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Biomedical subjects

M Audran

Publications and source records attributed to M Audran.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Male osteoporosis].

Careful examination as well as biochemical and hormonal investigations should be performed in men suffering from vertebral crush fractures, in order to detect a destructive skeletal process (multiple myeloma, bone metastatic lesions, lympho and myeloproliferative disorders), a mineralization defect (osteomalacia) or a secondary osteoporosis: primary hyperparathyroidism, hypogonadism, hyperthyroidism, renal hypercalciuria, alcoholism and tobacco smoking. The diagnosis of idiopathic osteoporosis should be made only after these causes have been excluded; the pathogenesis of the disease is unclear but risk factors have been identified: family history of osteoporosis, low dietary calcium intake, delayed puberty, ethanol use, tobacco smoking, inactive lifestyle and lean body build. Correction of risk factors, calcium supplementation, regular program of weight bearing physical activity, in some instances correction of testosterone deficiency may be of benefit to reduce bone loss. Severe osteopenia or osteoporosis may require sodium fluoride therapy.

Absorptiometry, Photon↗
PubMed1994

[Iatrogenic demineralizing osteopathies].

Long-term corticosteroid therapy is the most frequent and most severe cause of iatrogenic osteoporosis. Hypocalcaemia, subsequent to the induced negative calcium balance, may lead to secondary hyperparathyroidism. Corticosteroids also affect bone itself, probably by disrupting the production of growth factors. Bone resorption increases and bone formation decreases leading to a reduction in total bone mass. The relative immobilization resulting from the corticoid-induced myopathy or the underlying disease may accelerate the process. On the average, after one year of treatment, 5% of the bone mass is lost, and loss may reach as much as 10 to 30% at certain sites. Nearly 40% of all subjects on long-term corticosteroids suffer fractures. Other iatrogenic causes include anticonvulants which perturb phosphocalcium metabolism, 1-thyroxin which leads to bone loss when administered for hormone substitution, gonadotropin-releasing hormone antagonists which inhibit the hypophyseal-ovarian axis, tamoxifen (used in the treatment of breast cancer) which has an oestrogen-like effect, and other circumstances such as chemotherapy and long-term heparin. The gravity of iatrogenic osteroporosis thus requires preventive measures. Calcium and vitamin D supplements can compensate for impaired intestinal absorption of calcium but have no effect on bone density. One-alpha hydroxyl derivatives have been suggested but their effect remains controversial. Calcitriol can prevent bone loss in the lumbar vertebrae but hypercalcaemia occurs in one-fourth of the cases, limiting its use. Recent reports have shown that anti-oestroclastic agents may be useful. Nandrolone decaonate would have a favourable effect on bone loss but also causes virilization. In patent osteoporosis, fluorine can be combined with calcium resulting in increased lumbar bone density. Calcitonin and calcium can also be combined to induce a rise in bone density. The long-term effects of these treatments in terms of reduced fracture risk remain to be determined. A better understanding of the adverse effects of the different classes of corticosteroids is essential for optimal treatment. In cases requiring long-term therapy implicating the risk of iatrogenic osteoporosis, bone density quantitation can be a valuable means of evaluating bone loss, and of adapting preventive or corrective measures.

Adrenal Cortex Hormones↗
PubMed1994

[Osteomyelitis in the pagetic tibia].

Osteomyelitis developing in pagetic bone is a very rare event, of which only one instance has been reported to date, in a patient with mandibular disease. We have managed three patients with osteomyelitis of a pagetic tibia. The portal of entry was a skin lesion in all three cases. A Gram-negative organism was found in all three cases and was associated with the anaerobe Bacteroides melaninogenicus in one case. One of the patients was lost to follow up before eradication of the infection. Amputation was required in the other two after unsuccessful antimicrobial therapy for 23 and four years, respectively.

Aged↗
PubMed1994

Kinetics and haematological effects of erythropoietin in horses.

A plasma kinetic study of erythropoietin (EPO) was carried out in 4 horses after subcutaneous administration (30 IU/kg bwt) of recombinant human erythropoietin (rhEPO). At standardized intervals for 48 h before injection and for 60 h post-administration, the EPO plasma levels were determined with an immunoradiometric assay based on a sandwich technique. The peak plasma concentration (30-113 mIU/ml) was observed after a delay ranging from 6 to 9 h post-administration and the drug levels reached a physiological value around 60 h following rhEPO injection. Moreover, reference values for plasma EPO concentrations, which were separately determined in 70 racehorses and 34 sport equines, ranged between 0 and 9 mlU/ml. After drug administration, no significant variations in red blood cell count, haemoglobin concentration, haematocrit or mean red blood cell volume were observed in the 4 animals. Further, minimal variations in these parameters were detected in a horse which received three 120 IU rhEPO/kg bwt doses successively. Therefore, high rhEPO doses are probably required to induce a visible haematological effect in equine species.

Animals↗
PubMed1993

Displacement of thiopental from human serum albumin by associated drugs.

Displacement of thiopental from its binding sites to 4% human serum albumin solution was studied in vitro. Experimental conditions were selected to reproduce a physiological situation. Associations were studied according to the therapeutic conditions of use of the substances (drug and protein concentrations). The unbound fraction of thiopental was obtained by equilibrium dialysis at 37 degrees C and pH 7.4. Eleven drugs were associated with thiopental in 50 combinations of drugs and molar ratios. Bromhexine, citocoline, dextromoramide, dexamethasone, and methotrimeprazine had no effect on thiopental binding. The unbound fraction of thiopental significantly increased with cefamandole, cefazolin, diazepam, desmethyldiazepam, furosemide, and fentanyl. At usual therapeutic drug concentrations, the unbound fraction increase was < 5%. Higher values, however still < 10%, were found with associated drugs that were added at maximal concentrations observed in therapy. The displacement of thiopental from its albumin binding by drugs that are normally associated with the treatment of intracranial hypertension does not modify the pharmacokinetic parameters or pharmacological effect of thiopental.

Binding, Competitive↗
PubMed1993

["Medicolegal" bone fluorosis. Apropos of 2 cases of possible criminal poisoning].

We report two cases of skeletal fluorosis in two men, 55 and 69 year-old. The physical findings and the roentgenograms were typical and chemical analysis confirmed the diagnosis. Surprisingly, fluoride concentrations in blood and urine were increased at the beginning of the hospitalizations and lower during the hospitalizations. The origin of fluor intake remained unknown, leading to consider a possible criminal poisoning. Then, we discuss the attitude of physician in a case a possible criminal poisoning: denunce the crime to the police or not, as regards french law.

Acute Disease↗
PubMed1993

Determination of urinary testosterone and epitestosterone during pubertal development: a cross-sectional study in 141 normal male subjects.

OBJECTIVES: Exogenous testosterone administration is classically detected by measuring the ratio of testosterone to epitestosterone in urine. Athletes are considered to be positive for drug abuse if the urinary testosterone to epitestosterone ratio is greater than 6. We aimed at investigating the urinary excretion of testosterone and epitestosterone during pubertal development. DESIGN: We performed a cross-sectional study of 141 normal male subjects between ages 8 and 26 years. PATIENTS: We studied 141 subjects: 32 at stage 1 of Tanner, 27 at stage 2, 30 at stage 3, 25 at stage 4 and 27 at stage 5. MEASUREMENTS: Subjects performed a 24-hour urine collection. Urinary testosterone and epitestosterone were measured by gas chromatography-mass spectrometry with selected ion monitoring. RESULTS: Urinary testosterone was 20.5 +/- 1.7 nmol/24 h (mean +/- SEM) at stage 1, 49 +/- 2.9 at stage 2, 98.8 +/- 3.4 at stage 3, 371.8 +/- 21.8 at stage 4 and 403.4 +/- 16.1 nmol/24h at stage 5. Urinary epitestosterone was 13.1 +/- 1.5 nmol/24h at stage 1, 29.1 +/- 3.3 at stage 2, 48.3 +/- 3.7 at stage 3, 156.3 +/- 14.8 at stage 4 and 221.1 +/- 18.6 nmol/24h at stage 5. The urinary excretions of both steroids increased significantly during puberty and were highly correlated with chronological age (P < 0.001). Comparison of the correlation slopes (P < 0.001) showed that the urinary profiles of testosterone and epitestosterone are not parallel during pubertal development. Two subjects presented a testosterone to epitestosterone ratio above 6, corresponding to a low urinary concentration of epitestosterone, without pathological explanation. CONCLUSION: Testosterone and epitestosterone do not present the same urinary profiles throughout puberty. Marked increases of the testosterone to epitestosterone ratio can be observed at this period and may interfere with doping tests.

Adolescent↗
PubMed1993

[Migratory algodystrophy of the lower limbs involving the foot and complicated by two fatigue fractures. An histological bone study].

A 62 year old male developed transient osteoporosis algodystrophy successively in several sites of the lower limbs (8 episodes of involvement of one or two sites over an 8-year period) three years after surgery for a chromophobic pituitary adenoma. Two stress fractures developed, during the sixth and seventh years, respectively, in bones previously affected by osteoporosis. A biopsy specimen from the distal tibia showed thin bone trabeculae and reduced cellular activity. The only etiologic factor was the patient's psychological profile characterized by anxiety and introversion.

Bone and Bones↗
PubMed1993

[Pyomyositis. Apropos of 5 cases].

Four patients meeting the "classical" criteria for spontaneous pyomyositis are reported. No local cause was found. Risk factors included diabetes mellitus (2 patients), hemopathy (one patient), and alcohol abuse (one patient). Causative organisms (Staphylococcus aureus in 3 cases and Salmonella sp in one case) were recovered from blood cultures, an unusual occurrence. CT scan studies ensured the diagnosis in every case. An additional case of pyomyositis due to Staphylococcus aureus illustrates the difficulties in the definition of disease. This patient, whose muscle lesions were remarkably well visualized by MRI with injection of gadolinium, developed infection of the sacro-iliac joint adjacent to the muscular focus of infection. This patient may have had either "primary" pyomyositis with spread to the adjacent joint or "secondary" pyomyositis caused by the joint infection which was recognized only later. Advances in medical imaging techniques suggest that the nosology of pyomyositis should be broadened using this terminology. This would underscore the unique characteristics of "classical", "primary" pyomyositis and emphasize imaging, diagnostic and therapeutic facets of the disease which are shared by both entities.

Adult↗
PubMed1993

[Study of urinary excretion of testosterone and epitestosterone glucuronides in children and adolescents].

Urinary testosterone to epitestosterone ratio (T/E) is used as a marker for illegal exogenous testosterone use. Mean value in healthy adults is 1.13 and 6 is the upper limit of the accepted range. Urinary excretion of these two steroids were studied in 57 children and teenagers at different pubertal stages, using gas chromatography coupled with mass spectrometry with selective ion detection. Urinary excretion of testosterone and epitestosterone increased significantly during puberty. Mean T/E ratio remained fairly constant but interindividual variations were marked and in one subject the T/E ratio exceeded 6. These data suggest that this test may yield false-positive results in adolescents.

Adolescent↗
PubMed1992

Benefits of caffeine ingestion on sprint performance in trained and untrained swimmers.

The influence of specific training on benefits from caffeine (Caf) ingestion was examined during a sprint test in a group of highly trained swimmers (T) and compared with the response of a group of untrained occasional swimmers (UT). Seven T and seven UT subjects swam freestyle two randomly assigned 2 x 100 m distances, at maximal speed and separated by 20 min of passive recovery, once after Caf (250 mg) and once after placebo (Pla) ingestion. Anaerobic capacity was assessed by the mean velocity (meters per second) during each 100 m and blood was sampled from the fingertip just before and 1, 3, 5, 7, and 9 min after each 100 m for resting and maximal blood lactate concentration ([la-]b,max) determination. The [la-]bmax was significantly enhanced by Caf in both T and UT subjects (P less than 0.01). However, only T subjects exhibited significant improvement in their swimming velocity (P less than 0.01) after Caf or any significant impairment during the second 100 m. In light of these results, it appears that specific training is necessary to benefit from the metabolic adaptations induced by Caf during supramaximal exercise requiring a high anaerobic capacity.

Adolescent↗
PubMed1992

[Investigation of phosphorus calcium metabolism after oral phosphorus supplementation].

Effects of oral administration of phosphorus on phosphorus and calcium parameters and on bone metabolism hormones were investigated in two studies: in the first, 12 young female adults and 8 females over 50 years of age took a single oral load dose of 780 mg elemental phosphorus, whereas in the second study assays were performed 5 and 15 days after initiation of twice-daily phosphorus supplements in 19 young adults, 14 subjects above 50 years of age who were free of osteoporosis, and 12 patients with osteoporosis also over 50 years of age. The phosphorus load was associated with an increase in intact parathyroid hormone levels (iPTH 1-84), which was more marked in subjects above 50 years of age than in younger adults. On the 15th day of phosphorus supplementation, there was no significant increase in baseline iPTH and no change in baseline dihydroxyvitamin D or osteocalcin levels; during the Nordin tests, the fractional calcium excretion index (CaU/CrU) and the fractional hydroxyproline excretion index (OH Pro/CrU) remained unchanged. In contrast, the phosphorus load was followed by a decrease in the maximum phosphorus reabsorption threshold (TMP/DFG), which was more marked on the 5th day than on the 15th day; a slight fall in serum phosphorus levels was also seen on the 15th day. These findings suggest that phosphorus supplementation should be intermittent rather than continuous. Analysis of subjects aged 50 to 69 years failed to disclose any significant differences between patients with and without osteoporosis.

Administration, Oral↗
PubMed1991

[Bone density in idiopathic hypercalciuria in men. Study by dual photon absorptiometry, X-ray computed tomography and histomorphometry].

Lumbar bone mineral density (BMD) of the L3 vertebra was evaluated by double photon absorptiometry or tomodensitometry (TDM) in 55 hypercalciuric individuals in two separate studies. In the first, in a department of nephrology, 29 lithiasis patients were studied by TDM of L3. By this technique, trabecular density was 75 +/- 23% of normal. It was lower in the 17 patients in whom hypercalciuria persisted after calcium restriction (66 +/- 15% of normal and below the "fracture threshold" in 9 cases) than in the 12 patients in whom it disappeared after the prescription of such a diet (88 +/- 26%, below the "fracture threshold" in 3 cases), this difference being significant (p less than 0.01). In another 26 patients, seen in a department of rheumatology, three of whom had osteoporosis with vertebral fracture, density was measured in 21 cases by double photon absorptiometry (mean Z score -1.9 +/- 1.0) and in 5 cases by TDM (mean BMD of L3 69 +/- 21% of normal). Mean iliac trabecular volume, measured in 8 cases only, was 70 +/- 25% of normal and was below the "fracture threshold" in 3 cases. Comparison of the two study groups was not possible because of differences in recruitment and methods of investigation. These two studies nevertheless show the existence of significant vertebral bone rarefaction during hypercalciuria in the young man. Confirmed and quantified in patients in whom the metabolic disturbance was discovered as a result of radiological abnormalities, this quantitative abnormality was also seen in patients in whom hypercalciurie was found because of renal lithiasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1991

[Study of bone repercussion in 33 cases with anorexia nervosa which 8 with fracture osteoporosis].

A national survey has regrouped 33 cases of anorexia nervosa (AN) with osseous investigations, in particular an absorptiometry of the lumbar spine. 2 groups have been defined: 25 patients without fracture (F-) and 8 patients with osteoporotic fractures (F+), including 5 cases with 12 vertebral fractures and 5 with non vertebral fractures: 31/33 have a low lumbar bone mineral content (BMC). The lumbar BMC of the F+ is significantly lower than the F-: -4.1 +/- 1.6 DS versus -2.2 +/- 1.2 DS (p less than 0.001). 5 F+ patients are under the fracture threshold (FT), (O F-), 2 F+ are on the same level as the FT, and the last F+ has a lumbar BMC 15% above the FT, but an osteoporotic wrist fracture and a very low femoral neck BMC (0.64 g/m2, normal 1.06 +/- 0.15). F+ are older (35.2 year old versus 23.6, p less than 0.001), owing the fact that the duration of the AN (+ 9.2 years, p less than 0.005) and of the amenorrhea (+ 9.8 years, p less than 0.001) are longer, although the AN began at the same age in the 2 groups. The minimum weight, the body mass index, the percentage of loss of weight are similar in the 2 groups. Phosphocalcic biological studies, which show rather high osteocalcinemia and hydroxyprolinuria (hyperremodeling), with rather high serum 1-25 OH vitamin D, do not differ between the 2 groups. Endocrinologic evaluations, with a constant hypooestradiolemia of hypothalamic origin, low somatomedinemia and normal cortisolemia, are not different between the 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗