Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2–4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30–150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0–44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2–4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30–150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0–44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

Various cell types in higher multicellular organisms are genetically homogenous, but are functionally and morphologically heterogeneous due to the differential expression of genes during development, which appears to be controlled by epigenetic mechanisms. However, the exact molecular mechanisms that govern the tissue-specific gene expression are poorly understood. Here, we show that dynamic changes in histone modifications and DNA methylation in the upstream coding region of a gene containing the transcription initiation site determine the tissue-specific gene expression pattern. The tissue-specific expression of the transgene correlated with DNA demethylation at specific CpG sites as well as significant changes in histone modifications from a low ratio of methylated H3- lysine 4 or acetylated H3-lysine 9, 14 to acetylated H4 to higher ratios. Based on the programmed status of transgene silenced in cloned mammalian ear-derived fibroblasts, the transgene could be reprogrammed by change of histone modification and DNA methylation by inhibiting both histone deacetylase and DNA methylation, resulting in high expression of the transgene. These findings indicate that dynamic change of histone modification and DNA methylation is potentially important in the establishment and maintenance of tissue-specific gene expression.
Transgenes/*genetics ; Swine ; Organ Specificity/genetics ; Methylation ; Lysine/*metabolism ; Histones/*metabolism ; Histone Deacetylases/metabolism ; Gene Silencing ; *Gene Expression ; Fibroblasts ; Ear ; *DNA Methylation ; Cells, Cultured ; Animals, Genetically Modified ; Animals ; Acetylation

BACKGROUND: Various eccrine tumors are rather common diseases in clinicians. However, data on the clinicopathologic features of eccrine tumors in Korea are limited. OBJECTIVE: The purpose of this study was to investigate the clinicopathologic characteristics of eccrine tumors in Korea. METHODS: Two hundred and sixty five cases of eccrine tumors, seen from 2002 to 2004 in Korea, were retrospectively analyzed clinically and histopathologically. RESULTS: The most common eccrine tumors identified within Koreans were syringoma (61%), followed by eccrine poroma (13%), eccrine hidrocystoma (9%), and nodular hidradenoma (6%). Moreover, eccrine tumors were usually found to occur in middle-aged woman as multiple asymptomatic skin-colored papules. The most common site of occurrence was the face (45%), followed by the neck (9%), scalp (5%), foot (5%), abdomen (4%), and vulvar (3%). CONCLUSION: The results of this study will be useful and fundamental data on eccrine tumors for clinicians and pathologists.
Abdomen ; Acrospiroma ; Female ; Foot ; Hidrocystoma ; Humans ; Korea ; Neck ; Poroma ; Retrospective Studies ; Scalp ; Syringoma

BACKGROUND AND OBJECTIVES: Right-sided infective endocarditis (RtIE) occurs in about 5-10% of total infective endocarditis cases. In western countries, many cases of RtIE are related to drug addiction. However, there been only scant reports of right-sided infective endocarditis in Korea. The aim of the study was to identify the clinical characteristics of RtIE, such as frequency, predisposing risk factors, causative organisms and in-hospital mortality in Korea. SUBJECTS AND METHODS: All episodes diagnosed as infective endocarditis, between 1989 and 2003, at the Asan Medical Center were retrospectively reviewed using Duke's criteria. A total of 308 patients were diagnosed as infective endocarditis. RESULTS: RtIE was found in 34 patients (11.0%), with a mean age of 44.1+/-15.0 years. Fifteen patients had congenital heart diseases. However, several in-hospital invasive procedures and skin injuries were the most common predisposing risk factors in patients with uncorrected congenital heart disease (group A), whereas unknown causes were most common in patients without uncorrected congenital heart disease (group B). The most common causative organisms in groups A and B were Streptococcus viridans (6/15, 40%) and Staphylococcus aureus (13/19, 68.4%), respectively. In group A, the location of vegetations was variable according to the turbulent flow, but was exclusively at the tricuspid valve in group B. There were 6.7% (1/15) and 26.3% (5/19) inhospital mortalities in groups A and B, respectively (p=0.196). CONCLUSION: No drug addict with RtIE was seen. The most important predisposing risk factor in patients with RtIE was the presence of uncorrected congenital heart disease. The predisposing risk factors, causative organisms and the locations of vegetation in patients with RtIE differed according to the patient's uncorrected congenital heart disease.
Chungcheongnam-do ; Endocarditis* ; Endocarditis, Bacterial ; Heart Defects, Congenital ; Heart Diseases ; Hospital Mortality ; Humans ; Korea* ; Retrospective Studies ; Risk Factors ; Skin ; Staphylococcus aureus ; Substance-Related Disorders ; Tricuspid Valve ; Viridans Streptococci

BACKGROUND AND OBJECTIVES: Chronobiological rhythms have been shown to influence the occurrence of a variety of cardiovascular disorders, including acute myocardial infarction (AMI). The present study investigated whether the onset of acute aortic syndrome (AAS) has unique chronobiological rhythms in Korean populations. SUBJECTS AND METHODS: The clinical data of 371 consecutive AAS patients, admitted between 1993 and 2003, were retrospectively analyzed; 310 AMI patients, who underwent primary percutaneous angioplasty in the hyperacute phase between 1998 and 2001, were also selected. RESULTS: In the AAS group, the final diagnoses were aortic dissection (AD) and aortic intramural hematoma (AIH) in 212 and 159 patients, respectively Similar to AMI, AAS showed a significantly higher occurrence from 6 AM to noon compared with other time periods (p=0.0013). AAS showed a second peak occurrence from 6 PM to midnight, which was not observed in the AMI group. A subgroup analysis revealed that younger patients (age < 60 years) and those with a past medical history of hypertension had the highest occurrence from 6 PM to midnight, which was quite different compared to the AAS patients. No significant variation was found for the day of the week in either group. Although no significant seasonal variation was observed in the frequency of AMI, the frequency of AAS was significantly higher during winter (p<0.001). The circadian and seasonal variations in the frequency of AIH were similar to those of AD. CONCLUSION: AAS shows unique circadian and seasonal variations in Korean populations. Our findings may have implications for the prevention of AAS by tailoring treatment strategies to ensure maximal benefits during the vulnerable periods.
Angioplasty ; Circadian Rhythm ; Diagnosis ; Hematoma ; Humans ; Hypertension ; Myocardial Infarction* ; Retrospective Studies ; Seasons

BACKGROUND: The relative frequency and clinicopathologic characteristics of lymphomas vary according to geography and race. Data on the features of cutaneous lymphoma in Korea are limited. OBJECTIVE: The aim of this study was to document the relative occurrence, the clinical and histopathological features of cutaneous lymphomas in Korea. METHODS: The Korean Dermatopathology Research Group conducted a review of nationwide collection of 80 cutaneous lymphomas, diagnosed at 23 institutes over recent 3-year period. Clinical records and pathology slides of the patients were reviewed retrospectively. RESULTS AND CONCLUSION: Korea has a higher rate of T-cell lymphoma and NK/T cell lymphoma and a much lower rate of cutaneous B cell lymphoma. The relative frequency of the major diagnostic group according to WHO classification was as follows: mycosis fungoides/Sezary syndrome, 42.5%; anaplastic large cell lymphoma, 19%; nasal and nasal type NK/T cell lymphoma, 15%; subcutaneous panniculitis-like T cell lymphoma, 11%; peripheral T cell lymphoma, unspecified, 7.5%; follicular lymphoma, 3%; marginal zone lymphoma, 1%; angioimmunoblastic lymphadenopathy, 1%. Compared with Western countries, the rate of nasal and nasal-type NK/T cell lymphoma and subcutaneous panniculitis-like T cell lymphoma were much higher. Therefore, The EORTC classification is not effective in dealing with Korean cases of cutaneous lymphoma. We consider the principles of the WHO classification are applicable to the Korean cases of cutaneous lymphoma.
Academies and Institutes ; Classification ; Continental Population Groups ; Geography ; Humans ; Immunoblastic Lymphadenopathy ; Korea* ; Lymphoma* ; Lymphoma, B-Cell ; Lymphoma, Follicular ; Lymphoma, Large-Cell, Anaplastic ; Lymphoma, T-Cell ; Lymphoma, T-Cell, Peripheral ; Pathology ; Retrospective Studies

BACKGROUND: Malignant melanoma in Korea has been increasing as in other countries, but there is no nationwide survey of malignant melanoma in Korea. OBJECTIVE: The aim of this study was to document the clinical and histopathological features of cutaneous melanoma in Korea. METHODS: The Dermatopathology Research Group conducted a review of nationwide collection of 109 primary cutaneous melanomas, diagnosed at 23 institutes over a recent 3-year period. Clinical records and pathology slides of the patients were reviewed retrospectively. RESULTS AND CONCLUSION: The peak age was the 7th decade with the mean age of 58.1 years. Korea has a higher rate of acral melanoma and much lower rate of lentigo maligna melanoma. .Major component tumor cell was spindle cell type. Clark level of tumor was III or more and Breslow depth was 2mm or more at the time of the first diagnosis in many cases (62%). Pre-existing melanocytic nevus was present in a few cases (3 cases). All these features suggest that the racial difference between the Korean and the Caucasian is evident. We also suggest that an early detection program is very important to cure this malignant tumor.
Academies and Institutes ; Diagnosis ; Humans ; Hutchinson's Melanotic Freckle ; Korea* ; Melanoma* ; Nevus, Pigmented ; Pathology ; Retrospective Studies

BACKGROUND: Data on the clinicopathologic features of hair follicle tumors in Korea are limited. OBJECTIVE: The purpose was to investigate the clinical and histopathologic characteristics of hair follicle tumors in Korea. METHODS: Two hundred sixty four cases of hair follicle tumors seen from 1999 to 2001 in Korea were analyzed clinically and histopathologically. RESULTS AND CONCLUSION: The most common hair follicle tumor in Korea was pilomatricoma(81.0%), followed by trichoepithelioma(6.4%), dilated pore of Winer(3.8%), and proliferating trichilemmal tumor(2.2%). Hair follicle tumors usually occurred as a solitary skin-colored nodule. The most commonly involved site was the face, and the peak age of presentation was 10 to 19. Pilomatricoma usually occurred as a solitary skin-colored nodule. The most commonly involved site was the arm, and more than 50% of tumors occurred before the age of 20. Histopathologically, the tumor was often surrounded by fibrous capsule and was composed of basophilic and shadow cells. It was usually located in the dermis and extended into the subcutis. Retraction spaces between tumor nests and stroma were frequently observed. Trichoepithelioma usually occurred as multiple skin-colored papules on the face. Histopathologically, the tumor was usually located in the dermis with sometimes connected to the epidermis. It frequently showed peripheral palisading. Dilated pore of Winer usually occurred as a solitary brownish to pigmented papule on the face in middle-aged persons. Proliferating trichilemmal tumor occurred as a solitary or multiple tumors. Histopathologically, the tumor was usually surrounded by incomplete fibrous capsule. Tumor cells frequently showed clear cell formation, nuclear atypia, mitosis, peripheral palisading, trichilemmal keratinization, and individual keratinization.
Arm ; Basophils ; Dermis ; Epidermis ; Hair Follicle* ; Hair* ; Humans ; Korea ; Mitosis ; Pilomatrixoma

Drug Information Centers are responsible for providing updated, relevant drug information on the efficacy, safety and quality of drugs as well as disease status to health-care practitioners and finally to patients. This study was designed to revise the drug information service based on the evaluation to meet the social requirement that is created by the recent "Drug Prescription and Dispensing Law" A retrospective analysis was conducted from April 1997 untill September 2000. To evaluate the trend of service, the evaluated period was divided in 7 6-months intervals. The feedback system was used to measure the satisfaction score as an outcome. Out of 618 total enquiries, 192 (31.0%) was received in the last 6-month period. The method of receiving and providing drug information by Drug Information Research Institute (DIRI) gradually changed from telephone calls to e-mailing system (2.2% vs. 67.2% in question, 2.2% vs. 70.3% in answer). Drug information questions concerning the pharmacology (18.8%), adverse drug reaction (10.5%), availability (10.3%) and drug interaction (5.2%) were asked most frequently. The median time to respond the inquired questions was 24 hours (range: 1 hr-8 days). The reference used most frequently to answer was the tertiary literature (42.0%) followed by the second literature (27%) and primary literature (7%). The evaluable 29 feedbacks showed that DI services provided by DIRI were satisfactory in accuracy and time. On the basis of the analysis and evaluation of this project, DIRI have developed the more specified Q and A Sheet Form, systemic database and on-line Q and A corner accessible through the homepage.
Academies and Institutes ; Drug Information Services* ; Drug Interactions ; Drug-Related Side Effects and Adverse Reactions ; Electronic Mail ; Humans ; Information Centers* ; Pharmacology ; Prescriptions ; Retrospective Studies ; Telephone