Rabbit Ear Vein Research Articles

Untethered & Stiffness-Tunable Ferromagnetic Liquid Robots for Cleaning Thrombus in Complex Blood Vessels.

Thrombosis is a significant threat to human health. However, the existing clinical treatment methods have limitations. Magnetic soft matter is used in the biomedical field for years, and ferromagnetic liquids exhibit tunable stiffness and on-demand movement advantages under magnetic fields. In this study, a ferromagnetic liquid robot (FMLR) is developed and applied it to thrombus removal in complex blood vessels. The FMLR consisted of Fe3O4 magnetic nanoparticles and dimethyl silicone oil. The FMLR can pass through a narrow complex maze through shape deformation by tailoring the intensity and direction of the external magnetic field. Finite element simulation analysis is used to validate the mechanism of controllable FMLR movements. Importantly, the storage modulus of FMLR can be tuned from 0.1 to 2018Pa by varying the external magnetic intensity, ensuring its effectiveness in removing rigid and stubborn thrombi present on the vascular walls. Toward medical robotic applications, FMLR can be used in telerobotic neurointerventional. Experiments demonstrating the capability of FMLR to remove thrombi in the ear veins of rabbits are conducted. This study introduces an efficient approach for thrombus elimination, broadening the utilization of FMLRs within the realm of clinical medicine.

The effectiveness of antimicrobial photodynamic therapy on catheter infection model

Background/AimThis experimental study aimed to examine the effectiveness of transdermal antimicrobial photodynamic therapy (APDT) with and without antimicrobial lock therapy (ALT), on catheter biofilms. MethodsS. epidermidis and C. orthopsilosis biofilms were formed within peripheral venous catheters positioned in the marginal ear veins of New Zealand white rabbits. Biofilm formation was confirmed with scanning electron microscopy in two catheters. 24 catheters with staphylococcal biofilms and 24 with fungal biofilms were treated with APDT, ALT or “APDT plus ALT” for five days. Six catheters were separated as controls. APDT was applied with a red colored LED lamp and methylene blue as the photosensitizer. Vancomycin lock solutions were used as ALT for staphylococcal biofilms and amphotericin B for fungal biofilms. The effect of treatment procedures was evaluated by intraluminal biofilm viability testing based on spectrophotometric evaluation, and a quantitative (OD) value was obtained for each catheter. ResultsThe mean OD values obtained by 600 nm spectrophotometric reading at 24 h (biofilm viability) after “ALT”, “APDT” and “ALT plus APDT” procedures were 0.363, 0.151 and 0.128 for S. epidermidis and 0.092, 0.104 and 0.227 for C. orthopsilosis, respectively. All these OD values obtained after treatment procedures were lower than controls for both S. epidermidis (OD: 0,802) and C. orthopsilosis (OD: 0,315), although there were large fluctuations in our results. ConclusionsOur results suggest that transdermal APDT may be an effective method for treating staphylococcal and candida biofilms formed within intravenous catheters in our rabbit ear model. The combined use of APDT and ALT might be beneficial in these staphylococcal biofilms.

Thermoreversible Gel Formulation for the Intranasal Delivery of Salmon Calcitonin and Comparison Studies of In Vivo Bioavailability.

We developed original thermoreversible (sol-gel) formulations of salmon calcitonin (sCT) for nasal applications. The sol-gel has been compared with commercial intranasal sprays in vitro and in vivo studies. The aim of studying sol-gel form is to arrange the viscosity of formulations for a reversible adequate fluidity at different temperatures. This situation may facilitate the use of drugs as sprays and increase the bioadhesive ability to mucosa. Characterization of optimum formulations was studied. Validated analytical assays determined the number of sCT. An approximately equal number of commercial and sol-gel dosages were sprayed into the nostrils of the rabbits. Blood samples were collected from the ear veins of rabbits and determined by enzyme immunoassay plates. These plates were evaluated by Thermo Labsystem Multiscan Spectrum at 450 nm. Thanks to Winnonlin 5.2, pharmacokinetic data were evaluated by a non-compartmental method. The absolute bioavailability of the formulation at pH 4 and the commercial product (CP) was compared by evaluating the primary pharmacokinetic data area under the curve 0→tlast. The absolute bioavailability of the commercial intranasal spray was measured 1.88 based on maximum concentration (Cmax) assessment. Cmax of the sol-gel formulation pH 4 was calculated as 0.99 and the relative bioavailability was obtained 53.3%. In vivo pharmacokinetic data of sol-gel formulation with pH 3 showed significantly higher volume of distribution parameter than the CP (111167>35408). It is thought that the formulation adhered to the nasal mucosa releases sCT slowly and less.

Potato Alkaloids α-Solanine and α-Chaconine Promote bFGF and VEGF Expression in Vein and Adjacent Tissues in the Rabbit Model of Phlebitis

Objectives: To investigate the therapeutic effect of mashed potato and its alkaloids α-solanine and α-chaconine on basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) expression in ear venous vessels and adjacent tissues in a rabbit model of phlebitis. Materials and Methods: Japanese white rabbits were randomly allocated into control, vaseline cream (model), magnesium sulfate, mashed potato, α-solanine cream 100 mg/kg or 200 mg/kg, and α-chaconine cream 100 mg/kg or 200 mg/kg groups. The phlebitis model was established by intravenous infusion of vincristine in the rabbit ears. Group A received physiological saline. Group B−F was applied treatment 3 times/day, for 2 days along the ears vein. The alkaloid contents in α-solanine and α-chaconine were analyzed with HPLC. The bFGF, protein kinase C alpha (PKC-α), and VEGF expression in the ear vessels and nearby tissues were analyzed using immunohistochemistry, polymerase chain reaction (PCR), and Western blot analysis, respectively. Results: After phlebitis modeling, the vascular endothelium of the rabbit ear vein was damaged or layered, the lumen was swollen and deformed to an oval or round shape, and the proportion of bFGF and VEGF positive areas in the vascular endothelium and adjacent tissues was higher than the control group. The phlebitis score shows that various treatments have certain effects, among which magnesium sulfate wet gauze and mashed potatoes are more effective. The application of α-solanine and α-chaconine cream promotes the expression of bFGF and VEGF, as well as PKC-α in the venous blood vessels and adjacent tissues, but mashed potatoes had little effect. Conclusion: α-solanine and α-chaconine cream can promote the expression of bFGF and VEGF in venous blood vessels and adjacent tissues, which may contribute to the recovery of blood vessels in phlebitis.

Research on Robotic Humanoid Venipuncture Method Based on Biomechanical Model.

Automatic venipuncture robots are expected to replace manual venipuncture methods owing to their high control precision, steady operation, and measurable perception. However, the lack of perception of the venipuncture status in the human body leads to an increased risk and failure rate, which further restricts the development of such robots. To address this, we propose a humanoid venipuncture method guided by a biomechanical model to imitate human sensations and feedback. This method intends to perceive the venipuncture status and improve the performance of the venipuncture robot. First, this study establishes a biomechanical venipuncture model, which thoroughly considers the elastic deformation, cutting, and friction of tissues and can be applied to different venipuncture conditions. Then, venipuncture simulations and in vitro phantom experiments are performed under various settings to analyze and validate the model. Finally, to evaluate the robotic humanoid venipuncture method, we apply the method to a self-developed six-degree-of-freedom venipuncture robot via rabbit ear veins with a success rate of approximately 90%. This work demonstrates that the humanoid venipuncture method based on the biomechanical model is practical and rapid in processing simple information in venipuncture robots.

Hematological and biochemical parameters and resistance of the organism of mother rabbits receiving sulfur compounds

Nanotechnologies are developing continuously, and their use is becoming more diverse and concrete, with high potential to improve the products of animal husbandry and animals in general. Yet, there have been few studies of nanotechnologies in those spheres. However, to confirm the efficiency and, mainly, safety of nanotechnologies, to avoid any harm to the environment or especially humans and animals, substantiated studies are still needed. A promising, but barely studied, direction of research is dosage of nanocompounds of biogenic elements in diets of animals, both modern supplements and alternatives for correcting mineral nutrition. Therefore, the objectives of the study presented here were changes in hematologic, biochemical and immune-biological parameters of the organism of mother rabbits under the influence of sulfur citrate and sodium sulfate for 14 days until insemination and until day 20 of lactation. The research was conducted on mother rabbits of the Hyla breed which were giving birth for the second time in LLC Horlytsia in Dobriany village of Horodok district of Lviv Oblast. Mother rabbits of the control group were fed ad libitum with complete granulated mixed feed with free access to water. Animals of experimental group I were fed feeds of the diet of the control group and during the day were watered sulfate citrate in dosage of 8 µg of S/kg of body weight. Females of experimental group II were fed the diet feeds of the control group and given sodium sulfate (Na2SO4) in the amount of 40 mg of S/kg of body weight. The mother rabbits received the supplements for 14 days both until insemination and for up to the 20th day of lactation. In the preparation period, on day 10 after the beginning of the study and on day 20 of lactation in the experimental period (65th day of watering the supplements), blood samples were taken from the marginal ear vein of the mother rabbits for hematological and biochemical studies. The study revealed that watering sulfate citrate in the dosage of 8 µg of S/kg of the body weight in the diet of mother rabbits for 14 days until insemination and up to day 20 of lactation increased the amount of erythrocytes by 19.5%, leukocytes by 37.5%, granulocytes by 38.3%, concentration of hemoglobin by 21.0%, mean corpuscular hemoglobin by 15.6%, and red cell distribution width by 14.7%, and activated protein metabolism, which manifested in 8.5% higher content of protein and activity of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase respectively by 12.9%, 29.6%, 19.8% and 51.8% lower content of triacylglycerols in the blood on day 20 of lactation compared with the control group. Intake of sulfur citrate heightened the parameters of immunobiological reactivity of the organisms of mother rabbits on day 65 of the experiment with significantly higher level of phagocytic number, phagocytic activity, lysozymic and bactericidal activities of blood serum, protein-associated hexoses, sialic acids and ceruloplasmin and immune globulins, compared with the control. Giving mother rabbits sodium sulfate in the amount of 40 mg/kg of body weight for 65 days led to less notable changes in the blood, expressed in 20.0% increase in mean corpuscular hemoglobin, higher phagocytic value, phagocytic activity, lysozymic and bactericidal activities of blood serum, protein-associated hexoses and ceruloplasmin. The results of the studies indicate possibility of additional use of supplement sulfur citrate in the amount of 8 µg of S/kg in diet of mother rabbits to improve metabolism, reproductive ability and immunological resistance in the period of increased physiological load.

Activated Platelet-Homing Nanoplatform for Targeting Magnetic Resonance Imaging of Aneurysm-Related Thrombus in Rabbits.

Thrombosis is closely related to the instability of intracranial aneurysm (IA), whose rupture is associated with high morbidity and mortality. It is difficult to detect an IA-related thrombus because traditional magnetic resonance imaging (MRI) and even contrast-enhanced MRI cannot clearly distinguish a thrombus from the surrounding tissues. Herein, a nanoplatform [(MFe2O4-ZnDPA nanoparticles (NPs)], consisting of Zn0.4Co0.6Fe2O4@Zn0.4Mn0.6Fe2O4 NPs for imaging and Zn(II)-bis(dipicolylamine) (ZnDPA) for thrombus targeting, is constructed to target an experimental aneurysm-related thrombus in rabbits via MRI. In vitro experiments including platelet safety evaluation primarily prove that MFe2O4-ZnDPA NPs with a high MRI transverse relaxation time (T2) have good biocompatibility. MFe2O4-ZnDPA NPs could target a thrombus via the special interaction between ZnDPA and phosphatidylserine of activated platelets in the thrombus through MRI and Fe quantification assays. Moreover, after MFe2O4-ZnDPA NPs are injected into the ear vein of common carotid artery aneurysm model rabbits, MRI shows that MFe2O4-ZnDPA NPs could accumulate in the aneurysm-related thrombus from 0 to 15 min after injection and decrease in the next 45 min. Meanwhile, MFe2O4-ZnDPA NPs could decrease the MRI T2 signal of the aneurysm-related thrombus to enhance the outline of the aneurysm. This study demonstrates that a nanoplatform can enhance the detection of an aneurysm-related thrombus as well as aneurysm itself to assist further treatment of IA.

Enterococcus faecalis colonizes and forms persistent biofilm microcolonies on undamaged endothelial surfaces in a rabbit endovascular infection model.

ABSTRACTInfectious endocarditis (IE) is an uncommon disease with significant morbidity and mortality. The pathogenesis of IE has historically been described as a cascade of host-specific events beginning with endothelial damage and thrombus formation and followed by bacterial colonization of the nascent thrombus. Enterococcus faecalis is a Gram-positive commensal bacterial member of the gastrointestinal tract microbiota in most terrestrial animals and a leading cause of opportunistic biofilm-associated infections, including endocarditis. Here, we provide evidence that E. faecalis can colonize the endocardial surface without pre-existing damage and in the absence of thrombus formation in a rabbit endovascular infection model. Using previously described light and scanning electron microscopy techniques, we show that inoculation of a well-characterized E. faecalis lab strain in the marginal ear vein of New Zealand White rabbits resulted in rapid colonization of the endocardium throughout the heart within 4 days of administration. Unexpectedly, ultrastructural imaging revealed that the microcolonies were firmly attached directly to the endocardium in areas without morphological evidence of gross tissue damage. Further, the attached bacterial aggregates were not associated with significant cellular components of coagulation or host extracellular matrix damage repair (i.e. platelets). These results suggest that the canonical model of mechanical surface damage as a prerequisite for bacterial attachment to host sub-endothelial components is not required. Furthermore, these findings are consistent with a model of initial establishment of stable, endocarditis-associated E. faecalis biofilm microcolonies that may provide a reservoir for the eventual valvular infection characteristic of clinical endocarditis. The similarities between the E. faecalis colonization and biofilm morphologies seen in this rabbit endovascular infection model and our previously published murine gastrointestinal colonization model indicate that biofilm production and common host cell attachment factors are conserved in disparate mammalian hosts under both commensal and pathogenic contexts.

Effects of Enalapril on TLR2/NF-κB Signaling Pathway and Inflammatory Factors in Rabbits with Chronic Heart Failure.

Chronic heart failure (CHF) refers to the state of persistent heart failure, which is a complex clinical syndrome of various advanced heart diseases. The toll-like receptor 2 (TLR2)/nuclear transcription factor-κB (NF-κB) signal transduction pathway is one of the pathological mechanisms of CHF. Adriamycin can significantly induce the upregulation of TLR2 expression. Angiotensin-converting enzyme inhibitors (ACEI) are commonly used drugs for the treatment of CHF. In our study, the CHF model was established by injection of doxorubicin into the rabbit ear vein. The effect of enalapril on the TLR2/NF-κB signaling pathway in CHF rabbits has been analyzed and determined. Our research results showed that enalapril reduced the inflammatory response by inhibiting the activation of the TLR2/NF-κB signaling pathway, thereby improving cardiac structure, myocardial remodeling, and cardiac function.

Clearance of Carbonyl-Modified Low-Density Lipoproteins in Rabbits

The elimination kinetics of carbonyl-modified low density lipoproteins (LDL) from rabbit bloodstream was studied using isolated LDL of rabbits and humans after preliminary biotinylation or labeling with FITC. Rabbit or human blood plasma LDL were isolated using differential ultracentrifugation in a density gradient; after labeling by biotinylation or by FITC, LDL were modified with various low molecular weight natural dicarbonyls: malondialdehyde (MDA), glyoxal or methylglyoxal. Native (control) and dicarbonyl-modified biotinylated or FITC-labeled LDL were injected into the ear vein of rabbits, and blood samples were taken at certain time intervals. The content of biotinylated LDL in blood plasma was determined by an enzyme immunoassay method; FITC-labeled LDL was determined from the fluorescence spectra. It has been found that glyoxal- and methylglyoxal-modified rabbit and human LDL circulate in the bloodstream of rabbits for almost the same period as native (unmodified) LDL. In contrast to this, MDA-modified rabbit and human LDL were very quickly eliminated from the rabbit bloodstream. Dicarbonyl-modified LDL from human blood plasma is not associated with red blood cells or endothelial cells. We found that using the Oxidized LDL ELISA kits (Mercodia, Sweden) it was possible to identify mainly MDA-modified LDL. The level of MDA-modified LDL in the blood plasma of CHD patients sharply decreased during therapy with evolocumab, the hypocholesterolemic inhibitor of PCSK9 (proprotein convertase of subtilisin/kexin type 9), which activates LDL reutilization in the liver cells. These results explain the extremely rapid clearance of MDA-modified LDL in our experiments by their increased utilization in hepatocytes. The results obtained indicate a high atherogenicity of glyoxal- and methylglyoxal-modified LDL, long-term circulating in the bloodstream.

EFFECT OF SUPPLEMENTATION OF VITAMIN C ON BLOOD GLUCOSE AND GLYCOSYLATED HEMOGLOBIN LEVELS IN EXPERIMENTALLY-INDUCED DIABETIC RABBITS

Objectives: Diabetes mellitus (DM) is a spectrum of common metabolic disorders, arising from a variety of pathogenic mechanisms resulting in hyperglycemia that causes chronic micro- and macro-vascular complications. Vitamin C is structurally similar to glucose and can replace it in many chemical reactions and thus is effective in the prevention of non-enzymatic glycosylation of proteins. Hence, the present study taken up to see the effect of supplementation of Vitamin C on blood glucose and glycosylated hemoglobin (HbA1c) along with metformin in experimentally-induced diabetic rabbits.
 Methods: Twenty-four adult New Zealand white rabbits (1.5–2.5 kg) were divided into four groups, each containing six rabbits. Group 1: Normal control (distilled water); Group 2: Metformin (23.33 mg/kg) is given orally; Group 3: Metformin (23.33 mg/kg) plus Vitamin C 250 mg are given orally; and Group 4: Metformin (23.33 mg/kg) plus Vitamin C 500 mg are given orally. Animals were treated for 30 days. The blood samples were collected on days 0 and 30 from the marginal ear vein of rabbits for the estimation of blood glucose and HbA1c levels.
 Results: Statistically analyzed by ANOVA test followed by post hoc Tukey’s test using GraphPad Prism software. Results shown that Vitamin C 500 mg oral supplementation with metformin had very highly significantly reduced HbA1c levels by 40.12% (p = 0.0001***) and blood glucose levels by 49.12% (p = 0.0003***), whereas Vitamin C 250 mg oral supplementation with metformin also significantly reduced HbA1c levels by 25.49% (p = 0.0001***) and blood glucose levels by 42.95% (p = 0.0026**) when compared to metformin alone, which reduced HbA1c levels by 22% (p = 0.0001***) and blood glucose levels by 39.58% (p = 0.0001***).
 Conclusion: Oral supplementation of Vitamin C 500 mg/250 mg to the metformin was superior in reducing HbA1c levels and blood glucose levels compared to metformin alone in rabbits. Hence, Vitamin C oral supplementation may be helpful in lowering blood glucose levels and HbA1c levels and improving glycemic control in Type 2 DM.

A study on the targeted nanoparticles of isosorbide mononitrate on reducing the levels of inflammatory factors in rabbit models of rhinosinusitis

Objective: To investigate the effect of isosorbide mononitrate (ISMN) targeted nanoparticles on inflammatory factors of sinusitis by establishing a rabbit model of rhinosinusitis. Methods: Thirty healthy rabbits, male and female, weighing 2.5-3.5 kg, were randomly divided into 6 groups with 5 rabbits in each group. Group A was the control group. The model of rabbit sinusitis was established in group B to F, and CT was used to confirm the model was successful. After placing tubes into the maxillary sinus in the group C to F, saline, 45 mg/ml ISMN, 45 mg/ml ISMN nanoparticles and 45 mg/ml ISMN targeted nanoparticles were used to wash the maxillary sinus, respectively. Blood samples were collected from the ear vein of rabbits on day 7, 14, 21, 28, 35 and 42 after modeling respectively. Changes in the expression levels of inflammatory factors in rabbits during the modeling process and after drug washing were detected by ELISA. After the drug intervention, the maxillary sinus mucosa was taken for real-time quantitative PCR to detect the changes in the mRNA level of inflammatory factors. SPSS 22.0 software was used to process the data. Results: Rabbit model of sinusitis was successfully established. ELISA showed that after the action of ISMN targeted nanoparticles of 1 week (42th day after modeling), the levels of (interleukin, IL) 4, IL-8, IL-17A and interferon γ (IFN-γ) in the blood were lower compared with that of 35th day after modeling, the difference was statistically significant (5.57±1.20 vs 19.73±0.68, 66.41±11.87 vs 154.68±13.13, 17.96±1.87 vs 28.23±0.80, 53.56±5.66 vs 111.93±7.29, all P<0.05). Compared with the ISMN nanoparticles and ISMN, the ISMN targeted nanoparticles reduced the levels of IL-4, IL-8, IL-17A and IFN-γ more obviously, the differences were statistically significant (13.26±1.43 vs 8.81±1.33 vs 7.14±2.16, 89.47±17.80 vs 41.07±7.77 vs 15.84±3.72, 10.28±2.07 vs 3.06±1.62 vs 1.82±0.90, 62.16±6.18 vs 35.12±4.62 vs 27.89±10.18, all P<0.05). Real-Time PCR showed that after the flushing of ISMN targeted nanoparticles, the levels of IL-4, IL-8, IL-17A and IFN-γ mRNA were lowest compared with that of the model group, ISMN nanoparticles and ISMN group. Conclusion: ISMN targeted nanoparticles can reduce the level of inflammatory factors in rabbit sinusitis model.

Elimination kinetics of carbonyl-modified low density lipoproteins from bloodstream

The elimination kinetics of carbonyl-modified low density lipoproteins (LDL) from rabbit bloodstream was studied using isolated LDL of rabbits and humans after preliminary biotinylation or labeling with FITZ. LDL from rabbit or human blood plasma were isolated using differential ultracentrifugation in a density gradient, and then LDL were labeled using biotinylation or FITZ, after which they were modified with various low molecular weight natural dicarbonyls: malondialdehyde (MDA), glyoxal or methylglyoxal. Native and dicarbonyl-modified biotinylated or FITZ-labeled LDL were injected into the ear vein of rabbits and blood samples were taken at certain intervals. To determine the content of biotinylated LDL in blood plasma, an enzyme immunoassay was performed; FITZ-labeled LDL were determined by spectra fluorescence. It is shown that glyoxal- and methylglyoxal-modified LDL in rabbits and humans circulated in the bloodstream for almost the same time as native (unmodified) LDL. At the same time, MDA-modified rabbit and human LDL were extremely quickly eliminated from the rabbit bloodstream. Dicarbonyl-modified LDL from the donors blood plasma were not associated with the red blood cells and endothelial cells. It has been shown that using the kits Oxidized LDL ELISA ("Mercodia", Sweden), it is possible to identify mainly MDA-modified LDL. The level of MDA-modified LDL in the blood plasma of CHD patients sharply decreases during therapy with the hypocholesterolemic drug the PCSK9 inhibitor (evulokumab), which activates LDL reutilization in the liver cells. These results explain the extreme drop in the level of MDA-modified LDL by their increased utilization in hepatocytes. The results obtained indicate a high atherogenicity of glyoxal- and methylglyoxal-modified LDL, long-term circulating in the bloodstream.

Preparation and the hemostatic property study of porous gelatin microspheres both in vitro and in vivo

Rapid hemostasis is crucial to saving the lives of traumatic patients in emergency medical treatment. To improve the hemostatic performance of the gelatin microspheres (GMs) in vivo and in vitro, in the study, porous gelatin microspheres (PGMs) were prepared through water-in-oil emulsion method combined with vacuum freeze-drying after cross-linking with glutaraldehyde and prefreeze in liquid nitrogen. Owing to the porous structure and rough surface, the obtained PGMs were effective to induce red blood cells aggregation and promote fibrin generation, which led to improved hemostatic potential than GMs in blood coagulation time, whole blood clotting rate, and the hemostatic efficiency of rabbit liver wound and ear vein cut models tests. The potent hemostatic effect of the PGMs could be attributed to the synergistic effects of the physiological blood coagulation activated by negatively charged surface and physical barriers reinforced by fibrin. Moreover, PGMs with high water absorption rate and porous structure showed better hemostatic performance than commercial hemostatic powder (chitosan hemostasis power and Yunnan Baiyao) in vitro and in vivo. Cytotoxicity tests with bone marrow mesenchymal stem cells of murine showed that PGMs with excellent cytocompatibility were conducive to cell proliferation. Therefore, it could be concluded that PGMs were more suitable for rapid hemostasis than GMs and had a great potential for hemostatic applications.

Assessment of in vivo genotoxicity of citrated-coated silver nanoparticles via transcriptomic analysis of rabbit liver tissue.

BackgroundSilver nanoparticles (AgNPs) are widely used in industrial and household applications, arousing concern regarding their safety in humans. The risks posed by stabilizer-coated AgNPs continue to be unclear, and assessing their toxicity is for an understanding of the safety issues involved in their use in various applications.PurposeWe aimed to investigated the long-term toxicity of citrate-coated silver nanoparticles (cAgNPs) in liver tissue using several toxicity tests and transcriptomic analysis at 7 and 28 days after a single intravenous injection into rabbit ear veins (n=4).Materials and methodsThe cAgNPs used in this study were in the form of a 20% (w/v) aqueous solution, and their size was 7.9±0.95 nm, measured using transmission electron microscopy. The animal experiments were performed based on the principles of good laboratory practice.ResultsOur results showed that the structure and function of liver tissue were disrupted due to a single exposure to cAgNPs. In addition, in vivo comet assay showed unrepaired genotoxicity in liver tissue until 4 weeks after a single injection, suggesting a potential carcinogenic effect of cAgNPs. In our transcriptomic analysis, a total of 244 genes were found to have differential expression at 28 days after a single cAgNP injection. Carefully curated pathway analysis of these genes using Pathway Studio and Ingenuity Pathway Analysis tools revealed major molecular networks responding to cAgNP exposure and indicated a high correlation of the genes with inflammation, hepatotoxicity, and cancer. Molecular validation suggested potential biomarkers for assessing the toxicity of accumulated cAgNPs.ConclusionOur investigation highlights the risk associated with a single cAgNP exposure with unrepaired damage persisting for at least a month.

CLINICOPATHOLOGICAL AND IMMUNOLOGICAL EFFECTS OF USING FORMALIZED KILLED VACCINE ALONE OR IN COMBINATION WITH PROPOLIS AGAINST Pasteurella multocida CHALLENGE IN RABBITS

Pasteurellosis is a common and troublesome issue of rabbits causing serious disorders. The immunization procedures are constantly the greatest preventive measures. In the present study, 40 New Zealand rabbits were used to investigate the protective efficacy of formalized Pasteurella multocida vaccine alone or in combination with propolis. The animals were divided into four equal groups (I-IV); negative control group, challenged non-vaccinated group, vaccinated challenged group and vaccinated propolis administered challenged group respectively. At the end of the 2nd and 6th weeks of the experiment, blood samples were collected from ear vein of rabbits for hematological, plasma, and serum examinations. The rabbits were then anaesthetized and sacrificed to collect tissue specimens from liver, kidneys, spleen and lungs for histopathological study. The results showed that using of propolis in combination with killed vaccine of Pasteurella multocida improved the immune response by increasing the leukocyte phagocytic activity against Pasteurella multocida (from 23.80% to 60.80%). Moreover, the clinicopathological findings including hemogram (RBCs count, Hb content, PCV, RBCs indices, platelets, total and differential leukocytes count), and hepato-renal function tests (ALT, AST, ALP, bilirubin, urea and creatinine), as well as, histopathological findings were better in infected rabbits treated with propolis- killed vaccine than using killed vaccine alone.

Effects of Zhizi Chuanxiong Capsule () on the Abnormal Methylation in Rabbits with Atherosclerosis.

To investigate the effects of Zhizi Chuanxiong Capsule (ZCC, ) on abnormal DNA methylation in a rabbit model of atherosclerosis (AS). After 1 week of adaptive feeding, 48 New Zealand white rabbits were randomly divided into 4 groups: a control group (n=12) fed with normal diet for 22 weeks; a model group (n=12) fed with high fat diet for 14 weeks followed by 8 weeks of normal diet feeding; a low-dose ZCC group (n=12) fed with high fat diet and low-dose ZCC for 14 weeks, followed by 8 weeks of normal diet and low-dose drug; a high-dose ZCC group (n=12) fed with high fat diet and high-dose drug for 14 weeks, followed by 8 weeks of normal diet and high-dose drug. After 22 weeks of feeding, blood samples were taken from the rabbit ear vein, and the genomic DNA was extracted for methylation immunoprecipitation sequencing (Medip-seq). The aorta tissues were collected for hematoxylin-eosin (HE) staining. Eight rabbits died during the feeding process. HE staining showed that the size of the lipid deposition on vessel wall and atherosclerotic plaque formation were reduced in both low- and high-dose group. The Medip-seq results showed that there were 146 abnormally methylated genes (including both hypermethylated gene and hypomethylated genes) in the model group, compared with the control group. Gene Ontology (GO) and Pathway analysis showed that these abnormally methylated genes were found to be involved in multiple AS-related functions and pathways, such as protein kinase C activity, cholesterol transport, mitogen-activated protein kinase (MAPK) signaling pathway, peroxisome proliferater-activated receptor signaling pathway, vascular smooth muscle contraction, inflammation and so on. The abnormal methylated genes in AS model group were altered in both low- and high-dose groups: low-dose ZCC could change 72 of the 146 abnormally methylated genes, high-dose ZCC could change 71. Through GO and Pathway analysis, these altered methylated genes were involved in protein kinase C activity, inflammatory pathway, MAPK signaling pathway, vascular endothelial growth factor signaling pathway, etc. CONCLUSION: ZCC could treat AS through regulating the abnormal hypermethylated and hypomethylated genes in AS rabbit model.

Chitosan-based liposomal thermogels for the controlled delivery of pingyangmycin: design, optimization and in vitro and in vivo studies

Pingyangmycin (PYM) has been applied clinically for many years to treat vascular malformations (VM) in China. The major limitation of PYM injections is quick diffusion from the injection site, which increases side effects, especially the possibility of pulmonary injury. In this paper, chitosan/glycerophosphate disodium (CS/GP) thermogels containing liposomes for sustained and localized PYM delivery were prepared and optimized by a three-level three-factorial Box–Behnken experimental design to evaluate the effects of different variables (the PYM concentration, CS amount and GP content), on the selected responses (cumulative percentage PYM released in 1 day, 9 days and the rate constant k). The results revealed that the optimized PYM liposomal thermogels had a controlled PYM release for 14 days in vitro, which confirmed the validity of optimization. In vitro morphological observation, cell cycle and apoptosis analysis showed an effective anti-proliferation action of PYM liposomal thermogels on human vascular endothelial cells (EA.hy926). In vivo pharmacokinetics research in rabbits displayed that compared with PYM liposomes and PYM thermogels, PYM liposomal thermogels had a better controlled delivery of PYM. Histological examination of rabbit ear veins showed that after local application with PYM lipsomal thermogels for 21 days, obvious vein thrombosis and inflammatory reaction could be observed. The above results indicated that PYM-loaded lipsomal CS/GP thermogels might have a good prospect for the treatment of VM.

Experimental research on preventing mechanical phlebitis arising from indwelling needles in intravenous therapy by external application of mirabilite.

Various types of complications arising from intravenous indwelling needles have become a challenge in clinical care. It is urgent to seek a simple and cost-effective method for prevention and treatment of phlebitis. We investigated the roles of mirabilite in preventing and treating phlebitis caused by intravenous indwelling needles and provide guidance for prevention and treatment of mechanical phlebitis caused by intravenous indwelling needles. A total of 57 healthy congeneric big-eared New Zealand rabbits were randomly divided into 3 groups: blank control, indwelling needle, and group with external application of mirabilite. The ear vein of each rabbit was punctured with an intravenous indwelling needle. The ear vein specimens were taken at 3, 5, and 7 days after indwelling. The hematoxylin and eosin stained pathological tissue sections of the ear veins of the rabbits in each group were observed. The expression levels of IL-1 and IL-6, and tumour necrosis factor-α (TNF-α) in the vascular tissue of the ear veins of the rabbits in each group were detected with the immunofluorescence method. In the blank control group, there was no inflammatory cellular infiltration and no proliferation of fibrous tissue around the vascular wall. With the increase of the indwelling time, proliferation of fibrous tissue in vascular wall, increased inflammatory cellular infiltration and organized thrombus in the vascular tissue occurred in the ear veins of the rabbits in the indwelling needle group and group with external application of mirabilite. Compared with the indwelling needle group, the group with external application of mirabilite had significantly decreased fibrous tissue in the vascular wall and significantly decreased inflammatory cellular infiltration. At the same point in indwelling time, the expression levels of IL-1, IL-6, and TNF-α in the indwelling needle and group with external application of mirabilite were significantly higher than that in the blank control group (P<0.05). The expression levels of IL-1, IL-6, and TNF-α in the group with external application of mirabilite were lower than that in the indwelling needle group (P<0.05). The expression levels of IL-1, IL-6, and TNF-α are positively correlated with the indwelling time within the same group at different points in time. In conclusion, external application of mirabilite can significantly decrease infiltration of venous inflammatory cells of the rabbit ear margin, proliferation of fibrous tissue and thrombosis in the vascular wall, significant decrease the expression levels of IL-1, IL-6, and TNF-α in the mechanical phlebitis caused by intravenous indwelling needles, and decrease the inflammatory responses of the ear veins of rabbits.

Vascular sclerosing effects of bleomycin on cutaneous veins: a pharmacopathologic study on experimental animals.

BackgroundVaricose veins and the complications of venous disease are common disorders in humans.ObjectiveTo study the effects of bleomycin as a potential new sclerosing agent and its adverse events in treating varicose veins.MethodsBleomycin-loaded liposomes 0.1ml was injected in the dorsal ear veins of white New Zealand rabbits. Sodium tetradecyl sulfate was used as a positive control. Normal saline was used as negative control. The blood vessels of the treated ears were photographed before and at one hour and two, eight and 45 days after treatment. Biopsies from the treated areas were obtained for histological examination. Blood samples were collected to determine any possible toxicity.ResultsBleomycin by itself was ineffective; therefore, liposomes were used as a vector to deliver bleomycin to the vein lumen. Subsequently, bleomycin started showing its sclerosing effects. Toxicity monitoring showed no apparent hematologic, pulmonary, hepatic or renal toxicities. This study revealed that bleomycin induced vasculitis, which led to vascular occlusion, which was observed on day 1 and day 8. No bleomycin-related injury was noted by histopathological examination of lung sections. The calculation of the lung/body weight coefficient indicated that edema was present in the experimental groups compared with the negative and positive controls.Study limitationsRelatively small number of experimental animals used.ConclusionsThis study showed that bleomycin-loaded liposomes were able to induce vasculitis and vascular occlusion without any toxicity or complications. It might be useful, hence, to treat patients suffering from Varicose veins and other ectatic vascular diseases with this agent.