Effects of a novel recombinant somatostatin DNA vaccination on rat fertility and offspring growth

In this study, we investigated the immune effects of a novel somatostatin (SS) DNA vaccine—pVAX- asd-GS/2SS (pGS/2SS), administrated with intramuscular (IM) and subcutaneous (SC) two delivery routes on female rat fertility and offspring growth. Results show that this pGS/2SS DNA vaccine could induce effective  anti-SS immune response in rats (IM group and SC group). The antibody peak of female rats in IM group  occurred later than that in SC group (12th week vs. 10th week), but higher than that in SC group  (OD=1.122±0.273 vs. OD=0.614±0.183). Immunized groups had higher pregnancy rate, litter size, birth  weight of pup and weight gain of pup than the control group (P<0.05). Compared to SC immunization, IM  immunization had better improvement in the pregnancy rate of dam and the weight gain of pup (P<0.05).  However, in litter sizes and birth weight of pups, SC immunization was better than IM immunization. In  conclusion, pGS/2SS as a powerful DNA vaccine improves the fertility of female rats and the growth of pups.Key words: Somatostatin, DNA vaccine, rat, fertility, pup growth

Generation of Biotechnology-Derived Flavobacterium columnare Ghosts by PhiX174 Gene E-Mediated Inactivation and the Potential as Vaccine Candidates against Infection in Grass Carp

Flavobacterium columnare is a bacterial pathogen causing high mortality rates for many freshwater fish species. Fish vaccination with a safe and effective vaccine is a potential approach for prevention and control of fish disease. Here, in order to produce bacterial ghost vaccine, a specific Flavobacterium lysis plasmid pBV-E-cat was constructed by cloning PhiX174 lysis gene E and the cat gene with the promoter of F. columnare into the prokaryotic expression vector pBV220. The plasmid was successfully electroporated into the strain F. columnare G4cpN22 after curing of its endogenous plasmid. F. columnare G4cpN22 ghosts (FCGs) were generated for the first time by gene E-mediated lysis, and the vaccine potential of FCG was investigated in grass carp (Ctenopharyngodon idellus) by intraperitoneal route. Fish immunized with FCG showed significantly higher serum agglutination titers and bactericidal activity than fish immunized with FKC or PBS. Most importantly, after challenge with the parent strain G4, the relative percent survival (RPS) of fish in FCG group (70.9%) was significantly higher than FKC group (41.9%). These results showed that FCG could confer immune protection against F. columnare infection. As a nonliving whole cell envelope preparation, FCG may provide an ideal alternative to pathogen-based vaccines against columnaris in aquaculture

[1,1′-Bis(diphenyl­phosphan­yl)ferrocene-κ2 P,P′]dichloridocadmium(II) dichloro­methane disolvate

In the title complex, [CdFe(C17H14P)2Cl2]·2CH2Cl2, the CdII atom has a distorted tetra­hedral coordination geometry by two chloride anions and two P atoms of 1,1′-bis­(diphenyl­phosphan­yl)ferrocene. In the crystal, complex mol­ecules are linked into a three-dimensional network by C—H⋯Cl hydrogen bonds involving the dichloro­methane solvent mol­ecules

Mechanistic evaluation of long-term in-stent restenosis based on models of tissue damage and growth

Development and application of advanced mechanical models of soft tissues and their growth represent one of the main directions in modern mechanics of solids. Such models are increasingly used to deal with complex biomedical problems. Prediction of in-stent restenosis for patients treated with coronary stents remains a highly challenging task. Using a finite element method, this paper presents a mechanistic approach to evaluate the development of in-stent restenosis in an artery following stent implantation. Hyperelastic models with damage, verified with experimental results, are used to describe the level of tissue damage in arterial layers and plaque caused by such intervention. A tissue-growth model, associated with vessel damage, is adopted to describe the growth behaviour of a media layer after stent implantation. Narrowing of lumen diameter with time is used to quantify the development of in-stent restenosis in the vessel after stenting. It is demonstrated that stent designs and materials strongly affect the stenting-induced damage in the media layer and the subsequent development of in-stent restenosis. The larger the artery expansion achieved during balloon inflation the higher the damage introduced to the media layer, leading to an increased level of in-stent restenosis. In addition, the development of in-stent restenosis is directly correlated with the artery expansion during the stent deployment. The correlation is further used to predict the effect of a complex clinical procedure, such as stent overlapping, on the level of in-stent restenosis developed after percutaneous coronary intervention.</div

Multidose Streptozotocin Induction of Diabetes in BALB/c Mice Induces a Dominant Oxidative Macrophage and a Conversion of T(H)1 to T(H)2 Phenotypes During Disease Progression

Macrophages (Mp) are implicated in both early and late phases in type 1 diabetes development. Recent study has suggested that a balance between reductive Mp (RMp) and oxidative Mp (OMp) is possible to regulate T(H)1/T(H)2 balance. The aim of this study is to investigate the redox status of peritoneal Mp and its cytokine profile during the development of autoimmune diabetes induced by multiple low-dose streptozotocin in BALB/c mice. Meanwhile, the polarization of T(H)1/T(H)2 of splenocytes or thymocytes was also examined. We found that peritoneal Mp appeared as an “incomplete” OMp phenotype with decreased icGSH along with disease progression. The OMp showed reduced TNF-α, IL-12, and NO production as well as defective phagocytosis activity compared to nondiabetic controls; however, there was no significant difference with IL-6 production. On the other hand, the levels of IFN-γ or IL-4 of splenocytes in diabetic mice were significantly higher compared to the control mice. The ratio of IFN-γ to IL-4 was also higher at the early stage of diabetes and then declined several weeks later after the occurrence of diabetes, suggesting a pathogenetic T(H)1 phenotype from the beginning gradually to a tendency of T(H)2 during the development of diabetes. Our results implied that likely OMp may be relevant in the development of type 1 diabetes; however, it is not likely the only factor regulating the T(H)1(H)/T(H)2 balance in MLD-STZ-induced diabetic mice

Experimental and computational studies of poly-L-lactic acid for cardiovascular applications: recent progress

Stents are commonly used in medical procedures to alleviate the symptoms of coronary heart disease, a prevalent modern society disease. These structures are employed to maintain vessel patency and restore blood flow. Traditionally stents are made of metals such as stainless steel or cobalt chromium; however, these scaffolds have known disadvantages. An emergence of transient scaffolds is gaining popularity, with the structure engaged for a required period whilst healing of the diseased arterial wall occurs. Polymers dominate a medical device sector, with incorporation in sutures, scaffolds and screws. Thanks to their good mechanical and biological properties and their ability to degrade naturally. Polylactic acid is an extremely versatile polymer, with its properties easily tailored to applications. Its dominance in the stenting field increases continually, with the first polymer scaffold gaining FDA approval in 2016. Still some challenges with PLLA bioresorbable materials remain, especially with regard to understanding their mechanical response, assessment of its changes with degradation and comparison of their performance with that of metallic drug-eluting stent. Currently, there is still a lack of works on evaluating both the pre-degradation properties and degradation performance of these scaffolds. Additionally, there are no established material models incorporating non-linear viscoelastic behaviour of PLLA and its evolution with in-service degradation. Assessing these features through experimental analysis accompanied by analytical and numerical studies will provide powerful tools for design and optimisation of these structures endorsing their broader use in stenting. This overview assesses the recent studies investigating mechanical and computational performance of poly(l-lactic) acid and its use in stenting applications

Finite element evaluation of artery damage in deployment of polymeric stent with pre- and post-dilation

Using finite element method, this paper evaluates damage in an arterial wall and plaque caused by percutaneous coronary intervention. Hyperelastic damage models, calibrated with experimental results, are used to describe stress-stretch responses of arterial layers and plaque; these models are capable to simulate softening behaviour of the tissue due to damage. Abaqus CAE is employed to create the finite element models for the artery wall (with media and adventitia layers), a symmetric uniform plaque, a bioresorbable polymeric stent and a tri-folded expansion balloon. The effect of percutaneous coronary intervention on vessel damage is investigated by simulating the processes of vessel pre-dilation, stent deployment and post-stenting dilation. Energy-dissipation density is used to assess the extent of damage in the tissue. Softening of the plaque and the artery, due to the pre-dilation-induced damage, can facilitate the subsequent stent-deployment process. The plaque and the artery experienced heterogeneous damage behaviour after the stent deployment, caused by non-uniform deformation. The post-stenting dilation was effective to achieve a full expansion of the stent but caused additional damage to the artery. The continuous and discontinuous damage models yielded similar results in the percutaneous coronary intervention simulations, while the incorporation of plaque rupture affected the simulated outcomes of stent deployment. The computational evaluation of the artery damage can be potentially used to assess the risk of in-stent restenosis after percutaneous coronary intervention

Computational evaluation of artery damage in stent deployment

This paper aims to evaluate damage in an arterial wall and plaque caused by percutaneous coronary intervention using a finite-element (FE) method. Hyperelastic damage models, verified against experimental results, were used to describe stress-stretch responses of arterial layers and plaque in the lumen; these models are capable to simulate softening behaviour of the tissue due to damage. Abaqus CAE was employed to create the FE models for an artery wall with two constituent layers (media and adventitia), a symmetric uniform plaque, a bioresorbable polymeric stent and a tri-folded expansion balloon. The effect of percutaneous coronary intervention on vessel damage was investigated by simulating the processes of vessel pre-dilation, stent deployment and post-stenting dilation. Energy dissipation density was used to assess the extent of damage in the tissue. Overall, the plaque experienced the most severe damage due to its direct contact with the stent, followed by the media and adventitia layers. Softening of the plaque and the artery due to the pre-dilation-induced damage can facilitate the subsequent stent-deployment process. The plaque and artery experienced heterogeneous damage behaviour after the stent deployment, caused by non-uniform deformation. The post-stenting dilation was effective to achieve a full expansion of the stent but caused additional damage to the artery. The computational evaluation of artery damage can be also potentially used to assess the risk of in-stent restenosis after percutaneous coronary intervention