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Biomedical subjects

J Kumate

Publications and source records attributed to J Kumate.

At least 19 recordsLinked to original sources
PubMed1997

Infectious diseases in the 21st century.

Infecto-contagious diseases in the twenty-first century with respect to precedent will see themselves deprived of smallpox, dracunculiasis and very probably of paralyzing poliomyelitis. Vaccination-preventable diseases, such as measles, whooping cough, diphtheria, tetanus, rabies, some forms of meningitis, yellow fever and episodes of disseminated tuberculosis will greatly diminish in their rates of morbi-lethality; the elimination of some, and the eradication of measles, are expected. Other diseases such as diarrhea (including cholera), geo-helminthiasis, some severe respiratory tract infections and the majority of vector-transmitted infectious diseases will decrease due to improvements in potable water services, drainage, sanitary food control, living quarters, and individual and community anti-vector action. Leprosy, onchocerciasis and several parasitoses will be controlled by the available antimicrobial drugs. Infectious diseases will continue to be an important health problem due to: Reduction in the immunocompetence resulting from the aging of the population, chemotherapies necessary for neoplasms, and autoimmune pathology and the survival of persons with primary immunodeficiencies; lifestyles prone to infectious pathology, such as mega-city urbanization, children in day care centers, industrialized foods, intravenous drug addiction, sexual liberation, global commerce, and tourism; antibiotic-multiresistant microbial flora; environmental disturbances as a result of global warming, deforestation, the settling of virgin areas, dams, the large-scale use of pesticides, fertilizers and antimicrobials, and natural/social disasters generators of poverty, violence and deprivation will result in emergence or re-emergence of infectious diseases already controlled in the past.

Communicable Disease Control↗
PubMed1996

Impact of oral rehydration and selected public health interventions on reduction of mortality from childhood diarrhoeal diseases in Mexico.

Reported are the results of an analysis of mortality trends from diarrhoeal diseases among under-5-year-olds in Mexico between 1978 and 1993 in relation to the impact of education, basic sanitation, and selected medical care practices. The study period was divided into three stages; the first pre-dated the widespread application of oral rehydration therapy (ORT); the second, covered the implementation of a nationwide programme promoting ORT; and the third included additional measures, such as immunization and improvements in basic sanitation. Mortality rates decreased progressively, at an average of 1.8% per year in the first stage, 6.4% in the second, and 17.8% in the third. The importance of literacy campaigns for women and the promotion of ORT was confirmed. Both of these measures reduced mortality; however, a greater reduction resulted from a massive immunization campaign against measles and improvements in sanitation (expansion of the drainage and piped water systems, improved water chlorination procedure, and effective prohibition of the use of sanitary sewage for vegetable irrigation).

Adult↗
PubMed1993

Lymphocytic proliferative response to outer-membrane proteins isolated from Salmonella.

Porins isolated from Salmonella typhi have been demonstrated to protect against the challenge with this bacteria in mice. The mechanism has not been clarified, but could be associated with activation of both humoral and cellular immunity. In order to evaluate the induction of specific T cell responses, the lymphocytic proliferation to porins isolated from Salmonella typhimurium, Salmonella typhi and Escherichia coli was examined by 3H-thymidine incorporation assay in mice immunized with three different antigens: acetone-killed S. typhimurium, its porins, or outer-membrane proteins (OMPs) isolated from S. typhi. Higher proliferative responses were observed in mice immunized with porins and OMPs compared with those which received the acetone-killed bacteria. Although cross-reactivity was observed between porins, they were not mitogenic. Moreover, porins were able to activate T lymphocytes isolated from mice immunized with S. typhi OMPs. These results suggest that T cell activation, through the release of lymphokines, may play a role in the induction of protective immunity with porins.

Animals↗
PubMed1993

Human cell mediated immunity to porins from Salmonella typhi.

The current studies were undertaken to assess the role of the porins and outer membrane proteins (OMP) in the human immune response to Salmonella typhi 9, 12 Vi:d. Experiments were performed to determinate the lymphocyte activation response to porins in individuals who had been vaccinated against typhoid fever. 10 healthy volunteers were studied before and 10 days after oral or subcutaneous immunisation. Five patients with typhoid fever were also studied. Lymphocyte activation was measured by the 3H thymidine incorporation assay. Individuals with typhoid fever as well as those immunised with oral vaccine responded well to porins and outer membrane proteins, as opposed to those immunised with the subcutaneous vaccine. These results suggest that the porins and OMP play a role in the cellular immune response against Salmonella typhi.

Administration, Oral↗
PubMed1992

Active protection of mice against Salmonella typhi by immunization with strain-specific porins.

NIH mice were immunized with between 2.5 and 30 micrograms of two highly purified porins, 34 kDa and 36 kDa, isolated from the virulent strain Salmonella typhi 9,12, Vi:d. Of mice immunized with 10 micrograms of porins, 90% were protected against a challenge with up to 500 LD50 (50% lethal doses) of S. typhi 9,12,Vi:d and only 30% protection was observed in mice immunized with the same dose of porins but challenged with the heterologous strain Salmonella typhimurium. These results demonstrate the utility of porins for the induction of a protective status against S. typhi in mice.

Animals↗
PubMed1990

Non-pathogenic Entamoeba histolytica: functional and biochemical characterization of a monoxenic strain.

We have cultured under monoxenic conditions and characterized an Entamoeba histolytica clone, MAV-I CINVESTAV (MAV-I), obtained from feces from an asymptomatic carrier. The clone shows the non-pathogenic E. histolytica zymodeme type I, which did not change through the process of monoxenization. Clone MAV-I was non-pathogenic in both in vivo and in vitro tests, and it did not have a functional 112-kDa adhesin. As far as we know, this is the first non-pathogenic monoxenic strain reported. Clone A (strain HM1:IMSS), a highly virulent clone with pathogenic zymodeme type II, and which has the 112-kDa adhesin, was used as a control. Protein patterns from both clones were almost identical in one-dimensional gels. In two-dimensional gels, differences in high-molecular-weight proteins were detected. Clone MAV-I adhered and phagocytosed only 12% of the red blood cells adhered and phagocytosed by clone A. MAV-I trophozoites did not destroy cell culture monolayers and did not produce hepatic abscesses in hamsters. They also showed deficiency in protease activity. The absence of virulence in clone MAV-I correlated directly with the absence of a functional 112-kDa adhesion, supporting the role that this protein plays in virulence.

Animals↗
PubMed1990

[Obtaining monoclonal antibodies against outer membrane glycoproteins of Entamoeba histolytica].

The goal of this paper was the production of monoclonal antibodies capable of detecting relevant antigens from the surface of Entamoeba histolytica trophozoites, with the purpose of using them as a diagnostic test. The cellular fusion for obtaining the monoclonal antibodies (mAb) was done with spleen cells from BALB/c mice, previously immunized with glycoproteins from the membrane, as well as Sp2/0 cells. The hybridoma supernatants were tested with ELISA, using glycoproteins and lipopeptide phosphoglycans (LPPG) as antigens. Seven hybridomas producing mAb against the glycoproteins were found. Among these, three recognize LPPG. The ability of reacting with the mAb against two molecules disappeared for all the LPPG positive ones when were treated with meta-periodate, and only three reacted against the glycoproteins. All of the mAb were of the Ig M isotypes. They were characterized by Dot blot and Western blot assays. From the results, one may deduce that some mAb recognize as epitopes the polysaccharide portion, and thus infer that they are directed of against the surface and therefore, in the future, could be used with a diagnostic purpose.

Animals↗
PubMed1990

[Seroepidemiology of amebiasis in the northern region of the Republic of Mexico].

The object of paper has been the study of amebic seroepidemiology in the northern region of Mexico, by means of an immunoenzymatic assay in solid phase (ELISA). The proteic antigen was obtained from axenic culture of E. histolytica's trophozoites of strain HM1:IMSS, by means of solubilization with phenoxy polyethoxyethanol (Triton X-100). Standardization of the method was obtained by analysis of 80 sera from patients with both a clinical and radiologic diagnosis of amebic hepatic abscess and 80 sera from healthy patients. The sensitivity reached 95% and the specificity was 90.7%. 15,457 sera from eight Mexican northern states were tested as part of the National Seroepidemiologic Survey. A semiautomatic BIOMEK 1,000 (Beckman Ins.) equipment was used. The positive ratio varied between 2.0% in Southern Baja California and 4.92% in Chihuahua, with an average ratio for the whole group of 3.34%. The first three places, in descending order, are Chihuahua (4.92%), Sinaloa (4.01%) and Northern Baja California (3.78%). The positive man: woman ratio was 0.87:1 and fluctuated between 0.38:1 in Coahuila and 1.76:1 in Nuevo Leon. In the whole sample the positive ratio of men was 3.00% and in women was 3.43%. The antibody profile related to age, is similar to diseases reported to be highly endemic; the percentage of positive sera rose progressively up to the age of 20 years (4.05%), at which a plateau occurred with a slight descending tendency up to 60 years of age (3.54%), after which a clear descent in the positive index is seen. No important variations were observed when comparing groups of ages and sexes. The antibody level seems to show an inverse relationship with the incidence rate of amebiasis.

Adolescent↗
PubMed1990

[Immunochemical differences in the surface polysaccharides obtained from Entamoeba histolytica strain HM1:IMSS and its virulent (C-A) and non-virulent (L-6) clones].

There probably exist many different surface molecular polysaccharides with different compositions of their constituent sugars, in the different zymodemes. This fact might have a repercussion upon the resistance to the lysis of the complement. Seeking to prove this hypothesis, the ideal would be to obtain polysaccharide molecules of type LPFG of pathogenic and non-pathogenic zymodemes, demonstrating that there is a difference in the chemical composition of their polysaccharides. If this were true, a serologic classification, of the different zymodemes, would be possible in a fashion similar to gram-negative bacteria. Our results suggest the existence of structural differences between the polysaccharides of a virulent clone (C-A) and a non-virulent one (L-6).

Animals↗
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↗