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Featured researches published by Yi Fang Tu.


Critical Care | 2006

Serum total antioxidant capacity reflects severity of illness in patients with severe sepsis.

Chia Chang Chuang; Shu Chu Shiesh; Chih Hsien Chi; Yi Fang Tu; Lien I. Hor; Chi Chang Shieh; Ming Feng Chen

IntroductionWe conducted the present study to evaluate the changes in serum total antioxidant capacity (TAC) in patients with severe sepsis and to investigate the association between serum TAC and clinical severity.MethodThis was a prospective observational study involving a sample of patients who met established criteria for severe sepsis and were admitted to the emergency department of a university teaching hospital. Serum TAC was determined using the total radical-trapping antioxidant parameter method. The levels of TAC, uric acid, albumin, and bilirubin in sera were obtained in the emergency department and evaluated to determine whether there were any correlations between the major antioxidant biomarkers and clinical severity of sepsis. The Acute Physiology and Chronic Health Evaluation (APACHE) II score was used for clinical evaluation of the severity of sepsis.ResultsA total of 73 patients with sepsis, with a mean (± standard deviation) APACHE II score of 23.2 ± 8.2 and a mortality rate of 26.0%, were included. Seventy-six healthy individuals served as control individuals. Among the patients, serum TAC levels correlated significantly with APACHE II scores. Patients who died also had higher TAC than did those who survived. Serum uric acid levels correlated significantly with serum TAC and APACHE II scores in patients with severe sepsis.ConclusionElevated serum TAC level may reflect clinical severity of sepsis. In addition, serum uric acid levels appear to contribute importantly to the higher TAC levels observed in patients with severe sepsis.


Journal of Neuroinflammation | 2012

JNK signaling is the shared pathway linking neuroinflammation, blood-brain barrier disruption, and oligodendroglial apoptosis in the white matter injury of the immature brain.

Lan Wan Wang; Yi Fang Tu; Chao Ching Huang; Chien Jung Ho

BackgroundWhite matter injury is the major form of brain damage in very preterm infants. Selective white matter injury in the immature brain can be induced by lipopolysaccharide (LPS)-sensitized hypoxic-ischemia (HI) in the postpartum (P) day 2 rat pups whose brain maturation status is equivalent to that in preterm infants less than 30 weeks of gestation. Neuroinflammation, blood–brain barrier (BBB) damage and oligodendrocyte progenitor apoptosis may affect the susceptibility of LPS-sensitized HI in white matter injury. c-Jun N-terminal kinases (JNK) are important stress-responsive kinases in various forms of insults. We hypothesized that LPS-sensitized HI causes white matter injury through JNK activation-mediated neuroinflammation, BBB leakage and oligodendroglial apoptosis in the white matter of P2 rat pups.MethodsP2 pups received LPS (0.05 mg/kg) or normal saline injection followed by 90-min HI. Immunohistochemistry and immunoblotting were used to determine microglia activation, TNF-α, BBB damage, cleaved caspase-3, JNK and phospho-JNK (p-JNK), myelin basic protein (MBP), and glial fibrillary acidic protein (GFAP) expression. Immunofluorescence was performed to determine the cellular distribution of p-JNK. Pharmacological and genetic approaches were used to inhibit JNK activity.ResultsP2 pups had selective white matter injury associated with upregulation of activated microglia, TNF-α, IgG extravasation and oligodendroglial progenitor apoptosis after LPS-sensitized HI. Immunohistochemical analyses showed early and sustained JNK activation in the white matter at 6 and 24 h post-insult. Immunofluorescence demonstrated upregulation of p-JNK in activated microglia, vascular endothelial cells and oligodendrocyte progenitors, and also showed perivascular aggregation of p-JNK-positive cells around the vessels 24 h post-insult. JNK inhibition by AS601245 or by antisense oligodeoxynucleotides (ODN) significantly reduced microglial activation, TNF-α immunoreactivity, IgG extravasation, and cleaved caspase-3 in the endothelial cells and oligodendrocyte progenitors, and also attenuated perivascular aggregation of p-JNK-positive cells 24 h post-insult. The AS601245 or JNK antisense ODN group had significantly increased MBP and decreased GFAP expression in the white matter on P11 than the vehicle or scrambled ODN group.ConclusionsLPS-sensitized HI causes white matter injury through JNK activation-mediated upregulation of neuroinflammation, BBB leakage and oligodendrocyte progenitor apoptosis in the immature brain.


The Journal of Neuroscience | 2009

VEGF-A/VEGFR-2 signaling leading to cAMP response element-binding protein phosphorylation is a shared pathway underlying the protective effect of preconditioning on neurons and endothelial cells.

Hsueh-Te Lee; Ying Chao Chang; Yi Fang Tu; Chao Ching Huang

Preconditioning protects endothelial cells as well as neurons from ischemic injury. In 7-d-old rat pups, ligating the carotid artery 1 h before hypoxia damaged the ipsilateral cerebral hemisphere; in contrast, ligating the artery 24 h before hypoxia provided complete neuroprotection. The protective effect of the 24 h artery ligation preconditioning model requires the activation of cAMP response element-binding protein (CREB). We tested the hypothesis that vascular endothelial growth factor (VEGF)-A/VEGF receptor-2 (VEGFR-2) signaling that leads to CREB activation is the shared pathway underlying the protective effect of preconditioning in neurons and endothelial cells. VEGF-A, VEGFR-1, or VEGFR-2 was inhibited by antisense oligodeoxynucleotides (ODNs) in vivo and by a VEGF-A neutralizing antibody or VEGFR-2 inhibitor in vitro. CREB phosphorylation (pCREB) and VEGF-A and VEGFR-2 expression were increased and colocalized in vascular endothelial cells and neurons in the ipsilateral cerebral cortex 24 h after ligation. The antisense ODN blockades of VEGF-A and VEGFR-2 decreased pCREB and reduced the protection of 24 h ligation preconditioning. Furthermore, oxygen-glucose deprivation (OGD) preconditioning upregulated VEGF-A, VEGFR-2, and pCREB levels and protected immortalized H19-7 neuronal cells and b.End3 vascular endothelial cells against 24 h OGD cell death. Blocking VEGF-A or VEGFR-2 reduced CREB activation and the effects of OGD preconditioning in neuronal cells and endothelial cells. Transfecting a serine-133 phosphorylation mutant CREB also inhibited the protective effect of OGD preconditioning. We conclude that VEGF-A/VEGFR-2 signaling leading to CREB phosphorylation is the shared pathway underlying the preconditioning-induced protective effect in neurons and vascular endothelial cells in the developing brain.


Journal of Neuroinflammation | 2011

Overweight worsens apoptosis, neuroinflammation and blood-brain barrier damage after hypoxic ischemia in neonatal brain through JNK hyperactivation.

Yi Fang Tu; Yau Sheng Tsai; Lan Wan Wang; Hsin Chieh Wu; Chao Ching Huang; Chien Jung Ho

BackgroundApoptosis, neuroinflammation and blood-brain barrier (BBB) damage affect the susceptibility of the developing brain to hypoxic-ischemic (HI) insults. c-Jun N-terminal kinase (JNK) is an important mediator of insulin resistance in obesity. We hypothesized that neonatal overweight aggravates HI brain damage through JNK hyperactivation-mediated upregulation of neuronal apoptosis, neuroinflammation and BBB leakage in rat pups.MethodsOverweight (OF) pups were established by reducing the litter size to 6, and control (NF) pups by keeping the litter size at 12 from postnatal (P) day 1 before HI on P7. Immunohistochemistry and immunoblotting were used to determine the TUNEL-(+) cells and BBB damage, cleaved caspase-3 and poly (ADP-ribose) polymerase (PARP), and phospho-JNK and phospho-BimEL levels. Immunofluorescence was performed to determine the cellular distribution of phospho-JNK.ResultsCompared with NF pups, OF pups had a significantly heavier body-weight and greater fat deposition on P7. Compared with the NF-HI group, the OF-HI group showed significant increases of TUNEL-(+) cells, cleaved levels of caspase-3 and PARP, and ED1-(+) activated microglia and BBB damage in the cortex 24 hours post-HI. Immunofluorescence of the OF-HI pups showed that activated-caspase 3 expression was found mainly in NeuN-(+) neurons and RECA1-(+) vascular endothelial cells 24 hours post-HI. The OF-HI group also had prolonged escape latency in the Morris water maze test and greater brain-volume loss compared with the NF-HI group when assessed at adulthood. Phospho-JNK and phospho-BimEL levels were higher in OF-HI pups than in NF-HI pups immediately post-HI. JNK activation in OF-HI pups was mainly expressed in neurons, microglia and vascular endothelial cells. Inhibiting JNK activity by AS601245 caused more attenuation of cleaved caspase-3 and PARP, a greater reduction of microglial activation and BBB damage post-HI, and significantly reduced brain damage in OF-HI than in NF-HI pups.ConclusionsNeonatal overweight increased HI-induced neuronal apoptosis, microglial activation and BBB damage, and aggravated HI brain damage in rat pups through JNK hyperactivation.


Stroke | 2012

Moderate Dietary Restriction Reduces p53-Mediated Neurovascular Damage and Microglia Activation After Hypoxic Ischemia in Neonatal Brain

Yi Fang Tu; Pei Jung Lu; Chao Ching Huang; Chien Jung Ho; Ya Ping Chou

Background and Purpose— Neurovascular damage, including neuronal apoptosis and blood–brain barrier (BBB) damage, and microglia activation account for the hypoxic-ischemia (HI) susceptibility in neonatal brain. The p53 upregulation is involved in apoptosis, endothelial cell damage, and microglia activation. We hypothesized that underweight induced by dietary restriction (DR) protects against HI in rat pups by attenuating p53-mediated neurovascular damage. Methods— Male rat pups were grouped as normal litter (NL) size (12 pups/dam), DR (18 pups/dam), and extreme DR (24 pups/dam) from postnatal day 1 and subjected to HI on postnatal day 7. Immunohistochemistry and immunoblotting were used to determine p53, phospho-murine double minute-2, caspases, BBB damage and microglia activation, and immunofluorescence to determine the cellular distribution of p53. Pharmacological approaches were used to regulate p53. Results— The NL, DR, and extreme DR pups had similar TUNEL-positive cells and caspases on postnatal day 7 and comparable learning performance at adulthood. After HI, the DR-HI, but not extreme DR-HI, pups had significantly lower p53, higher phospho-murine double minute-2, lower cleaved caspases, less BBB damage and microglia activation, and less brain volume loss than NL-HI pups. In NL-HI pups, p53 expression was located mainly in the neurons, endothelial cells, and microglia. The p53 blockage by pifithrin-&agr; in NL-HI pups decreased apoptosis, BBB damage, and microglia activation, and was neuroprotective. In contrast, upregulating p53 by nutlin-3 in DR-HI pups increased apoptosis, BBB damage, and microglia activation, and worsened brain damage. Conclusions— Moderate DR, but not extreme DR, reduces p53-mediated neurovascular damage after HI and confers long-term protection in neonatal brain.


Journal of Neurochemistry | 2010

CREB activation mediates VEGF-A's protection of neurons and cerebral vascular endothelial cells.

Hsueh-Te Lee; Ying Chao Chang; Yi Fang Tu; Chao Ching Huang

J. Neurochem. (2010) 10.1111/j.1471‐4159.2010.06584.x


Medicine | 2015

An Increased Risk of Reversible Dementia May Occur After Zolpidem Derivative Use in the Elderly Population: A Population-Based Case-Control Study

Hsin I. Shih; Che Chen Lin; Yi Fang Tu; Chia Ming Chang; Hsiang Chin Hsu; Chih Hsien Chi; Chia-Hung Kao

AbstractWe evaluate the effects of zolpidem use to develop dementia or Alzheimer disease from the Taiwan National Health Insurance Research Database (NHIRD).A retrospective population-based nested case–control study. Newly diagnosed dementia patients 65 years and older and controls were sampled. A total of 8406 dementia and 16,812 control subjects were enrolled from Taiwan NHIRD during 2006 to 2010. The relationships between zolpidem use and dementia were measured using odds and adjusted odds ratios. The relationship between the average cumulative doses for zolpidem and dementia was also analyzed.Zolpidem alone or with other underlying diseases, such as hypertension, diabetes, and stroke, was significantly associated with dementia after controlling for potential confounders, such as age, sex, coronary artery disease, diabetes, anti-hypertension drugs, stroke, anticholesterol statin drugs, depression, anxiety, benzodiazepine, anti-psychotic, and anti-depressant agents’ use (Adjusted OR = 1.33, 95% CI 1.24–1.41). Zolpidem use also has significant dose–response effects for most of the types of dementia. In patient with Alzheimer diseases, the effects of zolpidem among patients with Alzheimers disease remained obscure. The adjusted OR for patients whose cumulative exposure doses were between 170 and 819 mg/year (adjusted OR: 1.65, 95% CI 1.08–2.51, P = 0.0199) was significant; however, the effects for lower and higher cumulative dose were not significant.Zolpidem used might be associated with increased risk for dementia in elderly population. Increased accumulative dose might have higher risk to develop dementia, especially in patients with underlying diseases such as hypertension, diabetes, and stroke.


American Journal of Emergency Medicine | 2013

Electrolyte abnormalities and laboratory findings in patients with out-of-hospital cardiac arrest who have kidney disease

Chih-Hao Lin; Yi Fang Tu; Wen-Chu Chiang; Shyu Yu Wu; Ying Hsin Chang; Chih Hsien Chi

PURPOSES Although electrolyte abnormalities have been generally considered the major cause of out-of-hospital cardiac arrest (OHCA) in patients with kidney disease (KD), this association has never been prospectively validated. METHODS A prospective, observational study was conducted in a tertiary university hospital between January 2008 and December 2009. The study sample consisted of consecutively admitted patients with nontraumatic OHCA. Based on the estimated glomerular filtration rate (eGFR, unit: milliliters per minute per 1.73 m(2)), the enrollees were divided into 3 groups: group A (normal kidney function or mild KD; eGFR, 60.0), group B (moderate KD; eGFR between 15.0 and 59.9), and group C (severe KD; eGFR<15.0 or on dialysis). The laboratory findings of the groups were compared. Two-tailed P values less than .005 were considered significant. RESULTS Two hundred thirty-four enrollees (137 were male) were divided into 3 groups: group A (n = 51; 21.8%), group B (n = 128; 54.7%), and group C (n = 55; 23.5%). Compared with the other 2 groups, group C presented significantly higher serum potassium and magnesium and lower pH and hemoglobin level (all P < .005). After stratifications of the significant variables, a post hoc analysis revealed that group C presented significantly higher incidences of hypermagnesemia (Mg >2.5 mmol/L) and severe hyperkalemia (K >6.5 mmol/L) (both P < .005) than the other 2 groups. The odds ratios of the incidence of severe hyperkalemia in group C was 3.37 (95% confidence intervals, 1.46-7.77) compared with group A (50.9% vs 23.5%, P < .005). CONCLUSIONS Severe hyperkalemia is common in patients with OHCA who have severe KD and should be considered during resuscitation for these patients.


PLOS ONE | 2016

Applications of a rapid and sensitive dengue DUO rapid immunochromatographic test kit as a diagnostic strategy during a dengue type 2 Epidemic in an Urban City

Hsin I. Shih; Hsiang Chin Hsu; Chi Jung Wu; Chih-Hao Lin; Chia Ming Chang; Yi Fang Tu; Chih Chia Hsieh; Chih Hsien Chi; Tzu Ching Sung

Dengue infection is a major health problem in tropical and subtropical countries. A prospective observational study in a university-affiliated hospital was conducted between August 2015 and September 2015. Patients who visited the emergency department (ED) with a presentation of any symptoms of dengue were eligible for the dengue non-structural protein 1 (NS1), IgM/IgG rapid immunochromatographic tests and real-time polymerase chain reaction (RT-PCR) to evaluate the performance of the rapid tests. Considering the RT-PCR as the gold standard for the dengue diagnosis, the ideal primary results of sensitivity (80–100%), specificity (60–84%), positive predicted value(75%-95%), and negative predicted value (70–100%) suggested that the NS1-based test with or without a combination of IgM and IgG tests have good diagnostic performances in detecting dengue infections, even in the afebrile or elderly populations.


European Radiology | 2005

Neonatal neurological disorders involving the brainstem: neurosonographic approaches through the squamous suture and the foramen magnum

Yi Fang Tu; Cheng Yu Chen; Yuh Jey Lin; Ying Chao Chang; Chao Ching Huang

Brainstem damage which often indicates a critical condition is usually underestimated by trans-anterior-fontanel neurosonography (NS) owing to the far-field limitations. Instead, NS alternately scanning through the squamous suture of the temporal bones and the foramen magnum could provide a better visualization of the brainstem structures. The NS characteristics of brainstem lesions caused by various neonatal neurological disorders, such as hypoxic–ischemic encephalopathy (HIE), metabolic encephalopathy, birth trauma and bacterial meningoencephalitis, can be depicted at the acute stage. An echogenic change in the midbrain was found in patients with HIE or metabolic encephalopathy. In addition to the echogenic change, bilateral transtentorial temporal lobe herniation distorting the contour of the midbrain was observed in a patient with group B streptococcus meningoencephalitis, whereas echogenic changes at the level of the pons and/or the medulla oblongata, mainly localized in the dorsal part, could be observed in newborns with severe HIE, maple syrup urine disease or birth trauma. In this pictorial assay, we demonstrate the feasibility of NS imaging in evaluating the entire brainstem structure of critically ill neonates in the near field and illustrate the characteristic features of brainstem involvement in various neonatal neurological disorders along with computed tomography or magnetic resonance imaging correlation.

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Chao Ching Huang

National Cheng Kung University

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Chien Jung Ho

National Cheng Kung University

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Lan Wan Wang

National Cheng Kung University

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Chih Hsien Chi

National Cheng Kung University

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Ying Chao Chang

Kaohsiung Medical University

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Hsin I. Shih

National Cheng Kung University

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Li Wen Chen

National Cheng Kung University

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Shan Tair Wang

National Cheng Kung University

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Cheng Yu Chen

National Defense Medical Center

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Chia Ming Chang

National Cheng Kung University

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