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1.
Nature ; 450(7172): 1091-5, 2007 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-18046333

RESUMO

Infection with the malaria parasite Plasmodium falciparum leads to widely different clinical conditions in children, ranging from mild flu-like symptoms to coma and death. Despite the immense medical implications, the genetic and molecular basis of this diversity remains largely unknown. Studies of in vitro gene expression have found few transcriptional differences between different parasite strains. Here we present a large study of in vivo expression profiles of parasites derived directly from blood samples from infected patients. The in vivo expression profiles define three distinct transcriptional states. The biological basis of these states can be interpreted by comparison with an extensive compendium of expression data in the yeast Saccharomyces cerevisiae. The three states in vivo closely resemble, first, active growth based on glycolytic metabolism, second, a starvation response accompanied by metabolism of alternative carbon sources, and third, an environmental stress response. The glycolytic state is highly similar to the known profile of the ring stage in vitro, but the other states have not been observed in vitro. The results reveal a previously unknown physiological diversity in the in vivo biology of the malaria parasite, in particular evidence for a functional mitochondrion in the asexual-stage parasite, and indicate in vivo and in vitro studies to determine how this variation may affect disease manifestations and treatment.


Assuntos
Malária Falciparum/parasitologia , Plasmodium falciparum/metabolismo , Animais , Análise por Conglomerados , Ácidos Graxos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Glicólise/genética , Humanos , Malária Falciparum/sangue , Análise de Sequência com Séries de Oligonucleotídeos , Plasmodium falciparum/genética , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/patogenicidade , Transcrição Gênica , Ácidos Tricarboxílicos/metabolismo
2.
Materials (Basel) ; 15(14)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35888418

RESUMO

We aimed, in this investigation, to prepare novel concretes which can be used in gamma-ray shielding applications. The experimental approach was performed using a NaI (Tl) detector to measure the concrete's shielding features for different energies, ranging from 0.081 MeV to 1.408 MeV. The density of the fabricated concretes decreased with increasing W/C ratio, where the density decreased by 2.680 g/cm3, 2.614 g/cm3, and 2.564 g/cm3 for concretes A, B, and C, respectively, with increases in the W/C ratio of 0.4, 0.6, and 0.8, respectively. When the energy was elevated between 0.08 MeV and 1.408 MeV, the highest values were attained for concrete A, with values ranging between 0.451 cm-1 and 0.179 cm-1. The lowest half-value layer (Δ0.5) values were achieved for concrete C, where the Δ0.5 values varied between 1.53 cm and 3.86 cm between 0.08 MeV and 1.408 MeV. The highest Δ0.5 values were achieved for concrete A, where the Δ0.5 varied between 1.77 cm and 4.67 cm between 0.08 MeV and 1.408 MeV. According to this investigation, concrete A has the highest promise in radiation shielding purposes because it has the most desirable properties of the concretes studied.

3.
Science ; 286(5439): 531-7, 1999 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10521349

RESUMO

Although cancer classification has improved over the past 30 years, there has been no general approach for identifying new cancer classes (class discovery) or for assigning tumors to known classes (class prediction). Here, a generic approach to cancer classification based on gene expression monitoring by DNA microarrays is described and applied to human acute leukemias as a test case. A class discovery procedure automatically discovered the distinction between acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) without previous knowledge of these classes. An automatically derived class predictor was able to determine the class of new leukemia cases. The results demonstrate the feasibility of cancer classification based solely on gene expression monitoring and suggest a general strategy for discovering and predicting cancer classes for other types of cancer, independent of previous biological knowledge.


Assuntos
Perfilação da Expressão Gênica , Leucemia Mieloide/classificação , Leucemia Mieloide/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/classificação , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Doença Aguda , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Adesão Celular/genética , Ciclo Celular/genética , Proteínas de Homeodomínio/genética , Humanos , Leucemia Mieloide/tratamento farmacológico , Proteínas de Neoplasias/genética , Neoplasias/classificação , Neoplasias/genética , Análise de Sequência com Séries de Oligonucleotídeos , Oncogenes , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Resultado do Tratamento
4.
Prog Neuropsychopharmacol Biol Psychiatry ; 33(1): 53-61, 2009 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19000732

RESUMO

BACKGROUND: Processes underlying cortical hypoactivation in schizophrenia are poorly understood but some evidence suggests that a deficient sensory filtering is associated with the condition. This filtering deficit can be studied by using measures of prepulse inhibition (PPI) of the startle reflex. OBJECTIVE: To evaluate the contribution of sensory filtering deficits to cortical hypoperfusion during an attention test in schizophrenia. METHOD: Measurements of PPI of the startle reflex and perfusion during the performance of a Stroop test (assessed with single photon emission tomography) were obtained in 10 acutely treated schizophrenia patients (6 with recent onset, RO) and 16 control subjects. These measurements were compared between patients and controls and the correlation between PPI and perfusion was evaluated within each group, using Statistical Parametric Mapping. RESULTS: In comparison with normal subjects, the patients exhibited lower PPI, although the difference was not statistically significant. Perfusion was significantly lower in the prefrontal and premotor regions of the patients. In the patient group, a statistically significant difference was observed between PPI and perfusion in the parietal, premotor, and cingulate regions. When the associations were analyzed in the RO patients alone, a positive correlation was also found between prefrontal perfusion and PPI, while anterior hippocampal perfusion was inversely related to PPI. CONCLUSIONS: These results support the notion that deficient sensory-motor filtering is associated with decreased cortical task-related activation in schizophrenia.


Assuntos
Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/fisiopatologia , Reflexo de Sobressalto/fisiologia , Esquizofrenia Paranoide/fisiopatologia , Filtro Sensorial , Adulto , Atenção , Feminino , Humanos , Masculino , Projetos Piloto , Desempenho Psicomotor , Psicologia do Esquizofrênico , Tomografia Computadorizada de Emissão de Fóton Único
5.
Trop Biomed ; 36(2): 402-411, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33597401

RESUMO

Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.

6.
Prog Neuropsychopharmacol Biol Psychiatry ; 32(4): 948-54, 2008 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-18262704

RESUMO

BACKGROUND: Previous reports show different cerebral activity patterns during treatment with clozapine and typical neuroleptics. However, to date no study has directly compared the brain activity patterns while subjects are undergoing treatment with clozapine and other atypical antipsychotics. This comparison is of interest, given the probably different mechanism of action of clozapine in comparison with other atypicals. OBJECTIVE: To assess the effect of clozapine on perfusion deviations still evident during treatment with risperidone. METHODS: Here we used hexamethylene-propylenaminoxime single photon emission computed tomography to compare the perfusion patterns observed during the performance of a Stroop test in 10 patients sequentially treated with risperidone and clozapine, owing to a lack of response to the former, and in 10 healthy controls. RESULTS: Patients on risperidone showed decreased perfusion as compared to controls in the medial prefrontal, middle cingulate and insular regions, as well as increased activities in brain stem and the posterior hippocampus. After receiving clozapine, the same patients showed an even wider prefrontal perfusion deficit and the brain stem was still hyperactive, but the abnormalities in the cingulate cortex, insula and hippocampus had disappeared. Clinical improvement was directly related to an increase in thalamic perfusion. CONCLUSION: Clozapine may alleviate hyperactivity in the limbic system in schizophrenia and may facilitate activation of the regions involved in cognitive tasks to a greater degree than risperidone, as well as eliciting greater inhibition of the PF region.


Assuntos
Antipsicóticos/uso terapêutico , Transtornos Cerebrovasculares/induzido quimicamente , Transtornos Cerebrovasculares/tratamento farmacológico , Clozapina/uso terapêutico , Risperidona/uso terapêutico , Esquizofrenia/tratamento farmacológico , Esquizofrenia/fisiopatologia , Adulto , Antipsicóticos/efeitos adversos , Encéfalo/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Cognição/efeitos dos fármacos , Resistência a Medicamentos , Feminino , Haloperidol/uso terapêutico , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Escalas de Graduação Psiquiátrica , Estudos Retrospectivos , Risperidona/efeitos adversos , Esquizofrenia/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único , Falha de Tratamento
7.
Rev Esp Med Nucl Imagen Mol ; 36(5): 312-321, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-28483374

RESUMO

The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using 18F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, 18F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term 'Indeterminate Response' in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials.


Assuntos
Fluordesoxiglucose F18 , Doença de Hodgkin/diagnóstico por imagem , Linfoma não Hodgkin/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos , Doença de Hodgkin/terapia , Humanos , Linfoma não Hodgkin/terapia , Guias de Prática Clínica como Assunto
8.
Rev Esp Med Nucl Imagen Mol ; 34(2): 89-94, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25304848

RESUMO

OBJECTIVE: To describe and validate a novel, fully automated program specifically designed for the semiquantification of striatal (123)I-FP-CIT uptake using volumes of interest (VOI) analysis. MATERIAL AND METHODS: The proposed algorithm is based on a template that mimics the striatal (123)I-FP-CIT uptake in a healthy subjects, derived from defined anatomical VOIs available from WFU PickAtlas. Four SPECT studies of the anthropomorphic Alderson phantom filled with variable radioactive concentrations were acquired for the experimental validation. Experimental SPECT images were spatially normalized with respect to the previously created template. The binary VOIs corresponding to left caudate and putamen and right caudate and putamen, which were used to construct the template, were projected onto the experimental images to obtain the counts for these regions. To minimize the partial volume effect, a percentage of the voxels in these regions (threshold), rather than all of them, was used. A binary occipital VOI was used to quantify the non-specific uptake. Experimental binding potentials (BPs) were calculated from the counts in these regions. True BPs were calculated from aliquots taken from the solutions used to fill the phantom. RESULTS: There were statistically significant differences in the experimental BP values (p<0.002) according to the percentage of voxels used. A highly significant correlation was achieved between true and experimental BP values, regardless of the percentage of voxels included for quantification. CONCLUSIONS: Our novel, observer-independent program automatically performs the semiquantification of striatal (123)I-FP-CIT uptake in experimental studies.


Assuntos
Algoritmos , Corpo Estriado/diagnóstico por imagem , Radioisótopos do Iodo/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Tropanos/farmacocinética , Automação , Corpo Estriado/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Humanos , Radioisótopos do Iodo/análise , Imagens de Fantasmas , Compostos Radiofarmacêuticos/análise , Tomografia Computadorizada de Emissão de Fóton Único , Tropanos/análise
10.
Eur J Cell Biol ; 80(5): 321-8, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11432721

RESUMO

Lymphocyte activation is known to be associated with the induction of genes implicated in cytokine signaling and cellular proliferation. High-density microarrays offer the means to monitor global cellular expression profiles, temporal relationships between classes of transcripts, and alterations associated with human disease or immunosuppression. We sought to determine whether microarray analysis would accurately reflect the normal pattern of gene expression following human T cell activation, and whether the complex expression patterns identified could be analyzed to produce a functional profile of lymphocyte activation. We examined a time course of sequential expression profiles for 6,800 cellular transcripts in human lymphocytes activated with concanavalin A. Expression patterns were grouped using clustering analysis and validated using Northern blotting. Genes known to be induced following T cell activation were accurately identified, and the qualitative patterns of gene expression were well correlated between Northern and microarray analyses. Quantitative differences in gene expression levels were less well correlated between these two techniques. Expression profile analysis revealed the sequential induction of groups of functionally similar genes, whose temporal coregulation underscores known cellular events during T cell activation. This functional "fingerprint" of lymphocyte activation may prove useful for comparisons of lymphocyte responses under experimental conditions and in disease states.


Assuntos
Ativação Linfocitária/genética , Linfócitos T/fisiologia , Ativação Transcricional/imunologia , Análise por Conglomerados , Expressão Gênica/imunologia , Humanos , Análise de Sequência com Séries de Oligonucleotídeos
11.
Tropical Biomedicine ; : 402-411, 2019.
Artigo em Inglês | WPRIM | ID: wpr-777847

RESUMO

@#Schistosomiasis japonica is one of seven NTDs endemic in the Philippines that continues to threaten public health in the country. The causative agent, the blood fluke Schistosoma japonicum, uses an amphibious snail Oncomelania hupensis quadrasi which can harbor larval stages that multiply asexually, eventually producing the infective cercariae which are shed into the water. Contamination of freshwater bodies inhabited by the snail intermediate host occurs through release of human and animal feces containing S. japonicum eggs. Miracidia hatching from these eggs subsequently infect the snails that inhabit these water bodies. The degree of fecal contamination can vary across snail sites and influences snail infection rates in these sites. In this study, conventional malacological surveys using intensive manual search for snails were conducted from 2015 to 2016 in seven selected endemic provinces, namely Leyte and Bohol in the Visayas and Surigao del Norte, Agusan del Sur, Bukidnon, Lanao del Norte and Compostela Valley in Mindanao. A total of 6,279 O. hupensis quadrasi snails were collected from 38 snail sites. The municipality of Trento in Agusan del Sur recorded the highest number of snail sites (7) that yielded O. hupensis quadrasi snails while only one snail site was found positive for O. hupensis quadrasi snails in Kapatagan in Lanao del Norte and Talibon in Bohol. Alegria in Surigao del Norte yielded the highest number of snail sites (5) that were found to harbor snails positive for S. japonicum infection. The snail infection rates in this municipality ranged from 0.43% to 14.71%. None of the snails collected from Talibon in Bohol was infected. Bohol is the only province among the 28 schistosomiasis-endemic provinces which has reached near elimination status. Snail infection rates were found to vary considerably across snail sites, which could be due to the degree of fecal contamination of the snail sites and their connectivity to water that can serve as contamination source.

12.
Phys Rev Lett ; 66(15): 2049, 1991 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10043378
13.
Phys Rev Lett ; 62(10): 1087-1090, 1989 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-10039573
14.
Phys Rev Lett ; 63(25): 2757-2759, 1989 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-10040982
15.
Phys Rev Lett ; 62(2): 163-166, 1989 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-10039939
16.
Phys Rev B Condens Matter ; 38(16): 11471-11475, 1988 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-9946027
17.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 36(5): 312-321, sept.-oct. 2017. ilus, tab
Artigo em Espanhol | IBECS (Espanha) | ID: ibc-165497

RESUMO

El objetivo de la presente revisión es actualizar las recomendaciones sobre el papel de la tomografía por emisión de positrones (PET)/tomografía computarizada (TC) en la estadificación y valoración de la respuesta tras quimioterapia y/o trasplante de progenitores hematopoyéticos en pacientes con linfoma de Hodgkin (LH) y linfoma no-Hodgkin (LNH) en la práctica clínica habitual. En la primera reunión internacional sobre PET en linfoma, celebrada en 2009 en Deauville (Francia), se estableció una escala de 5 puntos para la valoración de la respuesta en pacientes con linfoma mediante la 18F-Fluordeoxiglucosa (FDG) PET/TC. Posteriormente, tras celebrarse la 11.a y 12.a Conferencia Internacional sobre Linfomas en Lugano (Suiza) en 2011 y 2013, respectivamente, se alcanzó un acuerdo en cuanto al uso de la PET/TC para la estadificación y se revisaron los criterios de respuesta en linfoma ávidos por la FDG en la práctica clínica y en ensayos clínicos; son los denominados criterios de valoración de respuesta de Lugano. Los principales consensos alcanzados fueron: I) la PET/TC con 18F-FDG fue formalmente incorporada en la estadificación de los linfomas con avidez por la FDG; II) la biopsia de médula ósea ya no está indicada en la estadificación rutinaria de pacientes con LH y en la mayoría de los pacientes con linfoma B difuso de células grandes (LBDCG), y III) la valoración de respuesta al tratamiento se hará mediante la PET/TC usando la escala de 5 puntos y la clasificación de Lugano. Actualmente, con la introducción de terapias basadas en agentes biológicos con mecanismos inmunes, los criterios de Lugano para valoración de la respuesta requieren una flexibilización y modificación, debido a que estos agentes pueden producir cambios en las técnicas de imagen que sugieren progresión de la enfermedad, a pesar de una respuesta clínica evidente (pseudoprogresión o tumor flare). Ello ha llevado a la adopción provisional de los criterios LYRIC (LYmphoma Response to Inmunomodulatory Therapy Criteria), con la introducción del término «respuesta indeterminada» para definir estos cambios hasta que sean confirmados o descartados como progresión de la enfermedad. El uso generalizado de todas estas recomendaciones mejorará la evaluación de pacientes con linfoma y hará posible la comparación de resultados procedentes de ensayos clínicos (AU)


The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using 18F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, 18F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term ‘Indeterminate Response’ in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials (AU)


Assuntos
Humanos , Linfoma/diagnóstico , Linfoma/terapia , Fluordesoxiglucose F18/análise , Tomografia por Emissão de Pósitrons/métodos , Relação Dose-Resposta à Radiação , Relação Dose-Resposta Imunológica , Transplante Autólogo/métodos , Estadiamento de Neoplasias/instrumentação , Estadiamento de Neoplasias , Prognóstico , Transplante Homólogo , Imunomodulação
18.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 34(2): 89-94, mar.-abr. 2015. tab, ilus, graf
Artigo em Inglês | IBECS (Espanha) | ID: ibc-134603

RESUMO

Objective: To describe and validate a novel, fully automated program specifically designed for the semi- quantification of striatal 123I-FP-CIT uptake using volumes of interest (VOI) analysis. Material and methods: The proposed algorithm is based on a template that mimics the striatal 123 I-FP-CIT uptake in a healthy subjects, derived from defined anatomical VOIs available from WFU PickAtlas. Four SPECT studies of the anthropomorphic Alderson phantom filled with variable radioactive concentrations were acquired for the experimental validation. Experimental SPECT images were spatially normalized with respect to the previously created template. The binary VOIs corresponding to left caudate and puta- men and right caudate and putamen, which were used to construct the template, were projected onto the experimental images to obtain the counts for these regions. To minimize the partial volume effect, a percentage of the voxels in these regions (threshold), rather than all of them, was used. A binary occipital VOI was used to quantify the non-specific uptake. Experimental binding potentials (BPs) were calculated from the counts in these regions. True BPs were calculated from aliquots taken from the solutions used to fill the phantom. Results: There were statistically significant differences in the experimental BP values (p < 0.002) accord- ing to the percentage of voxels used. A highly significant correlation was achieved between true and experimental BP values, regardless of the percentage of voxels included for quantification. Conclusions: Our novel, observer-independent program automatically performs the semiquantification of striatal 123I-FP-CIT uptake in experimental studies (AU)


Objetivos: Describir y validar un nuevo software, totalmente automático, específicamente diseñado para semicuantificar la captación estriatal de 123I-FP-CIT usando volúmenes de interés (VOIs). Material y métodos: El algoritmo propuesto se basa en una plantilla que remeda la captación estriatal de 123I-FP-CIT en un sujeto sano, obtenida a partir de VOIs anatómicos definidos en WFU PickAtlas. Para la validación experimental de este algoritmo se adquirieron 4 estudios SPECT del maniquí antropomórfico Alderson llenado con concentraciones radioactivas variables. Las imágenes SPECT experimentales se normalizaron espacialmente respecto a la plantilla creada. Los VOIs binarios correspondientes a núcleo caudado y putámen derechos e izquierdos, utilizados para disen ̃ar la plantilla, se proyectaron sobre las imágenes experimentales para obtener las cuentas en estas regiones. Para minimizar los efectos de volumen parcial se utilizó un porcentaje de vóxeles, en vez de utilizar todos los vóxeles contenidos en estos VOIs. Se ha utilizado un VOI binario situado en región occipital para cuantificar la unión no específica. Los potenciales de unión (BPs) experimentales se calcularon a partir de las cuentas obtenidas en estas regiones. Los BPs reales se calcularon a partir de alícuotas tomadas de las soluciones utilizadas para llenar el maniquí. Resultados: Hubo diferencias estadísticamente significativas en los BPs experimentales en función del porcentaje de vóxeles utilizados para la cuantificación (p < 0.002). Se alcanzó una alta correlación entre los BPs reales y los experimentales, independientemente del porcentaje de vóxeles utilizados para la cuantificación. Conclusiones: Este nuevo programa automático e independiente del observador realiza la semicuantificación de la captación estriatal de 123I-FP-CIT en estudios experimentales (AU)


Assuntos
Humanos , Iofetamina , Gânglios da Base/ultraestrutura , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Imagens de Fantasmas , Voluntários Saudáveis , Putamen/ultraestrutura , Núcleo Caudado/ultraestrutura
19.
Neuroendocrinology ; 62(3): 308-12, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8538869

RESUMO

Perinatal dopaminergic blockade with haloperidol caused PRL increases in rat pituitary gland and serum which persisted during the first postnatal month. However the effects of dopamine on the synthesis and secretion of GH at these early ages are unknown. With the aim of investigating the effects of this blockade on postnatal GH secretion, haloperidol (1 mg/kg i.p.) was injected daily to pregnant rats from gestational day 16 until delivery and to pups from untreated mothers between postnatal days 2-6. GH pituitary contents and serum levels were measured weekly by RIA during the first postnatal month. The results showed that haloperidol induced a long-term increase in GH pituitary contents as well as a transient increase in serum levels. The results in serum are similar to those from human neonates indicating that dopamine plays a more important role as controller of the GH secretion in newborns than in adults.


Assuntos
Animais Recém-Nascidos/crescimento & desenvolvimento , Hormônio do Crescimento/sangue , Haloperidol/farmacologia , Hipófise/efeitos dos fármacos , Fatores Etários , Animais , Feminino , Hormônio do Crescimento/metabolismo , Gravidez , Ratos , Ratos Wistar
20.
Proc Natl Acad Sci U S A ; 97(22): 12182-6, 2000 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-11027309

RESUMO

In an effort to find gene regulatory networks and clusters of genes that affect cancer susceptibility to anticancer agents, we joined a database with baseline expression levels of 7,245 genes measured by using microarrays in 60 cancer cell lines, to a database with the amounts of 5,084 anticancer agents needed to inhibit growth of those same cell lines. Comprehensive pair-wise correlations were calculated between gene expression and measures of agent susceptibility. Associations weaker than a threshold strength were removed, leaving networks of highly correlated genes and agents called relevance networks. Hypotheses for potential single-gene determinants of anticancer agent susceptibility were constructed. The effect of random chance in the large number of calculations performed was empirically determined by repeated random permutation testing; only associations stronger than those seen in multiply permuted data were used in clustering. We discuss the advantages of this methodology over alternative approaches, such as phylogenetic-type tree clustering and self-organizing maps.


Assuntos
Antineoplásicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , RNA Neoplásico/genética , Perfilação da Expressão Gênica , Humanos , Família Multigênica , Células Tumorais Cultivadas
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