Scielo RSS <![CDATA[Revista médica del Hospital General de México]]> vol. 82 num. 2 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[Evolution of host-parasite relation in humans]]> <![CDATA[Importance of breast milk in the development of intestinal microbiota]]> At birth, mammals make the transition from aseptic surroundings to a pathogen-filled environment, it is known that different factors modulate immune responses, but in the digestive tract breast milk (BM) may play an important role in the maturation of the immune response, mainly in relation to the gut. In this sense, it has been demonstrated that besides nutrients and antibodies, BM contains cells, hormones, cytokines, and growth factors. The objective of this work was to evaluate the importance of BM in the development of both the piglet and the intestinal microbiota. For this, two groups of piglets were formed; one suckled with the saw and the other suckled with BM substitute. Stool samples were taken for bacterial identification, this was done through the VITEK-system, and subsequently, the serotype was identified. The results showed that the piglets suckled with BM substitute 18 (100%) presented diarrheal episodes from the 2nd day, of this group two piglets presented bloody diarrhea, and the group fed with the mother only 7 (38.8%) had diarrheic episodes from the 5th day. All isolates 285 were Escherichia coli. The largest number of isolates obtained of piglets suckled with BM belonged to serotype O103:H28 and largest number of isolates obtained of piglets suckled with milk substitute belonged to serotype O166:H21. Serotypes belonged to bloody diarrhea were O103:H28 and O166:H21. The present work showed the importance of BM both in the body development of the piglet and in the protection against infections. <![CDATA[Comparative study between diarrheagenic <em>Escherichia coli</em> virotypes from Mexico City and San Luis Potosí]]> The distribution and frequency of Escherichia coli virotypes can vary considerably from region to region, due to the geographical characteristics, the degree of social lag as well as the population of each region. Therefore, the objective of the present work was to compare Escherichia coli isolated from children with diarrhea obtained from two states with different levels of social lag and establish virotypes, adhesion to HEp-2 cells, biofilm formation, and antimicrobial resistance of this bacterium. In the present work, we compared E. coli isolated from children with diarrhea obtained from the City of San Luis Potosí (S.L.P.) with E. coli isolated from children with diarrhea of Mexico (City CDMX), with the purpose of identifying and establishing virotypes, adherence to HEp-2 cells, formation of biofilms, and antimicrobial resistance of these bacteria. The results showed that the percentage of virotypes found in S.L.P., were higher with respect to the virotypes found in the CDMX, being enterotoxigenic the most frequent virotype for both populations. The incidence of this virotype was higher for E. coli isolated from S.L.P., and the statistical analysis showed p &lt; 0.000. The incidence of the enteroinvasive and EHEC virotypes was higher in the state of S.L.P., with p &lt; 0.000. The adhesion phenotype, both aggregative and diffuse, was related to the presence of the aat and astA genes. The tests to determine the production of biofilms in strains of E. coli, allowed us to determine that the method in Congo red agar, were the most effective for its evaluation. In relation to the antimicrobials tested, a higher percentage of resistance of the E. coli strains of the CDMX was observed, in relation to the strains of S.L.P., with a statistically significant difference of p &lt; 0.05. <![CDATA[Development of the intestinal immune response in the suckling rat model: Mesenteric lymph nodes as potential inducers of B cells during the development of the intestinal immune response]]> At birth, mammals make the transition from aseptic surroundings to a pathogen-filled environment; hence, the gut is constantly exposed to high antigenic. The mucosal epithelial layer of the gut forms the interface between the external and internal environments of the gastrointestinal tract (GIT) that in newborns allows the passage of nutrients for the maturation of cells in different tissues. In addition to this physiological barrier, an immunological barrier is created and maintained by immune cells located in the gut-associated lymphoid tissue (GALT). The first contact of the pathogens with the host is carried out through the GALT, and it constitutes the most extensive and complex part of the immune system. Aim: The aim of the study was to investigate the development of the intestinal immune response in the suckling rat model. Methods: The location and temporal appearance of the different subsets of B-cells in the GALT and the spleen of suckling and weaning rats were studied histologically using the immunoperoxidase method. Results: The results showed that the number of B-cells of the suckling and weaning rats increases progressively with age; on day 21 when weaning took place, there was an important increase in all B-cells subsets. Mesenteric lymph nodes (MLN) showed the most apparent B-cell subset changes. Interestingly, subpopulations of IgA B-cells and IgG B-cells appear early at 3 days old in NLM unlike Peyer's patches where these subpopulations appear at 12 and 6 days, respectively, which may indicate that the immune response is originally triggered in intestinal MLN. <![CDATA[Association of diarrheagenic <em>Escherichia coli</em> with virotypes and sensitivity to antimicrobials in children of the Mexico City]]> Diarrheal diseases continue to be a public health problem worldwide. Escherichia coli is one of the main etiological agents of diarrhea. The aim of the present work was to identify, through the polymerase chain reaction assay, the main virulence genes that characterize the different E. coli pathotypes that cause diarrhea in children under 5 years of age. A total of 151 stool samples from children with diarrhea were analyzed, of which 284 strains of E. coli were identified and DNA extracted. The virulence genes LT, STx1, STx2, EAST1, eaeA, bfpA, ial, aat, and astA were identified. Of the 284 strains analyzed, 179 (63.1%) were positive for at least one of the genes and 105 (36.9%) were negative for the nine genes studied. Of the 63%, enterotoxigenic E. coli was identified in a total of 63%, enterohemorrhagic E. coli in 25.0%, enteroaggregative E. coli in 25%, enteroinvasive E. coli in 20.7%, and enteropathogenic E. coli in 11.4%; These data are due to a strain of E. coli sharing genes with another strain. Children under 2 years old were the most affected. The adhesion phenotype, both aggregative and diffuse, was related to the presence of the aat and astA genes. The antibiogram showed that the strains of E. coli were resistant to more than three antibiotics, mainly ampicillin, cephalothin, amoxicillin/clavulanic acid, sulfamethoxazole-trimethoprim, and sensitive to amikacin, cefotaxime, and cefoxitin. <![CDATA[Perioperative management of the patient with Myasthenia gravis]]> Myasthenia gravis is an autoimmune disease in which autoantibodies interact postsynaptic nicotinic acetylcholine at the neuromuscular junction which decreases the capacity of the terminal plate to transmit the nerve signal. For the anesthesiologist may be difficult extubation at the end of the procedure, especially if interference drugs are used at the neuromuscular junction. This review addresses the steps to be followed in perioperative management with flowcharts. <![CDATA[Chordoma with extension to the nasal cavity: A case presentation]]> Chordoma is a rare malignant tumor originating from remnants of the notochord, slow-growing, but locally destructive, of presentation in the clivus, spinal cord region and sacrum. It is diagnosis can be a challenge for the various differential to consider that can be found with more often, especially when manifested as bulky lesions in the nasopharyngeal area and/or with symptoms secondary to it. As if that were not enough small biopsies often are insufficient for correct diagnosis. <![CDATA[Hydatid pulmonary cyst: A case report]]> Lung Echinococcosis is a parasitic disease caused by tapeworms from Echinococcus spp genus. It is a global distribution disease when people have closed relation with animals like dogs and lambs. Humans are accidental hosts. The liver is the most affected site followed by the lungs. We present one case of a patient who works with lambs and come from an endemic area in our country.