Free radical polymerization technique was used to formulate Poloxamer-188 based hydrogels for controlled delivery. A total of seven formulations were formulated with varying concentrations of polymer, monomer ad cross linker. In order to assess the structural properties of the formulated hydrogels, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM), and X-ray diffraction (XRD) were carried out. To assess the effect of pH on the release of the drug from the polymeric system, drug release studies were carried in pH 1.2 and 7.4 and it was found that release of the drug was significant in pH 7.4 as compared to that of pH 1.2 which confirmed the pH responsiveness of the system. Different kinetic models were also applied to the drug release to evaluate the mechanism of the drug release from the system. To determine the safety and biocompatibility of the system, toxicity study was also carried out for which healthy rabbits were selected and formulated hydrogels were orally administered to the rabbits. The results obtained suggested that the formulated poloxamer-188 hydrogels are biocompatible with biological system and have the potential to serve as controlled drug delivery vehicles.
- MeSH
- akrylové pryskyřice * chemie MeSH
- diferenciální skenovací kalorimetrie MeSH
- difrakce rentgenového záření MeSH
- hydrogely * chemie MeSH
- koncentrace vodíkových iontů MeSH
- králíci MeSH
- lékové transportní systémy MeSH
- léky s prodlouženým účinkem chemie farmakokinetika MeSH
- mikroskopie elektronová rastrovací MeSH
- nosiče léků chemie MeSH
- poloxamer * chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- termogravimetrie MeSH
- timolol * aplikace a dávkování farmakokinetika chemie MeSH
- uvolňování léčiv MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
In this study, we investigated the mechanism underlying electrocardiogram (ECG) alterations in a rabbit model of acute pulmonary thromboembolism (PTE). Twelve healthy adult New Zealand white rabbits were used, with eight in the experimental group (PTE group) and four in the control group. After developing the rabbit model of acute PTE, ECG and coronary angiography were performed. HE staining was conducted on the right and left ventricular tissues, and polymerase chain reaction (PCR) was used to determine brain natriuretic peptide (BNP), tumor necrosis factor-alpha (TNF-?), and Troponin I (TNI) mRNA expression in the myocardium. There were considerable changes in the ST segment of the ECG in the PTE group. Coronary angiography revealed the absence of spasm, stenosis, and occlusion. In the plasma of the PTE group, the levels of D-dimer, BNP, TNF-?, and TNI were significantly elevated, and these changes were statistically significant (P<0.05). PCR analysis of ventricular myocardial tissue indicated significantly higher levels of BNP, TNF-?, and TNI mRNA in the PTE group than in the control group. These differences were statistically significant (P<0.05). The ST-T variations on the ECG of rabbits with acute PTE correlate strongly with the temporary changes in right heart volume caused by acute PTE. Keywords: Animal model of pulmonary embolism, B-type natriuretic peptide, Electrocardiogram, Pulmonary thromboembolism, Troponin I, Tumor necrosis factor-alpha.
- MeSH
- akutní nemoc MeSH
- elektrokardiografie * MeSH
- králíci MeSH
- modely nemocí na zvířatech * MeSH
- natriuretický peptid typu B krev MeSH
- plicní embolie * patofyziologie krev MeSH
- TNF-alfa krev metabolismus genetika MeSH
- troponin I krev metabolismus MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The treponemes infecting lagomorphs include Treponema paraluisleporidarum ecovar Cuniculus (TPeC) and ecovar Lepus (TPeL), infecting rabbits and hares, respectively. In this study, we described the first complete genome sequence of TPeL, isolate V3603-13, from an infected mountain hare (Lepus timidus) in Sweden. In addition, we determined 99.0% of the genome sequence of isolate V246-08 (also from an infected mountain hare, Sweden) and 31.7% of the genome sequence of isolate Z27 A77/78 (from a European hare, Lepus europeaus, The Netherlands). The TPeL V3603-13 genome had considerable gene synteny with the TPeC Cuniculi A genome and with the human pathogen T. pallidum, which causes syphilis (ssp. pallidum, TPA), yaws (ssp. pertenue, TPE) and endemic syphilis (ssp. endemicum, TEN). Compared to the TPeC Cuniculi A genome, TPeL V3603-13 contained four insertions and 11 deletions longer than three nucleotides (ranging between 6 and2,932 nts). In addition, there were 25 additional indels, from one to three nucleotides long, altogether spanning 36 nts. The number of single nucleotide variants (SNVs) between TPeC Cuniculi A and TPeL V3603-13 were represented by 309 nucleotide differences. Major proteome coding differences between TPeL and TPeC were found in the tpr gene family, and (predicted) genes coding for outer membrane proteins, suggesting that these components are essential for host adaptation in lagomorph syphilis. The phylogeny revealed that the TPeL sample from the European brown hare was more distantly related to TPeC Cuniculi A than V3603-13 and V246-08.
- MeSH
- fylogeneze * MeSH
- genom bakteriální MeSH
- králíci MeSH
- syfilis * mikrobiologie MeSH
- Treponema * genetika izolace a purifikace MeSH
- zajíci * mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Králík patří mezi malé nepřežvýkavé býložravce. Anatomie a fyziologie trávicího traktu králíka se liší od velkých býložravců i přežvýkavců. Trávicí trakt je uzpůsoben k příjmu rostlinné potravy s vysokým obsahem vlákniny, která pro býložravce představuje hlavní zdroj energie. Na rozdíl od přežvýkavců probíhá trávení vlákniny u králíka především v tlustém střevě a je méně efektivní. V článku jsou shrnuty informace o anatomii a fyziologii trávicího traktu králíka a popsány zvláštnosti procesu trávení. Další specifika trávicího traktu jsou popsána také u králíčat na mléčné výživě.
The rabbit is a small non-chewing herbivore. The anatomy and physiology of the digestive tract of the rabbit differs from that of large herbivores and ruminants. The digestive tract is adapted to the intake of high-fibre plant foods, which are the main source of energy for herbivores. In contrast to ruminants, fibre digestion in the rabbit takes place primarily in the large intestine and is less efficient. This article summarises the anatomy and physiology of the rabbit digestive tract and describes the peculiarities of the digestive process. Further specifics of the digestive tract are also described for rabbits on milk diets.
Tento článek pojednává o chirurgickém řešení hydronefrózy (hydronefros) u zakrslého králíka. Jedná se o polymorbidního pacienta s kon kurentním mediastinálním thymomem a otitis media. Na případu našeho pacienta je popsaný laterální chirurgický přístup k nefrektomii, pooperační péče a následný vývoj zdravotního stavu.
This article describes the case of surgically treatment for hydronephrosis in a pet rabbit. Our rabbit is a polymorbidic patient with con current mediastinal thymoma and otitis media. In the case of our patient, the lateral surgical treatment for nephrectomy, postoperative care and subsequent development of overall status are described.
- MeSH
- hydronefróza * diagnostické zobrazování diagnóza patologie MeSH
- králíci MeSH
- nefrektomie metody MeSH
- radioisotopová renografie MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- kazuistiky MeSH
Liposomes are one of the most important drug delivery vectors, nowadays used in clinics. In general, polyethylene glycol (PEG) is used to ensure the stealth properties of the liposomes. Here, we have employed hydrophilic, biocompatible and highly non-fouling N-(2-hydroxypropyl) methacrylamide (HPMA)-based copolymers containing hydrophobic cholesterol anchors for the surface modification of liposomes, which were prepared by the method of lipid film hydration and extrusion through 100 nm polycarbonate filters. Efficient surface modification of liposomes was confirmed by transmission electron microscopy, atomic force microscopy, and gradient ultracentrifugation. The ability of long-term circulation in the vascular bed was demonstrated in rabbits after i.v. application of fluorescently labelled liposomes. Compared to PEGylated liposomes, HPMA-based copolymer-modified liposomes did not induce specific antibody formation and did not activate murine and human complement. Compared with PEGylated liposomes, HPMA-based copolymer-modified liposomes showed a better long-circulating effect after repeated administration. HPMA-based copolymer-modified liposomes thus represent suitable new candidates for a generation of safer and improved liposomal drug delivery platforms.
- MeSH
- akrylamidy chemie MeSH
- aktivace komplementu účinky léků MeSH
- cholesterol chemie krev MeSH
- hydrofobní a hydrofilní interakce * MeSH
- králíci MeSH
- lékové transportní systémy MeSH
- lidé MeSH
- liposomy * MeSH
- myši MeSH
- polyethylenglykoly * chemie MeSH
- polymery chemie MeSH
- povrchové vlastnosti * MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- antilymfocytární sérum * terapeutické užití MeSH
- aplastická anemie * farmakoterapie MeSH
- cyklosporin * terapeutické užití MeSH
- dítě MeSH
- imunosupresiva * terapeutické užití MeSH
- kojenec MeSH
- koně MeSH
- králíci MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- retrospektivní studie MeSH
- výsledek terapie MeSH
- zvířata MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- králíci MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- dopisy MeSH
- srovnávací studie MeSH
Anthracyclines, such as doxorubicin (adriamycin), daunorubicin, or epirubicin, rank among the most effective agents in classical anticancer chemotherapy. However, cardiotoxicity remains the main limitation of their clinical use. Topoisomerase IIβ has recently been identified as a plausible target of anthracyclines in cardiomyocytes. We examined the putative topoisomerase IIβ selective agent XK469 as a potential cardioprotective and designed several new analogs. In our experiments, XK469 inhibited both topoisomerase isoforms (α and β) and did not induce topoisomerase II covalent complexes in isolated cardiomyocytes and HL-60, but induced proteasomal degradation of topoisomerase II in these cell types. The cardioprotective potential of XK469 was studied on rat neonatal cardiomyocytes, where dexrazoxane (ICRF-187), the only clinically approved cardioprotective, was effective. Initially, XK469 prevented daunorubicin-induced toxicity and p53 phosphorylation in cardiomyocytes. However, it only partially prevented the phosphorylation of H2AX and did not affect DNA damage measured by Comet Assay. It also did not compromise the daunorubicin antiproliferative effect in HL-60 leukemic cells. When administered to rabbits to evaluate its cardioprotective potential in vivo, XK469 failed to prevent the daunorubicin-induced cardiac toxicity in either acute or chronic settings. In the following in vitro analysis, we found that prolonged and continuous exposure of rat neonatal cardiomyocytes to XK469 led to significant toxicity. In conclusion, this study provides important evidence on the effects of XK469 and its combination with daunorubicin in clinically relevant doses in cardiomyocytes. Despite its promising characteristics, long-term treatments and in vivo experiments have not confirmed its cardioprotective potential.
- MeSH
- antracykliny * toxicita terapeutické užití MeSH
- chinoxaliny * MeSH
- daunomycin toxicita terapeutické užití MeSH
- DNA-topoisomerasy typu II metabolismus terapeutické užití MeSH
- doxorubicin toxicita MeSH
- inhibitory topoisomerasy II * toxicita terapeutické užití MeSH
- kardiotoxicita MeSH
- králíci MeSH
- krysa rodu rattus MeSH
- poškození DNA MeSH
- protinádorová antibiotika toxicita MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Throughout human evolutionary history, snakes have been associated with danger and threat. Research has shown that snakes are prioritized by our attentional system, despite many of us rarely encountering them in our daily lives. We conducted two high-powered, pre-registered experiments (total N = 224) manipulating target prevalence to understand this heightened prioritization of threatening targets. Target prevalence refers to the proportion of trials wherein a target is presented; reductions in prevalence consistently reduce the likelihood that targets will be found. We reasoned that snake targets in visual search should experience weaker effects of low target prevalence compared to non-threatening targets (rabbits) because they should be prioritized by searchers despite appearing rarely. In both experiments, we found evidence of classic prevalence effects but (contrasting prior work) we also found that search for threatening targets was slower and less accurate than for nonthreatening targets. This surprising result is possibly due to methodological issues common in prior studies, including comparatively smaller sample sizes, fewer trials, and a tendency to exclusively examine conditions of relatively high prevalence. Our findings call into question accounts of threat prioritization and suggest that prior attention findings may be constrained to a narrow range of circumstances.
Background: After injuries, infections, or tumor removal, endogenous healing depends on bone repair. Disorders of bone healing are difficult to treat in clinical settings. There are numerous induced methods for correcting bone abnormalities, such as the induced membrane technique, allogenic bone grafting, synthetic bone grafting, artificial joint replacement, and autologous bone grafting. However, the delivery of the bone graft and bone filling materials necessitates surgical implantation at the fracture site, which could cause edema, infection, and the development of heterotopic bone locally. Therefore, systemically administered osteogenic drugs will provide an excellent method for bone lesion healing. Aim of the study: to evaluate the systemic effect of metformin on bone healing after surgical induction of bony defect and to determine the amount of newly formed bone using histological, histomorphometric analysis, and the surface area measurement of newly formed bone. Also to study the safety of metformin administration at the administered dose for this purpose. Materials and methods: Twenty mature male New Zealand rabbits were separated into two groups, each including ten rabbits for the study. The same surgical procedure was performed on all rabbits. Two holes were made at the femur (3 mm in diameter and 3 mm in depth) and left empty. Metformin tablets were ground into a fine powder and the resultant powder was dissolved in 10ml of water to prepare a liquid dosage containing 50 mg /1ml of metformin. Metformin is administered orally to the rabbits through a feeding tube at a dose of 50 mg/kg body weight. Animals were euthanized at two-time intervals, 14 and 28 days. The femur was separated, sectioned preserved, and sent for histological analysis and histomor-phometry. Results: The results revealed that there is an increase in new bone formation and bone-forming cells in the metformin-treated group. Conclusion: Metformin increases bone healing by increasing the number of bone-forming cells and the surface area of newly formed bone tissues and causes less inflammatory response at the site of a bone lesion. So it possesses an osteogenic effect.
