Epidemiology of colorectal cancer in Asia

The prevalence of colorectal cancer is increasing in Asia. However, the age‐standardized rate has reached a plateau in some countries. Some studies have shown a male predominance difference and increasing risk in the elderly, but not in the younger population. ‘Right shifting’ of colorectal cancer, not accountable by difference in age or the indications for endoscopic examination, has also been noted. Westernized diet is associated with colorectal cancer, but controversy remains on how it causes colorectal cancer. Alcohol consumption, obesity, diabetes mellitus, consumption of red and processed meat and cigarette smoking are linked to bowel cancer epidemiologically. Only high dietary calcium has a consistent negative (or ‘protective’) effect. The efficacy of fish oil, vitamin D, soy, phytoestrogens, folate, methionine, riboflavin and vitamin B6 has not been established. Aspirin and non‐steroidal anti‐inflammatory drugs use decrease risk of colorectal cancer after 5–10 years of use. There is no evidence for a detrimental effect of proton pump inhibitors or benefit of statins in colorectal cancer. In conclusion, there is a rising trend and prevalence of colorectal cancer in Asia. Dietary modification or supplementation may not be effective in preventing colorectal cancer. Surveillance of colorectal cancer in high‐risk groups, according to current recommendation, is probably most effective.     

Optimal pulse sequence for imaging hepatic metastases

For magnetic resonance (MR) imaging studies in which the diagnosis is dependent on image contrast, it is essential that an optimized imaging technique be used. Using detection of hepatic metastases as an example, the authors describe a rational strategy for optimizing MR imaging technique. First, for a single patient with proved hepatic metastases, a variety of imaging sequences is discussed and evaluated, leading to characterization of the patient's hepatic tissues. Then the characteristics of the tissues of a representative patient population are presented. These are used to determine two optimal pulse sequences that maximize the achievable signal difference-to-noise ratio achievable in a fixed imaging time. The recommended imaging sequence for detection of hepatic metastases at 0.15 T is either a three-dimensional volume spin-echo (SE) sequence with echo time (TE) = 12 msec and repetition time (TR) = 184 msec or a multisection inversion recovery sequence with TE = 22 msec, inversion time = 250 msec, and TR = 1,375 msec. The variation of this optimum pulse sequence with field strength is also presented.     

女儿茶多糖NLC-A的分离纯化及化学结构

女儿茶为民间常用中草药。经水提取,去蛋白及小分子杂质得到女儿茶多糖(NLC-A)粗制品。再经Cellex D,Sepharose 6B和Sephadex G-100相继柱层析,得到均一组分NLC-A,分子量为1.2×10⁴,NLC-A经全水解,甲基化反应,过碘酸盐氧化,Smith降解,KI-I₂反应和IR证明其结构为以α(1→4)-D-葡萄糖为主链,并在o-6位有分枝的葡聚糖。     

Expression of the multidrug resistance-associated P-glycoprotein (P- 170) in 59 cases of de novo acute lymphoblastic leukemia: prognostic implications [see comments]

Immunocytochemical detection of the multidrug resistance (MDR)- associated membrane protein (P-170) was performed at time of diagnosis in a series of 36 children and 23 adults with acute lymphoblastic leukemia (ALL) using two monoclonal antibodies JSB1 and C219. Immunophenotypes were obtained in all cases and karyotypes were analyzed in 37 cases. Detection with JSB1 or with C219 led to similar results in terms of positive cells and cases, but the intensity of staining was higher with JSB1. In the populations studied, the rate of first complete remission differed between MDR-positive and MDR-negative in adult patients only (56% v 93%, respectively, P = .05). Of the 16 MDR-positive patients who had presented a first complete remission, 13 (81%) relapsed, compared with 13 of 35 (37%) MDR-negative (P = .008) patients. A higher rate of relapse among MDR-positive compared with MDR- negative patients was observed in adults and in children taken separately (adults 100% v 46%; children 73% v 32%, respectively). The survival rates (Kaplan-Meier method) were significantly higher in MDR- negative compared with MDR-positive populations as a whole (P = .002) and among children (P = .05) and adults (P = .03) taken separately. Event-free survival curves followed this trend. The percentage of second complete remission was very low in the MDR-positive group (15%) compared with 38% for the MDR-negative group. These results were shown by multivariate analysis to be independent of age, immunophenotypes, and karyotypes and clearly show the importance of MDR phenotype detection in ALL.