Biomedical subjects
Publications and source records attributed to A Revol.
A 33 year-old woman with multiple sclerosis developed bilateral palatal myoclonus. Rotatory pendular nystagmus and gaze-evoked nystagmus were present and analyzed by electro-oculographic recordings. Magnetic resonance imaging demonstrated abnormal signals in the pons. To our knowledge, this is the first report of palatal myoclonus in the course of a definite case of multiple sclerosis.
C-reactive protein, synthesized by the liver, belongs to the group of proteins in the acute stage of inflammation. It has a very short half life of 6 to 8 hours with rapid evolution kinetics. The CRP level has been measured 959 times by the immuno-turbidimetric method in 500 in-patients of the Gynaecology Department of Claude Bernard Hospital. It was measured every 48 hours. The CRP level increases in the immediate post-operative period, reaches its maximum on D3 and falls back to normal between D5 and D7. The CRP level seems to be the most reliable parameter for the diagnosis of pelvic infections (namely salpingitis). It represents the best criterium to assess the effectiveness of the treatments administered to the infected patients (adnexitis, post-operative complications).
Monoclonal antibodies with a much higher specificity for DHA-S than for DHA were obtained from a BALB/c mouse immunized with a non-sulphated DHA-7CMO-BSA antigen. An improved fusion technique using PEG containing 10% DMSO instead of PEG alone increased the number of positive hybridomas. One of the five monoclonal antibodies obtained, showed a high affinity for DHA-S (Ka = 10(10) M-1) and very low cross-reactions with androsterone (0.62%) and androsterone sulphate (0.83%) which made it potentially useful for direct quantitation of DHA-S in human serum.
The immunochemical methods take a preponderant place in the measurement of gonadotropins and ovarian steroids. If the sandwich methods for the ELISA type are almost exclusively used for peptide hormones, the measurement of steroid hormones are necessarily performed by a competition technique. The relatively easy preparation of polyclonal and monoclonal anti-gonadotropin antibodies leads to antibodies with a good specificity for these hormones whereas the anti-steroid, specially monoclonal antibodies, are much more difficult to obtain. The different labeling possibilities used in the detection of the antigen-antibody complex, the quality of existing standards and the immunoassay's reliability are successfully discussed.
The regulatory effect of fibroblast growth factor (FGF) on testosterone secretion was studied by using a model of immature porcine Leydig cells cultured in serum-free defined medium. FGF enhanced in a dose-dependent manner hCG-stimulated testosterone secretion (ED50 = 11 ng/ml FGF). The stimulatory effect of FGF on testosterone accumulation was time dependent; testosterone increased to a maximal value at 24 h treatment and then dramatically declined to near control value following 48 and 72 h treatment with FGF; such a decline was not related to FGF degradation in culture medium. Although FGF increased maximal secretion of testosterone, it did not affect the human chorionic gonadotrophin (hCG) concentrations required for maximal and half-maximal secretion of testosterone (1 and 0.2 ng/ml hCG, respectively). These effects of FGF are probably exerted in the context of the local control of testicular steroidogenesis.
Specific assay of free urinary cortisol is difficult. Only high pressure liquid chromatography (HPLC) is suitable for this problem but requires pretreatment of urines. Seven protocols of purification are compared and a routine method is proposed. Performance of this is evaluated and discussed in patients with corticoid therapy.
Five commercial kits for the quantitative determination of human chorionic gonadotropin (hCG) used for detection and monitoring of pregnancy were evaluated. Five kits used two-sites "sandwich" enzymoimmunoassay and monoclonal antibodies. Precision, standardization and sensitivity were tested and practicability was assessed. Good results are obtained for four kits (Beckman had poor results), sensitivity and specificity are good. Practicability of five kits was evaluated but choose was in relation to configuration of laboratory.
The authors describe a method of titration of tetrahydroaldosterone in the urine, requiring an internal non-radioactive standard. This method uses high performance liquid chromatography as a mean of isolating tetrahydroaldosterone (THAldo) and chromatography in gaseous phase as a method of titration in the form of heptafluorobutyrate after oxidation into gamma lactone. It permits to detect 3 ng of gamma lactone of THAldo corresponding to a urinary concentration of 16 nmol/l.
Results for measurements of urinary estradiol were compared with results from a method using isotope dilution-mass fragmentography. Urine samples were collected from women during the menstrual cycle. The results obtained differed in absolute values, but showed good correlation.
The usefulness for the diagnosis of Cushing's syndrome of urinary free cortisol and urinary 17-hydroxycorticosteroid (17-OHCS) determination was compared by measuring these substances in 17 normal and 28 obese subjects and in 19 patients with established Cushing's syndrome. These measurements were repeated in 16 obese subjects and 11 Cushing's syndrome patients after oral administration of dexamethasone (2 mg/day for 2 days, then 8 mg/day for 2 days). As a group, the patients with Cushing's syndrome had higher (p less than 0.001) excretion rate of both free cortisol and 17-OHCS, but the values observed in this group overlapped with those of normal and obese subjects. The overlap was not significantly different for free cortisol and 17-OHCS excretion. In each obese subject, oral dexamethasone decreased the urinary excretion rate of both free cortisol and 17-OHCS. Seven out of the eleven patients with Cushing's syndrome had no decrease of urinary free cortisol or 17-OHCS, whereas both values were slightly lower in one and decreased to levels similar to those obtained in obese subjects in the three remaining patients. It is concluded that there is no advantage in measuring free cortisol excretion instead of 17-OHCS excretion, either before of after a pituitary-adrenal suppression test, for the diagnosis of Cushing's syndrome.
A sensitive and specific method for the determination of plasma S-DHA by gas chromatography (GC), with fused silica capillary column (stationary phase SE 54) and electron capture, after solvolysis of the sample and purification by high performance liquid chromatography (HPLC) is described. The interest of the new internal standard (5 alpha androst-9(11)-ene-3 beta ol-17-one) for the determination of the DHA by GC is shown. The analytical characteristics of this method as well as a comparative study of the values obtained by this method and by radioimmuno-assay are described.
Some authors attributed an increase in ACE activity in sarcoidosis to high production of this enzyme by alveolar macrophages. In order to study the production of ACE by peritoneal rat macrophages, we measured the ACE activity, by a modified version of Friedland and Silverstein's technique, in cultures of rat peritoneal macrophages, with dexamethasone, with Complete Freund Adjuvent (C.F.A.) or sarcoidosis node extract (Kveim Antigen). ACE activity was not detected in cultures. Our results were discussed.
The authors suggest a method for the evaluation of the urinary 5 alpha-androstane-3 alpha, 17 beta-diol (5 Ad) carried out by gas-liquid chromatography. 5-Ad is separated from its isomers, first by means of an adsorption chromatography on alumina and then by means of a high performance liquid chromatography on porous silica. The reliability criteria of the method have been studied according to the advice of the French Society of Clinical Biology. This method, applied to 175 healthy individuals of both sexes, grouped according to age starting from three years, allowed to determine the usual values of urinary excretion of 5-Ad in relation to age.
Sphingomyelinase activities were assayed in vitro in cultured skin fibroblasts of 61 patients with Niemann-Pick disease (NPD). Residual activities found in type A and B were 1% and 4%, respectively, of the mean control values, i.e. significantly higher in type B. In 27 cases with NPD type C, the mean activity was 42% of that in controls, with residual activities ranging from 15% up to normal. Fifteen pregnancies at risk for NPD type A and B were monitored; 4 affected foetuses were found. The uptake of exogenously added radiolabelled sphingomyelin by cultured cells and metabolism of the choline moiety of this lipid were studied in 35 patients with NPD and 14 controls. No difference of uptake between normal and mutant cells was observed. Normally, 77 +/- 5% of the radioactivity taken up was converted to phosphatidylcholine after 18 h incubation, compared to 5 +/- 2% (n = 7) in NPD type A. A substantially greater hydrolysis (31 +/- 12%; n = 8) occurred in NPD type B, and the test allowed complete discrimination between these two types. In NPD type C, 16 patients showed an abnormally low rate of intracellular sphingomyelin degradation (48 +/- 5%) while 4 others were not distinguishable from controls. There was a correlation (r = 0.76) between the results of the in vitro and in vivo assays, but also between the severity of the clinical symptoms and the impairment in sphingomyelin degradation. For the diagnosis of NPD type C, the in vivo test gave more reproducible and more clearcut results than the in vitro assay.
Various anomalies of pulmonary surfactant have been described in relation to acute respiratory distress syndromes, hypersensitivity lung disease and pulmonary sarcoidosis. Phosphatidylcholine (PC) is the essential phospholipid component of pulmonary surfactant. Cytidine diphosphocholine (CDP-choline) is an essential intermediary in the biosynthesis of PC. The authors studied two groups of patients: one group consisted of diffuse interstitial pulmonary fibrosis and the other consisted of pulmonary sarcoidosis with parenchymal involvement. They observed quantitative and qualitative abnormalities of the phospholipid fractions of surfactant and more particularly of PC. The finding of a marked decrease in this phospholipid, especially in the cases of pulmonary fibrosis, justified the study of the therapeutic effects of CDP-choline. After one month of treatment with this substance, at a dose of 1 g I.M. per day, the PC fraction had returned to normal and, at the same time, there was an improvement in the PaO2 at rest and after exercise. Long term administration of CDP-choline appears to be valuable in the maintenance of the phospholipid equilibrium of pulmonary surfactant and in the improvement of the quality of alveolar gas exchange.
The present study was undertaken in order to examine the metabolism of androgens by isolated human leukocytes. After incubation, steroids were extracted and purified by high performance liquid chromatography (HPLC); identification and quantification of the steroid products was achieved by gas-liquid-chromatography (GLC), radio-GLC and combined gas chromatography-mass spectrometry (GC-MS) of the trimethylsilyl derivatives (TMS). Incubation in the presence of testosterone led to the formation of 4-ene-androstenedione and 5 alpha-dihydrotestosterone (5 alpha-DHT) while in the presence of 5 alpha-DHT, the products were 5 alpha-androstane-3 alpha, 17 beta-diol (5-Ad) and 5 alpha-androstane-3 beta, 17 beta-diol. The formation of these metabolites was compared in healthy males and females of two age groups. Production of 5 alpha-DHT and 5-Ad was significantly higher in males than in females. In subjects aged 75 years or more, formation of these steroids was decreased by more than half in both sexes, but the sex differences remained. This study confirms the presence in human leukocytes of 17 beta-hydroxysteroid oxydoreductase, 5 alpha-reductase and 3 alpha- and 3 beta-hydroxysteroid oxydoreductase activities.
The authors studied the parameters of Friedland and Silverstein's technique for measuring the activity of the angiotensin I conversion enzyme and found a number of anomalies. The technique was modified by correcting the wide pH difference between the pH of the reagent and the pH of the reference solution. This modification made the technique optimal for the measurement of the enzyme activity by allowing a 20 to 40 per cent increase in this activity and a 15% increase in the positivity in cases of clinical sarcoidosis. The application of this modified test to the determination of the activity of the angiotension I conversion enzyme in control subjects, patients with sarcoidosis and patients with order respiratory diseases gave the following mean values, respectively: 39 +/- 10 IU; 81 +/- 23 IU; 41.5 +/- 2.5 IU in the serum and 0.2 IU; 1.1 +/- 0.5 IU; 0.2 +/- 0.1 IU in bronchoalveolar lavage fluid. The increase in enzyme activity in sarcoidosis is found in the serum in 75% of cases and in bronchoalveolar lavage fluid in 85% of cases. This modified technique can be applied in routine practice and in research.
The authors present an assay method for free urinary cortisol using inverted phase liquid chromatography for purification and radiocompetition for the assay. The usual values for adult men and women were established. The results of 150 routine assays were compared with those of 17 OHCS, revealing the value of this assay.