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Biomedical subjects

M Ristola

Publications and source records attributed to M Ristola.

At least 19 recordsLinked to original sources
PubMed2001

Neutrophil free oxygen radical production and blood total antioxidant capacity in patients with coronary heart disease using various medications.

Despite convincing results of studies in vitro, less is known about the effects of antioxidants on in vivo redox balance in humans. We developed a novel parameter of in vivo redox balance, and studied it and its relation to dental infections in 51 patients on medication for coronary heart disease (CHD) and 39 random controls matched for age group, sex, social class and locality. In vivo redox balance was the ratio of plasma antioxidant capacity, as measured with radical-trapping assay, to neutrophil respiratory burst capacity, as measured with whole blood chemiluminescence assay. Dental infections were quantitated with four rating scales. CHD patients had higher values than controls. Patients on acetosalicylic acid (ASA), diuretics or beta blockers, but not the ones on calcium channel blocker, had significantly higher redox balance than non-users. Combination of calcium channel blockers and ASA was associated with redox balance similar to taking beta blockers or diuretics. Diuretics and ASA were independent determinants of redox balance in multivariate analyses. Redox balance did not correlate with severity of dental infections (Spearman's r 0.06 to 0.11). The results contrast experimental data indicating that calcium channel blockers are as antioxidants superior to other cardiovascular drugs. Total antioxidant capacity in parallel with oxygen species production capacity should be considered in attempts to solve the antioxidant paradox.

Adrenergic beta-Antagonists↗
PubMed1999

Isolation of mycobacteria from indoor swimming pools in Finland.

The presence of mycobacteria in seven indoor pools in Finland was evaluated by multiple culture methods. Replicate samples, with and without inactivation of chlorine by sodium thiosulfate, were cultured in two laboratories. Laboratory I used two methods: (A) no decontamination and (B) cetylpyridinium chloride (0.005%, 20 min); and Laboratory II two methods: (C) cetylpyridinium chloride (0.005%, 18 h) and (D) oxalic acid (5%, 15 min). Samples processed by methods (A) and (B) were cultured on different egg media of pH 6.3 or 5.8; by method (C) on Middlebrook and Cohn 7H10 (+OADC) agar of pH 5.5; and by method (D) on Middlebrook and Cohn 7H10 agar (+OADC) with cycloheximide (500 microg/ml). Mycobacteria were recovered from five (71%) of seven pools. Detection of mycobacteria depended on the method used. High isolation rates (36-46% of the samples) were obtained by methods (A), (B) and (D). Contamination was a problem only with method (A). Inactivation of chlorine had a variable impact on mycobacterial detection. Isolates included M. kansasii, M. gordonae, M. fortuitum complex, M. sphagni, and M. vaccae, as well as M. simiae-like and M. chubuense-like organisms. In addition, a group of slowly growing and a group of rapidly growing isolates with previously unknown fatty acid and alcohol composition were isolated. No M. avium was detected. Mycobacterial counts were highest in a small pool with high temperature, low pH, and low content of free available chlorine.

Finland↗
PubMed1997

Hepatitis A outbreak amongst intravenous amphetamine abusers in Finland.

This article describes a widespread outbreak of hepatitis A virus (HAV) infection amongst drug abusers in Finland. Although attempts to demonstrate the virus in amphetamines failed, the infection was assumed to be linked to intravenous use of the drug. The unusual mode of transmission prompted us to analyse possible atypical clinical features as well as the spread of the virus to the general population, nowadays practically without protective immunity. Serologically verified cases that occurred in Helsinki were interviewed, their hospital records were analysed and their contacts were serology tested. Amphetamine lots, as well as faecal samples from patients, were examined with RT-PCR. Detailed information was obtained from 238 subjects, among whom 131 admitted drug abuse and 67 cases were classified as secondary cases. Phylogenetic analysis of virus strains from HAV-infected cases suggested a common origin, and epidemiological observations linked it with particular lots of amphetamine. Three cases died, and 3 presented with severe clinical disease. Icterus was more common among i.v. drug abusers than others. Infection with hepatitis A virus was probably related to the faecal contamination of amphetamine associated with the transportation of the drugs in the gastrointestinal tract.

Adult↗
PubMed1995

Inhaled recombinant interferon gamma in patients with lung cancer: pharmacokinetics and effects on chemiluminescence responses of alveolar macrophages and peripheral blood neutrophils and monocytes.

PURPOSE: A Phase I trial was conducted to investigate clinical toxicity, pharmacokinetics, and chemiluminescence (CL) responses of alveolar macrophages (AM) and peripheral blood neutrophils and monocytes after inhalation of recombinant interferon (r IFN)-gamma. METHODS AND MATERIALS: Eight patients with lung cancer inhaled r IFN-gamma as single doses of 0.1, 0.2, 0.6, 1.8, or 5.4 mg. Bronchoalveolar lavage was performed three times, 21 h before as well as 3 and 27 h after inhalation. RESULTS: Interferon-gamma was detectable in bronchoalveolar lavage fluid (BALF) samples taken 3 h after inhalation in doses of > or = 0.6 mg. Before inhalation, AM in four out of seven patients studied showed vigorous lucigenin-enhanced CL responses to N-formyl-methionyl-leucyl-phenylalanine and opsonized zymosan particles. Furthermore, the responses were markedly increased 3 h after inhalation. In three out of seven patients, AM in the pretreatment BALF samples showed low or no CL responses, and the responses did not increase after inhalation of IFN-gamma, suggesting that the patients were anergic. Postinhalation CL responses did not correlate with the dose of IFN-gamma inhaled. Circulating IFN-gamma was detected in one patient receiving the highest dose. No changes referable to IFN-gamma inhalation were found in the CL responses of blood neutrophils and monocytes. During the 24 h follow-up, two patients developed transient fever-reactions. CONCLUSIONS: The findings suggest that inhalation may provide a way to increase alveolar concentrations of IFN-gamma and to augment respiratory burst capacity of AM without any major side effects. This approach may have clinical implications for the treatment of tumors and infections of the respiratory tract.

Adult↗
PubMed1994

Reactive oxygen species of neutrophils from patients with monosomy 7 in the bone marrow: contradictory chemiluminescence activity by whole blood or by purified cells.

Monosomy 7, a deletion of the long arm of chromosome 7, was shown in the neutrophils of peripheral blood in 5 of 6 patients with a myelodysplastic syndrome or leukemia who had monosomy 7 in their bone marrow cells. In a chemiluminescence assay the production of reactive oxygen species by neutrophils from patients was increased in whole blood and decreased in purified cells, which suggests that neutrophils with monosomy 7 tolerate poorly the cell purification procedures used. The in vitro migration of purified neutrophils obtained from patients with monosomy 7 was impaired. It is known that patients with monosomy 7 have an increased susceptibility to infections. It is possible that neutrophils with monosomy 7 are too easily triggered to a full-scale respiratory burst and thereby the cells exhaust their ability to eliminate invading microbes efficiently.

Adult↗
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↗
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

Increased oxygen radical production determined by whole blood chemiluminescence in patients with previous Yersinia arthritis.

Luminol-dependent whole blood chemiluminescence (CL) was studied in patients with previous yersinia arthritis (YA). Patients showed significantly higher CL responses compared to healthy controls regardless of HLA-B27 antigen when either N-formyl-methionyl-leucyl-phenylalanine or opsonized zymosan particles were used a stimulus. This hyperreactivity may well play a role in the development of inflammatory injury in YA.

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

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↗