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Biomedical subjects

A Bonardet

Publications and source records attributed to A Bonardet.

29 records · Page 2Linked to original sources
PubMed1980

[Prolactin secretion during sleep at puberty. Preliminary results (author's transl)].

Plasma prolactin was measured in six normal boys, during night sleep, with simultaneous recording of EEG for determination of the various stages of sleep. Peaks of prolactin appear clearly during cycles of rapid sleep: in prepuberty, the average of night peaks of prolactin is higher than that in post-puberty subjects. These results suggest indirectly, a participation of prolactin in prepuberty adrenal maturation.

Adolescent↗
PubMed1979

[Nycterohemeral variations of growth hormone and prolactin in 6 Parkinson's sufferers treated with bromocriptine (author's transl)].

Secretions of GH and of PRL studied over a period of 24 hours in 6 untreated Parkinson's patients showed slight changes. The normal secretion of PRL in the female shows no nocturnal increase in the male. The secretion of GH linked to sleep is identified in the male and not in the female. These variations related to sex are interpreted as an increase in those normally found in the adult and facilitated by age. Bromocriptine given continuously at a dose of 10 to 20 mg/day for periods of 20 days to 6 months, results in suppression or a marked decrease in the 24-hour secretion of PRL. It has virtually no effect upon the secretion of GH. These results show that the dopaminergic regulation of PRL is preserved in Parkinson's disease.

Aged↗
PubMed1977

[Plasma prolactin levels in normal children from birth to adolescence].

Plasma prolactin levels were determined by an homologous radio-immuno assay in normal children: in cord blood, at the first day of life, during childhood and along puberty. 1. In both sexes, there is a very important secretion of prolactin during the neonatal period. 2. Longitudinal studies make obvious a different pattern of plasma prolactin in boys and in girls at puberty.

Adolescent↗
PubMed1975

[Secretions of GH, FSH and LH during sleep of the normal child and the child with retarded growth].

In normal children the major GH release begins during NREM sleep of first cycle. At puberty secretion of gonadotropins is enhanced and secretion of LH occurs with the same periodicity as the sleep cycles. Two groups of dwarfish are seen: the first lacks both GH secretion during sleep and the increase of gonadotropins at puberty. The second group exhibits GH, LH and FSH secretion patterns similar to normal children. Study of secretion patterns of GH, FSH and LH during sleep in children can document the degree of maturation of the hypothalamic pituitary hormonal system.

Adolescent↗
PubMedDate not supplied

The V-twin system (Dade Behring Laboratories): a useful tool for immunosuppressive drug monitoring.

The predose trough cyclosporine (CsA) level (C0) was widely used to assess the possibility of drug nephrotoxicity. Owing to its potential limitation as an indicator of total drug exposure, 2-hour postdose (C2) monitoring has been considered to be a more accurate marker. The V-Twin analyzer (Vital SC, Netherlands) conceived for EMIT technologies (Dade Behring Laboratories) is proposed herein to determine CsA levels using a specific calibrator without any dilution, as well as tacrolimus (FK) and mycophenolate mofetil (MMF) levels. Both CsA (C0: n = 133 and C2: n = 55) and FK (n = 121) EMIT assays were compared to the RIA CsA assay (DiaSorin Laboratory) and to the MEIA tacrolimus assay (Abbott Laboratory), respectively. In addition, the feasibility of MMF EMIT assay was evaluated. Overall, 309 transplant patients were included in this study. For all parameters tested, total imprecision studies were lower than 10%, and the coefficient of linearity was r(2) > .99. For the CsA kit, the range of linearity was between 25 and 500 ng/mL for the C0 and 400 and 2000 ng/mL for the C2 assay. The values obtained were highly correlated with the RIA for the C0 levels (EMIT = 0.9 RIA+3.66; r = .97) and for the C2 levels (EMIT = 0.89 RIA-14.2; r = .956). Similar results were obtained with the EK EMIT kit, with a linearity range between 3 and 30 ng/mL, and a high concordance with the MEIA test (EMIT = 0.98 RIA+1.09; r = .96). Preliminary MMF results in 59 sera, containing from 0.1 to 30 microg/mL, showed that this examination could be included as a routine. The V-twin system is a useful tool for routine monitoring with a single method for C0 and C2 cyclosporine, tacrolimus, and mycophenolate levels.

Animals↗
PubMedDate not supplied

Preliminary evaluation of a new chemiluminescence assay (Liaison Cyclosporine; DiaSorin Laboratories) allowing both C0 and C2 cyclosporine levels determination: comparison with RIA method.

Cyclosporine (CsA) monitoring is generally assessed by trough concentration determinations (C0). Recently, the 2-hour postdose CsA level (C2) has been proposed to be a better measurement to predict graft outcome and prevent toxicity. However, using the available methods, C2 determinations require external dilution, which impairs the precision and practicability of the assay. This study assessed the performance characteristics of a new competitive chemiluminescence immunoassay (CLIA, DiaSorin Laboratories, Anthony, France) for the determination of both C0 and C2 CsA concentrations in whole blood on a Liaison analyzer. The results were compared with the RIA method (DiaSorin) used in our laboratory as a reference technique. Analytical performances showed that the total intra-assay variation coefficients (CVs) on the CLIA Liaison ranged from 7.6% to 11.3%, while the between-day imprecision was 11% (15.2%, 11.5%, and 6.5%). The linearity of the method was estimated over the range of 30 to 2400 ng/mL as a correlation coefficient of r = .997. Recoveries, which were checked by adding pure CsA to CsA-free blood, showed a mean value of 86%. A total of 236 whole-blood samples (31% women, 69% men of mean age 45 +/- 17 years) were subjected to a comparative study of CLIA-CsA versus RIA (radioimmunoassay) values, yielding a correlation coefficient >0.90 (CLIA = 0.825RIA+21.611; r(2) > .90). In conclusion, the CLIA Liaison CsA kit represents an alternative to the radioisotopic method, which allows both C0 and C2 determinations without any preanalytical step. The chemiluminescence method demonstrated good analytical performance and practicability in routine use.

Adult↗
PubMedDate not supplied

Circadian patterns of growth hormone and cortisol secretions in narcoleptic patients.

Narcolepsy, a disorder which is clinically characterized by recurring episodes of sleep during the day, frequently associated with nocturnal disrupted sleep and polygraphically by sleep onset REM periods, has been studied in regard to the relationships between GH, cortisol secretion and sleep. Ten narcoleptics were polygraphically recorded during 24 h after one night's adaptation. Blood samples were taken every 20 min for GH and cortisol immuno-assays. Three narcoleptics were recorded twice 2 months later and 2 normal subjects served as controls. The following results were obtained: GH secretory pattern was different in narcoleptics and controls; two groups were identified: the first one showed a very low basal GH secretion with rare and small secretory peaks not clearly linked with sleep. One subject of this group recorded twice showed a similar pattern. The second group exhibited a higher basal secretion with many peaks without any well-defined relationship to sleep stages. The pattern was again consistent in two recordings of 2 subjects in this group. Furthermore GH secretion rose significantly (p less than 0.01) between 2100 and 0000 with no apparent relationship to sleep stages. The cortisol secretory pattern showed a significant rise (p less than 0.01) between 0400 and 1000 and was not different in narcoleptics and controls. In narcolepsy the monophasic sleep-wakefulness cycle is disrupted. The GH secretion pattern is modified whereas the circadian pattern of cortisol secretion is normal and independent of the sleep-wakefulness cycle of the narcoleptic patient.

Adult↗