bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endoscopic decompression of benign large bowel obstruction using a transanal drainage tube
Authors: Horiuchi A. , Nakayama Y. , Kajiyama M. , Kamijima T. , Kato N. , Ichise Y. , Tanaka N. 
Published: March 2011

AbstractAim  Endoscopic decompression of malignant colorectal obstruction is often dealt with using expandable metallic stents. Endoscopic decompression of benign large bowel obstruction is more difficult. We report the technique and outcome of transanal endoscopic decompression for benign large bowel obstruction.Method  From January 2001 to June 2010, endoscopic decompression using a transanal drainage tube placement was attempted in consecutive patients with benign large bowel obstruction. The clinical features, technical success, complications, treatment after the tube placement and clinical success were retrospectively evaluated.Results  There were 13 patients (seven males, age 47–87, mean 69 years). The sites of obstruction were transverse colon [5 (38%)], sigmoid colon [3 (23%)], ileocecal valve [2 (15%)], splenic flexure [1 (8%)], descending colon [1 (8%)] and rectum [1 (8%)]. The most common cause of obstruction was anastomotic stricture [9 (69%)]. In 12 (92%) patients transanal decompression was technically successful with one perforation. An overtube, the reinsertion of colonoscope along the decompression tube, or the use of a small‐diameter endoscope was required for the tube placement in seven (54%). In seven (54%) patients tube placement alone resulted in relief of bowel obstruction without operation.Conclusion  Endoscopic decompression using a transanal drainage tube is effective for the management of benign large bowel obstruction.
Efficient Depth‐of‐Field Rendering with Adaptive Sampling and Multiscale Reconstruction
Authors: Chen Jiating , Wang Bin , Wang Yuxiang , Overbeck Ryan S. , Yong Jun‐Hai , Wang Wenping 
Published: March 2011

AbstractDepth‐of‐field is one of the most crucial rendering effects for synthesizing photorealistic images. Unfortunately, this effect is also extremely costly. It can take hundreds to thousands of samples to achieve noise‐free results using Monte Carlo integration. This paper introduces an efficient adaptive depth‐of‐field rendering algorithm that achieves noise‐free results using significantly fewer samples. Our algorithm consists of two main phases: adaptive sampling and image reconstruction. In the adaptive sampling phase, the adaptive sample density is determined by a ‘blur‐size’ map and ‘pixel‐variance’ map computed in the initialization. In the image reconstruction phase, based on the blur‐size map, we use a novel multiscale reconstruction filter to dramatically reduce the noise in the defocused areas where the sampled radiance has high variance. Because of the efficiency of this new filter, only a few samples are required. With the combination of the adaptive sampler and the multiscale filter, our algorithm renders near‐reference quality depth‐of‐field images with significantly fewer samples than previous techniques.
The PI3K‐Akt pathway inhibits senescence and promotes self‐renewal of human skin‐derived precursors in vitro
Authors: Liu Shuang , Liu Shu , Wang Xinyue , Zhou Jiaxi , Cao Yujing , Wang Fei , Duan Enkui 
Published: March 2011

SummarySkin‐derived precursors (SKPs) are embryonic neural crest‐ or somite‐derived multipotent progenitor cells with properties of dermal stem cells. Although a large number of studies deal with their differentiation ability and potential applications in tissue damage repair, only a few studies have concentrated on the regulation of SKP self‐renewal. Here, we found that after separation from their physiological microenvironment, human foreskin‐derived SKPs (hSKPs) quickly senesced and lost their self‐renewal ability. We observed a sharp decrease in Akt activity during this process, suggesting a possible role of the PI3K‐Akt pathway in hSKP maintenance in vitro. Blocking this pathway with several inhibitors inhibited hSKP proliferation and sphere formation and increased hSKP senescence. In contrast, activating this pathway with PDGF‐AA and a PTEN inhibitor, bpV(pic), promoted proliferation, improved sphere formation, and alleviated senescence of hSKPs, without altering their differentiation potential. Data also implied that this effect was associated with altered actions of FoxO3 and GSK‐3β. Our results suggest an important role of the PI3K‐Akt pathway in the senescence and self‐renewal of hSKPs. These findings also provide a better understanding of the cellular mechanisms underlying hSKP self‐renewal and stem cell senescence to allow more efficient expansion of hSKPs for regenerative medical applications.
Store‐operated calcium entry remains fully functional in aged mouse skeletal muscle despite a decline in STIM1 protein expression
Authors: Edwards Joshua N. , Blackmore Daniel G. , Gilbert Daniel F. , Murphy Robyn M. , Launikonis Bradley S. 
Published: March 2011

SummaryStore‐operated Ca2+ entry (SOCE) is a robust mechanism in skeletal muscle, supported by abundant STIM1 and Orai1 in the junctional membranes. The precise role of SOCE in skeletal muscle Ca2+ homeostasis and excitation–contraction coupling remains to be defined. Regardless, it remains important to determine whether the function and capacity of SOCE changes in aged skeletal muscle. We identified an approximate 40% decline in the expression of the integral SOCE protein, stromal interacting molecule 1 (STIM1), but no such decline in its coupling partner, Orai1, in muscle fibers from aged mice. To determine whether this changed aspects of SOCE functionality in skeletal muscle in aged mice, Ca2+ in the cytoplasm and t‐system were continuously and simultaneously imaged on a confocal microscope during sarcoplasmic reticulum Ca2+ release and compared to experiments under identical conditions using muscle fibers from young mice. Normal activation, deactivation, Ca2+ influx, and spatiotemporal characteristics of SOCE were found to persist in skeletal muscle from aged mice. Thus, SOCE remains a robust mechanism in aged skeletal muscle despite the decline in STIM1 protein expression, suggesting STIM1 is in excess in young skeletal muscle.
Mechanism‐based inhibition of cytochrome P450 (CYP)2A6 by chalepensin in recombinant systems, in human liver microsomes and in mice in vivo
Authors: Ueng Yune‐Fang , Chen Chien‐Chih , Chung Yu‐Ting , Liu Tsung‐Yun , Chang Yu‐Ping , Lo Wei‐Sheng , Murayama Norie , Yamazaki Hiroshi , Souček Pavel , Chau Gar‐Yang , Chi Chin‐Wen , Chen Ruei‐Ming , Li Ding‐Tzai 
Published: March 2011

BACKGROUND AND PURPOSE Chalepensin is a pharmacologically active furanocoumarin compound found in rue, a medicinal herb. Here we have investigated the inhibitory effects of chalepensin on cytochrome P450 (CYP) 2A6 in vitro and in vivo.EXPERIMENTAL APPROACH Mechanism‐based inhibition was studied in vitro using human liver microsomes and bacterial membranes expressing genetic variants of human CYP2A6. Effects in vivo were studied in C57BL/6J mice. CYP2A6 activity was assayed as coumarin 7‐hydroxylation (CH) using HPLC and fluorescence measurements. Metabolism of chalepensin was assessed with liquid chromatography/mass spectrometry (LC/MS).KEY RESULTS CYP2A6.1, without pre‐incubation with NADPH, was competitively inhibited by chalepensin. After pre‐incubation with NADPH, inhibition by chalepensin was increased (IC50 value decreased by 98%). This time‐dependent inactivation (kinact 0.044 min−1; KI 2.64 µM) caused the loss of spectrally detectable P450 content and was diminished by known inhibitors of CYP2A6, pilocarpine or tranylcypromine, and by glutathione conjugation. LC/MS analysis of chalepensin metabolites suggested an unstable epoxide intermediate was formed, identified as the corresponding dihydrodiol, which was then conjugated with glutathione. Compared with the wild‐type CYP2A6.1, the isoforms CYP2A6.7 and CYP2A6.10 were less inhibited. In mouse liver microsomes, pre‐incubation enhanced inhibition of CH activity. Oral administration of chalepensin to mice reduced hepatic CH activity ex vivo.CONCLUSIONS AND IMPLICATIONS Chalepensin was a substrate and a mechanism‐based inhibitor of human CYP2A6. Formation of an epoxide could be a key step in this inactivation. ‘Poor metabolizers’ carrying CYP2A6*7 or *10 may be less susceptible to inhibition by chalepensin. Given in vivo, chalepensin decreased CYP2A activity in mice.
Endocannabinoids and traumatic brain injury
Authors: Shohami Esther , Cohen‐Yeshurun Ayelet , Magid Lital , Algali Merav , Mechoulam Raphael 
Published: March 2011

Traumatic brain injury (TBI) represents the leading cause of death in young individuals. It triggers the accumulation of harmful mediators, leading to secondary damage, yet protective mechanisms are also set in motion. The endocannabinoid (eCB) system consists of ligands, such as anandamide and 2‐arachidonoyl‐glycerol (2‐AG), receptors (e.g. CB1, CB2), transporters and enzymes, which are responsible for the ‘on‐demand’ synthesis and degradation of these lipid mediators. There is a large body of evidence showing that eCB are markedly increased in response to pathogenic events. This fact, as well as numerous studies on experimental models of brain toxicity, neuroinflammation and trauma supports the notion that the eCB are part of the brain's compensatory or repair mechanisms. These are mediated via CB receptors signalling pathways that are linked to neuronal survival and repair. The levels of 2‐AG, the most highly abundant eCB, are significantly elevated after TBI and when administered to TBI mice, 2‐AG decreases brain oedema, inflammation and infarct volume and improves clinical recovery. The role of CB1 in mediating these effects was demonstrated using selective antagonists or CB1 knockout mice. CB2 were shown in other models of brain insults to reduce white blood cell rolling and adhesion, to reduce infarct size and to improve motor function. This review is focused on the role the eCB system plays as a self‐neuroprotective mechanism and its potential as a basis for the development of novel therapeutic modality for the treatment of CNS pathologies with special emphasis on TBI.LINKED ARTICLES This article is part of a themed issue on Cannabinoids in Biology and Medicine. To view the other articles in this issue visit http://dx.doi.org/10.1111/bph.2011.163.issue‐7
Fangchinoline induces autophagic cell death via p53/sestrin2/AMPK signalling in human hepatocellular carcinoma cells
Authors: Wang Ning , Pan Weidong , Zhu Meifen , Zhang Maosheng , Hao Xiaojian , Liang Guangyi , Feng Yibin 
Published: March 2011

BACKGROUND AND PURPOSE Fangchinoline is a novel anti‐tumour agent with little known of its cellular and molecular mechanisms of action. Here we have investigated the mode of cell death induced by fangchinoline and its underlying mechanism in two human hepatocellular carcinoma cell lines, HepG2 and PLC/PRF/5.EXPERIMENTAL APPROACH Apoptosis and autophagy were monitored in fangchinoline‐treated HepG2 and PLC/PRF/5 cells by histological methods. The signal transduction pathways involved in activation of autophagy were examined, using immunoblotting, real‐time PCR and siRNA techniques.KEY RESULTS Fangchinoline did not induce apoptosis in HepG2 and PLC/PRF/5 cells but triggered, dose‐dependently, autophagy, an alternative mode of cell death which may contribute to fangchinoline's anti‐tumour action. Nuclear translocation of p53 was involved in induction of autophagy by fangchinoline, followed by selective transactivation of the autophagy‐related gene sestrin2 and initiation of the autophagic process. Signalling by the AMP‐activated protein kinase was also involved as a downstream target of sestrin2 and induced mTOR‐independent autophagic cell death in both cell lines. siRNA for Atg 5 or pharmacological block of p53 abolished fangchinoline‐induced autophagy and inhibition of autophagy switched cell death to apoptosis in these cells, suggesting that cell death is irreversible once autophagy is induced by fangchinoline.CONCLUSIONS AND IMPLICATIONS Fangchinoline is a highly specific agent inducing autophagic cell death in hepatocellular carcinoma cells with a novel mechanism, which elucidates the potential of fangchinoline to potentiate programmed cell death in cancer cells.
Surgical Treatment of a Meningoencephalocele in a Cat
Authors: Dewey Curtis W. , Brewer David M. , Cautela Michaela A. , Talarico Lauren R. , Silver Gena M. 
Published: March 2011

Objective: To report the clinical signs, imaging findings and surgical treatment of a meningoencephalocele in a cat.Study Design: Case report.Animal: Domestic shorthaired cat, 4 months old.Methods: A parietal meningoencephalocele was identified and characterized by magnetic resonance and computed tomography (CT) imaging. The abnormal tissue was excised and submitted for histopathology, and the meningeal and skull defects were reconstructed.Results: The cat made a full recovery and the episodes of aggression, restlessness and apparent discomfort that occurred before surgery ceased after surgical treatment. The cat was clinically normal 1 year postoperatively.Conclusion: Surgical management of meningoencephalocele in cats may be a viable treatment option.
A Wound Retraction Device for Laparoscopic‐Assisted Intestinal Surgery in Dogs and Cats
Authors: Gower Sara B. , Mayhew Philipp D. 
Published: March 2011

Objectives: To report experience with laparoscopic‐assisted intestinal resection and anastomosis for treatment of discrete intestinal masses using a novel wound retraction device.Study Design: Case series.Animals: Dogs (n=2) and cats (6).Methods: Dogs and cats with discrete intestinal masses identified by ultrasonography without evidence of intestinal perforation or peritonitis, were included. A 2 portal technique was used; 1 portal was enlarged for insertion of the wound retraction device through which the intestine was examined as thoroughly as possible. The diseased portion of the intestine was exteriorized through the wound retractor and resection and anastomosis of the intestinal mass performed.Results: Of the 8 animals, laparoscopic‐assisted intestinal resection and anastomosis through the wound retractor was performed in 2 dogs and 3 cats. In 3 cats, based on either location or extent of the lesion, 2 were converted to laparoscopic‐assisted intestinal biopsies and 1 to an open colocolostomy. No other intra‐ or perioperative complications were encountered and all animals survived to discharge.Conclusions: Laparoscopic‐assisted intestinal resection and anastomosis can be performed in select canine and feline patients with modestly sized, discrete intestinal masses.
Outcome after Repair of a Sarcoma‐Related Pathologic Fracture in Dogs: A Veterinary Society of Surgical Oncology Retrospective Study
Authors: Boston Sarah E. , Bacon Nicholas J. , Culp William T.N. , Bhandal Jitender , Bruce Charles , Cavanaugh Ryan P. , Hamilton Michael H. , Lincoln James D. , Liptak Julius M. , Scharvogel Stefan 
Published: March 2011

Objective: To report outcome in dogs after internal fixation of a sarcoma‐related pathologic fracture of the appendicular skeleton.Study Design: Multi‐institutional case series.Animals: Dogs (n=16).Methods: Medical records of participating VSSO members were reviewed for dogs with pathologic fracture associated with a confirmed bone sarcoma of the appendicular skeleton repaired by external or internal fixation. Dogs were included if they had a histological diagnosis of osteosarcoma or sarcoma and excluded if they had radiation before fracture. Data collected were analyzed for signalment, fracture location, staging performed, method of fracture fixation, histopathology, adjunctive treatment and outcome.Results: Signalment and fracture location of 16 dogs that met the inclusion criteria was similar to dogs with appendicular OSA without fracture. One of 14 dogs had pulmonary metastasis and 3 of 5 dogs had bone metastasis. Bone plate or interlocking nail were used for repair in 12 dogs. Limb use immediately after surgery in 13 dogs was good (4), weight‐bearing but lame (7) and non‐weight bearing (2). Adjunctive therapy was administered in 5 dogs (chemotherapy, 3; radiation, 4; pamidronate, 3). Survival time ranged from 18 to 897 days; median survival was 166 days.Conclusions: Repair of pathologic fracture can result in palliation and prolonged survival.
Anatomic Study of the Canine Stifle Using Low‐Field Magnetic Resonance Imaging (MRI) and MRI Arthrography
Authors: Pujol Esteban , Van Bree Henri , Cauzinille Laurent , Poncet Cyrill , Gielen Ingrid , Bouvy Bernard 
Published: March 2011

Objective: To investigate the use of low‐field magnetic resonance imaging (MRI) and MR arthrography in normal canine stifles and to compare MRI images to gross dissection.Study Design: Descriptive study.Sample Population: Adult canine pelvic limbs (n=17).Methods: Stifle joints from 12 dogs were examined by orthopedic and radiographic examination, synovial fluid analysis, and MRI performed using a 0.2 T system. Limbs 1 to 7 were used to develop the MR and MR arthrography imaging protocol. Limbs 8–17 were studied with the developed MR and MR arthrography protocol and by gross dissection. Three sequences were obtained: T1‐weighted spin echo (SE) in sagittal, dorsal, and transverse plane; T2‐weighted SE in sagittal plane and T1‐gradient echo in sagittal plane.Results: Specific bony and soft tissue structures were easily identifiable with the exception of articular cartilage. The cranial and caudal cruciate ligaments were identified. Medial and lateral menisci were seen as wedge‐shaped hypointense areas. MR arthrography permitted further delineation of specific structures. MR images corresponded with gross dissection morphology.Conclusions: With the exception of poor delineation of articular cartilage, a low‐field MRI and MR arthrography protocol provides images of adequate quality to assess the normal canine stifle joint.
Public Information and Coordination: Evidence from a Credit Registry Expansion
Authors: HERTZBERG ANDREW , LIBERTI JOSÉ MARÍA , PARAVISINI DANIEL 
Published: March 2011

ABSTRACTThis paper provides evidence that lenders to a firm close to distress have incentives to coordinate: lower financing by one lender reduces firm creditworthiness and causes other lenders to reduce financing. To isolate the coordination channel from lenders' joint reaction to new information, we exploit a natural experiment that forced lenders to share negative private assessments about their borrowers. We show that lenders, while learning nothing new about the firm, reduce credit in anticipation of other lenders' reaction to the negative news about the firm. The results show that public information exacerbates lender coordination and increases the incidence of firm financial distress.
Private Equity and Long‐Run Investment: The Case of Innovation
Authors: LERNER JOSH , SORENSEN MORTEN , STRÖMBERG PER 
Published: March 2011

ABSTRACTA long‐standing controversy is whether leveraged buyouts (LBOs) relieve managers from short‐term pressures from public shareholders, or whether LBO funds themselves sacrifice long‐term growth to boost short‐term performance. We examine one form of long‐run activity, namely, investments in innovation as measured by patenting activity. Based on 472 LBO transactions, we find no evidence that LBOs sacrifice long‐term investments. LBO firm patents are more cited (a proxy for economic importance), show no shifts in the fundamental nature of the research, and become more concentrated in important areas of companies' innovative portfolios.
Do Buyouts (Still) Create Value?
Authors: GUO SHOURUN , HOTCHKISS EDITH S. , SONG WEIHONG 
Published: March 2011

ABSTRACTWe examine how leveraged buyouts from the most recent wave of public to private transactions created value. Buyouts completed between 1990 and 2006 are more conservatively priced and less levered than their predecessors from the 1980s. For deals with post‐buyout data available, median market‐ and risk‐adjusted returns to pre‐ (post‐) buyout capital invested are 72.5% (40.9%). In contrast, gains in operating performance are either comparable to or slightly exceed those observed for benchmark firms. Increases in industry valuation multiples and realized tax benefits from increasing leverage, while private, are each economically as important as operating gains in explaining realized returns.
Corporate Governance, Product Market Competition, and Equity Prices
Authors: GIROUD XAVIER , MUELLER HOLGER M. 
Published: March 2011

ABSTRACTThis paper examines whether firms in noncompetitive industries benefit more from good governance than do firms in competitive industries. We find that weak governance firms have lower equity returns, worse operating performance, and lower firm value, but only in noncompetitive industries. When exploring the causes of the inefficiency, we find that weak governance firms have lower labor productivity and higher input costs, and make more value‐destroying acquisitions, but, again, only in noncompetitive industries. We also find that weak governance firms in noncompetitive industries are more likely to be targeted by activist hedge funds, suggesting that investors take actions to mitigate the inefficiency.
Institutional Trade Persistence and Long‐Term Equity Returns
Authors: DASGUPTA AMIL , PRAT ANDREA , VERARDO MICHELA 
Published: March 2011

ABSTRACTRecent studies show that single‐quarter institutional herding positively predicts short‐term returns. Motivated by the theoretical herding literature, which emphasizes endogenous persistence in decisions over time, we estimate the effect of multiquarter institutional buying and selling on stock returns. Using both regression and portfolio tests, we find that persistent institutional trading negatively predicts long‐term returns: persistently sold stocks outperform persistently bought stocks at long horizons. The negative association between returns and institutional trade persistence is not subsumed by past returns or other stock characteristics, is concentrated among smaller stocks, and is stronger for stocks with higher institutional ownership.
Local Dividend Clienteles
Authors: BECKER BO , IVKOVIĆ ZORAN , WEISBENNER SCOTT 
Published: March 2011

ABSTRACTWe exploit demographic variation to identify the effect of dividend demand on corporate payout policy. Retail investors tend to hold local stocks and older investors prefer dividend‐paying stocks. Together, these tendencies generate geographically varying demand for dividends. Firms headquartered in areas in which seniors constitute a large fraction of the population are more likely to pay dividends, initiate dividends, and have higher dividend yields. We also provide indirect evidence as to why managers may respond to the demand for dividends from local seniors. Overall, these results are consistent with the notion that the investor base affects corporate policy choices.