864 research outputs found

    Understanding the impact of lumbar disc degeneration and chronic low back pain: A cross-sectional electromyographic analysis of postural strategy during predicted and unpredicted postural perturbations

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    People with chronic low back pain (LBP) exhibit changes in postural control. Stereotypical muscle activations resulting from external perturbations include anticipatory (APAs) and compensatory (CPAs) postural adjustments. The aim and objective of this study was to determine differences in postural control strategies (peak amplitude, APAs and CPAs) between symptomatic and asymptomatic adults with and without Lumbar Disc Degeneration (LDD) using surface electromyography during forward postural perturbation. Ninety-seven subjects participated in the study (mean age 50 years (SD 12)). 3T MRI was used to acquire T2 weighted images (L1-S1). LDD was determined using Pfirrmann grading. A bespoke translational platform was designed to deliver horizontal perturbations in sagittal and frontal planes. Electromyographic activity was analysed bilaterally from 8 trunk and lower limb muscles during four established APA and CPA epochs. A Kruskal-Wallis H test with Bonferroni correction for multiple comparisons was conducted. Four groups were identified: no LDD no pain (n = 19), LDD no pain (n = 38), LDD pain (n = 35) and no LDD pain (n = 5). There were no significant differences in age or gender between groups. The most significant difference between groups was observed during forward perturbation. In the APA and CPA phases of predictable forward perturbation there were significant differences ankle strategy between groups (p = 0.007-0.008); lateral gastrocnemius and tibialis anterior activity was higher in the LDD pain than the LDD no pain group. There were no significant differences in the unpredictable condition (p>0.05). These findings were different from the remaining groups, where significant differences in hip strategy were observed during both perturbation conditions (p = 0.004-0.006). Symptomatic LDD patients exhibit different electromyographic strategies to asymptomatic LDD controls. Future LBP electromyographic research should benefit from considering assessment of both lower limbs in addition to the spine. This approach could prevent underestimation of postural control deficits and guide targeted rehabilitation

    Dark-adapted red flash ERGs in healthy adults

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    Purpose: The x-wave of the dark-adapted (DA) ERG to a red flash reflects DA cone function. This exploratory study of healthy adults aimed to investigate changes in the DA red ERG with flash strength and during dark adaptation to optimise visualisation and therefore quantification of the x-wave. Methods: The effect of altering red flash strength was investigated in four subjects by recording ERGs after 20 minutes dark adaptation to red flashes (0.2–2.0 cd s m-2) using skin electrodes and natural pupils. The effect of dark adaptation duration was investigated in 16 subjects during 20 minutes in the dark, by recording DA 1.5 red ERGs at 1, 2, 3, 4, 5, 10, 15 and 20 minutes. Results: For a dark adaption period of 20 minutes, the x-wave was more clearly visualised to weaker (< 0.6 cd s m-2) red flash strengths: to stronger flashes it became obscured by the b-wave. For red flashes of 1.5 cd s m-2, the x-wave was most prominent in ERGs recorded after 1–5 minutes of dark adaptation: with longer dark-adaptation, it was subsumed into the b-wave’s rising edge. Conclusions: This small study suggests that x-wave visibility in healthy subjects after 20 minutes dark adaptation is improved by using flashes weaker than around 0.6 cd s m-2; for flash strengths of 1.5 cd s m-2, x-wave visibility is enhanced by recording after only around 5 minutes of dark adaptation. No evidence was found that interim red flash ERGs affecting the dark-adapted state of the normal retina

    Genome analysis of a new Rhodothermaceae strain isolated from a hot spring

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    A bacterial strain, designated RA, was isolated from water sample of a hot spring on Langkawi Island of Malaysia using marine agar. Strain RA is an aerophilic and thermophilic microorganism that grows optimally at 50-60°C and is capable of growing in marine broth containing 1-10% (w/v) NaCl. 16S rRNA gene sequence analysis demonstrated that this strain is most closely related (<90% sequence identity) to Rhodothermaceae, which currently comprises of six genera: Rhodothermus (two species), Salinibacter (three species), Salisaeta (one species), Rubricoccus (one species), Rubrivirga (one species), and Longimonas (one species). Notably, analysis of average nucleotide identity (ANI) values indicated that strain RA may represent the first member of a novel genus of Rhodothermaceae. The draft genome of strain RA is 4,616,094 bp with 3630 protein-coding gene sequences. Its GC content is 68.3%, which is higher than that of most other genomes of Rhodothermaceae. Strain RA has genes for sulfate permease and arylsulfatase to withstand the high sulfur and sulfate contents of the hot spring. Putative genes encoding proteins involved in adaptation to osmotic stress were identified which encode proteins namely Na+/H+ antiporters, a sodium/solute symporter, a sodium/glutamate symporter, trehalose synthase, malto-oligosyltrehalose synthase, choline-sulfatase, potassium uptake proteins (TrkA and TrkH), osmotically inducible protein C, and the K+ channel histidine kinase KdpD. Furthermore, genome description of strain RA and comparative genome studies in relation to other related genera provide an overview of the uniqueness of this bacterium

    A business zone recommender system based on Facebook and urban planning data

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    We present ZoneRec---a zone recommendation system for physical businesses in an urban city, which uses both public business data from Facebook and urban planning data. The system consists of machine learning algorithms that take in a business' metadata and outputs a list of recommended zones to establish the business in. We evaluate our system using data of food businesses in Singapore and assess the contribution of different feature groups to the recommendation quality

    Effectiveness and safety of sofosbuvir plus ribavirin for the treatment of HCV genotype 2 infection: results of the real-world, clinical practice HCV-TARGET study

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    Due to a high efficacy in clinical trials, sofosbuvir (SOF) and ribavirin (RBV) for 12 or 16 weeks is recommended for treatment of patients with HCV genotype (GT) 2 infection. We investigated safety and effectiveness of these regimens for GT2 in HCV-TARGET participants

    Individual variation in levels of haptoglobin-related protein in children from Gabon

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    Background: Haptoglobin related protein (Hpr) is a key component of trypanosome lytic factors (TLF), a subset of highdensity lipoproteins (HDL) that form the first line of human defence against African trypanosomes. Hpr, like haptoglobin (Hp) can bind to hemoglobin (Hb) and it is the Hpr-Hb complexes which bind to these parasites allowing uptake of TLF. This unique form of innate immunity is primate-specific. To date, there have been no population studies of plasma levels of Hpr, particularly in relation to hemolysis and a high prevalence of ahaptoglobinemia as found in malaria endemic areas. Methods and Principal Findings: We developed a specific enzyme-linked immunosorbent assay to measure levels of plasma Hpr in Gabonese children sampled during a period of seasonal malaria transmission when acute phase responses (APR), malaria infection and associated hemolysis were prevalent. Median Hpr concentration was 0.28 mg/ml (range 0.03-1.1). This was 5-fold higher than that found in Caucasian children (0.049 mg/ml, range 0.002-0.26) with no evidence of an APR. A general linear model was used to investigate associations between Hpr levels, host polymorphisms, parasitological factors and the acute phase proteins, Hp, C-reactive protein (CRP) and albumin. Levels of Hpr were associated with Hp genotype, decreased with age and were higher in females. Hpr concentration was strongly correlated with that of Hp, but not CRP

    Cyanoacrylate closure for peripheral veins: Consensus document of the Australasian College of Phlebology

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    Background: Cyanoacrylates are fast-acting adhesives used in procedural medicine including closure of superficial wounds, embolization of truncal vessels pre-operatively, vascular anomalies, visceral false aneurysms, endoleaks, gastrointestinal varices and gastrointestinal bleeding. More recently, catheter-directed cyanoacrylate adhesive closure was introduced as an alternative to endovenous thermal ablation (ETA) to occlude superficial veins of the lower limbs. Objectives: To formulate policies for the safe and effective delivery of cyanoacrylate adhesive closure procedures in Australasia, based on current experience and evidence. Methods: A panel of phlebologists including vascular surgeons, interventional radiologists, dermatologists and research scientists systematically reviewed the available data on cyanoacrylate products used in medicine and shared personal experience with the procedure. The reviewed material included bibliographic and biomedical data, material safety data sheets and data requested and received from manufacturers. Results and recommendations: Cyanoacrylate adhesive closure appears to be an effective treatment for saphenous reflux with occlusion rates at 36 months of 90–95%. We recommend a maximum dose of 10 mL of cyanoacrylate per treatment session. Serious complications are rare, but significant. Hypersensitivity to acrylates is reported in 2.4% of the population and is an important absolute contraindication to cyanoacrylate adhesive closure.1 Post-procedural inflammatory reactions, including hypersensitivity-type phlebitis, occur in 10–20% of patients.2 In the long term, cyanoacrylate adhesive closure results in foreign-body granuloma formation within 2–12 months of the procedure. We recommend against the use of cyanoacrylate adhesive closure in patients with uncontrolled inflammatory, autoimmune or granulomatous disorders (e.g. sarcoidosis). Caution should be exercised in patients with significant active systemic disease or infection and alternative therapies such as thermal ablation and foam sclerotherapy should be considered. Conclusions: Cyanoacrylate adhesive closure appears to be an effective endovenous procedure, with short-term closure rates comparable to ETA and therefore greater efficacy than traditional surgery for treating superficial veins of the lower limbs. Ongoing data collection is required to establish the long-term safety

    Effectiveness of Ledipasvir-Sofosbuvir Combination in Patients With Hepatitis C Virus Infection and Factors Associated With Sustained Virologic Response

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    The combination of ledipasvir and sofosbuvir has been approved for treatment of genotype 1 hepatitis C virus (HCV) infection, including an 8-week regimen for treatment-naïve patients without cirrhosis and a baseline level of HCV RNA <6 million IU/mL. We analyzed data from a multicenter, prospective, observational study to determine real-world sustained virologic responses 12 weeks after treatment (SVR12) with regimens containing ledipasvir and sofosbuvir and identify factors associated with treatment failure

    Validity of self-reported weight, height, and body mass index among university students in Thailand: Implications for population studies of obesity in developing countries

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    <p>Abstract</p> <p>Background</p> <p>Large-scale epidemiological studies commonly use self-reported weights and heights to determine weight status. Validity of such self-reported data has been assessed primarily in Western populations in developed countries, although its use is widespread in developing countries. We examine the validity of obesity based on self-reported data in an Asian developing country, and derive improved obesity prevalence estimates using the "reduced BMI threshold" method.</p> <p>Methods</p> <p>Self-reported and measured heights and weights were obtained from 741 students attending an open university in Thailand (mean age 34 years). Receiver operator characteristic techniques were applied to derive "reduced BMI thresholds."</p> <p>Results</p> <p>Height was over-reported by a mean of 1.54 cm (SD 2.23) in men and 1.33 cm (1.84) in women. Weight was under-reported by 0.93 kg (3.47) in men and 0.62 kg (2.14) in women. Sensitivity and specificity for determining obesity (Thai BMI threshold 25 kg/m<sup>2</sup>) using self-reported data were 74.2% and 97.3%, respectively, for men and 71.9% and 100% for women. For men, reducing the BMI threshold to 24.5 kg/m<sup>2 </sup>increased the estimated obesity prevalence based on self-reports from 29.1% to 33.8% (true prevalence was 36.9%). For women, using a BMI threshold of 24.4 kg/m<sup>2</sup>, the improvement was from 12.0% to 15.9% (true prevalence 16.7%).</p> <p>Conclusion</p> <p>Young educated Thais under-report weight and over-report height in ways similar to their counterparts in developed countries. Simple adjustments to BMI thresholds will overcome these reporting biases for estimation of obesity prevalence. Our study suggests that self-reported weights and heights can provide economical and valid measures of weight status in high school-educated populations in developing countries.</p
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