Search results for "Clearance"
showing 10 items of 116 documents
Subacute effects of ozone exposure on cultivated human respiratory mucosa.
2001
This study was designed to investigate subacute effects of long-term exposure of both healthy and chronically inflamed human respiratory mucosa to ozone. Functional and metabolic effects on ciliary beat frequency (CBF), release of interleukin 8 (IL-8), interleukin 4 (IL-4), and γ interferon (g-INF), as well as cellular viability and cytotoxicity, were monitored. Cell cultures of 60 specimens (healthy mucosa: n = 30, inflamed mucosa: n = 30) were exposed to synthetic air and to ozone-enriched synthetic air in different concentrations of WO, 500, and WOO μg/m3. Continuous expositions were performed using an air/liquid interface cell culture technique for a period of 4 weeks. CBF was monitore…
The tear turnover and tear clearance tests – a review
2018
Introduction. The aim is to provide a summary of methods available for the assessment of tear turnover and tear clearance rates. The review defines tear clearance and tear turnover and describes their implication for ocular surface health. Additionally, it describes main types of techniques for measuring tear turnover, including fluorescein tear clearance tests, techniques utilizing electromagnetic spectrum and tracer molecule and novel experimental techniques utilizing optical coherence tomography and fluorescein profilometry. Areas covered. Internet databases (PubMed, Science Direct, Google Scholar) and most frequently cited references were used as a principal resource of information on t…
Polyoxypregnanes as safe, potent, and specific ABCB1-inhibitory pro-drugs to overcome multidrug resistance in cancer chemotherapy in vitro and in vivo
2021
Multidrug resistance (MDR) mediated by ATP binding cassette subfamily B member 1 (ABCB1) is significantly hindering effective cancer chemotherapy. However, currently, no ABCB1-inhibitory drugs have been approved to treat MDR cancer clinically, mainly due to the inhibitor specificity, toxicity, and drug interactions. Here, we reported that three polyoxypregnanes (POPs) as the most abundant constituents of Marsdenia tenacissima (M. tenacissima) were novel ABCB1-modulatory pro-drugs, which underwent intestinal microbiota-mediated biotransformation in vivo to generate active metabolites. The metabolites at non-toxic concentrations restored chemosensitivity in ABCB1-overexpressing cancer cells v…
Considerations on acute otitis externa for its optimized treatment
2009
Abstract Introduction and objectives To evaluate the optimal treatment for diffuse acute otitis externa (DAOE) by means of a new staging system based on clinical and otoscopic findings. Methods Monitoring of otitis cases diagnosed at our centre over the last 21 months (n = 1026), taking into account those who returned for a second visit, either via the emergency room or with a prior appointment. Staging of otitis externa by degree of obstruction of the external auditory canal (EAC): under 25% (type I, n = 174); between 25% and 75% (type II, n = 277); over 75% (type III, n = 359); total obstruction due to organized oedema (type IV, n = 216). Results In most cases at an advanced stage, the ca…
Comparison of cystatin C and creatinine-based glomerular filtration rate formulas with 51Cr-EDTA clearance in patients with cirrhosis
2011
Renal function is an important predictor of survival in cirrhosis and liver transplantation. GFR estimates using serum cystatin C (CysC) are proposed as better predictors of renal function than ones on the basis of serum creatinine (Cr). Our aims were: (1) evaluate correlations between serum CysC and different methods of creatinine measurements; (2) compare CysC and Cr GFR formulas with (51)Cr-EDTA; and (3) evaluate liver-related parameters potentially influencing GFR.254 blood samples in 65 patients with cirrhosis correlating CysC with four Cr methods were used; another 74 patients comparing (51)Cr-EDTA GFR to Modification of Diet in Renal Disease and Larsson and Hoek formulas for CysC wer…
Dose-dependent absorption and elimination of cefadroxil in man.
1991
The pharmacokinetic behaviour of cefadroxil was dose-dependent in healthy male volunteers following the oral administration of single doses of 5, 15, and 30 mg.kg-1. As the dose of cefadroxil increased from 5 to 15 and 30 mg.kg-1, the peak plasma concentrations, normalized to 5 mg.kg-1, decreased significantly from 15.1 to 10.7 and 7.6 mg.l-1, while the corresponding normalized areas under the plasma concentration-time curves from 0 to 2 h decreased significantly from 1258 to 946 and 801 min.mg.l-1. When the same subjects were given 5 mg.kg-1 of cefadroxil together with 45 mg.kg-1 of cephalexin, the absorption of cefadroxil was slowed to a similar or greater extent than with the high dose o…
'Prefrontal' cognitive performance of healthy subjects positively correlates with cerebral FDOPA influx: an exploratory [18F]-fluoro-L-DOPA-PET inves…
2006
Dopamine neurotransmission influences those cognitive processes, which are generally regarded as prefrontal cortical functions. In previous positron‐emission‐tomography (PET) studies, net blood‐brain clearance of [(18)F]‐fluoro‐l‐DOPA (FDOPA) correlated with impaired cognitive performance in patients with Parkinson's disease or schizophrenia. We hypothesized that FDOPA influx also correlates with performance of cognitive tasks associated with prefrontal functioning in healthy volunteers. The net blood‐brain clearance of FDOPA (K [Formula: see text]) was mapped in a group of 11 healthy volunteers and calculated in striatal volumes‐of‐interest. The Wisconsin‐Card‐Sorting‐Test (WCST), Stroop‐T…
Probable progress in the therapy of organophosphate poisoning
1976
Whether or not extracorporeal hemodialysis or hemoperfusion with coated activated charcoal might be used in eliminating organophosphates following poisoning with nitrostigmine, demeton-S-methyl sulfoxide, or dimethoate was here examined. Nitrostigmine could not be hemodialysed. The other two organophosphates, on the other hand could be well eliminated from the blood by hemodialysis. The clearance rates for demeton-S-methyl sulfoxide and dimethoate were 52.98 ml/min and 59.07 ml/min respectively, at a blood flow rate of 100 ml/min. The clearance values for hemoperfusion with coated activated charcoal were higher under the same trial conditions, the values being 83.70 ml/min for demeton-S-met…
The viral clearance in interferon-treated chronic hepatitis C is associated with increased cytotoxic T cell frequencies
1999
Abstract Background/Aims: Cytotoxic T lymphocytes have been demonstrated in peripheral blood and liver tissue of patients with chronic hepatitis C virus infection, but their significance for viral clearance is unknown. Therefore, we analyzed hepatitis C virus-specific cytotoxic T lymphocyte precursor frequencies in chronic hepatitis C virus carriers during interferon-α treatment. Methods: Blood mononuclear cells or CD8+ T cells from HLA-A2 positive and negative patients and controls were analyzed in chromium-release assays using a panel of 18 synthetic peptides from the HCV core, E1 and NS4 antigens bearing HLA-A2 binding motifs. Specific cytotoxic T lymphocyte precursor frequencies were st…
Topical Antibiotic, Antifungal, and Antiseptic Solutions Decrease Ciliary Activity in Nasal Respiratory Cells
2002
This study was designed to investigate whether topical solutions, as they are used in the treatment of selected cases of rhinosinusitis, influence nasal mucociliary clearance. The objective of this study was to evaluate the effects of the following topical solutions on the ciliary beat frequency (CBF) of nasal respiratory cells: ofloxacin as an antibiotic; Betadine and hydrogen peroxide (H2O2) as antiseptic; and amphotericin B, itraconazole, and clotrimazole as antifungal solutions. Differences are described between effects of each of these substances and we clarify whether ciliotoxic effects are dose dependent and if they can be reduced or eliminated by diluting the concentration of the a…