Zealand White Rabbits Research Articles

Efficacy of ADIPOR1 and ADIPOR2 peptide-agonist AdipoRon in preventing contracture in a rabbit model of arthrofibrosis.

AdipoRon is an adiponectin receptor 1, 2 (ADIPOR1 and ADIPOR2) agonist with potential antifibrotic effects. Whether AdipoRon can mitigate joint stiffness in a rabbit model of arthrofibrosis is unknown. We examined the efficacy of intravenous (IV) AdipoRon at mitigating contracture in a rabbit model of knee arthrofibrosis. Fifty-six female New Zealand White rabbits were divided into three dosing groups: vehicle (dimethyl sulfoxide, DMSO), 2.5 mg/kg AdipoRon, and 5 mg/kg AdipoRon. AdipoRon, in DMSO, was administered IV preoperatively and for 5 days postoperatively (30 rabbits, Aim 1). AdipoRon was again dosed similarly after Kirschner wire (K-wire) removal at 8 weeks (26 rabbits; Aim 2). The primary outcome of joint passive extension angle (PEA,°) was measured at 8, 10, 12, 16, and 24 weeks following index surgery. At 24 weeks, rabbits were euthanized and limbs were harvested to measure posterior capsular stiffness (N cm/°). In Aim 1, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 16-week (p < 0.05). In Aim 2, the 5 mg/kg treated rabbits had a significant increase in PEA when compared to controls at 10-week (p < 0.05). In both aims, no significant differences were observed at later time points. Capsular stiffness was no different in any group. We are the first to report the efficacy of IV AdipoRon in a rabbit model of arthrofibrosis. We identified a significant dose-dependent decrease in joint PEA at early time points; however, no differences were observed between groups at later time points. Clinical Significance: The present investigation provided the first assessment of AdipoRon's efficacy in mitigating knee stiffness in the current gold standard rabbit model of arthrofibrosis. Results of this investigation provided further evidence as to the potential role of AdipoRon as a preventative for arthrofibrosis in large mammals.

A rhPDGF-BB/bovine type I collagen/β-TCP mixture for the treatment of critically sized non-union tibial defects: An in vivo study in rabbits.

Non-union during healing of bone fractures affects up to ~5% of patients worldwide. Given the success of recombinant human platelet-derived growth factor-B chain homodimer (rhPDGF-BB) in promoting angiogenesis and bone fusion in the hindfoot and ankle, rhPDGF-BB combined with bovine type I collagen/β-TCP matrix (AIBG) could serve as a viable alternative to autografts in the treatment of non-unions. Defects (~2 mm gaps) were surgically induced in tibiae of skeletally mature New Zealand white rabbits. Animals were allocated to one of four groups-(1) negative control (empty defect, healing for 8 weeks), (2 and 3) acute treatment with AIBG (healing for 4or 8weeks), and (4) chronic treatment with AIBG (injection 4 weeks post defect creation and then healing for 8 weeks). Bone formation was analyzed qualitatively and semi-quantitatively through histology. Samples were imaged using dual-energy X-ray absorptiometry and computed tomography for defect visualization and volumetric reconstruction, respectively. Delayed healing or non-healing was observed in the negative control group, whereas defects treated with AIBG in an acute setting yielded bone formation as early as 4 weeks with bone growth appearing discontinuous. At 8 weeks (acute setting), substantial remodeling was observed with higher degrees of bone organization characterized by appositional bone growth. The chronic healing, experimental, group yielded bone formation and remodeling, with no indication of non-union after treatment with AIBG. Furthermore, bone growth in the chronic healing group was accompanied by an increased presence of osteons, osteonal canals, and interstitial lamellae. Qualitatively and semiquantitatively, chronic application of AI facilitated complete bridging of the induced non-union defects, while untreated defects or defects treated acutely with AIBG demonstrated a lack of complete bridging at 8 weeks.

Effects of electro-mechanical uncouplers, hormonal stimulation and pacing rate on the stability and function of cultured rabbit myocardial slices

Introduction: Recent advances have enabled organotypic culture of beating human myocardial slices that are stable for weeks. However, human myocardial samples are rare, exhibit high variability and frequently originate from diseased hearts. Thus, there is a need to adapt long-term slice culture for animal myocardium. When applied to animal cardiac slices, studies in healthy or genetically modified myocardium will be possible. We present the culture of slices from rabbit hearts, which resemble the human heart in microstructure, electrophysiology and excitation-contraction coupling.Methods: Left ventricular myocardium from New Zealand White rabbits was cut using a vibratome and cultured in biomimetic chambers for up to 7 days (d). Electro-mechanical uncoupling agents 2,3-butanedione monoxime (BDM) and cytochalasin D (CytoD) were added during initiation of culture and effects on myocyte survival were quantified. We investigated pacing rates (0.5 Hz, 1 Hz, and 2 Hz) and hormonal supplements (cortisol, T3, catecholamines) at physiological plasma concentrations. T3 was buffered using BSA. Contractile force was recorded continuously. Glucose consumption and lactate production were measured. Whole-slice Ca2+ transients and action potentials were recorded. Effects of culture on microstructure were investigated with confocal microscopy and image analysis.Results: Protocols for human myocardial culture resulted in sustained contracture and myocyte death in rabbit slices within 24 h, which could be prevented by transient application of a combination of BDM and CytoD. Cortisol stabilized contraction amplitude and kinetics in culture. T3 and catecholaminergic stimulation did not further improve stability. T3 and higher pacing rates increased metabolic rate and lactate production. T3 stabilized the response to β-adrenergic stimulation over 7 d. Pacing rates above 1 Hz resulted in progredient decline in contraction force. Image analysis revealed no changes in volume fractions of cardiomyocytes or measures of fibrosis over 7 d. Ca2+ transient amplitudes and responsiveness to isoprenaline were comparable after 1 d and 7 d, while Ca2+ transient duration was prolonged after 7 d in culture.Conclusions: A workflow for rabbit myocardial culture has been established, preserving function for up to 7 d. This research underscores the importance of glucocorticoid signaling in maintaining tissue function and extending culture duration. Furthermore, BDM and CytoD appear to protect from tissue damage during the initiation phase of tissue culture.

Enhancing osteoblast proliferation and bone regeneration by poly (amino acid)/selenium-doped hydroxyapatite

Among various biomaterials employed for bone repair, composites with good biocompatibility and osteogenic ability had received increasing attention from biomedical applications. In this study, we doped selenium (Se) into hydroxyapatite (Se-HA) by the precipitation method, and prepared different amounts of Se-HA-loaded poly (amino acid)/Se-HA (PAA/Se-HA) composites (0, 10 wt%, 20 wt%, 30 wt%) by in-situ melting polycondensation. The physical and chemical properties of PAA/Se-HA composites were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and their mechanical properties. XRD and FT-IR results showed that PAA/Se-HA composites contained characteristic peaks of PAA and Se-HA with amide linkage and HA structures. DSC and TGA results specified the PAA/Se-HA30 composite crystallization, melting, and maximum weight loss temperatures at 203.33 °C, 162.54 °C, and 468.92 °C, respectively, which implied good thermal stability. SEM results showed that Se-HA was uniformly dispersed in PAA. The mechanical properties of PAA/Se-HA30 composites included bending, compressive, and yield strengths at 83.07 ± 0.57, 106.56 ± 0.46, and 99.17 ± 1.11 MPa, respectively. The cellular responses of PAA/Se-HA composites in vitro were studied using bone marrow mesenchymal stem cells (BMSCs) by cell counting kit-8 assay, and results showed that PAA/Se-HA30 composites significantly promoted the proliferation of BMSCs at the concentration of 2 mg ml−1. The alkaline phosphatase activity (ALP) and alizarin red staining results showed that the introduction of Se-HA into PAA enhanced ALP activity and formation of calcium nodule. Western blotting and Real-time polymerase chain reaction results showed that the introduction of Se-HA into PAA could promoted the expression of osteogenic-related proteins and mRNA (integrin-binding sialoprotein, osteopontin, runt-related transcription factor 2 and Osterix) in BMSCs. A muscle defect at the back and a bone defect at the femoral condyle of New Zealand white rabbits were introduced for evaluating the enhancement of bone regeneration of PAA and PAA/Se-HA30 composites. The implantation of muscle tissue revealed good biocompatibility of PAA and PAA/Se-HA30 composites. The implantation of bone defect showed that PAA/Se-HA30 composites enhanced bone formation at the defect site (8 weeks), exhibiting good bone conductivity. Therefore, the PAA-based composite was a promising candidate material for bone tissue regeneration.

Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BackgroundRotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.MethodsTwenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.ResultsAt 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.ConclusionOur study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Prenatal and postnatal development of New Zealand white rabbit (Oryctolagus cuniculus) teeth: histological and computed tomography aspects

AbstractThe study reveals a lack of histomorphogenesis in New Zealand white rabbit teeth. The teeth development was examined through sequential histological segments in 24 rabbits from prenatal ages (E19, E21, E23, E25, and E28), neonates (E30), and postnatal age (1 week and 2 weeks); (three animal specimens at each age stage). Rabbit teeth first appeared at 19 days of prenatal life (E19) as an ectodermal epithelial thickening on each side of the mouth opening. At E21, the bud of upper incisor tooth appeared as an epithelial bud, which composed of many condensed epithelium cells, was simply identified from the larger with less condensed vestibular lamina, and was surrounded by mesenchymal connective tissue while the lower incisor took the cap stage. At (E23), tooth regular construction is formed from enamel, dentine, and pulp cavity. Peg incisor appearance (supplementary and assistant incisors) is visible at the lingual surface of the upper major incisor. Teeth prenatal development went through successive stages like initiation, bud, cap, late bell, maturation, and crown stages. The first initiation phase of tooth formation was seen as ectodermal epithelial cell collection at (E19). Bud stage saw on upper incisor tooth, while in cap structure in lower incisor teeth at (E19). A cap-formed tooth is composed of the enamel organ and fundamentally dense mesenchymal tissue. Enamel organs are segmented into three distinct layers: the external tooth enamel epithelial, the internal tooth enamel epithelial, and finally the stellate reticular layer. The cement layer covered teeth all around on enamel on both the labial and lingual sides while not contacting the dentine on the lateral side, forming enamel space. Teeth develop consistently all through life; they have expanded enamel thickness; they are diphyodont teeth; they have two continuous dentitions; they are deciduous and perpetual, with long crown teeth and an open root.

Histologic characterization of spontaneous catecholamine-induced cardiomyopathy in laboratory New Zealand White rabbits.

Catecholamine-induced cardiomyopathy (CCM) is an entity associated with increased levels of catecholamines causing subendocardial and papillary muscle cardiomyocyte degeneration and necrosis. In 2020, 49 autopsies from early rabbit deaths in a colony used for medical device biocompatibility studies were submitted for microscopic examination. Of the 49 rabbits, 26 had histologic changes consistent with CCM. No common stressor for CCM was determined in affected rabbits. Animals were generally male, were 12-16-wk-old, and were found dead or had bloating, lethargy, and/or diarrhea. Those observed with clinical signs were euthanized and autopsied per the organization's standard operating procedures. Heart lesions consisted of various degrees of apical subendocardial myocardial degeneration and necrosis. Common non-cardiac lesions included pulmonary congestion and edema, hepatic congestion and centrilobular hepatocellular degeneration, and/or variable intestinal submucosal edema.

A New Method for Creating Impact-Induced Intra-Articular Fractures in a Rabbit Model Induces Severe Post-Traumatic Osteoarthritis.

The objective of this work was to develop a model of intra-articular fracture (IAF) in a rabbit and document the speed and severity of degenerative joint changes after fracture fixation. With Institutional Animal Care & Use Committee approval, impact-induced IAFs were created in the distal tibia of 16 New Zealand White rabbits. Fractures were fixed with a plate and screws. Pain and function were monitored at regular postoperative intervals with limb loading analysis. Twelve or 26 weeks after fracture, animals were euthanized for histological assessment of cartilage degeneration and micro-computed tomography analysis of bone histomorphometry. Eleven animals successfully completed the study. Maximum foot force in the fractured limb was 41% ± 21% lower than preoperative values ( P = 0.006) 12 weeks after fracture and remained 25% ± 13% lower ( P = 0.081) after 26 weeks. Cortical bone mineral density in micro-computed tomography images was 34% ± 13% lower 12 weeks after fracture ( P < 0.001) and remained (42% ± 8%) lower 26 weeks after fracture ( P < 0.001). Twelve weeks after fracture, Mankin scores of cartilage degeneration were significantly higher in the medial talus ( P = 0.007), lateral talus ( P < 0.001), medial tibia ( P = 0.017), and lateral tibia ( P = 0.002) of the fractured limb compared with the uninjured contralateral limb. Average Mankin scores in the talus increased from 12 to 26 weeks (5.9 ± 0.9 to 9.4 ± 0.4; P < 0.001 lateral; 5.4 ± 1.8 to 7.8 ± 2.0; P = 0.043 medial), indicating substantial and progressive joint degeneration. The ankle joint of the New Zealand White rabbit provides the smallest available model of impact-induced IAF that can be treated with clinically relevant techniques and replicates key features of healing and degeneration found in human patients.

Meat quality and sensory traits in rabbits fed with two different percentages of bovine colostrum

The nutritional, antimicrobial, and antioxidant properties of bovine colostrum (BC) have encouraged its use in animal nutrition as a functional food in recent years. Nonetheless, the potential implications of BC supplementation on meat quality remain to be thoroughly assessed. To address this, thirty-nine New Zealand White rabbits (n = 13/group) were fed different dietary regimens until slaughter.: commercial standard diet for the control group (C) and C with 2.5% and 5% w/w of BC for BC-2.5 and BC-5 groups, respectively. Rabbits were slaughtered at 91 days of age and meat quality, and sensory characteristics were evaluated at days 2 (48 h after slaughter), 5, and 10 of refrigerated storage at 4 °C.The addition of colostrum in the diet resulted in a reduction of the total viable count, albeit only at the highest concentration and at the final detection, whereas for Lactobacillus spp. and Pseudomonas spp., there was little or no effect. The colour coordinates showed no differences between the groups, but they varied over time according to diet. Some differences between groups emerged in the definition of sensory attributes but did not affect the overall liking and overall scores of individual descriptors. These results indicate that the use of colostrum in rabbit feeding does not significantly impart meat quality and sensory attributes, but the potential of this valuable by-product for the food industry needs further investigation.

High-resolution Magnetic Resonance Imaging can predict osteoarthritic progression after medial meniscus posterior root injury: randomized in vivo experimental study in a rabbit model.

ImportanceThe field of meniscal root preservation has undergone significant advancement over the past decades; however, the challenge remains to fully understand whether meniscal root repair can ultimately arrest or delay osteoarthritic changes. ObjectiveTo assess longitudinal changes in articular cartilage, subchondral bone, and progression to meniscal extrusion (ME) using high-resolution magnetic resonance imaging (MRI). MethodsMedial meniscus posterior root tear was surgically induced in 39 New Zealand White rabbits. Animals were randomly assigned into three experimental groups: partial meniscectomy after root tear (PM, n=13); root tear left in situ (CT, n=13); and transtibial root repair (RR, n=13). Contralateral limbs were used as healthy controls. High resolution 4.7 Tesla MRI of the knee joint was performed at baseline, after 2-, and 4-months of post-surgery. Cartilage thickness was calculated in medial and lateral compartments. In addition, the evaluation of ME, subchondral bone edema, and the healing potential after root repair were assessed. ResultsProgressive cartilage thinning, ME, and subchondral bone edema were evident in all 3 study groups after 4-months of follow-up. The mean cartilage thickness in the PM group was 0.53mm (± 0.050), 0.57mm (± 0.05) in the CT group, and 0.60mm (± 0.08) in the RR group. The PM group exhibited significantly higher cartilage loss when compared to the CT and RR groups (p<0.001). In addition, progressive ME and subchondral bone edema were associated with a more severe cartilage loss at the final follow-up. ConclusionMeniscal root repair did not halt but reduces the progression of osteoarthritis (OA). Degenerative changes worsened at a rapid rate in the PM group compared to the RR and CT groups. Early cartilage swelling, persistent subchondral edema, and progressive ME predicted more severe progression to knee OA in the CT and RR groups. Level Of EvidenceII

Dynamic flow for efficient partial decellularization of tracheal grafts: A preliminary rabbit study.

Bioengineered tracheal grafts are a potential solution for the repair of long-segment tracheal defects. A recent advancement is partially decellularized tracheal grafts (PDTGs) which enable regeneration of host epithelium and retain viable donor chondrocytes for hypothesized benefits to mechanical properties. We propose a novel and tunable 3D-printed bioreactor for creating large animal PDTG that brings this technology closer to the bedside. Conventional agitated immersion with surfactant and enzymatic activity was used to partially decellularize New Zealand white rabbit (Oryctolagus cuniculus) tracheal segments (n = 3). In parallel, tracheal segments (n = 3) were decellularized in the bioreactor with continuous extraluminal flow of medium and alternating intraluminal flow of surfactant and medium. Unprocessed tracheal segments (n = 3) were also collected as a control. The grafts were assessed using the H&E stain, tissue DNA content, live/dead assay, Masson's trichrome stain, and mechanical testing. Conventional processing required 10 h to achieve decellularization of the epithelium and submucosa with poor chondrocyte viability and mechanical strength. Using the bioreactor reduced processing time by 6 h and resulted in chondrocyte viability and mechanical strength similar to that of native trachea. Large animal PDTG created using our novel 3D printed bioreactor is a promising approach to efficiently produce tracheal grafts. The bioreactor offers flexibility and adjustability favorable to creating PDTG for clinical research and use. Future research includes optimizing flow conditions and transplantation to assess post-implant regeneration and mechanical properties. NA.

Economic analysis of banana peel and sweet potato vines in diets for rabbits.

This study aimed to evaluate the costs of using banana peel (BP) and sweet potato vine (SPV) in rabbit diets. BP and SPV were chosen to replace maize and alfalfa hay, because, in addition to the ingredients having similar nutritional characteristics, they are among the most expensive ingredients in rabbit diets. Data were obtained through a biological assay carried out in the Cuniculture Laboratory of the Universidade Federal de Santa Maria, Santa Maria, RS, Brazil. Fifty New Zealand white rabbits, weaned at 35days of age, were fed during the growth phase (35 to 84days) with increasing levels of BP and SPV, replacing maize and alfalfa hay (T0, T25, T50, T75 and T100% replacement). A diet containing 100% replacement (T100) had the lowest cost per kilogram, which was R$ 1.18/kg, while the controlled diet was 57% more expensive, costing R$ 2.08/kg. The total operating cost to produce a rabbit with control treatment was R$10.93/head and at T100, it was R$6.51/head. The animal income for a live rabbit was R$ 24.08 and R$ 23.95 in treatments T0 and T100, respectively. Regarding the gain margin per animal (GMA), in TO it was R$ 13.16 while in T100 it was R$ 17.44, therefore the GMA was 32.55% higher when using the T100 diet. In conclusion, it is more economical and feasible to feed rabbits with diets containing 100% BP and SPV, replacing maize and alfalfa hay.

Non-clinical toxicity and immunogenicity evaluation of a Plasmodium vivax malaria vaccine using Poly-ICLC (Hiltonol®) as adjuvant

Malaria caused byPlasmodium vivaxis a pressing public health problem in tropical and subtropical areas.However, little progress has been made toward developing a P. vivaxvaccine, with only three candidates being tested in clinical studies. We previously reported that one chimeric recombinant protein (PvCSP-All epitopes) containing the conserved C-terminus of the P. vivax Circumsporozoite Protein (PvCSP), the three variant repeat domains, and aToll-like receptor-3 agonist,Poly(I:C), as an adjuvant (polyinosinic-polycytidylic acid, a dsRNA analog mimicking viral RNA), elicits strong antibody-mediated immune responses in mice to each of the three allelic forms of PvCSP. In the present study, a pre-clinical safety evaluation was performed to identify potential local and systemic toxic effects of the PvCSP-All epitopes combined with the Poly-ICLC (Poly I:C plus poly-L-lysine, Hiltonol®) or Poly-ICLC when subcutaneously injected into C57BL/6 mice and New Zealand White Rabbits followed by a 21-day recovery period. Overall, all observations were considered non-adverse and were consistent with the expected inflammatory response and immune stimulation following vaccine administration. High levels of vaccine-induced specific antibodies were detected both in mice and rabbits. Furthermore, mice that received the vaccine formulation were protected after the challenge with Plasmodium berghei sporozoites expressing CSP repeats from P. vivax sporozoites (Pb/Pv-VK210). In conclusion, in these non-clinical models, repeated dose administrations of the PvCSP-All epitopes vaccine adjuvanted with a Poly-ICLC were immunogenic, safe, and well tolerated.

Dietary replacement of maggot meal for soybean meal: implication on performance indices, nutrient digestibility, nitrogen utilisation and carcass characteristics of grower rabbits.

A study was conducted to investigate the effect of replacing soybean meal (SBM) with maggot meal (MM) in growing rabbits' diets on their performance, nutrient digestibility, and carcass characteristics. In the 56 days feeding trials, sixty unsexed mixed breeds (New Zealand White x California) rabbits were allotted on a weight equalization basis into five dietary treatments where a standard corn-soybean meal based diet (0% of maggot meal) (MM0 diet) served as the while other diets had soybean meal replaced with MM at graded levels of 25, 50, 75 and 100% to give MM25, MM50, MM75, and MM100 diets respectively. Each treatment comprises of four replicates having three rabbits each (12 rabbits per treatment). Growth performance parameters were monitored and recorded weekly, carcass and organ weights evaluation was conducted on day 56. Nutrient digestibility commenced on the 56th day and lasted for 6 days. Feed and water were offered to the rabbits ad-libitum throughout the experimental period. All the performance parameters were significantly (P < 0.05) affected by MM inclusion in the diet of rabbits. Rabbits fed MM100 diet had the highest (P < 0.05) final weight (FW), total weight gain(TWG), and the best feed conversion ratio (FCR). The feed cost reduced (P < 0.05) with inclusion of MM in rabbit's diet. Feed cost per kg live weight (FC/LW) (1110.79 ₦/kg) and feed cost per kg weight gain (FC/WG) (1110.62 ₦/kg) was lowest (P < 0.05) for rabbits fed MM100 diet. Crude protein digestibility (CPD) (74.05%) was highest (P < 0.05) for rabbits fed the MM100 diet. The feeding of MM75 and MM100 diets to rabbits resulted in increased (P < 0.05) dry matter digestibility (DMD) (68.22 and 69.34%), nitrogen free extract digestibility (NFED) (65.52 and 65.22%) and neutral detergent fibre digestibility (NDFD) (70.05 and 69.58%). The highest (P < 0.05) nitrogen retained (NR) (2.10g/d) occurred in rabbits fed the MM100 diet. The dressing percentage (DP) (71.01%) increased (P < 0.05) for rabbits fed the MM100 diet. The weight of forelimbs (10.48 and 10.45%) and hind limbs (17.42 and 18.07%) were highest (P < 0.05) for rabbits fed MM50 and MM100 diets respectively. Total gastrointestinal tract (GIT) and liver weight were highest (P < 0.05)for rabbits fed MM0 and MM100 diets respectively. It was concluded that MM can conveniently replace SBM in the diets of rabbits up to 100% for improved growth performance and increased nutrient digestibility. In addition, it can enhance DP and increase the carcass yield of rabbits.

Effect of Transarterial Chemotherapy on the Structure and Function of Gut Microbiota in New Zealand White Rabbits

The gut microbiota (GM) are closely related to hepatocellular carcinoma (HCC) occurrence and development. Furthermore, patients with HCC who have received transcatheter arterial chemoembolization (TACE) treatment often experience adverse gastrointestinal reactions, which may be related to changes in the GM caused by the chemotherapeutic drugs used in TACE. Therefore, we conducted animal experiments to investigate these changes. We analyzed changes in the GM of New Zealand white rabbits treated with hepatic arterial chemotherapy by measuring the levels of serological and colonic tissue markers. Simultaneously, we evaluated the correlation between the GM and these markers to explore the mechanism by which chemotherapy affects the GM. Following transarterial chemotherapy with epirubicin, the Firmicutes abundance decreased, whereas that of Proteobacteria increased. The relative abundance of beneficial bacteria, such as Muribaculaceae, Enterococcus, Ruminococcus, and Clostridia, decreased in the experimental group compared with those in the control group. However, the relative abundance of harmful bacteria, such as Bacteroides and Escherichia (Shigella), was higher in the experimental group than in the control group. Following chemotherapy, the GM of rabbits showed a dynamic change over time, first aggravating and then subsiding. The changes were most notable on the fourth day after surgery and recovered slightly on the seventh day. The changes in the host’s GM before and after arterial chemotherapy are evident. Hepatic arterial chemotherapy induces dysbiosis of the intestinal microbiota, disrupts intestinal barrier function, damages the integrity of the intestinal mucosa, increases intestinal permeability, facilitates excessive passage of harmful substances through the gut–liver axis communication between the liver and intestine, and triggers activation of inflammatory pathways such as LPS-TLR-4-pSTAT3, ultimately leading to an inflammatory response. This study provides a theoretical basis for combining TACE with targeted GM intervention to treat HCC and reduce adverse gastrointestinal reactions.

Development of A New Scoring System in Higher Animals for Testing Cognitive Function in the Newborn Period: Effect of Prenatal Hypoxia-Ischemia.

Introduction Enhanced models for assessing cognitive function in the neonatal period are imperative in higher animals. Postnatal motor deficits, characteristic of cerebral palsy, emerge in newborn kits within our prenatal-rabbit model of hypoxia-ischemia (HI). In humans, prenatal HI leads to intellectual disability and cerebral palsy. In a study examining cognitive function in newborn rabbits, we explored several questions. Is there a distinction between conditioned and unconditioned kits? Can the kits discern the human face or the lab coat? Do motorically-normal kits, born after prenatal HI, exhibit cognitive deficits? Methods The conditioning protocol was randomly assigned to kits from each litter. For conditioning, the same human, wearing a lab coat, fed the rabbit kits for 9 days before the cognitive test. The 6-arm radial maze was chosen for its simplicity and ease of use. Normally appearing kits, born after uterine ischemia at 79% or 92% term in New Zealand White rabbits, were compared to Naïve kits. On postpartum day 22/23 or 29/30, the 6-arm maze helped determine if the kits recognized the original feeder from bystander (Test-1) or the lab coat on bystander (Test-2). The use of masks of feeder/bystander (Test-3) assessed confounding cues. A weighted score was devised to address variability in entry to maze arms, time, and repeated-trial learning. Results In conditioned kits, both Naïve and HI kits exhibited a significant preference for the face of the feeder, but not the lab coat. Cognitive deficits were minimal in normal-appearing HI kits. Conclusion The weighted score system was amenable to statistical manipulation.

Growth performance and carcass characteristics of rabbits fed concentrate diets containing graded levels of Brassica oleracea outer leaves and Musa paradisiaca leaves

Ninety-six (96) 8-wk-old “mixed breed” of New Zealand white, California white and chinchilla rabbits were used to determine the growth performance, carcass and organ percentages of rabbits fed concentrate diets containing graded levels of Brassica oleracea outer leaves and Musa paradisiaca leaves. The rabbits were assigned to two groups of 48. Those in group 1 were allotted to four dietary treatments with concentrate diets containing 0, 10, 20 and 30% inclusion levels of B. oleracea outer leaves for one week and 12-wk adaptation and testing periods, respectively, for growth performance evaluation. Similar treatment and design were adopted for group 2 rabbits using graded levels of M. paradisiaca leaves. Six rabbits were randomly selected from each treatment group for slaughter at the end of the testing period for carcass and internal organ characteristics evaluation. There were no dietary effects on the parameters of rabbits fed graded levels of B. oleracea outer leaves except for M. paradisiaca, where the control diet had the lowest feed intake and the least (P&lt;0.05) feed conversion ratio comparable to 30% inclusion level and final body weight, which was the highest (P&lt;0.05) for rabbits fed diets containing 10 and 20% inclusion levels of M. paradisiaca leaves. The cost of feed was highest for the control diets, and reduced with increasing inclusion levels of the leaves in the diets. None of the rabbits died during the experimental period. The findings suggest that rabbits can be fed concentrate diets containing B. oleracea outer leaves and M. paradisiaca leaves up to 30% inclusion level for good growth performance and high carcass characteristics at a lower production cost than concentrate diets, while maintaining good health.

Investigation of Two New Grafting Techniques for Dorsal Augmentation Rhinoplasty: An Experimental Study with New Zealand White Rabbits.

Cartilage is an important source in supporting the structure of the nose for dorsal augmentation rhinoplasty. However, it is known that its viability is not always on the ideal level. Various wrapping materials are used to increase the strength of cartilage. Donor site morbidity, which develops following the harvesting of both cartilage and fascia as one such cover material, has attracted interest in recent years. In this study, we aimed to investigate the potential of dermis and tendon autografts as alternatives to fascia and cartilage. The sample of the study included 16 New Zealand white rabbits. The right auricular cartilage of all rabbits was amputated, and it was transformed into diced cartilage autografts. The dermis autografts from the right gluteal areas of the rabbits were deepithelialized, and lumbosacral fascia autografts were harvested from the same incision. Additionally, the Achilles tendon of each rabbit was harvested and transformed into diced tendon autografts. Four different autografts were embedded under the skin of each rabbit from 4 different pouches opened in the back of the rabbit. These autografts included diced cartilage alone (Intervention 1), fascia-wrapped cartilage (Intervention 2), dermis-wrapped cartilage (Intervention 3) and fascia-wrapped tendon (Intervention 4) autografts. Intervention 1 had the most irregular appearance, the outcomes in Intervention 4 were volumetrically smaller and softer. Connective tissue formed between the diced pieces in all interventions, and it was observed that the dermis and fascia had a capsule-like appearance, and their viability was preserved. The differences between the initial and final measurements of the volumes of interventions 1, 2 and 3 were statistically significant (p<0.05). There was no significant difference between the initial and final volumetric measurements of intervention 4 (p>0.05). More peripheral proliferation was observed in the interventions of fascia-wrapped and dermis-wrapped diced cartilage compared to the other interventions. The intervention including fascia-wrapped diced tendon grafts had displayed more fibrosis, fragmentation and collagen fibers, while it showed a lower amount of elastic fiber. There were no significant differences among the intervention in terms of other histological parameters. Tendon autografts may be a good option for dorsal augmentation rhinoplasty as they are easily harvested and have minimal donor site morbidity. Dermis autograft usage is more advantageous than fascia usage in terms of accessibility and convenience. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Design, Manufacture, and Characterization of a Critical-Sized Gradient Porosity Dual-Material Tibial Defect Scaffold

This study proposed a composite tibia defect scaffold with radial gradient porosity, utilizing finite element analysis to assess stress in the tibial region with significant critical-sized defects. Simulations for scaffolds with different porosities were conducted, designing an optimal tibia defect scaffold with radial gradient porosity for repairing and replacing critical bone defects. Radial gradient porosity scaffolds resulted in a more uniform stress distribution, reducing titanium alloy stiffness and alleviating stress shielding effects. The scaffold was manufactured using selective laser melting (SLM) technology with stress relief annealing to simplify porous structure fabrication. The study used New Zealand white rabbits’ tibia defect sites as simulation parameters, reconstructing the 3D model and implanting the composite scaffold. Finite element analysis in ANSYS-Workbench simulated forces under high-activity conditions, analyzing stress distribution and strain. In the simulation, the titanium alloy scaffold bore a maximum stress of 122.8626 MPa, while the centrally encapsulated HAp material delivered 27.92 MPa. The design demonstrated superior structural strength, thereby reducing stress concentration. The scaffold was manufactured using SLM, and the uniform design method was used to determine a collection of optimum annealing parameters. Nanoindentation and compression tests were used to determine the influence of annealing on the elastic modulus, hardness, and strain energy of the scaffold.

Growth performance, plasma metabolites, meat quality, and meat and lipid health indices of New Zealand White rabbits as affected by dietary dried tomato pomace powder supplementation during the summer season.

One hundred and twenty New Zealand White rabbits (NZW) (5-week-old; 735.27 ± 27.23 g) were kept in an open-sided house during the summer season. The experiment aims to evaluate the impacts of dried tomato pomace powder (DTPP) supplementation on rabbits' performance, blood metabolites, carcass traits, meat quality, and lipid and health indices of NZW rabbits during 5-13 weeks of age. The four treatments were a standard rabbit feed (control) and the control diet supplemented with 0.5, 1.0, and 1.5% DTPP, respectively. Rabbits fed a diet containing 1.5% DTPP showed the highest growth rate through weeks 9-13 of age despite having the lowest feed intake spanning 5-13 weeks. The best feed conversion ratio (FCR) was recorded in rabbits fed with 1.5% DTPP-supplemented diet for 5-13 weeks. Diets supplemented with 0.5 or 1.0% DTPP enhanced markedly dressing %, total edible flesh, saturated (SFAs), monounsaturated (MUFAs), and polyunsaturated fatty acid (PUFAs) contents, as well as the ∑n - 6/∑n - 3 ratio and the total n - 6 of meat. Dietary supplementation with DTPP decreased kidney, abdominal, and back fat. Diets supplemented with DTTP decreased total cholesterol, triglycerides, and very low-density lipoprotein (vLDL) concentrations. The greatest levels of linoleic acid, arachidonic and water-holding capacity in meat were observed in rabbits fed 1.5% DTPP-supplemented diets. Diets containing 1 and 1.5% DTPP improved meats' atherogenic and thrombogenic indices, meat lipid quality desired fatty acids/undesired fatty acids ratio, and meat health index. Conclusively, DTPP up to 1.5% maintained the growth performance of rabbits, boosted meat quality through increasing vitamin E, reduced fat deposition, modified fatty acid composition, and improved atherogenic, thrombogenic, and hypocholesterolemic indices of rabbit meat.