Loss of heterozygosity (LOH) has been established as an important genetic mechanism giving rise to malignant neoplasia. The mechanism of LOH has been shown to cause basal cell carcinoma and malignant melanoma as well as other types of skin cancer. A few studies on LOH in sporadic keratoacanthomas have been reported. The purpose of this study was to investigate the significance of LOH in the pathogenesis of sporadic keratoacanthomas developed in 10 Korean patients. The presents of LOH at 7 microsatellite markers (D2S286, D3S1317, D5S346, D9S160, D9S171, D10S185, and D17S261) were evaluated in sporadic keratoacanthomas. LOH was found in only 1 of 10 cases at D10S185. The low frequency of LOH detected in this study suggests that LOH may not be significant in the induction of sporadic keratoacanthomas.
Adult ; Aged ; Female ; Humans ; Keratoacanthoma/*genetics ; *Loss of Heterozygosity ; Male ; Middle Aged ; Research Support, Non-U.S. Gov't

Missing data such as appropriateness ratings in clinical research are a common problem and this often yields a biased result. This paper aims to introduce the multiple imputation method to handle missing data in clinical research and to suggest that the multiple imputation technique can give more accurate estimates than those of a complete-case analysis. The idea of multiple imputation is that each missing value is replaced with more than one plausible value. The appropriateness method was developed as a pragmatic solution to problem of trying to assess "appropriate" surgical and medical procedures for patients. Cataract surgery was selected as one of four procedures that were evaluated as a part of the Clinical Appropriateness Initiative. We created mild to high missing rates of 10%, 30% and 50% and compared the performance of logistic regression in cataract surgery. We treated the coefficients in the original data as true parameters and compared them with the other results. In the mild missing rate (10%), the deviation from the true coefficients was quite small and ignorable. After removing the missing data, the complete-case analysis did not reveal any serious bias. However, as the missing rate increased, the bias was not ignorable and it distorted the result. This simulation study suggests that a multiple imputation technique can give more accurate estimates than those of a complete-case analysis, especially for moderate to high missing rates (30 - 50%). In addition, the multiple imputation technique yields better accuracy than a single imputation technique. Therefore, multiple imputation is useful and efficient for a situation in clinical research where there is large amounts of missing data.
Cataract Extraction/*methods ; Humans ; Logistic Models ; Research Support, Non-U.S. Gov't

No abstract available.
Animals ; Humans ; *Organ Transplantation ; Research Support, Non-U.S. Gov't ; T-Lymphocytes/*immunology ; *Transplantation Immunology

This study examined ways of promoting research in the medical sciences by evaluating trends in research funding, and the present status of research funding by the Korea Science and Engineering Foundation (KOSEF). This study analyzed statistics from KOSEF from 1978 to 2003 to examine support for research. In medical science field, group-based programs receive more funding than do individual-based programs. The proportion of research funds allocated to the medical sciences has increased markedly each year. Researchers in the medical sciences have submitted more articles to Science Citation Index (SCI) journals than to non-SCI journals, relative to other fields. Researchers supported by the Mission-Oriented Basic Grants program have published the majority of these papers, followed by those supported by the Programs for Leading Scientists, Regional Scientists, Leading Women Scientists, Young Scientists, and Promising Women Scientists, in that order. Funding by KOSEF reflects many decades of government support for research and development, the development and maintenance of necessary infrastructure, and the education and training of medical scientists.
Biomedical Research/*economics ; Foundations/*economics/statistics & numerical data ; Humans ; Korea ; Research Support/*economics/trends ; Research Support, Non-U.S. Gov't ; Science

The aim of this study was to assess the involvement of multipotential progenitor cells in the pathogenesis of Mooren's ulcer using immunohistochemical staining techniques. Tissue specimens were collected from 3 Mooren's ulcer patients who underwent lamellar keratectomy. Immunohistochemical staining patterns were analyzed using antibodies: CD34, c-kit, STRO-1, CD45RO, VEGF and alpha-SMA. Strong positive CD34, c-kit and STRO-1 cells were revealed in Mooren's ulcer specimens, especially in the superficial stroma. A few weakly expressed CD34 stroma cells were seen in normal limbal cornea but no immunoreactivity for c-kit and STRO-1 could be found. CD45RO positive T cells were found to have infiltrated in Mooren's ulcer. The immunostaining pattern of VEGF and yen a- SMA was closely correlated with the degree of expression and the number of CD34 positive cells. Bone marrow-derived multipotential progenitor cells may be involved in the pathogenesis of Mooren's ulcer by synergizing with other factors to amplify autoimmune destructive reactions and to contribute to the regeneration process. Specific therapeutic strategies that target the role of these cells in the disease are warranted.
Cornea/*pathology ; Corneal Ulcer/*pathology ; Hematopoietic Stem Cells/*pathology ; Humans ; Multipotent Stem Cells/*pathology ; Research Support, Non-U.S. Gov't

One of the main reasons for the soaring interest in acute ischemic stroke among radiologists is the advent of new magnetic resonance techniques such as diffusion-weighted imaging. This new modality has prompted us to seek a better understanding of the pathophysiologic mechanisms of cerebral ischemia/infarction. The ischemic penumbra is an important concept and tissue region because this is the target of various recanalization treatments during the acute phase of stroke. In this context, it is high time for a thorough review of the concept, especially from the imaging point of view.
Brain/radiography ; Cerebrovascular Accident/*diagnosis ; Humans ; Magnetic Resonance Imaging ; Research Support, Non-U.S. Gov't ; Tomography, X-Ray Computed

It is not yet clear whether Glutathione S-transferase M1 (GSTM1) polymorphisms affect the risk of breast cancer. The aim of this study is to provide a comprehensive meta-analysis of all the available, published case-control studies on the extent of the possible association between GSTM1 polymorphisms and susceptibility to breast cancer. Twenty case-control studies on GSTM1 and breast cancer were identified using both PUBMED and a manual search. Meta-analysis was conducted by the Peto method. Subgroup analyses were undertaken, in order to explore the relationship between effect sizes and the study characteristics. The overall odds ratio (OR) was found to be 1.06 (95% CI, 0.99-1.14). The OR for post-menopausal women with GSTM1 deficiency was determined to be 1.19 (95% CI, 1.05-1.34). In populations with a low frequency of GSTM1 deficiency, a greater increase was observed (OR, 1.20; 95% CI, 1.08-1.34). Furthermore, the highest associations were found in post-menopausal women with a low frequency of GSTM1 deficiency (OR, 1.44; 95% CI, 1.20-1.73). The fact that GSTM1 deficiency is not rare in the general population implies that the attributable risk for breast cancer could be sizable. Further studies focusing on the structure of haplotype blocks of GSTM1 are required in order to find a specific haplotype with a predisposing breast cancer susceptibility allele.
Breast Neoplasms/*epidemiology/*genetics ; Female ; Glutathione Transferase/*genetics ; Humans ; *Polymorphism, Genetic ; Research Support, Non-U.S. Gov't ; Risk Factors

Each diastereomer of 10-thiophenyl- and 10-benzenesulfonyl-dihydroartemisinin was synthesized from artemisinin in three steps, and screened against chloroquine-resistance and chloroquine-sensitive Plasmodium falciparum. Three of the four tested compounds were found to be effective. Especially, 10 beta-benzenesulfonyl-dihydroartemisinin showed stronger antimalarial activity than artemisinin.
Animals ; Antimalarials/chemistry/*pharmacology ; Artemisinins/chemistry/*pharmacology ; Chloroquine/pharmacology ; Drug Resistance ; Plasmodium falciparum/*drug effects ; Research Support, Non-U.S. Gov't

Proteomics is one of the most important issues in the post-genomic area, because it can greatly contribute to identifying protein biomarkers for disease diagnosis and drug screening. Protein array is a key technology for proteome researches and has been analyzed by various methods including fluorescence, mass spectrometry, atomic force microscopy and surface plasmon resonance (SPR). SPR biosensor is a promising technology in proteomics, since it has various advantages including real-time measurement of biomolecular interactions without labeling and the simple optical system for the device. SPR biosensors have a strong potential for analyzing proteomes by SPR imaging and SPR spectroscopic imaging, even though the challenge is to produce proteins on a proteomic scale.
Animals ; *Biosensing Techniques ; Humans ; Protein Array Analysis ; *Proteomics ; Research Support, Non-U.S. Gov't ; *Surface Plasmon Resonance/instrumentation/methods

Developmental surface ultrastructure of Macroorchis spinulosus was studied by scanning electron microscopy. One-day-old juvenile fluke was leaf-shaped and bent ventrally. Body surface was covered densely with peg-like spines and with cobblestone-like cytoplasmic processes. Ciliated sensory papillae were concentrated around oral sucker. Several unciliated sensory papillae occurred equidistantly on oral sucker and acetabulum. The ciliated papillae appeared in two longitudinal lines symmetric bilaterally on dorsal surface. On adult flukes, tegumantal spines became wider in middle of the body surface. The cytoplasmic processes differentiated into more fine velvety form. It is likely that the differentiated fine cytoplasmic processes are an increased absorptive surface to adult M. spinulosus. It is suggested that single pointed tegumental spines on anterior half of the body may be supportive for this fluke to migration.
Animals ; Microscopy, Electron, Scanning ; Rats ; Rats, Sprague-Dawley ; Research Support, Non-U.S. Gov't ; Trematoda/*anatomy & histology/*ultrastructure