Retinal microstructure and developmental characteristics in Zebrafish / 解剖学报

Objective To study the microscopic structure and morphological characteristics of Zebrafish eyeball and retina at different developmental stages, and to lay a foundation for visual research model. Methods Select eight groups of zebrafish at different ages, with six fish in each group, 48 fish in total. Optical microscopy and transmission electron microscopy were used to observe the eyeball structure of Zebrafish at different developmental stages, and the thickness of retinal each layer was measured to analyze the temporal and spatial development pattern. The morphological characteristics of various cells in the retina and the way of nerve connection were observed from the microscopic and ultrastructural aspects, especially the structural differences between rod cells and cone cells. Results The retina of Zebrafish can be divided into ten layers including retinal pigment epithelial layer, rod cells and cone cells layer, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, nerve fiber layer, inner limiting membrane. Rod cells had a smaller nucleus and a higher electron density than cone cells. Photoreceptor terminals were neatly arranged in the outer plexiform layer, forming neural connections with horizontal cells and bipolar cells, and several synaptic ribbons are clearly visible within them. In Zebrafish retina, ganglion cell layer and inner plexiform layer are the earliest developed. With the growth and development of Zebrafish, the thickness of rod cells and cone cells layer and retinal pigment epithelial layer gradually increases, and the retinal structure was basically developed in about 10 weeks. Conclusion The retinal structure of Zebrafish is typical, with obvious stratification and highly differentiated nerve cells. There are abundant neural connections in the outer plexiform layer. The ocular development characteristics of Zebrafish are similar to those of most mammals.

Comprehensive analysis of insulin products complex disulfide bonds structure by high resolution mass spectrum / 药学学报

The correct pairing of disulfide bonds maintains the correct folding mode and high-level structure formation of peptides and protein drugs, which is crucial for the quality control of products. In order to ensure that the disulfide bonds are correctly paired, disulfide bond analysis is an essential part of peptides and protein drug characterization. Mass spectrometry can be used to analyze disulfide bonds. However, insulin and its analogues have two pairs of disulfide bonds without restriction enzyme cutting site. Conventional collision-induced dissociation (CID) and high-energy induced cleavage (HCD) cannot accurately locate the complex disulfide bond. In our study, three methods were used to localize the complex disulfide, including enzyme digestion combined with key peptide fragment in source decay (ISD) fragmentation method, enzyme digestion combined with partial reduction alkylation method, intact protein source ISD and electron transfer dissociation (ETD) cleavage method, The applicability of insulin aspart, insulin lispro and insulin glargine were also investigated. This study provides a new way for the quality control of disulfide bonding mode of insulin and its analogues, and also provides a reference for the disulfide bond localization of peptides or proteins containing this complex disulfide bond.

Exploring Scientific Connotation of "Fried Charcoal Survivability" of Lonicerae Japonicae Flos Based on Color-composition Correlation / 中国实验方剂学杂志

ObjectiveTo explore the scientific connotation of fried charcoal survivability of Lonicerae Japonicae Flos（LJF） by analyzing the correlation between the color change and the intrinsic components during the processing of LJF Carbonisata（LJFC）， and taking pH， charcoal adsorption and microscopic characteristics as indexes. MethodLJFC samples with different degrees of processing were prepared according to the stir-frying time of 0.0， 1.5， 3.0， 4.5， 6.0， 7.5， 9.0， 10.5 min（numbered S1-S8）， and the contents of gallic acid， chlorogenic acid， cryptochlorogenic acid， rutin， luteoloside， isochlorogenic acid A and isochlorogenic acid C were determined by high performance liquid chromatography（HPLC）， and the L*（brightness）， a*（red-greenness） and b*（yellow-blueness） of LJFC samples with different degrees of processing were determined by spectrophotometer， and the correlation analysis and principal component analysis（PCA） between the contents of seven representative components and the color of the samples were carried out by SPSS 26. 0 and SIMCA-P 14.1. Then pH， adsorption force and characteristic structure of different samples of LJFC were detected and the processing pattern of LJFC was analyzed. ResultThe results of quantitative analysis revealed that the contents of luteoloside， rutin， chlorogenic acid and isochlorogenic acid A gradually decreased， and the contents of cryptochlorogenic acid， isochlorogenic acid C and gallic acid firstly increased and then decreased. The L* and b* of the sample powders decreased， and a* showed a trend of increasing and then decreasing. The L* and b* were positively correlated with the contents of chlorogenic acid， rutin， luteoloside， isochlorogenic acid A， b* was positively correlated with the content of gallic acid， and a* was positively correlated with the contents of cryptochlorogenic acid and isochlorogenic acid C. PCA revealed that samples could be clearly divided into 3 groups， S1-S2 as one group， S3-S5 as one group， and S6-S8 as one group， with S3 having the highest score. The results of regression analysis showed that only isochlorogenic acid C could be used to predict the contents of components by colorimetric values combined with regression equations. Physicochemical analysis showed that pH of LJFC increased with the increase of degree of charcoal stir-frying， while adsorption force showed a tendency of increasing and then decreasing， with the highest adsorption force in the S5 sample， and the non-glandular hairs， calcium oxalate clusters and pollen grains had a varying degree of decreasing with the deepening of processing degree， and the microstructures of S6-S8 samples were obviously charred with pollen grains almost invisible. ConclusionThe changes in chemical composition and color characteristics of LJFC during the processing have certain correlations， combined with the changes in physicochemical properties， S5 sample is found to be the optimal processed products， which can provide a reference for the processing standardization and quality evaluation of LJFC， and enrich the scientific connotation of fried charcoal survivability of LJF.

Synthesis, characterization and protection effect of black rice anthocyanins nano-composite against hepatotoxicity induced by methotrexate in rats

Abstract The present study aimed to investigate the beneficial of prepared black rice anthocyanins nano-composite (An-AgNps) against hepatotoxicity induced by methotrexate (MTX) in rats. Anthocyanins nano-composite was prepared by silver as the metallic ion reduction and were characterized by IR and SEM. The rats in our experiment were divided into five groups. Serum lipid profile, serum transaminases (ALT and AST), ALP, LDH, TBA, GSH and SOD were examined. The results show that SEM of An-AgNps has average particle size from 70 to 130nm. In the group treated with MTX; TC, TG, LDL-c, ALT, AST, ALP, LDH and TBA levels were significantly (P0.05) increased than NC, while, HDL-c, SOD and GSH levels were significantly (P0.05) decreased. On the other hand, An-AgNps + MTX treated groups were reversed the levels of all biomarkers similar to NC. In conclusion, the results show that An-AgNps has a protective effect on MTX-induced hepatotoxicity and oxidative stress.

Resumo O presente estudo teve como objetivo investigar o benefício de nanocompósito de antocianinas de arroz preto preparado (An-AgNps) contra a hepatotoxicidade induzida por metotrexato (MTX) em ratos. O nanocompósito de antocianinas foi preparado a partir da prata por meio da redução do íon metálico e caracterizado por IR e SEM. Os ratos em nosso experimento foram divididos em cinco grupos, e foram examinados o perfil lipídico sérico, as transaminases séricas (ALT e AST), ALP, LDH, TBA, GSH e SOD. Os resultados mostram que SEM de An-AgNps tem tamanho médio de partícula de 70 a 130 nm. No grupo tratado com MTX, os níveis de TC, TG, LDL-c, ALT, AST, ALP, LDH e TBA aumentaram significativamente (P 0,05) do que NC, enquanto os níveis de HDL-c, SOD e GSH diminuíram significativamente (P 0,05). Por outro lado, nos grupos tratados com An-AgNps + MTX, foram revertidos os níveis de todos os biomarcadores semelhantes ao NC. Em conclusão, os resultados mostram que o An-AgNps tem um efeito protetor contra a hepatotoxicidade induzida pelo MTX e o estresse oxidativo.

A microscopia eletrônica de varredura pode ser usada para medir quantitativamente a rugosidade da dentina? / Can Scanning Electron Microscopy be used to quantitatively measure dentine roughness?

Objective: The aim of this study was to determine if SEM used with imaging software could be used to quantitatively determine the extent of dentine roughness due to tooth-brushing. Material and methods: Flat, polished dentine surfaces were subjected to 25,000 cycles of simulated tooth-brushing at 2 strokes per second with a load of 200 g. At the end of the brushing cycle, dentine surfaces were first assessed using profilometry and then subjected to SEM analysis. Ra (average roughness) readings were obtained for profilometric assessment. Using imaging software, the horizontal distance between adjacent characteristic grooves noted on micrographs was measured, ensuring that the middle of each crest of the associated groove was used as the reference point, the Crest-to-Crest distance (C-C distance). These two parameters were examined statistically for correlation. Results: When Spearman Rank tests were utilized the correlation between average Ra and crest to crest measurements was 0.709 (p <0.01). The Bland Altman plot, however, showed poor agreement between the two test parameters. Conclusion: Further work is needed to validate the use of this methodology in the quantitative assessment of tooth surface loss due to abrasion (AU)

Objetivo: O objetivo deste estudo foi determinar se o MEV usado com software de imagem poderia ser usado para determinar quantitativamente a extensão da rugosidade da dentina devido à escovação dentária. Material e Métodos: Superfícies dentinárias planas e polidas foram submetidas a 25.000 ciclos de escovação dentária simulada a 2 movimentos por segundo com uma carga de 200g. No final do ciclo de escovação, as superfícies dentinárias foram primeiro avaliadas por perfilometria e depois submetidas à análise MEV. Leituras de Ra (rugosidade média) foram obtidas para avaliação perfilométrica. Utilizando um software de imagem, foi medida a distância horizontal entre sulcos característicos adjacentes observados nas micrografias, garantindo que o meio de cada crista do sulco associado fosse usado como ponto de referência, a distância crista a crista (distância CC). Esses dois parâmetros foram examinados estatisticamente para correlação. Resultados: Quando foram utilizados os testes de Spearman Rank, a correlação entre a média de Ra e as medidas de crista a crista foi de 0,709 (p<0,01). O gráfico de Bland Altman, no entanto, mostrou fraca concordância entre os dois parâmetros de teste. Conclusão: Mais trabalhos são necessários para validar o uso desta metodologia na avaliação quantitativa da perda da superfície dentária devido à abrasão(AU)

Does the combination of whitening toothpaste and hydrogen peroxide bleaching increase the surface roughness and change the morphology of a nanofilled composite?

Aim: To evaluate changes in the surface roughness and morphology of a nanofilled composite following toothbrushing with a whitening (WT) or regular toothpaste (RT), alone or combined with 35% hydrogen peroxide bleaching (HP). Methods: Seventy disc-shaped nanofilled composite (Filtek Z350XT) specimens were randomly divided into groups (n=10): WT, RT, TB (without toothpaste ­ control) or the combinations WT/ HP, RT/HP, TB/HP and HP. All groups underwent toothbrushing simulation (60,000 cycles) and bleaching treatment (4 sessions). Mean surface roughness (Ra, µm) was measured before (T0) and after treatments (TB). Surface morphology was assessed by scanning electron microscopy (SEM) at TB. Mean Ra was analyzed using general mixed models and multiple comparisons by the Tukey-Kramer test (α=5%). Results: HP caused no surface roughness changes on the nanofilled composite after treatment (p>0.05). RT toothbrushing, combined or not with HP, increased the surface roughness (p<0.05). WT and WT/ HP protocols had no effect on the surface roughness of the composite (p>0.05). The nanofilled composite submitted to RT toothbrushing combined with HP (RT/HP) presented substantial surface alterations under SEM, showing deep depressions and round-shaped defects. Toothbrushing with RT combined with the bleaching agent increased exposure of the inorganic fillers. Conclusion: WT toothbrushing, regardless of HP combination, or the single HP protocol had no effect on the surface roughness of the nanofilled composite. However, RT combined with HP negatively affected surface roughness and presented the most noticeable surface changes among groups

Embryo development is impaired by sperm mitochondrial-derived ROS

BACKGROUND: Basal energetic metabolism in sperm, particularly oxidative phosphorylation, is known to condition not only their oocyte fertilising ability, but also the subsequent embryo development. While the molecular pathways underlying these events still need to be elucidated, reactive oxygen species (ROS) could have a relevant role. We, therefore, aimed to describe the mechanisms through which mitochondrial activity can influence the first stages of embryo development. RESULTS: We first show that embryo development is tightly influenced by both intracellular ROS and mitochondrial activity. In addition, we depict that the inhibition of mitochondrial activity dramatically decreases intracellular ROS levels. Finally, we also demonstrate that the inhibition of mitochondrial respiration positively influences sperm DNA integrity, most likely because of the depletion of intracellular ROS formation. CONCLUSION: Collectively, the data presented in this work reveals that impairment of early embryo development may result from the accumulation of sperm DNA damage caused by mitochondrial-derived ROS.

Comparative analysis of SARS-CoV-2 variants Alpha (B.1.1.7), Gamma (P.1), Zeta (P.2) and Delta (B.1.617.2) in Vero-E6 cells: ultrastructural characterization of cytopathology and replication kinetics

Abstract This study compares the effects of virus-cell interactions among SARS-CoV-2 variants of concern (VOCs) isolated in Brazil in 2021, hypothesizing a correlation between cellular alterations and mortality and between viral load and transmissibility. For this purpose, reference isolates of Alpha, Gamma, Zeta, and Delta variants were inoculated into monolayers of Vero-E6 cells. Viral RNA was quantified in cell supernatants by RT‒PCR, and infected cells were analyzed by Transmission Electron Microscopy (TEM) for qualitative and quantitative evaluation of cellular changes 24, 48, and 72 hours postinfection (hpi). Ultrastructural analyses showed that all variants of SARS-CoV-2 altered the structure and function of mitochondria, nucleus, and rough endoplasmic reticulum of cells. Monolayers infected with the Delta variant showed the highest number of modified cells and the greatest statistically significant differences compared to those of other variants. Viral particles were observed in the cytosol and the cell membrane in 100 % of the cells at 48 hpi. Alpha showed the highest mean particle diameter (79 nm), and Gamma and Delta were the smallest (75 nm). Alpha and Gamma had the highest particle frequency per field at 48 hpi, while the same was observed for Zeta and Delta at 72 hpi and 24 hpi, respectively. The cycle threshold of viral RNA varied among the target protein, VOC, and time of infection. The findings presented here demonstrate that all four VOCs evaluated caused ultrastructural changes in Vero-E6 cells, which were more prominent when infection occured with the Delta variant.

Effect of Clomiphene Citrate on the Ultrastructure of Testis in Albino Rats

SUMMARY: The aim of the present work was to study the closer effect of clomiphene citrate on the ultrastructure of the testis of adult albino rats to provide a basis for optimizing this drug in the treatment of male infertility. The testes were removed from both groups under anesthesia and then prepared for examination by light using hematoxylin and eosin stains and a transmission electron microscope. Semithin sections were cut into 1 µm thick sections, stained with toluidine blue, and examined by light microscopy for a survey. The desired areas were placed in the center, and other areas were trimmed. Primary spermatocytes showed marked nuclear changes (pyknosis), and their nuclear membranes were ill-defined and disrupted. The cytoplasm showed widespread degeneration of mitochondria and lysosomes and focal degeneration of the rough endoplasmic reticulum compared with the control group. The spermatids were pale, and the two phases of spermatogenesis were distinctly identifiable in the control group but were confused in the treated group. Some spermatids had interrupted nuclear membranes, also containing degenerated mitochondria, focal fragmentation of rough endoplasmic reticulum, and free ribosomes. Spermatozoa in the treated group appeared deformed compared to the control, where they had deformed head caps. Leydig cells of the treated group have an irregularly shaped nucleus, with focal chromatin aggregation and peripheral chromatin condensation on the inner surface of the nuclear membrane. The observations of the present work indicate a possible causal relationship between testicular affection and ingestion of clomiphene citrate, which can be avoided by close medical observations using ultrasonography, semen analysis, or testicular biopsy to detect early malignant changes. Furthermore, the drug should not be used for more than three to six cycles and should be stopped for at least three cycles before reuse. When clomiphene citrate is ineffective in the treatment of male infertility, human menopausal gonadotropin (hMG) administration is typically selected. However, high-dose hMG therapy is associated with a variety of adverse effects. In this work, we report the success of a modified clomiphene citrate regimen in increasing sperm count without any hazards to the testicular tissue.

El objetivo del trabajo fue estudiar el efecto del citrato de clomifeno sobre la estructura de los testículos de la rata albina adulta, con la finalidad de determinar la mejor manera de utilizar este fármaco en el tratamiento de la infertilidad masculina. Los testículos se extrajeron bajo anestesia y para su análisis a través de microscopio de luz se tiñeron con HE. Además, las muestras fueron preparadas para su examen con microscopía electrónica de transmisión. Por otra parte, se cortaron secciones semifinas de 1 µm de espesor, se tiñeron con azul de toluidina y se examinaron mediante microscopía óptica. Los espermatocitos primarios mostraron cambios nucleares marcados (picnosis) y sus membranas nucleares estaban mal definidas y alteradas. En el grupo experimental las células presentaban el citoplasma con degeneración generalizada de las mitocondrias y de los lisosomas y una degeneración focal del retículo endoplásmico rugoso en comparación con el grupo control. Las espermátidas estaban pálidas y las dos fases de la espermatogénesis eran claramente identificables en el grupo control, pero se confundían en el grupo tratado. Algunas espermátidas tenían membranas nucleares interrumpidas, y también contenían mitocondrias degeneradas, fragmentación focal del retículo endoplásmico rugoso y ribosomas libres. Los espermatozoides del grupo tratado se presentaban deformados en comparación con el control. Las células de Leydig del grupo tratado presentaban un núcleo de forma irregular, con agregación focal de cromatina y condensación de cromatina periférica en la superficie interna de la membrana nuclear. Las observaciones del presente trabajo indican una posible relación causal entre la afección testicular y la ingestión de citrato de clomifeno, que puede evitarse mediante observaciones médicas minuciosas a través de ecografía, análisis de semen o biopsia testicular para detectar cambios malignos tempranos. Además, el medicamento no debiera ser usado durante más de tres a seis ciclos y debe suspenderse durante al menos tres ciclos antes de volver a usarlo. Cuando el citrato de clomifeno es ineficaz en el tratamiento de la infertilidad masculina, normalmente se selecciona la administración de gonadotropina menopáusica humana (hMG). Sin embargo, la terapia con hMG en dosis altas se asocia con una variedad de efectos adversos. En este trabajo, informamos el éxito de un régimen modificado con citrato de clomifeno para aumentar el recuento de espermatozoides sin riesgo para el tejido testicular.

Avaliação dos Efeitos da Remoção da Resina Residual e do Polimento na Superfície do Esmalte após Descolagem do Braquete / Evaluation of the Effects of Residual Resin Removal and Polishing on the Enamel Surface after Bracket Debonding

Considerando o uso de brocas para remoção da resina residual após descolagem do braquete e a possibilidade de injúrias à superfície do esmalte após o uso dessas brocas, este trabalho teve como objetivo realizar um estudo experimental, para avaliar a variação do aspecto superficial do esmalte de forma qualitativa, por meio da avaliação com imagens topográficas do esmalte dentário, utilizando-se a Microscopia Eletrônica de Varredura (MEV), a qual permitiu ilustrar e avaliar a superfície do esmalte após a fase de polimento final, realizada por dois métodos: taça de borracha ou escova Robinson. Foram utilizados 25 dentes pré-molares humanos, obtidos a partir de exodontias em pacientes que procuraram voluntariamente o curso de Residência em Cirurgia da Clínica Odontológica Universitária da Universidade Estadual de Londrina. Os dentes foram divididos em quatro grupos: A, B, C e D, contendo 6 dentes cada, de acordo com as brocas utilizadas para a remoção do remanescente adesivo e o polimento escolhido, além de um dente como "controle". Foi avaliada a rugosidade superficial do esmalte após a remoção da resina e a superfície do esmalte após o polimento com as duas opções apresentadas. Os resultados mostraram que, por observação e inspeção, as brocas removeram a resina residual de todos os dentes, porém, causaram riscos e ranhuras, como evidenciado nas imagens em MEV. Concluiu-se que não houve diferença estatística entre os métodos de polimento e que ambos foram importantes para a redução das marcas abrasivas, proporcionando uma superfície mais lisa do esmalte.

Considering the use of specific burs to remove residual resin after bracket debonding and the possibility of injuries to the dental enamel after using these burs, this study aimed to verify the variation in the enamel surface appearance in a qualitative way and evaluation with topographic images of the dental enamel. The use of Scanning Electron Microscopy (SEM) allowed to illustrate and evaluate the enamel surface after the final polishing phase using two methods: rubber cup or Robinson brush. Twenty-five human premolar teeth were obtained from extractions in patients who voluntarily sought the Oral Maxillofacial Surgery Residency at the Dental School from the State University of Londrina; the teeth were divided into four groups A, B, C and D containing 6 teeth each according to the burs used to remove the remaining adhesive and the chosen polishing, in addition to one tooth as a "control". Dental enamel surface roughness was evaluated after resin removal and enamel surface after polishing with the two methods presented. The results showed that by observation and inspection, the burs removed residual resin from all teeth, however, caused scratches and grooves as evidenced in the SEM images. Based on the results, there was no statistical difference between the polishing methods, and both were important for the reduction of abrasive marks and provided a smoother enamel surface.

Removal and identification of a subconjunctival parasite by light and scanning electron microscopy

Background: Ophthalmic dirofilariasis is an uncommon zoonotic parasitic infection caused by species of Dirofilaria, a dog tapeworm that is transmitted to human by mosquitoes. Man is a dead?end host for the parasite. Ophthalmic involvement is rare and includes periorbital, subconjunctival, subtenon, and intra?ocular involvement. We report the removal of a subconjunctival worm and identification by light microscopy (LM) and scanning electron microscopy (SEM). Purpose: A 62?year?old female presented with complaints of redness, discharge, and foreign body sensation with difficulty in opening eyes in the left eye for the last 3 days. The patient is a non?vegetarian. On examination, her best corrected visual acuity in both eyes was 20/20. On slit lamp examination, there was a long, thin, round, coiled white subconjunctival live worm in the left eye superiorly. The rest of anterior segment evaluation, intra?ocular pressure, and fundus was normal in both eyes. The parasite was removed under local anesthesia from subconjunctival space [Video]. External surface morphology under LM revealed fine transverse cuticular striations with tapered cephalic and caudal ends. Uterus was long and coiled with indistinguishable masses inside. The finding was also confirmed by SEM. Synopsis: A subconjuctival parasite was removed and identified as Dirofilaria repens by characteristic LM and SEM findings. Highlight: Dirofilaria species may lodge in many tissues of human bodies including eye and adnexa. Dirofilaria is a natural parasite of carnivorous animals, mostly dogs, cats, and foxes.[1] The most common mode of transmission to human is usually by bite of mosquitoes like Culex and Aedes, which are considered as vectors, and it is often thought that parasitemia is because of accidental conduction.[1] Simple surgical removal of the worm is curative. After removal, the worm should be visualized directly under LM. All the internal structures of the transparent worm could be seen and compared with those under SEM.

Effects of whitening dentifrices on the enamel color, surface roughness, and morphology

The aim of this study was to evaluate the whitening and abrasion effects of dentifrices containing different whitening agents on artificially stained and unstained enamel. 160 human dental enamel discs were distributed into four groups according to the type of dentifrices applied on them (n=40): Group I, non-whitening dentifrice (control group); Group II, dentifrice containing charcoal; Group III, dentifrice containing blue covarine; Group IV, dentifrice containing hydrogen peroxide. Half of the specimens in each group were immersed in coffee solution. Color measurements were evaluated from stained and unstained specimens before and after brushing by a spectrophotometer. The surface roughness of each unstained specimen was analyzed using a profilometer after the brushing and bleaching. The surface of one randomly selected specimen from each group was observed using a scanning electron microscope (SEM). Statistical analysis of the color change was performed using the Kruskal-Wallis test. The one-way ANOVA was used to evaluate surface roughness. Group III provided significantly higher recovery on ΔE00 values than other groups on the unstained enamel (p<0.05). Group IV showed significantly the highest ΔE00 values on stained enamel (p<0.05) and also Group IV showed the highest surface roughness values (p<0.05), SEM revealed a more irregular surface in groups III and IV. It can be stated that dentifrice containing blue covarine is both an effective and a safe way to provide whiter teeth with routine home tooth brushing.

El objetivo de este estudio fue evaluar los efectos de blanqueamiento y abrasión de los dentífricos que contienen diferentes agentes blanqueadores en el esmalte teñido y no teñido artificialmente. Se distribuyeron 160 discos de esmalte dental humano en cuatro grupos según el tipo de dentífrico aplicado sobre ellos (n=40): Grupo I, dentífrico no blanqueador (grupo control); Grupo II, dentífrico que contiene carbón vegetal; Grupo III, dentífrico que contiene azul; Grupo IV, dentífrico que contiene peróxido de hidrógeno. La mitad de los especímenes de cada grupo se sumergieron en una solución de café. Las mediciones de color se evaluaron a partir de especímenes teñidos y no teñidos antes y después del cepillado con un espectrofotómetro. La rugosidad de la superficie de cada muestra sin teñir se analizó utilizando un perfilómetro después del cepillado y del clareamiento. La superficie de un espécimen seleccionado al azar de cada grupo se observó utilizando un microscopio electrónico de barrido (MEB). El análisis estadístico del cambio de color se realizó utilizando la prueba de Kruskal-Wallis. Se utilizó el ANOVA para evaluar la rugosidad de la superficie. El grupo III proporcionó una recuperación significativamente mayor en los valores de ΔE00 que otros grupos en el esmalte no teñido (p<0,05). El Grupo IV mostró significativamente los valores más altos de ΔE00 en el esmalte teñido (p<0.05) y también el Grupo IV mostró los valores más altos de rugosidad superficial (p<0.05), el análisis en MEB reveló una superficie más irregular en los grupos III y IV. Se puede afirmar que el dentífrico que contiene azul es una forma efectiva y segura de proporcionar dientes más claros con el cepillado de rutina en el hogar.

Light Microscopic, Ultrastructure Analysis and Functional Morphology of Cornu aspersum Spermatozoa Contained in the Frozen Hermaphroditic Duct / Análisis de Microscopía de Luz, Ultraestructura y Morfología Funcional de Espermatozoides de Cornu aspersum Contenidos en el Conducto Hermafrodita Congelado

SUMMARY: In this study we describe the functional morphology of Cornu aspersum (Helix aspersa), spermatozoa using light, scanning (SEM) and transmission electron (TEM) microscopies. The studies were performed with sperm located in the frozen hermaphroditic duct. Our results showed that the head presents an elongated conical shape slightly coiled in a corkscrew, with the nucleus partially covered by an acrosome, where an apical vesicle is located at the lateralized apex. This peculiar shape suggests the helical displacement movement of the spermatozoa. The head and the nucleus are slightly larger size compared to those of other gastropod species. The intermediate tract is surrounded by a mitochondrial complex and a glycogen helix. The glycogen helix is coiled helically along the intermediate tract, presenting at least five twists of glycogen helices. The complexity of both the mitochondrial complex and the glycogen helix suggests a high metabolic consumption considering the long period of time until fertilization occurs. Our findings on the detailed characterization of Cornu aspersum spermatozoa, obtained from a frozen hermaphroditic duct can contribute to a better understanding of the functional morphology of sperm and serve as a reference for future studies.

En este estudio describimos la morfología funcional de Cornu aspersum (Helix aspersa), espermatozoides utilizando microscopías de luz, barrido (SEM) y electrónica de transmisión (TEM). Los estudios se realizaron con espermatozoides localizados en el conducto hermafrodita congelado. Nuestros resultados mostraron que la cabeza presenta una forma cónica alargada ligeramente enrollada en un tirabuzón, con el núcleo parcialmente cubierto por un acrosoma, donde se ubica una vesícula apical en el ápice lateralizado. Esta peculiar forma sugiere el movimiento de desplazamiento helicoidal de los espermatozoides. La cabeza y el núcleo son de un tamaño ligeramente mayor en comparación con los de otras especies de gasterópodos. El tracto intermedio está rodeado por un complejo mitocondrial y una hélice de glucógeno. La hélice de glucógeno se enrolla helicoidalmente a lo largo del tracto intermedio, presentando al menos cinco giros de hélices de glucógeno. La complejidad tanto del complejo mitocondrial como de la hélice de glucógeno sugiere un alto consumo metabólico considerando el largo período de tiempo hasta que ocurre la fecundación. Nuestros hallazgos sobre la caracterización detallada de los espermatozoides de Cornu aspersum, obtenidos de un conducto hermafrodita congelado, pueden contribuir a una mejor comprensión de la morfología funcional de los espermatozoides y servir como referencia para futuros estudios.

Role of Aluminium in Alzheimer’s disease: Ultrastructural Study in Rat Hippocampus

Background: Exposure to high levels of aluminium (Al) leads to neurotoxicity. Hippocampus is one of the preferred sites of aluminium accumulation. Nevertheless, the role of Al in Alzheimer’s disease (AD) remains controversial and there is little proof directly interlinking Al to AD. Aims: The present study was undertaken to find out the occurrence of AD pathogenesis in Hippocampus under moderate aluminium exposure in rats. Materials and Methods: Adult rats were divided into control (C) and aluminium treated (E) groups having eight animal each. The rats in group E were exposed to aluminium 4.2 mg/kg body weight for three months with due approval from Institute Animal Ethics Committee. The hippocampus was processed for histopathological and electron microscopy observation. Results: Moderate Al intake produces significant reduction in the count of Pyramidal cells in hippocampus identified by shrunken cells as well as pyknosis in cell bodies. The differences between the cell numbers in all groups were found to be statistically significant (P < 0.05). Cornu Ammonis (CA) exhibited significantly reduced nissl bodies with a marked reduction in neuronal cell loss. Neurofibrillary tangle and plaques were not seen in the given dose of Al exposure. Electron microscopy from experimental group showed that the majority of neurons were disintegrating, the nuclear membrane has ruptured, and nucleoli appeared significantly distorted. The chromatin condensed and the mitochondria had disintegrated. Many vacuoles and lipofuscin sediment in cytoplasm, as compared to the control group noted. Conclusion: Present data demonstrated that moderate chronic aluminium exposure 4.2mg/kg body weight induced neurodegeneration in hippocampus but not significant for Alzheimer’s disease pathogenesis.

Ayudas diagnósticas y diagnóstico diferencial de la enfermedad de Pompe / Diagnostic aids and differential diagnosis of Pompe disease

Introducción: La enfermedad de Pompe (EP) o glucogenosis tipo II es una enfermedad autosómica recesiva causada por mutaciones en el gen GAA que codifica para la proteína alfa-1,4-glucosidasa. Su deficiencia lleva a un almacenamiento anormal de glucógeno en los lisosomas de varias células, a través de los diferentes tejidos, lo que causa un compromiso musculoesquelético predominante. Contenidos: Los fenotipos de la enfermedad dependen de las variantes genéticas y de los niveles de la actividad enzimática residual. La enfermedad se presenta como EP de inicio infantil, EP de inicio tardío y EP intermedio, por lo que es de suma importancia su diagnóstico temprano, por medio de estudios moleculares como la secuenciación de Sanger y la secuenciación de nueva generación. Conclusiones: Se ha demostrado, mediante diferentes estudios, que las variaciones genéticas pueden diferir entre etnias, y es importante su caracterización molecular para determinar el tratamiento más adecuado, de acuerdo con el estado del material inmunológico de reacción cruzada (CRIM).

Introduction: Pompe disease (PD) or Glycogenosis Type II is a rare autosomal recessive disease caused by mutations in the GAA gene that codes for the alpha-1,4-glucosidase protein. Its deficiency leads to abnormal glycogen storage in the lysosomes of various cells throughout the different tissues causing a predominant musculoskeletal compromise. Contents: The phenotypes of the disease depend on the genetic variants and the levels of residual enzyme activity, presenting as infantile-onset PD, late-onset PD, and intermediate PD; Therefore, early diagnosis of the disease through molecular studies such as Sanger sequencing and new generation sequencing is of utmost importance. Conclusions: It has been shown through different studies that genetic variations can vary between ethnic groups and the molecular characterization of the variants is important to determine the most appropriate treatment depending on the state of the cross-reactive immunological material (CRIM)

Depth of cure, mechanical properties and morphology of dual-cure bulk-Fill composites / Profundidad de curado, propiedades mecánicas y morfología de resinas compuestas duales

This study evaluated selected structural and physical properties, such as degree of conversion (DC), Vickers hardness (VHN), and compression strength (CS), of three new dual-cure bulk-fill resin-based composites (RBCs; ACTIVA, HyperFIL, and Fill-Up) and compared them to those of a conventional RBC (Filtek Z250) at three clinically relevant depths. Samples (n=180) were prepared in three depths (2,4, and 6mm). Fourier-transform infrared spectroscopy (FTIR) analysis and VHN and CS tests were performed. The DC value was calculated by considering the relative change in the aliphatic C=C peaks. The fractured surfaces of representative samples were characterized using scanning electron microscopy (SEM). Data were statistically evaluated using two-way analysis of variance and post hoc Bonferroni tests (p<0.05). According to the VHN results, Filtek Z250 showed the highest bottom/top hardness ratio (97.94±1.01) at 2mm thickness and ACTIVA showed the lowest bottom/top hardness ratio (43.48±5.64) at 6mm thickness (p<0.001). According to the FTIR results, the DC decreased with increasing thickness in all materials (p<0.05). Filtek Z250 showed the highest (301±12.4 MPa) and ACTIVA exhibited the lowest (232±17.2 MPa) CS values at 2mm thickness (p<0.05). The lowest CS values were obtained for ACTIVA, and the highest values were obtained for Filtek Z250 for samples with thicknesses of 4 and 6mm, respectively (p<0.05). The structural features of restorative composites, such as the resin chemistry and filler type and content, and the operational parameters (i.e., material thickness and curing conditions) strongly affect crosslinking reactions and thus the DC, VHN, and CS values.

Este estudio evaluó propiedades físicas y estructurales, como el grado de conversión (DC), la dureza Vickers (VHN) y la resistencia a la compresión (CS), de tres nuevos compósitos a base de resina de curado dual tipo bulk (RBC; ACTIVA , HyperFIL y Fill-Up) y los comparó con los de una resina compuesta convencional (Filtek Z250) en tres profundidades clínicamente relevantes. Se prepararon muestras (n=180) en tres profundidades (2,4 y 6mm). Se realizaron análisis de espectroscopia infrarroja por transformada de Fourier (FTIR) y pruebas VHN y CS. El valor de DC se calculó considerando el cambio relativo en los picos alifáticos C=C. Las superficies fracturadas de muestras representativas se caracterizaron mediante microscopía electrónica de barrido (MEB). Los datos se evaluaron estadísticamente mediante análisis de varianza de dos vías y pruebas post hoc de Bonferroni (p<0,05). De acuerdo con los resultados de VHN, Filtek Z250 mostró la relación de dureza inferior/superior más alta (97,94±1,01) con un espesor de 2mm y ACTIVA mostró la relación de dureza inferior/superior más baja (43,48±5,64) con un espesor de 6mm (p<0,001). De acuerdo con los resultados de FTIR, la DC disminuyó al aumentar el espesor en todos los materiales (p<0,05). Filtek Z250 mostró los valores de CS más altos (301±12,4 MPa) y ACTIVA los más bajos (232±17,2 MPa) a 2mm de espesor (p<0,05). Los valores más bajos de CS se obtuvieron para ACTIVA y los valores más altos para Filtek Z250 para muestras con espesores de 4 y 6mm, respectivamente (p<0,05). Las características estructurales de las resinas compuestas de restauración, como la química; además del tipo y contenido del relleno, y los parámetros operativos (es decir, el espesor del material y las condiciones de curado) afectan en gran medida las reacciones de interacción química y, por lo tanto, los valores de DC, VHN y CS.

Evaluation of Structural and Compositional Changes on the Root Surface Exposed to Diode Laser (810 nm): An In?vitro Study

Background: The laser therapy has been used as an adjuvant for conventional periodontal disease as they exhibit a bactericidal effect on scaling and root planning by its thermal and photo disruptive effects on the pathogens. This study focuses on the structural and compositional changes induced on the root surfaces of teeth following diode laser (DL) application with increasing quantum of exposure time. Objective: The objective of this study was to evaluate the structural and compositional changes on the root surface of extracted human permanent teeth after application of DLs (810 nm) with varying time interval. Materials and Methods: Twenty samples of single?rooted periodontally compromised extracted teeth were utilized for this study. Root planning was done and the roughness caused by the instrumentation was measured using profilometric analysis. Then, the samples were divided into four groups, with DL application time: Group 1 – laser application for 15 s, Group 2 – laser application for 30 s, Group 3 – laser application for 45 s, and Group 4 – laser application for 60 s. A scanning electron microscope was used to examine the cemental surface and energy?dispersive X?ray analysis software assesses the compositional changes of the teeth in each group. Results: This study reveals that on exposure of DL (810 nm) on the root surface when time of exposure increases, there were relative increases in surface irregularities and charring. There were significant changes in the chemical composition of the tooth surface.

Impact of radiotherapy on the morphological and compositional structure of intra-radicular dentin

Abstract Considering the side effects in the oral cavity and dental structures of radiotherapy (RDT) for head and neck cancer, this study aimed to evaluate the effects of RDT on the root dentin concerning the obliteration of dentinal tubules, the inorganic composition of intra-radicular dentin, and the integrity of collagen fibers. Thirty human canines were selected from a biobank and randomly divided into two groups (n=15). The samples were sectioned buccolingually, and a hemisection was used for structural analysis by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Low-vacuum SEM images were obtained at 2000-x magnification to observe the obliteration of the dentinal tubules. Moreover, compositional evaluation was performed using EDS. After RDT, the SEM and EDS analyses were repeated using the same methodology. RDT was applied fractionally at 2 Gy per day, 5 days per week, for 7 weeks, resulting in a total dose of 70 Gy. The collagen integrity of the irradiated and non-irradiated samples was analyzed using Masson's trichrome and picrosirius red staining polarization microscopy. Samples subjected to RDT exhibited dentinal tubule obliteration (p < 0.001); low integrity of type I and III collagen fibers (p < 0.05); compositional reduction of calcium (p = 0.012), phosphorus (p = 0.001), and magnesium (p < 0.001); an increased Ca/P ratio (p < 0.001). RDT affects the structure of dentinal tubules, the inorganic composition of intra-radicular dentin, and the collagen fiber integrity in the root dentin, which may interfere with the effectiveness and durability of dental procedures.

Resumo Considerando os efeitos colaterais na cavidade oral e estruturas dentárias da radioterapia (RDT) para o câncer de cabeça e pescoço, este estudo teve como objetivo avaliar os efeitos da RDT sobre a dentina radicular quanto à obliteração dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas. Trinta caninos humanos foram selecionados de um biobanco e divididos aleatoriamente em dois grupos (n=15). As amostras foram seccionadas no sentido vestíbulo-lingual, e uma hemissecção foi utilizada para análise estrutural por microscopia eletrônica de varredura (MEV) e espectrômetro de raios X de dispersão de energia (EDS). Imagens de MEV de baixo vácuo foram obtidas com aumento de 2500x para observar a obliteração dos túbulos dentinários. Além disso, a avaliação composicional foi realizada usando EDS. Após a RDT, as análises em MEV e EDS foram repetidas usando a mesma metodologia. A RDT foi aplicada fracionada a 2 Gy por dia, 5 dias por semana, durante 7 semanas, resultando em uma dose total de 70 Gy. A integridade do colágeno das amostras irradiadas e não irradiadas foi analisada usando microscopia de polarização de coloração com tricrômio de Masson e picrosirius red. As amostras submetidas a RDT apresentaram obliteração dos túbulos dentinários (p < 0,001); baixa integridade das fibras colágenas tipo I e III (p < 0,05); redução composicional de cálcio (p = 0,012), fósforo (p = 0,001) e magnésio (p < 0,001); e uma relação Ca/P aumentada (p < 0,001). A RDT afeta a estrutura dos túbulos dentinários, a composição inorgânica da dentina intra-radicular e a integridade das fibras colágenas na dentina radicular, o que pode interferir na eficácia e durabilidade dos procedimentos odontológicos.

A region-level contrastive learning-based deep model for glomerular ultrastructure segmentation on electron microscope images / 南方医科大学学报

OBJECTIVE@#We propose a novel region- level self-supervised contrastive learning method USRegCon (ultrastructural region contrast) based on the semantic similarity of ultrastructures to improve the performance of the model for glomerular ultrastructure segmentation on electron microscope images.@*METHODS@#USRegCon used a large amount of unlabeled data for pre- training of the model in 3 steps: (1) The model encoded and decoded the ultrastructural information in the image and adaptively divided the image into multiple regions based on the semantic similarity of the ultrastructures; (2) Based on the divided regions, the first-order grayscale region representations and deep semantic region representations of each region were extracted by region pooling operation; (3) For the first-order grayscale region representations, a grayscale loss function was proposed to minimize the grayscale difference within regions and maximize the difference between regions. For deep semantic region representations, a semantic loss function was introduced to maximize the similarity of positive region pairs and the difference of negative region pairs in the representation space. These two loss functions were jointly used for pre-training of the model.@*RESULTS@#In the segmentation task for 3 ultrastructures of the glomerular filtration barrier based on the private dataset GlomEM, USRegCon achieved promising segmentation results for basement membrane, endothelial cells, and podocytes, with Dice coefficients of (85.69 ± 0.13)%, (74.59 ± 0.13)%, and (78.57 ± 0.16)%, respectively, demonstrating a good performance of the model superior to many existing image-level, pixel-level, and region-level self-supervised contrastive learning methods and close to the fully- supervised pre-training method based on the large- scale labeled dataset ImageNet.@*CONCLUSION@#USRegCon facilitates the model to learn beneficial region representations from large amounts of unlabeled data to overcome the scarcity of labeled data and improves the deep model performance for glomerular ultrastructure recognition and boundary segmentation.

Comparison of the polishing effects of polyetheretherketone materials under different chairside polishing systems / 口腔疾病防治

Objective @# The polishing effects of different compositions of chairside polishing systems on polyetheretherketone (PEEK) were compared to provide a reference for the rational selection of polishing systems for this material in clinical settings. @*Methods @#A total of 108 specimens were made from ShushijieTMPEEK crown and bridge materials, Bio-PAEK® dental PEEK, and BioHPP® PEEK. Thirty-six specimens of each material were randomly divided into 6 groups on average based on their polishing technique: OptiDisc®, Super-Snap® Rainbow Technique Kit, VITA ENAMIC®Clinical Polishing Set, Sof-LexTM Diamond Polishing System, Visio.lign Finishing Kit for Composite Veneers, and CERAMAGE Polishing Kit, LavaTM Ultimate ceramic and VITA ENAMIC ceramics were set as the control groups, and 6 specimens were made in each material, polished by Sof-LexTM Diamond Polishing System and VITA ENAMIC® Polishing Set clinical, respectively, according to the manufacturers’ suggestions. The surface roughness (Ra value and Sa value) and gloss of each set were measured. The surface morphologies of the polished specimens were observed by scanning electron microscopy.@*Results @#Surface roughness (Ra value and Sa value) and gloss were mainly influenced by the type of polishing system, and they varied between PEEK material types. The Sof-LexTM Diamond Polishing System produced the highest surface roughness and the lowest gloss values for PEEK materials, while the Super-Snap® Rainbow Technique Kit, Visio.lign Finishing Kit for Composite Veneers and CERAMAGE Polishing Kit resulted in low surface roughness values. The Visio.lign Finishing Kit for Composite Veneers and CERAMAGE Polishing Kit exhibited high gloss values. Polishing paste particles were observed embedded on the surfaces of the PEEK materials polished by the Visio.lign Finishing Kit for Composite Veneers; the surfaces of specimens polished by the CERAMAGE Polishing Kit were smooth, without polishing paste particle residue. Using the same polishing system, the best polishing results were obtained with BioHPP® among the PEEK materials tested. The surface roughness values of the three tested PEEK materials polished by the CERAMAGE Polishing Kit were similar to those of the LavaTM Ultimate ceramic and VITA ENAMIC ceramic, but the gloss was higher than that of both. @*Conclusion @# CERAMAGE Polishing Kit was recommended for polishing all three tested PEEK materials, achieving a good polishing effect, with similar surface roughness and higher gloss characteristics comparable to those of polished computer-aided design and manufacturing (CAD/CAM) resin-matrix ceramics.