Gonadal structure (Total 2420781 Papers Found)

Ascorbic acid has long been associated with fertility, but no consistent study of its mechanism of action in reproductive tissues has been made. This article considers how three of ascorbic acid's principal functions, namely its promotion of collagen synthesis, its role in hormone production, and its ability to protect cells from free radicals, may explain its reproductive actions. Data relating to both ovary and testis are reviewed since ascorbate accumulates in both tissues. Both gonads exhibi ...
Gonadotropin releasing hormone-like immunoreactive (GnRH-ir) cells in both the ganglion of the terminal nerve (TN) and the preoptic area (POA) have been implicated in the development and maintenance of reproductive behavior and physiology in teleost fishes. One marine species, the plainfin midshipman, Porichthys notatus, exhibits two sexually mature male morphs (types I and II) which differ with respect to size at sexual maturation, gonad/body weight index, reproductive tactic and vocal motor tr ...
In the present study, both lamprey GnRH-I and -III stimulated steroidogenesis and induced ovulation in adult female sea lampreys during their final reproductive stage. One injection of lamprey GnRH-III at 0.1 or 0.2 microg/g lamprey stimulated plasma estradiol levels in lampreys held at each of three water temperatures, 13 degrees , 17 degrees , and 19 degrees , corresponding to increasing stages of maturation. Four successive injections, 3 to 4 days apart, of lamprey GnRH-III at 0.1 or 0.2 micr ...
Congenital adrenal hyperplasia (CAH) is one of the most common inherited metabolic disorders. It comprises a group of autosomal recessive disorders caused by the deficiency of one of four steroidogenic enzymes involved in cortisol biosynthesis or in the electron donor enzyme P450 oxidoreductase (POR) that serves as electron donor to steroidogenic cytochrome P450 (CYP) type II enzymes. The biochemical and clinical phenotype depends on the specific enzymatic defect and the impairment of specific e ...
The Wilms' tumor protein Wt1 plays an essential role in mammalian urogenital development. WT1 mutations in humans lead to a variety of disorders, including Wilms' tumor, a pediatric kidney cancer, as well as Frasier and Denys-Drash syndromes. Phenotypic anomalies in Denys-Drash syndrome include pseudohermaphroditism and sex reversal in extreme cases. We have used cDNA microarray analyses on Wt1 knockout mice to identify Wt1-dependent genes involved in sexual development. The gene most dramatical ...
Control of reproductive development in crustaceans requires neuropeptides, ecdysone and methyl farnesoate (MF). A major source of neuropeptides is the X-organ-sinus gland (XO-SG) complex located in the eyestalk ganglia of crustaceans. The other regulatory factors (either peptides or neuromodulators) are produced in the brain and thoracic ganglia (TG). Two other regulatory non-peptide compounds, the steroid ecdysone and the sesquiterpene MF, are produced by the Y-organs and the mandibular organs, ...
Introduction: In vitro environments expose developing oocytes to excess reactive oxygen species (ROS) which are not normally produced in vivo. Melatonin acts as an indirect antioxidant and is a powerful direct free radical scavenger and direct responses to melatonin in the gonads. This study aims to investigate the influence of different doses of melatonin on follicle development and oogenesis of in vitro cultured mouse ovarian follicles. Materials and Methods: Preantral follicles with diameters ...
Diseases such as avian influenza can destroy turkey flocks, potentially resulting in the loss of valuable or rare genetic material. Consequently, there is an urgent need to develop a means to archive such germplasm. Germline chimeras produced by intravascular transfer of primordial germ cells (PGC) have been reported in other avian species but not turkeys. This study examined the feasibility of both establishing an archive of frozen PGC, and producing germline chimeras by injecting the thawed ...
Although inhibin was first identified as a hormone regulating pituitary FSH secretion, it was later recognized to act as a tumor suppressor in the gonad and adrenal glands. Recently, the alpha subunit of this dimeric hormone (inhibin‑α) was reported to be involved in prostate tumorigenesis. To identify additional roles outside the reproductive axis, we investigated inhibin‑α gene activity and subsequent cell fate in human gastric cancer cells. The results were as follows: all the gastric c ...
Radiation exposure to the patient and urologist was determined during 60 procedures for percutaneous removal of calculi from the upper collecting system. For male patients the average radiation dose at the surface of the testis was 160 mrem (1.6 mSv.). Surface dose to the female patient at the ovary level averaged 580 mrem (5.8 mSv.). Radiation doses to the small field or region of fluoroscopy on the skin surface anterior to the kidney averaged 25 rem (0.25 Sv.). Radiation exposure to the urolog ...
Experiments performed on mouse fetal testes in vitro using electrophysiological techniques and intracellular injections of the fluorescent tracer disodium fluorescein showed that junctional transfer occurs between cells inside the seminiferous cords. This suggests a possible metabolic cooperation between testis cells at an early stage of gonad development. ...
CONTEXT The prevalence of phenotypic females with a 46,XY karyotype is low, thus current knowledge about age and clinical presentation at diagnosis is sparse even for the most frequent conditions, androgen insensitivity syndrome (AIS), and gonadal dysgenesis. OBJECTIVE To estimate incidence, prevalence, age at diagnosis, and clinical presentation at diagnosis in 46,XY females. DESIGN AND SETTING A nationwide study covering all known females with a 46,XY karyotype in Denmark since 1960. The d ...
Polyorchidism is an uncommon anomaly resulting from transverse division of the embryonic genital ridge. Up to 50 percent of cases are associated with cryptorchidism. The present case describes a 6-year-old boy who was referred for evaluation of an undescended right testicle. Examination revealed compensatory hypertrophy of the left testis (2 cm length; 2 cc volume; volume twice normal for age). These measurements were consistent with the presence of monorchidism rather than cryptorchidism. Lapar ...
Two male offspring of a healthy father in Galaz, a remote village in Northwest Iran, were noted to show severe asymmetric genu valgum, with 57 and 82 degrees angulation and dysplasia of the lateral femoral condyle, together with adaptive biomechanical changes of the ankle alignment. Three of the five male offspring of a second marriage who have reached puberty also show variable degrees of genu valgum, increasing with growth. The intermalleolar distance in the affected sons aged 16, 15, and 12 m ...
The Drosophila serendipity (sry) delta (6) zinc finger protein is a sequence-specific DNA binding protein, maternally inherited by the embryo and present in nuclei of transcriptionally active cells throughout fly development. We report here the isolation and characterization of four ethyl methanesulfate-induced zygotic lethal mutations of different strengths in the sry 6 gene. For the stronger allele, all of the lethality occurs during late embryogenesis or the first larval instar. In the cases ...
TAZ (G4.5) was initially identified as the gene associated with Barth syndrome and left ventricular noncompaction (LVNC). The purpose of this study was to investigate patients with LVNC for disease-causing mutations in TAZ. In 124 Japanese patients, including 50 families, mutation analysis of TAZ was performed using DNA sequencing. A splice donor mutation was identified in two brothers with Barth syndrome and LVNC, and a sister who was asymptomatic. However, the variant was not identified in eit ...
Sertoli cells are the most active cell population in the testis during infancy and childhood. In these periods of life, hypogonadism can only be evidenced without stimulation tests, if Sertoli cell function is assessed. AMH is a useful marker of prepubertal Sertoli cell activity and number. Serum AMH is high from fetal life until mid-puberty. Testicular AMH production increases in response to FSH and is potently inhibited by androgens. Serum AMH is undetectable in anorchidic patients. In primary ...
The results of these experiments has led us to conclude that light is a primary factor in inducing sexual activity in pheasants, quail and grouse, through the mediation of the hypophysis. Once this hypophysealgonad reaction is started it can not continue indefinitely with adequate light but only until the hypophysis falters in the production of the gonad-stimulating hormone through causes unknown. The immature pheasant resembles the adult at the close of the breeding season in that the gonads ar ...
The association of rare chromosomal rearrangements involving a specific 10q breakpoint with a single umbilical artery (SUA) and sex reversal has never been reported. This report describes the case of a fetus with prenatal ultrasound features of severe intrauterine growth retardation (IUGR), congenital heart disease, and SUA. Fetal blood study revealed de novo deletion of 10q25 and a 46,XY karyotype, while ultrasound demonstrated female genitalia. Based on these findings, sex reversal was diagnos ...
An immunoprecipitation assay was developed for measuring instantaneous reproductive effort in female American oysters, Crassostrea virginica. Oysters were injected with 14C-leucine and incubated in situ for 1 to 30 h periodically throughout the annual gametogenic cycle. Gonadal protein labeled with 14C-leucine was precipitated from an oyster homogenate with rabbit anti-oyster egg IgG as the primary antibody. Antibody-oyster egg protein complex was further purified by immunoadsorption with staphy ...
In this chapter we argue that reproductive science in its broadest sense has never been more important in terms of its value to conservation biology, which itself is a synthetic and multidisciplinary topic. Over recent years the place of reproductive science in wildlife conservation has developed massively across a wide and integrated range of cutting edge topics. We now have unprecedented insight into the way that environmental change affects basic reproductive functions such as ovulation, sper ...
We assessed the predictive value of anatomical findings and karyotype for establishing a diagnostic orientation in patients with disorders of sex development (DSD). We performed a retrospective chart analysis of 228 patients, grouped into 4 categories: 46,XX DSD, non-dysgenetic testicular DSD, dysgenetic testicular DSD and ovotesticular DSD. Degree of virilisation, presence of vagina, presence of palpable gonads, size of gonads and a plain karyotype was available for all cases. 46,XX DSD due to ...
OBJECTIVE To compare the effect of orchidectomy (ODX) in 7- and 24-week-old C57BL/6 mice on the age-related responses of the cytokine interleukin (IL)-1beta and its receptor to intraperitoneal injection of the bacterial endotoxin, lipopolysaccharide (LPS). METHODS We measured IL-1beta concentrations in the plasma, hippocampus, hypothalamus and adrenal gland using ELISA and iodine-125-labeled recombinant human IL-1alpha ([(125)I]IL-1alpha) binding in the hippocampus following the intraperitonea ...
The authors report a case of Turner's syndrome associated with Hashimoto's thyroiditis and present the various physiopathological hypotheses currently offered to explain the frequent association of an autoimmune pathology and a gonadal dysgenesis with an absence of X chromosome which is held responsible for autoimmunity. Is the chromosomal abnormality a factor predisposing to autoimmunity or does it result from a disturbance of the immune mechanism? Environmental factors, such as bacteria, virus ...
The genes encoding members of the wingless-related MMTV integration site (WNT) and fibroblast growth factor (FGF) families coordinate growth, morphogenesis, and differentiation in many fields of cells during development. In the mouse, Fgf9 and Wnt4 are expressed in gonads of both sexes prior to sex determination. Loss of Fgf9 leads to XY sex reversal, whereas loss of Wnt4 results in partial testis development in XX gonads. However, the relationship between these signals and the male sex-determin ...
The primary site of yolk protein synthesis in the nematode, Caenorhabditis elegans, has been determined. In animals containing no gonadal cells (obtained by laser ablation of the gonadal precursor cells early in development), yolk proteins are present in abundance. This demonstrates that yolk proteins are made outside the gonad. An examination of proteins present in tissues isolated by dissection, and a comparison of proteins synthesized by isolated tissues incubated in vitro have identified the ...
Anabolic steroids are drugs of abuse. However, the potential for addiction remains unclear. Testosterone induces conditioned place preference in rats and oral self-administration in hamsters. To determine if male rats and hamsters consume testosterone by intravenous (IV) or intracerebroventricular (ICV) self-administration. With each nose-poke in the active hole during daily 4-h tests in an operant conditioning chamber, gonad-intact adult rats and hamsters received 50 μg testosterone in an aqu ...
There is an increasing number of differences reported between the steroidogenesis pathways described in the traditional literature related to gonadal steroidogenesis and the more recent observations achieved using new technologies, especially molecular cloning, pangenomic expression studies, precise quantification of mRNA expression using real-time PCR, use of steroidogenic enzymes stably transfected in cells, detailed enzymatic activity analysis in cultured cell lines and mass spectrometry anal ...
Temperate zone birds terminate reproduction when they become photorefractory. In many species, refractoriness is "absolute" in that gonadal regression occurs before day length declines, and individuals are reproductively unresponsive even to continuous light. Based on studies of a few species, this form of refractoriness appears to be associated with a reduction (compared with breeding and/or photosensitive birds) in numbers of hypothalamic cells and fibers that are immunoreactive for gonadotrop ...
Gonadal steroid hormones, particularly testosterone (T) and related androgens, are important in the development and seasonal variation of sexually dimorphic organs. Other hormones, such as prolactin, have been found to be necessary in conjunction with gonadal steroids for the full structural development and function of some sex accessory structures (e.g., oviductal and cloacal gland secretions) and secondary sexual characteristics (e.g., genial glands and skin glands of newts). Thyroid hormones ...
Male golden hamsters were exposed to short photoperiod at either 20‡C or 5‡C. After 4 weeks a complete gonadal inhibition was observed in animals kept at 5‡C while in animals kept at 20‡C such an inhibition was much less. No significant difference in the pattern of pineal and plasma melatonin concentrations was observed between hamsters kept at 20‡C and 5‡C. If in the golden hamster pineal melatonin secretion is implicated in the transduction of the photoperiodic information, it is p ...
The myoepithelial sheath of the Caenorhabditis elegans somatic gonad has non-striated actomyosin networks that provide contractile forces during ovulation, a process in which a mature oocyte is expelled from the ovary. Troponin T and troponin C are known regulators of contraction of the myoepithelial sheath. These are two of the three components of the troponin complex that is generally considered as a striated-muscle-specific regulator of actomyosin contraction. Here, we report identification o ...
Two types of hermaphroditism were experimentally induced in genetically female fowls by grafting of embryonic testes in embryos. Of the 27 hermaphrodites observed during the 8 months after hatching, 20 possessed a right testis and a left ovary and 7 a right testis and a left ovotestis. The testes and ovotestes contained seminiferous tubules with a more or less developed germ cell complement, attaining in many cases the early spermatid stage. The interstitial tissue was poorly functional, as show ...
The objective of this study was to assess annual redox balance by quantifying activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST), as well as measuring lipid peroxidation levels by determination of thiobarbituric acid-reactive substances, in different tissues of male and female crayfish collected from an area little affected by anthropogenic impacts. A total of 37 male and 32 female of Parastacus brasiliensis promatensis were collec ...
A 409 bp full length defensin gene was cloned and sequenced based on an expressed sequence tag (EST) obtained from a normalized zebra mussel (Dreissena polymorpha) foot cDNA library developed in our laboratory. The D. polymorpha defensin (Dpd) gene encoded a peptide with 76 amino acid residues. The mature Dpd contains 54 amino acids with a fully functional insect defensin A domain. Homologue searching against GenBank database suggested that this Dpd was phylogenetically close to defensins from a ...
We examined the bioaccumulation of α- and β-endosulfan and endosulfan sulfate in tissues from the crab Zilchiopsis collastinensis. There was more endosulfan accumulated in the hepatopancreas (from <2 to 467.8 ng g(-1)) than in the gonads (from <2 to 52.1 ng g(-1)) or muscles (<2 ng g(-1)). The endosulfan concentrations in the hepatopancreas decreased over time and with the endosulfan dilution (p < 0.05). In the gonads there was little bioaccumulation, which did not vary over time ( ...
Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could ...
In this study, we investigated the effect of photoperiod on growth and gonadal development of juvenile topmouth gudgeon, Pseudorasbora parva. Seven different photoperiods (light:dark, L:D) were tested: 0L:24D, 4L:20D, 8L:16D, 12L:12D, 16L:8D, 20L:4D and 24L:0D, from November to January. Throughout the study, light intensity was kept at 400 lx on the water surface, and the fish were fed a commercial diet twice a day. Weight gain, feed intake, specific growth rate, and feed conversion efficiency ...
Monthly data collected during 1993 in the Vaccarès lagoon (Rhône Delta, France) were used to investigate the influence of the trematode Aphalloïdes coelomicola on the survival of the common goby Pomatoschistus microps, which acts both as second intermediate and definitive host. Prevalence of the parasite did not increase with fish size in either sex. Mean abundance and variance to mean abundance ratio gave evidence that the trematode could have an impact on host mortality. Gonad weight of par ...
To investigate whether toll like receptors (TLRs) genes do have an immune influence on noble scallop Chlamys nobilis under pathogen stress, acute challenges lasting 48 h to Vibrio parahaemolyticus, lipopolysaccharide (LPS), polyinosinic polycytidylic acid (Poly I:C), and PBS were conducted in two scallop stains of orange and brown with different carotenoids content. A novel toll-like receptor gene called CnTLR-1 was cloned and its transcripts under different challenges were determined. Meantime ...
Microscopic study of newborn female ovaries showed a constant and characteristic architectonic pattern on the surface area of the organ cortex. This pattern consisted of units that have been called "ovaric lobules" and that are made up of the various cellular types involved in the formation of the gonad (oocytes, cells derived from surface epithelium and connective-vascular elements). These structural units might be the site where synchronization or coordination for development and maturation of ...
OBJECTIVE Previous studies in mice have detected quantitative trait loci (QTLs) on chromosome 7 that affect body composition. As a step toward identifying the responsible genes, we compared a chromosome 7 substitution strain C57BL/6J-Chr7(129S1/SvImJ)/Na (CSS-7) to its host (C57BL/6J) strain. METHODS AND PROCEDURES Fourteen-week-old mice were measured for body size (weight, length), organ weight (brain, heart, liver, kidneys, and spleen), body and bone composition (fat and lean weight; bone ar ...
BACKGROUND Adolescents aged 15-19 years are variably included in analyses of childhood cancer. They should be considered separately because tumours that occur in adolescents differ from those in younger children. AIM To describe the distribution of tumour types and treatment results in this group of patients treated in the Department of Pediatric Oncology at The Children's Memorial Health Institute. METHODS Retrospective analysis of medical records of patients aged 15-19 years treated in our ...
The level of progesterone in blood serum and its concentration in adrenals and gonads have been assayed in male and female silver fox embryos, starting from day 35 of pregnancy for every five days. Pregnant females from an experimental population, selected for the domestic type of behavior and, as a control group, females from a commercial population, were used. At the end of prenatal development (days 45-50) the concentration of progesterone in adrenals was show to be significantly lower in emb ...
Primordial germ cells (PGCs) of Xenopus laevis have been isolated from early embryos and kept alive in vitro, in order to study the structural basis of their motility, using the transmission and scanning electron microscope. The culture conditions used mimicked as closely as possible the in vivo environment of migrating PGCs, in that isolated PGCs were seeded onto monolayers of amphibian mesentery cells. In these conditions we have demonstrated that: (a) No significant differences were found bet ...