bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic and histological studies on the delayed systemic movement of Tobacco Mosaic Virus in Arabidopsis thaliana
Authors: Serrano Carolina , González-Cruz Javiera , Jauregui Francisca , Medina Consuelo , Mancilla Pablo , Matus José Tomás , Arce-Johnson Patricio 
Published: September 2008

Abstract

Background
Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1). The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes.
We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied.

Results
TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi) in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1), is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology.

Conclusion
The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype.
Hfq regulates the expression of the thermostable direct hemolysin gene in Vibrio parahaemolyticus
Authors: Nakano Masayuki , Takahashi Akira , Su Zehong , Harada Nagakatsu , Mawatari Kazuaki , Nakaya Yutaka 
Published: September 2008

Abstract

Background
The hfq gene is conserved in a wide variety of bacteria and Hfq is involved in many cellular functions such as stress responses and the regulation of gene expression. It has also been reported that Hfq is involved in bacterial pathogenicity. However, it is not clear whether Hfq regulates virulence in Vibrio parahaemolyticus. To evaluate this, we investigated the effect of Hfq on the expression of virulence-associated genes including thermostable direct hemolysin (TDH), which is considered to be an important virulence factor in V. parahaemolyticus, using an hfq deletion mutant.

Results
The production of TDH in the hfq deletion mutant was much higher than in the parental strain. Quantification of tdh promoter activity and mRNA demonstrated that transcription of the tdh gene was up-regulated in the mutant strain. The hfq-complemented strain had a normal (parental) amount of tdh expression. The transcriptional activity of tdhA was particularly increased in the mutant strain. These results indicate that Hfq is closely associated with the expression level of the tdh gene. Interestingly, other genes involved in the pathogenicity of V. parahaemolyticus, such as VP1680, vopC, and vopT, were also up-regulated in the mutant strain.

Conclusion
Hfq regulates the expression of virulence-associated factors such as TDH and may be involved in the pathogenicity of V. parahaemolyticus.
RETRACTED ARTICLE: Differential regulation of wild-type and mutant alpha-synuclein binding to synaptic membranes by cytosolic factors
Authors: Wislet-Gendebien Sabine , Visanji Naomi P , Whitehead Shawn N , Marsilio Diana , Hou Weimin , Figeys Daniel , Fraser Paul E , Bennett Steffany AL , Tandon Anurag 
Published: September 2008

Abstract

Background
Alpha-Synuclein (α-syn), a 140 amino acid protein associated with presynaptic membranes in brain, is a major constituent of Lewy bodies in Parkinson's disease (PD). Three missense mutations (A30P, A53T and E46K) in the α-syn gene are associated with rare autosomal dominant forms of familial PD. However, the regulation of α-syn's cellular localization in neurons and the effects of the PD-linked mutations are poorly understood.

Results
In the present study, we analysed the ability of cytosolic factors to regulate α-syn binding to synaptic membranes. We show that co-incubation with brain cytosol significantly increases the membrane binding of normal and PD-linked mutant α-syn. To characterize cytosolic factor(s) that modulate α-syn binding properties, we investigated the ability of proteins, lipids, ATP and calcium to modulate α-syn membrane interactions. We report that lipids and ATP are two of the principal cytosolic components that modulate Wt and A53T α-syn binding to the synaptic membrane. We further show that 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16:0 PAF) is one of the principal lipids found in complex with cytosolic proteins and is required to enhance α-syn interaction with synaptic membrane. In addition, the impaired membrane binding observed for A30P α-syn was significantly mitigated by the presence of protease-sensitive factors in brain cytosol.

Conclusion
These findings suggest that endogenous brain cytosolic factors regulate Wt and mutant α-syn membrane binding, and could represent potential targets to influence α-syn solubility in brain.
The clinical overlap between functional dyspepsia and irritable bowel syndrome based on Rome III criteria
Authors: WANG AnJiang , LIAO XianHua , XIONG LiShou , PENG Sui , XIAO YingLian , LIU SiChun , HU PinJin , CHEN MinHu 
Published: September 2008

Abstract

Background
Epidemiological studies suggest considerable overlap between functional dyspepsia (FD) and irritable bowel syndrome (IBS). To date, no surveys have been performed to investigate the clinical overlap between these two disorders using Rome III criteria. Our aim was to investigate the prevalence and risk factors for the overlap of FD and IBS based on Rome III criteria in a large clinical sample.

Methods
Consecutive patients at the general gastroenterology outpatient clinic were requested to complete a self-report questionnaire. FD and IBS were defined by Rome III criteria.

Results
Questionnaires were returned by 3014 patients (52.8% female, 89% response rate). FD-IBS overlap was observed in 5.0% of the patients, while 15.2% and 10.9% of the patients were classified as FD alone and IBS alone, respectively. Compared with non-IBS patients, the odds ratio of having FD among IBS patients was 2.09 (95% CI: 1.68–2.59). Patients with FD-IBS overlap had higher severity scores for the postprandial fullness symptom (2.35 ± 1.49 vs. 1.72 ± 1.59, P < 0.001) and overall FD symptom (6.65 ± 2.88 vs. 5.82 ± 2.76, P = 0.002) than those with FD alone. The only independent risk factor for FD-IBS overlap vs. FD alone was the presence of postprandial fullness symptom (OR 2.67, 95% CI: 1.34–5.31).

Conclusion
Clinical overlap of FD and IBS according to Rome III criteria is very common. One risk factor for FD-IBS overlap is the presence of postprandial fullness symptom. This study provides clues for future pathophysiological studies of FD and IBS.
'Fat mass and obesity associated' gene (FTO): No significant association of variant rs9939609 with weight loss in a lifestyle intervention and lipid metabolism markers in German obese children and adolescents
Authors: Müller Timo D , Hinney Anke , Scherag André , Nguyen Thuy T , Schreiner Felix , Schäfer Helmut , Hebebrand Johannes , Roth Christian L , Reinehr Thomas 
Published: September 2008

Abstract

Background
We have previously identified strong association of six single nucleotide polymorphisms (SNPs) in FTO (fat mass and obesity associated gene) to early onset extreme obesity within the first genome wide association study (GWA) for this phenotype. The aim of this study was to investigate whether the obesity risk allele of one of these SNPs (rs9939609) is associated with weight loss in a lifestyle intervention program. Additionally, we tested for association of rs9939609 alleles with fasting blood parameters indicative of glucose and lipid metabolism.

Methods
We initially analysed rs9939609 in a case-control study comprising 519 German overweight and obese children and adolescents and 178 normal weight adults. In 207 of the obese individuals who took part in the outpatient obesity intervention program 'Obeldicks' we further analysed whether carrier status of the obesity risk A-allele of rs9939609 has a differential influence on weight loss after the intervention program. Additionally, we investigated in 480 of the overweight and obese patients whether rs9939609 is associated with fasting blood levels of glucose, triglycerides and HDL and LDL-cholesterol. Genotyping was performed using allele specific polymerase chain reaction (ARMS-PCR). For the association study (case-control approach), the Cochran-Armitage trend test was applied. Blood parameters were analysed using commercially available test kits and the log10-transformed blood parameters and changes in BMI-standard deviation scores (BMI-SDS) were analysed by linear regression with sex and age as covariates under an additive mode of inheritance with the rs9939609 A-allele as risk allele.

Results
We confirmed the association of the risk A-allele of rs9939609 with overweight and early onset obesity (one sided p = 0.036). However, we observed no association of rs9939609 alleles with weight loss or fasting levels of blood glucose, triglycerides and cholesterol.

Conclusion
We confirmed the rs9939609 A-allele as a risk factor for early onset obesity whereas its impact on weight loss or on serum levels of glucose, triglycerides and cholesterol could not be detected in our samples.

Trial Registration

This study is registered at clinicaltrials.gov (NCT00435734).
Protective effect of KCNH2 single nucleotide polymorphism K897T in LQTS families and identification of novel KCNQ1 and KCNH2mutations
Authors: Zhang Xianqin , Chen Shenghan , Zhang Li , Liu Mugen , Redfearn Sharon , Bryant Randall M , Oberti Carlos , Vincent G Michael , Wang Qing K 
Published: September 2008

Abstract

Background

KCNQ1 and KCNH2 are the two most common potassium channel genes causing long QT syndrome (LQTS), an inherited cardiac arrhythmia featured by QT prolongation and increased risks of developing torsade de pointes and sudden death. To investigate the disease expressivity, this study aimed to identify mutations and common variants that can modify LQTS phenotype.

Methods
In this study, a cohort of 112 LQTS families were investigated. Among them two large LQTS families linkage analysis with markers spanning known LQTS genes was carried out to identify the specific gene for mutational analysis. All exons and exon-intron boundaries of KCNH2 and KCNQ1 were sequenced for mutational analysis.

Results
LQTS-associated mutations were identified in eight of 112 families. Two novel mutations, L187P in KCNQ1 and 2020insAG in KCNH2, were identified. Furthermore, in another LQTS family we found that KCNH2 mutation A490T co-segregated with a common SNP K897T in KCNH2. KCNH2 SNP K897T was reported to exert a modifying effect on QTc, but it remains controversial whether it confers a risk or protective effect. Notably, we have found that SNP K897T interacts with mutation A490T in cis orientation. Seven carriers for A490T and the minor allele T of SNP K897T showed shorter QTc and fewer symptoms than carriers with A490T or A490P (P < 0.0001).

Conclusion
Our family-based approach provides support that KCNH2 SNP K897T confers a protective effect on LQTS patients. Our study is the first to investigate the effect of SNP K897T on another KCNH2 mutation located in cis orientation. Together, our results expand the mutational and clinical spectrum of LQTS and provide insights into the factors that determine QT prolongation associated with increased risk of ventricular tachycardia and sudden death.
Keratin 8 expression in head and neck epithelia
Authors: Matthias Christoph , Mack Brigitte , Berghaus Alexander , Gires Olivier 
Published: September 2008

Abstract

Background
The intermediate filament forming protein keratin 8 (K8) is a tumour-associated antigen, which was shown to be over-expressed in a variety of malignancies. Here, we present a study of K8 expression in squamous epithelia of the head and neck area, including normal mucosa, hyperplastic and dysplastic leukoplakia, carcinomas of different sub-localisations, and lymph node metastases.

Methods
K8 expression was assessed upon immunohistochemistry with specific antibodies in cryosections of primary tumours of the head and neck area.

Results
K8 expression was characteristic of transformed tissue and marked early stages of disease, i.e. dysplastic oral leukoplakia, but not normal or hyperplastic epithelium. With the exception of carcinomas of the larynx and the tongue, K8 expression also strictly differentiated carcinomas from normal epithelium of the same origin. Furthermore, K8high was characteristic of cells, which had detached from the sites of primary tumours and had been invading the surrounding tissue at the time point of surgery.

Conclusion
K8 is an excellent marker for head and neck malignancies, which allows for early detection as well as for visualisation of potentially disseminating tumour cells in vivo.
Secular changes in height, weight and body mass index in Hong Kong Children
Authors: So Hung-Kwan , Nelson Edmund AS , Li Albert M , Wong Eric MC , Lau Joseph TF , Guldan Georgia S , Mak Kwok-Hang , Wang Youfa , Fok Tai-Fai , Sung Rita YT 
Published: September 2008

Abstract

Background
Large population growth surveys of children and adolescents aged 6 to 18 y were undertaken in Hong Kong in 1963 and 1993. The global epidemic of obesity is a major public health concern. To monitor the impact of this epidemic in Hong Kong children and to identify secular changes in growth, a further growth survey was undertaken in 2005/6.

Methods
Cross-sectional height and weight measurements of 14,842 children and adolescents aged 6 to 18 y from Hong Kong's 18 districts were obtained during the 2005/6 school year. Percentile curves were constructed using LMS method and sex-specific percentile values of weight-for-age, height-for-age, and BMI-for-age were compared with those data from 1963 and 1993.

Results
Secular changes in height, weight and BMI were noted between 1963 and 1993 and between 1993 and 2005/6. In the latter period, greater changes were observed at younger ages, and particularly in boys. On an annual basis, the 1993–2005/6 changes were less than those during 1963–1993. Using the International Obesity Task Force cut-offs, 16.7% of children were overweight or obese in 2005/6, which was a 5.1% increase since 1993.

Conclusion
These data provide policy-makers with further evidence of the secular changes in child growth and the increasing obesity epidemic among Hong Kong children.
Low wintertime vitamin D levels in a sample of healthy young adults of diverse ancestry living in the Toronto area: associations with vitamin D intake and skin pigmentation
Authors: Gozdzik Agnes , Barta Jodi Lynn , Wu Hongyu , Wagner Dennis , Cole David E , Vieth Reinhold , Whiting Susan , Parra Esteban J 
Published: September 2008

Abstract

Background
Vitamin D plays a critical role in bone metabolism and many cellular and immunological processes. Recent research indicates that concentrations of serum 25-hydroxyvitamin D [25(OH)D], the main indicator of vitamin D status, should be in excess of 75 nmol/L. Low levels of 25(OH)D have been associated with several chronic and infectious diseases. Previous studies have reported that many otherwise healthy adults of European ancestry living in Canada have low vitamin D concentrations during the wintertime. However, those of non-European ancestry are at a higher risk of having low vitamin D levels. The main goal of this study was to examine the vitamin D status and vitamin D intake of young Canadian adults of diverse ancestry during the winter months.

Methods
One hundred and seven (107) healthy young adults self-reporting their ancestry were recruited for this study. Each participant was tested for serum 25(OH)D concentrations and related biochemistry, skin pigmentation indices and basic anthropometric measures. A seven-day food diary was used to assess their vitamin D intake. An ANOVA was used to test for significant differences in the variables among groups of different ancestry. Linear regression was employed to assess the impact of relevant variables on serum 25(OH)D concentrations.

Results
More than 93% of the total sample had concentrations below 75 nmol/L. Almost three-quarters of the subjects had concentrations below 50 nmol/L. There were significant differences in serum 25(OH)D levels (p < 0.001) and vitamin D intake (p = 0.034) between population groups. Only the European group had a mean vitamin D intake exceeding the current Recommended Adequate Intake (RAI = 200 IU/day). Total vitamin D intake (from diet and supplements) was significantly associated with 25(OH)D levels (p < 0.001). Skin pigmentation, assessed by measuring skin melanin content, showed an inverse relationship with serum 25(OH)D (p = 0.033).

Conclusion
We observe that low vitamin D levels are more prevalent in our sample of young healthy adults than previously reported, particularly amongst those of non-European ancestry. Major factors influencing 25(OH)D levels were vitamin D intake and skin pigmentation. These data suggest a need to increase vitamin D intake either through improved fortification and/or supplementation.
RASSF1A protein expression and correlation with clinicopathological parameters in renal cell carcinoma
Authors: Tezval Hossein , Merseburger Axel S , Matuschek Ira , Machtens Stefan , Kuczyk Markus A , Serth Jürgen 
Published: September 2008

AbstractBackgroundEpigenetic silencing of RAS association family 1A (RASSF1A) tumor suppressor gene occurs in various histological subtypes of renal cell carcinoma (RCC) but RASSF1A protein expression in clear cell RCC as well as a possible correlation with clinicopathological parameters of patients has not been analyzed at yet.Methods318 primary clear cell carcinomas were analyzed using tissue microarray analysis and immunohistochemistry. Survival analysis was carried out for 187 patients considering a follow-up period of 2–240 month.ResultsExpression of RASSF1A was found to be significantly decreased in tumoral cells when compared to normal tubular epithelial cells. RASSF1A immunopositivity was significantly associated with pT stage, group stage and histological grade of tumors and showed a tendency for impaired survival in Kaplan-Meier analysis.ConclusionWhile most tumors demonstrate a loss of RASSF1A protein, a subset of tumors was identified to exhibit substantial RASSF1A protein expression and show increased tumor progression. Thus RCC tumorigenesis without depletion of RASSF1A may be associated with an adverse clinical outcome.
beta-estradiol attenuates the anti-HIV-1 efficacy of Stavudine (D4T) in primary PBL
Authors: Zhang Mingjie , Huang Qingsheng , Huang Yong , Wood Owen , Yuan Weishi , Chancey Caren , Daniel Sylvester , Rios Maria , Hewlett Indira , Clouse Kathleen A , Dayton Andrew I 
Published: September 2008

Abstract

Background
Female hormones are known to play an important role in predisposition for many infectious diseases. Recent work suggests there are gender effects in HIV/AIDS progression. Here we ask whether the sex steroid hormone β-estradiol affects the replication of HIV-1 or the efficacy of a common anti-retroviral drug, Stavudine (D4T).

Results
Human PBL were infected with HIV-1 in the presence or absence of combinations of sex steroid hormones and the anti-retroviral drug, D4T. After seven days in culture, viral supernatants were assayed for HIV-1 p24 protein. β-estradiol resulted in a modest inhibition of HIV-1 replication of ~26%. However, 2 nM β-estradiol increased the amount of HIV-1 replication in the presence of 50 nM D4T from a baseline of 33% (+/- SE = 5.4) to 74% (+/- SE = 5.4) of control virus levels in the absence of drug. Both results were statistically highly significant (p < 0.001). β-estradiol did not increase the replication of a D4T-resistant strain of HIV in the presence of D4T. The effects were unlikely to be due to general cell inhibition or toxicity because these concentrations of drug and hormone cause no cytotoxicity in PBL as measured by trypan blue exclusion.

Conclusion
β-estradiol inhibited both HIV-1 replication in primary human PBL and the antiretroviral efficacy of D4T in PBL cultures. To optimize antiretroviral drug therapy, it may be necessary to monitor patient hormonal status.
Homonuclear 1H NMR and circular dichroism study of the HIV-1 Tat Eli variant
Authors: Watkins Jennifer D , Campbell Grant R , Halimi Hubert , Loret Erwann P 
Published: September 2008

Abstract

Background
The HIV-1 Tat protein is a promising target to develop AIDS therapies, particularly vaccines, due to its extracellular role that protects HIV-1-infected cells from the immune system. Tat exists in two different lengths, 86 or 87 residues and 99 or 101 residues, with the long form being predominant in clinical isolates. We report here a structural study of the 99 residue Tat Eli variant using 2D liquid-state NMR, molecular modeling and circular dichroism.

Results
Tat Eli was obtained from solid-phase peptide synthesis and the purified protein was proven biologically active in a trans-activation assay. Circular dichroism spectra at different temperatures up to 70°C showed that Tat Eli is not a random coil at 20°C. Homonuclear 1H NMR spectra allowed us to identify 1639 NMR distance constraints out of which 264 were interresidual. Molecular modeling satisfying at least 1474 NMR constraints revealed the same folding for different model structures. The Tat Eli model has a core region composed of a part of the N-terminus including the highly conserved Trp 11. The extra residues in the Tat Eli C-terminus protrude from a groove between the basic region and the cysteine-rich region and are well exposed to the solvent.

Conclusion
We show that active Tat variants share a similar folding pattern whatever their size, but mutations induce local structural changes.