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1.
J Biomed Opt ; 29(4): 046008, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38659998

ABSTRACT

Significance: Optical imaging is a non-invasive imaging technology that utilizes near-infrared light, allows for the image reconstruction of optical properties like diffuse and absorption coefficients within the tissue. A recent trend is to use signal processing techniques or new light sources and expanding its application. Aim: We aim to develop the reflective optical imaging using the chaotic correlation technology with chaotic laser and optimize the quality and spatial resolution of reflective optical imaging. Approach: Scattering medium was measured using reflective configuration in different inhomogeneous regions to evaluate the performance of the imaging system. The accuracy of the recovered optical properties was investigated. The reconstruction errors of absorption coefficients and geometric centers were analyzed, and the feature metrics of the reconstructed images were evaluated. Results: We showed how chaotic correlation technology can be utilized for information extraction and image reconstruction. This means that a higher signal-to-noise ratio and image reconstruction of inhomogeneous phantoms under different scenarios successfully were achieved. Conclusions: This work highlights that the peak values of correlation of chaotic exhibit smaller reconstruction error and better reconstruction performance in optical imaging compared with reflective optical imaging with the continuous wave laser.


Subject(s)
Image Processing, Computer-Assisted , Lasers , Optical Imaging , Phantoms, Imaging , Scattering, Radiation , Optical Imaging/methods , Image Processing, Computer-Assisted/methods , Signal-To-Noise Ratio , Nonlinear Dynamics , Algorithms , Equipment Design
2.
Opt Express ; 32(7): 12496-12507, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38571070

ABSTRACT

A diffuse optical tomography system with chaotic laser is proposed for the three-dimensional optical phantom. The high signal-to-noise ratio is beneficial to improve the spatial resolution of diffuse optical tomography. It is essential to drive the chaotic laser as the incident light into the optical phantom. The transmitted light emitted from phantom as the detection light and a part of the incident light as the reference light to carry out cross-correlation analysis. The high-density source-detector configuration in parallel plate structure is designed for detecting targets in the phantom. The propagation of chaotic laser in the phantom is studied theoretically and experimentally based on the diffusion equation. Image reconstruction is achieved by the cross-correlation analysis of chaotic laser and the Newton-Raphson nonlinear algorithm. The performance of the proposed system has been assessed by reconstruction localization accuracy and contrast-noise-ratio. The results show that the spatial resolution of the proposed system can reach 1.5 mm and the localization error is less than 1 mm.

3.
iScience ; 27(4): 109430, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38550992

ABSTRACT

An up-to-date comprehensive assessment of the cancer burden attributable to risk factors is essential for cancer prevention. We analyzed the population attributable fraction (PAF) of cancer disability-adjusted life years (DALYs) attributable to 11 level 2 risk factors using data from the Global Burden and Disease Study (GBD) 2019. We highlighted that almost half of the cancer DALYs can be preventable by modifying relevant risk factors. The attributable cancer DALYs increased by 60.42%-105.0 million from 1990 to 2019. Tobacco, dietary risks, alcohol use, high body-mass index, and air pollution were the top five risk factors. The PAFs attributable to high fasting plasma glucose, high body-mass index, and low physical activity have increased worldwide from 1990 to 2019. Unsafe sex was the leading risk factor for women before age of 54. Tailored prevention programs targeted at specific populations should be scaled up to reduce the cancer burden in the future.

4.
Sci Total Environ ; 917: 170200, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38296065

ABSTRACT

Ultraviolet (UV) light is widely used for wastewater disinfection. Traditional electrode-excited UV lamps, such as low-pressure mercy lamps (LPUV), encounter drawbacks like electrode aging and rapid light attenuation. A novel UV source of microwave discharge electrodeless lamp (MDEL) has aroused attention, yet its disinfection performance is unclear and still far from practical application. Here, we successfully developed a complete piece of equipment based on MDELs and achieved the application for disinfection in wastewater treatment plants (WWTPs). The light emitted by an MDEL (MWUV) shared a spectrum similar to that of LPUV, with the main emission wavelength at 254 nm. The inactivation rate of Gram-negative E. coli by MWUV reached 4.5 log at an intensity of 1.6 mW/cm2 and a dose of 20 mJ/cm2. For Gram-positive B. subtilis, an MWUV dose of 50 mJ/cm2 and a light intensity of 1.2 mW/cm2 reached an inactivation rate of 3.4 log. A higher MWUV intensity led to a better disinfection effect and a lower photoreactivation rate of E. coli. When inactivated by MWUV with an intensity of 1.2 mW/cm2 and a dose of 16 mJ/cm2, the maximum photoreactivation rate and reactivation rate constant Kmax of E. coli were 0.63 % and 0.11 % h-1 respectively. Compared with the photoreactivation, the dark repair of E. coli was insignificant. The full-scale application of the MDEL equipment was conducted in two WWTPs (10,000 m3/d and 15,000 m3/d). Generally 2-3 log inactivation rates of fecal coliforms in secondary effluent were achieved within 5-6 s contact time, and the disinfected effluent met the emission standard (1000 CFU/L). This study successfully applied MDEL for disinfection in WWTPs for the first time and demonstrated that MDEL has broad application prospects.


Subject(s)
Disinfection , Wastewater , Escherichia coli , Ultraviolet Rays , Microwaves
5.
BMC Geriatr ; 22(1): 983, 2022 12 20.
Article in English | MEDLINE | ID: mdl-36539697

ABSTRACT

BACKGROUND: To investigate the association between low-carbohydrate-diet (LCD) score and cognitive performance based on a nationally representative sample aged ≥ 60 years from National Health and Nutrition Examination Survey (NHANES) database. METHODS: This cross-sectional study included 2,537 eligible older adults from the NHANES database 2011-2014. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) word learning subtest, Animal Fluency Test (AFT), and Digit Symbol Substitution Test (DSST) were used to assess the cognitive performance. All participants were categorized into the low and normal cognitive performance groups. The univariate and multivariate logistic regression analyses were utilized to evaluate the association of LCD score with cognitive performance. Stratified analyses based on age, body mass index (BMI), gender, marital status, education level was conducted. RESULTS: After adjusting age, education level, marital status, household income, history of diabetes, history of hypertension, history of congestive heart failure, history of coronary heart disease, history of heart disease, history of stroke, magnesium and the using of psychotropic medication, LCD score was correlated with the CERAD word learning subtest. The associations between LCD score and AFT, DSST were not statistically significant. Moreover, LCD score was also related to cognitive performance among individuals who were aged < 65 years or BMI 25-30 kg/m2 or was married/separated, or had an education level of high school or above. CONCLUSION: The adherences to LCD might be associated with the risk of cognitive performance among older adults. Further large-scale cohort studies are needed to test the causal relationship of LCD and cognitive performance.


Subject(s)
Alzheimer Disease , Cognition , Humans , Nutrition Surveys , Cross-Sectional Studies , Diet , Carbohydrates
6.
Dis Markers ; 2022: 9701047, 2022.
Article in English | MEDLINE | ID: mdl-36046374

ABSTRACT

Objective: The objective of this study is to explore the effects of microRNA-33a-5p (miR-33a-5p)-ras-related protein Rap-2a (RAP2A) on biological functions of gastric cancer (GC) and to find the potential functional mechanism. Methods: We measured the miR-33a-5p expression in 30 GC tissues and cellular level and 30 adjacent normal tissues as control. Besides, the expression of miR-33a-5p was checked at cell level as well. To screen the possible targets of miR-33a-5p, prediction software was used and gene RAP2A attracted our attention. Through a series of experiments including real-time polymerase chain reaction (qRT-PCR), luciferase assay, and western blotting (WB), we verified RAP2A as a potential target of miR-33a-5p. The impacts of miR-33a-5p and RAP2A on biological functions of GC cell lines (BGC-823 and MGC-803) were analyzed by subsequent experiments. Cell invasion was tested by invasion assays. Cell proliferation was measured by cell counting kit-8 (CCK-8) assay. Cell clone was measured by clone formation assays. Finally, the expression of RAP2A protein was analyzed by WB assay. Results: We found miR-33a-5p was expressed lowly in GC tissues and cells. Overexpression of miR-33a-5p in BGC-823 and MGC-803 cells greatly inhibited the cell invasion and colony number. Furthermore, compared to sh-control (shControl), RAP2A knockdown (sh-RAP2A/shRAP2A) raised the sensitivity of GC cells to 5-FU significantly, characterized as reducing cell apoptosis. Conclusions: The expression of miR-33a-5p was lower in GC cell lines and tissues obviously, indicating that miR-33a-5p served as the antitumor gene in GC. The expression of RAP2A regulated negatively the sensitivity of GC cells to 5-FU. According to our in vitro experiments, miR-33a-5p/RAP2A was likely to become a new therapeutic target for GC.


Subject(s)
MicroRNAs , Stomach Neoplasms , Cell Line, Tumor , Cell Proliferation/genetics , Fluorouracil , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , MicroRNAs/metabolism , Stomach Neoplasms/pathology , rap GTP-Binding Proteins/genetics , rap GTP-Binding Proteins/metabolism
7.
Appl Opt ; 60(13): 4004-4012, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33983340

ABSTRACT

The reconstruction of the size, position, optical properties, and structure of the object in scattering media was realized with a chaotic fiber laser. The light from the chaotic fiber laser was split into two parts. One part was used as the detection signal to detect the object, and the other was used as the reference signal; then, the two signals were cross correlated. The attenuation of light in scattering media was attributed to scattering and absorption. The theoretical model of the peak value of cross correlation of the chaotic signals as projection data were established by the attenuation law, and the filtered back-projection algorithms were used to realize the image reconstruction. The mean squared error, the normalized mean squared error, the peak signal-to-noise ratio, and the structural similarity index of the reconstructed image were analyzed. The results show that the high resolution of the reconstructed image benefits from the high signal-to-noise ratio with the chaotic fiber laser based on a delta-like cross-correlation function.

8.
BMC Public Health ; 18(1): 1267, 2018 Nov 19.
Article in English | MEDLINE | ID: mdl-30453912

ABSTRACT

BACKGROUND: Anemia is one of the most common diseases of childhood and is a health problem globally, particularly in developing counties and in children less than 2 years of age. Anemia during childhood has short- and long-term effects on health. However, few studies have investigated the prevalence of anemia among children in Huaihua. Therefore, this study analyzed the prevalence and risk factors of anemia among children 6 to 23 months of age in Huaihua. METHODS: This cross-sectional study was conducted at a maternal and child health care hospital in Huaihua, from September to November 2017. The study population recruited using a multistage sampling technique. A structured questionnaire was used to collect data on the characteristics of the children and members of their families. Hemoglobin (Hb) levels were measured by using a microchemical reaction method. Logistic regression analysis was used to identify associated factors and odds ratio with 95% CI was computed to assess the strength of association. RESULTS: In total, 4450 children were included in this study. The prevalence of anemia was 29.73%. In multivariate logistic regression analysis, the results show that mother and father of Miao ethnicity (OR = 1.23 and 1.31), diarrhea in the previous 2 weeks (OR = 1.35), breastfeeding in the prior 24 h (OR = 1.50), and caregivers able to identify the optimum timing of complementary feeding (OR = 1.15) had positive correlations with anemia. However, children aged 18 to 23 months (OR = 0.55), father of Dong ethnicity (OR = 0.82), addition of milk powder once or twice (OR = 0.71), addition of infant formula once or twice, three times, and four or more times in the previous 24 h (OR = 0.72, 0.70, and 0.75), and addition of a nutrient sachet four or more times in the prior week (OR = 0.70) were negatively associated with anemia. CONCLUSIONS: The prevalence of anemia among children 6 to 23 months of age in Huaihua was higher than that in more developed regions of China. The feeding practice of caregivers was associated with anemia. nutrition improvement projects are needed to reduce the burden of anemia among children in Huaihua.


Subject(s)
Anemia/epidemiology , China/epidemiology , Cross-Sectional Studies , Feeding Behavior , Female , Humans , Infant , Male , Prevalence , Risk Factors , Surveys and Questionnaires
9.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-698699

ABSTRACT

BACKGROUND: Deep venous thrombosis and blood loss are common complications after total hip arthroplasty in elderly patients. Thus, it needs to pick valid treatments to reduce the harm in the clinical treatment. OBJECTIVE: To compare and observe the effects of rivaroxaban and low molecular heparin on preventing deep venous thrombosis and blood loss after total hip arthroplasty in elderly patients. METHODS: 196 cases in Department of Orthopedics, General Hospital of Shuicheng Mining Group of Guizhou Province treated by unilateral total hip arthroplasty were enrolled between January 2015 and January 2017. They were randomly divided into observation group (98 cases) and control group (98 cases). The observation group was treated with oral rivaroxaban 6 hours after surgery for 2 consecutive weeks. The control group was subcutaneously injected with low molecular heparin injection 6 hours after surgery for 5 consecutive weeks. The coagulation index was measured by automatic coagulation analyzer at preoperative, 1 day, 1 and 2 weeks after surgery. Deep venous thrombosis was evaluated in the two groups. The caliber sizes of superficial femoral vein and popliteal vein were measured by color Doppler ultrasound before surgery, 1, 2, 3 and 4 weeks after surgery. Blood loss was recorded in the two groups. RESULTS AND CONCLUSION: (1) The difference in serum D-dimer levels was statistically significant 1 and 2 weeks after surgery in both groups (P < 0.05). Serum D-dimer levels were lower in the observation group than in the control group. (2) The incidence of deep venous thrombosis was lower in the observation group than in the control group (P < 0.05). (3) The caliber size of superficial femoral vein and popliteal vein was significantly different 1, 2, 3 and 4 weeks after surgery in both groups (P < 0.05). The caliber size of superficial femoral vein and popliteal vein was larger in the observation group than in the control group. (4) Hidden blood loss and total blood loss were significantly different between the two groups (P < 0.05). The hidden blood loss and total blood loss were higher in the observation group than in the control group. (5) Results suggest that rivaroxaban has a positive meaning for prevention of deep venous thrombosis after total hip arthroplasty in elderly patients. However, hidden blood loss is worthy of attention.

10.
Cardiovasc Drugs Ther ; 25(3): 203-14, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21503625

ABSTRACT

OBJECTIVE: The effect of granulocyte colony-stimulating factor (G-CSF) on post-infarct ventricular remodeling remains controversial. We hypothesized that the timing of G-CSF administration after myocardial ischemia plays an important role in determining its efficacy. METHODS: Rat myocardial ischemia was induced by 60 min coronary ligation and reperfusion. Surviving animals received G-CSF after 1 h (E-G) or 24 h (D-G) of reperfusion randomly at 100 µg/kg/d for five consecutive days. 7 days or 3 months post-ischemia, rat hearts were quickly removed for ex vivo electrophysiological measurements or histological analysis (collagen disposition and angiogenesis) and metalloproteinase-2 and -9 activity assays (gelatin zymography). Left ventricular (LV) invasive hemodynamic analysis was performed in 3-month recovery animals before sacrifice. RESULTS: At 3 months post ischemia, LV mechanical remodeling was further impaired with early G-CSF administration (0.65 ± 0.17%, 13.21 ± 7.36 mmHg, -4,684 ± 1,560 mmHg/s) compared with the control group (0.28 ± 0.12%, 6.45 ± 3.43 mmHg, -6,267 ± 1,111 mmHg/s) and D-G group (0.34 ± 0.12%, 7.90 ± 5.33 mmHg, -6,227 ± 1,075 mmHg/s) as shown by increased expansion index (P < 0.01), deterioration of myocardial function with increased LVDP (P < 0.05), and decreased -dP/dt (max) (P < 0.05). By contrast, there was a significant increase in electrical properties including monophasic action potential (MAP) 90 dispersion (12.58 ± 4.46 vs. 30.56 ± 6.17 ms at 7 days; 18.54 ± 4.31 vs. 34.78 ± 5.24 ms at 3 months; P < 0.05 for both) and inducibility of ventricular arrhythmias (4.78 ± 1.19 vs. 11.58 ± 2.76 ms at 3 months; P < 0.05) with early G-CSF treatment compared with the control group. CONCLUSIONS: Both early and delayed administrations of G-CSF can improve electrophysiological properties after myocardial ischemia, but have no beneficial effects on LV mechanical remodeling.


Subject(s)
Granulocyte Colony-Stimulating Factor/pharmacology , Myocardial Ischemia/drug therapy , Ventricular Function, Left/drug effects , Ventricular Remodeling/drug effects , Animals , Drug Administration Schedule , Electrophysiological Phenomena/drug effects , Granulocyte Colony-Stimulating Factor/administration & dosage , Male , Myocardial Ischemia/physiopathology , Myocardial Reperfusion Injury/drug therapy , Myocardial Reperfusion Injury/physiopathology , Rats , Rats, Wistar , Time Factors , Ventricular Fibrillation/drug therapy , Ventricular Fibrillation/etiology
11.
Coron Artery Dis ; 19(5): 363-70, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18607174

ABSTRACT

OBJECTIVE: Platelet activation and subsequent release of granules containing a variety of growth factors, at the site of injury, is crucial for the wound healing process. We postulated that a platelet-mediated paracrine effect may accelerate the healing process after myocardial infarction. METHODS: Allogenic platelet-rich and platelet-poor plasma (PRP and PPP) were collected from 15 healthy male Wistar rats. After thrombin activation, the level of vascular endothelial growth factor (VEGF) in PRP and PPP was measured by enzyme-linked immunosorbent assay. A rat model of myocardial infarction was induced by permanent ligation of the left anterior descending artery, and thrombin-activated PRP and PPP, respectively, were injected into the ischemic region. Seven days and 28 days after operation, surviving rats were killed. Ex-vivo left ventricular pressure-volume relationship was performed to evaluate passive diastolic function. Collagen analysis was performed by picrosirius red staining plus polarized microscopy. Angiogenesis and arteriogenesis were evaluated by immunofluorescent staining. RESULTS: After thrombin activation, VEGF level in PRP was significantly higher than that in PPP (187.5+/-45.5 vs. 30.1+/-7.8 pg/ml, P<0.01). Injection of thrombin-activated PRP into the infarcted area resulted in improvement of ventricular remodeling and accelerated healing, as demonstrated by limitation of ventricular expansion, attenuation of myocardial hypertrophy in the noninfarct region, facilitation of angiogenesis and arteriogenesis in the infarct. CONCLUSION: Injection of thrombin-activated PRP could modulate favorably the postinfarction remodeling process. Platelet-released VEGF may participate in this protective effect.


Subject(s)
Angiogenesis Inducing Agents/pharmacology , Myocardial Infarction/physiopathology , Platelet-Derived Growth Factor/pharmacology , Platelet-Rich Plasma/drug effects , Vascular Endothelial Growth Factor A/metabolism , Ventricular Remodeling/drug effects , Angiogenesis Inducing Agents/metabolism , Animals , Heart/drug effects , Heart/physiopathology , Male , Platelet Activation/drug effects , Platelet-Derived Growth Factor/metabolism , Platelet-Rich Plasma/metabolism , Rats , Rats, Wistar , Thrombin/metabolism , Thrombin/pharmacology , Ventricular Function/drug effects , Wound Healing/drug effects , Wound Healing/physiology
12.
Med Hypotheses ; 70(1): 112-6, 2008.
Article in English | MEDLINE | ID: mdl-17560046

ABSTRACT

Heart failure (HF) is a major and growing public health problem in the world. About 50% of deaths in HF occur suddenly due to malignant arrhythmia. Therefore, exploring the further mechanisms of chronic HF and finding new therapy targets are essential for the progression of HF treatment. Recently, some published papers suggested that myocardial neural remodeling and abnormal excitation-contraction (EC) coupling might partly contribute to the development of HF and sudden cardiac death. Even though a few studies have demonstrated that the sympathetic nerve system (SNS) may have significant impact on the functional states of myocardial EC coupling through the beta-adrenergic signaling pathway, so far, it still remains unknown that whether neural remodeling affects the EC coupling. Studies from Marks' group demonstrated that 70% of cardiac ryanodine receptors (RyR2), which located on the sarcoplasmic reculum (SR) controlling intracellular Ca(2+) release and muscle contraction in the heart, from failing hearts were abnormal and only 15% exhibited the most severe defects. In addition, Litwin et al. observed that temporal and spatial heterogeneities in local Ca(2+) release events in a rabbit model of HF after myocardial infarction. Because some studies have demonstrated that chronic SNS hyperactivity in HF led to protein kinase A (PKA) hyperphosphorylation of RyR2 in the heart, and the myocardial sympathetic nerve distribution become heterogeneous in the setting of HF. Thus, it is reasonable for us to propose the hypothesis that neural remodeling may partly account for the abnormality of EC coupling in HF.


Subject(s)
Heart Conduction System/physiopathology , Heart Failure/physiopathology , Models, Neurological , Myocardial Contraction/physiology , Calcium/physiology , Humans
14.
Scand Cardiovasc J ; 41(3): 149-54, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17487763

ABSTRACT

OBJECTIVES: To investigate the association between inflammatory mediators, matrix degrading enzymes and acute coronary syndrome (ACS) and the impact of early reperfusion therapy on circulating biomarkers. DESIGN: Peripheral serum levels of interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and matrix metalloproteinase-9 (MMP-9) were determined in 134 patients with ACS. These biomarkers were serially monitored in ten patients with intravenous thrombolytic therapy (IVT). RESULTS: Serum levels of IL-6, hs-CRP and MMP-9 were higher in unstable angina (UA) and myocardial infarction (MI) groups than in control or SA group (p<0.05). Peripheral IL-6 level in patients with MI was greater after percutaneous coronary intervention (PCI) (p<0.01) or IVT (p<0.05). Serial concentration determination revealed marked elevation of serum IL-6 and MMP-9 levels, both reaching peak values (like creatine kinase-MB). CONCLUSIONS: Elevated levels of IL-6, hs-CRP and MMP-9 provide a link between inflammation, matrix degradation and the development and progression of ACS. IL-6 and MMP-9 appear to be released mainly from vulnerable plaque or necrotic myocardium during the acute phase of MI.


Subject(s)
Interleukin-6/blood , Matrix Metalloproteinase 9/blood , Myocardial Ischemia/metabolism , Myocardium/metabolism , Acute Disease , Adult , Aged , Aged, 80 and over , Angioplasty, Balloon, Coronary , Biomarkers/blood , C-Reactive Protein/metabolism , Creatine Kinase, MB Form/blood , Female , Fibrinolytic Agents/therapeutic use , Humans , Male , Middle Aged , Myocardial Ischemia/enzymology , Myocardial Ischemia/therapy , Myocardium/enzymology , Research Design , Time Factors , Treatment Outcome
15.
Med Hypotheses ; 68(5): 952-6, 2007.
Article in English | MEDLINE | ID: mdl-17126495

ABSTRACT

Hypertension-induced target organ damage (TOD), is one of the leading causes of morbidity and mortality. Reactive oxygen species (ROS) play an important role in the pathogenesis and development of hypertension. It has been suggested that hypertension-induced TOD is related to the level of oxidative stress, but is in part independent of the level of blood pressure. Therefore, in addition to anti-hypertensive drug therapy, novel strategies against ROS, will provide additional benefits to patient with hypertension. Vitamin E has long been supplemented as an effective antioxidant. However, the potential hazardous effects of vitamin E supplementation as antioxidant revealed by recent studies make its clinical and routine use prudent. Therefore, novel approaches capable of enhancing endogenous system to defend against ROS are required. Here, we propose that enhancement of intrinsic defenses against ROS by supra-nutritional level of selenium is more safe and effective than antioxidant supplementation in reducing hypertensive target organ damage, owing to its role in activating and constitution of native vital proteins and/or enzymes against oxidative stress, and the fact that scarcity of selenium can not be supplemented by normal food, and potentially extra benefits by supra-normal intake.


Subject(s)
Antioxidants/therapeutic use , Dietary Supplements , Hypertension/drug therapy , Models, Biological , Oxidative Stress , Selenium/therapeutic use , Humans , Reactive Oxygen Species/metabolism , Selenium/adverse effects , Treatment Outcome
16.
Clin Exp Pharmacol Physiol ; 33(11): 1029-34, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17042910

ABSTRACT

1. Dexamethasone (Dex)-induced hypertension is characterized by endothelial dysfunction associated with nitric oxide (NO) deficiency and increased superoxide (O2-) production. Atorvastatin (Ato) possesses pleiotropic properties that have been reported to improve endothelial function through increased availability of NO and reduced O2- production in various forms of hypertension. In the present study, we investigated whether 50 mg/kg per day, p.o., Ato could prevent endothelial NO synthase (eNOS) downregulation and the increase in O2- in Sprague-Dawley (SD) rats, thereby reducing blood pressure. 2. Male SD rats (n = 30) were treated with Ato (50 mg/kg per day in drinking water) or tap water for 15 days. Dexamethasone (10 microg/kg per day, s.c.) or saline was started after 4 days in Ato-treated and non-treated rats and continued for 11-13 days. Systolic blood pressure (SBP) was measured on alternate days using the tail-cuff method. Endothelial function was assessed by acetylcholine-induced vasorelaxation and phenylephrine-induced vasoconstriction in aortic segments. Vascular eNOS mRNA was assessed by semi-quantitative reverse transcription-polymerase chain reaction. 3. In rats treated with Dex alone, SBP was increased from 109 +/- 2 to 133 +/- 2 mmHg on Days 4 and Day 14, respectively (P < 0.001). In the Ato + Dex group, SBP was increased from 113 +/- 2 to 119 +/- 2 mmHg on Days 4 to 14, respectively (P < 0.001), but was significantly lower than SBP in the group treated with Dex alone (P < 0.05). Endothelial-dependent relaxation and eNOS mRNA expression were greater in the Dex + Ato group than in the Dex only group (P < 0.05 and P < 0.0001, respectively). Aortic superoxide production was lower in the Dex + Ato group compared with the group treated with Dex alone (P < 0.0001). 4. Treatment with Ato improved endothelial function, reduced superoxide production and reduced SBP in Dex-treated SD rats.


Subject(s)
Antioxidants/therapeutic use , Dexamethasone/toxicity , Heptanoic Acids/therapeutic use , Hypertension/chemically induced , Hypertension/drug therapy , Pyrroles/therapeutic use , Animals , Aorta/enzymology , Atorvastatin , Gene Expression Regulation, Enzymologic , Male , Nitric Oxide/blood , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Vasoconstriction/drug effects , Vasodilation/drug effects
17.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue ; 18(8): 491-3, 2006 Aug.
Article in Chinese | MEDLINE | ID: mdl-16887065

ABSTRACT

OBJECTIVE: To evaluate the effect of angiotensin II (Ang II) and its receptor antagonist on action potential duration and L-type calcium current density of cardiac myocytes. METHODS: Single myocyte of the ventricle in guinea was isolated. Action potentials were recorded using a conventional glass microelectrode filled with 3 mol/L KCl solution. Membrane patch clamp whole cell recording technique was used to investigate L-type calcium current maximum in holding potential of -40 mV, length of time 200 ms, command potential 0 mV. RESULTS: Ang II induced arrhythmia of multiple electrophysiologic mechanisms. Action potential amplitude, 90% of action potential duration (APD90), and resting membrane potential (RMP) were significantly decreased or shortened after being perfused Ang II for 1 minute compared with controls. 30% of action potential duration (APD30), 50% of action potential duration (APD50), effective refractory period (ERP) were also shortened significantly after perfused Ang II for 3 minutes compared with controls. Ang II increased the L-type calcium maximum current density after a perfusion of 5 minutes, but losartan perfusion for 1 minute decreased the L-type calcium maximum current density, and it further decreased after perfusion for 3 minutes. However, the current voltage relationship curve was unchanged. CONCLUSION: Ang II could decrease amplitude of monophasic action potential, rest membrane potential, shorten duration of monophasic action potential and effective refractory period, increase maximum current density of voltage dependent L-type calcium, and possess the effect of inducing arrhythmia. Losartan decreased maximum current density of voltage dependent L-type calcium.


Subject(s)
Angiotensin II/pharmacology , Calcium Channels, L-Type/drug effects , Losartan/pharmacology , Myocytes, Cardiac/physiology , Action Potentials/drug effects , Animals , Calcium Channels, L-Type/physiology , Cells, Cultured , Female , Guinea Pigs , Male , Myocytes, Cardiac/drug effects , Patch-Clamp Techniques
18.
Clin Exp Hypertens ; 28(5): 499-509, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16820346

ABSTRACT

To assess the antioxidant effects of atorvastatin (atorva) on dexamethasone (dex)-induced hypertension, 60 male Sprague-Dawley rats were treated with atorva 30 mg/kg/day or tap water for 15 days. Dex increased systolic blood pressure (SBP) from 109 +/- 1.8 to 135 +/- 0.6 mmHg and plasma superoxide (5711 +/- 284.9 saline, 7931 +/- 392.8 U/ml dex, P < 0.001). In this prevention study, SBP in the atorva + dex group was increased from 115 +/- 0.4 to 124 +/- 1.5 mmHg, but this was significantly lower than in the dex-only group (P' < 0.05). Atorva reversed dex-induced hypertension (129 +/- 0.6 mmHg, vs. 135 +/- 0.6 mmHg P' < 0.05) and decreased plasma superoxide (7931 +/- 392.8 dex, 1187 +/- 441.2 atorva + dex, P < 0.0001). Plasma nitrate/nitrite (NOx) was decreased in dex-treated rats compared to saline-treated rats (11.2 +/- 1.08 microm, 15.3 +/- 1.17 microm, respectively, P < 0.05). Atorva affected neither plasma NOx nor thymus weight. Thus, atorvastatin prevented and reversed dexamethasone-induced hypertension in the rat.


Subject(s)
Dexamethasone/adverse effects , Glucocorticoids/adverse effects , Heptanoic Acids/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hypertension/chemically induced , Hypertension/prevention & control , Pyrroles/pharmacology , Analysis of Variance , Animals , Atorvastatin , Biomarkers/blood , Blood Pressure/drug effects , Body Weight/drug effects , Disease Models, Animal , Down-Regulation/drug effects , Hypertension/blood , Hypertension/drug therapy , Male , Nitrates/blood , Nitric Oxide Synthase Type III/drug effects , Nitrites/blood , Organ Size/drug effects , Rats , Rats, Sprague-Dawley , Superoxides/blood , Thymus Gland/anatomy & histology
19.
Zhonghua Nei Ke Za Zhi ; 45(1): 21-4, 2006 Jan.
Article in Chinese | MEDLINE | ID: mdl-16624082

ABSTRACT

OBJECTIVE: To assess whether Xuezhikang was effective in the secondary prevention of coronary heart disease (CHD) for patients with different length of myocardial infarction (MI) history. METHODS: 2135 patients with MI history of 28 days to 3 months and 2735 patients with MI history of 3 months to 60 months were recruited separately to receive treatment with Xuezhikang capsule or placebo. The primary end-points were nonfatal myocardial infarction and death from CHD. RESULTS: The occurrence of coronary events were found to be not statistically significantly different for the two groups of patients. For patients with MI history of 28 days to 3 months, Xuezhikang significantly reduced the risk of CHD events by 56.7% (P < 0.0001) and resulted in a 48.6% (P = 0.0002) risk reduction in all-cause mortality as compared with placebo. For patients with MI history of 3 months to 60 months, Xuezhikang significantly decreased the risk of CHD events by 35.3% (P = 0.0008) and led to a 20.0% (P = 0.1181) risk reduction in the all-cause mortality as compared with placebo. Adverse effects and abnormal laboratory parameters did not differ significantly in the two groups of patients. CONCLUSIONS: Xuezhikang is more effective for patients with MI history of 28 days to 3 months as compared with patients with MI history of 3 months to 60 months. Patients with MI history should be treated with Xuezhikang early in order to achieve better prevention of CHD.


Subject(s)
Coronary Disease/prevention & control , Drugs, Chinese Herbal/therapeutic use , Myocardial Infarction/drug therapy , Phytotherapy , China , Double-Blind Method , Humans , Myocardial Infarction/mortality
20.
Clin Exp Pharmacol Physiol ; 33(4): 369-73, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16620303

ABSTRACT

1. Adrenocorticotropic hormone (ACTH)-induced hypertension is associated with nitric oxide (NO) deficiency and increased oxidative stress. Atorvastatin (Ato), an HMG-Co-enzyme-A reductase inhibitor has been reported to enhance availability of NO. The aim of the study was to assess whether pretreatment with Ato would prevent the development of ACTH-induced hypertension and whether established ACTH-induced hypertension could be reversed with subsequent administration of Ato in rats. 2. Male Sprague-Dawley rats (n = 60) were treated with Ato (30 mg/kg per day in drinking water) or tap water for 15 days. ACTH (0.2 mg/kg per day s.c) or saline was started 4 days after Ato treatment or non-treated rats and continued for 11-13 days (prevention study). In the reversal study, Ato was given on day 8 of ACTH/Saline treatment for 5 days. Systolic blood pressure (SBP) was measured on alternate days using the tail cuff method. 3. Adrenocorticotropic hormone treatment increased SBP (110 +/- 2-136 +/- 2 mmHg, P < 0.001) and aortic superoxide production (P < 0.001). Ato alone did not alter SBP, but Ato pretreatment prevented ACTH-induced hypertension compared with that in rats treated with ACTH alone (118 +/- 2 and 136 +/- 2 mmHg, respectively, P cent < 0.01). Ato partially reversed ACTH-induced hypertension (124 +/- 3 and 136 +/- 2 mmHg, respectively, P cent < 0.05). Plasma nitrate/nitrite (NOx) was decreased in ACTH-treated rats compared with saline treated rats (6.6 +/- 0.4 saline and 4.5 +/- 0.5 micromol/L ACTH, P < 0.001). Atorvastatin affected neither plasma NOx nor aortic superoxide production. 4. Atorvastatin prevented and partially reversed ACTH-induced hypertension in the rat.


Subject(s)
Adrenocorticotropic Hormone , Heptanoic Acids/therapeutic use , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hypertension/prevention & control , Pyrroles/therapeutic use , Animals , Atorvastatin , Blood Pressure/drug effects , Body Weight/drug effects , Heptanoic Acids/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hypertension/chemically induced , Hypertension/drug therapy , Male , Nitric Oxide/blood , Pyrroles/pharmacology , Rats , Rats, Sprague-Dawley , Superoxides/metabolism
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