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1.
J Surg Case Rep ; 2022(11): rjac501, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36381984

RESUMEN

Primary leiomyosarcoma of the ureter is an extremely rare, aggressive malignancy of the urinary tract. This report describes a case of primary leiomyosarcoma of the distal left ureter in a middle-aged male, with no tumor recurrence achieved following resection and end-to-end ureteroureterostomy.

2.
Science ; 371(6527): 386-390, 2021 01 22.
Artículo en Inglés | MEDLINE | ID: mdl-33479150

RESUMEN

Convergent evolution provides insights into the selective drivers underlying evolutionary change. Snake venoms, with a direct genetic basis and clearly defined functional phenotype, provide a model system for exploring the repeated evolution of adaptations. While snakes use venom primarily for predation, and venom composition often reflects diet specificity, three lineages of cobras have independently evolved the ability to spit venom at adversaries. Using gene, protein, and functional analyses, we show that the three spitting lineages possess venoms characterized by an up-regulation of phospholipase A2 (PLA2) toxins, which potentiate the action of preexisting venom cytotoxins to activate mammalian sensory neurons and cause enhanced pain. These repeated independent changes provide a fascinating example of convergent evolution across multiple phenotypic levels driven by selection for defense.


Asunto(s)
Venenos Elapídicos/enzimología , Elapidae/clasificación , Elapidae/genética , Evolución Molecular , Fosfolipasas A2 Grupo IV/genética , Dolor , Células Receptoras Sensoriales/fisiología , Adaptación Biológica/genética , Animales , Venenos Elapídicos/genética , Filogenia , Células Receptoras Sensoriales/metabolismo
3.
J Mater Sci ; 52(1): 285-304, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27829689

RESUMEN

Elastic and anelastic properties of ceramic samples of multiferroic perovskites with nominal compositions across the binary join PbZr0.53Ti0.47O3-PbFe0.5Ta0.5O3 (PZT-PFT) have been assembled to create a binary phase diagram and to address the role of strain relaxation associated with their phase transitions. Structural relationships are similar to those observed previously for PbZr0.53Ti0.47O3-PbFe0.5Nb0.5O3 (PZT-PFN), but the magnitude of the tetragonal shear strain associated with the ferroelectric order parameter appears to be much smaller. This leads to relaxor character for the development of ferroelectric properties in the end member PbFe0.5Ta0.5O3. As for PZT-PFN, there appear to be two discrete instabilities rather than simply a reorientation of the electric dipole in the transition sequence cubic-tetragonal-monoclinic, and the second transition has characteristics typical of an improper ferroelastic. At intermediate compositions, the ferroelastic microstructure has strain heterogeneities on a mesoscopic length scale and, probably, also on a microscopic scale. This results in a wide anelastic freezing interval for strain-related defects rather than the freezing of discrete twin walls that would occur in a conventional ferroelastic material. In PFT, however, the acoustic loss behaviour more nearly resembles that due to freezing of conventional ferroelastic twin walls. Precursor softening of the shear modulus in both PFT and PFN does not fit with a Vogel-Fulcher description, but in PFT there is a temperature interval where the softening conforms to a power law suggestive of the role of fluctuations of the order parameter with dispersion along one branch of the Brillouin zone. Magnetic ordering appears to be coupled only weakly with a volume strain and not with shear strain but, as with multiferroic PZT-PFN perovskites, takes place within crystals which have significant strain heterogeneities on different length scales.

4.
BMJ Open ; 6(2): e009409, 2016 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-26916690

RESUMEN

OBJECTIVES: To develop an optimised 1:1 physiotherapy intervention that reflects best practice, with flexibility to tailor management to individual patients, thereby ensuring patient-centred practice. DESIGN: Mixed-methods combining evidence synthesis, expert review and focus groups. SETTING: Secondary care involving 5 UK specialist spinal centres. PARTICIPANTS: A purposive panel of clinical experts from the 5 spinal centres, comprising spinal surgeons, inpatient and outpatient physiotherapists, provided expert review of the draft intervention. Purposive samples of patients (n=10) and physiotherapists (n=10) (inpatient/outpatient physiotherapists managing patients with lumbar discectomy) were invited to participate in the focus groups at 1 spinal centre. METHODS: A draft intervention developed from 2 systematic reviews; a survey of current practice and research related to stratified care was circulated to the panel of clinical experts. Lead physiotherapists collaborated with physiotherapy and surgeon colleagues to provide feedback that informed the intervention presented at 2 focus groups investigating acceptability to patients and physiotherapists. The focus groups were facilitated by an experienced facilitator, recorded in written and tape-recorded forms by an observer. Tape recordings were transcribed verbatim. Data analysis, conducted by 2 independent researchers, employed an iterative and constant comparative process of (1) initial descriptive coding to identify categories and subsequent themes, and (2) deeper, interpretive coding and thematic analysis enabling concepts to emerge and overarching pattern codes to be identified. RESULTS: The intervention reflected best available evidence and provided flexibility to ensure patient-centred care. The intervention comprised up to 8 sessions of 1:1 physiotherapy over 8 weeks, starting 4 weeks postsurgery. The intervention was acceptable to patients and physiotherapists. CONCLUSIONS: A rigorous process informed an optimised 1:1 physiotherapy intervention post-lumbar discectomy that reflects best practice. The developed intervention was agreed on by the 5 spinal centres for implementation in a randomised controlled trial to evaluate its effectiveness.


Asunto(s)
Discectomía/rehabilitación , Vértebras Lumbares/cirugía , Participación del Paciente , Atención Dirigida al Paciente , Modalidades de Fisioterapia , Medicina Basada en la Evidencia , Grupos Focales , Humanos
5.
BMJ Open ; 6(11): e012151, 2016 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-28186932

RESUMEN

OBJECTIVE: There is a lack of high-quality evidence for physiotherapy post lumbar discectomy. Substantial heterogeneity in treatment effects may be explained by variation in quality, administration and components of interventions. An optimised physiotherapy intervention may reduce heterogeneity and improve patient benefit. The objective was to describe, analyse and evaluate an optimised 1:1 physiotherapy outpatient intervention for patients following primary lumbar discectomy, to provide preliminary insights. DESIGN: A descriptive analysis of the intervention embedded within an external pilot and feasibility trial. SETTING: Two UK spinal centres. PARTICIPANTS: Participants aged ≥18; post primary, single level, lumbar discectomy were recruited. INTERVENTION: The intervention encompassed education, advice, mobility and core stability exercises, progressive exercise, and encouragement of early return to work/activity. Patients received ≤8 sessions for ≤8 weeks, starting 4 weeks post surgery (baseline). OUTCOMES: Blinded outcome assessment at baseline and 12 weeks (post intervention) included the Roland Morris Disability Questionnaire. STarT Back data were collected at baseline. Statistical analyses summarised participant characteristics and preplanned descriptive analyses. Thematic analysis grouped related data. FINDINGS: Twenty-two of 29 allocated participants received the intervention. STarT Back categorised n=16 (55%) participants 'not at low risk'. Physiotherapists identified reasons for caution for 8 (36%) participants, commonly risk of overdoing activity (n=4, 18%). There was no relationship between STarT Back and physiotherapists' evaluation of caution. Physiotherapists identified 154 problems (mean (SD) 5.36 (2.63)). Those 'not at low risk', and/or requiring caution presented with more problems, and required more sessions (mean (SD) 3.14 (1.16)). CONCLUSIONS: Patients present differently and therefore require tailored interventions. These differences may be identified using clinical reasoning and outcome data. TRIAL REGISTRATION NUMBER: ISRCTN33808269; post results.


Asunto(s)
Discectomía/rehabilitación , Terapia por Ejercicio/métodos , Dolor de la Región Lumbar/rehabilitación , Pacientes Ambulatorios , Adulto , Evaluación de la Discapacidad , Femenino , Humanos , Vértebras Lumbares/cirugía , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Fisioterapeutas , Investigación Cualitativa , Resultado del Tratamiento , Reino Unido
6.
J Phys Condens Matter ; 27(28): 285901, 2015 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-26125192

RESUMEN

Resonant Ultrasound Spectroscopy has been used to characterize elastic and anelastic anomalies in a polycrystalline sample of multiferroic Pb(Fe(0.5)Nb(0.5))O(3) (PFN). Elastic softening begins at ~550 K, which is close to the Burns temperature marking the development of dynamical polar nanoregions. A small increase in acoustic loss at ~425 K coincides with the value of T(*) reported for polar nanoregions starting to acquire a static or quasi-static component. Softening of the shear modulus by ~30-35% through ~395-320 K, together with a peak in acoustic loss, is due to classical strain/order parameter coupling through the cubic → tetragonal → monoclinic transition sequence of ferroelectric/ferroelastic transitions. A plateau of high acoustic loss below ~320 K is due to the mobility under stress of a ferroelastic microstructure but, instead of the typical effects of freezing of twin wall motion at some low temperature, there is a steady decrease in loss and increase in elastic stiffness below ~85 K. This is attributed to freezing of a succession of strain-coupled defects with a range of relaxation times and is consistent with a report in the literature that PFN develops a tweed microstructure over a wide temperature interval. No overt anomaly was observed near the expected Néel point, ~145 K, consistent with weak/absent spin/lattice coupling but heat capacity measurements showed that the antiferromagnetic transition is actually smeared out or suppressed. Instead, the sample is weakly ferromagnetic up to ~560 K, though it has not been possible to exclude definitively the possibility that this could be due to some magnetic impurity. Overall, evidence from the RUS data is of a permeating influence of static and dynamic strain relaxation effects which are attributed to local strain heterogeneity on a mesoscopic length scale. These, in turn, must have a role in determining the magnetic properties and multiferroic character of PFN.

7.
BMJ Open ; 5(3): e006069, 2015 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-25762227

RESUMEN

OBJECTIVE: To produce free, expert-informed postoperative information for lumbar discectomy patients, satisfying UK National Health Service Information Standards. DESIGN: A mixed methods approach utilising the Delphi technique and focus groups. SETTING: Five spinal centres across the UK. PARTICIPANTS: Panel members included 23 physiotherapists, 11 patients and 17 spinal surgeons. INTERVENTION: Three rounds of questionnaires including open and closed questions and attendance at a clinician/patient focus group. RESULTS: Response rates of 85%, 26% and 35% were achieved for the Delphi rounds. Ten clinicians and six patients participated in the focus groups. Consensus for leaflet sections was achieved in round 1 and content in round 3. The focus groups informed further revisions. CONCLUSIONS: A consensually agreed, Information Standard compliant, patient lumbar discectomy leaflet was produced containing: (1) normal spine anatomy; (2) anatomy disc herniation and surgery; (3) back protection strategies and (4) frequently asked questions. Illustrations of exercises enable tailoring to the individual patient.


Asunto(s)
Consenso , Discectomía , Terapia por Ejercicio , Desplazamiento del Disco Intervertebral/cirugía , Dolor de la Región Lumbar/cirugía , Vértebras Lumbares/cirugía , Educación del Paciente como Asunto/métodos , Actividades Cotidianas , Técnica Delphi , Grupos Focales , Humanos , Desplazamiento del Disco Intervertebral/prevención & control , Dolor de la Región Lumbar/prevención & control , Folletos , Fisioterapeutas , Especialidad de Fisioterapia , Autocuidado , Columna Vertebral , Encuestas y Cuestionarios , Reino Unido
8.
Spine (Phila Pa 1976) ; 39(23): E1380-7, 2014 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-25188595

RESUMEN

STUDY DESIGN: Descriptive survey methodology employed a SurveyMonkey online questionnaire. OBJECTIVE: To evaluate UK National Health Service physiotherapy practice for lumbar spinal fusion surgery. SUMMARY OF BACKGROUND DATA: An increasing rate of surgery and high level of patient dis-satisfaction focus attention to rehabilitation of patients undergoing lumbar spinal fusion. Inconclusive, very low-quality evidence for the effectiveness of physiotherapy management after lumbar spinal fusion exists. Best practice, therefore, remains unclear. Limited comparability of outcomes and retrieval of only 2 trials reflected a lack of research and considerable heterogeneity. An evaluation of current practice is required, to inform a future trial to evaluate a best practice physiotherapy intervention. METHODS: Eligible participants were all physiotherapists working with patients undergoing spinal fusion. A previous survey and recent systematic review informed questions. Statistical analyses included responder characteristics and preplanned descriptive analyses. Thematic analysis was conducted on open-ended question data. RESULTS: The 83.5% response rate was good. Findings illustrated varied provision relating to assessment and management of patients pre- and postoperatively. Physiotherapists employed limited use of protocols or guidelines, partly attributed to the poor evidence base for this surgery. Scope of practice included exercise, advice, listing for surgery, and ordering investigations. Patient education played an important role. Patient-centered practice was important, although constraints owing to limited resources (staffing, poor evidence, base/lack of protocols) were evident. CONCLUSION: Current UK pre- and postoperative physiotherapy practice for lumbar spinal fusion is described. It is not clear whether patients who are seen by physiotherapists have improved outcomes, owing to variability of practice, physiotherapy being delivered in a range of locations at a range of times postoperatively, and limited use of outcome measures. The findings support the need for a randomized clinical trial evaluating effectiveness of a best practice physiotherapy management intervention. LEVEL OF EVIDENCE: 3.


Asunto(s)
Recolección de Datos/métodos , Vértebras Lumbares/cirugía , Modalidades de Fisioterapia/tendencias , Cuidados Posoperatorios/tendencias , Fusión Vertebral/tendencias , Humanos , Modalidades de Fisioterapia/estadística & datos numéricos , Cuidados Posoperatorios/métodos , Cuidados Posoperatorios/estadística & datos numéricos , Fusión Vertebral/efectos adversos , Reino Unido/epidemiología
9.
Ann R Coll Surg Engl ; 93(8): 639-41, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22041243

RESUMEN

INTRODUCTION: The aim of this study was to validate the use of non-contrast computed tomography (CT) with a ureteral stent in situ instead of ureteroscopy for identification of renal tract stones. METHODS: All patients who had stents inserted for renal tract stones and underwent non-contrast CT with the stent in situ followed by ureteroscopy between May 2008 and October 2009 at The Canberra hospital, Australia, were analysed retrospectively. Statistical analysis was performed to compare any differences between CT and ureteroscopy in the identification of stones. RESULTS: Overall, 57 patients were included in the study. The difference between CT and ureteroscopy findings was statistically significant. CT identification of stones with a stent in situ had a sensitivity of 86%, a specificity of 46%, a positive predictive value of 63%, a negative predictive value of 76% and an accuracy of 67%. CONCLUSIONS: Our study suggests that non-contrast CT is inferior to the 'gold standard' of ureteroscopy. It lacks sensitivity, specificity, positive predictive value, negative predictive value and accuracy. Therefore, we cannot recommend using non-contrast CT to replace ureteroscopy.


Asunto(s)
Cálculos Renales/diagnóstico , Stents , Tomografía Computarizada Espiral/normas , Cálculos Ureterales/diagnóstico , Ureteroscopía/normas , Humanos , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada Espiral/métodos
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