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1.
Am J Occup Ther ; 78(4)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38848284

RESUMO

IMPORTANCE: Parent recall is the primary method for measuring positioning practices such as tummy time in infants. Concerns regarding the accuracy of parent recall have been raised in the literature. To date, no study has examined the agreement of tummy time recall measures with gold-standard methods. OBJECTIVE: To assess the agreement between parental recall versus direct observation of tummy time in infants, and to explore the impact of prematurity on this relationship. DESIGN: Cross-sectional observational study, spanning 1 yr. SETTING: Participants' homes Participants: Thirty-two infant-parent dyads (19 full-term, 13 preterm), with infants ages 3 to 6 mo and caregivers ages older than 18 yr. OUTCOME AND MEASURES: Home-recorded videos of infant play across 3 days were used as a proxy for direct observation of tummy time and compared with a 12-item parent recall survey. RESULTS: Parent recall had a significant moderate correlation (ρ = .54, p = .002) with direct observation in full-term infants but was not correlated (p = .23) with direct observation in preterm infants. On average, parents of preterm infants overestimated tummy time by 2.5 times per day compared with direct observation. CONCLUSIONS AND RELEVANCE: For full-term infants, parent recall measures of tummy time exhibit an acceptable level of agreement with direct observation and can be reliably used over shorter periods. Parents of preterm infants may display a bias in recalling tummy time, leading to overestimations. To accurately assess tummy time in this population, a combination of subjective and objective measures should be explored. Plain-Language Summary: Tummy time is an essential movement experience for infants, especially for preterm infants, who are at a higher risk for motor delays. The most common way to track tummy time is through parent reports, or recall, versus a practitioner directly observing tummy time in the home. Despite the widespread use of parent recall to track tummy time, no study has examined the accuracy of parent recall versus direct observation in the home. Accurately assessing tummy time is crucial for improving and supporting health outcomes for infants. This study found that prematurity may affect the accuracy of parent recall for assessing tummy time in young infants. The authors discuss the implications of this finding and provide suggestions to guide the selection of appropriate methods to measure tummy time in clinical practice and research studies.


Assuntos
Recém-Nascido Prematuro , Rememoração Mental , Pais , Humanos , Estudos Transversais , Feminino , Lactente , Masculino , Recém-Nascido , Adulto , Observação , Fatores de Tempo
2.
Analyst ; 147(3): 480-488, 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35023516

RESUMO

Inflammatory bowel disease (IBD) is a term used to describe disorders that involve chronic inflammation in the gastrointestinal tract, affecting more than 6.8 million people worldwide. Biological therapy is used in the most severe cases of IBD where anti-tumour necrosis factor-alpha (TNF-α) antibodies are the first choice for a biological treatment. When administrated to patients, these antibodies interact with TNF-α, usually overexpressed in these diseases, neutralizing its biological activity. Because of the chronic nature of these diseases, a recurring administration of the therapeutic antibodies is required, thus making therapy monitorization essential for the correct management of these diseases. The aim of this work is the development of an enzyme-linked immunosorbent assay (ELISA) microfluidic biosensor to quantify the therapeutic antibodies in IBD patient plasma samples, where the commercial monoclonal antibody Infliximab (IFX) is used as a model target. By providing a faster and more accurate measurement of IFX, the proposed method leads to improved therapy scheduling and a reduced risk of endogenous anti-drug antibodies (ADAs) reducing the efficacy of the treatment. The time needed between sample insertion and result output for the microfluidic ELISA (mELISA) is 24 minutes, drastically shorter than the time required by the conventional ELISA (cELISA). The mELISA presented in this work has a LoD of 0.026 µg mL-1, while commercially available solutions provide a LoD of 0.15 µg mL-1. Results acquired by the mELISA are highly correlated with the results obtained from the cELISA (r = 0.998; R2 = 0.996; p < 0.0001), demonstrating the validity of the microfluidic approach for the quantification of IFX from patient plasma and its potential for use at the point-of-care (POC).


Assuntos
Doenças Inflamatórias Intestinais , Microfluídica , Anticorpos Monoclonais , Monitoramento de Medicamentos , Ensaio de Imunoadsorção Enzimática , Humanos , Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab , Fator de Necrose Tumoral alfa
3.
Dev Psychobiol ; 64(8): e22334, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36426787

RESUMO

Thirty-two children (50% female, 59.3% White, 7-60 months), from middle to high socioeconomic status families, participated in pilot feasibility and validity testing of the somatosensory test of reaching (STOR). STOR tested the child's accuracy of reach to visual and somatosensory targets. All children were able to complete the assessment. Statistically significant differences were found between age groups (p = .0001), showing developmental trends, and between test conditions (p < .001), showing that the ability to reach to visible targets develops before somatosensory targets. STOR also showed a moderate correlation with the Developmental Assessment of Young Children 2nd edition. STOR appears to be a promising tool for assessing somatosensory processing in very young children, and it warrants additional testing in larger participant samples.


Assuntos
Distúrbios Somatossensoriais , Pré-Escolar , Feminino , Humanos , Masculino , Lactente , Distúrbios Somatossensoriais/diagnóstico
4.
Analyst ; 145(24): 7973-7984, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33043921

RESUMO

Early diagnosis of fungal infections, which have seen an increase due to different environmental factors, is essential to an appropriate treatment of the plant by avoiding proliferation of the pathogen without excessive fungicide applications. In this work, we propose a microfluidic based approach to a multiplexed, point-of-need detection system capable of identifying infected grape cultivars. The system relies on the simultaneous detection of three plant hormones: salicylic, azelaic and jasmonic acids with a total assay time under 7 minutes, with LODs of 15 µM, 10 µM and 4.4 nM respectively. The three detection assays are based on optical transduction, with the detection of salicylic and azelaic acids using transmission measurements, while the detection of jasmonic acid is a fluorescence-based assay. The molecular recognition event for each metabolite is different: nanoparticle conjugation for salicylic acid, enzymatic reaction for azelaic acid and antibody-antigen recognition for jasmonic acid. In this work, two cultivars, Trincadeira and Carignan, presented infections with two fungal pathogens, Botrytis cinerea and Erysiphe necator. The grapes were tested using the microfluidic system alongside the benchmark techniques such as, high-performance liquid chromatography and enzyme-linked immunosorbent assay. The microfluidic system was not only capable of distinguishing infected from healthy samples, but also capable of distinguishing between different infection types.


Assuntos
Micoses , Vitis , Biomarcadores , Botrytis , Dispositivos Lab-On-A-Chip , Doenças das Plantas
5.
Proc Natl Acad Sci U S A ; 114(8): 2018-2023, 2017 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-28159892

RESUMO

Hepatitis C virus (HCV) encodes mechanisms to evade the multilayered antiviral actions of the host immune system. Great progress has been made in elucidating the strategies HCV employs to down-regulate interferon (IFN) production, impede IFN signaling transduction, and impair IFN-stimulated gene (ISG) expression. However, there is a limited understanding of the mechanisms governing how viral proteins counteract the antiviral functions of downstream IFN effectors due to the lack of an efficient approach to identify such interactions systematically. To study the mechanisms by which HCV antagonizes the IFN responses, we have developed a high-throughput profiling platform that enables mapping of HCV sequences critical for anti-IFN function at high resolution. Genome-wide profiling performed with a 15-nt insertion mutant library of HCV showed that mutations in the p7 region conferred high levels of IFN sensitivity, which could be alleviated by the expression of WT p7 protein. This finding suggests that p7 protein of HCV has an immune evasion function. By screening a liver-specific ISG library, we identified that IFI6-16 significantly inhibits the replication of p7 mutant viruses without affecting WT virus replication. In contrast, knockout of IFI6-16 reversed the IFN hypersensitivity of p7 mutant virus. In addition, p7 was found to be coimmunoprecipitated with IFI6-16 and to counteract the function of IFI6-16 by depolarizing the mitochondria potential. Our data suggest that p7 is a critical immune evasion protein that suppresses the antiviral IFN function by counteracting the function of IFI6-16.


Assuntos
Hepacivirus/patogenicidade , Hepatite C/imunologia , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune , Interferons/imunologia , Proteínas Mitocondriais/imunologia , Proteínas Virais/imunologia , Sistemas CRISPR-Cas , Linhagem Celular , Perfilação da Expressão Gênica , Técnicas de Inativação de Genes , Biblioteca Gênica , Genoma Viral , Hepacivirus/genética , Hepatite C/virologia , Humanos , Imunidade Inata , Interferons/genética , Interferons/metabolismo , Fígado/imunologia , Fígado/metabolismo , Potencial da Membrana Mitocondrial/imunologia , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Mutagênese Insercional , Transdução de Sinais , Proteínas Virais/genética , Replicação Viral
6.
Am J Occup Ther ; 74(5): 7405345010p1-7405345010p10, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804633

RESUMO

IMPORTANCE: Given the importance of proprioception in motor coordination, the identification of sensory deficits contributing to motor challenges is crucial for appropriate intervention; however, objective proprioceptive tests are not currently available in pediatric clinical practice. OBJECTIVE: To pilot test methods for assessing proprioception in children. Children with somatodyspraxia were predicted to have reduced proprioceptive awareness compared with age-matched control children. DESIGN: Observational study. SETTING: Individual clinic. PARTICIPANTS: Ten children identified as having somatodyspraxia and 10 typically developing children, ages 6-8 yr. OUTCOMES AND MEASURES: Spatial awareness and force perception were assessed by having the children match arm positions and grip and pinch forces using electronic dynamometers. RESULTS: All children were able to complete the proprioceptive assessments. Of those identified as having somatodyspraxia, 90% showed deficits in at least one area of proprioception. Children with somatodyspraxia performed more poorly on spatial awareness and force perception tests than typically developing children (p < .05). CONCLUSIONS AND RELEVANCE: Children with dyspraxia have difficulties with spatial awareness and force perception, confirming a somatosensory contribution to dyspraxia. WHAT THIS ARTICLE ADDS: This article presents a framework and methods to measure proprioception in children. These methods will allow occupational therapy practitioners to quantify the proprioceptive deficits common in children with dyspraxia.


Assuntos
Força da Mão , Propriocepção , Criança , Humanos , Projetos Piloto
7.
Analyst ; 144(16): 4871-4879, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31298663

RESUMO

Bacterial, fungal and viral infections in plant systems are on the rise, most of which tend to spread quickly amongst crops. These pathogens are also gaining resistance to known treatments, which makes their early detection a priority to avoid extensive loss of crops and the spreading of disease to animal systems. In this work, we propose a microfluidic platform coupled with integrated thin-film silicon photosensors for the detection of pathogen infections in grapes. This detection was achieved by monitoring the concentration of Azelaic Acid (AzA). This small organic acid plays a significant role in the defense mechanism in plant systems. In this platform, the enzyme tyrosinase was immobilized on microbeads inside a microfluidic system. By colorimetric monitoring of the inhibitory effect of AzA on the enzyme tyrosinase in real time, it was possible, in under 10 minutes, to detect different concentrations of AzA in both buffer and spiked solutions of grape juice, in both cases with limits of detection in the 5-10 nM range. In addition, with this microfluidic device, it was possible to clearly distinguish infected from healthy grape samples at three different grape maturation points. Healthy grape samples showed AzA concentrations in the range of 10-20 nM (post-dilution) while infected samples have an estimated increase of AzA of 10-30×, results which were confirmed using HPLC. In both juice and grape samples an integrated sample preparation stage that decreases the phenol content of the solutions was required to achieve fit-for-purpose sensitivities to AzA.


Assuntos
Ácidos Dicarboxílicos/análise , Dispositivos Lab-On-A-Chip , Doenças das Plantas/microbiologia , Vitis/microbiologia , Biomarcadores/análise , Biomarcadores/química , Colorimetria/métodos , Ácidos Dicarboxílicos/química , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/química , Enzimas Imobilizadas/química , Sucos de Frutas e Vegetais/análise , Limite de Detecção , Técnicas Analíticas Microfluídicas/métodos , Monofenol Mono-Oxigenase/antagonistas & inibidores , Monofenol Mono-Oxigenase/química
8.
J Neurophysiol ; 120(2): 497-508, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29668389

RESUMO

In this study, we investigated the responses to tread perturbations during human stepping on a treadmill. Our approach was to test the effects of perturbations to a single leg using a split-belt treadmill in healthy participants and in participants with varying severity of spinal cord injury (SCI). We recruited 11 people with incomplete SCI and 5 noninjured participants. As participants walked on an instrumented treadmill, the belt on one side was stopped or accelerated briefly during midstance to late stance. A majority of participants initiated an unnecessary swing when the treadmill was stopped in midstance, although the likelihood of initiating a step was decreased in participants with more severe SCI. Accelerating or decelerating one belt of the treadmill during stance altered the characteristics of swing. We observed delayed swing initiation when the belt was decelerated (i.e., the hip was in a more flexed position at time of swing) and advanced swing initiation with acceleration (i.e., hip extended at swing initiation). Furthermore, the timing and leg posture of heel strike appeared to remain constant, reflected by a sagittal plane hip angle at heel strike that remained the same regardless of the perturbation. In summary, our results supported the current understanding of the role of sensory feedback and central drive in the control of stepping in participants with incomplete SCI and noninjured participants. In particular, the observation of unnecessary swing during a stop perturbation highlights the interdependence of central and sensory drive in walking control. NEW & NOTEWORTHY Using a novel approach with a split-belt treadmill, we tested the effects of hip angle perturbations to a single leg in healthy participants and participants with varying severity of spinal cord injury (SCI). A majority of participants initiated an unnecessary swing when the treadmill was stopped in midstance, although the likelihood of initiating a step decreased with the severity of SCI. Our results demonstrated interdependence of central and sensory drive in walking control.


Assuntos
Atividade Motora , Traumatismos da Medula Espinal/fisiopatologia , Caminhada , Adulto , Idoso , Fenômenos Biomecânicos , Teste de Esforço , Feminino , Marcha , Humanos , Masculino , Pessoa de Meia-Idade
9.
Analyst ; 143(5): 1015-1035, 2018 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-29384153

RESUMO

The assurance of food and feed safety, including the identification and effective monitoring of multiple biological and chemical hazards, is a major societal challenge, given the increasing pace at which food commodities are demanded, produced and traded across the globe. Within this context, mycotoxins are globally widespread secondary fungal metabolites, which can contaminate crops either in the field or during storage and have serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Therefore, their presence in a wide range of foods and feeds is strictly regulated, particularly in the European Union. In order to perform effective and routine monitoring of mycotoxin levels in the field prior to further processing, during transport or during processing, rapid, simple, portable and sensitive means of screening of regulated mycotoxins are in high demand. This review focuses on (1) discussing the relevance of mycotoxins and the standard approaches for their sampling and monitoring; and (2) compiling and discussing recent advances in miniaturized analytical tools for mycotoxin detection. This provides insights into current research efforts and opportunities to develop a truly integrated and fit-for-purpose analytical tool, suitable for use at critical points of the food, feed and raw material processing and distribution chains.


Assuntos
Ração Animal/análise , Contaminação de Alimentos/análise , Micotoxinas/análise , Animais , Microbiologia de Alimentos , Fungos , Humanos
10.
Anal Chem ; 88(16): 7959-67, 2016 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-27405388

RESUMO

Multimodal ligands are synthetic molecules comprising multiple types of interactions that have been increasingly used for the capture of different biopharmaceutical compounds within complex biological mixtures. For monoclonal antibodies (mAbs) in particular, these ligands have shown the possibility of direct capture from cell culture supernatants in native conditions, as well as enhanced selectivity and affinity compared to traditional single-mode ligands. However, performing the capture of a target mAb using multimodal chromatography comes with the need for extensive optimization of the operating conditions, due to the multitude of interactions that can be promoted in parallel. In this work, a high-throughput microfluidic platform was developed for the optimization of chromatographic conditions regarding the capture of an anti-interleukin 8 mAb, using a multimodal ligand (2-benzamido-4-mercaptobutanoic acid), under a wide range of buffer pH and conductivities. The interaction of the ligand with the fluorescently labeled target mAb was also analyzed with respect to the individual contribution of the hydrophobic (phenyl) and electrostatic (carboxyl) moieties using fluorescence microscopy. The results were further validated at the macroscale using prepacked columns in standard chromatography assays, and recovery yield values of 94.6% ± 5.2% and 97.7% ± 1.5% were obtained under optimal conditions for the miniaturized and conventional approaches, respectively. In summary, this study highlights that a microfluidic-based approach is a powerful analytical tool to expedite the optimization process while using reduced reagent volumes (<50 µL), less resin (∼70 nL), and delivering results in less than 1 min per assay condition.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Dimetilpolisiloxanos/química , Ensaios de Triagem em Larga Escala , Técnicas Analíticas Microfluídicas , Adsorção , Anticorpos Monoclonais/química , Ensaios de Triagem em Larga Escala/instrumentação , Ligantes , Técnicas Analíticas Microfluídicas/instrumentação , Estrutura Molecular , Tamanho da Partícula
11.
PLoS Pathog ; 10(4): e1004064, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24722365

RESUMO

Widely used chemical genetic screens have greatly facilitated the identification of many antiviral agents. However, the regions of interaction and inhibitory mechanisms of many therapeutic candidates have yet to be elucidated. Previous chemical screens identified Daclatasvir (BMS-790052) as a potent nonstructural protein 5A (NS5A) inhibitor for Hepatitis C virus (HCV) infection with an unclear inhibitory mechanism. Here we have developed a quantitative high-resolution genetic (qHRG) approach to systematically map the drug-protein interactions between Daclatasvir and NS5A and profile genetic barriers to Daclatasvir resistance. We implemented saturation mutagenesis in combination with next-generation sequencing technology to systematically quantify the effect of every possible amino acid substitution in the drug-targeted region (domain IA of NS5A) on replication fitness and sensitivity to Daclatasvir. This enabled determination of the residues governing drug-protein interactions. The relative fitness and drug sensitivity profiles also provide a comprehensive reference of the genetic barriers for all possible single amino acid changes during viral evolution, which we utilized to predict clinical outcomes using mathematical models. We envision that this high-resolution profiling methodology will be useful for next-generation drug development to select drugs with higher fitness costs to resistance, and also for informing the rational use of drugs based on viral variant spectra from patients.


Assuntos
Farmacorresistência Viral , Perfilação da Expressão Gênica , Aptidão Genética , Hepacivirus/fisiologia , Hepatite C , Imidazóis/farmacologia , Replicação Viral , Carbamatos , Linhagem Celular , Farmacorresistência Viral/efeitos dos fármacos , Farmacorresistência Viral/genética , Hepatite C/tratamento farmacológico , Hepatite C/genética , Hepatite C/metabolismo , Hepatite C/patologia , Humanos , Pirrolidinas , Valina/análogos & derivados , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacos , Replicação Viral/genética
12.
Malar J ; 14: 375, 2015 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-26415942

RESUMO

BACKGROUND: The major Neotropical malaria vector, Anopheles darlingi, was reintroduced into the Iquitos, Loreto, Peru area during the early 1990s, where it displaced other anophelines and caused a major malaria epidemic. Since then, case numbers in Loreto have fluctuated, but annual increases have been reported since 2012. METHODS: The population genetic structure of An. darlingi sampled before and after the introduction of long-lasting insecticidal nets (LLINs) was investigated to test the hypothesis of temporal population change (2006 vs. 2012). Current samples of An. darlingi were used to test the hypothesis of ecological adaptation to human modified (highway) compared with wild (riverine) habitat, linked to forest cover. In total, 693 An. darlingi from nine localities in Loreto, Peru area were genotyped using 13 microsatellite loci. To test the hypothesis of habitat differentiation in An. darlingi biting time patterns, HBR and EIR, four collections of An. darlingi from five localities (two riverine and three highway) were analysed. RESULTS: Analyses of microsatellite loci from seven (2006) and nine settlements (2012-2014) in the Iquitos area detected two distinctive populations with little overlap, although it is unclear whether this population replacement event is associated with LLIN distribution or climate. Within the 2012-2014 population two admixed subpopulations, A and B, were differentiated by habitat, with B significantly overrepresented in highway, and both in near-equal proportions in riverine. Both subpopulations had a signature of expansion and there was moderate genetic differentiation between them. Habitat and forest cover level had significant effects on HBR, such that Plasmodium transmission risk, as measured by EIR, in peridomestic riverine settlements was threefold higher than in peridomestic highway settlements. HBR was directly associated with available host biomass rather than forest cover. CONCLUSIONS: A population replacement event occurred between 2006 and 2012-2014, concurrently with LLIN distribution and a moderate El Niño event, and prior to an increase in malaria incidence. The likely drivers of this replacement cannot be determined with current data. The present-day An. darlingi population is composed of two highly admixed subpopulations, which appear to be in an early stage of differentiation, triggered by anthropogenic alterations to local habitat.


Assuntos
Anopheles/genética , Anopheles/fisiologia , Insetos Vetores/genética , Insetos Vetores/fisiologia , Malária/transmissão , Animais , DNA de Protozoário/genética , Feminino , Genética Populacional , Humanos , Mordeduras e Picadas de Insetos , Repetições de Microssatélites/genética , Peru/epidemiologia , Floresta Úmida , Asas de Animais
13.
Analyst ; 140(13): 4423-33, 2015 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-25988197

RESUMO

As a leading cause of cancer-related deaths in men globally, prostate cancer (PCa) demands immense attention for theranostic purposes. There is an increasing need for the development of rapid, sensitive, economical, miniaturized and multiplexable assays. Towards this goal, we present a systematic approach for the optimisation of a microfluidic sandwich immunoassay, which can be applied as a generic biosensor platform for PCa detection. Prostate specific antigen (PSA) was used as the model biomarker, and its free form was captured using commercially available antibodies and detected using chemiluminescence, both in spiked buffer and matrix solutions. Along with the optimisation of surface chemistry and microfluidic parameters, we report a bio-affinity amplification strategy based on biotin-streptavidin chemistry to bring the limits of detection for free-PSA from 21.4 ng mL(-1) down to 2.7 ng mL(-1), within the clinically relevant range. An estimate of the surface coverage and simulations of the interactions taking place in the microfluidic biosensor during the assay are also presented. This novel platform using a simple passive adsorption-based bio-affinity strategy, when coupled with multiplexing and integrated detection, can serve as a promising point-of-care diagnostic tool for PCa.


Assuntos
Biomarcadores Tumorais/análise , Microfluídica/métodos , Antígeno Prostático Específico/análise , Animais , Humanos , Imunoensaio/métodos , Masculino , Camundongos
14.
Mem Inst Oswaldo Cruz ; 110(4): 573-6, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26061150

RESUMO

We describe a simple method for detection of Plasmodium vivax and Plasmodium falciparum infection in anophelines using a triplex TaqMan real-time polymerase chain reaction (PCR) assay (18S rRNA). We tested the assay on Anopheles darlingi and Anopheles stephensi colony mosquitoes fed with Plasmodium-infected blood meals and in duplicate on field collected An. darlingi. We compared the real-time PCR results of colony-infected and field collected An. darlingi, separately, to a conventional PCR method. We determined that a cytochrome b-PCR method was only 3.33% as sensitive and 93.38% as specific as our real-time PCR assay with field-collected samples. We demonstrate that this assay is sensitive, specific and reproducible.


Assuntos
Anopheles/parasitologia , Insetos Vetores/parasitologia , Plasmodium falciparum/genética , Plasmodium vivax/genética , Reação em Cadeia da Polimerase em Tempo Real , Animais , Citocromos b/genética , Plasmodium falciparum/isolamento & purificação , Plasmodium vivax/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Analyst ; 139(15): 3709-13, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24922601

RESUMO

A hydrogenated amorphous silicon (a-Si:H) photosensor was explored for the quantitative detection of a HIV-1 virion infectivity factor (Vif) at a detection limit in the single nanomolar range. The a-Si:H photosensor was coupled with a microfluidic channel that was functionalized with a recombinant single chain variable fragment antibody. The biosensor selectively recognizes HIV-1 Vif from human cell extracts.


Assuntos
Infecções por HIV/diagnóstico , Infecções por HIV/virologia , HIV-1/isolamento & purificação , Técnicas Analíticas Microfluídicas/instrumentação , Silício/química , Produtos do Gene vif do Vírus da Imunodeficiência Humana/isolamento & purificação , Células HEK293 , Humanos , Óptica e Fotônica/instrumentação
16.
Arch Phys Med Rehabil ; 95(4): 622-32, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24269485

RESUMO

OBJECTIVE: To investigate the effects of antispastic drugs baclofen and tizanidine on reflexes and volitional tasks. DESIGN: Double-blind, placebo-controlled, crossover, before-after trial, pilot study. SETTING: Research laboratory in a rehabilitation hospital. PARTICIPANTS: Men with chronic (>6mo) motor incomplete spinal cord injury (N=10) were recruited for the study. INTERVENTIONS: Tizanidine, baclofen, and placebo were tested in this study. Agents were tested in separate experimental sessions separated by >1 week. MAIN OUTCOME MEASURES: Reflex and strength were measured before and after the administration of a single dose of each intervention agent. Electromyographic and joint torque data were collected during assessments of plantar flexor stretch reflexes, maximum contraction during motor-assisted isokinetic movements, and maximum isometric knee extension and flexion. RESULTS: Reduced stretch reflex activity was observed after the administration of either tizanidine or baclofen. We observed that tizanidine had a stronger inhibitory effect on knee extensors and plantar flexors whereas baclofen had a stronger inhibitory effect on the knee flexors. The effects of these drugs on strength during isometric and isokinetic tasks varied across participants, without a consistent reduction in torque output despite decreased electromyographic activity. CONCLUSIONS: These results suggest that antispastic drugs are effective in reducing stretch reflexes without substantially reducing volitional torque. Differential effects of tizanidine and baclofen on reflexes of flexors and extensors warrant further investigation into patient-specific management of antispastic drugs.


Assuntos
Contração Isométrica/efeitos dos fármacos , Relaxantes Musculares Centrais/farmacologia , Reflexo de Estiramento/efeitos dos fármacos , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Baclofeno/farmacologia , Clonidina/análogos & derivados , Clonidina/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Eletromiografia , Humanos , Contração Isométrica/fisiologia , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Força Muscular/efeitos dos fármacos , Força Muscular/fisiologia , Projetos Piloto , Reflexo de Estiramento/fisiologia , Torque
17.
Biosensors (Basel) ; 14(3)2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38534230

RESUMO

Viticulture and associated products are an important part of the economy in many countries. However, biotic and abiotic stresses impact negatively the production of grapes and wine. Climate change is in many aspects increasing both these stresses. Routine sample retrievals and analysis tend to be time-consuming and require expensive equipment and skilled personnel to operate. These challenges could be overcome through the development of a miniaturized analytic device for early detection of grapevine stresses in the field. Abscisic acid is involved in several plant processes, including the onset of fruit ripening and tolerance mechanisms against drought stress. This hormone can be detected through a competitive immunoassay and is found in plants in concentrations up to 10-1 mg/mL. A microfluidic platform is developed in this work which can detect a minimum of 10-11 mg/mL of abscisic acid in buffer. Grape samples were tested using the microfluidic system alongside benchmark techniques such as high-performance liquid chromatography. The microfluidic system could detect the increase to 10-5 mg/mL of abscisic acid present in real berry samples at the veraison stage of ripening.


Assuntos
Vitis , Vinho , Ácido Abscísico , Microfluídica , Imunoensaio
18.
J Neurophysiol ; 109(8): 2169-78, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23343896

RESUMO

Successful reaching requires that we plan movements to compensate for variability in motor output. Previous studies have shown that healthy adults optimally incorporate estimates of motor variability when planning a pointing task. Children with dystonia have increased variability compared with healthy children. It is not known whether they are able to compensate appropriately for the increased variability and whether this compensation leads to changes in reaching behavior. We examined healthy children and those with increased motor variability due to secondary dystonia. Using a simple virtual display, children performed a motor task where the variability of their movements was manipulated. Results showed that both subject groups changed their movement strategies in response to changes in the level of perceived motor variability. Both groups changed their strategy in a way that improved performance relative to the perceived motor variability. Importantly, dystonic children faced with decreased motor variability adapted their movement strategy to perform better and more similarly to healthy children. These findings show that both healthy and dystonic children are able to respond to changes in motor variability and alter their movement strategies.


Assuntos
Distúrbios Distônicos/fisiopatologia , Destreza Motora , Adolescente , Análise de Variância , Fenômenos Biomecânicos , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Movimento
19.
Electrophoresis ; 34(4): 575-82, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23175163

RESUMO

The spatial and temporal control of biological species is essential in complex microfluidic biosystems. In addition, if the biological species is a cell, microfluidic handling must ensure that the cell's metabolic viability is maintained. The use of DEP for cell manipulation in microfluidics has many advantages because it is remote and fast, and the voltages required for cell trapping scale well with miniaturization. In this paper, the conditions for bacterial cell (Escherichia coli) trapping using a quadrupole electrode configuration in a PDMS microfluidic channel were developed both for stagnant and for in-flow fluidic situations. The effect of the electrical conductivity of the fluid, the applied electric field and frequency, and the fluid-flow velocity were studied. A dynamic exchange between captured and free-flowing cells during DEP trapping was demonstrated. The metabolic activity of trapped cells was confirmed by using E. coli cells genetically engineered to express green fluorescent protein under the control of an inducible promoter. Noninduced cells trapped by negative DEP and positive DEP were able to express green fluorescent protein minutes after the inducer was inserted in the microchannel system immediately after DEP trapping. Longer times of trapping prior to exposure to the inducer indicated first a degradation of the cell metabolic activity and finally cell death.


Assuntos
Sobrevivência Celular/fisiologia , Células Imobilizadas/metabolismo , Eletroforese/métodos , Escherichia coli/metabolismo , Técnicas Analíticas Microfluídicas/métodos , Células Imobilizadas/citologia , Simulação por Computador , Condutividade Elétrica , Escherichia coli/citologia , Proteínas de Fluorescência Verde/química , Proteínas Recombinantes/química
20.
Physiother Theory Pract ; 39(11): 2314-2326, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-35581534

RESUMO

Idiopathic toe-walking (ITW) refers to persistent walking without heel contact for unknown reasons. An underexplored area is the relationship of sensory processing to ITW. This study presents methods to assess sensory differences in individuals with ITW and summarizes results from a pilot testing of the measures. This pilot study included nine children and one young adult with ITW. Ten age-matched controls were recruited to provide a comparison group when norms were not available in the literature. The measures included in this study were as follows: sensory questionnaires; electrodermal activity response to sensory stimuli; monofilaments; biothesiometer; gait on different surfaces; NeuroCom® SMART Balance Master® Sensory Organization Test and Adaptation Test; and ankle position matching. All study procedures were completed in about 3 hours. Children as young as 4 years were able to complete the measures. We observed overall differences in sensory processing, specifically, higher Sensory Processing Measure scores (p = .011), higher resting electrodermal activity (p = .012), increases in heel-toe walking on novel surfaces (p = .034), and more falls with balance perturbation (p = .007) in individuals with ITW. A subset of individuals also showed tactile hyposensitivity (5 out of 10 in the ITW group) and poor equilibrium scores in the Sensory Organization Test (4 out of 9 in the ITW group, 1 unable to complete the test). Our results confirmed the heterogeneity in the etiology of ITW. We propose that further testing in sensory modulation, tactile processing, and vestibular processing is needed to fully explore the impact of sensory processing on children with ITW.


Assuntos
Transtornos dos Movimentos , Dedos do Pé , Adulto Jovem , Criança , Humanos , Projetos Piloto , Dedos do Pé/fisiologia , Marcha/fisiologia , Caminhada/fisiologia , Percepção
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