OBJECTIVETo purify Rhubarb polysaccharides via micro-filtration and ultra-filtration.

METHODThe technology adopted micro-filtration and tubular membrane with different cut-off molecular weights.

RESULTExperiment results showed that the optimum operating conditions were that the ultra-filtration time controlled around 80 min, the temperature was set the 35-40 degrees C, the operating pressure was 0.08-0.12 MPa, the pH was 6-8, and a sample that of polysaccharide was 0.5 times of original concentration. The recovery ratio of the polysaccharides was 53.7%, the concentration could be condensed to 2.73 times compared with the sample liquid.

CONCLUSIONThe technology was simple and feasible, it can be applied to purify Rhubarb polysaccharides.

Feasibility Studies ; Hydrogen-Ion Concentration ; Polysaccharides ; isolation & purification ; Pressure ; Rheum ; chemistry ; Temperature ; Time Factors ; Ultrafiltration ; methods

Yarrowia lipolytica lipase Lip2 (YlLip2) is an important industrial enzyme with many potential applications. To alleviate the dissolved oxygen (DO) limitation and improve YlLip2 production during high-cell density fermentation, the YlLip2 gene lip2 and Vitreoscilla hemoglobin (VHb) gene vgb were co-expressed in Pichiapastoris under the control of AOX1 and PsADH2 promoter, respectively. The PsADH2 promoter from Pichia stipitis could be activated under oxygen limitation. The SDS-PAGE and CO-difference spectrum analysis indicated that VHb and YlLip2 had successfully co-expressed in recombinant strains. Compared with the control cells (VHb-, GS115/9Klip2), the expression levels of YlLip2 in VHb-expressing cells (VHb+, GS115/9Klip2-pZPVT) under oxygen limitation were improved 25% in shake-flask culture and 83% in a 10 L fermentor. Moreover, the VHb+ cells displayed higher biomass than VHb- cells at lower DO levels in a 10 L fermentor. In this study, we also achieved a VHb-expressing clone harboring multicopy lip2 gene (GS115/9Klip2-pZPVTlip2 49#), which showed the maximum lipolytic activity of 33 900 U/mL in a 10 L fermentor under lower DO conditions. Therefore, it can be seen that expression of VHb with PsADH2 promoter in P. pastoris combined with increasing copies of lip2 gene is an effective strategy to improve YlLip2 production.
Bacterial Proteins ; biosynthesis ; genetics ; Fermentation ; Fungal Proteins ; biosynthesis ; genetics ; Lipase ; biosynthesis ; genetics ; Oxygen ; analysis ; pharmacology ; Pichia ; metabolism ; Protein Engineering ; Recombinant Proteins ; biosynthesis ; genetics ; Truncated Hemoglobins ; biosynthesis ; genetics

OBJECTIVETo study the effects of inhibitory peptide of Staphylococcus epidermidis (SE) biofilm (briefly referred to as inhibitory peptide) on adhesion and biofilm formation of SE at early stage.

METHODSBy using peptide synthesizer, the inhibitory peptide was synthesized with purity of 96.8% and relative molecular mass of 874.4. (1) Solution of SE ATCC 35984 (the same below) was cultivated with inhibitory peptide in the final concentrations of 1-256 µg/mL, and the M-H broth without bacteria solution was used as blank control. The MIC of the inhibitory peptide against SE was determined (n=3). (2) Solution of SE was cultivated with trypticase soy broth (TSB) culture solution containing inhibitory peptide in the final concentrations of 16, 32, 64, 128, and 256 µg/mL (set as inhibitory peptide groups in corresponding concentration), and solution of SE being cultivated with TSB culture medium was used as negative control group. Growth of SE was observed every one hour from immediately after cultivation (denoted as absorbance value), and the growth curve of SE during the 24 hours of cultivation was drawn, with 3 samples in each group at each time point. (3) Solution of SE was cultivated with TSB culture solution containing inhibitory peptide in the final concentrations of 16, 32, 64, 128, and 256 µg/mL (set as inhibitory peptide groups in corresponding concentration), and solution of SE being cultivated with TSB culture medium was used as negative control group. Adhesive property of SE was observed after cultivation for 4 hours (denoted as absorbance value, n=10); biofilm formation of SE was observed after cultivation for 20 hours (denoted as absorbance value, n=10). (4) Solution of SE was cultivated with TSB culture solution containing inhibitory peptide in the final concentration of 128 µg/mL (set as 128 µg/mL inhibitory peptide group), and solution of SE being cultivated with TSB culture medium was used as negative control group. Adhesive property of SE and its biofilm formation were observed with confocal laser scanning microscope (CLSM), and the sample numbers were both 3. Data were processed with one-way analysis of variance, LSD test, and Dunnett T3 test.

RESULTS(1) The MIC of inhibitory peptide against SE exceeded 256 µg/mL. (2) There was no significant difference in the growth curve of SE between inhibitory peptide groups in different concentrations and negative control group. (3) After 4 hours of cultivation, the absorbance values of adhesive property of SE in 256, 128, 64, and 32 µg/mL inhibitory peptide groups were respectively 0.20 ± 0.04, 0.27 ± 0.03, 0.35 ± 0.04, and 0.40 ± 0.04, which were significantly lower than the absorbance value in negative control group (0.53 ± 0.10, P<0.05 or P<0.01); the absorbance value of adhesive property of SE in 16 µg/mL inhibitory peptide group was 0.47 ± 0.09, which was close to the absorbance value in negative control group (P>0.05). After 20 hours of cultivation, the absorbance values of biofilm formation of SE in 256, 128, and 64 µg/mL inhibitory peptide groups were respectively 0.49 ± 0.10, 0.68 ± 0.06, and 0.93 ± 0.13, which were significantly less than the absorbance value in negative control group (1.21 ± 0.18, P<0.05 or P<0.01); the absorbance values of biofilm formation in 32 and 16 µg/mL inhibitory peptide groups were respectively 1.18 ± 0.22 and 1.15 ± 0.26, which were close to the absorbance value in negative control group (with P values above 0.05). (4) CLSM showed that more adhering bacteria and compact structure of biofilm were observed in negative control group, but less adhering bacteria and loose structure of biofilm were observed in 128 µg/mL inhibitory peptide group.

CONCLUSIONSThe inhibitory peptide can inhibit adhesion and biofilm formation of SE at early stage, but its structure still needs to be further modified.

Bacterial Adhesion ; Biofilms ; growth & development ; Humans ; Microscopy, Confocal ; Peptides ; Staphylococcus epidermidis ; genetics ; metabolism ; physiology

OBJECTIVETo explore the safety and efficacy of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in preventing chemotherapy-induced neutropenia in patients with breast cancer and non-small cell lung cancer (NSCLC), and to provide the basis for clinical application.

METHODSAccording to the principle of open-label, randomized, parallel-group controlled clinical trial, all patients were randomized by 1∶1∶1 into three groups to receive PEG-rhG-CSF 100 μg/kg, PEG-rhG-CSF 6 mg, or rhG-CSF 5 μg/kg, respectively. The patients with breast cancer received two chemotherapy cycles, and the NSCLC patients received 1-2 cycles of chemotherapy according to their condition. All patients were treated with the combination chemotherapy of TAC (docetaxel+ epirubicin+ cyclophosphamide) or TA (docetaxel+ epirubicin), or the chemotherapy of docetaxel combined with carboplatin, with a 21 day cycle.

RESULTSThe duration of grade 3-4 neutropenia in the PEG-rhG-CSF 100 μg/kg and PEG-rhG-CSF 6 mg groups were similar with that in the rhG-CSF 5 μg/kg group (P>0.05 for all). The incidence rate of grade 3-4 neutropenia in the PEG-rhG-CSF 100 μg/kg group, PEG-rhG-CSF 6 mg group, and G-CSF 5 μg/kg group were 69.7%, 68.4%, and 69.5%, respectively, with a non-significant difference among the three groups (P=0.963). The incidence rate of febrile neutropenia in the PEG-rhG-CSF 100 μg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 μg/kg group were 6.1%, 6.4%, and 5.5%, respectively, showing no significant difference among them (P=0.935). The incidence rate of adverse events in the PEG-rhG-CSF 100 μg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 μg / kg group were 6.7%, 4.1%, and 5.5%, respectively, showing a non-significant difference among them (P=0.581).

CONCLUSIONSIn patients with breast cancer and non-small cell lung cancer (NSCLC) undergoing TAC/TA chemotherapy, a single 100 μg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF at 48 hours after chemotherapy show definite therapeutic effect with a low incidence of adverse events and mild adverse reactions. Compared with the continuous daily injection of rhG-CSF 5 μg/kg/d, a single 100 μg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF has similar effect and is more advantageous in preventing chemotherapy-induced neutropenia.

Antineoplastic Agents ; adverse effects ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; Breast Neoplasms ; drug therapy ; Carboplatin ; administration & dosage ; adverse effects ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; Cyclophosphamide ; administration & dosage ; adverse effects ; Epirubicin ; administration & dosage ; adverse effects ; Female ; Granulocyte Colony-Stimulating Factor ; therapeutic use ; Humans ; Incidence ; Induction Chemotherapy ; Lung Neoplasms ; drug therapy ; Neutropenia ; chemically induced ; epidemiology ; prevention & control ; Polyethylene Glycols ; Recombinant Proteins ; administration & dosage ; Taxoids ; administration & dosage ; adverse effects

Polymyxin B, which is a last-line antibiotic for extensively drug-resistant Gram-negative bacterial infections, became available in China in Dec. 2017. As dose adjustments are based solely on clinical experience of risk toxicity, treatment failure, and emergence of resistance, there is an urgent clinical need to perform therapeutic drug monitoring (TDM) to optimize the use of polymyxin B. It is thus necessary to standardize operating procedures to ensure the accuracy of TDM and provide evidence for their rational use. We report a consensus on TDM guidelines for polymyxin B, as endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society. The consensus panel was composed of clinicians, pharmacists, and microbiologists from different provinces in China and Australia who made recommendations regarding target concentrations, sample collection, reporting, and explanation of TDM results. The guidelines provide the first-ever consensus on conducting TDM of polymyxin B, and are intended to guide optimal clinical use.
Humans ; Anti-Bacterial Agents/therapeutic use* ; China ; Drug Monitoring/methods* ; Polymyxin B ; Practice Guidelines as Topic