Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 265
Filtrar
1.
Int J Tuberc Lung Dis ; 26(9): 875-879, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35996278

RESUMO

BACKGROUND: Xpert® MTB/RIF, a rapid, molecular TB diagnostic assay, can detect Mycobacterium tuberculosis and rifampin resistance directly from clinical sputum samples in <2 h with high sensitivity and specificity. The added diagnostic value of Xpert over smear microscopy at a national level in Myanmar has not been previously reported.METHODS: We evaluated 339,358 Xpert and demographic records captured from January 2015 to December 2018 as part of the Myanmar National TB Program Data Utilization and Connectivity Project to examine the additional diagnostic yield of Xpert relative to smear for the detection of M. tuberculosis for TB diagnosis in Myanmar, with a focus on people living with HIV (PLHIV) and sample type.RESULTS: Use of Xpert increased TB case detection by 40% compared to smear microscopy results. Among PLHIV, use of Xpert increased TB case detection by almost 100% compared to smear microscopy results.CONCLUSION: Xpert testing identified more patients with TB than smear microscopy alone, particularly in cohorts with significant proportions of PLHIV. The use of Xpert as a screening tool in countries with a high burden of TB could lead to significantly increased diagnosis of TB at a regional and national level.


Assuntos
Farmacorresistência Bacteriana , Mycobacterium tuberculosis , Tuberculose , Humanos , Mianmar/epidemiologia , Mycobacterium tuberculosis/genética , Rifampina/farmacologia , Rifampina/uso terapêutico , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/diagnóstico
2.
J Nanobiotechnology ; 19(1): 83, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33766057

RESUMO

BACKGROUND: Chemokine therapy with C-C motif chemokine ligand 25 (CCL25) is currently under investigation as a promising approach to treat articular cartilage degeneration. We developed a delayed release mechanism based on Poly (lactic-co-glycolic acid) (PLGA) microparticle encapsulation for intraarticular injections to ensure prolonged release of therapeutic dosages. However, CCL25 plays an important role in immune cell regulation and inflammatory processes like T-cell homing and chronic tissue inflammation. Therefore, the potential of CCL25 to activate immune cells must be assessed more thoroughly before further translation into clinical practice. The aim of this study was to evaluate the reaction of different immune cell subsets upon stimulation with different dosages of CCL25 in comparison to CCL25 released from PLGA particles. RESULTS: Immune cell subsets were treated for up to 5 days with CCL25 and subsequently analyzed regarding their cytokine secretion, surface marker expression, polarization, and migratory behavior. The CCL25 receptor C-C chemokine receptor type 9 (CCR9) was expressed to a different extent on all immune cell subsets. Direct stimulation of peripheral blood mononuclear cells (PBMCs) with high dosages of CCL25 resulted in strong increases in the secretion of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), interleukin-1ß (IL-1ß), tumor-necrosis-factor-α (TNF-α) and interferon-γ (IFN-γ), upregulation of human leukocyte antigen-DR (HLA-DR) on monocytes and CD4+ T-cells, as well as immune cell migration along a CCL25 gradient. Immune cell stimulation with the supernatants from CCL25 loaded PLGA microparticles caused moderate increases in MCP-1, IL-8, and IL-1ß levels, but no changes in surface marker expression or migration. Both CCL25-loaded and unloaded PLGA microparticles induced an increase in IL-8 and MCP-1 release in PBMCs and macrophages, and a slight shift of the surface marker profile towards the direction of M2-macrophage polarization. CONCLUSIONS: While supernatants of CCL25 loaded PLGA microparticles did not provoke strong inflammatory reactions, direct stimulation with CCL25 shows the critical potential to induce global inflammatory activation of human leukocytes at certain concentrations. These findings underline the importance of a safe and reliable release system in a therapeutic setup. Failure of the delivery system could result in strong local and systemic inflammatory reactions that could potentially negate the benefits of chemokine therapy.


Assuntos
Quimiocinas CC/farmacologia , Quimiocinas CC/uso terapêutico , Preparações de Ação Retardada/farmacologia , Preparações de Ação Retardada/uso terapêutico , Inflamação/tratamento farmacológico , Quimiocina CCL2/metabolismo , Quimiocinas/farmacologia , Quimiocinas/uso terapêutico , Humanos , Interferon gama , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , Leucócitos Mononucleares , Ligantes , Macrófagos/metabolismo , Monócitos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Receptores CCR/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
3.
Semin Cell Dev Biol ; 106: 106-115, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32295724

RESUMO

The Avian retina is far less known than that of mammals such as mouse and macaque, and detailed study is overdue. The chicken (Gallus gallus) has potential as a model, in part because research can build on developmental studies of the eye and nervous system. One can expect differences between bird and mammal retinas simply because whereas most mammals have three types of visual photoreceptor birds normally have six. Spectral pathways and colour vision are of particular interest, because filtering by oil droplets narrows cone spectral sensitivities and birds are probably tetrachromatic. The number of receptor inputs is reflected in the retinal circuitry. The chicken probably has four types of horizontal cell, there are at least 11 types of bipolar cell, often with bi- or tri-stratified axon terminals, and there is a high density of ganglion cells, which make complex connections in the inner plexiform layer. In addition, there is likely to be retinal specialisation, for example chicken photoreceptors and ganglion cells have separate peaks of cell density in the central and dorsal retina, which probably serve different types of behaviour.


Assuntos
Visão Ocular/fisiologia , Animais , Galinhas
4.
J Hosp Infect ; 105(2): 252-257, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32112827

RESUMO

BACKGROUND: Heater-cooler units (HCUs) have been implicated in the recent global outbreak of invasive Mycobacterium chimaera infection among patients following cardiothoracic surgery. Because infected patients tend to remain asymptomatic for extended periods, detection of M. chimaera from HCUs in real time is essential to halting the ongoing M. chimaera HCU-associated outbreak. Sample collection protocols to evaluate the presence of M. chimaera offer conflicting recommendations regarding the addition of sodium thiosulfate (NaT) during the collection process. AIM: To study the effect of NaT on M. chimaera recovery and culture contamination. METHODS: Seventy-six paired HCU water samples (with and without NaT) were collected, processed and cultured simultaneously into Lowenstein-Jensen slants, Middlebrook 7H10 agar plates, and mycobacterial growth indicator tubes (MGITs), and incubated at 37°C. A subset of 31 paired samples was additionally cultured on MGITs and incubated at 30°C. FINDINGS: Of 76 samples incubated at 37°C in each of the three media, with and without NaT, M. chimaera was identified in at least one aliquot of 21 samples. CONCLUSION: The presence of NaT did not significantly increase the probability of recovering M. chimaera in a multi-variable conditional logistic model and culture contamination rates were similar between aliquots with and without NaT. In the subset of samples cultured on MGITs at both 30°C and 37°C, the presence of NaT again was not associated with M. chimaera recovery, but was significantly associated with reduced culture contamination.


Assuntos
Contaminação de Equipamentos , Infecções por Mycobacterium/prevenção & controle , Mycobacterium/efeitos dos fármacos , Tiossulfatos/farmacologia , Microbiologia da Água , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Contagem de Colônia Microbiana , Surtos de Doenças/prevenção & controle , Calefação/instrumentação , Humanos , Mycobacterium/isolamento & purificação , Viés de Seleção , Água , Abastecimento de Água
5.
Eur Cell Mater ; 38: 188-200, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31612460

RESUMO

High glucose concentrations have been shown to activate endothelial cells and promote angiogenesis. In the present study, it was investigated whether high glucose concentrations could improve the vascularisation capacity of adipose-tissue-derived microvascular fragments (ad-MVF). Ad-MVF were isolated from the epididymal fat pads of donor mice and cultivated for 24 h in University of Wisconsin (UW) solution supplemented with vehicle or 30 mM glucose. Protein expression, morphology, viability and proliferation of the cultivated ad-MVF were analysed by means of proteome profiler mouse angiogenesis array, scanning electron microscopy and immunohistochemistry. Additional cultivated ad-MVF were seeded on to collagen-glycosaminoglycan scaffolds to study their in vivo vascularisation capacity in the dorsal skinfold chamber model by intravital fluorescence microscopy, histology and immunohistochemistry. In vitro, high glucose exposure changed the protein expression pattern of ad-MVF with endoglin, interleukin (IL)-1ß and monocyte chemoattractant protein (MCP)-1 as the most up-regulated pro-angiogenic factors. Moreover, high glucose exposure induced the formation of nanopores in the ad-MVF wall. In addition, ad-MVF contained significantly larger numbers of proliferating endothelial and perivascular cells while exhibiting a comparable number of apoptotic cells when compared to vehicle-treated controls. In vivo, scaffolds seeded with high-glucose-exposed ad-MVF exhibited an improved vascularisation and tissue incorporation. These findings demonstrated that the exposure of cultivated ad-MVF to high glucose concentrations is a promising approach to improve their in vivo performance as vascularisation units for tissue engineering and regenerative medicine.


Assuntos
Tecido Adiposo/citologia , Proliferação de Células , Glucose/farmacologia , Microvasos/citologia , Neovascularização Fisiológica , Engenharia Tecidual/métodos , Animais , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Endoglina/genética , Endoglina/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Proteoma/genética , Proteoma/metabolismo
6.
J Food Sci ; 84(10): 2955-2960, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31509251

RESUMO

This study aimed to identify consumers' preferences and impressions of minimally processed "Gala" cultivar apples, using preference tests and word associations. The study was conducted online via the Google Docs tool and sent out via social networks. The participants were 607 individuals, mostly women, mainly between the ages of 18 and 45, with education up to undergraduate and postgraduate level. As regards the preference for minimally processed apples, the profile of the consumer did not influence the choice. The profiles analyzed were gender and education. For the word association test, 11-word categories were formed, and among these, the most important aspect was appearance, followed by taste and texture, which was confirmed by correspondence analysis. Sample A (0 days-no storage) was the most preferred one, differing significantly from the other samples, whereas sample B (3 days of storage) and sample C (6 days of storage) were associated with characteristics for choice of product. The word association methodology revealed the consumer's impressions of the product, in addition to demonstrating simplicity, low cost, speed, and an exploratory character. PRACTICAL APPLICATION: Gender and level of schooling did not influence the choice of minimally processed apples. Appearance was the most cited word in the word association test. Word association is a simple, fast, inexpensive, and projective technique.


Assuntos
Comportamento do Consumidor , Malus/química , Adolescente , Adulto , Comportamento de Escolha , Feminino , Manipulação de Alimentos , Frutas/química , Humanos , Masculino , Pessoa de Meia-Idade , Paladar , Adulto Jovem
7.
Breast ; 46: 101-107, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31132475

RESUMO

BACKGROUND: To evaluate whether uPA/PAI-1 protein in hormone receptor-positive (HR+) breast tumor can predict prognosis in early breast cancer (BC). METHODS: 606 women with HR + BC who had ≥5 years of endocrine therapy and in whom tumor tissue was available were included in this analysis. Stromal uPA/PAI-1 protein expression was evaluated by immunohistochemistry and correlated with distant recurrence-free survival (DRFS) and overall survival (OS). RESULTS: Stromal uPA was detected in 292/538 tumors (54.3%) while 269/505 samples (53.3%) exhibited stromal PAI-1. Co-expression of both proteins was found in 163/437 (37.3%) samples. Stromal uPA/PAI-1 co-expression was not associated with tumor size, age, nodal status, grading, or receptor status. Tumor stroma with both uPA and PAI-1 protein expression were more likely to have a shorter DRFS (HR: 1.87; 95%CI 1.18-2.96; p = 0.007) and OS (HR: 1.29; 95%CI 0.93-1.80; p = 0.129) than women without uPA/PAI-1 co-expression. After a median follow-up of 10 years, women with uPA/PAI-1-positive tumors experienced a significantly shorter DRFS (86.5% vs 72.4%; p < 0.001) and OS (70.4% vs 58.9%; p = 0.020) compared to women with uPA/PAI-1 negative tumors. CONCLUSION: Stromal co-expression of uPA and PAI-1 in breast cancer predicts poor DRFS and OS in postmenopausal women with HR + early-stage BC who receive endocrine therapy.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Mama/citologia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Idoso , Antineoplásicos Hormonais/uso terapêutico , Biomarcadores Tumorais/genética , Neoplasias da Mama/tratamento farmacológico , Intervalo Livre de Doença , Receptores ErbB/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Pós-Menopausa , Prognóstico , Fatores de Risco , Células Estromais/metabolismo , Resultado do Tratamento
8.
Herzschrittmacherther Elektrophysiol ; 30(2): 197-203, 2019 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-30969355

RESUMO

Infective endocarditis (IE) as well as septicemia in patients with implanted cardiac devices are severe diseases and diagnosis is often delayed due to a variety of misleading symptoms. Imaging with transesophageal echocardiography (TEE) and also microbiology play a key role in both the diagnosis and management. They are also useful for the prognostic assessment of patients with IE, for follow-up during treatment, during extraction of the implant and after surgery. In addition to antibiotic treatment, removal of the implant is also necessary, at least if vegetation is detected. Not only the removal of the implant but also the underlying cardiac disease, the frequently occurring severe cardiac insufficiency, the advanced age and the not uncommon high degree of fragility of the patients mean that decision making for treatment and management as well as renewed implantation after completion of treatment are a challenge. The optimal treatment is only possible with a close cooperation between various specialist disciplines and should therefore be carried out in experienced centers.


Assuntos
Endocardite Bacteriana , Sepse , Ecocardiografia Transesofagiana , Humanos , Instrumentos Cirúrgicos
9.
Gesundheitswesen ; 81(1): 63-71, 2019 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-27846670

RESUMO

BACKGROUND: Health care needs of mentally ill patients make special demands on cross-sectoral health care structures. § 64b SGB V enables care of mentally ill patients through model projects that are multi-professional, work across treatment periods and sectors and implement new forms of financing. These model projects in their hospitals (case hospitals) need to be evaluated and compared with standard treatment methods. OBJECTIVES: The aim of this analysis is to identify matching hospitals according to a priori defined criteria for the establishment of a control group (control hospitals) using secondary data. MATERIALS AND METHODS: A systematic analysis was conducted based on structured quality reports according to §+137 SGB V and matched data from the Federal Institute for Research on Building, Urban Affairs and Spatial Development (BBSR). Based on a priori defined knock-out criteria, criteria based on patients (weighting 50%), structural features of hospitals (25%) and environmental factors (25%), a weighted similarity score was calculated for each of the 13 case hospitals, which could reach the maximum of 100 points (perfect match). RESULTS: 10 control hospitals per case hospital were identified according to the weighted similarity score. The median of the total deviation of potential control hospitals from the case hospitals was 34.3 (range: 17.6-66.7). The median of the 10 selected control hospitals per case hospital was 30.9 (range: 17.6-40.8). DISCUSSION: The defined algorithm could be used to identify similar control hospitals. The method using the mentioned databases and derivation of specific criteria of structural similarity are generally suitable in controlled designs for the evaluation of complex interventions based on routine data.


Assuntos
Atenção à Saúde , Necessidades e Demandas de Serviços de Saúde , Hospitais , Transtornos Mentais , Bases de Dados Factuais , Alemanha , Humanos , Transtornos Mentais/terapia
10.
Herzschrittmacherther Elektrophysiol ; 29(4): 340-348, 2018 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-30406825

RESUMO

There are still several limitations in delivering cardiac resynchronisation therapy (CRT). After 6 months, 20-40% of patients fail to have clinical benefit due to various reasons. Endocardial stimulation rather than conventional epicardial pacing has been shown to be more physiological, improves electrical stimulation of the left ventricle (LV), has less dispersion of electrical activity and results in better resynchronisation. The WiSE™ CRT System ("Wireless stimulation endocardial system"; EBR Systems, Sunnyvale, CA, USA) provides an option for wireless, LV endocardial pacing triggered by a conventional right ventricular pacing spike from a co-implant. The feasibility of the WiSE™ CRT System has been successfully demonstrated in a population of failed cardiac resynchronisation patients with either failed implantation of a conventional system, nonresponse to conventional therapy or upgrade from pacemaker or defibrillator, where a conventional system was not an option. The WiSE™ CRT System is an innovative technology with promising safety, performance and preliminary efficacy.


Assuntos
Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca , Marca-Passo Artificial , Endocárdio , Ventrículos do Coração , Humanos , Resultado do Tratamento
11.
J Phys D Appl Phys ; 51(21)2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-30416209

RESUMO

Emperor penguins (Aptenodytes forsteri) are highly adapted to the harsh conditions of the Antarctic winter: they are able to fast for up to 134 days during breeding. To conserve energy, emperor penguins form tight groups (huddles), which is key for their reproductive success. The effect of different meteorological factors on the huddling behaviour, however, is not well understood. Using time-lapse image recordings of an emperor penguin colony, we show that huddling can be described as a phase transition from a fluid to a solid state. We use the colony density as order parameter, and an apparent temperature that is perceived by the penguins as the thermodynamic variable. We approximate the apparent temperature as a linear combination of four meteorological parameters: ambient temperature, wind speed, global radiation and relative humidity. We find a wind chill factor of -2.9 °C/(ms -1), a humidity chill factor of -0.5°C/% rel. humidity, and a solar radiation heating factor of 0.3 °C//(Wm 2). In the absence of wind, humidity and solar radiation, the phase transition temperature (50% huddling probability) is -48.2°C for the investigated time period (May 2014). We propose that higher phase transition temperatures indicate a shrinking thermal insulation and thus can serve as a proxy for lower energy reserves of the colony, integrating pre-breeding foraging success at sea and energy expenditure at land due to environmental conditions. As current global change is predicted to have strong detrimental effects on emperor penguins within the next decades, our approach may thus contribute towards an urgently needed long-term monitoring system for assessing colony health.

12.
J R Soc Interface ; 14(136)2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29118112

RESUMO

Adult gliomas are aggressive brain tumours associated with low patient survival rates and limited life expectancy. The most important hallmark of this type of tumour is its invasive behaviour, characterized by a markedly phenotypic plasticity, infiltrative tumour morphologies and the ability of malignant progression from low- to high-grade tumour types. Indeed, the widespread infiltration of healthy brain tissue by glioma cells is largely responsible for poor prognosis and the difficulty of finding curative therapies. Meanwhile, mathematical models have been established to analyse potential mechanisms of glioma invasion. In this review, we start with a brief introduction to current biological knowledge about glioma invasion, and then critically review and highlight future challenges for mathematical models of glioma invasion.


Assuntos
Neoplasias Encefálicas , Encéfalo , Glioma , Modelos Biológicos , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/fisiopatologia , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Glioma/metabolismo , Glioma/patologia , Glioma/fisiopatologia , Humanos , Invasividade Neoplásica
13.
Phys Med Biol ; 62(16): 6729-6745, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28762340

RESUMO

We report on a radiographic measurement of an ex vivo human knee using a grating-based phase-contrast imaging setup and a medical x-ray tube at a tube voltage of 70 kV. The measurement has been carried out using a Talbot-Lau setup that is suitable to achieve a high visibility in the energy regime of medical imaging. In a medical reading by an experienced trauma surgeon signatures of chondrocalcinosis in the medial meniscus have been identified more evidently using the dark-field image in comparison to the conventional attenuation image. The analysis has been carried out at various dose levels down to 0.14 mGy measured as air kerma, which is a dose comparable to clinically used radiographic devices. The diagnosis has been confirmed by a histological analysis of the meniscus tissue. In the introduced high-frequency filtered phase-contrast image the anterior and posterior horn of the medial meniscus and the posterior cruciate ligament have also been visible. Furthermore, atherosclerotic plaque is visible in both imaging modalities, attenuation and dark-field, despite the presence of overlaying bone. This measurement, for the first time, proves the feasibility of Talbot-Lau x-ray imaging at high-energy spectra above 40 kVp and reasonable dose levels with regard to spacious and dense objects.


Assuntos
Joelho/diagnóstico por imagem , Radiografia/métodos , Estudos de Viabilidade , Humanos , Doses de Radiação
15.
Leukemia ; 30(12): 2283-2292, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27499139

RESUMO

A key feature of the adaptive immune system is the generation of memory B and T cells and long-lived plasma cells, providing protective immunity against recurring infectious agents. Memory B cells are generated in germinal center (GC) reactions in the course of T cell-dependent immune responses and are distinguished from naive B cells by an increased lifespan, faster and stronger response to stimulation and expression of somatically mutated and affinity matured immunoglobulin (Ig) genes. Approximately 40% of human B cells in adults are memory B cells, and several subsets were identified. Besides IgG+ and IgA+ memory B cells, ∼50% of peripheral blood memory B cells express IgM with or without IgD. Further smaller subpopulations have additionally been described. These various subsets share typical memory B cell features, but likely also fulfill distinct functions. IgM memory B cells appear to have the propensity for refined adaptation upon restimulation in additional GC reactions, whereas reactivated IgG B cells rather differentiate directly into plasma cells. The human memory B-cell pool is characterized by (sometimes amazingly large) clonal expansions, often showing extensive intraclonal IgV gene diversity. Moreover, memory B-cell clones are frequently composed of members of various subsets, showing that from a single GC B-cell clone a variety of memory B cells with distinct functions is generated. Thus, the human memory B-cell compartment is highly diverse and flexible. Several B-cell malignancies display features suggesting a derivation from memory B cells. This includes a subset of chronic lymphocytic leukemia, hairy cell leukemia and marginal zone lymphomas. The exposure of memory B cells to oncogenic events during their generation in the GC, the longevity of these B cells and the ease to activate them may be key determinants for their malignant transformation.


Assuntos
Linfócitos B/imunologia , Memória Imunológica , Linfócitos B/classificação , Linfócitos B/citologia , Humanos , Isotipos de Imunoglobulinas , Neoplasias/patologia
16.
Phys Med Biol ; 61(17): 6441-64, 2016 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-27514576

RESUMO

X-ray grating-based phase-contrast imaging opens new opportunities, inter alia, in medical imaging and non-destructive testing. Because, information about the attenuation properties and about the refractive properties of an object are gained simultaneously. Talbot-Lau imaging requires the knowledge of a reference or free-field image. The long-term stability of a Talbot-Lau interferometer is related to the time span of the validity of a measured reference image. It would be desirable to keep the validity of the reference image for a day or longer to improve feasibility of Talbot-Lau imaging. However, for example thermal and other long-term external influences result in drifting effects of the phase images. Therefore, phases are shifting over time and the reference image is not valid for long-term measurements. Thus, artifacts occur in differential phase-contrast images. We developed an algorithm to determine the differential phase-contrast image with the help of just one calibration image, which is valid for a long time-period. With the help of this algorithm, called phase-plane-fit method, it is possible to save measurement-time, as it is not necessary to take a reference image for each measurement. Additionally, transferring the interferometer technique from laboratory setups to conventional imaging systems the necessary rigidity of the system is difficult to achieve. Therefore, short-term effects like vibrations or distortions of the system lead to imperfections within the phase-stepping procedure. Consequently, artifacts occur in all three image modalities (differential phase-contrast image, attenuation image and dark-field image) of Talbot-Lau imaging. This is a problem with regard to the intended use of phase-contrast imaging for example in clinical routine or non-destructive testing. In this publication an algorithm of Vargas et al is applied and complemented to correct inaccurate phase-step positions with the help of a principal component analysis (PCA). Thus, it is possible to calculate the artifact free images. Subsequently, the whole algorithm is called PCA minimization algorithm.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador/métodos , Imagem Óptica/métodos , Tomografia Computadorizada por Raios X/métodos , Artefatos , Humanos , Processamento de Imagem Assistida por Computador/normas , Interferometria/instrumentação , Interferometria/métodos
17.
Expert Rev Med Devices ; 13(6): 523-31, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27157452

RESUMO

INTRODUCTION: There are several unsolved limitations in delivering cardiac resynchronization therapy. 30-40% of patients fail to have any clinical benefit after 6 months caused by different reasons. AREAS COVERED: Endocardial stimulation rather than conventional epicardial pacing has been shown to: be more physiologically, improve electrical stimulation of the left ventricular, give less dispersion of repolarisation and result in better resynchronization. The Wireless Cardiac Stimulation in Left Ventricle, WiCS-LV, system provides an option for wireless, left ventricular endocardial pacing triggered from a conventional right ventricular pacing spike from a co-implant. Expert commentary: The feasibility of the WiCS-LV system has been successfully demonstrated in a population of failed cardiac resynchronization patients, either failed implantation procedure of a conventional system, non-responder to conventional therapy or upgrade from pacemaker or defibrillator, where a conventional system was not an option. WiCS-LV is innovative technology with promising safety, performance and preliminary efficacy.


Assuntos
Dispositivos de Terapia de Ressincronização Cardíaca , Terapia de Ressincronização Cardíaca/métodos , Endocárdio/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Tecnologia sem Fio/instrumentação , Humanos
18.
Int J Tuberc Lung Dis ; 20(5): 631-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27084817

RESUMO

OBJECTIVE: To evaluate the performance of a recently updated rapid molecular diagnostic test, GenoType® MTBDRplus version 2, designed to detect drug resistance in both acid-fast bacilli (AFB) smear-negative and -positive specimens. DESIGN: Sputum samples from 1128 patients at risk for multidrug-resistant tuberculosis (MDR-TB) were tested using MTBDRplus v2 and compared with reference standard MGIT™ 960™ drug susceptibility testing. The relationship of participant human immunodeficiency virus (HIV) status, diabetic status, previous treatment, and smear gradation to the likelihood of obtaining an interpretable result was assessed using logistic regression. RESULTS: The sensitivity and specificity of MTBDRplus v2 for detecting MDR-TB, when compared to a reference standard, were respectively 96.0% (95%CI 93.5-97.6) and 99.2% (95%CI 97.0-99.9) in AFB smear-positive specimens and 82.8% (95%CI 63.5-93.5) and 98.3% (95%CI 89.9-99.9) in AFB smear-negative specimens. A dose-response relationship was observed between the proportion of interpretable test results and AFB smear bacterial load after adjusting for age, sex, body mass index, HIV status, previous treatment and diabetic status. CONCLUSION: While MTBDRplus v2 performs well among both AFB smear-positive and -negative specimens, smear gradation appears to influence both the probability of obtaining an interpretable result and test sensitivity, indicating a significant association between bacillary load and test performance.


Assuntos
Técnicas Bacteriológicas , DNA Bacteriano/genética , Farmacorresistência Bacteriana Múltipla/genética , Pulmão/microbiologia , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis/genética , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Pulmonar/diagnóstico , Adulto , Carga Bacteriana , Técnicas Bacteriológicas/normas , Calibragem , DNA Bacteriano/isolamento & purificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/normas , Mycobacterium tuberculosis/isolamento & purificação , Valor Preditivo dos Testes , Estudos Prospectivos , Padrões de Referência , Reprodutibilidade dos Testes , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Pulmonar/microbiologia , Adulto Jovem
19.
Antimicrob Agents Chemother ; 60(7): 3994-4004, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27090176

RESUMO

Molecular diagnostic assays, with their ability to rapidly detect resistance-associated mutations in bacterial genes, are promising technologies to control the spread of drug-resistant tuberculosis (DR-TB). Sequencing assays provide detailed information for specific gene regions and can help diagnostic assay developers prioritize mutations for inclusion in their assays. We performed pyrosequencing of seven Mycobacterium tuberculosis gene regions (katG, inhA, ahpC, rpoB, gyrA, rrs, and eis) for 1,128 clinical specimens from India, Moldova, and South Africa. We determined the frequencies of each mutation among drug-resistant and -susceptible specimens based on phenotypic drug susceptibility testing results and examined mutation distributions by country. The most common mutation among isoniazid-resistant (INH(r)) specimens was the katG 315ACC mutation (87%). However, in the Eastern Cape, INH(r) specimens had a lower frequency of katG mutations (44%) and higher frequencies of inhA (47%) and ahpC (10%) promoter mutations. The most common mutation among rifampin-resistant (RIF(r)) specimens was the rpoB 531TTG mutation (80%). The mutation was common in RIF(r) specimens in Mumbai (83%) and Moldova (84%) but not the Eastern Cape (17%), where the 516GTC mutation appeared more frequently (57%). The most common mutation among fluoroquinolone-resistant specimens was the gyrA 94GGC mutation (44%). The rrs 1401G mutation was found in 84%, 84%, and 50% of amikacin-resistant, capreomycin-resistant, and kanamycin (KAN)-resistant (KAN(r)) specimens, respectively. The eis promoter mutation -12T was found in 26% of KAN(r) and 4% of KAN-susceptible (KAN(s)) specimens. Inclusion of the ahpC and eis promoter gene regions was critical for optimal test sensitivity for the detection of INH resistance in the Eastern Cape and KAN resistance in Moldova. (This study has been registered at ClinicalTrials.gov under registration number NCT02170441.).


Assuntos
Tuberculose Resistente a Múltiplos Medicamentos/genética , Proteínas de Bactérias/genética , Capreomicina/uso terapêutico , Farmacorresistência Bacteriana Múltipla/genética , Isoniazida/uso terapêutico , Canamicina/uso terapêutico , Testes de Sensibilidade Microbiana , Moldávia , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Rifampina/uso terapêutico , África do Sul , Tuberculose , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
20.
Int J Cosmet Sci ; 38(3): 232-7, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26383131

RESUMO

OBJECTIVE: Cosmetic formulations are influenced by environmental impacts and ageing, resulting in rancidity and change of colour and structure. These changes are caused by free radicals (FRs). The sensitivity of cosmetics generating FRs is a metric for its quality and should be determined. METHODS: Electron spin resonance spectroscopy in combination with UV irradiation tested cosmetics such as creams, milks, lotions and fragrances. The probes were directly measured without expensive preparation. RESULTS: Nine formulations are tested for its radical generation and ranked corresponding to the radical power. The transformation of the FR properties of three formulations to skin is measured by the radical skin status factor (RSF) method. It shows that the higher the radical power (RP) is, the lower the radical status RSF of skin will be. CONCLUSION: The knowledge of the sensitivity of cosmetics to generate FRs is necessary for its stabilization and prevention of potential damages to skin. It is a new way in development of cosmetics which has to be considered.


Assuntos
Cosméticos , Espectroscopia de Ressonância de Spin Eletrônica , Técnicas In Vitro
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...