Comparison of Signal Peptides for Two Hemicellulase Secretory Expression / 中国生物工程杂志

Xylanase and mannanase are two hemicellulases,which are widely used in many fields.To improve the expression of thermostable xylanase DSB and thermostable mannanase ManA in Pichia pastoris,three endogenous signal peptides of Pichia pastoris(Scw1 1,Dse4 and Exg1) were chosed.Their capability to mediate the secretion of DSB and ManA with that of the Saccharomyces cerevisiae α-factor were compared.In shake-flask cultivation,three endogenous signal peptides and α-factor efficiently mediated the secretion of DSB and ManA,but the secretion efficiency has obvious difference.As for DSB,the expression efficiency of α-factor was much higher than three endogenous signal peptides.But as for ManA,the expression efficiency of Dse4 was equal to α-factor and much higher than Scw11 and Exg1.Therefore,α-factoris the most efficient signal peptide for DSB expression and Dse4 or α-factor are the most efficient signal peptide for ManA expression in Pichia pastoris X33.Moreover,the intracellular activities of DSB and ManA by α-factor are higher than Scw1 1,Dse4 and Exg1,and the intracellular activity of ManA was higher than DSB (the molecular weight of ManA was larger than DSB).Thus,when ManA were expressed in Pichia pastoris,different signal peptide,such as Dse4,could be used for improving the secretion efficiency.A basis for identifying more available signal peptides and screening for the optimal signal peptide for the target protein was provided.

The thoracic CT manifestations and pathologic basis of pulmonary Wegener granulomatosis / 中国医师进修杂志

Objective To explore the thoracic CT manifestations and pathologic basis of pulmonary Wegener granulomatosis (WG),in order to improve the diagnostic accuracy.Methods Eighteen patients with pulmonary WG confirmed by pathology were collected.All the patients underwent CT scan and enhanced scan with 64-slice volume CT.CT features and clinical symptoms were retrospectively reviewed.Results The pathological manifestations of 18 cases with pulmonary WG were miscellaneous,including necrotizing granuloma infiltrated with inflammatory cells,intrapulmonary vasculitis,parenchymal necrosis,hemorrhage of pulmonary alveolus,microabscess and so on.Thoracic CT manifestations:multiple nodules were seen in 7 cases,multiple masses were detected in 4 cases,cavitations showed in 10 cases,peripheral wedge-shaped shadows showed in 2 cases,ground-glass attenuation and consolidation showed in 2 cases,bronchial wall thickening in 2 cases,solitary pulmonary nodule or mass in 3 cases,pleural effusion was seen in 5 cases.All the nodules,masses and cavitations demonstrated inhomogeneous and ring enhancement on contrast-enhanced images.Some patients presented with varied kinds of the above lesions,which could transform each other and became more or less.Conclusions Pulmonary WG has many pathological manifestations,resulting in the variety of the thoracic CT manifestations.The main manifestations are multiple nodules and multiple masses,necrotic cavitations.The feeding vessel sign to a nodule or mass and ring-shade cavity are relatively characteristics to diagnose pulmonary WG.The correct diagnosis could be established on the bases of understanding of the special developments and pathology of the lesions.

Diagnostic Value of Low-field MR Imaging in Lumbar Disc Degeneration with End-Plate Osteochondritis / 实用放射学杂志

Objective To investigate the diagnostic value of low-field MR imaging in lumbar disc degeneration with end-plate osteochondritis. Methods Imaging data of 504 patients with lumbar disc degeneration diagnosed by MRI were retrospectively analyzed. Among these cases, the total of 330 end-plate osteochondritis in 148 patients was found. According to MR signal findings of end-plate and it's adjacent vertebra, the lesions were classified as 4 types. Results 330 end-plates were involved in 148 patients,including type I in 68(20.6%),type II in 53(16.1%),type III in 174(52.7%) and type IV in 35(10.6%).Among all 148 patients,the end-plates at one lumbar disc,two disci and over three disci involved in 98(66.2%),42(28.4%) and 8(5.4%),respectively.The lesions were usually found in the lower lumbar vertebra.Conclusion MR imaging could accurately show the end-plate osteochondritis and degenerative lumbar disc.

Oxidative Damage of Respiratory System in Rats Exposed to Carbon Nanotubes / 环境与健康杂志

Objection To explore the oxidative damage of respiratory system in rats exposed to carbon nanotubes(CNTs) . Methods Twelve Wistar rats were randomly divided into two groups(the treated group and the control group) and exposed to CNTs through intratracheal instillation at the dose of 22.5 mg/kg(calculated with CNTs) once a day for 15 days,then the rats were sacrificed,the biochemicaly indexes in serum and bronchoalveolar lavage fluid(BLAF) were measured. Results The results showed that CNTs could cause decrease of body weight gain,even after three days of stoping exposure to CNTs. Compared with the control group,the activity of superoxide dismutase(SOD) and total antioxidant capacity(T-AOC) in serum and BLAF of exposed rats decreased,the level of malondialdehyde(MDA) in serum and BLAF increased significantly. Conclusion CNTs exposure can induce the decrease of the antioxidant capacity and oxidative damage of respiratory system in rats.

Analysis of Multi-Detector-Row Spiral CT Signs in Inflammatory Diseases in Retroperitoneal Space / 中国普外基础与临床杂志

Objective By using multi detector row spiral CT (MDCT), to investigate the CT imaging features of inflammatory diseases in retroperitoneal space with correlation of radiological anatomy.Methods The clinical and laboratory dada of 30 patients with proven inflammatory diseases of retroperitoneal space were collected. All patients underwent MDCT plain scanning and portal venous acquisition. CT imaging data generated at portal venous phase were processed with coronal, sagittal and oblique multi planar reformation (MPR) technique.Results Acute pancreatitis and various types of renal infection were the two main sources of retroperitoneal inflammation. Depending on the specific anatomic locations, retroperitoneal inflammation of different subspaces demonstrated characteristic imaging features. Spreading of inflammatory process across subspaces was also quite common.Conclusion MDCT is the imaging method of choice to depict comprehensively and clearly the inflammatory diseases of various retroperitoneal spaces.

The measurement of the posterior condylar angle in distal femur with clinical application in adult / 中华骨科杂志

Objective To investigate the posterior condylar angle(PCA) of distal femur in normal adult, and provide reasonable referenced parameters of the rotational alignment for the total knee arthroplasty in Chinese. Methods This study concluded 118 volunteers(186 knees) in Suwan area (67 males 103 knees, and 51 females 83 knees), whose knees were healthy, without any malformation. The average age was 39.7 years(range, 18-69 years). All subjects were divided into three groups according to the ages: group A, 18-39 years (85 knees); group B, 40-59 years(73 knees); group C, more than 60 years(28 knees). The CT scan was employed to the mechanical axis which was perpendicular to the knee joint in the distal femur. The PCA was measured from the CT film across lateral and medial femoral epicondyle. The factorial design was used to compare the data among three groups. Results First, in the 103 knees of male, 57 in left side and 46 in right side. The PCA were 5.9??1.6? in left side, 5.6??2.6? in right side(mean, 5.8??2.2?). Then in the 83 knees of female, 38 in left side and 45 in right side, the PCA was 5.5??2.5? in left side, 5.2??1.5? in right side(mean, 5.3??1.9?). And the PCA was 5.5??1.9? in group A, 5.7??1.8? in group B, 5.5??2.7? in group C, respectively, and there is no statistical significant difference in either gender or side and age. Conclusion The normal adult PCA of distal femur is 5.6??2.1? in Suwan area, without difference in gender, which is beyond the Westerns obviously. So in the total knee arthroplasty of Chinese, the malalignment will likely occur if the rotational alignment is performed according to Western style, the eversion 3? to the posterior condylar line in distal femur.

Pulmonary Toxicity of Three Typical Nanomaterials on Rats / 环境与健康杂志

Objective To investigate the toxic effect of lung and mechanism induced by silver nanoparticles(Nano-Ag),zinc oxide nanoparticles(Nano-ZnO)and titanium dioxide nanoparticles(Nano-TiO2) on rats.Methods Forty-two Wistar rats were divided into 7 groups randomly,including the control group,low(3.5 mg/kg) and high(17.5 mg/kg) dose groups of three nanomaterials.The rats were exposed by intratracheal instillation once two days for 5 weeks,and then killed by abdominal aorta bloodletting.The pathological examinations of rat lungs were performed,malondialdehyde(MDA),superoxide dismutase(SOD),reduced glutathione(GSH),nitrogen oxide(NO),interleukin-1(IL-1),interleukin-6(IL-6),tumor necrosis factor-?(TNF-?) and macrophage inflammatory protein(MIP-2) in bronchoalveolar lavage fluid(BALF) were detected.Results The results of histopathological analysis indicated that the fibrous tubercle,pulmonary alveoli destruction and the matrix inflammation of lung tissue appeared in the exposure groups.The activities of SOD in three kinds of nanoparticles groups(except for Nano-TiO2 subgroup) significantly decreased(P

The Value of Low-field MR Imaging in Diagnosing Avascular Necrosis of the Femoral Head / 实用放射学杂志

Objective To analyze MR imaging findings of avascular necrosis of the femoral head(ANFH)with low-field MR unit.Methods MRI appearances of 35 cases of ANFH confirmed by clinical or pathology were analysed.Results There were 56 hips with "line sign" in 35 cases(58 hips)including "single line sign" in 18 femoral heads and "double line sign" in 38,and there were 2 hips without "line sign".Twenty-six femoral heads had marrow edema.According to Mitchell's grade:there were 15 hips in A grade,21 hips in B grade,13 hips in C grade and 9 hips in D Grade.Conclusion Low-feild MR imaging is of significant value in diagnosing ANFH early.