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Biomedical subjects

P Franchimont

Publications and source records attributed to P Franchimont.

At least 199 records · Page 11Linked to original sources
PubMed1987

In vitro effects of thymopentin on the gamma-interferon production by peripheral blood mononuclear cells from normal subjects and from patients with rheumatoid arthritis.

The in vitro production of gamma-interferon (gamma-IFN) by peripheral blood mononuclear cells (MNC) was measured using a specific radioimmunoassay in 16 patients presenting with active rheumatoid arthritis (RA), in 14 patients with inactive disease, and in 36 control subjects (CS). Unstimulated cultures produced undetectable levels of gamma-IFN and did not incorporate tritiated thymidine. In response to phytohemagglutinin (PHA) 0.2 microgram/ml, MNC from active RA produced 9 times less, and under PHA 2.5 micrograms/ml, 4 times less gamma-IFN than did MNC from inactive RA or from CS. The uptake of tritiated thymidine was, however, similar in the 3 groups. In unstimulated cultures of the 3 groups, thymopentin (TP-5), at all concentrations tested, did not influence either the levels of gamma-IFN or the uptake of tritiated thymidine. In the presence of PHA 0.2 microgram/ml and TP-5, lambda-IFN levels were increased in CS, unchanged in inactive RA and reduced in active RA, whereas no changes were observed in the uptake of tritiated thymidine. Our results show that under our experimental conditions, TP-5 was able to increase the levels of gamma-IFN produced by normal MNC in vitro, but could not reverse the profound defect observed in active RA.

Adult↗
PubMed1987

[Detection of anti-DNA antibodies using I125-protein A].

Our purpose is to detect and dose anti-DNA antibodies in sera with analytical interferences in compatibility tests. This method seems with interest to clear transfusional reactions or incompatibilities in the laboratory tests. With 122 sera presenting a minor and isolated incompatibility with bromelin, we've found 21 positive results correlated or not (18/26) with the IF. The exposed methodology, simple, fast and reproducible seems to be a useful tool to resolve some transfusional situations.

Antibodies↗
PubMed1987

Bone mineral content and physical activity.

The purpose of this study was to estimate the effects of intense and regular physical activity on locomotor system modifications. Tennis, with its unilateral solicitations, allows a more precise examination of specific localized development. Ten professional tennis players were compared with sedentary age-matched students. Muscular modifications were observed, mainly in the forearm circumference. The dominant side forearm circumference was 13% larger than the opposite side. Asymmetry was less in the upper arm and insignificant in the thorax and vertebra. Deep modifications in bone mineral content (BMC) were investigated by isotopic techniques, based on differential photon attenuation in bone and soft tissue of the forearm. Bone density was markedly increased in professional tennis players. Even in the nondominant side, radius BMC was 1.18 g HA/cm, 15% higher than in sedentary control students. The difference was yet larger in the dominant mid-radius, reaching 1.47 g HA/cm. The same differences were observed for the ulna and involved both cortical and trabecular bone. In the control group of sedentary students, no significant difference was noted between the two upper limbs. This study clearly demonstrates the positive correlation between exercise and bone mineralization. The precise mechanical constraints optimizing the favorable effect in the most efficient way should be studied.

Adult↗
PubMed1987

Immunohistochemical demonstration of placental alkaline phosphatase in various states of testicular development and in germ cell tumours.

Immunohistochemical localization of placental alkaline phosphatase (PlAP) has been performed on eighty-two samples of normal (embryonic, fetal, infantile or adult), cryptorchid or tumorous testicular tissue. The isoenzyme could be demonstrated at the cell membrane of primitive, embryonic germ cells but not in other normal tissues. In-situ carcinomas and seminomas were positively stained in 93% and 94% of cases respectively. The percentage of positivity decreased with tumour differentiation. It is suggested that PlAP is a marker of primitive germ cells and that it reappears in germ cell neoplasms by gene derepression.

Alkaline Phosphatase↗
PubMed1987

Absence of anti-Müllerian activity of inhibin in the chick embryo.

Inhibin extracted from bovine follicular fluid and administered to chick embryos at a dosage increasing from 0.4 to 30 micrograms per embryo did not induce the regression of the Müllerian ducts of treated females. This result contrasts with that obtained with a testis graft which acts through its anti-Müllerian hormone. Although both hormones were of glycoproteic nature and secreted by the same cells, this study shows no functional analogy between them.

Animals↗
PubMed1987

Changes in fetal and maternal blood levels of prolactin, cortisol, and cortisone during eutocic and dystocic childbirth.

The changes in blood levels of prolactin, total and free cortisol, and cortisone were studied and compared in 51 mother-infant pairs, 30 with eutocic delivery and 21 with dystocic delivery. Regardless of the type of delivery, the newborn at term showed significantly higher prolactin and cortisone serum levels than their mothers, and significantly lower levels of free and total cortisol. In fetal distress of short duration, free cortisol levels were significantly raised in both the mother and the child, while prolactin and cortisone levels were significantly higher only in the child. In contrast to these observations, serum prolactin and cortisone levels in the mother were not altered by the occurrence of fetal distress. In the newborn at delivery there was a negative correlation between serum prolactin and the Apgar score at 1 min applied to the part of the graph between 8 and 2 Apgar scores. This study illustrates the utility of fetal prolactin measurements in evaluating the stress to which the fetus is subjected.

Adult↗
PubMed1987

Pulsatile release of gonadotropin-releasing hormone (GnRH) from the rat hypothalamus in vitro: calcium and glucose dependency and inhibition by superactive GnRH analogs.

We have shown previously that the rat hypothalamus retains in vitro its capacity of generating pulsatile release of GnRH. The present study evaluated if pulsatile release of GnRH in vitro was influenced by metabolic conditions (calcium and glucose availability) and the possible self-regulatory role of GnRH in its pulsatile secretion. In the presence of a calcium-chelating agent (EGTA, 20 mM) or a calcium-channel blocker (D-600, 0.1 mM), the release of GnRH induced by a depolarization (veratridine, 50 microM) was markedly and reversibly decreased. In addition, frequency and amplitude of GnRH secretory pulses were significantly reduced (P less than 0.05). When glucose use was inhibited using 2-deoxyglucose (5.6 mM) the release of GnRH induced by veratridine and the frequency of GnRH pulses were also blunted (P less than 0.05). Superactive agonists of GnRH (Buserelin and D-TRP6-PRO9-N-ET, 10 nM) caused a prompt decrease of GnRH release in basal conditions and in the presence of veratridine. A significant inhibition (P less than 0.05) was observed using buserelin concentrations greater than 0.01 nM, whereas two GnRH analogs without biopotency (Leu8-GnRH, Des-gly10-N picolylamide GnRH, 100 nM) did not affect GnRH release. The two agonists of GnRH reduced by 43% to 66% (P less than 0.05) the occurrence of significant GnRH pulses. We conclude that, in vitro, the hypothalamic neuronal circuitry resulting in GnRH pulsatile secretion is dependent on calcium and glucose availability and is sensitive to an ultrashort-loop inhibitory feedback mechanism.

Animals↗
PubMed1987

Primary role of glucagon release in the effect of beta-endorphin on glucose homeostasis in normal man.

The present study aimed at evaluating the effect of human beta-endorphin on pancreatic hormone levels and on glucose metabolism in normal subjects. Infusion of 143 nmol/h beta-endorphin in 7 subjects caused a significant rise in plasma glucose concentrations (+ 1.7 +/- 0.3 mmol/l) which was preceded by a significant increase in peripheral plasma glucagon levels (+ 44 +/- 13 ng/l). No changes occurred in the plasma concentrations of insulin and catecholamines (adrenaline and noradrenaline). The influence of beta-endorphin per se on glucose homeostasis was studied in 7 other subjects using the euglycaemic clamp technique in which the endocrine pancreatic function was fixed at its basal level with somatostatin together with replacement of basal insulin and glucagon by the exogenous infusion of these hormones. In this new metabolic conditions, beta-endorphin failed to have significant influences on the various parameters of tracer-estimated glucose metabolism (production, utilization, and clearance) and on the plasma levels of the gluconeogenic precursors (glycerol and alanine). Moreover, the levels of pancreatic and counterregulatory hormones (cortisol and catecholamines) were not different between beta-endorphin and control studies. We conclude that the naturally occurring opioid peptide beta-endorphin produced an hyperglycaemic effect in man which appears to be mediated by glucagon. The opioid seems to have no direct effect on glucose metabolism. These results suggest that the metabolic effects of beta-endorphin in normal man are secondary to its impact on pancreatic hormone secretion and not a consequence of a direct modulation of glucose metabolism.

Adult↗
PubMed1987

Thymopoietin and thymopentin enhance the levels of ACTH, beta-endorphin and beta-lipotropin from rat pituitary cells in vitro.

Thymopoietin and thymopentin are well characterized polypeptides influencing immunoregulation by several mechanisms. Proposed as a therapy in diseases with major immune abnormalities such as rheumatoid arthritis, thymopentin improved within 2 weeks some clinical parameters as pain and joint swelling. The hypothesis that this spectacular effect could be mediated through interactions with anti-inflammatory (ACTH) and pain relieving (beta-endorphin) hormones producing cells was tested on the rat isolated pituitary cell model. Thymopentin and thymopoietin can enhance in vitro the levels of ACTH, beta-endorphin and beta-lipotropin in a time- and dose-dependent fashion for physiological concentrations ranging from 10(-12) to 10(-8) mol/l. The action on pituitary cells was restricted to those molecules as no changes occurred in LH, FSH, GH, TSH and PRL levels, after otherwise identical experimental conditions.

Adrenocorticotropic Hormone↗
PubMed1987

Methods of clinical and biological assessment of rheumatoid arthritis.

Inflammation has long been recognised as notoriously difficult to measure both in clinical practice and in the laboratory. Of all the cardinal features of inflammation, pain relief is really what the patients want, and among disabled persons, rheumatic patients are the only ones who must cope with chronic pain. The rheumatologist, however, is also interested in other parameters that are thought to reflect improvement of the inflammatory process. The methods used to clinically assess rheumatoid arthritis (RA) should share the following four parameters: validity, sensitivity, reliability and simplicity. Unfortunately, at present, no single ideal method is capable of accurately reflecting disease activity in RA. The measurement of pain relief by the visual analogue scale, the determination of the Ritchie index and the duration of morning stiffness, plus patient assessment of global response should be enough to detect clinical activity of the drug in RA. If we are working with slow-acting drugs or so-called disease modifying antirheumatic drugs (DMARDs), it should be appropriate to include X-ray analysis and laboratory tests in the evaluation. A reduction in the number of fresh erosions and/or the healing of present erosions can give reliable information on the capacity of the drug to really modify the course of the disease. At present, measurement of the erythrocyte sedimentation rate and of acute phase serum proteins seems to offer the best available assessment during early weeks of therapy. The other biological tests are of limited value in reflecting or predicting a beneficial clinical response to DMARDs.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis, Rheumatoid↗
PubMed1987

[Inhibin].

Chemical structure of inhibins is known: there are molecules constituted by two subunits alpha and beta (A or B). Inhibin displays actions at hypophyseal, hypothalamic and gonadal levels. Produced by granulosa cells in female and by Sertoli cells in male, inhibin synthesis is stimulated by FSH, androgens and reduced by hypophysectomy and progesterone. At the present time, there is no evidence for a signal from germinal cells to modify inhibin production. Inhibin secretion parallels with follicular maturation as aromatase activity whereas luteinization arrests its production. Sperm inhibin levels are correlated with spermatozoa number. Its administration to the sheep induces either an anovulation or an increase of ovulation rate according to the scheme of treatment.

Animals↗
PubMed1987

[Endocrine, paracrine and autocrine mechanisms involved in follicular development].

Development of a single follicle during the menstrual cycle is under control of hormones stimulating follicular maturation, ovulation and luteogenesis. Several factors intervene locally to avoid other follicles developing at the same time as the dominant follicle. These other follicles remain quiescent or go on to atresia. Atresia results from the action of several endocrine, paracrine and autocrine mechanisms which synergistically inhibit aromatase activity. The subsequent lack of oestrogens reduces granulosa cell multiplication. The oocyte will not become fertilizable before the preovulatory peak of LH, after the resumption of meiosis and after reaching the metaphase of the second meiotic division. Several factors are involved in this inhibition of spontaneous resumption of meiosis: cyclic nucleotides, sex steroids, somatostatin, oocyte maturation inhibitor(s) (OMI). Ovulation is related to breakdown of connective tissue synthesized by granulosa cells under the influence of FSH. Connective tissue lysis is dependent on proteolytic enzymes which are released and activated by FSH, LH and relaxin. A paracrine control could be involved in ovulation: LH induces the production of prostaglandin and relaxin by theca cells which, in turn, stimulate collagenase and proteoglycanase secretion by granulosa cells.

Female↗
PubMed1987

Assessment of the biological effectiveness of nasal synthetic salmon calcitonin (SSCT) by comparison with intramuscular (i.m.) or placebo injection in normal subjects.

For patients who require treatment over a period of some years, intranasal administration of synthetic salmon calcitonin (SSCT) obviates the discomfort associated with administration by injection. Moreover, this mode of administration is not associated with the side effects normally encountered when calcitonin is injected intramuscularly or subcutaneously. The aim of this study was to assess, in normal subjects, the biological activity of nasal SSCT by comparing the fluctuations of parameters reflecting calcium-phosphorus metabolism after nasal instillation, injection of SSCT and injection of placebo, respectively. In nine healthy subjects, this instillation of 200 IU of SSCT into the nasal cavity caused a fall in serum calcium, a fall in serum phosphorus and a transient rise in parathyroid hormone levels similar to that observed after the intramuscular (i.m.) injection of 80 IU of SSCT. SSCT whether administered by the nasal route or by injection, does not inhibit endogenous calcitonin secretion. There were no changes in serum beta-endorphin, magnesium or erythrocyte magnesium levels after administration of calcitonin by the intranasal route or by injection.

Administration, Intranasal↗
PubMed1987

Increased concanavalin A-binding capacity of immunoglobulin G purified from sera of patients with rheumatoid arthritis.

A solid phase radioimmunoassay was set up for direct measurement of the binding capacity of human IgG to three lectins recognizing different carbohydrates of the Fc domain, i.e. peanut agglutinin (PNA), Concanavalin A (Con A) and pokeweed mitogen (PWM) which mainly bind to beta-galactose, alpha-mannose and dimers of N-acetyl-beta-glucosamine respectively. The mean specific binding of the 96 normal IgG tested to PNA and to PWM was statistically higher (P less than 0.001) than that to Con A, whereas no significant differences were observed between the mean specific bindings to PNA and to PWM. A statistically significant linear negative correlation could be established only between the relative bindings (expressed in percentage of the total binding to the three lectins) to PNA and to PWM (r = -0.65, P less than 0.001). The mean specific binding of IgG purified from 34 patients suffering from rheumatoid arthritis (RA) to PNA and to Con A was statistically higher (P less than 0.001) than that reached with PWM, whereas no significant differences were noted between their mean binding capacities to PNA and to Con A. When compared to normal IgG, only four out of 34 RA IgG exhibited a significantly higher binding capacity to PNA, whereas all but one RA IgG possessed a significantly higher binding capacity to Con A. Accordingly, the mean specific binding of RA IgG to Con A was significantly higher than that of normal IgG (P less than 0.001). Besides (and contrary to normal IgG), a statistically significant negative linear correlation was noted between the relative bindings of RA IgG to PNA and to Con A (r = -0.89, P less than 0.001). All the five RA IgG tested exhibited an abnormal circular dichroism. Our data suggest that, by altered steric conformation and glycosylation, mannosyl-residues of RA IgG become prominent or terminal or both, and are therefore able to react more effectively with Con A than normal IgG do.

Adult↗
PubMed1986

[Algodystrophy].

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Humans↗