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1.
Molecules ; 28(18)2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37764368

RESUMO

Mechanically separated meat (MSM) is a by-product of the poultry industry that requires routine quality assessment. Calcium content is an indirect indicator of bone debris in MSM but is difficult to determine by EDTA titration due to the poor solubility of calcium phosphate. Therefore, 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid was used instead, which has two orders of magnitude higher affinity for calcium ions. In addition, the auxiliary complexing agents triethanolamine and Arsenazo III, an indicator that is sensitive to low calcium concentrations, were used. Automatic titration endpoint detection was performed using an immersion probe at 660 nm. It has been shown that the color change in Arsenazo III can also be read with an RGB camera. The CDTA titration procedure has been tested on commercial Bologna-type sausages and the results were in line with AAS and ICP reference data. The content of calcium in sausages turned out to be very diverse and weakly correlated with the content of MSM. The tested MSM samples had a wide range of calcium content: from 62 to 2833 ppm. Calcium-rich poultry by-products include fat and skin (115 to 412 ppm), articular cartilage (1069 to 1704 ppm), and tendons (532 to 34,539 ppm). The CDTA titration procedure is fully suitable for small meat processing plants due to its simplicity of use and low cost.


Assuntos
Produtos da Carne , Produtos da Carne/análise , Cálcio , Arsenazo III , Carne/análise , Ácidos
2.
Anal Chem ; 94(44): 15176-15182, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36301518

RESUMO

This technical note reports for the first time the simultaneous vapor generation of 16 rare-earth elements (REEs) via reaction with sodium tetrahydroborate (THB). Significant improvement in REE vapor generation efficiency was discovered in the presence of arsenazo III (ARS). Subsequent to a critical evaluation on the impacts of various experimental variables, including the concentrations of acids, THB, and ARS, blank-limited (reagent contamination and impurity from ARS) detection limits (LODs) in the range of 0.004-0.15 µg L-1 were achieved based on three times the standard deviation of the method blank by the proposed vapor generation inductively coupled plasma mass spectrometry (ICP-MS). The nature of released REE species was studied by various approaches and identified to be REE nanoparticles and REE-ARS chelates; a dual-route mechanism for the vapor generation of REEs was thereby proposed.


Assuntos
Metais Terras Raras , Nanopartículas , Arsenazo III , Gases
3.
Urolithiasis ; 50(6): 737-742, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36064981

RESUMO

The use of double J ureteral stents can lead to several adverse effects, as urinary infection. Bacteria tend to colonize the stent surface, leading to the formation of bacterial biofilms. The presence of urease-producing bacteria increase the urine pH leading to the incrustation and blockage of the stent. On the other hand, these large crystalline masses function as niduses, allowing the attachment of even more bacteria and decreasing its exposure to antibiotics. The aim of this in vitro study was to assess the effect of phytate on the attachment of bacteria to the catheter surface under conditions that favor crystallization. Catheter sections were incubated in a synthetic urine medium (pH 6.5) in the presence or absence of Pseudomonas aeruginosa and phytate. Amount of calcium deposits was measured using an Arsenazo III colorimetric method and the number of attached bacteria to the stent was determined. Differences were assessed using an ANOVA with a Bonferroni post hoc test. The formation of calcium phosphate deposits (brushite and hydroxyapatite) and oxalate crystals (COM), as were as the amount of bacteria decreased when phytate was present. Thus, phytate successfully decreased bacterial adhesion by inhibiting the formation of crystalline deposits.


Assuntos
Cálcio , Ácido Fítico , Humanos , Cristalização , Urease , Arsenazo III , Fosfatos de Cálcio/química , Oxalato de Cálcio/química , Bactérias , Durapatita , Stents/efeitos adversos , Antibacterianos
4.
Biometals ; 33(1): 75-85, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31897857

RESUMO

To understand the biological effects of Thorium-232 (Th) in human cells and animal models as well as to assess mitigation strategies for its detoxification, there is a need to develop a sensitive, specific, high-throughput and easily-implementable assay for detection and estimation of Th in biological samples. Here, we have optimized arsenazo-III dye based colorimetric assay to detect Th in biological samples. The concentration of arsenazo-III (i.e. 50 µM) was optimized, which can reliably estimate Th in the concentration range of 2.5 to 40 µM. The optimized assay can specifically detect Th without interference from other metal ions (La, Ce, U, Fe, Ca, Cu, Zn and Mn). A significant correlation (R2 = 0.999) was found between arsenazo-III-based detection of Th and total reflection X-ray fluorescence. The conditions of present assay successfully estimated Th in cell culture medium, cell harvesting (trypsin-EDTA) solution and cell lysate obtained from human liver cell culture. Moreover, for the first time, we detected Th in-situ in adherent liver cells in culture after staining with arsenazo-III. This study confirms that Th can be specifically determined in biological samples using arsenazo-III with the sensitivity, which is relevant to thorium toxicity research.


Assuntos
Arsenazo III/química , Corantes/química , Tório/análise , Colorimetria , Células Hep G2 , Humanos , Estrutura Molecular , Células Tumorais Cultivadas
5.
Int J Biol Macromol ; 137: 107-118, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31254581

RESUMO

N-allylthiourea chitosan (ATUCS), a chelating material, was prepared, characterized, and studied for the removal of arsenazo III (As (III)) dye from aqueous solution. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and 1H- and 13C-nuclear magnetic resonance (NMR) were used to characterize the prepared adsorbent and to investigate the adsorption mechanism. Furthermore, the adsorption behavior of chitosan (CS) and ATUCS were studied under various conditions. The equilibrium adsorbed amount of As (III) onto ATUCS was found to be 116.3 mg/g, compared to 87.3 mg/g with respect to CS. The regeneration of the loaded CS and ATUCS were studied using 1:1 solution of H2O2-H2SO4 and reused with certain change in efficiency after the third cycle. The adsorption process was found to fit well with pseudo-second-order kinetic model. The equilibrium data were better described with the Freundlich isotherm. The monolayer adsorption capacity was found to be 204.08 and 90.90 mg/g for the As (III)/ATUCS and As (III)/CS systems, respectively, at 25 °C. The pH of the higher uptake of As (III) onto ATUCS and CS was 4-5 and 8.0, respectively. The results demonstrated improved adsorption of As (III) using ATUCS as compared to the CS.


Assuntos
Arsenazo III/química , Arsenazo III/isolamento & purificação , Quitosana/química , Quitosana/síntese química , Tioureia/química , Descoloração da Água/métodos , Água/química , Adsorção , Técnicas de Química Sintética , Corantes/química , Corantes/isolamento & purificação , Concentração de Íons de Hidrogênio , Cinética , Soluções , Termodinâmica , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
6.
Appl Environ Microbiol ; 84(8)2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29453257

RESUMO

Recently, methanotrophic and methylotrophic bacteria were found to utilize rare earth elements (REEs). To monitor the REE content in culture media of these bacteria, we have developed a rapid screening method using the Arsenazo III (AS III) dye for spectrophotometric REE detection in the low µM (0.1 to 10 µM) range. We designed this assay to follow LaIII and EuIII depletion from the culture medium by the acidophilic verrucomicrobial methanotroph Methylacidiphilum fumariolicum strain SolV. The assay can also be modified to screen the uptake of other REEs, such as PrIII, or to monitor the depletion of LaIII from growth media in neutrophilic methylotrophs such as Methylobacterium extorquens strain AM1. The AS III assay presents a convenient and fast detection method for REE levels in culture media and is a sensitive alternative to inductively coupled plasma mass spectrometry (ICP-MS) or atomic absorption spectroscopy (AAS).IMPORTANCE REE-dependent bacterial metabolism is a quickly emerging field, and while the importance of REEs for both methanotrophic and methylotrophic bacteria is now firmly established, many important questions, such as how these insoluble elements are taken up into cells, are still unanswered. Here, an Arsenazo III dye-based assay has been developed for fast, specific, and sensitive determination of REE content in different culture media. This assay presents a useful tool for optimizing cultivation protocols, as well as for routine REE monitoring during bacterial growth without the need for specialized analytical instrumentation. Furthermore, this assay has the potential to promote the discovery of other REE-dependent microorganisms and can help to elucidate the mechanisms for acquisition of REEs by methanotrophic and methylotrophic bacteria.


Assuntos
Arsenazo III/análise , Técnicas Bacteriológicas/métodos , Meios de Cultura/química , Metais Terras Raras/metabolismo , Methylobacterium extorquens/metabolismo , Verrucomicrobia/metabolismo
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 145: 165-175, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25770966

RESUMO

A new study has been conducted to quantify lanthanide(III) ions using Arsenazo III-polyaminocarboxylic acid (PACA) system. The study disclosed two different analytically important information: (i) λmax of lanthanide-Arsenazo III complexes for lighter lanthanides like Ce(III) and Nd(III) did not shift from its original position on addition of PACA and (ii) for heavier lanthanides like Dy(III), Tm(III) and Lu(III) a new λmax at 538 nm was observed, while wavelengths at 610 nm and 654 nm were disappeared in presence of ethylenediaminetertracetic acid (EDTA) and trans-1,2-Diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA), further the intensity of peak decreased with increase in lanthanide(III) ion concentration. Effect of ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) and N-(2-hydroxyethyl) ethylenediamine-N,N',N'-triacetic acid (EDTA-OH) on Arsenzo(III)-Ln(III) complex is very weak and there is no analytically importance of such interaction. Moreover, this work confirms that Nd(III) and heavy lanthanides can be successfully determined with high accuracy in the working range of concentration of these metal ions.


Assuntos
Arsenazo III/química , Ácidos Carboxílicos/química , Elementos da Série dos Lantanídeos/química , Espectrofotometria/métodos , Ácido Edético/análogos & derivados , Ácido Edético/química , Indicadores e Reagentes , Titulometria
8.
Acta Odontol Scand ; 72(8): 825-30, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24850503

RESUMO

OBJECTIVE: To test the stability of two conventional adhesives when combined with a low-viscosity caries infiltrant used for sealing sound enamel against toothbrush abrasion and acid challenge in vitro. MATERIALS AND METHODS: Bovine enamel discs (Ø = 3 mm) randomly assigned to three groups (n = 10/group) were etched with 37% phosphoric acid for 30 s and treated with resins of different monomer contents forming three test groups: (1) Untreated specimens (Control); (2) Infiltrant (Icon, DMG) + conventional enamel bonding adhesive (Heliobond, Ivoclar Vivadent); and (3) Infiltrant + conventional orthodontic adhesive (Transbond XT Primer, 3M Unitek). All specimens were immersed in hydrochloric acid (pH 2.6) for up to 9 days, during which they were exposed to 1825 toothbrush-strokes per day. Calcium dissolution was assessed using Arsenazo III method at 24-h intervals. Data were analyzed by Kruskal-Wallis and Wilcoxon signed ranks tests. RESULTS: Cumulative calcium dissolution for the untreated specimens (39.75 ± 7.32 µmol/ml) exceeded the sealed groups (Icon + Heliobond: 23.44 ± 7.03 µmol/ml; Icon + Transbond XT Primer: 22.17 ± 5.34 µmol/ml). Untreated specimens presented a relatively constant calcium dissolution rate throughout the experimental period, whereas the sealed groups presented a gradual increase indicating weakening of the seal by toothbrush abrasion. Both sealed groups presented significantly lower daily calcium dissolution at all time points compared to the control, except for Group 2 on the last measurement day. CONCLUSIONS: Low-viscosity caries infiltrant application on sound enamel prior to conventional resin application provided a protective effect against enamel demineralization, but this effect was not stable when challenged mechanically by toothbrush abrasion.


Assuntos
Esmalte Dentário/patologia , Selantes de Fossas e Fissuras/uso terapêutico , Resinas Sintéticas/uso terapêutico , Abrasão Dentária/prevenção & controle , Erosão Dentária/prevenção & controle , Condicionamento Ácido do Dente/métodos , Acrilatos/uso terapêutico , Animais , Arsenazo III , Cálcio/análise , Bovinos , Corantes , Esmalte Dentário/química , Materiais Dentários/química , Ácido Clorídrico/química , Ácidos Fosfóricos/química , Distribuição Aleatória , Cimentos de Resina/uso terapêutico , Solubilidade , Fatores de Tempo , Escovação Dentária/instrumentação
9.
Chemosphere ; 107: 373-378, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24485811

RESUMO

Arsenazo III is a widely used reagent for the concentration measurement of uranium and other actinides in aqueous samples. This study indicates that, for routine aqueous samples, due to the strong complexing ability with Arsenazo III, Fe(III) can significantly decrease the UV-Vis absorbance of the U(VI)-Arsenazo III complex, whereas the influence of Fe(II) on the absorbance is negligible. However, when Fe(II) is present in a gamma-irradiated U(VI) aqueous sample, it can give rise to the Fenton reaction, which produces oxidizing radicals that decompose the subsequently added Arsenazo III, leading to a sharp decrease in the absorbance of the U(VI)-Arsenazo III complex. The decrease in absorbance depends on the iron content and irradiation dose. Furthermore, the oxidizing radicals from the Fenton reaction induced by gamma irradiation can be continually produced. Even if the irradiated solution has been aged for more than one month in the absence of light at room temperature and without the exclusion of oxygen, the reactivity of the radicals did not decrease toward the subsequently added Arsenazo III. This finding demonstrates that the presence of Fe(II) in gamma-irradiated U(VI) aqueous samples can lead to incorrect U(VI) measurement using the Arsenazo III method, and a new method needs to be developed for the quantitative determination of U(VI) in the presence of gamma radiation and ferrous iron.


Assuntos
Arsenazo III/química , Compostos Férricos/química , Compostos Ferrosos/química , Raios gama , Espectrofotometria/métodos , Urânio/análise , Urânio/química , Artefatos , Peróxido de Hidrogênio/química , Ferro/química , Espectrometria de Massas , Água/química
10.
Talanta ; 115: 751-4, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24054658

RESUMO

This work reports a reliable, fast and optimized photometric technique based on the specific chemical complexation of uranyl ion with arsenazo-III. In the case of solid samples (plant samples), for which mineralization under acidic and oxidative conditions was used, addition of ascorbic acid led to stabilization of the arsenazo-uranyl complex over time. The results, in total agreement with data obtained from α and γ spectrometries, demonstrate that the present technique is able to precisely quantify uranium in water as well as in plant samples, within the µg/L and mg/g ranges respectively.


Assuntos
Arsenazo III/química , Quelantes/química , Poluentes Ambientais/análise , Fotometria/métodos , Urânio/análise , Ácido Ascórbico/química , Casca de Planta/química , Pseudotsuga/química , Radioisótopos , Radiometria , Águas Residuárias/química
11.
J Oral Sci ; 55(2): 133-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23748452

RESUMO

The aim of this study was to evaluate the concentrations of calcium (Ca), inorganic phosphate (Pi) and fluoride (F) in carious dentin and in different layers of sound dentin. The samples examined were 52 permanent teeth (26 sound and 26 carious), which were subjected to two experiments to assess the mineral content of: 1) two layers (internal and external) of sound dentin and 2) sound and carious dentin. Ca and Pi were analyzed using a colorimetric method with arsenazo III (C22H18As2N4O14S2) and molybdate reagents, and F was analyzed using a specific electrode. A non-parametric test, the Mann-Whitney test, was used to verify differences between groups. Sound dentin showed a higher concentration of fluoride in the internal layer than in the external layer (P = 0.03), but no inter-layer differences in Ca or Pi concentration were evident. Lower concentrations of Ca, Pi and F were observed in carious dentin than in sound dentin (P < 0.05). The results of this study suggest that the internal layer of sound dentin has a higher fluoride content than the external layer, and that carious dentin has lower concentrations of Ca, Pi and F than sound dentin.


Assuntos
Cárie Dentária/patologia , Dentina/química , Arsenazo III , Cálcio/análise , Colorimetria/métodos , Corantes , Fluoretos/análise , Humanos , Indicadores e Reagentes , Eletrodos Seletivos de Íons , Dente Molar/química , Dente Serotino/química , Molibdênio , Fosfatos/análise
12.
Environ Monit Assess ; 185(2): 1613-26, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22580790

RESUMO

In this work, spectrophotometer was used as a detector for the determination of uranium from water, biological, and ore samples with a flow injection system coupled with solid phase extraction. In order to promote the online preconcentration of uranium, a minicolumn packed with XAD-4 resin impregnated with nalidixic acid was utilized. The system operation was based on U(VI) ion retention at pH 6 in the minicolumn at flow rate of 15.2 mL min(-1). The uranium complex was removed from the resin by 0.1 mol dm(-3) HCl at flow rate of 3.2 mL min(-1) and was mixed with arsenazo III solution (0.05 % solution in 0.1 mol dm(-3) HCl, 3.2 mL min(-1)) and driven to flow through cell of spectrophotometer where its absorbance was measured at 651 nm. The influence of chemical (pH and HCl (as eluent and reagent medium) concentration) and flow (sample and eluent flow rate and preconcentration time) parameters that could affect the performance of the system as well as the possible interferents was investigated. At the optimum conditions for 60 s preconcentration time (15.2 mL of sample volume), the method presented a detection limit of 1.1 µg L(-1), a relative standard deviation (RSD) of 0.8 % at 100 µg L(-1), enrichment factor of 30, and a sample throughput of 42 h(-1), whereas for 300 s of the preconcentration time (76 mL of sample volume), a detection limit of 0.22 µg L(-1), a RSD of 1.32 % at 10 µg L(-1), enrichment factor of 150, and a sampling frequency of 11 h(-1) were reported.


Assuntos
Ácido Nalidíxico/química , Poliestirenos/química , Polivinil/química , Monitoramento de Radiação/métodos , Urânio/análise , Poluentes Radioativos da Água/análise , Arsenazo III/química , Análise de Injeção de Fluxo , Extração em Fase Sólida , Espectrofotometria Atômica , Urânio/química
13.
Clin Oral Investig ; 17(2): 595-600, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22526895

RESUMO

OBJECTIVE: The aim of the study was to evaluate the impact of flow velocity under laminar flow conditions of different acidic solutions on enamel erosion. MATERIAL AND METHODS: A total of 240 bovine enamel specimens were prepared and allocated to 30 groups (n = 8 each). Samples of 18 groups were superfused in a flow chamber system with laminar flow behavior using 1 ml of citric acid or hydrochloric acid (HCl) of pH 2.0, 2.6 or 3.0. Flow rates in the sample chamber were adjusted to 10, 60 or 100 µl/min. To simulate turbulent flow behavior, samples of six groups were immersed in 1 ml of the respective solution, which was vortexed (15 min, 600 rpm). For simulating non-agitated conditions, specimens of the remaining six groups were immersed in 1 ml of the respective solution without stirring. Calcium in the solutions, released from the enamel samples, was determined using Arsenazo III method. RESULTS: For acidic solutions of pH 2.6 and 3.0, erosive potential of citric acid was equivalent to that of HCl at a flow of 100 µl/min. The same observation was made for the samples subjected to turbulent conditions at pH 3. At all other conditions, citric acid induced a significantly higher calcium loss than HCl. CONCLUSION: It is concluded that under slow laminar flow conditions, flow rate variations lead to higher erosive impact of citric acid compared to hydrochloric acid at pH 2.0, but not at pH ≥ 2.6 and increasing laminar flow or turbulent conditions. CLINICAL RELEVANCE: Erosive enamel dissolution under laminar flow conditions is a complex issue influenced by flow rate and acidic substrate.


Assuntos
Cálcio/análise , Ácido Cítrico/farmacologia , Esmalte Dentário/efeitos dos fármacos , Ácido Clorídrico/farmacologia , Erosão Dentária/induzido quimicamente , Animais , Arsenazo III , Bovinos , Esmalte Dentário/química , Hidrodinâmica , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Distribuição Aleatória , Reologia , Fatores de Tempo , Erosão Dentária/metabolismo
14.
Ukr Biokhim Zh (1999) ; 85(5): 27-36, 2013.
Artigo em Ucraniano | MEDLINE | ID: mdl-24479320

RESUMO

The role of inositol-1,4,5-trisphosphate of (IP3)-sensitive Ca2+ channels in Ca2+ homeostasis maintenance under activation of M-cholinergic receptors and P2Y receptors in the secretory cells of the rat lacrimal gland was investigated. The study was carried out on intact and permeabilized secretory cells of exorbital lacrimal glands of rats. The cells were isolated using the modified Herzog, Sides, Miller method (1976) and permeabilized with digitonin (50 mg per 0.5 million cells). The functioning of the Ca(2+)-transport systems was estimated by changes of Ca2+ content in the studied cells, which was determined by the spectrophotometric method using arsenazo III. It was shown that IP3-sensitive Ca2+ channels (IP3Rs) of investigated cells are directly inhibited by 2-APB (10 microM/l). On the other hand, the channels are activated by IP3, cholinomimetic (carbacholine) and purine receptor agonist (ATP). When both M-cholinergic receptors and P2Y receptors were activated Ca2+ was released from the same IP3-sensitive store because the effects of ATP and carbacholine at high concentrations (1mM/l and 10 microM/l, respectively) on the Ca2+ content were non-additive. The presence of the store-operated Ca(2+)-channels in secretory cells of the lacrimal gland is confirmed by the observed increase of cellular Ca2+ content as a result of Ca2+ mobilization from the store by carbacholine or thapsigargin and following restoration of Ca2+ concentration in the extracellular solution.


Assuntos
Células Acinares/metabolismo , Cálcio/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Aparelho Lacrimal/metabolismo , Receptores Colinérgicos/metabolismo , Receptores Purinérgicos P2Y/metabolismo , Células Acinares/citologia , Células Acinares/efeitos dos fármacos , Trifosfato de Adenosina/farmacologia , Animais , Animais não Endogâmicos , Arsenazo III , Transporte Biológico , Compostos de Boro/farmacologia , Cálcio/agonistas , Carbacol/farmacologia , Permeabilidade da Membrana Celular/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Digitonina/farmacologia , Inositol 1,4,5-Trifosfato/farmacologia , Receptores de Inositol 1,4,5-Trifosfato/agonistas , Receptores de Inositol 1,4,5-Trifosfato/antagonistas & inibidores , Aparelho Lacrimal/citologia , Aparelho Lacrimal/efeitos dos fármacos , Cultura Primária de Células , Ratos , Transdução de Sinais , Tapsigargina/farmacologia
15.
Am J Dent ; 26(6): 347-50, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24640440

RESUMO

PURPOSE: This double-blind, crossover study evaluated whole plaque fluoride concentration (F), as well as whole plaque calcium concentrations (Ca) after brushing with a placebo (PD - fluoride free), low-fluoride (LFD, 513 microg F/g) and conventional (CD, 1,072 microg F/g) dentifrices. METHODS: Children (n=20) were randomly assigned to brush twice daily with one of the dentifrices, during 7 days. On the 7th day, samples were collected at 1 and 12 hours after brushing. F and Ca were analyzed with an ion-selective electrode and with the Arsenazo III method, respectively. Data were analyzed by ANOVA, Tukey's test and by Pearson correlation coefficient (P< 0.05). RESULTS: The use of the fluoridated dentifrices significantly increased plaque [F]s 1 hour after brushing when compared to PD, returning to baseline levels 12 hours after. Positive and significant correlations were found between plaque [F] and (Ca) under most of the conditions evaluated. The mean increase in plaque [F] observed 1 hour after brushing with the CD were only about 47% higher than those obtained for the LFD. The use of a LFD promotes proportionally higher increases in plaque [F] when compared to a CD. Plaque F concentrations were also shown to be dependent on plaque Ca concentrations.


Assuntos
Cariostáticos/análise , Placa Dentária/química , Dentifrícios/uso terapêutico , Fluoretos/análise , Arsenazo III , Cálcio/análise , Cariostáticos/administração & dosagem , Cariostáticos/uso terapêutico , Criança , Corantes , Estudos Cross-Over , Dentifrícios/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Fluoretos/administração & dosagem , Fluoretos/uso terapêutico , Humanos , Eletrodos Seletivos de Íons , Placebos , Fatores de Tempo , Escovação Dentária/métodos
17.
Caries Res ; 46(5): 496-506, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22813924

RESUMO

AIM: The prevalence of dental erosion is still increasing. A possible preventive approach might be rinsing with edible oils to improve the protective properties of the pellicle layer. This was tested in the present in situ study using safflower oil. METHODS: Pellicle formation was carried out in situ on bovine enamel slabs fixed buccally to individual upper jaw splints (6 subjects). After 1 min of pellicle formation subjects rinsed with safflower oil for 10 min, subsequently the samples were exposed in the oral cavity for another 19 min. Enamel slabs without oral exposure and slabs exposed to the oral cavity for 30 min without any rinse served as controls. After pellicle formation in situ, slabs were incubated in HCl (pH 2; 2.3; 3) for 120 s, and kinetics of calcium and phosphate release were measured photometrically (arsenazo III, malachite green). Furthermore, the ultrastructure of the pellicles was evaluated by transmission electron microscopy (TEM). RESULTS: Pellicle alone reduced erosive calcium and phosphate release significantly at all pH values. Pellicle modification by safflower oil resulted in an enhanced calcium loss at all pH values and caused an enhanced phosphate loss at pH 2.3. TEM indicated scattered accumulation of lipid micelles and irregular vesicle-like structures attached to the oil-treated pellicle layer. Acid etching affected the ultrastructure of the pellicle irrespective of oil rinsing. CONCLUSION: The protective properties of the pellicle layer against extensive erosive attacks are limited and mainly determined by pH. The protective effects are modified and reduced by rinses with safflower oil.


Assuntos
Película Dentária/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Óleo de Cártamo/farmacologia , Adulto , Animais , Arsenazo III , Cálcio/análise , Bovinos , Corantes , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/ultraestrutura , Película Dentária/química , Película Dentária/ultraestrutura , Humanos , Ácido Clorídrico/farmacologia , Concentração de Íons de Hidrogênio , Lipídeos/química , Teste de Materiais , Micelas , Microscopia Eletrônica de Transmissão , Boca/fisiologia , Fósforo/análise , Fotometria , Corantes de Rosanilina , Erosão Dentária/patologia , Adulto Jovem
18.
Gerodontology ; 29(2): 125-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22117935

RESUMO

OBJECTIVE: The aim of this study was to verify the association between salivary calcium and serum oestrogen levels with oral dryness in post-menopausal women. Also, the correlation between these variables was evaluated. METHODS: A case-control study was carried out on 60 selected menopausal women with and without oral dryness feeling (30 as case and 30 as control) conducted in the Department of Oral Medicine and Radiology, Maharishi Markandeshar University, Mullana, India. Paraffin-stimulated saliva samples were obtained by expectoration. Salivary calcium concentrations were assessed colorimetrically using Arsenazo III reaction. The serum oestrogen concentration was measured using ELISA. Statistical analysis of Student's t-test and Pearson correlation was used. RESULTS: There was significant difference in mean values of both salivary calcium concentration and serum oestrogen between case and control groups. The result obtained also showed that an inverse correlation was found between salivary calcium concentration and serum oestrogen levels in both the groups and in total sample size. CONCLUSION: Oral dryness in post-menopausal women is associated with high levels of salivary calcium and low levels of serum oestrogen. The concentrations of salivary calcium and serum oestrogen are inversely correlated in post-menopausal women, regardless of the presence or absence of oral dryness.


Assuntos
Cálcio/análise , Estrogênios/sangue , Pós-Menopausa/sangue , Saliva/química , Xerostomia/sangue , Idoso , Arsenazo III , Estudos de Casos e Controles , Colorimetria , Corantes , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa/metabolismo , Saliva/metabolismo , Taxa Secretória/fisiologia , Xerostomia/metabolismo
19.
Methods Mol Biol ; 698: 215-30, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21431522

RESUMO

One of the most noteworthy characteristics of mesenchymal stem cells (MSCs) is their ability to differentiate into osteoblasts in vitro and in vivo. In vitro, this is easily achieved by culturing in the appropriate induction medium. It is because of the reliability and ease of this process that osteogenic differentiation has become a popular assay for the demonstration of MSC plasticity. Although the conditions required for inducing osteogenic differentiation by MSCs typically do not vary particularly between investigators, many methods are employed to measure the extent of differentiation. These methods include, but are not limited to, reverse transcriptase PCR (RT-PCR) for detection of osteogenic transcripts, enzyme linked immunosorbent assay (ELISA) for secreted protein markers, colorimetric assays for osteogenic enzymes, and direct staining of matrix components. This chapter reviews the protocols most commonly utilized for the evaluation of osteogenic differentiation for cultured MSCs.


Assuntos
Técnicas de Cultura de Células , Diferenciação Celular , Células-Tronco Mesenquimais/citologia , Osteogênese , Fosfatase Alcalina/metabolismo , Antraquinonas/metabolismo , Arsenazo III/metabolismo , Contagem de Células , DNA/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Células-Tronco Mesenquimais/metabolismo , Minerais/metabolismo , Nitrofenóis/metabolismo , Compostos Organofosforados/metabolismo , Osteoprotegerina/metabolismo , Coloração e Rotulagem
20.
Nucl Med Biol ; 36(4): 395-402, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19423007

RESUMO

INTRODUCTION: Antibodies covalently conjugated with chelators such as 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) are required for radioimmunoscintigraphy and radioimmunotherapy, which are of growing importance in cancer medicine. METHOD: Here, we report a suite of simple methods that provide a preclinical assessment package for evaluating the effects of DOTA conjugation on the in vitro and in vivo performance of monoclonal antibodies. We exemplify the use of these methods by investigating the effects of DOTA conjugation on the biochemical properties of the DAB4 clone of the La/SSB-specific murine monoclonal autoantibody, APOMAB, which is a novel malignant cell death ligand. RESULTS: We have developed a 96-well microtiter-plate assay to measure directly the concentration of DOTA and other chelators in antibody-chelator conjugate solutions. Coupled with a commercial assay for measuring protein concentration, the dual microtiter-plate method can rapidly determine chelator/antibody ratios in the same plate. The biochemical properties of DAB4 immunoconjugates were altered as the DOTA/Ab ratio increased so that: (i) mass/charge ratio decreased; (ii) hydrodynamic radius increased; (iii) antibody immunoactivity decreased; (iv) rate of chelation of metal ions and specific radioactivity both increased and in vivo, (v) tumor uptake decreased as nonspecific uptake by liver and spleen increased. CONCLUSION: This simplified suite of methods readily identifies biochemical characteristics of the DOTA-immunoconjugates such as hydrodynamic diameter and decreased mass/charge ratio associated with compromised immunotargeting efficiency and, thus, may prove useful for optimizing conjugation procedures in order to maximize immunoconjugate-mediated radioimmunoscintigraphy and radioimmunotherapy.


Assuntos
Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacocinética , Quelantes/química , Quelantes/farmacologia , Imunoconjugados/química , Imunoconjugados/farmacocinética , Animais , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Arsenazo III/química , Autoantígenos/imunologia , Linhagem Celular Tumoral , Quelantes/análise , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Compostos Heterocíclicos com 1 Anel/análise , Compostos Heterocíclicos com 1 Anel/química , Compostos Heterocíclicos com 1 Anel/farmacologia , Humanos , Imunoconjugados/imunologia , Metais/química , Camundongos , Fatores de Tempo , Distribuição Tecidual/efeitos dos fármacos
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