Évaluation de l’impact de pansements biologiques humains produits par génie tissulaire sur la guérison de plaies cutanées murines

L’étude de la guérison des plaies à l’aide de substituts produits par génie tissulaire est un domaine en plein essor. Dans ces travaux, les effets de pansements biologiques produits en laboratoire à partir de cellules souches/stromales du tissu adipeux (CSTA) différenciées ou non en adipocytes ont été évalués sur des plaies cutanées in vivo. Un modèle de souris possédant un épiderme fluorescent a permis de démontrer que les plaies traitées avec les pansements biologiques guérissent plus rapidement que les plaies non traitées, et ce, de manière indépendante de la réépithélialisation. Une augmentation de la formation du tissu de granulation et une angiogenèse accrue ont également été observées dans les groupes traités. Ces résultats établissent que les substituts contenant des CSTA ou des adipocytes fonctionnels favorisent la réparation tissulaire. À terme, ces travaux pourraient mener au développement de nouvelles indications cliniques pour le traitement des ulcères cutanés.

Contribution de l'hypoxie à la cicatrisation cutanée anormale chez le cheval : méthodes physiques d'évaluation

La guérison des plaies cutanées appendiculaires chez le cheval, à la différence de celle des plaies corporelles, se complique régulièrement. Un retard de cicatrisation s’y observe et un tissu de granulation exubérant tend à s’y développer, le tout menant à une cicatrice pathologique hypertrophiée. La pathogénie exacte du tissu de granulation exubérant chez le cheval demeure inconnue à ce jour. Une hypoxie tissulaire pourrait favoriser son développement tout comme elle semble contribuer au développement de cicatrices cutanées pathologiques similaires observées chez l’Homme. L’objectif de cette étude était d’évaluer la perfusion vasculaire et la disponibilité locale en oxygène de plaies cutanées appendiculaires et corporelles en cours de cicatrisation normale et pathologique chez le cheval, à l’aide de la thermographie infrarouge et de la spectroscopie par réflectance dans le proche infrarouge. Six juments âgées de 3 à 4 ans ont été utilisées. Trois plaies cutanées ont été créées à l’aspect dorso-latéral du canon des membres thoraciques (plaies appendiculaires), et sur la paroi costale de l’un des hémithorax (plaies corporelles). Chez chaque jument, un canon a été aléatoirement bandé dans le but d’induire la formation de tissu de granulation exubérant dans les plaies s’y trouvant, tel que rapporté. La perfusion vasculaire et la disponibilité locale en oxygène ont été évaluées séquentiellement par thermographie infrarouge et spectroscopie par réflectance dans le proche infrarouge pour chaque plaie de chaque site (thorax; membre bandé; membre non bandé) au cours du processus de cicatrisation cutanée. Un modèle linéaire à doubles mesures répétées associé à une correction séquentielle de Bonferroni a révélé des différences significatives de perfusion vasculaire et de disponibilité locale en oxygène entre les plaies appendiculaires et corporelles. Ainsi la perfusion vasculaire et la disponibilité locale en oxygène étaient significativement plus élevées dans les plaies corporelles (P<0.05) et la perfusion vasculaire était significativement plus élevée dans les plaies appendiculaires non bandées que dans celles bandées (P<0.05). Nous avons récemment rapporté une plus grande occlusion de la micro-vascularisation au niveau des plaies appendiculaires chez le cheval. Nous rapportons maintenant que la perfusion vasculaire et la disponibilité locale en oxygène sont significativement inférieures dans les plaies appendiculaires, en particulier lorsqu’un tissu de granulation exubérant s’y développe. Compilés, ces résultats sous-tendent l’hypothèse que les plaies appendiculaires souffrent d’une altération de la perfusion vasculaire à l’origine possible d’une hypoxie tissulaire qui pourrait favoriser une cicatrisation cutanée anormale, telle la formation d’un tissu de granulation exubérant.

Contribution de l’hypoxie et du facteur hif1a à la guérison cutanée chez le cheval

Le cheval est souvent victime de plaies traumatiques, dont la guérison est fréquemment problématique, et ce, principalement quand la plaie survient sur le membre. Il est courant de voir chez le cheval le développement d’un tissu de granulation exubérant ou « bouton de chair », qui mène à une cicatrisation excessive due à la surproduction de tissu fibreux. Ce tissu cicatriciel, non épithélialisé, est caractérisé par une occlusion au niveau de la microcirculation due à l’hypertrophie des cellules endothéliales, qui laisse supposer la présence d’hypoxie tissulaire. Une hypoxie relative a effectivement été mesurée par spectroscopie dans le proche infrarouge au niveau des plaies appendiculaires prédisposées au développement de tissu de granulation exubérant, par rapport aux plaies corporelles. De plus, une étude thermographique a révélé un patron spatial similaire de la perfusion. Au niveau moléculaire, la littérature rapporte que le facteur de transcription «hypoxia inducible factor» (HIF) est à l’origine de plusieurs changements dans les niveaux d’expression de divers gènes régulés par l’hypoxie. L’objectif du présent projet de recherche était de définir la contribution de l’hypoxie à la guérison cutanée chez le cheval. Le premier volet (in vivo) du projet visait à mesurer l’expression protéique temporelle du HIF1A dans des échantillons tissulaires en provenance de plaies cutanées guérissant normalement et d’autres développant une cicatrisation excessive, selon divers sites anatomiques (tronc, membre). Les résultats obtenus suggèrent que la mesure de HIF1A, dans les échantillons pluricellulaires de cette étude, reflète l’épithélialisation de la plaie plutôt que les niveaux d’oxygène tissulaire. En effet, le HIF1A semble réguler l’homéostasie et la prolifération des kératinocytes. Le second volet (in vitro), consistait en la mise en culture de fibroblastes dermiques équins provenant du tronc ou du membre, en condition de normoxie ou d’hypoxie (à 1% d’O2 ou à l’aide d’un mimétique, le CoCl2) afin d’en étudier le comportement (capacités de prolifération et de synthèse protéique). Les résultats obtenus soutiennent une contribution de l’hypoxie à la cicatrisation extensive chez le cheval puisque l’hypoxie favorise la prolifération des fibroblastes en plus d’encourager la synthèse de collagène de type 1 et de diminuer la synthèse de la métalloprotéinase de type 2. Les changements observés semblent dépendre de facteurs extrinsèques (environnementaux) car les fibroblastes dermiques se comportent de façon similaire indépendamment de la provenance anatomique. En somme, les deux volets de l’étude ont permis d’élucider une part des mécanismes sous-jacents à la formation du tissu de granulation exubérant lors de guérison cutanée chez le cheval. La poursuite des recherches dans ce domaine mènera à une meilleure compréhension de la pathologie et ainsi, permettra de développer des méthodes de traitement spécifiques à la condition.

Lesiones laríngeas post-intubación en adultos y su relación con el tiempo de intubación: Estudio de nasofibrolaringoscopia diagnóstica

Objetivo: Determinar las lesiones laríngeas post-intubación endotraqueal en la unidad de cuidado intensivo (UCI) y cirugía ambulatoria y evaluar su asociación con respecto al tiempo de intubación y otras variables clínico-demográficas en un hospital universitario. Materiales y métodos: Estudio de cohorte analítico incluyendo 60 pacientes (30 de UCI y 30 de cirugía ambulatoria) a quienes se les realizó nasofibrolaringoscopia a las 24 horas post-extubación y a las 3 semanas de control y se registran las lesiones laríngeas encontradas. Resultados: En la primera endoscopia el 70% de los pacientes de cirugía ambulatoria presentaban al menos una lesión laríngea con un promedio de duración de intubación de 0.12 días DS±0.05 desapareciendo todas las lesiones en la segunda endoscopia. En el análisis del grupo de UCI se encontraron lesiones en el 76.6% de los pacientes con un promedio de duración de intubación de 6.0 días DS±3.3. La presencia de edema en pacientes con intubación prolongada por más de 6 días mostró diferencias estadísticamente significativa con respecto al grupo con menos días de intubación (RR 3.048, 95% IC 0.9-9.3, P=0.03) al igual que con antecedente de EPOC (P=0.032) y APACHE II mayor de 17 (RR 1.8, 95% IC 1.114-3.0, P=0.013). EPOC tiene una diferencia estadísticamente significativa con hiperemia (P=0.02) y granuloma (P=0.019). En la segunda endoscopia se encontró mayor frecuencia de hiperemia en los pacientes con intubación prolongada (>6 días) con una diferencia estadísticamente significativa (P=0.01). Conclusión: La intubación prolongada se encuentra asociada a la aparición edema e hiperemia en la laringe. EPOC y puntaje superior de APACHE II se relacionan con hiperemia y granulomas glóticos.

Evaluation of the Larval Therapy in the Healing Process of Infected Wounds with Pseudomonas Aeruginosa in Rabbits

Introduction. During the last two decades the larval therapy has reemerged as a safe and reliable alternative for the healing of cutaneous ulcers that do not respond to the conventional treatments. Objective. To evaluate the use of the larvae of Lucilia sericata as a treatment for infected wounds with Pseudomonas aeruginosa in an animal model. Materials and methods. Twelve rabbits were randomly distributed in 3 groups: the first group was treated with larval therapy; the second was treated with antibiotics therapy and to the third no treatment was applied, therefore was established as a control group. To each animal a wound was artificially induced, and then a suspension of P. aeruginosa was inoculated into the lesion. Finally, every rabbit was evaluated until the infection development was recognized and treatment was set up for the first two groups according with the protocols mentioned above. Macroscopic evaluation of the wounds was based on the presence of edema, exudates, bad odor, inflammation around the wound and the presence of granulation tissue. The healing process was evaluated by monitoring histological changes in the dermal tissue. Results. Differences in the time required for wound healing were observed between the first group treated with larval therapy (10 days) and the second group treated with conventional antibiotics therapy (20 days). Conclusion. The L. sericata larva is and efficient tool as a therapy for infected wounds with P. aeruginosa.

Colesteatomas adquiridos : análise comparativa da perimatriz entre pacientes pediátricos e adultos

Introdução: Os colesteatomas podem ocorrer tanto em crianças como em adultos, porém nas crianças pareceriam ter um crescimento mais agressivo e extenso. A atividade das colagenases poderia explicar este perfil. Objetivo: Comparar, histologicamente, a perimatriz de colesteatomas adquiridos de crianças com os de adultos. Métodos: Foram estudados 74 colesteatomas, 35 pediátricos, coletados em cirurgias otológicas, fixados em formol 10% e processados pelas técnicas histológicas habituais. Foram preparadas uma lâmina em Hematoxilina-Eosina (HE) e outra em Picrossírios, de cada amostra, e analisadas ao microscópio óptico. A leitura foi “cega”, efetuada por meio de imagens digitais, no software ImagePro Plus. A análise estatística foi realizada através dos coeficientes de correlação de Pearson e Spearman e dos testes t e χ2, sendo considerados como estatisticamente significativos os valores de P<0,05. Resultados: Dos 74 colesteatomas coletados, 17 - sete do grupo pediátrico e dez do adulto - foram excluídos por não terem presença de matriz e perimatriz nas lâminas processadas. A média±dp da idade, no grupo pediátrico, foi de 12,85±3,63; e no adulto, 33,69±13,10. Na análise histológica, o número médio de camadas de células epiteliais da matriz foi igual a oito, nos dois grupos, 60% das amostras apresentavam inflamação, de moderada a acentuada; quanto à fibrose, nas crianças, 71,4% e nos adultos, 62,1%; o granuloma apareceu em 10,7% e 13,8%, respectivamente; a presença de epitélio cubóide simples delimitando a perimatriz foi encontrada em 29% dos infantis e 14% dos adultos, entretanto, nenhuma dessas variáveis apresentou diferença estatisticamente significativas quando comparadas por faixa etária (P>0,05). Quanto à espessura da perimatriz, no grupo pediátrico, as medianas (intervalo interquartil) dos parâmetros foram: média=79 (41 a 259); mediana=77 (40 a 265); soma=1.588 (831 a 5.185); delta=82 (44 a 248); mínimo=53 (16 a 165) e máximo=127 (64 a 398); já no grupo de adultos foram: média=83 (26 a 174); mediana=68 (30 a 181); soma=1.801 (558 a 3.867); delta=92 (45 a 190); mínimo=27 (12 a 100) e máximo=136 (53 a 280). O coeficiente de Spearman mostrou correlação inversa, moderada, entre a espessura da perimatriz e a idade; também houve correlação, forte, entre a espessura da perimatriz e o número de camadas da matriz, porém não houve correlação entre essa com a idade. Conclusão: Histologicamente, a perimatriz de colesteatomas adquiridos, de crianças e adultos, vista à microscopia óptica, apresenta-se como um tecido conjuntivo denso de espessura variável (intra e interpacientes), que, por vezes, exibe infiltrado inflamatório linfoplasmocitário e/ou tecido de granulação e reação de corpo estranho; em alguns casos é delimitada em plano profundo por epitélio cubóide simples. Há correlação inversa, de fraca a moderada, entre o tamanho da perimatriz, medida em micrômetros e a idade do paciente na data da cirurgia. O grau de inflamação da perimatriz apresenta correlação, de moderada a forte, com a espessura da perimatriz. As espessuras da matriz e da perimatriz estão fortemente correlacionadas.

Reparação de feridas cutâneas de roedores da espécie Calomys callosus, tratadas com hidrocarboneto alifático: aspectos morfométricos, morfológicos e histológicos

O efeito cicatrizante do hidrocarboneto alifático foi pesquisado através da aplicação diária em feridas cutâneas, cirurgicamente provocadas, em roedores da espécie Calomys callosus. As feridas dos animais foram analisadas sob os aspectos macroscópicos e histológicos transcorridos 3, 7, 14 e 21 dias de tratamento e comparado com o uso de solução fisiológica a 0,9%. O hidrocarboneto alifático antecipou a cicatrização ao diminuir a umidade, aumentar a formação do tecido de granulação e a neovascularização, conduzindo à reepitelização.

Pitiose cutânea equina de localização atípica tratada topicamente com solução de anfotericina B e DMSO

Background: Cutaneous lesions by Pythium insidiosum infection are commonly observed in horses, especially in those living at flooded environments. Equine pythiosis is characterized by the development of tumoral masses that are frequently located at distal limbs, ventral abdomen, thorax, breast and face. The lesions are usually granulomatous, serosanguineous and ulcerated, most often destroyed by self-mutilation due to the intense pruritus. The proposed treatment includes surgical excision followed by antifungal drugs administration, which can be done systemically or topically. Amphotericin B and dimethyl sulfoxide (DMSO) in association has been successfully used for cutaneous pythiosis topical treatment due to the DMSO property to carry any substance through plasmatic membranes.Case: The present report concerns a 12-year-old mixed breed gelding presenting with self-mutilation of a tumoral mass located at the left flank. The owners reported that the horse had initially presented a small wound that had evolved to a 20-cm in diameter mass in 4 weeks. Tissue samples were collected, processed and stained by the Gomori's methenamine silver (GMS) method. The histopathological analysis revealed Pythium insidiosum hyphae in a granulomatous tissue, especially located at peripheral region, where kunkers were present. Surgical excision of the mass followed by cauterization was indicated as initial treatment, and due to financial reasons, the owners elected only the topical antifungal therapy to control the fungus infection after surgery. Flunixin meglumine was also administrated for five days aiming the control of pain and inflammation. The wound was cleaned with povidone-iodine solution and rinsed with a solution containing, 50 mg, of amphotericin B in 10 mL of sterile water and 10 mL of DMSO. This procedure was carried Out twice a day. The wound healed fast due to an excellent centripetal epithelialization. and the horse was discharged after 64 days showing only 5% of the initial wound area. The owner reported by telephone the complete healing and hair growth 10 days after discharge.Discussion: Despite the atypical location of the tumoral lesion described at the present report, the history and clinical manifestations, especially the intense pruritus, showed similarity with other characteristic reports of equine cutaneous pythiosis. The diagnosis was confirmed by the histopathological examination showing hyphae structures, as described to be evidences of the presence of Pythium insidiosum in the tissue. The surgical procedure was the first step to provide remission of clinical signs, and one day after surgery the pruritus desapeared. After excision of the granulomatous tissue and cauterization, daily topical administration of amphotericin B associated with DMSO was effective in destroying the infectious agent, as observed by the excellent epithelization. A pink granulation tissue grew up providing an ideal surface for epithelial migration and the healing process progressed quickly. Centripetal epithelialization reduced the wound area until 3% of the initial area in 64 days of treatment, when the remaining wound was found almost completely healed and covered with hair. At the present report, the horse presenting pythiosis was only topically treated. The recommended therapy using amphotericin B and DMSO solution was effective, economically viable and low risk, considering that the systemic antifungal therapy usually suggested is expensive and extremely nephrotoxic. The atypical location of the lesion on the left flank shows that any anatomical region can be affected by the fungus, since the conditions for its development were present.

Custo-efetividade da terapia compressiva no processo de cicatrização de úlceras venosas

Analytical study of therapeutic nonrandomized intervention type, intra-group controlled, with the aim of analyzing the cost-effectiveness of compression therapy with manipulated Unna boot in relation to conventional therapy in the healing of venous ulcers (VU) of patients treated in ambulatory clinic. The study population was composed by patients with VU treated by angiologists in Surgical Clinic Ambulatory of the Onofre Lopes University Hospital (HUOL) with a sample of 18 patients. It obtained the assent of the HUOL Ethics in Research Committee (Protocol 276/09). Data collection was performed over a period of four months by the own master's student and 34 nursing students, through the application of the research instrument in the admission of patients to the study and in the ten subsequent evaluations, performed at the time of changing Unna boot, weekly, for a maximum period of 10 weeks. The data were analyzed with SPSS 15.0 software, using descriptive and inferential statistics, and presented as tables, charts and graphs. Among those surveyed, prevailed: females, mean age 57.6 years, low education and income levels, most retired, unemployed or off work, with the standing position more than six hours per day and up to eight hours daily of domestic or occupational activities. In health status profile of respondents there were predominantly sleep, rest and inadequate elevation of the lower limbs, no smoking and/or alcohol use, presence of hypertension and no use of drugs. Most presented the first VU for over 10 years, recurrences, present VU for more than five years, involvement of left leg, in malleolar and / or distal leg region, mild edema, hyperpigmentation, lipodermatosclerosis, telangiectasies, reticular and varicose veins, mild pain, serous exudate in moderate quantity, small lesions (up to 50cm2), with predominance of granulation tissue and / or epithelialization and demarcated, elevated and irregular borders, with crusts and macerated. Most patients reported that in the 10 weeks prior to admission, made bandages at home and / or Basic Health Unit and / or ambulatory, with nursing aides or technicians, daily, and on weekends or holidays, performed by patients themselves, using healing ointment on the lesion, being observed granulation / epithelialization and increase in VU prevalent in the 10 weeks of traditional treatment. After follow up with manipulated Unna boot, was observed a decrease of lesions in all study patients, with complete healing in 27.8% of those between 1 and 5 weeks of treatment, with satisfactory evolution of the lesions, pain and ankle and calf circumferences, and unsatisfactory development of the borders of ulcers, edema, sleep, rest and elevation of the lower limbs, especially in more chronic patients. Furthermore, patients who achieved total healing and exhibited the greatest percentage reduction of lesions had a higher number of wound healing factors (ρ = 0.01 and ρ = 0.027, respectively). The manipulated Unna boot showed better results in those patients with shorter duration of injury, leading them to a satisfactory outcome within a short period of treatment. After the cost-effectiveness analysis, we conclude that the manipulated Unna boot is more effective than conventional therapy in the healing process of VU and is more cost-effective in patients with shorter lesions (ρ = 0.001), shorter treatment (ρ = 0.000) and greater number of wound healing factors (ρ = 0.005).

Qualidade da assistência e o conhecimento sobre o direito à saúde das pessoas com úlcera venosa crônica

The study aimed to identify the quality of care and knowledge of health rights of people with chronic venous ulcers (VU) in Brasilian National Health Care System (SUS). It is a cross-sectional study, with quantitative approach, performed at the University Hospital Onofre Lopes (HUOL). The study was approved by the Ethics Committee of HUOL (CAAE nº 0148.0.051.000-10). The sample by accessibility was composed for 30 people with VU treated at the outpatient surgical clinic of HUOL. For data collection we used a structured questionnaire composed of two parts: sociodemographic characteristics and of health, of care and the clinical course of VU; and knowledge of people with VU about the rights of health. The results were processed using SPSS 15.0 and analyzed by descriptive statistics. Given the characterizations sociodemographic and health presented, we identified a clientele of users with VU predominantly female (76,7%), aged from 60 years (66,7%), married/ stable union (60,0%), low education level (83,3%), family income lower than a minimum wage (73,3%), unemployeds and with chronic diseases (53,3%), sleep greater than or equal to 6 hours (76,7%) and were not alcoholics or smokers (93,3%). In relation to clinical conditions, were shown the presence of one or more relapses of VU (73,3%), predominance of granulation tissue/epithelialization in the bed of VU (60,0%), exudate serosanguineous (43,3%), in quantity medium/large (60,0%), with no predominance of presence or absence of odor (50,0%), all patients with tissue loss in grade III / IV, no signs of infection (73,3%) and presence of intense pain (50,0%). In the last 30 days the main venue of achievement of dressing was the HUOL (100,0%), the main compression therapy used was the Unna boot (60,0%) and on inability to perform the dressing on the unit were the own patients who made the exchange at home (40,0%). The majority of respondents listed out more positive factors associated with quality of care (56,7%) were satisfied with the care of SUS (76,7%), claimed to have knowledge about their rights (70,0%), but at the same time did not know the meaning of the acronym SUS (90,0%) and classified their level of information as inappropriate (70,0%). We realize that people with VU identified as good the quality of care and demonstrated inadequate knowledge about their rights to health in the SUS, but showed interest in acquiring more information. The basic rights to entry in the SUS are constitutionally guaranteed and need to be disseminated in order to make them known to the population, so it can be implemented and ensured a greater resolution assistance in treating this type of injury

Treatment of venous ulcers with fibrin sealant derived from snake venom

Venous ulcers of the lower limbs complicated by infection or chronicity represent a serious public health problem. The elevated number of those afflicted burdens the health services, interferes in quality of life and causes absenteeism. Although there are 2,500 items on the market, ranging from the simplest dressing up to the most complex types of dressing, treatment remains a challenge. Among the substances used, fibrin sealant is the one that promotes diminution of bacterial colonization and of edema, controls hemorrhaging, alters the pain threshold by protecting the nerve endings, hydrates the wound bed and forms granulation tissue that favors healing. Its disadvantages include higher cost and utilization of human fibrinogen that can transmit infectious diseases. The Center for the Study of Venoms and Venomous Animals (CEVAP) at São Paulo State University (UNESP) developed a new sealant made up of fibrinogen extracted from large animals and from an enzyme obtained from snake venom. The present study, developed in the Health Education Clinic (CEPS) of Sacred Heart University (USC) aimed to evaluate the effect of the new sealant on the healing process of venous ulcers in 24 adult patients, seven of whom were male and 17 female. Two study groups were formed as follows: Group 1 (G1) - control group of 11 patients treated with essential fatty acid (EFA) and Unna's boot, and Group 2 (G2) - 13 patients treated with essential fatty acid (EFA), fibrin sealant and Unna's boot. The follow-up lasted eight weeks and the sealant was applied at only the first and fourth weeks. The results showed that Group 2 presented worse lesion conditions as to healing, but, when comparing the two groups, it was noteworthy that the the sealant was effective in healing venous ulcers. There is evidence that the new sealant is recommended for leg ulcers with the following advantages: ease of application, preparation of the wound bed, diminution of pain and a higher number of discharges in the eighth week. More important, other positive characteristics are non-transmission of infectious diseases, absence of adverse reactions, and economic advantage of being produced by Brazilian technology. Finally, it is suggested that the weekly application of sealant, for at least eight weeks, could improve the healing process and consequently life quality.

Repair of the anophthalmic cavity of rats with synthetic hydroxyapatite

We placed spheres of synthetic hydroxyapatite (calcium chloride combined with sodium phosphate) in the eviscerated or enucleated orbital cavity of rats in order to evaluate the biocompatibility of this material with the orbital cavity. The study was conducted on 50 albino rats, 25 of which were submitted to enucleation and 25 to evisceration of one eye. The animals were sacrificed 7, 15, 21, 30 and 60 days after surgery and the orbital content was submitted to histopathological examination. A reaction of the young granulation tissue type was observed first. The hydroxyapatite was gradually surrounded by a granulomatous macrophage inflammatory response and covered with dense connective tissue that formed a sort of mesh septating and supporting progressively smaller blocks of the substance. The same type of reaction was observed in the enucleated and eviscerated cavities. We conclude that synthetic hydroxyapatite is an inert nonallergenic material which is appropriate for volume replacement in the anophthalmic cavity

Influence of ovariectomy on healing of autogenous bone block grafts in the mandible: A histomorphometric study in an aged rat model

Purpose: The aim of this study was to evaluate quantitatively and qualitatively the influence of estrogen deficiency on autogenous bone block grafts in aged variectomized rats. Materials and Methods: Fifty 12-month-old female Wistar rats were used in the study. They were divided into 2 groups, an ovariectomized group and a sham-operated group. After 30 days the animals received autogenous block bone grafts on the angle of the mandible, harvested from the calvaria. The animals were euthanized at 7, 14, or 28 days postoperatively. Results: Histologic analysis showed that at 7 days postsurgery, the interface between graft and recipient site in the sham-operated group appeared filled by a granulation tissue with angiogenic activity, whereas the ovariectomized group still exhibited a blood clot and a granulation tissue in organization. on the 14th postoperative day, the interface in the shamoperated group was partially filled by newly formed bone establishing a union between the graft and the recipient site. The interface in the ovariectomized group was typically filled by granulation tissue with discrete osteogenic activity in most specimens. on the 28th postoperative day, the graft in the sham-operated group appeared histologically integrated to the mandible. However, the interface in the ovariectomized group appeared partially filled by newly formed bone, with areas of interposed connective tissue. The statistical analysis revealed that bone neoformation was significantly greater in the sham-operated group (57.41% at 14 days and 68.35 at 28 days) in comparison with the ovariectomized group (40.82% at 14 days and 53.09 at 28 days) at the 5% level. Conclusion: The estrogen depletion caused by the ovariectomy hindered the healing process of autogenous block bone grafts placed in the mandibles of aged rats.

Processo de reparo em feridas de extração dentária em camundongos tratados com o complexo Symphytum officinale e Calendula officinallis

Medicamentos homeopáticos como o Symphytum officinalle e a Calendula officinallis são dotados de propriedades anti-sépticas, antiinflamatória, cicatrizantes e também agem como promotores da consolidação de fraturas ósseas. Neste trabalho, uniram-se esses dois medicamentos similares em um complexo para verificar o seu efeito no reparo em feridas de extração dentária em camundongos. O complexo Symphytum officinalle e Calendula officinallis nas potências de 6CH e 3CH, respectivamente, foi ministrado por via oral ao grupo tratado durante 5 dias antes e após a extração do incisivo superior direito. No grupo controle, administraram-se 5ml de álcool etílico a 70% diluídos em 30 ml de soro fisiológico. Após a proservação, os animais foram sacrificados, a maxila direita separada da esquerda, fixada e processada para inclusão em parafina. Após a microtomia, os cortes obtidos foram corados pela H/E. A análise histológica mostrou que, tanto no grupo controle como no tratado, o alvéolo dentário estava preenchido por tecido de granulação e tecido ósseo neoformado, com graus variáveis de maturação, rico em osteócitos. No entanto, nos animais tratados, o processo de reparo em feridas após extração dentária do incisivo superior direito mostrou um avanço progressivo de neoformação óssea mais acentuado quando comparado ao grupo controle, em tempos equivalentes. Estes resultados enfatizam as propriedades biológicas do complexo Symphytum officinalle e Calendula officinallis e sua possível utilização como recurso terapêutico na Odontologia.

Polyurethane and PTFE membranes for guided bone regeneration: Histopathological and ultrastructural evaluation

Objective: The purpose of this study was to research a membrane material for use in guided bone regeneration. Study design: In this study, 25 male Wistar rats were used to analyze the biocompatibility and degradation process of biomembranes. The morphological changes in subcutaneous implantations were assessed after 7, 14, 21, 28 and 70 days. The materials were made of polyurethane polymer (AUG) obtained from vegetal oil (Ricinus communis) and polytetrafluoroethylene membrane (PTFE). The surface characteristics of the physical barriers in scanning electronic microscopic (SEM) were also evaluated. Results: In both groups, the initial histological analysis showed moderate inflammatory infiltrate, which was predominantly polymorphonuclear. There was also a presence of edema, which was gradually replaced by granulation tissue, culminating in a fibrous capsule. In the AUG group, some multinucleated giant cells were present in the contact interface, with the space previously occupied by the material. However, membrane degradation was not observed during the period studied. According to the present SEM findings, porosity was not detected in the AUG or PTFE membranes. Conclusion: The researched material is biocompatible and the degradation process is extremely slow or may not even occur at all.