Publications by authors named "Petra Kaiser"

Background: Since asymptomatic hepatitis E virus (HEV) infections particularly affect children, there is a need for studies to determine the HEV seroprevalence among infants, children and adolescents.

Methods: The prevalence of anti-HEV IgG antibodies was determined in sera taken in 2008-2010 from 1646 children aged 0-17 years living in Germany. Antibody testing was carried out using the enzyme-linked immunosorbent assay recomWell HEV IgG as well as the recomLine HEV IgG/IgM distributed by Mikrogen.

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Stromal interaction molecule 1 (STIM1) deficiency is a rare genetic disorder of store-operated calcium entry, associated with a complex syndrome including immunodeficiency and immune dysregulation. The link from the molecular defect to these clinical manifestations is incompletely understood. We report two patients with a homozygous R429C point mutation in STIM1 completely abolishing store-operated calcium entry in T cells.

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Background: We determined antibodies to the pandemic influenza A (H1N1) 2009 virus in children to assess: the incidence of (H1N1) 2009 infections in the 2009/2010 season in Germany, the proportion of subclinical infections and to compare titers in vaccinated and infected children.

Methodology/principal Findings: Eight pediatric hospitals distributed over Germany prospectively provided sera from in- or outpatients aged 1 to 17 years from April 1(st) to July 31(st) 2010. Vaccination history, recall of infections and sociodemographic factors were ascertained.

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Unlabelled: Acute gastroenteritis (AGE) caused by rotavirus (RV) is a common disease among infants and toddlers, often leading to hospitalization and, in resource-poor countries, to death. However, little is known on specific complications of severe RV-positive (RV+) AGE and on the clinical course in chronically ill children. This was a retrospective analysis of data for children <5 years of age hospitalized due to AGE during six rotavirus seasons in three large German pediatric hospitals.

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Colony counting by spreading bacterial suspensions on plating media by various techniques is of general concern. Comparative studies between hand plating (Drigalski-spatula technique) for different time intervals and spiral plating resulted in significant differences in colony counts. Lower counts of Gram-negative bacteria were obtained by using hand plating for more than 10s, compared with short time hand plating (5s) or spiral plating.

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Mutations that impair expression or function of the components of the phagocyte NADPH oxidase complex cause chronic granulomatous disease (CGD), which is associated with life-threatening infections and dysregulated granulomatous inflammation. In five CGD patients from four consanguineous families of two different ethnic backgrounds, we found similar genomic homozygous deletions of 1,380 bp comprising exon 5 of NCF2, which could be traced to Alu-mediated recombination events. cDNA sequencing showed in-frame deletions of phase zero exon 5, which encodes one of the tandem repeat motifs in the tetratricopeptide (TPR4) domain of p67-phox.

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