Antimicrobial Efficacy and Dentin Collagen Damage Caused by Calcium Hypochlorite and Sodium Hypochlorite

Abstract This study aimed to evaluate the antimicrobial activity of calcium hypochlorite (Ca (OCl)2) and sodium hypochlorite (NaOCl) using confocal laser scanning microscopy (CLSM) and dentin organic matrix alteration by picrosirius staining and light microscopy (LM). Samples of human extracted teeth were infected with Enterococcus faecalis by centrifugation of the bacterial suspension and were treated with Ca(OCl)2 or NaOCl at 0.5%, 2.5%, and 6% for 15, 30, and 60 seconds. CLSM and viability staining were used to quantitatively analyze the proportions of dead/live bacteria in the canal lumen and border of the root canal. The data were analyzed by ANOVA and Fisher test. For LM analysis, one hundred bovine teeth were randomly divided into 10 test groups (n=10): G1- Without treatment; G2- 17% EDTA; G3- 6% NaOCl; G4- 6% NaOCl + EDTA; G5- 0.5% Ca(OCl)2; G6- 0.5% Ca(OCl)2 + EDTA; G7- 2.5% Ca(OCl)2; G8- 2.5% Ca(OCl)2 + EDTA; G9- 6% Ca(OCl)2; G10- 6% Ca(OCl)2 + EDTA. The samples were fragmented and stained with Picrosirius. Data were analyzed by Kruskal-Wallis and Dunn (P<0.05). There was a strong correlation between the results of the canal lumen and the border of the root canal (r=0.962). Both hypochlorites at a concentration of 0.5% showed less microbial reduction compared to 2.5% and 6% (P<0.05). There was less antimicrobial activity at 15 seconds compared to 30 and 60 seconds (P<0.05). Ca(OCl)2 and NaOCl showed similar results at the same concentrations (P>0.05). In conclusion, Ca(OCl)2 caused fewer alterations to the dentin organic matrix at concentrations of 0.5% and 2.5%. Ca(OCl)2 presents antimicrobial activity similar to NaOCl, and collagen damage is concentration-dependent.

Resumo Este estudo teve como objetivo avaliar a atividade antimicrobiana do hipoclorito de cálcio (Ca(OCl)2) e do hipoclorito de sódio (NaOCl) usando a microscopia confocal a laser (MCVL) e a alteração da matriz orgânica da dentina por meio da coloração com picrosirius e microscopia óptica (MO). Amostras de dentes humanos extraídos foram infectados com Enterococcus faecalis por centrifugação da suspensão bacteriana. As amostras foram tratadas com Ca(OCl)2 ou NaOCl a 0,5%, 2,5% e 6% durante 15, 30 e 60 segundos. A MCVLe a coloração de viabilidade foram utilizadas para analisar quantitativamente as proporções de bactérias vivas/mortas no lúmen do canal e no bordo do canal radicular. Os dados foram analisados por ANOVA e teste de Fisher LSD. Para análise de MO, cem dentes bovinos foram divididos aleatoriamente em 10 grupos teste (n=10): G1- Sem tratamento; G2- 17% de EDTA; G3- 6% de NaOCl; G4- 6% de NaOCl + EDTA; G5- 0,5% de Ca(OCl)2; G6- 0,5% de Ca(OCl)2 + EDTA; G7- 2,5% de Ca(OCl)2; G8- 2,5% de Ca(OCl)2 + EDTA; G9- 6% de Ca(OCl)2; G10- 6% de Ca(OCl)2 + EDTA. As amostras foram fragmentadas e coradas com Picrosirius. Os dados foram analisados por Kruskal-Wallis e teste de Dunn (P<0,05). Houve uma forte correlação nos resultados do lúmen do canal e na borda do canal radicular (r=0,962). Ambos os hipocloritos, a uma concentração de 0,5%, mostraram menor redução microbiana em comparação com 2,5% e 6% (P<0,05). Houve menor atividade antimicrobiana aos 15 segundos em comparação com 30 e 60 segundos (P<0,05). Em conclusão, o Ca(OCl)2 e o NaOCl apresentaram resultados semelhantes nas mesmas concentrações (P>0,05). O Ca(OCl)2 causou menos alterações na matriz orgânica da dentina em concentrações de 0,5% e 2,5%. O Ca(OCl)2 apresenta atividade antimicrobiana semelhante ao NaOCl, e os danos ao colágeno dependem da concentraçã

Calcium oxalate crystal macropattern and its usefulness in the taxonomy of Baccharis (Asteraceae).

This study provides a comprehensive account of the various types of calcium oxalate crystals found in the genus Baccharis and assesses the exceptional value of crystal macropatterns for the taxonomy of the genus. The morphotype, occurrence, and chemical composition of the crystals found in the stems and leaves are studied. The 44 species included in this study were selected based on a broad phylogeny-based sampling covering seven subgenera and 31 sections. These species were chosen to represent all the main phylogenetic lineages of Baccharis; thus, the sampling also represents a comprehensive coverage concerning evolutionary significance for such a large and environmentally and economically important plant group. The samples were analyzed by light microscopy, scanning electron microscopy (SEM), and energy-dispersive x-ray spectroscopy (EDS). Several morphotypes of crystals, including druses, crystal sand, styloids and prisms, were present. Based on their chemical composition, the crystals were classified as pure calcium oxalate, mixtures of oxalates and sulfates, and mixtures of oxalates, sulfates, and silica. The crystal macropatterns observed in this study aid in species identification and provide novel data for the taxonomy of Baccharis. RESEARCH HIGHLIGHTS: Most species of Baccharis have a specific crystalline pattern. Each species produces a crystal morphotype or a set of morphotypes specific to it. The crystals observed are formed by calcium oxalate.

Instant polarized light microscopy pi (IPOLπ) for quantitative imaging of collagen architecture and dynamics in ocular tissues.

Collagen architecture determines the biomechanical environment in the eye, and thus characterizing collagen fiber organization and biomechanics is essential to fully understand eye physiology and pathology. We recently introduced instant polarized light microscopy (IPOL) that encodes optically information about fiber orientation and retardance through a color snapshot. Although IPOL allows imaging collagen at the full acquisition speed of the camera, with excellent spatial and angular resolutions, a limitation is that the orientation-encoding color is cyclic every 90 degrees (π/2 radians). In consequence, two orthogonal fibers have the same color and therefore the same orientation when quantified by color-angle mapping. In this study, we demonstrate IPOLπ, a new variation of IPOL, in which the orientation-encoding color is cyclic every 180 degrees (π radians). Herein we present the fundamentals of IPOLπ, including a framework based on a Mueller-matrix formalism to characterize how fiber orientation and retardance determine the color. The improved quantitative capability of IPOLπ enables further study of essential biomechanical properties of collagen in ocular tissues, such as fiber anisotropy and crimp. We present a series of experimental calibrations and quantitative procedures to visualize and quantify ocular collagen orientation and microstructure in the optic nerve head, a region in the back of the eye. There are four important strengths of IPOLπ compared to IPOL. First, IPOLπ can distinguish the orientations of orthogonal collagen fibers via colors, whereas IPOL cannot. Second, IPOLπ requires a lower exposure time than IPOL, thus allowing faster imaging speed. Third, IPOLπ allows visualizing non-birefringent tissues and backgrounds from tissue absorption, whereas both appear dark in IPOL images. Fourth, IPOLπ is cheaper and less sensitive to imperfectly collimated light than IPOL. Altogether, the high spatial, angular, and temporal resolutions of IPOLπ enable a deeper insight into ocular biomechanics and eye physiology and pathology.

Sequential SEM-EDS, PLM, and MRS Microanalysis of Individual Atmospheric Particles: A Useful Tool for Assigning Emission Sources.

In this work, the particulate matter (PM) from three different monitoring stations in the Monterrey Metropolitan Area in Mexico were investigated for their compositional, morphological, and optical properties. The main aim of the research was to decipher the different sources of the particles. The methodology involved the ex situ sequential analysis of individual particles by three analytical techniques: scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), polarized light microscopy (PLM), and micro-Raman spectroscopy (MRS). The microanalysis was performed on samples of total suspended particles. Different morphologies were observed for particles rich in the same element, including prismatic, spherical, spheroidal, and irregular morphologies. The sequential microanalysis by SEM-EDS/PLM/MRS revealed that Fe-rich particles with spherical and irregular morphologies were derived from anthopogenic sources, such as emissions from the metallurgical industry and the wear of automobile parts, respectively. In contrast, Fe-rich particles with prismatic morphologies were associated with natural sources. In relation to carbon (C), the methodology was able to distinguish between the C-rich particles that came from different anthopogenic sources-such as the burning of fossil fuels, biomass, or charcoal-and the metallurgical industry. The optical properties of the Si-rich particles depended, to a greater extent, on their chemical composition than on their morphology, which made it possible to quickly and accurately differentiate aluminosilicates from quartz. The methodology demonstrated in this study was useful for performing the speciation of the particles rich in different elements. This differentiation helped to assign their possible emission sources.

Cristalurias medicamentosas en el laboratorio de urgencias: reporte de dos casos / Drug induced crystalluria in the emergency laboratory: report of two cases

Ciertos fármacos que son excretados en orina, como los antibióticos, pueden formar cristales cuando la dosis empleadas son elevadas, la diuresis se encuentra disminuida o el pH de la orina es ácido. Los eventos de cristaluria medicamentosa son poco frecuentes y pueden ser cuadros asintomáticos e incluso originar fallos renales agudos. En este reporte se describen dos casos: una mujer de 26 años con cristaluria de ampicilina y una niña de 8 años con cristaluria de amoxicilina, registrados en el laboratorio de urgencias del Hospital Central del Instituto de Previsión Social. El análisis del sedimento fue realizado empleando microscopía óptica, luego los cristales fueron sometidos a microscopía de polarización y espectrofotometría infrarroja logrando la identificación exacta de la naturaleza química de los cristales. Este es el primer reporte de cristaluria medicamentosa del país y pone de manifiesto la importancia del trabajo colaborativo entre instituciones del estado.

Certain drugs that are excreted in the urine, including antibiotics, could induce theformation of crystals when the dose used is high, the diuresis is low or the pH of the urine isacid. The events of drug induced crystalluria are rare and could be asymptomatic or couldcause acute renal failure. In this report, we describe two cases: One of a 26-year-oldwoman with ampiciline crystalluria and a 8-year-old child with amoxiciline crystalluria, bothregistered at the Emergency Laboratory of the Central Hospital of the Instituto de PrevisionSocial. The analysis of the urinary sediment was made by conventional microscopy, andthen the crystals were studied by polarized light microscopy and infrared spectroscopyachieving the exact identification of the chemical nature of the crystals. This is the firstreport of drug induced crystalluria in the country and shows the importance of thecolaborative work between state institutions.

Correlação entre a avaliação microscópica e a leitura por laser fluorescência de lesões de manchas brancas em dentes bovinos: estudo in vitro / Correlation between the microscopic evaluation and reading by laser fluorescence of enamel decalcification in bovine teeth: in vitro study

Objetivo: avaliar a correlação entre as leituras de descalcificação artificial de esmalte in vitro por meio do DIAGNOdent® e pela microscopia óptica com luz polarizada. Metodologia: foram utilizados 25 dentes bovinos que foram expostos a um meio artificial de cáries por uma hora, duas vezes ao dia, por 35 dias. Em seguida, procedeu-se as leituras das fluorescências utilizando o aparelho laser DIAGNOdent®. Foram registradas as leituras das áreas sem descalcificação (para calibração) e as áreas desmineralizadas artificialmente. Após as leituras da fluorescência, as regiões de leitura por laser foram cortadas em secções de aproximadamente 400μm e avaliadas por meio da microscopia de luz polarizada. Resultados: demonstraram que, embora com algum grau de variação, o sistema DIAGNOdent® foi capaz de detectar as descalcificações semelhantemente àqueles reconhecidos por microscopia de luz polarizada, estabelecendo um padrão razoável de equivalência de leituras. Conclusão: os valores médios encontrados para o DIAGNOdent® demonstraram um coeficiente de correlação de Pearson de 0,63 com relação aos valores das leituras microscópicas.

Aim: evaluate the correlation between the artificial in vitro enamel decalcification through DIAGNOdent® laser and through optic microscopic with polarized light. Methodology: for this research, 25 bovine teeth had been exposed to an artificial decay environment during one hour, two times a day, for 35 days. After wards, DIAGNOdent® laser has been used to read the fluorescence from the enemel areas without decalcification (for calibration) and to evaluate the non-mineralized artificially. After the fluorescence readings regions of laser read were cut into sections of about 400μm and evaluated by polarized light microscopy. Results: the results had demonstrated that, even with some degree of variation, the DIAGNOdent® system was capable of recognizing the decalcification, establishing regular equivalence of standard readings such as light polarized microscopy. Conclusion: the average values found for DIAGNOdent® laser had demonstrated a 0,63 coefficient of correlation of Pearson to the values of microscopically readings.

Macromolecular array patterns of silk gland secretion in social Hymenoptera larvae

The cocoon, produced by most holometabolous insects, is built with silk that is usually produced by the larval salivary gland. Although this silk has been widely studied in the Lepidoptera, its composition and macromolecular arrangement remains unknown in the Hymenoptera. The macromolecular array patterns of the silk in the larval salivary gland of some meliponids, wasps, and ants were analyzed with polarized-light microscopy, and they were compared with those of Bombyx mori (Lepidoptera). There is a birefringent secretion in the glandular lumen of all larvae, due to filamentous structural proteins that display anisotropy. The silk in the distal, middle and proximal regions of the secretory portion of Formicidae and Vespidae glands presented a lattice optical pattern. We found a different pattern in the middle secretory portion of the Meliponini, with a zigzag rather than a lattice pattern. This indicates that the biopolymer fibers begin their macromolecular reorganization at this glandular region, different from the Formicidae and the Vespidae, in which the zigzag optical pattern was only found at the lateral duct. Probably, the mechanism of silk production in the Hymenoptera is a characteristic inherited from a common ancestor of Vespoidea and Sphecoidea; the alterations in the pattern observed in the Meliponini could be a derived characteristic in the Hymenoptera. We found no similarity in the macromolecular reorganization patterns of the silk between the Hymenoptera species and the silkworm.