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Biomedical subjects

H Arvilommi

Publications and source records attributed to H Arvilommi.

At least 73 records · Page 4Linked to original sources
PubMed1985

Synthesis of human immunoglobulins in vitro: comparison of two assays of secreted immunoglobulin.

One consequence of B-lymphocyte activation is immunoglobulin production, which can be quantitated by various techniques. We have compared assay of plaque forming cell (PFC) and determination of immunoglobulins by ELISA in culture supernatants of human lymphocytes stimulated with pokeweed mitogen and with Staphylococcus aureus. These assays correlated well (r greater than 0.77) in all major immunoglobulin classes studied. The close correlation suggests that determination of secreted immunoglobulins by ELISA may be substituted for the PFC assay.

B-Lymphocytes↗
PubMed1984

High-performance liquid chromatographic determination of tocopherols and tocotrienols and its application to diets and plasma of Finnish men. II. Applications.

The composed one-day diets and plasma of 40 Finnish men screened for a selenium supplementation study were analyzed for tocopherols and tocotrienols. The men were divided into a low-Se group (in the screening phase plasma Se levels less than 70 micrograms/l and plasma alpha-tocopherol levels less than 1.2 mg/100 ml) and a high-Se group (plasma Se greater than 70 micrograms/l, plasma alpha-tocopherol not determined before the study). In the low-Se group plasma levels of alpha-tocopherol averaged 0.97 +/- 0.18 mg/100 ml. The daily dietary intake of alpha-tocopherol was 6.1 +/- 2.7 mg and that of total vitamin E 7.3 +/- 3.1 mg of alpha-tocopherol equivalents. In the high-Se group the corresponding average values were 1.16 +/- 0.21 mg of alpha-tocopherol/100 ml of plasma, 8.8 +/- 4.3 mg of alpha-tocopherol/day and 10.3 +/- 5.1 mg of alpha-tocopherol equivalents/day. The overall average for the contribution of alpha-tocopherol to the total dietary tocopherols was 44.6 +/- 11.0%. In the plasma samples alpha-tocopherol accounted for 92.0 +/- 2.1%, beta-tocopherol for 2.7 +/- 0.7% and gamma-tocopherol for 5.3 +/- 2.1% of the total amount of tocopherols.

Canada↗
PubMed1983

Bioavailability of selenium to Finnish men as assessed by platelet glutathione peroxidase activity and other blood parameters.

Three groups of 10 men of low selenium status were given 200 micrograms Se/day as Serich wheat, Se-rich yeast, or sodium selenate for 11 wk. Twenty unsupplemented subjects served as controls. Plasma Se levels increased steadily in the wheat and yeast groups for 11 wk without plateauing, whereas in the selenate group, plasma Se plateaued around 110 ng/ml after 4 wk. Platelet glutathione peroxidase (GSH-Px) activities increased rapidly in the wheat and selenate groups for 4 wk and then plateaued. Platelet GSH-Px increased more slowly in the yeast group. Ten weeks after the supplements were discontinued, platelet GSH-Px was higher in the wheat and yeast groups than in the selenate group. Assessment of Se bioavailability requires a short-term platelet GSH-Px measurement to determine immediate availability, a medium-term plasma Se measurement to estimate retention, and a long-term platelet GSH-Px measurement after supplements are discontinued to determine the covertibility of tissue Se stores to biologically active Se.

Adult↗
PubMed1983

Selenium and immune functions in humans.

Earlier animal experiments have shown that selenium depletion may decrease immune functions. In this human study, 40 volunteers from a population with low serum selenium concentrations were supplemented with selenium or placebo for 11 weeks. Blood samples were drawn at intervals for analysis of selenium status and immune function. At the end of the supplementation period, plasma selenium levels were 74 ng/ml in the placebo group and 169 ng/ml in the supplemented group. The improvement in selenium status was associated with a 57% increase in the activity of platelet glutathione peroxidase in the group supplemented with selenium, but there was no increase in the activity of this enzyme in the placebo-treated subjects. Immune function was measured in vitro by tests of lymphocyte and granulocyte activity. Intracellular killing of Staphylococcus aureus by granulocytes was slightly lower in the placebo group than in the selenium group at the end of the supplementation period (77.2 compared to 85.2%; P less than 0.05). No significant changes were observed in phagocytosis, chemotactic factor generation, antibody or leukocyte migration inhibitory factor production by lymphocytes, or proliferative responses to phytohemagglutinin or concanavalin A. These results suggest that the selenium deficiency of the order found in Finland and some other areas of the world has little, if any, influence on the immune functions measured in this study.

Adult↗
PubMed1983

Comparison of cefuroxime and gentamicin in combination with metronidazole in the treatment of peritonitis due to perforation of the appendix.

A study on 42 surgical patients was carried out to find out whether cefuroxime may be substituted for gentamicin in combination with metronidazole in the treatment of peritonitis secondary to perforation of appendix. All patients recovered and there were four wound infections in each group. Both aerobic and anaerobic bacteria were cultured in the peritoneal fluid in 69% of cases and anaerobes only in 19% of the patients. Postoperatively the patients were followed up for one month. The mean length of the hospital stay and convalescence did not differ significantly. There was also no difference in the time to the removal of gastric suction, laboratory measurements and the incidence of pyrexia between the study groups. Although the number of patients was limited the present study indicates that gentamicin may be replaced by less toxic cefuroxime. This is especially the case if there are several risk factors in the use of gentamicin and if there is not a possibility for monitoring the serum levels of gentamicin.

Adult↗
PubMed1982

Cell walls, peptidoglycans, and teichoic acids of Gram-positive bacteria as polyclonal inducers and immunomodulators of proliferative and lymphokine responses of human B and T lymphocytes.

In this study the mitogenic and immunomodulating effects of bacterial cell wall preparations were investigated. Cell walls, peptidoglycans, and teichoic acids from Bacillus subtilis and Staphylococcus aureus Wood 45 activated both human T cells (supplemented with 10% monocytes) and B cells to proliferate and to produce leukocyte-inhibitory factor. Similar results were obtained with adult and umbilical cord blood cells, suggesting that these bacterial preparations were acting as mitogens. Cell walls and peptidoglycans had a modulating effect on purified protein derivative- or protein A-induced proliferation. In the presence of suboptimal concentrations of these stimulants, bacterial components enhanced the proliferative response. However, at optimal concentrations of purified protein derivative or protein A, bacterial components suppressed lymphocyte proliferation. Peptidoglycans solubilized by lysozyme activated B lymphocytes but not T cells. Solubilization had no effect on the immunomodulating capacity.

B-Lymphocytes↗
PubMed1982

Synthesis of IgM, IgG and IgA in rheumatoid arthritis.

We studied the production of immunoglobulins by lymphocytes separated from the blood of 15 rheumatoid arthritis (RA) patients, of 12 patients suffering from other connective tissue diseases (CTD), and of 18 healthy controls. The production of IgM, IgG and IgA in pokeweed-mitogen-stimulated cultures was measured by counting the number of plaque-forming cells (PFC) and by determining the concentration of secreted immunoglobulins by means of an enzyme immunoassay. Synthesis of immunoglobulins, particularly IgM and IgG, was lower than in other CTD patients or controls. The IgM response of RA patients was 20% and 29% (PFC and Ig concentrations) that of the controls. The respective figures for IgG were 33% and 53% and for IgA 61% and 72%.

Adult↗
PubMed1982

Polyclonal response of human lymphocytes to bacterial cell walls, peptidoglycans and teichoic acids.

It has been found earlier that many bacteria are polyclonal activators of human lymphocytes. This phenomenon was further analysed by preparing cell walls, peptidoglycans and teichoic acids from Staphylococcus aureus Wood 46 and Bacillus subtilis and studying their capacity to stimulate human adult and newborn lymphocytes to proliferate and to produce leucocyte inhibitory factor (LIF). All these bacterial surface components acted as polyclonal activators. In our opinion these findings further strengthen the view that in infections there are a variety of bacterial products capable of inducing a polyclonal response of the host.

Adult↗
PubMed1981

Cell walls, peptidoglycans, and teichoic acids of gram-positive bacteria as polyclonal inducers and immunomodulators of proliferative and lymphokine responses of human B and T lymphocytes.

In this study, the mitogenic and immunomodulating effects of bacterial cell wall preparations were investigated. Cell walls, peptidoglycans, and teichoic acids from Bacillus subtilis and Staphylococcus aureus Wood 46 activated both human T cells (supplemented with 10% monocytes) and B cells to proliferative and to produce leukocyte migration inhibitory factor. Similar results were obtained with adult and umbilical cord blood cells, suggesting that these bacterial preparations acted as mitogens. Cell walls and peptidoglycans had a modulating effect on purified protein derivative-induced and protein A-induced proliferation. In the presence of suboptimal concentrations of these stimulants, bacterial components enhanced the proliferative response. However, at optimal concentrations of purified protein derivative or protein A, bacterial components suppressed lymphocyte proliferation. Peptidoglycans solubilized by lysozyme activated B lymphocytes but not T cells. Solubilization had no effect on immunomodulating capacity.

Age Factors↗
PubMed1980

Polyclonal activation of human lymphocytes by bacteria.

The proliferative response of human unseparated lymphocytes, T cells, and B cells to various bacterial strains was investigated. All the bacteria tested induced a proliferative response in unseparated lymphocytes and B cells. T cells were stimulated only after reconstitution with monocytes. Stimulation of umbilical cord blood lymphocytes suggests that the response is polyclonal. We interpret these and previous data as an indication of a common mechanism of resistance against infectious diseases.

B-Lymphocytes↗
PubMed1980

Cellular interactions in spontaneous or autologous cell-induced proliferative and lymphokine responses of human lymphocytes.

Purified human B cells were activated in cultures in the absence of any intentional stimulants as judged by lymphokine synthesis and proliferation. These responses were not augmented by monocytes. Lymphokine production (LIF) was increased in the presence of T cells. Autologous mixed lymphocyte reaction of T cells against B cells (AMLR) did not include LIF production in spite of the proliferative response. We would suggest that activated B cells present in the population of purified B cells are the stimulators in AMLR. In our interpretation these results support the hypothesis that AMLR reflects a mechanism by which T cells regulate lymphocyte function.

B-Lymphocytes↗
PubMed1978

Rapid identification of group A, B, C and G beta-haemolytic Streptococci by a modification of the co-agglutination technique. Comparison of results obtained by co-agglutination, fluorescent antibody test, counterimmunoelectrophoresis, and precipitin technique.

A rapid modification of the co-agglutination (COA) technique for grouping A, B, C and G beta-haemolytic streptococci was developed. The results are obtained within three hours after inoculation from primary plates of 0.5 ml broth. This method was compared to the fluorescent antibody test (FA) and counterimmunoelectrophoresis (CIE), two other rapid methods available for serological grouping of streptococci. Of 71 recently isolated streptococcal strains from clinical sources, 70 were correctly grouped in COA, 63 in FA and 68 in CIE. With commercial reagents COA compared favourably in accuracy to the other methods and can be recommended for routine serological grouping of beta-haemolytic streptococci in the clinical laboratory.

Agglutination Tests↗
PubMed1978

Spontaneous lymphokine production by human B lymphocytes.

When human blood lymphocytes are cultured in vitro without any intended stimulus, they produce activities in the supernatant resembling lymphokine. This phenomenon was further investigated in the present study, where it has been demonstrated by physicochemical characterization and inhibition experiments that leukocyte migration inhibitory activity in the supernatants is due to leukocyte inhibitory factor (LIF). When T and B lymphocytes were purified by carbonyl iron and SRBC-rosette sedimentation, only B cells produced LIF and leukocyte chemotactic lymphokine(s) in subsequent cultures. B cells elaborated lymphokines without the help of T cells. the need for co-operation of monocytes was also unlikely. T cells were inactive even when reconstituted with monocytes and platelets.

B-Lymphocytes↗
PubMed1978

Leukocyte chemotactic activity in cultures of unstimulated human lymphocytes.

We have shown earlier that unstimulated human lymphocytes in in vitro cultures produce migration inhibitory factor into the supernatant. The evidence of spontaneous lymphokine synthesis is strengthened further by this study, which demonstrates leukocyte chemotactic activity in these culture supernatants. The factor has a molecular weight of more than 5000 daltons, it resisted heating for 15 min at 100 degrees C, and showed maximum activity at dilution 1:4-1:8 of the supernatants.

Cells, Cultured↗
PubMed1978

Bacteria induce lymphokine synthesis polyclonally in human B lymphocytes.

We have studied the ability of various bacteria to stimulate human lymphocytes to produce leukocyte migration inhibitory factor (LIF). Mononuclear cells from adult and cord blood as well as purified T and B lymphocytes were stimulated with killed bacteria. The culture supernatants were tested for the presence of LIF by the agarose migration method. All nine bacterial strains tested activated unseparated mononuclear cells and B lymphocytes but not T cells to produce LIF. LIF was also present in cord blood cell cultures suggesting that the stimulation of lymphocytes was polyclonal rather than antigenic. Therefore, we propose that one of the physiologic functions of B lymphocyte lymphokines might be to form part of the nonspecific defense mechanisms against microbial invasion.

B-Lymphocytes↗
PubMed1977

Failure to obtain positive MEM tests in either cell-mediated immune conditions in the guinea-pig or in human cancer.

The macrophage electrophoretic mobility test described by Caspary and Field (1971) and modified by Pritchard et al. (1973) was investigated in various models of cell-mediated immune conditions in the guinea-pig and in cancer in man. No positive results were obtained in 92 guinea-pig experiments. Only 17 of 154 experiments on 74 patients gave definite positives in experiments with human cancer and a few positive results were obtained with normal healthy subjects.

Animals↗
PubMed1977

Leucocyte migration inhibitory activity in supernatants of cultured human mono-nuclear cells stimulated with mitogens or C3- and Fc-receptor reactions.

We studied whether reactions at the lymphocyte membrane receptors for complement, immunoglobulin or mitogens would induce lymphokine production. Human peripheral blood mono-nuclear cells were stimulated by C3- or Fc-receptor reactions and with phytohaemagglutinin (PHA) or lipopolysaccharide (LPS) and cultured for 3 or 4 days. C3- and Fc-receptor reactions were brought about by rosette formation with red cells coated with human complement or antibody. Culture supernatants were assayed for migration inhibitory activity with human leucocytes by the leucocyte-migration-in-agarose test. On the average, no migration inhibitory activity could be detected in cultures stimulated by C3- or Fc-rosette formation, mean migration indices (MI) being 99-2 and 96-1, respectively. Of the mitogens, PHA induced distinct lymphokine synthesis (mean MI 60-2) while the mean MI with LPS varied from 97-9-69-8, depending on the mitogen preparation used and the conditions of culture. We conclude that PHA and LPS are able to activate human lymphocytes into elaboration of migration inhibitory factors whilst reactions at C3- or Fc-receptors fail to do so.

Binding Sites↗