Shinya Fukunishi

Identification of malignant hyperthermia-susceptible ryanodine receptor type 1 gene (RYR1) mutations in a child who died in a car after exposure to a high environmental temperature

Malignant hyperthermia (MH) is a genetic disorder of skeletal muscle in susceptible individuals that is triggered by exposure to anesthetic agents, and can cause death. Mutations in the ryanodine receptor type 1 gene (RYR1) are associated with MH-susceptibility. MH is also triggered in susceptible individuals by severe exercise in hot conditions or by overheating in infants. Here, we report a case of a child, 2years, 9months of age, who was left in a car and exposed to a high environmental temperature. The child was suspected to have died of heat stroke by autopsy examinations. Postmortem mutation analysis revealed that the child possessed two distinct RYR1 mutations. Since each mutation had previously been identified in a separate MH-susceptible patient, MH-susceptibility with over-response to the environmental high temperature might have occurred in this child with RYR1 mutations. These findings suggest that a MH-susceptible case may have died with a presumed diagnosis of heat stroke at autopsy.

An immunosuppressive subtype of neutrophils identified in patients with hepatocellular carcinoma

Functional disorders of various immune cells have been reported in hepatocellular carcinoma (HCC) patients. Recently, distinct subsets of neutrophils (polymorphonuclear leukocytes, PMN) have been identified in hosts with enhanced or impaired cell-mediated immunity. In this study, therefore, plasma factors and PMN from HCC patients were immunobiologically investigated. Plasma neopterin and CCL17 levels were measured by ELISA in 95 HCC patients. Peripheral PMN were isolated from each HCC patient and tested for CCL2 or CCL3 production by ELISA and flow cytometry. The results showed elevated plasma neopterin levels in HCC patients, while CCL17 levels decreased in correlation with tumor size. PMN from HCC patients produced CCL2, while PMN from healthy subjects did not. Moreover, CCL2 production by PMN was significantly increased in proportion to tumor load. When HCC patients were divided into two groups based on CCL2 produced by PMN, the survival rate of the CCL2 high group was significantly lower than that for other patients. While CCL3 production by PMN was also significantly increased in HCC patients, their CCL3 production did not correlate with tumor load and survival. The CCL2/CCL3 ratio in culture fluids of each PMN was also increased in proportion to tumor size. These results suggest that cell-mediated immunity may be impaired in advanced HCC patients. Moreover, distinct PMN subsets may exist in the peripheral blood of HCC patients. These PMN subsets, especially CCL2-producing PMN, may be involved in tumor extension and the survival outcomes for HCC patients.

Comparison of the clinical impact of endoscopic ultrasound-guided choledochoduodenostomy and hepaticogastrostomy for bile duct obstruction with duodenal obstruction

BACKGROUND AND STUDY AIM To date, only a few reports with small numbers of patients have described double stenting (biliary and duodenal), in particular endoscopic ultrasound (EUS)-guided biliary drainage, for patients with obstructive jaundice. In addition, no reports have sought to determine which EUS-guided biliary drainage route has better outcomes. The aim of the current study was to investigate adverse events and stent patency in patients who underwent EUS-guided biliary drainage and duodenal stenting. PATIENTS AND METHODS Patients who were admitted to the Osaka Medical College with obstructive jaundice caused by lower biliary obstruction and duodenal obstruction due to malignant tumor between June 2012 and April 2014 were retrospectively enrolled in the study. RESULTS A total of 39 patients were enrolled in the study; 13 underwent EUS-guided choledochoduodenostomy (EUS-CDS), and 26 underwent EUS-guided hepaticogastrostomy (EUS-HGS). Adjusted analyses for covariates using propensity scores showed that the EUS-HGS group had significantly longer stent patency than the EUS-CDS group (duodenal stent patency: median 113 vs. 34 days; hazard ratio [HR] 0.415, 95 % confidence interval [CI] 0.175 - 0.984; P = 0.046; biliary stent patency: median 133 vs. 37 days; HR 0.391, 95 %CI 0.156 - 0.981; P = 0.045). On logistic regression analysis, only EUS-CDS was associated with adverse events, in particular reflux cholangitis (OR 10.285, 95 %CI 1.686 - 62.733; P = 0.012). CONCLUSION In cases of obstructive jaundice with duodenal obstruction, EUS-HGS may be better than EUS-CDS, with longer stent patency and fewer adverse events.

Lipopolysaccharides accelerate hepatic steatosis in the development of nonalcoholic fatty liver disease in Zucker rats

Nonalcoholic fatty liver disease (NAFLD) can develop into end-stage disease that includes cryptogenic cirrhosis and hepatocellular carcinoma. Bacterial endotoxin, for example lipopolysaccharide (LPS), plays an important role in the pathogenesis of NAFLD. The aim of this study was to assess the role of LPS in the development of NAFLD. Twenty-one male Zucker (fa/fa) rats were divided into three groups: rats fed for twelve weeks on a diet rich in disaccharide (D12 group), rats similarly managed but treated with LPS (LPS group), and those on the same diet for 24 weeks (D24 group). Histological examination demonstrated that this protocol induced hepatic steatosis in the LPS and D24 groups. Significant, marked accumulation of lipid droplets was observed in the LPS group, compared with the D24 group. Rats from the LPS group showed a decrease in plasma adiponectin levels, an increase in plasma leptin levels, and greater expression of FAS and SREBP-1c mRNA in the liver, compared with rats from the D24 group. These finding coincided with histological findings. We therefore suggest that LPS may accelerate the progression of hepatic steatosis.

Stent length is impact factor associated with stent patency in endoscopic ultrasound-guided hepaticogastrostomy.

Despite high technical and functional success rates with endoscopic ultrasound‐guided hepaticogastrostomy (EUS‐HGS), rates of adverse events have also been high. No reports have focused on EUS‐HGS alone with a large sample size about predictors of stent patency. The present study examined predictors of stent patency in patients who underwent EUS‐HGS.

Development of Fibrosis in Nonalcoholic Steatosis through Combination of a Synthetic Diet Rich in Disaccharide and Low-Dose Lipopolysaccharides in the Livers of Zucker (fa/fa) Rats

Nonalcoholic steatohepatitis (NASH) can develop into end-stage disease such as cryptogenic cirrhosis and hepatocellular carcinoma. Hence, it is important to understand the pathogenesis of NASH. In general, the “two-hit theory” has prevailed as a pathogenic mechanism of NASH. According to this theory, lipopolysaccharides (LPS) contained in normal portal blood are the “second hit,” but their role is not completely understood. Based on this theory, we evaluated the role of LPS in NASH pathogenesis. For the first hit to develop metabolic abnormalities, a synthetic diet rich in disaccharide (synthetic diet: 12.1 cal% disaccharide) was fed to Zucker (fa/fa) rats for 12 weeks. For the second hit, 100 µg/kg LPS was injected intraperitoneally once daily for 2 weeks. Synthetic diet-fed rats treated with LPS showed an increase in the triglyceride content and higher expression of profibrogenic mRNAs in the liver. Plasma alanine aminotransferase levels were significantly elevated using this protocol. Furthermore, histological examination demonstrated that this protocol induced mild hepatic fibrosis and focal necrosis in the livers of all rats. Synthetic diet-fed Zucker (fa/fa) rats treated with LPS could be useful for understanding the development of hepatic fibrosis in the two-hit theory.

Identification of an ethnic-specific variant (V207M) of the KCNQ1 cardiac potassium channel gene in sudden unexplained death and implications from a knock-in mouse model

We performed mutation analysis for genes implicated in long QT syndrome (KCNQ1, KCNH2, and SCN5A) in 17 sudden unexplained death autopsy cases. Single-strand conformation polymorphism and subsequent DNA sequencing analyses revealed that in one case, there was a variant, V207M of KCNQ1, a gene encoding a cardiac potassium channel. This case, a 40-year-old African male, was shown to have a heterozygous missense mutation (V207M), which has been previously reported to be ethnic-specific. The heterozygous V207M mutation was found in one case (0.23%) of 444 alleles from African individuals. We developed a knock-in mouse model carrier of the Kcnq1-V206M mutation, the mouse equivalent to the KCNQ1-V207M mutation identified in the victim. Significant prolongation of QT intervals was observed in the Kcnq1V206M/V206M mice. These findings suggest that the KCNQ1-V207M mutation might be pathogenic and might have been associated with the cause of death in the present case.

Combined treatment with dipeptidyl peptidase 4 (DPP4) inhibitor sitagliptin and elemental diets reduced indomethacin-induced intestinal injury in rats via the increase of mucosal glucagon-like peptide-2 concentration

The gut incretin glucagon-like peptide-1 (GLP-1) and the intestinotropic hormone GLP-2 are released from enteroendocrine L cells in response to ingested nutrients. Treatment with an exogenous GLP-2 analogue increases intestinal villous mass and prevents intestinal injury. Since GLP-2 is rapidly degraded by dipeptidyl peptidase 4 (DPP4), DPP4 inhibition may be an effective treatment for intestinal ulcers. We measured mRNA expression and DPP enzymatic activity in intestinal segments. Mucosal DPP activity and GLP concentrations were measured after administration of the DPP4 inhibitor sitagliptin (STG). Small intestinal ulcers were induced by indomethacin (IM) injection. STG was given before IM treatment, or orally administered after IM treatment with or without an elemental diet (ED). DPP4 mRNA expression and enzymatic activity were high in the jejunum and ileum. STG dose-dependently suppressed ileal mucosal enzyme activity. Treatment with STG prior to IM reduced small intestinal ulcer scores. Combined treatment with STG and ED accelerated intestinal ulcer healing, accompanied by increased mucosal GLP-2 concentrations. The reduction of ulcers by ED and STG was reversed by co-administration of the GLP-2 receptor antagonist. DPP4 inhibition combined with luminal nutrients, which up-regulate mucosal concentrations of GLP-2, may be an effective therapy for the treatment of small intestinal ulcers.

Placement of a 6 mm, fully covered metal stent for main pancreatic head duct stricture due to chronic pancreatitis: a pilot study (with video).

Background: Temporary stent placement is widely performed for pancreatic duct stenosis due to chronic pancreatitis. A fully covered self-expandable metal stent (FCSEMS) has a larger diameter, and therefore longer stent patency, and the effect of expansion of the main pancreatic duct stricture may be obtained. However, if stent migration upstream occurs, stent removal is extremely difficult. In addition, because of the diameter gap between the FCSEMS and the main pancreatic duct, stent-induced ductal change may occur. To prevent these adverse events, the technical feasibility, safety and efficacy of the placement of a novel 6 mm diameter FCSEMS with a long suture, to facilitate its removal in cases of stent migration upstream, were evaluated in a pilot study. Methods: Between December 2014 and August 2015, symptomatic chronic pancreatitis patients with abdominal pain and a main pancreatic head duct stricture were enrolled. Stent placement for main pancreatic duct stricture was performed under endoscopic retrograde cholangiopancreatography (ERCP) guidance and stent removal was performed within 6 months. Results: A total of 13 patients were retrospectively enrolled in this study. Metal stent insertion was successfully performed in all patients and clinical success was high (12/13, 92%). As adverse events, stent migration upstream was seen in two patients. Another 11 patients successfully underwent stent removal without any adverse events. During follow up (median 258 days), 2 patients still underwent pancreatic duct stenting because of continuing main pancreatic duct stricture. Conclusion: In conclusion, this novel FCSEMS is acceptable for stent placement in cases of chronic pancreatitis with a main pancreatic duct stricture.

EUS-guided cholecystoduodenostomy for acute cholecystitis with an anti-stent migration and anti-food impaction system; a pilot study

Background: Recently, endoscopic ultrasound-guided gall bladder drainage (EUS-GBD) has been reported using a self-expandable metallic stent. To prevent stent migration and food flowing into the common bile duct through the cystic duct, we perform a novel EUS-guided cholecystoduodenostomy. The aim of our study was to evaluate the safety and feasibility of EUS-guided cholecystoduodenostomy with an anti-stent migration and anti-food impaction system. Methods: A total of 16 consecutive patients who underwent EUS-guided cholecystoduodenostomy for acute cholecystitis were included in this study. Results: Technical and clinical success was obtained in all patients. The median procedure time was 26.9 min (range 19–42 min). Median follow-up time was 181.5 days (range 18–604 days), and in this time, recurrence of acute cholecystitis was not seen in all patients. Adverse events such as stent migration and cholangitis were not seen in any patients, although pneumoperitoneum was seen in one patient. Conclusion: Our technique may be favorable and effective for the prevention of adverse events on EUS-GBD.