• 제목/요약/키워드: Threshold regression

검색결과 246건 처리시간 0.02초

유럽인 자료로 산출된 조현병 다유전자 위험도 점수의 한국인 조현병 환자를 대상으로 한 적용 (Comparison of Polygenic Risk for Schizophrenia between European and Korean Populations)

  • 이진영;이동빈;조은영;백지현;홍경수
    • 대한조현병학회지
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    • 제23권2호
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    • pp.65-70
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    • 2020
  • Objectives: This study aimed to explore whether common genetic variants that confer the risk of schizophrenia have similar effects between Korean and European ancestries using the polygenic risk score (PRS) analysis. Methods: Study subjects included 713 Korean patients with schizophrenia and 497 healthy controls. The Korea Biobank array was used for genotyping. Summary statistics of the most recent genome-wide association study (GWAS) of the European population were used as baseline data to calculate PRS. Logistic regression was conducted to determine the association between calculated PRS of European patients with schizophrenia and clinical diagnosis of schizophrenia in the Korean population. Results: Schizophrenia PRS was significantly higher in patients with schizophrenia than in healthy controls. The PRS at the p-value threshold of 0.5 best explained the variance of schizophrenia (R2=0.028, p=4.4×10-6). The association was significant after adjusting for age and sex (odds ratio=1.34, 95% confidence interval=1.19-1.51, p=1.1×10-6). The pattern of the association remained similar across different p-value thresholds (0.01-1). Conclusion: Schizophrenia PRS calculated using the European GWAS data showed a significant association with the clinical diagnosis of schizophrenia in the Korean population. Results suggest overlapping genetic risk variants between the two populations.

Effect of prehydration solution on hearing threshold after chemotherapy in patients with head and neck cancers: a retrospective study

  • Dongbin Ahn;Kyu-Yup Lee;Eunjung Oh;Minji Oh;Boseung Jung;Da Jung Jung
    • Journal of Yeungnam Medical Science
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    • 제40권2호
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    • pp.164-171
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    • 2023
  • Background: The study aimed to evaluate the effect of prehydration solution on hearing thresholds after cisplatin chemotherapy. Methods: In this retrospective cohort study, we reviewed the data of patients who underwent ≥3 courses of cisplatin-based chemotherapy for locally advanced head and neck cancers at a tertiary referral center (n=64). The dextrose solution (DW) group (n=26) received 2 L of normal saline and 1 L of 5% dextrose. The Hartmann solution (HS) group (n=38) received 2 L of normal saline and 1 L of HS. Hearing data were measured 1 day before starting the first course of chemotherapy, and again 20 days after the first, second, and third courses of chemotherapy. The severity of hearing loss was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE). Results: Thresholds at all frequencies after chemotherapy were greater in the DW group than in the HS group. The increase in thresholds in 1 to 4 kHz after the third course of chemotherapy was greater in the DW group than in the HS group. CTCAE grades after the second and third courses of chemotherapy were greater in the DW group than in the HS group. Logistic regression showed that the odds ratio for CTCAE grade 3 or 4 after the third course of chemotherapy in the DW group was 4.84 on univariate analysis. Conclusion: Prehydration using a solution with salt was associated with a decrease in change in hearing thresholds after cisplatin chemotherapy in patients with head and neck cancers.

Pathologic conditions associated with impacted third molars: A retrospective study of panoramic radiographs in a Southern Brazilian population

  • Gabriela Brum Cardoso;Gleica Dal' Ongaro Savegnago;Waneza Dias Borges Hirsch;Mariana Boessio Vizzotto;Gabriela Salatino Liedke
    • Imaging Science in Dentistry
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    • 제53권4호
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    • pp.303-312
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    • 2023
  • Purpose: This study investigated the prevalence of developmental and acquired pathologic conditions associated with impacted third molars (3Ms) in a Southern Brazilian population and evaluated whether demographic and tooth characteristics were correlated with the presence of bone or tooth lesions. Materials and Methods: Panoramic radiographs were assessed for developmental (bone-related) or acquired (tooth-related) pathoses associated with impacted upper or lower 3Ms. Data on tooth positioning, tooth development, and patient demographics were collected. A trained, calibrated postgraduate student evaluated all images. Binary and multivariate logistic regression models were used to assess associations between outcomes and the demographic and radiographic variables. The threshold for statistical significance was set at 5% (P<0.05). Results: The sample comprised panoramic radiographs from 2054 patients, predominantly female (59.2%), with a mean age of 27.2±11.5 years. Overall, 4066 impacted 3Ms were evaluated, revealing 471 (11.6%) developmental and 710 (17.5%) acquired pathoses. Among the developmental pathoses, 460 (95.2%) were indicative of dentigerous cysts. Male sex, lower 3M location, vertical or distoangular positioning, and incomplete root formation were associated with an elevated likelihood of developmental pathology. Lower tooth position, complete root formation, and partial eruption were linked to an increased probability of an acquired pathology in the third or second molar. Conclusion: The prevalence of pathologic conditions associated with impacted 3Ms was low. Male sex, lower 3M placement, horizontal or distoangular positioning, and incomplete root formation were associated with developmental pathoses, while lower tooth position, complete root formation, and partial eruption were related to acquired pathoses.

기후변화 시나리오의 기온상승에 따른 낙동강 남세균 발생 예측을 위한 데이터 기반 모델 시뮬레이션 (Data-driven Model Prediction of Harmful Cyanobacterial Blooms in the Nakdong River in Response to Increased Temperatures Under Climate Change Scenarios)

  • 장가연;조민경;김자연;김상준;박힘찬;박준홍
    • 한국물환경학회지
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    • 제40권3호
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    • pp.121-129
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    • 2024
  • Harmful cyanobacterial blooms (HCBs) are caused by the rapid proliferation of cyanobacteria and are believed to be exacerbated by climate change. However, the extent to which HCBs will be stimulated in the future due to increased temperature remains uncertain. This study aims to predict the future occurrence of cyanobacteria in the Nakdong River, which has the highest incidence of HCBs in South Korea, based on temperature rise scenarios. Representative Concentration Pathways (RCPs) were used as the basis for these scenarios. Data-driven model simulations were conducted, and out of the four machine learning techniques tested (multiple linear regression, support vector regressor, decision tree, and random forest), the random forest model was selected for its relatively high prediction accuracy. The random forest model was used to predict the occurrence of cyanobacteria. The results of boxplot and time-series analyses showed that under the worst-case scenario (RCP8.5 (2100)), where temperature increases significantly, cyanobacterial abundance across all study areas was greatly stimulated. The study also found that the frequencies of HCB occurrences exceeding certain thresholds (100,000 and 1,000,000 cells/mL) increased under both the best-case scenario (RCP2.6 (2050)) and worst-case scenario (RCP8.5 (2100)). These findings suggest that the frequency of HCB occurrences surpassing a certain threshold level can serve as a useful diagnostic indicator of vulnerability to temperature increases caused by climate change. Additionally, this study highlights that water bodies currently susceptible to HCBs are likely to become even more vulnerable with climate change compared to those that are currently less susceptible.

Simultaneous resection of synchronous colorectal liver metastasis: Feasibility and development of a prediction model

  • Mufaddal Kazi;Shraddha Patkar;Prerak Patel;Aditya Kunte;Ashwin Desouza;Avanish Saklani;Mahesh Goel
    • 한국간담췌외과학회지
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    • 제27권1호
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    • pp.40-48
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    • 2023
  • Backgrounds/Aims: Timing of resection for synchronous colorectal liver metastasis (CRLM) has been debated for decades. The aim of the present study was to assess the feasibility of simultaneous resection of CRLM in terms of major complications and develop a prediction model for safe resections. Methods: A retrospective single-center study of synchronous, resectable CRLM, operated between 2013 and 2021 was conducted. Upper limit of 95% confidence interval (CI) of major complications (≥ grade IIIA) was set at 40% as the safety threshold. Logistic regression was used to determine predictors of morbidity. Prediction model was internally validated by bootstrap estimates, Harrell's C-index, and correlation of predicted and observed estimates. Results: Ninety-two patients were operated. Of them, 41.3% had rectal cancers. Major hepatectomy (≥ 4 segments) was performed for 25 patients (27.2%). Major complications occurred in 20 patients (21.7%, 95% CI: 13.8%-31.5%). Predictors of complications were the presence of comorbidities and major hepatectomy (area under the ROC curve: 0.692). Unacceptable level of morbidity (≥ 40%) was encountered in patients with comorbidities who underwent major hepatectomy. Conclusions: Simultaneous bowel and CRLM resection appear to be safe. However, caution should be exercised when combining major liver resections with bowel resection in patients with comorbid conditions.

The Diagnostic Performance of the Length of Tumor Capsular Contact on MRI for Detecting Prostate Cancer Extraprostatic Extension: A Systematic Review and Meta-Analysis

  • Tae-Hyung Kim;Sungmin Woo;Sangwon Han;Chong Hyun Suh;Soleen Ghafoor;Hedvig Hricak;Hebert Alberto Vargas
    • Korean Journal of Radiology
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    • 제21권6호
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    • pp.684-694
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    • 2020
  • Objective: The purpose was to review the diagnostic performance of the length of tumor capsular contact (LCC) on magnetic resonance imaging (MRI) for detecting prostate cancer extraprostatic extension (EPE). Materials and Methods: PubMed and EMBASE databases were searched up to March 24, 2019. We included diagnostic accuracy studies that evaluated LCC on MRI for EPE detection using radical prostatectomy specimen histopathology as the reference standard. Quality of studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity and specificity were pooled and graphically presented using hierarchical summary receiver operating characteristic (HSROC) plots. Meta-regression and subgroup analyses were conducted to explore heterogeneity. Results: Thirteen articles with 2136 patients were included. Study quality was generally good. Summary sensitivity and specificity were 0.79 (95% confidence interval [CI] 0.73-0.83) and 0.67 (95% CI 0.60-0.74), respectively. Area under the HSROC was 0.81 (95% CI 0.77-0.84). Substantial heterogeneity was present among the included studies according to Cochran's Q-test (p < 0.01) and Higgins I2 (62% and 86% for sensitivity and specificity, respectively). In terms of heterogeneity, measurement method (curvilinear vs. linear), prevalence of Gleason score ≥ 7, MRI readers' experience, and endorectal coils were significant factors (p ≤ 0.01), whereas method to determine the LCC threshold, cutoff value, magnet strength, and publication year were not (p = 0.14-0.93). Diagnostic test accuracy estimates were comparable across all assessed MRI sequences. Conclusion: Greater LCC on MRI is associated with a higher probability of prostate cancer EPE. Due to heterogeneity among the studies, further investigation is needed to establish the optimal cutoff value for each clinical setting.

Prevalence and factors associated with postpartum depression among Bhutanese mothers: a cross-sectional study

  • Sherab Zangmo;Waraporn Boonchieng;Chalinee Suvanayos;Kelzang Gyeltshen;Pallop Siewchaisakul
    • 여성건강간호학회지
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    • 제30권3호
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    • pp.238-249
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    • 2024
  • Purpose: This study investigated the prevalence of postpartum depression (PPD) and explored associated factors among mothers attending postnatal care in Bhutan. Methods: A cross-sectional study was conducted from August to November 2023 at a national referral hospital in Thimphu, the capital city of Bhutan. In total, 314 mothers were recruited. Sociodemographic, psychosocial, obstetric, and infant-related data were collected using questionnaires. The Edinburgh Postnatal Depression Scale, with a threshold of ≥11, was employed to screen for PPD, and logistic regression was used to test the potential factors. Results: The prevalence of PPD was 14.97%. Mothers with a perceived change in body image (adjusted odds ratio [AOR], 4.40; 95% confidence interval [CI], 1.91-10.17; p=.001), perceived heightened stress after delivery (AOR, 3.74; 95% CI, 1.45-9.67; p=.006), poor relationship with inlaws (AOR, 2.57; 95% CI, 1.24-5.30; p=. 011), and negative birth experience (AOR, 2.42; 95% CI, 1.17-5.00; p=.016) demonstrated significantly higher odds of developing PPD. However, mothers with a higher monthly family income (Bhutanese ngultrum [Nu.] 20,000 to <50,000; AOR, 0.35; 95% CI, 0.13-0.92; p=.033), ≥Nu. 50,000 (AOR, 0.37; 95% CI, 0.13-1.07, p=.067) compared to <Nu. 20,000, and advanced gestational age (37 to <41 weeks; AOR, 0.25; 95% CI, 0.09-0.71; p=.009) and ≥41 weeks (AOR, 0.08; 95% CI, 0.00-0.75; p=.028) compared to <37 weeks had significantly lower risks of PPD. Conclusion: To mitigate the prevalence and risk of PPD, prioritizing screening strategies and interventions may benefit mothers with perceived changes in body image and heightened perceived stress after delivery, poor relationships with in-laws, and those with negative birth experiences.

높은 체감온도가 서울의 여름철 질병 사망자 증가에 미치는 영향, 1991-2000 (The Impact of High Apparent Temperature on the Increase of Summertime Disease-related Mortality in Seoul: 1991-2000)

  • 최광용;최종남;권호장
    • Journal of Preventive Medicine and Public Health
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    • 제38권3호
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    • pp.283-290
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    • 2005
  • Objectives : The aim of this paper was to examine the relationship between the summertime (June to August) heat index, which quantifies the bioclimatic apparent temperature in sultry weather, and the daily disease-related mortality in Seoul for the period from 1991 to 2000. Methods : The daily maximum (or minimum) summertime heat indices, which show synergetic apparent temperatures, were calculated from the six hourly temperatures and real time humidity data for Seoul from 1991 to 2000. The disease-related daily mortality was extracted with respect to types of disease, age and sex, etc. and compared with the time series of the daily heat indices. Results : The summertime mortality in 1994 exceeded the normal by 626 persons. Specifically, blood circulation-related and cancer-related mortalities increased in 1994 by 29.7% (224 persons) and 15.4% (107 persons), respectively, compared with those in 1993. Elderly persons, those above 65 years, were shown to be highly susceptible to strong heat waves, whereas the other age and sex-based groups showed no significant difference in mortality. In particular, a heat wave episode on the 22nd of July 2004 ($>45^{\circ}C$ daily heat index) resulted in double the normal number of mortalities after a lag time of 3 days. Specifically, blood circulation-related mortalities, such as cerebral infraction, were predominant causes. Overall, a critical mortality threshold was reached when the heat index exceeded approximately $37^{\circ}C$, which corresponds to human body temperature. A linear regression model based on the heat indices above $37^{\circ}C$, with a 3 day lag time, accounted for 63% of the abnormally increased mortality (${\geq}+2$ standard deviations). Conclusions : This study revealed that elderly persons, those over 65 years old, are more vulnerable to mortality due to abnormal heat waves in Seoul, Korea. When the daily maximum heat index exceeds approximately $37^{\circ}C$, blood circulation-related mortality significantly increases. A linear regression model, with respect to lag-time, showed that the heat index based on a human model is a more dependable indicator for the prediction of hot weather-related mortality than the ambient air temperature.

감각신경성 청력손실에 영향을 미치는 제 요인에 관한 연구 (Evaluation of factors affecting sensory neural hearing loss)

  • 홍성철;배성욱;이종영
    • Journal of Preventive Medicine and Public Health
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    • 제31권2호
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    • pp.249-264
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    • 1998
  • 감각신경성 난청은 성인에서 장애의 원인 중 큰 비중을 차지하고 있으며, 특히 소음성 난청은 흔한 직업병 중의 하나이며 산업보건사업의 주요 관심 중의 하나이다. 그러나 소음폭로와 노화를 제외하고는 대부분의 경우 그 원인이 규명되지 않고 있는 실정이다. 그러므로 난청에 대한 개인간의 감수성을 결정하는데 중요한 요인을 찾는 것은 중요하며 최근 청력손실의 측정치로서 소음 외 변수와의 상관성을 연구함으로써 청력손실에 대한 개인의 감수성의 차이를 밝히려는 많은 시도가 있었다. 특히 소음성 난청에 대한 많은 연구가 있어 왔지만 소음성 난청에 대한 감수성의 개인차에 대해서는 만족하게 설명하지 못하고 있다. 본 연구는 소음 비폭로자를 대상으로 소음폭로 이외 감각신경성 난청을 유발하는 잠재적 위험 인자들을 찾아내어 그 위험인자들의 역할을 평가하기 위해 주로 심혈관 위험인자와 지혈 및 혈액점도 요인이 청력손실에 미치는 영향에 대해 조사하였다. 대구시내 모 대학병원에서 91년에서 96년까지 종합검진을 받은 3050명을 대상으로 하여 청력검사와 혈액검사 및 생화학 검사 결과를 검진자료에 추출하여 위험인자들과 청력손실간의 관련성을 연구하였다. 그 결과 소음을 제외하고 감각신경성 청력손실에 미치는 영향으로 연령과 성별이 가장 크며, 성별 분포의 차이는 연구 변수에는 포함되지 않는 흡연력, 취미, 과거 소음폭로 등이 영향을 미친 것으로 보이며 본 연구에서는 확인할 수 없었다. 그리고 심혈관 위험인자인 체격지수, 혈압, 총콜레스테롤, 중성지방이 양의 영향을 알부민은 음의 영향을 어느 정도 미치는 것으로 보인다. 혈중점도 및 지혈인자와 관련하여 헤마토크릿, 백혈구, 혈소판 용적백분율, 적혈구침강속도가 어느 정도 양의 관련성이 있는 것으로 나타났다. 그리고 심혈관 위험인자와 혈액점도 및 지혈인자는 상호 관련성이 있으며, 이들과 소음노출 등이 서로 상호 작용하여 청력에 나쁜 영향을 미치는 것으로 보인다.

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돼지 염색체상의 IGF II 유전자 인접 부위에서 번식 및 성장형질에 연관된 Imprinting 양적형질 유전자 좌위(QTL)의 탐색 (Detection of Imprinted Quantitative Traits Loci (QTL) for Reproductive and Growth Traits in Region of IGF II Gene on fig Chromosome)

  • Lee, Hakkyo
    • 한국가축번식학회지
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    • 제25권4호
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    • pp.295-304
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    • 2001
  • 양적형질 유전자 좌위 (QTL)의 탐색과 이들의 발현 양상 규명을 위해 Berkshire종과 Yorkshire종 간의 교배를 통해 생산된 F$_2$ 실험집단에서 regression interval mapping이 이루어졌다. 모두 525마리의 F$_2$ 자손들에서 일당 증체량, 평균 등지방 두께, 배장근 단면적이 표현형으로 조사되어 분석에 이용되었으며 모돈의 번식능력에 관련된 QTL 존재 여부 추정을 위해 간접 형질로 인정되고 있는 생시체중과 이유 시 체중을 분석에 포함하였다. 양적형질의 분리 여부를 추론하기 위하여 돼지의 2번 염색체에서 8종의 microsatellite 표지인자가 선택되어 유전자형이 조사되었다. 각각의 유전적 모델에서 산출된 통계량으로부터 QTL 존재 여부와 특정 QTL 발현 양상에 대한 여부를 나타낼 수 있는 인정되는 수준의 type I 오차율을 제어할 수 있는 임계값 (threshold)을 permutation test에 의해 제시하였다. QTL의 존재와 그 QTL의 Imprinting 여부는 부계와 모계를 통해 원가계 1세대의 대립유전자가 전달되는 과정에서 발현되는 특성을 분리시키는 통계적 의형을 설정하여 검정 통계량을 산출하였다. 분석에 이용된 3가지 형질과 연관된 3종류의 QTL 존재 가능성을 돼지의 2번 염색체에서 확인하였으며, 이들 중 평균 등지방 두께와 배장근 단면적에 각각 영향을 미칠 것으로 추론된 2종류의 QTL 발현은 정상적인 Mendelian 유전양식을 따르지 않고 imprinting된다는 증거를 얻어냈다. 또한 이들 imprinting되는 QTL은 이미 imprinting 표현 양식을 가진다고 알려진 IGF II 유전자의 위치와 거의 동일한 염색체강의 지점에서 부계로 전달되는 QTL만이 발현되는 특징을 보이는 것으로 밝혀졌다. 한편 Mendelian 모형과 imprinting 모형 모두에서 유의적인 임계값 이상을 보이는 검정 통계량이 산출된 일당 증체량 연관 QTL은 두 모형간의 적정성 분석을 위한 검정을 퐁해 Mendelian 양식을 따른 것으로 최종 확인되었다.

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