1,668 research outputs found
Synthesis, Crystallographic Characterization and Density Functional Study of Novel Spoke-Molecular Tetravent ethyltriphenylphosphorous Dibromide
A novel molecular tetravent ethyltriphenylphosphorous dibromide ((C6H5) 3PCH2Br2) has been synthesized in toluene and has been characterized by single crystal x-ray crystallography. Theoretical studies have been conducted utilizing DFT (B3LYP/6-311+ G (d, p) level of theory both in gas phase and solution using diverse solvents. Potential surface energy calculations revealed the existence of the tetravelent diionic form as a global minimum except in dimethylsolfoxide where our adduct is more stable. Calculations showed that the Br-Br bond distance is in quadratic variation with the medium dielectric constant. The unusual Br-Br lengthen is reasonably rationalized in terms of charge transfer of electron density from the π clouds in phenyl moieties to the σ* of the dibromine entity. The average harmonic oscillator index of aromaticity of the complex are found suffering a deviation from unity
A preliminary study of genetic factors that influence susceptibility to bovine tuberculosis in the British cattle herd
Associations between specific host genes and susceptibility to Mycobacterial infections such as tuberculosis have been reported in several species. Bovine tuberculosis (bTB) impacts greatly the UK cattle industry, yet genetic predispositions have yet to be identified. We therefore used a candidate gene approach to study 384 cattle of which 160 had reacted positively to an antigenic skin test (‘reactors’). Our approach was unusual in that it used microsatellite markers, embraced high breed diversity and focused particularly on detecting genes showing heterozygote advantage, a mode of action often overlooked in SNP-based studies. A panel of neutral markers was used to control for population substructure and using a general linear model-based approach we were also able to control for age. We found that substructure was surprisingly weak and identified two genomic regions that were strongly associated with reactor status, identified by markers INRA111 and BMS2753. In general the strength of association detected tended to vary depending on whether age was included in the model. At INRA111 a single genotype appears strongly protective with an overall odds ratio of 2.2, the effect being consistent across nine diverse breeds. Our results suggest that breeding strategies could be devised that would appreciably increase genetic resistance of cattle to bTB (strictly, reduce the frequency of incidence of reactors) with implications for the current debate concerning badger-culling
Clinical trial update: National Cancer Institute of Canada
The Breast Cancer Site Group (BCSG) of the National Cancer Institute of Canada (NCIC) Clinical Trials Group (CTG) has conducted a wide variety of clinical trials focussing on large phase III trials of adjuvant chemotherapy, adjuvant hormonal therapy, and optimal delivery of adjuvant radiation therapy. The Group has also fostered, together with the NCIC CTG Investigational New Drug (IND) Program, a series of phase II and phase I/II studies which will be carried through if possible, into the phase III setting
Contribution of magnetic resonance imaging in the diagnosis of talus skip metastases of Ewing's sarcoma of the calcaneus in a child: a case report
<p>Abstract</p> <p>Introduction</p> <p>Ewing's sarcoma of the calcaneus is rare. About thirty cases with calcaneus involvement have been reported in the literature. Talus skip metastases have rarely been described in the available literature</p> <p>Case presentation</p> <p>We report a case of a 14-year-old Moroccan boy, who presented with Ewing's sarcoma of his right calcaneus, diagnosed by swelling of the calcaneus evolving over a year. Radiography, computed tomography and magnetic resonance imaging showed an important tumoral process of the calcaneus and talus skip metastases. The diagnosis was confirmed with histology after a biopsy. In spite of amputation and postoperative chemotherapy, our patient died six months later due to secondary respiratory distress after lung metastasis.</p> <p>Conclusion</p> <p>Imaging, especially magnetic resonance, is important in the diagnosis of Ewing sarcoma and skeletal skip metastases. Treatment of Ewing's sarcoma consists of chemotherapy, radiation therapy and surgical resection depending on the stage and extent of the disease. With the exception of lesions in the calcaneus, the prognosis for disease-free survival of Ewing's sarcoma of the foot is excellent.</p
Acute effects of nicotine on visual search tasks in young adult smokers
Rationale Nicotine is known to improve performance on tests involving sustained attention and recent research suggests that nicotine may also improve performance on tests involving the strategic allocation of attention and working memory. Objectives We used measures of accuracy and response latency combined with eye-tracking techniques to examine the effects of nicotine on visual search tasks. Methods In experiment 1 smokers and non-smokers performed pop-out and serial search tasks. In experiment 2, we used a within-subject design and a more demanding search task for multiple targets. In both studies, 2-h abstinent smokers were asked to smoke one of their own cigarettes between baseline and tests. Results In experiment 1, pop-out search times were faster after nicotine, without a loss in accuracy. Similar effects were observed for serial searches, but these were significant only at a trend level. In experiment 2, nicotine facilitated a strategic change in eye movements resulting in a higher proportion of fixations on target letters. If the cigarette was smoked on the first trial (when the task was novel), nicotine additionally reduced the total number of fixations and refixations on all letters in the display. Conclusions Nicotine improves visual search performance by speeding up search time and enabling a better focus of attention on task relevant items. This appears to reflect more efficient inhibition of eye movements towards task irrelevant stimuli, and better active maintenance of task goals. When the task is novel, and therefore more difficult, nicotine lessens the need to refixate previously seen letters, suggesting an improvement in working memory
Developing an intervention to facilitate family communication about inherited genetic conditions, and training genetic counsellors in its delivery.
Many families experience difficulty in talking about an inherited genetic condition that affects one or more of them. There have now been a number of studies identifying the issues in detail, however few have developed interventions to assist families. The SPRinG collaborative have used the UK Medical Research Council's guidance on Developing and Evaluating Complex Interventions, to work with families and genetic counsellors (GCs) to co-design a psycho-educational intervention to facilitate family communication and promote better coping and adaptation to living with an inherited genetic condition for parents and their children (<18 years). The intervention is modelled on multi-family discussion groups (MFDGs) used in psychiatric settings. The MFDG was developed and tested over three phases. First focus groups with parents, young people, children and health professionals discussed whether MFDG was acceptable and proposed a suitable design. Using evidence and focus group data, the intervention and a training manual were developed and three GCs were trained in its delivery. Finally, a prototype MFDG was led by a family therapist and co-facilitated by the three GCs. Data analysis showed that families attending the focus groups and intervention thought MFDG highly beneficial, and the pilot sessions had a significant impact on their family' functioning. We also demonstrated that it is possible to train GCs to deliver the MFDG intervention. Further studies are now required to test the feasibility of undertaking a definitive randomised controlled trial to evaluate its effectiveness in improving family outcomes before implementing into genetic counselling practice.The National Institute of Health Research funded the study but any views expressed do not necessarily reflect those of the Authority. Funded by NIHR reference number: RP-DG-1211-10015
Primary cilia elongation in response to interleukin-1 mediates the inflammatory response
Primary cilia are singular, cytoskeletal organelles present in the majority of mammalian cell types where they function as coordinating centres for mechanotransduction, Wnt and hedgehog signalling. The length of the primary cilium is proposed to modulate cilia function, governed in part by the activity of intraflagellar transport (IFT). In articular cartilage, primary cilia length is increased and hedgehog signaling activated in osteoarthritis (OA). Here, we examine primary cilia length with exposure to the quintessential inflammatory cytokine interleukin-1 (IL-1), which is up-regulated in OA. We then test the hypothesis that the cilium is involved in mediating the downstream inflammatory response. Primary chondrocytes treated with IL-1 exhibited a 50 % increase in cilia length after 3 h exposure. IL-1-induced cilia elongation was also observed in human fibroblasts. In chondrocytes, this elongation occurred via a protein kinase A (PKA)-dependent mechanism. G-protein coupled adenylate cyclase also regulated the length of chondrocyte primary cilia but not downstream of IL-1. Chondrocytes treated with IL-1 exhibit a characteristic increase in the release of the inflammatory chemokines, nitric oxide and prostaglandin E2. However, in cells with a mutation in IFT88 whereby the cilia structure is lost, this response to IL-1 was significantly attenuated and, in the case of nitric oxide, completely abolished. Inhibition of IL-1-induced cilia elongation by PKA inhibition also attenuated the chemokine response. These results suggest that cilia assembly regulates the response to inflammatory cytokines. Therefore, the cilia proteome may provide a novel therapeutic target for the treatment of inflammatory pathologies, including OA
Genetic dissection of photoperiod response based on GWAS of pre-anthesis phase duration in spring barley
Heading time is a complex trait, and natural variation in photoperiod responses is a major factor controlling time to heading, adaptation and grain yield. In barley, previous heading time studies have been mainly conducted under field conditions to measure total days to heading. We followed a novel approach and studied the natural variation of time to heading in a world-wide spring barley collection (218 accessions), comprising of 95 photoperiod-sensitive (Ppd-H1) and 123 accessions with reduced photoperiod sensitivity (ppd-H1) to long-day (LD) through dissecting pre-anthesis development into four major stages and sub-phases. The study was conducted under greenhouse (GH) conditions (LD; 16/8 h; ∼20/∼16°C day/night). Genotyping was performed using a genome-wide high density 9K single nucleotide polymorphisms (SNPs) chip which assayed 7842 SNPs. We used the barley physical map to identify candidate genes underlying genome-wide association scans (GWAS). GWAS for pre-anthesis stages/sub-phases in each photoperiod group provided great power for partitioning genetic effects on floral initiation and heading time. In addition to major genes known to regulate heading time under field conditions, several novel QTL with medium to high effects, including new QTL having major effects on developmental stages/sub-phases were found to be associated in this study. For example, highly associated SNPs tagged the physical regions around HvCO1 (barley CONSTANS1) and BFL (BARLEY FLORICAULA/LEAFY) genes. Based upon our GWAS analysis, we propose a new genetic network model for each photoperiod group, which includes several newly identified genes, such as several HvCO-like genes, belonging to different heading time pathways in barley
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