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*

The context of specific criteria for the recognition of occupational diseases (ODs) due to physical agents in the Enforcement Decree of the Industrial Accident Compensation Insurance Act (ED-IACIA) and the Labor Standard Act (LSA) does not describe definite disease along with the agents but listed symptoms or obscure clinical conditions. Moreover, the needs for an amendment of these Acts have recently attracted renewed interest. To establish agreed criteria for compensable ODs due to physical agents, we reviewed the criteria for recognizing ODs on the basis of International Labor Organization (ILO) documents and European Union (EU) guideline. After providing a brief review of the history of OD outbreaks due to physical exposure in South Korea and the responses to them, we describe the basis for the recent amendments to the IACI Act and LSA and assess their appropriateness. On the basis of these findings, this study could be helpful for determining and compensating process of ODs. However, further work is required to ascertain the scientific relationship between diseases caused by physical agents and the exposure criteria.
Accidents, Occupational ; Humans ; Male ; Noise/*adverse effects ; Occupational Diseases/*economics ; Occupational Exposure/adverse effects ; Radiation Injuries/*economics ; Republic of Korea ; Vibration/*adverse effects ; Workers' Compensation/*economics

OBJECTIVETo study the effects of behind legs vibrations on erectile function in male rabbits through the concentration of plasma reproductive hormone and the expression of nitric oxide synthase (eNOS), endothelin-1 (ET-1) mRNA in vibrated male rabbits.

METHODS30 male adult rabbits were assigned randomly to A group (vibration power: 3.02 m/s(2)), B group (vibration power: 6.13 m/s(2)), C group (vibration power: 12.26 m/s(2)) and control group. The concentration of expression of eNOS, ET-1 mRNA were measured with RT-PCR after rated for 30 days.

RESULTS(1) Compared with 0 days vibration, after exposure to vibration for 10, 20, 30 days, the A, B, C group concentration of plasma T, LH are much lower (P < 0.05), the concentration of plasma E2 is much higher. (2) Compared with control group after exposed for 30 days, the expression of ET-1 mRNA [B group:(17.39 +/- 4.59) x 104; C group: (36.21 +/- 13.13) x 104 ] were much higher and expression of eNOS mRNA [A group: (19.11 +/- 6.83) x 104; B group: (11.86 +/- 3.15) x 104; C group: (4.68 +/- 3.26) x 104] was much lower, there were significant differences (P < 0.01).

CONCLUSIONSThe vibration of behind legs in rabbits resulted the concentration of plasma T, LH are much lower, the concentration of plasma E2 is much higher, increased the expression of eNOS mRNA, decreased the expression of eNOS mRNA, then vary the erectile function.

Animals ; Endothelin-1 ; genetics ; metabolism ; Male ; Nitric Oxide Synthase Type III ; genetics ; metabolism ; Penile Erection ; Penis ; metabolism ; RNA, Messenger ; genetics ; Rabbits ; Vibration ; adverse effects

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

Causality ; Humans ; Occupational Exposure ; 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 magnetic resonance imaging (MRI) in the wrist joint of coal miners who work in excavation and vibration department.

METHODSForty-three coal miners with the hand-arm vibration disease served as the observation group while 20 workers who were not working in the vibration department acted as the control group. The patients in the observation group were divided into five subgroups according to the time when they received vibration. The regularity of the development of signs and symptoms of MRI was observed and analyzed.

RESULTSThe hydroarthrosis was most found in MRI. There were significant difference in hydroarthrosis (chi(2) = 8.80, P < 0.01), osteoporosis and osteomyelitis (chi(2) = 3.91, chi(2) = 5.01, P < 0.05 respectively) between the observation group and the control group. The edema of bone marrow and the avascular necrosis of ossa carpi were found only in the observation group and not found in the control group. The hydroarthrosis and the edema of bone marrow occurred most in the early stage of vibration. The signal in the edema of the bone marrow of the distal end of the radius was decreased in the GE sequence T(2)WI with the specificity.

CONCLUSION(1) Changes in the wrist joint occur in the early stage of the vibration work, and can be found in the MRI. (2) The edema of the bone marrow of the distal end of the radius is of great value in the diagnosis of the hand-arm vibration disease.

Adult ; Case-Control Studies ; Coal Mining ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Occupational Diseases ; diagnosis ; etiology ; Sensitivity and Specificity ; Vibration ; adverse effects ; Wrist Joint ; pathology

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

OBJECTIVETo study the effect of captopril on the nervous function in rabbits exposed to vibration.

METHODSRabbits were divided into vibration group, intervention group, and control group. Vibration group and intervention group were exposed to (tested by) vibration. Captopril was given to intervention group from the 11th day of vibration exposure. Somatosensory evoked potential (SEP) and motor nervous conduction function (MCF) were measured and analyzed in each group before and after vibration exposure.

RESULTSThe latent periods of N1, P1 and N2 of SEP in vibration group after vibration exposure were (30.76 +/- 4.26), (41.91 +/- 6.67), and (45.29 +/- 5.81) ms respectively, and in intervention group after vibration exposure were (27.00 +/- 3.04), (35.07 +/- 4.20) and (41.15 +/- 3.19) ms respectively. Compared with intervention group before and after exposure, and control group, the latent periods of each wave of SEP were delayed significantly (P < 0.05). The nervous conduction velocity, the distant wave amplitude, and the distant potential period of sciatic nerve in vibration group after vibration exposure were significantly different from those in intervention group [(35.69 +/- 4.37) m/s, (1.55 +/- 0.73) microV, (8.16 +/- 0.71) ms respectively vs (52.20 +/- 5.13) m/s, (2.89 +/- 0.36) microV, (7.26 +/- 0.77) ms respectively (P < 0.01)].

CONCLUSIONCaptopril may improve the impairment of nervous functions to a certain degree in rabbits exposed to vibration.

Animals ; Captopril ; pharmacology ; Evoked Potentials, Somatosensory ; drug effects ; Female ; Male ; Neural Conduction ; drug effects ; Rabbits ; Sciatic Nerve ; drug effects ; physiology ; Vibration ; adverse effects

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