An immunohistochemical assay for staining C. pylori is described. The method is compared with cultivation of C. pylori and observation of campylobacter-like organisms (CLOs) in hematoxyline-eosine (HE) stained sections. Eighteen biopsies from which C. pylori was cultivated but not seen in HE stained sections and three culture negative biopsies with CLOs seen in HE stained sections were selected from 331 biopsies including 113 culture positive biopsies. There were agreements between cultivation of C. pylori and CLOs seen in HE stained sections in the remaining 310 biopsies. Fourteen of the 18 and one of the three biopsies were found positive by the immunohistochemical assay. In addition 21 culture-positive control biopsies and one of 18 culture-negative control biopsies were also found positive. When the immunohistochemical assay was compared with cultivation the predictive value of positive result is 93% and of negative result 89%. By this method we were able to detect single organisms and no cross-reactions to other curved bacteria on the gastric epithelium were observed.
A primer-set was designed for specific detection of genes that encode for 16S rRNA of Helicobacter pylori, using direct polymerase chain reaction (PCR). The primers were selected in the hypervariable regions, derived from a complete small subunit 16S rRNA sequence of the reference strain H. pylori CCUG 17874. The primer-set amplified a 537 base pair (bp) sequence specifically from chromosomal H. pylori DNA. Amplification of purified chromosomal H. pylori DNA was achieved at concentrations as low as 1 femto gram (fg), equivalent to 5 bacteria. Furthermore, as few as 1 lysed H. pylori cell was detected by this PCR technique. The specificity of the primers was 100%, since purified chromosomal DNA was detected from all 32 various H. pylori isolates, whereas no other bacteria species were detected, whether related to Helicobacter or not. The 16S rDNA primers successfully detected H. pylori in antral biopsy specimens collected from infected patients.
A case of bilateral malignant Brenner tumor of the ovary in a 43-year-old woman was studied by light- and electron microscopy. The morphologic criteria of this rare lesion are discussed and the pertinent literature reviewed.
