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1.
PLoS One ; 15(3): e0229595, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119700

RESUMO

OBJECTIVES: To assess and compare the enamel surface quality after interproximal enamel reduction (IPR) was performed with different systems and to study the relation between acid penetration depth and enamel surface quality as well as the importance of remineralization. METHODS: Sixty-five extracted teeth were randomly allocated to five experimental groups: untreated control, manual with New Metal Strips, mechanical with oscillating segment (OS) discs, Safe-Tipped Bur Kit, and the Ortho-Strip, followed by 30 s of polishing with the Softflex system and the Compo-system after treating the tooth with OS discs. Mesial surfaces were demineralized for 24 h and distal surfaces were subjected to interchanging demineralization and remineralization cycles of 24 h each for 18 days. The analysis was carried out by profilometry, scanning electron microscopy, and polarization microscopy. RESULTS: After IPR and polishing, enamel roughness was reduced for all systems tested except for the Essix Safe-Tipped Bur Kit. Subsequent demineralization increased enamel roughness in all groups except controls beyond the original level prior to IPR except for IPR with New Metal Strips or Ortho-Strips and subsequent polishing. Cyclic demineralization and remineralization for 18 days yielded a reduction in acid penetration depth and an increase in surface smoothness, which correlated with each other only for controls and treatment with New Metal Strips or Ortho-Strips. CONCLUSIONS: Manual IPR, using New Metal Strips and, even more, the oscillating IPR system Ortho-Strips, yielded smoother interproximal enamel surfaces and less acid penetration depth than the IPR systems with OS discs and the Safe-Tipped Bur Kit after polishing and 18 days of cyclic demineralization and remineralization. Irrespective of the IPR procedure, proper remineralization of IPR-treated surfaces is advisable to reduce caries susceptibility.


Assuntos
Esmalte Dentário/fisiologia , Corrosão Dentária/métodos , Humanos , Microscopia Eletrônica de Varredura , Microscopia de Polarização , Propriedades de Superfície , Dente/fisiologia
2.
Talanta ; 206: 120246, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514901

RESUMO

We develop a novel label-free liquid crystal (LC) aptasensor based on intrinsic properties of nematic LCs for ultra-sensitive detection of tetracycline. The aptasensor is assembled by immobilizing aptamers onto the glass slide modified with both homeotropic alignment and silane coupling agents. Designed aptasensor makes use of the target-induced aptamer conformational switching and disruption of the orientation of LCs which lead to an obvious change of the optical appearance from a dark to a bright response. We describe the optimized condition for maintaining the homeotropic orientation of LCs, which are suitable for the tetracycline detection. The average gray-scale intensities of polarizing optical microscopy images were calculated to quantitatively detect tetracycline concentrations. The aptasensor works especially at trace level of tetracycline as low as 0.5 pM. Moreover, the LC aptasensor was successfully used to detect tetracycline in the real milk sample. According to the results, the proposed LC aptasensor for tetracycline detection is simple, ultra-sensitive, label free and ease of preparation.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , DNA/química , Cristais Líquidos/química , Tetraciclina/análise , Animais , Antibacterianos/análise , Compostos de Bifenilo/química , Contaminação de Alimentos/análise , Ácidos Nucleicos Imobilizados/química , Limite de Detecção , Microscopia de Polarização/métodos , Leite/química , Nitrilos/química
3.
Appl Opt ; 58(35): 9577-9584, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31873556

RESUMO

We introduce an iterative method for designing optical phantoms that are able to replicate the depolarization profiles of various target media, including colloidal suspensions of Intralipid, bovine milk, and ex vivo samples of ovine kidney cortex tissue. The designed phantoms comprise spherical scattering particles with fine-tuned size distributions and are capable of simultaneously reproducing spatially resolved intensity measurements and depolarization measurements of target media when illuminated with circularly polarized light.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Córtex Renal/diagnóstico por imagem , Microscopia de Polarização/métodos , Leite/diagnóstico por imagem , Imagens de Fantasmas , Animais , Bovinos , Luz , Espalhamento de Radiação , Ovinos
4.
Indian J Dent Res ; 30(5): 731-735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31854364

RESUMO

Introduction: Collagen forms an integral part of connective tissue and maintains its structural integrity. It has natural birefringence which is attributed to the arrangement of its fibers and is enhanced by special stains such as picrosirius red through polarizing microscopy. The polarization colors differ according to the fiber thickness and pattern of arrangement which in turn related to aggressiveness. Hence, the present study was conducted to evaluate collagen fibers in keratocystic odontogenic tumor (KCOT) and ameloblastoma using polarizing microscopy. Aim: This study aims to compare and correlate different types and patterns of collagen fibers in KCOT and ameloblastoma using picrosirius red stain under polarizing microscopy to delineate their aggressiveness. Materials and Methods: The color, thickness, and orientation of collagen fibers in the KCOTs (n = 15) and ameloblastomas (n = 15) were studied histochemically by staining the sections with picrosirius red and examined under polarizing microscope using image analyzer software. Results: When collagen fiber bundles in KCOT and ameloblastoma were compared, significant difference was noted between yellowish-orange collagen fiber bundles, but no significant difference was observed between greenish-yellow and orange-red collagen bundles. With respect to orientation and organization, the results are statistically significant (P < 0.05). Conclusion: The connective tissue stroma of KCOT could be regarded not just as a structural support but as a functional part of the lesion. In KCOT, the thin, parallel, and loosely arranged greenish-yellow collagen fibers may be attributed to its high recurrence rate and biological aggressiveness.


Assuntos
Ameloblastoma , Tumores Odontogênicos , Colágeno , Corantes , Humanos , Microscopia de Polarização
5.
Opt Express ; 27(24): 35427-35436, 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31878714

RESUMO

A new strategy is reported here to monitor the enzymatic reactions in real time by using whispering gallery mode (WGM) lasing. The optical microcavity is formed via the self-assembly of an ultraviolet (UV)-treated nematic liquid crystal (LC) 4-cyano-4'-pentylbiphenyl (5CB). The single UV-treated 5CB microdroplet serves as both optical resonator and sensing reactor. The microdroplet configuration transitions induced wavelength shift in the WGM lasing spectra can be used as an indicator for the enzymatic reaction. The proposed sensor has a sub-microgram detection limit of urease (∼0.5 µg/ml), which is lower than the detection limit of currently available urease sensor based on LC materials. Our experimental results demonstrate that WGM lasing has unique advantages in the real-time monitoring of enzymatic reactions compared, for instance, with observation of the optical appearance under a polarized optical microscope.


Assuntos
Sistemas Computacionais , Lasers , Urease/metabolismo , Concentração de Íons de Hidrogênio , Processamento de Imagem Assistida por Computador , Microscopia de Polarização , Fatores de Tempo , Raios Ultravioleta
6.
Biomed Res Int ; 2019: 9101642, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781651

RESUMO

Objective: This in vitro study is aimed at investigating the caries preventive effectiveness of 445 nm diode laser in combination with topical fluoridation. Materials and methods: A total of 30 caries-free bovine teeth were used in this study. Eighteen teeth were covered with nail varnish except four windows on the labial surface. The windows were assigned to no treatment/control (C), laser (L) (0.3 W, 60 s, and 90 J/cm2), fluoride (F), and fluoride followed by laser (FL) treatment groups. Artificial caries lesions were created, and the teeth were sectioned and investigated under polarized light microscopy for quantitative measurement of the resulted lesion depth. Ten teeth were used for surface temperature measurement and two teeth for scanning electron microscopy (SEM). Extra twelve human molars were used for the intrapulpal temperature measurement. The absorbance of fluoride at 445 nm was measured. Results: The means of lesion depth for the C, L, F, and FL groups were 123.48 (±21.93), 112.33 (±20.42), 99.58 (±30.68), and 89.03 (±30.38) µm, respectively. The pairwise differences of the L, F, and FL groups compared with the C group were significant (p < 0.05). The differences between groups were tested: FL versus L p=0.02, F versus L p=0.16, and FL versus F p=0.91, and the difference of the F versus FL was not significant (p=0.91). Temperature increment at the enamel surface and pulp roof were ∆T = 16.67 (±4.11) and 2.12 (±0.66)°C, respectively. The topical fluoride absorbance at 445 nm is five orders higher than that at 810 nm. SEM shows that after laser irradiation the enamel surface was intact and without thermal damage. Conclusions: The 445 nm laser irradiation may be useful for caries prevention, and its effectiveness is lower than those previously achieved using the argon ion laser.


Assuntos
Cárie Dentária/prevenção & controle , Fluoretos Tópicos/uso terapêutico , Lasers Semicondutores/uso terapêutico , Terapia com Luz de Baixa Intensidade , Animais , Bovinos , Cárie Dentária/tratamento farmacológico , Cárie Dentária/radioterapia , Suscetibilidade à Cárie Dentária , Esmalte Dentário/ultraestrutura , Polpa Dentária/ultraestrutura , Humanos , Microscopia Eletrônica de Varredura , Microscopia de Polarização , Dente Molar/ultraestrutura , Temperatura , Dente/ultraestrutura
7.
Nat Commun ; 10(1): 4694, 2019 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619676

RESUMO

Fluorescence polarization microscopy images both the intensity and orientation of fluorescent dipoles and plays a vital role in studying molecular structures and dynamics of bio-complexes. However, current techniques remain difficult to resolve the dipole assemblies on subcellular structures and their dynamics in living cells at super-resolution level. Here we report polarized structured illumination microscopy (pSIM), which achieves super-resolution imaging of dipoles by interpreting the dipoles in spatio-angular hyperspace. We demonstrate the application of pSIM on a series of biological filamentous systems, such as cytoskeleton networks and λ-DNA, and report the dynamics of short actin sliding across a myosin-coated surface. Further, pSIM reveals the side-by-side organization of the actin ring structures in the membrane-associated periodic skeleton of hippocampal neurons and images the dipole dynamics of green fluorescent protein-labeled microtubules in live U2OS cells. pSIM applies directly to a large variety of commercial and home-built SIM systems with various imaging modality.


Assuntos
Actinas/ultraestrutura , Citoesqueleto/ultraestrutura , DNA/ultraestrutura , Microscopia de Fluorescência/métodos , Microscopia de Polarização/métodos , Miosinas/ultraestrutura , Neurônios/ultraestrutura , Animais , Bacteriófago lambda/genética , Linhagem Celular Tumoral , Hipocampo/citologia , Humanos , Rim , Camundongos
8.
Indian J Pathol Microbiol ; 62(4): 537-543, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31611436

RESUMO

Background: Oral submucous fibrosis (OSMF), a well-recognized oral potentially malignant disorder, results due to increased collagen production and reduced collagen degradation. Aims and Objectives: To qualitatively compare the staining properties of collagen in OSMF using two special stains based on their birefringent property using polarizing microscopy. The study also assessed the distribution and orientation of collagen fibers in different grades of OSMF. Materials and Methods: A total of 73 subjects with different clinical and histopathological staging of OSMF comprised the study population. Histopathological examination was done using hematoxylin and eosin stain, Van Gieson and picrosirius red. Collagen fibers were analyzed for polarization colors, distribution, and orientation. Results: Picrosirius red stained both thick and thin collagen fibers. Irrespective of the histopathological grades reddish orange and yellowish orange were the most predominant colors. Parallel arrangement of fibers was observed when stained with Van Gieson but picrosirius red stained sections showed a majority of parallel type I fibers with perpendicular type III fibers which increased with advancement in the histopathological grade. Yellowish orange and greenish yellow fibers were predominant in the lamina propria, while reddish orange fibers were predominant in the submucosa. Conclusion: Picrosirius red was found to be a better stain. Histopathological grading and polarization colors showed no association with each other. Collagen fibers were more thickly and tightly packed in the submucosa indicating that the process of fibrosis began there. The increase in perpendicular type III fibers with advancing histopathological grades suggested their role in fibrosis.


Assuntos
Colágeno/ultraestrutura , Corantes/química , Microscopia de Polarização/métodos , Fibrose Oral Submucosa/patologia , Coloração e Rotulagem , Cor , Humanos
9.
Nat Struct Mol Biol ; 26(9): 802-807, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31488909

RESUMO

Conformational changes within typical protein molecules are rapid and small, making their quantitative resolution challenging. These changes generally involve rotational motions and may thus be resolved by determining changes in the orientation of a fluorescent label that assumes a unique orientation in each conformation. Here, by analyzing fluorescence intensities collected using a polarization microscope at a rate of 50 frames per second, we follow the changes of 10-16° in the orientation of a single bifunctional rhodamine molecule attached to a regulator of conductance to K+ (RCK) domain of the MthK channel, and thus, the transitions between its three conformational states, with effective standard deviation (σ) of 2-5°. Based on available crystal structures, the position of the fluorophore's center differs by 3.4-8.1 Å among the states. Thus, the present approach allows the resolution of protein conformational changes involving ångström-scale displacements.


Assuntos
Polarização de Fluorescência , Methanobacterium/enzimologia , Canais de Potássio Cálcio-Ativados/química , Canais de Potássio Cálcio-Ativados/metabolismo , Conformação Proteica , Microscopia de Polarização
10.
Int J Exp Pathol ; 100(4): 208-221, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31515863

RESUMO

Congo red was discovered to stain amyloid by accident in 1922, and Congo red-stained amyloid was shown to be birefringent on polarization microscopy in 1927. Colours, namely green and yellow, were reported under these conditions in 1945, although these are only two of various anomalous colours that may be seen, depending on the optical set-up. In 1953 there began a dogmatic insistence that in Congo red-stained amyloid between crossed polarizer and analyser green alone should be seen, and the finding of any other colour was a mistake. The idea that green, and only green, is essential for the diagnosis of amyloid has persisted almost universally, and virtually all mentions of Congo red-stained amyloid say that it just shows "green birefringence" or "apple-green birefringence." This idea is wrong and is contrary to everyday experience, because green is seldom seen on its own under these conditions of microscopy, and often, there is no green at all. How observers maintain this unscientific position is explained by a study of its historical origins. Most of the early literature was in German or French and was usually quoted in English at second hand, which meant that misquotations, misattributions and misunderstandings were common. Few workers reported their findings accurately, hardly any attempted to explain them, and until 2008, none gave a completely satisfactory account of the physical optics. The history of Congo red-stained amyloid is an instructive example of how an erroneous belief can become widely established even when it is contradicted by simple experience.


Assuntos
Amiloide , Vermelho Congo/história , Patologia/história , Birrefringência , Diagnóstico por Imagem , História do Século XX , Humanos , Microscopia de Polarização
11.
Molecules ; 24(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438540

RESUMO

A Schiff base supramolecular 4-[(4-(hexyloxy)phenylimino)methyl]benzoic acid and a new series of Schiff base/ester linkages named 4-substitutedphenyl 4-[(4-(hexyloxy)phenylimino)methyl]benzoate liquid crystals were synthesized. The thermal stability, mesomorphic, and optical behavior of the prepared compounds were characterized by differential scanning calorimetry (DSC), Thermogravemetric analysis (TGA), polarized optical microscopy (POM), and UV spectroscopy. FT-IR, 1H-NMR, 13C-NMR, and elemental analyses were carried out to elucidate and confirm the molecular structures of the synthesized compounds. The investigated series comprising different sized terminal polar groups changed between CH(CH3)2, H, I, and F. It was found that the supramolecular imino acid dimer is enantiotropic dimorphic, with a wide SmA phase and a good N phase range. The other series of terminally substituted Schiff base/esters are mesomorphic with a high thermal stable SmA phase, except the iodo derivative, which showed dimorphic SmA and N phases. The effect of the position and the orientation of the cores, as well as the terminal substituent of the type and the stability of the mesophase, were studied. A computational theoretical study of the effects of the van der Waal's volume, the Hammett substituent coefficient, the inductive sigma constant, and other geometrical parameters were discussed. The study revealed that the planarity of the two phenyl rings attached with an imino linking group impacted the resonance effect of the terminal substituents rather than their inductive effect. A detailed study on the effect of the estimated thermal parameters, as well as their geometrical planarity with the type and stability of the formed mesophase, was discussed.


Assuntos
Cristais Líquidos/química , Bases de Schiff/química , Varredura Diferencial de Calorimetria , Espectroscopia de Ressonância Magnética , Microscopia de Polarização , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
12.
Braz Oral Res ; 33: e060, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31365705

RESUMO

This study evaluated the effect of hypertension on tissue response and biomineralization capacity of white Mineral Trioxide Aggregate (MTA), High-plasticity MTA (MTA HP), and Biodentine® (BDT) in rats. Polyethylene tubes filled with MTA, MTA HP, BDT, and the control group (empty tubes) were placed into the dorsal subcutaneous tissue of 32 male rats (16 normotensive (NT) and 16 hypertensive rats - 8 per group). After 7 and 30 days, the polyethylene tubes surrounded by connective tissue were removed, fixed, and embedded in histological resin. The mean number of inflammatory cells was estimated in HE-stained sections, biomineralization was quantified as area (µm2) by Kossa (VK) staining, and examination by polarized light (LP) microscopy was performed. The differences amongst the groups were analyzed statistically by the Mann-Whitney or Student's t test, according to Shapiro-Wilk test of normality (p < 0.05). The inflammatory responses to all materials were greater in hypertensive rats than in NT rats (p < 0.05). Positive VK staining in MTA and BDT were more pronounced in NT rats at 7 and 30 days (p < 0.05). Birefringent structures in LP for MTA, MTA HP, and BDT were more pronounced in NT rats at 7 days (p<0.05). In rats, hypertension was able to increase inflammatory infiltrate and decrease biomineralization of the tested materials.


Assuntos
Compostos de Alumínio/farmacologia , Materiais Biocompatíveis/farmacologia , Biomineralização/fisiologia , Compostos de Cálcio/farmacologia , Hipertensão/fisiopatologia , Óxidos/farmacologia , Silicatos/farmacologia , Tela Subcutânea/efeitos dos fármacos , Tela Subcutânea/fisiopatologia , Animais , Combinação de Medicamentos , Hipertensão/complicações , Inflamação/patologia , Inflamação/fisiopatologia , Masculino , Teste de Materiais , Microscopia de Polarização , Ratos Wistar , Reprodutibilidade dos Testes , Tela Subcutânea/patologia , Fatores de Tempo
13.
Pak J Pharm Sci ; 32(3): 981-986, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31278710

RESUMO

Polymorphism occurs in pharmaceutical compounds affect to the physicochemical quality and goal of therapy. Thus, quality evaluation of different crystal forms should be assessed especially the solubility and dissolution behaviors among polymorphic forms, which correlate to bioavailability and therapy efficacy. To achieved the different of a polymorph various solvent were used such as acetonitrile, methanol, ethyl acetate, acetone, water, n-hexane, and n-heptane. All of the crystal modification resulted were characterized by a polarization light microscopy (PLM), Fourier-Transform Infrared (FTIR) differential scanning calorimetry (DSC) and powdered X-ray diffraction (PXRD). Besides that, nature of solubility in water (24 and 48 hours test times) and particulate dissolution profile (an hour test) were carried out. There were various polymorphs success resulted and have significant differences in morphology, definite spectral fingerprints, crystal structure and thermal behavior. From the solubility of the samples found the top three highest soluble forms i.e. Form 6, 2 and 3, respectively. But there are showed became in order reverse performance after 60 minutes dissolution (Form 3, 2 and 6, respectively). The polymorphic forms of EFV were successful to obtained by the solvents treatment. Therefore, the physicochemical properties of polymorphic forms from active pharmaceutical ingredients (APIs) should be carefully considered in dosage forms pre-formulation approaches.


Assuntos
Benzoxazinas/química , Solventes/química , Acetona/química , Acetonitrilos/química , Varredura Diferencial de Calorimetria , Cristalização , Hexanos/química , Metanol/química , Microscopia de Polarização , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química , Difração de Raios X
14.
Am J Clin Pathol ; 152(5): 590-607, 2019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31305893

RESUMO

OBJECTIVES: Genital talc use is associated with increased risk for ovarian carcinoma in epidemiologic studies. Finding talc in pelvic tissues in women with ovarian carcinoma who have used talc is important in documenting exposure and assessing talc's biologic potential, but tissue-based morphology studies have been rarely reported. METHODS: We report five patient cases with documented perineal talc use, each of whom had talc (by both polarized light and scanning electron microscopy) in multiple pelvic sites distant from the perineum. Six negative-exposure control patients were also analyzed. RESULTS: Talc particles were found in exposed patients, typically within two or more of the following locations: pelvic region lymph nodes, cervix, uterine corpus, fallopian tubes, and ovaries. CONCLUSIONS: Our report adds new insights into the biologic potential of talc and suggests additional anatomic sites that should be closely examined for talc by oncologic surgical pathologists in the setting of perineal talc use.


Assuntos
Genitália Feminina/metabolismo , Neoplasias Ovarianas/metabolismo , Pelve , Períneo , Talco/farmacocinética , Adenocarcinoma de Células Claras/metabolismo , Carcinoma Endometrioide/metabolismo , Cistadenocarcinoma Seroso/metabolismo , Feminino , Genitália Feminina/química , Humanos , Linfonodos/química , Linfonodos/metabolismo , Microscopia Eletrônica de Varredura , Microscopia de Polarização , Pessoa de Meia-Idade , Neoplasias Ovarianas/induzido quimicamente , Talco/efeitos adversos , Talco/análise , Útero/química , Útero/metabolismo
15.
Mikrochim Acta ; 186(7): 443, 2019 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-31197484

RESUMO

The work describes a simplified method for the preparation of liquid crystal (LC) bioassay using DNA-based capture molecules and having lower detection limits. The capture DNA probes of the stem-loop structure were immobilized on the surface of a glass slide. A homeotropic orientation of LC molecules can be obtained with the proper surface coverage of capture DNA probes. In the presence of analytes (specifically shown here for the progesterone as a model analyte), the molecular binding between capture DNA probes and progesterone opens the loop of the capture DNA probes. The opened sequence is then amenable to hybridization with a reporter DNA probe that is immobilized on gold nanoparticles. This changes the surface microstructure, disrupts the orientation of LC molecules, and results in an enhanced optical response, expressed as the average grey value of the images. This new kind of surface treatment for simultaneous recognition of target molecules and homeotropic anchoring of LCs reduces the number of preparation steps and makes the process of LC bioassay easier. This method has a detection limit as low as 0.1 pmol·L-1 of progesterone. Graphical abstract Schematic presentation of the liquid crystal-based DNA assay. DMOAP: Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride; TEA: Triethoxsilylbutyraldehyde; 5CB: 4-cyano-4'-pentylbiphenyl; P4: progesterone.


Assuntos
DNA/química , Cristais Líquidos/química , Microscopia de Polarização/métodos , Progesterona/sangue , DNA/genética , DNA/metabolismo , Sondas de DNA/química , Sondas de DNA/genética , Sondas de DNA/metabolismo , Ouro/química , Humanos , Ácidos Nucleicos Imobilizados/química , Ácidos Nucleicos Imobilizados/genética , Sequências Repetidas Invertidas , Limite de Detecção , Nanopartículas Metálicas/química , Progesterona/metabolismo , Estudo de Prova de Conceito
16.
Braz Oral Res ; 33: e044, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31141037

RESUMO

The aim of this study was to evaluate soluble and insoluble fluoride concentrations in commercial varnishes, and their remineralization effect on artificial caries enamel lesions using surface and cross-sectional microhardness evaluations. Forty bovine enamel blocks were separated into four groups (n=10): control (no treatment), Enamelast (Ultradent Products), Duraphat (Colgate-Palmolive) and Clinpro White Varnish (3M ESPE). Surface enamel microhardness evaluations were obtained, artificial enamel caries lesions were developed by dynamic pH-cycling, and the varnishes were then applied every 6 days, after which the enamel blocks were submitted to dynamic remineralization by pH cycles. After removal of the varnishes, the enamel surfaces were reassessed for microhardness. The blocks were sectioned longitudinally, and cross-sectional microhardness measurements were performed at different surface depths (up to 300 µm depth). Polarized light microscopy images (PLMI) were made to analyze subsurface caries lesions. The fluoride concentration in whole (soluble and insoluble fluoride) and centrifuged (soluble fluoride) varnishes was determined using an extraction method with acetone. The data were analyzed to evaluate the surface microhardness, making adjustments for generalized linear models. There was a significant decrease in enamel surface microhardness after performing all the treatments (p<0.0001). Enamelast and Duraphat showed significantly higher enamel microhardness values than the control and the Clinpro groups (p = 0.0002). Microhardness loss percentage was significantly lower for Enamelast (p = 0.071; One-way ANOVA). PLMI showed that subsurface caries lesions were not remineralized with the varnish treatments. No significant differences in the in-depth microhardness levels (p = 0.7536; ANOVA) were observed among the treatments. Enamelast presented higher soluble and insoluble fluoride concentrations than the other varnishes (p < 0.0001; Kruskal-Wallis and Dunn tests). Enamelast and Duraphat varnishes promoted enamel surface remineralization, but no varnish remineralized the subsurface lesion body. Although insoluble and soluble fluoride concentration values did not correspond to those declared by the manufacturer, Enamelast presented higher fluoride concentration than the others.


Assuntos
Cariostáticos/química , Cárie Dentária/tratamento farmacológico , Esmalte Dentário/efeitos dos fármacos , Fluoretos Tópicos/química , Remineralização Dentária/métodos , Análise de Variância , Animais , Bovinos , Testes de Dureza , Teste de Materiais , Microscopia de Polarização , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Propriedades de Superfície/efeitos dos fármacos , Fatores de Tempo
17.
Int J Dev Biol ; 63(3-4-5): 235-244, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31058300

RESUMO

In recent years, we have witnessed an unprecedented advancement of light microscopy techniques which has allowed us to better understand biological processes occurring during oogenesis and early embryonic development in mammals. In short, two modes of cellular imaging are now available: those involving fluorescent labels and those which are fluorophore-free. Fluorescence microscopy, in its various forms, is used predominantly in research, as it provides detailed information about cellular processes; however, it can involove an increased risk of photodamage. Fluorophore-free techniques provide, on the other hand, a smaller amount of biological data but they are safer for cells and therefore can be potentially used in a clinical setting. Here, we review various fluorescence and fluorophore-free visualisation approaches and discuss their applicability in developmental biology and reproductive medicine.


Assuntos
Blastocisto/citologia , Microscopia de Fluorescência/métodos , Microscopia/métodos , Desenvolvimento Embrionário/fisiologia , Microscopia de Fluorescência/efeitos adversos , Microscopia de Polarização/métodos , Oócitos/citologia
18.
PLoS One ; 14(5): e0214494, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31095594

RESUMO

We introduce a Mueller-matrix imaging polarization-based approach for the quantitative digital screening of the polycrystalline structure of fibrillary-based biological tissues in vitro. The morphometric evaluation of histological sections of myocardium was performed utilizing the high-order statistical moments calculated based on the spatial distribution of linear and circular birefringence and dichroism obtained experimentally. We demonstrate that spatial distributions of phase of light and optical anisotropy of scattering inherent to fibrillar networks of myocardium at different necrotic stages can be effectively used as a quantitative marker of stages of myosin fibril degradation. Processing the images of phase of light scattered in biological tissues with high order statistical analysis provides a functional tool for the quantitative characterization of necrotic conditions of the myocardium.


Assuntos
Anisotropia , Miocárdio/metabolismo , Algoritmos , Birrefringência , Microscopia de Polarização/métodos , Miosinas/metabolismo
19.
Ann Diagn Pathol ; 40: 136-142, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31077875

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease with a dismal prognosis and an unknown etiology. Inorganic dust is a known risk factor, and air pollution seems to affect disease progression. We aimed to investigate inorganic particulate matter in IPF lung tissue samples. Using polarizing light microscopy, we examined coal dust pigment and inorganic particulate matter in 73 lung tissue samples from the FinnishIPF registry. We scored the amount of coal dust pigment and particulate matter from 0 to 5. Using energy dispersive spectrometry with a scanning electron microscope, we conducted an elemental analysis of six IPF lung tissue samples. We compared the results to the registry data, and to the population density and air quality data. To compare categorical data, we used Fisher's exact test; we estimated the survival of the patients with Kaplan-Meier curves. We found inorganic particulate matter in all samples in varying amounts. Samples from the southern regions of Finland, where population density and fine particle levels are high, more often had particulate matter scores from 3 to 5 than samples from the northern regions (31/50, 62.0% vs. 7/23, 30.4%, p = 0.02). The highest particulate matter scores of 4 and 5 (n = 15) associated with a known exposure to inorganic dust (p = 0.004). An association between particulate matter in the lung tissue of IPF patients and exposure to air pollution may exist.


Assuntos
Poluição do Ar/efeitos adversos , Fibrose Pulmonar Idiopática/patologia , Material Particulado , Idoso , Poeira , Feminino , Humanos , Pulmão/patologia , Masculino , Microscopia Eletrônica de Varredura , Microscopia de Polarização , Pessoa de Meia-Idade , Densidade Demográfica , Fatores de Risco
20.
J Glaucoma ; 28(4): e64-e65, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30946278

RESUMO

PURPOSE: To describe an unusual case of glaucoma drainage tube blockage. PATIENTS: A 76-year-old woman presented with left endothelial graft failure. Her previous ocular history included primary open-angle glaucoma diagnosed for 15 years and Fuch's endothelial dystrophy. Three years before presentation, the left eye required a Descemet stripping endothelial keratoplasty followed by a trabeculectomy with mitomycin C and subsequent Baerveldt tube insertion 3 years previously. Intraocular pressures were right 9 and left 19 mm Hg. The endothelial graft demonstrated supra-temporal edema, in proximity to the sulcus placed tube tip. METHODS: A repeat endothelial keratoplasty was undertaken. During surgery, an attempt to flush the tube ab internally with balanced salt solution on a 27-G Rycroft cannula, resulted in extrusion of a long translucent tubular plug from within the silicone tube into the anterior chamber. This was removed with intraocular forceps and sent for histopathology. The endothelial keratoplasty was performed and an air bubble placed in the anterior chamber. RESULTS: The histopathology was reported as fibrinohemorrhagic material associated with refractile material, detected under polarized light microscopy. At 6 months follow-up, the graft was clearing well, the tube in situ and the intraocular pressure 6 mm Hg. CONCLUSIONS: One possible cause of the refractile material within the specimen is spalled particles of silicone, presumably from the tube. This finding potentially questions the long-term stability of silicone products in the eye and may be a cause of capsular fibrosis around the glaucoma drainage device plate.


Assuntos
Implantes para Drenagem de Glaucoma , Glaucoma de Ângulo Aberto/cirurgia , Intubação/instrumentação , Falha de Prótese , Idoso , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior , Feminino , Distrofia Endotelial de Fuchs/cirurgia , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/cirurgia , Humanos , Pressão Intraocular/fisiologia , Microscopia de Polarização , Implantação de Prótese , Reoperação , Acuidade Visual/fisiologia
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