420 research outputs found

    Origination of the Split Structure of Spliceosomal Genes from Random Genetic Sequences

    Get PDF
    The mechanism by which protein-coding portions of eukaryotic genes came to be separated by long non-coding stretches of DNA, and the purpose for this perplexing arrangement, have remained unresolved fundamental biological problems for three decades. We report here a plausible solution to this problem based on analysis of open reading frame (ORF) length constraints in the genomes of nine diverse species. If primordial nucleic acid sequences were random in sequence, functional proteins that are innately long would not be encoded due to the frequent occurrence of stop codons. The best possible way that a long protein-coding sequence could have been derived was by evolving a split-structure from the random DNA (or RNA) sequence. Results of the systematic analyses of nine complete genome sequences presented here suggests that perhaps the major underlying structural features of split-genes have evolved due to the indigenous occurrence of split protein-coding genes in primordial random nucleotide sequence. The results also suggest that intron-rich genes containing short exons may have been the original form of genes intrinsically occurring in random DNA, and that intron-poor genes containing long exons were perhaps derived from the original intron-rich genes

    Adaptive Evolution of a Stress Response Protein

    Get PDF
    Some cancers are mediated by an interplay between tissue damage, pathogens and localised innate immune responses, but the mechanisms that underlie these linkages are only beginning to be unravelled.Here we identify a strong signature of adaptive evolution on the DNA sequence of the mammalian stress response gene SEP53, a member of the epidermal differentiation complex fused-gene family known for its role in suppressing cancers. The SEP53 gene appears to have been subject to adaptive evolution of a type that is commonly (though not exclusively) associated with coevolutionary arms races. A similar pattern of molecular evolution was not evident in the p53 cancer-suppressing gene.Our data thus raises the possibility that SEP53 is a component of the mucosal/epithelial innate immune response engaged in an ongoing interaction with a pathogen. Although the pathogenic stress mediating adaptive evolution of SEP53 is not known, there are a number of well-known candidates, in particular viruses with established links to carcinoma

    Impact of associated injuries in the Floating knee: A retrospective study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Floating knee injuries are usually associated with other significant injuries. Do these injuries have implications on the management of the floating knee and the final outcome of patients? Our study aims to assess the implications of associated injuries in the management and final outcome of floating knee.</p> <p>Methods</p> <p>29 patients with floating knees were assessed in our institution. A retrospective analysis of medical records and radiographs were done and all associated injuries were identified. The impact of associated injuries on delay in initial surgical management, delay in rehabilitation & final outcome of the floating knee were assessed.</p> <p>Results</p> <p>38 associated injuries were noted. 7 were associated with ipsilateral knee injuries. Lower limb injuries were most commonly associated with the floating knee. Patients with some associated injuries had a delay in surgical management and others a delay in post-operative rehabilitation. Knee ligament and vascular injuries were associated with poor outcome.</p> <p>Conclusion</p> <p>The associated injuries were quite frequent with the floating knee. Some of the associated injuries caused a delay in surgical management and post-operative rehabilitation. In assessment of the final outcome, patients with associated knee and vascular injuries had a poor prognosis. Majority of the patients with associated injuries had a good or excellent outcome.</p

    Influence of secondary neutrons induced by proton radiotherapy for cancer patients with implantable cardioverter defibrillators

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Although proton radiotherapy is a promising new approach for cancer patients, functional interference is a concern for patients with implantable cardioverter defibrillators (ICDs). The purpose of this study was to clarify the influence of secondary neutrons induced by proton radiotherapy on ICDs.</p> <p>Methods</p> <p>The experimental set-up simulated proton radiotherapy for a patient with an ICD. Four new ICDs were placed 0.3 cm laterally and 3 cm distally outside the radiation field in order to evaluate the influence of secondary neutrons. The cumulative in-field radiation dose was 107 Gy over 10 sessions of irradiation with a dose rate of 2 Gy/min and a field size of 10 × 10 cm<sup>2</sup>. After each radiation fraction, interference with the ICD by the therapy was analyzed by an ICD programmer. The dose distributions of secondary neutrons were estimated by Monte-Carlo simulation.</p> <p>Results</p> <p>The frequency of the power-on reset, the most serious soft error where the programmed pacing mode changes temporarily to a safety back-up mode, was 1 per approximately 50 Gy. The total number of soft errors logged in all devices was 29, which was a rate of 1 soft error per approximately 15 Gy. No permanent device malfunctions were detected. The calculated dose of secondary neutrons per 1 Gy proton dose in the phantom was approximately 1.3-8.9 mSv/Gy.</p> <p>Conclusions</p> <p>With the present experimental settings, the probability was approximately 1 power-on reset per 50 Gy, which was below the dose level (60-80 Gy) generally used in proton radiotherapy. Further quantitative analysis in various settings is needed to establish guidelines regarding proton radiotherapy for cancer patients with ICDs.</p

    Metastases from renal cell carcinoma presenting as gastrointestinal bleeding: two case reports and a review of the literature

    Get PDF
    BACKGROUND: Bleeding from small bowel neoplasms account for 1–4% of cases of upper gastrointestinal haemorrhage. Renal cell carcinoma constitutes 3% of all adult malignancies and often presents insidiously. Consequently 25–30% of patients have metastases at the time of diagnosis. Gastrointestinal bleeding from renal cell carcinoma metastases is an uncommon and under-recognised manifestation of this disease. CASE REPORT: In this report we describe two cases of gastrointestinal bleeding from renal cell carcinoma metastases – in one patient bleeding heralded the primary manifestation of disease and in the other signified recurrence of disease following nephrectomy. CONCLUSION: These cases highlight the importance endoscopic vigilance in cases of undiagnosed upper gastrointestinal haemorrhage, especially in patients with a past history of renal cell carcinoma

    ConservedPrimers 2.0: A high-throughput pipeline for comparative genome referenced intron-flanking PCR primer design and its application in wheat SNP discovery

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>In some genomic applications it is necessary to design large numbers of PCR primers in exons flanking one or several introns on the basis of orthologous gene sequences in related species. The primer pairs designed by this target gene approach are called "intron-flanking primers" or because they are located in exonic sequences which are usually conserved between related species, "conserved primers". They are useful for large-scale single nucleotide polymorphism (SNP) discovery and marker development, especially in species, such as wheat, for which a large number of ESTs are available but for which genome sequences and intron/exon boundaries are not available. To date, no suitable high-throughput tool is available for this purpose.</p> <p>Results</p> <p>We have developed, the ConservedPrimers 2.0 pipeline, for designing intron-flanking primers for large-scale SNP discovery and marker development, and demonstrated its utility in wheat. This tool uses non-redundant wheat EST sequences, such as wheat contigs and singleton ESTs, and related genomic sequences, such as those of rice, as inputs. It aligns the ESTs to the genomic sequences to identify unique colinear exon blocks and predicts intron lengths. Intron-flanking primers are then designed based on the intron/exon information using the Primer3 core program or BatchPrimer3. Finally, a tab-delimited file containing intron-flanking primer pair sequences and their primer properties is generated for primer ordering and their PCR applications. Using this tool, 1,922 bin-mapped wheat ESTs (31.8% of the 6,045 in total) were found to have unique colinear exon blocks suitable for primer design and 1,821 primer pairs were designed from these single- or low-copy genes for PCR amplification and SNP discovery. With these primers and subsequently designed genome-specific primers, a total of 1,527 loci were found to contain one or more genome-specific SNPs.</p> <p>Conclusion</p> <p>The ConservedPrimers 2.0 pipeline for designing intron-flanking primers was developed and its utility demonstrated. The tool can be used for SNP discovery, genetic variation assays and marker development for any target genome that has abundant ESTs and a related reference genome that has been fully sequenced. The ConservedPrimers 2.0 pipeline has been implemented as a command-line tool as well as a web application. Both versions are freely available at <url>http://wheat.pw.usda.gov/demos/ConservedPrimers/</url>.</p

    Production of ultrasonic vocalizations by Peromyscus mice in the wild

    Get PDF
    BACKGROUND: There has been considerable research on rodent ultrasound in the laboratory and these sounds have been well quantified and characterized. Despite the value of research on ultrasound produced by mice in the lab, it is unclear if, and when, these sounds are produced in the wild, and how they function in natural habitats. RESULTS: We have made the first recordings of ultrasonic vocalizations produced by two free-living species of mice in the genus Peromyscus (P. californicus and P. boylii) on long term study grids in California. Over 6 nights, we recorded 65 unique ultrasonic vocalization phrases from Peromyscus. The ultrasonic vocalizations we recorded represent 7 different motifs. Within each motif, there was considerable variation in the acoustic characteristics suggesting individual and contextual variation in the production of ultrasound by these species. CONCLUSION: The discovery of the production of ultrasonic vocalizations by Peromyscus in the wild highlights an underappreciated component in the behavior of these model organisms. The ability to examine the production of ultrasonic vocalizations in the wild offers excellent opportunities to test hypotheses regarding the function of ultrasound produced by rodents in a natural context

    Implementing chlamydia screening: what do women think? A systematic review of the literature

    Get PDF
    BACKGROUND: Chlamydia trachomatis is a common sexually transmitted infection that can have serious consequences. It is universally agreed that screening for chlamydia infection should be offered to sexually active young women. We undertook a literature review to document the views, attitudes and opinions of women about being screened, tested and diagnosed with Chlamydia trachomatis. METHODS: Online databases (MEDLINE, Meditext, PsycINFO, Web of Science) and reference lists searched up to August 2005. Search terms: chlamydia, attitude, attitude to health, interview, qualitative, women. Eligibility criteria: about chlamydia, included women, involved interviews/surveys/focus groups, looked at women's views/opinions/attitudes, published in English. Thematic analysis identified the main and recurrent themes emerging from the literature. We compared our thematic analysis with the Theory of Planned Behaviour to provide a model that could assist in planning chlamydia screening programs. RESULTS: From 561 identified articles, 25 fulfilled inclusion criteria and were reviewed. 22: USA, UK; 3: Holland, Sweden, Australia. Major themes identified: need for knowledge and information, choice and support; concerns about confidentiality, cost, fear, anxiety and stigma. Women are more likely to find chlamydia screening/testing acceptable if they think chlamydia is a serious, common condition which can cause infertility and if they understand that chlamydia infection can be asymptomatic. Women want a range of options for chlamydia testing including urine tests, self-administered swabs, pelvic exams and clinician-collected swabs, home-testing and community-based testing. Tests should be free, easy and quick. Women want support for dealing with the implications of a chlamydia diagnosis, they feel chlamydia diagnoses need to be normalised and destigmatised and they want assistance with partner notification. Women need to know that their confidentiality will be maintained. CONCLUSION: Our review found that women from various countries and ethnic backgrounds share similar views regarding chlamydia screening, testing and diagnosis. The acknowledged importance of women's views in planning an effective chlamydia screening program is expanded in this review which details the nature and complexity of such views and considers their likely impact

    Evaluation of groundwater quality and its suitability for drinking and agricultural use in Thanjavur city, Tamil Nadu, India

    Get PDF
    As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO3). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry.Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for irrigation. Both integrated suitability maps for drinking and irrigation usage provide overall scenario about the groundwater quality in the study area. Finally, the study concluded that groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources inThanjavur city

    Barriers and facilitators to implementing workplace health and wellbeing services in the NHS from the perspective of senior leaders and wellbeing practitioners: a qualitative study

    Get PDF
    Abstract Background The National Health Service (NHS) seems appropriately placed to be an exemplar employer in providing effective and proactive workplace health and wellbeing services for its staff. However, NHS staff sickness absence costs an estimated £2.4 billion. Evidence suggests staff health and wellbeing services delivered in the NHS can improve health, productivity and sickness absence and yet the adoption of these services remains a challenge, with few examples nationally. This research aimed to explore the perceptions of NHS senior leaders and health and wellbeing practitioners regarding barriers and facilitators to implementing workplace health and wellbeing services for staff in the NHS. Methods Semi-structured interviews were conducted with NHS staff, consisting of four senior leaders, four heads of department and three health and wellbeing practitioners in one region of the UK. Interviews were transcribed verbatim and analysed using thematic analysis. Results Themes describe the experience of delivering workplace health and wellbeing services in the NHS, and barriers and facilitators to implementation from senior decision makers. Barriers to implementation of services include; a busy and pressurised environment, financial constraints and reluctance to invest in staff health and wellbeing. Barriers to staff engagement were also reported and include difficulty of access to health and wellbeing services and lack of time. Initiating services were facilitated by financial incentives, a supportive organisational structure and culture that takes a preventative, rather than reactive, approach to staff health and wellbeing. Facilitators to implementing health and wellbeing services include a coherent, strategic approach to implementation, effective communication and advertisement, being creative and innovative with resources and conducting a needs analysis and evaluation before, during and after implementation. Conclusions Barriers to the successful initiation and implementation of health and wellbeing services in the NHS are numerous and range from front-line logistical issues with implementation to high-level strategic and financial constraints. Adopting a strategic and needs-led approach to implementation and ensuring thorough staff engagement are amongst a number of factors that facilitate implementation and help overcome barriers to initiation of wellbeing programmes in the NHS. There is a need for a culture that supports staff health and wellbeing in the NHS
    corecore