Factors associated with incomplete colonoscopy at a Japanese academic hospital

AIM:To evaluate significant risk factors for incomplete colonoscopy at a Japanese academic hospital.METHODS:A total of 11812 consecutive Japanese people were identified who underwent a colonoscopy at an academic hospital.A multiple logistic regression model was used to evaluate retrospectively the significant risk factors for incomplete colonoscopy.RESULTS:The cecal intubation rate was 95.0%.By univariate analysis,age,female sex,poor bowel cleansing,and a history of abdominal or pelvic surgery were significant risk factors for incomplete colonoscopy(P<0.001).Moreover,age-and sex-adjusted analysis showed that significant risk factors for incomplete colonoscopy were female sex(OR=1.38,95%CI:1.17-1.64,P=0.0002),age≥60 years old(OR=1.44,95%CI:1.22-1.71,P<0.0001),a history of prior abdominal or pelvic surgery(OR=1.55,95%CI:1.28-1.86,P<0.0001),poor bowel cleansing(OR=4.64,95%CI:3.69-5.84,P<0.0001),and inflammatory bowel disease(IBD)(OR=1.48,95%CI:1.13-1.95,P=0.0048).In Japanese men,by age-adjusted analysis,IBD(OR=1.69,95%CI:1.18-2.43,P=0.005)was an independent risk factor for incomplete colonoscopy.CONCLUSION:Several characteristics in the Japanese population were identified that could predict technical difficulty with colonoscopy.     

Distinct cellular expressions of creatine synthetic enzyme GAMT and creatine kinases uCK-Mi and CK-B suggest a novel neuron-glial relationship for brain energy homeostasis

The creatine/phosphocreatine shuttle system, as catalysed reversibly by creatine kinases, is thought to be essential for the storing and buffering of high phosphate-bound energy in tissues with high energy demand. In the present study, we aimed to clarify the cellular system of creatine biosynthesis and its energy metabolism in the mouse brain by immunohistochemistry for creatine biosynthetic enzyme S-adenosylmethionine:guanidinoacetate N-methyltransferase (GAMT), ubiquitous mitochondrial creatine kinase (uCK-Mi) and brain-type cytoplasmic creatine kinase (CK-B). GAMT was expressed highly in oligodendrocytes and olfactory ensheathing glia and moderately in astrocytes, whereas GAMT was very low in neurons and microglia. By contrast, uCK-Mi was expressed selectively in neurons and localized in their mitochondria in dendrites, cell bodies, axons and terminals. The distinct and almost complementary distribution of GAMT and uCK-Mi suggests that the creatine in neuronal mitochondria is derived not only from the circulation, but also from local glial cells associated with these neuronal elements. By contrast, CK-B was selective to astrocytes among glial populations, and was exclusive to inhibitory neurons among neuronal populations. Interestingly, these cells with high CK-B immunoreactivity are known to be highly resistant to acute energy loss, such as hypoxia and hypoglycemia. Considering that phosphocreatine generates ATP much faster than the processes of glycolysis and oxidative phosphorylation, the highly regulated cellular expressions of creatine biosynthetic and metabolic enzymes suggest that the creatine/phosphocreatine shuttle system plays a role in brain energy homeostasis through a novel neuron-glial relationship.     

1. Fatty liver and non-alcoholic steatohepatitis

Although steatohepatitis can be induced by an excessive intake of alcohol, it can also arise through various other causes, in which case it is known as non-alcoholic fatty liver disease (NAFLD). NAFLD is classified into two categories:simple fatty liver with a favorable clinical outcome, and non-alcoholic steatohepatitis (NASH), which is intractable and progressive. Recently in Japan, there has been an increase in the number of individuals at risk of lifestyle-related diseases, due to increased insulin resistance and visceral fat obesity. The metabolic syndrome (MS) is associated with several risk factors for atherosclerosis, including diabetes mellitus (DM), hypertension, and hyperlipidemia. Visceral fat obesity is the prime cause of NASH in the liver, and is therefore considered to be one of the phenotypic features of MS. Furthermore, most chronic liver diseases are associated with hepatitis C virus (HCV) infection. Fatty degeneration of hepatocytes is often observed in the liver of HCV-infected individuals, and results from viral suppression of mitochondrial beta-oxidation of fatty acid. The natural outcome of HCV infection is worse in patients with lifestyle-related high insulin resistance and visceral fat obesity. In this review, we describe the recent advances in research on progressive liver diseases that are the result of fat accumulation in the liver, with special reference to MS.     

MEK Activation Suppresses CPT11-Induced Apoptosis in Rat Intestinal Epithelial Cells Through a COX-2-Dependent Mechanism

Resistance to chemotherapeutic agents is one of the distinct features of cancer cells. We evaluate the role of activated MEK-ERK signaling in Camptotecin/irinotecan (CPT-11)-induced cell death using constitutively activated MEK1-transfected normal rat intestinal epithelial cells (IEC-caMEK cells). A CPT-11-induced inhibitory concentration of 50% was determined by WST assay. Apoptosis was evaluated by DNA staining and fragmented DNA analysis. Protein expressions were analyzed by western blotting. We also examined the role of cyclooxygenase-2 in the cell systems. IEC-caMEK cells possessed survival advantages compared to control cells. Apoptosis was remarkably suppressed in IEC-caMEK cells. Western blot analysis revealed increased expression of Bcl-2, Bcl-xL, Mcl-1, and COX-2 and decreased expression of Bak in IEC-caMEK cells. The COX-2 selective inhibitor ameliorated the antiapoptotic nature of IEC-caMEK cells. MEK activation suppressed CPT-11-induced apoptosis in IEC-caMEK cells via a COX-2- dependent mechanism. Therefore, MEK-ERK signaling may contribute to the drug-resistant nature of cancer cells.     

Factors influencing insulin secretion after pancreatoduodenectomy

Preoperative patients with periampullary cancer had a higher mean Σ IRI value than that of normal controls, and also had a delayed pattern of insulin response and a lower insulinogenic index during oral-GTT. Σ IRI levels after pancreatoduodenectomy were similar to those of normal controls when the pancreatic remnants were histologically intact at the time of surgery. Postoperative Σ IRI levels could not be predicted based on the extent of histological fibrosis of the distal pancreas at the time of surgery. Patency of pancreatojejunostomy was obtained with the modified Warren's method in 39 out of 40 patients, and Σ IRI levels were maintained up to 5 years postoperatively. No significant difference was found in Σ IRI levels between pancreatoduodenectomised patients with the conventional Roux-en-Y procedure and those with the inverted Roux-en-Y with jejunal interposition. The mean insulin peak value and Σ IRI level were higher in pancreatoduodenectomised patients than in normal controls, and higher in gastrectomised patients than in pancreatoduodenectomised patients. Pancreatoduodenectomy with superior mesenteric arterial dissection resulted in remarkably low Σ IRI levels.     

Common null variant, Arg192Stop, in a G-protein coupled receptor, olfactory receptor 1B1, associated with decreased serum cholinesterase activity

Aim: Non-functioning single nucleotide polymorphisms (nSNPs) that result in premature termination codons, that is null-alleles of the respective genes, may have phenotypic effects on clinical parameters. We conducted association studies involving several G-protein coupled receptors (GPCRs) that harbor nSNPs, using clinical parameters of liver function in a general population consisting of 2969 Japanese adults. Methods: SNP typings were performed with TaqMan and Invader assays. Quantitative associations between genotypes and clinical parameters were analyzed by analysis of variance. Linkage disequilibrium (LD) was tested by Haploview Version 3.3. Haplotype-based association was performed using the haplo.stats program. Results: A significant correlation (P = 0.0057) was identified between serum cholinesterase activity (CHE) and an nSNP (Arg192Stop) in the olfactory receptor (OR) 1B1 gene, a member of the GPCR gene family. This nSNP was associated with decreased serum CHE (P = 0.0013). LD analysis based on eight selected SNPs at the locus revealed three LD blocks. The Arg192Stop nSNP was located on the second LD block, which covered one-third of the 3'-portion of the gene. Conclusion: These results suggested that the null-allele of OR1B1 might affect metabolism of serum cholinesterase in carriers of this nSNP.     

A Study of Malignant Bile Duct Stenosis Using Percutaneous Transhepatic Cholangioscopy

Abstract: From June, 1987 to November, 1989, 11 patients with malignant bile duct stenosis, which was later confirmed by surgery or autopsy, were examined by percutaneous transhepatic cholangioscopy (PTCS) and by an endoscopic biopsy. The endoscopic findings obtained with the usual observation methods and methylene blue staining and the histological findings of the biopsy specimens were compared. A fine vascular proliferation was seen in all of the patients and a granular appearance was noted in patients with carcinoma of the major papilla. The papillary appearance was noted in one case each of pancreatic carcinoma, bile duct carcinoma and carcinoma of the major papilla. Marginal protrusion was not noted in patients with pancreatic carcinoma. A distorted narrow segment was seen only in cases of pancreatic carcinoma. The presence of a granular appearance indicated that the carcinoma was exposed on the surface. A high degree of fine vascular proliferation and a papillary appearance tended to indicate a carcinoma which invaded mainly into the fibromuscular layer without invasion of the mucosa. The methylene blue staining method was simple and effective for better visualization of the surface structure of the abnormal area, normal mucosa and the border zone.     

Labour analgesia guided by echocardiography in a parturient with primary dilated cardiomyopathy

PURPOSE: To evaluate the effects of intrathecal analgesics on cardiac function during labour analgesia using echocardiography in a parturient with idiopathic dilated cardiomyopathy (DCM). CLINICAL FEATURES: Induction of labour was planned in a 35-yr-old primiparous woman suffering from DCM. In order to stabilize hemodynamics in this patient, we induced continuous spinal analgesia with an infusion of fentanyl and epinephrine. Although her analgesia was well maintained for three hours during the first stage of labour, the patient complained of pain towards the second stage of labour. At this point, we administered bupivacaine intrathecally to alleviate her pain. Transthoracic echocardiography showed that the left ventricular end-diastolic and systolic dimensions, as well as the ejection fraction were not impaired by use of these analgesic medications. CONCLUSION: Measurement of left ventricular dimensions by echocardiography allowed us to monitor the patient's response to intrathecal analgesic medications. In this patient with DCM, analgesia with intrathecal fentanyl and bupivacaine was well tolerated.     

Mouse reduced in osteosclerosis transporter functions as an organic anion transporter 3 and is localized at abluminal membrane of blood-brain barrier

The "reduced in osteosclerosis" transporter (Roct), which shows decreased expression in the osteosclerosis (oc) mutant mouse, has high homology with rat and human organic anion transporter 3 (OAT3). However, its transport properties and involvement in bone turnover are poorly understood. Here, we examined Roct-mediated transport using a Xenopus laevis oocyte expression system. Roct-expressing oocytes exhibited uptake of [(3)H]estrone sulfate, [(3)H]p-aminohippuric acid, [(3)H]benzylpenicillin, [(3)H]estradiol 17beta-glucronide, [(3)H]indoxyl sulfate, [(14)C]indomethacin, [(3)H]homovanillic acid, [(3)H]cimetidine, [(14)C]glutarate, [(14)C]salicylic acid, and [(3)H]methotrexate. Furthermore, the uptake of [(3)H]benzylpenicillin by Roct coexpressed with Na(+)-dicarboxylate cotransporter was trans-stimulated by glutarate preloading, and [(3)H]estrone sulfate uptake showed a similar tendency, suggesting that Roct is a dicarboxylate exchanger. [(3)H]Benzylpenicillin uptake by Roct was inhibited by OAT3 substrates and inhibitors, and by sulfate or glucuronide conjugates, and compounds involved in bone turnover. Roct mRNA is expressed abundantly in the kidney and was also detected in the brain, choroid plexus, and eye. Immunohistochemical analysis revealed that Roct is localized in brain capillary endothelial cells. These results indicate that the transport properties and tissue distribution of Roct are similar to those of OAT3, suggesting that Roct functions as mouse OAT3. Because Roct is expressed in the kidney and at the blood-brain barrier, it may play a role in the excretion of substrates such as conjugates and bone turnover factors.