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1.
J Chromatogr A ; 1623: 461151, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505271

RESUMO

Deterministic Lateral Displacement (DLD) is a microfluidic technique where arrays of micropillars within a microchannel deflect particles leading to size-based segregation. We recently demonstrated that applying AC electric fields orthogonal to the fluid flow increases the separation capabilities of these devices with a deflection angle that depends on the electric field magnitude and frequency. Particle deviation occurs in two distinct regimes depending on frequency. At high frequencies particles deviate due to negative dielectrophoresis (DEP). At low frequencies (below 1 kHz) particles oscillate perpendicular to the flow direction due to electrophoresis and are also deflected within the device. Significantly, the threshold electric field magnitude for the low frequency deviation is much lower than for deflection at high frequencies by DEP. In order to characterize the enhanced separation at low frequencies, the induced deviation was compared between the two frequency ranges. For high frequencies, we develop both theoretically and experimentally scaling laws for the dependence of particle deviation on several parameters, namely the amplitude of the applied voltage, particle size and liquid velocity where DEP forces compete with viscous drag. A novel theoretical framework is presented that enables simulation of particle trajectories subjected to DEP forces in DLD devices. Deviation angles predicted by simulations are in very good agreement with experimental data. At low frequencies (below 1 kHz), particles follow the same scaling law, but with much lower voltages. This indicates that electrokinetic phenomena other than DEP play an important role in driving particle behaviour. Experiments show that at low frequencies, particle motion is affected by quadrupolar electrohydrodynamic flows around the insulating pillars of the DLD array. We quantify the difference between the two frequency regimes and show that an electrokinetic model based only on DEP forces is limited to frequencies of 1 kHz and above.


Assuntos
Simulação por Computador , Eletroforese/métodos , Microfluídica/métodos , Eletricidade , Hidrodinâmica , Microesferas , Tamanho da Partícula , Fatores de Tempo
2.
Electrophoresis ; 41(13-14): 1137-1151, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32469436

RESUMO

The material properties of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its proteins are discussed. We review the viral structure, size, rigidity, lipophilicity, isoelectric point, buoyant density and centrifugation conditions, stability against pH, temperature, UV light, gamma radiation, and susceptibility to various chemical agents including solvents and detergents. Possible inactivation, downstream, and formulation conditions are given including suitable buffers and some first ideas for quality-control methods. This information supports vaccine development and discussion with competent authorities during vaccine approval and is certainly related to drug-targeting strategies and hygienics. Several instructive tables are given, including the pI and grand average of hydropathicity (GRAVY) of SARS-CoV-1 and -2 proteins in comparison. SARS-CoV-1 and SARS-CoV-2 are similar in many regards, so information can often be derived. Both are unusually stable, but sensitive at their lipophilic membranes. However, since seemingly small differences can have strong effects, for example, on immunologically relevant epitope settings, unevaluated knowledge transfer from SARS-CoV-1 to SARS-CoV-2 cannot be advised. Published knowledge regarding downstream processes, formulations and quality assuring methods is, as yet, limited. However, standard approaches employed for other viruses and vaccines seem to be feasible including virus inactivation, centrifugation conditions, and the use of adjuvants.


Assuntos
Betacoronavirus/química , Proteínas Virais/química , Vacinas Virais/farmacologia , Animais , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/efeitos da radiação , Desinfetantes/farmacologia , Eletroforese , Temperatura Alta , Humanos , Concentração de Íons de Hidrogênio , Ponto Isoelétrico , Raios Ultravioleta , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/farmacologia , Vacinas Virais/imunologia , Inativação de Vírus/efeitos da radiação
3.
Ecotoxicol Environ Saf ; 197: 110620, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32311615

RESUMO

The aim of this study was to evaluate the ecotoxic effect of high concentration cesium (Cs) exposure on plant root growth and its toxicological mechanism. The radicle of broad bean (Vicia faba) was selected as experimental material. The cytotoxic and genotoxic effects of plants exposed to different Cs levels (0.19-1.5 mM) for 48 h were evaluated using scanning electron microscopy (SEM), X-ray fluorescence (XRF) analysis, single-cell gel electrophoresis (SCGE) and random amplified polymorphic DNA (RAPD) assays. The results showed that radicle elongation decreased clearly after 48 h of exposure treatment with different concentrations of Cs solution. The root cell structure was obviously damaged in the Cs treatment groups (0.19-1.5 mM). At a Cs concentration of 1.5 mM, the percentages of viable non-apoptotic cells, viable apoptotic cells, non-viable apoptotic cells, and non-viable cells were 40.09%, 20.67%, 28.73%, and 10.52%, respectively. SCGE showed DNA damage in radicle cells 48 h after Cs exposure. Compared with the control group, the percentage of tail DNA in Cs exposed group (0.38-1.5 mM) increased by 0.56-1.12 times (P < 0.05). RAPD results showed that the genomic stability of V. faba radicles decreased by 4.44%-15.56%. This study confirmed that high concentration Cs exposure had cytotoxicity and genotoxicity effects on plants.


Assuntos
Césio/toxicidade , Dano ao DNA , Vicia faba/efeitos dos fármacos , Apoptose , Citotoxinas/toxicidade , Eletroforese , Instabilidade Genômica/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Célula Única , Vicia faba/genética
4.
Food Chem ; 321: 126677, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247180

RESUMO

Myosin heavy chain (MHC) isoforms in goat muscles and their possible relationships with meat quality have not been fully elucidated. This study characterized the MHC isoforms in different caprine muscles using sodium dodecyl sulphate glycerol gel electrophoresis (SDS-GGE). The relationships between MHC isoforms, calpain systems and meat quality characteristics of different muscles in goats were examined. Four muscles, namely infraspinatus (IF), longissimus dorsi (LD), psoas major (PM) and supraspinatus (SS) were obtained from ten Boer crossbred bucks (7-10 months old; 26.5 ± 3.5 kg, BW). The percentages of MHC I, MHC IIa and MHC IIx in SS, IF, PM and LD were 47.2, 38.3, 32.1, 11.9; 28.0, 42.1, 33.0, 36.4; and 24.8, 19.6, 34.9 and 51.7, respectively. IF and SS had higher levels of calpastatin, total collagen and insoluble collagen contents than did PM and LD. PM had longer sarcomere length than did other muscles. LD had higher collagen solubility, troponin-T degradation products and glycogen content than did other muscles. These results infer that variable fiber-type composition could account partially for the differences in the physicochemical properties of goat muscles.


Assuntos
Calpaína/metabolismo , Músculo Esquelético/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Animais , Proteínas de Ligação ao Cálcio/metabolismo , Eletroforese , Eletroforese em Gel de Poliacrilamida , Cabras , Carne/análise , Músculo Esquelético/química , Isoformas de Proteínas/metabolismo , Troponina T/metabolismo
5.
J Chromatogr A ; 1620: 460972, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32106967

RESUMO

This paper reports for the first time the coupling of a two-dimensional separation technique known as orthogonal pressurised planar electrochromatography (OPPEC) with on-line UV/VIS detection. It establishes the efficiency characteristic of a planar column used in OPPEC. The studies show that in OPPEC, all separation steps (mixture introduction, separation, and detection) can run successfully as non-separate operation, much like in HPLC, and the planar column has itself good efficiency, ensuring a relatively low plate height value. In its use, some findings of the previously proposed theoretical model concerning optimisation of preparative separation of components with the same electrophoretic mobility are verified - showing that there is a good agreement between theory and experiment. The paper also demonstrates by means of a specific example of separation of a post-reaction mixture obtained after synthesis of valine diastereomers that OPPEC can be a powerful tool used in preparative separation in that it can achieve much higher separation productivity and significantly lower eluent consumption than when using column chromatography techniques.


Assuntos
Cromatografia/métodos , Eletroforese/métodos , Estereoisomerismo
6.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(1): 191-195, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32027275

RESUMO

OBJECTIVE: To analyzed the prognostic value of serum free light chain kappa/lambda ratio detection combined with immunofixation electrophoresis in multiple myeloma (MM) patients. METHODS: 72 patients with MM treated in our hospital from January 2017 to December 2018 were selected. Serum free light chain kappa/lambda ratio (sFLCR) and immune typing were detected respectively. The clinical characteristics and survival time were compared among patients. COX regression was used to analyze the factors influencing prognosis. RESULTS: 38 patients showed high sFLCR, and 34 showed low sFLCR. Compared with the low sFLCR group, the DS stage of patients in high sFLCR group elevated, the levels of ß2-MG and Scrwere increased, and Hb decreased, all the differences were statistically significant (P<0.05). Among 72 patients, there were 40 cases of IgG type (55.56%), 27 cases of IgA type (37.50%) and 5 cases of IgM type (6.94%). Compared with IgG and IgA patients, the serum calcium and creatinine in IgM patients were increased significantly, while Hb decreased significantly (P<0.05). The median survival time was 19.2 months in 21 patients with IgG type and high sFLCR; 24.0 months in 19 patients with IgG type and low sFLCR; 15.0 months in 12 patients with IgA type and high sFLCR; 16.7 months in 15 patients with IgA type and low sFLCR; 6.0 months in 5 patients with IgM type and high sFLCR,respectively. DS stage, M protein typing and sFLCR correlated with prognosis of patients (P<0.05). CONCLUSION: The serum free light chain kappa/lambda ratio combined with immunofixation electrophoresis is valuable for the prognostic evaluation of patients with multiple myeloma.


Assuntos
Mieloma Múltiplo , Eletroforese , Humanos , Cadeias Leves de Imunoglobulina , Cadeias kappa de Imunoglobulina , Cadeias lambda de Imunoglobulina , Prognóstico
7.
Int J Artif Organs ; 43(2): 127-136, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32000591

RESUMO

INTRODUCTION: The aim of this study was to develop a novel decellularization method in order to obtain an ideal scaffold with good biocompatibility. METHODS: The porcine corneas were treated with human serum for 5 days or serum-electrophoresis respectively. The electrophoresis (100 V/cm) was performed in sterilized buffer containing 40-mM tris base, 18-mM glacial acetic acid, and antibiotics for 1 h at 4°C. The properties of artificial corneal scaffolds were characterized by morphological and histological examinations. The biocompatibility and biological safety were examined by subcutaneous implant test and lamellar keratoplasty. RESULTS AND CONCLUSIONS: The transparency and appearance of serum-electrophoresis acellular porcine corneal matrix were better than serum acellular porcine corneal matrix. DNA and α-gal in serum-electrophoresis acellular porcine corneal matrix were more efficiently removed than those in serum acellular porcine corneal matrix (p < 0.05). The subcutaneous and corneal implantation experiments showed serum-electrophoresis acellular porcine corneal matrix had better biocompatibility compared to serum acellular porcine corneal matrix (p < 0.01). This novel serum-electrophoresis decellularization method may be valuable for preparation of xenogenic corneal tissue for clinical application.


Assuntos
Materiais Biocompatíveis , Córnea , Transplante de Córnea/métodos , Engenharia Tecidual/métodos , Tecidos Suporte , Animais , Córnea/citologia , Córnea/cirurgia , Eletroforese/métodos , Humanos , Teste de Materiais/métodos , Suínos
8.
Pharm Res ; 37(2): 22, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897766

RESUMO

PURPOSE: The work aimed to compare quality of a siRNA carrier prepared with chitosan of two different sources having similar degree of deacetylation and molecular weights. Differences were analyzed from thermodynamic characteristics of interactions with siRNA. METHODS: The siRNA carrier (chitosan-coated poly(isobutylcyanoacrylate) nanoparticles) was prepared with home-prepared, CSLab, and commercial, CSCom, chitosans. Chitosan counterion was identified and chitosans CSCommod1 and CSCommod2 were obtained from CSCom exchanging counterion with that found on CSLab. Carrier quality was checked considering the size, zeta potential and siRNA association capacity by gel electrophoresis. Thermodynamic parameters of interactions between siRNA and chitosans in solution or immobilized at the carrier surface were determined by isothermal titration calorimetry (ITC). RESULTS: CSLab and CSCommod2 having a high content of acetate counterion associated better siRNA than CSCom and CSCommod1 which counterion included mainly chloride. ITC measurements indicated that siRNA interactions with chitosan and the siRNA carrier were driven by entropic phenomena including dehydration, but thermodynamic parameters of interactions clearly differed according to the nature of the counterion of chitosan. The influence of chitosan counterions was interpreted considering their different lyotropic character. CONCLUSION: Association of siRNA with our siRNA carrier was influenced by the nature of counterions associated with chitosan. Driven by entropic phenomena including dehydration, interactions were favored by acetate counterion. Although more work would be needed to decipher the influence of the counterion of chitosan during association with siRNA, it was pointed out as a new critical attribute of chitosan to consider while formulating siRNA carrier with this polysaccharide.


Assuntos
Quitosana/química , RNA Interferente Pequeno/química , Calorimetria/métodos , Eletroforese/métodos , Nanopartículas/química , Termodinâmica
9.
J Chromatogr A ; 1610: 460595, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31606156

RESUMO

We discuss several possible phenomena in electrophoretic systems with complexing agents present in the background electrolyte. In our previous work, we extended the linear theory of electromigration with the first-order nonlinear term, which originally applied to acid-base equilibria only, by generalizing it to any fast chemical equilibria. This extension provides us with a fresh insight into the well-established technique of elecktrokinetic chromatography (EKC). We combine mathematical analysis of the generalized model with its solution by means of the new version of our software PeakMaster 6, and experimental data. We re-examine the fundamental equations by Wren and Rowe and Tiselius in the frame of the generalized linear theory of electromigration. Besides, we show that selector concentration can increase inside the interacting-analyte zone due to its complexation with the analyte, which contradicts the generally accepted idea of a consumption of a portion of the selector inside the zone. Next, we focus our discussion on interacting buffers (i.e., buffer constituents that form a complex with the selector). We demonstrate how such side-interaction of the selector with another buffer constituent can influence measuring analyte-selector interactions. Finally, we describe occurrence and mobilities of system peaks in these EKC systems. We investigate systems with fully charged analytes and neutral cyclodextrins as selectors. Although the theory is not limited in terms of the charge and/or the degree of (de)protonation of any constituent, this setup allows us to find analytical solutions to generalized model under approximate, yet realistic, conditions and to demonstrate all important phenomena that may occur in EKC systems. An occurrence of system peaks in a system with fully charged selector is also investigated.


Assuntos
Eletroforese Capilar/métodos , Eletroforese/métodos , Tampões (Química) , Ciclodextrinas/química , Eletrólitos/química , Modelos Lineares , Software , Estereoisomerismo
10.
Talanta ; 208: 120444, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816745

RESUMO

The combination of layered double hydroxides (LDHs), cobalt ferrite (CoFe2O4) and graphene oxide (GO) creates a ternary nanocomposite that can incredibly improve advantages of each compound; this is an impressive way to attain multifunctional materials with attractive properties. In this study, a new high-sensitive electrochemical DNA biosensor was fabricated for the electroanalytical studies of etoposide using a novel ZnAl/layered double hydroxide modified cobalt ferrite-graphene oxide nanocomposite (GO/CoFe2O4/ZnAl-LDH) that was electrophoretically deposited (EPD) on the fluorine tin oxide (FTO) substrate. This DNA biosensor was prepared via electrostatic adsorption of DNA onto the GO/CoFe2O4/ZnAl-LDH/FTO electrode. The electrochemical behavior of electrodes was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). EIS plot obviously demonstrated a rapid electron transport at low frequencies for GO/CoFe2O4/ZnAl-LDH. Differential pulse voltammetry (DPV) and square wave anodic stripping voltammetry (SWASV) were employed for the electrochemical detection of ETO. The results revealed that DNA/GO/CoFe2O4/ZnAl-LDH/FTO bioelectrode had ultrahigh sensitivity to ETO with the detection limit of 0.0010 µM in the linear range of 0.2-10 µM. In addition, the developed biosensor revealed precise reproducibility and excellent stability of about 95% of the initial activity after 6-7 weeks. On the other hand, the present bioelectrode was also capable of discriminating different interferences and was also used to detect etoposide in real samples such as human blood plasma, serum and urine with good recoveries, ranging from 97.0% to 104.0%. The obtained results of the excellent performance of this biosensor could be assigned to the active reaction sites and good electrochemical activity of nanocomposites, hence helping increase the DNA immobilization and accelerate the electron transfer more effectively on the surface electrode.


Assuntos
Técnicas Biossensoriais , DNA/química , Alumínio/química , Animais , Cobalto/química , Técnicas Eletroquímicas , Eletroforese , Compostos Férricos/química , Flúor/química , Grafite/química , Hidróxidos/química , Nanocompostos/química , Salmão , Compostos de Estanho/química , Zinco/química
11.
Ann Anat ; 227: 151412, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31408678

RESUMO

INTRODUCTION: Few data exist on the fiber type composition of the extrinsic finger muscles. The aim of the present study was to describe myosin heavy chain (MyHC) composition of flexor digitorum profundus (FDP), flexor digitorum superficialis (FDS) and extensor digitorum communis (EDC). MyHC composition is relevant for whole muscle contractile performance and several studies on single muscle fibers demonstrated that fibers expressing only slow MyHC-1 develop less specific force than fibers expressing fast MyHCs. Since contraction force of finger extensors is smaller than of finger flexors a hypothesis was posited that the content of MyHC-1 is higher in EDC than in extrinsic finger flexors. METHODS: Autopsy samples of FDP, FDS, and EDC in 27 healthy older men were analyzed and compared with each other and with biceps brachii (BB). MyHC isoforms were quantified on silver-stained 6% SDS-PAGE. Muscle fibers were classified immunohistochemically according to the expression of adult MyHC isoforms and their morphometric parameters were determined. RESULTS: EDC stood out for its higher proportion of slow MyHC-1 (50%) compared to FDP (37%), FDS (38%) and BB (35%) (p<0.001 in all), and its lower proportion of fast MyHC-2x (13%) compared to FDP (26%, p=0.001), FDS (22%, p=0.028) and BB (29%, p<0.001) detected on SDS-PAGE. Immunohistochemically, EDC had a higher area proportion of pure slow type-1 fibers (63%) than FDP (47%, p=0.002), FDS (49%, p=0.007) and BB (47%, p=0.002), and lower area proportion of pure fast type-2x fibers (2%) than FDP (12%, p=0.014), FDS (8%, p=0.256) and BB (14%, p=0.002). All muscles contained a similar area proportion of pure type-2a fibers and hybrid type-2a/2x fibers. CONCLUSIONS: The study results support the hypothesis that the content of MyHC-1 is higher in EDC than in extrinsic finger flexors, which is in agreement with the lower contraction force of finger extensors compared to finger flexors.


Assuntos
Dedos/anatomia & histologia , Músculo Esquelético/química , Cadeias Pesadas de Miosina/análise , Idoso , Idoso de 80 Anos ou mais , Eletroforese , Dedos/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Cadeias Pesadas de Miosina/química
12.
J Cosmet Sci ; 70(6): 291-298, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31829922

RESUMO

The electrokinetic (ζ, zeta) potential was determined for a series of commercial tattoo pigments. A standard experimental method involving the measuring of the level difference formed in a U-shaped tube filled with a solution containing the dye after application of some potential difference was used to find ζ-potential values. All of them were negative and sufficiently large to ensure electrophoretic mobility of the pigment particles in a special gelatin-based electrophoretic bed. Gelatin-based beds, one containing a pigment and the other without the pigment, were set side by side in a microelectrophoretic cell. The application of relatively low potential difference (20-25 V) provoked the migration of the pigment in the gelatin bed without pigment for as much as 10 mm after a 40-minute long electrophoresis. The intensity of the color of the pigment did decrease noticeably. These results seem to indicate the potential applicability of the reported method for the elimination of old and/or unwanted tattoo and of tattoo traces left after previous manipulations.


Assuntos
Tatuagem , Cor , Corantes , Eletroforese
13.
Sensors (Basel) ; 19(23)2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31810237

RESUMO

Dielectrophoresis is an electric force experienced by particles subjected to non-uniform electric fields. Recently, several technologies have been developed focused on the use of dielectrophoretic force (DEP) to manipulate and detect cells. On the other hand, there is no such great development in the field of DEP-based cell discrimination methods. Despite the demand for methods to differentiate biological cell states, most DEP developed methods have been focused on differentiation through geometric parameters. The novelty of the present work relies upon the point that a DEP force cell measurement is used as a discrimination method, capable of detecting heat killed yeast cells from the alive ones. Thermal treatment is used as an example of different biological state of cells. It comes from the fact that biological properties have their reflection in the electric properties of the particle, in this case a yeast cell. To demonstrate such capability of the method, 279 heat-killed cells were measured and compared with alive cells data from the literature. For each cell, six speeds were taken at different points in its trajectory inside a variable non-uniform electric field. The electric parameters in cell wall conductivity, cell membrane conductivity, cell membrane permittivity of the yeast cell from bibliography explains the DEP experimental force measured. Finally, alive and heat-treated cells were distinguished based on that measure. Our results can be explained through the well-known damage of cell structure characteristics of heat-killed cells.


Assuntos
Eletroforese/métodos , Membrana Celular/metabolismo , Eletroquímica , Leveduras/metabolismo
14.
Mikrochim Acta ; 187(1): 1, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31797052

RESUMO

Aminopropyltrimethoxysilane (APTMS)-functionalized zinc oxide (ZnO) nanorods and carboxylated graphene nanoflakes (c-GNF) were used in a composite that was electrophoretically deposited on an indium tin oxide (ITO) coated glass substrate. The modified ITO electrodes were characterized using various microscopic and spectroscopic techniques which confirm the deposition of the APTMS-ZnO/c-GNF composite. The electrodes have been used for the covalent immobilization of an Escherichia coli O157:H7 (E. coli)-specific DNA prob. Impedimetric studies revealed that the gene sensor displays linear response in a wide range of target DNA concentration (10-16 M to 10-6 M) with a detection limit of 0.1 fM. The studies on the cross-reactivity to other water-borne pathogens show that the bioelectrode is highly specific. Graphical abstractSchematic illustration for fabrication of nucleic acid biosensor for E. coli DNA detection using an ITO electrode modified with siloxane-functionalized zinc oxide (ZnO) nanorods and carboxylated graphene nanoflakes (c-GNFs).


Assuntos
Técnicas Biossensoriais/métodos , DNA Bacteriano/análise , Escherichia coli O157/genética , Grafite/química , Nanotubos/química , Compostos de Estanho/química , Óxido de Zinco/química , Técnicas Biossensoriais/instrumentação , Ácidos Carboxílicos/química , Impedância Elétrica , Eletrodos , Eletroforese , Limite de Detecção
15.
J Med Case Rep ; 13(1): 384, 2019 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-31878962

RESUMO

INTRODUCTION: Polyneuropathy is a key feature of polyneuropathy, organomegaly, endocrinopathy, monoclonal band, and skin changes syndrome, which is a paraneoplastic manifestation of an underlying lymphoproliferative neoplasm. We report the first case of polyneuropathy, organomegaly, endocrinopathy, monoclonal band, and skin changes syndrome presenting with a pseudosensory level. CASE PRESENTATION: A 59-year-old Tamil woman with long-standing diabetes mellitus and hypertension developed painless, progressive inguinal lymphadenopathy. A contrast-enhanced computed tomography scan showed mild hepatomegaly and intra-abdominal lymphadenopathy. A histological examination of an enlarged inguinal lymph node showed features of a plasma cell-type Castleman disease. She was treated with rituximab. Six months later, she developed gradually ascending numbness and weakness of both lower limbs. On examination, she had flaccid paraparesis (power 3/5) with a sensory level to pinprick at thoracic level 9. Joint position sense was preserved. Her cranial nerves and upper limbs were neurologically normal. Nerve conduction studies confirmed peripheral neuropathy with conduction slowing and a magnetic resonance imaging of her spine did not show cord or root compression. Serum protein electrophoresis showed a monoclonal band. A bone marrow biopsy showed a hypercellular marrow with 30% plasma cells. A repeat contrast-enhanced computed tomography scan showed sclerotic bony lesions involving multiple vertebrae in addition to mild hepatomegaly and intra-abdominal lymphadenopathy. Polyneuropathy, organomegaly, endocrinopathy, monoclonal band, and skin changes syndrome was diagnosed and she was treated with intravenously administered pulse therapy of dexamethasone and cyclophosphamide. After three cycles of treatment, she regained normal muscle power and sensation. CONCLUSIONS: Polyneuropathy in polyneuropathy, organomegaly, endocrinopathy, monoclonal band, and skin changes syndrome can present as a pseudosensory level.


Assuntos
Ciclofosfamida/uso terapêutico , Dexametasona/uso terapêutico , Imunossupressores/uso terapêutico , Síndrome POEMS/diagnóstico por imagem , Paraparesia/diagnóstico por imagem , Recuperação de Função Fisiológica/fisiologia , Rituximab/uso terapêutico , Eletroforese , Feminino , Humanos , Imagem por Ressonância Magnética , Pessoa de Meia-Idade , Síndrome POEMS/tratamento farmacológico , Síndrome POEMS/fisiopatologia , Paraparesia/etiologia , Paraparesia/fisiopatologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
16.
PLoS One ; 14(12): e0226571, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856234

RESUMO

We present a simple to operate microfluidic chip system that allows for the extraction of miRNAs from cells with minimal hands-on time. The chip integrates thermoelectric lysis (TEL) of cells with native gel-electrophoretic elution (GEE) of released nucleic acids and uses non-toxic reagents while requiring a sample volume of only 5 µl. These properties as well as the fast process duration of 180 seconds make the system an ideal candidate to be part of fully integrated point-of-care applications for e.g. the diagnosis of cancerous tissue. GEE was characterized in comparison to state-of-the-art silica column (SC) based RNA recovery using the mirVana kit (Ambion) as a reference. A synthetic miRNA (miR16) as well as a synthetic snoRNA (SNORD48) were subjected to both GEE and SC. Subsequent detection by stem-loop RT-qPCR demonstrated a higher yield for miRNA recovery by GEE. SnoRNA recovery performance was found to be equal for GEE and SC, indicating yield dependence on RNA length. Coupled operation of the chip (TEL + GEE) was characterized using serial dilutions of 5 to 500 MCF7 cancer cells in suspension. Samples were split and cells were subjected to either on-chip extraction or SC. Eluted miRNAs were then detected by stem-loop RT-qPCR without any further pre-processing. The extraction yield from cells was found to be up to ~200-fold higher for the chip system under non-denaturing conditions. The ratio of eluted miRNAs is shown to be dependent on the degree of complexation with miRNA associated proteins by comparing miRNAs purified by GEE from heat-shock and proteinase-K based lysis.


Assuntos
Eletroforese/instrumentação , Dispositivos Lab-On-A-Chip , MicroRNAs/isolamento & purificação , RNA Nucleolar Pequeno/isolamento & purificação , Fatores de Tempo
17.
Electrophoresis ; 40(23-24): 3035, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31841230
18.
Environ Sci Technol ; 53(24): 14507-14515, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31709790

RESUMO

Humic acids (HAs) play important roles for the fate of metal ions in the environment. Most chemical speciation models involving HAs assume heterogeneous metal ion binding. However, these models also assume that the binding affinities of metal ions with HAs are the same regardless of the molecular weight (MW) ranges of the HAs involved. Here, we develop new polyacrylamide gel electrophoresis (PAGE) techniques to investigate the MW distributions of HAs with strongly complexed Cu2+ ions. By combining contaminant metal-free and high-resolution PAGE for HAs, this work was able to provide accurate MW distributions for the complexed metal ions. The MW distribution of Cu2+ binding ability per quantity of HA indicates that strong metal-binding moieties in HAs are heterogeneous in terms of MW. Coupling of the PAGE techniques with UV-vis and excitation-emission matrix (EEM) spectrometry-parallel factor analysis (PARAFAC) methods revealed new insights into kinetically inert interactions between HAs and Cu2+ ions. By this method, we found that the protein-like fluorescence components in the high- and low-MW regions cooperatively responded through Cu2+ binding. Thus, the advanced gel electrophoresis techniques developed herein are able to shed new light on the heterogeneity of metal binding affinities of HAs in terms of MW.


Assuntos
Substâncias Húmicas , Metais , Eletroforese , Análise Fatorial , Peso Molecular , Espectrometria de Fluorescência
19.
Forensic Sci Int ; 305: 110027, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31704515

RESUMO

Due the proteins from bone remains are highly resistant to pass of time and environmental conditions, they could tell us about the events that probably happened in the past. In the forensic and physical anthropology context, burnt bone remains are one of the most common pieces of recovered evidence and, generally, they are associated with funerary practices, criminal scenes or massive catastrophic events. In the present study, bone pieces of pigs were calcined at different calcination temperatures, and proteins were searched using biochemical, immunochemical and ultrastructure visualization under these experimentally conditions. For this purpose, it was successfully developed a non-demineralizing protein extraction method from burnt bone remains and the use of specific antibodies permitted the identification of different extracellular matrix and intracellular proteins. While collagen proteins type I and IV were identified and detected under middle and high calcination temperatures (300°C and 600°C); cytoskeletal proteins as actin, tubulin and, the microtubule associated protein Tau, were found under calcination process, even up high calcination temperatures. Under ultrastructural analysis, fibrous materials with a classical disposition of collagens were observed even at high calcination temperatures of the burnt bone remains. The protein identification and characterization in burnt bones as performed in present studies, is clearly demonstrating that using specific strategies for protein characterizations it is possible to found protein biomarkers in burnt bone remains and this strategy could be useful for forensic and anthropological purposes.


Assuntos
Osso e Ossos/química , Proteínas do Citoesqueleto/isolamento & purificação , Proteínas da Matriz Extracelular/isolamento & purificação , Fogo , Animais , Anticorpos/análise , Biomarcadores/química , Western Blotting , Técnica de Desmineralização Óssea , Osso e Ossos/patologia , Colágeno/ultraestrutura , Proteínas do Citoesqueleto/imunologia , Eletroforese , Proteínas da Matriz Extracelular/imunologia , Patologia Legal/métodos , Humanos , Microscopia Eletrônica de Varredura , Suínos , Temperatura
20.
Int J Mol Sci ; 20(22)2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31717257

RESUMO

Bcl-xL is an oncogene of which the survival functions are finely tuned by post-translational modifications (PTM). Within the Bcl-2 family of proteins, Bcl-xL shows unique eligibility to deamidation, a time-related spontaneous reaction. Deamidation is still a largely overlooked PTM due to a lack of easy techniques to monitor Asn→Asp/IsoAsp conversions or Glu→Gln conversions. Being able to detect PTMs is essential to achieve a comprehensive description of all the regulatory mechanisms and functions a protein can carry out. Here, we report a gel composition improving the electrophoretic separation of deamidated forms of Bcl-xL generated either by mutagenesis or by alkaline treatment. Importantly, this new gel formulation proved efficient to provide the long-sought evidence that even doubly-deamidated Bcl-xL remains eligible for regulation by phosphorylation.


Assuntos
Eletroforese/métodos , Processamento de Proteína Pós-Traducional , Proteína bcl-X/metabolismo , Células HCT116 , Humanos , Proteínas Mutantes/isolamento & purificação , Mutação/genética , Fosforilação
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