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Biomedical subjects

C Roux

Publications and source records attributed to C Roux.

At least 199 records · Page 11Linked to original sources
PubMed1993

[Bone and myeloma].

Osteolysis induced by medullary plasmocyte proliferation is related to an increase in the number of osteoclasts in contact with myeloma cells. Osteoclast activating factors (OAF), notably lymphokines such as IL-1 beta, and IL-6, or tumour necrosis factor (TNF), produced by plasmocytes or their microenvironment, have been demonstrated. Bisphosphonates, which are potent anti-osteoclastic agents, are effective during episodes of hypercalcaemia. Their ability to delay the progression of osteolysis is being evaluated.

Bone Diseases↗
PubMed1993

One-year psoas training can prevent lumbar bone loss in postmenopausal women: a randomized controlled trial.

On the premise that bone response to exercise is locally controlled, we conducted a randomized trial to evaluate the effects of a 1-year training of psoas muscles (treatment group: TG) versus a 1-year training of deltoid muscles (control group: CG) on the lumbar trabecular bone mineral density (TBMD). TBMD was measured with computed tomography scan. Seventy-eight subjects were included and 67 completed the study. Intention to treat analysis revealed no significant change in TBMD from 0 to 12 months. Data analysis in the 67 remaining women, including both assiduous and nonassiduous subjects, revealed greater bone loss in CG than in TG although the difference was not significant. Similar analysis in a subgroup of subjects who performed the exercises assiduously (TG: n = 23, CG: n = 26) showed that the mean bone loss of all four vertebrae from 0 to 12 months was significantly greater in the CG (-8.87 +/- 12.75 mg/cm3, mean +/- SD) than in the TG (0.14 +/- 11.21 mg/cm3, mean +/- SD, P = 0.01). These results suggest that continuous 1-year psoas training can prevent lumbar bone loss in postmenopausal women and support the hypothesis of local action of physical activity.

Bone Density↗
PubMed1993

Automated percutaneous lumbar discectomy versus chemonucleolysis in the treatment of sciatica. A randomized multicenter trial.

A randomized clinical trial was conducted to compare the results of automated percutaneous discectomy with those of chemonucleolysis in 141 patients with sciatica caused by a disk herniation; 69 underwent automated percutaneous discectomy and 72 were subjected to chemonucleolysis. The principle outcome was the overall assessment of the patient 6 months after treatment. Treatment was considered to be successful by 61% of the patients in the chemonucleolysis group compared with 44% in the automated percutaneous discectomy group. At 1-year follow-up, overall success rates were 66% in the chemonucleolysis group and 37% in the automated percutaneous group. Within 6 months of treatment, 7% of the patients in the chemonucleolysis group and 33% in the discectomy group underwent subsequent open surgery. The complication rates of both treatment groups were low, with the exception of a high rate of low-back pain in the chemonucleolysis group (42%). The results of this trial confirm previous controlled studies on chemonucleolysis and suggest that controlled studies should be carried out before automated percutaneous discectomy can be considered a useful intervention.

Adult↗
PubMed1993

[Ultrasound attenuation in calcaneus and bone density].

Broadband ultrasound attenuation (BUA) is a new technique for investigating bone status. We evaluated its use in osteoporosis. To assess in vivo reproducibility, we determined the coefficient of variation (cv) on the basis of five measurements (with repositioning) of the same foot in 50 women. The cv was 2.8 +/- 1.7%. BUA values were similar in the right feet and left foot and were correlated with bone density in the calcaneal area investigated (r = 0.8, p < 10(-4). BUA of the calcaneus was correlated with bone density in the lumbar spine, femur, and forearm in 240 healthy postmenopausal women (correlation coefficients 0.36 to 0.55; p < 10(-4)). BUA decreased with age, with a sharper drop during the first years following menopause. Mean broadband ultrasonic attenuation in 37 females with osteoporosis (58.92 +/- 11.59 dB/MHz) is lower than controls (66.10 +/- 15.29 dB/MHz, p = 0.04). Areas under receiver operating characteristic curves, used to evaluate the discriminating value of BUA in osteoporosis and osteopenia, were 0.79 and 0.72, respectively. The kappa coefficient of concordance between BUA and spinal density was 0.59. These data demonstrate that BUA cannot replace bone density measurements. Prospective studies are needed to investigate the potential role of this technique for identifying women at high risk for osteoporotic fractures.

Adult↗
PubMed1993

[Ivemark syndrome: 2 case reports].

Ivemark Syndrome is a multiple organ syndrome associated with splenic abnormalities, complex cardiac pathology and an abnormality of the abdominal viscera. The incidence in our department is 1/6000 deliveries and the teratogenic effect seems to occur between the 30th and 40th days of intrauterine life, but the cause is unknown. The principal warning signal is bradycardia. Prenatal diagnosis can be made by ultrasound. The prognosis depends on the degree of malformation of the heart.

Abnormalities, Multiple↗
PubMed1993

[Value of techniques of measurement of bone. Radiological methods and contribution of ultrasonics].

The current interest in bone mineral density measurements is related to the frequency, the morbidity and the cost of osteoporosis, which is considered to be a public health problem in developed countries. The main risk factor of osteoporotic fractures is the reduction of bone mineral density. This risk factor can be prevented by hormonal therapy in post-menopausal women. So it is of interest to develop the bone mineral density measurement methods, in osteoporotic bone areas or the entire skeleton (absorptiometry). But the interpretation of the result in term of individual fracture risk, the choice of the bone site to be examined, and the indication of the measurement are still being discussed. A new method of bone status evaluation is currently available: the broad band ultrasonic attenuation, which measures the attenuation of ultrasounds through the calcaneus bone. The device is portable, inexpensive and radiation free, and may give quantitative and qualitative assessment of bone. However, the normal values, the relation with the absorptiometry results and the contribution of this method in fracture risk evaluation are currently studied. Osteoporosis risk evaluation is an important point of health management in post-menopausal women and elderly people. Large prospective studies with the different methods are in progress.

Absorptiometry, Photon↗
PubMed1993

[Teratogenesis and autoimmunity: significance of an experimental murine model for human pathology].

Fetal malformations constitute a major problem of public health. Unfortunately the known causes do not account for more than 50% of the cases observed. The potential role of immune mechanisms is suggested by experimental studies in the rat indicating that antibodies reactive with the yolk sac induce fetal malformations. In this study we show that these antibodies are specific for a 280 kDa protein expressed only in the kidney and the yolk sac by cell structures associated with the formation of endocytic vesicles. We further show that a similar protein is expressed in man by the yolk sac, the kidney and the trophoblasts. The possible role in pathology of antibodies against the human protein is discussed.

Animals↗
PubMed1993

Comparative immunochemistry and ontogeny of two closely related coated pit proteins. The 280-kd target of teratogenic antibodies and the 330-kd target of nephritogenic antibodies.

We have previously shown that monoclonal antibodies specific for a 280-kd protein (gp280) concentrated within the coated pits of renal and yolk sac brush border-induced fetal malformations, whereas antibodies specific for gp330, another coated pit protein with a similar distribution, had no deleterious effect on embryonic development. In this study, we show that gp280 and gp330 are closely related proteins, as indicated by: 1) similarities in peptide maps obtained after cyanogen bromide cleavage, 2) immunological cross-reactivity related to a minor contingent of antibodies that do not have teratogenic activity, and 3) asynchronous but related expressions during ontogenesis. During the early stages of development, the expression of the two glycoproteins was limited to (gp330) or predominant in (gp280) the clathrin-coated pits and intermicrovillar areas. In the pre-implantation embryo, gp330 was expressed by trophectodermal cells, which became negative in day-6 embryos trapped in endometrial infoldings. At this stage, gp280 and gp330 were both simultaneously detectable at the apical pole of the first entoblastic cells and remained expressed by the brush border of visceral yolk sac epithelial cells until the end of pregnancy. In addition, gp330 was expressed by amniotic cells and neurectodermal structures. During nephrogenesis, in contrast, the expression of gp280 and gp330 by the intermicrovillar areas of the proximal tubule cell was the result of a complex maturation process. gp280 and gp330 were diffusely distributed in S-shaped bodies in the presumptive areas of the glomerulus, proximal tubule, and distal tubule (gp330). During development of the nephron, the pattern of expression became progressively restricted to the proximal tubule and glomerulus (gp330), and selective localization in the intermicrovillar areas was only achieved in filtrating nephrons.

Animals↗
PubMed1992

Teratogenic Agent Information Centre: fifteen years of counseling and pregnancy follow-up.

The Teratogenic Agent Information Centre was set up 15 years ago in response to a growing demand from a medical profession struggling to cope with the problem of teratogenic risk. Our goal was to provide information on the real nature of the risk and to monitor all at-risk pregnancies so as to obtain data in a field where there are still, unfortunately, many gaps in our knowledge. The results of these 15 years have been most encouraging, in that physicians have been provided with specialized information and the follow-up of gestations had provided considerable clinical data, which has contributed to advancing our understanding in this domain.

Counseling↗
PubMed1992

Low bone mineral density in patients with inflammatory bowel disease.

To assess the prevalence and risk factors for low bone mineral density in inflammatory bowel disease, we studied 61 consecutive patients, mean age 36 +/- 11 years. Twenty-seven had a Crohn's disease and 34 ulcerative colitis (including 13 with ileoanal anastomosis). Three patients, two women and one man (32, 70, and 45 years old, respectively) had vertebral crush fractures. Bone mineral density measured by dual energy x-ray absorptiometry at spine and femoral level was more than 2 SD below normal values in 23% of the patients, all of them having received steroid therapy. Eighteen patients (29%) had never received steroid therapy; their bone mineral density was not different than those who had. Univariate analysis showed a positive correlation between bone mineral density and body weight or oral calcium intakes, and a negative correlation with steroid daily dose. After ileoanal anastomosis, bone mineral density was not different from other groups and showed a positive correlation with time elapsed since coloproctectomy. We concluded that bone mineral density is low in patients with inflammatory bowel disease and exposes them to the risk of bone fracture. Bone mineral density after ileoanal anastomosis may increase with time after surgery.

Absorptiometry, Photon↗
PubMed1992

Coexpression in humans by kidney and fetal envelopes of a 280 kDa-coated pit-restricted protein. Similarity with the murine target of teratogenic antibodies.

Experimental studies performed in the rat over the last three decades have shown that antibodies raised against kidney or yolk sac, which, in the rat, surrounds the embryo and serves as a placenta during the major part of pregnancy, induced fetal resorptions or malformations. It is generally considered that the teratogenic antibodies decrease internalization and degradation of maternal proteins by yolk sac epithelial cells leading to an inadequate supply of nutriments to the embryo. These observations demonstrating the pathogenic role of antibodies to fetal envelopes are of great potential interest in clinical pathology since most cases of fetal malformations in humans are of unknown cause. The authors have recently shown that the key teratogenic antibodies in the murine system were directed against a 280 kDa-coated pit protein (gp280) specific for the brush border of epithelial cells lining the renal proximal tubule and the yolk sac. This observation allows for the unique opportunity to search for a similar system in humans. In this study, the presence in humans of a protein closely related to murine gp280 is shown, as indicated by extensive immunologic crossreactivity, close apparent molecular weights, strong homology of bidimensional peptide maps, and restricted distribution at the organ and subcellular level. In addition to kidney and yolk sac, human gp280 was also detected within the coated pits of the placental syncytiotrophoblastic cells. When introduced in an in vitro rat embryo culture system, antibodies to human gp280-induced developmental anomalies in a dose-dependent manner. These observations indicate that the antigenic component of the murine model is present in humans and can give rise to heterologous antibodies that cause developmental anomalies, suggesting that the experimental model might be of significance in human pathology.

Animals↗
PubMed1991

Hyperparathyroidism in proximal femur fractures biological and histomorphometric study in 21 patients over 75 years old.

Proximal femur fractures in elderly people are more and more frequent. Falls and senile bone disorders are the risk factors of this fracture. In order to understand the mechanisms of these bone disorders, we studied 21 consecutive patients with this fracture using bone histomorphometry. Measurements of serum intact parathormone (PTH), 25-(OH)-vitamin D, 1,25-(OH) 2-vitamin D and osteocalcin have been performed in these 21 patients, included in a larger series. We excluded patients with renal failure (serum creatinine greater than 140 mumols/l), cancer, or previous metabolic bone disease. There were 19 female and 2 male patients, ranging from 75 to 96 years, (mean 84.9). We found a low frequency of cortical (2/21) and trabecular (3/21) osteoporosis. There was no case of clearcut osteomalacia. Following histomorphometric bone study, two patients showed a typical pattern of hyperparathyroidism, and in a third one, this condition seemed very likely. In these three patients who were among the oldest, and who had high levels of serum PTH, chronic renal failure and primary hyperparathyroidism could be excluded. High bone remodeling was frequent in our patients, as reflected by the enhancement of eroded surfaces (13 cases) and of osteoid thickness (7 cases). Intact PTH level was elevated in our series compared to normal values in adults (in accordance to the PTH elevation in the case control study in a larger series). These findings suggest a major role of a secondary hyperparathyroidism in senile bone disorders favoring proximal femur fractures. This hyperparathyroidism is probably secondary to mild calcium and vitamin D deficiency. It may lead to architectural bone changes favoring this fracture.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Effect of clonidine on the circulation and vasoactive hormones after aortic surgery.

After completion of abdominal aortic graft, 29 patients received an i.v. infusion of placebo (n = 16) or clonidine 7 micrograms kg-1 (n = 13) over 120 min in a double-blind study. Cardiovascular variables were measured and plasma samples obtained up to 5 h after arrival in the recovery room, for assay of noradrenaline, adrenaline, vasopressin and renin concentrations. Noradrenaline, adrenaline and vasopressin concentrations decreased in the clonidine group throughout recovery (P less than 0.001, 0.05 and 0.05, respectively, vs placebo). Heart rate was less in the clonidine group (P less than 0.01). There was no significant difference in mean arterial pressure between groups. Stroke volume was larger (P less than 0.01) and there were fewer episodes of hypertension (P less than 0.05) and tachycardia in the clonidine group. In addition, a reduction in the number of circulatory interventions (P less than 0.05) and episodes of shivering was noted in the clonidine group. Mean (SD) postoperative volume requirements were larger in the clonidine group (total postoperative input: clonidine 1462 (604) ml; placebo 1064 (348) ml (P less than 0.05]. These data are consistent with the observation that clonidine modifies endocrine and circulatory status after major surgery.

Aorta, Abdominal↗