BACKGROUND: The distribution of Malassezia yeasts on normal human skin was varied according to the age and race of the volunteers and the methodologies used. In Korea, most reports of Malassezia yeast distribution have relied on direct skin smears rather than culture methods. OBJECTIVE: The aim of this work was to perform a comprehensive survey of the distribution of Malassezia yeasts on normal human skin to provide a base line for a companion study of Malassezia yeasts in patients with various dermatoses. METHODS: Malassezia yeasts were cultured using the swabbing technique from the scalp, forehead, chest, upper back, upper arm and upper thigh in 137 subjects, infancy to 80 years of age. RESULTS: Malassezia yeasts were present in the lowest incidence(0-30%) on six sites of infants and present in 60.0-66.7% on the sebum-rich sites (scalp, forehead, chest, upper back) of children aged 1-9. Malassezia yeasts were present in 80.0-86.7% on the sebum-rich sites of the elderly group(over 60 years of age), about the same frequency as in the middle-aged groups. The population density of these organisms was significantly higher on the upper back than on the forehead, chest, upper arm and upper thigh in all age groups except the infant group and the group aged 1 to 9 (p<0.05). There were no regular quantitative variations in the distribution of Malassezia yeasts on a given site between age groups. On Leeming and Notman media, besides three morphotypes of Malassezia yeasts reported by Cunningham et al(1990), one additional type was identified. CONCLUSION: The results showed regional variations in the distribution of Malassezia yeasts in all ages except infancy and no regular age variations on a given site. Additionally, four colony types of Malassezia yeasts were found. The findings of our study coold help to investigate the role of Malassezia yeasts in related disorders.
Aged ; Arm ; Child ; Continental Population Groups ; Forehead ; Friends ; Humans* ; Infant ; Korea ; Malassezia* ; Population Density ; Scalp ; Skin Diseases ; Skin* ; Thigh ; Thorax ; Volunteers ; Yeasts*

BACKGROUND: Cutaneous vasculitis associated with viral hepatitis seems to occur as a hypersensitivity reaction against the circulating viral antigens. Hepatitis B virus(HBV)-encoded X antigen(HBxAg) is known to participate in the carcinogenesis of hepatocellular carcinoma(HCC) by the inactivation of p53. However, HBxAg has been found in chronic infiammatory lesions without the overexpression of p53. Accordingly, not only EBsAg and HBcAg but also HBxAg may be involved in HCC-associated cutaneous vasculitis, regardless of the alteration of p53. OBJECTIVE: This study was conducted to investigate the expression of HBV-encoded antigens in cutaneous vasculitis accompanied by HBV hepatopathy. Additionally, we have compared the expression of 3 HBV antigens and p53 between vasculitic patients with HCC and in others showing HCC-non-associated vasculitis. METHODS: Immunohistochemically, we examined the expression of HBsAg, HBcAg, and HBxAg in the tissue specimens taken from the vasculitic lesions of the 33 HBsAg-positive enrolled patients with cutaneous vasculitis proven by skin biopsy. RESULTS: 1. The immunohistochemical positivity rate to HBsAg in vasculitic patients with HBV hepatopathy was 66.7% overall. It was 90% in HCC-associated vasculitic subjects and 56.5% in the vasculitic subjects without HCC, respectively. 2. We found the expression of HBxAg in 80% of the vasculitic subjects showing HCC. The vasculitic patients without HCC showed 17,3% of the positivity rate to HBxAg. 3. We could not find the overexpression of p53 in the vasculitic tissue specimens of the HCC patients without the cutaneous metastasis from primary HCC. CONCLUSION: HBsAg, HBcAg and HBxAg may participate in the pathogenesis of cutaneous vasculitis with HBV hepatopathy, regardless of tumorigenesis.
Antigens, Viral ; Biopsy ; Carcinogenesis ; Hepatitis ; Hepatitis B ; Hepatitis B Core Antigens ; Hepatitis B Surface Antigens ; Humans* ; Hypersensitivity ; Malassezia* ; Neoplasm Metastasis ; Skin* ; Vasculitis ; Yeasts*

No abstract available.
Lipoma* ; Neck*

This study was performed to evaluate the effect of bone graft materials including demineralized freeze-dried bone, freeze-dried bone, deproteinized bovine bone on space-making capacity and bone formation in guided bone regeneration with titanium reinforced ePTFE membrane(TR-ePTFE). Adult male rabbits(mean BW 2kg) were used in this study. Intramarrow penetration defects were surgically created with round bur on calvaria of rabbits. TR-ePTFE membrane was adapted to calvarial defect and bone graft materials were placed. Animals were sacrificed at 2, 8, 12 weeks after surgery. Non-decalcified specimens were processed for histologic analysis and prepared with Villaneuva bone stain. The results of this study were as follows: 1. TR-ePTFE membrane was biocompatible and capable of maintaining the space-making. 2. Tissue integration was not good at TR-ePTFE membrane. Fixation was not enough. so, wound stabilization was not good. 3. In animals using deproteinized bovine bone, demineralized freeze-dried bone, bone formation was little. 4. In animals using freeze-dried bone, bone formation was better. Within the above results, bone formation may be inhibited when wound stabilizafion was not good.
Adult ; Male ; Female ; Humans ; Rabbits ; Animals

The present study was performed to evaluate the effect of tetracycline-HCL on the change of implant surface microstructure according to application time. Implant with pure titanium machined surface, HA-coated surface and TiUniteTM surface were utilized. Implant surface was rubbed with 50mg/ml tetracycline-HCL solution for 1/2min., 1min., 1 1/2min., 2min., and 2 1/2min. respectively in the test group. Then, specimens were processed for scanning electron microscopic observation. The results of this study were as follows. 1. Both test and control group showed a few shallow grooves and ridges in pure titanium machined surface implants. There were not significant differences between two groups. 2. In HA-coated surfaces, round particles were deposited irregularly. The roughness of surfaces conditioned with tetracycline-HCL was lessened and the cracks were increased relative to the application time. 3. The anodic oxidized surfaces showed the craterous structures. The surface conditioning with tetracycline-HCl didn't influence on its micro-morphology. In conclusion, the detoxification with 50mg/ml tetracycline-HCL must be applied respectively with different time according to various implant surfaces.
Titanium

Coronavirus disease 2019 (COVID-19) is a new type of epidemic infectious disease that threatens the world after it first broke out in Wuhan, China, in December 2019. By early March, Korea had the second largest number of confirmed cases of COVID-19 in the world after China, among which about 90% of patients reported in Daegu and Gyeongsangbuk-do province. As a neurologist, the author experienced various neurological diseases while working at hub-hospitals for COVID-19 in Daegu. I would like to describe the role of a neurologist in the emerging outbreak of infectious diseases, along with my experience working at the hub-hospital for Middle East Respiratory Syndrome (MERS) in 2015.