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Various Substances (various + substance)
Selected AbstractsDentine demineralization when subjected to EDTA with or without various wetting agents: a co-site digital optical microscopy studyINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2008G. De-Deus Abstract Aim, To analyse quantitatively the chelating ability of ethylenediaminetetraacetic acid (EDTA) and three common EDTA-based associations with wetting agents. Methodology, Twelve maxillary human molars were selected, from which 3 mm thick discs were obtained from the cervical third of the root. Following the creation of standardized smear layer co-site microscopy image sequences of the dentine surface submitted to EDTA, EDTA plus 0.1% cetavlon® (Sigma Chemical Co., St Louis, MO, USA), EDTA plus 1.25% sodium lauryl ether sulphate and SmearClearÔ (Sybron Endo, Orange, CA, USA) were obtained after several cumulative demineralization times. Sixteen images were obtained of each dentine sample for each experimental time, at 1000× magnification. An image processing and analysis sequence was used to measure the area of open tubules for each experimental time. Thus, it was possible to follow the demineralization process and quantitatively analyse the effect of the various substances. The Student's t -test was used to assess differences between experimental groups. Results, EDTA solution had the strongest effect at all experimental times whilst the association of EDTA with wetting agents showed a weaker chelating effect and this difference was statistically significant (P < 0.05). Conclusions, (i) The EDTA solution had the strongest effect at all experimental times (P < 0.05); (ii) the association of EDTA with wetting agents did not improve the chelating power of the solution; (iii) co-site optical microscopy represents a powerful approach to compare directly, longitudinally and quantitatively the ability of the chelating solutions. [source] Electrosprayed polymer particles: Effect of the solvent propertiesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2009Chul Ho Park Abstract Electrospraying technology has been studied in many fields to produce particles of various substances from nanoscale to microscale sizes. Unlike pure liquids, droplets formed by electrospraying that are comprised of polymer solutions undergo additional solidification processes involving solvent evaporation, which primarily determine the particle size and morphology. Herein, the effects of the solvent properties on the morphology and dimensions of solidified particles were systematically studied. In general, the size of the solidified spherical particles with smooth surfaces reflected that of the initially formed liquid droplets, which could partially be estimated by theoretical equations developed for pure liquids. Particle sizes increased with an increase in polymer content and a decrease in the boiling point of the volatile solvent. Inhomogeneous drying processes related to phase separation or skin formation resulted in hollow, cuplike, and porous particle structures, with particle sizes and morphologies that were outside of the scope of the theoretical treatments. The selection of a proper solvent or solvent mixture seemed to be a convenient way to control the particle morphologies, such as hollow, cuplike, or porous structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Microbiological analysis of infected root canals from symptomatic and asymptomatic teeth with periapical periodontitis and the antimicrobial susceptibility of some isolated anaerobic bacteriaMOLECULAR ORAL MICROBIOLOGY, Issue 5 2003R. C. Jacinto The purpose of the present study was to investigate the correlation between the composition of the bacterial flora isolated from infected root canals of teeth with apical periodontitis with the presence of clinical signs and symptoms, and to test the antibiotic susceptibility of five anaerobic bacteria mostly commonly found in the root canals of symptomatic teeth against various substances using the E-test. Microbial samples were taken from 48 root canals, 29 symptomatic and 19 asymptomatic, using adequate techniques. A total of 218 cultivable isolates were recovered from 48 different microbial species and 19 different genera. Root canals from symptomatic teeth harbored more obligate anaerobes and a bigger number of bacterial species than the asymptomatic teeth. More than 70% of the bacterial isolates were strict anaerobes. Statistical analysis used a Pearson Chi-squared test or a one-sided Fisher's Exact test as appropriate. Suggested relationships were found between specific microorganisms, especially gram-negative anaerobes, and the presence of spontaneous or previous pain, tenderness to percussion, pain on palpation and swelling amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. The lowest susceptibility rate was presented by Prevotella intermedia/nigrescens against Penicillin G. Our results suggested that specific bacteria are associated with endodontic symptoms of infected teeth with periapical periodontitis and the majority of the anaerobic bacterial species tested were susceptible to all antibiotics studied. [source] Comorbid Schizophrenia and Substance Abuse: A Review of Epidemiology and CourseTHE AMERICAN JOURNAL ON ADDICTIONS, Issue 5 2006Joseph Westermeyer MD, PhDArticle first published online: 18 FEB 2010 Over the last dozen years, our knowledge regarding comorbid schizophrenia (SCZ) and substance use disorder (SUD) has evolved in several ways. First, the rate of lifetime comorbid SCZ-SUD appears to have increased another 20,30%, so now about 70,80% of persons with SCZ have lifetime SUD. Second, early remission of SUD has become commonplace among patients with SCZ, perhaps outnumbering the number of SCZ-only patients as well as those with active SCZ-SUD. Third, sustained SUD remission is well demonstrated, though the rates may yet be low. Fourth, research on comorbid SCZ-SUD is filling out our knowledge in many areas, including the characteristics of SCZ patients at risk for SUD, reasons SCZ patients seek out substances, effects of various substances on SCZ course and symptoms, and obstacles to SUD recovery in people with SCZ. The influence of SUD treatment and self-help on epidemiology and course has not been adequately evaluated. Primary prevention and early treatment of SUD in SCZ patients are still relatively neglected, though they offer our greatest hope for enhancing the lives of people with SCZ and improving the cost efficacy of care. [source] Antigenic as Well as Nonantigenic Stimuli Induce Similar Middle Ear Responses in the Rat,THE LARYNGOSCOPE, Issue 2 2003Edith L. G. M. Tonnaer MSc Abstract Objectives/Hypothesis The observation that during otitis media many different types of micro-organisms have been cultured from effusions indicate that, once present in the middle ear cavity, most types of micro-organisms are able to trigger an inflammatory reaction leading to otitis media. The present study was designed to determine the middle ear response after injection of different substances into the middle ear cavity. Study Design To determine whether and to what extent an inflammatory response of the middle ear depends on the entering agent, the response in the tympanic cavity was studied by otomicroscopy and histological examination after inoculation of various substances. Methods Lewis rats were inoculated in transtympanic fashion either with live or heat-killed bacteria (pathogenic and nonpathogenic), Keyhole limpet hemocyanin, active charcoal, or saline. The mucosal response of the challenged middle ears was studied histologically. Results Irrespective of the inoculated substance, no essential differences in the mucosal response were found. The intensity of the inflammatory response was greater when live bacteria were inoculated. Conclusions The present study demonstrates that any substance reaching the middle ear cavity is likely to induce otitis media. These observations emphasize the role of the eustachian tube as "porte d'entrée" in the pathogenesis of this disorder. Determination of specific aspects of the eustachian tube involved in protection or in facilitating bacterial translocation will be important for the understanding of the pathogenesis of otitis media and the subsequent development of new therapeutic strategies. In addition, elucidation of bacterial factors involved in the process of colonization and translocation will be of equal importance. [source] Tissue Distribution of P-Glycoprotein in CatsANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2009S. Van Der Heyden Summary Permeability glycoprotein (P-gp) is a membrane-bound efflux pump that exports various substances out of the cell. Variations in P-gp expression play an important role in susceptibility to toxic substances, drug efficacy and disease risk. In the present study, the distribution of the MDR1 -gene product P-gp was determined in normal tissues of domestic shorthair cats using immunohistochemistry. Two monoclonal antibodies C494 and C219 were used, recognizing a different epitope on the human P-gp molecule. A consistent positive immunolabelling was obtained. The tissue distribution and cellular locations with antibody C494 were similar to those in man and dogs; with liver, colon, adrenal cortex and brain capillaries being consistently and intensely labelled. However, the immunolabelling in the kidney was in contradiction to man and dogs. The C219 antibody seems to react with a specific form of P-gp, only expressed in feline tissues with a barrier function, i.e. endothelia of the brain, testes and ovaries, and intestinal epithelial cells in contact with the lumen. [source] Plant-derived compounds and extracts with potential as aphid repellentsANNALS OF APPLIED BIOLOGY, Issue 2 2009S.E. Halbert Abstract We devised a method for screening various substances for possible aphid repellency. Corn leaf aphids (Rhopalosiphum maidis) were released in an arena and allowed to select paired green tiles coated with petroleum jelly alone or petroleum jelly containing 1% of the substance being tested. Aphids adhering to tiles were counted 24 h later. If significantly fewer aphids landed on treated tiles, the substance was considered to have potential for repelling aphids. Fifty-five substances were tested. Most showed no activity, but several including ,-citronellol, farnesol, geraniol, linalool, oils distilled from several species of Artemisia and Achillea millefolia (yarrow) oil showed some promise. [source] Comparative analysis of ATP-binding cassette (ABC) transporter gene expression levels in peripheral blood leukocytes and in liver with hepatocellular carcinomaCANCER SCIENCE, Issue 6 2004Mohsen A. Moustafa ATP-binding cassette (ABC) transporters comprise a superfamily of similar proteins involved in transmembrane transport of various substances. ABC transporter family members in the liver participate in bile formation and lipid metabolism. In order to assess whether peripheral blood leukocytes (PBL) are available as a surrogate for determination of the expression of ABC transporter genes in the liver, we compared ABC transporter gene expression levels in PBL with those in liver tissues from patients with hepatocellular carcinoma (HCC). We measured ABCA1, A2, B1-B4, C1°C5, G1 and G2 gene expression levels in PBL, and cancerous and non-cancerous portions of liver from patients with hepatocellular carcinoma by means of real time reverse-transcription (RT)-PCR. We could not detect ABCC5 expression in any tissue of the liver. Close correlations between ABCA2, C1 and 67 in PBL and in non-tumor tissues of the liver were found. Compared with the non-tumor part, HCC tissue expressed lower levels of ABCA1, B4 and G2. We think monitoring of ABCA2, C1 and G7 gene expression levels in PBL will be useful for selection of anti cancer agents and monitoring of drug resistance of HCC. Administration of chemotherapeutic agents which are substrates of ABCA1, B4 and G2 should be effective for the treatment of HCC. (Cancer Sci 2004; 95: 530,536) [source] We're still under pressure: postoperative hypertonyACTA OPHTHALMOLOGICA, Issue 2009I STALMANS Purpose Postoperative hypertony is a frequent complication after trabeculectomy. This problem may occur from the early, to the late stages, and may be an acute or chronic situation. The aim of this lecture is to review the various causes with their clinical presentation and therapeutic strategy. Methods An overview will be provided on the different mechanisms that may cause hypertony after trabeculectomy, ranging from tight flap sutures or blocking of the constructed channel by various substances, over encapsulation and failing bleb to steroid response. For each of these situations, the clinical presentation and differential diagnosis will be discussed. Finally, the therapeutic options will be reviewed. Photographic and video material will be used to illustrate the various clinical presentations and therapeutic interventions. Conclusion This lecture will provide the audience with a practically oriented overview of the clinical management of hypertony after trabeculectomy. [source] | |||||||||||||