Objective: To research the activity of antibacterial proteins isolated from Musca domestica during larvae-pupae metamorphosis. Methods: The 5-day-old larvae of Musca domestica were injured with a needle. 24h later, the larvae which had changed into pupae were selected. The antibacterial protein was isolated by a four-step protocol including grinding, heating, CM-sepharose F. F. cationexchange chromatography and another CM-sepharose F. F. chromatography. Antibacterial activities of samples were tested by an ultrasensitive radial diffusion assay using Staphylococcus aureus as the indicator organism. The molecular weight of the isolated protein was determined by SDS-PAGE.Results: The molecular weight of this isolated protein was 43kDa, and its antibacterial activity was strong. Conclusions: A kind of protein with strong antibacterial activity can be produced in the Musca domestica during larvae-pupae metamorphosis.

Response Surface Methodology was applied to optimize the culture components for lipopeptide production by Bacillus natto TK-1. In the first step, two level factorial design of Plackett-Burman was used to evaluate the influence of six related factors. It showed that three factors playing the important roles in the medium, including peptone, yeast extract powder and CaCl_2. The path of steepest ascent was used to approach the optimal region of the fermentation conditions subsequently. In the third step, the concentrations of those three main factors were further optimized by using Box-Behnken and Response Surface Analysis. By solving the quadratic regression model equation, the optimal concentrations of the variables were determined as: peptone 1.73%, yeast extract powder 0.063 %, CaCl_2 1.385?10-4mol/L. Under the optimal culture conditions, the diameter of haemolysis zone increased 29.3 % than before. HPLC analysis showed the precise production of lipopeptide was 30.2% higher than preliminary culture. Furthermore, at three batches cultivation, the experiment values under the optimal conditions agreed with the predictive values. It showed that Response Surface Methodology was proper and a good choice for optimization.

Fermentation for Eicosapentaenoic Acid(EPA) production by Nitzschia laevis at various temperature between 10℃ and 30℃ was investigated and the dynamics characteristics during fermentation process were also analyzed.Based on the results,a varying temperature nursing method of two stage control strategy is proposed:During the first stage,which comprises the delay phase and the initial index phase,the temperature is maintained at 25℃;then the temperature is shifted to 20℃ and kept up till the end of the fermentation process.By this method,a EPA content of 6.0% and a yield of 291.60 mg/L have been gained.These are 24.07% and 18.81% higher than that of fixed temperature(25℃) fermentation,respectively.

This thesis aimed at the Bacillus natto TK-1 screened out from Natto.The lipopeptide was purified using Thin-Layer Chromatography(TLC),and investigated its anti-tumor activity.After acid precipitation and methanol extraction,the lipopeptide was separated on TLC.Then the authors get the monomer surfactin which molecular weight is 1036Da through the High performance liquid chromatography(HPLC),electro spray ionization-mass spectrometry(ESI-MS) and infrared(IR).MTT method was implied to testify the anti-tumor activity of the purified sample from TLC.The results indicated a concentration and time-dependent relationships.After 48h,their IC50 were 40 mg/L.The detection with inverted microscope fluorescence microscope displays that the surfactin will cause a series of Morphological changes to the cells.In TUNEL experiment,the authors noticed that surfactin has the ability to induce apoptosis,besides this inhibition shows an obvious time-dependent relationship.

The study was to develop cis-dichlorodiammineplatinum(DDP)-loaded formulations using a novel type of self-assembled compound composed of block copolymers synthesized by poly(?-glutamic acid)(?-PGA).For the potential of targeting liver cancer cells,D-galactose was conjugated on the prepared ?-PGA.In vitro,DDP can be released from the resulting conjugate in PBS:there was a burst release during the first 8 h,then followed by sustained release.DDP could be easily incorporated into poly(?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond.The yield of DDP incorporation into the esterifiable derivative was 9.4%～10.2%.In vitro experiments conclusively established that the poly(?-glutamic acid)-D-galactose esterifiable derivative-Cisplatin Complex Compound(?-D+-DDP)was much less toxic to normal cell lines than DDP only.The surviving rate of cells treated with ?-D+-DDP compound is higher than those treated with free DDP.Also it has obvious antitumor efficiency on human liver tumor BEL-7402 cells.HE staining indicated that the ?-D+-DDP compound make the BEL-7402 apoptosis.These results indicated that the conjugation of DDP to the esterifiable derivative reduced its cytotoxicity activity,but retains its antitumor activity in vitro.In conclusion,the ?-D+-DDP compound could be used as a potential clinic antitumor drug.The ?-PGA obtained by fermentation can be used as a valuable drug carrier system.

DDP could be easily incorporated into poly (?-glutamic acid)-D-galactose esterifiable derivative through a covalent bond. The yield of DDP incorporation into the ?-PGA was 9.4%～10.2%. The DDP was released in the initial 8h in a burst manner,and thereafter in a sustained manner. The results that the conjugation of DDP to poly (?-glutamic acid)-D-galactose esterifiable derivative not only reduced the toxicity of the DDP but also enhanced antitumor activity and the targeting ability. The vivo experiments conclusively established that the ?-D+-DDP compound was much less toxic to animals than DDP alone. A direct evaluation showed that mice treated with ?-D+-DDP compound at a dose of 7.5 mg/kg displayed significant tumor regression. Furthermore,the implanted solid tumors disappeared completely from 35% of the H22 tumor-bearing mice after ?-D+-DDP compound administration. The aforementioned results of biodistributions of the prepared ?-D+-DDP compound in various organs in normal mice demonstrated that the ?-D+-DDP compound had a specific interaction with liver's parenchymal cells and H22 hepatocellular carcinoma tumor cells via ligand receptor recognition. In conclusion,the results indicated that the ?-D+-DDP compound prepared can effectively target the site of hepatoma tumor via the recognition and significantly reduce its size. The ?-D+-DDP compound was less toxic than the free DDP,and could effectively reduce xenografted H22 hepatocellular carcinoma cells in KM mice and prolong the survival of KM mice grafted with H22 hepatocellular carcinoma tumor cells. Therefore,the prepared ?-D+-DDP compound may be used as a potential drug delivery system for the targeted delivery to liver cancers or other liver diseases.

Astrocytes maintain homeostasis of neuronal microenvironment, provide metabolic and trophic support to neurons and modulate neuronal responses to injury. Rotenone specifically inhibits mitochondrial complex I, and long exposure to rotenone may increase the risk for Parkinson's disease (PD) and cause Parkinsonism. However, little is known about the role of astrocytes in the process of rotenone-induced dopaminergic neuron injury. In order to investigate this issue, we used MN9D cells as a cell model of dopaminergic neurons and rotenone as a toxin to initiate mitochondrial deficiency. MN9D cells treated with the normal medium or astrocyte-conditioned medium (ACM) were exposed to different concentrations of rotenone for different time followed by cell viability measurement by MTT assay. Besides, various concentrations of ACM and temporally different treatments were devised to evaluate protective efficiency of ACM. Growth curve of cells in the normal medium or ACM was continuously assessed by cell counting for 8 d. The influence of rotenone and ACM on cellular oxidative stress was determined by DCFH-DA staining followed by flow cytometric analysis. Glutathione (GSH) content after treatment of ACM or rotenone was measured by GSH assay kit. Our results showed that rotenone decreased viability of MN9D cells in a dose-dependent manner and ACM treatment significantly attenuated rotenone toxicity at each concentration. No significant difference in growth rate was observed between the normal medium and ACM treatment. Four concentrations of ACM, namely 1/3ACM, 1/2ACM, 2/3ACM and pure ACM, all displayed protection, increasing cell viability to (124.15+/-0.79)%, (126.59+/-0.82) %, (125.84+/-0.61) % and (117.15+/-1.63) % of the cells exposed directly to rotenone, respectively. Treatment with ACM through the whole experiment except the initial 24 h, 24 h before or at the same time of rotenone addition all exerted protective effects, with cell viability being (110.11+/-2.52)%, (113.30+/-2.36) %, (114.42+/-2.00)% of the cells exposed directly to rotenone, respectively. Conversely, ACM treatment 12 h after rotenone addition had no protective effect, with cell viability being (102.54+/-1.36)% of the cells exposed directly to rotenone. Moreover, ACM treatment up-regulated GSH level in MN9D cells nearly twofold. Incubation with 100 nmol/L rotenone for 24 h depleted GSH level by nearly two thirds of the control, but ACM treatment mitigated the drop of GSH level, maintaining its content at (147.83+/-0.63)% of the control. Consistent with GSH change, rotenone administration resulted in a positive rate of 96.24% of DCF staining, implying a great extent of oxidative stress, whereas treatment with ACM reduced the extent of oxidative stress to a positive rate of 78.31%. Taken together, these findings suggest that astrocytes protect MN9D cells from oxidative stress caused by rotenone, and GSH partially accounts for the protection. Therefore, astrocytes may play a protective role in the process of PD.
Animals ; Astrocytes ; physiology ; Cells, Cultured ; Cytoprotection ; Glutathione ; analysis ; physiology ; Neurons ; drug effects ; metabolism ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Rotenone ; toxicity

Objective To evaluate left ventricular(LV)myocardial contraction patterns and function when pacing in different right ventricular(RV)sites and discuss echocardiogarphic method to evaluate physiologcal pacing mode.Methods This study included 26 patients with paroxysmal supraventricular tachycardia without organic heart disease.Four pacing modes including right atrium pacing(AAI),RV apex pacing(VVI-RVA),RV septal pacing(VVI-IVS)and RV outflow tract pacing(VVI-RVOT)were performed on the patients in a random order after succussful radiofrequency ablation.The parameters measured in each pacing mode included(1)LV systolic function parameters:LV twist angle(Twist),aortic systolic velocity-time integral(VTIAo)and LV global strain(Gε)；(2)LV contracting pattern:segmental peak systolic strain(Sε),the time to peak value(TPε),and the distribution of segmental Sε,TPε in each layer or wall.The relationship between Sε,TPε of each wall was analyzed.[Results]Pacing from RV sites showed lower Twist,VTIAO and Gε than AAI mode.Gε demonstrated significant difference in three RV sites pacing mode(VVI-RVOT＞VVI-IVS＞VVI-RVA,P＜0.05).Compared with the AAI mode,the distribution of segmental Sε,TPε in the each layer or wall alerted significantly in three RV sites pacing mode,especially in VV1-RVA.The distribution pattern was similar in VVI-RVOT and VVI-IVS.Furthermore,the wall Sε collated negtively with wall TPε(r =-0.51,P＜0.001).[Conclusions]Compared with AAI mode,RV pacing,especially the VVI-RVA induced the alternation of LV contraction patterns and reduction of systolic function.Longitudinal strain parameters can be used to assess the myocardial contraction patterns and function in different pacing mode.

OBJECTIVEIn oder to treat periodontitis by using tissue engineering and gene engineering technology, the article established an transient expression system of bone marrow stromal cells (BMSC) modified by osteoprotegerin (OPG) gene and detected its expression using eukaryotic secreted expression pSecTag2/B-OPG plasmid.

METHODSBy solation and culture of BMSC in vitro, the identified recombined plasmid was transiently transfected into BMSC by Lipofectamine 2000 and OPG expression in BMSC was determined by RT-PCR and Western blot in 6 weeks.

RESULTSThe fragments of the recombinant plasmid digested with Hind III, EcoR I and BamH I and examined by 10 g/L agarose electrophoresis, were consistent with predicted size. The sequence of OPG was identical to the sequence provided by GeneBank [gi:33878056]. OPG transcribing in BMSC was confirmed by RT-PCR and OPG sustainable expressing in BMSC was detected by Western blot in 39 days.

CONCLUSIONThe transiently expression system of BMSC modified by OPG gene was successfully established.

Abstract: Objective　To analyze the influencing factors of mother-to-child transmission of hepatitis B virus after combined immunological blockade, and to evaluate the effect of mother-to-child blockade, and to provide a basis for health policies and health interventions for preventing mother-to-child blockade of hepatitis B virus. Methods A total of 11 363 pairs of HBsAg positive pregnant women and their infants aged 7-12 months in Hainan Province from 2015 to 2020 were included in the study. The general situation, the situation of health care and delivery in this pregnancy and perinatal period, the detection of hepatitis B markers, the situation of antiviral therapy, the general situation of mother and infant during delivery and the implementation of blockade measures for mother-to-child transmission of hepatitis B were collected and analyzed. Results Among the 11 363 pairs of HBsAg positive pregnant women and their infants delivered in hospitals in Hainan province from 2015 to 2020, the positive rate of HBsAg in children at 7-12 months after birth was 1.47 %, and the difference in HBsAg positive rate of infants born in different years was not statistically significant (P>0.05). There were no significant differences in the positive rate of HBsAg among children born to pregnant women with different nationalities, educational levels, occupations, delivery modes, delivery places, obstetric operations and perineal laceration, abnormal perinatal period, children with different genders and premature delivery and perinatal (all P<0.05). There was significant difference in HBsAg positive rate among infants born to pregnant women of different ages, the positive rate of HBsAg of infants born to young pregnant women was higher than that of older pregnant women (P<0.05). The rate of antiviral therapy was low in HBeAg positive pregnant women, and the positive rate of HBsAg in their infants was 2.54%, which was higher than 0.83% in HBeAg negative pregnant women (P<0.05). Conclusions Combined immunological blockade with hepatitis B vaccine and hepatitis B immunoglobulin can effectively prevent the mother-to-child transmission of HBV. HBsAg-positive women can give birth at the right age, and HBeAg-positive pregnant women can be treated with antiviral therapy to block mother-to-child transmission, providing the important basis for the formulation of hepatitis B prevention and control strategies and measures.