[Risk of D-lactate acidosis while receiving acarbose].
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Acarbose↗
Biomedical subjects
H Kasper
Publications and source records attributed to H Kasper.
[Modification of fecal bile acid excretion by fish oil in healthy probands].
Several studies indicated a protective effect of fish oil on colon carcinogenesis which might be due to alterations in prostaglandin E2 synthesis of the colonic mucosa. Additional effects on fecal bile acid excretion may also play a role since especially secondary bile acids are known to act as promoters in colon cancer development. In the present study possible influences on bile acid excretion were investigated in 12 healthy volunteers whose daily diet was supplemented for 4 weeks with 11 g of fish oil (FO) and corn oil (CO) per day, respectively. Fecal bile acids were analyzed by gas-liquid-chromatography. Fecal excretion of total bile acids was not different during the periods of FO and CO-supplementation (301.9 vs. 320.3 mg/day). However, a non-significant trend to a lower daily excretion of the secondary bile acid lithocholic acid was found after FO compared to CO-ingestion (99.6 vs. 109.4 mg/day; p = 0.22). Since secondary bile acids are known promoters of colon carcinogenesis, these findings may implicate a favorable situation with respect to colon cancer prevention.
Adult↗
Influence of starch fermentation on bile acid metabolism by colonic bacteria.
Secondary bile acids (BA) may be involved in the pathogenesis of colorectal cancer. In vivo, starch malabsorption has been shown to reduce fecal excretion of secondary BA. The present in vitro study was performed to investigate the effect of starch fermentation on BA metabolism by colonic bacteria. Fecal samples of healthy volunteers were incubated in anaerobic batch cultures for 48 hours with the primary bile acids cholic (0.6 g/l) and chenodeoxycholic acid (0.4 g/l). Media were starch free or enriched with starch (10 g/l). The pH was controlled and held at 6 or 7. In the starch-free incubations, secondary BA were rapidly formed, and degradation of primary to secondary BA was complete within 24 hours. The formation of secondary BA was partially inhibited by the addition of starch to the media. This effect was stronger at pH 6 than at pH 7. Starch was rapidly and completely fermented. In conclusion, this study showed that formation of secondary BA by fecal bacteria is inhibited when starch is simultaneously fermented, an effect that is mainly, but not completely, explained by reduction of pH.
Bacteria, Anaerobic↗
Missing anti-proliferative effect of fish oil on rectal epithelium in healthy volunteers consuming a high-fat diet: potential role of the n-3:n-6 fatty acid ratio.
Several studies have indicated dietary fish oil (FO) as a protective agent in colon carcinogenesis. Rectal cell proliferation as an intermediate biomarker of cancer risk was shown to be reduced by dietary FO in patients with adenomatous polyps and healthy subjects consuming a low-fat diet. Because the synthesis of prostaglandins (PG) which seem to be involved in this process is dependent on the ratio of n-3:n-6 fatty acids in the diet, the present study was designed to investigate whether this FO effect is also detectable in volunteers eating a high-fat diet (50% of energy) with a low n-3:n-6 ratio of 0.25. Twelve healthy volunteers received in addition to a controlled basal diet either FO (4.4 g n-3 fatty acids/day) or corn oil supplements (double-blind, crossover) for two 4-week periods. No significant differences between the two study periods were found for rectal cell proliferation as assessed by bromodeoxyuridine immunohistochemistry and ornithine decarboxylase activity, as well as for mucosal PGE2 release and mucosal membrane fatty acid composition. The results emphasize the importance of dietary n-3:n-6 ratio in determining the effects of FO on rectal cell proliferation.
Administration, Oral↗
[Hydrogen metabolism in the large intestine--physiology and clinical implications].
During the anaerobic metabolism of the colonic bacterial flora short chain fatty acids and the gases hydrogen (H2) and carbon dioxyde (CO2) are produced. In about 50% of a European and North-American population and in 90% of rural black Africans, methane is generated from H2 and CO2. In methane-negative individuals, sulfate reducing bacteria utilize H2 to reduce sulfate to sulfide. Methanogenesis and sulfate reduction are usually mutually exclusive. A competition exists for the common substrate hydrogen which is potentially regulated by the availability of sulfate in the colonic lumen. Other bacteria can use H2 to reduce CO2 to acetate (homoacetogenesis). Methane is an inert gas and has probably no direct effect in man. The metabolites of sulfate reduction (mercaptides, hydrogen sulfide) are toxic and hydrogen sulfide is supposed to play a role in the pathogenesis of ulcerative colitis. All H2-utilizing metabolisms reduce the gaseous volume in the colon and thus prevent flatulence. In patients with pneumatosis cystoides intestinalis methanogenesis is absent and sulfate reduction is insignificant. This deficiency provides an explanation for the massive H2-excretion in those patients and their symptoms.
Colitis, Ulcerative↗
Effect of free glutamine and alanyl-glutamine dipeptide on mucosal proliferation of the human ileum and colon.
BACKGROUND/AIMS: Glutamine (Gln) is considered a trophic factor for small intestinal epithelia, which is important during severe illness. Its use in parenteral nutrition is precluded by its instability, a problem that may be overcome by use of the stable dipeptide L-alanyl-L-glutamine (Ala-Gln). The hypothesis was tested that Gln or Ala-Gln may stimulate cell proliferation not only in the ileum but also in the proximal and distal colon and, thus, may contribute to the gut barrier function. METHODS: Biopsy samples from the normal human ileum, proximal colon, and rectosigmoid were incubated for 4 hours with Gln (2 mmol/L), Ala-Gln (2 mmol/L), and saline (control). Cells in S phase were labeled with bromodeoxyuridine. In longitudinal crypt sections labeled and quiescent cells were counted. RESULTS: Gln as well as Ala-Gln stimulated crypt cell proliferation in the ileum, proximal colon, and rectosigmoid colon. In ileal specimens, labeling was greater in the entire crypt, whereas in both colonic regions, the trophic effect was confined to the basal crypt compartments. CONCLUSIONS: Gln and Ala-Gln have trophic effects not only in the ileum, but also in the proximal and distal colon. This could be important during parenteral nutrition when mucosal atrophy may weaken the gut barrier.
Adult↗
Does yogurt enriched with Bifidobacterium longum affect colonic microbiology and fecal metabolites in health subjects?
Diet-induced changes in the colonic microflora seem to play a role in colon carcinogenesis. In this study the effects of a yogurt (500 mL/d for 3 wk) enriched with Bifidobacterium longum and 5 g lactulose/L (A) on the fecal bacterial flora and various risk indexes for colon carcinogenesis were tested in 12 healthy volunteers and compared with a conventional yogurt (B). Increased excretion of bifidobacteria (P < 0.017) was found after consumption of both yogurts compared with the prestudy periods, whereas cultural counts of aerobes and anaerobes were not different. Breath-hydrogen exhalation was elevated and mouth-to-cecum transit time was accelerated in the period of yogurt A ingestion (P < 0.05) whereas no differences were found for oral-anal mean transit time, stool weight and pH, and fecal concentrations of short-chain fatty acids, bile acids, and neutral sterols. The results generally indicate great stability of the human fecal flora to this kind of dietary intervention.
Adult↗
Antagonistic effects of deoxycholic acid and butyrate on epithelial cell proliferation in the proximal and distal human colon.
Colon cancer is a major malignant disease in Western countries where--for unknown reasons--it occurs predominantly in the distal colon. Fecal secondary bile acids are an important risk factor whereas butyrate may be a protective agent. In this in-vitro study biopsies from the normal ascending and sigmoid colon of 24 subjects were incubated with 5 microM DCA (proximal vs. sigmoid colon) or DCA and DCA plus 10 mM butyrate (DCA vs. DCA/BUT, only sigmoid colon) and cell proliferation measured by bromodeoxyuridine immunohistochemistry. Whole crypt labeling index (LI) after DCA-incubation was similar in the ascending (15.4%) and sigmoid colon (15.4%) indicating an equal mucosal response of the two colonic subsites to DCA. Compared to DCA/BUT, incubation with DCA alone resulted in a significantly higher LI for the whole crypt (16.8 vs. 11.4%, p < 0.01) and for the upper 40% of the crypt (4.5 vs. 0.8%, p < 0.01). This may indicate a butyrate-related decrease in the susceptibility for colon cancer. Since luminal concentrations of DCA and butyrate are influenced by dietary interventions the findings of this study may be of particular interest with regard to colon cancer development and prevention.
Butyrates↗
Proliferation of human colonic mucosa as an intermediate biomarker of carcinogenesis: effects of butyrate, deoxycholate, calcium, ammonia, and pH.
A high-fat/high-protein diet has been reported to promote colon cancer by increasing luminal bile acid and ammonia concentrations, whereas butyrate, calcium, and low colonic pH may have protective effects. In this study, bromodeoxyuridine labeling of colonic epithelium was investigated after incubating biopsies from the ascending colon of 70 patients with HCl (20 mM, pH 6.0), butyric acid (H-BUT, 20 mM, pH 6.0), sodium butyrate (Na-BUT, 10 mM, pH 8.0), CaCl2 (10 mM), calcium butyrate (Ca-BUT, 10 mM), ammonium butyrate (NH4-BUT, 10 mM), deoxycholic acid (DCA, 5 microM), and a combination of DCA and Na-BUT (DCA/Na-BUT, 5 microM/10 mM). Compared to NaCl, H-BUT and Na-BUT increased the whole crypt-labeling index significantly, whereas HCl and CaCl2 had no effect. Reduced labeling, however, occurred with Ca-BUT in comparison to equimolar Na-BUT. No differences in the labeling indexes were found for NH4-BUT compared to Na-BUT, but increased labeling with expansion of the proliferative zone to the upper 40% of the crypt was seen with DCA compared to NaCl. DCA-induced hyperproliferation was abolished by coincubation with DCA/Na-BUT. These data suggest that butyrate, calcium, and DCA have complex influences on mucosal proliferation. Since luminal concentrations of these compounds are influenced by dietary interventions, the findings of this study may be of particular interest with regard to colon cancer development and prevention.
Adult↗
Effects of fish oil on rectal cell proliferation, mucosal fatty acids, and prostaglandin E2 release in healthy subjects.
BACKGROUND: Experimental studies have indicated dietary fish oil as a protective agent in colon carcinogenesis. Prostaglandins have been suggested to be involved in this process. In the present study, the effects of fish oil on rectal cell proliferation (i.e., intermediate biomarker of cancer risk), mucosal membrane fatty acids, and prostaglandin E2 (PGE2) release were investigated in 12 healthy volunteers. METHODS: In addition to a controlled basal diet, the test subjects received either fish oil (4.4 g omega-3 fatty acids/day) or corn oil supplements for two 4-week periods in a double-blind, crossover trial. Rectal cell proliferation was determined by bromodeoxyuridine immunohistochemistry and ornithine decarboxylase activity. After 2-hour incubation with bromodeoxyuridine, PGE2 concentration in the incubation medium was measured by radioimmunoassay. Mucosal membrane fatty acids were analyzed by gas chromatography. RESULTS: Bromodeoxyuridine labeling index (9.2% vs. 10.9%; P < 0.05), ornithine decarboxylase activity (19.7 vs. 36.4 pmol.mg protein-1.h-1; P < 0.005), and PGE2 release from rectal biopsy specimens (435.5 vs. 671.5 pg/mg wet tissue; P < 0.05) were significantly lower during the fish oil than the corn oil period, whereas membrane fatty acids were not statistically different. CONCLUSIONS: The results support the hypothesis that dietary fish oil may protect against colon cancer.
Adult↗
[Diabetic gastroparesis and gallbladder disease. Ultrasound diagnosis after multiple-component meals].
Thirty insulin-dependent diabetics (16 women, 14 men, mean age 37.7 [17-74] years) and 12 controls (eight women and four men; aged 20-58 years) were studied by real-time ultrasound before and after each of three meals to assess gastric and gallbladder motility. The diabetics were grouped according to the results into those without (n = 17) and those with diabetic autonomic neuropathy (n = 13). Antral cross-section provided the criterion for gastric emptying. It decreased significantly more slowly in diabetics with autonomic neuropathy than in the other two groups. The difference during the postprandial observation period of 240 min became the greater the longer the interval after the test meal (multivariance analysis: P < 0.001). Gallbladder emptying, too, was slowest in diabetics with autonomic neuropathy (P < 0.05). These results indicate that abnormalities of gastric and gallbladder emptying in diabetics can be recognized by measuring antral cross-section and longitudinal gallbladder area on fasting and 180 min after a test meal.
Adolescent↗
Effect of butyrate enemas on the colonic mucosa in distal ulcerative colitis.
Short-chain fatty acid irrigation has been shown to ameliorate inflammation in diversion colitis. In this study the effect of butyrate enemas was tested in 10 patients with distal ulcerative colitis who had been unresponsive to or intolerant of standard therapy for 8 weeks. They were treated for 2 weeks with sodium butyrate (100 mmol/L) and 2 weeks with placebo in random order (single-blind trial). Before and after treatment, clinical symptoms were noted and the degree of inflammation was graded endoscopically and histologically. Rectal proliferation was assessed by autoradiography. After butyrate irrigation, stool frequency (n/day) decreased from 4.7 +/- 0.5 to 2.1 +/- 0.4 (P less than 0.01) and discharge of blood ceased in 9 of 10 patients. The endoscopic score fell from 6.5 +/- 0.4 to 3.8 +/- 0.8 (P less than 0.01). The histological degree of inflammation decreased from 2.4 +/- 0.3 to 1.5 +/- 0.3 (P less than 0.02). Overall crypt proliferation was unchanged, but the upper crypt-labeling index fell from 0.086 +/- 0.019 to 0.032 +/- 0.003 (P less than 0.03). On placebo, all of these parameters were unchanged. These data support the view that butyrate deficiency may play a role in the pathogenesis of distal ulcerative colitis and that butyrate irrigation ameliorates this condition.
Adult↗
[Colorectal carcinoma, a diet-dependent disease. Early signs of an increased risk].
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Biomarkers↗
Effect of starch malabsorption on fecal bile acids and neutral sterols in humans: possible implications for colonic carcinogenesis.
Epidemiological and experimental studies indicate a strong association between an elevated colon cancer risk and increased fecal excretion of secondary bile acids, neutral sterols, and prolonged gastrointestinal transit time. Starch malabsorption, on the other hand, has been reported to be a possible protective factor in colon carcinogenesis. To study the impact of starch malabsorption on these parameters, 12 healthy volunteers consumed a diet rich in starch for two 4-week periods. During a double-blind crossover trial they received the alpha-glucosidase inhibitor acarbose (BAY g 5421) in one of the study periods and placebo in the other. During acarbose treatment stool wet weight increased by 68%, stool dry weight by 57%, and gastrointestinal mean transit time by 30%. Fecal concentrations (mg/g dry weight) of the neutral sterols coprostanol, coprostanone, campesterol, 4-cholesten-3-one, and beta-sitosterol decreased by 36.8, 48.7, 42.1, 34.6, and 39.4%, respectively, under acarbose. Concentrations of the major secondary bile acids, deoxycholic and lithocholic acid, decreased by 59.9 and 52.2%, respectively. In spite of an increased stool weight, also daily excretion (mg/day) of these two bile acids was lower under acarbose (47.9 and 36.6%, respectively) compared to placebo, whereas excretion of the main primary bile acid, cholic acid, rose from 22.58 mg/day to 379.80 mg/day during the acarbose period. The changes in fecal bile acid and neutral sterol excretion found during acarbose treatment may explain a protective effect of starch malabsorption on colon cancer development.
Acarbose↗
Colonic fermentation of potato starch after a freeze-thaw cycle.
To estimate colonic carbohydrate fermentation following a potato meal, 13 healthy volunteers consumed 375 g potatoes containing 60 g starch on three different occasions in random order: (A) potatoes boiled and consumed fresh at 60 degrees C; (B) potatoes boiled, frozen, thawed and consumed at 20 degrees C; and (C) potatoes boiled, frozen, thawed, reheated to 90 degrees C, and consumed at 60 degrees C. End-expiratory breath hydrogen (H2) was measured every 15 min for 10-14 hr with a selective electrochemical cell. The extent of colonic carbohydrate fermentation (AUC = area under the breath H2 concentration vs time curve) in experiment B was significantly higher (+186%, P less than 0.002) than in experiment A. The breath hydrogen AUC in experiment C was higher than in experiment A (+48%, P less than 0.04) but lower than in experiment B (-94%, P less than 0.003). It is suggested that structural alterations of the starch molecule occur during freezing, thawing, and reheating and alter the availability of carbohydrates for fermentation by colonic anaerobes.
Adult↗
Magnetic search coil system for linear detection of three-dimensional angular movements.
The design of a two-dimensional (2D) magnetic field search coil system based on the phase detection principle is described. The system was developed to record horizontal and vertical eye and head movements of small, unrestrained laboratory animals. It is also applicable for measuring three-dimensional (3D) eye and head movements in primates and man. The output is linear over 355 degrees in the horizontal plane and over +/- 60 degrees in the vertical direction. The procedure of recording 3D eye and head movements is discussed.
Animals↗
[Diseases of the large intestine in the aged. Constipation--diverticulosis--tumors--ischemia].
In no other part of the gastrointestinal tract is there such a wide range of incidence of pathological changes and such a marked increase in incidence with increasing age as the colorectum. In view of the increasing numbers of old people in the general population, therefore, gastroenterologists are increasingly being confronted with these diseases. The most important in practical terms are constipation, colonic diverticulosis with its complications, benign and malignant tumors, and the damages to the wall of the colon resulting from deficient perfusion. In the case of geriatric patients, the evaluation of the symptomatology, so important for the diagnosis, can be difficult, since the complaints may be overemphasized owing to anxious self-observation, or, owing to a reduction in cerebral capacity, are not adequately appreciated and reported.
Aged↗