[Current aspects in medicine of the locomotor system. Urticarial vasculitis: apropos of a case].
Explore the source record for details and available documents.
Adrenal Cortex Hormones↗
Biomedical subjects
P Franchimont
Publications and source records attributed to P Franchimont.
Variations of luteinizing hormone serum concentrations after exogenous human chorionic gonadotropin administration during ovarian hyperstimulation.
Changes in luteinizing hormone (LH), estradiol, and progesterone (P) serum levels before and after preovulatory administration of human chorionic gonadotropin (hCG) were assayed in 30 patients stimulated with clomiphene citrate (CC) and human menopausal gonadotropin (hMG) and compared with LH variations in 43 patients submitted to pharmacological hypophysectomy with a gonadotropin-releasing hormone agonist (GnRH-a) and stimulation with hMG. In CC + hMG-treated patients, an endogenous LH surge occurred systematically 4.25 +/- 2.75 hours after hCG injection. Multiparametric analysis indicated an inverse correlation between the delay in the initial rise of the LH surge and the increase in P levels during the 6 hours after hCG administration. Gonadotropin-releasing hormone agonist + hMG treatment did not lead to an LH surge after hCG but to a significant fall in LH levels. Thus, exogenous hCG, administered before ovulation, induces an endogenous LH surge if pituitary function is not blocked by a GnRH-a, probably through an increase in P secretion.
Adult↗
Effects of hormones and local growth factors on articular chondrocyte metabolism.
Human chondrocyte proliferation and production of matrix components such as proteoglycans and type II collagen (coll. II) were studied in an in vitro model of differentiated chondrocytes. It clearly appears that several hormones such as growth hormone, calcitonin, androgens and parahormones such as insulin like growth factor I and epidermal growth factor stimulate chondrocyte proliferation and coll. II and proteoglycan synthesis. These hormones and parahormones have no effect on either prostaglandin production or release and activation of collagenase. From our investigations in vitro, articular chondrocytes are target cells for hormones and local factors mainly responsible of chondroformation.
Aged↗
Placental alkaline phosphatase in developing normal and abnormal gonads and in germ-cell tumours.
The evolution of the gonads during intra-uterine development has been followed by immunohistochemical demonstration of placental-like alkaline phosphatase (PLAP) at the germ-cell level. PLAP immunopositivity was restricted to the limited period when germ cells were not surrounded by granulosa or Sertoli cells. Abnormal fetuses or neonates presenting with chromosomal anomalies frequently had disorganized gonads where germ cells retained their membrane PLAP immunopositivity. This abnormal immunopositivity is similar to that expressed by abnormal germ cells in testicular in situ carcinoma, in gonadoblastoma (case of 45,XO/46,XY mosaic) and in seminoma. The pattern of positivity for other germ-cell tumours was highly variable. We suggest that in abnormal gonads, dysgenetic or neoplastic, an early embryonic property is retained by abnormal germ cells. Its importance in the process of neoplastic induction remains to be defined.
Adolescent↗
Dual photon absorptiometry of lumbar spine in west European (Belgian) postmenopausal females: normal range and fracture threshold.
Bone mineral content (BMC) and bone mineral density (BMD) of lumbar spine have been measured in 695 healthy postmenopausal and 64 type I osteoporotic Belgian, Caucasian females. Bone loss is strongly correlated to time elapse from menopause (Tm) with a maximum rate of bone loss during the first five years of menopause. BMC (gHA) = 461 + 0.662 ln Tm -0.481 (ln Tm)2 and BMD (gHA/cm2) = 0.91 + 0.00711 ln Tm - 0.00846 (ln Tm)2 (in both cases p less than 0.001 and Tm expressed in months of menopause). After 20 years of menopause, 50 to 60% of normal women have vertebral BMC and BMD values below the 90th percentile of women with vertebral fractures and, thus, might be considered to have asymptomatic osteoporosis. We conclude that prevention of postmenopausal osteoporosis should be initiated as soon as possible after the onset of menopause and that bone density screening should be extended in elderly in order to detect and allow treatment of asymptomatic "densitometric" osteoporosis.
Absorptiometry, Photon↗
Evidence for a role of accessible galactosyl or mannosyl residues of Fc domain in the in vivo clearance of IgG antibody-coated autologous erythrocytes in the rat.
The potential role of accessible galactosyl or mannosyl residues of IgG in the clearance of IgG-coated autologous red blood cells (IgG-RBCs) by the spleen and the liver was investigated in the rat using rabbit anti-rat RBC IgG antibody molecules differing from each other by their capacity to bind in vitro to peanut agglutinin (PNA) and concanavalin A (Con A), i.e., two lectins that specifically bind to beta-galactosyl and alpha-mannosyl residues of Fc domain, respectively. Those IgG molecules [IgG(PNA) or IgG(Con A)] were separated from the starting anti-RBC IgG antibody batch [IgG(total)] by affinity chromatography on lectin columns. Each IgG-RBC preparation was labeled with 99mTc, and was reinjected iv with autologous rat RBCs labeled with 111In to correct for 99mTc present in the blood contained in each organ. The mean specific spleen uptakes per gram of the three IgG-RBC preparations increased according to the level of RBC sensitization but were at least 10 times higher in each instance than the mean specific liver uptake per gram. Consistent with the clearance curves of IgG(PNA)-RBCs, the mean specific splenic uptake per gram of those RBCs was significantly increased as compared to the same parameters determined using either IgG(total)-RBCs or IgG(Con A)-RBCs. In contrast, the mean specific liver uptakes per gram of IgG(PNA)-RBCs, of IgG(Con A)RBCs, or of IgG(total)-RBCs were not significantly different under otherwise identical experimental conditions. The increase in the splenic removal of IgG(PNA)-RBCs was C3 independent. Furthermore, splenic macrophages isolated from rats were able to bind in vitro significantly more IgG(PNA)-RBCs than IgG(total)-RBCs or IgG(Con A)-RBCs. These data therefore support the concept that, in the rat, the kinetic of removal of IgG-RBCs from the bloodstream by the Fc receptors of splenic mononuclear phagocytes may vary according to the nature of accessible carbohydrates located in the Fc domain of IgG antibody molecules coating the erythrocytes.
Animals↗
Calcitonin and postmenopausal bone loss.
In order to establish the role of calcitonin (CT) in postmenopausal bone loss, we studied CT metabolism in 25 pre- and postmenopausal women. Postmenopausal women presented a highly significant reduction of CT basal levels compared to premenopausal females (p less than 0.01). Also, production rates of CT in osteoporotics were significantly lower than in either young premenopausal (18-25 years old), older premenopausal (35-40 years old), or postmenopausal healthy subjects. In a study in rabbits, we found that injection of CT, along with equimolar amounts of anti-SCT antibodies extracted from serum of pagetic patients, did not inhibit the hypocalcemic response to the hormone, thus demonstrating that resistance to CT treatment cannot be accounted for by antibody production. In a subsequent clinical study in patients with Paget's disease of bone, we found that 200 IU/day of salmon CT (SCT), given by nasal spray, improved both clinically and biochemically the activity of the disease, as demonstrated by 37 +/- 4% decrease of serum alkaline phosphatase and 35 +/- 5% fall of urinary excretion of hydroxyproline after six months of therapy. The effectiveness of CT as nasal spray was further tested in healthy women at an early stage of menopause. A 12-month course of intranasal SCT counteracted early postmenopausal bone loss, presumably by inhibiting bone resorption. In conclusion, intranasal CT seems to be a very attractive alternative to be considered for the prevention of postmenopausal osteoporosis.
Administration, Intranasal↗
Radioimmunoassay for human type II collagen.
Human articular cartilage type II collagen (h coll.II) was purified and used to develop a radioimmunoassay. The sequential saturation procedure allowed a sensitivity of 3 ng/tube. The intra and between assay coefficients of variation were less than 10 and 20% respectively in the linear part of the curve. The assay was highly specific for native human articular type II collagen. There was no cross-reactivity with other constituents of cartilage: human proteoglycans, fibronectin, laminin and hyaluronic acid did not interfere with the assay. No cross-reactivity existed with bovine collagen types I, III, IV. However, native collagens from human placenta (I, III, IV, V, VI), rat and calf skin type I collagens and bovine type II collagen produced a weak cross-reaction only at high doses. Concerning the latter, inhibition curves were not parallel. Parallelism of inhibition curves were observed for dilution of type II collagen, produced by human chondrocytes in three-dimensional culture. All of these characteristics indicate that radioimmunoassy of type II collagen is a very sensitive and specific method available for the study and quantification of type II collagen in in vitro experimental conditions.
Cartilage, Articular↗
Correlation between follicular fluid content and the results of in vitro fertilization and embryo transfer. III. Proteoglycans.
Using a specific proteoglycan (PG) radioimmunoassay (RIA) in which human cartilage antiserum was directed against the PG protein core, the PG content of follicular fluid (FF) obtained from 42 women undergoing in vitro fertilization (IVF) and embryo transfer (ET) was studied as a function of IVF-ET outcome. Inhibition curves of purified PG cartilage preparations were parallel to those of large and small nonstimulated follicles and follicles that had been stimulated by a luteinizing hormone-releasing hormone (LHRH) agonist, d-tryptophan-6 (Decapeptyl: D-Trp6 analogue, Beaufour Laboratories, IPSEN Biotech, Paris, France), and human menopausal gonadotropin (hMG). While FF levels of immunoreactive PG-like material (Ir-PG) did not differ according to IVF-ET outcome, highly significant negative correlations were obtained between FF 17 beta-estradiol levels and FF Ir-PG levels in oocyte groups where pregnancy was obtained, i.e., oocytes were fertilized and cleaved, and pregnancy followed either for each ET or for one of two embryos reimplanted. The correlation persisted but weakened when all groups were pooled together. No correlation was observed between FF Ir-PG and progesterone. RIA or bioassay showed a positive correlation between FF inhibin and Ir-PG for the group in which each ET led to a pregnancy. Ir-PG concentrations were significantly greater in smaller than in larger follicles collected from untreated women. Upon induction of ovulation with either pure follicle-stimulating hormone (FSH), FSH + human chorionic gonadotropin (hCG), or D-Trp6/hMG + hCG, this difference no longer appeared. These results indicate that the reduction of Ir-PG concentrations constitutes an index of follicular maturation.(ABSTRACT TRUNCATED AT 250 WORDS)
Cartilage↗
In vivo cell activation following OKT3 administration. Systemic cytokine release and modulation by corticosteroids.
A massive and self-limited release of tumor necrosis factor and interferon gamma was detected in the systemic circulation in 35 consecutive renal allograft recipients by specific radioimmunoassays very soon following the first injection of the monoclonal antibody OKT3 (anti-CD3). Peak serum TNF and IFN gamma levels were reached, respectively, at 1 and 4 hr following the first OKT3 injection. Abnormally high serum interleukin 2 levels were also observed 4 hr following the first OKT3 injection in a minority of patients (5 cases). OKT3 had no effect on interleukin 1 beta, interferon alpha, and granulocyte/macrophage colony stimulating factor serum levels, which in all patients remained within the normal range throughout the study. This selective OKT3-induced cytokine release, which only followed the first injection, was transient (i.e., lasting a few hours). It tightly paralleled the spontaneously reversible clinical syndrome characterized by high fever, headaches, and gastrointestinal symptoms that is invariably associated with the first OKT3 administration. Importantly, when administered in adequate dosages and with adequate timing, corticosteroids influenced both the cytokine release and the systemic reaction. Thus, the highest TNF, IFN gamma, and IL-2 serum levels were detected in patients who did not receive corticosteroids. Patients who received high-dose corticosteroids (1 g solumedrol bolus) concomitantly with the first OKT3 injection still had high TNF and IFN gamma levels. Conversely, when the same corticosteroid dose was injected 15-60 min prior to the first OKT3 injection, in all cases the increase of serum TNF and IFN gamma was significantly lower as compared with the above-described groups; IL-2 levels did not rise. These data offer a direct explanation for one major side effect of OKT3 and thus provide the basis for devising means to prevent its occurrence.
Antibodies, Monoclonal↗
Epidermal growth factor and prolactin in human breast cyst fluid. Possible correlations with GCDFP-15.
Explore the source record for details and available documents.
Apolipoproteins↗
Maturation of the hypothalamic control of pulsatile gonadotropin-releasing hormone secretion at onset of puberty. I. Increased activation of N-methyl-D-aspartate receptors.
In the male rat the timing of puberty can be estimated by the rapid increase in testicular weight occurring between 25-50 days of age. We found that elongated spermatids, the most mature germ cells identified using flow cytometry, were first seen at 25 days (4% of the testicular cells), while an adult proportion (63%) was attained by 45 days of age. We have shown previously that hypothalamic explants could release GnRH in a pulsatile fashion at a frequency increasing around the age of 25 days, thus consistent with the time of onset of puberty. Since pulsatile GnRH secretion could be suppressed by MK-801, a noncompetitive antagonist of N-methyl-D-aspartate (NMDA) receptor activation, we postulated that an increased activation of those receptors could be involved in the neuroendocrine mechanism that activates pulsatile GnRH secretion at the onset of puberty. Such a concept was supported by the NMDA-induced release of GnRH, which was observed using 1 mM NMDA at 25 days, while a dose of 20-50 mM was required at 15 or 50 days of age. MK-801 could provide an index of NMDA receptor activation, since the antagonistic effect of MK-801 is use dependent. This particular property was confirmed by the inability of MK-801 (5 pM) to block the depolarization (veratridine)-induced release of GnRH in the presence of 0.001 mM NMDA, while partial or complete suppression was obtained in the presence of 0.1 and 10 mM NMDA, respectively. Using explants obtained at 5, 10, 15, 20, 25, 30, 35, and 50 days of age, the lowest concentrations of MK-801 that blocked the veratridine-induced release of GnRH were, respectively, 10(7), 10(7), 10(7), 10(3), 10, 10(2), 10(4), and 10(8) pM. In contrast, there was no age-related difference in sensitivity to the inhibitory effect of Mg2+, a noncompetitive NMDA receptor antagonist which is not use dependent. The pulsatile secretion of GnRH occurred at a similar frequency at 25 and 50 days of age (4.7 and 5.4 pulses/3.5 h, respectively) but it was suppressed by a lower MK-801 concentration at 25 days (10(4) pM) than at 50 days (10(8) pM). These data indicate that the NMDA receptors involved in the control of pulsatile GnRH secretion are markedly and transiently activated around the time of onset of puberty in the male rat.
Aging↗
Maturation of the hypothalamic control of pulsatile gonadotropin-releasing hormone secretion at onset of puberty: II. Reduced potency of an inhibitory autofeedback.
At the time of onset of puberty in the male rat, between 15 and 25 days of age, we have reported that pulsatile GnRH secretion by hypothalamic explants showed an increased frequency as indicated by the reduction of the mean interpulse interval from 66 to 40 min (P less than 0.05). This study aimed to evaluate whether these changes in GnRH secretion involved a self-regulatory mechanism. A 7.5-min exposure of explants obtained at 50 days to 0.1 microM superagonist D-TRP6-PRO9-N-Et-GnRH (GnRH-A) resulted in a delay of the next GnRH secretory pulse so that the mean interpulse interval increased from 35 to 67 min (P less than 0.001). In addition, after a 7.5-min exposure to GnRH-A, there was a 15-min period with absent or reduced release of GnRH in response to 50 microM veratridine, a depolarizing agent. A similar refractory period of 15 min was observed using explants obtained at 25 and 50 days whereas, at 15 days, the period of refractoriness lasted for 52.5 min. The inhibitory effect of GnRH-A on the subsequent response to veratridine occurred at similar concentrations of GnRH-A at the three studied ages and the inhibition was prevented using an antagonist of GnRH together with GnRH-A. The involvement of GnRH itself in an autofeedback mechanism was evaluated by studying the period of refractoriness separating two GnRH pulses elicited by 7.5-min exposures to veratridine. The initial responsiveness to veratridine was recovered after a refractory period of 52.5, 22.5, and 15 min when studied at 15, 25, and 50 days, respectively. While refractoriness occurred during repeated depolarization with K+ or veratridine, such an effect was not observed using N-methyl-D-aspartate (NMDA). During exposure to GnRH-A, the NMDA-induced release of GnRH was only reduced by 38% whereas veratridine-induced secretion showed a 94% reduction. Thus, exogenous activation of NMDA-sensitive receptors could bypass the inhibitory autofeedback. We conclude that: 1) pulsatile GnRH secretion is controlled by an inhibitory autofeedback involving NMDA sensitive receptors, 2) the increased frequency of pulsatile GnRH secretion at onset of puberty may be related to a reduced sensitivity of the hypothalamic pulse generator to an inhibitory autofeedback.
Animals↗
Correlation between follicular fluid content and the results of in vitro fertilization and embryo transfer. II. Inhibin and aromatase inhibitor activity.
The inhibin content and aromatase inhibitor activity (AIA) of 72 follicular fluids (FF) obtained from 42 women undergoing in vitro fertilization (IVF) and embryo transfer (ET) were studied as a function of IVF ET outcome. Inhibin levels were determined by bioassay (BA) and RIA; AIA was measured by BA. The inhibin content of follicles characterized as immature by their estradiol (E2) levels and E2/progesterone (P) ratios was significantly lower (P less than 0.05) than that of mature follicles (i.e. leading to pregnancy). The mean AIA for mature follicles were significantly lower than AIA in groups where pregnancy was not obtained. AIA for follicles from which a pregnancy was obtained for each ET was also significantly lower than that in FF characterized as immature of hypermature. The highest E2/AIA and inhibin BA/AIA ratios were associated with the highest incidence of successful IVF ET outcome. No correlation was found between AIA and inhibin, on the one hand, and E2, delta 4-androstenedione, E2/P, and PRL, on the other. However, a positive correlation was found between inhibin (RIA and BA) and P, reflecting the production of inhibin by granulosa cells during luteinization. These studies allowed us to conclude that FF inhibin levels do not differ according to IVF ET outcome, but are an index of follicular maturation. AIA not only constitutes an index of follicular maturation and granulosa cell luteinization, but is of predictive value for IVF ET outcome as E2/AIA and inhibin BA/AIA ratios.
Adult↗
Expression and processing of the activin-A/erythroid differentiation factor precursor: a member of the transforming growth factor-beta superfamily.
The biosynthesis and intracellular processing of the polypeptide precursor of the beta A-chain of the fertility hormone inhibin were assessed by infecting a wide spectrum of cell types with a recombinant vaccinia virus. Most cell lines, including follicular granulosa cells, secrete both prohormone and mature hormone as homodimers (activin) composed of disulfide-linked subunits of 54 kDa (proactivin-A) and 14 kDa (activin-A), respectively, and a small amount of prohormone-mature hormone heterodimers. Mature activin is secreted from mouse pituitary cells (AtT-20), while pig kidney cells [PK(15)] secrete mostly proactivin. More prohormone is secreted in the presence of NH4Cl, suggesting that prohormone processing is facilitated by low pH. Proactivin-A is not a ligand for the mannose-6-phosphate/insulin growth factor-II receptor. The recombinant activin stimulates FSH release from pituitary cells and differentiates erythroleukemia cell lines in vitro.
Acetylglucosaminidase↗
Expression of preprotachykinin-A and neuropeptide-Y messenger RNA in the thymus.
The preprotachykinin-A gene, the common gene of mRNAs encoding both substance-P (SP) and neurokinin-A (NKA), was shown to be expressed in Sprague-Dawley rat thymus by detection of specific mRNA in gel-blot analyses. In situ hybridization revealed dispersed PPT-A-labeled cells in sections from rat thymus, with a concentration of grains over a subpopulation of cells in the thymic medulla. Also, neuropeptide-Y mRNA-expressing cells were found in the rat thymus, primarily in the thymic medulla. Rat thymic extracts contained SP-like immunoreactivity (SP-LI), and the major part of the immunoreactivity coeluted with authentic SP and SP sulfoxide standards. SP-LI was also detected in human thymus, which contained between 0.09-0.88 ng SP-LI/g wet wt. Evidence for translation of preprotachykinin-A mRNA in the rat thymus was obtained from the demonstration of NKA-LI in thymic cells with an epithelial-like cell morphology. Combined with previous observations on the immunoregulatory roles of tachykinin peptides and the existence of specific receptors on immunocompetent cells, the demonstration of intrathymic synthesis of NKA suggests a role for NKA-LI peptides in T-cell differentiation in the thymus.
Animals↗
Influence of specific anti-salmon calcitonin antibodies on biological effectiveness of nasal salmon calcitonin in Paget's disease of bone.
Explore the source record for details and available documents.
Administration, Intranasal↗