Ultra-high resistive switching current ratio and improved ferroelectricity and dielectric tunability performance in a BaTiO3/La0.7Sr0.3MnO3 heterostructure by inserting a SrCoO2.5 layer

A BaTiO3/SrCoO2.5 (BTO/SCO) bilayer and a BTO single film were prepared by radio frequency magnetron sputtering on La0.7Sr0.3MnO3 (LSMO) buffered SrTiO3 (001) substrates. Interestingly, compared with reported BTO-based films, the BTO/SCO/LSMO heterostructure has a maximum ON/OFF current ratio of ∼945. More interestingly, compared with the BTO single layer, a larger Pr (∼18.4 μC cm-2) and larger dielectric tunability (∼71.9%) were achieved in the BTO/SCO bilayer. The improved performance may be attributed to the large tetragonality and improved oxygen vacancy concentrations in the BTO/SCO/LSMO heterostructure. Furthermore, our BTO/SCO/LSMO stacks exhibit potential for flexible electronic informational devices.

[Progress of researches on the involvement of indoleamine 2, 3-dioxygenase in regulation of parasite-host immune interactions]

Indoleamine 2, 3-dioxygenase (IDO) is an important immunoregulatory enzyme, which mediates immune effects by depleting tryptophan and producing multiple metabolites. Recently, the studies on the immune function of IDO have been mostly restricted in tumors and autoimmune diseases. Nevertheless, there are few studies pertaining to the role of IDO in parasitic diseases, notably in parasite-host immune interactions. This review mainly describes IDO-mediated immunoregulatory effects and its regulation of parasite-host interactions, so as to provide insights into the development of immune intervention schemes against parasitic diseases.

[Progress of researches on traveler's diarrhea caused by parasitic infections]

With the rapid development of global tourism, traveling gradually becomes an important part of daily lives, and travelers'health is paid more and more attention. Traveler's diarrhea (TD) is one of the most common diseases among international or trans-regional travelers, which causes great disease and economic burdens. Currently, there is still a lack of systematic studies on the correlation between parasites and TD. The review mainly summarizes intestinal protozoa and helminth infections among patients with TD, so as to provide insights into the development of the control measures for parasitic diseases associated with TD and the prevention of risk factors before the journey to and during the journey of the areas endemic for parasitic diseases.

Repeated exposure to propofol in the neonatal period impairs hippocampal synaptic plasticity and the recognition function of rats in adulthood

Anesthesia of neonates with propofol induces persistent behavioral abnormalities in adulthood. Although propofol-triggered apoptosis of neurons in the developing brain may contribute to the development of cognitive deficits, the mechanism of neurotoxicity induced by neonatal exposure to propofol remains unclear. In this study, the effects of neonatal propofol anesthesia on synaptic plasticity and neurocognitive function were investigated. Postnatal day 7 (PND-7) Sprague-Dawley rats were intraperitoneally injected with fat emulsion or 20, 40 or 60 mg/kg propofol for three consecutive days. The expression of brain-derived neurotrophic factor (BDNF), tropomyosin-related kinase B (TrkB) and postsynaptic density protein 95 (PSD-95) in the rat hippocampus at PND-10 and PND-12 was measured by Western blotting. The number of dendritic branches, total dendritic length and dendritic spine density were observed by Golgi-Cox staining 24 h and 72 h after the last propofol administration. Long-term potentiation (LTP) was measured electrophysiologically in hippocampus of PND-60 rats to evaluate the synaptic function. The learning and memory abilities of rats were evaluated by Morris water maze (MWM) experiments, Novel object recognition test (NORT) and Object location test (OLT) at PND-60. Our results showed that neonatal exposure to propofol significantly inhibited the expression of BDNF, TrkB and PSD-95 in the rat hippocampus. The number of dendritic branches, total dendritic length and dendritic spine density of neurons in the rat hippocampus were markedly reduced after neonatal propofol anesthesia. LTP was significantly diminished in hippocampus of PND-60 rats after repeated exposure to propofol in the neonatal period. Morris water maze experiments showed that repeated neonatal exposure to propofol significantly prolonged the escape latency and decreased the time spent in the target quadrant and the number of platform crossings. NORT and OLT showed that repeated neonatal exposure to propofol markedly reduced the Investigation Time for novel object or location. All of the results above indicate that repeated exposure to propofol in the neonatal period can impair hippocampal synaptic plasticity and the recognition function of rats in adulthood.

[Dynamic changes of myeloid-derived suppressor cells and regulatory T cells in livers of mice infected with Echinococcus granulosus]

OBJECTIVE

To investigate the dynamics changes of the myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells in mice infected with Echinococcus granulosus and explore the possible biological significance.

METHODS

Thirty female BALB/c mice of 6 weeks old were randomly divided into the infection and control groups, of 15 mice in each group. Mice in the infection group were intraperitoneally injected with 2 000 E. granulosus protoscoleces, while those in the control group were injected with the same volume of physiological saline. Mouse liver white blood cells were harvested 3 (early stage), 6 (medium stage) and 12 months (late stage) post-infection, and the proportions of MDSCs, their subpopulations (M-MDSCs and PMN-MDSCs) and Treg cells were assessed by flow cytometry.

RESULTS

The proportions of MDSCs were (1.61 ± 0.36)%, (5.68 ± 0.69)% and (16.18 ± 0.69)% in mouse liver white blood cells in the infection group 3, 6 and 12 months post-infection with E. granulosus, and (2.19 ± 0.42)%, (0.99 ± 0.07) % and (4.18 ± 0.84)% in the control group, and there were significant differences in the proportion of the MDSCs in mouse liver white blood cells between the infection and control groups 6 and 12 months post-infection (P < 0.01). The proportions of M-MDSCs were (0.69 ± 0.27)%, (5.30 ± 0.72)% and (10.75 ± 0.29)% in mouse liver white blood cells in the infection group 3, 6 and 12 months post-infection, and (0.42 ± 0.24)%, (0.69 ± 0.02)% and (2.12 ± 0.13)% in the control group, and there were significant differences in the proportion of the M-MDSCs in the mouse liver white blood cells between the infection and control groups 6 and 12 months post-infection (P < 0.01). The proportions of PMN-MDSCs were (0.93 ± 0.23)%, (0.32 ± 0.02)% and (5.14 ± 1.03)% in mouse liver white blood cells in the infection group 3, 6 and 12 months post-infection, and (1.77 ± 0.26)%, (0.28 ± 0.05)% and (1.99 ± 0.90)% in the control group, and there were significant differences in the proportion of PMN-MDSCs in mouse liver white blood cells between the infection and control groups 3 and 12 months post-infection (P < 0.05). The proportions of Treg cells were (3.35 ± 0.14)%, (6.24 ± 0.38)% and (3.41 ± 0.07)% in mouse liver white blood cells in the infection group 3, 6 and 12 months post-infection, and (3.48 ± 0.46)%, (3.65 ± 0.45)% and (3.12 ± 0.12)% in the control group, and there were significant differences in the proportion of Treg cells in mouse liver white blood cells between the infection and control groups 6 and 12 months post-infection (P < 0.01).

CONCLUSIONS

The percentages of both MDSCs and Treg cells increase in mouse liver white blood cells 6 and 12 months post-infection with E. granulosus, and a more remarkable increase is seen in the percentage of MDSCs, which is mainly found in M-MDSCs. These findings suggest that M-MDSCs may play a major immunosuppressive role in the medium and late stages of E. granulosus infection in mice.

Necrostatin-1 protection of dopaminergic neurons

Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson's disease. We hypothesized that necrostatin-1 could block necroptosis and give protection to dopaminergic neurons. There is likely to be crosstalk between necroptosis and other cell death pathways, such as apoptosis and autophagy. PC12 cells were pretreated with necroststin-1 1 hour before exposure to 6-hydroxydopamine. We examined cell viability, mitochondrial membrane potential and expression patterns of apoptotic and necroptotic death signaling proteins. The results showed that the autophagy/lysosomal pathway is involved in the 6-hydroxydopamine-induced death process of PC12 cells. Mitochondrial disability induced overactive autophagy, increased cathepsin B expression, and diminished Bcl-2 expression. Necrostatin-1 within a certain concentration range (5–30 μM) elevated the viability of PC12 cells, stabilized mitochondrial membrane potential, inhibited excessive autophagy, reduced the expression of LC3-II and cathepsin B, and increased Bcl-2 expression. These findings suggest that necrostatin-1 exerted a protective effect against injury on dopaminergic neurons. Necrostatin-1 interacts with the apoptosis signaling pathway during this process. This pathway could be a new neuroprotective and therapeutic target in Parkinson's disease.

[Short-term curative efficacy of autologous cytokine induced killer cells combined with low-dose IL-2 regimen containing immune enhancement by thymic peptide in elderly patients with B-cell chronic lymphocytic leukemia]

This study was purposed to evaluate the safety and curative effect of autologous cytokine induced killer cells (CIK) combined with low-dose IL-2 regimen containing immune enhancement of thymic peptide on elderly patients with B-cell chronic lymphocytic leukemia (B-CLL). Thymic peptide α1 was subcutaneously given as the immunoenhancement agent at a dose of 1.6 mg/d, 14 days as one cycle. Peripheral blood mononuclear cells (PBMNC) from 5 patients with B-CLL were isolated once a week to induce ex vivo CIK cells through culture in the context of interferon (IFN)-γ, interleukin (IL)-2 and anti-CD3 monoclonal antibody. The PBMNC were separated from patients before and after 14 days as one cycle of thymic peptide α1 administration. Parameters of amplification ability, effector cells quantity, lymphocyte subgroups percentage and antitumor cytotoxicity were compared before and after thymic peptide administration. The 5 patients were treated with CIK cells combined with low-dose IL-2 regimen immediately after injection of thymic peptide α1. The CIK cells plus low-dose IL-2 regimen containing thymic peptide enhancement was defined as: thymic peptide α1 1.6 mg/d was subcutaneously administered once every other day; (4 - 6) ×10(9) of CIK cells were transfused followed by IL-2 subcutaneous administration of 1 mU/d on days 1-10, 28 days as one cycle. Clinical evaluation parameters including cellular immunity function, CLL related biomarkers, disease state and infectious frequency and degree were investigated before and after CIK cells infusion puls IL-2. The results showed that the amount of amplified CIK cells, the percentage and amplification times of effector cells and antitumor cytotoxicity more significantly increased after thymic peptide α1 treatment than before its use (P < 0.05). The total 46 cycles of CIK cells infusion plus IL-2 were completed in the 5 CLL patients. No adverse reaction was observed. After treatment of CIK cells plus IL-2, the general conditions of 5 CLL patients were to different extent improved. Simultaneously, percentages of CD3(+), CD3(+)CD8(+), and CD3(+)CD56(+) cells in peripheral blood remarked by raised (P < 0.05), the serum level of β2 microglobulin was significantly declined (P < 0.05), and the frequency and degree of infection was also decreased (P < 0.05). Following CIK cells plus IL-2 therapy, the transformation of disease state from partial remission (PR) to complete remission was seen in 3 patients, from stable disease (SD) to PR in 1 patient, and from progress of disease to SD in 1 patient. It is concluded that the regimen of autologous CIK cells combined with low-dose IL-2 containing immune enhancement of thymic peptide is safety and effective for the treatment of elderly patients with B-CLL.

rSj16, a recombinant protein of Schistosoma japonicum-derived molecule, reduces severity of the complete Freund's adjuvant-induced adjuvant arthritis in rats' model

Sj16, a 16-kDa protein produced by Schistosoma japonicum, has been demonstrated to have anti-inflammatory effect. However, the possible mechanism of these phenomena has not been discovered. Here, we tried to touch it with arthritis rats' model induced by injection of complete Freund's adjuvant (CFA). A set of pathogenic characters were observed in CFA-treated rat, including local and systematic read-out, which showed the model successfully set up. After administration of rSj16 (recombinant Sj16) in vivo, paw swelling reduced significantly and in a dose-dependent manner, the level of TNF-α, IL-1β and NO decreased and IL-10 in the serum increased. In vitro, rSj16 reversed the augmented surface expression of CD80, CD86, CD54 and OX6 induced by lipopolysaccharide (LPS) in bone marrow-derived DCs (BMDCs), whereas endocytotic capacity of rSj16-treated dendritic cell (DC) was profoundly increased. IL-12p70 released from rSj16-treated BMDC was decreased but IL-10 increased. Further, following incubation with rSj16 primed BMDCs, the sensitized T cells exhibited increased production of anti-inflammatory IL-10 and IL-4 and decreased production of IL-12p70 and IFN-γ. Collectively, these results implied that rSj16 alleviated CFA-induced arthritis, and the possible mechanisms may be its interruption of maturation and function of DCs. rSj16 could be a potential therapeutic agent against rheumatoid arthritis.

[Genome sequencing and genetic analysis of a natural reassortant H5N1 subtype avian influenza virus possessing H9N2 internal genes]

Abstract:One H5N1 subtype avian influenza virus, A/duck/Shandong/009/2008 (Dk/SD/009/08), was isolated from apparently healthy domestic ducks in some live bird market in East China during our epidemiological surveillance. To investigate the genetic composition, Dk/SD/009/08 was subjected to genome sequencing. The amino acid motif of cleavage site was "PLRERRRK-R/GL", which was consistent with the characterization of the HPAIV. According to the newest unified nomenclature system of H5N1, Dk/SD/ 009/08 was classified into Clade 2.3.4. The BLAST results showed that four gene segments (HA, NA, NP and NS) had the highest nucleotide identities with H5N1 subtype AIVs whereas the remaining four (PB2, PB1, PA and M) displayed the closest relationship with H9N2 subtype. Therefore, Dk/SD/009/08 might be a natural reassortant virus. The phylogenetic analysis further indicated that G1-like H9N2 subtype AIVs which was prevalent mainly in quails of Southern China might provide the internal genes for Dk/ SD/009/08.

Calbindin-D28K expression induced by glial cell line-derived neurotrophic factor in substantia nigra neurons dependent on PI3K/Akt/NF-kappaB signaling pathway

Calbindin-D28K is a calcium-binding protein in neuronal cytoplasm, which has the capability to protect neurons from degeneration. It was reported that glial cell line-derived neurotrophic factor (GDNF) increased calbindin-D28K expression in dopaminergic neurons in vitro. It was observed in our research that GDNF also enhanced the expression of calbindin-D28K in adult rat substantia nigra neurons in vivo. To investigate the intracellular signaling pathways underlying the calbindin-D28K expression induced by GDNF, immunoblot and immunoprecipitation analyses were performed in our present study. Our results showed that injection of GDNF alone into substantia nigra of an adult rat brain increased the calbindin-D28K expression; meanwhile, the phosphorylation level of protein kinase B (Akt) and extracellular signal-regulated kinase 1/2 (ERK1/2) increased. However, the calbindin-D28K expression induced by GDNF was specifically blocked by the inhibitor of phosphatidylinositol 3-kinase (PI3K), but the inhibitor of ERK1/2 did not block the calbindin-D28K expression. Furthermore, GDNF administration also caused the nuclear factor kappaB (NF-kappaB/p65), to translocate from cytoplasm into the nucleus, and the inhibitor of PI3K effectively blocked the translocation. Immunoprecipitation assay results further demonstrated that it was the p65/p52 complex of NF-kappaB, rather than the p65/p50 complex that translocated into the neuronal nucleus. The calbindin-D28K expression induced by GDNF was also inhibited when the NF-kappaB signaling pathway was blocked by Helenalin. These results described a novel mechanism by which the activation of PI3K/Akt-->NF-kappaB (p65/p52) signaling pathway could play a role in the calbindin-D28K expression induced by GDNF.

Involvement of NCAM in the effects of GDNF on the neurite outgrowth in the dopamine neurons

Glial cell line-derived neurotrophic factor (GDNF) exerts its biological effects via a multi-component receptor system including the ligand binding receptor--GDNF family receptor-alpha1 (GFRalpha1) and the signaling receptor--RET tyrosine kinase. Recently, the neural cell adhesion molecule (NCAM) has been identified as an alternative signaling receptor for GDNF. The purpose of this study was to investigate whether NCAM could mediate the protective effect of GDNF on injured dopamine (DA) neurons and to determine which cytoplasmic signal molecule associated with NCAM was activated while GDNF performing this effect. The results showed that the phosphorylation of NCAM-associated Fyn was upregulated with GDNF treatment, and this upregulation was inhibited by pre-treatment with the NCAM function-blocking antibody. Moreover, pre-treatment with the antibody could abolish the effect of GDNF on promoting the neurite outgrowth of these DA neurons, except for the effect of GDNF on promoting the expression of tyrosine hydroxylase (TH) in these DA neurons. These results suggest that NCAM is involved in the promotive effect of GDNF on the neurite outgrowth in lesioned DA neurons, but not involved in the promotive effect of GDNF on TH expression in these neurons.

Visual gene diagnosis of HBV and HCV based on nanoparticle probe amplification and silver staining enhancement

A visual gene-detecting technique using nanoparticle-supported gene probes is described. With the aid of gold nanoparticle-supported 3'-end-mercapto-derivatized oligonucleotide serving as detection probe, and 5'-end -amino-derivatized oligonucleotide immobilized on glass surface acting as capturing probe, target DNA was detected visually by sandwich hybridization based on highly sensitive "nano-amplification" and silver staining. Different genotypes of Hepatitis B and C viruses in the serum samples from infected patients were detected using home-made HBV, HCV, and HBV/HCV gene chips by the gold/silver nanoparticle staining amplification method. The present visual gene-detecting technique may avoid limitations with the reported methods, for its high sensitivity, good specificity, simplicity, speed, and cheapness. This technique has potential applications in many fields, especially in multi-gene detection gene chips coupled with the detection will find applications in clinic. Additionally, resonance Rayleigh light scattering (RLS) spectroscopy is used, for the first time, to judge and monitor the immobilization of gene probes on gold nanoparticle surfaces.

TEL1 from Saccharomyces cerevisiae suppresses chromosome aberrations induced by ionizing radiation in ataxia-telangiectasia cells without affecting cell cycle checkpoints

The TEL1 gene from Saccharomyces cerevisiae has been shown to be the closest sequence homologue to ATM, the gene mutated in ataxia-telangiectasia (A-T) patients. Functional homology shared between the ATM and Tell proteins has recently been demonstrated based on heterologous expression of the TEL1 gene in human cells derived from A-T patients. TEL1 expression complemented specific cellular A-T deficiencies, i.e. increased radiation-induced apoptosis, telomere shortening and spontaneous hyperrecombination. The mechanism of cellular A-T complementation by TEL1 appears to be independent of p53-dependent signaling cascades, since the deficiency of A-T cells to properly induce p53 upon ionizing radiation was not corrected by TEL1. We now find that the basic number of chromosome aberrations is increased and the number of radiation-induced chromosome aberrations is suppressed in A-T cells upon TEL1 expression. In cell cycle analyses, we find no changes in basic cell cycle distribution or in radiation-induced cell cycle checkpoints following TEL1 expression. We conclude that the radioprotective function of the Tel1 protein includes suppression of apoptosis and suppression of chromosome aberrations, and that both cellular end-points can be uncoupled from ionizing radiation-induced cell cycle checkpoints.

[The effect of nociception on expression of NADPH-d and fos protein at supraspinal level]

AIM

To study the distribution of NADPH-diaphorase positive neurons in periaqueductal gray matter(PAG) and dorsal raphe nucleus (DR), and the correlation between nitric oxide and peripheral nociception at supraspinal level.

METHODS

20 Sprague-Dawley rats were randomly divided into two groups. In experimental group (n = 10), formalin (5%, 0.1 ml) was injected subcutaneously into the plantar surface of the unilateral hindpaw, and in control group (n = 10), normal saline solution was used alike. The rats were perfused after 2 hours, and the midbrain were removed. Frozen seriate transverse sections were divided into three sets, all of which were processed for NADPH-d histochemistry. Subsequently, the first set that contained NADPH-diaphorase positive neurons were stained with neutral red, and the other two sets were processed for c-fos immunohistochemistry.

RESULTS

NADPH-diaphorase positive neurons were densely distributed in CGLD, CGLV and DR. NADPH-d, Fos and NADPH/Fos double-labeled neurons appeared in CGLD, CGLV and DR after injection of formalin in the rat hindpaw.

CONCLUSION

At supraspinal level NO may play an important role in the modulation of nociception in PAG and DR.

[Cloning and expression of the gene encoding Schistosoma japonicum tropomyosin]

OBJECTIVE

To clone and express the cDNA encoding Schistosoma japonicum tropomyosin.

METHODS

The cDNA was amplified by reverse transcription-polymerase chain reaction (RT-PCR). The PCR products were ligated with pGEM-T vectors and then for transformations. After characterization of white clones by agarose gel electrophoresis, endonucleases digestion and PCR, some recombinant plasmids with inserts were used for sequencing. Then the gene was subcloned into prokaryotic expression vector pQE30 and expression was induced by IPTG.

RESULTS

The PCR products was 823 bp judged by agarose gel electrophoresis and sequencing. A cDNA encoding S. japonicum tropomyosin, except for 14 amino acids at the amino terminus and 2 at the carboxyl terminus, has been constructed and cloned successfully. The colony, designated pGSjcTM12, was sequenced and shown to be 91.1% identical at the nuclei acid level and 98.1% identical in deduced amino acid sequence to that of S. mansoni tropomyosin. The gene was subcloned into pQE30 and an expressed protein of about 32 kDa was obtained.

CONCLUSION

The cloning and expression of the gene encoding S. japonicum tropomyosin had been successfully made.

Two-year follow-up of directly-observed intermittent regimens for smear-positive pulmonary tuberculosis in China

SETTING

The tuberculosis component of the Infectious and Endemic Disease Control Project in the People's Republic of China is the largest single tuberculosis control project in the world using directly-observed therapy and standardized intermittent regimens.

OBJECTIVE

To determine the two-year relapse and mortality rates following completion of treatment.

DESIGN

A prospective cohort study of 649 cases cured in this project. The 306 new and 343 retreatment cases were treated under field conditions with 2H3R3Z3S3/4H3R3 and 2H3R3Z3E3S3/6H3R3E3, respectively. Following treatment completion, two sputum samples were collected every six months for two years and examined for acid-fast bacilli. Causes of death were identified.

RESULTS

The two-year relapse rates for new and retreatment cases were 3.3% and 5.6%, respectively. Retreatment cases with delayed sputum conversion had a greater risk for subsequent relapse. The two-year mortality rate for new and retreatment cases was 3.3% and 8.5%, respectively. The higher mortality rate in retreatment cases was not attributable to relapse of disease, but rather to non-infectious sequelae of tuberculosis.

CONCLUSION

The use of directly-observed intermittent regimens is effective in permanently removing infectious tuberculosis cases from the community.

Association between IgE antibody against soluble egg antigen and resistance to reinfection with Schistosoma japonicum

There is evidence that immunoglobulin (Ig) E antibody may be a critical component of protective immunity against Schistosoma mansoni and S. haematobium reinfection. In the present study, 555 individuals aged 3-67 years infected with S.japonicum received praziquantel treatment before the transmission season commenced; 45 d later, blood samples from 265 individuals who had no S. japonicum egg in their stool were examined by enzyme-linked immunosorbent assay for specific isotypic antibodies. Single, non-conditional logistic regression analysis showed that exposure intensity, age, soluble egg antigen (SEA)-IgE, SEA-IgM and soluble adult worm antigen-IgG4 were relevant to reinfection; multiple, non-conditional logistic regression analysis showed that exposure intensity was still a significant factor for reinfection while the SEA-IgE antibody level was associated with resistance to reinfection with S. japonicum, with a protective index of 2.00. It is suggested that this population in an area endemic for schistosomiasis japonica exhibits acquired immunity.