460 research outputs found
The accuracy of 99mTc-DTPA scintigraphy in the evaluation of acute renal graft complications
PURPOSE: Renal scintigraphy has been used for many years in the evaluation of renal transplants and can help in the diagnosis of graft complications, leading to prompt clinical management and preventing further deterioration of renal function. The purpose of this study was to evaluate the overall accuracy of renal scintigraphy with 99mTc-DTPA in the diagnosis of acute renal graft complications. MATERIALS AND METHODS: Seventy-six scintigraphic studies performed in 55 patients (ages ranging from 6 to 65 years), were reviewed. Scintigraphy results were compared to biopsies performed within 5 days of imaging. 99mTc-DTPA study was performed within a mean time of 19 days after kidney transplants. Dynamic images were performed in the anterior position of the abdomen and pelvis every 2 seconds for 80 seconds (flow phase) and every 15 seconds for 30 minutes (functional phase), after an intravenous injection of 370 MBq (10 mCi) of 99mTc-DTPA. RESULTS: The scintigraphic results were concordant with the biopsies in 86% of the cases studied. The sensitivities of renal scintigraphy for detection of acute tubular necrosis (ATN), acute rejection (AR) and cortical necrosis (CN) were 98%, 87% and 100%, respectively. Specificities and accuracies for detection of ATN, AR and CN were 89%, 86% and 100%, and 95%, 87% and 100%, respectively. CONCLUSION: Renal scintigraphy with 99mTc-DTPA showed a good overall accuracy in the detection of acute renal graft complications. It can be used as a reliable tool in the routine evaluation of these patients50751
Is Thyroid Stunning Clinically Relevant? A Retrospective Analysis Of 208 Patients.
Current guidelines have advised against the performance of (131)I-iodide diagnostic whole body scintigraphy (dxWBS) to minimize the occurrence of stunning, and to guarantee the efficiency of radioiodine therapy (RIT). The aim of the study was to evaluate the impact of stunning on the efficacy of RIT and disease outcome. This retrospective analysis included 208 patients with differentiated thyroid cancer managed according to a same protocol and followed up for 12-159 months (mean 30 ± 69 months). Patients received RIT in doses ranging from 3,700 to 11,100 MBq (100 mCi to 300 mCi). Post-RIT-whole body scintigraphy images were performed 10 days after RIT in all patients. In addition, images were also performed 24-48 hours after therapy in 22 patients. Outcome was classified as no evidence of disease (NED), stable disease (SD) and progressive disease (PD). Thyroid stunning occurred in 40 patients (19.2%), including 26 patients with NED and 14 patients with SD. A multivariate analysis showed no association between disease outcome and the occurrence of stunning (p = 0.3476). The efficacy of RIT and disease outcome do not seem to be related to thyroid stunning.58292-30
Optimal transfers from Moon to halo orbit of the Earth-Moon system
In this paper, we seek optimal solutions for a transfer from a parking orbit
around the Moon to a halo orbit around of the Earth-Moon system, by
applying a single maneuver and exploiting the stable invariant manifold of the
hyperbolic parking solution at arrival. For that, we propose an optimization
problem considering as variables both the orbital characteristics of a parking
solution around the Moon, (namely, its Keplerian elements) and the
characteristics of a transfer trajectory guided by the stable manifold of the
arrival Halo orbit. The problem is solved by a nonlinear programming method
(NLP), aiming to minimize the cost of to perform a single maneuver
transfer, within the framework of the Earth-Moon system of the circular
restricted three-body problem. Results with low and suitable time of
flight show the feasibility of this kind of transfer for a Cubesat
Numerical investigations of the orbital dynamics around a synchronous binary system of asteroids
In this article, equilibrium points and families of periodic orbits in the
vicinity of the collinear equilibrium points of a binary asteroid system are
investigated with respect to the angular velocity of the secondary body, the
mass ratio of the system and the size of the secondary. We assume that the
gravitational fields of the bodies are modeled assuming the primary as a mass
point and the secondary as a rotating mass dipole. This model allows to compute
families of planar and halo periodic orbits that emanate from the equilibrium
points and . The stability and bifurcations of these families are
analyzed and the results are compared with the results obtained with the
Restricted Three-Body Problem (RTBP). The results provide an overview of the
dynamical behavior in the vicinity of a binary asteroid system
The Accuracy Of (99m)tc-dtpa Scintigraphy In The Evaluation Of Acute Renal Graft Complications.
Renal scintigraphy has been used for many years in the evaluation of renal transplants and can help in the diagnosis of graft complications, leading to prompt clinical management and preventing further deterioration of renal function. The purpose of this study was to evaluate the overall accuracy of renal scintigraphy with (99m)Tc-DTPA in the diagnosis of acute renal graft complications. Seventy-six scintigraphic studies performed in 55 patients (ages ranging from 6 to 65 years), were reviewed. Scintigraphy results were compared to biopsies performed within 5 days of imaging. (99m)Tc-DTPA study was performed within a mean time of 19 days after kidney transplants. Dynamic images were performed in the anterior position of the abdomen and pelvis every 2 seconds for 80 seconds (flow phase) and every 15 seconds for 30 minutes (functional phase), after an intravenous injection of 370 MBq (10 mCi) of (99m)Tc-DTPA. The scintigraphic results were concordant with the biopsies in 86% of the cases studied. The sensitivities of renal scintigraphy for detection of acute tubular necrosis (ATN), acute rejection (AR) and cortical necrosis (CN) were 98%, 87% and 100%, respectively. Specificities and accuracies for detection of ATN, AR and CN were 89%, 86% and 100%, and 95%, 87% and 100%, respectively. Renal scintigraphy with (99m)Tc-DTPA showed a good overall accuracy in the detection of acute renal graft complications. It can be used as a reliable tool in the routine evaluation of these patients.29507-1
Effect of hydrogen peroxide on natural phytoplankton and bacterioplankton in a drinking water reservoir: mesocosm-scale study.
Cyanobacterial blooms are increasingly reported worldwide, presenting a challenge to water treatment plants and concerning risks to human health and aquatic ecosystems. Advanced oxidative processes comprise efficient and safe methods for water treatment. Hydrogen peroxide (H2O2) has been proposed as a sustainable solution to mitigate bloom-forming cyanobacteria since this group presents a higher sensitivity compared to other phytoplankton, with no major risks to the environment at low concentrations. Here, we evaluated the effects of a single H2O2 addition (10 mg Lâ1) over 120 h in mesocosms introduced in a reservoir located in a semi-arid region presenting a Planktothrix-dominated cyanobacterial bloom. We followed changes in physical and chemical parameters and in the bacterioplankton composition. H2O2 efficiently suppressed cyanobacteria, green algae, and diatoms over 72 h, leading to an increase in transparency and dissolved organic carbon, and a decrease in dissolved oxygen and pH, while nutrient concentrations were not affected. After 120 h, cyanobacterial abundance remained low and green algae became dominant. 16S rRNA sequencing revealed that the original cyanobacterial bloom was composed by Planktothrix, Cyanobium and Microcystis. Only Cyanobium increased in relative abundance at 120 h, suggesting regrowth. A prominent change in the composition of heterotrophic bacteria was observed with Exiguobacterium, Paracoccus and Deinococcus becoming the most abundant genera after the H2O2 treatment. Our results indicate that this approach is efficient in suppressing cyanobacterial blooms and improving water quality in tropical environments. Monitoring changes in abiotic parameters and the relative abundance of specific bacterial taxa could be used to anticipate the regrowth of cyanobacteria after H2O2 degradation and to indicate where in the reservoir H2O2 should be applied so the effects are still felt in the water treatment plant intake
Doses cumulativas de iodo radioativo no tratamento do carcinoma diferenciado de tireoide: sabendo a hora de parar
OBJECTIVE: Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). SUBJECTS AND METHODS: The probability of progressive disease according to CDs was evaluated in patients < 45 years old and > 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. RESULTS: At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p < 0.0001), higher TNM stages (p < 0.0001), and follicular carcinomas (p = 0.0034). Probability of disease progression was higher with CDs > 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. CONCLUSION: Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.OBJETIVO: Avaliar a eficĂĄcia de doses cumulativas (DCs) da terapia com iodeto-131I (RIT) no cĂąncer diferenciado de tiroide (CDT). SUJEITOS E MĂTODOS: A probabilidade de doença em progressĂŁo conforme a DC foi calculada em pacientes com idade < 45 e > 45 anos e correlacionada com o TNM, valores de tiroglobulina sĂ©rica, tipos histolĂłgicos e variantes, idade e tempo de doença. RESULTADOS: Ao final de um seguimento de 69 ± 56 meses, 85 dos 150 pacientes CDT submetidos a doses fixas de RIT nĂŁo tinham evidĂȘncia de doença, 47 tinham doença estĂĄvel e 18, doença progressiva. DCs mais elevadas foram usadas nas variantes agressivas (p < 0,0001), maior estĂĄgio TNM (p < 0,0001) e nos carcinomas foliculares (p = 0,0034). A probabilidade de doença em progressĂŁo foi maior com DCs > 600 mCi em pacientes > 45 anos e com DCs > 800 mCi em pacientes < 45 anos. CONCLUSĂO: Apesar de alguns pacientes ainda responderem a altas DCs, o impacto de RITs deve ser cuidadosamente avaliado e outras estratĂ©gias terapĂȘuticas devem ser consideradas.80781
Cumulative Doses Of Radioiodine In The Treatment Of Differentiated Thyroid Carcinoma: Knowing When To Stop.
Evaluate the efficacy of cumulative doses (CDs) of 131I-iodide therapy (RIT) in differentiated thyroid cancer (DTC). The probability of progressive disease according to CDs was evaluated in patients 45 years old and correlated to tumor-node-metastasis (TNM), thyroglobulin values, histological types and variants, age, and zduration of the disease. At the end of a follow-up period of 69 ± 56 months, 85 out of 150 DTC patients submitted to fixed doses RIT had no evidence of disease, 47 had stable disease and 18 had progressive disease. Higher CDs were used in the more aggressive variants (p 600 mCi in patients > 45 years old and with CDs > 800 mCi in patients < 45 years. Although some patients may still respond to high CDs, the impact of further RIT should be carefully evaluated and other treatment strategies may be warranted.54807-1
Assessment of Bone Mineral Density of Patients with Spinocerebellar Ataxia Type 3
Objective Machado-Joseph disease (MJD) is a spinocerebellar ataxia, and osteoporosis is a multifactor disease that may affect patients with neurologic conditions. The frequency of osteoporosis among MJD patients, however, has not been studied. The purpose of this study is to evaluate bone mineral density (BMD) and identify correlations between clinical factors and frequency of vertebral fractures in patients with MJD. Methods Clinical data, lumbar X-rays and BMD data were obtained in 30 patients with MJD. Results Ten patients (33.3%) showed low BMD in at least one of the sites studied based on Z-scores. The Z-score correlated directly with body mass index, and the femoral neck Z-score was inversely correlated with cytosine-adenine-guanine (CAG) expansion. There was no correlation between BMD and other clinical factors. Forty-three percent of the patients reported previous pathologic fractures. Five patients (16.7%) had at least one fracture detected by lumbar X-ray. Conclusion Low BMD and fractures are frequent among MJD patients, and careful management of BMD may be beneficial for these patients
Cymbopogon winterianus essential oil attenuates bleomycin-induced pulmonary fibrosis in a murine model
The essential oil of Cymbopogon winterianus (EOCW) is a natural product with antioxidant, anti-inflammatory, and antifibrotic properties. We studied the effect of EOCW in the progression of histological changes of pulmonary fibrosis (PF) in a rodent model. The oil was obtained by hydrodistillation and characterized using gas chromatographymass spectrometry. Intratracheal instillation of bleomycin was performed in 30 rats to induce PF, while Sham animals were subjected to instillation of saline solution. The treatment was performed using daily oral administration of distilled water, EOCW at 50, 100, and 200 mg/kg, and deflazacort (DFC). After 28 days, hemogram and bronchoalveolar lavage fluid (BALF), tissue levels of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) were assayed. Histological grading of PF, immunohistochemical expression of -smooth muscle actin (-SMA), and transforming growth factor- (TGF-) were also analyzed. The EOCW major compounds were found to be citronellal, geraniol, and citronellol. EOCW significantly reduced inflammation in BALF, reduced MDA levels, and increased SOD activity. EOCW attenuated histological grading of PF and reduced immunohistochemical expression of -SMA and TGF- in a dose-dependent way, likely due to the reduction of oxidative stress, inflammation, and TGF--induced myofibroblast differentiation.This research was financed by the Coordenação Aperfeiçoamento de Pessoal de Nivel
Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de Sergipe (FAPITEC), and Conselho
Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq). EBS wishes to acknowledge the
sponsorship of the project UIDB/04469/2020 (strategic fund) from the Portuguese Science and
Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and
was co-financed by FEDER, under the Partnership Agreement PT2020.info:eu-repo/semantics/publishedVersio
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