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Simple Summary: Rabbit hemorrhagic disease virus 2 (RHDV2) was reported in the United States in 2018 and has since spread across most of the country where it has a potential for adverse impacts on ecosystems, economic losses, and pet rabbit health. Using an emergency use authorized vaccine, seroconversion and protection was demonstrated in 3- to 7-week-old specific pathogen free laboratory rabbits. The purpose of the current study was to examine this protocol in pet rabbits, which would be inclusive of varied breeds and ages. Importantly, no significant differences were observed in routine clinical pathology measures. Seroconversion was also observed but was variable, and lower levels of seroconversion were associated with increased age. In general, while variable outcomes to vaccination are expected, these preliminary data underlie the importance of examining the response of pet rabbits to help optimize new vaccine protocols. We propose this will complement traditional vaccine studies, aid in maintaining the health of pet rabbits, and help in the ultimate control of this highly infectious virus. A recombinant vaccine for rabbit hemorrhagic disease virus 2, a highly pathogenic virus, was granted emergency use authorization in the United States after the detection and spread of the virus starting in 2018. The goal of the current study was to assess pet rabbits (n = 29) through physical examination and routine clinical pathology testing using repeated assessments post-vaccination. In addition, seroconversion was also monitored after the initial vaccination and booster vaccination. Neither owners nor clinicians detected any physical abnormalities in relationship to the vaccine protocol. Hematological and clinical biochemistry testing showed some changes although median values were within species specific reference intervals. A significant increase in antibody levels was observed at day 21 (post-initial vaccination) and day 49 (post-booster vaccination) versus that present at baseline (p < 0.0001). However, variability in study rabbits was noted with some individuals showing low antibody levels as well as a lower overall response in older rabbits (r = −0.56, p = 0.006). A second cohort of rabbits was assessed at 11–12 months post-initial vaccination. In this second group, antibody levels were not significantly different from baseline levels (p = 0.21). Additional studies should be conducted to further define the variability in seroconversion and the term of protection in pet rabbits as the industry moves forward in the optimization of RHDV2 vaccines. [ABSTRACT FROM AUTHOR]

Cryopreservation and re-transplantation of ovarian tissue is a relatively new technique to preserve fertility. This study evaluated the preservation of ovarian follicles after the vitrification-thawing procedure by implanting ovarian fragments into the gluteus muscle of rabbit. Bilateral ovariectomy was performed on each rabbit. The cortices were separated from the medullae of ovaries and divided into four fragments. One fresh cortical fragment was used as a control, fixed in 10.00% formalin. Three fragments underwent vitrificationthawing for two weeks. Two of these vitrified-thawed fragments were auto-transplanted into separate locations within the opened gluteus muscle, while the final fragment was fixed in 10.00% formalin. Eight weeks after re-implantation, biopsies were collected from the ovarian fragments and fixed in 10.00% formalin. The numbers and areas (µm²) of morphologically normal follicles were evaluated on sections stained with Hematoxylin and Eosin through light microscopy. The follicular morphology in the ovarian fragments immediately after vitrification-thawing remained similar to that of the fresh ovary. The number of morphologically intact follicles was significantly lower in the ovarian fragments eight weeks after re-implantation than fresh ovary and ovarian tissue fragments after vitrification-thawing procedure. However, follicular development to the antral stage was observed in all samples eight weeks after re-implantation. There was no statistical difference in the areas (µm²) of primordial, primary, pre-antral, and antral follicles in the ovarian fragments before cryopreservation, immediately after vitrification-thawing, and following re-implantation procedures. Auto-transplantation of ovarian tissue into the gluteus muscle of rabbits could be a viable approach for preserving ovarian follicles after vitrification-thawing procedure. [ABSTRACT FROM AUTHOR]

Domestic rabbits (Oryctolagus cuniculus) are commonly kept as pets or bred for laboratory investigation, meat, fur production, or a combination of these purposes. We conducted a retrospective study to assess the prevalence of diseases in domestic rabbits according to purpose. We retrieved results of autopsies, biopsies, and cytologies from 2,583 cases received at 4 diagnostic laboratories in California from 2013–2022. Rabbits were classified as pets (2,241; 86.8%), laboratory animals (92; 3.6%), meat-production animals (60; 2.3%), or multipurpose animals (190; 7.4%). A final diagnosis was reached in 2,360 (91.4%) cases and was classified by system, etiology, and type of process. Pet rabbits had the highest median age (5.9 y; vs. 3 y, 0.67 y, and 0.25 y in meat, multipurpose, and laboratory rabbits, respectively), and most of the neoplasms were diagnosed in this group (872 of the total 896 neoplasms in the study; 97.3%), with tumors of the skin, female reproductive tract, and hematolymphoid system being the most common. Laboratory rabbits had a high prevalence of infectious enterotyphlocolitis (40 of 92; 43.4%), and ~45% of those cases were due to opportunistic colibacillosis. Infectious and parasitic pneumonias were common in meat rabbits (18 of 60; 30%); pneumonic pasteurellosis accounted for >60% of those cases. Infectious cholangiohepatitides were common in multipurpose rabbits (61 of 110; 55.5%), with rabbit hemorrhagic disease representing the most common etiology (82.4% of those cases). Our results demonstrate that purpose of use can predict prevalence of disease in rabbits submitted to diagnostic laboratories. [ABSTRACT FROM AUTHOR]

Mycotoxicoses are usually a consideration in large animal species but can affect companion animals as well. Due to increasing interest and the ease of using rabbits as laboratory models, a growing number of published experimental studies discuss the effects of various mycotoxins on this species. However, the available evidence is fragmented and heterogeneous, and has not recently been collated in a review, to my knowledge. Although mycotoxicoses in rabbits are typically subclinical, clinical signs can include weight loss, anorexia, gastrointestinal disorders, stunted growth, reproductive abnormalities, and susceptibility to infections. An antemortem diagnosis typically relies on a comprehensive clinical history, and assessment of clinical signs and relevant laboratory findings, with confirmation of exposure achieved through the measurement of mycotoxin concentrations in feed or target organs. My review focuses on the clinicopathologic and histopathologic effects of the mycotoxins most important in rabbits, including fumonisins, ochratoxins, aflatoxins, trichothecenes, and zearalenone. This review offers a thorough overview of the effects of mycotoxins in rabbits, serving as a one-stop resource for veterinary practitioners, diagnosticians, and researchers. [ABSTRACT FROM AUTHOR]

The problem of cataract prevalence makes it necessary to develop innovative technologies for eye microsurgery. An innovative hydrodynamic scheme has been developed by a team of researchers. Its essence lies in the fact that when the vacuum level in the aspiration line reaches critical figures and remains at this level for a specified time, the system recognizes this state as occlusion and smoothly reduces the vacuum to a preset value while maintaining occlusion. The purpose of this scientific study is to study morphological changes in the cornea of rabbits' eyes after experimental modeling of a post-occlusion wave using a new hydrodynamic scheme of a phaco-emulsifier. The study was conducted on 32 eyes of 16 white laboratory rabbits, using traditional technology and an innovative hydrodynamic scheme, as well as needles of various diameters. The pieces of the cornea were carefully examined using a light microscope. The least damage to the cornea of the eye was found in the fourth group of rabbits, where an innovative hydrodynamic scheme was used in combination with a thin needle d = 0.9 mm. [ABSTRACT FROM AUTHOR]

Even among vaccinated rabbits, the virus that causes rabbit viral hemorrhagic disease (RHDV) has been increasing in Egypt recently. So, the current study screened the emergent RHDV of vaccinated and unvaccinated domestic rabbits in some Egyptian provinces between 2022 and 2023. 40 pooled Samples were collected from different rabbit flocks with age range of 2 months up to 4 months with high mortality rates, clinical symptoms, and post-mortem lesions related to RHDV. Hemagglutination (HA) test, reverse transcriptase-polymerase chain reaction (RT-PCR) targeting the partial VP60 and sequencing and phylogenetic analysis were conducted for genotyping of RHDV strains. The results revealed that 16 out of 40 cases that were positive for RHDV and were hemagglutinin-positive, with titer ranging from 2³ to 214 Randomly six isolates were selected for genetic sequence and phylogenetic analysis which revealed their clustering with RHDV2 strains which were detected for the first time in Upper Egypt and submitted on GenBank as (OQ925947 Assiut .vac1 to OQ925952Assiut .vac6). The nucleotide sequence identities of the six isolates were 98.8-100 % compared to each other. The recently isolated strains had nucleotide difference 23, 1 % when compared to commonly vaccinal strain (JQ995154Giza 2006). The inoculated rabbits expressed RHDV-typical signs and postmortem findings and Ninety percent (90 %) mortality rate was recorded within3-6 days post-infection. Microscopic examination revealed that presence of acute necrotizing hepatitis, congestion and widespread hemorrhages in all internal organs; liver, lungs, spleen, kidneys and brain. In conclusion, the presence of RHDV- 2 strains was detected for the first time in some Upper Egypt provinces. [ABSTRACT FROM AUTHOR]

Copyright of Kocatepe Veterinary Journal / Kocatepe Veteriner Dergisi is the property of Afyon Kocatepe University, Faculty of Veterinary Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Group B Streptococcus (GBS) is a life-threatening opportunistic pathogen, particularly in pregnant women, infants, and the elderly. Currently, maternal vaccination is considered the most viable long-term option for preventing GBS mother-to-infant infection, and two polysaccharide conjugate vaccines utilizing CRM197 as a carrier protein have undergone clinical phase II trials. Surface immunogenic protein (Sip), present in all identified serotypes of GBS strains so far, is a protective surface protein of GBS. In this study, the type Ia capsular polysaccharide (CPS) of GBS was utilized as a model to develop candidate antigens for a polysaccharide conjugate vaccine by coupling it with the Sip of GBS and the traditional carrier protein CRM197. Serum analysis from immunized New Zealand rabbits and CD1 mice revealed that there was no significant difference in antibody titers between the Ia-Sip group and Ia-CRM197 group; however, both were significantly higher than those observed in the Ia polysaccharide group. Opsonophagocytosis and passive immune protection results using rabbit serum indicated no significant difference between the Ia-Sip and Ia-CRM197 groups, both outperforming the Ia polysaccharide group. Furthermore, serum from the Ia-Sip group had a cross-protective effect on multiple types of GBS strains. The challenge test results in CD1 mice demonstrated that the Ia-Sip group provided complete protection against lethal doses of bacteria and also showed cross-protection against type III strain. Our study demonstrates for the first time that Ia-Sip is immunogenic and provides serotype-independent protection in glycan conjugate vaccines, which also indicates Sip may serve as an excellent carrier protein for GBS glycan conjugate vaccines and provide cross-protection against multiple GBS strains. [ABSTRACT FROM AUTHOR]

Copyright of Scientific-Practical Journal of Medicine Vestnik KazNMU is the property of Asfendiyarov Kazakh National Medical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Escherichia coli, including extended-spectrum β-lactamases (ESBL)-producing strains, poses a global health threat due to multidrug resistance, compromising food safety and environmental integrity. In industrial settings, rabbits raised for meat have the highest consumption of antimicrobial agents compared to other food-producing animals. The European Union is facing challenges in rabbit farming as rabbit consumption declines and antibiotic-resistant strains of E. coli cause enteric diseases. The aim of this study was to investigate the antibiotic resistance profile, genetic diversity, and biofilm formation in cefotaxime-resistant E. coli strains isolated from twenty rabbit farms in Northern Portugal to address the effect of the pressing issue of antibiotic resistance in the rabbit farming industry. Resistance to critically antibiotics was observed, with high levels of resistance to several categories, such as tetracycline, ampicillin, aztreonam, and streptomycin. However, all isolates were susceptible to cefoxitin and imipenem. Multidrug resistance was common, with strains showing resistance to all antibiotics tested. The blaCTX-M variants (blaCTX-3G and blaCTX-M9), followed by the tetracycline resistance genes, were the most frequent resistance genes found. ST10 clones exhibiting significant resistance to various categories of antibiotics and harboring different resistance genes were detected. ST457 and ST2325 were important sequence types due to their association with ESBL-E. coli isolates and have been widely distributed in a variety of environments and host species. The strains evaluated showed a high capacity for biofilm formation, which varied when they were grouped by the number of classes of antibiotics to which they showed resistance (i.e., seven different classes of antibiotics, six classes of antibiotics, and three/four/five classes of antibiotics). The One Health approach integrates efforts to combat antimicrobial resistance in rabbit farming through interdisciplinary collaboration of human, animal, and environmental health. Our findings are worrisome and raise concerns. The extensive usage of antibiotics in rabbit farming emphasizes the urgent need to establish active surveillance systems. [ABSTRACT FROM AUTHOR]

The roles of experimental animals in orthopedic research is very crucial for the management of bone defects. Given the various drawbacks of the vascularised periosteal graft, researchers began to explore the effectiveness of non-vascularised periosteal graft in fracture healing management. Small laboratory animals especially rabbits have been widely used for non-vascularised periosteal transplantation research but with more challenges of obtaining a good graft size. Therefore, bigger animals, such as sheep--with more morphological and physiological similarities to human are used as animal model for surgical procedures. The article elaborates the features of periosteum, comparative anatomy of sheep's hind limb, pre-surgical preparation, and surgical procedure for the transplantation of non-vascularised periosteal graft, especially for researchers operating on sheep for the first time. A male sheep of 4-month-old was used for this procedure. Periosteal graft was harvested from tibia and transplanted to femur to mimic treatment of bone gap in orthopedic surgery. [ABSTRACT FROM AUTHOR]

Ovine herpesvirus 2 (OvHV-2) and bovine herpesvirus 4 (BoHV-4) are gamma herpesviruses that belong to the genera Macavirus and Rhadinovirus, respectively. As with all herpesviruses, both OvHV-2 and BoHV-4 express glycoprotein B (gB), which plays an essential role in the infection of host cells. In that context, it has been demonstrated that a BoHV-4 gB-null mutant is unable to infect host cells. In this study, we used homologous recombination to insert OvHV-2 ORF 8, encoding gB, into the BoHV-4 gB-null mutant genome, creating a chimeric BoHV-4 virus carrying and expressing OvHV-2 gB (BoHV-4∆gB/OvHV-2-gB) that was infectious and able to replicate in vitro. We then evaluated BoHV-4∆gB/OvHV-2-gB as a potential vaccine candidate for sheep-associated malignant catarrhal fever (SA-MCF), a fatal disease of ungulates caused by OvHV-2. Using rabbits as a laboratory model for MCF, we assessed the safety, immunogenicity, and efficacy of BoHV-4∆gB/OvHV-2-gB in an immunization/challenge trial. The results showed that while BoHV-4∆gB/OvHV-2-gB was safe and induced OvHV-2 gB-specific humoral immune responses, immunization conferred only 28.5% protection upon challenge with OvHV-2. Therefore, future studies should focus on alternative strategies to express OvHV-2 proteins to develop an effective vaccine against SA-MCF. [ABSTRACT FROM AUTHOR]

One of the basic conditions for the clinical success of osseo-integrated implants is implant stability (Albrektsson and Zarb, 1993). It comprises two components, the primary stability that should be ensured at the time of insertion and the secondary stability, which gradually replaces the primary stability. The primary stability is ensured by the direct contact between the implant surface and that of the bone walls of the insertion hole. Secondary stability begins with the first position of new bone on the implant surface. The aim of the present study was to verify the reinforcing structures proliferated around the titanium implant inserted into the femur of 5 adult female rabbits, in a groove smaller than the screw core diameter. The results suggested that inserting the titanium implant into a hole with a smaller diameter than the screw core produces excessive pressure on the bone, which is felt up to a distance from the bone-implant interface. Consequently, mechanical strength of the bone is decreasing and proliferating bone consolidation formations appears on both periosteum and endosteum areas. Additionally, it was observed that newly proliferated bone extends laterally from the interface to a great distance, causing thickening of the bone wall. The observed structures were represented by branched bone trabeculae and bony protrusions into the medullary cavity, together with bone reshuffling processes with the appearance of numerous osteons, most of which are present at the level of the wall opposite the insertion area. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Laboratory Animal Science & Practices / Laboratuvar Hayvanlari Bilimi ve Uygulamalari Dergisi is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To evaluate and compare the effects of two restorative materials with different stiffness on peri-implant bone microstrain and implant micromovements during occlusal loading in implant-supported single and adjacent splinted crowns. Materials and Methods: Two 3 × 10-mm implants were inserted into the tibia of four rabbits. During the osseointegration process, prosthetic restorations were performed. Before suturing the flap, each implant's position and direction were obtained by fastening two splinted transfer abutments, onto which implant analogs were placed and fastened; the splinted transfer abutments were subsequently unfastened. Splinted transfer abutment/analog complexes were cast using type IV plaster to obtain eight different working models. Two single mandibular premolar crowns of monolithic zirconia and acrylate polymer composite were generated using CAD/CAM technology, and 16 adjacent splinted crowns (eight of each material) with the same design were also generated. After 6 weeks of implant osseointegration, the animals were sacrificed. Tibial sections with the implants were extracted, and prosthetic restorations (performed during implant osseointegration) were fastened to the implants. Static loading tests were performed with 100-N force application and an inclination of 6 degrees over the central fossa of the premolars. Implant micromovement was measured using an image analysis technique. Bone microstrain was quantified using two strain gauges placed on the crestal bone around the implants. Data were analyzed using two-way analysis of variance. Results: The mean implant micromovement values were lower for monolithic zirconia single and splinted crowns (61.5 ± 26.3 µm and 57.7 ± 8.8 µm, respectively) than for acrylate polymer composite-based single and splinted crowns (78.9 ± 37.3 µm and 59.61 ± 11.5 µm, respectively). No significant differences between the materials were noted. Bone microstrain around the implants was lower for splinted crowns (303.7 ± 281.3 µe for acrylate polymer composite; 312.4 ± 226.8 µe for monolithic zirconia) than for single crowns (539.7 ± 8.8 µe for acrylate polymer composite; 574.6 ± 271.9 µe for monolithic zirconia). Conclusion: Using restorative materials of different stiffness did not significantly affect the micromovement of already-osseointegrated implants supporting single or splinted crowns. Independent of material stiffness, single crowns transfer significantly more microstrain than splinted crowns. [ABSTRACT FROM AUTHOR]

Background: Immunoglobulin A (IgA) is the mammalian mucosal antibody, providing an important line of defense against pathogens. With 15 IgA subclasses, the European rabbit has an extremely complex IgA system, strikingly more complex than most other mammals, which have only one IgA or, in the case of hominoids, two IgA subclasses. Similar to the two hominoid primate IGHA genes, the expansion of the rabbit IGHA genes appears to have begun in an ancestral lagomorph since multiple IgA copies were found by Southern blot analysis for the genera Sylvilagus, Lepus, and Ochotona. Results: To gain a better insight into the extraordinary lagomorph IgA evolution, we sequenced, for the first time, expressed IgA genes for two Lepus species, L. europaeus and L. granatensis. These were aligned with the 15 rabbit IgA isotypes, and evolutionary analyses were conducted. The obtained phylogenetic tree shows that the Lepus IgA sequences cluster with and among the rabbit IgA isotypes, and the interspecies and intraspecies nucleotide genetic distances are similar. A comparison of the amino acid sequences of the Lepus and rabbit IgA confirms that there are two trans-species polymorphisms and that the rabbit and Lepus sequences share a common genetic pool. In fact, the main differences between the studied leporids IgAs reside in the characteristics of the hinge region. Conclusion: The Lepus IgA sequences we have obtained strongly suggest that the great expansion of the leporid IGHA genes occurred in a common ancestral species and was then maintained in the descendants. A strong selective pressure caused the extraordinary expansion of the IGHA genes but then subsided, leading to the maintenance of the acquired polymorphisms in the descendants, with little subsequent divergence. This is a unique evolutionary pattern in which an ancient gene expansion has been maintained for approximately 18 million years. [ABSTRACT FROM AUTHOR]

Background: Envenomations by African snakes represent a high burden in the sub-Sahara region. The design and fabrication of polyspecific antivenoms with a broader effectiveness, specially tailored for its use in sub-Saharan Africa, require a better understanding of the immunological features of different Naja spp. venoms of highest medical impact in Africa; and to select the most appropriate antigen combinations to generate antivenoms of wider neutralizing scope. Methodology/principal findings: Rabbit-derived monospecific antisera were raised against the venoms of five spitting cobras and six non-spitting cobras. The effects of immunization in the animal model were assessed, as well as the development of antibody titers, as proved by immunochemical assays and neutralization of lethal, phospholipase A2 and dermonecrotic activities. By the end of the immunization schedule, the immunized rabbits showed normal values of all hematological parameters, and no muscle tissue damage was evidenced, although alterations in aspartate aminotransferase (AST) and alkaline phosphatase (ALP) suggested a degree of hepatic damage caused mainly by spitting cobra venoms. Immunologic analyses revealed a considerable extent of cross-reactivity of monospecific antisera against heterologous venoms within the spitting and no-spitting cobras, yet some antisera showed more extensive cross-reactivity than others. The antisera with the widest coverage were those of anti-Naja ashei and anti-N. nigricollis for the spitting cobras, and anti-N. haje and anti-N. senegalensis for the non-spitting cobras. Conclusions/significance: The methods and study design followed provide a rationale for the selection of the best combination of venoms for generating antivenoms of high cross-reactivity against cobra venoms in sub-Saharan Africa. Results suggest that venoms from N. ashei, N. nigricollis within the spitting cobras, and N. haje and N. senegalensis within the non-spitting cobras, generate antisera with a broader cross-reactivity. These experimental results should be translated to larger animal models used in antivenom elaboration to assess whether these predictions are reproduced. Author summary: The African elapids pose a major potential to induce clinically important envenomations and severe sequelae after a snakebite accident. Within the genus Naja, different radiation events have occurred rendering the African cobras with diverse features in their venom composition. Commonly divided into spitting and non-spitting cobras, their venom is characterized as either cytotoxic or neurotoxic, respectively, based on the pathophysiology of envenomation. In this study, an experimental protocol was developed based on the generation of monospecific antisera in rabbits immunized with venoms of spitting and non-spitting African cobras. Cross-reactivity of monospecific antisera was assessed by immunochemical analyses and by neutralization of the lethal, phospholipase A2 (PLA2) and dermonecrotic activities. Results showed a large extent of intrageneric cross-reactivity by all antisera, yet few exceptions were noticed. The venoms that generated antisera with the highest cross-neutralization ability among the spitting cobras were Naja nigricollis and N. ashei, whereas for the non-spitting cobras were N. haje and N. senegalensis. These results provide evidence for the selection of the best combination of immunogens for antivenom production with the widest neutralization scope within the African cobras. Additionally, the results obtained in the rabbit model should be translated to a larger animal model used for antivenom fabrication to assess whether these predictions are confirmed. [ABSTRACT FROM AUTHOR]

Cysticercosis pisiformis, a highly prevalent parasitic disease worldwide, causes significant economic losses in the rabbit breeding industry. Previous investigations have identified a novel microRNA, designated as novel-miR1, within the serum of rabbit infected with Cysticercus pisiformis. In the present study, we found that C. pisiformis-derived novel-miR1 was released into the rabbit serum via exosomes. Through computational analysis using TargetScan, miRanda, and PITA, a total of 634 target genes of novel-miR1 were predicted. To elucidate the functional role of novel-miR1, a dual-luciferase reporter assay was utilized and demonstrated that novel-miR1 targets rabbit Toll-like receptor 2 (TLR2). Rabbit peripheral blood lymphocytes (PBLCs) were transfected with novel-miR1 mimic and mimic NC, and the in vitro experiments confirmed that novel-miR1 suppressed the expression of pro-inflammatory cytokines such as TNF-a, IL-1b, and IL-6 through the nuclear factor kappa B (NF-kB) pathway. In vivo experiments demonstrated that novel-miR1 was significantly upregulated during the 1-3 months following infection with C. pisiformis in rabbits. Notably, this upregulation coincided with a downregulation of TLR2, P65, pP65, TNF-a, IL-1b, and IL-6 in PBLCs. Collectively, these results indicate that the novel-miR1 derived from C. pisiformis inhibited the rabbits' immune response by suppressing the NF-kB-mediated immune response. This immune modulation facilitates parasite invasion, survival, and establishment of a persistent infection. [ABSTRACT FROM AUTHOR]

Background: Plasmodium falciparum cysteine-rich protective antigen (PfCyRPA) is an invasion complex protein essential for erythrocyte invasion. In contrast to several previously clinically tested merozoite vaccine candidate antigens, PfCyRPA is not polymorphic, making it a promising candidate antigen for blood stage vaccine development. Methods: Mice and rabbits were immunized with vaccine formulations of recombinantly expressed PfCyRPA adjuvanted either with the glucopyranosyl lipid A (GLA) containing adjuvants GLA-LSQ, GLA-SE, GLA-Alum or with Nanoalum. ELISA and indirect immunofluorescence assays (IFA) were used to analyse elicited IgG titers and the P. falciparum growth inhibitory activity was determined with a standardized in vitro [3H]-hypoxanthine incorporation assay. Results: In the mouse experiments, the GLA adjuvanted formulations were superior to the Nanoalum formulation with respect to antibody titer development, IFA sero-conversion rates and in vitro parasite growth-inhibitory activity. In rabbits, the highest titers of parasite growth inhibitory antibodies were obtained with the GLA-SE formulation. Comparable mean ELISA IgG endpoint titers were reached in rabbits after three immunizations with GLA-SE adjuvanted PfCyRPA doses of 5, 25 and 100 µg, but with 100 µg of antigen, only two immunizations were required to reach this titer. Conclusion: PfCyRPA formulated with the human-compatible adjuvant GLA-SE represents an attractive vaccine candidate for early clinical testing in a controlled P. falciparum blood stage challenge trial. [ABSTRACT FROM AUTHOR]

The aim of the research was to investigate the effects of different stocking densities on fattening performance, slaughter, carcass, meat quality characteristics, and fatty acid composition in New Zealand rabbits raised in cage conditions and also determine the ideal housing frequency so that yields were not adversely affected. In the study, 36 New Zealand rabbits were used. After weaning, the fattening was started and rabbits were put into cages at different stocking densities as 1 rabbit/cage, 2 rabbits/cage, and 3 rabbits/cage. The live weight of rabbits and feed consumption data were taken every week. At the end of 8 weeks of fattening, slaughtering was carried out and slaughter weights of the rabbits were recorded. The internal organ weights and hot carcass weights were determined. After 24 h, chilled carcass weight and reference carcass weight were defined. As quality parameters of meat; pH, color, cooking loss, water holding capacity, drip loss, and fatty acid composition were determined. In the results of the study, 3 rabbits/cage group had the lowest final live weight (2353.60 g) and daily live weight gain (25.62 g) but 1 rabbit/cage group had the lowest feed conservation ratio (3.56) (p = 0.05). There were no significant differences in dressing out percentage, hot, chilled, and reference carcass weight. Head and hind part percentages were higher for 2 rabbits/cage and 3 rabbits/cage groups (p = 0.05). Stocking density had no relationship between meat quality and fatty acid composition data except b* value for the longissimus dorsi muscle measured at the 24th h and for the biceps femoris muscle measured at the 0th h (p = 0.05). In conclusion, 1 rabbit/cage and 2 rabbits/cage groups had better fattening performance values comparing the 3 rabbits/cage group because of movement area, social and hierarchical behavior between rabbits and advised for laboratory and commercial rabbit breeding for uniformity and profitability. [ABSTRACT FROM AUTHOR]

Background: Rabbits often suffer from dental disease, including dental abscesses and periodontal/apical infections. With odontogenic infection and abscessation, a bacterial aetiology can be proven by bacterial culture and identification. Although studies exist on the bacterial flora of dental abscesses, the information available to date on the bacterial flora of the oral cavity in healthy rabbits is limited. Objectives: This study aims to evaluate the cultivable bacterial flora in the oral cavity of healthy, young, pet rabbits and to compare this flora with the pathologic flora of odontogenic abscesses described in the literature. Methods: Samples were collected from the oral cavity of 33 healthy, young pet rabbits undergoing routine procedures. Oral cavity culture specimens were collected by rolling a sterile flocked paediatric swab in the mouth. Identification was first attempted by morphological assessment, Gram staining and mass spectrometry (MALDI‐TOF). Colonies that could not be identified by mass spectrometry were identified by amplification and molecular sequencing of a part of the 16s rRNA gene. Results: Bacteria were recovered from 100% of oral swabs; 220 isolates of 35 different genera of bacteria were cultured. The most frequently isolated bacteria were Streptococcus sp. (19.8%), Rothia sp. (17.9%), Enterobacter sp. (7%), Staphylococcus sp. (6.6%) and Actinomyces sp. (5.7%). Four phyla are represented: Proteobacteria (38.3%), Firmicutes (30.5%), Actinobacteria (26.9%) and Bacteroidota (4.3%). Conclusions: A wide range of commensal bacteria are present in the mouths of rabbits. Bacterial cultures taken from cases of dental abscesses often reveal bacteria. Streptococcus sp., Staphylococcus sp. and Actinomyces sp. are frequently found in cultures from dental abscesses, in contrast to Rothia and Enterobacter species. Our findings enhance the knowledge of rabbit microbial communities throughout oral cavity. [ABSTRACT FROM AUTHOR]

Laboratory rabbits are fed foods rich with cationic metals, and while fasting cannot empty gastric contents because of their coprophagic habits. This implies that, in rabbits, the oral bioavailability of chelating drugs could be modulated by the slow gastric emptying rates and the interaction (chelation, adsorption) with gastric metals. In the present study, we tried to develop a rabbit model with low amounts of cationic metals in the stomach for preclinical oral bioavailability studies of chelating drugs. The elimination of gastric metals was achieved by preventing food intake and coprophagy and administering a low concentration of EDTA 2Na solution one day before experiments. Control rabbits were fasted but coprophagy was not prevented. The efficacy of rabbits treated with EDTA 2Na was evaluated by comparing the gastric contents, gastric metal contents and gastric pH between EDTA-treated and control rabbits. The treatment with more than 10 mL of 1 mg/mL EDTA 2Na solution decreased the amounts of gastric contents, cationic metals and gastric pH, without causing mucosal damage. The absolute oral bioavailabilities (mean values) of levofloxacin (LFX), ciprofloxacin (CFX) and tetracycline hydrochloride (TC), chelating antibiotics, were significantly higher in EDTA-treated rabbits than those in control rabbits as follows: 119.0 vs. 87.2%, 9.37 vs. 13.7%, and 4.90 vs. 2.59%, respectively. The oral bioavailabilities of these drugs were significantly decreased when Al(OH)3 was administered concomitantly in both control and EDTA-treated rabbits. In contrast, the absolute oral bioavailabilities of ethoxycarbonyl 1-ethyl hemiacetal ester (EHE) prodrugs of LFX and CFX (LFX-EHE, CFX-EHE), which are non-chelating prodrugs at least in in vitro condition, were comparable between control and EDTA-treated rabbits irrespective of the presence of Al(OH)3, although some variation was observed among rabbits. The oral bioavailabilities of LFX and CFX from their EHE prodrugs were comparable with LFX and CFX alone, respectively, even in the presence of Al(OH)3. In conclusion, LFX, CFX and TC exhibited higher oral bioavailabilities in EDTA-treated rabbits than in control rabbits, indicating that the oral bioavailabilities of these chelating drugs are reduced in untreated rabbits. In conclusion, EDTA-treated rabbits were found to exhibit low gastric contents including metals and low gastric pH, without causing mucosal damage. Ester prodrug of CFX was effective in preventing chelate formation with Al(OH)3 in vitro and in vivo, as well as in the case of ester prodrugs of LFX. EDTA-treated rabbits are expected to provide great advantages in preclinical oral bioavailability studies of various drugs and dosage formulations. However, a marked interspecies difference was still observed in the oral bioavailability of CFX and TC between EDTA-treated rabbits and humans, possibly due to the contribution of adsorptive interaction in rabbits. Further study is necessary to seek out the usefulness of the EDTA-treated rabbit with less gastric contents and metals as an experimental animal. [ABSTRACT FROM AUTHOR]

Simple Summary: The complete regeneration of organs after damage is a distant future of regenerative medicine. One of the few rare mammal models of structural tissue restoration is the defect of the elastic cartilage plate in rabbit ear. Understanding why a complex tissue heals into itself and not into a scar brings us closer to controlling innate regenerative potential. In this experiment, we discovered that the regeneration of the elastic cartilage plate was associated with the presence of cells with the senescence-associated secretory phenotype (SASP). We investigated how the presence of these cells was defined by the defect size, and how they correlated with elastic fiber production and clinical outcome. It is possible that SASP cells regulate the structural reparation of the damaged tissue by paracrine signaling, making them a potential pharmaceutical target. Control over endogenous reparative mechanisms is the future of regenerative medicine. The rabbit ear defect is a rare model which allows the observation of the epimorphic regeneration of elastic cartilage. However, the mechanisms of phenotypical restoration of this highly differentiated tissue have not been studied. We modelled circular ear defects of different sizes (4, 6, and 8 mm in diameter) in 12 laboratory rabbits, and observed them during 30, 60, 90, and 120 day periods. Excised tissues were processed and analyzed by standard histological methods and special histochemical reactions for senescence associated-β-galactosidase and lectin markers. We demonstrated that larger defects caused significant elevation of senescence associated-β-galactosidase in chondrocytes. The fullness of epimorphic regeneration of elastic cartilage depended on the activation of cellular senescence and synthesis of elastic fibers. Further investigation into the role of cells with senescence-associated secretory phenotype in damaged tissues can present new targets for controlled tissue regeneration. [ABSTRACT FROM AUTHOR]

Background: This study was conducted for the period from January 2022 until the end of December 2022 at Samarra University / Graduate Studies Laboratory of the College of Applied Sciences, Methods: 50 New Zealand white rabbits with weight ranged from (1500-1800) gm obtained from the National Center for Drug Control and Research in Baghdad, while their ages ranged from (10-14) months.The present study included the effect of Outer Membrane Proteins (OMPs) or (O-Antigen) extracted from Escherichia coli on the immune response in male rabbits infected with G. lamblia parasite, by measuring the levels of cytokines (IL-4, IL-6 and IL-10). Results: The cytokines under study, its level increased in the serum of laboratory rabbits, and our study showed that the level of IL-4 for the O-antigen group increased significantly compared with the negative control group, where its average of concentration was (12.35 and 8.71) pg/ml, respectively. An increase in the level of IL-4 occurred in Challenge group, compared to the positive control, where its average of concentration reached (14.11 and 10.98) pg/ml, respectively. The results of the current study indicated that the level of IL-6 of the O-antigen group increased significantly compared with the negative control group, where its average of concentration was (5.24 and 3.37) pg/ml, respectively, and also the level of IL-6 in Challenge group, it increased non-significantly when compared with the positive control, where its average of concentration was (6.11 and 5.82) pg/ml, respectively. As for IL-10, there was a significant increase in its level in the O-antigen group compared with the negative control group, where average of concentration was (17.17 and 10.41) pg/ml respectively, and the IL-10 levels of Challenge group increased, and it was noted that the IL-10 level increased more than previous compared with the positive control to reach (21.84 and 14.79) pg/ml respectively. Discussion: Immunization of laboratory rabbits with outer membrane proteins purified from E. coli had a clear effect on the levels of under study cytokines, and this led to a reduction in the effect of infection with Giardia lamblia. Conclusions: Elevation of interleukins concentration under study after immunization with O-antigen. The outer membrane proteins extracted from E. coli and at under study concentrations can be considered as non-specific immunomodulators and non-toxic compounds at the specified concentrations and as stimulators of the immune system against infection with the G. lamblia parasite in white laboratory rabbits. [ABSTRACT FROM AUTHOR]

In normal functioning, the blood-aqueous barrier provides ophthalmic homeostasis. The study of the blood-aquatic barrier is carried out in several main directions, one of which is an experimental animal study. In this work, the blood-aquatic barrier's permeability with tetracycline group drugs in pathological and normal conditions is studied using the example of three groups of laboratory rabbits. Group 1 - clinically healthy animals; group 2, group 3 - sick animals with experimentally induced pathology. Rabbits of the first and second groups were administered orally three times, with an interval of 8 hours, a tablet form of tetracycline at the rate of 25 mg/kg of body weight, rabbits of the third group were given 3% tetracycline 3 times a day for the lower eyelid. Animals' clinical examination included palpation of the examination, affected organs, and thermometry. Biological fluids (intraocular fluid and blood) were taken from the studied animals. The article presents the data of studies of tetracycline concentration, hematological parameters of blood serum, and biochemical parameters of blood serum of the studied animals. On the 9th day after the introduction of the Staphylococcus aureus suspension, clinical recovery occurred in all animals in the second and third groups, which was expressed by normalization of the animals' general condition, the number of respiratory movements, pulse rate, stabilization of body temperature was also within the limits. In the visual analyzer, the absence of inflammatory phenomena in the iris, cornea, and conjunctiva was observed in 2 animals of the second group. [ABSTRACT FROM AUTHOR]

Background: The use of plant extracts is a successful way to treat many diseases. Desert plants are rich in many antioxidant compounds, so they have been used since ancient times in folk medicine. The most important of these compounds are flavonoids that contain in their composition an aromatic ring and an oxidative hydroxyl group, which resists the free radical compounds formed in affected tissue and neutralize the tissue to reach the state of recovery. Objectives: The study aims to find an effective treatment to prevent tissue damage in burns or wounds in diabetic patients. Materials and methods: Two plants were used in this study; Haloxylon salicornicum and Zygophyllum coccineum (after proving their antioxidant activity by DPPH assay, with different concentrations for both plants). Flavonoids were extracted from them, and they were used to treat burns in laboratory rabbits with diabetes. The incidence of infection was confirmed by histological and hematological studies. Then, we studied of the effect of using the treatment on some blood variables, hormones and antioxidants during the treatment period for the stability of their effectiveness for treatment. Results: The study proved the effectiveness of these compounds by accelerating the treatment period despite diabetes and getting fast and effective results. Conclusion: Flavonoids of H. coccineum and Z. coccineum proved a high effectiveness of treatment compared to chemotherapy and accelerated the healing period of the wound. [ABSTRACT FROM AUTHOR]

Rabbit breeding is a very productive branch of animal husbandry that produces meat, hides, and down. Rabbit meat is a very valuable dietary product that is quickly absorbed by the human body and contains iron, many B vitamins, magnesium salts, phosphorus and other minerals, and is also rich in essential amino acids. One of the factors that leads to a decrease in the profitability of the rabbit breeding industry is parasitic diseases. Economic losses from infestations consist of loss of live weight and reduced fatness of rabbit carcasses, as well as deterioration of skin quality. The aim of the work was to investigate the distribution of associative infestations in rabbits in the Poltava region. The conducted research revealed the simplest organisms (Eimeria spp.), cestodes (Cysticercus pisiformis), nematodes (Passalurus ambiguus, Trichostrongylus sp.) and acariformes (Psoroptes cuniculi). The indicators of the extensivity of invasions in rabbits were for eimeriosis – 40.0 %, passalurosis – 29.64 %, cysticercosis pisiformis – 16.43 %, psoroptosis – 13.93 % and trichostrongylosis – 2.86 %. Parasitoses in rabbits was more often in the form of mixinvasions, where the rate of infestation reached 41.07 %. A total of 7 types of mixinvasions were registered, of which 5 are two-component associations of parasites, and 3 are three-component associations of parasites. Two-component mixinvasions were represented by the association of eimeries and passalurises (extensivity of invasion – 17.14 %), eimeries and cysticerces (7.86 %), eimeries and psoropteses (3.57 %), passalurises and cysticerces (6.07 %), passalurises and psoropteses (2.86 %). Three-component mixinvasions were characterized by the associative course of eimeries, passalurises and cysticerces (2.50 %) and eimeries, passalurises and psoropteses (1.07 %). The results of research on the associative course of parasitosis in rabbits indicate the need to use a complex of treatment and prevention measures in rabbit farms, taking into account the composition of parasites and their biological features. [ABSTRACT FROM AUTHOR]

Lagovirus europaeus GI.1 belongs to Lagovirus in the Caliciviridae family. GI.1 causes an acute, septic, and highly lethal disease in rabbits. Lagovirus europaeus GI.2, a new variant of GI.1, has caused explosive mortality in rabbits of all ages in Sichuan Province, China. To explore the differences in pathogenicity of rabbits infected with GI.1/GI.2, we investigated the virulence and disease progression of a naturally occurring GI.1/GI.2 in 4-week-old, 13-week-old, and 25-week-old New Zealand White laboratory rabbits after GI.1/GI.2 infection. Objective measures of disease progression were recorded using continuous body-temperature monitoring. We observed the kittens were infected with GI.2 during the most urgent course of the disease, and GI.1 was not lethal to kittens. We found that the target organ of both GI.1 and GI.2 was the liver, but the disease course of the two viruses was differed. Our study enriches the research on the pathogenicity of GI.1 and GI.2 under the same conditions. [ABSTRACT FROM AUTHOR]

To characterize the ongoing evolution of myxoma virus in Australian rabbits, we used experimental infections of laboratory rabbits to determine the virulence and disease phenotypes of recent virus isolates. The viruses, collected between 2012 and 2015, fell into three lineages, one of which, lineage c, experienced a punctuated increase in evolutionary rate. All viruses were capable of causing acute death with aspects of neutropenic septicemia, characterized by minimal signs of myxomatosis, the occurrence of pulmonary edema and bacteria invasions throughout internal organs, but with no inflammatory response. For the viruses of highest virulence all rabbits usually died at this point. In more attenuated viruses, some rabbits died acutely, while others developed an amyxomatous phenotype. Rabbits that survived for longer periods developed greatly swollen cutaneous tissues with very high virus titers. This was particularly true of lineage c viruses. Unexpectedly, we identified a line of laboratory rabbits with some innate resistance to myxomatosis and used these in direct comparisons with the fully susceptible rabbit line. Importantly, the same disease phenotype occurred in both susceptible and resistant rabbits, although virulence was shifted toward more attenuated grades in resistant animals. We propose that selection against inflammation at cutaneous sites prolongs virus replication and enhances transmission, leading to the amyxomatous phenotype. In some virus backgrounds this creates an immunosuppressive state that predisposes to high virulence and acute death. The alterations in disease pathogenesis, particularly the overwhelming bacterial invasions that characterize the modern viruses, suggest that their virulence grades are not directly comparable with earlier studies. IMPORTANCE The evolution of the myxoma virus (MYXV) following its release as a biological control for European rabbits in Australia is the textbook example of the coevolution of virus virulence and host resistance. However, most of our knowledge of MYXV evolution only covers the first few decades of its spread in Australia and often with little direct connection between how changes in virus phenotype relate to those in the underlying virus genotype. By conducting detailed experimental infections of recent isolates of MYXV in different lines of laboratory rabbits, we examined the ongoing evolution of MYXV disease phenotypes. Our results reveal a wide range of phenotypes, including an amyxomatous type, as well as the impact of invasive bacteria, that in part depended on the level of rabbit host resistance. These results provide a unique insight into the complex virus and host factors that combine to shape disease phenotype and viral evolution. [ABSTRACT FROM AUTHOR]

Background: Snakebite envenomation exerts a heavy toll in sub-Saharan Africa. The design and production of effective polyspecific antivenoms for this region demand a better understanding of the immunological characteristics of the different venoms from the most medically important snakes, to select the most appropriate venom combinations for generating antivenoms of wide neutralizing scope. Bitis spp. and Echis spp. represent the most important viperid snake genera in Africa. Methodology/Principal findings: Eight rabbit-derived monospecific antisera were raised against the venoms of four species of Bitis spp. and four species of Echis spp. The effects of immunization in the rabbits were assessed, as well as the development of antibody titers, as judged by immunochemical assays and neutralization of lethal, hemorrhagic, and in vitro coagulant effects. At the end of immunizations, local and pulmonary hemorrhage, together with slight increments in the plasma activity of creatine kinase (CK), were observed owing to the action of hemorrhagic and myotoxic venom components. Immunologic analyses revealed a considerable extent of cross-reactivity of monospecific antisera against heterologous venoms within each genus, although some antisera provided a more extensive cross-reactivity than others. The venoms that generated antisera with the broadest coverage were those of Bitis gabonica and B. rhinoceros within Bitis spp. and Echis leucogaster within Echis spp. Conclusions/Significance: The methodology followed in this study provides a rational basis for the selection of the best combination of venoms for generating antivenoms of high cross-reactivity against viperid venoms in sub-Saharan Africa. Results suggest that the venoms of B. gabonica, B. rhinoceros, and E. leucogaster generate antisera with the broadest cross-reactivity within their genera. These experimental results in rabbits need to be translated to large animals used in antivenom production to assess whether these predictions are reproduced in horses or sheep. Author summary: Snakebite envenomation exerts a heavy toll in sub-Saharan Africa. Antivenom is the only valid therapy for these envenomations. However, owing to the wide variety of snake species and the large variation in venom composition, the selection of the best combination of venoms to generate effective polyclonal antivenoms of wider neutralizing coverage is challenging. In this study, an experimental protocol was developed based on the generation of monospecific antisera in rabbits immunized with venoms of Bitis spp. or Echis spp. from Africa. Cross-reactivity of monospecific antisera was assessed by immunochemical analyses and by neutralization of toxic effects. Results revealed a large extent of intrageneric cross-reactivity by all antisera, with few exceptions. The venoms that generated antisera with the highest cross-reactivity and neutralizing ability among Bitis spp. were those of Bitis gabonica and B. rhinoceros, and of Echis leucogaster in Echis spp. These results provide evidence for the selection of the best combination of venoms for preparing antivenoms of high neutralizing scope within these two medically relevant genera of African viperid species. These results in rabbits must be translated to large animals used in antivenom production to assess whether these predictions are confirmed. [ABSTRACT FROM AUTHOR]

Introduction: Tramadol is an effective analgesic used in the treatment of mild to severe pains, but unregulated use may cause deleterious effects on the reproductive system of males. Objective: The objective of this study was to evaluate the effect of graded doses and duration of Tramadol on sperm indices and histomorphology of testes in male rabbits. Method: This is an experimental study of 24 male rabbits, divided into eight groups of three rabbits in each group. The rabbits were administered 10, 15, and 20 mg/kg daily doses of Tramadol intramuscularly for 15 and 30 days while F and G received intramuscular Tramadol of 10 and 20 mg/kg daily respectively for 15 days and were left to recover for 15 days. Group H received physiological saline only and served as the control group. Rabbits in each group were sacrificed and the caudal epididymis was excised from the rabbits for semen analysis. The left testes were removed for histological examinations. Results: The sperm motility, viability, and count were significantly lower (p<0.001), while sperm head abnormality was higher (p<0.001) with increasing concentrations and duration of Tramadol administration. There was no significant difference in semen pH. Upon withdrawal and recovery, sperm motility, viability, and count returned to near those of control rabbits. However, the differences in sperm head abnormality and semen pH were not significant compared with control rabbits. The germinal epithelium of the seminiferous tubules showed disturbance in the spermatogenic layers, with the reduced number of sperms and hypertrophic Leydig cells in the recovery Tramadol group, reduced number of Leydig cells and wide inter-tubular spaces in the chronic Tramadol group. Conclusion: The study indicated the harmful and damaging effects of Tramadol administration on the reproductive system of rabbits. It is suggested that the use of Tramadol should be regulated and dose monitored to prevent its deleterious effects on male fertility potential. [ABSTRACT FROM AUTHOR]

The use of rabbit hemorrhagic disease virus (RHDV) as a biocontrol agent to control feral rabbit populations in Australia, in combination with circulating endemic strains, provides a unique environment to observe the interactions between different lagoviruses competing for the same host. Following the arrival of RHDV2 (GI.2) in Australia, it became necessary to investigate the potential for immunological cross-protection between different variants, and the implications of this for biocontrol programs and vaccine development. Laboratory rabbits of various immune status—(1) rabbits with no detectable immunity against RHDV; (2) rabbits with experimentally acquired immunity after laboratory challenge; (3) rabbits immunised with a GI.2-specific or a multivalent RHDV inactivated virus prototype vaccine; or (4) rabbits with naturally acquired immunity—were challenged with one of three different RHDV variants (GI.1c, GI.1a or GI.2). The degree of cross-protection observed in immune rabbits was associated with the variant used for challenge, infectious dose of the virus and age, or time since acquisition of the immunity, at challenge. The immune status of feral rabbit populations should be determined prior to intentional RHDV release because of the high survival proportions in rabbits with pre-existing immunity. In addition, to protect domestic rabbits in Australia, a multivalent RHDV vaccine should be considered because of the limited cross-protection observed in rabbits given monovalent vaccines. [ABSTRACT FROM AUTHOR]

Aims: Worldwide, studies regarding antimicrobial resistance in rabbits are scarce. In addition, it seems that rearing conditions have important impact on emergence and spread of antimicrobial‐resistant bacteria. Thus, the authors sought to (1) assess the role of rabbits residing across diverse ecosystems as potential reservoirs of antimicrobial‐resistant enterococci and (2) investigate the genetic background of detected resistances. Methods and Results: Faecal samples from 60 healthy farmed rabbits (one farm), 35 laboratory rabbits and 31 wild rabbits were analysed. Overall, 97 enterococci isolates were accumulated, as follows: 44 E. faecium, 37 E. faecalis, 7 E. gallinarum, 5 E. durans and 4 E. avium. E. faecalis isolates were statistically associated with farm rabbits and wild rabbits (p < 0.05). High rates of resistance were observed for tetracycline (60.8%; tetM [n = 48; 81.3%], tetO [n = 7; 11.8%] and tetL [n = 1; 1.7%]), erythromycin (43.3%; msr(A) [n = 14; 33.3%] and ermB [n = 13; 31%]), ampicillin (29.9%), streptomycin (26.8%; ant(6)‐Ia [n = 3, 11.5%]) and vancomycin (21.6%; vanA [one E. faecium + one E. faecalis; 9.5%]). Low frequencies of resistance were observed for teicoplanin (9.2%), linezolid (8.2%), ciprofloxacin (7.2%) and gentamicin (1%; aac(6′)‐Ie‐aph(2″)‐Ia). Resistance to ampicillin and vancomycin was associated with laboratory rabbits (p < 0.05). Int‐Tn (Tn916/1545) was detected in 27 (27.8%) isolates, of which 10 isolates co‐harboured tetM and ermB genes, while 16 comprised tetM. Conclusion: Findings indicate that clinically relevant enterococci species isolated from rabbits are frequently resistant to antimicrobials and harbour a range of genes associated with the Tn916/1545 family. Significance and Impact of the study: This study highlights the high rates of antimicrobial‐resistant enterococci from rabbits and the occurrence of both vancomycin‐ and linezolid‐resistant isolates, potentially representing a very serious threat to human and animal health. [ABSTRACT FROM AUTHOR]

Clostridium perfringens (C. perfringens) is one of the most important pathogen that is widely distributed in all over the world and responsible for many diseases among life stock. C. perfringensis responsible for toxin production in the intestinal tract of rabbits and that was considered the main cause of enteritis and enterotoxaemia causing high mortality especially at the early weaned rabbits, which lead to high economic losses in rabbits industries. So, this study was aimed to evaluate the ability of oil adjuvant containing sonicated BCG vaccine to increase the immune response for rabbit clostridial enterotoxaemia and bloat vaccine. The study was conducted on twenty New Zealand rabbits divided in to two groups each of 10,Group A(control group)was vaccinated with alpha toxoid adjuvanted with aluminum hydroxide gel at two doses with 21 days apart inoculated subcutaneously, Group B was vaccinated with BCG sonicated oil adjuvant vaccine of alpha toxoid of C. perfringens type A, with 2 doses subcutaneously with 21 days. Rabbits in group (B) which vaccinated with BCG sonicated oil adjuvant vaccine of alpha toxoid of C. perfringens type A, their serum contain antibody titer of 8 IU/ml(7.1 IU-8.0 IU/ml) greater than that of control group (A) vaccinated with aluminum hydroxide gel adjuvant vaccine (W=0, p=0.0001503). From this study, we can concluded that the vaccination of rabbits with oil adjuvant containing sonicated BCG vaccine is effective to increase the immune response against rabbit clostridial enterotoxaemia and bloat vaccine. [ABSTRACT FROM AUTHOR]

Background and Objective: Tooth decay is the main cause of pulp and periapical diseases, and when the pulp involves the tooth, there is no other choice but to drain the pulp to save the tooth. The emergence of new methods of regenerative treatments has made it possible to restore dental pulp and dentin. Since regenerative treatments have been limited to immature teeth, this study was conducted to regenerate mature pulp tissue by dental pulp stem cell transplantation along with Platelet Rich Plasma (PRP) Matrix in rabbits. Methods: This experimental pilot study was conducted on a maxillary central incisor in a 1-year-old 2kg adult male albino rabbit. After completely cleaning the pulp tissue from the root and crown and washing the root canal, File #30 was passed through the apex to cause bleeding. Then dental pulp stem cells along with PRP were injected into the canal and the crown was sealed with glass ionomer cement. After 14 days, a radiograph was taken from the tooth, the extracted tooth was stained by hematoxylin-eosin and examined by light microscope. Findings: In the histological examination, in the inner wall of the root canal of odontoblasts, small thickness was observed in tubular dentin (about 1 mm) and pseudovascular structures. Furthermore, the entire space of the root canal was filled with a small and scattered number of inflammatory cells and pulp-like living tissue. Conclusion: Based on the results of this study, the observation of pseudovascular structures indicates the regenerative potential of dental pulp stem cells and opens a window for studies with more samples to effectively regenerate the dental pulp. [ABSTRACT FROM AUTHOR]

The aim of the present preclinical study was to investigate the capability of a new formulation of biphasic calcium phosphate (BCP) in achieving new bone formation either by itself or in combination with different concentrations of growth factors. Twentyfour 3-month-old male New Zealand white rabbits (weight range, 2.5 to 3.0 kg) that had been bred exclusively for biomedical research purposes and obtained from a licensed vendor were used. Four calvarial defects were created in each animal, for a total of 96 defects. Each defect received alloplastic BCP (Osteon III, Genoss) that was composed of 60% hydroxyapatite and 40% β-tricalcium phosphate) (porosity, ~80%; macropore size, 200 to 400 μm; crystallinity, 95%) combined with different concentrations of recombinant human platelet–derived growth factor BB (rhPDGF-BB), human recombinant basic fibroblast growth factor-2 (rhFGF-2), or recombinant human bone morphogenetic protein-2 (rhBMP-2). A custom-made polycarbonate tube was fixed to each defect site by applying slight pressure, and a mixture of bone graft and growth factor was implanted into the tubes. Data were collected 2, 4, and 8 weeks after creation of the defects to assess early and late healing. Various amounts of newly formed bone and remnant BCP particles formed inside of the tube throughout the study period. The BCP + 0.5 mg/mL rhBMP-2 group exhibited the most bone formation. At 8 weeks, more new bone formation was noted in the Osteon III + rhBMP-2 combined group than in other groups. The present study results indicate that BCP can be combined with different concentrations of rhBMP-2, rhFGF-2, and rhPDGF-BB to produce new bone formation within a polycarbonate tube in calvarial defects in a rabbit model. [ABSTRACT FROM AUTHOR]

In this study, it was aimed to obtain 3-dimensional (3D) digital and printed models of healthy forelimb joints using micro-computed tomography (µCT) technique in New Zealand Rabbit, which is frequently preferred in experimental orthopedic studies. Moreover, it was aimed to provide morphometric measurements on the shoulder and elbow joints over 3D digital models. A total of 14 adults (7 female, 7 male) New Zealand Rabbits were used in the study. After imaging the forelimbs with the µCT device, 3D digital and printed models were obtained. Biometric measurements of shoulder and elbow joints were performed over 3D digital models and the data obtained from female and male rabbits were evaluated statistically. The anatomical structure on the 3D joint models was very detailed due to the low section thickness and high detector quality. 3D printed models produced as a result of the 3D printing process were quite durable, odorless, and clean. No anatomical differences were observed between 3D printed models and 3D digital models. In this study, it is thought that the anatomical and morphometric data obtained from laboratory rabbits will contribute to scientists take part both in experimental orthopedic intervention and clinical anatomy education. [ABSTRACT FROM AUTHOR]

Successful rabbit production relies heavily on the use of adequate practices that enhance specific aspects of reproduction, such as mating, ovulation and lactation. Regardless of the type of production unit or strain of rabbits used, these processes rely on a complex chain of neuroendocrine steps that include particular hormones, peripheral stimuli and activation of discrete brain regions. Such is the case, for instance, of reflex ovulation, which occurs in response to copulation but is inhibited throughout lactation. Little is known about the mechanisms mediating lactational anoestrus and the restoration of oestrus following the cancellation of a single suckling episode (biostimulation). Nevertheless, the latter procedure (adopted worldwide to accelerate reproduction) has unwanted consequences for the doe and her litter. After successive episodes of biostimulation, the former shows a loss of fertility and body mass. In the kits, alterations are observed in their neuroendocrine response to mildly aversive stimulation in adulthood, as well as reductions in sexual behaviour. In addition to milk intake, a good nest is essential for normal litter growth and development. If this is not available, or if it deteriorates, rabbit caretakers can easily (re) build one from hair sheared off other rabbits or using synthetic material. Lactating does will nurse equally well their own or 'alien' young, placed inside the nest. It is crucial to have a minimum of six suckling kits in the nest, as the doe relies on this stimulation to maintain a normal nursing behaviour, i.e., only once a day throughout lactation. Recent work is revealing the similarities and differences in the responsiveness to mating among oestrous, lactating and biostimulated does. The relevance of these findings for the likelihood of reflex ovulation and the additional contribution of factors contained in the semen warrant more in-depth research. New insights on these issues, essential to reproductive neuroendocrinology, can emerge by fostering a richer interaction between academic laboratories and rabbit production settings worldwide. [ABSTRACT FROM AUTHOR]

Aim: The objective of this study was to characterize lactic acid bacteria (LAB) from rabbits to be used as potential autochthonous probiotic. Methods and Results: Fifteen faecal samples were collected from wild and laboratory rabbits. One hundred and eight isolates were collected and tested for their inhibitory power against eight pathogenic bacteria. Among them, 43 Enterococcus isolates were able to inhibit at least one pathogen. Enterocine genes entA, entB and entP were detected in 14, 17 and 22 isolates, respectively. These isolates were tested for their antibiotic susceptibility and genes encoding virulence factors. Relevant phenotypes of antibiotic resistance were observed especially for ampicillin, vancomycin and linezolid. The following virulence genes were detected (number of positive isolates): hyl (5), esp (8), gelE (30), agg (2), ace (21), efa (6), CylLL/s (5), cob (26), cpd (32) and ccf (33). Five isolates were considered as safe and showed tolerance to both acid and bile salt. Conclusion: Bacteriocinogenic enterococci isolates from rabbits may show relevant resistance phenotypes and virulence factors. In addition, one Enterococcus durans isolate presents promising autochthonous probiotic candidate. Significance and Impact of the study: This study reveals interesting properties for E. durans isolate and supports their utilization as autochthonous probiotic in rabbit husbandry. [ABSTRACT FROM AUTHOR]

Prevalence and age distribution of tumors is largely unknown in pet rabbits. Currently available studies focused on specific organ systems or specific tumor types and never covered a comparative examination of all tumor types. Previous studies on laboratory rabbits suggested a low tumor prevalence but were mostly limited to young adult animals. In the present study, all tumor types and several tumor-like lesions of all organ systems were analyzed retrospectively in archived pet rabbit samples of all ages. Cases included necropsy cases (n = 2,014) or postmortem tissue samples (n = 102) as well as surgical biopsies (n = 854). All lesions suspicious of neoplasia were reevaluated by histopathology and, when indicated, by immunohistochemistry. Necropsy cases had a tumor prevalence of 14.4% in both sexes or 19.8% in female intact rabbits of all age groups, and up to 47.2% or 66.7%, respectively, in rabbits older than 6 years. Overall, the most common tumor types were uterine adenocarcinoma (prevalence in female intact animals: 13.1%), lymphoma (prevalence: 2.8%), and thymoma (prevalence: 2.1%). Lymphoma, the most common tumor of rabbits ≤24 months of age, were of B-cell immunophenotype in 96% of cases and most commonly located in the lymph nodes (57%), gastrointestinal tract (54%), kidneys (48%), spleen (42%), and liver (41%). Tumors accounted for 81.1% of surgical biopsies and mostly comprised cutaneous, mammary, and uterine tumors. In conclusion, tumor types and prevalence varied significantly with respect to age, revealing some differences from previous studies on laboratory rabbits. [ABSTRACT FROM AUTHOR]

The objective in this study was to enhance osteogenic responses (in vitro and in vivo) to roughened titanium (Ti) dental implants through the formation of superhydrophilic TiO2 nanonetwork surface structure. Sandblasting and acid etching (SLA) was used to roughen the Ti surface. An electrochemical anodization process was then used to form a superhydrophilic TiO2 nanonetwork on the SLA Ti surfaces. The pore size of the nanonetwork structure ranged from a few nanometers to more than 100 nm, which is on the same scale as many biological species. Human bone marrow mesenchymal stem cells were used as an in vitro test model. The TiO2 nanonetwork structure was shown to have a significantly positive effect on hydrophilicity, protein adsorption, cell adhesion, cell migration, cell mineralization, and the gene and protein expression of osteogenic markers. The osseointegration of an anodized SLA screw-type Ti dental implant was investigated in vivo via implantation in the femur of New Zealand white rabbits for durations of 4 or 12 wk. The presence of a superhydrophilic surface TiO2 nanonetwork was shown to significantly enhance the bone-to-implant contact of the roughened SLA screw-type Ti dental implants. Overall, the proposed superhydrophilic TiO2 nanonetwork structure on the roughened SLA Ti surface proved highly effective in enhancing osteogenic responses in vitro and in vivo. [ABSTRACT FROM AUTHOR]

Objectives: Patients with acquired aplastic anemia (AA) without HLA‐matched sibling donors or aged >40 years receive immunosuppressive therapy (IST) with anti‐thymocyte globulin (ATG). We investigated the relationship between plasma rabbit ATG (r‐ATG) concentration and IST response. Methods: From May 2012 to October 2017, 81 patients with severe AA who required initial IST were included. A 1:1 block randomization was employed for 2.5 and 3.5 mg/kg doses of r‐ATG. Results: No significant difference in response rates was observed between the 2.5 and 3.5 mg/kg groups (63% vs. 58%, P =.894). Median r‐ATG concentrations on days 14 and 28 after IST were 15.2 (0.0‐97.7) and 1.8 (0.0‐74.9 µg/mL), respectively. According to r‐ATG concentration, response rates were significantly higher in the group with higher r‐ATG concentration than in those with lower r‐ATG concentration (day 14, 88% vs. 52%; P =.006 and day 28, 79% vs. 46%; P =.005). In multivariate analysis, higher r‐ATG concentrations at day 28 were independent predictors of favorable response to IST at 6 months (odds ratio, 0.29; 95% confidence interval, 0.09‐0.93; P =.037). Conclusions: The present data indicate that higher r‐ATG concentration at day 28 resulted in improved IST response. [ABSTRACT FROM AUTHOR]

The INHAND (International Harmonization of Nomenclature and Diagnostic Criteria for Lesions Project (www.toxpath.org/inhand. asp) is a joint initiative of the Societies of Toxicologic Pathology from Europe (ESTP), Great Britain (BSTP), Japan (JSTP) and North America (STP) to develop an internationally accepted nomenclature for proliferative and non-proliferative lesions in laboratory animals. The purpose of this publication is to provide a standardized nomenclature for classifying microscopic lesions observed in most tissues and organs from the laboratory rabbit used in nonclinical safety studies. Some of the lesions are illustrated by color photomicrographs. The standardized nomenclature presented in this document is also available electronically on the internet (http://www.goreni.org/). Sources of material included histopathology databases from government, academia, and industrial laboratories throughout the world. Content includes spontaneous lesions as well as lesions induced by exposure to test materials. Relevant infectious and parasitic lesions are included as well. A widely accepted and utilized international harmonization of nomenclature for lesions in laboratory animals will provide a common language among regulatory and scientific research organizations in different countries and increase and enrich international exchanges of information among toxicologists and pathologists. [ABSTRACT FROM AUTHOR]

Maternal high-fat diet in rabbits leads to hypertension and elevated renal sympathetic nerve activity (RSNA) in adult offspring but whether this is due to adiposity or maternal programming is unclear. We gave intracerebroventricular (ICV) and ventromedial hypothalamus (VMH) administration of leptin-receptor antagonist, α-melanocyte-stimulating hormone (αMSH), melanocortin-receptor antagonist (SHU9119), or insulin-receptor (InsR) antagonist to conscious adult offspring from mothers fed a high-fat diet (mHFD), control diet (mCD), or mCD offspring fed HFD for 10d (mCD10d, to deposit equivalent fat but not during development). mHFD and mCD10d rabbits had higher mean arterial pressure (MAP, +6.4 mmHg, +12.1 mmHg, p < 0.001) and RSNA (+2.3 nu, +3.2 nu, p < 0.01) than mCD, but all had similar plasma leptin. VMH leptin-receptor antagonist reduced MAP (−8.0 ± 3.0 mmHg, p < 0.001) in mCD10d but not in mHFD or mCD group. Intracerebroventricular leptin-receptor antagonist reduced MAP only in mHFD rabbits (p < 0.05). Intracerebroventricular SHU9119 reduced MAP and RSNA in mHFD but only reduced MAP in the mCD10d group. VMH αMSH increased RSNA (+85%, p < 0.001) in mHFD rabbits but ICV αMSH increased RSNA in both mHFD and mCD10d rabbits (+45%, +51%, respectively, p < 0.001). The InsR antagonist had no effect by either route on MAP or RSNA. Hypothalamic leptin receptor and brain-derived neurotrophic factor (BDNF) mRNA were greater in mHFD compared with mCD rabbits and mCD10d rabbits. In conclusion, the higher MAP in mHFD and mCD10d offspring was likely due to greater central leptin signaling at distinct sites within the hypothalamus while enhanced melanocortin contribution was common to both groups suggesting that residual body fat was mainly responsible. However, the effects of SHU9119 and αMSH on RSNA pathways only in mHFD suggest a maternal HFD may program sympatho-excitatory capacity in these offspring and that this may involve increased leptin receptor and BDNF expression. [ABSTRACT FROM AUTHOR]

Notoedric mange, caused by sarcoptiform Notoedres mites, an obligately parasite, causes potentially fatal dermatitis along with secondary systemic infections in small mammals, felids as well as humans. In the present case study, we describe clinical diagnosis and therapeutic management of notoedric mange with ivermectin in rabbits. Two New Zealand White rabbits (Oryctolagus cuniculus) naturally infested with notoedric mange reported with history of varied clinical signs like anorexia, patchy alopecia, intense pruritus, erythema and dry scabs. Several whitish crust-like lesions were observed on ears, nose, face, forelimbs and hindlimbs. Confirmatory diagnosis of Notoedres cati var cuniculi was done by skin scraping from supported by clinical signs and hematological alterations. Both the animals were successfully treated with Ivermectin, a broad spectrum anti-parasitic agent. Both rabbits showed recovery by the end of third week of treatment and it was subsequently confirmed by absence of mites in two consecutive skin scrapings examination at weekly interval. The mite, Notoedres cati is considered as a serious pest of rabbits with ivermectin as still effective drug in treating the clinical cases. Stringent diagnostic strategies need to be prepared for regular screening and control of notoedric infestations in laboratory and pet rabbits. [ABSTRACT FROM AUTHOR]

Cerebral dominancy is well known on laterality; however, histological analysis of vertebral artery dominance has not been adequately studied. It was aimed to investigate the relationship between the dominant vertebral artery and hand preference. In this study, which fifteen male rabbits were examined, paw preference was evaluated with a food-reaching test. Vertebral artery samples just entering to the cranium were obtained from right- and left-pawed rabbits to evaluate luminal surface values histologically. Handedness preferences and vertebral arteries lumen surface values were compared statistically using the Mann-Whitney U test. As a result of the measurements made, the vertebral artery on the side with a larger diameter was accepted as dominant. The larger lumen surface values were found in the left vertebral artery than in the right vertebral artery in right-handed rabbits and vice versa. The mean lumen surface values of the left/right vertebral arteries were 0.395±0.068 / 0.305±0.034 mm2 in the rightpawed animals (p<0.0001); 0.298±0.032 / 0,364±0.049 mm2 in the left-pawed animals (p<0.001) and 0.389±0.061 / 0.354±0.054 mm2 both pawed animals (p<0.001). The vertebral artery was accepted to be dominant when there were different arterial lumen diameters from side to side. Arterial luminal diameter was dominant in 53% of the cases on the left and in 33% on the right. Left and right arterial lumen diameters were equal in 13% of cases. As a conclusion, it was found that, vertebral artery dominancy may have predictive roles in the determination of handedness. [ABSTRACT FROM AUTHOR]

The aims of this study were to evaluate the feasibility of the New Zealand White (NZW) rabbit for studying implanted biomaterials in pelvic reconstructive surgery; and to compare the occurrence of graft-related complications of a commercial polypropylene (PP) mesh and new developed human dermal matrix implanted at vaginal and abdominal level. 20 white female NZW rabbits were randomized into two groups, experimental group (human acellular dermal matrices-hADM-graft) and control group (commercial PP graft). In each animal, grafts were surgically implanted subcutaneously in the abdominal wall and in the vaginal submucosa layer for 180 days. The graft segments were then removed and the surgical and clinical results were analyzed. The main surgical challenges during graft implantation were: (a) an adequate vaginal exposure while maintaining the integrity of the vaginal mucosa layer; (b) to keep aseptic conditions; (c) to locate and dissect the breast vein abdominal surgery; and (d) to withdraw blood samples from the ear artery. The most abnormal findings during the explant surgery were found in the PP group (33% of vaginal mesh extrusion) in comparison with the hADM group (0% of vaginal graft extrusion), p = 0.015. Interestingly, macroscopic observation showed that the integration of the vaginal grafts was more common in the hADM group (40%) than in the PP group, in which the vaginal mesh was identified in 100% of the animals (p = 0.014). The NZW rabbit is a good model for assessing materials to be used as grafts for pelvic reconstructive surgery and vaginal surgery. Animals are easily managed during the procedures, including surgical intervention and vaginal mucosa approach. Additionally, hADM is associated with fewer clinical complications, as well as better macroscopic tissue integration, compared to PP mesh. [ABSTRACT FROM AUTHOR]