Nandrolone decanoate in induced fracture nonunion with vascular deficit in rat model: morphological aspects.

BACKGROUND: The nonunion fracture is a relatively frequent complication in both human and veterinary medicine. Specifically, atrophic fracture nonunions are difficult to treat, with revision surgery usually providing the best prognosis. Anabolic steroids, such as nandrolone decanoate (ND), have been reported to have beneficial clinical effects on bone mass gain during osteoporosis; however, their utility in promoting regeneration in atrophic nonunions has not been documented. Our objective was to examine morphological changes induced by the ND in experimental fracture nonunion with vascular deficit in the rat model. METHODS: Fourteen adult Wistar rats had an atrophic fracture nonunion induced in the diaphysis of their left femur. Rats were allocated into two groups: control group and nandrolone decanoate group. Rats in the latter group were given nandrolone decanoate (1.5 mg/kg IM, once a week, during 4 weeks after confirmation of fracture nonunion radiographically). Radiographic and anatomopathological examination, micro-tomography and histological analysis were assessed to characterize the morphological changes promoted by the nandrolone decanoate use. RESULTS: Based on radiology, anatomopathological evaluation, computed micro-tomography and conventional microscopy, nandrolone decanoate promoted bone regeneration at the fracture nonunion site by increasing the cellularity at the fracture site. Percentage of collagen was not significantly different between groups, consistent with high-quality regenerated bone. CONCLUSION: The anabolic steroid nandrolone decanoate improved bone mass and regeneration without affecting collagen production and therefore has potential for improving outcomes for atrophic fracture nonunion.

Novel rat model of nonunion fracture with vascular deficit.

Nonunion fractures occur frequently in humans, with profound implications (medical and non-medical). Although there are numerous animal models to study pathogenesis and treatment of nonunion fractures, there is apparently the lack of a definitive model for atrophic nonunion fracture. Therefore, the objective was to develop a low-cost rat model of nonunion fracture with a vascular deficit that enabled standardized quantitative analysis of bone growth and regeneration. The model was developed with two surgeries, performed apart. The first involved osteotomy of the femur diaphysis, removal of periosteum and endosteum, isolation of the fracture site using a latex artefact (Penrose drain tube), and reduction of the fracture using an intramedullary pin, whereas the second surgery was to remove the latex artefact. Based on radiographic imaging, micro-CT and histological analyses done 125 days after the fracture was induced, there was clear evidence of atrophic nonunion fracture, without pin migration or specimen loss. Perceived advantages of this model included low cost, ease of reproducibility, lack of specimen loss, and, finally, the potential to assess bone growth and regeneration under poor vascular conditions.

Influence of omega-3 fatty acids from the flaxseed (Linum usitatissimum) on the brain development of newborn rats.

OBJECTIVES: The importance of essential fatty acids, in particular the omega-3 family, in the central nervous system development of newborns is well documented. The flaxseed (Linum usitatissimum) is considered one of the best vegetable sources of omega-3 fatty acids. The influence of omega-3 fatty acids from flaxseed on the brain development of newborn rats was evaluated. MATERIAL AND METHODS: Pups of the F1 generation were obtained from 18 female Wistar rats divided in 3 groups (n=6), FG: fed with diet based on Flaxseed added with casein, CG: Casein, and MCG: Modified Casein supplemented with fibers and soybean oil. Newborn pups were weighted and submitted to euthanasia; brains were collected for evaluation of weight and lipid profile through gaseous chromatography. RESULTS: Significant increase in brain weight (39%) and relative brain weight (37%) was verified in pups from mothers fed with flaxseed diet. The omega-3 (n-3) fatty acids from the flaxseed were found in abundance in the diet made with this oleaginous and also significant increase in docosahexaenoic acid (DHA) (38%), as well as in total of omega-3 (n-3) fatty acids (62%). CONCLUSION: Maternal diet of flaxseed during pregnancy influences the incorporation of omega-3 fatty acid in the composition of brain tissue, assuring a good development of this organ in newborn rats.

Flaxseed and its contribution to body growth and brain of Wistar rats during childhood and adolescence.

OBJECTIVES: To evaluate the effect of flaxseed upon body growth and brain of rats. METHODS: Experimental phase lasted 52 days, using 42 Wistar rats which were divided into four groups: Control (CG, n = 12), 10% casein diet; Flaxseed (GL, n = 12), 10% flaxseed diet plus casein; Modified Control (GCM, n = 12), 10% casein diet with changes in lipid and fiber comparable to GL; Non-protein (GA, n = 6), diet without protein. Considering food intake, protein intake and weight variation, the Protein Efficiency Ratio (PER) was calculated. Net Protein Retention (NPR) and the Food Efficiency Ratio (CEA) were also determined relative to brain weight at 30 days of life (M30) and at 52 days (M52). Analysis of Variance (ANOVA), Test of Sheffe and post-test of Bonferroni were used, p < 0.05. RESULTS: GL had lower food intake, protein and weight variation than GC, but had higher values than GCM. Concerning PER, GL was lower than GC and similar to the GCM, as well as CEA. As for NPR, GL had lower values than the CG and GCM. At M30, GL was superior to GC in relation to brain weight. Likewise, the same was observed at M52. CONCLUSION: Flaxseed promoted adequate growth and better brain development in animals, which might be explained by increased incorporation of omega-3 into these tissues.

Effect of long-time administration of tibolone on vaginal cytology of castrated rats.

PURPOSE: To evaluate the estrogenic effect of tibolone administered at high-dose and long-term through cytological examination of vaginal epithelium of castrated rats. METHODS: 15 adult Wistar rats were submitted to bilateral oophorectomy 30 days before starting the experiment. The rats were then randomly divided in two groups. Experimental rats (n = 9) orally received 1 mg tibolone/day; control rats (n = 6) just received carboxymethylcellulose. Vaginal smears were collected from all rats on days 0, 1-6, 30, 60, 90 and 120 of the experiment. RESULTS: On day 0, smears from all rats were atrophic, classified as anestrus, and remained this type in the control group until day 120. In the tibolone group, on day 3 all the rats had vaginal cytology similar to estrus and maintained the same aspect till day 90. CONCLUSION: Tibolone has estrogenic action in the vaginal epithelium which is already evident after the first dose and remains without major changes over time.

Incipient spontaneous granulosa cell tumour in the gerbil, Meriones unguiculatus.

In 167 cases of granulosa cell tumour (GCT) in the gerbil, Meriones unguiculatus, 42.5% (71 cases) were in the ovaries, with no evidence of macroscopic lesion. In this paper, we describe the common findings in the incipient--microscopic--type of this spontaneous ovarian tumour occurring in gerbils younger than two years of age.

Systemic mast cell disease in the Mongolian gerbil, Meriones unguiculatus: case report.

A case of spontaneous occurrence of systemic mast cell disease in a non-treated laboratory-reared gerbil is reported. This case corresponds to the form of systemic mastocytosis with bone marrow and visceral involvement associated with skin disease and displays clinically aggressive behaviour. The histopathological, histochemical and ultrastructural features are described.

Growth and differentiation of adult Mongolian gerbil epidermal cells in culture.

A simple protocol for the growth and differentiation of adult Mongolian gerbil epidermal cells is reported. Insulin (8 micrograms/ml) and reduced levels of serum supplementation (2%) were sufficient for the maintenance of these cells in culture. Primary cultures were maintained as a proliferative monolayer in a medium with low calcium concentration (< 0.3 mM). Terminal differentiation of cultures was induced by raising the calcium concentration (1.6 mM) in the medium. These results support the concept derived from mouse epidermal cell culture that calcium is an important regulator of mammalian epidermal cell growth and differentiation. The present protocol also represents a useful tool for studies of mechanisms involved in epidermal cell growth and differentiation in a laboratory animal.

Adult gerbil epidermal cells resistant to terminal differentiation associated with initiation of carcinogenesis.

In order to identify the cellular basis of the gerbil skin unresponsiveness to two-stage carcinogenesis, it was studied the effect of an initiating dose of carcinogen on the biological behaviour of gerbil skin. Treatment of adult gerbil epidermal cells either in vivo or in vitro with 3-methylcholanthrene yielded cells which were resistant to terminal differentiation induced by calcium. These results support the concept derived from the mouse model system of skin carcinogenesis in which initiation is associated with an altered program of epidermal differentiation. The results also suggest that relative resistance of gerbil skin to two-stage carcinogenesis is related to promotion stage.

Craniopharyngioma in the Mongolian gerbil (Meriones unguiculatus): a case report.

A case of spontaneously occurring infiltrative craniopharyngioma in a laboratory-reared gerbil is reported. The histopathological and ultrastructural features are described.

Celulas neuroendocrinas (APUD) en pulmon humano adulto. / Neuroendocrine cells (APUD) in adult human lung

Veinte biopsias pulmonares fueron estudiadas, con la finalidad de determinar la presencia de celulas neuroendocrinas. Con las tecnicas de argirofilia, en 35% de los casos, y con la reaccion argentafin y de basofilia inducida, en 15% de los casos, fueron identificadas celulas distribuidas por el epitelio de bronquios y bronquiolos. El mecanismo de cada reaccion es discutido. La correlacion de los resultados con la citoquimica de las celulas neuroendocrinas descrita en la literatura, permite considerar los elementos identificados en este trabajo, como integrantes pulmonares perifericos del sistema neuroendocrino difuso