[Effect of Daunorubicin on Release and Procoagulant Activity of Microparticles Derived from Acute Promyelocytic Leukemia Cells].

OBJECTIVE: To investigate the effect of daunorubicin on the number and procoagulant activity of Microparticles derived from acute promyelocytic leukemia(APL) cells. METHODS: APL cells were isolated from bone Marrow of 5 newly diagnosed APL patients, the bone marrow mononuclear cells were collected from 5 patients with iron deficiency anemia as control.APL cells were treated with different concentration of daunorubicin(0.1,0.5,1.0 and 2.0µmol/L) for 24 h. Microparticles were extracted from the cell culture medium for qualitative anaysis of the extracted microparticles.The morphologic features of the microparticles were observed by transmission electron microscopy.The number of microparticles was detected by flow cytometry.The procoagulant activity of microparticles was measured by recalcification time assays. RESULTS: Under a transmission electron microscope, theextracted microparticles took a round or oval morphology with a transparent center,and their diameters were arund 100nm, consistent with the morphological characteristics of microparticles. Compared with bone marrow mononuclear cells-derived microparticles,the counts of the bone marrow APL cells-derived microparticles significantly increased(P<0.05).Daunorubicin increased the shedding of microparticles in a dose-dependent manner(r=0.73,P<0.01).Compared with normal bone marrow mononuclear cells-derived microparticles,bone marrow APL cells-derived microparticles showed higher procoagulant activity(P<0.05).Daunorubicin treatment enhanced the prccoagulant activity of APL cells-derived microparticles which paralleled the increasing drug concentrations(r=-0.78,P<0.01). CONCLUSION: Daunorubicin can promote the release of APL cells-derived microparticles and enhance their related procoagulan activity.

[Isolation, Identification, and Biodegradation Behaviors of a Perfluorooctane Sulfonic Acid Precursor (PreFOSs) Degrading Bacterium from Contaminated Soil].

Transformation of perfluorooctane sulfonate (PFOS) precursors (PreFOSs) is considered an additional source of PFOS in the environment and biota. A PreFOSs-degrading bacterium PF1, which was able to utilize PreFOSs as the sole carbon and energy source for growth, was isolated from contaminated soil collected from the surroundings of a fluoride factory. According to its morphology and 16S rDNA gene sequence analysis, strain PF1 was identified as Hyphomicrobium sp. The degradation rates of perfluorooctane sulfonamide (PFOSA) and N-ethyl perfluorooctane sulfonamide (N-EtFOSA) by PF1 were 14.6% and 8.2% (30℃; pH=7.0-7.2), respectively, whereas PF1 was unable to degrade PFOS. PFOSA could be biodegraded to PFOS. N-EtFOSA could be biodegraded to perfluorooctane sulfonamide acetic acid (FOSAA), PFOSA, and PFOS; PFOS was the predominant metabolite. Based on the above analysis, the proposed metabolic pathway of PFOSA by strain PF1 is deamination to form PFOS. Two possible degradation pathways are proposed for N-EtFOSA: ① deethylation of N-EtFOSA to produce PFOSA, followed by deamination to form PFOS, and ②oxidation of N-EtFOSA to FOSAA followed by sequential dealkylation to produce PFOSA, and then transformation to PFOS by deamination.

Production of acteoside from Cistanche tubulosa by ß-glucosidase.

Acteoside and echinacoside are the major active components of Herba Cistanches. Facilitated ß-glucosidation was investigated as a means of increasing harvest of acteoside from Cistanche tubulosa. Fresh Cistanche tubulosa was treated by microwave moisture processing to inactivate enzymes. ß-Glucosidase is capable of hydrolyzing echinacoside for the production of acteoside, so six ß-glucosidases were compared for their efficiency, specific activities and kinetic parameters for conversion to acteoside. The acteoside and echinacoside content was found to be higher after microwave processing than by other previously reported methods. The results showed that ß-glucosidase isolated from microorganisms (Trichoderma sp.) had highly specific activity towards echinacoside, and there was a 4.83 fold increase in the concentration of acteoside after an incubation period of 2 h. This is the first report of the potential application of ß-glucosidases for the facilitated conversion of echinacoside to acteoside in Herba Cistanches extract.

[Deformation evaluation of ProTaper nickel-titanium rotary instruments in curved canals instrumentation in vitro].

OBJECTIVE: To evaluate the deformation of ProTaper rotary instruments using in root canals of different curvature in vitro. METHODS: Extracted first mandibular molars were divided into two experimental groups according to the curvature of mesial buccal canals: group A with moderate curvature and group B with severe curvature. Only the mesial buccal canals of all these teeth were prepared with 6 sets of new ProTaper rotary instruments individually. Additionally, the control group was established with a set of new ProTaper rotary instruments. After finishing each canal preparation, the instruments accompanied by control were examined under the stereomicroscope by an inspector without knowing the group. If distortion, unwinding, abrasion or fracture occurred within one set of instruments, then the whole set was disposed. The sets without problems were in use until 30 times. After 5, 10, 20 times canal preparation, S1, F1 files without deformation under stereomicroscope were examined under scanning electron microscope (SEM). RESULTS: Deformation of ProTaper rotary instruments happened after 12 times in group A and after 7 times in group B. In these two experimental groups, microcracks were found increasing with the times of use under SEM in the instruments without deformation under stereomicroscope. The microcracks on tip of instruments were deep in the early use and became smoother after 10 times. Similar changes happened on knife-edge of instruments, and the microcracks extended over the edge after 20 times use. CONCLUSION: Root canals with severe curvature tend to damage ProTaper rotary instruments more frequently than moderately curved canals. ProTaper rotary instruments are appropriate to treat less than 7 root canals with severe curvature or 12 root canals with moderate curvature. Stereomicroscope is recommended to detect early damages on Ni-Ti rotary instruments, for preventing instruments fracture in clinic.

Distribution of nucleosides and nucleobases in edible fungi.

A gradient reversed-phase high-performance liquid chromatography (HPLC) method was developed for the simultaneous determination of seven nucleosides, adenosine, cordycepin (3'-deoxyadenosine), cytidine, guanosine, thymidine, uridine, and inosine, and five nucleobases, adenine, cytosine, thymine, uracil, and hypoxanthine in Cordyceps sinensis, Cordyceps militaris, Ganoderma lucidum, Agrocybe aegerita, Termitornyces albuminosus, and Lentinus edodes. The results showed that total nucleoside and nucleobase contents ranged from 0.14 to 26.57 mg/g dry matter in these fungi. The higher total nucleoside and nucleobase levels (>10 mg/g dry matter) were found in the gills and the pilei of A. aegerita and T. albuminosus, and the gills of L. edodes. The lower levels (<1 mg/g dry matter) were detected in the stipe and the pileus of G. lucidum. The results indicated that A. aegerita, T. albuminosus, and L. edodes had much higher contents of nucleosides and nucleobases than C. sinensis, C. militaris, and G. lucidum. It is notable that the hymenophore tissues, which contained the spore-producing cells, such as the gills for A. aegerita, T. albuminosus, and L. edodes, the tubes for G. lucidum, and the perithecia for C. sinensis, were found to have considerably higher amounts of total nucleosides and nucleobases as compared to other parts of these fungi.