bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of DICER-LIKE and ARGONAUTE Proteins in TAS-Derived Small Interfering RNA-Triggered DNA Methylation
Authors: Wu Liang , Mao Long , Qi Yijun 
Published: July 2012

Abstract
Trans-acting small interfering RNAs (ta-siRNAs; TAS) emerge as a class of plant-specific small RNAs that are initiated from microRNA-mediated cleavage of TAS gene transcripts. It has been revealed that ta-siRNAs are generated by the sequential activities of SUPPRESSOR OF GENE SILENCING3 (SGS3), RNA-DEPENDENT RNA POLYMERASE6 (RDR6), and DICER-LIKE4 (DCL4), and loaded into ARGONAUTE1 (AGO1) proteins to posttranscriptionally regulate several target genes by messenger RNA cleavage in trans. Here, we showed a high cytosine DNA methylation status at ta-siRNA-generating loci in Arabidopsis (Arabidopsis thaliana), which is dependent on RDR6, SGS3, and DNA-DIRECTED RNA POLYMERASE V (PolV). More important, we found that DCL1 is the only DCL protein that is required for TAS3 loci DNA methylation, and all four DCLs exert combinatory functions in the methylation of TAS1 loci, suggesting a previously unknown role for DCL1 in directly processing TAS gene transcripts. Furthermore, we demonstrated that AGO4/6 complexes rather than AGO1 are responsible for TAS siRNA-guided DNA methylation. Based upon these findings, we propose a novel ta-siRNA pathway that acts at both the messenger RNA and chromatin level.
Hepatitis B virus surface antigen can activate human monocyte‐derived dendritic cells by nuclear factor kappa B and p38 mitogen‐activated protein kinase mediated signaling
Authors: Jan Rong‐Hwa , Lin Yu‐Li , Chen Chia‐Jung , Lin Teng‐Yi , Hsu Ya‐Chun , Chen Li‐Kuang , Chiang Bor‐Luen 
Published: July 2012

ABSTRACTHepatitis B virus Ag (HBsAg), a major antigen of hepatitis B virus (HBV), is also a vaccine component for prevention of HBV infection. Dendritic cells (DCs) of HBV carriers reportedly exhibit functional impairment. In this study, the aim was to investigate the effect of HBsAg on activation of human monocyte‐derived dendritic cells (MD‐DCs), and the subsequent signal transduction pathway. Treatment of MD‐DCs with HBsAg resulted in enhanced cell surface expression of cluster of differentiation 80, CD83, CD86 and major histocompatibility complex class II, and increased interleukin (IL)‐12 p40, IL‐12p70, and IL‐10 production. Furthermore, HBsAg treatment of MD‐DCs with HBsAg resulted in enhanced T cell‐stimulatory capacity and increased T cell secretion of interferon and IL‐10. The pathway of MD‐DCs activation by HBsAg was further investigated in the present study. Inhibition of nuclear factor (NF)‐kappa B (κB) by helenalin and p38 mitogen‐activated protein kinase (MAPK) by SB203580 prevented production of IL‐12 p40, IL‐12 p70, and IL‐10. HBsAg also augmented MAPK phosphorylation. Thus, cytokine secretion of human MD‐DCs by HBsAg is blocked by inhibition of the NF‐κB and p38 MAPK pathways. Likewise, decreased inhibition of kappa B alpha concentrations and MAPK phosphorylation are critical for MD‐DC maturation by HBsAg. These findings may provide a strategy for improving the prophylactic and therapeutic efficacy of vaccines and tumor therapies that utilize these pathways.
Impact of central nervous system (CNS) prophylaxis on the incidence and risk factors for CNS relapse in patients with diffuse large B‐cell lymphoma treated in the rituximab era: a single centre experience and review of the literature
Authors: Guirguis Hany R. , Cheung Matthew C. , Mahrous Mervat , Piliotis Eugenia , Berinstein Neil , Imrie Kevin R. , Zhang Liying , Buckstein Rena 
Published: July 2012

SummaryCentral nervous system (CNS) prophylaxis for diffuse large B‐cell lymphoma (DLBCL) is controversial with even less evidence in the era of R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy. We reviewed the impact of CNS prophylaxis in DLBCL patients treated with R‐CHOP at a tertiary care centre over a 7‐year period. CNS prophylaxis was recommended for ‘higher risk’ patients and consisted of intrathecal methotrexate and/or high‐dose methotrexate. Of 214 patients 12·6% received CNS prophylaxis. With a median follow‐up of 27 months, eight patients (3·7%) developed CNS relapse (75% isolated to the CNS and 62·5% as parenchymal brain disease) at a median time of 17 months. Patients who did not receive CNS prophylaxis had lower events (2·7%) than those who did (11·1%). Half of the CNS relapses occurred in testicular lymphoma patients, 75% of whom had received CNS prophylaxis. In multivariate analysis, testicular involvement was the only significant prognostic factor for CNS relapse (hazard ratio 33·5, P < 0·001). In conclusion, CNS relapse in DLBCL appears to present as a later, more isolated parenchymal event and at a lower rate in the rituximab era compared with historical data. R‐CHOP may negate the need for CNS prophylaxis with the exception of testicular lymphoma.
Epidemiology, mortality rate and survival in a homogeneous population of hypopituitary patients
Authors: Fernandez‐Rodriguez E. , Lopez‐Raton M. , Andujar P. , Martinez‐Silva I. M. , Cadarso‐Suarez C. , Casanueva F. F. , Bernabeu I. 
Published: July 2012

SummaryIntroductionHypopituitarism is associated with higher prevalence of cardiovascular risk factors and premature death. Furthermore, some clinical and therapeutic features of hypopituitarism have been associated with a worse prognosis.ObjectiveWe reviewed, retrospectively, a large series of adult patients with hypopituitarism using stringent epidemiological criteria. Prevalence, association with cardiovascular risk factors, mortality and survival have been analysed.Design and MethodsTwo hundred and nine adult hypopituitary patients (56·9% females) from a population of 405 218 inhabitants, followed for 10 years.ResultsPrevalence of hypopituitarism at the end of the study was 37·5 cases/100 000 inhabitants. Incidence of hypopituitarism was 2·07 cases/100 000 inhabitants and year. Thirty‐two patients died during the period of the study. Standardized mortality rate (SMR) was 8·05, higher in males (8·92vs7·34) and in younger patients (84·93vs5·26). Diagnosis of acromegaly (P = 0·033), previous radiotherapy (P = 0·02), higherBMI(P = 0·04), diabetes mellitus (P = 0·03) and cancer (P < 0·0001) were associated with mortality. A lower survival was associated with older age at diagnosis, nontumoural causes, previous radiotherapy, diabetes mellitus with poor metabolic control and malignant disease.ConclusionsPrevalence of hypopituitarism was 37·5 cases/100 000 inhabitants, and annual incidence was 2·07 cases/100 000 inhabitants.SMRwas 8 times higher in hypopituitarism than in general population and was also higher in males and younger patients. Reduced survival was significantly related to cancer, nontumoural causes of hypopituitarism, older age at diagnosis, previous radiotherapy and diabetes mellitus with poor metabolic control.
Acoustic radiation force impulse imaging for non‐invasive assessment of liver fibrosis in chronic hepatitis B
Authors: Friedrich‐Rust M. , Buggisch P. , de Knegt R. J. , Dries V. , Shi Y. , Matschenz K. , Schneider M. D. , Herrmann E. , Petersen J. , Schulze F. , Zeuzem S. , Sarrazin C. 
Published: July 2012

SummaryAcoustic radiation force impulse (ARFI) imaging is a novel ultrasound‐based elastography method that is integrated in a conventional ultrasound machine. It might provide an alternative method to transient elastography for the noninvasive assessment of liver fibrosis. While previous studies have shown comparable diagnostic accuracy of ARFI to transient elastography in chronic hepatitis C, the aim of the present prospective multicenter study was to evaluate ARFI for the assessment of liver fibrosis in chronic hepatitis B. ARFI imaging involves the mechanical excitation of tissue using short‐duration acoustic pulses to generate localized displacements in tissue. The displacements result in shear‐wave propagation which is tracked using ultrasonic, correlation‐based methods and recorded in m/s. In the present international prospective study, patients infected with chronic hepatitis B received ARFI imaging, blood tests and if available transient elastography. The results were compared to liver biopsy as reference method analysed by a central pathologist. In 92 of 114 patients, a comparison of ARFI with transient elastography was possible. ARFI imaging and transient elastography correlated significantly with histological fibrosis stage. The diagnostic accuracy expressed as areas under ROC curves for ARFI imaging and transient elastography was 0.75 and 0.83 for the diagnosis of significant fibrosis (F ≥ 2), 0.93 and 0.94 for the diagnosis of severe fibrosis (F ≥ 3), and 0.97 and 0.93 for the diagnosis of liver cirrhosis, respectively. No significant difference was found between ARFI and transient elastography. ARFI imaging is a reliable ultrasound‐based method for the assessment of advanced stages of liver fibrosis in chronic hepatitis B.
Factors associated with HCV antiviral treatment uptake among participants of a community‐based HCV programme for marginalized patients
Authors: Charlebois A. , Lee L. , Cooper E. , Mason K. , Powis J. 
Published: July 2012

SummaryWhile the majority of cases of hepatitis C virus (HCV) in developed countries occur among illicit drug users, HCV antiviral treatment uptake is poor in this population. Several studies have shown that patients can successfully be treated for HCV in the context of methadone maintenance programmes, but little evidence exists evaluating HCV treatment models for substance users where methadone maintenance is not indicated. This retrospective cohort study involved 129 persons participating in psycho‐educational support groups and integrated, interprofessional, community‐based health services focused on the treatment for HCV among marginalized populations with high rates of crack cocaine use and mental health comorbidities. We sought to identify the factors associated with antiviral treatment uptake. Group participation improved access to health care. While 19% had previously seen an HCV specialist prior to group initiation, 59% saw an HCV specialist during the group. Half of the participants were nonimmune to hepatitis A or B at baseline, and 80% of these patients received immunization through the programme. The programme treated 24 patients with pegylated interferon and ribavirin and achieved a sustained virologic response (SVR) rate of 91% for genotype 2 or 3 and 54% for genotype 1. Stable housing was independently associated with initiation of treatment, and there was a nonsignificant trend towards lower rates of treatment initiation among women. SVR rates for those who had used crack or injection drugs in the month prior to joining the programme did not differ significantly from those who had abstained.
A parapatric propensity for breeding precludes the completion of speciation in common teal (Anas crecca, sensu lato)
Authors: PETERS JEFFREY L. , McCRACKEN KEVIN G. , PRUETT CHRISTIN L. , ROHWER SIEVERT , DROVETSKI SERGEI V. , ZHURAVLEV YURIY N. , KULIKOVA IRINA , GIBSON DANIEL D. , WINKER KEVIN 
Published: July 2012

AbstractSpeciation is a process in which genetic drift and selection cause divergence over time. However, there is no rule dictating the time required for speciation, and even low levels of gene flow hinder divergence, so that taxa may be poised at the threshold of speciation for long periods of evolutionary time. We sequenced mitochondrial DNA (mtDNA) and eight nuclear introns (nuDNA) to estimate genomic levels of differentiation and gene flow between the Eurasian common teal (Anas crecca crecca) and the North American green‐winged teal (Anas crecca carolinensis). These ducks come into contact in Beringia (north‐eastern Asia and north‐western North America) and have probably done so, perhaps cyclically, since the Pliocene–Pleistocene transition, ∼2.6 Ma, when they apparently began diverging. They have diagnosable differences in male plumage and are 6.9% divergent in the mtDNA control region, with only 1 of 58 crecca and 2 of 86 carolinensis having haplotypes grouping with the other. Two nuclear loci were likewise strongly structured between these teal (Φst ≥ 0.35), but six loci were undifferentiated or only weakly structured (Φst = 0.0–0.06). Gene flow between crecca and carolinensis was ∼1 individual per generation in both directions in mtDNA, but was asymmetrical in nuDNA, with ∼1 and ∼20 individuals per generation immigrating into crecca and carolinensis, respectively. This study illustrates that species delimitation using a single marker oversimplifies the complexity of the speciation process, and it suggests that even with divergent selection, moderate levels of gene flow may stall the speciation process short of completion.
Phylogeography of speciation: allopatric divergence and secondary contact between outcrossing and selfingClarkia
Authors: PETTENGILL JAMES B. , MOELLER DAVID A. 
Published: July 2012

AbstractThe origins of hybrid zones between parapatric taxa have been of particular interest for understanding the evolution of reproductive isolation and the geographic context of species divergence. One challenge has been to distinguish between allopatric divergence (followed by secondary contact) versus primary intergradation (parapatric speciation) as alternative divergence histories. Here, we use complementary phylogeographic and population genetic analyses to investigate the recent divergence of two subspecies ofClarkia xantianaand the formation of a hybrid zone within the narrow region of sympatry. We tested alternative phylogeographic models of divergence using approximate Bayesian computation (ABC) and found strong support for a secondary contact model and little support for a model allowing for gene flow throughout the divergence process (i.e. primary intergradation). Two independent methods for inferring the ancestral geography of each subspecies, one based on probabilistic character state reconstructions and the other on palaeo‐distribution modelling, also support a model of divergence in allopatry and range expansion leading to secondary contact. The membership of individuals to genetic clusters suggests geographic substructure within each taxon where allopatric and sympatric samples are primarily found in separate clusters. We also observed coincidence and concordance of genetic clines across three types of molecular markers, which suggests that there is a strong barrier to gene flow. Taken together, our results provide evidence for allopatric divergence followed by range expansion leading to secondary contact. The location of refugial populations and the directionality of range expansion are consistent with expectations based on climate change since the last glacial maximum. Our approach also illustrates the utility of combining phylogeographic hypothesis testing with species distribution modelling and fine‐scale population genetic analyses for inferring the geography of the divergence process.
Environmental risk assessment for the small tortoiseshell Aglais urticae and a stacked Bt‐maize with combined resistances against Lepidoptera and Chrysomelidae in central European agrarian landscapes
Authors: SCHUPPENER MECHTHILD , MÜHLHAUSE JULIA , MÜLLER ANNE‐KATRIN , RAUSCHEN STEFAN 
Published: July 2012

AbstractThe cultivation of Lepidoptera‐resistant Bt‐maize may affect nontarget butterflies. We assessed the risk posed by event MON89034 × MON88017 (expressing Cry1A.105 and Cry2Ab2 against corn borers) to nontarget Lepidoptera. Using the small tortoiseshell Aglais urticae, a butterfly species common in central Europe, as a test organism we (i) assessed the toxicity of Bt‐maize pollen on butterfly larvae; (ii) measured pollen deposition on leaves of the host plant Urtica dioica; (iii) mapped the occurrence and distribution of host plants and larvae in two arable landscapes in Germany during maize anthesis; and (iv) described the temporal occurrence of a 1‐year population of A. urticae. (i) Larvae‐fed 200 Bt‐maize pollen grains/cm2 had a reduced feeding activity. Significant differences in developmental time existed at pollen densities of 300 Bt‐maize pollen grains/cm2 and in survival at 400 grains/cm2. (ii) The highest pollen amount found was 212 grains/cm2 at the field margin. Mean densities were much lower. (iii) In one region, over 50% of A. urticae nests were located within 5 m of a maize field, while in the other, all nests were found in more than 25 m distance to a maize field. (iv) The percentage of larvae developing during maize anthesis was 19% in the study area. The amount of pollen from maize MON89034 × MON88017 found on host plants is unlikely to adversely affect a significant proportion of larvae of A. urticae. This paper concludes that the risk of event MON89034 × MON88017 to populations of this species is negligible.
Diastolic dysfunction, prolonged QTc interval and pericardial effusion as predictors of mortality in acute pancreatitis
Authors: Nadkarni Nikhil , Bhasin Deepak Kumar , Rana Surinder Singh , Bahl Ajay , Sinha Saroj Kant , Rao Chalapathi , Talwar Kewal Kishan 
Published: July 2012

AbstractBackground and AimThe cardiac changes in acute pancreatitis have been earlier studied but the data on their prognostic significance is limited. This study was done to determine electrocardiographic (ECG) and echocardiographic changes in acute pancreatitis and determine their prognostic significance.MethodsFifty‐two consecutive patients (mean age 36.5 ± 11 years (44 males)) with acute pancreatitis and without prior cardiovascular comorbidites were prospectively enrolled and subjected to clinical, laboratory and radiological investigation. ECG and echocardiography was done at admission and during follow up.ResultsSeventeen patients (32.7%) had mild pancreatitis and 35 (67.3%) patients had severe pancreatitis. Sinus tachycardia was the most common ECG abnormality. QTc prolongation was seen in 30/52 (57.7%) patients. On echocardiography, no patient had systolic dysfunction but 31/52 (59.6%) patients had diastolic dysfunction. All 22 patients with QTc interval < 440 ms survived compared with 8/30 patients with QTc interval ≥ 440 ms who died (P = 0.01). All eight patients who died had evidence of diastolic dysfunction (100%). None of the patients without diastolic dysfunction succumbed to illness (P = 0.02). Pericardial effusion was present in 6/52 (11.5%) patients. Of the eight patients who died, pericardial effusion was present in three (37.5%) patients and this frequency was significantly higher than that in patients who recovered (3/44 [6.8%]; P = 0.04).ConclusionElectrocardiographic and echocardiographic changes are seen in more than 50% of patients with acute pancreatitis. Prolonged QTc interval, pericardial effusion and diastolic dysfunction are associated with higher mortality.
Early angiographic embolization is more effective than delayed angiographic embolization in patients with duodenal ulcer bleeding
Authors: Lee Seok , Kim Sang Wook , Moon Jin Chang , Jang Ji Won , Kim Heyoung Il , Park Won Seok , Jeon Byung Jun , Sohn Ji Youn , Kim Seong Hun , Kim In Hee , Lee Seung Ok , Lee Soo Teik 
Published: July 2012

AbstractBackground and AimThough angiographic embolization (AE) is a type of effective treatment modality for duodenal ulcer bleeding, the optimum time at which to perform the procedure, early or delayed, is unknown. The authors compared the prognosis of early AE (EAE) and delayed AE (DAE) in patients with duodenal ulcer bleeding.MethodsA total of 54 patients with duodenal ulcer bleeding were evaluated with first‐look endoscopy followed by AE. The patients were divided into two groups, the EAE group and DAE group, according to endoscopic attempts to stop the bleeding during the first‐look endoscopy.ResultsThe success rate of AE, rebleeding rate, and number of patients who underwent surgery was not significantly different between the EAE group and DAE group (91.3% vs 93.5%, 21.7% vs 29.0% and 4.3% vs 16.1%, respectively; P > 0.05). With respect to death and intensive care unit (ICU) care rate, multivariate analysis showed more favorable results in the EAE group (0% vs 22.6%, P = 0.016 and 4.3% vs 57.4%, P = 0.003, respectively). Multivariate analysis also showed that prolonged prothrombin time (PT) > 1.2 international normalized ratio and the endoscopic attempt were independent factors associated with ICU care.ConclusionWhen the AE was performed early with correction for prolonged PT, the patients with duodenal ulcer bleeding had a more favorable prognosis.
Role of intervention for biliary and gastric/intestinal obstruction in gastric cancer with peritoneal metastasis
Authors: Nakai Yousuke , Ishigami Hironori , Isayama Hiroyuki , Sasaki Takashi , Kawakubo Kazumichi , Kogure Hirofumi , Emoto Shigenobu , Yamaguchi Hironori , Kitayama Joji , Yamamoto Natsuyo , Sasahira Naoki , Hirano Kenji , Tada Minoru , Koike Kazuhiko 
Published: July 2012

AbstractBackground and AimGastrointestinal (GI) luminal obstruction or malignant biliary obstruction (MBO) is not a rare condition in gastric cancer patients with peritoneal metastasis. The role of endoscopic or percutaneous interventions is not fully elucidated in this setting.MethodsA total of 123 patients with unresectable or recurrent gastric adenocarcinoma with peritoneal metastasis receiving intravenous and intraperitoneal paclitaxel combined with S‐1 were retrospectively studied. Safety and efficacy of interventions for GI luminal obstruction and MBO were evaluated.ResultsA total of 27 patients (22%) underwent GI luminal and/or biliary interventions; GI luminal alone in 10, biliary alone in 10 and both in seven, with a technical success rate of 100%. Clinical success rate was 65% in self‐expandable metallic stents (SEMS) placement for GI luminal obstruction. Eastern Cooperative Oncology Group (ECOG) performance status (PS) was prognostic of clinical success in GI luminal stenting (100% in PS of 1 vs 14% in PS of 2–3, P < 0.001). Biliary drainage (endoscopic SEMS placement in four and percutaneous transhepatic biliary drainage in 12) relieved obstructive jaundice in 94%. Six complications were observed: four after GI luminal stenting (two occlusion and one aspiration pneumonia) and two after biliary stenting (one cholangitis and one cholecystitis). Median survival after the initial intervention was 5.7 months. PS at interventions was prognostic of survival after interventions (12.3 months in PS of 1 vs 2.2 months in PS of 2 or 3, P < 0.001).ConclusionEndoscopic or percutaneous interventions for GI luminal obstruction or MBO were feasible and effective in gastric cancer patients with peritoneal dissemination receiving combination chemotherapy.
Selective bronchial intubation in a preterm infant with congenital cystic adenomatoid malformation and pulmonary air leak syndrome
Authors: Balegar V Kiran Kumar , Barr Peter A , McCauley James Charles , Thomas Gordon 
Published: July 2012

AbstractA preterm infant with congenital cystic adenomatoid malformation (CCAM) who developed a right‐sided pulmonary air leak syndrome (pulmonary interstitial emphysema and bronchopleural fistula) following CCAM resection is reported. The pulmonary air leak syndrome was successfully ameliorated by intubating the right mainstem bronchus using a modified endotracheal tube that allowed selective ventilation of the left lung. The procedure was used successfully as rescue treatment to control the pulmonary air leak and to confirm the functional adequacy of the left lung prior to definitive operative surgery.