A novel biosensor for aflatoxin B1 detecting has been reported. The biosensor electrode for AFB1 detecting was assembled by immobilized aflatoxin-oxidoreductase using open-ended multi-walled carbon nanotubes as matrix. Its linear range was between 0.16?M and 3.2?M. And if the specific anti-aflatoxin B1 antibody and aflatoxin oxidoreductase were both immobilized on the electrode with Multi-Walled carbon nanotubes, the detection limit of the modified electrode could be 16 nM with a 10 times improved sensitivity. The aflatoxin enzyme biosensor assembled this way strode one step forward its practical application.

Objective Intranuclear forkhead/winged helix transcription factor p3(Foxp3) plays a key role in T cell-mediated immunosuppression.The present study was performed to investigate the effects of high mobility group box-1 protein(HMGB1) on Foxp3 gene as well as protein expressions in splenic regulatory T cells(Tregs) and their potential regulating mechanisms in mice.Methods CD4+CD25+Tregs isolated from the spleens of male BABL/c mice by magnetic beads were seeded on 96-well(1?105 cells/well) cell culture plates coated with anti-CD3(1 ?g/ml) and soluble anti-CD28(1 ?g/ml),and the cells were stimulated with HMGB1 at various intervals or at different concentrations.After being stimulated,the Foxp3 mRNA/protein expressions in the Tregs were determined.The time-dependent and dose-dependent responses between HMGB1 and intranuclear Foxp3 expression were analyzed by flow cytometry,and the expressions of Foxp3 mRNA of Tregs were analyzed by quantitative PCR of SYBR GREEN.Results After stimulation with HMGB1,the intranuclear Foxp3 protein and mRNA expressions of splenic Tregs in mice were markedly down-regulated in 24 h to 72 h(P

Objective Thoracic cavity fistula following esophagus carcinoma resection is a serious complication with a high mortality.This study aims at a better therapy for thoracic cavity fistula following esophagus carcinoma resection by summarizing the ex-perience with the four-tube strategy ( jejunal fistula tube, stomach tube, chest drainage tube, and nasal fistula tube) in the treatment of the complication. Methods We retrospectively analyzed the clinical data about 62 cases of thoracic cavity fistula following esopha-gus carcinoma resection, 35 treated with the four-tube strategy ( treatment group) and the other 27 with the three-tube ( stomach tube, chest drainage tube, and nasal fistula tube) method ( control group) .We compared the hospital days, wound healing time, mortality, and incidence of anastomotic stenosis at 6 months after operation between the two groups of patients. Results Compared with the controls, the treatment group showed remarkable decreases in the hospital days (P<0.05), wound healing time (P<0.05), and mortality (P<0.05), but no statistically significant difference was observed in the incidence rate of anastomotic stenosis at 6 months after operation between the two groups of patients ( P >0.05 ) . Conclusion Compared with the three-tube method, the four-tube strategy has the advantages of shorter healing time and lower mortali-ty, and therefore is preferable for the treatment of thoracic cavity fis-tula following esophagus carcinoma resection.

Objective To observe the expression law of cytokine signaling suppressors (SOCSs) mRNA in burn rats with Staphylococcus aureus sepsis and investigate their potential role in the pathogenesis of postburn sepsis. Methods Wistar rats were inflicted with 20% TBSA Ⅲ? scald, followed by Staphylococcus aureus challenge. Then, the expressions of SOCS1, SOCS2 and SOCS3 mRNA and interferon-? (IFN-?) levels in the liver and lungs were determined. Results With Staphylococcus aureus challenge after burn, IFN-? levels in the liver and lungs were significantly elevated and reached peak at the 0.5th and 6th hours, respectively (P

Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )

SMART-RACE was performed after isolating the total RNA of Armillariella tabescens to amplify the full-length cDNA of arabinosidase (GenBank Accession No. AJ620046). Bioinformatics analysis was used to analyze the code frame of arabinosidase, to predict its structure and function. Recombinant plasmid pPIC9-AF was constructed and then electroporated into methylotrophic yeast Pichia pastoris GS115. The secreted 6 ? His fusion protein was purified to analyze its enzymology property. This arabinosidase had high activity at 30-35℃ under acid condition, and was stable within wide range of pH and temperature. It maintained about 80% activity at the range of pH4. 0-8.0 and 20-40℃,wider than many other cloned arabinosidase. So it was worthy to go step further to study this enzyme, and recombinant expression provided a chance of highly expressing arabinosidase.

Armillariella tabescens EJLY2098 was capable of secreting p-mannanase by konjac inducement. A 34 orthogonal design was applied to determine the optimum medium of inducing mannanase by Armillariella tabescens EJLY2098. The results suggested that Armillariella tabescens EJLY2098 secreted the high-activity enzyme in the optimum medium, which was composed of 2% konjac, 1% peptone, 25% potato juice,0.3% KH2PO4,15% MgSO4?7H2O, 0.01% VitB1. Purified by DEAE-anion exchange chromatography, two eluting peaks (P1 and P2) with the p-mannanase activity were obtained, and one of them (named?-mannanase P2) was a single band by the SDS-PAGE, and the molecular weight of?-mannanase P2 was 78. 9kDa. The isoelectric point of?-mannanase P2 was estimated to be 4.0-4. 1. The optimum activity for the enzyme was found at 60℃and pH4. 0 - 6. 0, and the enzyme was stable between pH4. 5 - 6. 0. The activity of?-mannanase P2 were enhanced by Na+ and Ba2+ . This?-mannanase can be used in feed industy. a new fungi secreting?-mannanase was obtained, providing an important base for cloning mannanase gene and constructing recombin microbe expressing?-mannanase .

Armillariella tabescens EJLY2098 was induced to produce ?-mannanase with konjac fine flour (Amorphopallus rivieri) as single carbon source. This induced enzyme was then purified using DEAE ion exchange chromatography and named atMAN47. Zymologic analysis showed that the molecular weight of this ?-mannanase was approximately 47 kD. The enzyme was stable when pH ranged from 5.0 to 6.5 and could be activated by Na+ and Ba2+. With an optimal temperature of 50?C. Action mode analysis of TLC revealed that the enzyme belonged to the endo-?-mannanase family. Being a meta-acid endo-?-mannanase, it was suitable to be applied to feed industry with a promising future as an enzyme preparation.

Objective To investigate the diagnostic value of the recombinant surface antigen 1 (rSAG1) in immunodiagnosis of toxoplasmosis. Methods Isopropyl β-D- 1 -thio-galaetopyranoside (IPTG) was used to induce the expression of recombinant plasmid pET28a-SAG1 of Escherich coli(pET28a-SAG1/BL21 ). The expression products (rSAG1) of pET28a-SAG1/BL21 were identified by Western blotting. The serum of mice infected with Toxoplasma gondii tachyzoites, normal mouse serum and the serum from 10 toxoplasma gondii patients were used as primary anti-Toxoplasma gondii antibodies, and the rSAG1 gene products were identified by Western blotting, by which the diagnostic value of rSAG1 in Toxoplasmosis was compared. Results After induction and purification, rSAG1 protein was obtained and its relative molecular mass was 38.5 × 103. The fusion protein could be recognized by the serum of mouse infected with Toxoplasma gondii tachyzoites, rSAG1 of expression products of surface membrane antigen SAG1 gene from Toxoplasma Gondii could be detected in 4 cases from 10 patients by Westem blotting.Conclusion The rSAG1 has a potential value in the immunodiagnosis of Toxoplasmosis.

Objective To investigate the immunological activity change of regulatory T cells (Treg) and discuss its significance in the outcomes of patients with multiple organ dysfunction syndrome (MODS) and severe burn. Methods A total of 106 patients with total burn surface area (TBSA) larger than 30% were included in the study and randomly divided into three groups according to the burn area: Group Ⅰ (TBSA of 30%-49%, n = 41), Group Ⅱ (TBSA of 50% -69%, n = 34) and Group Ⅲ (TBSA of 70%-99%, n = 31). According to the development of MODS, patients were divided into MODS group (n =21) and non-MODS group (n =85). The patients with MODS were further divided into non-survival group (n = 16) and survival group (n = 5) based on their outcomes. Healthy volunteers were served as normal control (n = 25). Peripheral blood samples were collected at days 1,3,7, 14 and 21 postburn. The immunomagnetic separation technique was applied to separate and purify CD4+ CD25+Tregs in peripheral blood, and phenotypes (CTLA-4) were analyzed by flow cytometry and the contents of interleukin-10 released in the supernatants were determined by ELISA. Results Expression of CTLA-4 and level of IL-10 were significantly increased in burn patients compared with normal control group, with statistical differences. The expression of CTLA-4 and level of IL-10 were significantly increased in patients with severe burns at all time points. The expression of CTLA-4 and level of IL-10 in MODS group were much higher than those in non-MODS group at days 3-21 postburn (P ＜ 0.01). Among the MODS patients, the expression of CTLA-4 and level of IL-10 in the survival group were obviously lower than those in the non-survival group at days 3-21 postburn (P ＜ 0.05 or P ＜ 0.01). Conclusions After severe burn injury, expressions of the markers on CD4 + CD25 + Treg surface and secretion of cytokines produced by CD4 + CD25 + Tregs show significant difference in patients with different born areas, MODS development and survival state. CD4 + CD25 + Treg may play an important role in the pathogenesis of immunoregulation, MODS and mortality of burn patients through secretion of inhibitory cytokines.