Study of polymorphisms in the TP53 and RB1 genes in children with retinoblastoma in northern Mexico.

PURPOSE: To determine the frequency and association of polymorphisms in the TP53 and RB1 genes with clinical characteristics in a group of children with retinoblastoma (RB) in northern Mexico. METHODS: A prospective, longitudinal, and analytical study of 11 patients diagnosed with RB was conducted. Endpoint PCR and high-resolution real-time PCR were performed. Chi-square and Student t tests were used to evaluate associations between variables. Allelic frequencies, as well as genotypic and Hardy-Weinberg equilibriums, were evaluated using Guo and Thompson's method. RESULTS: We found a statistically significant difference between the polymorphism RB1-GG/rs9568036 and tumor chemoresistance (p<0.05). The allelic variants RB1-AA and AG/rs9568036 were determined to be associated with tumor chemosensitivity (p<0.05). A statistically significant relation between the polymorphism RB1-GG/rs9568036 and males (p = 0.0386), rate ratio (RR) = 2.0 (95% confidence interval [CI] = 0.76-5.32), as well as between the allelic variants RB1-AA and AG/rs9568036 and females (p = 0.0027), RR = 8.0 (95% CI = 1.28-50.04), was observed. We also observed a statistically significant association between the rs1042522 polymorphism in the TP53 gene and unilateral presentation of the disease. CONCLUSIONS: The rs9568036 polymorphism in the RB1 gene and the allelic variants can be associated with type of response to medical therapy and associated with male sex, while the allelic variant rs1042522 polymorphism in the TP53 gene is associated with the unilateral presentation of the disease in a group of Mexican children with RB.

Guidelines for the diagnosis and treatment of extrahepatic portal vein obstruction (EHPVO) in children.

INTRODUCTION: Extrahepatic portal vein obstruction is an important cause of portal hypertension among children. The etiology is heterogeneous and there are few evidences related to the optimal treatment. AIM AND METHODS: To establish guidelines for the diagnosis and treatment of EHPVO in children, a group of gastroenterologists and pediatric surgery experts reviewed and analyzed data reported in the literature and issued evidence-based recommendations. RESULTS: Pediatric EHPVO is idiopathic in most of the cases. Digestive hemorrhage and/or hypersplenism are the main symptoms. Doppler ultrasound is a non-invasive technique with a high degree of accuracy for the diagnosis. Morbidity is related to variceal bleeding, recurrent thrombosis, portal biliopathy and hypersplenism. Endoscopic therapy is effective in controlling acute variceal hemorrhage and it seems that vasoactive drug therapy can be helpful. For primary prophylaxis of variceal bleeding, there are insufficient data for the use of beta blockers or endoscopic therapy. For secondary prophylaxis, sclerotherapy or variceal band ligation is effective; there is scare evidence to recommend beta-blockers. Surgery shunt is indicated in children with variceal bleeding who fail endoscopic therapy and for symptomatic hypersplenism; spleno-renal or meso-ilio-cava shunting is the alternative when Mesorex bypass is not feasible due to anatomic problems or in centers with no experience. CONCLUSIONS: Prospective control studies are required for a better knowledge of the natural history of EHPVO, etiology identification including prothrombotic states, efficacy of beta-blockers and comparison with endoscopic therapy on primary and secondary prophylaxis.

Chronic gastritis associated with Helicobacter pylori in Mexican children: histopathological patterns.

The objective of this study was to analyze the histopathological patterns of inflammation, distribution, severity, and degree of gastric mucosa of Helicobacter pylori (Hp)-infected children in Northern Mexico, as well as the correlation between colonization density and inflammation intensity. We carried out a cross-sectional study of gastric biopsies performed on children ranging from 2 to 17 years of age who underwent upper gastrointestinal endoscopy for diverse gastroduodenal disorders. This study includes only children who were found to be Hp carriers, with positive results for tests of Hp antigens in feces and in gastric biopsy studies. We studied 107 patients (age 8.2 ± 3.7 years). In 47.7% of patients, the density of Hp colonization was low; only 21.5% had a marked density. Mononuclear leukocyte infiltration showed a similar distribution. Thirty-seven percent of patients had follicular gastritis. An acute inflammatory response was absent in 65% and mild in 20.6% of patients. When inflammation was present, it was primarily located in the antrum (79%). There were no cases of intestinal metaplasia or atrophy. A link was found between Hp density and age, infiltration by mononuclear cells, the presence of follicular gastritis, and the level of neutrophil infiltration (P  =  0.001). Despite the high rates of Hp infection in the region, the histopathological findings in these children were mild and were limited primarily to the antral mucosa. These data indicate the need to study the behavior of this disease in children in diverse study populations to provide localized prevention and treatment strategies.

Duplicación del tubo digestivo manifestada como quiste lingual: Caso clínico y revisión de la literatura / Enteric duplication presented as lingual cyst: Case report and literature review

Introducción: Los quistes de duplicación intestinal son anormalidades poco frecuentes que se presentan principalmente en el período perinatal, y pueden causar problemas respiratorios y para la alimentación. Los quistes sublinguales de duplicación intestinal pueden presentar solo epitelio del aparato digestivo, del respiratorio o de ambos. En los dos últimos casos se denominan coristomas. Caso clínico: Se describe un caso de un paciente de 10 meses de edad que presentó una masa quística sublingual desde el nacimiento. Se realizó la resección total con abordaje transoral y la reconstrucción de la lengua en planos. La pieza quirúrgica resultó una estructura quística de contenido mucoide, de 23 × 17 × 11 mm y color marrón. El revestimiento del quiste estaba formado por mucosa gástrica, con epitelio foveolar y glándulas formadas por células parietales y principales. Conclusiones: El quiste de duplicación intestinal es una entidad extremadamente rara. El abordaje quirúrgico es eficaz y curativo con mínima morbilidad y mortalidad, sin recurrencia en su seguimiento.

Background: Intestinal duplication cysts are rare abnormalities that occur primarily during the perinatal period and may cause problems for feeding and/or breathing. Sublingual intestinal duplication cysts can present either gastrointestinal epithelium or respiratory or both; the latter two cases are called choristomas. Case report: We describe a 10-month-old infant who presented a sublingual cystic mass at birth. Total successful transoral resection and reconstruction of the tongue was performed in planes. The surgical specimen was a brown cystic structure of mucoid content with dimensions of 23 × 17 × 11 mm. The cyst lining consists of gastric mucosa with foveolar epithelium and glands composed of parietal and chief cells. Conclusions: The intestinal duplication cyst is an extremely rare entity. The surgical approach is effective and curative with minimal morbidity and mortality and without recurrence in follow-up.

Immunochromatographic monoclonal test for detection of Helicobacter pylori antigen in stool is useful in children from high-prevalence developing country.

BACKGROUND: Tests to detect Helicobacter pylori antigens in feces for diagnosis of infection in children demonstrate controversial results. One novel and fast monoclonal test improves diagnostic accuracy in adults, but clinical evidence of its usefulness at pediatric age is insufficient to date. The objective of this work was to evaluate the diagnostic accuracy of this test in a sample of Mexican children. METHODS: We conducted a transversal study in 150 selected children with digestive symptoms suggestive of organic disease in whom a clinical history was conducted in addition to a fast monoclonal test (ImmunoCardSTAT HpSA, Meridian Diagnostics) performed by immunochromatography. Patients were submitted to endoscopy and histopathologic study. RESULTS: Of the 150 children (mean age 7.8 +/- 4.7 years), 107 (71.3%) were positive for the test, and presence of H. pylori was confirmed histologically in 109 (72.7%) children, with sensitivity of 96.3% (95% CI = 95.8-96.8), specificity of 95.1% (95% CI = 93.9-96.4), and accuracy of 96.0% (95% CI, -95.6 to -96.3); pretest probability was 0.73, while post-test probability was 0.98. Infection rate and test accuracy increased with age. CONCLUSIONS: This test is useful for detecting H. pylori infection in children of all ages, and is a good alternative for screening studies in developing countries with elevated prevalence, due to its being fast, noninvasive, inexpensive, and easy to carry out.