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1.
Georgian Med News ; (231): 55-9, 2014 Jun.
Artigo em Russo | MEDLINE | ID: mdl-25020173

RESUMO

UNLABELLED: Currently in the world there is no consensus on the provision of sufficient vitamin D and its optimum serum levels of both healthy children and patients with various pathological conditions. THE OBJECTIVE: investigation of vitamin D sufficiency in children with recurrent bronchitis (RB), living in Zaporozhye, by examining of 25(OH)D and parathormone serum level. The study involved 120 children aged 4 to 10 years, divided into 2 groups (60 children each): 1) children, occasionally ill with acute respiratory infections, 2) children with RB. Investigation of serum 25(OH)D was conducted between November and February. Decrease of vitamin D3 below 30 ng/ml in serum was observed in 85% (р<0,05) patients with RB (insufficiency), below 20 ng/ml - in 15% (deficit). The children aged 4-10 years with RB, who living in Zaporozhye, have decrease of serum 25(OH)D that characterizes their vitamin D3 supply as insufficient.


Assuntos
Bronquite Crônica/fisiopatologia , Deficiência de Vitamina D/patologia , Vitamina D/sangue , Bronquite Crônica/sangue , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Caracteres Sexuais , Vitamina D/metabolismo , Deficiência de Vitamina D/sangue
2.
Nanotechnology ; 23(24): 245705, 2012 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-22641388

RESUMO

Rapid phenotype characterization and identification of cultured cells, which is needed for progress in tissue engineering and drug testing, requires an experimental technique that measures physical properties of cells with sub-micron resolution. Recently, band excitation piezoresponse force microscopy (BEPFM) has been proven useful for recognition and imaging of bacteria of different types in pure water. Here, the BEPFM method is performed for the first time on physiologically relevant electrolyte media, such as Dulbecco's phosphate-buffered saline (DPBS) and Dulbecco's modified Eagle's medium (DMEM). Distinct electromechanical responses for Micrococcus lysodeikticus (Gram-positive) and Pseudomonas fluorescens (Gram-negative) bacteria in DPBS are demonstrated. The results suggest that mechanical properties of the outer surface coating each bacterium, as well as the electrical double layer around them, are responsible for the BEPFM image formation mechanism in electrolyte media.


Assuntos
Bactérias/química , Bactérias/citologia , Técnicas de Tipagem Bacteriana/métodos , Fenômenos Biomecânicos , Meios de Cultura/química , Elasticidade , Eletrólitos , Micrococcus , Microscopia , Fenótipo , Polilisina , Pseudomonas fluorescens/química , Pseudomonas fluorescens/citologia , Água/química
3.
Nanotechnology ; 22(50): 505103, 2011 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-22107797

RESUMO

The objective of this paper was to study the effect of antibody-directed targeting of S. aureus by comparing the activities of lysostaphin conjugated to biodegradable polylactide nanoparticles (NPs) in the presence and in the absence of co-immobilized anti-S. aureus antibody. Lysostaphin-antibody-NP conjugates were synthesized through physical adsorption at different enzyme:antibody:NP ratios. The synthesized enzyme-NP conjugates were characterized by means of dynamic light scattering and zeta potential analysis, and the total protein binding yield on the NPs was characterized using Alexa Fluor 350 and 594 dyes for the S. aureus antibody and lysostaphin respectively. We observed enhanced antimicrobial activity for both enzyme-coated and enzyme-antibody-coated NPs for lysostaphin coatings corresponding to ∼ 40% of the initial monolayer and higher compared to the free enzyme case (p < 0.05). At the highest antibody coating concentration, bacterial lysis rates for antibody-coated samples were significantly higher than for lysostaphin-coated samples lacking the antibody (p < 0.05). Such enzyme-NP conjugates thus have the potential for becoming novel therapeutic agents for treating antibiotic-resistant S. aureus infections.


Assuntos
Antibacterianos/farmacologia , Anticorpos Antibacterianos/farmacologia , Lisostafina/química , Lisostafina/farmacologia , Nanopartículas/química , Poliésteres/química , Staphylococcus aureus/efeitos dos fármacos , Adsorção , Antibacterianos/química , Anticorpos Antibacterianos/química , Anticorpos Imobilizados/química , Anticorpos Imobilizados/farmacologia , Cinética , Luz , Testes de Sensibilidade Microbiana , Espalhamento de Radiação
4.
Nanotechnology ; 21(26): 265103, 2010 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-20534889

RESUMO

Hyperlipidemia, a condition associated with atherosclerosis, can develop because of the lack of low density lipoprotein (LDL) receptors in hepatocytes. Since injected polymeric nanoparticles are quickly taken up by the liver Kupffer cells, we hypothesize that it is possible to enhance LDL delivery to the liver through the use of LDL-absorbing nanoparticles. Here, we demonstrate the feasibility of the proposed approach in vitro. We used biodegradable and biocompatible polylactide nanoparticles (approximately 100 nm in diameter) with covalently attached apolipoprotein B100 antibody to adsorb LDLs at physiologically relevant concentrations. We showed that up to sixfold decreases of LDL levels can be achieved in vitro upon treatment of LDL suspensions (500 mg dl( - 1)) with anti-apoB100-nanoparticle conjugates. The study of the uptake of the antibody-nanoparticle-LDL complexes by cells was performed using a mouse macrophage cell line (RAW 264.7) as a model for liver Kupffer cells. We found that macrophages can quickly take up antibody-nanoparticle-LDL complexes and digest them within 24 h. No evidence of cytotoxicity was observed for the experimental conditions used in this study.


Assuntos
Anticorpos/uso terapêutico , Hiperlipidemias/terapia , Lipoproteínas LDL/uso terapêutico , Nanopartículas/uso terapêutico , Animais , Apolipoproteína B-100/imunologia , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Luz , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/ultraestrutura , Camundongos , Microscopia de Força Atômica , Microscopia Confocal , Microscopia de Fluorescência , Nanopartículas/ultraestrutura , Tamanho da Partícula , Poliésteres/farmacologia , Espalhamento de Radiação , Fatores de Tempo , Titulometria
5.
Nanotechnology ; 20(40): 405708, 2009 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-19752493

RESUMO

Functional recognition imaging in scanning probe microscopy (SPM) using artificial neural network identification is demonstrated. This approach utilizes statistical analysis of complex SPM responses at a single spatial location to identify the target behavior, which is reminiscent of associative thinking in the human brain, obviating the need for analytical models. We demonstrate, as an example of recognition imaging, rapid identification of cellular organisms using the difference in electromechanical activity over a broad frequency range. Single-pixel identification of model Micrococcus lysodeikticus and Pseudomonas fluorescens bacteria is achieved, demonstrating the viability of the method.


Assuntos
Redes Neurais de Computação , Microscopia de Força Atômica , Microscopia de Varredura por Sonda , Modelos Teóricos , Análise de Componente Principal
6.
ACS Nano ; 4(2): 689-98, 2010 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-20088597

RESUMO

Harnessing electrical bias-induced mechanical motion on the nanometer and molecular scale is a critical step toward understanding the fundamental mechanisms of redox processes and implementation of molecular electromechanical machines. Probing these phenomena in biomolecular systems requires electromechanical measurements be performed in liquid environments. Here we demonstrate the use of band excitation piezoresponse force microscopy for probing electromechanical coupling in amyloid fibrils. The approaches for separating the elastic and electromechanical contributions based on functional fits and multivariate statistical analysis are presented. We demonstrate that in the bulk of the fibril the electromechanical response is dominated by double-layer effects (consistent with shear piezoelectricity of biomolecules), while a number of electromechanically active hot spots possibly related to structural defects are observed.


Assuntos
Amiloide/química , Eletricidade , Fenômenos Mecânicos , Multimerização Proteica , Estrutura Quaternária de Proteína , Silicatos de Alumínio/química , Animais , Bovinos , Microscopia , Análise Multivariada , Água/química
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