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Braz. j. oral sci ; 21: e225757, jan.-dez. 2022. ilus
Article in English | LILACS, BBO | ID: biblio-1366215


Aim: This study aimed to evaluate the effect of frozen storage on the physical properties of a silicone-based test food material, highly used to evaluate the masticatory performance in research settings. Methods: A total of 1,666 silicone cubes of Optosil Comfort® with 5.6-mm edges were shaped and stored at -18°C. The cubes were subsequently tested for flexural strength (maximum force, displacement, stress, and strain) before breaking (n = 136), changes in weight and size (n = 170), and masticatory performance (n = 1360) at eight timepoints: immediately after cube preparation (baseline, no freezing), and 1, 2, 3 and 4 weeks, and 2, 4 and 6 months after frozen storage. The cubes were thawed 8 h before each assessment. Results: The maximum force, stress, maximum displacement, and deformation values for the cubes were not affected by freezing (P > 0.05). At all of the time points, the cubes exhibited similar weight (P = 0.366) and size (identical values). The masticatory performance for the cubes also showed no differences from baseline through 6 months (P = 0.061). Conclusion: Freezing Optosil Comfort® silicone cubes did not alter the physical and mechanical properties of the material, being suitable to optimize the assessment of masticatory parameters for research purposes

Humans , Male , Adult , Silicone Elastomers , Materials Testing/methods , Physical Properties , Freezing , Flexural Strength , Mastication , Time Factors
Prensa méd. argent ; 107(4): 219-230, 20210000. tab, graf
Article in Spanish | LILACS, BINACIS | ID: biblio-1359445


Antecedentes: el tratamiento del CBC con menor tasa de recurrencia es el quirúrgico. Debido a la ausencia de lesión residual en cirugía de ampliación de márgenes y la utilidad de la congelación intraoperatoria se propuso analizar la utilidad de las retomas intraoperatorias. Objetivo: analizar el impacto de las retomas intraoperatorias en los resultados oncológicos y cosméticos de los pacientes operados de CBC. Secundariamente analizar la extensión subclínica, el valor de la congelación intraoperatoria y las tácticas reconstructivas empleadas. Lugar de aplicación: Hospital de atención terciaria de tumores. Material y métodos: trabajo observacional retrospectivo. Se incluyeron 84 resecciones durante 3 años y se realizó un análisis comparativo en términos de recurrencia, defecto quirúrgico y utilización de colgajos entre tumores sin retoma vs con retoma. Resultados: no hubo diferencias significativas en cuanto a recurrencia y uso de colgajos. El promedio de defecto para los tumores retomados fue 27,8mm y para los no retomados 22,8mm, siendo la diferencia estadísticamente significativa (p=0.002). En el subgrupo de lesiones retomadas se encontró tumor residual en solo 2,9% de las mismas. Conclusiones: las retomas adicionaron en promedio 5mm de defecto por lesión sin aportar beneficios en términos de recurrencia. Un uso más conservador de las mismas podría traducirse en mejores resultados funcionales y cosméticos

Background: the lowest recurrence rates for basal cell carcinoma are achieved by surgical treatment. Low rates of residual tumour in specimens after incomplete excisions plus intraoperative frozen section accuracy are the rationale for analyzing the value of intraoperative re-excisions during basal cell carcinoma standard surgery. Objective: to analyse intraoperative oncologic and cosmetic results of re-captures in patients surgically treated of basal-cells carcinoma. Secondary to analyse subclinic extention, the value of frozen intraoperative sections and reconstructive conducts employed. Setting: tertiary care Hospital of tumours. Methods: observational retrospective study. During a 3-year period 84 tumours were resected. A comparative analysis in terms of recurrence, surgical defect and use of flaps was done between intraoperatively re-excised and not re-excised tumours. Results: there were no statistical difference regarding recurrence rate and use of flaps. Mean surgical defect for re-excised and not re-excised specimens was 27,8mm and 22,8mm respectively, being the difference statistically significant (p=0.002). Residual tumour was found in only 2,9% of re-excised specimens. Conclusions: re-excisions added on average 5mm to surgical defect per specimen and did not contribute to any benefit in terms of recurrence rates. A more conservative use of intraoperative re-excisions could improve functional and cosmetic outcomes

Humans , Recurrence , Carcinoma, Basal Cell/surgery , Retrospective Studies , Cohort Studies , Reconstructive Surgical Procedures/methods , Freezing , Head and Neck Neoplasms/surgery
Article in Chinese | WPRIM | ID: wpr-878719


Objective To investigate the effects of self-made carriers on the cryopreservation of ovarian tissue of sheep. Methods Thirty-two ovaries were randomly assigned to fresh group,programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group.The morphology,proliferation,apoptosis,and estrogen level of the ovarian tissue in each group were observed. Results After cryopreservation,the morphology normal rate of the primordial follicles in programmed freezing group,self-made carrier I vitrification group,and self-made carrier Ⅱ vitrification group were 74.2%,72.8%,and 72.3%,respectively,lower than that(83.7%)in the fresh group(χ

Animals , Cryopreservation , Female , Freezing , Ovarian Follicle , Ovary , Sheep , Vitrification
Rev. Inst. Adolfo Lutz ; 80(Único): e37320, dez. 2021. tab, ilus
Article in English | ColecionaSUS, LILACS, ColecionaSUS, SES-SP, CONASS, SESSP-ACVSES, SESSP-IALPROD, SES-SP, SESSP-IALACERVO | ID: biblio-1368348


Freezing is an important strategy to keep fish quality and make the species available the whole year. Its effects on the nutritional value of 17 fish species were studied in samples of entire fish, fillets or pieces. One portion of homogenized flesh was analyzed just after purchase (fresh sample). The other portion was packed in polyethylene bag, sealed, quick frozen (-80°C), stored properly at -18°C and analyzed after 12 months (frozen sample). Moisture, ash and protein content were tested using Brazilian Supply, Livestock and Agriculture Ministry methodologies. Lipid content was analyzed through Bligh and Dyer method. Carbohydrate content and caloric value were calculated, using NIFEXT fraction and Atwater coefficient, respectively. When fresh and frozen samples were compared, moisture and ash content showed significant difference (p<0.05) for 17.65% and 11.77% species, respectively. Lipid and protein contents were the most affected parameters, as they were altered in 29.40% of the studied species (p<0.05), and therefore, highlighted the importance of the conservation technology used on nutritional quality of fishery products. Mullet (M. brasiliensis) and Atlantic salmon (S. salar) had their nutritional composition more affected by freezing process with five and four altered parameters, respectively, from the six studied. (AU)

O congelamento é estratégia importante para manter a qualidade do peixe e tornar inúmeras espécies disponíveis o ano todo. Seus efeitos sobre o valor nutricional de 17 espécies foram estudados em amostras de peixes inteiros, filés ou postas. A porção cárnea homogeneizada foi analisada logo após a aquisição (amostra fresca). Outra parte foi embalada em polietileno, selada, rapidamente congelada (-80°C) e analisada após 12 meses de armazenamento a -18°C (amostra congelada). O teor de umidade, cinzas e proteína foram testados com metodologias do Ministério de Agricultura, Pecuária e Abastecimento e teor de lipídios com método de Bligh e Dyer. Conteúdo de carboidrato e valor calórico foram calculados, utilizando fração NIFEXT e coeficiente de Atwater, respectivamente. Quando se comparou amostras frescas e congeladas, teor de umidade e cinzas evidenciaram diferenças significativas (p<0,05) para 17,65% e 11,77% das espécies, respectivamente. O teor de lipídios e de proteínas foram alterados em 29,40% das espécies estudadas (p<0,05), sendo os parâmetros mais afetados pelo congelamento e destacaram a importância da tecnologia de conservação utilizada sobre a qualidade nutricional do pescado. Tainha (M. brasiliensis) e salmão (S. salar) foram as mais afetadas pelo congelamento, com 5 e 4 parâmetros alterados, respectivamente, após estocagem sob congelamento. (AU)

Food Quality , Fishes , Freezing , Food Supply , Nutritive Value
Rev. bras. ortop ; 55(6): 778-782, Nov.-Dec. 2020. graf
Article in English | LILACS | ID: biblio-1156183


Abstract Objectives The present paper aims to evaluate and compare the histological features of fresh and frozen menisci stored in a tissue bank for 1 month and for 5 years. Methods The meniscal grafts were subjected to a histological study. A total of 10 menisci were evaluated; 2 were frozen for 5 years, 4 were frozen for 1 month, and 4 were fresh, recently harvested specimens. Histological properties were evaluated in sections stained with hematoxylin and eosin and Masson trichrome methods. Results The menisci frozen for 1 month showed partially preserved collagen fiber structure and no significant hydropic tissue degeneration. The menisci frozen for 5 years presented an evident dissociation of collagen fibers and multiple foci of hydropic degeneration. Discussion Degeneration was much more significant in menisci stored for 5 years, indicating that a long freezing period results in substantial progression of tissue deterioration. This may suggest that the 5-year period, considered the maximum time for graft storage before transplant, is too long. Conclusion Grafts stored for 1 month showed a slight degenerative change in collagen fibers, whereas menisci frozen for 5 years presented significant tissue degeneration.

Resumo Objetivos Avaliar e comparar as características histológicas de meniscos frescos e meniscos congelados armazenados em banco de tecidos por 1 mês e por 5 anos. Métodos Foi feito um estudo histológico com enxertos meniscais. Avaliamos 10 meniscos, sendo 2 que ficaram armazenados sob congelamento por 5 anos, 4 armazenados congelados por 1 mês, e 4 frescos, recém captados. Foram feitos cortes histológicos corados com hematoxilina e eosina e Tricrômico de Masson, para avaliação das propriedades histológicas. Resultados Os meniscos congelados por 1 mês apresentaram preservação parcial da estrutura das fibras colágenas, sem degeneração hidrópica significativa do tecido. Nos meniscos congelados por 5 anos, observamos dissociação evidente das fibras colágenas, com presença de múltiplos focos de degeneração hidrópica. Discussão Encontramos degeneração bem mais significativa nos meniscos armazenados por 5 anos, o que indica que o longo período de congelamento leva à progressão significativa da degeneração do tecido. Isto pode sugerir que o período de 5 anos, considerado período máximo que o enxerto pode permanecer armazenado antes de ser transplantado, é um período muito longo. Conclusão Nos enxertos armazenados por 1 mês, existiu apenas discreta alteração degenerativa das fibras colágenas, enquanto que nos meniscos com 5 anos de congelamento foi observada degeneração significativa do tecido. Tibiais

Tissue Banks , Wounds, Penetrating , Collagen , Eosine Yellowish-(YS) , Transplants , Meniscus , Freezing , Goals , Hematoxylin
Arq. bras. med. vet. zootec. (Online) ; 72(5): 1713-1718, Sept.-Oct. 2020. graf, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1131538


A total of 480 milk samples were analyzed in four repetitions with four preservative treatments (no preservative, Bronopol, Bronolat and Brononata), three storage times at temperatures up to 4 °C (24, 48 and 72hours after reception), five different water additions (0.0, 2.5, 5.0, 7.5 and 10.0%) and two analytical instruments (electronic cryoscope and FTIR). The objective of this study was to evaluate the effect of these parameters in the determination of the freezing point by the reference method and by Fourier transform infrared spectroscopy, thus determining the best analytical conditions and establishing a mathematical equation for electronic determination by FTIR spectroscopy. Bronolat was the best preservative and Brononata was the worst and is not recommended to analyze freezing point by FTIR. The storage time of the samples did not interfere in the analytical determinations by the precision method and by FTIR.(AU)

Foram analisadas 480 amostras de leite em quatro repetições em relação a quatro tratamentos por conservantes (sem conservante, bronopol, bronolat e brononata), três tempos de armazenamento, em temperatura até 4ºC desde a recepção da amostra (24, 48 e 72 horas), cinco porcentagens de adição de água (0,0; 2,5; 5,0; 7,5 e 10,0%) e dois instrumentos analíticos (crioscópio eletrônico e FTIR). O objetivo foi avaliar o efeito desses parâmetros na determinação do índice crioscópico pelo método de precisão em crioscópio eletrônico e por espectroscopia com transformada de Fourier no infravermelho, determinando-se, assim, as melhores condições analíticas. Entre os conservantes utilizados, bronolat foi o melhor e brononata foi o menos eficiente, não sendo, portanto, recomendado para análise de crioscopia por FTIR. O tempo de armazenamento das amostras não interferiu nas determinações analíticas pelo método de precisão e por FTIR.(AU)

Milk/chemistry , Raw Foods/analysis , Food Preservatives , Freezing , Frozen Foods/analysis , Spectroscopy, Fourier Transform Infrared
Chinese Medical Journal ; (24): 800-805, 2020.
Article in English | WPRIM | ID: wpr-877958


BACKGROUND@#It is currently unknown whether patients with a fever after controlled ovulation during egg retrieval could increase the risk of pelvic infection or not, and fever itself may affect endometrial receptivity or embryo quality with poor pregnancy outcomes. The aim of this study was to analyze the outcomes of patients with fever during oocyte retrieval after the first frozen-thawed embryo transfer (FET) cycle.@*METHODS@#This was a 1:3 retrospective paired study matched for age. In this study, 58 infertility patients (Group 1) had a fever during the control ovulation, and the time of the oocyte retrieval was within 72 hours, they underwent ovum pick up and whole embryo freezing ("freeze-all" strategy). The control subjects (Group 2) are 174 patients matched for age who underwent whole embryo freezing for other reasons. The baseline characteristics, clinical data of ovarian stimulation, and outcomes, such as the clinical pregnancy rate, ongoing clinical pregnancy rate were compared between the two groups in the subsequent FET cycle.@*RESULTS@#All patients had no pelvic inflammatory disease after oocyte retrieval. Anti-Mullerian hormone (AMH) levels (4.2 vs. 2.2, P <0.001) were higher in group 2, and the number of oocytes retrieved, and fertilization rate were lower in group 1 (P < 0.001), but the endometrial thickness, the number of embryo transfers, and the type of luteal support supplementation were similar between the two groups. Regarding pregnancy outcomes in the subsequent FET cycle, the implantation rate, clinical pregnancy rate, early spontaneous rate, ectopic pregnancy rate, and ongoing pregnancy rate were all not significantly different. Further regression analyses showed that the clinical pregnancy rate and ongoing pregnancy rate were also not significantly different.@*CONCLUSIONS@#Transvaginal ultrasound-guided follicular puncture for oocyte retrieval is a safe and minimally invasive method for patients with fever. Moreover, the fever had almost no effect on embryo quality.

Cryopreservation , Female , Fertilization in Vitro , Freezing , Humans , Infertility , Oocyte Retrieval , Oocytes , Ovulation Induction , Pregnancy , Pregnancy Outcome , Pregnancy Rate , Retrospective Studies
Article in Korean | WPRIM | ID: wpr-811322


PURPOSE: To report a case of corneal collagen cross-linking for corneal ulcer caused by the Moraxella group.CASE SUMMARY: A 77-year-old male had decreased visual acuity for several days in his right eye. The patient showed severe stromal ring infiltrates with a corneal epithelial defect measuring (5.0 × 7.0 mm), a corneal endothelial plaque, and a hypopyon measuring less than 1.0 mm in height in the anterior chamber of the right eye. There was no abnormal finding in the right eye using B-scan ultrasonography. Before starting treatment, a corneal culture was conducted. The culture tests showed the presence of the Moraxella group. Because the patient was diagnosed with a corneal ulcer caused by the Moraxella group, corneal collagen cross-linking (CXL) was performed. The antimicrobial susceptibility test confirmed that this Moraxella group was sensitive to ceftazidime, so the patient was treated with 5% ceftazidime eye drops and 0.5% moxifloxacin eye drops every 2 hours for 9 months after corneal collagen CXL. The uncorrected visual acuity was 0.1 in the right eye, and there was almost no corneal stromal melting on anterior segment optical coherence tomography.CONCLUSIONS: This is the first known case of a corneal ulcer, in the Republic of Korea, caused by the Moraxella group and treated with corneal collagen CXL. Corneal collagen CXL should be considered as a surgical treatment for patients who have an impending corneal perforation due to a corneal ulcer because it is a simple procedure and causes fewer serious complications than other treatments.

Aged , Anterior Chamber , Ceftazidime , Collagen , Cornea , Corneal Perforation , Corneal Ulcer , Freezing , Humans , Male , Moraxella , Ophthalmic Solutions , Republic of Korea , Tomography, Optical Coherence , Ultrasonography , Visual Acuity
Säo Paulo med. j ; 137(5): 407-413, Sept.-Oct. 2019. tab
Article in English | LILACS | ID: biblio-1059102


ABSTRACT BACKGROUND: Vegetables have some beneficial effects on human health due to their antioxidant compounds, like polyphenols. Cooking leads to many physical and chemical changes to plant structure that can alter the phytochemical compounds of vegetables. OBJECTIVES: To investigate the effects of heat treatment and freezing on the antioxidant properties of garlic, onion, broccoli and cauliflower. DESIGN AND SETTING: Experimental in vitro study in a university laboratory. METHODS: Fresh broccoli (Brassica oleracea var. italica), cauliflower (Brassica oleracea var. botrytis), garlic (Allium sativum) and onion (Allium cepa) were obtained from a local store. These vegetables were divided into three treatment groups: raw, heated and frozen. The heat treatment consisted of heating them in a drying oven at 150 °C for 20 minutes. The freezing treatment consisted of keeping them frozen at -20 °C until analysis. The total phenolic content, antioxidant activity and malondialdehyde levels of the vegetables were measured using the Folin-Ciocalteu phenol reagent, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and thiobarbituric acid reactive substances, respectively. RESULTS: Heat treatment had deleterious effects on the antioxidant properties of onion and garlic; and it decreased the antioxidant activity of broccoli. Freezing improved the antioxidant activity of broccoli and garlic, but had detrimental effects for cauliflower and onion. CONCLUSIONS: Heat treatment and freezing exhibit different effects on the antioxidant properties of broccoli, cauliflower, garlic and onion. Convenient cooking and storage patterns should be identified for each vegetable, to obtain the best nutritional benefit from the antioxidant compounds of vegetables.

Vegetables/chemistry , Allium/chemistry , Food Handling/methods , Food Preservation/methods , Malondialdehyde/analysis , Antioxidants/analysis , In Vitro Techniques , Brassica/chemistry , Plant Extracts/chemistry , Onions/chemistry , Freezing , Garlic/chemistry , Heating , Nutritive Value
Electron. j. biotechnol ; 41: 88-94, sept. 2019. tab, ilus, graf
Article in English | LILACS | ID: biblio-1087247


Background: In industrial yeasts, selection and breeding for resistance to multiple stresses is a focus of current research. The objective of this study was to investigate the tolerance to multiple stresses of Saccharomyces cerevisiae obtained through an adaptive laboratory evolution strategy involving a repeated liquid nitrogen freeze­thaw process coupled with multi-stress shock selection. We also assessed the related resistance mechanisms and very high-gravity (VHG) bioethanol production of this strain. Results: Elite S. cerevisiae strain YF10-5, exhibiting improved VHG fermentation capacity and stress resistance to osmotic pressure and ethanol, was isolated following ten consecutive rounds of liquid nitrogen freeze­thaw treatment followed by plate screening under osmotic and ethanol stress. The ethanol yield of YF10-5 was 16% higher than that of the parent strain during 35% (w/v) glucose fermentation. Furthermore, there was upregulation of three genes (HSP26, HSP30, and HSP104) encoding heat-shock proteins involved in the stress response, one gene (TPS1) involved in the synthesis of trehalose, and three genes (ADH1, HXK1, and PFK1) involved in ethanol metabolism and intracellular trehalose accumulation in YF10-5 yeast cells, indicating increased stress tolerance and fermentative capacity. YF10-5 also showed excellent fermentation performance during the simultaneous saccharification and fermentation of VHG sweet potato mash, producing 13.40% (w/ v) ethanol, which corresponded to 93.95% of the theoretical ethanol yield. Conclusions: A multiple-stress-tolerant yeast clone was obtained using adaptive evolution by a freeze­thaw method coupled with stress shock selection. The selected robust yeast strain exhibits potential for bioethanol production through VHG fermentation.

Saccharomyces cerevisiae/physiology , Ethanol/chemical synthesis , Saccharomyces cerevisiae/genetics , Selection, Genetic , Stress, Physiological , Trehalose , Yeasts , Breeding , Adaptation, Physiological , Hypergravity , Fermentation , Real-Time Polymerase Chain Reaction , Freezing , Heat-Shock Proteins
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
Biosci. j. (Online) ; 35(2): 503-508, mar./apr. 2019. tab
Article in English | LILACS | ID: biblio-1048605


The aim of this study was to evaluate the effect of banana leaf extract on the quality and shelf life of rainbow trout compared to plastic bags at freezing temperature for 40 days. For evaluating this propose, the antioxidant activity of banana leaf extract was assessed. In addition, the shelf life of fish filets was determined by measuring thiobarbituric acid (TBA) and pHof fish. The banana leaves extract showed the highest content of vitamin E (5.8 ± 0.61 mg /g) and carotenoids (12.8 ± 0.1 mg /g). The potential of Cu (II) reduction the extract was 1.76 ± 0.09. The magnitude of modification in TBA and pH of the packed fish with banana leaves were less than the control samples. The present study demonstrated that the use of banana leaf extract will retard lipid oxidation in fish. fillet during freezing storage that may due to its strong antioxidant properties.

O objetivo deste estudo foi avaliar o efeito do extrato de folhas de bananeira sobre a qualidade e vida de prateleira da truta arco-íris comparada a sacolas plásticas na temperatura de congelamento por 40 dias. Para avaliar essa proposta, foi determinada a atividade antioxidante do extrato de folhas de bananeira. Além disso, a vida de prateleira dos filés de peixe foi determinada medindo o ácido tiobarbitúrico (TBA) e o pH do peixe. O extrato de folhas de bananeira apresentou o maior teor de vitamina E (5,8 ± 0,61 mg/g) e carotenóides (12,8 ± 0,1 mg/g). O potencial de redução de Cu (II) no extrato foi de 1,76 ± 0,09. A magnitude da modificação no TBA e pH do peixe embalado com folhas de bananeira foi menor que as amostras controle. O presente estudo demonstrou que o uso de extrato de folhas de bananeira é capaz de retardar a oxidação lipídica no filé de peixe durante o armazenamento de congelamento, devido às suas fortes propriedades antioxidantes.

Plant Extracts , Oncorhynchus mykiss , Musa , Date of Validity of Products , Antioxidants , Product Packaging , 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
Einstein (Säo Paulo) ; 17(2): eAO4533, 2019. graf
Article in English | LILACS | ID: biblio-1001901


ABSTRACT Objective To evaluate the feasibility and applicability of a low-cost cryotherapy system. Methods Experimental study with 25kg Landrace pigs submitted to a longitudinal cervico-thoraco-abdominal incision for exposure of the trachea, thorax and abdomen. The tissues were frozen by continuous spray application at different periods of time (5, 10 and 15 seconds). Spray cryotherapy was performed using a fluorinated gas (tetrafluorethane) delivered at - 47°C temperature (DermaFreeze®, Emdutos; ANVISA registration 80409950001; price R$ 394,00). via an adapted, disposable 1.8mm cholangiography catheter (Olympus; price R$ 280,00). The specimens were resected for histopathological analysis. Results Thirty samples were obtained from ten different organs and divided according to spray cryotherapy application time. System activation for 5, 10 or 15 seconds led to consumption of 14g, 27g and 40g of gas respectively (average gas consumption, 2.7g/s using a 1.8mm catheter). The system comprising a spray tube and catheter proved user-friendly and effective, with constant gas dispersion and adequate tissue freezing. In spite of effective freezing, microscopy failed to reveal tissue changes. This may have reflected methodological constraints precluding evaluation at tissue damage peak time (48 hours). Conclusion The low-cost spray cryotherapy system proved feasible and safe.

RESUMO Objetivo Avaliar a exequibilidade e a aplicação de um sistema de baixo custo de crioterapia. Métodos Estudo experimental realizado com um suíno da raça Landrace, 25kg, submetido à cervicotoracolaparotomia longitudinal, com exposição de traqueia, tórax e abdome. Procedemos ao congelamento das estruturas em tempos diferentes (5, 10 e 15 segundos) com jato contínuo. A crioterapia foi realizada com gás fluoretado (tetrafluoretano), na forma de spray em tubo, que atinge a temperatura de -47°C (DermaFreeze®, Emdutos; registro ANVISA 80409950001; preço R$ 394,00). A este tubo, adaptamos um cateter descartável de colangiografia de 1,8mm (Olympus; preço R$ 280,00). As peças foram ressecadas para análise histopatológica. Resultados Foram obtidas 30 amostras em 10 órgãos diferentes, divididos em três intervalos de tempo distintos. Quando o sistema foi acionado por 5 segundos, gastaram-se 14g de gás; por 10 segundos, 27g; e por 15 segundos, 40g; o gasto médio foi de 2,7g/s pelo cateter de 1,8mm. O sistema confeccionado com tubo de gás e cateter proporcionou resultado efetivo, com dispersão adequada e constante do gás, congelamento adequado e de fácil execução. Apesar da técnica evidenciar congelamento efetivo, na microscopia não houve alteração tecidual. Isso ocorreu porque o pico de lesão tecidual por congelamento ocorre após 48 horas, o que não foi possível avaliar por este método proposto. Conclusão O sistema de crioterapia em spray de baixo custo foi exequível e seguro.

Animals , Cryotherapy/methods , Gases/pharmacology , Swine , Time Factors , Reproducibility of Results , Cryotherapy/economics , Cryotherapy/instrumentation , Catheters , Freezing
Article in English | WPRIM | ID: wpr-760338


To establish appropriate conditions for a disinfectant efficacy test at subzero temperatures, this study examined mixtures of frozen foot-and-mouth disease virus or avian influenza virus solutions and disinfectant diluents at −5℃ and monitored temperature and freezing status of an anti-freezing diluent (AFD, 15% ethanol + 30% propylene glycol + 55% distilled water) over time at various subzero temperatures. Viral solutions and disinfectant diluents froze before the mixtures reached −5℃, whereas the AFD was not frozen at −30℃. The times taken for the AFD to reach −10, −20, −30, and −40℃ from room temperature were 36, 39, 45, and 48 min, respectively.

Animals , Ethanol , Foot-and-Mouth Disease Virus , Freezing , Influenza in Birds , Propylene Glycol
Article in English | WPRIM | ID: wpr-742312


Melting temperature shift (T(m)-shift) is a new detection method that analyze the melting curve on real-time PCR thermocycler using SYBR Green I fluorescent dye. To establish a T(m)-shift method for the detection of Ancylostoma ceylanicum and A. tubaeforme in cats, specific primers, with GC tail of unequal length attached to their 5′ end, were designed based on 2 SNP loci (ITS101 and ITS296) of the internal transcribed spacer 1 (ITS1) sequences. The standard curve of T(m)-shift was established using the standard plasmids of A. ceylanicum (AceP) and A. tubaeforme (AtuP). The T(m)-shift method stability, sensitivity, and accuracy were tested with reference to the standard curve, and clinical fecal samples were also examined. The results demonstrated that the 2 sets of primers based on the 2 SNPs could accurately distinguish between A. ceylanicum and A. tubaeforme. The coefficient of variation (CV) of T(m)-values of AceP and AtuP was 0.07% and 0.06% in ITS101 and was 0.06% and 0.08% in ITS296, respectively. The minimum detectable DNA concentration was 5.22×10⁻⁶ and 5.28×10⁻⁶ ng/μl samples of AceP and AtuP, respectively. The accuracy of T(m)-shift method reached 100% based on examination of 10 hookworm DNA samples with known species. In the clinical detection of hookworm in 69 stray cat fecal sample, the T(m)-shift detection results were consistent with the microscopic examination and successfully differentiated between the 2-hookworm species. In conclusion, the developed method is a rapid, sensitive and accurate technique and can provide a promising tool for clinical detection and epidemiological investigation of cat-derived hookworms.

Ancylostoma , Ancylostomatoidea , Animals , Cats , DNA , Freezing , Methods , Plasmids , Polymorphism, Single Nucleotide , Real-Time Polymerase Chain Reaction , Tail
Article in English | WPRIM | ID: wpr-765850


OBJECTIVE: Ample evidence has suggested that age at onset of Parkinson's disease (PD) is associated with heterogeneous clinical features in individuals. We hypothesized that this may be attributed to different patterns of nigrostriatal dopamine loss. METHODS: A total of 205 consecutive patients with de novo PD who underwent 18F-FP-CIT PET scans (mean follow-up duration, 6.31 years) were divided into three tertile groups according to their age at onset of parkinsonian motor symptoms. Striatal dopamine transporter (DAT) availability was compared between the old- (n = 73) and young-onset (n = 66) groups. In addition, the risk of developing freezing of gait (FOG) and longitudinal requirements for dopaminergic medications were examined. RESULTS: The old-onset PD group (mean age at onset, 72.66 years) exhibited more severe parkinsonian motor signs than the young-onset group (52.58 years), despite comparable DAT availability in the posterior putamen; moreover, the old-onset group exhibited more severely decreased DAT availability in the caudate than the young-onset group. A Cox regression model revealed that the old-onset PD group had a higher risk for developing FOG than the young-onset group [hazard ratio 2.523, 95% confidence interval (1.239–5.140)]. The old-onset group required higher doses of dopaminergic medications for symptom control than the young-onset group over time. CONCLUSION: The present study demonstrated that the old-onset PD group exhibited more severe dopamine loss in the caudate and were more likely to develop gait freezing, suggesting that age at onset may be one of the major determinants of the pattern of striatal dopamine depletion and progression of gait disturbance in PD.

Age of Onset , Dopamine Plasma Membrane Transport Proteins , Dopamine , Follow-Up Studies , Freezing , Gait , Humans , Parkinson Disease , Positron-Emission Tomography , Putamen , Weather
Article in English | WPRIM | ID: wpr-763355


OBJECTIVE: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. METHODS: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. RESULTS: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. CONCLUSION: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

Acrosome , Chromatin , Cryopreservation , DNA Fragmentation , DNA , Freezing , Humans , Infertility, Male , Male , Membranes , Reproductive Techniques, Assisted , Semen , Semen Analysis , Sperm Head , Sperm Motility , Spermatozoa , Tail
Chinese Journal of Biotechnology ; (12): 307-318, 2019.
Article in Chinese | WPRIM | ID: wpr-771375


We explored the improved method to prepare decellularized kidney scaffold and provide experimental basis for kidney tissue engineering and renal pathology and toxicology in vitro research. We perfused rat kidneys with PBS (group control) and prepared the decellularized kidney scaffolds with sodium dodecyl sulfate (SDS) (group S), Triton X-100 combined with SDS (group TS), and Triton X-100 combined with SDS after repeated freezing and thawing (group FTS) in different flow velocity. Meanwhile we measured their fluid distributions and vascular resistance. We examined the degree of decellularization of acellular scaffolds by HE, DAPI staining and DNA quantification. We examined the retention of main composition and structural integrity of decellularized scaffolds by Masson, PAS and immunohistochemical staining. We also detected the ultrastructure, cytotoxicity and the level of growth factor of the scaffolds by scanning electron microscope, MTT and ELISA, respectively. The results showed that the time of decellularization in group FTS was less than that in group S and TS. The vascular resistance of scaffolds decellularized at 10 mL/min flow velocity was lower. The fluid distribution in groups S, TS and FTS was different from that in control group. No residual cell was detected by HE and DAPI staining. DNA content was less than 50 ng/mg. Masson, PAS and immunohistochemical staining results showed that there was extracellular collagen, polysaccharide, type I collagen, type IV collagen, fibronectin and laminin in the decellularized scaffolds, and the scanning electron microscope result showed the scaffolds had the honeycomb structure. The cytotoxicity level of decellularized scaffolds was between grade 0 to 1. The level of VEGF, EGF, IGF-1 and PDGF-BB in group FTS were significantly higher than those in group S and TS. In concluding, combining freeze-thawing with perfusion can produce more ideal and effective whole organ decellularized scaffold of rat kidney, and make a foundation for the study of kidney tissue engineering and in vitro pathology and toxicology of kidney.

Animals , Collagen , Extracellular Matrix , Freezing , Kidney , Perfusion , Rats , Tissue Engineering , Tissue Scaffolds
Article in Chinese | WPRIM | ID: wpr-774139


Cell freeze-drying can be divided into the freezing and drying processes. Mechanical damage caused by ice crystals and damage from solute during freezing shall not be ignored and lyoprotectants are commonly used to reduce those damages on cells. In order to study the mechanism of lyoprotectants to protect cells and determine an optimal lyoprotectant formula, the thermophysical properties and percentage of unfrozen water of different lyoprotectants in freezing were investigated with differential scanning calorimeter (DSC). The survival rate indicated by trypan blue exclusion test and cell-attachment rate after 24 h using different lyoprotectants to freeze hepatoma Hep-G cells were measured after cell cryopreservation. The results show that 40% (W/V) PVP + 10% (V/V) glycerol + 15% (V/V) fetal bovine serum + 20% (W/V) trehalose formula of lyoprotectant demonstrate the best effect in protecting cells during freezing, for cell-attachment rate after 24 h is 44.56% ± 2.73%. In conclusion, the formula of lyoprotectant mentioned above can effectively protect cells.

Calorimetry, Differential Scanning , Cryopreservation , Cryoprotective Agents , Chemistry , Freeze Drying , Freezing , Hep G2 Cells , Humans , Trehalose , Chemistry