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Helicobacter pylori (HP) may transform from helical bacillary forms to coccoid forms after several days' in vitro incubation. The authors examined 111 consecutive gastrectomy specimens for the presence of coccoid forms of H pylori. Tissues from 64 stomachs (57.7%) showed colonization by H pylori, including 49 cases (76.6%) of adenocarcinoma, 14 cases (21.9%) of benign peptic ulcer, and 1 case (1.6%) of malignant lymphoma. Of these, coccoid forms of H pylori were identified in 53 cases (82.8%). In hematoxylin-and-eosin-stained sections coccoid forms of H pylori appeared as solid, round, basophilic dotlike structures. Under an electron microscope, coccoid forms of H pylori appeared as U-shaped bacilli, with the ends of the two arms joined by a membranous structure. Ultrastructural findings were identical to those from cultures of H pylori. With anti-Helicobacter antibody, coccoid forms of H pylori were positively stained by immunoperoxidase. Helical bacillary forms of H pylori invariably coexisted with the coccoid forms. By semiquantitative analysis, the number of coccoid forms in adenocarcinoma was significantly (P > .01) greater than that in benign peptic ulcers. This study confirms that H pylori can exist in coccoid forms in the human stomach. Coccoid forms should be distinguished from the pathogenic or nonpathogenic bacterial cocci, fungal spores, and cryptosporidia that may colonize the human stomach.

TRPC channels are a group of Ca(2+)-permeable nonselective cation channels that mediate store-operated and/or agonist-stimulated Ca(2+) influx in a variety of cell types. In this study, we extensively examined the expression patterns of TRPC homologs in human vascular tissues. RT-PCR amplified cDNA fragments of TRPC1 (505 bp), TRPC3 (372 bp), TRPC4 (499 bp), TRPC5 (325 bp), TRPC6 (509 bp), and TRPC7 (187 bp) from RNA isolated from cultured human coronary artery endothelial cells. In situ hybridization yielded strong labeling of TRPC1,3-6 in the endothelial and smooth muscle cells of human coronary and cerebral arteries. TRPC7 labeling was exclusively found in endothelial cells but not in smooth muscle cells. Results from immunohistochemical staining were consistent with those from in situ hybridization. Similar expression patterns of TRPC homologs were also observed in arterioles and vaso vasora. In conclusion, our study indicates that TRPC homologs are widely expressed in human vessels of all calibers, including medium-sized coronary arteries and cerebral arteries, smaller-sized resistance arteries, and vaso vasora. These results suggest a ubiquitous role of TRPC homologs in regulating blood supply to different regions and in controlling arterial blood pressure.

Background: The ferret is a key animal model to study the transmission characteristics of influenza viruses.Results: Characterization of ferret respiratory tract tissues identified influenza virus glycan receptors.Conclusion: Species-specific influenza virus glycan receptors were identified.Significance: Our findings provide new insights into the usefulness of ferrets in the study of influenza virus infection.

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Recombinant human nerve growth factor (rhNGF) was expressed and secreted by Chinese hamster ovary cells and purified to homogeneity using ion-exchange and reversed-phase (RP) chromatography. The isolated product was shown to be consistent with a 120-amino-acid residue polypeptide chain by amino acid composition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), RP-HPLC, and mass spectrometry and with an N-terminal sequence consistent with that expected from the cDNA for human nerve growth factor. By size-exclusion chromatography, rhNGF behaves like a noncovalent dimer. Limited enzymatic digests of the 120-residue monomer produced additional species of 118 (trypsin, removal of the C-terminal Arg119-Ala120 sequence) and 117 (trypsin plus carboxypeptidase B, removal of the C-terminal Arg118-Arg119-Ala120 sequence) residues. Each of these species was isolated by high-performance ion-exchange chromatography and characterized by amino acid and N-terminal sequence analyses, SDS-PAGE, RP-HPLC, and mass spectrometry. All three species were present in the digests as both homodimeric and heterodimeric combinations and found to be equipotent in both the chick dorsal root ganglion cell survival and rat pheochromocytoma neurite extension assays.

Prevalence of LMPl deletion variant of Epstein-Barr virus in nasopharyngeal carcinoma and gastric tumors in Hong KongChang et al. (1995) have described a prevalent strain of Epstein-Burr virus (EBV) associated with T-cell lymphoma and nasopha yngeal carcinoma (NPC) in the Taiwanesepopulation. The strain was identical to a previously reported NPC-EBV strain from a cell line -1510 originating from Taiwan, which showed Xho I restriction enzyme polymorphism in exon 1 and a 30-bp deletion in exon 3 of the latent membrane protein 1 (LMP1) gene (Chang et al., 1995Chen et al., 1992.We have also identified a prevalent EBV strain (HKNPC-EBV) in nasopharyngeal carcinoma in Hong Kong, where the incidence of this cancer is high. The sequence of the LMPl gene of this prevalent strain is basically similar to that reported by Chang et al. (1995) but with some specijic differences.We examined 74 NPC primary biopsies from Southern Chinese patients in Hong Kong and 3 NPC xenograjis (HK-2117 HK-666 and HK-1915) by PCR-RFLP analysis, and observed loss of the Xho I site in exon I of the LMPl gene in all NPC biopsies and xenograjis. A 30-bp deletion at the C-termind region was also identified in 69/ 74 (93%) biopsies and 313 (100%) xenografts. Upon SSCP and direct DNA sequencing analysis, a prevalent strain with a specific sequence of the LMPl gene was observed in 64174 (86%) biopsies and 213 xenograjis (HK-2117 and HK-666). This sequence was characterized by a 30-bp deletion at codons 346 to 355 (nt 168285 to 168256), and a unique G to A mutation at codon 335 (nt 168317, GGC to GAC), resulting in a change of amino acid from glycine to aspartic acid. The 30-bp deletion site was similar to that reported for the NPC-CAO strain which had a Northern Chinese origin (Hu et al., 1991), but differs from that of the Taiwanese strain with deletion site at nt 168282 to 168253 reported by Chang et al. (1995). Otherwise, mutations at codon 322 (CAA t o w ) , 334 (CAG to CGG), 338 (TTG to TCG) and 342 (GGA to GGT) were identical to those seen in the Taiwanese strain. The mutational change at codon 335, however, has not been reported previously in either the NPC-CAO strain from Northern China or NPC-1510 strain from Taiwan.Furthermore, 2 other minor EBVstrains (I and II) were also identijied in our NPC biopsies. The first of these minor strains (I), found in 5174 (7%) biopsies and one xenograft (HK-1915), did not have the afore-mentioned base substitution at codon 335, although the 30-bp deletion and codon changes in the C-terminus of the LMPl gene were otherwise the same as in the prevalent gpe. The second minor strain (II), found in 5/74 (7%) NPC biopsies, did not have the 30-bp deletion at the C-terminus, although loss of the Xho I site at the N-ter-minus was found in all these cases. This minor strain II also consistently exhibited base substitutions at codon 331, 338, 342,344 and 355. To determine whether the prevalent EBV strain in our NPC biopsies could be found in other EBV-related tumors in Hong Kong, we also investigated tumor tissue...

SUMMARY:Many nasopharyngeal carcinoma (NPC) biopsy specimens contain Epstein-Barr virus (EBV). However, the response of NPC cells to EBV infection in vitro and in vivo is not well characterized. In this experiment we infected NPC cells with EBV particles through endocytosis of a complex of EBV immunoglobulin A (IgA) secretory component (SC) protein to observe the response of host cells to the foreign viral infection in vitro. We found that EBV particles were endocytosed and stabilized in NPC nuclei 24 hours after infection; the EBV genomes were then gradually decreased after serial passages within 3 to 4 weeks by the following pathway: the EBV genomes first moved toward the nuclear envelope from the center of the nucleus; after crossing the nuclear envelope, they moved into the cytoplasm and toward the plasma membrane and were discharged by exocytosis. At the 10th day of EBV infection, EBV-latent membrane protein-1 and Epstein-Barr nuclear antigen (EBNA)-1 protein expressions could be detected, but not EBV-viral capsid antigen. Observation of EBNA-1 protein and host growth factor and cytokine gene expressions in the weeks after incubation revealed that the EBNA-1 protein expression was decreased proportionally with decrease of EBV genome. The mRNA expression of epithelial growth factor receptor, transforming growth factor (TGF)-␣, interleukin (IL)-1␤, IL-6, and granulocyte-macrophage colony-stimulating factor increased within 1 to 2 weeks after infection, and gradually recovered to the original level at 3 to 4 weeks, whereas the mRNAs of TGF␤1, TGF␤ receptor type I (TGF␤RI), TGF␤R type II, IL-8, and tumor necrosis factor-␣ remained unchanged. It is concluded that in vitro EBV infection in NPC cells results in increase of certain growth factor and cytokine gene expressions in host cells. The change in gene expression returns to the original level approximately 3 to 4 weeks after infection because of exocytosis of EBV DNA by the infected cells through an unidentified mechanism. (Lab Invest 2000, 80:1149-1160.N asopharyngeal carcinoma (NPC) is one of the most common cancers among Chinese living in Taiwan, Singapore, and South China (Chan, 1990;de The, 1982; Lin et al, 1971). The etiological factors for this cancer are not yet well defined. Epstein-Barr virus (EBV) has been suggested to be closely associated with NPC (Ablashi et al, 1991;Klein et al, 1974;Niedobitek et al, 1991;Zur Hausen et al, 1970). Hereditary and other environmental factors, such as eating salted fish and exposure to sulfuric acid vapor, have also been associated with NPC (Armstrong et al, 1983;Hirayama and Ito, 1981;Ho et al, 1999).For identification of the actual relationship between EBV and NPC, we have previously established nine NPC cell lines in our laboratory (Lin et al, 1990(Lin et al, , 1993.Results from the observation of EBV in these nine NPC cell lines and biopsy specimens revealed that EBV was present in only five of nine lines and was an episomal, but not an integrated form, in the infected cells. In each EBV-infected cell line, on...