Colonic mucosal changes in nude mice associated with orthotopic xenografts of human colon cancer cells

Summary We used the nude mouse tumour xenograft model to study the pathogenesis of mucosa alterations in the large bowel surrounding a carcinoma. In mouse colonic mucosa overlying HT-29 colonic carcinoma xenografts in the caecum, the crypts were elongated in comparison with those in distant mucosa and also frequently showed a shift towards sialomucin production. These features, which are comparable with socalled transitional mucosa (TM) in man, were absent in control animals inoculated with Indian Ink instead of HT-29 cells. Although the localization of the proliferative cell compartment in mouse colonic mucosa overlying HT-29 xenografts appeared to be confined to the lower half of the crypt as in normal mucosa, the relative length of the DNA synthesizing cell compartment along the crypts was slightly elongated. These data strongly suggest that TM should be regarded as a secondary phenomenon rather than a premalignant change in large intestinal epithelium and that higher proliferative activity of epithelial cells contributes little to the elongation of crypts in TM.     

Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in a rural area of Japan. The Funagata diabetes study

PURPOSE: To determine the prevalence of type 2 diabetes and impaired sucrose tolerance (IGT) among people aged 40 and over in a rural area, Funagata, Japan, by using a 75-g oral glucose tolerance test (OGTT), and to compare the prevalence to that obtained from a more urban area, Hisayama, Japan. METHODS AND RESULTS: Total eligible subjects for the Funagata study were 3526. Among them, 140 were confirmed to have diabetes judged by the 1985 WHO criteria. A 75-g OGTT was conducted, excluding the 140 known cases of diabetes. The 1985 WHO criteria were used to classify the current diabetes status of participants. The overall participation rate was 74.4%. The prevalence of diabetes (known and newly diagnosed cases combined) was 9.1% for men and 10.8% for women. The prevalence of IGT was 12. 0% for men and 16.5% for women. Age-adjusted prevalence (using 1990 Japanese census) of diabetes and IGT in men in Hisayama is two times higher than in Funagata (12.8% vs. 6.8% for diabetes, 19.5% vs. 10. 3% for IGT). Age-adjusted prevalence of IGT in women in Hisayama is significantly higher than in Funagata. CONCLUSIONS: The prevalence of type 2 diabetes among people aged 40 and over is approximately 10% even in a rural area of Japan. Prevalence of diabetes and IGT is much higher in an urban area than in a rural area in Japan.     

Does the perception of downloading speed influence the evaluation of web-based lectures?

Medical schools put little emphasis upon education on public health, even though public health has played an important role in this century. One way to harness its benefit in order to improve global health in the 21st century is to globally share lectures on public health through the Internet. We have developed the Supercourse comprising of web-based learning modules on epidemiology in a standardized format with the size of each web page less than 10 kilobytes. A cross-sectional observational study was conducted to investigate the association of the perception of the access speed to Web-based lectures by teachers with their perception of lecture quality. There were 223 teachers who rated the lectures: 72% were from North America or Western Europe, 40% had taught epidemiology, and 14% reported that the speed of access was slow. Odds ratio of above-average rating among those who reported that the speed of access was fast relative to those who reported that the speed of access was slow was 4.25 (2.03-8.91; P = 0.001). The odds ratios were similar and significant after taking into account several other factors, including the variation of rating across lectures, region, and experiences in teaching epidemiology. The results indicate that the perception of the quality of Web-based lectures is related to the speed of access to a web page. The speed of access may be as important, if not more important, as the content itself. This suggests that, to share educational materials on the Web globally for teachers, one must consider not only the content, but also how people at local sites gain access to the Internet.     

Small intestinal metastasis from renal cell carcinoma exhibiting rare findings

Small intestinal metastasis from renal cell carcinoma (RCC) has only rarely been described. We report two patients who developed small bowel metastases from RCC showing different clinicopathological characteristics. Both patients underwent hemilateral nephrectomy for RCC and developed lung metastases metachronously or simultaneously. One patient developed occlusive ileus caused by multiple polypoid tumours composed of sarcomatoid tissue in the jejunum shortly after nephrectomy. The other patient presented melaena due to bleeding from a Borrmann 2-like tumour in the jejunum six years after nephrectomy. Clinically, his disease was slow-growing. Sarcomatoid histology and Borrmann 2-like tumour in this report are rare findings in metastatic tumour of RCC in the small bowel.     

Colonic expression of heme oxygenase-1 is associated with a better long-term survival in patients with colorectal cancer

OBJECTIVE: Heme oxygenase-1 (HO-1) has emerged as a crucial mediator of mucosal defense in the gastrointestinal tract. Its metabolic pathway products, biliverdin/bilirubin and carbon monoxide, can reduce oxidative stress and inflammation, and promote resistance to apoptosis. The role of HO-1 in gastrointestinal malignancies, however, remains to be elucidated. The purpose of this study was to analyze HO-1 expression in human colon adenoma and cancer samples. MATERIAL AND METHODS: Fifty-five paraffin-embedded surgical specimens of colorectal cancer and 19 colonic adenoma samples were stained immunhistochemically for HO-1 expression using an anti-HO-1 monoclonal antibody. HO-1 expression was evaluated independently by two different investigators and subsequently correlated to clinical data and patients' life expectancy. RESULTS: Focal HO-1 expression could be documented in 41.8% (23/55) of patients with colorectal cancer. HO-1 expression in colonic adenoma was detectable in 36.8% (7/19) of cases. The rate of lymphatic tumor invasion was significantly lower in colorectal cancer samples expressing HO-1 (p=0.048). Additionally, fewer lymph node metastases were found in colorectal cancer samples with HO-1 expression, but these differences did not reach statistical significance. Mean observation period was 65.87+/-3.96 months. Kaplan-Meier analysis showed a significantly better survival for colorectal cancer patients with colonic HO-1 expression (p=0.018). CONCLUSIONS: This study demonstrates that colonic HO-1 may be a prognostic marker of colorectal-cancer outcome.