Human Adipose-Derived Stem Cells Reduce Cellular Damage after Experimental Spinal Cord Injury in Rats.

Traumatic spinal cord injury (SCI) is a devastating condition without an effective therapy. Cellular therapies are among the promising treatment strategies. Adult stem cells, such as mesenchymal stem cells, are often used clinical research for their immunomodulatory and regenerative potential. This study aimed to evaluate the effect of human adipose tissue-derived stem cells (ADSC) infusion through the cauda equina in rats with SCI. The human ADSC from bariatric surgery was isolated, expanded, and characterized. Wistar rats were subjected to blunt SCI and were divided into four groups. Two experimental groups (EG): EG1 received one ADSC infusion after SCI, and EG2 received two infusions, the first one after SCI and the second infusion seven days after the injury. Control groups (CG1 and CG2) received infusion with a culture medium. In vivo, cell tracking was performed 48 h and seven days after ADSC infusion. The animals were followed up for 40 days after SCI, and immunohistochemical quantification of myelin, neurons, and astrocytes was performed. Cellular tracking showed cell migration towards the injury site. ADSC infusion significantly reduced neuronal loss, although it did not prevent the myelin loss or enhance the area occupied by astrocytes compared to the control group. The results were similar when comparing one or two cell infusions. The injection of ADSC distal to the injured area was shown to be a safe and effective method for cellular administration in spinal cord injury.

Adaptation Processes of the Remaining Jejunum or Ileum after Extensive Intestinal Resection.

PURPOSE: To compare the adaptation processes of the remaining jejunum or ileum after extensive intestinal resection in a growing animal model. MATERIALS AND METHODS: Forty 21-day old rats were divided into four groups: JG: remaining jejunum group - ileal enterectomy; IG: ileum remaining group - jejunum enterectomy; SHAM: sham-operated group - open-and-close laparotomy; and NO: non-operated animals. RESULTS: After 3 weeks, JG and IG animals had decreased weights comparing to SHAM and NO animals (p = 0.017 and p = 0.005, respectively). The histomorphometric analysis showed that in JG animals the villi were higher than in SHAM, NO, and IG animals (p = 0.007, p = 0.008, and p = 0.01), the depth of crypts in JG and IG animals was greater than in NO and SHAM animals (p = 0.03, p = 0.002, and p = 0.003 respectively), and muscle layer thickness of the jejunum of JG animals had values greater than SHAM and NO animals (p = 0.01 and p = 0.02, respectively). The Ki-67 expression in the ileum was higher in comparison with the jejunum (p = 0.014). The pro-apoptotic gene (Bax) expression was decreased in JG animals compared to IG, SHAM, and NO animals (p = 0.013, p = 0.024, and p = 0.021). The anti-apoptotic gene (Bcl-XL) expression was decreased in JG animals in comparison to IG and NO animals (p = 0.002 and p = 0.046) although it was increased in the colon of IG animals in comparison to JG, SHAM, and NO animals (p = 0.002, p = 0.001, and p = 0.001, respectively). The Bax/Bcl-XL ratio was higher in JG than in IG animals (p = 0.011). CONCLUSION: Adaptive responses seemed to be more effective in the ileum than in the jejunum.

Impact of Three Methods of Ischemic Preconditioning on Ischemia-Reperfusion Injury in a Pig Model of Liver Transplantation.

BACKGROUND: Ischemic preconditioning (IPC), either direct (DIPC) or remote (RIPC), is a procedure aimed at reducing the harmful effects of ischemia-reperfusion (I/R) injury. OBJECTIVES: To assess the local and systemic effects of DIPC, RIPC, and both combined, in the pig liver transplant model. MATERIALS AND METHODS: Twenty-four pigs underwent orthotopic liver transplantation and were divided into 4 groups: control, direct donor preconditioning, indirect preconditioning at the recipient, and direct donor with indirect recipient preconditioning. The recorded parameters were: donor and recipient weight, graft-to-recipient weight ratio (GRWR), surgery time, warm and cold ischemia time, and intraoperative hemodynamic values. Blood samples were collected before native liver removal (BL) and at 0 h, 1 h, 3 h, 6 h, 12 h, 18 h, and 24 h post-reperfusion for the biochemical tests: aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), creatinine, BUN (blood urea nitrogen), lactate, total and direct bilirubin. Histopathological examination of liver, gut, kidney, and lung fragments were performed, as well as molecular analyses for expression of the apoptosis-related BAX (pro-apoptotic) and Bcl-XL (anti-apoptotic) genes, eNOS (endothelial nitric oxide synthase) gene, and IL-6 gene related to inflammatory ischemia-reperfusion injury, using real-time polymerase chain reaction (RT-PCR). RESULTS: There were no differences between the groups regarding biochemical and histopathological parameters. We found a reduced ratio between the expression of the BAX gene and Bcl-XL in the livers of animals with IPC versus the control group. CONCLUSIONS: DIPC, RIPC or a combination of both, produce beneficial effects at the molecular level without biochemical or histological changes.

Laparoscopic Pancreatectomy in Rats: The Development of an Experimental Model.

INTRODUCTION: several pancreatectomy techniques in rats have been described and utilized for research concerning the pancreas endocrine and exocrine functions. However, we did not find a description of any kind of laparoscopic pancreatectomy in rats in the consulted databases. The objective of this study is to describe a laparoscopic splenic lobe pancreatectomy in rats. METHODS: ten Wistars rats weighting more then 300 g were operated for standardizing the laparoscopic pancreatosplenectomy technique, aided by previous descriptions of laparoscopic splenectomy and open pancreatectomy in rats. Adjustments have been progressively adopted for technical refinement. RESULTS: In five animals a low-cost rat laparoscopic set was used. In other five animals we used a standard laparoscopic set. Three rats died early due to different causes: transection of the gastroesophageal junction, hemorrhagic shock and inadvertent colonic injury. The postoperative period of the other seven rats was uneventful until the seventh postoperative day. DISCUSSION: laparoscopic distal pancreatectomy and splenectomy in rats is feasible and safe, even with a low-cost set, in which the results were alike the standard laparoscopic set.

Implementación de un modelo porcino de trasplante hepático en Chile / Implementation of a porcine liver transplant model in Chile

Resumen Objetivo: Presentar la implementación del primer modelo porcino de trasplante hepático (TH) en Chile y sus resultados. Material y Método: Se implementó un protocolo quirúrgico y anestésico en el contexto de una investigación en perfusión normotérmica hepática financiada por un Fondo Nacional de Desarrollo Científico y Tecnológico. Los cerdos fueron seleccionados por peso (35-40 kilos), en cada experimento se utilizó dos, donante y receptor, sometidos a procura y trasplante respectivamente. El análisis se realizó con estadística descriptiva. Resultados: Se realizaron 26 experimentos (marzo de 2018-octubre de 2019). El protocolo consta de 7 etapas: Preparación, Instrumentalización, Procura o Hepatectomía, Tiempo Anhepático, Etapa de Isquemia-Reperfusión, Monitorización y Eutanasia. Las primeras tres son similares en ambos cerdos, y desde la cuarta en adelante corresponde sólo al receptor. La supervivencia a la cirugía fue de 92,3% (24/26) y al seguimiento de 76,9% (20/26). La mortalidad se produjo por inestabilidad cardiovascular postreperfusión portal. El tiempo quirúrgico promedio fue de 170 min, y el tiempo anhepático de 33 min. La PAM cursó una baja postreperfusión con recuperación al final de la monitorización (67,4 mmHg media) y la tendencia en ph fue a acidosis al final del seguimiento (7,21 media). Se requirió drogas vasoactivas en 12 casos. Discusión: Logramos implementar un modelo experimental simplificado y reproducible de TH sin necesidad de circulación extracorpórea ni puente veno-venoso gracias a la estandarización de la técnica quirúrgica y de los cuidados perioperatorios. Conclusiones: La consolidación de un modelo experimental significa el primer paso en investigación preclínica de nuevas tecnologías asociadas al TH en Chile.

Objective: To Present the implementation of the first porcine model of liver transplant in Chile and its results. Materials and Methods: In the context of an investigation based on normothermic perfusion that was subsidized by the National Fund for Scientific and Technological Development, surgical and anesthetic protocols were implemented. Two pigs were selected by weight (35-40 kg), in which one was a donor and the other a receptor; submitted to procure and as a transplant recipient, respectively. The analysis was executed with descriptive statistics. Results: 26 experiments (June 2018-October 2019) were performed. The protocol includes 7 stages: Preparation, Instrumentalization, Procure or Hepatectomy, Anhepatic Time, Phase of Ischemia-Reperfusion, Monitoring and Euthanasia. The first three stages are similar in both pigs; meanwhile the last four are exclusive to the receptor. 92.3% (24/26) survived the surgery and 76.9% (20/26) survived the follow up, including the pilots. Average surgical time was 170 minutes, and the anhepatic time was 33 minutes. The mean arterial pressure decreased after the reperfusion and it improved towards the end of the monitorization (67,4 mmHg average) In the follow up, pigs presented acidosis (7.21 average). Vasoactive drugs were necessary in 12 experiments. Discussion: We managed to implement a simple and reproducible model of porcine liver transplant without extracorporeal circulation or veno-venous by-pass. This was possible due to the standardization of surgical technique and perioperative cares. Conclusions: The consolidation of porcine liver transplant model is the first step in pre-clinical research for the development of new technologies in liver transplant in Chile.

Morphological changes in the tissue structures afeter thermal burns on the background of using dermarm wound dressing

Over the last decade, the interest in using bacterial cellulose in medicine has increased. The article publishes the data about the efficiency of healing burn wounds in rabbits in experimental conditions with the use of the DermaRM wound dressing, compared to the traditionally used Panthenol ointment and the Branolind N salve dressing

Analgesia de animais de laboratório: responsabilidade dos comitês de ética e obrigação dos pesquisadores / Laboratory animals and analgesia: the responsibility of ethics committees and the obligations of researchers / Analgesia de animales de laboratorio: responsabilidad de los comités de ética y obligación de los investigadores

Objetivando avaliar projetos submetidos ao Comitê de Ética no Uso de Animais em relação ao uso de analgesia em cirurgia experimental, este trabalho avaliou 106 projetos, coletando as seguintes informações: metodologia do procedimento cirúrgico, utilização de analgesia, justificativa do não uso de analgésico e aplicação do grau de invasividade. Dos projetos avaliados, 64,2% empregaram técnica cirúrgica. Destes, 65,6% não utilizaram analgesia no pós-operatório, sendo a principal justificativa a de que o analgésico poderia alterar os resultados; em 17%, empregou-se a classificação de grau de invasividade de forma irregular. Assim, o estímulo e a divulgação dos conhecimentos relacionados a analgesia devem partir tanto dos comitês responsáveis quanto do corpo de pesquisadores.

The aim of the present study was to evaluate projects submitted to an Animal Research Ethics Committee regarding the use of analgesia in experimental surgery. A total of 106 projects submitted to the Animal Research Ethics Committee were evaluated and the following information was collected: methodology of the surgical procedure, use of analgesia, justification of the non-use of analgesia and application of the degree of invasiveness. Of the projects evaluated, 64.2% used surgical techniques, of which 65.6% did not use analgesia postoperatively, with the main reason being that the analgesic could alter the results. In 17% of cases the classification of the degree of invasiveness was used in an irregular manner. The stimulation and dissemination of analgesia-related knowledge must stem from both the ethics committees responsible and researchers.

Con el objetivo de evaluar los proyectos presentados al Comité de Ética en el Uso de Animales con respecto al uso de la analgesia en cirugía experimental de animales, este estudio evaluó 106 proyectos y obtuvo la siguiente información: la metodología de la intervención quirúrgica, el uso de la analgesia, la justificación de no utilizar analgésico y la aplicación del grado de invasividad. De los proyectos evaluados, un 64,2% empleó técnicas quirúrgicas, de los cuales un 65,6% no utilizó analgesia en el postoperatorio, justificando principalmente que el analgésico podría alterar los resultados, y en un 17% la clasificación del grado de invasividad se utilizó de manera irregular, por lo que la estimulación y la difusión de los conocimientos relacionados con la analgesia deben partir tanto de los comités responsables como del cuerpo de investigadores.

¿Existe infiltración grasa del cuádriceps en la lesión crónica del tendón patelar? / Is there fatty infiltration of the quadriceps in the chronic rupture of the patellar tendon?

No existen modelos que evalúen los cambios morfológicos musculares en roturas crónicas del aparato extensor de la rodilla. Objetivos: 1) Describir un nuevo modelo experimental de lesión crónica de tendón patelar; y 2) evaluar macroscópica e histológicamente la evolución, a través del tiempo, de la degeneración del cuádriceps con este modelo. Hipótesis: Existe fibrosis e infiltración grasa progresiva del cuádriceps a través del tiempo. Materiales y método: Se realiza transección del tendón patelar en 20 ratones BKS, machos, adultos, divididos en 4 grupos de 5 animales cada uno, siendo sacrificados a la 1era, 2da, 4ta y 12va semanas. A todos los ratones sacrificados se les extrajo el cuádriceps derecho (intervención) e izquierdo (control). Se realizó evaluación macroscópica, análisis morfométrico e histológico por 2 patólogos independientes y ciegos. Los resultados se analizaron estadísticamente con Test T de Student y Test de Wilcoxon (p<0,05). Resultados: Macroscopia: tejido amarillento en grupo intervenido con variables morfométricas alteradas progresivamente de manera significativa desde la 2da semana. Histología: infiltración grasa con atrofia numérica de fibras musculares, progresiva en el tiempo, significativa desde la 4ta semana, llegando a infiltración grasa severa a las 12 semanas con porcentaje de fibrosis menor al 6 por ciento en todos los casos.Conclusiones: Este nuevo modelo de lesión de tendón patelar se asocia a pérdida de continuidad persistente del aparato extensor con cambios estructurales del cuádriceps. Estos cambios incluyen atrofia muscular macroscópica e infiltración grasa con atrofia numérica de fibras musculares progresiva, significativa a partir de la 2da semana...

There are no models that evaluate the morphological changes of the muscles in chronic ruptures of the extensor apparatus of the knee. Objectives: 1) To describe a new model of chronic rupture of the patellar tendon; and 2) To macroscopically and histologically evaluate progressive quadriceps muscle degeneration. Hypothesis: There is progressive fibrosis and fatty infiltration of the quadriceps muscle. Materials and method: A complete transection was performed on the right patellar tendon of 20 male, adult, BKS mice, divided into 4 groups of 5 animals. The animals were sacrificed at the 1st, 2nd, 4th, and 12th week after the indicated procedure. After sacrificing the animals, both quadriceps muscles were resected and evaluated macroscopically, morphometrically, and histologically by 2 independent, blinded pathologists. Statistical analysis was performed using Student t test, and Wilcoxon's test (P<.05). Results:Macroscopy yellowish muscle tissue with significant progressive morphological changes beginning at week 2. Histology: progressive fatty infiltration with numerous atrophies of the muscle fibres, becoming significant after the 4th week, reaching severe fatty infiltration at week 12, with little fibrous tissue in less than 6 percent of the muscle. Conclusions: This new model of patellar tendon chronic rupture is associated with persistent discontinuity of the knee extensor mechanism and structural changes of the quadriceps muscle. These changes include muscle atrophy and progressive fatty infiltration beginning at the 2nd week after the injury...

CRITICAL ANALYSIS OF EXPERIMENTAL MODEL FOR STUDY OF ADHESIONS AFTER INCISIONAL HERNIAS INDUCED IN RATS’ AND REPAIR OF ABDOMINAL WALL WITH DIFFERENT BIOMATERIALS / ANÁLISE CRÍTICA DE MODELO EXPERIMENTAL PARA ESTUDO DAS ADERÊNCIAS APÓS HÉRNIAS INCISIONAIS INDUZIDAS EM RATOS E REPARO DA PAREDE ABDOMINAL COM DIFERENTES BIOMATERIAIS

Background: Adhesions induced by biomaterials experimentally implanted in the abdominal cavity are basically studied by primary repair of different abdominal wall defects or by the correction of incisional hernias previously performed with no precise definition of the most appropriate model. Aim: To describe the adhesions which occur after the development of incisional hernias, before the prosthesis implantation, in an experimental model to study the changes induced by different meshes. Methods: Incisional hernias were performed in 10 rats with hernia orifices of standardized dimensions, obtained by the median incision of the abdominal wall and eversion of the defect edges. Ten days after the procedure adhesions of abdominal structures were found when hernias were repaired with different meshes. Results:The results showed hernia sac well defined in all rats ten days after the initial procedure. Adhesions of the greater omentum occurred in five animals of which two also showed adhesions of small bowel loops besides the omentum, and another two showed liver adhesions as well as the greater omentum, numbers with statistical significance by Student's t test (p<0.05). Conclusion:Although it reproduces the real clinical situation, the choice of experimental model of incisional hernia repair previously induced implies important adhesions, with possible repercussions in the evaluation of the second operation, when different implants of synthetic materials are used.

Racional: As aderências induzidas por biomateriais implantados experimentalmente na cavidade abdominal são estudadas basicamente com o reparo primário de diferentes defeitos produzidos na parede abdominal ou com a correção de hérnias incisionais realizadas previamente, sem definição precisa do modelo mais adequado.Objetivo: Descrever as aderências que ocorrem após o desenvolvimento de hérnias incisionais, antes do implante de próteses, em modelo experimental para estudo de alterações induzidas por diferentes biomateriais.Métodos: Foram realizadas hérnias incisionais em 10 ratos, com orifícios herniários de dimensões padronizadas, obtidos pela incisão mediana da parede abdominal e eversão das bordas do defeito. Após 10 dias foram evidenciadas aderências de estruturas abdominais quando as hérnias foram reparadas com diferentes próteses.Resultados: Foi possível evidenciar hérnias com saco herniário bem definido em todos os ratos já no décimo dia após o procedimento inicial. Aderências do omento maior ocorreram em cinco animais, dos quais dois também apresentaram aderências de alças do intestino delgado além do omento, e outros dois aderências do fígado juntamente com o omento maior, números com significância estatística pelo teste t de Student (p<0,05).Conclusão: A opção por modelo experimental de reparo de hérnia incisional previamente induzida, embora mimetize a situação clínica real, implica em aderências importantes, com possível repercussão na avaliação da segunda operação, quando são utilizados diferentes implantes de material sintético.

Analysis of liver fragment subjected to autologous transplant at rat's retroperitoneum.

BACKGROUND: To investigate the regeneration process of autologous implants of liver on the retroperitoneum. METHODS: Thirty male Fisher rats were used divided in to group 1 (G1): studied 60 d after surgery; group 2 (G2): studied 90 d after surgery; group 3 (G3): studied 180 d after surgery; and group C (GC): animals without surgery. Hepatic fragment was processed for histologic and biochemical analysis. RESULTS: There was inflammatory infiltrate, diffuse hydropic degeneration, necrosis, and moderate fibrosis that reduced in direct relation to the postsurgical time. The concentration of albumin was different between GC and G1 and between G1 and G3 (P = 0.0007). The Catalase (CAT) was related to the time of surgery with GC being different when compared with G1, G2, and G3 (P < 0.0001). The oxidative stress measured through the thiobarbituric acid reactive substances lipid peroxidation was different between the GC and the G2 groups (P = 0.0381). CONCLUSIONS: The analysis made showed hepatic regeneration in the fragment subjected to autologous transplant at the retroperitoneum.

Treatment of bowel in experimental gastroschisis with a nitric oxide donor.

OBJECTIVE: To reduce the harmful effect of bowel exposure to amniotic fluid in gastroschisis, we used the nitric oxide (NO) donor S-nitrosoglutathione (GSNO) in an animal model of gastroschisis and assessed the ideal concentration for treatment of changes in bowel. STUDY DESIGN: Gastroschisis was surgically induced in rat fetuses on day 18.5 of gestation. The fetuses were divided into 5 groups (n = 12 animals/group): control (C), gastroschisis (G), gastroschisis + GSNO 5 µmol/L (GNO1), gastroschisis + GSNO 0.5 µmol/L (GNO2), and gastroschisis + GSNO 0.05 µmol/L (GNO3). On day 21.5 of gestation, fetuses were collected by cesarean delivery. Body and intestinal weight were measured and the bowels were either fixed for histometric and immunohistochemical study or frozen for Western blotting. We analyzed bowel morphometry on histological sections and expression of the NO synthase (NOS) enzymes by Western blotting and immunohistochemistry. Data were analyzed by analysis of variance or Kruskal-Wallis test when appropriate. RESULTS: Morphological and histometric measurements of weight, diameter, and thickness of the layers of the intestinal wall decreased with GSNO treatment, especially in the GNO3 group, when compared with the G group (P < .05). The expression of neuronal NOS, endothelial NOS, and inducible NOS decreased mainly in GNO3 group compared to the G group (P < .05), with no difference compared to C group (P > .05). CONCLUSION: Fetal treatment with 0.05 µmol/L GSNO resulted in significant improvement of bowel morphology in gastroschisis.

Lobectomía en ratas: modelo quirúrgico experimental: resultados en la densidad alveolar / Development of a rat model of lung lobectomy

Introducción: En la literatura está documentado que diferentes mamíferos tienen la capacidad de crecimiento compensatorio post resección pulmonar parcial. Objetivo: Crear un modelo quirúrgico de lobectomía en ratas, factible de desarrollar en nuestro medio, exponiendo algunas originalidades en relación a procedimientos de ventilación pulmonar, comunicando los resultados de la densidad alveolar obtenidos. Animales y Métodos: Se utilizaron 47 ratas Rattus norvegicus. Se aplicó como anestesia Atropina, Quetamina y Xilacina. Para el manejo de la vía aérea se diseñó: 1. Un sistema de ventilación con máscara facial tipo ambú evitando así la intubación traqueal. 2. Un protocolo de evaluación anestésica. 3. Un halo para oxigenar. 4. Se modificó un estetoscopio para realizar auscultación animal. Se practicó una lobectomía pulmonar derecha. Los sujetos fueron separados en Grupo Control (n = 7) y Grupo Experimental (n = 40), estos últimos, separados en cuatro grupos (n = 10, cada grupo), que fueron sacrificados en las semana 1, 2, 3 y 4. Resultados: Se logró 100 por ciento de sobrevida. El número de intersecciones alveolares mostró diferencias significativas entre el grupo control y el grupo experimental sacrificado en la semana 3 (p = 0,0016), con un menor número de alvéolos en el grupo experimental. Conclusión: Es factible realizar un modelo de cirugía pulmonar en ratas, con obtención de un 100 por ciento de sobrevida. Esto se logra por adecuaciones en el manejo pre e intra-operatorio. No se pudo demostrar que exista aumento significativo en el número de alvéolos, posiblemente por el bajo número de casos realizados.

Background: Surgical lung resection is required for multiple pulmonary diseases. After these procedures, the lung experiences a compensatory growth, which can be studied in animal models such as rats. Aim: To develop a surgical model of lung lobectomy in rats. Material and Methods: Forty seven rats of the strain Rattus norvegicus were used. Animals were anesthetized with atropine, ketamine and xylacine. The airway was managed with a facial mask to avoid intubation. An anesthetic evaluation protocol was followed and animals were oxygenated using a cephalic veil. Forty rats were subjected to a right lobectomy and seven animals were sham operated. Rats subjected to lobectomy were sacrificed at one, two, three and four weeks after operation. Results: All operated rats survived. There were significant differences in the number of alveolar intersections among rats subjected to lobectomy and sacrificed at three weeks compared to sham operated animals, with a lower number of alveoli among the former. Conclusions: We were able to develop the model of lobectomy, however we failed to demonstrate a compensatory growth among rats subjected to lobectomy.

Protoporphyrin fluorescence induced by methyl-ALA in skin healing.

BACKGROUND: Estimation of the time period that precedes an injury is critical in forensic medicine. However, there is no reliable method that can be used to evaluate the oldness of a lesion. The aim of this work is to develop a fluorimetric method that can be used to follow the aging process of lesions by applying methyl-ALA (MAL) on wounds and by quantifying protoporphyrin IX (PPIX) fluorescence during the healing process. We also aim to understand the changes in PPIX fluorescence by establishing a correlation with histological evaluations during the healing process. METHODS: Standardized linear wounds were made on the dorsum of 72 mice, which were divided in control (MAL -) and experimental (MAL +) groups. In vivo fluorescence spectra (FS) were collected from normal and wound skin sites of control and experimental groups, corresponding to four groups of FS spectra: (a) FS of skin wound after MAL (+/+); (b) FS of normal skin after MAL (-/+); (c) FS of skin wound without MAL (+/-) and (d) FS of normal skin without MAL (-/-). Animals were monitored periodically for 3 months and euthanized. Tissue specimens were processed for histological analysis using design-based stereological methods. Serial cross-sections were analyzed to evaluate the organization of the dermis and epidermis, collagen deposition and cellular proliferation. RESULTS: FS of skin wound with MAL (+/+) showed an expressive intensity increase from the beginning of the experiment to the 34th day, with maximum fluorescence being observed on the ≈ 11 th day after wounding. There was preferential PPIX accumulation in healing sites as compared to adjacent normal skin (+/-) in the early stage of healing. Histological findings allowed correlation of the fluorescence increase mainly with cell proliferation. The drastic decrease in the FS intensity observed in the end of the healing process was correlated with the decrease in the proliferation rate as well as with the presence of new extracellular fibrous materials. CONCLUSIONS: In the mice wound-healing model tested here, it was possible to distinguish whether the injury was in early or advanced stages by using PPIX fluorescence induced by MAL. We conclude that this method is a promising approach to evaluate the age of skin wounding and we hope this work will stimulate human studies to allow this technique to become standardized in forensic medicine.

Combined approach for experimental Oto-neurosurgical procedures.

BACKGROUND: Experimental procedures will continue to be a key element while going through the learning curve in the use of the endoscope and minimally invasive procedures. We describe the technical procedure of an experimental approach to middle ear in New Zealand rabbits through external auditory canal and its relevance as an ideal model to study graft materials and serve as a training tool for potential applications in otoneurology. METHODS: A group of 28 adult New Zealand rabbits were subjected to an experimental myringoplasty, combining the transmeatal and retroauricular approach with endoscopic assistance and microsurgical technique. The different anatomical steps and systematization of the complete experimental procedure are described. RESULTS: An experimental approach to middle ear live model and basic anatomic description was successfully used, standardizing the ideal technique. The eardrum could regenerate with no complications and with functional preservation in all the myringoplasty cases. This strategy involves a safe combined approach to the tympanic membrane and others neurosurgical as transcochlear and translaberyntic approaches and is useful as a test of other experimental procedures to evaluate biomaterials to repair the eardrum currently studied. This experimental myringoplasty model also facilitates functional tests such as impedanciometry and the endoscopic follow-up of the whole process. CONCLUSIONS: The method described to perform an experimental myringoplasty (type I tympanoplasty) in a New Zealand rabbit is an option to be used as a basic model to study the behavior of the graft in the tympanic membrane. Also, basic concepts for the use of combined instrumentation are established in the treatment of eardrum lesions, as a refinement of the technical training application in microsurgery and assisted endoscopy in the transcochlear and translaberintic approaches and otoneurology areas.

Idade dos ratos versus idade humana: qual é a relação? / Rat's age versus human's age: what is the relationship?

RACIONAL: Milhões de ratos são empregados anualmente em pesquisas e no ensino. A exata relação entre a idade dos ratos, comparada com a idade dos humanos ainda é assunto de discussão e controvérsias. OBJETIVO: É revisar a literatura, analisando a idade dos ratos em comparação com a idade dos homens. MÉTODOS: Foram revisadas as publicações existentes sobre o assunto contidas nas bases Medline/Pubmed, Scielo, Biblioteca Cochrane e Lilacs cruzando os descritores ratos, cirurgia experimental e fisiologia. RESULTADOS: Ratos desenvolvem rapidamente durante a infância e se tornam sexualmente maduros com cerca de seis semanas de idade, mas atingem a maturidade social cinco a seis meses mais tarde. Na idade adulta, a cada mês do animal é aproximadamente equivalente a 2,5 anos humanos. Vários autores realizaram trabalhos experimentais em ratos e afirmaram existir correspondência de 30 dias de vida do homem para cada dia de vida do rato. CONCLUSÃO: As diferenças na anatomia, fisiologia, desenvolvimento e fenômenos biológicos devem ser levados em consideração quando são analisados os resultados de qualquer pesquisa em ratos em que a idade é um fator crucial. Cuidado especial é necessário ser tomado quando os estudos efetuados pretendem produzir correlação com a vida humana. Para isso, atenção especial é necessária para verificar a fase em dias do animal e sua correlação com os anos em humanos.

BACKGROUND: Millions of mice are used annually in research and teaching. The exact relationship between age of the animals compared with the age of humans is still subject to discussion and controversy. OBJECTIVE: Literature review analyzing the age of rats in comparison with men age. METHODS: Were reviewed the existing publications on the subject contained in Medline / Pubmed, Scielo, The Cochrane Database of Systematic Reviews and Lilacs crossing the headings rats, experimental surgery and physiology. RESULTS: Rats rapidly develop during childhood and become sexually mature at about six weeks old, but reach social maturity five to six months later. In adulthood, every month of the animal is approximately equivalent to 2.5 human years. Several authors performed experimental studies in rats and estimated 30 days of human life for every day life of the animal. CONCLUSION: The differences in anatomy, physiology, development and biological phenomena must be taken into consideration when analyzing the results of any research in rats when age is a crucial factor. Special care is necessary to be taken when the intention is to produce correlation with human life. For this, special attention is needed to verify the phase in days of the animal and its correlation with age in years of humans.

Use of a type IIB external skeletal fixator in experimental tarsocrural arthrodesis in dogs

The aim of the present study was to evaluate the usefulness of type IIb external skeletal fixators with a transarticular pin in experimental tarsocrural arthrodesis. Twelve adult mongrel dogs of both sexes, ranging in age from two to five years and weighing 12 to 25kg, were used. The configuration of the fixator consisted in the application of a transarticular Steinmann pin and of centrally threaded pins to the proximal portion of the tibia and calcaneus and to the distal portion of the metatarsal bones. In addition, Schanz pins were inserted into the medial and lateral side of the tibia and into the medial side of the metatarsal bones. Radiographs were taken 15; 30 and 45 days after surgery. Bone fusion of the treated joints were observed at 30 days in all animals, and the implants were removed after 45 days. Loosening of the centrally threaded pins was observed in all groups, especially for those applied to the calcaneus. The configuration of the external fixator proposed here was found to be satisfactory in terms of bone union for all joints during the same period, irrespective of the weight of the animal.

O objetivo com este trabalho foi avaliar a utilização de fixadores esqueléticos externos do tipo IIb com pino transarticular em artrodeses tarsocrurais experimentais. Foram empregados 12 animais da espécie canina, machos e fêmeas, sem raça definida, adultos, com idades entre dois e cinco anos, peso entre 12 e 25kg. A configuração do fixador foi estabelecida com a aplicação de pino de Steinmann transarticular, pinos com rosca central na porção proximal da tíbia, calcâneo e distal nos metatarsianos, pinos de Schanz, também, foram aplicados na face medial e lateral da tíbia e na face medial dos metatarsianos. Os intervalos de tempo para as análises radiográficas foram 15; 30 e 45 dias do pós-cirúrgico. Foram observadas fusão das articulações que sofreram artrodese aos 30 dias em todos os animais, sendo, os implantes removidos aos 45 dias. Houve afrouxamento dos pinos de rosca central em todos os grupos, sobretudo os pinos aplicados no calcâneo. A configuração do fixador externo proposto por este trabalho, mostrou-se satisfatória para a união óssea de todas as articulações em um mesmo período, independentemente do peso do animal.

Aspectos fundamentais da experimentação animal - aplicações em cirurgia experimental / Fundamental aspects on animal research as applied to experimental surgery

Com o objetivo de contribuir à pesquisa em cirurgia experimental, este artigo apresenta uma análise dos principais parâmetros exigidos a serem observados pelos comitês internacionais e nacionais de ética e bem-estar animal, cujo cumprimento é pré-requisito para publicação em periódicos arbitrados de circulação internacional. A padronização da genética, do estado sanitário e do ambiente das espécies de animais Mus musculus (camundongos), Rattus norvegicus (ratos), Oryctolagus cuniculus (coelhos) e Sus scropha domesticus (suínos), a observação de condições adequadas no transporte, aclimatação, enriquecimento do ambiente, treinamento de técnicos em experimentação animal, gestão de informação, biossegurança, dieta, anestesia, cuidados pós-operatórios, analgesia e eutanásia, aliados a projetos de pesquisa bem planejados são apresentados como etapas fundamentais para a obtenção de resultados com alto grau de acuidade, alto nível de reprodutibilidade e precisão.

This study aimed to present the general principles for experiments performed on laboratory animals as required by international and national ethical committees on animal welfare. Compliance to these principles is a prerequisite for publication in international journals. Details of genetic, sanitary and environmental standards, transportation, acclimation, environmental enrichment, appropriate education and training of all those involved in handling of live animals, information management strategy, biossecurity, diet, anesthesia, analgesia, postoperative care and euthanasia for Mus musculus (mice), Rattus norvegicus (rat), Oryctolagus cuniculus (rabbit) and Sus scropha domesticus (pig) combined with well planned biomedical research are fundamental to increase the accuracy, reproducibility and precision of the experimental results.

Tendências em experimentação animal / Trends in animal experimentation

Introdução: A busca do entendimento de fatores etiológicos, mecanismos e tratamento das doenças tem levado ao desenvolvimento de vários modelos animais nas últimas décadas. OBJETIVO: Esse artigo tem por objetivo discutir aspectos relacionados a modelos animais de experimentação, escolha do animal e tendências atuais nesse campo em nosso país. Além disso, esse estudo buscou avaliar o espaço ocupado por artigos experimentais em revistas médicas. Métodos: Foram selecionadas cinco revistas brasileiras, indexadas na LILACS, SciELO, MEDLINE, e recentemente incorporadas pelo Institute for Scientific Information Journal of Citation Reports. Foram selecionados pelo resumo ou abstract todos os artigos publicados nessas revistas, nos anos de 2007 e 2008, que empregaram modelos animais. Resultados: Do total de 832 artigos publicados no período pelas revistas analisadas, foram selecionados 92 (11,1 por cento) que empregavam animais de experimentação. O número de artigos experimentais variou de 5,2 por cento a 17,9 por cento do conteúdo global da revista. Nas instruções aos autores de quatro (80 por cento) das revistas avaliadas, havia referência explícita aos princípios éticos na condução de estudos com animais. Os modelos animais induzidos representaram 100 por cento dos artigos analisados neste estudo. O rato foi o animal mais empregado nos artigos analisados, sendo utilizado em 78,3 por cento deles. Conclusões: O presente estudo poderá fornecer subsídios para adoção de políticas editoriais futuras relativas à publicação de artigos originários de pesquisa animal na RBCCV.

Introduction:: The search of the understanding of etiological factors, mechanisms and treatment of the diseases has been taking to the development of several animal models in the last decades. OBJECTIVE: To discuss aspects related to animal models of experimentation, animal choice and current trends in this field in our country. In addition, this study evaluated the frequency of experimental articles in medical journals. Methods: Five Brazilian journals indexed by LILACS, SciELO, MEDLINE, and recently incorporate for Institute for Scientific Information Journal of Citation Reports were analyzed. All the papers published in those journals, between 2007 and 2008, that used animal models, were selected based on the abstracts. Results: Of the total of 832 articles published in the period, 92 (11.1 percent) experimentation papers were selected. The number of experimental articles ranged from 5.2 percent to 17.9 percent of the global content of the journal. In the instructions to the authors, four (80 percent) journals presented explicit reference to the ethical principles in the conduction of studies with animals. The induced animal models represented 100 percent of the articles analyzed in this study. The rat was the most employed animal in the analyzed articles (78.3 percent). Conclusions: The present study can contribute, supplying subsidies for adoption of future editorials policies regarding the publication of animal research papers in Brazilian Journal of Cardiovascular Surgery.

Análisis descriptivo de la reparación ósea asociada a implantes dentales endóseos instalados en perros con técnica sumergida en dos períodos de evaluación / Descriptive analyses of osseous repair related to endosseous dental implant installed in dogs with submerged technique in two evaluation period

Los implantes oseointegrados forman parte de la práctica clínica en diferentes disciplinas de la rehabilitación funcional y estética del hombre donde el área de la odontología no es una excepción; de esta forma, los implantes dentales son una respuesta a la gran demanda de paciente con edentulismo parcial o total. Existe una importante y creciente investigación en implantología, siendo imperativo reconocer las características histológicas de la reparación ósea cuando son instalados implantes dentarios. El objetivo de esta investigación es reconocer las características histológicas descriptivas de la reparación ósea asociada a la instalación de implantes dentales en dos periodos de evaluación. El modelo experimental utilizado en este estudio correspondió al de cinco perros sometidos a la exodoncia de premolares mandibulares bilaterales. Después de tres meses fueron instalados implantes bilaterales con dos diseños diferentes y con diferentes protocolos de carga. Los sacrificios de los animales fueron realizados después de tres y seis semanas de instalados los implantes. El estudio histológico descriptivo se desarrolló en el tejido adyacente a implantes instalados con técnica sumergida. Se observaron características de reparación ósea en los dos periodos de evaluación. El periodo de tres semanas presento tejido mineralizado en contacto con el implante y tejido conectivo no mineralizado en aumento desde la región superior hacia la inferior. Las regiones de reparación ósea fueron relacionadas con fenómenos de angiogénesis adyacentes. A las seis semanas se observo una mayor formación ósea, reemplazando las áreas de tejido conectivo no mineralizado por tejido mineralizado. Se observo también tejido óseo maduro con canales de Havers bien constituidos. Concluimos que existe una secuencia biológica de reparación ósea respetada en los dos periodos de evaluación, donde después de seis semanas es posible observar un tejido óseo bien constituido, teóricamente ...

Osseointegrated implants are a part of clinical practice in different areas of the aesthetic and functional human rehabilitation where dentistry is not an exception; being like that, dental implants are a responses to great necessity of patient with partial or total dental lost. Exist an important and crescent research in implantology, being very important to recognize the histological characteristic of the osseous repair when dental implant are installed. The aim of this research was to recognize the histological descriptive characteristic of the osseous repair in two evaluation period. The experimental model in this research was five dogs submitted to dental extraction of mandibular bilateral bicuspid. After three month were installed bilateral implants with two implants design and different load protocols. The animals' sacrifices were realized three and six weeks after implants installation. The histological evaluation was realized in a tissue of implant with submerged techniques. Was observed osseous repair characteristic for two evaluation period. For three weeks period was observed mineralized tissue in contact with implant and non mineralized connective tissue in increase from superior to inferior areas. Reparation areas were related to adjacent angiogenic phenomena. For sex weeks period, was observed a major osseous formation, change connective tissue for mineralized tissue. Was observed too matures osseous tissue with well formed Havers channel. We conclude that exist a biological sequence of osseous repair present for a two evaluation period, where in a sex weeks is observed osseous tissue with good definition, theoretically capable for stress support.