Increased Thrombogenicity in Chronic Renal Failure in a Rat Model Induced by 5/6 Ablation/Infarction

PURPOSE: Abnormalities in hemostasis and coagulation have been suggested in chronic renal failure (CRF). In this study, we compared processes of thrombus formation between rats with CRF and those with normal kidney function. MATERIALS AND METHODS: CRF was induced by 5/6 ablation/infarction of the kidneys in Sprague-Dawley rats, and surviving rats after 4 weeks were used. Ferric chloride (FeCl3)-induced thrombosis in the carotid artery was induced to assess thrombus formation. Whole blood clot formation was evaluated using rotational thromboelastometry (ROTEM). Platelet aggregation was assessed with impedance platelet aggregometry. RESULTS: FeCl3-induced thrombus formation was initiated faster in the CRF group than in the control group (13.2±1.1 sec vs. 17.8±1.0 sec, p=0.027). On histological examination, the maximal diameters of thrombi were larger in the CRF group than in the control group (394.2±201.1 µm vs. 114.0±145.1 µm, p=0.039). In extrinsic pathway ROTEM, the CRF group showed faster clot initiation (clotting time, 59.0±7.3 sec vs. 72.8±5.0 sec, p=0.032) and increased clot growth kinetics (α angle, 84.8±0.2° vs. 82.0±0.6°, p=0.008), compared to the control group. Maximal platelet aggregation rate was higher in the CRF group than in the control group (58.2±0.2% vs. 44.6±1.2%, p=0.006). CONCLUSION: Our study demonstrated that thrombogenicity is increased in rats with CRF. An activated extrinsic coagulation pathway may play an important role in increasing thrombogenicity in CRF.

Optimization of a rat model of ferric chloride-induced carotid arterial thrombosis by ultrasonic continuous evaluation / 中国神经精神疾病杂志

Objective The aim of this study was to establish a reasonable protocol for a rat model of ferric chloride-induced carotid arterial thrombosis by ultrasonic continuous evaluation.Methods Twenty SD rats were randomly divided into four groups and then treated with 20％,30％,40％ or 50％ concentrations of FeCl3,respectively.The vascular conditions were evaluated by 14L ultrasonic probe,at 10 mins,15 mins,and 20 mins.We then selected the best group through the examination of the rate of spontaneous reperfusion of blood vessels and the rate of reperfusion after intravenous injection of urokinase.At the end of the experiment,vessels were fixed in 10％ formalin solution and stained with HE.Results After external application of FeCl3 on rat common carotid artery for 20 mins,the artery occlusion rate was 100％,20％,0％ and 0％ in animals receiving 50％,40％,30％ and 20％ FeCl3,respectively.After external application of FeCl3 on rat common carotid artery for 120 mins,the spontaneous revascularization rate was 0％ in 50％ concentration group whereas were 100％ in rest other groups (P＜ 0.001).In 50％ concentration group,the partial recanalization rate was 40％ after intravenous injection of urokinase.HE staining revealed that the thrombus was dense and the lumen was partially recanalized after the urokinase intervention in 50％ concentration group.Conclusion By use of uultrasonic continuous evaluation of ferric chloride-induced thrombosis of rat common carotid artery,we have demonstrated that external application of 50％ ferric chloride solution for 20 mins is effective for the formation of thrombus model,which may be suitable for the studv of thrombolysis.

Development of colorimetric method for the quantification of methyl salicylate in bulk and formulations.

Methyl salicylate is chemically methyl-O-hydroxybenzoate and act as an active ingredient in many topical analgesic preparations. It posses good counter irritant activity. In this present study, a colorimetric method is developed for the quantitative estimation of methyl salicylate, both in the bulk form and in the formulations. A dark bluish – purple colour is formed between methyl salicylate and ferric chloride reagent. The intensity of the colour is directly related to the concentration of methyl salicylate present. The developed method was simple and gave accurate and precise results. The developed colour had its maximum value of absorbance at 537 nm when scanned in the visible region. The absorbance of the coloured system was measured at 537 nm. Beer’s law was obeyed in the range of 12 to 72 μg/mL. The equation for the straight line was found to be, y = 0.0075 x + 0.002 with correlation coefficient value of 0.996. The developed method was applied to semi – solid formulations for the quantitative estimation of methyl salicylate. The percentage of recovery was between 99.62 % in the formulation. The method proved to be a convenient analytical tool for the quantity determination of methyl salicylate.

Remoção de carga orgânica recalcitrante de lixiviado de resíduos sólidos urbanos pré-tratado biologicamente por coagulação química-floculação-sedimentação / Removing recalcitrant organic load of landfill leachate from urban solid waste pretreated biologically by coagulation-flocculation-sedimentation

A utilização de pós-tratamentos físico-químicos no tratamento de lixiviados tem sido uma alternativa utilizada para a remoção da carga orgânica presente nesse efluente. Dessa forma, este artigo teve como objetivo avaliar a técnica de tratamento físico-químico pelo processo de coagulação química-floculação-sedimentação como alternativa para pós-tratamento de lixiviado tratado biologicamente. Para isso, utilizou-se o equipamento de reatores estáticos Jarteste, e os parâmetros monitorados para avaliar a eficiência do tratamento físico-químico foram cor verdadeira e demanda química de oxigênio (DQO). Por meio da técnica de planejamento fatorial e analisando-se os resultados obtidos, pôde-se verificar que as maiores remoções de cor e de DQO foram encontradas combinando-se dosagem de 400 mgFe+3/L com pH 3,0, alcançando-se 98 e 81% de remoção de cor e DQO, respectivamente.

The utilization of physical-chemical post treatment on landfill leachate has been an option employed to remove organic compounds from this effluent. In this way, this article aimed to evaluate the physical-chemical treatment by coagulation-flocculation-sedimentation as an alternative in the post-treatment of landfill leachate submitted to biological treatment. Consequently, it was used a Jar-test to monitor true color and chemical oxygen demand (COD) in order to evaluate the efficiency of the physical-chemical treatment. By means of factorial design and analyzing the results, it was found that the best removals of color and COD were attained by combining a dosage of 400 mg Fe+3/L with pH 3.0, achieving 98 and 81% of color removal and COD, respectively.

A Guinea Pig Model of Cochlear Ischemia / 听力学及言语疾病杂志

Objective To explore a new method for establishing an animal model of cochlear ischemia.Methods Thirty guinea pigs were randomized into three groups:normal group,operation group,ischemia group.Anterior inferior cerebellar artery(AICA)was exposed surgically via a skull base approach.In ischemia group,a small piece of filter paper containing FeCl3 was placed upon the AICA to induce thrombus formation.In operation group,AICA was only exposed.In normal group,nothing was done to animal.The blood flow of cochlea(CoBF)was continuously monitored with laser Doppler flowmeter.The thresholds of auditory brainstem response(ABR)were measured before,after each experiment,and one week after operation.The AICAs of ischemia group and operation group were resected and pathological sections were perfomed for observation of the details.Results After the administration of FeCl3,the CoBF decreased to 50% of the base level at 30 min.In the AICA pathological sections of ischemia group,white thrombus composed of cellulose,blood platelets and erythrocytes could be seen.The threshold of ABR in ischemia group increased significantly.Conclusion The method provides a relatively ideal model for ischemis of the inner ear and this model may be helpful in studying the mechanisms of hearing loss caused by chronic microcirculatory disorders.

Changes of TXA_2 and PGI_2 content and anticoagulative and fibrinolytic activity in the plasma in a rat model of topical FeCl_3-induced carotid artery thrombosis / 中国药理学通报

0.05).Ticlopidine could inhibit thrombosis induced by ferric chloride,but it did not influence TXB_2 and 6-keto-PGF_1? content and activities of AT-Ⅲ and PC in the plasma.Ticlopidine could enhance activity of t-PA in the plasma.It may be related to the decrease of t-PA consumption by inhibiting thrombosis.Antithrombosis action of ticlopidine may not be concerned to inhibiting production of TXB_2 of platelet.LMWH could inhibit thrombosis also,but it did not influence TXB_2 and 6-ketoPGF_(1?) content in the plasma.LMWH could enhance activities of t-PA and t-PA/PAI-1 ratio,which may be related to the promoting release of t-PA in vascular endothelial cells.LMWH could reduce activity of AT-Ⅲ,which may be concerned with combination of LMWH and AT-Ⅲ result in AT-Ⅲ consumption.Conclusion Ferric chloride may induce occlusive thrombosis in rats.Thrombosis may be associated with activation of platelet and blood coagulation system,lower of anticoagulative protein and fibrinolytic activity.