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1.
Braz. j. biol ; 83: 1-13, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1468809

RESUMO

Interactions between endophytic fungi (EFs) and their host plants range from positive to neutral to negative. The results of such interactions can vary depending on the organ of the infected host plant. EFs isolated from the leaves of some species of plants have potential for use as agents to inhibit seed germination and control invasive plants. The objectives of this study were to identify EFs present in the leaves of Copaifera oblongifolia and to evaluate the role of these fungi in seed germination and seedling development. A total of 11 species of EFs were isolated, which were identified using the internal transcribed spacers (ITS) sequence of the nuclear ribosomal DNA. The isolated species of EFs are generalists and probably are transmitted horizontally. Laboratory tests revealed that filtrates of these fungal isolates differently affect seed germination and seedling development of C. oblongifolia. The species Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum and Phomopsis sp. negatively affected seed germination, with N. parvum standing out for its negative effects, inhibiting seedling germination and survival in 89 and 222%, respectively. In addition, Cochliobolus intermedius negatively affected seedling development. Thus, the combined use of N. parvum and C. intermedius, or products from the metabolism of these microorganisms, in the control of invasive plants deserves attention from future studies.


As interações entre fungos endofíticos (FEs) e suas plantas hospedeiras variam de positivas, neutras a negativas. Os resultados destas interações podem variar dependendo do órgão da planta hospedeira infectada. FEs isolados de folhas de algumas espécies de plantas têm potencial para serem usados como agentes inibidores da germinação de sementes e no controle de plantas invasoras. Os objetivos deste estudo foram identificar os FEs presentes nas folhas de Copaifera oblongifolia e avaliar o papel destes fungos na germinação das sementes e no desenvolvimento das plântulas. Um total de 11 espécies de FEs foi isolado das folhas de C. oblongifolia e identificado através da sequência dos espaçadores internos transcritos do DNA ribossomal nuclear. As espécies de FEs isoladas são generalistas e provavelmente devem ser transmitidas horizontalmente. Os resultados dos testes de germinação mostraram que filtrados destes isolados fúngicos podem afetar diferentemente a germinação das sementes e o desenvolvimento das plântulas de C. oblongifolia. As espécies Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum e Phomopsis sp. afetaram negativamente a germinação das sementes de C. oblongifolia. Dentre estas espécies devemos destacar que N. parvum reduziu a germinação e a sobrevivência das plântulas em 89 e 222%, respectivamente. Além disso, Cochiliobolus intermedius afetou negativamente o desenvolvimento das plântulas. Assim, o uso combinado de N. parvum e C. intermedius, ou de produtos do metabolismo destas espécies de fungos, têm potencial para serem usados no manejo de plantas invasoras.


Assuntos
Animais , DNA Ribossômico/análise , Fabaceae/crescimento & desenvolvimento , Fungos/patogenicidade , Germinação , Interações entre Hospedeiro e Microrganismos , Plântula/crescimento & desenvolvimento
2.
Braz. j. biol ; 832023.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469025

RESUMO

Abstract Interactions between endophytic fungi (EFs) and their host plants range from positive to neutral to negative. The results of such interactions can vary depending on the organ of the infected host plant. EFs isolated from the leaves of some species of plants have potential for use as agents to inhibit seed germination and control invasive plants. The objectives of this study were to identify EFs present in the leaves of Copaifera oblongifolia and to evaluate the role of these fungi in seed germination and seedling development. A total of 11 species of EFs were isolated, which were identified using the internal transcribed spacers (ITS) sequence of the nuclear ribosomal DNA. The isolated species of EFs are generalists and probably are transmitted horizontally. Laboratory tests revealed that filtrates of these fungal isolates differently affect seed germination and seedling development of C. oblongifolia. The species Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum and Phomopsis sp. negatively affected seed germination, with N. parvum standing out for its negative effects, inhibiting seedling germination and survival in 89 and 222%, respectively. In addition, Cochliobolus intermedius negatively affected seedling development. Thus, the combined use of N. parvum and C. intermedius, or products from the metabolism of these microorganisms, in the control of invasive plants deserves attention from future studies.


Resumo As interações entre fungos endofíticos (FEs) e suas plantas hospedeiras variam de positivas, neutras a negativas. Os resultados destas interações podem variar dependendo do órgão da planta hospedeira infectada. FEs isolados de folhas de algumas espécies de plantas têm potencial para serem usados como agentes inibidores da germinação de sementes e no controle de plantas invasoras. Os objetivos deste estudo foram identificar os FEs presentes nas folhas de Copaifera oblongifolia e avaliar o papel destes fungos na germinação das sementes e no desenvolvimento das plântulas. Um total de 11 espécies de FEs foi isolado das folhas de C. oblongifolia e identificado através da sequência dos espaçadores internos transcritos do DNA ribossomal nuclear. As espécies de FEs isoladas são generalistas e provavelmente devem ser transmitidas horizontalmente. Os resultados dos testes de germinação mostraram que filtrados destes isolados fúngicos podem afetar diferentemente a germinação das sementes e o desenvolvimento das plântulas de C. oblongifolia. As espécies Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum e Phomopsis sp. afetaram negativamente a germinação das sementes de C. oblongifolia. Dentre estas espécies devemos destacar que N. parvum reduziu a germinação e a sobrevivência das plântulas em 89 e 222%, respectivamente. Além disso, Cochiliobolus intermedius afetou negativamente o desenvolvimento das plântulas. Assim, o uso combinado de N. parvum e C. intermedius, ou de produtos do metabolismo destas espécies de fungos, têm potencial para serem usados no manejo de plantas invasoras.

3.
Braz. j. biol ; 83: e242070, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278554

RESUMO

Abstract Interactions between endophytic fungi (EFs) and their host plants range from positive to neutral to negative. The results of such interactions can vary depending on the organ of the infected host plant. EFs isolated from the leaves of some species of plants have potential for use as agents to inhibit seed germination and control invasive plants. The objectives of this study were to identify EFs present in the leaves of Copaifera oblongifolia and to evaluate the role of these fungi in seed germination and seedling development. A total of 11 species of EFs were isolated, which were identified using the internal transcribed spacers (ITS) sequence of the nuclear ribosomal DNA. The isolated species of EFs are generalists and probably are transmitted horizontally. Laboratory tests revealed that filtrates of these fungal isolates differently affect seed germination and seedling development of C. oblongifolia. The species Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum and Phomopsis sp. negatively affected seed germination, with N. parvum standing out for its negative effects, inhibiting seedling germination and survival in 89 and 222%, respectively. In addition, Cochliobolus intermedius negatively affected seedling development. Thus, the combined use of N. parvum and C. intermedius, or products from the metabolism of these microorganisms, in the control of invasive plants deserves attention from future studies.


Resumo As interações entre fungos endofíticos (FEs) e suas plantas hospedeiras variam de positivas, neutras a negativas. Os resultados destas interações podem variar dependendo do órgão da planta hospedeira infectada. FEs isolados de folhas de algumas espécies de plantas têm potencial para serem usados como agentes inibidores da germinação de sementes e no controle de plantas invasoras. Os objetivos deste estudo foram identificar os FEs presentes nas folhas de Copaifera oblongifolia e avaliar o papel destes fungos na germinação das sementes e no desenvolvimento das plântulas. Um total de 11 espécies de FEs foi isolado das folhas de C. oblongifolia e identificado através da sequência dos espaçadores internos transcritos do DNA ribossomal nuclear. As espécies de FEs isoladas são generalistas e provavelmente devem ser transmitidas horizontalmente. Os resultados dos testes de germinação mostraram que filtrados destes isolados fúngicos podem afetar diferentemente a germinação das sementes e o desenvolvimento das plântulas de C. oblongifolia. As espécies Curvularia intermedia, Neofusicoccum parvum, Pseudofusicoccum stromaticum e Phomopsis sp. afetaram negativamente a germinação das sementes de C. oblongifolia. Dentre estas espécies devemos destacar que N. parvum reduziu a germinação e a sobrevivência das plântulas em 89 e 222%, respectivamente. Além disso, Cochiliobolus intermedius afetou negativamente o desenvolvimento das plântulas. Assim, o uso combinado de N. parvum e C. intermedius, ou de produtos do metabolismo destas espécies de fungos, têm potencial para serem usados no manejo de plantas invasoras.


Assuntos
Germinação , Fabaceae , Ascomicetos , Sementes , Folhas de Planta , Plântula , Fungos , Curvularia
4.
Braz. j. biol ; 78(3): 464-471, Aug. 2018. tab
Artigo em Inglês | LILACS | ID: biblio-951584

RESUMO

Abstract The fish may experience periods of food deprivation or starvation which produce metabolic changes. In this study, adult Rhamdia quelen males were subjected to fasting periods of 1, 7, 14, and 21 days and of refeeding 2, 4, 6, and 12 days. The results demonstrated that liver protein was depleted after 1 day of fasting, but recovered after 6 days of refeeding. After 14 days of fasting, mobilization in the lipids of the muscular tissue took place, and these reserves began to re-establish themselves after 4 days of refeeding. Plasmatic triglycerides increased after 1 day of fasting, and decreased following 2 days of refeeding. The glycerol in the plasma oscillated constantly during the different periods of fasting and refeeding. Changes in the metabolism of both protein and lipids during these periods can be considered as survival strategies used by R. quelen. The difference in the metabolic profile of the tissues, the influence of the period of fasting, and the type of reserves mobilized were all in evidence.


Resumo Os peixes podem sofrer períodos de privação de alimentos ou de fome, que produzem mudanças metabólicas. Neste estudo, jundiás machos adultos foram submetidos a jejum períodos de 1, 7, 14 e 21 dias e realimentação 2, 4, 6, e 12 dias. Os resultados demonstraram que a proteína do fígado foi esgotada depois de um dia de jejum, mas restabeleceu após 6 dias de realimentação. Após 14 dias de jejum, ocorreu a mobilização dos lípidos no tecido muscular sendo que estas reservas começaram a re-estabelecer-se após 4 dias de realimentação. Os triglicérides plasmáticos aumentam após um dia de jejum, e diminuiram após 2 dias de realimentação. O glicerol no plasma oscilou constantemente durante os diferentes períodos de jejum e realimentação. As alterações no metabolismo de proteína e lipídios durante estes períodos podem ser consideradas uma estratégias de sobrevivência utilizada pelo Rhamdia quelen. Sendo que a diferença no perfil metabólico tecidual bem como a influência do período de jejum e o tipo de reserva a ser mobilizada foram observadas neste estudo.


Assuntos
Animais , Masculino , Peixes-Gato/fisiologia , Jejum/fisiologia , Metabolismo Energético/fisiologia , Metabolismo dos Lipídeos/fisiologia , Comportamento Alimentar , Adaptação Fisiológica , Jejum/metabolismo , Glicogênio/metabolismo , Lipídeos/sangue , Ração Animal , Músculos
5.
J Dairy Sci ; 101(8): 7082-7094, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29729912

RESUMO

The present study investigated production responses and ruminal fermentation characteristics of lactating dairy cows when supplemented with N-acetyl-l-Met (NALM) as a source of rumen-protected Met in metabolizable protein (MP)-deficient (MPD) or MP-adequate diet (MPA). Eight lactating dairy cows (53 ± 10.4 d in milk, average ± standard deviation) were blocked by parity and days in milk, and the experiment was performed in a replicated 4 × 4 Latin square design. Within each square, cows were randomly assigned to a sequence of 4 diets during each of the four 21-d periods (14 d of treatment adaptation and 7 d of data collection and sampling). A 2 × 2 factorial arrangement was used; MPD or MPA was combined without or with NALM: MPD without NALM, MPD with NALM (MPD+NALM), MPA without NALM, and MPA with NALM (MPA+NALM). A NALM product was supplemented in the MPD+NALM and the MPA+NALM at 30 g/cow per d. Supplementation of NALM did not affect dry matter intake (DMI) and milk yield regardless of MP concentration. In addition, supplementing NALM resulted in a similar milk true protein concentration and yield. In contrast, NALM supplementation increased milk fat concentration and yield and 3.5% fat-corrected milk yield and tended to increase energy-corrected milk yield regardless of MP difference. Additionally, trends were observed for increased 3.5% fat-corrected milk yield/DMI and energy-corrected milk yield/DMI, and the positive effects were greater under the MPA than the MPD diet, resulting in trends toward interactions between MP and NALM. Dietary treatments had similar effects on ruminal fermentation characteristics and microbial protein yield. Plasma concentration of Met increased under the MPD but not the MPA diet, leading to an MP × NALM interaction. Overall results in the current study suggest that NALM exerted a minor influence on ruminal metabolism, but increased milk fat concentration, resulting in increases in milk fat yield and feed efficiency. Yet, potential effects of NALM on intermediary metabolism between the gastrointestinal tract, the liver, and the mammary gland need to be explored to understand utilization efficiency for production of dairy cows.


Assuntos
Ração Animal , Dieta , Lactação/fisiologia , Metionina/administração & dosagem , Rúmen/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Digestão , Feminino , Fermentação , Leite
6.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467092

RESUMO

Abstract The fish may experience periods of food deprivation or starvation which produce metabolic changes. In this study, adult Rhamdia quelen males were subjected to fasting periods of 1, 7, 14, and 21 days and of refeeding 2, 4, 6, and 12 days. The results demonstrated that liver protein was depleted after 1 day of fasting, but recovered after 6 days of refeeding. After 14 days of fasting, mobilization in the lipids of the muscular tissue took place, and these reserves began to re-establish themselves after 4 days of refeeding. Plasmatic triglycerides increased after 1 day of fasting, and decreased following 2 days of refeeding. The glycerol in the plasma oscillated constantly during the different periods of fasting and refeeding. Changes in the metabolism of both protein and lipids during these periods can be considered as survival strategies used by R. quelen. The difference in the metabolic profile of the tissues, the influence of the period of fasting, and the type of reserves mobilized were all in evidence.


Resumo Os peixes podem sofrer períodos de privação de alimentos ou de fome, que produzem mudanças metabólicas. Neste estudo, jundiás machos adultos foram submetidos a jejum períodos de 1, 7, 14 e 21 dias e realimentação 2, 4, 6, e 12 dias. Os resultados demonstraram que a proteína do fígado foi esgotada depois de um dia de jejum, mas restabeleceu após 6 dias de realimentação. Após 14 dias de jejum, ocorreu a mobilização dos lípidos no tecido muscular sendo que estas reservas começaram a re-estabelecer-se após 4 dias de realimentação. Os triglicérides plasmáticos aumentam após um dia de jejum, e diminuiram após 2 dias de realimentação. O glicerol no plasma oscilou constantemente durante os diferentes períodos de jejum e realimentação. As alterações no metabolismo de proteína e lipídios durante estes períodos podem ser consideradas uma estratégias de sobrevivência utilizada pelo Rhamdia quelen. Sendo que a diferença no perfil metabólico tecidual bem como a influência do período de jejum e o tipo de reserva a ser mobilizada foram observadas neste estudo.

7.
Respir Med ; 103(6): 854-60, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19201182

RESUMO

RATIONALE: Mixed connective tissue disease is a systemic inflammatory disorder that results in both pulmonary and esophageal manifestations. OBJECTIVES: We sought to evaluate the relationship between esophageal dysfunction and interstitial lung disease in patients with mixed connective tissue disease. METHODS: We correlated the pulmonary function data and the high-resolution computed tomography findings of interstitial lung disease with the results of esophageal evaluation in manometry, 24-hour intraesophageal pH measurements, and the presence of esophageal dilatation on computed tomography scan. MEASUREMENTS AND MAIN RESULTS: Fifty consecutive patients with mixed connective tissue disease, according to Kasukawa's classification criteria, were included in this prospective study. High-resolution computed tomography parenchymal abnormalities were present in 39 of 50 patients. Esophageal dilatation, gastroesophageal reflux, and esophageal motor impairment were also very prevalent (28 of 50, 18 of 36, and 30 of 36, respectively). The presence of interstitial lung disease on computed tomography was significantly higher among patients with esophageal dilatation (92% vs. 45%; p<0.01) and among patients with severe motor dysfunction (90% vs. 35%; p<0.001). CONCLUSIONS: Although we were not able to prove a causal relationship between esophageal and pulmonary involvement, our series revealed a strong association between esophageal motor dysfunction and interstitial lung disease in patients with mixed connective tissue disease.


Assuntos
Refluxo Gastroesofágico/complicações , Doenças Pulmonares Intersticiais/complicações , Doença Mista do Tecido Conjuntivo/complicações , Adulto , Idoso , Dilatação Patológica/diagnóstico , Monitoramento do pH Esofágico , Esôfago/patologia , Esôfago/fisiopatologia , Feminino , Refluxo Gastroesofágico/fisiopatologia , Humanos , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Doenças Pulmonares Intersticiais/fisiopatologia , Masculino , Manometria , Pessoa de Meia-Idade , Doença Mista do Tecido Conjuntivo/diagnóstico por imagem , Doença Mista do Tecido Conjuntivo/fisiopatologia , Estudos Prospectivos , Testes de Função Respiratória , Fumar/epidemiologia , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
8.
Mol Genet Genomics ; 265(2): 264-75, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11361337

RESUMO

The anti-cancer drug camptothecin targets eukaryotic DNA topoisomerase I by trapping the covalent complex formed between the catalytically active enzyme and DNA. We are interested in identifying factors, other than topoisomerase I, that are involved in mediating cellular sensitivity to camptothecin. To this end, we have isolated eighteen mutants that are sensitive to camptothecin (sca) in the filamentous fungus Aspergillus nidulans and characterised one of them, sca299. The mutant sca299 is hypersensitive to camptothecin, and sensitive to several different mutagenic agents and to actinomycin D. Using temperature-sensitive mutations in genes that are known to regulate the cell cycle, we showed that the camptothecin sensitivity of the mutant sca299 is not affected by a mitotic block. The abnormal nuclear morphology observed in the sca299 mutant strain suggests that the germlings might be undergoing mitosis in the presence of unrepaired DNA damage, which would result in mitotic catastrophe. The hypersensitivity of the sca299 mutant to camptothecin does not result from elevated levels of topoisomerase I mRNA or from alterations in enzyme activity. Using DNA-mediated complementation of the sca299 mutant phenotype, the scaA+ gene was cloned. This gene encodes a 594-amino acid product; moderate structural similarity suggests that the scaA gene product may be related to the human nibrin gene which encodes a product involved in DNA double-strand break repair. Strains disrupted in the scaA gene were sensitive to the anti-topoisomerase I agent berberine, the DNA crosslinking agents mitomycin C and cis-platinum, and also to t-butyl hydroperoxide, which is an inducer of oxidative stress.


Assuntos
Aspergillus nidulans/genética , Camptotecina/farmacologia , Dano ao DNA , Reparo do DNA , Inibidores Enzimáticos/farmacologia , Proteínas Fúngicas/genética , Inibidores da Topoisomerase I , Sequência de Aminoácidos , Animais , Aspergillus nidulans/efeitos dos fármacos , Sequência de Bases , Clonagem Molecular , DNA Fúngico , Proteínas Fúngicas/fisiologia , Genes Fúngicos , Humanos , Camundongos , Mitose/efeitos dos fármacos , Dados de Sequência Molecular , Mutação , Homologia de Sequência de Aminoácidos
9.
Arq Bras Cardiol ; 75(2): 115-24, 2000 Aug.
Artigo em Inglês, Português | MEDLINE | ID: mdl-10983028

RESUMO

OBJECTIVE: To determine in arrhythmogenic right ventricular cardiomyopathy the value of QT interval dispersion for identifying the induction of sustained ventricular tachycardia in the electrophysiological study or the risk of sudden cardiac death. METHODS: We assessed QT interval dispersion in the 12-lead electrocardiogram of 26 patients with arrhythmogenic right ventricular cardiomyopathy. We analyzed its association with sustained ventricular tachycardia and sudden cardiac death, and in 16 controls similar in age and sex. RESULTS: (mean +/- SD). QT interval dispersion: patients = 53.8+/-14.1 ms; control group = 35.0+/-10.6 ms, p = 0.001. Patients with induction of ventricular tachycardia: 52.5+/-13.8 ms; without induction of ventricular tachycardia: 57.5+/-12.8 ms, p =0.420. In a mean follow-up period of 41+/-11 months, five sudden cardiac deaths occurred. QT interval dispersion in this group was 62.0+/-17.8, and in the others it was 51.9+/-12.8 ms, p = 0.852. Using a cutoff > or =60 ms to define an increase in the degree of the QT interval dispersion, we were able to identify patients at risk of sudden cardiac death with a sensitivity of 60%, a specificity of 57%, and positive and negative predictive values of 25% and 85%, respectively. CONCLUSION: Patients with arrhythmogenic right ventricular cardiomyopathy have a significant increase in the degree of QT interval dispersion when compared with the healthy population. However it, did not identify patients with induction of ventricular tachycardia in the electrophysiological study, showing a very low predictive value for defining the risk of sudden cardiac death in the population studied.


Assuntos
Displasia Arritmogênica Ventricular Direita/complicações , Morte Súbita Cardíaca/etiologia , Síndrome do QT Longo/complicações , Adulto , Displasia Arritmogênica Ventricular Direita/diagnóstico , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Taquicardia Ventricular/etiologia
10.
Arq. bras. cardiol ; 71(1): 49-54, jul. 1998. ilus, tab
Artigo em Português | LILACS | ID: lil-234388

RESUMO

OBJETIVO - Avaliar pelo Holter-24h a dinâmica da repolarização ventricular de pacientes com a síndrome congênita do QT longo. MÉTODOS - Foram incluídos seis pacientes, sendo os resultados confrontados com os observados em um grupo controle semelhante em número, idade e sexo. Analisaram-se nas gravaçöes a morfologia da onda T e sua dinâmica, o intervalo QTc médio para as 24h, as relaçöes entre QT e ciclo cardíaco, a variabilidade do QTc das 24h, bem como a sua dispersão (diferença entre o maior e menor QTc observado). Todas as variáveis foram definidas a partir da medida do intervalo QT obtida no 1§ minuto de cada hora da gravação. RESULTADOS - Alteraçöes morfológicas da onda T estiveram presentes em todos os pacientes, observando-se em cindo deles freqüentes episódios de alternância da onda T, achados ausentes no controle. QTc médio para as 24h - controle: 436,1ñ8,9ms; pacientes: 598,2ñ73,8ms (p=0,000). Correlação linear entre QT e ciclo cardíaco - controle: r=0,967; pacientes: r=0,812 (p=0,000). Variabilidade do QTc para as 24h - controle: 14,7ñ2,1ms; pacientes: 36,9ñ17,1ms (p=0,01). Dispersão do QTc - controle: 53,3ñ8,1ms; pacientes: 168,3ñ70,2ms (p=0,000). CONCLUSÄO - Os resultados apresentaram ampla variabiblidade dos intervalos QTc nas 24h, menor adaptabiblidade do intervalo QT às flutuaçöes dos ciclos cardíacos e significativa dispersão da repolarização ventricular nas 24h, confirmando mais uma vez a existência de importante alteração da vulnerabilidade ventricular nesses pacientes.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Adolescente , Síndrome do QT Longo , Eletrocardiografia Ambulatorial , Estudos Multicêntricos como Assunto , Fatores de Tempo
11.
Int J Radiat Oncol Biol Phys ; 40(5): 1213-30, 1998 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9539579

RESUMO

PURPOSE: To verify that optimized dose distributions provided by an intensity-modulated radiation therapy (IMRT) system are delivered accurately to human patients. METHODS AND MATERIALS: Anthropomorphic phantoms are used to measure IMRT doses. Four types of verification are developed for: I) system commissioning with beams optimized to irradiate simulated targets in phantoms, II) plans with patient-optimized beams directed to phantoms simulating the patient, III) patient-phantom hybrid plans with patient-optimized beams calculated in phantom without further optimization, and IV) in vivo measurements. Phantoms containing dosimeters are irradiated with patient-optimized beams. Films are scanned and data were analyzed with software. Percent difference between verified and planned maximum target doses is defined as "dose discrepancy" (deltavp). The frequency distribution of type II deltavp from 204 verification films of 92 IMRT patients is fit to a Gaussian. Measurements made in vivo yield discrepancies specified as deltaivp, also fit to a Gaussian. RESULTS AND DISCUSSION: Verification methods revealed three systematic errors in plans that were corrected prior to treatment. Values of [deltavp] for verification type I are <2%. Type II verification discrepancies are characterized by a Gaussian fit with a peak 0.2% from the centroid, and 158 [deltavp] <5%. The 46 values of [deltavp] >5% arise from differences between phantom and patient geometry, and from simulation, calculation, and other errors. Values of [deltavp] for verification III are less than half of the values of [deltavp] for verification II. A Gaussian fit of deltaivp from verification IV shows more discrepancy than the fit of deltavp, attributed to dose gradients in detectors, and exacerbated by immobilization uncertainty. CONCLUSIONS: Dosimetric verification is a critical step in the quality assurance (QA) of IMRT. Hybrid Verification III is suggested as a preliminary quality standard for IMRT.


Assuntos
Imagens de Fantasmas , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Neoplasias Encefálicas/cirurgia , Humanos , Modelos Teóricos , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/normas , Tomografia Computadorizada por Raios X
12.
Rev. SOCERJ ; 11(2): 69-74, abr. 1998. graf
Artigo em Português | LILACS | ID: lil-248186

RESUMO

No presente artigo, os autores fazem uma revisäo da metodologia e da importância clínica de alguns novos métodos de análise da repolarizaçäo ventricular pelo eletrocardiograma de superfície ou utilizando a eletrocardiograma de superfície ou utilizando a eletrocardiografia dinâmica pelo sistema Holter. Incluem,no estudo, a análise da dispersäo temporal da repolarizaçäo ventricular, a variabilidade dos intervalos Qt e a alternância elétrica da onda T. Acentuam a importância e as limitaçöes desses métodos na estratificaçäo de risco arritmogênico em algumas cardiopatias e as perspectivas dos mesmos com os estudos em andamento que tentam desenvolver programas e algoritmos que permitam uma correta determinaçäo automática das variáveis envolvidas


Assuntos
Humanos , Cardiopatias/complicações , Síndrome do QT Longo/mortalidade
13.
Rev. SOCERJ ; 11(2): 94-104, abr. 1998. ilus
Artigo em Português | LILACS | ID: lil-248190

RESUMO

No presente artigo os autores fazem uma breve revisão da clínica dos mecanismos eletrofisiológicos do Flutter e Fibrilação atriais. Procuram de forma sucinta fazer uma atualização terapêutica, uma vez que o grande avanço ocorrido na última década na área de eletrofisiologia clínica possibilitou não apenas um melhor conhecimento dos mecanismos das arritmias cardíacas e o mecanismo de ação das drogas antiarrítmicas, como também o tratamento não farmacológico das mesmas. Nesta revisão, os autores procuram abranger o tratamento farmacológico das arritmias, a indicação atual para a anticoagulação na prevenção dos fenômenos tromboembólicos e avaliar as indicaçöes atuais, sucessos e limitaçöes da terapia não farmacológica dos distúrbios do ritmo em questão.


Assuntos
Humanos , Masculino , Feminino , Adulto , Flutter Atrial/complicações , Flutter Atrial/história , Flutter Atrial/terapia , Fibrilação Atrial/história , Fibrilação Atrial/terapia , Doença Aguda , Idoso de 80 Anos ou mais , Prevalência , Tromboembolia/prevenção & controle
15.
Cancer ; 77(9): 1873-6, 1996 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-8646687

RESUMO

BACKGROUND: Between April 1963 and July 1991, 18 patients were treated for spermatic cord sarcoma. The histologic subtype distribution was: 7 leiomyosarcoma, 7 liposarcoma, 2 malignant fibrous histiocytoma, and 1 mesothelioma. METHODS: All patients underwent surgical resection: 16 radical orchiectomy and local excision. Nine were treated with orchiectomy alone, and 9 received adjuvant radiation. The radiation fields encompassed the ipsilateral iliac and inguinal lymph nodes, vas deferens, and hemiscrotum in 7 patients, and iliac and inguinal lymph nodes in 2 patients. RESULTS: The actuarial 5 and 8-year disease free survivals for the 18 patients were 77% and 58%, with an overall survival of 78% and 70%, respectively. The 5 and 8-year locoregional control rates were 82% and 61%. Five of 9 patients treated with surgery alone developed locoregional recurrence while none of the nine who had adjuvant radiation relapsed. The median follow-up for the irradiated group, however, was shorter (123 vs 63 months) and staging studies more complete. These potential biases are discussed. CONCLUSION: In this series, relapse was common after orchiectomy alone. Adjuvant radiation therapy may reduce the incidence of locoregional failure.


Assuntos
Neoplasias dos Genitais Masculinos/cirurgia , Sarcoma/cirurgia , Cordão Espermático/patologia , Análise Atuarial , Adolescente , Adulto , Idoso , Intervalo Livre de Doença , Seguimentos , Neoplasias dos Genitais Masculinos/radioterapia , Histiocitoma Fibroso Benigno/radioterapia , Histiocitoma Fibroso Benigno/cirurgia , Humanos , Leiomiossarcoma/radioterapia , Leiomiossarcoma/cirurgia , Lipossarcoma/radioterapia , Lipossarcoma/cirurgia , Linfonodos/efeitos da radiação , Masculino , Mesotelioma/radioterapia , Mesotelioma/cirurgia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Orquiectomia , Radioterapia Adjuvante , Sarcoma/radioterapia , Escroto/efeitos da radiação , Taxa de Sobrevida , Ducto Deferente/efeitos da radiação
16.
Arq. bras. cardiol ; 66(supl.1): 39-44, mar. 1996. ilus
Artigo em Português | LILACS | ID: lil-165623

RESUMO

Estudos eletrofisiológicos têm comprovado a existência de vias acessórias atípicas que apresentam características funcionais semelhantes ao nó atrioventricular (AV), ou seja, propriedade de conduçäo decremental. Diferente das vias anômalas convencionais, nas quais a conduçào anterógrada e/ou retrógrada se faz de maira rápida, essas vias conduzem o estímulo elétrico de forma lenta. A presença no circuito reentrante de duas estrutras de conduçäo lenta do tipo nodal AV permite, por vezes, a manutençäoa taquiarritmia originando as formas permanentes ou incessante. Seräo revisadas as vias anômalas de conduçäo decremental anterógradas e retrógradas, apresentando o estado de arte da técnica de ablaçäo com radiofrequência (RF), em um grupo de pacientes submetidos ao procedimento em nossa institutiçäo.


Assuntos
Taquicardia por Reentrada no Nó Atrioventricular/congênito
17.
Int J Radiat Oncol Biol Phys ; 33(3): 579-84, 1995 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-7558946

RESUMO

PURPOSE: To determine the patterns of failure and outcome following relapse of chordomas of the base of skull and cervical spine. METHODS AND MATERIALS: Between November 1975 and October 1993, 204 patients were treated for chordoma of the base of skull or cervical spine, of which 63 have developed relapse. These 63 patients constitute the main focus of this study. Forty-five patients presented with base of skull and 18 with cervical spine tumors. All patients received combined proton and photon beam radiation. The median prescribed dose was 70.1 cobalt-Gray equivalent (CGE) (range 66.6-77.4). There were 25 males and 38 females, with a median age of 41 years (range 7-66). Median follow-up was 54 months (range 8-158). RESULTS: Sixty-three of the 204 patients treated (31%) had treatment failure. Among the 63 patients who relapsed, 60 (95%) experienced local recurrence, and in 49 patients (78%), this was the only site of failure. Two of 63 patients (3%) developed regional lymph node relapse and 3 of 63 (5%) developed surgical pathway recurrence (1 left neck, 1 palate and 1 nasal cavity). Thirteen of 204 patients relapsed in distant sites, accounting for 20% (13 of 63) of all patients with recurrence in this series. The most common metastatic sites were lungs and bones presenting in 7 of 13 and 6 of 13 patients, respectively. Only 2 of 13 patients failed with isolated distant metastasis. The actuarial 3- and 5-year survival rates after local relapse (60 patients) were 44 and 5%, respectively. Following distant failure (13 patients), the 3- and 5-year survival rates were 25 and 12%, respectively. After any relapse (63 patients) the corresponding survival rates were 43 and 7%. Following local relapse, 49 of 60 patients underwent salvage therapy consisting of subtotal resection in most patients (46 of 49). The remaining 11 of 60 patients received supportive care only. Salvage therapy resulted in stable or improved status without subsequent disease progression in 26 of 49 (53%), and progressive disease in 16 of 49 patients (33%). The actuarial 2- and 5-year overall survival rates following relapse for the 49 patients who underwent salvage treatment were 63 and 6%, which favorably compared to the 2-year survival rate of 21% for those who received supportive care only (p = 0.001). CONCLUSION: Local relapse is the predominant type of treatment failure for chordomas of the base of skull and cervical spine. Salvage treatment may relieve symptoms; however, most patients will ultimately succumb to their disease. Poor long-term survival rates following relapse emphasize the importance of a combined treatment approach with experienced surgeons and radiation oncologists at the time of primary treatment. For most patients, only permanent local tumor control will offer a chance of cure.


Assuntos
Vértebras Cervicais , Cordoma/radioterapia , Neoplasias Cranianas/radioterapia , Neoplasias da Coluna Vertebral/radioterapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/secundário , Criança , Cordoma/tratamento farmacológico , Cordoma/secundário , Cordoma/cirurgia , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/cirurgia , Terapia de Salvação , Neoplasias Cranianas/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Análise de Sobrevida , Falha de Tratamento
18.
Arq Bras Cardiol ; 64(4): 323-30, 1995 Apr.
Artigo em Português | MEDLINE | ID: mdl-7495390

RESUMO

PURPOSE--To present initial experience on radiofrequency (RF) ablation of atrial flutter (AFL) guided by anatomic and electrophysiologic parameters. METHODS--Eight patients (six males), mean-age of 42 +/- 17.5 years with chronic type I AFL (mean cycle length of 251 +/- 14.3 msec, range 240 to 280 msec) were undergone to RF catheter ablation applied between inferior vena cava (IVC) and tricuspid annulus (TA). Two had persistent and two the paroxysmal form. Two had surgical corrected congenital heart disease (atrial septal defect in 2 and ventricular septal defect in 1). Four had systolic dysfunction and 2, an atrial tachycardia associated with the AFL. RESULTS--Areas of slow conduction represented by fractionated potentials were recorded between IVC and TA in all patients. RF ablation was successful in 8/8 patients (100%). The mean number of RF applications was 9.2 +/- 6.2 (4-24). The successful ablation site was located in the isthmus between IVC and TA in seven patients and in the lateral wall in the patient with ASD. Successful sites had an early atrial activation preceding the atrial electrogram (range from -65 to -82 ms). In one patient the RF energy was successfully delivered between the atriotomy scar (AS) and IVC. After three months follow-up six remained free of recurrent AFL. One pt had type 1 AFL recurrence and one with ASD had a type II AFL. The Type II AFL was successfully ablated between AS and IVC. CONCLUSION--Fractionated potentials were commonly observed between IVC and T; AFL ablation can be guided by anatomic landmarks or electrophysiologic parameters; electrograms recorded at successful sites were early and never fractionated; the long-term evaluation must be analyzed prospectively.


Assuntos
Flutter Atrial/cirurgia , Ablação por Cateter/métodos , Adulto , Flutter Atrial/fisiopatologia , Criança , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Reoperação , Valva Tricúspide/cirurgia , Veia Cava Inferior/cirurgia
19.
Rev. SOCERJ ; 7(2): 70-7, abr.-jun. 1994. ilus
Artigo em Português | LILACS | ID: lil-165710

RESUMO

Problema: Vias anômalas com período refratário anterógrado curto, representar um risco de morte súbita em pacientes portadores de Síndrome de Wolff-Parkinson-White. Métodos: De um total de 120 pacientes (pts) portadores de uma conexäo anômala (CA) atrioventricular, 42 pts foram submetidos a ablaçäo com radiofrequência. Desse total, quatro pts do sexo masculino (Grupo 1) com idade média de 37 +/_ 8,6 (27-50) anos que evoluíram para parada cardio-respiratória (PCR) após episódio de fibrilaçäo atrial A) com respostas ventricular rápida foram comparados com 31 pts portadores de vias anômalas manifestas (Grupo 2). Os episódios de PCR ocorreram por administraçäo indevida de verapamil venoso ou betabloqueador oral durante as crises de FA. Após recuperaçäo do quadro de PCR os pts foram submetidos a estudo eletrofisiológico e concominante ablaçäo via cateter com radiofrequência. Foram comparadas também os pacientes do grupo 1 com os pacientes do grupo 2 apresentaram crise de FA porém sem PCR (Grupo 3). Reutados: Todos os pacientes apresentaram pelo menos um episódio de FA durante o procedimento e necessitam cardioversäo elétrica. A médida da capacidade de conduçäo da CA avaliada pelo menor intervalo RR durante FA induzida no grupo(1) de PCR variou de 185 +/_ 25 ms (n=4) contra 253 +/_ 55 ms (n=31) no grupo 2 (p=0,018). A média do menor intervalo RR no grupo 1 variou de 185 +/_ 25 ms contra 212 +/_ 26 ms (n=9) no grupo 3 (p=0,058). Três pacientes com PCR apresentam uma localizaçäo da via anômala em pardepostero-lateral esquerda e um em parede anterolateral esquerda. A ablaçäo foi realizada em ritmo sinusal em pacientes e durante FA em 1 (4 episódios de FA durante a ablaçäo). Durante o FA o parâmetro utilizado para omapeamento foi a presença do eletrograma "V" mais precoce. Os pacientes do G1 encontram-se assintomáticos após um acompanhamento médio de 10,5 meses. Conclusäo: 1-Pacientes portadores de síndrome de WPW e FA com período refratário efetivo curto devem ser encaminhados precocemente para ablaäo.2-Todo paciente com WPW deve ser comunicado da contra-indicaçäo do uso de drogas de açäo exclusivamente no nó. AV. 3-A ablaçäo pode serf realizada durante FA baseando-se na presença da depolarizaçäo "V" endocavitária mais precose em relaçào ao complexo "QRS" do ECG de superfície.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Síndrome de Wolff-Parkinson-White
20.
Int J Radiat Oncol Biol Phys ; 27(3): 553-60, 1993 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-8226148

RESUMO

PURPOSE: Breast-conserving surgery and definitive radiation as an alternative to mastectomy is a well-accepted practice. However, there is limited information addressing the extent of surgical resection. The purpose of this study is to compare the outcome of patients treated with local excision or quadrantectomy, followed by definitive radiation with particular emphasis on local-regional control and cosmetic results. METHODS AND MATERIALS: Between 1978 and 1989, 425 patients with Stage I and II breast cancer underwent conservative surgery followed by definitive radiation. Fifty-four patients had a local excision and 371 had a quadrantectomy. Median follow-up was 42 months. Axillary dissection (levels I/II) was performed in 317 patients, and of these 126 patients had positive axillary lymph nodes. Radiation consisted of 4500-5000 cGy to the breast with Co60 or 4 MV photons, plus a boost to the tumor site (356/425 patients) for a total dose of 6000-6500 cGy. Treatment of the regional lymph nodes was given to patients with undissected or inadequately dissected axillas and usually to patients with multiple positive lymph nodes. Of the patients with positive lymph nodes, 46% received systemic chemotherapy. RESULTS: The 5-year actuarial freedom from local-regional recurrence rates for patients treated with local excision and quadrantectomy followed by definitive radiation were 92% and 93%, respectively (p = 0.7). The 5-year actuarial survival rates for local excision and quadrantectomy were as follows: overall (83% and 82%; p = 0.7), cause-specific disease-free (74% and 71%; p = 0.9), and distant disease-free (82% and 76%, p = 0.4). Estimated 10-year results are also presented. Cosmetic analysis required a minimum follow-up of 5 years. In the local excision, 77% of the patients had excellent-good result, compared to 53% following quadrantectomy (p = 0.03). Excluding patients who received chemotherapy, the excellent-good scores were 76% and 57%, respectively (p = 0.1). The most unfavorable cosmetic results were associated with quadrantectomy followed by radiation with boost dose and chemotherapy, excellent-good in 22%. CONCLUSION: Conservative surgery consisting of local excision or quadrantectomy resulted in comparable local-regional control, overall, disease-free and distant disease-free survival, although cosmetic results were superior in the local excision group.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia Segmentar , Adulto , Idoso , Neoplasias da Mama/mortalidade , Neoplasias da Mama/radioterapia , Quimioterapia Adjuvante , Terapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Taxa de Sobrevida
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