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Biomedical subjects

H Repo

Publications and source records attributed to H Repo.

At least 19 recordsLinked to original sources
PubMed1992

Oxygen radical production and trapping in subjects with previous Yersinia infection.

Previous studies indicate that oxygen radical production by 1-min activation of N-formyl-methionyl-leucyl-phenylalanine-induced chemiluminescence (CL) by whole blood is increased in subjects with previous Yersinia arthritis (YA). This finding is confirmed in the present study and extended further by demonstrating that subjects with previous YA show increased oxygen radical generation and enhanced release of myeloperoxidase from neutrophils and increased CL activity by serum, all factors that can contribute to an increase in the initial activation of CL. Initial activation was not increased in subjects who had had Yersinia enteritis without arthritis; however, intracellular oxygen radical production by purified neutrophils was significantly increased, suggesting that the cells had been primed in vivo. The water-soluble antioxidants of plasma samples tested by a peroxyl radical-trapping assay were much the same in subjects with previous YA, in subjects with previous Yersinia enteritis without arthritis, and in healthy subjects. The results suggest that aberrations in neutrophil oxygen radical production play a role in the pathogenesis of YA.

Adult↗
PubMed1992

Gut and spondyloarthropathies.

There is a link between gut and spondyloarthropathies, which extends from the acute ReA triggered by enteritis due to gram-negative bacteria to ankylosing spondylitis and peripheral arthritis in association with Crohn's disease and ulcerative colitis. In addition, in studies using ileocolonoscopy, an unexpectedly high proportion of patients with prolonged or chronic seronegative oligoarthritis or sacroiliitis have inflammatory changes in the terminal ileum or colon or both. These changes have either features of acute gut inflammation or infection, but about one quarter of the patients have chronic lesions, probably early Crohn's disease. The conventional treatment of spondyloarthropathies consists of liberal use of NSAIDs, local corticosteroid injections if indicated, and physiotherapy. In patients with acute ReA, the conventional antimicrobial therapy to eradicate the triggering infection is necessary if there is evidence of chlamydial or gonococcal etiology. This therapy does not, however, influence the course of the subsequent arthritis. Patients with chlamydia arthritis probably host living bacteria for prolonged periods, and they seem to benefit from a prolonged antimicrobial therapy with tetracyclines. In the face of frequent gut involvement in patients with prolonged or chronic spondyloarthropathies, the use of sulfasalazine is the logical alternative, as short-term studies on patients with ankylosing spondylitis indicate.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1991

Double-blind, placebo-controlled study of three-month treatment with lymecycline in reactive arthritis, with special reference to Chlamydia arthritis.

We conducted a double-blind, placebo-controlled, randomized study of 3-month treatment with lymecycline, a form of tetracycline, in reactive arthritis (ReA). Lymecycline therapy significantly decreased the duration of the illness in patients with Chlamydia trachomatis-triggered ReA, but not in other ReA patients. In 2 ReA patients, C trachomatis was found in the throat, an uncommon locale for this organism. Our results suggest that it is important to verify the triggering microbe and that it is beneficial to treat Chlamydia arthritis patients with a prolonged course of tetracycline.

Adult↗
PubMed1991

Increased whole blood chemiluminescence in patients with Shwachman syndrome: therapy trial with thiamine and alpha-tocopherol.

Neutrophils purified from peripheral blood of patients with the Shwachman syndrome show enhanced chemiluminescence (CL) and depressed chemotaxis. Here we present data showing that the increased CL response can be demonstrated by using a whole blood CL assay. This assay is well-suited for studies in infants, because the blood sample volumes needed are small. Increase in CL was most distinct in the initial (1 min) activation induced by N-formyl-methionyl-leucyl-phenylalanine. The 1-min response is considered to derive from extracellular production of oxygen radicals. Such an extracellular oxygen radical production may render the patients susceptible to undue oxidant stress. We therefore treated the patients with two antioxidants, thiamine and alpha-tocopherol, for 3 months. This supplementation, however, failed to exert any significant effect on either whole blood CL or migration of the patients' neutrophils under agarose.

Antioxidants↗
PubMed1991

Determination of oxygen radical production in spondyloarthropathies by whole blood chemiluminescence.

Oxygen derived free radicals are considered to play an important part in the development of inflammation. A whole blood chemiluminescence assay was used to study N-formyl-methionyl-leucyl-phenylalanine induced oxygen radical production in subjects with ankylosing spondylitis or previous yersinia arthritis. In luminol enhanced chemiluminescence, the subjects with previous yersinia arthritis showed significantly increased initial activation (at one minute), whereas the subjects with ankylosing spondylitis showed decreased responses at both the initial activation and at peak activation (at two to three minutes). This finding gives credence to the view that, in terms of oxygen radical production, the pathogenesis of yersinia arthritis is different from that of ankylosing spondylitis.

Acridines↗
PubMed1990

Phagocyte function in familial hypercholesterolaemia: peripheral blood monocytes exposed to lipopolysaccharide show increased tumour necrosis factor production.

We studied functions of polymorphonuclear leucocytes (PMN) and monocytes from peripheral blood of subjects with familial hypercholesterolaemia (FH). FH monocytes exposed to Escherichia coli lipopolysaccharide (LPS) in 10% human AB serum generated tumour necrosis factor (TNF) significantly more than did control monocytes. After lowering of serum low-density lipoprotein (LDL) levels by drug treatment, FH monocytes exposed to LPS in the absence of exogenous lipoproteins generated significantly more TNF than did control monocytes. These findings suggest that increased TNF production is not affected by hypolipidaemic treatment and may not derive from differences between uptake of exogenous LDL by FH monocytes and control cells. Chemotaxis, chemokinesis, and random migration of both FH PMN and FH monocytes were normal, as determined by agarose assay and membrane filter assay. FH PMN showed increased luminol-enhanced chemiluminescence in response to 2.5 x 10(-8) M, but not to 2.5 x 10(-6) M, N-formyl-methionyl-leucyl-phenylalanine, and not to serum-treated zymosan or to phorbol myristate acetate. Luminol- and lucigenin-enhanced chemiluminescence responses of FH monocytes were normal. In summary, the major aberration found in the present study was that FH monocytes stimulated with LPS show enhanced production of TNF. The possibility that exaggerated TNF production contributes to an early development of atherosclerotic lesions in FH subjects warrants further studies.

Adult↗
PubMed1990

Phagocyte function in juvenile periodontitis.

We studied the chemotaxis of peripheral blood polymorphonuclear leukocytes (PMNs) and monocytes and the production of tumor necrosis factor alpha by monocytes of patients with juvenile periodontitis (JP). As a group, the patients' PMNs showed significantly increased chemotaxis determined by counting the number of migrating cells within a 3-microns-pore-size filter. Determined as distance of migration within the filter, as chemotactic increment based on checkerboard analysis, as leukotactic index calculated on the basis of distance of migration and cell count at different depths within a 3-microns-pore-size filter, as distance of migration under agarose, and as the number of PMNs migrating across a 5-microns-pore-size filter, the chemotactic migration rates of PMNs of patients were similar to those of controls. Evaluation of the data on an individual basis suggested that in terms of PMN chemotaxis some patients were hyperresponsive and some were hyporesponsive. Chemotaxis, spontaneous migration, and the rates of lipopolysaccharide-induced tumor necrosis factor alpha production by JP monocytes were similar to those of control cells. Our results give credence to the view that there are minor aberrations in the functions of JP phagocytes, but the extent to which these aberrations are relevant to accumulation of PMNs at sites of infection and inflammation in vivo and possibly contribute to the pathogenesis of JP remains unclear.

Adolescent↗
PubMed1990

Chemotaxis and chemiluminescence responses of synovial fluid polymorphonuclear leucocytes during acute reactive arthritis.

The chemotaxis and chemiluminescence responses of polymorphonuclear leucocytes (PMN) of synovial fluid and peripheral blood from patients with acute reactive arthritis were studied. Rates of chemotactic and chemokinetic migration of synovial fluid PMN were significantly decreased. In addition, chemiluminescence responses tended to be depressed, suggesting that the cells were deactivated for both chemotaxis and production of oxygen derived free radicals. Such deactivation has been described previously as a characteristic of synovial fluid PMN in rheumatoid arthritis. Compared with those with a mild disease, patients with severe acute reactive arthritis had higher chemiluminescence responses of synovial fluid PMN to phorbol myristate acetate during acute disease and developed increased migration of peripheral blood PMN towards zymosan treated serum after recovery from the disease. This supports the view that hyperreactive PMN contribute to the development of severe inflammatory symptoms in acute reactive arthritis.

Acute Disease↗
PubMed1990

Enhanced inflammatory reactivity in the pathogenesis of spondyloarthropathies.

Pathogenesis of seronegative spondyloarthropathies such as ankylosing spondylitis and reactive arthritis is not known. Growing evidence indicates that microbial structures such as Chlamydia antigen and Yersinia antigen are present in the inflamed joints of patients with reactive arthritis. Microbial antigens can activate the host's inflammatory mechanisms. After the activation, the course of inflammation can be postulated to be affected by the host factors responsible for amplification of the inflammatory reaction and elimination of the foreign structures. Thus, the amplification, whether strong, moderate, or weak, may contribute to the degree of inflammatory tissue injury in patients with seronegative spondyloarthropathies. This review will discuss the role of increased inflammatory reactivity in the pathogenesis of HLA-B27 associated spondyloarthropathies, with special reference to reactive arthritis triggered by yersinia enteritis.

Animals↗
PubMed1989

Diagnosis of falciparum malaria delayed by long incubation period and misleading presenting symptoms: life-saving role of manual leucocyte differential count.

In countries where malaria is not endemic the diagnosis of the disease is often delayed or overlooked, particularly if the clinical symptoms are atypical and if automated cell analyzers are used instead of blood films for leucocyte differential counts. We report 2 cases of severe Plasmodium falciparum malaria with unusual clinical features: a 46-year-old man with an exceptionally long incubation period and a 22-year-old woman with presenting symptoms suggesting viral hepatitis. In both cases the diagnosis of malaria was unexpectedly made by observant laboratory technicians examining stained blood films for differential counts.

Adult↗
PubMed1989

Luminol-enhanced chemiluminescence of whole blood. Statistical analysis, and comparison of the responses of different subjects.

We studied the effects of different variables on luminol-enhanced chemiluminescence (CL) of whole blood, induced by N-formyl-methionyl-leucyl-phenylalanine (FMLP), opsonized zymosan particles (OZP), or phosphate buffered saline (PBS). Use of correction factor based on blood neutrophil count and hemoglobin concentration decreased interindividual variation and improved normality of the frequency distributions of CL responses. In FMLP- and PBS-induced CL, day-to-day variation was not significant, but it was significant in OZP-induced CL. Although storage of blood samples for 8 hours decreased CL, the decrease was not evident in a study of initial activation, i.e. CL measured at one minute after application of FMLP. Our results suggest that FMLP-induced initial activation is well suited for epidemiological studies because it is easy to determine and is affected neither by day-to-day variation nor by storage of the blood samples for a few hours.

Adult↗
PubMed1988

Chronic osteomyelitislike disease with negative bacterial cultures.

During a seven-year period we observed 14 children who had chronic osteomyelitislike disease. The bacterial cultures from the bone lesions were negative. In eight patients the findings were compatible with chronic recurrent multifocal osteomyelitis (CRMO), in four the findings were compatible with chronic sclerosing osteomyelitis of Garré, and two had osteomyelitis of the clavicle. In patients with CRMO, lymphocyte subpopulations, the responses to mitogens, and the chemotactic and chemokinetic responses showed no consistent abnormalities. After a mean follow-up of 4.5 years (range, one to ten years), all four patients with osteomyelitis of Garré were symptomatic, and two had complications. Only two of the eight patients with CRMO had active disease. The course had been complicated by growth disturbances in one patient and by thoracic outlet syndrome in another. Wegener's granulomatosis later developed in a patient with CRMO.

Adolescent↗