Low chloride conductance myotonia - in vitro investigations on muscle stiffness and the warm-up phenomenon

Mutations in the chloride channel are causative for low chloride conductance (gCl-) myotonia. The phenotype shows muscle stiffness. By unknown mechanisms, this type of myotonia shows a reduction of stiffness after exercise, the so-called warm-up phenomenon. This study investigated myotonic stiffness and the warm-up phenomenon in vitro. Mechanographic registrations and resting membrane potential measurements were performed. Muscle samples from the animal model for low gCl-myotonia (ADR-mice) as well as pharmacologically induced myotonia were studied. The [K+]o and osmolarity were varied and pharmacological substances with potential clinical benefit were tested. Strong contraction triggers K+ accumulation in the small T-tubular compartment which is capable to initiate myotonic bursts, thereby prolonging muscle relaxation (myotonic stiffness). Further increase in K+ and the osmolarity led to a sustained membrane depolarization in a concentration-dependent manner. At 7 mM [K+]o the myotonic burst rate was suppressed more than 90 %. Repetitive contractions facilitated the warm-up phenomenon reflecting an enhanced stabilization of the membrane excitability. The big conductance calcium activated potassium channel (BK) agonist NS1608 led to a more severe relaxation deficit, but also to a more rapid onset of warm-up. Blocking the BK channel with paxilline prevented the onset of myotonia. Increasing gK+ via activation of the voltage gated potassium channels by retigabine enhanced the warm-up phenomenon. The sodium potassium chloride cotransporter type 1 inhibitor bumetanide prevented the depolarization and reversed the antimyotonic effect of high osmolarity. Blocking voltage gated Na+ channels with mexiletine and flecainide dose-dependently facilitated the warm-up phenomenon in ADR muscle. The findings have an important impact on dietary counseling and the use of drugs influencing gK+ and gNa+ to improve management and treatment of myotonic stiffness in low gCl-myotonia

Health risk assessment on musculoskeletal disorders among potato-chip processing workers.

Musculoskeletal disorders (MSDs) are the most common complaint among industrial workers. The potato-chip processing industry involves workers in repetitive activities leading to MSDs. This cross-sectional descriptive study aimed to assess MSDs health risk among potato-chip processing workers. It was conducted among 107 randomly sampled workers from a distribution like other groups exposed to similar ergonomics factors. A MSDs health-risk assessment produced a matrix of combined results based on a self-report questionnaire (5 levels) and an ergonomics risk assessment using RULA (4 levels). The self-reported MSDs questionnaire showed that workers had moderate to very high discomfort levels, i.e., 11.21% trunk, 9.35% lower limbs, 8.41% upper limbs and 4.66% for the neck. Ergonomic risks were found to be at a very high level, 77.57%, and high risk level, 19.63%. The combined matrix assessments showed that most workers were at moderate to very high MSDs risk, i.e., 43.92% trunk, 36.45% upper limbs, 32.71% lower limbs and 20.56% for the neck. This health risk matrix found a higher proportion of workers presenting with MSDs health risk compared with the musculoskeletal disorders self-assessment alone. Therefore, the MSDs risk matrix assessment could be useful for surveillance screening prior to implementing a risk-reduction program. Further, using ergonomics training programs and improving work stations for high-risk groups are also recommended based on the ergonomic and health risk assessments in this study

Situations of work-related diseases and injuries among agriculturists in the upper northeast regions of Thailand

The additional data for the article of "Situations of work-related diseases and injuries among agriculturists in the upper northeast regions of Thailand

Risk Assessment on Benzene Exposure among Gasoline Station Workers

Benzene is a human carcinogen presented in gasoline (1% by volume). It is also found in vehicle exhaust. The aim of this study was to assess the health risk of inhalation exposure to benzene among gasoline station workers. The ambient benzene concentration was measured by personal sampling from 150 gasoline station workers (137 fueling workers and 13 cashiers). Additional data of working characteristics were collected by interviews and on-site observations. All workers were non-smokers and passive smoking was limited. Risk assessment of inhalation exposure was determined using the United State Environmental Protection Agency (USEPA), and showed a high risk of adverse health effect (Hazard Quotients (HQ) >1) in 51.33% of workers. The cancer risk was increased from 1.35 × 10−8 to 1.52 × 10−4, and 70.67% of the workers had a lifetime cancer risk (>Inhalation Unit Risk (IUR): 2.2 × 10−6). A significantly higher risk was found in fueling workers compared to cashiers, and in workers at gasoline stations in inner-city zones (suburban and urban), compared to rural zones. All risk estimations were based upon a single measurement in an eight hour working period, which was assumed to be the average shift length for all working days in a year (250 days). The increased health risk suggests that there should be health surveillance for workers in order to protect them from exposure to benzene. In addition to benzene, the volatile organic compounds (VOCs) present in gasoline may influence health outcomes

Musculoskeletal Disorders among Agricultural Workers of Various Cultivation Activities in Upper Northeastern Thailand

Musculoskeletal disorders (MSDs) are the most significant work-related health conditions that are experienced by agricultural workers. This cross-sectional study has investigated MSDs among agriculturalists in upper northeastern Thailand. We assessed the types of MSDs, their severity, and their frequency. There were 889 cultivating agriculturalists from four provinces who participated in this study. The majority of the participants reported experiencing mild levels of MSDs (60.48%). Predominantly, the farmers who were working on cassava, vegetable, and sugarcane plantations reported experiencing the most severe MSDs in the knees/calves (22.40%). The rice plantation workers reported the largest number of MSDs complaints. The workers on rubber plantations and in sugarcane fields were more likely to feel knee/calf pain (OR = 1.59, 95% CI = 1.05–2.39) and lower limb pain (OR = 1.97, 95% CI = 1.35–2.89) than those who were working on rice and tobacco plantations. The individuals who were working on cassava, fruit, vegetable, and corn plantations were also more likely to report knee/calf pain (OR = 1.48, 95% CI = 1.01–2.17) and lower limb pain (OR = 1.97, 95% CI = 1.37–2.84) than those who were working on rice and tobacco plantations. The MSDs that were found among those working on agricultural activities affected many parts of their bodies. The ergonomic risk needs to be assessed in order to inform plantation workers of the implications in order to improve their health and well-being and to reduce the risks of MSDs

Musculoskeletal Disorders among Agricultural Workers of Various Cultivation Activities in Upper Northeastern Thailand

Musculoskeletal disorders (MSDs) are the most significant work-related health conditions that are experienced by agricultural workers. This cross-sectional study has investigated MSDs among agriculturalists in upper northeastern Thailand. We assessed the types of MSDs, their severity, and their frequency. There were 889 cultivating agriculturalists from four provinces who participated in this study. The majority of the participants reported experiencing mild levels of MSDs (60.48%). Predominantly, the farmers who were working on cassava, vegetable, and sugarcane plantations reported experiencing the most severe MSDs in the knees/calves (22.40%). The rice plantation workers reported the largest number of MSDs complaints. The workers on rubber plantations and in sugarcane fields were more likely to feel knee/calf pain (OR = 1.59, 95% CI = 1.05–2.39) and lower limb pain (OR = 1.97, 95% CI = 1.35–2.89) than those who were working on rice and tobacco plantations. The individuals who were working on cassava, fruit, vegetable, and corn plantations were also more likely to report knee/calf pain (OR = 1.48, 95% CI = 1.01–2.17) and lower limb pain (OR = 1.97, 95% CI = 1.37–2.84) than those who were working on rice and tobacco plantations. The MSDs that were found among those working on agricultural activities affected many parts of their bodies. The ergonomic risk needs to be assessed in order to inform plantation workers of the implications in order to improve their health and well-being and to reduce the risks of MSDs

The Burden of Work-Related Diseases and Injuries among Agriculturists: A Three-Year Retrospective Study in Thailand

This study investigated the incidence of work-related diseases and injuries among cultivating farmers in Thailand by conducting a three-year retrospective study with 207,465 farmers from Roi-Et province and 154,478 farmers from Udon Thani province. Health data were collected from the hospital information systems (HIS) of Roi-Et and Udon Thani provinces for a three-year period (2014–2016). We used the ICD-10 classification codes for diseases and injuries to analyse the incidence rates per 100,000 farmers. The number of cases that visited health centres were 53,794 in Udon Thani (34.82%) and 77,438 in Roi-Et (37.32%). The top five morbidity rates in Roi-Et and Udon Thani were work-related musculoskeletal disorders (WMSDs), followed by injuries, infectious disease, skin disease, and lung disease. The incidence of diseases and injuries found in Roi-Et, a more cultivating-agriculture-based province, was higher than that found in Udon Thani province. WMSDs were the greatest health concern in regard to cultivating activities. Infectious and lung diseases might have also been related to the cultivating activities, which warrants further studies. Our findings highlight an urgent need for targeted occupational health services, and health and safety measures among cultivating farmers in both provinces. Regular monitoring and surveillance programmes for cultivating farmers need to be in place, at the provincial level, to mitigate risk and protect the health and well-being of the farmers

The Burden of Work-Related Diseases and Injuries among Agriculturists: A Three-Year Retrospective Study in Thailand

This study investigated the incidence of work-related diseases and injuries among cultivating farmers in Thailand by conducting a three-year retrospective study with 207,465 farmers from Roi-Et province and 154,478 farmers from Udon Thani province. Health data were collected from the hospital information systems (HIS) of Roi-Et and Udon Thani provinces for a three-year period (2014–2016). We used the ICD-10 classification codes for diseases and injuries to analyse the incidence rates per 100,000 farmers. The number of cases that visited health centres were 53,794 in Udon Thani (34.82%) and 77,438 in Roi-Et (37.32%). The top five morbidity rates in Roi-Et and Udon Thani were work-related musculoskeletal disorders (WMSDs), followed by injuries, infectious disease, skin disease, and lung disease. The incidence of diseases and injuries found in Roi-Et, a more cultivating-agriculture-based province, was higher than that found in Udon Thani province. WMSDs were the greatest health concern in regard to cultivating activities. Infectious and lung diseases might have also been related to the cultivating activities, which warrants further studies. Our findings highlight an urgent need for targeted occupational health services, and health and safety measures among cultivating farmers in both provinces. Regular monitoring and surveillance programmes for cultivating farmers need to be in place, at the provincial level, to mitigate risk and protect the health and well-being of the farmers