Reduction of colonic carcinogenesis by wheat bran independent of fecal bile acid concentration

It has been reported previously that populations with a decreased concentration of fecal bile acids have a lower incidence of colon cancer. We examined the importance of fecal bile acid dilution by wheat bran (WB) in inhibiting colonic tumorigenesis in an experimental animal model. Male F344 rats received oral doses of the colon carcinogen 1,2-dimethylhydrazine [CAS: 540-73-8] and were assigned randomly to groups fed one of four semipurified diets for 26 weeks. The diets were fiber-free (FF), 10% WB, FF + bile salts, or WB + bile salts. The amount of bile salts added was adjusted to produce a fecal bile acid concentration in the group fed WB + bile salts equal to that found in the FF groups. Fecal bile acid concentrations at 12 and 24 weeks in the WB + bile salts group were similar to those in the FF group. Gross and microscopic findings at necropsy revealed a reduced total number and multiplicity of colon tumors in both bran-fed groups. Although the fecal bile acid concentrations of the FF and WB + bile salts groups were equal, the latter showed a significant reduction in tumor yield.     

Influence of meal distribution of wheat bran on fecal bulk, gastrointestinal transit time and colonic thymidine kinase activity in the rat

Male Fischer 344 rats were fed either fiber-free (FF), continuous 10% wheat bran (CWB) or intermittent 50% wheat bran (IWB) diets for 6 wk to investigate possible alterations in physiological effects associated with colon cancer (fecal bulk, transit time, colonic cell proliferation) induced by meal distribution of the bran. The FF and CWB groups consumed unvaried diets throughout the day. The IWB group consumed two consecutive meals of a 50% bran diet for a total of 4 hr each day followed by a fiber-free diet for the remaining hours of the day. Similar daily quantities of bran were consumed in the CWB and IWB groups. Dry fecal weights rose significantly and transit times declined in both bran-fed groups independent of the meal distribution of bran. Colonic cell proliferation (estimated by thymidine kinase activity) was similar in all groups. The results suggest that these physiological effects of wheat bran are independent of the meal distribution of the bran.     

Geriatric trauma: resource use and patient outcomes.

INTRODUCTION: Elderly patients who suffer trauma have a higher mortality and use disproportionately more trauma resources than younger patients. To compare these 2 groups and determine the outcomes and characteristics of elderly patients, we reviewed patients in these 2 groups admitted and treated in our tertiary care provincial trauma centre. METHODS: From the provincial trauma registry we selected a cohort of 40 geriatric patients (group 1) (> or = 65 yr of age) with an ISS of 16 or more who were admitted to and spent time in our trauma service for more than 48 hours and compared them with a similar randomly selected cohort of 44 patients (group 2) aged 20-30 years. Family physicians were contacted for follow-up of these patients 2 years after discharge. We considered length of hospital stay, complications, disposition of the patients and use of consultation services. RESULTS: Patients in group 1 had a mean age of 72.1 years (range from 65-98 yr) and a mean ISS of 27.3 (range from 17-50). Patients in group 2 had a mean age of 26.3 years (range from 22-29 yr) and a mean ISS of 26.3 (range from 17-54). Hospital stay was significantly longer in the group 1: 34.5 days (95% confidence interval [CI]: 24-44 d) versus 21.6 days (95% CI: 15-28 d). More elderly patients experienced complications (35 v. 13, p < 0.001) and required medical consultations (35 v. 26, p < 0.001). In-hospital death rates were 8% (3 of 40) and 4% (2 of 44) respectively (p = 0.3). Fewer geriatric patients could be discharged home (35% [14 of 40] v. 27% [22 of 44], p = 0.056) or to rehabilitation facilities (28% [11 of 40] v. 34% [15 of 44], p = 0.3). Five geriatric patients were discharged to nursing homes (p = 0.007). Of the geriatric patients discharged to rehabilitation facilities or home, 75% were independent 2 years after discharge. CONCLUSIONS: Aggressive care for geriatric trauma patients is warranted, and resources should be directed toward rehabilitation. Based on our findings, we expect that creating a directed care pathway for these patients, targetting complications and earlier discharge, will further improve their outcomes.     

Effects of graded levels of high-molecular-weight carrageenan on colonic mucosal thymidine kinase activity.

Graded levels of high-molecular-weight carrageenan were fed to male Fischer 344 rats to investigate the effects of carrageenan on colonic cell proliferation. Four groups of 7 rats consumed diets containing 0 (control), 0.65, 1.31, or 2.61% carrageenan ad libitum for 4 wk. These levels were designed to simulate (on a milligram-per-kilogram basis) 25, 50, and 100 times the maximal human carrageenan intake. After an overnight fast, the rats were anesthetized, and the colonic mucosa was removed and homogenized. A supernatant was prepared and assayed for total protein and thymidine kinase activity (a marker for cell proliferation). Increasing levels of carrageenan resulted in stepwise increases in total mucosal protein and in thymidine kinase specific (units per milligram of protein) and total (units per centimeter of colon) activity. However, increases in thymidine kinase activity were statistically significant only at the highest dose of carrageenan. No histological abnormalities were associated with any level of carrageenan feeding. These results suggest a clear dose-response increase in colonic mucosal cell proliferation with increasing doses of carrageenan; however, the effect at doses approximating 19 times maximal human intake was not statistically different from that for control rats under the conditions of this study.     

Sweat gland response to exercise in the heat among pre-, mid-, and late-pubertal boys.

Sweating rate (SR) of boys is lower than that of men. To assess the association between the response of individual sweat glands and physical growth and maturation, three groups of circumpubertal boys cycled at 50% VO2max in a climatic chamber (42 degrees C, 20% relative humidity). Based on Tanner staging (pubic hair), 16 were classified as prepubertal (PP, Tanner 1), 15 as midpubertal (MP, Tanner 2-4), and five as late-pubertal (LP, Tanner 5). Population density (PD) of the heat-activated sweat glands, the mean area of sweat drops (DA), and the proportion of skin covered by sweat (%A) were measured by skin photography and computer-assisted imaging analysis. Other measurements included rectal and skin temperatures (Tre, Tsk, respectively), heart rate (HR), and total body SR. The rise in HR, Tre and Tsk did not differ among groups. Whole body SR was significantly higher in the LP group compared with PP (PP = 4.95 +/- 0.23, MP = 5.79 +/- 0.20, LP = 6.70 +/- 0.42 ml.min-1.m-2) (mean +/- SEM). PD was significantly higher in the PP group (PP = 128 +/- 8, MP = 97 +/- 9, LP = 74 +/- 9 glands.cm-2), while DA was higher in the LP group (PP = 5.47 +/- 0.59, MP = 6.92 +/- 0.47, LP = 12.83 +/- 1.41 microns2.10(4)). %A did not differ among groups. The calculated SR per gland was higher among the LP groups compared with the less mature ones (PP = 4.6 +/- 0.3, MP = 7.2 +/- 0.8, LP = 9.6 +/- 1.0 nl.min-1).(ABSTRACT TRUNCATED AT 250 WORDS)