Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 852
Filtrar
1.
Carbohydr Polym ; 260: 117836, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712173

RESUMO

pH-sensitive polymeric dyes were fabricated by grafting phenol red (PR) and rosolic acid (RA) onto chitosan (CS) by a facile method. Successful grafting was confirmed by 1H NMR, FT-IR, UV-vis, XRD, and elemental analysis. The polymeric dyes exhibited no cell toxicity. The colorimetric pH-sensing films were fabricated by blending the polymeric dyes with CS to establish their pH-dependent color properties. The film color changed in the pH range 4-10, which may indicate food spoilage or wound status. Covalently grafting of polymeric dyes in the films led to excellent color stability, leaching resistance, and reversibility. Hence, the synthesized polymeric dyes had potential as pH-indicative colorants for food and biomedical fields.


Assuntos
Quitosana/química , Corantes/síntese química , Polímeros/química , Infecções Bacterianas/diagnóstico , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Corantes/química , Corantes/farmacologia , Armazenamento de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Fenolsulfonaftaleína/química
2.
Anal Methods ; 13(2): 169-178, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33399137

RESUMO

We demonstrate a loop-mediated isothermal amplification (LAMP) method to detect and amplify SARS-CoV-2 genetic sequences using a set of in-house designed initiators that target regions encoding the N protein. We were able to detect and amplify SARS-CoV-2 nucleic acids in the range of 62 to 2 × 105 DNA copies by this straightforward method. Using synthetic SARS-CoV-2 samples and RNA extracts from patients, we demonstrate that colorimetric LAMP is a quantitative method comparable in diagnostic performance to RT-qPCR (i.e., sensitivity of 92.85% and specificity of 81.25% in a set of 44 RNA extracts from patients analyzed in a hospital setting).


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , RNA/análise , SARS-CoV-2/química , Carga Viral/métodos , COVID-19/diagnóstico , Colorimetria/métodos , Proteínas do Nucleocapsídeo de Coronavírus , DNA/análise , DNA/química , Corantes Fluorescentes/química , Humanos , Substâncias Intercalantes/química , Fenolsulfonaftaleína/química , Fosfoproteínas , RNA/química
3.
Talanta ; 224: 121816, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33379041

RESUMO

The single tumor antigen does not have enough specificity and sensitivity to meet the accurate diagnostic criteria, and single antigen measurement is often prone to false negative and false positive perceptions. Therefore, simultaneous monitoring of multiple tumor antigens related to precise tumors in serum samples has become an interesting and encouraging analytical method. In this work, we demonstrated an electrochemical biosensor based on multiple signal amplification methods, and simultaneously detect two lung cancer markers, cytokeratin 19 fragment 21-1 (CYFRA21-1) and carcinoembryonic antigen (CEA). Large number of gold nanoparticles distributed on the surface of three-dimensional graphene (3D-G), poly-thionine (pThi) and poly-m-Cresol purple (pMCP) not only provide large number of binding sites for antigen and antibody, but also enhance the electrochemical signal of biosensor and greatly improves the sensitivity of the biosensor. The detection linear range extends from 0.5 to 200 ng/mL, with low detection limits (LOD) of 0.18 ng/mL and 0.31 ng/mL for CYFRA21-1 and CEA, respectively. Overall, this kind of immune-biosensor provides great potential for the simultaneous detection of multiple targets in early clinical diagnosis.


Assuntos
Neoplasias Pulmonares , Nanopartículas Metálicas , Antígenos de Neoplasias , Biomarcadores Tumorais , Antígeno Carcinoembrionário , Ouro , Humanos , Queratina-19 , Neoplasias Pulmonares/diagnóstico , Fenolsulfonaftaleína/análogos & derivados , Fenotiazinas
4.
Molecules ; 25(21)2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33158074

RESUMO

Phenol red (PR) is a widely used marker for water flux correction in studies of in situ perfusion, in which intestinal absorption usually leads to the underestimation of results. In this paper, we propose a novel marker polyethylene glycol (PEG)-PR (i.e., PR modified by PEGylation) with less permeability and evaluate its application in an in situ perfusion model in rats. PEG-PR was synthesized by the chemical conjunction of polyethylene glycol-4k/5k (PEG-4k/5k) and PR. The synthesized PEG-PR was then characterized using 1H-NMR, 13C-NMR, ultraviolet (UV), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) analyses. The low permeability of PEG-PR was assessed using everted gut sac (EGS) methods. The apparent permeability coefficients (Papp, 3-8 × 10-7 cm/s) of PEG4k/5k-PR exhibited a nearly 15-fold reduction compared to that of PR. The different concentrations of PEG4k/5k-PR did not contribute to the Papp value or cumulative permeable percentage (about 0.02-0.06%). Furthermore, the larger molecular weight due to PEGylation (PEG5k-PR) enhanced the nonabsorbable effect. To evaluate the potential application of the novel marker, atenolol, ketoprofen, and metoprolol, which represent various biopharmaceutics classification system (BCS) classes, were selected as model drugs for the recirculation perfusion method. The water flux corrected by PEG4k/5k-PR reflected the accuracy due to the nonabsorbable effect, while the effective intestinal membrane permeability (Peff) of atenolol corrected by PEG4k/5k-PR showed a statistically significant increase (p < 0.05) in different intestinal segments. In conclusion, PEG-PR is a promising marker for the permeability estimation when using the in situ perfusion model in rats.


Assuntos
Absorção Intestinal , Modelos Biológicos , Fenolsulfonaftaleína , Polietilenoglicóis , Água/metabolismo , Animais , Avaliação de Medicamentos , Masculino , Perfusão , Permeabilidade , Fenolsulfonaftaleína/química , Fenolsulfonaftaleína/farmacocinética , Fenolsulfonaftaleína/farmacologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Ratos , Ratos Wistar
5.
Transl Vis Sci Technol ; 9(10): 23, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33024616

RESUMO

Purpose: Noninvasive analyses of tear fluid from humans and animal models in clinical and research settings most commonly use absorbent material for collection and processing. Still, the impact of these analytical techniques on tear chemical analyses remains largely unknown. The purpose of this study was to quantify the impacts of phenol red thread fiber-based tear sample collection and processing on the primary amine content. Methods: Human tears were collected by placing the folded end of phenol red thread on the palpebral conjunctiva of the right eye for 20 seconds. The wetted thread was then processed using elution or extraction, and capillary electrophoresis with light-emitting diode-induced fluorescence detection was used for analysis and quantitation. Results: Distinct processing methods impacted tear analysis differently. Primary amines adsorbed onto the thread partitioned in a chromatographic manner and thus any single portion of the wetted thread might not be representative of the whole sample. Quantitative assessment of five small molecule standards after on-thread processing showed significant overestimation of the actual concentration, with increased accuracy for larger volume samples. Yet collection of larger tear volumes introduced error in volume determination owing to evaporation and reduced small molecule separation resolution. Conclusions: These results indicated that absorption-based tear fluid collection and processing significantly alter chemical content analysis, suggesting that the impacts of methods used should be regularly evaluated to standardize results drawn from different studies. Translational Relevance: This study identifies potential inconsistencies and inaccuracies in tear analyses that are widespread across the published literature and clinical care.


Assuntos
Fenolsulfonaftaleína , Lágrimas , Animais , Eletroforese Capilar , Olho , Humanos , Manejo de Espécimes
6.
J Agric Food Chem ; 68(45): 12710-12718, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33118801

RESUMO

This work presents a colorimetric dye-based array for naked-eye detection of chicken meat spoilage. The array is obtained by fixing five acid-base indicators, m-cresol purple (1), o-cresol red (2), bromothymol blue (3), thymol blue (4), and chlorophenol red (5), and a sensing molecule specific for thiols, 5,5'-dithiobis(2-nitrodibenzoic acid), called Ellman's reagent (6), on a cellulose-based support. The dyes, being permanently charged, are fixed on the support via ion-exchange. The entire degradation process of beast poultry meat, at ambient temperature and in a domestic fridge, is followed by the change of the color of the array, placed in the headspace over the meat samples. The device is set after selection of the most suitable starting form, which could be the acidic or the basic color of indicators, being the proper dye concentration and the dimension of the spots already established. Basing on sensors colors, we identified three levels of the degradation process of chicken meat, named SAFE, WARNING, and HAZARD. By instrumental analysis, we demonstrated that sensors response was correlated to volatile organic compounds (VOCs) composition in the headspace and, thus, to meat spoilage progress. We demonstrated that biogenic amines (BAs), commonly considered a critical spoilage marker, are indeed produced into the samples but never present in the headspace, even in traces, during the investigated time-lapse. The VOC evolution nevertheless allows one to assign the sample as WARNING and further HAZARD. Some indicators turned out to be more informative than others, and the best candidates for a future industrial application resulted in a bromothymol blue (3)-, chlorophenol red (5)-, and Ellman's reagent (6)-based array.


Assuntos
Corantes/análise , Carne/análise , Animais , Azul de Bromotimol/análise , Galinhas , Cor , Colorimetria , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Inocuidade dos Alimentos , Fenolsulfonaftaleína/análogos & derivados , Fenolsulfonaftaleína/análise , Timolftaleína/análogos & derivados , Timolftaleína/análise , Compostos Orgânicos Voláteis/análise
7.
J Agric Food Chem ; 68(45): 12702-12709, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33125233

RESUMO

The rationale behind the material and dye selection and the investigation of the properties of a solid-phase sensor array designed for following chicken meat spoilage is presented, having in mind that the final target must be the naked eye identification of the degradation steps. The device is obtained by fixing five acid-base indicators, m-cresol purple (1), o-cresol red (2), bromothymol blue (3), thymol blue (4), and chlorophenol red (5), and a sensing molecule specific for thiols, 5,5'-dithiobis(2-nitrodibenzoic acid), called Ellman's reagent, (6) on a commercial cellulose-based support. The dimensions of the sensor and the amount of dye sorbed on the solid are carefully studied. The preparation protocol to get reproducible sensing materials is established, based on the kinetic study and the color change investigation. The material stability and the capacity of changing color, according to the acid-base properties of the dyes, are tested. The sources of uncertainty, coming from the technique employed for signal data acquisition and treatment and from the intrinsic variability of the spots based on the commercial support, are established. The highest variability does not come from photo acquisition by a mobile phone, the effect of the illumination equipment, the partial least-squares (PLS) model employed to assess the amount of dye sorbed into the solid but from the variability of different spots and was found equal to 10%. The uncertainty is adequate for final employment since it is referred to as replicates under different conditions that are definitively judged almost always identical by naked eye evaluation, which is our last target for assessing a change of the colors associated with spoilage.


Assuntos
Corantes/análise , Análise de Alimentos/métodos , Carne/análise , Animais , Azul de Bromotimol/análise , Galinhas , Cor , Análise de Alimentos/instrumentação , Fenolsulfonaftaleína/análogos & derivados , Fenolsulfonaftaleína/análise , Timolftaleína/análogos & derivados , Timolftaleína/análise
8.
Talanta ; 219: 121202, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887109

RESUMO

Relying on the specific coordination of Ag+ and mismatched cytosine-cytosine (C-C), the high-efficiency inhibition of urease by Ag+ ion, and the rapid and sensitive response of phenol red to pH, a sensitive ratiometric sensor has been designed for visual detection of human immunodeficiency virus gene (HIV DNA). This sensor utilizes the HIV DNA to initiate catalytic hairpin assembly (CHA) process, releasing Ag+ to inhibit subsequent urease-catalyzed urea hydrolysis and prevent the pH of the solution from rising. The CHA process and the absorbance ratio of phenol red at different wavelengths (A559/A432) amplify the signal, allowing the sensor to detect HIV DNA from 10 to 130 nM in a sensitive and highly selective manner with a low detection limit of 7.8 nM. In addition, this sensor can visually distinguish different concentrations of HIV DNA within a certain range and possesses a good recovery in 1% of serum samples, which will provide new ideas for biosensor design, dipstick test, blood test, and other clinical disease prevention.


Assuntos
Técnicas Biossensoriais , Infecções por HIV , Catálise , HIV/genética , Infecções por HIV/diagnóstico , Humanos , Limite de Detecção , Fenolsulfonaftaleína
9.
Vet Parasitol ; 285: 109224, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32947234

RESUMO

Theileria annulata the causative agent of bovine tropical theileriosis (BTT) is globally distributed. Rapid and accurate detection of the parasite is essential for the implementation and evaluation of mass drug administration and planned vaccination programs for controlling BTT. Loop mediated isothermal amplification (LAMP) amplifies targeted nucleic acid with a high efficacy, sensitivity and rapidity under isothermal conditions. In the present study, the internal transcriber space (ITS) gene of T. annulata was targeted for the development of a LAMP assay using pH-sensitive dye (phenol red) for enhanced visual detection of amplification. This method employed a set of specially designed four primers that recognized six distinct regions on the targeted gene. No amplification was detected with the DNA of other tested haemoprotozoans. Positive LAMP products were identified by a colour change from pink to yellow, and then rechecked by specific ladder pattern upon agarose gel electrophoresis. LAMP was able to detect infection in 63 out of 85 animals compared with blood microscopy, simple PCR and nested PCR which detected infection in 40, 49 and 64 animals, respectively. No difference in detection was seen in the colorimetric assay and the classical UV based LAMP assay.


Assuntos
Técnicas de Diagnóstico Molecular/veterinária , Técnicas de Amplificação de Ácido Nucleico/veterinária , Theileriose/diagnóstico , Animais , Bovinos , Colorimetria/veterinária , Primers do DNA/genética , DNA Intergênico/genética , Fenolsulfonaftaleína/química , Sensibilidade e Especificidade , Theileria annulata/genética
10.
Anal Chem ; 92(19): 13343-13353, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32838514

RESUMO

Loop-mediated isothermal amplification (LAMP) as a diagnostic tool is rapidly gaining recognition and maturity. Among various advantages over traditional polymerase chain reaction, the ability to visually detect amplification by the incorporation of colorimetric indicators is one of its most unique features. There is an overwhelming variety of LAMP indicators in the literature, yet a comprehensive comparative study is lacking. This study evaluates the use of hydroxynaphthol blue, phenol red, calcein, leuco crystal violet, malachite green, and a fluorescent dye for visual detection. A method for objective quantitative analysis using ImageJ is described that is readily implemented in standard and microfluidic workflows. The work here also includes the largest inter-reader variability study involving 24 participants to evaluate these indicators. We found inaccuracies in visual assessment as bias and/or individual-based perception can exist, solidifying the need for objective analysis. There was not a "universal" indicator, although considerations in sample preparation, storage, and applicability are discussed in length.


Assuntos
Fluoresceínas/análise , Indicadores e Reagentes/química , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Colorimetria , Fluoresceínas/química , Corantes Fluorescentes/química , Violeta Genciana/química , Humanos , Dispositivos Lab-On-A-Chip , Naftalenossulfonatos/química , Fenolsulfonaftaleína/química , Corantes de Rosanilina/química
11.
Biotechniques ; 69(3): 178-185, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32635743

RESUMO

Loop-mediated isothermal amplification (LAMP) is a versatile technique for detection of target DNA and RNA, enabling rapid molecular diagnostic assays with minimal equipment. The global SARS-CoV-2 pandemic has presented an urgent need for new and better diagnostic methods, with colorimetric LAMP utilized in numerous studies for SARS-CoV-2 detection. However, the sensitivity of colorimetric LAMP in early reports has been below that of the standard RT-qPCR tests, and we sought to improve performance. Here we report the use of guanidine hydrochloride and combined primer sets to increase speed and sensitivity in colorimetric LAMP, bringing this simple method up to the standards of sophisticated techniques and enabling accurate, high-throughput diagnostics.


Assuntos
Betacoronavirus/isolamento & purificação , Técnicas de Laboratório Clínico/métodos , Guanidina , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Teste para COVID-19 , Técnicas de Laboratório Clínico/normas , Colorimetria , Infecções por Coronavirus/diagnóstico , Humanos , Técnicas de Diagnóstico Molecular/normas , Técnicas de Amplificação de Ácido Nucleico/normas , Fenolsulfonaftaleína , SARS-CoV-2
12.
Mediators Inflamm ; 2020: 2929163, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508523

RESUMO

Relieving Sore Throat Formula (RSTF) is a formula approved by the China Food and Drug Administration and has been used for the treatment of pharyngitis in clinic for many years. However, the potential pharmacological mechanism still remains unknown. We combined multiple methods including bioinformatics data digging, network pharmacology analysis, and pathway analysis to predict the potential target of RSTF. We verified our in silico prediction results with an in vivo/vitro antibacterial effect test, mouse phagocytic index test, proliferation, transformation, and migration of mouse spleen lymphocytes. Alteration of NF-κB pathway was determined by Western blotting, immunofluorescence, and PCR. The in vivo experiments demonstrated that the RSTF could significantly relieve the symptoms of pharyngitis. A rat saliva secretion test showed that RSTF can effectively relieve the xerostomia symptom. A phenol red excretion test showed that RSTF has an eliminating phlegm effect. A hot plate method and granuloma experiment proved that RSTF also have analgesic and anti-inflammatory effects. In silico prediction demonstrates that 70 active compounds of RSTF were filtered out through ADME screening and 84 putative targets correlated with different diseases. Pathway enrichment analysis showed that the candidate targets were mostly related to the response to bacteria and immunity signalling pathways, which are known contributors to pharyngitis. Experimental results confirmed that RSTF exerted therapeutic effects on pharyngitis mainly by antibacterial effect and downregulation of NF-κB activities. It is demonstrated both in silico and in vivo/vitro that RSTF exerted therapeutic effects on pharyngitis mainly through an antibiotic effect and downregulation of NF-κB signalling pathway.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , NF-kappa B/metabolismo , Faringite/tratamento farmacológico , Animais , Antibacterianos/uso terapêutico , Movimento Celular , Proliferação de Células , Celulose/química , Biologia Computacional , Simulação por Computador , Regulação para Baixo , Granuloma/metabolismo , Proteínas Hemolisinas/sangue , Sistema Imunitário , Imunidade Inata , Masculino , Camundongos , Camundongos Endogâmicos ICR , Ácido N-Acetilneuramínico/metabolismo , Fagocitose , Fenolsulfonaftaleína/química , Extratos Vegetais/uso terapêutico , Ratos , Saliva/metabolismo , Transdução de Sinais , Baço/metabolismo , Temperatura , Xerostomia/terapia
13.
Artigo em Inglês | MEDLINE | ID: mdl-32416593

RESUMO

One of the most common techniques for assessing the intestinal absorption characteristics of drugs is single-pass intestinal perfusion (SPIP) method. Metoprolol tartrate (MT, reference standard) and phenol red (PR, zero permeability marker) are the compounds that are normally used in SPIP studies. The aim of this study was to develop a reverse phase high-performance liquid chromatography (RP-HPLC) method combined with UV-detection for the simultaneous determination of MT and PR in the perfusion medium used in SPIP experiments. Elution was performed using a Restek Raptor C18 column (5 µm, 4.6 mm × 250) at a temperature of 25 °C. The mixture of the mobile phase consisted of (MeOH):(Phosphate buffer solution, PBS), (20 mM, pH 3.0 adjusted with ortho-phosphoric acid),(55:45, v/v). Flow rate and column temperature were set at 1.2 mL min-1 and 25 °C, respectively. MT and PR were injected as 20 µL into the HPLC system. UV detection was performed at 227 nm. The obtained retention times were reported as 2.89 and 3.80 min for MT and PR, respectively. The developed RP-HPLC method was validated according to Q2(R1) guideline of The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). The method was linear within the range of 2-50 µg mL-1 for PR and 10-75 µg mL-1 for MT. The developed RP-HPLC method was successfully applied on determination of MT and PR in perfusion medium. The developed method could be helpful for researchers working on in-situ rat intestinal permeability studies and it could be easily modified on further studies.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Metoprolol/análise , Fenolsulfonaftaleína/análise , Cromatografia Líquida de Alta Pressão/normas , Cromatografia de Fase Reversa/normas , Limite de Detecção , Modelos Lineares , Padrões de Referência , Reprodutibilidade dos Testes , Projetos de Pesquisa
14.
Sci Rep ; 10(1): 4829, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-32179842

RESUMO

Abnormal keratinocyte differentiation is fundamental to pathologies such as skin cancer and mucosal inflammatory diseases. The ability to grow keratinocytes in vitro allows the study of differentiation however any translational value is limited if keratinocytes get altered by the culture method. Although serum lipids (SLPs) and phenol red (PR) are ubiquitous components of culture media their effect on differentiation is largely unknown. We show for the first time that PR and SLP themselves suppress expression of differentiation-specific keratins K1, K10 and K2 in normal human epidermal keratinocytes (NHEK) and two important cell lines, HaCaT and N/TERT-1. Removal of SLP increased expression of K1, K10 and K2 in 2D and 3D cultures, which was further enhanced in the absence of PR. The effect was reversed for K1 and K10 by adding all-trans retinoic acid (ATRA) but increased for K2 in the absence of PR. Furthermore, retinoid regulation of differentiation-specific keratins involves post-transcriptional mechanisms as we show KRT2 mRNA is stabilised whilst KRT1 and KRT10 mRNAs are destabilised in the presence of ATRA. Taken together, our results indicate that the presence of PR and SLP in cell culture media may significantly impact in vitro studies of keratinocyte differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Queratina-10/genética , Queratina-10/metabolismo , Queratina-1/genética , Queratina-1/metabolismo , Queratina-2/genética , Queratina-2/metabolismo , Queratinócitos/metabolismo , Queratinócitos/fisiologia , Lipídeos/fisiologia , Fenolsulfonaftaleína/farmacologia , Tretinoína/farmacologia , Células Cultivadas , Células HaCaT , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
15.
Prep Biochem Biotechnol ; 50(8): 803-813, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32163010

RESUMO

Several soil isolates from 1 g of soil sample were isolated and screened for the production of L-asparaginase. Primary screening was performed using rapid plate assay; dye indicator studies were conducted, and phenol red with 0.005% concentration was found to be optimum. The secondary screening was carried out using the Nesslerization method. The bacteria screened for L-asparaginase production with no glutaminase activity was identified as Bacillus subtilis. Crude L-asparaginase enzyme was partially purified 1.57 folds of purity and 110 U/mg of specific activity. The glutaminase-free L-asparaginase activity was also confirmed using LC-MS analysis. The presence of mass peaks at 147.0 in the reaction mixture suggested an absence of glutaminase activity. An optimized medium obtained comprised of Dextrose 1.5 g/L, K2HPO4 1.2 g/L, L-asparagine 15 g/L, and Tryptone 5 g/L. The highest L-asparaginase activity was observed at 6.0 pH and 30 °C. Kinetic parameters associated with biomass and L-asparaginase production were also studied. The computed values were µm 0.104 h-1, Xm 6g/L P0 1.7U/mL Pm 8.2 U/mL YX/S 4 g-cell/g-glucose µPm 0.35 h-1 qp 5.46 U/g/h YP/x 13.6667 U/g-cell. The novel bacterial isolates showed promise as a potential glutaminase-free L-asparaginase producer, which can prove to be of industrial applications.


Assuntos
Asparaginase/metabolismo , Bacillus subtilis/enzimologia , Bacillus subtilis/isolamento & purificação , Microbiologia do Solo , Bacillus subtilis/metabolismo , Corantes , Glutaminase/metabolismo , Indicadores e Reagentes , Cinética , Fenolsulfonaftaleína
16.
ACS Appl Mater Interfaces ; 12(8): 9782-9789, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32011116

RESUMO

Thermochromic materials exhibit a color change in response to a change in temperature. Creating nontoxic microcapsules containing thermochromic materials for applications in ink and film materials is historically challenging. In this study, we develop a nontoxic chlorophenol red (CPR)-water thermochromic system and its microcapsules with silicone shells via a reaction between water and octadecyltrichlorosilane (OTS) at the interface of a w/o emulsion. The obtained microcapsules exhibit a clear color change with full reversibility and are successfully used as inks by screen printing and as additives in films. Nontoxicity of both microcapsules and films is demonstrated through cell cytotoxicity assays. These features make these novel materials applicable to the next generation of intelligent sensors, coating, and food packaging materials.


Assuntos
Teste de Materiais , Membranas Artificiais , Fenolsulfonaftaleína/análogos & derivados , Silanos , Silicones , Animais , Cápsulas , Camundongos , Células NIH 3T3 , Fenolsulfonaftaleína/química , Fenolsulfonaftaleína/farmacologia , Silanos/química , Silanos/farmacologia , Silicones/química , Silicones/farmacologia , Temperatura
17.
Vet Ophthalmol ; 23(2): 234-244, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31562703

RESUMO

OBJECTIVE: The purpose of this study is to evaluate a group of young commercially available Skinny pigs, to gain information regarding ocular findings in this breed of guinea pig. Comparisons of ocular findings are to be made between Skinny pigs and haired guinea pigs. ANIMAL STUDIED: Ten haired guinea pigs and ten Skinny pigs were examined. PROCEDURE: A complete ophthalmic examination including Schirmer tear test-II (STT-II), phenol red thread test (PRTT), rebound tonometry with TonoVet PLUS, Fluorescein and Rose Bengal stain was performed. Microbiology swabs for aerobic bacterial growth were collected from conjunctiva of both eyes prior to the ophthalmic examination. RESULTS: The ophthalmic examination revealed seven abnormal ocular findings: trichiasis, mucopurulent discharge, hyperemia/chemosis of the conjunctiva, corneal fibrosis, corneal vascularization, and foreign body on the cornea or conjunctiva. Skinny pigs had a significantly higher amount of mucopurulent discharge (P = .0133) and a significantly higher STT-II (P < .001) than haired guinea pigs. Although not significant, trichiasis, keratitis with corneal vascularization, and foreign body presence were more common in Skinny pigs. Significantly more Skinny pigs had Pasteurellaceae isolated from their conjunctiva than haired guinea pigs (P = .0112). Antimicrobial susceptibility for the five Pasteurellaceae organisms isolated revealed susceptibility toward oxytetracycline, tobramycin, ciprofloxacin, and ofloxacin, whereas resistance was found toward erythromycin, trimethoprim-sulfamethoxazole, and moxifloxacin. CONCLUSION: Young Skinny pigs have a higher risk of Pasteurellaceae-associated conjunctivitis. Oxytetracycline, tobramycin, ciprofloxacin, and ofloxacin were identified as topical antibiotics that may be useful for Pasteurellaceae-associated conjunctivitis in Skinny pigs.


Assuntos
Testes Diagnósticos de Rotina/veterinária , Cobaias , Tonometria Ocular/veterinária , Animais , Infecções Bacterianas/microbiologia , Infecções Bacterianas/veterinária , Conjuntivite/microbiologia , Conjuntivite/veterinária , Técnicas de Diagnóstico Oftalmológico/veterinária , Displasia Ectodérmica/diagnóstico , Displasia Ectodérmica/veterinária , Oftalmopatias/diagnóstico , Oftalmopatias/veterinária , Feminino , Cabelo , Pressão Intraocular , Masculino , Fenolsulfonaftaleína , Lágrimas
18.
Toxicol In Vitro ; 62: 104676, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31629898

RESUMO

Bisphenol A (BPA) is commonly present in plastics used for food storage and preservation. The release of BPA from these products results in a permanent human exposition to BPA; however, the quality and quantity of BPA adverse effects remain a matter of controversy. The common presence of BPA in the human environment and the controversies concerning the relations of human exposition to BPA and cancer incidence justify the research on the interactions between BPA and pro-metastatic signaling in cancer cells. Here, we describe a novel BPA-reactive signaling axis that induces the epithelial-mesenchymal transition (EMT) in lung adenocarcinoma A549 cells. BPA exerted negligible effects on their properties in a wide range of concentrations (10 nM - 100 nM), whereas it considerably induced A549 invasiveness at high concentrations (10 µM). The BPA-induced EMT was illustrated by morphologic changes, E/N-cadherin switch and vimentin/Snail-1/connexin(Cx)43 up-regulation in A549 populations. It was followed by enhancement of A549 drug-resistance. Corresponding effects of BPA were observed in prostate cancer cell populations. Concomitantly, we observed increased levels and perinuclear accumulation of estrogen-related receptor gamma (ERRγ) in BPA-treated cells, its interactions with Cx43/Snail-1, and the corresponding effects of phenol red on A549 cells. Collectively, these data identify a novel, pro-metastatic Snail-1/Cx43/ERRγ signaling pathway. Its reactivity to BPA underlies the induction of cancer cells' invasiveness in the presence of high BPA concentrations in vitro. Thus, the chronic exposition of cancer cells to extrinsic and intrinsic BPA should be considered as a potential obstacle in a cancer therapy.


Assuntos
Compostos Benzidrílicos/toxicidade , Movimento Celular/efeitos dos fármacos , Conexina 43/metabolismo , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Estrogênios/toxicidade , Fenóis/toxicidade , Receptores de Estrogênio/metabolismo , Fatores de Transcrição da Família Snail/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Fenolsulfonaftaleína
19.
J Microbiol Methods ; 165: 105722, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31520656

RESUMO

Dermatophytosis is one of the most common superficial fungal infections, which is mainly caused by filamentous fungi such as Trichophyton species. A challenging aspect in dermatophyte research is the lack of a straightforward method to measure the rate of growth, in particular when growing dermatophytes in small volumes such as in microtitre plates. However, one characteristic of dermatophytes is their ability to produce compounds such as ammonia that make the growth medium more alkaline. The objective of this study was to test whether the change in pH in a liquid medium, colourimetrically established using the indicator phenol red, was linearly and directly proportional to the growth rate for Trichophyton rubrum and Trichophyton interdigitale. The changes in the colour determined by the phenol-red based assay showed a good correlation with the amount of fungal biomass over an incubation period of 24-120 h. The functionality of the phenol red assay was also validated in experiments on the growth of T. rubrum in the presence of antifungals. The changes in colour showed a clear dose-response relationship compounds and enabled determination of the minimum inhibitory concentration. The phenol red assay is thus a simple and straightforward assay to monitor the rate of growth of Trichophyton spp. and test antifungal activity.


Assuntos
Antifúngicos/farmacologia , Testes de Sensibilidade Microbiana , Tinha/microbiologia , Trichophyton/efeitos dos fármacos , Trichophyton/crescimento & desenvolvimento , Meios de Cultura/química , Humanos , Fenolsulfonaftaleína
20.
J Colloid Interface Sci ; 555: 145-156, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31377640

RESUMO

Resin hemoperfusion is a life-saving treatment for drug intoxication or hepatic failure of patients. However, current resin adsorbents exhibit a limited hemocompatibility or low adsorption efficiency, representing a major roadblock to successful clinical applications. In this work, we developed a hemocompatible and effective hemoadsorbent based on polystyrene resin (H103) microparticles encapsulated in anti-biofouling zwitterionic poly(carboxybetaine) (PCB) hydrogels. Apart from a strong mechanical stability, this PCB-based adsorbent (PCB-H103) exhibited excellent hemocompatibility (hemolysis ratio was ∼0.64%), which was attributed to the anti-biofouling property of PCB hydrogel. In addition, it can efficiently adsorb both small and middle molecular weight molecules in phosphate-buffered saline, and the efficiencies were significantly higher than poly(ethylene glycol) methacrylate-based and poly(2-hydroxyethyl methacrylate)-based adsorbent counterparts, indicating the favorable permeability of PCB hydrogel coating. More importantly, PCB-H103 could effectively remove protein-bound toxins including phenol red and bilirubin in bovine serum albumin solution or even in 100% fetal bovine serum (FBS). In 100% FBS, the adsorption capacity of PCB-H103 towards bilirubin was 8.3 times higher than that of pristine clinical-scale resin beads. Findings in this work may provide a new strategy for the development of modern resin hemoperfusion technology.


Assuntos
Bilirrubina/isolamento & purificação , Materiais Biocompatíveis/química , Fenolsulfonaftaleína/isolamento & purificação , Soroalbumina Bovina/isolamento & purificação , Adsorção , Animais , Bilirrubina/química , Humanos , Hidrogéis/química , Tamanho da Partícula , Fenolsulfonaftaleína/química , Soroalbumina Bovina/química , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...