bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasminogen activator inhibitor-1 (PAI-1) is cardioprotective in mice by maintaining microvascular integrity and cardiac architecture
Authors: Xu Zhi , Castellino Francis J. , Ploplis Victoria A. 
Published: December 2009

Abstract
Although the involvement of plasminogen activator inhibitor-1 (PAI-1) in fibrotic diseases is well documented, its role in cardiac fibrosis remains controversial. The goal of this study was to determine the effect of a PAI-1 deficiency (PAI-1−/−) on the spontaneous development of cardiac fibrosis. PAI-1−/− mice developed pervasive cardiac fibrosis spontaneously with aging, and these mice displayed progressively distorted cardiac architecture and markedly reduced cardiac function. To mechanistically elucidate the role of PAI-1 in cardiac fibrosis, 12-week-old mice were chosen to study the biologic events leading to fibrosis. Although fibrosis was not observed at this early age, PAI-1−/− hearts presented with enhanced inflammation, along with increased microvascular permeability and hemorrhage. A potent fibrogenic cytokine, transforming growth factor-β (TGF-β), was markedly enhanced in PAI-1−/− heart tissue. Furthermore, the expression levels of several relevant proteases associated with tissue remodeling were significantly enhanced in PAI-1−/− hearts. These results suggest that PAI-1 is cardioprotective, and functions in maintaining normal microvasculature integrity. Microvascular leakage in PAI-1−/− hearts may provoke inflammation, and predispose these mice to cardiac fibrosis. Therefore, a PAI-1 deficiency contributes to the development of cardiac fibrosis by increasing vascular permeability, exacerbating local inflammation, and increasing extracellular matrix remodeling, an environment conducive to accelerated fibrosis.
Biochemical evidence for the tyrosine involvement in cationic intermediate stabilization in mouse β-carotene 15, 15'-monooxygenase
Authors: Poliakov Eugenia , Gentleman Susan , Chander Preethi , Cunningham Francis X , Grigorenko Bella L , Nemuhin Alexander V , Redmond T Michael 
Published: December 2009

Abstract

Background
β-carotene 15,15'-monooxygenase (BCMO1) catalyzes the crucial first step in vitamin A biosynthesis in animals. We wished to explore the possibility that a carbocation intermediate is formed during the cleavage reaction of BCMO1, as is seen for many isoprenoid biosynthesis enzymes, and to determine which residues in the substrate binding cleft are necessary for catalytic and substrate binding activity. To test this hypothesis, we replaced substrate cleft aromatic and acidic residues by site-directed mutagenesis. Enzymatic activity was measured in vitro using His-tag purified proteins and in vivo in a β-carotene-accumulating E. coli system.

Results
Our assays show that mutation of either Y235 or Y326 to leucine (no cation-π stabilization) significantly impairs the catalytic activity of the enzyme. Moreover, mutation of Y326 to glutamine (predicted to destabilize a putative carbocation) almost eliminates activity (9.3% of wt activity). However, replacement of these same tyrosines with phenylalanine or tryptophan does not significantly impair activity, indicating that aromaticity at these residues is crucial. Mutations of two other aromatic residues in the binding cleft of BCMO1, F51 and W454, to either another aromatic residue or to leucine do not influence the catalytic activity of the enzyme. Our ab initio model of BCMO1 with β-carotene mounted supports a mechanism involving cation-π stabilization by Y235 and Y326.

Conclusions
Our data are consistent with the formation of a substrate carbocation intermediate and cation-π stabilization of this intermediate by two aromatic residues in the substrate-binding cleft of BCMO1.
Multiple recombinants in two dengue virus, serotype-2 isolates from patients from Oaxaca, Mexico
Authors: Perez-Ramirez Gerardo , Diaz-Badillo Alvaro , Camacho-Nuez Minerva , Cisneros Alejandro , Munoz Maria de Lourdes 
Published: December 2009

Abstract

Background
Dengue (DEN) is a serious cause of mortality and morbidity in the world including Mexico, where the infection is endemic. One of the states with the highest rate of dengue cases is Oaxaca. The cause of DEN is a positive-sense RNA virus, the dengue virus (DENV) that evolves rapidly increasing its variability due to the absence of a repair mechanism that leads to approximately one mutational event per genome replication; which results in enhancement of viral adaptation, including the escape from host immune responses. Additionally, recombination may play a role in driving the evolution of DENV, which may potentially affect virulence and cause host tropism changes. Recombination in DENV has not been described in Mexican strains, neither has been described the relevance in virus evolution in an endemic state such as Oaxaca where the four serotypes of DENV are circulating.

Results
To study whether there are isolates from Oaxaca having recombination, we obtained the sequence of 6 different isolates of DENV-2 Asian/American genotype from the outbreak 2005-6, one clone of the C(91)-prM-E-NS1(2400) structural genes, and 10 clones of the E gene from the isolate MEX_OAX_1656_05. Evidence of recombination was found by using different methods along with two softwares: RDP3 and GARD. The Oaxaca MEX_OAX_1656_05 and MEX_OAX_1038_05 isolates sequenced in this study were recombinant viruses that incorporate the genome sequence from the Cosmopolitan genotype. Furthermore, the clone of the E gene namely MEX_OAX_165607_05 from this study was also recombinant, incorporating genome sequence from the American genotype.

Conclusions
This is the first report of recombination in DENV-2 in Mexico. Given such a recombinant activity new genomic combinations were produced, this could play a significant role in the DENV evolution and must be considered as a potentially important mechanism generating genetic variation in this virus with serious implications for the vaccines and drugs formulation as occurs for other viruses like poliovirus, influenza and HIV.
Phlegmonous colitis: another source of sepsis in cirrhotic patients?
Authors: Holzer Thomas , Gervaz Pascal , Spahr Laurent , McKee Thomas , Bucher Pascal , Morel Philippe 
Published: December 2009

Abstract

Background
The clinical relevance of phlegmonous colitis (PC), a rare autopsy finding in cirrhotic patients, is poorly documented. We postulated that PC might be a source of sepsis in patients with portal hypertensive colopathy (PHC).

Case presentation
We report three cirrhotic patients who were admitted with abdominal sepsis and who illustrate, to various degrees, the clinico-pathological sequence of colonic alterations associated with portal hypertension. Two cirrhotic patients with PHC developed gram-negative bacteraemia and quickly responded to intravenous antibiotics. Another cirrhotic patient underwent emergency colectomy for PC, and subsequently died from multiple organ failure. Histological alterations in the operative specimen included: a) mucosal ulcerations; b) disseminated micro-abscesses in the submucosa; and c) a severe vasculopathy leading to complete obliteration of submucosal blood vessels.

Conclusions
These data suggest that cirrhotic patients with PHC may progress towards PC, which, in turn, may be the cause for life-threatening sepsis.
Sensitive HPV detection in oropharyngeal cancers
Authors: Winder David M , Ball Siolian LR , Vaughan Katie , Hanna Nashat , Woo Yin Ling , Fränzer Jürgen-Theodor , Sterling Jane C , Stanley Margaret A , Sudhoff Holger , Goon Peter KC 
Published: December 2009

Abstract

Background
Human papillomaviruses (HPV) are the aetiological agents of certain benign and malignant tumours of skin and mucosae; the most important of which is cervical cancer. Also, the incidence of ano-genital warts, HPV-anal cancer and oropharyngeal cancers are rising. To help ascertain a useful PCR detection protocol for oropharyngeal cancers, we directly compared three commonly used primer sets in detection of HPV from different clinical samples.

Methods
We compared PGMY09/11, MY09/11 and GP5+/6+ primers sets in PCRs of 34 clinically diagnosed samples of genital warts, cervical brushings (with associated histological diagnosis) and vulval biopsies. All negative samples were subsequently tested using the previously reported PGMY/GP PCR method and amplicons directly sequenced for confirmation and typing. An optimised PCR protocol was then compared to a line blot assay for detection of HPV in 15 oropharyngeal cancer samples.

Results
PGMY09/11 primers detected HPV presence in more cervical brushing (100%) and genital wart (92.9%) samples compared to MY09/11 (90% and 64.3%) and GP5+/6+ (80% and 64.3%) primer sets, respectively. From vulval biopsies, HPV detection rates were: MY09/11 (63.6%), GP5+/6+ (54.5%) and PGMY09/11 (54.5%). PGMY/GP nested PCR demonstrated that HPV was present, and direct sequencing confirmed genotypes. This nested PCR protocol showed detection of HPV in 10/15 (66.7%) of oropharyngeal cancer samples.

Conclusions
PGMY09/11 primers are the preferred primer set among these three for primary PCR screening with different clinical samples. MY09/11 and GP5+/6+ may be used (particularly for cervical samples) but demonstrate lower detection rates. A nested PCR approach (i.e. a PGMY-GP system) may be required to confirm negativity or to detect low levels of HPV, undetectable using current primary PCR methods, as demonstrated using oropharyngeal cancer samples.
Design of the Balance@Work project: systematic development, evaluation and implementation of an occupational health guideline aimed at the prevention of weight gain among employees
Authors: Verweij Lisanne M , Proper Karin I , Weel Andre NH , Hulshof Carel TJ , van Mechelen Willem 
Published: December 2009

Abstract

Background
Occupational health professionals may play an important role in preventive health promotion activities for employees. However, due to a lack of knowledge and evidence- and practice based methods and strategies, interventions are hardly being implemented by occupational physicians to date. The aim of the Balance@Work project is to develop, evaluate, and implement an occupational health guideline aimed at the prevention of weight gain among employees.

Methods
Following the guideline development protocol of the Netherlands Society of Occupational Medicine and the Intervention Mapping protocol, the guideline was developed based on literature, interviews with relevant stakeholders, and consensus among an expert group. The guideline consists of an individual and an environmental component. The individual component includes recommendations for occupational physicians on how to promote physical activity and healthy dietary behavior based on principles of motivational interviewing. The environmental component contains an obesogenic environment assessment tool. The guideline is evaluated in a randomised controlled trial among 20 occupational physicians. Occupational physicians in the intervention group apply the guideline to eligible workers during 6 months. Occupational physicians in the control group provide care as usual. Measurements take place at baseline and 6, 12, and 18 months thereafter. Primary outcome measures include waist circumference, daily physical activity and dietary behavior. Secondary outcome measures include sedentary behavior, determinants of behavior change, body weight and body mass index, cardiovascular disease risk profile, and quality of life. Additionally, productivity, absenteeism, and cost-effectiveness are assessed.

Discussion
Improving workers' daily physical activity and dietary behavior may prevent weight gain and subsequently improve workers' health, increase productivity, and reduce absenteeism. After an effect- and process evaluation the guideline will be adjusted and, after authorisation, published. Together with several implementation aids, the published guideline will be disseminated broadly by the Netherlands Society of Occupational Medicine.

Trial Registration
ISRCTN73545254/NTR1190
Recombinant protein expression by targeting pre-selected chromosomal loci
Authors: Nehlsen Kristina , Schucht Roland , da Gama-Norton Leonor , Krömer Wolfgang , Baer Alexandra , Cayli Aziz , Hauser Hansjörg , Wirth Dagmar 
Published: December 2009

Abstract

Background
Recombinant protein expression in mammalian cells is mostly achieved by stable integration of transgenes into the chromosomal DNA of established cell lines. The chromosomal surroundings have strong influences on the expression of transgenes. The exploitation of defined loci by targeting expression constructs with different regulatory elements is an approach to design high level expression systems. Further, this allows to evaluate the impact of chromosomal surroundings on distinct vector constructs.

Results
We explored antibody expression upon targeting diverse expression constructs into previously tagged loci in CHO-K1 and HEK293 cells that exhibit high reporter gene expression. These loci were selected by random transfer of reporter cassettes and subsequent screening. Both, retroviral infection and plasmid transfection with eGFP or antibody expression cassettes were employed for tagging. The tagged cell clones were screened for expression and single copy integration. Cell clones producing > 20 pg/cell in 24 hours could be identified. Selected integration sites that had been flanked with heterologous recombinase target sites (FRTs) were targeted by Flp recombinase mediated cassette exchange (RMCE). The results give proof of principle for consistent protein expression upon RMCE. Upon targeting antibody expression cassettes 90-100% of all resulting cell clones showed correct integration. Antibody production was found to be highly consistent within the individual cell clones as expected from their isogenic nature. However, the nature and orientation of expression control elements revealed to be critical. The impact of different promoters was examined with the tag-and-targeting approach. For each of the chosen promoters high expression sites were identified. However, each site supported the chosen promoters to a different extent, indicating that the strength of a particular promoter is dominantly defined by its chromosomal context.

Conclusion
RMCE provides a powerful method to specifically design vectors for optimized gene expression with high accuracy. Upon considering the specific requirements of chromosomal sites this method provides a unique tool to exploit such sites for predictable expression of biotechnologically relevant proteins such as antibodies.
Developing 21stcentury accreditation standards for teaching hospitals: the Taiwan experience
Authors: Huang Chung-I , Wung Cathy , Yang Che-Ming 
Published: December 2009

Abstract

Background
The purpose of this study is to establish teaching hospital accreditation standards anew with the hope that Taiwan's teaching hospitals can live up to the expectations of our society and ensure quality teaching.

Methods
The development process lasted two years, 2005-2006, and was separated into three stages. The first stage centered on leadership meetings and consensus building, the second on drafting the new standards with expert focus groups, and the third on a pilot study and subsequent revision.

Results
Our new teaching hospital accreditation standards have six categories and 95 standards as follows: educational resources (20 items), teaching and training plans and outcomes (42 items), research and results (9 items), development of clinical faculty and continuing education (8 items), academic exchanges and community education (8 items), and administration (8 items).

Conclusions
The new standards have proven feasible and posed reasonable challenges in the pilot study. We hope the new standards will strengthen teaching and research, and improve the quality of hospital services at the same time.
An evolved xylose transporter from Zymomonas mobilis enhances sugar transport in Escherichia coli
Authors: Ren Chuan , Chen Tingjian , Zhang Jingqing , Liang Ling , Lin Zhanglin 
Published: December 2009

Abstract

Background
Xylose is a second most abundant sugar component of lignocellulose besides glucose. Efficient fermentation of xylose is important for the economics of biomass-based biorefineries. However, sugar mixtures are sequentially consumed in xylose co-fermentation with glucose due to carbon catabolite repression (CCR) in microorganisms. As xylose transmembrance transport is one of the steps repressed by CCR, it is therefore of interest to develop a transporter that is less sensitive to the glucose inhibition or CCR.

Results
The glucose facilitator protein Glf transporter from Zymomonas mobilis, also an efficient transporter for xylose, was chosen as the target transporter for engineering to eliminate glucose inhibition on xylose uptake. The evolution of Glf transporter was carried out with a mixture of glucose and xylose in E. coli. Error-prone PCR and random deletion were employed respectively in two rounds of evolution. Aided by a high-throughput screening assay using xylose analog p-nitrophenyl-β-D-xylopyranoside (pNPX) in 96-well plates, a best mutant 2-RD5 was obtained that contains several mutations, and a deletion of 134 residues (about 28% of total residues), or three fewer transmembrane sections (TMSs). It showed a 10.8-fold improvement in terms of pNPX transport activity in the presence of glucose. The fermentation performance results showed that this mutant improved xylose consumption by 42% with M9 minimal medium containing 20 g L-1 xylose only, while with the mixture sugar of xylose and glucose, 28% more glucose was consumed, but no obvious co-utilization of xylose was observed. Further glucose fed-batch experiments suggested that the intracellular metabolism of xylose was repressed by glucose.

Conclusions
Through random mutagenesis and partial deletion coupled with high-throughput screening, a mutant of the Glf transporter (2-RD5) was obtained that relieved the inhibition of xylose transport by glucose. The fermentation tests revealed that 2-RD5 was advantageous in xylose and glucose uptakes, while no obvious advantage was seen for xylose co-consumption when co-fermented with glucose. Further efforts could focus on reducing CCR-mediated repression of intracellular metabolism of xylose. Glf should also serve as a useful model to further exploit the molecular mechanism of xylose transport and the CCR-mediated inhibition.
2-Deoxy-D-glucose enhances TRAIL-induced apoptosis in human melanoma cells through XBP-1-mediated up-regulation of TRAIL-R2
Authors: Liu Hao , Jiang Chen Chen , Lavis Christopher J , Croft Amanda , Dong Li , Tseng Hsin-Yi , Yang Fan , Tay Kwang Hong , Hersey Peter , Zhang Xu Dong 
Published: December 2009

Abstract

Background
Past studies have shown that sensitivity of melanoma cells to TRAIL-induced apoptosis is largely correlated with the expression levels of TRAIL death receptors on the cell surface. However, fresh melanoma isolates and melanoma tissue sections express generally low levels of death receptors for TRAIL. The clinical potential of TRAIL in the treatment of melanoma may therefore be limited unless given with agents that increase the cell surface expression of TRAIL death receptors. 2-Deoxy-D-glucose (2-DG) is a synthetic glucose analogue that inhibits glycolysis and glycosylation and blocks cell growth. It has been in clinical evaluation for its potential use as an anticancer agent. In this study, we have examined whether 2-DG and TRAIL interact to enhance their cytotoxicity towards melanoma cells.

Results
2-DG did not kill melanoma cells, but enhanced TRAIL-induced apoptosis in cultured melanoma cells and fresh melanoma isolates. This was associated with increased activation of the caspase cascade and mitochondrial apoptotic pathway, and was blocked by inhibition of TRAIL-R2, and to a lesser extent, inhibition of TRAIL-R1. Treatment with 2-DG up-regulated TRAIL death receptors, in particular, TRAIL-R2, on the melanoma cell surface. Up-regulation of TRAIL-R2 was due to increased transcription that was not dependent on the transcription factors, p53 and CHOP. Instead, the IRE1α and ATF6 pathways of the unfolded protein response that were activated by 2-DG appeared to be involved. Moreover, XBP-1, which is known to be transcriptionally regulated by ATF6 and functionally activated by IRE1α, was found to play an important role in 2-DG-mediated transcriptional up-regulation of TRAIL-R2 in melanoma cells.

Conclusion
These results indicate that 2-DG sensitizes human melanoma cells to TRAIL-induced apoptosis by up-regulation of TRAIL-2 via the ATF6/IRE1α/XBP-1 axis of the unfolded protein response. They suggest that 2-DG is a promising agent to increase the therapeutic response to TRAIL in melanoma.
Adolescents' wellbeing and functioning: relationships with parents' subjective general physical and mental health
Authors: Giannakopoulos George , Dimitrakaki Christine , Pedeli Xanthi , Kolaitis Gerasimos , Rotsika Vasiliki , Ravens-Sieberer Ulricke , Tountas Yannis 
Published: December 2009

Abstract

Background
This study aimed at examining the relationship between parental subjective health status and adolescents' health-related quality of life (HRQoL) as well as the role of gender, socioeconomic status, presence of chronic health care needs and social support on the above interaction.

Methods
Questionnaires were administered to a Greek nation-wide random sample of adolescents (N = 1 194) aged 11-18 years and their parents (N = 973) in 2003. Adolescents' and parents' status was assessed, together with reports of socio-economic status and level of social support. Various statistical tests were used to determine the extent to which these variables were related to each other.

Results and Discussion
Parental subjective mental health status was significantly correlated with adolescents' better physical and psychological wellbeing, moods and emotions, parent-child relationships, school environment and financial resources. Parental subjective physical health status was strongly associated with more positive adolescents' self-perception. Adolescents' male gender, younger age, absence of chronic health care needs, high social support, and higher family income were positively associated with better HRQoL.

Conclusions
This study reinforces the importance of parental subjective health status, along with other variables, as a significant factor for the adolescents' HRQoL.
Isolated recurrence of distal adenocarcinoma of the extrahepatic bile duct on a draining sinus scar after curative resection: Case Report and review of the literature
Authors: Rodríguez-Pascual Jesús , De Vicente Emilio , Quijano Yolanda , Pérez-Rodríguez Francisco , Bergaz Fernando , Hidalgo Manuel , Duran Ignacio 
Published: December 2009

Abstract

Background
Surgical resection remains the gold standard for the treatment of localized adenocarcinoma of the extrahepatic bile ducts. Yet, treatment of loco-regional recurrences is not well defined.

Case Presentation
We present an unusual case of distal adenocarcinoma of the extrahepatic bile ducts that was treated with surgery and relapsed two years later with a solitary recurrence on the tract of a previous Redon drain. In addition, a review of the literature on management of loco regional relapses is presented.

Conclusions
The ideal management of these patients still remains undefined. Decisions are made based on clinical parameters from retrospective series, such as tumor grade, surgical margins or lymph node involvement. Prospective studies, that include molecular and genetic markers, are needed to improve patient selection and outcomes on this population.