BACKGROUND: The effect of air pollution on annual change rates in grip strength and body composition in the elderly is unknown. OBJECTIVES: This study evaluated the effects of long-term exposure to ambient air pollution on change rates of grip strength and body composition in the elderly. METHODS: In the period 2016-2020, grip strength and body composition were assessed and measured 1-2 times per year in 395 elderly participants living in the Taipei basin. Exposure to ambient fine particulate matters (PM_2.5), nitric dioxide (NO₂), and ozone (O₃) from 2015 to 2019 was estimated using a hybrid Kriging/Land-use regression model. In addition, long-term exposure to carbon monoxide (CO) was estimated using an ordinary Kriging approach. Associations between air pollution exposures and annual changes in health outcomes were analyzed using linear mixed-effects models. RESULTS: An inter-quartile range (4.1 µg/m³) increase in long-term exposure to PM_2.5 was associated with a faster decline rate in grip strength (-0.16 kg per year) and skeletal muscle mass (-0.14 kg per year), but an increase in body fat mass (0.21 kg per year). The effect of PM_2.5 remained robust after adjustment for NO₂, O₃ and CO exposure. In subgroup analysis, the PM_2.5-related decline rate in grip strength was greater in participants with older age (>70 years) or higher protein intake, whereas in skeletal muscle mass, the decline rate was more pronounced in participants having a lower frequency of moderate or strenuous exercise. The PM_2.5-related increase rate in body fat mass was higher in participants having a lower frequency of strenuous exercise or soybean intake. CONCLUSIONS Among the elderly, long-term exposure to ambient PM_2.5 is associated with a faster decline in grip strength and skeletal muscle mass, and an increase in body fat mass. Susceptibility to PM_2.5 may be influenced by age, physical activity, and dietary protein intake; however, these modifying effects vary across different health outcomes, and further research is needed to clarify their mechanisms and consistency.
Humans ; Hand Strength ; Aged ; Male ; Female ; Environmental Exposure/adverse effects* ; Follow-Up Studies ; Taiwan ; Air Pollution/adverse effects* ; Particulate Matter/adverse effects* ; Muscle, Skeletal/drug effects* ; Air Pollutants/adverse effects* ; Ozone/adverse effects* ; Aged, 80 and over ; Adipose Tissue/drug effects* ; Body Composition/drug effects* ; Nitrogen Dioxide/adverse effects*

OBJECTIVES: To investigate the protective effects of dexmedetomidine (DEX) against heat stress (HS)-induced oncosis in human skeletal muscle cells (HSKMCs) and its underlying mechanisms. METHODS: A HSKMC model of HS-induced oncosis were established by 43 ℃ water bath for 4 h, and the effects of treatments with 30 μmol/L DEX, ML385 (a Nrf2 inhibitor) +DEX, si-Nrf2+HS, and si-Nrf2+DEX prior to modeling on cell viability was assessed using CCK-8 assay. Oncosis characteristics were evaluated using transmission electron microscopy and Annexin V-FITC/PI flow cytometry. The oxidative stress markers (GSH, GSH-Px, MDA, SOD and ROS), mitochondrial membrane potential, energy metabolism, and inflammatory cytokines (TNF-α, IL-6 and IL-1β) in the cells were quantified using standard kits, and the expressions of porimin, caspase-3 and Nrf2 pathway proteins were analyzed using Western blotting and qRT-PCR. RESULTS: HS induced typical oncotic features in HSKMCs including organelle swelling and cytoplasmic vacuolization. DEX pretreatment significantly attenuated these changes, reduced Annexin V⁺/PI⁺ cell ratio and cellular porimin expression, and lowered the levels of ROS and MDA while restoring GSH and SOD levels. DEX pretreatment also significantly increased the mitochondrial membrane potential and ATP level, upregulated the expressions of Nrf2, p-Nrf2, HO-1 and NQO1, and suppressed the expressions of TNF-α, IL-6 and IL-1β. The protective effects of DEX were obviously attenuated by interventions with ML385 or si-Nrf2. CONCLUSIONS DEX mitigates HS-induced HSKMC oncosis by activating the Nrf2/HO-1 pathway to relieve oxidative stress, mitochondrial dysfunction, and inflammatory responses.
Humans ; Dexmedetomidine/pharmacology* ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress/drug effects* ; Heat-Shock Response/drug effects* ; Signal Transduction/drug effects* ; Membrane Potential, Mitochondrial ; Muscle, Skeletal/cytology* ; Heme Oxygenase-1/metabolism* ; Apoptosis/drug effects*

Objective To investigate diabetes-mediated changes in the neuromuscular pharmacodynamics of rocuronium in rats. Methods Diabetes mellitus was induced by a single injection of streptozotocin in rats.A total of 24 male SD rats were assigned to four groups using random number table:the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group(6 rats per group).The sciatic nerve was stimulated in a rain-of-four(TOF)pattern,and the twitch tension changes in the tibialis anterior muscle were demonstrated by mechanomyography after intravenous injection of rocuronium in vivo.The time course characteristics of rocuronium,including onset time,and the recovery time from rocuronium injection to TOF ratio 75%(RT75%)and 90%(RT90%),were recorded,and half maximal inhibitory concentration(IC)values of rocuronium were determined using a four-parameter dose response curve. Results Compared with the normal controls,the diabetic rats had significantly prolonged onset time of rocuronium,while the RT75% and RT90% were decreased at all rocuronium doses(P<0.001).The time course changes became increasingly significant as the duration of diabetes lengthened(P<0.001).The IC and 95% confidence interval values for rocuronium in the normal control group,diabetic 2-week group,diabetic 4-week group,and diabetic 8-week group were 0.37(0.35-0.38)mg/kg,0.44(0.43-0.46)mg/kg,0.59(0.57-0.61)mg/kg,and 0.64(0.61-0.66)mg/kg,respectively.IC values were significantly higher in the diabetic groups vs.normal control(P<0.001)and gradually increased as the duration of diabetes lengthened(P<0.001).Conclusion Diabetes is associated with the rat skeletal muscle hyposensitivity to rocuronium,which is featured by prolonged onset time of rocuronium,decreased RT 75% and RT 90%,and right shift of the cumulative dose-response curve of rocuronium.
Animals ; Diabetes Mellitus, Experimental ; physiopathology ; Male ; Muscle, Skeletal ; drug effects ; Neuromuscular Nondepolarizing Agents ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Rocuronium ; pharmacology

OBJECTIVEScorpion (Hemiscorpius lepturus) stings are a public health concern in Iran, particularly in south and southwestern regions of Iran. The gold standard for the treatment of a scorpion sting is anti-venom therapy. However, immunotherapy can have serious side effects, such as anaphylactic shock (which can sometimes even lead to death). The aim of the current study was to demonstrate the protective effect of ozone against toxicity induced by Hemiscorpius lepturus (H. lepturus) venom in mice.

METHODSEight hours after the injection of ozone to the experimental design groups, the male mice were decapitated and mitochondria were isolated from five different tissues (liver, kidney, heart, brain, and spinal cord) using differential ultracentrifugation. Then, assessment of mitochondrial parameters including mitochondrial reactive oxidative species (ROS) production, mitochondrial membrane potential (MMP), ATP level, and the release of cytochrome c from the mitochondria was performed.

RESULTSOur results showed that H. lepturus venom-induced oxidative stress is related to ROS production and MMP collapse, which is correlated with cytochrome c release and ATP depletion, indicating the predisposition to the cell death signaling.

CONCLUSIONIn general, ozone therapy in moderate dose can be considered as clinically effective for the treatment of H. lepturus sting as a protective and antioxidant agent.

Animals ; Brain ; drug effects ; metabolism ; Cytochromes c ; metabolism ; Heart ; drug effects ; Kidney ; drug effects ; metabolism ; Liver ; drug effects ; metabolism ; Male ; Membrane Potential, Mitochondrial ; drug effects ; Mice ; Mice, Inbred BALB C ; Muscle, Skeletal ; drug effects ; metabolism ; Myocardium ; metabolism ; Ozone ; pharmacology ; Scorpion Venoms ; toxicity ; Scorpions ; physiology ; Spinal Cord ; drug effects ; metabolism

PURPOSE: To investigate the effect of intramuscular Botulinum toxin type A (BoNT-A) injection on gait and dynamic foot pressure distribution in children with spastic cerebral palsy (CP) with dynamic equinovarus foot. MATERIALS AND METHODS: Twenty-five legs of 25 children with CP were investigated in this study. BoNT-A was injected into the gastrocnemius (GCM) and tibialis posterior (TP) muscles under the guidance of ultrasonography. The effects of the toxin were clinically assessed using the modified Ashworth scale (MAS) and modified Tardieu scale (MTS), and a computerized gait analysis and dynamic foot pressure measurements using the F-scan system were also performed before injection and at 1 and 4 months after injection. RESULTS: Spasticity of the ankle plantar-flexor in both the MAS and MTS was significantly reduced at both 1 and 4 months after injection. On dynamic foot pressure measurements, the center of pressure index and coronal index, which represent the asymmetrical weight-bearing of the medial and lateral columns of the foot, significantly improved at both 1 and 4 months after injection. The dynamic foot pressure index, total contact area, contact length and hind foot contact width all increased at 1 month after injection, suggesting better heel contact. Ankle kinematic data were significantly improved at both 1 and 4 months after injection, and ankle power generation was significantly increased at 4 months after injection compared to baseline data. CONCLUSION: Using a computerized gait analysis and foot scan, this study revealed significant benefits of BoNT-A injection into the GCM and TP muscles for dynamic equinovarus foot in children with spastic CP.
Adolescent ; Ankle Joint ; Botulinum Toxins, Type A/administration & dosage/*pharmacology ; Cerebral Palsy/*complications/drug therapy ; Child ; Child, Preschool ; Clubfoot/*drug therapy/*etiology/physiopathology ; Female ; Foot ; Gait/*drug effects/physiology ; Humans ; Injections, Intramuscular ; Male ; Muscle Spasticity/drug therapy ; Muscle, Skeletal/diagnostic imaging ; Neuromuscular Agents/administration & dosage/*pharmacology ; Pressure ; Prospective Studies ; Treatment Outcome ; Weight-Bearing

Animals ; Carnitine ; pharmacology ; H(+)-K(+)-Exchanging ATPase ; metabolism ; Mitochondria, Muscle ; enzymology ; Muscle, Skeletal ; drug effects ; Physical Conditioning, Animal ; Rats

OBJECTIVETo investigate the long-term clinical efficacy and adverse effects of botulinum toxin-A (BTX-A) injection in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy.

METHODSEighty children aged 9-36 months with cerebral palsy and gastrocnemius spasticity were selected and randomly divided into a BTX-A injection group and a conventional treatment group (n=40 each). The children in the BTX-A injection group received injections of BTX-A guided by color Doppler ultrasound and 4 courses of rehabilitation training after injection. Those in the conventional treatment group received 4 courses of the same rehabilitation training alone. Before treatment and at 1, 2, 3, and 6 months after treatment, the modified Tardieu scale (MTS) was applied to assess the degree of gastrocnemius spasticity, the values in the passive state measured by surface electromyography (sEMG) were applied to evaluate muscle tension, and the Gross Motor Function Measure (GMFM) was used to evaluate gross motor function.

RESULTSCompared with the conventional treatment group, the BTX-A injection group had significantly greater reductions in MTS score and the values in the passive state measured by sEMG (P<0.05), as well as significantly greater increases in joint angles R1 and R2 in MTS and gross motor score in GMFM (P<0.05). No serious adverse reactions related to BTX-A injection were found.

CONCLUSIONSBTX-A injection is effective and safe in the treatment of gastrocnemius spasticity in children aged 9-36 months with cerebral palsy.

Botulinum Toxins, Type A ; administration & dosage ; Cerebral Palsy ; drug therapy ; physiopathology ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Muscle Spasticity ; drug therapy ; physiopathology ; Muscle, Skeletal ; drug effects ; physiopathology ; Prospective Studies ; Treatment Outcome

This study investigated the protective effect of ATP on skeletal muscle satellite cells damaged by H₂O₂in neonatal rats and the possible mechanism. The skeletal muscle satellite cells were randomly divided into four groups: normal group, model group (cells treated with 0.1 mmol/L H₂O₂for 50 s), protection group (cells treated with 16, 8, 4, 2, 1, 0.5, or 0.25 mmol/L ATP for 24 h, and then with 0.1 mmol/L H₂O₂for 50 s), proliferation group (cells treated with 16, 8, 4, 2, 1, 0.5, or 0.25 mmol/L ATP for 24 h). MTT assay, FITC+PI+DAPI fluorescent staining, Giemsa staining and immunofluorescence were performed to examine cell viability and apoptosis, and apoptosis-related proteins. The results showed that the survival rate of skeletal muscle satellite cells was decreased and the apoptosis rate was increased after H₂O₂treatment (P<0.01). Different doses of ATP had different effects on skeletal muscle satellite cells damaged by H₂O₂: the survival rate of muscle satellite cells treated with ATP at 4, 2, or 1 mmol/L was increased. The protective effect was most profound on cells treated with 2 mmol/L ATP. Immunofluorescence showed that ATP could increase the number of Bcl-2-positive cells (P<0.01) and decrease the number of the Bax-positive cells (P<0.01). It was concluded that ATP could protect skeletal muscle satellite cells against H₂O₂damage in neonatal rats, which may be attributed to the up-regulation of the expression of Bcl-2 and down-regulation of Bax, resulting in the suppression of apoptosis.
Adenosine Triphosphate ; pharmacology ; Animals ; Hydrogen Peroxide ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Satellite Cells, Skeletal Muscle ; drug effects

OBJECTIVETo observe the effect of Shenshuai Yingyang Capsule (SSYYJN) in ameliorating muscle atrophy in rats with chronic renal failure (CRF) and explore the role of Wnt7a-Akt/mTOR signal pathway in mediating this effect.

METHODSMale rats were randomly assigned to 5/6 nephrectomy group and sham-operated group, and the former group was further randomly divided into CRF model group, KA group, and SSYYJN group. The size of anterior tibia muscle was examined microscopically with HE staining. Protein synthesis in the soleus muscle was investigated by (14)C-phenylalanine experiment, and the expression of Wnt7a, frizzled-7, phospho-Akt, phospho-mTOR and GAPDH were detected with Western blotting.

RESULTSThe body weight, the wet and dry weight, cross-sectional area, and muscle protein synthesis of the anterior tibia muscles, and expressions of the proteins in the Wnt7a/Akt signaling pathway all increased significantly in SSYYJN and KA groups as compared with those in the model group.

CONCLUSIONSSYYJN can effectively improve muscle atrophy in the rat model of CRF possibly by reversing the reduction in the expressions of Wnt7a/Akt signaling pathway proteins in the skeletal muscles.

Animals ; Capsules ; Drugs, Chinese Herbal ; pharmacology ; Kidney Failure, Chronic ; complications ; Male ; Muscle Proteins ; biosynthesis ; Muscle, Skeletal ; drug effects ; Muscular Atrophy ; drug therapy ; Nephrectomy ; Proto-Oncogene Proteins ; metabolism ; Rats ; Signal Transduction ; TOR Serine-Threonine Kinases ; metabolism ; Wnt Proteins ; metabolism

Gabexate mesilate (GM) is a trypsin inhibitor, and mainly used for treatment of various acute pancreatitis, including traumatic pancreatitis (TP), edematous pancreatitis, and acute necrotizing pancreatitis. However, due to the characteristics of pharmacokinetics, the clinical application of GM still needs frequently intravenous administration to keep the blood drug concentration, which is difficult to manage. Specially, when the blood supply of pancreas is directly damaged, intravenous administration is difficult to exert the optimum therapy effect. To address it, a novel thermosensitive in-situ gel of gabexate mesilate (GMTI) was developed, and the optimum formulation of GMTI containing 20.6% (w/w) P-407 and 5.79% (w/w) P188 with different concentrations of GM was used as a gelling solvent. The effective drug concentration on trypsin inhibition was examined after treatment with different concentrations of GMTI in vitro, and GM served as a positive control. The security of GMTI was evaluated by hematoxylin-eosin (HE) staining, and its curative effect on grade II pancreas injury was also evaluated by testing amylase (AMS), C-reactive protein (CRP) and trypsinogen activation peptide (TAP), and pathological analysis of the pancreas. The trypsin activity was slightly inhibited at 1.0 and 5.0 mg/mL in GM group and GMTI group, respectively (P<0.05 vs. P-407), and completely inhibited at 10.0 and 20.0 mg/mL (P<0.01 vs. P-407). After local injection of 10 mg/mL GMTI to rat leg muscular tissue, muscle fiber texture was normal, and there were no obvious red blood cells and infiltration of inflammatory cells. Furthermore, the expression of AMS, CRP and TAP was significantly increased in TP group as compared with control group (P<0.01), and significantly decreased in GM group as compared with TP group (P<0.01), and also slightly inhibited after 1.0 and 5.0 mg/mL GMTI treatment as compared with TP group (P<0.05), and significantly inhibited after 10.0 and 20.0 mg/mL GMTI treatment as compared with TP group (P<0.01). HE staining results demonstrated that pancreas cells were uniformly distributed in control group, and they were loosely arranged, partially dissolved, with deeply stained nuclei in TP group. Expectedly, after gradient GMTI treatment, pancreas cells were gradually restored to tight distribution, with slightly stained nuclei. This preliminary study indicated that GMTI could effectively inhibit pancreatic enzymes, and alleviate the severity of trauma-induced pancreatitis, and had a potential drug developing and clinic application value.
Amylases ; metabolism ; Animals ; C-Reactive Protein ; metabolism ; Delayed-Action Preparations ; chemical synthesis ; pharmacokinetics ; pharmacology ; Gabexate ; chemistry ; pharmacokinetics ; pharmacology ; Gels ; Male ; Muscle, Skeletal ; drug effects ; enzymology ; Oligopeptides ; metabolism ; Pancreas ; drug effects ; enzymology ; pathology ; Pancreatitis ; drug therapy ; enzymology ; etiology ; pathology ; Poloxamer ; chemistry ; Rats ; Rats, Sprague-Dawley ; Serine Proteinase Inhibitors ; chemistry ; pharmacokinetics ; pharmacology ; Temperature ; Wounds, Penetrating ; complications ; drug therapy ; enzymology ; pathology