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Biomedical subjects

J Kumate

Publications and source records attributed to J Kumate.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Vaccination against measles. The situation in Mexico and America. Advances in the method of aerosol immunization].

We present general comments on the epidemiology of measles considering the pre-vaccine era as well as the post-vaccine period in which some changes can be observed: the decrease in morbidity and mortality, the extension of the inter-epidemic interval, the increase in the mean age of infection, etc. We make some estimations about the vaccine coverage and the ideal age of immunization for the goal of eradication (assuming a lifelong immunity for the vaccinees). The technical problems in measles immunization are also revised explaining why no continental country has been able to eliminate the disease. We describe the epidemiological situation in North America, Mexico and Latin American countries. Lastly we present the Mexican experience with the inhaled aerosolised vaccine: the studies in Monterrey (Sabin et al, 1982), other investigation in Mexico, D.F. and in the State of Jalisco, as well as the mass campaigns in Aguascalientes in 1988 and in Coahuila and Nuevo León in 1989. We propose it as an effective, harmless, simple, inexpensive and practical method.

Adolescent↗
PubMed1989

Immunoblot detection of class-specific humoral immune response to outer membrane proteins isolated from Salmonella typhi in humans with typhoid fever.

The studies reported here were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce a humoral immune response in humans with typhoid fever. OMPs were isolated with the nonionic detergent Triton X-100 and were found to be contaminated with approximately 4% lipopolysaccharide. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns showed protein bands with molecular size ranges from 17 to 70 kilodaltons; the major groups of proteins were those that correspond to the porins and OmpA of gram-negative bacteria. Rabbit antiserum to OMPs or to S. typhi recognized OMPs after absorption with lipopolysaccharide. Sera from patients with typhoid fever contained immunoglobulin M antibodies which reacted with a protein of 28 kilodaltons and immunoglobulin G antibodies which reacted mainly with the porins, as determined by immunoblotting. These results indicate that the porins are the major immunogenic OMPs from S. typhi and that the immune response induced in the infection could be related to the protective status.

Adult↗
PubMed1989

[Serology of typhoid fever in children. I. Capillary flocculation- agglutination. Its specificity in an asymptomatic population and its utility at a pediatric emergency service].

Using a capillary flocculation technique we evaluated serum samples of asymptomatic children for typhoid fever serology. Thirty one (5.16%) of the 600 serum samples tested were positive for a specificity of 95%. To evaluate the sensitivity of the test, serum samples from 36 children with proven typhoid fever and a similar number of control patients were evaluated. The sensitivity of the capillary flocculation test in this group was 100%. The test compared favorably with the Ruiz Castañeda serologic test for typhoid fever.

Adolescent↗
PubMed1989

[Comparative serology in typhoid fever in children. II. Comparison of a microhemagglutination plate technic with Ruiz-Castañeda surface fixation].

Two lipopolysaccharide antigens that differ by the technique of preparation from S. typhi, one named crude is easily extracted, the other one is water-phenol extracted. Both were adsorbed by papain and cysteine to lamb erythrocyte surfaces, fixed then by glutaraldehyde and used in a plate microhemagglutination test (MHA). The MHA test was done with 30 sera from children with S. typhi blood isolates. The same number of control sera were tested for comparison. The crude LPS antigen showed better sensitivity: 73% versus 53% of the water-phenol extracted one despite a high index correlation (r = 0.88). The latest one was evaluated in a prospective study, using it during a six-month period in an emergency room with S. typhi blood isolated sera. The MHA test was compared with the surface fixation test. Both assays showed similar sensitivity and a specificity of 91 and 100%, respectively.

Adolescent↗
PubMed1988

Protection against Salmonella typhi infection in mice after immunization with outer membrane proteins isolated from Salmonella typhi 9,12,d, Vi.

The current studies were undertaken to assess the ability of the outer membrane proteins (OMPs) of Salmonella typhi to induce protection against challenge with the bacteria in mucin. OMPs were isolated as described by Schnaitman (J. Bacteriol. 108:553-556, 1971) and were found to be contaminated with approximately 4% lipopolysaccharide (LPS). Immunization with as little as 30 micrograms of OMPs conferred 100% protection to mice challenged with up to 1,000 50% lethal doses (LD50) of two strains of S. typhi (9,12,d, Vi and Ty2). In addition, 30% protection against challenge with up to 500 LD50 of Salmonella typhimurium was achieved. Immunization with LPS at doses equivalent to those found in the OMPs was considerably inferior to the OMPs in the induction of an immune status. Moreover, LPS was effective only when the challenge was performed with S. typhi 9,12,d, Vi (40% protection to 100 LD50). An antiserum raised in rabbits reacted mainly against the bands of the molecular weights corresponding to the so-called porins contained in the OMP preparation as shown by Western blotting (immunoblotting). This rabbit antiserum protected 100% of mice against challenge with 100 LD50 of either strain of S. typhi and 80% of mice against challenge with the same LD50 of S. typhimurium. These results indicate the usefulness of OMPs in the induction of active immunity against S. typhi in mice.

Animals↗
PubMed1983

Clearance and tissue distribution of intravenously injected Salmonella typhi polysaccharide in rabbits.

The interaction of Freeman polysaccharide of Salmonella typhi with blood and tissues of rabbits was studied by radioimmunoassay. After intravenous injection of 1.0 mg of S. typhi Freeman polysaccharide, a rapid clearance phase (t1/2, 6.0 min) was followed by a slower clearance period (t1/2, 55.2 min). These results suggest first, that the distribution of whole lipopolysaccharide is a function of how the polysaccharides are handled by the host; further, that the O side chain determines how and where lipopolysaccharide is cleared from the circulatory system; and finally, that Freeman polysaccharide regulates the toxicity of lipopolysaccharide by influencing its clearance from blood.

Animals↗