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Biomedical subjects

N Bernard

Publications and source records attributed to N Bernard.

At least 109 records · Page 6Linked to original sources
PubMed1991

Pharmacokinetics of chlormezanone in elderly patients.

The pharmacokinetics of Chlormezanone (CM) has been determined after a single oral dose of 400 mg CM in 5 young volunteers (28 y) and in 8 elderly patients (79 y). In the young subjects, CM was rapidly absorbed and distributed, and was slowly eliminated with a half-life of 38 h major metabolites were not detected in plasma or urine. Only 3% of CM was excreted unchanged in urine. In elderly patients absorption was delayed but not reduced; the Cmax and AUC did not differ from those in younger subjects, the elimination rate was reduced compared to the younger subjects (mean 54 h). The increase was in part related to the reduction in renal function and metabolism observed in aging. However, the change in pharmacokinetics was moderate and no adjustment in dosage seems necessary for treatments of limited duration in elderly patients.

Administration, Oral↗
PubMed1991

Muscle and species reactivity of mouse monoclonal antibodies to human eye muscle membrane antigens.

We studied the tissue and species reactivity of mouse monoclonal antibodies (MCAB) produced by immunizing mice with a 100,000g ultracentrifuged preparation of human eye muscle (HEM) membranes. Twenty-three MCABs, 20 of which reacted in an enzyme-linked immunosorbent assay (ELISA) with HEM membrane, 2 with human thyroid membrane, and 1 nonreactive negative control, were selected for the study. The muscle and species specificity of 6 of the most reactive and more restrictively reactive MCAB were studied in more detail. All reacted in ELISA with human skeletal muscle membrane and, to a lesser extent, with human cardiac muscle membrane, but not with human brain membrane. The 6 MCAB cross-reacted with eye muscle membrane prepared from pig but not rat, although reactivity with human tissue was greatest for all MCAB tested. When tested in immunoblotting with HEM and thyroid membranes, 3 of 6 MCAB reacted with a 64-kDa protein in HEM, 2 of which also reacted with an antigen of the same molecular weight in thyroid membrane. In a complement-mediated antibody-dependent cytotoxicity assay, 5 of 19 MCAB lysed HEM cells, 6 of 21 lysed human skeletal muscle cells, and 10 of 22 lysed human thyroid cells. These findings support results from earlier clinical studies which showed that eye muscle membrane reactive autoantibodies in the serum of patients with thyroid-associated ophthalmopathy cross-react with membrane prepared from other striated muscle. The significance of eye muscle, skeletal muscle, and thyroid cross-reactivity of MCAB is discussed in the context of autoimmune thyroid disease and ophthalmopathy.

Abdominal Muscles↗
PubMed1991

Prevalence of antibodies reactive with a 64 kDa eye muscle membrane antigen in thyroid-associated ophthalmopathy.

We have determined the prevalences of antibodies reactive with certain pig eye muscle membrane antigens, as determined from SDS-polyacrylamide gel electrophoresis (PAGE) and western blotting, in patients with autoimmune thyroid disorders with or without associated ophthalmopathy. The most frequently detected antibody was that directed against a protein of 64 kDa. Antibodies against this antigen were detected in 33% of unselected patients with ophthalmopathy and in 75% of those with severe, active, orbital inflammation of less than 12 months duration. Such antibodies were detected also in 33% of patients with Graves' hyperthyroidism with no apparent eye disease and in 17% of patients with Hashimoto's thyroiditis with no eye disease but were not detected in patients with nonautoimmune thyroid disorders in 25 normal subjects tested. In the majority of sera showing reactivity with this protein, reactivity with membrane antigens of 55 and 95 kDa also were observed, suggesting that the three proteins were conformationally associated. Cytotoxic antibodies against human eye muscle cells, measured in antibody-dependent cell-mediated cytotoxicity (ADCC), were demonstrated in 37% of patients with ophthalmopathy. There was no significant correlation, in patients with eye disease, between positive ADCC tests and antibodies to the 64 kDa protein, the 64 kDa reactive antibody being found in 50% of patients with positive ADCC and in 35% of those with negative tests. In this study, a clear association has been shown between thyroid-associated ophthalmopathy and the detection, in immunoblotting, of antibodies reactive with a 64 kDa eye muscle membrane antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

The effect of infinitesimal drug dilutions on the pharmacokinetics of nalidixic acid and atenolol.

1. Ten healthy subjects received two treatments: a single 1 g oral dose of nalidixic acid (NA) followed 1 h later by either an infinitesimal dilution of the drug (NA 7CH) or by succussed water which served as placebo. The study was repeated 18 months later in 10 different subjects. 2. A further 10 healthy subjects received three treatments: a single 100 mg oral dose of atenolol (AT) followed 3 h later by either placebo or a dilution of AT (AT 7CH) or of bisoprolol (BI 7CH). The homoeopathic preparations were administered by the sublingual route. 3. In the first NA experiment NA 7CH significantly shortened the elimination half-life of NA from 8.6 +/- 2.2 (placebo) to 6.4 +/- 1.6 h (NA 7CH). In the second NA experiment none of the pharmacokinetic parameters was modified significantly by the administration of NA 7CH. Neither AT 7CH nor BI 7CH modified the pharmacokinetics of AT.

Administration, Oral↗
PubMed1991

Binding of peripheral blood and thyroidal T lymphocytes to thyroid cell monolayers: possible role of "homing-like" receptors in the pathogenesis of thyroid autoimmunity.

The specific binding of blood lymphocyte populations to non-antigenic receptors on high endothelial cells in peripheral lymphoid organs is well established. Such "homing" receptors in target tissues may also play a role in the early phase of organ specific autoimmunity. In this study binding of peripheral blood and thyroid-derived T cells to human thyroid (THY) cells was examined. Binding was measured as the percentage 51Cr-labelled T cells bound to THY monolayers. Interferon-gamma (IFN-gamma) enhanced the binding of peripheral blood T cells (PBL-T) from patients with Graves' disease (GD) and normals, but not from patients with Hashimoto's thyroiditis (HT), to allogeneic THY monolayers. The binding of T cells from patients with HT to untreated allogeneic THY monolayers was significantly greater than that for T cells from patients with GD or normals. TSH inhibited the IFN-gamma enhancement of binding of PBL-T from 4 normals and one HT patient to both allogeneic (n = 5) and autologous (n = 4) THY monolayers. Intra-thyroid T cells (ITL-T) bound to autologous THY monolayers significantly more than PBL-T from the same patient, while ITL from patients with HT or Graves' disease bound more than their PBL-T to both allogeneic and autologous THY monolayers. ITL-T, but not PBL-T, bound significantly more to autologous THY than to autologous thyroid-derived fibroblast monolayers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[The reproducibility of the abutment angle recording in the remounting of complete dentures].

Upon insertion, 40 newly made full dentures could be remounted three times in succession by each of two therapists by means of the intraoral central bearing point method. The records were measured electronically and by computer in a special measuring articulator in the right and left condylar area. The shift of the condylar spheres in the three different records was smaller than about 0.3 +/- 0.2 mm in all three spatial directions. From this we calculated the movement of the spheres in space to be about 0.5 +/- 0.3 mm. The results of our random samples were independent of the therapist, the patients' age or sex, the period for which the patients had been edentulous, the sliding of the dental prostheses on the tegmentum or the anatomical shape of the alveolar ridges.

Dental Abutments↗
PubMed1990

Predictive value of phase I studies: relevant criteria.

Phase I studies cannot predict the therapeutic efficacy of a new drug. However, they can lead to important information concerning: i), the undersirable effects and their mechanisms of occurrence; and ii), the pharmacokinetics and the metabolism of the drug as well as their possible alterations in renal or hepatic diseases. When considering the therapeutic effects, 3 cases have to be considered which are, in order of decreasing predictive value: i), when a direct relationship is expected between the drug concentration in the body and its therapeutic effects (eg, antibiotics); ii), when the drug has a known molecular or cellular target which is directly involved in the pathophysiology of the disease (eg, renin inhibitors); and iii), when the drug does not have a known target or is directed toward a precise target which is not directly involved in the disease. In all these cases, a phase I study in healthy volunteers should be able to describe, at least qualitatively, the pharmacodynamic effects of the drug which are relevant to its therapeutic goal.

Drug Evaluation↗
PubMed1990

Eye muscle membrane reactive antibodies are not detected in the serum or immunoglobulin fraction of patients with thyroid-associated ophthalmopathy using an ELISA and crude membranes.

We tested sera and purified immunoglobulin (Ig) fractions from patients with autoimmune thyroid disorders (AITD), with and without ophthalmopathy, and normal subjects, for the presence of antibodies reactive with eye muscle membrane antigens in an optimized enzyme-linked immunosorbent assay (ELISA). We found no correlation between ELISA results and the presence or severity of ophthalmopathy in patients with AITD for either serum or Ig, and there were no significant differences between the mean values (+/- SE) for the three groups (AITD with ophthalmopathy, AITD without ophthalmopathy and normals) for either serum or Ig. In contrast Ig from 8 of 19 (45%) patients with thyroid-associated ophthalmopathy reacted with a 64 kDa eye muscle membrane antigen in SDS-polyacrylamide gel electrophoresis and Western blotting, while tests were positive in only one of the 8 patients with AITD without eye disease and in none of the 8 normal subjects. The presence of antibodies to a 64 kDa antigen in immunoblotting did not correlate with the levels of antibodies measured in ELISA. We conclude that the ELISA, incorporating a crude membrane fractions as antigen, is not useful as a clinical test for eye muscle autoantibodies.

Adult↗
PubMed1990

Cardiovascular reactivity to and renal impact of stress and exercise: effects of bisoprolol.

The orthosympathetic nervous system is involved in the pathogenesis of essential hypertension. In this study, we carried out tests of sympathetic stimulation using successfully an isometric exercise and a psychological stress. The efficacy of the two tests in 10 normotensive patients (NTs) was assessed by a significant increase in blood pressure and heart rate and a significant increase in metanephrine urinary excretion. These tests, repeated 2 months later, were perfectly reproducible in NTs. The cardiovascular response during exercise and stress was significantly higher in 10 hypertensive patients (HTs) than in NTs. At rest, urinary norepinephrine excretion was significantly higher in HTs. In contrast to NTs, stress in HTs significantly increased urinary excretion of epinephrine and norepinephrine, whereas exercise failed to increase urinary catecholamine excretion in both groups. In HTs, both tests induced an increase in microalbuminuria. Among functional renal parameters, only proximal sodium reabsorption (measured by lithium clearance) was significantly lower in HTs than in NTs, compensated by a higher distal reabsorption. In HTs, 2 months of treatment with bisoprolol reduced rest and peak heart rate and blood pressure, but failed to reduce blood pressure reactivity to the orthosympathetic stimulation. Proximal sodium reabsorption at rest was normalized by the treatment. Bisoprolol was also able to reduce microalbuminuria during the 24 h and in the rest period preceding the test, but the same percent increase was observed during tests.

Adrenergic beta-Antagonists↗
PubMed1989

The influence of renal insufficiency and haemodialysis on the kinetics of ciprofibrate.

1. The kinetics of the hypolipidaemic drug, ciprofibrate, were studied after a single oral dose (100 mg) in subjects with normal renal function (n = 6), patients with mild (n = 6) and severe (n = 6) renal insufficiency as well as in haemodialysed patients (n = 5). 2. Under fasting conditions, ciprofibrate, was absorbed rapidly in subjects with normal renal function, and its apparent elimination half-life was approximately 81 h. Both renal clearance (0.15 ml min-1) and cumulative renal excretion (less than 7% of the administered dose) were low. 3. Mild renal insufficiency did not alter the pharmacokinetics of ciprofibrate, but severe renal impairment significantly reduced both its renal clearance and cumulative urinary excretion and increased the apparent elimination half-life. 4. A 5 h haemodialysis session did not lower the plasma concentrations of ciprofibrate. 5. It is concluded that, from a pharmacokinetic point of view, a reduction in the dosage of ciprofibrate should be considered in patients with a glomerular filtration rate below 30 ml min-1/1.73 m2.

Adult↗
PubMed1989

[Collagen colitis. Reflections apropos of 40 patients].

The aim of this study was to evaluate the frequency of a thickened subepithelial collagen band in the colon, its relationship to diarrhea, and the clinical relevance of its detection. During a 3.5 year period (May 1985-January 1989), a total of 3,323 biopsy specimens were obtained during 6,254 colonoscopies. A subepithelial collagen thickening greater than 10 microns was found in 40 patients (1.5 percent of the patients). Further assessment of these 40 patients showed that this histological lesion was characterized by a frequent association with chronic diarrhea (in 36 patients, i.e. 90 percent) whatever the cause, with diseases such as diabetes mellitus (8 cases) or inflammatory arthropathies (6 cases) and with a microscopic colitis in all cases. Course of collagen thickening was variable and independent of clinical course. Diarrhea was a constant finding when the collagen thickening was greater than 15 microns and frequently improved (12 patients/14) during treatment with Collagenan. This study suggests that a subepithelial thickened collagen band is an uncommon change in the colon and is frequently associated with chronic diarrhea. The significance of this morphological change is unknown, and its contribution to the pathogenesis of the diarrhea remains questionable.

Chronic Disease↗
PubMed1989

[Artificial induction of labor at term for medical reasons. Comparison of 2 technics for labor induction, oxytocin + early artificial rupture of the membranes versus prostaglandin E2 vaginal gel. Open randomized controlled study].

Labor induction for medical reasons is a situation rather well-controlled by the combination: "oxytocin-amniotomy" when the cervix is favorably open. However, new induction techniques are currently under study, especially vaginal administration of PGE2 which presents the advantage of being simple to administer and better accepted by the patients. This study compared the classical technique, oxytocin perfusion and early artificial rupture of the membranes, with the vaginal administration of PGE2 gel (first dose: 1 mg, second dose 1 or 2 mg, six hours later). The success rate of both techniques is comparable, approximately 70 p. cent. Also, the times between amniotomy and delivery are identical, approximately 5 hours. On the contrary, the lapses of time between the onset of the induction and the delivery, vary significantly, being always longer in the PGE2 group. However, the dose of vaginal PGE2 gel as well as the time of artificial membrane rupture could be modified in order to decrease the delay of the effect.

Administration, Intravaginal↗
PubMed1988

Role of autoantibodies in the pathogenesis and association of endocrine autoimmune disorders.

This review has focused on the nature and significance of aAB detected in the serum of patients with EAD. Although many antibodies are characteristically detected in the serum of patients with such disorders, only a few are of known pathogenic significance. Antibodies that react with soluble cytoplasmic antigens are not expected to be harmful. On the other hand, membrane or cell surface-directed antibodies are likely to be damaging, either by lysis of the cell membrane, or by reaction with hormone or other surface receptors. Clinically, measurement of aAB has important diagnostic and management value. Moreover, detection of certain antibodies before the onset of disease raises hope that the corresponding disorders may be preventable, e.g. by specific immunosuppression of those subjects, or patients, with positive tests. The possible role of aAB in the association of organ-specific AID by cross-reacting with shared epitopes in various tissues has been highlighted by the recent finding, from the authors' laboratory, of antibodies reactive with a 64-kDa membrane protein found in several tissues, including thyroid, eye muscle, and pancreas, which are frequent sites for autoimmune inflammation. Study of such antibodies and the molecular characterization of the corresponding antigens in the various involved tissues should provide information concerning the role of cross-reactivity in autoimmunity as well as leading to the development of specific immunotherapeutic agents.

Adrenal Cortex↗
PubMed1988

[Administration of a single dose of 100,000 U.I. of vitamin D3 in the pregnant woman in winter. The effect on blood calcium level of the newborn infant].

Serum levels of 25-hydroxyvitamin D [25-(OH)D], calcium, phosphate and alkaline phosphatase activity were measured between December and July in 110 pregnant women during the last trimester of pregnancy, and in their infants on the fifth day of life. This study showed a fall, during spring, below 6 ng/ml, of the maternal 25-(OH)D concentration at the time of delivery, and a fall of the 25-(OH)D and calcium concentrations in newborns. The existence of a positive correlation between calcium and 25-(OH)D levels in the newborns suggests that the low calcium concentrations found in the infants born in spring is related to a vitamin D deficiency of the infant and therefore of the mother. The administration of a single low dose of vitamin D3 (100,000 I.U.) on the sixth or seventh month of pregnancy allowed to prevent the seasonal fall in serum calcium and 25-(OH)D concentrations. This dosage appears therefore to be sufficient to reduce the risk of vitamin D deficiency of the newborn and the occurrence of neonatal hypocalcemia.

Adult↗
PubMed1988

[Ripening of the cervix uteri at term by a single intracervical application of prostaglandin E2 gel].

The efficacy and the side effects of an intracervical PGE2 gel application, as compared to placebo, for priming of the cervix have been studied in 208 patients at term (104 PGE2 and 104 placebo) with an unripe cervix (Bishop score less than 5) and with a medical indication for induction of labour. The cervical ripening success rate (as defined in methodology) is significantly higher in the treated group (58.6%) than in the control group (27.8%; p = 0.0001): 38.5% out of the PGE2 treated patients delivered within 12 hours after the gel application; 12 hours after PGE2 or placebo gel application labour was induced in the remaining patients with intravenous oxytocin infusion. Under these conditions there were 13.5% failures in the PGE2 treated group and 16.3% in the placebo group. We observed a statistically significant decrease in the length of labour of the PGE2 treated patients as compared to the control group. Since signs of myometrial hypercontractility were observed in the PGE2 treated group as compared to the control group (p = 0.01), the authors advocate careful cardiotocographic monitoring for at least three hours after the gel application. It is concluded that intracervical application of Prostaglandin E2 followed by intravenous infusion of oxytocin in an effective and safe method for induction of labour with an unfavorable cervix at term.

Adult↗
PubMed1988

[Version by external maneuvers in breech presentations. Analysis of 6 years' practice in the maternity department of Foch Hospital].

The authors report their experience over 6 years of carrying out external cephalic version (ECV) in breech presentations. The precautions that have to be observed during the manoeuvre have been described as well as the contra-indications to it. Analysing the outcome in deliveries and the state of the infants at birth after version and when version has not been carried out shows the value of this manoeuvre in terms of "economy" of the caesarean section rate and lessening in the number of breech deliveries. Evidence is shown of the good results that have been obtained and of the small level of complications. Prognostic factors for failure or of success of the version have been sought. Only multiparity has been confirmed as a factor that helps greatly. Contra-indications have to be looked at carefully to make sure that this manoeuvre stays innocuous. Finally the ways our practice and the results of attempts at ECV have been analysed throughout the 6 year period.

Breech Presentation↗