bluuebunny/crossref_metadata_2025_split huggingface dataset:
The 21-Nucleotide, but Not 22-Nucleotide, Viral Secondary Small Interfering RNAs Direct Potent Antiviral Defense by Two Cooperative Argonautes inArabidopsis thaliana
Authors: Wang Xian-Bing , Jovel Juan , Udomporn Petchthai , Wang Ying , Wu Qingfa , Li Wan-Xiang , Gasciolli Virginie , Vaucheret Herve , Ding Shou-Wei 
Published: April 2011

AbstractArabidopsis thaliana defense against distinct positive-strand RNA viruses requires production of virus-derived secondary small interfering RNAs (siRNAs) by multiple RNA-dependent RNA polymerases. However, little is known about the biogenesis pathway and effector mechanism of viral secondary siRNAs. Here, we describe a mutant of Cucumber mosaic virus (CMV-Δ2b) that is silenced predominantly by the RNA-DEPENDENT RNA POLYMERASE6 (RDR6)-dependent viral secondary siRNA pathway. We show that production of the viral secondary siRNAs targeting CMV-Δ2b requires SUPPRESSOR OF GENE SILENCING3 and DICER-LIKE4 (DCL4) in addition to RDR6. Examination of 25 single, double, and triple mutants impaired in nine ARGONAUTE (AGO) genes combined with coimmunoprecipitation and deep sequencing identifies an essential function for AGO1 and AGO2 in defense against CMV-Δ2b, which act downstream the biogenesis of viral secondary siRNAs in a nonredundant and cooperative manner. Our findings also illustrate that dicing of the viral RNA precursors of primary and secondary siRNA is insufficient to confer virus resistance. Notably, although DCL2 is able to produce abundant viral secondary siRNAs in the absence of DCL4, the resultant 22-nucleotide viral siRNAs alone do not guide efficient silencing of CMV-Δ2b. Possible mechanisms for the observed qualitative difference in RNA silencing between 21- and 22-nucleotide secondary siRNAs are discussed.
Rice APOPTOSIS INHIBITOR5 Coupled with Two DEAD-Box Adenosine 5′-Triphosphate-Dependent RNA Helicases Regulates Tapetum Degeneration
Authors: Li Xingwang , Gao Xinqiang , Wei Yi , Deng Li , Ouyang Yidan , Chen Guoxing , Li Xianghua , Zhang Qifa , Wu Changyin 
Published: April 2011

AbstractProgrammed cell death (PCD) during tapetum degeneration in postmeiotic anthers is critical for the proper development of male gametophytes in flowering plants. Although several genes involved in this process have been identified recently, the molecular mechanism is still poorly understood. Here, we show that knockout of rice (Oryza sativa) APOPTOSIS INHIBITOR5 (API5), which encodes a putative homolog of antiapoptosis protein Api5 in animals, results in delayed degeneration of the tapetum due to inhibition of the tapetal PCD process leading to defects in formation of male gametophytes. Os API5 is a nuclear protein that interacts with two DEAD-box ATP-dependent RNA helicases, API5-INTERACTING PROTEIN1 (AIP1) and AIP2. AIP1 and AIP2 are homologs of yeast (Saccharomyces cerevisiae) Suppressor of Bad Response to Refrigeration1 protein 2 (SUB2p) that have critical roles in transcription elongation and pre-mRNA splicing. Os AIP1 and AIP2 can form dimers and interact directly with the promoter region of CP1, a rice cysteine protease gene. Suppression of Os AIP1/2 leads to down-regulation of CP1, resulting in sterility, which is highly similar to the effects of suppressed expression of Os CP1. Our results uncover a previously unknown pathway for regulating PCD during tapetum degeneration in rice, one that may be conserved among eukaryotic organisms.
OSU‐DY7, a novel D‐tyrosinol derivative, mediates cytotoxicity in chronic lymphocytic leukaemia and Burkitt lymphoma through p38 mitogen‐activated protein kinase pathway
Authors: Bai Li‐Yuan , Ma Yihui , Kulp Samuel K. , Wang Shu‐Huei , Chiu Chang‐Fang , Frissora Frank , Mani Rajeswaran , Mo Xiaokui , Jarjoura David , Byrd John C. , Chen Ching‐Shih , Muthusamy Natarajan 
Published: April 2011

SummaryDrug resistance and associated immune deregulation limit use of current therapies in chronic lymphocytic leukaemia (CLL), thus warranting alternative therapy development. Herein we demonstrate that OSU‐DY7, a novel D‐tyrosinol derivative targeting p38 mitogen‐activated protein kinase (MAPK), mediates cytotoxicity in lymphocytic cell lines representing CLL (MEC‐1), acute lymphoblastic leukaemia (697 cells), Burkitt lymphoma (Raji and Ramos) and primary B cells from CLL patients in a dose‐ and time‐dependent manner. The OSU‐DY7‐induced cytotoxicity is dependent on caspase activation, as evidenced by induction of caspase‐3 activation and poly (ADP‐ribose) polymerase (PARP) cleavage and rescue of cytotoxicity by Z‐VAD‐FMK. Interestingly, OSU‐DY7‐induced cytotoxicity is mediated through activation of p38 MAPK, as evidenced by increased phosphorylation of p38 MAPK and downstream target protein MAPKAPK2. Pretreatment of B‐CLL cells with SB202190, a specific p38 MAPK inhibitor, results in decreased MAPKAPK2 protein level with concomitant rescue of the cells from OSU‐DY7‐mediated cytotoxicity. Furthermore, OSU‐DY7‐induced cytotoxicity is associated with down regulation of p38 MAPK target BIRC5, that is rescued at protein and mRNA levels by SB202190. This study provides evidence for a role of OSU‐DY7 in p38 MAPK activation and BIRC5 down regulation associated with apoptosis in B lymphocytic cells, thus warranting development of this alternative therapy for lymphoid malignancies.
Single‐dose pharmacokinetics of ceftazidime and fluconazole during concurrent clinical use in cold‐stunned Kemp’s ridley turtles (Lepidochelys kempii)
Authors: INNIS C. J. , CERESIA M. L. , MERIGO C. , SCOTT WEBER E. , PAPICH M. G. 
Published: April 2011

Innis, C. J., Ceresia, M. L., Merigo, C., Scott Weber III, E., Papich, M. G. Single‐dose pharmacokinetics of ceftazidime and fluconazole during concurrent clinical use in cold‐stunned Kemp’s ridley turtles (Lepidochelys kempii). J. vet. Pharmacol. Therap. 35, 82–89.Single‐dose pharmacokinetics of intramuscularly administered ceftazidime (22 mg/kg) and subcutaneously administered fluconazole (21 mg/kg) were investigated during concurrent clinical use in naturally cold‐stunned Kemp’s ridley turtles (Lepidochelys kempii). Maximum mean concentration for ceftazidime was 61.31 μg/mL, and time of maximum concentration was 1.56 h postinjection. Maximum mean concentration for fluconazole was 26.16 μg/mL, and time of maximum concentration was 0.79 h postinjection. Results indicate that the ceftazidime dose and dosing interval used in this study are likely to be effective in treating susceptible strains of bacteria in Kemp’s ridley turtles. However, the fluconazole dose and dosing interval are not likely to be effective against filamentous fungal pathogens that are often involved in marine turtle fungal infections.
Nucleus‐ and nucleomorph‐targeted histone proteins in a chlorarachniophyte alga
Authors: Hirakawa Yoshihisa , Burki Fabien , Keeling Patrick J. 
Published: April 2011

SummaryThe plastid of chlorarachniophytes is distinguished by the retention of a relict nucleus (nucleomorph) derived from a green algal endosymbiont, which is located in the periplastidal compartment (PPC). The nucleomorph genome of a chlorarachniophyte, Bigelowiella natans, encodes several plastid‐targeted proteins and hundreds of housekeeping proteins, but it lacks many fundamental genes to maintain itself. Here we report the first two host nucleus‐encoded genes for proteins targeted to the nucleomorph, histone H2A and H2B. We identified 20 histone genes from the host nuclear genome, and based on phylogenetic analyses predicted that most of these are derived from the host, but that two histone genes are symbiont‐derived. The genes both encode N‐terminal extensions resembling PPC targeting signals, further suggesting they function in the nucleomorph. Using green fluorescent protein (GFP) fusion proteins expressed in transformed cells, we confirmed that the putative symbiont H2A and H2B were targeted into the nucleomorph, whereas putative host proteins were localized to the host nucleus. Furthermore, we have developed a method to temporarily synchronize B. natans cells, and confirmed that both host and symbiont histone expression is controlled during the cell cycle. Our findings provide the first evidence of how the nucleomorph may be regulated by host‐encoded gene products.
The association between neighbourhoods and adverse birth outcomes: a systematic review and meta‐analysis of multi‐level studies
Authors: Metcalfe Amy , Lail Parabhdeep , Ghali William A. , Sauve Reg S. 
Published: April 2011

SummaryMetcalfe A, Lail P, Ghali WA, Sauve RS. The association between neighbourhoods and adverse birth outcomes: a systematic review and meta‐analysis of multi‐level studies. Paediatric and Perinatal Epidemiology 2011; 25: 236–245.Many studies have examined the role of neighbourhood environment on birth outcomes but, because of differences in study design and modelling techniques, have found conflicting results. Seven databases were searched (1900–2010) for multi‐level observational studies related to neighbourhood and pregnancy/birth. We identified 1502 articles of which 28 met all inclusion criteria. Meta‐analysis was used to examine the association between neighbourhood income and low birthweight. Most studies showed a significant association between neighbourhood factors and birth outcomes. A significant pooled association was found for the relationship between neighbourhood income and low birthweight [odds ratio = 1.11, 95% confidence interval: 1.02, 1.20] whereby women who lived in low income neighbourhoods had significantly higher odds of having a low birthweight infant. This body of literature was found to consistently document significant associations between neighbourhood factors and birth outcomes. The consistency of findings from observational studies in this area indicates a need for causal studies to determine the mechanisms by which neighbourhoods influence birth outcomes.
A simple detached leaf assay provides rapid and inexpensive determination of pathogenicity of Pythium isolates to ‘all year round’ (AYR) chrysanthemum roots
Authors: Pettitt T. R. , Wainwright M. F. , Wakeham A. J. , White J. G. 
Published: April 2011

A detached leaf assay was developed to determine the pathogenicity of Pythium isolates to cut‐flower chrysanthemum roots. Leaves from young plants were excised and inoculated by insertion of a plug of mycelium into a slit cut in the excised petiole. After incubation leaves were assessed for presence and extent of necrosis. Necrosis indicated pathogenicity and was consistently confirmed by comparisons with whole plant inoculations. The rate of necrosis spread also gave some indication of virulence. Isolates of Pythium sylvaticum, P. ultimum and HS group were the most virulent, with a mean rate of spread of 14·6 mm per day, significantly (P < 0·05) faster than the mean rate of spread, 1·6 mm per day, of less virulent isolates. Less virulent isolates included P. irregulare, P. oligandrum and P. aphanidermatum. The latter was unexpected, as P. aphanidermatum is an important species in pythium root rot epidemics in chrysanthemums elsewhere. The value of the detached leaf assay for screening large numbers of isolates was demonstrated in a survey of isolates from clinic samples from chrysanthemum nurseries and in a series of dilution‐plating experiments looking at numbers of Pythium propagules in commercial chrysanthemum beds showing root rot. In the survey, the predominant pathogenic species was identified as P. sylvaticum and the most likely source of infection was contaminated soil as opposed to blocking media or irrigation water, whilst in soil colonization studies the use of detached leaf assays demonstrated a relationship between pathogenic inoculum concentration in soil and the expression of root rot symptoms.
Control of root hair development in Arabidopsis thaliana by an endoplasmic reticulum anchored member of the R2R3‐MYB transcription factor family
Authors: Slabaugh Erin , Held Michael , Brandizzi Federica 
Published: April 2011

SummaryThe evolution of roots and root hairs was a crucial innovation that contributed to the adaptation of plants to a terrestrial environment. Initiation of root hairs involves transcriptional cues that in part determine cell patterning of the root epidermis. Once root hair initiation has occurred, elongation of the root hair takes place. Although many genes have been identified as being involved in root hair development, many contributors remain uncharacterized. In this study we report on the involvement of a member (here dubbed maMYB) of the plant‐specific R2R3‐MYB family of transcription factors in root hair elongation in Arabidopsis. We show that maMYB is associated with the endoplasmic reticulum membrane with the transcription factor domain exposed to the cytosol, suggesting that it may function as a membrane‐tethered transcription factor. We demonstrate that a truncated form of maMYB (maMYB84–309), which contains the R2R3‐MYB transcription factor domain, is localized and retained in the nucleus, where it regulates gene expression. Silencing of maMyb resulted in plants with significantly shorter root hairs but similar root hair density compared with wild type, implying a role of the protein in root hair elongation. 2,4‐D (2,4‐dichlorophenoxyacetic acid), an exogenous auxin analog that promotes root hair elongation, rescued the short root hair phenotype and maMyb mRNA was induced in the presence of 2,4‐D and IAA (indole‐3‐acetic acid). These results indicate a functional role of maMYB, which is integrated with auxin, in root hair elongation in Arabidopsis.
Unexplained polyposis: a challenge for geneticists, pathologists and gastroenterologists
Authors: Mongin C , Coulet F , Lefevre JH , Colas C , Svrcek M , Eyries M , Lahely Y , Fléjou J‐F , Soubrier F , Parc Y 
Published: April 2011

Mongin C, Coulet F, Lefevre JH, Colas C, Svrcek M, Eyries M, Lahely Y, Fléjou J‐F, Soubrier F, Parc Y. Unexplained polyposis: a challenge for geneticists, pathologists and gastroenterologists.Two main colorectal polyposis syndromes have been described, familial adenomatous polyposis and MUTYH‐associated polyposis syndromes. Some polyposis remains unexplained: 20% of adenomatous polyposis and serrated polyposis. The aim of this study was to evaluate in a cohort of patients with unexplained polyposis whether a genetic defect could be detected. Individuals presenting polyposis with more than 40 adenomas or more than 20 serrated polyps (hyperplastic, sessile serrated and mixed), without causative mutation identified, were included. Complementary explorations on APC or MUTYH were performed: search for APC mosaicism, splicing‐affecting mutations, large genomic rearrangement of MUTYH. Four genes of Wnt pathway (AXIN2, PPP2R1B, WIF1, SFRP1) and two genes of transforming growth factor‐β (TGF‐β) pathway (SMAD4, BMPR1A) were screened for germline mutation. Twenty‐five patients had an unexplained adenomatous polyposis (familial or sporadic). Five pathogenic mutations were found: four in APC gene (with one case of mosaicism) and one in BMPR1A gene. The exploration of APC mosaicism was better performed from adenoma DNA with high‐resolution melting. The screening of the candidate genes did not find any causative mutation. Thirteen individuals had an unexplained serrated polyposis and a frameshift on SMAD4 gene was identified. All mutations were identified in familial cases of polyposis. After new pathological examination, both BMPR1A and SMAD4 cases were found to be associated with a juvenile polyposis while the polyposis was initially described as adenomatous or undetermined. In 17% (6/38) of the patients the causative mutation of the polyposis was identified. Genetic causes were heterogeneous. Sporadic polyposis patients must be considered as potential APC mosaicism. The histological classification of polyposis is strongly important in direct genetic exploration.
Thoracic complications following lung transplantation: 64‐MDCT findings
Authors: Caruso Settimo , Crino’ Francesca , Milazzo Mariapina , Vitulo Patrizio , Bertani Alessandro , Marrone Gianluca , Mamone Giuseppe , Maruzzelli Luigi , Miraglia Roberto , Carollo Vincenzo , Luca Angelo , Gridelli Bruno 
Published: April 2011

Caruso S, Crino’ F, Milazzo M, Vitulo P, Bertani A, Marrone G, Mamone G, Maruzzelli L, Miraglia R, Carollo V, Luca A, Gridelli B. Thoracic complications following lung transplantation: 64‐MDCT findings. Clin Transplant 2011: 25: 673–684. © 2011 John Wiley & Sons A/S.Abstract:  The aim of this review is to present the wide spectrum of common and uncommon thoracic complications that can affect the lung after transplantation. These complications were analyzed using 64 multi‐detector row helical CT (MDCT). Sixty‐four MDCT techniques and parameters are illustrated. Correlations of imaging findings and pathologic and histologic specimens obtained by transbronchial biopsy and broncoalveolar lavage are illustrated in representative cases.
Sexual Conflict Over Spermatophore Attachment in a Nuptially Feeding Cricket
Authors: Prokop Pavol , Maxwell Michael R. 
Published: April 2011

AbstractSexual conflict is implicated in the evolution of nuptial feeding. One function of nuptial gifts lies in mating effort, where the female’s eating of the gift reduces her likelihood of prematurely terminating sperm transfer. We test several ideas regarding sexual conflict in the nuptially feeding wood cricket Nemobius sylvestris. In this cricket, males pass two kinds of spermatophores to females: spermless microspermatophores and larger sperm‐filled macrospermatophores. Females may palpate the males’ forewing secretions as a possible additional form of nuptial feeding. We manipulated male mobility and female feeding regime to examine the effects on spermatophore transfer, macrospermatophore attachment duration, and palpations of the males’ forewings. Neither male confinement nor female feeding regime affected the occurrence of macrospermatophore transfer. Males transferred the macrospermatophore sooner to low‐food females than to high‐food females. Males that were freely mobile (unconfined and sham treatments) had longer macrospermatophore attachment durations than confined males, while female feeding regime did not affect attachment duration. The overall occurrence of female palpation was not significantly affected by female feeding regime. However, high‐food females were more likely to perform short palpations before microspermatophore transfer, while low‐food females were more likely to palpate after macrospermatophore transfer. Sexual conflict is evident in that males appear to guard against premature removal of the sperm‐filled macrospermatophore. Low‐food females appear to facilitate the early transfer of the macrospermatophore, while being more likely to perform relatively long post‐insemination palpations than better‐fed females.
Update in paediatric asthma management: Where is evidence challenging current practice?
Authors: Robinson Paul D , Van Asperen Peter 
Published: April 2011

AbstractExtrapolation of management strategies based on results from predominantly adult asthma studies frequently occurs in paediatric asthma despite increasing evidence that paediatric asthma and, in particular, pre‐school recurrent wheeze are very different disease entities. Response to medications in paediatric subjects is often different from that seen in their older adolescent and adult counterparts. In this update, we discussed recent studies that have had important implications for future paediatric asthma management. The overuse of combination inhaled steroid and long‐acting beta2 agonist inhalers in paediatric asthma despite ongoing safety concerns is an increasing trend in paediatric asthma, and recent evidence has helped clarify how they should be used in children. Other aspects discussed include the role of oral corticosteroids in pre‐school viral‐induced wheeze and the utility of leukotriene receptor antagonists in exercise‐induced asthma.
Sleep quality of Chinese adolescents: Distribution and its associated factors
Authors: Xu Zhiwei , Su Hong , Zou Yanfeng , Chen Juan , Wu Jialing , Chang Weiwei 
Published: April 2011

Aim:  To investigate the sleep quality status and its associated factors (including psychological and physiological as well as social demographic factors) among Chinese mainland adolescents.Methods:  Ten schools, including junior schools, senior schools and universities of Hefei (the capital of Anhui Province in China), were randomly selected. By using the Pittsburgh Sleep Quality Index, Self‐Rated Health Measurement Scale Version 1.0, University of California, Los Angeles, Loneliness Scale, Beck Depression Inventory, Self‐rating Anxiety Scale and a demographic survey, a cross‐sectional study was implemented to 5226 students of the selected schools to investigate the adolescents' sleep quality, self‐rated health, psychological status and demographic variables.Results:  There were significant sleep quality differences between different groups of grade level, residence, family type, self‐report personality, self‐report examination scores, self‐rated health, depression, loneliness and anxiety according to the results of the univariate analysis (P < 0.01 or <0.05). The multivariate analysis indicated that high grade level (OR = 1.490, 95%CI = 1.350–1.645), living in rural areas (OR = 0.874, 95%CI = 0.799–0.956), poor self‐rated health (OR = 0.934, 95%CI = 0.926–0.942), high degree of depression (OR = 1.867, 95%CI = 1.514–2.302) and anxiety (OR = 1.976, 95%CI = 1.647–2.372) may be the influencing factors of poor sleep.Conclusions:  The poor sleep quality of many adolescents may be attributed to various causes, especially psychological reasons.
Cochlear function in 1‐year‐old term infants born with hypoxia‐ischaemia or low Apgar scores
Authors: Jiang Ze D , Zang Zeng , Wilkinson Andrew R 
Published: April 2011

Aim:  To examine the influence of perinatal hypoxia‐ischaemia (HI) or low Apgar scores on distortion product otoacoustic emissions (DPOAEs) in infants at 1 year and detect any postnatal changes.Methods:  Eighty‐eight term infants born with perinatal HI or low Apgar scores alone were recruited at 1 year of age. The ears with type A tympanogram (normal) were studied with DPOAEs at 10 frequencies between 0.5 kHz and 10 kHz.Results:  DPOAE pass rates were decreased at all frequencies 1–10 kHz, particularly 1 and 2 kHz in both infants born with HI and those with low Apgar scores (χ2= 3.80–15.09, P < 0.05–0.01). Overall pass rates in the two groups were also decreased (X2= 10.78 and 12.12, P < 0.01 and 0.01). No marked differences were found between infants born with HI and those with low Apgar score. Compared with those recorded at 1 and 6 months, DPOAE pass rates at 1 year were increased slightly in infants born with HI, but showed no marked changes in those born with low Apgar scores.Conclusions:  DPOAE pass rates, mainly at 1 and 2 kHz, were decreased at 1 year in infants born with perinatal HI and low Apgar scores, suggesting a relative poor cochlear function. Further studies are needed to ascertain the hearing acuity.