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1.
Int. j. morphol ; 40(4): 966-972, 2022. ilus, tab
Article in English | LILACS | ID: biblio-1405250

ABSTRACT

SUMMARY: Plastination is an anatomical preparate preparation technique characterized by the replacement of tissue fluids with a reactive polymer. Although more challenging and economically costly than many anatomical methods, this method is desirable because of the fact that specimens created in this method are highly similar to the natural appearance of the intended objects, and they are durable and harmless end products for human health. Our main goal was to completely leave out formaldehyde and similar carcinogenic chemicals used in a method like plastination and to allow production of formaldehyde-free plastinates to be used in anatomy training and examinations in our country. To that end, we compared nose and tongue of 10 large ruminants by subjecting them to plastination, 5 of them with formaldehyde and 5 of them without formaldehyde, and aimed to leave formaldehyde out by taking into account the difference between them. Silicone plastination is the most commonly-used and best-known technique among the plastination techniques because specimens created using this technique look aesthetically impressive. Silicone plastination consists mainly of 5 phases. First of all, we obtained the anatomical situs we wanted and made specimens ready by dissecting some of them after fixation and some of them without fixation. Then, after the implementation of a dehydration phase in acetone baths at -25 °C, a forced impregnation phase was implemented by using a mixture of S10-S3 chemical under negative pressure. In the final phase, the curing and hardening phase, the plastination process was completed by giving the specimens their final shape with the use of the S6 solution. As a result, no significant difference was observed between silicone plastination with and without formaldehyde.


RESUMEN: La plastinación es una técnica de preparados anatómicos caracterizada por la sustitución de fluidos tisulares por un polímero reactivo. A pesar de ser económicamente más costoso que muchas métodos anatómicos, este técnica es deseable debido a que las muestras creadas son muy similares a la apariencia natural de los objetos previstos y son productos finales duraderos e inofensivos para la salud humana. Nuestro objetivo principal fue dejar completamente de lado el formaldehído y las sustancias químicas cancerígenas similares utilizadas en un método como la plastinación y permitir la producción de plastinados libres de formaldehído para su uso en la formación y los exámenes de anatomía en nuestro país. Con ese fin, comparamos la nariz y la lengua de 10 rumiantes mayores sometiéndolos a plastinación, 5 de ellos con formaldehído y 5 de ellos sin formaldehído, y buscamos eliminar el formaldehído considerando la diferencia entre ellos. La plastinación con silicona es la técnica más utilizada y más conocida entre las técnicas de plastinación porque los especímenes creados con ella se ven estéticamente impresionantes. La plastinación con silicona consta principalmente de 5 fases. En primer lugar, obtuvimos el situs anatómico que queríamos y preparamos los especímenes diseccionando algunos de ellos después de la fijación y otros sin fijación. Luego, de la implementación de una fase de deshidratación en baños de acetona a -25 °C, se implementó una fase de impregnación forzada utilizando una mezcla del químico S10-S3 a presión negativa. En la fase final, la fase de curado y endurecimiento, se completó el proceso de plastinación dando a los especímenes su forma definitiva con el uso de la solución S6. Como resultado, no se observaron diferencias significativas entre la plastinación con silicona con y sin formaldehído.


Subject(s)
Animals , Silicones/chemistry , Ruminants/anatomy & histology , Formaldehyde/chemistry , Plastination/methods , Acetone
2.
Int. j. morphol ; 38(5): 1371-1375, oct. 2020. tab, graf
Article in English | LILACS | ID: biblio-1134450

ABSTRACT

SUMMARY: Fixation is a crucial step in processing of tissue specimen for preservation of cellular architecture and composition of cells. Alcohol-based fixatives are considered some of the most promising alternatives to formalin. We evaluated the performance of alcohol-based fixatives (EthMeth and methacarn) and formalin as a comparator fixative in the research laboratory. Following 24 hours of fixation, tissue morphology and cellular details of the liver, spleen and brain (cerebral cortex) were evaluated. Morphological characteristics were evaluated by gross observations and analyzing cellular details, tissue architecture and overall staining characteristics (Hematoxylin and Eosin). EthMeth and methacarn fixation gave generally comparable and satisfactory results on the tissue morphology and subsequent identification of tissue characteristics. Particularly, tissues were well preserved and all nuclear as well as cytoplasmic details were clearly visible. However, formalin fixed tissues showed some peculiarity such as improper fixation, mild shrinkage, and alterations of tissue components. These results confirm that alcohol-based fixation is the superior alternative to formalin for preservation of tissue morphology. However, it is required to standardize the formalin-free methods and harmonize diagnosis in the laboratory worldwide.


RESUMEN: La fijación es un paso crucial en el procesamiento de muestras de tejido para preservar la arquitectura celular y la composición de las células. Los fijadores a base de alcohol se consideran algunas de las alternativas más prometedoras a la formalina. Evaluamos el rendimiento de los fijadores a base de alcohol (EthMeth y metacarn) y formalina como fijador comparativo en el laboratorio de investigación. Después de 24 horas de fijación, se observó la morfología del tejido y los detalles celulares del hígado, bazo y corteza cerebral. Se evaluaron las características morfológicas mediante observaciones generales y analizando detalles celulares, arquitectura de tejidos y características generales de tinción (hematoxilina y eosina). La fijación de EthMeth y metacarn dio resultados generalmente comparables y satisfactorios en la morfología del tejido y la posterior identificación de las características del mismo. Particularmente, los tejidos estaban bien conservados y todos los detalles nucleares y citoplasmáticos eran claramente visibles. Sin embargo, los tejidos fijados con formalina mostraron cierta peculiaridad, tal como una fijación inadecuada, la contracción leve y alteraciones de los componentes del tejido. Estos resultados confirman que la fijación a base de alcohol es la mejor alternativa a la formalina, para preservar la morfología del tejido. Sin embargo, es necesario estandarizar los métodos sin formalina y armonizar el diagnóstico en los laboratorios.


Subject(s)
Tissue Fixation/methods , Alcohols/chemistry , Fixatives , Formaldehyde/chemistry , Chloroform/chemistry , Acetic Acid/chemistry , Methanol/chemistry
3.
Int. j. morphol ; 37(2): 533-540, June 2019. tab
Article in Spanish | LILACS | ID: biblio-1002255

ABSTRACT

Desde la antigüedad se han desarrollado técnicas para el estudio del cerebro con fines didácticos o neuroquirúrgicos. Hacia 1934 Josef Klingler desarrolla una técnica de preparación de hemisferios cerebrales que basada en la fijación con formalina y el congelamiento para aislar los tractos cerebrales. El objetivo de la presente artículo ha sido analizar los métodos de preparación utilizados para la disección de tractos en cerebros humanos y de animales. Se realizó una revisión de la literatura en las bases de datos Web of Science, Scopus, Pubmed, Medline y Scielo, utilizando como descriptores: Disección, Cerebro, Tracto, con el operador booleano "AND" entre ellos, en los idiomas inglés y español, hasta junio de 2018. Fueron seleccionados 26 documentos, para el análisis se determinaron las variables: espécimen, número de hemisferios cerebrales, concentración de formalina, tiempo de fijación, temperatura, tiempo de congelamiento y tractos identificados. En la literatura seleccionada, un total de 410 hemisferios cerebrales fueron analizados, 372 de humanos y 38 de animales; 330 fueron conservados en formalina al 10 %, 20 en formalina al 5 % y el resto en otras concentraciones. El tiempo de fijación fue variable entre 10 y 180 días, así como la temperatura y tiempo de congelación (-10 ºC y -20 ºC, entre 8 y 30 días). En todos los casos se reportó que, en su totalidad o parcialmente, los fascículos cerebrales de asociación fueron aislados. En la preparación de hemisferios cerebrales para disección de tractos, Ludwig & Klingler (1956) recomiendan que en la fijación de los especímenes se utilice formalina al 5 %, sin embargo, el 80 % de los hemisferios utilizados fueron fijados en formalina al 10%, y en esta concentración, el tiempo de fijación, temperatura y tiempo de congelación fue variable, lográndose, en todos los casos analizados, la disección parcial o total de los tractos.


Since ancient times, techniques for the study of the brain have been developed for didactic or neurosurgical purposes. By 1934, Josef Klingler developed a cerebral hemisphere preparation technique based on formalin fixation and freezing to isolate the cerebral tracts. The aim of this article was to analyze the preparation methods used for tracts dissection in human and animal brains. A review of the literature using Web of Science, Scopus, Pubmed, Medline and Scielo databases, with the following descriptors: Dissection, Brain, Tract, with the boolean operator "AND" among them, also in spanish, until June 2018. Twenty-six documents were selected, and we analized the following variables: specimen, number of cerebral hemispheres, formalin concentration, fixing time, temperature, freezing time and tracts. In the selected literature, a total of 410 cerebral hemispheres were analyzed, 372 from humans and 38 from animals; 330 were preserved in 10 % formalin, 20 in 5 % formalin and the rest in other concentrations. The fixation time was variable between 10 and 180 days, as well as the temperature and freezing time (-10 ºC and -20 ºC, between 8 and 30 days). In all cases it was reported that, in whole or in part, the cerebral fascicles of association were isolated. In the preparation of cerebral hemispheres for dissection of tracts, Klingler recommend that 5 % formalin for the fixation of specimens; however, 80 % of the hemispheres used were fixed in 10 % formalin, and in this concentration, the time of fixation, temperature and time of freezing was variable, achieving, in all the cases analyzed, the partial or total dissection of the tracts.


Subject(s)
Humans , Animals , Histocytological Preparation Techniques/methods , Dissection/methods , Cerebrum/anatomy & histology , Time Factors , Tissue Preservation/methods , Fixatives , Formaldehyde/chemistry , Freezing
4.
Arq. bras. oftalmol ; 82(1): 56-61, Jan.-Feb. 2019. tab, graf
Article in English | LILACS | ID: biblio-973867

ABSTRACT

ABSTRACT Purpose: The porcine eye is frequently used as a research model. This paper analyzes the effect of different storage methods on the transparency of pig crystalline lens. Methods: A spectral transmission curve (from 220 to 780 nm) for the crystalline lens was determined experimentally after storage in different conditions: saline solution, formalin, castor oil, and freezing at -80°C. The total transmission in the visible spectrum, which was used as an index of transparency, was calculated from these curves. For comparative purposes, fresh lenses were evaluated and used as controls. Results: Storing the porcine crystalline lens in saline solution or castor oil resulted in a transparency loss of approximately 10% after 24 h and storage in formalin resulted in a loss of nearly 30%. Storage by freezing at -80°C for 4 weeks maintained the transparency of the crystalline lens; the spectral transmission measured immediately after defrosting at room temperature coincided exactly with that of the freshly extracted lens. Conclusions: The transparency of porcine crystalline lens is affected by the storage method. The visible spectrum is the most affected, evidenced by the effect on the transparency and consequently the amount of light transmitted. The results show that freezing at -80°C maintains the transpa rency of the crystalline lens for at least 4 weeks.


RESUMO Objetivos: Olho de porco é frequentemente usa do como modelos de pesquisa. Este estudo analisa o efeito de di ferentes métodos de armazenamento na preservação da transparência do cristalino de porco. Métodos: Uma curva de transmissão espectral (de 220 até 780 nm) para o cristalino foi experimentalmente determinada após armazenamento em diferentes condições: solução salina, formol, óleo de mamona e congelamento a -80°C. Transmissão total do espectro visível, que foi usada como um índice de transparência foi calculada a partir dessas curvas. Para fins comparativos, lentes frescas foram avaliadas e usadas como controles. Resultados: O armazenamento do cristalino suíno em solução salina ou óleo de mamona resultou uma perda de transparência de aproximadamente 10% após 24 h e o armazenamento em formol resultou uma perda de quase 30%. O armazenamento por congelamento a -80°C durante 4 semanas manteve a transparência do cristalino; a transmissão espectral medida imediatamente após o descongelamen to à temperatura ambiente coincidiu exatamente com a da lente extraída recentemente. Conclusão: A transparência do cristalino suíno é afetada pelo método de armazenamento. O espectro visível é o mais afetado, evidenciado pelo efeito sobre a transparência e consequentemente a quantidade de luz transmitida. Os resultados mostram que o congelamento a -80°C mantém a transparência do cristalino suíno por pelo menos 4 semanas.


Subject(s)
Animals , Organ Preservation/methods , Lens, Crystalline/anatomy & histology , Reference Values , Spectrophotometry/instrumentation , Spectrophotometry/methods , Swine , Time Factors , Ultraviolet Rays , Castor Oil/chemistry , Reproducibility of Results , Models, Animal , Formaldehyde/chemistry , Freezing , Lens, Crystalline/physiology , Lens, Crystalline/diagnostic imaging , Light
5.
Int. j. morphol ; 32(2): 571-574, jun. 2014. ilus
Article in Spanish | LILACS | ID: lil-714311

ABSTRACT

El material anatómico del sistema nervioso central es cada vez más difícil de obtener. A pesar de estar fijado, es muy lábil y al ser expuesto a diversas condiciones ambientales durante las actividades docentes, se va deteriorando, resecándose, adquiriendo una consistencia rígida y un aspecto oscuro que finalmente hace difícil el reconocimiento de estructuras. De la misma manera, cuando obtenemos una pieza de un cadáver con larga data de fallecido, nos podemos encontrar con un encéfalo que por lo reseco de su estado, no presta mayor utilidad. El objetivo de esta técnica es recuperar estas muestras, para que puedan ser utilizadas convenientemente en el estudio anatómico. Se usaron distintos segmentos de encéfalo, incluidos algunos contaminados por hongos y otros obtenidos de cadáveres antiguos. Los materiales utilizados fueron, agua oxigenada, agua destilada, formalina y recipientes plásticos. Se comienza limpiando manualmente las muestras de restos de polvo y cuerpos extraños que se encuentren en su superficie. Se continúa con baños en agua oxigenada, intercalando con rehidrataciones en agua destilada, hasta obtener el color y textura deseados que permitan distinguir macroscópicamente estructuras de la muestra. Posteriormente se refuerza la fijación sumergiéndolas en formalina, para luego conservarlas en forma indefinida, humedecidas con este fijador en bolsas plásticas selladas y dentro de caja plásticas tapadas. Otras muestras fueron plastinadas posteriormente. Al finalizar la técnica la mayoría de las muestras se recuperaron notoriamente, permitiendo reconocer estructuras que por su deterioro era imposible apreciar con anterioridad. En conclusión, este método permite recuperar y darle uso a muestras que estaban prácticamente desechadas.


The anatomical material of the central nervous system is increasingly difficult to obtain. Despite being fixed, is very labile and when exposed to various environmental conditions during teaching, becomes deteriorated and drier, acquiring a rigid consistency and darker appearance, which eventually makes it difficult to recognize structures. At the same time, when we obtain a piece of a long-standing cadaver, we can come across a brain so dry, that its state does not provide any use. The aim of this technique was to recover these samples so they can be conveniently used for anatomical studies. We used various brain segments, including some contaminated with fungi and others obtained from old cadavers. The materials used were, hydrogen peroxide, distilled water, formaldehyde and plastic containers. We begin by manually cleaning the samples from any dust and foreign bodies that could be found on their surface. Then, continues with hydrogen peroxide baths, interspersing with re-hydration in distilled water, until we obtain the desired color and texture that allows us to macroscopically distinguish the structures. Subsequently, we reinforce fixation by immersing in formaldehyde. Subsequently, we keep them moistened with this fixation agent in sealed plastic bags indefinitely, inside covered plastic boxes. Other samples were subsequently plastinated. After we applied this technique, most of the samples were noticeably recovered, allowing recognition of structures that, previously because of their deterioration, were impossible to see. In conclusion, this method allows the recovering and gives use to samples that had been previously discarded.


Subject(s)
Humans , Tissue Preservation/methods , Central Nervous System , Anatomy/methods , Brain , Cadaver , Distilled Water , Formaldehyde/chemistry , Hydrogen Peroxide/chemistry
7.
Sudan Journal of Medical Sciences. 2013; 8 (3): 147-150
in English | IMEMR | ID: emr-139689

ABSTRACT

Fixation is complex series of chemical events which differs for the different group of chemical substances found in tissues. Some chemical reactions, including those involved in fixation occur more rabidly at higher temperature. To assess the effect of varying fixatives' temperature on the quality of subsequent histochemical staining. Rabbit samples were collected including tongue tissue to demonstrate collagen fibers using Van Geison's stain, and liver tissue to demonstrate cell morphology using Erlich's haematoxylin. Specimens were divided into pieces; each sample was fixed in the following fixatives: formal saline, neutral buffer formalin [NBF], Carnoy's and Bouin's fixative in different temperatures as follow 4°C, 25°C, 37°C and 60°C. There after, tissues were embedded in paraffin and cut sections into 5 micron and stained with Ehrlich's hematoxylin and Van Gieson histochemical stains. For Erlich's heamtoxylin, formal saline gave the best result for tissues fixed at 60°C; NBF gave the best results at 37°C and 60°C. For Van Geison stain, formal saline and NBF the best results obtained at 37°C. The study concluded that using 10% NBF, 10% Formal saline, Carnoy's and Bouin's fixatives applying different temperatures include 4°C, 25°C, 37°C and 60°C affect the subsequent histochemical staining of Ehrlich's hematoxylin, and Van Gieson


Subject(s)
Animals, Laboratory , Histocytochemistry , Tissue Fixation/methods , Temperature , Coloring Agents , Formaldehyde/chemistry , Rabbits
8.
Journal of Advanced Research. 2013; 4 (2): 115-121
in English | IMEMR | ID: emr-168512

ABSTRACT

The reaction of 6-amino-1,3-dimethylpyrimidine-2,4[1H,3H]-dione [1] as a binucleophile with primary aromatic or heterocyclic amines and formaldehyde or aromatic [heterocyclic] aldehydes in a molar ratio [1:1:2] gave the pyrimido[4,5-d]pyrimidin-2,4-dione ring systems 2-5. Treatment of 1 with diamines and formalin in molar ratio [2:1:4] gave the bis-pyrimido[4,5-d]pyrimidin- 2,4-diones 6-8. Furthermore, substituted pyrimido[4,5-d]pyrimidin-2,4-diones with uracil derivative 11 or spiro indole 16 were synthesized. Synthesis of pyrimido[4,5-d]pyrimidin-2,4-diones with different substitution at C-5 and C-7 was achieved to give 13 and 18, respectively


Subject(s)
Digitonin/chemistry , Semicarbazides/chemistry , Imines/chemistry , Diamines , Formaldehyde/chemistry
9.
Pakistan Journal of Pharmaceutical Sciences. 2013; 26 (5): 921-928
in English | IMEMR | ID: emr-138410

ABSTRACT

A simple, sensitive, selective and cost effective spectrofluorimetric method has been established for the quantification of sulpiride after their complete alkaline hydrolysis. The method is based on the condensation of the primary amino group of alkaline hydrolytic product of sulpiride with acetyl acetone and formaldehyde in acidic medium [0.25 M HCl] to form a fluorescent product. The reaction product formed shows maximum fluorescence intensity at 483 nm after excitation at 431 nm. The different reaction conditions influencing the condensation reaction were carefully optimized and a linear range of 0.1-3.5 micro g mL[-1] with good correlation coefficient between florescent intensity and concentration of sulpiride was found at optimum parameters. The LOD and LOQ were found to be 11 and 39 ng mL[-1] respectively. The proposed method was successfully used for the quantification of sulpiride in bulk powder and commercial formulations. The effect of common pharmaceutical excipients and co-administered drug was also studied and no interferences were observed. The validity of the method was tested by analyzing sulpiride in bulk powder, and pharmaceutical formulations through recovery studies. Recoveries [%] were obtained from 98.62 to 100.24% for bulk powder, and 97.09 to 100.57% for commercial formulations. The results were validated statistically with those obtained by reference literature high performance liquid chromatographic method


Subject(s)
Spectrometry, Fluorescence/standards , Technology, Pharmaceutical/methods , Temperature , Pentanones/chemistry , Powders , Reference Standards , Reproducibility of Results , Formaldehyde/chemistry , Hydrogen-Ion Concentration
10.
J. appl. oral sci ; 20(4): 455-461, July-Aug. 2012. tab
Article in English | LILACS | ID: lil-650623

ABSTRACT

OBJECTIVE: To assess the setting time (ST), flow (FL), radiopacity (RD), solubility (SB) and dimensional change following setting (DC) of different sealers (AH Plus®, Polifil, Apexit Plus®, Sealapex®, Endométhasone® and Endofill®) according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 57. MATERIAL AND METHODS: Five samples of each material were used for each test. For ST, cast rings were filled with sealers and tested with a Gilmore needle. For FL, the sealer was placed on a glass plate. After 180 s, another plate with 20 g and a load of 100 g were applied on the material, and the diameters of the discs formed were measured. In RD, circular molds were filled with the sealers, radiographed and analyzed using Digora software. For SB, circular molds were filled with the sealers, a nylon thread was placed inside the material and another glass plate was positioned on the set, pressed and stored at 37°C. Samples were weighed, placed in water, dried and reweighed. The water used for SB was analyzed by atomic absorption spectrometry. For DC, circular molds were filled with the sealers, covered by glass plates and stored at 37°C. Samples were measured and stored in water for 30 days. After this period, they were dryed and measured again. RESULTS: Regarding ST, AH Plus®, Apexit® and Endofil® sealers are in accordance with ANSI/ADA standards. Endométhasone's manufacturer did not mention the ST; Polifil is an experimental sealer and Sealapex® did not set. Considering RD, SB and DC, all sealers were in accordance with ANSI/ADA. The spectrometric analysis showed that a significant amount of K+ and Zn2+ ions was released from Apexit Plus® and Endofill®, respectively. CONCLUSION: Except for DC, all other physicochemical properties of the tested sealers conformed to ANSI/ADA requirements.


Subject(s)
Humans , Root Canal Filling Materials/chemistry , American Dental Association , Analysis of Variance , Calcium Hydroxide/chemistry , Drug Combinations , Dexamethasone/chemistry , Epoxy Resins/chemistry , Formaldehyde/chemistry , Hydrocortisone/chemistry , Materials Testing , Root Canal Filling Materials/standards , Solubility , Statistics, Nonparametric , Surface Properties , Salicylates/chemistry , Time Factors , Thymol/analogs & derivatives , Thymol/chemistry , United States
11.
Journal of Forensic Medicine ; (6): 347-350, 2012.
Article in Chinese | WPRIM | ID: wpr-983759

ABSTRACT

OBJECTIVE@#To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis.@*METHODS@#The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid : 0.1% formic acid-acetonitrile (75:25). Electrospray ionization (ESI) source was utilized and operated in positive ion mode. Multiple reactions monitoring (MRM) mode was applied. External standard method was applied for quantitation.@*RESULTS@#The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002-2.0 microg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection (LOD) of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%.@*CONCLUSION@#Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.


Subject(s)
Chromatography, Liquid/methods , Forensic Toxicology , Formaldehyde/chemistry , Formates , Kidney/metabolism , Limit of Detection , Liver/metabolism , Mass Spectrometry , Molecular Structure , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization/methods , Strychnine/chemistry , Tandem Mass Spectrometry , Tissue Distribution
12.
Int. j. morphol ; 29(2): 656-660, June 2011. ilus
Article in English | LILACS | ID: lil-597508

ABSTRACT

Glutaraldehyde is the fixative most commonly used in electron microscope studies of biological tissues, however it is often necessary to use samples which were not fixed in this fixative, even with the usual uncertainty of the results that may be obtained. The fixation is the more delicate step of the sample processing. Therefore in this work, the quality of preservation of haemal nodes fixed with two classic aldehyde fixatives: formaldehyde and glutaraldehyde we have compared under the scanning electron microscope. Our results showed that both fixatives were successful in preserving the morphology of haemal nodes components; however glutaraldehyde conferred satisfactory results mainly in the preservation of parenchymal cells, whereas formaldehyde was better for preservation of stromal fibres.


El glutaraldehido es el fijador que se utiliza con más frecuencia en estudios en los tejidos biológicos a través microscopía electrónica. Sin embargo, a menudo es necesario utilizar muestras que no han sido fijadas con este fijador, aún con la incertidumbre de los resultados que se puedan obtener. La fijación es el paso más importante en el procesamiento de los tejidos. Por lo anterior, hemos efectuado este estudio comparando la calidad de conservación de nodos linfáticos hemales fijados con formaldehido y glutaraldehido. Los resultados muestran que ambos fijadores conservaron adecuadamente la morfología de los componentes de los nodos linfáticos hemales, sin embargo, el glutaraldehido conservó en mejores condiciones, principalmente, las células del parénquima, pero el formaldehido conservó mejor las fibras del estroma en nodos linfáticos.


Subject(s)
Animals , Tissue Fixation/methods , Glutaral/chemistry , Formaldehyde/chemistry , Lymph Nodes/ultrastructure , Organ Preservation/methods , Sheep , Microscopy, Electron, Scanning , Aldehydes/chemistry
13.
Braz. dent. j ; 21(2): 142-147, 2010. tab, ilus
Article in English | LILACS | ID: lil-551935

ABSTRACT

The aim of this ex vivo was to investigate if two radiopaque root canal sealers with different formulations would influence the radiographic perception of root canal fillings. The root canals of 48 extracted maxillary canines were prepared and randomly assigned to 3 groups of 16 specimens each. In each group, the root canals were filled by lateral condensation of gutta-percha and one of the tested sealers: Endométhasone, Sealer 26, or a non-radiopaque sealer. A through-and-through void was simulated in half of the specimens from each group (n=8). The buccolingual radiographic images obtained were randomly interpreted for voids existence by a radiologist and an endodontist. The differences in sensitivity and specificity between groups and examiners were compared using, respectively, Fisher's Exact and McNemar tests at 5 percent significance level. Both radiopaque sealers caused a significant decrease in sensitivity at the coronal part of fillings. The use of Endométhasone increased specificity values for both coronal and apical portions of the root canal fillings. In conclusion, the tested sealers influenced the radiographic perceptions of laterally condensed root canal fillings in a different way.


O propósito deste estudo ex vivo foi investigar se dois cimentos obturadores de fórmulas diferentes influenciariam a percepção radiográfica de obturações de canais radiculares. Os canais radiculares de 48 caninos superiores extraídos foram preparados e divididos em 3 grupos. Em cada grupo os canais foram preenchidos através da condensação lateral da guta-percha e de um dos cimentos testados (Endométhasone, Sealer 26 e cimento não-radiopaco), e um defeito de ponta a ponta foi simulado em metade dos espécimes de cada grupo (n=8). As imagens radiográficas vestíbulo-linguais obtidas foram aleatoriamente interpretadas quanto à existência de defeitos por um radiologista e um endodontista. As diferenças em sensibilidade e especificidade entre os grupos e examinadores foram comparadas respectivamente usando-se os testes Exato de Fisher e McNemar ajustados ao nível de significância de 5 por cento. Ambos os cimentos radiopacos ocasionaram uma redução significativa da sensibilidade na parte cervical das obturações. O uso do Endométhasone aumentou os valores de especificidade para as porções cervical e apical das obturações dos canais radiculares. Concluiu-se que os cimentos testados influenciaram de maneira distinta a percepção radiográfica de obturações endodônticas executadas com condensação lateral.


Subject(s)
Humans , Dental Marginal Adaptation/standards , Dental Pulp Cavity , Radiography, Dental/standards , Root Canal Filling Materials/chemistry , Root Canal Obturation/standards , Bismuth/chemistry , Cuspid , Calcium Hydroxide/chemistry , Drug Combinations , Dexamethasone/chemistry , Formaldehyde/chemistry , Hydrocortisone/chemistry , Maxilla , Observer Variation , Reproducibility of Results , Sensitivity and Specificity , Statistics, Nonparametric , Thymol/analogs & derivatives , Thymol/chemistry
14.
Egyptian Journal of Chemistry. 2009; 52 (3): 381-393
in English | IMEMR | ID: emr-135690

ABSTRACT

Nine carbon xerogels were synthesized from resorcinol formaldehyde resin [RF], under increasing resorcinol/catalyst, Na2CO3, [R/C] molar ratios [50, 500. 1000], followed by pyrolysis at temperatures of 500, 600 and 700°C, under no external flow of gases. One organic xerogel was included for the sake of comparison. Drying of the RF hydrogels was carried out by the conventional evaporation technique in static air to get the RF xerogel Obtained carbons were characterized by CHO content, TEM, and N2/77K adsorption. Porosity characteristics were calculated by applying the well established alpha s plots to get various textural parameters. It was found that an increase in surface area, and pore volume was associated with corresponding rise in the R/C molar ratios. Most porosity, mainly, existed within the micropore size range, particularly for xerogels developed at 600 or 700°C, Thus. well-developed porous activated carbons could be obtained from an organic RF-xerogel by pyrolysis at 700°C and at high R/C-precursor ratios [500 and 1000]. The described simple conditions of preparation might encourage the pilot-scale production of porous carbon xerogels, suitable as adsorbents in liquid-phase environmental treatment processes


Subject(s)
Carbon/chemistry , Formaldehyde/chemistry
15.
Journal of Forensic Medicine ; (6): 337-344, 2009.
Article in Chinese | WPRIM | ID: wpr-983497

ABSTRACT

OBJECTIVE@#To assess the influential factors of STR genotyping in 10% unbuffered formalin fixed paraffin embedded samples.@*METHODS@#Eight kinds of autopsy samples including heart, brain, liver, spleen, kidney, lung, stomach and intestine tissue from 2 corpse were fixed with 10% unbuffered formalin and embedded with paraffin according to the routine procedure from which the DNA were extracted with three different methods (QIAGEN, IQ and Chelex). STR profile were analyzed with AmpFlSTR Identifiler Kit and capillary electrophoresis on genetic analyzer 3100-Avant. STR profiles of 56 archival paraffin embedded samples from 15 cases were also analyzed with methods as mentioned. These archival samples, including heart, liver, lung and intestine tissue, had been preserved for 1 to 5 years in ambient temperature. Effectiveness of STR genotyping was assessed with the recalling ration of the 15 STR loci composing of the Identifiler Kit.@*RESULTS@#Significant difference of the recalling ration was statistically revealed among the different types of paraffin embedded sample with same preserving period. Moreover, the STR recalling ration was continuously lowering with the prolongation of preserving period in all of the samples. The linear relationship between the STR recalling ratio and the preserving period was showed in lung and heart sample. The STR recalling ration in lung sample was higher than that in the other types of paraffin embedded sample.@*CONCLUSION@#Preserving period, tissue type, extracting method of DNA and the PCR template concentration were the most important influential factors for successfully STR genotyping paraffin embedded samples, which fixed with unbuffered formalin for the same time.


Subject(s)
Humans , DNA/isolation & purification , DNA Fingerprinting/methods , Forensic Genetics/methods , Formaldehyde/chemistry , Liver , Lung , Myocardium , Paraffin Embedding , Polymerase Chain Reaction , Specimen Handling/methods , Tandem Repeat Sequences , Time Factors , Tissue Fixation
16.
Braz. oral res ; 22(4): 352-357, 2008. ilus, tab
Article in English | LILACS | ID: lil-502190

ABSTRACT

This study evaluated the influence of the method and period of storage on the adhesive bond strength of indirect composite resin to bovine dentin. Ninety bovine incisors were stored in three different solutions: 0.2 percent thymol, 10 percent formalin, and 0.2 percent sodium azide, during 3 periods of storage: 7 days, 30 days and 6 months, resulting in 9 groups (n = 10). The roots were cut off and the buccal surface was ground with #600-grit silicon carbide paper. The surface was conditioned with 37 percent phosphoric acid for 15 s and a composite resin restoration (TPH Spectrum) was fixed using a one-bottle adhesive system (Adper Single Bond) and a dual-cured resinous cement (Rely X ARC) under a load of 500 g for 5 minutes. The samples were serially cut perpendicular to the bonded interface to obtain slices of 1.2 mm in thickness. Each slab was trimmed with a cylindrical diamond bur resulting in an hourglass shape with a cross-sectional area of approximately 1 mm². The microtensile bond strength (μTBS) testing was performed in a testing machine (EMIC 2000 DL) at a 0.5 mm/minute crosshead-speed until failure. After fracture, the specimens were examined under SEM to analyze the mode of fracture. μTBS Means were expressed in MPa and the data were analyzed by two-way ANOVA (3X3) and the Tukey test (α = 0.05). The storage times of 7 and 30 days produced no significant difference irrespective of the solution type. The formalin and thymol solutions, however, did have a negative influence on bond strength when the teeth were stored for 6 months.


Subject(s)
Animals , Cattle , Anti-Infective Agents/chemistry , Composite Resins/chemistry , Dental Bonding , Dental Restoration, Permanent/methods , Dentin-Bonding Agents/chemistry , Dentin/chemistry , Adhesiveness , Analysis of Variance , Drug Storage , Formaldehyde/chemistry , Materials Testing , Solutions/chemistry , Tensile Strength , Time Factors , Thymol/chemistry
17.
Article in English | IMSEAR | ID: sea-37973

ABSTRACT

Formalin-fixed, paraffin-embedded (FFPE) tissues are the most invaluable source of diagnostic material for studying pathogenesis of cancer and a variety of other diseases. Unfortunately, DNA extracted from formalin fixed tissues is highly degraded due to cross-linking between nucleic acid strands. Real Time PCR has become the standard for gene copy as well as RNA transcript determination. Thus, optimum standardization of Real Time PCR is crucial for obtaining accurate quantification for both research as well as for clinical diagnosis. However there are various factors which have negative impact . The aim of our study was to establish a simpler method of extraction and Real Time PCR Optimization for FFPE extracted DNA. Five breast cancer tissues that were formalin fixed and paraffin embedded were used for DNA extraction with four different methods. Extracted DNA was amplified with different primer sets that gave amplimers of different size. Optimization of Real Time PCR for EMSY, cyclin D1 and beta-globin genes was carried out on DNA obtained using heat treatment protocol for annealing temperature, primer concentration and template concentration. Highest quantity of DNA was obtained without the use of expensive reagents and in short time frame. PCR positivity was observed in case of shorter amplimer up to 250 bp in length. Amplimers of higher length failed to amplify with paraffin extracted DNA. Optimum annealing temperature for EMSY, Cyclin D1 and beta-globin genes were 60 degrees C, 60 degrees C and 61 degrees C respectively. Good results were seen with a primer concentration of 300 nM and 5 ng of template DNA. This study indicates that DNA obtained from formalin fixed paraffin embedded tissue is highly fragmented and can be used for successful amplification of shorter amplification products up to 250 bp in length. Optimization of real time PCR is important, especially while using SYBR green dye chemistry.


Subject(s)
Breast Neoplasms/genetics , DNA Primers/chemistry , DNA, Neoplasm/analysis , Electrophoresis, Agar Gel , Fixatives , Formaldehyde/chemistry , Humans , Paraffin Embedding , Polymerase Chain Reaction/methods , Time Factors , Tissue Fixation
18.
Journal of Forensic Medicine ; (6): 455-458, 2006.
Article in Chinese | WPRIM | ID: wpr-983248

ABSTRACT

Owing to the DNA degradation induced by formalin and the obstruction of paraffin to DNA extraction, it is difficult to recover high-quality DNA from Formalin fixed and paraffin embedded tissue (FFPET). In recent years, a lot of researches indicate that the DNA extraction from FFPET can be developed by improving the pretreatment, optimizing the digestion condition of proteinase, simplizing the procedures of the DNA extraction, purifying the extracted DNA and so on, which may pave a way for popularizing FFPET in DNA analysis.


Subject(s)
Humans , DNA/isolation & purification , Forensic Medicine/methods , Formaldehyde/chemistry , Hydrogen-Ion Concentration , Paraffin Embedding/methods , Polymerase Chain Reaction , Specimen Handling/methods , Time Factors , Tissue Fixation
19.
Egyptian Journal of Chemistry. 2005; 48 (2): 183-199
in English | IMEMR | ID: emr-70443

ABSTRACT

The behaviour of 4-[4'-chloro-3'-methyl phenyl]-l[2H]-phthalazinone [I] towards carbon electrophiles, e.g., ethyl bromo acetate, formaldehyde in the presence of piperidine under Mannich reaction conditions, and carbon nucleophiles, e.g., p-tolylmagnisium bromide under Grignard reaction conditions and chlorination by using PC15/POC13, has been investigated. The reaction of the chlorophthalazine derivative [6] with nitrogen nucleophiles mainly piperidine, pyrrolidine, cyclohexylamine, benzylamine and hydrazine hydrate, has been described. The behaviour of hydrazinophthalazine derivative towards carbon electrophile, e.g. aromatic aldehydes, ethyl acetoacetate and acetylacetone also has been discussed


Subject(s)
Formaldehyde/chemistry
20.
Benha Medical Journal. 2004; 21 (1): 681-605
in English | IMEMR | ID: emr-172773

ABSTRACT

In the last few decades, painting industry started to develop new types of paints "water-based paints" to replace "solvent-based ones" which contain large amounts of solvents. Water-based paints involve an. emulsion of acrylic resin, stabilizers [e.g. ammonia] and preservatives [e.g. formaldehyde] dissolved in water; that are more safe than solvent paints. To determine the respiratory and skin disorders which may affect workers in such industry, a cross-sectional study was conducted among 20 male workers in water-based paints factory in Sadat City, Menoufiya Governorate in comparison with an equal number of non exposed subjects as control group. Both groups were matched for age, sex, socioeconomic standards, education, marital status and smoking habit. All individuals were subjected to structured question naire including personal, occupational and medical histories, clinical examination, and spirometric measurements arid skin patch test. The prevalence of respiratory and skin manifestations and positive patch test results was significantly higher in exposed than control group. Also there was a trend of declining in spirometric measure ments [FVC%, FEV1%, FEV1/FVC% arid MEF] reaching a significant level or MEF% among exposed workers than in control ones. Smoking had a synergistic effect with exposure to water-based paints leading to a significant increase in the prevalence of respiratory manifestations and a significant reduction of mean of MEF%among exposed smoking workers than exposed non-smokers [108. 73 +/- 3.5and1 15.0 +/- 4,2% respectively]. There was a significant relationship between the increase in duration of exposure and increase in the prevalence of respiratory and skin manifestation and declining in MEF% among exposed workers in water-based paints industry. Usage of protective equipments was significantly valuable in minimizing the prevalence of skin manifestations [itching from 66,7% to 12..5% and dermatitis from 66.7% to 0%] among exposed personnel. Work in the water-based paints-industry was associated with increased prevalence of respiratory and skin manifestations and reduction of spirometric measurements. It is recommend that: smoking habit must be prohibited in this industry with stress on proper usage of personal protective equipments together with health education for workers in water-based paints about risk of exposure and steps to minimize the resulting disorders


Subject(s)
Humans , Male , Female , Occupational Diseases , Respiratory System Abnormalities , Skin Diseases , Acrylic Resins/toxicity , Surveys and Questionnaires , Spirometry/methods , Ammonia , Formaldehyde/chemistry
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