The purpose of the present study was to evaluate the efficacy of propolis extract in maintaining the viability of human periodontal ligament (PDL) cells, and to radiographically analyze tooth replantation and the adjacent periodontium in dogs after storage in this extract. Human PDL cells were incubated with the experimental media propolis, milk, saliva, Hank's balanced salt solution (HBSS), and Dulbecco's modified Eagles medium (DMEM, positive controls), and distilled water (negative control). Cell viability was determined 0, 1, 3, 6, 12, and 24 h later by colorimetric MTT assay. Thirty incisors from dogs were divided into two storage time blocks (1 and 3 h) and were maintained in the experimental media. HBSS served as a positive control, and dry teeth (on gauze) as a negative control. The replanted teeth were radiographed once per month for 6 months. The radiographic images were standardized by the shortening/lengthening factor, and were both qualitatively and quantitatively analyzed. The in vitro results showed that the efficacy of propolis in maintaining functional viability of PDL cells was similar to that of milk. Propolis and milk were significantly better than controls from the 6-h time period. The in vivo results showed that teeth maintained in propolis medium exhibited replacement resorption with significant reduction in tooth length, similar to teeth maintained in saliva and dried teeth. This resorption was less intense with the 3-h storage time than the 1-h storage time. Conditions close to normal were found in teeth maintained in milk, similar to the HBSS control. Therefore, although propolis was effective in maintaining the viability of human PDL cells, resorption of the tooth replantation in dogs occurred under these experimental conditions.

A xilazina produz um bom efeito sedativo-analgésico quando associado à drogas anestésicas. O tiopental sódico é um barbitúrico de curta duração que produz sonolência, sedação e hipnose. O objetivo deste trabalho é verificar a eficiência da associação da xilazina como pré-medicação e do tiopental sódico na manutenção da anestesia, em cães. Foram usados 32 cães sem raça definida, adultos, machos e com peso entre 8 e 10 kg, que foram submetidos à procedimento operatório no esôfago cervical. A dose média de xilazina administrada foi de 3,8 mg/kg e de tiopental sódico foi de 7,7 mg/kg. Não houve necessidade de intubação endotraqueal e não ocorreu óbito relacionado com as medicações anestésicas. Concluindo, o procedimento anestésico descrito é de fácil execução, é seguro e diminui o estresse do animal.

In previous work, it was shown that gangliosides (Gang) have an inhibitory effect on lymphocyte proliferation as well as on delayed-type hypersensitivity response and mixed lymphocyte reaction. Therefore, we decided to examine the effect of gangliosides in acute allorejection after fetal intestinal transplantation. We used two female C57BL/6 mice on pregnancy day 19 as a source of fetal intestine. All animals were anesthetized with ketamine (70 mg/kg) and xylazine (10 mg/kg), intramuscularly. We harvested intestinal segments of 1 cm to transplant into BALB/c and C57BL/6 mice (male, weighing around 20 g) used as recipients. They were divided into groups of six animals each: isogeneic and allogeneic without treatment, or treated with tacrolimus 1 mg/kg/day, or gangliosides 3 and 9 mg/kg/day, during 7 days posttransplantation, intramuscularly. On postoperative day 7, intestinal grafts were collected and fixed in 10% formalin solution. Using an anesthetic overdose as euthanasia, we removed the intestinal grafts. Tissue samples were stained with hematoxylin-eosin for histological analysis regarding grafts development (D) and rejection (R) aspects. Data were analyzed by the Kruskal-Wallis test, considering P < or = 0.05 as significant. In the isogeneic and tacrolimus groups, we observed a very good degree of development (D = 9 +/- 0.5; D = 9 +/- 0.4, respectively), but a severe degree of rejection (R = 15 +/- 1.3) and a low degree of development (D = 1 +/- 0.8) in animals without treatment. The ganglioside groups showed D = 5 +/- 1.6 and R = 13 +/- 3.3, and D = 7 +/- 2.9 and R = 9 +/- 1.9, for the 3-mg and 9-mg groups, respectively. There was a statistically significant difference between the ganglioside groups and allogeneic groups without treatment. Based on the above data, we conclude that avascular fetal intestine transplantation is a good experimental model for studying immunological events, and that gangliosides only partially modulate the allorejection response, allowing intestinal development, mainly at the highest ganglioside dose. Maybe immunomodulation would be better observed by using isolated types of gangliosides or association with other immunosuppressive drugs.