Potent inhibition of CD4/TCR-mediated T cell apoptosis by a CD4-binding glycoprotein secreted from breast tumor and seminal vesicle cells.
We previously isolated a CD4 ligand glycoprotein, gp17, from human seminal plasma; this glycoprotein is identical with gross cystic disease fluid protein-15 (GCDFP-15), a factor specifically secreted from primary and secondary breast tumors. The function of gp17/GCDFP-15 in physiological as well as in pathological conditions has remained elusive thus far. As a follow up to our previous findings that gp17 binds to CD4 with high affinity and interferes with both HIV-1 gp120 binding to CD4 and syncytium formation, we investigated whether gp17 could affect the T lymphocyte apoptosis induced by a separate ligation of CD4 and TCR. We show here that gp17/GCDFP-15 is in fact a strong and specific inhibitor of the T lymphocyte programmed cell death induced by CD4 cross-linking and subsequent TCR activation. The antiapoptotic effect observed in the presence of gp17 correlates with a moderate up-regulation of Bcl-2 expression in treated cells. The presence of gp17 also prevents the down-modulation of Bcl-2 expression in Bcl-2bright CD4+ T cells that is caused by the triggering of apoptosis. Our results suggest that gp17 may represent a new immunomodulatory CD4 binding factor playing a role in host defense against infections and tumors. (+info)
The novel analgesic compound OT-7100 (5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a]pyrimid ine) attenuates mechanical nociceptive responses in animal models of acute and peripheral neuropathic hyperalgesia.
We investigated the effects of OT-7100, a novel analgesic compound (5-n-butyl-7-(3,4,5-trimethoxybenzoylamino)pyrazolo[1,5-a]pyrimidi ne), on prostaglandin E2 biosynthesis in vitro, acute hyperalgesia induced by yeast and substance P in rats and hyperalgesia in rats with a chronic constriction injury to the sciatic nerve (Bennett model), which is a model for peripheral neuropathic pain. OT-7100 did not inhibit prostaglandin E2 biosynthesis at 10(-8)-10(-4) M. Single oral doses of 3 and 10 mg/kg OT-7100 were effective on the hyperalgesia induced by yeast. Single oral doses of 0.1, 0.3, 1 and 3 mg/kg OT-7100 were effective on the hyperalgesia induced by substance P in which indomethacin had no effect. Repeated oral administration of OT-7100 (10 and 30 mg/kg) was effective in normalizing the mechanical nociceptive threshold in the injured paw without affecting the nociceptive threshold in the uninjured paw in the Bennett model. Indomethacin had no effect in this model. While amitriptyline (10 and 30 mg/kg) and clonazepam (3 and 10 mg/kg) significantly normalized the nociceptive threshold in the injured paw, they also increased the nociceptive threshold in the uninjured paw. These results suggest that OT-7100 is a new type of analgesic with the effect of normalizing the nociceptive threshold in peripheral neuropathic hyperalgesia. (+info)
Testosterone control of nucleic acid content and proliferation of epithelium and stroma in rat seminal vesicles.
Tissue wet weight, nucleic acid content and epithelial and stromal cell numbers were measured in the seminal vesicles of sexually mature male rats. After castration, tissue weight and RNA decreased rapidly and in aprallel to reach, after 14 days, values only 15-20% of those in control (not castrated) animals. During this period, DNA decreased to a much lesser extent (by about 40%), but this change in DNA correlates well with the observed loss of cells from the epithelium. Testosterone in vivo promoted an immediate resynthesis of RNA, the value characteristic of control animals being reached within 80h. Delays occurred in the hormone-induced regain of tissue weight (30h) and DNA (40h), each of which preceded proliferation of the epithelium (40--50h). The cells of the stroma were unaffected by these changes in the androgenic statls of the animal. It is suggested that these proliferative changes in the epithelium cannot account for the previously reported induction by testosterone of basic secretory proteins in this tissue. (+info)
Seminal tract infections: impact on male fertility and treatment options.
Bacterial and viral infections of the genital tract may be important aetiological factors for male infertility. Infectious processes may lead to deterioration of spermatogenesis, impairment of sperm function and/or obstruction of the seminal tract. Detection of bacteria in semen does not necessarily signify infection since bacteriospermia may represent contamination, colonization or infection. Reported prevalence of Ureaplasma urealyticum in human semen varies from 10 to 40%. Enterobacteria can even be found in up to 90% of semen samples depending on the sensitivity of detection methods used. Chlamydia trachomatis is the most frequent sexually transmitted bacterial organism in industrialized countries. It is suggested that its main influence is due to sexual transmission resulting in tubal disease and subsequent infertility in the female partner rather than a direct influence on male reproductive functions. The effect of leukocytospermia on male fertility is controversial. This is probably due to different detection methods, different populations studied and to the fact that leukocyte subtypes in semen may have different functions. In addition to potentially negative effects, leukocytes may even have protective effects on spermatozoa. Only recently have amplification methods been established to detect viruses in semen with high sensitivity and specificity. It is unclear if these infections significantly contribute to male infertility. (+info)
Many LH peaks are needed to physiologically stimulate testosterone secretion: modulation by fasting and NPY.
The pulsatile luteinizing hormone (LH) and testosterone secretions were studied during serial blood collections performed at 7-min time intervals in the male rat. In fed rats, a discontinuous pattern of LH secretion was observed. Periods without secretion alternated with active secretory episodes consisting in trains of three to four LH peaks that triggered testosterone secretion usually 1-2 h later. The magnitude of the testosterone response was not correlated with the amplitude of the LH peaks. Isolated, single peaks of LH did not evoke clear testosterone responses. Forty-eight hours after initiation of fasting, testosterone secretion was markedly decreased, but integrated LH secretion was only partly reduced. Chronic infusion of neuropeptide Y (NPY; 18 microgram/day, icv) reduced testosterone secretion to very low levels and abolished pulsatile LH secretion or testosterone response to isolated LH peaks. In conclusion, the stimulation of testosterone secretion by LH necessitates several LH peaks organized in a proper sequence, and the testosterone response is not immediate. Low testosterone secretion in fasting rats appears to result from disappearance of coordinated, multiple LH peaks of sufficient size. Inhibition of the gonadotropic axis achieved by central NPY administration is due to either absence of LH peak "clusters" or occurrence of nonfunctional single LH peaks. (+info)
Comparison of the peroxidase reaction kinetics of prostaglandin H synthase-1 and -2.
Prostaglandin H synthase isoforms 1 and 2 (PGHS-1 and -2) each have a peroxidase activity and also a cyclooxygenase activity that requires initiation by hydroperoxide. The hydroperoxide initiator requirement for PGHS-2 cyclooxygenase is about 10-fold lower than for PGHS-1 cyclooxygenase, and this difference may contribute to the distinct control of cellular prostanoid synthesis by the two isoforms. We compared the kinetics of the initial peroxidase steps in PGHS-1 and -2 to quantify mechanistic differences between the isoforms that might contribute to the difference in cyclooxygenase initiation efficiency. The kinetics of formation of Intermediate I (an Fe(IV) species with a porphyrin free radical) and Intermediate II (an Fe(IV) species with a tyrosyl free radical, thought to be the crucial oxidant in cyclooxygenase catalysis) were monitored at 4 degrees c by stopped flow spectrophotometry with several hydroperoxides as substrate. With 15-hydroperoxyeicosatetraenoic acid, the rate constant for Intermediate I formation (k1) was 2.3 x 10(7) M-1 s-1 for PGHS-1 and 2.5 x 10(7) M-1 s-1 for PGHS-2, indicating that the isoforms have similar initial reactivity with this lipid hydroperoxide. For PGHS-1, the rate of conversion of Intermediate I to Intermediate II (k2) became the limiting factor when the hydroperoxide level was increased, indicating a rate constant of 10(2)-10(3) s-1 for the generation of the active cyclooxygenase species. For PGHS-2, however, the transition between Intermediates I and II was not rate-limiting even at the highest hydroperoxide concentrations tested, indicating that the k2 value for PGHS-2 was much greater than that for PGHS-1. Computer modelling predicted that faster formation of the active cyclooxygenase species (Intermediate II) or increased stability of the active species increases the resistance of the cyclooxygenase to inhibition by the intracellular hydroperoxide scavenger, glutathione peroxidase. Kinetic differences between the PGHS isoforms in forming or stabilizing the active cyclooxygenase species can thus contribute to the difference in the regulation of their cellular activities. (+info)
Significant changes in volume of seminal vesicles as determined by transrectal sonography in relation to age and benign prostatic hyperplasia.
We evaluated the changes in volume of the seminal vesicles as determined by transrectal sonography in terms of the possible relationship with aging, lower urinary tract symptoms and benign prostatic hyperplasia (BPH) in community based populations in Japan. In 641 men (55-86 year, mean 67) on a mass screening program for prostatic diseases, the maximum horizontal area of the seminal vesicles (MHA) was compared with age, American Urological Association (AUA) symptom index scores and transrectal ultrasonic parameters of the prostate including prostatic volume, transition zone (TZ) volume, TZ index and presumed circle area ratio (PCAR). Simple regression analyses demonstrated that MHA correlated significantly with age, prostatic volume, TZ volume, TZ index and PCAR, but not with AUA symptom index scores. Multiple regression analysis revealed age, prostatic volume and PCAR to be independent determinants of MHA. There was a difference in MHA between subjects with BPH (7.1+/-2.5 cm2) and those with a normal prostate (5.6+/-2.1 cm2) with a statistical significance. In the morphological evaluation of the seminal vesicles, the significant influence of age and BPH has to be taken into account. (+info)
Hyperplasia in multiple smooth muscle tissues in transgenic mice expressing a temperature-sensitive SV40 T-antigen under the control of smooth muscle alpha-actin regulatory sequences.
Control of smooth muscle cell (SMC) proliferation is of fundamental importance in the development and pathology of the vasculature. To derive vascular SMC with conditional inactivation of negative cell cycle regulatory proteins in the context of smooth muscle protein expression, a 3.4 kb fragment of the mouse SMC alpha-actin promoter was used to target a temperature-sensitive mutant SV40 T antigen (tsA58) to smooth muscle in transgenic mice. Mice with this genotype display a heritable phenotype of abnormal SMC proliferation in the central tail artery, vasa deferentia, seminal vesicles, prostate, and uterus, with the latter resembling uterine leiomyomatosis and prostatic hypertrophy. Neither the aorta nor other viscera manifested abnormal proliferation. Cultures from aorta, vas deferens, seminal vesicle, and kidney tissue were characterized with regard to protein expression, stability, and matrix remodelling capacity. The alpha-actin content/cell was up to 3-4-fold higher, as well as more stable than in primary SMC cultures, suggesting successful selection for propagation of cells expressing this differentiation marker. All cells displayed enhanced growth at the permissive temperature. As an initial functional assessment, the cells were compared to non-transformed mouse aortic SMC with respect to the ability to remodel collagen gel matrices, and demonstrated conservation of this physiologic function. This in vivo analysis of the SMC alpha-actin promoter supports a broader range of smooth muscle-directed expression activity than previously recognized, and establishes the feasibility of its use to direct transgene expression to vascular as well as genito-urinary smooth muscle. The targeted expression of the tsA58 T antigen has yielded transgenic animals with several manifestations of smooth muscle hyperplasia; these animals have in turn permitted the derivation of several murine SMC lines with phenotypic stability and conditionally-modulated proliferation. These cells will allow expansion of derivative transfected smooth muscle cell lines under permissive conditions, as well as oncogene inactivation at the restrictive temperature when desired for functional studies. (+info)