Efficacy of inactivated vaccine against H5N1 influenza virus infection in mice with type 1 diabetes

We sought to determine susceptibility to highly pathogenic avian influenza (HPAI) H5N1 virus and to explore immune protection of inactivated H5N1 vaccine in streptozotocin-induced type 1 diabetic mice. Susceptibility of diabetic mice to an H5N1 virus was evaluated by comparing the median lethal dose (LD(50)) and the lung virus titers with those of the healthy after the viral infection. To evaluate the influence of diabetes on vaccination, diabetic and healthy mice were immunized once with an inactivated H5N1 vaccine and then challenged with a lethal dose of H5N1 virus. The antibody responses, survival rates, lung virus titers and body weight changes were tested. Mice with type 1 diabetes had higher lung virus titers and lower survival rates than healthy mice after H5N1 virus infection. Inactivated H5N1 vaccine induced protective antibody in diabetic mice, but the antibody responses were postponed and weakened. In spite of this, diabetic mice could be protected against the lethal virus challenge by a single dose of immunization when the amount of the antigen increased. These results indicated that type 1 diabetic mice were more susceptible to H5N1 influenza virus infection than healthy mice, and can be effectively protected by inactivated H5N1 vaccine with increased antigen.

Reciprocal effect of mesenchymal stem cell on experimental autoimmune encephalomyelitis is mediated by transforming growth factor-beta and interleukin-6

Mesenchymal stem cells (MSCs) have the ability to suppress T cell proliferation and modulate cytokine production. Recently, MSCs have been shown to ameliorate autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), but in some cases shown to stimulate lymphocyte proliferation. So far, mechanisms through which MSCs modulate immune reactions are still undefined. In this report we demonstrate that MSCs have the capacity for either stimulating or inhibiting myelin basic protein-specific T lymphocytes in a dose-dependent manner and modulate antigen-stimulated T cells to differentiate into either T helper type 17 or regulatory T cells, respectively, via pathways involving transforming growth factor-beta and interleukin-6. These results may lead better utility of MSCs as a treatment for autoimmune disease.

Histone deacetylase inhibitors decrease proliferation potential and multilineage differentiation capability of human mesenchymal stem cells

OBJECTIVES

Histone deacetylase (HDAC) is an important therapeutic target in cancer. Two of the main anticancer mechanisms of HDAC inhibitors are induction of terminal differentiation and inhibition of cell proliferation. To investigate the role of HDAC in maintenance of self-renewal and cell proliferation, we treated mesenchymal stem cells (MSCs) that originated from adipose tissue or umbilical cord blood with valproic acid (VPA) and sodium butyrate (NaBu).

MATERIALS AND METHODS

Human MSCs were isolated from mammary fat tissue and cord blood. We performed MTT assay and flow cytometry-based cell cycle analysis to assess self-renewal of MSCs. In vitro differentiation assays into osteogenic, adipogenic, neurogenic and chondrogenic lineages were conducted to investigate MSC multipotency. Immunocytochemistry, Western blot and reverse transcription-polymerase chain reaction were used to interrogate molecular pathways.

RESULTS

VPA and NaBu flattened the morphology of MSCs and inhibited their growth. VPA and NaBu activated the transcription of p21(CIP1/WAF1) by increasing the acetylation of histone H3 and H4 and eventually blocked the cell cycle at G2/M phase. The expression level of p16(INK4A), a cdk inhibitor that is closely related to cellular senescence, was not changed by HDAC inhibitor treatment. We performed controlled differentiation into bone, fat, cartilage and nervous tissue to elucidate the role of HDAC in the pluripotency of MSC to differentiate into functional tissues. VPA and NaBu decreased the efficiency of adipogenic, chondrogenic, and neurogenic differentiation as visualized by specific staining and reverse transcription-polymerase chain reaction. In contrast, osteogenic differentiation was elevated by HDAC inhibitor treatment.

CONCLUSION

HDAC activity is essential for maintaining the self-renewal and pluripotency of MSCs.

A multicentre study assessing the prevalence of sensitizations in patients with asthma and/or rhinitis in China

BACKGROUND

The prevalence of sensitization in patients with asthma and rhinitis in mainland China remains unclear.

OBJECTIVE

Our aim was to estimate the prevalence of allergy in patients with respiratory allergic diseases such as asthma and/or rhinitis attending respiratory clinics within mainland China. The study also investigated regional and annual differences in the prevalence and pattern of sensitization among the patients in China.

METHOD

A cross-sectional survey was performed in 6304 patients suffering from asthma and/or rhinitis in 17 cities from 4 regions of China. Patients completed a standardized questionnaire asking for the presence of respiratory and allergic symptoms. They also underwent skin prick tests with 13 common aeroallergens.

RESULTS

Among the 6304 patients, 4545 (72.1%) had at least one positive skin prick reaction. The overall prevalence of positive skin prick responses was 59.0% for Dermatophagoides farinae, 57.6% for Dermatophagoides pteronyssinus, 40.7% for Blomia tropicalis, 16.1% for American cockroach, 14.0% for dog, 11.5% for Blatella germanica, 11.3% for Artemisia vulgaris, 10.3% for cat, 6.5% for Ambrosia artemisifolia, 6.3% for mixed mould I, 4.4% for mixed mould IV, 3.5% for mixed grass pollen and 2.2% for mixed tree pollen. Sensitizations to common allergens varied widely between geographical areas and demonstrated unique pattern in patients by stratification with age groups, with asthma and/or rhinitis. Severity of rhinitis and asthma was significantly correlated with skin index of reactivity to Artemisia vulgaris, Ambrosia artemisifolia and to D. pteronyssinus, D. farinae and Blomia tropicalis respectively (P < 0.001). Positive reactivity to the tested allergens and concomitant reactivity to multiple allergens including to house dust mites and Blomia tropicalis was markedly increased in patients with both asthma and rhinitis.

CONCLUSION

House dust mites were the most prevalent allergens in patients with asthma and/or rhinitis in China. There were significant differences in patterns of sensitizations in patients from different geographical areas, age groups as well as asthma and/or rhinitis.

Purinergic contribution to small intestinal afferent hypersensitivity in a murine model of postinfectious bowel disease

Increased sensitivity of the afferent innervation of the gastrointestinal tract reportedly underlies symptoms of discomfort and pain in functional bowel disorders. The present investigation aimed to examine whether the purinergic P2X(2) and P2X(3) receptor subunits contribute to the mechanosensitivity of small intestinal afferents in normal mice and in a murine model of postinfectious gut dysfunction. Mesenteric afferent nerve activity was recorded in a mouse jejunum preparation maintained in vitro. As has been shown previously, ramp distension of the jejunal segment evoked biphasic afferent discharge, reflecting activation of low and high threshold fibres. The average pressure-afferent response curve in mice deficient in both P2X(2) and P2X(3) subunits (n = 14) was not significantly different from that of the wild-type control preparations (n = 13). Application of pyridoxal 5-phosphate 6-azophenyl-2 ,4-disulphonic acid (PPADS) (30 micromol L(-1)), a P2X and P2Y antagonist, or 2,4,6-trinitrophenol-adenosine 5'-triphosphate (10 micromol L(-1)), an antagonist selective for homomeric P2X(3) and heteromeric P2X(2/3) receptors, had no effect on the averaged pressure-afferent response curve in wild-type animals. In Trichinella spiralis-infected mice, the magnitude of mesenteric afferent responses to jejunal distension was greater at day 21 and day 56 postinfection compared with the sham control preparations demonstrating the development of afferent hypersensitivity. PPADS had no significant effect upon mechanically evoked afferent discharge rates in sham treated preparations (n = 5), but significantly inhibited afferent sensitivity to jejunal distension in preparations from mice at day 21 (n = 6) and day 56 (n = 7) postinfection. These results suggest that purinergic mechanisms play no role in mechanosensory transduction in the normal small intestine but contribute significantly to postinfectious mechano-hypersensitivity.

A comparison of potency of and intracellular signaling events provoked by, small molecule and protein-based mpl agonists

e14624

Background: Thrombopoietin (TPO) interacts with its receptor (mpl) to initiate signal transduction and increase platelet production. Other mpl agonists have been developed for clinical use: MDGF (a recombinant protein) and romiplostim (a peptibody) are protein-based mpl agonists; eltrombopag (a small molecule) is a nonpeptide mpl agonist. Methods: Mpl agonists were compared for their ability to induce cellular responses and activate relevant signaling pathways in mpl-expressing cells. Proliferation was assessed by ATP bioluminescence in Baf3/mpl cells treated with mpl agonists for 2 days. Differentiation was assessed by flow cytometric-detection of CD41 and CD61 expression on human CD34+ cells cultured with mpl agonists for 7 days. Activation of signaling pathways was determined by Western blot analysis of proteins from serum-starved Baf3/mpl cells treated with mpl agonists for 20 minutes. Experiments were repeated 3 or more times. Results: The TPO concentration that produced a half-maximal (EC50) proliferative response of Baf3/mpl cells was comparable with that of romiplostim (Table). In contrast, a 30-fold greater concentration of MGDF and a 2,000-fold greater concentration of small molecule were required to produce the same degree of proliferation. In addition, a 1,000,000-fold greater concentration of small molecule compared with romiplostim was required to produce an EC50 for differentiation of CD34+ cells. Mpl agonists activated identical signaling pathways in Baf3/mpl cells: a similar dose-response for phosphorylation of JAK2, Stat3, Stat5, Erk1/2, and AKT was observed at their respective EC10, EC50, and EC100 concentrations. Conclusions: In Baf3/mpl cells, the small molecule was between 1,000- and 1,000,000-fold less potent than protein-based mpl agonists when corrected for molecular mass differences. Small molecule and protein-based mpl agonists were indistinguishable when mpl intracellular signaling was compared at similarly effective concentrations. [Table: see text]

[Table: see text]

Computerized endoscopic balloon manometry to detect esophageal variceal pressure

BACKGROUND AND STUDY AIMS

Measuring the variceal pressure is important in predicting esophageal variceal bleeding. However, current noninvasive methods of measuring variceal pressure have not gained wide popularity. We have developed a computerized endoscopic balloon manometry (CEBM) system to detect variceal pressure. The aims of the study were to test the in-vitro accuracy of CEBM and to evaluate the clinical reliability and feasibility of this method.

PATIENTS AND METHODS

The CEBM system, comprising an esophageal variceal manometer and a computer, records variceal pressure and manometry images simultaneously. In the in-vitro study, variceal models were fixed inside an artificial esophagus, into which an endoscope with transparent balloon was inserted for intraluminal pressure measurement. The artificial varix was filled with water and connected to a water column to modulate the intraluminal pressure. This CEBM system was tested blindly in variceal models with different intraluminal pressures. CEBM was also used to measure variceal pressure in 23 patients with liver cirrhosis and esophageal varices, and the results were compared with the hepatic venous pressure gradient (HVPG).

RESULTS

In the in-vitro study, the measured intraluminal pressure correlated significantly with the actual intraluminal pressure for different diameters (R > or = 0.993, P < 0.001). Variceal pressure measurements with CEBM were technically successful in 23 patients. Regression analysis showed a good correlation between variceal pressure measured with CEBM and the HVPG (R = 0.858, P < 0.001).

CONCLUSIONS

Our preliminary results indicate that CEBM is feasible and accurate. CEBM may become a more reliable method for detecting variceal pressure.

One-neutron removal measurement reveals 24O as a new doubly magic nucleus

The first measurement of the momentum distribution for one-neutron removal from (24)O at 920A MeV performed at GSI, Darmstadt is reported. The observed distribution has a width (FWHM) of 99 +/- 4 MeV/c in the projectile rest frame and a one-neutron removal cross section of 63 +/- 7 mb. The results are well explained with a nearly pure 2s_{1/2} neutron spectroscopic factor of 1.74 +/- 0.19 within the eikonal model. This large s-wave probability shows a spherical shell closure thereby confirming earlier suggestions that (24)O is a new doubly magic nucleus.

IL-17 eliminates the therapeutic effects of myelin basic protein-induced nasal tolerance in experimental autoimmune encephalomyelitis by activating IL-6

Interleukin (IL)-17 is a proinflammatory cytokine primarily secreted by Th17 cells, which are a CD4(+) T-cell subset. Th17 cells and IL-17 are important in the pathogenesis of multiple sclerosis and in its established animal model, experimental autoimmune encephalomyelitis (EAE). However, it is unclear whether IL-17 contributes to EAE immune tolerance. We used the myelin basic protein (MBP) peptide MBP 68-86 to induce nasal tolerance to EAE, and simultaneously interfered with the tolerance by treatment with different doses of IL-17. We found that IL-17 dramatically interfered with MBP 68-86-induced immune tolerance. IL-17 administration increased IL-6 release, skewing T cell differentiation towards Th17 cells and decreasing the number of Treg cells. This led to an imbalance between Treg cells and Th17 cells and spurred the development of EAE.

Murine bone marrow mesenchymal stem cells cause mature dendritic cells to promote T-cell tolerance

Bone mesenchymal stem cells (BMSC) are attractive not only in regenerative medicine, but also for the treatment of autoimmune diseases and graft-versus-host disease. BMSC also play a role in enabling alloantigen tolerance. An in-depth mechanistic understanding of this phenomenon of tolerance could lead to novel cell-based therapies for autoimmune disease. We demonstrate here that co-culture of mature dendritic cells (DC) with BMSC in a transwell system (BMSC-DC) downregulated expression of the maturation marker, CD83 and CD80/86 co-stimulatory molecules on DC, while increasing their endocytic activity. This resulted in defective antigen presentation and co-stimulatory capacity of mature DC. Functionally, BMSC-DC have impaired T-cell stimulatory activity in a mixed lymphocyte reaction and orchestrate a shift from predominantly pro-inflammatory T-helper (Th)-1 to anti-inflammatory Th2 cells. While the expression of MHC II, CD80 and CD86 were upregulated on BMSC co-cultured with DC, these BMSC lacked the ability to stimulate T-cell proliferation. Taken together, these data suggest that the interaction between BMSC and DC modulates the immunoregulatory function of these cells in a coordinated manner, effectively skewing the immune response towards T-cell tolerance.

NF-kappaB signaling, liver disease and hepatoprotective agents

The NF-kappaB signaling pathway has particular relevance to several liver diseases including hepatitis (liver infection by Helicobacter, viral hepatitis induced by HBV and HCV), liver fibrosis and cirrhosis and hepatocellular carcinoma. Furthermore, the NF-kappaB signaling pathway is a potential target for development of hepatoprotective agents. Several types of drugs including: selective estrogen receptor modulators (SERMs), antioxidants, proteasome inhibitors, IKK inhibitors and nucleic acid-based decoys have been shown to interfere with NF-kappaB activity at different levels and may be useful for the treatment of liver diseases. However, NF-kappaB also plays an important hepatoprotective function that needs to be taken into consideration during development of new therapeutic regimens.

Estival distribution of dissolved metal concentrations in Liaodong Bay

The temporal and spatial distributions of Cu, Pb, Zn, and Cd in surface water of the Liaodong Bay were studied based on samples collected at 16 sites in June and August from 2001 to 2005. The temporal distribution showed decreasing trends. The concentrations of dissolved metals in the Liaodong Bay were 4.34, 3.21, 31.54, and 0.995 mug/L for Cu, Pb, Zn, and Cd, respectively. Cu and Pb were scattered near the estuaries, and Zn and Cd were mainly found near the Wuli River. Rivers were the main metals pollution sources in the Bay.