205 research outputs found
Proteomic analysis of rhein-induced cyt: ER stress mediates cell death in breast cancer cells
Rhein is a natural product purified from herbal plants such as Rheum palmatum, which has been shown to have anti-angiogenesis and anti-tumor metastasis properties. However, the biological effects of rhein on the behavior of breast cancers are not completely elucidated. To evaluate whether rhein might be useful in the treatment of breast cancer and its cytotoxic mechanism, we analyzed the impact of rhein treatment on differential protein expression as well as redox regulation in a non-invasive breast cancer cell line, MCF-7, and an invasive breast cancer cell line, MDA-MB-231, using lysine- and cysteine-labeling two-dimensional difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF mass spectrometry. This proteomic study revealed that 73 proteins were significantly changed in protein expression; while 9 proteins were significantly altered in thiol reactivity in both MCF-7 and MDA-MB-231 cells. The results also demonstrated that rhein-induced cytotoxicity in breast cancer cells mostly involves dysregulation of cytoskeleton regulation, protein folding, the glycolysis pathway and transcription control. A further study also indicated that rhein promotes misfolding of cellular proteins as well as unbalancing of the cellular redox status leading to ER-stress. Our work shows that the current proteomic strategy offers a high-through-put platform to study the molecular mechanisms of rhein-induced cytotoxicity in breast cancer cells. The identified differentially expressed proteins might be further evaluated as potential targets in breast cancer therapy
Anemia risk in relation to lead exposure in lead-related manufacturing
Abstract Background Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb) levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. Methods We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD) modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI). We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Results Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50–1.26) with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67–77% and 86–95% by adopting the suggested BPb standards of 25 and 15 μg/dL. Conclusions We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention
Trypsin-induced proteome alteration during cell subculture in mammalian cells
<p>Abstract</p> <p>Background</p> <p>It is essential to subculture the cells once cultured cells reach confluence. For this, trypsin is frequently applied to dissociate adhesive cells from the substratum. However, due to the proteolytic activity of trypsin, cell surface proteins are often cleaved, which leads to dysregulation of the cell functions.</p> <p>Methods</p> <p>In this study, a triplicate 2D-DIGE strategy has been performed to monitor trypsin-induced proteome alterations. The differentially expressed spots were identified by MALDI-TOF MS and validated by immunoblotting.</p> <p>Results</p> <p>36 proteins are found to be differentially expressed in cells treated with trypsin, and proteins that are known to regulate cell metabolism, growth regulation, mitochondrial electron transportation and cell adhesion are down-regulated and proteins that regulate cell apoptosis are up-regulated after trypsin treatment. Further study shows that bcl-2 is down-regulated, p53 and p21 are both up-regulated after trypsinization.</p> <p>Conclusions</p> <p>In summary, this is the first report that uses the proteomic approach to thoroughly study trypsin-induced cell physiological changes and provides researchers in carrying out their experimental design.</p
Leptospira santorosai serovar shermani detergent extract induces an increase in fibronectin production through a toll-like receptor 2-mediated pathway
Leptospirosis can activate inflammatory responses through Toll-like receptors (TLRs) and may cause renal tubulointerstitial fibrosis characterized by the accumulation of extracellular matrix (ECM). We have previously demonstrated that Leptospira santorosai serovar Shermani detergent extract stimulates ECM accumulation in vitro. The aim of this study was to examine the mechanistic basis of these previous observations and, in particular, to examine the potential involvement of TLRs. The addition of serovar Shermani detergent extract led to an increase in fibronectin gene expression and production. Inhibition of TLR2 but not TLR4 expression abrogated serovar Shermani detergent extract-mediated increases in fibronectin production. This response was also blocked by the knockdown of the gene expression of the TLR2 downstream transducers myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6). Serovar Shermani detergent extract also activated nuclear factor-κB, and its inhibition by curcumin-attenuated serovar Shermani detergent extract induced increases in fibronectin production. These effects were also mimicked by the specific TLR2 agonist, Pam(3)CsK(4), a response that was also abrogated by the knockdown of MyD88 and TRAF6. Similarly, the administration of live leptospires to cells also induced fibronectin production that was blocked by inhibition of TLR2 and MyD88 expression. In conclusion, serovar Shermani detergent extract can induce fibronectin production through the TLR2-associated cascade, providing evidence of an association between TLRs and leptospirosis-mediated ECM deposition
Use and effectiveness of dapagliflozin in patients with type 2 diabetes mellitus: a multicenter retrospective study in Taiwan
Aims/Introduction To investigate the clinical outcomes of patients with type 2 diabetes mellitus (T2DM) who initiated dapagliflozin in real-world practice in Taiwan. Materials and Methods In this multicenter retrospective study, adult patients with T2DM who initiated dapagliflozin after May 1st 2016 either as add-on or switch therapy were included. Changes in clinical and laboratory parameters were evaluated at 3 and 6 months. Baseline factors associated with dapagliflozin response in glycated hemoglobin (HbA1c) were analyzed by univariate and multivariate logistic regression. Results A total of 1,960 patients were eligible. At 6 months, significant changes were observed: HbA1c by −0.73% (95% confidence interval [CI] −0.80, −0.67), body weight was -1.61 kg (95% CI −1.79, −1.42), and systolic/diastolic blood pressure by −3.6/−1.4 mmHg. Add-on dapagliflozin showed significantly greater HbA1c reduction (−0.82%) than switched therapy (−0.66%) (p = 0.002). The proportion of patients achieving HbA1c <7% target increased from 6% at baseline to 19% at Month 6. Almost 80% of patients experienced at least 1% reduction in HbA1c, and 65% of patients showed both weight loss and reduction in HbA1c. Around 37% of patients had at least 3% weight loss. Multivariate logistic regression analysis indicated patients with higher baseline HbA1c and those who initiated dapagliflozin as add-on therapy were associated with a greater reduction in HbA1c. Conclusions In this real-world study with the highest patient number of Chinese population to date, the use of dapagliflozin was associated with significant improvement in glycemic control, body weight, and blood pressure in patients with T2DM. Initiating dapagliflozin as add-on therapy showed better glycemic control than as switch therapy
Assessing trends and predictors of tuberculosis in Taiwan
<p>Abstract</p> <p>Background</p> <p>Variety of environmental and individual factors can cause tuberculosis (TB) incidence change. The purpose of this study was to assess the characteristics of TB trends in the period 2004 - 2008 in Taiwan by month, year, gender, age, temperature, seasonality, and aborigines.</p> <p>Methods</p> <p>The generalized regression models were used to examine the potential predictors for the monthly TB incidence in regional and national scales.</p> <p>Results</p> <p>We found that (<it>i</it>) in Taiwan the average TB incidence was 68 per 100,000 population with mortality rate of 0.036 person<sup>-1 </sup>yr<sup>-1</sup>, (<it>ii</it>) the highest TB incidence rate was found in eastern Taiwan (116 per 100,000 population) with the largest proportion of TB relapse cases (8.17%), (<it>iii</it>) seasonality, aborigines, gender, and age had a consistent and dominant role in constructing TB incidence patterns in Taiwan, and (<it>iv</it>) gender, time trend, and 2-month lag maximum temperature showed strong association with TB trends in aboriginal subpopulations.</p> <p>Conclusions</p> <p>The proposed Poisson regression model is capable of forecasting patterns of TB incidence at regional and national scales. This study suggested that assessment of TB trends in eastern Taiwan presents an important opportunity for understanding the time-series dynamics and control of TB infections, given that this is the typical host demography in regions where these infections remain major public health problems.</p
Anemia risk in relation to lead exposure in lead-related manufacturing
Abstract Background Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb) levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. Methods We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD) modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI). We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Results Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50–1.26) with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67–77% and 86–95% by adopting the suggested BPb standards of 25 and 15 μg/dL. Conclusions We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention
Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial
Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials.
Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure.
Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.
Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
Use failure mode and effects analysis to evaluate Green University Policies\uef\ubcA Case Study of National Sun Yat-sen University
Transmission dynamics and control for indoor respiratory infections of measles and influenza
本論文之目的為提供一整合性數學模式以描述室內呼吸性傳染病麻疹與流感之傳輸動態、控制策略模擬及成本效益分析。本架構之基礎資料包括季節性流感之流行病學資料與麻疹疫苗前後之全國/山區/鄉村/都市之血清流行病學資料。第一部分,本研究以三個相異之接觸矩陣(Who Acquire Infection From Who,WAIFW描述在不同年齡族群中及不同年齡族群之間的麻疹傳染率,量化疫苗前後因年齡而異之感染力與基本再生數(Basic reproduction number,R0),而後,結合一標準之易感–暴露–感染–復原(Susceptible-Exposed-Infective-Recovery,SEIR)模式,以一簡易之一階常微分方程式,明確地模擬麻疹疫苗施行後,傳染發生之族群動態。
其次,本研究利用一機制模式Wells-Riley數學方程式推測學校孩童於通風空間中之流行性感冒感染機率,依據通風空間中之環境影響因子(如空間大小與通風率)及傳染者之影響因子(如人體呼吸率與暴露於通風空間中之時間),可推測出季節性且因年齡而異之感染風險與基本再生數。本研究亦結合Wells-Riley數學方程式與競爭風險(Competing-risks)模式,量化學校孩童暴露於學校之環境下,採取控制策略對於室內環境流感發生之衝擊,探討以室內通風為基礎之工程控制與個人保護方法之影響,更進一步研擬以Von Foerster方程式加以量化公共衛生策略包含流感疫苗與隔離政策施行之衝擊。因此,藉由上述之Wells-Riley數學方程式、Competing-risks模式及Von Foerster方程式之整合,可建立ㄧ關鍵之R0 – θ控制曲線以最佳化研擬控制策略之衝擊,其中θ表示未發生症狀而可傳染的期間除以可傳染總時間長度之比例。
第三部份,本研究發展一套以成本效益為基礎之整合性數學模式,以模擬季節性流感之發生。針對工程控制方法(如室內通風、紫外光殺菌燈及高效率顆粒過濾網)、個人保護方法(如口罩與洗手)及公共衛生策略(如疫苗施行與隔離政策)之控制效率與成本加以整理蒐集以利進行成本-效益分析,並以資源使用最小化、平均每人負擔之成本功效最大化為目標,建立出因應季節性變異之最佳化流感控制策略。
本研究結果指出區域性或全國性之疫苗計畫可大幅降低麻疹流行之主要衝擊。成本-效益分析可利用於評估多種整合性控制策略對於季節性流感之衝擊,本研究可提供一個完整且已量化之麻疹與流感傳輸動態,藉由結合室內呼吸性傳染病之傳輸機制、控制策略之衝擊研擬,與成本-效益分析之整合性方法,對於預測學校孩童感染流感將會是個強而有力的工具。The objective of this dissertation is to provide an integrated relevant mathematical model for describing the transmission dynamics, control measures modeling, and cost-effectiveness analysis for indoor respiratory infections including measles and influenza. The empirical evidence of proposed framework is based on the seasonal epidemiological data of influenza and robust age-stratified seroepidemiological data of measles for pre/post-vaccination and setting of nationwide/mountain/rural/urban. In the first phase, three contact patterns of “who acquire infection from who” (WAIFW) matrices are employed to characterize the transmission rate within and between each age group and subsequently the parameters of age-dependent force of infection and age-dependent basic reproduction number (R0) for measles can be quantified. A standard susceptible-exposed-infected-recovery (SEIR) structure can model straightforwardly the dynamics of measles vaccination by using a simple parameterized set of differential equations.
Secondly, Wells-Riley mathematical model is used to predict the influenza infection risk in terms of environmental factors (e.g., room size and ventilation rate) and host factors (e.g., breathing rate and exposure time) and to estimate seasonal-specific age-dependent risk of infection and R0. This study integrates the Wells-Riley mathematical equation and competing-risks model to quantify the impact of combination efforts of indoor air-based engineering and personal protection control measures in containing pandemic influenza within an elementary school. Public health interventions including vaccination and isolation are modeled based on the Von Foerster equation for schoolchildren infected influenza. Then, a critical R0 –θ control line constructed by integrating the Wells-Riley equation, competing-risks model, and the Von Foerster equation, is used to prioritize control measure efforts. The symbol θ,asymptomatic proportion, can be defined as the ratio of the asymptomatic infection over the summation of symptomatic and asymptomatic infection.
In the third phase, an integrated mathematical model linking with the cost-effectiveness-based control methods is developed for preventing from seasonal influenza in an elementary school. The costs and effectiveness of engineering control measurers (ventilation, ultraviolet germicidal irradiation, high-efficiency particulate air filter), personal protection (respiratory masking and handwashing), and public interventions (vaccination and isolation) were collected to perform the cost-effectiveness analysis to minimize the waste of resource and to maximize the health per dollar spent because the seasonal variation in disease transmission may play an important role on modeling the optimal control measures on influenza.
In the present study, the results indicate that the mass regional or nationwide vaccination programmes could greatly reduce the potential for a major measles epidemic. The cost-effectiveness analysis is useful for evaluating the multiple control measures on seasonal influenza. This work can provide a quantitative understanding of the transmission dynamics of measles and influenza. The proposed integrated approach, by employing the mechanism of transmission of indoor respiratory infection, the impact of infectious control programs, and the cost-effectiveness analysis, is a powerful tool for risk profiling prediction of pandemic influenza among schoolchildren.TABLE OF CONTENTS
口試委員會審定書 I
誌謝 II
中文摘要 VI
ABSTRACT VIII
TABLE OF CONTENTS X
LIST OF TABLES XIII
LIST OF FIGURES XV
NOMENCLATURE XXIII
CHAPTER I. INTRODUCTION 1
CHAPTER II. MOTIVATION AND RESEARCH OBJECTIVES 3
2.1. Motivation 3
2.2. Research Objectives 6
CHAPTER III. LITERATURE REVIEW 7
3.1. Indoor Respiratory Infections 7
3.1.1. Measles 7
3.1.2. Influenza 16
3.2. Mathematical Models 23
3.2.1. Infectious disease modeling 23
3.2.1.1. Who acquires infection from whom
(WAIFW) matrix model 27
3.2.1.2. Susceptible-infected-recovery (SIR) model 31
3.2.1.3. Wells-Riley mathematical equations 35
3.2.2. Control measure modeling 40
3.2.2.1. Competing-risks model 40
3.2.2.2. Von Foerst equation 42
3.3. Control Measures 44
3.3.1. Engineering control 44
3.3.2. Personal protection 47
3.3.3. Public health intervention 48
CHAPTER IV. MATERIALS AND METHODS 50
4.1. Modeling Vaccination Programmes Against Measles 50
4.1.1. Quantitative seroepidemiological data 50
4.1.2. Age-specific force of infection (FOI) 54
4.1.3. WAIFW matrix contact pattern model 55
4.1.4. Vaccination dynamics 58
4.2. Modeling Pandemic Influenza Among Schoolchildren 60
4.2.1. Study population 60
4.2.2. Transmission dynamics 63
4.2.3. Control measure modeling 67
4.3. Modeling Seasonal Influenza and Cost-Effectiveness Analysis 69
4.3.1. Quantitative epidemiological data 69
4.3.2. R0 – θ control line 71
4.3.3. Cost and efficacies of control measure 78
CHAPTER V. RESULTS AND DISCUSSION 81
5.1. Vaccination Programmes against Measles 81
5.1.1. Age-specific FOI 81
5.1.2. Age/population-specific R0 estimates 87
5.1.3. Measles vaccination effectiveness on R0 93
5.1.4. Pre- and postvaccination dynamics 95
5.1.5 Discussion 97
5.2. Pandemic Influenza Among Schoolchildren 101
5.2.1. Age-specific R0 estimates 101
5.2.2. Single control measure efforts 104
5.2.3. Multiple control measure efforts 113
5.3. Seasonal Influenza and Cost-Effectiveness Analysis 117
5.3.1. Seasonal influenza incidence 117
5.3.2. Control measure combinations 123
5.3.3. Dynamic modeling 136
5.3.4. Cost-effectiveness analysis 138
5.3.5. Discussion 144
CHAPTER VI. CONCLUSIONS 147
CHAPTER VII. SUGGESTIONS FOR FUTURE RESEARCH 149
APPENDIX A: MEASLES SEROEPIDEMIOLOGICAL DATA 150
BIBLIOGRAPHY 154
CURRICULUM VITAE 17
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