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Biomedical subjects

C Roux

Publications and source records attributed to C Roux.

At least 91 records · Page 5Linked to original sources
PubMed1999

Treatment of patients with Paget's disease of bone.

Paget's disease is a progressive bone disease, monostotic or polyostotic, characterised by hypertrophy of affected bones and accelerated disorganised bone remodelling. It results in bone deformities and pain, with a risk for articular and neurological complications, and fractures. The risk of complications, and thus the therapeutic decision, is a function of the age of the patient, and the severity and the activity of the disease. Bisphosphonates are first-line therapy for Paget's disease, and the advent of the new bisphosphonates permits a dramatic improvement in treatment. The optimal treatment regimen should obtain normalisation or quasi-normalisation of markers of bone remodelling. This result has the potential for a long-term control of the disease.

Biomarkers↗
PubMed1999

Oxidized derivatives of 7-dehydrocholesterol induce growth retardation in cultured rat embryos: a model for antenatal growth retardation in the Smith-Lemli-Opitz syndrome.

7-Dehydrocholesterol accumulates in fetuses affected by the Smith-Lemli-Opitz syndrome as a result of a deficit in the ultimate step of cholesterol synthesis catalyzed by Delta7 reductase. Rat embryos explanted at gestation day 10 and cultured for 48 h in the presence of the Delta7 reductase inhibitor AY 9944 were used as a model to discriminate between the beneficial effect of supplementation with cholesterol and the deleterious effect of supplementation with 7-dehydrocholesterol. Cholesterol supplementation in the form of mixed cholesterol/lecithin liposomes added to serum serving as the culture medium restores the growth of embryos which is markedly decreased in the presence of the inhibitor. 7-Dehydrocholesterol under identical conditions does not restore growth and impairs the beneficial effect of cholesterol added simultaneously. UV-photooxidation of 7-dehydrocholesterol-supplemented culture medium enhances its embryotoxicity, which suggests uptake by the embryo of toxic by-products formed from 7-dehydrocholesterol. By contrast photooxidation of cholesterol-supplemented culture medium does not induce embryotoxicity. alpha-Tocopherol reduces the toxicity of photooxidized 7-dehydrocholesterol supplementing the culture medium. We conclude that 7-dehydrocholesterol does not fulfill the cholesterol requirement of the developing embryos and exerts an additional embryotoxic effect probably via oxidized by-products. This could explain the antenatal growth retardation of SLOS by a blockage of the maternal compensatory cholesterol influx.

Animals↗
PubMed1999

[Quality control in bone densitometry].

Bone densitometry is a biological measurement which must comply to the usual rules of quality control. Calibration phantoms are available and must be regularly measured. Results may be interpreted by visual inspection or by estimating drift percentage. Different calculation methods have been proposed. A rigorous procedure is required when replacing densitometry devices. Simple and regular controls can assure the reliability of the technique.

Absorptiometry, Photon↗
PubMed1999

[Evaluation of post-menopausal osteoporosis using ultrasound].

Quantitative ultrasound (QUS) has recently been proposed for evaluating bone mineral density. Several QUS units are now commercially available. They measure both the attenuation and velocity of the US beam, in a transmission mode, mainly at the calcaneum and phalanges. These parameters are mainly related to bone density, but may also, in theory, be affected by non-quantitative properties of bone such as elasticity and anisotropy. Values measured at QUS are lowered in osteoporotic patients compared to normal control subjects. The predictive value for hip fracture in an elderly population is similar for QUS measurements and conventional techniques of bone mineral density measurements. The reproducibility of measurements with QUS is good, but the variation to be measured is only minimal. Thus, QUS cannot yet be recommended for follow up of patients or evaluation of response to treatment. Technical advances are to be expected. Because this technique is non-invasive and simple, it represents a promising tool for the screening of patients at risk for osteoporosis.

Aged↗
PubMed1999

Evaluation of the efficacy of etidronate therapy in preventing glucocorticoid-induced bone loss in patients with inflammatory rheumatic diseases. A randomized study.

The prevention and treatment of glucocorticoid-induced osteoporosis is a major concern for rheumatologists since inflammatory joint disease is among the most common reasons for long-term glucocorticoid therapy. We used a randomized placebo-controlled design to evaluate the efficacy of one-year cyclical etidronate therapy in preventing bone loss in 83 glucocorticoid-treated patients with rheumatoid arthritis, polymyalgia rheumatica, or giant cell arteritis. Glucocorticoid treatment duration was shorter than three months, and the starting dose was greater than 7.5 mg of prednisone-equivalent per day. Etidronate was given according to the standard cyclical schedule, i.e. 400 mg/d for periods of 14 days separated by 76-day intervals during which patients took 500 mg of supplemental calcium per day. The primary evaluation criterion was the change in lumbar spine bone mineral density after one year of etidronate therapy. Bone mineral density decreased by 1.94 +/- 0.61% in the placebo group and increased by 0.86 +/- 0.6% in the etidronate group, yielding a between-group difference of 2.8 +/- 0.86% (P = 0.002). The difference was largest in postmenopausal women (3.38 +/- 1.11%; P = 0.004). At the femoral neck, there was a smaller bone mineral density decrease in the etidronate than in the placebo group, but the difference (1.11 +/- 1.13%) was not statistically significant. The most common side effects were gastrointestinal symptoms and showed no difference between the two groups. Four fractures (including one vertebral fracture) occurred in the placebo group versus two (including one vertebral) in the etidronate group. Etidronate prevents glucocorticoid-induced lumbar spine bone loss in patients with rheumatoid arthritis, polymyalgia rheumatica, or giant cell arteritis.

Absorptiometry, Photon↗
PubMed1999

Osteoporosis, body composition, and bone turnover in ankylosing spondylitis.

OBJECTIVE: To study the prevalence of osteoporosis (OP) and osteopenia in ankylosing spondylitis (AS) and to investigate the relationship between symptomatic and structural severity, the indices of bone turnover, and body composition. METHODS: Eighty patients with AS were enrolled prospectively: 52 men (65%) and 28 women, mean age 36.7 years +/- 11.5 (range 18-67); they were studied clinically, radiologically, and by dual energy x-ray absorptiometry. Sixty-three underwent biological assessment of bone turnover markers. RESULTS: OP and osteopenia as defined by the World Health Organization (T score < -2.5 SD and between -1 and -2.5 SD, respectively) were observed in 15 (18.7%) and 25 patients (31.2%) at the lumbar spine and in 11 (13.7%) and 33 patients (41.2%) at the femoral neck, respectively. Patients with OP had a lower body mass index (BMI) and fat mass percentage. There was a trend to a lower disease duration in patients with OP at the spine than in healthy subjects. Bone resorption markers (urinary D-pyridinoline or C-telopeptide concentrations) were increased in 34 patients (53.9%). Bone turnover markers were positively correlated with C-reactive protein concentration and Larsen radiological hip score; they were negatively correlated with Schober index and fat mass percentage. CONCLUSION: (1) OP is frequent in AS and can be observed in early stages of the disease. (2) Patients with AS are more susceptible to develop OP when they have low BMI, low fat mass percentage, and active and severe disease. OP was observed in parallel with increased bone resorption.

Adolescent↗
PubMed1998

[Evaluation of osteoporosis with ultrasound].

FUNDAMENTAL PRINCIPLE: Ultrasound exploration is a new noninvasive technique for evaluating bone strength. In theory, ultrasound parameters vary with bone density, elasticity and microstructure. In clinical practice, bone density is the essential parameter. THEORETICAL BASIS: Several devices are now available for measuring the density of subcutaneous bones. The beam attenuation and velocity from the calcaneum are routinely recorded. DIAGNOSTIC VALUE: Bone density of the calcaneum has good diagnostic value for osteoporosis. Mean values in subjects with fractures are lower than in age-matched controls. Several prospective studies have demonstrated the predictive value showing a significant rise in the risk of femoral neck fractures in subjects with decreased sonographic measurements of the calcaneum. FOR FOLLOW UP: Currently, reproductibility is insufficient for individual follow-up. Ongoing technical advances, with the possibility of ultrasound imaging of the bones, will be useful for follow-up management.

Bone Density↗
PubMed1998

Partial ureteral duplication in an inverted Y with epididymal ureteric ectopia and intrasinusal ureteral junction.

Partial ureteral duplication in an inverted Y is evidenced by the presence of a ureter duplicated at a variable level before reaching the bladder, in either an orthotopic or an ectopic position. A case of ureteral duplication at the level of the renal hilum with opening of a ureter at the level of the epididymis is reported. The description of this original case is compared with the data in the literature. The stages of organogenesis of the superior excretory pathway leading to ureteral ectopia and ureteral anomalies of number are reviewed.

Abnormalities, Multiple↗
PubMed1998

Biochemical markers as predictors of bone mineral density changes after GnRH agonist treatment.

To evaluate bone biochemical markers as predictors of the efficacy of a hormone replacement therapy (HRT), we studied the bone changes induced by the cessation and return of ovarian function in 28 patients treated for 6 months with a GnRH agonist. This model reproduced the effects observed in postmenopausal women with high bone turnover treated with HRT. At the end of the treatment, Z scores were 1.8 +/- 0.3 for Crosslaps (CTx) and deoxypyridinoline (D-Pyr), and 1.1 +/- 0.2 for bone alkaline phosphatase (B-ALP) and osteocalcin (OC). This indicated an imbalance in bone remodeling with a high bone resorption. Bone mineral density (BMD) fell by 4.2 +/- 2.5%. The changes in BMD between the 6th and 12th months were 0. 34 +/- 2.24 and -1.73 +/- 3.25% at the lumbar spine and the femoral neck, respectively. Biochemical markers except urinary calcium and hydroxyproline measured at 6 months were positively correlated with the BMD changes at the lumbar spine. After the resumption of menstruation, 13 of 28 women displayed positive spine BMD changes between the 6th and 12th months; in this group, bone biochemical markers measured at 6 months were significantly higher (P = 0.02). Stepwise regression analysis showed that the association of B-ALP and D-Pyr measured at 6 months explained 40% of BMD variance and the association of B-ALP, PTH, and estradiol 56%. We conclude that measuring individual biochemical bone markers can help to predict the bone effect of an increase in the circulating estradiol in women with ovarian deficiency.

Adult↗
PubMed1998

Plantar flexion force is related to calcaneus bone ultrasonic parameters in postmenopausal women.

The aim of this report was to study the relationship between the plantar flexion strength produced by contraction of the triceps surae (gastrocnemii-soleus) muscle and the calcaneus bone parameters assessed by quantitative ultrasound in 45 healthy postmenopausal women. Plantar flexion strength was related to calcaneus broadband ultrasound attenuation (BUA) (r = 0.43, P = 0.003) and to speed of sound (SOS) (r = 0.3, P = 0.04). Plantar flexion appeared to predict ultrasonic properties, independently of body weight (R2 = 19% and 9% for BUA and SOS, respectively). These results suggest that the stresses related to locomotion locally enhance bone remodeling but further studies are needed to identify the respective role of the compressive strains related to ground reaction forces at heel-strike and the muscular tensile strains applied on the calcaneus where the calcaneal tendon is inserted.

Calcaneus↗
PubMed1998

Molecular analysis of the chromosomal equipment in spermatozoa of a 46, XY, t(7;8) (q11.21;cen) carrier by using fluorescence in situ hybridization.

The meiotic segregation of a balanced reciprocal translocation (7;8) (q11.21;cen) was analysed by interphase fluorescence in situ hybridization (FISH) on carrier spermatozoa. A dual interphase FISH technique was applied to 34,527 decondensed sperm heads with chromosome-7- and chromosome-8-specific alpha-satellite probes. Analysis with such probes was possible according to the cytogenetic characteristics of these translocation breakpoints, which implied a centromeric breakpoint. The majority of the analysed nuclei (56.70%) showed normal (30.40%) or balanced (26.30%) chromosomal equipment resulting from alternate segregation during meiosis. A total of 14,935 spermatozoa (43.26%) was unbalanced with a predominance of gametes resulting from adjacent-I (25.10%) or adjacent-II (11.10%) segregation; such gametes could produce partial mono- or trisomies at term. The frequency of analysed cells resulting from a 3:1 segregation, which could induce complete mono- and trisomies at term, was 7.06%; 0.04% of scored cells were diploid. The same dual-FISH technique was carried out either with chromosome-15- and chromosome-18-specific probes or with gonosome-specific probes, in order to detect a possible interchromosomal effect. A significant increase of disomic 18 spermatozoa was observed in the carrier. Such studies are not yet frequent. Multicolour-FISH seems a rapid and accurate tool for direct analyses of spermatogenetic segregation mechanisms in a carrier of balanced chromosomal abnormalities and provides interesting information for characterizing the possible risks for the offspring.

Adult↗
PubMed1998

Interindividual variations in the disomy frequencies of human spermatozoa and their correlation with nuclear maturity as evaluated by aniline blue staining.

OBJECTIVE: To evaluate the importance of interindividual variations in the disomy frequencies of human sperm and their possible correlation with the principal semen parameters. DESIGN: Prospective randomized analysis of sperm nuclei by fluorescence in situ hybridization and analysis of semen parameters. SETTING: University-based laboratory for reproductive biology. PATIENT(S): Fifty-seven human ejaculates selected at random from a population of men undergoing semen analysis. INTERVENTION(S): Semen specimens were analyzed, and sperm samples were prepared for fluorescence in situ hybridization. MAIN OUTCOME MEASURE(S): Semen parameters, including necrozoospermia, global motility, sperm concentration, multiple abnormalities index, and teratozoospermia were evaluated, aniline blue staining was completed, and disomy frequencies for chromosomes 8, 15, 18, X, and Y were determined using fluorescence in situ hybridization. RESULT(S): Noticeable differences in disomy frequencies between individuals were observed, and these frequencies were correlated with the degree of nuclear maturity. CONCLUSION(S): We hypothesize that the positive correlation can be explained by an abnormality of chromosomal segregation at the time of meiosis that would cause disturbances during the transition of nucleoprotein or by one or several premeiotic abnormalities of chromatin that would perturb both the meiotic process and the construction of definitive proteins.

Adult↗
PubMed1998

[Phylogeny of fungi responsible for smut of plants based on ITS sequence analysis].

Phylogenetic relationships among fungi belonging to the family of Ustilaginaceae (genera Microbotryum, Spacelotheca, Ustilago, Sporisorium) are inferred from a parsimony analysis using the ITS sequences of nuclear ribosomal genes. The introduction in the phylogeny of sequences from species of Suillus, Puccinia and Taphrina as outgroup shows the polyphyletism of this family. These results support the division of this taxon into two groups: Ustilaginaceae s. str. formed only by the pathogens of Poaceae, and Microbotryaceae constituted by the pathogens of Dicotyledons. Furthermore, we proposed to extend the host plant spectrum of Ustilaginaceae s. str. to all the Monocotyledons. Several discriminating characteristics are listed to support this distinction.

DNA, Plant↗
PubMed1998

Understanding coronary artery movement: a knowledge-based approach.

The aim of this paper is to describe a knowledge-based system that interprets three-dimensional (3D) coronary artery movement, using data from digital subtraction angiography image sequences. Dynamic information obtained from artery centerline 3D reconstruction and optical flow estimation, is classified according to experimental evidence indicating that artery displacements are quasi-homogeneous by a segment analysis. Characteristic motion features like displacement direction, perpendicular/radial components, rotation direction, curvature and torsion are qualitatively described from an image sequence using symbolic labels. These facts are then related and interpreted using anatomical-functional knowledge provided by a specialist, as well as spatial and temporal knowledge, applying spatio-temporal reasoning schemes. Facts, knowledge and reasoning rules are stated in a declarative form. Detailed examples of local and global interpretation results, using a real reconstructed angiographic biplane image sequence are presented in order to illustrate how our system suitably interprets coronary artery dynamic behavior.

Angiography, Digital Subtraction↗
PubMed1998

Identification of new early auxin markers in tobacco by mRNA differential display.

Differential display of mRNA has been improved by developing a two-step PCR amplification procedure. The modified differential display has been applied to identify early alterations of mRNA expression in response to auxin treatment of tobacco seedlings. This approach has led to the isolation of four fragments corresponding to auxin-up-regulated mRNAs. One, named GO15-13, shows significant homology with the 3' end of the coding region of the soybean SAUR X10A. The three other fragments present no homology with sequences available in the databases and constitute potential new early auxin markers.

Gene Expression Regulation, Plant↗
PubMed1998

Molecular cloning and expression of the early auxin-responsive Aux/IAA gene family in Nicotiana tabacum.

Early auxin-regulated tobacco cDNAs, belonging to the Aux/IAA gene family have been isolated by screening of a cDNA library prepared from auxin-treated suspension-grown etiolated seedlings of Nicotiana tabacum. The probes used were either RT-PCR fragments or an insert resulting from mRNA differential display selection. All of them possessed the structural features which characterize the Aux/IAA gene products. The auxin response of three distinct Nt-iaa subclasses has been characterized in terms of kinetics, dose-response and specificity as several plant hormones and chemicals have been tested for their ability to alter Nt-iaa mRNA accumulation. Differences of auxin responses have been observed between the Nt-iaa analysed, revealing significant differences of regulation. The effect of the protein synthesis inhibitor cycloheximide suggested that Nt-iaa2.3, Nt-iaa4.3 and strictly related genes can be classified as primary auxin-responsive genes and Nt-iaa28 as a late one. The steady-state mRNA level of these Nt-iaa has also been determined in organs of tobacco plants.

Amino Acid Sequence↗