and three known compounds, padelaoside B (5), pinnatasterone (6), and 20-hydroxyecdyson (7), were isolated from the rhizomes of Paris polyphylla Smith var. yunnanensis. Compounds 1 and 3 have unique trisdesmoside structures that include a C-21 ?-d-galactopyranose moiety. All compounds were evaluated for their cytotoxicity against human CCRF leukemia cells. PMID:22663190

Kang, Li-Ping; Liu, Yi-Xun; Eichhorn, Tolga; Dapat, Else; Yu, He-shui; Zhao, Yang; Xiong, Cheng-Qi; Liu, Chao; Efferth, Thomas; Ma, Bai-Ping

2012-06-22

317

A computational model to predict rat ovarian steroid secretion from in vitro experiments with endocrine disruptors.  

Science.gov (United States)

A finely tuned balance between estrogens and androgens controls reproductive functions, and the last step of steroidogenesis plays a key role in maintaining that balance. Environmental toxicants are a serious health concern, and numerous studies have been devoted to studying the effects of endocrine disrupting chemicals (EDCs). The effects of EDCs on steroidogenic enzymes may influence steroid secretion and thus lead to reproductive toxicity. To predict hormonal balance disruption on the basis of data on aromatase activity and mRNA level modulation obtained in vitro on granulosa cells, we developed a mathematical model for the last gonadal steps of the sex steroid synthesis pathway. The model can simulate the ovarian synthesis and secretion of estrone, estradiol, androstenedione, and testosterone, and their response to endocrine disruption. The model is able to predict ovarian sex steroid concentrations under normal estrous cycle in female rat, and ovarian estradiol concentrations in adult female rats exposed to atrazine, bisphenol A, metabolites of methoxychlor or vinclozolin, and letrozole. PMID:23326527

Quignot, Nadia; Bois, Frédéric Y

2013-01-01

318

Sex and Arthritis  

Science.gov (United States)

... Pain Pregnancy and Rheumatic Disease Sex and Arthritis Sex and Arthritis PRINT Download PDF Description Sexuality is ... sensation Erectile dysfunction or impotence Begin overcoming barriers Sex is not simply about reaching rapid orgasm with ...

319

Sex-linked dominant  

Science.gov (United States)

Inheritance - sex-linked dominant; Genetics - sex-linked dominant; X-linked dominant; Y-linked dominant ... type of chromosome that is affected (autosomal or sex chromosome). It also depends on whether the trait ...

320

Mitochondrial benzodiazepine receptors regulate steroid biosynthesis  

International Nuclear Information System (INIS)

Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine binding sites were tested for their effects on a well-established steroidogenic model system, the Y-1 mouse adrenal tumor cell line. 4'-Chlorodiazepam, PK 11195, and PK 14067 stimulated steroid production by 2-fold in Y-1 cells, whereas diazepam, flunitrazepam, zolpidem, and PK 14068 displayed a lower (1.2- to 1.5-fold) maximal stimulation. In contrast, clonazepam and flumazenil did not stimulate steroid synthesis. The potencies of these compounds to inhibit 3H-labeled PK 11195 binding to peripheral-type benzodiazepine recognition sites correlated with their potencies to stimulate steroid production. Similar findings were observed in bovine and rat adrenocortical cell preparations. These results suggest that ligands of the peripheral-type benzodiazepine recognition site acting on this mitochondrial receptor can enhance steroid production. This action may contribute specificity to the pharmacological profile of drugs preferentially acting on the benzodiazepine recognition sacting on the benzodiazepine recognition site associated with the outer membrane of certain mitochondrial populations

321

Mitochondrial benzodiazepine receptors regulate steroid biosynthesis  

Energy Technology Data Exchange (ETDEWEB)

Recent observations on the steroid synthetic capability within the brain open the possibility that benzodiazepines may influence steroid synthesis in nervous tissue through interactions with peripheral-type benzodiazepine recognition sites, which are highly expressed in steroidogenic cells and associated with the outer mitochondrial membrane. To examine this possibility nine molecules that exhibit a greater than 10,000-fold difference in their affinities for peripheral-type benzodiazepine binding sites were tested for their effects on a well-established steroidogenic model system, the Y-1 mouse adrenal tumor cell line. 4{prime}-Chlorodiazepam, PK 11195, and PK 14067 stimulated steroid production by 2-fold in Y-1 cells, whereas diazepam, flunitrazepam, zolpidem, and PK 14068 displayed a lower (1.2- to 1.5-fold) maximal stimulation. In contrast, clonazepam and flumazenil did not stimulate steroid synthesis. The potencies of these compounds to inhibit {sup 3}H-labeled PK 11195 binding to peripheral-type benzodiazepine recognition sites correlated with their potencies to stimulate steroid production. Similar findings were observed in bovine and rat adrenocortical cell preparations. These results suggest that ligands of the peripheral-type benzodiazepine recognition site acting on this mitochondrial receptor can enhance steroid production. This action may contribute specificity to the pharmacological profile of drugs preferentially acting on the benzodiazepine recognition site associated with the outer membrane of certain mitochondrial populations.

Mukhin, A.G.; Papadopoulos, V.; Costa, E.; Krueger, K.E. (Georgetown Univ. School of Medicine, Washington, DC (USA))

1989-12-01

322

New steroid derivative with hypoglycemic activity.  

Science.gov (United States)

Data indicates that some steroid derivatives may induce changes on glucose levels; nevertheless, data are very confusing. Therefore, more pharmacological data are needed to characterize the activity induced by the steroid derivatives on glucose levels. The aim of this study was to synthesize a new steroid derivative for evaluate its hypoglycemic activity. The effects of steroid derivative on glucose concentration were evaluated in a diabetic animal model using glibenclamide and metformin as controls. In addition, the pregnenolone-dihydrotestosterone conjugate was bound to Tc-99m using radioimmunoassay methods, to evaluate the pharmacokinetics of the steroid derivative over time. The results showed that the pregnenolone-dihydrotestosterone conjugate induces changes on the glucose levels in similar form than glibenclamide. Other data showed that the biodistribution of Tc-99m-steroid derivativein brain was higher in comparison with spleen, stomach, intestine liver and kidney. In conclusion, the pregnenolone-dihydrotestosterone conjugate exerts hypoglycemic activity and this phenomenon could depend of its physicochemical properties which could be related to the degree of lipophilicity of the steroidderivative. PMID:25550906

Lauro, Figueroa-Valverde; Francisco, Díaz-Cedillo; Lenin, Hau-Heredia; Elodia, García-Cervera; Eduardo, Pool-Gómez; Marcela, Rosas-Nexticapa; Bety, Sarabia-Alcocer

2014-01-01

323

Aerosol steroids for the treatment of peristomal mucocutaneous breakdown due to severe eczema  

OpenAIRE

•First line treatment for localised peristomal eczema is topical steroids.•Oil based topical steroids are associated with reduced bag adherence.•Alcohol based topical steroids are poorly tolerated due to pain.•Aerosol steroids are well tolerated.•Aerosol steroids do not impact on stoma bag adherence.•Aerosol steroids have fewer side effects in comparison to systemic steroids.

Nicholson, J.; Sriskandarajah, S.; Moore, J.; Clouston, H.; Telford, K.

2014-01-01

324

Free and sulfated steroids secretion in postpubertal boars (Sus scrofa domestica).  

Science.gov (United States)

Sulfated steroids have been traditionally regarded as inactive metabolites. However, they may also serve as precursors for the production of active free steroids in target cells. In this study, we used the boar as a model to study the metabolism, transport, and function of steroid sulfates due to their high production in the porcine testicular-epididymal compartment, of which the role is unknown. To characterize the secretion of free and sulfated steroids, plasma samples were collected from six postpubertal boars over 6 ?h every 20 ?min from the jugular vein. Long-term secretion profiles were also established in seven boars stimulated with human chorionic gonadotropin. To directly characterize the testicular output, samples were collected from superficial testicular arterial and venous blood vessels. Testosterone, androstenedione and sulfated pregnenolone, DHEA, estrone (E1), and estradiol-17? (E2) were determined by liquid chromatography-tandem mass spectrometry. Free E1 and E2 were measured by RIA. Irrespective of a high variability between individuals, the results suggest that i) all steroids assessed are primarily produced in the testis, ii) they exhibit similar profiles pointing to a pulsatile secretion with low frequency (three to five pulses per day), and iii) after synthesis at least a major proportion is immediately released into peripheral circulation. The fact that all steroid sulfates assessed are original testicular products and their high correlations with one another suggest their role as being intermediates of testicular steroidogenesis rather than as being inactivated end products. Moreover, a substantial use of sulfated steroids in porcine testicular steroidogenesis would assign a crucial regulatory role to steroid sulfatase, which is highly expressed in Leydig cells. PMID:24961601

Schuler, G; Dezhkam, Y; Bingsohn, L; Hoffmann, B; Failing, K; Galuska, C E; Hartmann, M F; Sánchez-Guijo, A; Wudy, S A

2014-09-01

325

In vitro binding of steroid hormones by natural and purified fibers  

International Nuclear Information System (INIS)

The in vitro binding of estrone, estradiol-17?, estriol, testosterone, dihydrotestosterone, and estrone-3-glucuronide by wheat, oat and corn brans, oat hulls, cellulose, lignin, and cholestyramine resin was measured. Steroid binding was carried out by mixing 50 mg of binding substance with varying substrate quantities (0.037 ?Ci; 0.50-2.51 pmol/incubation) of 3H-estrone, 3H-estradiol-17?, 3H-estriol, 3H-estrone-3-glucuronide, 4H-testosterone, and 370C for 1 hr with shaking. Following centrifugation of the reaction mixture, a 1 ml aliquot was analyzed for radioactivity. The extent of steroid sequestration was characteristic and reproducible for each hormone. Cholestyramine bound an average of 90% of all the steroids tested, whereas cellulose bound the least (12%). Of the other substances tested, lignin bound 87%; wheat and oat grans, 45% each; corn bran, 44%; and oat hulls, 32% of the unconjugated hormones. The conjugated steroid was less likely to bind than the unconjugated steroids. Lignin appeared to be an important component in the interaction with steroid hormones. The results support the hydrophobic of nature of adsorption and suggest that the components of the fiber in diet should be considered separately when evaluating in vivo metabolic effects. Implications include the possible modification of hormone-dependent cancer risk through dietary intervention

326

Use of an Anatomical Scalar to Control for Sex-Based Size Differences in Measures of Hyoid Excursion during Swallowing  

Science.gov (United States)

Purpose: Traditional methods for measuring hyoid excursion from dynamic videofluoroscopy recordings involve calculating changes in position in absolute units (mm). This method shows a high degree of variability across studies but agreement that greater hyoid excursion occurs inmen than in women. Given that men are typically taller than women, the…

Molfenter, Sonja M.; Steele, Catriona M.

2014-01-01

327

Sex and Gender Differences in Control of Blood Pressure  

OpenAIRE

In recent years the interest in studying the impact of sex steroids and gender on the regulation of blood pressure and cardiovascular disease has been growing. Women are protected from most cardiovascular events compared to men, until after menopause, and postmenopausal women are at increased risk of cardiovascular complications compared to premenopausal women. The pathophysiological mechanisms have not been elucidated but are not likely as simple as the presence or absence of estrogens, sinc...

Maranon, Rodrigo; Reckelhoff, Jane F.

2013-01-01

328

A developmental sex difference in hippocampal neurogenesis is mediated by endogenous oestradiol  

OpenAIRE

Abstract Background Oestradiol is a steroid hormone that exerts extensive influence on brain development and is a powerful modulator of hippocampal structure and function. The hippocampus is a critical brain region regulating complex cognitive and emotional responses and is implicated in the aetiology of several mental health disorders, many of which exhibit some degree of sex difference. Many sex differences in the adult rat brain are determined by oestradiol action during a sensitive period...

Michael, Bowers J.; Waddell Jaylyn; McCarthy Margaret M

2010-01-01

329

Genetic variants of sex hormone-binding globulin and their biological consequences  

OpenAIRE

Abstract Several hormonal and metabolic factors have been found to influence the production of sex hormone-binding globulin (SHBG). In addition, twin studies have suggested that genetic factors may also contribute to variation in SHBG levels. Given the clinical significance of SHBG in regulating bioavailable sex steroid hormones, a number of studies examined the potential association between polymorphisms of SHBG gene and serum SHBG levels as well as their possible contribution in ...

Xita, Nectaria; Tsatsoulis, Agathocles

2009-01-01

330

Sex determination strategies in 2012: towards a common regulatory model?  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Sex determination is a complicated process involving large-scale modifications in gene expression affecting virtually every tissue in the body. Although the evolutionary origin of sex remains controversial, there is little doubt that it has developed as a process of optimizing metabolic control, as well as developmental and reproductive functions within a given setting of limited resources and environmental pressure. Evidence from various model organisms supports the view that sex determination may occur as a result of direct environmental induction or genetic regulation. The first process has been well documented in reptiles and fish, while the second is the classic case for avian species and mammals. Both of the latter have developed a variety of sex-specific/sex-related genes, which ultimately form a complete chromosome pair (sex chromosomes/gonosomes. Interestingly, combinations of environmental and genetic mechanisms have been described among different classes of animals, thus rendering the possibility of a unidirectional continuous evolutionary process from the one type of mechanism to the other unlikely. On the other hand, common elements appear throughout the animal kingdom, with regard to a conserved key genes and b a central role of sex steroid control as a prerequisite for ultimately normal sex differentiation. Studies in invertebrates also indicate a role of epigenetic chromatin modification, particularly with regard to alternative splicing options. This review summarizes current evidence from research in this hot field and signifies the need for further study of both normal hormonal regulators of sexual phenotype and patterns of environmental disruption.

Angelopoulou Roxani

2012-02-01

331

Sex determination strategies in 2012: towards a common regulatory model?  

Science.gov (United States)

Sex determination is a complicated process involving large-scale modifications in gene expression affecting virtually every tissue in the body. Although the evolutionary origin of sex remains controversial, there is little doubt that it has developed as a process of optimizing metabolic control, as well as developmental and reproductive functions within a given setting of limited resources and environmental pressure. Evidence from various model organisms supports the view that sex determination may occur as a result of direct environmental induction or genetic regulation. The first process has been well documented in reptiles and fish, while the second is the classic case for avian species and mammals. Both of the latter have developed a variety of sex-specific/sex-related genes, which ultimately form a complete chromosome pair (sex chromosomes/gonosomes). Interestingly, combinations of environmental and genetic mechanisms have been described among different classes of animals, thus rendering the possibility of a unidirectional continuous evolutionary process from the one type of mechanism to the other unlikely. On the other hand, common elements appear throughout the animal kingdom, with regard to a) conserved key genes and b) a central role of sex steroid control as a prerequisite for ultimately normal sex differentiation. Studies in invertebrates also indicate a role of epigenetic chromatin modification, particularly with regard to alternative splicing options. This review summarizes current evidence from research in this hot field and signifies the need for further study of both normal hormonal regulators of sexual phenotype and patterns of environmental disruption. PMID:22357269

Angelopoulou, Roxani; Lavranos, Giagkos; Manolakou, Panagiota

2012-01-01

332

Fluorochemicals used in food packaging inhibit male sex hormone synthesis  

International Nuclear Information System (INIS)

Polyfluoroalkyl phosphate surfactants (PAPS) are widely used in food contact materials (FCMs) of paper and board and have recently been detected in 57% of investigated materials. Human exposure occurs as PAPS have been measured in blood; however knowledge is lacking on the toxicology of PAPS. The aim of this study was to elucidate the effects of six fluorochemicals on sex hormone synthesis and androgen receptor (AR) activation in vitro. Four PAPS and two metabolites, perfluorooctanoic acid (PFOA) and 8:2 fluorotelomer alcohol (8:2 FTOH) were tested. Hormone profiles, including eight steroid hormones, generally showed that 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH led to decreases in androgens (testosterone, dehydroepiandrosterone, and androstenedione) in the H295R steroidogenesis assay. Decreases were observed for progesterone and 17-OH-progesterone as well. These observations indicated that a step prior to progestagen and androgen synthesis had been affected. Gene expression analysis of StAR, Bzrp, CYP11A, CYP17, CYP21 and CYP19 mRNA showed a decrease in Bzrp mRNA levels for 8:2 monoPAPS and 8:2 FTOH indicating interference with cholesterol transport to the inner mitochondria. Cortisol, estrone and 17?-estradiol levels were in several cases increased with exposure. In accordance with these data CYP19 gene expression increased with 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH exposures indicating that this is a contributing factor to the decreased androgen and the increased estrogen levels. Overall, these results demonstrate that fluorochemicals present in food packaging materials and their metabolites can affect steroidogenesis through decreased Bzrp and increased CYP19 gene expression leading to lower androgen and higher estrogen levels. -- Highlights: ? Fluorochemicals found in 57% of paper and board food packaging were tested. ? Collectively six fluorochemicals were tested for antiandrogenic potential in vitro. ? Three out of six tested fluorochemicals inhibited synthesis of male sex hormones. ? Generally, levels of estrogens and cortisol stayed unaffected or increased. ? The effect on steroid synthesis was specific on gene expression of Bzrp and CYP19.

333

Fluorochemicals used in food packaging inhibit male sex hormone synthesis  

Energy Technology Data Exchange (ETDEWEB)

Polyfluoroalkyl phosphate surfactants (PAPS) are widely used in food contact materials (FCMs) of paper and board and have recently been detected in 57% of investigated materials. Human exposure occurs as PAPS have been measured in blood; however knowledge is lacking on the toxicology of PAPS. The aim of this study was to elucidate the effects of six fluorochemicals on sex hormone synthesis and androgen receptor (AR) activation in vitro. Four PAPS and two metabolites, perfluorooctanoic acid (PFOA) and 8:2 fluorotelomer alcohol (8:2 FTOH) were tested. Hormone profiles, including eight steroid hormones, generally showed that 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH led to decreases in androgens (testosterone, dehydroepiandrosterone, and androstenedione) in the H295R steroidogenesis assay. Decreases were observed for progesterone and 17-OH-progesterone as well. These observations indicated that a step prior to progestagen and androgen synthesis had been affected. Gene expression analysis of StAR, Bzrp, CYP11A, CYP17, CYP21 and CYP19 mRNA showed a decrease in Bzrp mRNA levels for 8:2 monoPAPS and 8:2 FTOH indicating interference with cholesterol transport to the inner mitochondria. Cortisol, estrone and 17?-estradiol levels were in several cases increased with exposure. In accordance with these data CYP19 gene expression increased with 8:2 diPAPS, 8:2 monoPAPS and 8:2 FTOH exposures indicating that this is a contributing factor to the decreased androgen and the increased estrogen levels. Overall, these results demonstrate that fluorochemicals present in food packaging materials and their metabolites can affect steroidogenesis through decreased Bzrp and increased CYP19 gene expression leading to lower androgen and higher estrogen levels. -- Highlights: ? Fluorochemicals found in 57% of paper and board food packaging were tested. ? Collectively six fluorochemicals were tested for antiandrogenic potential in vitro. ? Three out of six tested fluorochemicals inhibited synthesis of male sex hormones. ? Generally, levels of estrogens and cortisol stayed unaffected or increased. ? The effect on steroid synthesis was specific on gene expression of Bzrp and CYP19.

Rosenmai, A.K., E-mail: akjro@food.dtu.dk [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Nielsen, F.K. [Section of Toxicology, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2100 Copenhagen (Denmark); Pedersen, M. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Hadrup, N. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Trier, X. [Division of Food Chemistry, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark); Christensen, J.H. [Department of Basic Sciences and Environment, Faculty of Life Sciences, University of Copenhagen, DK-1871 Frederiksberg C. (Denmark); Vinggaard, A.M. [Division of Toxicology and Risk Assessment, National Food Institute, Technical University of Denmark, DK-2860 Søborg (Denmark)

2013-01-01

334

14-3-3 sigma is a useful immunohistochemical marker for diagnosing ovarian granulosa cell tumors and steroid cell tumors.  

Science.gov (United States)

The distinction of ovarian granulosa cell tumors (GCTs) from other sex-cord stromal tumors may be difficult histologically. Many immunohistochemical markers have been studied for this differential diagnosis, but the available markers are not entirely specific for ovarian GCT. 14-3-3 sigma has been shown to play an anti-apoptotic role in maintaining the viability of immortalized granulosa cells. However, the potential use of this molecule as an immunohistochemical marker for the diagnosis of ovarian GCT has not been investigated. A total of 103 ovarian sex-cord stromal neoplasms were immunostained with 14-3-3 sigma. These tumors included 44 adult granulosa cell, 7 juvenile granulosa cell tumors, 12 steroid cell tumors, 3 well-differentiated Sertoli-Leydig cell tumors, 5 Sertoli cell tumors, 10 thecomas, 18 fibromas, 2 primary ovarian endometrial stromal sarcomas, and 2 unclassified sex-cord stromal tumors. Ten ovaries with cystic follicles were also included as controls. Perinuclear or cytoplasmic stain was considered to be positive. Granulosa cells within the cystic follicles were positive for 14-3-3 sigma protein. All ovarian GCT (51/51) and all steroid cell tumors (12/12) were positive for 14-3-3 sigma, and all Sertoli cell tumors, fibromas, thecomas, ovarian endometrial stromal sarcomas, and sex-cord stromal tumors, unclassified, were negative for 14-3-3 sigma. The percentage of positive cell staining is statistically significant (Pcells and steroid-hormone-secreting cells. They further indicate that immunohistochemical staining of 14-3-3 sigma may be a useful marker in facilitating the diagnosis of ovarian GCT and steroid cell tumors. PMID:23370648

Chen, Longwen; Yang, Bin

2013-03-01

335

Review of Androgenic Anabolic Steroid Use  

Energy Technology Data Exchange (ETDEWEB)

An area that has been overlooked within personnel security evaluations is employee use of androgenic-anabolic steroids (AAS). Current drug testing within the federal government does not include testing for anabolic steroids, and the difficulties to implement such testing protocols-not to mention the cost involved-make AAS testing highly improbable. The basis of this report is to bring to the forefront the damage that anabolic steroids can cause from both a physical and a psychological standpoint. Most individuals who use AASs do so to increase their muscle mass because they wish to gain some type of competitive edge during athletic competition or they wish to enhance their physical features for self-satisfaction and self-esteem (i.e., body building). Security officers are one group of men who often take high doses of anabolic steroids, according to the Second Report of the Senate Standing Committee (1990). The negative psychological characteristics for AAS use is extensive and includes prominent hostility, aggressiveness, irritability, euphoria, grandiose beliefs, hyperactivity, reckless behavior, increased sexual appetite, unpredictability, poor impulse control, mood fluctuations, and insomnia. The drug may invoke a sense of power and invincibility (Leckman and Scahill, 1990). Depressive symptoms, such as anhedonia, fatigue, impaired concentration, decreased libido, and even suicidality (Pope and Katz, 1992) have been noted with steroid withdrawal. It appears that long-term users of AAS experience similar characteristics as other substance abusers (i.e., craving, dependence, and withdrawal symptoms).

T. Borges; G. Eisele; C. Byrd

2001-07-31

336

Topical steroid addiction in atopic dermatitis  

Directory of Open Access Journals (Sweden)

Full Text Available Mototsugu Fukaya,1 Kenji Sato,2 Mitsuko Sato,3 Hajime Kimata,4 Shigeki Fujisawa,5 Haruhiko Dozono,6 Jun Yoshizawa,7 Satoko Minaguchi8 1Tsurumai Kouen Clinic, Nagoya, 2Department of Dermatology, Hannan Chuo Hospital, Osaka, 3Sato Pediatric Clinic, Osaka, 4Kimata Hajime Clinic, Osaka, 5Fujisawa Dermatology Clinic, Tokyo, 6Dozono Medical House, Kagoshima, 7Yoshizawa Dermatology Clinic, Yokohama, 8Department of Dermatology, Kounosu Kyousei Hospital, Saitama, Japan Abstract: The American Academy of Dermatology published a new guideline regarding topical therapy in atopic dermatitis in May 2014. Although topical steroid addiction or red burning skin syndrome had been mentioned as possible side effects of topical steroids in a 2006 review article in the Journal of the American Academy of Dermatology, no statement was made regarding this illness in the new guidelines. This suggests that there are still controversies regarding this illness. Here, we describe the clinical features of topical steroid addiction or red burning skin syndrome, based on the treatment of many cases of the illness. Because there have been few articles in the medical literature regarding this illness, the description in this article will be of some benefit to better understand the illness and to spur discussion regarding topical steroid addiction or red burning skin syndrome. Keywords: topical steroid addiction, atopic dermatitis, red burning skin syndrome, rebound, corticosteroid, eczema

Fukaya M

2014-10-01

337

Hydroxylated polychlorinated biphenyls decrease circulating steroids in female polar bears (Ursus maritimus).  

Science.gov (United States)

As a top predator in the Arctic food chain, polar bears (Ursus maritimus) are exposed to high levels of persistent organic pollutants (POPs). Because several of these compounds have been reported to alter endocrine pathways, such as the steroidogenesis, potential disruption of the sex steroid synthesis by POPs may cause implications for reproduction by interfering with ovulation, implantation and fertility. Blood samples were collected from 15 female polar bears in Svalbard (Norway) in April 2008. The concentrations of nine circulating steroid hormones; dehydroepiandrosterone (DHEA), androstenedione (AN), testosterone (TS), dihydrotestosterone (DHT), estrone (E1), 17?-estradiol (?E2), 17?-estradiol (?E2), pregnenolone (PRE) and progesterone (PRO) were determined. The aim of the study was to investigate associations among circulating levels of specific POP compounds and POP-metabolites (hydroxylated PCBs [OH-PCBs] and hydroxylated PBDEs [OH-PBDEs]), steroid hormones, biological and capture variables in female polar bears. Inverse correlations were found between circulating levels of PRE and AN, and circulating levels of OH-PCBs. There were no significant relationships between the steroid concentrations and other analyzed POPs or the variables capture date and capture location (latitude and longitude), lipid content, condition and body mass. Although statistical associations do not necessarily represent direct cause-effect relationships, the present study indicate that OH-PCBs may affect the circulating levels of AN and PRE in female polar bears and that OH-PCBs thus may interfere with the steroid homeostasis. Increase in PRO and a decrease in AN concentrations suggest that the enzyme CYP17 may be a potential target for OH-PCBs. In combination with natural stressors, ongoing climate change and contaminant exposure, it is possible that OH-PCBs may disturb the reproductive potential of polar bears. PMID:25725300

Gustavson, Lisa; Ciesielski, Tomasz M; Bytingsvik, Jenny; Styrishave, Bjarne; Hansen, Martin; Lie, Elisabeth; Aars, Jon; Jenssen, Bjørn M

2015-04-01

338

Sex differences in angiotensin II- induced hypertension  

Directory of Open Access Journals (Sweden)

Full Text Available Sex differences in the development of hypertension and cardiovascular disease have been described in humans and in animal models. In this paper we will review some of our studies which have as their emphasis the examination of the role of sex differences and sex steroids in modulating the central actions of angiotensin II (ANG II via interactions with free radicals and nitric oxide, generating pathways within brain circumventricular organs and in central sympathomodulatory systems. Our studies indicate that low-dose infusions of ANG II result in hypertension in wild-type male mice but not in intact wild-type females. Furthermore, we have demonstrated that ANG II-induced hypertension in males is blocked by central infusions of the androgen receptor antagonist, flutamide, and by central infusions of the superoxide dismutase mimetic, tempol. We have also found that, in comparison to females, males show greater levels of intracellular reactive oxygen species in circumventricular organ neurons following long-term ANG II infusions. In female mice, ovariectomy, central blockade of estrogen receptors or total knockout of estrogen a receptors augments the pressor effects of ANG II. Finally, in females but not in males, central blockade of nitric oxide synthase increases the pressor effects of ANG II. Taken together, these results suggest that sex differences and estrogen and testosterone play important roles in the development of ANG II-induced hypertension.

B. Xue

2007-05-01

339

Sex differences in angiotensin II- induced hypertension  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Sex differences in the development of hypertension and cardiovascular disease have been described in humans and in animal models. In this paper we will review some of our studies which have as their emphasis the examination of the role of sex differences and sex steroids in modulating the central ac [...] tions of angiotensin II (ANG II) via interactions with free radicals and nitric oxide, generating pathways within brain circumventricular organs and in central sympathomodulatory systems. Our studies indicate that low-dose infusions of ANG II result in hypertension in wild-type male mice but not in intact wild-type females. Furthermore, we have demonstrated that ANG II-induced hypertension in males is blocked by central infusions of the androgen receptor antagonist, flutamide, and by central infusions of the superoxide dismutase mimetic, tempol. We have also found that, in comparison to females, males show greater levels of intracellular reactive oxygen species in circumventricular organ neurons following long-term ANG II infusions. In female mice, ovariectomy, central blockade of estrogen receptors or total knockout of estrogen a receptors augments the pressor effects of ANG II. Finally, in females but not in males, central blockade of nitric oxide synthase increases the pressor effects of ANG II. Taken together, these results suggest that sex differences and estrogen and testosterone play important roles in the development of ANG II-induced hypertension.

B., Xue; A.K., Johnson; M., Hay.

2007-05-01

340

Steroidal alkaloid toxicity to fish embryos.  

Science.gov (United States)

Embryos of two species of fish were evaluated for their suitability as model systems for steroidal alkaloid toxicity, the Japanese rice fish, medaka (Oryzius latipes) and the rainbow trout (Oncorhynchus mykiss). Additionally, the equine neurotoxic sesquiterpene lactone repin, was also tested. A PROBIT program was used to evaluate the EC1, EC50 and EC99 as well as the associated confidence limits. The steroidal alkaloids tested were the Solanum potato glycoalkaloids alpha-chaconine, alpha-solanine, the aglyclones solanidine and solasodine and the Veratrum alkaloid, jervine. Embryo mortality, likely due to structural or functional abnormalities in the early development stages of the embryo, were the only response observed in both species. The rainbow trout exhibited a toxic response to chaconine, solasidine, repin and solanine but the medaka embryos were only affected by the compounds, chaconine and solanine. Rainbow trout may indeed serve as a good lower vertebrate model for studying the toxicity of steroidal alkaloids. PMID:8430437

Crawford, L; Kocan, R M

1993-02-01

341

Iatrogenic Cushing's syndrome due to topical steroid  

Directory of Open Access Journals (Sweden)

Full Text Available Iatrogenic Cushing's syndrome due to the use of steroid medication is extremely common because of the widespread use of these medicines in the treatment of many diseases. Systemic absorption of topical glucocorticoids may result in hypothalamic-pituitary-adrenal axis dysfunction in children. In this study, two cases with Cushing stigmata were presented. They had been administered topical corticosteroid treatment because of diaper dermatitis. We suggest that physicians should be alert to the signs of Cushing's syndrome in patients on topical steroid therapy. In addition, these findings show that the use of topical steroids, especially during infancy, should be limited to a short period and less potent agents should be preferred.

Nihal Hatipo?lu

2007-04-01

342

Altered Amphibian Secondary Sex Characteristics following Exposure to Model Endocrine Disruptors  

Science.gov (United States)

The formation of the secondary sex characteristics, oviducts and nuptial pads, are under the control of steroid hormones in frogs and as such are potential targets for endocrine-disrupting compounds. Oviducts are large, convoluted tubules derived from the Mullerian ducts in whic...

343

Dimensiones del músculo masetero medido mediante ultrasonido, según sexo / Masseter muscle dimensions measured by ultrasound per sex  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish INTRODUCCIÓN: para establecer las dimensiones en profundidad, ancho y largo del músculo masetero según sexo, se realizó un estudio analítico no experimental entre pacientes seleccionados que acudieron al servicio de ecografía del Hospital Base de Linares, Chile entre los meses de julio y septiembre [...] del año 2005. MÉTODOS: la muestra quedó determinada por 180 músculos maseteros, 90 de ellos pertenecientes a individuos de sexo femenino y 90 pertenecientes a individuos de sexo masculino. Se realizaron las mediciones de cada una de las dimensiones del músculo masetero utilizando para ello un examen imaginológico ecográfico. La muestra se sometió al análisis estadístico ANOVA. RESULTADOS: los individuos de sexo masculino presentan músculos maseteros con profundidades promedio de 10,8 ± 1,6 mm y los individuos de sexo femenino profundidades promedio de 8,1 ± 1,4 mm. CONCLUSIONES: de acuerdo con lo encontrado, se concluye que en individuos de sexo masculino con una profundidad del músculo masetero mayor a 12,4 mm y en individuos de sexo femenino con una profundidad del músculo masetero mayor a 9,5 mm se podrían considerar el diagnóstico de hipertrofia maseterina. Abstract in english INTRODUCTION: in order to establish the dimensions in depth, width and length of the masseter muscle according to gender, a non analytical experimental observational study was performed on selected patients who attended the echography service at the Base Hospital of Linares-Chile between July and Se [...] ptember 2005. METHODS: the sample consisted of 180 masseter muscles, 90 from female individuals and 90 from male individuals. Measurements of each masseter muscle were performed utilizing an echographic exam. ANOVA test statistical analysis was performed. RESULTS: the masseter muscle depth on male individuals has an averaged 10.8 ± 1.6 mm and on female individuals an average depth of 8.1 ± 1.4 mm. CONCLUSIONS: according to the findings, we concluded that in male individuals with a depth of the masseter muscle higher to 12.4 mm and in female individuals with a depth of masseter higher to 9.5 mm could be considered a diagnosis of masseteric hypertrophy.

Raúl, Frugone A; Arnoldo, Hernández C; Hernán, Valenzuela P; Víctor, Retamal.

2010-12-01

344

Dimensiones del músculo masetero medido mediante ultrasonido, según sexo Masseter muscle dimensions measured by ultrasound per sex  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCCIÓN: para establecer las dimensiones en profundidad, ancho y largo del músculo masetero según sexo, se realizó un estudio analítico no experimental entre pacientes seleccionados que acudieron al servicio de ecografía del Hospital Base de Linares, Chile entre los meses de julio y septiembre del año 2005. MÉTODOS: la muestra quedó determinada por 180 músculos maseteros, 90 de ellos pertenecientes a individuos de sexo femenino y 90 pertenecientes a individuos de sexo masculino. Se realizaron las mediciones de cada una de las dimensiones del músculo masetero utilizando para ello un examen imaginológico ecográfico. La muestra se sometió al análisis estadístico ANOVA. RESULTADOS: los individuos de sexo masculino presentan músculos maseteros con profundidades promedio de 10,8 ± 1,6 mm y los individuos de sexo femenino profundidades promedio de 8,1 ± 1,4 mm. CONCLUSIONES: de acuerdo con lo encontrado, se concluye que en individuos de sexo masculino con una profundidad del músculo masetero mayor a 12,4 mm y en individuos de sexo femenino con una profundidad del músculo masetero mayor a 9,5 mm se podrían considerar el diagnóstico de hipertrofia maseterina.INTRODUCTION: in order to establish the dimensions in depth, width and length of the masseter muscle according to gender, a non analytical experimental observational study was performed on selected patients who attended the echography service at the Base Hospital of Linares-Chile between July and September 2005. METHODS: the sample consisted of 180 masseter muscles, 90 from female individuals and 90 from male individuals. Measurements of each masseter muscle were performed utilizing an echographic exam. ANOVA test statistical analysis was performed. RESULTS: the masseter muscle depth on male individuals has an averaged 10.8 ± 1.6 mm and on female individuals an average depth of 8.1 ± 1.4 mm. CONCLUSIONS: according to the findings, we concluded that in male individuals with a depth of the masseter muscle higher to 12.4 mm and in female individuals with a depth of masseter higher to 9.5 mm could be considered a diagnosis of masseteric hypertrophy.

Raúl Frugone A

2010-12-01

345

Birth cohort and the specialization gap between same-sex and different-sex couples.  

Science.gov (United States)

We examine differences in household specialization between same-sex and different-sex couples within and across three birth cohorts: Baby Boomers, Generation X, and Generation Y. Using three measures of household specialization, we find that same-sex couples are less likely than their different-sex counterparts to exhibit a high degree of specialization. However, the "specialization gap" between same-sex and different-sex couples narrows across birth cohorts. These findings are indicative of a cohort effect. Our results are largely robust to the inclusion of a control for the presence of children and for subsets of couples with and without children. We provide three potential explanations for why the specialization gap narrows across cohorts. First, different-sex couples from more recent birth cohorts may have become more like same-sex couples in terms of household specialization. Second, social and legal changes may have prompted a greater degree of specialization within same-sex couples relative to different-sex couples. Last, the advent of reproductive technologies, which made having children easier for same-sex couples from more recent birth cohorts, could result in more specialization in such couples relative to different-sex couples. PMID:24585040

Giddings, Lisa; Nunley, John M; Schneebaum, Alyssa; Zietz, Joachim

2014-04-01

346

Steroids pretreatment in assisted reproduction cycles.  

Science.gov (United States)

The objective is to present an overview of trials and appreciate the relevant data on the effect of steroids pretreatment (oral contraceptives, 17?-estradiol and estradiol valerate) in assisted reproduction cycles. The subject of the study is to evaluate the clinical characteristics during steroids pretreatment cycles focused on the prevention of ovarian cysts, the positive contraceptive effect on the onset of regular period during long gonadotropin releasing hormone agonist protocol. In gonadotropin releasing hormone antagonist protocol the review is interested in supporting ovarian stimulation in low responders, the idea of cycle scheduling and improving treatment outcomes. The method is a review from MEDLINE/Pubmed database between 1994 and July 2012. We identified 15 randomised controlled trials (n=3069 patients). One trail (n=83 patients) assessed GnRH agonist protocol with or without steroids pretreatment, 8 trials (n=1884 patients) assessed GnRH antagonist protocols with or without steroids pretreatment and 6 trials (n=1102 patients) assessed GnRH antagonist protocols versus agonist ones with steroid pretreatment. Data demonstrates that oral contraceptives offer the effective prevention of functional ovarian cysts, the predictable onset of period during desensitisation. Existing data suggest that pretreatment with oral contraceptive pills or estradiol valerate give no advantage concerning number of oocytes or pregnancy rate. Pretreatment with oral contraceptive pills aiming to avoid weekend oocytes retrievals has to be more elucidated. In low responders oral contraceptive pill pretreatment may be beneficial in improving ovarian responses by reducing the amount of gonadotropins and the number of days required for ovarian stimulation. Current research indicates that also 17?-estradiol may be encouraging pretreatment in low responders and in cycle scheduling. This article is part of a Special Issue entitled 'Pregnancy and Steroids'. PMID:23685395

Sobotka, V; Streda, R; Mardesic, T; Tosner, J; Heracek, J

2014-01-01

347

Sex Determination Using Mastoid Process Measurements in Brazilian Skulls Determinación del Sexo Usando Mediciones en el Proceso Mastoides en Cráneos Brasileños  

OpenAIRE

The mastoid process characteristics are of great utility in the diagnosis of sex. De Paiva & Segre (2003) described that sex diagnosis was possible based on the determination of the área of the triangle formed by the points porion, mastoidale, and asterion. The purpose of this study was to determine the existence of sexual dimorphism in the dimensions and the área of the mastoid triangle using statistical and discriminant function analysis. A total of 81 skulls of Brazilian individuáis tha...

Iván Claudio Suazo Galdames; Daniela Alejandra Zavando Matamala; Ricardo Luiz Smith

2008-01-01

348

Effects of cadmium and zinc on steroid metabolism and steroid level in the sea star Asterias rubens L.  

Science.gov (United States)

Steroid metabolism was studied in gonads and pyloric caeca of male and female sea stars which had been exposed to cadmium or zinc for 3 weeks. Steroid metabolism had increased in animals exposed to heavy metals. Significant increase of the enzyme activity was observed for 17 alpha-hydroxylase in the pyloric caeca of female animals exposed to zinc (pregnenolone----17 alpha-hydroxypregnenolone) or cadmium (progesterone----17 alpha-hydroxyprogesterone), for 17 beta-hydroxysteroiddehydrogenase in the gonads of female animals (dehydroepiandrosterone----androstenediol) and in pyloric caeca of male animals (androstenedione----testosterone) after exposure to cadmium, and for 5 alpha-reductase (progesterone----5 alpha-pregnane-3,20-dione) in ovaries of cadmium exposed sea star. There is some evidence that pregnenolone metabolism in male and female animals is affected by zinc in a different way. The effect of cadmium on the esterification of androstenedione differed highly significantly among male and female animals. It was concluded that the main way of entrance of cadmium into sea stars is via the surrounding medium and not via the food consumed. Testosterone and progesterone levels in, respectively, gonads of female and pyloric caeca of male sea stars which had been exposed to cadmium were significantly higher than the corresponding values in control animals. The effect of zinc exposure on testosterone level in pyloric caeca is significantly different for both sexes. Cadmium interacts directly with the esterification of testosterone, strongly stimulating this process. Cadmium stimulates the production of testosterone by action at the level of the biosynthesis of 17 beta-hydroxysteroiddehydrogenase. PMID:2881732

Voogt, P A; den Besten, P J; Kusters, G C; Messing, M W

1987-01-01

349

Steroid metabolism in the mouse placenta  

International Nuclear Information System (INIS)

The purpose of the study described in this thesis was to investigate the capacity for steroid synthesis of the mouse placenta - especially the production of progesterone, androgens and estrogens - and to determine, if possible, the relation of steroid synthesis to special cell types. In an introductory chapter the androgen production in the mouse placenta is surveyed by means of a histochemical and bioindicator study of different stages of development of the placenta. The metabolism of [3H]-dehydroepiandrosterone and [3H]-progesterone by mouse placental tissue in vitro is studied. The metabolism of [3H]-progesterone by the mouse fetal adrenal in vitro is also studied

350

Steroidal saponins from Paris polyphylla var. yunnanensis.  

Science.gov (United States)

Eleven steroidal saponins, along with seven known steroidal saponins, were isolated from rhizomes of Paris polyphylla var. yunnanensis. Their chemical structures were elucidated on the basis of spectroscopic analyses and acid hydrolysis. Two of these compounds contained a spirostanol saponin aglycone, hitherto unknown in Nature. The isolated compounds were tested for their cytotoxic effects on human nasopharyngeal carcinoma epithelial (CNE) cells, and seven compounds displayed more potent inhibitory effects than cisplatin (the positive control). One compound with diosgenin and tetrasaccharide moieties possessed the strongest inhibitory effect on CNE cells through the induction of apoptosis and cell cycle arrest. PMID:22748777

Wu, Xia; Wang, Lei; Wang, Hui; Dai, Yi; Ye, Wen-Cai; Li, Yao-Lan

2012-09-01

351

Steroid allergy in patients with inflammatory bowel disease.  

LENUS (Irish Health Repository)

Background: Contact allergy to a steroid enema leading to worsening of inflammatory bowel disease (IBD) has recently been reported. This study was designed to look for evidence of steroid allergy in patients with IBD.

Malik, M

2007-11-01

352

Effect of rearing water temperature on protandrous sex inversion in cultured Asian Seabass (Lates calcarifer).  

Science.gov (United States)

Asian Seabass, Lates calcarifer (Bloch, 1790), is a protandrous species cultured for Aquaculture. The cultured Asian Seabass in Australia exhibits precocious sex inversion before 2years of age. This phenomenon highly affects on maintaining a proper broodstock in a hatchery. The effect of temperature on sex inversion inducement in Asian Seabass was thus investigated at five different temperature regimes experienced in Australia. Asian Seabass (14months) grown in fresh water under natural temperature in a commercial farm in Queensland were transported to the research facility at James Cook University, Australia and held in fresh water at 28°C until acclimatized to the experimental conditions. Fish were acclimated to the experimental conditions (30ppt salinity) over the first and final week (22°C, 25°C, 28°C, 31°C and 34°C) of one month acclimatizing period. Fish were fed daily with a commercial pellet (50% protein, 18MJkg(-1)) to satiety. Blood, brain and gonad collected before transfer to the experimental temperature regime in the final week of acclimatization and at the end of the experiment were analysed. Plasma sex steroids level and aromatase activity of brain and gonad were also measured. There was an increase in plasma estradiol levels with increasing temperature from 25°C while no significant difference was observed among all treatment temperatures except at 25°C. However, fish held at 22°C showed higher estradiol level than at 25°C and 28°C. Significantly higher (p0.05) observed. The Average aromatase activity in gonad was highest at 31°C followed by at 34°C and 28°C. No or very low level of gonad aromatase activity recorded in fish sacrificed prior to treatment. The aromatase activity was greater in brain than in gonad suggesting that the aromatase produced in the brain yet to transfer to the gonad or brain is the first place to response for culture environmental temperature. It is concluded that plasma sex steroids levels and aromatase activity in Asian Seabass have positive response to increasing temperature in culture facilities. PMID:22155035

Athauda, Saman; Anderson, Trevor; de Nys, Rocky

2012-02-01

353

“Any Condomless Anal Intercourse” is No Longer an Accurate Measure of HIV Sexual risk Behavior in Gay and Other Men Who have Sex with Men  

Science.gov (United States)

Background: Condomless anal intercourse (CLAI) has long been recognized as the primary mode of sexual transmission of HIV in gay and other men who have sex with men (MSM). A variety of measures of CLAI have been commonly used in behavioral surveillance for HIV risk and to forecast trends in HIV infection. However, gay and other MSM’s sexual practices changed as the understanding of disease and treatment options advance. In the present paper, we argue that summary measures such as “any CLAI” do not accurately measure HIV sexual risk behavior. Methods: Participants were 1,427 HIV-negative men from the Health in Men cohort study run from 2001 to 2007 in Sydney, Australia, with six-monthly interviews. At each interview, detailed quantitative data on the number of episodes of insertive and receptive CLAI in the last 6?months were collected, separated by partner type (regular vs. casual) and partners’ HIV status (negative, positive, and HIV status unknown). Results: A total of 228,064 episodes of CLAI were reported during the study period with a mean of 44 episodes per year per participant (median: 14). The great majority of CLAI episodes were with a regular partner (92.6%), most of them with HIV-negative regular partners (84.8%). Participants were more likely to engage in insertive CLAI with casual than with regular partners (66.7 vs. 55.3% of all acts of CLAI with each partner type, p?measure of HIV behavioral risk is not helpful in understanding the current drivers of HIV transmission in the community. PMID:25774158

Jin, Fengyi; Prestage, Garrett P.; Mao, Limin; Poynten, I. Mary; Templeton, David J.; Grulich, Andrew E.; Zablotska, Iryna

2015-01-01

354

The effect of sex ratios on suicide.  

Science.gov (United States)

Whereas sex ratios are likely to affect the likelihood of marriage, how sex ratios affect health and survival is underexplored. This study uses suicide as a measure of mental health and examines how suicides are affected by sex ratios. As women tend to marry men older than themselves, shrinking populations will lead to higher sex ratios (i.e., higher proportions of men) in the marriage market. Using data from Japan, I find that high sex ratios, both early-life and current, are correlated with higher male suicide rates, whereas female suicide rates are generally not affected. The results of this study have important implications for public health in countries where imbalanced sex ratios are a concern. PMID:23943552

Kuroki, Masanori

2014-12-01

355

Tacrolimus and low-dose steroid immunosuppression preserves bone mass after renal transplantation.  

Science.gov (United States)

Bone loss, a recognized complication of renal transplantation (TP), is mainly attributed to steroids. The effect of other immunosuppressive agents on patients' bone mass is difficult to distinguish from that of steroids. In this study, we evaluate the evolution of bone mass density over the first 12 months following renal TP in two groups of patients given either low-dose steroids with tacrolimus ( n=7) or normal-dose steroids and cyclosporine ( n=19). Bone mineral density (BMD) of the lumbar spine, total hip, and hip subregions and total-body bone mineral content (BMC) were measured by dual-energy X-ray absorptiometry within the first 15 days, and 1 year after TP. Biological markers of bone turnover (serum calcium, phosphate, total alkaline phosphatase activity, intact parathyroid hormone, bone-specific alkaline phosphatase, calcitriol, and urinary pyridinolines) were regularly measured during follow-up. After TP, renal function improved rapidly in all patients. One year after TP, bone mass had decreased significantly in the cyclosporine group in all investigated sites. By contrast it had increased in the tacrolimus group. In order to compare the evolution of bone mass in patients given similar amounts of steroids, the cyclosporine group was subdivided in tertiles according to the 1-year cumulative oral intake of prednisolone. A significant bone loss was still observed in the low-steroid cyclosporine subgroup but not in the tacrolimus group, despite the similar steroids intake (3.5+/-0.5 g and 2.7+/-1 g, respectively). Bone gain in the tacrolimus group occurred despite a previous longer dialysis duration and a higher number of postmenopausal women who were not receiving hormone substitutes. Long-term evaluation of bone density (3-5 years post-TP) confirmed the bone gain in the tacrolimus patients. Interestingly, the profile of the biological markers of bone turnover appeared better in patients prescribed tacrolimus than in those given cyclosporine, though the differences did not reach statistical significance. Weconclude that tacrolimus associated with low-dose steroids might better preserve bone mass after renal TP than cyclosporine and normal doses of steroids. PMID:11935163

Goffin, Eric; Devogelaer, Jean-Pierre; Lalaoui, Abdelhamid; Depresseux, Geneviève; De Naeyer, Philippe; Squifflet, Jean-Paul; Pirson, Yves; van Ypersele de Strihou, Charles

2002-03-01

356

Spontaneous rupture of the anterior cruciate ligament after anabolic steroids.  

OpenAIRE

Anabolic steroids remain popular among body builders and power athletes despite numerous warning about their side effects. A case of spontaneous rupture of the anterior cruciate ligament is reported in a bodybuilder taking steroids. While there are many published reports of tendon rupture associated with steroid intake, the authors could find no report relating to ligament disruption.

Freeman, B. J.; Rooker, G. D.

1995-01-01

357

Steroids and Other Ergogenic Aids: A Resource Guide.  

Science.gov (United States)

Steroids have become one of society's "short cuts" to athletic prowess and success. This guide includes information and teaching materials for educators and others who work with youth on how to teach that steroids are drugs, that drugs can harm and kill, and that a "no-use" policy applies to steroids as well as to alcohol and other drugs. It is…

Virginia State Dept. of Education, Richmond.

358

Potential role of female sex hormones in the pathophysiology of migraine.  

Science.gov (United States)

Clinical evidence indicates that female sex steroids may contribute to the high prevalence of migraine in women, as well as changes in the frequency or severity of migraine attacks that are in tandem with various reproductive milestones in women's life. While female sex steroids do not seem to be involved in the pathogenesis of migraine per se, they may modulate several mediators and/or receptor systems via both genomic and non-genomic mechanisms; these actions may be perpetuated at the central nervous system, as well as at the peripheral (neuro)vascular level. For example, female sex steroids have been shown to enhance: (i) neuronal excitability by elevating Ca(2+) and decreasing Mg(2+) concentrations, an action that may occur with other mechanisms triggering migraine; (ii) the synthesis and release of nitric oxide (NO) and neuropeptides, such as calcitonin gene-related peptide CGRP, a mechanism that reinforces vasodilatation and activates trigeminal sensory afferents with a subsequent stimulation of pain centres; and (iii) the function of receptors mediating vasodilatation, while the responses of receptors inducing vasoconstriction are attenuated. The serotonergic, adrenergic and gamma-aminobutyric acid (GABA)-ergic systems are also modulated by sex steroids, albeit to a varying degree and with potentially contrasting effects on migraine outcome. Taken together, female sex steroids seem to be involved in an array of components implicated in migraine pathogenesis. Future studies will further delineate the extent and the clinical relevance of each of these mechanisms, and will thus expand the knowledge on the femininity of migraine. PMID:17069890

Gupta, Saurabh; Mehrotra, Suneet; Villalón, Carlos M; Perusquía, Mercedes; Saxena, Pramod R; MaassenVanDenBrink, Antoinette

2007-02-01

359

Biochemical and pharmacogenetic dissection of human steroid 5 alpha-reductase type II.  

Science.gov (United States)

Human prostatic steroid 5alpha-reductase, encoded by the SRD5A2 gene on chromosome band 2p23, catalyses the irreversible conversion of testosterone to dihydrotestosterone (DHT), the most active androgen in the prostate, with NADPH as its cofactor. This enzyme has never been purified but a number of competitive inhibitors have been developed for this enzyme since increased steroid 5alpha-reductase activity may cause benign prostatic hypertrophy and prostate cancer. We report here the detailed biochemical and pharmacogenetic dissection of the human enzyme by analysing 10 missense substitutions and three double mutants which are all naturally found in humans. Nine of these 13 mutants reduce activity (measured as Vmax) by 20% or more, three increase steroid 5alpha-reductase by more than 15% and one results in essentially unaltered kinetic properties suggesting that it is a truly neutral ('polymorphic') amino acid substitution. Substantial pharmacogenetic variation among the mutants was also observed when three competitive inhibitors, finasteride, GG745 (dutasteride) and PNU157706, were investigated. Our studies not only define the substrate and cofactor binding sites of human steroid 5alpha-reductase, but also have significant consequences for the pharmacological usage of steroid 5alpha-reductase inhibitors in human patients treated for prostatic conditions. PMID:10898110

Makridakis, N M; di Salle, E; Reichardt, J K

2000-07-01

360

In vivo MRI evaluation of anabolic steroid precursor growth effects in a guinea pig model  

Science.gov (United States)

Anabolic steroids are widely used to increase skeletal muscle (SM) mass and improve physical performance. Some dietary supplements also include potent steroid precursors or active steroid analogs such as nandrolone. Our previous study reported the anabolic steroid effects on SM in a castrated guinea pig model with SM measured using a highly quantitative magnetic resonance imaging (MRI) protocol. The aim of the current study was to apply this animal model and in vivo MRI protocol to evaluate the growth effects of four widely used over-the-counter testosterone and nandrolone precursors: 4-androstene-3 17-dione (androstenedione), 4-androstene-3? 17?-diol (4-androsdiol), 19-nor-4-androstene-3?-17?-diol (bolandiol) and 19-nor-4-androstene-3 17-dione (19-norandrostenedione). The results showed that providing precursor to castrated male guinea pigs led to plasma steroid levels sufficient to maintain normal SM growth. The anabolic growth effects of these specific precursors on individual and total muscle volumes, sexual organs, and total adipose tissue over a 10-week treatment period, in comparison with those in the respective positive control testosterone and nandrolone groups, were documented quantitatively by MRI. PMID:19463691

Tang, Haiying; Vasselli, Joseph R.; Tong, Christopher; Heymsfield, Steven B.; Wu, Ed X.

2015-01-01

361

Constraints on temperature-dependent sex determination in the leopard gecko ( Eublepharis macularius): response to Kratochvil et al.  

Science.gov (United States)

Kratochvil et al. (Naturwissenschaften 95:209 215, 2008) reported recently that in the leopard gecko ( Eublepharis macularius) of the family Eublepharidae with temperature-dependent sex determination (TSD), clutches in which eggs were incubated at the same temperature produce only same-sex siblings. Interpreting this result in light of studies of sex steroid hormone involvement in sex determination, they suggested that maternally derived yolk steroid hormones could constrain sex-determining mechanisms in TSD reptiles. We have worked extensively with this species and have routinely incubated clutches at constant temperatures. To test the consistency of high frequency same-sex clutches across different incubation temperatures, we examined our records of clutches at the University of Texas at Austin from 1992 to 2001. We observed that clutches in which eggs were incubated at the same incubation temperature produced mixed-sex clutches as well as same-sex clutches. Furthermore, cases in which eggs within a clutch were separated and incubated at different temperatures produced the expected number of mixed-sex clutches. These results suggest that maternal influences on sex determination are secondary relative to incubation temperature effects.

Huang, Victoria; Sakata, Jon T.; Rhen, Turk; Coomber, Patricia; Simmonds, Sarah; Crews, David

2008-12-01

362

A critical review of the efficacy of non-steroidal anti-inflammatory drugs in depression.  

Science.gov (United States)

Non-steroidal anti-inflammatory drugs (NSAIDs) require further investigation given mixed results regarding efficacy. We critically and systematically reviewed the literature to determine whether selective COX-2 and non-selective COX inhibitor NSAIDs as adjuncts or monotherapy affect depressive symptoms. Electronic databases including Embase, PsycINFO, Ovid Medline, ScienceDirect, Google Scholar and the Cochrane Central Register of Controlled Trials database were searched up to September 2013. We utilised randomised controlled trials (RCTs), cohort studies and an open label study examining the efficacy of NSAIDs as adjuncts or monotherapy on depressive symptoms in subjects without major comorbidities. There were a total of 6 studies exploring the efficacy of selective COX-2 inhibitor NSAIDs on depressive symptoms with a total of 2706 subjects from 6 RCTs. 4 of the RCTs showed a significant effect of NSAIDs; 2 demonstrated no effect. There were a total of 5 studies exploring the efficacy of non-selective COX inhibitor NSAIDs on depressive symptoms with a total of 7978 subjects. There was 1 RCT, 3 cohort studies and 1 open label pilot study. The RCT failed to show a significant result. 1 of the retrospective cohort studies showed a positive result, with the other 2 showing no effect. The pilot study showed a positive result for NSAIDs. These studies demonstrated significant methodological heterogeneity (i.e. age range, sex, presence of antidepressant use, method of depression measure, severity of depressive symptoms, duration and study design (RCT vs. cohort)). The efficacy of NSAIDs on depressive symptoms appears negligible, however firm conclusions are difficult given the inconsistent findings and substantial methodological heterogeneity. Further high quality research is needed to explore NSAID efficacy in clinical and biological subtypes of depression, as monotherapy and adjunct with various antidepressants, and across various ages. PMID:25455584

Eyre, Harris A; Air, Tracy; Proctor, Simon; Rositano, Sebastian; Baune, Bernhard T

2015-03-01

363

[Anabolic steroids on the German black market].  

Science.gov (United States)

Anabolic steroids found in the illegal market often do not contain ingredients declared on the label. 42 products found in the black market in Germany were analysed by gas chromatography/mass spectrometry. 15 of these products did not contain the expected ingredients. Authentic and counterfeit products are introduced. PMID:9313064

Musshoff, F; Daldrup, T; Ritsch, M

1997-01-01

364

Sox and Drugs: Baseball, Steroids and Physics  

Science.gov (United States)

The sports world is in an uproar over performance-enhancing drugs. In the United States steroids in baseball have received the most attention, in part because the purported effects are much more dramatic than in any other sport. From 1995-2003 a few players hit home runs at rates 20-50% higher than the best sluggers of the preceding century. Could steroids really increase home-run performance that much? I will describe a model that combines estimates of the physiological effects of steroids, known baseball physics, and reasonable models of batting effectiveness for highly skilled hitters. A 10% increase in muscle mass, which can reasonably be expected from steroid use, increases the speed of a batted ball by 3%. Because home runs are relatively rare events on the tail of a batter's range distribution, even this modest change in ball speed can increase the proportion of batted balls that result in home runs by 30 -- 70%, enough to account for the record-shattering performances of the recent past. I will also describe some of the attention -- both welcome and not -- that comes to the unsuspecting physicist who wades into such emotionally troubled waters.

Tobin, Roger

2008-03-01

365

New steroid molecules affecting membrane proteins.  

Czech Academy of Sciences Publication Activity Database

Praha : Czech Chemical Society, 2014. s. 78. [Liblice 2014. Advances in Organic, Bioorganic and Pharmaceutical Chemistry /49./. 07.11.2014-09.11.2014, Lázn? B?lohrad] R&D Projects: GA TA ?R(CZ) TE01020028; GA ?R(CZ) GAP303/12/1464 Institutional support: RVO:61388963 Keywords : NMDAR * steroids Subject RIV: CC - Organic Chemistry

Kou?ilová, Kate?ina; Kudová, Eva; Chodounská, Hana; Navrátil, Michal; Konvalinka, Jan; Vyklický ml., Ladislav; Krausová, Barbora

366

Anabolic steroid accelerated multicompartment syndrome following trauma  

OpenAIRE

The case is reported of a 23 year old male body builder who was involved in a road traffic accident after taking anabolic steroids. The resulting trauma caused a severe life threatening acute multicompartment syndrome resulting in the need for urgent multiple fasciotomies.

Bahia, H.; Platt, A.; Hart, N.; Baguley, P.

2000-01-01

367

Cardiac tissue Doppler in steroid users.  

Science.gov (United States)

Anabolic steroids cause a variety of side effects, among them a slight concentric left ventricular hypertrophy. The objective of the present study was to clarify if they also induce alterations in left ventricular function. 14 male body builders with substantial intake of anabolic steroids (users) were examined by standard echocardiography and cardiac tissue Doppler imaging. They were compared to 11 steroid-free strength athletes (non-users) and 15 sedentary control subjects. Users showed an increased left ventricular muscle mass index. The ratio of peak transmitral blood flow velocities during early diastolic filling and atrial contraction did not differ between groups (users: 1.4 +/- 0.3; non-users: 1.7 +/- 0.5; controls: 1.4 +/- 0.4). In contrast an analogous tissue Doppler parameter, the ratio of myocardial velocities during early and late ventricular filling in the basal septum, was significantly lower in users (1.2 +/- 0.4) when compared to non-users (1.6 +/- 0.5) or controls (1.6 +/- 0.6). The velocity gradient during myocardial E-wave in the posterior wall showed significantly lower values in users (3.8 +/- 1.3 1/s) as compared to controls (5.8 +/- 2.5 1/s). There were no differences in systolic function. Summarizing strength athletes abusing anabolic steroids show negative alterations in diastolic function. PMID:17549658

Krieg, A; Scharhag, J; Albers, T; Kindermann, W; Urhausen, A

2007-08-01

368

Epidural steroid injection for lumbosacral radiculopathy  

International Nuclear Information System (INIS)

Low back pain combined with radicular pain remains as one of the most challenging musculoskeletal problems for its therapeutic management. This malady results from nerve root impingement and/or inflammation that causes neurologic symptoms in the distribution of the affected nerve root(s) Conservative treatment, percutaneous spine interventions and surgery have all been used as treatment; and the particular treatment that's chosen depends on the severity of the clinical and neurologic presentation. In 1930, Evans reported that sciatica could treated by epidural injection. The use of epidural corticosteroid injections for the treatment of axial and radicular back pain was first reported in 1953. Epidural steroid injections are currently used by many medical professionals for the treatment of lumbosacral radiculopathy. Performing 'blind' epidural steroid injection lacks target specificity that often results in incorrect delivery of medication to the lesion. Imaging-guided steroid injections are now becoming more popular despite the controversy regarding their efficacy. Many reports, including a few randomized controlled trials, have documented the clinical utility of epidural steroid injections

369

Manipulation of primary sex ratio in birds: lessons from the homing pigeon (Columba livia domestica).  

Science.gov (United States)

Across various animal taxa not only the secondary sex ratio but also the primary sex ratio (at conception) shows significant deviations from the expected equal proportions of sons and daughters. Birds are especially intriguing to study this phenomenon as avian females are the heterogametic sex (ZW); therefore sex determination might be under direct control of the mother. Avian sex ratios vary in relation to environmental or maternal condition, which can also affect the production of maternal steroids that in turn are involved in reproduction and accumulate in the developing follicle before meiosis. As the proximate mechanisms underlying biased primary sex ratio are largely elusive, we explored how, and to what extent, maternal steroid hormones may be involved in affecting primary or secondary sex ratio in clutches of various species of pigeons. First we demonstrated a clear case of seasonal change in sex ratio in first eggs both in the Rock Pigeon (Columba livia) and in a related species, the Wood Pigeon (Columba palumbus), both producing clutches of two eggs. In the Homing Pigeon (Columba livia domestica), domesticated from the Rock Pigeon, testosterone treatment of breeding females induced a clear male bias, while corticosterone induced a female bias in first eggs and we argue that this is in line with sex allocation theory. We next analyzed treatment effects on follicle formation, yolk mass, and yolk hormones, the latter both pre- and post-ovulatory, in order to test a diversity of potential mechanisms related to both primary and secondary sex ratio manipulation. We conclude that maternal plasma hormone levels may affect several pre-ovulatory mechanisms affecting primary sex ratio, whereas egg hormones are probably involved in secondary sex ratio manipulation only. PMID:23720529

Goerlich-Jansson, Vivian C; Müller, Martina S; Groothuis, Ton G G

2013-12-01

370

Segregation of steroid receptor coactivator-1 from steroid receptors in mammary epithelium  

OpenAIRE

Steroid receptor coactivator-1 (SRC-1) family members interact with steroid receptors, including estrogen receptor ? (ER?) and progesterone receptor (PR), to enhance ligand-dependent transcription. However, the expression of ER? and SRC-1 was found to be segregated in distinct subsets of cells within the epithelium of the estrogen-responsive rat mammary gland. This finding was in contrast to the finding for the stroma, where significant numbers of cells coexpressed ER? and SRC-1. Treatmen...

Shim, Woo-shin; Direnzo, James; Decaprio, James A.; Santen, Richard J.; Brown, Myles; Jeng, Meei-huey

1999-01-01

371

Olfactory sensitivity to steroid glucuronates in Mozambique tilapia suggests two distinct and specific receptors for pheromone detection.  

Science.gov (United States)

Cichlids offer an exciting opportunity to understand vertebrate speciation; chemical communication could be one of the drivers of African cichlid radiation. Chemical signals mediate key aspects in the lives of vertebrates and often are species specific. Dominant male Mozambique tilapia [Oreochromis mossambicus (Peters 1852)] release a sex pheromone, 5?-pregnan-3?,17?,20?-triol 3-glucuronate and its 20?-epimer, via their urine. The objective of this study was to assess the sensitivity, specificity and versatility of the olfactory system of O. mossambicus to other steroids and their conjugates using the electro-olfactogram. Oreochromis mossambicus was sensitive to several 3-glucuronidated steroids, but did not respond to prostaglandins, unconjugated steroids or 17- or 20-conjugated steroids. Stimulation of the olfactory epithelium with increasing concentrations (1 pmol l(-1) to 10 ?mol l(-1)) of 5?-pregnan-3?,17?,20?-triol 3-glucuronate, 5?-pregnan-3?,17?,20?-triol 3-glucuronate, 3?,17?-dihydroxy-5?-pregnan-20-one 3-glucuronate, etiocholanolone 3?-glucuronate and 17?-estradiol 3-glucuronate produced characteristic sigmoidal concentration-response curves. However, tilapia were most sensitive to 17?-estradiol-3-glucuronate, which also had the lowest apparent EC50 and maximal response amplitude. Cross-adaptation and binary mixture experiments suggested that 5?,3?-reduced pregnan- and androstan-3-glucuronates share (a) common olfactory receptor(s), whereas 17?-estradiol 3-glucuronate is detected via (a) distinct olfactory receptor(s). In conclusion, the Mozambique tilapia has evolved high olfactory sensitivity and specificity to 3-glucuronidated steroids through two distinct olfactory receptor types; one detecting a male sex pheromone and a second detecting 17?-estradiol 3-glucuronate, a putative female-derived signal. However, O. mossambicus differs markedly in its olfactory perception from the more recently derived East African cichlid Astatotilapia burtoni, suggesting that chemical communication could, indeed, be involved in speciation. PMID:25324342

Keller-Costa, Tina; Canário, Adelino V M; Hubbard, Peter C

2014-12-01

372

In vitro metabolism of androstenedione and identification of endogenous steroids in Helix aspersa  

International Nuclear Information System (INIS)

In vitro metabolism of androstenedione in gonads of juvenile and adult Helix aspersa has been investigated. The conversion of [3H]androstenedione into testosterone, 5 alpha-dihydrotestosterone, androsterone, and estriol was demonstrated. In juvenile animals testosterone (59.8%) is the major metabolite whereas in adult animals androsterone (18.8%) is. The following endogenous steroids have been identified by gas chromatography-mass spectrometry in adult gonads: androsterone, dehydroepiandrosterone, androstenedione, 3 alpha-androstanediol, estrone, estradiol-17 beta, and estriol. The levels of testosterone, 5 alpha-dihydrotestosterone, androstenedione, and progesterone have been measured by RIAs in gonads and hemolymph. Their levels vary with the physiological stage: the gonadal and circulating levels of testosterone decrease with the sexual maturation whereas the 5 alpha-dihydrotestosterone increases. These differences observed in metabolism and in level of steroids between the juvenile and the adult snails allow us to suppose that these steroids have a biological role

373

In vitro metabolism of androstenedione and identification of endogenous steroids in Helix aspersa  

Energy Technology Data Exchange (ETDEWEB)

In vitro metabolism of androstenedione in gonads of juvenile and adult Helix aspersa has been investigated. The conversion of (/sup 3/H)androstenedione into testosterone, 5 alpha-dihydrotestosterone, androsterone, and estriol was demonstrated. In juvenile animals testosterone (59.8%) is the major metabolite whereas in adult animals androsterone (18.8%) is. The following endogenous steroids have been identified by gas chromatography-mass spectrometry in adult gonads: androsterone, dehydroepiandrosterone, androstenedione, 3 alpha-androstanediol, estrone, estradiol-17 beta, and estriol. The levels of testosterone, 5 alpha-dihydrotestosterone, androstenedione, and progesterone have been measured by RIAs in gonads and hemolymph. Their levels vary with the physiological stage: the gonadal and circulating levels of testosterone decrease with the sexual maturation whereas the 5 alpha-dihydrotestosterone increases. These differences observed in metabolism and in level of steroids between the juvenile and the adult snails allow us to suppose that these steroids have a biological role.

Le Guellec, D.; Thiard, M.C.; Remy-Martin, J.P.; Deray, A.; Gomot, L.; Adessi, G.L.

1987-06-01

374

Functionalization of new PN ligands with steroids  

International Nuclear Information System (INIS)

Efforts are currently underway to radiolabel steroids for possible imaging and treatment of breast cancer. The authors are exploring the ligating properties of phosphorus hydrazides to anchor radionuclides of diagnostic and therapeutic use (e.g. 99mTc or 186Re/188Re) to estrogen and progesterone steroids which abound around breast tumor cells. The phenolic ring of estrone undergoes nucleophilic reaction with the pentavalent trichloro phosphorus sulfide (or oxide) in the presence of a weak base such as Et3N or pyridine. The chlorines were then substituted with hydrazine to produce the phosphorus attached steroid ligands in excellent yields. These ligands formed stable complexes with the metals at the open-quotes non-tracerclose quotes (Pd(II) and Re) and open-quotes tracerclose quotes (99mTc and 109Pd) levels. The alcohol functionalities as in 11-hydroxy progesterone and protected estradiol were also utilized with the use of a strong base LiN(SiMe3)2 and KH. Carbonyl containing steroid such as pregnenolone was directly added to a bishydrazido phosphine chelate by Schiff base coupling in a dean stark set-up. For estrone, which contains a hindered ketone, one hydrazone unit was first formed before the phosphorus chloride was introduced. C-O-P bond formation was also achieved from enolates of these ketones. By applying 2 eq of LDA or BuLi, ? C-P bonding was accomplished. Structures anP bonding was accomplished. Structures and reactivities of these phosphorus hydrazide bound steroids are discussed

375

Atrial pacing leads: the clinical contribution of steroid elution.  

Science.gov (United States)

Although the original atrial pacing leads were passive fixation and J shaped for right atrial appendage placement, the subsequent development of the active fixation screw-in lead found favor because of a perceived low incidence of lead dislodgment and a wider selection of atrial pacing sites. A bipolar atrial lead study was undertaken to compare the long-term atrial implant data in 215 patients. Study leads comprised one passive fixation, steroid-eluting lead (Medtronic CapSure SP, 119 patients) and three nonsteroid-eluting leads; two active fixation (Medtronic BISPING model 4058, 30 patients; and Telectronics ACCUFIX model 330-801, 44 patients) and one passive fixation (Telectronics ENCOR model 330-854, 22 patients). Bipolar atrial voltage stimulation thresholds and electrograms were measured using the Telectronics META DDDR immediately postimplantation, and at 1-, 3-, 6-, 12-, and 18-month follow-up. There were 135 males and the mean age 68 years. The incidence of lead dislodgment was 4% for active fixation and 2% for passive fixation. All nonsteroid leads showed a typical rise in stimulation threshold with the highest being the ACCUFIX followed by the BISPING and ENCOR. The steroid-eluting CapSure SP, however, demonstrated a flat response with 98% of leads at 18 months having a value < or = 1.3 volts allowing voltage programming to 2.5 volts (2:1 safety ratio). Telemeted electrograms showed no differences for all leads at all visits. For low voltage atrial pacing with a low incidence of dislodgment and satisfactory atrial sensing, the steroid-eluting passive fixation lead is superior to all nonsteroid-eluting leads. PMID:7491303

Mond, H G; Hua, W; Wang, C C

1995-09-01

376

Sex-Offender Tracking  

Science.gov (United States)

... Safety & Prevention Law Enforcement Training Victim & Family Support Sex Offender Tracking The primary goal of the National Center for Missing & Exploited Children ® ’s Sex Offender Tracking Team ® (SOTT) is to provide assistance ...

377

Practice Safer Sex  

Science.gov (United States)

... This information in Spanish ( en español ) Practice safer sex Related information Men's health Screening tests and vaccines ... Return to top More information on Practice safer sex Explore other publications and websites Addressing HIV, Other ...

378

Sex Differences in Obesity  

Science.gov (United States)

Fact Sheet: Sex Differences in Obesity Part 1: Definitions and Epidemiology Part 2: Effects of Life Stages and Metabolic Hormones Part ... ethnic divide exists for overall obesity and for sex differences in obesity. Among black people, 54.3% ...

379

Sex Education: Another View  

Science.gov (United States)

The mother of a 14-year-old mentally retarded boy comments on the viewpoints of Dr. Sol Gordon (a sex education columnist) regarding masturbation, questions on sex, marriage, and the parents' role. (SBH)

Hamilton, Jennifer

1977-01-01

380

Genetic variants of sex hormone-binding globulin and their biological consequences.  

Science.gov (United States)

Several hormonal and metabolic factors have been found to influence the production of sex hormone-binding globulin (SHBG). In addition, twin studies have suggested that genetic factors may also contribute to variation in SHBG levels. Given the clinical significance of SHBG in regulating bioavailable sex steroid hormones, a number of studies examined the potential association between polymorphisms of SHBG gene and serum SHBG levels as well as their possible contribution in the pathogenesis of common diseases. Thus, polymorphisms of SHBG, altering either the production or the metabolism of the protein, may represent part of the genetic background of sex steroid hormone activity in humans. There is considerable heterogeneity in the results of these studies indicating the multiplicity of the factors influencing SHBG variation. However, the weight of evidence suggests that some common genetic variants of SHBG may influence SHBG levels and in part contribute to the phenotypic expression of human diseases. PMID:19733622

Xita, Nectaria; Tsatsoulis, Agathocles

2010-03-01

381

Sex Education in Croatia  

OpenAIRE

Abstract This article explores the influence of the Catholic church on educational policy, more specifically on sex education, in Croatia. It explores tensions between secular and religious discourses regarding the introduction of a sex education programme supported by the Catholic church into Croatian schools. The presence of the Catholic doctrine in the educational system provided the basis for the introduction of sex education with a religious framework, namely the GROZD sex edu...

Bijelic?, Natas?a

2008-01-01

382

Sex-Dependent Gene Expression in Human Pluripotent Stem Cells  

Directory of Open Access Journals (Sweden)

Full Text Available Males and females have a variety of sexually dimorphic traits, most of which result from hormonal differences. However, differences between male and female embryos initiate very early in development, before hormonal influence begins, suggesting the presence of genetically driven sexual dimorphisms. By comparing the gene expression profiles of male and X-inactivated female human pluripotent stem cells, we detected Y-chromosome-driven effects. We discovered that the sex-determining gene SRY is expressed in human male pluripotent stem cells and is induced by reprogramming. In addition, we detected more than 200 differentially expressed autosomal genes in male and female embryonic stem cells. Some of these genes are involved in steroid metabolism pathways and lead to sex-dependent differentiation in response to the estrogen precursor estrone. Thus, we propose that the presence of the Y chromosome and specifically SRY may drive sex-specific differences in the growth and differentiation of pluripotent stem cells.

Daniel Ronen

2014-08-01

383

Sex ratio at birth in Croatia: update.  

Science.gov (United States)

There is strong evidence that the sex ratio at birth is partially determined by environmental and social factors. The modern change in those factors serves as an explanation for the secular decline in sex ratio at birth in most of the industrialized countries. This article is the reexamination of the results from my previous communication in which no trend in sex ratio at birth was established for the Croatian data from 1946 to 2007. The data for the years 2008 to 2011 were added, which didn't result with the detection of a significant change in sex ratio at birth by the regression analysis or by the Box-Jenkins time series analysis. Although the numerous factors associated with the decline in sex ratio at birth did occur during the studied period (e.g. increased exposure to the environmental pollution through food, air and water, the rise of the obesity and diabetes incidence, the economic crisis etc.), it appears that none of them made the measurable impact on sex ratio at birth. Also, the possible marginally significant decline in sex ratio at birth could be the result of a high sex ratio at birth immediately after the World War II. The results of this study caution against rapid generalization of the factors found to influence the sex ratio at birth in the epidemiological and clinical studies on the population level data. PMID:25144988

Pavi?, Dario

2014-06-01

384

Biochemistry and physiology of anabolic androgenic steroids doping.  

Science.gov (United States)

Anabolic Androgenic Steroids (AASs) are chemical and pharmacological derivatives of the male hormone testosterone which are widely used for increasing burst and sprinting activities in sports. Although AASs are thought to be transversal to the plurality of sports disciplines, they are principally misused by bodybuilders, weightlifters, shot, hammer, discus or javelin throwers, rugby and American football players as well as by swimmers and runners. AAS exert a kaleidoscope of effects on human biology, principally through the 5-?-reductase-mediated conversion into dihydrotestosterone, the aromatase-mediated conversion into female sex hormones, a competitive antagonism to the glucocorticoid receptors, the potential stimulation of erythropoietin secretion as well as psychoactive effects on the brain. The influence of AASs on physical performance is still undefined, since the large number of studies published so far have described discordant and often contradictory outcomes. Nevertheless, animal and human investigations support the hypothesis that the administration of AASs might increase lean body mass, muscle mass, and maximal voluntary strength especially in men, so that they would represent an appealing form of doping for increasing power capacity, sustaining intensive training periods and, last but not least, as a cosmetic muscle makeover. The aim of this article is to review the biochemistry, physiology and the ergogenic effects of AASs. PMID:21443514

Lippi, G; Franchini, M; Banfi, G

2011-05-01

385

Early steroid withdrawal in liver transplantation is safe and beneficial.  

Science.gov (United States)

This report reviews the literature and discusses steroid withdrawal after hepatic transplantation. Our experience with steroid withdrawal is highlighted. The hypothesis is that steroid withdrawal from liver transplant recipients is safe and beneficial. A review of the English literature yielded 16 reports with a total of 901 patients (749 adults and 152 children). Most reports were nonrandomized and uncontrolled. Only two reports were randomized, controlled trials; three reports featured early steroid withdrawal (uncontrolled trial and 0% versus 3% (early steroid withdrawal v control; P = NS) in one controlled trial. Patient and graft survival were not adversely affected. Steroid withdrawal was associated with reduced rates and better control of hypertension, reduced total cholesterol levels, reduced rate of posttransplantation diabetes mellitus, improved control of diabetes, and reduced rate of obesity. The aggregate experience with steroid withdrawal suggests it is safe, associated with improvement in several posttransplantation complications, and deserves broader clinical application. PMID:10431017

Everson, G T; Trouillot, T; Wachs, M; Bak, T; Steinberg, T; Kam, I; Shrestha, R; Stegall, M

1999-07-01

386

When Sex Is Painful  

Science.gov (United States)

How common is painful sex? Pain during intercourse is very common—nearly 3 out of 4 women have pain during intercourse at some time during ... a long-term problem. What causes pain during sex? Pain during sex may be a sign of ...

387

Making Healthy Decisions About Sex  

Science.gov (United States)

... For Teens: How to Make Healthy Decisions About Sex Article Body Before you decide to have sex ... alcohol or use drugs. Are You Ready for Sex? Sex can change your life and relationships. Having ...

388

Sex hormones and skeletal muscle weakness.  

Science.gov (United States)

Human ageing is accompanied with deterioration in endocrine functions the most notable and well characterized of which being the decrease in the production of sex hormones. Current research literature suggests that low sex hormone concentration may be among the key mechanism for sarcopenia and muscle weakness. Within the European large scale MYOAGE project, the role of sex hormones, estrogens and testosterone, in causing the aging-related loss of muscle mass and function was further investigated. Hormone replacement therapy (HRT) in women is shown to diminish age-associated muscle loss, loss in fast muscle function (power), and accumulation of fat in skeletal muscle. Further HRT raises the protein synthesis rate in skeletal muscle after resistance training, and has an anabolic effect upon connective tissue in both skeletal muscle and tendon, which influences matrix structure and mechanical properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal muscle. PMID:23636830

Sipilä, Sarianna; Narici, Marco; Kjaer, Michael; Pöllänen, Eija; Atkinson, Ross A; Hansen, Mette; Kovanen, Vuokko

2013-06-01

389

Sex hormones and skeletal muscle weakness  

DEFF Research Database (Denmark)

Human ageing is accompanied with deterioration in endocrine functions the most notable and well characterized of which being the decrease in the production of sex hormones. Current research literature suggests that low sex hormone concentration may be among the key mechanism for sarcopenia and muscle weakness. Within the European large scale MYOAGE project, the role of sex hormones, estrogens and testosterone, in causing the aging-related loss of muscle mass and function was further investigated. Hormone replacement therapy (HRT) in women is shown to diminish age-associated muscle loss, loss in fast muscle function (power), and accumulation of fat in skeletal muscle. Further HRT raises the protein synthesis rate in skeletal muscle after resistance training, and has an anabolic effect upon connective tissue in both skeletal muscle and tendon, which influences matrix structure and mechanical properties. HRT influences gene expression in e.g. cytoskeletal and cell-matrix proteins, has a stimulating effect upon IGF-I, and a role in IL-6 and adipokine regulation. Despite low circulating steroid-hormone level, postmenopausal women have a high local concentration of steroidogenic enzymes in skeletal muscle.

Sipilä, Sarianna; Narici, Marco

2013-01-01

390

Radioreceptor assay for evaluation of the plasma glucocorticoid activity of natural and synthetic steroids in man  

International Nuclear Information System (INIS)

An assay for plasma glucocorticoid activity has been developed using specific glucocorticoid receptors. Unlike other assays for cortisol and certain synthetic corticosteroids, this radioreceptor assay measures the glucocorticoid activity of all natural and synthetic steroids. Steroids extracted from as little as 0.05 ml of plasma are incubated with 3H-dexamethasone and cytosol receptors from cultured rat hepatoma cells. From 0.5 to 50 ng of cortisol are accurately detected. Glucocorticoid activities of adult plasmas determined by the assay correlate closely with corticoid levels obtained in the CBG-isotope and fluorometric assays. Other steroids are measured in proportion to both concentration and potency as glucocorticoids. Relative activities include: cortisol 100, dexamethasone 940, prednisolone 230, prednisone 3, estradiol 1 and androstenedione 1. A similar ranking of steroids was found using receptors from a human source (fetal lung). The assay has been useful in detecting glucocorticoid activity in unidentified medications and in measuring plasma glucocorticoid levels after administration of synthetic corticosteroids. (auth)

391

Steroid hormone receptors ER? and PR characterised by immunohistochemistry in the mare adrenal gland  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Sex steroid hormone receptors have been identified in the adrenal gland of rat, sheep and rhesus monkey, indicating a direct effect of sex steroids on adrenal gland function. Methods In the present study, immunohistochemistry using two different mouse monoclonal antibodies was employed to determine the presence of oestrogen receptor alpha (ERalpha and progesterone receptor (PR in the mare adrenal gland. Adrenal glands from intact (n = 5 and ovariectomised (OVX (n = 5 mares, as well as uterine tissue (n = 9, were collected after euthanasia. Three of the OVX mares were treated with a single intramuscular injection of oestradiol benzoate (2.5 mg 18 – 22 hours prior to euthanasia and tissue collection (OVX+Oe. Uterine tissue was used as a positive control and showed positive staining for both ERalpha and PR. Results ERalpha staining was detected in the adrenal zona glomerulosa, fasciculata and reticularis of all mare groups. Ovariectomy increased cortical ERalpha staining intensity. In OVX mares and one intact mare, positive ERalpha staining was also detected in adrenal medullary cells. PR staining of weak intensity was present in a low proportion of cells in the zona fasciculata and reticularis of all mare groups. Weak PR staining was also found in a high proportion of adrenal medullary cells. In contrast to staining in the adrenal cortex, which was always located within the cell nuclei, medullary staining for both ERalpha and PR was observed only in the cell cytoplasm. Conclusion The present results show the presence of ERalpha in the adrenal cortex, indicating oestradiol may have a direct effect on mare adrenal function. However, further studies are needed to confirm the presence of PR as staining in the present study was only weak and/or minor. Also, any possible effect of oestradiol treatment on the levels of steroid receptors cannot be determined by the present study, as treatment time was of a too short duration.

Kindahl Hans

2009-07-01

392

Endogenous sex hormones and endometrial cancer risk in women in the European Prospective Investigation into Cancer and Nutrition (EPIC).  

OpenAIRE

Epidemiological data show that reproductive and hormonal factors are involved in the etiology of endometrial cancer, but there is little data on the association with endogenous sex hormone levels. We analyzed the association between prediagnostic serum concentrations of sex steroids and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition using a nested case–control design of 247 incident endometrial cancer cases and 481 controls, matched on center, me...

Allen, Ne; Key, Tj; Dossus, L.; Rinaldi, S.; Cust, A.; Lukanova, A.; Peeters, Ph; Onland-moret, Nc; Lahmann, Ph; Berrino, F.; Panico, S.; Larran?aga, N.; Pera, G.; Tormo, Mj; Sa?nchez, Mj

2008-01-01

393

Pathways to ischemic neuronal cell death: are sex differences relevant?  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract We have known for some time that the epidemiology of human stroke is sexually dimorphic until late in life, well beyond the years of reproductive senescence and menopause. Now, a new concept is emerging: the mechanisms and outcome of cerebral ischemic injury are influenced strongly by biological sex as well as the availability of sex steroids to the brain. The principal mammalian estrogen (17 ? estradiol or E2 is neuroprotective in many types of brain injury and has been the major focus of investigation over the past several decades. However, it is becoming increasingly clear that although hormones are a major contributor to sex-specific outcomes, they do not fully account for sex-specific responses to cerebral ischemia. The purpose of this review is to highlight recent studies in cell culture and animal models that suggest that genetic sex determines experimental stroke outcome and that divergent cell death pathways are activated after an ischemic insult. These sex differences need to be identified if we are to develop efficacious neuroprotective agents for use in stroke patients.

McCullough Louise D

2008-06-01

394

Neuroactive steroids modulate crustacean locomotor activity.  

Science.gov (United States)

We examined the effects of neuroactive steroids known to modulate gamma-aminobutyric acid(A) (GABA)(A) receptor activity, on locomotor activity in a submerged circular open-field apparatus. Juvenile male lobsters, Homarus americanus, were treated with a single administration of an agonist, 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone, 3alpha,5alpha-TH PROG), an antagonist, pregnenolone sulfate (PREGS), or vehicle alone. 3alpha,5alpha-TH PROG treatment (125 and 250 microg) significantly reduced while PREGS significantly elevated locomotor activity in a dose-dependent manner similar to diazepam. PREGS increased locomotor activity at 30 and 60 microg, while diminishing such activity and altering locomotor patterns at 120 microg. These results suggest that neuroactive steroids may affect crustacean GABA receptors in a fashion similar to the GABA(A) type found in the vertebrates, and that they may be involved in the regulation of locomotor behavior. PMID:11684341

Snyder, M J; Peeke, H V

2001-11-01

395

Cytotoxic steroidal saponins from Agave sisalana.  

Science.gov (United States)

Two new steroidal saponins, 8 and 10, along with 7 known steroidal sapogenins and saponins (1-7) and a furostanol saponin (9) were isolated from Agave sisalana Perrine ex Engelm. The structures of these two new compounds were identified and characterized by 1D and 2D?NMR spectroscopy and mass spectrometry. In addition, acid hydrolysis and GC-FID were used to confirm the sugar moieties of 8 and 10. The cytotoxic effects of 1-10 on MCF-7, NCI-H460, and SF-268 cancer cells were evaluated, and among them, compound 10 proved to be the most cytotoxic with IC?? values of 1.2, 3.8, and 1.5 µM, respectively. PMID:21243587

Chen, Pi-Yu; Chen, Chin-Hui; Kuo, Ching-Chuan; Lee, Tzong-Huei; Kuo, Yueh-Hsiung; Lee, Ching-Kuo

2011-06-01

396

Determination of steroids in manure and soil  

DEFF Research Database (Denmark)

A genuine analytical method to determine native steroids (pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone, estrone, 17b-estradiol, and 17a-estradiol) and one anthropogenic steroid (ethynylestradiol) in environmental solid samples is presented. In summary, the sample preparation was systematically evaluated with testing different solvents and a suite of solid phase extraction materials. The optimized method utilizes the pressurized liquid extraction (PLE) technology with automated (integrated) clean-up combined with an additional off-line multi-step clean-up. The sample extracts were derivatized and analyzed utilizing a gas chromatography triple quadrupole mass spectrometry technology. This method is applicable on all types of environmental solid samples (e.g., biosolids, soils and sediments).

Hansen, Martin; Björklund, Bengt Erland

397

Heck reactions of steroidal alkenyl iodides.  

Science.gov (United States)

Heck reactions of some steroid derivatives possessing iodo-alkenyl moiety (17-iodo-androst-16-ene, 1, 17-iodo-4-aza-4-methyl-androst-16-en-3-one, 2, 17-iodo-4-aza-androst-16-en-3-one, 3) were carried out in the presence of palladium catalysts using various olefins (methyl acrylate, ethyl methacrylate, allyl alcohol and allyl acetate) as coupling partners. With methyl acrylate, a side reaction was observed: the coupling product underwent a Diels-Alder reaction with the excess of methyl acrylate resulting in a six-membered carbocyclic E-ring. Reaction conditions of the synthesis of the Heck-product were optimized. Although the coupling with allyl alcohol led to the formation of 21-formyl-16-pregnene derivatives, the synthesis of the corresponding steroidal unsaturated alcohol could be achieved only via hydrolysis of the coupling product of the alkenyl iodide with allyl acetate. PMID:9516719

Skoda-Földes, R; Bodnár, M; Kollár, L; Horváth, J; Tuba, Z

1998-02-01

398

Wired on steroids: Sexual differentiation of the brain and its role in the expression of sexual partner preferences  

Directory of Open Access Journals (Sweden)

Full Text Available The preference to seek out a sexual partner of the opposite sex is robust and ensures reproduction and survival of the species. Development of female-directed partner preference in the male is dependent on exposure of the developing brain to gonadal steroids synthesized during critical periods of sexual differentiation of the central nervous system. In the absence of androgen exposure, a male-directed partner preference develops. The development and expression of sexual partner preference has been extensively studied in rats, ferrets, and sheep model systems. From these models it is clear that gonadal testosterone, often through estrogenic metabolites, cause both masculinization and defeminization of behavior during critical periods of brain development. Changes in the steroid environment during these critical periods results in atypical sexual partner preference. In this manuscript, we review the major findings which support the hypothesis that the organizational actions of sex steroids are responsible for sexual differentiation of sexual partner preferences in select non-human species. We also explore how this information has helped to frame our understanding of the biological influences on human sexual orientation and gender identity.

BrendaMaeAlexander

2011-10-01

399

Better science with sex and gender: Facilitating the use of a sex and gender-based analysis in health research  

OpenAIRE

Abstract Much work has been done to promote sex and gender-based analyses in health research and to think critically about the influence of sex and gender on health behaviours and outcomes. However, despite this increased attention on sex and gender, there remain obstacles to effectively applying and measuring these concepts in health research. Some health researchers continue to ignore the concepts of sex and gender or incorrectly conflate their meanings. We report on a primer that was devel...

Greaves Lorraine; Johnson Joy L; Repta Robin

2009-01-01

400

"Bareback" pornography consumption and safe-sex intentions of men having sex with men.  

Science.gov (United States)

Men having sex with men (MSM) commonly consume "bareback" pornography, which includes scenes of unprotected anal intercourse. Prior research on human imitative behavior suggests that these media might counteract efforts to promote safe-sex behaviors. To date, no studies have demonstrated a causal link between bareback pornography consumption and reduced safe-sex intentions. Study 1 utilized a correlational design conducted as an online survey. Study 2 was set in an actual MSM sex club, using a 2 × 2 mixed-factorial design to compare type of pornography (unprotected vs. protected anal intercourse) and age of actors (younger vs. older). As the main dependent variable in both studies, participants self-reported their inclinations toward unprotected versus protected intercourse, using a 100-point sliding scale (1 = unprotected, 100 = protected). In Study 1, more attention to unprotected sex acts on actual DVD film covers predicted lower safe-sex intentions, as compared to other elements of the film cover. In Study 2, safe-sex intentions after viewing unprotected-sex films were lower than after viewing protected-sex films. The results provide novel and ecologically valid evidence that "bareback" pornography consumption impacts viewer's inclinations toward sexual risk-taking by lowering their intentions to use protected sex measures. Suggestions are given as to how these findings can be utilized for purposes of intervention and prevention of STI and HIV infections. PMID:24729135

Jonas, Kai J; Hawk, Skyler T; Vastenburg, Danny; de Groot, Peter

2014-05-01

401

Illicit Anabolic-Androgenic Steroid Use  

OpenAIRE

The anabolic-androgenic steroids (AAS) are a family of hormones that includes testosterone and its derivatives. These substances have been used by elite athletes since the 1950s, but they did not become widespread drugs of abuse in the general population until the 1980s. Thus, knowledge of the medical and behavioral effects of illicit AAS use is still evolving. Surveys suggest that many millions of boys and men, primarily in Western countries, have abused AAS to enhance athletic performance o...

Kanayama, Gen; Hudson, James I.; Pope, Harrison G.

2009-01-01

402

Limonoid and Steroidal Saponin from Azadirachta indica.  

Science.gov (United States)

A new limonoid, 17-(5-methoxy-2-oxofuran-3-yl)-28-deoxonimbolide (1), and a new C21 steroidal saponin, 2?,4?-dihydroxy-pregn-5-en-16-one-3?-O-D-glucopyranoside (2), together with 11 known compounds were isolated from the methanol extract of the leaves of Azadirachta indica. The structures were elucidated by means of spectroscopic analysis and putative biosynthetic origins. All the compounds were evaluated for their antibacterial activities against six bacterial strains. PMID:25381190

Liu, Lu; Zhao, Yun-Li; Cheng, Gui-Guang; Chen, Ying-Ying; Qin, Xu-Jie; Song, Chang-Wei; Yang, Xing-Wei; Liu, Ya-Ping; Luo, Xiao-Dong

2014-11-01

403

Two new steroidal glycosides from Cynanchum wallichii.  

Science.gov (United States)

Two new C21 steroidal glycosides were isolated from Cynanchum wallichii Wight. Their structures were elucidated as caudatin-3-O-?-d-glucopyranosyl-(1 ? 4)-?-d-oleandropyranosyl-(1 ? 4)-?-d-cymaropyranosyl-(1 ? 4)-?-d-digitoxopyranoside (1) and caudatin-3-O-?-d-glucopyranosyl-(1 ? 4)-?-d-cymaropyranosyl-(1 ? 4)-?-d-oleandropyranosyl-(1 ? 4)-?-d-cymaropyranosyl-(1 ? 4)-?-d-digitoxopyranoside (2) by spectroscopic methods including 1D and 2D NMR experiments. PMID:24786590

Wang, Ding; Pan, Wen-Hao; Bao, Yong-Rui; Yang, Xin-Xin; Meng, Xian-Sheng

2014-01-01

404

Anabolic steroid induced acute myocardial infarction.  

OpenAIRE

Androgenic anabolic steroids are commonly abused by athletes and body-builders to help develope lean body mass and muscular strength to enhance their performance. However, at doses which are much higher than recommended therapeutic dosage, abuse of these drugs is commonly associated with cardiovascular side-effects that can lead to acute myocardial infarction and sudden death. We report here three cases of acute myocardial infarction in local young bodybuilders who were using Stanazolol, an a...

Chong, Chee Fui

2011-01-01

405

Sorption of steroidal hormones by electrodialysis membranes  

OpenAIRE

The mechanisms of sorption of four steroidal hormones – estradiol, estrone, progesterone and testosterone – to electrodialysis (ED) membranes were investigated as a function of solution pH and presence of humic acid (HA). Hormone-membrane partition coefficients (log KAEM/CEM) determined t