Unraveling the role of Xist in X chromosome inactivation: insights from rabbit model and deletion analysis of exons and repeat A.

X chromosome inactivation (XCI) is a process that equalizes the expression of X-linked genes between males and females. It relies on Xist, continuously expressed in somatic cells during XCI maintenance. However, how Xist impacts XCI maintenance and its functional motifs remain unclear. In this study, we conducted a comprehensive analysis of Xist, using rabbits as an ideal non-primate model. Homozygous knockout of exon 1, exon 6, and repeat A in female rabbits resulted in embryonic lethality. However, X∆ReAX females, with intact X chromosome expressing Xist, showed no abnormalities. Interestingly, there were no significant differences between females with homozygous knockout of exons 2-5 and wild-type rabbits, suggesting that exons 2, 3, 4, and 5 are less important for XCI. These findings provide evolutionary insights into Xist function.

Multispecies comparative prostate anatomy by imaging: Implications for experimental models of prostatic disease.

BACKGROUND: There is an increasing interest in using preclinical models for development and assessment of medical devices and imaging techniques for prostatic disease care. Still, a comprehensive assessment of the prostate's radiological anatomy in primary preclinical models such as dogs, rabbits, and mice utilizing human anatomy as a reference point remains necessary with no optimal model for each purpose being clearly defined in the literature. Therefore, this study compares the anatomical characteristics of different animal models to the human prostatic gland from the imaging perspective. METHODS: We imaged five Beagle laboratory dogs, five New Zealand White rabbits, and five mice, all sexually mature males, under Institutional Animal Care and Use Committee (IACUC) approval. Ultrasonography (US) was performed using the Vevo® F2 for mice (57 MHz probe). Rabbits and dogs were imaged using the Siemens® Acuson S3000 (17 MHz probe) and endocavitary (8 MHz) probes, respectively. Magnetic resonance imaging (MRI) was also conducted with a 7T scanner in mice and 3T scanner in rabbits and dogs. RESULTS: Canine transrectal US emerged as the optimal method for US imaging, depicting a morphologically similar gland to humans but lacking echoic zonal differentiation. MRI findings in canines indicated a homogeneously structured gland similar to the human peripheral zone on T2-weighted images (T2W) and apparent diffusion coefficient (ADC). In rabbits, US imaging faced challenges due to the pubic symphysis, whereas MRI effectively visualized all structures with the prostate presenting a similar aspect to the human peripheral gland on T2W and ADC maps. Murine prostate assessment revealed poor visualization of the prostate glands in ultrasound due to its small size, while 7T MRI delineated the distinct prostates and its lobes, with the lateral and dorsal prostate resembling the peripheral zone and the anterior prostate the central zone of the human gland. CONCLUSION: Dogs stand out as superior models for advanced preclinical studies in prostatic disease research. However, mice present as a good model for early stage studies and rabbits are a cost-effective alternative and serve as valuable tools in specific research domains when canine research is not feasible.

Development of rabbit models of ventilator-associated bacterial pneumonia produced by carbapenem-resistant Pseudomonas aeruginosa.

Ventilator-associated bacterial pneumonia (VABP) is among the most intractable of carbapenem-resistant Gram-negative bacterial infections. New antimicrobial agents are critically needed for the treatment of VABP. However, current conventionally used animal model systems are inadequate to meet this challenge. We, therefore, developed rabbit models of VABP caused by carbapenem-resistant Pseudomonas aeruginosa. Persistently neutropenic New Zealand White rabbits were used throughout the study. The early-phase intubated model (0-24 h) received mechanical ventilation, while the late-phase intubated model (72-96 h) was ambulatory. The following outcome parameters were studied: survival, residual tissue bacterial burden (CFU/g), residual BAL bacterial burden (CFU/mL), lung weights, pulmonary lesion score, histology, O2 saturation, radiographic imaging, and histology. Each anesthetized rabbit received a predetermined endotracheal bacterial inoculum, and ventilators were set to FiO2 = 40% and PEEP = 8 mmHg. Within the first 12 h post-inoculation, mean bacterial burdens in lung tissue and BAL fluid, respectively, were established at approximately 107 CFU/g and 106 CFU/mL, persisted through 24 h in the early-phase model and increased in the late-phase model to approximately 108 CFU/g and 107 CFU/mL. Mean max SpO2 was ≥98 mmHg, and mean nadir SpO2 was ≥68 mmHg. Serial thoracic radiographs demonstrated progressive multilobar pneumonic infiltrates. Lung histology revealed progressive focal bronchopneumonia, coagulative necrosis, intra-alveolar hemorrhage, alveolar epithelial cell necrosis, and bacterial microcolonies. The new rabbit model of VABP produced by carbapenem-resistant Pseudomonas aeruginosa recapitulates the pathophysiological, microbiological, diagnostic imaging, and histological patterns of human disease by which to assess critically needed new antimicrobial agents against this lethal infection.

4D label-free quantitative proteomic analysis identifies CRABP1 as a novel candidate gene for litter size in rabbits†.

In commercial rabbit breeding, litter size is a crucial reproductive trait. This trait directly determines the reproductive ability of female rabbits and is crucial for evaluating the production efficiency. We here compared differentially expressed proteins of in the ovary tissue from New Zealand female rabbits with high (H) and low (L) litter sizes by using 4D label-free quantitative proteomic technology and identified 92 differential proteins. The biological functions of these proteins were revealed through gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Most distributions of GO and KEGG were related to reproduction, growth development, and metabolism. Furthermore, a novel candidate gene cellular retinoic acid binding protein-1 (CRABP1), which was highly expressed in the L group, was selected for further biological function verification. The Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis revealed that CRABP1 can promote granulosa cell (GC) apoptosis and inhibit GC proliferation. Furthermore, qRT-PCR and western blotting analysis revealed that CRABP1 regulates the genes (HSD17B1, Wnt-10b, FSHR, TAF4B, BMP15, and BMP6) and protein (Wnt-10b) associated with steroid hormone synthesis and follicle development. The PCR product direct sequencing method revealed single nucleotide polymorphisms in the core promoter region of CRABP1. Luciferase activity assays revealed that the transcriptional activity of the GG genotype was significantly higher than that of the TT or TG genotype. Different genotypes are accompanied by changes in transcription factors, which indicates that T-359G polymorphism can regulate CRABP1 expression. In general, we identified litter size-related genes and revealed the mechanism underlying the effect of CRABP1 on litter size. CRABP1 serves as a key factor in the reproductive capacity of rabbits and can act as a molecular biomarker for the breeding of New Zealand rabbits.

Ethyl pyruvate alleviates pulmonary arterial hypertension via PI3K-Akt signaling.

Pulmonary arterial hypertension (PAH) is a pathophysiological syndrome that is extremely difficult to manage, and there is currently no effective treatment. We want to elucidate the therapeutic effect of ethyl pyruvate (EP) on PAH and its possible mechanism. Pulmonary artery endothelial cells (PAECs) were cultured in conventional low-oxygen environments, and cellular proliferation was monitored after treatment with EP. Expression of p-PI3K/Akt, LC3-II, and Beclin-1 was detected by Western blot. After hyperkinetic PAH rabbits' models were treated with EP, hemodynamic data were collected. Right ventricular hypertrophy and pulmonary vascular remodeling were evaluated. Expression of p-PI3K/Akt, LC3-II, and Beclin-1 protein was also detected after using autophagy inhibitor and agonists. We found that EP could inhibit PAECs proliferation. After EP treatment, expression of p-PI3K/Akt was upregulated in vitro and in vivo. LC3-II and Beclin-1 were inhibited and their expression was lower after autophagy inhibitor was given, while after administration of autophagy agonists, their expression was higher than that in the EP alone group. Besides, EP attenuated PAH, and right ventricular hypertrophy and pulmonary vascular remodeling were also reversed. EP can reduce PAH and reverse vascular remodeling which is associated with inhibition of autophagy in PAECs based on PI3K-Akt signaling pathway. The results of this study can provide surgical opportunities for patients with severe PAH caused by congenital heart disease in clinical cardiovascular surgery.

Assessment of early anthracycline-induced cardiotoxicity and liver injury with T2 and T2* mapping in rabbit models.

OBJECTIVES: To evaluate the early prevalence of anthracycline-induced cardiotoxicity (AIC) and anthracycline-induced liver injury (AILI) using T2 and T2* mapping and to explore their correlations. MATERIALS AND METHODS: The study included 17 cardiotoxic rabbits that received weekly injections of doxorubicin and magnetic resonance imaging (MRI) every 2 weeks for 10 weeks. Cardiac function and T2 and T2* values were measured on each period. Histopathological examinations for two to five rabbits were performed after each MRI scan. The earliest sensitive time and the threshold of MRI parameters for detecting AIC and AILI based on these MRI parameters were obtained. Moreover, the relationship between myocardial and liver damage was assessed. RESULTS: Early AIC could be detected by T2 mapping as early as the second week and focused on the 7th, 11th, and 12th segments of left ventricle. The cutoff value of 46.64 for the 7th segment had the best diagnostic value, with an area under the curve (of 0.767, sensitivity of 100%, and specificity of 52%. T2* mapping could detect the change in iron content for early AIC at the middle interventricular septum and AILI as early as the sixth week (p = 0.014, p = 0.027). The T2* values of the middle interventricular septum showed a significant positive association with the T2* values of the liver (r = 0.39, p = 0.002). CONCLUSION: T2 and T2* mapping showed value one-stop assessment of AIC and AILI and could obtain the earliest MRI diagnosis point and optimal parameter thresholds for these conditions. CLINICAL RELEVANCE STATEMENT: Anthracycline-induced cardiotoxicity could be detected by T2 mapping as earlier as the second week, mainly focusing on the 7th, 11th, and 12th segments of left ventricle. Combined with T2* mapping, hepatoxicity and supplementary cardiotoxicity were assessed by one-stop scan. KEY POINTS: • MRI screening time of cardiotoxicity was as early as the second week with focusing on T2 values of the 7th, 11th, and 12th segments of left ventricle. • T2* mapping could be used as a complement to T2 mapping to evaluate cardiotoxicity and as an effective index to detect iron change in the early stages of chemotherapy. • The T2* values of the middle interventricular septum showed a significant positive association with the T2* values of the liver, indicating that iron content in the liver and heart increased with an increase in the chemotherapeutic drugs.

Morphological and molecular characterization of Eimeria magna infecting local rabbit (Oryctolagus cuniculus) in Alkarg City, Saudi Arabia.

Coccidiosis is one of the most prevalent diseases found in local rabbits (Oryctolagus cuniculus), which is caused by the Eimeria. The study aimed to more reliably identify Eimeria species (Eimeria magna) infecting Local Rabbits in Alkarg City, Saudi Arabia, based the method on the molecular properties and morphological and molecular biological techniques. Sub-spheroidal oocysts measuring 21-27 × 12-16 (24 × 14.4) µm (20 n) and with a length/width (L/W) ratio of 0.9-1.1 (1.0) were identified by microscopic analysis of a fecal sample. Oocysts feature a bi-layered wall that is 1.0-1.2 (1.1) µm thick. About two-thirds of the wall's thickness is made up of a smooth outer layer. A polar granule is present, but neither a micropyle nor an oocyst residuum is present. The ovoidal sporozoites measure 15-18 × 8-11 (16.5 × 9.5) µm, have an L/W ratio of 1.6-1.8 (1.7), and take up around 21% of the oocyst's total surface. The mean size of the sub-Stieda body is 1.4 × 2.3 µm, while the average size of the Stieda body is 0.9 × 1.8 µm. The para-Stieda body is lacking. Sporocyst residuum appears membrane-bound and has an uneven form made up of several granules. With two refractile bodies below the striations and pronounced striations at the more pointed end, sporozoites are vermiform, measuring an average of 11.6 × 4.0 µm. The results of the sequencing for the 18S rDNA gene confirmed the species of Eimeria parasites found in the host (rabbits). The current parasite species is closely related to the previously described and deposited E. magna and deeply embedded in the genus Eimeria (family Eimeriidae). According to the findings, single oocyst molecular identification of Eimeria may be accomplished through consistent use of the morphological and molecular results. It is possible to draw the conclusion that the current research supplies relevant facts that help assess the potential infection and future control measures against rabbit coccidiosis to reduce the financial losses that can be incurred by the rabbit industry in Saudi Arabia.

Lp-PLA2 (Lipoprotein-Associated Phospholipase A2) Deficiency Lowers Cholesterol Levels and Protects Against Atherosclerosis in Rabbits.

BACKGROUND: Elevated plasma Lp-PLA2 (lipoprotein-associated phospholipase A2) activity is closely associated with an increased risk of cardiovascular events. However, whether and how Lp-PLA2 is directly involved in the pathogenesis of atherosclerosis is still unclear. To examine the hypothesis that Lp-PLA2 could be a potential preventative target of atherosclerosis, we generated Lp-PLA2 knockout rabbits and investigated the pathophysiological functions of Lp-PLA2. METHODS: Lp-PLA2 knockout rabbits were generated using CRISPR/Cas9 system to assess the role of Lp-PLA2 in plasma lipids regulation and identify its underlying molecular mechanisms. Homozygous knockout rabbits along with wild-type rabbits were fed a cholesterol-rich diet for up to 14 weeks and their atherosclerotic lesions were compared. Moreover, the effects of Lp-PLA2 deficiency on the key cellular behaviors in atherosclerosis were assessed in vitro. RESULTS: When rabbits were fed a standard diet, Lp-PLA2 deficiency led to a significant reduction in plasma lipids. The decreased protein levels of SREBP2 (sterol regulatory element-binding protein 2) and HMGCR (3-hydroxy-3-methylglutaryl coenzyme A reductase) in livers of homozygous knockout rabbits indicated that the cholesterol biosynthetic pathway was impaired with Lp-PLA2 deficiency. In vitro experiments further demonstrated that intracellular Lp-PLA2 efficiently enhanced SREBP2-related cholesterol biosynthesis signaling independently of INSIGs (insulin-induced genes). When fed a cholesterol-rich diet, homozygous knockout rabbits exhibited consistently lower level of hypercholesterolemia, and their aortic atherosclerosis lesions were significantly reduced by 60.2% compared with those of wild-type rabbits. The lesions of homozygous knockout rabbits were characterized by reduced macrophages and the expression of inflammatory cytokines. Macrophages of homozygous knockout rabbits were insensitive to M1 polarization and showed reduced DiI-labeled lipoprotein uptake capacity compared with wild-type macrophages. Lp-PLA2 deficiency also inhibited the adhesion between monocytes and endothelial cells. CONCLUSIONS: These results demonstrate that Lp-PLA2 plays a causal role in regulating blood lipid homeostasis and Lp-PLA2 deficiency protects against dietary cholesterol-induced atherosclerosis in rabbits. Lp-PLA2 could be a potential target for the prevention of atherosclerosis.

Impairment of Angiogenesis-Driven Clot Resolution Is a Key Event in the Progression to Chronic Thromboembolic Pulmonary Hypertension: Validation in a Novel Rabbit Model.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening condition and rare complication of acute pulmonary embolism. Mechanisms underlying impaired clot resolution and in sustained fibrothrombotic obstruction of the pulmonary arterial bed remain poorly understood. Since defective angiogenesis correlated to defective clot resolution based on observations in surgical material from patients with CTEPH, we aimed to validate its crucial pathogenic role by intrathrombus inhibition of angiogenesis in a novel CTEPH rabbit model. METHODS: We aimed to compare whether intrathrombus administration of an antifibrinolytic agent, tranexamic acid, or an inhibitor of angiogenesis, SU5416, would contribute to CTEPH progression. Both products were administered on a weekly basis by autologous clot embolization in rabbits. Right ventricular pressure was monitored by telemetry, right ventricular function by transthoracic echocardiography, and a complete pulmonary hemodynamic evaluation was obtained through right heart catheterization. Markers of inflammation, endothelial dysfunction, heart failure, and fibrinolysis were measured in plasma. Pulmonary vessel remodeling was analyzed by immunohistochemistry. RESULTS: Impairing intrathrombus angiogenesis by repeatedly embolizing autologous blood clots containing SU5416 resulted in elevated mean pulmonary arterial pressure (38 mm Hg), increased indexed pulmonary vascular resistance, and enhanced right ventricular hypertrophy (80%, 1.9-fold, 36%, respectively, compared with rabbits embolized with clots containing an antifibrinolytic agent). This was caused by both obstruction of large pulmonary arteries with fibrothrombotic material and muscularization of pulmonary microvessels, and accompanied by inflammatory cell infiltration and increased circulating endothelin-1. CONCLUSIONS: The key role of angiogenesis-driven clot resolution was validated in a reliable small-animal model reproducing the major pathophysiological hallmarks of CTEPH.

Comparative analysis of two novel complete genomes of myxoma virus vaccine strains.

Myxoma virus (MYXV) is a double-stranded DNA-containing virus of the family Poxviridae, genus Leporipoxvirus. MYXV is an important model virus for evolutionary and immunological research and a promising oncolytic. In this study, we sequenced and analyzed two complete genomes of MYXV virus vaccine strains B-82 and Rabbivac-B, which are widely used for vaccine production in Russia. Here, we first show that MYXV vaccine strains B-82 and Rabbivac-B share a common origin with the American recombinant MYXV MAV vaccine strain. In addition, our data suggest that the MYXV B-82 and Rabbivac-B strains contain a number of genes at the 5' and 3' ends that are identical to the virulent MYXV Lausanne strain. Several unique genetic signatures were identified in the M013L, M017L, M023, and M121R genes, helping to achieve high genetic resolution between vaccine strains. Overall, these findings highlight the evolutionary flexibility of certain genes in the MYXV genome and provide insights into the molecular epidemiology of the virus and subsequent vaccine development.

Effects of JUNCAO Ganoderma lucidum polysaccharide peptide on slaughter performance and intestinal health of Minxinan black rabbits.

This experiment was conducted to investigate the effects of JUNCAO Ganoderma lucidum polysaccharide peptide (JCGLPP) on slaughter performance and intestinal health of Minxinan black rabbits, which aimed to provide the basis for the application of JCGLPP in meat rabbits. One hundred male weaned Minxinan black rabbits of (33 ± 2) d [(initial body mass (655.65 ± 25.90) g] were randomly divided into four groups with five replicates per group and five rabbits per replicate. The diets were supplemented with 0 (control group), 50 (group I), 100 (group II) and 150 mg·kg-1 (group III) of JCGLPP, respectively. This experiment lasted for 56 days. The results are shown below: (1) The live weight before slaughter of groups I and III was significantly higher than that of control group (p < 0.05); The full net bore weight of group III was significantly higher than that of control group (p < 0.05). (2) pH value of group I was significantly higher than that of control group (p < 0.05); NH3-N content in experimental groups were significantly higher than that in control group(p < 0.05) while NH3-N content in group I was significantly higher than that in groups III and II (p < 0.05); The content of butyric acid in group II was significantly lower than that in control group (p < 0.05); There were no significant differences in acetic acid, isovaleric acid, isobutyric acid and propionic acid in experimental groups compared with control group (p > 0.05). (3) The Occludin content in duodenum, jejunum and ileum of groups I and II was significantly higher than that of control group (p < 0.05). (4) At the phylum level, Firmicutes and Bacteroidetes were the dominant phylum in each group. At the genus level, norank_f__norank_o__Clostridia_UCG-014 in group II were significantly higher than those in control group (p < 0.05). In conclusion, although dietary JCGLPP supplementation could not improve slaughter performance of Minxinan black rabbits, it could improve cecal fermentation parameters and intestinal flora structure and composition of Minxinan black rabbits to a certain extent. Our results revealed that 100 mg·kg-1 might be the optimal concentration obtained in dietary JCGLPP supplementation, which provided ideas and feasibility for drug combination.

Pulmonary Transit Time Assessment by CEUS in Healthy Rabbits: Feasibility, and the Effects of UCAs Dilution Concentration.

To evaluate the inter-observer variability and the intra-observer repeatability of pulmonary transit time (PTT) measurement using contrast-enhanced ultrasound (CEUS) in healthy rabbits, and assess the effects of dilution concentration of ultrasound contrast agents (UCAs) on PTT. Thirteen healthy rabbits were selected, and five concentrations UCAs of 1:200, 1:100, 1:50, 1:10, and 1:1 were injected into the right ear vein. Five digital loops were obtained from the apical 4-chamber view. Four sonographers obtained PTT by plotting the TIC of right atrium (RA) and left atrium (LA) at two time points (T1 and T2). The frame counts of the first appearance of UCAs in RA and LA had excellent inter-observer agreement, with intra-class correlations (ICC) of 0.996, 0.988, respectively. The agreement of PTT among four observers was all good at five different concentrations, with an ICC of 0.758-0.873. The reproducibility of PTT obtained by four observers at T1 and T2 was performed well, with ICC of 0.888-0.961. The median inter-observer variability across 13 rabbits was 6.5% and the median variability within 14 days for 4 observers was 1.9%, 1.7%, 2.2%, 1.9%, respectively; The PTT of 13 healthy rabbits is 1.01 ± 0.18 second. The difference of PTT between five concentrations is statistically significant. The PTT obtained by a concentration of 1:200 and 1:100 were higher than that of 1:1, while there were no significantly differences in PTT of a concentration of 1:1, 1:10, and 1:50. PTT measured by CEUS in rabbits is feasible, with excellent inter-observer and intra-observer reliability and reproducibility, and dilution concentration of UCAs influences PTT results.

Comparison of Different Suture Techniques on Nasal Soft Tissue Envelope to Prevent Supratip Deformity: A Histologic Study.

BACKGROUND: Studies have described various surgical maneuvers in rhinoplasty to limit thickening from excessive scarring in the supratip region. This study aimed to compare the effectiveness of three maneuvers-a simple suture, a U suture, and bolster dressing-used to avoid supratip deformity in a rabbit model. METHODS: Thirty-two male New Zealand white rabbits were included. The animals were divided into four groups, and dissection was performed in the supra-perichondrial plane up to the supratip region through an open rhinoplasty incision. After dissection, the following approaches were applied to the supratip region: Group 1, simple approximation suture; Group 2, U suture; Group 3, bolster dressing; and Group 4 (control group), no suture. All animals were sacrificed after 12 weeks. Histological analysis was performed. RESULTS: In Group 4, scar thickness was significantly greater than in the other groups (p < 0.05). Group 3 had greater scar thickness than Group 2 (p < 0.05). The ratio of scar thickness to skin thickness was higher in Group 4 compared with the other groups (p < 0.05). Finally, there was no difference in the ratio of scar thickness to skin thickness between Groups 1, 2, and 3 (p > 0.05). CONCLUSIONS: In this study, it was concluded that surgical methods using sutures in the supratip region reduced scar thickness in a rabbit model, and these surgical methods had similar levels of effectiveness. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of Polypropylene and Polydioxanone in the Hemitransdomal Suture: A Novel Rabbit Ear Cartilage Model.

BACKGROUND: Lower lateral cartilage reshaping is one of the basic steps in rhinoplasty. Hemitransdomal suture is frequently used for dome narrowing. Different suture materials can be used for hemitransdomal suture. In this study, we investigated the effectiveness of polypropylene and polydioxanone in hemitransdomal suture by designing a new experimental model in the rabbit ear cartilage. METHODS: Twelve young adult male New Zealand White rabbits were used. The bipedicled inverted-U-shaped cartilage was elevated in each ear of the rabbits. Two hemitransdomal sutures were applied using 5-0 polypropylene on one ear and 5-0 polydioxanone on the other ear randomly. A 5 mm high cartilage mound was created with two hemitransdomal sutures on each side. The sample size was twelve both in the polypropylene group and the polydioxanone group (n = 12). All animals were sacrificed after three months. Cartilage mound heights were measured. The samples were examined histologically regarding fibroadipose tissue, inflammation, foreign body granuloma, cartilage degeneration, and the presence of inclusion cyst. RESULTS: Cartilage mound height was significantly higher in the polypropylene group than in the polydioxanone group at the end of the third month [3.75 mm (± 0.68) vs. 3.03 mm (± 0.69); p < 0.05]. There was no significant difference between the two groups in histological analysis (p > 0.05). CONCLUSIONS: Polypropylene suture may be more effective in maintaining the shape given to the dome by hemitransdomal sutures in rhinoplasty. No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266.

Integration Analysis of Hair Follicle Transcriptome and Proteome Reveals the Mechanisms Regulating Wool Fiber Diameter in Angora Rabbits.

Fiber diameter is an important characteristic that determines the quality and economic value of rabbit wool. This study aimed to investigate the genetic determinants of wool fiber diameter through an integration analysis using transcriptomic and proteomic datasets from hair follicles of coarse and fine wool from Angora rabbits. Using a 4D label-free technique, we identified 423 differentially expressed proteins (DEPs) in hair follicles of coarse and fine wool in Angora rabbits. Eighteen DEPs were examined using parallel reaction monitoring, which verified the reliability of our proteomic data. Functional enrichment analysis revealed that a set of biological processes and signaling pathways related to wool growth and hair diameter were strongly enriched by DEPs with fold changes greater than two, such as keratinocyte differentiation, skin development, epidermal and epithelial cell differentiation, epidermis and epithelium development, keratinization, and estrogen signaling pathway. Association analysis and protein-protein interaction network analysis further showed that the keratin (KRT) family members, including KRT77, KRT82, KRT72, KRT32, and KRT10, as well as CASP14 and CDSN, might be key factors contributing to differences in fiber diameter. Our results identified DEPs in hair follicles of coarse and fine wool and promoted understanding of the molecular mechanisms underlying wool fiber diameter variation among Angora rabbits.

Apoptotic Cell Death in an Animal Model of Virus-Induced Acute Liver Failure-Observations during Lagovirus europaeus/GI.2 Infection.

Lagovirus europaeus/GI.2 causes severe and highly fatal Rabbit Hemorrhagic Disease (RHD). Because of its characteristics, this infection is used as an animal model for acute liver failure (ALF). Apoptosis is one of the key processes underlying ALF and has been described as one of the mechanisms of RHD pathogenesis. Apoptotic cell death has been quite well characterized in infection with different variants of GI.1 strains, but so far, the GI.2 genotype has not been widely studied. In this study, we performed an evaluation of apoptotic cell death in hepatocytes of rabbits infected with Lagovirus europaeus/GI.2. We analyzed the expression of genes involved in apoptotic cell death by real-time PCR and performed immunohistochemical (IHC) assays. We showed a significant increase in the expression of caspase-3 and the proapoptotic Bax and anti-apoptotic Bcl-2 in infected animals. In addition, we recorded increased Bax/Bcl-2 ratios. IHC analyses showed the presence of morphological signs of apoptosis in the hepatocytes of infected rabbits. Our results indicate that caspase-3 and proteins from the Bcl-2 families play a key role in apoptosis induced by Lagovirus europaeus/GI.2 infection.

Ultrasound-mediated HGF Gene Microbubbles Mitigate Hyperkinetic Pulmonary Arterial Hypertension in Rabbits.

AIM: Hyperkinetic pulmonary arterial hypertension (PAH) is a complication of congenital heart disease. Gene therapy is a new experimental treatment for PAH, and ultrasound-mediated gene-carrying microbubble targeted delivery is a promising development for gene transfer. METHODS: This study successfully established a hyperkinetic PAH rabbit model by a common carotid artery and jugular vein shunt using the cuff style method. Liposome microbubbles carrying the hepatocyte growth factor (HGF) gene were successfully constructed. An in vitro experiment evaluated the appropriate intensity of ultrasonic radiation by Western blots and 3H-TdR incorporation assays. In an in vivo experiment, after transfection of ultrasound-mediated HGF gene microbubbles, catheterisation was applied to collect haemodynamic data. Hypertrophy of the right ventricle was evaluated by measuring the right ventricle hypertrophy index. Western blot and immunohistochemistry analyses were used to detect the expression of human (h)HGF and angiogenic effects, respectively. RESULTS: The most appropriate ultrasonic radiation intensity was 1.0 W/cm2 for 5 minutes. Two weeks after transfection, both systolic pulmonary arterial pressure and mean pulmonary arterial pressure were attenuated. Hypertrophy of the right ventricle was reversed. hHGF was transplanted into the rabbits, resulting in a high expression of hHGF protein and an increase in the number of small pulmonary arteries. Ultrasound-mediated HGF gene microbubble therapy was more effective at attenuating PAH and increasing the density of small pulmonary arteries than single HGF plasmid transfection. CONCLUSIONS: Ultrasound-mediated HGF gene microbubbles significantly improved the target of gene therapy in a rabbit PAH model and enhanced the tropism and transfection rates. Thus, the technique can effectively promote small pulmonary angiogenesis and play a role in the treatment of PAH without adverse reactions.

Dietary chamomile flowers extract improved performance and mitigated aflatoxin B1 toxicity in rabbits.

Aflatoxin B1 (AFB1) is among the poisonous mycotoxins that contaminate food and feed. Limited studies are available on the efficacy of chamomile (Cha) against oxidative stress, liver damage and pro-inflammatory response induced by AFB1. The present study aims to evaluate the effects of Cha on the performance and protective effects against AFB1 in growing rabbits. The experimental rabbits were divided into four different groups, including Cha (70 mg kg day-1), AFB1 (AF; 30 µg kg day-1), AFB1+Cha (AFLCha) and control (CON). The results indicated that the AFB1 treatment had lower values of performance, and carcass parameters compared to the Cha and AFLCha treatments. Furthermore, the Cha and AFLCha groups had lower values of liver and kidney function activities compared to the AFB1 treatment. The higher values of antioxidant enzymes were observed in Cha and AFLCha treatments than in the AFB1 treatment. AFB1 treatments had higher levels of malondialdehyde and liver functions with lower levels of antioxidant enzymes (glutathione and superoxide dismutase) compared to Cha and CON groups. In conclusion, dietary Cha could mitigate the oxidative stress of AFB1-induced liver deterioration.

Prevention of aflatoxin B1 toxicity by pomegranate peel extract and its effects on growth, blood biochemical changes, oxidative stress and histopathological alterations.

Contamination of animal feeds with mycotoxins is one of the most serious issues in the world of animal nutrition. The purpose of this study was to assess the efficacy of pomegranate peel extract (PPE) versus oxytetracycline (OXY) in reducing aflatoxin B1 (AFB1) toxicity in rabbits fed contaminated diets. This experiment was done on 48 weaned NZW, four groups (n = 12). The first (AF) served as the control group feed on an infected diet by AFB1 between 0.02 and 0.03 mg/kg BW; second (AF + OXY) received an infected diet by AFB1 and was treated with OXY 200 mg/kg BW/day; third (AF + PPE) received an infected diet by AFB1 and treated with PPE 130 mg/kg BW/day; fourth (AF + OXY + PPE) received an infected diet by AFB1 and treated with a daily oral dose of 100 mg/kg BW/day of OXY + PPE (65 mg/kg BW/day), the experiment lasted for 8 weeks experiment. The treated group with PPE and its combination with OXY concurrent with AF showed amelioration markedly for liver and kidney function. To summarise, adding PPE and combining it with OXY at a half dose to an AFB1-contaminated diet can help minimise the harmful effects of AFB1 on rabbit performance.

Effect of platelet rich plasma injection on bone formation in the expanded mid-palatal suture in rabbits: a randomized controlled animal study.

BACKGROUND: Mid-Palatal suture expansion needs long retention period due to delayed bone formation in the expanded suture. Platelet-rich plasma (PRP) is a concentrated source of growth factors which increase bone formation. The aim of this study was to evaluate the effect of PRP injection on bone formation in expanded mid palatal suture in rabbits. METHODS: In this prospective randomized controlled animal study, Twenty male rabbits (8-weeks-old) were subjected to mid-palatal expansion for 5 days. Animals were afterwards randomly divided into control group A & study group B. PRP was prepared and injected in the mid-palatal suture in animals belonging to group B only. After 6 weeks of retention, all animals were euthanized, and premaxillae were prepared for histological, histomorphometric and immunohistochemical analysis. Student t-test and paired t-test were used to compare the means of the two groups and within the same group respectively. Significance level set at p ≤ 0.05. RESULTS: Histomorphometric analysis revealed a significant increase (p < 0.001) in the mean percentage of new bone in the study group (14.4%) compared to the control (1.4%). Suture width in study group was significantly wider than the control group (278.8 ± 9µms and 120.4 ± 3.4µms, p < 0.001). There was a significant increase in vascular density in study group than control group (309 ± 65.34 and 243.86 ± 48.1, p = 0.021). Osteopontin immuno-expression revealed a significant increase in optical density in study group than control group (0.21 ± 0.02 & 0.12 ± 0.01, p < 0.001). CONCLUSIONS: In rabbit model, PRP injection can accelerate new bone formation in the expanded mid-palatal suture when compared to the control. This could hopefully result in a more stable midpalatal expansion and a reduced retention period.