911 resultados para time-to-DLT
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Carotid artery stenosis due to arteriosclerosis increases the risk of cerebral ischemia via embolic phenomena or reduced blood flow. The changes in cerebral perfusion that may occur after treatment are not clearly understood. This study evaluated the changes in cerebral microcirculation following carotid angioplasty with stenting (CAS) under cerebral protection with filters using ultrafast gradient echo (GRE) perfusion weighted imaging (PWI) with magnetic resonance imaging (MRI). Prospectively, 21 cervical carotid stenosis patients, mean age 69.95 years, underwent MRI 12 h before and 72 h after CAS. PWI parameters were collected for statistical analysis: cerebral blood volume (CB V), mean transit time (MTT) and time to peak (TTP). Statistical analysis was applied to absolute parameters and to values normalized against those from the contralateral parenchyma. The main finding of this study was improved hemodynamics for the normalized data after CAS, shown by reduced MTT (p<0.001) and TTP (p=0.019) in the territory fed by the middle cerebral artery ipsilateral to the CAS. Absolute data showed increased blood volume in the cerebral hemispheres after CAS, which was more accentuated on the stent side (p=0.016) than the contralateral side (p=0.029). Early improvements in cerebral perfusion, mainly seen in the normalized data, were clearly demonstrated in the timing parameters - TTP & MTT - after CAS.
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Purpose: The purpose of this study was to assess risk factors associated with the development of acute respiratory failure (ARF) and death in a general intensive care unit (ICU). Materials and Methods: Adults who were hospitalized at 12 surgical and nonsurgical ICUs were prospectively followed up. Multivariable analyses were realized to determine the risk factors for ARF and point out the prognostic factors for mortality in these patients. Results: A total of 1732 patients were evaluated, with an ARF prevalence of 57%. Of the 889 patients who were admitted without ARF, 141 (16%) developed this syndrome in the ICU. The independent risk factors for developing ARF were 64 years of age or older, longer time between hospital and ICU admission, unscheduled surgical or clinical reason for ICU admission, and severity of illness. Of the 984 patients with ARF, 475 (48%) died during the ICU stay. Independent prognostic factors for death were age older than 64 years, time between hospital and ICU admission of more than 4 days, history of hematologic malignancy or AIDS, the development of ARF in ICU, acute lung injury, and severity of illness. Conclusions: Acute respiratory failure represents a large percentage of all ICU patients, and the high mortality is related to some preventable factors such as the time to ICU admission. (C) 2011 Elsevier Inc. All rights reserved.
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Objective: Patients undergoing amputation of the lower limb due to peripheral arterial disease (PAD) are at risk of developing deep venous thrombosis (DVT). Few studies in the research literature report the incidence of DVT during the early postoperative period or the risk factors for the development of DVT in the amputation stump. This prospective study evaluated the incidence of DVT during the first 35 postoperative days in patients who had undergone amputation of the lower extremity due to PAD and its relation to comorbidities and death. Methods: Between September 2004 and March 2006, 56 patients (29 men), with a mean age of 67.25 years, underwent 62 amputations, comprising 36 below knee amputations (BKA) and 26 above knee amputations (AKA). Echo-Doppler scanning was performed preoperatively and on postoperative days 7 and 31 (approximately). All patients received acetylsalicylic acid (100 mg daily) preoperatively and postoperatively, but none received prophylactic anticoagulation. Results: DVT occurred in 25.8% of extremities with amputations (10 ARA and 6 BKA). The cumulative incidence in the 35-day postoperative period was 28% (Kaplan-Meier). There was a significant difference (P = .04) in the incidence of DVT between AKA (37.5%) and BKA (21.2%). Age >= 70 years (48.9% vs 16.8%, P = .021) was also a risk factor for DVT in the univariate analysis. Of the 16 cases, 14 (87.5%) were diagnosed during outpatient care. The time to discharge after amputation was averaged 6.11 days in-hospital stay (range, 1-56 days). One symptomatic nonfatal pulmonary embolism occurred in a patient already diagnosed with DVT. There was no relation between other comorbidities and DVT. The multivariate analysis showed no association between risk factors and the occurrence of DVT in the amputated extremity. DVT ipsilateral to the amputation did not influence the mortality rate (9.7%). Conclusion: The incidence of DVT in the early postoperative period (<= 35 days) was elevated principally in patients aged >= 70 years and for AKA. Patients with PAD who have recently undergone major amputations should be considered at high risk for DVT, even after hospital discharge. Given the high rate of postoperative DVT observed in this study, we now recommend prophylactic anticoagulation for these patients, but further study is needed to determine the optimal duration and efficacy of this treatment. (J Vasc Surg 2008;48:1514-9.)
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Prolonged infusions have been shown to be safer and potentially more effective than bolus regimens of 5-fluorouracil (5-FU) as treatment for metastatic colorectal cancer (mCRC). However, infusional 5-FU requires central venous access and costly infusion pumps. Oral fluoropyrimidines enable longer exposures to 5-FU with increased convenience. Tegafur - uracil (UFT) with leucovorin (LV) given thrice daily has improved safety plus comparable survival and response rates to bolus 5-FU/LV. We conducted a phase II clinical study in 98 patients with mCRC to evaluate if UFT with LV given twice daily provided comparable time to progression ( TTP), efficacy and tolerability to that reported for thrice daily in two phase III clinical studies. Secondary objectives included overall response rate ( ORR) and overall survival ( OS). Median TTP was 3.8 months, when compared with 3.5 months for thrice daily. The ORR ( 11%) and median OS ( 12.8 months) with twice daily administration were similar to that of thrice daily administration ( 12% and 12.4 months). The incidence of grade 3/4 treatment-related diarrhoea was 30% on the twice daily and 21% on the thrice daily schedule. These results suggest that twice daily administration has similar efficacy and tolerability to thrice daily administration and is an acceptable alternative for patients who would benefit from UFT with LV therapy.
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At present, there is a variety of formalisms for modeling and analyzing the communication behavior of components. Due to a tremendous increase in size and complexity of embedded systems accompanied by shorter time to market cycles and cost reduction, so called behavioral type systems become more and more important. This chapter presents an overview and a taxonomy of behavioral types. The intentions of this taxonomy are to provide a guidance for software engineers and to form the basis for future research.
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We have previously isolated a Lys49 phospholipase A(2) homolog (BaTX) from Bothrops alternatus snake venom using a combination of molecular exclusion chromatography and reverse phase HPLC and shown its ability to cause neuromuscular blockade. In this work, we describe a one-step procedure for the purification of this toxin and provide further details of its neuromuscular activity. The toxin was purified by reverse phase HPLC and its purity and molecular mass were confirmed by SIDS-PAGE, MALDI-TOF mass spectrometry, amino acid analysis and N-terminal sequencing. BaTX (0.007-1.4 mu M) produced time-dependent, irreversible neuromuscular blockade in isolated mouse phrenic nerve-diaphragm and chick biventer cervicis preparations (time to 50% blockade with 0.35 mu M toxin: 58 +/- 4 and 24 +/- 1 min, respectively; n = 3-8; mean +/- S.E.) without significantly affecting the response to direct muscle stimulation. In chick preparations, contractures to exogenous acetylcholine (55 and 110 mu M) or KCl (13.4 mM) were unaltered after complete blockade by all toxin concentrations. These results, which strongly suggested a presynaptic mechanism of action for this toxin, were reinforced by (1) the inability of BaTX to interfere with the carbachol-induced depolarization of the resting membrane, (2) a significant decrease in the frequency and amplitude of miniature end-plate potentials, and (3) a significant reduction (59 +/- 4%, n=12) in the quantal content of the end-plate potentials after a 60 min incubation with the toxin (1.4 mu M). In addition, a decrease in the organ bath temperature from 37 degrees C to 24 degrees C and/or the replacement of calcium with strontium prevented the neuromuscular blockade, indicating a temperature-dependent effect possibly mediated by enzymatic activity. (C) 2009 Elsevier Inc. All rights reserved.
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Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.
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Context Novel therapies have improved the remission rate in chronic inflammatory disorders including juvenile idiopathic arthritis (JIA). Therefore, strategies of tapering therapy and reliable parameters for detecting subclinical inflammation have now become challenging questions. Objectives To analyze whether longer methotrexate treatment during remission of JIA prevents flares after withdrawal of medication and whether specific biomarkers identify patients at risk for flares. Design, Setting, and Patients Prospective, open, multicenter, medication-withdrawal randomized clinical trial including 364 patients (median age, 11.0 years) with JIA recruited in 61 centers from 29 countries between February 2005 and June 2006. Patients were included at first confirmation of clinical remission while continuing medication. At the time of therapy withdrawal, levels of the phagocyte activation marker myeloid-related proteins 8 and 14 heterocomplex (MRP8/14) were determined. Intervention Patients were randomly assigned to continue with methotrexate therapy for either 6 months (group 1 [n = 183]) or 12 months (group 2 [n = 181]) after induction of disease remission. Main Outcome Measures Primary outcome was relapse rate in the 2 treatment groups; secondary outcome was time to relapse. In a prespecified cohort analysis, the prognostic accuracy of MRP8/14 concentrations for the risk of flares was assessed. Results Intention-to-treat analysis of the primary outcome revealed relapse within 24 months after the inclusion into the study in 98 of 183 patients (relapse rate, 56.7%) in group 1 and 94 of 181 (55.6%) in group 2. The odds ratio for group 1 vs group 2 was 1.02 (95% CI, 0.82-1.27; P=.86). The median relapse-free interval after inclusion was 21.0 months in group 1 and 23.0 months in group 2. The hazard ratio for group 1 vs group 2 was 1.07 (95% CI, 0.82-1.41; P=.61). Median follow-up duration after inclusion was 34.2 and 34.3 months in groups 1 and 2, respectively. Levels of MRP8/14 during remission were significantly higher in patients who subsequently developed flares (median, 715 [IQR, 320-1110] ng/mL) compared with patients maintaining stable remission (400 [IQR, 220-800] ng/mL; P=.003). Low MRP8/14 levels indicated a low risk of flares within the next 3 months following the biomarker test (area under the receiver operating characteristic curve, 0.76; 95% CI, 0.62-0.90). Conclusions In patients with JIA in remission, a 12-month vs 6-month withdrawal of methotrexate did not reduce the relapse rate. Higher MRP8/14 concentrations were associated with risk of relapse after discontinuing methotrexate.
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Background Occupational risk due to airborne disease challenges healthcare institutions. Environmental measures are effective but their cost-effectiveness is still debatable and most of the capacity planning is based on occupational rates. Better indices to plan and evaluate capacity are needed. Goal To evaluate the impact of installing an exclusively dedicated respiratory isolation room (EDRIR) in a tertiary emergency department (ED) determined by a time-to-reach-facility method. Methods A group of patients in need of respiratory isolation were first identified-group I (2004; 29 patients; 44.1 +/- 3.4 years) and the occupational rate and time intervals (arrival to diagnosis, diagnosis to respiratory isolation indication and indication to effective isolation) were determined and it was estimated that adding an EDRIR would have a significant impact over the time to isolation. After implementing the EDRIR, a second group of patients was gathered in the same period of the year-group II (2007; 50 patients; 43.4 +/- 1.8 years) and demographic and functional parameters were recorded to evaluate time to isolation. Cox proportional hazard models adjusted for age, gender and inhospital respiratory isolation room availability were obtained. Results Implementing an EDRIR decreased the time from arrival to indication of respiratory isolation (27.5 +/- 9.3 X 3.7 +/- 2.0; p = 0.0180) and from indication to effective respiratory isolation (13.3 +/- 3.0 X 2.94 +/- 1.06; p = 0.003) but not the respiratory isolation duration and total hospital stay. The impact on crude isolation rates was very significant (8.9 X 75.4/100.000 patients; p < 0.001). The HR for effective respiratory isolation was 26.8 (95% CI 7.42 to 96.9) p < 0.001 greater for 2007. Conclusion Implementing an EDRIR in a tertiary ED significantly reduced the time to respiratory isolation.
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This Study reports a case of parasitism by the giant kidney worm, Dioctophyma renale, diagnosed in the right kidney of a domestic (log An adult female German Shepherd was attended with clinical history of prostration and hyporexia. The hemogram showed changes compatible with an inflammatory process, for that reason, an abdominal ultrasound was requested. Ultrasound image suggested the presence of D renale in the right kidney The diagnosis was confirmed after urinalysis due to the presence of dioclophymas ova in the urinary sediment. Surgical treatment was made and the animal had an excellent recovery after the nephrectomy was performed Generally. in almost all cases, parasitism by D renale in domestic dogs is a necropsy finding, nevertheless imaging techniques as sonography and laboratorial exams as urinalysis have been proven to be important tools to achieve diagnosis. The purpose of this study is to report a case of parasitism by D renale where diagnosis and treatment were made in time to allow the patient`s recovery (C) 2009 Elsevier B V All rights reserved.
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Background/Aims: Antidepressants are reported to exhibit antiinflammatory effects. However, mechanisms involved in this action have not been elucidated. Thus, the objectives of the present study were (a) to evaluate the effects of amitriptyline on the acute inflammatory process, and (b) to investigate the participation of alpha(1)-adrenergic receptors and glucocorticoids as possible mechanisms implicated in the amitriptyline action on inflammation. Methods and Results: Single and multiple doses of amitriptyline were administered to rats submitted to the carrageenan-induced paw edema model. The results showed a significant antiedematous reaction to amitriptyline, mainly when administered at each elimination half-life. The next step was to evaluate its effects on leukocyte behavior, using intravital microscopy. Amitriptyline produced a significant effect on leukocyte behavior. To investigate possible mechanisms involved, a glucocorticoid receptor antagonist (RU-486) and an alpha(1)-adrenergic receptor antagonist (prazosin) were used. RU-486 administration lacked the ability to decrease the amitriptyline antiinflammatory effects in the carrageenan-induced paw edema model. Prazosin pretreatment potentiated the amitriptyline antiinflammatory effect without presenting an effect per se. Conclusion:The present study shows the ability of amitriptyline to decrease edema and affect leukocyte behavior in an acute inflammatory process; and, for the first time to our knowledge, we suggest the involvement of alpha(1)-adrenoceptors in the antiinflammatory effects of amitriptyline. Copyright (C) 2010 S. Karger AG, Basel
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This study evaluated whether the four gonadorelin products that are commercially available in the United States produce comparable ovulation responses in lactating cows. Dairy cows at 7 d after last gonadotropin-releasing hormone (GnRH) treatment of Ovsynch (Day 7), with a corpus luteum (CL) >= 15 mm and at least one follicle >= 10 mm, were evaluated for response to GnRH treatment. Selected cows were randomized to receive (100 mu g; im): (1) Cystorelin (n = 146): (2) Factrel (n = 132): (3) Fertagyl (n = 140); or (4) Ovacyst (n = 140). On Day 14, cows were examined for Ovulation by detection of an accessory CL. Circulating luteinizing hormone (LH) concentrations were also evaluated in some cows after treatment with 100 mu g (n = 10 per group) or 50 mu g (n = 5 per group) GnRH. Statistical analyses were performed with the procedures MIXED and GLIMMIX of the SAS program. Percentage of cows ovulating differed (P < 0.01) among groups, with that for Factrel being lower (55.3%) than that for Cystorelin (76.7%), Fertagyl (73.6%), or Ovacyst (85.0%), There was no effect of batch, parity, or follicle size on ovulation response. but increasing body condition score decreased Ovulation response. There was a much greater LH release in cows treated with 100 mu g than in those treated with 50 mu g, but there were no detectable differences among products in time to LH peak, peak LH concentration, or area under the LH curve and no treatment effects nor treatment by time interactions on circulating LH profile. Thus, ovulation response to Factrel on Day 7 of the cycle was lower than that for other commercial GnRH products, although a definitive mechanism for this difference between products was not demonstrated. (C) 2009 Elsevier Inc. All rights reserved.
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Purpose: Orthodontic miniscrews are commonly used to achieve absolute anchorage during tooth movement. One of the most frequent complications is screw loss as a result of root contact. Increased precision during the process of miniscrew insertion would help prevent screw loss and potential root damage, improving treatment outcomes. Stereo lithographic surgical guides have been commonly used for prosthetic implants to increase the precision of insertion. The objective of this paper was to describe the use of a stereolithographic surgical guide suitable for one-component orthodontic miniscrews based on cone beam computed tomography (CBCT) data and to evaluate implant placement accuracy. Materials and Methods: Acrylic splints were adapted to the dental arches of four patients, and six radiopaque reference points were filled with gutta-percha. The patients were submitted to CBCT while they wore the occlusal splint. Another series of images was captured with the splint alone. After superimposition and segmentation, miniscrew insertion was simulated using planning software that allowed the user to check the implant position in all planes and in three dimensions. In a rapid-prototyping machine, a stereolithographic guide was fabricated with metallic sleeves located at the insertion points to allow for three-dimensional control of the pilot bur. The surgical guide was worn during surgery. After implant insertion, each patient was submitted to CBCT a second time to verify the implant position and the accuracy of the placement of the miniscrews. Results: The average differences between the planned and inserted positions for the ten miniscrews were 0.86 mm at the coronal end, 0.71 mm at the center, and 0.87 mm at the apical tip. The average angular discrepancy was 1.76 degrees. Conclusions: The use of stereolithographic surgical guides based on CBCT data allows for accurate orthodontic mini screw insertion without damaging neighboring anatomic structures. INT J ORAL MAXILLOFAC IMPLANTS 2011;26:860-865
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Fluoride in drinking water may be present from natural sources or added as sodium fluoride (NaF), sodium silicofluoride (Na2SiF6) or fluorosilicic acid (H2SiF6). Results from an early study with rats suggested that, when ingested as Na2SiF6, the absorption and excretion of fluoride were greater than when ingested as NaF. Objective: The present single-blind, crossover study with 10 adults was done to determine three key pharmacokinetic parameters: the maximum plasma fluoride concentrations (C-max), the elapsed time to reach the maximum concentrations (T-max) and the 6-h areas under the time-plasma concentration curves (AUCs) after ingestion of 500 ml, of water containing 0.67 or 5.45 mg F/L present naturally or added as NaF or H2SiF6. Design: Blood was collected prior to and at nine time points during 6 h after ingestion of the test solutions. Plasma was analysed by electrode after HMDS-facilitated diffusion and the data were analysed for statistically significant differences using repeated measures ANOVA. Results: The C-max, T-max and AUC values after ingestion of the solutions containing natural fluoride, NaF or H2SiF6 did not differ significantly at either dose level. Further, the Tmax values associated with the 0.67 and SAS mg/L solutions did not differ significantly indicating that the absorption, distribution and elimination rates were not affected by the dose size. Conclusions: Considered together with published reports, the present findings support the conclusion that the major features of fluoride metabolism are not affected differently by the chemical compounds commonly used to fluoridate water nor are they affected by whether the fluoride is present naturally or added artificially. (C) 2008 Elsevier Ltd. All rights reserved.
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Introduction: In this double-blind and randomized controlled trial, we analyzed whether a lower concentration of chlorhexidine in dentifrices could reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis, bleeding, and dental plaque. Methods: Volunteers with fixed orthodontic appliances were randomly divided into 3 groups: control, 1100 ppm F, NaF (n = 27); experimental, chlorhexidine 0.50% (n = 27); and experimental, chlorhexidine 0.75% (n = 27). At baseline, and after 6 and 12 weeks, clinical examinations were carried out. Staining, calculus, gingivitis, bleeding, and dental plaque data were analyzed with Friedman tests to evaluate intragroup changes over time. To detect intergroup differences after 12 months, the data were evaluated with Kruskal-Wallis tests. Dunn tests were used in both situations for necessary post-hoc analyses. Results: The groups were statistically similar for the stain, calculus, and plaque indexes, but there were statistically significant differences for the gingival and bleeding indexes. During the experimental periods, gingivitis and bleeding scores improved in all 3 groups. Only the 0.75% chlorhexidine dentifrice significantly increased the stain index, although most patients did not notice the stains. The intergroup comparison showed a statistically significant better performance of the experimental groups regarding the gingival and bleeding indexes. Conclusions: This study suggests that the use of dentifrices with lower concentration of chlorhexidine can reduce the risk of tooth staining without compromising its effectiveness in controlling gingivitis and bleeding in orthodontic patients. (Am J Orthod Dentofacial Orthop 2009; 136: 651-6)