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1.
Cell ; 183(6): 1665-1681.e18, 2020 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-33188776

RESUMEN

We present deterministic barcoding in tissue for spatial omics sequencing (DBiT-seq) for co-mapping of mRNAs and proteins in a formaldehyde-fixed tissue slide via next-generation sequencing (NGS). Parallel microfluidic channels were used to deliver DNA barcodes to the surface of a tissue slide, and crossflow of two sets of barcodes, A1-50 and B1-50, followed by ligation in situ, yielded a 2D mosaic of tissue pixels, each containing a unique full barcode AB. Application to mouse embryos revealed major tissue types in early organogenesis as well as fine features like microvasculature in a brain and pigmented epithelium in an eye field. Gene expression profiles in 10-µm pixels conformed into the clusters of single-cell transcriptomes, allowing for rapid identification of cell types and spatial distributions. DBiT-seq can be adopted by researchers with no experience in microfluidics and may find applications in a range of fields including developmental biology, cancer biology, neuroscience, and clinical pathology.


Asunto(s)
Código de Barras del ADN Taxonómico , Genómica , Especificidad de Órganos/genética , Animales , Automatización , Encéfalo/embriología , Análisis por Conglomerados , ADN Complementario/genética , Embrión de Mamíferos/metabolismo , Ojo/embriología , Femenino , Regulación del Desarrollo de la Expresión Génica , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Ratones Endogámicos C57BL , Microfluídica , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reproducibilidad de los Resultados , Análisis de la Célula Individual , Transcriptoma/genética
2.
Blood ; 141(20): 2508-2519, 2023 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-36800567

RESUMEN

Proinflammatory signaling is a hallmark feature of human cancer, including in myeloproliferative neoplasms (MPNs), most notably myelofibrosis (MF). Dysregulated inflammatory signaling contributes to fibrotic progression in MF; however, the individual cytokine mediators elicited by malignant MPN cells to promote collagen-producing fibrosis and disease evolution are yet to be fully elucidated. Previously, we identified a critical role for combined constitutive JAK/STAT and aberrant NF-κB proinflammatory signaling in MF development. Using single-cell transcriptional and cytokine-secretion studies of primary cells from patients with MF and the human MPLW515L (hMPLW515L) murine model of MF, we extend our previous work and delineate the role of CXCL8/CXCR2 signaling in MF pathogenesis and bone marrow fibrosis progression. Hematopoietic stem/progenitor cells from patients with MF are enriched for a CXCL8/CXCR2 gene signature and display enhanced proliferation and fitness in response to an exogenous CXCL8 ligand in vitro. Genetic deletion of Cxcr2 in the hMPLW515L-adoptive transfer model abrogates fibrosis and extends overall survival, and pharmacologic inhibition of the CXCR1/2 pathway improves hematologic parameters, attenuates bone marrow fibrosis, and synergizes with JAK inhibitor therapy. Our mechanistic insights provide a rationale for therapeutic targeting of the CXCL8/CXCR2 pathway among patients with MF.


Asunto(s)
Trastornos Mieloproliferativos , Neoplasias , Mielofibrosis Primaria , Humanos , Ratones , Animales , Mielofibrosis Primaria/patología , Trastornos Mieloproliferativos/genética , Transducción de Señal , Neoplasias/complicaciones , Citocinas/metabolismo , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo
3.
Nanotechnology ; 33(47)2022 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-35944420

RESUMEN

Crystallographically anisotropic two-dimensional (2D) molybdenum disulfide (MoS2) with vertically aligned (VA) layers is attractive for electrochemical sensing owing to its surface-enriched dangling bonds coupled with extremely large mechanical deformability. In this study, we explored VA-2D MoS2layers integrated on cellulose nanofibers (CNFs) for detecting various volatile organic compound gases. Sensor devices employing VA-2D MoS2/CNFs exhibited excellent sensitivities for the tested gases of ethanol, methanol, ammonia, and acetone; e.g. a high response rate up to 83.39% for 100 ppm ethanol, significantly outperforming previously reported sensors employing horizontally aligned 2D MoS2layers. Furthermore, VA-2D MoS2/CNFs were identified to be completely dissolvable in buffer solutions such as phosphate-buffered saline solution and baking soda buffer solution without releasing toxic chemicals. This unusual combination of high sensitivity and excellent biodegradability inherent to VA-2D MoS2/CNFs offers unprecedented opportunities for exploring mechanically reconfigurable sensor technologies with bio-compatible transient characteristics.

4.
Sensors (Basel) ; 21(13)2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34203163

RESUMEN

Cellulose and its derivatives have evoked much attention in sensor technology as host-matrices for conducting materials because of their versatility, renewability, and biocompatibility. However, only a few studies have dealt with the potential utilization of cellulose as a sensing material without a composite structure. In this study, cellulose nanofibers (CNF) and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF) extracted from rice husks by using ultrasonic-assisted methods are introduced as a potential gas sensing material with highly sensitive performance. To fabricate nanocellulose-based films, CNF, TOCNF, and TOCNF with glycerol (TOCNF/G) were dispersed in water and applied on polyimide substrate with digital electrodes to form self-standing thin films by a drop-casting method. A transparent coating layer on the surface of the plate after drying is used for the detection of water-soluble gases such as acetone, ammonia, methane, and hydrogen sulfide gases at room temperature at 52% relative humidity. The sensor prototypes exhibited high sensitivity, and the detection limit was between 1 ppm and 5 ppm, with less than 10 min response and recovery time. The results indicate that both the CNF- and the TOCNF-coated sensors show good sensitivity toward ammonia and acetone, compared to other gases. A TOCNF/G-coated sensor exhibited minimum time in regard to response/recovery time, compared to a CNF-coated sensor. In this study, nanocellulose-based sensors were successfully fabricated using a low-cost process and a bio-based platform. They showed good sensitivity for the detection of various gases under ambient conditions. Therefore, our study results should further propel in-depth research regarding various applications of cellulose-based sensors in the future.


Asunto(s)
Nanofibras , Oryza , Celulosa , Gases , Agua
5.
Sensors (Basel) ; 21(19)2021 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-34640703

RESUMEN

This study proposes the development of a wireless sensor system integrated with smart ultra-high performance concrete (UHPC) for sensing and transmitting changes in stress and damage occurrence in real-time. The smart UHPC, which has the self-sensing ability, comprises steel fibers, fine steel slag aggregates (FSSAs), and multiwall carbon nanotubes (MWCNTs) as functional fillers. The proposed wireless sensing system used a low-cost microcontroller unit (MCU) and two-probe resistance sensing circuit to capture change in electrical resistance of self-sensing UHPC due to external stress. For wireless transmission, the developed wireless sensing system used Bluetooth low energy (BLE) beacon for low-power and multi-channel data transmission. For experimental validation of the proposed smart UHPC, two types of specimens for tensile and compression tests were fabricated. In the laboratory test, using a universal testing machine, the change in electrical resistivity was measured and compared with a reference DC resistance meter. The proposed wireless sensing system showed decreased electrical resistance under compressive and tensile load. The fractional change in resistivity (FCR) was monitored at 39.2% under the maximum compressive stress and 12.35% per crack under the maximum compressive stress tension. The electrical resistance changes in both compression and tension showed similar behavior, measured by a DC meter and validated the developed integration of wireless sensing system and smart UHPC.

6.
Sensors (Basel) ; 21(19)2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34640992

RESUMEN

Motor imagery (MI) brain-computer interfaces (BCIs) have been used for a wide variety of applications due to their intuitive matching between the user's intentions and the performance of tasks. Applying dry electroencephalography (EEG) electrodes to MI BCI applications can resolve many constraints and achieve practicality. In this study, we propose a multi-domain convolutional neural networks (MD-CNN) model that learns subject-specific and electrode-dependent EEG features using a multi-domain structure to improve the classification accuracy of dry electrode MI BCIs. The proposed MD-CNN model is composed of learning layers for three domain representations (time, spatial, and phase). We first evaluated the proposed MD-CNN model using a public dataset to confirm 78.96% classification accuracy for multi-class classification (chance level accuracy: 30%). After that, 10 healthy subjects participated and performed three classes of MI tasks related to lower-limb movement (gait, sitting down, and resting) over two sessions (dry and wet electrodes). Consequently, the proposed MD-CNN model achieved the highest classification accuracy (dry: 58.44%; wet: 58.66%; chance level accuracy: 43.33%) with a three-class classifier and the lowest difference in accuracy between the two electrode types (0.22%, d = 0.0292) compared with the conventional classifiers (FBCSP, EEGNet, ShallowConvNet, and DeepConvNet) that used only a single domain. We expect that the proposed MD-CNN model could be applied for developing robust MI BCI systems with dry electrodes.


Asunto(s)
Algoritmos , Interfaces Cerebro-Computador , Electrodos , Electroencefalografía , Humanos , Redes Neurales de la Computación
7.
Cell Immunol ; 355: 104155, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32619811

RESUMEN

The IL-7 receptor alpha chain (IL-7Rα or CD127) can be differentially expressed in memory CD8+ T cells. Here we investigated whether IL-7Rα could serve as a key molecule in defining a comprehensive landscape of heterogeneity in human effector memory (EM) CD8+ T cells using high-dimensional Cytometry by Time-Of-Flight (CyTOF) and single-cell RNA-seq (scRNA-seq). IL-7Rα had diverse, but organized, expressional relationship in EM CD8+ T cells with molecules related to cell function and gene regulation, which rendered an immune landscape defining heterogeneous cell subsets. The differential expression of these molecules likely has biological implications as we found in vivo signatures of transcription factors and homeostasis cytokine receptors, including T-bet and IL-7Rα. Our findings indicate the existence of heterogeneity in human EM CD8+ T cells as defined by distinct but organized expression patterns of multiple molecules in relationship to IL-7Rα and its possible biological significance in modulating downstream events.


Asunto(s)
Linfocitos T CD8-positivos/metabolismo , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Adulto , Linfocitos T CD8-positivos/inmunología , Femenino , Citometría de Flujo/métodos , Humanos , Memoria Inmunológica , Subunidad alfa del Receptor de Interleucina-7/genética , Subunidad alfa del Receptor de Interleucina-7/inmunología , Masculino , Análisis de Secuencia de ARN/métodos , Análisis de la Célula Individual/métodos
8.
Biotechnol Bioeng ; 115(10): 2624-2631, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29896880

RESUMEN

Globally, approximately a billion patients are estimated to suffer from neurological disorders. Although there are many therapeutic candidates for the central nervous system, treatment of brain disorders is restricted by the blood-brain barrier (BBB), which is a highly selective membrane that protects the brain from exogenous substances. This study was undertaken to develop a novel strategy to overcome the BBB and improve the efficiency of drug delivery to the brain by mechanical load increase using hypergravity. Human cerebral microvascular endothelial cells were exposed three times to 20 min hypergravity (10g), with a 20-min rest period between each exposure. The applied hypergravity reversibly decreased the cellular metabolic activity and increased the permeation rate of fluorescein sodium salt, fluorescein isothiocyanate-labeled dextran (FD-4), and fluorescein-labeled jacalin. Following the exposure to hypergravity, we also observed structural changes of the cytoskeleton and tight junctions, and an alteration in the expression levels of related genes. These results indicate that increased mechanical load due to the applied hypergravity affects the cytoskeletal arrangement and tight junctions, thereby weakening the cell barrier function and enhancing the permeability of the paracellular pathway. Thus, the mechanical load increase by hypergravity has the potential of being used as a novel strategy to overcome the BBB for brain drug delivery.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Citoesqueleto/metabolismo , Células Endoteliales/metabolismo , Hipergravedad/efectos adversos , Estrés Mecánico , Uniones Estrechas/metabolismo , Barrera Hematoencefálica/citología , Línea Celular , Sistemas de Liberación de Medicamentos , Células Endoteliales/citología , Fluoresceína/química , Fluoresceína/farmacocinética , Fluoresceína/farmacología , Humanos , Permeabilidad , Lectinas de Plantas/química , Lectinas de Plantas/farmacocinética , Lectinas de Plantas/farmacología
9.
Acta Neurochir Suppl ; 126: 233-236, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29492567

RESUMEN

OBJECTIVE: The phase-contrast MRI technique permits the non-invasive assessment of CSF movements in cerebrospinal fluid cavities of the central nervous system. Of particular interest is pulsatile cerebrospinal fluid (CSF) flow through the aqueduct cerebri. It is allegedly increased in hydrocephalus, having potential diagnostic value, although not all scientific reports contain unequivocally positive conclusions. METHODS: For the mathematical simulation of CSF flow, we used a computational model of cerebrospinal blood/fluid circulation designed by a former student as his PhD project. With this model, cerebral blood flow and CSF may be simulated in various vessels using a system of non-linear differential equations as time-varying signals. RESULTS: The amplitude of CSF flow seems to be positively related to the amplitude of pulse waveforms of intracranial pressure (ICP) in situations where mean ICP increases, such as during simulated infusion tests and following step increases of resistance to CSF outflow. An additional positive association between the pulse amplitude of ICP and CSF flow can be seen during simulated increases in the amplitude of arterial pulses (without changes in mean arterial pressure, MAP). The opposite effect can be observed during step increases in the resistance of the aqueduct cerebri and with decreasing elasticity of the system, where the CSF flow amplitude and the ICP pulse amplitude are related inversely. Vasodilatation caused by both gradual decreases in MAP and by increases in PaCO2 provokes an elevation in the observed amplitude of pulsatile CSF flow. CONCLUSIONS: Preliminary results indicate that the pulsations of CSF flow may carry information about both CSF-circulatory and cerebral vasogenic components. In most cases, the pulsations of CSF flow are positively related to the pulse amplitudes of both arterial pressure and ICP and to a degree of cerebrovascular dilatation.


Asunto(s)
Acueducto del Mesencéfalo/diagnóstico por imagen , Líquido Cefalorraquídeo , Circulación Cerebrovascular/fisiología , Presión Intracraneal/fisiología , Flujo Pulsátil/fisiología , Humanos , Hidrodinámica , Imagen por Resonancia Magnética , Modelos Teóricos , Dinámicas no Lineales , Programas Informáticos
10.
Acta Neurochir (Wien) ; 160(12): 2277-2287, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30251196

RESUMEN

BACKGROUND: Continuous assessment of cerebral compensatory reserve is possible using the moving correlation between pulse amplitude of intra-cranial pressure (AMP) and intra-cranial pressure (ICP), called RAP. Little is known about the behavior and associations of this index in adult traumatic brain injury (TBI). The goal of this study is to evaluate the association between admission cerebral imaging findings and RAP over the course of the acute intensive care unit stay. METHODS: We retrospectively reviewed 358 adult TBI patients admitted to the Addenbrooke's Hospital, University of Cambridge, from March 2005 to December 2016. Only non-craniectomy patients were studied. Using archived high frequency physiologic signals, RAP was derived and analyzed over the first 48 h and first 10 days of recording in each patient, using grand mean, percentage of time above various thresholds, and integrated area under the curve (AUC) of RAP over time. Associations between these values and admission computed tomography (CT) injury characteristics were evaluated. RESULTS: The integrated AUC, based on various thresholds of RAP, was statistically associated with admission CT markers of diffuse TBI and cerebral edema. Admission CT findings of cortical gyral effacement, lateral ventricle compression, diffuse cortical subarachnoid hemorrhage (SAH), thickness of cortical SAH, presence of bilateral contusions, and subcortical diffuse axonal injury (DAI) were all associated with AUC of RAP over time. Joncheere-Terpstra testing indicated a statistically significant increase in mean RAP AUC across ordinal categories of the abovementioned associated CT findings. CONCLUSIONS: RAP is associated with cerebral CT injury patterns of diffuse injury and edema, providing some confirmation of its potential measurement of cerebral compensatory reserve in TBI.


Asunto(s)
Edema Encefálico/diagnóstico por imagen , Lesiones Traumáticas del Encéfalo/diagnóstico por imagen , Hemorragia Cerebral/diagnóstico por imagen , Lesión Axonal Difusa/diagnóstico por imagen , Adulto , Edema Encefálico/etiología , Lesiones Traumáticas del Encéfalo/complicaciones , Hemorragia Cerebral/etiología , Lesión Axonal Difusa/etiología , Femenino , Humanos , Presión Intracraneal , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X
11.
Acta Neurochir (Wien) ; 160(5): 1097-1103, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29520439

RESUMEN

INTRODUCTION: The so-called Davson's equation relates baseline intracranial pressure (ICP) to resistance to cerebrospinal fluid outflow (Rout), formation of cerebrospinal fluid (If) and sagittal sinus pressure (PSS) There is a controversy over whether this fundamental equation is applicable in patients with normal pressure hydrocephalus (NPH). We investigated the relationship between Rout and ICP and also other compensatory, clinical and demographic parameters in NPH patients. METHOD: We carried out a retrospective study of 229 patients with primary NPH who had undergone constant-rate infusion studies in our hospital. Data was recorded and processed using ICM+ software. Relationships between variables were sought by calculating Pearson product correlation coefficients and p values. RESULTS: We found a significant, albeit weak, relationship between ICP and Rout (R = 0.17, p = 0.0049), Rout and peak-to-peak amplitude of ICP (AMP) (R = 0.27, p = 3.577e-05) and Rout and age (R = 0.16, p = 0.01306). CONCLUSIONS: The relationship found between ICP and Rout provides indirect evidence to support disturbed Cerebrospinal fluid circulation as a key factor in disturbed CSF dynamics in NPH. Weak correlation may indicate that other factors-variable PSS and formation of CSF outflow-contribute heavily to linear model expressed by Davson's equation.


Asunto(s)
Hidrocéfalo Normotenso/diagnóstico , Presión Intracraneal/fisiología , Anciano , Anciano de 80 o más Años , Senos Craneales , Femenino , Humanos , Hidrocéfalo Normotenso/fisiopatología , Masculino , Estudios Retrospectivos , Programas Informáticos
12.
J Korean Med Sci ; 33(48): e306, 2018 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-30473650

RESUMEN

This study examined the add-on efficacy of eye movement desensitization and reprocessing (EMDR) therapy among adult civilians with post-traumatic stress disorder (PTSD) who continued to be symptomatic after more than 12 weeks of initial antidepressant treatment. Scores for the Clinician Administered PTSD Scale (CAPS) were rated pre- and post-EMDR and at a 6-month follow-up. After an average of six sessions of EMDR treatment, seven of 14 patients (50%) showed more than a 30% decrease in CAPS score and eight (57%) no longer met the criteria for PTSD. Our results indicate that EMDR could be successfully added after failure of initial pharmacotherapy for PTSD.


Asunto(s)
Antidepresivos/uso terapéutico , Desensibilización y Reprocesamiento del Movimiento Ocular/métodos , Movimientos Oculares/fisiología , Trastornos por Estrés Postraumático/tratamiento farmacológico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Psicoterapia , Insuficiencia del Tratamiento , Adulto Joven
13.
Sensors (Basel) ; 18(10)2018 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-30301181

RESUMEN

Few studies have investigated the gas-sensing properties of graphene oxide/titanium dioxide (GO/TiO2) composite combined with photocatalytic effect. Room temperature gas-sensing properties of the GO/TiO2 composite were investigated towards various reducing gases. The composite sensor showed an enhanced gas response and a faster recovery time than a pure GO sensor due to the synergistic effect of the hybridization, such as creation of a hetero-junction at the interface and modulation of charge carrier density. However, the issue of long-term stability at room temperature still remains unsolved even after construction of a composite structure. To address this issue, the surface and hetero-junction of the GO/TiO2 composite were engineered via a UV process. A photocatalytic effect of TiO2 induced the reduction of the GO phase in the composite solution. The comparison of gas-sensing properties before and after the UV process clearly showed the transition from n-type to p-type gas-sensing behavior toward reducing gases. This transition revealed that the dominant sensing material is GO, and TiO2 enhanced the gas reaction by providing more reactive sites. With a UV-treated composite sensor, the function of identifying target gas was maintained over a one-month period, showing strong resistance to humidity.

14.
PLoS Med ; 14(7): e1002348, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28742798

RESUMEN

BACKGROUND: After traumatic brain injury (TBI), the ability of cerebral vessels to appropriately react to changes in arterial blood pressure (pressure reactivity) is impaired, leaving patients vulnerable to cerebral hypo- or hyperperfusion. Although, the traditional pressure reactivity index (PRx) has demonstrated that impaired pressure reactivity is associated with poor patient outcome, PRx is sometimes erratic and may not be reliable in various clinical circumstances. Here, we introduce a more robust transform-based wavelet pressure reactivity index (wPRx) and compare its performance with the widely used traditional PRx across 3 areas: its stability and reliability in time, its ability to give an optimal cerebral perfusion pressure (CPPopt) recommendation, and its relationship with patient outcome. METHODS AND FINDINGS: Five hundred and fifteen patients with TBI admitted in Addenbrooke's Hospital, United Kingdom (March 23rd, 2003 through December 9th, 2014), with continuous monitoring of arterial blood pressure (ABP) and intracranial pressure (ICP), were retrospectively analyzed to calculate the traditional PRx and a novel wavelet transform-based wPRx. wPRx was calculated by taking the cosine of the wavelet transform phase-shift between ABP and ICP. A time trend of CPPopt was calculated using an automated curve-fitting method that determined the cerebral perfusion pressure (CPP) at which the pressure reactivity (PRx or wPRx) was most efficient (CPPopt_PRx and CPPopt_wPRx, respectively). There was a significantly positive relationship between PRx and wPRx (r = 0.73), and wavelet wPRx was more reliable in time (ratio of between-hour variance to total variance, wPRx 0.957 ± 0.0032 versus PRx and 0.949 ± 0.047 for PRx, p = 0.002). The 2-hour interval standard deviation of wPRx (0.19 ± 0.07) was smaller than that of PRx (0.30 ± 0.13, p < 0.001). wPRx performed better in distinguishing between mortality and survival (the area under the receiver operating characteristic [ROC] curve [AUROC] for wPRx was 0.73 versus 0.66 for PRx, p = 0.003). The mean difference between the patients' CPP and their CPPopt was related to outcome for both calculation methods. There was a good relationship between the 2 CPPopts (r = 0.814, p < 0.001). CPPopt_wPRx was more stable than CPPopt_PRx (within patient standard deviation 7.05 ± 3.78 versus 8.45 ± 2.90; p < 0.001). Key limitations include that this study is a retrospective analysis and only compared wPRx with PRx in the cohort of patients with TBI. Prior prospective validation is required to better assess clinical utility of this approach. CONCLUSIONS: wPRx offers several advantages to the traditional PRx: it is more stable in time, it yields a more consistent CPPopt recommendation, and, importantly, it has a stronger relationship with patient outcome. The clinical utility of wPRx should be explored in prospective studies of critically injured neurological patients.


Asunto(s)
Determinación de la Presión Sanguínea/métodos , Lesiones Traumáticas del Encéfalo/diagnóstico , Presión Intracraneal , Monitoreo Fisiológico/métodos , Análisis de Ondículas , Adulto , Determinación de la Presión Sanguínea/instrumentación , Inglaterra , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Adulto Joven
15.
Neurocrit Care ; 27(1): 103-107, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27822739

RESUMEN

BACKGROUND: Many demographic and physiological variables have been associated with TBI outcomes. However, with small sample sizes, making spurious inferences is possible. This paper explores the effect of sample sizes on statistical relationships between patient variables (both physiological and demographic) and outcome. METHODS: Data from head-injured patients with monitored arterial blood pressure, intracranial pressure (ICP) and outcome assessed at 6 months were included in this retrospective analysis. A univariate logistic regression analysis was performed to obtain the odds ratio for unfavorable outcome. Three different dichotomizations between favorable and unfavorable outcomes were considered. A bootstrap method was implemented to estimate the minimum sample sizes needed to obtain reliable association between physiological and demographic variables with outcome. RESULTS: In a univariate analysis with dichotomized outcome, samples sizes should be generally larger than 100 for reproducible results. Pressure reactivity index, ICP, and ICP slow waves offered the strongest relationship with outcome. Relatively small sample sizes may overestimate effect sizes or even produce conflicting results. CONCLUSION: Low power tests, generally achieved with small sample sizes, may produce misleading conclusions, especially when they are based only on p values and the dichotomized criteria of rejecting/not-rejecting the null hypothesis. We recommend reporting confidence intervals and effect sizes in a more complete and contextualized data analysis.


Asunto(s)
Lesiones Traumáticas del Encéfalo/fisiopatología , Lesiones Traumáticas del Encéfalo/terapia , Interpretación Estadística de Datos , Monitorización Hemodinámica/estadística & datos numéricos , Presión Intracraneal/fisiología , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Tamaño de la Muestra , Presión Arterial/fisiología , Humanos , Estudios Retrospectivos
16.
Bioprocess Biosyst Eng ; 40(7): 1049-1056, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28432429

RESUMEN

The improvement in the production of recombinant proteins has been linked in a number of small molecules such as carboxylic acids to the inhibition of histone deacetylase, leading to increased transcription of genes. However, carboxylic acids such as pentanoic acid and butanoic acid have been shown to promote an apoptotic response in Chinese hamster ovary (CHO) cell culture. Supplementation of cultures with antioxidants has shown the ability to reduce the apoptotic response of carboxylic acid supplementation, leading to increased therapeutic protein production. In this study, we showed that pentanoic acid reduced the number of cells entering early apoptosis relative to butanoic acid by 15.4%. Additionally, supplementation of butanoic acid- and pentanoic acid-treated cultures with N-acetyl cysteine (NAC) reduced the population of cells entering early apoptosis by 5.3 and 10.0%, respectively, while increasing productivity by 19.5% in the presence of pentanoic acid and NAC. Conversely, a decrease of 5.7% in production was observed in response to combined butanoic acid and N-acetyl cysteine treatment. The results presented herein provide evidence that a culture supplementation method is critical for optimization of biopharmaceutical manufacturing processes.


Asunto(s)
Proteínas Recombinantes/metabolismo , Acetilcisteína , Animales , Antioxidantes , Células CHO , Cricetinae , Cricetulus
17.
Acta Neurochir Suppl ; 122: 157-9, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27165898

RESUMEN

Hydrocephalus and idiopathic intracranial hypertension (IIH) are neuropathies associated with disturbed cerebrospinal fluid dynamics. Several finite element (FE) brain models were suggested to simulate the pathological changes in hydrocephalus, but with overly simplified assumptions regarding the properties of the brain parenchyma. This study proposes a two-dimensional FE brain model, capable of simulating both hydrocephalus and IIH by incorporating poro-hyperelasticity of the brain and detailed structural information (i.e., sulci).


Asunto(s)
Edema Encefálico/fisiopatología , Hidrocefalia/fisiopatología , Seudotumor Cerebral/fisiopatología , Edema Encefálico/etiología , Simulación por Computador , Análisis de Elementos Finitos , Humanos , Hidrocefalia/complicaciones , Modelos Neurológicos , Seudotumor Cerebral/complicaciones
18.
Acta Neurochir (Wien) ; 157(4): 633-8, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25646851

RESUMEN

BACKGROUND: The dynamic relationship between pulse waveform of intracranial pressure (ICP) and transcranial Doppler (TCD) cerebral blood flow velocity (CBFV) may contain information about cerebrospinal compliance. This study investigated the possibility by focusing on the phase shift between fundamental harmonics of CBFV and ICP. METHODS: Thirty-seven normal pressure hydrocephalus patients (20 men, mean age 58) underwent the cerebrospinal fluid (CSF) infusion tests. The infusion was performed via pre-implanted Ommaya reservoir. The TCD FV was recorded in the middle cerebral artery. Resulting continuous ICP and pressure-volume (PV) signals were analyzed by ICM+ software. RESULTS: In initial stage of the CSF infusion, the phase shift was negative (median value = -11°, range = +60 to -117). There was significant inverse association of phase shift with brain elasticity (R = -0.51; p = 0.0009). In all tests, phase shift consistently decreased during gradual elevation of ICP (p = 0.00001). Magnitude of decrease in phase shift was inversely related to the peak-to-peak amplitude of ICP pulse waveform at a baseline (R = -0.51; p = 0.001). CONCLUSIONS: Phase shift between fundamental harmonics of ICP and TCD waveforms decreases during elevation of ICP. This is caused by an increase of time delay between systolic peak of flow velocity wave and ICP pulse.


Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Circulación Cerebrovascular/fisiología , Hidrocéfalo Normotenso/fisiopatología , Presión Intracraneal/fisiología , Adulto , Anciano , Anciano de 80 o más Años , Presión Sanguínea/fisiología , Encéfalo/irrigación sanguínea , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad
19.
Anal Chem ; 86(11): 5330-7, 2014 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-24773579

RESUMEN

Despite significant improvement in separation efficiency using nanostructure-based platforms, the mechanism underlying the high efficiency of rare cell capture remains elusive. Here we report on the first mechanistic study by developing highly controlled nanostructures to investigate cell surface nanomorphology to better understand the cellular response of CD4(+) T-lymphocytes in contact with nanostructured surfaces and to elucidate key mechanisms for enhancing separation efficiency. Our results showed that actin-rich filopodia protruded from T-cells in the early stage of cell capture (<20 min), demonstrate the different morphologies in response to various quartz nanopillar (QNP) arrays functionalized with streptavidin and the generation of sufficient adhesion sites for rendering more stable binding through three-dimensional local nanotopographic interactions between filopodia-QNPs and cell-substrate, leading to synergistic effects for enhancing cell-capture efficiency. This responsive mechanism of T-cells on nanotopographic templates provides new insights to understand the enhanced cell-capture efficiency and specificity from the primary cell suspension on nanostructured substrates.


Asunto(s)
Linfocitos T CD4-Positivos/ultraestructura , Seudópodos/ultraestructura , Animales , Linfocitos T CD4-Positivos/química , Proteínas de la Membrana/química , Ratones , Ratones Endogámicos C57BL , Nanoestructuras , Seudópodos/química , Cuarzo , Bazo/citología
20.
BMC Med ; 12: 186, 2014 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-25339549

RESUMEN

BACKGROUND: The purpose of this study was to identify whether the distribution of Hounsfield Unit (HU) values across the intracranial area in computed tomography (CT) images can be used as an effective diagnostic tool for determining the severity of cerebral edema in pediatric traumatic brain injury (TBI) patients. METHODS: CT images, medical records and radiology reports on 70 pediatric patients were collected. Based on radiology reports and the Marshall classification, the patients were grouped as mild edema patients (n=37) or severe edema patients (n=33). Automated quantitative analysis using unenhanced CT images was applied to eliminate artifacts and identify the difference in HU value distribution across the intracranial area between these groups. RESULTS: The proportion of pixels with HU=17 to 24 was highly correlated with the existence of severe cerebral edema (P<0.01). This proportion was also able to differentiate patients who developed delayed cerebral edema from mild TBI patients. A significant difference between deceased patients and surviving patients in terms of the HU distribution came from the proportion of pixels with HU=19 to HU=23 (P<0.01). CONCLUSIONS: The proportion of pixels with an HU value of 17 to 24 in the entire cerebral area of a non-enhanced CT image can be an effective basis for evaluating the severity of cerebral edema. Based on this result, we propose a novel approach for the early detection of severe cerebral edema.


Asunto(s)
Edema Encefálico/diagnóstico por imagen , Lesiones Encefálicas/diagnóstico por imagen , Edema Encefálico/complicaciones , Lesiones Encefálicas/complicaciones , Niño , Preescolar , Diagnóstico Precoz , Femenino , Humanos , Lactante , Puntaje de Gravedad del Traumatismo , Masculino , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
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