Calcium supplementation for the prevention and treatment of osteoporosis.
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Bone Density↗
Biomedical subjects
C Roux
Publications and source records attributed to C Roux.
[Urethral prolapse in young girls: a rare pathology in pediatric surgery. Our experience apropos of 22 cases observed at the Cocody and Yopougon University Hospitals].
Twenty-two cases of prolapse of the urethral mucosa, a benign affection mainly encountered in young black girls, were observed over a 9-year period (1983-1992). This pathology is still poorly understood and the aetiology has not been clearly determined. Treatment protocols, medical and surgical, vary. We prefer exeresis of the prolapsed mucosa, followed by suture. The results have been quite satisfactory.
Child↗
[Nephroblastoma at the hospital unit in Abidjan. Apropos of 60 cases].
A series of 60 cases of nephroblastoma treated at the Abidjan University Hospital from 1971 to 1981 were reported. Nephroblastoma is a frequent childhood tumour representing 26.40% of malignant childhood tumours. It is a tumour of the young child. There is no sex predominance and both sides are equally involved. The tumour is the only clinical manifestation and is always palapable. Factors of poor prognosis were often observed in our patients including: age less than 2 years with major tumour volume (56.6%), advanced stage (89.3%). Antimitotic treatment was used in all cases and in 16 surgery was required. The poor prognosis criteria observed in this series explain the poor outcome in most of the cases.
Adolescent↗
Computer vision approaches for the three-dimensional reconstruction of coronary arteries: review and prospects.
The objective of this article is to define the different stages involved in the 3D reconstruction of arteries and to review, from our experience and from the literature, the solutions already proposed. A full reconstruction framework includes the characterization of the imaging device (in terms of distortion and calibration), the specificity of the image acquisition process, the preprocessing that can be applied, the detection of the vascular structures, the 2D feature formation, the reconstruction itself, and the visualization aspects. They are examined according to a computer vision approach where two or three views are assumed to be available. Their generalization to temporal image sequences are also considered. Some of the material reported here is unpublished. The article allows the reader to identify the true critical issues that are not often clearly mentioned in the literature and the challenges that they convey. A final discussion presents a few perspectives in this area of research.
Artificial Intelligence↗
Antibodies to the 280-kd coated pit protein, target of teratogenic antibodies, produce alterations in the traffic of internalized proteins.
Previous studies have identified two high-molecular weight (280 and 330 kd) glycoproteins expressed by coated pits of the proximal renal tubule and yolk sac and have further established that, in vivo, antibodies to gp280 but not to gp330 induce fetal malformations. In the present study, we report the effect of these antibodies on the endocytic process by yolk sac visceral epithelial cells of rat embryos explanted at day 10 of gestation. Antibodies to gp280 markedly altered development of the yolk sac and embryo, induced malformations, inhibited by 40% the uptake of [14C] sucrose and perturbed the intracellular traffic of internalized proteins. Under control conditions, rat immunoglobulin G present in the culture medium was immunolocalized in lysosomes of epithelial cells, whereas in the presence of antibody, it was detected in small vesicles scattered through the apical cytoplasm. Alterations of the endocytic pathway were confirmed by experiments analyzing the uptake of peroxidase added to the medium for 2 to 60 minutes. The initial compartments of endocytosis visualized by peroxidase were increased in size and abnormal in shape and the transfer of the internalized peroxidase to the lysosomal compartment was delayed. In contrast, antibodies to gp330 had a minimal effect on embryonic development and did not induce fetal malformations. Endocytosis was only modestly altered; uptake of [14C] sucrose was decreased by 25%, and only minor modifications of the intracellular transit of peroxidase could be detected. We suggest that the key role of anti-gp280 antibodies is via trapping of the target antigen in the early endocytic compartment thus preventing its normal function in lysosomal transfer.
Animals↗
[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↗
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↗
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↗
Pseudovisceral pain referred from costovertebral arthropathies. Twenty-eight cases.
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Female↗
[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↗
[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↗
[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↗
[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↗
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↗
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↗
Long-lasting dermatological lesions after tiludronate therapy.
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Adrenal Cortex Hormones↗
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↗
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↗