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ABSTRACT: The purpose of this paper was to research the potential of a dynamic cell model in drug screening by studying the influence of microvascular wall shear stress on the drug absorption of endothelial cells compared to that in the static state. The cells were grown and seeded on gelatin-coated glass slides and were pretreated with extracts of Salviae miltiorrhizae (200 μg/ml) for 1 h. Then oxidative stress damage was produced by H2O2 (300 μmol/l) for 0.5 h under the 1.5 dyn/cm2 shear stress incorporated in a parallel plate flow chamber. Morphological analysis was conducted with an inverted microscope and image analysis software, and high performance liquid chromatography-mass spectrometry was used for the detection of active compounds. We compared the drug absorption in the dynamic group with that in the static group. In the dynamic model, five compounds and two new metabolite peaks were detected. However, in the static model, four compounds were absorbed by cells, and one metabolite peak was found. This study indicated that there were some effects on the absorption and metabolism of drugs under the microvascular shear stress compared to that under stasis. We infer that shear stress in the microcirculation situation in vivo played a role in causing the differences between drug screening in vitro and in vivo.
Biorheology 01/2013; 50(1):33-43. · 1.93 Impact Factor
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ABSTRACT: In acute lung injury (ALI), angiotensin II (Ang II) plays a vital role in the stimulation of pulmonary permeability edema formation through the angiotensin type 1 (AT1) receptor. The effect of Ang II on alveolar fluid clearance (AFC) in ALI remains unknown.
Sprague Dawley rats were anesthetized and intratracheally injected with 1 mg⁄kg lipopolysaccharide (LPS), while control rats received saline. The AT1 receptor antagonist ZD7155 was injected intraperitoneally (10 mg⁄kg) 30 min before LPS administration. The lungs were isolated for AFC measurement, and alpha-epithelial sodium channel (ENaC) messenger RNA and protein expression were detected by reverse-transcription polymerase chain reaction and Western blot.
LPS-induced ALI caused an increase in Ang II levels in plasma and lung tissue but a decrease in AFC. The time course of Ang II levels paralleled that of AFC. Pretreatment with ZD7155 prevented ALI-induced reduction of AFC. ZD7155 also reversed the ALI-induced reduction of beta-ENaC and gamma-ENaC levels, and further decreased alpha-ENaC levels.
These findings suggest that endogenous Ang II inhibits AFC and dysregulates ENaC expression via AT1 receptors, which contribute to alveolar filling and pulmonary edema in LPS-induced ALI.
Canadian respiratory journal: journal of the Canadian Thoracic Society 09/2012; 19(5):311-8. · 1.56 Impact Factor
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ABSTRACT: Miliary tuberculosis (TB) is an uncommon cause of acute respiratory distress syndrome (ARDS) with a high mortality. The aim of the present study was to evaluate the clinical characteristics, predictors and outcome of patients with ARDS caused by miliary TB.
A retrospective study was conducted among patients with a diagnosis of ARDS with miliary TB in four hospitals from 2006 to 2010. Medical records and laboratory examinations of these patients were taken during the first 24 h of admission.
Eighty-five patients with miliary TB developed ARDS, 45 of whom survived (52.9%). The median age was 36.6 ± 12.5 years with 38 males (44.7%). Diabetes mellitus (DM) was the most common underlying disease (18.8%).ICU mortality was 47.1%. The time from admission to anti-tuberculosis therapy was 4.5 ± 2.0 days. Mean duration of mechanical ventilation was 8.5 ± 3.0 days in all patients. Duration of time to diagnosis, time from diagnosis to mechanical ventilation, and time to anti-tuberculosis therapy were significantly shorter in survivors than those in non-survivors. Diabetes mellitus (OR 5.431, 95%CI 1.471-20.049; P = 0.005), ALT (70-100U/L, OR 10.029, 95%CI 2.764-36.389; P = 0.001), AST (>94U/L,OR 8.034, 95%CI 2.200-29.341; P = 0.002), D-dimer (>1.6mg/L, OR 3.167, 95%CI 0.896-11.187; P = 0.042), hemoglobin (<90g/L, OR 14.824, 95%CI 3.713-59.179; P = 0.001), albumin (<25g/L, OR 15.896, 95%CI 3.975-63.566; P = 0.001) were independent predictors of ARDS development in the setting of miliary TB.
Accurate diagnosis, early initiation of anti-tuberculosis therapy and mechanical ventilation are important for the outcome of patients with ARDS caused by miliary TB. DM, ALT, AST, D-dimer, hemoglobin, and albumin are independent predictors of ARDS development in patients with miliary TB.
BMC Infectious Diseases 05/2012; 12:121. · 3.12 Impact Factor
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ABSTRACT: AbstractNickel nanoparticles supported on boehmite were prepared by a modified electroless nickel-plating method and a direct reduction
method. We mainly studied the catalyst synthesized by the direct reduction method. The as-prepared nickel catalyst was characterized
by X-ray diffraction and high-resolution transmission electron microscopy. The catalytic behavior in selective hydrogenation
of p-nitrophenol to p-aminophenol and p-chloronitrobenzene to p-chloroaniline was studied and compared with Ni–B/γ-Al2O3 catalyst prepared by incipient-wetness impregnation and Ni–B/Al2O3·xH2O catalyst synthesized by a coprecipitation method. The Ni–B/boehmite catalysts were found to be more reactive than the Ni–B/γ-Al2O3 and Ni–B/Al2O3·xH2O catalysts. The superior activity of the Ni–B/boehmite catalyst was attributed to the small Ni–B particles and large amount
of structural water, which enhanced the hydrophilicity of the catalyst.
Graphical AbstractThe Ni–B/boehmite sample was prepared by a direct reduction method. Compared with boehmite (a), the black spheres in b represent
Ni–B cluster, the Ni–B cluster is about 20nm in diameter.
KeywordsNi–B-Boehmite-
p-Nitrophenol-
p-Chloronitrobenzene-Hydrogenation
Catalysis Letters 04/2012; 137(3):261-266. · 2.24 Impact Factor
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ABSTRACT: Asthma is a chronic inflammatory disease characterized by reversible bronchial constriction, pulmonary inflammation and airway remodeling. Current standard therapies for asthma provide symptomatic control, but fail to target the underlying disease pathology. Furthermore, no therapeutic agent is effective in preventing airway remodeling. A substantial amount of evidence suggests that statins have anti-inflammatory properties and immunomodulatory activity. In this study, we investigated the effect of rosuvastatin on airway inflammation and its inhibitory mechanism in mucus hypersecretion in a murine model of chronic asthma.
BALB/c mice were sensitized and challenged by ovalbumin to induce asthma. The recruitment of inflammatory cells into bronchoalveolar lavage fluid (BALF) and the lung tissues were measured by Diff-Quik staining and hematoxylin and eosin (H&E) staining. ELISA was used for measuring the levels of IL-4, IL-5, IL-13 and TNF-α in BALF. Periodic acid-Schiff (PAS) staining was used for mucus secretion. Gamma-aminobutyric acid type A receptor (GABAAR) β2 expression was measured by means of immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.
Rosuvastatin reduced the number of total inflammatory cells, lymphocytes, macrophages, neutrophils, and eosinophils recruited into BALF, the levels of IL-4, IL-5, IL-13 and TNF-α in BALF, along with the histological mucus index (HMI) and GABAAR β2 expression. Changes occurred in a dose-dependent manner.
Based on its ability to reduce the inflammatory response and mucus hypersecretion by regulating GABAAR activity in a murine model of chronic asthma, rosuvastatin may be a useful therapeutic agent for treatment of asthma.
Chinese medical journal 04/2012; 125(8):1457-64. · 0.86 Impact Factor
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ABSTRACT: Angiotensin II (Ang II) has been demonstrated as a pro-inflammatory effect in acute lung injury, but studies of the effect of Ang II on the formation of pulmonary edema and alveolar filling remains unclear. Therefore, in this study the regulation of alveolar fluid clearance (AFC) and the expression of epithelial sodium channel (ENaC) by exogenous Ang II was verified. SD rats were anesthetized and were given Ang II with increasing doses (1, 10 and 100 μg/kg per min) via osmotic minipumps, whereas control rats received only saline vehicle. AT1 receptor antagonist ZD7155 (10 mg/kg) and inhibitor of cAMP degeneration rolipram (1 mg/kg) were injected intraperitoneally 30 min before administration of Ang II. The lungs were isolated for measurement of alveolar fluid clearance. The mRNA and protein expression of ENaC were detected by RT-PCR and Western blot. Exposure to higher doses of Ang II reduced AFC in a dose-dependent manner and resulted in a non-coordinate regulation of α-ENaC vs. the regulation of β- and γ-ENaC, however Ang II type 1 (AT1) receptor antagonist ZD7155 prevented the Ang II-induced inhibition of fluid clearance and dysregulation of ENaC expression. In addition, exposure to inhibitor of cAMP degradation rolipram blunted the Ang II-induced inhibition of fluid clearance. These results indicate that through activation of AT(1) receptor, exogenous Ang II promotes pulmonary edema and alveolar filling by inhibition of alveolar fluid clearance via downregulation of cAMP level and dysregulation of ENaC expression.
Respiratory Physiology & Neurobiology 11/2011; 181(1):53-61. · 2.24 Impact Factor
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ABSTRACT: To research the effect of exogenous angiotensin II (AngII) on alveolar fluid clearance (AFC) and alveolar epithelial sodium channel (ENaC) expression in rats.
Fifteen healthy Sprague-Dawley (SD) rats were randomly divided into control group, AngII group and AngII type 1 (AT1) receptor blocker ZD7155 pretreatment group, with 5 rats in each group. Exogenous AngII 10 μg× kg(-1)×min(-1)was administered by micro pump via catheter in left jugular vein in AngII group and ZD7155 pretreatment group, whereas control group rats received only normal saline. ZD 7155 10 mg/kg was injected intraperitoneal 30 minutes before administration of exogenous AngII in ZD7155 pretreatment group. The pathological changes in lung were observed after 6 hours. AFC was estimated by Evans-blue labeled 5% albumin. The mRNA and protein expression of ENaC were determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.
AFC in AngII group was significantly lower than that of control group [(6.16 ± 3.01)% vs. (16.10 ± 3.46)%, P<0.01], and AFC in ZD7155 pretreatment group was significantly higher than that of AngII group [(10.60 ± 2.05)% vs. (6.16 ± 3.01)%, P<0.05]. α-ENaC mRNA expression was significantly increased in AngII group compared with control group (0.663 ± 0.068 vs. 0.236 ± 0.030, P<0.01), but significantly decreased in ZD7155 pretreatment group when compared with AngII group (0.386 ± 0.061 vs. 0.663 ± 0.068, P<0.01). There was no significant difference in β-ENaC and γ-ENaC mRNA expression among three groups. Compared with control group, α-ENaC protein was significantly increased in AngII group (0.343 ± 0.053 vs. 0.145 ± 0.030, P<0.01), but β-ENaC and γ-ENaC proteins were significantly decreased (β-ENaC: 0.286 ± 0.038 vs. 0.512 ± 0.055, γ-ENaC : 0.144 ± 0.040 vs. 0.460 ± 0.066, both P<0.01). Compared with AngII group, α-ENaC protein was significantly lower(0.228 ± 0.045 vs.0.343 ± 0.053, P<0.01), whereas β-ENaC and γ-ENaC proteins were significantly higher (β-ENaC: 0.358 ± 0.043 vs. 0.286 ± 0.038, γ-ENaC: 0.220 ± 0.033 vs. 0.144 ± 0.040, both P<0.05) in ZD7155 pretreatment group.
Exogenous AngII modulates ENaC expression of gene and protein by AT1 receptor pathway, attenuates AFC, and aggravates lung edema.
Zhongguo wei zhong bing ji jiu yi xue = Chinese critical care medicine = Zhongguo weizhongbing jijiuyixue 09/2011; 23(9):551-4.
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ABSTRACT: Hunting lead compounds from natural products plays a vital role in finding successful drug candidates. The efficiency of screening campaigns is mainly determined by the validity of selected screening models. To screen desired lead compounds, researchers have developed a plethora of experimental screening models. However, the considerable diversity of screening models from animal models, tissue models, to cell models and so on, may cause some trouble in choosing the suitable one. This review provides a toolbox of experimental screening models that have been used to discover new drug candidates from natural products. Two screening indexes are designed for different research directions in this screening toolbox. Index I is proposed from the direction of screening different objective substance populations, including plant extracts, active fractions and pure compounds; index Π is according to screening different drug properties, including pharmacological properties, pharmacokinetic properties and affinity binding properties. We hope that the abbreviated bibliographies will help readers to quickly retrieve useful information by two screening indexes and provide certain reference value for choosing more appropriate screening models. Finally, we discuss ways of improving model systems, as well as future directions.
Fitoterapia 08/2011; 82(8):1141-51. · 1.85 Impact Factor
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ABSTRACT: Lysimachia christinae Hance is one of the herbs commonly used in traditional Chinese medicine for the treatment of cholecystitis and cholagogic efficiency.
The water extract of Lysimachia christinae Hance was investigated to see if it possesses cholecystitis and cholagogic effects through traditional pathways.
Lithocholic acid (LCA) and Escherichia coli were used to induce cholecystitis in adult guinea pigs. The present study evaluated the cholagogic effects of LCHE treatment on bile secretion and bile emptying in Sprague-Dawley rats and male Kunming mice.
The results showed that LCHE not only produced excellent anticholecystitis effects but also improved lesion severity in gallbladders induced by LCA. Similarly, LCHE administered to animals in the high-dose group exhibited an antibacterial effect in acute cholecystitis, and treatment with a mid-range or a high dose of LCHE resulted in an antipyretic effect, however, three doses of LCHE treatment groups had no effect on pathological change induced by Escherichia coli in gallbladder. Treatment with a high dose of LCHE significantly promoted bile secretion (0-90min, P<0.01), and treatment with a mid-range dose also significantly promoted bile secretion (30-60min P<0.05). Furthermore, treatment with a high dose of LCHE significantly promoted bile emptying (P<0.01).
Our results demonstrate that LCHE exhibits a marked anticholecystitis and cholagogic activity in animals, which supports previous claims of its use in traditional Chinese medicine.
Journal of ethnopharmacology 04/2011; 137(1):57-63. · 2.32 Impact Factor
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ABSTRACT: Blood glucose control has been a main focus for the treatment of type 2 diabetes. However, poor control and side-effect still are urgent problems to be solved. According to common blood glucose variability and its extremely deleterious diabetic-related complications in clinical practice, it should be considered as a potential key target. And β-cell failure has been approved that it can be reversible for early type 2 diabetes, which suggests another promising target. In this hypothesis, we propose a novel treatment strategy against on the two targets. An intelligent double-target drug delivery system is presented and characterized by dual-responsive functional gates for glucose sensitivity used controlled-release hypoglycemic agents and a sustained-release osmotic pump loaded drugs to repair impaired β-cell into the repository, respectively. The proposition may provide a new early therapeutic strategy for type 2 diabetes in order to better hold blood glucose homeostasis.
Medical Hypotheses 11/2010; 76(2):234-6. · 1.39 Impact Factor
