Ethyl carbamate (EC) is a carcinogenic substance in many fermented foods. Enzymatic removal of ethyl carbamate from fermented foods is an important way to eliminate its potential health damage to consumers. To study the enzymatic properties of an ethyl carbamate hydrolase (urethanase) from Klebsiella pneumoniae, a strain isolated from murine somach, we purified the enzyme using ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography. The molecular mass of this enzyme was estimated to be 55 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its K(m) was 74 mmol/L when EC was used as the substrate. Moreover, its optimal reaction temperature was 55 degrees C, and the optimum pH was 7.0. The activity was enhanced by ethylene diamine tetraacetic acid (EDTA) and dithiothreitol (DTT), but strongly inhibited by Cu2+ and Zn2+. The enzyme was halophilic and tolerant to low concentration of ethanol. Therefore, it has the potential to remove EC from fermented foods.
Amidohydrolases ; chemistry ; isolation & purification ; Bacterial Proteins ; chemistry ; isolation & purification ; Chromatography, Gel ; Chromatography, Ion Exchange ; Electrophoresis, Polyacrylamide Gel ; Hydrogen-Ion Concentration ; Klebsiella pneumoniae ; enzymology ; Molecular Weight ; Substrate Specificity ; Temperature

A mathematical model of competition-type lateral flow immunoassay (LFIA) was developed to describe the dynamic process of LFIA.The competition-type LFIA was divided into two categories: TwA-competition-type LFIA and TnA-competition-type LFIA.On the basis of the developed model, the COMSOL software was exploited to simulate the dynamic process of LFIA.The simulation result demonstrated the relationships between the concentrations of substances on the test and control lines and the influence factors.In particular, the influence factors in the TwA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the position of the test line (5-20 mm).On the other hand, the influence factors in the TnA-competition-type LFIA included the concentrations of target analyte A (0-20 mol/L) and reporter particle P (0.01-100 mol/L), and the porosity.Experiment result showed that the developed model could be used to explore the influence of the parameters on the test results, and optimize the performance of LFIA.

Abstract: The activities of four CYP450 enzymes (CYP3A, 1A2, 2El and 2C) and the mRNA expression levels of CYP1A2, 2El, 2Cll and 3A1 in rat liver were determined after Wistar rats were orally administered with brucine (BR) at three dosage levels (3, 15 and 60 mg.kg-1 per day) and the high dose of BR combined with glycyrrhetinic acid (GA, 25 mg.kg-1 per day) or liquiritin (LQ, 20 mg.kg-1 per day) for 7 consecutive days. Compared with the control, brucine caused 24.5% and 34.6% decrease of CYP3A-associated testosterone 6beta-hydroxylation (6betaTesto-OH) and CYP2C-associated tolbutamide hydroxylation (Tol-OH), respectively, and 146.1% increase of CYP2El-associated para-nitrophenol hydroxylation (PNP-OH) at the high dose level. On the other hand, (BR+GA) caused 51.4% and 33.5% decrease, respectively, of CYP2El-associated PNP-OH and CYP1A2-associated ethoxyresorufin-O-de-ethylation (EROD) as compared with the high dose of BR group. Meanwhile, (BR+LQ) caused 41.1% decrease of CYP2El-associated PNP-OH and 37.7% increase of CYP2C-associated Tol-OH. The results indicated that the co-administration of BR with GA or LQ had effect on mRNA expression and activities of the CYP450 enzymes mentioned above to some extent, and the in vivo antagonism of LQ on BR-induced CYPs adverse effects and the in vivo inhibitory action of GA on CYP2E1 and 1A2 might play an important role in the detoxification of Radix Glycyrrhizae against Strychnos nux-vomica L.

This paper carries out the multi-scale decomposition of pulse signals on different frequency bands by wavelet transform, and the analysis of power spectral density shows that the detailed signal energy of the fourth layer mainly concentrates on the 3-5 Hz, while the energy of the fifth layer concentrating on the 1-3 Hz. Through calculating the energy, the experimental results show that: the hypertension signal energy of 3-5 Hz band increases significantly, compared with the normal signals.
Hypertension ; physiopathology ; Signal Processing, Computer-Assisted ; Wavelet Analysis

Hypertension, as one of diseases with the highest incidence in the world at present, is an important cause of stroke, coronary heart disease, renal insufficiency and other serious diseases. Based on pseudo Wigner-Ville distribution, this paper makes an analysis on the relevant pulse characteristics by measuring time range of the energy concentration circle. In view of the present situation, that is, about half of the high-normal blood pressure persons are likely to develop hypertension, we explored the pulse characteristics to find the pathological changes in subjects with prehypertension, in order to solve the problems that there are no obvious clinical significant features in prehypertension. The results showed that the duration of high energy circle in signal with hypertension pathological changes was shorter than the duration of healthy signal. Hence, healthy signal and hypertension pathological signal can be effectively distinguished by this method, and this provides a new basis to identify the lesion signal when blood pressure is in critical period.
Adult ; Algorithms ; Arterial Pressure ; physiology ; Female ; Humans ; Hypertension ; pathology ; physiopathology ; prevention & control ; Male ; Middle Aged ; Pulse ; Signal Processing, Computer-Assisted

OBJECTIVE:To study the improvement effects of citalopram combined with huperzine A in aged depression model rats. METHODS:Aged rats were randomly divided into blank control group,model group,huperzine A group(0.3 mg/kg),citalo-pram group(5 mg/kg),and combination group(huperzine A 0.3 mg/kg+citalopram 5 mg/kg),10 in each group. Except for blank control group,rats in other groups received chronic unpredictable mild stress to reduce depression model. After modeling,rats were intragastrically administrated relevant drugs once a day,for 2 weeks. The depression,learning and memory behavior changes of rats in each group were observed by using open-field test,sucrose consumption test,tail suspension test,forced swimming test and Morris water maze test. RESULTS:Compared with blank control group,the horizontal crossing number,uprightness number,su-crose preference rate,crossing number in platform,percentages of target quadrant distance and time of rats in model group were ob-viously decreased (P<0.05 or P<0.01);immobility time of tail suspension and swimming,escape latency were obviously pro-longed(P<0.05 or P<0.01). Compared with model group,the depression-related indexes of rats in citalopram group and combina-tion group were obviously improved(P<0.05 or P<0.01),and combination group had better effects;the learning and memory-re-lated indexes in combination group were obviously improved(P<0.05 or P<0.01),only crossing time in platform in huperzine A group and citalopram group were obviously increased (P<0.05 or P<0.01),and other learning and memory-related indexes had no obvious changes(P>0.05). CONCLUSIONS:Citalopram combined with huperzine A can obviously improve the depression be-havior,learning and memory ability of aged rats with depression,showing better effects than citalopram alone.

Objective:To seek specific response points on the body surface of patients with primary dysmenorrhea(PD)by observing blood perfusion unit(PU)at different points of the three Yin meridians of foot using laser speckle contrast imaging(LSCI). Methods:Eighty PD patients were recruited as a PD group,and 80 healthy female undergraduates were taken as a normal group.During one menstrual cycle(before menstruation,during menstruation,and 3 d after menstruation),each participant was examined using the LSCI system to determine PU at bilateral Taixi(KI3),Taibai(SP3),Taichong(LR3),Shuiquan(KI5),Diji(SP8),Zhongdu(LR6),Sanyinjiao(SP6),and Xuehai(SP10)and non-acupuncture points.The researchers in charge of point location,operation,and statistical analysis were not aware of grouping.PU at the detection spots was taken as the outcome measure. Results:Compared with the normal group,the PD group showed increases in PU at right Taixi(KI3)before menstruation(P<0.05)and at bilateral Zhongdu(LR6)and right Diji(SP8)during menstruation(P<0.05).At the other time points,significance was not found between the two groups in comparing PU at the detected spots. Conclusion:Compared with healthy participants,PD patients present specific changes in PU at Taixi(KI3),Diji(SP8),and Zhongdu(LR6)at specific time points during the menstrual cycle,which provides a reference for acupuncture-moxibustion treatment of PD in clinical settings.

Objective To investigate the antimicrobial resistant mechanisms of high level carbapenem resistant Klebsiella pneumoniae infection of burn patients .Methods A retrospective study was conducted on totally 18 non-repetitive high level CR-KP which were isolated from burn patients hospitalized between July 2014 and June 2015.MIC of antibiotics were determined by using the GN 13 cards and agar dilution method.The specific PCR and DNA sequence analysis were performed to confirm the β-lactamase type.Plasmid conjugation transfer experiments and southem hybridization were applied to study the mode of carbapenem resistance transmission .Outer membrane proteins ( Omps) were isolated and examined by PCR and ( sodium dodecyl sulfate polyacrylamide gel electrophores ) SDS-PAGE.Pulsed-field gel electrophoresis( PFGE ) and Multilocus sequence typing ( MLST ) was used to determine the genotypes . Results Susceptibility of antimicrobial agents indicated that all these strains with multiple drug resistance . The resistance rate to piperacillin/tazobactam, ceftriaxone, levofloxacin, ciprofloxacin, gentamicin, tobramycin, cefotetan, ceftazidime, cefepime, aztreonam, imipenem, and meropenem was 100％ (18/18).Moreover, the resistance rate of CR-KP isolates to amikacin was 72.2％ ( 13/18 ) , compound sulfamethoxazole was 61.1％(11/18), tigecycline was 0％(0/18).Conjugation study with Escherictda coli J53 resulted in the transfer of significant reduced carbapenem susceptibility from donors (MICs increased at least 8-fold).By PCR, eighteen strains of Klebsiella pneumoniae carried NDM-1 gene, 5 strains carried KPC-2 gene.The blaNDM-1 was transferable by plasmids.Southern blot hybridization indicated that the blaNDM-1 gene was located on plasmid in size of 46 kb.The plasmid belonged to incompatibility group IncX 3.Seven types of CR-KP were detected by PFGE.In addition, MLST assigned them to sequence type ( ST)11, ST395, ST17, ST37, ST263, ST14 and ST76 types.SDS-PAGE and ompK35/36 genes sequence analysis of Omp indicated that there was absence of outer membrane proteins OmpK 36 in ST11, ST395, ST37 strains.However, the other STs strains expressed lower quantities of OmpK 36.Conclusions High level carbapenem resistance in K.pneumoniae causing infection in burn patients is attributable to production of plasmid-mediated metallo· β-laetamase NDM-1 combined with porin OmpK36 deficiency or low expression .The K.pneumoniae with NDM-1 and KPC-2 carbapenemase were detected .

The National Health Commission recently has released a notice about further promoting the trauma rescue and treatment in China, which includes four main contents as follows: ( 1 ) to strengthen the establishment of regional trauma rescue and treatment system based on trauma center;(2) to lift the specialized medical service ability related to trauma rescue and treatment; ( 3 ) to further develop the radiant and stimulating role of National Trauma Medical Centre and National Regional Trauma Medical Center;(4) to enhance the trauma-related professional training and public health education. In this article, we interpret the third aspect regarding medical quality control and maintenance of trauma treatment, providing reference for better understanding the specific requirements of the document.

Objective To investigate the feasibility of computer-aided pancreas segmentation based on three-dimensional (3D) Dixon MRI at 3.0-T.Methods Five volunteers with health pancreas underwent upper abdominal 3D Dixon MRI at 3.0T with the same scan parameters while holding breath.The automatic segmentation of pancreas is based on the Medical Imaging Interaction ToolKit (MITK) with homemade software.A experienced radiologist performed manual segmentation and computer aided segmentation of the pancreas on the opposed phase and water phase images twice.Similarity was analyzed and compared for the manual and automated segmentations for the two group images.Similarity was presented as Dice coefficients.Results Both of the oppose phase and water phase images of Dixon MRI showed that the signal intensity of pancreas was higher than that of the surrounding tissue,the similarity of water phase was obviously higher than that of oppose phase and the differences were statistically significant.Based on Dixon MRI water phase and oppose phase images,the mean dice coefficients for the manual segmentations were 0.81 ± 0.01 and 0.85 ±0.03,respectively,for both the oppose phase and water phase images (P=0.013).For the automated segmentations,the dice coefficients were 0.69 ± 0.08 and 0.75 ± 0.03 for water phase images and the oppose images,respectively,and the difference was not statistically significant (P =0.155).Conclusions 3.0T oppose phase and water phase of Dixon images could clearly show the pancreas,and automated pancreas segmentation based on water phase Dixon MRI obtained higher similarity,which was feasible.