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Proximal Colon (proximal + colon)

Distribution by Scientific Domains

Medical Sciences	85%
Life Sciences	9%

Distribution within Medical Sciences

Gastroenterology & Hepatology	44%
Oncology & Radiotherapy	16%
5 Other Subdomains	24%

Selected Abstracts

ARE GAP JUNCTIONS TRULY INVOLVED IN INHIBITORY NEUROMUSCULAR INTERACTION IN MOUSE PROXIMAL COLON?

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 8 2006
Andrei Sibaev
SUMMARY 1Gap junctions exist between circular muscle cells of the colon and between interstitial cells of Cajal (ICC) in the myenteric plexus of the gastrointestinal tract. They also probably couple intramuscular ICC with smooth muscle cells. Recent functional evidence for this was found in dye-coupling and myoelectrical experiments. 2In the present study, we tested the hypothesis of gap junctions putatively being involved in neuromuscular interaction in mouse colon by using different classes of gap junction blockers. 3Electrical field stimulation of the myenteric plexus elicited tetrodotoxin-sensitive and hexamethonium-independent fast and slow inhibitory junction potentials (fIJP and sIJP, respectively) in circular smooth muscle cells, as evaluated by intracellular recording techniques in impaled smooth muscle cells. Heptanol produced a time-dependent hyperpolarization of the membrane potential (MP) and abolished fIJP and sIJP. Octanol had no effect on the MP and abolished fIJP and sIJP. Carbenoxolone produced a time-dependent depolarization of the MP without any effect on fIJP or sIJP. The connexin 43 mimetic gap junction blocker GAP-27 had no effect on MP, fIJP or sIJP. 4Based on the presently available gap junction blockers we found no evidence that gap junctions are involved in neuromuscular transmission in mouse colon, as suggested by morphological studies. [source]

Densely methylated MLH1 promoter correlates with decreased mRNA expression in sporadic colorectal cancers

GENES, CHROMOSOMES AND CANCER, Issue 1 2002
Taiji Furukawa
It has been reported that MLH1 is silenced by promoter methylation, and that this phenomenon is associated with microsatellite instability (MSI) in sporadic colorectal cancer (CRC). To clarify the significance of MLH1 promoter methylation in sporadic CRC, we examined the correlation between methylation status over the entire promoter region and mRNA expression in cases showing high-frequency MSI (MSI-H). MLH1 promoter methylation was analyzed using the bisulfite modification sequencing in 48 MSI-H cases. We also screened for somatic mutation, loss of heterozygosity, and immunohistochemical staining of MLH1. The results showed that methylation patterns could be subdivided into three types: methylation of more than 80% of the CpG sites analyzed (type 1 methylation), methylation of less than 20% (type 2 methylation), and methylation mainly in the region 500 to 921 bases upstream from the translation start site (type 3 methylation). Of the three types, only type 1 methylation correlated with decreased mRNA expression. The frequency of type 1 methylation was significantly higher in cases involving the proximal colon (66.7%, 18/27) compared to that of the distal colon and rectum (23.8%, 5/21, P = 0.004). Immunohistochemical staining of MSI-H cases showed that decreased MLH1 was found in 77.1% (37/48). Of the cases with decreased MLH1, type 1 methylation was present in 59.5% (22/37). Overall, our data suggested that the type 1 methylation pattern may affect MLH1 mRNA expression, such that the majority of MSI-H cases in sporadic CRC, especially proximal colon cancer, exhibited type 1 methylation. © 2002 Wiley-Liss, Inc. [source]

The changing incidence and sites of colorectal cancer in the Israeli Arab population and their clinical implications

INTERNATIONAL JOURNAL OF CANCER, Issue 1 2007
Paul Rozen
Abstract Israeli Arabs have been at low risk for colorectal cancer (CRC) and had mainly proximal cancer, but increasing CRC is now noted. We examined this trend and CRC site and compared them to the total Jewish population and to the low-risk Jews of Asian-African origin. Israel Cancer Registry CRC data, 1982,2002, for Arabs and Jews was computed by gender, age and site: rectal cancer included recto-sigmoid junction; "right-sided" CRC included the proximal colon up to and also the splenic flexure. During 1982,2002, Arab CRC trends increased significantly in both sexes due to left -sided CRC (women, p = 0.01; men, p = 0.02) and rectal cancers (p = 0.05). Left -sided CRC increased significantly in both men and women aged , 65 years (p = 0.02). Comparing 1982,1984 to 2000,2002, the proportion of right-sided CRC decreased in both genders (p < 0.01) from 39.4 to 27.1% of male CRC, and from 44.8 to 31.3% in females. In general, this pattern of increasing rectal and left-sided CRC had been seen over a decade earlier in Jews of Asian-African origin and then their trend reversed during the last decade. In conclusion, there is a recent trend for left-sided CRC in Israeli Arabs, probably related to their changing life style. These results should influence their cancer preventive lifestyle recommendations, and CRC screening and diagnostic methodologies used. © 2006 Wiley-Liss, Inc. [source]

Raw potato starch and short-chain fructo-oligosaccharides affect the composition and metabolic activity of rat intestinal microbiota differently depending on the caecocolonic segment involved

JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003
G.M. Le Blay
Abstract Aims:In vitro studies have suggested that fructo-oligosaccharides (FOS) and resistant starch (two fermentable non-digestible carbohydrates) display different fermentation kinetics. This study investigated whether these substrates affect the metabolic activity and bacterial composition of the intestinal microflora differently depending on the caecocolonic segment involved. Methods and Results: Eighteen rats were fed a low-fibre diet (Basal) or the same diet containing raw potato starch (RPS) (9%) or short-chain FOS (9%) for 14 days. Changes in wet-content weights, bacterial populations and metabolites were investigated in the caecum, proximal and distal colon and faeces. Both substrates exerted a prebiotic effect compared with the Basal diet. However, FOS increased lactic acid-producing bacteria (LAPB) throughout the caecocolon and in faeces, whereas the effect of RPS was limited to the caecum and proximal colon. As compared with RPS, FOS doubled the pool of caecal fermentation products, while the situation was just the opposite distally. This difference was mainly because of the anatomical distribution of lactate, which accumulated in the caecum with FOS and in the distal colon with RPS. Faeces reflected these impacts only partly, showing the prebiotic effect of FOS and the metabolite increase induced by RPS. Conclusions: This study demonstrates that FOS and RPS exert complementary caecocolonic effects. Significance and Impact of the study: The RPS and FOS combined ingestion could be beneficial by providing health-promoting effects throughout the caecocolon. [source]

Usefulness of virtual colonoscopy in the diagnosis of symptomatic large colonic lipomas

JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 2007
A Koktener
SUMMARY Lipomas of the colon are uncommon tumour of the gastrointestinal tract, but cause diagnostic difficulty when they are symptomatic. We reported two cases of symptomatic, large colonic lipoma. Colonoscopy was incomplete because of the narrowing lumen caused by lipomas. By the help of computed tomography colonography/virtual colonoscopy, colonic lipomas were diagnosed correctly, but also proximal colon was examined. [source]

Investigation of ,2 -adrenoceptor subtype selectivity and organ specificity for bedoradrine (KUR-1246), a novel tocolytic beta-adrenergic receptor stimulant

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2009
Yoshihito Inoue
Abstract Objectives:, The aim of this study was to evaluate the beta-adrenergic receptor (,-AR) selectivity, organ specificity and efficacy of delaying the onset of spontaneous delivery of bedoradrine (KUR-1246), a novel uterine relaxant. Methods:, ,-AR selectivity was evaluated in terms of the amount of cyclic adenosine monophosphate produced by bedoradrine, ritodrine and isoprenaline in Chinese hamster ovary cells expressing human ,1 -, ,2 -AR or ,3 -AR. Inhibition of contractions of the atrium, trachea and proximal colon by bedoradrine were compared with those of the uterus in pregnant rats using an organ bath method. Finally, the delaying effect of bedoradrine on spontaneous labor was evaluated by an in vivo study using term pregnant rats. Results:, EC50 values of bedoradrine for cyclic adenosine monophosphate production in Chinese hamster ovary cells via ,1 -, ,2 - and ,3 -AR were 2400 ± 30, 2.9 ± 0.10 and 363 ± 3 nmol/L, respectively, indicating that bedoradrine had 832- and 126-fold higher selectivity for ,2 -AR than for ,1 - and ,3 -AR. EC50 values of bedoradrine for the uterus, atrium, trachea and proximal colon were 1.01 ± 0.27, 2300 ± 356, 1610 ± 299 and 219 ± 23.5 nmol/L, respectively. Thus, bedoradrine was 2280-, 1590- and 217-fold more specific for the uterus than for the atrium, trachea and proximal colon, respectively. Bedoradrine delayed the spontaneous delivery of 21-day-pregnant rats in a dose-dependent manner. Conclusions:, Bedoradrine is a promising drug for the treatment of preterm labor in obstetrical practice because it has better selectivity for ,2 -AR and specificity for the uterus than currently used agents and may effectively delay spontaneous delivery. [source]

Ethanol Upregulates iNOS Expression in Colon Through Activation of Nuclear Factor-kappa B in Rats

ALCOHOLISM, Issue 1 2010
Chao Wang
Background:, Alcohol inhibits colonic motility but the mechanism is unknown. The goal of this study was to test the possibility that nuclear factor-kappa B (NF-,B) is involved in the upregulation of inducible nitric oxide synthase (iNOS) expression induced by ethanol in colon. Methods:, The isometric contraction of longitudinal muscle strips of proximal colon (LP) was monitored by polygraph. Western blot analysis was used to measure the amount of iNOS and I-,B in the cytoplasm and P65 in the nucleus. Immunohistochemistry was applied to locate iNOS in colon. Results:, Ethanol (87mM) inhibited the contraction of LP. Pretreatment of S-methylisothioure (SMT) (1 mM), a specific iNOS inhibitor, Pyrrolidine dithiocarbamate (PDTC) (10 mM) and BAY11-7082(10 mM), specific inhibitors of NF-,B significantly reversed the inhibitory effect of ethanol on LP contraction. Ethanol increased the amount of iNOS and content of NO in colon, and these effects were attenuated by pretreatment of PDTC. Following ethanol administration, the amount of I-,B in the cytoplasm decreased, but that of P65, the subunit of NF-,B in the nucleus, increased. The iNOS was located in the cell body of myenteric plexus in colon. Conclusion:, Ethanol inhibited the contraction of LP in colon mainly through activation of NF-,B, the subsequent upregulation of iNOS expression and increase of NO release in myenteric plexus. [source]

Dietary poorly absorbed, short-chain carbohydrates increase delivery of water and fermentable substrates to the proximal colon

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2010
J. S. BARRETT
Summary Background, Functional gut symptoms are induced by inclusion and reduced by dietary restriction of poorly absorbed short-chain carbohydrates (FODMAPs), but the mechanisms of action remain untested. Aims, To determine the effect of dietary FODMAPs on the content of water and fermentable substrates of ileal effluent. Methods, Twelve ileostomates without evidence of small intestinal disease undertook two 4-day dietary periods, comprising diets differing only in FODMAP content in a randomized, cross-over, single-blinded intervention study. Daytime (14 h) ileal effluent was collected on day four of each diet. Patients rated effluent volume and consistency on a 10-cm visual analogue scale. The FODMAP content of the diet and effluent was measured. Results, Ingested FODMAPs of 32% (range 6,73%) was recovered in the high FODMAP diet effluent. Effluent collection weight increased by a mean of 22% (95% CI, 5,39), water content by 20% (2,38%) and dry weight by 24% (4,43%) with the high compared to low FODMAP diet arm. Output increased by 95 (28,161) mL. Volunteers perceived effluent consistency was thicker (95% CI, 0.6,1.9) with the low FODMAP diet than with the high FODMAP diet (3.5,6.1; P = 0.006). Conclusions, These data support the hypothetical mechanism; FODMAPs increase delivery of water and fermentable substrates to the proximal colon. [source]

Long-term effects on the digestive tract of feeding large amounts of resistant starch: A study in pigs

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2007
Daniel Martínez-Puig
Abstract The present study aimed to assess the digestive consequences of the long-term intake of two starches providing different amounts of resistant starch. Growing pigs were used as the animal model and meal-fed for 14 weeks on a diet containing a high amount of either raw potato starch (RPS) or corn starch (CS). Digestive adaptation was chronologically evaluated by measuring organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and starch digestibility. After 97 days, whole-tract digestibility of OM, CP and NDF was lower for RPS- compared to CS-fed pigs, whereas no differences were observed in faecal starch digestibility. In contrast, starch digestibility was reduced in the proximal compartments (ileum, caecum and proximal colon) of animals fed the RPS diet. The concentration of short-chain fatty acids (SCFAs; P < 0.05), and purine bases (PBs; P < 0.01) was also higher in distal colon and rectum of animals fed the RPS diet. Changes in bacterial community structure (dendogram analyses) were seen in the rectum. Biodiversity tends to increase more in RPS compared to CS fed animals (34.1 vs. 28.8; P = 0.07). Among SCFAs, the proportion of butyrate was two-fold higher in proximal colon digesta of RPS compared to CS fed pigs (0.20 vs. 0.11; P < 0.05). Increased butyrate formation in the colon reduced the number of apoptosis per crypt in the proximal colonic mucosa (0.38 vs. 0.62; P < 0.05). RPS fermentation reduced indices associated with damage to intestinal epithelial cells, such as crypt cell hyperproliferation and magnesium excretion. Long-term ingestion of RPS induces pronounced changes of the digestive tract and their microflora, modifying mineral absorption and colonic morphology for which health benefits are likely to be associated. Copyright © 2007 Society of Chemical Industry [source]

The utility of flexible sigmoidoscopy after a computerized tomographic colonography revealing only rectosigmoid lesions

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2008
P. E. YOUNG
Summary Background, Identifying polyps by computerized tomographic colonography typically prompts colonoscopy, increasing its cost, risk and inconvenience. Many polyps are confined to the rectosigmoid and theoretically amenable to resection via flexible sigmoidoscopy. Aim, To determine the prevalence of advanced proximal colonic neoplasia when computerized tomographic colonography reveals only rectosigmoid polyps, and characterize the yield of polypectomy via flexible sigmoidoscopy in such patients. Methods, Subjects underwent computerized tomographic colonography and colonoscopy with segmental unblinding. Patients with only rectosigmoid findings by computerized tomographic colonography were identified retrospectively. Flexible sigmoidoscopy findings were estimated by including lesions distal to the descending/sigmoid colon junction during colonoscopy. Proximal lesions were also reviewed. Advanced lesions were defined as: adenocarcinoma, tubular adenoma >1 cm, ,3 tubular adenomas, tubulovillous histology or high-grade dysplasia. Results, By computerized tomographic colonography, 15% (203 of 1372) had only rectosigmoid polyps. Concomitant lesions in the proximal colon were seen in 32% (64 of 203) during colonoscopy. Advanced proximal neoplasia occurred in 2% (three of 203) with only rectosigmoid polyps on computerized tomographic colonography. Conclusions, Using flexible sigmoidoscopy to follow-up computerized tomographic colonography demonstrating only rectosigmoid polyps would eliminate 15% of subsequent colonoscopies. This strategy carries a small risk of missed proximal advanced neoplasia. This miss rate appears comparable to that of colonoscopy alone. Further study on the cost-effectiveness of this approach is warranted. [source]

Differential stress-induced alterations of colonic corticotropin-releasing factor receptors in the Wistar Kyoto rat

NEUROGASTROENTEROLOGY & MOTILITY, Issue 3 2010
D. O'malley
Abstract Background, A growing body of data implicates increased life stresses with the initiation, persistence and severity of symptoms associated with functional gut disorders such as irritable bowel syndrome (IBS). Activation of central and peripheral corticotropin-releasing factor (CRF) receptors is key to stress-induced changes in gastrointestinal (GI) function. Methods, This study utilised immunofluorescent and Western blotting techniques to investigate colonic expression of CRF receptors in stress-sensitive Wistar Kyoto (WKY) and control Sprague Dawley (SD) rats. Key Results, No intra-strain differences were observed in the numbers of colonic CRFR1 and CRFR2 positive cells. Protein expression of functional CRFR1 was found to be comparable in control proximal and distal colon samples. Sham levels of CRFR1 were also similar in the proximal colon but significantly higher in WKY distal colons (SD: 0.38 ± 0.14, WKY: 2.06 ± 0.52, P < 0.01). Control levels of functional CRFR2 were similar between strains but sham WKYs samples had increased CRFR2 in both the proximal (SD: 0.88 ± 0.21, WKY: 1.8 ± 0.18, P < 0.001) and distal (SD: 0.18 ± 0.08, WKY: 0.94 ± 0.32, P < 0.05) regions. Exposure to open field (OF) and colorectal distension (CRD) stressors induced decreased protein expression of CRFR1 in SD proximal colons, an effect that was blunted in WKYs. CRD stimulated decreased expression of CRFR2 in WKY rats alone. Distally, CRFR1 is decreased in WKY rats following CRD but not OF stress without any apparent changes in SD rats. Conclusions & Inferences, This study demonstrates that psychological and physical stressors alter colonic CRF receptor expression and further support a role for local colonic CRF signalling in stress-induced changes in GI function. [source]

The effect of mosapride citrate on proximal and distal colonic motor function in the guinea-pig in vitro

NEUROGASTROENTEROLOGY & MOTILITY, Issue 2 2008
H. S. Kim
Abstract, Mosapride citrate (mosapride), a substituted benzamide, is a selective 5-HT4 receptor agonist, and is known to have prokinetic properties on the stomach. However, it is unclear whether mosapride also has a prokinetic effect on the colon. We previously found that mosapride significantly shortened colonic transit time in the guinea-pig, an animal with a distribution of colonic 5-HT4 receptors similar to that of a human. So, we aimed to separately evaluate the effect of mosapride on proximal and distal colonic motor function in the guinea-pig. Proximal (approximately 8 cm from the ileocolic junction) and distal colon (approximately 8 cm from the anus) were removed. Both ends of the colon were connected to a chamber containing a Krebs-Henseleit solution. To measure colonic transit time, artificial faeces were inserted into the oral side of the lumen and moved towards the anal side by intraluminal perfusion via a peristaltic pump. A total of 6 cm of transit was observed and time was measured in 2 cm increments. A tissue bath study, using electrical stimulation, was performed to estimate the contractile activity of the circular musculature of the colon. Immunohistochemical staining for 5-HT4 receptors was performed in the myenteric plexus and circular muscle in both proximal and distal colon, and the stained area was measured using a microscope and computer software. Mosapride enhanced contraction at 10,9 to 10,7 mol L,1, coinciding with rapid transit both in proximal and distal colon. This pattern was more prominent in proximal colon. At the high dose (10,6 mol L,1) mosapride had little or no effect on colonic contraction. This stimulatory effect was attenuated by GR113808, atropine and tetrodotoxin. In the myenteric plexus, the density of 5-HT4 receptors was significantly greater in the proximal colon than in the distal colon, but in circular muscle the density was greater in the distal colon. Thus, mosapride accelerates transit through increased contraction in the proximal colon more than distal colon. The different distribution of neuronal and muscular 5-HT4 receptors may support these findings. Therefore, mosapride may be a useful alternative to tegaserod and cisapride for constipation. [source]

Nitric oxide mediates the inhibitory effect of ethanol on the motility of isolated longitudinal muscle of proximal colon in rats

NEUROGASTROENTEROLOGY & MOTILITY, Issue 6 2007
S. L. Wang
Abstract, The aim of the present study was to investigate the effect of ethanol on colon motility in rats and to test the possibility that nitric oxide (NO) mediates this effect. Proximal colon longitudinal muscle strips (LM) (8 × 3 mm) cut parallel to the longitudinal muscle fibres of the colon were isolated and mounted in an organ bath. Ethanol (0.57, 0.87 and 1.30 mmol L,1) dose-dependently inhibited the motility of LM. Longitudinal muscle strips from female rats were more sensitive to the inhibitory effect of ethanol than that from male rats. L-NAME (N -nitro- l -arginine methyl ester) (100 ,mol L,1), AG (aminoguanidine) (10 ,mol L,1), ODQ (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one) (10 ,mol L,1) and PTIO (2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide) (200 ,mol L,1) partly blocked the inhibitory effect of ethanol on LM. Pretreatment with L-NAME, AG, ODQ and PTIO abolished the sex difference of the inhibitory effect of ethanol on LM. Tetrodotoxin (TTX) (10 ,mol L,1) partly blocked the inhibitory effect but did not influence the sex difference. The relaxation of LM induced by SNP (sodium nitroprusside) (0.1,10 ,mol L,1) in female rats was greater than that in male rats. In conclusion, ethanol inhibited the colon motility in vitro. This inhibitory effect on LM was mediated by NO through the iNOS , NO , cGMP pathway. [source]

Evidence for functional NK1 -tachykinin receptors on motor neurones supplying the circular muscle of guinea-pig small and large intestine

NEUROGASTROENTEROLOGY & MOTILITY, Issue 4 2000
Bian
The guinea-pig intestine was investigated to determine which neurones are excited via NK1 receptors. The specific NK1 receptor agonists [Sar9, Met(O2)11]-SP and septide contracted the circular muscle of all regions via a tetrodotoxin (TTX)-insensitive mechanism. In the proximal colon, they also evoked a TTX-sensitive relaxation; in the distal colon, the contractions were larger when nerve impulses were blocked with TTX, indicating that the agonists excited inhibitory motor neurones. In the duodenum and ileum, TTX reduced agonist-evoked contractions indicating that excitatory motor neurones were activated. In the presence of indomethacin, TTX enhanced contractions of ileal circular muscle evoked by these agonists suggesting that NK1 receptors were on inhibitory motor neurones. Blockade of nitric oxide synthase (NOS) enhanced NK1 receptor agonist evoked contractions of duodenal circular muscle, indicating that the agonists excite inhibitory motor neurones in duodenum. Neurones immunoreactive for NK1 receptors were studied in the duodenum and distal colon. As reported previously for the ileum,1 some neurones were immunoreactive for NOS and had Dogiel type I morphology; features characteristic of inhibitory motor neurones. In conclusion, there are functional NK1 receptors on excitatory and inhibitory motor neurones in the guinea-pig small intestine and on inhibitory motor neurones in the colon. [source]

The comparative study digestion and metabolism of nitrogen and purine derivatives in male, Thai, Swamp buffalo and Thai, Brahman cattle

ANIMAL SCIENCE JOURNAL, Issue 2 2009
Thongsuk JETANA
ABSTRACT Studies on in vivo digestion, rates of passages, metabolism of nitrogen, urinary purine derivative excretion and blood metabolites were carried out in Thai Brahman cattle and Thai swamp buffaloes (16 months old). The animals were fed mixed diets based on pineapple (Ananas comusus) waste silage containing urea-N (NPN) and true protein from a concentrate (TP). The Brahman cattle (310 ± 15 kg) were heavier than the swamp buffaloes (195 ± 9.4 kg) and had higher dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) intakes when compared on the basis of their metabolic body weight (BW0.75), but these intakes did not differ significantly when the diets of each animal species were compared. The total tract, apparent digestibilities of dry matter (DM) and organic matter (OM) were not significantly different between the animal species when comparing the two types of diets. The NDF digestibility was significantly (P < 0.01) decreased in both animal species when fed the TP diet, but was significantly (P < 0.01) greater in cattle than in swamp buffaloes. The passage rate digesta k1 (P < 0.01) and the passage rate digesta k2 (through the caecum and proximal colon) (P < 0.03) were significantly slower, and the total mean retention time (TMRT) (P < 0.01) was significantly longer in swamp buffaloes when compared to Brahman cattle, but the transit time (TT) showed no difference (P = 0.07) between the animal species or the diets. The N intakes were not different in both animal species and diets, but urine-N was greater (P < 0.05) in Brahman cattle than that in swamp buffaloes. Urine N and digestibility of N were significantly (P < 0.04) higher in animals fed the NPN diet than those fed the TP diet. Urinary purine derivatives (PD) and the creatinine (Cr) excretion of swamp buffaloes were significantly (P < 0.01) lower than those in Brahman cattle. Plasma urea-N (BUN) concentration was significantly (P < 0.01) higher in swamp buffaloes than that in Brahman cattle, but plasma glucose and insulin concentrations were significantly (P < 0.01) higher in Brahman cattle than in swamp buffaloes. The concentrations of non-esterified fatty acids (NEFA) were not significantly (P > 0.05) different in animals fed different diets. The present study demonstrated that Brahman cattle were better in fiber digestibility than swamp buffaloes at utilizing pineapple waste silage with both N sources. [source]

Muir,Torre syndrome: Diagnostic and screening guidelines

AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 4 2006
Brad Jones
SUMMARY A 65-year-old man presented with a history of multiple skin coloured papules on his face that were asymptomatic. He had an adenocarcinoma resected from his proximal colon 12 years prior to presentation as well as a family history of colon cancer on the maternal side. Diagnostic biopsies showed the lesions to be sebaceous adenomas and epitheliomas and the diagnosis of Muir,Torre syndrome was made. The sebaceous tumour tissue showed microsatellite instability and immunohistochemical staining indicated diminished expression in the DNA mismatch,repair protein complex MSH2/MSH6. Genetic analysis showed a germline mutation in the MSH2 gene confirming the diagnosis of Muir,Torre syndrome. The patient and his first-degree relatives have been referred for genetic counselling and screening. We review the diagnostic criteria in this syndrome and review the recommended screening guidelines. [source]

2-Phenylmelatonin: A Partial Agonist at Enteric Melatonin Receptors

BASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2000
Maria Grazia Santagostino-Barbone
The effect of the melatonin receptor ligand, 2-phenylmelatonin, has been assessed in isolated strips of the guinea-pig proximal colon. 2-Phenylmelatonin (0.01 nM-1 ,M) caused a concentration-dependent contractile response. The potency value (,log EC50) was 9.3±1.0. The maximum effect was 25±4% of that elicited by the maximally effective concentration (0.3 ,M) of 5-HT and 43±3% of that by the maximally effective concentration (10 ,M) of melatonin. When used as an antagonist, 2-phenylmelatonin (0.01 nM and 0.1 nM) concentration-dependently inhibited melatonin-induced contractions with depression of the maximum response by 25% and 54%, respectively. Higher (1 nM) 2-phenylmelatonin concentrations failed to antagonize melatonin-induced response. Prazosin (0.3 ,M), a selective antagonist of melatonin MT3 sites, antagonized melatonin-induced contractions to an extent similar to that induced by 0.01 nM 2-phenylmelatonin (with 30% reduction of the maximum effect to melatonin). The combination of 0.3 ,M prazosin and 0.01 nM 2-phenylmelatonin caused antagonism similar in extent to that caused by each individual antagonist. 2-Phenylmelatonin at subnanomolar concentrations behaves as an antagonist of melatonin-induced contractile responses while at nanomolar/micromolar concentrations it behaves as a weak contractile agonist. [source]

Calcitonin gene-related peptide facilitates serotonin release from guinea-pig colonic mucosa via myenteric neurons and tachykinin NK2/NK3 receptors

BRITISH JOURNAL OF PHARMACOLOGY, Issue 3 2004
Shu-ichi Kojima
The ability of calcitonin gene-related peptide (CGRP), to alter the outflow of 5-hydroxytryptamine (5-HT) from the guinea-pig proximal colon, was evaluated using three different isolated preparations: whole colon, mucosa-free muscle layer and submucosa/mucosa preparations. In the presence of the monoamine oxidase A inhibitor, clorgyline, CGRP elicited a concentration-dependent increase in 5-HT outflow from the whole colon, but not from mucosa-free muscle layer preparations. The CGRP-evoked 5-HT outflow was sensitive to tetrodotoxin (TTX) or hexamethonium, but was not detectable in submucosa/mucosa preparations. HCGRP8,37 (3 ,M) inhibited the submaximal effect of CGRP on the 5-HT outflow. [Cys(ACM)2,7]hCGRP had a slight stimulant influence on the 5-HT outflow. The selective NK2 and NK3 receptor antagonists, SR48968 or SR142801, respectively, prevented the enhancing effect of CGRP. By contrast, a selective NK1 receptor antagonist L703606, failed to block the effect of CGRP. The enhancing effect of CGRP was mimicked by the NK2 receptor agonist [, -Ala8]-neurokinin A (NKA)4,10 and the NK3 receptor agonist senktide. The effect of [, -Ala8]-NKA4,10 on the 5-HT outflow was unaffected by TTX, while the effect of senktide was prevented by TTX, hexamethonium or SR48968. The present data also demonstrated a synergistic action of the NK2 and NK3 receptor agonists on the CGRP-evoked 5-HT outflow. We concluded that CGRP facilitates 5-HT release from the guinea-pig colonic mucosa through an action on myenteric neurons and that this effect is mediated by endogenously released tachykinins, acting via tachykinin NK2/NK3 receptors in cascade. British Journal of Pharmacology (2004) 141, 385,390. doi:10.1038/sj.bjp.0705624 [source]

Association between genetic polymorphisms of the base excision repair gene MUTYH and increased colorectal cancer risk in a Japanese population

CANCER SCIENCE, Issue 2 2008
Hong Tao
The MUTYH gene encodes a DNA glycosylase that can initiate the base excision repair pathway and prevent G:C > T:A transversion by excising adenine mispaired with 8-hydroxyguanine. Biallelic germline mutations of MUTYH have been shown to predict familial and sporadic multiple colorectal adenomas and carcinomas, however, whether there is an association between single nucleotide polymorphisms (SNPs) of MUTYH and sporadic colorectal cancer (CRC) risk has remained unclear. In this study we investigated four MUTYH SNPs, IVS1+11C > T, IVS6+35G > A, IVS10,2A > G, and 972G > C (Gln324His), for an association with increased CRC risk in a population-based series of 685 CRC patients and 778 control subjects from Kyushu, Japan. A statistically significant association was demonstrated between IVS1+11T and increased CRC risk (odds ratio [OR]: 1.43; 95% confidence interval [CI]: 1.012,2.030; P = 0.042) and one of the five haplotypes based on the four SNPs, the IVS1+11T , IVS6+35G , IVS10,2A , 972C (TGAC) haplotype containing IVS1+11T, was demonstrated to be associated with increased CRC risk (OR, 1.43; 95% CI, 1.005,2.029; P = 0.046). Subsite-specific analysis showed that the TGAC haplotype was statistically significantly (P = 0.013) associated with an increased risk of distal colon, but not proximal colon or rectal cancer. Furthermore, IVS1+11C > T was found to be in complete linkage disequilibrium with ,280G > A and 1389G > C (Thr463Thr). The results indicated that Japanese individuals with , 280A/IVS1+11T/1389C genotypes or the TGAC haplotype are susceptible to CRC. (Cancer Sci 2008; 99: 355,360) [source]