Effect of Modified Shenling Baizhusan on Gastrointestinal Dysfunction and Protein-energy Wasting in Continuous Ambulatory Peritoneal Dialysis Patients / 中国实验方剂学杂志

ObjectiveTo observe and analyze the effect of modified Shenling Baizhusan on gastrointestinal dysfunction and protein-energy wasting （PEW） of continuous ambulatory peritoneal dialysis （CAPD） patients with the syndrome of spleen deficiency， blood stasis， and dampness. MethodA total of 66 CAPD patients with the above syndrome were randomized into the observation group and control group， 33 cases in each group. However， 3 cases in each group dropped out， finally leaving 30 cases in each group. Both groups received CAPD and conventional symptomatic treatment. On this basis， the observation group was given modified Shenling Baizhusan （1 bag/day， once in the morning and again in the evening， 12 weeks）， and the control group the bifidobacterium capsules （1.05 g/time， twice/day， 12 weeks）. Before and after treatment， the traditional Chinese medicine （TCM） syndrome score， gastrointestinal symptom rating scale （GSRS） score， and malnutrition-inflammation score （MIS） in two groups were recorded， and the levels of serum albumin （ALB）， prealbumin （PA）， transferrin （TRF）， gastrin-17 （G-17）， tumor necrosis factor alpha （TNF-α）， interferon-γ （IFN-γ）， and interleukin-10 （IL-10） were detected. Moreover， body mass index （BMI） was calculated. ResultAfter treatment， the alleviation of the TCM syndrome in the observation group was better than that in the control group （Z=-2.591， P<0.05）， and the TCM syndrome score in the observation group was lower than that in the control （P<0.05）. The symptom scores， MIS， and G-17 of the observation group were significantly decreased compared with those before observation and in the control group （P<0.05）. After treatment， the GSRS scores of the two groups were significantly lower than those before treatment （P<0.05）， particularly the observation group （P<0.05）. ALB， PA， TRF， and BMI of the observation group after treatment were increased compared with those before treatment and those of the control group after treatment （P<0.05）. After treatment， serum TNF-α and IFN-γ of the two groups were significantly reduced compared with those before treatment （P<0.05）， and the levels of the two in the observation group were significantly lower in the observation group than in the control group （P<0.05）. After treatment， IL-10 level of the observation group was higher than that before treatment and in the control group （P<0.05）. ConclusionThe modified Shenling Baizhusan can relieve the gastrointestinal dysfunction and PEW in CAPD patients with the syndrome of spleen deficiency， blood stasis， and dampness.

Qingshen granule-medicated serum attenuates high glucose-induced epithelial-mesenchymal transition of HK-2 cells via inhibiting oxidative stress-mediated NF-κB signaling pathway / 中国病理生理杂志

AIM:To investigate whether Qingshen granules(QSG)-medicated serum inhibits oxidative stress-mediated NF-κB signaling pathway and attenuates epithelial-mesenchymal transition(EMT)of human proximal tubule epi?thelial HK-2 cells induced by high glucose. METHODS:The active components in QSG were analyzed by HPLC. The HK-2 cells were randomly divided into control group,mannitol group,high glucose group,low-dose QSG group,medium-dose QSG group,high-dose QSG group and pyrrolidine dithiocarbamate(PDTC)group. The morphological changes of the cells were observed by inverted phase contrast microscopy. MTT assay was used to detect the cell viability. Flow cytometry was used to detect the content of reactive oxygen species(ROS)in HK-2 cells. ELISA was used to detect the content of malondi?al dehyde(MDA)and the activity of superoxide dismutase(SOD). The DNA binding activity of nuclear factor-κB(NF-κB) p65 in HK-2 cells was detected by electrophoretic mobility-shift assay(EMSA). The protein expression of NF-κB p65, phosphorylated inhibitor of kappa B alpha(p-IκBα),inhibitor of kappa B kinase alpha(IKKα),monocyte chemoattractant protein-1(MCP-1)and intercellular adhesion molecule-1(ICAM-1)in HK-2 cells was detected by Western blot. Immuno?fluorescence staining was used to detect NF-κB p65 andα-smooth mucle actin(α-SMA)protein expression in HK-2 cells. RESULTS:Chlorogenic acid,berberine hydrochloride,plantamajoside,6,7-dimethoxycoumarin,epiberberine,copti?sine,lithospermicacid B,palmatine,leonurine hydrochloride,rheic acid and tanshinone ⅡA in QSG were preliminarily de?termined by HPLC. Compared with control group,the levels of ROS and MDA in HK-2 cells induced by high glucose in?creased(P<0. 05),while the activity of SOD decreased(P<0. 05). The protein levels of NF-κB p65,p-IκBα,IKKα, MCP-1,ICAM-1 andα-SMA were increased(P<0. 05). After intervened by QSG-medicated serum,the levels of ROS and MDA were decreased(P<0. 05),while the activity of SOD was increased(P<0. 05). The protein levels of NF-κB p65,p-IκBα,IKKα,MCP-1,ICAM-1 andα-SMA were decreased(P<0. 05). CONCLUSION:QSG-medicated serum inhibited oxidative stress-mediated NF-κB signaling pathway,thus attenuating the EMT of HK-2 cells induced by high glucose.

Measurement of the weight and volume of submandibular gland in vitro / 北京大学学报(医学版)

OBJECTIVE@#To measure the weight and volume of normal submandibular gland by in vitro detection of glandular body, to compare with the measurement values of CT volume rendering to evaluate the consistency of the two methods, and to explore the related factors affecting the weight and volume of the submandibular gland.@*METHODS@#The patients who underwent neck dissection due to oral cancer and were confirmed with normal submandibular gland by postoperative histopathology in Peking University School and Hospital of Stomatology from May 2019 to January 2020 were collected in this study and divi-ded into 4 groups according to the age standards raised by the Society of Geriatrics Chinese Medical Association and WHO (2000) age standards. The submandibular gland was carefully dissected along with the capsule immediately after neck dissection. The weight and volume of submandibular gland were accurately measured by an integrated aseptic measuring device. The volume of submandibular gland was measured by CT volume rendering before operation and the consistency of the two methods was evaluated. The 95% confidence interval of the weight and volume of submandibular gland in the different groups of Chinese people, which were divided by gender and age, were calculated, and the correlation with age, gender, height, weight, body mass index (BMI) and other factors was analyzed.@*RESULTS@#The weight and vo-lume of submandibular gland were measured in 220 subjects. The average weight and volume of submandibular gland were (11.69±2.45) g and (11.55±2.41) cm3 respectively. The volume of submandibular gland measured by CT volume rendering ranged from 70% to 82% of that measured by in vitro detection of glandular body, and the correlation coefficient between the two methods was 0.976 (P < 0.05). The gender difference of weight and volume of submandibular gland existed in the groups of youth, middle-aged, young elderly and elderly groups, the values of males were obviously higher than those of females (P < 0.05). There was no gender difference of weight and volume of submandibular gland in the adolescent group (P > 0.05). The weight and volume of submandibular gland had a strong positive correlation with body height (P < 0.05), a weak positive correlation with body weight (P < 0.05), and no correlation with BMI (P > 0.05). The female's weight and volume of submandibular gland in the young elderly and elderly groups were significantly lower than those in the other three groups (P < 0.05).@*CONCLUSION@#The normal reference range of the weight and volume of submandibular gland in vitro were established in different age and gender groups of Chinese people. The volume of submandibular gland mea-sured by CT volume rendering was 70%-82% of that measured by in vitro detection of glandular body. The results of the two methods had a high degree of consistency. The weight and volume of submandibular gland were related to age, gender, body height and body weight.

Application of bedside ultrasound monitoring of gastric residual volume in postoperative patients with rheumatic heart disease complicated with cachexia with enteral nutrition support / 肠外与肠内营养

Objective:To investigate the effect of bedside ultrasound in measuring the gastric residual volume in postoperative patients with rheumatic heart disease complicated with cachexia with enteral nutrition support.Method:From June 2015 to May 2017,60 patients with rheumatic heart disease complicated with cachexia who admitted in ICU were randomly divided into two groups,group A (routine enteral nutrition plan plus ultrasound monitoring GRV)and group B (routine enteral nutrition plan plus withdraw every 4h to monitor the GRV),to guide the implementation of enteral nutrition.Results:There was significant difference in Hb,TP and ALB levels between the two groups (P ＜0.05).The nutritional status of group A was better than that of group B.The incidence of gastric retention and pulmonary infection in group A was significant lower than group B (P ＜0.05).The length of target feeding time and ICU stay had a statistically difference in group A and group B [(3.02 ± 0.78) d vs (4.89 ± 0.69) d,t=2.278,P=0.019] and [(10.41 ± 1.98) d vs (11.39 ± 1.75) d,t=2.384,P=0.015].Conclusion:The application of bedside ultrasound to monitor the gastric residual volume can be an accurate method to guide enteral nutrition in postoperative patients with rheumatic heart disease complicated with cachexia,which can improve the nutrition status,shorten the length of target feeding time and ICU stay and reduce enteral nutrition-related complications.

Effect of Rong Huang granules of patients with non-dialysis kidney deficiency damp heat syndrome and chronic kidney disease mineral and bone metabolism disorder to serum OPG and RANKL levels / 中国免疫学杂志

Objective:To observe serum osteoprotegerin (OPG),receptor activator of NF-kB ligand (RANKL) levels and the therapeutic effect of Rong Huang granules of patients with non-dialysis chronic kidney disease mineral and bone metabolism disorder (CKD-MBD) and kidney deficiency damp heat syndrome.Methods:70 cases of non-dialysis CKD-MBD with kidney deficiency damp heat syndrome,were randomly divided into treatment group and control group,the actual completion of 61 cases,30 cases in treatment group,31 cases in the control group;and a healthy normal group of 20 cases of patients was established.Two groups of patients were given symptomatic treatment,in addition,Rong Huang granules was plused in treating at treatment group and it was used three times a day,each time blunt one bag.The course of treatment was 8 weeks.The changes of kidney deficiency damp heat syndrome,blood urea nitrogen (BUN),serum creatinine (Scr),estimated glomerular filtration rate (eGFR),serum of calcium (Ca),phosphorus (P), alkaline phosphatase (ALP),parathyroid hormone (iPTH),OPG and RANKL levels were observed in two groups of patients.Results:The total effective rate in treatment group was significantly better than the control group(P<0.01).The integral value of syndrome decreased more significantly with the course of treatment increased of two groups of patients(P<0.01).Compared with the same period of therapy,the descender in the treatment group was significantly better than that in the control group(P<0.01).The levels of BUN, Scr,eGFR,Ca,P,iPTH and ALP were improved in the treatment group after treatment(P<0.05 or P<0.01),BUN and iPTH were improved in the control group(P<0.05 or P<0.01),other indexes were not improved(P>0.05).After treatment,BUN,Scr,eGFR,Ca, P,iPTH,ALP of treatment group were significantly better than the control group(P<0.05 or P<0.01).Compared with the normal group,the levels of OPG and RANKL were significantly higher in CKD-MBD patients (P<0.01).After treatment,serum OPG level, serum RANKL level and OPG/RANKL ratio were significantly improved than before treatment in treatment group(P<0.05 or P<0.01),and in the control group,only the OPG/RANKL ratio increased(P<0.01).After treatment,OPG,RANKL and OPG/RANKL ratio in the treatment group were obviously improved compared with them in the control group(P<0.05 or P<0.01).Conclusion:The levels of OPG and RANKL in non-dialysis CKD-MBD patients with kidney deficiency damp heat syndrome were higher than those in healthy people,and the ratio of OPG/RANKL was lower than that in healthy people.Rong Huang granules can ameliorate clinical symptoms,prevent calcium and phosphorus metabolism,improve renal function,the mechanism may be related to the ameliorate of serum OPG and the decrease of serum RANKL level and the raise of ratio of OPG/RANKL.

Intervention effect of Qingshen Granules on oxidative stress in patients with chronic renal failure of damp-heat syndrome / 中成药

AIM To observe the changes of serum ROS,MDA,SOD levels in chronic renal failure (CRF) patients with damp-heat syndrome and to explore the intervention effect of Qingshen Granules (Hedyotis diffusae Herba,Salviae miltiorrhizae Radix et Rhizoma,Artemisiae scopariae Herba,etc.) on oxidative stress.METHODS Seventy cases of CRF patients with damp-heat syndrome were randomly and equally divided into control group and treatment group.Sixty cases completed the study,thirty-one cases in the treatment group,twenty-nine cases in the control group.Twenty other cases served as the normal group.The treatment group and the control group were given the basic treatment of western medicine and retention enema of TCM.The treatment group was added Qingshen Granules for eight weeks.The levels of U-Pro/24 h,Scr,BUN,estimated glomerular filtration rate (eGFR),serum ROS,MDA and SOD were measured before and after the treatment,and were compared with the normal group.RESULTS Both total effective rates on disease and on traditional Chinese medicine syndrome in the treatment group were 83.87％,significantly higher than those in the control group (51.72％ and 48.28％),respectively.The levels of U-Pro/24 h,Scr and BUN were obviously lower in the treatment group after the treatment,and eGFR was obviously higher as compared with those in the control group.Before the treatment,the levels of ROS and MDA in the treatment and control groups were significantly higher than those in the normal group,and the level of SOD was significantly lower;the levels of ROS and MDA were reduced in the treatment group after the treatment,and the level of SOD was increased;these changes in the treatment group were more significant than those in the control group.CONCLUSION Qingshen Granules can ameliorate clinical symptoms in CRF patients with damp-heat syndrome,decrease the levels of U-Pro/24 h,Scr and BUN,increase eGFR level,inhibit oxidative stress,and enhance antioxidant capacity,ultimately delay the development of renal fibrosis.

Lipid metabolomics in serum of hyperuricemic rats induced by fructose based on UPC²-Q/TOF-MS / 中国中药杂志

To explore the differences in lipid metabolites in serum of hyperuricemic rats induced by fructose and normal rats by using lipid metabolomics technology, and screen the potential biomarkers related to hyperuricemia. The metabolic fingerprint spectrum of the serum in hyperuricemic rats(model group) and normal rats(control group) was obtained and analyzed by using ultra performance convergence chromatography-tandem-Q-time of flight mass spectrometry(UPC ² -Q/TOF-MS) method and the differences of metabolic spectra between two groups were compared via the multivariate statistical methods to screen differential metabolites. The results indicated that there was significant difference in metabolic spectra between model group and control group, and 11 differential metabolites were screened. Then eight potential biomarkers such as arachidonic acid, palmitic acid, oleic acid and linoleic acid were tentatively identified by using the exact mass number and secondary mass spectrometry(MS/MS spectrum). Therefore, a new research method for lipid metabolomics in serum of hyperuricemic rats induced by fructose was established successfully based on UPC ² -Q/TOF-MS. What's more, it was speculated that the abnormal metabolism of fatty acid might be associated with the pathogenesis of hyperuricemia, which would provide scientific basis for early detection and prevention of hyperuricemia.

Automated three-dimensional measurement on anatomic parameters of proximal femur / 医用生物力学

ObjectiveTo automatically measure anatomic parameters of proximal femur by establishing three-dimensional (3D) coordinate system of the femur based on bony landmarks, so as to assist pre-operative planning and design of customized femoral stem. MethodsThe software named "Femeter" was independently developed for anatomic measurement of the femur, which allowed importing the femur models with STL format and manually locating the targeted anatomic landmarks. The 3D modeling of femoral medullary canal was rapidly created by semi-spherical iterative searching algorithm, and 16 key anatomic parameters of proximal femur, including femoral head radius, neck-shaft angle, anterversion were automatically calculated by least-squares fitting algorithm. ResultsBy experimenting on 30 femur STL models, the average execution time of single measurement was (0.95±0.16) seconds, and the intra-class correlation coefficient of 9 anatomic parameters was between 0.907 and 0.999, which showed high intra-rater and inter-rater reliability. ConclusionsThe automatic modeling and execution time of measuring algorithm by Femeter are fast, with satisfactory measurement repeatability and easy interaction, which is easily applicable to clinical practice. The 3D anatomic measurement of proximal femur can provide solid data for pre-operative planning of total hip arthroplasty, selection of commercialized femoral stem and design of customized femoral stem.

Gelsolin level for prognostic evaluation in patients with critically illness / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the changes of plasma gelsolin level in patients with critical illness and its application in prognostic evaluation.</p><p><b>METHODS</b>Ninety six critically ill patients admitted in ICU of Sichuan Provincial People's Hospital from February 2012 to December 2013 were enrolled in the prospective cohort study. Plasma gelsolin levels were detected with enzyme linked immunosorbent assay (ELISA) at admission (d1), d2, d4 and d8 after admission, and also detected in blood samples of 186 healthy subjects as controls. Logistic regression model was used to analyze the relationship between the level of plasma gelsolin and prognosis of patients.</p><p><b>RESULTS</b>The average levels of plasma gelsolin were significantly lower in critically ill patients than those in control subjects (F=1986.37, P<0.01). There was significant difference in overall level of gelsolin between survival patients and fatal patients (F=16.691, P<0.01). APACHE Ⅱ score was associated with survival outcomes (r=0.489, P=0.009); the APACHE Ⅱ score was significantly higher in fatal patients than that in survival patients (29.5±7.7 vs 22.1±5.7, t=5.375, P<0.01). There was a negative correlation between plasma gelsolin levels and fatal outcomes (r=-0.512, P<0.01). Logistic regression analysis showed that the overall plasma gelsolin levels and the last measured level was a prognostic factor for critically ill patients (P<0.05).</p><p><b>CONCLUSION</b>Plasma gelsolin levels are correlated with the severity of critically ill patients, and plasma gelsolin can be used as indicator of prognosis.</p>

Finite element analysis on stress change of the lumbar disc degeneration / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the mechanical changes of the degenerated lumbar disc with finite element analysis.</p><p><b>METHODS</b>A three dimensional finite element model of a human lumbar spine at the L3-L4 disc was established by the software MIMICS and ABAQUS based on computer tomography images. Degeneration was modeled by changes in geometry and material properties. The model was loaded with 0.3 MPa in axial plane. The von Mises stress on the annulus fiber, nucleus pulposus, endplate and facet joints in healthy and degenerated discs was compared.</p><p><b>RESULT</b>Compared with healthy discs, the von Mises stress of disc distributed in the side of annulus fiber, the stress of nucleus pulposus decreased remarkably, the stress of endplate distributed in the posterior part, and the stress of facet joints increased for the degenerated disc.</p><p><b>CONCLUSION</b>The finite element models can provide a method of understanding the relationship between biomechanical performance of the disc due to disc degeneration.</p>

Effect of qingshen granule on plasma P-selectin and intercellular adhesion molecule-1 in patients with sharp deteriorated chronic renal failure of damp-heat syndrome type / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the plasma levels of p-selectin (CD62 P) and intercellular adhesion molecule-1 (ICAM-1) in patients with sharp deteriorated chronic renal failure (CRF) of damp-heat syndrome type (DHS), and the curative efficacy of Qingshen Granule (QSG) on the disease.</p><p><b>METHODS</b>Sixty cases with sharp deteriorated CRF of DHS were equally randomized to the treated group and the control group, all were treated with conventional Western medical therapy combining with retention enema of Jiedu Xiezhuo No. II; but for patients in the treated group, QSG was given additionally, 1 bag thrice a day by oral intake. The therapeutic course for all was 1 month. Besides, a group of 20 healthy persons was set up for normal control. Plasma levels of CD62 P and ICAM-1 were measured before and after treatment, and were compared with those in the normal control.</p><p><b>RESULTS</b>Both the total effective rate on disease and on Chinese medicine syndrome in the treated group were 90.0% (27/30), significantly higher than those in the control group, 60.0% (18/30) and 63.3% (19/30), respectively, showing significant differences between groups (P < 0.05). Plasma levels of CD62 P and ICAM-1 were obviously higher before treatment as compared to those in the normal control group (P < 0.01), which reduced markedly after treatment in both treated group and control group (P < 0.05), but the changes in the treated group were more significant (P < 0.05).</p><p><b>CONCLUSIONS</b>Patients with sharp deteriorated CRF of DHS show higher plasma levels of CD62 P and ICAM-1 in comparing with the normal control. Treatment of retention enema with QSG in combined with JDXZ No. II could reduce the two indexes more significantly than that using retention enema alone, and the combined therapy could also improve renal function and ameliorate clinical symptoms in patients.</p>

Histologic and ultrastructural studies of the patient died of highly pathogenic H5N1 avian influenza virus infection in China / 中华病理学杂志

<p><b>OBJECTIVE</b>To explore histopathologic and ultrastructural characteristics of human avian influenza (AI) infection and related etiological pathogenesis.</p><p><b>METHODS</b>Postmortem lung and heart samples were collected from the patient who died of avian influenza virus infection on November 29, 2003 in China. Light and electron microscopy, immunohistochemistry and histochemistry were used to investigate the pathological changes.</p><p><b>RESULTS</b>The main pathological findings included extensive pulmonary consolidation, hemorrhage, pulmonary edema and local hemorrhagic infarct. The lamina of alveoli and bronchioles were abundantly filled with protein-rich fluid, erythrocytes, fibrin and cell debris admixed with many neutrophilis, macrophages, lymphocytes and a few of monokaryon and multinuclear giant cells. Hyaline membranes were formed. Local pulmonary tissues were heavily damaged by hemorrhage and necrosis. Alveolar septum was disintegrated. Mesenchymal edema with a few of macrophages infiltration of heart was found. Electron microscopy showed the avian influenza A virus-like particles (type C and type A) of 80 - 120 nm diameter and envelopes in the cytoplasm of pneumocytes and endothelial cells.</p><p><b>CONCLUSIONS</b>Fatal pneumonia associated with highly pathogenic avian influenza A virus (H5N1) infection leads to extensive pulmonary consolidation, edema and marked hemorrhagic necrosis and inflammation. Electron microscopy can identify avian influenza A virus-like particles. The findings may offer an important theoretical basis for clinical diagnosis and treatment.</p>

Adenovirus-mediated stromal cell-derived factor-1 alpha gene transfer promotes mesenchymal stem cell migration / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the role of stromal-derived factor-1 (SDF-1) in the migration of mesenchymal stem cells (MSCs) and the underlying signal transduction mechanism.</p><p><b>METHODS</b>Rat bone marrow-derived MSCs were infected with 100 ml recombinant adenovirus containing human SDF-1alpha gene (Ad-hSDF-1alpha), and the cell migration changes were observed at 1, 2, and 3 days after the infection. Twelve hours after Ad-hSDF-1alpha transfection, the MSCs in separate cultures were treated with wortmannin (50 nmol/L), LY294002 (10 mmol/L), PD98059 (50 mmol/L), U73122 (10 mmol/L), AMD3100 (0.1 g/L), or verapamil (50 nmol/L), respectively, and the signal transduction pathways involved in MSC migration were analyzed.</p><p><b>RESULTS</b>The MSCs grew in colonies after transfection with Ad-hSDF-1alpha, but this growth pattern was substantially attenuated after treatment with wortmannin, LY294002, PD98059, U73122, AMD3100 and verapamil, among which U73122 and AMD3100 treatments resulted in the most conspicuous inhibitory effects.</p><p><b>CONCLUSION</b>The effect of SDF-1 in promoting MSC migration is related to mitogen-activated protein kinase, phosphatidylinositol phospholipase C, and protein kinase signal pathways.</p>

Urinary tract infections among old patients with diabetes mellitus clinical analysis / 中国实用内科杂志

Objective To investigate the clinical manifestation of bacterial urinary tract infections among old patients with diabetes in recent seven years.Methods In this retrospective study,contrast analysis of clinical features was per- formed on urinary tract infections in old patients between 56 cases with diabetes and 56 cases without it diagnosed during 1998 to 2005.measuring fasting blood glucose,2 hour blood glucose,plasma albumin,24-hour microalbuminuria. Results Incidences of diabetic nephropathy,diabetic retinopathy,neuropathic bladder in observed group are signifi- cantly higher than control group.FBG、2hPBG、24-hour microalbuminuria are significantly higher than control group and plasma albumin is lower than control group.Conclusion The urinary tract infection in old patients with diabetes is associated with fasting blood glucose concentration,complication,gender,disease period and ages,etc.

Studies on production, purification and partial characteristics of the extracellular laccase from Armilliria mellea / 生物工程学报

The production conditions of extracellular laccase from Armilliria mellea and the characteristics of the enzyme were studied. The experiment proved that initial pH5.5 of the culture medium and temperature at 25 degrees C were favorable for laccase synthesis. As carbon resources, cellobiose and raffinose were better in terms of productivity than maltose, sorbose and galactose. Organic nitrogen source was more suitable for Armilliria mellea to synthesize laccase than inorganic nitrogen source. Peat extract (PE) enhanced notably the yield of laccase; the maximal yield was 7 times as much as that of the control when PE concentration was 50%. Three isozymes were detected in culture supernatant named A, B and C respectively after their mobility on PAGE. After concentrated by (NH4)2SO4 precipitation, laccase A was further purified to homogeneity by preparative native PAGE and anion exchange column chromatography. The native enzyme was a single polypeptide with a molecular mass of approximately 59 kD estimated by SDS-PAGE, while 58 kD by gel filtration chromatography under non-denaturing conditions. Determined by IEF its isoelectric point was 4.0. The optimal pH value and temperature were 5.6 and 60 degrees C respectively in catalytic reaction of oxidizing guaiacol. At 60 degrees C and 65 degrees C, half-lives of laccase A were 45 min and 36.8 min, respectively. Enzyme activity was inhibited with 100 mmol/L Cl-, but was activated with 1 mmol/L SO4(2-). However, if the concentration of NaN3 was only 1 mmol/L, laccase A lost its activity completely. 10 mmol/L EDTA had no effect on laccase A, while 1 mmol/L Cu2+ could enhance its activity. Laccase A showed a good stability when the pH of the buffer varied from 5.2 to 7.2. Using guaiacol as the substrate, the Km was 1.026 mmol/L and the Vmax was 5 mumol/(min.mg); using ABTS instead, the Km was 0.22 mmol/L and Vmax was 69 mumol/(min.mg).

Immobilization of Fungal Laccase on Nylon Net and Application of the Immobilized Enzyme / 微生物学通报

Condition optimization for immobilization of Fungal laccase with Nylon Net and glutaraldehyde and the nature of the immobilized enzyme were studied. The optimum conditions of the immobilization are: Nylon Net is crosslinked with 5% glutaraldehyde 15mL for 6 hours; the 30U laccase is added for immobilization for 8 hours. On this case, the recovery of enzyme activity was 50.3%. Compared with free enzyme, the thermal stability of immobilized enzyme was improved evidently but the optimal pH decreased slightly. 52% enzyme activity of immobilized laccase was hold after 8 cycles treatment with low concentration pulp wastewater.

PRELIMINARY STUDIES ON LACCASE PRODUCTION BY A WHITE-ROT FUNGUS AH28-2 / 微生物学通报

A novel white-rot fungus AH28-2,which was isolated from 224 fungi samples,ability to produce effectively laccase by induction.Several factors influencing laccase production were investigated.The optimum conditions were as follows:the 300mL Erlenmeyer flask containing 150mL of liquid medium was inoculated with 7.5mL of mycelial fragments and the medium was supplied with lignin at a concentration of 0.1%(initial pH8.5).The cultures was incubated at 28℃ on rotary shaker(150r/min) for 4～5 days.The maximum enzyme activity was 20184IU/L.