Male Rabbits Research Articles

Evaluation of biocompatibility of Commercial Pure Titanium / Bioactive Glass Ceramic Functionally Graded Material as Dental Implant Material In-Vivo study

Background: the ultimate goal of modern implantology is fine and fast osseointegration which is a major factor influencing the success of dental implantation, and the optimum circumstances of it the biointegration which is the occurrence of continuity of ceramic implant to bone without intervening space. 
 Material and method: Two groups of cylindrical implant specimens were prepared from functionally graded material and commercial pure titanium. Each group composed of 40 implant specimens. The femur of 20 white male New Zealand rabbits, were chosen as implantation sites. Push out test was performed to measure bone bonding strength between implant specimen and bone after 2 and 4 weeks healing periods (10 rabbits for each periods). For each time interval 20 implant specimens for each group, which implanted in rabbits. Histological study for evaluation of tissue response and histomorphometric analysis was performed for measurement of new bone area at two time intervals.
 Result: the results of push out force and new bone formation area appeared that mean values of functionally graded material implant specimens were a statistically highly significant more than that of commercial pure titanium implant specimens after 2 weeks and 4 weeks of implantation. In histological examination, there was an active osteoid tissue around functionally graded material implants and hematopoietic tissues around commercial pure titanium implants after 2 weeks, and there was an osteoid maturation with observation of reversal lines around functionally graded material implants and new bone formation with osteocyte around commercial pure titanium implants after 4 weeks of implantation.

Microvascular permeability and texture analysis of bone marrow in diabetic rabbits with critical limb ischemia based on dynamic contrast-enhanced magnetic resonance imaging.

Early on in the development of diabetes, skeletal muscles can exhibit microarchitectural changes that can be detected using texture analysis (TA) based on volume transfer constant (Ktrans) maps. Nevertheless, there have been few studies and thus we evaluated microvascular permeability and the TA of the bone marrow in diabetics with critical limb ischemia (CLI). Eighteen male rabbits were randomly assigned equally into an operation group with hindlimb ischemia and diabetes, a sham-operated group with diabetes only, and a control group. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) was performed on all rabbits at predetermined intervals (1, 5, 10, 15, 20, and 25 days post-surgery). The pharmacokinetic model was used to generate the permeability parameters, while the textural parameters were derived from the Ktrans map. Data analysis methods included the independent sample t-test, Mann-Whitney U test, repeated-measures analysis of variance, and Pearson correlation tests. The Ktrans values reached a minimum on day 1 after ischemia induction, then gradually recovered, but remained lower than those of the sham-operated group. The volume fraction only showed a significant difference between the operation group and the sham-operated group on day 5 post-surgery, but not in the extravascular extracellular space volume fraction at all time points. A significantly reduced Ktrans on day 1, a decreased number of bone trabeculae (Tb.N), and the area of bone trabeculae (Tb.Ar), and an increased microvessel density on day 25 in the operation group compared with the sham-operated group were observed. At each time point, there was a discernible difference between the two groups in the mean value, mean of positive pixels, and sumAverage. The early stages of diabetic bone marrow with CLI can be evaluated by DCE-MRI for microvascular permeability. Texture analysis based on DCE-MRI could act as an imaging discriminator and new radiological analysis tool for critical limb ischemia in diabetes mellitus.

Construction of a near infrared fluorescence system for imaging of biological tissues.

Surgical procedures often rely on unaided visual observation or endoscopic assistance, which may pose challenges in cases involving intricate anatomical relationships. Real-time imaging technologies capable of intraoperative visualization of target organs have the potential to enhance the precision of surgical procedures by facilitating accurate identification, separation, and protection of vital tissues or organs. Despite these advantages, the widespread adoption of such technologies has been hindered by factors such as the prohibitive cost of equipment. This study aims to optimize and develop a device based on Indocyanine Green (ICG) for fluorescence imaging. The objective is to monitor changes in the average fluorescence intensity of ICG in the bladder, offering valuable guidance for surgeries involving the bladder. 1. Male rabbits were administered 0.01mg/ml ICG via the renal pelvis and ear vein to obtain fluorescence images of the ureter, bladder, and small intestine. 2. After ligating the bilateral ureters of male rabbits, a retrograde bladder perfusion of 5ml 0.01mg/ml ICG was conducted to capture fluorescence images of the bladder over time. The average fluorescence intensity was computed using Image Pro Plus 6.0, and the corresponding curve was generated using Prism 8.0. Using a similar methodology, the average fluorescence intensity of male rabbits without ureteral ligation was measured and plotted over time. 1. The developed device facilitated imaging of the ureter, bladder, and small intestine. 2. The bladder's average fluorescence intensity exhibited changes over time in response to urine production and ureteral ligation, contrasting with observations without ureteral ligation. We have successfully constructed and optimized a modular fluorescence imaging system for organs and tissues. This system proves effective in imaging experiments involving hollow organs in animals and offers valuable insights for relevant surgical procedures.

Increased serum levels of high-mobility group box 1 protein and the location characteristics in the patients of intracranial aneurysms

ObjectiveInflammation-related factors play a crucial role in intracranial aneurysms (IA) initiation, progression, and rupture. High mobility group box 1 (HMGB-1) serves as an alarm to drive the pathogenesis of the inflammatory disease. This study aimed to evaluate the role of HMGB-1 in IA and explore the correlation with other inflammatory-related factors. MethodsA total of twenty-eight adult male Japanese white rabbits were included in with elastase-induced aneurysms, n = 18) and the control group (normal rabbits, n = 10). To assess the expression of HMGB-1, both reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) was performed on serum samples obtained from human subjects (10 patients with IA and 10 healthy donors) as well as from rabbits (aneurysm group and control group). Immunohistochemistry and immunofluorescence were employed to evaluate the expression levels of elastic fibers, HMGB-1, tumor necrosis factor-alpha (TNF-α), and triggering receptor expressed on myeloid cells-1 (TREM-1). ResultsThe expression of HMGB-1 was found to be significantly higher in the IA group compared to the control group, both at the mRNA and protein levels (P < 0.0001). Similar findings were observed in the rabbit aneurysm model group compared to the control group (P < 0.0001). HMGB-1 expression was observed to be more abundant in the inner wall of the aneurysm compared to the external wall, whereas in the control group, it was rarely scattered. Additionally, the localization patterns of TNF-α and TREM-1 exhibited similar characteristics to HMGB-1. ConclusionOur findings demonstrate that HMGB-1 is highly expressed in both IA patients and rabbit aneurysm models. Furthermore, the similar localization patterns of HMGB-1, TNF-α, and TREM-1 suggest their potential involvement in the inflammatory processes associated with IA. These results highlight the potential of HMGB-1 as a novel therapeutic target for IA.

Choosing the optimal concentration of dextran sulfate sodium for reproducing chemically induced colitis in rabbits

Background. Due to the fact that inflammatory bowel diseases (IBD) are widespread among the population, the development of new drugs for the treatment of IBD is a public health priority. Preclinical drug testing is inextricably linked with the modeling of IBD in laboratory animals. This study purpose was to develop a model of chemically induced colitis in rabbits. Methods. The study was performed on male rabbits of the “Soviet Chinchilla” breed. Colitis was simulated by oral administration of dextran sulfate sodium (DSS) in a concentration of 0.1% to 2% solution for five consecutive days. Euthanasia of laboratory animals was carried out on the seventh day, after the end of taking the DSS solution. A histological examination of the intestine was performed. Results. It was found that using 0.1% DSS solution allows to obtain a model of mild erosive colitis. The use of 0.5% DSS solution gave the intermediate severity of erosive ulcerative colitis. DSS concentration of more than 1% led to the development of severe ulcerative colitis in rabbits and the death rate of 71.4% among them. Conclusion. The obtained results indicate that the use of 0.5% DSS solution makes it possible to create a model of erosive ulcerative colitis in rabbits suitable for studying human IBD.

Hyperbaric oxygen therapy enhances graft healing and mechanical properties after anterior cruciate ligament reconstruction: An experimental study in rabbits.

Hyperbaric oxygen therapy (HBOT) has proven successful in wound healing. However, its potential effects on anterior cruciate ligament (ACL) injuries remain uncertain. This study aimed to investigate the impact of HBOT on graft healing following ACL reconstruction in rabbits. Male New Zealand rabbits underwent ACL reconstruction and were randomly divided into two groups: the HBOT group and the ambient air group. The HBOT group received 100% oxygen at 2.5 atmospheres absolute for 2 h daily for 5 consecutive days, starting from the first day after surgery. The ambient air group was maintained in normal room air throughout the entire period. After 12 weeks following the surgery, animals were euthanized, and their knees were harvested for analysis. The HBOT group demonstrated superior graft maturation and integration in comparison to the ambient air group, as evidenced by lower graft signal intensity on magnetic resonance imaging, decreased femoral and tibial tunnel size, and higher bone mineral density values on high-resolution peripheral quantitative computed tomography scans. Additionally, biomechanical testing indicated that the HBOT group had greater load to failure and stiffness values than the ambient air group. In conclusion, the adjuvant use of HBOT improved ACL graft maturation and integration, reduced tunnel widening, and enhanced the biomechanical properties of the graft. These results may provide important insights into the potential clinical application of HBOT as a therapeutic intervention to enhance graft healing after ACL reconstruction, paving the way for further research in this area.

Improved intervertebral fusion in LLIF rabbit model with a novel titanium cage

BACKGROUND CONTEXTThere is no established small animal approach model for the strict simulation of lateral lumbar interbody fusion (LLIF) surgery. PURPOSEThis study aims to establish a reliable LLIF rabbit model that strictly simulates the procedure and to preliminarily evaluate the differences in fusion outcomes with different graft materials. STUDY DESIGNA controlled laboratory. METHODSFifty-four 4-month-old white New Zealand female and male rabbits were selected and divided into five groups: Group A (dissection group) consisted of 9 rabbits, Group B (normal approach group) consisted of 9 rabbits, Group C (autogenous iliac bone group) consisted of 12 rabbits, Group D (BMP-2 carrier material group) consisted of 12 rabbits, and Group E (allograft bone group) consisted of 12 rabbits. Based on data from Group A, a novel titanium metal fusion device was designed. Postoperatively, at the 12-week mark, manual palpation was employed to compare the interbody fusion status among Groups B, C, D, and E. Specimens from Groups C, D, and E were subjected to Micro-CT scanning to compare various parameters such as trabecular bone volume (BV), bone volume fraction (BV/TV, BVF), and bone surface area (BS). Furthermore, a tissue histopathological examination was performed to observe the structure and morphology of newly formed bone within the fusion mass as well as the remodeling of the graft in each group. RESULTSBased on the measurements obtained from the dissection group, we designed a U-shaped interbody fusion device with dimensions of 10 mm in length, 2.5 mm in width, and 1.3 mm in height. In Group B, 9 cases exhibited intervertebral mobility. In Group C, 1 case showed nonfusion. In Group D, all cases achieved fusion. In Group E, 4 cases did not achieve fusion. Additionally, the Micro-CT results showed that the interbody fusion index scores were 4.64±0.50 in Group C, 4.33±0.65 in Group D, and 3.36±0.81 in Group E. There was no statistically significant difference in fusion index scores between Groups C and D (p=.853). Notably, Groups C and D had higher scores than Group E (p<.001). The trabecular bone volume (BV) in Groups C and D also showed no significant difference but was significantly higher than in Group E (p<.001). Furthermore, the histopathological results revealed that the specimens from Group E had less newly formed cartilage and bone compared to Groups C and D. CONCLUSIONSThis study successfully established a strict simulation of the clinical LLIF procedure in a rabbit model. Moreso, we conducted a preliminary validation indicating that the BMP-2 carrier material achieved interbody fusion outcomes similar to autogenous iliac bone. CLINICAL SIGNIFICANCEThe findings of this investigation from animal models provide a theoretical basis for the clinical use of BMP-2 to promote early spinal fusion in LLIF procedures. Importantly, the study provides a small animal model foundation for research related to LLIF surgery.

Hyperbaric Oxygen Therapy to Minimize Orthodontic Relapse in Rabbits.

The purpose of the present study was to discover how hyperbaric oxygen therapy (HBOT) could reduce orthodontic relapse by altering the expressions of hypoxia-inducible factor (HIF)-1 messenger ribonucleic acid (mRNA), type I collagen (Col I), and matrix metalloproteinase-1 (MMP-1) in the gingival supracrestal fibers in rabbits. This study involved 44 male rabbits (Oryctolagus cuniculus) randomly divided into the normal group (K0), the orthodontic group without HBOT (K1), and the orthodontic group with HBOT (K2). Following orthodontic separation of the two upper central incisors, a retention phase and relapse assessment were performed. The HBOT was performed for a period of 2, 4, 6, 8, and 10 days after retention. HIF-1α transcription was assessed employing real-time polymerase chain reaction, whereas Col I and MMP-1 proteins were examined using immunohistochemistry. The orthodontic relapse was measured clinically using a digital caliper. We used the one-way analysis of variance followed by Tukey's post hoc for multiple comparisons to measure differences between pairs of means; a p-value of 0.05 was considered statistically significant. HBOT significantly increased the HIF-1α mRNA expression (p = 0.0140), increased Col I (p = 0.0043) and MMP-1 (p = 0.0068) on the tensioned and pressured side of the gingival supracrestal fibers, respectively, and clinically decreased the relapse (p = 3.75 × 10-40). HBOT minimizes orthodontic relapse by influencing HIF-1α expression, collagen synthesis (Col I), and degradation (MMP-1). This result suggests that HBOT has the potential to be used as an adjunctive method in the orthodontic retention phase.

Сравнительный анализ эффективности пребиотических добавок в рационах кроликов на откорме

Purpose. Comparative study of the effect of prebiotic feed additives "Chlorelact" and "Lactuvet-1" on indicators of natural resistance and microflora of rabbit intestines. Materials and Methods. Scientific and practical experience was conducted on male rabbits of a hybrid breed using new lactulose-containing feed additives in the diet. The research was carried out using standardized methods in accredited laboratories. The reliability of the results is confirmed by their processing by statistical methods. Results. Diets supplemented with various levels of feed additives had a significant impact on some of the studied signs, especially immune responses, as well as antioxidant and hematobiochemical parameters. Thus, when comparing the level of bactericidal activity of blood serum (ALS) the superiority of animals of the experimental groups was revealed: I – by 3.0% (P≤0.001), II – by 2.07% (P≤0.01), over control rabbits. The results of determining the number of microorganisms in the blind processes of the intestines of animals showed that the number of microorganisms is the largest in the II experimental group that consumed the Chlorelact supplement, and prevails over their content in the blind processes of their peers. At the same time, in rabbits that consumed the studied additives, the superiority of the content of normal microflora over pathogenic relative to control was noted. Conclusion. According to the results of the conducted studies, the hypothesis has been experimentally confirmed that the use of chlorella as a natural feed additive in the diets of rabbits can improve their health, and, as a result, will allow in the future to abandon the use of antibiotics or growth-stimulating drugs during the fattening period.

THERMALLY DISINFECTED HUMAN FEMORAL HEAD AS SCAFFOLD FOR OSTEOINDUCTIVE SUBSTANCES

Various approaches have been implemented to enhance bone regeneration, including the utilization of autologous platelet-rich plasma and bone morphogenetic protein-2. The objective of this study was to evaluate the impact of Marburg Bone Bank-derived bone grafts in conjunction with platelet-rich plasma (PRP), recombinant human bone morphogenetic protein-2 (rhBMP-2), and zoledronic acid (ZA) on osteogenesis within rabbit bone defects.MethodologyBone defects (5mm in diameter) were created in the femurs of 96 male rabbits. The animals were allocated into five groups: (1) bone graft + PRP (BG + PRP), (2) bone graft + 5μg rhBMP-2 (BG + rhBMP-2), (3) bone graft + 5μg ZA (BG + ZA), (4) bone graft + 10μg rhBMP-2 + 5μg ZA (BG + rhBMP-2 + ZA), and (5) bone graft (BG). Marburg Bone Bank-processed human femoral head allografts were utilized for bone grafting. The rabbits were euthanized at 14-, 30-, and 60-days post-surgery, and their femurs underwent histopathological and histomorphometric assessments.ResultsHistomorphometric analysis revealed significantly enhanced de novo osteogenesis within the bone allografts in the BG + PRP and BG + rhBMP-2 groups compared to the BG, BG + ZA, and BG + rhBMP-2 + ZA groups at 14 and 30 days (p &lt; 0.05). However, on day 60, the BG + rhBMP-2 group exhibited elevated osteoclastic activity (early resorption). The local co-administration of ZA with thermally treated grafts impeded both bone graft resorption and new bone formation within the bone defect across all time points. The addition of ZA to BG + rhBMP-2 resulted in diminished osteogenic activity compared to the BG + rhBMP-2 group (p &lt; 0.000).ConclusionThe study findings indicated that the combination of PRP and rhBMP-2 with Marburg bone grafts facilitates early-stage osteogenesis in bone defect healing. Incorporating ZA into the thermally treated bone graft hinders both graft resorption and de novo bone formation.

NEAR INFRARED-RESPONSIVE HYDROGELS CONTAINING ADENOVIRAL VECTORS: APPLICATION IN BONE REGENERATION

We have developed plasmonic fibrin-based hydrogels that incorporate gold nanoparticles which transduce incident near-infrared (NIR) light into heat. Human adenovirus serotype type-5 vectors encoding a firefly luciferase (fLuc) coding sequence driven by a heat-inducible promoter were incorporated into the hydrogels. Transmission electronic microscopic analysis revealed that the adenoviral vectors were associated to the fibrin fibers. In vitro experiments in which human cells were cultured with plasmonic hydrogels showed that the adenoviral vectors can diffuse from the hydrogels, transduce the cells, and stimulate heat-induced transgene expression upon NIR irradiation. The hydrogels were implanted in 4.2 mm drill hole defects generated in the humerus of male rabbits. Three days after implantation, the defects were NIR-irradiated. Six h later, the animals were euthanized and samples from the bone defect zone were processed for immunohistochemical analyses using a specific fLuc antibody. The results showed strong expression of fLuc in tissues surrounding the implants of NIR-irradiated rabbits, while non- irradiated animals exhibited negligible expression. We next aimed to use the temperature increase to induce the production of transgenic bone morphogenetic protein 6 (BMP-6), using safe gene switches that can provide tighter control of in vivo transgene expression than heat-inducible promoters. These switches are only activated by heat in the presence of rapamycin and maintain a high level of targeted transgene expression for several days after heat activation. Adenoviral vectors encoding the safe switches that control the expression of BMP-6 were incorporated to the composites. The resulting NIR-responsive hydrogels were implanted in the bone defects generated in rabbits and used as a platform to transduce host cells, generate local hyperthermia and stimulate BMP-6 production.Acknowledgements: This research was supported by grants RTI2018-095159-B-I00 and PID2021-126325OB-I00 (MCIN/AEI/10.13039/501100011033 and “ERDF A way of making Europe”), by grant P2022/BMD- 7406 (Regional Government of Madrid). M.A.L-J. is the recipient of predoctoral fellowship PRE2019-090430 (MCIN/AEI/10.13039/501100011033).

Lidocaine constant rate infusion improves the probability of survival in rabbits with gastrointestinal obstructions: 64 cases (2012-2021).

To determine the survival to discharge rate of rabbits with gastrointestinal obstructions treated with lidocaine constant rate infusion (CRI) and other factors associated with survival. Cases of gastrointestinal obstruction in rabbits (n = 56, including 64 events) that had presented to a veterinary teaching hospital from 2012 to 2021. This was a retrospective study in which data on rabbits with evidence of gastrointestinal obstruction were extracted from veterinary teaching hospital medical records over a 9-year period. Systemic lidocaine treatment, breed, sex, age, temperature at presentation, blood glucose at presentation, and time to discharge or death were evaluated with univariate and multivariate logistic regression to identify factors significantly associated with survival to hospital discharge in rabbits with gastrointestinal obstruction. Comparatively, 89.7% of rabbits treated with lidocaine CRI (n = 39) survived to hospital discharge, while only 56% of rabbits that were not treated with lidocaine CRI (25) survived. In the final multivariate analysis, 2 factors were associated with survival to discharge: rabbits treated with systemic lidocaine and male rabbits had increased odds of survival compared to those not treated with systemic lidocaine and female rabbits, respectively. Results demonstrated that rabbits with gastrointestinal obstruction and treated with a lidocaine CRI were more likely to survive compared to rabbits not treated with lidocaine CRI.

Biochemical Alterations in Reproductive and Hepatorenal Functions in Male Rabbits Supplemented with Margarine, Natural Ghee and Olive Oil

The current study investigated the impact of synthetic margarine, natural ghee and olive oil ‎on the biochemical parameters of male rabbits, focusing on reproductive hormones as free ‎testosterone, bioavailable testosterone, sex hormone binding globulin (SHBG) also body ‎weight gain, antioxidant markers, hepatic and kidney functions. Forty male New Zealand ‎rabbits were randomly distributed to four groups, each containing 10 rabbits. The control ‎group was supplemented with the basal diet, while the margarine group was received 10% ‎margarine, the ghee group was fed on 10% natural ghee of diet and the olive oil group ‎received diet with 10% olive oil. Results indicated that the administration of synthetic ‎margarine throughout the experiment significantly increased body weight gain, liver enzyme ‎‎(AST), and renal profile (urea) in comparison to other groups. Moreover, there was a ‎decrease in reproductive hormones as free and bioavailable testosterone, and antioxidant ‎enzyme activity (GPx) in Margarine group; meanwhile, these modified parameters were ‎enhanced in ghee group and olive oil group. This study concluded that olive oil and natural ‎ghee had a more beneficial health impact on fertility performance compared to synthetic ‎margarine.‎

Histological differences in cartilage layer growth at various tendon and ligament insertions in rabbits.

Objectives: Histological differences in cartilage layer growth in Achilles tendon (AT), quadriceps tendon (QT), patellar tendon (PT), and anterior cruciate ligament (ACL) insertion are unclear. Therefore, this study aimed to investigate the differences in cartilage layer growth in AT, QT, PT, and ACL insertions. Materials and Methods: Forty-eight male Japanese white rabbits were used. Six animals were euthanized at different stages (day 1 and 1, 2, 4, 6, 8, 12, and 24 weeks). Safranin O-stained glycosaminoglycan (GAG) production area, chondrocyte count, and insertion width were investigated. Results: A two-way analysis of variance (ANOVA) revealed a significant difference in the main effects of time and insertion for all parameters. In addition, the time × insertion interaction was significant. Multiple comparisons showed a significant difference between the ACL insertion and all other variables; however, the GAG production area was not significantly different for the QT, PT, and AT insertions. AT insertions were significantly different from all other groups; however, the number of chondrocytes and insertion width were not significantly different for ACL, QT, and PT insertions. Conclusion: Cartilage layer growth differed between the AT, QT, PT, and ACL insertions. The differences between the insertions may also be due to the differences in their structures, locations, and mechanical environments.

Evaluation of bone regeneration using human derived-gingival mesenchymal stem cells loaded on beta tricalcium phosphate and hyaluronic acid: an experimental study

Background Healing of critical-sized bone defects (CSDs) is a challenging problem in both clinical and research settings. Aim The present study aimed to assess the regenerative capacity of human gingival-derived mesenchymal stem cells (hGMSCs) loaded on beta-tricalcium phosphate scaffold (β-TCP) and hyaluronic acid (HA) gel in surgically created standardized CSDs in rabbit’s femurs. Materials and methods To achieve this aim, CSDs of 6 mm diameter each, were unilaterally created in femur of adult New Zeeland male white rabbits (n = 18). The rabbits were then divided randomly into three groups and received the following treatment modalities: group A (study group): six defects were treated with hGMSCs loaded on β-TCP scaffold combined with HA gel; group B (positive control group): six defects (n = 6 rabbits) were treated with β-TCP combined with HA gel; group C (negative control group): three defects were left without intervention. Two rabbits from groups A, B and one rabbit from group C were sacrificed at 6 weeks, femurs were dissected out to evaluate bone healing histologically and histomorphometrically. Results The findings of this study indicate that, hGMSCs exhibited fibroblast like morphology and expressed phenotypic MSCs markers (positive for cluster of differentiation CD105 and negative for CD34). Histologically, local application of hGMSCs loaded on β-TCP scaffold with HA gel showed enhanced pattern of bone regeneration as compared to the unloaded scaffold. Histomorphometrically, there was a statistically significant difference in the newly formed bone between the bony defects treated with hGMSCs and control groups. Conclusion GMSCs can be considered as a dependent source of MSCs with bone tissue regenerative capacity.

The effect of dietary eugenol nano-emulsion supplementation on growth performance, serum metabolites, redox homeostasis, immunity, and pro-inflammatory responses of growing rabbits under heat stress.

Heat stress (HS) is a main abiotic stress factor for the health and welfare of animals. Recently, the use of nano-emulsion essential oils exhibited a promising approach to mitigate the detrimental impacts of abiotic and biotic stresses, ultimately contributing to the global aim of sustainable livestock production. The current study was piloted to assess the impact of eugenol nano-emulsion (EUGN) supplementation on growth performance, serum metabolites, redox homeostasis, immune response, and pro-inflammatory reactions in growing rabbits exposed to HS. A total of 100 male weaning rabbits aged 35 days were divided into 4 treatments. Rabbits were fed the diet with EUGN at different concentrations: 0 (control group; EUGN0), 50 (EUGN50), 100 (EUGN100), and 150 (EUGN150) mg/kg diet for 8 weeks under summer conditions. Dietary EUGN levels significantly improved (p < 0.05) the body weight, body weight gain, carcass weights, and improved feed conversion ratio of rabbits. EUGN supplementation significantly increased Hb, platelets, and red blood cells , while the mean corpuscular hemoglobin and eosinophils were significantly decreased compared to the control one. Compared with EUGN0 stressed rabbits, all EUGN-experimental groups had a reduction in levels of total glycerides (p < 0.01), uric acid, total bilirubin, direct bilirubin, and gamma-glutamyl transpeptidase (p < 0.01). Total antioxidant capacity and glutathione peroxidase were significantly improved by EUGN treatment when compared to the control one (p < 0.01), while the EUGN100 exhibited the greatest levels of catalase. Lipid peroxidation (malondialdehyde) was significantly decreased in EUGN-treated groups. All pro-inflammatory cytokines serum interleukin 4, Interleukin 1β, and tumor necrosis factor alpha were considerably decreased after dietary EUGN supplementation (p < 0.05). The serum concentrations of immunoglobulins (IgG and IgM) were significantly improved in rabbits of the EUGN150 group. This study shows that EUGN can be used as a novel feed additive to enhance the growth performance, immune variables, and antioxidants, and reduce the inflammatory response of growing rabbits exposed to thermal stress.

Vocal Fold Submucosal Mesna Injection and Microflap Elevation in a Rabbit Model.

Mesna triggers chemical dissection in tissues by breaking down disulfide bonds and is used during surgical dissections in several areas. In this study, we aimed to investigate the effect of submucosal mesna infiltration on microflap elevation and the histopathological findings of its effects on the vocal fold lamina propria in a rabbit model. Eight adult male New Zealand white rabbits were used in the study. Each vocal fold was randomized, and 0.1 mL of mesna was injected into one-fold and 0.1 mL of saline to the contralateral fold. An incision was made on the epithelium and elevation was performed. The animals were sacrificed after two weeks, and the vocal folds were excised. Inflammatory response, fibrosis, and epithelial thickness were evaluated with hematoxylin eosin and Masson's Trichrome staining. Elevation time and histopathological features were compared between the two groups. The elevation time (20.9 ± 1.6 second) in the saline group was significantly higher (P < 0.05) than in the mesna group (15.0 ± 3.4 second). The inflammation (1.3 ± 0.5 vs. 1.1 ± 1.0, respectively) and fibrosis scores (1.0 ± 0.8 vs. 0.8 ± 0.7, respectively) did not differ significantly (P > 0.05 in both). Epithelial thickness (12.5 ± 4.7 vs. 10.3 ± 5.3, respectively) did not differ significantly (P ˃ 0.05) in the mesna and saline groups either. We determined that mesna facilitates the microflap elevation of the vocal folds in rabbits and does not damage the histological structure of vocal folds. This study encourages future studies to evaluate the use of mesna, now actively used across disciplines, in phonosurgery as well.

Liposomes versus microemulsions: Two novel nanosystems achieved an increased latanoprost hypotensive effect compared to traded medication

Aims/Purpose: The design of new topical ophthalmic nanosystems is linked to obtain non‐harmful carriers capable of increasing drug bioavailability and reduce the frequency of its instillations. Hypotensive actives such as latanoprost (L) are used to decrease intraocular pressure (IOP) in glaucoma patients. Two novel formulations, L‐loaded liposomes (LL) and L‐loaded microemulsions (LME), both including hyaluronic acid for its mucoadhesive properties were elaborated. The efficacy in reducing IOP of both formulations (48 h) was compared to a traded L‐ophthalmic solution (TM).Methods: LL were manufactured by the lipid film hydration method using synthetic phospholipids and cholesterol. LME were produced according to the self‐emulsification method by employing well‐tolerated oils and co‐solvents. Both LL and LME were characterized in terms of pH, osmolarity, size distribution, viscosity, and surface tension. Their hypotensive effect was evaluated up to 48 h in normotensive male albino New Zealand rabbits (n = 6, 12 eyes) using a tonometer following a single 25 μL topical administration and related to TM (n = 6). Draize test was performed before and 4 h after the instillation to establish LL, LME and TM tolerance.Results: Both LL and LME displayed proper physicochemical properties for the parameters evaluated. According to Draize test, both formulations resulted well‐tolerated without any sign of conjunctival hyperaemia, chemosis or discharge. Both LL and LME showed at least a 24‐h longer IOP reduction compared to TM, with the higher decrease at 3 h for LL and TM (24.02 ± 8.26% LL; 21.94 ± 10.14% TM) and 28 h for LME (30.40 ± 6.50%). Whilst at 24 h animals treated with TM (101.68 ± 5.27%) recuperated basal values, LL (91.08 ± 7.89%) and LME (80.14 ± 7.19%) rabbits still showed IOP decrease effect.Conclusions: Liposomes and microemulsions showed a longer hypotensive effect compared to traded medication, which makes them encouraging novel compliance‐friendly eye drops for glaucoma treatment.Acknowledgments: PID2020‐113281RB‐C21 funded by MCIN/AEI/10.13039/501100011033; 813440‐ORBITAL‐H2020‐MSCA‐ITN‐2018.

Flap of the sternocephalicus muscle in the repair of a partial defect in the trachea of a rabbit (Oryctolagus cuniculus).

The current study aimed at evaluating the repair of a partial defect of the trachea with a muscle flap, an advanced technique that employs combined suture patterns. Sixteen healthy male New Zealand white rabbits were used as an experimental model. A partial defect in the trachea within the ventral region of the fourth to eighth tracheal ring was created. Subsequently, repair was initiated with a flap of the sternocephalicus muscle. The animals were divided into four groups for postoperative evaluation using clinical, tracheoscopic, and histopathological analyses. Each group was separated according to the time of euthanasia, programmed at interval of seven (G7), 15 (G15), 30 (G30), and 60 days (G60). One animal from the G60 group died, whereas the other animals had good surgical recovery without serious changes in the breathing pattern. The major clinical signs observed were stridor and coughing. Tracheoscopy revealed secretions in the tracheal lumen, exuberant granulation, and stenosis. Histopathological analysis showed growth of the ciliary respiratory epithelium at the flap site 30 days after implantation. Partial repair showed satisfactory results owing to the anatomical location of the muscle, adequate vascular support, and structural and physiological maintenance without serious changes in the respiratory system.

The impact of acemannan, an extracted product from Aloe vera, on proliferation of dental pulp stem cells and healing of mandibular defects in rabbits.

Dental pulp stem cells (DPSCs) were shown to play an important role in regenerative medicine including reconstruction of various bone lesions. This study determined the impact of acemannan, an extracted product from Aloe vera, on in vitro proliferation of DPSCs and in vivo healing of mandibular defects in rabbits. DPSCs were isolated and characterized. The growth kinetics of cells exposed to acemannan (8 mg/mL) and Hank's balanced salt solution (HBSS) were compared in vitro. Fifteen male rabbits were divided into 3 groups. Five animals were left as control group without any therapeutic intervention. Five rabbits were considered as experimental group 1 and received 20 µL of a cell suspension containing 106 DPSCs in the bone defect. Another 5 rabbits were regarded as experimental group 2 and were injected in the bone defect with 20 µL of a cell suspension containing 106 DPSCs treated with acemannan for 24 h. After 60 days, the animals were assessed by radiography and histologically. The mesenchymal properties of DPSCs were confirmed. Population doubling time (PDT) of DPSCs treated with acemannan (29.8 h) was significantly shorter than cells were just exposed to HBSS (45.9 h). DPSCs together with acemannan could significantly accelerate the healing process and osteogenesis in mandibular defects. As DPSCS showed an increased proliferation when treated with acemannan and accelerated the healing process in mandibular defects, these findings can open a new avenue in dentistry regenerative medicine when remedies of bone defects are targeted.