Profile of interstitial cells of Cajal in a murine model of chagasic megacolon.

Disorders of gastrointestinal motility are the major physiologic problem in chagasic megacolon. The contraction mechanism is complex and controlled by different cell types such as enteric neurons, smooth muscle, telocytes, and an important pacemaker of the intestine, the interstitial cells of Cajal (ICCs). The role of ICCs in the progression of acute and chronic Chagas disease remains unclear. In the present work, we investigate the aspects of ICCs in a long-term model of Chagas disease that mimics the pathological aspects of human megacolon. Different subsets of ICCs isolated from Auerbach's myenteric plexuses and muscle layers of control and Trypanosoma cruzi infected animals were determined by analysis of CD117, CD44, and CD34 expression by flow cytometer. Compared with the respective controls, the results showed a reduced frequency of mature ICCs in the acute phase and three months after infection. These results demonstrate for the first time the phenotypic distribution of ICCs associated with functional dysfunction in a murine model of chagasic megacolon. This murine model proved valuable for studying the profile of ICCs as an integrative system in the gut and as a platform for understanding the mechanism of chagasic megacolon development.

Correlation between intestinal BMP2, IFNγ, and neural death in experimental infection with Trypanosoma cruzi.

Megacolon is one of the main late complications of Chagas disease, affecting approximately 10% of symptomatic patients. However, studies are needed to understand the mechanisms involved in the progression of this condition. During infection by Trypanosoma cruzi (T. cruzi), an inflammatory profile sets in that is involved in neural death, and this destruction is known to be essential for megacolon progression. One of the proteins related to the maintenance of intestinal neurons is the type 2 bone morphogenetic protein (BMP2). Intestinal BMP2 homeostasis is directly involved in the maintenance of organ function. Thus, the aim of this study was to correlate the production of intestinal BMP2 with immunopathological changes in C57Bl/6 mice infected with the T. cruzi Y strain in the acute and chronic phases. The mice were infected with 1000 blood trypomastigote forms. After euthanasia, the colon was collected, divided into two fragments, and a half was used for histological analysis and the other half for BMP2, IFNγ, TNF-α, and IL-10 quantification. The infection induced increased intestinal IFNγ and BMP2 production during the acute phase as well as an increase in the inflammatory infiltrate. In contrast, a decreased number of neurons in the myenteric plexus were observed during this phase. Collagen deposition increased gradually throughout the infection, as demonstrated in the chronic phase. Additionally, a BMP2 increase during the acute phase was positively correlated with intestinal IFNγ. In the same analyzed period, BMP2 and IFNγ showed negative correlations with the number of neurons in the myenteric plexus. As the first report of BMP2 alteration after infection by T. cruzi, we suggest that this imbalance is not only related to neuronal damage but may also represent a new route for maintaining the intestinal proinflammatory profile during the acute phase.

Colonic Manifestations and Complications Are Relatively Under-Reported in Systemic Sclerosis: A Systematic Review.

OBJECTIVES: Although systemic sclerosis (SSc) is known to affect the gastrointestinal (GI) tract, most of the literature focuses on esophageal, small intestinal, or anorectal manifestations. There have been no reviews focused on large bowel SSc complications in over 30 years. The aim of this study is to perform a systematic review of colonic manifestations and complications of SSc. METHODS: An experienced librarian conducted a search of databases, including English and Spanish articles. The search used keywords including "systemic sclerosis," "scleroderma," and "colon." A systematic review was performed using Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. Case reports/series were screened for validity by adapting from criteria published elsewhere. RESULTS: Of 1,890 articles, 74 met selection criteria. Fifty-nine of the 77 articles were case reports/series. The most common article topics on colonic SSc complications were constipation/dysmotility (15), colonic volvulus (8), inflammatory bowel disease (7), microscopic colitis (6), megacolon (6), and telangiectasia (6). Colonic manifestations constituted 24% of articles on GI complications of SSc. There were a total of 85 cases (84% women, with a median age of onset of colon complication of 52 years). Limited cutaneous SSc phenotype (65.6%) was more common than diffuse (26.2%). Patients frequently had poor outcomes with high mortality related to colonic complications (27%). Recent studies explore contemporary topics such as the microbiome in SSc and prucalopride for chronic constipation in SSc. DISCUSSION: Colonic complications comprise a large proportion of the published reports on GI symptoms afflicting patients with SSc and require raised diagnostic suspicion and deliberate action to avoid potentially serious complications including death.

Chronic Megacolon Presenting in Adolescents or Adults: Clinical Manifestations, Diagnosis, and Genetic Associations.

OBJECTIVE: Chronic megacolon is rarely encountered in clinical practice beyond infancy or early childhood. Most cases are sporadic, and some are familial megacolon and present during adolescence or adulthood. There is a need for diagnostic criteria and identifying genetic variants reported in non-Hirschsprung's megacolon. METHODS: PubMed search was conducted using specific key words. RESULTS: This article reviews the clinical manifestations, current diagnostic criteria, and intraluminal measurements of colonic compliance to confirm the diagnosis when the radiological imaging is not conclusive. Normal ranges of colonic compliance at 20, 30, and 44 mmHg distension are provided. The diverse genetic associations with chronic acquired megacolon beyond childhood are reviewed, including the potential association of SEMA3F gene in a family with megacolon. CONCLUSIONS: Measuring colonic compliance could be standardized and simplified by measuring volume at 20, 30, and 44 mmHg distension to identify megacolon when radiology is inconclusive. Diverse genetic associations with chronic acquired megacolon beyond childhood have been identified.

Familial chronic megacolon presenting in childhood or adulthood: Seeking the presumed gene association.

OBJECTIVE: We identified a pedigree over five generations with 49 members, some of whom had chronic megacolon presenting in adolescence or adulthood. We aimed to assess the genetic cause of chronic megacolon through clinical and DNA studies. DESIGN: After ethical approval and informed consent, family members provided answers to standard bowel disease questionnaires, radiological or surgical records, and DNA (buccal mucosal scraping). Exome DNA sequencing of colon tissue or blood DNA from seven family members with colon or duodenal dilatation, or no megacolon (n = 1) was carried out. Sanger sequencing was performed in 22 additional family members to further evaluate candidate variants. The study focused on genes of potential relevance to enteric nerve (ENS) maturation and Hirschsprung's disease or megacolon, based on the literature (GFRA1, NKX2-1, KIF26A, TPM3, ACTG2, SCN10A, and C17orf107 [CHRNE]) and other genetic variants that co-segregated with megacolon in the six affected family members. RESULTS: Information was available in all except five members alive at time of study; among 30 members who provided DNA, six had definite megacolon, one megaduodenum, seven significant constipation without bowel dilatation, and 16 normal bowel function by questionnaire. Among genes studied, SEMA3F (g.3:50225360A>G; c1873A>G) was found in 6/6 family members with megacolon. The SEMA3F gene variant was assessed as potentially pathogenic, based on M-CAP in silico prediction. SEMA3F function is associated with genes (KIT and PDGFRB) that impact intestinal pacemaker function. CONCLUSION: Familial chronic megacolon appears to be associated with SEMA3F, which is associated with genes impacting enteric nerve or pacemaker function.

[Rehbein procedure for secondary megacolon in children]. / Operatsiia Rebeina pri vtorichnom megakolon u detei.

AIM: To evaluate the results of Rehbein procedure with extraperitoneal colorectal anastomosis combined with complex conservative treatment in children with secondary megacolon due to chronic constipation. MATERIAL AND METHODS: We carried out surgical interventions in 78 children aged 7-12 years with chronic colostasis resistant to conservative treatment. All patients underwent clinical, laboratory and instrumental examination. All patients were divided into 3 groups depending on type of surgery: group I - colon resection followed by intraperitoneal colorectal anastomosis (28 patients), group II - open Rehbein procedure (29 patients), group III - laparoscopic Rehbein procedure (21 patients). RESULTS: Absence of dyspeptic disorders and enterocolitis in remote postoperative period in patients receiving comprehensive treatment enhanced with new additions is the cause of improved outcomes. Type of surgery should be individualized in view of anatomical colon changes and secondary pathological conditions. Some pathological symptoms observed at preoperative period may be recurrent in long-term postoperative period due to wrong selection of surgery. The risk of recurrent chronic constipation is high after colon resection followed by intraperitoneal colorectal anastomosis. CONCLUSION: Rehbein procedure may be preferred for management of secondary megarectum and megasigma. Laparoscopic technique reduces surgical trauma and requires less postoperative analgesia.

The correlation between diverticulosis and redundant colon.

BACKGROUND: Diverticulosis and redundant colon are colonic conditions for which underlying pathophysiology, management and prevention are poorly understood. Historical papers suggest an inverse relationship between these two conditions. However, no further attempt has been made to validate this relationship. This study set out to assess the correlation between diverticulosis and colonic redundancy. METHODS: Redundant colon, diverticulosis and patient demographics were recorded during colonoscopy. Multivariate binary logistic regression was performed with redundant colon as the dependent variable and age, gender and diverticulosis as independent variables. Nagelkerke R 2 and a receiver operator curve were calculated to assess goodness of fit and internally validate the multivariate model. RESULTS: Redundant colon and diverticulosis were diagnosed in 31 and 113 patients, respectively. The probability of redundant colon was increased by female gender odds ratio (OR) 8.4 (95% CI 2.7-26, p = 0.00020) and increasing age OR 1.7 (95% CI 1.1-2.6, p = 0.017). Paradoxically, diverticulosis strongly reduced the probability of redundant colon with OR of 0.12 (95% CI 0.42-0.32, p = 0.000039). The Nagelkerke R 2 for the multivariate model was 0.29 and the area under the curve at ROC analysis was 0.81 (95% CI 0.73-0.90 p-value 3.1 × 10-8). CONCLUSIONS: This study found an inverse correlation between redundant colon and diverticulosis, supporting the historical suggestion that the two conditions rarely occur concurrently. The underlying principle for this relationship remains to be found. However, it may contribute to the understanding of the aetiology and pathophysiology of these colonic conditions.

A case of giant fecaloma in a 24-year-old woman.

Chronic constipation is a very common complaint at outpatient clinics. It can progress to fecal impaction, and rarely to fecalomas if not managed promptly. Fecaloma is characterized by a hardened large mass of feces frequently localized in sigmoid colon and rectum and is difficult to discharge. Fecaliths, stagnating and hardening by time, may cause intestinal obstruction,ulcer development and colonic wall perforation. We present the case of a 24-year-old woman who admitted to our hospital with complaints of severe constipation with 1 bowel movement every third-fifth day with passage of hard stools only with using laxatives and meteorism. This is a rare case of fecalomas and megacolon, when conservative measures were absolutely ineffective and surgical treatment was needed. Therefore, diagnosis of fecaloma must be considered in patients presenting with chronic constipation and abdominal mass.Further investigations are mandatory to delineate guidelines for clinical management of megacolon especially in women of childbearing age.

Clinical Features and Colonic Motor Disturbances in Chronic Megacolon in Adults.

BACKGROUND: Chronic megacolon is a rare disease of the colonic motor function characterized by a permanent increase in colonic diameter. METHODS: We reviewed electronic medical records of all patients diagnosed with chronic megacolon from 1999 to 2014 at Mayo Clinic. Our aim was to summarize clinical and motility features, including colonic compliance and tone measured by colonic barostat-controlled 10-cm-long infinitely compliant balloon. Colonic compliance curves were compared to healthy control (40) and disease (47) control groups. RESULTS: Among 24 identified patients, the mean maximal colonic diameter on abdominal radiograph was 12.7 ± 0.8 cm. The cause of megacolon was idiopathic in 16 of 24 and secondary in 8 of 24. A relatively high prevalence (10/24) of comorbid pelvic floor dyssynergia was identified. At the time of this report, 16 patients had undergone colectomy. In general, megacolon presented high fasting colonic volume at relatively low pressures (16-20 mmHg), suggesting high colonic compliance; similarly, volumes at operating pressures that ensured apposition of the balloon to the colonic wall suggested low colonic tone. Median balloon volume at 44 mmHg distension was 584 mL (IQR 556.5-600) in patients with megacolon compared to 251 mL (212-281) in healthy, 240 mL (207-286) in functional constipation, and 241 mL (210.8-277.5) in diarrhea-predominant irritable bowel syndrome controls. Colon's tonic response to feeding was generally intact, and there was frequently maintained phasic contractile response to feeding. CONCLUSIONS: Chronic megacolon is a severe colonic dysmotility, manifesting radiologically with increased colonic diameter; it can be proven by measuring colonic compliance and typically requires colectomy because of failed medical therapy.

The significantly reduced number of interstitial cells of Cajal in chagasic megacolon (CM) patients might contribute to the pathophysiology of CM.

In addition to neurons, interstitial cells of Cajal (ICC) play an important role in coordinating intestinal motility with a pacemaker function. This study aimed to quantitatively analyze ICC, neurons, and muscular area, the latter to correct for quantitation errors resulting from dilation in case of a megacolon and from the dispersion of ICC that can be attributed to muscular hypertrophy. We analyzed 30 colon samples: ten chagasic megacolon (CM), ten chagasic colons without megacolon (CXM), and ten nonchagasic control patients (NC). We measured the area of muscularis propria and counted the number of neurons of the myenteric plexus in a histological section of an intestinal ring and the number of ICC at the level of the myenteric plexus and circular muscle layer, the latter in a section immunohistochemically stained for CD117. Muscular hypertrophy occurred only in the CM group. Compared to the NC group, we found in the CM group a statistically significant reduction of 80 % in the number of neurons, 60 % in the number of ICC in the myenteric plexus, and 38 % in the area of circular muscle. In the CXM group, these numbers were highly variable, and their reduction, less pronounced. We conclude that the number of ICC is significantly reduced in CM patients, and that this might contribute to the pathophysiology of CM. However, the development of CM requires severe denervation, whereas CXM generally exhibits less than 50 % denervation, favoring the hypothesis that the reduction in ICC number is, in part, a consequence of denervation.

Preponderance of inhibitory versus excitatory intramuscular nerve fibres in human chagasic megacolon.

INTRODUCTION: Megacolon, chronic dilation of a colonic segment, is a frequent sign of Chagas disease. It is accompanied by an extensive neuron loss which, as shown recently, results in a partial, selective survival of nitrergic myenteric neurons. Here, we focused on the balance of intramuscular excitatory (choline acetyltransferase [ChAT]-immunoreactive) and inhibitory (neuronal nitric oxide synthase [NOS]- as well as vasoactive intestinal peptide [VIP]-immunoreactive) nerve fibres. MATERIALS AND METHODS: From surgically removed megacolonic segments of seven patients, three sets of cryosections (from non-dilated oral, megacolonic and non-dilated anal parts) were immunhistochemically triple-stained for ChAT, NOS and VIP. Separate area measurements of nerve profiles within the circular and longitudinal muscle layers, respectively, were compared with those of seven non-chagasic control patients. Additionally, wholemounts from the same regions were stained for NOS, VIP and neurofilaments (NF). RESULTS: The intramuscular nerve fibre density was significantly reduced in all three chagasic segments. The proportions of inhibitory (NOS only, VIP only, or NOS/VIP-coimmunoreactive) intramuscular nerves were 68 %/58 % (circular/longitudinal muscle, respectively) in the controls and increased to 75 %/69 % (oral parts), 84 %/76 % (megacolonic) and 87 %/94 % (anal) in chagasic specimens. In the myenteric plexus, NF-positive neurons co-staining for NOS and VIP also increased proportionally. The almost complete lack of dendritic structures in ganglia of chagasic specimens hampered morphological identification. DISCUSSION AND CONCLUSION: We suggest that preponderance of inhibitory, intramuscular nerve fibres may be one factor explaining the chronic dilation. Since the nerve fibre imbalance is most pronounced in the anal, non-dilated segment, other components of the motor apparatus (musculature, interstitial cells, submucosal neurons) have to be considered.

Role of the enteric nervous system in the colon of patients with idiopathic megacolon.

BACKGROUND/AIMS: To clarify the physiological significance of the enteric nervous system (ENS) in the colon of patients with idiopathic megacolon (IM), we investigated the enteric nerve responses on lesional and normal bowel segments derived from patients with IM and patients who underwent colon resection for colonic cancers. METHODOLOGY: Eighteen preparations were taken from the lesional colon of 5 patients with IM (4 men and 1 woman, aged 46-70 yrs, mean age 55.8 yrs); 42 were taken from the normal colon of 14 patients with colonic cancer (10 men and 4 woman, aged 48-68 yrs, mean age 54.2 yrs). A mechanographic technique was used to evaluate in vitro muscle responses to electrical field stimulation (EFS) of the adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. RESULTS: 1) Responses to EFS before blockade of adrenergic and cholinergic nerves. The muscle strips in both normal and IM colon demonstrated relaxation reactions rather than contraction reactions by EFS. The relaxation reaction to EFS in the IM was significantly stronger than that in the normal colon (p=0.0366). 2) Responses to EFS after blockade of the adrenergic and cholinergic nerves. The muscle strips in both normal and IM colon demonstrated relaxation reactions rather than contraction reactions by EFS. The relaxation reaction to EFS in the IM was stronger than that in the normal colon (p=0.0467). 3) Tetrodotoxin abolished the EFS responses in the muscle strips in both normal colon and abnormal colon with IM. CONCLUSIONS: An increase of NANC inhibitory nerves plays an important role in the impaired motility observed in the colon of patients with IM.

Reduced population of interstitial cells of Cajal in Chagasic megacolon.

BACKGROUND/AIMS: In Chagasic megacolon, there is a reduction in the population of interstitial cells of Cajal. It was aimed to evaluate density of Cajal cells in the resected colon of Chagasic patients compared to control patients and to verify possible association between preoperative and postoperative bowel function of megacolon patients and cell count. METHODOLOGY: Sixteen megacolon patients (12 female; mean age 54.4 (31-73)) were operated on. Pre- and postoperative evaluation using Cleveland clinic constipation score was undertaken. Resected colons were examined. Cajal cells were identified by immunohistochemistry (anti-CD117). The mean cell number was compared to resected colons from 16 patients (7 female; mean age 62.8 (23-84)) with non-obstructive sigmoid cancer. Association between pre- and postoperative constipation scores and cell count for megacolon patients was evaluated using the Pearson test (r). RESULTS: A reduced number of Cajal cells (per field: 2.84 (0-6.6) vs. 9.68 (4.3-13); p<0.001) were observed in the bowel of megacolon patients compared to cancer patients. No correlation between constipation score before (r=- 0.205; p=0.45) or after surgery (r=0.291; p=0.28) and cell count in megacolon was observed. CONCLUSIONS: Patients with megacolon display marked reduction of interstitial cells of Cajal. An association of constipation severity and Cajal cells depopulation was not demonstrated.

[Effects of electroacupuncture of different acupoints on changes of blood pressure and autonomic nerve system after colorectal distension in rats].

OBJECTIVE: To observe the influence of electroacupuncture (EA) of different acupoints on changes of mean arterial pressure (MAP), heart rate (HR) and heart rate variability (HRV) in colorectal distension (CRD) rats, so as to analyze the specificity of actions of acupoints in relieving visceral pain and regulating activities of the autonomic nerve system. METHODS: Forty-five Wistar rats were randomized into control, Zusanli (ST 36), non-acupoint, Neiguan (PC 6) and Taichong (LR 3) groups (n = 9/group). Under anesthesia, CRD was given to the rats by using an aerostat for 5 min. EA (2 Hz/15 Hz, 2 mA) was applied to bilateral ST 36, non-acupoint (1.0 cm lateral to ST 36), PC 6 and LR 3 for 15 min, respectively. Electrocardiogram of the cervico-chest lead was recorded by using a bioelectric amplifier, and MAP recorded by using a pressure transducer and an amplifier. Low frequency and high frequency of HRV were analyzed by Chart 5.0. RESULTS: Following CRD, the HR, MAP, LF and LF/HF levels increased significantly in all the 5 groups (P < 0.05), while HF had no apparent changes (P > 0.05). Compared with the control group, 5 min and 15 min after EA ,and 10 min after ceasing EA, MAP values of ST 36 and PC 6 groups were decreased obviously (P < 0.05). The HR values of ST 36 and PC 6 groups at 15 min after EA and 10 min after ceasing EA were decreased markedly in comparison with those of each of the other groups during CRD (P < 0.05). The LF levels of both ST 36 and PC 6 groups at 5 min after EA, and those of ST 36, PC 6 and LR 3 at 15 min after EA were significantly lower than those of control group (P < 0.05). LF/HF levels of ST 36 and PC 6 at 10 min after ceasing EA were obviously lower than those of control group (P < 0.05). No significant differences were found among ST 36, non-acupoint, PC 6 and LR 3 groups in HR, LF and LF/HF (P > 0.05). CONCLUSION: EA of ST 36 and PC 6 can suppress CRD-induced increase of MAP, HR and LF/HF, suggesting beneficial effects of EA in relieving visceral pain and mediating autonomic nerve system. The aforementioned effects of EA of LR 3 and non-acupoint are not obvious.

Idiopathic proximal hemimegacolon: radiologic findings and analyses of clinical and physiological characteristics.

BACKGROUND: Idiopathic megacolon with bowel dilatation only proximal to the splenic flexure is an uncommon and poorly characterized disease. This study aimed to identify the characteristics of idiopathic proximal hemimegacolon. METHODS: Five patients (2 males and 3 females) were diagnosed to have idiopathic proximal hemimegacolon and their radiologic, clinical, and physiological characteristics were reviewed. Hirschsprung's disease and other known causes of bowel dilatation were excluded by the presence of rectoanal inhibitory reflex and reviewing medical records. RESULTS: Mean age at diagnosis and symptom onset were 50.4 years and 47.2 years, respectively. Four patients presented with constipation, and all five patients showed abdominal distention and abdominal pain. Four patients were successfully treated and maintained only with laxatives and prokinetics without enema. Only one patient underwent surgery for intractable constipation. Mean maximal diameters of each segment of colons measured by computed tomography were 57.5 mm, 69.3 mm, 73.0 mm, 33.3 mm, 24.0 mm, and 27.3 mm for cecum, ascending colon, transverse colon, descending colon, sigmoid colon, and rectum, respectively. Colon transit time was delayed in four patients with mean value of 90.0 h. CONCLUSIONS: These results indicated that patients with idiopathic proximal hemimegacolon may be treated successfully only with medical therapy in most cases.