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1.
Arch Microbiol ; 205(6): 238, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37193831

RESUMEN

Kinases can be grouped into 20 families which play a vital role as a regulator of neoplasia, metastasis, and cytokine suppression. Human genome sequencing has discovered more than 500 kinases. Mutations of the kinase itself or the pathway regulated by kinases leads to the progression of diseases such as Alzheimer's, viral infections, and cancers. Cancer chemotherapy has made significant leaps in recent years. The utilization of chemotherapeutic agents for treating cancers has become difficult due to their unpredictable nature and their toxicity toward the host cells. Therefore, targeted therapy as a therapeutic option against cancer-specific cells and toward the signaling pathways is a valuable avenue of research. SARS-CoV-2 is a member of the Betacoronavirus genus that is responsible for causing the COVID pandemic. Kinase family provides a valuable source of biological targets against cancers and for recent COVID infections. Kinases such as tyrosine kinases, Rho kinase, Bruton tyrosine kinase, ABL kinases, and NAK kinases play an important role in the modulation of signaling pathways involved in both cancers and viral infections such as COVID. These kinase inhibitors consist of multiple protein targets such as the viral replication machinery and specific molecules targeting signaling pathways for cancer. Thus, kinase inhibitors can be used for their anti-inflammatory, anti-fibrotic activity along with cytokine suppression in cases of COVID. The main goal of this review is to focus on the pharmacology of kinase inhibitors for cancer and COVID, as well as ideas for future development.


Asunto(s)
COVID-19 , Neoplasias , Humanos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , SARS-CoV-2 , Neoplasias/tratamiento farmacológico , Citocinas
2.
Front Mol Biosci ; 10: 1232109, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37621994

RESUMEN

Nanogels are highly recognized as adaptable drug delivery systems that significantly contribute to improving various therapies and diagnostic examinations for different human diseases. These three-dimensional, hydrophilic cross-linked polymers have the ability to absorb large amounts of water or biological fluids. Due to the growing demand for enhancing current therapies, nanogels have emerged as the next-generation drug delivery system. They effectively address the limitations of conventional drug therapy, such as poor stability, large particle size, and low drug loading efficiency. Nanogels find extensive use in the controlled delivery of therapeutic agents, reducing adverse drug effects and enabling lower therapeutic doses while maintaining enhanced efficacy and patient compliance. They are considered an innovative drug delivery system that highlights the shortcomings of traditional methods. This article covers several topics, including the involvement of nanogels in the nanomedicine sector, their advantages and limitations, ideal properties like biocompatibility, biodegradability, drug loading capacity, particle size, permeability, non-immunological response, and colloidal stability. Additionally, it provides information on nanogel classification, synthesis, drug release mechanisms, and various biological applications. The article also discusses barriers associated with brain targeting and the progress of nanogels as nanocarriers for delivering therapeutic agents to the central nervous system.

3.
Am J Transl Res ; 15(3): 1590-1606, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37056808

RESUMEN

OBJECTIVES: Cancer is one of the most prominent causes of death world wide. Identification of novel cancer biomarkers woud help with cancer diagnosis and possible treatment. METHODS: In this study, we comprehensively studied the diagnostic, prognostic, and therapeutic values of the hepatitis A virus cellular receptor 1 (HAVCR1) gene across multiple cancers from a pan-cancer point of view via a detailed in silico approach. RESULTS: HAVCR1 expression was up-regulated in a variety of malignancies. The up-regulated HAVCR1 was closely related to the poor prognosis in patients with esophageal carcinoma (ESCA), lung adenocarcinoma (LUAD), and stomach adenocarcinoma (STAD). Moreover, DAVID analysis showed that HAVCR1, along with different other associated genes, was involved in numerous cancer-associated signaling pathways across ESCA, STAD, and LUAD. Furthermore, in these cancers, HAVCR1 was also found closely associated with some other parameters such as promoter methylation, tumor purity, level of CD8+ T immune cells, genomic alterations, and chemotherapeutic drugs. CONCLUSION: HAVCR1 was overexpressed in multiple tumors. However, the up-regulated HAVCR1 is a valuable diagnostic and prognostic biomarker as well as a therapeutic target in only ESCA, STAD, and LUAD patients.

4.
Sci Rep ; 13(1): 18449, 2023 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-37891223

RESUMEN

Obesity is a complex disease caused by various factors, and synthetic drugs used to treat it can have side effects. Natural compounds, such as olivetol, could be a promising alternative. Olivetol is a substance found in certain lichen species and has anti-inflammatory and anti-cancer properties. In this study, researchers conducted in-silico molecular docking studies and found that olivetol had significant binding affinity with receptors involved in obesity. They also investigated the effects of olivetol on a diet-induced obese zebrafish model and found that high doses of olivetol reduced excessive fat accumulation and triglyceride and lipid accumulation. The low dose of olivetol showed a significant reduction in liver enzymes' levels. However, the high dose of olivetol resulted in a significant increase in HMG-CoA levels. These results suggest that olivetol may be a promising anti-obesity agent for the treatment of hyperlipidemia-related disorders, but further research is necessary to understand its full effects on the body.


Asunto(s)
Fármacos Antiobesidad , Dieta Alta en Grasa , Animales , Dieta Alta en Grasa/efectos adversos , Pez Cebra , Simulación del Acoplamiento Molecular , Metabolismo de los Lípidos , Obesidad/tratamiento farmacológico , Obesidad/etiología , Obesidad/metabolismo , Fármacos Antiobesidad/farmacología , Fármacos Antiobesidad/uso terapéutico , Fármacos Antiobesidad/metabolismo , Hígado/metabolismo
5.
Front Immunol ; 14: 1216321, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37575261

RESUMEN

Background: Impaired wound healing is the most common and significant complication of Diabetes. While most other complications of Diabetes have better treatment options, diabetic wounds remain a burden as they can cause pain and suffering in patients. Wound closure and repair are orchestrated by a sequence of events aided by the release of pro-inflammatory cytokines, which are dysregulated in cases of Diabetes, making the wound environment unfavorable for healing and delaying the wound healing processes. This concise review provides an overview of the dysregulation of pro-inflammatory cytokines and offers insights into better therapeutic outcomes. Purpose of review: Although many therapeutic approaches have been lined up nowadays to treat Diabetes, there are no proper treatment modalities proposed yet in treating diabetic wounds due to the lack of understanding about the role of inflammatory mediators, especially Pro-inflammatory mediators- Cytokines, in the process of Wound healing which we mainly focus on this review. Recent findings: Although complications of Diabetes mellitus are most reported after years of diagnosis, the most severe critical complication is impaired Wound Healing among Diabetes patients. Even though Trauma, Peripheral Artery Disease, and Peripheral Neuropathy are the leading triggering factors for the development of ulcerations, the most significant issue contributing to the development of complicated cutaneous wounds is wound healing impairment. It may even end up with amputation. Newer therapeutic approaches such as incorporating the additives in the present dressing materials, which include antimicrobial molecules and immunomodulatory cytokines is of better therapeutic value. Summary: The adoption of these technologies and the establishment of novel therapeutic interventions is difficult since there is a gap in terms of a complete understanding of the pathophysiological mechanisms at the cellular and molecular level and the lack of data in terms of the assessment of safety and bioavailability differences in the individuals' patients. The target-specific pro-inflammatory cytokines-based therapies, either by upregulation or downregulation of them, will be helpful in the wound healing process and thereby enhances the Quality of life in patients, which is the goal of drug therapy.


Asunto(s)
Citocinas , Diabetes Mellitus , Humanos , Calidad de Vida , Cicatrización de Heridas/fisiología , Mediadores de Inflamación
6.
Curr Diabetes Rev ; 17(4): 486-495, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33297917

RESUMEN

Conventional delivery of antidiabetic drugs faces many problems like poor absorption, low bioavailability, and drug degradation. Nanoemulsion is a unique drug technology, which is very suitable for the delivery of antidiabetic drugs. In recent years, the flaws of delivering anti-hypoglycaemic drugs have been overcome by choosing nanoemulsion drug technology. They are thermodynamically stable and also provide the therapeutic agent for a longer duration. Generally, nanoemulsions are made up of either oil-in-water or water-in-oil and the size of the droplets is from fifty to thousand nanometer. Surfactants are critical substances that are added in the manufacturing of nanoemulsions. Only the surfactants which are approved for human use can be utilized in the manufacturing of nanoemulsions. Generally, the preparation of emulsions includes mixing of the aqueous phase and organic phase and using surfactant with proper agitation. Nanoemulsions are used for antimicrobial drugs, and they are also used in the prophylaxis of cancer. Reduction in the droplet size may cause variation in the elastic and optical behaviour of nanoemulsions.


Asunto(s)
Sistemas de Liberación de Medicamentos , Hipoglucemiantes , Emulsiones , Humanos , Tensoactivos
7.
Phys Rev Lett ; 105(20): 207205, 2010 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-21231263

RESUMEN

We have studied magnetization of graphene nanocrystals obtained by sonic exfoliation of graphite. No ferromagnetism is detected at any temperature down to 2 K. Neither do we find strong paramagnetism expected due to the massive amount of edge defects. Rather, graphene is strongly diamagnetic, similar to graphite. Our nanocrystals exhibit only a weak paramagnetic contribution noticeable below 50 K. The measurements yield a single species of defects responsible for the paramagnetism, with approximately one magnetic moment per typical graphene crystallite.

8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2018: 2885-2888, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30441004

RESUMEN

Hydrogen peroxide ($\text{H}_{\mathbf {2}} \mathbf {O} _{\mathbf {2}}$) plays a critical role in the regulation of multifarious physiological processes. We developed a sensor containing a mercaptopropionic acid (MPA) monolayer covalently immobilized with Horseradish peroxidase (HRP) enzyme for the electrochemical detection of hydrogen peroxide ($\textbf{H}_{\mathbf {2}} \mathbf {O} _{\mathbf {2}}$). A gold foil substrate was chemically treated with nitric acid and were used as working electrode. Platinum wire and Ag-Ag/Cl were used as counter and reference electrodes, respectively. The acid treated gold electrode with the immobilized enzyme shown to have improved catalytic activity in the reduction of $\textbf{H}_{\mathbf {2}} \mathbf {O} _{\mathbf {2}}$. The steady-state current response increases linearly with $\textbf{H}_{\mathbf {2}} \mathbf {O} _{\mathbf {2}}$ concentration from 10 $\mu \textbf{M}$ to 9 mM with a low detection limit of 60 $\mu \textbf{M}$ and showed a sensitivity of 0.4 mA/ mM cm$^{\mathbf {2}}$. This electrochemical sensor is demonstrated to be highly selective and sensitive in the presence of interfering analytes. The improved activity and simple preparation method of the electrode makes the MPAHRP modified gold electrode promising for being developed as an attractive robust material for electrochemical $\textbf{H}_{\mathbf {2}} \mathbf {O} _{\mathbf {2}}$ sensing.


Asunto(s)
Técnicas Biosensibles , Oro , Electrodos , Enzimas Inmovilizadas , Peroxidasa de Rábano Silvestre , Peróxido de Hidrógeno
9.
Sci Rep ; 8(1): 16351, 2018 11 05.
Artículo en Inglés | MEDLINE | ID: mdl-30397324

RESUMEN

A hybrid biofuel cell (HBFC) is explored as a low-cost alternative to abiotic and enzymatic biofuel cells. Here the HBFC provides an enzymeless approach for the fabrication of the anodic electrode while employing an enzymatic approach for the fabrication of the cathodic electrode to develop energy harvesting platform to power bioelectronic devices. The anode employed 250 µm braided gold wire modified with colloidal platinum (Au-co-Pt) and bilirubin oxidase (BODx) modified gold coated Buckypaper (BP-Au-BODx) cathode. The functionalization of the gold coated multi-walled carbon nanotube (MWCNT) structures of the BP electrodes is achieved by 3-mercaptopropionic acid surface modification to possess negatively charged carboxylic groups and subsequently followed by EDC/Sulfo-NHS (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-Hydroxysulfosuccinimide) crosslinking with BODx. The integration of the BODx and gold coated MWCNTs is evaluated for bioelectrocatalytic activity. The Au-co-Pt and BP-Au-BODx exhibited excellent electrocatalytic activity towards glucose oxidation with a linear dynamic range up to 20 mM glucose and molecular oxygen reduction, respectively. The HBFC demonstrated excellent performance with the largest open circuit voltages of 0.735 V and power density of 46.31 µW/cm2 in 3 mM glucose. In addition, the HBFC operating on 3 mM glucose exhibited excellent uninterrupted operational stability while continuously powering a small electronic device. These results provide great opportunities for implementing this simple but efficient HBFC to harvest the biochemical energy of target fuel(s) in diverse medical and environmental applications.


Asunto(s)
Fuentes de Energía Bioeléctrica , Oro/química , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/metabolismo , Platino (Metal)/química , Biocatálisis , Fuentes de Energía Bioeléctrica/economía , Coloides , Costos y Análisis de Costo , Electroquímica , Electrodos , Glucosa/química , Oxígeno/química
10.
Oral Maxillofac Surg ; 21(3): 295-299, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28547078

RESUMEN

AIM: The aim of this study is to assess the efficacy of 4% articaine with 1:100,000 adrenaline given as buccal and lingual infiltration in adult patients undergoing erupted mandibular first and second molar teeth extraction versus inferior alveolar nerve block technique using 2% lignocaine with 1:80,000 adrenaline. MATERIALS AND METHODS: A total of 100 patients undergoing extraction of mandibular posterior teeth were divided into two equally matched groups for the study, out of which 50 patients were given 4% articaine with 1:100,000 adrenaline as buccal and lingual infiltration and 50 patients were given 2% lignocaine with 1:80,000 adrenaline using classic direct inferior alveolar nerve block with lingual and buccal nerve block. Efficacy of anesthesia was determined using a numeric analog scale (NAS) ranging from 0 indicating no pain to 10 indicating the worst pain imaginable. The NAS was taken by a different operator to avoid bias. RESULTS: The pain scores in both groups were analyzed using the Mann-Whitney U test, and a p value of 0.338 was obtained which is not statistically significant. Hence, no significant difference in the pain score was established between both groups. The adverse effects of both the local anesthetics if any were noted. CONCLUSION: From this study, we concluded that the use of 4% articaine with 1:100,000 adrenaline is as effective as inferior alveolar nerve block with lignocaine but without the risk of attendant adverse effects of inferior alveolar nerve block technique.


Asunto(s)
Anestesia Local/normas , Carticaína/farmacología , Lidocaína , Nervio Mandibular/efectos de los fármacos , Diente Molar/cirugía , Bloqueo Nervioso/normas , Extracción Dental/métodos , Adulto , Anestesia Local/efectos adversos , Anestésicos Locales/farmacología , Epinefrina , Femenino , Humanos , Masculino , Mandíbula/cirugía , Bloqueo Nervioso/efectos adversos , Dimensión del Dolor , Resultado del Tratamiento
11.
Neuroscience ; 143(3): 703-16, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17027168

RESUMEN

Brief hypoxia differentially regulates the activities of Ca(2+)-activated K(+) channels (K(Ca)) in a variety of cell types. We investigated the effects of hypoxia (<2% O(2)) on K(Ca) channel currents and on the activities of cytochrome P450 2C11 epoxygenase (CYP epoxygenase) in cultured rat hippocampal astrocytes. Exposure of astrocytes to hypoxia enhanced macroscopic outward K(Ca) current, increased the open state probability (NPo) of 71 pS and 161 pS single-channel K(Ca) currents in cell-attached patches, but failed to increase the NPo of both the 71 pS and 161 pS K(Ca) channel currents recorded from excised inside-out patches. The hypoxia-induced enhancement of macroscopic K(Ca) current was attenuated by pretreatment with tetraethylammonium (TEA, 1 mM) or during recording using low-Ca(2+) external bath solution. Exposure of astrocytes to hypoxia was associated with generation of superoxide as detected by staining of cells with the intracellular superoxide detection probe hydroethidine (HE), attenuation of the hypoxia-induced activation of unitary K(Ca) channel currents by superoxide dismutation with tempol, and as quantitated by high-pressure liquid chromatography/fluorescence assay using HE as a probe. In cultured astrocytes in which endogenous CYP epoxygenase activity has been inhibited with either miconazole or N-methylsulfonyl-6-(2-propargyloxyphenyl) hexanamide (MSPPOH) hypoxia failed to increase the NPo of both the 71 pS and 161 pS K(Ca) currents and generation of superoxide. Hypoxia increased the level of P450 epoxygenase protein and production of epoxyeicosatrienoic acids (EETs) from cultured astrocytes, as determined by immunohistochemical staining and LC/MS analysis, respectively. Exogenous 11,12-EET increased the NPo of both the 71 pS and 161 pS K(Ca) single-channel currents only in cell-attached but not in excised inside-out patches of cultured astrocytes. These findings indicate that hypoxia enhances the activities of two types of unitary K(Ca) currents in astrocytes by a mechanism that appears to involve CYP epoxygenase-dependent generation of superoxide and increased production or release of EETs.


Asunto(s)
Astrocitos/efectos de los fármacos , Cicloparafinas/metabolismo , Hipocampo/citología , Canales de Potasio Calcio-Activados/fisiología , Animales , Animales Recién Nacidos , Astrocitos/fisiología , Western Blotting/métodos , Bloqueadores de los Canales de Calcio/farmacología , Hipoxia de la Célula/efectos de los fármacos , Hipoxia de la Célula/fisiología , Células Cultivadas , Cromatografía Líquida de Alta Presión/métodos , Cicloparafinas/farmacología , Interacciones Farmacológicas , Estimulación Eléctrica/métodos , Inhibidores Enzimáticos/farmacología , Técnica del Anticuerpo Fluorescente/métodos , Proteína Ácida Fibrilar de la Glía/metabolismo , Indoles/farmacología , Potenciales de la Membrana/efectos de los fármacos , Potenciales de la Membrana/fisiología , Potenciales de la Membrana/efectos de la radiación , Técnicas de Placa-Clamp/métodos , Ratas , Especies Reactivas de Oxígeno/metabolismo , Superóxidos/metabolismo
12.
Biosens Bioelectron ; 80: 442-449, 2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-26874112

RESUMEN

Bacillus anthracis, the causative agent of anthrax, is a well known bioterrorism agent. The determination of surface array protein (Sap), a unique biomarker for B. anthracis can offer an opportunity for specific detection of B. anthracis in culture broth. In this study, we designed a new catalytic bionanolabel and fabricated a novel electrochemical immunosensor for ultrasensitive detection of B. anthracis Sap antigen. Bimetallic gold-palladium nanoparticles were in-situ grown on poly (diallyldimethylammonium chloride) functionalized boron nitride nanosheets (Au-Pd NPs@BNNSs) and conjugated with the mouse anti-B. anthracis Sap antibodies (Ab2); named Au-Pd NPs@BNNSs/Ab2. The resulting Au-Pd NPs@BNNSs/Ab2 bionanolabel demonstrated high catalytic activity towards reduction of 4-nitrophenol. The sensitivity of the electrochemical immunosensor along with redox cycling of 4-aminophenol to 4-quinoneimine was improved to a great extent. Under optimal conditions, the proposed immunosensor exhibited a wide working range from 5 pg/mL to 100 ng/mL with a minimum detection limit of 1 pg/mL B. anthracis Sap antigen. The practical applicability of the immunosensor was demonstrated by specific detection of Sap secreted by the B. anthracis in culture broth just after 1h of growth. These labels open a new direction for the ultrasensitive detection of different biological warfare agents and their markers in different matrices.


Asunto(s)
Carbunco/diagnóstico , Bacillus anthracis/aislamiento & purificación , Técnicas Biosensibles , Glicoproteínas de Membrana/aislamiento & purificación , Animales , Carbunco/microbiología , Anticuerpos Inmovilizados/química , Bacillus anthracis/química , Biomarcadores/química , Boro/química , Técnicas Electroquímicas , Oro/química , Inmunoensayo/métodos , Nanopartículas del Metal/química , Ratones , Paladio/química
13.
IET Nanobiotechnol ; 10(2): 39-44, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27074852

RESUMEN

Green chemistry and a central composite design, to evaluate the effect of reducing agent, temperature and pH of the reaction, were employed to produce controlled cuprous oxide (Cu2O) nanoparticles. Response surface method of the ultraviolet-visible spectroscopy is allowed to determine the most relevant factors for the size distribution of the nanoCu2O. X-ray diffraction reflections correspond to a cubic structure, with sizes from 31.9 to 104.3 nm. High-resolution transmission electron microscopy reveals that the different shapes depend strongly on the conditions of the green synthesis.


Asunto(s)
Cobre/química , Tecnología Química Verde/métodos , Nanopartículas del Metal/química , Glucosa/química , Concentración de Iones de Hidrógeno , Nanopartículas del Metal/ultraestructura , Microscopía Electrónica de Transmisión , Oxidación-Reducción , Tamaño de la Partícula , Almidón/química , Temperatura , Difracción de Rayos X
14.
Trends Cardiovasc Med ; 11(1): 38-42, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11413051

RESUMEN

Epoxyeicosatrienoic acids (EETs) are lipid metabolites that are synthesized in vascular endothelial cells. They are released by stimulation of their muscarinic receptors, and induce vaso-relaxation of cerebral blood vessels. In addition, cytochrome P450 epoxygenase enzymes, which catalyze the formation of epoxyeicosatrienoic acids, especially after stimulation by the excitatory neurotransmitter glutamate, are present in astrocytes, an abundant cell type in the brain that extends foot processes onto the cerebral microvessels. Using a modification of an efficient, recently developed, fluorescent assay, we have detected the presence of EETs in endothelial cells cultured from the cortex of rat brains as well as in neonatal astrocytes. We propose that both these cell types provide a dual supply of EETs to increase cerebral blood flow in order to meet systemic as well as localized nutrient demands of cells in the brain.


Asunto(s)
Ácido 8,11,14-Eicosatrienoico/análogos & derivados , Ácido 8,11,14-Eicosatrienoico/metabolismo , Circulación Cerebrovascular/fisiología , Ácido 8,11,14-Eicosatrienoico/química , Animales , Astrocitos/metabolismo , Química Encefálica , Endotelio Vascular/metabolismo , Humanos , Microcirculación/fisiología , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/fisiología , Vasodilatación/fisiología
15.
Trends Cardiovasc Med ; 5(1): 7-14, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-21232232

RESUMEN

The blood vessel wall responds actively to an elevation in transmural pressure. This pressure-induced myogenic response is thought to set the basal level of vascular tone upon which metabolic and neural influences operate in concert to regulate organ blood flow. The cellular mechanisms that mediate the vascular muscle response to mechanical deformation via a changing transmural pressure include membrane depolarization, activation of phospholipase C, and a rise in intracellular [Ca(2+)](i), which appear to be nonadapting-remaining active as long as the pressure stimulus is applied. This brief review addresses some of the cellular events mediating transduction of transmural pressure by the vessel wall. Two possible mechanisms that are responsible for the nonadapting nature of pressure-induced myogenic tone are also explored, namely, formation of a P450 metabolite of arachidonic acid, which acts to buffer activation of K(+) channels as intracellular Ca(2+) rises, and direct activation of Ca(2+) channels by diacylglycerol. Evidence is provided suggesting that activation of phospholipase C is responsible for both the release of the arachidonic acid substrate for P450 enzymes and for the formation of diacylglycerol via its action on membrane-bound phospholipids.

16.
Biosens Bioelectron ; 74: 299-304, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26148674

RESUMEN

Bacillus anthracis is a bioterrorism agent classified by the Centers for Disease Control and Prevention (CDC). Herein, a novel electrochemical immunosensor for the sensitive, specific and easy detection of anthrax protective antigen (PA) toxin in picogram concentration was developed. The immunosensor consists of (i) a Nafion-multiwall carbon nanotubes-bismuth nanocomposite film modified glassy carbon electrodes (BiNPs/Nafion-MWCNTs/GCE) as a sensing platform and (ii) titanium phosphate nanoparticles-cadmium ion-mouse anti-PA antibodies (TiP-Cd(2+)-MαPA antibodies) as signal amplification tags. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), thermogravimmetric analysis (TGA), Fourier transform-infra red spectroscopy (FT-IR), zeta-potential analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to characterize the synthesized TiP nanoparticles and modified electrode surfaces. The immunosensing performance of BiNPs/Nafion-MWCNTs/GCE was evaluated based on sandwich immunoassay protocol. A square wave voltammetry (SWV) scan from -1.2 to -0.3 V in HAc-NaAc buffer solution (pH 4.6) without stripping process was performed to record the electrochemical responses at -0.75 V corresponding to high content of Cd(2+) ions loaded in TiP nanoparticles for the measurement of PA toxin. Under optimal conditions, the currents increased with increasing PA toxin concentrations in spiked human serum samples and showed a linear range from 0.1 ng/ml to 100 ng/ml. The limit of detection of developed immunosensor was found to be 50 pg/ml at S/N=3. The total time of analysis was 35 min.


Asunto(s)
Antígenos Bacterianos/sangre , Toxinas Bacterianas/sangre , Técnicas Biosensibles/métodos , Bismuto/química , Cadmio/química , Nanocompuestos/química , Titanio/química , Técnicas Electroquímicas/métodos , Electrodos , Polímeros de Fluorocarbono/química , Humanos , Límite de Detección , Nanocompuestos/ultraestructura , Nanotubos de Carbono/química
17.
Biosens Bioelectron ; 69: 249-56, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25754919

RESUMEN

In this work, a novel electrochemical immunosensor was developed for the detection of botulinum neurotoxin-E (BoNT/E). This method relied on graphene nanosheets-aryldiazonium salt modified glassy carbon electrodes (GCE) as sensing platform and enzyme induced silver nanoparticles (AgNPs) deposited on gold nanoparticles (AuNPs) as signal amplifier. Herein, a GCE was electrografted with mixed monolayer of phenyl and aminophenyl (Ph-PhNH2/GCE) by diazotization reaction. Further, graphene nanosheets (GNS) were covalently attached on electrode surface (GNS/Ph-PhNH2/GCE). Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were employed to characterize synthesized graphene oxide and modified electrode surfaces. In the sandwich immunoassay format, the sensitivity was amplified using rabbit anti-mouse IgG-alkaline phosphatase (RαMIgG-ALP) functionalized with gold nanoparticles (RαMIgG-ALP/AuNPs). In order to study the immunosensing performance of GNS/Ph-PhNH2/GCE, first the capturing antibody (rabbit-anti BoNT/E antibody) was covalently immobilized via EDC/NHS chemistry. Further, the electrode was sequentially subjected to sample containing spiked BoNT/E, revealing antibody (mouse-anti BoNT/E) followed by RαMIgG-ALP/AuNPs. 3-indoxyl phosphate (3-IP) was used as substrate which finally reduces the silver ions. The deposited AgNPs on electrode surface were determined by linear sweep voltammetry (LSV). The developed electrochemical immunosensor could detect BoNT/E with linear range from 10pg/ml to 10ng/ml with the minimum detection limit of 5.0pg/ml and total analysis time of 65min. In addition, the immunosensor was successfully evaluated against food samples (orange juice and milk).


Asunto(s)
Fosfatasa Alcalina/química , Toxinas Botulínicas/análisis , Conductometría/instrumentación , Grafito/química , Inmunoensayo/instrumentación , Nanopartículas del Metal/química , Electrodos , Diseño de Equipo , Análisis de Falla de Equipo , Oro/química , Nanopartículas del Metal/ultraestructura , Nanoconjugados/química , Nanoconjugados/ultraestructura , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
18.
AJNR Am J Neuroradiol ; 21(4): 679-84, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10782777

RESUMEN

BACKGROUND AND PURPOSE: Before the advent of MR imaging, intraventricular cysts were difficult to diagnose noninvasively. Among the invasive procedures used were contrast ventriculography and CT ventriculography. MR imaging, with its multiplanar imaging capabilities, excellent depiction of tissue contrast, and versatile parameters, is an important tool in the assessment of intraventricular cystic lesions. We investigated the role of three-dimensional constructive interference in steady state (3D-CISS) MR sequences in the evaluation of intraventricular cysticercal cysts. METHODS: The study group comprised 11 patients with intraventricular cysticercal cysts. MR studies included spin-echo (SE) T1-weighted, turbo-SE T2-weighted, and 3D-CISS sequences. All images were obtained on a superconducting 1.5-T MR unit. The routine and 3D-CISS sequences were reviewed and interpreted separately by two neuroradiologists. RESULTS: All patients underwent surgery for excision of intraventricular cysticercal cysts. Eight patients had cysts in the fourth ventricle, two in the lateral ventricle, and one in the third ventricle. SE T1-weighted images showed the cystic wall in nine cases, the scolex in four, and the cystic fluid in two. Turbo-SE T2-weighted images showed the cystic wall and scolex in three and four cases, respectively. The routine sequences did not show the scolex, cystic wall, or cystic fluid together in any of the 11 patients. 3D-CISS images showed the scolex in all 11 patients and the cystic wall and cystic fluid in eight patients each. In seven of the 11 patients, 3D-CISS images showed the scolex, cystic wall, and fluid together. CONCLUSION: The 3D-CISS sequence is more sensitive and specific than routine SE sequences in the diagnosis of intraventricular cysticercal cysts.


Asunto(s)
Ventrículos Cerebrales/patología , Ventrículos Cerebrales/parasitología , Imagen por Resonancia Magnética/métodos , Neurocisticercosis/patología , Neurocisticercosis/parasitología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad
19.
Med Eng Phys ; 22(6): 405-12, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11086251

RESUMEN

Accelerometry represents a noninvasive technique for the assessment of the swallowing mechanism. However, the underlying physiological events that give rise to the acceleration signal are poorly understood. In the present study, the acceleration signal was measured simultaneously during videofluorography examination. Preliminary results revealed that the signal occurred during laryngeal elevation and the magnitude of acceleration correlated well with the laryngeal displacement. Acceleration measurements present a potentially useful noninvasive tool.


Asunto(s)
Aceleración , Trastornos de Deglución/diagnóstico por imagen , Trastornos de Deglución/fisiopatología , Deglución , Fluoroscopía/métodos , Esófago/diagnóstico por imagen , Esófago/fisiopatología , Fluoroscopía/instrumentación , Humanos , Laringe/diagnóstico por imagen , Procesamiento de Señales Asistido por Computador , Grabación en Video
20.
Comput Methods Programs Biomed ; 64(2): 87-99, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11137191

RESUMEN

Biological signals are complex and often require intelligent systems for recognition of characteristic signals. In order to improve the reliability of the recognition or automated diagnostic systems, hybrid fuzzy logic committee neural networks were developed and the system was used for recognition of swallow acceleration signals from artifacts. Two sets of fuzzy logic-committee networks (FCN) each consisting of seven member networks were developed, trained and evaluated. The FCN-I was used to recognize dysphagic swallow from artifacts, and the second committee FCN-II was used to recognize normal swallow from artifacts. Several networks were trained and the best seven were recruited into each committee. Acceleration signals from the throat were bandpass filtered, and several parameters were extracted and fed to the fuzzy logic block of either FCN-I or FCN-II. The fuzzified membership values were fed to the committee of neural networks which provided the signal classification. A majority opinion of the member networks was used to arrive at the final decision. Evaluation results revealed that FCN correctly identified 16 out of 16 artifacts and 31 out of 33 dysphagic swallows. In two cases, the decision was ambiguous due to the lack of a majority opinion. FCN-II correctly identified 24 out of 24 normal swallows, and 28 out of 29 artifacts. In one case, the decision was ambiguous due to the lack of a majority opinion. The present hybrid intelligent system consisting of fuzzy logic and committee networks provides a reliable tool for recognition and classification of acceleration signals due to swallowing.


Asunto(s)
Trastornos de Deglución/diagnóstico , Trastornos de Deglución/fisiopatología , Deglución/fisiología , Diagnóstico por Computador , Redes Neurales de la Computación , Aceleración , Fenómenos Biomecánicos , Estudios de Casos y Controles , Trastornos de Deglución/clasificación , Lógica Difusa , Humanos , Programas Informáticos , Diseño de Software
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