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J. coloproctol. (Rio J., Impr.) ; 42(1): 85-98, Jan.-Mar. 2022. tab, ilus
Article in English | LILACS | ID: biblio-1375753


Malignant neoplasms are increasingly prevalent in the daily clinical practice. Up to 61% of patients with pelvic malignancies undergo pelvic radiotherapy in different doses, which may cause intestinal damage, and the rectum is the segment most frequently affected due to its fixed position in the pelvis. Currently, there are several strategies to minimize the effects of radiation on the tissues surrounding the neoplastic site; despite those strategies, radiotherapy can still result in serious damage to organs and structures, and these injuries accompany patients throughout their lives. One of the most common damages resulting from pelvic radiotherapy is acute proctitis.The diagnosis is confirmed by visualizing the rectal mucosa through rigid or flexible rectosigmoidoscopy and colonoscopy. The objective of the present study was to review the forms of radiation-induced proctopathytherapy, and to evaluate the results of each method to propose a standardization for the treatment of this pathology. Despite the prevalence of radiation-induced proctopathy, there is no definitive standardized treatment strategy so far. The first approach can be tried with local agents, such as mesalazine and formalin. For refractory cases, control can usually be achieved with argon plasma coagulation, hyperbaric oxygen, and radiofrequency ablation therapies. Regarding the study of radiation-induced proctopathy, there is a lack of robust studies with large samples and standardized therapies to be compared. There is a lack of double-blinded, randomized controlled studies to determine a definitive standard treatment algorithm. (AU)

Proctitis/etiology , Radiotherapy/adverse effects , Colitis/therapy , Pelvic Neoplasms/radiotherapy , Rectum , Mesalamine/therapeutic use , Formaldehyde/therapeutic use , Hemorrhage
Int. j. morphol ; 38(5): 1197-1200, oct. 2020. graf
Article in English | LILACS | ID: biblio-1134424


SUMMARY: Histological techniques are the study of animal and human tissues through staining and examining them under a microscope. To demonstrate the axonal degeneration and demyelination in histological studies, the Luxol Fast Blue staining is gold standard techniques. In this study, a new histochemical method based on modified Luxol Fast Blue for the staining of the myelin sheath in sciatic nerve tissues described. The sciatic nerves of rats were removed and then the sciatic nerve was immersed in 10 % formaldehyde for one week and embedded in paraffin block. Next, thin sections (5 µm) were cut, using a microtome and stained with conventional and modified Luxol Fast Blue. Our results showed that a new method of modified Luxol Fast Blue staining can accurately identify the myelin in the sciatic nerve fibers. The current study showed that the Luxol Fast Blue combination with Light Green has a good effect on myelin coloration, and the results of this study are comparable to LFB combination with Sirius red.

RESUMEN: Las técnicas histológicas son el estudio de tejidos animales y humanos mediante tinción y examen bajo un microscopio. Para demostrar la degeneración axonal y la desmielinización en estudios histológicos, la tinción Luxol Fast Blue es una técnica estándar de oro. En este estudio, se describe un nuevo método histoquímico basado en Luxol Fast Blue modificado para la tinción de mielina en los tejidos del nervio ciático. Se seccionaron los nervios ciáticos de ratas y luego el nervio ciático se sumergió en formaldehído al 10 % durante una semana y se fijó en bloque de parafina. Posteriormente, se cortaron secciones delgadas (5 µm) usando un microtomo y se tiñeron con Luxol Fast Blue convencional y modificado. Nuestros resultados mostraron que un nuevo método de tinción Luxol Fast Blue modificado puede identificar con precisión la mielina en las fibras del nervio ciático. El estudio actual mostró que la combinación Luxol Fast Blue con Light Green es un buen efecto sobre la coloración de mielina, y los resultados de este estudio son comparables a la combinación LFB con Sirius red.

Animals , Rats , Sciatic Nerve/anatomy & histology , Staining and Labeling/methods , Myelin Sheath , Paraffin , Histological Techniques , Formaldehyde , Microscopy/methods
Int. j. morphol ; 38(5): 1371-1375, oct. 2020. tab, graf
Article in English | LILACS | ID: biblio-1134450


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.

Tissue Fixation/methods , Alcohols/chemistry , Fixatives , Formaldehyde/chemistry , Chloroform/chemistry , Acetic Acid/chemistry , Methanol/chemistry
Rev. Fac. Med. (Bogotá) ; 68(3): 425-437, July-Sept. 2020. tab, graf
Article in English | LILACS, COLNAL | ID: biblio-1143732


Abstract Introduction: Formaldehyde is a substance widely used in the industry; however, it is classified as mutagenic and carcinogenic to humans. In order to determine the risk of workers who are occupationally exposed to formaldehyde, it is necessary to monitor its environmental concentration levels and the biomarkers that allow identifying its potential health effects. Unfortunately, in Colombia there are not guidelines on occupational exposure to this substance. Objective: To review recent studies on occupational exposure to formaldehyde to design a monitoring and surveillance strategy for Colombian workers exposed to this substance. Materials and methods: A literature review was conducted in PubMed, MedLine, Science-Direct and Embase using the following search strategy: articles on occupational exposure to formaldehyde published in English or Spanish between 2013 and 2017. The following search terms were used: "occupational exposure", "formaldehyde" "mutagenicity test" y "DNA adducts" and their Spanish equivalents. Results: The initial search yielded 103 articles, of which only 36 met the inclusion criteria. Conclusions: Proper management of the risk derived from occupational exposure to formaldehyde, as well as the appropriate medical follow-up of these workers, requires the implementation of a series of interdisciplinary actions that allow the creation of a comprehensive occupational health surveillance system for workers exposed to this substance.

Resumen Introducción. El formaldehido es una sustancia ampliamente usada a nivel industrial; sin embargo, es considerada un agente mutagénico y carcinógeno para los humanos. Para determinar el grado de riesgo de los trabajadores ocupacionalmente expuestos (TOE) al formaldehido, debe hacerse un seguimiento de sus niveles de concentración ambiental y de los biomarcadores que permiten identificar su daño potencial para la salud. En Colombia, lamentablemente, no existen lineamientos respecto a la exposición ocupacional a esta sustancia. Objetivo. Revisar estudios recientes sobre exposición ocupacional a formaldehido para diseñar una estrategia de seguimiento y vigilancia de los TOE a esta sustancia en Colombia. Materiales y métodos. Se realizó una revisión de la literatura en PubMed, MedLine, ScienceDirect y Embase mediante la siguiente estrategia de búsqueda: artículos sobre exposición ocupacional a formaldehido publicados en inglés o español entre 2013 y 2017. Los términos de búsqueda fueron "occupational exposure", "formaldehyde" "mutagenicity test" y "DNA adducts" y sus equivalentes en español. Resultados. La búsqueda inicial arrojó 103 registros, sin embargo solo 36 artículos cumplieron los criterios de inclusión establecidos. Conclusiones. La gestión adecuada del riesgo derivado de la exposición ocupacional a formaldehido, asi como el seguimiento médico apropiado de estos trabajadores, requiere la implementación de una serie de acciones interdisciplinarias que permitan la creación de un sistema de vigilancia ocupacional integral de los TOE a esta sustancia.

Occupational Exposure , Biomarkers , Formaldehyde , Mutagenicity Tests
Electron. j. biotechnol ; 44: 58-59, Mar. 2020. ilus
Article in English | LILACS | ID: biblio-1087710


BACKGROUND: Methanol can be effectively removed from air by biofiltration (Shareefdeen et al., 1993; Babbitt et al., 2009 [1,2]). However, formaldehyde is one of the first metabolic intermediates in the consumption of methanol in methylotrophic microorganisms (Negruta et al., 2010 [3]), and it can be released out of the cell constituting a secondary emission. RESULTS: The total removal of methanol was achieved up to input loads of 263 g m−3 h−1 and the maximum elimination capacity of the system was obtained at an empty bed residence times of 90 s and reached 330 g m−3 h−1 at an input methanol load of 414 g m−3 h−1 and 80% of removal efficiency. Formaldehyde was detected inside the biofilter when the input methanol load was above 212 g m−3 h−1 . Biomass in the filter bed was able to degrade the formaldehyde generated, but with the increase of the methanol input load, the unconsumed formaldehyde was released outside the biofilter. The maximum concentration registered at the output of the system was 3.98 g m−3 when the methanol load was 672 g m−3 h−1 in an empty bed residence times of 60 s. CONCLUSIONS: Formaldehyde is produced inside a biofilter when methanol is treated in a biofiltration system inoculated with Pichia pastoris. Biomass present in the reactor is capable of degrading the formaldehyde generated as the concentration of methanol decreases. However, high methanol loads can lead to the generation and release of formaldehyde into the environment.

Pichia/chemistry , Methanol/chemistry , Formaldehyde/analysis , Volatilization , Biological Filters , Biomass , Bioreactors , Environment
Rev. ciênc. farm. básica apl ; 41: [10], 01/01/2020. tab, ilus
Article in English | LILACS | ID: biblio-1128576


Formaldehyde is an active compound, irregularly used in hair products, that has the property of straighten and waterproofing the wires. However, it is highly toxic and can stimulate dermatological hypersensitivity and cancer. In this context it is of fundamental importance the inspection of these products that can be used in safe conditions for the consumer, without formaldehyde in concentrations higher than the allowed. Thus, the aim of this research was the qualitative and quantitative identification formaldehyde in samples of hair straighteners that was obtained by donation in the beauty salons of Araraquara-SP. In addition, the analysis of the packaging labels of the products tested were conducted, following the requirements of the national legislation - RDC 07/2015 which defines the mandatory labeling standards for cosmetic products. A qualitative analysis for formaldehyde identification is based on the formation of a purple colored complex. The quantitative analysis was performed by spectrophotometry. The qualitative and quantitative formaldehyde analysis methods were applied to 13 bottles of hair straighteners. When submitted to qualitative analysis, all samples showed formaldehyde presence. The quantitative analysis demonstrated that the samples identified as B, C, D, E, G, H, I, J and M presented formaldehyde concentration of 3.5 to 14.5%, which is above of the limit recommended by the National Health Surveillance Agency (ANVISA), of 0.2%. In the label analysis, in all samples were found irregularities.(AU)

Humans , Product Labeling/legislation & jurisprudence , Cosmetics/analysis , Formaldehyde/analysis , Hair , Spectrophotometry/methods , Indicators and Reagents/administration & dosage
Acta Physiologica Sinica ; (6): 463-474, 2020.
Article in Chinese | WPRIM | ID: wpr-827040


Formaldehyde is one of the simplest organic small molecules containing C, H and O elements in the early stage of earth's evolution; however, it has been found to be existed in every eukaryotic cell and participate in "one carbon metabolism". Recent studies have shown that formaldehyde may act as a signal molecule to regulate memory formation. After electrical stimulation or learning activity, the levels of formaldehyde in rat brains were increased instantly, and N-methyl-D-aspartate (NMDA) receptor was activated to promote the formation of long-term potentiation (LTP) or spatial memory. On the contrary, after reducing the levels of formaldehyde in the brains, NMDA receptor could not be activated, which was accompanied by the deficits in both LTP and memory. Moreover, in the brains of normal aged rats and APP/PS1 transgenic mice, the concentrations of formaldehyde were abnormally increased, which directly inhibited NMDA receptor activity and impaired spatial memory. This article reviewed the physiological and pathophysiological functions of endogenous formaldehyde in learning and memory.

Animals , Formaldehyde , Hippocampus , Long-Term Potentiation , Maze Learning , Memory , Memory Disorders , Mice , Rats , Receptors, N-Methyl-D-Aspartate
Chinese Journal of Biotechnology ; (12): 942-948, 2020.
Article in Chinese | WPRIM | ID: wpr-826882


It is of great significance to use biosynthesis to transform the inorganic substance formaldehyde into organic sugars. Most important in this process was to find a suitable catalyst combination to achieve the dimerization of formaldehyde. In a recent report, an engineered glycolaldehyde synthase was reported to catalyze this reaction. It could be combined with engineered D-fructose-6-phosphate aldolase, a "one-pot enzyme" method, to synthesize L-xylose using formaldehyde and the conversion rate could reach up to 64%. This process also provides a reference for the synthesis of other sugars. With the increasing consumption of non-renewable resources, it was of great significance to convert formaldehyde into sugar by biosynthesis.

Biocatalysis , Formaldehyde , Chemistry , Fructose-Bisphosphate Aldolase , Metabolism , Xylose
Article in English | WPRIM | ID: wpr-782293


0.05). Dogs inoculated with the former vaccine developed a significantly higher immune titer than non-vaccinated dogs.CONCLUSION: The Cabopol-adjuvanted, inactivated CAV-2 vaccine was safe and induced a high VNA titer in dogs.

Adenoviruses, Canine , Amino Acids , Animals , Dogs , Enzyme-Linked Immunosorbent Assay , Formaldehyde , Guinea Pigs , Madin Darby Canine Kidney Cells , Urea , Vaccines
Actual. osteol ; 15(3): 205-213, Sept-Dic. 2019. ilus, tab
Article in English | LILACS | ID: biblio-1104336


The dental caries is a progressive destruction of the teeth tissue due to the disbalance in the normal molecule interactions between the enamel and the bio!lm, which alters the demineralization-remineralization process. Milk fermentation produces caseinphosphopeptides with proved remineralizing capacity of the enamel. The presence of these peptides in fermented milk with ke!r grains has been described. The purpose of this work was to evaluate in vitro the capacity of milk ke!r to prevent the demineralization of dental enamel. Bovine incisors (n=68, 17 per group) were treated for 72 h with different solutions: I: artificial saliva at pH 7.2 , II: demineralizing solution at pH 4.5, III: supernatant of kefir fermented milk at pH 4.5, IV: milk supernatant at pH 4.5. The effects of treatments were evaluated by the change in the weight of the specimens, calcium concentration in the solution and by scanning electron microscopy (SEM) of the enamel. Kefir milk supernatant prevented the demineralization process, that was evidenced by a change in weight and calcium concentration that were not different from group I, although the pH was 4.5. In contrast, group IV showed a decrease in weight and an increase in calcium concentration, compared with group I (one way ANOVA, p<0.05). Images of SEM agree with the values of weight and calcium concentration. These results indicate that kefir milk supernatant has a protective effect on enamel demineralization in vitro. (AU)

La caries dental es una patología debido a un desequilibrio en las interacciones moleculares normales entre el esmalte y la biopelícula, que altera el proceso de desmineralización remineralización. La fermentación de la leche produce fosfopéptidos de caseína con probada capacidad remineralizante del esmalte, y se ha descripto la presencia de estos péptidos en la leche fermentada con granos de kéfir. El propósito de este trabajo fue evaluar in vitro la capacidad del kéfir de leche para prevenir la desmineralización del esmalte dental. Sesenta y ocho incisivos bovinos (17 por grupo) fueron tratados durante 72 h con diferentes soluciones: I: saliva artificial, pH 7.2, II: solución desmineralizante, pH 4.5, III: sobrenadante de leche fermentada con kefir, pH 4.5, IV: sobrenadante de leche, pH 4.5. El proceso de desmineralización se evaluó mediante el cambio en el peso de las muestras, la concentración de calcio en la solución y microscopía electrónica de barrido (SEM) del esmalte. El sobrenadante de leche fermentada con kéfir impidió el proceso de desmineralización, que se evidenció por un cambio en el peso y la concentración de calcio que no discreparon del grupo I, a pesar de haber tenido un pH de 4.5. En contraste, el grupo IV mostró una disminución en el peso y un aumento en la concentración de calcio, en comparación con el grupo I (ANOVA a un criterio, p<0.05). Las imágenes SEM concuerdan con los cambios en el peso y la concentración de calcio en los grupos estudiados. Los datos obtenidos demuestran que el sobrenadante de la leche tratada con kéfir tiene un efecto protector sobre la desmineralización del esmalte in vitro, inducida por el pH ácido. (AU)

Animals , Cattle , Tooth Demineralization/prevention & control , Kefir/microbiology , Saliva, Artificial/administration & dosage , Tooth Remineralization/methods , In Vitro Techniques , Cattle , Caseins/therapeutic use , Calcium/analysis , Tooth Demineralization/pathology , Tooth Demineralization/therapy , Biofilms , Dental Caries/prevention & control , Dental Enamel/cytology , Dental Enamel/physiopathology , Milk/microbiology , Formaldehyde/administration & dosage
Arq. ciências saúde UNIPAR ; 23(3): 157-161, set-dez. 2019.
Article in Portuguese | LILACS | ID: biblio-1046142


O processo de alisamento capilar é uma prática comum realizada nos salões de beleza. O procedimento exige a utilização de substâncias com capacidade de rompimento das cadeias dissulfídricas da fibra capilar com posterior modelamento para o efeito desejado, sendo o formol um dos compostos mais utilizados para esta finalidade, porém indevidamente. De acordo com a legislação vigente, o formol só pode ser utilizado em produtos cosméticos com a função de conservante em uma concentração máxima de 0,2%. Devido a seu uso incorreto em produtos capilares o presente trabalho teve como objetivo realizar uma análise semi-quantitativa da presença de formol em amostras de alisantes capilares, bem como verificar o pH destes produtos. Foram obtidas 22 amostras de alisantes capilares doadas por salões de beleza da região de Umuarama - PR. A determinação da presença de formol foi realizada através da reação de Shiff e comparação com escala colorimétrica de concentrações padronizadas de formaldeído variando de 0,005% a 10%. A verificação do pH foi realizada através da preparação de soluções aquosas de 10% do alisante e posterior aferição em pHmetro digital. Das amostras analisadas, verificou-se 22,72% encontraram-se em conformidade, apresentando quantidade de formaldeído adequada com a legislação (até 0,2%) ou ausência do composto, enquanto que 77,28% apresentaram valores acima do permitido. Já o pH adequado foi constatado em apenas 13,64% amostras. O uso incorreto ou exagerado do formol pode acarretar danos à saúde, como cefaléia, dispnéia, queimadura, edema pulmonar e até câncer. Uma maior fiscalização deve ser realizada nos estabelecimentos que realizam procedimentos de alisamento capilar, bem como nas indústrias produtoras e ainda em importadoras, para uma melhor garantia do cumprimento da legislação tanto para a preservação da saúde dos profissionais quando dos usuários.

The hair-straightening process is a common practice in most beauty salons. The procedure requires the use of substances capable of disrupting the disulfide chains of the hair fiber with subsequent modeling for the desired effect, with formaldehyde being one of the most commonly but improperly used compounds for this purpose. According to the current legislation, formaldehyde can only be used in cosmetic products as a preservative function in a maximum concentration of 0.2%. Due to its incorrect use in capillary products, this work has the purpose of developing a semi-quantitative analysis of the presence of formaldehyde in samples of hair straighteners, as well as verifying the pH of those products. Twenty-two samples of hair straighteners were donated by beauty salons from the region of Umuarama-PR. The determination of the presence of formaldehyde was performed using the Shiff reaction and compared using the colorimetric scale for standard formaldehyde concentrations varying from 0.005% to 10%. The pH verification was carried out by the preparation of 10% aqueous solutions of the straightener and subsequent measurement in a digital pH meter. From the analyzed samples, 22.72% were found to be in compliance, presenting the amount of formaldehyde within the legislation (up to 0.2%) or absence of the compound, while 77.28% presenting values above the legal limitations. Additionally, adequate pH was verified in only 13.64% of the samples. Incorrect or exaggerated use of formaldehyde can lead to health issues, such as headache, dyspnea, burns, pulmonary edema and even cancer. Greater surveillance should be carried out in establishments that perform hair straightening procedures as well as in the producing and importing industries in order to guarantee better compliance with the legislation both for the preservation of the health of professionals and users alike.

Colorimetry/methods , Formaldehyde/toxicity , Hair/chemistry , Pulmonary Edema , Burns
Electron. j. biotechnol ; 40: 10-16, July. 2019. tab, ilus, graf
Article in English | LILACS | ID: biblio-1053200


Background: Methanol can be effectively removed from air by biofiltration. However, formaldehyde is one of the first metabolic intermediates in the consumption of methanol in methylotrophic microorganisms, and it can be released out of the cell constituting a secondary emission. Results: The total removal of methanol was achieved up to input loads of 263 g m−3 h−1 and the maximum elimination capacity of the system was obtained at an empty bed residence times of 90 s and reached 330 g m− 3 h−1 at an input methanol load of 414 g m−3 h−1 and 80% of removal efficiency. Formaldehyde was detected inside the biofilter when the input methanol load was above 212 g m−3 h−1 . Biomass in the filter bed was able to degrade the formaldehyde generated, but with the increase of the methanol input load, the unconsumed formaldehyde was released outside the biofilter. The maximum concentration registered at the output of the system was 3.98 g m−3 when the methanol load was 672 g m−3 h−1 in an empty bed residence times of 60 s. Conclusions: Formaldehyde is produced inside a biofilter when methanol is treated in a biofiltration system inoculated with Pichia pastoris. Biomass present in the reactor is capable of degrading the formaldehyde generated as the concentration of methanol decreases. However, high methanol loads can lead to the generation and release of formaldehyde into the environment

Pichia/metabolism , Methanol/metabolism , Formaldehyde/metabolism , Biomass , Air Pollutants , Environment , Filtration
Int. j. morphol ; 37(2): 533-540, June 2019. tab
Article in Spanish | LILACS | ID: biblio-1002255


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.

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


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.

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
Article in English | WPRIM | ID: wpr-758884


Monoclonal antibodies (MAbs) are widely applied in disease diagnoses. Herein, we report a MAb, WF-4, against Influenza A virus nucleoprotein (NP), its broad response with Influenza A virus, and its application in an immunohistochemistry (IHC) assay. WF-4 was screened by immunofluorescence assay (IFA). The results showed that its reactivity with baculovirus-expressed full-length recombinant NP (rNP) in Western blot (WB), indicating its IHC applicability. Fifteen Influenza A virus (reference subtypes H1 to H15) infected chicken embryonated chorioallantoic membranes (CAM), fixed by formalin, were all detectable in the WF-4-based IHC assay. Also, the reactivity of the IHC test with NP from experimentally inoculated H6N1 and from all recent outbreaks of H5 subtype avian Influenza A virus (AIV) field cases in Taiwan showed positive results. Our data indicate that CAM, a by-product of Influenza A virus preparation, is helpful for Influenza A virus-specific MAb characterization, and that the WF-4 MAb recognizes conserved and linear epitopes of Influenza A virus NP. Therefore, WF-4 is capable of detecting NP antigens via IHC and may be suitable for developing various tests for diagnosis of Influenza A virus and, especially, AIV infection.

Animals , Antibodies, Monoclonal , Blotting, Western , Chickens , Chorioallantoic Membrane , Diagnosis , Disease Outbreaks , Epitopes , Fluorescent Antibody Technique , Formaldehyde , Immunohistochemistry , Influenza A virus , Influenza in Birds , Influenza, Human , Nucleoproteins , Taiwan
Article in English | WPRIM | ID: wpr-739800


BACKGROUND: This study investigated the role of NR2B in a modulated pain process in the painful diabetic neuropathy (PDN) rat using various pain stimuli. METHODS: Thirty-two Sprague-Dawley male rats were randomly allocated into four groups (n=8): control, diabetes mellitus (DM) rats and diabetic rats treated with ifenprodil at a lower dose (0.5 µg/day) (I 0.5) or higher dose (1.0 µg/day) (I 1.0). DM was induced by a single injection of streptozotocin at 60 mg/kg on day 0 of experimentation. Diabetic status was assessed on day 3 of the experimentation. The responses on both tactile and thermal stimuli were assessed on day 0 (baseline), day 14 (pre-intervention), and day 22 (post-intervention). Ifenprodil was given intrathecally for 7 days from day 15 until day 21. On day 23, 5% formalin was injected into the rats' hind paw and the nociceptive responses were recorded for 1 hour. The rats were sacrificed 72 hours post-formalin injection and an analysis of the spinal NR2B expression was performed. RESULTS: DM rats showed a significant reduction in pain threshold in response to the tactile and thermal stimuli and higher nociceptive response during the formalin test accompanied by the higher expression of phosphorylated spinal NR2B in both sides of the spinal cord. Ifenprodil treatment for both doses showed anti-allodynic and anti-nociceptive effects with lower expression of phosphorylated and total spinal NR2B. CONCLUSION: We suggest that the pain process in the streptozotocin-induced diabetic rat that has been modulated is associated with the higher phosphorylation of the spinal NR2B expression in the development of PDN, which is similar to other models of neuropathic rats.

Animals , Diabetes Mellitus , Diabetic Neuropathies , Formaldehyde , Humans , Hyperalgesia , Male , N-Methylaspartate , Pain Measurement , Pain Threshold , Phosphorylation , Rats , Rats, Sprague-Dawley , Receptors, N-Methyl-D-Aspartate , Spinal Cord , Streptozocin
Anatomy & Cell Biology ; : 255-261, 2019.
Article in English | WPRIM | ID: wpr-762238


In this study, a restoration process was developed with potassium hydroxide (KOH), in order to improve each of the structures for their posterior fixation, through the use of new methods such as the Chilean conservative fixative solution (SFCCh), with exceptional results. Restore anatomical pieces corresponding to corpse and organs, being these last set with the SFCCh. In this work dealt with processes of restoration with potassium hydroxide, sodium chloride, and sodium hypochlorite, the process began with the cleanliness and suture of the structures for subsequent fixing in Chilean conservative fixative solution, making use of a corpse and different anatomical parts. Work based on items found in the database, Elsevier, Science Direct, ProQuest, and MEDLINE. At the end of the process of restoration and conservation of the anatomical pieces, was observed an improvement in muscle pigment with decrease of rigidity in the specimen, additionally a recovery of appearance in the vascular-nervous elements was achieved. The organs were much more malleable and the structures facilitate the identification of specific details, its subsequent immersion in SFCCh allows the longer preservation of the obtained results. The restoration with potassium hydroxide allows the improvement in the appearance of the different anatomical structures and simultaneously to facilitate its study. The SFCCh is an alternative that replaces partially the use of formaldehyde. In addition, it presents toxicity reduction.

Cadaver , Formaldehyde , Immersion , Potassium , Sodium Hydroxide , Sodium Hypochlorite , Sutures
Anatomy & Cell Biology ; : 262-268, 2019.
Article in English | WPRIM | ID: wpr-762237


The knowledge about detailed morphology and relation of saphenous nerve is important to obtain successful saphenous nerve regional blocks to achieve pre- and post-operative anesthesia and analgesia, nerve entrapment treatments and to avoid damage of saphenous nerve during knee and ankle surgeries. The literature describing detailed morphology of saphenous nerve is very limited. We dissected 42 formalin fixed well embalmed cadaveric lower limbs to explore detailed anatomy, relation and mode of termination of saphenous nerve and measured the distances from the nearby palpable bony landmarks. The average distance of origin of saphenous nerve from inguinal crease was 7.89±1.42 cm, the distance from upper end of medial border of patella to saphenous nerve at that level was 8.11±0.85 cm, distance from tibial tuberosity was 7.53±0.98 cm and from midpoint of anterior border of medial malleolus was 0.45±0.14 cm. Saphenous nerve provided two infrapatellar branches at the level of mid to lower limit of patellar ligament in 90% cases. It was in close contact or adhered to great saphenous vein across the lower 2/3rd of leg lying either anterior, posterior or deep to the vein. The saphenous nerve terminated by bifurcating proximal to medial malleolus in majority of cases though no obvious bifurcation was observed in 9.52% cases. The detailed morphology, relations and the distances from palpable bony landmarks may be helpful for clinicians to achieve successful saphenous nerve block and to avoid saphenous nerve damage and related complications during orthopedic procedures.

Anesthesia and Analgesia , Ankle , Cadaver , Deception , Formaldehyde , Knee , Leg , Lower Extremity , Nerve Block , Nerve Compression Syndromes , Orthopedic Procedures , Patella , Patellar Ligament , Saphenous Vein , Veins