Increasing multidrug resistance in Helicobacter pylori strains isolated from children and adults in Mexico.

The susceptibilities to three antimicrobials of 195 Helicobacter pylori strains isolated from Mexican patients is reported; 80% of the strains were resistant to metronidazole, 24% were resistant to clarithromycin, and 18% presented a transient resistance to amoxicillin. Resistance to two or more antimicrobials increased significantly from 1995 to 1997.

[Sodium diphenylhydantoin as a probable cause of pancreatitis]. / Difenilhidantoinato sódico como probable causa de pancreatitis.

INTRODUCTION: Drug-induced pancreatitis is much more common in children than in adults. Many drug have been implicated in its pathogenesis. Among the neuropsychiatric drugs only valproic acid, carbamazepine, clozapine and ergotamine have been reported. Phenytoin is commonly used for the treatment of epilepsy. It has been associated to pancreatitis only in two previous reports. CASE REPORT: Male adolescent who initiated with cerebellar hemorrhage due to an arteriovenous malformation. During his evolution he presented the following complications: pneumonia, two urinary tract infection, gastrointestinal bleeding and arterial hypertension. Eighteen days after admission he developed seizures and was treated with phenytoin. The next day he presented pancreatic symptoms and pancreatitis was confirmed by elevated enzymes and a CAT scan with pancreatic edema. Other etiologies were discarded. Pancreatic enzymes persisted high until phenytoin was stopped and have been within normal values after 18 months of follow-up. CONCLUSIONS: In this case three of the four Miller criteria have been fulfilled. We consider that the antiepileptic treatment was the direct cause of the pancreatitis because there was a clear temporal association of the symptoms with the initiation and suspension of the drug.

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. METHODS: An enzyme-linked immunosorbent assay (ELISA) for diagnosis of H. pylori infection using whole cell extracts was validated in 50 children with biopsy-confirmed infection. The IgG and IgA antibody responses against recombinant CagA and urease were compared by ELISA in 82 children with RAP and in 246 age- and sex-matched healthy children. RESULTS: The whole-cell extract ELISA had a sensitivity of 85 % and specificity of 87%. Children with RAP were more infected with H. pylori than were healthy control subjects; however, IgG and IgA CagA seropositivity was lower among those with RAP than among asymptomatic children (34% and 23% vs 76% and 55%, respectively; p < 0.0001). In both groups of children, the immune response to urease was low. CONCLUSION: A serodiagnosis of H. pylori infection using native strains was developed. The difference in the immune response between children with RAP and control subjects suggests that RAP occurs during the acute phase of H. pylori infection. Our results also suggest that urease is a poor immunogen.