Calcified fibrous nodules in the heart: a case report.
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Biomedical subjects
Publications and source records attributed to Siu-Tsan Yuen.
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CDX2 and liver-intestine (LI)-cadherin are intestine-specific markers and both are physiologically expressed in the small intestine and colon. Recent studies have demonstrated that CDX2 regulates LI-cadherin gene (CDH17) expression in colorectal cancer. The present study investigated the relationship of CDX2 and LI-cadherin expression in gastric cancer. One hundred and nine pairs of tumour and non-cancerous gastric mucosa were collected from gastrectomy specimens. Protein expression levels of CDX2 and LI-cadherin were determined by immunohistochemical staining. Semi-quantitative RT-PCR showed that the mRNAs of both CDX2 and CDH17 were highly expressed in tumour compared with non-cancerous mucosa. Overexpression of CDX2 was significantly associated with CDH17 in gastric adenocarcinoma. Furthermore, the expression of CDX2 and LI-cadherin proteins was strongly coupled in intestinal metaplasia. In conclusion, overexpression of CDH17 is significantly associated with CDX2.
BACKGROUND: Macrophage migration inhibitory factor (MIF) has emerged to be a pivotal cytokine in immune-mediated diseases. PATIENTS AND METHODS: To investigate the role of MIF in chronic hepatitis B infection, we studied two groups of hepatitis B surface antigen positive patients: group 1 (immune tolerant, n = 16) and group 2 (immune clearance, n = 16). Serum level of MIF was measured by enzyme-linked immunosorbent assay and intrahepatic expression of MIF, macrophage and T-cell localisation were detected by double immunohistochemistry. RESULTS: An increased serum MIF correlated significantly with increased serum alanine aminotransferase activity (r = 0.73, P < 0.001) and the severity of necroinflammatory injury (r = 0.642, P < 0.001). In group 2, there was marked MIF mRNA expression in all KP-1+ macrophages and CD45RO+ activated T cells and, to a lesser extent, in hepatocytes within inflammatory areas. In contrast to its mRNA expression, the cytoplasmic MIF protein level in hepatocytes, infiltrating macrophages and T cells within the inflammatory area was reduced, which probably contributed to the increased serum MIF level. CONCLUSIONS: Our data suggested that MIF played a role in sustaining cell-mediated hepatic injury during the immune-clearance phase of chronic hepatitis B infection.
Gastric cancer remains the second leading cause of cancer deaths worldwide. Patients usually present late with local invasion or metastatic diseases. The present study investigated the expression level of liver-intestine cadherin (LI-cadherin) by RT-PCR and its correlation with clinicopathological data in 71 pairs of tumor and non-cancerous gastric mucosa. Protein expression level of LI-cadherin was determined by Western blotting and immunohistochemistry. The mRNA of LI-cadherin was highly expressed in tumor as compared to non-cancerous mucosa. Lymph node metastasis was significantly associated with the expression of LI-cadherin (p=0.038). On multivariate analysis, T staging and LI-cadherin expression were found to be independent factors associated with lymph node metastasis.
The macrophage migratory inhibitory factor (MIF) plays a pivotal role in inflammatory and immune diseases; however, its role in gastrointestinal diseases has not been clarified. This study intended to determine the expression of MIF, by gastric epithelial cells, T cells, and macrophages, in Helicobacter pylori-induced gastritis. Sixty-four patients (30 males, 34 females; mean age, 47 years) referred for upper endoscopy were recruited. Biopsy specimens from the gastric antrum and corpus were obtained for (1) detection of H. pylori and histological examination, (2) single and double immunostaining to test for expression of MIF protein in epithelial cells, T cells, and macrophages, and (2) in situ hybridization for expression of MIF mRNA within the lamina propria. In mucosal specimens from each of the 2 sites, both the percentage of MIF(+) epithelial cells and the numbers of MIF mRNA(+) inflammatory cells, MIF(+) T cells, and MIF(+) macrophages were significantly higher in H. pylori-positive patients than in H. pylori-negative patients. Overall, the percentage of MIF(+) epithelial cells and the numbers of MIF mRNA(+) cells, MIF(+) T cells, and MIF(+) macrophages were higher in the antrum than in the corpus. The percentage of MIF(+) epithelial cells and the numbers of MIF mRNA(+) cells, MIF(+) T cells, and MIF(+) macrophages increased in chronic gastritis, but, in the absence of H. pylori infection, this increase disappeared for all except MIF(+) T cells. Therefore, H. pylori infection is associated with increased expression of the MIF protein and MIF mRNA in gastric epithelial and inflammatory cells; along with other cytokines, MIF may play a significant role in gastric inflammation related to H. pylori infection.
Expert opinions differ on the causal role of cigarettes and alcohol in colorectal cancer. This study investigates such associations in Hong Kong Chinese. A hospital-based case-control study was conducted from April 1998 to March 2000. Newly diagnosed colorectal adenocarcinoma and sex- and age-matched inpatient controls without gastrointestinal and malignant conditions were included. Structured interviews were conducted using a validated questionnaire to study any association of smoking, drinking and the lifelong extent of such exposures with colorectal cancer risk. We successfully interviewed 822 cases and 926 controls. Current regular cigarette smokers had an increased rectal cancer risk (adjusted OR = 1.44; 95% CI = 1.001-2.06). Increasing tertiles of smoking duration in ever smokers was also associated with increased rectal cancer risk (p trend = 0.038). An increased risk of colorectal cancer was found in current drinkers (adjusted OR = 1.42; 95% CI = 1.09-1.85) and in those who drank > or = 4 days (current and ex-drinkers) or > 4 units (ever and ex-drinkers) weekly. Moreover, colorectal cancer risk was found to decrease with increasing duration of drinking abstention (p trend = 0.006). This is the first report of a positive association between cigarette smoking and rectal cancer risk in a Chinese population. Current drinkers and those who drank regularly and heavily had increased colorectal cancer risk. Moreover, this study is the first to show that drinking cessation could be effective in reversing such increased risk in a duration-dependent manner. These new findings are important for cancer prevention and healthcare promotion.
Both chronic ulcerative colitis and smoking are associated with colorectal cancer in humans. In the present study, we investigated the effects of cigarette smoke (CS) exposure on inflammation-associated tumorigenesis in the mouse colon. Male balb/c mice were allocated into six groups: control, CS (2%), CS (4%), colitis, colitis + CS (2%) and colitis + CS (4%). They were given water or 3% dextran sulfate sodium (DSS) in drinking water for 7 days to induce colitis, with or without 1 h daily exposure to 2 or 4% CS. They were then allowed to drink water for 14 days. The cycle of 7 day DSS +/- CS/14 day H2O treatments were repeated twice. Mice were killed immediately or 1 month after the three cycles of treatments. Results indicated colonic adenoma was only found in the colitis group (one out of 11), Colitis + CS (2%) group (seven out of 12) and colitis + CS (4%) group (four out of five) 1 month after three cycles of DSS and/or CS treatment. CS exposure dose-dependently increased adenoma formation in mice with inflamed mucosa. CS exposure plus colitis was strongly associated with a high incidence of dysplasia (P < 0.01) and adenocarcinoma formation (P < 0.01) compared with induction of colitis alone. Colitis induced cell proliferation and apoptosis in colonic tissues. Cigarette smoking significantly attenuated the apoptotic effect by DSS probably via the induction of anti-apoptotic protein bcl-2. The ratio of apoptosis over proliferation was also significantly lower in the colitis + CS groups. Vascular endothelial growth factor and angiogenesis in the colon were also increased by cigarette smoking in animals with colitis. In conclusion, CS promotes inflammation-associated adenoma/adenocarcinoma formation in the mouse colon in a dose-dependent manner. This tumor development is associated with the inhibition of cellular apoptosis and supported by increased angiogenesis.
Hepatitis B virus (HBV), a serious infectious and widespread human pathogen, represents a major health problem worldwide. Chronic HBV infection has a very high risk of evolving into hepatocellular carcinoma. Although considerable progress was made during the recent past, the pathogenesis of HBV infection is still elusive and a definite diagnosis of HBV infected liver information still relies on biopsy histological test. In this report, we used proteomics technology to globally examine HBV infected serum samples aiming at searching for disease-associated proteins that can be used as serological biomarkers for diagnosis and/or target proteins for pathogenetic study. By comparing with normal and HBV negative serum samples, we found that at least seven proteins were significantly changed in HBV infected sera. These greatly altered proteins were identified to be haptoglobin beta and alpha2 chain, apolipoprotein A-I and A-IV, alpha1-antitrypsin, transthyretin and DNA topoisomerase IIbeta. The alteration of these proteins is displayed not only in quantity but also in patterns (or specificity), which can be correlated with necroinflammatory scores. In particular, apolipoprotein A-I presents heterogeneous change in expression level with different isoforms and alpha1-antitrypsin produces evidently different fragments implying diverse cleavage pathways. These unique phenomena appear specific to HBV infection. A combination simultaneously considering the quantities and isoforms of these proteins could be a useful serum biomarker (or index) for HBV diagnosis and therapy.
BACKGROUND & AIMS: Impaired T-cell reactivity is believed to be the dominant cause of chronic hepatitis B virus (HBV) infection. We characterized HBV-specific T-cell responses in chronic hepatitis B surface antigen carriers who received bone marrow from HLA-identical donors with natural immunity to HBV and seroconverted to antibody to hepatitis B surface antigen. METHODS: T-cell reactivity to HBV antigens and peptides was assessed in a proliferation assay, the frequency of HBV core- and surface-specific T cells was quantified directly by ELISPOT assays, and T-cell subsets were analyzed by flow cytometry. RESULTS: CD4+ T-cell reactivity to HBV core was common in bone marrow donors and the corresponding recipients after hepatitis B surface antigen clearance, whereas none reacted to surface, pre-S1, or pre-S2 antigens. Furthermore, CD4+ T cells from donor/recipient pairs recognized similar epitopes on hepatitis B core antigen; using polymerase chain reaction for the Y chromosome, the recipients' CD4+ T lymphocytes were confirmed to be of donor origin. The frequency of core-specific CD4+ and CD8+ T cells was several-fold higher than those specific for surface antigen. CONCLUSIONS: This study provides the first evidence in humans that transfer of hepatitis B core antigen-reactive T cells is associated with resolution of chronic HBV infection. Therapeutic immunization with HBV core gene or protein deserves further investigation in patients with chronic hepatitis B.