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Biomedical subjects

I Joó

Publications and source records attributed to I Joó.

At least 19 recordsLinked to original sources
PubMed1992

Effects of melatonin and light on porphyrin synthesis in the bovine retina, pigment epithelium and choroid.

The quantity of porphyrin synthesized in the presence of 10(-3) M delta-aminolevulinic acid (ALA) is several times higher in the bovine pigment epithelium than in the retina. Synthesis in the retina was found to be increased by illumination, whereas synthesis in the pigment epithelium was decreased if the whole anatomical unit (retina-pigment epithelium-choroid) was cultivated together. The quantity of porphyrin synthesized in the presence of 10(-3) M ALA or 10(-6) M melatonin was different when the pigment epithelium and retina were separated. The combination 10(-3) M ALA with 10(-6) M melatonin inhibited retinal porphyrin synthesis after green light adaptation, while in the pigment epithelium green light adaptation induced porphyrin synthesis. It is postulated that the light-sensitive porphyrin-haeme synthesis of the retina-pigment epithelium-choroid functional unit may serve and modulate the synthesis of guanylate cyclase for cGMP.

Adaptation, Physiological↗
PubMed1992

Association between total cholesterol and plasma thromboxane B2 in human adults.

Apparently healthy adults were examined for their lipid and thromboxane parameters. The correlation between the levels of total cholesterol in serum and thromboxane B2/TXB2/ in plasma was strong mainly in men (p less than 0.01). However, the association between atherogenic index /AI/ and TXB2 levels tended to be higher in women. The authors suggest that, in healthy adults, elevated cholesterol levels coexist with abnormalities in thromboxane metabolism.

Adult↗
PubMed1991

Epidemiology of pertussis in Hungary.

Reliable data in Hungary on the incidence of pertussis have been available since the introduction in 1931 of obligatory notification. Immunization against pertussis was introduced compulsorily in 1953 with a combined diphtheria-tetanus-pertussis vaccine. Since that time the method of preparation, quality and quantity of the vaccine as well as its immunization schedule underwent several important modifications. As a result of vaccination the incidence of pertussis dropped from 56.967 cases (594.4 per 100,000 inhabitants) in 1953 to 16 cases (0.2 per 100,000 inhabitants) in 1989.

Child↗
PubMed1990

Nonspecific resistance-enhancing activity of zymosan in experimental bacterial infections.

The nonspecific resistance-enhancing activity of zymosan on experimental bacterial (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Serratia marcescens and Staphylococcus aureus) infections was investigated. Zymosan, being of very low toxicity, significantly enhanced nonspecific resistance to the above bacteria. The enhancement was the most pronounced 2 to 5 days after zymosan treatment.

Adjuvants, Immunologic↗
PubMed1988

Adjuvant effect of DEAE-dextran on cholera vaccines.

Investigations into the effectiveness of DEAE-dextran as an adjuvant of whole cell cholera vaccines (Vibrio cholerae Inaba and Ogawa serotypes) were conducted using two methods: (a) the active mouse protection test, (b) the determination of antibody production in the sera of immunized mice by measuring the level of vibriocidal antibodies, and by an enzyme-linked immunosorbent assay (ELISA). In all tests, the DEAE-dextran-adjuvanted vaccine showed an antigenicity substantially superior to that achieved without adjuvants.

Adjuvants, Immunologic↗
PubMed1986

Changes of serum lipids and lipoproteins during haemodialysis treatment in dialysed chronic uraemic patients.

Changes of serum lipids and lipoproteins were determined quantitatively before and after haemodialysis in chronic uraemic patients. Serum beta-lipoprotein significantly decreased due to haemodialysis, while alpha-lipoprotein and the FFA level significantly increased. Slight correlations were observed between the applied transmembrane pressure and the serum concentration of FFA, HDL-cholesterol or total cholesterol levels. Hyper-beta-lipoproteinemia was found in 70.9 per cent and Frederickson-HLP in 33.3% of the haemodialyzed chronic uraemic patients.

Adult↗
PubMed1986

Comparative testing of the potency of different PPD preparations.

The potency of different PPD preparations, obtained from M. tuberculosis and M. bovis was investigated in the guinea-pig test. The groups of animals were immunized with dried mycobacterium powder (obtained from M. tuberculosis, M. bovis and M. tuberculosis + M. bovis), suspended in sterile liquid paraffin oil and with BCG vaccine. The potency tests were carried out according to the WHO requirements. Independently of the immunization method, a significantly greater potency of homologous versus heterologous PPD could not be demonstrated. The mixed PPD preparation (obtained from M. tuberculosis + M. bovis) was fractionated on SEPHAROSE 6 B and SEPHACRYL S 200 column. The potency of different fractions compared to the non-fractionated material was determined in the guinea-pig tests. The animals were immunized by dried mycobacterium powder (obtained from M. tuberculosis + M. bovis), suspended in sterile liquid paraffin oil. The IU content of fractions was calculated according to their protein N content, compared to the non-fractionated material. In these experimental conditions PPD fractions with significantly greater potency than the non-fractionated material could not be found. As a final conclusion we suggest that the desired improvement of tuberculosis diagnostics can be achieved not only by using PPDs derived from different mycobacteria but by further immunochemical purification of the tuberculin preparations and extensive testing of the purified materials in human beings as well.

Animals↗
PubMed1984

Synergistic interaction of baker's yeast and iron in the enhancement of bacterial virulence.

The virulence-enhancing interaction of baker's yeast and different iron preparations (ferric ammonium citrate and iron dextran) was tested in mice challenged with Salmonella typhi and Vibrio cholerae (Inaba and Ogawa) strains. The virulence-enhancing effect of the yeast + iron combination increased significantly as compared to that of either yeast or iron alone. Toxicity assays of the single and combined baker's yeast and iron preparations by the mouse weight gain test have shown that the combinations are considerably more toxic than either single agent, probably owing to the presence of yeast. Examination of the single and combined preparations for influence on body temperature of mice has revealed a general hypothermic action, which was strongest in the combinations, owing again to the yeast. Theoretical considerations on the underlying mechanism of the virulence-enhancing effect have supported the hypothesis that the effect might be associated with the strong hypothermic action produced by baker's yeast and baker's yeast + iron combinations, in as much as hypothermia increases the production of siderophores which ensure the acquisition of iron indispensable for bacterial growth.

Animals↗
PubMed1982

[Cell-free Pseudomonas vaccine. IV. Laboratory trials of the effectiveness of experimental Pseudomonas vaccines].

Partially purified water-soluble cellular protein antigens have been obtained from 2 newly isolated P. aeruginosa strains and 1 museum P. aeruginosa strain, belonging to immunotypes 2, 3 and 7, by the method of preparative ultracentrifugation. Such trivalent P. aeruginosa vaccine (PV) has proved to be effective in direct and cross experiments of the active protection of mice. The method of ultrafiltration has been used to prepare monovalent PV from a newly isolated strain belonging to immunotype 3/7. This monovalent PV has been found to stimulate immunity to infection with homologous or heterologous P. aeruginosa strains in mice. The comparison of the results obtained in the study of PV prepared by the methods of ultracentrifugation and ultrafiltration suggests that both these methods for the isolation and purification of P. aeruginosa protective protein antigens are equally effective.

Animals↗
PubMed1982

Vaccines against Pseudomonas aeruginosa results and perspectives of investigations (survey).

At the present time, there are many preparations for active immunization against P. aeruginosa infection (pseudomonas infection), but none of the proposed preparations has so far been widely used in medical practice. Development of P. aeruginosa vaccine (PV) should obviously be based on findings concerning the pathogenesis of infection, the mechanisms of immunogenesis and the factors of virulence of the causative agent. On the basis of results of their studies the authors believe that PV should include a non-toxic low-molecular component (or components) of the extracellular slime and water-soluble protein antigens of the cell wall, isolated from one or three selected strains of P. aeruginosa. Adoption of these components onto aluminium hydroxide can obviously increase the efficiency of PV.

Animals↗
PubMed1982

Active and passive mouse-protecting capacity of Pseudomonas aeruginosa protein vaccines.

Six different vaccines were prepared, each containing the soluble, practically lipopolysaccharide-free protein extract of 2 or 3 Pseudomonas aeruginosa strains. In active mouse protection tests the vaccines were shown to give protection against both homologous and heterologous serotype strains, and against strain PA-103 producing exotoxin A. In rabbits the vaccines were found to stimulate the production of protective antibodies demonstrable in a passive mouse protection test. The immune serum had a protective effect against the exotoxin A-producing strain PA-103, too. Toxicity of the vaccines was studied in mice (mouse weight gain test) and in rabbits (intracutaneous skin test and pyrogenicity). The vaccines were not or only slightly toxic.

Animals↗