Effect of three animal models of inflammation on nerve fibres in the synovium.

Objectives: Both sensory and sympathetic nerve fibres are depleted in the synovium in rheumatoid arthritis (RA). The hypothesis that the induction of an inflammatory response in the synovium is capable of causing depletion of nerve fibres was tested.

Methods: To investigate this phenomenon experimental arthritis in the rat was induced by three different methods and the synovium was examined for evidence of nerve depletion by immunocytochemistry.

Proteolysis of human native and oxidised alpha 1-proteinase inhibitor by matrilysin and stromelysin.

Matrilysin is shown to rapidly inactivate alpha 1PI, an inhibitor of elastase, by cleaving the Pro357-Met358 peptide bond of its reactive centre. The rate of inactivation of alpha 1PI by matrilysin is four times higher than stromelysin. Matrilysin cleaves oxidised alpha 1PI at the Phe352-Leu353 bond, whilst stromelysin cleaves oxidised alpha 1PI at the Met358-Ser359 bond.

Arthritogenic potential of the 65 kDa stress protein--an experimental model.

Objectives: To assess the effect of an intra-articular presentation of stress (heat shock) proteins (hsp) on joint inflammation.

Methods: Wistar rats were sensitised with a suspension of heat killed Mycobacterium tuberculosis in oil in the scruff of the neck and challenged intra-articularly with stress protein or M tuberculosis preparations. Inflammation was assessed by joint swelling and, using immunohistology, cellular infiltration of the synovium and antibody induction by an enzyme-linked immunosorbent method.

Circulating IgA antibody against a 65 kDa heat shock protein in acute alcoholic hepatitis.

Heat shock proteins are known to be immunogenic in a number of diverse conditions and can be induced by hypoxia, tumour necrosis factor and alcohol--all potential triggers in patients with acute alcoholic hepatitis. In the present study, sera from 23 patients with acute alcoholic hepatitis, 18 liver disease controls, ten patients with inactive alcoholic liver disease and six alcoholics without liver damage were screened for the antibody to a 65 kDa heat shock protein using an ELISA technique. IgA antibody was found to be closely associated with alcoholic hepatitis; 20/23 patients were seropositive compared to 5/18 liver disease controls and 4/10 with inactive alcoholic cirrhosis.

Helicobacter pylori stimulates antral mucosal reactive oxygen metabolite production in vivo.

To determine if reactive oxygen metabolites have a pathogenic role in Helicobacter pylori (H pylori) related gastroduodenal disease, this study measured their production in antral mucosal biopsy specimens. Two related chemiluminescence techniques were used comparing H pylori positive (n = 105) and negative patients (n = 64) with a similar spectrum of macroscopic disease. After chemiluminescence assays, biopsy specimens were graded histologically.

Syphilitic placentitis: an immunopathy.

The placentas of eight infants with congenital syphilis were examined by both immunohistochemical and immunofluorescent techniques. Significant IgM, C3 and rheumatoid factor reactivity were observed in all the syphilitic placentas. We postulate that their presence plays an important role in the evolution of the pathological changes.

Proinflammatory effects of morphine in the rat adjuvant arthritis model.

Morphine has been shown to alter various aspects of the immune response. We examined its effect on progression of the T-cell-mediated model, rat adjuvant arthritis. Saline, morphine or the opioid antagonist naloxone were administered to male Wistar rats via subcutaneous osmotic pumps implanted three days prior to adjuvant disease induction by an intra-dermal injection of Mycobacterium tuberculosis in oil.

Monoarthritis in the rat knee induces bilateral and time-dependent changes in substance P and calcitonin gene-related peptide immunoreactivity in the spinal cord.

Bilateral changes in the spinal cord and dorsal root ganglion content of the sensory peptides substance P and calcitonin gene-related peptide have been previously reported in animal models of arthritis which affect many joints within the body. The central nervous system has been implicated in the symmetry of joint involvement in human rheumatoid arthritis. We aimed to determine whether unilateral inflammation of the knee joint can also induce bilateral changes in the spinal cord.

Osteoclast function and its control.

Bone resorption appears to be dependent on a range of processes. It requires an adequate number of osteoclasts to access bone mineral. These osteoclasts must be activated by a mechanism which is dependent upon prior osteoblastic stimulation.

Stress proteins in colorectal mucosa. Enhanced expression in ulcerative colitis.

Stress (heat shock) proteins are ubiquitous intracellular proteins that can be induced in vitro by physiological stress events that occur during inflammation. We have used an indirect immunoperoxidase method to locate 60-kDa stress proteins in biopsies taken from normal and inflamed colorectal mucosa. An anti-60-kDa monoclonal antibody (ML30) produced specific staining of surface epithelial cells localized to the site of the Golgi apparatus.

Microvascular substance P binding to normal and inflamed rat and human synovium.

The regulatory peptide substance P has been implicated in the development and persistence of inflammatory synovitis. The authors used quantitative in vitro receptor autoradiography to compare synovial binding of 125Iodine-Bolton Hunter-labeled substance P ([125I]BH-SP) in rats and humans and between uniflamed and persistently inflamed synovium. [125I]BH-SP binding to microvascular endothelium paralleled the distribution of substance P-immunoreactive nerves and had characteristics of the neurokinin (NK) 1 class of tachykinin receptor.

A comparative evaluation of the metabolic profiles of normal and inflammatory knee-joint synovial fluids by high resolution proton NMR spectroscopy.

High resolution 1H NMR spectroscopy has been employed to investigate the metabolic profile of healthy human knee-joint synovial fluid (SF) and the biochemical data acquired have been compared with those of matched serum, and inflammatory knee-joint SF samples. Results obtained indicate that the healthy human knee-joint has a hypoxic status (high lactate level when expressed relative to that of paired serum) that is milder than that of the inflamed human knee-joint. Moreover, normal SF differs from that of inflammatory SF in that it contains little or no NMR-detectable lipoprotein-associated fatty acids and 'acute-phase' glycoproteins, an observation reflecting the limited passage of these macromolecules from plasma into the synovial space in healthy subjects.

Presence of foam cells containing oxidised low density lipoprotein in the synovial membrane from patients with rheumatoid arthritis.

Objective: Increased concentrations of lipid peroxidation products have been described in the serum and synovial fluid from patients with rheumatoid arthritis. A large proportion of the unsaturated lipids in human extracellular fluids is a component of low density lipoprotein (LDL). The oxidative modification of LDL, and its subsequent uptake by macrophages, has been implicated in the pathogenesis of atherosclerosis, but not of rheumatoid arthritis.

Oxidative DNA damage and cellular sensitivity to oxidative stress in human autoimmune diseases.

Objectives: To estimate the extent of genomic DNA damage and killing of lymphocytes by reactive oxygen intermediates in autoimmune diseases.

Methods: 8-Oxo-7-hydrodeoxyguanosine (8-oxodG), a promutagenic DNA lesion induced by reactive oxygen intermediates, was measured by high performance liquid chromatography, coupled with electrochemical detection, in hydrolysates of DNA which had been extracted from lymphocyte and polymorphonuclear leucocyte fractions of human blood. In addition, human primary blood lymphocytes stimulated by concanavalin A were assayed for cytotoxicity induced by hydrogen peroxide on day 0, by assessing cell proliferation during seven days of culture.

Free radicals in inflammation: second messengers and mediators of tissue destruction.

In recent years it has become increasingly apparent that, in man, free radicals play a role in a variety of normal regulatory systems, the deregulation of which may play an important role in inflammation. As examples, we discuss the second messenger roles of: NO in the regulation of vascular tone, O2.- in fibroblast proliferation and H2O2 in the activation of transcription factors such as NF kappa B.

Hepatic 60-kD heat-shock protein responses in alcoholic hepatitis.

The precise mechanism of the pathogenesis of alcoholic hepatitis is unknown, but immune involvement may perpetuate and exacerbate the process. Heat-shock proteins, normally protective, may be immunogenic and have been shown to induce antibody formation in some inflammatory conditions. Alcohol, cellular hypoxia and tumor necrosis factor, all involved in alcoholic hepatitis, are potent inducers of heat-shock protein.

High resolution proton NMR investigations of rat blood plasma. Assignment of resonances for the molecularly mobile carbohydrate side-chains of 'acute-phase' glycoproteins.

An intense broad resonance at 2.14 ppm present in high field (400, 500 and 600 MHz) Hahn spin-echo 1H-NMR spectra of rat blood plasma, but absent from those of human blood plasma is attributable to the presence of terminal O-acetylsialate sugars in the molecularly mobile carbohydrate side-chains of 'acute-phase' glycoproteins (predominantly alpha 1-acid glycoprotein). The presence of such alternative acetylsugars in the carbohydrate side-chains of rat plasma glycoproteins are of much physiological and experimental significance in view of the regular use of these animals in model systems of human inflammatory conditions.

Cellular biology of bone resorption.

Past knowledge and the recent developments on the formation, activation and mode of action of osteoclasts, with particular reference to the regulation of each individual step, have been reviewed. The following conclusions of consensus have emerged. 1.

Neuropeptide degrading enzymes in normal and inflamed human synovium.

Regulatory peptides, including neuropeptides, are metabolized by membrane-bound peptidases. We have localized the membrane peptidases angiotensin-converting enzyme (ACE), dipeptidyl peptidase IV (DPPIV), and aminopeptidase M (APM) in normal and inflamed human synovium by immunohistochemistry and enzyme histochemistry. ACE was localized to endothelial cells of all vessels, whereas endothelial DPPIV and APM were restricted to veins and capillaries of some cases.

Inactivation of synovial fluid alpha 1-antitrypsin by exercise of the inflamed rheumatoid joint.

alpha 1-Antitrypsin (alpha 1AT) is known to be oxidised by reactive oxygen species both in vitro and in vivo, leading to its inactivation. We report here that synovial fluid (SF) alpha 1AT is inactivated during exercise of the knee-joints of rheumatoid arthritis (RA) patients. Sequential SF sampling from exercised RA patients showed a marked decrease in the mean activity of alpha 1AT after exercise with no change in the molecular forms of alpha 1AT.

An imaginative approach to synovitis--the role of hypoxic reperfusion damage in arthritis.

The rheumatoid joint is hypoxic. The loss of the physiologic defense mechanism, reflex muscle inhibition, allows the generation of high intraarticular pressures, particularly during exercise. Hypoxia alters the biochemistry of the synovium and encourages the production of reactive oxygen species (ROS) on reperfusion of blood.