The reported clinical results following revision of failed cemented hip arthroplasties have varied. The most improtaint aspect of revision surgery, especially in case of removal of well injected femoral cement need not be daunting if certain essential principles are understanding. The prohlem is hasically that of a tuhe (cement) fixed within another tube (femur). Otherwise, any attempt to work between the two will cause the instruments to skid off the cement and penetrate the femoral cortex. Therefore, on the first step to deal with the problem and theoretical ground, we have investigated the mode of fracture in bone cement. Prior to this study, a comparision of various cement strength been published by A.J.C. Lee, University of Exetcr, UK is rviewed for our reference. As far as cement crack is concerned, the re are three modes of fracture, namely, mode I, mode II and mode III. As seen in the Fig. 5, mode I fracture is defined to be the fracture under symmetic loading, which is perpendicular to the crack surface. Mode II fracture is the fracture under anti-symmetric loading, which is parallel to the crack surface. In mode III, the loading is perpendicular to both crack surface and the plan of the paper. On the left is the situation shown when using osteotome to crush the cement Fig. 6. The prohlem here is of dynamical nature, however, this kind of prohlem has not been solved yet. Prediction of the direction of propagation is possible by assuming the static nature when the osteotome just gets inside the cement. Small element with distance and angle from the osteotome tip under stress is also,shown on the left, Here, th mode of fracture is mode I. ∂θθ is obstained from fracture mechanics as this, and the direction of crack propagation is given by solving ∂θθ = o,i.e, the direction of maximum ∂θθwhich turns out to be 0=0. When chisel is used, the mode of fracture is th combined mode, i. e. Mode I + Mode II (Fig. 7). In an angiogous approach to the previous one, aθθis obtained, thus, the direction of propagation is given by solving ∂θθ/∂θ = 0. which results in θ=(−)α, the half of the included angle of the chisel, Note, however, that the direction of propagation given here is the initial direction of crack propagation. In practiee, the crack often gets curves, however, this phenomena is governed by other factors neglected in this presentation, such as inhomogenity, state of stress of bone, cement and stem, etc, Thus, quantitative study is required in addition to so've these phenomenon.
Arthroplasty ; Hip Prosthesis ; Hip ; Mechanics

The authors studied 5 cases of idiopathic CNS hypersomnia who visited Division of Sleep Studies, Seoul National University Hospital in 1995. Detailed medical history was taken and nocturnal polysomnography(NPSG), multiple sleep latency test(MSLT)and human leukocyte antigen(HLA) typing were performed. Neither cataplexy nor hypnagogic hallucination was reported in all cases and in NPSGs, there were tendencies of increased sleep period time and decreased slow wave sleep time. In MSLT, all the subjects showed average sleep latencies less than 8 minutes without sleep-onset rapid eye movement period(SOREMP). In HLA typing, some correlation between idiopathis CNS hypersomnia and HLA DR4 was observed. in contrast to previous reports, overall treatment response with methylphenidate was remarkable. Therefore, the authors suggest that patients suspected of idiopathic CNS hypersomnia be actively evaluated and treated with rather optimistic perspective.
Cataplexy ; Central Nervous System* ; Disorders of Excessive Somnolence* ; Hallucinations ; Histocompatibility Testing ; Humans ; Leukocytes ; Methylphenidate ; Seoul ; Sleep, REM

We have experienced two cases of Wernicke's encephalopathy associated with hypere-mesis gravidarum. Delay in it's diagnosis caused a protracted illness and persisting neurol-ogic deficits. Because of its association with chronic alcoholism, possibility of Wernicke's encephalopathy may not be considered in early stage of disease. The clinical feature, the principle of management and the prevention of Wernicke's encephalopathy are discussed.
Alcoholism ; Diagnosis ; Female ; Hyperemesis Gravidarum* ; Pregnancy ; Wernicke Encephalopathy*

No abstract available.
Allografts* ; Animals ; Blood Transfusion* ; Cyclosporine* ; Lymphocyte Culture Test, Mixed* ; Rats*

A flow cytometric analysis of the nuclear DNA content of solid tumors using paraffin-embedded tissues has become available since 1983, and its ploidy pattern has been designated as an important prognostic parameter in many human tumors. Hepatocellular carcinoma(HCC) is one of the most common malignant tumors among Koreans, but little information is consolidated about the significance of ploidy pattern. We measured the nuclear DNA content of 62 surgically resected HCCs and 45 non-neoplastic tissues from the surrounding parenchyma by flow cytometry. Aneuploid was detected in 18 cases(29.0%) in HCCs and 2 cases(4.4%) in nonneoplastic hepatic parenchyma(p<0.005). Correlations between the DNA ploidy pattern and various clinicopathologic findings of HCCs were analized. The mean tumor size was significantly different(p<0.05) between the aneuploid group(8.8 cm) and the diploid group(6.1 cm). Mean age of the aneuploid group was younger(47 year) than the diploid group(51 years), but the difference was not statistically significant(p=0.052). The DNA pattern did not show any meaningful correlation with the gross and microscopic features of HCC except for the presence of capsule. These results suggest that DNA ploidy correlates with growth rate of the tumor and it may be a possibly useful prognostic factor in HCCs.
Humans ; Carcinoma, Hepatocellular

No abstract available.
Bone Density* ; Child* ; Glucocorticoids* ; Humans ; Nephrotic Syndrome*

No abstract available.

Pacemaker-mediated tachycardia(PMT) is a circus movement tachycardia that can occur in patients with dual chamber pacemaker with atrial sensing(VDD or DDD), when a ventricular depolarization, either spontaneous or paced, causes retrograde activation of the atrium. Recently, a number of pacemaker manufactures have incorporated in their devices a variety of relatively complex algorithms to prevent PMT. Despite these measures, PMT may still occur because of inappropriate programming or unpredictable variations of ventriculoatrial conduction. We report one case of PMT in a 78-year-old male who received DDD type pacemaker due to sick sinus syndrome. In this case, PMT was disappeared after reprogramming parameters of pacemaker and the application of PMT protection algorithm.
Aged ; Dichlorodiphenyldichloroethane ; Humans ; Male ; Sick Sinus Syndrome ; Tachycardia*

To study reliability and validity of PWl, this newly developed self-administered questionnaire which measures stress, was given to medial students. All respondent(133) were followed 4 weeks later and 92 were retested. Cronbach's a coefficient of data was 0.93. Test-retest reliability measured by pearson's correlation coefficient was 0.72(p<0.01l). Exploratory factor analysis(EFA) performed by principal axis factor method without iteration and by varimax rotation explored 13 principal components(eigenvalues > l). After exploring 4 factor structure according to previous study results, factor 1 showed good agreement but other factors did not. Confirmatory factor analysis(CFA) showed poor fit of 4 factor model to data. In the further study, it may be considered to model that has unidimensional factor structure.
Axis, Cervical Vertebra ; Humans ; Surveys and Questionnaires ; Reproducibility of Results*

BACKGROUND: The purpose of this study is to compare clinical and radiological outcomes between trans-acromial fixation with Kirschner's wire (K-wire) and AO locking hook plate fixation for acute acromioclavicular (AC) joint dislocation. METHODS: This study included 61 patients who underwent either closed reduction and trans-acromial fixation with K-wire (group A, 23 patients) or open reduction and internal fixation with AO locking hook plate (group B, 38 patients). Pain on a visual analogue scale (VAS) score, the University of California Los Angeles (UCLA) shoulder score, the American Shoulder and Elbow Surgeons (ASES) score, and active range of motion (ROM) were used in the functional evaluation. For radiological evaluation, coracoclavicular distance (CCD) was measured on both clavicular anteroposterior view and compared between groups. RESULTS: At one-year follow-up, no significant differences in VAS pain score, UCLA shoulder score, ASES score, and active ROM were observed between groups, despite five cases (22.7%, 5/23) of complication in group A. The side-to-side difference between normal and affected CCD was 2.4 ± 2.2 mm in group A and 0.2 ± 0.7 mm in group B. This difference showed a statistical significance between groups (p<0.001). CONCLUSIONS: For the treatment of acute AC joint dislocation, the K-wire trans-acromial fixation group showed a significantly greater CCD than the AO locking hook plate group. In addition, during the follow-up period, much higher incidence of complication related to implant was observed in the trans-acromial fixation group. Although clinical outcomes between groups were not significantly different, these results should be interpreted carefully.
Acromioclavicular Joint* ; California ; Dislocations* ; Elbow ; Follow-Up Studies ; Humans ; Incidence ; Joints ; Range of Motion, Articular ; Shoulder ; Surgeons