Cryoprotective effect of an insect antifreeze protein MpAFP 698 and its mutants from the desert beetle Microdera punctipennis

An insect antifreeze protein, MpAFP698, from the desert beetle Microdera punctipennis, shares 77% similarity with TmTHP (YL-3) from Tenebrio molitor. The predicted tertiary structure for MpAFP698 was modeled as a regular A-helix with TCT motifs arrayed to form the putative ice-binding surface. This model was validated via site-directed mutagenesis. The results suggest that the desert beetle in central Asia has evolved antifreeze proteins similar to those from North America continent. In an additional study, the recombinant MpAFP698 and its mutants were expressed in Escherichia coli strain BL21 (DE3). The thermal hysteresis activity of MpAFP698 was 1.73 degree C at 1.0 mg/ml. MpAFP698 was also tested by in vitro antifreeze activity assay to evaluate its cryoprotective effect at -20 degree C. MpAFP698 displays high cryoprotective effect on bacteria cells at freezing temperatures.

Randomised clinical trial: efficacy of peginterferon alfa-2a in HBeAg positive chronic hepatitis B patients with lamivudine resistance

BACKGROUND

Previous studies suggested that a finite course of peginterferon alfa-2a may offer an alternative rescue therapy for patients with lamivudine resistance. However, because of the limitation of study design and small sample size, it is difficult to make definitive conclusion.

AIM

To explore the role of peginterferon alfa-2a, in the rescue treatment of HBeAg-positive chronic hepatitis B patients with lamivudine resistance.

METHODS

In this randomised study, chronic hepatitis B patients with lamivudine resistance were treated with peginterferon alfa-2a for 48 weeks (n=155) or adefovir for 72 weeks (n=80). All enrolled patients were treated with lamivudine for the first 12weeks.

RESULTS

At 6 months posttreatment, 14.6% (18/123) of peginterferon alfa-2a-treated patients achieved HBeAg seroconversion, in contrast to 3.8% (3/80) of adefovir-treated patients after 72 weeks continuous therapy (P=0.01). For peginterferon alfa-2a-treated patients, the rate of HBeAg seroconversion at week 72 was significantly higher in patients who had HBsAg decline >0.5 Log(10) IU/mL from baseline at week 24, compared with patients with HBsAg decline ≤0.5 Log(10) IU/mL from baseline at week 24 (25.5% vs. 7.7%, P=0.01). After 72 weeks continuous adefovir treatment, 22.5% of patients achieved HBV DNA <80 IU/mL, compared with 10.6% in peginterferon alfa-2a-treated patients at 6months off-treatment (P=0.02).

CONCLUSIONS

Overall, the response to peginterferon alfa-2a among patients with lamivudine resistance was suboptimal. HBeAg seroconversion rate at week 72 by 48 weeks peginterferon alfa-2a treatment was higher than continuous adefovir therapy. Monitoring HBsAg levels can help to predict response to peginterferon alfa-2a.

Cyclin-dependent kinase inhibitor 3 (CDKN3) novel cell cycle computational network between human non-malignancy associated hepatitis/cirrhosis and hepatocellular carcinoma (HCC) transformation

The relationship of cyclin-dependent kinase inhibitor 3 (CDKN3) with tumours has previously been presented in a number of publications. However, the molecular network and interpretation of CDKN3 through the cell cycle between non-malignancy associated hepatitis/cirrhosis and hepatocellular carcinoma (HCC) have remained to be elucidated. Here, we have constructed and analysed significant high expression gene CDKN3 activated and inhibited cell cycle networks from 25 HCC versus 25 non-malignancy associated hepatitis/cirrhosis patients (viral infection HCV or HBV) in GEO Dataset GSE10140-10141, by combination of a gene regulatory network inference method based on linear programming, and decomposition procedure using CapitalBio MAS 3.0 software, based on integration of public databases including Gene Ontology, KEGG, BioCarta, GenMapp, Intact, UniGene, OMIM, and others. Comparing the same and differently activated and inhibited CDKN3 networks with GO analysis, between non-malignancy associated hepatitis/cirrhosis and HCC, our results suggest a CDKN3 cell cycle network (i) with stronger DNA replication and with weaker ubiquitin-dependent protein catabolism as common characteristics in both non-malignancy associated hepatitis/cirrhosis and HCC; (ii) with more cell division and weaker mitotic G2 checkpoint in non-malignancy associated hepatitis/cirrhosis; (iii) with stronger cell cycle and weaker cytokinesis, as a result forming multinucleate cells in HCC. Thus, it is useful to identify CDKN3 cell cycle networks for comprehension of molecular mechanism between non-malignancy associated hepatitis/cirrhosis and HCC transformation.

Fast reciprocating probe system on the EAST superconducting tokamak

A new fast reciprocating probe system (FRPS) has been built and installed on the outer midplane of the EAST tokamak to investigate the profiles of the boundary plasma parameters such as electron density and temperature. The system consists of a two-stage motion drive mechanism: slow motion and fast motion. The fast motion is powered by a servo motor, which drives the probe horizontally up to 50 cm to scan the edge region of the EAST tokamak. The maximum velocity achieved is 2 m/s. High velocity and flexible control of the fast motion are the remarkable features of this FRPS. A specially designed connector installed at the front end of the probe shaft makes it easy to install or replace the probe head on FRPS. During the latest experimental campaign in the spring of 2010, a probe head with seven tips, including two tips for a Mach probe, has been used. An example is given for simultaneous profile measurements of the plasma temperature, plasma density, and the plasma flow velocity.

Association of human papillomavirus 7 with warts in toe webs

BACKGROUND

There have been no studies on the prevalence of types of human papillomavirus (HPV) in cutaneous warts that focus on warts in toe webs (WTW). There is no documented association between HPV 7 and WTW.

OBJECTIVES

To explore the clinical and histopathological features of WTW, and the distribution of HPV genotypes in patients with WTW.

METHODS

The study group consisted of 20 patients with WTW; 31 patients with typical verruca vulgaris (VV) were enrolled as the disease control group, and 53 patients with tinea pedis and 48 healthy volunteers were enrolled as the disease-negative control group. Tissue specimens were analysed for clinical and histological features and distribution of HPV genotypes. Polymerase chain reaction (PCR)-based direct sequencing, TA cloning and type-specific PCR (TS-PCR) were performed in the WTW and VV groups. Interdigital scale specimens from patients with tinea pedis and from healthy volunteers were analysed for HPV DNA by nested PCR and TS-PCR (HPV 7).

RESULTS

All the patients with WTW were male and nearly all were immunocompetent; their mean age was 41 +/- 10 years. The lesions presented mainly as soft, friable and vegetating clusters. HPV 7 was the predominant genotype in WTW with a frequency of 80% (16/20). Fourteen specimens were taken for histopathological examination. The most frequent histological results (seven out of 14) revealed characteristics of HPV 7 infections such as heavily stained cells containing medium-sized keratohyaline granules and a pronounced hyperkeratosis with parakeratosis. TA cloning showed that the sequence shared 90% or more homology with the HPV genotype in direct sequencing. No HPV 7 DNA was found in the scales taken from toe webs without warts.

CONCLUSIONS

This is the first study evaluating the prevalence of HPV types in WTW and the first report of the association between HPV 7 and specific subgroups of patients with warts.

Disruption of PPARgamma signaling results in mouse prostatic intraepithelial neoplasia involving active autophagy

Peroxisome proliferator-activated receptor-gamma (PPARgamma) regulates the interface between cellular lipid metabolism, redox status and organelle differentiation. Conditional prostatic epithelial knockout of PPARgamma in mice resulted in focal hyperplasia which developed into mouse prostatic intraepithelial neoplasia (mPIN). The grade of PIN became more severe with time. Electron microscopy (EM) showed accumulated secondary lysosomes containing cellular organelles and debris suggestive of autophagy. Consistent with this analysis the autophagy marker LC-3 was found to be upregulated in areas of PIN in PPARgamma KO tissues. We selectively knocked down PPARgamma2 isoform in wild-type mouse prostatic epithelial cells and examined the consequences of this in a tissue recombination model. Histopathologically grafted tissues resembled the conditional PPARgamma KO mouse prostates. EM studies of PPARgamma- and PPARgamma2-deficient epithelial cells in vitro were suggestive of autophagy, consistent with the prostatic tissue analysis. This was confirmed by examining expression of beclin-1 and LC-3. Gene expression profiling in PPARgamma-/gamma2-deficient cells indicated a major dysregulation of cell cycle control and metabolic signaling networks related to peroxisomal and lysosomal maturation, lipid oxidation and degradation. The putative autophagic phenotypes of PPARgamma-deficient cells could be rescued by re-expression of either gamma1 or gamma2 isoform. We conclude that disruption of PPARgamma signaling results in autophagy and oxidative stress during mPIN pathogenesis.

Immunohistochemical localization of glucagon and pancreatic polypeptide on rat endocrine pancreas: coexistence in rat islet cells

We used immunofluorescence double staining method to investigate the cellular localization of glucagon and pancreatic polypeptide (PP) in rat pancreatic islets. The results showed that both A-cells (glucagon-secreting cells) and PP-cells (PP-secreting cells) were located in the periphery of the islets. However, A-cells and PP-cells had a different regional distribution. Most of A-cells were located in the splenic lobe but a few of them were in the duodenal lobe of the pancreas. In contrast, the majority of PP-cells were found in the duodenal lobe and a few of them were in the splenic lobe of the pancreas. Furthermore, we found that 67.74% A-cells had PP immunoreactivity, 70.92% PP-cells contained glucagon immunoreactivity with immunofluorescence double staining. Our data support the concept of a common precursor stem cell for pancreatic hormone-producing cells.

Immunohistochemical localization of glucagon and pancreatic polypeptide on rat endocrine pancreas: coexistence in rat islet cells

We used immunofluorescence double staining method to investigate the cellular localization of glucagon and pancreatic polypeptide (PP) in rat pancreatic islets. The results showed that both A-cells (glucagon-secreting cells) and PP-cells (PP-secreting cells) were located in the periphery of the islets. However, A-cells and PP-cells had a different regional distribution. Most of A-cells were located in the splenic lobe but a few of them were in the duodenal lobe of the pancreas. In contrast, the majority of PP-cells were found in the duodenal lobe and a few of them were in the splenic lobe of the pancreas. Furthermore, we found that 67.74% A-cells had PP immunoreactivity, 70.92% PP-cells contained glucagon immunoreactivity with immunofluorescence double staining. Our data support the concept of a common precursor stem cell for pancreatic hormone-producing cells.

[Synthesis in Escherichia coli cells and characterization of the active exoribonuclease of severe acute respiratory syndrome coronavirus]

The nsp14 protein, an exoribonuclease of the DEDD superfamily encoded by severe acute respiratory syndrome coronavirus (SARS-CoV), was expressed in fusion with different affinity tags. The recombinant nspl4 proteins with either GST fusion or 6-histidine tag were shown to possess ribonuclease activity but nspl4 with a short MGHHHHHHGS tag sequence at the N-terminus increased the solubility of nspl4 protein and facilitated the protein purification. Mutations of the conserved residues of nspl4 resulted in significant attenuation but not abolishment of the ribonuclease activity. Combination of fluorescence and circular dichroism spectroscopy analyses showed that the conformational stability of nsp14 protein varied with many external factors such as pH, temperature and presence of denaturing chemicals. These results provide new information on the structural features and would be helpful for further characterization of this functionally important protein.

Synthesis in Escherichia coli cells and characterization of the active exoribonuclease of severe acute respiratory syndrome coronavirus

The nsp14 protein, an exoribonuclease of the DEDD superfamily encoded by severe acute respiratory syndrome coronavirus (SARS-CoV), was expressed in fusion with different affinity tags. The recombinant nsp14 proteins with either GST fusion or 6-histidine tag were shown to possess ribonuclease activity but nsp14 with a short MGHHHHHHGS tag sequence at the N-terminus increased the solubility of nsp14 protein and facilitated the protein purification. Mutations of the conserved residues of nsp14 resulted in significant attenuation but not abolishment of the ribonuclease activity. Combination of fluorescence and circular dichroism spectroscopy analyses showed that the conformational stability of nsp14 protein varied with many external factors such as pH, temperature and presence of denaturing chemicals. These results provide new information on the structural features and would be helpful for further characterization of this functionally important protein.

Which is more important in bioimaging SIMS experiments-The sample preparation or the nature of the projectile?

Sample preparation is central to acquiring meaningful molecule-specific images with SIMS, especially when submicron lateral resolution is involved. The issue is to maintain the distribution of target molecules while attempting to introduce biological cells or tissue into the high vacuum environment of the mass spectrometer. Here we compare freeze-drying, freeze-etching, freeze-fracture and trehalose vitrification as possible strategies for these experiments. The results show that the prospects for successful imaging experiments are greatly improved with all of these methods when using cluster ion bombardment, particularly C(60) (+) ions, not only due to increased sensitivity of this projectiles, but also since it removes contamination overlayers without insult to the underlying chemistry. The emergence of 3-dimensional imaging capabilities also suggests that sample preparation should not perturb the 3-dimensional morphology of the cell, a situation not generally possible during freeze-drying. Hence, sample preparation and projectile type are strongly coupled parameters for bioimaging with mass spectrometry.

Role of export credit agencies in PFI/PPP projects

The paper presents the results of an investigation into the role of export credit agencies (ECAs) in international private-finance initiative/public–private partnership (PFI/PPP) projects. The research was based on an assessment of published literature and a study of relevant official reports. The use of PFI/PPP procurement to deliver essential infrastructure continues to grow worldwide. In developing countries, funding raised locally through taxation, the money markets and official development assistance is inadequate to meet the required needs. PFI/PPP projects with foreign private participation provide a vital contribution to the acceleration of economic growth and provision of essential services and infrastructure. It is demonstrated in this paper that ECAs play a number of key multiple roles in international PFI/PPP projects. First, the role of ECAs can be as lenders. ECA loans can be offered to exporters, investors or directly to the special-purpose vehicle. ECAs also play the role of insurers/guarantors. ECAs are diversified in country risks and therefore best placed to cover political and non-commercial risks. They can provide cover for non-commercial risks which include: currency inconvertibility and transfer restrictions, expropriation, war and civil disturbance or breach of contract, etc. The professional advisory role includes arranging project finance and a disputes resolution service. ECAs play key multiple roles in the realisation of international PFI/PPP projects. They are clearly central to efficient risk management in such projects and for attracting foreign direct investment into infrastructure in developing countries.

Matrix metalloproteinase 2 improves the transplanted adipocyte survival in mice

BACKGROUND

Fat tissue is a common material for autologous transplantation in plastic and reconstructive surgery. Basic fibroblast growth factor (bFGF) ameliorates the fat graft survival. A transplantation model has shown the gene expression of matrix metalloproteinases (MMPs) to increase in adipocytes. The aim of this study is to investigate the role of MMPs in the amelioration of survival by bFGF.

MATERIALS AND METHODS

3T3-L1 adipocytes were incubated with or without 10 microg mL(-1) bFGF for 8 h in the presence or absence of the MMP inhibitor GM6001, vascular endothelial growth factor (VEGF), MMP-2 or anti-bFGF antibody to study the effect of bFGF on MMP-2 mRNA expression, MMP-2 activity, fat accumulation or 2-deoxyglucose uptake. Collagen sheets containing l x l0(7) adipocytes with or without bFGF in the presence or absence of GM6001 were subcutaneously transplanted into mice, and the appearance, histology, mRNA expression and fat accumulation of the grafts were analysed 4 weeks after transplantation.

RESULTS

The MMP-2 expression was drastically induced by bFGF among MMPs in 3T3-L1 adipocytes. MMP-2 accelerated fat accumulation, peroxisome proliferator-activated receptor gamma (PPAR gamma) mRNA expression, and glucose uptake to an extent similar to those induced by bFGF, respectively. The bFGF-induced increases were inhibited by the blocking of MMP-2. The transplantation of adipocytes into mice showed that bFGF ameliorates the appearance and fat accumulation, as well as mRNA expression in grafts. These effects were almost or partly inhibited by a MMP blockade.

CONCLUSIONS

MMP-2 may be involved in the mechanism by which bFGF ameliorates the survival of fat grafts.

The correlation between cotransplantation of mesenchymal stem cells and higher recurrence rate in hematologic malignancy patients: outcome of a pilot clinical study

In this open-label randomized clinical trial, HLA-identical sibling-matched hematopoietic stem cells (HSC) were transplanted (non-MSCs group, n=15) or cotransplanted with mesenchymal stem cells (MSCs) (MSCs group, n=10) in hematologic malignancy patients. The median number of MSCs infused was 3.4 x 10(5) kg(-1) (range, 0.3-15.3 x 10(5) kg(-1)). MSCs infusions were well tolerated. The median time to neutrophil engraftment (absolute neutrophil count >0.5 x 10(9) l(-1)) was 16 days for MSCs group and 15 days for non-MSCs group. The median time to platelet engraftment (platelet count >50 x 10(9) l(-1)) was 30 and 27 days, respectively. Grades II-IV acute graft-versus-host disease (GVHD) was observed respectively, in one (11.1%) and eight (53.3%) evaluable patients. Chronic GVHD was found in one (14.3%) and four (28.6%) evaluable patients. The number of patients who relapsed were six (60.0%) and three (20.0%), and the 3-year disease-free survivals were 30.0 and 66.7%, respectively. Thus cotransplantation of MSCs and HSCs may prevent GVHD, but the relapse rate is obviously higher than the control group. We conclude that use of MSCs must be handled with extreme caution before a large-scale clinical trial is performed.