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1.
Ann Oncol ; 31(6): 724-744, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32194150

RESUMO

Patients with cancer and with preexisting active autoimmune diseases (ADs) have been excluded from immunotherapy clinical trials because of concerns for high susceptibility to the development of severe adverse events resulting from exacerbation of their preexisting ADs. However, a growing body of evidence indicates that immune-checkpoint inhibitors (ICIs) may be safe and effective in this patient population. However, baseline corticosteroids and other nonselective immunosuppressants appear to negatively impact drug efficacy, whereas retrospective and case report data suggest that use of specific immunosuppressants may not have the same consequences. Therefore, we propose here a two-step strategy. First, to lower the risk of compromising ICI efficacy before their initiation, nonselective immunosuppressants could be replaced by specific selective immunosuppressant drugs following a short rotation phase. Subsequently, combining ICI with the selective immunosuppressant could prevent exacerbation of the AD. For the most common active ADs encountered in the context of cancer, we propose specific algorithms to optimize ICI therapy. These preventive strategies go beyond current practices and recommendations, and should be practiced in ICI-specialized clinics, as these require multidisciplinary teams with extensive knowledge in the field of clinical immunology and oncology. In addition, we challenge the exclusion from ICI therapy for patients with cancer and active ADs and propose the implementation of an international registry to study such novel strategies in a prospective fashion.


Assuntos
Doenças Autoimunes , Neoplasias , Doenças Autoimunes/tratamento farmacológico , Humanos , Inibidores de Checkpoint Imunológico , Neoplasias/tratamento farmacológico , Estudos Prospectivos , Estudos Retrospectivos
2.
Stat Med ; 37(16): 2487-2500, 2018 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-29635789

RESUMO

In stepped-wedge trials (SWTs), the intervention is rolled out in a random order over more than 1 time-period. SWTs are often analysed using mixed-effects models that require strong assumptions and may be inappropriate when the number of clusters is small. We propose a non-parametric within-period method to analyse SWTs. This method estimates the intervention effect by comparing intervention and control conditions in a given period using cluster-level data corresponding to exposure. The within-period intervention effects are combined with an inverse-variance-weighted average, and permutation tests are used. We present an example and, using simulated data, compared the method to (1) a parametric cluster-level within-period method, (2) the most commonly used mixed-effects model, and (3) a more flexible mixed-effects model. We simulated scenarios where period effects were common to all clusters, and when they varied according to a distribution informed by routinely collected health data. The non-parametric within-period method provided unbiased intervention effect estimates with correct confidence-interval coverage for all scenarios. The parametric within-period method produced confidence intervals with low coverage for most scenarios. The mixed-effects models' confidence intervals had low coverage when period effects varied between clusters but had greater power than the non-parametric within-period method when period effects were common to all clusters. The non-parametric within-period method is a robust method for analysing SWT. The method could be used by trial statisticians who want to emphasise that the SWT is a randomised trial, in the common position of being uncertain about whether data will meet the assumptions necessary for mixed-effect models.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Estatísticas não Paramétricas , Análise por Conglomerados , Simulação por Computador , Interpretação Estatística de Dados , Humanos , Fatores de Tempo
3.
Adv Exp Med Biol ; 1074: 265-271, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721952

RESUMO

Leber congenital amaurosis (LCA) encompasses a group of severe inherited retinal dystrophies (IRDs) responsible for early childhood blindness. There are currently 25 genes implicated in the pathogenesis of these diseases, and identification of disease-causing variants will be required for personalised therapies. Whole exome and whole genome sequencing is informative for detecting novel disease-causing genes, whilst next-generation sequencing has excelled at detecting novel variants in known disease-causing genes.A global effort will be required to identify patient populations for early intervention. At the Australian Inherited Retinal Disease Registry and DNA Bank, we seek to identify genetic variants in individuals with IRDs in the Australian population to identify potential candidates for clinical trials, to inform clinical management of patients including reproductive options and to expand existing knowledge of IRDs.Due to the diversity of genes implicated, personalised strategies are likely to be the benchmark for treating these diseases, and a combined approach of different therapies may be optimal in treating some of these diseases.


Assuntos
Amaurose Congênita de Leber/genética , Medicina de Precisão , Aciltransferases/genética , Antígenos de Neoplasias/genética , Austrália/epidemiologia , Proteínas de Ciclo Celular , Proteínas do Citoesqueleto , Análise Mutacional de DNA , Heterogeneidade Genética , Terapia Genética , Vetores Genéticos/uso terapêutico , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Amaurose Congênita de Leber/epidemiologia , Amaurose Congênita de Leber/terapia , Terapia de Alvo Molecular , Proteínas de Neoplasias/genética , Sistema de Registros , Sequenciamento do Exoma , Sequenciamento Completo do Genoma , cis-trans-Isomerases/genética
4.
Eur J Neurol ; 20(9): 1325-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23216520

RESUMO

BACKGROUND AND PURPOSE: Despite advances in the understanding of Huntington's disease (HD), treatment remains symptomatic. Multidisciplinary rehabilitation, however, appears to impact disease progression. Here we show the feasibility, safety and efficacy of a 9-month multidisciplinary rehabilitation programme in a small cohort of patients with early-to-middle-stage HD. METHODS: Twenty patients with HD were assigned to two groups, equally matched for cognitive and motor scores. One group received the intervention, whilst the other served as control. The Unified-Huntington's-Disease-Rating-Scale-Total-Motor-Score was the primary outcome measure. Neurocognitive/psychological tests, body composition, postural stability, strength and quality of life assessments were secondary outcome measures. RESULTS: The intervention reduced motor and postural stability deterioration, with minor improvements in depression, cognition and quality of life. Significant gains were observed for fat-free mass and strength. CONCLUSION: This pilot study suggests that a prolonged multidisciplinary rehabilitation programme in early-to-middle-stage HD is feasible, well-tolerated and associated with therapeutic benefit. Further explorative, larger studies are warranted.


Assuntos
Terapia por Exercício/métodos , Doença de Huntington/reabilitação , Terapia Ocupacional/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Resultado do Tratamento
5.
Res Sq ; 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37398241

RESUMO

Background: There is a need for novel methods to determine preventable causes of racial health disparities. This need has been met with the development of improved methods for mediation modeling. Current mediational analysis methods call for an evaluation of statistical interaction or effect modification between the investigated cause and mediator. For racial disparity, this approach facilitates the estimation of racially specific risks for infant mortality. However, current methods for evaluating multiple interacting mediators are inadequate. The first objective of the study was to compare Bayesian estimation of potential outcomes to other approaches to mediation analysis that included interaction. The second objective was to evaluate three potentially interacting mediators of racial disparity for infant mortality by modeling the large dataset from the National Natality Database using Bayesian estimation of potential outcomes. Methods: A random sample of observations from the 2003 National Natality Database was used to compare the currently promoted methods for mediation modeling. Racial disparity was modeled as a separate function for each of three potential mediators, (i) maternal smoking, (ii) low birth weight and (iii) teenage maternity. As a second objective, direct Bayesian estimation of potential outcomes modeled infant mortality as function of the interactions among the three mediators and race using the full National Natality Database for the years 2016 to 2018. Results: The counterfactual model was inaccurate in estimating the proportion of racial disparity that was attributable to either maternal smoking or teenage maternity. The counterfactual approach did not accurately estimate the probabilities defined by counterfactual definitions. The error was a result of modeling the excess relative risk instead of the risk probabilities. Bayesian approaches did estimate the probabilities of the counterfactual definitions. Results showed that 73% of the racial disparity for infant mortality was attributed to infants born with low birth weight. Conclusions: Bayesian estimation of potential outcomes could evaluate whether proposed public health programs would affect races differently and decisions could include consideration of the causal effect the program may have on racial disparity. The large contribution of low birth weight to racial disparity for infant mortality should be further investigated to identify preventable factors for low birth weight.

6.
Ann Bot ; 110(2): 319-28, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22539540

RESUMO

BACKGROUND AND AIMS: Phosphorus commonly limits crop yield and is frequently applied as fertilizer; however, supplies of quality rock phosphate for fertilizer production are diminishing. Plants have evolved many mechanisms to increase their P-fertilizer use efficiency, and an understanding of these traits could result in improved long-term sustainability of agriculture. Here a mutant population is utilized to assess the impact of root hair length on P acquisition and yield under P-deficient conditions alone or when combined with drought. METHODS: Mutants with various root hair phenotypes were grown in the glasshouse in pots filled with soil representing sufficient and deficient P treatments and, in one experiment, a range of water availability was also imposed. Plants were variously harvested at 7 d, 8 weeks and 14 weeks, and variables including root hair length, rhizosheath weight, biomass, P accumulation and yield were measured. KEY RESULTS: The results confirmed the robustness of the root hair phenotypes in soils and their relationship to rhizosheath production. The data demonstrated that root hair length is important for shoot P accumulation and biomass, while only the presence of root hairs is critical for yield. Root hair presence was also critical for tolerance to extreme combined P deficit and drought stress, with genotypes with no root hairs suffering extreme growth retardation in comparison with those with root hairs. CONCLUSIONS: The results suggest that although root hair length is not important for maintaining yield, the presence of root hairs is implicit to sustainable yield of barley under P-deficient conditions and when combined with extreme drought. Root hairs are a trait that should be maintained in future germplasm.


Assuntos
Hordeum/crescimento & desenvolvimento , Fósforo/deficiência , Raízes de Plantas/crescimento & desenvolvimento , Água/metabolismo , Adaptação Fisiológica/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Secas , Variação Genética , Genótipo , Hordeum/genética , Mutação , Fenótipo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/citologia , Raízes de Plantas/genética
7.
Br J Cancer ; 105(3): 346-52, 2011 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-21750555

RESUMO

BACKGROUND: α(v) integrins are involved in angiogenesis and melanoma tumourigenesis. Intetumumab (CNTO 95) is a fully human anti-α(v)-integrin monoclonal antibody. METHODS: In a multicentre, randomised, phase II study, stage IV melanoma patients were randomised 1:1:1:1 to 1000 mg m(-2) dacarbazine+placebo (n=32), 1000 mg m(-2) dacarbazine+10 mg kg(-1) intetumumab (n=32), 10 mg kg(-1) intetumumab (n=33), or 5 mg kg(-1) intetumumab (n=32) q3w. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), adverse events, and pharmacokinetics. RESULTS: No statistically significant differences in efficacy were observed between groups. In the dacarbazine+placebo, dacarbazine+intetumumab, 10 mg kg(-1) intetumumab, and 5 mg kg(-1) intetumumab groups, median PFS was 1.8, 2.5, 1.4, and 1.4 months; median OS was 8, 11, 15, and 9.8 months; and ORR of complete+partial response was 10, 3, 6, and 0%. Nonlinear intetumumab pharmacokinetics and potential intetumumab-dacarbazine interactions were observed. Transient, asymptomatic, nonrecurring, grade 1-2, uveitic reactions that resolved spontaneously or with topical steroids were seen in 22-30% of intetumumab-treated patients. Low-grade infusion-reaction symptoms (headache, fatigue, nausea, vomiting, fever, chills) were observed, as expected, in 16-73% of dacarbazine-treated patients. No intetumumab-related myelosuppression, laboratory/electrocardiogram abnormalities, or deaths occurred. CONCLUSION: With its favourable safety profile and a nonsignificant trend towards improved OS, intetumumab merits further investigation in advanced melanoma.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Dacarbazina/administração & dosagem , Integrina alfaV/imunologia , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Idoso , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Melanoma/mortalidade , Pessoa de Meia-Idade , Uveíte/induzido quimicamente
8.
Oral Dis ; 17(8): 745-52, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21521419

RESUMO

Many of the target molecules that reside in blood are also present in oral fluids, albeit at lower concentrations. Oral fluids are, however, relatively easy and safe to collect without the need for specialized equipment and training. Thus, oral fluids provide convenient samples for medical diagnostics. Recent advances in lab-on-a-chip technologies have made minute, fully integrated diagnostic systems practical for an assortment of point-of-care tests. Such systems can perform either immunoassays or molecular diagnostics outside centralized laboratories within time periods ranging from minutes to an hour. The article briefly reviews recent advances in devices for point-of-care testing with a focus on work that has been carried out by the authors as part of a NIH program.


Assuntos
Diagnóstico Bucal/instrumentação , Dispositivos Lab-On-A-Chip , Sistemas Automatizados de Assistência Junto ao Leito , Desenho de Equipamento , Líquido do Sulco Gengival/química , Humanos , Imunoensaio/instrumentação , Microfluídica/instrumentação , Técnicas de Diagnóstico Molecular/instrumentação , Saliva/química , Fatores de Tempo
9.
Equine Vet J ; 43(2): 216-22, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21592218

RESUMO

REASONS FOR PERFORMING STUDY: Mechanical characterisation of the high speed gallop has significant importance for animal welfare and basic biology. Kinematic parameters such as the velocity of each foot at contact can inform theories of why animals gallop, and supplant epidemiological investigation into the mechanisms of musculoskeletal injury. OBJECTIVE: To determine the velocity at which the fore and hind hooves of elite galloping horses impact the surface. METHODS: High speed videography was used to measure the horizontal and vertical velocity of the hoof immediately prior to impact, and the subsequent sink (vertical) and slip (horizontal) distances travelled by the hoof into the surface. Horse speed ranged from 11-19 m/s. In total 170 forelimb and 168 hindlimb foot falls from 89 horses were analysed. RESULTS: Horizontal and vertical hoof velocity increased with speed (P<0.001). Horizontal hoof velocity was significantly greater in the hindlimbs compared to the forelimbs (P<0.001) and was greater in the nonlead limbs compared to the lead limbs (P<0.001). Vertical hoof velocity was significantly greater in the lead limb than the nonlead limb (P<0.001). Overall, forelimbs contacted the ground with a more acute velocity vector angle than hindlimbs (P<0.001). Lead limbs contacted the ground at more acute angles than nonlead limbs (P<0.001). Vertical and horizontal velocities were highly correlated to sink and slip distance. CONCLUSION: Hindlimbs impact the surface at higher velocity than forelimbs, which is likely to result in higher peak impact forces in the hindlimbs. This runs counter to the finding of lower incidence of injury in hindlimbs. POTENTIAL RELEVANCE: Explanations consistent with these findings include the hindlimbs more effectively dampening peak impact forces, or that other injury mechanisms, such as limb vibration and limb load at mid stance, play an important role in injury.


Assuntos
Marcha/fisiologia , Cavalos/fisiologia , Animais , Fenômenos Biomecânicos , Membro Anterior/fisiologia , Membro Posterior/fisiologia , Corrida/fisiologia , Gravação em Vídeo
10.
Stat Methods Med Res ; 30(2): 425-439, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32970526

RESUMO

Generalised estimating equations with the sandwich standard-error estimator provide a promising method of analysis for stepped wedge cluster randomised trials. However, they have inflated type-one error when used with a small number of clusters, which is common for stepped wedge cluster randomised trials. We present a large simulation study of binary outcomes comparing bias-corrected standard errors from Fay and Graubard; Mancl and DeRouen; Kauermann and Carroll; Morel, Bokossa, and Neerchal; and Mackinnon and White with an independent and exchangeable working correlation matrix. We constructed 95% confidence intervals using a t-distribution with degrees of freedom including clusters minus parameters (DFC-P), cluster periods minus parameters, and estimators from Fay and Graubard (DFFG), and Pan and Wall. Fay and Graubard and an approximation to Kauermann and Carroll (with simpler matrix inversion) were unbiased in a wide range of scenarios with an independent working correlation matrix and more than 12 clusters. They gave confidence intervals with close to 95% coverage with DFFG with 12 or more clusters, and DFC-P with 18 or more clusters. Both standard errors were conservative with fewer clusters. With an exchangeable working correlation matrix, approximated Kauermann and Carroll and Fay and Graubard had a small degree of under-coverage.


Assuntos
Projetos de Pesquisa , Viés , Análise por Conglomerados , Simulação por Computador , Ensaios Clínicos Controlados Aleatórios como Assunto , Tamanho da Amostra
11.
J Exp Med ; 192(11): 1637-44, 2000 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-11104805

RESUMO

Current strategies for the immunotherapy of melanoma include augmentation of the immune response to tumor antigens represented by melanosomal proteins such as tyrosinase, gp100, and MART-1. The possibility that intentional targeting of tumor antigens representing normal proteins can result in autoimmune toxicity has been postulated but never demonstrated previously in humans. In this study, we describe a patient with metastatic melanoma who developed inflammatory lesions circumscribing pigmented areas of skin after an infusion of MART-1-specific CD8(+) T cell clones. Analysis of the infiltrating lymphocytes in skin and tumor biopsies using T cell-specific peptide-major histocompatibility complex tetramers demonstrated a localized predominance of MART-1-specific CD8(+) T cells (>28% of all CD8 T cells) that was identical to the infused clones (as confirmed by sequencing of the complementarity-determining region 3). In contrast to skin biopsies obtained from the patient before T cell infusion, postinfusion biopsies demonstrated loss of MART-1 expression, evidence of melanocyte damage, and the complete absence of melanocytes in affected regions of the skin. This study provides, for the first time, direct evidence in humans that antigen-specific immunotherapy can target not only antigen-positive tumor cells in vivo but also normal tissues expressing the shared tumor antigen.


Assuntos
Antígenos de Neoplasias/imunologia , Imunoterapia Adotiva/efeitos adversos , Melanócitos/imunologia , Melanoma/terapia , Proteínas de Neoplasias/imunologia , Neoplasias Cutâneas/terapia , Vitiligo/imunologia , Antígenos de Neoplasias/biossíntese , Feminino , Humanos , Imunoterapia Adotiva/métodos , Antígeno MART-1 , Melanócitos/citologia , Melanoma/complicações , Melanoma/imunologia , Melanoma/patologia , Pessoa de Meia-Idade , Proteínas de Neoplasias/biossíntese , Pele/citologia , Pele/imunologia , Pele/patologia , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Linfócitos T Citotóxicos/classificação , Linfócitos T Citotóxicos/imunologia , Vitiligo/etiologia , Vitiligo/patologia
12.
Science ; 211(4489): 1444-5, 1981 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-7466403

RESUMO

Chemical and dermatotoxicological investigations of the natural and processed resin of the Mexican rubber plant, guayule (Parthenium argentatum), has established the presence of a sesquiterpene cinnamic acid ester (guayulin A) that is a potent elicitor of allergic contact dermatitis in experimental animals. The guayule contact allergen is comparable to the poison ivy skin allergens as an elicitor of dermatitis in sensitized guinea pigs.


Assuntos
Alérgenos/isolamento & purificação , Cinamatos/imunologia , Dermatite de Contato/etiologia , Sesquiterpenos/imunologia , Animais , Cinamatos/isolamento & purificação , Cobaias , Extratos Vegetais/análise , Sesquiterpenos/isolamento & purificação
13.
Science ; 194(4263): 428-31, 1976 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-982025

RESUMO

Hybridization analysis of RNA transcripts from HeLa S3 cell chromatin to histone complementary DNA indicates that a chromosomal phosphoprotein fraction activates transcription of histone messenger RNA sequences in vitro with chromatin from a phase in the cell cycle when histone genes are normally silent.


Assuntos
Cromatina/metabolismo , Proteínas Cromossômicas não Histona/farmacologia , Histonas/biossíntese , RNA Mensageiro/biossíntese , Transcrição Gênica/efeitos dos fármacos , Divisão Celular , Genes , Células HeLa , Fosfoproteínas/farmacologia
14.
Science ; 249(4967): 401-3, 1990 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-17755945

RESUMO

The study of magnetic phase transitions in insulating molecular solids provides new insights into mechanisms of magnetic coupling in the solid state and into critical phenomena associated with these transitions. Only a few such materials are known to display cooperative magnetic properties. The use of high-spin molecular components would enhance intermolecular spin-spin interactions and thus a series of chargetransfer (CT) salts have been synthesized that utilize the spin S = 1 molecular cation, [Mn(C(5)(CH(3))(5))(2)](+) (decamethylmanganocenium). The structure and cooperative magnetic behavior of [Mn(C(5)(CH(3))(5))(2)](+)[TCNQ(-) (decamethylmanganocenium 7,7,8,8-tetracyano-p-quinodimethanide) are reported. This salt is a bulk molecular ferromagnet with the highest critical (Curie) temperature (T(c) = 6.2 K) and coercive field (3.6 x 10(3) gauss), yet reported for such a material.

15.
Science ; 241(4871): 1349-52, 1988 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-2457952

RESUMO

Angiogenesis is an important component of organogenesis and wound repair and occurs during the pathology of oncogenesis, atherogenesis, and other disease processes. Thus, it is important to understand the physiological mechanisms that control neovascularization, especially with methods that permit the molecular dissection of the phenomenon in vivo. Heparin-binding growth factor-1 was shown to bind to collagen type I and type IV. When complexed with gelatin, heparin-binding growth factor-1 can induce neovascularization at polypeptide concentrations that are consistent with the biological activity of the mitogen in vitro. The adsorption strategy induces rapid blood vessel formation at and between organ- and tissue-specific sites and permits recovery of the site-specific implant for examination and manipulation by molecular methods.


Assuntos
Substâncias de Crescimento/farmacologia , Heparina/farmacologia , Neovascularização Patológica , Animais , Vasos Sanguíneos/citologia , Colágeno/metabolismo , Matriz Extracelular , Fator 1 de Crescimento de Fibroblastos , Gelatina/metabolismo , Ratos , Tampões Cirúrgicos
16.
J Clin Invest ; 98(6): 1465-70, 1996 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-8823313

RESUMO

Hydralazine has been shown to reduce mortality in patients with congestive heart failure when given concomitantly with isosorbide dinitrate. Recently, we demonstrated that nitrate tolerance is in part due to enhanced vascular superoxide .O2- production. We sought to determine mechanisms whereby hydralazine may prevent tolerance. Rabbits either received no treatment, nitroglycerin patches (1.5 micrograms/kg/min x 3 d), hydralazine alone (10 mg/kg/d in drinking water), or hydralazine and nitroglycerin. Aortic segments were studied in organ chambers and relative rates of vascular .O2- production were determined using lucigenin-enhanced chemiluminescence. Nitroglycerin treatment markedly inhibited relaxations to nitroglycerin (maximum relaxations in untreated: 92 +/- 1 vs. 64 +/- 3% in nitroglycerin-treated patients and increased vascular .O2- production by over two-fold (P < 0.05). Treatment with hydralazine in rabbits not receiving nitroglycerin significantly decreased .O2- production in intact rabbit aorta and increased sensitivity to nitroglycerin. When given concomitantly with nitroglycerin, hydralazine completely prevented the development of nitrate tolerance and normalized endogenous rates of vascular .O2- production. Studies of vessel homogenates demonstrated that the major source of .O2- was an NADH-dependent membrane-associated oxidase displaying activities of 67 +/- 12 vs. 28 +/- 2 nmol .O2-.min-1.mg protein-1 in nitroglycerin-treated vs. untreated aortic homogenates. In additional studies, we found that acute addition of hydralazine (10 microM) to nitroglycerin-tolerant vessels immediately inhibited .O2- production and NADH oxidase activity in vascular homogenates. The chemiluminescence signal was inhibited by a recombinant heparin-binding superoxide dismutase (HBSOD) demonstrating the specificity of this assay for .O2-. These observations suggest that a specific membrane-associated oxidase is activated by chronic nitroglycerin treatment, and the activity of this oxidase is inhibited by hydralazine, providing a mechanism whereby hydralazine may prevent tolerance. The ability of hydralazine to inhibit vascular .O2- anion production represents a novel mechanism of action for this drug.


Assuntos
Insuficiência Cardíaca/tratamento farmacológico , Hidralazina/uso terapêutico , NADH NADPH Oxirredutases/metabolismo , Nitroglicerina/uso terapêutico , Vasodilatadores/uso terapêutico , Animais , Aorta/enzimologia , Aorta/metabolismo , Quimioterapia Combinada , Regulação Enzimológica da Expressão Gênica , Técnicas In Vitro , Óxido Nítrico/metabolismo , Coelhos , Recombinação Genética , Superóxido Dismutase/genética , Superóxidos/metabolismo
17.
Mol Cell Biol ; 8(1): 105-13, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3336354

RESUMO

A rapid affinity labeling procedure with enhanced specificity was developed to identify DNA-binding proteins. 32P was first introduced at unique phosphodiester bonds within the DNA recognition sequence. UV light-dependent cross-linking of pyrimidines to amino acid residues in direct contact at the binding site, followed by micrococcal nuclease digestion, resulted in the transfer of 32P to only those specific protein(s) which recognized the binding sequence. This method was applied to the detection and characterization of proteins that bound to the upstream promoter sequence (-50 to -66) of the human adenovirus type 2 major late promoter. We detected two distinct proteins with molecular weights of 45,000 and 116,000 that interacted with this promoter element. The two proteins differed significantly in their chromatographic and cross-linking behaviors.


Assuntos
Adenovírus Humanos/genética , Proteínas de Ligação a DNA/análise , Regiões Promotoras Genéticas , Fatores de Transcrição/análise , Marcadores de Afinidade , Sítios de Ligação , Cromatografia , Regulação da Expressão Gênica , Peso Molecular , Transcrição Gênica , Raios Ultravioleta
18.
J Natl Cancer Inst ; 87(19): 1446-55, 1995 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-7674332

RESUMO

In the past decade, significant progress has been made in understanding the genetic component of familial cancers. Genes associated with familial colon and breast cancers have recently been isolated and molecular diagnostic tests are expected to become available in the near future. Clinicians now have the opportunity to recognize and counsel individuals with elevated risk of cancer by identifying risk factors and genes associated with cancer predisposition. The rapid advances in molecular technology are a direct challenge to the medical community and cancer centers to supply specialized clinical services for familial cancers. We sought to ascertain the activities of cancer centers in the development of programs and the provision of genetic services for familial cancer. We surveyed 41 centers with National Cancer Institute (NCI) cancer center support grants. One half of the centers responding (17 of 34) reported that they provide some genetic services for familial cancer. About one half of these 17 centers (eight [57%] of 14; the three remaining clinics that responded had incomplete information on this indicator) see a variety of patient types on a small scale (fewer than 100 patients per year), and most provide four basic clinical evaluations: medical evaluation, cancer risk assessment, genetic counseling, and pedigree analysis. Staffing of each center varied widely, as did the types of screening services offered (including molecular diagnostic testing). Several centers (six [35%] of 17) indicated that they were in the developmental stages for serving familial cancer patients, and many seem to be increasing their activities in this area. The remaining 17 NCI-supported centers that responded, however, currently provide no genetic services for familial cancers. The results of this survey suggest that there is interest in developing clinical programs for familial cancers by NCI-supported cancer centers, but most of these programs are in developmental stages. A base line has been established to monitor future progress for the provision of cancer genetic services.


Assuntos
Institutos de Câncer/estatística & dados numéricos , Aconselhamento Genético/estatística & dados numéricos , Neoplasias/genética , Testes Genéticos , Humanos , Programas de Rastreamento , National Institutes of Health (U.S.) , Neoplasias/prevenção & controle , Inquéritos e Questionários , Estados Unidos
19.
Cancer Res ; 37(2): 561-7, 1977 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-188550

RESUMO

The phospholipids of both mitochondrial and microsomal membranes from normal liver, host liver, and Morris hepatoma 7777 were isolated, separated, and quantitated. The total as well as the individual fatty acid concentrations and compositions were determined. The total phosphlipids isolated from tumor mitochondria were idly altered, compared with mitochondria from other normal or host liver. The polyenoic acids were decreased, and there was a concomitant increase in the monoenes. When the respiratory control was determined, the tumor mitochondria exhibited a significant decrease in this parameter. The tumor microsomal membrane fraction, on the other hand, contained about 50% less phospholipid than the controls. The fatty acid patterns of the total as well as the individual phospholipids were quite similar to those observed in the mitochondria. The species of phosphatidylcholine from both membrane fractions were separated by argentation chromatography of the intact molecules, and, as predicted by the fatty acid compositions, the major species of the tumor was the monoenoic/dienoic fraction. The acyl coenzyme A:1-acyl glycerophosphorylcholine acyltransferases, which aid in controlling the fatty acid composition of phospholipids, were measured. The very marked increase in activity of these enzymes toward polyenoic as well as monoenic fatty acids suggested that the polyenoic acids were not available for use in the resynthesis of the phosphatidylcholines in the tumor.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Fosfolipídeos/metabolismo , 1-Acilglicerofosfocolina O-Aciltransferase/análise , Aciltransferases/metabolismo , Animais , Ácidos Graxos/análise , Ácidos Graxos Insaturados/análise , Ácidos Graxos Insaturados/metabolismo , Feminino , Membranas/análise , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Neoplasias Experimentais/metabolismo , Fosfatidiletanolaminas/análise , Fosfatidilinositóis/análise , Fosfatidilserinas/análise , Ratos , Esfingomielinas/análise
20.
Cancer Res ; 54(13): 3436-41, 1994 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-8012963

RESUMO

The dose of interleukin 2 (IL-2) which can be administered to cancer patients is limited largely by a capillary leak syndrome. Pentoxifylline (PTX) is a methylxanthine which reduces IL-2 toxicity in animals. Ciprofloxacin (Cipro) modifies the metabolism of methylxanthines and, when coadministered with PTX, increases levels of PTX and certain of its metabolites. We conducted a phase Ib trial in patients receiving IL-2 and lymphokine-activated killer cell (LAK) cell therapy for metastatic renal cell carcinoma to identify the maximum tolerated dose of PTX which could be coadministered with Cipro in this setting. Eighteen patients received IL-2 (Roche) by continuous infusion at 6 x 10(6) units/m2/day on days 1-5 and underwent leukapheresis on days 7-9. LAK cells were infused on days 12-14. IL-2 was administered at 2 x 10(6) units/m2/day on days 10-20. Cohorts of patients received PTX at 2.5 (n = 3), 3.1 (n = 6), 3.9 (n = 6), and 4.9 (n = 3) mg/kg by 30 min i.v. infusion every 4 h on days 0-5 and 10-20 and Cipro (500 mg p.o. every 12 h) on days 1-5 and 10-20. Toxicity was compared with that observed in 33 historical control patients who received 37 cycles of an identical regimen of IL-2/LAK without PTX/Cipro. PTX at 2.5-3.9 mg/kg and Cipro were well tolerated. The maximum tolerated dose of PTX was 3.9 mg/kg. Dose-limiting emesis (n = 1) and atrial fibrillation (n = 2) occurred at 4.9 mg/kg and were reversible. Two complete, one partial and one minor, responses were observed. Patients treated with 3.9 mg/kg PTX received 95.0% of the planned dose of IL-2 as compared to 72.8% in the control patients (P < 0.025), primarily due to a lower incidence of azotemia and metabolic acidosis in PTX/Cipro recipients than had been seen in the historical control patients. The results of this study demonstrate that PTX/Cipro can be administered to patients receiving IL-2/LAK without apparent loss of therapeutic efficacy. Moreover, PTX/Cipro recipients exhibited less toxicity than historical controls. Therefore, treatment with PTX/Cipro may allow delivery of higher doses of IL-2, which might induce more responses in IL-2-responsive tumors and regression of tumors unresponsive to conventional doses of IL-2.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma de Células Renais/terapia , Imunoterapia Adotiva , Interleucina-2/uso terapêutico , Neoplasias Renais/terapia , Células Matadoras Ativadas por Linfocina/transplante , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/sangue , Carcinoma de Células Renais/sangue , Ciprofloxacina/efeitos adversos , Ciprofloxacina/sangue , Ciprofloxacina/uso terapêutico , Feminino , Humanos , Interleucina-2/efeitos adversos , Neoplasias Renais/sangue , Masculino , Pessoa de Meia-Idade , Pentoxifilina/efeitos adversos , Pentoxifilina/sangue , Pentoxifilina/uso terapêutico
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