By implementing epoch-making policies of industrial promotion, the national economy has made a remarkable development. As a result of such economic growth, industrial accidents and occupational diseases have become a serious problem in Korean society. In the presidential order for the execution of the Korean labor standard law, neuritis and other diseases stemming from health impairments due to vibration in industrial processes are designated to be dealt with as vibration diseases. In the case of vibration disease, industrial accident compensation is not effectively paid. In order to investigate vibration hazards of rock-drill operators, the author studied subjective symptoms and did physical function tests on a total of 208 persons (vibration exposed group), who used rock-drills, and 115 persons (control group) who are not using rock-drills at anthracite mines. The results of physical function test are as follows. 1. There is no difference in smoking habits between the vibration exposure group and the control group. 2. In the use of their ear plugs, both the vibration exposed group and the control group showed a low tendency in using the ear plugs. 3. In the prevalence rate of white finger, the vibration exposed group reached 12.5 percent, but only 0.9 percent in the control group. Thus, both groups showed different rates in the initiation of their illness (p < 0.01). 4. The prevalence rate of finger numbness for the vibration exposed group was 23.1 percent, but only 9.6 percent in control group (p < 0.05). 5. In the prevalence rate of insomnia, the vibration exposed group had 22.6 percent and the control group 9.6 percent. Thus, the vibration exposure group showed a higher rate than the control group (p < 0.05). 6. In the vibration sense threshold, the vibration exposed group showed a statistically higher level than the control group (p < 0.01). 7. In the mean value of skin temperature, the control group was higher than the vibration exposed group (p < 0.05). 8. In the amount of perspiration, the exposed group measured higher than the control group (p < 0.01).
Adult ; Coal Mining* ; Human ; Middle Age ; Occupational Diseases/epidemiology* ; Occupational Diseases/physiopathology ; Raynaud's Disease/epidemiology ; Sensory Thresholds ; Smoking ; Vibration/adverse effects*

BACKGROUND AND PURPOSE: Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability. METHODS: Eighty atherosclerotic plaques were collected from 74 patients undergoing carotid endarterectomy. Clinical information was obtained from each patient, and plaque morphology was examined at the macroscopic and microscopic levels. The immunohistochemical expressions of MMPs were graded using semiquantitative scales. RESULTS: Macroscopic ulceration (84.6% versus 63.4%, p=0.042) and microscopic cap rupture (79.5% versus 51.2%, p=0.010) were more common in symptomatic than in asymptomatic patients. Immunoreactivities of MMP-2 and MMP-9 were increased in 40 and 36 atheromatous plaques, respectively. Macroscopic ulceration was strongly correlated with the expressions of MMP-2 (p<0.001) and MMP-9 (p=0.001). There were significant correlations between increased MMP-2 expression and cap rupture (p=0.002), intraplaque hemorrhage (p=0.039), and a thin fibrous cap (p=0.002), and between increased MMP-9 expression and cap rupture (p=0.010) and a large lipid core (p=0.013). CONCLUSIONS: Plaque rupture was significantly associated with the development of vascular events in carotid atherosclerotic disease. MMP-2 and MMP-9 are strongly correlated with plaque instability.
Atherosclerosis ; Carotid Arteries ; Carotid Artery Diseases ; Endarterectomy, Carotid ; Hemorrhage ; Humans ; Matrix Metalloproteinases ; Plaque, Atherosclerotic ; Rupture ; Stroke ; Thromboembolism ; Ulcer