The template-independent teminal transferase activity of Taq DNA polymerase results in an overhanging dA at the 3′end of its PCR products. The pGEMX vector constructed in this experiment forms a single overhanging dT at its 3′end as the result of cleavage with Xcm I restriction enzyme. This vector is very efficient for direct cloning of PCR product obtained by using Taq DNA polymerase.Recombinant colonies can be selected by Blue/white screening. Moreover,insertion fragment can be easily released from the vector simply with either BamH I or Hind III digestion.

To prepare sagittatoside B with epimedin B Hydrolyzed from cellulase. With the conversion ratio as the index, the effects of pH value, temperature, reaction time, dosage of enzyme and concentration of substrates on the conversion ratio were detected. L9 (3(4)) orthogonal design was adopted to optimize the preparation process. Hydrolyzed products were identified by MS, 1H-NMR, and 13C-NMR. The results showed that the optimum reaction conditions for the enzymatic hydrolysis were that the temperature was 50 degrees C, the reaction medium was pH 5.6 acetic acid-sodium acetate buffer solution, the concentration of substrates was 20 g x L(-1), the mass ratio between enzyme and substrate was 3: 5, and the relative molecular mass of the reaction product was 646.23. NMR data proved that the product was sagittatoside B. The process is simple and reliable under mild reaction conditions, thus suitable for industrial production.
Cellulase ; metabolism ; Drug Compounding ; methods ; Flavonoids ; chemistry ; Hydrogen-Ion Concentration ; Hydrolysis ; Temperature ; Time Factors

Some problems are arisen in teaching diagnostic pathology in our college for postgradu-ates of Pathology and Pathophysiology, the students' basic knowledge is weak, the cycle is short, the teaching team and resources are relatively insufficient. To promote the cultivation of graduate students, we should carry out the CBL teaching method, add the clinical practice and training, strengthen the teaching staff, and apply digital section and network platform.

Objective:To investigate the heterogeneity of epitopes recognized by anti-GBM autoantibodies in sera from a large cohort of Chinese patients with anti-GBM disease and its clinical significance.Methods: The present study included 108 patients with anti-GBM disease who were diagnosed in our hospital, between Jan 1991 and May 2009, with complete clinical and renal pathological data. Sera or plasma exchange of the patients were used to incubate with cryostat section of normal human renal tissue for indirect immunofluorescence (IIF) assay. The cryostat sections of normal renal tissue were pre-treated by 6 mol/L urea to unmask cryptic epitopes, and untreated cryostat sections were used to detect natural exposed epitopes. The sera were diluted from 1:2 to 1:512 to determine titers of anti-GBM autoantibodies Patients with anti-GBM autoantibodies against cryptic or exposed epitopes were further stratified;their clinical and pathological associations were analyzed. Results: Sera from all the 108 patients could recognize cryptic epitopes on normal renal tissue ( urea treated section). IIF showed IgG linear staining along GBM. However, sera from 56/108 patients (group A) could also recognize exposed epitopes on normal renal tissue (untreated section) ; sera from the rest 52/108 patients (group B) could not recognize exposed epitopes. In urea treated condition, the average titer of anti-GBM autoantibodies from sera of patients in group A was significantly higher than that in group B (P＜0.01) , ANCA-positive patients in group A were significant less than that in group B (P＜0.01) . There was no significant difference between the two groups in regard to other clinical data (including serum creatinine) and renal histopathologic data. Conclusion: Anti-GBM autoantibodies from some patients with anti-GBM disease could recognize natural exposed epitopes, however, their anti-GBM titer for cryptic epitopes was higher than that of those recognizing cryptic epitopes only and the prevalence of serum ANCA was significantly less.

Protein disulfide isomerase-related protein A (PRPA) was highly expressed (about 34%) in Escherichia coli by inserting the whole PRPA cDNA into the vector pET23b. After expression, the purified protein was acquired through ammonium fractional precipitation and Bio-Rex 70 chromatography. PRPA shows low disulfide isomerase activity (only about 1/250 of that of hPDI), decreases the reactivation yield of denatured and reduced lysozyme either in redox and non-redox Hepes buffer or redox PBS buffer and facilitates the aggregation of denatured and reduced lysozyme. Fluorescence spectra of PRPA indicate that PRPA has more hydrophobic groups at surface than that of hPDI, and which can be used to explain why PRPA has anti-chaperone activity during the refolding of denatured and reduced lysozyme.
Cloning, Molecular ; Fungal Proteins ; chemistry ; genetics ; isolation & purification ; Muramidase ; chemistry ; Plasmids ; Protein Folding ; Recombinant Proteins ; biosynthesis ; isolation & purification ; Spectrometry, Fluorescence

The real sanghuang is a new species belonging to the Inonotus, which is commonly used for cancer treatment and human immune system improvement. This review summarized the progress on the studies of Phellinus Quel in recent years, including its taxonomy status, bioactive components, pharmacodynamics, separation and purification technologies. In addition, some related problems and perspectives were also discussed.
Animals ; Basidiomycota ; chemistry ; classification ; Humans ; Medicine, Chinese Traditional ; methods

Objective:To study the clinical characteristics of hepatic injury following umbilical vein catheterization, so as to improve the safety and use of umbilical vein catheterization in the newborn.Methods:Data of infants undergoing umbilical vein catheterization during hospitalization in the neonatology department of the Third Affiliated Hospital of Guangzhou Medical University from Jan 1st, 2015 to Dec 31st, 2019 were collected retrospectively.The clinical characteristics, diagnoses and treatments of the infants with hepatic injury following umbilical vein catheterization were summarized and analyzed.And the relative literature was reviewed.Results:A total of 1 721 infants underwent umbilical vein catheterization, and seven cases(0.4%)had hepatic injury, including six cases of exudative necrosis in the liver and one case of hepatic hematoma.There was no significant difference in gestational age[(31.12±2.64)weeks vs.(30.62±2.75)weeks]or birth weight[(1 493±525)g vs.(1 374±473)g]between hepatic injury group and non-hepatic injury group( P>0.05). Clinically, it was found that the tip position of umbilical vein catheter was below the diaphragm(between the 9th and 11th thoracic vertebrae)in all seven cases.Except one case with no obvious clinical symptoms, the other six cases had clinical symptoms, mainly manifested as abdominal distension, repeated gastric retention, decreased bowel sounds, and additional with shock and anemia in hepatic hematoma.Blood sample tests showed elevated C-reactive protein, white blood cell count and transaminase.X-ray examination revealed cystic translucent shadow in the liver, and ultrasound and/or computed tomography examination showed the lesion in more detail.After removal of the catheter and administration of antibiotic, the hepatic injury recovered gradually. Conclusion:The hepatic injury following umbilical vein catheterization in neonates is not common.The catheter tip under the diaphragm is the main risk factor.And the diagnosis is dependent on imaging examination.

OBJECTIVERespiratory syncystial virus (RSV) is the most common cause of lower respiratory infections in infants worldwide. There is no reliable vaccine or antiviral drug against RSV at present. RNA interference (RNAi) technology is a potent method to degrade expression of the cognate mRNA. In order to inhibit the replication of RSV at gene level, the effects of specific RNAi against M2-1 gene of RSV on inhibition of viral replication in cell culture system was observed in this study.

METHODSRSV M2-1 gene, which plays a key role in RSV transcription, was chosen in this study and was used as target gene and recombinant plasmid pshRNA7816 targeting the mRNA of RSV M2-1 gene coding sequence was constructed. The pshRNA7816 was transfected into Hep2 cells. The effects of the pshRNA7816 on changes of cytopathogenic effect (CPE) of Hep2 cell induced by RSV infection were observed microscopically. Viral plaque forming assay and MTT assay were used to detect the viral titer change and protective function of the pshRNA7816 on RSV infected Hep2 cell.

RESULTSThe recombinant RNAi plasmid pshRNA7816 which targets the mRNA of RSV M2-1 gene was successfully constructed. The pshRNA7816 significantly reduced CPE of RSV infected Hep2 cells, reduced the viral titer of RSV in the cells (P < 0.001). The pshRNA7816 raised the survival rate of RSV infected Hep2 cells (P < 0.001). Non-specific pshRNA plasmid did not show anti-RSV effects (P > 0.05).

CONCLUSIONThe recombinant pshRNA7816 plasmid which targeted the mRNA of RSV M2-1 gene showed a significant and specific anti-RSV effect.

Hep G2 Cells ; Humans ; Plasmids ; biosynthesis ; RNA Interference ; RNA, Small Interfering ; biosynthesis ; RNA, Viral ; genetics ; Respiratory Syncytial Virus Vaccines ; biosynthesis ; Respiratory Syncytial Virus, Human ; drug effects ; physiology ; Viral Proteins ; genetics ; Virus Replication ; drug effects

OBJECTIVETo investigate the effect of ischemic postconditioning on the expression of rat myocardium matris metalloproteinase-2 (MMP-2) induced by ischemia/reperfusion (I/R) and relationship between its expression and interstitium and the effect on left ventricular function.

METHODSTwenty-four rats were randomly divided into 3 groups (n = 8): sham control (SC) group, ischemic/reperfusion (I/R) group and ischemic postconditioning (IPTC) group. The left ventricular peak systolic pressure and its derivate (+/- dp/dt) were calculated; The amount of myocardium collagenous were determined; The vitality of superoxide dismutase (SOD) and content of malondialdehyde (MDA) of plasma were detected; The activity of myocardium MMP-2 was measured by Western blot and RT-PCR.

RESULTSAs compared with I/R group, IPTC could lower the expression of MMP-2, ameliorate left ventricular function and increase the content of myocardium collagenous. In the meantime, the vitality of superoxide dismutase (SOD) of plasma were greatly enhanced and the content of malondialdehyde (MDA) of plasma were reduced in IFC group.

CONCLUSIONProtective effect of IPIC on myocardium may be due to reduce free radical, lower expression of MMP-2 and protect myocardial interstitium. MMPs plays an important role in the myocardial protection provided by IPTC.

Animals ; Collagen ; metabolism ; Ischemic Postconditioning ; Malondialdehyde ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Myocardial Reperfusion Injury ; enzymology ; Myocardium ; metabolism ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

OBJECTIVETo investigate the effects of ischemic postconditioning (IPTC) on the changes of matrix metalloproteinases-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) protein and mRNA levels in rat heart subjected to ischemia/reperfusion, and explore the mechanism by which IPTC protects myocardial interstitium following ischemic/reperfusion (I/R).

METHODSTwenty four healthy male SD rats were randomly divided into 3 groups (n = 8): sham control (SC) group, I/R group and IPTC group. The parameters of left ventricular function including left ventricular systolic pressure (LVSP) and its derivate (±dp/dt) were measured; the amount of myocardial collagen contents was determined by hydroxyproline quantification; the plasma activity of creatine kinase (CK) and lactate dehydrogenase (LDH) was detected; the protien levels of MMP-2 and TIMP-2 was measured by Western blot and the mRNA levels of MMP-2 and TIMP-2 was detected by real-time PCR.

RESULTSThe myocardial collagen contents, left ventricular function and the protein and mRNA levels of TIMP-2 were significantly decreased in I/R group compared with those of SC group, wherease the activities of CK and LDH in the plasma and the protein and mRNA levels of MMP-2 were significantly enhanced in I/R group when compared to SC group. Compared with I/R group, the myocardial collagen contents, left ventricular function and the protein and mRNA levels of TIMP-2 were increased in IPTC group, the activities of CK and LDH in the plasma and the protein and mRNA level of MMP-2 were decreased in IPTC group.

CONCLUSIONThese findings indicate that IPTC has protective effects on myocardial interstitial after the myocardial ischemia/reperfusion injury, and IPTC may exert its cardioprotectve effect via inhibiting MMP-2 and enhancing TIMP-2 expression in cardiac muscle.

Animals ; Collagen ; metabolism ; Creatine Kinase ; metabolism ; Ischemic Postconditioning ; Male ; Matrix Metalloproteinase 2 ; metabolism ; Myocardial Reperfusion Injury ; physiopathology ; Myocardium ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism ; Ventricular Function, Left