OBJECTIVES: In large-scale field trials, randomization by cluster is frequently used because of the administrative convenience, a desire to reduce the effect of treatment contamination, and the need to avoid ethical issues that might otherwise arise. Cluster randomization trials are experiments in which intact social unit, e.g., families, schools, cities, rather than independent individuals are randomly allocated to intervention groups. The positive correlation among responses of subjects from the same cluster is in matter in cluster randomization. This thesis is to compare the results of three randomization methods by standard error of estimator of treatment effect. METHODS: We simulated cholesterol data varing the size of the cluster and the level of the correlation in clusters and analyzed the effect of cholesterol-lowering agent. RESULTS: In intra-cluster randomization the standard error of the estimator of treatment effect is smallest relative to that in inter-cluster randomization and that in individual randomization. CONCLUSIONS: Intra-cluster randomization is the most efficient in its standard error of estimator of treatment effect but other factor should be considered when selecting a specific randomization method.
Cholesterol ; Ethics ; Humans ; Random Allocation*

The objective of the study was to observe the effect of n-3 PUFA on cell proliferation and apoptosis by determining mRNA and protein of COX-2 and eicosanoid product and the mRNA and protein of Bu and Bcl-2 related to apoptosis in colon carcinogenesis of 1,2- dimethylhydrazine (DMH)-treated rats. Ninety male Sprague Dawley rats weighing about 170g were divided into 3 groups, control and n-3 PUFA supplemented groups (FO group: 6.2 mmoles n-3 PUFA; 2FO group: 12.4 mmoles n-3 PUFA) and fed experimental diet for 14 weeks. All rats were intramuscularly injected with DMH 15 mg/kg twice a week for 6 weeks to deliver total dose of 180 mg/kg body weight. Compared with the control group, 6.2 mmoles n-3 PUFA significantly reduced the levels of mRNA and protein expression of COX-2 and 2-series eicosanoids (TXB2 and PGE2 and decreased cell proliferation in colonic mucosa. However, high levels of n-3 PUFA supplementation significantly increased the levels of mRNA and protein expression of COX-2, TXB2 and PGE2. and increased cell proliferation which was similar level to that of control group. Compared with the control group, n-3 PUFA, regardless of the amount, significantly increased apoptotic index in colonic mucosa. Western blot and RT-PCR analyses showed that the levels of mRNA and protein expression of Bax were significantly increased by 6.2 mmoles n-3 PUFA, but decreased by 12.4 mmoles n-3 PUFA. The analyses also showed the levels of mRNA and protein expression of Bcl-2 were significantly reduced by 6.2 mmoles n-3 PUFA, but increased by 12.4 mmoles n-3 PUFA. The ratio of Bcl-2/Bax in mRNA and protein was significantly reduced by 6.2 mmoles n-3 PUFA but increased by 12.4 mmoles n-3 PUFA. Overall, these results indicate that n-3 PUFA could be effective in preventing colon carcinogenesis by reducing cell proliferation with lower level of COX-2 and 2-series eicosanoid, and increasing apoptosis by inducing pro-apoptotic gene, Bax and inhibiting anti-apoptotic gene, Bcl-2 in the colonic mucosa of DMH-treated rats. However, high level of n-3 PUFA supplementation could stimulate colon carcinogenesis by increasing cell proliferation and inhibiting apoptosis.
Animals ; Apoptosis ; Blotting, Western ; Body Weight ; Carcinogenesis* ; Cell Proliferation ; Colon* ; Control Groups ; Diet ; Dimenhydrinate ; Dinoprostone ; Eicosanoids ; Fatty Acids, Omega-3* ; Genes, bcl-2 ; Humans ; Male ; Mucous Membrane ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger

Varicella is usually considered to be a benign disease in healthy children; however, serious complications can occur such as necrotizing fasciitis and toxic shock syndrome. We describe a 38-month-old girl with necrotizing fasciitis and streptococcal toxic shock syndrome following varicella. She was previously healthy and vaccinated against varicella at 12 months of age. She had been diagnosed with varicella three days prior to presenting at our facility; she developed fever, vomiting, and painful swelling on her left flank. Her skin lesions worsened, she became lethargic, and had episodes of hypotension and coagulopathy. Necrotizing fasciitis on the left abdominal wall, buttocks, and left thigh was diagnosed by magnetic resonance imaging, and group A Streptococcus was isolated from a tissue culture. She was diagnosed as necrotizing fasciitis and streptococcal toxic shock syndrome, and successfully treated with repeated surgical debridement and fasciotomy, in addition to intensive antibiotics. Our experience suggests that necrotizing fasciitis in patients with varicella should be considered to be a rare complication even with widespread vaccine use. Early diagnosis and intensive treatment are required to prevent a fatal outcome.
Abdominal Wall ; Anti-Bacterial Agents ; Buttocks ; Chickenpox* ; Child* ; Child, Preschool ; Debridement ; Early Diagnosis ; Fasciitis, Necrotizing* ; Fatal Outcome ; Female ; Fever ; Humans ; Hypotension ; Magnetic Resonance Imaging ; Shock, Septic* ; Skin ; Streptococcus ; Streptococcus pyogenes ; Thigh ; Vomiting

BACKGROUND: Even though several oral anti-diabetic drugs (OAD) with various modes of action are replacing sulfonylurea (SU), some patients seem to be dependent on SU for adequate glycemic control. Therefore, we evaluated the clinical characteristics of such patients. METHODS: We selected the patients with type 2 diabetes who met following criteria from 2009 to 2014 at Seoul National University Hospital: glycated hemoglobin (HbA1c) was maintained below 7.5% for at least 6 months under small dose of SU (glimepiride < or =2 mg/day or equivalent dose); after discontinuation of SU, HbA1c increased > or =1.2% within 3 months or > or =1.5% within 6 months; and after resuming SU, HbA1c reduction was > or =0.8% or reduction of fasting plasma glucose was > or =40 mg/dL within 3 months. Patients with impaired hepatic or renal function, and steroid users were excluded. RESULTS: Nineteen subjects were enrolled: after averaged 4.8+/-1.5 months of SU-free period, HbA1c increased from 6.7%+/-0.4% to 8.8%+/-0.8% even though adding other OAD such as gliptins. However, HbA1c decreased to 7.4%+/-0.7% after resuming SU within 2.4+/-0.8 months. There was no sexual predominance. Despite their old age (67+/-11 years) and long duration of diabetes (18+/-10 years), fasting C-peptide was relatively well-reserved (3.9+/-2.6 ng/mL), and nephropathy was not observed (albumin-creatinine ratio 21.2+/-16.6 mg/g and estimated glomerular filtration rate 75.8+/-18.0 mL/min/1.73 m2). Strong family history was also noted (73.7%). CONCLUSION: Despite hypoglycemia risk of SU, it seemed indispensable for a subset of patients with regard to insulin secretion. Genetic influences would be evaluated.
Blood Glucose ; C-Peptide ; Diabetes Mellitus ; Dipeptidyl-Peptidase IV Inhibitors ; Fasting ; Glomerular Filtration Rate ; Hemoglobin A, Glycosylated ; Humans ; Hypoglycemia ; Insulin ; Seoul

PURPOSE: Eosinophilia may be associated with various primary and reactive conditions. However, studies on the cause and incidence of eosinophilia in Korean children are rare. This study aimed to evaluate the cause and incidence of eosinophilia in patients at a single university hospital. METHODS: We studied 8,285 pediatric patients under the age of 18 years who had eosinophilia at Pusan National University Hospital. Premature and newborn infants were excluded. Eosinophilia was defined as an absolute eosinophil count greater than 450/microL. Eosinophilia was categorized as mild (450-1,500/microL), moderate (1,500-5,000/microL), and severe (>5,000/microL). The underlying conditions of eosinophilia were retrospectively investigated. RESULTS: Of 8,285 patients who had a hematology profile, 497 (5.9%) were found to have eosinophilia. Of patients with eosinophilia, 333 patients (67.0%) had identifiable and possible causes. The major causes of eosinophilia were allergic diseases (61.3%), infectious diseases (19.8%), immunologic diseases (9.0%) and hemato-oncologic disease (5.1%). Immunological disease such as Idiopathic hypereosinophilic syndrome, drug induced hypersensitivity syndrome and Graft-versus-host disease was the common condition with moderate to severe eosinophilia in which eosinophil count in peripheral blood was more than 1,500/microL. CONCLUSION: The most common cause of eosinophilia was allergic disease. Immunological disease was the common condition with moderate to severe eosinophilia.
Busan ; Child* ; Communicable Diseases ; Eosinophilia* ; Eosinophils ; Graft vs Host Disease ; Hematology ; Humans ; Hypereosinophilic Syndrome ; Hypersensitivity ; Immune System Diseases ; Incidence* ; Infant, Newborn ; Retrospective Studies

Purpose: The aim of this study was to examine whether gonadotropin-releasing hormone (GnRH) agonist treatment is effective in preserving final height in patients with central precocious puberty (CPP) or early puberty (EP). Methods: The medical records of 40 patients with CPP and 206 patients with EP who completed GnRH agonist treatment following diagnosis were analyzed retrospectively. Height and height standard deviation (height SDS) scores based on bone age (BA) were measured and calculated at baseline, after treatment completion, and at final follow-up to compare changes within and between groups. Predicted adult height (PAH) was estimated by the height corresponding to height SDS for BA in girls at 18 years 11 months of age based on the growth chart. Results: PAH at baseline did not differ significantly between the CPP group (153.67±4.95) and the EP group (154.77±3.72). In the CPP group, PAH significantly increased at treatment completion (156.01±4.61) and at final follow-up (158.52±6.04) compared to baseline. In the EP group, PAH significantly increased at treatment completion (157.7±3.60) and at final follow-up (159.31±4.26) compared to baseline. The increase in PAH at all timepoints compared to baseline did not significantly differ between the CPP and EP groups. Conclusion Both CPP and EP groups had significantly greater PAH after treatment, with no difference in the amount of increase between groups. These results show that GnRH agonist treatment can help increase final height even in patients diagnosed with EP after the age of 8 years.

A 16-month-old boy had signs of virilization such as penile enlargement and pubic hair since 13 months of age. Hormone evaluation indicated increased levels of 17-OH-progesterone, dehydroepiandrosterone- sulfate (DHEA-S) and testosterone. Initially he was diagnosed as simple virilizing type of congenital adrenal hyperplasia and hydrocortisone was given to him. After 2 months, his penile enlargement continued and we did not find gene mutation for 21-hydroxylase deficiency. Adrenal magnetic resonance imaging revealed a 3.5x2.7x4.4 cm size of adrenal mass consistent with an adrenocortical tumor. The patient underwent surgical excision of the well-encapsulated tumor with normalization of his hormone levels. Childhood adrenocortical tumors are rare and are not well characterized. Surgery is the definitive treatment for adrenocortical tumors and prognosis is often poor. We report a case of adrenocortical tumor in a 16-month-old boy presenting with virilization with review of literature.
Adrenal Cortex Neoplasms ; Adrenal Hyperplasia, Congenital ; Hair ; Humans ; Hydrocortisone ; Infant ; Magnetic Resonance Imaging ; Prognosis ; Steroid 21-Hydroxylase ; Testosterone ; Virilism

The mental health of medical students deserves attention because the problems in students may negatively influence learning ability and create consequences for later adjustment to doctor's role. The purpose of this study is to understand the stress, copying, self-esteem and subjective general well-being of medical students and compare them with other students group (students of law, science and humanities). The results was as follows : First, medical students did not report more stress but they use less copying strategy than other students group. Second, there was no differences in stress, copying, self-esteem and general well-being between high and low academic achievement group in medical students. Futhermore, study-related stress had more close relationship with self-esteem, general well-being. Third, the preparatory course students showed lower score in general well-being, especially health, cheerful-depressive mood domain. These results imply that mental health promotion programmes focused in guiding adjustment for the preparatory course students are helpful. And psychiatric, academic counseling should be made available to them. It can lead to an improvement in our health care delivery system. The need of additional longitudinal research is discussed.
Counseling ; Delivery of Health Care ; Humans ; Jurisprudence ; Learning ; Mental Health ; Students, Medical*

PURPOSE: To determine optimal window settings for measuring the inner diameter of the trachea and both mainbronchi by spiral CT. MATERIALS AND METHODS: Chest PA radiography and spiral CT scanning were performed in ten healthy adult volunteers. Three dimensional images were reconstructed (minimal threshold value : -1000HU ; maximal threshold value : from -200 to -900HU, of 50HU intervals) to measure the inner diameter of the trachea and both main bronchi. The results of 3D spiral CT were compared with those of chest radiography. RESULTS: The inner diameters of the trachea, right main bronchus, left main bronchus-I (1cm below the tracheal carina) and left mainbronchus-II (2cm below the tracheal carina) measured by chest radiograph and 3D spiral CT were not significantly different at maximal threshold values of -400 ~ -550HU, -450 ~ -550HU, -450 ~ -600HU and -500 ~ -600HU, respectively (p>0.05). The differences in the results of the two series were statistically significant at other threshold values however (p<0.05). CONCLUSION: We determined optimal window settings for measuring the inner diameter of the trachea and both main bronchi by spiral CT. The optimal maximal threshold values were somewhat different according to measured sites of the trachea and both main bronchi.
Adult ; Bronchi ; Humans ; Radiography ; Radiography, Thoracic ; Thorax ; Tomography, Spiral Computed* ; Trachea ; Volunteers

PURPOSE: To evaluate differences in regional density of normal lung, as seen on CT, according to respiration and gravity. MATERIALS AND METHODS: The subjects were 15 healthy volunteers, all non-smokers and without previous pulmonary disease. CT scans were obtained at three selected levels through the apex, middle and basal lung at the aortic arch, carina and just above the diaphragm, respectively at both full inspiration (FVC) and full expiration (RV). Within these regions of interest and at the three scanning levels, lung density was measured in the anterior, lateral, and posterior portions of the peripheral lung field. RESULTS: Attenuation of the anterior portion of the lung was lower than that of the posterior portion(p<0.005); average lung attenuation increase from the anterior to the posterior portion was significantly greater during full expiration than full inspiration (p<0.005), and was significantly greater at the base of the lung than at the apex (p<0.005 on expiration, p=0.006 on inspiration). Lung density during inspiration was lower than during expiration (p<0.005); average lung density increase from full inspiration to full expiration was significantly greater in the posterior portion than in the anterior (p<0.005). In the former, the average increase at the base of the lung was greater than at the apex (p=0.007), but in the latter, the average increase at the apex was greater than at thebase (p<0.005). CONCLUSION: In normal lung, respiration and gravity cause regional density changes, as seen on CT, and result in difference of lung attenuation between dependent and nondependent portions and between the apex, middle and base of the lung, according to inspiration and expiration.
Aorta, Thoracic ; Diaphragm ; Gravitation ; Healthy Volunteers ; Lung Diseases ; Lung* ; Respiration ; Tomography, X-Ray Computed