943 resultados para Successive Overrelaxation method with 2 parameters


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Anemia screening before blood donation requires an accurate, quick, practical, and easy method with minimal discomfort for the donors. The aim of this study was to compare the accuracy of two quantitative methods of anemia screening: the HemoCue 201(+) (Aktiebolaget Leo Diagnostics) hemoglobin (Hb) and microhematocrit (micro-Hct) tests. Two blood samples of a single fingerstick were obtained from 969 unselected potential female donors to determine the Hb by HemoCue 201(+) and micro-Hct using HemataSTAT II (Separation Technology, Inc.), in alternating order. From each participant, a venous blood sample was drawn and run in an automatic hematology analyzer (ABX Pentra 60, ABX Diagnostics). Considering results of ABX Pentra 60 as true values, the sensitivity and specificity of HemoCue 201(+) and micro-Hct as screening methods were compared, using a venous Hb level of 12.0 g per dL as cutoff for anemia. The sensitivities of the HemoCue 201(+) and HemataSTAT II in detecting anemia were 56 percent (95% confidence interval [CI], 46.1%-65.5%) and 39.5 percent (95% CI, 30.2%-49.3%), respectively (p < 0.001). Analyzing only candidates with a venous Hb level lower than 11.0 g per dL, the deferral rate was 100 percent by HemoCue 201(+) and 77 percent by HemataSTAT II. The specificities of the methods were 93.5 and 93.2 percent, respectively. The HemoCue 201(+) showed greater discriminating power for detecting anemia in prospective blood donors than the micro-Hct method. Both presented equivalent deferral error rates of nonanemic potential donors. Compared to the micro-Hct, HemoCue 201(+) reduces the risk of anemic female donors giving blood, specially for those with lower Hb levels, without increasing the deferral of nonanemic potential donors.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Aim Chagas` disease is an endemic parasitosis found in Latin America. The disease affects different organs, such as heart, oesophagus, colon and rectum. Megacolon is the most frequent long-term complication, caused by damage to the myoenteric and submucous plexus, ultimately leading to a functional barrier to the faeces. Patients with severe constipation are managed surgically. The study aimed to analyse the 10-year minimum functional outcome after rectosigmoidectomy with posterior end-to-side anastomosis (RPESA). Method A total of 21 of 46 patients were available for follow up. Patients underwent clinical, radiological and manometric evaluation, and the results were compared with preoperative parameters. Results Of the 21 patients evaluated, 81% (17) were female, with a mean age of 60.6 years. Good function was achieved in all patients, with significant improvement in defaecatory frequency (P < 0.0001), usage of enemas (P < 0.0001) and patient satisfaction. Barium enema also showed resolution of the colonic and rectal dilatation in 19 cases evaluated postoperatively. Conclusion Minimal 10-year follow up of RPESA showed excellent functional results, with no recurrence of constipation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND: Mesenchymal stem cells (MSCs) have been considered for human regenerative therapy applications, and safe culture and expansion protocols are needed especially in the context of interspecies contamination. Human platelet lysate (PL) has been proposed as animal serum substitute during in vitro MSC expansion. In this work, a simplified and efficient method to obtain autologous PL to replace animal serum in cell culture applications is described. STUDY DESIGN AND METHODS: PL obtained by freezing and centrifugation procedures was tested as medium supplement for human adipose mesenchymal stem cell (hASC) culture. Differential proliferation, immunophenotypic changes, and differentiation under PL or fetal bovine serum (FBS) were assessed. RESULTS: In contrast to 10% FBS supplementation, cell population doubling time was significantly lower when hASCs were cultured with the same concentration of PL ( PL 22.9 +/- 1.5 hr vs. FBS 106.7 +/- 6.5 hr, t test, p < 0.05). Furthermore, hASCs maintained with 2.5% PL supplementation also showed satisfactory results. Immunophenotypic analysis revealed no differences between hASCs cultivated with PL or FBS supplementation and both cultures retained the potential to differentiate into adipose cells. These results demonstrate that autologous PL obtained from the same donor can be used as animal serum substitute in hASC culture. CONCLUSIONS: Taken together, evidence is provided that platelets provided by a single donor are sufficient to obtain PL for hASC propagation for clinical-scale applications mitigating the potential untoward side effects associated with the use of animal-derived reagents.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Traditional Periodic Acid Schiff has been extensively used, coupled with immunohistochemistry for epithelia or mesenchymal cells, to highlight renal tubular basement membrane (TBM). We recently tried to perform such technique in a 5/6 nephrectomy model of progressive renal fibrosis to demonstrate TBM disruption as an evidence for epithelial-mesenchymal transdifferentiation. Despite excellent basement membrane staining with traditional fuchsin-Periodic Acid Schiff, the interface between epithelial and mesenchymal cells was frequently blurred when revealed with 3`3 diaminobenzidine tetrachloride-peroxidase. Also, it was inadequate when revealed with alkaline phosphatase-fast red. We devised a triple staining method with Periodic Acid-Thionin Schiff to highlight basement membrane in blue, after double immunostaining for epithelium and mesenchymal cells. Blue basement membrane rendered a brisk contrast and highlighted boundaries between epithelial-mesenchymal interfaces. This method was easy to perform and useful to demonstrate the TBM, yield a clear demonstration of the very focal TBM disruption found in this model of progressive renal fibrosis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background Chronic progressive external ophthalmoplegia is a mitochondrial myopathy that causes muscular or multisystem symptoms and has dysphagia as one manifestation. Aim To evaluate esophageal contractions in patients with chronic progressive external ophthalmoplegia. Methods We studied 14 patients with chronic progressive external ophthalmoplegia and 16 asymptomatic volunteers. The diagnosis of the disease was established by the clinical picture and by mitochondrial DNA analysis in skeletal muscle. We used the manometric method with a perfusion catheter that recorded the esophageal contractions at 2, 7, 12, 17, and 22 cm from the lower esophageal sphincter (LES). All subjects performed in the supine position 20 swallows of a 5-ml bolus of water at room temperature, ten every 30 s and ten every 10 s. Results The amplitude, duration, and area under the curve of contractions at 17 and 22 cm from the LES were lower in patients than in volunteers for swallows performed at 10-s and 30-s intervals (P < 0.01). There was no difference in contractions at 7 and 2 cm, except for the contractions at 2 cm after swallows performed at 30-s intervals. The interval between the onset of contractions between 7 and 2 cm and between 22 and 2 cm was lower in patients than in volunteers, with swallows performed every 10 s and every 30 s. Conclusions There is impairment of esophageal contractions in patients with chronic progressive external ophthalmoplegia, mainly in the proximal esophageal body.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objective. Endothelial impairment evaluation by sonographic measurement of flow-mediated dilatation (FMD) has become broadly used. However, this method has 2 main caveats: the dilatation depends on the baseline arterial diameter, and a high precision level is required. Vasodilatation leads to an amplified fall in impedance. We hypothesized that assessment of the pulsatility index change (PI-C) 1 minute after 5-minute forearm compression might evaluate that fall in impedance. The aim of this study was to compare the PI-C with FMD. Methods. Flow-mediated dilatation and the PI-C were assessed in 51 healthy women aged between 35.1 and 67.1 years. We correlated both FMD and the PI-C with age, body mass index, waist circumference, cholesterol level, high-density lipoprotein level, glucose level, systolic and diastolic blood pressure, pulse pressure, brachial artery diameter, simplified Framingham score, intima-media thickness, and carotid stiffness index. Intraclass correlation coefficients between 2 FMD and PI-C measurements were also examined. Results. Only FMD correlated with baseline brachial diameter (r=-0.53). The PI-C had a high correlation with age, body mass index, waist circumference, cholesterol level, systolic blood pressure, pulse pressure, simplified Framingham score, and intima-media thickness. The correlation between FMD and the PI-C was high (r=-0.66). The PI-C had a higher intraclass correlation coefficient (0.991) than FMD (0.836) but not brachial artery diameter (0.989). Conclusions. The PI-C had a large correlation with various markers of cardiovascular risk. Additionally, PI-C measurement does not require offline analysis, extra software, or electrocardiography We think that the PI-C could be considered a marker of endothelial function. However, more studies are required before further conclusions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We compared the lignin contents of tropical forages by different analytical methods and evaluated their correlations with parameters related to the degradation of neutral detergent fiber (NDF). The lignin content was evaluated by five methods: cellulose solubilization in sulfuric acid [Lignin (sa)], oxidation with potassium permanganate [Lignin (pm)], the Klason lignin method (KL), solubilization in acetyl bromide from acid detergent fiber (ABLadf) and solubilization in acetyl bromide from the cell wall (ABLcw). Samples from ten grasses and ten legumes were used. The lignin content values obtained by gravimetric methods were also corrected for protein contamination, and the corrected values were referred to as Lignin (sa)p, Lignin (pm)p and KLp. The indigestible fraction of NDF (iNDF), the discrete lag (LAG) and the fractional rate of degradation (kd) of NDF were estimated using an in vitro assay. Correcting for protein resulted in reductions (P < 0.05) in the lignin contents as measured by the Lignin (sa), Lignin (pm) and, especially, the KL methods. There was an interaction (P < 0.05) of analytical method and forage group for lignin content. In general, LKp method provided the higher (P < 0.05) lignin contents. The estimates of lignin content obtained by the Lignin (sa)p, Lignin (pm)p and LKp methods were associated (P > 0.05) with all of the NDF degradation parameters. However, the strongest correlation coefficients for all methods evaluated were obtained with Lignin (pm)p and KLp. The lignin content estimated by the ABLcw method did not correlate (P > 0.05) with any parameters of NDF degradation. There was a correlation (P < 0.05) between the lignin content estimated by the ABLadf method and iNDF content. Nonetheless, this correlation was weaker than those found with gravimetric methods. From these results, we concluded that the gravimetric methods produce residues that are contaminated by nitrogenous compounds. Adjustment for these contaminants is suggested, particularly for the KL method, to express lignin content with greater accuracy. The relationships between lignin content measurements and NDF degradation parameters can be better determined using KLp and Lignin (pm)p methods. (C) 2011 Elsevier B.V. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The objective of this study was to evaluate the influence of various pulse widths with different energy parameters of erbium:yttrium-aluminum-garnet (Er:YAG) laser (2.94 mu m) on the morphology and microleakage of cavities restored with composite resin. Identically sized class V cavities were prepared on the buccal surfaces of 54 bovine teeth by high-speed drill (n = 6, control, group 1) and prepared by Er:YAG laser (Fidelis 320A, Fotona, Slovenia) with irradiation parameters of 350 mJ/ 4 Hz or 400 mJ/2 Hz and pulse width: group 2, very short pulse (VSP); group 3, short pulse (SP); group 4, long pulse (LP); group 5, very long pulse (VLP). All cavities were filled with composite resin (Z-250-3 M), stored at 37A degrees C in distilled water, polished after 24 h, and thermally stressed (700 cycles/5-55A degrees C). The teeth were impermeabilized, immersed in 50% silver nitrate solution for 8 h, sectioned longitudinally, and exposed to Photoflood light for 10 min to reveal the stain. The leakage was evaluated under stereomicroscope by three different examiners, in a double-blind fashion, and scored (0-3). The results were analyzed by Kruskal-Wallis test (P > 0.05) and showed that there was no significant differences between the groups tested. Under scanning electron microscopy (SEM) the morphology of the cavities prepared by laser showed irregular enamel margins and dentin internal walls, and a more conservative pattern than that of conventional cavities. The different power settings and pulse widths of Er:YAG laser in cavity preparation had no influence on microleakage of composite resin restorations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aims of this study were: (1) to correlate surface (SH) and cross-sectional hardness (CSH) with microradiographic parameters of artificial enamel lesions; (2) to compare lesions prepared by different protocols. Fifty bovine enamel specimens were allocated by stratified randomisation according to their initial SH values to five groups and lesions produced by different methods: MC gel (methylcellulose gel/lactic acid, pH 4.6, 14 days); PA gel (polyacrylic acid/lactic acid/hydroxyapatite, pH 4.8, 16 h); MHDP (undersaturated lactate buffer/methyl diphosphonate, pH 5.0, 6 days); buffer (undersaturated acetate buffer/fluoride, pH 5.0, 16 h), and pH cycling (7 days). SH of the lesions (SH(1)) was measured. The specimens were longitudinally sectioned and transverse microradiography (TMR) and CSH measured at 10- to 220-mu m depth from the surface. Overall, there was a medium correlation but non-linear and variable relationship between mineral content and root CSH. root SH(1) was weakly to moderately correlated with surface layer properties, weakly correlated with lesion depth but uncorrelated with integrated mineral loss. MHDP lesions showed the highest subsurface mineral loss, followed by pH cycling, buffer, PA gel and MC gel lesions. The conclusions were: (1) CSH, as an alternative to TMR, does not estimate mineral content very accurately, but gives information about mechanical properties of lesions; (2) SH should not be used to analyse lesions; (3) artificial caries lesions produced by the protocols differ, especially considering the method of analysis. Copyright (C) 2009 S. Karger AG, Basel

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Introduction: In this retrospective study, we compared the cephalometric effects, the dental-arch changes, and the efficiency of Class II treatment with the pendulum appliance, cervical headgear, or extraction of 2 maxillary premolars, all associated with fixed appliance therapy. Methods: The sample of 82 patients with Class II malocclusion was divided into 3 groups: group 1 patients (n = 22; treatment time, 3.8 years) were treated with the pendulum appliance and fixed orthodontic appliances. Group 2 patients (n = 30; treatment time, 3.2 years) were treated with cervical headgear followed by fixed appliances; group 3 patients (n = 30; treatment time, 2.1 years) were treated with 2 maxillary premolar extractions and fixed appliances. The average starting ages of the groups ranged from 13.2 to 13.8 years. Data were obtained from serial cephalometric measurements and dental casts. The dental casts were analyzed with the treatment priority index. The treatment efficiency index was also used. Results: The 3 treatment protocols produced similar cephalometric effects, especially skeletally. Comparisons among the 2 distalizing appliances (pendulum and cervical headgear) and extraction of 2 maxillary premolars for Class II treatment showed changes primarily in the maxillary dentoalveolar component and dental relationships. The facial profile was similar after treatment, except for slightly more retrusion of the upper lip in the extraction patients. The treatment priority index demonstrated that occlusal outcomes also were similar among the groups. The treatment efficiency index had higher values for the extraction group. Conclusions: The effects of treatment with the pendulum appliance or cervical headgear and extraction of 2 maxillary premolars associated with fixed appliances were similar from both occlusal and cephalometric standpoints. Class II treatment with extraction of maxillary teeth was more efficient because of the shorter treatment time. Differences in maxillary incisor retraction should be noted, but these differences might have been due to greater maxillary dentoalveolar protrusion in the extraction group before treatment. (Am J Orthod Dentofacial Orthop 2009;136:833-42)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study evaluated the effect of 980-nm diode laser at different parameters on root canal dentin permeability associated with different irrigants. Seventy-five canines were sectioned at 15 mm from the apex, prepared mechanically up to #40 .02 instrument, and irrigated with 2 mL distilled water. Final irrigation (10 mL) was used as follows: (1) distilled water; (2) 1% NaOCl; (3) 17% ethylenediaminetetraacetic acid + a cationic surfactant cetyltrimethylammonium bromide (EDTAC). Laser was applied at 1.5 or 3.0 W as either continuous wave or pulsed wave (100 Hz). The teeth were then processed histochemically, the percentage of copper ion penetration into the dentin of the canal walls was counted, and the data were analyzed statistically with the Tukey-Kramer test (alpha < .01). When laser was associated with water, an increase in permeability was found, whereas permeability decreased when associated with EDTAC. Dentin permeability after laser irradiation was directly dependent on the solution used for final irrigation.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Polarized absorption and emission spectra of trigonal single crystals of an Er(III) complex coordinated to a heptadentate tripodal ligand are reported at temperatures between 8 and 298 K. The assigned energy levels below the onset of ligand absorption (< 25 000 cm(-1)) are fitted to a parametrized electronic Hamiltonian. The C-3 site symmetry of the Er(HI) ion requires eight parameters for a full description of the ligand field within a one-electron operator description. This compound shows unusually large splittings of the multiplets, and the fitted parameters imply that this heptadentate ligand imparts the largest ligand field reported for an Er(III) complex. The ligand field was also interpreted within the angular overlap model (AOM). We derive the AOM matrix to include both sigma and anisotropic pi bonding and show that a useful description of the C-3 ligand field can be made using only five parameters. The success of the AOM description is encouraging for applications on isomorphous complexes within the lanthanide series and in describing the ligand field of low-symmetry complexes with less parameters than in the usual spherical harmonic expansion.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Matrix metalloproteinases (MMPs) are a family of enzymes implicated in the degradation and remodeling of extracellular matrix and in vascularization. They are also involved in pathologic processes such as tumor invasion and metastasis in experimental cancer models and in human malignancies. We used gelatin zymography and inummohistochemistry to determine whether MMP-2 and MMP-9 are present in canine tumors and normal tissues and whether MMP production correlates with clinicopathologic parameters of prognostic importance. High levels of pro-MMP-9, pro-MMP-2, and active MMP-2 were detected in most canine tumors. Significantly higher MMP levels were measured in canine tumors than in nontumors, malignancies had higher MMP levels than benign tumors, and sarcomas had higher active MMP-2 than carcinomas. Cartilaginous tumors produced higher MMP levels than did nonsarcomatous malignancies, benign tumors, and normal tissues, and significantly greater MMP-2 than osteosarcomas and fibrosarcomas. Pro-MMP-9 production correlated with the histologic grade of osteosarcomas. The 62-kd form of active MMP-2 was detected only in high-grade, p53-positive, metastatic malignancies. Zymography proved to be a sensitive and quantitative technique for the assessment of MMP presence but has the limitation of requiring fresh tissue; inummohistochemistry is qualitative and comparatively insensitive but could be of value in archival studies. MMP presence was shown in a range of canine tumors, and their link to tumor type and grade was demonstrated for the first time. This study will allow a substantially improved evaluation of veterinary cancer patients and provides baseline information necessary for the design of clinical trials targeting MMPs.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

OBJECTIVE: To determine the severity of dapsone (DDS) acute intoxication – an uncommon medical event – using clinical and laboratory parameters. METHODS: Two hundred and seventy four patients with acute DDS intoxication, aged 1 month to 50 years old, were studied and classified into four age groups. Clinical evaluation was assessed through a protocol and correlated with laboratory parameters. Spectrophotometric methods were used to analyze methemoglobinemia (MHbp) and dapsonemia (DDSp). RESULTS: The most prevalent clinical sign of intoxication was cyanosis, seen in 65.7% of the patients and in 100% of children less than 5 years of age. According to laboratory criteria, MHbp-related severe clinical intoxication was seen in 56.2% and DDSp-related occurred in 58% of the patients. Regarding DDSp, intoxication was considered severe when 20 tablets (100 mg each) were ingested, a median of 29 mug/ml. Regarding MHbp, intoxication was severe when 7.5 tablets were ingested, a median of 38% of the total Hb. The correlation between MHbp and DDSp was statistically significant (n=144, r=0.32, p<0.05). Negative correlation was observed between MHbp and the time elapsed since DDS intake (n=124, r=-0.34, p<0.001). There was also a negative correlation between DDSp and the time elapsed since DDS intake (n=63, r=-0.35, p<0.0001). CONCLUSIONS: Longitudinal analysis showed a significant association between methemoglobinemia and the time elapsed after the intake (t), according to the equation: Dapsonemia = 12.9256 - 0.0682t + 0.234 methemoglobinemia

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo de Energia