Veterinary Research Forum

Abstract Bone tissue engineering offers a potential alternative to conventional grafting by combining biocompatible scaffolds with biological stimulants. Polycaprolactone (PCL) is a biodegradable polyester with good mechanical strength and biocompatibility. Hydroxyapatite (HA) is a calcium phosphate mineral that is a major component of bone and has excellent bioactivity and biocompatibility. This research investigated the histopathological effects of PCL-HA nanocomposite scaffolds along with their combination with platelet-rich fibrin (PRF), on the regeneration of bone in rabbit calvarial bone defects. Four circular full-thickness bone defects of 5.00 mm in diameter were created on the calvarial bone of 15 male New Zealand white rabbits. Three defects were filled with PRF, PCL-HA, and PCL-HA/PRF, and one defect was served as a control with no filler. Histopathological evaluations were conducted at 4-, 8-, and 12-weeks post-implantation. Data were evaluated using the Kruskal-Wallis and Mann-Whitney U tests. Significant differences were observed between the treatment and control groups regarding bone regeneration throughout all 12^th weeks studied. In the 4^th weeks, no significant differences in bone regeneration were noted among the treatment groups. In the 8^th weeks, most new bone formation was observed in the PCL-HA/PRF group. Both the PCL-HA and PCL-HA/PRF groups significantly improved bone regeneration compared to the control and PRF groups, with the PCL-HA/PRF group demonstrating the greatest bone formation, and vascularization and the lowest inflammation by the 12^th week. Thus, PCL-HA/PRF could be considered as a suitable alternative to bone grafts and could be increasingly utilized in orthopedic surgery and bone tissue engineering.

Abstract In addition to the fifty years since the test-and-slaughter program began in Iran and despite a significant reduction in the disease prevalence, positive tuberculosis cases are still being isolated from livestock farms across the country. Tests with 100% sensitivity and specificity are essential features for bovine tuberculosis diagnosis. The relationship between real-time PCR and immunohistochemistry (IHC) as two essential laboratory methods in the diagnosis of bacterial infections were aimed to evaluate single intradermal comparative tuberculin test (SICTT) results. One hundred thirty-eight cows in two groups were examined: Reactors (108 cows) and clean (as a control group; 30 cows). In the reactor group, 58(54.00%) cows were Mycobacterium bovis positive, 46(43.00%) were Mycobacterium avium subsp. paratuberculosis (MAP) positive, and 11(10.00%) were Mycobacterium tuberculosis positive. 32(55.00%) cows were co-infected with M. bovis and MAP and 5(4.55%) cows were co-infected with Mycobacterium tuberculosis and MAP in this group. Of 50 M. bovis negative cows of reactor group were 14(28.00%) MAP positive and 36(72.00%) negative, as well. Concurrent infection with all was observed in one reactor case. Comparing IHC and real-time PCR for the detection of bovine tuberculosis and Johne’s disease showed very good agreement (Kappa values 0.81 - 1.00). The results also provided further confirmation on IHC and real-time PCR as a sensitive and reliable diagnostic screening approach for detection of bovine tuberculosis. The use of one laboratory method to detect bovine tuberculosis is not sufficient alone.

Abstract A 14-year-old female Shih Tzu was presented with conjunctivitis, keratitis, an enlarged mass located on the left lower eyelid and a large subcutaneous cyst in the temporal region. The hematological and biochemical analyses revealed no significant issues. The mass and the cyst were taken from the base with 1.50 cm of the underlying tissue. On histological examination, the mass was made up of adenoid arrangements of sebocytes and basaloid reserve cells with low to moderate mitotic activity of basaloid cells. In addition, a large number of meibomian ducts with marked infiltration of mononuclear inflammatory cells and melanin pigment were observed in the ductal part of the tumor. The cyst was lined by a simple cuboid-like epithelium with no eosinophilic cuticular lining. Immuno-histochemical staining of the mass with CK14 showed positive reaction in the neoplastic basaloid reserve cells and adipocytes; but, not with CK18 and vimentin. Unlike, the luminal cells of the cyst were stained with CK18. The co-existence of mixed meibomian gland and ductal adenoma with an apocrine sweat gland cyst was diagnosed based on the clinical, histological and immunohistochemical findings.