Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.
3T3 Cells ; Animals ; Biocompatible Materials ; Chitosan ; chemistry ; Delayed-Action Preparations ; Drug Carriers ; chemistry ; Durapatite ; chemistry ; Lysostaphin ; pharmacology ; Materials Testing ; Methicillin-Resistant Staphylococcus aureus ; Mice ; Microscopy, Electron, Scanning ; X-Ray Diffraction

The epitope-G1 gene of Bovine ephemeral fever virus (BEFV) glycoprotein was synthesised by PCR and cloned into expression vector pPIC9K to construct recombinant plasmid pPIC9K-G1. Then the pPIC9K-G1 was linearized and transformed into Pichia pastoris GS 115. The recombinant P. pastoris strains were selected by a G418 transformation screen and confirmed by PCR. After being induced with methanol, an expressed protein with 26 kDa molecular weight was obtained, which was much bigger than the predicted size (15.54 kDa). Deglycosylation analysis indicated the recombinant G1 was glycosylated. Western blot and ELISA tests, as well as rabbit immunization and specificity experiments indicated that the target protein had both higher reaction activity and higher immunocompetence and specificity. The recombinant G1 protein could be used as a coating antigen to develop an ELISA kit for bovine ephemeral fever diagnosis.

The DNA fragment sized 2 139bp, the same Sequence with AtKup1 gene from Arabidopsis thalianna was used as the templates for DNA family shuffling. The shuffeld AtKup1 gene library was expressed in the mutant of 5. cerevisae in which potassium transporter gene TRK1 and TRK2 were knocked out by homologous recombination. Then the screening was carried out in the low potassium media containing 5. 0 mmol/L KC1 and no histidine in it. it was found that both of diverse and wild AtKup1 gene can rescues the trk1△trk2△yeast mutant strain in low [ K + ] medium. The growth of 2 clones yeast containing diverse AtKup1 were beter than that of AtKup1 wild gene transformant. The sequencig results of the shuffeld AtKup1 showed that there were 2 nucleotide changed, which resulted in 2 amino acid variations in it compared with the original AtKup1. The potassium uptaking capacity of shuffled AtKup1 gene increased significantly when it was transformed into tobacco.

OBJECTIVETo study the molecular mechanism of apoptosis of leukemic cells (K562 cells) induced by iron chelating agent deferoxamine (DFO).

METHODSThe exponentially growing K562 cells were used (1×10(6)/mL) in this study. The K562 cells were treated with different concentrations of DFO (10, 50 and 100 mmol/L), DFO+FeCl3 (10 μmol/L each) or normal saline (blank control). The cellular labile iron pool was measured with a fluorimetric assay using the metalsensitive probe calcein-AM. The viable count and cell viability were determined by typanblue assay. Cell apoptosis was determined by morphological study and flow cytometry assay. Caspase-3 activity in K562 cells was detected by colorimetry.

RESULTSAfter DFO treatment, the cellular labile iron pool and the viability of K562 cells were reduced and the cell apoptosis increased in a time- and dose-dependent manner compared with the blank control group. The apoptosis rate of K562 cells in the DFO+FeCl3 treatment group was not significantly different from that in the blank control group. The caspase-3 activity in K562 cells increased significantly 24 hrs after 50 and 100 μmmol DFO treatment when compared with the blank control group (P<0.01). There was a negative correlation between cellular labile iron pool and caspase-3 activity of K562 cells (r=-0.894, P<0.05).

CONCLUSIONSDFO induces apoptosis of leukemic cells possibly through decreasing cellular labile iron pool and increasing caspase-3 activity of the cells.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Deferoxamine ; pharmacology ; Flow Cytometry ; Humans ; Iron Chelating Agents ; pharmacology ; K562 Cells

Potassium ion channels are a complex of protein molded in the cell membrane lipids. Its expression is strong in normal prostatic epithelia and weak in different degrees in prostatic cancer epithelia, but not clearly known in chronic prostatitis epithelia. Drugs affecting potassium ion channels could provide a new direction and some new ideas for the treatment of prostatic diseases.
Animals ; Humans ; Male ; Mice ; Potassium Channel Blockers ; pharmacology ; therapeutic use ; Potassium Channels ; classification ; drug effects ; physiology ; Prostatic Diseases ; drug therapy ; physiopathology

Objective To investigate the bladder function in primipara and bipara within 1 week after delivery using urodynamic study.Methods Investigations on urodynamic changes were performed in 36 primipara volunteers and 12 bipara volunteers according to the recommendations of the International Continence Society(ICS).Fourteen women with upper urinary tract diseases but having normal lower urinary tract function,who had not experienced parturation were included as controls.Results Functional bladder volume(FBV)of primipara and bipara after delivery and normal desire cytometric capacity (NDCC)were respectively lower than those of control group(437?193)ml and(338?120)ml,however FBV and NDCC between primipara and bipara(310?154),(215?90)ml vs(243?141),(225?115) ml were not significantly different.The static Pure.max and Pure.clos.max of primipara and bipara were respectively higher than those of control group(87?7)cm H_2O(1 cm H_2O=0.098 kPa)and(78?8) cm H_2O(P

Objective To observe the relationship between apoptosis of K562 cell induced by iron-deprivation and activation of Caspase-3.Methods K562 cells were treated with desferrioxamine(DFO) in different dosages were collected at different time points.K562 cells were labelled with Annexin V/PI,and then the rate of apoptosis was measured by flow cytometry;The activation of Caspase-3 were detected by colorimetric method with pAN labelled substrate;The active protein of Caspase-3 were analyzed by Western blot.Results When K562 cells were treated with different concentrations of DFO,the apoptosis rate and the activity of Caspase-3 increases gradually.When K562 cells were incubated with DFO(50 ?mol/L and 100 ?mol/L) 24 h later,the enzymatic activity of Caspase-3 increases dramatically more than that of control group,and the difference was significantly(P0.05).All those effect above can be counteracted by equal mole concentration of FeCl_3.Conclusion Iron-deprivation maybe induce the apoptosis of K562 cell by chelating intracellular iron and activing Caspase-3.

Objective To investigate the accuracy and comparability of ?-glutamyltransferase (?- GT) measurement results on human serum samples and controI materials before and after calibration with a common human serum calibrator.Methods A human serum calibrator was prepared by pooling fresh serum aliquots and assigning a value for ?-GT with the IFCC reference method.The calibrator together with 5 human serum samples and 10 control samples were sent to 15 clinical laboratories and the sermn and control samples were measured with different analytical systems before and after a calibration with the calibrator.The results were analyzed for biases and interlaboratory variations.Results For the serum samples,the calibration resulted in reductions in biases from -9.0%～-14.2% to -0.8%～-7.9%,and in interlaboratory variations from 6.9%～11.6% to 2.8%～4.4%.No improvement was observed on the control samples.Conclusions Accuracy and comparability of serum ?-GT measurements can be improved by using a common human serum calibrator.Some control materials may not be commutable for human serum in ?-GT measurements.

OBJECTIVETo investigate the regulatory effect of potassium channel blocker (tetraethylammonium [TEA], aminopyridine [4-AP], glibenclamide [Glib]) on the proliferation of SD rat prostatic epithelial cells in vitro.

METHODSThe primary culture was prepared by collagenase dissociation of minced prostatic tissues. Cells were cultured in serum-free prostate epithelial cell growth media and identified by immunocytochemical studies. TEA and 4-AP at the concentration of 1, 5 and 10 mmol/L and Glib at the concentration of 10, 50 and 100 mol/L were added, and after 24, 48 and 72 hours of culturing, a cell column diagram was drawn and the cell number counted. The post-passage cell growth was observed by MTT assay and Hoechst33258 nucleus staining.

RESULTSThe cultured cells showed the typical morphological features of epithelia, with positive stain. MTT assay and Hoechst33258 staining showed that TEA, 4-AP and Glib at the increasing concentration effected different degrees of proliferation of prostatic epithelial cells after 24, 48 and 72 h (P < 0.01).

CONCLUSIONThe potassium channel blocker is a direct physiological regulator of the proliferation of SD rat prostatic epithelial cells.

Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Epithelial Cells ; drug effects ; Male ; Potassium Channel Blockers ; pharmacology ; Prostate ; cytology ; drug effects ; Rats ; Rats, Sprague-Dawley

To explore a rapid and easy method to detect labile iron of pool (LIP) in cells, HL-60 and K562 cells were cultured at a concentration 1 x 10(6)/ml in RPMI 1640 containing 10% heat-inactivated fetal bovine serum. The iron deprivation was induced by adding desferrioxamine (DFO) 10 - 100 micromol/L for 0 - 48 hours. The intracellular LIP was measured by probe calcein-AM. Calcein fluorescence was monitored in 1420 multilabel counter. The results indicated that when HL-60 and K562 cells were incubated with different concentrations of DFO, the calcein fluorescence intensity was higher than that of control group at 12, 24 and 48 hours (P < 0.05). Fluorescence value of representing LIP in DFO groups was lower than that in the control group. In conclusion, DFO can decrease LIP in leukemia cells. The approach used in this study may provide a simple and reliable method for detection of intracellular iron homeostasis.
Cation Transport Proteins ; antagonists & inhibitors ; biosynthesis ; metabolism ; Deferoxamine ; pharmacology ; Fluoresceins ; Fluorescent Dyes ; HL-60 Cells ; Humans ; Iron ; metabolism ; Iron Chelating Agents ; analysis ; metabolism ; Iron-Regulatory Proteins ; metabolism ; K562 Cells