Biomedical subjects

Eduardo Sada-Díaz

Publications and source records attributed to Eduardo Sada-Díaz.

3 recordsLinked to original sources

PubMed2006

Mycobacterium bovis BCG substrains confer different levels of protection against Mycobacterium tuberculosis infection in a BALB/c model of progressive pulmonary tuberculosis.

Mycobacterium bovis BCG is the only available vaccine against tuberculosis. Reasons for why diverse BCG substrains induce different levels of protection in clinical trials remain unclear. The aim of this study was to compare the effectiveness of 10 BCG substrains in a mouse model of pulmonary tuberculosis. BALB/c mice were subcutaneously vaccinated and 2 months later were challenged with Mycobacterium tuberculosis H37Rv by intratracheal injection. Two and 4 months after challenge, delayed-type hypersensitivity (DTH) response, lung tissue affected by pneumonia, CFU, T-cell counts, and cytokine expression (interleukin-2 [IL-2], IL-4, IL-10, and gamma interferon) were determined. A differential protective effect of the diverse BCG substrains was found. BCG Phipps led to the largest and most persistent reduction of CFU counts and of the area of pneumonia at 2 and 4 months after challenge. This protection was accompanied by reduced IL-10-producing T cells. Contemporary BCG substrains induce a wide range of protection in this animal model. These data can help in the selection of the best vaccine for human immunization and for the development of novel recombinant BCG-based vaccine.

Animals↗

PubMedDate not supplied

Response of IFN-gamma and IgG to ESAT-6 and 38 kDa recombinant proteins and their peptides from Mycobacterium tuberculosis in tuberculosis patients and asymptomatic household contacts may indicate possible early-stage infection in the latter.

BACKGROUND: The ESAT-6 antigen from Mycobacterium tuberculosis evokes a protective immune response in murine models and is widely recognized by tuberculosis patients (TB) and healthy household contacts (HHC). However, little is known about human immune response to this antigen in populations from areas of high endemicity. This study aimed to determine the capacity of T-cells from a group of TB patients and HHC for cell proliferation and production of cytokines type Th1 or Th2 (IL-4, IL-10, and IFN-gamma) and to identify total IgG reactivity to the recombinant protein rESAT-6 and five overlapping synthetic peptides as well as to r38 kDa and two peptides. METHODS: T-cells from nine TB patients and nine HHC were stimulated with rESAT-6 and five overlapping synthetic peptides, previously selected from a set of 21 peptides and each of 16 amino acids in length (P1, P4, P6, P8, and P20). Similar experiments were carried out with r38 kDa and two peptides of 20 amino acids in length (38G and 38K). Cytokines in supernatants and total IgG from serum were determined by ELISA. RESULTS: Stimulation index (SI) was highest in HHC to rESAT-6 and peptides P1, P8, and P20. Differences in response to 38 kDa and 38G peptide between TB patients and HHC were not demonstrated. Cytokines from T-cell cultures were tested with a resulting SI=3.0. IFN-gamma was produced predominantly in HHC to rESAT-6, P8, and P20, while in TB patients production of IL-10 was detected in relation to r38 kDa. IL-4 was detected in minimal amounts in both groups. IgG from TB patients was predominantly recognized in connection with rESAT-6 and the P4 peptide, with an important response against r38 kDa detected in HHC. CONCLUSIONS: ESAT-6 recognition by HHC could indicate that these responses represent possible early-stage infections.

Adult↗

PubMedDate not supplied

[Tuberculosis: a current problem].

Tuberculosis is a public health problem. If the current trends continue, is expected to arrive to 10.2 million of new cases in 2005. There are three studies accomplished in 1995 in Mexican patients. The results show important difficulty in the application and the follow-up of the program of control of the tuberculosis, what has caused accumulation of chronic cases, moderate rate of primary resistance and alarming levels of primary and secondary multiresistance (23%). Mechanism of protective immunity against mycobacterium tuberculosis (MTB) in humans have not been clarified. Different subpopulations of lymphocytes CD4, CD8 and other populations as well as macrophages, and monocytes, have an important role. In industrialized countries, the managing of the MDRTB is based on the use of individualized treatments with second line drugs according to susceptibility test, however the foregoing has not been possible to apply it middle or low income countries. WHO has launches the initiative "DOTS plus" that consist in the administration of a standarized regimen on the basis of epidemiology of resistance in the country or region.

Drug Resistance, Microbial↗