Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    ISSN: 1432-0878
    Keywords: Key words: FSH ; Immunohistochemistry ; Receptor mRNA ; In situ hybridization ; Sertoli cell ; Testis ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Testicular biopsies from 82 oligo- or azoospermic male patients were subjected to immunostaining using anti-human FSH antibodies. Histological evaluation showed normal spermatogenesis (nspg) in 7 (FSH: 2.7±0.7), mixed atrophy (ma) in 63 (FSH: 5.3±0.5), and bilateral or unilateral Sertoli Cell Only syndrome (SCO) in 12 (FSH:21.7±3.5) patients. For the relationship between FSH values and testicular histology, see Bergmann et al. (1994). FSH immunoreactivity was found exclusively in Sertoli cells and in some interstitial cells. Seminiferous epithelium showing normal or impaired spermatogenesis displayed only weak immunoreactivity compared to intense immunoreaction, i.e. large and numerous vesicles in Sertoli cells of SCO tubules in biopsies showing mixed atrophy or SCO. In addition, h-FSH receptor mRNA was demonstrated by in situ hybridization using biotinylated cDNA antisense oligonucleotides. Hybridization signals were found within the seminiferous epithelium exclusively in Sertoli cell cytoplasm associated with normal spermatogenesis and in epithelia showing different signs of impairment, including SCO. It is concluded that: (1) Sertoli cells are the only cells within the seminiferous epithelium expressing FSH receptors; (2) the accumulation of FSH immunoreactivity in Sertoli cells of SCO tubules appears to be a sign of impaired Sertoli cell function.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 1432-0878
    Keywords: Key words: Spermatogenesis ; Testis ; Cell cycle ; Immunohistochemistry ; Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A comparatively low yield of germ cells has been reported for the spermatogenic process in primates. Kinetic studies of spermatogenesis and the spermatogenic cycle are needed to investigate this phenomenon but require the application of radioactively labeled compounds or irradiation. We have therefore investigated the suitability of a non-radioactive approach, viz., administration of 5-bromodeoxyuridine, for the determination of the kinetics of the spermatogenic cycle in a non-human primate, the rhesus monkey (Macaca mulatta). Four adult in-season animals received a bolus of 33 mg/kg 5-bromodeoxyuridine, one testis from each monkey was removed 3 h later and the other testis after 10 days and 11 h. Tissue was fixed in Bouin’s solution and embedded in Paraplast. 5-Bromodeoxyuridine was localized by immunogold-silver staining with a monoclonal antibody. PAS-hematoxylin counterstaining was used for spermatogenic stage identification. At 3 h, the leptotene and zygotene spermatocytes in stages VII–IX were the most advanced 5-bromodeoxyuridine-positive cells. At 10 days 11 h, the label had advanced and pachytene spermatocytes in stages VI–IX contained 5-bromodeoxyuridine. The duration of the spermatogenic cycle was 10.42±0.07 days (range: 10.25–10.62 days). Peritubular cells and interstitial cells were rarely 5-bromodeoxyuridine-positive, and Sertoli cells were consistently negative for 5-bromodeoxyuridine. Importantly, our kinetic data closely resemble those obtained by means of the application of irradiation for this macaque species. We conclude that administration of 5-bromodeoxyuridine represents a non-radioactive reliable approach for studying kinetic aspects of the spermatogenic process in primates.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 1432-0878
    Keywords: Inhibin ; LH ; FSH ; Pituitary gland, pars anterior ; Immunocytochemistry ; Maccaca fascicularis, Macaca mulatta (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Inhibin-like immunoreactivity was detected by immunocytochemistry in the pituitaries of untreated male crab-eating macaques (cynomolgus monkey) and rhesus monkeys, in rhesus monkeys actively immunized against FSH, and in one orchidectomized crab-cating macaque. Localizations were performed by the immunogold-silver staining with 5-nm colloidal gold-conjugated second or third antibodies and by the alkaline phosphatase-anti-alkaline-phosphatase technique. Two different inhibin-specific antisera, raised against the α-subunit or the entire inhibin molecule, provided identical staining patterns. Positive label was confined to the pars distalis of the pituitary and occurred exclusively in the cytoplasm of morphologically different cell types throughout the pars distalis in all pituitaries. Staining was most prominent in clusters of chromophobic cells. The presence of inhibin-like activity in the pituitary of an orchidectomized monkey with undetectable serum inhibin levels suggests that inhibin is produced within the pituitary gland. Co-localization studies for the β-subunits of the gonadotropic hormones revealed that on average 82% of the gonadotropes were bihormonal. Using the same protocol, co-localization of inhibin-like activity with gonadotropin-like immunoreactivity revealed only a small degree of common distribution (〈15%). Inhibinpositive cells were frequently in close proximity to gonadotropic cells and, thus, paracrine effects of inhibin on gonadotropin-synthesizing cells are conceivable.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    ISSN: 1432-0878
    Keywords: FSH ; Immunohistochemistry ; Receptor mRNA ; In situ hybridization ; Sertoli cell ; Testis ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Testicular biopsies from 82 oligo-or azoospermic male patients were subjected to immunostaining using anti-human FSH antibodies. Histological evaluation showed normal spermatogenesis (nspg) in 7 (FSH: 2.7±0.7), mixed atrophy (ma) in 63 (FSH:5.3±0.5), and bilateral or unilateral Sertoli Cell Only syndrome (SCO) in 12 (FSH:21.7±3.5) patients. For the relationship between FSH values and testicular histology, see Bergmann et al. (1994). FSH immunoreactivity was found exclusively in Sertoli cells and in some interstitial cells. Seminiferous epithelium showing normal or impaired spermatogenesis displayed only weak immunoreactivity compared to intense immunoreaction, i.e. large and numerous vesicles in Sertoli cells of SCO tubules in biopsies showing mixed atrophy or SCO. In addition, h-FSH receptor mRNA was demonstrated by in situ hydridization using biotinylated cDNA antisense oligonucleotides. Hybridization signals were found within the seminiferous epithelium exclusively in Sertoli cell cytoplasm associated with normal spermatogenesis and in epithelia showing different signs of impairment, including SCO. It is concluded that: (1) Sertoli cells are the only cells within the seminiferous epithelium expressing FSH receptors; (2) the accumulation of FSH immunoreactivity in Sertoli cells of SCO tubules appears to be a sign of impaired Sertoli cell function.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-0878
    Keywords: Inhibin ; Activin ; Testis ; Human ; Macaca fascicularis, Macaca mulatta, Macaca arctoides (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The localization and distribution of inhibin/activin subunits was evaluated in the testes of three nonhuman primate species (Macaca fascicularis, M. mulatta, M. arctoides), of young (31 to 43 years) and old (60 to 85 years) men, and of men with disturbed or arrested spermatogenesis using immunohistochemical techniques (peroxidase-anti-peroxidase and alkaline-phosphatase/ anti-alkaline-phosphatase technique). Specific polyclonal (anti-porcine inhibin α-1-32 and anti-bovine activin A) and monoclonal (anti-human inhibin α-1-32 and anti-human activin βA-82-114) antisera were employed. Among all nonhuman primate species and in men, inhibin/activin subunits were present in the cytoplasm of Sertoli cells and Leydig cells but not in germ cells. No relationship could be established between the staining pattern for inhibin/activin subunits and the completeness or the stage of the spermatogenic process. The staining for the βA-subunit in Sertoli cells appeared more intense in the testes of old men compared with that of young men. The majority of Leydig cells contained either the α-subunit and βA-subunit or the βA-subunit alone. The signal for the βA-subunit was remarkably intense in normal and hyperplastic human Leydig cells. These observations demonstrate the presence of inhibin/activin subunits in Sertoli cells and Leydig cells of adult primates and raise the possibility that these subunits or their respective dimers (inhibin A/activin A) might subserve a paracrine/ autocrine role in the adult primate testis. Also, the possibility of specific differences in the α-1-32 subunit and the βA-82-114 subunit region among certain primate species arises from the observation that the monoclonal antisera failed to detect the respective antigens in M. fascicularis and M. mulatta.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1573-7330
    Keywords: intrauterine insemination ; ovulation induction ; ultrasound-guided follicle puncture ; ovarian stimulation ; multiple pregnancy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: Our purpose was to demonstrate the feasibility of the routine aspiration of supernumerary follicles in infertile patients with imminent polyovulation after ovulation induction with gonadotropins and to examine its effect on the frequency of cycle cancellation and on the (multiple) pregnancy rate. Methods: The data on 796 treatment cycles, performed between 1989 and 1996 on 410 infertile couples, were analyzed retrospectively. From October 1992, whenever necessary, supernumerary ovarian follicles were selectively aspirated transvaginally under ultrasound guidance to prevent the ovulation of more than three follicles. Thereafter, intrauterine insemination was performed. Results: After the adoption of transvaginal ultrasound-guided aspiration of supernumerary follicles into the treatment protocol in October 1992, the number of canceled cycles (P 〈 0.0001) and the multiple pregnancy rate (P 〈 0.01) were significantly reduced compared to those previously. The overall pregnancy rate remained stable. No ovarian hyperstimulation syndrome requiring hospitalization was noted, and no complications resulting from the follicle aspiration were registered. Conclusions: Transvaginal ultrasound-guided aspiration of supernumerary ovarian follicles increases both the efficacy and the safety of ovulation induction with gonadotropins. Because of the limited equipment required, this method represents an alternative for conversion of overstimulated cycles to more costly alternatives such as in vitro fertilization.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1573-7330
    Keywords: catalase ; fertilization ; reactive oxygen species ; scavenging activity ; sperm function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: Reactive oxygen species (ROS) including H2O2 produced by spermatozoa have been suggested, on one hand, to be associated with idiopathic male infertility and, on the other hand, to stimulate certain sperm function leading to fertilization. The influence of ROS on fertilization was investigated in 75 IVF patients by correlating fertilization rates with the production of ROS and the H2O2-scavenging activity of swim-up spermatozoa prepared in parallel with the IVF samples. Results: Low rates of ROS production by the swim-up sperm was detected by the luminol-dependent chemiluminescence assay. They were not correlated with fertilization rates. The hydrogen peroxide scavenging capacity of these spermatozoa, measured as the removal of exogenous H2O2 assayed spectrophotometrically, decreased stepwise in groups of patients achieving higher fertilization rates, suggesting a positive effect of this ROS on fertilization. An alternative explanation of this correlation is plausible in view of the association of both high scavenging activities and poor fertilization rates with poor sperm morphology. Conclusions: ROS produced by spermatozoa selected by swim-up plays no negative, if not a positive, role in fertilization.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Biologie in unserer Zeit 21 (1991), S. 140-147 
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Die Hoden haben eine Doppelfunktion: Die Produktion von Hormonen, insbesondere die Synthese des Sexualhormons Testosteron, das für die Ausbildung und Aufrechterhaltung des männlichen Phänotyps verantwortlich ist, und die Produktion der Samenfäden, die für die Fortpflanzung notwendig sind. Die beiden Aufgaben werden zwar in morphologisch getrennten Kompartimenten des Hodens erfüllt, sind jedoch aufs engste miteinander verknüpft. Die Kenntnis der endokrinen Steuerung der Samenbildung (Spermatogenese) bildet die Voraussetzung für eine erfolgreiche Behandlung hormonell bedingter Störungen der Hodenfunktion und liefert Ansätze für Versuche zur männlichen Kontrazeption.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...