Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Oncol (R Coll Radiol) ; 35(5): 283-291, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36804292

RESUMO

AIMS: In 2008, the UK National Health Service started the Proton Overseas Programme (POP), to provide access for proton beam therapy (PBT) abroad for selected tumour diagnoses while two national centres were being planned. The clinical outcomes for the patient group treated for central nervous system (CNS), base of skull, spinal and paraspinal malignancies are reported here. MATERIALS AND METHODS: Since the start of the POP, an agreement between the National Health Service and UK referring centres ensured outcomes data collection, including overall survival, local tumour control and late toxicity data. Clinical and treatment-related data were extracted from this national patient database. Grade ≥3 late toxicities were reported following Common Terminology Criteria for Adverse Events (CTCAE) v 4.0 definition, occurring later than 90 days since the completion of treatment. RESULTS: Between 2008 and September 2020, 830 patients were treated within the POP for the above listed malignancies. Overall survival data were available for 815 patients and local control data for 726 patients. Toxicity analysis was carried out on 702 patients, with patients excluded due to short follow-up (<90 days) and/or inadequate toxicity data available. After a median follow-up of 3.34 years (0.06-11.58), the overall survival was 91.2%. The local control rate was 85.9% after a median follow-up of 2.81 years (range 0.04-11.58). The overall grade ≥3 late toxicity incidence was 11.97%, after a median follow-up of 1.72 years (0.04-8.45). The median radiotherapy prescription dose was 54 GyRBE (34.8-79.2). CONCLUSIONS: The results of this study indicate the safety of PBT for CNS tumours. Preliminary clinical outcomes following PBT for paediatric/teen and young adult and adult CNS tumours treated within the POP are encouraging, which reflects accurate patient selection and treatment quality. The rate of late effects compares favourably with published cohorts. Clinical outcomes from this patient cohort will be compared with those of UK-treated patients since the start of the national PBT service in 2018.


Assuntos
Neoplasias do Sistema Nervoso Central , Terapia com Prótons , Adolescente , Adulto Jovem , Humanos , Criança , Prótons , Medicina Estatal , Terapia com Prótons/efeitos adversos , Terapia com Prótons/métodos , Neoplasias do Sistema Nervoso Central/radioterapia , Sistema Nervoso Central , Reino Unido/epidemiologia
2.
Int J Obes (Lond) ; 34(5): 859-70, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20125104

RESUMO

OBJECTIVE: In the metabolic syndrome (MetS), increased fat storage in 'nonadipose' tissues such as skeletal muscle may be related to insulin resistance ('lipid overflow' hypothesis). The objective of this study was to examine the effects of dietary fat modification on the capacity of skeletal muscle to handle dietary and endogenous fatty acids (FAs). SUBJECTS AND METHODS: In total, 29 men with the MetS were randomly assigned to one of four diets for 12 weeks: a high-fat saturated fat diet (HSFA, n=6), a high-fat monounsaturated fat diet (HMUFA, n=7) and two low-fat high-complex carbohydrate diets supplemented with (LFHCCn-3, n=8) or without (LFHCC, n=8) 1.24 g per day docosahexaenoic and eicosapentaenoic acid. Fasting and postprandial skeletal muscle FA handling was examined by measuring arteriovenous concentration differences across the forearm muscle. [(2)H(2)]-palmitate was infused intravenously to label endogenous triacylglycerol (TAG) and free fatty acids in the circulation and subjects received a high-fat mixed meal (2.6 MJ, 61 energy% fat) containing [U-(13)C]-palmitate to label chylomicron-TAG. RESULTS: Postprandial circulating TAG concentrations were significantly lower after dietary intervention in the LFHCCn-3 group compared to the HSFA group (DeltaiAUC -139+/-67 vs 167+/-70 micromol l(-1) min(-1), P=0.009), together with decreased concentrations of [U-(13)C]-labeled TAG, representing dietary FA. Fasting TAG clearance across forearm muscle was decreased on the HSFA diet, whereas no differences were observed in postprandial forearm muscle FA handling between diets. CONCLUSION: Chronic manipulation of dietary fat quantity and quality did not affect forearm muscle FA handling in men with the MetS. Postprandial TAG concentrations decreased on the LFHCCn-3 diet, which could be (partly) explained by lower concentration of dietary FA in the circulation.


Assuntos
Gorduras na Dieta/metabolismo , Ácidos Graxos/sangue , Comportamento Alimentar/fisiologia , Resistência à Insulina/fisiologia , Síndrome Metabólica/metabolismo , Músculo Esquelético/metabolismo , Adulto , Idoso , Gorduras na Dieta/administração & dosagem , Jejum , Humanos , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Período Pós-Prandial
3.
Am J Transplant ; 7(5): 1158-66, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17331108

RESUMO

Non-heart-beating donor (NHBD) kidneys may substantially expand the donor pool, but many transplant centers are reluctant to use these kidneys because of the relatively high incidence of primary nonfunction (PNF). In heart-beating donor kidneys, intravascular fluid depletion during transplant surgery is associated with delayed graft function (DGF). Therefore, we studied the effect of the recipients' hemodynamic status on the outcome of 177 NHBD kidney transplantations. Independent statistically significant predictors of PNF were average central venous pressure (CVP) below 6 cmH(2)O (adjusted odds ratio (AOR) 3.1 (95% CI: 1.4-7.1), p=0.007), average systolic blood pressure below 110 mmHg (AOR 2.6 (95% CI: 1.1-5.9), p=0.03) and pre-operative diastolic blood pressure below 80 mmHg (AOR 2.4 (95% CI: 1.0-5.9), p=0.05). Donor characteristics were not independently associated with PNF (p>0.10). In a subgroup analysis of 56 paired kidneys, 29% of the recipients with the lower CVP of the pair experienced PNF compared with 11% of their counterparts with higher CVP (p=0.09). Our study indicates that recipient hemodynamics during transplant surgery are major predictors of PNF. Therefore, improving recipient hemodynamics by expansion of the intravascular volume is expected to enhance the results of NHBD kidney transplantations and may enlarge the donor pool by increasing the acceptance of NHBD kidneys.


Assuntos
Pressão Sanguínea/fisiologia , Rejeição de Enxerto/fisiopatologia , Coração/fisiologia , Transplante de Rim/fisiologia , Adulto , Feminino , Parada Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Valor Preditivo dos Testes , Prognóstico , Traumatismo por Reperfusão/fisiopatologia , Estudos Retrospectivos , Fatores de Risco , Doadores de Tecidos , Resultado do Tratamento
4.
Hypertens Pregnancy ; 21(1): 39-49, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12044342

RESUMO

OBJECTIVE: An increase in reactive oxygen species (ROS) and lipid peroxides and a comprised antioxidant status has been implicated in the pathophysiology of severe preeclampsia. This study investigates whether oxidative stress and impaired antioxidant systems also contribute to milder forms of hypertensive disorders in pregnancy. Furthermore, ethene in exhaled air, a noninvasive measure for oxidative stress, was evaluated and compared with two other more established biomarkers. METHODS: Ethene in exhaled air, plasma protein carbonyls, and the ratio of free glutathione/oxidized glutathione (GSHfree/GSHox) as markers for oxidative stress as well as the antioxidants vitamins C and E, uric acid, glutathione, and the oxygen radical absorbance capacity (ORAC) in plasma were measured in 30 healthy nonpregnant, 14 normal pregnant, 9 women with pregnancy-induced hypertension (PIH), and 14 preeclamptic women. Pregnant participants were measured during pregnancy and after delivery. RESULTS: Women suffering from PIH and preeclampsia showed higher levels of the antioxidants vitamin E and uric acid, and lower levels of vitamin C compared with normal pregnant and nonpregnant women. All markers for oxidative stress were comparable between groups. Ethene levels showed a positive correlation with protein carbonyls but no correlation could be demonstrated with the free glutathione/oxidised glutathione ratio. CONCLUSIONS: PIH and preeclampsia are associated with minor alterations in antioxidant levels without signs of oxidative stress. Detection of ethene in exhaled air seems a promising noninvasive method to study lipid peroxidation but further research in more severe preeclampsia is needed.


Assuntos
Etilenos/metabolismo , Hipertensão/metabolismo , Estresse Oxidativo , Complicações Cardiovasculares na Gravidez/metabolismo , Antioxidantes/metabolismo , Biomarcadores/análise , Testes Respiratórios , Feminino , Humanos , Peroxidação de Lipídeos , Pré-Eclâmpsia/metabolismo , Gravidez
5.
Am J Vet Res ; 62(1): 87-96, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11197567

RESUMO

OBJECTIVE: To determine effect of leukocyte depletion on hematologic, morphologic, and metabolic variables of equine jejunum after induction of arterial low-flow ischemia and reperfusion by use of an extracorporeal circuit. ANIMALS: 14 healthy adult horses. PROCEDURE: A segment of jejunum was surgically removed and maintained in an isolated circuit for 3 hours (control group), arterial flow was reduced to 20% of baseline for 40 minutes followed by 1 hour of reperfusion (low-flow group), or leukocyte depletion was filter-induced, and low-flow ischemia and reperfusion were conducted as in the low-flow control group (filter-treated group). Various metabolic, hemodynamic, and histomorphologic variables were evaluated, including effects of electrical field stimulation and L-N-nitro-arginine-methyl-ester (L-NAME) on contractile activity. RESULTS: The extracorporeal circuit appeared to maintain the jejunum within physiologic limits for an extended period. Low-flow ischemia with reperfusion induced significant differences in various measurements, compared with control specimens. Significant differences were not detected between the low-flow and filter-treated groups. Myeloperoxidase activity was greater in the low-flow group than the control group, whereas a difference was not detected between control and filter-treated groups. CONCLUSIONS AND CLINICAL RELEVANCE: The extracorporeal circuit maintained intestine for 3 hours in a physiologic state and may be used for simulation of tissue injury. Leukocyte depletion generally did not attenuate the effects of low-flow ischemia and reperfusion on equine small intestine.


Assuntos
Circulação Extracorpórea , Mucosa Intestinal/fisiologia , Isquemia/fisiopatologia , Jejuno/fisiologia , Leucócitos/fisiologia , Músculo Liso/fisiologia , Animais , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Colo/citologia , Estimulação Elétrica , Circulação Extracorpórea/instrumentação , Circulação Extracorpórea/métodos , Cavalos , Técnicas In Vitro , Mucosa Intestinal/irrigação sanguínea , Jejuno/irrigação sanguínea , Jejuno/efeitos dos fármacos , Leucócitos/citologia , Modelos Biológicos , Contração Muscular/efeitos dos fármacos , Músculo Liso/irrigação sanguínea , Músculo Liso/efeitos dos fármacos , NG-Nitroarginina Metil Éster/farmacologia , Peroxidase/metabolismo , Fluxo Sanguíneo Regional , Reperfusão
7.
Appl Opt ; 37(4): 753-8, 1998 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-18268649

RESUMO

An algorithm is presented for calculating the phase difference that is obtained with rapid-switching, double-pulsed holographic interferometry. Imperfect switching between reference beams in between two laser pulses causes a distortion in the phase-stepped interferograms that results in erroneous phase calculation when conventional phase-calculating algorithms are used. Instead of estimating the error that is involved, an extra step is added to a more conventional algorithm such as Carré's algorithm, so that this leakage effect is compensated for. Thus the desired phase difference is found. Also, a measure is found for excluding unreliable calculations, based on the light intensities and phase steps for each pixel and the leakage ratios.

8.
J Cardiothorac Vasc Anesth ; 9(4): 362-7, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7579103

RESUMO

OBJECTIVE: To study the anesthetic efficacy of two different background infusion rates for alfentanil in a total intravenous anesthesia (TIVA) technique using propofol. Therefore, the effects of these infusions on hemodynamic stability and on the suppression of hemodynamic and somatic responses to noxious stimuli were compared. DESIGN: Prospective and randomized. SETTING: The study was performed in a university hospital setting. Two patient groups were compared. INTERVENTIONS: Anesthesia was induced in group 1 (n = 16) with alfentanil 50 micrograms/kg and in group 2 (n = 14) with alfentanil 75 micrograms/kg, infused in 4 min, as well as with an infusion of propofol at a rate of 10 mg/kg/h in both groups. After 4 min, the alfentanil infusion was reduced to 1 microgram/kg/min in group 1 and to 2 micrograms/kg/min in group 2. The propofol infusion was reduced following sternal spread to 3 mg/kg/h. Responses indicating inadequate anesthesia were treated with additional alfentanil bolus doses. MEASUREMENTS AND MAIN RESULTS: Induction of anesthesia in group 1 was associated with significant decreases in systolic and diastolic (-13%) blood pressures, cardiac index (-16%) and left ventricular stroke work index (-31%). Hemodynamic changes were similar in group 2, except for the greater fall in systemic vascular resistance during maintenance of anesthesia. There was no difference in the incidence of breakthrough hypertension between the two groups (in 44% and 43% of the patients, respectively) and in the number of alfentanil bolus supplements. There were also no differences in the incidence of ischemia, myocardial infarction or duration of postoperative ventilation. CONCLUSIONS: Because both infusions provided equally stable anesthesia, the lower infusion regimen for alfentanil is the more appropriate technique. Using this technique, the administration of additional alfentanil boluses just before stressful surgical episodes will further improve hemodynamic stability.


Assuntos
Alfentanil/administração & dosagem , Anestesia Intravenosa , Anestésicos Intravenosos/administração & dosagem , Ponte de Artéria Coronária , Propofol/administração & dosagem , Alfentanil/sangue , Alfentanil/farmacologia , Anestésicos Intravenosos/sangue , Anestésicos Intravenosos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Débito Cardíaco/efeitos dos fármacos , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Hipertensão/etiologia , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologia , Isquemia Miocárdica/etiologia , Propofol/farmacologia , Estudos Prospectivos , Respiração Artificial , Volume Sistólico/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos
9.
J Gen Virol ; 74 ( Pt 2): 315-8, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8429307

RESUMO

Andean potato mottle virus (APMV), an endemic South American comovirus, has a bipartite genome consisting of two plus-strand RNA molecules (M and B RNA). We have cloned the 3' half of the B RNA and identified the complete sequence of the putative APMV RNA polymerase. The RNA polymerase gene is part of a large polyprotein-encoding open reading frame. The putative, mature RNA polymerase, as deduced by comparison with the related cowpea mosaic virus (CPMV), type member of the comovirus group, is 703 amino acids long and shows a large degree of similarity with CPMV and other RNA polymerases.


Assuntos
RNA Polimerases Dirigidas por DNA/genética , Genes Virais/genética , Vírus de Plantas/genética , RNA Viral/genética , Solanum tuberosum/microbiologia , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Dados de Sequência Molecular , Vírus de Plantas/enzimologia , Homologia de Sequência
11.
Plant Cell Rep ; 10(6-7): 354-7, 1991 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24221673

RESUMO

Introduction of foreign genes into plant tissues via Agrobacterium tumefaciens based vectors requires specific knowledge of Agrobacterium-host compatibility. Therefore, to develop a transformation protocol for peanut (Arachis hypogaea L.), five Brazilian cultivars were screened with four wild-type A.tumefaciens strains. Successful transformation was dependent on specific bacterial strain-plant cultivar interactions and strain A281 was the most effective for tumor induction. Tumors displayed hormone autonomous growth, were opine positive and contained DNA that was homologous to the T-DNA of the inciting strain. Tumors induced on seed and seedling explants by A281 (pTD02) also expressed the reporter genes gus and npt-II contained in the binary vector. These results show that peanut is a permissive host for the acceptance of genes from specific A.tumefaciens gene vectors.

12.
J Mol Biol ; 203(2): 373-84, 1988 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-3199438

RESUMO

Induction of Ti plasmid virulence (vir) gene expression during the early stages of plant cell transformation by Agrobacterium tumefaciens initiates the generation of several T-DNA-associated molecular events: (1) site-specific nicks at T-DNA border sequences (border nicks); (2) free, unipolar, linear, single-stranded T-DNA copies (T-strands); and (3) double-stranded, circular T-DNA molecules (T-circles). The first two T-DNA products have been detected in A. tumefaciens, while T-circles have only been detected following Escherichia coli transformation or transduction. The relationship between the three events has not been evaluated since the genesis of T-circles in A. tumefaciens has not been clarified. Evidence is presented here that T-circles are not an artefact of E. coli transformation, but are present as free, double-stranded molecules in A. tumefaciens resulting from site-specific reciprocal recombination between the left and right 25-base-pair border sequences that flank the T-DNA. Furthermore, the frequency of T-circle formation correlates with the frequency of formation of its reciprocal product, the Ti plasmid deleted in the T-DNA region. Several types of recombinant T-DNA circles arise after activation of vir gene expression, a major class representing precise site-specific recombination between both T-DNA borders, and a minor class representing recombination events either utilizing only one T-DNA border sequence and other Ti plasmid sequences, or utilizing only Ti plasmid sequences (i.e. no T-DNA borders). Nucleotide sequence analyses show that when one (nicked) border recombines with other Ti plasmid sequences, a small stretch (16 to 17 base-pairs) of local homology suffices to allow crossing over.


Assuntos
DNA Bacteriano/genética , Recombinação Genética , Rhizobium/genética , Sequência de Bases , DNA Circular/genética , Regulação da Expressão Gênica , Modelos Genéticos , Dados de Sequência Molecular , Plasmídeos , Virulência
13.
EMBO J ; 6(4): 857-63, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3595560

RESUMO

Agrobacterium tumefaciens transfers its Ti-plasmid T-DNA to plant cells. This process is initiated by plant-induced activation of the Ti-plasmid virulence loci, resulting in the generation of single stranded (ss) cleavages of the Ti-plasmid T-DNA border sequences (border nicks) and ss linear unipolar T-DNA molecules (T-strands). A single T-strand is produced from the two-border T-region of the pGV3850 nopaline plasmid. In this paper the induced molecular events for the complex T-region of the pTiA6 octopine plasmid are analyzed. This T-region carries four T-DNA borders delimiting three T-DNA elements (TR, TC and TL). Induction of pTiA6 generates cleavages independently at its border repeats, and six distinct T-strand species corresponding to TR, TR/TC, TR/TC/TL, TC, TC/TL and TL. These T-strand molecules are linear and correspond to the bottom strand of the pTiA6 T-region. Thus, borders can function for both initiation and termination of T-strand synthesis. We propose that the different pTiA6 T-strands are independently generated, and that the distribution of border nicks within the parental T-region determines which T-strand is produced. To identify genes involved in T-strand production, pTiA6 virulence (vir) and chromosomal virulence (chv) mutant strains were analyzed. VirA and VirG, the vir regulatory loci are required. Furthermore, the two 5' cistrons of virD are required for both border nicks and T-strands, suggesting that these genes encode the border endonuclease, and that T-strand production is dependent on border nicks. That no mutants are defective for T-strands alone suggests that functions encoded outside of vir and chv might mediate some of the later reactions of T-strand synthesis.


Assuntos
Proteínas de Bactérias/genética , Regulação da Expressão Gênica , Genes Bacterianos , Genes , Plasmídeos , Rhizobium/genética , Mutação , Rhizobium/patogenicidade , Virulência
14.
Science ; 235(4788): 587-91, 1987 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-17758248

RESUMO

The T-DNA transfer process of Agrobacterium tumefaciens is activated by the induction of the expression of the Ti plasmid virulence (vir) loci by plant signal molecules such as acetosyringone. The vir gene products act in trans to mobilize the T-DNA element from the bacterial Ti plasmid. The T-DNA is bounded by 25-base pair direct repeat sequences, which are the only sequences on the element essential for transfer. Thus, specific reactions must occur at the border sites to generate a transferable T-DNA copy. The T-DNA border sequences were shown in this study to be specifically nicked after vir gene activation. Border nicks were detected on the bottom strand just after the third or fourth base (+/- one or two nucleotides) of the 25-base pair transferpromoting sequence. Naturally occurring and base-substituted derivatives of the 25-base pair sequences are effective substrates for acetosyringone-induced border cleavage, whereas derivatives carrying only the first 15 or last 19 base pairs of the 25-base pair sequence are not. Site-specific border cleavages occur within 12 hours after acetosyringone induction and probably represent an early step in the T-DNA transfer process.

15.
An Esp Pediatr ; 25(5): 341-4, 1986 Nov.
Artigo em Espanhol | MEDLINE | ID: mdl-3544991

RESUMO

Simple renal cysts are infrequently diagnosed in children. Technique improvements in pediatric uroradiology lead to more frequent recognition. Authors review urographic and ultrasound studies of five simple renal cysts in children, between two days and seven years, seen during the last five years.


Assuntos
Doenças Renais Císticas/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Doenças Renais Císticas/diagnóstico por imagem , Masculino , Radiografia , Ultrassonografia
17.
EMBO J ; 2(12): 2151-60, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-16453483

RESUMO

In an attempt to elucidate the transfer and integration mechanism of Agrobacterium DNA upon crown gall induction, we translocated a borderless T-DNA to different sites of the C58 Ti plasmid. As a result of the physical linkage of the T-DNA onc genes with other Ti plasmid functions, the concerned strain retained tumor-inducing capacity. However, when the borderless T-DNA is separated on an independent replicon while all other pTi functions are provided in trans, the strain can no longer induce tumors on plants. We provide evidence that the right T-DNA border region harbors one or more in cis active functions essential in the transfer and/or stabilization of the T-DNA into plant cells. The strains used in these experiments allowed us to conclude that some function(s) of the Ti plasmid can induce plant cell proliferations independently of the T-DNA transformation event. The results described here indicate that other Ti plasmid sequences than solely the T-region can be transferred to plant cells.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...