bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model system for the analysis of cell surface expression of human ABCA1
Authors: Kasza Ildikó , Hegyi Zoltán , Szabó Katalin , Andrikovics Hajnalka , Német Katalin , Váradi András , Sarkadi Balázs , Homolya László 
Published: December 2009

Abstract

Background
The ABCA1 protein plays a pivotal role in reverse cholesterol transport, by mediating the generation of HDL particles and removing cellular cholesterol. Both the proper expression of ABCA1 in the plasma membrane and the internalization along with apoA-I are required for function. Therefore, we developed a model system to investigate the effect of clinically relevant drugs on the cell surface appearance of ABCA1.

Results
By retroviral transduction system, we established stable mammalian cell lines expressing functional and non-functional ABCA1 variants, tagged with an extracellular hemagglutinin epitope. After characterization of the expression, proper localization and function of different ABCA1 variants, we followed quantitatively their cell surface expression by immunofluorescent staining, using flow cytometry. As expected, we found increased cell surface expression of ABCA1 after treatment with a calpain inhibitor, and observed a strong decrease in plasma membrane ABCA1 expression upon treatment with a trans-Golgi transport inhibitor, Brefeldin A. We tested cholesterol level lowering drugs and other potential inhibitors of ABCA1. Here we demonstrate that ezetimibe affects ABCA1 cell surface expression only in the case of a functional ABCA1.

Conclusions
Our model system allows a quantitative detection of cell surface expression of ABCA1, screening of substrates or specific inhibitors, and investigating transport regulation.
Genome-wide profiling of Populus small RNAs
Authors: Klevebring Daniel , Street Nathaniel R , Fahlgren Noah , Kasschau Kristin D , Carrington James C , Lundeberg Joakim , Jansson Stefan 
Published: December 2009

Abstract

Background
Short RNAs, and in particular microRNAs, are important regulators of gene expression both within defined regulatory pathways and at the epigenetic scale. We investigated the short RNA (sRNA) population (18-24 nt) of the transcriptome of green leaves from the sequenced Populus trichocarpa using a concatenation strategy in combination with 454 sequencing.

Results
The most abundant size class of sRNAs were 24 nt. Long Terminal Repeats were particularly associated with 24 nt sRNAs. Additionally, some repetitive elements were associated with 22 nt sRNAs. We identified an sRNA hot-spot on chromosome 19, overlapping a region containing both the proposed sex-determining locus and a major cluster of NBS-LRR genes. A number of phased siRNA loci were identified, a subset of which are predicted to target PPR and NBS-LRR disease resistance genes, classes of genes that have been significantly expanded in Populus. Additional loci enriched for sRNA production were identified and characterised. We identified 15 novel predicted microRNAs (miRNAs), including miRNA*sequences, and identified a novel locus that may encode a dual miRNA or a miRNA and short interfering RNAs (siRNAs).

Conclusions
The short RNA population of P. trichocarpa is at least as complex as that of Arabidopsis thaliana. We provide a first genome-wide view of short RNA production for P. trichocarpa and identify new, non-conserved miRNAs.
The commonly-used DNA probe for diffusely-adherent Escherichia coli cross-reacts with a subset of enteroaggregative E. coli
Authors: Snelling Anna M , Macfarlane-Smith Louissa R , Fletcher Jonathan N , Okeke Iruka N 
Published: December 2009

Abstract

Background
The roles of diffusely-adherent Escherichia coli (DAEC) and enteroaggregative E. coli (EAEC) in disease are not well understood, in part because of the limitations of diagnostic tests for each of these categories of diarrhoea-causing E. coli. A HEp-2 adherence assay is the Gold Standard for detecting both EAEC and DAEC but DNA probes with limited sensitivity are also employed.

Results
We demonstrate that the daaC probe, conventionally used to detect DAEC, cross-reacts with a subset of strains belonging to the EAEC category. The cross hybridization is due to 84% identity, at the nucleotide level, between the daaC locus and the aggregative adherence fimbriae II cluster gene, aafC, present in some EAEC strains. Because aaf-positive EAEC show a better association with diarrhoea than other EAEC, this specific cross-hybridization may have contributed to an over-estimation of the association of daaC with disease in some studies. We have developed a discriminatory PCR-RFLP protocol to delineate EAEC strains detected by the daaC probe in molecular epidemiological studies.

Conclusions
A PCR-RFLP protocol described herein can be used to identify aaf-positive EAEC and daaC-positive DAEC and to delineate these two types of diarrhoeagenic E. coli, which both react with the daaC probe. This should help to improve current understanding and future investigations of DAEC and EAEC epidemiology.
Growth in glucose-based medium and exposure to subinhibitory concentrations of imipenem induce biofilm formation in a multidrug-resistant clinical isolate of Acinetobacter baumannii
Authors: Nucleo Elisabetta , Steffanoni Laura , Fugazza Giulia , Migliavacca Roberta , Giacobone Ernesto , Navarra Antonella , Pagani Laura , Landini Paolo 
Published: December 2009

Abstract

Background

Acinetobacter baumannii is emerging as an important nosocomial pathogen. Multidrug resistance, as well as ability to withstand environmental stresses, makes eradication of A. baumannii difficult, particularly from hospital settings.

Results
Over a six-year period, 73 isolates of A. baumannii were collected from infected patients in two hospitals in Italy. While 69 out of the 73 isolates displayed identical multidrug antibiotic resistance pattern, they were susceptible to carbapenems. Genetic profiles of these 69 isolates, determined by Pulsed Field Gel Electrophoresis (PFGE), indicated that they were genetically related and could be clustered in a specific clone, called SMAL. We tested the ability of the SMAL clone to form biofilm, an important determinant for bacterial colonization of the human host and for persistence in the hospital environment. Biofilm formation by A. baumannii SMAL, measured as surface adhesion to polystyrene, is strongly affected by growth conditions, being impaired in rich growth media such as LB, while being favoured in glucose-based medium. Surface adhesion in glucose-based media is inhibited by treatment with cellulase, suggesting that it depends on production of cellulose or of a chemically related extracellular polysaccharide. Exposure of A. baumannii SMAL to subinhibitory concentrations of imipenem resulted in biofilm stimulation and increased production of iron uptake proteins. Growth in iron-supplemented medium also stimulated surface adhesion, thus suggesting that increased intracellular iron concentrations might act as an environmental signal for biofilm formation in A. baumannii SMAL.

Conclusions
Our results indicate that exposure to subinhibitory concentrations of imipenem can stimulate biofilm formation and induce iron uptake in a pathogenic strain of A. baumannii, with potential implications on antibiotic susceptibility and ability to persist in the human host.
Intrinsic chemoresistance to gemcitabine is associated with constitutive and laminin-induced phosphorylation of FAK in pancreatic cancer cell lines
Authors: Huanwen Wu , Zhiyong Liang , Xiaohua Shi , Xinyu Ren , Kai Wang , Tonghua Liu 
Published: December 2009

Abstract

Background
One of the major reasons for poor prognosis of pancreatic cancer is its high resistance to currently available chemotherapeutic agents. In recent years, focal adhesion kinase (FAK), a central molecule in extracellular matrix (ECM)/integrin-mediated signaling, has been thought to be a key determinant of chemoresistance in cancer cells. In this study, we aimed to determine the roles of FAK phosphorylation in the intrinsic chemoresistance of pancreatic cancer cell lines.

Results
Our results showed that, the level of constitutive phosphorylation of FAK at Tyr397 correlated with the extent of intrinsic resistance to Gemcitabine (Gem) in four pancreatic cancer cell lines. Moreover, in Panc-1 cells, which had high expression of pFAK, specific inhibition of constitutive FAK phosphorylation by either RNAi or FRNK overexpression decreased the phosphorylation of Akt, reduced the levels of survivin expression and Bad phosphorylation at Ser136 and increased Gem-induced cytotoxicity and apoptosis. However, in AsPC-1 cells with a low level of pFAK, neither FAK RNAi nor FRNK overexpression affected Gem-induced cell apoptosis. We further found that laminin (LN) induced FAK and Akt phosphorylation in a time-dependent manner, increased the levels of survivin and pBad (pS136) and decreased Gem-induced cytotoxicity and apoptosis in AsPC-1 cells; Specific inhibition of LN-induced FAK phosphorylation by either FAK RNAi or FRNK overexpression suppressed the effects of LN on AsPC-1 cells. Moreover, inhibition of constitutive FAK phosphorylation in Panc-1 cells and LN-induced FAK phosphorylation in AsPC-1 cells by a novel and more specific FAK phosphorylation inhibitor PF-573,228 showed similar results with those of FAK phosphorylation inhibition by FAK RNAi or FRNK overexpression.

Conclusions
In conclusion, our research demonstrates for the first time that both constitutive and LN-induced FAK phosphorylation contribute to increased intrinsic chemoresistance to Gem in pancreatic cancer cell lines and these effects are partly due to the regulation of Akt and Bad phosphorylation and survivin expression. Development of selective FAK phosphorylation inhibitors may be a promising way to enhance chemosensitivity in pancreatic cancer.
Effect of filtration on morphine and particle content of injections prepared from slow-release oral morphine tablets
Authors: McLean Stuart , Bruno Raimondo , Brandon Susan , de Graaff Barbara 
Published: December 2009

Abstract

Background
Injections of mixtures prepared from crushed tablets contain insoluble particles which can cause embolisms and other complications. Although many particles can be removed by filtration, many injecting drug users do not filter due to availability, cost or performance of filters, and also due to concerns that some of the dose will be lost.

Methods
Injection solutions were prepared from slow-release morphine tablets (MS Contin®) replicating methods used by injecting drug users. Contaminating particles were counted by microscopy and morphine content analysed by liquid chromatography before and after filtration.

Results
Unfiltered tablet extracts contained tens of millions of particles with a range in sizes from < 5 μm to > 400 μm. Cigarette filters removed most of the larger particles (> 50 μm) but the smaller particles remained. Commercial syringe filters (0.45 and 0.22 μm) produced a dramatic reduction in particles but tended to block unless used after a cigarette filter. Morphine was retained by all filters but could be recovered by following the filtration with one or two 1 ml washes. The combined use of a cigarette filter then 0.22 μm filter, with rinses, enabled recovery of 90% of the extracted morphine in a solution which was essentially free of tablet-derived particles.

Conclusions
Apart from overdose and addiction itself, the harmful consequences of injecting morphine tablets come from the insoluble particles from the tablets and microbial contamination. These harmful components can be substantially reduced by passing the injection through a sterilizing (0.22 μm) filter. To prevent the filter from blocking, a preliminary coarse filter (such as a cigarette filter) should be used first. The filters retain some of the dose, but this can be recovered by following filtration with one or two rinses with 1 ml water. Although filtration can reduce the non-pharmacological harmful consequences of injecting tablets, this remains an unsafe practice due to skin and environmental contamination by particles and microorganisms, and the risks of blood-borne infections from sharing injecting equipment.
Correlation between expression of p53, p21/WAF1, and MDM2 proteins and their prognostic significance in primary hepatocellular carcinoma
Authors: Zhang Mei-Fang , Zhang Zhi-Yi , Fu Jia , Yang Yu-Feng , Yun Jing-Ping 
Published: December 2009

Abstract

Background
Tumor Protein p53 (p53), cyclin-dependent kinase inhibitor 1A (p21/WAF1), and murine double minute 2 (MDM2) participate in the regulation of cell growth. Altered expression of these gene products has been found in malignant tumors and has been associated with poor prognosis. Our aim was to investigate the expression of the 3 proteins in hepatocellular carcinoma (HCC) and their prognostic significance.

Methods
We examined p53, p21/WAF1, and MDM2 expression in 181 pairs of HCC tissues and the adjacent hepatic tissues by performing immunohistochemistry and examined the expression of the 3 proteins in 7 pairs of HCC tissues and the adjacent hepatic tissues by using western blot analysis.

Results
The expression of p53, p21/WAF1, and MDM2 in the HCC tissues was significantly higher than those in the adjacent hepatic tissues (P < 0.05). A statistical correlation was observed between p53 and p21/WAF1 expression in HCC tissues (R = 0.195, P = 0.008). A statistical correlation was observed between expression of p53 and p21/WAF1 (R = 0.380, P = 0.000), p53 and MDM2 (R = 0.299, P = 0.000), p21/WAF1 and MDM2 (R = 0.285, P = 0.000) in 181 liver tissues adjacent to the tumor. Patients with a low pathologic grade HCC (I+II) had a higher tendency to express p53 on tumor cells than the patients with high pathologic grade HCC (III+IV) (P = 0.007). Survival analysis showed that positive p21/WAF1 expression or/and negative MDM2 expression in HCC was a predictor of better survival of patients after tumor resection (P < 0.05).

Conclusions
The proteins p53, p21/WAF1, and MDM2 were overexpressed in all the HCC cases in this study, and p53 and p21/WAF1 overexpression were positively correlated. The expression of p21/WAF1 and MDM2 can be considered as 2 useful indicators for predicting the prognosis of HCC.
Acute hepatitis in three patients with systemic juvenile idiopathic arthritis taking interleukin-1 receptor antagonist
Authors: Canna Scott , Frankovich Jennifer , Higgins Gloria , Narkewicz Michael R , Nash S Russell , Hollister J Roger , Soep Jennifer B , Dragone Leonard L 
Published: December 2009

Abstract

Purpose
We investigated the etiology of acute hepatitis in three children with systemic Juvenile Idiopathic Arthritis (sJIA) taking Interleukin-1 receptor antagonist (IL1RA).

Methods
Laboratory and clinical data for three children with sJIA diagnosed at ages 13 months to 8 years who developed acute hepatitis during treatment with IL1RA were reviewed for evidence of sJIA flare, infection, macrophage activation syndrome (MAS), malignancy, and drug reaction.

Results
In all patients, hepatitis persisted despite cessation of known hepatotoxic drugs and in absence of known infectious triggers, until discontinuation of IL1RA. Liver biopsies had mixed inflammatory infiltrates with associated hepatocellular injury suggestive of an exogenous trigger. At the time of hepatitis, laboratory data and liver biopsies were not characteristic of MAS. In two patients, transaminitis resolved within one week of discontinuing IL1RA, the third improved dramatically in one month.

Conclusions
Although sJIA symptoms improved significantly on IL1RA, it appeared that IL1RA contributed to the development of acute hepatitis. Hepatitis possibly occurred as a result of an altered immune response to a typical childhood infection while on IL1RA. Alternatively, hepatitis could have represented an atypical presentation of MAS in patients with sJIA taking IL1RA. Further investigation is warranted to determine how anti-IL1 therapies alter immune responsiveness to exogenous triggers in patients with immune dysfunction such as sJIA. Our patients suggest that close monitoring for hepatic and other toxicities is indicated when treating with IL1RA.
Spatiotemporal regulation of the cough motor pattern
Authors: Wang Cheng , Saha Sourish , Rose Melanie J , Davenport Paul W , Bolser Donald C 
Published: December 2009

AbstractThe purpose of this study was to identify the spatiotemporal determinants of the cough motor pattern. We speculated that the spatial and temporal characteristics of the cough motor pattern would be regulated separately. Electromyograms (EMG) of abdominal muscles (ABD, rectus abdominis or transversus abdominis), and parasternal muscles (PS) were recorded in anesthetized cats. Repetitive coughing was produced by mechanical stimulation of the lumen of the intrathoracic trachea. Cough inspiratory (CTI) and expiratory (CTE) durations were obtained from the PS EMG. The ABD EMG burst was confined to the early part of CTEand was followed by a quiescent period of varying duration. As such, CTEwas divided into two segments with CTE1defined as the duration of the ABD EMG burst and CTE2defined as the period of little or no EMG activity in the ABD EMG. Total cough cycle duration (CTTOT) was strongly correlated with CTE2(r2>0.8), weakly correlated with CTI(r2<0.3), and not correlated with CTE1(r2<0.2). There was no significant relationship between CTIand CTE1or CTE2. The magnitudes of inspiratory and expiratory motor drive during cough were only weakly correlated with each other (r2<0.36) and were not correlated with the duration of any phase of cough. The results support: a) separate regulation of CTIand CTE, b) two distinct subphases of CTE(CTE1and CTE2), c) the duration of CTE2is a primary determinant of CTTOT, and d) separate regulation of the magnitude and temporal features of the cough motor pattern.
Superior sagittal sinus thrombosis presenting as a continuous headache: a case report and review of the literature
Authors: Gupta Rishi K , Jamjoom Aimun AB , Devkota Upendra P 
Published: December 2009

Abstract
Cerebral venous sinus thrombosis is a rare but dangerous condition, occurring with an incidence of 3-4 cases/million/year. Cerebral venous sinus thrombosis presents a diagnostic challenge due to its varied presentation patterns. We report a case of a 42 year old Nepali man diagnosed with cerebral venous sinus thrombosis after presenting with a week long history of continuous headache. He improved rapidly following prompt anticoagulation. Despite thorough investigation no discernable underlying cause could be found. Our report highlights the value of prompt diagnosis of cerebral venous sinus thrombosis through neuroimaging and the importance of immediate anticoagulation as part of patient management.
HES 130/0.4 impairs haemostasis and stimulates pro-inflammatory blood platelet function
Authors: Sossdorf Maik , Marx Sascha , Schaarschmidt Barbara , Otto Gordon P , Claus Ralf A , Reinhart Konrad , Hartog Christiane S , Lösche Wolfgang 
Published: December 2009

Abstract
Introduction
Hydroxyethyl starch (HES) solutions are widely used for volume replacement therapy but are also known to compromise coagulation, impair renal function and increase long-term mortality. To test the hypotheses that HES 130/0.4 has fewer adverse effects than HES 200/0.5 and exerts anti-inflammatory properties, we compared the effects of HES 130/0.4, HES 200/0.5 and saline on in vitro haemostasis and pro-inflammatory platelet function.

Methods
Whole blood samples from healthy volunteers were mixed with 6% HES 130/0.4, 10% HES 200/0.5, or normal saline to achieve a final haemodilution rate of 10% or 40%. Haemostatic capacity was characterised by thromboelastography (ROTEM) and measurement for FXIIIa activity. Platelet activation and pro-inflammatory platelet functions were characterised by flow cytometry measuring the platelet activation marker CD62P and binding of fibrinogen to platelets as well as the formation of heterotypic platelet-leukocyte conjugates.

Results
Compared with saline, HES 130/0.4 dose-dependently impaired formation and firmness of the fibrin clot but did not affect the fibrin crosslinking activity of FXIIIa. At 40% but not at 10% haemodilution rate, HES 200/0.5 also increased platelet fibrinogen binding and both HES solutions increased expression of CD62P, the main receptor for platelet-leukocyte adhesion. HES 130/0.4 but not HES 200/0.5 increased formation of platelet-neutrophil conjugates and, to a lesser degree, platelet-monocyte conjugates.

Conclusions
Our data demonstrate that HES 130/0.4 has similar adverse effects as HES 200/0.5. In particular, both types of HES impair coagulation capacity and stimulate, rather than attenuate, pro-inflammatory platelet function.
Characterizing the admixed African ancestry of African Americans
Authors: Zakharia Fouad , Basu Analabha , Absher Devin , Assimes Themistocles L , Go Alan S , Hlatky Mark A , Iribarren Carlos , Knowles Joshua W , Li Jun , Narasimhan Balasubramanian , Sidney Steven , Southwick Audrey , Myers Richard M , Quertermous Thomas , Risch Neil , Tang Hua 
Published: December 2009

Abstract
Background
Accurate, high-throughput genotyping allows the fine characterization of genetic ancestry. Here we applied recently developed statistical and computational techniques to the question of African ancestry in African Americans by using data on more than 450,000 single-nucleotide polymorphisms (SNPs) genotyped in 94 Africans of diverse geographic origins included in the HGDP, as well as 136 African Americans and 38 European Americans participating in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study. To focus on African ancestry, we reduced the data to include only those genotypes in each African American determined statistically to be African in origin.

Results
From cluster analysis, we found that all the African Americans are admixed in their African components of ancestry, with the majority contributions being from West and West-Central Africa, and only modest variation in these African-ancestry proportions among individuals. Furthermore, by principal components analysis, we found little evidence of genetic structure within the African component of ancestry in African Americans.

Conclusions
These results are consistent with historic mating patterns among African Americans that are largely uncorrelated to African ancestral origins, and they cast doubt on the general utility of mtDNA or Y-chromosome markers alone to delineate the full African ancestry of African Americans. Our results also indicate that the genetic architecture of African Americans is distinct from that of Africans, and that the greatest source of potential genetic stratification bias in case-control studies of African Americans derives from the proportion of European ancestry.