Alcohol-based fixatives can better preserve tissue morphology than formalin / Fijadores a base de alcohol pueden preservar mejor la morfología tisular que la formalina

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.

Purification of inulinases by changing the ionic strength of the medium and precipitation with alcohols

ABSTRACT The present study evaluated the purification of inulinase by changing the ionic strength of the medium by addition of NaCl and CaCl2 followed by precipitation with n-propyl alcohol or iso-propyl alcohol. The effects of the concentration of alcohols and the rate of addition of alcohols in the crude extract on the purification yield and purification factor were evaluated. Precipitation caused an activation of enzyme and allowed purification factors up to 2.4-fold for both alcohols. The purification factor was affected positively by the modification of the ionic strength of the medium to 0.5 mol.L-1 NaCl before precipitation with the alcohol (n-propyl or iso-propyl). A purification factor of 4.8-fold and an enzyme yield of 78.1 % could be achieved by the addition of 0.5 mol.L-1 of NaCl to the crude extract, followed by the precipitation with 50 % (v/v) of n-propyl alcohol, added at a flow rate of 19.9 mL/min.

Protective effect of Tribulus terrestris hydroalcoholic extract against cisplatin-induced cytotoxicity on sperm parameters in male mice / Efecto protector del extracto hidroalcohólico de Tribulus terrestris contra la citotoxicidad inducida por cisplatino sobre parámetros espermáticos en ratones macho

Cisplatin is an anti-cancer drug used in chemotherapy. One of the limiting side effects of cisplatin is decreasing genital gland function, azoospermia and oligospermia. Tribulus terrestris has been used as an aphrodisiac. The present study amid to investigate protective effect of Tribulus terrestris hydroalcoholic extract against cisplatin-induced cytotoxicity on sperm parameters in mice. Male adult mice (n=30) were divided into control and 4 experimental groups (n=6). Control group received saline, first experimental group received cisplatin (5.5 mg/kg) and other three experimental groups received cisplatin (5.5 mg/kg) and different doses of hydroalcoholic extact of Tribulus terrestris (100, 300 and 500 mg/kg/i.p) respectively. On the day after the last injection, blood samples were collected for serum Nitric oxide (NO) assay. Also weights of body and testis, sperm parameters and seminiferous tubules diameter were assessed. Data analysis was performed using one-way ANOVA followed by Tukeys' test. The results showed that cisplatin lead to a reduction in the weight of body and testes, sperm parameters and increased level serum of NO significantly compared to the control group (P<0.05), while in treated groups with Tribulus terrestris, the weights of body and testes, sperm parameters, seminiferous tubules diameter were significantly higher compared with cisplatin group (P<0.05), but serum level of NO did not show significant differences. The study demonstrates that extract of Tribulus terrestris could protective effect against cisplatin- induced cytotoxicity on sperm parameters that may be related to the presence of antioxidant components acting via a multitude of central and peripheral mechanisms.

El cisplatino es un medicamento contra el cáncer utilizado en la quimioterapia. Uno de los efectos secundarios limitantes de cisplatino es la decreciente función glándular genital, azoospermia y oligospermia. Tribulus terrestris ha sido utilizado como un afrodisíaco. En el presente estudio se investiga el efecto protector del extracto hidroalcohólico de Tribulus terrestris (TT) contra la citotoxicidad inducida por cisplatino en los parámetros espermáticos en ratones. Ratones adultos machos (n = 30) fueron divididos en 4 grupos control y experimentales (n = 6). En el grupo control se administró solución salina, el primer grupo experimental recibió cisplatino (5,5 mg/kg) mientras que otros tres grupos experimentales recibieron cisplatino (5.5 mg/kg) además de diferentes dosis de extracto hidroalcohólico de TT (100, 300 y 500 mg/kg/IP) respectivamente. El día siguiente de la última inyección, se analizaron muestras de sangre para expresión de óxido nítrito (ON). Además, fueron evaluados el peso del cuerpo y testículos, los parámetros espermáticos y el diámetro de los túbulos seminíferos. Los datos fueron analizados mediante análisis ANOVA y la prueba de Tukey. El uso de cisplatino causó reducción del peso corporal y testicular, parámetros espermáticos y aumento significativo de los valores de ON en comparación con el grupo control (P<0,05), mientras que los grupos tratados con TT, fue significativamente mayor el peso corporal y testicular, parámetros espermáticos y diámetro de los túbulos seminíferos en comparación al grupo tratado con cisplatino (P<0,05). No se observaron diferencias significativas en los valores ON. El extracto de TT puede tener un efecto protector frente a la citotoxicidad inducida por el cisplatino sobre los parámetros espermáticos, al estar relacionado a la presencia de componentes antioxidantes que actúan mediante mecanismos centrales y periféricos.

Antisépticos: una visión química / The antiseptic ones: a chemical vision

En la actualidad, los antis‚pticos son ampliamente usados en hospitales y en otros centros de salud en una variedad de aplicaciones tópicas y de superficie. Los antis‚pticos son sustancias qu¡micas que se aplican sobre pie, heridas o cortes, con la finalidad de destruir o inhibir el crecimiento de microorganismos patógenos. En el presente trabajo se busca resaltar el conocimiento qu¡mico necesario, tales como la composición, concentración qu¡mica y modo de acción de tres de los antisépticos m sésencillos y de uso común como son el alcohol, agua oxigenada y el alcohol yodado.

Antiseptics are extensively used in hospitals and other health care settings for a variety of topical and hard-surface applications. There are chemicals that are applied on skin, wounds or cuts, in order to destroy or inhibit the growth of pathogenic microorganisms. This paper seeks to highlight the necessary chemical knowledge, such as composition, chemical concentration and mode of action of three antiseptics simple and commonly used, such as alcohol, peroxide and iodine alcohol.

Role of dilute alcohol in the removal of fine wrinkles from paraffin sections, a histo-technical study / Rol del alcohol diluido en la eliminación de arrugas finas desde secciones de parafina, un estudio histotécnico

Histotechnology is concerned with processing and preparing of the body tissue in such a manner as to enable a satisfactory study of it. Section cutting is an integral part of histology and histopathology. It is an art by itself requiring skill and knowledge on the part of technician or the person who needs to do section cutting. In the routine method of preparing paraffin sections, it is often encountered by the presence of artefacts like fine wrinkles or folds. Attempts have been made to remove the wrinkles by floating the sections in the warm water bath. However this method has not been able to remove all the wrinkles from the sections. We have designed a simple and reliable method, in which the paraffin sections were floated over the ethyl alcohol diluted with water (1:15) before they were placed in the water bath. Through this method, we have been able to get the wrinkle free sections of superior quality. The advantage of our method is that, it is easy to prepare the dilute alcohol and is cost effective. This method can be used by the histology and pathology technicians and the researchers.

Histotecnología se refiere a la elaboración y preparación de los tejidos del cuerpo de tal forma que permitan un estudio satisfactorio de éste. El corte seccionado es una parte integral de la histología y la histopatología. Es un arte por sí mismo que requiere habilidad y conocimiento por parte del técnico o la persona que tiene que hacer el corte de la sección. En el método de rutina de la preparación de las secciones de parafina se encuentra a menudo la presencia de artefactos como arrugas finas o pliegues. Se han hecho intentos para eliminar las arrugas por flotación de las secciones en el baño de agua tibia. Sin embargo, este método no ha sido capaz de eliminar todas las arrugas de las secciones. Hemos diseñado un método sencillo y fiable, en el que las secciones de parafina fueron colocadas por flotación sobre alcohol etílico diluido con agua (1:15) antes de ser colocado en el baño de agua. A través de este método, hemos sido capaces de obtener secciones sin arrugas de calidad superior. La ventaja de nuestro método es que, es fácil de preparar el alcohol diluido y es rentable. Este método puede ser utilizado por los técnicos de histología, patología e investigadores.

Queimaduras com álcool em crianças: realidade brasileira e vulnerabilidades / Alcohol burns in children: Brazilian reality and vulnerabilities

Grande número de casos de queimaduras com álcool entre adultos e crianças é frequentemente apontado nas casuísticas nacionais. A Resolução da ANVISA (Agência Nacional de Vigilância Sanitária) de 2002, que restringia a comercialização de álcool em grandes concentrações para uso doméstico, foi o reconhecimento oficial da existência deste tipo de queimadura como um problema social e de saúde pública. Dias antes de findar o prazo de adequação à medida, os maiores fabricantes do produto foram liberados de a acatarem. Passados alguns anos, buscou-se, na presente tese de doutorado, apreciar quesitos surgidos no debate de então, os quais ainda permanecem, dada sua relevância. Para melhor evidenciar os contornos e as implicações da questão abordada pela iniciativa governamental, este trabalho teve como objetivos: caracterizar a magnitude do problema das queimaduras no Brasil através da análise crítica das informações disponíveis e reconhecer os tipos mais frequentes da lesão; descrever a casuística de um centro brasileiro de referência no tratamento de queimaduras e situá-la em relação ao contexto nacional e internacional; caracterizar cenários e circunstâncias em que crianças foram vítimas de queimaduras com álcool, dentro de uma população delimitada; interpretar, instruídos pelo conceito de vulnerabilidade, as relações dinâmicas e as combinações existentes entre as condições individuais e sociais presentes nos contextos em que crianças sofrem queimaduras com álcool. A investigação empírica aliou ao método epidemiológico descritivo o enfoque qualitativo, apoiado em entrevistas em profundidade a partir de roteiro temático. Os dados permitiram sustentar que o Brasil exibe em seu perfil epidemiológico características que não são encontradas na literatura produzida em outras partes do mundo: alta proporção de queimaduras com álcool entre pacientes hospitalizados, sejam adultos ou crianças.

Density and speed of sound of sodium nitroprusside with aqueous alcohols

Studies on apparent molar volumes for the solutions of sodium nitroprusside in aqueous solutions of methanol, ethanol and propanol in the temperature range 298.15 to 313K at 5K intervals have been determined from the density measurements of the solutions. Speed of sound of solutions of sodium nitroprusside in aqueous solutions of alcohols has also been experimentally determined at 304.15K. Molar insentropic compressibilities and apparent molar isentropic compressibilities have been calculated from the speed of sound data. These results have been used to calculate the following partial molar quantities: V[phi], E[0][phi], K[0][s][phi] Various acoustic parameters and salvation number have been evaluated for sodium nitroprusside in different aqueous solutions of alcohols. The results are discussed in the light of solute-solvent and solute-solute interactions

Kinetics of oxidation of adenosine by tert-butoxyl radicals: Protection and repair by chlorogenic acid.

The rates of oxidation of adenosine and chlorogenic acid by tert-butoxyl radicals (t-BuO-) were studied by measuring the absorbance of adenosine at 260 nm and chlorogenic acid at 328 nm spectrophotometrically. t-BuO- radicals were generated by the photolysis of tert-butyl hydroperoxide (t-BuOOH) in presence of tert-butyl alcohol to scavenge OH. radicals. The rates and the quantum yields() of oxidation of chlorogenic acid by t-BuO-radicals were determined in the absence and presence of varying concentrations of adenosine. An increase in the concentration of adenosine was found to decrease the rate of oxidation of chlorogenic acid, suggesting that adenosine and chlorogenic acid competed for t-BuO. radicals. From competition kinetics, the rate constant of chlorogenic acid reaction with t-BuO- was calculated to be 3.20 109 dm3 mol-1 s-1. The quantum yields (expt) were calculated from the experimentally determined rates of oxidation of chlorogenic acid under different experimental conditions. Assuming that chlorogenic acid acts as a scavenger of t-BuO- radicals only, the quantum yields (cal) were theoretically calculated. expt and cal values suggested that chlorogenic acid not only protected adenosine from t-BuO- radicals, but also repaired adenosine radicals, formed by the reaction of adenosine with t-BuO- radicals.

Effects of alcoholic extract of Momordica charantia (Linn.) whole fruit powder on the pancreatic islets of alloxan diabetic albino rats.

Alcoholic extract of whole fruit of Momordica charantia was prepared. Adult healthy albino rats were divided into four groups and received a dose of 6 mg/l00 gm. body weight of alloxan monohydrate. Animals of group I served as diabetic control group. The animals of II, III, and IV groups received 25 mg, 50 mg and 75 mg doses of the extract respectively for different durations. 75 mg dose showed increase in body weight. All doses of alcoholic extract of M. charantia were able to decrease the blood sugar level significantly. Extract feeding showed definite improvement in the islets of Langerhans. No toxic effect was observed in the liver The significant features of the study have been blood glucose once lowered by the treatment with M. charantia fruit extract remained static even after discontinuation of drug for 15 days. Blood sugar never fell below normal values even with a high dose, in pancreatic islets, beta cells showed definite improvement.

Efecto de alcoholes lipofílicos en el reparto de surfactantes nonilfenol polietoxilados en sistemas aceite/microemulsión/agua / Effect of lipophilic alcohols in the partitioning of nonylphenol polyethoxylated surfactants in oil/microemulsion/water systems

El comportamiento de fases en un sistema surfactante-agua-aceite se afecta por las llamadas variables de formulación, por ejemplo, por la naturaleza de los componentes o su ambiente fisicoquímico. Una de estas variables es la presencia del tipo y concentración de alcohol en el sistema. Para estudiar este efecto se realizaron barridos de formulación variando el número de óxido de etileno (EON) del sistema, por medio de la mezcla de un surfactante lipofílico con otro hidrofílico con el fin de hallar el sistema de máxima solubilidad (Winsor III óptimo) e incorporar en este sistema los alcoholes a diferentes concentraciones para observar el cambio de transición. El reparto se determinó por cromatografía líquida de alta resolución (HPLC). La adición de alcoholes lineales lipofílicos a estos sistemas proporciona mayor polaridad a la fase oleica y por ende mayor fraccionamiento hacia la misma. Se encontró que si la cadena alquílica del co-surfactante está por encima de un número de átomos de carbono promedio del alcohol (ACAN, acrónimo del inglés “alcohol carbon atom number”) igual a 4,5 el 50 por ciento del fraccionamiento no se ve afectado por el incremento de la concentración ni por el tipo de alcohol lipofílico.

Phase behavior in surfactant-water-oil systems is affected by the so-called formulation variables, for example, thenature of the components or their physiochemical environment. One of these variables is the presence of the type and concentration of the alcohol in the systems. The formulation scan varying the ethylene oxide number (EON) of the system were carried out, by means of the mixture of a lypophilic surfactant with another hydrophylic with the purpose of finding the maximum solubility system (Winsor III optimum) and to incorporate in this system the different alcohols with different concentrations to observe the transition change. The partititon coefficient was determined by high performance liquid cromatografic (HPLC). The addition of lineal lipophilics alcohols to these systems provides more polarity to the oil phase in consequence more fractionation towards it same one. It was found that if the alkyl chain of the co-surfactant is above an ACAN (alcohol atom carbon number) equal to 4,5 the 50 percent of fractionation is not affected by the increment of the concentration neither for the type of alcohol.

Use of pH studies to determine the kinetic and chemical mechanism of yeast alcohol dehydrogenase with primary aliphatic alcohols and aldehydes.

A complete list of all steady-state kinetic constants for the yeast alcohol dehydrogenase (EC 1.1.1.1) catalyzed oxidation of ethanol, propan-1-ol and butan-1-ol, and for the reduction of acetaldehyde and propionaldehyde was collected in the pH range 6-10, and an appropriate pH profile for each constant was constructed. A common minimal mechanism with all these substrates has been postulated and pKa values and the pH independent limiting values have been assigned for the rate constants.