Evaluation of vascular endothelial growth factor gene and protein expression in canine metastatic mammary carcinomas

Effects of Systemic Propranolol Application on the New Bone Formation in Periimplant Guided Bone Regeneration

Objectives

The aim of this experimental animal study was to evaluate the effects of systemic propranolol on new bone formation in peri-implant bone defects.

Material and Methods

Implant slots were created 4mm long and 2.5 mm wide. After the titanium implants were placed in the sockets, 2 mm defects were created in the neck of the implants. Bone grafts were placed in these defects. Then the rats were randomly divided into three equal groups: control (n = 8), propranolol dose-1 (PRP-1) (n = 8), and propranolol dose-2 (PRP-2) (n = 8) groups. In the control group, the rats received no further treatment during the eight-week experimental period after the surgery. The rats in the PRP-1 and PRP-2 groups were given 5 mg/kg and 10 mg/kg propranolol, respectively, every three days for the eight-week experimental period after the surgery. At the end of the experimental period, the rats were euthanized. Blood serum was collected for biochemical analysis, and the implants and surrounding bone tissues were used for the histological analysis.

Results

There were no significant differences in the histological analysis results and the biochemical parameters (alkaline phosphatase, calcium, creatinine and phosphorus) of the groups (P > 0.05). Also, in the test groups, there was numerically but not statistically more new bone formation detected compared with the controls.

Conclusions

Within the limitations of this study, propranolol did not affect the new bone formation in peri-implant defects.

VEGF-B, VEGF-A, FLT-1, KDR, ERBB2, EGFR, GRB2, RAC1, CDH1 and HYAL-1 Genes Expression Analysis in Canine Mammary Gland Tumors and the Association with Tumor ClinicoPathological Parameters and Dog Breed Assessment

Canine mammary gland tumors (CMTs) are one of the most prevalent cancers in dogs and a good model for human breast cancer (BC), however gene expression analysis of CMTs is scarce. Although divergence of genes expression has been found in BC of different human races, no such research of different dog's breeds has been done. The purpose of this study was to investigate expression of the VEGF-B, VEGF-A, FLT-1, KDR, ERBB2, EGFR, GRB2, RAC1, CDH1 and HYAL-1 genes of canine mammary carcinomas, compare the expression levels with clinicopathological parameters and analyze expression disparities between different breeds. Carcinomas and adjacent tissues were collected from female dogs to perform routine histopathology, immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR). We found that VEGF-B and EGFR genes were overexpressed in the mammary gland carcinomas compared to adjacent tissue. VEGF-B gene expression had associations with different parameters (tumor size, grade, and absence of metastasis). Furthermore, differences in VEGF-B, FLT1, ERBB2, GRB2, RAC1, CDH1 and HYAL-1 genes expression have been found in different breed dogs (German Shepherd, Yorkshire Terrier) and mixed-breed dogs indicating that a dog's breed could determine a molecular difference, outcome of cancer and should be accounted as a confounding factor in the future gene expression research.

A comparison of different bone graft materials in peri-implant guided bone regeneration

The aim of this study was to compare the effects of hydroxyapatite (HA), deproteinized bovine bone (DPB), human-derived allogenic bone (HALG), and calcium sulfate (CAP) graft biomaterials used with titanium barriers for bone augmentation to treat peri-implant defects in rat calvarium treated by guided bone regeneration (GBR). Thirty-two female Sprague-Dawley rats were divided into four groups: DPB, HALG, HA, and CAP. One titanium barrier was fixed to each rat's calvarium after the titanium implants had been fixed. In total, 32 titanium implants and barriers were used. Ninety days after the surgical procedure, all the barriers were removed. After decalcification of bone tissue, the titanium implants were removed gently, and new bone regeneration in the peri-implant area was analyzed histologically. Immunohistochemical staining of vascular endothelial growth factor (VEGF) was also performed. There were no statistically significant between-group differences in new bone regeneration or VEGF expression after 3 months. According to the results of the histological and immunohistochemical analyses, none of the grafts used in this study showed superiority with respect to new bone formation.