[Validation of a simplified 13C-urea breath test method for the diagnosis of Helicobacter pylori infection]. / Validación de método simplificado de la prueba en aliento con urea-13C para diagnóstico de infección por Helicobacter pylori.

OBJECTIVE: To validate a simplified 13C-urea breath test (13C-UBT) method for the diagnosis of H. pylori infection. MATERIAL AND METHODS: Patients referred for gastrointestinal endoscopy and biopsy were included, and a 13C-UBT was performed after a 6-hour fast. Breath samples were collected in 10 ml glass tubes before and 30 min after the simultaneous administration of 50 mg of 13C-urea and 2 g of citric acid in 200 ml of water. All breath samples were analyzed using isotope ratio mass spectrometry. The diagnosis of H. pylori infection was established with a positive culture and/or positive histology and serology. RESULTS: Eighty-eight patients were included, 49 female and 39 male with a mean age of 45 +/- 15 yrs. Fifty-one patients (57.95%) were positive and 30 (34.1%) negative for H. pylori. Seven cases (7.95%) were considered undetermined. The sensitivity, specificity, positive predictive value, and negative predictive value for 13C-UBT were 90.2, 93.3, 95.83, and 84.8%, respectively. Accuracy was 91.4%. CONCLUSIONS: The simultaneous administration of 50 mg of 13C-urea and 2 g of citric acid represents an alternative for the non-invasive diagnosis of H. pylori infection.

Validación de método simplificado de la prueba en aliento con urea-13C para diagnóstico de infección por Helicobacter pylori / Validation of a simplified method of the 13C urea breath test for diagnosis

Objetivo: validar un método simplificado de la prueba enaliento con urea-13C (PAU-13Cs) para el diagnóstico de infecciónpor Helicobacter pylori (H. pylori), con administración simultáneade 50 mg de urea-13C y 2 g de ácido cítrico.Material y métodos: se estudiaron 88 pacientes (49 mujeresy 39 hombres); con promedio de edad 45 ± 15 años, referidospara endoscopia gastrointestinal y toma de biopsias. La PAU-13Csse realizó en ayuno. Se recolectaron las muestras de aire espiradoen tubos de cristal de 10 ml, antes y 30 minutos después de administrarsimultáneamente 50 mg de urea-13C y 2 g de ácido cítricodisueltos en 200 ml de agua. Las muestras se analizaron por espectrometríade masas. El diagnóstico de infección se considerócuando el cultivo y/o la biopsia y serología fueron positivas paraH. pylori.Resultados: cincuenta y un pacientes (57,95%) fueron positivos,30 (34,10%) negativos para H. pylori y 7 (7,95%) casos seconsideraron indeterminados. La sensibilidad, especificidad, valorpredictivo positivo y negativo de PAU-13Cs fue de 90,2, 93,3,95,8 y 84,8%, respectivamente. Con exactitud de 91,4%.Conclusión: la administración simultánea de 50 mg de urea-13C y 2 g de ácido cítrico, representa una alternativa para el diagnósticono invasivo de infección por H. pylori, debido a que conservala certeza diagnóstica de la PAU-13C

Objective: to validate a simplified 13C-urea breath test (13CUBT)method for the diagnosis of H. pylori infection.Material and methods: patients referred for gastrointestinalendoscopy and biopsy were included, and a 13C-UBT was performedafter a 6-hour fast. Breath samples were collected in 10ml glass tubes before and 30 min after the simultaneous administrationof 50 mg of 13C-urea and 2 g of citric acid in 200 ml ofwater. All breath samples were analyzed using isotope ratio massspectrometry. The diagnosis of H. pylori infection was establishedwith a positive culture and/or positive histology and serology.Results: eighty-eight patients were included, 49 female and39 male with a mean age of 45 ± 15 yrs. Fifty-one patients(57.95%) were positive and 30 (34.1%) negative for H. pylori.Seven cases (7.95%) were considered undetermined. The sensitivity,specificity, positive predictive value, and negative predictivevalue for 13C-UBT were 90.2, 93.3, 95.83, and 84.8%, respectively.Accuracy was 91.4%.Conclusions: the simultaneous administration of 50 mg of13C-urea and 2 g of citric acid represents an alternative for thenon-invasive diagnosis of H. pylori infection

Molecular detection of respiratory syncytial virus in postmortem lung tissue samples from Mexican children deceased with pneumonia.

BACKGROUND: Respiratory syncytial virus (RSV) is the major viral cause of severe respiratory infections in children younger than 2 years of age. Nevertheless there are not enough epidemiologic data about the role of RSV as a cause of infantile mortality from pneumonia, mainly in young children from developing countries Aim. To determine the frequency of RSV infection in lung tissue samples from Mexican children deceased with pneumonia, by reverse transcription (RT) and PCR. METHODS: Postmortem lung tissue samples from 98 children younger than 2 years of age who died of pneumonia during the period of 1989 to 1997 were studied. Paraffin was removed with xylene from 10-microm lung sections, the total RNA was extracted and complementary DNA was obtained by RT reaction. A nested PCR with the use of oligonucleotides specific for the F glycoprotein gene was developed. Samples negatives for RSV were tested for the absence of polymerase inhibitors and for complementary DNA integrity. RESULTS: Twenty-nine of the 98 (30%) children deceased with pneumonia were positive for RSV by RT-PCR; 8 were detected from 13 (62%) children with histopathologic diagnosis of viral pneumonia and 21 from 85 (25%) children with histopathologic diagnosis of bacterial pneumonia (P = 0.018). There was no significant difference in RSV infection according to age groups or seasonal pattern. CONCLUSIONS: RSV infection is frequent in Mexican children younger than 2 years of age who died of pneumonia. Although RSV was more common in viral pneumonia, mixed infections with RSV and bacterial pneumonia were also common.

Cola beverage consumption induces bone mineralization reduction in ovariectomized rats.

BACKGROUND: A significant association of cola beverage consumption and increased risk of bone fractures has been recently reported. The present study was carried out to examine the relationship of cola soft drink intake and bone mineral density in ovariectomized rats. METHODS: Study 1. Four groups of 10 female Sprague-Dawley rats were studied. Animals from groups II, III, and IV were bilaterally ovariectomized. Animals from groups I and II received tap water for drinking, while animals from groups III and IV each drank a different commercial brand of cola soft drink. After 2 months on these diets, the following were measured: solid diet and liquid consumption; bone mineral density; calcium in bone ashes; femoral cortex width; calcium; phosphate; albumin; creatinine; alkaline phosphatase; 25-OH hydroxyvitamin D, and PTH. RESULTS: Study 2. Two groups of seven ovariectomized rats were compared. Group A animals received the same management as the group III animals from study 1 (cola soft drink and rat chow ad libitum), while rats from group B received tap water for drinking and pair-feeding. After 2 months plasmatic ionized calcium, phosphate, creatinine, albumin, calcium in femoral ashes, and femoral cortex width were measured. Study 1. Rats consuming cola beverages (groups III and IV) had a threefold higher liquid intake than rats consuming water (groups I and II). Daily solid food intake of rats consuming cola soft drinks was one-half that of rats consuming water. Rats consuming soft drinks developed hypocalcemia and their femoral mineral density measured by DEXA was significantly lower than control animals as follows: group I, 0.20 +/- 0.02; group II, 0.18 +/- 0.01; group III, 0.16 +/- 0.01, and group IV, 0.16 +/- 0.01 g/cm(2). Study 2. To rule out the possibility that these calcium and bone mineral disorders were caused by decreased solid food intake, a pair-fed group was studied. Despite a lower body weight, pair-fed animals consuming tap water did not develop bone mineral reduction or hypocalcemia. CONCLUSIONS: These data suggest that heavy intake of cola soft drinks has the potential of reducing femoral mineral density.

[Kala-azar in Mexico: report of 2 cases]. / Kala-azar en México: informe de dos casos.

Visceral leishmaniasis is a rare parasitosis in our country; in a 30 year period only exists the report of five cases, three in the state of Puebla and two in the state of Guerrero. Now it has been identified another two cases in the state of Chiapas. In these patients the common presentation of the disease were fever, hepatosplenomegaly, hypergammaglobulinemia and pancytopenia. The parasite can be found in liver, spleen, lymph nodes and bone marrow macrophages. A definitive diagnosis depends on the demonstration of the parasite in tissue; spleen biopsy is the most useful because it is positive in 98% of the cases, in other tissues the amastigotes are seen in 50-80% of the cases. Negative PAS-stained smears maintains the diagnosis until another more specific method as electronic microscopy or culture is available. Pentavalent antimonial compounds are the drugs of choice and as an alternative or in case of failure amphotericin B can be used.

[Disseminated histoplasmosis in pediatrics. Report of a case]. / Histoplasmosis diseminada en pediatría. Informe de un caso.

We report a case of a female infant, from Acapulco Guerrero, Mexico. She had been sick for 45 days, with diarrhea and general malaise, fever during the last 20 days; at physical examination she was pale, with abdominal distention and hepatosplenomegaly. She had leukopenia, thrombocytopenia and anemia. The microscopic findings in the bone marrow sample were intracytoplasmic and extracellular bodies. Both bone marrow and blood cultures were positive for Histoplasma capsulatum. Seventy three pediatric cases of diseminated histoplasmosis have been described in the medical literature since 1934 to 1988. It is know that only about 1% of the persons that become infected will develop a diseminated disease.