No description available.

1. Culture media and conditions were developed to maximize the sexual development of <I>Nannizzia incurvata</I> using liquid culture and solid media, modified Sabouraud's 1/6 salts + hair medium being the most suitable. 2. Strong evidence for the existence of two sex hormones which regulate sexual differentiation was found. It is proposed that these hormones are named (+)-factor (which is produced by (+)-cells and induce a sexual response in (-)-cells) and (-)-factor (which is produced by (-)-cells and induce a sexual response in (+)-cells). 3. Addition of active extracts of concentrated mated culture filtrates caused a switch from asexual to sexual development and the formation of the characteristic sexual cleistothecia. The hormones present are probably extracellular, as mycelial extracts do not cause this response. 4. Further evidence for the existence of these sex hormones was achieved by separation of compatible strains by a semi-permeable membrane, cellophane, which allowed diffusion of the hormones through the medium yet prevented physical, hyphal interactions between the two strains. Sexual morphogenesis occurred in both strains. 5. Both (+)-factor and (-)-factor were shown to be non-volatile by further experiments separating colonies with cellophane membranes. 6. (-)-Factor was solvent extractable using diethyl ether or ethyl acetate, while (+)-factor remained in the aqueous phase. Thus, (-)-factor is more hydrophobic yet less polar and (+)-factor is more hydrophilic yet more polar.

No description available.

Seven field experiments and two in-vitro studies were performed to elucidate hormonal control of staminate flowering in gynoecious and monoecious buffalo gourd (Cucurbita foetidissima HBK.) sex types. Objectives included development of techniques effecting staminate induction on gynoecious phenotypes which normally produce abortive stamenless male buds. Natural and synthetic growth regulants shown to modify sex expression in other cucurbits were surveyed for their masculinizing potential. Several compounds exogenously-applied to apical meristems elicited changes in shoot morphology. However, only aminoethoxyvinylglycine (AVG, an ethylene synthesis inhibitor) effected staminate induction on gynoecious segregates. Growth rate, patterns of female flowering or ontogeny of stamenless buds differentiated prior to treatment were not influenced by AVG. AVG was applied at various dosages (0-500 ppm) and produced male buds on all replicates treated at levels of 125 ppm or higher. The mean number of staminate buds induced varied linearly with dosage and averaged from 0-7.5 male flowers/shoot. A control model for staminate induction mediated by endogenous ethylene was advanced and potential benefits of this phenomenon to breeding efforts and/or to hybrid seed production were discussed. Ethephon (an ethylene releasing compound) was applied at various dosages to monoecious plants in anticipation of simulating the gynoecious phenotype. Although morphological changes were evident (i.e. reduction in shoot growth rate and floral initiation, increase in floral bud abortion and tissue senescence), ethephon failed to reduce staminate flowering or increase differentiation of antherless buds as expected. Dosage levels employed and/or confounding environmental factors may have contributed to the lack of staminate inhibition. During in-vitro studies, indirect evidence for ethylene-mediated control of male flowering was obtained by staminate proliferation in buds of gynoecious explants treated with silver nitrate (an inhibitor of ethylene action) and by formation of stamenless buds on monoecious explants treated with ethephon. However, low levels of floral induction under culture conditions employed rendered these results inconclusive. An incidental study of segregation ratios among AVG-facilitated self- and cross-pollination progeny upheld the supposition for monogenic inheritance of gynoecy in buffalo gourd.

The neuropeptides galanin and neuropeptide Y (NPY) play an important role in the reproduction of rodents, e.g. by modulating the release of gonadal hormones, the nutritional status by effects on feeding behavior and also by influencing mating behavior. There are age- and gender- differences in galanin- and NPY- like immunoreactivities (LIs) in brain areas important for higher functions including the hippocampal formation (HiFo) and cortex, that are related to the concentrations of 17β-estradiol. Neuropeptides in general are currently not considered critical in normal integrative neuronal functions but are rather thought to act as slow modulators during periods of stress or injury. In the present thesis we attempted to investigate, if the normal cyclical changes in the female sex-hormone 17β-estradiol can affect neurotransmission in brain areas important for memory, cognition and mood. We studied not only ”long term” (days and weeks) but also ”short-term” (one hour) effects on galanin and NPY concentrations in 17β-estradiol-primed ovariectomized (ovx) rats and mice. Radioimmunoassay (RIA) of galanin-LI in extracts of brain tissues from ”long-term” 17β-estradiol-treated ovx rats showed that its effects on galanin are dependent on boththe dose and on duration. Galanin - and NPY-LI in brain tissues of young ovx rats and mice increased in response to 17β-estradiol treatment in the HiFo, frontal cortex and striatum already within hours. This effect was not blocked by Tamoxifen® in rats. The mechanism of the 17β-estradiol effects on galanin levels in the rat HiFo may be related to decreased release of galanin into the extracellular fluid, since galanin-LI decreased in microdialysis samples two hours after a single injection of 17β-estradiol. Species differences were observed with regards to galanin, possibly due to tissue and species differences in the distribution of estrogen receptors. In the HiFo and caudate nucleus of mice, we found an increase in NPY-transcript after two hours by means of insitu hybridization, perhaps a compensatory up-regulation of NPY mRNA after increased 17β-estradiol-induced release in these areas. Taken together with no effects of Tamoxifen® on the levels on galanin in the HiFo of rats, the short duration, and the fact that the density of classical estrogen receptors seems to be limited in the striatum, we suggest that these effects are mediated through a membrane-related mechanism perhaps not involving the classical ER route. With an antiserum raised against the C-terminal end of the first 16 aminoacids of galanin- the sequence important for binding of intact galanin to its receptor - we found a novel compound which appears to be a homologue to galanin. Chromatographical analysis revealed that it was not galanin(1-29) or the galanin related peptide, galaninlike peptide (GALP), but appeared with immunohistochemistry in the galanin systems in the brain and was further influenced by 17β-estradiol in the HiFo and frontal cortex in a similar manner as galanin(1-29). In conclusion, tissue concentrations of galanin, a putative galanin homologue and NPY can be altered already after one hour by 17β-estradiol treatment e.i. in the HiFo. These ”short-term” effects are most likely to be due to effects on estrogen-primed peptide release which might influence mechanisms important for memory, cognition and mood.

Background: In 2007, the International Agency for Research on Cancer classified shift-work involving circadian disruption as a “probable carcinogen.” One proposed pathway for this relationship involves nighttime light exposure and subsequent decreases in melatonin production. It is postulated that melatonin, a cancer-protective hormone, may influence patterns of sex hormone production that in turn influence breast cancer risk. The purpose of this study was to investigate the relationships between night shift-work history, melatonin and sex hormone levels among shift-working women. Methods: 82 pre-menopausal nurses who work a rotating shift pattern of two days (7AM-7PM), two nights (7PM-7AM), followed by five days off participated in two study periods approximately six months apart (in summer and winter), each taking place during a day shift of the normal rotating shift pattern. Creatinine-adjusted melatonin metabolite concentrations were measured from morning void urine samples, and estradiol, estrone, progesterone and prolactin concentrations were measured from fasting blood samples taken at the same time. Other pertinent information was collected by measurement (weight, height) and by self-report via questionnaire. We examined melatonin-sex hormone relationships within each of two seasons, and across seasons, to investigate two hypothesized latency periods for influences of melatonin levels on sex hormones. Multivariate linear regression was used to explore relationships, with adjustment for confounders including age and body mass index. Results: An inverse relationship between melatonin and estradiol was suggested in winter (β = -0.13, p = 0.11), and a positive relationship was suggested for increasing estrone with increasing melatonin tertile in summer (p = 0.07), after multivariate adjustments. Melatonin was not associated with other hormones in either season. On investigation of a longer latency period, melatonin in the first season was not associated with sex hormones in the second season. While those working night shifts for 20 years or more had higher mean levels of estradiol, estrone and progesterone, results were not statistically different from those with a shorter history of night work. Conclusions: The results of this study do not provide evidence to support the proposed biological pathway involving altered melatonin and sex hormone levels as intermediates between shift-work and breast cancer risk. / Thesis (Master, Community Health & Epidemiology) -- Queen's University, 2010-09-14 11:42:06.201

1,2-Dibromo-4-(1,2 dibromoethyl)cyclohexane or tetrabromoethylcyclohexane (TBECH) is an additive bromine based flame retardant used primarily in expandable polystyrene beads that are used mainly to produce thermal insulation for housing. Secondary uses include extrusion into polystyrene foam, adhesive in fabric and vinyl lamination, electrical cable coatings and construction materials. The technical formulation contains two diastereoisomers, α- and β-, which are present in equimolar amounts. Under elevated temperatures two other isomers, γ- and δ-, can be formed. The recent detection of TBECH in the environment and suggestions that all four isomers are androgenic prompted me to examine the bioaccumulation and biochemical effects of one of the isomers, β-, in a controlled laboratory environment. I purposely chose to examine this isomer as it has been detected in biota. Juvenile brown trout (Salmo trutta) were exposed to three different amounts of the β-isomer via their to three different amounts of the β-isomer via their food for 56 days (uptake phase). This was followed by a depuration phase in which all fish were exposed to unfortified food for 77 days. A fourth group of fish were exposed to unfortified food for the duration of the experiment. On days 0, 7, 14, 35, 49, 56, 63, 77, 91, 105, and 133 eight fish from each treatment group were sacrificed and liver, plasma, thyroid and gonad gland were collected and whole-fish (carcass minus tissues above) were collected. Residues of β-isomer were analyzed in the whole-fish and in liver extracts by gas chromatography mass spectrometry in the electron ionization while estradiol (E2), 11-ketotestosterone (11-KT) and testosterone (T) were extracted from plasma and analysed by liquid chromatography tandem mass spectrometry. The bioaccumulation of β-isomer was similar in fish from all treatment groups with steady-state occurring before the end of the uptake phase. Depuration of the β-isomer from fish obeyed first order kinetics and there were no statistically significant differences in the depuration half life (t1/2) among the treatment groups: 22.5 ± 10.4 (low), 13.5 ± 5.9 (med) and 13.8 ± 2.2 (high) days. Steady-state biomagnification factors were much smaller than 1 for fish in all treatment groups. I was unable to detect debrominated metabolites in liver or whole-fish extracts and I also found no evidence of isomerization of the β-isomer to other isoforms in vivo. While there were some differences in E2, T and 11-KT levels in plasma of fish from the treated groups relative to plasma in fish from the control group there were no clear, consistent, discerning trends.

1,2-Dibromo-4-(1,2 dibromoethyl)cyclohexane or tetrabromoethylcyclohexane (TBECH) is an additive bromine based flame retardant used primarily in expandable polystyrene beads that are used mainly to produce thermal insulation for housing. Secondary uses include extrusion into polystyrene foam, adhesive in fabric and vinyl lamination, electrical cable coatings and construction materials. The technical formulation contains two diastereoisomers, α- and β-, which are present in equimolar amounts. Under elevated temperatures two other isomers, γ- and δ-, can be formed. The recent detection of TBECH in the environment and suggestions that all four isomers are androgenic prompted me to examine the bioaccumulation and biochemical effects of one of the isomers, β-, in a controlled laboratory environment. I purposely chose to examine this isomer as it has been detected in biota. Juvenile brown trout (Salmo trutta) were exposed to three different amounts of the β-isomer via their to three different amounts of the β-isomer via their food for 56 days (uptake phase). This was followed by a depuration phase in which all fish were exposed to unfortified food for 77 days. A fourth group of fish were exposed to unfortified food for the duration of the experiment. On days 0, 7, 14, 35, 49, 56, 63, 77, 91, 105, and 133 eight fish from each treatment group were sacrificed and liver, plasma, thyroid and gonad gland were collected and whole-fish (carcass minus tissues above) were collected. Residues of β-isomer were analyzed in the whole-fish and in liver extracts by gas chromatography mass spectrometry in the electron ionization while estradiol (E2), 11-ketotestosterone (11-KT) and testosterone (T) were extracted from plasma and analysed by liquid chromatography tandem mass spectrometry. The bioaccumulation of β-isomer was similar in fish from all treatment groups with steady-state occurring before the end of the uptake phase. Depuration of the β-isomer from fish obeyed first order kinetics and there were no statistically significant differences in the depuration half life (t1/2) among the treatment groups: 22.5 ± 10.4 (low), 13.5 ± 5.9 (med) and 13.8 ± 2.2 (high) days. Steady-state biomagnification factors were much smaller than 1 for fish in all treatment groups. I was unable to detect debrominated metabolites in liver or whole-fish extracts and I also found no evidence of isomerization of the β-isomer to other isoforms in vivo. While there were some differences in E2, T and 11-KT levels in plasma of fish from the treated groups relative to plasma in fish from the control group there were no clear, consistent, discerning trends.

Transmissible diseases are re-emerging as a global problem, with Sexually Transmitted Diseases (STDs) becoming endemic. Chlamydia trachomatis is the leading cause of bacterially-acquired STD worldwide, with the Australian cost of infection estimated at $90 - $160 million annually. Studies using animal models of genital tract Chlamydia infection suggested that the hormonal status of the genital tract epithelium at the time of exposure may influence the outcome of infection. Oral contraceptive use also increased the risk of contracting chlamydial infections compared to women not using contraception. Generally it was suggested that the outcome of chlamydial infection is determined in part by the hormonal status of the epithelium at the time of exposure. Using the human endolmetrial cell line ECC-1 this study investigated the effects of C. trachomatis serovar D infection, in conjunction with the female sex hormones, 17β-estradiol and progesterone, on chlamydial gene expression. While previous studies have examined the host response, this is the first study to examine C.trachomatis gene expression under different hormonal conditions. We have highlighted a basic model of C. trachomatis gene regulation in the presence of steroid hormones by identifying 60 genes that were regulated by addition of estradiol and/or progesterone. In addition, the third chapter of this thesis discussed and compared the significance of the current findings in the context of data from other research groups to improve our understanding of the molecular basis of chlamydial persistence under hormonal different conditions. In addition, this study analysed the effects of these female sex hormones and C. trachomatis Serovar D infection, on host susceptibility and bacterial growth. Our results clearly demonstrated that addition of steroid hormones not only had a great impact on the level of infectivity of epithelial cells with C.trachomatis serovar D, but also the morphology of chlamydial inclusions was affected by hormone supplementation.

Abstract Previous observations have indicated that reproductive endocrine disorders are common among patients with epilepsy. Valproate (VPA) treatment is associated with hyperandrogenism, polycystic ovaries, and obesity in women. Carbamazepine (CBZ) may also induce endocrine disorders, while the hormonal effects of oxcarbazepine (OXC) are poorly known. The aim of this study was to elucidate the effects of antiepileptic drugs on reproductive hormones, linear growth and pubertal maturation in patients with epilepsy. Altogether 223 patients taking VPA, CBZ, or OXC monotherapy for epilepsy and 103 healthy age- and sex-matched volunteers participated in the study. Seventy-eight girls and 90 men with epilepsy participated in the cross-sectional parts of the study. Thirty-nine adult patients with newly diagnosed epilepsy participated in a 3-month longitudinal study and VPA was replaced with lamotrigine (LTG) in 16 women with VPA-related endocrine disorders in a 1-year longitudinal study. The girls were between 8-18 years, the women 17-41 years and the men 17-51 years of age. None of the antiepileptic drugs studied significantly influenced linear growth or pubertal development in girls with epilepsy, but hyperandrogenemia, increased number of ovarian follicles, and weight gain were observed in prepubertal, pubertal and postpubertal girls taking VPA for epilepsy. Increased serum testosterone levels were observed in half of the women after the first 3 months of VPA medication, and high serum concentrations of androgens were common (prevalence 57 %, p &lt; 0.001) in men taking long-term VPA treatment. The women with VPA-related hyperandrogenism and polycystic ovaries were also found to present other features of insulin resistance (i.e. hyperinsulinemia, centripetal obesity, and an unfavorable serum lipid profile). Reproductive endocrine disorders associated with VPA treatment in women began to normalize after VPA was replaced by LTG. CBZ reduced the bioactivity of androgens, whereas OXC did not have similar effects. Serum concentrations of sex hormone-binding globulin (SHBG) were increased and dehydroepiandrosterone sulfate decreased already during the first months of CBZ treatment. Serum hormone levels were normal in patients with low OXC doses (&lt; 900 mg/d), but serum concentrations of testosterone, gonadotropins and SHBG were high in men with a daily OXC dose ≥ 900 mg. The adverse reproductive endocrine effects of antiepileptic drugs should be considered at the beginning of and during antiepileptic medication.