Contribution of hydrophobic/hydrophilic modification on cationic chains of poly(ε-caprolactone)-graft-poly(dimethylamino ethylmethacrylate) amphiphilic co-polymer in gene delivery

Nanoparticles (NPs) assembled from amphiphilic polycations have been certified as potential carriers for gene delivery. Structural modification of polycation moieties may be an efficient route to further enhance gene delivery efficiency. In this study two electroneutral monomers with different hydrophobicities, 2-hydroxyethyl methacrylate (HEMA) and 2-hydroxyethyl acrylate (HEA), were incorporated into the cationic poly(dimethylamino ethyl methacrylate) (PDMAEMA) side-chains of amphiphilic poly(ε-caprolactone)-graft-poly(dimethylamino ethylmethacrylate) (PCD) by random co-polymerization, to obtain poly(ε-caprolactone)-graft-poly(dimethylamino ethyl methacrylate-co-2-hydroxyethyl methacrylate) (PCD-HEMA) and poly(ε-caprolactone)-graft-poly(dimethylamino ethyl methacrylate-co-2-hydroxyethyl acrylate) (PCD-HEA). Minimal HEA or HEMA moieties in PDMAEMA do not lead to statistically significant changes in particle size, zeta potential, DNA condensation properties and buffering capacity of the naked NPs. However, the incorporation of HEMA and HEA lead to reductions and increases, respectively, in the surface hydrophilicity of the naked NPs and NPs/DNA complexes, which was confirmed by water contact angle assay. These simple modifications of PDMAEMA with HEA and HEMA moieties significantly affect the gene transfection efficiency on HeLa cells in vitro: PCD-HEMA NP/DNA complexes show a much higher transfection efficiency than PCD NPs/DNA complexes, while PCD-HEA NPs/DNA complexes show a lower transfection efficiency than PCD NP/DNA complexes. Fluorescence activated cell sorter and confocal laser scanning microscope results indicate that the incorporation of hydrophobic HEMA moieties facilitates an enhancement in both cellular uptake and endosomal/lysosomal escape, leading to a higher transfection efficiency. Moreover, the process of endosomal/lysosomal escape confirmed in our research that PCD and its derivatives do not just rely on the proton sponge mechanism, but also on membrane damage due to the polycation chains, especially hydrophobic modified ones. Hence, it is proved that hydrophobic modification of cationic side-chains is a crucial route to improve gene transfection mediated by polycation NPs.     

Mechanistic study of transfection of chitosan/DNA complexes coated by anionic poly(γ-glutamic acid)

Chitosan (CS) has been investigated as a non-viral carrier for gene delivery, but resulting in a relatively low transfection. To address this concern, we developed a ternary system comprised the core of CS/DNA complex and the outer coating of an anionic polymer, poly(γ-glutamic acid) (γ-PGA). In molecular dynamic (MD) simulations, we found that γ-PGA was entangle tightly with the excess CS emanating from the surface of test complexes, thus making them more compact. With γ-PGA coating, the extent of test complexes internalized and their transfection efficiency were evidently enhanced. Trypsin treatment induced a concentration-dependent decrease in internalization of the γ-PGA-coated complexes, suggesting a specific protein-mediated endocytosis. The endocytosis inhibition study indicates that the γ-glutamyl transpeptidase (GGT) present on cell membranes was responsible for the uptake of test complexes. The amine group in the N-terminal γ-glutamyl unit on γ-PGA played an essential role in the interaction with GGT. When entangled with CS, the free N-terminal γ-glutamyl unit of γ-PGA on test complexes was exposed and might thus be accommodated within the γ-glutamyl binding pocket of the membrane GGT. Above results suggest that the γ-PGA coating on CS/DNA complexes can significantly enhance their cellular uptake via a specific GGT-mediated pathway. Knowledge of the uptake mechanism is crucial for the development of an efficient vector for gene transfection.     

The synopsis of electroencephaloquadrantogram(EEQG)

EEQG was invented by professor Dekun Wang of Shanxi research institute of Traditional Chinese Medicine . It was further researched and developed by professor Baoyun Yan etc of vice editor in chief of journal of modern electrophysiology and Tianjin medical university and made by Tianjin Hede EEQG technical research and development Co. Ltd. It was made first in our country and was the one and only at home and abroad. It was brand-new and applied widely for psychiatry, neurology, pediatry and oncology etc. Its presentation will bring new hope of of disease for people of China and introduce some relevant questions on diagnosis world. Now, we EEQG.     

The Theory of Bio-Medical Knowledge Integration(Ⅷ)——The Intrinsic Medical Informatics(IMI) and Meta-dimensions(MDs) of SNOMED

This paper presented the profile of Intrinsic Medical Informatics(IMI), which consists of Medical Cognition Informatics(MCI) and Organism Informatics (OI). MCI and OI are taken as two cornerstones of the Theory of BioMedical Knowledge Integration(BMKI). Additionally, so called Meta-dimension architecture of SNOMED is discussed in order to venture its context computing.     

What is the real importance of evaluating the expression of c-erbB-2 (HER-2/neu) in carcinoma of the breast and prostate? (A short review)

This minireview covers the key data on biology and clinical implications of the c-erbB-2 oncogene in breast and prostate cancer. The aim was to provide basic information to practically oriented pathologists in order to make a reasonable application of methods for c-erbB-2 overexpression or amplification analysis. The clinical interpretation of c-erbB-2 abnormalities should reflect the complexity of c-erbB-2 mediated regulatory pathway and explain why tumours with overexpression/amplification of c-erbB-2 very often do not respond to therapy using Herceptin.     

The influence of upstream IL-2 -330 (T/G) and TNF-α -308 (A/G) polymorphisms on glutamine-supplemented cytokine release

Various studies have shown that dietary glutamine can modify the course of an immune response, through altering the release of cytokines. Nutritional supplementation of glutamine may therefore be of advantage to patients, particularly those with compromised immunity. Given that polymorphisms in cytokine genes can also affect cytokine levels, we have undertaken a study to identify whether there was a differential effect of glutamine supplementation in the context of different IL-2 -330 (T/G) and TNF-α -308 (A/G) genotypes. Overall, there was no significant impact of glutamine supplementation on IL2 release. However, analysing low, medium and high expressors independently, there was an effect of high glutamine levels on cytokine release from the low and medium expressors. Likewise, there was no effect of glutamine supplementation on the TNF-α release, although a tendency to lower cytokine release at high levels of glutamine. Irrespective of the glutamine concentrations, there was no difference in IL2 release between the IL2 -330 genotypes; there was an effect of the TNF-α genotypes, with the AG and GG genotypes showing greater cytokine release than from the AA genotype.     

Approaches of the Expanded Programme of Immunization (EPI) and analysis of its failures in the sanitary district of Bouna (Northeast of Côte d'Ivoire)

The anthropological study of the approach of target diseases in the Expanded Programme of Immunization (EPI) in Bouna, a semi-rural district of Northeast C?te d'Ivoire, shows that the population is well-informed about each disease named in this programme as well as for modern vaccination but its objectives remain completely unknown. Populations' reluctances towards vaccination can be explained by several "organizational" causes: overestimated cost of vaccination records, incoherence in the follow-up of vaccination and disruption in the cold chain. These organizational problems are induced by the programme itself and appear more determining than those corresponding to cultural opposition to explain the poor results of the EPI in Bouna. Therefore improvement of these results is linked to the quality of the health cares which can be provided.     

Elimination of Dirofilaria (syn. Nochtiella) repens microfilariae in dogs with monthly treatments of moxidectin 2.5%/imidacloprid 10% (Advocate®, Bayer) spot-on

Elimination of microfilaria in dogs infected with zoonotic Dirofilaria repens would be desirable to reduce further spread. Moxidectin has demonstrated efficacy against microfilariae and safety in dogs infected with Dirofilaria immitis and could be an option for controlling D. repens microfilariae. A field study with 64 dogs previously confirmed positive for D. repens microfilaria was conducted in Hungary, in which a spot-on product (Advocate®, Bayer) was tested. Treatments were applied to 44 dogs once a month for 3 months (five dogs) or 6 months (22 dogs), alternatively every 2 weeks for 6 months (17 dogs). Twenty dogs remained untreated. Microfilaria counts were performed once a month and for a further 6 months following the last treatment. Two weeks after the first treatment, 38 of 44 dogs were microfilaria negative. Four weeks after the initial treatment, one dog still showed a low microfilaria count. Following the second treatment, all treated dogs were negative. This status was maintained during the 6-month observation period after the last treatment. These data demonstrate the successful long-lasting elimination of microfilariae. Moreover, it may be supposed that adult D. repens were killed based on the observation that no further microfilariae were seen up to 6 months after the end of the treatment period.     

夫妻/家庭治疗的效果(综述)

随着社会-心理-生物医学模式的逐步发展,心理治疗的重要性越来越得到人们的重视,但目前所面临问题是:对于临床上看上去很有用的心理干预模式,能否用严格的科学方法验证其有效?这还