Identifying Copy Number Variants under Selection in Geographically Structured Populations Based on F-statistics

Large-scale copy number variants (CNVs) in the human provide the raw material for delineating population differences, as natural selection may have affected at least some of the CNVs thus far discovered. Although the examination of relatively large numbers of specific ethnic groups has recently started in regard to inter-ethnic group differences in CNVs, identifying and understanding particular instances of natural selection have not been performed. The traditional FST measure, obtained from differences in allele frequencies between populations, has been used to identify CNVs loci subject to geographically varying selection. Here, we review advances and the application of multinomial-Dirichlet likelihood methods of inference for identifying genome regions that have been subject to natural selection with the FST estimates. The contents of presentation are not new; however, this review clarifies how the application of the methods to CNV data, which remains largely unexplored, is possible. A hierarchical Bayesian method, which is implemented via Markov Chain Monte Carlo, estimates locus-specific FST and can identify outlying CNVs loci with large values of FST. By applying this Bayesian method to the publicly available CNV data, we identified the CNV loci that show signals of natural selection, which may elucidate the genetic basis of human disease and diversity.

Identifying Copy Number Variants under Selection in Geographically Structured Populations Based on F-statistics

Large-scale copy number variants (CNVs) in the human provide the raw material for delineating population differences, as natural selection may have affected at least some of the CNVs thus far discovered. Although the examination of relatively large numbers of specific ethnic groups has recently started in regard to inter-ethnic group differences in CNVs, identifying and understanding particular instances of natural selection have not been performed. The traditional FST measure, obtained from differences in allele frequencies between populations, has been used to identify CNVs loci subject to geographically varying selection. Here, we review advances and the application of multinomial-Dirichlet likelihood methods of inference for identifying genome regions that have been subject to natural selection with the FST estimates. The contents of presentation are not new; however, this review clarifies how the application of the methods to CNV data, which remains largely unexplored, is possible. A hierarchical Bayesian method, which is implemented via Markov Chain Monte Carlo, estimates locus-specific FST and can identify outlying CNVs loci with large values of FST. By applying this Bayesian method to the publicly available CNV data, we identified the CNV loci that show signals of natural selection, which may elucidate the genetic basis of human disease and diversity.

Risk Factors for Falls among the Community-Dwelling Elderly in Korea / 간호학회지

Community-based centres were surveyed to determine the frequency of and risk factors for falls among elderly Koreans. We examined fall-related risk factors, including physiological and physical health, psychosocial functions, self-reported physical capacity and activity, vision, and the use of medication, among 351 elderly people aged 65 years or older, with ambulatory. Forty-two per cent of elderly Korean subjects reported at least one episode of falling in the previous 12 months, 38% of whom had consequences that required either the attention of a physician or hospitalization. Factors significantly associated with an increased risk of falling were a restricted activity during the previous five years (adjusted OR 1.3), use of alternative therapy (adjusted OR 2.7), low knee flexor and extensor-muscle strength (adjusted OR 1.21 and 1.20), and poor balance with closed eyes (adjusted OR 8.32). We conclude that falls among older persons living in the community are common in Korea and that indicator of bad health and frailty or variables directly related to neuromuscular impairment are significant predictors of the risk of falling.

Fall Prevention Exercise Program for Fall Risk Factor Reduction of the Community-Dwelling Elderly in Korea

A randomized comparison of pre-and post-experimental design was used to examine the effects of a fall prevention exercise program (FPEP) on muscle strength, ankle flexibility, balance, instrumental activities of daily living (IADLs), and depression for the community-dwelling elderly in Korea. Twenty-two subjects were assigned to an experimental group and twenty-three to a control group. The experimental group participated in a 4-day-per week FPEP of 8 weeks duration, twice a week by direct instruction and twice a week with videotaped instruction by the program instructor at each senior center. The eight-week FPEP turned out to be significantly effective in enhancing muscle strength, ankle flexibility and balance, and in reducing depression, after intervention among community-dwelling elderly in Korea. IADLs, however, was not changed by the intervention. Further research with a larger sample and longer follow up period is needed to expand our understanding about the effects of FPEP. Future study is also recommended to differentiate between the effects of FPEP by direct instruction and by videotaped.

A Meta-Analysis of Effects of Relaxation Therapy on Anxiety and Blood Pressure / 간호학회지

A meta-analysis of 14 quasi-experimental studies was conducted to compare the effect of size on various relaxation therapies applied to patients and health volunteer students. These studies were selected from theses, dissertations and papers that have been done between 1982 to 1993. Also They have a randomized or nonequivalent control group in a pre test-post test design. The studies were evaluated in different ways; 1) types of relaxation therapy, 2) total amount of time of relaxation therapy, and 3) types of outcome variables. For a group of homogenious studies, the weighted mean effect size and standard error were estimated. Some findings are summarized as follows : 1. Jacobson relaxation therapy had a larger effect on systolic and diastolic blood pressures than on state anxiety. 2. For the total time of relaxation therapy, (longer than 60 minutes) had a much larger effect in decreasing systolic and diastolic blood pressures than in the case of a time period shorter than 60 minutes. 3. Relaxation therapy applied to surgery patients also had a larger effect in decreasing state anxiety than when applied to other patients.

A Meta-Analysis of Effects of Relaxation Therapy on Anxiety and Blood Pressure / 간호학회지

A meta-analysis of 14 quasi-experimental studies was conducted to compare the effect of size on various relaxation therapies applied to patients and health volunteer students. These studies were selected from theses, dissertations and papers that have been done between 1982 to 1993. Also They have a randomized or nonequivalent control group in a pre test-post test design. The studies were evaluated in different ways; 1) types of relaxation therapy, 2) total amount of time of relaxation therapy, and 3) types of outcome variables. For a group of homogenious studies, the weighted mean effect size and standard error were estimated. Some findings are summarized as follows : 1. Jacobson relaxation therapy had a larger effect on systolic and diastolic blood pressures than on state anxiety. 2. For the total time of relaxation therapy, (longer than 60 minutes) had a much larger effect in decreasing systolic and diastolic blood pressures than in the case of a time period shorter than 60 minutes. 3. Relaxation therapy applied to surgery patients also had a larger effect in decreasing state anxiety than when applied to other patients.

Relationship between Occupational Electromagnetic Field Exposure and Leukemia: A Meta-Analysis / 예방의학회지

OBJECTIVES: This study uses meta-analysis methodology to examine the statistical consistency and importance of random variation among results of epidemiologic studies of occupational electromagnetic field exposure and leukemia. METHODS: Studies for this meta-analysis were identified from previous reviews and by asking researcher active in this field for recommendations. Overall, 27 studies of occupational electromagnetic field exposures and leukemia were reviewed. A variety of meta-analysis statistical methods have been used to assess combined effects, to identify heterogeneity, and to provide a single summary risk estimate based on a set of simiar epidemiologic studies. In this study, classification of exposure metircs on occupational epidemiologic studies are reported for (1) job classification (20 individual studies); (2) leukemia subtypes (13 individual studies); and (3) country (27 individual studies). RESULTS: Results of this study, an inverse-variance weighted pooling of all the data leads to a small but significant elevation in risk of 11% (OR=1.11, 95% CI : 1.06~1.16) among 27 occupational epidemiologic studies. Publication bias was assessed by the 'fail-safe n' that may be not influence for all combined results exception a few categories, ie, "power station operators" and "electric utility workers" by job classification on occupational study. And all combined odds ratio results were similar for fixed-effects models and random-effects models, with slightly higher risk estimates for the random-effects model in situations where there was significant heterogeneity, ie, Q-statistic significant (p<.05). CONCLUSIONS: We found a small elevation in risk of leukemia, but the ubiquitous nature of exposure to electromagnetic fields from workplace makes even a weak association a public health issue of substantial power to influence the present overall conclusion about relationship between electromagnetic fields exposure and leukemia.

Clinical Impact of Postoperative Tamoxifen Therapy in Patients with Breast Cancer

BACKGROUND: Tamoxifen is one of the most widely prescribed drug in patients with breast cancer and has been proven to have a favorable effect on disease-free survival (DFS) and overall survival (OS) when given as an adjuvant therapy. However, there is little known about the effects of tamoxifen in Korean patients with breast cancer. The purpose of this report was to obtain the informations about tamoxifen as an adjuvant therapy for the prospective study hereafter. METHODS: The medical records of 349 patients with breast cancer from Jan. 1 1988 to Dec. 31 1995, who have no distant metastasis and have had adjuvant therapies after surgery with appropriate follow up, were reviewed retrospectively. The univariate analysis of various prognostic factors, such as age, menopausal status, stage, steroid receptor status, operation method, chemotherapy, and the relationship of tamoxifen therapy with them were analyzed using SAS program. RESULTS: 1) The benefit of Tamoxifen administration in DFS was observed in women 40-49 and over 60 years of age, premenopausal women, tumors with the size of 2-5 cm, Stage IIb, progesterone receptor positive tumors, and for patients treated with chemotherapy and CAF (Cyclophopamide Adriamycin 5-Fluorouracil) regimen of it. Tamoxifen also improved OS in women over 60 years of age, Stage I or IIb, and for the patients treated with chemotherapy and CAF regimen (P<0.05, log rank or Wilcoxon test). 2) The relapse or death rate decreased linearly as the duration of tamoxifen administration was extended (P=0.001, Cochran-Armitage test). The Kaplan-Meier disease free and overall survival rates of the four groups of duration were significantly different (P=0.0001, logrank test). CONCLUSIONS: There is a benefit of tamoxifen therapy in the patients aged 60 or older, tumors with the size of 5 cm or less, Stage IIb or less, and for the patients treated with chemotherapy and CAF regimen of it. This benefit is increasing as the duration of tamoxifen administration is extended. Thebenefit of tamoxifen is unreliable in the patients aged 40-49, premenopausal women and progesterone receptor positive tumors, possibly because of bias in those subsets.

Effects of Nursing Interventions Applied to Surgery Patients: A Meta-analysis / 성인간호학회지

A meta-analysis of 13 quasi-experimental studies was conducted to determine the effect of various nursing interventions applied to surgery patients. The studies were selected from dissertations done between 1982 to 1996 and had randomized or nonequivalent control groups in a pretest-post test design. The studies were classified according to three criteria : 1) types of surgery 2) types of nursing interventions 3) types of respondent variables. The following analysis was done : 1) Determination of usefulness of nursing interventions for surgery patients. 2) The magnitude of effect for each study was tested for different types of surgery, nursing interventions and outcome variables. 3) For a group of homogenious studies, the weighted mean effect size and standard error were estimated. Some findings are summarized as follows : Nursing interventions on relaxation effect applied to surgery patients have resulted in a significant effect size on pain, anxiety, and BP stabilization. Relaxation and music therapy were more effective on surgery patients than either education, heat therapy, or purposeful touch. It was impossible to identify which type of surgery was more effected by these interventions. On the basis of these findings, the following recommendations were made : 1) Many studies on the same kind of intervention applied to similar surgery patients should be accumulated continuously to identify factors that affect the effect size. 2) The detailed explanation of research process, such as, assignment method to experimental and control groups, starting points, duration and frequency of nursing interventions, and estimation of the outcome variables should be described in orther to be utilized for further research and practice.

Impact of clinical history on film interpretation

We performed a study to determine whether clinical history gives a positive or negative influence on X-ray film interpretation. One hundred and nine patient's radiograms, consisting of 55 normal and 54 abnormal cases (136 abnormalities), were interpreted twice by three pairs of residents in radiology and a pair of qualified radiologists, without clinical history first and with clinical history next. The interpreters recorded diagnosis and confidence level of normal or abnormal findings on a six-point scale. Analysis of receiver operating characteristic (ROC) curves showed that knowledge of clinical history improved diagnostic accuracy. Residents, especially beginners, should be advised to obtain clinical history whenever they read radiograms.

Statistical Problems in the Determination of Normal Ranges from Laboratory Data / 예방의학회지

No abstract available.