Home About us Contact
|
Home About us Contact | ||
|
|
||
Clearance Time (clearance + time)
Selected AbstractsMeasurement of blood clearance time by Limulus G test of Candida -water soluble polysaccharide fraction, CAWS, in miceFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2000Kiyoshi Kurihara Abstract The Limulus G test, responsive to ,-1,3- d -glucan, is a well-established method for the detection of invasive fungal infection. We have recently found that Candida albicans released a water-soluble polysaccharide fraction (CAWS) into synthetic medium (Uchiyama et al., FEMS Immunol. Med. Microbiol. 24 (1999) 411,420). CAWS was composed of a mannoprotein-,-glucan complex and activated Limulus factor G, and thus would be similar to the Limulus active substance in patient's blood. In a preliminary investigation, we have found that CAWS is lethal when administered intravenously in a murine system. In this study, we examined the toxicity and then the fate of CAWS in mice. The lethal toxicity was strain-dependent and strain DBA/2 was the most resistant. The toxicity was, at least in part, reduced by salbutamol sulfate and prednisolone treatment in the sensitive strains. On intravenous administration, the half clearance time (t1/2) was approximately 40 min in mice (DBA/2). On intraperitoneal administration, CAWS appeared in the blood with a peak concentration at 1 h. In order to establish a treatment plan, it is important to demonstrate the onset and the termination of deep-seated mycosis. The Limulus G test is suitable for the above purpose; however, it is necessary to fully understand the fate of ,-1,3- d -glucan in patients' blood [source] Nasal nitric oxide in objective evaluation of chronic rhinosinusitis therapyALLERGY, Issue 6 2006S. M. Ragab Background:, The assessment of the response of chronic rhinosinusitis (CRS) to therapy is difficult. Computerized tomographic (CT) scans cannot be repeatedly used so measures such as symptom scores, endoscopic findings, and parallel measures such as saccharin clearance time are employed instead. Objective:, To study the effect of CRS therapy on nasal nitric oxide and to see whether nasal nitric oxide level changes correlate with other assessments. Methods:, The study was a prospective randomized trial of patients with CRS, with or without polyps, who had failed initial medical therapy with douching and nasal corticosteroids and who then had abnormal CT scans. They were treated either medically or surgically, with follow up at 6 and 12 months whilst still taking nasal corticosteroids. Nasal nitric oxide was measured initially and at 6 and 12 months as well as symptom scores, endoscopy, polyp grading, and saccharin clearance time. Results:, Initial absolute nasal nitric oxide levels correlated inversely with CT scan changes, (P < 0.001). The percentage rise in nasal nitric oxide seen on both medical and surgical treatment correlated with changes in symptom scores (P < 0.001), saccharin clearance time (P < 0.001), endoscopic changes (P < 0.001), polyp grades (P < 0.05 at 6 months, P < 0.01 at 12 months) and surgical scores (P < 0.01). There was no significant correlation with age, sex, smoking or allergy. Conclusion:, Nasal nitric oxide, which is easily measured, provides a valuable non-invasive objective measure of the response of CRS to therapy. Topical nasal corticosteroids may be needed to reduce the contribution of nasal epithelial nitric oxide and allow that emanating from the sinuses to be measured. [source] WST11, A Novel Water-soluble Bacteriochlorophyll Derivative; Cellular Uptake, Pharmacokinetics, Biodistribution and Vascular-targeted Photodynamic Activity Using Melanoma Tumors as a Model,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Ohad Mazor ABSTRACT WST11 is a novel negatively charged water-soluble palladiumbacteriochlorophyll derivative that was developed for vascular-targeted photodynamic therapy (VTP) in our laboratory. The in vitro results suggest that WST11 cellular uptake, clearance and phototoxicity are mediated by serum albumin trafficking. In vivo, WST11 was found to clear rapidly from the circulation (t1/2= 1.65 min) after intravenous bolus injection in the mouse, whereas a longer clearance time (t1/2= 7.5 min) was noted in rats after 20 min of infusion. The biodistribution of WST11 in mouse tissues indicates hepatic clearance (t1/2= 20 min), with minor (kidney, lung and spleen) or no intermediary accumulation in other tissues. As soon as 1 h after injection, WST11 had nearly cleared from the body of the mouse, except for a temporal accumulation in the lungs from which it cleared within 40 min. On the basis of these results, we set the VTP protocol for a short illumination period (5 min), delivered immediately after WST11 injection. On subjecting M2R melanoma xenografts to WST11-VTP, we achieved 100% tumor flattening at all doses and a 70% cure with 9 mg/kg and a light exposure dose of 100 mW/cm2. These results provide direct evidence that WST11 is an effective agent for VTP and provide guidelines for further development of new candidates. [source] The effect of hypertonicity on nasal mucociliary clearanceCLINICAL OTOLARYNGOLOGY, Issue 6 2000J.J. Homer The effect of the tonicity of saline nasal douching solutions on mucociliary clearance was studied in order to ascertain whether hypertonicity conferred any advantage. Thirty-eight normal subjects were included in a randomised double-blind crossover trial. Saline douching solutions of 0.9%, 3% and 5% tonicity were used and mucociliary clearance was measured by the saccharin clearance time (SCT). The resultant SCT after administration of 5% saline was significantly reduced compared to both 0.9% (P = 0.005) and 3% saline (P = 0.04). There was no difference between 0.9% and 3% saline administration. Thus hypertonic saline solutions improve mucociliary clearance, although this was only observed with solutions of 5% tonicity. The effect is probably brought about by changes in mucus rheology. [source] Microdebriders Used in Functional Endoscopic Sinus Surgery: Secondary Analysis and Validation of a New Tissue Model,THE LARYNGOSCOPE, Issue 9 2005Sandeep P. Dave MD Abstract Objectives/Hypothesis: To validate a previously reported in vitro tissue model for microdebrider comparison and determine which microdebrider, tissue type, blade type, and suction strength is most efficient. Specifically, the goal of the secondary analysis is to expand on the results of the preliminary analy-sis by increasing the sample size, and introduce an aspiration efficiency score (AES) to facilitate microdebrider comparison. Study Design: Prospective randomized comparison. Methods: A prospective randomized comparison of the Diego Powered Dissector and XPS 3000 Powered ENT System was conducted using a soft tissue and a firm tissue model. In addition to evaluating tissue aspiration with straight and angled blades, clogging rates and clearance times were measured. Both standard wall suction and liposuction were used. Basic statistical analysis, a one-way analysis of variance, and a post hoc Student's t test were performed to compare outcomes. Results: With standard wall suction, the microdebriders were equivalent for the overall microdebrider comparison. For the "head to head" comparison with standard wall suction, the devices were also equivalent when using the straight blades, but the XPS 3000 aspirated more tissue when using the angled blades. With liposuction, the XPS 3000 and liposuction independently aspirated more tissue but clogged more often compared with the Diego PD and regular suction. The aspiration efficiency of soft tissue (oysters) and straight blades was superior compared with firm tissue (scallops) and angled blades. For the "head to head" comparison with liposuction, the XPS 3000 aspirated more tissue regardless of tissue type, but the Diego PD clogged less with firm tissue (scallops). Overall, the AES favored the XPS 3000, soft tissue (oysters), straight blades, and liposuction. Conclusion: Our tissue model represents a reliable and reproducible means of microdebrider comparison. Statistically significant differences between the Diego PD and XPS 3000, as well as between tissue types, blade types, and suction strengths, are reported. Using these results, microdebrider manufacturers can adopt similar tissue models, expand on the current AES, and include other commercially available microdebrider devices to test and report product performance to the consumer. Perhaps an optimal open to closed ratio or liposuction pressure can be determined that yields the greatest tissue aspiration with the fewest number of clogs. [source] Distribution sensitivity in a highway flow modelAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 6 2009Andrew M. Ross, Article first published online: 13 FEB 200 Abstract We examine a model of traffic flow on a highway segment, where traffic can be impaired by random incidents (usually, collisions). Using analytical and numerical methods, we show the degree of sensitivity that the model exhibits to the distributions of service times (in the queueing model) and incident clearance times. Its sensitivity to the distribution of time until an incident is much less pronounced. Our analytical methods include an M/Gt/, analysis (Gt denotes a service process whose distribution changes with time) and a fluid approximation for an M/M/c queue with general distributions for the incident clearance times. Our numerical methods include M/PH2/c/K models with many servers and with phase-type distributions for the time until an incident occurs or is cleared. We also investigate different time scalings for the rate of incident occurrence and clearance. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||