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Y Henrotin

Publications and source records attributed to Y Henrotin.

At least 19 recordsLinked to original sources
PubMed2006

A type II-collagen derived peptide and its nitrated form as new markers of inflammation and cartilage degradation in equine osteochondral lesions.

Markers of cartilage breakdown enable studying the degradation of cartilage matrix in equine joint pathologies. This study was designed to determine the levels of Coll2-1, a peptide of the triple helix of type II collagen, and Coll2-1NO(2), its nitrated form in the plasma of healthy horses (controls; n=37) and horses suffering from osteochondrosis (n=34). Clinical and arthroscopic scores were attributed reflecting the severity of lesions and were related to the plasma levels of Coll2-1 and Coll2-1NO(2). The median of Coll2-1 was significantly higher in the control group, whereas the mean of Coll2-1NO(2) showed significant elevation in the pathological group. However, the measurement means of scoring classes did not vary significantly. The markers were able to differentiate the group of horses suffering from osteochondrosis from the group of healthy horses. The elevation of Coll2-1NO(2) in the pathological group indicates an inflammation, mediated through reactive oxygen species and/or increased myeloperoxidase activity.

Animals↗
PubMed2005

Comparative effects of IL-1beta and hydrogen peroxide (H2O2) on catabolic and anabolic gene expression in juvenile bovine chondrocytes.

OBJECTIVE: To compare the effects of hydrogen peroxide (H(2)O(2)) to those of interleukin-1beta (IL-1beta) on gene expression in juvenile bovine articular chondrocytes (BAC). The study analyses the activation of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1) transcription factors, and the mRNA steady-state levels of the type II collagen, aggrecan core protein matrix, metalloproteinases (MMP-1, -3), and transforming growth factor-beta1 (TGF-beta1) genes. METHODS: Confluent BAC cultures were treated for 3 and 24h with IL-1beta and/or different concentrations of H(2)O(2) (Protocol 1). Following initial treatment, a part of the cells was further subjected to another 24h with medium, in the presence of IL-1beta, to determine the effect of the cytokine on H(2)O(2) pre-treated cells (Protocol 2). Total RNA and nuclear protein extractions were performed to study mRNA steady-state levels (real-time polymerase chain reaction) and AP-1/NF-kappaB DNA binding (Electrophoretic Mobility Shift Assays), respectively. RESULTS: IL-1beta enhanced both AP-1 and NF-kappaB binding, whereas H(2)O(2) only activated AP-1. H(2)O(2) pre-treatment decreased the IL-1beta activation of NF-kappaB. Both H(2)O(2) and IL-1beta down-regulated type II collagen and aggrecan expression and increased that of MMP-1 and -3. When cells were pre-treated with H(2)O(2), followed by IL-1beta, the effects were the same as those observed with H(2)O(2) alone. However, although H(2)O(2) and IL-1beta were capable of increasing TGF-beta1 expression separately, subsequent incubation with both factors led to a partial or total abolition of TGF-beta1 up-regulation. CONCLUSION: The different regulation of NF-kappaB and AP-1 by H(2)O(2) and IL-1beta underlines the distinct roles played by the two transcription factors in the regulation of gene expression. H(2)O(2) and IL-1beta exert similar effects on matrix, MMPs and TGF-beta1 gene expression. However, the association of H(2)O(2) and IL-1beta does not cause synergic effect, and rather leads, in some cases, to an opposite effect. These data provide further insights into the respective roles of reactive oxygen species and cytokine in the pathophysiology of joint diseases.

Aggrecans↗
PubMed2005

How to prevent low back pain.

This chapter summarizes the European Guidelines for Prevention in Low Back Pain, which consider the evidence in respect of the general population, workers and children. There is limited scope for preventing the incidence (first-time onset) of back pain and, overall, there is limited robust evidence for numerous aspects of prevention in back pain. Nevertheless, there is evidence suggesting that prevention of various consequences of back pain is feasible. However, for those interventions where there is acceptable evidence, the effect sizes are rather modest. The most promising approaches seem to involve physical activity/exercise and appropriate (biopsychosocial) education, at least for adults. Owing to its multidimensional nature, no single intervention is likely to be effective at preventing the overall problem of back pain, although there is likely to be benefit from getting all the players onside. However, innovative studies are required to better understand the mechanisms and delivery of prevention in low back pain.

Exercise Therapy↗
PubMed2005

Influence of oxygen tension on nitric oxide and prostaglandin E2 synthesis by bovine chondrocytes.

OBJECTIVES: To determine the in vitro effects of oxygen tension on interleukin (IL)-1beta induced nitric oxide (*NO) and prostaglandin E(2) (PGE(2)) production by bovine chondrocytes. DESIGN: Enzymatically isolated bovine chondrocytes were cultured for different periods in suspension in 21 (atmospheric), 5 or 1% (low) oxygen tension and in the absence or in the presence of increased amounts (0.01 to 1nM) of IL-1beta. Nitrite and nitrate concentrations in the culture supernatants were determined by a spectrophotometric method based upon the Griess reaction. PGE(2) production was quantified by a specific radioimmunoassay (RIA). Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) mRNA steady state levels were also quantified by real-time polymerase chain reaction (PCR). RESULTS: In the absence of IL-1beta, ()NO production remained stable whatever the oxygen tension used. IL-1beta dose-dependently increased *NO production in both atmospheric and low oxygen conditions but the effect was more pronounced in low (1 and 5%) than in atmospheric (21%) oxygen tension (P<0.001). Under low and atmospheric oxygen tension, iNOS gene expression was increased by IL-1beta, but to a lesser extent in 21% than in 1 or 5% oxygen (P<0.01). In the basal condition, bovine chondrocytes spontaneously produced PGE(2) whatever the oxygen tension used. At 21% oxygen, IL-1beta dose-dependently increased PGE(2) production while no significant effect was observed at 1 or 5% oxygen. COX-2 gene expression was significantly upregulated by IL-1beta in both low and atmospheric oxygen tension. No significant difference between oxygen tension conditions was observed. CONCLUSIONS: This study demonstrates that a hypoxic environment fully blocks COX-2 activity but favours iNOS gene expression in chondrocytes culture. These findings indicate that O(2) tension modulates cellular behaviour in culture and supports the concept of chondrocyte culture in low oxygen tension to reproduce in vitro the life conditions of chondrocytes.

Animals↗
PubMed2005

Oxygen and reactive oxygen species in cartilage degradation: friends or foes?

OBJECTIVES: This review is focused on the influence of oxygen and derived reactive species on chondrocytes aging, metabolic function and chondrogenic phenotype. METHODS: A systematic computer-aided search of the Medline database. RESULTS: Articular cartilage is an avascular tissue, and consequently oxygen supply is reduced. Although the basal metabolic functions of the cells are well adapted to hypoxia, the chondrocyte phenotype seems to be oxygen sensitive. In vitro, hypoxia promotes the expression of the chondrogenic phenotype and cartilage-specific matrix formation, indicating that oxygen tension is probably a key parameter in chondrocyte culture, and particularly in the context of tissue engineering and stem cells transplantation. Besides the influence of oxygen itself, reactive oxygen species (ROS) play a crucial role in the regulation of a number of basic chondrocyte activities such as cell activation, proliferation and matrix remodeling. However, when ROS production exceeds the antioxidant capacities of the cell, an "oxidative stress" occurs leading to structural and functional cartilage damages like cell death and matrix degradation. CONCLUSIONS: This paper is an overview of the in vitro and in vivo studies published on the influence of oxygen and derived reactive species on chondrocyte aging, metabolic function, and the chondrogenic phenotype. It shows, that oxygen and ROS play a crucial role in the control of cartilage homeostasis and that at this time, the exact role of "oxidative stress" in cartilage degradation still remains questionable.

Aging↗
PubMed2004

Effect of hypoxia and reoxygenation on gene expression and response to interleukin-1 in cultured articular chondrocytes.

OBJECTIVE: To determine the effects of hypoxia and reoxygenation on the metabolism of chondrocytes and their response to interleukin-1beta (IL-1beta). The study included activation of hypoxia-inducible factor 1 (HIF-1), NF-kappaB, and activator protein 1 (AP-1) transcription factors, expression of matrix components and metalloproteases and transforming growth factor beta (TGFbeta) and TGFbeta receptors, and production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)). METHODS: Bovine articular chondrocytes (BACs) were cultured to confluency in either 5% O(2) (hypoxia) or 21% O(2) (normoxia) in media supplemented with 10% fetal calf serum (FCS). BACs were preincubated for 18 hours in media with 1% FCS only and then incubated for 24 hours in the presence of IL-1beta. For reoxygenation experiments, cells were treated in the same way in 5% O(2), except that cultures were transferred to normal atmospheric conditions and used after 4 hours for RNA extraction or after 30 minutes for cytoplasmic or nuclear protein extraction. RESULTS: In hypoxic and reoxygenated chondrocytes, we observed strong DNA binding of HIF-1. IL-1beta-induced DNA binding of NF-kappaB and AP-1 was significantly higher in hypoxic and reoxygenated cultures than in normoxia. Greater activation of the MAPKs was also observed with IL-1beta treatment in hypoxia compared with normoxia. Steady-state levels of type II collagen and aggrecan core protein messenger RNA (mRNA) were decreased by IL-1beta in all instances. Matrix metalloprotease 1 (MMP-1) and MMP-3 mRNA were increased by IL-1beta in normoxia and hypoxia, whereas only MMP-3 mRNA was enhanced in reoxygenated cultures. The MMP-2 mRNA level was not significantly affected by IL-1beta in normoxia or hypoxia, whereas it was enhanced in reoxygenated cultures. MMP-9 mRNA was dramatically decreased by IL-1beta only in low oxygen tension. Tissue inhibitor of metalloproteinases 1 (TIMP-1) message was significantly enhanced by the cytokine in most instances, whereas TIMP-2 message was markedly decreased by IL-1beta in reoxygenated cultures. Stimulation of TGFbeta1 expression by IL-1beta was observed only in normal atmospheric conditions. One of the more striking findings of the study was the greater stimulating effect of IL-1beta on NO production observed in hypoxia, which was much higher than in normoxia, whereas the reverse was observed for IL-1beta-induced PGE(2) production. CONCLUSION: Oxygen level and reoxygenation stress significantly modulate gene expression and the response of articular chondrocytes to cytokines such as IL-1beta. In hypoxic conditions, which mimic the in vivo condition of cartilage, the effects of IL-1beta on both synthesis and degradative processes are significantly different from those in normoxia, conditions that are unlikely encountered by chondrocytes in a normal state. In low oxygen tension, high IL-1beta-induced NO production is associated with a significant decrease in PGE(2) synthesis. These data should influence our concept of the role of oxygen in the pathophysiology of joint disease and may help define the best conditions in which to develop bioartificial cartilage.

Aggrecans↗
PubMed2004

Reduction in PINP, a marker of bone metabolism, with raloxifene treatment and its relationship with vertebral fracture risk.

In the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, 7705 postmenopausal women with osteoporosis, defined by low bone mineral density and/or prevalent vertebral fractures (VF), were randomized to placebo or raloxifene (60 or 120 mg/day). All women received daily calcium (500 mg) and vitamin D (400-600 IU) supplements. Our previous analyses found that changes in BMD and biochemical markers of bone turnover are poorly predictive of the reduction in VF risk observed with raloxifene. This present study evaluated the effects of raloxifene on type I procollagen N-terminal propeptide (PINP), a new marker of bone turnover. Logistic regression analysis models evaluated the relationships between the changes at 1 year in PINP, serum osteocalcin (OC), bone-specific alkaline phosphatase (BSAP), and urinary excretion of type I collagen C-telopeptide fragments normalized to creatinine (CTx/Cr), and the risk of new VF at 3 years for placebo and pooled raloxifene. A subset of 967 women (mean age = 68 years) from the MORE cohort had PINP, OC, BSAP, and CTx evaluated at baseline. Both doses of raloxifene significantly decreased (P < 0.001) all biochemical markers of bone turnover from baseline. Compared to baseline, PINP levels were decreased by medians of 11.0% and 40.8% in the placebo and pooled raloxifene groups, respectively. In addition, the placebo and pooled raloxifene groups decreased serum OC by 8.5% and 31.8%, BSAP by 15.8% and 34.6%, and urinary CTx/Cr excretion by 5.6% and 46.5%, respectively, from baseline. In the pooled raloxifene group, the logistic regression relationship between 3-year VF risk and 1-year percentage change for each biochemical marker was statistically significant with PINP (slope estimate = 0.0085, P = 0.009), OC (slope estimate = 0.0068, P = 0.035), and BSAP (slope estimate = 0.0056, P = 0.039), but not with CTx/Cr (slope estimate = 0.0027, P = 0.192). Furthermore, the percent decrease in PINP at 1 year could account for 28% of the total reduction in vertebral fracture risk. In conclusion, a 1-year decrease in PINP, BSAP, or OC, but not CTx/Cr, may be predictive of the 3-year VF risk reduction with raloxifene therapy in this subset of postmenopausal women with osteoporosis.

Aged↗
PubMed2004

Type II collagen peptides for measuring cartilage degradation.

This paper describes two new immunoassays for a peptide of the triple helix of type II collagen (Coll 2-1) and its nitrated form (Coll 2-1 NO(2)). In healthy subjects aged between 20 and 65 years old, Coll 2-1 and Coll 2-1 NO(2) levels in serum were in means 125.13+/-3.71 and 0.16+/-0.08 nmol/l, respectively. These levels did not significantly vary with age. However, up to 45 years of age, Coll 2-1 NO(2) levels in women were significantly higher than in men. In patients with knee osteoarthritis (OA), Coll 2-1 in serum was found to be elevated compared to healthy controls (267.45+/-26.42 nmol/l vs 126.78+/-6.61 nmol/l). Further, we have demonstrated that an increase of the urinary levels of Coll 2-1 or Coll 2-1 NO(2) over 1 year was predictive of joint space narrowing progression in OA patients. In conclusion, these preliminary results indicate that Coll 2-1 could be a predictive marker of knee OA progression.

Adult↗
PubMed2003

Reactive oxygen species downregulate the expression of pro-inflammatory genes by human chondrocytes.

OBJECTIVES: To determine the regulatory effects of reactive oxygen species (ROS) on the expression by human osteoarthritic chondrocytes of interleukin (IL)-1beta, -6 and -8, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) gene in response to interleukin (IL)-1beta or lipopolysaccharide (LPS). METHODS: Human chondrocytes in monolayer culture were incubated for 3 h with ROS generating molecules such as S-nitroso-N-acetyl-D,L-penicillamine (SNAP, 100 microM), 3-morpholinosydnonimine (SIN-1, 100 microM), with chemically synthesised peroxynitrite (ONOO-, 10 microM) or hydrogen peroxide (H2O2, 100 microM). After treatment by ROS, chondrocytes were washed and then cultured for the next 24 h with or without lipopolysaccharide LPS (10 microg/ml) or IL-1beta (1.10(-11) M). IL-1beta, IL-6, IL-8, iNOS and COX-2 gene expression was analysed by real time and quantitative RT PCR. IL-6, IL-8 and prostaglandin (PG) E2 productions were assayed by specific immunoassays. Nitrite was measured in the culture supernatants by the Griess procedure. RESULTS: LPS and IL-1beta stimulated IL-1beta, IL-6, IL-8, iNOS and COX-2 gene expression. SNAP significantly downregulated LPS induced overall gene expressions, whereas SIN-1 had no effect. ONOO- inhibited iNOS and COX-2 gene expression but not that of the cytokine genes. When chondrocytes were incubated with IL-1beta, SIN-1 and ONOO dramatically decreased all gene expressions while SNAP was inefficient. H2O2 treatment inhibited both LPS and IL-1beta induced gene expressions. CONCLUSIONS: These data provide an evidence that ROS may have anti-inflammatory properties by depressing inflammatory gene expression. Further, we demonstrate that ROS effects are dependent on the nature of radical species and the signalling pathway that is activated. These findings should be taken into consideration for the management of antioxidant therapy in treatment of inflammatory joint diseases.

Cartilage, Articular↗
PubMed2003

Subchondral tibial bone mineral density predicts future joint space narrowing at the medial femoro-tibial compartment in patients with knee osteoarthritis.

Preliminary studies have shown that dual-energy X-ray absorptiometry (DXA) produces images of sufficient quality for a precise and accurate measurement at density of the subchondral bone. The objective of this study was to investigate the relationship between baseline subchondral tibial bone mineral density (BMD) and joint space narrowing observed after 1 year at the medial femoro-tibial compartment of the knee joint. Fifty-six consecutive patients, from both genders, with knee osteoarthritis diagnosed according to the American College of Rheumatology criteria, were included in the study. Radiographic posteroanterior views were taken, at baseline and after 1 year of follow-up. Minimum joint space width (JSW) measurement, at the medial femoro-tibial joint, was performed with a 0.1-mm graduated magnifying lens. Baseline BMD of the subchondral tibial bone was assessed by DXA. The mean +/- SD age of the patients was 65.3 +/- 8.7 years, with a body mass index of 28.0 +/- 4.9 kg/m(2). The minimum JSW was 3.5 +/- 1.5 mm and the mean BMD of the subchondral bone was 0.848 +/- 0.173 g/cm(2). There was a significant negative correlation between subchondral BMD and 1-year changes in minimum JSW (r = -0.43, p = 0.02). When performing a multiple regression analysis with age, sex, body mass index, and minimum JSW at baseline as concomitant variables, BMD of the subchondral bone as well as JSW at baseline were independent predictors of 1-year changes in JSW (p = 0.02 and p = 0.005, respectively). Patients in the lowest quartile of baseline BMD (<0.73 g/cm(2)) experienced less joint space narrowing than those in the highest BMD quartile (>0.96 g/cm(2)) (+0.61 +/- 0.69 mm versus -0.13 +/- 0.27 mm; p = 0.03). Assessment of BMD of the subchondral tibial bone is significantly correlated with future joint space narrowing and could be used as a predictor of knee osteoarthritis progression.

Absorptiometry, Photon↗
PubMed2003

Is there any rationale for prescribing hormone replacement therapy (HRT) to prevent or to treat osteoarthritis?

BACKGROUND: During the last two decades of the 20th century, hormone replacement therapy (HRT) has been considered as the sole pharmacological approach for counterbalancing or mitigating the effects of estrogens deprivation in post-menopausal women. Subsequently, HRT has been widely recommended for the management of chronic diseases occurring, in women during the second half of their life. The overall risk/benefit ratio of estrogens has been recently reassessed in the light of long-term prospective studies failing to demonstrate the expected benefit of HRT on cardiovascular diseases incidence. Osteoarthritis (OA) is one of the chronic conditions for which HRT has been suggested to provide beneficial outcomes. RESULTS: The presence of estrogen receptors in human cartilage is no longer debated. However, cellular or animal models of OA do not provide an unequivocal pathway for the influence of gonadal steroids on cartilage. Similarly, studies attempting to correlate serum or urinary levels of sex steroids to the onset or progression of OA gave conflicting results. No randomized, prospective, controlled trial was designed to specifically assess the impact of hormone replacement therapy on symptomatic or structural progression of OA. Large-scale observational studies or trials designed to assess other potential benefits of estrogens suggest that HRT use does not provide symptomatic relief in OA but may interfere with its long-term structural progression, particularly in the lower limbs. CONCLUSION: Based on the recent results of the Women Health Initiative suggesting that HRT health risks may outweigh benefits, one can hardly recommend, with the current level of evidence, HRT as a first-line treatment against progression of OA.

Cartilage, Articular↗
PubMed2002

Expression of TGF-betas and their receptors is differentially modulated by reactive oxygen species and nitric oxide in human articular chondrocytes.

OBJECTIVES: To study the effects exerted by two antioxidants, N-monomethyl-L-arginine (L-NMMA), as an inhibitor of nitric oxide (NO) synthesis, and N-acetylcysteine (NAC), a reactive oxygen species (ROS) scavenger, on the expression of the major growth factor involved in cartilage repair, TGF-beta, under the three isoforms beta1, beta2 and beta3, and the receptors I and II of this factor, using lipopolysaccharide (LPS)-treated human chondrocytes in culture. METHODS: Suspension cultures of human chondrocytes derived from the knee of osteoarthritic patients were treated for 48 h with lipopolysaccharide (LPS) (10 microg/ml), L-NMMA (0.5 mM) or NAC (1 mM). Nitrite levels were assayed on the culture media using the Griess spectrophotometric method. After total RNA extraction, the expression of inducible NO synthase (iNOS), TGF-beta1, TGF-beta2, TGF-beta3, TGF-beta receptors I and II, was determined by semi-quantitative polymerase chain-reaction (RT-PCR). RESULTS: LPS induced a dramatic increase of both NO production and iNOS mRNA level. The addition of L-NMMA (0.5 mM) abolished NO production without affecting iNOS mRNA levels. In contrast NAC (1 mM) strongly synergized with LPS to stimulate NO synthesis. LPS treatment did not significantly alter TGF-beta1 expression whereas L-NMMA inhibited its production. TGF-beta2 mRNA level was decreased by LPS and was not changed in the presence of L-NMMA. On the other hand, NAC was capable of counteracting the LPS-induced inhibition of TGF-beta2 expression. TGFbeta3 mRNA level was markedly reduced by LPS alone, or with both L-NMMA and NAC. Finally, the expression of TGF-betaRI was slightly increased in the presence of combined LPS and L-NMMA or NAC whereas that of TGFbeta-RII was reduced in the same conditions. CONCLUSIONS: The modulation of TGF-beta system was found to be differentially controlled by NO and ROS productions. Indeed, the control exerted on TGF-beta expression varied according to the isoform: TGF-beta1 mRNA level depends on NO whereas that of TGF-beta2 is regulated by ROS and TGF-beta3 seems to be unaffected by both of them. The expression of TGF-beta receptors appeared to be modulated by NO and ROS levels. The relevance of the present findings to osteoarthritis (OA) physiopathology and the potential use of antioxidant therapy to treat this disease are discussed.

Acetylcysteine↗
PubMed2001

Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial.

BACKGROUND: Treatment of osteoarthritis is usually limited to short-term symptom control. We assessed the effects of the specific drug glucosamine sulphate on the long-term progression of osteoarthritis joint structure changes and symptoms. METHODS: We did a randomised, double-blind placebo controlled trial, in which 212 patients with knee osteoarthritis were randomly assigned 1500 mg sulphate oral glucosamine or placebo once daily for 3 years. Weightbearing, anteroposterior radiographs of each knee in full extension were taken at enrolment and after 1 and 3 years. Mean joint-space width of the medial compartment of the tibiofemoral joint was assessed by digital image analysis, whereas minimum joint-space width--ie, at the narrowest point--was measured by visual inspection with a magnifying lens. Symptoms were scored by the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index. FINDINGS: The 106 patients on placebo had a progressive joint-space narrowing, with a mean joint-space loss after 3 years of -0.31 mm (95% CI -0.48 to -0.13). There was no significant joint-space loss in the 106 patients on glucosamine sulphate: -0.06 mm (-0.22 to 0.09). Similar results were reported with minimum joint-space narrowing. As assessed by WOMAC scores, symptoms worsened slightly in patients on placebo compared with the improvement observed after treatment with glucosamine sulphate. There were no differences in safety or reasons for early withdrawal between the treatment and placebo groups. INTERPRETATION: The long-term combined structure-modifying and symptom-modifying effects of gluosamine sulphate suggest that it could be a disease modifying agent in osteoarthritis.

Administration, Oral↗
PubMed2001

In vitro effects of aceclofenac and its metabolites on the production by chondrocytes of inflammatory mediators.

OBJECTIVES: To investigate the mechanisms of action underlying the anti-inflammatory action of aceclofenac in vivo, we studied in vitro the effect of aceclofenac and its main metabolite, 4'-hydroxyaceclofenac, in comparison with diclofenac, another metabolite, on cyclooxygenases activity as well as interleukin-1beta, -6 and -8, nitric oxide, and prostaglandin E2 production by human osteoarthritic and normal articular chondrocytes. METHODS: Enzymatically isolated human chondrocytes were cultured for 72 h in the absence or presence of interleukin-1beta (IL-1beta) or lipopolysacharride (LPS) and with or without increased amounts (1 to 30 microM) of aceclofenac or metabolites. The production of different cytokines was measured by Enzyme Amplified Sensitivity Immunoassays (EASIA). Prostaglandin E2 was quantified by a specific radioimmunoassay. Nitrite and nitrate concentrations in the culture supernatants were determined by spectrophotometric method based upon the Griess reaction. Cyclooxygenase-2, inducible NO synthase and IL-1beta gene expression were quantified by reverse transcription of mRNA followed by real time and quantitative polymerase chain reaction. Finally, cyclooxygenase inhibitory potency of the drugs was also tested in both a cell-free system using purified ovine cyclooxygenase-1 and -2 (COX-1 and COX-2) and at a cellular level using human whole blood assay. RESULTS: We have demonstrated that aceclofenac, 4'-hydroxyaceclofenac and diclofenac significantly decreased interleukin-6 production at concentrations ranged among 1 to 30 microM and fully blocked prostaglandin E2 synthesis by IL-1beta- or LPS-stimulated human chondrocytes. Aceclofenac and diclofenac had no effect on interleukin-8 production while 4'-hydroxyaceclofenac slightly decreased this parameter at the highest dose (30 microM). Aceclofenac was without effect on IL-1beta- or LPS-stimulated nitric oxide production. At 30 microM, 4'-hydroxyaceclofenac inhibited both IL-1beta or LPS-stimulated nitric oxide production while diclofenac inhibited only the LPS-stimulated production. Finally, at 30 microM, the three drugs significantly decreased IL-1beta mRNA. In the whole blood test, aceclofenac and 4'-hydroxyaceclofenac weakly inhibited COX-1 with IC50 values superior to 100 microM, but decreased by 50% COX-2 activity at the concentration of 0.77 and 36 microM, respectively. Diclofenac strongly inhibited both COX-1 and COX-2 with IC50 values of 0.6 and 0.04 microM, respectively. On the other hand, aceclofenac and diclofenac weakly inhibited purified ovine cyclooxygenases with IC50 values superior to 100 microM, whereas 4'-hydroxyaceclofenac was without effect. CONCLUSIONS: These results suggest that aceclofenac actions are multifactorial and that metabolites could contribute to its anti-inflammatory actions.

Adult↗
PubMed2001

Bone resorption in post-menopausal women with normal and low BMD assessed with biochemical markers specific for telopeptide derived degradation products of collagen type I.

Biochemical markers of bone resorption can be used clinically to predict the risk of osteoporosis-related fractures (prognostic tool) and to assess the response of an osteoporotic patient to an antiresorptive therapy (monitoring tool). Our aim was to assess the ability of four currently marketed biochemical markers of bone resorption, based on the measurement of degradation products from collage type I telopeptides to monitor the elevated resorption associated with menopause. Women (846) were stratified for menopause, age, and bone mineral density and the following markers were measured: urinary cross-linked N-telopeptides of type I collagen (NTx), the levels of breakdown products of type I collagen C-telopeptides in serum (S-CTx), and in urine, by ELISA (U-CTx-E), and RIA (U-CTx-R). Furthermore, the ratio (alpha/beta) between the alphaL form of CTx measured in the CTx RIA and the betaL form measured in the ELISA was calculated. The mean difference was calculated for each marker in women with osteopenia (Op) or osteoporosis (PMO) (WHO definition) compared with healthy premenopausal (Pre) women and postmenopausal (N Post) women with normal bone mass. Serum CTx showed the highest elevation in post- compared with premenopausal women. All marker values were significantly higher in Op and PMO subjects compared with both Pre and to N Post women. Compared with premenopausal values, the largest elevation in both Op and PMO women was observed for serum CTx. Compared with N Post, urine NTx showed the highest increase in OP subjects. The alpha/beta CTx ratio was elevated in post- compared with Pre women, but there was no difference in the ratio among N Post, Op, or PMO women. In conclusion, postmenopausal women showed elevated turnover with all bone resorption markers, but with substantial individual variation in resorption levels. Furthermore, the turnover process in postmenopausal women appears to be quantitatively different from the premenopausal stage, apparent as altered alpha/beta CTx ratios.

Adult↗
PubMed2001

Symptoms modifying effect of avocado/soybean unsaponifiables (ASU) in knee osteoarthritis. A double blind, prospective, placebo-controlled study.

OBJECTIVES: We compare the symptomatic effects of 300 or 600mg daily of ASU in patients with knee osteoarthritis. METHODS: A multicenter, double blind, study comparing a daily intake of 300mg or 600mg of ASU and placebo. The study lasted 3 months and involved patients of both genders, aged 45 to 80 years and presenting with femoro-tibial knee osteoarthritis. The primary endpoint was NSAIDs and analgesics intake between D30 and D90. RESULTS: All efficacy parameters were significantly improved (p<0.01), in the two ASU groups compared to the placebo group. At D90, NSAIDs and analgesics intake decreased by more than 50% in 71% of the patients receiving ASU 300mg or 600mg, compared to 36% of the patients receiving placebo. From DO to D90 Lequesne's index dropped by 3.9 and 2.9 points in ASU 300mg and 600mg groups, respectively, against 1.6 in those receiving placebo. CONCLUSION: The efficacy of ASU at a dosage of 300mg/day and 600mg/day was consistently superior to that of placebo at all endpoints, with no differences observed between the two doses.

Aged↗
PubMed2001

Strontium ranelate increases cartilage matrix formation.

Based on previous studies showing that strontium ranelate (S12911) modulates bone loss in osteoporosis, it could be hypothesized that this drug also is effective on cartilage degradation in osteoarthritis (OA). This was investigated in vitro on normal and OA human chondrocytes treated or not treated with interleukin-1beta (IL-1beta). This model mimics, in vitro, the imbalance between chondroformation and chondroresorption processes observed in vivo in OA cartilage. Chondrocytes were isolated from cartilage by enzymatic digestion and cultured for 24-72 h with 10(-4)-10(-3) M strontium ranelate, 10(-3) M calcium ranelate, or 2 x 10(-3) M SrCl2 with or without IL-1beta or insulin-like growth factor I (IGF-I). Stromelysin activity and stromelysin quantitation were assayed by spectrofluorometry and enzyme amplified sensitivity immunoassay (EASIA), respectively. Proteoglycans (PG) were quantified using a radioimmunoassay. Newly synthesized glycosaminoglycans (GAGs) were quantified by labeled sulfate (Na2(35)SO4) incorporation. This method allowed the PG size after exclusion chromatography to be determined. Strontium ranelate, calcium ranelate, and SrCl2 did not modify stromelysin synthesis even in the presence of IL-1beta. Calcium ranelate induced stromelysin activation whereas strontium compounds were ineffective. Strontium ranelate and SrCl2 both strongly stimulated PG production suggesting an ionic effect of strontium independent of the organic moiety. Moreover, 10(-3) M strontium ranelate increased the stimulatory effect of IGF-I (10(-9) M) on PG synthesis but did not reverse the inhibitory effect of IL-1beta. Strontium ranelate strongly stimulates human cartilage matrix formation in vitro by a direct ionic effect without stimulating the chondroresorption processes. This finding provides a preclinical basis for in vivo testing of strontium ranelate in OA.

Cartilage↗