Presence of Seropositive Patients to Trypanosoma cruzi in a Municipality of the Mixtec Sierra of the State of Puebla: A Preliminary Study.

PURPOSE: The state of Puebla has the social marginalization and ecological conditions for the transmission of infectious agents to be effective. Until a few years ago, the state of Puebla was considered non-endemic to the presence of Trypanosoma cruzi as there are no official reports of chronic cases. The objective of this work was to carry out a preliminary study on the prevalence of anti-T. cruzi antibodies in rural areas of the Huatlatlauca municipality in the Mixtec sierra of the state of Puebla. METHODS: A total of 196 serum samples from 12 rural localities were tested by using four tests: two enzyme-linked immunosorbent assays, an xenodiagnoses and PCR assay. RESULTS: Overall, 28 (14.2%) of 196 samples were positive for T. cruzi by ≥ 2 tests (95% CI 6.6-20.8%). Our results suggested that the municipality of Huatlatlauca in the Mixteca Sierra of the state of Puebla is an area with endemic potential for the disease with a high prevalence rate in the adult population and with cases in newborns, these high transmission rates are probably associated with problems of congenital and vector transmission. CONCLUSION: Additional studies should be conducted to generate adequate campaigns for the control of Chagas disease in this area.

[Obtention of monoclonal antibodies against human secretory IgA]. / Obtención de anticuerpos monoclonales contra IgA secretora humana.

In order to determine the IgA levels in secretions, the authors engaged themselves to obtain monoclonal antibodies against this immunoglobulin and to show their possible utilization in the development of quantitation methods. 6 monoclonal antibodies were obtained: one against the secretory component (SC) and five against the heavy-chain (HC) of IgA. IgA purified from human colostrum was used as immunogen (HC). The immunoglobulin isotypes (IgG2a and IgG1) were determined in 2 monoclonal antibodies, one against SC and the other against HC. Polyacrylamide gel electrophoresis was performed in the presence of sodium dodecyl sulphate and b-mercapto-ethanol. Immunotransference was also carried out to determine their specificity. Secretory IgA was detected in saliva specimens. The anti-SC monoclonal antibody obtained in-the laboratory of the "Pedro Kourí" Institute of Tropical Medicine (IPK) was compared with a commercial one (Sigma Chemical Co.), and a similar behaviour was observed. The monoclonal antibody against SC (IPK) was used to detect IgA specific to LPS ogawa in persons vaccinated with an attenuated strain of Vibrio cholerae. Marked differences were found between the levels before and after immunization. The anti-HC monoclonal antibody was utilized to make an ELISA-like simulated system. The detection limit was 9.89 ng/mL.

Conjugation of 5-azido-3-oxapentyl glycosides with thiolated proteins through the use of thiophilic derivatives.

5-Azido-3-oxa-pentyl beta-D-galactopyranoside was prepared from diethylene glycol monochlorohydrin and used as a model of oligosaccharide hapten. After deprotection, a series of amides bearing thiophilic groups had been obtained through the terminal amino function and essayed in coupling reactions with thiolated BSA. Also several Lewis human blood group oligosaccharides had been conjugated with thiolated BSA demonstrating the usefulness of the methodology.

Involvement of calcium ions in the mode of action of disodium cromoglycate and ketotifen on smooth muscle.

The mechanism of inhibitory action of disodium cromoglycate (DSCG) and Ketotifen (Ke) on smooth muscle against various spasmogens remains uncertain. In an attempt to elucidate it, we have studied the effects of both drugs on cumulative dose response curves (CDRC) to CaCl2 in guinea pig ileum. We found that they induce a shift to the right and a non surmountable depression of the maximal response of these CDRC which suggests non competitive antagonism. Furthermore, DSCG inhibits 45Ca++ uptake by guinea pig ileum after acetylcholine stimulation which constitutes strong evidence that inhibition of calcium ion utilization by smooth muscle cells plays a major role in the mode of action of DSCG.