Impact of 5-fluorouracil on glucose metabolism and pancreatic pathology in rats / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the impact of 5-fluorouracil (5-FU) on glucose metabolism and pancreatic pathology.</p><p><b>METHODS</b>Twenty Wistar rats were divided into 5-FU group(n=10, chemotherapy was administered intraperitoneally to animals at a dose of 20 mg/kg daily for continuous 5 days) and control group (n=10, sodium chloride was administered intraperitoneally to animals with the same dose at the same time ). Glucose tolerance was evaluated 2 and 7 days following 5-FU treatment by serial measurement of blood glucose before and after an oral glucose load. Plasma insulin concentration was determined by radioimmunoassay. Pancreatic pathology was examined with morphological method and the ultrastructural changes of β cells were observed by transmission electron microscope.</p><p><b>RESULTS</b>Fasting blood glucose level was significantly higher in the 5-FU group than that in the control group [(7.6±0.9) mmol/L vs. (4.6±0.6) mmol/L at day 2; (8.9±1.0) mmol/L vs. (4.7±0.6) mmol/L at day 7, P<0.01]. Insulin releasing test indicated that the early phase insulin response to glucose load was significantly diminished in animals treated with 5-FU at day 2. Insulin level was significantly lower in the 5-FU group than that in the control group at 30 min (P<0.01). The peak secretion time of plasma insulin in 5-FU group was at 60 min, similar to the control group; and plasma insulin level decreased more slowly. Plasma insulin level was higher in 5-FU groups than in control groups on 120 min and 180 min. At day 7, Insulin level was lower in the 5-FU group than that in the control group on 60 min, and the peak secretion time of plasma insulin was delayed to 120 min. Plasma insulin level was significantly increased in 5-FU group than that in control group on 180 min(P<0.01). No gross histopathological damage to the pancreas was observed at day 2 and 7 following administration of 5-FU. The structural changes of mitochondria were mainly the quantities of secretory granule diminished at day 7 under transmission electron microscope. Dilated rough endoplasmic reticula, swollen mitochondria, and the presence of adipose drops in lysosomes were found in few cells.</p><p><b>CONCLUSIONS</b>5-FU-induced hyperglycemia appears to be mediated in part by a relatively deficient insulin secretion to glucose stimulation. A relative deficiency in insulin secretion following 5-FU treatment appears to be related to β cells function impairs with islet cell ultrastructural changes induced by 5-FU.</p>

Association of MLH1 gene 415G/C polymorphism with colorectal cancer in Chinese / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the possible etiological role of MLH1 gene 415G/C polymorphism in sporadic Chinese colorectal cancer (CRC) patients.</p><p><b>METHODS</b>Ninety-seven sporadic CRC patients and 138 normal controls were collected from Hubei Provincial Cancer Hospital and the People's Hospital of Wuhan University. In addition, five CRC families including 6 patients and their 19 first-degree relatives were also recruited. Genomic DNA was extracted from peripheral blood samples. Gene mutation was analyzed by PCR-RFLP. MLH1 mRNA expression in colorectal mucosa was analyzed by RT-PCR.</p><p><b>RESULTS</b>The frequency of MLH1 gene CC genotype was significantly higher in sporadic CRC patients than that in controls (P=0.035, OR=5.29, 95% CI: 1.07-26.04). In the CRC families, the C allele frequency of CRC patients and their relatives was increased, compared with sporadic CRC patients and normal controls, respectively (P=0.003 and P=0.006). MLH1 mRNA expression of colorectal mucosa was similar in different genotypes.</p><p><b>CONCLUSION</b>MLH1 gene 415G/C polymorphism might be a risk factor to sporadic CRC in Chinese. The mutation does not affect the MLH1 mRNA expression. For first-degree relatives from CRC families, carriers of MLH1 415C allele have a high risk to CRC.</p>