Proposed long-range empirical potential to study the metallic glasses in the Ni-Nb-Ta system

An n-body potential is constructed for the Ni-Nb-Ta ternary metal system in the newly proposed form of long-range empirical potential. The constructed Ni-Nb-Ta potential can well reproduce the lattice constants, cohesive energies, and elastic modulus of the metals and some compounds as well as the equations of state of the system. Applying the constructed Ni-Nb-Ta potential, molecular dynamics simulations and Voronoi tessellations are carried out to study the issues related to the Ni-Nb-Ta metallic glasses. It is found that increasing the Ni content can obviously improve the glass-forming ability of the binary Nb-Ta system, which features a isomorphous phase diagram unfavoring for forming glass, indicating that the Ni solute plays a decisive role in forming the Nb-based or Ta-based Ni-Nb-Ta metallic glasses. Concerning the atomic structure, the Voronoi cell volume and coordination number (CN) of Ta are generally larger than those of Ni in the binary Ni-Ta metallic glasses. With increasing the Ni concentration, the fraction of icosidihedron (CN=13) increases, while the fractions of icosihexahedron (CN=15) and icosioctahedron (CN=16) decrease. Meanwhile, with increasing the Ni concentration, the dominating coordination numbers of Ta atoms increase. Interestingly, similar feature in the atomic structure with variation of Ni concentration is also observed in the Ni-Nb metallic glasses. For the ternary Ni-Nb-Ta alloys, it is observed from the CN distributions that the structure of the metallic glasses is mostly affected by the Ni concentration.

Effect of amended soil and hydraulic load on enhanced biological nitrogen removal in lab-scale SWIS

To characterize the effect of amended soil on nitrogen removal in subsurface wastewater infiltration system (SWIS), culture, grass carbon, and zeolite were mixed to produce microbial inoculums, and then the optimal microbial inoculums, nutrient substance, cinder, and original soil were mixed to produce the soils through bioaugmentation. Results indicate that the microbial inoculums (culture+50% grass carbon+50% zeolite) and the amended soil (12.5% microbial inoculums+25% nutrient substrate+12.5% cinder+50% original soil) have the optimal biogenic stimulating properties, and the adsorption capacity of the amended soil are 1.216 mg-Pg(-1) and 0.495 mg-Ng(-1). The laboratory soil column experiment indicates that the efficient mode of nitrogen removal in lab-scale SWIS is adsorption-nitrification-denitrification and the nitrification/denitrification can be enhanced by the application of the amended soil. On average, the SWIS filled with amended soil converts 85% of ammonia nitrogen (NH(4)(+)-N) to NO(x)(-)-N and removes 49.8-60.6% of total nitrogen (TN), while the system filled with original soil removes 80% of NH(4)(+)-N and 31.3-43.2% of TN at 4-8 cm day(-1). Two systems are overloads at 10 cm day(-1). It is concluded that the microbial activities and nitrogen removal efficiencies are improved in SWIS after bioaugmentation.

Regulation of food intake and energy expenditure by hypothalamic malonyl-CoA

Energy balance is monitored by the hypothalamus. Malonyl-CoA, an intermediate in fatty acid synthesis, serves as an indicator of energy status in the hypothalamic neurons. The cellular malonyl-CoA level is determined by its rate of synthesis, catalyzed by acetyl-CoA carboxylase (ACC), and rate of removal, by fatty acid synthase (FAS). Malonyl-CoA functions in the hypothalamic neurons that express orexigenic and anorexigenic neuropeptides. Inhibitors of FAS, administered systemically or intracerebroventricularly to mice, increase hypothalamic malony-CoA and suppress food intake. Recent evidence suggests that the changes of hypothalamic malonyl-CoA during feeding and fasting cycles are caused by changes in the phosphorylation state and activity of ACC mediated via 5'-AMP-activated protein kinase (AMPK). Stereotactic delivery of a viral malonyl-CoA decarboxylase (MCD) vector into the ventral hypothalamus lowers malonyl-CoA and increases food intake. Fasting decreases hypothalamic malonyl-CoA and refeeding increases hypothalamic malonyl-CoA, to alter feeding behavior in the predicted manner. Malonyl-CoA level is under the control of AMP kinase which phosphorylates/inactivates ACC. Malonyl-CoA is an inhibitor of carnitine palmitoyl-CoA transferase-1 (CPT1), an outer mitochondrial membrane enzyme that regulates entry into, and oxidation of fatty acids, by mitochondria. CPT1c, a recently discovered, brain-specific enzyme expressed in the hypothalamus, has high sequence similarity to liver/muscle CPT1a/b and binds malonyl-CoA, but does not catalyze the prototypical reaction. This suggests that CPT1c has a unique function or activation mechanism. CPT1c knockout (KO) mice have lower food intake, weigh less and have less body fat, consistent with the role as an energy-sensing malonyl-CoA target. Paradoxically, CPT1c protects against the effects of a high-fat diet. CPT1cKO mice exhibit decreased rates of fatty acid oxidation, consistent with their increased susceptibility to diet-induced obesity. We suggest that CPT1c may be a downstream target of malonyl-CoA that regulates energy homeostasis.

A proteomic study of peripheral blood mononuclear cells in systemic lupus erythematosus

Our objective was to analyze the changes in the protein expression profiles of peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE). Peripheral blood was obtained from patients with SLE and healthy controls. 2-D gel electrophoresis was performed, and gels were silver-stained. Differentially expressed protein spots were detected, some of which were identified by MALDI-TOF spectrometry. Match rates of 71% +/- 4% and 72% +/- 4% were gotten for control and patient gels, respectively. 791 +/- 17 spots were detected for control gels and 781 +/- 17 for patient gels. Eleven protein spots were up-regulated, and 9 protein spots were down-regulated in patients with SLE. Five differentially expressed proteins were identified as immunoglobulin J chain, apolipoprotein A-IV precursor, calprotectin L1H and zinc finger protein subfamily 1A (all up-regulated) and glutathione S-transferase (down-regulated), some of which had previously been shown to play a potential role in the pathogenesis of SLE. We conclude there are significant changes in the 2-D maps of PBMCs in patients with SLE and applying this proteomic approach may be a useful way to gain novel insights into SLE.

Association between nucleotide excision repair gene polymorphisms and chromosomal damage in coke-oven workers

The associations between several genetic polymorphisms of nucleotide excision repair genes (NER) and chromosome damage level were studied among 140 coke-oven workers exposed to a high level of polyaromatic hydrocarbons (PAHs) and 66 non-exposed workers. Seven polymorphisms with functional potential in five NER genes (ERCC1, ERCC2, ERCC4, ERCC5 and ERCC6) were genotyped in the 206 study subjects. Multivariate analysis of covariance revealed that coke-oven workers with the ERCC1 19007 CC genotype had significantly higher cytokinesis-block micronucleus frequency (CBMN) (10.5 +/- 6.8 per thousand) than those with CT (8.1 +/- 6.6 per thousand, p = 0.01) or TT (6.6 +/- 3.7-/ per thousand p = 0.05) or CT+TT genotypes (7.5 +/- 6.3 per thousand, p = 0.004). The ERCC6 A3368G polymorphism was also associated with CBMN frequency among coke-oven workers. Subjects with the AA genotype have a significantly higher CBMN frequency (10.0 +/- 6.9 per thousand) than those with AG (6.7 +/- 4.2 per thousand, p = 0.05) or AG+GG genotypes (6.6 +/- 4.1 per thousand, p = 0.02). Stratification analysis revealed the significant associations between ERCC1 C19007T and ERCC6 A3368G, and the CBMN frequencies were only found among older workers. In addition, a significant association between ERCC2 G23591A polymorphism and CBMN frequencies was also found among older coke-oven workers. The results suggest that polymorphisms of ERCC1 C19007T, ERCC6 A3368G and ERCC2 G23591A are associated with the CBMN frequencies among coke-oven workers.

Association between magnesium : iron intake ratio and diabetes in Chinese adults in Jiangsu Province

BACKGROUND

The intake of iron is positively related to the risk of diabetes, whilst magnesium intake is inversely related. However, it is unknown whether there is an interaction between dietary magnesium and iron expressed as a ratio and diabetes.

METHODS

This is a cross-sectional household survey carried out in 2002 in Jiangsu Province, China. A total of 2849 men and women aged >or = 20 years participated (participation rate 89.0%). Iron and magnesium intake was assessed by 3-day weighed food records. Fasting plasma glucose, serum ferritin and haemoglobin were measured.

RESULTS

The mean intake of iron and magnesium was 25 mg/day and 332 mg/day, respectively. The prevalence of diabetes was 3.0% in men and 2.6% in women. Magnesium intake was negatively associated with diabetes when adjusted for age and sex, but not in a fully adjusted model. A strong inverse association between magnesium : iron intake ratio and diabetes was observed. In the fully adjusted model, the odds ratios of diabetes across quartiles of magnesium : iron intake ratio were: 1.0, 0.63 [95% confidence interval 0.32-1.25], 0.36 (0.16-0.81) and 0.48 (0.20-1.14) (P for trend 0.038). There was an interaction between central obesity and magnesium : iron ratio.

CONCLUSION

Magnesium : iron intake ratio is an independent risk marker for diabetes in Chinese adults. As this is a cross-sectional study, we cannot establish any causal relationship.

Transglutaminase-catalyzed transamidation: a novel mechanism for Rac1 activation by 5-hydroxytryptamine2A receptor stimulation

Transglutaminase (TGase)-induced activation of small G proteins via 5-hydroxytryptamine (HT)(2A) receptor signaling leads to platelet aggregation (Cell 115:851-862, 2003). We hypothesize that stimulation of 5-HT(2A) receptors in neurons activates TGase, resulting in transamidation of serotonin to a small G protein, Rac1, thereby constitutively activating Rac1. Using immunoprecipitation and immunoblotting, we show that, in rat cortical cell line A1A1v, serotonin increases TGase-catalyzed transamidation of Rac1. This transamidation occurs in both undifferentiated and differentiated cells. Treatment with a 5-HT(2A/2C) receptor agonist 2,5-dimethoxy-4-iodoamphetamine, but not the 5-HT(1A) receptor agonist 5-hydroxy-2-dipropylamino tetralin, increases transamidation of Rac1 by TGase. In A1A1v cells, 5-HT(2A) receptors mediate the transamidation reaction because expression of 5-HT(2C) receptors was not detectable and the selective 5-HT(2A) receptor antagonist blocked transamidation. Time course studies demonstrate that transamidation of Rac1 is significantly elevated after 5 and 15 min of serotonin treatment, but returns it to control levels after 30 min. The activity of Rac1 is also transiently increased following serotonin stimulation. Inhibition of TGase by cystamine or small interfering RNA reduces TGase modification of Rac1, and cystamine also prevents Rac1 activation. Serotonin itself is bound to Rac1 by TGase following 5-HT(2A) receptor stimulation as demonstrated by coimmunoprecipitation experiments and a dose-dependent decrease of serotonin-associated Rac1 by cystamine. These data support the hypothesis that Rac1 activity is transiently increased due to TGase-catalyzed transamidation of serotonin to Rac1 via stimulation of 5-HT(2A) receptors. Activation of Rac1 via TGase is a novel effector and second messenger of the 5-HT(2A) receptor-signaling cascade in neurons.

Microarray analysis of microRNA expression in peripheral blood cells of systemic lupus erythematosus patients

MicroRNAs (miRNAs) are noncoding RNA molecules of 21-24 nt that regulate the expression of target genes in a post-transcriptional manner. Evidence indicates that miRNAs play essential roles in embryogenesis, cell differentiation and pathogenesis of human diseases. This study describes a comparison between the miRNA profile of the systemic lupus erythematosus (SLE) patients and the controls to develop further understanding of the pathogenesis of SLE. Peripheral blood mononuclear cells were isolated from blood samples of 23 SLE patients, 10 idiopathic thrombocytopenic purpura patients and 10 healthy controls. The miRNA microarray chip analysis identified 16 miRNAs differentially expressed in SLE. The chip results were confirmed by northern blot analysis. This work indicates that miRNAs are potential diagnosis biomarkers and probable factors involved in the pathogenesis of SLE.

Activation of fibroblast growth factor receptor by axotomy, through downstream p38 in dorsal root ganglion, contributes to neuropathic pain

The possible involvement of fibroblast growth factor receptor (FGFR) activation in the dorsal root ganglion (DRG) was examined following peripheral nerve injury in the rat. Ligation of the sciatic nerve down-regulated FGFR2, -3 and -4 mRNA; however, the expression of FGFR1 mRNA showed no change. Activation of FGFR was examined by immunohistochemistry using an antibody of the phosphorylated form of FGFR1-4. Ligation of the sciatic nerve produced phosphorylation of FGFR in the L4 and 5 DRG ipsilateral to the injury, starting at 3 days after the lesion and persisting for more than 30 days. Substantial activation of FGFR was observed, mainly in unmyelinated small DRG neurons that co-expressed phosphorylated p38 mitogen-activated protein kinase (MAPK). Continuous intrathecal infusion of the FGFR1 inhibitor, 3-[3-(2-carboxyethyl)-4-methylpyrrol-2-methylidenyl]-2-indolinone, reduced p38 MAPK phosphorylation in the DRG and pain-related behaviors in the partial sciatic nerve model rat without affecting on the activation of spinal glia cells (microglia and astrocyte). In the injured small DRG neurons, activation of FGFR1 may contribute to the generation of neuropathic pain by activating p38 MAPK.

Gene delivery by the hSP-B promoter to lung alveolar type II epithelial cells in LAL-knockout mice through bone marrow mesenchymal stem cells

Tissue damage and inflammation promote bone marrow stem cells (BMSCs) to differentiate into a variety of cell types in residing tissues. BMSCs can stably maintain their plasticity and are an ideal cell population for delivery of therapeutic genes to non-hematopoietic tissues. Using lacZ as a reporter gene, we demonstrated that the lung-specific human surfactant protein B (hSP-B) 1.5-kb promoter is able to deliver the lacZ gene into the lung of lysosomal acid lipase (LAL) gene-knockout (lal-/-) mice by beta-galactosidase staining, flow cytometry and double immunofluorescence staining. Around 10-18% alveolar type II epithelial cells (AT II cells) exhibited positive lacZ gene expression after 8 weeks of BMSC injection in recipient lal-/- mice. The wild-type mice exhibited no expression after the same treatment. BMSCs from hSP-B 1.5-kb lacZ transgenic mice entered and repopulated in lal-/- bone marrow. The study supports a concept that pulmonary inflammation caused by LAL deficiency can trigger BMSC residing in lal-/- bone marrow, migrating into the lung and converting into residential AT II cells. The hSP-B 1.5 kb promoter is an ideal tool to deliver therapeutic genes into AT II cells through BMSCs to cure pulmonary inflammation-triggered diseases.

Distribution and clinical significance of human papillomavirus subtypes in Shenzhen city, People's Republic of China

This study investigated the subtype distribution of the human papillomavirus (HPV) in the patients with condyloma accuminatum (CA) in Shenzhen city, China, and assessed the relationship between different HPV subtypes and cervical neoplasia. Type-specific prevalence and extent of multiple infections were assessed in the genital tract. CA samples collected from the 352 patients in the departments of dermatology and gynecology from the People's Hospital in Shenzhen during 2004-2006, using MY09/11 PCR and reverse dot blot hybridization for genotyping of 9-20 kinds of HPV subtypes. HPV status was studied in relation to the pathologic findings. HPV type diversity was wide. The low-risk HPV subtype 11 and 6 were the main subtypes, and multiple HPV infection rate was about 37% in HPV-positive samples. High-risk HPV (HR-HPV) types (16, 18, 58, 52, and 33) were the main subtypes in the CA of cervix, especially in the advanced stage cervical intraepithelial neoplasia (cervical intraepithelial neoplasia II(+) or above), multiple HR-HPV infection was found in 87% of HPV-positive samples. We conclude that HPV type 6 and 11 were the main subtypes in patients with CA in Shenzhen region, while HPV type 16 and 18 may be one of the main reasons for malignant changes of cervix, but this study cannot prove the association between multiple HPV infection and severity of cervix lesions.

The role of contrast-enhanced ultrasound in planning treatment protocols for hepatocellular carcinoma before radiofrequency ablation

AIM

To evaluate the clinical value of contrast-enhanced ultrasound (CEUS) for patients with hepatocellular carcinoma (HCC) in identifying the tumour number, ablation range and feeding vessels before ultrasound-guided radiofrequency ablation (RFA), and to compare the efficacy of RFA after CEUS with the efficacy of RFA after non-enhanced ultrasonography (US) without contrast medium administration.

MATERIALS AND METHODS

From 2002 to 2005, 81 patients with 110 HCCs underwent CEUS with SonoVue before RFA treatment (group A). Eighty six patients with 112 HCCs who underwent US without contrast enhancement before RFA served as the control group (group B). The average diameters of the lesions in group A and group B were 3.6+/-1.1cm and 3.5+/-1.1cm, respectively. There were no significant differences in clinical data between the two groups. Regular follow-up after treatment was performed using contrast-enhanced computed tomography (CECT). After treatment, complete necrosis was defined as the absence of viable tissue in treated tumours at the 1-year follow-up CECT.

RESULTS

Using CEUS an additional seven small lesions (< or =2.0 cm) were found compared with those found using CECT and conventional US. CEUS showed that 56.4% of lesions (62/110 tumours) were larger in size and 49.1% (54/110 tumours) became more irregular in shape during the arterial phase than on conventional US. Feeding vessels were detected using CEUS in 52 (91.2%) of 57 lesions that were larger than 3.5 cm. The follow-up period was at least 1 year for each case. The complete tumour necrosis rate in group A was significantly higher than that in group B (92.2% versus 83.0%; p=0.036).

CONCLUSION

CEUS can be used to more accurately define the size and contour of lesions, and to detect additional small or satellite lesions and the feeding vessel of HCC tumours. CEUS provided important information for designing the ablation protocol, and might improve the efficacy of RFA.

Nuclear reprogramming in embryos generated by the transfer of yak (Bos grunniens) nuclei into bovine oocytes and comparison with bovine–bovine SCNT and bovine IVF embryos

Although inter-species SCNT may be useful for increasing and preserving populations of endangered species, there are many reports that inter-species nuclear transfer embryos only develop to the blastocyst stage. In this study, yak-bovine SCNT blastocysts were successfully implanted in the surrogate bovine uterus but failed to develop to term or aborted. To clarify the reasons, we examined yak-bovine SCNT blastocyst development, total cell number, inner cell mass (ICM) number, trophoblast (TE) cell number and relative gene expression in yak fibroblast cells and yak-bovine SCNT embryos at various stages. The potential for development of yak-bovine SCNT embryos to blastocysts was 30+/-5.7% (mean+/-S.E.M.); the total cell number was 85.3+/-16.3, fewer than in IVF bovine embryos (106.2+/-18.2) but within the reported range (60-300). The yak-bovine SCNT blastocysts had a lower ratio of TE cells to total cells (43.9+/-8.7%) than bovine IVF embryos (59.4+/-3.4%; P<0.05) or bovine-bovine SCNT (69.5+/-5.4%; P<0.05). Also, several yak-bovine SCNT embryos had abnormal initiation of expression of both Mash2 and IL6. However, expression of vimentin, collagen, Cx43 and PSMC3 were normal in yak fibroblast cells and yak-bovine SCNT embryos. In conclusion, we inferred that the normal allocation of ICM and TE cells in yak-bovine SCNT embryos and embryo-specific gene reprogramming may be important for successful inter-species animal cloning.

Upregulation of leptin pathway correlates with abnormal expression of SERCA2a, phospholamban and the endothelin pathway in heart failure and reversal by CPU86017

Emerging evidence indicates that leptin may be a potential new target in chronic heart failure (CHF) treatment. We hypothesized that hyperleptinemia may correlate with abnormal expression of SERCA2a, PLB (phospholamban), and the endothelin (ET) pathway in CHF. An activated ET pathway is involved in CHF that is suppressed by CPU86017 (p-chlorobenzyltetrahydroberberine chloride), a complex class III antiarrhythmic agent with an antioxidant effect. Thus, relief of CHF may be mediated by a reversal of abnormalities of the leptin system, the ET-reactive oxygen species (ROS) pathway, SERCA2a, and PLB by CPU86017. CHF was produced by coronary artery ligation for 6 weeks in rats. The rats were divided into 3 groups: sham, CHF untreated, and CHF+CPU86017 (4 mg/kg per day, s.c.). Hemodynamic changes, cardiac morphology, serum biochemistry, messenger ribonucleic acid (mRNA) and protein expression of the leptin pathway, ET pathway, and redox were measured. In CHF rats, hemodynamic abnormalities, cardiac remodeling, and histological changes with features of cardiac failure were associated with hyperlipidemia accompanied by oxidative stress and upregulated OB-Rb, ECE, pp-ET-1, ET(A)R, and ET(B)R mRNA expression in the myocardium. Protein expression of leptin and ET(A)R in the myocardium was markedly increased in CHF rats. An activated leptin pathway was associated with downregulation of SERCA2a and upregulation of PLB in mRNA and protein expression in CHF. CPU86017 downregulated the leptin system and reversed the above changes in the myocardium. An activated leptin pathway correlates with abnormal expression of SERCA2a and PLB and an activated ET-ROS system in the affected myocardium. The multi-ion-channel-blocking and antioxidative effects of CPU86017 downregulate the leptin pathway and ET system, resulting in reversal of the abnormalities of expression of SERCA2a and PLB and cardiac performance in CHF.

Glucose regulated proteins 78 protects insulinoma cells (NIT-1) from death induced by streptozotocin, cytokines or cytotoxic T lymphocytes

Endoplasmic reticulum stress-mediated apoptosis plays an important role in the destruction of pancreatic beta-cell, and contributes to the development of type 1 diabetes. The chaperone molecule, glucose regulated proteins 78 (GRP78), is required to maintain ER function during toxic insults. In this study, we investigated the effect of GRP78 on the beta-cell apoptosis. We first measured GRP78 protein expression in different phase of streptozotocin-affected beta-cell by immunoblotting analysis. An insulinoma cell line, NIT-1, transfected with GRP78 was established, named NIT-GRP78, and used to study apoptosis, which was induced by streptozotocin or inflammatory cytokines. Apoptosis of NIT-1 or NIT-GRP78 cells was detected by flow cytometry, the transcription of C/EBP homologous protein (CHOP) was monitored by real-time PCR, the concentration of nitric oxide and the activity of superoxide dismutase were measured by colorimetric method. We found that, in comparison to NIT-1 cells, NIT-GRP78 cells responded to the streptozotocin or cytokines treatments with decreased concentration of nitric oxide, but increased activity of superoxide dismutase. In addition, the level of CHOP was also decreased in the NIT-GRP78 cells, which may mediate the resistance of the GRP78 overexpressed NIT-1 cells from apoptosis. Finally, we found that NIT-GRP78 cells were also more resistant than NIT-1 cells to cytotoxic T lymphocyte (CTL) specific killing detected by flow cytometry through target cells expressing green fluorescent protein cultured with effector cells and finally stained with propidium iodide. The data suggest that modulating GRP78 expression could be useful in preventing pancreatic beta-cell from the immunological destruction in type 1 diabetes individuals.

Impact of antimicrobial usage on antimicrobial resistance in commensal Escherichia coli strains colonizing broiler chickens

Escherichia coli strains isolated from commercial broilers and an experimental flock of chickens were screened to determine phenotypic expression of antimicrobial resistance and carriage of drug resistance determinants. The goal of this study was to investigate the influence of oxytetracycline, sarafloxacin, and enrofloxacin administration on the distribution of resistance determinants and strain types among intestinal commensal E. coli strains isolated from broiler chickens. We detected a high prevalence of resistance to drugs such as tetracycline (36 to 97%), sulfonamides (50 to 100%), and streptomycin (53 to 100%) in E. coli isolates from treated and untreated flocks. These isolates also had a high prevalence of class 1 integron carriage, and most of them possessed the streptomycin resistance cassette, aadA1. In order to investigate the contribution of E. coli strain distribution to the prevalence of antimicrobial resistance and the resistance determinants, isolates from each flock were DNA fingerprinted by enterobacterial repetitive intergenic consensus sequence (ERIC) PCR. Although very diverse E. coli strain types were detected, four ERIC strain types were present on all of the commercial broiler farms, and two of the strains were also found in the experimental flocks. Each E. coli strain consisted of both susceptible and antimicrobial agent-resistant isolates. In some instances, isolates of the same E. coli strain expressed the same drug resistance patterns although they harbored different tet determinants or streptomycin resistance genes. Therefore, drug resistance patterns could not be explained solely by strain prevalence, indicating that mobile elements contributed significantly to the prevalence of resistance.

Amelioration of Graft Ischmia-Reperfusion Injury by Breviscapine in Rat Small Bowel Transplantation

OBJECTIVE

We sought to evaluate the effects of breviscapine to ameliorate graft ischemia-reperfusion (I/R) injury in a rat small bowel transplantation model.

METHODS

Thirty-six recipients were randomly divided into three groups (n = 12): operative controls, in which grafts were implanted immediately after harvesting; an I/R control group with grafts preserved in cold lactated Ringer's solution at 4 degrees C for 4 hours before transplantation; and a breviscapine group wherein the graft was treated in the same way as the I/R control group but breviscapine (25 mg/kg/d) was injected intraperitoneally into both the donors and the recipients for 3 days before the operation of and into the recipients after transplantation. We compared the pathological scores for I/R injury, apoptosis index, and content of malondialdehyde (MDA) in the graft.

RESULTS

Breviscapine diminished the pathological change caused by I/R injury (breviscapine vs I/R control on 24 hours after operation, 1.50 +/- 0.55 vs 2.17 +/- 0.75; P < .05), decreased the apoptotic index (breviscapine vs I/R control at 24 hours after operation, 27.33 +/- 0.167 vs 73.83 +/- 0.077; P < .05), and reduced the graft tissue content of MDA (breviscapine vs I/R control on 24 hours after operation, 1.717 +/- 0.131 vs 3.167 +/- 0.196; P < .05).

CONCLUSIONS

Breviscapine may protect the transplanted small intestine against I/R injury during transplantation in rats.

Nuclear translocation of the calcium-binding protein ALG-2 induced by the RNA-binding protein RBM22

By yeast two-hybrid screening using the calcium-binding protein ALG-2 as bait a new target of ALG-2 was identified, the RNA-binding protein RBM22. In order to confirm these interactions in vivo we prepared fluorescent constructs by using the monomeric red fluorescent protein to label ALG-2 and the enhanced green fluorescent protein to label RBM22. Confocal microscopy of NIH 3T3 cells transfected with either ALG-2 or RBM22 expression constructs encoding fluorescent fusion proteins alone revealed that the majority of ALG-2 was localized in the cytoplasm whereas RBM22 was located in the nucleus. When cells were co-transfected with expression vectors encoding both fusion proteins ALG-2 was found in the nucleus indicating that RBM22 which can shuttle between the cytoplasm and the nucleus may play a role in nuclear translocation of ALG-2. Using zebrafish as a model mRNA homologues of ALG-2 and RBM22 were microinjected into the blastodisc-yolk margin of zebrafish embryos at the 1-cell stage followed by monitoring the fusion proteins during development of the zebrafish. Hereby, we observed that ALG-2 alone evenly distributed within the cell, whereas in the presence of RBM22 the two proteins co-localized within the nucleus. More than 95% of the two proteins co-localized within the same area in the nucleus suggesting a functional interaction between the Ca(2+)-signaling protein ALG-2 and the RNA-binding protein RBM22.

Expression and bioactivity of recombinant human lysozyme in the milk of transgenic mice

Human milk lysozyme is an important protein for innate immunity, but human breast milk is a fairly poor source for commercial production of this enzyme. Research on the expression of recombinant human lysozyme (rHlys) is therefore potentially valuable to the dairy industry. In this study, 2 different kinds of transgenic mice, PBC-hLY and PBC-sighLY, were generated and used as system models to express rHlys. Six lines of PBC-hLY transgenic mice with human lysozyme genomic DNA-based constructs were generated, and a maximum expression level of rHlys approaching 0.154 mg/mL was achieved. Antibacterial activity of the whey from PBC-hLY female transgenic mice was determined by a turbidimetric assay. Results showed that antibacterial activity of the whey was strongly enhanced, and confirmed that rHlys retained full activity. For rHlys to be secreted efficiently into the milk of transgenic mice, 5 lines of mice were also generated, in which the signal peptide DNA of bovine beta-casein was substituted for that of lysozyme in PBC-hLY transgenic mice. Compared with PBC-hLY transgenic mice, both the expression levels of rHlys and the antibacterial activity of the whey were much higher in the PBC-sighLY transgenic mice. The concentration of rHlys in one of these mice amounted to 1.405 mg/mL-3 times higher than the level in human whey. The antibacterial activity of the whey was also 3 times higher than that of human whey. The rHlys from both PBC-hLY and PBC-sighLY transgenic mice had the same antibacterial activity as human milk lysozyme. The effect of the signal peptide and copy numbers of the transgene on expression of rHlys was also evaluated. This work will certainly permit a better understanding of how mammary gland bioreactor systems can be applied to produce rHlys in other mammals, such as cattle.