Search Results (229)

Introduction: Given the impact of aneurysmal subarachnoid hemorrhage (aSAH) on patients’ health, preclinical research is substantial to understand its pathophysiology and improve treatment strategies, which necessitates reliable and comprehensive animal models. Traditionally, aSAH models utilize iliac or subclavian access for angiography, requiring invasive procedures that are associated with significant risks and animal burden. This pilot study explores a less invasive method of digital subtraction angiography (DSA) by using the auricular artery (AA) as an alternative access point. Our aim was to demonstrate the feasibility of this refined technique, with the intention of reducing procedural risks, providing shorter operation times with enhanced neurological recovery, and simplifying the process for both researchers and animals. Materials and Methods: In this study, six female New Zealand white rabbits (3.2–4.1 kg body weight) underwent experimental induction of aSAH via a subclavian-cisternal shunt. The initial steps of this procedure followed traditional techniques, consisting of subclavian access through microsurgical preparation, followed by DSA to analyze retrograde filling of the basilar artery (BA). To evaluate the alternative method, on day 3 after induction of aSAH, DSA was performed via the AA instead of the traditional subclavian or femoral access. A catheter was placed in the AA to allow retrograde filling of the BA. This approach aimed to simplify the procedure while maintaining comparable imaging quality. Results: All rabbits survived until the study endpoint. Postoperatively, two rabbits showed signs of hemisyndrome, which significantly improved by the time of follow-up. No additional morbidities were observed. Upon euthanasia and necropsy, all animals showed clear subarachnoid bleeding patterns. DSA via the AA produced strong contrasting of the BA comparable to the traditional method. Conclusions: This technical note presents an initial evaluation of AA access as a feasible and potentially advantageous method for DSA in a rabbit model of blood shunt subarachnoid hemorrhage. The method shows promise in reducing invasiveness and procedural complexity, but further studies are required to fully establish its efficacy and safety. Future research should focus on expanding the sample size, refining the anatomical understanding of the AA, and continuing to align with ethical considerations regarding animal welfare. Full article

This study evaluated the bone regeneration effect and mechanical properties of “Sticky bone”, a mixture of platelet-rich fibrin (PRF) and synthetic bone grafts (SBGs), in the repair of large femoral bone defects in rabbits. Eighteen New Zealand white rabbits were included and randomly divided into a Sticky bone group and an SBG alone group. Bone graft samples were collected and analyzed at 4, 8, and 12 weeks after surgery. Micro- computed tomography (CT) analysis showed that the amount of the Sticky bone group in the grayscale ranges of 255–140 (highly mineralized tissue or unabsorbed bone powder) and 140–90 (representing new cancellous bone) was higher than that of the SBG group at each time point and decreased with the number of weeks. The compression strength test showed that the average compression strength of the Sticky bone group reached 5.17 MPa at the 12th week, which was 1.62 times that of the intact bone (3.19 MPa) and was significantly better than that of the SBG group (about 4.12 MPa). This study also confirmed for the first time that the use of a new polyethylene terephthalate (PET) blood collection tube to prepare PRF can stably release key growth factors such as platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor (VEGF), which are conducive to early bone vascularization and cell proliferation. In summary, Sticky bone has the potential to promote bone formation, enhance tissue integration and mechanical stability, and can be used as an effective alternative material for repairing large-scale bone defects in clinical practice in the future. Full article

Background/Objectives: Opioid use disorder (OUD) remains a severe health problem globally, resulting in substantial social and economic challenges. While existing medications for managing OUD are proven to be effective, they also present certain challenges. A vaccine offers a promising therapeutic strategy to combat OUD and potentially reduce the risk of overdose death. The TT-6-AmHap heroin conjugate vaccine has effectively reduced heroin-induced pharmacological effects in behavioral assays as well as demonstrated the induction of high titer and high affinity antibody responses in mice and rats. In this GLP study conducted in rabbits, the potential local and systemic toxicity of the TT-6-AmHap heroin vaccine in combination with or without adjuvants ALF43 and Alhydrogel^® (ALFA) was investigated. Methods: Male and female New Zealand White rabbits were administered with vaccines or a saline control intramuscularly at two-week intervals over a 57-day study period. The presence, persistence or reversibility of any toxic effects of the vaccine was determined over a four-week recovery period. Results: Administration of TT-6-AmHap with or without the adjuvants induced high antibody-specific IgG in treatment groups compared to the controls. The study found no TT-6-AmHap-related effects on mortality, physical examinations, dermal Draize observations, body weights, body weight changes, food consumption, ophthalmology, clinical pathology (hematology, coagulation, clinical chemistry, and urinalysis), macroscopic pathology, or organ weights. Conclusions: Under the conditions of this study, these results demonstrate that the TT-6-AmHap vaccine with or without adjuvants was well tolerated, immunogenic, and the effects were not considered adverse in both male and female rabbits. Full article

Current treatment strategies for partial tendon tears often lack the capacity to promote true tissue regeneration and improve long-term clinical outcomes. This study tested the hypothesis that treatment of a partial defect in the rabbit common calcaneus tendon (CCT) with uncultured, unmodified, autologous, adipose-derived regenerative cells (UA-ADRCs) enables regenerative healing without scar formation. A full-thickness, 3 mm defect was produced in the midsubstance of the right gastrocnemius tendon, a component of the CCT, in adult female New Zealand white rabbits. Animals received either an injection of 28.3 × 10⁶ UA-ADRCs in 0.5 mL Ringer’s lactated solution (RLS) or saline, or RLS or saline alone as sham treatment. Tendons were analyzed 4 or 12 weeks post-treatment using histology, immunohistochemistry and non-destructive biomechanical testing. UA-ADRC-treated tendons showed newly formed connective tissue consistent with tendon regeneration, whereas sham-treated tendons developed scar tissue. Biomechanical testing showed significantly higher percent relaxation in UA-ADRC-treated tendons compared to sham controls (p < 0.05), indicating greater viscoelasticity characteristic of healthy or well-integrated tissue. Together, these findings suggest that UA-ADRC therapy may provide a regenerative, structure-modifying treatment for partial tendon tears. Full article

This study evaluated the effects of dietary supplementation with omega-3 polyunsaturated fatty acids from extruded linseed, alone and combined with Padina pavonica algae extract, on growth performance and metabolic status in fattening rabbits. Sixty New Zealand White rabbits were assigned to three groups, as follows: control (CNT), L (5% linseed), and LPP (3.5% linseed + 0.2% algae extract) from weaning (37 days) to slaughter (85 days). Productive performance was assessed through body weight (BW), average daily gain (ADG), feed conversion ratio (FCR), and feed intake (FI). Blood was sampled at weaning, 60 days, and slaughter and analyzed for insulin, leptin, cortisol, thyroid hormones (T3, T4), glucose, and non-esterified fatty acids (NEFAs). The L group showed significantly higher ADG (41.0 ± 1 g/d) and improved FCR (4.1 ± 0.2) compared to LPP (ADG: 37 ± 1 g/d, FCR: 4.6 ± 0.2; p = 0.001). No differences were observed in final BW or FI among groups (p < 0.001). Insulin peaked at 60 days across all groups (p < 0.001), with the LPP group showing the lowest levels (9.8 ± 0.9 µUI/mL; p = 0.043). T3 and T4 increased significantly with age (p < 0.001), and the T3/T4 ratio varied by diet and time (p = 0.005). Cortisol rose only at slaughter (p < 0.001) and negatively correlated with insulin and thyroid hormones. The results suggest that omega-3-rich nutraceuticals can enhance growth performance without disrupting metabolic balance and may modulate specific hormonal responses due to their bioactive compounds. Full article

Background/Objectives: Artificial tendons offer an alternative to biological tendon grafts and may restore normative biomechanical functions in humans and animals suffering segmental or complete tendon loss. The aim of this study was to quantify movement biomechanics during hopping gait and muscle properties of New Zealand White rabbits with a polyester silicone-coated (PET-SI) artificial tendon. Methods: In five rabbits, the biological Achilles tendon of the left hindlimb was surgically replaced with a PET-SI artificial tendon; five operated control rabbits underwent complete surgical excision of the biological Achilles tendon in the left hindlimb with no replacement (TE). Results: Across both groups at 2 and 8 weeks post-surgery compared to baseline, the maximum ankle angle during stance and swing phases of stride was significantly lower (i.e., more dorsiflexed) (p < 0.001), the peak vertical force was significantly higher (p < 0.001), and the average ground contact area was significantly lower (p < 0.001). At 8 weeks post-surgery, the muscle cross-sectional area of the lateral gastrocnemius was significantly higher in the PET-SI group than in the TE group (p = 0.006). Muscle mass and length were lower in the operated limb compared to the non-operated limb across the two groups (TE and PET-SI), with no significant differences between groups. Conclusions: The artificial Achilles tendon did not appear to provide superior biomechanical support during hopping compared to the TE group. However, the artificial tendon preserved muscle structural properties that correspond to the muscle’s capacity to generate force. Future studies should optimize the tendon–tissue interface. Full article

Goji berries (Lycium barbarum), rich in antioxidant and immunomodulatory compounds, have shown potential benefits for male reproductive health. This study aimed to evaluate the impact of dietary Goji berry (GB) supplementation on immune-related and antioxidant gene expression in the male reproductive tract of rabbits. Eighteen 7-month-old New Zealand White rabbit bucks were randomly assigned to two groups: a control group (n = 9) receiving a standard diet, and a Goji group (n = 9) receiving the same diet supplemented with 1% GB. After 60 days of nutritional adaptation and then 60 days of treatment, tissues from the testes, epididymis, seminal vesicles, prostate, and bulbourethral glands were collected and analyzed using quantitative real-time PCR. Gene expression analysis focused on immune markers (TLR4, IL-1β, IL-10, and TNFα) and antioxidant enzymes (SOD1, CAT, and GPX). Significant modulation was observed only in the epididymis, where TLR4 and GPX were significantly downregulated in the Goji group (p = 0.0274 and p = 0.007, respectively), while IL-1β and TNFα showed a downward trend. No significant differences were found in the other tissues. These results suggest that Goji berry supplementation exerts tissue-specific effects, particularly in the epididymis, by modulating inflammation and oxidative stress. This supports its potential use as a natural nutraceutical strategy to enhance male fertility in rabbits. Full article

Buprenorphine has gained widespread popularity for use in rabbits, while much less is known about methadone. Our aim was to compare sedative, analgesic, and respiratory effects of methadone and buprenorphine as part of balanced anaesthesia. Forty-eight female New Zealand white rabbits undergoing calvaria defects were randomly equally assigned to receive either 0.03 mg kg⁻¹ of buprenorphine (group B) or 0.3 mg kg⁻¹ of methadone (group M) in combination with 15 mg kg⁻¹ of ketamine and 0.1 mg kg⁻¹ of dexmedetomidine SC. Fifteen minutes later, sedation was scored. A laryngeal mask was placed, and inhalational anaesthesia started. Rescue intraoperative analgesia was administered based on autonomic variations. Arterial blood gases were analysed intra- and postoperatively. Postoperative analgesia was administered if the Rabbit Grimace Scale (RbtGS) score was ≥4. The Mann–Whitney test, t-test, and relative risk followed by chi-square test were used to compare the treatment groups. Deeper sedation was observed in rabbits of group M than in those of group B. Rescue analgesia was administered intraoperatively to seven animals in group B and five in group M (p = 0.739) and postoperatively to three in group B and twelve in group M (p = 0.013). Rabbits of both groups showed short-term respiratory acidosis. RbtGS scores indicated better and longer analgesia in group B compared to group M. Full article

This study was conducted on New Zealand White male and female rabbits over a period of 133 days to ascertain their potential growth rates, body composition for major body parts, and chemical makeup. A total of 220 New Zealand White rabbits, evenly distributed between males and females, were used for this study. One hundred rabbits for potential growth were weighed from day 14 to day 140, while twelve rabbits, six males and six females, were randomly selected at days 14, 21, 28, 35, 42, 56, 70, 84, 112, and 140 for carcass analysis. Although the rate of maturation was faster in females than in males, the Gompertz equation fitted separately to the growth data for males and females indicated that the body weights were similar throughout the trial (0.0243 vs. 0.0239), but males had a higher mature weight (315 g) than the females (309 g). Mature body protein weights averaged 1497 g in males and 843 g in females, and mature body lipid contents averaged 252 and 227 g, respectively. The rate of maturation per day of pelt-free body protein of males and females was 0.0103 and 0.0172, while that of body lipids was 0.0410 and 0.0471, respectively. Separate equations were required for males and females to describe the allometric relationship between protein and lipids in the pelt-free body. The rate of maturation of pelts in females was higher than in males (0.0249 vs. 0.0214/d), and the mature weight was lower (456 vs. 523 g, respectively). Full article

This study evaluated the effect of two levels of extruded linseed (EL) in the diet on growth performance, carcass yield, and meat quality of growing rabbits. Sixty-nine New Zealand White male rabbits (Oryctolagus cuniculus) were assigned after weaning to three dietary groups: control (C), 2.5% EL (L2.5%), and 5% EL (L5%). At the end of the fattening period (from 37 to 93 days of age), rabbits were slaughtered. EL supplementation significantly reduced average daily weight gain (ADG) in the L5% group (p < 0.05), while other performance parameters were not significantly affected. Meat from the L5% group exhibited a higher fat content (p < 0.001) and lower water-holding capacity (p < 0.05) compared to the others. The fatty acid profile showed a significant increase in n-3 polyunsaturated fatty acids (PUFAs) and a decrease in n-6 PUFA (p < 0.05), resulting in a markedly reduced n-6/n-3 ratio (p < 0.001) in supplemented groups. EL supplementation also enhanced long-chain n-3 PUFA levels, particularly docosapentaenoic acid (DPA). Although lipid oxidation was slightly increased (p < 0.05), sensory attributes remained unaffected. These findings support EL supplementation as a nutritional strategy to increase the n-3 fatty acids in rabbit meat without compromising physical and sensory quality. Full article

Hemoglobin-based oxygen carriers (HBOCs) represent a promising alternative to traditional blood transfusions, offering the advantages of extended shelf life and avoiding blood compatibility limitations and infection risks. Positive effects of hemoglobin-based oxygen carriers (HBOCs) on hemorrhagic shock have been researched across various animal species, including swine, rats, rabbits, guinea pigs, and dogs. As previously described, HBOCs based on ovine hemoglobin display better efficiency in the context of hemorrhagic shock compared to those based on the more commonly used bovine hemoglobin. This was evidenced through higher survival rates and more favorable histopathological and immunological outcomes. The vascular effects of ovine hemoglobin polymerized with glutaraldehyde exposure included the absence of hypertension, minimal endothelial damage with slight alterations in inducible nitric oxide synthase (iNOS), and reduced vascular inflammation mediated by interleukin-10 (IL-10). Ovine hemoglobin has emerged as a particularly promising raw material for the development of HBOCs, surpassing bovine and human hemoglobin due to its advantages in availability and efficacy. Furthermore, reducing oxidative stress by polymerizing hemoglobin with glutaraldehyde is most effective with ovine hemoglobin compared to bovine hemoglobin. This study evaluates the effectiveness of ovine hemoglobin polymerized with glutaraldehyde in managing hemorrhagic shock in rabbits, with a focus on its ability to maintain blood pressure, support oxygen transport, and assess potential systemic and oxidative responses. Fifteen adult New Zealand white rabbits, divided into three equal groups, were included in this study: a negative control group transfused with colloid solutions, a positive control group treated with autotransfusion, and a group receiving HBOCs. All groups underwent a hemorrhagic shock protocol, with 40% of their total blood volume withdrawn under deep anesthesia, followed by transfusions 30 min later. Vital parameters, including invasive arterial blood pressure, heart rate, and end-tidal CO₂, were measured throughout the experimental procedures. Arterial blood gas samples were collected before the procedures, after hemorrhagic shock induction, and at the conclusion of the transfusion. In summary, HBOCs offer a promising solution for oxygen delivery, but their effects on blood chemistry, particularly CO₂ and lactate levels, must be considered. Although no direct oxygenation issues were observed in experimental models, elevated CO₂ levels and the interference of HBOCs with lactate measurements emphasize the importance of vigilant clinical monitoring. Polymerized hemoglobin provides a non-nephrotoxic alternative, but challenges persist in preventing nitric oxide scavenging and ensuring effective oxygen delivery. Full article

Extensive bone loss represents a great challenge for orthopedic and reconstructive surgery. On an in vivo rabbit model, the healing of two bone defects on a long bone, tibia, was studied. A polybutylene succinate (PBS) microfibrillar scaffold was implemented with BMP-2 protein and hydroxyapatite (HA) as potential osteogenic factors. The present study was carried out on 6 male New Zealand white (4–6 months old) rabbits in vivo model. One bone defect was created in each subject on the tibia. The controls were left to heal spontaneously while the study samples were treated with the polybutylene succinate (PBS) microfibrillar scaffolds doped with BMP-2 and HA. Histological and immunohistochemical analyses were performed after euthanasia at 3 and 6 months. The bone defect treated with the BMP-2 PBS scaffold shows, from 3 months, a significantly increased presence of activated osteoblasts with mineralized bone tissue deposition. This study confirms the great potential of PBS scaffolds in the clinical treatment of bone defects. Full article

Unmodified Ti6Al4V can osseointegrate, but sometimes this capacity needs to be improved. This study aimed to see how much porosity improves osseointegration in a Ti6Al4V implant. Three types of Ti6Al4V cylindrical-shaped implants (13.00 mm length × 5.00 mm diameter) were evaluated: solid sandblasted acid-etched, sintered, and porous 3D-printed (681.00 µm average pore size). Fifteen 20-week-old nullipara female parasite-free New Zealand California white rabbits were used, employing the femoral condyle defect model and undertaking µ-CT analysis and pull-out testing eight weeks later. On µ-CT densitometric analysis, the solid sandblasted rod showed the highest new bone growth around the implant. Bone growth was higher inside the implants for the porous 3D-printed (54.00 ± 5.00 mm³) than for the sintered (1.00 ± 0.05 mm³) and zero for the sandblasted implants. In the pull-out test, there were no statistically significant differences in the ANOVA analysis between the sintered (900.00 N ± 310.00 N) and porous 3D-printed (700.00 N ± 220.00 N) implants. Such differences did exist between the sandblasted material (220.00 N ± 50.00 N) and the two other materials (sintered p 0.002, porous p 0.034). The porous 3D-printed and sintered implant pull-out strength were significantly better than that of the solid rod sandblasted implant. Still, there were no statistically significant differences between the first two. Full article

For plant-derived raw materials, there are very few studies regarding the effect of intraocular administration on intraocular pressure (IOP) and associated blood flow. Traditional folk medicine uses many natural resources for eye disorders. However, in the main, these exhibit an anti-inflammatory and moisturizing effect. The intraocular pressure reduction and neuroprotective effects are known, but only for orally administered products. In the work presented here, the effect of eight natural iridoids in concentrations of 0.1 and 0.5% in saline on IOP and blood flow in iris vessels was studied in white New Zealand rabbits. No ocular adverse effects were observed during the whole experiment. We demonstrated, for the first time, significant reductions in IOP for five of the eight iridoids tested at a concentration of 0.5%. These were verbenalin, aucubin, oleuropein, gentiopicroside, and secologanin. The highest effect of IOP lowering, a nearly 1.5 mmHg difference from baseline, was observed for verbenalin 2 h after administration. An increase in vascular inflow was observed only with the administration of aucubin, catalpol, and gentiopicroside at 2 and 3 h after administration of the 0.5% solution. This effect was contrary to the result for the reference—timolol—which significantly reduced flow by more than 100 flux during the first hours of the experiment. In summary, selected iridoids could be considered, after further investigation, as natural components for ophthalmic formulation in the prevention of eye diseases. Full article

Background: Segmental bone defects (SBDs) pose significant clinical challenges, often requiring complex reconstructive procedures. Degradable bone substitutes loaded with antibiotics have emerged as promising tools for infection control. However, their impact on bone healing remains uncertain. This study investigates antibiotic-loaded biodegradable scaffolds in infected defects using an in vivo rabbit model. Methods: Thirty New Zealand white rabbits were divided into three groups—antibiotic-loaded GreenBone scaffolds, non-loaded GreenBone scaffolds, and allografts. A critical-size femoral defect was surgically created and inoculated with Staphylococcus epidermidis. Radiographic evaluations were performed over 16 weeks, followed by histological and microbiological analyses. Bone union, infection rates, and callus maturation were assessed. Results: Eight rabbits were excluded for technical errors. Bone union was significantly lower in the antibiotic-loaded group (two rabbits out of seven; 28.6%) compared to the non-loaded scaffold (13 rabbits out of 15; 86.7%; p = 0.006). The antibiotic-loaded group exhibited a higher incidence of chronic osteomyelitis (100%) versus non-loaded implants (60%; p < 0.05). Histological evaluation revealed delayed bone maturation in the antibiotic-loaded group (22.2% HOES grade 3) compared to non-loaded scaffolds (69.5%; p < 0.001). Conclusions: Despite their infection-fighting potential, antibiotic-loaded biodegradable scaffolds may impair bone healing, leading to higher non-union rates and delayed maturation. These findings highlight a critical trade-off between local antibiotic therapy and bone regeneration, warranting careful clinical consideration and further research to optimize treatment strategies for infected bone defects. Full article