Biomedical subjects

Serge Poiraudeau

Publications and source records attributed to Serge Poiraudeau.

At least 19 recordsLinked to original sources

PubMed2007

Relation of inflammatory modic changes to intradiscal steroid injection outcome in chronic low back pain.

The purpose of this study was to analyze the association between the severity of inflammatory endplate changes (Modic) on MRI and the clinical response to intradiscal injection of corticosteroids (IDIC) in chronic low back pain (LBP). A total of 74 patients with LBP and inflammatory Modic changes who showed no response to 3-month conservative treatment received lumbar IDIC. Two spine specialists and a radiologist assessed independently the endplate marrow changes of the injected discs. We classified patients with a pure edema endplate changes on MRI as Modic type I (n = 37); those with a mixture of Modic type I and type II changes but predominantly edema changes as Modic I-2 (n = 25) and those with predominantly fatty changes as Modic II-1 (n = 12). The primary outcome was the change in LBP intensity between baseline and 1 month after IDIC, as measured on a visual analog scale (range 0-100 mm). At 1 month, reduction in pain score was significantly higher in the Modic I and Modic I-2 groups than in the Modic II-1 group (30.2 +/- 26.6 and 29.4 +/- 21.5 vs 5.3 +/- 25.5; P = 0.009 and P = 0.017, respectively). At 3 and 6 months, IDIC tended to be more effective in the Modic I and Modic I-2 groups but not significantly. No complications such as infection or hematoma were reported. IDIC could be a short-term efficient treatment for patients with chronic LBP and predominantly inflammatory endplate changes when conservative treatments have failed.

Adrenal Cortex Hormones↗

PubMed2006

Intradiscal corticosteroid injections in spondylotic cervical radiculopathy.

The purpose of this study was to evaluate treatment outcomes with intradiscal injection of corticosteroids (IDIC) in cervical spondylotic radiculopathy. Twenty consecutive patients were treated with intradiscal injection of 25 mg of acetate of prednisolone under fluoroscopic control. All patients had previously received a nonsurgical treatment for at least 3 months without success. Outcomes were assessed 1, 3 and 6 months after IDIC. Radicular pain reduction as scored on a visual analogue scale (VAS 100-mm length) was statistically significant at 1 month (19.0+/-28.0 mm; p=0.008), 3 months (25.2+/-27.5 mm; p=0.002), and 6 months (24.6+/-28.4 mm; p=0.001). In all, 40% of treated patients described at least 50% pain improvement 6 months after treatment. Four patients had complete relief of radicular pain. In conclusion, IDIC should be an alternative in the nonsurgical management of cervical spondylotic radiculopathy.

Adult↗

PubMed2006

General practitioners' fear-avoidance beliefs influence their management of patients with low back pain.

The objectives of this cross-sectional study conducted in primary care practice in France were to describe general practitioners' (GPs) fear-avoidance beliefs about low back pain (LBP), investigate the impact of these beliefs on their following guidelines for bed rest, physical activities, and sick leave, and uncover factors associated with GPs' fear-avoidance beliefs. A total of 864 GPs completed a 5-part self-administered questionnaire. Parts 1, 2, and 3 concerned demographic, professional data, and personal history of back pain, respectively. Part 4 dealt with GPs' education about LBP and practice for LBP. Part 5 assessed GPs' fear-avoidance beliefs on the Fear-Avoidance Beliefs Questionnaire (FABQ). GPs' mean age was 48.2+/-7.0 years, 80% were male, 88% had been practicing for more than 10 years, and 52% reported a previous personal episode of acute LBP. Forty-six percent had participated in an educational session on LBP during the last 3 years. Mean scores for the FABQ Phys and Work were 9.6+/-4.8 and 17.5+/-6.7, respectively. Sixteen percent of participants had high rating on the FABQ Phys (FABQ Phys score>14). FABQ Phys score was associated with recommendation of bed rest or rest during sick leave (p<0.0001) for acute LBP and less advice to maintain maximum bearable physical activities (p<0.001) for chronic LBP. FABQ Work score was associated with prescribing sick leave during painful periods (p<0.005) for acute LBP and less advice to maintain maximum bearable physical activities (p<0.001) for chronic LBP. GPs' fear-avoidance beliefs about LBP negatively influence their following guidelines concerning physical and occupational activities for patients with LBP.

Adult↗

PubMed2006

Nonpharmacological treatments in early rheumatoid arthritis: clinical practice guidelines based on published evidence and expert opinion.

OBJECTIVE: To develop clinical practice guidelines for the use of nonpharmacological treatments in patients with early rheumatoid arthritis (RA), using the evidence-based approach and expert opinion. METHODS: A scientific committee used a Delphi prioritization procedure to select five questions. Evidence providing answers to the five questions was sought in the literature and presented to a panel of rheumatologists. The panel developed five detailed recommendations, filling gaps in evidence with their expert opinion. The strength of each recommendation was determined. RESULTS: Of the 565 publications retrieved by the literature review, 198 were included in the analysis. The five recommendations on nonpharmacological treatments for early RA were validated by a final vote among all participants. The recommendations are as follows: (1) physicians may decide to provide joint protection education to patients with potentially severe early RA, with the knowledge that structured joint protection programs have not been found effective; (2) physical exercise and sports can be recommended to patients with early RA; muscle strength exercises are advisable; (3) in patients with early RA, metatarsal pain and/or foot alignment abnormalities should be looked for regularly, and appropriate insoles should be prescribed if needed; (4) dietary measures and nutritional supplements are not indicated as part of the treatment of early RA; (5) elimination diets, particularly those with low intakes of dairy products, should be discouraged in patients with early RA. CONCLUSION: These recommendations should help to improve practice uniformity and, ultimately, to improve the management of RA.

Arthritis, Rheumatoid↗

PubMed2006

[Therapeutic management of systemic sclerosis].

UNLABELLED: Improved understanding of the pathophysiology of systemic sclerosis (SSc) opens new therapeutic avenues in its treatment. The efficacy of disease-modifying agents remains limited however, and none has yet demonstrated its ability to improve survival in a prospective randomized trial. RESULTS: of traditional antifibrotic agents such as colchicine and D-penicillamine are disappointing. Cyclophosphamide (CYC) seems to be beneficial in interstitial lung disease associated with SSc. Organ-specific therapies may produce dramatic benefits. Examples include angiotensin-converting enzyme inhibitors for renal failure and epoprostenol for primary pulmonary hypertension. Several new therapeutic approaches are currently under evaluation, including high-dose CYC followed by peripheral stem cell transplantation, vasodilators, and antiinflammatory and antifibrotic agents. Physical therapy and rehabilitation may help to treat disability and loss of function in SSc patients.

Acute Kidney Injury↗

PubMed2005

A checklist to evaluate a report of a nonpharmacological trial (CLEAR NPT) was developed using consensus.

BACKGROUND AND OBJECTIVE: To develop a checklist of items measuring the quality of reports of randomized clinical trials (RCTs) assessing nonpharmacological treatments (NPTs). STUDY DESIGN AND SETTING: The Delphi consensus method was used to select and reduce the number of items in the checklist. A total of 154 individuals were invited to participate: epidemiologists and statisticians involved in the field of methodology of RCTs (n = 55), members of the Cochrane Collaboration (n = 41), and clinicians involved in planning NPT clinical trials (n = 58). Participants ranked on a 10-point Likert scale whether an item should be included in the checklist. RESULTS: Fifty-five experts (36%) participated in the survey. They were experienced in systematic reviews (68% were involved in the Cochrane Collaboration) and in planning RCTs (76%). Three rounds of the Delphi method were conducted to achieve consensus. The final checklist contains 10 items and 5 subitems, with items related to the standardization of the intervention, care provider influence, and additional measures to minimize the potential bias from lack of blinding of participants, care providers, and outcome assessors. CONCLUSIONS: This tool can be used to critically appraise the medical literature, design NPT studies, and assess the quality of trial reports included in systematic reviews.

Consensus↗

PubMed2005

Magnetic resonance imaging of shoulders with idiopathic adhesive capsulitis: reliability of measures.

The magnetic resonance imaging (MRI) findings in idiopathic adhesive capsulitis (AC) were compared with those of contralateral healthy shoulders and the reliability of measures assessed. Twenty-six consecutive patients (26 AC and 14 healthy shoulders) were prospectively assessed. The main measurements were thickness of the joint capsule and synovial membrane in the axillary recess and rotator interval in T1-weighted spin-echo sequence enhanced with intravenous (IV) gadolinium chelate (Gd-chelate). Reliability was studied by use of the intraclass correlation coefficient (ICC). The mean thickness of the axillary recess on the coronal plane was 9.0+/-2.2 mm in AC shoulders and 0.4+/-0.7 mm in healthy shoulders. The mean thickness of the rotator interval on the sagittal plane was 8.4+/-2.8 in AC shoulders and 0.6+/-0.8 mm in healthy shoulders. Interobserver reliability was good for the axillary recess, with ICC values of 0.84 for the coronal plane, and good for the rotator interval, with ICC values of 0.80 for the sagittal plane. MRI with IV Gd-chelate injection can show, with acceptable reliability, signal and thickness abnormalities of the shoulder joint capsule and synovial membrane in AC.

Adult↗

PubMed2005

[Functional disability indexes: translation difficulties and cross cultural adaptation problems].

OBJECTIVES: To summarize the difficulties involved in translating tests in Arabic and to describe the translation methods and to apply those to functional indexes. METHOD: Four functional indexes were translated and then subjected to the following test validation methods: back translation, pre-test, and review by an expert committee. RESULTS: Translation problems were underlined. These include in particular the different types of equivalence between the source language and the target language (semantics, idioms, conceptual... equivalences). Problems related to comprehensive literal words were the most observed. CONCLUSION: The current method combining translation with back translation is not sufficient and must be used with, a pre-test and a review committee.

Arabs↗

PubMed2004

Development and validation of an Arabic rheumatoid hand disability scale.

PURPOSE: To develop a rheumatoid hand disability scale in the Arabic language adapted for local sociocultural specificities and to test its psychometric properties. METHODS: The choice of hand activities was based on several published indices. The selected items were translated by the forward and backward translation procedures, several modifications were made, and after some questions were added, a provisional scale was obtained. In- and outpatients with rheumatoid arthritis (RA) according to the ACR criteria were chosen to answer the provisional scale and to assess the final scale. Impairment outcome measures (pain as measured on a visual analogue scale, morning stiffness, hand swelling, tenderness), and assessment of disability (on Lee's and Revel's functional indices) were also recorded. The intraclass correlation coefficient and the Bland and Altman methods were used to assess reliability. Construct (convergent and divergent) validity was investigated with use of Spearman's rank correlation, and a factor analysis was performed. RESULTS: The provisional scale had 21 questions. The adaptation process left 10 questions about hand activity, with four levels of answers. Eighty patients with RA were recruited for the validation of the final scale. The intra- and interrater reliabilities of the scale were 0.96 and 0.94, respectively. Analysis by the Bland and Altman method showed no systematic trend. The scale had good construct validity, with expected convergence with Lee's functional index (r(s)=0.79) and Revel's functional index (r(s)=0.81) and divergence with age (r(s)=0.05), morning stiffness (r(s)=0.40), pain (r(s)=0.32), and tenderness (r(s)= -0.48). The factorial structure of the scale was satisfying, with two factors explaining 73% of the variance. CONCLUSION: We developed an Arabic index that assesses hand disability due to RA and suits Tunisian people. Further studies are needed to confirm the validity of the scale in other Arabic countries.

Adolescent↗

PubMed2004

Validation of the French version of the fear avoidance belief questionnaire.

STUDY DESIGN: Observational prospective study. OBJECTIVE: To assess the reliability, validity, and responsiveness of the French version of the Fear Avoidance Belief Questionnaire. SUMMARY OF BACKGROUND DATA: Fear, avoidance attitudes, and belief play pivotal roles in disability perceived by patients with chronic low back pain. The Fear Avoidance Belief Questionnaire is a two-part questionnaire assessing fear, avoidance, and beliefs about professional activity and physical activity. METHODS: The Fear Avoidance Belief Questionnaire was translated by use of the forward and backward translation procedure. Test-retest reliability was assessed in 31 patients (Group 1) with the intraclass correlation coefficient and the Bland and Altman method. Construct validity was assessed in two groups of patients (Group 2, n = 147; Group 3, n = 70) with the Spearman rank correlation coefficient and factor analysis. Responsiveness was assessed in Group 3, after they underwent a functional restoration program, by the effect size and the standardized response mean. RESULTS: Test-retest reliability was good, with an intra-class correlation coefficient value of 0.88 and 0.72 for fear, avoidance, and beliefs about professional activity and physical activity, respectively. Use of the Bland and Altman method produced a homogeneous distribution of the differences, with no systematic trend observed. The expected divergent validity was observed in Groups 2 and 3. Factor analysis extracted four factors in Group 2 and the two original factors of the English Fear Avoidance Belief Questionnaire in Group 3. The lowest effect size and standardized response mean values (0.30 and 0.31, respectively) were observed with the fear, avoidance, and beliefs about professional activity. CONCLUSIONS: The psychometric properties (test-retest reliability, construct validity, and responsiveness) of the French version of the Fear Avoidance Belief Questionnaire are acceptable, and fear, avoidance, and belief can now be assessed in French-speaking patients with low back pain.

Adaptation, Psychological↗

PubMed2004

[Rehabilitation on effort of low back pain. Functional restoration programs].

Mediocre functional prognosis In industrialised countries, chronic low back pain is the most common cause of disability and work stoppage. Conventional treatments have not reduced the impact of chronic low back pain. Hence new solutions have been searched for. FUNCTIONAL RESTORATION PROGRAMS: These programs consist in heavy and expensive multidisciplinary treatment schedules, lasting from 3 to 6 weeks. The key concepts of these programs are acceptance of pain, treatment of the problem by the patients themselves and a progression contract. POSITIVE RESULTS: Controlled studies published on the percentage of patients returning to work are positive. Maintenance of a job-attached status to the pre-injury employer is often best accomplished by the provision of suitable modified duties. Finally, results of functional restoration programs in term of return-to-work rate probably strongly depend on the social security system of the country in which such programs have been developed.

Chronic Disease↗

PubMed2004

The ability to change of three questionnaires for neck pain.

OBJECTIVE: To assess the sensitivity to change of three algofunctional scales for neck pain. METHODS: Observational, prospective study. Patients with neck disorders were included. Pain and patients' perceived handicap assessed on visual analogue scales (VAS Pain, VAS Handicap), and functional disability measures (Neck Disability Index, Neck Pain and Disability Scale, Northwick Park Neck Pain Questionnaire) were recorded twice, at baseline and at an 11-month follow-up assessment. Sensitivity to change was assessed using the effect size (ES) and the standardised response mean (SRM), and the non-parametric Spearman's rank correlation coefficient (r) was used to assess the correlation between quantitative variable changes and patients' overall opinion. Analysis of variance (ANOVA) followed by a Tukey-test was performed to determine if the scales distinguished improved, stable, and deteriorated patients. RESULTS: Seventy-one patients (43 women, mean age 49 years) were included and evaluated twice at an interval of 11 +/- 2 months. The three scales showed good sensitivity to change. The ANOVA showed a group effect, and individual changes in the scales scores were statistically different in two-by-two comparisons (improved, stable or deteriorated patients). Changes in NPDS scores had the highest correlation with patient's overall assessment (r = 0.592). CONCLUSION: The three scales can detect changes in patients with neck disorders. Changes in NPDS score had the best correlation with patients' overall opinion concerning their neck disorder and this questionnaire should be given preference in clinical trials.

Adolescent↗

PubMed2004

Disability induced by hand osteoarthritis: are patients with more symptoms at digits 2-5 interphalangeal joints different from those with more symptoms at the base of the thumb?

BACKGROUND: The contribution of osteoarthritis (OA) at the base of the thumb (BT) and digits 2-5 interphalangeal joints (IP) to disability in the hand has never been assessed. OBJECTIVES: To evaluate and compare disability in patients with clinical hand OA and more severe symptoms at BT or IP. DESIGN: Observational, prospective, correlational. SETTING: Rheumatology and rehabilitation departments in two tertiary care teaching hospitals. PARTICIPANTS: One hundred and sixteen patients (107 women, mean age 62+/-7 years) fulfilling the American College of Rheumatology criteria for OA in the hand, with more symptomatic BT (67 patients) or IP (49 patients). MAIN OUTCOME MEASURE: Disability assessment with Cochin hand functional scale (CHFS) was the primary outcome. Assessment of impairment by the visual analog scale of pain (VAS pain), Ritchie articular index (RAI), modified Kapandji index (mKI), Kallman radiological classification and handicap assessment with visual analog scale (VASHd) was the secondary outcome. Group comparisons were assessed by use of Student's t-test for quantitative variables and Chi-square test for categorical variables. Results of the CHFS analysis were assessed by factorial analysis followed by Varimax rotation. Correlation between scores of disability, impairment, and handicap measures were calculated with use of Spearman rank correlation coefficient. RESULTS: Demographic data, disease duration, and level of global pain were similar between the BT and IP groups. The BT and IP groups did not differ significantly according to disability and handicap level (P=0.42 and P=0.94 for CHFS total score and VASHd, respectively). Factor analysis of the CHFS revealed similar results for the two groups of patients, especially for the first extracted factor. Disability scores correlated best with global hand pain (r=0.65) in the BT group and with RAI scores (r=0.71) in the IP group. CONCLUSIONS: Disability and perceived handicap levels are comparable in clinical hand OA patients with more symptomatic BT or IP. These two groups should not be considered different during trials assessing treatments for hand OA when the primary outcome measure assesses disability.

Aged↗

PubMed2004

Translation, adaptation and validation of the Western Ontario and McMaster Universities osteoarthritis index (WOMAC) for an Arab population: the Sfax modified WOMAC.

OBJECTIVE: To translate into Arabic and validate the Western Ontario and McMaster Universities (WOMAC) index. METHOD: Arabic translation was obtained with use of the forward and backward translation method. Adaptations were made after a pilot study. Patients with symptomatic knee OA fulfilling the revised criteria of the American College of Rheumatology were included. Impairment outcome measures (pain as measured on a visual analog scale, the maximum distance walked, Kellgren's radiological score), Lequesne index score and Beck depression scale score were recorded. Each item was analyzed. Test-retest reliability was assessed with use of the intra-class correlation coefficient (ICC) and the Bland and Altman method. Construct validity was investigated with use of Spearman's rank correlation coefficient, and a factor analysis was performed. RESULTS: One hundred and three patients were included in the study. Eight questions of the WOMAC physical function subscale (PF) had insufficient psychometric properties and were excluded. Although test-retest reliability of the questionnaire was good (0.84, 0.84, and 0.92 for pain, stiffness, and modified PF subscales respectively), construct validity could not be demonstrated. Factor analysis of the modified form of the WOMAC extracted four factors, which differed from the a priori triple stratification. However, factor analysis of the modified PF subscales extracted two factors, which accounted for 68.4% of the total variance and could be clinically characterized (disability during activities requiring knee flexion within the first 90 degrees and activities requiring knee flexion over more than 90 degrees ). CONCLUSION: We translated and adapted the WOMAC index into Arabic to suit Tunisian people. The translated questionnaire is reliable but not valid in its original form. We propose the use of a modified version of PF subscale of the WOMAC, although the psychometric properties of this instrument must be examined in a larger population.

Aged↗

PubMed2004

Assessment of the test-retest reliability and construct validity of a modified WOMAC index in knee osteoarthritis.

OBJECTIVE: To assess the test-retest reliability and the construct validity of a modified version of the French-Canadian version of the WOMAC index. METHODS: Open prospective study conducted in departments of Rheumatology, Rehabilitation and Orthopedic surgery of a tertiary care teaching hospital. Eighty-eight patients with symptomatic knee osteoarthritis (OA) fulfilling the revised criteria of the American College of Rheumatology were included. The French-Canadian version of the WOMAC index was completed twice at a 3-h interval. Impairment outcome measures, patients' perceived discomfort in walking and handicap were recorded. An item-by-item analysis was performed. Test-retest reliability was assessed using the intra-class correlation coefficient (ICC) and the Bland and Altman method. Construct validity was investigated using the Spearman rank correlation coefficient and a factor analysis was performed. RESULTS: Eight questions assessing function (section C) and the two questions assessing stiffness (section B) had insufficient psychometric properties and were excluded. Although test-retest reliability of the questionnaire was fair to good (0.82, 0.85, for the WOMAC section A, and modified section C, respectively), construct validity could not be demonstrated. Factor analysis of the modified form of the WOMAC extracted four factors, which differed from the a priori stratification. However, factor analysis of the modified section C extracted two factors explaining 68.4% of the variance, which could be clinically characterized. CONCLUSION: Despite its good test-retest reliability, the modified WOMAC index is not valid for assessing pain and disability induced by knee OA in a French population. Section A and modified section C could be used separately to assess, respectively, pain and function.

Adult↗

PubMed2004

Effects of pro- and anti-inflammatory cytokines and nitric oxide donors on hyaluronic acid synthesis by synovial cells from patients with rheumatoid arthritis.

The aim of the present study was to investigate the effects of (i) the pro-inflammatory cytokines IL (interleukin)-1beta, TNF-alpha (tumour necrosis factor-alpha), IFN-gamma (interferon-gamma) and anti-inflammatory cytokines IL-4 and IL-13, and (ii) NO (nitric oxide) donors on HA (hyaluronic acid) production by synovial cells from patients with rheumatoid arthritis. Synovial cells obtained from five patients with rheumatoid arthritis were incubated for 24 h without or with IL-1beta, TNF-alpha, IFN-gamma, or with this mixture for 24 h plus IL-4 or IL-13 for the last 6 h. The same cells were also incubated for 3-24 h without or with SNP (sodium nitroprusside) or SNAP (S-nitroso-N-acetyl-DL-penicillamine). HA secretion was determined by an immunoenzymic assay based on HA-specific binding by proteoglycan isolated from bovine cartilage. IL-1beta, TNF-alpha and IFN-gamma alone or in combination stimulated HA synthesis, whereas IL-4 and IL-13 dose-dependently inhibited HA production induced by Th1 cytokines. HA production was significantly increased by the presence of 1 mM SNP after 6 and 12 h (maximal effect). HA production was significantly increased by the presence of 0.01 and 0.1 mM SNAP after 12 h of incubation, and cells treated with 1 mM SNAP showed a maximal HA production after 24 h of incubation. In conclusion, the present study provides data concerning the regulatory role of pro- and anti-inflammatory cytokines and NO donors on HA metabolism in rheumatoid synovial cells and may help in understanding the pathophysiology of rheumatoid arthritis.

Aged↗

PubMed2004

Social and personal consequences of disability in adults with hip and knee arthroplasty. A French national community based survey.

OBJECTIVE: To describe and compare participation restrictions and environmental factors of persons with and without hip or knee arthroplasty in a national community based survey: the Handicap, Disability, Dependence Survey. METHODS: During the 1999 French Census, a screening questionnaire was proposed to 417,500 persons, for which the response rate was 86%. A stratified random sample with an overrepresentation of disabled persons was performed to constitute the selected population. A computer assisted interview was proposed to 21,760 persons, with a 78% response rate. Chronic conditions, impairment, disability, participation restrictions, and the description of environmental factors were ascertained from the subjects' reports. RESULTS: The hip and knee arthroplasty group was estimated at 691,000 persons in the French population. Although reporting a higher level of disability, this population did not report more participation restrictions than the general population in terms of their economic situation, housing, social relationships, and holidays. Moreover, when comparing environmental factors, this population reported better housing accessibility, more assistive devices (OR 5.2, 95% CI 3.7-7.2), specific fittings (OR 2.9, 95% CI 2.0-4.2), and helpers (OR 1.8, 95% CI 1.3-2.5). These environmental factors may have compensated for the higher level of disability. Nevertheless, individuals with hip and knee arthroplasty reported more disadvantages when moving within their environment (OR 2.1, 95% CI 1.5-2.9). CONCLUSION: This study provides a detailed description based on a national random sample of participation restrictions and environmental factors of adults with hip and knee arthroplasty.

Activities of Daily Living↗

PubMed2003

Cyclic tensile stretch modulates proteoglycan production by intervertebral disc annulus fibrosus cells through production of nitrite oxide.

Degeneration of the intervertebral disc is the main pathophysiological process implicated in low back pain and is a prerequisite to disc herniation. Clinically, mechanical forces are important modulators of the degeneration, but the underlying molecular mechanism is not known and needs investigation to identify the biological target. The aim of this work was to study, at the molecular level, the effects of cyclic tensile stretch (CTS) on the production of proteoglycan by intervertebral disc annulus fibrosus cells since proteoglycans seem to be implicated in the dynamic process of intervertebral disc degeneration. Such cells of rabbit were cultured at high density on plates with a flexible bottom. CTS was applied with use of a pressure-operated instrument to deform the plates. With CTS at 1% elongation (1 Hz frequency), the level of (35)S-labeled neosynthesized proteoglycans that accumulated in the cellular pool or were secreted in the culture medium did not change, but at 5% elongation, the level was significantly reduced after 8 h of stimulation (30 and 21%, respectively) and further reduced at 24 h (43 and 41%, respectively). Introducing the protein synthesis inhibitor cycloheximide had no effect on this result. Neither aggrecan and biglycan expression nor proteoglycan physical properties were modified. The level of nitrite oxide production significantly increased by 3.5 times after 8 h of 5% elongation. Introducing the nitric oxide synthase (NOS) inhibitors N(G)-methyl-l-arginine or N-omega nitro-l-arginine diminished the effects of CTS on the production of nitrite oxide and proteoglycans. By contrast, introducing N-iminoethyl-l-lysine (a more specific inhibitor of inductible NOS [iNOS]) had little or no effect. Taken together, these results suggest that cNOS activation seems to be more implicated in the 5% CTS modulation of proteoglycan production than iNOS activation. These results suggest that CTS can help regulate the intervertebral disc matrix by decreasing proteoglycan production through a post-translational regulation involving nitrite oxide. This result could be of interest in the development of local therapeutic strategies aimed at controlling intervertebral disc degeneration.

Animals↗