Showing papers by "Paris Descartes University published in 2000"

EULAR recommendations for the management of knee osteoarthritis: report of a task force of the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT)

Abstract: BACKGROUND—Osteoarthritis (OA) is the most common joint disease encountered throughout Europe. A task force for the EULAR Standing Committee for Clinical Trials met in 1998 to determine the methodological and logistical approach required for the development of evidence based guidelines for treatment of knee OA. The guidelines were restricted to cover all currently available treatments for knee OA diagnosed either clinically and/or radiographically affecting any compartment of the knee. METHODS—The first stage was the selection of treatment modalities to be considered. The second stage comprised a search of the electronic databases Medline and Embase using a combination of subject headings and keywords. All European language publications in the form of systematic reviews, meta-analyses, randomised controlled trials, controlled trials, and observational studies were included. During stage three all the relevant studies were quality scored. The summary statistics for validated outcome measures, when available, were recorded and, where practical, the numbers needed to treat and the effect size for each treatment were calculated. In the fourth stage key clinical propositions were determined by expert consensus employing a Delphi approach. The final stage ranked these propositions according to the available evidence. A second set of propositions relating to a future research agenda was determined by expert consensus using a Delphi approach. RESULTS—Over 2400 English language publications and 400 non-English language publications were identified. Seven hundred and forty four studies presented outcome data of the effects of specific treatments on knee OA. Quantitative analysis of treatment effect was possible in only 61 studies. Recommendations for the management of knee OA based on currently available data and expert opinion are presented. Proposals for a future research agenda are highlighted. CONCLUSIONS—These are the first clinical guidelines on knee OA to combine an evidence based approach and a consensus approach across a wide range of treatment modalities. It is apparent that certain clinical propositions are supported by substantial research based evidence, while others are not. There is thus an urgent need for future well designed trials to consider key clinical questions.

The HIV-1 Viral Protein R Induces Apoptosis via a Direct Effect on the Mitochondrial Permeability Transition Pore

Abstract: Viral protein R (Vpr) encoded by HIV-1 is a facultative inducer of apoptosis. When added to intact cells or purified mitochondria, micromolar and submicromolar doses of synthetic Vpr cause a rapid dissipation of the mitochondrial transmembrane potential (ΔΨm), as well as the mitochondrial release of apoptogenic proteins such as cytochrome c or apoptosis inducing factor. The same structural motifs relevant for cell killing are responsible for the mitochondriotoxic effects of Vpr. Both mitochondrial and cytotoxic Vpr effects are prevented by Bcl-2, an inhibitor of the permeability transition pore complex (PTPC). Coincubation of purified organelles revealed that nuclear apoptosis is only induced by Vpr when mitochondria are present yet can be abolished by PTPC inhibitors. Vpr favors the permeabilization of artificial membranes containing the purified PTPC or defined PTPC components such as the adenine nucleotide translocator (ANT) combined with Bax. Again, this effect is prevented by addition of recombinant Bcl-2. The Vpr COOH terminus binds purified ANT, as well as a molecular complex containing ANT and the voltage-dependent anion channel (VDAC), another PTPC component. Yeast strains lacking ANT or VDAC are less susceptible to Vpr-induced killing than control cells yet recover Vpr sensitivity when retransfected with yeast ANT or human VDAC. Hence, Vpr induces apoptosis via a direct effect on the mitochondrial PTPC.

Opposite Effects of Androgens and Estrogens on Adipogenesis in Rat Preadipocytes: Evidence for Sex and Site-Related Specificities and Possible Involvement of Insulin-Like Growth Factor 1 Receptor and Peroxisome Proliferator-Activated Receptorγ 21

Abstract: To investigate the role of sex steroid hormones in adipose tissue development and distribution, we have studied the effect of various sex steroids (testosterone, dihydrotestosterone (DHT), and 17beta-estradiol) in vitro, on the proliferation and differentiation processes in rat preadipocytes from deep (epididymal and parametrial) and superficial (femoral sc) fat deposits. All added steroids failed to affect the growth rate of preadipocytes from male rats when determined from day 1 to day 4 after plating, whether FCS was present or not in the culture medium. In contrast, in preadipocytes from female rats, we observed a positive effect (x2) of 17beta-estradiol (0.01 microM) on the proliferative capacities of sc but not parametrial preadipocytes. When preadipocytes were exposed to testosterone or DHT (0.1 microM) during the differentiation process, the glycerol 3-phosphate dehydrogenase activity was significantly decreased in epididymal preadipocytes only. When preadipocytes from male rats were exposed to 17beta-estradiol (0.01 microM), the differentiation capacities of preadipocytes were not modified. However, in parametrial preadipocytes from ovariectomized female rats, 17beta-estradiol significantly increased (x1.34) the glycerol 3-phosphate dehydrogenase activity. In differentiated preadipocytes that had been exposed to sex steroids, expression of peroxisome proliferator-activated receptor gamma2 was up-regulated by 17beta-estradiol but not by androgens. As described in other cell types, sex steroids modulate insulin growth factor 1 receptor (IGF1R) expression in preadipocytes. Indeed, IGF1R levels were either enhanced by 17 beta-estradiol (0.01 microM) in sc preadipocytes from female ovariectomized rats or decreased by DHT (0.01 microM) in epididymal preadipocytes. These effects were reversed by simultaneous exposure to androgen or estrogen receptor antagonists. In conclusion, this study demonstrates that, in rat preadipocytes kept in primary culture and chronically exposed to sex hormones, androgens elicit an antiadipogenic effect, whereas estrogens behave as proadipogenic hormones. Moreover, our results suggest that these opposite effects could be related to changes in IGF1R (androgens and estrogens) and peroxisome proliferator-activated receptor gamma2 expression (estrogens).

Cardiac functional improvement by a human Bcl-2 transgene in a mouse model of ischemia/reperfusion injury.

Abstract: Background Apoptosis has been shown to contribute to myocardial reperfusion injury. It has been suggested that, in reducing the apoptotic component within the ischemic area at risk, Bcl-2 overexpression could lead to a ventricular function improvement. Methods Transgenic mice overexpressing the anti-apoptotic human Bcl-2 cDNA in heart were subjected to a 1-h left coronary artery occlusion followed by a 24-h reperfusion. At the end of the experiment, left ventricular function was assessed by two-dimensional echocardiography. After sacrifice, the area at risk (AR) and the infarct area (IA) were determined by Evans blue and triphenyltetrazolium chloride staining, respectively. The extent of apoptosis was assessed by the TUNEL method. Non-transgenic littermates served as controls. Results Baseline AR was not different between Bcl-2 transgenic mice and their wild-type littermates. In contrast, left ventricular ejection fraction was significantly improved in the transgenic mice line (61.25±4.0%) compared to non-transgenic littermates (43.2±5.0%, p<0.01). This functional amelioration was correlated with a significant reduction of infarct size in transgenic animals (IA/AR 18.51±3.4% vs 50.83±8.4% in non-transgenic littermates). Finally, apoptotic nuclei were less numerous in transgenic mice than in controls as quantified by TUNEL analysis (8.1±2.2% vs 20.6±4.4%). Conclusions Bcl-2 overexpression is effective in reducing myocardial reperfusion injury and improving heart function. This benefit correlates with a reduction of cardiomyocyte apoptosis. The apoptotic component of ischemia/reperfusion injury could therefore constitute a new therapeutic target in the acute phase of myocardial infarction. Copyright © 2000 John Wiley & Sons, Ltd.

Off label and unlicensed drug use among French office based paediatricians

Abstract: AIMS To determine the extent of off label and unlicensed drug use in French office based paediatric practice. METHODS A prospective one day survey of all written prescriptions, for patients under 15 years, among 95 office based paediatricians in the Paris, France metropolitan area. Main outcome measures were: comparison of the use of each drug with its product licence for age, indication, dose, and route of administration. RESULTS A total of 2522 prescriptions were administered to 989 patients; 844 (33%) were used either in an unlicensed (4%) or an off label (29%) manner. A total of 550 (56%) paediatric patients received one or more off label prescriptions. CONCLUSIONS Off label prescriptions (that is, outside the terms of the Summary of Product Characteristics) are widespread in office based paediatric practice, while unlicensed drug use is rare in our study. New regulations in the licensing process in Europe are needed to allow children to receive drugs that have been fully evaluated in their specific age group.

Transgenic mice carrying large human genomic sequences with expanded CTG repeat mimic closely the DM CTG repeat intergenerational and somatic instability

Abstract: Myotonic dystrophy (DM) is caused by a CTG repeat expansion in the 3'UTR of the DM protein kinase (DMPK) gene. A very high level of instability is observed through successive generations and the size of the repeat is generally correlated with the severity of the disease and with age at onset. Furthermore, tissues from DM patients exhibit somatic mosaicism that increases with age. We generated transgenic mice carrying large human genomic sequences with 20, 55 or >300 CTG, cloned from patients from the same affected DM family. Using large human flanking sequences and a large amplification, we demonstrate that the intergenerational CTG repeat instability is reproduced in mice, with a strong bias towards expansions and with the same sex- and size-dependent characteristics as in humans. Moreover, a high level of instability, increasing with age, can be observed in tissues and in sperm. Although we did not observe dramatic expansions (or 'big jumps' over several hundred CTG repeats) as in congenital forms of DM, our model carrying >300 CTG is the first to show instability so close to the human DM situation. Our three models carrying different sizes of CTG repeat provide insight on the different factors modulating the CTG repeat instability.

Distinction between coeliac disease and refractory sprue: a simple immunohistochemical method.

Abstract: Aims We recently showed that refractory sprue is distinct from coeliac disease, the former being characterized by abnormal intraepithelial T-lymphocytes expressing a cytoplasmic CD3 chain (CD3c), lacking CD3 and CD8 surface expression, and showing TCRγ gene rearrangements. To take advantage of the abnormal phenotype of CD3c + CD8 − intraepithelial lymphocytes (IEL) in refractory sprue we developed a simple method to distinguish coeliac disease from refractory sprue. Methods and results Comparative immunohistochemical studies using anti-CD3 and anti-CD8 antibodies were applied on paraffin-embedded and frozen biopsy specimens in refractory sprue (n = 6), coeliac disease (n = 10), healthy controls (n = 5) and suspected refractory sprue (n = 6). Comparable results were obtained on fixed and frozen biopsy specimens. In four of the six patients with suspected refractory sprue, abnormal CD3c + CD8 − IEL and TCRγ gene rearrangements were found, as in refractory sprue; the remaining two patients had normal (CD3 + CD8 +) IEL and no TCRγ gene rearrangements. Both patients had coeliac disease, as one failed to comply with a gluten-free diet, while the other was a slow responder. Conclusion This simplified immunostaining method using anti-CD3 and anti-CD8 antibodies on paraffin sections can distinguish active coeliac disease from refractory sprue and should prove useful in clinical practice.

The familial form of spondylarthropathy: A clinical study of 115 multiplex families

Abstract: Objective To investigate the interrelationships among different phenotypes, and their relationship to the HLA–B locus, in multiplex families with spondylarthropathy (SpA). Methods We recruited 115 white French families, each of which had at least 2 members with SpA. Pedigrees were established. Clinical data and pelvic radiographs were collected. The HLA–B27 status of all patients was determined. Analysis was performed to determine the prevalence of SpA manifestations according to sex, disease duration, and HLA–B status, and to examine clustering of specific manifestations in subsets of families. Results We identified 329 SpA patients. Mean ± SD age at onset was 24 ± 9.4 years. The male:female ratio was 186:143, or 1.3, with few sex differences in disease expression. Axial manifestations and HLA–B27 were each present in 97% of the patients. Inflammatory bowel disease and HLA–B35 were overrepresented in the 7 families containing HLA–B27-negative patients. The frequency of radiographic sacroiliitis increased in parallel with disease duration. Peripheral enthesitis, radiographic sacroiliitis, and psoriasis were evenly distributed in the families. Clustering independent of age was only observed for peripheral arthritis, suggesting that specific factors may predispose individuals to this manifestation. Conclusion Familial SpA appears to be homogeneous, based on the high frequencies of axial skeletal involvement and HLA–B27. The lack of clustering of most manifestations in families suggests that a predominant shared component, including HLA–B27, predisposes individuals to all forms of familial SpA, and that ubiquitous genetic or environmental factors contribute to phenotype diversity.

Outcome in patients with adrenal incidentaloma selected for surgery: an analysis of 88 cases investigated in a single clinical center

Abstract: Objective: The study was designed to evaluate the clinical, endocrinological and radiological parameters used to investigate adrenal incidentalomas and select patients for surgery. Design and Methods: An analysis of 88 consecutive patients with adrenal incidentaloma selected for surgery and investigated in a single clinical center was performed. Results: Mean (6 S.D.) age of the patients was 53614 years. Fourteen (16%) of the adrenal incidentalomas were malignant tumors (2 adrenocortical carcinomas, 3 metastases, 4 adenocarcinomas, 4 sarcomas and 1 mesenchymoma), 10 (11%) were pheochromocytomas, 32 (36%) were non-secretory benign adrenal adenomas and the remaining were benign adrenal (n a 8; 9%) or extraadrenal (n a 24; 27%) masses. Endocrinological investigations revealed 1 Conn adenoma, 4 tumors responsible for Cushing’s syndrome or silent hypercortisolism and 1 androgen secreting tumor. Abnormalities of endocrine evaluations were observed in the 2 malignant adrenocortical carcinomas. Elevated 24-h urinary metanephrine levels were observed in the 9 pheochromocytomas tested. Complications of surgery occurred in 14% of the cases. Regardless of the endocrine status, parameters associated with malignant tumors were: older age (mean age of patients harboring malignant tumors vs patients with benign incidentalomas: 62 6 17 years vs 52 6 13 years, P a 0.005), weight loss (39% vs 7%, P a 0.005), and mass diameter greater than 60 mm (69% vs 15%, P < 0.001). By multiple logistic regression analysis malignant tumors were associated with increased age, diameter greater than 60 mm and bilateral masses. Conclusion: This study points to a high rate of pheochromocytomas and malignant tumors in patients selected for surgery. This high rate differs from some previous reports and might be explained by the criteria used to select patients for surgery. Among these two groups of tumors, careful systematic endocrinological investigations allow the detection of altered secretion in the vast majority ‐ if not all ‐ malignant tumors of adrenal origin and pheochromocytomas. Only 5% of the incidentalomas below 30 mm selected for surgery in this study were malignant, in keeping with the use of this criteria as an important parameter to select patients with normal hormonal investigations for careful follow-up.

Three-dimensional model of the extracellular domain of the type 4a metabotropic glutamate receptor: new insights into the activation process.

Abstract: Metabotropic glutamate receptors (mGluRs) belong to the family 3 of G-protein-coupled receptors. On these proteins, agonist binding on the extracellular domain leads to conformational changes in the 7-transmembrane domains required for G-protein activation. To elucidate the structural features that might be responsible for such an activation mechanism, we have generated models of the amino terminal domain (ATD) of type 4 mGluR (mGlu4R). The fold recognition search allowed the identification of three hits with a low sequence identity, but with high secondary structure conservation: leucine isoleucine valine-binding protein (LIVBP) and leucine-binding protein (LBP) as already known, and acetamide-binding protein (AmiC). These proteins are characterized by a bilobate structure in an open state for LIVBP/LBP and a closed state for AmiC, with ligand binding in the cleft. Models for both open and closed forms of mGlu4R ATD have been generated. ACPT-I (1-aminocyclopentane 1,3,4-tricarboxylic acid), a selective agonist, has been docked in the two models. In the open form, ACPT-I is only bound to lobe I through interactions with Lys74, Arg78, Ser159, and Thr182. In the closed form, ACPT-I is trapped between both lobes with additional binding to Tyr230, Asp312, Ser313, and Lys317 from lobe II. These results support the hypothesis that mGluR agonists bind a closed form of the ATDs, suggesting that such a conformation of the binding domain corresponds to the active conformation.

Effects of capsaicin-induced sensory denervation on osteoclastic resorption in adult rats.

Abstract: Many recent findings suggest that the nervous system has efferent effects on bone. A putative role of the sensory innervation has been assessed by using a synchronised rat model of bone resorption after treating adult animals with the neurotoxin capsaicin. Fourteen days after capsaicin treatment (50 mg kg-1) the right maxillary molars were extracted to activate a wave of resorption along the mandibular cortex. The rats were killed 4 days later (i.e. at the peak of resorption in this model), and their right mandibles were processed for histometric evaluation of resorption along the cortex and of calcitonin gene-related peptide (CGRP)- and substance P (SP)-immunoreactive (IR) fibres in the dental pulp. CGRP-IR and SP-IR fibres were significantly reduced in numbers by the capsaicin treatment (by 58 and 49%, respectively), confirming the success of sensory denervation. The resorption surface was significantly reduced (P < 0.005) versus the sham-treated animals. Although the size of the osteoclast population recruited in the site was not modified, the number of actively resorbing osteoclasts was significantly reduced (P < 0.03). However, the activity of the resorbing cells was not modified. Non-specific esterase-positive osteoclast precursors were also significantly few after capsaicin treatment. These data show that the sensory nervous system is involved in the control of bone resorption at two different levels: (1) in the recruitment of osteoclast precursors, and (2) in regulating the access of recruited cells to the bone surface.

Comparison of the responsiveness of symptomatic outcome measures in knee osteoarthritis.

Abstract: Objective A number of international scientific societies have recommended a core set of domains to be systematically assessed in clinical research studies on osteoarthritis (OA), i.e., pain, function, and patient's overall assessment. This open, longitudinal, observational study compares the responsiveness of different symptomatic variables evaluating these 3 domains in knee OA. Methods Patients were individuals with painful knee OA. The collected data were Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale (0-100) and WOMAC function subscale (0-100), Lequesne's index (0-100), pain after physical activities (visual analog scale [VAS] 100 mm), and patient's global assessment (VAS 100 mm). The procedure used was knee joint lovage. Time of collection was before and 1, 3, and 6 months after the lavage. Analysis was by comparison of the standardized response mean (mean of the changes/SD of the changes) in an intent-to-treat strategy after 1, 3, and 6 months using the jackknife method. Results Improvement in all dimensions of WOMAC subscale scores and VAS scores was observed at month 1. Lequesne's index was not responsive to change. The standardized response mean was moderate, ranging from 0.00 to 0.40. Comparison of the estimates of the standardized response means using the jackknife method showed a statistically significant difference between Lequesne's index and the WOMAC subscale for function, but not between VAS pain and the WOMAC subscale for pain. Conclusion Most of the evaluated variables have a moderate responsiveness. In knee OA, the WOMAC function scale seems to be more sensitive than Lequesne's index for detecting changes after symptomatic therapy.

ARP1 in Golgi organisation and attachment of manchette microtubules to the nucleus during mammalian spermatogenesis.

Abstract: Actin related protein of vertebrate, Arp1, is a major component of the dynactin complex. To characterise and localise Arp1 during mammalian spermatogenesis, polyclonal antibodies were raised against a human recombinant Arp1. Anti-Arp1 antibodies were used for western-immunoblotting, indirect immunofluorescence and immunoelectron microscopy. In round spermatids, Arp1 was detected at the centrosome and at the Golgi apparatus. In elongated spermatids, Arp1 was predominantly found along microtubules of the manchette and at their site of attachment to the nuclear envelope. In maturing spermatids, Arp1 was still present in the pericentriolar material, but in testicular spermatozoa it was not detectable. These various localisations of Arp1 and their changes during spermatid differentiation suggest that the dynactin complex in association with dynein might contribute to several activities: the functional organisation of the centrosome and of the Golgi apparatus and the shaping of the nucleus by manchette microtubules.

Food protein-induced enterocolitis syndrome: laboratory perspectives.

Abstract: The expression of food protein allergy in man is very heterogeneous, varies with the age of the subject and is to a certain extent genetically determined. Skin prick tests with standardized food extracts are a sensitive method for detection of immunoglobulin E bound to reactive cells such as mast cells. Various tests on cellular immunity have been developed, especially because T-cell mediated reactions are considered to play a role in mainly delayed gastrointestinal reactions to cow's milk proteins. Food allergy may involve the entire gut, from mouth to rectum, including the esophagus. Abnormalities in intestinal permeability are the hallmarks of the inflamed gut, and may contribute to diagnosis of food induced enteropathy. What determines the characteristics of the intestinal inflammatory response is largely the cytokine responses triggered by the pathologic mechanism, whatever its origin, in the stomach, the small intestine, and the colon. A so-called T-helper type 2 response is characteristic of the allergic subject. A secretion of tumor necrosis factor-α alpha by blood cells of children allergic to milk was shown. All means of investigation may help in analyzing food substitutes for allergic infants.

Ocular cell transfection with the human basic fibroblast growth factor gene delays photoreceptor cell degeneration in RCS rats

Abstract: Based on the K8/JTS-1-mediated transfection technique, we developed an in vivo protocol for an efficient transfer of plasmid DNA to ocular cells. As determined with condensed plasmids containing reporter genes for either b -galactosidase (pcDNA-lacZ) or enhanced green fluorescent protein (pREP-EGFP), the immortalized human retinal epithelial cells RPE D407 and human embryonic kidney 293 cells can be transfected with typical efficiencies of 11 and 19%, respectively. Unlike 293 cells, RPE D407 cells had a reduced viability on transfection with both plasmids. In vivo, subretinal injections of DNA-K8/JTS-1 complexes revealed reporter gene expression in choroidal and RPE cells of normal pink-eyed Royal College of Surgeons (RCS) rats. The validity of this transfection technique in terms of retinal cell survival in RCS rats was then examined by using pREP-hFGF2 plasmid, which encodes the human basic fibroblast growth factor isoforms (hFGF2). Subretinal injection of pREP-hFGF2-K8/JTS-1 complexes into 3-week-old dystrophic RCS rat eyes reveals a delayed photoreceptor cell degeneration 60 days postinjection. In this case, the average analyzed field points with delayed cell dystrophy represent 14 to 17% of the retinal surface as compared with 2.6 and 4% in pREP5 b and vehicle-injected eyes, respectively. Peptide-mediated in oculo transfection thus appears to be a promising technique for the treatment of retinal cell and photoreceptor degenerations.

Autosomal dominant type IIa hypercholesterolemia: evaluation of the respective contributions of LDLR and APOB gene defects as well as a third major group of defects.

Abstract: Autosomal dominant type IIa hypercholesterolaemia (ADH) is characterised by an elevation of total plasma cholesterol associated with increased LDL particles. Numerous different molecular defects have been identified in the LDL receptor (LDLR) and few specific mutations in the apolipoprotein B (APOB) gene resulting in familial hypercholesterolaemia and familial defective apoB-100 respectively. To estimate the respective contribution of LDLR, APOB and other gene defects in this disease, we studied 33 well characterised French families diagnosed over at least three generations with ADH through the candidate gene approach. An estimation of the proportions performed with the HOMOG3R program showed that an LDLR gene defect was involved in approximately 50% of the families (P = 0.001). On the other hand, the estimated contribution of an APOB gene defect was only 15%. This low estimation of ADH due to an APOB gene defect is further strengthened by the existence of only two probands carrying the APOB (R3500Q) mutation in the sample. More importantly and surprisingly, 35% of the families in the sample were estimated to be linked to neither LDLR nor APOB genes. These data were confirmed by the exclusion of both genes through direct haplotyping in three families. Our results demonstrate that the relative contributions of LDLR and APOB gene defects to the disease are very different. Furthermore, our results also show that genetic heterogeneity is, generally, underestimated in ADH, and that at least three major groups of defects are involved. At this point, the contribution of the recently mapped FH3 gene to ADH cannot be assessed nor its importance in the group of 'non LDLR/non APOB' families.

Retinoids stimulate leptin synthesis and secretion in human syncytiotrophoblast.

Abstract: The syncytiotrophoblast (ST), which forms the outer layer of the chorionic villi, is the endocrine unit of the human placenta. Bathing in the maternal blood of the intervillous space, the ST secretes its hormonal products directly into the maternal circulation. Leptin is expressed in the ST and is secreted into the maternal circulation. However, its regulation and physiological role during pregnancy remain poorly known. In the present work we used the in vitro model of human cytotrophoblast differentiation into ST to study the effect of physiological and synthetic retinoids on leptin synthesis and secretion. Using specific antibodies we first illustrated by immunocytochemistry the expression of retinoic acid (RA) receptor α and retinoid X receptor α (RXRα) in ST. We then observed that leptin messenger ribonucleic acid and protein expression increased with in vitro ST formation. The 9-cis isomer of RA and the synthetic retinoid specific for RXRs (BMS 649) stimulated leptin messenger ribonucleic acid expres...