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Biomedical subjects

M Revel

Publications and source records attributed to M Revel.

At least 55 records · Page 3Linked to original sources
PubMed2000

The ability of the Cochin rheumatoid arthritis hand functional scale to detect change during the course of disease.

OBJECTIVE: To assess changes measured with the Cochin rheumatoid arthritis (RA) hand functional disability scale during the course of the disease. METHODS: A cohort study evaluating outcome measure responsiveness in RA was conducted in a referral center. Ambulatory or hospitalized patients with RA according to the 1987 American College of Rheumatology (formerly the American Rheumatism Association) criteria were evaluated twice. Clinical measures included Cochin's scale, Revel's functional index, hand functional index, visual analog scale of patient-perceived handicap, visual analog scale of pain in hands and wrists, total score of swelling, total score of tenderness, and morning stiffness duration. Responsiveness was assessed by the effect size (ES) and the standardized response mean (SRM). The nonparametric Spearman rank correlation coefficient (r) was used to assess the correlation between two quantitative variable changes. RESULTS: Fifty-five patients (44 women) were evaluated twice at an interval of 15.4 +/- 1.4 months (mean +/- SD) (range 13-18 months). The Cochin scale total score had worsened at the second visit (95% confidence interval for mean differences -5.16, 0.73). Its SRM and ES values were -0.20 and -0.15, respectively. Changes in the score had the highest correlation (r = 0.58) with changes in the patient-perceived handicap, while it had only fair or little correlation with changes in the disease activity measures. The factor 2 scale subscore significantly worsened and had the highest values of SRM and ES (SRM = -0.40 and ES = -0.31). CONCLUSION: The Cochin scale can detect small but meaningful changes in RA hand disability.

Activities of Daily Living↗
PubMed2000

Monolayer anulus fibrosus cell cultures in a mechanically active environment: local culture condition adaptations and cell phenotype study.

Intervertebral disc cells can be cultured in vitro. Several culturing systems in a mechanically active environment have been developed to study the relationship between mechanical stimulations and biochemical events. The aim of this study was to assess the phenotype of rabbit intervertebral disc cells from the anulus fibrosus (AF) region cultured on flexible substrate before and after application of cyclic tensile stretch (CTS) and to control culture conditions during application of CTS. CTS was applied with a pressure-operated instrument, inducing the deformation of flexible-bottomed culture plates (Flexercell) at 20% and 5% stretch, at a frequency of 1 Hz, during 30 minutes to 24 hours. A significant decrease in culture medium volume and temperature was observed (52% and 2.1 degrees C at 20% stretch and 24 hours' application of CTS). These phenomena were inhibited by adding culture medium around culture wells and by a culture medium temperature control system. Like AF cells cultured in plastic wells, AF cells cultured on flexible substrate expressed collagen type II, but collagen type I mRNA was not detected. In both culture conditions, neosynthesized proteoglycans had the same aggregating properties. CTS at 20% stretch during 12 hours did not induce cell detachment from the substrate and did not modify aggregating properties of neosynthesized proteoglycans; AF cells continued to express collagen type II but not collagen type I mRNA. In conclusion, the Flexercell system appears to be appropriate for studying, at the cellular level, the metabolic responses to CTS.

Adaptation, Physiological↗
PubMed2000

Sensitivity of anulus fibrosus cells to interleukin 1 beta. Comparison with articular chondrocytes.

STUDY DESIGN: Anulus fibrosus cells from rabbits were grown in primary culture 1) to study their ability to produce prostaglandin E2 and Type II phospholipase A2, and to express stromelysin-1 messenger ribonucleic acid; and 2) to study the effect of interleukin 1 beta on this production and on proteoglycan aggregation. OBJECTIVES: To investigate the potency of anulus fibrosus cells to respond to interleukin 1 beta by producing degradative and inflammatory agents as compared with the potency of articular chondrocytes in the same animal. SUMMARY OF BACKGROUND DATA: Interleukin 1 beta has been implicated in the degradation of intervertebral discs. The way anulus fibrosus cells differ from articular chondrocytes in their responses to interleukin 1 beta remains to be established. METHODS: Anulus fibrosus cells and articular chondrocytes were obtained from young rabbits, grown in primary culture, and incubated with interleukin 1 beta. The newly synthesized proteoglycan was measured by labeling with [35S]-sulfate. Proteoglycan aggregation was analyzed by the elution profile on Sepharose 2B columns. The contents of collagen Type II and stromelysin-1 messenger ribonucleic acid were assessed by Northern blot analysis. The Type II phospholipase A2 activity was measured using a fluorometric substrate. Prostaglandin E2 production was evaluated by radioimmunoassay. RESULTS: Anulus fibrosus cells had 2.5-fold less Type II collagen messenger ribonucleic acid than articular chondrocytes, and interleukin 1 beta had no significant effect on this. Anulus fibrosus cells synthesized and secreted four-fold less proteoglycan than articular chondrocytes. Interleukin 1 beta reduced the anulus fibrosus content of total [35S]-sulfated proteoglycan by 35% (P < 0.01), and that of articular cells by 41% and decreased proteoglycan aggregation. Interleukin 1 beta induced the production of stromelysin-1 messenger ribonucleic acid in both cell types. The stromelysin-1 messenger ribonucleic acid content of anulus fibrosus cells was one half that of articular cells. Interleukin 1 beta increased the production of prostaglandin E2 and caused a dose-dependent secretion of Type II phospholipase A2 activity in both cell types. Its effect was 2.5-fold lower in anulus fibrosus cells than in articular chondrocytes. CONCLUSION: Anulus fibrosus cells can be stimulated by interleukin 1 beta to produce factors implicated in local degradative and inflammatory processes. This production is associated with decreased proteoglycan aggregation. Anulus fibrosus cells respond slightly less well to interleukin 1 beta in vitro than do articular cells.

Animals↗
PubMed2000

Ongoing research on mammalian cloning and embryo stem cell technologies: bioethics of their potential medical applications.

Reproduction by cloning has been achieved by transfer into enucleated oocytes of nuclei from embryonic cells and more recently from cells of adult animals. The efficiency at which embryos produced by such nuclear transfers will develop into healthy newborns is very low but has succeeded in producing some cloned bovines, ovines and mice. Since the first report of sheep cloning from an adult cell in 1997, the potential applications of reproductive cloning in human medicine have been envisaged amidst a flurry of moral debates. Although the technology is still far from being ready for any human use, it has been condemned up front. It has also led to irrational fantasies and fears, based mainly on the misconception that genetic identity means identical twin personalities. Scientific research is ongoing to refine the cloning technology for applications in the production of genetically homogeneous farm animals with useful nutritional or therapeutic genetic traits. A new area of research is non-reproductive therapeutic cloning for the purpose of producing autologous embryonic cells and tissues for transplantation.

Animal Husbandry↗
PubMed2000

Research on animal cloning technologies and their implications in medical ethics: an update.

Reproduction by cloning has been achieved by transfer into enucleated oocytes of nuclei from embryonic cells and more recently from cells of adult animals. The efficiency at which embryos produced by such nuclear transfers will develop into healthy newborns is very low but has allowed to produce some cloned bovines, bovines and mice. Since the first report of sheep cloning from an adult cell in 1997, the potential applications of reproductive cloning in human medicine have been envisaged amidst a flurry of moral debates. Although the technology is still far from being ready for any human use, it has been condemned from the outset. It has also led to irrational fantasies and fears mainly based on the misconception that genetic identity means identical twin personalities. Scientific research is ongoing on refining the cloning technology for applications in the production of genetically homogeneous farm animals with useful nutritional or therapeutic genetic traits. A new area of research is non-reproductive therapeutic cloning for the purpose of producing autologous embryonic cells and tissues for transplantation.

Adult↗
PubMed2000

Frozen shoulder.

Stiffness is a consistent but nonspecific symptom of primary frozen shoulder, a condition defined by restriction of passive motion in all planes without glenohumeral abnormalities on plain radiographs. Since the first description by Duplay in 1872, theories and descriptions of the lesions have varied over time and across authors, with the main target of the condition being reported as the subacromial bursa in some studies and the rotator interval in others. Recent publications have pointed out similarities with Dupuytren's contracture. Magnetic resonance imaging has helped to understand the lesions by showing a specific pattern of postgadolinium enhancement during the first few months after symptom onset. Pain relief is the main objective of therapy. Oral medications have not been adequately evaluated, with the exception of glucocorticoids, which hasten the resolution of nighttime pain to a modest degree. Intra-articular glucocorticoid injections are effective and are best performed under arthrographic control. It has been suggested that intra-articular glucocorticoid injections should be combined with joint capsule distension. An additional injection into the subacromial bursa has been found useful in patients with refractory pain. Motion range recovery is not always complete after 18 to 24 months and can be improved by physiotherapy. Methodological difficulties have precluded demonstration in formal studies of the undeniable benefits of physiotherapy. Joint capsule distension, and even more so arthroscopic capsulotomy with gentle mobilization, have provided promising results in patients with persistent stiffness, although the optimal time for performing these techniques remains to be determined.

Bursitis↗
PubMed1999

[Adhesive capsulitis of the shoulder].

Adhesive capsulitis is a painful stiff shoulder due to the thickening of the capsule and synovium. The main observed changes are hyperhaemia of the synovium and a capsular fibrosis similar to that of Dupuytren's disease. Stiffness involves mainly flexion, lateral rotation and abduction. In most cases, a spontaneous healing is observed within 12 to 30 months. When the capsulitis is disabling and pain still present, a joint distension followed by rehabilitation can be indicated. When the disability is important and mainly due to stiffness, a manipulation under anesthesia with or without arthroscopic release of soft tissues can be indicated.

Bursitis↗
PubMed1999

Induction of myelin gene expression in Schwann cell cultures by an interleukin-6 receptor-interleukin-6 chimera.

Expression of myelin basic protein (MBP) and Po gene products is induced during the final postnatal maturation of Schwann cells and reinduced during nerve regeneration. We show that a chimeric protein containing interleukin-6 fused to its soluble receptor (IL6RIL6 chimera) induces MBP and Po RNAs and proteins in cultures of dorsal root ganglia (DRG) from 14 day old mouse embryos. Activation of gp130 signaling by IL6RIL6 appears comparable to cyclic AMP elevating agents to induce the myelin gene products in DRG and in pure Schwann cell cultures.

Animals↗
PubMed1999

The soluble interleukin-6 (IL-6) receptor/IL-6 fusion protein enhances in vitro maintenance and proliferation of human CD34(+)CD38(-/low) cells capable of repopulating severe combined immunodeficiency mice.

In vitro maintenance and proliferation of human hematopoietic stem cells is crucial for many clinical applications. Early hematopoietic cells express low levels of FLT-3 and c-kit receptors, as well as the interleukin-6 (IL-6) receptor signal transducing element, gp130, but do not express IL-6 receptor itself. Therefore, we have attempted to maintain human cord blood or bone marrow CD34(+) cells ex vivo in serum-free cultures containing stem cell factor (SCF) and FLT-3 ligand (FL) alone or together with a new recombinant molecule of soluble IL-6 receptor fused to IL-6 (IL6RIL6 chimera). The effect of IL6RIL6 chimera on the proliferation and differentiation of CD34(+) cells was compared with that of each chimera component added separately. The engraftment potential of in vitro-cultured cells was determined using our recently established functional in vivo assay for primitive human severe combined immunodeficiency (SCID)-repopulating cells (SRC). We report here that IL6RIL6 chimera induced significantly higher levels of progenitors and SRC compared with SCF + FL alone or together with IL-6 and soluble IL-6 receptor. IL6RIL6 chimera prolonged in vitro maintenance of SRC for up to 14 days. Stimulation of CD34(+)CD38(-/low) enriched cells with IL6RIL6 chimera maintained the early CD34(+)CD38(-/low) cell subpopulation, which could be detected in vitro for up to 14 days. Moreover, IL6RIL6 chimera preferentially stimulated the growth of early CD34(+)38(-/low) cells, resulting in significantly higher levels of progenitors compared with more mature CD34(+)38(+) cells. Taken together, these findings demonstrate the importance of IL6RIL6 chimera in stimulating the proliferation of early CD34(+). CD38(-)gp130(+)IL-6R(-) cells in vitro and extended maintenance of progenitors and SRC.

Animals↗
PubMed1999

Phenotypic characteristics of rabbit intervertebral disc cells. Comparison with cartilage cells from the same animals.

STUDY DESIGN: Intervertebral disc cells were extracted from the surrounding matrix, and their metabolic activities and phenotypes were studied. OBJECTIVES: To compare the metabolic activities and phenotypes of cell populations extracted from the intervertebral discs of young rabbits with those of articular and growth plate chondrocytes from the same animals. SUMMARY OF BACKGROUND DATA: The phenotype of intervertebral disc cells has been poorly studied and still is debated. METHODS: The intervertebral discs as well as articular and vertebral growth plate cartilage of rabbits were digested enzymatically. The morphology of freshly isolated cells was examined. Their contents of collagen II and X mRNAs were determined by Northern blot analysis, and their sulfation activity by 35S-sulfate incorporation as chondrocytic markers. Cells were cultured at high density or low density and grown in primary culture. The stability of their phenotype was monitored by evaluating the collagen I and II mRNA ratio. The proteoglycans newly synthesized by the cells also were quantified, and their elution profile analyzed on Sepharose 2B columns. RESULTS: The anulus fibrosus cells were morphologically undistinguishable from articular chondrocytes. The nucleus pulposus contained mainly large vacuolated cells and a few smaller cells. All freshly extracted cells expressed different levels of collagen II mRNA. Anulus fibrosus and nucleus pulposus cells contained, respectively, 22% and 8% of collagen II mRNA compared with that found in articular or growth plate chondrocytes from the same animal. Only growth plate chondrocytes expressed collagen X. When anulus fibrosus cells were incubated for 48 hours at high density, they had collagen II mRNA contents similar to those of articular and growth plate chondrocytes, but synthesized five to six times fewer sulfated proteoglycans. When seeded at low density, anulus fibrosus cells divided more slowly than articular chondrocytes and incorporated four times fewer 35S-sulfate into proteoglycans. Their collagen II mRNA content was 2.75-fold lower than that of chondrocytes, and the procollagen alpha 1II/alpha 1I mRNA ratio was 3.1 for anulus fibrosus cells and 7 for chondrocytes. No collagen X mRNA was detected. When incubated for 48 hours at high density, the nucleus pulposus giant cells had four times less collagen II mRNA content than cartilage cells but synthesized the same amounts of sulfated proteoglycans. They did not divide during 21 days in culture and still contained collagen II mRNA but no collagen X mRNA. CONCLUSIONS: Findings showed that intervertebral disc cells all express cartilage-specific matrix proteins with quantitative differences, depending on their anatomic situation. It is suggested that anulus fibrosus cells are chondrocytic cells at a different stage of differentiation than articular and growth plate chondrocytes. The phenotype of nucleus pulposus cells still is unclear. They could be chondrocytic or notochordal. A definitive answer to this important question requires differentiating markers of notochordal cells.

Animals↗
PubMed1999

Cross-sectional study of weight-bearing activity on proximal femur bone mineral density.

In this cross-sectional study we investigated the effect of compressive and tensile forces applied on the proximal femur during weight-bearing activities. Ninety-seven men (29.9 +/- 1.7 years) were divided into two groups: 69 exercisers who had practiced regular high-impact weight-bearing activities for at least 5 years and 28 controls who had been sedentary for at least 5 years. The maximum isometric hip abduction strength was measured. The bone mineral density (BMD) of the femoral neck and the greater trochanter was assessed using dual-energy X-ray absorptiometry (DXA). Controls were considered as the reference population to calculate the Z score. Mean BMD values of the femoral neck were 0.97 g/cm2 on both sides in the exercisers and 0.83 g/cm2 on the right side and 0.84 g/cm2 on the left side in the controls. Mean BMD values of the greater trochanter were 0.86 g/cm2 on the right side and 0.87 g/cm2 on the left side in the exercisers, 0.73 g/cm2 on the right side and 0.72 g/cm2 on the left side in the controls. The BMD was significantly higher in exercisers at both trochanteric and cervical sites (P = 0. 0001). Both left and right hip abduction strength was significantly greater in the exercisers than in the controls (P < 0.05) and was positively correlated to cervical and trochanteric BMD (P < 0.01). In the exerciser group, the trochanteric Z score was higher than the cervical Z score at both right (P = 0.06) and left (P = 0.002) sides. Therefore, the proximal femoral BMD was significantly greater in exercised subjects as compared with sedentary controls. The difference was observed at the level of both the femoral neck (where it is known anatomically that only compressive gravitational forces are exerted) and the greater trochanter (where it is known that tensile forces are exerted). This result suggests the participation of both compressive and tensile forces in the mechanisms by which exercise influences bone trophicity.

Adult↗
PubMed1999

Involvement of receptor-bound protein methyltransferase PRMT1 in antiviral and antiproliferative effects of type I interferons.

Protein arginine N-methyltransferase (PRMT1) is one of the proteins that bind to the intracytoplasmatic domain of the IFNAR-1 chain of the type I interferon (IFN) receptor system. The attachment is specific and is not seen with PRMT2, another member of this protein family. Antisense PRMT1 cDNA constructs expressed under the early cytomegalovirus (CMV) promoter were transfected into HeLa cells, and stable transformants were selected. Antibodies to PRMT1 were used to identify clones with reduced PRMT1 expression. In such clones, IFN-beta inhibited three to five times less the replication of vesicular stomatitis virus (VSV) than in the original HeLa cells. The antiproliferative effect of IFN-beta was also reduced up to fivefold in the clones with low PRMT1 expression. No difference was seen when IFN-gamma was used alone to inhibit cell growth. The protein methylating enzyme, bound to IFNAR-1, appears to regulate positively the biologic activity of type I IFN.

Antisense Elements (Genetics)↗
PubMed1998

Capacity of the clinical picture to characterize low back pain relieved by facet joint anesthesia. Proposed criteria to identify patients with painful facet joints.

STUDY DESIGN: Prospective randomized study to compare the efficacy of facet joint injection with lidocaine and facet joint injection with saline in two groups of patients with low back pain, with and without clinical criteria that were determined in a previous study to implicate the facet joint as the primary source of the pain. OBJECTIVES: To assess the efficacy of single facet joint anesthesia versus placebo (saline injections) and to determine clinical criteria that are predictive of significant relief of LBP after injection. SUMMARY OF BACKGROUND DATA: There is no syndrome that discriminates between lower back pain caused by facet joint and that caused by other structures. Single or double facet joint anesthesia, and single photon emission computed tomography are expensive and time-consuming procedures for selecting patients in controlled clinical trials with large populations. METHODS: Results of a previous study showed that seven clinical characteristics were more frequent in patients who responded to facet joint anesthesia than in those who did not. In the current study, a group of 43 patients with lower back pain who met at least five criteria were compared with 37 patients who met fewer criteria. Patients randomly received injection of either lidocaine or saline into the lower facet joints. The result was considered positive if more than 75% pain relief was determined by visual analog scale. The patient, the radiologist, and the investigator were blinded. An analysis of variance was used to seek an interaction between clinical group effect and injection effect, and logistic regression analysis to select the best set of variables that would be predictive of minimum pain relief of 75% after the injection. RESULTS: There was a significant interaction between clinical group and injection effect (P = 0.003). In patients with back pain, lidocaine provided greater lower-back pain relief than saline (P = 0.01). Lidocaine also-provided greater pain relief in the back pain group than in the nonpain group (P = 0.02). The presence of five among seven variables (age greater than 65 years and pain that was not exacerbated by coughing, not worsened by hyperextension, not worsened by forward flexion, not worsened when rising from flexion, not worsened by extension-rotation, and well-relieved by recumbency), always including the last item, distinguished 92% of patients responding to lidocaine injection and 80% of those not responding in the lidocaine group. CONCLUSIONS: A set of five clinical characteristics can be used in randomized studies to select lower back pain that will be well relieved by facet joint anesthesia. These characteristics should not, however, be considered as definite diagnostic criteria of lower back pain originating from facet joints.

Adult↗