993 research outputs found

    Oral health status of asthmatic preschoolers in Hong Kong

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    An increase in adenosine-5’-triphosphate (ATP) content in rostral ventrolateral medulla is engaged in the high fructose diet-induced hypertension

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    BACKGROUND: The increase in fructose ingestion has been linked to overdrive of sympathetic activity and hypertension associated with the metabolic syndrome. The premotor neurons for generation of sympathetic vasomotor activity reside in the rostral ventrolateral medulla (RVLM). Activation of RVLM results in sympathoexcitation and hypertension. Neurons in the central nervous system are able to utilize fructose as a carbon source of ATP production. We examined in this study whether fructose affects ATP content in RVLM and its significance in the increase in central sympathetic outflow and hypertension induced by the high fructose diet (HFD). RESULTS: In normotensive rats fed with high fructose diet (HFD) for 12 weeks, there was a significant increase in tissue ATP content in RVLM, accompanied by the increases in the sympathetic vasomotor activity and blood pressure. These changes were blunted by intracisternal infusion of an ATP synthase inhibitor, oligomycin, to the HFD-fed animals. In the catecholaminergic-containing N2a cells, fructose dose-dependently upregulated the expressions of glucose transporter 2 and 5 (GluT2, 5) and the rate-limiting enzyme of fructolysis, ketohexokinase (KHK), leading to the increases in pyruvate and ATP production, as well as the release of the neurotransmitter, dopamine. These cellular events were significantly prevented after the gene knocking down by lentiviral transfection of small hairpin RNA against KHK. CONCLUSION: These results suggest that increases in ATP content in RVLM may be engaged in the augmented sympathetic vasomotor activity and hypertension associated with the metabolic syndrome induced by the HFD. At cellular level, the increase in pyruvate levels via fructolysis is involved in the fructose-induced ATP production and the release of neurotransmitter

    Modeling COVID-19 Spread Using an Agent-Based Network

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    Beginning in 2019 and quickly spreading internationally, the Coronavirus disease Covid-19 became the first pandemic that many people have witnessed firsthand along with the severe disruption to their daily lives. A key field of research for Covid-19 that is studied by epidemiologists, biologists, and computer scientists alike is modeling the spread of Covid-19 in order to better predict future outbreaks of the pandemic and evaluate potential strategies to reduce infections, hospitalizations, and deaths. This thesis proposes a method of modeling Covid-19 spread and interventions for local environments based on different levels of perspective. The goal for this thesis is to be able to present a model of Covid-19 in terms of surrounding areas in San Luis Obispo including the unique mobility dynamic currently held in the global pandemic. Furthermore, we use our model to explore different methods of ensuring a low infection rate such as isolation methods and mobility restrictions

    Effect of taurine on toxicity of oxidized cholesterol and oxidized fish oil in rats

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    [[abstract]]Taurine (2-aminoethanesulfonic acid) Occurs naturally in food, especially in seafood and meat. The aim of our investigation was to evaluate the effect of dietary taurine on oxidized cholesterol and oxidized fish oil induced toxicity in male Wistar rats. Thirty male wistar rats were fed with diets supplemented with 5% taurine, 2% oxidized cholesterol or 3% oxidized fish oil for 6 weeks. After feeding such diet, taurine could increase the high density lipoprotein-cholesterol (HDL-C) level in plasma, and glutathione (GSH) level in plasma, and decrease the activities of alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) in plasma, and the levels of low density lipoprotein-cholesterol (LDL-C), very low density lipoprotein-cholesterol (VLDL-C), triglyceride, total cholesterol in plasma, and relative ratios of liver weight to body weight and thiobarbituric acid-reactive substances (TBARS.) level in the rat liver caused by oxidized cholesterol and oxidized fish oil. It could reduce the biochemical parameters characteristic in the plasma and rate liver caused by oxidized cholesterol and oxidized fish oil. It was also found that taurine possessed a good recovering effect and a short-term preventing effect from the toxicity of oxidized cholesterol and oxidized fish oil in rats. The results suggest that taurine may play an important role in suppressing effect by oxidized cholesterol and oxidized fish oil induced toxicity in rats

    Short-term toxicity of aristolochic acid, aristolochic acid-I and aristolochic acid-II in rats

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    [[abstract]]We compared the short-term toxicity of toxic components of aristolochic acid in rats. Twenty-four female Wistar rats were divided into 4 groups and treated orally every 3-days with 10 mg/kg each of aristolochic acid, aristolochic acid-I and aristolochic acid-II for 19 days. After treatment, the relative ratio of liver and kidney weight to body weight, the concentrations of RBC, hemoglobin and hematocrit in the blood, the levels of aspartate amino transferase, alanine amino transferase, alkaline phosphatase, blood urea, nitrogen and creatinine in the plasma, and the levels of urinary urea nitrogen and creatinine in the urine were significantly increased. Body weight of rats and the levels of Na+, K+, Ca2+ in the urine were significantly decreased, especially for groups treated with aristolochic acid and aristolochic acid-II. Pathological examination of liver and kidney also showed cell enlargement and lesions, especially for groups treated with aristolochic acid and aristolochic acid-II. The aristolochic acid exhibited significant toxicity, and the short-term toxicity of aristolochic acid-II and aristolochic acid was similar to each other. Renal but not hepatic failure induced by aristolochic: acid could be prevented by pentoxifylline. (c) 2007 Elsevier Ltd. All rights reserved

    Dietary Caffeic Acid, Ferulic Acid and Coumaric Acid Supplements on Cholesterol Metabolism and Antioxidant Activity in Rats

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    [[abstract]]This study was designed to test the lipid-lowering and antioxidative activities of three phenolic compounds, caffeic acid, ferulic acid and coumaric acid. Four groups of rats were given a semisynthetic diet containing 3% of cholesterol for 6 weeks. The control group only received a high cholesterol diet, whereas the other three groups received a diet including 0.2% of caffeic acid, 0.2% of ferulic acid and 0.2% of coumaric acid. The caffeic acid, ferulic acid and coumaric acid significantly lowered the plasma lipid and hepatic cholesterol levels compared to those in the control (p < 0.05). The hepatic HMG-CoA reductase activity was significantly lower in the caffeic acid group than in the ferulic acid and coumaric acid groups (p < 0.05), while the hepatic ACAT activity was significantly lower in the caffeic acid, ferulic acid and coumaric acid groups compared to the control group (p < 0.05). The overall potential of the antioxidant system was significantly enhanced by the caffeic acid, ferulic acid and coumaric acid supplements as the plasma and hepatic TBARS levels were lowered while the hepatic SOD activities and GSH concentration were elevated in the high-cholesterol-fed rats (p < 0.05). Furthermore, these results indicated that the supplementation of caffeic acid, ferulic acid and coumaric acid boosted the antioxidant activity in rats and promoted the excretion of neutral sterol and acidic sterol (p < 0.05), thereby leading to a decreased absorption of dietary cholesterol as well as lower plasma, hepatic cholesterol and promoted excretion of fecal sterols

    Effect of taurine on toxicity of oxidized cholesterol in rats

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    [[abstract]]This research was aimed to study the effect of dietary taurine on the toxicity of oxidized cholesterol in male Wistar rats. The rats were divided into eight groups and fed different diets with or without supplement of 5% taurine and 3% oxidized cholesterol for 8 weeks. To evaluate effects of taurine at the same time, before diets and after diets in the food, after feeding diet with 3% oxidized cholesterol and 5% taurine at the same time, taurine could improve the decrease of body weight and the glutathione (GSH) level in the liver, and the increase of relative ratio of liver or kidney weight to body weight and thiobarbituric acid-reactive substances (TBARS) level in the liver of rats caused by oxidized cholesterol (P < 0.05). It also could inhibit the activities of aspartate transaminase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP) in the plasma of rats caused by oxidized cholesterol (P < 0.05). It was also found that taurine possessed a good recovering effect and a short-term preventing effect the toxicity of oxidized cholesterol in rats. Judging from these data, on taurine may play an important role in diminishing the toxic effect of oxidized cholesterol in rats

    Emotional Fuzzy Sliding-Mode Control for Unknown Nonlinear Systems

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    [[abstract]]The brain emotional learning model can be implemented with a simple hardware and processor; however, the learning model cannot model the qualitative aspects of human knowledge. To solve this problem, a fuzzy-based emotional learning model (FELM) with structure and parameter learning is proposed. The membership functions and fuzzy rules can be learned through the derived learning scheme. Further, an emotional fuzzy sliding-mode control (EFSMC) system, which does not need the plant model, is proposed for unknown nonlinear systems. The EFSMC system is applied to an inverted pendulum and a chaotic synchronization. The simulation results with the use of EFSMC system demonstrate the feasibility of FELM learning procedure. The main contributions of this paper are (1) the FELM varies its structure dynamically with a simple computation; (2) the parameter learning imitates the role of emotions in mammalians brain; (3) by combining the advantage of nonsingular terminal sliding-mode control, the EFSMC system provides very high precision and finite-time control performance; (4) the system analysis is given in the sense of the gradient descent method.[[notice]]補正完
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