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Biomedical subjects

R Cabrera-Contreras

Publications and source records attributed to R Cabrera-Contreras.

6 recordsLinked to original sources
PubMed1990

[Phagocytic capacity of peritoneal exudate cells from rats immunized with a ribosomal preparation of Ty2 Salmonella typhi].

It was compared the activity of exudate peritoneal cells (EPC) obtained from CFW mice immunized either with Salmonella typhi Ty2 ribosomal fraction or whole-cell heat inactivated vaccine, both in comparison with EPC from sham-immunized. In the group which received ribosomal preparation, a subcutaneous dose equivalent to 100 micrograms of RNA in incomplete Freund's adjuvant (IFA) was initially used and 14 days after a booster of the same dose in IFA was given. A single dose of whole-cell heat inactivated vaccine, with 10(6) bacteria in IFA was employed subcutaneously in animals of the second group. EPC from controls and immunized mice were withdrawn at periods of 7, 11, 14, 18, 22, 25, 29 and 31 days after immunization and each sample was incubated in vitro in presence of live virulent non-opsonized S. typhi Ty2 in 1:200 cell-bacteria relation. Twenty four hours after cultivation, EPC bacterial capacity was determined after cell disruption and enumeration of survival bacteria were made through viable counts. Results have shown that EPC from mice immunized were more efficient in eliminating intracellular bacteria than those which came from sham-immunized animals. Also, it was found that EPC from mice immunized with ribosomal preparation were more efficient (maximum P = 0.005) than EPC from the mice which received killed whole bacteria.

Animals↗
PubMed1985

Enhancement of immunogenic activity of ribosomal preparations from Haemophilus influenzae by various adjuvants.

Ribosomes from Haemophilus influenzae type b have been reported to have immunoprotective activity in animals that can be enhanced by adjuvants. In this report we evaluated the adjuvant activity of several compounds in conjunction with ribosomes from the b and c serotypes of H. influenzae. Alhydrogel, saponin, and DPT were found to significantly enhance the immunoprotective response in mice, equalling or exceeding the activity of Freund's incomplete adjuvant. All of these adjuvants also enhanced significantly the IgM response of mice to sheep red blood cells. Ribosomes were also found to enhance this response. Among the compounds failing to provide adjuvant activity for ribosomes were poly(A:U), muramyl dipeptide, mycobacterial extract, dimethylglycine, methylated bovine serum albumin, sodium diethylthiocarbamate, and cetyltrimethylammonium bromide.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Vaccines against Haemophilus influenzae B: present, past and future].

Haemophilus influenzae type b (Hinb) is the main etiologic agent of severe pediatric illnesses, such as meningitis, epiglottitis and pneumonia. Countries most affected by this pathogen are localized in the American, European and African continents. While this organism was originally isolated 100 years ago, the first field trial using a whole killed vaccine was performed until 1959. Since then, further controlled clinical trials have mainly been conducted in the North American and European continents. Under appropriate safety and efficacy evaluation tests performed by the Federal Drug Administration Agency (FDA), five vaccines were licensed: one single and four conjugated preparations. Worldwide and regional epidemiologic data concerning serious diseases produced by this organism have shown their outstanding impact in the public health of developed countries. Unfortunately, in developing countries similar epidemiological indexes are lacking for lethal and disabling diseases, such as meningitis. In order to decrease high morbidity and mortality rates of this meningeal disease and its neurological sequelae, immunoprophylactic preventive measures have been recommended. Furthermore, some risk factors of this infant illness can also be reduced. New strategies regarding conjugate Hib-vaccines are reviewed. Finally, promising virulence factors or self Hib-structures for the production of vaccines are suggested, such as outer membrane proteins (OMP), lipooligosaccharides, fimbriae or pili.

Bacterial Vaccines↗
PubMedDate not supplied

[Haemophilus influenzae b: a review on the determinants of pathogenicity and immune response to the infection].

Haemophilus influenzae is still one of the main causes of diverse invasive diseases in children in México. Epidemiologic data indicate that these processes affect primarily the central nervous system and the respiratory tract. Several factors are involved in the expression of infectious disease by this organism, among them the pathogenic determinants of the parasite and those related with resistance in the host. Occurrence of disease is usually the result of the interaction between these determinants. Knowledge of these pathogenic determinants of the parasite and of factors involved in the immune response of the host have allowed an understanding of the infectious process and have directed research in a least three areas: 1) identification of bacterial membrane fractions related with diagnosis of the disease, 2) screening for immunogenic components in the bacterias as vaccine candidates to be used in the prevention of the disease and, 3) the planning of appropriate alternatives for specific antimicrobial therapy.

Bacterial Vaccines↗
PubMedDate not supplied

[Perspectives on basic biotechnology research in Mexico].

The main fields of basic research in biotechnology in Mexico are reviewed, with emphasis in the problems relevant to public health, such as environmental pollution and vaccine development and production. The institutions that are responsible for these studies are analyzed in terms of their relative participation.

Academies and Institutes↗