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2.
J Bone Oncol ; 30: 100390, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34589408

RESUMO

BACKGROUND: The efficacy and safety of cell salvage for musculoskeletal sarcoma surgery have not been reported, and concerns over re-infusion of tumour cells remain. This study aims to i) describe the intra-operative blood loss and cell salvage reinfusion volumes for lower limb sarcoma and pelvic sarcoma procedures ii) and explore whether there is evidence of tumour cells in reinfused blood. METHODS: Retrospective analysis of 109 consecutive surgical procedures for biopsy-proven sarcoma or bone metastasis performed between 1 July 2015 and 30 October 2019. Salvaged blood was processed and reinfused when intraoperative blood loss exceeded 500 ml. Primary bone tumour (n = 86(79%)) and metastasis (n = 23(21%) constituted the study group and surgeries were classified under hemipelvectomy (n = 43(39%)), lower limb endoprosthesis replacement (LLE) (n = 50(46%)) and wide excision surgery (WE) (n = 16(15%)). Microscopic examination of imprint cytology of leuco-depletion(LD) filters, and peripheral smear examination was performed for reinfused blood. RESULTS: Median (IQR) intra-operative blood loss was 1750 (600-3000) ml for hemipelvectomy, 850 (600-1200) ml for LLE, and 1000 (550-2000) ml for WE. Salvaged blood was re-infused in 102 of 109 (94%) patients. The mean (SD) volume of re-infusion was 445(4 2 5) ml for hemipelvectomy, 206(1 3 1) ml for LLE, and 184(1 0 6) ml for WE. In total, 64 of 109 (59%) patients received an allogeneic red blood transfusion within 72 h of surgery. Cytology analysis of imprints taken from the filtered blood available in 95(87%) patients and peripheral smear examination of reinfused blood available in 32(29%) patients did not reveal evidence of tumour cells on microscopic examination of any samples. CONCLUSION: Our study demonstrates that musculoskeletal sarcoma surgery is associated with significant blood loss, and cell salvage permits reinfusion of autologous blood in most patients. The cytological analysis did not reveal evidence of tumour cells in reinfused blood, consistent with other studies where cell salvage is used for cancer surgery.

3.
BMC Musculoskelet Disord ; 22(1): 18, 2021 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-33402136

RESUMO

BACKGROUND: Like with all cancers, multidisciplinary team (MDT) meetings are the norm in bone and soft tissue tumour (BST) management too. Problem in attendance of specialists due to geographical location is the one of the key barriers to effective functioning of MDTs. To overcome this problem, virtual MDTs involving videoconferencing or telemedicine have been proposed, but however this has been seldom used and tested. The COVID-19 pandemic forced the implementation of virtual MDTs in the Oxford sarcoma service in order to maintain normal service provision. We conducted a survey among the participants to evaluate its efficacy. METHODS: An online questionnaire comprising of 24 questions organised into 4 sections was circulated among all participants of the MDT after completion of 8 virtual MDTs. Opinions were sought comparing virtual MDTs to the conventional face-to-face MDTs on various aspects. A total of 36 responses were received and were evaluated. RESULTS: 72.8% were satisfied with the depth of discussion in virtual MDTs and 83.3% felt that the decision-making in diagnosis had not changed following the switch from face-to-face MDTs. About 86% reported to have all essential patient data was available to make decisions and 88.9% were satisfied with the time for discussion of patient issues over virtual platform. Three-fourths of the participants were satisfied (36.1% - highly satisfied; 38.9% - moderately satisfied) with virtual MDTs and 55.6% of them were happy to attend MDTs only by the virtual platform in the future. Regarding future, 77.8% of the participants opined that virtual MDTs would be the future of cancer care and an overwhelming majority (91.7%) felt that the present exercise would serve as a precursor to global MDTs involving specialists from abroad in the future. CONCLUSION: Our study shows that the forced switch to virtual MDTs in sarcoma care following the unprecedented COVID-19 pandemic to be a viable and effective alternative to conventional face-to-face MDTs. With effective and efficient software in place, virtual MDTs would also facilitate in forming extended MDTs in seeking opinions on complex cases from specialists abroad and can expand cancer care globally.


Assuntos
Neoplasias Ósseas/terapia , COVID-19 , Comunicação Interdisciplinar , Oncologia/organização & administração , Neoplasias Musculares/terapia , Equipe de Assistência ao Paciente/organização & administração , Sarcoma/terapia , Telemedicina/organização & administração , Comunicação por Videoconferência/organização & administração , Atitude do Pessoal de Saúde , Atitude Frente aos Computadores , Neoplasias Ósseas/diagnóstico , Tomada de Decisão Clínica , Prestação Integrada de Cuidados de Saúde/organização & administração , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Neoplasias Musculares/diagnóstico , Sarcoma/diagnóstico , Centros de Atenção Terciária
4.
Clin Orthop Relat Res ; 479(5): 1158-1166, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33196585

RESUMO

BACKGROUND: Delivering uninterrupted cancer treatment to patients with musculoskeletal tumors has been essential during the rapidly evolving coronavirus 2019 (COVID-19) pandemic, as delays in management can be detrimental. Currently, the risk of contracting COVID-19 in hospitals when admitted for surgery and the susceptibility due to adjuvant therapies and associated mortality due to COVID-19 is unknown, but knowledge of these potential risks would help treating clinicians provide appropriate cancer care. QUESTIONS/PURPOSES: (1) What is the risk of hospital-acquired COVID-19 in patients with musculoskeletal tumors admitted for surgery during the initial period of the pandemic? (2) What is the associated mortality in patients with musculoskeletal tumors who have contracted COVID-19? (3) Are patients with musculoskeletal tumors who have had neoadjuvant therapy (chemotherapy or radiation) preoperatively at an increased risk of contracting COVID-19? (4) Is a higher American Society of Anesthesiologists (ASA) grade in patients with musculoskeletal tumors associated with an increased risk of contracting COVID-19 when admitted to the hospital for surgery? METHODS: This retrospective, observational study analyzed patients with musculoskeletal tumors who underwent surgery in one of eight specialist centers in the United Kingdom, which included the five designated cancer centers in England, one specialist soft tissue sarcoma center, and two centers from Scotland between March 12, 2020 and May 20, 2020. A total of 347 patients were included, with a median (range) age of 53 years (10 to 94); 60% (207 of 347) were men, and the median ASA grade was II (I to IV). These patients had a median hospital stay of 8 days (0 to 53). Eighteen percent (61 of 347) of patients had received neoadjuvant therapy (8% [27] chemotherapy, 8% [28] radiation, 2% [6] chemotherapy and radiation) preoperatively. The decision to undergo surgery was made in adherence with United Kingdom National Health Service and national orthopaedic oncology guidelines, but specific data with regard to the number of patients within each category are not known. Fifty-nine percent (204 of 347) were negative in PCR testing done 48 hours before the surgical procedure; the remaining 41% (143 of 347) were treated before preoperative PCR testing was made mandatory, but these patients were asymptomatic. All patients were followed for 30 days postoperatively, and none were lost to follow-up during that period. The primary outcome of the study was contracting COVID-19 in the hospital after admission. The secondary outcome was associated mortality after contracting COVID-19 within 30 days of the surgical procedure. In addition, we assessed whether there is any association between ASA grade or neoadjuvant treatment and the chances of contracting COVID-19 in the hospital. Electronic patient record system and simple descriptive statistics were used to analyze both outcomes. RESULTS: Four percent (12 of 347) of patients contracted COVID-19 in the hospital, and 1% (4 of 347) of patients died because of COVID-19-related complications. Patients with musculoskeletal tumors who contracted COVID-19 had increased mortality compared with patients who were asymptomatic or tested negative (odds ratio 55.33 [95% CI 10.60 to 289.01]; p < 0.001).With the numbers we had, we could not show that adjuvant therapy had any association with contracting COVID-19 while in the hospital (OR 0.94 [95% CI 0.20 to 4.38]; p = 0.93). Increased ASA grade was associated with an increased likelihood of contracting COVID-19 (OR 58 [95% CI 5 to 626]; p < 0.001). CONCLUSION: Our results show that surgeons must be mindful and inform patients that those with musculoskeletal tumors are at risk of contracting COVID-19 while admitted to the hospital and some may succumb to it. Hospital administrators and governmental agencies should be aware that operations on patients with lower ASA grade appear to have lower risk and should consider restructuring service delivery to ensure that procedures are performed in designated COVID-19-restricted sites. These measures may reduce the likelihood of patients contracting the virus in the hospital, although we cannot confirm a benefit from this study. Future studies should seek to identify factors influencing these outcomes and also compare surgical complications in those patients with and without COVID-19. LEVEL OF EVIDENCE: Level III, therapeutic study.


Assuntos
Neoplasias Ósseas/terapia , COVID-19/complicações , Infecção Hospitalar/complicações , Neoplasias de Tecidos Moles/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/mortalidade , COVID-19/mortalidade , Criança , Infecção Hospitalar/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Pandemias , Estudos Retrospectivos , Fatores de Risco , SARS-CoV-2 , Neoplasias de Tecidos Moles/mortalidade , Reino Unido/epidemiologia , Adulto Jovem
5.
J Clin Orthop Trauma ; 11(Suppl 4): S419-S422, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32774004

RESUMO

The COVID-19 (Coronavirus disease 2019) pandemic has caused an unprecedented strain on healthcare systems across the globe. Apart from being a major hurdle to delivery of basic healthcare services, this may be associated with potential harm for cancer patients. Usually being immunocompromised, cancer patients are at a higher risk of contracting the disease and with hospitals being a potential source of the infection, an urgent need to reorganise the structure of delivery of cancer care is essential. Cancer departments must balance patient care whilst also minimising transmission among patients and healthcare professionals. The Oxford Sarcoma Service was re-structured based on the guidelines issued by the National Health Service (NHS) and the British Orthopaedic Oncology Society (BOOS) to deliver unhindered care to patients. Prioritising patients who needed urgent surgery, weighing the risk-benefit ratio while delivering adjuvant treatments and conducting regular virtual multi-disciplinary team (MDT) meetings combined with personal protection equipment (PPE) usage by all involved healthcare workers were salient features in terms of ensuring the delivery of effective care during the COVID-19 pandemic. Our new model of modus operandi during this global crisis was effective in delivering high standard of care to patients and might serve as a guide to similar units managing bone and soft tissue tumours.

6.
Int Orthop ; 44(9): 1853-1858, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32728926

RESUMO

PURPOSE: Deferring cancer surgery can have profound adverse effects including patient mortality. During the COVID-19 pandemic, departmental reorganisation and adherence to evolving guidelines enabled provision of uninterrupted surgical care to patients with bone and soft tissue tumours (BST) in need of surgery. We reviewed the outcomes of surgeries on BST during the first two months of the pandemic at one of the tertiary BST centres in the UK. MATERIALS AND METHODS: Between 12 March 2020 and 12 May 2020, 56 patients of a median age of 57 years (18-87) underwent surgery across two sites: index hospital (n = 27) and COVID-free facility (n = 29). Twenty-five (44.6%) patients were above the age of 60 years and 20 (35.7%) patients were in ASA III and ASA IV category. The decision to offer surgery was made in adherence with the guidelines issued by the NHS, BOOS and BSG. RESULTS: At a minimum follow-up of 30 days post-surgery, 54 (96.4%) patients were recovering well. Thirteen patients (23.2%) had post-operative complications which included four (7.1%) patients developing pulmonary embolism. The majority of complications (12/13 = 92.7%) occurred in ASA III and IV category patients. Four (7.1%) patients contracted COVID-19, of which three required escalation of care due to pulmonary complications and two (3.6%) died. Patients < 60 years of age had significantly less complications than those > 60 years (p < 0.001). Patients operated on in the COVID-free facility had fewer complications compared with those operated on at the index hospital (p < 0.027). CONCLUSION: In spite of the favourable results in majority of our patients, our study shows that patients with sarcoma operated at the height of the pandemic are at a risk of contracting COVID-19 and also having associated with mortality. The use of a COVID-free facility, surgery in patients < 60 60 years and in ASA I & II category are associated with better outcomes. If a second wave occurs, a serious consideration should be given to ways of minimising the risk of contracting COVID-19 in these vulnerable patients either by using COVID-free facilities or delaying treatment until peak of infection has passed.


Assuntos
Neoplasias Ósseas/cirurgia , COVID-19 , Pandemias , Segurança do Paciente , Neoplasias de Tecidos Moles/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2 , Sarcoma/patologia , Sarcoma/cirurgia , Adulto Jovem
7.
J Anat ; 237(6): 1177-1184, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32706924

RESUMO

Macroscopic anatomy has traditionally been taught using cadaveric material, lectures and a variable amount of additional resources such as online modules. Anatomical models have also been used to assist in teaching. Of these, traditional plastic models have been shown to be effective educational tools, yet have significant drawbacks such as a lack of anatomical detail and texturisation. Three-dimensional (3D) printed models stand to solve these problems and widen access to high-quality anatomical teaching. This paper outlines the use of 3D multi-planar imaging (CT and MRI) as a framework to develop an accurate model of the retroperitoneum. CT and MRI scans were used to construct a virtual 3D model of the retroperitoneum. This was printed locally as a full-size colour model for use in medical education. We give a complete account of the processes and software used. This study is amongst the first of a series in which we will document the newly formed Oxford Library of Anatomy. This series will provide the methodology for the production of models from CT and MRI scans, and the Oxford Library of Anatomy will provide a complete series of some of the most complex anatomical areas and ones which degrade quickly when a real cadaver is being used. In our own internal experience, the models are highly accurate, reproducible and durable, as compared to prosected specimens. We hope they will form an important adjunct in the teaching of the subject.


Assuntos
Abdome/anatomia & histologia , Imageamento Tridimensional/métodos , Região Lombossacral/anatomia & histologia , Modelos Anatômicos , Pelve/anatomia & histologia , Abdome/diagnóstico por imagem , Educação de Graduação em Medicina , Humanos , Região Lombossacral/diagnóstico por imagem , Imageamento por Ressonância Magnética , Pelve/diagnóstico por imagem , Impressão Tridimensional , Tomografia Computadorizada por Raios X
8.
Ultrasonics ; 104: 106111, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32146382

RESUMO

The deposition of increased volumes of Cu down an interconnect through-hole via (THV) of a Printed Circuit Board (PCB) is highly desirable for the fabrication of increasing component density and PCB stacks. A quality metric, called micro-throwing power, characterises the volume of Cu that can be deposited within a THV. In this paper, we analyse the influence of 1 ± 0.05 MHz megasonic (MS) assisted agitation applied to copper (Cu) electroplating baths on the micro-throwing ability of a standard, non-filling Cu electroplating solution. Our results indicate that megasonic agitation is shown to increase the Cu deposition volume within a THV by 45% for an increase of MS pressure from 225 W to 450 W, highlighting the significance of acoustic pressure as a key parameter to control MS THV plating volume. Bulk fluid flow rate within a 500 L plating tank is shown to increase by 150% due to Eckhart acoustic streaming mechanisms, compared to existing bath agitation techniques and panel movement. From MS plating experiments and COMSOLTM finite element acoustic scattering simulations, transducer orientation is shown to influence plating performance, with higher-order acoustic resonant modes forming within THVs identified as the cause. Simulations indicate that higher potential acoustic energy was coupled into a 0.200 mm diameter THV cavity, width-to-length aspect ratio (ar): 8:1, than a larger cavity of diameter 0.475 mm, ar 3.4:1. The maximum acoustic energy coupled into THV cavity is observed for a wavefront propagating along the axis of the cavity entrance, indicating an ideal alignment for the MS plating setup.

9.
Opt Express ; 27(22): 31425-31434, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31684377

RESUMO

We investigate the impact of the growth conditions of AlGaAsSb cladding layers on the properties of interband cascade lasers (ICLs). For an optimized structure emitting at 3.3 µm, we achieve an internal quantum efficiency of 65% per stage in good agreement with conventional ICL using InAs/AlSb superlattice cladding layers, in spite of internal losses of 15 cm-1 due to higher optical losses in the n-type AlGaAsSb alloys. Finally, we report a narrow ridge ICL emitting at 3.33 µm operating in continuous wave up to 80°C that produces 1 mW/uncoated facet at 80 °C, 10 mW at 40 °C and more than 12 mW at 20°C.

10.
Ultrason Sonochem ; 42: 434-444, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29429689

RESUMO

In this research experimental and simulated analysis investigates the influence of megasonic (MS; 1 ±â€¯0.05 MHz) acoustic-assisted electroplating techniques, with respect to the fabrication of through-hole via (THV) and blind-via (BV) interconnects for the Printed Circuit Board (PCB) industry. MS plating of copper down THV and BV interconnects was shown to produce measurable benefits such as increased connectivity throughout a PCB and cost savings. More specifically, a 700% increase of copper plating rate was demonstrated for THVs of 175 µm diameter and depth-to-width aspect ratio (ar) of 5.7:1, compared with electrodeposition under no-agitation conditions. For BVs, a 60% average increase in copper thickness deposition in 150 µm and 200 µm, ar 1:1, was demonstrated against plating under standard manufacturing conditions including bubble agitation and panel movement. Finite element modelling simulations of acoustic scattering revealed 1st harmonic influence for plating rate enhancement.

11.
Rev Sci Instrum ; 87(11): 11E129, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910342

RESUMO

The synthetic aperture microwave imaging diagnostic has been operating on the MAST experiment since 2011. It has provided the first 2D images of B-X-O mode conversion windows and showed the feasibility of conducting 2D Doppler back-scattering experiments. The diagnostic heavily relies on field programmable gate arrays to conduct its work. Recent successes and newly gained experience with the diagnostic have led us to modify it. The enhancements will enable pitch angle profile measurements, O and X mode separation, and the continuous acquisition of 2D DBS data. The diagnostic has also been installed on the NSTX-U and is acquiring data since May 2016.

12.
Rev Sci Instrum ; 87(11): 11D902, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27910558

RESUMO

The Synthetic Aperture Microwave Imaging (SAMI) system is a novel diagnostic consisting of an array of 8 independently phased antennas. At any one time, SAMI operates at one of the 16 frequencies in the range 10-34.5 GHz. The imaging beam is steered in software post-shot to create a picture of the entire emission surface. In SAMI's active probing mode of operation, the plasma edge is illuminated with a monochromatic source and SAMI reconstructs an image of the Doppler back-scattered (DBS) signal. By assuming that density fluctuations are extended along magnetic field lines, and knowing that the strongest back-scattered signals are directed perpendicular to the density fluctuations, SAMI's 2-D DBS imaging capability can be used to measure the pitch of the edge magnetic field. In this paper, we present preliminary pitch angle measurements obtained by SAMI on the Mega Amp Spherical Tokamak (MAST) at Culham Centre for Fusion Energy and on the National Spherical Torus Experiment Upgrade at Princeton Plasma Physics Laboratory. The results demonstrate encouraging agreement between SAMI and other independent measurements.

13.
Leukemia ; 30(6): 1246-54, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26847027

RESUMO

Precursor-B-cell receptor (pre-BCR) signaling and spleen tyrosine kinase (SYK) recently were introduced as therapeutic targets for patients with B-cell acute lymphoblastic leukemia (B-ALL), but the importance of this pathway in B-ALL subsets and mechanism of downstream signaling have not fully been elucidated. Here, we provide new detailed insight into the mechanism of pre-BCR signaling in B-ALL. We compared the effects of pharmacological and genetic disruption of pre-BCR signaling in vitro and in mouse models for B-ALL, demonstrating exquisite dependency of pre-BCR(+) B-ALL, but not other B-ALL subsets, on this signaling pathway. We demonstrate that SYK, PI3K/AKT, FOXO1 and MYC are important downstream mediators of pre-BCR signaling in B-ALL. Furthermore, we define a characteristic immune phenotype and gene expression signature of pre-BCR(+) ALL to distinguish them from other B-ALL subsets. These data provide comprehensive new insight into pre-BCR signaling in B-ALL and corroborate pre-BCR signaling and SYK as promising new therapeutic targets in pre-BCR(+) B-ALL.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Células Precursoras de Linfócitos B/química , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Proteína Forkhead Box O1/metabolismo , Xenoenxertos , Humanos , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patologia , Proteínas Proto-Oncogênicas c-myc/metabolismo , Quinase Syk/metabolismo
14.
J Math Biol ; 64(7): 1225-51, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21706222

RESUMO

The phylogenetic tree (PT) problem has been studied by a number of researchers as an application of the Steiner tree problem, a well-known network optimisation problem. Of all the methods developed for phylogenies the maximum parsimony (MP) method is a simple and commonly used method because it relies on directly observable changes in the input nucleotide or amino acid sequences. In this paper we show that the non-uniqueness of the evolutionary pathways in the MP method leads us to consider a new model of PTs. In this so-called probability representation model, for each site a node in a PT is modelled by a probability distribution of nucleotide or amino acid states, and hence the PT at a given site is a probability Steiner tree, i.e. a Steiner tree in a high-dimensional vector space. In spite of the generality of the probability representation model, in this paper we restrict our study to constructing probability phylogenetic trees (PPT) using the parsimony criterion, as well as discussing and comparing our approach with the classical MP method. We show that for a given input set although the optimal topology as well as the total tree length of the PPT is the same as the PT constructed by the classical MP method, the inferred ancestral states and branch lengths are different and the results given by our method provide a plausible alternative to the classical ones.


Assuntos
Modelos Estatísticos , Filogenia , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Molecular , Modelos Genéticos , Dados de Sequência Molecular , Probabilidade
15.
J Comput Biol ; 18(1): 67-80, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20624099

RESUMO

The problem of inferring phylogenies (phylogenetic trees) is one of the main problems in computational biology. There are three main methods for inferring phylogenies-Maximum Parsimony (MP), Distance Matrix (DM) and Maximum Likelihood (ML), of which the MP method is the most well-studied and popular method. In the MP method the optimization criterion is the number of substitutions of the nucleotides computed by the differences in the investigated nucleotide sequences. However, the MP method is often criticized as it only counts the substitutions observable at the current time and all the unobservable substitutions that really occur in the evolutionary history are omitted. In order to take into account the unobservable substitutions, some substitution models have been established and they are now widely used in the DM and ML methods but these substitution models cannot be used within the classical MP method. Recently the authors proposed a probability representation model for phylogenetic trees and the reconstructed trees in this model are called probability phylogenetic trees. One of the advantages of the probability representation model is that it can include a substitution model to infer phylogenetic trees based on the MP principle. In this paper we explain how to use a substitution model in the reconstruction of probability phylogenetic trees and show the advantage of this approach with examples.


Assuntos
Modelos Estatísticos , Filogenia , Algoritmos , Animais , Sequência de Bases , Humanos , Dados de Sequência Molecular , Probabilidade
16.
Intensive Care Med ; 34(8): 1469-76, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18350270

RESUMO

OBJECTIVES: To measure the extent of dilution of helium-oxygen (heliox) by room air when given via high concentration reservoir mask to spontaneously breathing subjects. Substantial dilution of heliox by room air under these circumstances might alter its physical properties sufficiently to negate any potential clinical benefit in obstructive respiratory failure. DESIGN: Healthy volunteers breathing different concentrations of helium in oxygen via two different masks in a randomised crossover design. SETTING: Operating theatre in a university hospital. PATIENTS AND PARTICIPANTS: Six healthy volunteers. INTERVENTIONS: The concentrations of helium, nitrogen and oxygen were measured in the trachea of each volunteer using a mass spectrometer during normal breathing, hyperventilation and hypoventilation. MEASUREMENTS AND RESULTS: During normal breathing of Heliox21 (79% helium) via a standard non-rebreathe reservoir mask, within subject median percentage tracheal helium was 37.2% (range 29.3-52.2%) and nitrogen was 41.7% (27.4-49.4%). Air entrainment was affected by changes in breathing pattern: tracheal nitrogen concentration was greater during hyperventilation (55.4%; range 49.4-63.5%) and less during hypoventilation (33.1%; range 24.6-39.6%, p=0.043). Tracheal nitrogen could be almost completely abolished by administering heliox via a tightly fitting cushioned facemask, even during hyperventilation (2.2%; range 0.6-6.1%, p=0.028). CONCLUSIONS: Heliox administration via a standard high-concentration reservoir mask leads to significant dilution by room air. For the full potential benefits of heliox to be realised in spontaneously breathing patients, it should be administered via a system that achieves a gas tight seal, with no leaks between the delivery device and the surroundings.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Hélio/administração & dosagem , Hélio/farmacologia , Máscaras , Oxigênio/administração & dosagem , Oxigênio/farmacologia , Traqueia/efeitos dos fármacos , Adulto , Estudos Cross-Over , Relação Dose-Resposta a Droga , Desenho de Equipamento , Feminino , Humanos , Masculino , Respiração/efeitos dos fármacos , Volume de Ventilação Pulmonar/efeitos dos fármacos
17.
Inorg Chem ; 47(5): 1607-15, 2008 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-18247541

RESUMO

PalladiumII and nickelII halide complexes of the ferrocenyl polyphosphines 1,1',2,3-tetrakis(diphenylphosphino)ferrocene (1), and 1,1',2-tris(diphenylphosphino)-4-tert-butylferrocene (5) were prepared and characterized by multinuclear NMR. The metallo-ligand 1, the palladium [Pd2Cl4(1)] (3b) and nickel [NiCl2(5)] (6) coordination complexes were additionally characterized by X-ray diffraction crystallography. The behavior of 1 toward coordination to nickel and palladium was surprisingly different because the coordination of a second metal center after the initial 1,2-phosphorus-bonding of nickel was markedly difficult. The preference of nickel for 1,2-P coordination on 1,1'-bonding was confirmed by the exclusive formation of 6 from 5. The changes noted between the solid state structure of the ligand 1 and the structure obtained for the dinuclear palladium complex 3b reveal the rotational flexibility of this tetraphosphine. This flexibility is at the origin of the unique framework for a metallocenic dinuclear metal complex in which both coexist a 1,1'-heteroannular chelating P-bonding and a 2,3-homoannular chelating P-bonding with two palladium centers. Some reported specimens of ferrocenyl polyphosphines of constrained geometry have previously revealed that phosphorus lone pair overlap can lead to very intense "through-space" 31P31P nuclear spin-spin coupling constants (JPP) ( J. Am. Chem. Soc. 2004, 126 (35), 11077-11087] in solution phase. In these cases, an internuclear distance between heteroannular phosphorus atoms below 4.9 A, with an adequate orientation of the lone-pairs in the solid state and in solution, was a necessary parameter. The flexibility of the new polyphosphines 1 and 5 does not allow that spatial proximity (internuclear distances between heteroannular phosphorus above 5.2 A in the solid state); accordingly the expected through-space nuclear spin-spin coupling constants were not detected in any of their coordination complexes nor in 1.

18.
Int J Gynecol Cancer ; 16 Suppl 1: 236-40, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16515597

RESUMO

The occurrence of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) has been reported after treatment with cytotoxic alkylating agent-based chemotherapy for solid tumors. We report a patient with metastatic ovarian carcinoma treated with carboplatin and paclitaxel, who developed secondary acute erythroid leukemia. The overall survival of patients with stage III and IV ovarian cancer has increased in the past decade. Monitoring of the long-term outcome of paclitaxel- and platinum-based regimens is warranted, particularly with regard to monitoring the development of secondary MDS and/or AML. The incidence and outcome of secondary leukemia in the setting of active ovarian carcinoma is reviewed.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Leucemia Eritroblástica Aguda/induzido quimicamente , Neoplasias Hepáticas/terapia , Neoplasias Epiteliais e Glandulares/terapia , Neoplasias Ovarianas/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Braço , Bussulfano/administração & dosagem , Carboplatina/administração & dosagem , Carboplatina/efeitos adversos , Citarabina/administração & dosagem , Evolução Fatal , Feminino , Procedimentos Cirúrgicos em Ginecologia , Humanos , Idarubicina/administração & dosagem , Leiomiossarcoma/cirurgia , Leucemia Eritroblástica Aguda/terapia , Neoplasias Hepáticas/secundário , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Neoplasia Residual , Neoplasias Epiteliais e Glandulares/secundário , Segunda Neoplasia Primária , Neoplasias Ovarianas/patologia , Paclitaxel/administração & dosagem , Paclitaxel/efeitos adversos , Reoperação , Transplante de Células-Tronco , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados
19.
Acta Orthop ; 76(4): 513-6, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16195067

RESUMO

BACKGROUND: Whilst it is well known that fractures of the pelvic rami in the elderly are frequently associated with posterior ring injuries, the extent of this second injury is less well known. We evaluated this question by MRI scanning a group of elderly patients presenting at our unit with pelvic rami fractures. PATIENTS AND METHODS: We investigated 50 consecutive elderly patients (45 women) with fractures of the pelvic rami using an MRI scan of the pelvis in order to assess the competency of the pelvic ring. RESULTS: On MRI, 45 (95% CI 42-48) patients had a sacral fracture. At 5-month follow-up, 39 (of 41 reviewed) still complained of posterior sacral tenderness. INTERPRETATION: Pelvic rami fractures in the elderly are nearly always associated with posterior ring injuries. This probably explains why these patients take longer to rehabilitate than might be expected if only the anterior injury is considered, and it also explains why they experience long-term back pain.


Assuntos
Fraturas Ósseas/diagnóstico , Ossos Pélvicos/lesões , Osso Púbico/lesões , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Fraturas Ósseas/patologia , Fraturas Ósseas/reabilitação , Humanos , Imageamento por Ressonância Magnética , Masculino , Ossos Pélvicos/diagnóstico por imagem , Osso Púbico/diagnóstico por imagem , Radiografia , Recuperação de Função Fisiológica
20.
Arch Dis Child ; 90(3): 288-91, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15723920

RESUMO

AIMS: To determine whether the use of negative pressure ventilation (NPV) was associated with a lower rate of endotracheal intubation in infants with recurrent apnoea secondary to acute bronchiolitis. METHODS: Retrospective review of two paediatric intensive care units (PICU) databases and case notes; one PICU offered NPV. RESULTS: Fifty two infants with bronchiolitis related apnoea were admitted to the two PICUs (31 to the NPV centre). There were no significant differences between infants in the two centres in age and weight on admission, gestational age at birth, birth weight, history of apnoea of prematurity or chronic lung disease, days ill before referral, respiratory syncytial virus status, oxygen requirement before support, and numbers retrieved from secondary care centres. Respiratory support was provided to all 31 infants in the NPV centre (23 NPV, 8 PPV), and 19/21 in the non-NPV centre (18 PPV, 1 CPAP); the NPV centre had lower rates of endotracheal intubation rates (8/31 v 18/21), shorter durations of stay (median 2 v 7 days), and less use of sedation (16/31 v 18/21). In the two years after the NPV centre discontinued use of NPV, 14/17 (82%) referred cases were intubated, with a median PICU stay of 7.5 days. CONCLUSIONS: The use of NPV was associated with a reduced rate of endotracheal intubation, and shorter PICU stay. A prospective randomised controlled trial of the use of NPV in the treatment of bronchiolitis related apnoea is warranted.


Assuntos
Apneia/reabilitação , Bronquiolite/complicações , Apneia/etiologia , Feminino , Humanos , Lactente , Recém-Nascido , Unidades de Terapia Intensiva Pediátrica , Terapia Intensiva Neonatal , Tempo de Internação , Masculino , Recidiva , Respiração Artificial , Resultado do Tratamento , Respiradores de Pressão Negativa
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