Veterinary Research Forum

Abstract Hydronephrosis is an uncommon condition in cats and dogs, characterized by progressive dilation of the renal pelvis and subsequent atrophy of the renal parenchyma. This report described an 8-year-old spayed female domestic longhair cat diagnosed with left-sided hydronephrosis and concurrent polycystic kidney disease after comprehensive clinical, laboratory and imaging evaluation. Because the contralateral kidney appeared functionally preserved, unilateral nephrectomy was selected as the most appropriate treatment option. During surgical manipulation, however, the affected kidney unexpectedly separated completely from its attachments before vascular ligation could be performed, without evidence of hemorrhage. The procedure was completed without complication and no intraoperative or postoperative adverse events were recorded. The patient recovered uneventfully and remained stable throughout the perioperative period. To the authors’ knowledge, this report represented the first documented case in veterinary literature regarding spontaneous renal autoavulsion occurring during nephrectomy. This unusual finding underscored the severe structural fragility that could result from chronic obstructive renal disease and advanced parenchymal destruction. In addition, it suggested that renal autoavulsion might represent a previously unrecognized end-stage manifestation of longstanding hydronephrosis, particularly when associated with concurrent renal pathology such as polycystic kidney disease. This report emphasized the importance of thorough preoperative assessment, careful surgical planning and awareness of potentially extreme anatomic alterations in chronically diseased kidneys.

Abstract The cell scaffolds should structurally be manufactured similar to the target tissue's extracellular matrix. This property should be maintained until cell differentiation. For this purpose, in the current study, electrospun nanofiber (EN) of chitosan (Ch)/polyvinyl alcohol (PVA), as a tissue-friend scaffold, was fabricated by electrospinning in different formulations and borax was utilized as an innovative cross-linking agent to up-regulate the structural and biomechanical properties. The weight loss, water absorbability, structural stability, tensile strength and biocompatibility of borax-included and non-included ENs were compared. The finest morphology, weight loss, water absorbability, structural stability in an aqueous environment, tensile strength and cell viability were found in the borax-included EN containing Ch50.00%v/PVA50.00%v. Moreover, The ENs exhibited appropriate antibacterial properties against Gram-positive and Gram-negative bacteria. In conclusion, borax can be used to improve the mechanical and biocompatibility features of the Ch/PVA-based ENs. Furthermore, it could be suggested that borax-included Ch/PVA ENs can exhibit high appropriate biological properties, candidate them as an appropriate scaffold in the field of tissue engineering. However, in vivo trials are needed to clearly their side effects and advantages.

Abstract Chitosan bears numerous properties, such as biocompatibility, biodegradability and non-toxicity making it suitable for use in different biomedical fields. Zinc (Zn) is required for fibroblasts proliferation and collagen synthesis as essential elements of wound healing. Its nanoparticles are well known for their capability to enhance wound healing by cell adhesion and migration improvement through growth factors-mediated mechanisms. Poor blood supply and unique histological characteristics of tendon make its regeneration always slow. Also, adhesion formation between tendon and its surrounding tissues is another problem for neotendon to return to its normal structure and functional activities. In this study, a novel tubular scaffold of zinc oxide (ZnO) nanoparticles loaded chitosan has been fabricated for tendon repair. Experimental complete tenotomy of deep digital flexor tendon in a rabbit model was done and scaffolds were placed in the transected area after two ends suturing. After four and eight weeks, adhesion formation around the tendons and tissue reaction to the scaffolds were evaluated macroscopically. Inflammation, angiogenesis and collagen fibers arrangement were also analyzed in histopathological evaluations. After eight weeks, the scaffolds were absorbed completely, adhesions around the tendon were decreased and there was no sign of significant tissue reaction and/or infection in histopathological analyses. The reduced adhesion formation, improved gliding function and better histopathological characteristics suggest this scaffold application as a potential therapy in treatment of tendon acute injuries.

Abstract The microorganisms have been noted as the main cause of delayed wound healing.The most common pathogen causing the wound infections is Staphylococcus aureus. Silver nanoparticles (AgNPs) show ample antibacterial activities. In the present study, the effect of AgNPs on mouse wounds inoculated with S. aureus was investigated. Sixty male mice (20 to 30 g) were anesthetized, full-thickness skin wounds were made on their back and then the bacterial suspension was added to each wound bed. Treatments were administered on wound bed topically including gentamicin (8 mg kg^-1), AgNPs (0.08 mg kg^-1, 0.04 mg kg^-1 and 0.02 mg kg^-1) and normal saline in the control group. Wound healing was monitored macroscopically by taking digital photographs on days 0, 7, 14 and 21 of the experiment. Topical application of gentamicin and AgNPs (0.08 and 0.04 mg kg^-1) significantly increased the rate of wound healing more than treatment with AgNPs at a dose of 0.02 mg kg^-1and normal saline. The presence of silver nanoparticles in AgNPs groups (especially 0.08 mg kg^-1) improved wound appearance better than other groups without silver nanoparticles (gentamicin and control groups) and led to lesser wound scars. According to data analysis, healing rate of treated mice with gentamicin and AgNPs (0.08 mg kg^-1) was significantly (p < 0.001) faster than treated mice with other AgNPs doses and normal saline. The results of current study introduced an in vivo nanosilver accelerating effects on the treatment of on S. aureus infected skin wounds.

Abstract Tendon never restores the complete biological and mechanical properties after healing. Several techniques are available for tissue-engineered biological augmentation for tendon healing like stem cells. Recently, synovium has been investigated as a source of cells for tissue engineering. In the present study, we investigated potentials of fibroblast like synoviocytes (FLSs) in tendon healing. Sixteen rabbits were divided randomly into control and treatment groups. One rabbit was used as a donor of synovial membrane (synovium). The injury model was unilateral complete transection through the middle one third of deep digital flexor tendon (DDFT). Subsequently, the tendon stumps were sutured with 3/0 nylon. In treatment group, 0.1 mL phosphate-buffered saline (PBS) solution containing 1 × 10⁶ nucleated cells of FLSs was injected intratendinously at both tendon stumps just next to incision line. In control group, 0.1 mL PBS without FLSs was used for intratendinous injection. Model animals were euthanized at eight weeks, DDFTs were harvested and prepared for biomechanical study. Results of study showed that, there was no significant differences in biomechanical parameters values between FLSs treated and control groups. In conclusion, intratendinous injection of FLSs did not improve biomechanical properties during eight weeks in rabbit.

Abstract Thirty six Wistar albino rats with implant induced endometriosis were randomly divided into six groups of six animals each. The rats in the first group received nothing and were euthanized at day 21. In the second group, rats received nothing and were euthanized at day 36. The third group received atorvastatin (ATV; 5 mg kg^-1 per day, orally) until 21 days from induction of endometriosis, and the fourth group received ATV from the 15^th day after induction of endometriosis for 21 days. The fifth group received grape seed extract (GET; 450 mg kg^-1 per day, orally) until 21 days from induction of endometriosis. In the sixth group, GET was administered from the 15^th day after induction of endometriosis for 21 days. The estrogen receptor positive cells (ER+) distribution and angiogenesis were assessed using immunohistochemical and immunoflourescent analyzes, respectively. The active cells with intracytoplasmic carbohydrate content were analyzed. Erα mRNA expression was assessed using semiquantitative real time-PCR and the tissue levels of malondialdehyde (MDA), glutathione peroxidase (GSH-px) and superoxide dismutase (SOD) were evaluated. The GET and ATV-treated animals showed significant reduction in endometriosis-increased ER+ cells distribution as well as significant decrease in Erα mRNA levels (p < 0.05). Our data suggests that GET exerts a potent inhibitory effect on development of endometriotic implants similar to ATV.

Abstract Adonis aestivalis (summer pheasant-eye) is an annual plant with a crimson flower, distributed in southern Europe and Asia. The plant has large buttercup-like blossoms and soft, fern-like leaves. It blooms in spring and is often found as a weed in cereal fields. Like other Adonis spp., the plant produces cardiac glycosides. It is used in remedies for mild weakness of the heart, especially when accompanied by nervous complaints. Cardiovascular and toxic effects of a hydroalcoholic extract from the aerial parts of A. aestivalis were investigated in sheep and mice. Six male sheep were anesthetized with sodium pentobarbital and arterial blood pressure was measured with a transducer connected to the left femoral artery. Heart rate and electrocardiogram (ECG) were registered from lead base-apex ECG derivatives connected to a Powerlab recorder. Three successive equal doses (75 mg kg-1) of the hydroalcoholic extract of A. aestivalis intravenously administered to anesthetized sheep. Adonis aestivalis extract induced a significant bradycardia and hypotension in sheep. Various ECG abnormalities in sheep included sinus arrhythmia, shortened and depressed S-T interval, and absence of P wave and flattened or inverted T wave. In addition, ventricular arrhythmias, bradyarrhythmias, atrioventricular block, ventricular premature beats, ventricular tachycardia and ventricular fibrillation have also been observed. The acute intraperitoneal toxicity (LD50) of the extract in mice was 2150 mg kg-1. In conclusion, bradycardia and ECG alterations induced by the extract could explain the justification of traditional use of the of Adonis aestivalis in treating cardiovascular insufficiency.

Abstract Tendons are frequently targets of injury in sports and work. Whether nonsteroidal anti-inflammatory drugs (NSAIDs) have beneficial effects on tendon healing is still a matter of debate. This study was conducted to evaluate effects of flunixin meglumine (FM) on tendon healing after experimentally induced acute trauma. Twenty eight adult male New Zealand White rabbits were subjected to complete transection of deep digital flexor tendons followed by suture placement. Treatment group received intramuscular injection of FM for three days, and controls received placebo. Subsequently, cast immobilization was continued for two weeks. Animals were sacrificed four weeks after surgery and tissue samples were taken. The histological evaluations revealed improved structural characteristics of neotendon formation including fibrillar linearity, fibrillar continuity and neovascularization in treatment group compared to those of controls (p < 0.05). However, no significant differences were found between two groups in terms of epitenon thickness (p > 0.05). Mechanical evaluation revealed significant increase in load-related material properties including ultimate load, yield load, energy absorption and ultimate stress in treatment group compared to those of control group (p < 0.05). However, no statistically significant differences in terms of stiffness and ultimate strain were found (p > 0.05). The present study showed that intramuscular injection of FM resulted in improved structural and mechanical properties of tendon repairs and it could be an effective treatment for acute tendon injuries like severance and laceration.

Abstract Healing of skin wound is a multi-factorial and complex process. Proper treatment of diabetic wounds is still a major clinical challenge. Although diabetes mellitus can occur in ruminants, healing of wounds in diabetic ruminants has not yet been investigated. The aim of this study was to evaluate healing of ovine excisional diabetic wound model. Eight 4-month-old Iranian Makoui wethers were equally divided to diabetic and nondiabetic groups. Alloxan monohydrate (60 mg kg^-1, IV) was used for diabetes induction. In each wether, an excisional wound was created on the dorsum of the animal. Photographs were taken in distinct times for planimetric evaluation. Wound samples were taken on day 21 post-wounding for histopathologic evaluations of epidermal thickness, number of fibroblasts and number of new blood vessels. The planimetric study showed slightly delay in wound closure of diabetic animals, however, it was not significantly different from nondiabetic wounds (p ≥ 0.05). Furthermore, epidermal thickness, number of fibroblasts and number of blood vessels were significantly lower in diabetic group (p < 0.05). We concluded that healing of excisional diabetic wounds in sheep may be compromised, as seen in other species. However, contraction rate of these wounds may not be delayed due to metabolic features of ruminants and these animals might go under surgeries without any serious concern. However, healing quality of these wounds may be lower than normal wounds.

Abstract This prospective study aimed to compare the intraosseous (IO) and intravenous (IV) effects of propofol on selected blood parameters and physiological variables during general anesthesia in rabbits. Thirty New Zealand White rabbits were studied. Six rabbits received IV propofol (group 1) and another 6 rabbits, were injected propofol intraosseously (Group 2) for 30 minutes (experimental groups). Rabbits of the third and fourth groups received IV and IO normal saline at the same volume given to the experimental groups, respectively. In the fifth group IO cannulation was performed but neither propofol nor normal saline were administered. Blood profiles were assayed before induction and after recovery of anesthesia. Heart and respiratory rates, rectal temperature, saturation of peripheral oxygen and mean arterial blood pressure were recorded. Heart rate increased significantly 1 to 5 minutes after induction of anesthesia in experimental groups (P < 0.05). Although mean arterial blood pressure decreased significantly from baseline, values remained above 60 mm Hg (P < 0.05). Respiratory rate decreased significantly in experimental groups, but remained higher in group 2 (P < 0.05). The lymphocyte count decreased significantly in group 1 (P < 0.05). The concentration of alkaline phosphatase in all rabbits, aspartate aminotransferase and gamma-glutamyl transferase in the first group and gamma-glutamyl transferase in the third group increased significantly (P < 0.05). Total bilirubin decreased significantly in group 2 (P < 0.05). All measured values remained within normal limits. Based on the least significant physiological, hematological and biochemical effects, the IO injection of propofol appears to be safe and suitable method of anesthesia in rabbits with limited vascular access.

Abstract Tendon never restores the complete biological and mechanical properties after healing. Bone marrow and recently adipose tissue have been used as the sources of mesenchymal stem cells, which have been proven to enhance tendon healing. Stromal vascular fraction (SVF), derived from adipose tissue by an enzymatic digestion, represents an alternative source of multipotent cells, which undergo differentiation into multiple lineages to be used in regenerative medicine. In the present study, we investigated potentials of this source on tendon healing. Twenty rabbits were divided into control and treatment groups. Five rabbits were used as donors of adipose tissue. The injury model was unilateral complete transection through the middle one third of deep digital flexor tendon. Immediately after suture repair, either fresh stromal vascular fraction from enzymatic digestion of adipose tissue or placebo was intratendinously injected into the suture site in treatments and controls, respectively. Cast immobilization was continued for two weeks after surgery. Animals were sacrificed at the third week and tendons underwent histological, immunohistochemical, and mechanical evaluations. By histology, improved fibrillar organization and remodeling of neotendon were observed in treatment group. Immunohistochemistry revealed an insignificant increase in collagen type III and I expression in treatments over controls. Mechanical testing showed significant increase in maximum load and energy absorption in SVF treated tendons. The present study showed that intratendinous injection of uncultured adipose derived stromal vascular fraction improved structural and mechanical properties of repaired tendon and it could be an effective modality for treating tendon laceration.

Abstract This study was designed to clarify bilaterally effect of long-time varicocele on left and right testes and to identify the effect of varicocele on maturation divisions during spermatogenesis. Moreover, the percentage of seminiferous tubules (STs) with I-VIII and IX-XIV stages of spermatogenesis and sperm parameters such as sperm motility and abnormality types were evaluated. The left varicocele was induced in test group (n=18) and control-sham animals (n=6) were gone under simple laparatomy. The test group further sub-divided into three subgroups based on the duration of varicocele (4, 6 and 8 months after varicocele induction). The histological alterations, spermiogenesis index (SPI), Sertoli cells (SCs), cytoplasmic lipid and alkaline phosphatase (ALP), germinal cells first and second maturation divisions, spermatogenesis stages, natural mating and sperm characteristics (count, motility and abnormality) were evaluated. Histological results showed that the varicocele-induced damage affected both stages of I-VIII and IX-XIV and up to 20% of the STs exhibited negative SPI and SCs degeneration. After 8 months, majority of STs demonstrated a remarkable reduction in the first and second maturation division in both of the testes. Nevertheless, the right testicles were manifested with significantly (P < 0.05) lower detrimental features in comparison with the left ones. Following varicocele induction the sperm count, viability and motility reduced time-dependently. Our data suggested that monolateral varicocele-induction affected both right and left testicles simultaneously albeit with differences. The varicocele-induced injuries were manifested as negative SPI and SCs degeneration, which may have led to poor sperm quantity and quality.