Morphofunctional analysis of fibroblast-like synoviocytes in human rheumatoid arthritis and mouse collagen-induced arthritis

Abstract Background Fibroblast-like synoviocytes (FLS) play a prominent role in rheumatoid synovitis and degradation of the extracellular matrix through the production of inflammatory cytokines and metalloproteinases (MMPs). Since animal models are frequently used for elucidating the disease mechanism and therapeutic development, it is relevant to study the ultrastructural characteristics and functional responses in human and mouse FLS. The objective of the study was to analyze ultrastructural characteristics, Interleukin-6 (IL-6) and Metalloproteinase-3 (MMP-3) production and the activation of intracellular pathways in Fibroblast like synoviocytes (FLS) cultures obtained from patients with rheumatoid arthritis (RA) and from mice with collagen-induced arthritis (CIA). Methods FLSs were obtained from RA patients (RA-FLSs) (n = 8) and mice with CIA (CIA-FLSs) (n = 4). Morphology was assessed by transmission and scanning electron microscopy. IL-6 and MMP-3 production was measured by ELISA, and activation of intracellular signaling pathways (NF-κB and MAPK: p-ERK1/2, p-P38 and p-JNK) was measured by Western blotting in cultures of RA-FLSs and CIA-FLSs stimulated with tumor necrosis factor-alpha (TNF-α) and IL-1β. Results RA-FLS and CIA-FLS cultures exhibited rich cytoplasm, rough endoplasmic reticula and prominent and well- developed Golgi complexes. Transmission electron microscopy demonstrated the presence of lamellar bodies, which are cytoplasmic structures related to surfactant production, in FLSs from both sources. Increased levels of pinocytosis and numbers of pinocytotic vesicles were observed in RA-FLSs (p < 0.05). Basal production of MMP-3 and IL-6 was present in RA-FLSs and CIA-FLSs. Regarding the production of MMP-3 and IL-6 and the activation of signaling pathways, the present study demonstrated a lower response to IL-1β by CIA-FLSs than by RA-FLSs. Conclusion This study provides a comprehensive understanding of the biology of RA-FLS and CIA-FLS. The differences and similarities in ultrastructural morphology and important inflammatory cytokines shown, contribute to future in vitro studies using RA-FLS and CIA-FLS, in addition, they indicate that the adoption of CIA-FLS for studies should take careful and be well designed, since they do not completely resemble human diseases.

Effect of cleanser solutions on the retention force of oring attachment: an in vitro study

Abstract The aim of this study was to evaluate the effect of cleaning solutions on the retention force of o-ring-type overdenture attachments. The effect of four solutions on nitrile rings were evaluated: Cepacol (C), Cepacol with fluoride (CF), Listerine (L) and 0.05% sodium hypochlorite (SH); deionized water (DW) was used as a control. Matrices containing two implants and abutments and acrylic specimens with the metal capsules were obtained and divided into the groups. A simulation of 90 overnight immersions (8 h) was performed, and the tensile strength value was obtained at the beginning (T0) and in every 30 days (T1, T2 and T3) (n=6). In order to analyze o-ring surface damage after the immersions, a scanning electron microscopy (SEM) was used (n=1). For statistical analysis of the results, analysis of variance (ANOVA) and multiple comparisons with Bonferroni adjustment (test power=1.000; a=0.05) were used. There was a significant difference for the factors time (p<0.001), solution (p<0.001) and for the interaction time × solution (p<0.001). Considering the times of each solution, only for DW there was no significant loss of retention over time. Comparing the solutions in each moment, there was no difference among the solutions in T0. From T1, CF and SH provided less retention than DW (p<0.005). Through SEM it was possible to observe changes in the surface of the CF and SH nitrile o-rings. CF and SH should be avoided due to deleterious action in o-rings.

Resumo O objetivo do estudo foi avaliar o efeito de soluções higienizadoras sobre a força de retenção de encaixes do tipo o-ring. Foram avaliadas quatro soluções: Cepacol (C); Cepacol com flúor (CF), Listerine (L), hipoclorito de sódio 0,05% (HS) e água deionizada (controle/AD) em o-rings de nitrilo. Matrizes contendo dois implantes e pilares e espécimes em acrílico com as cápsulas metálicas foram obtidas e divididas entre os grupos. Foi realizada a simulação de 90 imersões noturnas (8 h), sendo obtido o valor da resistência à tração no início e a cada 30 dias (T0, T1, T2 e T3) por meio da máquina de ensaios mecânicos (n=6). Microscopia eletrônica de varredura (MEV) foi utilizada para análise de danos na superfície do o´ring após a imersão (n=1). Para análise estatística dos resultados foi utilizada análise de variância (ANOVA) e múltiplas comparações com ajuste de Bonferroni (poder do teste=1,000; a=0,05). Houve diferença significante para os fatores tempo (p<0,001), solução (p<0,001) e para interação de tempo × solução (p<0,001). Considerando-se os tempos de cada solução, apenas AD não apresentou perda significativa de retenção ao longo do tempo. Comparando as soluções em cada momento, não houve diferença entre as soluções em T0. A partir de T1, CF e HS propiciaram menor retenção quando comparados à AD (p <0,005). Através do MEV foi possível observar alterações nas superfícies dos o-rings de nitrilo imersos em CF e HS. O Cepacol com flúor e hipoclorito de sódio devem ser evitados devido à ação deletéria nos o-rings.

Estudo das propriedades físicas de um biomaterial com nova composição de wollastonita e beta fosfato tricálcico para regeneração óssea após implante in vivo / Study of the physical properties of a biomaterial with a new composition of wollastonite and beta-tricalcium phosphate for bone regeneration after implantation in vivo

Introdução: associadas à composição química, as propriedades físicas dos biomateriais como formato, dimensões e porosidade, são fatores que influenciam na biocompatibilidade, biodegradabilidade e nos potenciais osteoindutivo e osteocondutores. Objetivo: identificar modificações físicas no formato, dimensões e porosidade de um biomaterial com nova composição de wollastonita e beta fosfato tricálcico, implantado em defeitos ósseos críticos em calvária de ratos. Metodologia: trata-se de um estudo exploratório, com um biomaterial compósito, antes e após a sua implantação in vivo. Utilizou-se explantes cirúrgicos de calvárias de ratos que receberam implantes em defeito ósseo crítico. Os animais foram distribuídos em 3 grupos experimentais aleatoriamente, compostos por 5 animais cada, e avaliados com 15, 45 e 120 dias. Os grupos foram denominados: G0-biomaterial; GI-15 dias; GII-45 dias; e, GIII-120 dias. As amostras foram micrografadas em microscópio eletrônico de varredura, com diferentes magnificações. Utilizouse o software livre ImageJ para processamento das imagens e análise das partículas e poros. Resultados: a distribuição espacial do biomaterial promoveu preenchimento completo do defeito ósseo crítico. Micrografias com diferentes magnificações permitiu identificar modificações na área de contato entre grânulos, diminuição dos poros intergranular, aumento da área ocupada pelos poros e diminuição das partículas nos grânulos. Nos grupos GII e GIII, identificou-se formação de componentes orgânicos na superfície do implante. Conclusão: houve modificações físicas no formato, dimensões horizontais, distribuição espacial e porosidade da superfície dos grânulos do biomaterial, relacionadas com a biodegradabilidade e o potencial osteoindutivo e osteocondutor do biomaterial.

Introduction: associated with the chemical composition, physical properties of biomaterials related to their format, dimensions and porosity, are factors that influence on biocompatibility, biodegradability and osteoinductive and osteoconductive potential. Objective: identify physical changes in the format, dimensions and porosity of biomaterial with new composition of wollastonite and beta tricalcium phosphate, implanted in critical bone defects in calvaria of rats. Methodology: this is an exploratory study, with a composite biomaterial before and after its implantation in vivo. Used surgical explants of rat calvarium that received biomaterial implants into the critical bone defect. The animals were divided into 3 experimental groups of random distribution, composed of 5 animals each, and evaluated for 15, 45 and 120 days. The groups were named: G0-Biomaterial; GI-15 days; GII-45 days; and, GIII-120 days. The samples were studied by micrography in scanning electronic microscope with different magnifications. It was used the free software ImageJ to image processing and particles and pores analysis. Results: the spatial distribution of the biomaterial promoted full filling of the critical bone defect. Micrographs with different magnifications allowed to identification of modifications in the area of contact between granules, decrease of the intergranular pores, increase of the area occupied by the pores and decrease of the particles in the granules. In GII, and GIII groups, it was identified formation of organic components on the surface of the implant. Conclusion: there were physical modifications in the format, horizontal dimensions, spatial distribution and porosity of the biomaterial, related to the biodegradability and the osteoinductive and osteoconductive potential of the biomaterial.

Preparation and Characterization of Macroporous Hydrogels from Copolymers Networks

New hydrogels based on (MAA) and (NVP) copolymers crosslinked with (BAA), were prepared by free radical cross-linkingcopolymerization, with a NVP percent molar composition of 10, 47.5 and 85. These hydrogels have been characterized by(FTIR), (SEM), (TGA /DSC) coupling. The results show four steps of degradation. The degradation rate is inverselyproportional to the mole percent of NVP, and SEM shows that the hydrogels have a pore size between 7.14 to 13.33 μm.

Calcium pyrophosphate dihydrate deposition disease in the temporomandibular joint: diagnosis and treatment / 대한악안면성형재건외과학회지

BACKGROUND: Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare disease in the temporomandibular joint (TMJ) space. It forms a calcified crystal mass and induces a limitation of joint movement. CASE PRESENTATION: The calcified mass in our case was occupied in the left TMJ area and extended to the infratemporal and middle cranial fossa. For a complete excision of this mass, we performed a vertical ramus osteotomy and resected the mass around the mandibular condyle. The calcified mass in the infratemporal fossa was carefully excised, and the segmented mandible was anatomically repositioned. Scanning electronic microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) microanalysis was performed to evaluate the calcified mass. The result of SEM/EDS showed that the crystal mass was completely composed of calcium pyrophosphate dihydrate. This result strongly suggested that the calcified mass was CPDD in the TMJ area. CONCLUSIONS: CPDD in the TMJ is a rare disease and is difficult to differentially diagnose from other neoplasms. A histological examination and quantitative microanalysis are required to confirm the diagnosis. In our patient, CPDD in the TMJ was successfully removed via the extracorporeal approach. SEM/EDS microanalysis was used for the differential diagnosis.

Aspectos morfológicos e ultraestruturais de células sanguíneas de Crotalus durissus terrificus / Morphological and ultrastructural aspects of Crotalus durissus terrificus blood cells

A avaliação hematológica, de importância comprovada como um meio auxiliar de diagnóstico ao clínico de pequenos animais domésticos, vem se tornando comum em animais selvagens não apenas para a clínica, mas para a avaliação do manejo e como estudo auxiliar para a fisiologia das várias espécies. Tendo em vista o aumento da demanda para a produção de várias drogas de importância farmacêutica, a criação de serpentes peçonhentas vem se tornando comum a ponto destes animais já serem reconhecidos como sendo de produção. O conhecimento do manejo e da clínica destes animais ainda é escasso e a mortalidade é elevada nos criatórios, tornando urgente a ampliação destes. Embora alguns estudos hematológicos já tenham sido realizados em cascavéis (Crotalus durissus) os dados analisados ainda são insipientes, notadamente em relação à caracterização das células do sangue e poucos estudos em microscopia eletrônica foram realizados em serpentes. Com o objetivo de caracterizar as células sanguíneas morfologicamente, sob microscopia óptica e ultraestrutural, foram coletadas amostras de sangue de 52 de indivíduos da subespécie Crotalus durissus terrificus para a realização de esfregaços sanguíneos e avaliação ultraestrutural. Concluiu-se que a coloração hematológica de Giemsa permite a avaliação morfológica e a diferenciação das células sanguíneas em serpentes assim como a visualização de hemoparasitos. A avaliação ultraestrutural permite evidenciar as organelas celulares e a diferenciação entre as células, inclusive entre os tipos leucocitários, porém ainda são necessários outros estudos para que seja elucidada a hipótese da existência dos eosinófilos na espécie estudada assim como é necessária melhor caracterização dos grânulos dos azurófilos para que se confirme uma possível diferença entre os monócitos típicos e os azurófilos.(AU)

Hematological evaluation, important for the diagnostic by the small domestic animal clinician, has become common in wildlife clinic, and for handling and study of the physiology of various species. Given the increased demand for drug production of pharmaceutical importance, the breeding of venomous snakes has become common and is already recognized as production. Knowledge of the management and clinics of snakes is still insufficient and their mortality is high. Although some hematological studies have already been conducted in the rattlesnake (Crotalus durissus), the analyzed data are still insufficient, especially with respect to the characterization of blood cells, and few electron microscopy studies have been performed on snakes. In order to characterize morphologically blood cells with light and ultrastructural microscopy, blood samples from 52 individuals of subspecies of Crotalus durissus terrificus were collected to perform blood smears and ultrastructural evaluation. It was concluded that hematologic Giemsa staining allows morphological evaluation and differentiation of the blood cells as well as of snake hemoparasites. The ultrastructural evaluation will highlight the cell organelles and differentiation between cells, including leukocyte types; although still further studies are needed to elucidate the hypothesis of eosinophils in the species studied as also is necessary a better characterization of azurophilic beads to confirm a possible difference between the typical monocyte and the azurophilic.(AU)

The Occluding Effect of Penetrating Resin Combined with Ethanol Wet-bonding on Dentin Tubule / 中国医科大学学报

Objective To compare the occluding effect of conventional penetrating resin,Single Bond desensitizer,and penetrating resin combined with ethanol wet-bonding on dentin tubules.Methods Sixty isolated premolar teeth were prepared to form dentin discs.The 60 teeth were divided into 3 groups based on a random number table:Group A,conventional penetrating resin;Group B,Single Bond desensitizer,and Group C,penetrating resin combined with ethanol wet-bonding.Each group comprised 20 teeth.Dentin discs were split in half along the longitudinal axis.Half of the disc served as the control;the other half was coated with desensitizer.Microscopic characteristics of the dentin surface and profile were determined by using a field emission scanning electron microscope.Results In group A,70.10％±2.13％ of the dentin tubule openings were covered by the resin.The penetration depth was 50±10.59 μm,and the resin was short and discontinuous.In group B,86.35％±1.73％ of the dentin tubules openings were covered.The penetration depth was 69± 11.98 μm,and the resin was sparse.In group C,95.65％± 1.46％ of dentin tubules openings were covered.The penetration depth was 177±9.17 μm,and the resin was compact and filled.Conclusion Penetrating resin combined with ethanol wet-bonding occludes dentin tubules better than conventional penetrating resin and Single Bond desensitizer.

Effect of the use of different periodontal curettes on the topography and roughness of root surface

Introduction: Periodontal scaling is the treatment approach most used to remove dental calculus, plaque, and altered cementum from root surface. During root decontamination, the instruments used leave the root rougher and more irregular. Objective: To verify the root surface after mechanical scaling with different Gracey curettes steel through SEM and superficial roughness analyses. Material and methods: Twelve teeth were embedded in acrylic resin. The teeth were instrumented with new Gracey curettes Gracey 5/6 from different brands. The groups (n=2) were divided into: control, no instrumentation (GC); carbon steel (CSN); stainless steel Neumar (SSN); stainless steel Millenium (SSM); premium steel Neumar (PSN); Hu-Friedy (HF). An area measuring 3 x 3 mm2 was marked on the distal surface of the root to guide the Reading of the root topography on SEM and rugosimeter. The data were analyzed by a single examiner previously calibrated. SEM analysis was based on scores of the root surface smoothness after scaling. We analyzed the parameters of mean roughness (Ra) and mean roughness deepness (Rz). SEM data were submitted to statistical analysis through Fisher's exact test (p < 0.002) and roughness data by Anova followed by Student t test. Results: The quality of the active surface of the curette demonstrated by SEM and roughness analyses that it can exert difference in the result regarding to the homogeneity produced after the scaling of root surface. Group SSM demonstrated a homogenous root surface (score 0) in SEM and better smoothness in rugosimeter analysis. Conclusion: According to com the methodology used, the group of curettes that provided better smoothness of root surface after scaling was SSM.

Association between Clonorchis sinensis infection and the subtypes of mixed gallbladder stones / 中华肝胆外科杂志

Objective A systematic study to classify mixed gallbladder stones to determine their relationship with Clonorchis sinensis infection.Methods 349 consecutive patients with mixed gallbladder stones were enrolled into this study and their gallstones were studied.The material composition of gallbladder stones was analyzed using Fourier Transform Infrared spectroscopy,and the distribution and microstructure of the material components were studied using Scanning Electron Microscopy.The composition and distribution of the elements were analyzed by an X-ray energy spectrometer.Gallbladder stones were classified accordingly,and the stones were then grinded for microscopic examination.The stones were divided into two groups based on the results of detection of clonorchis sinensis eggs.Patients were also divided into two groups according to the patients' region (high-incidence and low-incidence regions of Clonorchis sinensis infection).The diversity of the subtypes of mixed gallbladder stones was compared.Results 14 subtypes were found,including Bilirubinate-calcium carbonate mixed stones (n =134),Cholesterol-bilirubinate mixed stones (n =87),Bilirubinate-phosphate mixed stones (n =39),Cholesterol-calcium carbonate mixed stones (n =30),Cholesterol-bilirubinate-calcium carbonate mixed stones (n =15),etc.Bilirubinate-calcium carbonate mixed stones were the main subtype of egg-positive mixed gallbladder stones and the patients were from high-incidence regions.Cholesterol-bilirubinate mixed stones were the main subtype of egg-negative mixed gallbladder stones and patients were from low-incidence regions.The differences of the subtypes constituent between the high-incidence and low-incidence regions groups were significant (P ＜ 0.05),and between the egg-positive and egg-negative groups were also significant (P ＜ 0.05).Conclusions The most common subtypes of mixed gallbladder stones were bilirubinate-calcium carbonate mixed stones,while the second was cholesterol-bilirubinate mixed stones.Clonorchis sinensis infection was mainly associated with Bilirubinatecalcium carbonate mixed stones.

Ryanodine receptor 1 and its potential gating mechanism: Recent progress / 第二军医大学学报

The ryanodine receptors (RyRs) are intracellular Ca2+ releasing channels on the sarcoplasmic reticulum membrane and play a pivotal role in theexcitation-contraction coupling of skeletal and cardiac muscles as well as other physiological processes. With the recent development of CryoEM and the improvement of data analysis technique, scientists from China, the United States and Germany have acquired high-quality RyR1 images at the total resolutions of 3. 8 Å (1 Å = 10-10 m), 4. 8 Å and 6. 1 Å, respectively, which have been published in the same issue of Nature in 2015. RyRls are homotetrameric complexes with a molecular mass of more than 2 200 000, mainly containing a cytoplasmic region composed of NTD, SPRY, P1, P2, B-sol and C-sol domains and a channel region composed of S1-S6, VSL and CTD domains. As the most common factor affecting the condition of RyRl, Ca2+ is able to bind the EF-hand subdomain in the cytoplasmic region, which further causes the conformational change and finally leads to the channel opening.

Growth inhibition and morphological alterations of Staphylococcus aureus caused by the essential oil of Aloysia triphylla / Inhibición del crecimiento y alteraciones morfológicas de Staphylococcus aureus causadas por el aceite esencial de Aloysia triphylla

Aloysia triphylla essential oil (EO) has antimicrobial activity on Staphylococcus aureus which is a pathogen responsible for severe infections and food contamination. The target of EO is mainly in the cytoplasmic membrane. In this work the mechanisms of action of the EO of A. triphylla on S. aureus were investigated. A. triphylla was collected from La Paz. The oil was analyzed by GC-MS. The antimicrobial effects were evaluated by MIC, MBC, killing time and TEM. MIC values were 23 μg/mL for 6.3 x 104 CFU/mL, 92 μg/mL for 5.71 x 105 CFU/mL and 180 μg/mL for 9 x 106 CFU/mL. The MBC was 5920 μg/mL for all cellular concentrations and it was necessary more time to kill bigger cell populations. Multilamellar and mesosome-like structures on the membrane were seen by TEM. A. triphylla oil is an antibacterial compound against S. aureus which main mechanism of action seems to be the cytoplasmic membrane disruption.

El aceite esencial (AE) de Aloysia triphylla posee actividad antimicrobiana contra Staphylococcus aureus, patógeno responsable de infecciones nosocomiales e alimenticias. El blanco de acción de los AE es la membrana citoplasmática. El mecanismo de acción del AE de A. triphylla sobre S. aureus fue investigado. El AE de A. triphylla (La Paz, Argentina) fue analizado por CG-EM. Se evaluó́ el efecto antimicrobiano por CIM, CBM, tiempo de muerte y MET. Los valores de CIM fueron 23 μg/mL para 6.3 x 104 UFC/mL, 92 μg/mL para 5.71 x 105 UFC/mL y 180 μg/mL para 9 x 106 UFC/mL. La CBM fue 5920 μg mL para todas las concentraciones celulares estudiadas. El tiempo de muerte fue determinado; necesitando mayor tiempo para matar una población celular elevada. Fueron observados por MET estructuras multilamerales y semejantes a mesosomas. El AE de A. triphylla es un potencial compuesto antibacteriano contra S. aureus donde su principal mecanismo de acción es por disrupción de la membrana citoplasmática.

Cytolytic and systemic toxic effects induced by the aqueous extract of the fire coral Millepora alcicornis collected in the Mexican Caribbean and detection of two types of cytolisins

Background Millepora alcicornis is a branching hydrocoral common throughout the Caribbean Sea. Like other members of this genus, this species is capable of inducing skin eruptions and blisters with severe pain after contact. In the present study, we investigated the toxicity of theM. alcicornis aqueous extract on several animal models. Considering that some cnidarian hemolysins have been associated to local tissue damage, since they also induce lysis of other cell types, we also made a partial characterization of the hemolytic activity of M. alcicornis aqueous extract. This information is important for understanding the defense mechanisms of the "fire corals".Methods The effects of pH, temperature, and some divalent cations on the hemolytic activity of the extract were assayed, followed by a zymogram analysis to detect the cytolysins and determine their approximate molecular weight. The toxicity of the aqueous extract was assayed in mice, by intravenous administration, and histopathological changes on several tissues were analyzed by light microscopy. The toxicity of the extract was also tested inArtemia salina nauplii, and the damages caused on the crustaceans were analyzed by transmission and scanning electron microscopy.Results The hemolytic activity of the hydrocoral extract was enhanced in the presence of Ca 2+ (≥2 mM), Mg 2+ (≥6 mM), and Ba2+ (≥0.1 mM); however, it was reduced in the presence of Cu2+(≥0.1 mM), Zn 2+ (≥6 mM), and EDTA (≥0.34 mM). Differences in the pH did not affect the hemolytic activity, but it was temperature-sensitive, since preincubation at ≥ 50 °C sharply reduced hemolysis. The zymogram showed the presence of two types of hemolysins: ~ 28-30 kDa proteins with phospholipase A 2 activity and ~ 200 kDa proteins that do not elicit enzymatic activity. The aqueous extract of this cnidarian was lethal to mice (LD 50 = 17 μg protein/g), and induced kidney, liver, and lung damages. Under denaturing conditions, the aqueous extract completely lost its toxic and hemolytic activities.Conclusions The results showed that the M. alcicornis aqueous extract contains two types of thermolabile hemolysins: proteins of approximately 28-30 kDa with PLA 2 activity, while the others are larger proteins of approximately 200 kDa, which do not possess PLA 2activity. Those thermolabile cytolysins, which are stable to pH changes and whose activity is calcium dependent, are capable of inducing damage in lung, kidney and liver tissues, resulting in a slow death of mice. M. alcicorniscytolysins also provoke tissue dissociation inArtemia salina nauplii that might be attributed to pore forming mechanisms.(AU)

Cytolytic and systemic toxic effects induced by the aqueous extract of the fire coral Millepora alcicornis collected in the Mexican Caribbean and detection of two types of cytolisins

Background Millepora alcicornis is a branching hydrocoral common throughout the Caribbean Sea. Like other members of this genus, this species is capable of inducing skin eruptions and blisters with severe pain after contact. In the present study, we investigated the toxicity of theM. alcicornis aqueous extract on several animal models. Considering that some cnidarian hemolysins have been associated to local tissue damage, since they also induce lysis of other cell types, we also made a partial characterization of the hemolytic activity of M. alcicornis aqueous extract. This information is important for understanding the defense mechanisms of the fire corals.Methods The effects of pH, temperature, and some divalent cations on the hemolytic activity of the extract were assayed, followed by a zymogram analysis to detect the cytolysins and determine their approximate molecular weight. The toxicity of the aqueous extract was assayed in mice, by intravenous administration, and histopathological changes on several tissues were analyzed by light microscopy. The toxicity of the extract was also tested inArtemia salina nauplii, and the damages caused on the crustaceans were analyzed by transmission and scanning electron microscopy.Results The hemolytic activity of the hydrocoral extract was enhanced in the presence of Ca 2+ (2 mM), Mg 2+ (6 mM), and Ba2+ (0.1 mM); however, it was reduced in the presence of Cu2+(0.1 mM), Zn 2+ (6 mM), and EDTA (0.34 mM). Differences in the pH did not affect the hemolytic activity, but it was temperature-sensitive, since preincubation at 50 °C sharply reduced hemolysis. The zymogram showed the presence of two types of hemolysins: ~ 2830 kDa proteins with phospholipase A 2 activity and ~ 200 kDa proteins that do not elicit enzymatic activity. The aqueous extract of this cnidarian was lethal to mice (LD 50 = 17 g protein/g), and induced kidney, liver, and lung damages. Under denaturing conditions, the aqueous extract completely lost its toxic and hemolytic activities.Conclusions The results showed that the M. alcicornis aqueous extract contains two types of thermolabile hemolysins: proteins of approximately 2830 kDa with PLA 2 activity, while the others are larger proteins of approximately 200 kDa, which do not possess PLA 2activity. Those thermolabile cytolysins, which are stable to pH changes and whose activity is calcium dependent, are capable of inducing damage in lung, kidney and liver tissues, resulting in a slow death of mice. M. alcicorniscytolysins also provoke tissue dissociation inArtemia salina nauplii that might be attributed to pore forming mechanisms.

Assessment of canal centering ability and topography of three nickel-titanium rotary systems / Avaliação da centralização do preparo e da topografia de três sistemas rotatórios de níquel-titânio

Objective: This study aimed to evaluate the canal cen-tering ability and topography of BioRaCeTM (BR), Wi-zard CD PlusTM (WP), and Wizard NavigatorTM (WN) instruments. Materials and method: mesiobuccal roots of upper first molars were selected and randomly dis-tributed in three groups (n=10), according to the rota-ry system used for instrumentation. Canal transporta-tion was assessed at 2, 4, 6, and 8 mm from the root apex, by subtracting cone bean computed tomography (CBCT) images taken before and after preparation. The root canal center was marked in pre- and post-prepa-ration images, and the distance between these points was measured in bucco-palatal (BP) and mesio-distal (MD) directions. New instruments were analyzed un-der scanning electron microscopy (SEM) regarding their surface finishing, topographical features, and surface defects. The SEM images were obtained at the tip of the instrument, and at 5 mm from the tip. Data of the canal centering ability were analyzed by two-way ANOVA (? = 0.05). Results: regardless of root level (2, 4, 6, and 8 mm), all groups presented canal transportation in both directions. Significant differences were not detected (p > 0.05). Surface finishing was regular in the BR group with rounded transitional angle. Cutting edges had a sharp angle in BR and WN groups, while WP instru-ments had a flattened angle. Conclusion: despite such topographical differences between the rotary instru-ments tested, none of them were able to exactly main-tain the original root canal center, and no significant differences were observed among groups.

Adhesion and formation of tags from MTA Fillapex compared with AH Plus® cement

Introduction and Objective: The aim of this study was two-fold: 1) to evaluate, in vitro, the shear bond strength of two sealers by push-out test and 2) to assess the failures after displacement. Additionally, the formation of tags was observed by SEM. Material and methods: Forty mandibular premolars were selected and the canals were subjected to biomechanical preparation with rotary instruments. These specimens were divided into two groups according to the sealer (n = 20): GI - MTA Fillapex and GII - AH Plus. All roots were filled with sealer only, without gutta-percha. After a period corresponding to three times the setting time of the sealer, the roots were sectioned transversely into slices of 1 mm thickness, to obtain one slice from the cervical third, to be used in the push-out test. Following, two slices of each group were randomly chosen for ultrastructural analysis by scanning electron microscopy (SEM). The data obtained in shear bond strength test were subjected to statistical analysis. Results: AH Plus cement exhibited higher shear bond strength values (1.332±0.75 MPa) than MTA Fillapex (0.071±0.07 MPa), with statistically significant differences. Conclusion: MTA Fillapex has a low bond strength with less formation of tags than AH Plus.

Syslematic classification of gallbladder stones / 中华肝胆外科杂志

Objective To develop a classification of gallbladder stones,to analyze the clinical characteristics of each type of stone and to provide a theoretical basis for the formation of different types of gallbladder stones.Method 925 consecutive patients with gallbladder stones were enrolled and their gallstones were studied.The material composition of the gallbladder stones was analyzed using fourier transform infrared spectroscopy and the distribution and microstructure of the material components were observed using scanning electron microscopy.The composition and distribution of the elements were analyzed by an X-ray energy spectrometer.Gallbladder stones were classified accordingly.Results The gallbladder stones were classified into 8 types and more than ten subtypes,including cholesterol stones (n =334),pigment stones (n =246),calcium carbonate stones (n =167),phosphate stones (n =14),calcium stearate stones (n =11),protein stones (n =3),cystine stones (n =1) and mixed stones (n =149).Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar.A total of 11 subtypes of mixed stones were found in this study.Conclusion The systematic classification of gallbladder stones indicated that different types of stones had different characteristics in terms of infrared spectrogram,microstructure,elemental composition and distribution,thus providing an important basis for the mechanistic study of gallbladder stones.

Análisis topográfico de la superfície de implantes de titanio comercialmente puro a través de microscopía electrónica de barrido / Topographic analysis of the surface of commercially pure titanium implants by scanning electronic microscopy

Este trabajo tiene como objetivo analizar topográficamente la superficie de implantes de titanio comer-cialmente puros. Fueron seleccionados ocho implantes de las siguientes fabricantes: Conexáo - Sistema de Próteses; Lifecore - Biomedical; AS Technology y S - Serson Internacional. Las muestras presentaban tratamiento de la superficies, a través de las técnicas de ataque acido (Conexáo) y plasma spray de titanio (Lifecore-Biomedical; AS Technology y S -Serson International), siendo divididas en cuatro grupos, conteniendo dos implantes del mismo lote de cada fabricante. Los análisis fueron realizados a través de microscopia electrónica de barredura (MEB). Los estudios a través de MEB revelaron la topografía rugosa de la superficie y la uniformidad de las áreas entre las roscas de los implantes. Se puede concluir que todas las muestras presentaron rugosidad en la superficie, con diferencias en la micromorfología entre todos los implantes.

The aim of this research is to analyze the pure titanium dental implant surface. An 8 implant device of Conexáo - Sistema de Próteses; Lifecore - Biomedical; AS Technology y S - Serson Internacional was selected. The simple presented surface treatment with acid attack or titanium plasma spray, being analyzed in 4 groups with two implants in each. Those analyzed were realized with a scanning electron microscope showing the topography and structure between different part of the implant. It was concluded that all implant systems show surface roughness with differences in the micro-morphology among all implant groups.

Comparison of different wear burs after cavity preparation and sterilization methods / Comparação do desgaste de diferentes pontas após preparo cavitário e diferentes métodos de esterilização

Objetivo: Avaliar a perda estrutural e alteração morfológica da superfície de diferentes instrumentos de corte após preparo cavitário e diferentes métodos de esterilização. Material e Método: Cavidades padronizadas na superfície vestibular de incisivos bovinos foram realizadas na região do limite cemento-esmalte usando cinco diferentes tipos de instrumentos de corte (n= 4): Ca- broca cilíndrica Carbide #56 (KG Sorensen), Kg- ponta diamantada cilíndrica #1093 (KG Sorensen), Mi- ponta diamantada cilíndrica #1093 (Microdont), Fa- ponta diamantada cilíndrica #1093 (Fava) e Cv- ponta diamantada cilíndrica artificial #8,2137 (CVDentUS). Cada ponta foi submetida a um ciclo que envolveu a realização de microscopia eletrônica de varredura (MEV) inicial, preparo cavitário (PC), limpeza com ultrassom (US), três métodos de esterilização: glutaraldeído a 2% (Gl), estufa - calor seco (DH) ou autoclave - calor úmido (WH), e MEV final. Resultados: Foram encontradas diferenças significativas para a interação entre os fatores. Conclusão: O método de esterilização modifica estruturalmente os instrumentos de corte de modo diferente entre os tipos de instrumentos testados. O glutaraldeído foi o método que apresentou pior resultado para as brocas carbides. As pontas diamantadas apresentaram grande variabilidade de resultados para a interação dos fatores desgaste de instrumentos de corte e processos de esterilização.

Objective: evaluate the loss of mass and the morphologic surface alteration of different cutting instruments after cavity preparation from dental structure and different methods of sterilization. Material and Method: standardized cavities in the buccal surface of bovine incisors had been carried through in the region of the limit enamel-cementum using five different types of cut instruments (n=4): Ca- cylinder carbide bur #56 (KG Sorensen), Kg- cylindrical diamond bur #1093 (KG Sorensen), Mi- cylindrical diamond bur #1093 (Microdont), Fa- cylindrical diamond bur #1093 (Fava) and Cv- cylindrical artificial diamond bur #8.2137 (CVDentUS). Each tip was submittes to a cycle that involved: Initial Scanning Electron Microscopy (SEM), cavity preparation (PC), clean-up ultrasonic (US), three methods of sterilization: glutaraldehyde 2% (Gl), dry heat (DH) or wet heat (WH) and final SEM. Results: significant difference for the interaction between factors was found. Conclusion: the sterilization method modifies structurally the cut instruments in different way among types of the instruments tested. Glutaraldehyde proved to be the worst method for sterilizing carbide bur. The diamond instruments showed great variability of results for the interaction of wear of cutting instruments and sterilization processes.

Biofilm production by clinical Staphylococci strains from canine otitis

This study determined the species of 54 staphylococci isolates from canine otitis and their ability to produce biofilm through the Congo red agar method, confirmed by scanning electron microscopy. The most frequently identified species were S. intermedius and S. simulans. Results showed that 30% of the strains were biofilm producers.

Influência do tratamento de superfície na adaptação externa de cavidade classe V hígida e afetada por cárie submetidas á ciclagem térmica / Influence of surface treatment on the external adaptation of class V healthy and caries affected cavities submited to thermal cycling

O presente trabalho propôs avaliar a utilização de clorexidina e laser de Er,Cr:YSGG no processo de adaptação externa em restaurações de cavidades hígidas e afetadas por cárie submetidas a ciclagem térmica. Foram realizados preparos cavitários mistos de classe V vestibular em 36 molares humanos, dos quais metade foram induzidos artificialmente à cárie. Os dentes foram subdivididos em 6 grupos, cavidade hígida: sem tratamento prévio, utilização de clorexidina e utilização de laser de Er,Cr:YSGG e cariados: sem tratamento prévio, utilização de clorexidina e utilização de laser de Er,Cr:YSGG. Foi empregado o sistema adesivo Single Bond 2 (3M ESPE, St. Paul, MN, EUA) e resina composta Filtek Z350 XT (3M ESPE, St. Paul, MN, EUA). Os espécimes foram submetidos a 3000 ciclos térmicos (5-55° C em banihos de 60 segundos). Para avaliação da adaptação externa foram obtidas réplicas de epóxi pela impressão da superfície das restaurações. Foi realizada a análise quantitativa da adaptação externa, tanto em dentina hígida quanto afetada, por meio de réplicas de epóxi, utilizando MEV. Os valores porcentuais de margem contínua mostraram que não houve diferença estatisticamente significante em relação aos diferentes tratamentos de superfície e a ciclagem térmica pode influenciar nos valores de adaptação quando comparado os valores antes e após a ciclagem

The present study proposed to evaluate the use of chlorhexidine and laser Er,Cr:YSGG in the process of external adaptation in mixed healthy and caries affected cavities subjected to thermal cycling. Mixed class V cavity preparations were performed on the buccal surface of 36 human molars, Half of them were artificially caries induced. After this procedure, the teeth received different forms of surface treatment: without previous treatment, use of chlorhexidine and the use of Er,Cr:YSGG. Adhesive system Single Bond 2 and Z350 XT composite resin were used to restoration. The specimens were subjected to 3000 thermal cycles (5- 55°C 60 seconds). Epoxy replicas were obtained and then observed under SEM to verify the external adaptation. It was concluded that the application of laser and chlorhexidine did not affect the percentages of marginal adaptation of Class V restorations. Furthermore, thermocycling may influence adaptation values