Covered versus uncovered wallstent for malignant extrahepatic biliary obstruction: a cohort comparative analysis.

BACKGROUND & AIMS: We examined the use of both covered and uncovered Wallstents in patients with malignant extrahepatic biliary obstruction to determine whether use of covered Wallstents prolonged stent patency without increasing procedure-related complications. METHODS: Commercially available silicone-covered Wallstents were prospectively evaluated in 98 patients who underwent insertion from December 2002-December 2004. Those data were compared with data obtained by retrospectively studying 108 consecutive patients who underwent endoscopic insertion of uncovered Wallstents between January 2000-November 2002, and for whom accurate and complete follow-up details were available. RESULTS: The mean stent patency was similar for both groups, 148.9 days (range, 3-667 days) for covered Wallstents and 143.5 days (3-910 days) for uncovered Wallstents (P = .531). The 2 groups also did not significantly differ in terms of cumulative stent patency according to the Kaplan-Meier lifetime table. The incidence of mild pancreatitis was similar in both groups, occurring in 6 patients with covered stents (6/98, 6.1%) and 2 patients with uncovered stents (2/108, 1.9%) (P = .154). Excluding those patients who had previously undergone cholecystectomy, acute cholecystitis occurred in 5 of 88 patients with covered Wallstents (6.1%) and 1 of 100 patients with uncovered stents (1%) (P = .104). Stent migration occurred in 6 patients with covered stents (6.1%) and 0 patients with uncovered stents (P = .011). CONCLUSION: Covered Wallstents might not prolong stent patency compared with uncovered Wallstents when used in the management of malignant extrahepatic biliary obstruction.     

Clinical features of patients with choledocholithiasis showing high levels of aminotransferases]

BACKGROUND/AIMS: We aimed to determine the clinical features of patients with common bile duct (CBD) stones with high serum levels of AST or ALT. METHODS: A retrospective review of 93 patients with CBD stones was done. Clinical characteristics, diameters of CBD, and prior diagnosis before endoscopic retrograde cholangiopancreatography (ERCP) were assessed between two groups (group 1 with serum AST or ALT levels > or =400 IU/L and group 2 with AST and ALT < or =100 IU/L). RESULTS: Nineteen patients in group 1 and 17 patients in group 2 were enrolled. The most common presenting symptom was abdominal pain in both groups. Patients in group 1 was about 14 years younger than group 2 (p=0.003). The duration of symptoms in group 1 and group 2 were 4.1 and 36.8 days, respectively (p=0.005). The diameter of CBD was smaller in group 1 (11.4 mm) than in group 2 (16.3 mm) (p=0.001). Most patients were diagnosed as CBD stones by abdominal ultrasound or computed tomography before ERCP, except two patients in group 1 who were diagnosed as hepatitis initially. All of the patients were recovered by stone removal through ERCP and antibiotics treatment. There were inverse correlations between the diameter of CBD and AST or ALT levels (r=-0.517, p=0.002 and r=-0.504, p=0.002, respectively). CONCLUSIONS: CBD stones with high levels of AST or ALT are frequently observed in younger patients with shorter duration of symptoms and a smaller diameter of CBD. ERCP seems to be a valuable method in the diagnosis and treatment of these patients.     

Hydrophobically modified glycol chitosan nanoparticles as carriers for paclitaxel.

Self-assembled nanoparticles based on hydrophobically modified glycol chitosan (HGC) were prepared as a carrier for paclitaxel. HGC conjugates were prepared by chemically linking 5beta-cholanic acid to glycol chitosan chains using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. In phosphate-buffered saline (PBS; pH 7.4), the synthesized HGC conjugates formed nano-sized particles with a diameter of 200 nm and exhibited high thermodynamic stability as reflected by their low critical aggregation concentration (0.03 mg/ml). Paclitaxel was efficiently loaded into HGC nanoparticles up to 10 wt.% using a dialysis method. The paclitaxel-loaded HGC (PTX-HGC) nanoparticles were 400 nm in diameter and were stable in PBS for 10 days. These PTX-HGC nanoparticles also showed sustained release of the incorporated of paclitaxel (80% of the loaded dose was released in 8 days at 37 degrees C in PBS). Owing to sustained release, the PTX-HGC nanoparticles were less cytotoxic to B16F10 melanoma cells than free paclitaxel formulated in Cremophor EL. Injection of PTX-HGC nanoparticles into the tail vein of tumor-bearing mice prevented increases in tumor volume for 8 days. Finally, PTX was less toxic to the tumor-bearing mice when formulated in HGC nanoparticles than when formulated with Cremophor EL.     

Acupoint Stimulation With Diluted Bee Venom (Apipuncture) Potentiates the Analgesic Effect of Intrathecal Clonidine in the Rodent Formalin Test and in a Neuropathic Pain Model

Although intrathecal (i.t.) administration of the α₂-adrenoceptor agonist clonidine has a pronounced analgesic effect, the clinical use of clonidine is limited by its side effects. Previously, our laboratory has demonstrated that the subcutaneous injection of diluted bee venom (DBV) into an acupoint (termed apipuncture) produces significant analgesic effect in various pain animal models. The present study was designed to examine whether DBV injection into the Zusanli acupoint (ST-36) could enhance lower-dose clonidine-induced analgesic effects without the development of hypotension, bradycardia, or sedation. In the mouse formalin test, DBV injection produced a dramatic leftward shift in the dose-response curve for clonidine-induced analgesia. In a rat neuropathic pain model i.t. clonidine dose dependently suppressed chronic constriction injury (CCI)-induced mechanical allodynia and thermal hyperalgesia, and this clonidine-induced analgesic effect was significantly potentiated by apipuncture pretreatment. DBV apipuncture alone or in combination with a low dose of i.t. clonidine produced an analgesic effect similar to that of the high dose of clonidine, but without significant side effects. The analgesic effect produced by the combination of i.t. clonidine and apipuncture was completely blocked by pretreatment with an α₂-adrenoceptor antagonist. These data show that DBV-apipuncture significantly enhances clonidine-induced analgesia and suggest that a combination of low dose clonidine with acupuncture therapy represents a novel strategy for pain management that could eliminates clonidine's side effects.PerspectiveThis study demonstrated that intrathecal clonidine-induced analgesia is significantly enhanced when it is combined with chemical acupuncture treatment. The administration of low-dose clonidine in combination with acupuncture produced a potent analgesic effect without significant side effects and thus represents a potential novel strategy for the management of chronic pain.     

Topoisomerase Mutations in Fluoroquinolone-Resistant and Methicillin-Susceptible and -Resistant Clinical Isolates of Staphylococcus aureus

The incidence of the various mutations in the genes encoding topoisomerase IV and DNA gyrase in fluoroquinolone-resistant clinical isolates of Staphylococcus aureus is not known. Using restriction fragment length polymorphism analysis and DNA sequencing, we found that in fluoroquinolone- and methicillin-resistant strains, mutations in grlA and gyrA are quite likely to be present together. For fluoroquinolone-resistant but methicillin-susceptible strains, mutations in grlA alone are more common.     

Usefulness of Warm Water and Oil Assistance in Colonoscopy by Trainees

Background and Study Aims

Success rate of cecal intubation, endoscopist’s difficulty, and procedure-related patient pain are still problems for beginners performing colonoscopy. New methods to aid colonoscopic insertion such as warm water instillation and oil lubrication have been proposed. The aim of this study is to evaluate the feasibility of using warm water or oil in colonoscopy.

Methods

Colonoscopy was performed in 117 unsedated patients by three endoscopists-in-training. Patients were randomly allocated to three groups, using a conventional method with administration of antispasmodics, warm water instillation, and oil lubrication, respectively. Success rate of total intubation within time limit (15 min), cecal intubation time, degree of endoscopist’s difficulty, and level of patient discomfort were compared among the three groups.

Results

Cecal intubation time was shorter in the warm water group than in the conventional and oil groups. Degree of procedural difficulty was lower in the warm water group, and patient pain score was higher in the oil lubrication group, compared with the other groups. However, there was no significant difference in success rate of intubation within time limit among the three groups.

Conclusions

The warm water method is a simple, safe, and feasible method for beginners. Oil lubrication may not be a useful method compared with conventional and warm water method.     

The novel role of mast cells in the microenvironment of acute myocardial infarction

Mast cells are multifunctional cells containing various mediators, such as cytokines, tryptase, and histamine, and they have been identified in infarct myocardium. Here, we elucidated the roles of mast cells in a myocardial infarction (MI) rat model. We studied the physiological and functional roles of mast cell granules (MCGs), isolated from rat peritoneal fluid, on endothelial cells, neonatal cardiomyocytes, and infarct heart (1-hour occlusion of left coronary artery followed by reperfusion). The number of mast cells had two peak time points of appearance in the infarct region at 1 day and 21 days after MI induction in rats (p < 0.05 in each compared with sham-operated heart). Simultaneous injection of an optimal dose of MCGs modulated the microenvironment and resulted in the increased infiltration of macrophages and decreased apoptosis of cardiomyocytes without change in the mast cell number in infarct myocardium. Moreover, MCG injection attenuated the progression of MI through angiogenesis and preserved left ventricular function after MI. MCG-treated cardiomyocytes were more resistant to hypoxic injury through phosphorylation of Akt, and MCG-treated endothelial cells showed enhanced migration and tube formation. We have shown that MCGs have novel cardioprotective roles in MI via the prolonged survival of cardiomyocytes and the induction of angiogenesis.     

Effect of Bowel Preparation with Polyethylene Glycol on Quality of Capsule Endoscopy

Background and Aims  

Capsule endoscopy (CE) has the problem that lumen visualization is impaired by bubbles, bile, and debris. The benefits of bowel preparation are still controversial and the best method remains to be determined. The objective of this study was to evaluate the effect of the method of bowel preparation on the quality of visualization and on transit time.     

Bile-Duct Stone Removal under Direct Transnasal Cholangioscopy Using an Ultraslim Upper Endoscope

The transnasal endoscopic examination using an ultraslim upper endoscope may be more comfortable and less stressful than the peroral approach. Transnasal endoscopic retrograde cholangiopancreatography (ERCP), endoscopic nasobiliary drainage, and direct peroral cholangioscopy using an ultraslim upper endoscope have recently been reported. An 82-year-old woman with a previous history of endoscopic sphincterotomy and stone removal was admitted with acute cholangitis. Instead of conventional ERCP, we performed direct transnasal cholangioscopy (TNC) using an ultraslim upper endoscope for biliary decompression and stone removal because of her unstable vital signs. Direct TNC using an ultraslim upper endoscope may be useful in selected patients with biliary disease.