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In-vitro Study (in-vitro + study)
Selected AbstractsDefense mechanism to oxidative DNA damage in glial cellsNEUROPATHOLOGY, Issue 2 2004Takashi Iida Astrocytosis is a sequential morphological change of astrocytic reaction to tissue damage, and is associated with regulation of antioxidant defense mechanisms to reduce oxidative damage. The repair enzymes to oxidative DNA damage, oxidized purine-nucleoside triphosphatase (hMTH1) and a mitochondrial type of 8-oxoguanine DNA glycosylase (hOGG1,2a) in brain tumors and neurons of Alzheimer's disease, were previously reported. In the present study, glial expression of these repair enzymes under such pathological conditions as cerebrovascular diseases and metastatic brain tumors, were investigated. Furthermore, an in-vitro experiment using a glioma cell-line under oxidative stress was performed to verify the immunohistochemical results of post-mortem materials. As a result, hOGG1,2a immunoreactivities in reactive astrocytes were more intense than those to hMTH1. Oligodendrocytes of acute or subacute stage of brain infarction were strongly immunoreactive to both repair enzymes. In-vitro study revealed that, hOGG1,2a is constitutively expressed in both untreated glioma cells and the glioma cells under oxidative stress. However, although no immunoreactivity to hMTH1 was found in the control cells, accumulation of hMTH1 was rapidly induced by oxidative stress. These results indicate that the two repair enzymes to oxidative DNA damage are differentially regulated in glial cells, and that there is a difference in the expression of the repair enzymes between reactive astrocytes and oligodendrocytes. [source] CLINICAL USE OF THE NEWLY DEVELOPED ELECTRONIC RADIAL ULTRASOUND ENDOSCOPEDIGESTIVE ENDOSCOPY, Issue 1 2006Masami Ogawa Background:, Endoscopic ultrasonography (EUS) is widely accepted as a diagnostic tool for bilio-pancreatic and gastrointestinal tract diseases. Recently, an ultrasound endoscope with an electronic radial scan transducer has been developed. To evaluate the clinical usefulness of this system, its image quality, advantages and disadvantages were evaluated. Materials and methods:, Ultrasound endoscope with electronic radial scan transducer and its monitor unit were used. The direction of the imaging plane was similar to that of the mechanical radial models. Color Doppler function and tissue harmonic imaging were feasible by this system. To evaluate this endoscope, we investigated the image quality and distance resolution by in-vitro study using thin papers, and 50 patients were examined by this system. Results:, Comparison with the mechanical radial endoscope GF-UM2000 revealed that the image quality was almost equivalent. However, the ultrasound penetration of the electronic radial scanner was better and more satisfactory with less echoic reduction. In addition, the blood-flow signal could be obtained by using the color Doppler function. In contrast, the diameter of the new endoscope was bigger than the advanced mechanical radial models, the monitor unit was bigger than that of the mechanical radial system, and the operation of this unit was complicated. Conclusion:, A prototype of the ultrasound endoscope with electronic radial scan showed satisfactory results regarding the image quality, ultrasound penetration, and clinical diagnosis. The blood flow could be investigated by using the color Doppler function, which is useful to diagnose lesions and detect involvement of the blood vessels in cancers. [source] Amiodarone Attenuates Fluoride-induced Hyperkalemia in VitroACADEMIC EMERGENCY MEDICINE, Issue 2 2003Mark Su MD Abstract Poisoning by hydrofluoric acid or fluoride salts results in hypocalcemia, hypomagnesemia, and hyperkalemia with subsequent cardiac dysrhythmias. In previous studies, quinidine attenuated fluoride-induced hyperkalemia in vitro, and enhanced survival in animals. Like quinidine, amiodarone is a potassium channel blocker, although amiodarone is more familiar to clinicians due to its recent inclusion in advanced cardiac life support (ACLS) protocols. Objectives: This in-vitro study of human erythrocytes was designed to determine whether amiodarone could attenuate fluoride-induced hyperkalemia. Methods: Six healthy volunteers each donated 60 mL of blood on three occasions. Each specimen was divided into 12 tubes, incubated at 37°C, and oxygenated with room air. An aqueous sodium fluoride (F,) solution was added to tubes 1,9. Incremental amounts of quinidine were added to tubes 1,4 (Q1,Q4) to attain calculated concentrations of 0.73 ,g/mL, 1.45 ,g/mL, 2.9 ,g/mL, and 5.8 ,g/mL, respectively. Incremental amounts of amiodarone were added to tubes 5,8 (A1,A4) to attain calculated concentrations of 0.38 ,g/mL, 0.75 ,g/mL, 1.5 ,g/mL, and 3.0 ,g/mL, respectively. Tubes 9,12 were controls for each of F,, amiodarone, quinidine alone, and no additive, respectively. Extracellular potassium concentration ([K+]) was followed, and an objective endpoint was defined as the rise in potassium concentration at 6 hours. Results: Fluoride produced a significant change in [K+] by 6 hours in all samples. Quinidine produced a J-shaped curve in its ability to attenuate the rise in [K+], with only one concentration, Q3, demonstrating significance versus tube 9 (control). Amiodarone also demonstrated a J-shaped dose,response effect, with statistical significance at A1, A2, and A3 versus tube 9 (control). There was no significant difference among the effective concentrations (Q3, A1, A2, and A3) of both drugs. Conclusions: In this in-vitro model using human blood, amiodarone and quinidine both attenuated F, -induced hyperkalemia. Further study is indicated to determine whether amiodarone enhances survival in F, -poisoned animals. [source] Functional connections and pathways of coenzyme Q10-inducible genes: An in-silico studyIUBMB LIFE, Issue 10 2007Frank Döring Abstract Coenzyme Q10 (CoQ10, ubiquinone) is an essential cofactor in the electron transport chain, serves as a potent antioxidant in mitochondria and lipid membranes, and is often used as a dietary supplement for a number of diseases including cardiovascular diseases. Recently, we obtained evidence that CoQ10 (Kaneka Q10Ô) affects the expression of hundreds of human genes. To decipher the functional and regulatory connections of these genes, a literature search combined with transcription factor binding site analysis was performed using Genomatix BiblioSphere and MatInspector. This in-silico analysis revealed 17 CoQ10-inducible genes which are functionally connected by signalling pathways of G-protein coupled receptors, JAK/STAT, integrin, and beta-arrestin. Promoter analysis of these CoQ10-inducible genes showed one group of NF, B-regulated genes, namely IL5, thrombin, vitronectin receptor and C-reactive protein (CRP). Furthermore, a common promoter framework containing binding sites of the transcription factor families EVI1, HOXF, HOXC, and CLOX was identified in the promoters of IL5, CRP, and vitronectin receptor. The identified CoQ10-inducible genes and pathways play an important role in inflammatory response. Since these effects are based on an in-vitro study, the effect of CoQ10 on vascular health in vivo needs to be addressed in further animal and/or human intervention studies. IUBMB Life, 59: 628-633, 2007 [source] Diamond-coated sonic tips are more efficient for open debridement of molar furcationsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 5 2000A comparative manikin study Abstract Background/aims: The aim of this study was to compare the efficacy of open debridement of class II and III furcations by a new diamond-coated sonic instrument tip (Sonicparo) with a conventional sonic insert (Sonicrecall) and hand instruments (Gracey curettes). Method: Open debridement was simulated using a manikin head and standardised plastic teeth. The efficacy of debridement was examined by 3 parameters: residual root surface marker, ,tooth' weight loss and time taken for debridement. The teeth used were 1st and 2nd upper and lower molars. Upper left and lower right molars were chosen to represent class II furcation involvements and upper right and lower left molars class III furcation involvements. Each tooth was debrided 4 times with each instrument for both class of furcations. Results: The results of this study showed significantly less residual marker area comparing Sonicparo with Gracey curettes (mean difference 2.52 mm2, p<0.001). However, no significant differences in marker removal were observed between Sonicrecall inserts and the other instruments. Sonicparo inserts also took significantly less time to debride the furcation than Gracey curettes (mean difference 98.3 s, p<0.001) or Sonicrecall instruments (mean difference 74.3 s, p<0.001). However no significant differences were found between instruments concerning weight loss of the plastic teeth. Conclusions: It was concluded from this in-vitro study that the Sonicparo insert was a more efficient instrument for open molar furcation debridement than Sonicrecall and hand instruments (Gracey curettes) when considering both marker removal and debridement time. [source] Ion-pair Formation as a Strategy to Enhance Topical Delivery of Salicylic AcidJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 8 2000STELLA A. MEGWA An in-vitro study was carried out to determine the possibility of improving the efficiency of transdermal delivery of salicylate through human epidermis by ion-pair formers (alkylamines and quaternary ammonium ions). Further, the relationship between the physico-chemical properties of the counter-ions and salicylate flux was examined. It was found that flux can be related to the conductivity associated with the penetrant solution, molecular size of the counter-ion and lipophilicity expressed as either octanol/water partition coefficient of the ion pairs or the carbon chain-length of the counter-ions. Equations have been developed to predict salicylate flux from these physicochemical parameters. [source] | ||||||||||