Antisense oligonucleotides to the integrin receptor subunit alpha(5) decrease fibronectin fragment mediated cartilage chondrolysis.

Objective: To investigate involvement of the integrin alpha(5) subunit of the classical fibronectin receptor in cartilage chondrolytic activities of fibronectin fragments (Fn-f).

Design: Bovine chondrocytes and cartilage explants were cultured in the presence of antisense oligonucleotide (ASO), or sense (SO) or scrambled sequence oligonucleotide (SCO) corresponding to the bovine alpha(5) subunit. The effects of the oligonucleotides on mRNA and protein expression of the alpha(5) subunit were analysed by rtPCR and Western blotting, respectively.

The antinociceptive and histologic effect of sciatic nerve blocks with 5% butamben suspension in rats.

Unlabelled: Butamben, a lipophilic local anesthetic of the ester class, produces a differential nerve block of long duration. Epidural and peripheral nerve blocks with butamben, formulated as a 5%--10% suspension, result in prolonged analgesia without significant motor blockade. We evaluated the effect of butamben sciatic nerve block on antinociception using the rat paw formalin test, as well as withdrawal latencies to thermal stimulation, and assessed histologic changes in the nerve.

Molecular basis for differences between human joints.

The molecular program of a cell determines responses including induction or inhibition of genes for function and activity, and this is true of the cells within articular cartilage, a major functional component of the joint. While our studies have previously focussed on differences in the molecular programs of the cells within the superficial and deep zones, we have recently begun to focus on relative differences between joints, such as the knee and ankle. In the human, these joints vary greatly in their susceptibility to joint diseases, such as osteoarthritis (OA).

A single injection of fibronectin fragments into rabbit knee joints enhances catabolism in the articular cartilage followed by reparative responses but also induces systemic effects in the non-injected knee joints.

Objective: To investigate effects on cartilage metabolism and degeneration of injection of fibronectin fragments (Fn-fs) into rabbit knee joints.

Design: The knees of adolescent New Zealand white rabbits were intraarticularly injected with rabbit Fn-fs. Cartilage sections from both injected and non-injected joints were treated with Safranin-O, with antibodies to the VDIPEN and NITEGE neoepitopes of degraded aggrecan and to matrix metalloproteinase-3 (MMP-3).

Increased resistance to collagen-induced arthritis in CD44-deficient DBA/1 mice.

Objective: To study the role of CD44, the principal hyaluronan (HA) receptor, in experimental arthritis.

Methods: We generated CD44 gene deficiency in arthritis-susceptible DBA/1LacJ mice to study the role of CD44 directly in collagen-induced arthritis (CIA). Wild-type and CD44-deficient mice were immunized with chicken type II collagen, and the onset and severity of CIA were monitored up to day 64.

Cartilage damage by matrix degradation products: fibronectin fragments.

Catabolic cytokines play a major role in cartilage degradation not only in rheumatoid arthritis but also in osteoarthritis. Although the major source in rheumatoid arthritis may be mononuclear cells and synovial tissue and the cause of release may be multifactorial, the source of cytokines in osteoarthritis would be mostly from chondrocytes. However, there are few explanations of how upregulation of the cytokines might occur in osteoarthritis.

Gene expression by human articular chondrocytes cultured in alginate beads.

Culture of articular chondrocytes in alginate beads offers several advantages over culture in monolayer; cells retain their phenotype for 8 months or longer. Earlier studies of chondrocytes cultured in alginate concentrated on collagen and proteoglycan synthesis. However, gene expression by in situ hybridization (ISH) has not been investigated.

Del1: a new protein in the superficial layer of articular cartilage.

Articular cartilage contains four distinct zones, extending from the surface to the subchondral bone. Freshly isolated chondrocytes from the superficial zone of articular cartilage retain a collagenase-P-resistant cell-associated matrix. In the studies described here, the protein Del1 was identified as a component of the cell-associated matrix of superficial zone chondrocytes from adult bovine articular cartilage.

Impaired Fas signaling pathway is involved in defective T cell apoptosis in autoimmune murine arthritis.

Proteoglycan (PG)-induced arthritis (PGIA) is a novel autoimmune murine model for rheumatoid arthritis induced by immunization with cartilage PG in susceptible BALB/c mice. In this model, hyperproliferation of peripheral CD4(+) T cells has been observed in vitro with Ag stimulation, suggesting the breakdown of peripheral tolerance. Activation-induced cell death (AICD) is a major mechanism for peripheral T cell tolerance.

Cell attachment, collagen binding, and receptor analysis on bovine articular chondrocytes.

The purpose of this study was to investigate collagen receptors on primary bovine articular chondrocytes from full-thickness and different layers of bovine articular cartilage. Cytometric studies with antibodies showed that approximately 56% of the chondrocytes from the superficial layer and 29% of the chondrocytes from the deep layer bound anti-annexin V. A similar tendency was found for alpha5 and beta1 integrin antibodies.

Tumor necrosis factor-alpha induced DNA cleavage in human articular chondrocytes may involve multiple endonucleolytic activities during apoptosis.

Apoptosis has been documented in chondrocytes both in the growth plates of young, healthy cartilages and in osteoarthritic cartilages; little, however, is known about apoptosis in chondrocytes of normal adult articular cartilage. For the current study, apoptosis in adult chondrocytes was evaluated by labeling DNA fragments using the ISEL in situ end labeling of 3'-recessed strand breaks) or TUNEL (5'-recessed or blunt-ended strand breaks with terminal deoxynucleotidyl transferase-mediated nick end labeling) techniques in primary cultures of chondrocytes in monolayer. Apoptosis was induced in the chondrocytes by either Tumor Necrosis Factor alpha (TNF alpha), Interleukin 1-beta (IL-1 beta), or anti-Fas antibody but only after 48 hours in culture.

Magnesium sulfate potentiates morphine antinociception at the spinal level.

Unlabelled: Intrathecal magnesium sulfate coinfusion with morphine increases antinociception in normal rats; however, because magnesium also delays the onset of tolerance, it is not clear whether this additional antinociception is a result of potentiated analgesia or tolerance abatement. We examined the antinociceptive interaction of intrathecal (IT) bolus magnesium sulfate and morphine in morphine naive rats and those with mechanical allodynia after a surgical incision. After intrathecal catheter implantation, rats were given preinjections of magnesium or saline, followed by injections of morphine or saline.

Differential effects of interleukin-1 on hyaluronan and proteoglycan metabolism in two compartments of the matrix formed by articular chondrocytes maintained in alginate.

Phenotypically stable young adult bovine articular chondrocytes suspended in beads of alginate gel were first cultured for 5 days, using daily changes of medium containing 10% fetal bovine serum and supplements. The cells in the beads were then maintained in culture for a further 3 days in the presence or absence of interleukin-1alpha at 1 ng/ml in the daily change of medium. The exposure to interleukin-1alpha caused the incorporation of (35)S-sulfate into the predominant cartilage proteoglycan, aggrecan, to decrease by approximately 60%.

Hyaluronan suppresses fibronectin fragment-mediated damage to human cartilage explant cultures by enhancing proteoglycan synthesis.

Hyaluronic acid, recently renamed hyaluronan, has been used as a therapeutic intervention in the treatment of osteoarthritis. We have reported that high-molecular-weight (800 kDa) hyaluronan is effective in blocking the catabolic action of fibronectin fragments in explant cultures of bovine cartilage and in an experimental in vivo model of damage to the rabbit knee joint. The fibronectin fragments induce catabolic cytokines in human cartilage, which, in turn, suppress proteoglycan synthesis and induce matrix metalloproteinases to decrease the proteoglycan content.

Aprotinin pretreatment diminishes postischemic myocardial contractile dysfunction in dogs.

Unlabelled: We evaluated the effect of aprotinin, administered before the onset of acute regional myocardial ischemia, on reversible contractile dysfunction induced by ischemia and reperfusion in pentobarbital-anesthetized dogs. Animals were randomized to receive either aprotinin 30,000 kallikrein inactivator units (KIU)/kg and 7000 KIU x kg(-1) x hr(-1) (n = 8) or equivalent volumes of 0.9% sodium chloride (n = 7) IV 60 min before a 15-min interruption of circumflex coronary artery blood flow and then reperfusion.

Anaesthetic management of a patient with erythropoietic protoporphyria for ventricular septal defect closure.

Erythropoietic protoporphyria (EPP) is due to a deficiency in ferrochelatase required for haem synthesis. We describe the anaesthetic management of a seven-year-old with EPP undergoing closure of a haemodynamically significant ventricular septal defect. Photosensitivity in EPP patients is triggered at wavelengths near 400 nm and light-excited porphyrins generate free radicals and singlet oxygen that lead to erythrocyte deformity and haemolysis.

Characteristics of an extended internal fixation system for polysegmental transpedicular reduction and stabilization of the thoracic, lumbar, and lumbosacral spine.

The Kluger internal fixator, with its artificial fulcrum outside the operative site, had to be extended for multisegmental use. Three different prototypes, called Central Bar (CB), Double Bar I (DB I) and Double Bar II (DB II) were designed, which were fully compatible with the existing reduction system. To evaluate the ability of these newly developed systems to provide primary stability in a destabilized spine, their stiffness characteristics and stabilizing effects were investigated in multidirectional biomechanical stability tests and compared with those of the clinically well-known Cotrel-Dubousset (CD) system.

Immunodetection and partial cDNA sequence of the proteoglycan, superficial zone protein, synthesized by cells lining synovial joints.

We have previously described a large proteoglycan named superficial zone protein that was isolated and purified from culture medium of superficial slices of bovine articular cartilage. Monoclonal antibodies were raised against superficial zone protein and used as probes in Western blot analyses for immunohistochemical studies both to determine precisely which cells within the joint synthesize the proteoglycan and to isolate a cDNA fragment from a bovine chondrocyte lambdagt11 library that encodes part of the proteoglycan. The cDNA fragment that was obtained with use of monoclonal antibody 6-A-1 encodes the 3' end of the sequence for superficial zone protein.

Expression of anchorin CII (cartilage annexin V) in human young, normal adult, and osteoarthritic cartilage.

In its tissue-specific function as a collagen receptor of chondrocytes, cartilage annexin V (anchorin CII) occupies a key position in the organization of the cell-extracellular matrix (ECM) junction for the tissue. The general role of annexin V (Anx V) in other tissues suggests involvement in cellular secretory processes and in regulation of apoptosis. Immunohistochemical analysis of Anx V in growth plate cartilage, confirmed by in situ hybridization, suggests that Anx V is prominently expressed and forms a major constituent of growth plate chondrocytes.

Cartilage damaging activities of fibronectin fragments derived from cartilage and synovial fluid.

Objective: To investigate whether fibronectin fragments (Fn-fs), shown to damage cultured cartilage, can be found in cartilage from patients with osteoarthritis (OA) or rheumatoid arthritis, or can be generated from fibronectin (Fn) within synovial fluids or from Fn in the matrix of cultured cartilage. To also determine whether cartilage or synovial fluid Fn-fs are active and, thus, could contribute to cartilage damage in vivo.

Methods: Fn-fs were immunochemically identified in cartilage extracts from patients with OA or rheumatoid arthritis or in bovine cartilage cultured with IL-1 alpha or in bovine synovial fluids treated with stromelysin-1 (MMP-3).

Intrathecal bupivacaine reduces pruritus and prolongs duration of fentanyl analgesia during labor: a prospective, randomized controlled trial.

Unlabelled: Pruritus is a frequent complication (40%-100%) of intrathecal (IT) fentanyl 25 microg (F) for labor analgesia. The addition of IT bupivacaine 2.5 mg (B) to F has been reported in a nonrandomized series to have a 17.

Cultured human ankle and knee cartilage differ in susceptibility to damage mediated by fibronectin fragments.

According to numerous cadaveric, radiographic, and clinical studies, ankle and knee joints differ in susceptibility to osteoarthritis. To test for biochemical differences in susceptibility to damage, a chondrocytic chondrolysis system has been utilized. In this system, fibronectin fragments are added to cultured cartilage explants, resulting in enhanced release of catabolic cytokines, induction of matrix metalloproteinases, temporary suppression of proteoglycan synthesis, and consequently, severe loss of cartilage proteoglycan.

A new culture system to study the metabolism of the intervertebral disc in vitro.

Study Design: This study determined whether entrapment of a rabbit intervertebral disc in alginate gel helped to promote the retention of normal metabolic activities by the nucleus pulposus and anulus fibrosus in tissue culture.

Objectives: To establish an in vitro culture system to study the metabolism of the intervertebral disc as a whole integral organ.

Summary Of Background Data: In vitro studies of the metabolism of intervertebral discs have been scarce because of the difficulties involved in maintaining the integrity of the tissues, especially that of the nucleus pulposus, in culture medium.

ADAM-10 message is expressed in human articular cartilage.

The depletion of the pericellular and territorial matrices in articular cartilage is considered to be one of the earliest events in pathobiology of osteoarthritis (OA). A newly discovered family of proteins with a disintegrin-like and metalloproteinase-like domain (ADAM) may be involved in matrix degradation as well as in cell-cell and cell-matrix interactions. The purpose of this study was to determine by in situ hybridization whether human articular chondrocytes from newborn, normal adult, and OA cartilages express messenger RNA for ADAM-10, one of the members of this family, and by semiquantitative RT-PCR to compare the levels of this expression.

Exposure of cartilage to a fibronectin fragment amplifies catabolic processes while also enhancing anabolic processes to limit damage.

The addition of fibronectin fragments to cultured cartilage causes an initial suppression of proteoglycan synthesis, induction of matrix metalloproteinases, and resultant decrease in proteoglycan content by about 50% during the first few days in culture. Because the proteoglycan loss appears to be limited, we investigated whether the fibronectin fragments induce anabolic responses that might counter the damage. The effects of various lengths of exposure of cultured cartilage to the fibronectin fragment on proteoglycan content, proteoglycan synthesis rates, stromelysin-1 release, and tumor necrosis factor-alpha, interleukin-1alpha, and interleukin-6 release were investigated.