Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/cirurgia , Humanos , Mucinas , Pâncreas , Ductos Pancreáticos/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/cirurgiaRESUMO
Background: There are no known predictors of extracorporeal membrane oxygenation (ECMO) induction for single lung transplantation. Objective: The purpose of the present study was to clarify the relationship between variables and ECMO requirements in single lung transplantation. Methods: This study included adult patients who underwent cadaveric single lung transplantation between 2010 and 2019. After general anesthesia, the transplanted lungs were ventilated in all cases. The analysis included 38 patients in the ECMO required (RQ) group and 12 patients in the ECMO non-required (FR) group. Comparisons were made between the two groups for data affecting ECMO implementation, and data that were significantly different were subjected to multivariate analysis. Results: Prior to anesthesia, the bicarbonate (HCO3-) value of the FR group was lower than that of the RQ group (24.6±2.7 vs. 29.7±5.3 mmol/L, p=0.005). Multivariate analysis showed that the cut-off bicarbonate value was 29.6. The area under the receiver operating characteristic curve (AUROC) of the model was 0.869 (R2: 0.331), with a sensitivity of 79% and a specificity of 88%. The odds ratio was 1.63 for every unit increase in the bicarbonate value (95%CI: 1.11-2.39, p<0.001). Further, the FR group had higher arterial blood pressure (mean: 79.0±11.5 vs. 68.9±8.3 mmHg, p=0.030), less blood loss (432±385 vs. 1,623±1,997 g, p<0.001), shorter operation time (417±44 vs. 543±111 min, p<0.001), and shorter ICU stay (11±9 vs. 25±38 days, p=0.039). Conclusion: Preoperative evaluation of bicarbonate could predict the need for ECMO for single lung transplantation.
RESUMO
The quinate dehydrogenase (QDH) from Gluconobacter oxydans IFO3244 exhibits high affinity for quinate, suggesting its application in shikimate production. Nucleotide sequence analysis of the qdh gene revealed a full-length of 2475-bp encoding an 824-amino acid protein. The qdh gene has the unusual TTG translation initiation codon. Conserved regions and a signature sequence for the quinoprotein family were observed. Phylogenetic analysis demonstrated relatedness of QDH from G. oxydans to other quinate/shikimate dehydrogenases with the highest similarity (56%) with that of Acinetobacter calcoaceticus ADP1 and lower similarity (36%) with a membrane-bound glucose dehydrogenase of Escherichia coli. The function of the gene coding for QDH was confirmed by heterologous gene expression in pyrroloquinoline quinone-synthesizing Pseudomonas putida HK5.
Assuntos
Oxirredutases do Álcool/metabolismo , Proteínas de Bactérias/metabolismo , Gluconobacter oxydans/enzimologia , Oxirredutases do Álcool/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Clonagem Molecular , Gluconobacter oxydans/classificação , Dados de Sequência Molecular , Filogenia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Ácido Chiquímico/metabolismoRESUMO
BACKGROUND AND PURPOSE: The newly developed ultra-high-resolution CT is equipped with a 0.25-mm detector, which has one-half the conventional section thickness, one-half the in-plane detector element width, and one-half the reconstructed pixel width compared with conventional-detector CT. Thus, the ultra-high-resolution CT scanner should provide better image quality for microvasculature than the conventional-detector CT scanners. This study aimed to determine whether ultra-high-resolution CT produces superior-quality images of the lenticulostriate arteries compared with conventional-detector CT. MATERIALS AND METHODS: From February 2017 to June 2017, thirteen patients with aneurysms (4 men, 9 women; mean age, 61.2 years) who underwent head CTA with both ultra-high-resolution CT and conventional-detector CT were enrolled. Two board-certified radiologists determined the number of all lenticulostriate arteries on the CTA coronal images of the MCA M1 segment reconstructed from 512 matrixes on conventional-detector CT and 1024 matrixes on ultra-high-resolution CT. RESULTS: There were statistically more lenticulostriate arteries identified on ultra-high-resolution CT (average, 2.85 ± 0.83; 95% CI, 2.509-3.183) than on conventional-detector CT (average, 2.17 ± 0.76; 95% CI, 1.866-2.480) (P = .009) in 16 of the total 26 MCA M1 segments. CONCLUSIONS: Improvements in lenticulostriate artery visualization were the result of the combined package of the ultra-high-resolution CT scanner plus the ultra-high-resolution scanning protocol, which includes higher radiation doses with lower than the national diagnostic reference levels and stronger adaptive iterative dose-reduction processing. This package for ultra-high-resolution CT is a simple, noninvasive, and easily accessible method to evaluate microvasculature such as the lenticulostriate arteries.
Assuntos
Artérias/diagnóstico por imagem , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Neuroimagem/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia/métodos , Estudos RetrospectivosRESUMO
BACKGROUND: Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM. METHOD: This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three-dimensional construction software; cut-off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence-free survival (RFS) were determined using multivariable and Kaplan-Meier analyses. RESULTS: Some 94 patients were included. TTV cut-off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5-year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection. CONCLUSION: TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.
ANTECEDENTES: Aunque el volumen total del tumor (total tumour volume, TTV) puede tener valor pronóstico tras la resección hepática (hepatic resection, HR) en algunas neoplasias sólidas, no se conoce su importancia en las metástasis hepáticas de cáncer colorrectal (colorectal liver metastases, CRLMs). Este estudio analizó el valor pronóstico del TTV en pacientes con CRLMs resecables. MÉTODOS: Revisión retrospectiva de pacientes a los que se realizó una HR por CRLMs entre 2008 y 2017 en un solo centro. El TTV se estimó a partir de imágenes de tomografía computarizada utilizando un programa de reconstrucción 3D; se determinaron los valores de corte mediante un análisis de las características operativas del receptor. Se identificaron los posibles factores pronósticos y se calcularon la supervivencia global (overall survival, OS) y la supervivencia libre de recidiva (recurence-free survival, RFS) mediante análisis multivariados y de Kaplan-Meier. RESULTADOS: Se incluyeron 94 pacientes. Los valores de corte del TTV para la OS y la RFS fueron de 100 mL y 10 mL, respectivamente. En el análisis multivariable para la OS, se incluyeron los tumores del colon derecho, las metástasis linfáticas primarias y la metástasis hepática bilobar; un TTV ≥ 100 mL se asoció de forma independiente con una peor OS (cociente de riesgos instantáneos, hazard ratio, HR, 6,34, i.c. del 95% 2,08-17,9; P = 0,002). En el anáisis para la RFS, se incluyeron tumores primarios de colon derecho y las metástasis linfáticas primarias; un TTV ≥ 10 mL predijo de forma independiente una peor RFS (HR 1,90, i.c. del 95% 1,12-3,57; P = 0,017). Las tasas de OS a los 5 años con TTVs ≥ 100 mL versus < 100 mL fueron del 41% versus 67% (P = 0,006); las tasas de RFS respecto a TTVs ≥ 10 mL versus < 10 mL fueron del 14% versus 58% (P = 0,009). Un TTV ≥ 100 mL conllevó una tasa más elevada (80%) de recidivas no resecables después de la HR inicial. CONCLUSIÓN: El TTV se asoció con la RFS y la OS tras la HR por CRLMs; unos valores ≥ 100 mL conllevan una tasa más elevada de recidiva irresecable.
Assuntos
Neoplasias Colorretais/patologia , Neoplasias Hepáticas/secundário , Carga Tumoral , Idoso , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Japão , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida , Fatores de TempoRESUMO
A 58-year-old man was admitted to our hospital complaining of right chest pain. Chest X-ray and chest computed tomography (CT) disclosed a 9 cm mass in the right anterior mediastinum. The tumor demonstrated low signal intensity on T1-weighted images, and high signal intensity on T2-weighted images. It showed delayed enhancement on dynamic magnetic resonance (MR). The operation was performed and the tumor including the infiltrated pericardium and upper and middle lobe of right lung was resected. Histologically, the tumor showed a multinodular proliferation of spindle-shaped or polygonal tumor cells with abundant myxoid background. The histopathological diagnosis of the tumor was myxoid malignant fibrous histiocytoma (MFH). This is a case report of primary myxoid MFH in the anterior mediastinum. The case is rare in its primary site, but it is typical in CT and MR findings.
Assuntos
Histiocitoma Fibroso Maligno/patologia , Neoplasias do Mediastino/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Tumor imaging with labeled liposomes is slow; although they reach the tumor quickly, their blood clearance is slow, and the high blood background hinders early imaging. We have developed a rapid tumor imaging technique based on the active removal of liposomes from the circulation by using the avidin-biotin system. 67Ga- or 111In-labeled liposomes with biotin molecules bound on the surface were administered to mice bearing sarcoma 180, and avidin was administered 2 h later. The strong affinity between biotin and avidin initiated the aggregation of liposomes, resulting in their rapid removal from the circulation by the reticuloendothelial system, and the blood level of radioactivity was dramatically reduced without any change of the tumor level. Consequently, the tumor:blood ratio reached 14-18 only 2.5 h after liposome injection. Increased accumulation in the liver was also observed. By this method, an acceptable tumor image could be obtained no more than 2 h after administration of labeled liposomes.
Assuntos
Avidina/farmacocinética , Biotina/farmacocinética , Radioisótopos de Gálio/farmacocinética , Radioisótopos de Índio/farmacocinética , Neoplasias/diagnóstico por imagem , Animais , Portadores de Fármacos , Lipossomos , Masculino , Camundongos , Sistema Fagocitário Mononuclear/metabolismo , Neoplasias/irrigação sanguínea , Neoplasias/metabolismo , Cintilografia , Sarcoma 180/irrigação sanguínea , Sarcoma 180/diagnóstico por imagem , Sarcoma 180/metabolismo , Fatores de TempoRESUMO
Several quinoproteins have been newly indicated in acetic acid bacteria, all of which can be applied to fermentative or enzymatic production of useful materials by means of oxidative fermentation. (1) D-Arabitol dehydrogenase from Gluconobacter suboxydans IFO 3257 was purified from the bacterial membrane and found to be a versatile enzyme for oxidation of various substrates to the corresponding oxidation products. It is worthy of notice that the enzyme catalyzes D-gluconate oxidation to 5-keto-D-gluconate, whereas 2-keto-D-gluconate is produced by a flavoprotein D-gluconate dehydrogenase. (2) Membrane-bound cyclic alcohol dehydrogenase was solubilized and purified for the first time from Gluconobacter frateurii CHM 9. When compared with the cytosolic NAD-dependent cyclic alcohol dehydrogenase crystallized from the same strain, the reaction rate in cyclic alcohol oxidation by the membrane enzyme was 100 times stronger than the cytosolic NAD-dependent enzyme. The NAD-dependent enzyme makes no contribution to cyclic alcohol oxidation but contributes to the reduction of cyclic ketones to cyclic alcohols. (3) Meso-erythritol dehydrogenase has been purified from the membrane fraction of G. frateurii CHM 43. The typical properties of quinoproteins were indicated in many respects with the enzyme. It was found that the enzyme, growing cells and also the resting cells of the organism are very effective in producing L-erythrulose. Dihydroxyacetone can be replaced by L-erythrulose for cosmetics for those who are sensitive to dihydroxyacetone. (4) Two different membrane-bound D-sorbitol dehydrogenases were indicated in acetic acid bacteria. One enzyme contributing to L-sorbose production has been identified to be a quinoprotein, while another FAD-containing D-sorbitol dehydrogenase catalyzes D-sorbitol oxidation to D-fructose. D-Fructose production by the oxidative fermentation would be possible by the latter enzyme and it is superior to the well-established D-glucose isomerase, because the oxidative fermentation catalyzes irreversible one-way oxidation of D-sorbitol to D-fructose without any reaction equilibrium, unlike D-glucose isomerase. (5) Quinate dehydrogenase was found in several Gluconobacter strains and other aerobic bacteria like Pseudomonas and Acinetobacter strains. It has become possible to produce dehydroquinate, dehydroshikimate, and shikimate by oxidative fermentation. Quinate dehydrogenase was readily solubilized from the membrane fraction by alkylglucoside in the presence of 0.1 M KCl. A simple purification by hydrophobic chromatography gave a highly purified quinate dehydrogenase that was monodispersed and showed sufficient purity. When quinate dehydrogenase purification was done with Acinetobacter calcoaceticus AC3, which is unable to synthesize PQQ, purified inactive apo-quinate dehydrogenase appeared to be a dimer and it was converted to the monomeric active holo-quinate dehydrogenase by the addition of PQQ.
Assuntos
Oxirredutases do Álcool/metabolismo , Bactérias/metabolismo , Fermentação , L-Iditol 2-Desidrogenase/metabolismo , Quinolonas/metabolismo , Quinonas/metabolismo , Desidrogenase do Álcool de Açúcar/metabolismo , Oxirredução , Cofator PQQRESUMO
Alcohol dehydrogenase (ADH) of acetic acid bacteria functions as the primary dehydrogenase of the ethanol oxidase respiratory chain, where it donates electrons to ubiquinone. In addition to the reduction of ubiquinone, ADHs of Gluconobacter suboxydans and Acetobacter aceti were shown to have a novel function in the oxidation of ubiquinol. The oxidation activity of ubiquinol was detected as an ubiquinol:ferricyanide oxidoreductase activity, which can be monitored by selected wavelength pairs at 273 and 298 nm with a dual-wavelength spectrophotometer. The ubiquinol oxidation activity of G. suboxydans ADH was shown to be two times higher in 'inactive ADH', whose ubiquinone reductase activity is 10 times lower, than with normal 'active' ADH. No activity could be detected in the isolated subunit II or subunit I/III complex, but activity was detectable in the reconstituted ADH complex. Inactive and active ADHs exhibited a 2-3-fold difference in their affinity to ubiquinol despite having the same affinity to ubiquinone. Furthermore, the ubiquinol oxidation site in ADH could be distinguished from the ubiquinone reduction site by differences in their sensitivity to ubiquinone-related inhibitors and by their substrate specificity with several ubiquinone analogues. Thus, the results strongly suggest that the reactions occur at different sites. Furthermore, in situ reconstitution experiments showed that ADH is able to accept electrons from ubiquinol present in Escherichia coli membranes, suggesting the ubiquinol oxidation activity of ADH has a physiological function. Thus, ADH of acetic acid bacteria, which has ubiquinone reduction activity, was shown to have a novel ubiquinol oxidation activity, of which the physiological function in the respiratory chain of the organism is also discussed.
Assuntos
Acetobacter/enzimologia , Álcool Desidrogenase/metabolismo , Ubiquinona/análogos & derivados , Ubiquinona/metabolismo , Álcool Desidrogenase/química , Sítios de Ligação , Transporte de Elétrons , Ativação Enzimática , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Especificidade por SubstratoRESUMO
Amine oxidases (EC 1.4.3.6) from Aspergillus niger, AO-I (2 x 75 kDa) and AO-II (80 kDa), were examined to determine the cofactor structure. Inactivated with p-nitrophenylhydrazine, they showed absorption and fluorescence spectra similar to those published for other copper amine oxidases and to topa hydantoin p-nitrophenylhydrazone. After digestion by thermolysin and pronase, cofactor peptides were purified by HPLC and sequenced. For thermolytic peptides, a typical topa consensus sequence, Asn-X-Glu-Tyr, was obtained for AO-II, although in case of AO-I it overlapped with Val-Val-Ile-Glu-Pro-Tyr-Gly. For pronase peptides of AO-I, only the latter sequence was obtained. NMR and mass spectroscopy confirmed the residue X as topa p-nitrophenylhydrazone in AO-II and revealed the presence of a residue Z attached to the Glu in the peptide Val-Val-Ile-Glu(Z)-Pro of AO-I. This residue was separated from the peptide by hydrolysis and identified as a product derived from topa quinone. The data, together with amino-acid sequence of AO-I, confer strong evidence for topa quinone as the cofactor, bound in the typical consensus sequence. Raman spectra of the p-nitrophenylhydrazone derivative of AO-I and its pronase peptide showed essentially the same peaks matching to a model compound for topa p-nitrophenylhydrazone. However, there may exist an unusual ester link between the topa-404 and Glu-145 in the native enzyme.
Assuntos
Amina Oxidase (contendo Cobre) , Aspergillus niger/enzimologia , Coenzimas/química , Di-Hidroxifenilalanina/análogos & derivados , Ácido Glutâmico/química , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/química , Sequência de Aminoácidos , Coenzimas/análise , Sequência Consenso , Di-Hidroxifenilalanina/análise , Di-Hidroxifenilalanina/química , Modelos Químicos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Fenil-Hidrazinas/química , Análise de SequênciaRESUMO
In this work we isolated a novel crotamine like protein from the Crotalus durissus cascavella venom by combination of molecular exclusion and analytical reverse phase HPLC. Its primary structure was:YKRCHKKGGHCFPKEKICLPPSSDLGKMDCRWKRK-CCKKGS GK. This protein showed a molecular mass of 4892.89 Da that was determined by Matrix Assisted Laser Desorption Ionization Time-of-flight (MALDI-TOF) mass spectrometry. The approximately pI value of this protein was determined in 9.9 by two-dimensional electrophoresis. This crotamine-like protein isolated here and that named as Cro 2 produced skeletal muscle spasm and spastic paralysis in mice similarly to other crotamines like proteins. Cro 2 did not modify the insulin secretion at low glucose concentration (2.8 and 5.6 mM), but at high glucose concentration (16.7 mM) we observed an insulin secretion increasing of 2.7-3.0-fold than to control. The Na+ channel antagonist tetrodoxin (6 mM) decreased glucose and Cro 2-induced insulin secretion. These results suggested that Na+ channel are involved in the insulin secretion. In this article, we also purified some peptide fragment from the treatment of reduced and carboxymethylated Cro 2 (RC-Cro 2) with cyanogen bromide and protease V8 from Staphylococcus aureus. The isolated pancreatic beta-cells were then treated with peptides only at high glucose concentration (16.7 mM), in this condition only two peptides induced insulin secretion. The amino acid sequence homology analysis of the whole crotamine as well as the biologically-active peptide allowed determining the consensus region of the biologically-active crotamine responsible for insulin secretion was KGGHCFPKE and DCRWKWKCCKKGSG.
Assuntos
Venenos de Crotalídeos/química , Venenos de Crotalídeos/metabolismo , Crotalus , Sequência de Aminoácidos , Animais , Venenos de Crotalídeos/isolamento & purificação , Insulina/metabolismo , Secreção de Insulina , Dados de Sequência Molecular , Isoformas de Proteínas/química , Isoformas de Proteínas/isolamento & purificação , Isoformas de Proteínas/metabolismo , Alinhamento de Sequência , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Relação Estrutura-AtividadeRESUMO
Recently, two methods have been proposed for regional cerebral blood flow (rCBF) quantitation using [123I]iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT). The table look-up (TLU) method has been shown to provide both rCBF and volume of distribution, Vd, images from two SPECT scans, while a single-scan autoradiographic (ARG) technique provided rCBF using a fixed and assumed Vd. In both methods, a single blood sample was referred to calibrate the previously determined standard input function. The present multicenter project was designed to evaluate the accuracy of both methods for use as clinical investigative tools. Ten independent institutions performed [123I]IMP-SPECT studies according to both methods in 76 subjects (10 normal volunteers, 32 patients with cerebrovascular disease, and 34 patients with other diseases). Calculated rCBF values were compared with those obtained by the following reference methods available in the participating institutions; [15O] H2O positron emission tomography (PET) (five institutions), [133Xe]SPECT (four institutions), and the [123I]IMP microsphere method (three institutions). Both ARG and TLU methods provided rCBF values that were significantly correlated with those measured by the [15O] H2O PET technique (p < 0.001 for all subjects; overall regression equation, y = 15.14 + 0.54x) and those measured by the [123I]IMP-microsphere method (p < 0.001 for all subjects: y = 2.0 + 0.80x). Significant correlation (p < 0.05) was observed in 18 of 24 subjects studied with the [133Xe] SPECT reference technique (overall regression equation, y = 15.0 + 0.55x). Mean cortical gray matter rCBF in a group of normal subject was 43.9 +/- 3.3 and 43.4 +/- 2.0 ml/min/100 g for the ARG and TLU methods, respectively. Regional Vd of [123I]IMP estimated by the TLU method was 45 ml/ml +/- 20% in the normal cortical region. Close agreement between ARG and TLU rCBF values was observed (y = -3.21 + 1.07x, r = 0.97), confirming the validity of assuming a fixed Vd in the ARG method. Results of this study demonstrate that both the ARG and TLU methods accurately and reliably estimate rCBF in a variety of clinical settings.
Assuntos
Anfetaminas , Circulação Cerebrovascular , Radioisótopos do Iodo , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Autorradiografia , Água Corporal/metabolismo , Dióxido de Carbono/sangue , Criança , Feminino , Humanos , Masculino , Microesferas , Pessoa de Meia-Idade , Radioisótopos de Oxigênio , Radioisótopos de XenônioRESUMO
To perform accurate in vivo quantitation by single photon emission computed tomography, we have developed a new method for detecting body contours for the correction of tissue attenuation. Our method can rapidly derive the best fit contours throughout the body by using the measured axial length of the patient body and Fourier filtering the detected contours which are defined by a unique bit-plane algorithm. We have also evaluated the effects of the body contours on the reconstructed images by using various attenuation correction techniques including a precorrection method (Sorenson, 1974), a postcorrection method (Chang, 1978), a weighted backprojection method, and a radial post correction method (Tanaka, 1983 and 1984). Counts in the specified region-of-interest in phantom images reconstructed by the radial postcorrection, weighted backprojection, and postcorrection methods were more strongly affected by inaccurately detected contours than were counts derived from images reconstructed by the precorrection method.
Assuntos
Superfície Corporal , Tomografia Computadorizada de Emissão/métodos , HumanosRESUMO
Functional gamma imaging, in color, was established for regional cerebral blood flow (rCBF) using 133Xe. During 10 min after intracarotid injection of 133Xe in saline, 60 picture frames of the 133Xe clearance curve for the entire hemisphere were obtained. After nine-point smoothing, the rCBF for each of the 4,096 picture elements was calculated by two methods: the half-time method and the height-over-area method. Both the 133Xe clearance half-times and the calculated CBF values were displayed, using 13 steps of color, as functional CBF images of the brain. Images of peak count and total count were also displayed on the same frame of the color television. Forty-six studies, performed on 37 patients with various cerebral disorders, were divided into two types: diffuse and focal. In the diffuse type, a decrease in CBF was noted in cases of normal-pressure hydrocephalus; successful ventriculoperitoneal shunt operations were followed by recovery of CBF. Occlusion of the middle cerebral artery showed up as a wedge-shaped area of decreased CBF, even when the conventional brain scan looked normal. Increased perfusion to a tumor was frequently associated with decreased CBF in the rest of the lateral hemisphere; such a decrease could be improved by surgical removal of the tumor.
Assuntos
Circulação Cerebrovascular , Cintilografia/métodos , Adulto , Idoso , Encéfalo/irrigação sanguínea , Neoplasias Encefálicas/diagnóstico , Cor , Feminino , Cefaleia/diagnóstico , Humanos , Hidrocefalia de Pressão Normal/diagnóstico , Infarto/diagnóstico , Masculino , Meningioma/diagnóstico , Radioisótopos de XenônioRESUMO
Huntington's disease (HD) is pathologically characterized by neuronal loss and neuroreceptor alterations in the striatum, including a reduction in dopamine receptor density. We evaluated the clinical usefulness of 123I-iodobenzamide (IBZM) D2 receptor SPECT imaging and 99mTc-hexamethylpropyleneamineoxime (HMPAO) brain perfusion SPECT imaging by studying four early symptomatic HD patients, 20 asymptomatic subjects at risk for HD and 22 controls. Striatal D2 receptor binding and perfusion were measured semiquantitatively by calculating striatum-to-frontal cortex IBZM and HMPAO uptake ratios, respectively. The control IBZM ratio (1.58 +/- 0.06) declined with age at 1.5% per decade (r = -0.58, p < 0.005), whereas the HMPAO ratio (1.15 +/- 0.05) did not. All four symptomatic patients had decreased IBZM ratios and three patients also had decreased HMPAO ratios. Five of 20 at-risk subjects had decreased IBZM ratios and two subjects also had decreased HMPAO ratios. Three of the five at-risk subjects showed subtle nonchoreic neurological abnormalities. Decreased striatal D2 receptor binding thus may be detected by IBZM-SPECT in the asymptomatic as well as symptomatic groups, and these changes were more marked than perfusion deficits detected by HMPAO-SPECT. IBZM-SPECT thus appears to be a promising method for early diagnosis and preclinical detection of HD.
Assuntos
Benzamidas , Encéfalo/diagnóstico por imagem , Doença de Huntington/diagnóstico por imagem , Compostos de Organotecnécio , Oximas , Pirrolidinas , Receptores de Dopamina D2/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único , Adolescente , Adulto , Idoso , Encéfalo/irrigação sanguínea , Circulação Cerebrovascular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tecnécio Tc 99m ExametazimaRESUMO
UNLABELLED: To visualize the regional localization of glutathione (GSH) in the brain, the relationship between the concentrations of tissue GSH and uptake of [99mTc]meso-hexamethyl propyleneamine oxime ([99mTc] meso-HMPAO) or [99mTc]d,l-hexamethyl propyleneamine oxime ([99mTc]d,l-HMPAO) was studied in mice. METHODS: The uptake of [99mTc]meso-HMPAO in the mouse brain was decreased to 35% of control paralleling the decrease in GSH content by pre-loading of diethyl maleate (DEM), an agent to reduce GSH. In contrast, pre-treatment with DEM scarcely affected the 99mTc-d,l-HMPAO uptake in the brain. RESULTS: The DEM treatment decreased the GSH content in liver, kidney, spleen, fat and lung but did not affect the uptake of [99mTc]meso-HMPAO in those tissues except lung. The images of rat brain acquired with a gamma camera showed a significant reduction of [99mTc]meso-HMPAO uptake by DEM treatment. CONCLUSION: Technetium-99m-meso-HMPAO may be a potential tool to assess GSH content and to estimate antioxidative ability in the brain.
Assuntos
Encéfalo/metabolismo , Glutationa/metabolismo , Compostos de Organotecnécio , Oximas , Animais , Maleatos/farmacologia , Camundongos , Compostos de Organotecnécio/farmacocinética , Oxirredução , Estresse Oxidativo , Oximas/farmacocinética , Ratos , Ratos Wistar , Estereoisomerismo , Compostos de Sulfidrila/metabolismo , Tecnécio Tc 99m Exametazima , Distribuição TecidualRESUMO
UNLABELLED: A three-dimensional brain imaging protocol with PET and MRI was used to visualize the cortical structure in relation to brain function and glioma infiltration to determine tumor resectability. METHODS: Sixteen patients with glioma had a PET scan with 11C-methionine to visualize tumor infiltration. The PET images were co-registered to the patients' own MRI reconstructed to the three-dimensional brain surface images to indicate the gyral structure and the extent of tumor infiltration. Thirteen patients, who bore tumors adjacent to the language or motor cortex, had H2 15O activation study to locate the eloquent cortex. The area of tumor infiltration was superimposed on the brain surface images together with the language and/or motor cortex. RESULTS: When a tumor was located within a single gyrus without influencing surface cortical gyrus pattern, the motor and language areas were identified morphologically by three-dimensional surface image alone. However, when the tumor caused swelling and deformation of cortical structure, functional mapping with H2(15)O activation technique was essential in locating them correctly. In such cases, the combined mapping of the facial motor area with oral movement and the language area with word repetition was the most useful method to identify the parasylvian structure in the dominant hemisphere. Total or near total resection of low-grade glioma in eight patients and the effective decompression of the active part of the malignant glioma in four patients was completed without causing functional neurological deterioration. CONCLUSION: The three-dimensional expression of cortical structure and function combined with PET glioma imaging with 11C-methionine is useful for radical resection of cerebral glioma.
Assuntos
Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada de Emissão/métodos , Adulto , Astrocitoma/cirurgia , Neoplasias Encefálicas/cirurgia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Metionina , Pessoa de Meia-Idade , Radioisótopos de Oxigênio , Compostos Radiofarmacêuticos , ÁguaRESUMO
To evaluate cerebral hemodynamics, 21 patients with chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery with normal or only lacunar infarction on x-ray CT were studied using single photon emission computed tomography (SPECT). We measured rCBV with 99mTc erythrocytes after rCBF with 133Xe, and calculated rCBV/rCBF. rCBF and rCBV of the 25 affected hemispheres were classified as (a) patients with normal rCBF [type I (n = 7) and type II (n = 3)]; (b) patients with decreased rCBF [type III (n = 6) and type IV (n = 9)]. These two groups then could be subdivided according to findings of rCBV, normal, and increased blood volumes. rCBV/rCBF increased as the cerebral perfusion pressure dropped from type I to type III. In type IV, other situations but cerebral autoregulation could be assumed. rCBV/rCBF signifies vascular mean transit time. Type III (high rCBV/rCBF) assumed as the increased OEF, misery perfusion as reported in PET. We propose rCBF, rCBV and rCBV/rCBF using SPECT can be an index for cerebral circulatory reserve.
Assuntos
Arteriopatias Oclusivas/diagnóstico por imagem , Doenças das Artérias Carótidas/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único , Artéria Carótida Interna , Doenças Arteriais Cerebrais/diagnóstico por imagem , Eritrócitos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tecnécio , Radioisótopos de XenônioRESUMO
Regurgitant fraction (RF) of patients with and without mitral regurgitation (MR) and/or aortic regurgitation (AR) was evaluated by gated cardiac blood-pool scanning using single photon emission computed tomography (SPECT). Using the stroke count image of a short-axis tomogram to separate the right atrium and ventricle, the left ventricular stroke count (LVSC) and right ventricular stroke count (RVSC) were determined. The RF equaled (LVSC - RVSC)/LVSC. Calculated RF in 14 subjects without significant regurgitation by contrast angiography was 5.8 +/- 5.9% (mean +/- s.d.), RF of 17 cases with angiographic regurgitation was 42.5 +/- 16.8% (p less than 0.001). The sensitivity of the radionuclide method compared to angiography was 94% (16/17 cases), and specificity was 100% (14/14 cases). RF of mild Re (1+ or 2+) was 26.0 +/- 8.9% (n = 6) and RF of severe Re (3+ or 4+) was 51.5 +/- 12.7% (n = 11) (p less than 0.001). Correlation between the RF determined with the radionuclide method and with cardiac catheterization was good (y = 5.85 + 0.700 x, r = 0.821, n = 17). We conclude that RF of MR and/or AR can be accurately evaluated by gated cardiac blood-pool scanning using SPECT.
Assuntos
Doença das Coronárias/diagnóstico por imagem , Coração/diagnóstico por imagem , Volume Sistólico , Tomografia Computadorizada de Emissão , Cateterismo Cardíaco , Humanos , MatemáticaRESUMO
We have developed a quantitative method of measuring regional cerebral blood flow (rCBF) by using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography (SPECT). Twenty-five dynamic SPECT images (24 sec/scan) were collected immediately after tracer injection using a ring-type SPECT system and the accumulation curve (C(t)) was obtained. The time-activity curve corresponding to the arterial blood activity curve was used as B(t). The latter curve was calculated from the lung time-activity curve monitored during scanning and corrected by the actual activity obtained by one-point blood sampling 5 min after tracer injection. The octanol extraction ratio during scanning was considered to be constant and taken as the value measured 5 min after tracer injection (E). The uptake constant (K) per pixel was calculated by the least squares fitting method as the slope of the linear relationship in which C(t)/E x B(t) was plotted against E x integral of t(o)B(tau)d tau/E x B(t). Functional maps of rCBF values were obtained on a 64 x 64 matrix by calculating the uptake constant per pixel and the cross calibration factor (CF) between the SPECT system and a well counter (rCBF = K.CF x 100).