213 research outputs found

    Communicating curriculum reform to students: Advice in hindsight.....

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    BACKGOUND: In view of the changing health care needs of communities, curriculum reform of traditional curricula is inevitable. In order to allay the apprehension that may accompany such change, curriculum development and implementation should be an inclusive process, with both staff and students being well informed of the planned reform. In 2001, the Nelson R. Mandela School of Medicine implemented Year 1 of a problem-based learning curriculum. During the design phase, students and staff were invited to take part in the development and were kept abreast of developments through meetings and newsletters. METHOD: A survey of Years 1–5 students of the last intake into the traditional curriculum was undertaken a few months prior to the implementation of the new programme. RESULTS: Students were generally well informed about the impending change, having heard about it from fellow students and staff. The more senior the students, the less the perceived impact of the reform. Although most of what students had heard was correct, some, however, had misconceptions that were generally extreme views (e.g. all self-directed learning; no Anatomy) about the new programme. Others expressed valid concerns (e.g. underpreparedness of students from disadvantaged schools; overcrowding in hospitals). CONCLUSIONS: Advice offered to institutions considering curriculum reform include using various methods to inform internal and external affected parties, ensuring that the student representative body and staff is well informed, reiterating the need for the change, confirming that the new programme meets recognised standards and that the students most affected are reassured about their future studies

    Application of the PM6 method to modeling the solid state

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    The applicability of the recently developed PM6 method for modeling various properties of a wide range of organic and inorganic crystalline solids has been investigated. Although the geometries of most systems examined were reproduced with good accuracy, severe errors were found in the predicted structures of a small number of solids. The origin of these errors was investigated, and a strategy for improving the method proposed

    Envelope 2 protein phosphorylation sites S75 & 277 of hepatitis C virus genotype 1a and interferon resistance: A sequence alignment approach

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    <p>Abstract</p> <p>Background</p> <p>Hepatitis C is a major health problem affecting more than 200 million individuals in world including Pakistan. Current treatment regimen consisting of interferon alpha and ribavirin does not always succeed to eliminate virus completely from the patient's body.</p> <p>Results</p> <p>Interferon induced antiviral protein kinase R (PKR) has a role in the hepatitis C virus (HCV) treatment as dsRNA activated PKR has the capacity to phosphorylate the serine and threonine of E2 protein and dimerization viral RNA. E2 gene of hepatitis C virus (HCV) genotype 1 has an active role in IFN resistance. E2 protein inhibits and terminates the kinase activity of PKR by blocking it in protein synthesis and cell growth. This brings forward a possible relation of E2 and PKR through a mechanism via which HCV evades the antiviral effect of IFN.</p> <p>Conclusion</p> <p>A hybrid in-silico and wet laboratory approach of motif prediction, evolutionary and structural anlysis has pointed out serine 75 and 277 of the HCV E2 gene as a promising candidate for the serine phosphorylation. It is proposed that serine phosphorylation of HCV E2 gene has a significant role in interferon resistance.</p

    Individualised and complex experiences of integrative cancer support care: combining qualitative and quantitative data

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    Objectives: The widespread use of complementary therapies alongside biomedical treatment by people with cancer is not supported by evidence from clinical trials. We aimed to use combined qualitative and quantitative data to describe and measure individualised experiences and outcomes. Materials and methods In three integrative cancer support centres (two breast cancer only) in the UK, consecutive patients completed the individualised outcome questionnaire Measure Yourself Concerns and Wellbeing (MYCaW) before and after treatment. MYCaW collects quantitative data (seven-point scales) and written qualitative data and the qualitative data were analysed using published categories. Results: Seven hundred eighty-two participants, 92% female, mean age 51 years, nominated a wide range of concerns. Psychological and emotional concerns predominated. At follow-up, the mean change (improvement) in scores (n = 588) were: concern 1, 2.06 (95% CI 1.92–2.20); concern 2, 1.74 (95% CI 1.60–1.90); and well-being, 0.64 (95% CI 0.52–0.75). The most common responses to ‘what has been the most important aspect for you?’ were ‘receiving complementary therapies on an individual or group basis’ (26.2%); ‘support and understanding received from therapists’ (17.1%) and ‘time spent with other patients at the centres’ (16.1%). Positive (61.5%) and negative (38.5%) descriptions of ‘other things affecting your health’ correlated with larger and smaller improvement in concerns and well-being, respectively. Conclusions: In a multicentre evaluation, the MYCaW questionnaire provides rich data about patient experience, changes over time and perceptions of what was important to each individual with cancer within that experience. It is unlikely that meaningful evaluations of this complex intervention could be carried out by quantitative methods alone

    The farther, the safer: a manifesto for securely navigating synthetic species away from the old living world

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    Biotechnology has empirically established that it is easier to construct and evaluate variant genes and proteins than to account for the emergence and function of wild-type macromolecules. Systematizing this constructive approach, synthetic biology now promises to infer and assemble entirely novel genomes, cells and ecosystems. It is argued here that the theoretical and computational tools needed for this endeavor are missing altogether. However, such tools may not be required for diversifying organisms at the basic level of their chemical constitution by adding, substituting or removing elements and molecular components through directed evolution under selection. Most importantly, chemical diversification of life forms could be designed to block metabolic cross-feed and genetic cross-talk between synthetic and wild species and hence protect natural habitats and human health through novel types of containment

    Trypanosoma brucei PUF9 Regulates mRNAs for Proteins Involved in Replicative Processes over the Cell Cycle

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    Many genes that are required at specific points in the cell cycle exhibit cell cycle–dependent expression. In the early-diverging model eukaryote and important human pathogen Trypanosoma brucei, regulation of gene expression in the cell cycle and other processes is almost entirely post-transcriptional. Here, we show that the T. brucei RNA-binding protein PUF9 stabilizes certain transcripts during S-phase. Target transcripts of PUF9—LIGKA, PNT1 and PNT2—were identified by affinity purification with TAP-tagged PUF9. RNAi against PUF9 caused an accumulation of cells in G2/M phase and unexpectedly destabilized the PUF9 target mRNAs, despite the fact that most known Puf-domain proteins promote degradation of their target mRNAs. The levels of the PUF9-regulated transcripts were cell cycle dependent, peaking in mid- to late- S-phase, and this effect was abolished when PUF9 was targeted by RNAi. The sequence UUGUACC was over-represented in the 3′ UTRs of PUF9 targets; a point mutation in this motif abolished PUF9-dependent stabilization of a reporter transcript carrying the PNT1 3′ UTR. LIGKA is involved in replication of the kinetoplast, and here we show that PNT1 is also kinetoplast-associated and its over-expression causes kinetoplast-related defects, while PNT2 is localized to the nucleus in G1 phase and redistributes to the mitotic spindle during mitosis. PUF9 targets may constitute a post-transcriptional regulon, encoding proteins involved in temporally coordinated replicative processes in early G2 phase

    Influenza A Virus Nucleoprotein Exploits Hsp40 to Inhibit PKR Activation

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    BACKGROUND: Double-stranded RNA dependent protein kinase (PKR) is a key regulator of the anti-viral innate immune response in mammalian cells. PKR activity is regulated by a 58 kilo Dalton cellular inhibitor (P58(IPK)), which is present in inactive state as a complex with Hsp40 under normal conditions. In case of influenza A virus (IAV) infection, P58(IPK) is known to dissociate from Hsp40 and inhibit PKR activation. However the influenza virus component responsible for PKR inhibition through P58(IPK) activation was hitherto unknown. PRINCIPAL FINDINGS: Human heat shock 40 protein (Hsp40) was identified as an interacting partner of Influenza A virus nucleoprotein (IAV NP) using a yeast two-hybrid screen. This interaction was confirmed by co-immunoprecipitation studies from mammalian cells transfected with IAV NP expressing plasmid. Further, the IAV NP-Hsp40 interaction was validated in mammalian cells infected with various seasonal and pandemic strains of influenza viruses. Cellular localization studies showed that NP and Hsp40 co-localize primarily in the nucleus. During IAV infection in mammalian cells, expression of NP coincided with the dissociation of P58(IPK) from Hsp40 and decrease PKR phosphorylation. We observed that, plasmid based expression of NP in mammalian cells leads to decrease in PKR phosphorylation. Furthermore, inhibition of NP expression during influenza virus replication led to PKR activation and concomitant increase in eIF2α phosphorylation. Inhibition of NP expression also led to reduced IRF3 phosphorylation, enhanced IFN β production and concomitant reduction of virus replication. Taken together our data suggest that NP is the viral factor responsible for P58(IPK) activation and subsequent inhibition of PKR-mediated host response during IAV infection. SIGNIFICANCE: Our findings demonstrate a novel role of IAV NP in inhibiting PKR-mediated anti-viral host response and help us understand P58(IPK) mediated inhibition of PKR activity during IAV infection

    Accelerated discovery of two crystal structure types in a complex inorganic phase field

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    The discovery of new materials is hampered by the lack of efficient approaches to the exploration of both the large number of possible elemental compositions for such materials, and of the candidate structures at each composition1. For example, the discovery of inorganic extended solid structures has relied on knowledge of crystal chemistry coupled with time-consuming materials synthesis with systematically varied elemental ratios2,3. Computational methods have been developed to guide synthesis by predicting structures at specific compositions4,5,6 and predicting compositions for known crystal structures7,8, with notable successes9,10. However, the challenge of finding qualitatively new, experimentally realizable compounds, with crystal structures where the unit cell and the atom positions within it differ from known structures, remains for compositionally complex systems. Many valuable properties arise from substitution into known crystal structures, but materials discovery using this approach alone risks both missing best-in-class performance and attempting design with incomplete knowledge8,11. Here we report the experimental discovery of two structure types by computational identification of the region of a complex inorganic phase field that contains them. This is achieved by computing probe structures that capture the chemical and structural diversity of the system and whose energies can be ranked against combinations of currently known materials. Subsequent experimental exploration of the lowest-energy regions of the computed phase diagram affords two materials with previously unreported crystal structures featuring unusual structural motifs. This approach will accelerate the systematic discovery of new materials in complex compositional spaces by efficiently guiding synthesis and enhancing the predictive power of the computational tools through expansion of the knowledge base underpinning them

    Models of Traumatic Cerebellar Injury

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    Traumatic brain injury (TBI) is a major cause of morbidity and mortality worldwide. Studies of human TBI demonstrate that the cerebellum is sometimes affected even when the initial mechanical insult is directed to the cerebral cortex. Some of the components of TBI, including ataxia, postural instability, tremor, impairments in balance and fine motor skills, and even cognitive deficits, may be attributed in part to cerebellar damage. Animal models of TBI have begun to explore the vulnerability of the cerebellum. In this paper, we review the clinical presentation, pathogenesis, and putative mechanisms underlying cerebellar damage with an emphasis on experimental models that have been used to further elucidate this poorly understood but important aspect of TBI. Animal models of indirect (supratentorial) trauma to the cerebellum, including fluid percussion, controlled cortical impact, weight drop impact acceleration, and rotational acceleration injuries, are considered. In addition, we describe models that produce direct trauma to the cerebellum as well as those that reproduce specific components of TBI including axotomy, stab injury, in vitro stretch injury, and excitotoxicity. Overall, these models reveal robust characteristics of cerebellar damage including regionally specific Purkinje cell injury or loss, activation of glia in a distinct spatial pattern, and traumatic axonal injury. Further research is needed to better understand the mechanisms underlying the pathogenesis of cerebellar trauma, and the experimental models discussed here offer an important first step toward achieving that objective
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