The parasympathetic and sensory innervation of the proximal and distal colon in male mice.

Introduction: The distributions of extrinsic neurons innervating the colon show differences in experimental animals from humans, including the vagal and spinal parasympathetic innervation to the distal colon. The neuroanatomical tracing to the mouse proximal colon has not been studied in details. This study aimed to trace the locations of extrinsic neurons projecting to the mouse proximal colon compared to the distal colon using dual retrograde tracing. Methods: The parasympathetic and sensory neurons projecting to colon were assessed using Cholera Toxin subunit B conjugated to Alexa-Fluor 488 or 555 injected in the proximal and distal colon of the same mice. Results: Retrograde tracing from the proximal and distal colon labeled neurons in the dorsal motor nucleus of the vagus (DMV) and the nodose ganglia, while the tracing from the distal colon did not label the parasympathetic neurons in the lumbosacral spinal cord at L6-S1. Neurons in the pelvic ganglia which were cholinergic projected to the distal colon. There were more neurons in the DMV and nodose ganglia projecting to the proximal than distal colon. The right nodose ganglion had a higher number of neurons than the left ganglion innervating the proximal colon. In the dorsal root ganglia (DRG), the highest number of neurons traced from the distal colon were at L6, and those from the proximal colon at T12. DRG neurons projected closely to the cholinergic neurons in the intermediolateral column of L6 spinal cord. Small percentages of neurons with dual projections to both the proximal and distal colon existed in the DMV, nodose ganglia and DRG. We also observed long projecting neurons traced from the caudal distal colon to the transverse and proximal colon, some of which were calbindin immunoreactive, while there were no retrogradely labeled neurons traced from the proximal to distal colon. Discussion: These data demonstrated that the vagal motor and motor and sensory neurons innervate both the proximal and distal colon in mice, and the autonomic neurons in the intermediate zone of the lumbosacral spinal cord do not project directly to the mouse colon, which differs from that in humans.

Laparoscopic-assisted distal colon excision and proximal colon pull-through anorectoplasty for anorectal malformation.

Purpose: During the second stage surgery for anorectal malformations (ARM), patients whose distal intestine of the colostomy is particularly short underwent laparoscopic-assisted distal colon excision and proximal colon pull-through anorectoplasty (PCPARP). This study aimed to discuss the outcomes of PCPARP after colostomy in patients with ARM. Methods: This is a single-center propensity score-matched (PSM) study which was retrospectively initiated patients with intermediate- or high-type ARM who underwent laparoscopic surgery from June 2007 to December 2018. These patients were divided into PCPARP group and conventional laparoscopic-assisted anorectoplasty (LAARP) group according to specific surgical methods. The general data, surgical data, postoperative complications, and functional results were evaluated. Results: In total, 216 patients were included in this study: 190 (88.0%) undergoing LAARP approach and 26 (12.0%) undergoing PCPARP approach. After PSM, two well-balanced groups of 26 patients were analyzed and showed the postoperative complications (P = 0.126) and bowel function (P = 0.809) were similiar between the two groups. Conclusions: The curative effect of PCPARP after colostomy is similar to that of classic LAARP surgery, which can be used for ARM patients with a very short and abnormal distal intestine of the stoma.

The preventive and therapeutic consumption of meat enriched with carob fruit extract, rich in phenolic compounds, improves colonic antioxidant status in late-stage T2DM rats.

Oxidative stress is prevalent in Type 2 Diabetes Mellitus (T2DM) and has been associated with high meat consumption. Carob Fruit Extract (CFE) contains phenolic compounds, making it a suitable functional ingredient. Current study aims to evaluate the effect of CFE-enriched meat (CFE-meat) consumption on the antioxidant status of proximal and distal colon, and its relationship with fecal phenolic compounds in late-stage T2DM rats. Three groups of eight rats were studied: 1) D, fed control-meat; 2) ED, fed CFE-meat since the beginning of the study; 3) DE, fed CFE-meat after confirming T2DM. CFE-meat consumption reduces colonic oxidative stress mainly in the proximal section and helps to ameliorate glutathione metabolism and antioxidant score. Difference between ED and DE groups were associated with colon homeostasis and T2DM progression suggesting greater fermentation but lower absorption in the DE group. CFE appears as a promising tool to improve the antioxidant status observed in late-stage T2DM.

Tannic acid delaying metabolism of resistant starch by gut microbiota during in vitro human fecal fermentation.

This work investigated the effect of tannic acid on the fermentation rate of resistant starch. It was found that 1.0 and 1.5 µmol/L tannic acid decreased the rate of producing gas and short-chain fatty acids (SCFAs) from fermentation of resistant starch, and 1.5 µmol/mL tannic acid had a more profound effect, which confirmed that tannic acid delayed the metabolism of resistant starch. Moreover, tannic acid significantly inhibited the α-amylase activity during fermentation. On the other hand, tannic acid delayed the enrichment of some starch-degrading bacteria. Besides, fermentation of the resistant starch/tannic acid mixtures resulted in more SCFAs, particularly butyrate, and higher abundance of beneficial bacteria, including Bifidobacterium, Faecalibacterium, Blautia and Dorea, than fermentation of resistant starch after 48 h. Thus, it was inferred that tannic acid could delay the metabolism of resistant starch, which was due to its inhibitory effect on the α-amylase activity and regulatory effect on gut microbiota.

Methods to mitigate Escherichia coli blooms in human ex vivo colon model experiments using the high throughput micro-Matrix bioreactor fermentation system.

Ex vivo colon model experiments are frequently employed as a means to assess the gut microbiome modulating potential of different foods, food ingredients and dietary supplements. A number of useful models already exist; however, they tend to be relatively low in terms of throughput (3-4 samples per experiment) with a long experiment duration of one to a number of weeks. Therefore, a need for a high-throughput system with a short duration time is required to enable screening of large numbers of samples. Therefore, we report here on the development of a system based on the Applikon micro-Matrix bioreactor which has the capacity to run 24 samples with an experiment duration of 48 h. However, Escherichia coli blooms are a common problem encountered in this model. Here, we describe the factors that contribute to such blooms and provide approaches to address them, providing:•Step by step optimisation of processes involved in conducting ex vivo distal colon experiments using the micro-Matrix bioreactor fermentation platform•Recommended steps for users on how to attenuate E. coli blooms in such ex vivo colon model experiments.

Influencing factors for inadequate bowel preparation of colonoscopy of different colonic segments / 中华消化内镜杂志

Objective:To investigate the influencing factors for inadequate bowel preparation of colonoscopy.Methods:A total of 677 patients who underwent colonoscopy at Peking Union Medical College Hospital from December 2021 to January 2023 were recruited, and all patients underwent standardized bowel preparation by using 3 L polyglycol electrolyte powder with fractional dose. The quality of bowel preparation was assessed by Boston bowel preparation scale, and the influencing factors for inadequate bowel preparation were analyzed by logistic regression analysis.Results:The rate of inadequate bowel preparation was 31.5% (213/677). Among the patients with inadequate bowel preparation, 85.4% (182/213) inadequate bowel preparation was only in proximal colon, 14.1% (30/213) was in both proximal and distal colon, and 0.5% (1/213) was only in distal colon. Inadequate bowel preparation in distal colon and total colon were combined into inadequate bowel preparation in distal colon. The results of logistic regression analysis showed that inadequate bowel preparation in proximal colon was more likely to occur in men ( P=0.001, OR=2.253, 95% CI: 1.399-3.629), outpatients ( P<0.001, OR=4.175, 95% CI: 2.410-7.231), those with no family history of colorectal cancer ( P=0.001, OR=2.117, 95% CI: 1.365-3.284), and diagnostic colonoscopy ( P=0.003, OR=1.978, 95% CI: 1.261-3.102). And spinal disease ( P=0.044, OR=7.430, 95% CI: 1.051-52.511), outpatients ( P<0.001, OR=135.577, 95% CI: 29.135-630.883),non-compliance of dietary requirements ( P=0.006, OR=4.772, 95% CI: 1.576-14.453), adverse reaction during bowel preparation ( P=0.015, OR=4.341, 95% CI: 1.329-14.179), no family history of colorectal cancer ( P=0.003, OR=7.110, 95% CI: 1.912-26.438), and poor last stool character ( P=0.001, OR=25.922, 95% CI: 3.779-177.832) were risk factors for inadequate bowel preparation in distal colon. Conclusions:The inadequate bowel preparation of colonoscopy mainly occurs in proximal colon, and the risk factors for the inadequate bowel preparation vary in different colonic segments. Therefore, the specific interventions should be performed according to the character of different colon segments to improve the quality of bowel preparation.

Clinical application of opportunistic screening for colorectal cancer / 中国内镜杂志

Objective To explore the clinical application of opportunistic screening(OS)for colorectal cancer in order to provide a basis for further improving the screening process and improving screening efficiency.Methods Clinical data of 3 398 patients with positive OS for colorectal cancer who completed total colonoscopy from January 2019 to December 2020 were retrospectively analyzed.After completion of the high risk factor questionnaire(HRFQ)and fecal immunochemical test(FIT),colonoscopy was recommended for patients who tested positive for either of the two screening methods.The age,sex,lesion detection and lesion location of the patients were counted,and the detection rate of colorectal tumors by different screening methods was compared according to the preliminary screening results.Results Among the 3 398 subjects,the detection rate of advanced adenoma and colorectal cancer in HRFQ(-)FIT(+)group were higher than that in HRFQ(+)FIT(-)group,there were significant differences between the two groups(P＜0.05).The detection rate of non-advanced adenoma in HRFQ(-)FIT(+)group was lower than that in HRFQ(+)FIT(+)group,there was significant difference between the two groups(P＜0.05).The sensitivity of FIT to colorectal tumors was generally better than that of HRFQ,and the sensitivity of FIT to distal colorectal tumors was higher than that of proximal colorectal tumors,there were significant differences between the two groups(P＜0.05).Conclusion The combination of HRFQ and FIT can screen more high-risk groups than FIT or HRFQ alone,thus detect more colorectal tumors,effectively improve the 5-year survival rate through timely endoscopic treatment or surgical resection,and ultimately reduce the morbidity and mortality of colorectal cancer in the population.

Findings in the distal and proximal colon in colonoscopy screening after positive FIT and related pre-procedure factors

Background: colonoscopy is the gold standard method forthe early diagnosis and prevention of colorectal cancer(CRC). Screening programs include immune determinationof blood in feces. Regardless of the method used, proximalcolon lesions appear to be detected less frequently.Objective: to analyze the characteristics of proximal anddistal lesions and possible predisposing factors.Methods: a cross-sectional study was performed of 692patients from the CRC screening program with fecal immunological test (FIT) ≥ 100 ngHb/ml (October 2017-October2018). The right colon was examined twice as patients wereparticipating in a randomized clinical trial to re-evaluatethe right colon by forward-viewing endoscope or proximalretroflexion. The adenoma detection rate (ADR), advancedneoplasia (AN) and CRC in the proximal and distal colon,histological and morphological characteristics in each section were analyzed.Results: in the study, 52.9 % of the patients were male, witha mean age of 59.5 years (standard deviation [SD]: 7.6);1,490 polyps were found and the ADR was 57.7 % (distal42 % and proximal 37 %). Detection rates were 45.8 % forAN, 40.9 % for advanced adenomas, 5.2 % for advancedsessile serrated lesions (SSL) and CRC was diagnosed in4.8 % of patients. Males had more AN than females. Themean age of patients with AN was significantly higher. ANwere associated with smoking and alcohol consumption (p = 0.0001). Globally, FIT levels were higher in patientswith AN (p = 0.003). Sixty-six per cent of cancers were distally located and 61.3 % of CRC were diagnosed in the earlystages.Conclusions: in an average-risk asymptomatic populationundergoing colonoscopy after positive FIT, AN were morecommon in the distal colon in males, older patients, smokers and those with alcohol intake. (AU)

The ColonView (CV) Quick Test for Fecal Occult Blood Shows Significantly Higher Diagnostic Accuracy in Detecting Distal than Proximal Colorectal Cancer.

AIM: The present study compared the accuracy of ColonView (CV) quick test in detecting proximal versus distal colorectal cancer (CRC). A traditional guaiac-based fecal occult blood test (gFOBT) (Hemoccult SENSA) was used as a reference. PATIENTS AND METHODS: A cohort of 368 colonoscopy-referral patients were asked to collect 3 consecutive fecal samples, to be analyzed by both assays (CV, SENSA). Receiver operating characteristic (ROC) analysis was used to find the optimal cut-off values for both Hb and Hb/Hp of the CV test. Summary hierarchical ROC (HSROC) curves were used to visualize the pooled overall accuracy of visually analysed (VA) and automatically analyzed (AA) reading modes in proximal and distal CRC detection. RESULTS: The overall specificity (Sp) of the AA reading mode for the proximal CRC and distal CRC endpoint was 73% and 76%, respectively. For proximal CRC, the two most sensitive AA tests showed 90% sensitivity (Se), while for distal CRC, the two most sensitive AA tests showed 100% Se. In the HSROC analysis, the AUC values were as follows: i) VA in proximal CRC: 0.765, ii) AA in proximal CRC: 0.878, iii) VA in distal CRC: 0.955 and iv) AA in distal CRC: 0.961. In roccomp analysis, AUC values were significantly different in: VA vs. AA in proximal CRC p=0.009; VA in proximal vs. VA in distal CRC p<0.0001; VA in proximal vs. AA in distal CRC p<0.0001; AA in proximal vs. VA in distal CRC p=0.021; AA in proximal CRC vs. AA in distal CRC p=0.006. CONCLUSION: The applicability of the CV test (a new-generation FIT) in CRC screening was confirmed. The AA reading was superior to VA (or SENSA) in its diagnostic accuracy in detecting proximal CRC patients. Distal CRCs were more accurately detected than proximal CRCs by both reading modes.

An oxidation resistant pediocin PA-1 derivative and penocin A display effective anti-Listeria activity in a model human gut environment.

Pediocin PA-1 is a class IIa bacteriocin that is particularly effective against the foodborne pathogen Listeria monocytogenes. The loss of activity of PA-1 pediocin due to methionine oxidation is one of the challenges that limit the wider application of the bacteriocin. In this study, we heterologously expressed an oxidation resistant form of pediocin PA-1, i.e., pediocin M31L, and compared its activity to that of native pediocin PA-1 and to penocin A, a pediocin-like bacteriocin that displays a narrower antimicrobial spectrum. Minimal inhibitory concentration assays revealed that pediocin M31L was as effective as PA-1 and more effective than synthetic penocin A against Listeria with negligible activity against a range of obligate anaerobic commensal gut bacterial species. The anti-Listeria activity of these pediocins was also assessed in a simulated human distal colon model assay using the L. monocytogenes, spiked at 6.5 ± 0.13 Log CFU/mL, as a bioindicator. At 24 h, pediocin M31L and penocin A (2.6 µM) reduced Listeria counts to 3.5 ± 0.4 and 3.64 ± 0.62 Log CFU/mL, respectively, whereas Listeria counts were considerably higher, i.e. 7.75 ± 0.43 Log CFU/mL, in the non-bacteriocin-containing control. Ultimately, it was established that synthetic penocin A and the stable pediocin M31L derivative, heterologously produced, display effective anti-Listeria activity in a human gut environment.

Effects of a P2X7 receptor antagonist on myenteric neurons in the distal colon of an experimental rat model of ulcerative colitis.

Inflammatory bowel diseases (IBDs) are chronic diseases of the gastrointestinal tract that include ulcerative colitis and Crohn's disease and affect enteric neurons. Research has shown that Brilliant Blue G (BBG), a P2X7 receptor antagonist, restores enteric neurons following ischemia and reperfusion. This study aimed to evaluate the effect of BBG on myenteric neurons of the distal colon in an experimental rat model of ulcerative colitis. Colitis was induced by injection of 2,4,6-trinitrobenzene sulfonic acid (TNBS) into the large intestine. BBG was administered 1 h after colitis induction and for five consecutive days thereafter. Distal colons were collected 24 h or 7 days after TNBS injection. The animals were divided into 24-h and 7-day sham (vehicle injection rather than colitis induction), 24-h colitis, 24-h BBG, 7-day colitis and 7-day BBG groups. The disease activity index (DAI), neuronal density and profile of neuronal nitric oxide synthase (nNOS)-, choline acetyltransferase (ChAT)- and P2X7 receptor-immunoreactive enteric neurons were analyzed, and histological analysis was performed. The results showed recovery of the DAI and histological tissue integrity in the BBG groups compared to those in the colitis groups. In addition, the numbers of neurons positive for nNOS, ChAT and the P2X7 receptor per area were decreased in the colitis groups, and these measures were recovered in the BBG groups. Neuronal size was increased in the colitis groups and restored in the BBG groups. In conclusion, BBG is effective in improving experimental ulcerative colitis, and the P2X7 receptor may be a therapeutic target.

Predictors of Clinical Course and Outcomes of Acute Diverticulitis: The Role of Age and Ethnicity.

Background and Objectives: Acute diverticulitis (AD) is the leading and most burdensome complication of colonic diverticulosis. However, risk factors for its development and predictors of its course are still poorly defined. In this regard, the association of a young age with a complicated course and worse outcome are still controversial. Moreover, little research has addressed the effect of ethnicity on the course of AD. The current study aimed to evaluate the impact of these variables on AD's course and outcome in the diverse and unique ethnic landscape of Israel. Materials and Methods: We performed a retrospective review of the charts of patients with a radiologically confirmed diagnosis of AD. Patients' outcomes and disease course, including hospitalization duration, complications, and recurrent episodes, were documented and compared among different age and ethnic groups. Multivariate analysis was performed to identify predictors of complicated AD. Results: Overall, 637 patients with AD were included, the majority (95%) had distal colon AD, and almost one quarter of them were aged less than 50 years. The majority of patients in the young age (<50) group were males (69.7%). Nonetheless, the rate of recurrent episodes (35.3% vs. 37.3%, p = 0.19), hospitalization duration (5 ± 4.7 vs. 6 ± 3.2, p = 0.09) and complications rate (17.3% vs. 13.7%; p = 0.16) were similar for both age groups. In the ethnicity group analysis, Arab minority patients had a first episode of AD at a significantly younger age compared to their Jewish counterparts (51.8 vs. 59.4 years, p < 0.001). However, factors such as a complicated course (16% vs. 15%; p = 0.08) and relapsing episode rates (33% vs. 38%; p = 0.36) did not differ significantly between groups. None of the variables, including young age and ethnic group, were predictors of complicated AD course in the multivariate analysis. Conclusion: AD is increasingly encountered in young patients, especially in ethnic minority groups, but neither ethnicity nor young age was associated with worse outcomes.

Can olive oil prevent distal colon mucosal atrophy caused by disuse in rats with colostomy? An experimental animal study.

AIM: This study aims to investigate the effects of pure olive oil on mucosal atrophy of the distal colon in rats. <br/><br/>Material and methods: The study included 28 male albino Wistar rats weighing 300-350 g. A total of 28 animals were randomly allocated to four groups: group 1: control group (n = 6); group 2: ostomy group (n = 6); group 3: ostomy + saline group (n = 8); group 4: ostomy + olive oil group (n = 8). By definition, group 1 did not undergo any procedure. The same surgical procedure was performed for groups 2, 3, and 4 as described below. In all animals from these groups, a two-centimeter-long mid-line incision was made and the colon was divided into 5 cm sections, measured from the distal colon to the caecum. Proximal and distal stomas were created 2 cm apart in the midline with the use of single-layer interrupted sutures. All rats were kept under close daily observation until they were terminated postoperatively after the 1st month. Animals from group 2 did not undergo any additional procedures, while those fromgroups 3 and 4 were given 2 mL of saline and olive oil twice a day, respectively. At the end of the 1st month, the rats were re-operated through the same approach. Biopsies were taken from the proximal and distal stomas of all rats in the same manner for further histopathological analysis. <br/><br/>Results: Group 1 showed no significant differences in terms of mucosal thickness, muscular thickness, wall thickness or colonic lumen diameter between the proximal and distal segments of the colon. Although there were significant differences between the proximal and distal colostomies for each parameter in groups 2, 3, and 4, the mucosal thickness, muscular thickness, wall thickness, and colonic lumen diameter differences for proximal and distal ostomies were very small in group 4 when compared to groups 2 and 3. <br/><br/>Conclusion: The administration of pure olive oil through the distal colon before colostomy closure may reduce the difference in diameter between the proximal and distal intestinal segments. As a result, a more straightforward surgical procedure may be achieved.

Effect of low-threshold versus high-threshold genitalia stimuli on the cystometry parameters in male rats.

The cross talk between external genitalia and urinary bladder could be used as part of management to certain pathological conditions affecting urinary bladder. Since urinary bladder function is also affected by pathologies of other organs (e.g., colon and esophagus), the effect of genitalia stimuli on parameters of bladder function in normal or under different pathological conditions needs to be characterized. Cystometry recordings in male rats were used to examine the effect of low-threshold (LT) and high-threshold (HT) stimulation of the scrotum and penis on urinary bladder function. These effects were studied in intact, colon irritation (CI), and esophagus irritation (EI) groups. Although HT penile stimulation had a significant inhibitory effect on micturition reflex in all groups, CI hypersensitized the penile-bladder inhibitory reflex. In addition, LT penile stimulation had a significant inhibitory effect on micturition, which was significant in CI group only. On the other hand, HT penile stimulation in CI group significantly increased the timing parameters of cystometry. Whereas LT and HT penile stimuli in EI group had a significantly increasing effect on all pressure parameters of cystometry. The scrotal stimuli had minimal effect on bladder function in all groups except for HT scrotal stimulation in the CI group, where it had a significant inhibitory effect on micturition reflex and significantly increased the maximum pressure and pressure amplitude of micturition cycles. These results show that CI and EI exacerbate the effects of genitalia stimuli, especially penile stimuli, on urinary bladder function.

To what extent is male excess risk of advanced colorectal neoplasms explained by known risk factors? Results from a large German screening population.

Colorectal cancer (CRC) incidence and prevalence of its precursors are substantially higher among males than among females in most countries but the reasons for the male excess risk are incompletely understood. We aimed to assess to what extent it is explained by known risk factors. Prevalence of advanced neoplasia (AN, ie, CRC or advanced adenoma) and CRC risk and preventive factors were ascertained among 15 985 participants of screening colonoscopy aged 55-79 years in Germany. Logistic regression was used to calculate odds ratios (ORs) for the association between male sex and AN with and without adjustment for known risk and preventive factors. In age-adjusted comparisons, men had 2-fold increased risk for AN compared to women (OR = 1.98, 95% confidence interval [CI] 1.79-2.19). After comprehensive adjustment for medical, lifestyle and dietary factors, the OR was reduced to 1.52 (95% CI 1.30-1.77), suggesting that these factors accounted for 47% of male excess risk. Male excess risk increased from proximal colon to distal colon and rectum, with age-adjusted ORs (95% CI) of 1.63 (1.38-1.91), 2.13 (1.85-2.45) and 2.36 (1.95-2.85), respectively, and with the proportion of excess risk explained by covariates being lower for AN in the rectum (26%) than for AN in the proximal (52%) or distal colon (46%). Male excess risk was somewhat lower (age-adjusted OR 1.87) and explained excess risk was smaller (36%) when men were compared to women who never used hormone replacement therapy. In conclusion, most of the male excess risk and the potential to overcome it remain to be explored by further research.

Differences in the On- and Off-Tumor Microbiota between Right- and Left-Sided Colorectal Cancer.

This study aims to determine differences in the on- and off-tumor microbiota between patients with right- and left-sided colorectal cancer. Microbiome profiling of tumor and tumor-adjacent biopsies from patients with right-sided (n = 17) and left-sided (n = 7) colorectal adenocarcinoma was performed using 16S ribosomal RNA sequencing. Off-tumor alpha and beta diversity were significantly different between right- and left-sided colorectal cancer patients. However, no differences in on-tumor diversity were observed between tumor locations. Comparing the off-tumor microbiota showed the right colon to be enriched with species of the Lachnoclostridium, Selenomonas, and Ruminococcus genera. Whereas the left colon is enriched with Epsilonbacteraeota phylum, Campylobacteria class, and Pasteurellales and Campylobacterales orders, in contrast, the on-tumor microbiota showed relatively fewer differences in bacterial taxonomy between tumor sites, with left tumors being enriched with Methylophilaceae and Vadin BE97 families and Alloprevotella, Intestinibacter, Romboutsia, and Ruminococcus 2 genera. Patients with left-sided colorectal cancer had large taxonomic differences between their paired on- and off-tumor microbiota, while patients with right-sided colorectal cancer showed relatively fewer taxonomic differences. Collectively, this suggests that the right and left colon show distinctive bacterial populations; however, the presence of a colonic tumor leads to a more consistent microbiota between locations.

Comparative mutational analysis of distal colon cancer with rectal cancer.

Distal colon and rectal cancer are associated with each other but display distinct clinical behavior; however, the genetic basis for these differences is poorly understood. In the present study, a systematic comparison of mutational profiles between 137 distal colon and 125 rectal cancer samples was performed based on the data from the Memorial Sloan Kettering Cancer Center. Tumor mutational burden analysis showed that distal colon and rectal cancer harbored a similar burden of ~5.9 mutations/megabase, irrespective of the mismatch repair status. Comparison of significantly mutated genes between the groups determined that B-Raf proto-oncogene serine/threonine kinase mutations were enriched in distal colon cancer, whilst RAS and SMAD family member 4 (SMAD4) mutations were significantly more frequent in rectal cancer. Furthermore, two novel and potentially targetable hotspot mutations (APC regulator of WNT signaling pathway R876* and SMAD4 R361) were identified, which were enriched in rectal cancer compared with distal colon cancer. Overall, the results of the present study showed that the mutation profiles of distal colon and rectal cancer were largely similar, but distinct in specific key genetic events, which may provide valuable information for improving the management of patients with the disease.

Characterization of ethyl acetate and n-butanol extracts of Cymbopogon schoenanthus and Helianthemum lippii and their effect on the smooth muscle of the rat distal colon.

ETHNOPHARMACOLOGY RELEVANCE: Cymbopogon schoenanthus (C. schoenanthus) and Helianthemum lippii (H. lippii) are Saharan species found in the South West of Algeria, in the region of Bechar. Both plants are used in traditional medicine to treat gastrointestinal disorders. OBJECTIVE: The aim of our study was to characterize the composition of the ethyl acetate (EtOAc) and n-Butanol (n-BuOH) extracts of C. schoenanthus and H. lippii, and to elucidate and compare their effect on the reactivity of the rat distal colon. MAIN METHODS: The plants were macerated in a hydroalcoholic solution. After concentration, the aqueous solutions of the residues were submitted to liquid-liquid extractions to obtain EtOAc and n-BuOH extracts. The phenolic and flavonoid content of the extracts was determined by high performance liquid chromatography coupled with mass spectrometry with a time of flight analyzer (HPLC-TOF/MS). The effect of the extracts was tested on the rat distal colon, namely on the basal tone and on KCl- and Ach-induced precontracted preparations. RESULTS: HPLC-TOF/MS identified 32 phenols and flavonoids in the extracts. The four extracts relaxed the rat distal colon, the effect being noticed on the basal tone and on the KCl- and Ach-induced precontractions. The EtOAc and the n-BuOH extracts of H. lippii decreased the basal tone of the rat distal colon more markedly than the correspondent extracts of C. schoenanthus. Moreover, the n-BuOH extract of C. schoenanthus decreased the basal tone more markedly than the EtOAc extract of this plant but there was no difference between extracts of H. lippii. The EtOAc extracts of both C. schoenanthus and H. lippii totally reverted both the KCl- and the Ach-induced precontraction of the rat distal colon. However, the n-BuOH extracts of the two plants reverted the Ach-precontracted colon but not the colon that has been precontracted with KCl. CONCLUSION: Extracts of H. lippii contain a higher level of phenols compared to the extracts of C. schoenanthus. All extracts of C. schoenanthus and H. lippii caused marked relaxation of the isolated rat distal colon, either when applied directly or when tested over KCl- and Ach-induced precontraction. These results give support to the use of C. shoenanthus and H. lippii in traditional medicine, namely for gastrointestinal diseases.

Radiation risk of incident colorectal cancer by anatomical site among atomic bomb survivors: 1958-2009.

Radiation effects on colorectal cancer rates, adjusted for smoking, alcohol intake and frequency of meat consumption and body mass index (BMI) by anatomical subsite (proximal colon, distal colon and rectum) were examined in a cohort of 105,444 atomic bomb survivors. Poisson regression methods were used to describe radiation-associated excess relative risks (ERR) and excess absolute rates (EAR) for the 1958-2009 period. There were 2,960 first primary colorectal cancers including 894 proximal, 871 distal and 1,046 rectal cancers. Smoking, alcohol intake and BMI were associated with subsite-specific cancer background rates. Significant linear dose-responses were found for total colon (sex-averaged ERR/Gy for 70 years old exposed at age 30 = 0.63, 95% confidence interval [CI]: 0.34; 0.98), proximal [ERR = 0.80, 95% CI: 0.32; 1.44] and distal colon cancers [ERR = 0.50, 95% CI: 0.04; 0.97], but not for rectal cancer [ERR = 0.023, 95% CI: -0.081; 0.13]. The ERRs for proximal and distal colon cancers were not significantly different (p = 0.41). The ERR decreased with attained age for total colon, but not for proximal colon cancer, and with calendar year for distal colon cancer. The ERRs and EARs did not vary by age at exposure, except for decreasing trend in EAR for proximal colon cancer. In conclusion, ionizing radiation is associated with increased risk of proximal and distal colon cancers. The ERR for proximal cancer persists over time, but that for distal colon cancer decreases. There continues to be no indication of radiation effects on rectal cancer incidence in this population.

Induction of enteric oxalate secretion by Oxalobacter formigenes in mice does not require the presence of either apical oxalate transport proteins Slc26A3 or Slc26A6.

Oxalobacter sp. promotion of enteric oxalate excretion, correlating with reductions in urinary oxalate excretion, was previously reported in rats and mice, but the mechanistic basis for this affect has not been described. The main objective of the present study was to determine whether the apical oxalate transport proteins, PAT1 (slc26a6) and DRA (slc26a3), are involved in mediating the Oxalobacter-induced net secretory flux across colonized mouse cecum and distal colon. We measured unidirectional and net fluxes of oxalate across tissues removed from colonized PAT1 and DRA knockout (KO) mice and also across two double knockout (dKO) mouse models with primary hyperoxaluria, type 1 (i.e., deficient in alanine-glyoxylate aminotransferase; AGT KO), including PAT1/AGT dKO and DRA/AGT dKO mice compared to non-colonized mice. In addition, urinary oxalate excretion was measured before and after the colonization procedure. The results demonstrate that Oxalobacter can induce enteric oxalate excretion in the absence of either apical oxalate transporter and urinary oxalate excretion was reduced in all colonized genotypes fed a 1.5% oxalate-supplemented diet. We conclude that there are other, as yet unidentified, oxalate transporters involved in mediating the directional changes in oxalate transport across the Oxalobacter-colonized mouse large intestine.