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19 apr 2014 04:00

Background: Physical activity (PA) levels in older adults decline with age. The prevalence and correlates of adherence to current UK PA guidelines in older adults has not been studied using objectively measured PA, which can examine precisely whether PA is carried out in bouts of specified length and intensity. Methods: Free living men and women aged 70-93 years from 25 towns in the United Kingdom, participating in parallel an on-going population based cohort studies were invited (by post) to wear a GT3x accelerometer over the hip for one week in 2010-12. Adherence to UK PA guidelines was defined as >=150 minutes/week of moderate or vigorous PA (MVPA) in bouts of >=10 minutes; the effect of different intensities and durations were examined. Results: 1593 men and 857 women participated (responses 51% and 29% respectively). 15% men and 10% women achieved >=150 minutes/week of MVPA (defined as >1040 cpm) in bouts lasting >=10 minutes. With MVPA defined as >1952 cpm, prevalences were 7% and 3% respectively. Those adhering to guidelines were younger, had fewer chronic health conditions, less depression, less severe mobility limitations, but higher exercise self-efficacy and exercise outcomes expectations. They rated their local environment more highly for social activities and leisure facilities, having somewhere nice to go for a walk and feeling safe after dark, They left the house on more days per week, and were more likely to use active transport (cycle or walk) and to walk a dog regularly. Conclusions: Few older adults attain current PA guidelines. Health promotion to extend the duration of moderate-intensity activity episodes to 10 minutes or more could yield important health gains among older adults. However future studies will need to clarify whether attaining guideline amounts of PA in spells lasting 10 minutes or more is critical for reducing chronic disease risks as well as improving cardiometabolic risk factors.

biologia | biomed central - latest articles

19 apr 2014 04:00

Evaluation of EMG, force and joystick as control interfaces for active arm supports

Background: The performance capabilities and limitations of control interfaces for the operation of activemovement-assistive devices remain unclear. Selecting an optimal interface for an application requiresa thorough understanding of the performance of multiple control interfaces. Methods: In this study the performance of EMG-, force- and joystick-based control interfaces were assessedin healthy volunteers with a screen-based one-dimensional position-tracking task. The participantshad to track a target that was moving according to a multisine signal with a bandwidth of 3 Hz.The velocity of the cursor was proportional to the interface signal. The performance of the controlinterfaces were evaluated in terms of tracking error, gain margin crossover frequency, informationtransmission rate and effort. Results: None of the evaluated interfaces was superior in all four performance descriptors. The EMG-basedinterface was superior in tracking error and gain margin crossover frequency compared to the forceandthe joystick-based interfaces. The force-based interface provided higher information transmissionrate and lower effort than the EMG-based interface. The joystick-based interface did not present anysignificant difference with the force-based interface for any of the four performance descriptors. Wefound that significant differences in terms of tracking error and information transmission rate werepresent beyond 0.9 and 1.4 Hz respectively. Conclusions: Despite the fact that the EMG-based interface is far from the natural way of interacting with the environment,while the force-based interface is closer, the EMG-based interface presented very similar andfor some descriptors even a better performance than the force-based interface for frequencies below1.4 Hz. The classical joystick presented a similar performance to the force-based interface and holdsthe advantage of being a well established interface for the control of many assistive devices. Fromthese findings we concluded that all the control interfaces considered in this study can be regarded asa candidate interface for the control of an active arm support.

biologia | biomed central - latest articles

19 apr 2014 04:00

IntroductionIn women with breast cancer who smoke, it is unclear whether smoking could impair their survival from the disease. Methods: We examined the relation of smoking at diagnosis to breast cancer-specific and overall survival among 5,892 women with invasive breast cancer treated in one Canadian center (1987 to 2008). Women were classified as never, former or current smokers. Current smokers were further classified according to total, intensity and duration of smoking. Deaths were identified through linkage to population mortality data. Cox proportional-hazards multivariate models were used. A systematic review with meta-analysis combines new findings with published results. Results: Compared with never smokers, current smokers at diagnosis had a slightly, but not statistically significant, higher breast cancer-specific mortality (hazard ratio = 1.15, 95% confidence interval (CI): 0.97-1.37). Among current smokers, breast cancer-specific mortality increased with total exposure to, intensity and duration of smoking (all Ptrend <0.05). Compared to never smokers, breast cancer-specific mortality was 32 to 56% higher among heavy smokers (more than 30 pack years of smoking, more than 20 cigarettes per day or more than 30 years of smoking). Smoking at diagnosis was associated with an increased all-cause mortality rate. A meta-analysis of all studies showed a statistically significant, 33% increased mortality from breast cancer in women with breast cancer who are smokers at diagnosis compared to never smokers (hazard ratio = 1.33, 95% CI: 1.12-1.58). Conclusions: Available evidence to date indicates that smoking at diagnosis is associated with a reduction of both overall and breast cancer-specific survival. Studies of the effect of smoking cessation after diagnosis on breast cancer-specific outcomes are needed.

biologia | biomed central - latest articles

19 apr 2014 04:00

Leukemoid reaction in sarcomatoid renal cell carcinoma: a two-case report

Leukemoid reaction is defined as reactive leukocytosis exceeding 40 x 109/l, with a significant increase in early neutrophil precursors, and can be a paraneoplastic manifestation of various malignant tumors. Leukemoid reaction is a sign for poor prognosis in solid tumors so is sarcomatoid renal cell carcinoma (SRCC) when compared to more differentiated histologies. Here, we are reporting two cases of leukemoid reaction after radical nephrectomy, both of which were diagnosed as SRCC pathologically. The operations were successful: no complications were observed and the patients were discharged in good condition. However, a few weeks later, the white blood cell (WBC) count gradually increased. Even though routine management was done immediately, the count was still elevating. A diagnosis of a leukemoid reaction was established and both of them died shortly thereafter. Due to the poor prognosis of most patients with malignant leukemoid reaction, leukemoid reaction may be a predictor of prognosis in patients with SRCC, but more data are needed.

biologia | biomed central - latest articles

19 apr 2014 04:00

Biochemical and functional characterization of Plasmodium falciparum GTP cyclohydrolase I

Background: Antifolates are currently in clinical use for malaria preventive therapy and treatment. The drugs kill the parasites by targeting the enzymes in the de novo folate pathway. The use of antifolates has now been limited by the spread of drug-resistant mutations. GTP cyclohydrolase I (GCH1) is the first and the rate-limiting enzyme in the folate pathway. The amplification of the gch1 gene found in certain Plasmodium falciparum isolates can cause antifolate resistance and influence the course of antifolate resistance evolution. These findings showed the importance of P. falciparum GCH1 in drug resistance intervention. However, little is known about P. falciparum GCH1 in terms of kinetic parameters and functional assays, precluding the opportunity to obtain the key information on its catalytic reaction and to eventually develop this enzyme as a drug target. Methods: Plasmodium falciparum GCH1 was cloned and expressed in bacteria. Enzymatic activity was determined by the measurement of fluorescent converted neopterin with assay validation by using mutant and GTP analogue. The genetic complementation study was performed in [increment]folE bacteria to functionally identify the residues and domains of P. falciparum GCH1 required for its enzymatic activity. Plasmodial GCH1 sequences were aligned and structurally modeled to reveal conserved catalytic residues. Results: Kinetic parameters and optimal conditions for enzymatic reactions were determined by the fluorescence-based assay. The inhibitor test against P. falciparum GCH1 is now possible as indicated by the inhibitory effect by 8-oxo-GTP. Genetic complementation was proven to be a convenient method to study the function of P. falciparum GCH1. A series of domain truncations revealed that the conserved core domain of GCH1 is responsible for its enzymatic activity. Homology modelling fits P. falciparum GCH1 into the classic Tunnelling-fold structure with well-conserved catalytic residues at the active site. Conclusions: Functional assays for P. falciparum GCH1 based on enzymatic activity and genetic complementation were successfully developed. The assays in combination with a homology model characterized the enzymatic activity of P. falciparum GCH1 and the importance of its key amino acid residues. The potential to use the assay for inhibitor screening was validated by 8-oxo-GTP, a known GTP analogue inhibitor.

biologia | biomed central - latest articles

18 apr 2014 04:00

Surveillance leads to rabies reduction

Background: Rabies reemerged in China during the 1990s with a gradual increase in the number and geographical dispersion of cases. As a consequence, a national surveillance program was introduced in 2005 to investigate the outbreak in terms of vaccination coverage, PEP treatment, and geographical and social composition. Methods: The surveillance program was coordinated at the national level by the Chinese Center for Disease Control (CCDC) with data collected by regional health centres and provincial CCDCs, and from other official sources. Various statistical and multivariate analysis techniques were then used to evaluate the role and significance of implemented policies and strategies related to rabies prevention and control over this period. Results: From 2005-2012, 19,221 cases were reported across 30 provinces, but these primarily occurred in rural areas of southern and eastern China, and were predominantly associated with farmers, students and preschool children. In particular, detailed analysis of fatalities reported from 2010 to 2011 shows they were associated with very low rates of post exposure treatment compared to the cases with standard PEP. Nevertheless, regulation of post-exposure prophylaxis quality, together with improved management and vaccination of domesticated animals, has improved prevention and control of rabies. Conclusions: The various control policies implemented by the government has played a key role in reducing rabies incidences in China. However, level of PEP treatment varies according to sex, age, degree and site of exposure, as well as the source of infection. Regulation of PEP quality together with improved management and vaccination of domesticated animals have also helped to improve prevention and control of rabies.

biologia | biomed central - latest articles

18 apr 2014 04:00

Adaptive plasticity in the mouse mandible

Background: Plasticity, i.e. non-heritable morphological variation, enables organisms to modify the shape of their skeletal tissues in response to varying environmental stimuli. Plastic variation may also allow individuals to survive in the face of new environmental conditions, enabling the evolution of heritable adaptive traits. However, it is uncertain whether such a plastic response of morphology constitutes an evolutionary adaption itself. Here we investigate whether shape differences due to plastic bone remodelling have functionally advantageous biomechanical consequences in mouse mandibles. Shape characteristics of mandibles from two groups of inbred laboratory mice fed either rodent pellets or ground pellets mixed with jelly were assessed using geometric morphometrics and mechanical advantage measurements of jaw adductor musculature. Results: Mandibles raised on diets with differing food consistency showed significant differences in shape, which in turn altered their biomechanical profile. Mice raised on a soft food diet show a reduction in mechanical advantage relative to mice of the same inbred strain raised on a typical hard food diet. Further, the soft food eaters showed lower levels of integration between jaw regions, particularly between the molar and angular region relative to hard food eaters. Conclusions: Bone remodelling in mouse mandibles allows for significant shifts in biomechanical ability. Food consistency significantly influences this process in an adaptive direction, as mice raised on hard food develop jaws better suited to handle hard foods. This remodelling also affects the organisation of the mandible, as mice raised on soft food appear to be released from developmental constraints showing less overall integration than those raised on hard foods, but with a shift of integration towards the most solicited regions of the mandible facing such a food, namely the incisors. Our results illustrate how environmentally driven plasticity can lead to adaptive functional changes that increase biomechanical efficiency of food processing in the face of an increased solicitation. In contrast, decreased demand in terms of food processing seems to release developmental interactions between jaw parts involved in mastication, and may generate new patterns of co-variation, possibly opening new directions to subsequent selection. Overall, our results emphasize that mandible shape and integration evolved as parts of a complex system including mechanical loading food resource utilization and possibly foraging behaviour.

biologia | biomed central - latest articles

18 apr 2014 04:00

Background: The current paper presents a pilot study of interactive assessment using information and communication technology (ICT) to evaluate the knowledge, skills and abilities of staff with no formal education who are working in Swedish elderly care. Methods: Theoretical and practical assessment methods were developed and used with simulated patients and computer-based tests to identify strengths and areas for personal development among staff with no formal education. Results: Of the 157 staff with no formal education, 87 began the practical and/or theoretical assessments, and 63 completed both assessments. Several of the staff passed the practical assessments, except the morning hygiene assessment, where several failed. Other areas for staff development, i.e. where several failed (>50%), were the theoretical assessment of the learning objectives: Health, Oral care, Ergonomics, hygiene, esthetic, environmental, Rehabilitation, Assistive technology, Basic healthcare and Laws and organization. None of the staff passed all assessments. Number of years working in elderly care and staff age were not statistically significantly related to the total score of grades on the various learning objectives. Conclusion: The interactive assessments were useful in assessing staff members' practical and theoretical knowledge, skills, and abilities and in identifying areas in need of development. It is important that personnel who lack formal qualifications be clearly identified and given a chance to develop their competence through training, both theoretical and practical. The interactive e-assessment approach analyzed in the present pilot study could serve as a starting point.

biologia | biomed central - latest articles

18 apr 2014 04:00

Evaluation of the Acute Flacid Paralysis (AFP) Surveillance System in Bikita District Masvingo Province 2010

Background: AFP is a rare syndrome and serves as a proxy for poliomyelitis. The main objective of AFP surveillance is to detect circulating wild polio virus and provide data for developing effective prevention and control strategies as well planning and decision making. Bikita district failed to detect a case for the past two years.FindingsA total of 31 health workers from 14 health centres were interviewed. Health worker knowledge on AFP was low in Bikita. The system was acceptable, flexible, and representative but not stable and not sensitive since it missed1 AFP case. The system was not useful to the district since data collected was not locally used in anyway. The cost of running the system was high. The district had no adequate resources to run the system. Reasons for not reporting cases was that the mothers were not bringing children with AFP and ignorance of health workers on syndromes captured under AFP. Conclusion: Health worker's knowledge on AFP was low and all interviewed workers needed training surveillance. The system was found to be flexible but unacceptable. Reasons for failure to detect AFP cases could be, no cases reporting to the centres, lack of knowledge on health workers hence failure to recognise symptoms, high staff turnover.

biologia | biomed central - latest articles

18 apr 2014 04:00

Isolation and characterization of H9N2 influenza virus isolates from poultry respiratory disease outbreak

The present study reports isolation and characterization of H9N2 virus responsible for disease characterized by symptoms including difficulty in respiration, head swelling, nasal discharge, reduced feed intake, cyanotic comb, reduced egg production and mortality. Virus isolation from allantoic fluid inoculated with tracheal aspirates and whole genome sequencing of two isolates were performed on an Ion-Torrent sequencer. Phylogenetic analysis revealed that the two H9N2 isolates are reassortant viruses showing a G1-like lineage for HA, NA and NP, a Hok/49/98-like lineage for PB1 and PA, PK/UDL-01/05-like lineage for PB2, IL/90658/00-like lineage for NS and an unknown lineage for M gene. Analyses of the HA cleavage site showed a sequence of (333PARSSR[downwards arrow]GL340) indicating that these isolates are of low pathogenicity. Isolate 2 has leucine at amino acid position 226, a substitution which is associated with mammalian adaptation of avian influenza virus. Isolate 1 has the S31N substitution in the M2 gene that has been associated with drug resistance as well as R57Q and C241Y mutations in the NP gene which are associated with human adaptation. The result reported here gives deep insight in to H9N2 viruses circulating in domestic poultry of India and supports the policy of active efforts to control and manage H9N2 infections in Indian poultry.

biologia | biomed central - latest articles