Apoptosis and regulation of Bax and Bcl-X proteins during human neonatal vascular remodeling

To verify that apoptosis is one of the possible mechanisms of neonatal vascular remodeling during the transition from fetal to neonatal circulation, we assayed for apoptosis and evaluated the expression of apoptosis-regulatory proteins in umbilical vessel versus ascending aorta, ductus arteriosus (DA) versus adjacent pulmonary artery and aorta, or aorta versus its branching arteries. Twenty-two umbilical cords (UCs), 6 DAs with adjacent aortas and pulmonary arteries, and 4 aortic arches with their branching great arteries were obtained from neonates. Smooth muscle cell (SMC) apoptosis in umbilical vessels was identified in all UCs. The expressions of Bax and Bcl-X were stronger in umbilical artery than in the neonatal aorta, but Bcl-2 was weak in both arteries in immunohistochemistry. In the immunoblot analysis of UCs, the expression of the proapoptotic short isoform of Bcl-X was stronger than in other tissue, and caspase-3 was selectively activated, whereas it was not in the other components of the cardiovascular system. In contrast, the expression patterns of the FasAg and Fas ligand were similar in umbilical artery and aorta. Regulation of Bcl-2 family proteins was also observed in other vascular sites at which SMCs undergo apoptosis on hemodynamic changes during birth, such as the DA and the branching points of the great arteries from the aortic arch. Apoptosis is involved in the regression of human umbilical vessels and the DA and in the remodeling of the branching great arteries during the neonatal period, when Bcl-2 family proteins are likely to play a key role.     

Cholangiocarcinoma after flow diversion surgery for congenital biliary dilatation: A case report and review of literature

BACKGROUND Pancreaticobiliary maljunction(PBM) can be classified into two categories, PBM with congenital biliary dilatation(CBD) or PBM without biliary dilatation, and the management of PBM is often controversial. The treatment for PBM with CBD is prophylactic flow diversion surgery, and some authors have reported that the incidence of cancer after extrahepatic bile duct excision is less than 1%. A very rare case of intrahepatic cholangiocarcinoma 6 years after flow diversion surgery for PBM with CBD is reported.CASE SUMMARY A 30-year-old man was diagnosed as having PBM with CBD, Todani classification type IVA, because of abnormal liver enzyme profiles. He underwent flow diversion surgery and cholecystectomy, and the specimen showed adenocarcinoma foci, p T1, p Stage IA. Five and a half years passed without any recurrence of bile duct cancer. However, 6 years after his operation, computed tomography showed a gradually growing nodule in the bile duct.Fluorodeoxyglucose positron emission tomography showed high uptake, and magnetic resonance imaging showed restricted diffusion signals. On double balloon enteroscopy, the nodule at the posterior bile duct-jejunum anastomosis was directly visualized, and its biopsy specimen showed adenocarcinoma. The patient underwent right lobectomy and biliary reconstruction. The pathological diagnosis was intraductal papillary neoplasm with high-grade intraepithelial neoplasia, p Tis, p N0, p Stage 0. The patient's postoperative course was uneventful, and he has had no recurrence up to the present time.CONCLUSION This case suggests the necessity of careful observation after flow diversion surgery, especially when PBM with CBD is detected in adulthood.     

Cystic fibrosis transmembrane conductance regulators (CFTR) in biliary epithelium of patients with hepatolithiasis

Cystic fibrosis transmembrane conductance regulator (CFTR) has been considered to be involved in the regulatory pathway of biliary mucin secretion. We investigated expression of CFTR protein and mRNA in 24 livers with hepatolithiasis, in 6 with cholangiocarcinoma, and in 12 histologically normal livers. According to the histologic features of chronic proliferative cholangitis, hepatolithiasis was subdivided into inflammatory cell infiltration predominant (N = 14) and fibrosis predominant (N = 10). The mean signal density of CFTR in overall hepatolithiasis and in histologically normal livers was 1.23 ± 0.15 and 1.01 ± 0.13, respectively (P > 0.05). The CFTR protein (1.60 ± 0.18) and mRNA (1.09 ± 0.15) in inflammatory cell infiltration predominant patients were significantly higher (CFTR protein, 1.01 ± 0.13; mRNA, 0.75 ± 0.11) than in control subjects (P < 0.05), whereas those in fibrosis-predominant patients (CFTR protein, 0.72 ± 0.15; mRNA, 0.55 ± 0.13) were less than in control subjects (P < 0.05). CFTR protein (1.27 ± 0.17) in patients with cholangiocarcinoma was not different from that of control subjects (1.01 ± 0.13). CFTR expression in hepatolithiasis patients was rather heterogeneous but was closely related to the histology of bile ducts.     

Systemic delivery of TNF-related apoptosis-inducing ligand (TRAIL) elevates levels of tissue inhibitor of metalloproteinase-1 (TIMP-1) and prevents type 1 diabetes in nonobese diabetic mice

Recent studies have demonstrated that TNF-related apoptosis-inducing ligand (TRAIL) is a modulator of the immune response. The relation between TRAIL and type 1 diabetes (T1D) as an autoimmune inflammatory disease in vivo is relatively unknown. To explore the potential role of TRAIL in the development of T1D, we examined its in vivo effects in nonobese diabetic (NOD) mice. NOD mice at 7 wk of age were iv injected with an adenovirus carrying either human TRAIL (Ad.hTRAIL) or β-galactosidase genes. Blood glucose was monitored weekly, and the expression of hTRAIL was evaluated in plasma and liver of mice. To investigate whether hTRAIL elicits its effect through the induction of tissue inhibitor of metalloproteinase-1 (TIMP-1), we examined the concentration of plasma TIMP-1 by ELISA and the inhibition of matrix metalloproteinase (MMP) by gelatin zymography. Here, we show that Ad.hTRAIL-transduced mice had significantly reduced blood glucose levels and markedly increased production of TIMP-1 compared with control β-galactosidase animals. Pancreatic tissue isolated from Ad.hTRAIL-treated NOD mice showed reduced MMP activities associated with significantly improved insulitis. In addition, TIMP-1 in vitro suppressed cytokine-induced apoptosis in insulin-producing INS-1 cells. These results indicate that T1D can be prevented by TRAIL overexpression through enhancement of TIMP-1 function. Elevated TIMP-1 production inhibits the activity of MMPs, which may contribute to suppress the transmigration of diabetogenic T cells into the pancreatic islets and protects pancreatic β-cells from cytokine-induced apoptosis. Therefore, TRAIL and TIMP-1 induction may be potential targets to prevent development of T1D.     

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.     

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.     

Structural and functional analysis of the interaction between the nucleoporin Nup98 and the mRNA export factor Rae1

The export of mRNAs is a multistep process, involving the packaging of mRNAs into messenger ribonucleoprotein particles (mRNPs), their transport through nuclear pore complexes, and mRNP remodeling events prior to translation. Ribonucleic acid export 1 (Rae1) and Nup98 are evolutionarily conserved mRNA export factors that are targeted by the vesicular stomatitis virus matrix protein to inhibit host cell nuclear export. Here, we present the crystal structure of human Rae1 in complex with the Gle2-binding sequence (GLEBS) of Nup98 at 1.65 Å resolution. Rae1 forms a seven-bladed β-propeller with several extensive surface loops. The Nup98 GLEBS motif forms an ≈50-Å-long hairpin that binds with its C-terminal arm to an essentially invariant hydrophobic surface that extends over the entire top face of the Rae1 β-propeller. The C-terminal arm of the GLEBS hairpin is necessary and sufficient for Rae1 binding, and we identify a tandem glutamate element in this arm as critical for complex formation. The Rae1•Nup98^GLEBS surface features an additional conserved patch with a positive electrostatic potential, and we demonstrate that the complex possesses single-stranded RNA-binding capability. Together, these data suggest that the Rae1•Nup98 complex directly binds to the mRNP at several stages of the mRNA export pathway.     

Willingness to Undergo Split-Dose Bowel Preparation for Colonoscopy and Compliance with Split-Dose Instructions

Background  

Split-dose bowel preparations for colonoscopy have superior effectiveness compared with giving all the preparation the evening before colonoscopy. Some physicians believe that split-dose preparations would be unpopular with patients scheduled for early morning colonoscopies.     

The gene-reduction effect of chromosomal losses detected in gastric cancers

Background  

The level of loss of heterozygosity (LOH) that reduces a gene dose and exerts a cell-adverse effect is known to be a parameter for the genetic staging of gastric cancers. This study investigated if the cell-adverse effect induced with the gene reduction was a rate-limiting factor for the LOH events in two distinct histologic types of gastric cancers, the diffuse- and intestinal-types.     

Two cases of polymorphic ventricular tachycardia induced by the administration of verapamil against paroxysmal supraventricular tachycardia

Verapamil is widely used for the termination of paroxysmal supraventricular tachycardia (PSVT) with little proarrhythmic effect. We describe two cases of PSVT that changed to non-sustained polymorphic ventricular tachycardia after administration of verapamil. Electrophysiological study revealed atrioventricular nodal reentrant tachycardia in the first case, and atrioventricular reentrant tachycardia due to a concealed left lateral accessory pathway in the second case. Catecholamine-induced automaticity was one of the possible mechanisms of VT in the first case, but the mechanism is unknown in the second case.