Historia del microscopio y su repercusión en la Microbiología / History of the microscope and its repercussion on Microbiology

El microscopio constituye un instrumento de vital importancia para la Microbiología y para muchas otras ramas de la Medicina. Se realizó una revisión bibliográfica con el objetivo de profundizar los conocimientos sobre el microscopio, sobre la historia de este en el período comprendido desde su creación hasta la actualidad a nivel mundial y más brevemente en Cuba. El trabajo aborda también, con una corta descripción, los diferentes tipos existentes, así como algunas de las aplicaciones más importantes en la Microbiología.

This bibliographic review was carried out with the objective to deepen the existing knowledge about the history of the microscope since its origin up to date worldwide which and in Cuba, taking into account that it constitutes an instrument of vital importance for microbiology and for many other branches of medicine. This work also deals with a brief description of the different types of microscopes as well as some of the most important applications in microbiology.

Efeito do modo de ativação de um cimento resinoso autoadesivo na espessura da linha de cimento de copings metálicos cimentados sobre pilares protéticos / Effect of the cure mode on the marginal opening of metal copings luted to implant abutments with a self-adhesive resin cement

O objetivo deste trabalho foi analisar a influência do tipo de cimento e do modo de ativação na espessura da linha de cimento de copings metálicos cimentados sobre pilares protéticos. Foram utilizados 6 pilares e 6 cilindros do sistema Cera One cimentados com cimento autoadesivo RelyX U200 (3M ESPE, St. Paul - EUA) e também um cimento de fosfato de zinco (S.S. White Artigos Dentários Ltda. - Rio de Janeiro - RJ - Brasil). Foram cimentados 2 cilindros com fosfato de zinco, 2 cilindros com RelyX fotoativado e 2 não fotoativados sendo levados ao microscópio eletrônico de varredura para mensuração da linha de cimento. A diferença entre os grupos foi pequena e o modo de ativação do cimento autoadesivo interfere pouco na espessura da linha de cimento de copings metálicos cimentados sobre pilares protéticos.

The aim of this study was to analyse the effect of the luting agent and the cure mode on the marginal opening of metal copings luted to implant abutments. To test a self-adhesive resin cement and a zinc phosphate cement, were used 6 abutments and 6 cylinders of the Cera One system. The cylinders were luted 2 with zinc phosphate cement, 2 with resin cement light cured and 2 with resin cement not light cured. Afterwards the cylinders were taken to SEM analysis to calculate the marginal opening. The cure mode has a little effect on the marginal opening of metal copings luted to implant abutments.

Effect of different cleansers on the surface of removable partial denture

Removable partial dentures (RPD) demand specific hygienic cleaning and the combination of brushing with immersion in chemical solutions has been the most recommended method for control of biofilm. However, the effect of the cleansers on metallic components has not been widely investigated. This study evaluated the effect of different cleansers on the surface of RPD. Five disc specimens (12 mm x 3 mm metallic disc centered in a 38 x 18 x 4 mm mould filled with resin) were obtained for each experimental situation: 6 solutions [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), 0.05 percent sodium hypochlorite (NaOCl), and distilled water (DW) control] and 2 Co-Cr alloys [DeguDent (DD) and VeraPDI (VPDI)] were used for each experimental situation. A 180-day immersion was simulated and the measurements of roughness (Ra, µm) of metal and resin were analyzed using 2-way ANOVA and Tukey’s test. The surface changes and tarnishes were examined with a scanning electronic microscopy (SEM). In addition, energy dispersive x-ray spectrometry (EDS) analysis was carried out at representative areas. Visually, NaOCl and MI specimens presented surface tarnishes. The roughness of materials was not affected by the solutions (p>0.05). SEM images showed that NaOCl and MI provided surface changes. EDS analysis revealed the presence of oxygen for specimens in contact with both MI and NaOCl solutions, which might suggest that the two solutions promoted the oxidation of the surfaces, thus leading to spot corrosion. Within the limitations of this study, it may be concluded that the NaOCl and MI may not be suitable for cleaning of RPD.

As próteses parciais removíveis (PPR) exigem higienização específica e a associação da escovação com imersão em soluções químicas tem sido o método mais recomendado para controle do biofilme. Entretanto, os efeitos destas soluções não são amplamente reportados em componentes metálicos. Este estudo avaliou o efeito de diferentes agentes de higienização na superfície dos componentes de uma PPR. Foram confeccionados 5 espécimes (disco metálico de 12 x 3 mm centralizado em uma tira de resina com 38 x 18 x 4 mm) para cada situação experimental: 6 soluções [Periogard (PE), Cepacol (CE), Corega Tabs (CT), Medical Interporous (MI), Polident (PO), hipoclorito de sódio 0,05 por cento (HS) e água destilada (AD) como controle)] e 2 ligas de cobalto-cromo [DeguDent (DD) e Vera PDI (VPDI)] foram utilizadas para cada situação experimental. Foram simuladas imersões de 180 dias. As aferições de rugosidade (Ra, μm) tanto em porção metálica quanto em resina acrílica termopolimerizável foram submetidos ao ANOVA e ao teste de Tukey. As alterações superficiais e manchas foram examinadas por meio de microscopia eletrônica de varredura (MEV). Áreas de interesse foram submetidas à espectrometria por energia dispersiva por raios X (EDS). Visualmente, puderam ser verificadas manchas nas superfícies metálicas quando utilizados HS e MI. A rugosidade dos materiais não foi afetada pelas soluções (p>0,05). As fotomicrografias evidenciaram que HS e MI ocasionaram alterações superficiais. As análises de EDS revelaram a presença de oxigênio nos grupos HS e MI, o que pode sugerir que estas duas soluções causaram oxidação das superfícies, provocando pontos de corrosão. Dentre as limitações do presente estudo, pode-se concluir que estas soluções não são apropriadas para a higienização das PPR.

A dynamic observation of pathologic and ultrastructural changes of perihematoma in intracerebral hemorrhage patients / 中国神经精神疾病杂志

Background In recent years,some researches had been conducted on the pathologic changes of the secondary injury of perihematoma in animal experiments,but only a few studies had been done on the dynamic pathologic and ultrastructural changes of the perihematoma in ICH patients. The unique contribution of our study is to investigate the dynamic pathologic and ultrastructural changes of the perihematoma in ICH patients and provide significant insights into how the pathophysiology and ultrastructures changed after ICH.Methods The written informed consents were obtained from the ICH patients or their relatives. 30 patients (the supertentorial hemotoma volume＞30 mi and the cerebellar hemotoma volume ＞10 mi) were divided into 8 groups according to the time passed after ICH:＜6 h (6 patients), 6 ～ 12 h (7 patients), 12 ～24 h (5 patients), 24～48 h (3 patients), 48 ～72 h (3 patients), 3 ～4 days group (3 patients), 5 days group (2 patients) and 8 days group ( 1 patient) and subjected to craniotomy for hemotoma evacuation. During the operation for the hemotoma's evacuation, a small amount of tissues that must be removed, which located at 1 cm near the hematoma, were taken as experimental groups; And the same tissues of 7 patients (＜12 h), which were far from the hemotoma on the operational way, were taken as control group. The pathologic and ultrastructral changes were observed.Results The tissues of the control group were almost normal while the damages of the tissues from the experimental groups were slight in ＜6 h groups, more severe after 6h and got to the maximum between 24 ～48 h , recovered gradually after 72 h, became similar to the 6 ～ 12 h group on 5 th day, got better on 8 th day and resembled the 6 h group.Conclusions The injury of the perihematoma occurred in early stage, reached the peak level between 24 and 48 hours after ICH; which was consistent to the clinical nervous functional deficits in the ICH patients.

Propriedades mecânicas de fios de NiTi e CuNiTi com efeito memória de forma utilizados em tratamentos ortodônticos / Mechanical properties of NiTi and CuNiTi wires used in orthodontic treatment

Objetivou-se nessa pesquisa comparar oito tipos de fios de NiTi superelásticos e termoativos, de seis empresas comerciais (GAC, TP, ORMCO, MASEL, MORELLI e UNITEK) àqueles com adição de cobre (CuNiTi 27 e 35OC, ORMCO), observando se as propriedades mecânicas dos dois últimos justificariam sua escolha clínica. Para tal foram realizados ensaios de tração e microscopia eletrônica de varredura. Os ensaios de tração foram realizados em máquina de ensaios mecânicos da marca EMIC, modelo DL10000, de 10 toneladas de capacidade, no Instituto Militar de Engenharia (IME). A composição química e a topografia superficial dos fios foram determinadas através da microscopia eletrônica de varredura em microscópio da marca JEOL, modelo JSM-5800 LV com sistema de microanálise EDS (energy dispersive spectroscopy). Os resultados mostraram que, de forma geral, os fios de NiTi termoativados apresentaram cargas mais suaves de desativação em relação aos superelásticos. Entre os fios que apresentaram as cargas biologicamente mais adequadas de desativação estão os termoativados da GAC e da UNITEK. Entre os fios de NiTi superelásticos, os de CuNiTi 27ºC da ORMCO foram os que apresentaram as cargas mais suaves de desativação, sendo semelhantes, estatisticamente (ANOVA), às apresentadas pelos fios de NiTi termoativados da UNITEK para a deformação de 4%. Quando comparados os fios de CuNiTi a 27 e a 35ºC, observou-se que os primeiros apresentaram forças de desativação de, aproximadamente, 1/3 das apresentadas pelos últimos, para a deformação de 4%. Quando analisada a microscopia eletrônica de varredura de superfície, os fios de NiTi superelásticos que apresentaram melhores acabamentos foram os da MASEL e MORELLI e os que apresentaram os piores acabamentos foram os de NiTi e CuNiTi 27ºC da ORMCO...

Leveling and aligning orthodontic wires must be able to generate light and continuous forces. Thus need to have high springback and flexibility. For this purpose it was suggested a variety of supereslatic and termoactivated Nickel-Titanium (NiTi) wires that may offer a load-deformation curve, in a constant plataform. Copper NiTi wires are presented as exhibiting better thermoactivating properties for optimum-forces system with better dental movement control. The aim of this study was to compare 8 NiTi superelastic and thermoactivated wires of six different brands (GAC, TP, ORMCO, MASEL, MORELLI and UNITEK) to Copper addicted wires (CuNiTi 270C and 350C, ORMCO) to verify if the mechanical properties of Copper NiTi would support it’s clinical use. Stress-strain tests were done in Engeneering Military Institute (IME-Brazil), through test machine (EMIC- DL 10000 model). Scanning electronic microscope with energy dispersive spectroscopy (JOEL, JSM-5800 LV model) was used to determine chemical composition and superficial topography of the wires. Results showed that, in general, thermoactivated NiTi wires exhibited lower deactivation loads when compared to NiTi superelastics. Among the thermoactivated, the GAC and UNITEK ones are the lighter ones. Among the superelastics, the Copper NiTi 270C (ORMCO) were the lighter ones, statistically similar (ANOVA) to thermoactivated NiTi from UNITEK, for 4% strain. Once Copper NiTi 270C showed deactivated loads 62% lower than Copper NiTi 350C , under 4% strain. As regard to Scanning Electronic Microscopy results for superelastic NiTi wires, better superficial burnishing were found for MASEL and MORELLI ones...

On the bone tissue reaction to implants with different surface treatment methods / 대한치과보철학회지

STATEMENT OF PROBLEM: Implant surface characteristics plays an important role in clinical success and many studies have been made for improvement of success by changing surface roughness. PURPOSE: Appropriate increase of surface roughness increases the activity of osteoblast and enhance contact and retention between bone and implant. MATERIAL AND METHOD: Machined, SLA and RBM surface implants, which are the most commonly used implants were implanted into the tibia of rabbits and after 1 week, 4 weeks, 8 weeks and 12 weeks there were histologic and histomorphometric analysis and study for bone gradient and change of Ca/P ratio using EDS(Energy Dispersive X-ray Spectroscope). RESULTS: Comparison of bone-implant contact showed no significant difference among each implant. In comparison of bone area rates, SLA showed higher value with significant difference at 1 week and 4 weeks, and SLA and RBM at 8 weeks than Machined implant (p<0.05). In analysis of bone constituents with EDS, titanium was specifically detected in new bones and the rates were constant by surface treatment method or period. In case of Ca/P ratio, according to surface treatment method, each group showed significant difference. Lots of old bone fragments produced during implantation remained on the rough surface of RBM implant surface and each group showed histological finding with active synthesis of collagen fibers until 12 weeks. In transmission electronic microscopic examination of sample slice after elapse of twelve weeks, tens nm of borderline (lamina limitans like dense line)was seen to contact the bone, on the interface between bone and implant. CONCLUSION: SLA and RBM implant with rough surface shows better histomorphometrical result and the trend of prolonged bone formation and maturation in comparison with Machined implant. In addition, implant with rough surface seems to be helpful in early stage bone formation due to remaining of old bone fragments produced in implantation. From the results above, it is considered to be better to use implant with rough surface in implantation.

Inhibitory Effect of Mitomycin C (MMC) on the Proliferation of Human Corneal Keratocyte

PURPOSE: To evaluate the anti-proliferative effect of mitomycin C (MMC) on human corneal keratocyte, and to investigate the cellular morphology of keratocyte according to the concentration and exposure time in vitro. METHODS: Human corneal keratocytes using endothelium-free explant method were exposed to 0.005%, 0.01%, and 0.05% concentration of MMC for 3, 5, and 10 minutes. MTT based colorimetric assay was performed to assess the inhibition of cellular proliferation, and cellular morphology was evaluated by inverted phase-contrast light microscope and electron microscope. RESULTS: Use of higher concentration MMC and prolongation of exposure time resulted in greater inhibitory effect on cellular proliferation. When exposed to 0.005% MMC for 3, 5 and 10 minutes, the survival rate of keratocyte was 100%, 95.7% and 74.0% respectively. At 0.01% MMC, the survival rate was 98.6%, 92.9%, and 66.9%. At 0.05% MMC, it was 74.0%, 73.4%, and 38.8%. Exposure to the highest concentration (0.05%) among the 3 preparations for 3 or 5 minutes showed significant inhibition of keratocyte proliferation (p<0.05), and when exposed for 10 minutes, all 3 preparations showed significant inhibition of keratocyte proliferation (p<0.05). Inverted phase-contrast light microscopy showed that human corneal keratocytes lost their adherence to the bottom of the dish and assumed round and swollen shape rather than spindle shape when exposed to higher concentration of MMC for a prolonged time. The damaged keratocytes showed the degenerative changes like cellular membrane disruption, disappearance of microvilli, enlargement of rough surfaced endoplasmic reticulum and mitochondria, and vacuole formation by electronic microscope. CONCLUSIONS: When MMC is applied to inhibit the proliferation of keratocytes involved in corneal wound healing, it seems to be a valuable application at least 0.05% concentration for 3 minutes. Further studies should be followed for the biological effect of MMC including drug toxicity associated with human corneal tissue in vivo.

Scanning electronic microscope observation of bone marrow stem cells transfected by IGF-1 gene and cultured onto ostrich true bone ceramic / 实用口腔医学杂志

Objective:To evaluate the biocompatibility of insulin-like growth factor I (IGF-1) gene transfected bone marrow stem cells (MSCs) with ostrich true bone ceramic (OTBC). Methods:Rat MSCs were transfected with IGF-1 gene, and positive clones were selected by G418. The expression of IGF-1 protein in the MSCs was detected by immunocytochemical technique. The IGF-1 transfected MSCs were cultured with OTBC and the morphology of the cells was observed by scanning electronic microscope(SEM) at different time point. Results:Immunohistochemical staining suggested that the IGF-1 protein was expressed in the IGF-1 transfected MSCs. The cells adhered to OTBC and stretched well after 24 h of culture. The IGF-1 transfected MSCs proliferated on the surface of OTBC with culture time.Conclusion:The OTBC has a good biocompatibility with IGF-1 transfected MSCs.

Study on Enzymology and Morphology Effects of Extractions of Cyanobacteria on Primary Cultured Hepatocyte / 环境与健康杂志

Objective To make a further study on the character and mechanism of hepatotoxic effect of microcystin(MC),which stands for the extractions of cyanobacteria Methods The enzymology and morphology effects of different concentrations of 0.1,1,10 ?g/ml extractions of cyanobacteria on primary cultured hepatocyte were observed Results It was shown that the concentrations of LDH and AST increased in the culture medium after exposure to MC at concentrations of 0.1 ,1 and 10 ?g/ml No significant changes of concentrations of AKP, GGT, ALT and GSH were observed in the culture media of tested groups.An active proliferation of cultured hepatocytes with apopotosis or necrosis were observed in the center of the proliferation foci in the treated groups.Characterisitic morphological alterations such as irregular shape,cytoplasmic cavity,plasma membrane blebs and protrusions were viewed in scanning electronic microscope as well as in cultured cell. Conclusion The extractions of cyanobacteria could promote the proliferation of hepatocyte and might influence the physiological and biochemical function and the integrity of hepatocyte

GROWTH AND MORPHOLOGY OF LEPTOSPIRILLUM FERROOXIDANS ON SOLID MEDIUM / 微生物学通报

Single clones of Leptospirillum ferrooxidans were obtained on bilayer solid medium plate by incorporating Het-erotroph Acidiphilium SJH into the underlayer broth medium. The morphologies of the bacteria were investigated using electronic microscope.

MORPHOLOGICAL OBSERVATION IN VITRO MODEL OF BLOOD-TUMOR BARRIER OF GLIOMA / 解剖学报

Objective To study the morphological characteristics of blood-tumor barrier(BTB)model of glioma in vitro. Methods After C 6 glioma cells/endothelia ECV 304 co-cultured mixed or in Transwell or on both sides of membrane of Transwell,the morphological characters of fenestra of endothelial cells,the junction between ECV 304 cells,the interface between C 6 cells and ECV 304 cells,and perivascular-end-feet of C 6 cells were observed under transmission electron microscope(TEM)and scanning electron microscope(SEM),and compared to BTB in 4 cases with human brain glioma. Results ECV 304 cells grown to confluence were not fenestrated,but with fomation of tight junction between ECV 304 cells after co-cultured with C 6 cells mixedly,in Transwell or on both sides of membrane of Transwell;It was not found that pseudopodia from C 6 cells as co-cultured in Transwell reaching into pore of Transwell;C 6 cells co-cultured on both sides of membrane of Transwell often sticked out to the ECV 304 cells,but with no pseudopodia from C 6 cells surrounded ECV 304 cells of penetrated the endothelia clefts.Perivascular-end-feet of C 6 cells were not integrant.These characters were similar to BTB in human brain glioma.Conclusion C 6 glioma cells/endothelia cell ECV 304 co-cultures on both sides of membrane of Transwell may simulate the morphological characters of BTB in vivo in some degree.;

EFFECTS OF SCHWANN CELLS ON SURVIVAL AND DIFFERENTIATION OF NEURAL STEM CELLS in vitro / 解剖学报

Objective Whether Schwann cells could promote the survival and differentiation of neural stem cells was explored in vitro. Methods Neural stem cells were dissociated and cloned from the hippocampal tissue of newborn rats.Schwann cells were also dissociated and purified simultaneously from the sciatic nerves and brachial plexus nerves of newborn rats.Then Schwann cells and neural stem cells were Co cultured.The expression of nestin of the neural stem cells and the expression of neurofilament(NF) or glial fibrillary acidic protein(GFAP)of the differentiated cells were detected by immunohistochemistry.The morphological changes of neural stem cells were examined with scanning electronic microscope. Results Compared with control group,the number of surviving neural stem cells and differentiated neuron like cells was significantly increased in Co cultured (Schwann cells add neural stem cells)groups.The primary processes of neuron like cells in Co cultured groups were obviously longer than that in control groups.The irregular convex or concave of the body of neural stem cells became plain and smooth in Co cultured group.Co cultured Schwann cells and neural stem cells have grown to touch together in following manner:1.Body touch body;2.Body touch process;3.Process touch process.Conclusion\ Schwann cells can promote the survival and differentiation of co cultured neural stem cells in vitro.