Annals of Occupational and Environmental Medicine

Original Article

Silica Induced Apoptosis In Vitro and In Vivo: Ji Hong Kim, Hwang Shn Chang, Yung Mann Baag, Byung Yong Ahn, Kyoung Ah Kim, Young Lim; Korean Journal of Occupational and Environmental Medicine 1999;11(2):206-212. Published online June 30, 1999; DOI: https://doi.org/10.35371/kjoem.1999.11.2.206

Abstract PDF: Silica exposure results in acute inflammatory response followed by chronic fibrotic change. The mechanism for the maintenance of silica-induced inflammation has not been understood yet. Apoptosis is a morphologically distinct form of programed cell death that plays major role during homeostasis and in many diseases including cancer, acquired immune deficiency syndrome and neurodegenerative disorders. Apoptosis is characterized by cell shrinkage, membrane blebbing and nuclear condensation. To demonstrate the involvement of apoptosis in underlying mechanism for the development of silica-induced pathological changes, this study was designed in vitro and in vivo models. In in vitro study, alveolar epithelial cell line (A549) was stimulated with silica and performed flow cytometry and DNA electrophoresis. In in vivo study, bronchoalveolar lavage (BAL) was done to count the total and apoptotic cells from silica-instilled rats. The results were as follows: 1. Apoptotic cell fraction of silica-treated groups (10 and 50 microgram/cm2) was significantly higher than that of control group. 2. Genomic DNA from silica-treated groups (10 and 50 microgram/cm2 ) showed DNA ladder in agarose gel electrophoresis, while group of 1 microgram/cm2 didn't. 3. Total cell number and apoptotic cell number of BAL fluid from silica-instilled rats (10, 20 and 40 mg/kg) were significantly higher than those of control. 4. Silica induced apoptosis of cells in BAL fluid was confirmed by microscopic observation with nuclear fragmentation. These results suggest that apoptosis may contribute to development of silica-induced pathological changes.

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Original Article

Nailfold capillary microscopy for evaluating hand-arm vibration syndrome: Lee, Chan Boo , Sung, Joo Hyun , Park, Jung Hun , Yoo, Cheol In , Sim, Chang Sun , Oh, Ji Seon , Lee, Hun; Ann Occup Environ Med 2014;26(1):27-27.; DOI: https://doi.org/10.1186/s40557-014-0027-y

Abstract: OBJECTIVES
We evaluated nailfold capillary abnormalities in patients with hand-arm vibration syndrome using nailfold capillary microscopy.
METHODS
Fifty workers who underwent a special health examination because of exposure to hand-arm vibration at Ulsan University Hospital in 2012 (exposed group) and a control group of 50 white-collar employees were evaluated through a questionnaire survey regarding their present tasks, types of tools used, vibration exposure duration, use of protective wear, and medical history. Then, an occupational physician performed a physical examination for any hand deformities, skin problems, or motor and sensory dysfunctions of the upper extremities. The nailfold capillary morphologies (tortuous, crossing, bushy, meandering, branching, hemorrhage, avascular area, enlarged, and giant), capillary dimensions (afferent, top, venous, total width, and length), and specific counts (crossing and branching) on both fourth fingers were determined by a rheumatologist. Thereafter, the exposed subjects were assessed according to the Stockholm workshop classification scale. In total, 8 and 6 subjects in the exposed and control groups, respectively, were excluded from the study because of poor capillary microscopic image quality. In addition, 24 subjects in the exposed group with Stockholm vascular stage 0 were excluded. Finally, capillary morphology, dimensions, and specific counting were compared between the exposed (n = 18) and control groups (n = 44).
RESULTS
The exposed group had significantly greater crossing capillaries and abnormal capillary numbers that included crossing capillaries (crossing, branching, bushy, and meandering) but smaller branching and abnormal capillary numbers that excluded crossing capillaries (branching, bushy, and meandering) than the control group did. No significant difference in capillary dimensions was observed between the two groups. Despite the adjustment for age, smoking status, and underlying diseases, the statistical significance was unchanged. In the specific counting of the type of capillaries, the exposed group had a significantly higher total crossing count but fewer total branching count than the control group did. However, no statistical significance resulted after adjustment for age, smoking status, and underlying diseases.
CONCLUSIONS
In this study, the exposed group had significantly more crossing capillaries and a higher crossing count than the control group did.

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