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1.
ACS Nano ; 16(12): 19755-19788, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36449447

RESUMO

Smart wearable electronic textiles (e-textiles) that can detect and differentiate multiple stimuli, while also collecting and storing the diverse array of data signals using highly innovative, multifunctional, and intelligent garments, are of great value for personalized healthcare applications. However, material performance and sustainability, complicated and difficult e-textile fabrication methods, and their limited end-of-life processability are major challenges to wide adoption of e-textiles. In this review, we explore the potential for sustainable materials, manufacturing techniques, and their end-of-the-life processes for developing eco-friendly e-textiles. In addition, we survey the current state-of-the-art for sustainable fibers and electronic materials (i.e., conductors, semiconductors, and dielectrics) to serve as different components in wearable e-textiles and then provide an overview of environmentally friendly digital manufacturing techniques for such textiles which involve less or no water utilization, combined with a reduction in both material waste and energy consumption. Furthermore, standardized parameters for evaluating the sustainability of e-textiles are established, such as life cycle analysis, biodegradability, and recyclability. Finally, we discuss the current development trends, as well as the future research directions for wearable e-textiles which include an integrated product design approach based on the use of eco-friendly materials, the development of sustainable manufacturing processes, and an effective end-of-the-life strategy to manufacture next generation smart and sustainable wearable e-textiles that can be either recycled to value-added products or decomposed in the landfill without any negative environmental impacts.


Assuntos
Têxteis , Dispositivos Eletrônicos Vestíveis , Eletrônica
2.
J Digit Imaging ; 35(4): 739-742, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35995901

RESUMO

In the early 2000s, the radiology community was awakened to the limitations of electronic media (CDs, DVDs) for exchanging imaging exams. Clinicians frustrated by the time-consuming task of opening discs, while Internet-based exchange of music, photos, and videos were becoming more widespread. The RSNA, which had extensive experience working on interoperability issues in medical imaging, began to look for opportunities to address the issue. In 2007, in the wake of the financial crisis, the National Institute of Biomedical Imaging and Bioengineering (NIBIB) issued an RFP to address Internet-based exchange of medical images. The RFP defined requirements for the network, including that it needed to be patient controlled and standards based. The RSNA was awarded funding for what came to be known as RSNA ImageShare. Over the next 8 years, the RSNA worked in partnership with several vendors and academic institutions to create a network for sharing image-enabled personal health records (PHR). The foundation of interoperability standards used in ImageShare was provided by Integrating the Healthcare Enterprise (IHE), a standards-development organization with which RSNA has had a long association. In 2018 and 2019, the RSNA looked at what had been accomplished and asked if we could take that next step at a national level and promote a solution by which any standards-compliant party could exchange imaging exams through an HIE mechanism.


Assuntos
Registros de Saúde Pessoal , Sistemas de Informação em Radiologia , Radiologia , Diagnóstico por Imagem , Humanos , Radiografia
3.
Adv Sustain Syst ; 6(1): 2100176, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34901387

RESUMO

Personal protective clothing is critical to shield users from highly infectious diseases including COVID-19. Such clothing is predominantly single-use, made of plastic-based synthetic fibers such as polypropylene and polyester, low cost and able to provide protection against pathogens. However, the environmental impacts of synthetic fiber-based clothing are significant and well-documented. Despite growing environmental concerns with single-use plastic-based protective clothing, the recent COVID-19 pandemic has seen a significant increase in their use, which could result in a further surge of oceanic plastic pollution, adding to the mass of plastic waste that already threatens marine life. In this review, the nature of the raw materials involved in the production of such clothing, as well as manufacturing techniques and the personal protective equipment supply chain are briefly discussed. The environmental impacts at critical points in the protective clothing value chain are identified from production to consumption, focusing on water use, chemical pollution, CO2 emissions, and waste. On the basis of these environmental impacts, the need for fundamental changes in the business model is outlined, including increased usage of reusable protective clothing, addressing supply chain "bottlenecks", establishing better waste management, and the use of sustainable materials and processes without associated environmental problems.

4.
World Neurosurg ; 155: 96-108, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34217862

RESUMO

BACKGROUND: Stereoelectroencephalography (sEEG) is an increasingly popular surgical technique used clinically to study neural circuits involved in medication-refractory epilepsy, and it is concomitantly used in the scientific investigation of neural circuitry underlying behavior. METHODS: Using PRISMA guidelines, the U.S. National Library of Medicine at the National Institutes of Health PubMed database was queried for investigational or therapeutic applications of sEEG in human subjects. Abstracts were analyzed independently by 2 authors for inclusion or exclusion. RESULTS: The study search identified 752 articles, and after exclusion criteria were applied, 8 studies were selected for in-depth review. Among those 8 studies, 122 patients were included, with indications ranging from schizophrenia to Parkinson disease. All the included studies were single-institution case series representing level IV scientific evidence. CONCLUSIONS: sEEG is an important method in epilepsy surgery that could be applied to other neurologic and psychiatric diseases. Information from these studies could provide additional pathophysiologic information and lead to further development and refinement of neuromodulation therapies for such conditions.


Assuntos
Encéfalo/fisiopatologia , Encéfalo/cirurgia , Eletroencefalografia/métodos , Epilepsia/fisiopatologia , Epilepsia/cirurgia , Técnicas Estereotáxicas , Mapeamento Encefálico/métodos , Mapeamento Encefálico/tendências , Eletroencefalografia/tendências , Epilepsia/diagnóstico , Humanos , Doença de Parkinson/diagnóstico , Doença de Parkinson/fisiopatologia , Doença de Parkinson/cirurgia , Psicocirurgia/métodos , Psicocirurgia/tendências , Esquizofrenia/diagnóstico , Esquizofrenia/fisiopatologia , Esquizofrenia/cirurgia , Técnicas Estereotáxicas/tendências
5.
ACS Nano ; 14(10): 12313-12340, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-32866368

RESUMO

Personal protective equipment (PPE) is critical to protect healthcare workers (HCWs) from highly infectious diseases such as COVID-19. However, hospitals have been at risk of running out of the safe and effective PPE including personal protective clothing needed to treat patients with COVID-19, due to unprecedented global demand. In addition, there are only limited manufacturing facilities of such clothing available worldwide, due to a lack of available knowledge about relevant technologies, ineffective supply chains, and stringent regulatory requirements. Therefore, there remains a clear unmet need for coordinating the actions and efforts from scientists, engineers, manufacturers, suppliers, and regulatory bodies to develop and produce safe and effective protective clothing using the technologies that are locally available around the world. In this review, we discuss currently used PPE, their quality, and the associated regulatory standards. We survey the current state-of-the-art antimicrobial functional finishes on fabrics to protect the wearer against viruses and bacteria and provide an overview of protective medical fabric manufacturing techniques, their supply chains, and the environmental impacts of current single-use synthetic fiber-based protective clothing. Finally, we discuss future research directions, which include increasing efficiency, safety, and availability of personal protective clothing worldwide without conferring environmental problems.


Assuntos
Transmissão de Doença Infecciosa/prevenção & controle , Pessoal de Saúde , Equipamento de Proteção Individual/normas , Humanos , Equipamento de Proteção Individual/classificação , Equipamento de Proteção Individual/virologia , Guias de Prática Clínica como Assunto , Têxteis/normas
6.
J Digit Imaging ; 33(1): 6-16, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31768898

RESUMO

This white paper explores the considerations of standards-based interoperability of medical images between organizations, patients, and providers. In this paper, we will look at three different standards-based image exchange implementations that have been deployed to facilitate exchange of images between provider organizations. The paper will describe how each implementation uses applicable technology and standards; the image types that are included; and the governance policies that define participation, access, and trust. Limitations of the solution or non-standard approaches to solve challenges will also be identified. Much can be learned from successes elsewhere, and those learnings will point to recommendations of best practices to facilitate the adoption of image exchange.


Assuntos
Troca de Informação em Saúde , Diagnóstico por Imagem , Registros Eletrônicos de Saúde , Humanos , Projetos Piloto , Radiologia
7.
Materials (Basel) ; 11(11)2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30355960

RESUMO

Greige cotton (GC) has attracted interest in recent years as an eco-friendly, functional fiber for use in nonwoven topsheet materials. GC imparts favorable fluid management and sensorial properties associated with urinary liquid transport and indices related to comfort in wearable incontinence nonwovens. Nonwoven GC has material surface polarity, an ambient moisture content, and a lipid/polysaccharide matrix that imparts positive fluid mechanic properties applicable to incontinence management topsheet materials. However, a better understanding of the connection between functionality and compositional aspects of molecular, mechanical, and material property relations is still required to employ structure/function relations beyond a priori design. Thus, this study focuses on the relation of key indices of material fluid and sensorial functions to nonwoven topsheet composition. Greige cotton, polypropylene, bleached cotton, and polyester fiber blends were hydroentangled at 60, 80, and 100 bar. Greige cotton polypropylene and bleached cotton were blended at ratios to balance surface polarity, whereas low percentages of polyester were added to confer whiteness properties. Electrokinetic and contact angle measurements were obtained for the hydroentangled nonwovens to assess surface polarity in light of material composition. Notably, materials demonstrated a relation of hydrophobicity to swelling as determined electrokinetically by Δζ, ζplateau, and contact angles greater than 90°. Subsequently, three blended nonwoven fabrics were selected to assess effects on fluid management properties including topsheet performance indices of rewet, strikethrough, and fluid handling (rate and efficiency of transport to the absorbent core). These materials aligned well with commercial topsheet fluid mechanics. Using the Leeds University Fabric Handle Evaluation System (LUFHES), the nonwovens were tested for total fabric hand. The results of the LUFHES measurements are discussed in light of fiber contributions. Fiber ratios were found to correlate well with improvement in softness, flexibility, and formability. This study provides insights that improves the understanding of the multifunctional properties accessible with greige cotton toward decisions valuable to selecting greige cotton as an environmentally friendly fiber for nonwoven topsheets.

8.
ACS Nano ; 11(12): 12266-12275, 2017 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-29185706

RESUMO

Graphene-based wearable e-textiles are considered to be promising due to their advantages over traditional metal-based technology. However, the manufacturing process is complex and currently not suitable for industrial scale application. Here we report a simple, scalable, and cost-effective method of producing graphene-based wearable e-textiles through the chemical reduction of graphene oxide (GO) to make stable reduced graphene oxide (rGO) dispersion which can then be applied to the textile fabric using a simple pad-dry technique. This application method allows the potential manufacture of conductive graphene e-textiles at commercial production rates of ∼150 m/min. The graphene e-textile materials produced are durable and washable with acceptable softness/hand feel. The rGO coating enhanced the tensile strength of cotton fabric and also the flexibility due to the increase in strain% at maximum load. We demonstrate the potential application of these graphene e-textiles for wearable electronics with activity monitoring sensor. This could potentially lead to a multifunctional single graphene e-textile garment that can act both as sensors and flexible heating elements powered by the energy stored in graphene textile supercapacitors.

9.
Materials (Basel) ; 10(8)2017 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-28813014

RESUMO

Manuka honey (MH) is used as an antibacterial agent in bioactive wound dressings via direct impregnation onto a suitable substrate. MH provides unique antibacterial activity when compared with conventional honeys, owing partly to one of its constituents, methylglyoxal (MGO). Aiming to investigate an antibiotic-free antimicrobial strategy, we studied the antibacterial activity of both MH and MGO (at equivalent MGO concentrations) when applied as a physical coating to a nonwoven fabric wound dressing. When physically coated on to a cellulosic hydroentangled nonwoven fabric, it was found that concentrations of 0.0054 mg cm-2 of MGO in the form of MH and MGO were sufficient to achieve a 100 colony forming unit % bacteria reduction against gram-positive Staphylococcus aureus and gram-negative Klebsiella pneumoniae, based on BS EN ISO 20743:2007. A 3- to 20-fold increase in MGO concentration (0.0170-0.1 mg cm-2) was required to facilitate a good antibacterial effect (based on BS EN ISO 20645:2004) in terms of zone of inhibition and lack of growth under the sample. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was also assessed for MGO in liquid form against three prevalent wound and healthcare-associated pathogens, i.e., Staphylococcus aureus, gram-negative Pseudomonas aeruginosa and gram-positive Enterococcus faecalis. Other than the case of MGO-containing fabrics, solutions with much higher MGO concentrations (128 mg L-1-1024 mg L-1) were required to provide either a bacteriostatic or bactericidal effect. The results presented in this study therefore demonstrate the relevance of an MGO-based coating as an environmentally friendly strategy for the design of functional dressings with antibiotic-free antimicrobial chemistries.

10.
Sci Technol Adv Mater ; 18(1): 197-209, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28469734

RESUMO

Healthcare associated infections (HCAIs) are responsible for substantial patient morbidity, mortality and economic cost. Infection control strategies for reducing rates of transmission include the use of nonwoven wipes to remove pathogenic bacteria from frequently touched surfaces. Wiping is a dynamic process that involves physicochemical mechanisms to detach and transfer bacteria to fibre surfaces within the wipe. The purpose of this study was to determine the extent to which systematic changes in fibre surface energy and nano-roughness influence removal of bacteria from an abiotic polymer surface in dry wiping conditions, without liquid detergents or disinfectants. Nonwoven wipe substrates composed of two commonly used fibre types, lyocell (cellulosic) and polypropylene, with different surface energies and nano-roughnesses, were manufactured using pilot-scale nonwoven facilities to produce samples of comparable structure and dimensional properties. The surface energy and nano-roughness of some lyocell substrates were further adjusted by either oxygen (O2) or hexafluoroethane (C2F6) gas plasma treatment. Static adpression wiping of an inoculated surface under dry conditions produced removal efficiencies of between 9.4% and 15.7%, with no significant difference (p < 0.05) in the relative removal efficiencies of Escherichia coli, Staphylococcus aureus or Enterococcus faecalis. However, dynamic wiping markedly increased peak wiping efficiencies to over 50%, with a minimum increase in removal efficiency of 12.5% and a maximum increase in removal efficiency of 37.9% (all significant at p < 0.05) compared with static wiping, depending on fibre type and bacterium. In dry, dynamic wiping conditions, nonwoven wipe substrates with a surface energy closest to that of the contaminated surface produced the highest E. coli removal efficiency, while the associated increase in fibre nano-roughness abrogated this trend with S. aureus and E. faecalis.

11.
Science ; 349(6247): aaa5102, 2015 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-25873744

RESUMO

Knowledge of the magnetization of planetary bodies constrains their origin and evolution, as well as the conditions in the solar nebular at that time. On the basis of magnetic field measurements during the descent and subsequent multiple touchdown of the Rosetta lander Philae on the comet 67P/Churyumov-Gerasimenko (67P), we show that no global magnetic field was detected within the limitations of analysis. The Rosetta Magnetometer and Plasma Monitor (ROMAP) suite of sensors measured an upper magnetic field magnitude of less than 2 nanotesla at the cometary surface at multiple locations, with the upper specific magnetic moment being <3.1 × 10(-5) ampere-square meters per kilogram for meter-size homogeneous magnetized boulders. The maximum dipole moment of 67P is 1.6 × 10(8) ampere-square meters. We conclude that on the meter scale, magnetic alignment in the preplanetary nebula is of minor importance.

12.
Science ; 347(6220): aaa0571, 2015 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-25613894

RESUMO

The Rosetta mission shall accompany comet 67P/Churyumov-Gerasimenko from a heliocentric distance of >3.6 astronomical units through perihelion passage at 1.25 astronomical units, spanning low and maximum activity levels. Initially, the solar wind permeates the thin comet atmosphere formed from sublimation, until the size and plasma pressure of the ionized atmosphere define its boundaries: A magnetosphere is born. Using the Rosetta Plasma Consortium ion composition analyzer, we trace the evolution from the first detection of water ions to when the atmosphere begins repelling the solar wind (~3.3 astronomical units), and we report the spatial structure of this early interaction. The near-comet water population comprises accelerated ions (<800 electron volts), produced upstream of Rosetta, and lower energy locally produced ions; we estimate the fluxes of both ion species and energetic neutral atoms.

13.
J Biomater Appl ; 29(8): 1193-200, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25323605

RESUMO

As problems of antibiotic resistance increase, a continuing need for effective bioactive wound dressings is anticipated for the treatment of infected chronic wounds. Naturally derived antibacterial agents, such as Manuka honey, consist of a mixture of compounds, more than one of which can influence antimicrobial potency. The non-peroxide bacteriostatic properties of Manuka honey have been previously linked to the presence of methylglyoxal. The incorporation of methylglyoxal as a functional antibacterial additive during fibre production was explored as a potential route for manufacturing wound dressing components. Synthetic methylglyoxal and poly(vinyl alcohol) were fabricated into webs of sub-micron fibres by means of electrostatic spinning of an aqueous spinning solution. Composite fabrics were also produced by direct deposition of the poly(vinyl alcohol)-methylglyoxal fibres onto a preformed spunbonded nonwoven substrate. Attenuated total reflectance fourier transform infrared and proton nuclear magnetic resonance spectroscopies confirmed the presence of methylglyoxal within the resulting fibre structure. The antibacterial activity of the fibres was studied using strains of Staphylococcus aureus and Escherichia coli. Strong antibacterial activity, as well as diffusion of methylglyoxal from the fibres was observed at a concentration of 1.55 mg/cm(2).


Assuntos
Antibacterianos/química , Bandagens , Álcool de Polivinil/química , Aldeído Pirúvico/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Escherichia coli/fisiologia , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Teste de Materiais , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade , Staphylococcus aureus/fisiologia , Eletricidade Estática , Têxteis
14.
Chem Cent J ; 6(1): 44, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22616934

RESUMO

BACKGROUND: For millennia, iron-tannate dyes have been used to colour ceremonial and domestic objects shades of black, grey, or brown. Surviving iron-tannate dyed objects are part of our cultural heritage but their existence is threatened by the dye itself which can accelerate oxidation and acid hydrolysis of the substrate. This causes many iron-tannate dyed textiles to discolour and decrease in tensile strength and flexibility at a faster rate than equivalent undyed textiles. The current lack of suitable stabilisation treatments means that many historic iron-tannate dyed objects are rapidly crumbling to dust with the knowledge and value they hold being lost forever.This paper describes the production, characterisation, and validation of model iron-tannate dyed textiles as substitutes for historic iron-tannate dyed textiles in the development of stabilisation treatments. Spectrophotometry, surface pH, tensile testing, SEM-EDX, and XRF have been used to characterise the model textiles. RESULTS: On application to textiles, the model dyes imparted mid to dark blue-grey colouration, an immediate tensile strength loss of the textiles and an increase in surface acidity. The dyes introduced significant quantities of iron into the textiles which was distributed in the exterior and interior of the cotton, abaca, and silk fibres but only in the exterior of the wool fibres. As seen with historic iron-tannate dyed objects, the dyed cotton, abaca, and silk textiles lost tensile strength faster and more significantly than undyed equivalents during accelerated thermal ageing and all of the dyed model textiles, most notably the cotton, discoloured more than the undyed equivalents on ageing. CONCLUSIONS: The abaca, cotton, and silk model textiles are judged to be suitable for use as substitutes for cultural heritage materials in the testing of stabilisation treatments.

15.
Transl Stroke Res ; 2(3): 339-45, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21894249

RESUMO

Cerebral cavernous malformation is a clinically well-defined microvascular disorder predisposing to stroke; however, the major phenotype observed in zebrafish is the cardiac defect, specifically an enlarged heart. Less effort has been made to explore this phenotypic discrepancy between human and zebrafish. Given the fact that the gene products from Ccm1/Ccm2 are nearly identical between the two species, the common sense has dictated that the zebrafish animal model would provide a great opportunity to dissect the detailed molecular function of Ccm1/Ccm2 during angiogenesis. We recently reported on the cellular role of the Ccm1 gene in biochemical processes that permit proper angiogenic microvascular development in the zebrafish model. In the course of this experimentation, we encountered a vast amount of recent research on the relationship between dysfunctional angiogenesis and cardiovascular defects in zebrafish. Here we compile the findings of our research with the most recent contributions in this field and glean conclusions about the effect of defective angiogenesis on the developing cardiovascular system. Our conclusion also serves as a bridge for the phenotypic discrepancy between humans and animal models, which might provide some insights into future translational research on human stroke.

17.
J Magn Magn Mater ; 321(10): 1440-1445, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-20161205

RESUMO

Our goal is to develop an instrument for parallel and multiplexed bioassay using magnetic labels. Toward this end we are developing a multi-outlet magnetophoresis instrument incorporating a fluidic flow chamber placed inside a magnetic field gradient. Magnetic microparticles are sorted by their magnetic moment for eventual use as biological labels based on magnetic signature.In this paper we concentrate on developments in our flow chamber fabrication methods that have allowed us to scale the number of sorting channels from 8 to 25. We present data for instrument performance and reproducibility of sorting.

18.
Aust N Z J Public Health ; 32(3): 224-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18578819

RESUMO

OBJECTIVE: This study investigated the immunisation knowledge, attitudes and practices among health professionals in two regional Area Health Services of NSW with low and high immunisation rates. It also compared these factors between the areas and between the health professional groups. METHODS: A self-administered questionnaire was posted in 2006 to health professionals, located within the North Coast and Hunter New England Area Health Services, whose practice could include immunisation. This included general practitioners (GPs), practice nurses, community nurses, hospital nurses and midwives. RESULTS: Out of 926 surveys sent, 434 were returned (47%). The great majority of the health professionals (97%) believed that vaccines were safe, effective and necessary. However, in approximately one-third of respondents, there were specific concerns about additives, immune system overload and the number of vaccines. Significantly more health professionals in the North Coast area believed that additives in vaccines may be harmful and that adding more vaccines to the schedule would make immunisation too complex. Among GPs, over half felt uncomfortable about giving more than two injections at the one visit. CONCLUSIONS: Health professionals in this study had overall confidence in vaccines but had specific concerns about the number of vaccines given to children and vaccine content. These unfounded concerns may reduce parental confidence in immunisation. IMPLICATIONS: There is value in governments and immunisation support workers continuing their efforts to maintain up-to-date knowledge among health professionals and support the delivery of appropriate and targeted information to address concerns about vaccines.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/psicologia , Programas de Imunização , Pré-Escolar , Humanos , Programas de Imunização/estatística & dados numéricos , Vacina contra Sarampo-Caxumba-Rubéola , Determinação de Necessidades de Cuidados de Saúde , New South Wales , Inquéritos e Questionários
19.
J Oral Maxillofac Surg ; 65(12): 2524-35, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18022480

RESUMO

PURPOSE: To investigate the role of 18-fluorine-fluorodeoxyglucose positron emission tomography/computerized tomography ((18)F-FDG PET/CT) in the preoperative prediction of the presence and extent of neck disease in patients with oral/head and neck cancer. PATIENTS AND METHODS: Seventy patients were enrolled in the study, 47 of whom had a clinically negative neck (N0), 19 of whom had a clinically positive unilateral neck (N+), and 4 of whom were negative on 1 side of the neck and positive on the other. Each patient underwent a PET/CT study before undergoing selective neck dissection for N0 disease or modified radical neck dissection for N+ disease. Tissues were submitted for histopathologic examination and were oriented for the pathologist as to the oncologic levels so as to permit correlation between histopathologic findings and the imaging results. RESULTS: The sensitivity and specificity of the PET/CT procedure were 79% and 82% for the N0 neck, and 95% and 25% for the N+ neck. One hundred ninety-two (11.4%) of the 1,678 nodes identified at histopathology were positive for metastases. The overall nodal sensitivity and specificity were 48% and 99%, respectively. CONCLUSION: In patients with clinically negative necks, a negative test would not help the surgeon in the management strategy of the patient because of the rate of false-negative results, but a positive test can diagnose metastatic deposits with a high positive predictive value. In patients with clinically positive necks, a positive test will confirm the presence of disease, although false-negative lymph nodes were additionally identified in these clinically positive necks. With respect to nodes, the sensitivity of the imaging procedure is such that the results could not help the surgeon in deciding which level to dissect and which to spare. In the final analysis, the head and neck oncologic surgeon should not depend on the results of the PET/CT scan to determine which patients will benefit from neck dissection. Rather, time-honored principles of neck surgery should be followed, particularly with regard to the liberal execution of prophylactic neck dissections in patients with clinically N0 necks.


Assuntos
Carcinoma de Células Escamosas/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Neoplasias Mandibulares/diagnóstico por imagem , Neoplasias Bucais/diagnóstico por imagem , Estadiamento de Neoplasias/métodos , Tomografia por Emissão de Pósitrons/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Reações Falso-Negativas , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Metástase Linfática , Masculino , Neoplasias Mandibulares/patologia , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Esvaziamento Cervical , Estadiamento de Neoplasias/instrumentação , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X , Neoplasias da Língua/diagnóstico por imagem , Neoplasias da Língua/patologia
20.
Cytometry A ; 69(11): 1132-42, 2006 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17051580

RESUMO

BACKGROUND: The goal of our bioassay technique is to demonstrate high throughput, highly parallel, and high sensitivity quantitative molecular analysis that will expand current biomedical research capabilities. To this end, we have built and characterized a magnetophoresis instrument using a flow chamber in a magnetic field gradient to sort magnetic microparticles by their magnetic moment for eventual use as biological labels. METHODS: The flow chamber consists of a sample inlet, differential sheath streams, and eight outlets for collecting the microparticles after they have traversed the chamber. Magnetic microparticles are injected into the flow chamber that is positioned in a linear magnetic field gradient. The trajectory for each microparticle is determined by its total magnetic moment and size. The resulting populations of monodispersed magnetic microparticles in the different outlet bins are sorted by their magnetic moment; with the highest magnetic moments being deflected the furthest. RESULTS: We have characterized the system for sorting both superparamagnetic and ferromagnetic microparticles with approximate diameters of 8 microm and 4.0-4.9 microm, respectively. To characterize the instrument, we used microparticles with a known size distribution and varied the transit time through the chamber. This is equivalent to varying the magnetic moment, while allowing us to hold the particle properties constant from run-to-run. We demonstrated the ability to reproducibly change the distribution of the particles in the collection bins by varying transit time in good agreement with theory. We identified hydrodynamic instabilities responsible for causing dispersion in the flow. Improvements to the flow chamber hydrodynamics such as reducing the aspect ratio between the sample inlet and the chamber depth and stabilizing the sheath flow resulted in narrow sorting distributions. We measured a sorting reproducibility (percentage of particles returning to their original bin upon resorting individual populations) of 84-89%. CONCLUSIONS: We have developed a simple magnetophoresis system for reproducibly sorting magnetic microparticles. This technique will permit the use of microparticles with a wide range of magnetic moments to create a wide range of magnetic labels. Careful consideration of system design and operational parameters enables reliable and reproducible sorting of microparticles with varying size and magnetic content.


Assuntos
Bioensaio/instrumentação , Campos Eletromagnéticos , Magnetismo/instrumentação , Tamanho da Partícula , Bioensaio/métodos , Desenho de Equipamento , Matemática , Coloração e Rotulagem/métodos
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