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1.
J Appl Lab Med ; 9(1): 4-13, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37647590

RESUMO

BACKGROUND: The -13910 C/T single nucleotide polymorphism located within the MCM6 gene, an enhancer region located upstream of the lactase-phlorizin hydrolase gene, is associated with lactase persistence/non-persistence traits among the Caucasian population. The performance of a new point-of-care CE-IVD (In Vitro Diagnostic) marked isothermal lab-on-phone lactose intolerance assay, using crude samples, was assessed in comparison with Sanger sequencing using purified DNA, as reference method. METHODS: The study was conducted following a non-probability sampling using direct buccal swab (n = 63) and capillary blood (n = 43) clinical samples from a total of 63 volunteers. A 3 × 3 confusion matrix/contingency table was used to evaluate the performance of the isothermal lab-on-phone lactose intolerance assay. RESULTS: The isothermal lab-on-phone lactose intolerance assay successfully detected the -13910 C/T variant with a limit of detection of 5 cells/assay and demonstrated an overall accuracy of 98.41% (95% CI, 91.47%-99.96%) for buccal swab samples and 100% (95% CI, 91.19%-100%) for capillary blood, taking just 90 min from sample to result, with only 2 min hands-on. CONCLUSIONS: The lab-on-phone pocket-sized assay displayed good performance when using direct buccal swab and capillary blood samples, enabling a low-cost, real-time, and accurate genotyping of the -13910 C/T region for the rapid diagnosis of primary lactose intolerance at point-of-care, which enables a prompt implementation of appropriate diet habits and/or intolerance therapies. To our knowledge, this is the first point-of-care genetic test for lactose intolerance to be made available on the market.


Assuntos
Intolerância à Lactose , Humanos , Intolerância à Lactose/diagnóstico , Intolerância à Lactose/genética , Intolerância à Lactose/epidemiologia , Lactase/genética , Sistemas Automatizados de Assistência Junto ao Leito , Genótipo , Testes Imediatos
2.
Stud Health Technol Inform ; 302: 337-341, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37203674

RESUMO

The MedSecurance project focus on identifying new challenges in cyber security with focus on hardware and software medical devices in the context of emerging healthcare architectures. In addition, the project will review best practice and identify gaps in the guidance, particularly the guidance stipulated by the medical device regulation and directives. Finally, the project will develop comprehensive methodology and tooling for the engineering of trustworthy networks of inter-operating medical devices, that shall have security-for-safety by design, with a strategy for device certification and certifiable dynamic network composition, ensuring that patient safety is safeguarded from malicious cyber actors and technology "accidents".


Assuntos
Certificação , Segurança Computacional , Humanos , Engenharia , Instalações de Saúde , Legislação de Dispositivos Médicos
3.
Int J Infect Dis ; 123: 1-8, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35878801

RESUMO

OBJECTIVES: The performance of a new point-of-care CE-IVD-marked isothermal lab-on-phone COVID-19 assay was assessed in comparison to a gold standard real-time reverse transcriptase-PCR method. METHODS: The study was conducted following a nonprobability sampling of ≥16-year-old volunteers from three different laboratories, using direct mouthwash (N = 24) or nasopharyngeal (N = 191) clinical samples. RESULTS: The assay demonstrated 95.19% sensitivity and 100% specificity for detection of SARS-CoV-2 in direct nasopharyngeal crude samples and 78.95% sensitivity and 100% specificity in direct mouthwash crude samples. It also successfully detected currently predominant SARS-CoV-2 variants of concern (Beta B.1.351, Delta B.1.617.2, and Omicron B.1.1.529) and demonstrated to be inert against potential cross-reactions of other common respiratory pathogens that cause infections that present similar symptoms to COVID-19. CONCLUSION: This lab-on-phone pocket-sized assay relies on an isothermal amplification of SARS-CoV-2's N and E genes, taking just 50 minutes from sample to result, with only 2 minutes of hands-on time. It presents good performance when using direct nasopharyngeal crude samples, enabling a low-cost, real-time, rapid, and accurate identification of SARS-CoV-2 infections at the point of care, which is important for both clinical management and population screening, as a tool to break the chain of transmission of COVID-19 pandemic, especially in low-resources environments.


Assuntos
COVID-19 , SARS-CoV-2 , Adolescente , COVID-19/diagnóstico , Teste para COVID-19 , Humanos , Laboratórios , Técnicas de Diagnóstico Molecular/métodos , Antissépticos Bucais , Técnicas de Amplificação de Ácido Nucleico/métodos , Pandemias , RNA Viral/análise , RNA Viral/genética , DNA Polimerase Dirigida por RNA/genética , SARS-CoV-2/genética , Sensibilidade e Especificidade
4.
Cytokine ; 151: 155806, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35065510

RESUMO

To date, several studies have reported that key cytokines in the inflammatory system have important roles in the pathogenesis of cancer, notably in lung cancer. The aim of this case-control study, conducted for the first time in Moroccan population, was to investigate and to analyze the association of the following inflammatory cytokine genes Interleukin (IL)-6, Interleukin (IL)-8, Interleukin (IL)-10, Interleukin (IL)-17, Tumor Necrosis Factor-Alpha (TNFA), Macrophage migration Inhibitory Factor (MIF) and Signal Transducer and Activator of Transcription 3 (STAT3) with lung cancer risk in our patients. Firstly, the mRNA expression was assessed by a quantitative real time PCR in the peripheral blood of lung cancer patients and healthy subjects. Secondly, polymorphisms in the genes encoding cytokines were assessed in 160 lung cancer patients and 150 healthy controls. Genotyping analysis was performed with a Real-Time polymerase chain reaction using TaqMan® genotyping assays on a 7500 FAST Real-Time PCR System and Restriction Fragment Length PolymorphismPCR. Our results revealed a significant difference in mRNA expression levels of IL-6, IL-8, IL-10, IL-17 and TNFA genes in lung cancer patients compared to healthy subjects (P < 0.05). Among the studied genes, we found a significant association between lung cancer risk in our patients and the following polymorphisms IL-6 (rs1800795, rs1800796), IL-8 (rs4075, rs2227306), IL-17F (rs763780, rs2397084) and MIF (rs755622). In conclusion, the results of our study suggest that IL-6, IL-8, IL-10, IL-17 and MIF cytokine genes may aggravate lung cancer risk in the Moroccan population. However, further investigations are required to confirm our findings.


Assuntos
Neoplasias Pulmonares , Fatores Inibidores da Migração de Macrófagos , Estudos de Casos e Controles , Predisposição Genética para Doença , Humanos , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-17/genética , Interleucina-17/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-8/genética , Interleucina-8/metabolismo , Oxirredutases Intramoleculares/genética , Oxirredutases Intramoleculares/metabolismo , Neoplasias Pulmonares/genética , Fatores Inibidores da Migração de Macrófagos/genética , Fatores Inibidores da Migração de Macrófagos/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
5.
Sci Rep ; 9(1): 12241, 2019 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-31439854

RESUMO

Alzheimer´s Disease (AD) is one of the most common neurodegenerative disorders worldwide. Excess of ß-amyloid (Aß), a peptide with a high propensity to misfold and self-aggregate, is believed to be the major contributor to the observed neuronal degeneration and cognitive decline in AD. Here, we characterize the epitope of a novel anti-Aß monoclonal antibody, the STAB-MAb, which has previously demonstrated picomolar affinities for both monomers (KD = 80 pM) and fibrils (KD = 130 pM) of Aß(1-42) and has shown therapeutic efficacy in preclinical mouse models of AD. Our findings reveal a widespread epitope that embraces several key Aß residues that have been previously described as important in the Aß fibrillation process. Of note, STAB-MAb exhibits a stronger affinity for the N-terminus of Aß and stabilizes an α-helix conformation in the central to N-terminal region of the peptide, in addition to disrupting a characteristic salt-bridge of a hairpin structure present in fibrils. The NMR derived epitope supports the observed results from ThT-monitored fluorescence and electron microscopy experiments, in which STAB-MAb was shown to inhibit the formation of aggregates and promote disruption of pre-formed fibrils. In combination with the published in vitro and in vivo assays, our study highlights STAB-MAb as a rare and versatile antibody with analytical, diagnostic and therapeutic efficacy.


Assuntos
Peptídeos beta-Amiloides/química , Peptídeos beta-Amiloides/imunologia , Anticorpos Monoclonais/imunologia , Doença de Alzheimer/genética , Doença de Alzheimer/imunologia , Motivos de Aminoácidos , Peptídeos beta-Amiloides/genética , Animais , Mapeamento de Epitopos , Humanos , Imageamento por Ressonância Magnética , Camundongos , Conformação Proteica em alfa-Hélice
6.
Neurobiol Aging ; 75: 98-108, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30554086

RESUMO

Type 2 diabetes mellitus (T2DM) increases the risk for Alzheimer's disease (AD). Human AD brains show reduced glucose metabolism as measured by [18F]fluoro-2-deoxy-2-D-glucose positron emission tomography (FDG-PET). Here, we used 14-month-old wild-type (WT) and APPSwe/PS1dE9 (APP/PS1) transgenic mice to investigate how a single dose of intranasal insulin modulates brain glucose metabolism using FDG-PET and affects spatial learning and memory. We also assessed how insulin influences the activity of Akt1 and Akt2 kinases, the expression of glial and neuronal markers, and autophagy in the hippocampus. Intranasal insulin moderately increased glucose metabolism and specifically activated Akt2 and its downstream signaling in the hippocampus of WT, but not APP/PS1 mice. Furthermore, insulin differentially affected the expression of homeostatic microglia markers P2ry12 and Cx3cr1 and autophagy in the hippocampus of WT and APP/PS1 mice. We found no evidence that a single dose of intranasal insulin improves overnight memory. Our results suggest that intranasal insulin exerts diverse effects on Akt2 signaling, autophagy, and the homeostatic status of microglia depending on the degree of AD-related pathology.


Assuntos
Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Hipocampo/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Insulina/metabolismo , Memória/efeitos dos fármacos , Camundongos , Neurônios/metabolismo , Presenilina-1/metabolismo
7.
Nanomedicine ; 14(2): 609-618, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29248676

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disorder related, in part, to the accumulation of amyloid-ß peptide (Aß) and especially the Aß peptide 1-42 (Aß1-42). The aim of this study was to design nanocarriers able to: (i) interact with the Aß1-42 in the blood and promote its elimination through the "sink effect" and (ii) correct the memory defect observed in AD-like transgenic mice. To do so, biodegradable, PEGylated nanoparticles were surface-functionalized with an antibody directed against Aß1-42. Treatment of AD-like transgenic mice with anti-Aß1-42-functionalized nanoparticles led to: (i) complete correction of the memory defect; (ii) significant reduction of the Aß soluble peptide and its oligomer level in the brain and (iii) significant increase of the Aß levels in plasma. This study represents the first example of Aß1-42 monoclonal antibody-decorated nanoparticle-based therapy against AD leading to complete correction of the memory defect in an experimental model of AD.


Assuntos
Doença de Alzheimer/complicações , Peptídeos beta-Amiloides/imunologia , Anticorpos Monoclonais/química , Modelos Animais de Doenças , Transtornos da Memória/terapia , Nanopartículas/administração & dosagem , Polímeros/administração & dosagem , Animais , Anticorpos Monoclonais/imunologia , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Nanopartículas/química , Nanopartículas/metabolismo , Polímeros/química , Polímeros/metabolismo , Recuperação de Função Fisiológica
8.
Biotechnol Rep (Amst) ; 16: 21-25, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29124021

RESUMO

Due to their relevance as disease biomarkers and for diagnostics, screening of single nucleotide polymorphism (SNPs) requires simple and straightforward strategies capable to provide results in medium throughput settings. Suitable approaches relying on isothermal amplification techniques have been evolving to substitute the cumbersome and highly specialized PCR amplification detection schemes. Nonetheless, identification of an individual's genotype still requires sophisticated equipment and laborious methods. Here, we present a low-cost and reliable approach based on the allele specific loop-mediated isothermal amplification (AS-LAMP) coupled to ssDNA functionalized gold nanoparticle (Au-nanoprobe) colorimetric sequence discrimination. The Au-nanoprobe integration allows for the colorimetric detection of AS-LAMP amplification product that can be easily interpreted in less than 15 min. We targeted a clinical relevant SNP responsible for lactose intolerance (-13910C/T dbSNP rs#: 4988235) to demonstrate its proof of concept and full potential of this novel approach.

9.
Biomaterials ; 112: 141-152, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27760398

RESUMO

The accumulation of extracellular amyloid-beta (Aß) and intracellular neurofibrillary tangles (hyper-phosphorylated Tau) in the brain are two major neuropathological hallmarks of Alzheimer's disease (AD). Active and passive immunotherapy may limit cerebral Aß deposition and/or accelerate its clearance. With the aid of a newly characterized monoclonal anti-Aß antibody we constructed immunoPEGliposomes with high avidity for capturing Aß in the periphery. The functionality of these vesicles in modulating Aß uptake by both human brain capillary endothelial hCMEC/D3 cells (suppressing uptake) and THP-1 phagocytes (stimulating uptake) was confirmed in vitro. The multivalent immunoliposomes dramatically reduced circulating and brain levels of Aß1-40, and particularly Aß1-42, in "aged" (16 month-old), but not "adult" (10 month-old) APP/PS1 transgenic mice on repeated intraperitoneal administration. Furthermore, the immunoPEGliposome-mediated reduction in amyloidosis correlated with lower levels of glial fibrillary acidic protein (GFAP) and reactive glia (GFAP-positive cells). This treatment also lowered the ratio of phosphorylated Tau to total Tau. The therapeutic efficacy of immunoliposome treatment was superior to free monoclonal antibody administration (at an equivalent antibody dose). The potential mechanisms and significance of age-dependent immunoliposome therapy in AD is discussed.


Assuntos
Envelhecimento/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Anticorpos Monoclonais/administração & dosagem , Encéfalo/metabolismo , Lipossomos/química , Envelhecimento/patologia , Peptídeos beta-Amiloides/sangue , Animais , Encéfalo/efeitos dos fármacos , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Polietilenoglicóis/química , Resultado do Tratamento
10.
Curr Top Med Chem ; 15(22): 2267-76, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26043735

RESUMO

Three different amyloid targeting ligands, previously shown to exhibit amyloid specific properties, have been used to develop amyloid -targeted nanoliposomes (AT-NLs. For this a MAb against Aß-peptides (Aß-MAb (immobilized on NLs at 0.015 and 0.05 mol %, and two different curcumin-lipid derivatives were attached to the surface of preformed NLs or incorporated in NL membranes during their formation. Following physicochemical characterization, these AT-NLs were studied for their ability to inhibit or delay amyloid peptide aggregation -using the thioflavin-T assay, and for their potential to reverse amyloid-induced (and Zn, or, amyloid + Zn cytotoxicity, on wild type (N2aWT and transformed (N2aAPP neuroblastoma cells, applying the MTT assay. Experimental results reveal that all formulations were found to strongly delay amyloid peptide aggregation (with no significant differences between the different AT-NL types. However, although Aß-MAb-NLs significantly reversed amyloid-induced cytotoxicity in all cases, both curcumin-NL types did not reverse Zn-induced, nor Zn+Aß-induced cytotoxicity in N2aWT cells, suggesting lower activity against synthetic-Aß peptides (compared to endogenous Aß peptides; perhaps due to different affinity towards different (aggregation stages of peptide species (monomers, oligomers, fibrils, etc. Taken into account that the aggregation stage of amyloid species is an important determinant of their toxicity, the importance of the affinity of each AT-NL type towards specific species, is highlighted.


Assuntos
Amiloide/metabolismo , Lipossomos/química , Lipossomos/farmacologia , Nanopartículas/química , Doença de Alzheimer/tratamento farmacológico , Amiloide/antagonistas & inibidores , Peptídeos beta-Amiloides/imunologia , Peptídeos beta-Amiloides/toxicidade , Animais , Anticorpos Monoclonais/química , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Curcumina/administração & dosagem , Curcumina/química , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Ligantes , Lipossomos/administração & dosagem , Camundongos , Nanopartículas/administração & dosagem , Testes de Toxicidade/métodos
11.
Anal Biochem ; 465: 1-5, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25077987

RESUMO

Identification of specific nucleic acid sequences mediated by gold nanoparticles derivatized thiol-modified oligonucleotides (Au-nanoprobes) has been proven to be a useful tool in molecular diagnostics. Here, we demonstrate that, on optimization, detection may be simplified via the use of a single Au-nanoprobe to detect a single nucleotide polymorphism (SNP) in homo- or heterozygote condition. We validated this non-cross-linking approach through the analysis of 20 clinical samples using a single specific Au-nanoprobe for an SNP in the FTO (fat mass and obesity-associated) gene against direct DNA sequencing. Sensitivity, specificity, and limit of detection (LOD) were determined, and statistical differences were calculated by one-way analysis of variance (ANOVA) and a post hoc Tukey's test to ascertain whether there were any differences between Au-nanoprobe genotyped groups. For the first time, we show that the use of a single Au-nanoprobe can detect SNP for each genetic status (wild type, heterozygous, or mutant) with high degrees of sensitivity (87.50%) and specificity (91.67%).


Assuntos
Sondas de DNA/química , Técnicas de Genotipagem/métodos , Ouro/química , Nanopartículas Metálicas/química , Polimorfismo de Nucleotídeo Único , Proteínas/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato , Colorimetria/métodos , Sondas de DNA/genética , Feminino , Humanos , Masculino
12.
Analyst ; 139(19): 4964-73, 2014 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-25084161

RESUMO

We present a proof-of-concept of the application of gold nanotriangles in sequence specific DNA detection, using localized surface plasmon resonance (LSPR) spectroscopy and dark-field optical microscopy. The sensing platform comprises gold nanotriangles immobilized on a glass chip and oligonucleotides as probes. Probe formation and testing complementary and non-complementary targets followed common chip technology protocols. Gold nanotriangles showed a remarkable sensitivity of 468 nm per RIU and allowed detection of 20-mer targets. When the target sequence was part of a 50-mer synthetic DNA oligonucleotide, LSPR shifts as high as 35 nm were observed. Conversely, when the target was present in PCR products of ca. 350 bp, obtained from clinical samples, LSPR shifts larger than 20 nm were observed. Moreover, LSPR shifts were less than ±1 nm for the respective non-complementary targets. These results with gold nanotriangles as sensors are a notable improvement to the LSPR shifts of less than 5 nm usually obtained for spherical gold nanoparticles of comparable sizes. Optimal conditions for the detection of synthetic and PCR product targets using gold nanotriangles and oligonucleotide probes were achieved with low percentages of intercalating thioalkanes; target hybridization at room temperature, 3 hours of incubation, and 2× SSC buffer stringency conditions.


Assuntos
Técnicas Biossensoriais , DNA de Cadeia Simples/análise , Nanoestruturas/química , Ressonância de Plasmônio de Superfície , Ouro/química , Humanos , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Tamanho da Partícula , Reação em Cadeia da Polimerase , Temperatura
13.
Microbiologyopen ; 3(4): 513-30, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25055974

RESUMO

Desulfovibrio gigas is a model organism of sulfate-reducing bacteria of which energy metabolism and stress response have been extensively studied. The complete genomic context of this organism was however, not yet available. The sequencing of the D. gigas genome provides insights into the integrated network of energy conserving complexes and structures present in this bacterium. Comparison with genomes of other Desulfovibrio spp. reveals the presence of two different CRISPR/Cas systems in D. gigas. Phylogenetic analysis using conserved protein sequences (encoded by rpoB and gyrB) indicates two main groups of Desulfovibrio spp, being D. gigas more closely related to D. vulgaris and D. desulfuricans strains. Gene duplications were found such as those encoding fumarate reductase, formate dehydrogenase, and superoxide dismutase. Complexes not yet described within Desulfovibrio genus were identified: Mnh complex, a v-type ATP-synthase as well as genes encoding the MinCDE system that could be responsible for the larger size of D. gigas when compared to other members of the genus. A low number of hydrogenases and the absence of the codh/acs and pfl genes, both present in D. vulgaris strains, indicate that intermediate cycling mechanisms may contribute substantially less to the energy gain in D. gigas compared to other Desulfovibrio spp. This might be compensated by the presence of other unique genomic arrangements of complexes such as the Rnf and the Hdr/Flox, or by the presence of NAD(P)H related complexes, like the Nuo, NfnAB or Mnh.


Assuntos
DNA Bacteriano/química , DNA Bacteriano/genética , Desulfovibrio gigas/genética , Genoma Bacteriano , Análise de Sequência de DNA , Proteínas de Bactérias/genética , Análise por Conglomerados , Sequência Conservada , Variação Genética , Dados de Sequência Molecular , Filogenia
14.
Diabetes Metab Syndr Obes ; 6: 241-5, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23874114

RESUMO

PURPOSE: We evaluated the association between risk of obesity in the Portuguese population and two obesity-related single-nucleotide gene polymorphisms: fat-mass and obesity-associated (FTO) rs9939609 and peroxisome proliferator-activated receptor gamma (PPARG) rs1801282. PATIENTS AND METHODS: A total of 194 Portuguese premenopausal female Caucasians aged between 18 and 50 years (95 with body mass index [BMI] ≥30 g/m(2), 99 controls with BMI 18.5-24.9 kg/m(2)) participated in this study. The association of the single-nucleotide polymorphisms with obesity was determined by odds ratio calculation with 95% confidence intervals. RESULTS: Significant differences in allelic expression of FTO rs9939609 (P<0.05) were found between control and case groups, indicating a 2.5-higher risk for obesity in the presence of both risk alleles when comparing the control group with the entire obese group. A fourfold-higher risk was found for subjects with class III obesity compared to those with classes I and II. No significant differences in BMI were found between the control and case groups for PPARG rs1801282 (P>0.05). CONCLUSION: For the first time, a study involving an adult Portuguese population shows that individuals harboring both risk alleles in the FTO gene locus are at higher risk for obesity, which is in agreement to what has been reported for other European populations.

15.
ACS Nano ; 6(7): 5866-79, 2012 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-22725248

RESUMO

A versatile and efficient functionalization strategy for polymeric nanoparticles (NPs) has been reported and successfully applied to PEGylated, biodegradable poly(alkyl cyanoacrylate) (PACA) nanocarriers. The relevance of this platform was demonstrated in both the fields of cancer and Alzheimer's disease (AD). Prepared by copper-catalyzed azide-alkyne cycloaddition (CuAAC) and subsequent self-assembly in aqueous solution of amphiphilic copolymers, the resulting functionalized polymeric NPs exhibited requisite characteristics for drug delivery purposes: (i) a biodegradable core made of poly(alkyl cyanoacrylate), (ii) a hydrophilic poly(ethylene glycol) (PEG) outer shell leading to colloidal stabilization, (iii) fluorescent properties provided by the covalent linkage of a rhodamine B-based dye to the polymer backbone, and (iv) surface functionalization with biologically active ligands that enabled specific targeting. The construction method is very versatile and was illustrated by the coupling of a small library of ligands (e.g., biotin, curcumin derivatives, and antibody), resulting in high affinity toward (i) murine lung carcinoma (M109) and human breast cancer (MCF7) cell lines, even in a coculture environment with healthy cells and (ii) the ß-amyloid peptide 1-42 (Aß(1-42)), believed to be the most representative and toxic species in AD, both under its monomeric and fibrillar forms. In the case of AD, the ligand-functionalized NPs exhibited higher affinity toward Aß(1-42) species comparatively to other kinds of colloidal systems and led to significant aggregation inhibition and toxicity rescue of Aß(1-42) at low molar ratios.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/terapia , Nanopartículas/uso terapêutico , Neoplasias/diagnóstico , Neoplasias/terapia , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Linhagem Celular Tumoral , Coloides , Cianoacrilatos/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Humanos , Camundongos , Microscopia Confocal , Nanopartículas/química , Nanopartículas/toxicidade , Nanotecnologia , Neoplasias/metabolismo , Fragmentos de Peptídeos/metabolismo , Polímeros/química , Receptores de Fatores de Crescimento/metabolismo , Ressonância de Plasmônio de Superfície
16.
Eur J Pharm Biopharm ; 81(1): 49-56, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22386910

RESUMO

Anti-Aß-MAb (Aß-MAb)-decorated immunoliposomes (LIP) and dually decorated ones (dd-LIP) with OX-26 and Aß-MAb were constructed. In both cases, the biotin-streptavidin ligation method was applied. All LIP types were characterized for size distribution, zeta potential, and integrity during incubation with serum proteins. Uptake and transcytosis of both LIP types and control vesicles by human brain endothelial hCMEC/D3 cells were measured. All LIP types had mean diameters below 150-200 nm and low polydispersity. Aß-MAb-LIP uptake was higher than control PEGylated liposomes, while uptake of dd-LIP was similar to that of OX-26-LIP. Aß-MAb-LIP and dd-LIP uptake increased significantly when cells were pre-incubated with Aß1-42 peptides; OX-26-LIP uptake was not modulated. Transcytosis of Aß-MAb-LIP through monolayers was 2.5 times higher when monolayers were pre-incubated with Aß1-42. Transport of both probes, FITC-dextran and rhodamine-lipid, was equivalent, indicating that Aß-MAb-LIP are transferred intact through the BBB model. The Aß peptide-induced increase in binding (and transport) is regulated by the membrane receptors for Aß1-42 peptides (RAGE), as proven after blocking RAGE by a specific MAb. Aß1-42 peptides did not modulate the barrier tightness and integrity, as determined by transendothelial resistance and Lucifer Yellow permeability. Additionally, hCMEC/D3 cell viability was not affected by Aß peptides or by Aß-MAb-LIP.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Anticorpos Monoclonais/farmacocinética , Células Endoteliais/metabolismo , Fragmentos de Peptídeos/metabolismo , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Transporte Biológico , Proteínas Sanguíneas/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/citologia , Encéfalo/metabolismo , Linhagem Celular , Sobrevivência Celular , Dextranos/farmacocinética , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/farmacocinética , Humanos , Lipossomos , Nanopartículas , Tamanho da Partícula , Permeabilidade , Fosfatidiletanolaminas/farmacocinética , Polietilenoglicóis/química , Rodaminas/farmacocinética , Transcitose
17.
Biomaterials ; 32(23): 5489-97, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21529932

RESUMO

Amyloid ß (Aß) aggregates are considered as possible targets for therapy and/or diagnosis of Alzheimer disease (AD), and nanoparticles functionalized with Aß-specific ligands are considered promising vehicles for imaging probes and therapeutic agents. Herein, we characterized the binding properties of nanoliposomes decorated with an anti-Aß monoclonal antibody (Aß-MAb). The Aß-MAb was obtained in mice by immunization with Aß antigen followed by hybridoma fusion. Surface Plasmon Resonance (SPR) studies confirmed the very high affinity of purified Aß-MAb for both Aß monomers and fibrils (K(D) = 0.08 and 0.13 nm, respectively). The affinity of the biotinylated Aß-MAb, used thereafter for liposome decoration, was lower although still in the low nanomolar range (K(D) = 2.1 and 1.6 nm, respectively). Biotin-streptavidin ligation method was used to decorate nanoliposomes with Aß-MAb, at different densities. IgG-decorated liposomes were generated by the same methodology, as control. Vesicles were monodisperse with mean diameters 124-134 nm and demonstrated good colloidal stability and integrity when incubated with serum proteins. When studied by SPR, Aß-MAb-liposomes, but not IgG-liposomes, markedly bound to Aß monomers and fibrils, immobilized on the chip. K(D) values (calculated on Aß-MAb content) were about 0.5 and 2 nm with liposomes at high and low Aß-MAb density, respectively. Aß-MAb-liposome binding to Aß fibrils was additionally confirmed by ultracentrifugation technique, in which interactions occur in solution under physiological conditions. Moreover, Aß-MAb-liposomes bound amyloid deposits in post-mortem AD brain samples, confirming the potential of these nanoparticles for the diagnosis and therapy of AD.


Assuntos
Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/imunologia , Anticorpos Monoclonais/imunologia , Afinidade de Anticorpos/imunologia , Encéfalo/patologia , Lipossomos , Fragmentos de Peptídeos/imunologia , Placa Amiloide/imunologia , Doença de Alzheimer/patologia , Amiloide/imunologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/química , Biotina/análogos & derivados , Biotina/química , Encéfalo/metabolismo , Humanos , Lipossomos/química , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Placa Amiloide/metabolismo , Polietilenoglicóis/química , Coloração e Rotulagem/métodos , Eletricidade Estática , Ressonância de Plasmônio de Superfície , Ultracentrifugação
18.
Med Mycol ; 47(8): 836-44, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19225976

RESUMO

Abstract We conducted a four-year (2003-2006) retrospective study of yeasts recovered in a hospital laboratory in the centre of Portugal to evaluate the epidemiology of yeast infections. Clinical isolates and data were gathered from 751 patients corresponding to 906 episodes of yeast infection. The isolates were first identified using classical and commercial methods, routinely employed at the hospital laboratory. We then re-identified the same isolates using RFLP of the ITS 5.8S rRNA gene and sequence of the D1/D2 domain of the 26S rRNA gene. Candida parapsilosis isolates were re-identified using the Ban I digestion of the SADH gene. C. albicans was the most frequently isolated of the yeasts found in the analysed specimens, with an overall incidence of 69.6% and then in decreasing order, C. glabrata, C. tropicalis, C. parapsilosis and C. krusei. C. parapsilosis was most frequently recovered from younger patients, decreasing with age, while C. glabrata occurrence increased with age. We found an increased number of cases of fungemia per 100,000 people per year, reaching a maximum of 4.4 during 2006.


Assuntos
Candida/isolamento & purificação , Candidíase/microbiologia , Adolescente , Adulto , Idoso , Candida/classificação , Candida/genética , Candidíase/epidemiologia , Criança , Pré-Escolar , DNA Fúngico/análise , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Portugal/epidemiologia , Estudos Retrospectivos , Fatores de Risco
19.
J Clin Microbiol ; 46(2): 713-20, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18077626

RESUMO

The occurrence of invasive mycoses has progressively increased in recent years. Yeasts of the genus Candida remain the leading etiologic agents of those infections. Early identification of opportunistic yeasts may contribute significantly to improved disease management and the selection of appropriate antifungal therapy. We developed a rapid and reliable molecular identification system for clinically relevant yeasts that makes use of nonspecific primers to amplify a region of the 26S rRNA gene, followed by reverse hybridization of the digoxigenin-labeled products to a panel of species-specific oligonucleotide probes arranged on a nylon membrane macroarray format. DNA amplification was achieved by the recently developed loop-mediated isothermal DNA amplification technology, a promising option for the development of improved laboratory diagnostic kits. The newly developed method was successful in distinguishing among the major clinically relevant yeasts associated with bloodstream infections by using simple, rapid, and cost-effective procedures and equipment.


Assuntos
Candida/isolamento & purificação , Candidíase/diagnóstico , Candidíase/microbiologia , Fungemia/diagnóstico , Fungemia/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Hibridização de Ácido Nucleico/métodos , Candida/genética , Primers do DNA/genética , DNA Fúngico/genética , DNA Ribossômico/genética , Humanos , RNA Ribossômico/genética , Sensibilidade e Especificidade
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