Uso da túnica vaginal canina conservada em glicerina a 98% como curativo biológico no tratamento de feridas cutâneas produzidas em ratos Wistar / Use of canine vaginal tunic preserved in 98% glycerin as biological curative in the treatment of skin produced in wound Wistar rats

Na procura por material alternativo no tratamento de feridas cutâneas, buscou-se com este estudo avaliar o comportamento da túnica vaginal canina conservada em glicerina a 98% como curativo biológico no tratamento de feridas cutâneas provocadas experimentalmente em ratos. Foram utilizados 16 ratos Wistar, nos quais foram induzidas experimentalmente duas lesões cutâneas na região dorsal, sendo uma cranial e a outra caudal. Uma ferida serviu de controle, a qual não recebeu tratamento, a outra recebeu a túnica vaginal recobrindo toda extensão da lesão. A seleção de qual das feridas, cranial ou caudal, iria receber a membrana foi feita de forma aleatória. Os animais foram distribuídos em quatro grupos de igual número para análises clínicas, macroscópicas e histológicas decorridos três, sete, 14 e 21 dias de pós-operatório. Na avaliação clínica e macroscópica pode-se observar que o processo de reparação teve evolução semelhante tanto no grupo controle quanto no grupo membrana. Na análise histopatológica foi constatada grande quantidade de infiltrado inflamatório nos períodos iniciais, no entanto, decorridos 21 dias, a epiderme já se encontrava reparada, e em todos os momentos foi observada maior presença de tecido conjuntivo no grupo membrana, sugerindo maior precocidade na cicatrização. Deste modo, concluiu-se que a túnica vaginal canina pode ser utilizada como nova alternativa no tratamento de feridas cutâneas.

In the search for alternative material in the treatment of cutaneous wounds, this study aimed to evaluate the behavior of canine vaginal tunic conserved in glycerin 98% as a biological dressing in the treatment of cutaneous wounds provoked experimentally in rats. Sixteen animals were used in which two cutaneous lesions were caused in the dorsal region, one cranial and the other caudal. One wound served as a control which did not receive treatment, the other received the vaginal tunic covering all extension of the lesion. The selection of which of the wounds, cranial or caudal, would receive the membrane was made at random. The animals were divided into four groups of equal numbers for clinical, macroscopic, and histological analyzes after three, seven, 14 and 21 postoperative days. In the clinical and macroscopic evaluation, it can be observed that the healing process had similar evolution in both the control group and the membrane group. In the histopathological analysis, a large amount of inflammatory infiltrate was observed in the initial periods; however, after 21 days the epidermis was already healed, and at all times a greater presence of connective tissue was observed in the membrane group, suggesting a greater precocity in healing. Thus, it was concluded that the canine vaginal tunic can be used as a new alternative in the treatment of cutaneous wounds.

Evaluation of fish skin as a biological dressing for metacarpal wounds in donkeys.

BACKGROUND: The use of biological dressings has recently emerged in the management of burns and wounds. The aim of the present study was to evaluate the Nile tilapia skin as a biological dressing for full-thickness cutaneous metacarpal wounds in donkeys. The study was conducted on nine clinically healthy donkeys (n = 9). Here, fish skin dressings were obtained from fresh Nile tilapia (Oreochromis niloticus and sterilized by immersion in silver nanoparticles (AgNPs) solution for 5 min, with no change in collagen content. Bilateral, circular full-thickness excisional skin wounds (2 cm in diameter) were created on the dorsal aspect of the mid-metacarpals of each donkey. Wounds on the right metacarpals (treated wounds, n = 9) were dressed with sterile fish skins, while wounds on the left metacarpals (control wounds, n = 9) were dressed with sterile non-adherent dressing pads without any topical applications. Wound dressings were changed weekly. Wounds were evaluated microbiologically, grossly, and histologically on days 7, 14, and 21 post-wound inductions. RESULTS: Fish skin-dressed wounds showed a significant (P < 0.0001) reduction in microbial counts (Total viable bacterial count, Staphylococcal count, and Coliform count), a significant (P < 0.0001) decrease in the wound size, and a significant reduction (P < 0.0001) in the epithelial gap compared to the untreated wounds. No frequent dressing changes were needed. CONCLUSIONS: Fish skin dressing accelerated the wound healing process and efficiently inhibited the local microbial activity and exuberant granulation tissue formation suggesting its reliable and promising application for metacarpal wounds of donkeys.

Lamellar keratoplasty in rabbits using human and rabbit amniotic membrane grafts: a comparative study.

OBJECTIVE: To compare the behavior of human and rabbit amniotic membrane (AM) grafts in surgically induced corneal thinning in rabbits. ANIMALS STUDIED: Thirty two NZWR were randomly assigned to two groups of 16 animals each according to AM type (Human AM: group HAM and Rabbit AM: group RAM). PROCEDURE: All animals were submitted to right keratectomy at a depth of 0.1 mm using a 5 mm trephine. Animals from HAM group had a button of 5 mm of human AM sutured into the corneal bed with a continuous pattern and 10.0 nylon monofilament suture, while animals from the RAM group had a button of 6 mm diameter of rabbit AM. Four animals in each group were euthanized 2, 7, 15, and 30 days postoperatively. Their corneas were harvested, fixed in 2% glutaraldehyde solution, and stained with haematoxylin-eosin, picrosirius red, and alcian blue for evaluation under light optical microscopy. Microscope images were digitalized and inflammatory cells and stromal blood vessels were counted. RESULTS: There were no clinically significant differences between groups, and complete corneal epithelialization was observed in all animals in 30 days. Light optical microscopy revealed AM incorporation and resorption in both groups. However, the number of inflammatory cells and blood vessels was significantly higher in group HAM than in group RAM (P < 0.05, Mann-Whitney test). Clinical responses to human or rabbit AM were similar; however, human AM induced greater inflammatory reaction and stromal neovascularization in the rabbit cornea than in rabbit AM. CONCLUSION: These differences may reflect a potential reaction to the xenograft. More studies are needed to further characterize these findings.

Human amniotic membrane and vitamin E/selenium for control of postoperative adhesion in dogs.

This study was undertaken to compare between the human amniotic membrane (HAM) and intraperitoneal vitamin E (Vit E) and selenium in prevention of postoperative adhesions in dogs. A total of 18 apparently healthy adult Mongrel dogs were divided into three equal groups and the group (I) was treated with a sterile solution of 0.9% sodium chloride intraperitoneally as a control. Group II was treated with the HAM at jejunal enterotomy while group III was treated with Vit E and selenium administered intraperitonally. Dogs were euthanized 30 days postoperatively for histopathological examination. The results showed that both HAM and Vit E and selenium were effective in reduction of the postoperative adhesion in comparison with the group I. In terms of extent of adhesions, there was no significant difference between the HAM group and the Vit E and selenium group.

Amniotic membrane transplantation for the treatment of feline corneal sequestrum: pilot study.

OBJECTIVES: To describe and evaluate the use of equine amniotic membrane trans-plantation after lamellar keratectomy for the treatment of corneal sequestrum in cats. METHODS: Six cats (seven eyes) of various breed and ages with corneal sequestra were treated surgically with lamellar keratectomy and amniotic membrane transplantation. All the sequestra and a small piece of the amniotic membranes used for each surgery were submitted for histopathologic examination. RESULTS: Five of the seven eyes showed minimal level of scarring in the cornea and good transparency. No recurrences of the sequestra have been noted during the follow-up period (3-9 months). One eye had necrosis of the amniotic membrane 2 weeks after the surgery. The sequestrum of this eye showed a high level of bacterial contamination on histopathology. Three months later the same cat developed a descemetocele in the area where the necrotic amniotic membrane was rejected. A second eye developed a perforation under the amniotic membrane two weeks after the surgery. The sequestrum of this eye was deep and without vascularization. CONCLUSION: Amniotic membrane transplantation after lamellar keratectomy was a valid procedure for surgical treatment of corneal sequestrum in cats. The procedure resulted in excellent cosmesis and functional vision in five of seven eyes; although case selection is important, particularly to exclude the very deep and non-vascularized sequestra.

Effects of 3 biologic dressings on healing of cutaneous wounds on the limbs of horses.

Three biologic dressings [split-thickness allogeneic skin (STS)], allogeneic peritoneum (P), and xenogenic porcine small intestinal submucosa (PSIS)] were studied to determine their effects on bacterial proliferation, inflammatory reaction, vascularization, and overall healing and to compare the effects of these dressings with the effects of a nonbiologic dressing, a nonadherent synthetic pad (NASP). A medial wound (3 cm in diameter) and 2 lateral wounds (2 cm in diameter) were created at the junction of the proximal and middle thirds of each metacarpus and metatarsus in 5 horses. Each medial wound and the proximolateral wound received an STS, P, PSIS, or NASP dressing on day 8 after wounding. The other lateral wound received an NASP dressing. Bacterial proliferation, inflammatory reaction (histologic changes), and drhessing vascularization were evaluated 6 d after application of the dressing. Percentages of contraction and epithelialization, as well as healing time, were determined when the wounds had completely epithelialized. The practical applicability of the different dressings to equine wound management was also assessed. No significant difference was detected in the parameters evaluated among the treated wounds or between the treated and control wounds. The biologic dressings had no effect on infection, inflammatory response, or healing time. Vascularization was not identified in any of the biologic dressings. The PSIS and P dressings required numerous applications over the study period. The STS dressings are more practical than PSIS and P dressings owing to ease of application and stability. Thus, these biologic dressings offer no apparent advantage over a nonbiologic dressing for treatment of small granulating wounds.

The effect of a porcine-derived small intestinal submucosa product on wounds with exposed bone in dogs.

OBJECTIVE: To determine the effect of a porcine-derived small intestinal submucosa product (PSIS) on healing time, epithelialization, angiogenesis, contraction, and inflammation of wounds with exposed bone on the distal aspect of the limbs of dogs. STUDY DESIGN: Prospective, controlled, experimental study. ANIMAL POPULATION: 10 young adult, purpose-bred, male Beagles. METHODS: Small wounds with exposed bone were created on the lateral aspect of metatarsal V and the medial aspect of metatarsal II on both hindlimbs. Three sheets of PSIS were sutured into the wounds of the treated limb, and the other limb served as a control. On day 10, punch biopsies of the medial metatarsal wounds were collected and were evaluated microscopically after routine hematoxylin and eosin and phosphotungstic acid hematoxylin (PTAH) staining. The lateral metatarsal wounds were evaluated by planimetry and laser Doppler perfusion imaging on days 7, 14, and 21. Time until complete wound healing was also recorded. The level of significance was set at P < or =.05 for all statistical analyses. RESULTS: Laser Doppler perfusion measurements were significantly higher in control wounds on day 7, but no differences were noted on days 14 and 21. No significant differences in planimetric values, histopathologic appearance, or time until complete wound healing were noted among treated and control groups. CONCLUSIONS: No objective differences in healing were noted between control wounds and wounds treated with PSIS. CLINICAL RELEVANCE: There appears to be no contraindication to the use of PSIS on clean wounds with exposed bone on the distal limbs of dogs. However, our objective data provides no evidence that this product affects epithelialization, contraction, or time to complete healing in wounds with exposed bone.

Substitutos temporários de pele em feridas: estudo experimental em cäes / Temporary skin substitute products in wounds: experimental trial in dogs

Feridas experimentais foram recobertas com substitutos temporários de pele produzidos com poliuretano, hidrocolóide ou hemicelulose, e avaliadas clinicamente até a cicatrizaçäo. Os resultados mostraram reduçäo mais acentuada da área cruenta nas lesöes recobertas com o curativo de hidrocolóide ao sétimo dia, sem, contudo, ter ocorrido diferença significativa entre os tratamentos

Membrana amniótica preservada em glicerina no reparo de feridas cutâneas de membros locomotores de eqüinos / Equine amniotic membrane preserved in glycerin in reparing the equine limbs cutaneous wounds

Neste estudo experimental, avaliou-se o uso de membrana amniótica eqüina preservada em glicerina 98 porcento, à temperatura ambiente, em feridas com cura por segunda intençäo, nos membros locomotores de eqüinos. Foram provocadas cirurgicamente feridas de 9,6cm2 na face lateral da articulaçäo metacarpo-falangeana, face medial do terço proximal do metacarpo e face lateral do terço médio do metatarso de ambos os membros locomotores de cinco eqüinos adultos, perfazendo total de trinta feridas. Foram constituídos dois grupos experientais com quinze feridas cada, sendo um destes grupos tratado com membrana amniótica, e o outro, grupo controle, tendo recebido apenas gaze umidecida em soluçäo fisiológica. Os curativos foram trocados a cada 48 horas, tendo sido a membrana amniótica e a gaze umidecida substituídas. Em todas as feridas foram mensurados a área, o grau de secreçäo, a formaçäo de tecido de granulaçäo exuberante e o tempo para a epitelizaçäo se completar. Realizou-se também exame bacteriológico e histopatológico em um grupo de feridas, tratadas e controle. Na membrana amniótica, fez-se determinaçäo bioquímica de proteínas e identificaçäo de fator de crescimento de fibroblasto. Em todas as feridas tratadas, observou-se: menor tempo para cicatrizaçäo, menor formaçäo de tecido de granulaçäo exuberante, menor incidência de bactérias patológicas e menor aumento na área total.

An overview of the topical management of wounds.

Wounds in animals are a common and frequent reason for seeking veterinary attention. The way in which wounds are managed affect the rate of healing, the time to return to normal function, the final cosmetic appearance, and hence the satisfaction of customers. The management of wounds depends on the stage of wound healing and can include irrigation, mechanical and chemical debridement, the use of antiseptics and antimicrobials, adherent and nonadherent dressings, and miscellaneous topical applications such as aloe vera, honey and live yeast cell derivative. The advantages, disadvantages and indications for initial wound management, topical applicants and dressings are discussed.

Effects of amnion and live yeast cell derivative on second-intention healing in horses.

Equine amnion and live yeast cell derivative were evaluated as a biological dressing and as a topical wound medicament respectively, in the treatment of granulating wounds of the distal portion of the limbs of horses. Wounds measuring 2.5 x 2.5 cm were created on the dorsomedial aspect of the metacarpal and metatarsal region of all 4 limbs of 9 horses. Each wound was assigned randomly to 1 of 3 treatment groups: group C, treated with a nonadherent bandage as a control; group A, treated with amnion beneath a nonadherent bandage; and group L, treated with live yeast cell derivative beneath a nonadherent bandage. Rates of contraction and epithelialization were not significantly different among groups. Percentage of epithelialization for group A was significantly greater throughout the study than for the other groups. Number of days to complete healing was significantly less in group A and significantly greater in group L than in group C. Incidence and severity of exuberant granulation tissue were significantly less in group A than in the other 2 groups. Group L had more frequent and severe cases of exuberant granulation tissue than the other 2 groups.