138 research outputs found

    Molecular lens applied to benzene and carbon disulfide molecular beams

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    A molecular lens of the nonresonant dipole force formed by focusing a nanosecond IR laser pulse has been applied to benzene and CS2 molecular beams. Using the velocity map imaging technique for molecular ray tracing, characteristic molecular lens parameters including the focal length (f ), minimum beam width (W), and distance to the minimum beam width position (D) were determined. The laser intensity dependence of the observed lens parameters was in good agreement with theoretical predictions. W was independent of the laser peak intensity (I-0), whereas f and D varied linearly with 1/I-0. The differences in lens parameters between the molecular species were well correlated with the polarizability per mass values of the molecules. A high chromatographic resolution of Rs = 0.84 was achieved between the images of benzene molecular beams undeflected and deflected by the lens. The possibilities for a new type of chromatography are discussed.open293

    Frequency and predictors of miliary tuberculosis in patients with miliary pulmonary nodules in South Korea: A retrospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Miliary pulmonary nodules are commonly caused by various infections and cancers. We sought to identify the relative frequencies of various aetiologies and the clinical and radiographic predictors of miliary tuberculosis (TB) in patients with miliary pulmonary nodules.</p> <p>Methods</p> <p>We performed a retrospective cohort study of patients who presented with micronodules occupying more than two-thirds of the lung volume, based on computed tomography (CT) of the chest, between November 2001 and April 2007, in a tertiary referral hospital in South Korea.</p> <p>Results</p> <p>We analyzed 76 patients with miliary pulmonary nodules. Their median age was 52 years and 38 (50%) were males; 18 patients (24%) had a previous or current malignancy and five (7%) had a history of TB. The most common diagnoses of miliary nodules were miliary TB (41 patients, 54%) and miliary metastasis of malignancies (20 patients, 26%). Multivariate analysis revealed that age ≀30 years, HIV infection, corticosteroid use, bronchogenic spread of lesions, and ground-glass opacities occupying >25% of total lung volume increased the probability of miliary TB. However, a history of malignancy decreased the probability of miliary TB.</p> <p>Conclusion</p> <p>Miliary TB accounted for approximately half of all causes of miliary pulmonary nodules. Young age, an immune-compromised state, and several clinical and radiographic characteristics increased the probability of miliary TB.</p

    Disproportionate Alterations in the Anterior and Posterior Insular Cortices in Obsessive–Compulsive Disorder

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    Recent studies have reported that the insular cortex is involved in the pathophysiology of obsessive–compulsive disorder (OCD). However, specific morphometric abnormalities of the insular subregions remain unclear. In this study, we examined insular cortical volume to determine whether the volume of the anterior and posterior insular cortices of unmedicated OCD patients differed according to different symptom dimensions.Using magnetic resonance imaging, we measured the gray matter volumes of the insular cortex and its subregions (anterior and posterior divisions) in 41 patients with OCD (31 drug-naΓ―ve and 10 non-medicated) and 53 healthy controls. Volumetric measures of the insular cortex were compared according to different OC symptoms. Enlarged anterior and reduced posterior insular cortices were observed in OCD patients. The insular volumetric alterations were more significant in OCD patients with predominant checking rather than cleaning symptoms when compared with healthy controls.Our results suggest the presence of unbalanced anterior and posterior insular volumetric abnormalities in unmedicated OCD patients and emphasize the distinct role of the insular cortex in different OC symptoms. We propose that the insular morphometric alterations may influence the modulation of interoceptive processing, the insular functional role, in OCD patients with different symptoms

    Portuguese propolis disturbs glycolytic metabolism of human colorectal cancer in vitro

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    Propolis is a resin collected by bees from plant buds and exudates, which is further processed through the activity of bee enzymes. Propolis has been shown to possess many biological and pharmacological properties, such as antimicrobial, antioxidant, immunostimulant and antitumor activities. Due to this bioactivity profile, this resin can become an alternative, economic and safe source of natural bioactive compounds.Antitumor action has been reported in vitro and in vivo for propolis extracts or its isolated compounds; however, Portuguese propolis has been little explored. The aim of this work was to evaluate the in vitro antitumor activity of Portuguese propolis on the human colon carcinoma cell line HCT-15, assessing the effect of different fractions (hexane, chloroform and ethanol residual) of a propolis ethanol extract on cell viability, proliferation, metabolism and death. METHODS: Propolis from Angra do HeroΓ­smo (Azores) was extracted with ethanol and sequentially fractionated in solvents with increasing polarity, n-hexane and chloroform. To assess cell viability, cell proliferation and cell death, Sulforhodamine B, BrDU incorporation assay and Anexin V/Propidium iodide were used, respectively. Glycolytic metabolism was estimated using specific kits. RESULTS: All propolis samples exhibited a cytotoxic effect against tumor cells, in a dose- and time-dependent way. Chloroform fraction, the most enriched in phenolic compounds, appears to be the most active, both in terms of inhibition of viability and cell death. Data also show that this cytotoxicity involves disturbance in tumor cell glycolytic metabolism, seen by a decrease in glucose consumption and lactate production. CONCLUSION: Our results show that Portuguese propolis from Angra do HeroΓ­smo (Azores) can be a potential therapeutic agent against human colorectal cancer.We thank the Portuguese Science and Technology Foundation (FCT) for VMG fellowship (ref. SFRH/BI/33503/2008). The authors thank Mr. Antonio Marques from Frutercoop - Azores, who kindly collected and provided the propolis sample for the study

    Frequent reduced expression of alpha-1B-adrenergic receptor caused by aberrant promoter methylation in gastric cancers

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    Recent studies have suggested that epigenetic inactivation of tumour-related genes by promoter methylation participates in the development of gastric cancer. We newly identified the frequently aberrant promoter methylation of alpha-1B-adrenergic receptor (ADRA1B) in colorectal cancer by methylation-sensitive representational difference analysis (MS-RDA) and examined the methylation status of the ADRA1B promoter in 34 paired samples of colorectal cancer and surrounding epithelial tissue, and 34 paired samples of gastric cancer and surrounding epithelial tissue. In colorectal cancers, only four of 34 (11.8%) tumours showed ADRA1B promoter methylation. In contrast, ADRA1B promoter methylation was detected in 24 of 34 (70.6%) gastric cancers and in 14 of 34 (41.2%) surrounding epithelial tissues. The frequency of ADRA1B promoter methylation was higher in gastric epithelial tissues with intestinal metaplasia (41.6%) than in those without intestinal metaplasia (25.0%). Reverse transcription–PCR detected reduced ADRA1B expression in 12 of 18 (66.7%) gastric cancers, and its promoter methylation was detected in 11 of these 12 (91.7%) gastric cancers with reduced ADRA1B expression. Thus, ADRA1B promoter is frequently methylated in gastric cancer. Our results suggest that the ADRA1B gene is an important tumour-related gene frequently involved in the development and progression of gastric cancer

    Selection of Inhibitor-Resistant Viral Potassium Channels Identifies a Selectivity Filter Site that Affects Barium and Amantadine Block

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    BACKGROUND:Understanding the interactions between ion channels and blockers remains an important goal that has implications for delineating the basic mechanisms of ion channel function and for the discovery and development of ion channel directed drugs. METHODOLOGY/PRINCIPAL FINDINGS:We used genetic selection methods to probe the interaction of two ion channel blockers, barium and amantadine, with the miniature viral potassium channel Kcv. Selection for Kcv mutants that were resistant to either blocker identified a mutant bearing multiple changes that was resistant to both. Implementation of a PCR shuffling and backcrossing procedure uncovered that the blocker resistance could be attributed to a single change, T63S, at a position that is likely to form the binding site for the inner ion in the selectivity filter (site 4). A combination of electrophysiological and biochemical assays revealed a distinct difference in the ability of the mutant channel to interact with the blockers. Studies of the analogous mutation in the mammalian inward rectifier Kir2.1 show that the T-->S mutation affects barium block as well as the stability of the conductive state. Comparison of the effects of similar barium resistant mutations in Kcv and Kir2.1 shows that neighboring amino acids in the Kcv selectivity filter affect blocker binding. CONCLUSIONS/SIGNIFICANCE:The data support the idea that permeant ions have an integral role in stabilizing potassium channel structure, suggest that both barium and amantadine act at a similar site, and demonstrate how genetic selections can be used to map blocker binding sites and reveal mechanistic features

    Genomic Sequence Analysis of Granulovirus Isolated from the Tobacco Cutworm, Spodoptera litura

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    Background: Spodoptera litura is a noctuid moth that is considered an agricultural pest. The larvae feed on a wide range of plants and have been recorded on plants from 40 plant families (mostly dicotyledons). It is a major pest of many crops. To better understand Spodoptera litura granulovirus (SpliGV), the nucleotide sequence of the SpliGV DNA genome was determined and analyzed. Methodology/Principal Findings: The genome of the SpliGV was completely sequenced. The nucleotide sequence of the SpliGV genome was 124,121 bp long with 61.2 % A+T content and contained 133 putative open reading frames (ORFs) of 150 or more nucleotides. The 133 putative ORFs covered 86.3 % of the genome. Among these, 31 ORFs were conserved in most completely sequenced baculovirus genomes, 38 were granulovirus (GV)-specific, and 64 were present in some nucleopolyhedroviruses (NPVs) and/or GVs. We proved that 9 of the ORFs were SpliGV specific. Conclusions/Significance: The genome of SpliGV is 124,121 bp in size. One hundred thirty-three ORFs that putatively encode proteins of 50 or more amino acid residues with minimal overlap were determined. No chitinase or cathepsin genes, which are involved in the liquefaction of the infected host, were found in the SpliGV genome, explaining why SpliGVinfected insects do not degrade in a typical manner. The DNA photolyase gene was first found in the genus Granulovirus. When phylogenic relationships were analyzed, the SpliGV was most closely related to Trichoplusia ni granulovirus (TnGV
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