Influence of glucosamine sulphate on oxidative stress in human osteoarthritic chondrocytes: effects on HO-1, p22(Phox) and iNOS expression.

OBJECTIVE: Reactive oxygen species (ROS) are major determinants in the alteration of articular cartilage. Among protective cellular mechanisms, the inducible isoform of haem oxygenase (HO-1) plays a particularly relevant role. On the other hand, the enzymatic activity of the Nicotinamide adenine dinucleotide phosphate (NADPH) system could contribute to the generation of ROS. Glucosamine sulphate (GS) is one of the drugs used in the treatment of osteoarthritis; however, its mechanism of action is still largely unknown. The aim of the present study was to investigate the effects of GS on primary human chondrocytes in vitro, in particular with regard to HO-1, p22(Phox) (a subunit of NADPH complex) and inducible nitric oxide synthase (iNOS) expression. METHODS: Primary human chondrocytes were treated with different concentrations of GS; gene expression of HO-1, p22(Phox) and iNOS was assessed by the reverse transcriptase-polymerase chain reaction method. In a separate set of experiments, the cells were stimulated with human recombinant interleukin (IL)-1beta and simultaneously treated with GS. Moreover, HO-1 protein and total nitrite production were evaluated. RESULTS: HO-1 gene expression was up-regulated (+40% with respect to the controls, P < 0.001) by 10 mmol/l GS at 24 h, while p22(Phox) gene expression was down-regulated by 10 mmol/l GS with a maximum inhibitory effect observed after 48 h treatment. IL-1beta stimulation induced expression of iNOS reverted by 1 and 10 mmol/l GS. Moreover, HO-1 gene expression was down-regulated by IL-1beta and 10 mmol/l GS restored baseline values. These data were confirmed by evaluating HO-1 protein level and nitrite production. CONCLUSIONS: The influence of GS on oxidative stress observed in this study discloses a possible new mechanism of action and seems to be in keeping with a potential protective effect on chondrocyte population.

YKL-40 in human lumbar herniated disc and its relationships with nitric oxide and cyclooxygenase-2.

UNLABELLED: The basic pathophysiology of intervertebral disc degeneration and low back pain remains unclear. It has been hypo-thesized a role of biochemical mediators of inflammation and tissue degradation in intervertebral disc degeneration and herniation. Chitinase 3-like protein 1 (YKL-40) is a glycoprotein mainly secreted by chondrocytes which has been proposed as a possible marker of inflammation and/or cartilage alterations. OBJECTIVE: To investigate the YKL-40 presence in human lumbar disc tissue culture and its possible relationships with some substances relevant in inflammation such as cyclooxygenase-2 (COX-2) and nitric oxide (NO). PATIENTS AND METHODS: We analyzed lumbar discs from 19 patients who underwent surgery for lumbar disc herniation at L4-L5 or L5-S1 levels. The specimens were cultured and incubated for 72 hours. At the end of incubation, the supernatants were assayed for presence and concentration of YKL-40, COX-2 and NO. RESULTS: YKL-40 was detectable in all the samples analyzed. Mean (+/-SD) concentration was 1.54+/-1.29 ng/ml/mg compared to dry weight. COX-2 and NO levels were 25.25+/-11.42 pg/ml/mg and 1.3+/-1.8 microM/mgx10(-2), respectively. A correlation was found between YKL-40 and COX-2 (r=0.579, p<0.05) and YKL-40 and NO (r=0.509, p<0.05). CONCLUSION: To our knowledge, this is the first report demonstrating YKL-40 release by intervertebral disc culture. It may contribute to better clarify the role of this protein in the pathophysiology of discal degeneration and inflammation as confirmed by its relationships with COX-2 and NO in disc tissue culture.

Anatomy of the deep fascia of the upper limb. Second part: study of innervation.

Analysis of specimens taken from different areas of the deep fascia in 20 upper limbs was made in order to establish which kind of nerve fibres and endings are present in the deep muscular fascia. The flexor retinaculum and the lacertus fibrosus were also evaluated because they are anatomically hardly separable from the deep muscular fascia, although they have different functions. In particular, specimens were taken at the level of: (a) the expansion of pectoralis major onto the bicipital fascia, (b) the middle third of the brachial fascia, (c) the lacertus fibrosus, (d) the middle third of the antebrachial fascia, (e) the flexor retinaculum. This study demonstrated an abundant innervation of the fascia consisting in both free nerve endings and encapsulated receptors, in particular, Ruffini and Pacini corpuscles. However, differences in innervation were verified: the flexor retinaculum was resulted the more innervated element whilst lacertus fibrosus and the pectoralis major expansion the less innervated. These results suggest that the retinaculum has more a perceptive function whereas the tendinous expansions onto the fascia have mostly a mechanical role in the transmission of tension. The hypothesis that the fascia plays an important role in proprioception, especially dynamic proprioception, is therefore advanced. In fact, the fascia is a membrane that extends throughout the whole body and numerous muscular expansions maintain it in a basal tension. During a muscular contraction these expansions could also transmit the effect of the stretch to a specific area of the fascia, stimulating the proprioceptors in that area.

[Synoviocyte cultures from synovial fluid]. / Realizzazione di colture di sinoviociti da liquido sinoviale.

UNLABELLED: The study of the pathogenetic mechanisms of rheumatic diseases is in general carried out through "in vitro" systems based on cellular cultures models. The difficulties to achieve fresh human tissue prompted us to develop a simpler method to obtain fibroblast-like synovial cells from synovial fluid (SF). METHODS: SF was collected from the knees of 5 patients with rheumatoid arthritis (RA), 4 with osteoarthritis (OA) and 5 with psoriatic arthritis (PsA). The pellet obtained after centrifugation was resuspended in DMEM/HamF12 containing 10% foetal calf serum, 1% peni-streptomycin, 4 ng/ml of fibroblast grow factor and incubated at 37 degrees C in T25 culture flasks. Synoviocytes were also obtained from fresh synovial membranes (SM) by explants technique. Both types of cells were characterized by immunocytochemistry and their inflammatory response to synthetic monosodium urate crystals was studied through the measurement of nitric oxide (NO). RESULTS: Adherent synoviocytes were obtained from the culture of 2/5 SF from RA, 4/4 SF from OA and 5/5 SF from PsA. Synoviocytes isolated from both SF and SM expressed surface antigens CD90, CD55, and the intracellular prolyl-4-hydroxylase. Morphologically, the cells showed the typical spindle-shape fibroblast-like appearance. NO levels induced by UMS crystals in SF synoviocytes were similar to those obtained in SM synoviocytes. CONCLUSION: Adherent cells obtained from SF showed the phenotype and the reactivity of tissue synoviocytes. Due to the easy accessibility of SF, this method may represents an useful alternative when synovial tissues is not promptly available.

Pro-inflammatory interleukins in the synovial fluid of rheumatoid arthritis associated with joint hypermobility.

BACKGROUND: Joint hypermobility (JH) is frequently seen in rheumatology; in some cases, such as rheumatoid arthritis (RA), it may represent a worsening of disease evolution. The aim of our study was to evaluate the influence of joint hypermobility on RA synovial fluid (SF) inflammation. Patients and methods. One hundred consecutive adult patients with RA and joint effusion of the knee were examined for the presence of JH. In the SF we evaluated volume, the number of white blood cells (WBC) and the levels of interleukin (IL)-1beta, IL-6 and IL-8 and prostaglandin E2 (PGE2). RESULTS: JH was associated with RA (JH-RA) in 18 patients, all of whom were female. Compared with non-JH RA, all the SF indices found in JH-RA were higher, although significant differences were observed only for volume, IL-8 and PGE2. CONCLUSION: In JH-RA, increased joint mobility seems to be associated with a more severe local inflammatory response, which may contribute to the more erosive evolution observed in our patients.

Psoriatic arthritis exacerbated by Salmonella infection.

Psoriatic arthritis (PsA) is an inflammatory joint disease in which environmental factors, particularly trauma and infections, are thought to play an important role. The authors describe the case of a patient with a mild and long-untreated form of PsA which was severely exacerbated by Salmonella typhimurium infection. This case confirms the importance of infectious agents in the occurrence and course of PsA.

Tryptophan catabolism in synovial fluid of various arthropathies and its relationship with inflammatory cytokines.

Synovial fluids (SF) from patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), gout, and osteoarthritis (OA) were investigated for the levels of interleukin (IL)-1 beta, IL-6 and IL-8, tryptophan (Trp) and indoleamine 2,3-dioxygenase (IDO) activity. Significant differences exist in the levels of IL-1 beta between inflammatory arthritides RA, PsA and gout and non inflammatory arthritis, such as OA. The highest concentration of IL-1 beta was found in RA, that showed high levels also of IL-6 and IL-8. In the same disease we also found the highest IDO activity and the lowest Trp concentration. In addition, IDO activity seems to be related with the decrease in Trp, as demonstrated by the inverse correlation found between these two substances in the SF of all patients.