1.Quantitative Analysis of Quartz, Mica, and Feldspar in Respirable Coalmine Dust in Taebaek Area by Fourier Transform Infrared Spectrophotometry.
Ho Chun CHOI ; Yong Hee CHEON ; Hae Jeong KIM ; Jeong Joo LEE
Korean Journal of Preventive Medicine 1988;21(2):271-283
A Fourier transform infrared spectrophotometric method was described for the determination of quartz, mica(sericite) and feldspar(potassium feldspar) in respirable dust in Taebaek area. The results were as follows; 1) The concentration of minerals were determined from the intensity of absorption peak of quartz at 799 cm-1, sericite at 539 cm-1, and potassium feldspar at 648 cm-1 respectively. 2) The precision(C. V. %) for the quartz determination was 7.70+/-2.68 % from 10 to 200 microgram of quartz. 3) The precision for the sericite determination was 16.34+/-6.82 % from 30 to 500 microgram of serictite. 4) The precision for the potassium feldspar determination was 5.28+/-1.74 % from 30 to 500 microgram of potassium feldspar. 5) The concentration of respirable dust in Taebaek area was 4.90+/-3.29 mg/m3(0.4-93.7%), percent quartz was 1.80+/-4.14% (0.01-20.56%), percent sericite was 11.37+/-6.43% (0.00-29.69%), percent potassium feldspar was 8.15 % (n=7, 3.41-19.70%). 6) The difference of respirable coal dust, quartz, and sericite concentration in drilling, coal cutting, hauling and separating was significant respectively (p<0.05).
Absorption
;
Coal
;
Dust*
;
Fourier Analysis*
;
Minerals
;
Potassium
;
Quartz*
;
Spectrophotometry, Infrared*
2.The comparative study of distortion of untreated cartilages and lyophilized cartilages.
Doo Young OH ; Jeong Hoon KANG ; Hae Cheon CHOI ; Kun Chul YOON
Journal of the Korean Society of Plastic and Reconstructive Surgeons 1998;25(6):949-954
Human untreated costal cartilage was compared with lyophilized human costal cartilage which was treated with defatting solution for 48 hours and freeze drying for 72 hours (-70degree C, 10??bar) on the tendency of distortion. All cartilages, which were taken from six cadavers, were carved 5x5x30mm in size on principle of the balanced cross section. Their distortions were evaluated by two methods at intervals of one week, one month, three months, six months after experiment. At first, the degree of distortion was grossly graded with four steps: grade O; no distortion / grade I; minimal distortion / grade II; moderate distortion / grade III; severe distortion. Second method is measurement and quantification of distortion in the horizontal and vertical plane of cartilage.Untreated cartilage is shown to be an unsatisfactory material, with only three(12%) of the 25 cartilages being cosmetically acceptable(grade 0 and 1) after 6 months. In lyophilized cartilage, 18(94%) of the 19 cartilages were cosmetically acceptable(grade 0 and 1) at 6 months. This figure is highly significant(p<0.01). In another method, distortion in the horizontal(h) and vertical (v) planes of cartilage were measured, and mean values of ???? were calculated. In untreated group, the mean values of ???? were 0.82 at 1 week, 0.91 at 1 month, 1.13 at 3 months, and 1.31 at 6 months. In lyophilized group, the mean values were 0.27 at 1 week, 0.29 at 1 month, 0.40 at 3 months and 0.47 at 6 months. All values were statistically significant(p<0.01).
Cadaver
;
Cartilage*
;
Freeze Drying
;
Humans
3.Quartz Concentration and Respirable Dust of Coal Mines in Taeback and Kangneung Areas.
Ho Chun CHOI ; Yong Hee CHEON ; Young No YOON ; Hae Jeong KIM
Korean Journal of Preventive Medicine 1987;20(2):261-269
In order to investigate working conditions of underground coal mines, this work was undertaken to evaluate the respirable dust and the concentration of quartz in Taeback and Kangneung areas. The concentration of quartz was determined by Fourier Transform Infrared Spectrophotometry. The results were as follows; 1) The concentration of respirable dust of drilling and coal face in Taeback and Kangneung areas were as followed. 2) Distribution of respirable dust was well fitted to the long-normal distribution and geometric mean value was log(-1) 0.37+/-log(-1) 0.47 (2.34+/-2.95) mg/m3. 3) The difference of respirable dust concentrations in Taeback and Kangneung areas was not significant statistically (p>0.05). 4) The concentration of quartz of drilling and coal face in Taeback and Kangneung areas were as followed. 5) Distribution of quartz concentrations was well fitted to the log-normal distribution and geometric mean value was log(-1) 0.33+/-log(-1) 0.45 (2.14+/-2.82)%. 6) The difference of quartz concentrations in Taeback and Kangneung areas was not significant (p>0.05), but significant at drilling sites and coal faces (p<0.05).
Coal*
;
Dust*
;
Fourier Analysis
;
Gangwon-do*
;
Quartz*
;
Spectrophotometry, Infrared
4.Effects of age, sex, and body mass index on sudomotor and cardiovagal functions in a healthy Korean population
Heejeong Jeong ; Ki-Jong Park ; Heeyoung Kang ; Nack-Cheon Choi ; Oh-Young Kwon ; ByeongHoon Lim
Neurology Asia 2016;21(3):255-260
Background: Hypertension results from an impaired baroreceptor reflex and enhanced sympathetic
activity. The prevalence of hypertension differs among ethnicities and is more frequent in South Asians
than in Caucasians, suggesting that baseline autonomic nervous system functions and their regulation
may also differ among ethnic groups. In most studies, the reference values for clinical autonomic
function tests are obtained from heterogeneous ethnic populations, or ethnic factors are not considered
in the study design. Obtaining reference data in a homogenous ethnic group and comparing them within
various ethnic groups could be helpful to detect ethnic differences in autonomic functions. The aim of
this study was to identify normative reference values for standard autonomic reflex measurements in
a homogeneous Korean population. Methods: A total of 181 healthy Korean volunteers (age, 20–74
years) underwent standard autonomic function tests: heart rate difference during deep breathing,
Valsalva maneuver, and the quantitative sudomotor axon-reflex test. Mean and 5th and 95th percentile
values were obtained for each age group. We also analyzed factors (age, sex, and body mass index)
that can influence autonomic functions. Results: The heart rate difference during deep breathing and
expiratory-inspiratory ratio were higher in males than in females and were inversely related to age.
The Valsalva ratio was inversely related to age. Males had higher sweat volumes at all body areas
evaluated than those of females, and only forearm sweat volume was significantly different between
the age groups.
Conclusions: Cardiovagal function was affected by age and sex in Koreans. Sudomotor function was
affected by sex, and only forearm sweat volume was affected by age and sex. These results represent
preliminary normative clinical autonomic data in a Korean population comprised of a single ethnicity
Hypertension
5.Foreign-body granuloma formation in the lower eyelid after injection of poly-D,L-lactic acid as a collagen stimulator: a case report
Min CHOI ; Woo Young CHOI ; Jun Mo KIM ; Ji Seon CHEON ; Jeong Yeol YANG
Archives of Aesthetic Plastic Surgery 2024;30(4):137-140
Poly-D,L-lactic acid (PDLLA) is widely used in facial rejuvenation as a collagen stimulator, with a lower risk of granuloma formation compared to poly-L-lactic acid (PLLA). However, granulomas may still occur. In this case, a 58-year-old woman developed firm, non-tender, bilateral infraorbital granulomas 2 months after her third PDLLA injection for infraorbital hollowing. The lesions were unresponsive to intralesional trichloroacetic acid (TCA) and intense pulsed light therapy, necessitating surgical removal. Histopathological analysis confirmed foreign-body granulomas caused by the PDLLA filler. This case highlights the need for caution when injecting PDLLA into thin-skinned areas like the infraorbital region, where granulomas can be more visible due to limited tissue volume. Although PDLLA fillers are generally safe, granuloma formation remains a potential complication. Early diagnosis and treatment with non-surgical methods, such as intralesional TCA, should be prioritized. If these methods fail, surgical excision, aimed at preserving as much normal tissue as possible, may be necessary for optimal outcomes.
6.Foreign-body granuloma formation in the lower eyelid after injection of poly-D,L-lactic acid as a collagen stimulator: a case report
Min CHOI ; Woo Young CHOI ; Jun Mo KIM ; Ji Seon CHEON ; Jeong Yeol YANG
Archives of Aesthetic Plastic Surgery 2024;30(4):137-140
Poly-D,L-lactic acid (PDLLA) is widely used in facial rejuvenation as a collagen stimulator, with a lower risk of granuloma formation compared to poly-L-lactic acid (PLLA). However, granulomas may still occur. In this case, a 58-year-old woman developed firm, non-tender, bilateral infraorbital granulomas 2 months after her third PDLLA injection for infraorbital hollowing. The lesions were unresponsive to intralesional trichloroacetic acid (TCA) and intense pulsed light therapy, necessitating surgical removal. Histopathological analysis confirmed foreign-body granulomas caused by the PDLLA filler. This case highlights the need for caution when injecting PDLLA into thin-skinned areas like the infraorbital region, where granulomas can be more visible due to limited tissue volume. Although PDLLA fillers are generally safe, granuloma formation remains a potential complication. Early diagnosis and treatment with non-surgical methods, such as intralesional TCA, should be prioritized. If these methods fail, surgical excision, aimed at preserving as much normal tissue as possible, may be necessary for optimal outcomes.
7.Foreign-body granuloma formation in the lower eyelid after injection of poly-D,L-lactic acid as a collagen stimulator: a case report
Min CHOI ; Woo Young CHOI ; Jun Mo KIM ; Ji Seon CHEON ; Jeong Yeol YANG
Archives of Aesthetic Plastic Surgery 2024;30(4):137-140
Poly-D,L-lactic acid (PDLLA) is widely used in facial rejuvenation as a collagen stimulator, with a lower risk of granuloma formation compared to poly-L-lactic acid (PLLA). However, granulomas may still occur. In this case, a 58-year-old woman developed firm, non-tender, bilateral infraorbital granulomas 2 months after her third PDLLA injection for infraorbital hollowing. The lesions were unresponsive to intralesional trichloroacetic acid (TCA) and intense pulsed light therapy, necessitating surgical removal. Histopathological analysis confirmed foreign-body granulomas caused by the PDLLA filler. This case highlights the need for caution when injecting PDLLA into thin-skinned areas like the infraorbital region, where granulomas can be more visible due to limited tissue volume. Although PDLLA fillers are generally safe, granuloma formation remains a potential complication. Early diagnosis and treatment with non-surgical methods, such as intralesional TCA, should be prioritized. If these methods fail, surgical excision, aimed at preserving as much normal tissue as possible, may be necessary for optimal outcomes.
8.Foreign-body granuloma formation in the lower eyelid after injection of poly-D,L-lactic acid as a collagen stimulator: a case report
Min CHOI ; Woo Young CHOI ; Jun Mo KIM ; Ji Seon CHEON ; Jeong Yeol YANG
Archives of Aesthetic Plastic Surgery 2024;30(4):137-140
Poly-D,L-lactic acid (PDLLA) is widely used in facial rejuvenation as a collagen stimulator, with a lower risk of granuloma formation compared to poly-L-lactic acid (PLLA). However, granulomas may still occur. In this case, a 58-year-old woman developed firm, non-tender, bilateral infraorbital granulomas 2 months after her third PDLLA injection for infraorbital hollowing. The lesions were unresponsive to intralesional trichloroacetic acid (TCA) and intense pulsed light therapy, necessitating surgical removal. Histopathological analysis confirmed foreign-body granulomas caused by the PDLLA filler. This case highlights the need for caution when injecting PDLLA into thin-skinned areas like the infraorbital region, where granulomas can be more visible due to limited tissue volume. Although PDLLA fillers are generally safe, granuloma formation remains a potential complication. Early diagnosis and treatment with non-surgical methods, such as intralesional TCA, should be prioritized. If these methods fail, surgical excision, aimed at preserving as much normal tissue as possible, may be necessary for optimal outcomes.
9.Age, hypertension, and genetic polymorphisms and their relative associations with white matter hyperintensities in Korean patients with Alzheimer’s disease
Heejeong Jeong ; Seungnam Son ; Soo-Kyoung Kim ; Ki-Jong Park ; Nack-Cheon Choi ; Oh-Young Kwon ; Byeonghoon Lim ; Heeyoung Kang
Neurology Asia 2015;20(1):35-41
Objectives: White matter hyperintensities are known to influence dementia in Alzheimer’s disease.
Genetic components are suggested as putative risk factors for vascular pathology and cognitive
decline. This study aimed to determine whether there is an association between candidate genetic
polymorphisms and the severity of white matter hyperintensities in patients with Alzheimer’s disease.
Methods: Seventy-five patients diagnosed with Alzheimer’s disease underwent genetic tests for specific
alleles of apolipoprotein E, angiotensin-converting enzyme, and methylenetetrahydrofolate reductase.
All patients underwent brain magnetic resonance imaging scans and neuropsychological tests. The
severity of white matter hyperintensities was semiquantified using the CREDOS rating scale, and
patients were divided into three groups according to their rating. Results:The severity of white matter
hyperintensities was related to age and hypertension. However, none of the gene polymorphisms we
tested was found to be associated with the severity of white matter hyperintensities.
Conclusion:The genetic polymorphisms found in apolipoprotein E, angiotensin-converting enzyme
and methylenetetrahydrofolate reductase did not contribute to white matter hyperintensities in
Alzheimer’s disease.Only age and hypertension factors were found to be contributory to white matter
hyperintensities.
Alzheimer Disease
;
Dementia
10.Cytogenetic Radiation Adaptive Response Assessed by Metaphase Analysis and Micronuclei Test in Human Lymphocytes and Mouse Bone Marrow Cells.
Ji Yeul KIM ; Hee Seung BOM ; Jung Jun MIN ; Ho Cheon SONG ; Keun Hee CHOI ; Hwan Jeong JEONG ; Seung Yeon LEE
Korean Journal of Nuclear Medicine 1998;32(6):525-533
PURPOSE: Radiation adaptive response in human peripheral lymphocytes and mouse bone marrow cells was investigated using both metaphase analysis and micronucleus assay. We assessed the correlation between both tests. MATERIALS AND METHODS: Two groups of the human peripheral lymphocytes and mouse bone marrow cells were exposed to low dose (conditioning dose, 0.18 Gy) or high dose (challenging dose, 2 Gy) gamma-rays. The other 4 groups were exposed to low dose followed by high dose after several time intervals (4, 7, 12, and 24 hours, respectively). The frequencies of chromosomal aberrations in metphase analysis and micronuclei in micronucleus assay were counted. RESULTS: Chromosomal aberrations and micronuclei of preexposed group were lower than those of the group only exposed to high dose radiation. Maximal reduction in frequencies of chromosomal aberrations were observed in the group to which challenging dose was given at 7 hour after a conditioning dose (p<0.001). Metaphase analysis and micronucleus assay revealed very good correlation in both human lymphocytes and mouse bone marrow cells (r=0.98, p<0.001; r=0.99, p=0.001, respectively). CONCLUSION: Radiation adaptive response could be induced by low dose irradiation in both human lymphocytes and mouse bone marrow cells. There was a significant correlation between metaphase analysis and micronucleus assay
Animals
;
Bone Marrow Cells*
;
Bone Marrow*
;
Chromosome Aberrations
;
Cytogenetics*
;
Humans*
;
Lymphocytes*
;
Metaphase*
;
Mice*
;
Micronucleus Tests