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1.
Philos Trans A Math Phys Eng Sci ; 379(2195): 20190547, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33641460

RESUMO

Climate projections at very high resolution (kilometre-scale grid spacing) are becoming affordable. These 'convection-permitting' models (CPMs), commonly used for weather forecasting, better represent land-surface characteristics and small-scale processes in the atmosphere such as convection. They provide a step change in our understanding of future changes at local scales and for extreme weather events. For short-duration precipitation extremes, this includes capturing local storm feedbacks, which may modify future increases. Despite the major advance CPMs offer, there are still key challenges and outstanding science issues. Heavy rainfall tends to be too intense; there are challenges in representing land-surface processes; sub-kilometre scale processes still need to be parametrized, with existing parametrization schemes often requiring development for use in CPMs; CPMs rely on the quality of lateral boundary forcing and typically do not include ocean-coupling; large CPM ensembles that comprehensively sample future uncertainties are costly. Significant progress is expected over the next few years: scale-aware schemes may improve the representation of unresolved convective updrafts; work is underway to improve the modelling of complex land-surface fluxes; CPM ensemble experiments are underway and methods to synthesize this information with larger coarser-resolution model ensembles will lead to local-scale predictions with more comprehensive uncertainty context for user application. Large-domain (continental or tropics-wide) CPM climate simulations, potentially with additional earth-system processes such as ocean and wave coupling and terrestrial hydrology, are an exciting prospect, allowing not just improved representation of local processes but also of remote teleconnections. This article is part of a discussion meeting issue 'Intensification of short-duration rainfall extremes and implications for flash flood risks'.

2.
Australas Plant Pathol ; 50(6): 695-704, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34608354

RESUMO

Southern sting nematode (Ibipora lolii), by far the most damaging nematode pest of turfgrass in Australia, was first reported from the Newcastle area of New South Wales in 1979 and is now widely distributed in the Central Coast region of NSW; is causing severe damage to sportsgrounds in Perth, Western Australia; and has been reported from a few locations in other states. This paper reports a recent example of interstate transfer, as small rolls of turf transferred from a turf nursery in Victoria to the Brisbane Cricket Ground (the Gabba) for the Australian Football League Grand Final in October 2020 were found to be infested with I. lolii. Despite this transfer, evidence is provided to suggest that Queensland should be considered provisionally free of I. lolii. First, in the period from 2006 to 2021, 744 turfgrass samples from 160 Queensland locations were processed by two diagnostic laboratories and I. lolii was never detected. Second, I. lolii was not found at the two Queensland locations reported in 2010 as being infested. Third, an action plan designed to eliminate I. lolii from the Gabba (removal and disposal of the infested turf; fumigation of the sites where the infested turf had been laid; and application of nematicides to the fumigated areas and the whole oval) appears to have been successful, as I. lolii was not detected in a post-treatment monitoring program. The paper concludes by arguing that Queensland biosecurity authorities should list I. lolii as one of its priority pests, establish a surveillance program for the nematode, and develop strategies to minimise the risk of I. lolii being transferred into and within the state.

3.
J Nematol ; 49(3): 327-333, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29062157

RESUMO

Protogamasellus mica was extracted from a sugarcane field in Australia and cultured on bacterial-feeding nematodes. Studies with various nematodes in laboratory arenas showed that one mite and its progeny reduced nematode numbers by between 26 and 50 nematodes/day. A bacterivore (Mesorhabditis sp.), a fungivore (Aphelenchus avenae), and two plant parasites (root-knot nematode, Meloidogyne javanica and root-lesion nematode, Pratylenchus zeae) were all reduced at much the same rate despite the fact that the nematodes are quite different in size and motility and belong to different trophic groups. When sugarcane was grown in the greenhouse for 8 wk, stunt nematode (Tylenchorhynchus annulatus), a plant parasite that feeds ectoparasitically on roots, was almost eliminated from pots inoculated with the mite, and numbers of microbivores and root-lesion nematode were markedly reduced. Huge reductions in nematode populations were also observed when mites were added to microcosms containing small quantities of defaunated soil. These results show that P. mica multiplies rapidly when nematodes are available as a food source and has the capacity to play a role in regulating populations of both plant-parasitic and free-living nematodes. Future research should focus on understanding the crop and soil management practices required to enable this mite and other predatory species to thrive.

4.
Folia Morphol (Warsz) ; 74(4): 540-3, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26620519

RESUMO

Aberrant arterial variations in the branching pattern of the coeliac trunk are of great interest to surgeons and radiologists. We report on a rare arterial variation found in a 79-year-old cadaver during educational dissection. Specifically, the coeliac axis formed a unique incomplete trunk termed the hepato-hepatic trunk. The splenic artery arose separately from the anterior aspect of the abdominal aorta. On the right side, there was a right hepatic artery giving rise to a gastroduodenal but an absence of the left hepatic. On the left side, there was a branch coursing towards the porta hepatis; the left hepatic artery, dividing into the left gastric, an accessory left gastric, and a branch to the distal oesophagus. The hepato-hepatic trunk formed a ring-shaped vascular structure around the caudate lobe of the liver. Precise mapping and observation of the extrahepatic arteries and bile duct branches is essential in a variety of hepato-biliary laparoscopic procedures of the liver and gallbladder. Other operative procedures requiring, a comprehensive kno-wledge of the varied coeliac trunk patterns are liver transplantation and arterial embolism for hepatic tumour therapy.

5.
Skeletal Radiol ; 43(2): 179-89, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24240323

RESUMO

OBJECTIVE: Sacrectomy and ilio-lumbar reconstruction is an uncommonly performed complex surgical procedure for the treatment of sacral neoplasia. There are many challenges in the post-operative period including the potential for tumor recurrence, infection, and construct failure. We present our experience of this patient cohort and describe the complications and imaging appearances that can be encountered during the follow-up period. MATERIALS AND METHODS: Retrospective review of our Orthopaedic Oncology database was undertaken which has been collected over a 30-year period to identify patients that had undergone sacrectomy and ilio-lumbar reconstruction. Pre and post-operative imaging including radiographs, CT, and MRI was reviewed. These were viewed by two experienced musculoskeletal radiologists with consensus opinion if there was disagreement over the imaging findings. Data regarding patient demographics, tumor type, and dimensions was collected. Serial review of radiographs, CT, and MRI was performed to assess implant position and integrity, strut graft position and union, and for the presence of recurrence within the surgical bed. RESULTS: Five male and two female patients (mean age 36 years, age range 15-54 years) were treated with this procedure. Histological diagnoses included chordoma, chondrosarcoma, osteosarcoma, and spindle cell sarcoma. Mean maximal tumor size on pre-operative imaging was 10.7 cm (range, 6-16 cm). Post-operative follow-up ranged from 10-46 months. A total of 76 imaging studies were reviewed. Commonly identified complications included vertical rod and cross-connector fracture and screw loosening. Fibula strut graft non-union and fracture was also evident on imaging review. Two patients demonstrated disease recurrence during the follow-up period. CONCLUSIONS: This study demonstrates the spectrum and frequency of complications that can occur following sacrectomy and ilio-lumbar reconstruction for sacral neoplasia.


Assuntos
Ílio/cirurgia , Vértebras Lombares/cirurgia , Imageamento por Ressonância Magnética , Sacro/cirurgia , Neoplasias da Coluna Vertebral/diagnóstico , Neoplasias da Coluna Vertebral/cirurgia , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Criança , Feminino , Humanos , Ílio/diagnóstico por imagem , Ílio/patologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Masculino , Pessoa de Meia-Idade , Procedimentos de Cirurgia Plástica , Estudos Retrospectivos , Sacro/diagnóstico por imagem , Sacro/patologia , Resultado do Tratamento , Vertebroplastia , Adulto Jovem
6.
Folia Morphol (Warsz) ; 73(4): 527-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25448916

RESUMO

Entrapment neuropathy of the supraclavicular nerve is rare and, when it occurs, is usually attributable to branching of the nerve into narrow bony clavicular canals. We describe another mechanism for entrapment of this nerve with the aberrant muscle; supraclavicularis being found during the routine dissection of an embalmed 82-year-old cadaver. Our report details a unique location for this rare muscular variation whereby the muscle fibres originated posteriorly on the medial aspect of the clavicle before forming a muscular arch over the supraclavicular nerve and passing laterally towards the trapezius and acromion. We recommend that in clinical instances of otherwise unexplained unilateral clavicular pain or tenderness, nerve compression from the supraclavicularis muscle must be borne in mind.

7.
Clin Imaging ; 90: 59-62, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35917663

RESUMO

OBJECTIVE: Sequential posteroanterior chest radiographs (CXRs) on any one patient are commonly displayed at different sizes on PACS monitors. The purpose of this study was to determine the cause of these differences, the percentage of radiographs affected, the relative change in magnification seen and if radiologists were aware of this display difference. METHODS: Differences in routine radiographer collimation pre-acquisition and image cropping (shuttering) post acquisition were noted. From three different hospitals, 300 posteroanterior (PA) erect CXRs with prior comparative studies were viewed side-by-side on a standard landscape display monitor. Variation in display size was calculated using the number of detector elements in the autofitted axis of the radiograph, when compared with the prior study. Correlation between patient gender and extent of magnification between images was recorded. Following this, a national survey was circulated to see if radiologists were aware of this phenomenon. RESULTS: Large variations in display size were noted. The mean extent of magnification between sequential PA chest radiographs was ±6.8% (range 0-21.6%). 98% of CXRs had some degree of variability in display size. There was no significant difference in the extent of variation in magnification based on age or gender. 86% of the radiologists who responded to the survey (n = 132) were unaware of any display size variability. CONCLUSION: Sequential DR acquired chest radiographs are routinely displayed with varying degrees of magnification on PACS monitors due to differences in radiographer practice and auto-fit display settings. Most radiologists surveyed were unaware of these differences and their causation.


Assuntos
Radiografia Torácica , Radiologistas , Humanos , Prevalência , Radiografia , Radiografia Torácica/métodos
8.
Phys Rev Lett ; 106(17): 175003, 2011 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-21635041

RESUMO

The Ω phase of the liquid sodium α-Ω dynamo experiment at New Mexico Institute of Mining and Technology in cooperation with Los Alamos National Laboratory has demonstrated a high toroidal field B(ϕ) that is ≃8×B(r), where B(r) is the radial component of an applied poloidal magnetic field. This enhanced toroidal field is produced by the rotational shear in stable Couette flow within liquid sodium at a magnetic Reynolds number Rm≃120. Small turbulence in stable Taylor-Couette flow is caused by Ekman flow at the end walls, which causes an estimated turbulence energy fraction of (δv/v)(2)∼10(-3).

9.
J Phys Chem A ; 115(45): 12733-7, 2011 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-21699211

RESUMO

Effective atomic orbitals (AOs) have been calculated by the method of the "fuzzy atoms" analysis by using the numerical molecular orbitals (MOs) obtained from plane-wave DFT calculation, i.e., without introducing any atom-centered functions. The results show that in the case of nonhypervalent atoms there are as many effective AOs with non-negligible occupation numbers, as many orbitals are in the classical minimal basis set of the given atom. This means that, for nonhypervalent systems, it is possible to present the MOs as sums of effective atomic orbitals that resemble very much the atomic minimal basis orbitals of the individual atoms (or their hybrids). For hypervalent atoms some additional orbitals basically of d-type are also of some importance; they are necessary to describe the back-donation to these positive atoms. It appears that the d-type orbitals play a similar role also for strongly positive carbon atoms. The method employed here is also useful to decide whether the use of polarization functions of a given type is a matter of conceptual importance or has only a numerical effect.

10.
J Nematol ; 43(3-4): 135-48, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23431051

RESUMO

Observations in three Australian sugarcane fields suggested that the soil just under the trash blanket (the covering of crop residue that remains on the soil surface after crops are harvested) was suppressive to plant-parasitic nematodes. Roots were concentrated in this upper layer of soil but plant-parasitic nematode populations were relatively low and roots showed few signs of nematode damage. Root biomass was much lower 15 cm further down the soil profile, where root health was poor and populations of plant-parasitic nematodes were 3-5 times higher than near the soil surface. A bioassay in which Radopholus similis (a nematode that does not occur in sugarcane soils) was inoculated into heat-sterilized and untreated soils, confirmed that biological factors were limiting nematode populations in some of the soils, with soil from 0-2 cm much more suppressive than soil from 15-17 cm. Surface soil from one site was highly suppressive, as only 16% of R. similis recoverable from heated soil were retrieved from this soil after 8 days. Numerous soil chemical, biochemical, and biological properties were measured, and non-linear regression analysis identified two major groups of factors that were significantly associated with suppressiveness. One group reflected the amount of organic matter in soil (total C, total N, and labile C) and the other was associated with the size of the free-living nematode community (total numbers of free-living nematodes, and numbers of plant associates, bacterial feeders, fungal feeders, and carnivores). These results suggested that suppressiveness was biologically mediated and was sustained by C inputs from crop residues and roots. Since nematode-trapping fungi in the test soils could not be quantified using traditional dilution plating methods, their possible role as suppressive agents was assessed by generating TRFLP profiles with Orbiliales-specific primers, and by sequencing cloned PCR products. Although the molecular data were obtained from a limited number of samples, the level of suppression was significantly correlated to the number of Orbiliales clone groups and was also related to the number of Orbiliales species and TRFs, suggesting that this group of fungi may have been one of the suppressive factors operating in the test soils.

11.
Eur Spine J ; 19(7): 1189-94, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20076978

RESUMO

To investigate the outcome of our management of patients with giant cell tumour of the sacrum and draw lessons from this. A retrospective review of medical records and scans for all patients treated at our unit over the past 20 years with a giant cell tumour of the sacrum. Of the 517 patients treated at our unit for giant cell tumour over the past 20 years, only 9 (1.7%) had a giant cell tumour in the sacrum. Six were female, three male with a mean age of 34 (range 15-52). All, but two tumours involved the entire sacrum and there was only one purely distal to S3. The mean size was 10 cm and the most common symptom was back or buttock pain. Five had abnormal neurology at diagnosis, but only one presented with cauda equina syndrome. The first four patients were treated by curettage alone, but two patients had intraoperative cardiac arrests and although both survived all subsequent curettages were preceded by embolisation of the feeding vessels. Of the seven patients who had curettage, three developed local recurrence, but all were controlled with a combination of further embolisation, surgery or radiotherapy. One patient elected for treatment with radiotherapy and another had excision of the tumour distal to S3. All the patients are alive and only two patients have worse neurology than at presentation, one being impotent and one with stress incontinence. Three patients required spinopelvic fusion for sacral collapse. All patients are mobile and active at a follow-up between 2 and 21 years. Giant cell tumour of the sacrum can be controlled with conservative surgery rather than subtotal sacrectomy. The excision of small distal tumours is the preferred option, but for larger and more extensive tumours conservative management may well avoid morbidity whilst still controlling the tumour. Embolisation and curettage are the preferred first option with radiotherapy as a possible adjunct. Spinopelvic fusion may be needed when the sacrum collapses.


Assuntos
Neoplasias Ósseas/cirurgia , Técnicas de Apoio para a Decisão , Tumor de Células Gigantes do Osso/cirurgia , Sacro/cirurgia , Adolescente , Adulto , Neoplasias Ósseas/patologia , Neoplasias Ósseas/radioterapia , Embolização Terapêutica , Feminino , Tumor de Células Gigantes do Osso/patologia , Tumor de Células Gigantes do Osso/radioterapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sacro/patologia , Resultado do Tratamento
12.
Euro Surveill ; 15(2)2010 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-20085694

RESUMO

An investigation is currently underway to explore and control an outbreak of Bacillus anthracis among drug users (mainly injecting) in Scotland. Contaminated heroin or a contaminated cutting agent mixed with the heroin is considered to be the most likely source and vehicle of infection. Heroin users have been advised of the risk. The risk to the general public is regarded as very low.


Assuntos
Antraz/etiologia , Bacillus anthracis/isolamento & purificação , Surtos de Doenças , Abuso de Substâncias por Via Intravenosa/microbiologia , Adulto , Feminino , Heroína/administração & dosagem , Heroína/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Escócia/epidemiologia
13.
Br J Sports Med ; 43(14): 1091-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19028734

RESUMO

There has recently been an increased emergence of research on the maltreatment of athletes in sport. It is suggested that research may play a particularly salient role with respect to athlete protection initiatives. However, as it stands, current research in this area is limited by a lack of consistency in definitions. The purpose of the paper, therefore, is to propose a conceptual framework of maltreatment in sport to be used among research practitioners. More specifically, a conceptual model of the different categories, constructs and constituents of maltreatment in sport is proposed. Sport-specific examples of the various maltreatments are outlined. Current literature is reviewed, and recommendations are made for future research.


Assuntos
Delitos Sexuais , Comportamento Social , Esportes/psicologia , Adolescente , Criança , Emoções , Emprego , Feminino , Previsões , Humanos , Masculino , Imperícia , Qualidade da Assistência à Saúde , Esportes/tendências , Medicina Esportiva/normas
14.
Obes Rev ; 8 Suppl 2: 17-27, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17371304

RESUMO

The Policy Options for Responding to the Growing Challenge of Obesity Research Project (PorGrow) study provided a unique opportunity to develop a large-scale application of a semi-quantitative technique for exploring interviewees' views on options to tackle obesity, using multi-criteria mapping. This 'heuristic' approach utilizes the advantages of a structured interviews framework by predefining a set of options for appraisal, while leaving interviewees free to select their own criteria for making their judgements. Additional information can be gleaned from the interview transcripts and related materials to set the appraisals in their policy context, and allowing interviewees to express their views on the options presented and their own appraisals. The PorGrow study team agreed a predefined set of 20 options for appraisal, and interviewed sets of stakeholders representing more than 20 aspects of policy development in each of the nine participating countries. The details of the methodology adopted are set out in this paper.


Assuntos
Planejamento em Saúde/organização & administração , Política de Saúde , Política Nutricional , Obesidade/epidemiologia , Obesidade/prevenção & controle , Formulação de Políticas , Europa (Continente) , Humanos , Entrevistas como Assunto , Investimentos em Saúde , Obesidade/etiologia , Medição de Risco
16.
Phys Rev Lett ; 85(13): 2773-6, 2000 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-10991230

RESUMO

Using a first-principles approach, we characterize dangling bond defects at Si-SiO2 interfaces by calculating hyperfine parameters for several relaxed structures. Interface models, in which defect Si atoms remain close to crystalline sites of the substrate upon relaxation, successfully describe P(b) and P(b0) defects at (111) and (100) interfaces, respectively. On the basis of calculated hyperfine parameters, we discard models of the P(b1) defect containing a first neighbor shell with an O atom or a strained bond. A novel model consisting of an asymmetrically oxidized dimer yields hyperfine parameters in excellent agreement with experiment and is proposed as the structure of the P(b1) center.

17.
Pharmacotherapy ; 19(10): 1177-80, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10512068

RESUMO

Toxic epidermal necrolysis (TEN) is a severe dermatologic disorder associated with mortality of up to 30%. Withdrawal of the causative agent is crucial in its management. Although thalidomide-induced dermatologic disorders rarely were reported before thalidomide was administered to patients positive for the human immunodeficiency virus, hypersensitivity reactions including rash are the agent's major dose-limiting toxicities in this population. As it is prescribed for other immunosuppressed patients, such as those with malignancies, the frequency of dermatologic reactions (including TEN) may increase. A 62-year-old woman developed TEN after approximately 5 weeks of thalidomide therapy for the treatment of a glioblastoma.


Assuntos
Inibidores da Angiogênese/efeitos adversos , Glioblastoma/tratamento farmacológico , Hipersensibilidade/etiologia , Síndrome de Stevens-Johnson/etiologia , Talidomida/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade
18.
J Bone Joint Surg Am ; 78(9): 1330-6, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8816647

RESUMO

We performed a point-prevalence survey of 15,799 children, six to fourteen years old, who formed part of a prospective longitudinal study. Our purpose was to detect the prevalence of scoliosis and to investigate associated factors. On the basis of the initial screening, 934 children (5.9 per cent) were referred for additional clinical and radiographic examinations; 896 children returned for this second evaluation. A lateral spinal curve with a Cobb angle of more than 5 degrees was seen in 431 children (2.7 per cent of the 15,799 children). Only seventy-six children (0.5 per cent) had a curve that met our definition of idiopathic scoliosis (a curve of more than 10 degrees with concordant apical rotation). The point-prevalence rate was higher in girls, and it increased with age. The rate was 0.1 per cent (four of 5246) in the age-group of six to eight years, 0.3 per cent (sixteen of 5831) in the age-group of nine to eleven years, and 1.2 per cent (fifty-six of 4722) in the age-group of twelve to fourteen years old. With allowance for the fact that different definitions of idiopathic scoliosis have been used in earlier studies, our results suggest that the natural history of idiopathic scoliosis may be becoming more benign spontaneously.


Assuntos
Escoliose/epidemiologia , Adolescente , Fatores Etários , Criança , Intervalos de Confiança , Estudos Transversais , Inglaterra/epidemiologia , Feminino , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Prevalência , Estudos Prospectivos , Radiografia , Remissão Espontânea , Rotação , Escoliose/diagnóstico por imagem , Escoliose/patologia , Fatores Sexuais , Coluna Vertebral/diagnóstico por imagem , Coluna Vertebral/patologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/patologia
19.
Br J Gen Pract ; 51(467): 456-60, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11407050

RESUMO

BACKGROUND: Recent research has shown the benefits of longer consultations in general practice. Approximately 40% of patients presenting to general practitioners (GPs) are psychologically distressed. Studies have shown that psychological morbidity increases with increasing socioeconomic deprivation. The combined effects of psychological morbidity and socioeconomic deprivation on consultation length are unknown. In addition, though it is known that doctors correctly identify half their distressed patients as such, the effect of consultation length on identification is unknown. AIM: To examine factors associated with presentation and recognition of psychological distress in GPs' surgeries and the interaction of these factors with consultation length. DESIGN OF STUDY: A cross-sectional study. SETTING: Nine general practices in the West of Scotland, involving 1075 consultations of 21 full-time GPs. METHOD: The main outcome measures were patient psychological distress (measured by General Health Questionnaire-12), doctors' identification of psychological distress, consultation length, and Carstairs deprivation category scores. RESULTS: The mean consultation length was 8.71 minutes (SD = 4.40) and the prevalence of positive GHQ scores was 44.7%. Increasing GHQ (greater psychological distress) and lower deprivation category scores (greater affluence) were associated with longer consultations. Positive GHQ scoring increased with greater socioeconomic deprivation and also peaked in the 30 to 39 years age group. Recognition of psychological distress was greater in longer consultations (50% increase in consultation length associated with 32% increase in recognition). CONCLUSION: Increasing socioeconomic deprivation is associated with higher prevalence of psychological distress and shorter consultations. This provides further evidence to support Tudor Hart's 'inverse care law' and has implications for the resourcing of primary care in deprived areas.


Assuntos
Medicina de Família e Comunidade/estatística & dados numéricos , Estresse Psicológico/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Relações Médico-Paciente , Áreas de Pobreza , Prática Profissional/organização & administração , Escócia , Fatores de Tempo
20.
Clin Oncol (R Coll Radiol) ; 15(7): 400-7, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14570088

RESUMO

AIMS: Renal cell carcinoma is commonly thought to be a radioresistant malignancy. Retrospective studies report conflicting results on the effect of radiotherapy dose escalation on response and time to progression in symptomatic metastatic disease; studies using the linear quadratic model have used alpha/beta ratios that are inappropriate for slow growing tumours. We aim to describe our experience with palliative radiotherapy in this context, relating Biological Effective Dose to outcome. MATERIALS AND METHODS: From December 1995 to April 2001, 143 independent palliative radiotherapy treatments were delivered to 78 patients in a single institution. Retrospective data was obtained on the radiotherapy schedule used, symptom response and time to symptom progression. The biological effective dose (BED) was calculated using alpha/beta ratios of 3 and 7 Gy (BED3 and BED7). The Log-Rank test was used to assess any differences in time to progression, and the Cox Proportional Hazards analysis to determine prognostic factors of time to progression. RESULTS: Overall symptomatic response rate was 73%, with most responses being partial (67%). Forty-three (38%) patients had symptomatic progression after a median follow-up of 425 days. BED (BED3 or BED7) was not significantly different across response types (complete, partial or no response; P=0.90 and 0.88, respectively) and was not predictive for time to symptomatic progression (P=0.99 for BED3 and P=0.70 for BED7). Patients with bone metastases received less total dose (P=0.001), less BED (BED3, P=0.0013, and BED7, P=0.0005) and had a significantly longer time to progression than other sites of metastases (hazard ratio (HR) 0.4; 95% confidence interval (CI) 0.2-0.7; P=0.004). Initial treatment with interferon-alpha alone in patients presenting with metastatic disease, before palliative radiotherapy, was also associated with a shorter time to symptom progression (HR 4.6; 95% CI 1.5-14.1; P=0.007). On removal of these criteria, brain metastases became a significant predictor of progression time, with an HR of 2.5 (95% CI 1.0-5.9; P=0.05), showing an increased risk of progression with brain metastases compared with metastases elsewhere. Time from primary diagnosis to development of metastatic disease was not predictive of time to symptom progression (P=0.29). CONCLUSION: Despite the widespread assumption that renal cell carcinoma is radioresistant, retrospective assessment showed high response rates to palliative radiotherapy. On the basis of our data, higher BED does not seem to be a predictor of response or of duration of response in the palliative treatment of renal cell carcinoma. Palliation of bone pain seems to be particularly durable compared with the palliation of symptoms at other sites of metastases. A trend for shorter duration of palliative effect of whole-brain radiotherapy was noted.


Assuntos
Carcinoma de Células Renais/radioterapia , Neoplasias Renais/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/secundário , Neoplasias Encefálicas/secundário , Relação Dose-Resposta à Radiação , Feminino , Humanos , Interferon-alfa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde , Estudos Retrospectivos , Compressão da Medula Espinal/etiologia , Fatores de Tempo
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