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BackgroundTargeted screening for hepatitis C viral (HCV) infection is not yet widely executed in Belgium. When performed in people who use drugs (PWUD), it is mainly focused on those receiving opiate agonist therapy (OAT). We wanted to reach out to a population of difficult to reach PWUD not on centralized OAT, using non-invasive screening as a bridge to re-integration in medical care supported by facilitated referral to a specialist.MethodsThis was a prospective, multicenter cohort study in PWUD not enrolled in a centralized OAT program in a community-based facility in Limburg or OAT program in a community-based facility in Antwerp, Belgium, from October 2018 until October 2019. Two study teams recruited participants using an outreach method at 18 different locations. Participants were tested for HCV antibodies (Ab) by finger prick, and risk factors were assessed through a face-to-face questionnaire. Univariate analyses were used to assess the association between HCV Ab and each risk factor separately. A generalized linear mixed model was used to investigate the association between the different risk factors and HCV.ResultsIn total, 425 PWUD were reached with a mean age of 41.6 ± 10.8, and 78.8% (335/425) were men. HCV Ab prevalence was 14.8% (63/425). Fifty-six (88.9%) PWUD were referred, of whom 37 (66.1%) were linked to care and tested for HCV RNA. Twenty-nine (78.4%) had a chronic HCV infection. Treatment was initiated in 17 (58.6%) patients. The adjusted odds for HCV Ab were highest in those with unstable housing 6 months before inclusion (p p ConclusionsAn important part tested positive for HCV. Treatment could be started in more than half of the chronically infected referred and tested positive for HCV-RNA. Micro-elimination is necessary to achieve the World Health Organization goals by 2030. However, it remains crucial to screen and link a broader group of PWUD to care than to focus solely on those who inject drugs.Trial registration: clinicaltrials.gov NCT04363411, Registered 27 April 2020—Retrospectively registered.https://clinicaltrials.gov/ct2/show/NCT04363411?term=NCT04363411&draw=2&rank=1

Additional file 2. . A2. Univariate generalized linear mixed models to investigate the association between different risk factors and hepatitis C antibodies.

BackgroundPeople who inject drugs (PWID) account for the majority of new cases of hepatitis C virus (HCV) infection in Europe, however HCV testing and treatment for PWID remain suboptimal. With the advent of direct acting antivirals (DAAs) the World Health Organization (WHO) adopted a strategy to eliminate HCV as public health threat by 2030. To achieve this, key policies for PWID must be implemented and HCV continuum-of-care needs to be monitored. This study presents results of the first monitoring led by civil society that provide harm reduction services for PWID. MethodsIn 2019, harm reduction civil society organisations representing focal points of Correlation-European Harm Reduction Network in 36 European countries were invited to complete a 27-item online survey on four strategic fields: use/impact of guidelines on HCV testing and treatment for PWID, availability/functioning of continuum-of-care, changes compared to the previous year and, the role of harm reduction services and non-governmental organisations (NGOs) of PWID. A descriptive analysis of the responses was undertaken.ResultsThe response rate was 97.2%. Six countries reported having no guidelines on HCV treatment (17.1%). Twenty-three (65.7%) reported having treatment guidelines with specific measures for PWID; guidelines that impact on accessibility to HCV testing/treatment and improve access to harm reduction services in 95.6% and 86.3% of them, respectively. DAAs were available in 97.1% of countries; in 26.4% of them they were contraindicated for active drug users. HCV screening/confirmatory tests performed at harm reduction services/community centres, prisons and drug dependence clinics were reported from 80.0%/25.7%, 60.0%/48.6%, and 62.9%/34.3% of countries, respectively. Provision of DAAs at drug dependence clinics and prisons was reported from 34,3% and 42.9% of countries, respectively. Compared to the previous year, HCV awareness campaigns, testing and treatment on service providers’ own locations were reported to increase in 42.9%, 51.4% and 42.9% of countries, respectively. NGOs of PWID conducted awareness campaigns on HCV interventions in 68.9% of countries, and 25.7% of countries had no such support. ConclusionFurther improvements of continuum-of-care interventions for PWID are needed, which could be achieved by including harm reduction and PWID organisations in strategic planning of testing and treatment and in efforts to monitor progress towards WHO 2030 elimination goal.

AIM: In Western European populations, about 18% of all individuals have a complete deficiency of the alpha-actinin-3 protein owing to homozygosity for a stop codon mutation (R577X) in the ACTN3 gene. Actn3(-/-) knock-out mice show increased activity of multiple enzymes in the aerobic metabolic pathway in fast muscle fibres. Whether this observation is also present in human XX genotype carriers compared to RR carriers has not been studied in a fibre-type-specific approach in humans. The purpose of this study was therefore to compare fibre-type-specific oxidative enzyme activity in humans with a different ACTN3 R577X genotype. METHODS: Vastus lateralis muscle biopsy samples of 17 XX and 16 RR subjects were used to measure markers of oxidative capacity [cytochrome c oxidase (CYTOX) and succinate dehydrogenase (SDH)] in a fibre-type-specific assay using enzyme histochemistry. RESULTS: Cytochrome c oxidase staining showed no significant genotype group differences in type I or type II muscle fibres. Also, we found no significant differences in SDH staining of fast fibres comparing XX and RR carriers. CONCLUSION: In conclusion, the increase in oxidative enzyme activity of fast muscle fibres, as reported in an Actn3(-/-) knock-out mouse, was not observed in our human samples. Known differences in metabolic characteristics of muscle fibres in rodents compared to humans may in part explain this discrepancy in findings.

Muscle strength is important in functional activities of daily living and the prevention of common pathologies. We describe the two-staged fine mapping of a previously identified linkage peak for knee strength on chr12q12-14. First, 209 tagSNPs in/around 74 prioritized genes were genotyped in 500 Caucasian brothers from the Leuven Genes for Muscular Strength study (LGfMS). Combined linkage and family-based association analyses identified activin receptor 1B (ACVR1B) and inhibin beta C (INHBC), part of the transforming growth factor beta pathway regulating myostatin - a negative regulator of muscle mass - signaling, for follow-up. Second, 33 SNPs, selected in these genes based on their likelihood to functionally affect gene expression/function, were genotyped in an extended sample of 536 LGfMS siblings. Strong associations between ACVR1B genotypes and knee muscle strength (P-values up to 0.00002) were present. Of particular interest was the association with rs2854464, located in a putative miR-24-binding site, as miR-24 was implicated in the inhibition of skeletal muscle differentiation. Rs2854464 AA individuals were similar to 2% stronger than G-allele carriers. The strength increasing effect of the A-allele was also observed in an independent replication sample (n=266) selected from the Baltimore Longitudinal Study of Aging and a Flemish Policy Research Centre Sport, Physical Activity and Health study. However, no genotype-related difference in ACVR1B mRNA expression in quadriceps muscle was observed. In conclusion, we applied a two-stage fine mapping approach, and are the first to identify and partially replicate genetic variants in the ACVR1B gene that account for genetic variation in human muscle strength. European Journal of Human Genetics (2011) 19, 208-215; doi:10.1038/ejhg.2010.173; published online 10 November 2010

The ACTN3 gene encodes for the alpha-actinin-3 protein, which has an important structural function in the Z line of the sarcomere in fast muscle fibers. A premature stop codon (R577X) polymorphism in the ACTN3 gene causes a complete loss of the protein in XX homozygotes. This study investigates a possible role for the alpha-actinin-3 protein in protecting the fast fiber from eccentric damage and studies repair mechanisms after a single eccentric exercise bout. Nineteen healthy young men (10 XX, 9 RR) performed 4 series of 20 maximal eccentric knee extensions with both legs. Blood (creatine kinase; CK) and muscle biopsy samples were taken to study differential expression of several anabolic (MyoD1, myogenin, MRF4, Myf5, IGF-1), catabolic (myostatin, MAFbx, and MURF-1), and contraction-induced muscle damage marker genes [cysteine- and glycine-rich protein 3 (CSRP3), CARP, HSP70, and IL-6] as well as a calcineurin signaling pathway marker (RCAN1). Baseline mRNA content of CSRP3 and MyoD1 was 49 + or - 12 and 67 + or - 25% higher in the XX compared with the RR group (P = 0.01-0.045). However, satellite cell number was not different between XX and RR individuals. After eccentric exercise, XX individuals tended to have higher serum CK activity (P = 0.10) and had higher pain scores than RR individuals. However, CSRP3 (P = 0.058) and MyoD1 (P = 0.08) mRNA expression tended to be higher after training in RR individuals compared with XX alpha-actinin-3-deficient subjects. This study suggests a protective role of alpha-actinin-3 protein in muscle damage after eccentric training and an improved stress-sensor signaling, although effects are small.

Repeated, intense use of muscles leads to a decline in performance known as muscle fatigue. Resistance to muscle fatigue depends on age, sex, muscle fiber type, activation by the nervous system and training. Heritability of muscle strength phenotypes ranges between 31% and 78%, although little is known about heritability of muscle fatigue. A first aim of this study was to estimate the heritability for fatigue resistance after a short bout of intense exercise of the knee musculature. The main purpose was to identify chromosomal regions linked to muscle fatigue applying genome-wide linkage analyses. A selection of 283 informative male siblings (17-36 years old), belonging to 105 families, was used to conduct a genome-wide SNP-based multipoint linkage analysis. Heritabilities for resistance to muscle fatigue ranged from 21% to 54%. The strongest linkage signal was found at 19q13.11 (LOD=2.158; P 1.5 were found (1p31.3, 3q29, 8p22, 11q25 and 19q12). When replicated in an independent sample, these results warrant further fine mapping studies aiming to detect genes that underlie variation in muscle fatigue.

Fine mapping of linkage peaks is one of the great challenges facing researchers who try to identify genes and genetic variants responsible for the variation in a certain trait or complex disease. Once the trait is linked to a certain chromosomal region, most studies use a candidate gene approach followed by a selection of polymorphisms within these genes, either based on their possibility to be functional, or based on the linkage disequilibrium between adjacent markers. For both candidate gene selection and SNP selection, several approaches have been described, and different software tools are available. However, mastering all these information sources and choosing between the different approaches can be difficult and time-consuming. Therefore, this article lists several of these in silico procedures, and the authors describe an empirical two-step fine mapping approach, in which candidate genes are prioritized using a bioinformatics approach (ENDEAVOUR), and the top genes are chosen for further SNP selection with a linkage disequilibrium based method (Tagger). The authors present the different actions that were applied within this approach on two previously identified linkage regions for muscle strength. This resulted in the selection of 331 polymorphisms located in 112 different candidate genes out of an initial set of 23,300 SNPs.

Peroxisome proliferator-activated receptor alpha (PPARα), a ligand-dependent transcription factor, regulates fatty acid metabolism in heart and skeletal muscle. The intron 7 G/C polymorphism (rs4253778) has been associated with athletic performance. The rare C-allele was predominant in power athletes, whereas the G-allele was more frequent in endurance athletes. In the present study, we investigated the association between this polymorphism and strength characteristics in nonathletic, healthy young adults (n = 500; age 24.2 ± 4.4 years). Knee torque was measured during concentric knee flexion and extension movements at 60°/s, 120°/s, and 240°/s during 3, 25, and 5 repetitions, respectively. Also, resistance to muscle fatigue (i.e. work last 20% repetitions/work first 20% repetitions *100) was calculated. Differences in knee strength phenotypes between GG homozygous individuals and C-allele carriers were analyzed. The polymorphism did not influence the ability to produce isometric or dynamic knee flexor or extensor peak torque during static or dynamic conditions in this population (0.23

In Western European populations, about 18% of all individuals have a complete deficiency of the alpha-actinin-3 protein owing to homozygosity for a stop codon mutation (R577X) in the ACTN3 gene. Actn3(-/-) knock-out mice show increased activity of multiple enzymes in the aerobic metabolic pathway in fast muscle fibres. Whether this observation is also present in human XX genotype carriers compared to RR carriers has not been studied in a fibre-type-specific approach in humans. The purpose of this study was therefore to compare fibre-type-specific oxidative enzyme activity in humans with a different ACTN3 R577X genotype.Vastus lateralis muscle biopsy samples of 17 XX and 16 RR subjects were used to measure markers of oxidative capacity [cytochrome c oxidase (CYTOX) and succinate dehydrogenase (SDH)] in a fibre-type-specific assay using enzyme histochemistry.Cytochrome c oxidase staining showed no significant genotype group differences in type I or type II muscle fibres. Also, we found no significant differences in SDH staining of fast fibres comparing XX and RR carriers.In conclusion, the increase in oxidative enzyme activity of fast muscle fibres, as reported in an Actn3(-/-) knock-out mouse, was not observed in our human samples. Known differences in metabolic characteristics of muscle fibres in rodents compared to humans may in part explain this discrepancy in findings.

Peroxisome proliferator-activated receptor alpha (PPARα), a ligand-dependent transcription factor, regulates fatty acid metabolism in heart and skeletal muscle. The intron 7 G/C polymorphism (rs4253778) has been associated with athletic performance. The rare C-allele was predominant in power athletes, whereas the G-allele was more frequent in endurance athletes. In the present study, we investigated the association between this polymorphism and strength characteristics in nonathletic, healthy young adults (n = 500; age 24.2 ± 4.4 years). Knee torque was measured during concentric knee flexion and extension movements at 60°/s, 120°/s, and 240°/s during 3, 25, and 5 repetitions, respectively. Also, resistance to muscle fatigue (i.e. work last 20% repetitions/work first 20% repetitions *100) was calculated. Differences in knee strength phenotypes between GG homozygous individuals and C-allele carriers were analyzed. The polymorphism did not influence the ability to produce isometric or dynamic knee flexor or extensor peak torque during static or dynamic conditions in this population (0.23 P 0.95). Similar results were found for the endurance ratio, a measure for resistance to muscle fatigue. In conclusion, the PPARα intron 7 G/C polymorphism does not seem to influence strength characteristics in a nonathletic population.

The torque-velocity relationship is known to be affected by ageing, decreasing its protective role in the prevention of falls. Interindividual variability in this torque-velocity relationship is partly determined by genetic factors (h2: 44–67%). As a first attempt, this genome-wide linkage study aimed to identify chromosomal regions linked to the torque-velocity relationship of the knee flexors and extensors. A selection of 283 informative male siblings (17–36 yr), belonging to 105 families, was used to conduct a genome-wide SNP-based (Illumina Linkage IVb panel) multipoint linkage analysis for the torque-velocity relationship of the knee flexors and extensors. The strongest evidence for linkage was found at 15q23 for the torque-velocity slope of the knee extensors (TVSE). Other interesting linkage regions with LOD scores >2 were found at 7p12.3 [logarithm of the odds ratio (LOD) = 2.03, P = 0.0011] for the torque-velocity ratio of the knee flexors (TVRF), at 2q14.3 (LOD = 2.25, P = 0.0006) for TVSE, and at 4p14 and 18q23 for the torque-velocity ratio of the knee extensors TVRE (LOD = 2.23 and 2.08; P = 0.0007 and 0.001, respectively). We conclude that many small contributing genes are involved in causing variation in the torque-velocity relationship of the knee flexor and extensor muscles. Several earlier reported candidate genes for muscle strength and muscle mass and new candidates are harbored within or in close vicinity of the linkage regions reported in the present study.

The purpose of the present study was to examine genetic and environmental contributions to individual differences in maximal isometric, concentric and eccentric muscle strength and muscle cross-sectional area (MCSA) of the elbow flexors. A generality versus specificity hypothesis was explored to test whether the 4 strength variables share a genetic component or common factors in the environment or whether the genetic/environmental factors are specific for each strength variable. The 4 variables under study were measured in 25 monozygotic and 16 dizygotic male Caucasian twin pairs (22.4 ± 3.7 years). The multivariate genetic analyses showed that all 4 variables shared a genetic and environmental component, which accounted for 43% and 6% in MCSA (h2= 81%), 47% and 20% in eccentric (h2= 65%), 58% and 4% in isometric (h2= 70%) and 32% and 1% in concentric strength (h2= 32%) respectively. The remaining variation was accounted for by contraction type specific and muscle cross-sectional area specific genetic and environmental effects, which accounted for 38% and 14% in MCSA, 18% and 15% in eccentric, 12% and 26% in isometric and 0% and 67% in concentric strength respectively. This exploratory multivariate study suggests shared pleiotropic gene action for MCSA, eccentric, isometric and concentric strength, with a moderate to high genetic contribution to the variability of these characteristics.

Genotypic associations between polymorphisms in the ciliary neurotrophic factor (CNTF) and CNTF receptor (CNTFR) genes and muscular strength phenotypes in 154 middle-aged men (45-49 yr) and 138 women (38-44 yr) and 99 older men (60-78 yr) and 102 older women (60-80 yr) were tested to validate earlier association studies. Allelic interaction effects were hypothesized between alleles of CNTF and CNTFR. We performed analysis of covariance with age, height, and fat-free mass (FFM) as covariates. FFM was anthropometrically estimated by the equation of Durnin-Womersley. Isometric, concentric, and eccentric torques for the knee flexors (KF) and extensors (KE) were measured using Biodex dynamometry. In the older male group, T-allele carriers of the C-1703T polymorphism in CNTFR performed significantly better on all noncorrected KF torques, whereas only noncorrected KE isometric torque at 120 degrees and concentric torque at 240 degrees/s were higher than the C/C homozygotes (P0.05). When age, height, and FFM were used as covariates, T-allele carriers performed only better on KE and KF isometric torque at 120 degrees (P0.05). Concentric KF torque at 180 degrees/s was lower in middle-aged female A-allele carriers compared with the T/T subjects for the T1069A polymorphism in CNTFR. After correction for age, height, and FFM, middle-aged female A-allele carriers exhibited lower values on all concentric KF strength measures and isometric torque at 120 degrees . There was a lack of association with the CNTF G-6A polymorphism in men, with inconclusive results for a limited number of phenotypes in women. No significant CNTF/CNTFR allele interaction effects were found. Results indicate that CNTFR C-1703T and T1069A polymorphisms are significantly associated with muscle strength in humans.

Vitamin D receptor (VDR) polymorphisms have been associated with fracture risk and muscle strength, although evidence for the latter is limited and conflicting.BsmI, TaqI and FokI VDR polymorphisms were genotyped in 253 men (54.9 +/- 10.2 yr) and 240 women (41.5 +/- 13.2 yr). Haplotypes were constructed for BsmI and TaqI. Handgrip, isometric (at 60 degrees , 120 degrees and 180 degrees joint angle) and eccentric torques (60 degrees /s) of knee extension and flexion were analysed using AN(C)OVA. Torque-velocity curves were constructed for concentric torques at 60 degrees /s, 180 degrees /s and 240 degrees /s and analysed using multivariate AN(C)OVA. Age, height and fat-free mass were included as covariates.Quadriceps isometric and concentric strength were higher in female f/f homozygotes compared to F allele carriers. Adjustment for confounding factors rendered results for quadriceps isometric strength at 120 degrees non-significant. No significant association was found with BsmI-TaqI haplotype in women. In contrast, male Bt/Bt homozygotes had higher isometric quadriceps strength at 150 degrees and higher concentric quadriceps strength than bT allele carriers without and with adjustment for confounding factors. No association was observed with FokI in men. In both genders, no interaction effect was present between BsmI-TaqI haplotype and FokI.Different VDR gene polymorphisms are associated with quadriceps strength in men and women.

The Arabidopsis thaliana mutant esa1 was previously shown to exhibit enhanced susceptibility to the necrotrophic fungal pathogens Alternaria brassicicola , Botrytis cinerea and Plectosphaerella cucumerina . In this work, we tried to elaborate on this susceptibility by investigating whether the esa1 phenotype can be extended to Fusarium species, a genus that includes several economically relevant pathogens. We show that the esa1 mutant exhibits increased susceptibility to several Fusarium species, including Fusarium oxysporum f. sp. matthiolae , F. solani , and F. culmorum . Furthermore, we show that the causal agent of the Panama disease on banana, F. oxysporum f. sp. cubense , a pathogen for which wild-type A. thaliana shows non-host resistance, causes enhanced lesion formation on esa1 as compared to wild-type plants, suggesting that esa1 is more sensitive to F. oxysporum f. sp. cubense . In addition, we were able to show that the A. thaliana wild-type resistance phenotype towards the latter pathogen can be partially restored by expression of the pathogenesis-related proteins PR1 or PR5 from tobacco in esa1 , suggesting that PR1 and/or PR5 expression may be useful traits to obtain enhanced resistance to F. oxysporum f. sp. cubense in banana. As such, esa1 proves to be an ideal model system for research on the plant's defense response against fungal pathogens in general and Fusarium species in particular.

We describe an approach to the multi-robot task allocation (MRTA) problem in which a group of robots must perform tasks that arise continuously, at arbitrary locations across a large space. A dynamic scheduling algorithm is derived in which proposed plans are evaluated using a combination of short-term lookahead and a value function acquired by reinforcement learning. We demonstrate that this dynamic scheduler can learn not only to allocate robots to tasks efficiently, but also to position the robots appropriately in readiness for new tasks (tactical awareness), and conserve resources over the long run (strategic awareness).