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1.
Phys Rev Lett ; 125(19): 191801, 2020 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33216576

RESUMO

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5 eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002 eV^{2} using the ν[over ¯]_{e} disappearance channel.

2.
Phys Rev Lett ; 122(23): 232501, 2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31298906

RESUMO

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43} cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43} cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43} cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

3.
Phys Rev Lett ; 121(20): 201801, 2018 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-30500262

RESUMO

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3} eV^{2}.

4.
Br J Cancer ; 109(4): 1072-8, 2013 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-23867999

RESUMO

BACKGROUND: We tested the hypothesis that BRCA1/2 mutation carriers with ovarian cancer are at higher risk of carboplatin hypersensitivity reactions (HSRs). METHODS: Medical records of women enrolled in two carboplatin+olaparib clinical trials (NCT01237067/NCT01445418) were reviewed. A maximum of eight cycles containing carboplatin were administered. RESULTS: All women (N=87) had good performance status and end-organ function. Incidences of carboplatin HSR before enrolment and on study were 17% and 21%, respectively. Most patients who developed carboplatin HSR had a deleterious BRCA1/2 mutation (93%) vs 50% in patients without HSR (P<0.0001). Multivariable analysis accounting for potential confounding variables including age, history of allergies, and cumulative prior carboplatin cycles confirmed deleterious BRCA1/2 mutation as an independent risk factor for carboplatin HSR (odds ratio 13.1 (95% confidence interval 2.6-65.4), P=0.0017). Mutation carriers had onset of carboplatin HSR at lower cumulative exposure (P=0.003). No significant difference in outcome was observed on our study between patients with and without a history of HSR. CONCLUSION: Deleterious BRCA1/2 mutation increased susceptibility and shortened time to carboplatin HSR, independently of other reported factors. These data suggest that at-risk women should be counselled regarding likelihood, symptoms, and potential earlier onset of carboplatin HSRs.


Assuntos
Antineoplásicos/efeitos adversos , Carboplatina/efeitos adversos , Hipersensibilidade a Drogas/genética , Genes BRCA1 , Genes BRCA2 , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carboplatina/administração & dosagem , Carcinoma/tratamento farmacológico , Carcinoma/genética , Hipersensibilidade a Drogas/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Razão de Chances , Neoplasias Ovarianas/genética , Ftalazinas/administração & dosagem , Piperazinas/administração & dosagem , Estudos Retrospectivos , Fatores de Risco
5.
Eur J Surg Oncol ; 43(2): 471-477, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27912930

RESUMO

BACKGROUND: The purpose of this study was to analyze the risk factors of recurrence in patients with early stage esophageal squamous cell carcinoma (ESCC). METHODS: We retrospectively analyzed the medical records of 190 patients with confirmed T1N0M0 ESCC after curative esophagectomy. The following potential prognostic factors for recurrence were investigated: age, sex, pathologic T category, tumor location, differentiation grade, tumor size, venous invasion, angiolymphatic invasion, perineural invasion and the maximum standardized uptake value (SUVmax) of the primary tumor. RESULTS: There were 174 male and 16 female patients with a median age of 66.0 years (range, 42.0-79.0 years). The pathologic status of the surgically resected ESCCs was T1a in 93 patients (48.9%) and T1b in 97 patients (51.1%). The median number of dissected lymph nodes was 35 (range, 10 to 86), and all lymph nodes were negative for tumors. The multivariate analysis showed presence of venous invasion [HR (hazard ratio), 11.433; P < 0.001) and SUVmax ≥ 3.2 (HR, 2.830; P = 0.011) as independent risk factors for recurrence. The 5-year recurrence-free survival (RFS) was 25.0% for patients with venous invasion and 78.9% for those without (P < 0.001). The 5-year RFS was 67.1% for patients with an SUVmax ≥3.2 and 81.5% for those with an SUVmax <3.2 (P = 0.003). CONCLUSIONS: Venous invasion and high SUVmax could be important prognostic factors coupled with the TNM staging system, in patients with early stage ESCC.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Esofagectomia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias Vasculares/diagnóstico por imagem , Neoplasias Vasculares/secundário , Adulto , Idoso , Feminino , Fluordesoxiglucose F18 , Humanos , Excisão de Linfonodo , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Compostos Radiofarmacêuticos , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
6.
J Am Coll Cardiol ; 33(5): 1328-37, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10193735

RESUMO

OBJECTIVES: The purpose of this study was to evaluate the predictive accuracy of positron emission tomography (PET) blood flow-F-18 fluorodeoxyglucose (FDG) imaging in coronary artery disease (CAD) patients with diabetes mellitus (DM). BACKGROUND: Positron emission tomography accurately predicts the postrevascularization improvement in left ventricular dysfunction in unselected patients with CAD. In diabetic patients, however, poor myocardial glucose utilization may limit the accuracy of the approach. METHODS: Forty patients (64+/-10 years old; 19 with DM = group I; 21 without DM = group II) with reduced left ventricular ejection fraction (LVEF = 29+/-6%) were studied with N-13 ammonia and FDG PET before coronary revascularization. Studies were performed after intravenous injection of regular insulin (group I) or oral glucose administration (group II). Blood flow-FDG mismatches and matches were identified by polar map analysis in the three vascular territories of the left anterior descending, left circumflex and right coronary artery. Wall motion and LVEF were assessed by two-dimensional echocardiography before and 158+/-123 days after revascularization. RESULTS: Of 107 vascular territories analyzed, 46 were classified as mismatch, 29 as match and 32 as normal. The FDG image quality, assessed by F-18 myocardium to blood pool activity ratios, and the predictive accuracy were similar in both groups; presence of a blood flow/FDG mismatch had a sensitivity of 92% (group I) and 94% (group II) and a specificity of 85% (group I) and 79% (group II) for an improvement in regional left ventricular function. A postrevascularization improvement in global left ventricular function was related to the extent of blood flow/FDG mismatch; LVEF increased from 30+/-7% to 35+/-7% (p = 0.017) in patients with one mismatch and from 27+/-4% to 41+/-7% (p < 0.001) in those with two mismatches. CONCLUSIONS: The predictive accuracy of blood flow/FDG imaging is maintained in patients with DM when a clinically acceptable study protocol, which guarantees good FDG image quality, is used. The extent of a blood flow/metabolism mismatch is correlated with the magnitude of the postrevascularization improvement in global left ventricular function.


Assuntos
Doença das Coronárias/diagnóstico por imagem , Diabetes Mellitus/diagnóstico por imagem , Fluordesoxiglucose F18 , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão/métodos , Disfunção Ventricular Esquerda/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Glicemia/metabolismo , Circulação Coronária , Doença das Coronárias/fisiopatologia , Diabetes Mellitus/fisiopatologia , Ecocardiografia , Feminino , Seguimentos , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Insulina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Revascularização Miocárdica , Prognóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Disfunção Ventricular Esquerda/fisiopatologia
7.
J Am Coll Cardiol ; 38(3): 631-7, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11527608

RESUMO

OBJECTIVES: This study was done to evaluate the feasibility and efficacy of beta-radiation therapy with a rhenium-188-mercaptoacetyltriglycine ((188)Re-MAG(3))-filled balloon after rotational atherectomy for diffuse in-stent restenosis (ISR). BACKGROUND: Rotational atherectomy has been shown to be safe and efficient for the treatment of ISR, but the recurrence rate is still high. Intracoronary beta-irradiation after rotational atherectomy may be a reasonable approach to prevent recurrent ISR. METHODS: Fifty consecutive patients with diffuse ISR (length >10 mm) in native coronary arteries underwent rotational atherectomy and adjunctive balloon angioplasty, followed by beta-irradiation using a (188)Re-MAG(3)-filled balloon catheter. The radiation dose was 15 Gy at a depth of 1.0 mm into the vessel wall. RESULTS: The mean lengths of the lesion and irradiated segment were 25.6 +/- 12.7 mm and 37.6 +/- 11.2 mm, respectively. Radiation was delivered successfully to all patients, with a mean irradiation time of 201.8 +/- 61.7 s. No adverse event, including myocardial infarction, death or stent thrombosis, occurred during the follow-up period (mean 10.3 +/- 3.7 months), and nontarget vessel revascularization was needed in one patient. The six-month binary angiographic restenosis rate was 10.4%, and the loss index was 0.17 +/- 0.31. CONCLUSIONS: Beta-irradiation using a (188)Re-MAG(3)-filled balloon after rotational atherectomy is safe and feasible in patients with diffuse ISR, and it may improve their clinical and angiographic outcomes. Further prospective, randomized trials are warranted to evaluate the synergistic effect of debulking and irradiation in patients with diffuse ISR.


Assuntos
Aterectomia Coronária , Doença das Coronárias/radioterapia , Doença das Coronárias/cirurgia , Oligopeptídeos/uso terapêutico , Compostos Organometálicos/uso terapêutico , Compostos Radiofarmacêuticos/uso terapêutico , Stents , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Estudos de Viabilidade , Humanos , Oligopeptídeos/administração & dosagem , Compostos Organometálicos/administração & dosagem , Estudos Prospectivos , Compostos Radiofarmacêuticos/administração & dosagem , Recidiva , Resultado do Tratamento , Ultrassonografia de Intervenção
8.
J Nucl Med ; 41(11): 1836-41, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11079491

RESUMO

UNLABELLED: Although carotid shunting is occasionally necessary to prevent cerebral ischemia during carotid endarterectomy, there is no reliable indication for this procedure. The purpose of this study was to evaluate whether acetazolamide stress brain-perfusion SPECT can predict the need for carotid shunting during carotid endarterectomy. METHODS: Basal and acetazolamide stress brain-perfusion SPECT imaging was performed using a 1-d protocol and 99mTc-ethylcysteinate dimer (ECD) in 75 patients (12 women, 63 men; mean age, 64.8 y) before carotid endarterectomy. The need for carotid shunting during carotid endarterectomy was determined by the development of neurologic deterioration after carotid clamping under regional anesthesia. Regional cerebral blood flow, cerebrovascular reserve, the presence of contralateral carotid stenosis (> or =70%), and clinical risk factors, including age, sex, history of minor stroke or transient ischemic attack, diabetes mellitus, hypertension, and smoking, were assessed with regard to whether they could predict the need for shunting. RESULTS: Carotid endarterectomy was performed safely without carotid shunting in 61 of 75 patients (81.3%). Carotid shunting was required in 14 patients (18.7%). Seven of 21 patients with a contralateral carotid stenosis, 9 of 41 with a reduced regional cerebral blood flow, and 11 of 30 with a reduced regional cerebrovascular reserve underwent carotid shunting. Patients with a reduced cerebrovascular reserve had a significantly higher number of carotid shunts performed (P < 0.01) than did those with a normal reserve, whereas contralateral carotid stenosis (P = 0.054) showed borderline significance. Reduced cerebral blood flow and clinical risk factors did not predict the need for carotid shunting (P > 0.1). Multiple logistic regression analysis showed that reduced cerebrovascular reserve was the only reliable predictor of the need for carotid shunting (P < 0.01). When a severely reduced cerebrovascular reserve (8/8) or reduced cerebral blood flow and cerebrovascular reserve with contralateral carotid stenosis (6/7) were present, carotid shunting was necessary, with positive and negative predictive values of 91% (10/11) and 94% (60/64), respectively. CONCLUSION: A reduced cerebrovascular reserve can predict the development of cerebral ischemia during carotid clamping. Acetazolamide stress brain-perfusion SPECT may be useful as a complementary method in determining selective carotid shunting during carotid endarterectomy.


Assuntos
Acetazolamida , Encéfalo/diagnóstico por imagem , Circulação Cerebrovascular , Cisteína/análogos & derivados , Endarterectomia das Carótidas , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/etiologia , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Endarterectomia das Carótidas/efeitos adversos , Endarterectomia das Carótidas/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Compostos de Organotecnécio , Valor Preditivo dos Testes
9.
J Nucl Med ; 39(3): 431-5, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9529287

RESUMO

UNLABELLED: This study assessed the diagnostic accuracy of whole-body PET on a patient and lesion basis using 18F-fluorodeoxyglucose (FDG) for the detection of tumor foci in patients with suspected recurrent or metastatic lesions of breast carcinoma. METHODS: Whole-body FDG-PET imaging was performed on 57 patients with a previous history of breast carcinoma who were referred for a clinical suspicion of disease recurrence. Whole-body PET images were scored from 1 (definitely negative) to 5 (definitely positive) by three independent observers, and discrepancies were resolved by a fourth observer. Patients were clinically followed for up to 24 mo to assess the accuracy of PET diagnosis by biopsy, follow-up imaging and other diagnostic tests. RESULTS: PET scans showed that there were 41 sites indicating recurrent or metastatic disease in 29 patients. There were 38 sites in 28 patients that showed no evidence for malignant disease. On a patient basis, with scores 4 or 5 considered to be positive, sensitivity and specificity were 93% and 79%, respectively. The corresponding positive and negative predictive values were 82% and 92%. On a lesion basis, with scores 4 or 5 considered to be positive, the sensitivity was 85% and specificity 79%. The area index in receiver operating characteristic analysis was 0.91 for patient-based analysis and 0.88 for lesion-based analysis. To determine the cause for false-negative and false-positive findings more precisely, false-negative lesions with scores of 3 or lower and false-positive lesions with scores of 4 or higher were analyzed. Bone metastases had a significantly larger proportion of false-negative lesions than other nonosseous malignant sites (p < 0.05). False-positive lesions were due to muscle uptake (n = 5), inflammation (n = 4), blood pool activity in the great vessels (n = 2), bowel uptake (n = 1) and unknown causes (n = 6). CONCLUSION: The whole-body FDG-PET scan is a useful diagnostic test for detecting recurrent or metastatic lesions of breast carcinoma. However, the sensitivity for metastases to bone appears to be lower than that to other organs. Specificity may be improved by more strict attention to patient preparation and better recognition of physiologic skeletal muscle or artifactual uptakes.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Radioisótopos de Flúor , Fluordesoxiglucose F18 , Recidiva Local de Neoplasia/diagnóstico por imagem , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão , Neoplasias Ósseas/diagnóstico por imagem , Neoplasias Ósseas/epidemiologia , Neoplasias Ósseas/secundário , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade
10.
J Nucl Med ; 38(11): 1703-11, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9374337

RESUMO

UNLABELLED: Iodine-123-N-(3-iodopropene-2-yl)-2beta-carbomethoxy-3beta-( 4-chlorophenyl) tropane (123I-IPT) is a new dopamine transporter ligand that selectively binds the dopamine reuptake sites. Transporter concentrations have been known to decrease in Parkinson's disease patients. The purpose of this study was to evaluate the usefulness of IPT as an imaging agent for measuring changes in transporter concentrations in Parkinson's disease. METHODS: IPT labeled with 6.78 +/- 0.67 mCi 123I was injected intravenously as a bolus into eight normal controls (mean age 41 +/- 12 yr) and 17 Parkinson's disease patients (mean age 55 +/- 9 yr). Dynamic SPECT scans of the brain were then performed for 5 min each over 120 min on a triple-headed gamma camera equipped with medium-energy collimators. Regions of interest were drawn on the middle set of the image at the level of the basal ganglia (BG) for each subject. Time-activity curves were generated for the left BG, right BG and occipital cortex (OCC). The empirical ratios between BG-OCC and OCC, which represent specific-to-nonspecific binding ratios, were computed at various time points. The statistical parameter k3/k4 was estimated by two methods: a variation of the graphic method that derives the ratio of ligand distribution volumes (R[V]) and the area ratio method (R[A]), in which the ratio is calculated from the areas under the specific and nonspecific binding activity curves. RESULTS: The mean (BG-OCC)/OCC ratio for normal controls (3.07 +/- 0.73) was significantly higher than that for Parkinson's disease patients at 115 min (1.10 +/- 0.56) (p = 2.76 x 10[-5]). The mean R(V) and R(A) for normal controls were 2.06 +/- 0.27 and 1.50 +/- 0.15, respectively. The mean R(V) and R(A) for Parkinson's disease patients were 0.78 +/- 0.31 and 0.65 +/- 0.24, respectively. Both R(V) and R(A) for normal controls were significantly higher than those for Parkinson's disease patients (p values for R(V) and R(A) were 1.91 x 10(-8) and 3.46 x 10(-10), respectively). The R(V) has linear relationships with both R(A) and (BG-OCC)/OCC ratio at 115 min. The R(V) has a higher correlation (r = 0.99) with R(A) than it does with (BG-OCC)/OCC (r = 0.93). CONCLUSION: The R(V), R(A) and (BG-OCC)/OCC for Parkinson's disease patients were clearly separated from those of normal controls, and they may be useful outcome measures for clinical diagnosis. The simplest (BG-OCC)/OCC ratio, requiring a single late time point, could be useful in clinical situations, whereas R(V) or R(A) is preferred when the dynamic data are available. The findings suggest that 123I-IPT is a useful tracer for diagnosing Parkinson's disease and studying dopamine reuptake sites.


Assuntos
Encéfalo/diagnóstico por imagem , Proteínas de Transporte/metabolismo , Dopamina/metabolismo , Radioisótopos do Iodo , Glicoproteínas de Membrana , Proteínas de Membrana Transportadoras , Proteínas do Tecido Nervoso , Doença de Parkinson/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Tropanos , Adulto , Encéfalo/metabolismo , Estudos de Casos e Controles , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , Fatores de Tempo
11.
Nucl Med Biol ; 28(7): 829-34, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11578905

RESUMO

We investigated a correlation between the expression of human sodium iodide symporter (hNIS) mRNA and the uptake of 99mTc-pertechnetate in 25 breast tumors. 99mTc-pertechnetate scintigraphy revealed positive uptake in 4 patients. The normalized mRNA expression of hNIS was higher in tumors with positive uptake on the scintigraphy (n=4, median 0.97, range 0.78-1.27) than that in negative uptake tumors (n=21, median 0.46, range 0.10-1.03, p < 0.005). 99mTc-pertechnetate uptake is correlated with the hNIS expression in the breast tumor.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Compostos Radiofarmacêuticos/farmacocinética , Pertecnetato Tc 99m de Sódio/farmacocinética , Simportadores/metabolismo , Neoplasias da Mama/genética , Feminino , Humanos , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , Cintilografia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Simportadores/biossíntese
12.
J Microbiol Methods ; 39(2): 159-69, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10576706

RESUMO

A rapid miniprep method for isolation of DNA from 12 strains of cyanobacteria belonging to groups I, III, IV and V is described. The protocol is a modification of the methods of Boyle and Lew [Boyle, J.S., Lew, A.M., 1995. An inexpensive alternative to glassmilk for DNA purification. Trends Genet. 11, 8] and the cetyltrimethyl ammonium bromide (CTAB) extraction method of Sahgai-Maroof et al. [Sahgai-Maroof, M.A., Soliman, K.M., Jorgensen, R.A., Allard, R.W., 1984. Ribosomal DNA spacer-length polymorphisms in barley: Mendelian inheritance, chromosomal location and population dynamics. Proc. Natl. Acad. Sci. USA 81, 8014-80181. The new method is especially useful for obtaining cyanobacterial DNA from unicellular, filamentous and filamentous branched species. The method does not require phenol extraction and the product can be used directly for PCR amplification and restriction digestion.


Assuntos
Cianobactérias/genética , DNA Bacteriano/isolamento & purificação , Técnicas Bacteriológicas , Cianobactérias/classificação , Cianobactérias/crescimento & desenvolvimento , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Dióxido de Silício
13.
Plant Cell Rep ; 16(10): 686-691, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30727619

RESUMO

Somaclonal-variation-induced multiple mutations were observed in a progeny of the S1587 plant, regenerated from type I calli of the aluminum-tolerant inbred maize line Cat-100-6. After five generations of self-pollination, 14 progeny families of the S1587 somaclone were found to show aluminum toxicity symptoms with altered root tip morphology and reduced primary root growth. The most sensitive progeny, S1587-17, was crossed to the Cat-100-6 inbred line. The parental lines and the F1 were tested in nutrient solutions containing an aluminum activity gradient of 0-93 ⋅ 10-6. The heterozygote behaves like the tolerant parent at aluminum activities up to 40 ⋅ 10-6 and showed an intermediate phenotype at higher aluminum concentrations. Histological sections of aluminum-treated roots from tolerant and sensitive plants stained with hematoxylin, an aluminum marker, showed a progressive destruction of the root tip of the aluminum-sensitive genotype over time and indicated that tolerance in Cat-100-6 could be due to an aluminum exclusion mechanism. Segregation analysis of the F2 and backcross to the sensitive parent based on root morphology of plants subjected to an aluminum activity of 30 ⋅ 10-6 showed the typical 3:1 and 1:1 tolerant:sensitive segregation ratios, respectively, indicating that tolerance in the Cat-100-6 inbred maize line is controlled by a single nuclear, semidominant gene, named Alm1.

14.
Nucl Med Commun ; 22(6): 613-6, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11403170

RESUMO

We investigated a simple and reliable method for the preparation of 99Tcm-dimercaptosuccinic acid (99Tcm(V)-DMSA) without the addition of oxygen. The effect of pH, amount of reducing agent, and oxygen addition in the synthesis of 99Tcm(V)-DMSA were evaluated. At pH 9, we obtained a radiochemical yield of 95% +/- 1.2% within 10 min and a high stability until 7 h, with 92% +/- 1.5% radiochemical purity. However, at a pH lower than 9, the radiochemical yield was below 90% within 10 min, and a longer reaction time was needed to obtain a radiochemical yield above 90%. The addition of oxygen did not have an additional effect on the radiochemical yield or its stability at pH 9, whereas it increased the radiochemical yield of 99Tcm-(V)-DMSA at pH 7. It was noted that the smaller the amount of reducing agent used, the higher was the radiochemical yield obtained at pH 7. However, at pH 9, the radiochemical yield was not dependent on the amount of reducing agent. In conclusion, the synthesis of 99Tcm(V)-DMSA was more dependent on the pH of the reaction mixture than on the amount of reducing agent or the addition of oxygen. The adjustment of pH 9 was the easiest and most effective method for the synthesis of 99Tcm(V)-DMSA using a commercial kit for 99Tcm(III)-DMSA.


Assuntos
Compostos Radiofarmacêuticos/síntese química , Ácido Dimercaptossuccínico Tecnécio Tc 99m/síntese química , Composição de Medicamentos , Concentração de Íons de Hidrogênio , Oxigênio/química , Substâncias Redutoras
15.
Nucl Med Commun ; 23(1): 75-81, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11748441

RESUMO

This study was undertaken in order to prepare 188Re labelled ethylenediamine-N,N,N',N'-tetrakis(methylene phosphonic acid) (EDTMP), and to determine its potential as a therapeutic radiopharmaceutical for the palliation of metastatic bone pain. The effects of pH, incubation methods, and concentrations of stannous chloride, EDTMP, and ammonium perrhenate as a carrier on radiochemical yield and stability were evaluated. Biodistribution studies were performed in male Wistar rats after intravenous injection of 188Re-EDTMP and compared with those of hydroxyethylidene diphosphonate (HEDP). Greater than 95% radiochemical yield of 188Re-EDTMP was obtained under the optimal conditions (0.1 mmol x ml(-1) of EDTMP, 0.5 mg x ml(-1) of stannous chloride, and pH 1.0). Heating the reaction mixture (boiling water for 15 min, and microwave heating for 15 s) and the addition of ammonium perrhenate increased the radiochemical stability (>90% at 3 h, and >80% at 48 h). The biodistribution of 188Re-EDTMP showed high bony uptake and rapid clearance from other organs, and high bone-to-soft tissue ratios, which are similar to 188Re-HEDP. In conclusion, 188Re-EDTMP was prepared with high radiochemical yield and stability, and showed favourable biological characteristics. Microwave heating was a convenient and rapid method for the preparation of 188Re-EDTMP. It is considered that 188Re-EDTMP is a potential therapeutic agent for bone metastasis.


Assuntos
Neoplasias Ósseas/secundário , Compostos Organometálicos/síntese química , Compostos Organometálicos/uso terapêutico , Dor Intratável/tratamento farmacológico , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/uso terapêutico , Animais , Neoplasias Ósseas/fisiopatologia , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Marcação por Isótopo/métodos , Ligantes , Masculino , Compostos Organometálicos/farmacocinética , Dor Intratável/etiologia , Radioisótopos/farmacocinética , Radioisótopos/uso terapêutico , Compostos Radiofarmacêuticos/farmacocinética , Ratos , Ratos Wistar , Substâncias Redutoras , Distribuição Tecidual
16.
Ann Nucl Med ; 10(1): 153-60, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8814722

RESUMO

The choice of collimator and the selection of a filter can affect the quality of clinical SPECT images of the brain. The compromises that 4 different collimators make between spatial resolution and sensitivity were studied by imaging a three-dimensional Hoffmann brain phantom. The planar data were acquired with each collimator on a three-headed SPECT system and were reconstructed with both a standard Butterworth filter and a Wiener pre-filter. The reconstructed images were then evaluated by specialists in nuclear medicine and were also quantitatively analyzed with specific regions of interest (ROI) in the brain. All observers preferred the Wiener filter reconstructed images regardless of the collimator used to acquire the planar images. With this filter, the ultrahigh-resolution fan-beam collimator was the most subjectively preferable and quantitatively produced the highest contrast ratios. The findings support suggestions that higher resolution collimators are preferable to higher sensitivity collimators, and indicate that fan-beam collimators are preferable to parallel-hole collimators for clinical SPECT studies of cerebral perfusion. The results also suggest that Wiener filter enhances the quality of SPECT brain images regardless of which collimator is used to acquire the data.


Assuntos
Encéfalo/diagnóstico por imagem , Tecnécio , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Encéfalo/anatomia & histologia , Simulação por Computador , Interpretação Estatística de Dados , Estudos de Avaliação como Assunto , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos
17.
Clin Nucl Med ; 20(10): 916-21, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8617001

RESUMO

To evaluate the bone SPECT findings of vertebral hemangioma and their relationship to symptoms and MRI findings, the authors reviewed planar and SPECT bone scans and MR images of 15 vertebral hemangioma in 10 patients. All planar bone scan images demonstrated normal findings, except one, SPECT images demonstrated normal findings in 11 vertebral hemangioma less than 3 cm in diameter. Three of four vertebral hemangioma that were 3 cm or larger showed abnormally increased or decreased uptake on SPECT images. There was a disparity between SPECT imaging and MRI.


Assuntos
Hemangioma/diagnóstico por imagem , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/diagnóstico por imagem , Adulto , Feminino , Hemangioma/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Coluna Vertebral/diagnóstico , Coluna Vertebral/patologia , Tomografia Computadorizada de Emissão de Fóton Único
18.
Clin Nucl Med ; 26(1): 33-5, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11139050

RESUMO

Technetium-99m red blood cell (RBC) scintigraphy is a very specific method to differentiate a hemangioma from other hepatic masses. The authors report a case of hepatocellular carcinoma that showed a focal area of increased uptake on Tc-99m RBC SPECT in a 60-year-old man. Dynamic computed tomography and angiography revealed features of both hemangioma and hepatocellular carcinoma. Pathologic examination showed that the portion of the hepatocellular carcinoma that showed increased uptake on Tc-99m RBC scintigraphy had peliosis, which is the likely cause of the radiotracer avidity.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Eritrócitos , Hemangioma/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Peliose Hepática/diagnóstico por imagem , Tecnécio , Tomografia Computadorizada de Emissão de Fóton Único , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/patologia , Diagnóstico Diferencial , Humanos , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Peliose Hepática/complicações , Peliose Hepática/patologia
19.
Foot Ankle Int ; 22(12): 985-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11783926

RESUMO

A new method of repairing Achilles tendons, which uses a small medial skin incision with a Bunnel-type suture, was performed on 14 patients, and the clinical results were found satisfying. In order to restore the Achilles tendon to its original length, restore tensile strength in the suture site, and minimize injury to the sural nerve, an operative procedure has been devised which uses a limited open repair with a Bunnel-type suture. We followed 14 patients who had undergone the new procedure for a mean interval of 26 months after the injury. They returned to work in six weeks and to playing sports in 25 weeks. There were no cases of late rerupture nor injuries to the sural nerve. This technique approximated the preinjury length and resting tension of the musculo-tendinous apparatus and minimized sural nerve injury.


Assuntos
Tendão do Calcâneo/lesões , Tendão do Calcâneo/cirurgia , Procedimentos Ortopédicos/métodos , Traumatismos dos Tendões/cirurgia , Adulto , Feminino , Seguimentos , Humanos , Escala de Gravidade do Ferimento , Masculino , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Amplitude de Movimento Articular/fisiologia , Recuperação de Função Fisiológica , Ruptura Espontânea/cirurgia , Técnicas de Sutura , Resistência à Tração , Fatores de Tempo , Resultado do Tratamento
20.
Appl Radiat Isot ; 54(3): 419-27, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11214876

RESUMO

We have developed an efficient method and an automated synthetic system for the preparation of highly concentrated 188Re-MAG3. Routine production of 188Re-MAG3 for use in intracoronary radiation therapy was performed by compressed air driven semi-automated shielded system. 188Re-MAG3 was prepared with a commercial kit and reducing agents, purified and concentrated by C18 Sep-Pak cartridges to desired radioactivity and volume. Using this automated system, reproducible radiolabeling yields of 80-85% were obtained.


Assuntos
Doença das Coronárias/radioterapia , Oligopeptídeos/síntese química , Oligopeptídeos/uso terapêutico , Compostos Organometálicos/síntese química , Compostos Organometálicos/uso terapêutico , Radioisótopos/uso terapêutico , Compostos Radiofarmacêuticos/síntese química , Compostos Radiofarmacêuticos/uso terapêutico , Rênio/uso terapêutico , Angioplastia Coronária com Balão , Automação , Doença das Coronárias/terapia , Humanos , Métodos
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