RESUMEN

The use of biological membranes in wound dressings has increasingly become a reality. Accordingly, an ideal means of preservation is sought that can provide tissue maintenance for long periods without interfering with its quality or clinical applicability. Therefore, the objective of the present study was to evaluate and histologically and microbiologically compare frog skins subjected to two different preservation methods. Sixteen frog skins were evaluated and, depending on the preservation method, subdivided into two groups with eight skins each, namely, the Freezing Group, in which the skins were frozen at -4º in a 20% glycerin solution; and the Glycerin Group, whose skins were kept in 98% glycerin at room temperature (average of 28 ºC and average humidity of 78%). The skins were analyzed fresh (T0) and at 30 (T1), 60 (T2), 90 (T3), and 120 (T4) days of preservation. Data were analyzed comparatively. There was no bacterial or fungal growth, and the skin structure and collagen arrangement remained intact at all time points in both treatments. In conclusion, both preservation methods are efficient and capable of maintaining the tissue morphological structure and preventing the growth and proliferation of contaminants for up to 120 days.

A utilização de membranas biológicas em curativos tem se tornado cada vez mais uma realidade. Concomitante, busca-se um meio de conservação ideal que possa proporcionar a manutenção do tecido por longos períodos de tempo sem interferir em sua qualidade e aplicabilidade clínica. Desta forma, o objetivo deste trabalho foi o de avaliar e comparar histologicamente e microbiologicamente peles de rã submetidas a dois diferentes métodos de conservação. Foram avaliadas 16 peles de rã-touro as quais foram, em função do método de conservação, subdivididas em dois grupos com 08 peles cada: O Grupo Congelamento (GC) no qual as peles foram submetidas ao congelamento a -4º, em solução de glicerina a 20%; e o grupo Glicerina (GG), no qual as peles foram conservadas em temperatura ambiente (média de 28ºC e umidade média de 78%) em glicerina a 98%. As peles foram analisadas a fresco (T0) e com 30 (T1), 60 (T2), 90 (T3) e 120 (T4) dias de conservação. Os dados foram analisados de forma comparativa. Em todos os tempos analisados e em ambos os tratamentos, não houve crescimento bacteriano ou fúngico e a estrutura da pele e o arranjo de colágeno mantiveram-se íntegros. Conclui-se que, ambos os métodos de conservação são eficientes e capazes de manter a estrutura morfológica tecidual, e impedem o crescimento e a proliferação de contaminantes por até 120 dias.

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Las membranas biológicas se emplean como implantes en cirugía veterinaria reconstructiva con el objetivo de restablecer la función y la estructura de tejidos dañados. Diversos tejidos obtenidos de animales, conservados por diferentes técnicas e implantados en receptores de la misma o de diferente especie, permiten reparar heridas en las que es evidente la extensa pérdida tisular o la imposibilidad de inducir cicatrización por primera intención. Aunque las bondades de las membranas biológicas son mayores que sus desventajas, su uso en la rutina clínica y quirúrgica no es frecuente, en gran parte por el desconocimiento de sus características, manipulación e implantación. La presente revisión pretende recopilar los aspectos generales que envuelven las membranas biológicas, desde su obtención hasta las posibles complicaciones de su uso, a través de estudios experimentales y reportes de caso relatados con anterioridad, e incentivar su uso como biomaterial de implante en defectos anatómicos, heridas traumáticas, postoperatorios oncológicos y traumas en general.

Biological membranes are used as implants in veterinary reconstructive surgery in order to restore the function and structure of damaged tissues. Various tissues from animals, kept by different techniques and implanted in recipients of the same or different species, help repair wounds where extensive tissue loss or the inability to scarring is evidenced. Although the benefits of biological membranes outweigh their disadvantages, their use in clinical and surgical routines is rare, largely due to ignorance of their characteristics, handling and implantation. The present article aims to review general aspects on biological membranes, from procurement to possible complications of their use, through experimental studies and previously reported cases, and to encourage their use as a biomaterial implant in case of anatomical defects, traumatic wounds, oncological postoperative care, and traumas in general.

As membranas biológicas se empregam como implantes em cirurgia veterinária reconstrutiva com o objetivo de restabelecer a função e a estrutura de tecidos destruídos. Diversos tecidos obtidos de animais, conservados por diferentes técnicas e implantados em receptores da mesma ou de diferente espécie, permitem reparar feridas aonde é evidente a extensa perda tissular ou a impossibilidade de induzir cicatrização por primeira intenção. Ainda que as bondades das membranas biológicas sejam maiores que suas desvantagens, seu uso na rotina clínica e cirúrgica não é frequente, em grande parte pelo desconhecimento de suas características, manipulação e implantação. Esta revisão pretende recopilar os aspectos gerais que envolvem as membranas biológicas, desde sua obtenção até as possíveis complicações de seu uso, através de estudos experimentais e relatórios de caso relatados com anterioridade, e incentivar seu uso como bio material de implante em defeitos anatômicos, feridas traumáticas, pós-operatórios oncológicos e traumas em geral.

RESUMEN

Devido à complexidade de patologias como: hérnias perianais, diafragmáticas, ressecções de grande número de costelas da parede torácica e traumatismos em traqueia, se faz necessário a utilização de membranas biológicas para auxiliar na reparação e restauração das funções normais destas regiões acometidas. O objetivo do presente trabalho é discutir algumas alternativas na reparação destas lesões com a utilização de membranas biológicas e os métodos de conservação das mesmas na clínica de pequenos animais.AU

Due to the complexity of diseases such as perianal hernias, diaphragmatic resection of a large number of ribs on the chest wall and trauma in trachea, it is necessary the use of biological membranes to assist in the repair and restoration of normal functions in those regions affected. The aim of this paper is to discuss some alternatives in the repair of these lesions with the use of biological membranes and methods of conservation of the same on the clinic of small animals.

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RESUMEN

Devido à complexidade de patologias como: hérnias perianais, diafragmáticas, ressecções de grande número de costelas da parede torácica e traumatismos em traqueia, se faz necessário a utilização de membranas biológicas para auxiliar na reparação e restauração das funções normais destas regiões acometidas. O objetivo do presente trabalho é discutir algumas alternativas na reparação destas lesões com a utilização de membranas biológicas e os métodos de conservação das mesmas na clínica de pequenos animais.

Due to the complexity of diseases such as perianal hernias, diaphragmatic resection of a large number of ribs on the chest wall and trauma in trachea, it is necessary the use of biological membranes to assist in the repair and restoration of normal functions in those regions affected. The aim of this paper is to discuss some alternatives in the repair of these lesions with the use of biological membranes and methods of conservation of the same on the clinic of small animals.

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Background: Biological membranes demonstrate superiority over synthetic ones for its biocompatibility and strength in the reduction of abdominal hernias. Recents tissue engineering researches add mesenchymal stem cells to biological membranes with the purpose of obtaining additional cellular proliferation and consequent muscle regeneration, using biological membranes as cellular scaffolds. This article aimed to study the influence of mesenchymal stem cells in muscle regeneration in abdominal hernias, reduced with biological membranes. Materials, Methods & Results: Adult Wistar rats underwent abdominal hernia-inducing. They were divided into two groups as to the form of treatment for the reduction of hernia: stem cells associated with biological membranes or only biological membranes. After the treatment the macro and microscopic reviews were carried out in days seven, 14 and 60 postoperatively. Preparation of bovine pericardium with glycerin 98% presented efficiency in decellularization and conservation, maintaining its strength and avoiding bacterial growth. The mesenchymal stem cells obtained from bone marrow of adult Wistar rats, had capacity of proliferation. The majority of the cells was positive for the expression of surface antigens CD44, CD29 and CD99 and was negative for CD 34. In the differentiation trials, the same cells were able to differentiate into adipocytes

Vários tipos de implantes, naturais ou sintéticos, vêm sendo testados no reparo cirúrgico de hérnias. As membranas biológicas, ou arcabouços dérmicos descelularizados, apresentam reduzida formação de aderência entre o implante e as vísceras, diminuição da formação de fístulas, infecções e recorrências. Também apresentam resistência suficiente para suportar a pressão abdominal, evitando deiscências e eviscerações. [...]

RESUMEN

Background: Biological membranes demonstrate superiority over synthetic ones for its biocompatibility and strength in the reduction of abdominal hernias. Recents tissue engineering researches add mesenchymal stem cells to biological membranes with the purpose of obtaining additional cellular proliferation and consequent muscle regeneration, using biological membranes as cellular scaffolds. This article aimed to study the influence of mesenchymal stem cells in muscle regeneration in abdominal hernias, reduced with biological membranes. Materials, Methods & Results: Adult Wistar rats underwent abdominal hernia-inducing. They were divided into two groups as to the form of treatment for the reduction of hernia: stem cells associated with biological membranes or only biological membranes. After the treatment the macro and microscopic reviews were carried out in days seven, 14 and 60 postoperatively. Preparation of bovine pericardium with glycerin 98% presented efficiency in decellularization and conservation, maintaining its strength and avoiding bacterial growth. The mesenchymal stem cells obtained from bone marrow of adult Wistar rats, had capacity of proliferation. The majority of the cells was positive for the expression of surface antigens CD44, CD29 and CD99 and was negative for CD 34. In the differentiation trials, the same cells were able to differentiate into adipocytes and osteocytes. With 24 h from co-cultivating adhesion of mesenchymal stem cells in the membranes was observed. There was no foreign body reaction or contamination of surgical wounds and there was intense postoperative neovascularization on seven days. All animals presented omentum adherence, but no adherence to other organs.There was no statistically difference for the different times in macroscopic assessment: deposition of fibrous tissue, implant integration. The same occurred with the microscopic evaluations between the different treatment groups. The groups of immediate and later repair presented different responses to treatment. Discussion: The use of rats as animal model was satisfactory, being suitable for surgical procedures and assessments of the abdominal cavity. The different results obtained between groups of immediate repair and late repair corroborate with the idea that there is difference between induction and repair models in the same surgery or in different surgeries with the time interval between the two, suggesting the need for methodologies that simulate the hernias chronicity. The cells used were classified as mesenchymal stem cells, because it met all the criteria of Mesenchymal and Tissue Stem Cell Committee of the International Society of Celullar Therapy. The membranes conserved with glycerin 98% demonstrated biocompatibility, because there was no rejection or necrosis, infection or exacerbated infl ammation. However the muscle regeneration was not obtained over the membranes - and the methodological difference in other latest experiments about the membranes decellularization and the co-cultivating - can leads to conclusion that the cells attached to membranes were insufficient in number to obtain the desired result. These results suggest the need of new research studies or co-cultivating times and decellularization methods of bovine pericardium for association with mesenchymal stem cells.

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Background: Biological membranes demonstrate superiority over synthetic ones for its biocompatibility and strength in the reduction of abdominal hernias. Recents tissue engineering researches add mesenchymal stem cells to biological membranes with the purpose of obtaining additional cellular proliferation and consequent muscle regeneration, using biological membranes as cellular scaffolds. This article aimed to study the influence of mesenchymal stem cells in muscle regeneration in abdominal hernias, reduced with biological membranes. Materials, Methods & Results: Adult Wistar rats underwent abdominal hernia-inducing. They were divided into two groups as to the form of treatment for the reduction of hernia: stem cells associated with biological membranes or only biological membranes. After the treatment the macro and microscopic reviews were carried out in days seven, 14 and 60 postoperatively. Preparation of bovine pericardium with glycerin 98% presented efficiency in decellularization and conservation, maintaining its strength and avoiding bacterial growth. The mesenchymal stem cells obtained from bone marrow of adult Wistar rats, had capacity of proliferation. The majority of the cells was positive for the expression of surface antigens CD44, CD29 and CD99 and was negative for CD 34. In the differentiation trials, the same cells were able to differentiate into adipocytes

Vários tipos de implantes, naturais ou sintéticos, vêm sendo testados no reparo cirúrgico de hérnias. As membranas biológicas, ou arcabouços dérmicos descelularizados, apresentam reduzida formação de aderência entre o implante e as vísceras, diminuição da formação de fístulas, infecções e recorrências. Também apresentam resistência suficiente para suportar a pressão abdominal, evitando deiscências e eviscerações. [...]

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Actualmente, existe una necesidad sentida para el desarrollo de nuevos fármacos antimaláricos o de compuestos conocidos dirigidos contra blancos terapéuticos diferentes a los afectados por los medicamentos usuales. Son diversos los blancos que pueden ser aprovechados en Plasmodium, y la alteración de parámetros fisiológicos como el pH y el transporte de solutos pueden explicar la muerte del parásito cuando se usan compuestos antiplasmodiales, lo que representa una opción para el desarrollo de nuevas alternativas antiparasitarias. El propósito de esta revisión es por tanto, proporcionar una visión general de los efectos causados por esteroides, discutiendo el caso específico de los esteroides antiplasmodiales aislados de Solanum nudum y revisar dos procesos fisiológicos importantes en el parásito como posibles blancos terapéuticos, la modificación de permeabilidad del eritrocito infectado y el mantenimiento del pH intracelular de Plasmodium.

In malaria, attention has been posed to search or develop new antimalarial drugs or their modifications against different therapeutic targets in P. falciparum. Therapeutic targets such physiological parameters and solute transport have been proposed to kill the parasite and they represent an option for development of new drugs. We present a review on the effects of steroids, in particular the antiplasmodial steroids isolated from Solanum nudum, stressing two physiological Plasmodium processes such as the new permeability pathways on the infected red blood cells and the cytosolic pH regulation.

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Membranas biológicas são utilizadas em procedimentos cirúrgicos para fornecer um arcabouço e orientar o desenvolvimento de novos tecidos, mediante processos de reparação, que restabeleçam a estrutura e a função dos tecidos lesados. Assim, objetivou-se com este trabalho avaliar as características histológicas do centro tendíneo, da dura-máter, da fáscia lata, do pericárdio, do peritônio e da túnica vaginal de bovinos conservados em glicerina a 98% por período de 15, 30, 60 e 90 dias e a fresco. Para tanto, coletou-se fragmentos dessas membranas de dez bovinos mestiços, machos, com idade entre 30 e 36 meses, empregando-se técnicas de microscopia de luz convencionais. Não se observou diferenças marcantes quanto à integridade morfológica e estrutural dos elementos que constituem tanto as amostras do material a fresco quanto àqueles conservados em glicerina a 98%, que exibiram células mesoteliais e fibras conjuntivas sem alterações marcantes. Notou-se também o esmaecimento na coloração geral e maior evidenciação dos núcleos nas membranas conservadas em glicerina. Conclui-se que a glicerina é eficaz para conservação de membranas biológicas.

Biological membranes are used in surgical procedures to supply a skeleton and to guide the development of new tissues, under repairing processes, wich re-establish the structure and the function of injured tissues. So, with this study it was objectified to evaluate the histological characteristics of bovine tendinous center, dura mater, fascia lata, pericardium, peritoneum and vaginal tunic, fresh and 98% glycerin conserved for periods of 15, 30, 60 and 90 days. It was collected membranes’ fragments of ten crossbreed bovines, male, with age between 30 and 36 months, using histological conventional techniques. There was no marking differences as for the morphologic and stuctural integrity of the elements that constitutes the samples of fresh and 98% glycerin conserved material, evidencing mesothelial cells and connective tissue without intense alterations. It was still noticed a weakness in the general coloration and bigger evidenciation of the nucleous in the membranes conserved in glycerin. It can be concluded that glycerin is efficient to the conservation of biological membranes.

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Angiogenesis has been known to participate in several physiological and pathological processes. Experimental models have been utilized to demonstrate its importance. The aim of this study was to establish an angiogenesis model using two biological membranes (pericardium and amniotic membrane) preserved in glycerin. The membranes were implanted in a micropocket in the cornea of 63 rats. The pericardium was implanted into the right cornea and the amniotic into the left cornea of the same animal. The rats were sacrificed at 1, 3, 7, 15, 30 and 60 days after the surgical procedure and the specimens underwent histology examination. Although the pericardium was more effective to induce angiogenesis and for a long period of time when compared to the amniotic membrane, both membranes can be used as an angiogenesis model.

A angiogênese participa de inúmeros processos fisiológicos e patológicos. Vários modelos experimentais são encontrados na literatura mostrando a importância de seu estudo. Estabelecemos um modelo de angiogênese utilizando duas membranas biológicas -pericárdio e membrana amniótica eqüinas conservadas em glicerina, implantadas em microbolsa em córnea de 63 ratos. Implantou-se pericárdio na córnea direita e membrana amniótica na córnea esquerda, de tal forma que pudemos analisar os resultados em um mesmo animal. As córneas dos animais foram submetidos à análise histológica aos 1, 3, 7, 15, 30 e 60 dias de pós-operatório. A angiogênese induzida pelo pericárdio xenólogo foi mais intensa e mais duradoura que a membrana amniótica xenóloga. Concluímos que ambas as membranas biológicas induziram angiogênese corneana após terem sido implantadas no interior do estroma em ratos, podendo ser utilizadas como modelo de angiogênese.