Causality ; Humans ; Occupational Exposure ; Vibration ; adverse effects

Environmental Exposure ; adverse effects ; Hearing Loss ; etiology ; Humans ; Noise, Occupational ; adverse effects ; Occupational Diseases ; etiology ; Occupational Exposure ; adverse effects ; Risk Factors ; Smoking ; adverse effects ; Vibration ; adverse effects

Adult ; Cold Temperature ; Fingers ; Hand-Arm Vibration Syndrome ; diagnosis ; Humans ; Occupational Exposure ; adverse effects ; Skin Temperature ; Thermography ; methods ; Vibration ; adverse effects ; Young Adult

OBJECTIVETo study the combined effect of low temperature and vibration on function of peripheral circulation and nerve.

METHODS64 rabbits were divided into control group, low temperature group, vibration group and combined effect group randomly, 16 each group. The changes of concentration of ET, Ang II, NO in plasma and SCV, amplitude of sensory nerve action potential, latency of sensory nerve action potential, MCV, distal amplitude of motor nerve, and distal latency of motor nerve were measured before and after experiment.

RESULTSAfter experiment, the concentration of ET, Ang II, NO and SCV, amplitude of sensory nerve action potential, latency of sensory nerve action potential, MCV, distal amplitude of motor nerve, and distal latency of motor nerve were (68.84+/-14.81) pg/ml, (544.01+/-70.20) pg/ml, (123.73+/-9.58) nmol/ml, (25.36+/-6.96) m/s, (1.84+/-0.65) microV, (4.05+/-1.04) m/s, (27.40+/-6.05) m/s, (1.60+/-0.52) microV, (3.51+/-1.30) m/s respectively in low temperature group; (70.22+/-15.02) pg/ml, (540.77+/-68.25) pg/ml, (129.46+/-11.99) nmol/ml, (27.69+/-6.16) m/s, (2.19+/-0.53) microV, (3.86+/-0.89) m/s, (30.03+/-5.21) m/s, (1.65+/-0.49) microV, (3.36+/-l.11) m/s respectively in vibration group; (88.47+/-13.20) pg/ml, (687.38+/-101.44) pg/ml, (70.66+/-4.99) nmol/ml, (20.82+/-3.65) m/s, (1.21+/-0.64) microV, (5.05+/-0.94) m/s, (19.97+/-4.37) m/s, (1.09+/-0.49) microV, (4.49+/-1.26) m/s respectively in combined effect group; compared with pre-experiment, the concentration of ET and Ang II in low temperature group, vibration group and combined effect group were increased after experiment, and the NO was decreased (P<0.05); the nerve conduct velocity and amplitude was decreased and the latency was delayed (P<0.05). After experiment, the concentrations of ET and Ang II in combined effect group were higher than low temperature group and vibration group, and the concentration of NO in combined effect group was lower than low temperature group and vibration group (P<0.05). After experiment, the SCV and MCV in combined effect group were slower than low temperature group and vibration group; the amplitude of sensory nerve action potential and distal amplitude of motor nerve were less than low temperature group and vibration group; the latency of sensory nerve action potential and distal latency of motor nerve in combined effect group was longer than low temperature group and vibration group. The factorial analysis results indicated the synergistic effect between low temperature and vibration (P<0.05).

CONCLUSIONVibration-induced peripheral vascular impairment and nerve impairment would be intensified by low temperature.

Animals ; Blood Circulation ; physiology ; Cold Temperature ; adverse effects ; Female ; Male ; Peripheral Nerves ; physiopathology ; Rabbits ; Vibration ; adverse effects

Animals ; Cytokines ; blood ; Humans ; Peripheral Vascular Diseases ; etiology ; physiopathology ; Rabbits ; Vibration ; adverse effects

Animals ; Female ; Male ; Rabbits ; Tumor Necrosis Factor-alpha ; analysis ; Vibration ; adverse effects

OBJECTIVETo study the effects of local vibration on blood-lipids and whole blood viscosity.

METHODSThe total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL), whole blood viscosity, apolipoprotein (Apo-), red blood cell (RBC), platelet (PLT), mean corpuscular volume (MCV), serum-protein, postprandial blood sugar (PBS), and serum-protein of experimental and control workers were detected. The difference of the means and abnormal rates of two groups were compared.

RESULTSThe means of TG, TC, HDL in exposed group [(1.01 +/- 0.85), (3.25 +/- 0.61), (1.14 +/- 0.20) mmol/L respectively] were significantly lower than that of control group [(1.89 +/- 1.47), (3.87 +/- 0.82), (1.22 +/- 0.26) mmol/L, respectively, P < 0.01 or P < 0.05]. Apo-A was also decreased [(1.13 +/- 0.29) g/L vs (1.23 +/- 0.16) g/L, P < 0.01]. The mean of whole blood viscosity were significantly increased in exposed group [(2.76 +/- 0.42) mPa.s vs (2.54 +/- 0.33) mPa.s, P < 0.01]. The abnormal rate of Apo-A was significantly higher in exposed group (23.30%) than that in control (4.50%, P < 0.01).

CONCLUSIONLocal vibration may induce decrease in blood lipids, increase in blood viscosity and changes in some other blood parameters.

Adult ; Apolipoproteins A ; blood ; Blood Viscosity ; Humans ; Lipids ; blood ; Male ; Middle Aged ; Vibration ; adverse effects

Arm ; Hand ; Humans ; Occupational Diseases ; diagnosis ; etiology ; Reference Standards ; Vibration ; adverse effects

Objective: To study the effects of vibration on the expression of mitochondrial fusion and fission genes and ultrastructure of skeletal muscle in rabbits. Methods: Thirty-two 3.5-month-old New Zealand rabbits were randomly divided into low-intensity group, medium-intensity group, high-intensity group and control group, with 8 rabbits in each group. The rabbits in the experimental group were subjected to hind limb vibration load test for 45 days. The vibration intensity of the high intensity group was 12.26 m/s(2), the medium intensity group was 6.13 m/s(2), and the low intensity group was 3.02 m/s(2) according to the effective value of weighted acceleration[a(hw (4))] for 4 hours of equal energy frequency. The control group was exposed to noise only in the same experimental environment as the medium-intensity group. The noise levels of each group were measured during the vibration load experiment. After the test, the mRNA expression of mitochondrial fusion gene (Mfn1/Mfn2) and fission gene (Fis1, Drp1) by RT-PCR in the skeletal muscles were measured and the ultrastructure of the skeletal muscles were observed in high intensity group. Results: The mRNA expression of mitochondrial in the skeletal muscle tissues of control group, low intensity group, medium intensity group and high intensity group were Mfn1: 3.25±1.36, 3.85±1.90, 4.53±2.31 and 11.63±7.68; Mfn2: 0.68±0.25, 1.02±0.40, 0.94±0.33 and 1.40±0.45; Fis1: 1.05±0.62, 1.15±0.59, 1.53±1.06 and 2.46±1.51 and Drp1: 3.72±1.76, 2.91±1.63, 3.27±2.01 and 4.21±2.46, respectively. Compared with the control group, the expressions of Mfn1 mRNA, Mfn2 mRNA and Fis1 mRNA in the high-intensity group increased significantly (P<0.05) , and the expressions of Mfn2 mRNA in the medium-intensity group and the low-intensity group increased significantly (P<0.05) . Compared with the control group, the ultrastructure of skeletal muscle of high intensity group showed mitochondrial focal accumulation, cristae membrane damage, vacuole-like changes; Z-line irregularity of muscle fibers, and deficiency of sarcomere. Conclusion: Vibration must be lead to the abnormal mitochondrial morphology and structure and the disorder of energy metabolism due to the expression imbalance of mitochondrial fusion and fission genes in skeletal muscles of rabbits, which may be an important target of vibration-induced skeletal muscle injury.
Animals ; Hindlimb/metabolism* ; Mitochondria/metabolism* ; Mitochondrial Dynamics ; Mitochondrial Proteins/pharmacology* ; Muscle, Skeletal ; Rabbits ; Vibration/adverse effects*

Adolescent ; Adult ; Automobile Driving ; China ; Electrocardiography ; Female ; Heart ; physiopathology ; Humans ; Male ; Middle Aged ; Noise, Occupational ; adverse effects ; Occupational Exposure ; adverse effects ; Stress, Psychological ; etiology ; physiopathology ; Vibration ; adverse effects