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1.
Toxics ; 12(5)2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38787116

RESUMO

Sprayers' exposure to glyphosate was analyzed through detection of its biomarker in spot urine biological monitoring, and the health risk was assessed using the biomatrix model. Urine samples were collected from 15 sprayers after spraying, and the glyphosate concentration was determined by using the DLLME-HPLC method with a UV detector. The calibration curve for glyphosate was linear in the range of 0.4-100 µg/L, while the limits of detection and quantification were 0.1 µg/L and 0.4 µg/L, respectively. The human health risk was estimated using the hazard quotient (HQ) and the biomatrix of risk assessment. The internal dose ranged from 0.0001 to 0.0021 mg/kg b.w./day. The non-cancer HQ showed no potential health risk concerns (HQ < 1). The biomatrix of health risk assessment, based on urinary glyphosate concentration, exhibited a strong correlation with the health risk matrix model. This correlation was determined by considering the likelihood of exposure, calculated from the quantity of glyphosate used and the usage of personal protective equipment (r = 0.854, p < 0.001). Although low risk was observed in sprayers, proper PPE use and the application of more knowledge are required. The simplified health risk assessment can be used for easy self-assessment of risk in preventive action regarding health risk awareness among sprayers.

2.
PLoS One ; 18(4): e0285304, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37104372

RESUMO

[This corrects the article DOI: 10.1371/journal.pone.0277548.].

3.
Artigo em Inglês | MEDLINE | ID: mdl-35897345

RESUMO

Despite the fact that several cases of unsafe pesticide use among farmers in different parts of Africa have been documented, there is limited evidence regarding which specific interventions are effective in reducing pesticide exposure and associated risks to human health and ecology. The overall goal of the African Pesticide Intervention Project (APsent) study is to better understand ongoing research and public health activities related to interventions in Africa through the implementation of suitable target-specific situations or use contexts. A systematic review of the scientific literature on pesticide intervention studies with a focus on Africa was conducted. This was followed by a qualitative survey among stakeholders involved in pesticide research or management in the African region to learn about barriers to and promoters of successful interventions. The project was concluded with an international workshop in November 2021, where a broad range of topics relevant to occupational and environmental health risks were discussed such as acute poisoning, street pesticides, switching to alternatives, or disposal of empty pesticide containers. Key areas of improvement identified were training on pesticide usage techniques, research on the effectiveness of interventions targeted at exposure reduction and/or behavioral changes, awareness raising, implementation of adequate policies, and enforcement of regulations and processes.


Assuntos
Exposição Ocupacional , Praguicidas , Agricultura , Fazendeiros , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Exposição Ocupacional/prevenção & controle
4.
F1000Res ; 11: 145, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37224323

RESUMO

Background: Agriculturists exposed to health hazards are affected by increased occupational disease. This retrospective study aimed to investigate situations of work-related diseases and injuries among agriculturists in upper northeast Thailand. Methods: The secondary data of international classification of diseases 10 th revision (ICD-10) case reports of occupational disease among farmers, from the database of the Health Data Center (HDC), were used. The registered farmers data was collected as a dataset from the provincial agricultural office and the data of ICD-10 code utilised from the hospital information system (HIS) of healthcare services in Udon Thani and Roi-Et provinces, which was extracted for cases of work-related diseases and injuries of registered agriculturists. The annual morbidity rate of occupational diseases was analysed and presented at a rate per 100,000 farmers. Results: Among farmers in the HDC database, lung disease, which was not reported as occupational disease of the HDC database, was the highest ranking of all diseases, followed by work-related musculoskeletal disorders (WMSDs), noise- and heat-related diseases, and pesticide toxicity, respectively, while the injury rate was as high as that of WMSDs. Those morbidity rates of Roi-Et and Udon Thani provinces were representative of the morbidity ranking of diseases of the nation and had increasing trends from 2014 to 2016. The number of farmers in the HDC database did not consistently reflect the number of registered farmers in the agricultural database. Conclusions: Situations of work-related diseases and injuries discovered among registered farmers reflect the health problems of Thai agriculturists, and the underestimation in the reported disease rate in the health database is explained by big data analysis, which showed that work-related cases with an identifying code of Y96 had rarely been reported among agriculturists. Therefore, Thai agriculturists should be supported in registration with occupational diseases and injuries surveillance as holistic healthcare.


Assuntos
Agricultura , Doenças Profissionais , Humanos , Estudos Retrospectivos , Tailândia/epidemiologia , Análise de Dados , Doenças Profissionais/epidemiologia
5.
J Occup Health ; 63(1): e12307, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34957641

RESUMO

OBJECTIVE: This study assessed the health risk of benzene exposure among Thai gasoline station workers through biomarker detection and experience of adverse symptoms. METHODS: Trans, trans-muconic acid (tt-MA) metabolites of benzene were analyzed from spot urine sampled among gasoline station workers after shift work using HPLC-UV. Air benzene monitoring was done with an active sampler connected to a charcoal sorbent tube, and analyzed by GC-FID. The health risk was calculated by using the biomatrix of the likelihood of benzene exposure and the severity of adverse symptoms. RESULTS: The tt-MA concentration, among 235 workers, ranged from less than 10-2159 µg/g Cr, which corresponded to the air benzene concentration range of <0.1 to 65.8 ppb. In total, 32.3% of workers had a higher than acceptable risk level and there was a significant association between gasoline station work zones and the likelihood of benzene exposure as well as the health risk of workers. The health risk levels estimated from the biomarker monitoring were consistent with the risk matrix of air benzene monitoring. CONCLUSION: This tt-MA biomarker monitoring and biomatrix of health risk assessment is suggested as useful for health surveillance of gasoline station workers exposed to benzene.


Assuntos
Poluentes Ocupacionais do Ar/análise , Benzeno/toxicidade , Gasolina/toxicidade , Exposição Ocupacional/efeitos adversos , Medição de Risco/métodos , Adolescente , Adulto , Benzeno/análise , Biomarcadores/urina , Monitoramento Ambiental , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Sórbico/análogos & derivados , Ácido Sórbico/toxicidade , Tailândia , Adulto Jovem
6.
Artigo em Inglês | MEDLINE | ID: mdl-34639318

RESUMO

This cross-sectional study examined the risk factors affecting adverse health effects from benzene exposure among gasoline station workers in Khon Kean province, Thailand. An interview questionnaire of adverse symptoms relating to benzene toxicity was administered to 151 workers. Area samplings for benzene concentration and spot urine for tt-muconic acid (tt-MA), a biomarker of benzene exposure, were collected. The factors associated with adverse symptoms were analysed by using multiple logistic regression. It was found that these symptoms mostly affected fuelling workers (77.5%), and the detected air benzene reached an action level or higher than 50% of NIOSH REL (>50 ppb). The top five adverse symptoms, i.e., fatigue, headache, dizziness, nasal congestion, and runny nose, were reported among workers exposed to benzene. More specific symptoms of benzene toxicity were chest pain, bleeding/epistaxis, and anaemia. The detected tt-MA of workers was 506.7 ug/g Cr (IQR), which was a value above the BEI and higher than that of asymptomatic workers. Risk factors significantly associated with adverse symptoms, included having no safety training experience (ORadj = 5.22; 95% CI: 2.16-12.58) and eating during work hours (ORadj = 16.08; 95% CI: 1.96-131.74). This study urges the tightening of health and safety standards at gasoline stations to include training and eating restrictions while working in hazardous areas.


Assuntos
Poluentes Ocupacionais do Ar , Exposição Ocupacional , Poluentes Ocupacionais do Ar/análise , Benzeno/análise , Benzeno/toxicidade , Estudos Transversais , Gasolina , Humanos , National Institute for Occupational Safety and Health, U.S. , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , Estados Unidos
7.
PLoS One ; 16(4): e0249913, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33857202

RESUMO

Vaporization of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds pollutes the air and causes health hazards at gasoline stations. This study revealed the risk of BTEX exposure according to the hazardous area classification at gasoline stations. The risk assessment of gasoline workers from a representative group of 47 stations, which followed the United States Environmental Protection Agency-IRIS method of assessing BTEX exposure, was expressed as the hazard index (HI). A result of matrix multipliers of the hazardous exposure index and fire possibility from flammable gas classified hazardous area-I and area-II at the fuel dispensers. BTEX concentrations were actively sampled in ambient air and a flammable gas detector was used to measure the flammability level. Results showed that the BTEX concentrations from ambient air monitoring were in the range of 0.1-136.9, 8.1-406.0, 0.8-24.1 and 0.4-105.5 ppb for benzene, toluene, ethylbenzene, and xylene, respectively, which exceeded the NIOSH exposure limit of 100 ppb of benzene concentration. The risk assessment indicated that five stations reached an unacceptable risk of worker exposure to BTEX (HI>1), which correlated with the numbers of gasoline dispensers and daily gasoline sold. The risk matrix classified hazardous area-I at 4 meters and hazardous area-II at 4-8 meters in radius around the fuel dispensers. This study revealed the hazardous areas at gasoline stations and suggests that entrepreneurs must strictly control the safety operation practice of workers, install vapor recovery systems on dispenser nozzles to control BTEX vaporization and keep the hazardous areas clear of fire ignition sources within an eight-meter radius of the dispensers.


Assuntos
Poluentes Ocupacionais do Ar/análise , Gasolina , Substâncias Perigosas/análise , Exposição por Inalação/estatística & dados numéricos , Veículos Automotores , Exposição Ocupacional/estatística & dados numéricos , Gestão da Segurança/estatística & dados numéricos , Derivados de Benzeno/análise , Humanos , National Institute for Occupational Safety and Health, U.S./normas , Medição de Risco , Estados Unidos , United States Environmental Protection Agency/normas
8.
Int J Occup Saf Ergon ; 27(4): 1215-1221, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31855132

RESUMO

This prospective cohort study investigated the incidence of lower back pain (LBP) and the risk factors for LBP among university-based office workers. Participants were 159 office workers in one Thailand university who met the inclusion criteria of the cohort group. Data were collected using a follow-up interview questionnaire and measurements of physical fitness and lighting intensity. Results showed that the incidence of LBP during 12-month follow-up was 83.0%. Physical fitness tests showed that the back, leg and hand grip strengths were significantly lower in LBP cases than in non-cases. Multiple logistic regression analysis indicated that the risk factors associated with LBP were body mass index ≤ 25 (adjusted relative risk [RRadj] = 3.49, 95% confidence interval [CI] [1.27, 9.55]), poor back-pain preventive behavior (RRadj = 3.44, 95% CI [1.08, 10.98]) and inappropriate workstation width (RRadj = 5.72, 95% CI [1.44, 22.70]). In conclusion, most workstations (91.8%) had a lighting intensity lower than the standard requirement (400-500 lx). The results indicate the nature of hazards affecting LBP in office workers in the academic workplace. In order to prevent LBP in this group of office workers, ergonomics education and the better design of workspace, improved lighting and greater emphasis on the physical fitness of staff are needed.


Assuntos
Dor Lombar , Doenças Profissionais , Força da Mão , Humanos , Incidência , Dor Lombar/epidemiologia , Doenças Profissionais/epidemiologia , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários
9.
Front Physiol ; 11: 533946, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33329012

RESUMO

Reduced Cl- conductance causes inhibited muscle relaxation after forceful voluntary contraction due to muscle membrane hyperexcitability. This represents the pathomechanism of myotonia congenita. Due to the prevailing data suggesting that an increased potassium level is a main contributor, we studied the effect of a modulator of a big conductance Ca2+- and voltage-activated K+ channels (BK) modulator on contraction and relaxation of slow- and high-twitch muscle specimen before and after the pharmacological induction of myotonia. Human and murine muscle specimens (wild-type and BK-/-) were exposed to anthracene-9-carboxylic acid (9-AC) to inhibit CLC-1 chloride channels and to induce myotonia in-vitro. Functional effects of BK-channel activation and blockade were investigated by exposing slow-twitch (soleus) and fast-twitch (extensor digitorum longus) murine muscle specimens or human musculus vastus lateralis to an activator (NS1608) and a blocker (Paxilline), respectively. Muscle-twitch force and relaxation times (T90/10) were monitored. Compared to wild type, fast-twitch muscle specimen of BK-/- mice resulted in a significantly decreased T90/10 in presence of 9-AC. Paxilline significantly shortened T90/10 of murine slow- and fast-twitch muscles as well as human vastus lateralis muscle. Moreover, twitch force was significantly reduced after application of Paxilline in myotonic muscle. NS1608 had opposite effects to Paxilline and aggravated the onset of myotonic activity by prolongation of T90/10. The currently used standard therapy for myotonia is, in some individuals, not very effective. This in vitro study demonstrated that a BK channel blocker lowers myotonic stiffness and thus highlights its potential therapeutic option in myotonia congenital (MC).

10.
Pflugers Arch ; 472(10): 1533, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32885305

RESUMO

The original article contains an error during online publication. Table 2 was included during production round and now deleted. The Original article has been corrected.

11.
Pflugers Arch ; 472(10): 1481-1494, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32748018

RESUMO

In myotonia, reduced Cl- conductance of the mutated ClC-1 channels causes hindered muscle relaxation after forceful voluntary contraction due to muscle membrane hyperexcitability. Repetitive contraction temporarily decreases myotonia, a phenomena called "warm up." The underlying mechanism for the reduction of hyperexcitability in warm-up is currently unknown. Since potassium displacement is known to reduce excitability in, for example, muscle fatigue, we characterized the role of potassium in native myotonia congenita (MC) muscle. Muscle specimens of ADR mice (an animal model for low gCl- conductance myotonia) were exposed to increasing K+ concentrations. To characterize functional effects of potassium ion current, the muscle of ADR mice was exposed to agonists and antagonists of the big conductance Ca2+-activated K+ channel (BK) and the voltage-gated Kv7 channel. Effects were monitored by functional force and membrane potential measurements. By increasing [K+]0 to 5 mM, the warm-up phenomena started earlier and at [K+]0 7 mM only weak myotonia was detected. The increase of [K+]0 caused a sustained membrane depolarization accompanied with a reduction of myotonic bursts in ADR mice. Retigabine, a Kv7.2-Kv7.5 activator, dose-dependently reduced relaxation deficit of ADR myotonic muscle contraction and promoted the warm-up phenomena. In vitro results of this study suggest that increasing potassium conductivity via activation of voltage-gated potassium channels enhanced the warm-up phenomena, thereby offering a potential therapeutic treatment option for myotonia congenita.


Assuntos
Canais de Cloreto/genética , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Miotonia Congênita/metabolismo , Potássio/metabolismo , Animais , Cloretos/metabolismo , Canais de Potássio KCNQ/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/agonistas , Canais de Potássio Ativados por Cálcio de Condutância Alta/antagonistas & inibidores , Masculino , Potenciais da Membrana , Camundongos , Contração Muscular , Mutação , Miotonia Congênita/genética , Miotonia Congênita/fisiopatologia , Bloqueadores dos Canais de Potássio/farmacologia
12.
J Occup Health ; 62(1): e12137, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32716560

RESUMO

OBJECTIVE: This cross-sectional study aimed to assess fire risk in fire hazardous zones (FHZ) at the dispenser areas of gasoline stations. METHODS: There were 47 stations chosen for fire risk assessment and two zones around the dispenser area of each station were assessed. The assessments were carried out by applying the matrix (3 × 4) of fire risk assessment by multipliers of opportunities level of hazard occurrence and the subsequent severity of the incident. RESULTS: Across the 47 gasoline stations studied, there was an average of 23 ± 12 nozzles and none had vapor recovery systems (VRS) on dispenser nozzles. The average daily amount of gasoline sold was 3382 L. Each gasoline station had an average of 10 ± 5 workers/station; they all worked within a 1.5 meter radius of the dispenser (FHZ-I); and they used cellphones >4 hours/day. The average level of flammable gas was in the range 1.3%-7.4% LEL-UEL (6.2% ± 5.2%). The fire risk was found to be an intolerable risk in FHZ-I at 40 stations (85.1%) and FHZ-II at 10 stations (21.3%). A total of 18 stations were ranked as having a substantial risk, whereas 19 stations also had a moderate risk in FHZ-II; those levels correlated with the station locations and the quantity of fuel sold. CONCLUSION: It suggests that high risk must be controlled by using preventive and safety actions: eliminating fire ignition sources, such as by cellphone prohibition, and inspection of electrostatic discharges, engineering control with grounding when refuelling, signposting of hazardous zones, and VRS installation on dispenser nozzles.


Assuntos
Poluentes Ocupacionais do Ar/análise , Monitoramento Ambiental , Incêndios , Gasolina/análise , Exposição Ocupacional/análise , Estudos Transversais , Humanos , Medição de Risco
13.
Indian J Occup Environ Med ; 24(3): 183-187, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33746433

RESUMO

AIMS: Electronics industry workers might have increased the risk of low back pain (LPB). This cohort study aimed to investigate LBP incidence and provide a baseline of ergonomic factors and workers' characteristics associated with LBP. METHODS: A six-month monitoring phase was designed using 196 electronic workers to identify LBP incidence. Baseline data were collected for ergonomic risk by RULA and lighting intensity measurement. Personal factors and work stress were surveyed by job content questionnaires (JCQ). RESULTS: Ergonomic risk related to sitting posture was indicated at inspection with lamp (66.7%; change needed). High risk was shown among standing workers at punching and E-check processes. The lighting intensity did not meet the recommended standard in the arm range zone 2 of inspection and E-check stations. Dissatisfaction was reported due to work stress, workload, work rhythm, and job control. The six-month LBP incidence was 52.5%. Work experience less than three years (RR = 1.41; 95% CI: 1.031.90) and chronic diseases (RR = 1.41; 95% CI: 1.091.82) were significantly correlated with LBP incidence. CONCLUSIONS: Ergonomic and lighting conditions at E-check and inspection should be improved, and the promotion of short break exercise during shiftwork period is suggested. LBP should be closely surveilled in workers who had less job experience and underlying diseases.

14.
PLoS One ; 14(12): e0224980, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31794549

RESUMO

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.


Assuntos
Ergonomia , Indústria Manufatureira , Doenças Musculoesqueléticas/epidemiologia , Doenças Profissionais/epidemiologia , Adulto , Estudos Transversais , Feminino , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Programas de Rastreamento , Doenças Musculoesqueléticas/fisiopatologia , Doenças Profissionais/fisiopatologia , Prevalência , Medição de Risco , Fatores de Risco , Autorrelato , Inquéritos e Questionários , Extremidade Superior/fisiopatologia , Adulto Jovem
15.
Artigo em Inglês | MEDLINE | ID: mdl-31671611

RESUMO

Trans, trans-muconic acid (tt-MA) is a metabolite that is widely used as a biomarker to identify low exposure to benzene, a human carcinogen. This study aimed to investigate occupational factors related to the urinary tt-MA detection of benzene exposed workers in gasoline stations. Spot urine samples were collected and analyzed for tt-MA using a high performance liquid chromatography. Additional data were collected via subject interviews using a structured questionnaire. The personal benzene concentration was measured and analyzed by gas chromatography with a flame ionization detector. Results showed that, among the 170 workers, tt-MA was detected in 24.7% of workers and the concentration ranged from 23.0 to 1127.8 µg/g creatinine. Over 25% of those detections possessing tt-MA exceeding the recommended 500 µg/g creatinine was safe. A multiple logistic regression analysis identified that factors significantly associated with the detectable tt-MA were having no other part-time jobs (ORadj = 4.2), personal benzene concentrations of 0.05 ppm or higher (ORadj = 10.3), close to fuel nozzle during refuelling (ORadj = 93.7), and no job training (ORadj = 2.74). Safety training is recommended for those tt-MA detected workers or under a reference benzene concentration of 0.05 ppm or higher. The proposed reference of occupational action level to benzene exposure is 0.05 ppm and compliance could be assessed tt-MA for biomonitoring of those benzene exposed workers.


Assuntos
Benzeno/análise , Gasolina , Exposição Ocupacional/análise , Ácido Sórbico/análogos & derivados , Adulto , Biomarcadores , Carcinógenos/análise , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Monitoramento Ambiental/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Sórbico/análise , Tailândia , Adulto Jovem
16.
Artigo em Inglês | MEDLINE | ID: mdl-31315313

RESUMO

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.


Assuntos
Poluentes Ocupacionais do Ar/análise , Benzeno/análise , Carcinógenos/análise , Gasolina , Exposição por Inalação/análise , Exposição Ocupacional/análise , Emissões de Veículos , Monitoramento Ambiental , Feminino , Humanos , Masculino , Medição de Risco
17.
J Physiol ; 597(1): 225-235, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30284249

RESUMO

KEY POINTS: During myotonia congenita, reduced chloride (Cl- ) conductance results in impaired muscle relaxation and increased muscle stiffness after forceful voluntary contraction. Repetitive contraction of myotonic muscle decreases or even abolishes myotonic muscle stiffness, a phenomenon called 'warm up'. Pharmacological inhibition of low Cl- channels by anthracene-9-carboxylic acid in muscle from mice and ADR ('arrested development of righting response') muscle from mice showed a relaxation deficit under physiological conditions compared to wild-type muscle. At increased osmolarity up to 400 mosmol L-1 , the relaxation deficit of myotonic muscle almost reached that of control muscle. These effects were mediated by the cation and anion cotransporter, NKCC1, and anti-myotonic effects of hypertonicity were at least partly antagonized by the application of bumetanide. ABSTRACT: Low chloride-conductance myotonia is caused by mutations in the skeletal muscle chloride (Cl- ) channel gene type 1 (CLCN1). Reduced Cl- conductance of the mutated channels results in impaired muscle relaxation and increased muscle stiffness after forceful voluntary contraction. Exercise decreases muscle stiffness, a phenomena called 'warm up'. To gain further insight into the patho-mechanism of impaired muscle stiffness and the warm-up phenomenon, we characterized the effects of increased osmolarity on myotonic function. Functional force and membrane potential measurements were performed on muscle specimens of ADR ('arrested development of righting response') mice (an animal model for low gCl- conductance myotonia) and pharmacologically-induced myotonia. Specimens were exposed to solutions of increasing osmolarity at the same time as force and membrane potentials were monitored. In the second set of experiments, ADR muscle and pharmacologically-induced myotonic muscle were exposed to an antagonist of NKCC1. Upon osmotic stress, ADR muscle was depolarized to a lesser extent than control wild-type muscle. High osmolarity diminished myotonia and facilitated the warm-up phenomenon as depicted by a faster muscle relaxation time (T90/10 ). Osmotic stress primarily resulted in the activation of the NKCC1. The inhibition of NKCC1 with bumetanide prevented the depolarization and reversed the anti-myotonic effect of high osmolarity. Increased osmolarity decreased signs of myotonia and facilitated the warm-up phenomenon in different in vitro models of myotonia. Activation of NKCC1 activity promotes warm-up and reduces the number of contractions required to achieve normal relaxation kinetics.


Assuntos
Miotonia Congênita/fisiopatologia , Concentração Osmolar , Animais , Bumetanida/farmacologia , Modelos Animais de Doenças , Feminino , Masculino , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Inibidores de Simportadores de Cloreto de Sódio e Potássio/farmacologia , Membro 2 da Família 12 de Carreador de Soluto/fisiologia
18.
PLoS One ; 13(8): e0203394, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30161266

RESUMO

The number of smartphone users globally is rapidly increasing. This study aimed to assess the level of ergonomic risk to smartphone users, and to evaluate the correlation between any self-reported musculoskeletal disorders and the level of ergonomic risk. Thirty participants completed a questionnaire, tailored specifically for smartphone users, to determine any musculoskeletal disorders. Participants were given a seated smartphone texting task and their postures were video recorded during the task. The video scenarios were evaluated by three independent researchers to determine the level of ergonomic risk using the Rapid Upper Limb Assessment (RULA) tool. RULA is an observation-based screening tool which has been widely used to assess the postural risk of IT device users. However, it has not yet been specifically utilized with smartphone users. The RULA tool scores identified ergonomics risks from using smartphones to text. Most smartphone users had a total RULA Grand Score of 6 for both sides (left side: 80.00%, right side: 90.00%), indicating the need for further investigation and changes (Action Level 3). Notably, no participants had acceptable RULA Grand Scores of 1 or 2. The correlation between musculoskeletal disorders and the ergonomic risk among smartphone users was determined using the Chi-Square test and Fisher's exact test; p<0.05 was considered statistically significant. There was a significant correlation between right RULA Grand Score and neck musculoskeletal disorder (χ2 = 9.424 at p value = 0.009) and right RULA Grand Score and upper back musculoskeletal disorder (χ2 = 31.717 at p value <0.001). RULA Score B (combination of neck, trunk and leg postures) and RULA Score D (combination of Score B, muscle use and force scores for group B) were also significantly correlated with neck musculoskeletal disorders (χ2 = 19.286 at p value<0.001 and χ2 = 9.310 at p value = 0.002 respectively). The RULA results identified the high ergonomics risk of smartphone users, this resulted from two key risk factors: posture and muscle use. The neck, trunk and leg postures had a combined effect on neck musculoskeletal disorders. Future investigations should consider these factors when designing ergonomic interventions for smartphone users.


Assuntos
Braço , Ergonomia , Doenças Musculoesqueléticas/etiologia , Smartphone , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Postura , Medição de Risco/métodos , Fatores de Tempo , Gravação em Vídeo , Adulto Jovem
19.
J Med Assoc Thai ; 100(2): 230-8, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-29916644

RESUMO

Background: Musculoskeletal disorders (MSDs) are common complaints among workers who work in intensive manual labor including informal workers. Workers who have worked with prolonged improper posture have clearly decreased their physical fitness and increased the risk of musculoskeletal disorders. Objective: This cross-sectional study aimed to investigate the prevalence of muscular discomfort and to assess the physical fitness of informal garment female workers. Material and Method: The subjects were 1,674 informal garment female workers in Udon Thani Province. Data were collected by using a structured questionnaire including complaints of muscular discomfort. Physical fitness tests were done by using standard tools for testing back-leg strength, flexibility and hand grip strength. Results: The highest complaint of muscular discomfort during the last month was located at the low back (41.75%), followed by the shoulders (41.21%). Considering the severity as severe discomfort, the highest prevalence was found at the low back (61.47%), followed by neck (61.23%). Those two areas were also presented as the highest frequency of discomfort for every day pain. In general, the majority of workers had physical fitness at fair level and low back strength significantly correlated with muscular discomfort. Conclusion: The significant findings among informal garment workers were muscular discomfort predominantly located on the low back and the factor of low back strength correlated with that muscular discomfort. The suggestion is there should be a supporting surveillance program for prevention of chronic low back pain by a prospective cohort study as well as maintaining the physical fitness by an exercise program for these informal garment workers.


Assuntos
Força da Mão , Doenças Musculoesqueléticas , Doenças Profissionais , Aptidão Física , Vestuário , Estudos Transversais , Feminino , Humanos , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários , Tailândia
20.
Malar J ; 14: 3, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25567111

RESUMO

BACKGROUND: Malaria is a major health problem in Thailand, especially in areas adjacent to the borders of Myanmar. Delay in seeking treatment is an important factor in the development of severe complications, death and the transmission of the disease. This study aimed to investigate factors affecting delays in seeking treatment of malaria patients. METHODS: A cross-sectional analytic study was conducted in 456 malaria patients along the Thailand-Myanmar border. Patients were selected by stratified sampling from 11 malaria clinics and five public hospitals in Tak Province, Thailand. Data were collected by the use of a structured interview questionnaire and from patient's medical records. RESULTS: The majority of patients were categorized with an ethnicity of 'hill tribe' (65.8%), followed by Thai (34.2%). Seventy-nine per cent of patients delayed seeking treatment. A simple logistic regression identified significant factors affecting delays in seeking treatment: people of "hill tribe" ethnicity; plasmodium species; self-treatment; visiting sub-district health promotion hospital/malaria post before visiting a malaria clinic or public hospital; and low to medium social support. After being subjected to multivariate analysis, factors significantly associated with the delay were "hill tribe" ethnicity (ORadj = 2.32, 95% CI: 1.34-4.04); infection with P.vivax (ORadj=2.02, 95% CI: 1.19-3.41; self-treatment (ORadj = 1.73, 95% CI: 1.04-2.85); and receiving a low degree of social support (ORadj = 2.58, 95% CI: 1.24-5.35). CONCLUSIONS: Emphasis should be placed on need for early diagnosis and treatment in malaria patients as well as on ensuring the first facility for detection and treatment of malaria is a malaria clinic or public hospital, and the promotion of social support. These are especially important issues for the health of hill tribe people.


Assuntos
Antimaláricos/uso terapêutico , Diagnóstico Tardio , Malária/diagnóstico , Malária/tratamento farmacológico , Aceitação pelo Paciente de Cuidados de Saúde , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Entrevistas como Assunto , Masculino , Prontuários Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Tailândia , Fatores de Tempo , Adulto Jovem
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