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 this study, a controlled released delivery drug system designed and synthesized by loading curcumin and selenium nanoparticles (SeNaPs) on chitosan hydrogel, and while evaluating the physicochemical properties of the prepared drug delivery system, the tissue changes caused by the local implant of that system in rats with experimental spinal cord injury (SCI) were investigated. For this purpose, 100 adult female rats were randomly divided into five equal groups which are: Control group without any treatment for SCI, chitosan group that received chitosan hydrogel, curcumin group that received curcumin-loaded hydrogel, SeNaP group that received chitosan loaded with SeNaPs and SeNPCur group that received chitosan loaded with SeNaPs and curcumin. On the 3^rd and 7^th days of the study, severe infiltration of leukocytes, especially lymphocytes, as well as axon swelling and hemorrhagic necrosis at the lesion sites were observed in all groups, especially the control group. On the 7^th day, the severity of these injuries decreased in the SeNPCur group and the highest number of astrocytes was observed in this group. In addition, on the 14^th and 21^st days of the study, the lowest severity of nerve tissue damage and the lowest presence of inflammatory cells along with the highest number of astrocytes were seen in the SeNPCur group. The glial fibrillary acidic protein study also confirmed the presence of more and significant astrocytes in the SeNPCur, curcumin and SeNP groups at different times of the study, respectively. The histopathological results showed the neuroprotective effects of chitosan hydrogel loaded with selenium and curcumin.

Abstract This study investigated the effect of captopril (Cap) on spinal cord ischemia-reperfusion injury (SCII) in rats. Twenty-four adults male Wistar rats were randomly divided into four groups of six animals each: spinal cord ischemia-reperfusion (SCI-R) with Cap (SCI-R + Cap), SCI-R, sham-operated with Cap (SHAM + Cap), and SHAM. The 24 hr and 90 min before ischemia induction, Cap was administered intragastrically (100 mg kg^-1) to the SHAM + Cap and SCI-R + Cap groups. Abdominal aortic clamping was performed in the SCI-R and SCI-R + Cap groups for 40 min. Hindlimb motor function was evaluated using the Tarlov Scale at 4, 6, 12, 24, 48, and 60 hr after SCII. The malondialdehyde (MDA), the ferric-reducing ability of plasma (FRAP) and prooxidant-antioxidant balance (PAB) values were also measured. Throughout the study period, the SCI-R group had significantly lower motor function scores compared to the other groups. The MDA and PAB levels were higher and the FRAP value was lower in the SCI-R group compared to in the SHAM group. The SCI-R + Cap had higher motor function scores compared to the SCI-R group at all time points. There were no significant differences in MDA concentration, FRAP and PAB values between the SCI-R + Cap and SCI-R groups. Captopril may act as a protective agent against SCII in rats based on hind limb motor function assessment.

Abstract The purpose of this study was to investigate the effects of three anesthetic agents, with premedication of medetomidine and midazolam, on electrocardiographic variables in dogs. Ten adult mixed breed dogs were used in a crossover design study, where they received ketamine, propofol and isoflurane treatments with a one-week washout period between them. In all three groups, medetomidine was administered first followed by midazolam after 15 min. Then, after 20 min, group 1 received ketamine intravenously (IV), group 2 received propofol (IV), and group 3 received isoflurane (inhalation). In all dogs, electrocardiographs were taken before and after premedication’s, as well as every 15 min during anesthesia. Medetomidine significantly decreased heart rate and P wave amplitude and increased PR interval, R wave amplitude, QT interval, and T wave amplitude. Midazolam increased the amplitude of the R and T waves. Ketamine increased the heart rate and PR interval. Propofol increased the heart rate for up to 15 min, decreased the PR interval for up to 30 min, and the QT interval for up to 45 min. Isoflurane increased the heart rate and decreased the amplitude of R and T waves. The results showed that the drugs used in this study did not have many side effects on electrocardiographic variables and could be used without serious concern. The most important side effects observed were a severe reduction in heart rate and 1^st degree atrioventricular (AV) block and, to a lesser extent, 2^nd degree AV block caused by medetomidine and midazolam which were masked by the anesthetics.

Abstract Spinal cord injury (SCI) presents challenging and unpredictable neurological recovery. During inflammatory conditions, the amount of serum albumin and nutrition consumption decreases. Currently, it is proposed to measure serum albumin and glucose content in human or animal subjects to predict the recovery rate and the efficiency of treatments following SCI. In this study, the effect of extra-cellular vesicles (EVs) from immortalized human adipose tissue-derived mesenchymal stem cells (hTERT-MSCs) equipped with the ectopic expression of the human indoleamine 2,3-dioxygenase-1 (IDO1) gene on serum albumin and glucose levels was investigated. After pre-clearing steps of 72-hr conditioned media, small EVs (sEVs) were isolated based on the ultra-filtration method. They were encapsulated with a chitosan-based hydrogel. Five experimental groups (female rats, N = 30, ~ 230 g) were considered, including SCI, sham, hydrogel, control green fluorescent protein (GFP)-EVs and IDO1-EVs. The 60.00 µL of hydrogel or hydrogels containing 100 µg sEVs from GFP or IDO1-EVs were locally injected immediately after SCI (laminectomy of the T10 vertebra and clip compression). After 8 weeks, non-fasting serum glucose and albumin levels were measured. The results indicated that the level of serum albumin in the animals received IDO1-EVs (3.52 ± 0.04) was increased in comparison with the SCI group (3.00 ± 0.94). Also, these animals indicated higher glucose levels in their serum (250.17 ± 69.61) in comparison with SCI ones (214 ± 45.34). Although these changes were not statistically significant, they could be considered as evidence for the beneficial effects of IDO1-EVs administration in the context of SCI to reduce hypoalbuminemia and improve energy consumption. More detailed experiments are required to confirm these results.

Abstract The development of tooth is a complex process wherein there is a series of interactions between the ectoderm and ectomesenchyme. Hyperdontia (also called supernumerary teeth) is a developmental abnormality being additional to the normal series of teeth with unknown etiology and is rare in ruminants. In this report, a rare case with two abnormal teeth outside the alveolar region, observed in a healthy 3-month-old female lamb was presented. The congenital defect consisted of the presence of 2 teeth positioned bilaterally in the caudal part of the mandible ramus and under the prominent pendulous skin; so, with retraction of prominent pendulous skin, these ectopic teeth were seen outside of the skin. The anomaly was found during a routine physical examination and no other congenital abnormalities were found in the lamb. The etiology of supernumerary teeth is not completely understood. This odontogenic abnormality appears to be an extraordinarily rare condition. Genetic, toxic, infectious or environmental factors related to congenital abnormalities affect the tooth growth. Depending on the supernumerary teeth position, surgery may be required.

Abstract The pomegranate seed oil (PSO), containing 17-α-estradiol, is one of the newly found phytosterols with synergistic health effects on estrogen related physiological conditions. Herein, PSO was assessed for its potential improving effects on bone characteristics in a rat model of menopausal syndrome. Three month old non-pregnant female Wistar rats (n = 30) were either sham-operated (SHAM) or ovariectomized (OVX), each divided into two further groups receiving 0.1 mL PSO or the same volume of paraffin oil as placebo. Before the operation and 67 days after it, multi-detector computed tomography (MDCT) scanning was performed with the identical setup option for the scanner to measure the bone mineral density (BMD) in body of 12^th thoracic vertebra, 1^st to 6^th lumbar vertebra and sacrum. This study revealed that bone density of 1^st, 3^rd, 5^th, 6^th and sacrum body were significantly different between OVX and SHAM groups during the study period. In conclusion, PSO during 67 days study could not completely prevent the osteoporotic effects caused by ovariectomy in vertebral column of rats.