Paired samples of plasma and peripheral blood mononuclear cells (PBMC) from 7 patients with posttransfusion hepatitis C were collected and studied for the presence of replicative forms of hepatitis C ...virus (HCV). RNA was extracted and tested for both positive and negative strands of HCV RNA by polymerase chain reaction. Positive-strand RNA of HCV was found in both plasma and PBMC of all 7 patients. However, negative-strand RNA was found in PBMC of 3 patients while none was found in the plasma. Levels of negative-strand RNA were about 10–100 times less than those of positive-strand RNA by semiquantification with serial dilution of viral cDNA. The results suggest that active infection and replication of HCV in PBMC is present in patients with posttransfusion hepatitis C and implicate the extrahepatic infection of HCV.
To investigate the intrafamilial transmission of hepatitis C virus (HCV) and related risk factors, anti-HCV antibodies in 186 family members of 48 index patients were studied. The index patients were ...anti-HCV-positive and had chronic liver disease. Overall, 10 family members (5.4%) were positive for anti-HCV, indicating a higher prevalence of anti-HCV among family members than among the Taiwanese general population. Spouses had the highest prevalence (21%) of anti-HCV, with older age and longer duration of marriage of index patients the most evident risk factors. HCV RNA, recovered from the infected couples by reverse transcription-nested polymerase chain reaction and subsequently sequenced directly, was identical at the nucleotide level in 3 of the 4 couples studied, and the remaining couple had a homology of >96%. These results strongly support that interspousal transmission may be the most important route of intrafamilial spreading of HCV, and thus sexual transmission, although with low efficiency, should be considered important in HCV infection.
Background: Endoscopic mucosal resection has become a popular alternative for the treatment of early-stage neoplasia of the gastrointestinal tract. However, there are still no data on the frequency ...of bacteremia associated with this form of treatment. Methods: We conducted a prospective study of 21 men and 17 women undergoing endoscopic mucosal resection with a cap-fitted panendoscope for upper gastrointestinal lesions. Blood cultures were performed before, 10 minutes after, and 4 hours after the procedure for both aerobic and anaerobic bacteria. Results: Blood culture at baseline was negative in all the patients. Two of 38 patients (5.3 %) had positive blood culture at 10 minutes after the procedure. The isolated microorganisms were Streptococcus salivarius and Corynebacterium species. All patients had negative blood cultures 4 hours later. None of these 38 patients had any symptoms or signs associated with infection. Conclusions: Bacteremia associated with endoscopic mucosal resection is infrequent and transient. (Gastrointest Endosc 2000;52:223-5.)
Sera from 14 patients with duodenal ulcer and their families were tested for IgG antibodies to Helicobacter pylori. Fourteen serologically negative patients and their families served as controls. ...Index patients and their family members who were serologically positive were advised to undergo endoscopic biopsy. Gastric biopsy tissues were subjected to HaeIII restriction analysis of nested polymerase chain reaction products of the urease gene. By serology, 28 (49.0%) of 57 in index families and II (27.5%) of 40 in control families tested positive. A higher prevalence rate was found in children of index patients (11/31,35.5%) than in those of control patients (1/18,5.6%; P < .05). On DNA analysis, II patterns were found in 13 patients, and 6 families underwent endoscopy. Children in 5 families exhibited identical patterns to those of their siblings and, in 3 of the 5 families, identical to the pattern of I of the parents. These results suggest that parent-tochild transmission and common infection source are probable causes of intrafamilial clustering of H. pylori.
Although the mechanism remains obscure, two histological subtypes of gastric carcinoma (GC), the diffuse and intestinal types, differ drastically in epidemiological, clinical, pathological and ...biological characteristics. We investigated whether the genetic alterations of several oncogenes and tumour suppressor genes could be correlated with the two histological subtypes. In 60 patients with GC, the overexpression of mutant p53 and c‐erbB‐2 oncoproteins was studied using immunohistochemical stains. Mutations of the p15 and p16 tumour suppressor genes were assessed by polymerase chain reaction, Southern blotting, and direct DNA sequencing. Overexpression of c‐erbB‐2 and p53 was found in 21 (35.0%) and 27 (45.0%) patients, respectively. Overexpression of the c‐erbB‐2 oncoprotein was more common in the intestinal type (15/32, 46.9%) and the advanced stage (19/45, 42.2%) than in the diffuse type (6/28, 21.4%) and the early stage (2/15, 13.3%) of GC (P<0.05). Similarly, p53 overexpression was more frequently found in the intestinal type (19/32, 59.4%) and the advanced stage (24/45, 53.3%) than in the diffuse type (8/28, 28.6%) and the early stage (3/15, 20.0%) of GC (P<0.05). Homozygous deletions of p16 in exon 1 were found in six (10.0%) patients. Five of them had the intestinal‐type advanced GC. Neither point mutations of p16 nor alterations of p15 were detected. The frequency of alterations of p53, c‐erbB‐2, and p16 was not related to sex and Helicobacter pylori infection. No correlation of genetic changes between any two genes was observed. Our preliminary results indicate alterations in the p15 gene were not important in gastric tumorigenesis, while infrequent homozygous deletions in the p16 gene play a limited role in tumour progression of intestinal‐type GC. Moreover, overexpression of c‐erbB‐2 and p53 is frequently encountered in the intestinal‐type advanced GC. Alterations of p53, c‐erbB‐2 and p16 genes may function independently of each other in gastric carcinogenesis. The association between genetic alterations and histological subtypes supports the notion that a distinct pathogenesis may exist in different histological subtypes.
To assess the contribution of hepatitis C virus (HCV) in liver disease in Taiwan, antibody to HCV (anti-HCV) was studied by radioimmunoassay in 392 patients with chronic liver disease and in 440 ...healthy adults and 444 subjects at risk. The anti-HCV prevalence was 0.95% in 420 volunteer blood donors, 90% in 100 hemophiliacs, and 81% in 58 parenteral drug abusers. AntiHCV was present in 6 (7.7%) of 78 hepatitis B surface antigen (HBsAg)-positive and 28 (65%) of 43 HBsAg-negative patients with chronic hepatitis, 3 (10%) of 31 HBsAg-positive and 13 (43%) of 30 HBsAg-negative cirrhotics, and 7 (17%) of 42 HBsAg-positive and 15 (63%) of24 HBsAgnegative patients with hepatocellular carcinoma (HCC). An outbreak of non-A, non-B hepatitis revealed 18% of 57 patients to bepositive for anti-HCV, and in 29 patients with posttransfusion hepatitis prospectively followed, 7 (24%) developed anti-HCV. Thus, HCV infection appears to playa relatively minor role in HBsAg-positive liver disease in Taiwan but is strongly associated with HBsAg-negative chronic liver disease and HCC. The infection is extremely common in hemophiliacs and parenteral drug abusers.
To investigate the prevalence of pS2 expression in gastric cancer with respect to tumor histopathology, intestinal metaplasia and Helicobacter pylori (H. pylori) infection, pathologic specimens of 91 ...patients with gastric cancer were immunostained for pS2. Such immunoreactivity was correlated with the status of H. pylori infection, tumor staging, histology, subtyping, and associated intestinal metaplasia. Positive pS2 staining was seen throughout all non‐neoplastic epithelia, and in all 9 patients with the complete type of intestinal metaplasia. In contrast, 21 of 45 incomplete type of intestinal metaplasia had negative pS2 staining (P<0.001), and 54 out of 91 tumors (59.3%) showed loss of pS2 expression in the cancer tissues proper. There was no correlation of pS2 expression with age, gender, depth of invasion, duodenal involvement, lymph node metastasis, venous invasion or H. pylori infection. Negative pS2 staining was significantly higher in the intestinal (74.5%) and Borrmann type I, II, III (64.2%) tumors than the diffuse (43.2%, P<0.005) and Borrmann type IV (20%, P<0.05) tumors. Our results indicate that loss of pS2 expression may occur as an early event in the malignant transformation process of intestinal‐type tumors.
A novel chiral metasurface composed of a chiral arrangement of nanoslits is developed. Controllable and remarkably strong chiral responses are achieved by taking advantage of the coupling between ...localized and propagating surface plasmon modes. The finding provides an extra degree of freedom in manipulating chiral responses.
To investigate the molecular mechanism of gastric carcinogenesis, we examined simultaneously the frequency of microsatellite instability and the immunoreactivities to ras, erbB-2, and p53 in 42 ...gastric adenocarcinoma tissues. Microsatellite instability, measured by DNA replication error, was detected in 33.3% (14/42) of patients with gastric carcinoma while positive immunostaining was demonstrated in 3.1% (1/32) for ras, 40.5% (17/42) for erbB-2, and 28.6% (12/42) for p53. There was no statistical difference between the intestinal type and the diffuse type of carcinoma with respect to microsatellite instability, ras, or erbB-2 expression. The expression of p53 occurred more frequently in the intestinal type of carcinoma (41.7%, 10/24) than in the diffuse type of carcinoma (11.1%, 2/18; P < 0.01). There was no association between microsatellite instability and ras or p53 expression, while enhanced expression of erbB-2 occurred more frequently in carcinomas with microsatellite instability (64.3%, 9/14) than in those without microsatellite instability (28.6%, 8/28; P < 0.05). Such a strong association between microsatellite instability and erbB-2 oncogene may be responsible for the increase of other oncogenic mutations and tumor progression in gastric carcinogenesis.
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