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Toxic megacolon  


... a complication of inflammatory bowel disease, such as ulcerative colitis and Crohn's disease , and infections of the colon. ... Treating diseases that cause toxic megacolon, such as ulcerative colitis or Crohn's disease, can prevent this condition.


Megacolon in the cat.  


Megacolon is a condition that is not uncommon in the cat. Most cases are idiopathic (a cause cannot be determined), and these seem to be a result of colonic inertia. Pelvic fracture malunions are the next most common cause and result in a pelvic outlet obstruction. Total or subtotal colectomy offers good long-term results in cases of idiopathic megacolon and chronic cases of pelvic fracture malunion, and the technique is described in detail. PMID:12148317

Bertoy, Robert W



Acute and chronic megacolon.  


Megacolon, defined as dilation of the abdominal colon, may occur acutely or in a chronic form. Acute megacolon that occurs in association with severe inflammation of the colon is known as toxic megacolon, whereas acute megacolon without obvious colonic disease is known as Ogilvie's syndrome. The pathophysiology and management of toxic megacolon, Ogilvie's syndrome, and chronic megacolon in adults differ significantly, and it is critically important to distinguish among these entities. Toxic megacolon is a medical emergency that requires coordinated intensive medical and surgical management. In addition to vigorous resuscitation with fluids, electrolytes, and blood products, medical treatment consists of parenteral corticosteroids, broad-spectrum antibiotics, and close monitoring of the patient. Surgical intervention is required if there is no improvement, or deterioration after 12 to 24 hours of intensive medical management, or if there is evidence of colon perforation. Ogilvie's syndrome usually occurs in hospitalized patients with serious underlying medical or surgical illnesses. Management is directed at preventing ischemia and perforation of the distended colon. Supportive therapy includes nasogastric suction, correction of fluid and electrolyte imbalances, stopping potentially aggravating medications, and decompressing the colon with a rectal tube and positional changes. Intravenous neostigmine is the only pharmacologic agent of proven efficacy; colonoscopic decompression is an alternative in patients who do not respond to neostigmine or who have conditions that contraindicate its use. Daily oral administration of polyethylene glycol electrolyte solutions appears to decrease the relapse rate after initial decompression is achieved. Chronic megacolon in adults represents advanced colon failure that does not respond to pharmacologic stimulation. Goals of therapy are to cleanse the colon, prevent impaction, and minimize stool volume and gas buildup. For patients with disabling symptoms, surgical exclusion of the colon, decompression and antegrade enemas via cecostomy, or subtotal or segmental resection may be palliative. PMID:17547862

Hanauer, Stephen B; Wald, Arnold



Myxedema megacolon after external neck irradiation  

SciTech Connect

Myxedema megacolon is a rare manifestation of hypothyroidism. It may respond to appropriate treatment but is sometimes irreversible, resulting in fatal complications. Two possible mechanisms to explain the colonic atony include (1) myxomatous infiltration of the submucosa with separation of the muscular fibers from the ganglia of Auerbach's plexus, and (2) severe autonomic neuropathy affecting the extrinsic nerves to the colon and the myenteric plexus. Histology from our case supports the first proposed mechanism. Urecholine challenge and manometric measure response may help predict reversibility of colonic atony. Treatment should be individualized and should include factors such as age, duration of symptoms, and other medical illness. Low-dose oral or intravenous triiodothyronine is effective. Hypothyroidism following external radiation of the neck for lymphoma is not uncommon, and the risk increases following one or more lymphangiograms. Such patients should be followed up with regular TSH estimations for at least three years.

Borrie, M.J.; Cape, R.D.; Troster, M.M.; Fung, S.T.



A Case of Toxic Megacolon Caused by Clostridium difficile Infection and Treated with Fecal Microbiota Transplantation  

PubMed Central

Toxic megacolon is a rare clinical complication of fulminant Clostridium difficile infection. The mortality rate of fulminant C. difficile infection is reported to be as high as 50%. Fecal microbiota transplantation is a highly effective treatment in patients with recurrent or refractory C. difficile infection. However, there are few published articles on the use of such transplantation for fulminant C. difficile infection. Here, we report on a patient with toxic megacolon complicated by C. difficile infection who was treated successfully with fecal microbiota transplantation. PMID:25721003

Gweon, Tae-Geun; Lee, Kyung Jin; Kang, Donghoon; Park, Sung Soo; Kim, Kyung Hoon; Seong, Hyeonjin; Ban, Tae-Hyun; Moon, Sung Jin; Kim, Jin Su; Kim, Sang Woo



Clinical features of idiopathic megarectum and idiopathic megacolon.  

PubMed Central

BACKGROUND: Dilatation of the rectum and/or colon, in the absence of demonstrable organic disease, is an uncommon and poorly characterised condition. AIMS: To characterise the clinical and diagnostic features, and response to treatment, of patients with idiopathic megarectum (IMR) and idiopathic megacolon (IMC). METHODS: A retrospective review was undertaken of all patients operated on for these conditions over a 23 year period. In addition all patients treated over a three year period were prospectively studied by means of a questionnaire, contrast studies of the upper and lower intestine, spine x rays to exclude spinal dysraphism, anorectal physiological studies, and assessment of clinical outcome. Patients with Hirschsprung's disease and other known causes of gut dilatation were excluded. RESULTS: (i) Retrospective study: Of 63 operated patients, 22 had IMR, 23 had IMR and IMC, and 18 had IMC only. Five patients with IMC had previous sigmoid volvulus, and three had associated non-gastrointestinal congenital abnormalities. Faecal incontinence was always associated with rectal impaction and 14 patients (82%) with IMR alone had had manual disimpaction. (ii) Prospective study: Twenty two patients had IMR, with a median rectal diameter of 10 cm (normal < 6.5 cm). Six patients had IMC and one patient had IMR and IMC. Patients with IMR were significantly (p = 0.0007) younger than patients with IMC. All patients with IMR became symptomatic in childhood, compared with half the patients with IMC who developed symptoms as adults. Patients with IMR all presented with soiling and impaction, compared with patients with IMC whose symptoms were variable and included constipation or increased bowel frequency, pain, and variable need for laxatives. No upper gut dilatation was seen in either group of patients. Spinal dysraphism was seen in two of 18 patients with IMR and two of four with IMC, suggesting extrinsic denervation as a possible cause in a minority. Twelve of 22 patients with IMR had a maximum anal resting pressure below normal, indicating sphincter damage or inhibition. Both IMR and IMC patients had altered rectal sensitivity to distension, suggesting that despite lack of dilatation the rectum in IMC has altered viscoelasticity, tone, or sensory function. Fifteen of 22 patients with IMR were successfully managed with laxatives or enemas, but seven required surgery. Two of seven patients with IMC required surgery, including one for sigmoid volvulus. CONCLUSIONS: Patients with IMR differ clinically, diagnostically, and in their outcome from patients with IMC. These conditions demand specific investigation, and intensive treatment, to achieve optimum care. PMID:9274479

Gattuso, J M; Kamm, M A



Trypanosomiasis-Induced Megacolon Illustrates How Myenteric Neurons Modulate the Risk for Colon Cancer in Rats and Humans  

PubMed Central

Background Trypanosomiasis induces a remarkable myenteric neuronal degeneration leading to megacolon. Very little is known about the risk for colon cancer in chagasic megacolon patients. To clarify whether chagasic megacolon impacts on colon carcinogenesis, we investigated the risk for colon cancer in Trypanosoma cruzi (T. cruzi) infected patients and rats. Methods Colon samples from T. cruzi-infected and uninfected patients and rats were histopathologically investigated with colon cancer biomarkers. An experimental model for chemical myenteric denervation was also performed to verify the myenteric neuronal effects on colon carcinogenesis. All experiments complied the guidelines and approval of ethical institutional review boards. Results No colon tumors were found in chagasic megacolon samples. A significant myenteric neuronal denervation was observed. Epithelial cell proliferation and hyperplasia were found increased in chagasic megacolon. Analyzing the argyrophilic nucleolar organiser regions within the cryptal bottom revealed reduced risk for colon cancer in Chagas’ megacolon patients. T. cruzi-infected rats showed a significant myenteric neuronal denervation and decreased numbers of colon preneoplastic lesions. In chemical myenteric denervated rats preneoplastic lesions were reduced from the 2nd wk onward, which ensued having the colon myenteric denervation significantly induced. Conclusion/Significance Our data suggest that the trypanosomiasis-related myenteric neuronal degeneration protects the colon tissue from carcinogenic events. Current findings highlight potential mechanisms in tropical diseases and cancer research. PMID:25884710

Kannen, Vinicius; de Oliveira, Enio C.; Motta, Bruno Zene; Chaguri, Annuar Jose; Brunaldi, Mariângela Ottoboni; Garcia, Sérgio B.



A novel pathogenesis of megacolon in Ncx/Hox11L.1 deficient mice.  

PubMed Central

The Ncx/Hox11L.1 gene, a member of the Hox11 homeobox gene family, is mainly expressed in neural crest-derived tissues. To elucidate the role of Ncx/Hox11L.1, the gene has been inactivated in embryonic stem cells by homologous recombination. The homozygous mutant mice were viable. These mice developed megacolon with enteric ganglia by age 3-5 wk. Histochemical analysis of the ganglia revealed that the enteric neurons hyperinnervated in the narrow segment of megacolon. Some of these neuronal cells degenerated and neuronal cell death occurred in later stages. We propose that Ncx/Hox11L.1 is required for maintenance of proper functions of the enteric nervous system. These mutant mice can be used to elucidate a novel pathogenesis for human neuronal intestinal dysplasia. PMID:9259577

Hatano, M; Aoki, T; Dezawa, M; Yusa, S; Iitsuka, Y; Koseki, H; Taniguchi, M; Tokuhisa, T



A Case of Toxic Megacolon Caused by Clostridium difficile Infection and Treated with Fecal Microbiota Transplantation.  


Clostridium difficile infection. The mortality rate of fulminant C. difficile infection is reported to be as high as 50%. Fecal microbiota transplantation is a highly effective treatment in patients with recurrent or refractory C. difficile infection. However, there are few published articles on the use of such transplantation for fulminant C. difficile infection. Here, we report on a patient with toxic megacolon complicated by C. difficile infection who was treated successfully with fecal mi-crobiota transplantation. (Gut Liver, 2015;9:247-250). PMID:25721003

Gweon, Tae Geun; Lee, Kyung Jin; Kang, Dong Hoon; Park, Sung Soo; Kim, Kyung Hoon; Seong, Hyeon Jin; Ban, Tae Hyun; Moon, Sung Jin; Kim, Jin Su; Kim, Sang Woo



Conservative surgical treatment for toxic megacolon due to Clostridium difficile infection in a transplanted pediatric patient.  


Severe disease caused by Clostridium difficile is frequently encountered in transplant recipients and carries a high mortality. Numerous studies have been published on this subject in the adult population, but few in the pediatric setting. A 4-year-old boy who had undergone heart transplant 20 months earlier was admitted to the pediatric intensive care unit after humoral rejection. Seven days after admission, he developed septic shock, abdominal distension, and paralytic ileus without diarrhea. Pseudomembranous colitis due to C. difficile was confirmed by microbiological and radiological studies. Despite treatment with rectal vancomycin and intravenous metronidazole, the patient did not improve and required decompressive laparotomy; because of the poor subsequent clinical course, terminal ileostomy and cecostomy were performed in a second operation. Recovery was satisfactory, and surgical reconstruction of intestinal tract was performed 3 months later without complications. Although early surgery with total colectomy is indicated, when there is a poor response to medical treatment in cases of C. difficile toxic megacolon, the case we present responded favorably to a conservative surgical approach that enabled intestinal integrity to be restored 3 months later. In the pediatric population, less aggressive therapeutic options should be considered, as they have benefits on the subsequent quality of life of the patient. PMID:22726419

Castillo, A; López, J; Panadero, E; Cerdá, J; Padilla, B; Bustinza, A



Could the complications of megacolon be avoided by monitoring the risk patients? cases report.  


We report 2 cases of megacolon associated with cerebrovascular accident and neuropsychiatric drug consumption. Case report 1: a 75-year-old woman with diabetes mellitus, hypertension, tachycardia with atrial fibrillation, bilateral pleural effusions and previous cerebral hemorrhage was admitted in our hospital. She presented clouded sensorium and abdominal distension, with closed alvus. The CT scan showed a distension of the colon, with severe fecal impaction. A volvulus of the sigma was found at surgical intervention.Case report 2: a 59-year-old man with a medical history of oligophrenia was admitted to our hospital for acute abdomen.He presented stupor and closed alvus with abdominal distension. The abdominal CT scan showed a dolichosigma, with fecal impaction. The patient was submitted to a laparotomy and a two millimetres perforation of the sigma was found.The sigma had a diameter of 28 cm and a length of 75 cm.Even if a clear correlation has not been found yet, anomalies of the regulation of the gastro-intestinal motility can occur at different levels in patients with psychiatric or cerebrovascular diseases and drug consumption with anticholinergic properties,and they should be carefully monitored. The purpose is an early diagnosis of colon function anomalies in order to avoid potentially fatal complications. PMID:25149623

Toro, A; Cappello, G; Mannino, M; Di Carlo, I



Male-Biased Aganglionic Megacolon in the TashT Mouse Line Due to Perturbation of Silencer Elements in a Large Gene Desert of Chromosome 10  

PubMed Central

Neural crest cells (NCC) are a transient migratory cell population that generates diverse cell types such as neurons and glia of the enteric nervous system (ENS). Via an insertional mutation screen for loci affecting NCC development in mice, we identified one line—named TashT—that displays a partially penetrant aganglionic megacolon phenotype in a strong male-biased manner. Interestingly, this phenotype is highly reminiscent of human Hirschsprung’s disease, a neurocristopathy with a still unexplained male sex bias. In contrast to the megacolon phenotype, colonic aganglionosis is almost fully penetrant in homozygous TashT animals. The sex bias in megacolon expressivity can be explained by the fact that the male ENS ends, on average, around a “tipping point” of minimal colonic ganglionosis while the female ENS ends, on average, just beyond it. Detailed analysis of embryonic intestines revealed that aganglionosis in homozygous TashT animals is due to slower migration of enteric NCC. The TashT insertional mutation is localized in a gene desert containing multiple highly conserved elements that exhibit repressive activity in reporter assays. RNAseq analyses and 3C assays revealed that the TashT insertion results, at least in part, in NCC-specific relief of repression of the uncharacterized gene Fam162b; an outcome independently confirmed via transient transgenesis. The transcriptional signature of enteric NCC from homozygous TashT embryos is also characterized by the deregulation of genes encoding members of the most important signaling pathways for ENS formation—Gdnf/Ret and Edn3/Ednrb—and, intriguingly, the downregulation of specific subsets of X-linked genes. In conclusion, this study not only allowed the identification of Fam162b coding and regulatory sequences as novel candidate loci for Hirschsprung’s disease but also provides important new insights into its male sex bias. PMID:25786024

Touré, Aboubacrine M.; Béland, Mélanie; Raiwet, Diana L.; Silversides, David W.; Pilon, Nicolas



Male-biased aganglionic megacolon in the TashT mouse line due to perturbation of silencer elements in a large gene desert of chromosome 10.  


Neural crest cells (NCC) are a transient migratory cell population that generates diverse cell types such as neurons and glia of the enteric nervous system (ENS). Via an insertional mutation screen for loci affecting NCC development in mice, we identified one line-named TashT-that displays a partially penetrant aganglionic megacolon phenotype in a strong male-biased manner. Interestingly, this phenotype is highly reminiscent of human Hirschsprung's disease, a neurocristopathy with a still unexplained male sex bias. In contrast to the megacolon phenotype, colonic aganglionosis is almost fully penetrant in homozygous TashT animals. The sex bias in megacolon expressivity can be explained by the fact that the male ENS ends, on average, around a "tipping point" of minimal colonic ganglionosis while the female ENS ends, on average, just beyond it. Detailed analysis of embryonic intestines revealed that aganglionosis in homozygous TashT animals is due to slower migration of enteric NCC. The TashT insertional mutation is localized in a gene desert containing multiple highly conserved elements that exhibit repressive activity in reporter assays. RNAseq analyses and 3C assays revealed that the TashT insertion results, at least in part, in NCC-specific relief of repression of the uncharacterized gene Fam162b; an outcome independently confirmed via transient transgenesis. The transcriptional signature of enteric NCC from homozygous TashT embryos is also characterized by the deregulation of genes encoding members of the most important signaling pathways for ENS formation-Gdnf/Ret and Edn3/Ednrb-and, intriguingly, the downregulation of specific subsets of X-linked genes. In conclusion, this study not only allowed the identification of Fam162b coding and regulatory sequences as novel candidate loci for Hirschsprung's disease but also provides important new insights into its male sex bias. PMID:25786024

Bergeron, Karl-F; Cardinal, Tatiana; Touré, Aboubacrine M; Béland, Mélanie; Raiwet, Diana L; Silversides, David W; Pilon, Nicolas



The KIT Gene Is Associated with the English Spotting Coat Color Locus and Congenital Megacolon in Checkered Giant Rabbits (Oryctolagus cuniculus)  

PubMed Central

The English spotting coat color locus in rabbits, also known as Dominant white spotting locus, is determined by an incompletely dominant allele (En). Rabbits homozygous for the recessive wild-type allele (en/en) are self-colored, heterozygous En/en rabbits are normally spotted, and homozygous En/En animals are almost completely white. Compared to vital en/en and En/en rabbits, En/En animals are subvital because of a dilated (“mega”) cecum and ascending colon. In this study, we investigated the role of the KIT gene as a candidate for the English spotting locus in Checkered Giant rabbits and characterized the abnormalities affecting enteric neurons and c-kit positive interstitial cells of Cajal (ICC) in the megacolon of En/En rabbits. Twenty-one litters were obtained by crossing three Checkered Giant bucks (En/en) with nine Checkered Giant (En/en) and two en/en does, producing a total of 138 F1 and backcrossed rabbits. Resequencing all coding exons and portions of non-coding regions of the KIT gene in 28 rabbits of different breeds identified 98 polymorphisms. A single nucleotide polymorphism genotyped in all F1 families showed complete cosegregation with the English spotting coat color phenotype (??=?0.00 LOD ?=?75.56). KIT gene expression in cecum and colon specimens of En/En (pathological) rabbits was 5–10% of that of en/en (control) rabbits. En/En rabbits showed reduced and altered c-kit immunolabelled ICC compared to en/en controls. Morphometric data on whole mounts of the ascending colon showed a significant decrease of HuC/D (P<0.05) and substance P (P<0.01) immunoreactive neurons in En/En vs. en/en. Electron microscopy analysis showed neuronal and ICC abnormalities in En/En tissues. The En/En rabbit model shows neuro-ICC changes reminiscent of the human non-aganglionic megacolon. This rabbit model may provide a better understanding of the molecular abnormalities underlying conditions associated with non-aganglionic megacolon. PMID:24736498

Fontanesi, Luca; Vargiolu, Manuela; Scotti, Emilio; Latorre, Rocco; Faussone Pellegrini, Maria Simonetta; Mazzoni, Maurizio; Asti, Martina; Chiocchetti, Roberto; Romeo, Giovanni; Clavenzani, Paolo; De Giorgio, Roberto



Management of Acute Colitis and Toxic Megacolon  

PubMed Central

Severe colitis is a well-defined condition that can develop in patients afflicted with ulcerative colitis, but typically responds to a variety of medical therapies. Operative intervention is warranted when massive hemorrhage, perforation, or peritonitis complicates the clinical scenario or medical therapy fails to control the disease. Of the operative options, total/subtotal colectomy and end ileostomy is the usual procedure of choice especially if the operation can be performed through a laparoscopic approach. PMID:22131898

Strong, Scott A.



V152 Feline Constipation\\/Obstipation\\/Megacolon  

Microsoft Academic Search

? Constipation is primarily a problem of domestication and sedentary life style in the feline species. ? Neural injury accounts for 5-10% of cases, pelvic outflow obstruction account for 20-25% of cases, and idiopathic constipation (smooth muscle dysfunction) account for most (>60%) of cases. ? Prokinetic therapy is more difficult with constipation disorders because of differences in regional (i.e., colonic)

Robert J. Washabau


Systematic Review of Surgical Options for Idiopathic Megarectum and Megacolon  

PubMed Central

Objective: A subgroup of patients with intractable constipation has persistent dilatation of the bowel, which in the absence of an organic cause is termed idiopathic megabowel (IMB). The aim of this systematic review was to evaluate the published outcome data of surgical procedures for IMB in adults. Methods: Electronic searches of the MEDLINE (PubMed) database, Cochrane Library, EMBase, and Science Citation Index were performed. Only peer-reviewed articles of surgery for IMB published in the English language were evaluated. Studies of all surgical procedures were included, providing they were performed on 3 or more patients, and overall success rates were documented. Studies were critically appraised in terms of design and methodology, inclusion criteria, success, mortality and morbidity rates, and functional outcomes. Results: A total of 27 suitable studies were identified, all evidence was low quality obtained from case series, and there were no comparative studies. The studies involved small numbers of patients (median 12, range 3–50), without long-term follow-up (median 3 years, range 0.5–7). Inclusion of subjects, methods of data acquisition, and reporting of outcomes were extremely variable. Subtotal colectomy was successful in 71.1% (0%–100%) but was associated with significant morbidity related to bowel obstruction (14.5%, range 0%–29%). Segmental resection was successful in 48.4% (12.5%–100%), and recurrent symptoms were common (23.8%). Rectal procedures achieved a successful outcome in 71% to 87% of patients. Proctectomy, the Duhamel, and pull-through procedures were associated with significant mortality (3%–25%) and morbidity (6%–29%). Vertical reduction rectoplasty (VRR) offered promising short-term success (83%). Pelvic-floor procedures were associated with poor outcomes. A stoma provided a safe alternative but was only effective in 65% of cases. Conclusions: Outcome data of surgery for IMB must be interpreted with extreme caution due to limitations of included studies. Recommendations based on firm evidence cannot be given, although colectomy appears to be the optimum procedure in patients with a nondilated rectum, restorative proctocolectomy the most suitable in those with dilatation of the colon and rectum, and VRR in those patients with dilatation confined to the rectum. Appropriately designed studies are required to make valid comparisons of the different procedures available. PMID:15798457

Gladman, Marc A.; Scott, S Mark; Lunniss, Peter J.; Williams, Norman S.



[Rectocolonic plasty using mechanical stapler as a surgical solution in complications of megacolon].  


Hirschsprung's disease surgically treated with Duhamel's technique in which no mechanical suture has been used, usually presents, as main complication, cronic constipation, due to fecalomas in the rectal pouch. In our experience (30 cases plus four patients sent to our hospital for reintervention), this complication is not present when mechanical suture is introduced to the Duhamel's Technique. This allows us to assure that perineal rectocoloplasty, with auto-suture material is a precise optional treatment, with excellent results and allows the chance of not going through laparotomy in those cases that require reintervention. PMID:8679386

Vilariño, A; Cano, I; Benavent, I; Portela, E; Matute, J A; Delgado, M D; Pertejo, E M; Jiménez, M A; Manzanera, M; Pacheco, J A



Interaction of human chagasic IgG with human colon muscarinic acetylcholine receptor: molecular and functional evidence  

PubMed Central

BACKGROUND AND AIMS—Gastrointestinal disorders is one of the clinical manifestations of chronic Chagas' disease. The pathogenesis seems to be associated with autonomic dysfunction. Here, we consider the muscarinic cholinoceptor mediated alteration in distal colon function in chagasic megacolon.?PATIENTS—Patients were divided into four groups: group I, chronic chagasic patients with megacolon; group II, chronic chagasic patients without megacolon; group III, non-chagasic patients with megacolon; and group IV, normal healthy volunteers (control).?METHODS—Binding assay and immunoblot of cholinoceptors from human and rat colon and enzyme immunoassay (ELISA) using a synthetic 24mer peptide corresponding to the second extracellular loop of human M2 muscarinic acetylcholine receptors (mAChR) were used to detect the presence of serum antibodies. The effect of antibodies on basal tone and 3',5'-cyclic monophosphate (cAMP) production of human and rat distal colon strips were also tested.?RESULTS—Group I but not the other groups had circulating antibodies capable of interacting with human colon activating M2 mAChR, as they competed with binding of specific radioligand to mAChR and interacted with the second extracellular loop of human M2 mAChR. Moreover, affinity purified anti-M2 peptide IgG from group I, in common with monoclonal antihuman M2 mAChR, recognised bands with a molecular weight corresponding to colon mAChR. This antibody also displayed an agonist-like activity, increasing basal tone and decreasing cAMP accumulation. Both effects were blunted by AF-DX 116 and neutralised by the synthetic peptide.?CONCLUSIONS—In chagasic patients with megacolon there are antibodies that can recognise and activate M2 mAChR. The implications of these autoantibodies in the pathogenesis of chagasic megacolon is discussed.???Keywords: chagasic megacolon; acetylcholine receptor; antibodies; colon contractility PMID:11600475

Sterin-Borda, L; Goin, J; Bilder, C; Iantorno, G; Hernando, A; Borda, E



A Cysteine Protease Inhibitor Cures Chagas' Disease in an Immunodeficient-Mouse Model of Infection  

Microsoft Academic Search

Chagas' disease, caused by the parasite Trypanosoma cruzi, remains the leading cause of cardiopathy in Latin America with about 12 million people infected. Classic clinical manifestations derive from infection of muscle cells leading to progressive cardiomyopathy, while some patients develop megacolon or megaesophagus. A very aggressive clinical course including fulminant meningoencephalitis has been reported in patients who contract Chagas' disease

Patricia S. Doyle; Yuan M. Zhou; Juan C. Engel; James H. McKerrow



Pre-Columbian Chagas disease in Brazil: Trypanosoma cruzi I in the archaeological remains of a human in Peruaçu Valley, Minas Gerais, Brazil  

Microsoft Academic Search

We evaluated the presence and distribution of Trypanosoma cruzi DNA in a mummy presenting with megacolon that was dated as approximately 560 ± 40 years old. The mummy was from the Peruaçu Valley in the state of Minas Gerais, Brazil. All samples were positive for T. cruzi minicircle DNA, demonstrating the presence and broad dis- semination of the parasite in

Alexandre Fernandes; Alena M Iñiguez; Valdirene S Lima; Sheila MF Mendonça de Souza; Luiz Fernando Ferreira; Ana Carolina P Vicente; Ana M Jansen



TTF-1 and RET promoter SNPs: regulation of RET transcription in Hirschsprung's disease  

Microsoft Academic Search

Single nucleotide polymorphisms (SNPs) of the coding regions of receptor tyrosine kinase gene (RET )a re associated with Hirschsprung's disease (HSCR, aganglionic megacolon). These SNPs, individually or com- bined, may act as a low penetrance susceptibility locus and\\/or be in linkage disequilibrium (LD) with another susceptibility locus located in RET regulatory regions. Because two RET promoter SNPs have been found

Raymond W. Ganster; Vincent C. H. Lui; Thomas Y. Y. Leon; Man-Ting So; Anson M. F. Lau; Ming Fu; Mai-Har Sham; Joanne Knight; Maria Stella Zannini; Pak C. Sham; Paul K. H. Tam



Strategies for the Care of Adults Hospitalized for Active Ulcerative Colitis  

PubMed Central

Ulcerative colitis is a chronic inflammatory disease of the colon; as many as 25% of patients with this disease require hospitalization. The goals of hospitalization are to assess disease severity, exclude infection, administer rapidly acting and highly effective medication regimens, and determine response. During the hospitalization, patients should be given venous thromboembolism prophylaxis and monitored for development of toxic megacolon. Patients who do not respond to intravenous corticosteroids should be considered for rescue therapy with infliximab or cyclosporine. Patients who are refractory to medical therapies or who develop toxic megacolon should be evaluated promptly for colectomy. Patients who do respond to medical therapies should be discharged on an appropriate maintenance regimen when they meet discharge criteria. We review practical evidence-based management principles and propose a day-by-day algorithm for managing patients hospitalized for ulcerative colitis. PMID:22835577

Pola, Suresh; Patel, Derek; Ramamoorthy, Sonia; McLemore, Elisabeth; Fahmy, Marianne; Rivera-Nieves, Jesus; Chang, John T; Evans, Elisabeth; Docherty, Michael; Talamini, Mark; Sandborn, William J



Human GFRA1: Cloning, Mapping, Genomic Structure, and Evaluation as a Candidate Gene for Hirschsprung Disease Susceptibility  

Microsoft Academic Search

Congenital aganglionic megacolon, commonly known as Hirschsprung disease (HSCR), is the most frequent cause of congenital bowel obstruction. Germline mutations in theRETreceptor tyrosine kinase have been shown to cause HSCR. Knockout mice forRETand for its ligand, glial cell line-derived neurotrophic factor (GDNF), exhibit both complete intestinal aganglionosis and renal defects. Recently, GDNF and GFRA1 (GDNF family receptor, also known as

Misha Angrist; Shuqian Jing; Stacey Bolk; Kimberly Bentley; Sudha Nallasamy; Marc Halushka; Gary M. Fox; Aravinda Chakravarti



Heterozygous endothelin receptor B (EDNRB) mutations in isolated Hirschsprung disease  

Microsoft Academic Search

Hirschsprung disease (HSCR, aganglionic megacolon) is a frequent congenital malformation regarded as a multigenic neurocristopathy. Two susceptibility genes have been recently identified in HSCR, namely the RET proto-oncogene and the endothelin B receptor (EDNRB) gene. Hitherto however, homozygosity for EDNRB mutations accounted for the HSCR-Waarden- burg syndrome (WS) association. Here, we report het- erozygous EDNRB missense mutations (G57S, R319W and

Jeanne Amiel; Tania Attié; Dominique Jan; Anna Pelet; Patrick Edery; Christelle Bidaud; Didier Lacombe; Paul Tam; Juliette Simeoni; Elisabeth Flori; Claire Nihoul-Fékété; Arnold Munnich; Stanislas Lyonnet



Mutations of the RET proto-oncogene in Hirschsprung's disease  

Microsoft Academic Search

HIRSCHSPRUNG'S disease (HSCR)1 is a common condition (1 in 5,000 live births) resulting in intestinal obstruction in neonates2 and megacolon in infants and adults3. This disease has been ascribed to the absence of autonomic ganglion cells, which are derived from the neural crest, in the terminal hindgut4. Segregation analyses have suggested incompletely penetrant dominant inheritance in familial HSCR5. Recently, a

Patrick Edery; Stanislas Lyonnet; Lois M. Mulligan; Anna Pelet; Eleanore Dow; Laurent Abel; Susan Holder; Claire Nihoul-Fékété; Bruce A. J. Ponder; Arnold Munnich



Giant colonic volvulus due to colonic pseudo-obstruction.  


Acute colonic pseudo-obstruction (ACPO), also known as Ogilvie's syndrome, is a clinical syndrome characterised by gross dilation of the caecum and right hemicolon, which sometimes extends to the sigmoid colon and rectum in the absence of an anatomic lesion in the intestinal lumen. It is characterised by impaired propulsion of contents of the gastrointestinal tract, which results in a clinical picture of intestinal obstruction. A careful examination of the markedly distended colon can exclude several colonic pathologies, including mechanical obstruction and other causes of toxic megacolon. ACPO can sometimes predispose or mimic colonic volvulus, especially in geriatric patients. PMID:25716038

Karaman, Kerem; Tanoglu, Alpaslan; Beyazit, Yavuz; Han, Ismet



Probiotics and Antibiotic-Associated Diarrhea and Clostridium difficile Infection  

NASA Astrophysics Data System (ADS)

Diarrhea is a common side effect of antibiotics. Antibiotics can cause diarrhea in 5-25% of individuals who take them but its occurrence is unpredictable. Diarrhea due to antibiotics is called antibiotic-associated diarrhea (AAD). Diarrhea may be mild and resolve when antibiotics are discontinued, or it may be more severe. The most severe form of AAD is caused by overgrowth of Clostridium difficile which can cause severe diarrhea, colitis, pseudomembranous colitis, or even fatal toxic megacolon. Rates of diarrhea vary with the specific antibiotic as well as with the individual susceptibility.

Surawicz, Christina M.


[Emergency anesthesia in a woman with mitochondrial neurogastrointestinal encephalopathy].  


Mitochondrial neurogastrointestinal encephalopathy (MNGIE) is characterized by leukoencephalopathy, peripheral neuropathy, ptosis, ophthalmoplegia, and gastrointestinal dysmotility. Mitochondrial myopathies are rare diseases and little is known of how to manage them when the patient requires anesthesia. We describe the anesthetic procedure used during emergency surgery for megacolon in a 26-year-old woman with MNGIE. Variables monitored were electrocardiogram, invasive arterial pressure, oxygen saturation by pulse oximetry, end-tidal carbon dioxide pressure, neuromuscular block, and depth of anesthesia (entropy). Rapid sequence induction was accomplished with midazolam, fentanyl, propofol, and rocuronium as an alternative to succinylcholine. Anesthesia was maintained with intravenous propofol; a second dose of the neuromuscular blocker was not required. No intraoperative problems developed and extubation was possible 2 hours after arrival in the postoperative critical care unit, once we had checked the level of block to confirm that reversion was not required. PMID:22279879

Ibáñez, C; Fernández-González, I



Gastrointestinal disorders of the cat.  


Several areas of feline gastroenterology deserve critical attention in the near future. For example, as compared with the dog, little is known about the various causes of malabsorptive disease in the cat. So frequently, intestinal biopsy samples reveal nothing more than intestinal thickening with fibrosis and nonspecific mild cellular infiltration, and the inciting cause is never determined. It is, perhaps, wrong to be critical about the use of the bark of Berberis vulgaris and the root of Rheum in modern feline gastroenterology, since most of us occasionally use unconventional therapies. It has been rumored that I have been known to advocate the daily addition of a tablespoon of pumpkin-pie filling to the food of cats suffering from recurrent constipation and acquired megacolon. The rumors are true, and colonic evacuation is sometimes promoted with the use of this unusual bulking agent after traditional drug therapy has failed. We all have our weaknesses! PMID:6359656

August, J R



Frameshift mutation of the zinc finger homeo box 1 B gene in syndromic corpus callosum agenesis (Mowat-Wilson syndrome).  


We report a girl who had Hirschsprung disease in association with distinct facial appearance, microcephaly, agenesis of the corpus callosum and mental retardation (Mowat-Wilson syndrome). Mutation analysis of the zinc finger homeo box 1 B (ZFHX1 B) gene revealed a de novo 7 bp deletion (TGGCCCC) at nucleotide 1773 (1773 delTGGCCCC) resulting in a frameshift and leading to a termination codon at amino acid residue 604 (604 X) in exon 8 C. The zinc finger homeo box 1 B (Smad interacting protein-1) is a transcription corepressor of Smad target genes with functions in the patterning of neural crest derived cells, CNS, and midline structures. Mutations in ZFHX1 B can lead to neurological disorders in addition to dysmorphic features, megacolon, and other malformations. PMID:14681759

Sztriha, L; Espinosa-Parrilla, Y; Gururaj, A; Amiel, J; Lyonnet, S; Gerami, S; Johansen, J G



Placement of a Port Catheter Through Collateral Veins in a Patient with Central Venous Occlusion  

SciTech Connect

Long-term utilization of central venous catheters (CVCs) for parenteral nutrition has a high incidence of central venous complications including infections, occlusions, and stenosis. We report the case of a 31-year-old woman presenting with a malabsorption caused by short gut syndrome due to congenital aganglionic megacolon. The patient developed a chronic occlusion of all central neck and femoral veins due to long-term use of multiple CVCs over more than 20 years. In patients with central venous occlusion and venous transformation, the implantation of a totally implanted port system by accessing collateral veins is an option to continue long-term parenteral nutrition when required. A 0.014-in. Whisper guidewire (Terumo, Tokyo) with high flexibility and steerability was chosen to maneuver and pass through the collateral veins. We suggest this approach to avoid unfavorable translumbar or transhepatic central venous access and to conserve the anatomically limited number of percutaneous access sites.

Teichgraeber, Ulf Karl-Martin, E-mail:; Streitparth, Florian, E-mail: florian.streitparth@charite.d [Charite Universitaetsmedizin Berlin, Institut fuer Diagnostische und Interventionelle Radiologie (Germany); Gebauer, Bernhard, E-mail: bernhard.gebauer@charite.d [Charite Universitaetsmedizin Berlin, Klinik fuer Strahlenheilkunde (Germany); Benter, Thomas, E-mail: Thomas.Benter@klinikum-rg.d [Elblandkliniken Riesa-Grossenhain gGmbH, Klinik fuer Innere Medizin II Haematologie/Onkologie und Gastroenterologie (Germany)



Case Report: Severe form of hemolytic-uremic syndrome with multiple organ failure in a child: a case report  

PubMed Central

Introduction: Hemolytic-uremic syndrome (HUS) is a leading cause of acute renal failure in infants and young children. It is traditionally defined as a triad of acute renal failure, hemolytic anemia and thrombocytopenia that occur within a week after prodromal hemorrhagic enterocolitis. Severe cases can also be presented by acute respiratory distress syndrome (ARDS), toxic megacolon with ileus, pancreatitis, central nervous system (CNS) disorders and multiple organ failure (MOF). Case presentation: A previously healthy 4-year old Caucasian girl developed acute renal failure, thrombocytopenia and hemolytic anemia following a short episode of abdominal pain and bloody diarrhea. By the end of the first week the diagnosis of the typical HUS was established. During the second week the disease progressed into MOF that included ileus, pancreatitis, hepatitis, coma and ARDS, accompanied by hemodynamic instability and extreme leukocytosis. Nonetheless, the girl made a complete recovery after one month of the disease. She was successfully treated in the intensive care unit and significant improvement was noticed after plasmapheresis and continuous veno-venous hemodialysis. Conclusions: Early start of plasmapheresis and meticulous supportive treatment in the intensive care unit, including renal placement therapy, may be the therapy of choice in severe cases of HUS presented by MOF. Monitoring of prognostic factors is important for early performance of appropriate diagnostic and therapeutical interventions. PMID:25075296

Mijatovic, Dino; Blagaic, Ana; Zupan, Zeljko



Diagnosis of Clostridium difficile Infection: an Ongoing Conundrum for Clinicians and for Clinical Laboratories  

PubMed Central

SUMMARY Clostridium difficile is a formidable nosocomial and community-acquired pathogen, causing clinical presentations ranging from asymptomatic colonization to self-limiting diarrhea to toxic megacolon and fulminant colitis. Since the early 2000s, the incidence of C. difficile disease has increased dramatically, and this is thought to be due to the emergence of new strain types. For many years, the mainstay of C. difficile disease diagnosis was enzyme immunoassays for detection of the C. difficile toxin(s), although it is now generally accepted that these assays lack sensitivity. A number of molecular assays are commercially available for the detection of C. difficile. This review covers the history and biology of C. difficile and provides an in-depth discussion of the laboratory methods used for the diagnosis of C. difficile infection (CDI). In addition, strain typing methods for C. difficile and the evolving epidemiology of colonization and infection with this organism are discussed. Finally, considerations for diagnosing C. difficile disease in special patient populations, such as children, oncology patients, transplant patients, and patients with inflammatory bowel disease, are described. As detection of C. difficile in clinical specimens does not always equate with disease, the diagnosis of C. difficile infection continues to be a challenge for both laboratories and clinicians. PMID:23824374

Carroll, Karen C.



Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs  

PubMed Central

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model. PMID:24271001

Nogueira-Paiva, Nívia Carolina; Fonseca, Kátia da Silva; Vieira, Paula Melo de Abreu; Diniz, Lívia Figueiredo; Caldas, Ivo Santana; de Moura, Sandra Aparecida Lima; Veloso, Vanja Maria; Guedes, Paulo Marcos da Matta; Tafuri, Washington Luiz; Bahia, Maria Terezinha; Carneiro, Cláudia Martins



Clostridium difficile-associated colitis.  

PubMed Central

OBJECTIVE: To review the basic microbiology, pathogenesis of disease, and diagnosis of the nosocomial pathogen Clostridium difficile and to examine therapies recommended by the Canadian Task Force on Preventive Health Care. QUALITY OF EVIDENCE MEDLINE: was searched using MeSH headings. Controlled trials for therapy were sought, but case-control studies and observational reviews were included. MAIN MESSAGE: Clostridium difficile causes approximately 20% of cases of diarrhea associated with antibiotics, including clindamycin and the second- and third-generation cephalosporins. Diarrhea is usually mild, but can be severe; extreme cases develop toxic megacolon. Diagnosis is dependent on demonstrating presence of clostridial toxin in stool specimens or of pseudomembranes through sigmoidoscopy. First-line therapy for C. difficile diarrhea is restricted to metronidazole. Second-line therapy for treatment failure is vancomycin. For relapse, a second course of metronidazole is recommended; tapering courses of vancomycin and probiotics are used for multiple recurrences. CONCLUSION: Clostridium difficile is an important nosocomial pathogen requiring prudent use of antibiotics and strict infection-control policies to prevent large health care costs. PMID:15597970

Hull, Mark W.; Beck, Paul L.



Acute abdominal complications following hip surgery.  


Hip surgeries are some of the most common and successful orthopedic procedures. Although rarely, abdominal complications do occur and are associated with unfavorable outcomes.We aimed to identify and describe the severe abdominal complications that appear in patients under-going elective or traumatic hip surgery. A four year retrospective electronic database research identified 408 elective primary hip replacements,51 hip revisions and 1040 intra and extracapsular proximal femur fractures. Out of these, three males and 4 females between 64 - 84 years old were identified to have developed acute abdominal complications: perforated acute ulcer (3),acute cholecystitis (2), volvulus (1), toxic megacolon with peritonitis (1) and acute colonic pseudo-obstruction (1).Complications debuted 3 - 10 days after index orthopedic surgery. Acute perioperative abdominal complications are rarely encountered during orthopedic surgery. When these do occur, they do so almost exclusively in patients with hippathology, comorbidities and most often lead to life threatening situations. We thus emphasize the need for early identification and appropriate management by both orthopedic and general surgery doctors in order to improve patient safety. PMID:24742414

Deleanu, B; Prejbeanu, R; Vermesan, D; Haragus, H; Icma, I; Predescu, V



Clostridium difficile infection among kidney transplant recipients: frequency, clinical presentation, and outcome.  


The objective of this study was to evaluate the frequency of Clostridium Difficile Infection (CDI) among kidney transplant recipients and describe the clinical picture in correlation with the presence of certain risk factors. We included kidney transplant recipients with a functioning graft, who were admitted during the period 1/2012-12/2013, and patients with ESRD who were admitted to undergo Kidney Transplantation (KTx) from a deceased or a living donor in the same period. Patients were screened following clinical indication of gastrointestinal infection. CDI diagnosis was based on a positive stool sample for CD toxins and stool culture. Within the period 2012-2013, we recorded 24 cases of CDI in 19 patients, accounting for a frequency of 5.4% of CDI in our population. In addition to diarrhea, 63.15% of the patients presented with fever, 31.25% with anorexia, while abdominal pain was a rare symptom (0.53%). None of the patients had ileus, bowel obstruction or megacolon. Fourteen patients (73.7%) had a history of recent exposure (15 days) to antimicrobial agents prior to the evolution of CDI symptoms. A relapse of the CDI infection was identified in five cases. CDI infection is a significant factor of morbidity in patients with KTx and should be considered in the clinical setting of diarrhea, even in cases with no exposure to antibiotic agents. PMID:25556694

Lionaki, Sophia; Panagiotellis, Konstantinos; Moris, Demetrios; Daikos, George; Psyhogiou, Mina; Vernadakis, Spiridon; Zavos, Georgios; Boletis, John N



Metallothionein-1 and nitric oxide expression are inversely correlated in a murine model of Chagas disease  

PubMed Central

Chagas disease, caused by Trypanosoma cruzi, represents an endemic among Latin America countries. The participation of free radicals, especially nitric oxide (NO), has been demonstrated in the pathophysiology of seropositive individuals with T. cruzi. In Chagas disease, increased NO contributes to the development of cardiomyopathy and megacolon. Metallothioneins (MTs) are efficient free radicals scavengers of NO in vitro and in vivo. Here, we developed a murine model of the chronic phase of Chagas disease using endemic T. cruzi RyCH1 in BALB/c mice, which were divided into four groups: infected non-treated (Inf), infected N-monomethyl-L-arginine treated (Inf L-NAME), non-infected L-NAME treated and non-infected vehicle-treated. We determined blood parasitaemia and NO levels, the extent of parasite nests in tissues and liver MT-I expression levels. It was observed that NO levels were increasing in Inf mice in a time-dependent manner. Inf L-NAME mice had fewer T. cruzi nests in cardiac and skeletal muscle with decreased blood NO levels at day 135 post infection. This affect was negatively correlated with an increase of MT-I expression (r = -0.8462, p < 0.0001). In conclusion, we determined that in Chagas disease, an unknown inhibitory mechanism reduces MT-I expression, allowing augmented NO levels. PMID:24676665

Gonzalez-Mejia, Martha Elba; Torres-Rasgado, Enrique; Porchia, Leonardo M; Salgado, Hilda Rosas; Totolhua, José-Luis; Ortega, Arturo; Hernández-Kelly, Luisa Clara Regina; Ruiz-Vivanco, Guadalupe; Báez-Duarte, Blanca G; Pérez-Fuentes, Ricardo



A novel corrective pullthrough surgery in a mouse model of Hirschsprung’s disease?  

PubMed Central

Background/Purpose The study aimed to develop a mouse model of post-pullthrough Hirschsprung’s disease that will allow investigation of mechanisms that cause postoperative complications. Methods We developed a novel microsurgical pullthrough operation on Balb/C mice and evaluated its effect on growth rate and stooling pattern. Histologic assessment of the pullthrough colon was performed. The pullthrough operation was then performed on Ednrb?/? mice that have aganglionic megacolon and Ednrb+/+ littermate controls, and the outcomes compared. Results The Balb/C pullthrough group had 97% survival at 1 week and 70% survival at 2 weeks. Body weight of the pullthrough animals declined 15% in the first week after surgery and subsequently normalized. The stooling pattern showed consistently softer stools in the pullthrough group, but no difference in frequency compared to controls. Histopathologic analyses 4 weeks postoperatively showed well-healed coloanal anastomoses. Two-week survival after pullthrough surgery in Ednrb?/? and Ednrb+/+ mice was 50.0%, and 69.2%, respectively (P = NS). Increased mortality in the Ednrb?/? mice was related to the technical challenge of performing microsurgery on smaller-sized mice with poor baseline health status. Conclusions Our microsurgical pullthrough operation in mice is feasible and allows systematic investigations into potential mechanisms mediating post-pullthrough complications and poor long-term results in mouse models of Hirschsprung’s disease. PMID:19361637

Zhao, Lifu; Cheng, Zhi; Dhall, Deepti; Doherty, Terence M.; Frykman, Philip K.



Fine structure mapping and deletion analysis of the murine piebald locus  

SciTech Connect

Piebald (s) is a recessive mutation that affects the development of two cell types of neural crest origin: melanocytes, responsible for pigment synthesis in the skin, and enteric ganglia, which innervate the lower bowel. As a result, mice carrying piebald mutations exhibit white spotting in the coat and aganglionic megacolon. Previously the gene had been localized to the distal half of mouse chromosome 14. To determine its precise location relative to molecular markers, an intersubspecific backcross was generated. Two anchor loci of chromosome 14, slaty and hypogonadal, in addition to simple sequence length repeat markers, were used to localize s to a 2-cM interval defined by the markers D14Mit38 and D14Mit42. The molecular markers were also used to characterize nine induced s alleles. Three of these mutations exhibited no deletions or rearrangements of the flanking markers, whereas the other six had two or more of these markers deleted. The extent of the deletions was found to be consistent with the severity of the homozygous phenotype. The location of deletion breakpoints in the induced alleles, coupled with the recombination breakpoints in the backcross progeny, provide useful molecular landmarks to define the location of the piebald gene.

Metallinos, D.L.; Tilghman, S.M. (Princeton Univ., NJ (United States)); Oppenheimer, A.J. (Harvard Medical School, Boston, MA (United States)); Rinchik, E.M.; Russell, L.B. (Oak Ridge National Laboratory, TN (United States)); Dietrich, W. (Whitehead Institute for Biomedical Research, Cambridge, MA (United States))



Familial form of hirschsprung disease: nucleotide sequence studies reveal point mutations in the RET proto-oncogene in two of six families but not in other candidate genes.  


Hirschsprung disease (HSCR; McKusick 142623) or aganglionic megacolon is a frequent (1 in 5,000 live births) heritable disorder of the enteric nervous system. By haplotyping with a variety of microsatellite markers, by amplifying all 20 exons of the RET proto-oncogene and by applying a direct DNA sequencing protocol, we have analyzed the DNA from HSCR patients in 6 different families. In one family with a joint occurrence of HSCR and FMTC (follicular medullary thyroid carcinoma), we have identified a mutation in codon 609 in one out of 6 cysteine residues encoded in exon 10 of the RET gene. This C609R point mutation has not previously been reported to cause HSCR. In 2 of the HSCR patients described here from different families, we have found a mutation in exon 2 (R77C) and a silent mutation in exon 3 (Y204Y), respectively, in the extracellular part of the RET proto-oncogene. In introns 2 and 17 of the RET proto-oncogene in 2 families, we have detected single nucleotide exchanges that are probably polymorphisms with unknown, if any, relations to HSCR. The DNA sequences of 5 further genes (GDNF, GDNFRalpha, EDN3, EDNRB, and NTN), that may contribute to the development of HSCR, have not shown mutations in the patients analyzed so far. In 2 of the reported families with several affected children and one grandchild, sequence analyses revealed no mutations in the coding regions of any of the candidate genes analyzed. PMID:10982477

Munnes, M; Fanaei, S; Schmitz, B; Muiznieks, I; Holschneider, A M; Doerfler, W



The Whirl CT Sign in Patient with Sigmoid Volvulus due Chagas' Disease.  


It is believed that sigmoid volvulus (SV) in Brazil is a frequent complication of megacolon caused by Chagas' disease (CD), differing in some characteristics from volvulus found in other countries. Bowel obstruction in patients with CD, principally when the cause is SV, may be sometimes difficult to diagnosis exclusively with plain abdominal radiograph. Fecaloma impacted in retossigmoidal area is one of the differential diagnoses. In addition, the huge amount of gas and feces, and distension of the colon normally increase the difficulty to make the correct diagnostic. The use of computer tomography (CT) scan can easy elucidate the picture of SV, and can be a great tool in cases of patients with CD and suspicion of this entity. A 62-year-old man showed bowel distention and stop disposal of gas for 5 days. He had previous diagnosis of CD. He also had been suffering from chronic constipation for several years, including impacted fecaloma, with the necessity of manual extraction. Plain abdominal radiographs showed an important colon dilatation and gross amount of feces in the sigmoid colon. Abdominal computer tomography sacan revealed dilated colon filled with feces, as well, the "whirl sign" composed of mesentery and twisted colon. When abdominal radiograph films reveal gross colonic dilatation of unknown etiology in patients with CD, a whirl sign on CT scans raises the possibility of colonic volvulus. PMID:24426419

da Fonseca, Leonardo Maciel; Caldeira, Daniel Adonai Machado



Discovery of LFF571: An Investigational Agent for Clostridium difficile Infection  

SciTech Connect

Clostridium difficile (C. difficile) is a Gram positive, anaerobic bacterium that infects the lumen of the large intestine and produces toxins. This results in a range of syndromes from mild diarrhea to severe toxic megacolon and death. Alarmingly, the prevalence and severity of C. difficile infection are increasing; thus, associated morbidity and mortality rates are rising. 4-Aminothiazolyl analogues of the antibiotic natural product GE2270 A (1) were designed, synthesized, and optimized for the treatment of C. difficile infection. The medicinal chemistry effort focused on enhancing aqueous solubility relative to that of the natural product and previous development candidates (2, 3) and improving antibacterial activity. Structure-activity relationships, cocrystallographic interactions, pharmacokinetics, and efficacy in animal models of infection were characterized. These studies identified a series of dicarboxylic acid derivatives, which enhanced solubility/efficacy profile by several orders of magnitude compared to previously studied compounds and led to the selection of LFF571 (4) as an investigational new drug for treating C. difficile infection.

LaMarche, Matthew J.; Leeds, Jennifer A.; Amaral, Adam; Brewer, Jason T.; Bushell, Simon M.; Deng, Gejing; Dewhurst, Janetta M.; Ding, Jian; Dzink-Fox, JoAnne; Gamber, Gabriel; Jain, Akash; Lee, Kwangho; Lee, Lac; Lister, Troy; McKenney, David; Mullin, Steve; Osborne, Colin; Palestrant, Deborah; Patane, Michael A.; Rann, Elin M.; Sachdeva, Meena; Shao, Jian; Tiamfook, Stacey; Trzasko, Anna; Whitehead, Lewis; Yifru, Aregahegn; Yu, Donghui; Yan, Wanlin; Zhu, Qingming (Novartis)



Biologics in the management of ulcerative colitis – comparative safety and efficacy of TNF-? antagonists  

PubMed Central

Ulcerative colitis can cause debilitating symptoms and complications such as colonic strictures, colonic dysplasia, colorectal cancer, and toxic megacolon or perforation. Goals of treatment in ulcerative colitis include resolution of gastrointestinal symptoms, healing of colonic mucosa, and prevention of disease complications. Our treatment armamentarium has expanded dramatically over the past 10 years, and we now have multiple biologic agents approved for the treatment of moderate-severe disease, in addition to conventional therapies such as 5-aminosalicylates, thiopurines, and corticosteroids. In this review, we will provide a detailed discussion of the three tumor necrosis factor-alpha (TNF-?) inhibitors currently approved for treatment of ulcerative colitis: infliximab, adalimumab, and golimumab. All three agents are effective for inducing and maintaining clinical response and remission in patients with ulcerative colitis, and they have comparable safety profiles. There are no head-to-head trials comparing their efficacy, and the choice of agent is most often based on insurance coverage, route of administration, and patient preference. Combination therapy with an immunomodulator is proven to be more effective than anti-TNF monotherapy, and patients who lose response to an anti-TNF agent should undergo dose intensification in order to regain clinical response. Despite therapeutic optimization, a significant percentage of patients will not achieve clinical remission with anti-TNF agents, and so newer therapies are on the horizon. PMID:25609972

Fausel, Rebecca; Afzali, Anita



Severe hypercalcaemia and colon ischaemia: dehydration as an unusual cause?  


Hypercalcaemia is an emergency with severe consequences. Dehydration can be an uncommon cause of hypercalcaemia, as seen in this case. A 63-year-old woman with type 2 diabetes mellitus, hypothyroidism and osteoporosis, was admitted to the emergency room with abdominal distension and vomiting for 24?h. Initial evaluation was Hg 18.5?g/dL, Htc 56.2%, creatinine 2?mg/dL, metabolic acidaemia, lactate 8.3?mmol/L, anion gap 19, total Ca(2+) 17.7?mg/dL and PO4+ 6.6?mg/dL. CT revealed colonic distension without obstruction or ischaemia. Renal replacement therapy and pamidronate were initiated. The patient's clinical condition deteriorated with septic shock in the context of toxic megacolon and she underwent an emergency subtotal colectomy (10?kg). Hypercalcaemia was corrected in 24?h with aggressive fluid replacement (8?L NaCl 0.9% first 12?h), with a reduction of total Ca(2+) to 8.2?mg/dL. Other causes of hypercalcaemia were excluded. 'Hypercalcaemic crisis' secondary to severe acute dehydration is not mentioned in the literature. PMID:25809432

Fernandes, Liliana Gil; Ferreira, Nuno Ribeiro; Cardiga, Rosa; Póvoa, Pedro



The immunology of experimental Chagas' disease. IV. Production of lesions in rabbits similar to those of chronic Chagas' disease in man.  

PubMed Central

Eight rabbits that received a single inoculation of trypomastigotes of a virulent strain of Trypanosoma cruzi first developed a transient acute illness associated with parasitemia; later, 4 of these rabbits died with chronic myocarditis and/or with megacolon in the absence of demonstrable parasitemia or encysted parasites in tissues. Two of these rabbits with chronic myocarditis died unexpectedly. Three of the inoculated rabbits that survived the infection were sacrificed 18 months later and showed similar but less severe microscopic lesions. The remaining rabbit is alive and well at the time of writing (26 months) with negative blood cultures but high hemagglutinating antibody titers to T. cruzi antigens. The natural course of T. cruzi infection in rabbits and the lesions observed postmortem are similar to those recorded for humans with chronic Chagas' disease. Multiple injections of particulate subcellular antigens of T. cruzi in rabbits resulted in microscopic lesions similar to those observed in rabbits that survived protozoan infection. Sera of rabbits inoculated with T. cruzi have antibodies to striated and smooth muscle structures. However, evidence provided in this and in other experiments strongly suggest that the lesions of chronic Chagas' disease are produced by delayed hypersensitivity to T. cruzi antigens. Images Figure 1 Figure 2 Figures 3-4 Figure 5 Figure 6 Figure 7 PMID:808136

Teixeira, A. R.; Teixeira, M. L.; Santos-Buch, C. A.



Current approaches to the management of new-onset ulcerative colitis  

PubMed Central

Ulcerative colitis (UC) is an idiopathic, inflammatory gastrointestinal disease of the colon. As a chronic condition, UC follows a relapsing and remitting course with medical maintenance during periods of quiescent disease and appropriate escalation of therapy during times of flare. Initial treatment strategies must not only take into account current clinical presentation (with specific regard for extent and severity of disease activity) but must also take into consideration treatment options for the long-term. The following review offers an approach to new-onset UC with a focus on early treatment strategies. An introduction to the disease entity is provided along with an approach to initial diagnosis. Stratification of patients based on clinical parameters, disease extent, and severity of illness is paramount to determining course of therapy. Frequent assessments are required to determine clinical response, and treatment intensification may be warranted if expected improvement goals are not appropriately reached. Mild-to- moderate UC can be managed with aminosalicylates, mesalamine, and topical corticosteroids with oral corticosteroids reserved for unresponsive cases. Moderate-to-severe UC generally requires oral or intravenous corticosteroids in the short-term with consideration of long-term management options such as biologic agents (as initial therapy or in transition from steroids) or thiopurines (as bridging therapy). Patients with severe or fulminant UC who are recalcitrant to medical therapy or who develop disease complications (such as toxic megacolon) should be considered for colectomy. Early surgical referral in severe or refractory UC is crucial, and colectomy may be a life-saving procedure. The authors provide a comprehensive evidence-based approach to current treatment options for new-onset UC with discussion of long-term therapeutic efficacy and safety, patient-centered perspectives including quality of life and medication compliance, and future directions in related inflammatory bowel disease care. PMID:24872716

Marchioni Beery, Renée; Kane, Sunanda



In vitro and in vivo effects on neural crest stem cell differentiation by conditional activation of Runx1 short isoform and its effect on neuropathic pain behavior  

PubMed Central

Introduction Runx1, a Runt domain transcription factor, controls the differentiation of nociceptors that express the neurotrophin receptor Ret, regulates the expression of many ion channels and receptors, and controls the lamina-specific innervation pattern of nociceptive afferents in the spinal cord. Moreover, mice lacking Runx1 exhibit specific defects in thermal and neuropathic pain. We investigated whether conditional activation of Runx1 short isoform (Runx1a), which lacks a transcription activation domain, influences differentiation of neural crest stem cells (NCSCs) in vitro and in vivo during development and whether postnatal Runx1a activation affects the sensitivity to neuropathic pain. Methods We activated ectopic expression of Runx1a in cultured NCSCs using the Tet-ON gene regulatory system during the formation of neurospheres and analyzed the proportion of neurons and glial cells originating from NCSCs. In in vivo experiments we applied doxycycline (DOX) to pregnant mice (days 8–11), i.e. when NCSCs actively migrate, and examined the phenotype of offsprings. We also examined whether DOX-induced activation of Runx1a in adult mice affects their sensitivity to mechanical stimulation following a constriction injury of the sciatic nerve. Results Ectopic Runx1a expression in cultured NCSCs resulted in predominantly glial differentiation. Offsprings in which Runx1a had been activated showed retarded growth and displayed megacolon, pigment defects, and dystrophic dorsal root ganglia. In the neuropathic pain model, the threshold for mechanical sensitivity was markedly increased following activation of Runx1a. Conclusion These data suggest that Runx1a has a specific role in NCSC development and that modulation of Runx1a activity may reduce mechanical hypersensitivity associated with neuropathic pain. PMID:20187849

Kanaykina, Nadezda; Abelson, Klas; King, Dale; Liakhovitskaia, Anna; Schreiner, Silke; Wegner, Michael



Surveillance snapshot of Clostridium difficile infection in hospitals across Queensland detects binary toxin producing ribotype UK 244.  


In North America and Europe, the binary toxin positive Clostridium difficile strains of the ribotypes 027 and 078 have been associated with death, toxic megacolon and other adverse outcomes. Following an increase in C. difficile infections (CDIs) in Queensland, a prevalence study involving 175 hospitals was undertaken in early 2012, identifying 168 cases of CDI over a 2 month period. Patient demographics and clinical characteristics were recorded, and C. difficile isolates were ribotyped and tested for the presence of binary toxin genes. Most patients (106/168, 63.1%) were aged over 60 years. Overall, 98 (58.3%) developed symptoms after hospitalisation; 89 cases (53.0%) developed symptoms more than 48 hours after admission. Furthermore, 27 of the 62 (67.7%) patients who developed symptoms in the community ad been hospitalised within the last 3 months. Thirteen of the 168 (7.7%) cases identified had severe disease, resulting in admission to the Intensive Care Unit or death within 30 days of the onset of symptoms. The 3 most common ribotypes isolated were UK 002 (22.9%), UK 014 (13.3%) and the binary toxin-positive ribotype UK 244 (8.4%). The only other binary toxin positive ribotype isolated was UK 078 (n = 1). Of concern was the detection of the binary toxin positive ribotype UK 244, which has recently been described in other parts of Australia and New Zealand. No isolates were of the international epidemic clone of ribotype UK 027, although ribotype UK 244 is genetically related to this clone. Further studies are required to track the epidemiology of ribotype UK 244 in Australia and New Zealand. Commun Dis Intell 2014;38(4):E279-E284. PMID:25631588

Huber, Charlotte A; Hall, Lisa; Foster, Nikki F; Gray, Mareeka; Allen, Michelle; Richardson, Leisha J; Robson, Jennifer; Vohra, Renu; Schlebusch, Sanmarie; George, Narelle; Nimmo, Graeme R; Riley, Thomas V; Paterson, David L



Dosage Effects of Cohesin Regulatory Factor PDS5 on Mammalian Development: Implications for Cohesinopathies  

PubMed Central

Cornelia de Lange syndrome (CdLS), a disorder caused by mutations in cohesion proteins, is characterized by multisystem developmental abnormalities. PDS5, a cohesion protein, is important for proper chromosome segregation in lower organisms and has two homologues in vertebrates (PDS5A and PDS5B). Pds5B mutant mice have developmental abnormalities resembling CdLS; however the role of Pds5A in mammals and the association of PDS5 proteins with CdLS are unknown. To delineate genetic interactions between Pds5A and Pds5B and explore mechanisms underlying phenotypic variability, we generated Pds5A-deficient mice. Curiously, these mice exhibit multiple abnormalities that were previously observed in Pds5B-deficient mice, including cleft palate, skeletal patterning defects, growth retardation, congenital heart defects and delayed migration of enteric neuron precursors. They also frequently display renal agenesis, an abnormality not observed in Pds5B?/? mice. While Pds5A?/? and Pds5B?/? mice die at birth, embryos harboring 3 mutant Pds5 alleles die between E11.5 and E12.5 most likely of heart failure, indicating that total Pds5 gene dosage is critical for normal development. In addition, characterization of these compound homozygous-heterozygous mice revealed a severe abnormality in lens formation that does not occur in either Pds5A?/? or Pds5B?/? mice. We further identified a functional missense mutation (R1292Q) in the PDS5B DNA-binding domain in a familial case of CdLS, in which affected individuals also develop megacolon. This study shows that PDS5A and PDS5B functions other than those involving chromosomal dynamics are important for normal development, highlights the sensitivity of key developmental processes on PDS5 signaling, and provides mechanistic insights into how PDS5 mutations may lead to CdLS. PMID:19412548

Zhang, Bin; Chang, Jufang; Fu, Ming; Huang, Jie; Kashyap, Rakesh; Salavaggione, Ezequiel; Jain, Sanjay; Shashikant, Kulkarni; Deardorff, Matthew A.; Uzielli, Maria L. Giovannucci; Dorsett, Dale; Beebe, David C.; Jay, Patrick Y.; Heuckeroth, Robert O.; Krantz, Ian; Milbrandt, Jeffrey



Specific serum microRNA profile in the molecular diagnosis of Hirschsprung's disease  

PubMed Central

Hirschsprung's disease (HSCR), a congenital gastrointestinal disorder, is one of the most common causes of neonatal bowel obstruction. Without an early screening and diagnosis, some patients develop serious complications, such as toxic megacolon or acute enterocolitis. We sought to identify specific serum microRNAs (miRNAs) that can serve as novel early, non-invasive screening signature and then to test their specificity and sensitivity in diagnosing Hirschsprung's disease. We obtained serum samples from 95 HSCR cases and 104 matched controls. An initial screening of miRNA expression was performed through TaqMan Low Density Array. The candidate miRNAs were validated by individual reverse transcription quantitative real-time PCR arranged in the training and a two-stage validation set. Additional double-blind testing was performed in 23 patients with clinically suspected HSCR to evaluate the diagnostic value and accuracy of the serum miRNA profile in predicting HSCR. Following a multi-stage evaluation approach, five miRNAs were significantly increased in HSCR cases compared with controls. The areas under the receiver operating characteristic (ROC) curve of this five-serum miRNA signature were 0.895, 0.893 and 0.925 in training set and two validation sets, respectively. The accuracy rate of the five-miRNA profile as HSCR signature was 82.6%, which, in the double-blind testing set, was markedly higher than that of contrast enema (70%), the most commonly used test performed to diagnose HSCR. Our results indicate that a five-serum miRNA signature may be linked to HSCR, representing a potential, novel, non-invasive diagnostic approach for early screening of HSCR. PMID:24974861

Tang, Weibing; Li, Hongxing; Tang, Junwei; Wu, Wei; Qin, Jingjing; Lei, Hao; Cai, Peng; Huo, Weiwei; Li, Bo; Rehan, Virender; Xu, Xiaoqun; Geng, Qiming; Zhang, Hongwei; Xia, Yankai



C. difficile 630?erm Spo0A Regulates Sporulation, but Does Not Contribute to Toxin Production, by Direct High-Affinity Binding to Target DNA  

PubMed Central

Clostridium difficile is a Gram positive, anaerobic bacterium that can form highly resistant endospores. The bacterium is the causative agent of C. difficile infection (CDI), for which the symptoms can range from a mild diarrhea to potentially fatal pseudomembranous colitis and toxic megacolon. Endospore formation in Firmicutes, including C. difficile, is governed by the key regulator for sporulation, Spo0A. In Bacillus subtilis, this transcription factor is also directly or indirectly involved in various other cellular processes. Here, we report that C. difficile Spo0A shows a high degree of similarity to the well characterized B. subtilis protein and recognizes a similar binding sequence. We find that the laboratory strain C. difficile 630?erm contains an 18bp-duplication near the DNA-binding domain compared to its ancestral strain 630. In vitro binding assays using purified C-terminal DNA binding domain of the C. difficile Spo0A protein demonstrate direct binding to DNA upstream of spo0A and sigH, early sporulation genes and several other putative targets. In vitro binding assays suggest that the gene encoding the major clostridial toxin TcdB may be a direct target of Spo0A, but supernatant derived from a spo0A negative strain was no less toxic towards Vero cells than that obtained from a wild type strain, in contrast to previous reports. These results identify for the first time direct (putative) targets of the Spo0A protein in C. difficile and make a positive effect of Spo0A on production of the large clostridial toxins unlikely. PMID:23119071

Rosenbusch, Katharina E.; Bakker, Dennis; Kuijper, Ed J.; Smits, Wiep Klaas



Current approaches to the management of new-onset ulcerative colitis.  


Ulcerative colitis (UC) is an idiopathic, inflammatory gastrointestinal disease of the colon. As a chronic condition, UC follows a relapsing and remitting course with medical maintenance during periods of quiescent disease and appropriate escalation of therapy during times of flare. Initial treatment strategies must not only take into account current clinical presentation (with specific regard for extent and severity of disease activity) but must also take into consideration treatment options for the long-term. The following review offers an approach to new-onset UC with a focus on early treatment strategies. An introduction to the disease entity is provided along with an approach to initial diagnosis. Stratification of patients based on clinical parameters, disease extent, and severity of illness is paramount to determining course of therapy. Frequent assessments are required to determine clinical response, and treatment intensification may be warranted if expected improvement goals are not appropriately reached. Mild-to- moderate UC can be managed with aminosalicylates, mesalamine, and topical corticosteroids with oral corticosteroids reserved for unresponsive cases. Moderate-to-severe UC generally requires oral or intravenous corticosteroids in the short-term with consideration of long-term management options such as biologic agents (as initial therapy or in transition from steroids) or thiopurines (as bridging therapy). Patients with severe or fulminant UC who are recalcitrant to medical therapy or who develop disease complications (such as toxic megacolon) should be considered for colectomy. Early surgical referral in severe or refractory UC is crucial, and colectomy may be a life-saving procedure. The authors provide a comprehensive evidence-based approach to current treatment options for new-onset UC with discussion of long-term therapeutic efficacy and safety, patient-centered perspectives including quality of life and medication compliance, and future directions in related inflammatory bowel disease care. PMID:24872716

Marchioni Beery, Renée; Kane, Sunanda



Analysis of human chromosome 21 for a locus conferring susceptibility to Hirschsprung Disease  

SciTech Connect

It has been estimated that approximately 5% of patients diagnosed with Hirschsprung disease (HSCR), or aganglionic megacolon, have trisomy 21. Since the incidence of Hirschsprung disease is 1/5000 live births and the incidence of trisomy 21 is approximately 1/1000 live births, the observed occurrence of HSCR in trisomy 21 is fifty times higher than expected. We propose that at least one locus on chromosome 21 predisposes to HSCR. Although at fifty times elevated risk, only 1% of Down Syndrome cases have HSCR. Thus additional genes or genetic events are necessary for HSCR to manifest in patients with trisomy 21. Based on segregation analysis, Badner et al. postulated that recessive genes may be responsible for up to 80% of HSCR. We postulate that at least one such gene is on chromosome 21 and increased homozygosity for common recessive HSCR mutations may be one cause for the elevated risk of HSCR in cases of trisomy 21. To map such a chromosome 21 locus, we are searching for segments of human chromosome 21 which are identical by descent from the parent in whom non-disjunction occurred. These segments will arise either from meiosis I (followed by a crossover between the centromere and the locus) or from meiosis II (followed by no crossovers). Nine nuclear families with a proband diagnosed with HSCR and Down Syndrome have been genotyped for 18 microsatellite markers spanning human chromosome 21q. In all nine cases analyzed thus far, trisomy 21 resulted from maternal non-disjunction at meiosis I. At this point no single IBD region is apparent. Therefore, additional families are being ascertained and additional markers at high density are being genotyped to map the HSCR locus.

Bolk, S.; Duggan, D.J.; Chakravarti, A. [Case Western Reserve Univ., Cleveland, OH (United States)



Murine model of Hirschsprung-associated enterocolitis II: Surgical correction of aganglionosis does not eliminate enterocolitis?  

PubMed Central

Background Hirschsprung disease (HD) results from aganglionosis of the colon, is linked to acute and chronic enterocolitis (known as Hirschsprung-associated enterocolitis) despite successful corrective surgery, and can lead to bacteremia and even death. The genetic and molecular mechanisms underlying these disorders are largely unknown. Methods We developed a microsurgical corrective pull-through procedure in mice, and applied that to Ednrb?/? mice, which manifest aganglionic megacolon that is very similar to HD. Wild-type littermates (Ednrb+/+) also underwent identical surgery. At prespecified time points postoperatively, mice were sacrificed, and histopathologic analyses of intestinal inflammation were performed. Mice of both genotypes were sacrificed after the postoperative recovery period to determine if corrective surgery itself caused inflammation. Stooling patterns were assessed as well to determine if intestinal function normalized after surgery. Results: There was no difference in histopathological enterocolitis scores after recovery from surgery. Stooling patterns in Ednrb?/? and Ednrb+/+ mice were similar postoperatively, suggesting normalization of intestinal function. However, with time, approximately 40% of Ednrb?/? mice developed clinical illness consistent with enterocolitis. No control (Ednrb+/+) mice developed clinical enterocolitis. Histopathological enterocolitis scores in the 40% of Ednrb?/? mice that developed clinical enterocolitis postoperatively were significantly worse than those of healthy postoperative Ednrb?/? mice. In contrast, none of the Ednrb+/+ control mice exhibited postoperative long-term inflammation. Conclusions Microsurgical pull-through operation in Ednrb?/? mice produces a mouse model that closely resembles key features of Hirschsprung-associated enterocolitis, enabling controlled study of genetic and molecular mechanisms in Ednrb?/? mice and other genotypes that produce similar phenotypes. PMID:20105605

Zhao, Lifu; Dhall, Deepti; Cheng, Zhi; Wang, Hanlin L.; Doherty, Terence M.; Bresee, Catherine; Frykman, Philip K.



Clinical Severity of Clostridium difficile PCR Ribotype 027: A Case-Case Study  

PubMed Central

Background Clostridium difficile is a leading infectious cause of health care associated diarrhoea. Several industrialised countries have reported increased C. difficile infections and outbreaks, which have been attributed to the emergent PCR ribotype 027 strain. Methods and Findings We conducted a case-case study to compare severity of C. difficile disease for patients with 027 versus non-027 ribotypes. We retrospectively collected clinical information about 123/136 patients with C. difficile infections admitted to hospitals in the East of England region in 2006 and from whom stool isolates were cultured and ribotyped as part of an earlier national survey. We defined severe C. difficile disease as having one or more of shock, paralytic ileus, pseudo membranous colitis or toxic megacolon. Patient median age was 83 years old (range 3 to 98, interquartile range 75 to 89), 86% were prescribed antibiotics in the eight weeks before illness onset, 41% had ribotype 027 and 30-day all cause mortality during hospital admission was 21%. Severe disease occurred in 24% (95%CI 13% to 37%) and 17% (95%CI 9% to 27%) of patients with PCR ribotype 027 and non-027 ribotypes respectively. In a multivariable model, ribotype 027 was not associated with severe disease after adjusting for sex, discharge from hospital prior to 60 days of current admission, gastroenteritis on admission, number of initiator antibiotics for C. difficile disease, and hospital where the patient was admitted. Conclusions Our study found no evidence to support previous assertions that ribotype 027 is more virulent than other PCR ribotypes. This finding raises questions about the contribution of this strain to the recent increase in C. difficile disease throughout North America and Europe. PMID:18350149

Morgan, Oliver W.; Rodrigues, Boaventura; Elston, Tony; Verlander, Neville Q.; Brown, Derek F. J.; Brazier, Jonathan; Reacher, Mark



Clostridium difficile associated infection, diarrhea and colitis  

PubMed Central

A new, hypervirulent strain of Clostridium difficile, called NAP1/BI/027, has been implicated in C. difficile outbreaks associated with increased morbidity and mortality since the early 2000s. The epidemic strain is resistant to fluoroquinolones in vitro, which was infrequent prior to 2001. The name of this strain reflects its characteristics, demonstrated by different typing methods: pulsed-field gel electrophoresis (NAP1), restriction endonuclease analysis (BI) and polymerase chain reaction (027). In 2004 and 2005, the US Centers for Disease Control and Prevention (CDC) emphasized that the risk of C. difficile-associated diarrhea (CDAD) is increased, not only by the usual factors, including antibiotic exposure, but also gastrointestinal surgery/manipulation, prolonged length of stay in a healthcare setting, serious underlying illness, immune-compromising conditions, and aging. Patients on proton pump inhibitors (PPIs) have an elevated risk, as do peripartum women and heart transplant recipients. Before 2002, toxic megacolon in C. difficile-associated colitis (CDAC), was rare, but its incidence has increased dramatically. Up to two-thirds of hospitalized patients may be infected with C. difficile. Asymptomatic carriers admitted to healthcare facilities can transmit the organism to other susceptible patients, thereby becoming vectors. Fulminant colitis is reported more frequently during outbreaks of C. difficile infection in patients with inflammatory bowel disease (IBD). C. difficile infection with IBD carries a higher mortality than without underlying IBD. This article reviews the latest information on C. difficile infection, including presentation, vulnerable hosts and choice of antibiotics, alternative therapies, and probiotics and immunotherapy. We review contact precautions for patients with known or suspected C. difficile-associated disease. Healthcare institutions require accurate and rapid diagnosis for early detection of possible outbreaks, to initiate specific therapy and implement effective control measures. A comprehensive C. difficile infection control management rapid response team (RRT) is recommended for each health care facility. A communication network between RRTs is recommended, in coordination with each country’s department of health. Our aim is to convey a comprehensive source of information and to guide healthcare professionals in the difficult decisions that they face when caring for these oftentimes very ill patients. PMID:19340897

Hookman, Perry; Barkin, Jamie S



Multiple endocrine neoplasia type 1 (MEN1) and type 4 (MEN4)  

PubMed Central

Multiple endocrine neoplasia (MEN) is characterized by the occurrence of tumors involving two or more endocrine glands within a single patient. Four major forms of MEN, which are autosomal dominant disorders, are recognized and referred to as: MEN type 1 (MEN1), due to menin mutations; MEN2 (previously MEN2A) due to mutations of a tyrosine kinase receptor encoded by the rearranged during transfection (RET) protoncogene; MEN3 (previously MEN2B) due to RET mutations; and MEN4 due to cyclin-dependent kinase inhibitor (CDNK1B) mutations. Each MEN type is associated with the occurrence of specific tumors. Thus, MEN1 is characterized by the occurrence of parathyroid, pancreatic islet and anterior pituitary tumors; MEN2 is characterized by the occurrence of medullary thyroid carcinoma (MTC) in association with phaeochromocytoma and parathyroid tumors; MEN3 is characterized by the occurrence of MTC and phaeochromocytoma in association with a marfanoid habitus, mucosal neuromas, medullated corneal fibers and intestinal autonomic ganglion dysfunction, leading to megacolon; and MEN4, which is also referred to as MENX, is characterized by the occurrence of parathyroid and anterior pituitary tumors in possible association with tumors of the adrenals, kidneys, and reproductive organs. This review will focus on the clinical and molecular details of the MEN1 and MEN4 syndromes. The gene causing MEN1 is located on chromosome 11q13, and encodes a 610 amino-acid protein, menin, which has functions in cell division, genome stability, and transcription regulation. Menin, which acts as scaffold protein, may increase or decrease gene expression by epigenetic regulation of gene expression via histone methylation. Thus, menin by forming a subunit of the mixed lineage leukemia (MLL) complexes that trimethylate histone H3 at lysine 4 (H3K4), facilitates activation of transcriptional activity in target genes such as cyclin-dependent kinase (CDK) inhibitors; and by interacting with the suppressor of variegation 3–9 homolog family protein (SUV39H1) to mediate H3K methylation, thereby silencing transcriptional activity of target genes. MEN1-associated tumors harbor germline and somatic mutations, consistent with Knudson’s two-hit hypothesis. Genetic diagnosis to identify individuals with germline MEN1 mutations has facilitated appropriate targeting of clinical, biochemical and radiological screening for this high risk group of patients for whom earlier implementation of treatments can then be considered. MEN4 is caused by heterozygous mutations of CDNK1B which encodes the 196 amino-acid CDK1 p27Kip1, which is activated by H3K4 methylation. PMID:23933118

Thakker, Rajesh V.



Role of surgery in severe ulcerative colitis in the era of medical rescue therapy  

PubMed Central

Despite the growing use of medical salvage therapy, colectomy has remained a cornerstone in managing acute severe ulcerative colitis (ASC) both in children and in adults. Colectomy should be regarded as a life saving procedure in ASC, and must be seriously considered in any steroid-refractory patient. However, colectomy is not a cure for the disease but rather the substitution of a large problem with smaller problems, including fecal incontinence, pouchitis, irritable pouch syndrome, cuffitis, anastomotic ulcer and stenosis, missed or de-novo Crohn’s disease and, in young females, reduced fecundity. This notion has led to the widespread practice of offering medical salvage therapy before colectomy in most patients without surgical abdomen or toxic megacolon. Medical salvage therapies which have proved effective in the clinical trial setting include cyclosporine, tacrolimus and infliximab, which seem equally effective in the short term. Validated predictive rules can identify a subset of patients who will eventually fail corticosteroid therapy after only 3-5 d of steroid therapy with an accuracy of 85%-95%. This accuracy is sufficiently high for initiating medical therapy, but usually not colectomy, early in the admission without delaying colectomy if required. This approach has reduced the colectomy rate in ASC from 30%-70% in the past to 10%-20% nowadays, and the mortality rate from over 70% in the 1930s to about 1%. In general, restorative proctocolectomy (ileoanal pouch or ileal pouch-anal anastomosis), especially the J-pouch, is preferred over straight pull-through (ileo-anal) or ileo-rectal anastomosis, which may still be considered in young females concerned about infertility. Colectomy in the acute severe colitis setting, is usually performed in three steps due to the severity of the inflammation, concurrent steroid treatment and the generally reduced clinical condition. The first surgical step involves colectomy and constructing an ileal stoma, the second - constructing the pouch and the third - closing the stoma. This review focuses on the role of surgical treatment in ulcerative colitis in the era of medical rescue therapy. PMID:22876035

Dayan, Bosmat; Turner, Dan