A role for preadipocytes as macrophage-like cells.

Several lines of evidence have supported a link betweeen adipose tissue and immunocompetent cells. This link is illustrated in obesity, where excess adiposity and impaired immune function have been described in both humans and genetically obese rodents. In addition, numerous factors involved in inflammatory response are secreted by both preadipocytes and macrophages.

Binding of anti-CD23 monoclonal antibody to the leucine zipper motif of FcepsilonRII/CD23 on B cell membrane promotes its proteolytic cleavage. Evidence for an effect on the oligomer/monomer equilibrium.

In the present study we have compared the binding of two monoclonal antibodies to CD23, EBVCS1 and mAb25, which recognize the stalk and the lectin domain, respectively, on the CD23 molecule. At 4 degreesC, EBVCS1 binds to about 10% of the receptors recognized by mAb25 on the B cell surface. At 37 degreesC, whereas mAb25 reaches its maximal binding within a few seconds, EBVCS1 requires 60 min to bind to the same extent.

A community-based seroepidemiologic study of Helicobacter pylori infection in Mexico.

A nationwide community-based survey for Helicobacter pylori infection had not been done. This study sought to determine the seroprevalence of infection in Mexico, and the socioeconomic and demographic variables that are risk factors for infection. The survey assessed 11,605 sera from a sample population representing persons ages 1-90 years from all socioeconomic and demographic levels and from all regions of Mexico.

Infection with CagA+ Helicobacter pylori strains as a possible predictor of risk in the development of gastric adenocarcinoma in Mexico.

Helicobacter pylori strains possessing the Cag pathogenicity island have been associated with increased gastric inflammation and with duodenal ulcer. In contrast, studies on the association of cagA+ H. pylori infections and gastric cancer have shown conflicting results.

Validation of a serologic test for the diagnosis of Helicobacter pylori infection and the immune response to urease and CagA in children.

Objective: Little is known about Helicobacter pylori infections and the immune response to urease and CagA in pediatric populations. Our aims were: 1) to validate serological assays for antibodies against whole cell extract, CagA, and urease of H. pylori; 2) to examine their role in diagnosis of infection in children with recurrent abdominal pain (RAP); and 3) to examine the antibody responses to CagA and urease in children.

Antigenic and genomic diversity of human rotavirus VP4 in two consecutive epidemic seasons in Mexico.

In the present investigation we characterized the antigenic diversity of the VP4 and VP7 proteins in 309 and 261 human rotavirus strains isolated during two consecutive epidemic seasons, respectively, in three different regions of Mexico. G3 was found to be the prevalent VP7 serotype during the first year, being superseded by serotype G1 strains during the second season. To antigenically characterize the VP4 protein of the strains isolated, we used five neutralizing monoclonal antibodies (MAbs) which showed specificity for VP4 serotypes P1A, P1B, and P2 in earlier studies.

Serotype specificity of the neutralizing-antibody response induced by the individual surface proteins of rotavirus in natural infections of young children.

The relative contribution of the rotavirus surface proteins, VP4 and VP7, to the induction of homotypic as well as heterotypic neutralizing antibodies (NtAbs) in natural infections was studied. The NtAb titers of paired sera from 70 infants with serologically defined primary rotavirus infections were determined with a panel of rotavirus reassortants having one surface protein from a human rotavirus (serotypes G1 to G4 for VP7 and P1A and P1B for VP4) and the other surface protein from a heterologous animal rotavirus strain. A subset of 37 children were evaluated for epitope-specific antibodies to the two proteins by an epitope-blocking assay.

Effects of toxin A from Clostridium difficile on mast cell activation and survival.

Toxins A and B from Clostridium difficile are the main cause of antibiotic-associated diarrhea and pseudomembranous colitis. They cause fluid accumulation, necrosis, and a strong inflammatory response when inoculated in intestinal loops. Since mast cells are a rich source of inflammatory mediators, abundant in the gut, and known to be involved in C.

Antibiotic noncompliance and waste in upper respiratory infections and acute diarrhea.

A prospective cohort study was conducted to analyze factors associated with antibiotic noncompliance and waste among patients suffering acute respiratory infection (ARI) and acute diarrhea (AD). The study took place in four primary health care clinics in Mexico City, two belonging to the Ministry of Health (MoH) and two to the Mexican Social Security Institute (IMSS). Two hundred twenty-two patients with ARI and 155 with AD were included.

Prospective study of Entamoeba dispar infection in a cohort of mothers and their infants: relationship to serum antibody response.

The sera of cohorts of newborn infants and their mothers, characterized as cyst passers of Entamoeba with nonpathogenic zymodemes (E. dispar) and seropositive for amoebic antigens, were analyzed. Both cohorts were followed for a period of 12 months by microscopic examination of feces and determination of serum anti-amoebic antibody titers using the indirect hemagglutination assay.

Comparison of the response to the recombinant vaccine against hepatitis B virus in dialyzed and nondialyzed children with CRF using different doses and routes of administration.

In patients with chronic renal failure (CRF), parenteral transmission of the hepatitis B virus (HBV) is common. The response to the recombinant vaccine is 50%-80% of seroprotection. Therefore, to improve seroprotection, different strategies such as dose augmentation, vaccination at the predialysis stage, subcutaneous application, and using interleukin were tried, with unsatisfactory results.

[Comparison of 2 dyes in the detection of Pneumocystis carinii].

Objective: To evaluate two staining procedures used in the detection of P. carinii.

Material And Methods: Bronchoalveolar lavage samples were obtained from 20 immunosupressed rats.

Comparison of five methods for the detection of measles specific immunoglobulin G antibody.

In this work we compare the sensitivity, specificity and predictive values of hemagglutination inhibition (HI), immunofluorescent assay (IFA), biotin-streptavidin immunofluorescent assay (B/SA-IFA), enzyme-linked immunosorbent assay (EIA) and plaque neutralization test (PN). This study includes serum samples from children taken before and after vaccination, children with clinically diagnosed measles and household contacts. EIA were the most specific and better serological diagnostic test.

Improving physician prescribing patterns to treat rhinopharyngitis. Intervention strategies in two health systems of Mexico.

To improve prescribing practices for rhinopharyngitis, an interactive educational intervention and a managerial intervention were carried out in 18 primary care facilities in metropolitan Mexico City. Four family medicine clinics of the Mexican Social Security Institute (IMSS) and 14 health centres of the Ministry of Health (SSA) were included. A quasi-experimental design was employed.

Antifertility effects of (+)-S-2-amino-6-iodoacetamidohexanoic acid (2-AIHA) in female rats.

(+)-S-2-amino-6-iodoacetamidohexanoic acid (AIHA), an irreversible inhibitor of the ornithindecarboxylase and extrahepatic arginase enzymatic activities with antineoplasic properties, was evaluated for antifertility activity in pregnant rats by oral administration at different periods of gestation. Our results showed that doses of 10 and 20 mg/kg of AIHA orally administered produced a contraceptive effect when it was administered from days 2 to 5, and 8 to 12 of gestation, respectively. The gestation time was slightly shortened when AIHA was applied from day 15 until labor.

Indirect immunofluorescent assay (IFA) in buffy coat as a rapid diagnostic test for invasive candidiasis.

In order to have a diagnostic test for invasive candidiasis, an immunofluorescent assay (IFA) in buffy coat was developed and evaluated. This test was compared to buffy coat culture and blood culture. The study was divided into two parts: evaluation of the diagnostic test in a rabbit model, and for diagnosis in patients at high risk for invasive candidiasis.

From research to public health interventions. I. Impact of an educational strategy for physicians to improve treatment practices of common diseases.

Errors in treating common diseases occur very frequently in primary health care practice. While many of these mistakes are not life-threatening, the costs of abuse in drug prescription may be greatly increased. An educational strategy aimed to improve physicians' prescribing practices for acute diarrhea (AD) and acute respiratory infection (ARI) was developed as a research study, involving three medical care units.

Archives of Medical Research: an historical and subject coverage overview.

A bibliometric study about the subject content of the articles published in the Mexican scientific journal Archives of Medical Research is reported. The journal, published by the Mexican Institute of Social Security (IMSS), is comprised of 100 regular issues and 12 special supplements giving a total amount of 1,424 reports on medical research performed in Mexico during the last 25 years. According to the type of studies published during this period, we found that there is a similar percent of biomedical and clinical reports in the journal (47 and 42%, respectively) and a low proportion of epidemiological and medical educational reports (8 and 3%, respectively).

Inappropriate treatment in children with bloody diarrhea: clinical and microbiological studies.

It is suggested that in dysentery physicians should treat empirically, as early treatment seems to improve outcome. A constantly updated knowledge of the relative frequency of enteropathogens and their sensitivity to antimicrobials is needed to choose the right therapy. We studied microbiological and clinical findings in 119 children with bloody diarrhea in Mexico City.