Marcelo Barbosa Bezerra

Biópsia hepática com agulha tru-cut guiada por videolaparoscopia em caprinos

The videolaparoscopic guided hepatic biopsy with tru-cut needle is described in 12 healthy, no defined breed, castrated male goats. Animals were distributed in two groups: G1 (n=5) 12-month-old animals; and G2 (n=7) six-month-old animals. The procedure was performed with the animal in left lateral recumbency and under total intravenous anesthesia. Pneumoperitoneum and laparoscopy were performed in the right flank, approximately 10cm ventral to the transverse processes of the lumbar vertebrae. The tru-cut needle was inserted into the right eleventh intercostal space, around 12cm ventral to the spinal column, for punching and removal of a fragment from the right hepatic lobe. The average time spent in the surgical procedure was 23 minutes and five seconds. The hemorrhage caused by the liver biopsy ceased in two minutes (75%) and in three minutes in the other animals (25%). In the clinical evaluations performed during the pre-fasting period and 24, 48, and 72 hours after the biopsy procedure, neither group presented alterations (P>0.05) evaluated by rectal temperature; and cardiac, respiratory, and rumen frequencies. The videolaparoscopic guided hepatic biopsy with tru-cut needle was considered efficacious to be used in goats, providing hepatic tissue fragments suitable for histological examination.

Equine chorionic gonadotrophin improved vascularization of feline ovarian tissue xenografted into immunosuppressed mice

The objective of this study was to evaluate effects of eCG on vascularization and development of feline ovarian tissue xenografted to immunosuppressed mice. Feline ovarian fragments (∼1 mm3) were transplanted under the renal capsule of 20 adult, ovariectomized, C57BL/6 SCID female mice. At 45 d after transplantation, 10 mice (controls) were euthanized and the remainder given 10 IU of eCG (and sacrificed 48 h later). Transplants were recovered immediately after death, fixed, sectioned, and stained with periodic acid-Schiff (PAS). Fragment volume (Cavallieri principle) and vascularization were assessed. Mean xenotransplant volume for control and treatment groups was 0.17 ± 0.03 and 0.37 ± 0.13 mm3, respectively (P = 0.0952); vascular volume density, 30.3 ± 11.3 and 49.1 ± 8.9% (P = 0.0281); surface density, 4.1 ± 2.4 and 6.2 ± 1.7 μm-1 (P = 0.2222); and vessel total surface, 0.63 ± 0.24 μm2 and 2.28 ± 1.05 μm2 (P = 0.0079). In conclusion, eCG significantly increased vascular volume density of xenotransplanted ovarian tissue and improved its development.

Hematological and biochemical profile of BALB/c nude and C57BL/6 SCID female mice after ovarian xenograft

Hematological and biochemical profile studies help to evaluate functional changes of animals used in experiments. The aim of this study was to determine the hematological and biochemical profile of immunosuppressed BALB/c nude and C57BL/6 SCID mice after bovine ovarian xenotransplantation. Therefore, a total of 74 female mice were divided into four groups: non-xenotransplanted animals, xenotransplanted animals, xenotransplanted animals treated with eCG and xenotransplanted animals treated with FSH + LH. After anesthesia, blood samples were collected and hematologic and biochemical values were evaluated. The results showed no significant differences (p ≤ 0.05) for hematological parameters between the control group and the treatment groups of both strains. However, considering the biochemical profile, it was observed an increase of AST concentrations (p ≤ 0.05) in both strains and a decrease of ALT concentrations (p ≤ 0.05) only in C57BL/6 SCID strain of the groups subjected to hormonal treatment compared with those non subjected. Additionally, the values of the renal enzymes, urea and creatinine, did not differ (p ≤ 0.05) between the groups. Our findings suggest that the xenotransplantation procedure as well as the hormonal dosages had no significant effect on the well-being of the animals considering the evaluated hematological and biochemical profile.

Development of fresh and vitrified agouti ovarian tissue after xenografting to ovariectomised severe combined immunodeficiency (SCID) mice

The aim of the present study was to evaluate the development of fresh and vitrified agouti ovarian tissue after xenografting to C57Bl/6 severe combined immunodeficiency (SCID) female mice. Ovaries were obtained from five female agoutis and divided into 16 fragments. Five fragments were transplanted immediately to ovariectomised SCID mice and the others were vitrified, stored for 2 weeks and transplanted only after rewarming. Tissue fragments were transplanted under the kidney capsule in recipients. The return of ovarian activity in recipients was monitored by the observation of external signs of oestrus and vaginal cytology over a period of 40 days after transplantation, after which the grafts were removed and evaluated for morphology, cell proliferation and the occurrence of DNA fragmentation. Ovarian activity returned in four of five mice that received fresh ovarian tissue from agoutis and in one of six mice that had received vitrified tissue a mean (±s.e.m.) 20.6±8.6 days after xenotransplantation. After graft removal, a predominance of primordial and primary follicles was observed in all grafts. Vitrification reduced cell proliferation and increased the occurrence of DNA fragmentation in grafted agouti ovarian tissue. In conclusion, the present study demonstrates that xenografted agouti ovarian tissue, fresh or vitrified, is able to promote the return of ovarian activity in ovariectomised SCID C57B1/6 mice. However, improvements to vitrification protocols for agouti ovarian tissue are necessary.

Xenotransplante de tecidos ovários em animais: limitações, técnicas e inovações. Uma revisão

Xenotransplante consiste em transplantar orgaos, tecidos e/ou celulas de animais, geneticamente modificados ou nao, entre especies diferentes. O xenotransplante ovariano e utilizado como metodo de coleta e maturacao dos foliculos e seus oocitos, e para tanto e necessario ainda aprimoramento de algumas tecnicas. Este artigo de revisao tem como objetivo, abordar aspectos fisiologicos foliculares e registrar o aperfeicoamento da tecnica e de que forma os pesquisadores vem conduzindo seus estudos nos ultimos anos em xenotransplante ovariano animal.