Assessment of cardiac diastolic dysfunction in HIV-infected people without cardiovascular symptoms in China

This study assessed cardiac diastolic dysfunction (DD) in HIV-infected subjects without cardiovascular symptoms in China. Eighty-four HIV-infected patients without cardiovascular symptoms were recruited and compared with 30 HIV-negative control subjects. Cardiac DD was evaluated using echocardiography including tissue Doppler imaging. DD was detected in 47.6% of AIDS patients and 42.8% of HIV-positive patients, which was significantly higher than in HIV-negative controls. After logistic regression analysis, HIV infection was independently correlated with cardiac DD (P < 0.05). Among HIV-positive subjects, logistic regression analysis showed that zidovudine exposure was associated with higher prevalence of DD (P < 0.05). Asymptomatic cardiac DD was observed frequently in HIV-infected subjects. HIV infection itself and zidovudine exposure were correlated with a higher prevalence of cardiac DD.

Multivalent immunity targeting tumor-associated antigens by intra-lymph node DNA-prime, peptide-boost vaccination

Active immunotherapy of cancer has yet to yield effective therapies in the clinic. To evaluate the translatability of DNA-based vaccines we analyzed the profile of T-cell immunity by plasmid vaccination in a murine model, using transcriptome microarray analysis and flow cytometry. DNA vaccination resulted in specific T cells expressing low levels of co-inhibitory molecules (most notably PD-1), strikingly different from the expression profile elicited by peptide immunization. In addition, the T-cell response primed through this dual-antigen-expressing plasmid (MART-1/Melan-A and tyrosinase) translated into a substantial proliferation capacity and functional conversion to antitumor effector cells after tyrosinase and MART-1/Melan-A peptide analog boost. Furthermore, peptide boost rescued the immune response against the subdominant tyrosinase epitope. This immunization approach could be adapted to elicit potent immunity against multiple tumor antigens, resulting in a broader immune response that was more effective in targeting human tumor cells. Finally, this study sheds light on a novel mechanism of immune homeostasis through synchronous regulation of co-inhibitory molecules on T cells, highly relevant to heterologous prime boost approaches involving DNA vaccines as priming agents.

Effect of combined treatment with methylprednisolone and Nogo-A monoclonal antibody after rat spinal cord injury

The purpose of this study was to investigate the effects of combination therapy with methylprednisolone (MP) and Nogo-66 antagonistic peptide (NEP1-40) on morphological and functional recovery in adult rats subjected to thoracic compression spinal cord injury (SCI). Animals were randomized into four groups: a trauma control group, an MP group, an NEP1-40 group, and a combined treatment group. The inflammatory reaction, neuronal and oligodendrocyte survival, and ultrastructure were assessed at the injury site. Functional analysis was also performed using Basso, Beattie and Bresnahan (BBB) scoring. Rat behaviour was evaluated regularly up to week 4. NEP1-40 did not alter the beneficial effect of MP on haematogenous inflammatory cell infiltration, while combined treatment resulted in greater neuronal and oligodendrocyte survival compared with monotherapy or control. Combination therapy resulted in better locomotor scores. These results in a clinically-relevant SCI model showed that significant neuroprotection can be obtained by combining an initial acute IV injection of MP with continuously infused NEP1-40.

Human augmenter of liver regeneration: Molecular cloning, biological activity and roles in liver regeneration

The complete amino acid sequence of human augmenter of liver regeneration (hALR) was reported by deduction from nucleotide sequence of its complementary DNA. The cDNA for hALR was isolated by screening a human fetal liver cDNA library and the sequencing of this insert revealed an open reading frame encoding a protein with 125aa and highly homologous (87%) with rat ALR encoding sequence. The recombinant hALR expressed from its cDNA in transient expression experiments in cos-7 cells could stimulate DNA synthesis of HTC hepatoma cell in the dose-dependent and heat-resistant way. Northern blot analysis with rat ALR cDNA as probe confirmed that ALR mRNA was expressed in the normal rat liver at low level and that dramatically increased in the regenerating liver after partial hepatectomied rat. This size of hALR mRNA is 1.4 kb long and expressed in human fetal liver, kidney and testis. These findings indicated that liver itself may be the resource of ALR and suggested that ALR seems to be an important paracrined regulator of liver regeneration.

Ionic Dissolution Products of NovaBone® Promote Osteoblastic Proliferation via Influences on the Cell Cycle

This study investigated the effects of the ionic dissolution products of NovaBone® on osteoblastic proliferation and cell cycle regulation. MG63 osteoblast-like cells were cultured in NovaBone®-conditioned Dulbecco's Modified Eagle's Medium (DMEM) or control DMEM for 10 days. The concentration of silicon ions was significantly higher in NovaBone®-conditioned DMEM than control DMEM. MG63 cells cultured in NovaBone®-conditioned DMEM exhibited greater proliferation on days 1 and 4 than control cells. There were increased proportions of Novabone®-conditioned DMEM-cultured cells in the S and G2/M phases, and decreased proportions in the G0/G1 phase on days 1 and 4 versus control cells, while no differences were observed on days 7 and 10 between the two groups. Bone morphogenic protein 2 production increased in both groups, but was significantly higher for the NovaBone®-conditioned DMEM-cultured cells on day 10 compared with the controls. In conclusion, the NovaBone® ionic dissolution products, particularly the silicon ions, promoted proliferation of MG63 osteoblast-like cells in vitro via influences on the cell cycle.

Efficient differentiation of insulin-producing cells from skin-derived stem cells

OBJECTIVES

Type 1 diabetes mellitus, characterized by loss of pancreatic beta-cells, can be ameliorated by islet transplantation, but this treatment is restricted by the scarcity of islet tissue and by allograft rejection.

MATERIALS AND METHODS

We isolated and characterized skin-derived precursors (SKPs)--an abundant source of autologous cells--and developed an experimental strategy to convert them into insulin-producing cells (IPCs) in vitro within a short period of time, through extracellular factor modification and analyses of IPCs by reverse transcription-polymerase chain reaction, immunocytochemistry and enzyme-linked immunosorbent assay.

RESULTS

SKPs could self-assemble to form three-dimensional islet cell-like clusters (dithizone-positive) and co-express insulin and C-peptide. In addition, they expressed multiple genes related to pancreatic beta-cell development and function (e.g. insulin 1, insulin 2, islet-1, Pdx-1, NeuroD/beta2, glut-2 and Nkx6.1), but not other pancreas-specific hormones and enzymes (e.g. glucagon, somatostatin and amylase). Moreover, when stimulated with glucose, these cells synthesized and secreted insulin in a glucose-regulated manner.

CONCLUSIONS

The findings of this study indicate that SKPs can differentiate into functional IPCs and can provide an abundant source of autologous cells for transplantation. This study also provides strategies to derive autologous islet-replacement tissues from human skin stem cells.

Neutrophil elastase inhibitor prevents endotoxin-induced liver injury following experimental partial hepatectomy

Background

During endotoxaemia, neutrophils activated by inflammatory cytokines release reactive oxygen species and neutrophil elastase, resulting in hepatic necrosis and dysfunction. This study investigated the possible mechanism underlying the protective effect of sivelestat, a neutrophil elastase inhibitor, on endotoxin-induced liver injury following partial hepatectomy.

Methods

Lipopolysaccharide (LPS) was administered intravenously to male Sprague–Dawley rats 48 h after 70 per cent hepatectomy. Sivelestat or normal saline was given intravenously before LPS administration,

Results

Treatment with sivelestat significantly improved the survival rate. Sivelestat prevented increases in the concentration of serum enzymes and total bilirubin related to liver injury. Levels of inflammatory cytokines in serum and liver tissue were significantly lower in the sivelestat-treated group than in the control group. The degree of neutrophil infiltration, necrosis and apoptosis in the remnant liver was significantly decreased in sivelestat-treated rats. Sivelestat pretreatment inhibited the activation of nuclear factor (NF) κB, caspase 3 and 8 activities, and cytochrome c release.

Conclusion

Sivelestat prevents LPS-induced liver injury by inhibition of NF-κB activation and apoptosis.

Fibronectin protects endotoxin-induced liver injury after partial hepatectomy in rats

Endotoxemia following extended hepatectomy may be a cause of postoperative death. Multiple organ failure related to septemia is a common cause of early mortality after liver transplantation. Fibronectins (Fns) are involved in cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, and ischemic injury. Studies were performed to determine whether Fn influences the survival rate of rats subjected to endotoxin-induced liver injury after partial hepatectomy. Male Sprague-Dawley rats were intravenously administered lipopolysaccharide (LPS) 48 hours after 70% hepatectomy. Prior to LPS administration, plasma Fn or bovine serum albumin was given intravenously. The survival rate of the Fn-treated group was higher than that of the controls. Fn prevented increases in serum enzyme activity and total bilirubin related to liver injury. The levels of inflammatory cytokines including tumor necrosis factor-alpha, interleukin-1beta, and interleukin-6 interferon-gamma were also significantly lower in the Fn-treated than the control group. Furthermore, the number of apoptotic cells and the degree of necrosis in the remnant liver were significantly decreased in the Fn-treated rats compared with controls. These results indicate that Fn prevents endotoxin-induced liver injury after partial hepatectomy, at least in part through inhibiting the production of inflammatory cytokines, and the necrosis apoptosis in the remaining liver.

Isolation and characterization of endophytic Streptomyces strains from surface-sterilized tomato (Lycopersicon esculentum) roots

AIMS

To isolate endophytic Streptomyces strains from tomato and examine their antimicrobial activity.

METHODS

Endophytic Streptomyces strains were isolated using surface-sterilization methods and identified by morphological characteristics. Antimicrobial activities were measured by the agar plate sensitivity method. Antifungal activity in vivo was measured by seedling mortality in infested soils.

RESULTS

Twenty-one per cent of endophytic streptomycete isolates produced antibacterial metabolites and 41% produced antifungal metabolites in S medium. Sixty-five per cent of the most frequently isolated strains inhibited the growth of Rhizoctonia solani by the antibiosis assay but only 32% produced metabolites active against R. solani in S medium. Growth promotion and enhanced disease resistance of seedlings inoculated with Streptomyces sp. strain S30 were observed in tomato but not in cucumber seedlings.

CONCLUSIONS

Endophytic Streptomyces spp. strains were successfully isolated using stringent methods and strain S30 promoted growth and enhanced resistance to R. solani in tomato seedlings.

SIGNIFICANCE AND IMPACT OF THE STUDY

Endophytic streptomycetes showing antifungal activity in vitro and in vivo may indicate the potential for their use as biocontrol agents particularly of R. solani disease of tomato seedlings.

Enhanced airway inflammation and decreased subepithelial fibrosis in interleukin 6-deficient mice following chronic exposure to aerosolized antigen

BACKGROUND

Airway inflammation and remodelling are characteristic features of chronic asthma.

OBJECTIVE

To elucidate the role of interleukin (IL)-6 in airway responses to chronic antigen exposure.

METHODS

We compared airway inflammation, subepithelial collagen deposition, cytokine mRNA expression, and airway responsiveness between IL-6-deficient and wild-type (WT) mice following sensitization and repeated exposure to ovalbumin (OVA) three times a week for 8 weeks.

RESULTS

The repeated exposure to OVA induced infiltration of eosinophils, neutrophils, and lymphocytes into the airway, and caused thickening of the basement membrane and subepithelial fibrosis. IL-6-deficient mice exhibited more pronounced infiltration of these cells, a thinner basement membrane, and decreased subepithelial fibrosis, compared with WT mice. The repeated OVA exposure increased expression of IL-4, IL-13, eotaxin, monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-beta1 mRNA in WT mice. Among these factors, expression of IL-13 and MCP-1 mRNA was further enhanced in IL-6-deficient mice, compared with WT mice. However, both WT and IL-6-deficient mice exhibited similar levels of airway responsiveness to increasing doses of methacholine, even after repeated exposure to OVA.

CONCLUSION

These results suggest that IL-6 has dual roles in the chronic phase of asthma: down-regulation of inflammatory cell infiltration and enhancement of airway remodelling.

Fibronectin suppresses apoptosis and protects mice from endotoxic shock

Multiple-organ failure related to septicemia is a common cause of early mortality after liver transplantation. Endotoxemia following living donor hepatectomy may be a cause of postoperative death. Plasma fibronectin (Fn) exerts a broad range of biological effects on cellular adhesion, motility, differentiation, apoptosis, hemostasis, wound healing, reticuloendothelial system function, and ischemic injury. We studied the therapeutic effect of plasma Fn in mice after an intraperitoneal injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Female Balb/c mice received simultaneous intraperitoneal injection of LPS (50 microg/kg) and GalN (400 mg/kg). Thirty minutes prior to GalN/LPS administration, plasma Fn or bovine serum albumin was given intravenously. A single administration of plasma Fn (500 mg/kg) protected in dose-dependent fashion against lethal shock after GalN/LPS challenge. Plasma Fn significantly reduced the serum tumor necrosis factor-alpha, interferon-gamma, and interleukin-6 levels and significantly increased the serum interleukin-10 levels after GalN/LPS administration. Furthermore, plasma Fn significantly inhibited liver necrosis at 9 hours after GalN/LPS injection. The fraction of apoptotic-positive cells in these plasma Fn-treated mice was significantly lower than in the control group. These results support the protective treatment of endotoxin-induced liver injury by plasma Fn.

Recombinant anti-P protein autoantibodies isolated from a human autoimmune library: reactivity, specificity and epitope recognition

The ribosomal P proteins are specific and important autoantigens in patients affected by systemic lupus erythematosus. In this study, we describe for the first time the selection and characterization of recombinant human monoclonal anti-P protein (auto)-antibody fragments from an autoimmune patient-derived phage display antibody library. The selected recombinant anti-P antibodies specifically recognize the P proteins in immunofluorescence assays on HEp-2 cells and in immunoblotting assays, and they immunoprecipitate the P proteins under native conditions. Using both anti-P-positive patient sera and the selected recombinant anti-P antibodies, the immunodominant epitope was determined and shown to be located at the C-terminal end of the P proteins (amino acids 111-115). Inhibition of in vitro protein translation demonstrated that interaction of the monoclonal patient-derived anti-P antibodies with their native epitope functionally inhibits the activity of the P proteins on the ribosome, confirming the notion that patient autoantibodies are often directed to the functional centre of their autoantigenic target.