Objective. To characterize the doseresponsiveness of morphologic and biochemical chondral changes relative to mobility in mono-iodoacetate (MIA)-induced osteoarthritis (OA) in rats.Methods. Rat mobility was assessed by biotelemetry. Articular lesions were characterized by macroscopic and histologic examinations. Cartilage proteoglycan metabolism was evaluated by the 1,9-dimethylmethylene blue dye binding assay and by radiosulfate incorporation in patellar cartilage.Results. Spontaneous locomotor activity was rapidly, transiently, and dose-dependently decreased after MIA injection into rat knees (primary response). Thereafter, only high doses (0.3 mg and 3.0 mg) led to a secondary progressive long-term loss of spontaneous mobility on day 15, when subchondral bone was exposed. These 2 doses resulted in significant changes in cartilage proteoglycan concentration at day 15 and a strong inhibition of anabolism in the peripheral patellae by day 2, contrasting with the effects of lower doses (0.01, 0.03, and 0.1 mg).Conclusion. When a suMicient dose of MIA is used, this model can easily and quickly reproduce OA-like lesions and functional impairment in rats, similar to that observed in human disease. These parameters, as well as proteoglycan metabolism, could serve as indicators for studying chondroprotective drugs, or

Objective. To determine the magnetic resonance imaging (MRI), macroscopic, and microscopic characteristics of synovial membrane inflammation, to study the relationship between disease severity and the degree of synovial inflammation on MRI and on macroscopic and microscopic examination, and to look for colocalization of chondral lesions and synovial inflammation.Methods. Thirty-nine patients with knee osteoarthritis (OA) were classified into 2 groups according to the severity of cartilage lesions as revealed by chondroscopy. Group 1 (n ‫؍‬ 14) had mild cartilage lesion(s) without exposure of subchondral bone. Group 2 (n ‫؍‬ 25) had severe cartilage lesion(s) with focal or diffuse exposure of subchondral bone. Synovitis was evaluated on T1-weighted MRI sequences according to the degree of synovial thickening on a 4-point scale (ranging from 0 to 3) in 5 regions of interest. Synovial membrane was macroscopically scored, and biopsies were performed on the 5 preselected sites for histologic scoring.Results. The mean ؎ SD synovial thickening score on MRI was 1.55 ؎ 0.90, with no significant difference between groups 1 and 2. Intra-and interobserver reproducibility of the total synovial score was excellent, and interobserver reproducibility of the MRI grade was good. Conclusion. Synovitis may be present from the onset of OA and may be evaluated on MRI. MRI evaluation of synovitis could be used to classify OA patients in clinical trials and could help to identify those who could benefit from synovium-targeted therapy.Osteoarthritis (OA) is the most prevalent form of arthritis and a major cause of disability worldwide (1).

Chondrocalcinosis (CC) is a common cause of joint pain and arthritis that is caused by the deposition of calcium-containing crystals within articular cartilage. Although most cases are sporadic, rare familial forms have been linked to human chromosomes 8 (CCAL1) or 5p (CCAL2) (Baldwin et al. 1995; Hughes et al. 1995; Andrew et al. 1999). Here, we show that two previously described families with CCAL2 have mutations in the human homolog of the mouse progressive ankylosis gene (ANKH). One of the human mutations results in the substitution of a highly conserved amino acid residue within a predicted transmembrane segment. The other creates a new ATG start site that adds four additional residues to the ANKH protein. Both mutations segregate completely with disease status and are not found in control subjects. In addition, 1 of 95 U.K. patients with sporadic CC showed a deletion of a single codon in the ANKH gene. The same change was found in a sister who had bilateral knee replacement for osteoarthritis. Each of the three human mutations was reconstructed in a full-length ANK expression construct previously shown to regulate pyrophosphate levels in cultured cells in vitro. All three of the human mutations showed significantly more activity than a previously described nonsense mutation that causes severe hydroxyapatite mineral deposition and widespread joint ankylosis in mice. These results suggest that small sequence changes in ANKH are one cause of CC and joint disease in humans. Increased ANK activity may explain the different types of crystals commonly deposited in human CCAL2 families and mutant mice and may provide a useful pharmacological target for treating some forms of human CC.

This study shows that a calibrated slight or moderate exercise exerts a beneficial influence on the severity of chondral lesions in ACLT rats. Conversely, a strong effort abolishes this chondroprotective effect. This effect could be related to a reduced level of chondrocyte apoptosis through anti-apoptotic capacities of stress-induced Hsp70 overexpression.

Since the antipyretic and probably the analgesic effects of paracetamol are, at least in part, centrally mediated, its plasma and cerebrospinal fluid (CSF) concentrations were measured in 43 patients with nerve-root compression pain. Each subject was given a short i.v. infusion of 2 g propacetamol, a prodrug which is hydrolysed to paracetamol within 7 min. Single blood and CSF samples were drawn concomitantly in each patient at intervals between 20 min and 12 h. Maximum CSF drug concentrations were observed at the 4th hour, subsequent concentrations exceeding those in plasma. The elimination half-life of paracetamol calculated from pooled data was shorter in plasma (2.4 h) than in CSF (3.2 h). The time-course of paracetamol in CSF may parallel that of analgesic effect.

Obese males with a history of cardiovascular disease receiving ongoing beta-blocker treatment and undergoing surgery in an emergency setting were at high risk of a fatal outcome after NMBA-induced anaphylaxis. Some epinephrine-resistant cases may play a role in our high mortality rate. New therapeutic approaches need to be developed to treat these cases.

We assessed the time-course of adjuvant arthritis (AA) in Lewis rats, using biotelemetry to monitor the rat’s spontaneous locomotor activity and body temperature, and studied the evolution of the arthritic index, circulating concentrations of inflammation-promoting cytokines, cartilage proteoglycan synthesis, and the effect of indomethacin as a cyclooxygenase inhibitor to evaluate prostaglandin (PG) contribution in AA. The injection of complete Freund’s adjuvant on day 0( D0) induced a marked, transient loss of locomotor activity ( D1– D4; initial phase) and then a second phase of hypomobility peaking on D15 and thereafter irreversible ( D16– D20; arthritic phase). Fever peaked first on D1 and again between D13 and D17. The primary hyperthermia was associated with increases in plasma interleukin-6 and tumor necrosis factor-α concentrations and seemed to be partly PG dependent. Proteoglycan synthesis inhibition in the patellar cartilage increased gradually, spreading from the injected paw to the contralateral paw. It was corrected on D20 by preventive and curative indomethacin treatments. Indomethacin also greatly relieved hypomobility during the systemic phase of AA ( D10– D15). The combination of information about cartilage metabolism, body temperature, locomotor activity, and cytokine in this study permits analysis of analgesic, antipyretic, anti-inflammatory, and chondroprotective properties of drugs in the various phases of AA. Thus, using a new methodology, we have discriminated the different phases of the disease and confirmed the symptomatic and systemic inhibitory effect of indomethacin on fever, activity, and cartilage metabolism.

Aseptic meningitis associates a typical clinical picture of meningitis with the absence of bacterial or fungal material in the cerebrospinal fluid. Drug-induced aseptic meningitis (DIAM) may be due to two mechanisms: (i) a direct meningeal irritation caused by the intrathecal administration of drugs and (ii) an immunologic hypersensitivity reaction to a systemic administration. If the direct meningeal irritation allows a rather easy recognition, the immunologic hypersensitivity reaction is a source of challenging diagnostics. DIAM linked to a systemic treatment exerts typically an early onset, usually within a week. This period can be shortened to a few hours in case of drug rechallenge. The fast and spontaneous regression of clinical symptoms is usual after stopping the suspected drug. Apart from these chronological aspects, no specific clinical or biological parameters are pathognomonic. CSF analysis usually shows pleiocytosis. The proteinorachia is increased while glycorachia remains normal. Underlying pathologies can stimulate the occurrence of DIAM. Thus, systemic lupus erythematosus appears to promote DIAM during NSAID therapy, especially ibuprofen-based one. Similarly, some patients with chronic migraine are prone to intravenous immunoglobulin-induced aseptic meningitis. DIAM will be mainly evoked on chronological criteria such as rapid occurrence after initiation, rapid regression after discontinuation, and recurrence after rechallenge of the suspected drug. When occurring, positive rechallenge may be very useful in the absence of initial diagnosis. Finally, DIAM remains a diagnosis of elimination. It should be suggested only after all infectious causes have been ruled out.