The main commercial production of fructooligosaccharides (FOS) comes from enzymatic transformation using sucrose as substrate by microbial enzyme fructosyltransferase. A fructosyltransferase genomic DNA was isolated from Aspergillus niger QU10 by PCR. The nucleotide sequence showed a 1 941 bp size, and has been submitted to GenBank (KF699529). The cDNA of the fructosyltransferase, containing an open reading frame of 1 887 bp, was further cloned by RT-PCR. The fructosyltransferase gene from Aspergillus niger was functionally expressed both in Escherichia coli and Pichia pastoris GS 115. The highest activity value for the construction with the α-factor signal peptide reached 431 U/mL after 3 days of incubation. The recombinant enzyme is extensively glycosylated, and the active form is probably represented by a homodimer with an apparent molecular mass of 200 kDa as judged from mobility in seminative PAGE gels. The extracellular recombinant enzyme converted sucrose mostly to FOS, mainly 1-kestose and nystose, liberating glucose. FOS reached a maximal value and represented about 58% of total sugars present in the reaction mixture after 4 h reaction. The results suggest that the availability of recombinant Pichia pastoris as a new source of a FOS-producing enzyme might result of biotechnology interest for industrial application.
Aspergillus niger ; enzymology ; genetics ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; Escherichia coli ; Fungal Proteins ; genetics ; metabolism ; Glycosylation ; Hexosyltransferases ; genetics ; metabolism ; Molecular Sequence Data ; Molecular Weight ; Pichia ; Sucrose ; metabolism ; Trisaccharides ; metabolism

Purpose Changes of hepatic perfusion and volume of normal adults living at different altitudes are investigated with hepatic perfusion imaging using multi-slice spiral CT to explore the perfusion status of normal human liver in hypoxia condition, and to provide the basis for the diagnosis and treatment of liver diseases. Materials and Methods Sixty volunteers were divided into three groups according to altitude:22 cases in group A with altitude from 2260 to 3100 meters, 20 cases in group B with altitude from 3260 to 4100 meters, and 18 cases in group C with altitude from 4260 to 5260 meters, time-density curves within the ROI was drawn with hepatic hilar region as the center, and hepatic artery perfusion (HAP), portal vein perfusion (PVP), total hepatic perfusion (TLP), hepatic arterial perfusion index (HPI) were calculated using deconvolution method;and point circle method was used to measure the volume of liver manually. Results HAP of group A, B, C were (10.50±3.62) ml/(100 ml · min), (15.03±4.27) ml/(100 ml · min) and (18.39±7.20) ml/(100 ml · min) respectively, and there was significant difference between group A and group C (P<0.05);PVP of three groups were (138.78±14.29) ml/(100 ml · min), (80.42±16.80) ml/(100 ml · min), and (63.78±7.79) ml/(100 ml · min) respectively, signiifcant differences (P<0.05) can be detected for the comparison between each two of them; TLP of the three groups were (149.30±15.55) ml/(100 ml · min), (95.57±18.75) ml/(100 ml · min) and (82.19±10.56) ml/(100 ml · min) respectively, statistically signiifcant differences (P<0.05) can also be found for the comparison between each two of them. HPI of the three groups were 7.00±2.17, 16.27±4.22 and 22.05±7.90 respectively, statistically signiifcant differences (P<0.05) were observed for the comparison between each two of them;liver volume of the three groups were (1173.5±155.2) cm3, (1282.9±362.2) cm3 and (1525.4±352.2) cm3, difference between group A and group C was statistically signiifcant (P<0.05). Conclusion Liver perfusion can be affected by altitude, with the altitude increasing, HAP and HPI will also raise gradually, while PVP and TLP will decrease accordingly, indicating that hypoxia environment due to high altitude will do certain damage on the liver. MSCT perfusion imaging is able to relfect the hemodynamic changes of liver, thus is useful in clinical diagnosis and treatment of liver diseases.

Objective To analyze quantitatively the histological components, and to observe the morphological changes of the transition zone in benign hyperplastic prostates (BPH) and adult normal prostates. Methods The quantitative morphometry of 40 BPH specimens obtained from suprapubic transvesical prostatectomy and 10 normal prostatic specimens (controls) were performed with computer-assisted image analysis system,and all the samples were stained with hematoxylin and eosin (HE) and the Masson trichrome.The area percentages of stromal (smooth muscle and connective tissue),glandular epithelial and luminal components,the average areas of acini,lumens and epithelia,and the heights of epithelial cells were quantitated,respectively. Results ①The mean area percentages of different components between control group and BPH group were as follows: smooth muscles,(23.83?8.53)% vs (35.35?8.33)% ( P 0.05);epithelia,(26.26? 7.45)% vs (17.76?4.61)% (P0.05).②The average areas of acini, epithelia and lumens of control group and BPH group were ( 0.087?0.028)mm 2 vs (0.062?0.030)mm 2 (P

Objective To investigate renal tissue changes in rats exposed to 16 Hz/130 dB infrasound.Methods Twenty male Sprague-Dawley adult rats were randomly divided into a control group,a pseudo-infrasound group,and two infrasound groups-A and B.Groups A and B were exposed to 16 Hz/130 dB infrasound for 2 h or4 h daily respectively over 7 days.Pathological and uhrastruetural changes in their renal tissues were observed with a light microscope and an electron microscope.Results Under the light microscope,Bowman's capsules expanded,epithelial cells were shed,and a little secretion was found in the renal tubules of infrasound group A.Slight degeneration and necrosis of the renal tubules and glomerular exudation could be observed in group B.Under the electron microscope,a large number of lysosomes displayed hyperplasia,there was interstitial edema,and leukocyte pavementing wag found in group B.Other changes such as swelling of podocytes' processes,fusion of foot processes,and vacuolization in the mitochondria could be observed in both infrasound groups.Conclusion Lengthy exposure to 16 Hz/130 dB infrasound can cause severe pathological and uhrastruetural changes in renal tissue,at least in rats.

In this study, we investigated the mechanism of transformation by Bacillus subtilis strain 168 by proteomic analysis. B. subtilis strain 168 was able to stereoselectively transform cis-propenylphosphonic acid (cPPA) to fosfomycin. The maximal fosfomycin production was 816.6 microg/mL after two days cultivation, with a conversion rate of 36.05%. We separated the whole cellular proteins by two-dimensional gel electrophoresis (2-DE) method, and 562 protein spots were detected in the presence of cPPA in the medium, while 527 protein spots were detected in the absence of cPPA. Of them, 98 differentially expressed protein spots were found. Among them, 52 proteins were up-regulated whereas 20 were down-regulated in the presence of cPPA in the medium, and 26 induced at the presence of cPPA. The differentially expressed proteins were analyzed by combined MS and MS/MS methods. Eighty protein spots, including 45 up-regulated proteins, 17 down-regulated proteins, and 18 induced by cPPA were identified. Based on the results of proteomic analysis, we postulated two steps of transformation: in the first step, cPPA was hydrated to 2-hydroxypropylphosphonic acid; in the second step, 2-hydroxypropylphosphonic acid was transformed to fosfomycin via a dehydrogenation reaction.
Bacillus subtilis ; genetics ; growth & development ; metabolism ; Bacterial Proteins ; metabolism ; Biotransformation ; Fosfomycin ; metabolism ; Organophosphorus Compounds ; metabolism ; Proteome ; metabolism ; Proteomics

In this paper, with B/S application and architecture, an integrated solution of PACS is designed, and the function and application of each part of PACS based on the architecture is introduced. The PACS based on this mode is safe, stable, easy to manage and upgrade and convenient for use in telemedicine.
Computer Systems ; Humans ; Radiology Information Systems ; Research ; Software ; Telemedicine

In order to stimulate the patients' active participation in the process of robot-assisted rehabilitation training of stroke patients, the rehabilitation robots should provide assistant torque to patients according to their rehabilitation needs. This paper proposed an assist-as-needed control strategy for wrist rehabilitation robots. Firstly, the ability evaluation rules were formulated and the patient's ability was evaluated according to the rules. Then the controller was designed. Based on the evaluation results, the controller can calculate the assistant torque needed by the patient to complete the rehabilitation training task and send commands to motor. Finally, the motor is controlled to output the commanded value, which assists the patient to complete the rehabilitation training task. The control strategy was implemented to the wrist function rehabilitation robot, which could achieve the training effect of assist-as-needed and could avoid the surge of assistance torque. In addition, therapists can adjust multiple parameters in the ability evaluation rules online to customize the difficulty of tasks for patients with different rehabilitation status. The method proposed in this paper does not rely on the information from force sensor, which reduces development costs and is easy to implement.