Zealand Rabbits Research Articles

Experimental Study for the Evaluation of Titanium Disc Decontamination and Osseointegration in the Rabbit Tibia Model

Peri-implantitis is an inflammatory lesion leading to bone destruction resulting from bacterial infection and biofilm formation. Treatments of peri-implantitis aim at bacterial controls and decontamination to promote re-osseointegration. The present study aimed to assess the decontamination of biofilm and the osseointegration of titanium discs in a rabbit tibia model. Discs were immersed in culture medium inoculated with Staphylococcus aureus and incubated at 37 °C for 24 h and allocated to different treatments (n = five per group). The decontamination methods were an air-polishing system, 0.12% chlorhexidine rinse, and Er:Yag laser treatments. Each disc from the experimental groups was observed using scanning electron micrography. The rest of the discs were then implanted in four male New Zealand rabbits. Histological and radiographic evaluations were performed. For the quantification of bone density in radiographic data, the fractal dimension (FD) and mean grayscale value (GV) were measured. The Kruskal–Wallis test was used to compare bone density (p < 0.05). Statistically significant differences in FD were observed between the air-polishing treatment with chlorhexidine rinse and the air-polishing treatment with chlorhexidine rinse and Er:Yag laser treatment compared to the contaminated group (p < 0.05). Also, there were statistically significant differences in the results obtained for the group undergoing air-polishing treatment with chlorhexidine rinse and Er:Yag laser treatment compared to the contaminated group (p < 0.05). The decontamination method using air polishing treatment, chlorhexidine rinse, and Er:Yag treatment showed favorable osseointegration with good bone quality.

Assessment of degradability and endothelialization of modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluders over time in vivo

ObjectiveTo evaluate the fiber-degradation and endothelialization of a modified poly L-lactic acid (PLLA) atrial septal defect (ASD) occluder for a long time in vivo.MethodsA total of 57 New Zealand rabbits were selected to establish the vasculature implantation model, which would be used to characterize the mechanical properties and pathological reaction of PLLA filaments (a raw polymer of ASD occluder). In total, 27 Experimental piglets were used to create the ASD model for the catheter implantation of PLLA ASD occluders. Then, X-ray imaging, transthoracic echocardiography, histopathology, and scanning electron microscope (SEM) were performed in the experimental animals at 3, 6, 12, and 24 months after implantation.ResultsIn the rabbit models, the fibrocystic grade was 0 and the inflammatory response was grade 2 at 6 months after vasculature implantation of the PLLA filaments. The mass loss of PLLA filaments increased appreciably with the increasing duration of implantation, but their mechanical strength was decreased without broken. In the porcine models, the cardiac gross anatomy showed that all PLLA ASD occluders were stable in the interatrial septum without any vegetation or thrombus formation. At 24 months, the occluders had been embedded into endogenous host tissue nearly. Pathological observations suggested that the occluders degraded gradually without complications at different periods. SEM showed that the occluders were endothelialized completely and essentially became an integral part of the body over time.ConclusionIn the animal model, the modified PLLA ASD occluders exhibited good degradability and endothelialization in this long-term follow-up study.

EFFECTS OF MONDIA WHITEI ON THE TEAR FUNCTION OF RABBIT EYES

<p><strong>Background:</strong> Dry eye is a serious problem affecting up to 20% of the world’s population. <em>Mondia whitei</em>’s rich androgenic properties create an interest in research focused on its efficacy as an alternative and complementary therapy for the treatment and control of the symptoms of dry eye-related diseases associated with androgen deficiency. <strong>Aim: </strong>This study aimed to investigate the effect of <em>M. whitei</em> on the quality and quantity of tears in rabbit eyes.<strong> Setting: </strong>This study was carried out at the animal house at Masinde Muliro University of Science and Technology, Kakamega, Kenya. <strong>Materials and methods:</strong> The study adopted an experimental study design with 16 New Zealand rabbits. A simple random sampling technique was used to place the rabbits into 4 groups, each group with 4 rabbits. They were tested for tear function to establish a baseline before administration of Benzalkonium Chloride (BAC) (to induce dry eye) and <em>M. whitei</em> extract. Schirmer’s test and fluorescein staining were conducted to observe the tear quantity and quality over a period of 6 days after treatment. The data collected was then cleaned and analyzed. <strong>Results:</strong> The researchers found that the average mean during baseline tear quantity measurement for the groups was 26.5mm, during instilling of BAC the mean dropped to 24.0mm and when <em>M. whitei</em> was administered the mean rose to 27.94mm, indicating that <em>M. whitei</em> greatly improved tear quantity. During baseline tear quality assessment, the average mean for the groups was 0.00 which dropped to 0.94 showing mild staining and when <em>M. whitei</em> was administered dropped further to 1.67 indicating that <em>M. whitei</em> did not improve the tear quality. <strong>Conclusion and Recommendations:</strong> The researchers recommended that more research be done on <em>M. whitei </em>with fewer limitations such as time, to ascertain its effectiveness on tear quality and quantity.</p><p> </p><p><strong> Article visualizations:</strong></p><p><img src="/-counters-/soc/0065/a.php" alt="Hit counter" /></p>

Reinforcement of colon anastomosis healing with leukocyte platelet-rich fibrin in rabbit model

AimThis study investigated the regenerative efficacy of leukocyte platelet-rich fibrin (L-PRF) on colon anastomotic healing in rabbits. Main methodsThirty-six healthy male white New Zealand rabbits were subjected to complete transactions of the ascending colon. The rabbits were equally divided into two groups: the control group, where the transected colon ends were anastomosed by a simple interrupted suture pattern, and the L-PRF-treated group, in which L-PRF was wrapped entirely around the anastomotic line. The postoperative acute pain scale was assessed using the Bristol Rabbit Pain Scale before surgery and at each four-hour interval post-operatively. After euthanizing the rabbits, the adhesion degree score, anastomotic bursting pressure, and stenosis degree of the anastomotic colon were assessed, and histopathological examination at the 7th, 14th, and 28th days postoperatively. Key findingsRabbits in both groups showed a significant increase in pain scores compared to baseline. Postoperatively, the L-PRF group exhibited significantly lower pain scores, adhesion scores, and stenosis degrees than the control group. However, the anastomotic bursting pressure was significantly higher in the L-PRF group. Re-epithelialization, polymorphonuclear neutrophil infiltration, granulation tissue formation, and collagen deposition scores were improved considerably in the L-PRF group compared to the control group. Immunostaining of growth factor expression was significantly lower in the control than in the L-PRF group. SignificanceThe L-PRF can augment collagen deposition, re-epithelialize the mucosa, promote angiogenesis, reduce adhesions, and diminish the stenosis degree scores. Therefore, it can be considered a promising aid in healing bowel anastomoses.

Magnetic properties of Al3+ doped Fe3O4 by solid-solid reaction and biological applications of GQDs grafted MNPs

2.79 % Al3+ doped Fe3O4 magnetic nanoparticles (Al-Fe3O4 MNPs) was prepared by a solid–solid reaction between aluminum formic acid hydrazide and as-prepared Fe3O4 magnetic nanoparticles. The obtained Al-Fe3O4 MNPs were strongly ferromagnetic, and their greatest saturation magnetization value was 82.3 electromagnetic units per gram (emu/g). The Al-Fe3O4 MNPs were subsequently coated with SiO2. High-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), Mössbauer spectroscopy, and vibrating-sample magnetometry (VSM) were used to characterize the morphology, structure, magnetic properties, and doping mechanism of the doped magnetic particles, respectively. Then graphene quantum dot (GQD) is loaded on the surface of aminated Al-Fe3O4@SiO2 (AFS) MNPs by a covalent connection, and Al-Fe3O4@SiO2-GQDs (AFSG) MNPs. Furthermore, AFSG MNPs were labeled with the metastable nuclear isomer of technetium-99 (99mTc) and their in vivo targeting performance was investigated. The AFSG-99mTc MNPs demonstrated a relatively strong magnetic response in a pulsed magnetic gradient field. The data obtained from the control and experimental groups indicated that the ability to uptake radioactivity of the livers of New Zealand rabbits via the magnetic targeted intervention was 3.69 times higher than that without the magnetic targeted intervention.

Bioequivalence Evaluation of Topical Metronidazole Products Using Dermal Microdialysis in New Zealand Rabbits.

Comparative assessment of cutaneous pharmacokinetics (cPK) by dermal microdialysis (dMD) appears to be suitable to evaluate the bioequivalence (BE) of topical dermatological drug products applied to the skin (TDDPs). Although dMD studies in the literature have reported inconclusive BE assessments, we have addressed several methodological deficiencies to improve dMD's capability to assess BE between reference (R) and approved generic (referred to as test (T)) gel and cream products of metronidazole (MTZ). The 90% confidence interval (CI) of the geometric mean ratios for the Ln(AUC0-24) and Ln(Cmax) endpoints was centered within the BE limits of 80-125%. The CIs extended outside this range as the proof-of-principle study was not statistically powered to demonstrate BE (N = 7 rabbits). A power analysis suggests that, with the variability observed in this study, 21 rabbits for the cream and 11 rabbits for the gel would be sufficient to support an evaluation of BE with the 2 probe replicates we used, and only 10 and 5 rabbits would be sufficient to power the study for the cream and gel, respectively, if 4 probe replicates are used for each treatment per rabbit. These results indicate that dMD when properly controlling variables can be used to support BE assessments for TDDPs.

Polymeric nanocomposite hydrogel scaffold for jawbone regeneration: The role of rosuvastatin calcium-loaded silica nanoparticles

Bones are subject to different types of damages ranging from simple fatigue to profound defects. In serious cases, the endogenous healing mechanism is not capable of healing the damage or restoring the normal structure and function of the bony tissue. The aim of this research was to achieve a sustained delivery of rosuvastatin and assess its efficacy in healing bone tissue damage. Rosuvastatin was entrapped into silica nanoparticles and the system was loaded into an alginate hydrogel to be implanted in the damaged tissue. Silica nanoparticles were formulated based on a modified Stöber technique and alginate hydrogel was prepared via sprinkling alginate onto silica nanoparticle dispersion followed by addition of CaCl2 to promote crosslinking and hydrogel rigidification. The selected nanoparticle formulation possessed high % drug content (100.22±0.67%), the smallest particle size (221.00±7.30 nm) and a sustained drug release up to 4 weeks (98.72±0.52%). The fabricated hydrogel exhibited a further delay in drug release (81.52±4.81% after 4 weeks). FT-IR indicated the silica nanoparticle formation and hydrogel crosslinking. SEM visualized the porous and dense surface of hydrogel. In-vivo testing on induced bone defects in New Zealand rabbits revealed the enhanced rate of new bone tissue formation, its homogeneity in color as well as similarity in structure to the original tissue.

Deep learning for fast denoising filtering in ultrasound localization microscopy

Objective. Addition of a denoising filter step in ultrasound localization microscopy (ULM) has been shown to effectively reduce the error localizations of microbubbles (MBs) and achieve resolution improvement for super-resolution ultrasound (SR-US) imaging. However, previous image-denoising methods (e.g. block-matching 3D, BM3D) requires long data processing times, making ULM only able to be processed offline. This work introduces a new way to reduce data processing time through deep learning. Approach. In this study, we propose deep learning (DL) denoising based on contrastive semi-supervised network (CS-Net). The neural network is mainly trained with simulated MBs data to extract MB signals from noise. And the performances of CS-Net denoising are evaluated in both in vitro flow phantom experiment and in vivo experiment of New Zealand rabbit tumor. Main results. For in vitro flow phantom experiment, the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of single microbubble image are 26.91 dB and 4.01 dB, repectively. For in vivo animal experiment , the SNR and CNR were 12.29 dB and 6.06 dB. In addition, single microvessel of 24 μm and two microvessels separated by 46 μm could be clearly displayed. Most importantly,, the CS-Net denoising speeds for in vitro and in vivo experiments were 0.041 s frame−1 and 0.062 s frame−1, respectively. Significance. DL denoising based on CS-Net can improve the resolution of SR-US as well as reducing denoising time, thereby making further contributions to the clinical real-time imaging of ULM.

Comparative Regenerative Effects of Allogeneic Bone Marrow and Patellar Ligament Fat Pad Mesenchymal Stem Cells on Experimental Superficial Digital Flexor Tendonitis in New Zealand Rabbits

Background: Cell therapy is applied in tendonitis to speed the healing process of tendon tissue and restore its functional properties. Almost all types of stem cells can differentiate from the recipient cells after transplantation. Objectives: The main goal of this study is to compare the effects of two sources of mesenchymal stem cells on tendon regeneration. Methods: This study randomly divided 32 New Zealand rabbits into 4 groups. The bacterial collagenase was induced at the superficial digital flexor tendon (SDFT) of all rabbits, and the treatment was performed 48 hours after collagenase induction. Group 1 was treated with allogeneic bone marrow mesenchymal stem cells (BMMSCs). Group 2 was treated with adipose-derived stem cells (ADSCs) from the patellar ligament fat pad. Group 3 (sham group) was treated with 0.9% normal saline, and group 4 (control group) was left with no treatment. All rabbits were euthanized 2 and 4 weeks after surgery, and tendon samples were harvested. The histopathology was assessed by hematoxylin-eosin, Masson’s trichrome, and Vangieson’s dye, and tendon structure, fiber arrangement, cell nuclei, tissue inflammation, vascularity (angiogenesis), and density were surveyed. Results: The tendon healing process in the BMMSC and ADSC groups revealed better regeneration than the control and sham groups (P≤0.05). Significant changes (P≤0.05) in some microscopic parameters were seen by comparing the BMMSC and ADSC groups. Conclusion: According to the present study, the injection of mesenchymal stem cells (BMMSCs or ADSCs) showed beneficial results in tendon tissue healing. Furthermore, ADSCs showed better regeneration of the injured tendon tissue than BMMSCs.

Vascular effects of continuous hyperbaric oxygen exposure: experimental outlook.

Hyperbaric oxygen (HBO) treatment aims to restore tissue oxygenation by inhaling 100% oxygen in pressure rooms. Although beneficial effects have been reported with regard to re-oxygenated ischemic tissues, conflicting findings have been presented concerning the paradoxical tissue response following reperfusion and/or the different responses of non-ischemic normal tissues to increased oxygen exposure. The present study sought to experimentally investigate the impact of continuous HBO treatments on normal aortic tissue. New Zealand rabbits were placed in pressure rooms for 90 minutes per day under 2.5 atmospheric pressure and exposed to HBO for 28 days. Normal structural histology was obtained in the control group. Foam cells were detected in the aortic intimae, thickening and undulation were visualized in the endothelium, and localized separations were observed in the tunica media in the study group compared with the control group. Moreover, salient vasa vasorum was detected in the study group via histopathology. These findings suggest that continuous HBO exposures disrupt the normal vascular structure of a healthy aorta.

Far-infrared treatment of experimental sinusitis in rabbits: a pilot study.

Thermal therapy has existed for thousands of years and dates back to ancient civilizations such as the Finns, Romans, ancient Chinese, American Indians, and Egyptians. Sun therapy is a form of natural Far Infrared Rays (FIR) thermal therapy. Far infrared rays are invisible rays with the longest wavelength of natural sunlight. However, sunbathing should only be done in moderation, as sunlight contains ultraviolet rays that can burn and damage the skin. More than 30 million people in Asia, Europe, and Australia receive Far Infrared Therapy with FIR lamps. They emit 2-25-micron wavebands. We aimed to investigate whether FIR therapy that uses a similar waveband improves sinusitis symptoms. This study was conducted on 10 New Zealand rabbits of both sexes, 7-8 months old, with an average weight of 1.8-2.4 kg. They were divided into four study groups. Sinusitis was induced in rabbits by blocking the sinus ostium, whereas some were left as control. Far infrared treatment with an infra-sin device was given with or without antibiotics. Mucosal samples were evaluated microscopically regarding epithelial eruption, epithelial vacuolization, interstitial edema, vascular congestion, leukocyte infiltration, and mucosal thickening. We found clinical and histopathological improvements in rabbits with sinusitis on the right side of the nose, to which we applied FIR treatment with the device Infra-Sin. Our findings in this animal study led us to conclude that it would be beneficial to study the effects of FIR treatment on people with allergic rhinitis and sinusitis and to identify the optimal dosing, treatment duration, and intensity. To add to our findings, looking into whether FIR therapy can be used as an alternative to antibiotic treatment for human sinusitis is essential.

Surface-Modified Nano-Hydroxyapatite Uniformly Dispersed on High-Porous GelMA Scaffold Surfaces for Enhanced Osteochondral Regeneration.

This study aims to investigate the impact of enhancing subchondral bone repair on the efficacy of articular cartilage restoration, thereby achieving improved osteochondral regeneration outcomes. In this study, we modified the surface of nano-hydroxyapatite (n-HAp) through alkylation reactions to prepare n-HApMA. Characterization techniques, including X-ray diffraction, infrared spectroscopy scanning, thermogravimetric analysis, particle size analysis, and electron microscopy, were employed to analyze n-HApMA. Bioinks were prepared using n-HApMA, high porosity GelMA hydrogel, and adipose tissue derived stromal cells (ADSCs). The rheological properties of the bioinks during photocuring were investigated using a rheometer. Based on these bioinks, a biphasic scaffold was constructed. The viability of cells within the scaffold was observed using live-dead cell staining, while the internal morphology was examined using scanning electron microscopy. The stiffness of the scaffold was evaluated through compression testing. Scaffolds were implanted into the osteochondral defects of New Zealand rabbit knees, and microCT was utilized to observe the subchondral bone repair. Hematoxylin and eosin (H&E) staining, Masson's trichrome staining, and Safranin O/Fast Green staining were performed to assess the regeneration of subchondral bone and cartilage. Furthermore, immunohistochemical staining was employed to detect the expression of osteogenic and chondrogenic-related molecules. Scaffold characterization revealed that surface modification enables the uniform distribution of n-HApMA within the GelMA matrix. The incorporation of 5% n-HApMA notably enhanced the elastic modulus and stiffness of the 6% high-porosity GelMA in comparison to n-HAp. Moreover, in-vivo study showed that the homogeneous dispersion of n-HApMA on the GelMA matrix facilitated the osteogenic differentiation of adipose-derived stem cells (ADSCs) and promoted osteochondral tissue regeneration. These findings suggest potential applications of the n-HApMA/GelMA composite in the field of tissue engineering and regenerative medicine.

The effect of intravenous lipid emulsion (ILE) on the pharmacokinetic/toxicokinetic dispositions of ivermectin and carprofen in rabbits.

Intravenous lipid emulsion (ILE) has been widely used as an effective antidote in both veterinary and human medicine for the treatment of acute intoxications caused by drugs and pesticides with high lipid solubility. This study was conducted to investigate the effect of ILE co-administration on the kinetic dispositions of ivermectin (IVM) and carprofen (CRP) following intravenous bolus administration at subtoxic doses in rabbits.Twenty-four male New Zealand rabbits weighing 2.78 ± 0.2kg were used in this study. Rabbits were divided into four groups (Group 1: IVM and Group 2: IVM + ILE or Group 3: CRP and Group 4: CRP + ILE), each group consisting of 6 animals. In the IVM study, Group 1 received IVM (0.6mg/kg) alone while Group 2 received IVM (0.6mg/kg) and ILE (2.5ml/kg). In the CRP study, Group 3 received CRP (12mg/kg) alone while Group 4 received CRP (12mg/kg) and ILE (2.5ml/kg). In both drug groups, ILE was administered 3 times as an i.v. bolus at the 10th min and repeated 4th and 8th h after the drug administration. Blood samples were collected from the auricular vein at various times after drug administration. The drug concentrations in plasma samples were determined by high-pressure liquid chromatography. Kinetic parameters were calculated using a non-compartmental model for both CRP and IVM.The C0 and area under the concentration-time curve from zero up to ∞ (AUC0-∞) values were significantly greater with ILE co-administration (2136ng/ml and 360.84ng.d/ml) compared to the IVM alone (1340.63ng/ml and 206ng.d/ml), respectively. Moreover, the volume of distribution (Vdss) and clearance (Cl) of IVM were reduced by approximately 42% and 46% with ILE co-administration compared to IVM alone resulting in a reduction of the distribution and slower elimination, respectively. Similar differences in C0, and Vdss values were also observed in CRP with ILE co-administration compared to CRP alone. ILE co-administration changed significantly the kinetic profile of both IVM and CRP in rabbits, supporting the lipid sink theory in which highly lipid-soluble compounds are absorbed into the lipid phase of plasma from peripheral organs such as the heart and brain affected by the acute toxicity of the compounds.

Clinical course and pathogenicity of a Mycobacterium avium subsp. paratuberculosis isolate from scimitar oryx (Oryx dammah) in experimentally infected rabbits

Aim of study: To evaluate the infectivity of a MAP type C of a scimitar oryx (Oryx dammah) - included in an international conservation list - that showed clinical signs and granulomatous enteritis associated with paratuberculosis in rabbits (Oryctolagus cuniculus) using molecular, bacteriological and pathological methodologies. Area of study: The study was made in Tequisquiapan, Queretaro, CEIEPAA, FMVZ, UNAM, Mexico. Material and methods: Three 6-week-old female New Zealand rabbits were orally infected for 3 consecutive days with 109 CFU of the MAP isolate. Blood and fecal samples were collected every 2 weeks for a total period of 28 weeks. IS900 PCR in blood and F57 real-time PCR in the feces were performed every 2 weeks and pathological analysis and bacteriological culture from tissue were made 28 weeks post infection. Main results: MAP was detected by IS900 PCR in the blood of two of the three animals after 2 weeks of infection and again by F57 real-time PCR in the feces of the three infected rabbits. Infection with the MAP isolates in feces at 22 and 28 weeks post infection in one rabbit and isolate of vermiform appendix resulted in the development of granulomatous lesions in the three rabbits. The lesions were diffuse intermediate in one animal and multifocal in the other two rabbits. Research highlights: Overall, these results demonstrated the infectivity of a MAP isolate from the scimitar oryx in rabbits.

Enhanced wound healing and hemostasis with exosome-loaded gelatin sponges from human umbilical cord mesenchymal stem cells.

Rapid wound healing remains a pressing clinical challenge, necessitating studies to hasten this process. A promising approach involves the utilization of human umbilical cord mesenchymal stem cells (hUC-MSCs) derived exosomes. The hypothesis of this study was that these exosomes, when loaded onto a gelatin sponge, a common hemostatic material, would enhance hemostasis and accelerate wound healing. To investigate the hemostatic and wound healing efficacy of gelatin sponges loaded with hUC-MSCs-derived exosomes. Ultracentrifugation was used to extract exosomes from hUC-MSCs. Nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blot techniques were used to validate the exosomes. In vitro experiments were performed using L929 cells to evaluate the cytotoxicity of the exosomes and their impact on cell growth and survival. New Zealand rabbits were used for skin irritation experiments to assess whether they caused adverse skin reactions. Hemolysis test was conducted using a 2% rabbit red blood cell suspension to detect whether they caused hemolysis. Moreover, in vivo experiments were carried out by implanting a gelatin sponge loaded with exosomes subcutaneously in Sprague-Dawley (SD) rats to perform biocompatibility tests. In addition, coagulation index test was conducted to evaluate their impact on blood coagulation. Meanwhile, SD rat liver defect hemostasis model and full-thickness skin defect model were used to study whether the gelatin sponge loaded with exosomes effectively stopped bleeding and promoted wound healing. The NTA, TEM, and western blot experimental results confirmed that exosomes were successfully isolated from hUC-MSCs. The gelatin sponge loaded with exosomes did not exhibit significant cell toxicity, skin irritation, or hemolysis, and they demonstrated good compatibility in SD rats. Additionally, the effectiveness of the gelatin sponge loaded with exosomes in hemostasis and wound healing was validated. The results of the coagulation index experiment indicated that the gelatin sponge loaded with exosomes had significantly better coagulation effect compared to the regular gelatin sponge, and they showed excellent hemostatic performance in a liver defect hemostasis model. Finally, the full-thickness skin defect healing experiment results showed significant improvement in the healing process of wounds treated with the gelatin sponge loaded with exosomes compared to other groups. Collectively, the gelatin sponge loaded with hUC-MSCs-derived exosomes is safe and efficacious for promoting hemostasis and accelerating wound healing, warranting further clinical application.

Effect of acupotomy on mitophagy mediated by PINK1/Parkin pathway in cartilage of rabbits with knee osteoarthritis

To observe the effect of acupotomy on mitophagy mediated by PINK1/Parkin pathway in cartilage of rabbits with knee osteoarthritis (KOA), so as to explore its mechanism in inhibiting cartilage damage. Twenty-one New Zealand rabbits were randomly divided into normal, model, and acupotomy groups, with 7 rabbits in each group. The KOA rabbit model was established by using the Videman method. Rabbits in the acupotomy group received regular acupotomy treatment around the knee joint nodules or tendons once a week for 3 consecutive weeks. HE staining and transmission electron microscopy were used to observe the morphological and ultrastructural changes in knee joint cartilage of rabbits. Flow cytometry was used to measure the mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS) average fluorescence intensity in chondrocytes. Immunofluorescence was performed to detect the fluorescence intensity of LC3B, PINK1 and Parkin in cartilage tissue. Western blot was conducted to measure the protein expression levels of p62, LC3Ⅱ/Ⅰ, PINK1, and Parkin in cartilage tissue. Compared to the normal group, the model group showed fissures and tissue fibrosis on the surface of rabbit knee joint cartilages, loose distribution of chondrocytes, decreased autophagosomes, and abnormal mitochondrial morphology. The fluorescence intensity of LC3B, PINK1 and Parkin, the expression levels of LC3Ⅱ/Ⅰ, PINK1 and Parkin proteins in cartilage tissue were significantly decreased (P<0.01), while the percentage of chondrocytes with low Δψm, the average fluorescence intensity of ROS, and the expression of p62 protein in cartilage tissue were significantly increased (P<0.01). Compared to the model group, the acupotomy group showed no obvious defects on the surface of rabbit knee joint cartilage, relatively dense distribution of chondrocytes, increased autophagosomes, and relatively normal mitochondrial morphology. The fluorescence intensity of LC3B, PINK1 and Parkin, the expression of LC3Ⅱ/Ⅰ, PINK1 and Parkin proteins in cartilage tissue were significantly increased (P<0.01, P<0.05), while the percentage of chondrocytes with low Δψm, the average fluorescence intensity of ROS, and the expression of p62 protein in cartilage tissue were significantly decreased (P<0.01). Acupotomy may promote mitophagy by regulating the PINK1/Parkin pathway, thereby improving cartilage damage in rabbits with KOA.

Pepsin concentration in oral lavage fluid of rabbit reflux model constructed by dilating the lower esophageal sphincter.

The aim of this study was to explore the changes in pH and pepsin concentrations in oral lavage fluid of rabbit reflux model. A total of 18 New Zealand rabbits were randomly divided into two groups. The lower esophageal sphincters (LESs) of the rabbits in the experimental group (EG) were dilated by balloon after the LESs were localized by manometry. The pH levels of the throat and the lower esophagus were monitored 1 week before and 2 weeks after inflation. Oral lavage fluid was collected 1 week before, and 2 and 8 weeks after inflation. The pH monitoring showed that the percentage of reflux time, the number of reflux events, and the longest time of reflux after the dilation (AE) in the EG were significantly higher than before the dilation (P < 0.01). The pepsin concentrations at 2 and 8 weeks AE in the EG were significantly higher than that before and that in the control group (P < 0.05). Based on receiver operating characteristic curve analysis, the best diagnostic threshold value was 30.3 ng/ml. The reflux model constructed by balloon inflation of the LES in rabbits is characterized by a decrease in throat pH and an increase in salivary pepsin concentration.

DIAGNOSIS OF ENCEPHALITOZOON CUNICULI IN NEW ZEALAND RABITS BY SOME HISTOLOGICAL METHODS

The aim of this study was to determine the histopathological lesions associated with Encephalitozoon cuniculi (E. cuniculi) infection in 25 New Zealand rabbits randomly selected in a laboratory animal center. Microscopic lesions were evaluated on sample slides stained with HE, Gram, and Immunohistochemistry (IHC) techniques. Mild and moderate lesions included granulomatous inflammation, meningitis, and perivascular cuffing were identified in brain samples; interstitial nephritis and renal fibrosis were identified in the kidneys of 21 out of 25 rabbits. Among the 21 rabbits, the percentage of spore identification by HE and Gram staining methods were 9.5% and 71%, respectively while IHC revealed parasite antibody in 81% of the rabbits. Thus, laboratory New Zealand rabbits in Vietnam might be infected with high prevalence of E. cuniculi. Postmortem diagnosis with HE technique can be used for screening [i]while Gram and IHC staining can confirm the infections. The rabbit husbandry units should consider appropriate methods for infection assessment and control.&#x0D; &#x0D; [i]

Anastomosis between the facial nerve - ansa cervicalis and the facial nerve - hypoglossal nerve in rabbits: technical note for a practical use in peripheral facial palsy.

To emphasize the importance of laboratory dissections in perfecting surgical techniques. In this paper, we describe the technical details on rabbit dissection for practical applications. Four New Zealand rabbits were distributed into two groups and underwent anastomosis between the Facial Nerve and Ansa Cervicalis (group 1) and between the Facial Nerve and Hypoglossal Nerve (group 2). They were clinically and neurophysiologically evaluated after ten weeks. Electroneurography with skin electrodes were used to identify the motor activity of the involved muscles and nerves. Facial and ipsilateral tongue reinnervation was analyzed 40 weeks after anastomosis. Evoked electromyographic muscle tension was used to evaluate facial and tongue reinnervation. Facial and ipsilateral tongue reinnervation was analyzed 40 weeks after anastomosis. Recorded evoked potentials showed improvement in facial reinnervation in all four rabbits. Rabbits undergoing FN-HN anastomosis still showed ipsilateral lingual paresis, based on EMG tests. The survival rate was 100%. The laboratory dissection plays a crucial role in training surgical specialists to achieve favorable patient outcomes. Both types of anastomosis can be used to achieve facial reinnervation; however, it is imperative to prevent ipsilateral lingual paralysis that may arise from using the hypoglossal nerve.

Untargeted metabolomics study of dexamethasone-induced congenital cleft palate in New Zealand rabbits

Objective: To investigate the metabolic disorders in placental tissues of dexamethasone induced cleft palate mode. Methods: Twelve pregnant rabbits were randomly divided into dexamethasone group (experimental group, 8) and saline control group (4), and a certain amount of dexamethasone and saline were administered intramuscularly to the experimental and control groups respectively from embryonic days (ED) 13 to 16, and placental tissue samples were collected on day 21 of gestation. The corresponding profiles of the embryonic placental tissue samples were obtained by liquid chromatography-triple tandem quadrupole(LC-MS), and the metabolites of the embryonic placental tissues were characterized by principal component analysis among the dexamethasone-treated group with cleft palate (D-CP group), the dexamethasone-treated group without cleft palate (D-NCP group) and the control group. Results: There were significant metabolic differences among the D-CP group, D-NCP group and control group, with a total of 133 differential metabolites (VIP>1, P<0.05) involving in important metabolic pathways including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism, and galactose metabolism. The four metabolites, vitamin B6, galactose, lysine and urea, differed among the three groups (P<0.05). There were significant differences in vitamin B6 (0.960±0.249, 0.856±0.368, 1.319±0.322), galactose (0.888±0.171, 1.033±0.182, 1.127±0.127), lysine (1.551±0.924, 1.789±1.435, 0.541±0.424) and urea (0.743±0.142, 1.137±0.301, 1.171±0.457, respectively) levels among control group, D-NCP group and D-CP group (F=5.90, P=0.008; F=5.59, P=0.009; F=4.26, P=0.025; F=5.29, P=0.012). Conclusions: The results indicated that dexamethasone induced cleft palate may be highly correlated with metabolic disorders including vitamin B6 metabolism, lysine metabolism, arginine anabolic metabolism and galactose metabolism.