Clinical associations and risk factors for bleeding from colonic angiectasia: a case-controlled study.

AIM: A case-controlled study was performed to investigate the association of colonic angiectasia with other conditions and to identify risk factors for bleeding. METHOD: Information was collected from all patients who underwent colonoscopy at our hospital between January 2008 and December 2010. Data on 90 individuals with angiectasia [58 men; median age 69 (26-92) years] were compared with those of 180 individuals without angiectasia, matched for gender and age. RESULTS: Multivariate analysis showed that occult gastrointestinal bleeding [odds ratio (OR) 2.523; 95% confidence interval (CI) 1.238-5.142], liver cirrhosis (OR 13.195; 95% CI 3.502-49.711), chronic renal failure (OR 6.796; 95% CI 1.598-28.904) and valvular heart disease (OR 6.425; 95% CI 1.028-40.165) were identified as significant predictors of the presence of colonic angiectasia. Eight patients were diagnosed with bleeding from angiectasia. Cardiovascular disease (OR 22.047; 95% CI 1.063-457.345) and multiple angiectasias (P-value 0.0019) were identified as significant risk factors for active bleeding. Medication and a large size were not associated with an increased risk of bleeding. CONCLUSION: The presence of colonic angiectasia was associated with valvular heart disease, liver cirrhosis and chronic renal failure. Valvular heart disease and multiple lesions increased the risk of bleeding.

Efficacy of percutaneous endoscopic gastro-jejunostomy (PEG-J) decompression therapy for patients with chronic intestinal pseudo-obstruction (CIPO).

BACKGROUNDS: Chronic intestinal pseudo-obstruction (CIPO) is an intractable rare digestive disease manifesting persistent small bowel distension without any mechanical cause. Intestinal decompression is a key treatment, but conventional method including a trans-nasal small intestinal tube is invasive and painful. Therefore, a less invasive and tolerable new decompression method is urgently desired. We conducted a pilot study and assessed the efficacy and safety of percutaneous endoscopic gastro-jejunostomy (PEG-J) decompression therapy in CIPO patients. METHODS: Seven definitive CIPO patients (2 males and 5 females) were enrolled. All patients received PEG-J decompression therapy. The number of days with any abdominal symptoms in a month (NODASIM), body mass index (BMI), serum albumin level (Alb), and small intestinal volume before and after PEG-J were compared in all patients. RESULTS: Percutaneous endoscopic gastro-jejunostomy was well tolerated and oral intake improved in all patients. NODASIM has significantly decreased (24.3 vs 9.3 days/months) and BMI/Alb have significantly increased (14.9 vs 17.2 kg/m2 and 2.6 vs 3.8 g/dL, respectively), whereas total volume of the small intestine has not significantly reduced (4.05 vs 2.59 L, P=.18). Reflux esophagitis and chemical dermatitis were observed in one case but was successfully treated conservatively. CONCLUSIONS & INFERENCES: Percutaneous endoscopic gastro-jejunostomy decompression therapy can contribute greatly to improvement of abdominal symptoms and nutritional status in CIPO patients. Although sufficient attention should be paid to acid reflux symptoms, PEG-J has the potential to be a non-invasive novel decompression therapy for CIPO available at home. However, accumulation of more CIPO patients and long-term observation are needed (UMIN000017574).

Unfolding and refolding of Escherichia coli chaperonin GroES is expressed by a three-state model.

The guanidine-hydrochloride (Gdn-HCl) induced unfolding and refolding characteristics of the co-chaperonin GroES from Escherichia coli, a homoheptamer of subunit molecular mass 10,000 Da, were studied by using intrinsic fluorescence, 1-anilino-8-naphthalene sulfonate (ANS) binding, and size-exclusion HPLC. When monitored by tyrosine fluorescence, the unfolding reaction of GroES consisted of a single transition, with a transition midpoint at around 1.0 M Gdn-HCl. Interestingly, however, ANS binding and size-exclusion HPLC experiments strongly suggested the existence of an intermediate state in the transition. In order to confirm the existence of an intermediate state between the native heptameric and unfolded monomeric states, a tryptophan residue was introduced into the interface of GroES subunits as a fluorescent probe. The unfolding reaction of GroES I48W as monitored by tryptophyl fluorescence showed a single transition curve with a transition midpoint at 0.5 M Gdn-HCl. This unfolding transition curve as well as the refolding kinetics were dependent on the concentration of GroES protein. CD spectrum and size-exclusion HPLC experiments demonstrated that the intermediates assumed a partially folded conformation at around 0.5 M Gdn-HCl. The refolding of GroES protein from 3 M Gdn-HCl was probed functionally by measuring the extent of inhibition of GroEL ATPase activity and the enhancement of lactate dehydrogenase refolding yields in the presence of GroEL and ADP. These results clearly demonstrated that the GroES heptamer first dissociated to monomers and then unfolded completely upon increasing the concentration of Gdn-HCl, and that both transitions were reversible. From the thermodynamic analysis of the dissociation reaction, it was found that the partially folded monomer was only marginally stable and that the stability of GroES protein is governed mostly by the association of the subunits.

Single molecular observation of the interaction of GroEL with substrate proteins.

To understand the mechanism of GroEL-assisted protein folding, we observed the interaction of fluorescence-labeled GroEL with fluorescence-labeled substrate proteins at the single molecule level by total internal reflection fluorescence microscopy. GroEL with a A133C mutation in the equatorial domain was labeled with a fluorescent dye, tetramethylrhodamine. As substrate proteins, we used the largely denatured and partly denatured forms of bovine beta-lactoglobulin, both labeled with another fluorescent dye, Cy5. The complexes formed by GroEL with these substrates were characterized by size-exclusion gel chromatography. The recovered complexes were then observed by fluorescence microscopy. For both substrates, agreement of the fluorescent spots for tetramethylrhodamine and Cy5 indicated formation of the complex at the single molecule level. Similar observation of macroscopic binding by size-exclusion chromatography and microscopic binding by the fluorescence microscopy was done for the folding intermediate of Cy5-labeled bovine rhodanese. The fluorescence microscopy opens a new avenue for studying the interaction of GroEL with substrate proteins.

Influence of sumatriptan on gastric accommodation and on antral contraction in healthy subjects assessed by ultrasonography.

BACKGROUND: Oral sumatriptan administration has been reported to delay gastric emptying after liquid meals. The aim of this study was to determine whether delayed gastric emptying is caused by enhanced gastric accommodation, impaired antral contractions, or both using ultrasonography. METHODS: Ten healthy volunteers were enrolled in this randomized two-way crossover study. After overnight fasting, the subjects received the liquid meal 60 min after ingesting a 50 mg sumatriptan tablet with 50 mL of water or 50 mL of water alone (control). The cross-sectional area of the proximal stomach was measured in a supine position after every 100 mL. The frequency and amplitude of the antral contractions were measured in a slightly backward sitting position. The intragastric distribution of the liquid meal was assessed by calculating the proximal stomach/distal stomach ratio (prox/distal ratio). KEY RESULTS: The cross-sectional area after drinking 100, 200, and 300 mL of the liquid meal (oral sumatriptan vs control) was 34.49 vs 15.11 cm(2) (P = 0.0051), 48.00 vs 30.61 cm(2) (P = 0.0166), and 58.67 vs 47.19 cm(2) (P = 0.0125), respectively. There was no significant difference in the amplitude of contractions, contraction cycle, motility index, and prox/distal ratio (97.15 vs 97.93%, P = 0.0745; 19.42 vs 19.5 s, P= 0.8590; and 887.58 vs 889.22, P = 0.5751; 9.75 vs 8.41, P = 0.8785; respectively). CONCLUSIONS & INFERENCES: Oral sumatriptan administration enhanced gastric accommodation after the ingestion of liquid nutrients, but had no significant effect on antral contractions or intragastric distribution in healthy subjects.

Gastric varices with remarkable collateral veins in valpronic Acid-induced chronic pancreatitis.

Valproic acid (VPA) is a commonly prescribed and approved treatment for epilepsy, including Angelman syndrome, throughout the world. However, the long-term administration of drugs like VPA is associated with the possible development of gastric varices and splenic obstruction as a result of chronic pancreatitis. Such cases can be difficult to treat using endoscopy or interventional radiology because of hemodynamic abnormalities; therefore, surgical treatment is often necessary.

Noninvasive assessment of liver fibrosis by measurement of stiffness in patients with nonalcoholic fatty liver disease (NAFLD).

BACKGROUND: Liver fibrosis is the main predictor of the progression of nonalcoholic fatty liver disease. Transient elastography (FibroScan), which measures liver stiffness, is a novel, noninvasive method to assess liver fibrosis. AIM: We investigated the usefulness of liver stiffness measurement in the evaluation of liver fibrosis in nonalcoholic fatty liver disease patients. STUDY POPULATION: A total of 97 nonalcoholic fatty liver disease patients. METHODS: Transient elastography was performed for liver stiffness measurement in 97 nonalcoholic fatty liver disease patients. And the relationship between histological parameters and liver stiffness measurement was studied by multivariate analysis. Moreover, we investigated the relationship between liver stiffness measurement and the serum levels of hyaluronic acid and type IV collagen 7s domain. RESULTS: The liver stiffness was well correlated with the stage of liver fibrosis (Kruskal-Wallis test p < 0.0001). The areas under the receiver-operating characteristic curves were 0.927 for > or = F1, 0.865 for > or = F2, 0.904 for > or = F3, 0.991 for > or = F4. Only fibrosis stage was correlated significantly with liver stiffness measurement by multiple regression analysis. Liver stiffness was also strongly correlated with the serum levels of type IV collagen 7s domain (r = 0.525, p < 0.0001) and hyaluronic acid (r = 0.457, p < 0.0001). CONCLUSIONS: Our results show a significant correlation between liver stiffness measurement and fibrosis stage in nonalcoholic fatty liver disease patients, as confirmed by the results of liver biopsy, which remains the gold standard for evaluation of the severity of liver fibrosis in patients with nonalcoholic steatohepatitis.

Functional communications between the apical and equatorial domains of GroEL through the intermediate domain.

The Escherichia coli GroEL subunit consists of three domains with distinct functional roles. To understand the role of each of the three domains, the effects of mutating a single residue in each domain (Y203C at the apical, T89W at the equatorial, and C138W at the intermediate domain) were studied in detail, using three different enzymes (enolase, lactate dehydrogenase, and rhodanese) as refolding substrates. By analyzing the effects of each mutation, a transfer of signals was detected between the apical domain and the equatorial domain. A signal initiated by the equatorial domain triggers the release of polypeptide from the apical domain. This trigger was independent of nucleotide hydrolysis, as demonstrated using an ATPase-deficient mutant, and, also, the conditions for successful release of polypeptide could be modified by a mutation in the apical domain, suggesting that the polypeptide release mechanism of GroEL is governed by chaperonin-target affinities. Interestingly, a reciprocal signal from the apical domain was suggested to occur, which triggered nucleotide hydrolysis in the equatorial domain. This signal was disrupted by a mutation in the intermediate domain to create a novel ternary complex in which GroES and refolding protein are simultaneously bound in a stable ternary complex devoid of ATPase activity. These results point to a multitude of signals which govern the overall chaperonin mechanism.