[Relation between physical activity, muscle function and IGF-1, testosterone and DHEAS concentrations in the elderly]

OBJECTIVE

Lower amounts of circulating anabolic hormones are thought to accelerate the age related decline in muscle mass and function. Replacement therapies are promising interventions but there are problems with these therapies. Thus alternative strategies should be developed. The age related changes in hormonal status may be probably influenced by exercise. The purpose of this study was: a) to confirm with other methods, more adapted for elderly people, the results of a previous study that has shown relationship between physical activity (PA) and quadriceps muscle function with dehydroepiandrosterone sulphate (DHEAS), insulin like growth factor-1 (IGF-1). Quadriceps muscle power (Pmax) is measured in this new work with a recently developed leg extensor machine and, b) to complete the results of the first study examining simultaneously the relationship between PA, Pmax and cardiorespiratory fitness (VO2max) with DHEAS, IGF-1 and testosterone in a group of healthy elderly people.

METHODS

Fifty independent, community dwelling elderly subjects (25 mens and 25 womens) aged from 66 to 84 volunteered to participate in the study. PA was evaluated by the questionnaire and expressed using two activity indices: mean habitual daily energy expenditure (MHDEE) and the daily energy expenditure corresponding to leisure time sports activities (Sports Activity). Pmax and optimal shortening velocity (vopt) were measured on a Ergopower dynamometer. The Pmax was expressed relative to body mass, Pmax/kg (W kg-1), and relative to the mass of the two quadriceps muscles, Pmax/Quadr (W.kgQuadr-1). VO2max has been measured during a maximal treadmill exercise.

RESULTS

In women, IGF-1 correlated significantly with MHDEE (r = 0.54, P = 0.004), Pmax/kg (r = 0.54, P = 0.004) and Pmax/Quadr (r = 0.46, P = 0.02), whereas DHEAS with MHDEE (r = 0.54, P = 0.004), Sports Activity (r = 0.65, P < 0.001), VO2max (r = 0.46, P = 0.02), Pmax/kg (r = 0.46, P = 0.02) and Pmax/Quadr (r = 0.55, P = 0.004). No such correlation was found in men.

CONCLUSION

These findings confirm that in healthy elderly women physical activity, cardiorespiratory fitness and quadriceps muscle function are similarly related to levels of circulating DHEAS and IGF-1 suggesting a favourable influence of exercise on anabolic hormonal production in the elderly.

[Biochemical diagnosis of pheochromocytoma and neuroblastomas]

Pheochromocytoma and neuroblastoma are distinct tumours, but their biological diagnosis is based on secretion increase of one or several catecholamines. Assays have to be very sensible and specific for an early diagnosis. 24 hours urinary catecholamines and metabolites are currently measured, but technical improvements permit plasma metanephrine assay, an excellent indicator of pheochromocytoma. HPLC coupled to electrochemical detection represents the most efficient methodology. After a review of urinary and plasma assay methods, the authors show usual values of catecholamines, metanephrines, HVA and VMA, according to ages, and give examples of results encountered in classical or not tumours and in falsely positive cases. Urinary metanephrine assay is the most sensible and specific in biological diagnosis of pheochromocytoma, while catecholamines and VMA assays lack of sensibility. Results have to be given by 24 hours and by creatinine ratio. Metanephrine assay can be performed also in plasma and exhibits the same interest. However, in urine as in plasma, in case of renal failure, results cannot be interpreted. Neuroblastoma biological diagnosis is based classically on HVA, VMA, and dopamine assays, nowadays only in 24 hours urine (or in urinary micturition for screening), and results are also expressed as creatinine ratio. But even if several assays are advisable, 5% of the neuroblastoma cases do not produce increased catecholamine values. In some cases, metanephrine assay could be of interest. After the age of 12 months, clinical expression of neuroblastoma is dramatic in 70% of cases. So, a biological screening has been experimented in several countries including France. A French translation of the consensus conference report (1998) is appended, which shows the complexity of neuroblastoma screening. Now, there is no evidence that early tumour detection by screening lessens the mortality rate, but a weak benefit is not excluded.

Comparison of progesterone concentration determination by 12 non-isotopic immunoassays and gas chromatography/mass spectrometry in 99 human serum samples

A single serum progesterone determination may be highly predictive for early pregnancy and in vitro fertilisation and embryo-transfer outcomes. We therefore compared 12 direct non-isotopic progesterone immunoassays with gas-chromatography/mass spectrometry (GC/MS). For each assay, data from the analysis of 99 individual sera were compared with data obtained by GC/MS, using regression and bias plot analyses and the ratio method. We observed a larger difference in concentration between high and low values and a broader distribution of results for immunoassays than for GC/MS. All immunoassays displayed bias in the calibration process and a lack of specificity and/or sensitivity, to various degrees. We tried to identify the parameters of the assay procedure that might contribute to these discrepancies. None of the criteria investigated (antibodies, control and preparation of calibrators, blocking agents and choice of tracer) had a significant effect when studied alone.

Evaluation of the rennin-angiotensin-aldosterone system in hypertensive Ivoirian subjects--preliminary results

Experimental data on the renin-angiotensin-aldosterone system in black Africans are very limited. In this study we set up our own values (plasma renin and aldosterone) in a group of normotensive Ivoirian male and female (N = 43) subjects and compared our results with those published for the white population. The values were approximately the same. A parallel study was carried out in a black population (N = 48 men and women) consulting a doctor for the first time for hypertension in different regions of Côte d'Ivoire. The mean values of plasma renin and aldosterone were significantly higher (P < 0.05) in the hypertensive compared with the control group.

Lack of correlation between 6-month fluctuations in habitual physical activity and testosterone. Concentrations in elderly subjects

BACKGROUND

To examine the influence of long-term modifications in habitual physical activity (PA) on resting total testosterone (TT) concentrations in a group of healthy elderly subjects.

METHODS

EXPERIMENTAL DESIGN

6-month prospective study.

SETTING

University research departments of exercise physiology and geriatric medicine.

PARTICIPANTS

thirty-one independent, community dwelling elderly subjects (16 men and 15 women) aged > 65 who volunteered to participate.

INTERVENTIONS

correlational study.

MEASURES

PA was evaluated by a questionnaire QAPSE (Questionnaire d Activité Physique Saint-Etienne) and expressed by two activity indices: mean habitual daily energy expenditure (MHDEE) and daily energy expenditure corresponding to leisure time sports activities (Sports activity index).

RESULTS

Changes in resting TT concentrations were not related to changes in MHDEE (r = -0.28; p = 0.30 and r = -0.001; p=0.99) and Sports activity (r = -0.30; p = 0.26 and r = -0.05; p = 0.85) in men and women, respectively. Similarly, relative (%) changes in TT were not related to relative changes in MHDEE (r = -0.16; p=0.55 and r = 0.17; p=0.55) and Sports activity (r = -0.11; p=0.68 and r = 0.02; p = 0.92).

CONCLUSIONS

The levels of habitual PA undertaken by an average senior do not appear to affect TT levels in healthy active elderly men and women.

Determination of plasma methoxyamines

The determination of plasma methoxyamines is the most informative parameter for the diagnosis of pheochromocytoma. Very good sensitivity and specificity are necessary for this. The measurement of deconjugated (free plus sulfate-conjugated) metanephrines is more useful. Concentrations are 10-fold higher than free metanephrine concentrations. The methodology generally uses a column purification and high performance liquid chromatography with electrochemical detection. We have tested six commercial columns used for the purification step. We chose a rapid and reliable method with a mixture of strong cation-exchange and strong anion-exchange groups bonded onto a silica column. This protocol has been validated with samples of plasma from normal subjects, healthy elderly people, renal failure patients and patients with pheochromocytoma.

Leg extensor power and dehydroepiandrosterone sulfate, insulin-like growth factor-I and testosterone in healthy active elderly people

We examined the association between quadriceps muscle function and serum levels of dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor I (IGF-I) and testosterone in a group of healthy elderly people. Fifty-three independent, community-dwelling elderly subjects (26 men and 27 women) aged from 66 to 84 years volunteered to participate in the study. Physical activity (PA) was evaluated by a questionnaire. Quadriceps maximal muscle power (Wmax) and optimal shortening velocity (v(opt)) were measured on a friction-loaded non-isokinetic cycle ergometer. The Wmax is expressed in relation to body mass (W(max/kg), W x kg(-1)), and in relation to the mass of the two quadriceps muscles (W(max/Quadr), W x kg(Quadr(-1))). In women, when adjusted for age, anthropometric measurements and PA indices, IGF-I correlated significantly with W(max/kg) (partial correlation: r = 0.59; P = 0.001), W(max/Quadr) (r = 0.58; P = 0.002) and v(opt) (r = 0.53; P = 0.004), whereas DHEAS was correlated significantly with W(max/kg) (r = 0.54; P = 0.003) and W(max/Quadr) (r = 0.58; P = 0.002). No such correlation was found in men. These findings indicate that in healthy elderly women lower values for quadriceps muscle Wmax and v(opt) are related, independently of age, anthropometric measurements and PA indices, to lower circulating levels of DHEAS and IGF-I.

Influence of acute and chronic exercise on insulin-like growth factor-I in healthy active elderly men and women

We examined the influence of physical activity (PA) and acute resistance exercise on insulin-like growth factor I (IGF-I) in 39 healthy, independent, community-dwelling elderly volunteers (14 men and 25 women) aged from 66 to 84. In a longitudinal non-interventional study, we compared the fluctuations in IGF-I levels and changes in habitual PA over a 6-month period. PA was evaluated by a questionnaire QAPSE (Questionnaire d'Activité Physique Saint-Etienne), and expressed by two activity indices: mean habitual daily energy expenditure (MHDEE), and daily energy expenditure corresponding to leisure time sports activities (sports activity index). In an experimental design we compared IGF-I levels before, at 1 and 15 minutes after short quadriceps muscle exertion (10 consecutive repetitions) carried out with optimal muscle power development. Changes in IGF-I levels over a 6-month period were positively related to changes in MHDEE (r = 0.41; p<0.01), and sports activity (r = 0.40; p<0.02). When analyzed by gender, these correlations were still statistically significant in women (r = 0.39; p = 0.05 and r = 0.41; p<0.05), but not in men (r = 0.36; p = 0.21 and r = 0.20; p = 0.50). No changes (p = 0.17) were observed in serum IGF-I concentrations after the acute exercise protocol. These findings indicate that IGF-I levels are positively related to fluctuations in habitual PA, at least in women. Further research is needed to establish the best intensity and duration of exercise training to induce these changes.

[Validity of immunochemical methods for bloody progesterone: a study performed in 1998]

The aim of this study was to compare, with manufacturer's agreement, twelve direct and non-isotopic commercial assays of progesterone. We have evaluated the analytical performances: low limit detection, imprecision, accuracy (recovery and dilution tests) and we have tested some patient samples. Results were compared to a reference method using isotope dilution Gas Chromatography and Mass Spectrometry combination (GC-MS). For each assay, analytical qualities and defaults are established. Large differences are found between progesterone concentration measured on the same sample with the different methods essentially for the low concentrations. Comparison with GC-MS raised questions about the accuracy of the different assays. This work will be aid laboratories to their choice and/or validation.

Physical activity and dehydroepiandrosterone sulphate, insulin-like growth factor I and testosterone in healthy active elderly people

OBJECTIVE

to examine the association of physical activity and cardio-respiratory fitness with dehydroepiandrosterone sulphate (DHEAS), insulin-like growth factor I (IGF-I) and testosterone in healthy elderly people.

DESIGN

cross-sectional study.

SETTING

university research department and department of geriatric medicine.

PARTICIPANTS

60 independent, community-dwelling elderly subjects (26 men and 34 women) aged 66-84 who volunteered to participate.

MEASUREMENTS

physical activity was evaluated by the Questionnaire d'Activité Physique Saint-Etienne and expressed by three indices: mean habitual daily energy expenditure (MHDEE), daily energy expenditure (DEE) [comprising activities with intensities corresponding to at least three metabolic equivalents (MET; 3.5 ml.kg1 x min1 of oxygen consumption)] and sport activity. Cardio-respiratory fitness was expressed by maximal oxygen consumption (VO2max).

RESULTS

In women, DHEAS correlated with VO2max (partial correlation: r=0.33; P=0.05), MHDEE (r=0.50; P=0.002), DEE > 3 METs (r=0.49; P=0.003) and sport activity (r=0.35; P=0.04) whereas IGF-I correlated with MHDEE (r=0.48; P=0.004). DHEAS was correlated with IGF-I (r=0.43; P < 0.02) and with testosterone (r=0.41; P < 0.02). No such correlation was found in men.

CONCLUSION

lower habitual physical activity is related to lower levels of circulating DHEAS and IGF-I independently of age and anthropometric measures. Lower maximal aerobic capacity is associated with lower DHEAS concentrations, in healthy elderly women.

[Pregnancy and perinatality: biological follow-up]

Blood and urinary tests which are necessary for pregnancy diagnosis and follow-up, for newborn and mother medical supervision, during the month following birthday, are today described in reglementary texts, laws, and recommendations such as advised medical references (RMO). These documents specify the nature of obligatory tests, the checking rhythm and the list of useless tests. hCG research remains necessary for pregnancy diagnosis, but hCG dosage is essential only in case of programmed medical assistance or pathological pregnancy (extrauterine pregnancy, hydatiform mole, choriocarcinoma). The obligatory follow-up of a pregnant woman includes determination of blood groups, research of infectious agents responsible for diseases (toxoplasmosis, rubeola, hepatitis B, syphilis), proteinuria and glycosuria research and blood count according to a given calendar. When the mother's condition is bad and reminiscent of a pathological pregnancy, when a genetic risk exists for the fetus or when fetal growth is abnormal as indicated by echographic control (intra-uterine growth retardation), laboratory tests are used to follow the maternal pathological course (arterial hypertension, diabetes mellitus, anemia, bacterial, viral or parasitic disease), to verify the existence of a genetic disease, to know about the fetal functional state (by amniocentesis or cordocentesis), to identify an erythrocyte fetomaternal incompatibility. Since last trimester pregnancy accidents are able to endanger mother's and fetus lives, the feto-maternal follow-up must be adjusted to pathological diagnosis types and requires a particular supervision of the delivery. Finally mother and child must undergo a post-natal follow-up during the four weeks after birthday (perinatality control).

Convenient chromatographic prepurification step before measurement of urinary cortisol by radioimmunoassay

We applied various prepurification protocols (extraction with different solvents, liquid/solid separation on bonded silica media, Celite, and Sephadex LH20 chromatography) with a range of commercially available RIA kits to measure cortisol in urine samples. We then compared the results with the concentrations measured by a HPLC method validated with reference to isotope dilution gas chromatography-mass spectrometry. We conclude that chromatography on a commercial, prepacked diol minicolumn (Waters Sep-Pak Vac RC) in combination with dichloromethane extraction is a convenient and very effective purification step before RIA of urinary cortisol in patients not receiving corticoid medication. We tested numerous steroids for interference and found that free polar cortisol derivatives (hydroxylated or hydrogenated) could only partially account for the overestimations routinely encountered when free urinary cortisol concentrations are measured by direct RIA.

[Measurement of biological activity of hLH. Multicenter study]

This report describes the results of a multicentric study of biological methods for luteinizing hormone (hLH). The production of testosterone by animal Leydig cells is used by five laboratories with different methodologies including rat, mouse and pig cells. Dose-response curves of testosterone production, quality criteria and results on a physiological population of men and women, are reported and discussed. It is concluded that the bioactive determination of hLH must be considered as a reference method used in discordances between clinic and immunological methods.

European collaborative study of LH assay: 3. relationship of immunological reactivity, biological activity and charge of human luteinizing hormone

This report describes the results of the third part of the collaborative study organized by a working group sponsored by the Community Bureau of Reference of the European Community Commission. The aim of the present work was to establish the link between immunoreactivity and biological activity of human LH, thus allowing to determine the antigenic domains of the molecule involved in the induction of the biological effect. The relationship between immunoreactivity and electric charge of hLH was also studied. This work allowed to further apprehend hLH isomorphism and its role in discrepancies observed among hLH assays and clinical status. It also made the feasibility of measuring biologically active isoforms by an immunological method to be assessed. The effect of 36 mAb with known epitopic specificity, was evaluated on both hLH binding to rat membrane receptor and hLH induced production of testosterone by porcine Leydig cells. All the epitopes located on the beta subunit were found to be strongly involved in the biological activity whereas 4/9 and 10/18 epitopes present on the alpha subunit or specific for the holomolecule respectively appeared weakly involved. Assaying biological hLH using immunological method would require that mAb specific for all the epitopes involved in the receptor activation be tested, and thus appears presently unsuitable for routine clinical evaluation. In the previous work some LH immunoassays were found to underestimate LH concentrations (J. Endocrinol. Invest 1994, 17: 397-406 and 407-416). The mAb used in liquid phase in these kits were found in the present work to be directed against the domains of LH weakly involved in the activation of the receptor and would suggest that bioactive LH would be misevaluated by these kits. The immunoreactivity of hLH isoforms separated by isoelectric focusing (IEF) in liquid phase was also determined. IEF allowed to separate three groups of hLH isoforms but none of them exhibited a specific discriminating pattern of immunoreactivity when they were tested against a panel of mAb. It suggests that, in our experimental conditions, the electric charge and the immunoreactivity of hLH were not closely linked.

Determination of urinary cortisol with three commercial immunoassays

Urinary cortisol determination was performed with three commercially available immunoassays: one enzyme-immunoassay (Cortisol Biotrol) (EIA) and two radioimmunoassays: Quanticoat Cortisol (Kallestad Diagnostics) (KD-RIA) and GammaCoat Cortisol (Clinical Assays) (CA-RIA). Four procedures were carried out. Procedure I (methylene chloride extraction) was applied to EIA and CA-RIA and procedure II (ethyl acetate extraction) to KD-RIA. Procedure III combining procedure I and column chromatography on Sephadex LH 20 in methylene chloride was applied to the three kits. Procedure IV consisting of carbon tetrachloride preextraction and extraction with cyclohexane-ethyl acetate (50:50, v/v) was applied to CA-RIA. The results obtained were compared with those of the reference technique, "on-line" HPLC with u.v. detection. Two groups of results were arbitrarily considered, those below (n = 28) and those above (n = 6) 270 nmol/l. In the first group, the results were markedly overestimated when the procedure was limited to solvent extraction. Conversely, the third procedure proved the efficiency of the chromatographic step since specificity was greatly improved in the three cases, the levels obtained with either kits being similar to those of the reference technique. The second group of results (above 270 nmol/l) yielded by the three kits were not always higher than those of HPLC when the procedure was limited to solvent extraction. When column chromatography was included in the procedure, the results were comparable to those of HPLC in three cases and lower in the three others. Since, the latter samples were collected after cortisol administration, and overestimated cortisol values obtained by HPLC might be due to the interference of some cortisol metabolites.

Specific assay for unconjugated dehydroepiandrosterone in human plasma by capillary gas chromatography with electron-capture detection

A specific and sensitive method for the determination of unconjugated dehydroepiandrosterone in plasma is described. After extraction and purification of the extracts on a Celite column, the iodomethyldimethylsilyl ether derivative of dehydroepiandrosterone was isolated on an aluminium oxide column and assayed by gas chromatography with electron-capture detection. The method is sensitive: sample volumes of 0.5-1 ml are sufficient for the determination of dehydroepiandrosterone in plasma of normal male and female subjects aged 1-80 years. The assay is highly specific and has the potential to be used as a reference method for the determination of unconjugated dehydroepiandrosterone in biological samples.

Nitrogen-sparing effect of epidural administration of local anesthetics in colon surgery

A nitrogen-sparing effect of epidural anesthesia has been clearly demonstrated in gynecological and lower abdominal surgery. To determine if epidural anesthesia also has a protein-sparing effect during major upper or mid-abdominal surgery, postoperative nitrogen balance and 3-methylhistidine urinary excretion (an index of skeletal muscle protein catabolism) were measured for 6 days in 28 patients who had undergone colon resection for cancer with general anesthesia (N2O-O2-1% enflurane) either supplemented with low dose fentanyl plus intermittent systemic pentazocine for postoperative pain (n = 13), or the same general anesthetic plus epidural injection of either etidocaine 1% intraoperatively and bupivacaine 0.25% postoperatively (n = 8) or meperidine (n = 7) for 48 hr after skin incision. The cumulative 6-day nitrogen balance and the cumulative 3-methylhistidine urinary excretion were significantly less after epidural injection of etidocaine intraoperatively and bupivacaine postoperatively than in the two other groups. There was a significant correlation between the daily urinary excretion of 3-methylhistidine and the daily nitrogen balance in the three groups. This study suggests that in colon surgery, epidural analgesia with local anesthetics in the postoperative period improves nitrogen balance and this effect takes place partly in the muscle.

Production of monoclonal antibodies to dehydroepiandrosterone-sulphate after immunization of mouse with dehydroepiandrosterone-bovine serum albumin conjugate

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.

Effects of intermittent electrical stimulations on muscle catabolism in intensive care patients

To determine whether muscular contractions obtained by electrical stimulation in immobilized patients are able to reduce muscle catabolism, we studied 10 patients (65-79 yr old) hospitalized in the intensive care unit for postoperative ventilatory failure or cerebral infarction. Artificial nutrition was the same for each patient during the 9-day study period. Two periods of 4 days were defined and randomized for each patient, separated by one day. During the muscular stimulation (MS) period, intermittent electrical stimulation of the muscles of the legs (external electrodes), were performed daily during 2 X 30 mn. During the other period, muscular stimulations were not performed. Urinary excretion of nitrogen (micro-Kjeldhal digestion and Nessler procedure), creatinine (Jaffe reaction), and 3-methyl histidine (3-MH) (gas phase chromatography) was measured every day. (table; see text) We conclude that a significant decrease in 3-MH and creatinine excretion is observed during the MS period. In intensive care unit patients, muscle protein breakdown may be influenced by intermittent muscular electrical stimulation.

Determination of urinary estradiol using an enzymatic method during the menstrual cycle. Comparison with an method using isotope dilution-mass spectrometry (ID-MS)

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.

[Comparison between the value of urinary free cortisol and 17-hydroxycorticosteroids for the diagnosis of Cushing's syndrome]

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.

[Effects of intermittent muscle stimulation on muscle catabolism in patients immobilized in the ICU]

Are muscular contractions obtained by electrical stimulation able to reduce muscle catabolism in immobilized patients? Ten patients (65 to 79 yr old), hospitalized in an intensive care unit for postoperative failure or cerebral infarction, were studied during nine days. Artificial nutrition was the same for each patient during the study. Two periods of four days where defined and randomized for each patient, separated by one day; during the stimulation period (S), intermittent electrical stimulation of the muscles of the legs (external electrodes) was performed daily 2 X 30 min; during the non-stimulation period (NS), muscular stimulation was not performed. Urinary excretion of nitrogen (micro-Kjeldhal digestion and Nessler procedure), creatinine (Jaffé reaction) and 3-methylhistidine were measured every day. Results (X +/- SD) are as follows: the nitrogen balance (g/d) was -1.29 +/- 1.26 during the NS period and 1.43 +/- 1.10 during the S period (NS); 3-methylhistidine (mumol/kg/d) was 3.78 +/- 0.37 during the NS period and 3.15 +/- 0.32 during the S period (p less than 0.01); creatinine (mumol/kg/d) was 92.9 +/- 6.8 during the NS period and 72.9 +/- 25 during the S period (p less than 0.01). It is concluded that a significant decrease in 3-methylhistidine and creatinine excretions is observed during the S period. In intensive care unit patients, muscle protein breakdown may be influenced by intermittent electrical muscle stimulation.

[Analysis of 94 dexamethasone tests in a population of patients manifesting depressive symptomatology within the framework of a manic-depressive psychosis or other psychotic state]

The authors report a study of 94 dexamethasone-suppression-tests conducted in a group of 29 patients with either a manic-depressive psychosis (n = 14) or a depressive symptomatology associated or not with a chronic psychotic disorder. 1 mg of dexamethasone was given orally at 11 p.m. and plasma cortisol levels were determined the following day at 4 p.m. The same day, a MADS was calculated. These tests were repeated every month for each patient independently of the clinical state. 9 patients received between 4 and 11 tests. A non suppression (cortisol plasma levels greater than or equal to 140 nmol/l) was observed in 27% of the tests. A comparable percentage was obtained in the whole group of patients and in the manic-depressive psychosis group. A good correlation appeared between plasma cortisol level at 4 p.m. and score for MADS. The study of the validity of the test shows a sensibility of 50% and a specificity of 85%. These results are similar with those presented in the literature.

Urinary 5 alpha-androstane-3 alpha, 17 beta-diol (5-Ad) determination in healthy children and adults

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.

Androgen metabolism in vitro by human leukocytes, variations with sex and age

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.

[Comparison of radial immunodiffusion and laser nephelometry for the determination of pregnancy specific beta 1-SP1-glycoprotein in plasma]

Concentrations of pregnancy-specific beta 1-glycoprotein were assayed in 137 plasmas by radial immunodiffusion and laser nephelometry. The two methods were evaluated in parallel. A good correlation factor was founded for SP1 values above 60 mg/l. Although the sensitivity of both methods at low concentrations remained unsatisfactory, that of laser nephelometry was superior and therefore to be preferred.

[The deficiency of 17-hydroxylase: a cause of growth and puberty retardation in the girl. One case]

A case of 17-hydroxylase deficiency in a 14 years old girl is reported. She presented with the unique association of hypertension, hypokaliemia, delayed puberty and growth failure. It is suggested that the reduced statural growth starting between 7 and 10 years of age and accompanied by a markedly reduced bone maturation was, at least in part, the consequence of the absence of adrenarche. The secretion rate of cortisol was very low while an increased production of D.O.C. and corticosterone was demonstrated by the elevated levels of their urinary tetrahydroderivatives. A good feminisation and a growth spurt were observed under ethinyl oestradiol substitutive therapy. A progressive normalization of the kaliemia and the blood pressure was obtained with hydrocortisone treatment but long term hydrocortisone therapy appears less satisfactory with easy clinical manifestations of overdosage on the one hand and incomplete maintenance of normal blood pressure of the other hand.

Tolerance to cold and glucose homeostasis in adrenal demedullated dogs

The rise in O2 consumption and in glucose turnover, induced by acute cold exposure is not suppressed by adrenal demedullation in dogs. However, both at neutral and cold ambient temperature, the mean plasma glucose concentrations are higher in normal (N) than in adrenal-demedullated dogs (ADMX). In the cold, the fall in rectal temperature is larger in ADMX than in N dogs.