Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Br J Surg ; 103(7): 871-80, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27029597

RESUMO

BACKGROUND: Liver resection is a potentially curative approach for hepatocellular carcinoma (HCC). Laparoscopic liver resections may reduce complication rates, especially in patients with cirrhosis. The aim of this study was to compare the results of laparoscopic liver resection with those of open liver resection for HCC. METHODS: Patients with cirrhosis who underwent minor liver resections for HCC from 2006 to 2013 were identified retrospectively from a prospective database according to the technique adopted (laparoscopic or open). Short- and long-term outcomes were compared between the two groups before and after 1 : 1 propensity score matching. RESULTS: A total of 269 patients were considered: 226 who underwent open liver resection and 43 who had a laparoscopic procedure. The two groups differed at baseline in terms of median age, sex, performance status, tumour location and type of resection. After propensity score matching, two comparable groups of 43 patients each were obtained. Intraoperative bleeding, margin clearance and operative mortality were similar in the two groups, whereas complication rates were lower (49 versus 19 per cent in open versus laparoscopic groups respectively; P = 0·004) and median hospital stay was shorter (8 versus 5 days; P < 0·001) in the laparoscopic group. On multivariable logistic regression analysis, the only independent factor that reduced the risk of postoperative complications was the use of laparoscopy (odds ratio 0·12, 95 per cent c.i. 0·03 to 0·55; P = 0·006). Median overall survival was 57·8 months in the open group and 48·8 months in the laparoscopic group (P = 0·802). Median disease-free survival was 31·7 and 25·5 months respectively (P = 0·990). CONCLUSION: In comparison with the open approach, laparoscopic minor liver resections for HCC improved short-term outcomes, with similar survival results.


Assuntos
Carcinoma Hepatocelular/mortalidade , Carcinoma Hepatocelular/cirurgia , Hepatectomia/métodos , Laparoscopia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/patologia , Intervalo Livre de Doença , Feminino , Humanos , Itália/epidemiologia , Tempo de Internação/estatística & dados numéricos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Pontuação de Propensão , Estudos Retrospectivos
2.
Eur J Nucl Med Mol Imaging ; 42(11): 1718-1738, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26112387

RESUMO

PURPOSE: The aim of this study was to optimize the dosimetric approach and to review the absorbed doses delivered, taking into account radiobiology, in order to identify the optimal methodology for an individualized treatment planning strategy based on (99m)Tc-macroaggregated albumin (MAA) single photon emission computed tomography (SPECT) images. METHODS: We performed retrospective dosimetry of the standard TheraSphere® treatment on 52 intermediate (n = 17) and advanced (i.e. portal vein thrombosis, n = 35) hepatocarcinoma patients with tumour burden < 50% and without obstruction of the main portal vein trunk. Response was monitored with the densitometric radiological criterion (European Association for the Study of the Liver) and treatment-related liver decompensation was defined ad hoc with a time cut-off of 6 months. Adverse events clearly attributable to disease progression or other causes were not attributed to treatment. Voxel dosimetry was performed with the local deposition method on (99m)Tc-MAA SPECT images. The reconstruction protocol was optimized. Concordance of (99m)Tc-MAA and (90)Y bremsstrahlung microsphere biodistributions was studied in 35 sequential patients. Two segmentation methods were used, based on SPECT alone (home-made code) or on coregistered SPECT/CT images (IMALYTICS™ by Philips). STRATOS™ absorbed dose calculation was validated for (90)Y with a single time point. Radiobiology was used introducing other dosimetric variables besides the mean absorbed dose D: equivalent uniform dose (EUD), biologically effective dose averaged over voxel values (BEDave) and equivalent uniform biologically effective dose (EUBED). Two sets of radiobiological parameters, the first derived from microsphere irradiation and the second from external beam radiotherapy (EBRT), were used. A total of 16 possible methodologies were compared. Tumour control probability (TCP) and normal tissue complication probability (NTCP) were derived. The area under the curve (AUC) of the receiver-operating characteristic (ROC) curve was used as a figure of merit to identify the methodology which gave the best separation in terms of dosimetry between responding and non-responding lesions and liver decompensated vs non-decompensated liver treatment. RESULTS: MAA and (90)Y biodistributions were not different (71% of cases), different in 23% and uncertain in 6%. Response correlated with absorbed dose (Spearman's r from 0.48 to 0.69). Responding vs non-responding lesion absorbed doses were well separated, regardless of the methodology adopted (p = 0.0001, AUC from 0.75 to 0.87). EUBED gave significantly better separation with respect to mean dose (AUC = 0.87 vs 0.80, z = 2.07). Segmentation on SPECT gave better separation than on SPECT/CT. TCP(50%) was at 250 Gy for small lesion volumes (<10 cc) and higher than 1,000 Gy for large lesions (>10 cc). Apparent radiosensitivity values from TCP were around 0.003/Gy, a factor of 3-5 lower than in EBRT, as found by other authors. The dose-rate effect was negligible: a purely linear model can be applied. Toxicity incidence was significantly larger for Child B7 patients (89 vs 14%, p < 0.0001), who were therefore excluded from dose-toxicity analysis. Child A toxic vs non-toxic treatments were significantly separated in terms of dose averaged on whole non-tumoural parenchyma (including non-irradiated regions) with AUC from 0.73 to 0.94. TD50 was ≈ 100 Gy. No methodology was superior to parenchyma mean dose, which therefore can be used for planning, with a limit of TD15 ≈ 75 Gy. CONCLUSION: A dosimetric treatment planning criterion for Child A patients without complete obstruction of the portal vein was developed.


Assuntos
Carcinoma Hepatocelular/terapia , Embolização Terapêutica , Vidro/química , Neoplasias Hepáticas/terapia , Microesferas , Planejamento da Radioterapia Assistida por Computador/métodos , Radioisótopos de Ítrio , Carcinoma Hepatocelular/diagnóstico por imagem , Criança , Relação Dose-Resposta à Radiação , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Medicina de Precisão , Radiobiologia , Radiometria , Estudos Retrospectivos , Agregado de Albumina Marcado com Tecnécio Tc 99m , Tomografia Computadorizada de Emissão de Fóton Único
3.
Q J Nucl Med Mol Imaging ; 56(6): 503-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23358402

RESUMO

AIM: Our goal was to limit liver toxicity and to obtain good efficacy by developing a dosimetric treatment planning strategy. While several dosimetric evaluations are reported in literature, the main problem of the safety of the treatment is rarely addressed. Our work is the first proposal of a treatment planning method for glass spheres, including both liver toxicity and efficacy issues. METHODS: Fifty-two patients (series 1) had been treated for intermediated/advanced hepatocellular carcinoma (HCC) with glass spheres, according to the Therasphere® prescription of 120 Gy averaged on the injected lobe. They were retrospectively evaluated with voxel dosimetry, adopting the local deposition hypothesis. Regions of interest on tumor and non tumor parenchyma were drawn to determine the parenchyma absorbed dose, averaged also on non irradiated voxels, excluding tumor voxels. The relationship between the mean non tumoral parenchyma absorbed dose D and observed liver decompensation was analyzed. RESULTS: Basal Child-Pugh strongly affected the toxicity incidence, which was 22% for A5, 57% for A6, 89% for B7 patients. Restricting the analysis to our numerically richest class (basal Child-Pugh A5 patients), D median values were significantly different between toxic (median 90 Gy) and non toxic treatments (median 58 Gy) at a Mann-Withney test, (P=0.033). Using D as a marker for toxicity, the separation of the two populations in terms of area under ROC curve was 0.75, with 95% C.I. of [0.55-0.95]. The experimental Normal Tissue Complication Probability (NTCP) curve as a function of D resulted in the following values: 0%, 14%, 40%, 67% for D interval of [0-35] Gy, [35-70] Gy, [70-105] Gy, [105-140] Gy. DISCUSSION: A limit of about 70 Gy for the mean absorbed dose to parenchyma was assumed for A5 patients, corresponding to a 14% risk of liver decompensation. This result is applicable only to our administration conditions: glass spheres after a decay interval of 3.75 days. Different safety limit (40 Gy) are published for resin spheres, characterized by higher number of particle per GBq (more uniform irradiation, bigger biological effect for the same absorbed dose). CONCLUSION: As result of this study we suggest a constraint of about 70 Gy mean absorbed dose to liver non tumoral parenchyma, corresponding to about 15% probability of radioinduced liver decompensation while still aiming at achieving an absorbed of several hundreds of Gy to lesions.


Assuntos
Braquiterapia/métodos , Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Radiometria/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioisótopos de Ítrio/uso terapêutico , Idoso , Carcinoma Hepatocelular/diagnóstico , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico , Masculino , Microesferas , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos/uso terapêutico , Dosagem Radioterapêutica , Estudos Retrospectivos , Resultado do Tratamento
4.
Q J Nucl Med Mol Imaging ; 55(2): 168-97, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21386789

RESUMO

In most centres, the choice of the optimal activity to be administered in selective intra-arterial radioembolization with microspheres is nowadays based on empirical models which do not take into account the evaluation of tumour and non tumour individual absorbed dose, despite plenty of published data which showed that local efficacy is correlated to tumour absorbed dose, and that the mean absorbed dose is a toxicity risk factor. A pitfall of the crudest, empirical tumour involvement method are 20 deaths in a single centre which adopted it to administer the whole liver, or the need of systematic 25% subjective reduction of activity prescribed with body surface area method. In order to develop a possibly safer and more effective strategy based on real individual dosimetry, we examine first external beam liver radiation therapy results. The half century experience has something to be borrowed: the volume effect, according to which the smaller the fraction of the irradiated liver volume, the higher the tolerated dose. Different tolerance for different underlying disease or previous non radiation treatment is to be expected. Radiobiological models experience also has to be inherited, but not their dose reference values. Then we report the published dosimetric experience about (90)Y microsphere radioembolization of primary and metastatic liver tumours. In addition we also present original data from our growing preliminary experience of more refined (99m)Tc MAA SPECT based calculations in hepatocarcinoma patients. This overcame the mean dose approach in favour of the evaluation of dose distribution at voxel level. An insight into dosimetry issues at microscopic level (lobule level) is also provided, from which the different radiobiological behaviour between resin and glass spheres can be understood. For tumour treatment, an attenuation corrected (99m)Tc- SPECT based treatment planning strategy can be proposed, although quantitative efficacy thresholds should be differentiated according to the kind of pathology and previous treatment. For non tumour liver parenchyma, data in favour of a relationship between absorbed dose and dangerous effects are encouraging. Unfortunately in hepato-cellular carcinoma, some confounding factors may hamper the adequate estimation of the risk of toxicity. First there is a lack of consensus about the exact definition of toxicity after (90)Y microsphere radioembolization. Second, for HCC patients, progression of both cancer and cirrhosis can simulate a radioinduced toxicity, making the analysis more complex.


Assuntos
Neoplasias Hepáticas/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Radioisótopos de Ítrio/administração & dosagem , Radioisótopos de Ítrio/uso terapêutico , Academias e Institutos , Carcinoma Hepatocelular/radioterapia , Relação Dose-Resposta à Radiação , Embolização Terapêutica/métodos , Humanos , Itália , Fígado/lesões , Fígado/efeitos da radiação , Microesferas , Modelos Biológicos , Pneumonite por Radiação/etiologia , Radiobiologia , Radioisótopos de Ítrio/efeitos adversos
5.
Acta Diabetol ; 39(4): 203-8, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12486494

RESUMO

Cirrhotic patients after liver transplantation show a near-normal glucose homeostasis when in stable condition. In contrast, the basal and insulin-mediated whole-body protein metabolism remain altered several years after the graft. To examine whether the persisting defect of protein metabolism was due to the muscle, 7 non-diabetic liver-transplanted patients in stable condition were studied by means of the catheterization of the brachial artery and the deep forearm vein (to measure the balance across the forearm) and the infusion of labelled leucine and phenylalanine associated with indirect calorimetry. Whole-body proteolysis (as determined by endogenous leucine flux, ELF), protein synthesis (from non-oxidative leucine disposal, NOLD) and leucine oxidation (LO) were reduced in comparison to previously obtained values in a normal population. Insulin infusion (while maintaining euglycemia) induced a not significant variation of forearm phenylalanine Ra (24.4-->16.5 micromol/100 ml forearm min(-1); proteolysis) and Rd (18.5-->19.7; protein synthesis). In contrast, the whole-body insulin-dependent inhibitions of ELF (31.5-->21.8 micromol/m(2) min) and NOLD (27.3-->18.4) were impaired with respect to a normal population. On the basis of the present results, we conclude that skeletal muscle is not responsible for the alterations of leucine metabolism persisting after liver transplantation. By exclusion, this points to the liver as the major determinant of the leucine metabolism defect.


Assuntos
Insulina/farmacologia , Transplante de Fígado , Proteínas Musculares/metabolismo , Período Pós-Prandial , Antebraço , Humanos , Leucina/metabolismo , Fígado/metabolismo , Cirrose Hepática/cirurgia , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Oxirredução , Peptídeo Hidrolases/metabolismo , Fenilalanina/metabolismo
10.
J Hypertens ; 19(1): 143-8, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11204295

RESUMO

OBJECTIVE: To verify in a unitary view whether autonomic control of heart rate and cardiac structure and function are modified early in offspring of hypertensive families. METHODS AND RESULTS: We selected 87 age- and sex-matched young normotensive subjects with (n = 45) and without (n = 42) a family history of hypertension who underwent evaluations of arterial pressure, time-domain parameters of autonomic heart rate control (24-h ECG monitoring), spectral baroreflex sensitivity, left ventricular geometry and function (echo-Doppler) and plasma brain natriuretic peptide levels (BNP). The group with a family history of hypertension significantly differed from their counterparts for systolic pressure (119 +/- 11 versus 114 +/- 9 mmHg, P< 0.05), heart rate (RR interval, 766 +/- 64 versus 810 +/- 93 ms, P< 0.05), heart rate variability [the standard deviation of normal RR intervals (SDNN), 147 +/- 29 versus 171 +/- 33 ms, P < 0.051, diastolic function (isovolumetric relaxation time, 65 +/- 9 versus 60 +/- 8 ms, P< 0.05) and BNP (23 +/- 13 versus 37 +/- 10 pg/ml, P< 0.05). Baroreflex sensitivity values did not differ between the two groups. When gender was considered, all the above-mentioned measures, as well as baroreflex sensitivity, were significantly different between males with and without a family history of hypertension but not between females, except for BNP, which was lower in males and females with a history of hypertension (males, 24 +/- 11 versus 38 +/- 8 pg/ml, P< 0.01; females 21 +/- 14 versus 36 +/- 13 pg/ml, P < 0.05). CONCLUSIONS: Male, but not female, hypertensive offspring have modified diastolic function and autonomic control of heart rate; BNP is the only parameter able to characterize hypertensive offspring independently from the influence of gender. This provides the hypothesis that the impaired production of this hormone could play a primary role in the pre-hypertensive state.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Predisposição Genética para Doença , Frequência Cardíaca , Ventrículos do Coração/fisiopatologia , Hipertensão/fisiopatologia , Peptídeo Natriurético Encefálico/sangue , Função Ventricular Esquerda , Adolescente , Adulto , Fatores Etários , Barorreflexo , Diástole , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Frequência Cardíaca/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/inervação , Humanos , Hipertensão/sangue , Hipertensão/genética , Masculino , Prognóstico , Curva ROC , Estudos Retrospectivos , Fatores Sexuais , Função Ventricular Esquerda/fisiologia
11.
Hepatology ; 31(3): 694-703, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10706560

RESUMO

Diabetes mellitus frequently complicates cirrhosis but the pathogenic mechanisms are unknown. To assess the contribution of reduced insulin action and secretion, 24 cirrhotic-diabetic patients waiting for liver transplant because of an unresectable hepatocarcinoma underwent an oral glucose tolerance test (OGTT) to assess the beta-cell function and an insulin clamp combined with [3-(3)H]glucose infusion to measure whole body glucose metabolism before and 2 years after the transplant. Seven cirrhotic nondiabetic patients, 11 patients with chronic uveitis on similar immunosuppressive therapy, and 7 healthy subjects served as control groups. Cirrhotic patients showed a profound insulin resistance, and diabetics in addition also showed increased endogenous glucose production (P <.05) and insulin deficiency during the OGTT (P <.05). Liver transplantation normalized endogenous glucose production and insulin sensitivity but failed to cure diabetes in 8 of the 24 patients because a markedly low insulin response during the OGTT. Age, body mass index, family history of diabetes, immunosuppressive drugs, and pathogenesis of cirrhosis did not predict in whom liver transplant was going to cure diabetes. On the contrary, a reduced secretory response characterized the patients in whom the transplant would not be curative. In summary, insulin resistance was a primary event complicating cirrhosis but additional beta-cell secretory defects were crucial for development of diabetes. Liver transplantation, lessening insulin resistance, cured hepatogenous diabetes in 67% of cirrhotic-diabetic patients; nevertheless 33% were still diabetics because the persistence of a reduced beta-cell function, which makes these patients eventually eligible for combined islet transplantation.


Assuntos
Carcinoma Hepatocelular/complicações , Complicações do Diabetes , Insulina/sangue , Cirrose Hepática/complicações , Neoplasias Hepáticas/complicações , Transplante de Fígado , Glicemia/metabolismo , Índice de Massa Corporal , Peptídeo C/sangue , Carcinoma Hepatocelular/terapia , Diabetes Mellitus/genética , Diabetes Mellitus/terapia , Seguimentos , Técnica Clamp de Glucose , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Insulina/uso terapêutico , Resistência à Insulina , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Cirrose Hepática/terapia , Neoplasias Hepáticas/terapia , Pessoa de Meia-Idade
12.
Proc Natl Acad Sci U S A ; 95(5): 2615-20, 1998 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-9482935

RESUMO

Aldolase C is regarded as the brain-specific form of fructose-1, 6-bisphosphate aldolase whereas aldolase A is regarded as muscle-specific. In situ hybridization of mouse central nervous system using isozyme-specific probes revealed that aldolase A and C are expressed in complementary cell types. With the exception of cerebellar Purkinje cells, aldolase A mRNA is found in neurons; aldolase C message is detected in astrocytes, some cells of the pia mater, and Purkinje cells. We isolated aldolase C genomic clones that span the entire protein coding region from 1.5 kb 5' to the transcription start site to 0.5 kb 3' to the end of the last exon. The bacterial gene, lacZ, was inserted in two different locations and the constructs tested in transgenic mice. When the protein coding sequences were replaced with lacZ, three of five transgenic lines expressed beta-galactosidase only in cells of the pia mater; one line also expressed in astrocyte-like cells. When lacZ was inserted into the final exon (and all structural gene sequences were retained) transgene expression was observed in astrocytes in all regions of the central nervous system as well as in pial cells. Thus, with the exception of Purkinje cell expression, the behavior of the full-length transgene mimics the endogenous aldolase C gene. The results with the shorter transgene suggest that additional enhancer elements exist within the intragenic sequences. The absence of Purkinje cell staining suggests that the cis elements required for this expression must be located outside of the sequences used in this study.


Assuntos
Encéfalo/enzimologia , Frutose-Bifosfato Aldolase/genética , Regulação Enzimológica da Expressão Gênica , Óperon Lac , Proteínas do Tecido Nervoso/genética , beta-Galactosidase/biossíntese , Animais , Encéfalo/citologia , Éxons , Frutose-Bifosfato Aldolase/biossíntese , Biblioteca Genômica , Hibridização In Situ , Isoenzimas/biossíntese , Isoenzimas/genética , Camundongos , Camundongos Endogâmicos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/biossíntese , Neurônios/enzimologia , Especificidade de Órgãos , Reação em Cadeia da Polimerase , RNA Mensageiro/biossíntese , Transcrição Gênica
13.
Med Sci Sports Exerc ; 29(6): 769-74, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9219204

RESUMO

This was a randomized, cross-over experiment designed to determine which beta-adrenergic receptors, beta 1, beta 2, or both, regulate metabolic rate in humans. All subjects (3 women, 4 men) were administered a 7-d therapeutic dose of a selective beta 1-antagonist (atenolol 50 mg BID), a combined beta 1, beta 2-antagonist (propranolol 80 mg BID), and a placebo control (BID). Indirect calorimetry was determined before and after 1 h of submaximal exercise. Exercise was performed at 50% of the trial specific VO2peak because maximal exercise was significantly decreased in the presence of the nonselective beta 1, beta 2-antagonist (VO2peak placebo: 44.90 +/- 4.40 mL.kg-1.min-1 vs beta 1, beta 2-antagonism: 39.20 +/- 3.00 mL.kg-1.min-1; P < 0.05). Both the beta 1 and the combined beta 1, beta 2-adrenoreceptor antagonists reduced resting oxygen consumption to a similar extent (0.247 +/- 0.007 L.min-1 placebo, vs 0.218 +/- 0.007 L.min-1 beta 1-antagonism, vs 0.226 +/- 0.007 L.min-1 beta 1, beta 2-antagonism; P < 0.05). However, the 30-min and 60-min excess post-exercise oxygen consumption (mean EPOC) remained unchanged. It is concluded that the beta 1-receptors are regulating the effects of the sympathetic nervous system on resting but not exercise recovery metabolic rate. These metabolic side effects may suggest that changes need to be made in the nutritional requirements of patients using beta-adrenergic antagonists.


Assuntos
Antagonistas Adrenérgicos beta/farmacologia , Atenolol/farmacologia , Exercício Físico/fisiologia , Consumo de Oxigênio/fisiologia , Propranolol/farmacologia , Receptores Adrenérgicos beta 1/fisiologia , Adulto , Estudos Cross-Over , Teste de Esforço , Feminino , Humanos , Masculino , Sistema Nervoso Simpático/fisiologia
16.
AACN Clin Issues ; 6(2): 242-56, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7743427

RESUMO

Aggressive nutrition intervention has become an essential component in the therapy of critically ill patients. Early provision of enteral nutrients within 24 hours of injury or surgery appears optimal and is associated with benefits such as a reduction in septic complications, a decrease in the hypermetabolic response to severe burn injury, and improved wound healing. Early enteral nutrient administration has a significant impact on preserving gastrointestinal integrity and barrier function and maintaining intestinal immunologic defenses, which may have a role in decreasing infectious outcomes in critically ill patients. Establishing an enteral access becomes a priority with early feeding. Small intestine feeding usually is preferred to gastric nutrient administration, yet some declare biologic superiority with intragastric feedings. The optimal enteral product for use in critically ill patients remains unknown. Key nutrients, such as glutamine, arginine, fiber, and alternative lipids, may have potential benefits and need to be considered when formulating an enteral regimen in this patient population.


Assuntos
Estado Terminal/terapia , Nutrição Enteral/métodos , Nutrição Enteral/enfermagem , Humanos , Fatores de Tempo
17.
Virus Res ; 35(2): 181-92, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7762291

RESUMO

The RNA species synthesized in HPIV-2 infected CV-1 cells were identified and characterized. The largest RNA of approximately 5.5 x 10(6) in molecular weight (MW) based on electrophoretic mobility, was identified as the genomic RNA. The other small RNA species of MWs 2.4 x 10(6), 1.1 x 10(6), 0.77 x 10(6), 0.68 x 10(6) and 0.5 x 10(6) were identified as mRNAs. The five smallest RNAs were also synthesized in vitro and comigrated with RNAs synthesized in virus-infected cells. mRNAs synthesized both in vitro and in virus-infected cells were translated in vitro. NP, P, M and V proteins synthesized in vitro comigrated, when analyzed by SDS-PAGE, with the authentic proteins synthesized in virus-infected cells. Additionally, peptide mapping showed that the NP, P and M proteins synthesized in vitro were indistinguishable from their counterparts synthesized in infected cells. Analysis of the proteins from virions identified L, HN, NP, F (F1, F2), P, M and V proteins as virion structural proteins. Electrophoretic mobility of reduced and nonreduced F proteins was found to be different due to the conformational changes conferred by disulfide bonds.


Assuntos
RNA Viral/biossíntese , Respirovirus/genética , Linhagem Celular , Humanos , Técnicas In Vitro , RNA Mensageiro/biossíntese , Temperatura , Fatores de Tempo , Proteínas Estruturais Virais/genética
18.
Antiviral Res ; 25(3-4): 269-79, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7710273

RESUMO

The effect of 6-diazo-5-oxo-L-norleucine (L-DON), a glutamine analog, on RSV replication was studied. At a concentration of 0.01 mM L-DON, 99% of RSV replication in treated CV-1 cells was inhibited. At this concentration of L-DON, the level of cellular protein synthesis was identical to untreated control cells. Trypan blue staining revealed that all the cells remained viable even at concentrations of L-DON as high as 10 mM. In addition, L-DON added as late as 24 h post infection can effectively suppress viral replication. Analysis of viral mRNA levels by Northern blot revealed that secondary transcription and subsequent steps in the virus life cycle were inhibited. Immunoprecipitation of viral proteins from drug treated or untreated cultures showed that synthesis of all viral proteins was drastically reduced by L-DON, with a slightly greater inhibition of viral glycoproteins. Furthermore, immunofluorescent staining showed that drug treated cells expressed both F and N proteins and that F was inserted into the membrane as the native F protein.


Assuntos
Antivirais/farmacologia , Diazo-Oxo-Norleucina/farmacologia , Vírus Sincicial Respiratório Humano/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos , Linhagem Celular , Humanos , RNA Mensageiro/biossíntese , RNA Viral/biossíntese , Vírus Sincicial Respiratório Humano/fisiologia , Proteínas Virais/biossíntese
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...