At first, we review a sample size estimation method for log-rank test in survival analysis. Although it is widely used these days, it has a weakness for practical use. We propose a modification method to avoid the weakness.
Sample Size*

This study was designed to evaluate the potential application of MRI in differentiating static blood from thrombus, age-related changes of thrombus and the signal differences of the intravascular thrombus in various pulse sequences. External jugular vein was ligated at both upper and lower ends to form a static blood column, and thrombin was injected into the column to cause venous thrombosis in a total of 15 mongrel dogs. The MR images were obtained with T1-and T2-weighted spin echo and gradient echo techniques, immediately after the formation of static blood and after 2 hour, 1 day, 1 week, 2 weeks and 4 weeks of the formation of thrombus at a 2.0T MR unit. The signal intensities of the thrombus and adjacent muscles were compared stubjectively, and the signal intensity ratio was compared objectively by the measurement of the signal intensities using a cursor. The MRI findings were compared with histologic findings. The signal intensities of static blood were hyperintense in all pulse sequences, and those of 2-hour, 1-day and 1-week-old thrombi were hyperintense in all pulse sequences. The number of experimental thrombi which showed isointensity on T1-and T2-weighted image, and hypointensity on gradient echo image increased as thrombi aged. The signal intensities of 2-week-old thrombus were isointense on T1-weighted image, hyperintense on T2-weighted image, and hypointense on gradient echo image, while those of 4-week-old thrombus were isointense on T1-weighted and T2-weighted image, and hypointense on gradient echo image in most experimental thrombi. There was a tendency to decrease in a signal intensity ratio as thrombi aged on T1-weighted, T2-weighted and gradient echo images(P<0.01) Histologically, thrombus was not formed and lumen was filled with many red blood cells(RBCs) in 2-hour-old specimen, but fibrin mesh was visible and RBCs decreased in number in 1-day-old specimen. In 1-week-old specimen, vessel was contracted and lumen was filled with thombus, RBCs, platelets, many fibrins and capillary-like strucrutes. The histologic findings of 2-week-old thrombus were similar to those of 1-week-old one except calcification. In 4-week-old specimen, vessels were contracted and lumen was obliterated with fibrosis and organization of the thrombus. Therefore, it is possible to diagnose thrombus, and to assess sequential changes of MRI findings of thrombus by using all pulse sequences, and these results can be essential bases for the interpretation of MR images of patients with venous thrombosis.
Animals ; Dogs* ; Fibrin ; Fibrosis ; Humans ; Jugular Veins ; Magnetic Resonance Imaging* ; Muscles ; Thrombin ; Thrombosis ; Venous Thrombosis*

Protein-calorie malnutrition is common in CAPD patients and is associated with increase in morbidity and mortality in CAPD patients. There are many causes of malnutrition in CAPD patients, and it is well known that a large amount of protein losses through peritoneal membrane is one of them. To investigate the effect of the peritoneal membrane transport characteristics on the nutritional status in long-term CAPD patients, we conducted a cross- sectional study on clinically stable 115 patients (63 males and 52 females) who have been on CAPD for more than 2 years, and assessed nutritional status by subjective global assessment (SGA), biochemical, anthropometric and urea kinetic parameters. Patients were divided into 4 groups according to the results of standard peritoneal equilibration test (PET). The results were as follows: 1) The patients were divided into 4 groups according to the PET results: high transporter (n=16, 14%), high average transporter (n=38, 33%), low average transporter (n=50, 43%), and low transporter (n=11, 10%). 2) The mean age of the patients was 50.1+/-11.6 years (range, 19-75) with sex ratio (M:F) 1.2:1 and mean duration of dialysis was 57.5+/-27.8 months (range, 24-135). The mean body weight (Bwt) was 59.2+/-8.9kg, percent ideal body weight (%IBW) was 104.7+/-15.6%, %lean body mass (LBM)/Bwt was 82.1+/-11.1%, and malnourished patients by subjective global assessment (SGA) were 32.2% (38/115). 3) The mean BUN, creatinine, total protein, and albumin level of the patients were 54.5+/-13.1mg/dL, 12.3+/-3.0mg/dL, 6.7+/-0.8g/dL, and 3.8+/-0.6g/dL, respectively. 4) There were no significant differences in age, sex ratio, CAPD duration, peritonitis rate, %LBM/ Bwt, and SGA among the 4 groups. 5) Total protein (g/dL) and albumin (g/dL) levels in high transporters were 6.4+/-0.5, 3.5+/-0.4, respectively, and they were significantly lower than those of low transporters (7.2+/-0.6, 4.2+/-0.5) (P<0.05). 6) 24 hour dialysate protein (g/day) and albumin (g/day) losses were significantly higher in high transporters (8.10+/-1.85, 4.19+/-1.23) compared to those of low transporters (5.07+/-1.85, 2.78+/-0.99) (P<0.05). 7) The level of IGF-1 (ng/mL) was significantly lower in high transporters (150.5+/-86.2) compared to that of low transporters (310.3+/-162.1) (P<0.05). 8) The level of BUN (mg/dL), Cr (mg/dL) were also lower in high transporters (45.4+/-13.1, 10.1+/-2.0) than those of low transporters (61.6+/-18, 14.7+/-2.7), but there were no significant differences in Hct, total cholesterol, prealbumin, and transferrin among the 4 groups. 9) There were no statistically significant differences in Kt/Vurea, RRF, NPCR, dietary calorie and protein intakes among the 4 groups. 10) Anthrometric parameters such as TSF, BSF, MAC and LBM measured by three different methods (LBMCr, LBMimp, LBManthro) didn't show any significant differences among the 4 groups. In conclusion, increased peritoneal permeability may not adversely affect SGA and anthropometric status of long-term CAPD patients, although it is associated with lower serum albumin, creatinine, and IGF-1 level. Clinical significance of these findings remains to be elucidated.
Body Weight ; Cholesterol ; Creatinine ; Dialysis ; Humans ; Ideal Body Weight ; Insulin-Like Growth Factor I ; Male ; Malnutrition ; Membranes ; Mortality ; Nutritional Status* ; Peritoneal Dialysis, Continuous Ambulatory* ; Peritonitis ; Permeability ; Prealbumin ; Protein-Energy Malnutrition ; Serum Albumin ; Sex Ratio ; Transferrin ; Urea

BACKGROUND: The automated border detection(ABD) echocardiography has the ability of recognizing the endocardial-blood interface, and therefore, on-line estimation of the left ventricular(LV) volume every cardiac cycle. Compared with the off-line conventional 2-dimensional echocardiographic method that requires tracing the endocardial border manually, the ABDd system can be a convenient and objective method in the estimation of the LV volume and the ejection fraction(EF). The purpose of this study is to compare the LV volume and EF between the on-line ABD system and the convertional off-line echocardiographic method. METHODS: In two weeks, 83 adult patients older than 16 years of age were referred to our echocardiographic laboratory. Among these 83 patients, 64 patients who had a normal sinus rhythm were included to our study. Using the Hewlett-Packard SONOS 1500, a 2.5 MHz transducer was placed dat the cardiac apex. Patients with an apical 4 chamber view of the LV in which at least 75% of the endocardium was clearly seen were selected for study. On that view, the ABD system was turned on, and the reansmit power and the time-gain compensation controls were adjusted in order to approximate the automated border to the visually apparent endocardial surface. The LV end-diastolic volume(LVESV) and LV end-systolic volume(LVESV) were calculated by the method of disc. LVEDV, LVESV, and EF were displayed every cardiac cycle. Also the off-line estimation of the LV volume was performed by the method of disc, after manually tracing the endocardial border on the apical 4 chamber view. RESULTS: 44 patients(69%) of 64 patients had > or =75% of the LV endocardium visualized. LVEDV, LVESV, and Ef with the ABD system were highly correlated with those with the off-line, manually traced method(r=0.95, 0.8, respectively), but LVEDV and EF with toe ABD system were significantly less than those with the latter(p<0.01). The limits of agreement between tow methods(off-line, manually traced method-ABD system) were somewhat wide. Those of LVEDV, LVESV and EF were +22~-10ml(mean 6ml), +15~-14ml(mean 0.1ml), and +19~-12%(mean 3.8%), respectively. CONCLUSION: LVEDV,LVESV, and EF measurements by the ABD system and the off-line manually traced methods thve a strong correlation, The ABD system should habe clinical applications in setting, in which measurements of LV volume and Ef are important, But, the comparison with a more reliable method is necessary.
Adult ; Compensation and Redress ; Echocardiography* ; Endocardium ; Humans ; Toes ; Transducers

Pyogenic liver abscess with metastatic septic complications is a rare and serious infectious disease if not treated properly. Pyogenic liver abscesses are caused by bacterial, fungal, or parasitic organisms. Escherichia coli used to be the predominant causative agent, but Klebsiella pneumoniae emerged as a major cause in the 1990s. Liver abscesses are caused by hepatic invasion via many routes, such as, the biliary tree, portal vein, hepatic artery, direct extension, or penetrating trauma. Furthermore, diabetes mellitus and malignant conditions are established important risk factors of K. pneumoniae liver abscesses and of septic metastasis, and several recent studies have asserted that K. pneumoniae liver abscess might be a presentation of occult or silent colon cancer. We report a case of K. pneumoniae liver abscess, metastatic septic pulmonary embolism, and endophthalmitis associated with diabetes and advanced gastric cancer.
Biliary Tract ; Colonic Neoplasms ; Communicable Diseases ; Diabetes Mellitus ; Endophthalmitis ; Escherichia coli ; Hepatic Artery ; Klebsiella pneumoniae ; Liver Abscess* ; Liver Abscess, Pyogenic ; Neoplasm Metastasis ; Pneumonia ; Portal Vein ; Pulmonary Embolism ; Risk Factors ; Stomach Neoplasms*

PURPOSE: To find the risk factors associated with coronory artery lesions, non-responsiveness to intravenous immunoglobulin(IVIG) treatment, and recurrences in Kawasaki disease patients. METHODS: We retrospectively analyzed 1,000 Kawasaki disease patients who were admitted to Yonsei University Medical Center from September 1990 to December 2003. We compared between responder and non-responder groups to IVIG treatment as well as between relapsed and non-relapsed groups, and as to the relapsed group, we also compared variables between patients in their first and second attack states. Finally, factors associated with longer-fever duration from disease onset were evaluated. RESULTS: Longer fever durations before and after IVIG treatment, male sex, lower Hgb and Hct level, higher WBC count and segmented WBC proportion, and higher CRP and Harada's score were related with coronary artery lesions. Non-responsiveness was related to higher WBC count, segmented WBC proportion, CRP, SGPT, Harada's score, and pyuria. Moderate-to-severe coronary artery dilatations and recurrences were more commonly seen among the non-responder group. No significant predictive factors for recurrence were found. In the relapsed group, lower WBC count, CRP, and shorter fever duration from disease onset were observed in their second attack state. Fever duration from disease onset showed positive correlation with WBC count, CRP, and Harada's score and negative correlation with Hgb levels. CONCLUSION: Higher WBC count, CRP, and higher Harada's score were related to both higher incidences of coronary artery lesions and non-responsiveness to IVIG treatment, and these factors were also related with longer fever duration. Non-responders to IVIG treatment showed higher recurrence rate and more moderate-to-severe coronary artery dilatations than responders.
Academic Medical Centers ; Alanine Transaminase ; Arteries ; Coronary Vessels ; Dilatation ; Fever ; Humans ; Immunoglobulins, Intravenous ; Incidence ; Male ; Mucocutaneous Lymph Node Syndrome* ; Pyuria ; Recurrence ; Retrospective Studies ; Risk Factors ; Treatment Failure ; Treatment Outcome

BACKGROUNDS/AIMS: In the treatment of complicated cholecystitis, laparoscopic cholecystectomy (LC) has limited efficacy due to its substantial post-operative complications. In addition, the clinical characteristics of complicated cholecystitis (CC) patients were suspected as advanced age with highly risky comorbidity. Percutaneous transhepatic gall bladder (PTGBD) drainage could be an alternative option for successful LC. Hence, this study evaluated the outcome of PTGBD for CC within and after 5 days. METHODS: The medical records of 109 consecutive CC patients who had undergone an LC between January 2007 and December 2011 were retrospectively reviewed and compared with the medical records of CC patients who had undergone an LC within 72 hours of (group I, n=63) or 5 days after PTGBD (group II, n=40). In addition, group I was divided into group Ia (n=46) and group Ib (n=17), according to the patients' development of open-conversion or post-operative complications. The clinical outcomes of the four groups were analyzed. RESULTS: There was a significantly higher reference to age, the ASA score grading, and predominant comorbidities in group II than in group I. The peri-operative results of group II showed lower blood loss and relatively shorter operating times than those of group I. In the cases of early LC within 72 hours (group Ia vs. group Ib), the difference was statistically insignificant. CONCLUSIONS: The delayed LC after PTGBD for complicated cholecystitis with high clinical risk had better results in this study, although it prolonged the patient's hospital stay.
Cholecystectomy, Laparoscopic ; Cholecystitis ; Cholecystitis, Acute ; Comorbidity ; Drainage ; Gallbladder ; Humans ; Length of Stay ; Medical Records ; Retrospective Studies ; Urinary Bladder

We experienced a case of Ebstein's anomaly prenatally by fetal sonography. Ebstein's anomaly is a rare congenital heart defect characterized by abnormally downward displacement of the septal and posterior leaflets of the tricuspid valve. In the absence of tricuspid regurgitation, this condition may be completely asymptomatic. On the other hand, symptomatic newborns often develop life-threatening congestive heart failure. A 30-year-old multiparous woman was referred for the evaluation of fetal cardiac defect at 26th gestational week from a private clinic. Fetal ultrasonography showed markedly enlarged right atrium and downward displacement of tricuspid valve into the right ventricle. After discussion with the patient, the pregnancy was terminated and Ebstein's anomaly was confirmed by autopsy.
Adult ; Autopsy ; Ebstein Anomaly* ; Female ; Hand ; Heart Atria ; Heart Defects, Congenital ; Heart Failure ; Heart Ventricles ; Humans ; Infant, Newborn ; Pregnancy ; Tricuspid Valve ; Tricuspid Valve Insufficiency ; Ultrasonography, Prenatal

PURPOSE: To assess the characteristic features of MR findings which would be useful for the differentiation of various spinal diseases involving paraspinal soft tissue mass. MATERIALS AND METHODS: We retrospectively reviewed MR findings in 31 cases(M:F=20:11) of spinal disease in which paraspinal mass was involved. The breakdown of cases was as follows : spinal tuberculosis, 12; spinal metastasis, 13; multiple myeloma, 3; pyogenic spondylitis, 2; spinal aspergillosis; 1. RESULTS: The pattern of bone marrow invasion in spinal metastasis, multiple myeloma, spinal tuberculosis and aspergillosis was mixed ; focal, homogeneously diffuse and inhomogeneously patterns were seen. Pyogenic spondylitis showed inhomogeneously diffuse invasion; an intravertebral abscess was seen in the only five cases of spinal tuberculosis. Vertebral posterior compartment invasion was observed in seven cases of spinal tuberculosis, two of multiple myeloma, the one case of spinal aspergillosis and in all 13 cases of spinal metastasis. This and multiple myeloma showed no disc space invasion, in any case, but all cases of infectious spondylitis showed such invasion. Peripheral rim-enhancement in the paravertebral mass was seen in 11 cases of spinal tuberculosis, one case of pyogenic spondylitis and the case of aspergillosis. Bilobate anterior epidural mass was noted in 60% of spinal tuberculosis cases, 36% of spinal metastasis and one case of pyogenic spondylitis. CONCLUSION: MR findings of spinal disease involving a paraspinal soft tissue mass were useful for differentiation.
Abscess ; Aspergillosis ; Bone Marrow ; Diagnosis, Differential* ; Magnetic Resonance Imaging* ; Multiple Myeloma ; Neoplasm Metastasis ; Retrospective Studies ; Spinal Diseases ; Spondylitis ; Tuberculosis ; Tuberculosis, Spinal

PURPOSE: Advances in the treatment of congenital heart disease and a decline in the incidence of rheumatic fever has led to changes in the causative organisms and the clinical outcome of infective endocarditis(IE). We sought to analyze the clinical outcome, prognostic factors, causative organisms and corresponding antibiotic sensitivity in IE. METHODS: Retrospective analysis of medical records of 104 children diagnosed and treated with IE at Severance Hospital, Yonsei University College of Medicine from January 1986 to June 2003 was undertaken. According to the Duke criteria, 55 patients were classified into the definite group(DG) and possible group(PG). RESULTS: Thirty one cases(56.4%) fulfilled the criteria for the definite group in the Duke criteria, whereas 24 cases(43.6%) fulfilled the criteria for the possible group. The most common chief complaint on admission was fever(93%). The most common infecting organism was Staphylococcus aureus, which was found in 14 cases(48.3%). Three cases(21.4%) of this organism were methicillin- resistant S. aureus(MRSA). Other causative organisms were alpha-streptococcus(seven cases, 24.1%), Staphylococcus epidermidis(three cases, 10.3%), Citrobacter freundii(one case, 3.8%), Enterococcus faecium(one case, 3.4%) and Candida albicans(three cases, 10.3%). Penicillin-resistant organisms were found in 90.5%(19/21) of total cases and the most sensitive antibiotics were vancomycin(13/13, 100 %) and teicoplanin(12/12, 100%). One case of IE due to MRSA unresponsive to vancomycin was treated with Arbekacin. CONCLUSION: The incidence of IE caused by S. aureus, especially MRSA, is increasing. Multi-drug resistant organisms are also emerging as a frequent cause of IE. Thus, in patients strongly suspected of having IE in patients with underlying heart disease, glycopeptides such as vancomycin combined with aminoglycosides should be considered, and if fever and positive blood cultures continue despite treatment with glycopeptides, a consideration of the use of new antibiotics may improve the treatment results.
Aminoglycosides ; Anti-Bacterial Agents ; Candida ; Child ; Citrobacter ; Endocarditis* ; Enterococcus ; Fever ; Glycopeptides ; Heart Defects, Congenital ; Heart Diseases ; Humans ; Incidence ; Medical Records ; Methicillin-Resistant Staphylococcus aureus ; Retrospective Studies ; Rheumatic Fever ; Staphylococcus ; Staphylococcus aureus ; Vancomycin