Exploration on the construction of teaching team in universities under the background of "Double-First Class": taking medical cell biology as an example / 中华医学教育探索杂志

Medical cell biology is an important basic course of school medical education. Constructing a high-quality course teaching team is the key to improve the level and quality of education and teaching in universities under the background of "Double First-Class" at present. Based on the analysis of the current problems in the construction of teaching teams in universities, taking the teaching team of medical cell biology in Nanjing University of Chinese Medicine as an example, this paper elaborates the experience of team construction in terms of the composition of teaching staff, construction objectives, specific measures and practical results, so as to provide reference for further improving the construction of teaching teams in universities under the background of "Double First-Class".

Expression of LncRNA ARAP1-AS1 in pancreatic cancer and its influence on cell biology / 中华内分泌外科杂志

Objective:To detect the expression of long non-coding RNA (LncRNA) ARAP1-AS1 in pancreatic cancer, and to preliminarily explore its effects on the biological behaviors of proliferation, apoptosis, migration and invasion of pancreatic cancer cell.Methods:The pancreatic cancer tissue specimens and corresponding paracancerous tissue specimens of 25 patients were collected, and the expression of ARAP1-AS1 was detected by qPCR. Human pancreatic cancer cell line PANC-1 was cultured in vitro and divided into control group, siRNA-control group (transfected with siRNA control sequence), knockout group (transfected with ARAP1-AS1 siRNA), pcDNA3.1-control group (transfected with pcDNA3.1) and overexpression group (transfected with pcDNA3.1-ARAP1-AS1), qPCR method was used to detect the transfection efficiency, CCK-8 method was used to detect the cell proliferation ability, flow cytometry was used to detect the cell apoptosis, scratch test was used to detect the cell migration ability, Transwell method was used to detect the cell invasion ability, Western blot (WB) method was used to detect the expression of proliferating cell nuclear antigen (PCNA), B lymphoma-2 protein (Bcl-2), Bcl-2 related X protein (Bax), matrix metalloproteinase-9 (MMP-9) proteins.Results:The expression level of ARAP1-AS1 in pancreatic cancer tissues was significantly higher than that in adjacent tissues (2.26±0.13 vs 1.00±0.00) ( P<0.05). Compared with the siRNA-control group, the ARAP1-AS1 level (1.01±0.02 vs 0.29±0.03), PCNA, Bcl-2, MMP-9 protein levels, cell OD value (0.57±0.05 vs 0.23±0.03), scratch healing rate (78.53±7.02 vs 48.60±5.26), and number of invasions (229.63±22.59 vs 104.25±15.04) in PANC-1 cells of the knockout group were significantly reduced ( P<0.05), the Bax protein level and the apoptosis rate (4.52±0.42 vs 32.40±1.84) were significantly increased ( P<0.05). Compared with the pcDNA3.1-control group, the ARAP1-AS1 level (1.02±0.03 vs 2.06±0.08), PCNA, Bcl-2, MMP-9 protein levels, cell OD value (0.57±0.05 vs 0.90±0.08), scratch healing rate (77.65±6.67 vs 91.22±7.34), and number of invasions (225.34±19.65 vs 327.50±25.40) in PANC-1 cells of the overexpression group were significantly increased ( P<0.05), the Bax protein level and the apoptosis rate (4.58±0.48 vs 2.29±0.24) were significantly reduced ( P<0.05) . Conclusion:LncRNA ARAP1-AS1 is highly expressed in pancreatic cancer, which can promote the proliferation, migration and invasion of pancreatic cancer cells PANC-1, and reduce cell apoptosis.

El doctor Juan Noé y el nacimiento de la biología celular en Chile / Dr. Juan Noé and the birth of cell biology in Chile

Dr. Vicente Izquierdo San Fuentes was the first professor of Histology at the Faculty of Medicine of the University of Chile. In that Chair, cell theory strongly radiated to new generations of health students. However, the conditions for the creation of the discipline of General or Cell Biology were not yet ripe. Almost three decades later, Dr. Juan Noé Crevani was hired in Italy to lead Medical Zoology in 1912. From the heterogeneous discipline of Medical Zoology, Dr. Noé managed to create in 1926 the new chairs of General Biology, Embryology-Comparative Anatomy and Parasitology. His vision of biology as an essentially dynamic and experimental science, contributed to modernize and encourage the development of different areas of biology in Chile. Retaining their full independence, these chairs met in 1931, in a new organization called the Juan Noé Institute of Biology, which lasted until the university reform of 1968. Afterwards, the departments of Biology and Genetics, Parasitology, Human Anatomy and Histology were created. In 1998, a new reorganization of the Faculty of Medicine of the University of Chile began, creating the so-called Institute of Biomedical Sciences (ICBM) that houses several disciplinary programs that replaced the old departments.

Teaching design and practice of Stem Cell Biology course for graduate students / 中华医学教育探索杂志

The stem cell biology plays an important role in the application and research of the clinical medicine and biology. The breakthrough of the therapies for a variety of human diseases depends on the rapid growth of stem cell biology. It is of great significance to set up graduate curriculum of stem cell biology in the medical college. This article elaborates the design and implementation of the course of Stem Cell Biology including the selection of the teaching materials, design of course outline, teaching content, evaluation methods, teaching introspection and other aspects, thus providing references and communications in this field.

Morphometric characteristics of human skeletal muscle cells in primary culture / Características morfométricas de células musculares esqueléticas humanas en cultivo primario

SUMMARY: The study of cell morphology has contributed to the innovation of clinical techniques and biomedical research. Primary cell culture techniques are well standardized; however, knowledge about morphometric parameters under cell culture conditions is scarce. Variations in morphology can affect cell physiology and responses. The aim of this study was to use morphometric tools to describe the growth and development of skeletal muscle cells under standard cell culture conditions. A photographic database was generated, and morphometric data was obtained for nine cell characteristics (n = 559 cells). Four muscular cell shapes (spherical, irregular outline, triangular and spindle/fusiform) were characterized with wide ranges in variation. The maximum cell length (110-262 µm), width (35-66 µm), area (2,642 - 9,480 µm2), projection lengths (45 - 127 µm), and nucleus diameter (28 ± 11 µm) were obtained by day 23 of culture. A single centrally positioned nucleus was observed in each cell; nucleoli diameter (5 ± 2 µm) and number (1 - 5) varied. In general, cyclic changes in cell sizes were identified during culture, whereas cell length, width, and area increased in spurts. These results suggest that morphometric parameters can be used to monitor skeletal muscle cell development under standard culture conditions.

RESUMEN: A partir de células madre musculares, surgen los mioblastos que se dividen y fusionan entre sí para formar a los miocitos. Estas células ya diferenciadas son precursoras de miocitos que maduran en fibras musculares y posteriormente forman los músculos. La implementación de cultivos celulares de mioblastos ha permitido obtener conocimiento detallado del tejido muscular. Particularmente, algunas de las aportaciones morfológicas fueron el punto de partida de técnicas clínicas, terapias o investigaciones biomédicas. Sin embargo, los estudios morfométricos en condiciones de cultivo celular son escasos. Por lo cual, realizamos seguimientos fotográficos a cultivos desarrollados bajo condiciones estándar, registramos datos para nueve características celulares y aplicamos técnicas morfométricas para analizar estas células (n = 559). Se caracterizaron cuatro formas celulares adoptadas por los mioblastos (esférica, irregular, triangular y huso) y se registraron intervalos amplios de variación en los caracteres. Hacia el día 23 de cultivo se presentaron los valores máximos en la longitud (110-262 µm), el ancho (35-66 µm) y el área celular (2,642-9,480 µm2), así como en el tamaño máximo de las proyecciones celulares (45-127 µm) y el diámetro del núcleo (28±11 µm). El núcleo se observó como único y en posición central; los nucleolos variaron poco en diámetro (5±2 µm), aunque no en número (1 a 5). En términos generales, se identificaron cambios cíclicos en la talla de las células durante los cultivos, esto es, períodos intercalados de incremento y decremento en el largo, ancho y área celular. Debido a que estas características reflejaron los cambios generales sufridos por los mioblastos durante el cultivo, se proponen para monitorear sus etapas de desarrollo en cultivo.

Characterization of SH-SY5Y neurons subject to 92kHz ultrasound stimulation / Caracterización de neuronas SH-SY5Y sujetas a estimulación por ultrasonido de 92 kHz

SUMMARY: Cellular microstructural changes due to ultrasound exposure are critical to understand and characterize in order to further the establishment of ultrasonics in cell and tissue engineering and medicine. In this study, neurite length, nuclear morphology, and cellular toxicity are assessed at varying intensities of 92 kHz ultrasound provided by a piezoceramic disk element and incident upon SH- SY5Y neurons in vitro. Findings suggest that stimulation increases neurite length up to 2.73 fold tested at α = 0.05 in an intensity dependent manner. Additionally, stimulation causes a statistically significant (α = 0.05) decrease in nuclear area and less elongated nuclei, by 1.78 fold and 1.38 fold respectively, also in an intensity dependent manner. For maximum transducer surface intensities ranging from 0 to 39.11 W/cm2, the toxicity of 92 kHz ultrasound is assessed and a nontoxic range is determined using Caspase-3 and Annexin V staining, in addition to Calcium imaging via Calcein-AM staining. Intensities of up to 1.6 W/cm2 are found to be nontoxic for the cells under the parameters used in this study.

RESUMEN: Los cambios micro estructurales celulares debidos a la exposición a los ultrasonidos son fundamentales para comprender y caracterizar el establecimiento de los ultrasonidos en la ingeniería y la medicina de células y tejidos. En este estudio, la longitud de las neuritas, la morfología nuclear y la toxicidad celular se evalúan a intensidades variables de ultrasonido de 92 kHz proporcionado por un elemento de disco piezocerámico e incidente sobre las neuronas SH-SY5Y in vitro. Los resultados sugieren que la estimulación aumenta la longitud de las neuritas hasta 2,73 veces probada a α = 0,05 de una manera dependiente de la intensidad. Además, la estimulación provoca una disminución estadísticamente significativa (α = 0,05) en el área nuclear y núcleos menos alargados, en 1,78 veces y 1,38 veces, respectivamente y también de una manera dependiente de la intensidad. Para intensidades máximas de la superficie del transductor que oscilan entre 0 y 39,11 W / cm2, se evaluó la toxicidad del ultrasonido de 92 kHz y se determinó un rango no tóxico mediante tinción con Caspasa-3 y Anexina V, además de imágenes de calcio mediante tinción con Calceína-AM. Se encontró que las intensidades de hasta 1.6 W / cm2 no son tóxicas para las células bajo los parámetros usados en este estudio.

Hepatic mitochondria in diet-induced obese mice (stereology and molecular analysis) / Mitocondrias hepáticas en ratones obesos inducidos por la dieta (estereología y análisis molecular)

SUMMARY: The world population is going through an obesity epidemic that has severe consequences for the health system. This study focused on studying hepatic mitochondria in obese animals induced by a high-fat (HF) diet and used the model-based stereology in electron micrographs for the quantitative study. Besides, the gene expressions of molecular markers of mitochondrial biogenesis carnitine palmitoyltransferase 1a (Cpt 1α), mitochondrial transcription factor a (Tfam), uncoupling protein 3 (Ucp 3), and nuclear respiratory factor 1 (Nrf 1) were analyzed. The HF diet caused a weight gain of +1820 % comparing the control group (C) with the HF group (from 0.32±0.31 g to 5.5±0.39 g, P<0.001). The HF group showed fat droplets in the hepatocyte cytoplasm (steatosis) and less dense and large mitochondria in transmission electron microscopy. The mitochondria size (cross-section) did not show a significant difference between the groups C and HF. However, the mitochondria numerical density per area was 30 % less, the mitochondrial surface density (outer membrane) was 20 % less, and the mitochondrial volume density was 22 % less in the HF group than the C group. The gene expressions of molecular markers of mitochondrial biogenesis Cpt 1α, Tfam, Ucp 3, and Nrf 1 decreased in the HF group compared to the C group. The quantitative results match perfectly with the molecular ones of mitochondrial biogenesis markers. In the future, it will be crucial to verify if and how these data recover with the reduction of obesity, which would be of significant interest given the current obesity epidemic that affects the world population.

RESUMEN: La población mundial atraviesa una epidemia de obesidad que tiene graves consecuencias para el sistema de salud. Este estudio se centró en el análisis de las mitocondrias hepáticas en animales obesos inducidos por una dieta alta en grasas (HF) y utilizó la estereología basada en modelos en micrografías electrónicas para el estudio cuantitativo. Además, se analizaron las expresiones génicas de los marcadores moleculares de la biogénesis mitocondrial carnitina palmitoiltransferasa 1a (Cpt 1α), factor de transcripción mitocondrial a (Tfam), proteína desacoplante 3 (Ucp 3) y factor respiratorio nuclear 1 (Nrf 1). La dieta HF provocó un aumento de peso de +1820 % comparando el grupo de control (C) con el grupo HF (de 0,32 ± 0,31 g a 5,5 ± 0,39 g, P <0,001). El grupo HF mostró gotas de grasa en el citoplasma de los hepatocitos (esteatosis) y mitocondrias menos densas y grandes en la microscopía electrónica de transmisión. El tamaño de las mitocondrias (sección transversal) no mostró una diferencia significativa entre los grupos C y HF. Sin embargo, la densidad numérica de mitocondrias por área fue 30% menor, la densidad de superficie mitocondrial (membrana externa) fue 20 % menor y la densidad de volumen mitocondrial fue 22 % menor en el grupo HF que en el grupo C. Las expresiones génicas de los marcadores moleculares de la biogénesis mitocondrial Cpt 1α, Tfam, Ucp 3 y Nrf 1 disminuyeron en el grupo HF en comparación con el grupo C. Los resultados cuantitativos coinciden perfectamente con los moleculares de los marcadores de biogénesis mitocondrial. En el futuro, será crucial verificar si estos datos se recuperan y cómo se recuperan con la reducción de la obesidad, lo que sería de gran interés dada la actual epidemia de obesidad que afecta a la población mundial.

Effect of cellular immunotherapy combined with chemotherapy on apoptosis-related genes and immune function in patients with non-small cell lung cancer / 中国基层医药

Objective:To investigate the effect of immunotherapy with dendritic cells and cytokine-induced killer cells combined with chemotherapy on apoptosis-related genes and immune function in patients with middle- and advanced-stage non-small cell lung cancer.Methods:A total of 100 patients with middle- and advanced-stage non-small cell lung cancer who received treatment in Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, China from February 2018 to May 2019 were included in this study. They were randomly divided into control and observation groups ( n = 50/group). The two groups were given chemotherapy with pemetrexed and cisplatin. The observation group was given immunotherapy with dendritic cells and cytokine-induced killer cells based on chemotherapy with pemetrexed and cisplatin. Changes in apoptosis-related genes [primary autosomal recessive microcephaly gene (MCPH1), ataxia-telangiectasia mutated (ATM), ataxia telangiectasia mutated and Rad3 related (ATR), transcription factor 21 (TCF21)] and immune function were monitored. Clinical efficacy of immunotherapy with dendritic cells and cytokine-induced killer cells combined with chemotherapy with pemetrexed and cisplatin in the treatment middle-and advanced-stage non-small cell lung cancer was assessed. Results:After treatment, expression of MCPH1, ATM, ATR and TCF21 in the observation group was 301.11 ± 41.12, 239.98 ± 30.15, 270.01 ± 36.01, 270.01 ± 34.02, respectively, which was significantly higher than that in the control group [101.32 ± 15.32, 103.00 ± 13.97, 101.12 ± 14.90, 100.20 ± 14.99, t = 32.194, 29.149, 30.644, 32.299, all P < 0.001]. The proportion of the number of Th1-positive cells in the number of CD +4 T cells in the observation group was significantly higher than that in the control group [(29.00 ± 3.41)% vs. (22.61 ± 3.22)%, t = 9.634, P < 0.001]. The proportion of the number of Th17-,Th2 and CD +4CD +25Treg-positive cells in the number of CD +4 T cells in the observation group were (0.89 ± 0.10)%, (12.01 ± 1.36)%, (11.02 ± 1.92)%, respectively, which were significantly lower than those in the control group [(1.70 ± 0.20)%, (17.61 ± 2.20)%, (18.70 ± 2.40%)%, t = 25.614, 15.310, 17.670, all P < 0.001]. Total effective rate in the observation group was significantly higher than that in the control group [52.0% (26/50) vs. 30.0% (15/50), χ2 = 5.002, P < 0.05]. Conclusion:Immunotherapy with dendritic cells and cytokine-induced killer cells combined with chemotherapy with pemetrexed and cisplatin can induce apoptosis and regulate immune function. The combined therapy exhibits better clinical efficacy in the treatment of non-small cell lung than chemotherapy alone.

Effects of microRNA-26a targeted high-mobility group A2 protein antibody on the proliferation and migration of hepatoma cells / 中国基层医药

Objective:To investigate the effects of miRNA-26a (miR-26a) on the target gene HMGA2 on the proliferation and migration of hepatoma cells and the underlying mechanism. Methods:Liver cancer tissue samples ( n = 30) and adjacent normal tissue samples ( n = 30) pathologically confirmed by Wenzhou Hospital of Traditional Chinese Medicine between September 2018 and September 2019 were collected. MiR-26a mimics, control mimics (miR-Control), high-mobility group A2 protein (HMGA2) siRNA or negative control siRNA (Control) were transfected into human hepatoma cell lines HepG2 or Huh-7 cells. The expression of miR-26a in hepatocellular carcinoma tissue was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). MTT assay and scratch test were performed to determine the ability of cell proliferation and migration. RT-qPCR and western blotting were performed to detect miR-26a and HMGA2 mRNA expression. The relationship between miR-26a and HMGA2 mRNA was analyzed using Bioinformatics and luciferase reporter gene assay. Results:RT-qPCR results showed that the expression level of miR-26a in hepatocellular carcinoma tissue was 0.11 ± 0.02, which was significantly lower than that in normal tissues (0.25 ± 0.03, t = 21.268, P < 0.05). The expression level of miR-26a in stage III + IV was 0.05 ± 0.01, which was significantly lower than that in stage I + II (0.09 ± 0.01, t = 15.491, P < 0.05). Cell experiment showed that in the miR-26a group, the proliferation ability of Huh-7 cells was (3.10 ± 0.30) and (4.10 ± 0.40), and the proliferation ability of HepG2 cells was (3.08 ± 0.31) and (4.11 ± 0.40), which was significantly lower than that in the control group [(3.90 ± 0.40), (5.50 ± 0.60), (3.92 ± 0.41), (5.49 ± 0.58), t = 8.764, 10.634, 11.148, 10.728, all P < 0.05]. In the miR-26a group, the migration ability was (0.50 ± 0.06), (0.65 ± 0.07), which was significantly lower than that in the control group [(1.00 ± 0.10), (0.96 ± 0.10), t = 23.483, 13.910, both P < 0.05]. Bioinformatics and in vitro experiments showed that HMGA2 was a direct target of miR-26a. Restoring the expression of HMGA2 in miR-26a mimics-transfected cells, compared with that in the miR-26a group [(0.24 ± 0.02), (0.31 ± 0.03);(0.45 ± 0.05)], could significantly reverse the inhibitory effect of miR-26a on tumor cell proliferation and migration [(0.31 ± 0.03), (0.40 ± 0.04);(0.93 ± 0.08), t = 10.634, 9.859, 27.868, all P < 0.05). Conclusion:miR-26a inhibits the proliferation and migration of hepatoma cells by directly targeting HMGA2. The abnormal decrease of miR-26a and the increase of HMGA2 may be the important factors that participate in the occurrence and development of liver cancer.

Potential hepatotoxic compounds and mechanisms of Epimedii Folium based on network toxicology and cell experimental validation / 中国中药杂志

To probe the potential hepatotoxic components of Epimedii Folium and investigate its mechanism based on network toxicology and cell experimental validation. According to the previous results of component measurement and cytotoxicity evaluation, 11 active compounds related to hepatotoxicity in Epimedii Folium were chosen as research object in this study. Through SwissTargetPrediction database and GeneCards database, the potentially hepatotoxic targets of Epimedii Folium were obtained. Subsequently, the protein-target interaction network and active compounds-hepatotoxic targets network were established to analyze the core targets and screen the key hepatotoxic compounds in Epimedii Folium. Meanwhile, the signaling pathways and molecular mechanisms were inferred with GO functional enrichment analysis and KEGG pathway enrichment analysis on the core targets. At last, the effect of icaritin as the chief hepatotoxic compound on the indexes related to hepatotoxicity in HL-7702 cells and HepG2 cells was investigated to validate the hepatotoxicity mechanism of Epimedii Folium. Through the network toxicology analysis, 190 action targets and 991 hepatotoxic targets were collected, then 64 potentially hepatotoxic targets of Epimedii Folium including AKT1, EGFR, MAPK3, TNF and so on were obtained, and icaritin was screened as the key hepatotoxic compound. GO functional enrichment analysis indicated 160 biological process terms such as protein phosphorylation and negative regulation of apoptotic process, 41 molecular function terms such as protein binding and ATP binding, and 32 cellular component terms such as cytosol and cell surface. KEGG pathway enrichment analysis inferred 75 signaling pathways involving PI3 K-Akt and HIF-1. After comprehensive analysis, it was inferred that the hepatotoxicity mechanism of Epimedii Folium was related with regulating oxidative stress and apoptosis. The results of cell biology experiments showed that icaritin could significantly increase the level of aspartate aminotransferase and lactate dehydrogenase, reduce the level of glutathione, improve the quality of reactive oxygen species and reduce mitochondrial membrane potential, indicating that it could cause hepatotoxicity by destroying cell membrane structure, inhibiting antioxidant enzyme activity, activating oxidative stress and inducing apoptosis. These results proved the reliability of results of network pharmacology. This study preliminarily clarified the material base and the mechanism of potential hepatotoxicity of Epimedii Folium, which provided important information for further research and safe application.

Analysis of permeability and biological properties of dentin treated with experimental bioactive glasses / Análise da permeabilidade e propriedades biológicas da dentina tratada com vidros bioativos experimentais

O objetivo deste estudo foi avaliar a capacidade obliteradora de diferentes agentes dessensibilizantes em dentina humana através da mensuração da permeabilidade dentinária, e suas performances biológicas através da análise de citotoxicidade em fibroblastos gengivais humanos. Cinquenta molares humanos foram utilizados, dos quais foram obtidos blocos de dentina (4x4x1mm) posteriormente distribuídos em grupos de acordo com o dessensibilizante a ser utilizado (n=10): Grupo 1 - Controle (Saliva artificial. Sem aplicação de agente dessensibilizante); Grupo 2 - Ultra EZ (Ultradent); Grupo 3 - Desensibilize Nano P (FGM); Grupo 4 - Vidro Bioativo T5-OH (solução experimental); Grupo 5 - Vidro Bioativo F18 (solução experimental). Os tratamentos dessensibilizantes foram realizados durante 15 dias. Além disso, os espécimes foram submetidos ao desafio com ácido cítrico para simular condições desmineralizantes do ambiente oral. As amostras foram submetidas à análise de permeabilidade antes e após os procedimentos dessensibilizantes e o desafio ácido. Análise de citotoxicidade foi realizada pelo ensaio Alamar Blue complementado pela quantificação de proteína pelo Método BCA (ácido bicinconínico) (N=3; n=3) nos tempos de avaliação de 15 minutos, 24 horas e 48 horas. Microscopia eletrônica de varredura (MEV) e Espectroscopia de Raio-X por Energia Dispersiva (EDS) foram realizadas para análise qualitativa da dentina tratada. Dados de permeabilidade dentinária foram analisados por ANOVA dois fatores medidas repetidas e Teste de Tukey (α=0,05). Para a citotoxicidade, foram utilizados os testes Kruskal-Wallis e Newman-Keuls (α=0,05). Os resultados mostraram que para a permeabilidade dentinária não houve diferença significante entre os agentes dessensibilizantes após os tratamentos (p> 0,05), porém o grupo controle apresentou os maiores valores (0,131 ± 0,076 Lp, p< 0,05). Após o desafio ácido, o grupo controle manteve os maiores valores (0,044 ± 0,014 Lp) com diferença significante para os demais grupos (p< 0,05), exceto para o Desensibilize Nano P (0,037 ± 0,019 Lp). Quanto à citotoxicidade, não houve diferença entre os grupos experimentais (p> 0,05). Assim, foi possível concluir que o uso de dessensibilizantes à base de biovidros causou efeito similar ao uso de produtos disponíveis comercialmente, em relação à permeabilidade e propriedades biológicas da dentina(AU)

The aim of this study was to evaluate the obliterating capability of different desensitizing agents on human dentin by measuring dentin permeability, and their biological performance by the analysis of cytotoxicity in human gingival fibroblasts. Fifty human molars were used, from which dentin blocks were obtained (4x4x1mm) and distributed in groups according to the desensitizing agent used (n=10): Group 1 - Control (Artificial saliva. No desensitizing agent applied); Group 2 ­ Ultra EZ (Ultradent); Group 3 ­ Desensibilize Nano P (FGM); Group 4 - T5-OH Bioactive Glass (Experimental solution); Group 5 - F18 Bioactive Glass (Experimental solution). The desensitizing treatments were performed for 15 days. In addition, the specimens were subjected to challenge with citric acid to simulate oral environment demineralizing conditions. Samples were subjected to permeability analysis before and after the desensitizing procedures and the acid challenge. Cytotoxicity analysis was performed by using Alamar Blue assay and complemented by total protein quantification by Pierce Bicinchoninic Acid (BCA) assay (N=3; n=3) at 15 minutes, 24-hour and 48-hour time points. Scanning electron microscopy (SEM) and energy dispersion X-ray spectroscopy (EDS) were performed for qualitative analysis of treated dentin. Data of dentin permeability was analyzed by twoway repeated measures ANOVA and Tukey's post-hoc test (α=0.05). For cytotoxicity, Kruskal-Wallis and Newman-Keuls tests were used (α=0.05). The results showed that for dentin permeability there was no significant difference among the desensitizing agents after treatment (p> 0.05), but the control group presented the highest values (0.131 ± 0.076 Lp, p< 0.05). And after acid challenge, the control group maintained the highest values (0.044 ± 0.014 Lp) with significant difference to the other groups (p< 0.05), except for Desensibilize Nano P (0.037 ± 0.019 Lp). For cytotoxicity, there were no significant differences among the experimental groups (p> 0.05). It was concluded that the use of bioglass-based desensitizers caused similar effects to commercially available products, regarding permeability and dentin biological properties(AU)

Do medicine and cell biology talk to each other? A study of vocabulary similarities between fields

A close interaction between basic science and applied medicine is to be expected. Therefore, it is important to measure how far apart the field of cell biology and medicine are. Our approach to estimating the distance between these fields was to compare their vocabularies and to quantify the difference in word repertoire. We compared the vocabulary of the title and abstract of articles available in PubMed in two selected high-impact journals in each field: cell biology, medicine, and translational science. Although each journal has its own editorial policy, we showed that within each field there is a small vocabulary difference between the two journals. We developed a word similarity index that can measure how much journals share a common vocabulary. We found a high similarity index between each cell biology (91%), medical (71-74%), and translational journal (65%). In contrast, the comparison between medicine and biology journals produced low correlation values (22-36%), suggesting that their vocabularies are quite dissimilar. Translational medicine journals had medium similarity values when compared to cell biology journals (52-70%) and medicine journals (27-59%). This approach was also performed in 10-year periods to evaluate the evolution of each field. Using the "onomics" strategy presented here, we observed that differences in vocabulary of basic science and medicine have been increasing over time. Since translational medicine has an intermediate vocabulary, we confirmed that translational medicine is an efficient approach to bridge this gap.

Prueba diagnóstica entre la citología, biopsia por congelación e histopatología en el diagnóstico del Nódulo Tiroideo en pacientes atendidos en Solca desde el año 2009 ­2017 / Diagnostic Test between cytology, frozen biopsy and histopathology in the diagnosisof the thyroid nodule in patients treated at Solca from 2009 -2017

Introducción: La citología de nódulos tiroideos es una técnica que, evita procedimientos quirúrgicos innecesarios por lo que se lo ha determinado como primera línea dentro del algoritmo de diagnóstico, el objetivo del estudio fue determinar la sensibilidad y la especificidad de la citología y biopsia por congelación frente al estudio histopatológico en el diagnóstico de nódulos tiroideos en pacientes atendidos en Solca desde el año 2009 -2017. Métodos: Es un estudio de tipo observacional, retrospectivo y de correlación diagnóstica; los datos fueron obtenidos de las historias clínicas de pacientes intervenidos quirúrgicamente por nódulos tiroideos con biopsia por congelación, a quienes se les realizó previamente un estudio citológico en el Departamento de patología de SOLCA de la ciudad de Cuenca, Ecuador. El cálculo del tamaño de la muestra fue de 324 casos. Resultados:324 casos fueron incluidos. El 8.3% correspondió a hombres y el 91.7% a mujeres. La media de la edad fue 51.8 años; la gran mayoría provenían de la provincia Azuay con el 64.8%. En los estudios citológicos el 34.6% (112 casos)corresponden a lesiones inflamatorias benignas; el 11.1% [36 casos]a patologías malignas y 14.2% (46 casos)fueron insatisfactorios. En la biopsia por congelación el mayor porcentaje estuvo concentrado en enfermedades benignas con un 62.6% y 35.5% a lesiones malignas. Hubo 6 casos con el 1.9% en donde fue diferido el criterio diagnóstico. En el histopatológico definitivo el 60.2% (195 casos)fueron patologías benignas y el 39.8% (129 casos)fueron lesiones malignas. La sensibilidad de la PAAF frente a histopatológico es alta con un 91.79%, pero la especificidad es baja con un 51.94%. La sensibilidad y la especificidad de la biopsia por congelación frente a histopatológico es alta con un 98.97% y 90.70% respectivamente lo que le confiere una metodología óptima. Conclusiones: La PAAF de tiroides demuestra ser una metodología útil en el diagnóstico de nódulos, siempre y cuando sea realizada y observada por personal capacitado. La biopsia por congelación constituye una técnica con alta sensibilidad y especificidad que nos permite discriminar lesiones benignas de las malignas. Palabras claves: Nódulo tiroideo, Biopsia con Aguja, Servicio de Patología en Hospital, Oncología Médica, Agencias Voluntarias de Salud, Biología Celular, Biopsia con Aguja Fina

Introduction:Cytology of thyroid nodules is a technique that avoids unnecessary surgical procedures and has therefore been determined as the first line within the diagnostic algorithm.General Objective:To determine the sensitivity and specificity of cytology and freezing biopsy versus histopathological study in the diagnosis of thyroid nodules in patients treated in Solca since 2009 -2017. Methods:This is an observational, retrospective and diagnostic correlation study; the data were obtained from the clinical histories of patients surgically treated by thyroid nodules with freeze biopsy, who underwent a cytological study in the Department of pathology of the city of Cuenca, Ecuador. The calculation of the sample size was 324 cases. Results:8.3% corresponded to men and 91.7% to women. The mean age was 51.8 years; The vast majority came from the province of Azuay with 64.8%. In cytological studies, 34.6% [112 cases]correspond to benign inflammatory lesions; 11.1% [36 cases]to malignant pathologies and 14.2% [46 cases]were unsatisfactory. In the freeze biopsy the greater percentage was concentrated in benign diseases with 62.6% and 35.5% to malignant lesions. There were 6 cases with 1.9% where the diagnostic criterion was deferred. In the definitive histopathological, 60.2% [195 cases]were benign pathologies and 39.8% [129 cases]were malignant lesions. The sensitivity of FNAB to histopathological is high with 91.79%, but the specificity is low with 51.94%. The sensitivity and specificity of freezing versus histopathological biopsy is high with 98.97% and 90.70% respectively, which gives it an optimal methodology. Conclusions: Thyroid PAAF proves to be a useful methodology in the diagnosis of nodules, as long as it is performed and observed by trained personnel. Freezing biopsy is a technique with high sensitivity and specificity that allows us to discriminate benign from malignant lesions. Key words:Thyroid Nodule; Biopsy, Needle;Pathology Department, Hospital; Medical Oncology; Voluntary Health Agencies; Cell Biology; Biopsy, Fine-Needle

Los métodos de estudio anatomopatológicos desde una mirada histórica, social y contextualizada / Pathological study methods from a historical, social and contextualized perspective

RESUMEN El surgimiento y desarrollo de los métodos de estudio anatomopatológicos guarda una estrecha relación con el desarrollo científico- técnico alcanzado por la sociedad. Los métodos tradicionales empleados para el estudio anatomopatológico de las enfermedades se han enriquecido con las nuevas tecnologías, lo que ha favorecido su conocimiento más profundo, en particular el de las neoplasias, una de las primeras causas de muerte en Cuba y en el mundo. En el presente trabajo se hace una panorámica sobre el desarrollo histórico de estos diferentes métodos y su impacto en los procesos de asistencia y educación médica. Se hace una reflexión sobre la necesidad de fortalecer la formación para el uso adecuado del método clínico y para la indicación justificada e interpretación acertada de los resultados de los exámenes que, de manera tradicional, han hecho posible el diagnóstico y la valoración del pronóstico y la terapéutica, evitando de esta manera el uso irracional de otras tecnologías que encarecen la asistencia médica.

ABSTRACT The emergence and development of pathological study methods is closely related to the scientific-technical development achieved by society. The traditional methods used for the pathological study of diseases have been enriched with new technologies, which has favored their deepest knowledge, particularly that of neoplasms, one of the leading causes of death in Cuba and in the world. In this paper, an overview is made of the historical development of the different anatomopathological study methods and their impact on the processes of medical assistance and education. A reflection is made on the need to strengthen training for the proper use of the clinical method and for the justified indication and correct interpretation of the results of the examinations that, in a traditional way, have made possible the diagnosis and the assessment of the prognosis and the therapeutic, thus avoiding the irrational use of other technologies that make medical care more expensive.

Bacterial vaginosis: prevalence, risk profile and association with sexually transmitted infections / Vaginose bacteriana: prevalência, perfil de risco e associação com infecções sexualmente transmissíveis / Vaginosis bacteriana: prevalencia, perfil de riesgo y asociación con infecciones de transmisión sexual

Background and Objectives: Bacterial vaginosis (BV) is the most common cause of vaginal discharge in the world. The study aimed to estimate the prevalence and to identify risk factors associated with bacterial vaginosis. Methods: A cross-sectional study was conducted in Ouro Preto, Brazil, between February and December 2017. Three hundred and forty-one women aged 18 years or older, users of the Brazilian Unified Health System, participated in this study. Women who used oral or topical antibiotics in the four weeks prior to the sample collection and women who had undergone a total hysterectomy were excluded from the study. After signing the Informed Consent Form and filling out a questionnaire containing sociodemographic, behavioral and sexual data, the participants were directed to the collection room, where the nurse collected the samples for the preventive examination of the cervix and also two vaginal swabs. Vaginal swabs and cervical samples were analyzed for cytological abnormalities and BV using Gram staining and cytology. Pathogens causing sexually transmitted infections (STIs) were identified by Polymerase Chain Reaction (PCR). For the analysis of the data, statistical package STATA version 10.0 was used. This study was approved by the Research Ethics Committee of the Federal University of Ouro Preto (UFOP). Results: During the study, 341 women were evaluated. The prevalence of BV using Gram staining (32.5% [CI95% 27.7-37.7%]) and cytology (27.7% [CI95% 23.032.8%]) was similar, however, the sensitivity of cytology was lower (77.8%). Risk factors associated with BV were smoking (IRR 1.5 [CI95%: 1.1  2.1]), use of an intrauterine device (IRR 2.8 [CI95%: 1.2 - 6.5]), and past medical history of BV (IRR 1.5 [CI95%: 1.1 - 2.1]). Correlation between the presence of BV and Trichomonas vaginalis (TV) infection (r=0.24) was observed. Conclusion: The prevalence of BV was affected by life habits and was prevalent in women with TV. Thus, behavioral and social prevention approaches to women with diverse risk profiles may help mitigate TV/BV prevalence and recurrence of BV.(AU)

Contexte et objectifs: La vaginose bactérienne (VB) est la cause la plus fréquente de pertes vaginales dans le monde. Le but de cette étude était d'évaluer la prévalence et les facteurs associés à la vaginose bactérienne. Méthodes: Il s'agit d'une approche descriptive, transversale et quantitative réalisée à Ouro Preto, Minas Gerais, Brésil, entre février et décembre 2017. 341 femmes ont participé à cette étude, âgées de 18 ans ou plus, utilisatrices du Système de santé unifié. Les femmes ayant utilisé des antibiotiques oraux ou topiques dans les quatre semaines précédant le prélèvement et les femmes ayant subi une hystérectomie totale ont été exclues de l'étude. Après avoir signé le formulaire de consentement éclairé et rempli un questionnaire contenant des données sociodémographiques, comportementales et sexuelles, les participants ont été dirigés vers la salle de collecte, où l'infirmière a prélevé les échantillons pour l'examen préventif du col de l'utérus. et aussi deux écouvillons vaginaux. Les échantillons de frottis vaginaux et cervicaux ont été analysés pour les anomalies cytologiques et VB en utilisant la coloration de Gram et la cytologie. Les agents pathogènes causant des infections sexuellement transmissibles (IST) ont été identifiés par réaction en chaîne par polymérase. Pour l'analyse des données, le progiciel statistique STATA version 10.0 a été utilisé. Cette étude a été approuvée par le Comité d'éthique de la recherche de l'Université fédérale d'Ouro Preto (UFOP). Résultats: Au cours de l'étude, 341 femmes ont été évaluées. La prévalence de la VB avec coloration de Gram (32,5% [IC 95% 27,7 - 37,7%]) et de la cytologie (27,7% [IC 95% 23,0 - 32,8%]) était similaire, cependant la sensibilité cytologique était plus faible (77,8%). Les facteurs de risque associés à la VB étaient le tabagisme (IRR 1,5 [IC 95%: 1,1 - 2,1]), l'utilisation d'un dispositif intra-utérin (IRR 2,8 [IC 95%: 1,2 - 6,5] ) et antécédents médicaux de VB (IRR 1,5 [IC 95%: 1,1 - 2,1]). Il y avait une corrélation entre la présence d'une infection à VB et Trichomonas vaginalis (TV) (r = 0,24). Conclusion: La prévalence de la VB était affectée par le mode de vie et l'infection TV. Ainsi, les approches de prévention comportementale et sociale pour les femmes présentant des profils de risque différents peuvent aider à atténuer la prévalence de la TV / VB et la récurrence de la VB.(AU)

Justificativa e Objetivos: A vaginose bacteriana (VB) é a causa mais comum de corrimento vaginal no mundo. O objetivo desse estudo foi avaliar a prevalência e os fatores associados à vaginose bacteriana. Métodos: Trata-se de um descritivo, de forma transversal e abordagem quantitativa realizado em Ouro Preto, Minas Gerais, Brasil, entre fevereiro a dezembro de 2017. Participaram desse estudo 341 mulheres com idade igual ou superior a 18 anos, usuárias do Sistema Único de Saúde (SUS). Mulheres que usaram antibióticos orais ou tópicos nas quatro semanas anteriores à coleta e mulheres que haviam sido submetidas a uma histerectomia total foram excluídas do estudo. Após a assinatura do Termo de Consentimento Livre e Esclarecido e preenchimento de questionário contendo dados sócio-demográfico, comportamental e sexual, as participantes foram encaminhadas para a sala de coleta, onde a enfermeira realizou a coleta das amostras para o exame preventivo do colo do útero e também de dois swabs vaginais. As amostras de esfregaço vaginal e cervical foram analisadas quanto às anormalidades citológicas e VB usando coloração de Gram e citologia. Patógenos causadores de infecções sexualmente transmissíveis (ISTs) foram identificados por Reação em Cadeia da Polimerase (PCR). Para a análise dos dados foi utilizado o pacote estatístico STATA versão 10.0. O presente estudo foi aprovado pelo Comitê de Ética em Pesquisa da Universidade Federal de Ouro Preto (UFOP). Resultados: Durante o estudo, 341 mulheres foram avaliadas. A prevalência de VB com coloração de Gram (32,5% [IC95% 27,7 - 37,7%]) e citologia (27,7% [IC95% 23,0 - 32,8%]) foi semelhante, porém a sensibilidade da citologia foi menor (77,8%). Os fatores de risco associados ao VB foram tabagismo (IRR 1,5 [IC95%: 1,1 - 2,1]), uso de dispositivo intrauterino (IRR 2,8 [IC 95%: 1,2 - 6,5]) e história médica pregressa de VB (IRR 1,5 [IC95%: 1,1 - 2.1]). Observou-se correlação entre a presença de infecção por VB e Trichomonas vaginalis (TV) (r = 0,24). Conclusão: A prevalência de VB foi afetada por hábitos de vida e infecção por TV. Assim, abordagens de prevenção comportamental e social para mulheres com diversos perfis de risco podem ajudar a mitigar a prevalência de TV / VB e recorrência de VB.(AU)

El arribo de la teoría celular a Chile: Dr. Vicente Izquierdo Sanfuentes / Dr. Vicente Izquierdo Sanfuentes and the arrival of the cellular theory in Chile

Vicente Izquierdo Sanfuentes was a leading physician, researcher and academic of the School of Medicine of the University of Chile in the period 1881-1912. Dr. Izquierdo began his medical training at the Faculty of Medicine of the University of Chile (1872-1875) and then received a scholarship to continue his studies with the prominent researchers Wilhelm Hiss (1875-1877) at the University of Leipzig and Wilhelm Waldeyer at the University of Strasbourg (1877-1879) in Germany. After returning to Chile, he was appointed first professor of Histology (1881), initiating the first course of this subject in 1883. His main academic achievements and his foundational role in the origin and development of biology in Chile stand out in his work.

T cell costimulation, checkpoint inhibitors and anti-tumor therapy

The hallmarks of the adaptive immune response are specificity and memory. The cellular response is mediatedby T cells which express cell surface T cell receptors (TCRs) that recognize peptide antigens in complex withmajor histocompatibility complex (MHC) molecules on antigen presenting cells (APCs). However, binding ofcognate TCRs with MHC-peptide complexes alone (signal 1) does not trigger optimal T cell activation. Inaddition to signal 1, the binding of positive and negative costimulatory receptors to their ligands modulates Tcell activation. This complex signaling network prevents aberrant activation of T cells. CD28 is the mainpositive costimulatory receptor on naı¨ve T cells; upon activation, CTLA4 is induced but reduces T cellactivation. Further studies led to the identification of additional negative costimulatory receptors known ascheckpoints, e.g. PD1. This review chronicles the basic studies in T cell costimulation that led to the discoveryof checkpoint inhibitors, i.e. antibodies to negative costimulatory receptors (e.g. CTLA4 and PD1) whichreduce tumor growth. This discovery has been recognized with the award of the 2018 Nobel prize in Physiology/Medicine. This review highlights the structural and functional roles of costimulatory receptors, themechanisms by which checkpoint inhibitors work, the challenges encountered and future prospects.

Commentary on mitochondrial stereology in transmission electron microscopy / Comentario sobre estereología mitocondrial en microscopía electrónica de transmisión

Mitochondria (m) are responsible for the energy availability of cells, and their analysis is indicated for example, in studies related to metabolism and oxidative stress. The direct measurement of mitochondria (morphometry) is biased because of the section obliquity and position relative to the mitochondria length (non-equatorial cut). Therefore, stereology is an appropriate technique to evaluate mitochondria. However, before beginning the study, it is necessary to consider the premises to obtain random and uniform samples to be analyzed stereology. Mitochondria must have the chance to appear in all the possibilities of cut and orientation in the micrographs. The number of micrographs to be analyzed will depend on the distribution and occupation of mitochondria in the cell. After this is resolved, a proposal is the estimation of the following stereological data: volume density (Vv), surface density (Sv), and mean cross-sectional area (A). Overlapping a known test area at each micrograph, the density by area of mitochondria is estimated (NAT). Vv [m] can easily be estimated by point-counting (Vv = Pp/PT; Pp are the points hitting the structure, PT are the number of points of the test system). Sv is estimated overlaying a test-line (LT) on the micrographs and counting the intersections of the lines (I) with the outer membrane (om), inner membrane (im), and crests (c), thus, Sv [om], Sv [im], Sv [c] (Sv = 2I / LT). A [m] is obtained as the ratio: A = Vv / 2NAT.

Las mitocondrias (m) son responsables de la disponibilidad de energía de las células, y su análisis está indicado, por ejemplo, en estudios relacionados con el metabolismo y el estrés oxidativo. La medición directa de las mitocondrias (morfometría) está sesgada debido a la oblicuidad de la sección y la posición relativa a la longitud de las mitocondrias (corte no ecuatorial). Por lo tanto, la estereología es una técnica apropiada para evaluar las mitocondrias. Sin embargo, antes de comenzar el estudio, es necesario considerar las premisas para obtener muestras aleatorias y uniformes para analizar estereológicamente. Es esencial que las mitocondrias tengan la posibilidad de aparecer en todas las posibilidades de corte y orientación en las micrografías. El número de micrografías que se analizarán dependerá de la distribución y ocupación de las mitocondrias en la célula. Una vez resuelto esto, una propuesta es la estimación de los siguientes datos estereológicos: densidad de volumen (Vv), densidad de superficie (Sv) y área de sección transversal media (A). Superponiendo un área de prueba conocida en cada micrografía, se estima la densidad por área de mitocondrias (NAT). Vv [m] se puede estimar fácilmente contando puntos (Vv = Pp / PT; Pp son los puntos que llegan a la estructura, PT son el número de puntos del sistema de prueba). Sv se estima superponiendo una línea de prueba (LT) en las micrografías y contando las intersecciones de las líneas (I) con la membrana externa (om), la membrana interna (im) y las crestas (c), por lo tanto, Sv [om], Sv [im], Sv [c] (Sv = 2I / LT). A [m] se obtiene como la relación: A = Vv / 2NAT.

Pancreatic islet stereology: estimation of beta cells mass / Estereología de los islotes pancreáticos: estimación de la masa de células beta

Obesity and its comorbidities are becoming epidemic in the Western world. Beta cell mass estimation is an important indicator to track the progression of insulin resistance/type 2 diabetes, particularly in experimental studies, where it can be performed with stereological tools in an unbiased way. In this work, we present a simple protocol that can contribute to doing the practice of estimating the mass of beta cells more frequent and reproducible. As with any quantitative study, the necessary precautions regarding sampling and randomness must be respected.

La obesidad y sus comorbilidades se están convirtiendo en una epidemia en el mundo occidental. La estimación de la masa de células beta es un indicador importante para rastrear la progresión de la resistencia a la insulina/diabetes tipo 2, particularmente en estudios experimentales, donde se puede realizar con herramientas estereológicas de manera imparcial. En este trabajo presentamos un protocolo simple que puede contribuir a que la práctica de estimar la masa de células beta sea más frecuente y reproducible. Como en cualquier estudio cuantitativo, deben respetarse las precauciones necesarias con respecto al muestreo y la aleatoriedad.

Comparative evaluation of the quality of Papanicolaou staining at different intervals of fixation times using 96% ethyl alcohol / Avaliação comparativa da qualidade da coloração de Papanicolaou em diferentes tempos de fixação em álcool etílico a 96%

ABSTRACT Introduction: Fixation of cytological smears consists of immediate immersion in appropriate fixative, in order to preserve cellular morphological characteristics, it is essential for the microscopic examination and diagnostic interpretation. Objective: To evaluate the influence of fixation times on the morphological and staining characteristics of samples fixed in ethanol and stained by the Papanicolaou method. Method: Experimental, quantitative and qualitative research was carried out on 99 samples of the jugal mucosa scrapings from 33 participants, fixed in 96% ethyl alcohol in three different times. Group A: 15 minutes; group B: 30 minutes; group C: seven days. The quality of staining was categorized in Optimal, Good, Regular and Poor, with subsequent recategorization at optimal and non-optimal. To verify the association among the groups and the categories, Fisher's exact test was performed, with significance level of 0.05. Results: From the 99 stained slides, 19 were discarded due to acellularity, remaining 80 slides. From these, 28 in group A, 26 in group B and 26 in group C were evaluated. In Group A, optimal quality was found in 60.7% (n = 17), good in 28.6% (n = 8), regular in 10.7% (n = 3) and poor in 0% (n = 0). In group B optimal was found in 61.5% (n = 16), good in 30.8% (n = 8), regular in 7.7% (n = 2) and poor in 0% (n = 0). In group C, optimal was found in 92.3% (n = 24), good in 7.7% (n = 2), regular in 0% (n = 0) and poor in 0% (n = 0). In the three groups, there was no representation of the Poor category. Conclusion: The results suggest that there is a significant difference in the staining quality (p-value = 0.01) according to the fixation time.

RESUMEN Introducción: La fijación de extensiones citológicas consiste en la inmersión inmediata en fijador adecuado para preservar la morfología celular, siendo esencial para el análisis microscópico y la interpretación diagnóstica. Objetivo: Evaluar la influencia de los tiempos de fijación en las características morfológicasy de tinción de muestras fijadas con metanoly tenidas con el método de Papanicolaou. Método: Se realizó una investigación experimental, cuantitativa y cualitativa de 99 muestras de raspado de la mucosa yugal de 33 participantes, fijadas con etanol al 96% en tres tiempos distintos. Grupo A: 15 minutos; grupo B: 30 minutos; grupo C: 7 días. La calidad de la tinción fue categorizada en óptima, buena, regular y mala, con posterior reclasificación en óptima y no óptima. Para determinar la asociación entre los grupos y las categorias, se realizó la prueba exacta de Fisher, con un nivel de significación del 0,05. Resultado: De las 99 muestras tenidas, 19 fueron desechadas por acelularidad, quedando 80 para ser analizadas. De estas muestras, 28 fueron evaluadas en el grupo A, 26 en el grupo B y 26 en el grupo C. En el grupo A, hemos encontrado calidad óptima - 60,7% (n =17); buena - 28,6% (n = 8); regular -10,7% (n = 3) y mala - 0% (n = 0). En el grupo B, óptima - 61,5% (n = 16); buena - 30,8% (n = 8); regular - 7,7% (n = 2); y mala - 0% (n = 0). En el grupo C, óptima - 92,3% (n = 24); buena - 7,7% (n = 2); regular - 0% (n = 0) y mala - 0% (n = 0). En los tres grupos no hubo representación en la categoria mala. Conclusión: Los resultados sugieren que hay diferencia significativa en la calidad de la tinción (p = 0,01) de acuerdo con el tiempo de fijación.

RESUMO Introdução: A fixação dos esfregaços citológicos consiste na imersão imediata em fixador adequado para preservar as características morfológicas celulares, sendo essencial para a análise microscópica e a interpretação diagnóstica. Objetivo: Avaliar a influência dos tempos de fixação nas características morfológicas e tintoriais de amostras fixadas em álcool etílico e coradas pelo método de Papanicolaou. Método: Realizou-se pesquisa experimental, quantitativa e qualitativa de 99 amostras de raspado da mucosa jugal de 33participantes, fixadas em álcool etílico 96% em três tempos diferentes. Grupo A: 15 minutos; grupo B: 30 minutos; grupo C: sete dias. A qualidade da coloração foi categorizada em ótima, boa, regular e ruim, com posterior recategorização em ótimo e não ótimo. Para verificar a associação entre os grupos e as categorias, realizou-se teste exato de Fisher, com nível de significância de 0,05. Resultado: Das 99 lâminas coradas, 19 foram desprezadas por acelularidade, restando 80 lâminas para serem analisadas. Destas, foram avaliadas 28 no grupo A, 26 no grupo B e 26 no grupo C. No grupo A, foi encontrada qualidade ótima - 60,7% (n = 17); boa - 28,6% (n = 8); regular - 10,7% (n = 3) e ruim - 0% (n = 0). No grupo B, ótima - 61,5% (n = 16); boa - 30,8% (n = 8); regular - 7,7% (n = 2); e ruim - 0% (n = 0). E no Grupo C, ótima - 92,3% (n = 24); boa - 7,7% (n = 2); regular - 0% (n = 0); e ruim - 0% (n = 0). Nos três grupos não houve representação na categoria ruim. Conclusão: Os resultados sugerem que há diferença significativa na qualidade da coloração (p = 0,01) de acordo com o tempo de fixação.