0.05),20%(P

OBJECTIVETo investigate the effect of iron on the growth, physiology and photosynthesis of cyanobacteria.

METHODSA gradient of iron concentrations was employed to investigate the growth, photo-pigments (chlorophyll A and phycocyanin), and cell chemical contents (C, N, P) of Microcystis aeruginosa in response to different iron additions.

RESULTSThe specific growth rate during the exponential growth phase, as well as the cell chlorophyll A and the phycocyanin content, was limited by iron below 12.3 tmol Fe x L(-1). The growth was inhibited when the iron concentration was at 24.6 micromol Fe x L(-1). The cell chlorophyll A and the phycocyanin content were saturated when the iron concentration was above 12.3 micromol Fe x L(-1) and declined slightly at 24.6 micromol Fe x L(-1). At a low iron concentration (about 6.15 micromol Fe x L(-1) and less), the cell nitrogen and carbohydrate content were iron limited, and the variation of the cell phosphorus content was similar to that of the nitrogen and carbohydrate, with a transition point of 12.3 micromol Fe x L(-1).

CONCLUSIONThe variation of cynobacteria growth is synchronous with that of the photo-pigments or the cell chemical content, and there exist relationships among photosynthesis, growth and internal chemical content, which could be useful for the growth estimation from the cell characteristics.

Carbohydrates ; analysis ; Culture Media ; chemistry ; Dose-Response Relationship, Drug ; Iron ; pharmacology ; Microcystis ; chemistry ; cytology ; drug effects ; physiology ; Nitrogen ; analysis ; Phosphorus ; analysis

This study was aimed to investigate the expression of c-FLIPL, c-FLIPS and DLK1 mRNA in the patients with myelodysplastic syndrome (MDS) and its clinical significance. The mRNA expression of c-FLIPL, c-FLIPS and DLK1 in bone marrow mononuclear cells (BMMNC) of 16 patients with MDS and 3 controls were detected by RT-PCR. The results indicated that the expression of DLK1 mRNA was up-regulated in MDS, including RA and RAEB, as compared with controls (p < 0.05). There was no significant difference in expression of DLK1 between RA and RAEB patients (p > 0.05); the expression of c-FLIPL mRNA both in RA and RAEB patients was higher than that in controls (p < 0.05). There was no significant difference in expression of c-FLIPL between RA and RAEB patients (p > 0.05); the expression of c-FLIPS mRNA was not significantly different between MDS patients and controls (p > 0.05), but its expression in RAEB patients was significantly higher as compared with RA patients and controls (p < 0.05). It is concluded that the mRNA expressions of DLK1, c-FLIPL and c-FLIPS in MDS patients are abnormal, some of which may be useful as an important indicator for the evaluation of development in MDS.
Aged ; Bone Marrow Cells ; metabolism ; CASP8 and FADD-Like Apoptosis Regulating Protein ; genetics ; metabolism ; Case-Control Studies ; Female ; Gene Expression ; Humans ; Intercellular Signaling Peptides and Proteins ; genetics ; metabolism ; Male ; Membrane Proteins ; genetics ; metabolism ; Myelodysplastic Syndromes ; genetics ; RNA, Messenger ; genetics

To study the effects of sodium valproate (VPA) on human myelodysplastic syndrome cell line MUTZ-1. The cell proliferation was determined by MTT assay, apoptotic morphological features were observed by light microscopy and transmission electronmicroscopy, cell apoptosis and cell cycle shift were analyzed by flow cytometry (FCM). The results showed that VPA could inhibit the growth of MUTZ-1 cells in dose-and time-dependent manners. The typical apoptotic morphological features appeared in MUTZ-1 cells treated with 4 mmol/L VPA for 72 hours. Pyknosis of cells and nuclei, disintegration of nuclear chromatin and apoptotic body could be observed by light microscopy. Aggregation and margination of nuclear chromatin, concentration of plasm, increment of density and chromatin mass of irregular size could be observed by transmission electronmicroscope. The flow cytometric analysis indicated that the VPA could induce cell apoptosis, apoptosis rate increased in dose-dependent manner, ratio of cells at G(0)/G(1) phase increased and ratio of cells at S phase decreased in dose-dependent manner, the cells were arrested at G(0)/G(1) phase. It is concluded that the VPA can induce apotosis and inhibite proliferation of MUTZ-1 cells via arresting cells at G(0)/G(1) phase.
Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line ; Dose-Response Relationship, Drug ; Humans ; Myelodysplastic Syndromes ; pathology ; Valproic Acid ; pharmacology

BACKGROUNDOur previous in vivo study in the rat demonstrates that Shenfu injection, a clinically used extract preparation from Chinese herbs, attenuates neural and cardiac toxicity induced by intravenous infusion of bupivacaine, a local anesthetic. This study was designed to investigate whether bupivacaine could induce a toxic effect in primary cultured mouse spinal cord neuron and if so, whether the Shenfu injection had a similar neuroprotective effect in the cell model.

METHODSThe spinal cords from 11- to 14-day-old fetal mice were minced and incubated. Cytarabine was added into the medium to inhibit the proliferation of non-neuronal cells. The immunocytochemical staining of beta-tubulin was used to determine the identity of cultured cells. The cultured neurons were randomly assigned into three sets treated with various doses of bupivacaine, Shenfu and bupivacaine + Shenfu, for 48 hours respectively. Cell viability in each group was analyzed by methyl thiazoleterazolium (MTT) assay.

RESULTSThe viability of the cultured neurons treated with bupivacaine at concentrations of 0.01%, 0.02%, 0.04% and 0.08% was decreased in a dose-dependent manner. Although the Shenfu injection at concentrations ranging from 1/50 to 1/12.5 (V/V) had no significant influence on the viability of cultured neurons (P < 0.05 vs control), the injection significantly increased the cellular viability of cultured neurons pretreated with 0.03% bupivacaine (P < 0.05).

CONCLUSIONAlthough Shenfu injection itself has no effect on spinal neurons, it was able to reduce the bupivacaine-induced neurotoxicity in vitro.

Anesthetics, Local ; toxicity ; Animals ; Bupivacaine ; toxicity ; Cell Survival ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; administration & dosage ; therapeutic use ; Injections ; Mice ; Neurons ; drug effects ; Spinal Cord ; cytology ; drug effects

This study was aimed to establish a cytokine-independent human myelodysplastic cells line from bone marrow of a patient with MDS-CMML. This cell line was incubated in mixed culture of RPMI 1640 and DMEM with 15% bovine serum, but without cytokines; its biological characteristics were identified by morphology, surface marker profiles, cell proliferation, differentiation and apoptosis. The results showed that the established cell line could not depend on cytokines for long-term survival and growth, and could differentiate into colony-forming unit-macrophage, colony-forming unit-megakaryocyte. In conclusion, a cytokine-independent human myelodysplastic syndrome cell line, named MDS-JSN04 (MDS Nanjing Jiansu 04), was established. Its partial biological characteristics were identified and clarified.
Antigens, CD19 ; analysis ; Antigens, CD20 ; analysis ; Apoptosis ; drug effects ; Bone Marrow Cells ; metabolism ; pathology ; ultrastructure ; CD79 Antigens ; analysis ; Cell Differentiation ; drug effects ; Cell Line ; Cell Proliferation ; drug effects ; Culture Media ; pharmacology ; Cytokines ; pharmacology ; Flow Cytometry ; HLA-DR Antigens ; analysis ; Humans ; Lewis X Antigen ; analysis ; Male ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Middle Aged ; Myelodysplastic Syndromes ; metabolism ; pathology ; Sialic Acid Binding Ig-like Lectin 2 ; analysis ; Time Factors

This study was aimed to investigate the effects of low frequency and power ultrasound combined with adriamycin on apoptosis of drug-resistant leukemia cell line K562/A02 in vitro, to find out the parameters of optimal exposure, and to explore the possible mechanism reversing drug-resistance of K562/A02 cells. The K562/A02 cells in logarithmic growth phase were used in experiments. The experiments were divided into 4 groups: group control, group adriamycin (A02) alone, group ultrasound (US) alone and group A02+US. The trypan blue dye exclusion test and MTT assay were used to determine the cell viability; Wright's staining was used to detect the apoptosis; the flow cytometry was used to analyze the drug concentration, and the scanning electron microscopy was used to observe the changes of cell surface. The results showed that the significant differences in cell viability, intracellular adriamycin concentration and changes of cell membrane were found between ultrasound-treated and untreated cells in the presence of various concentration of adriamycin. The exposure to ultrasound at 20 kHZ, 0.25 W/cm2 for 60 seconds could obviously decrease LC50 of adriamycin to K562/A02 cells, while the exposure to ultrasound at 20 kHZ, 0.05 W/cm2 for 60 seconds could kill K562/A02 cells at once. After being treated by low frequency ultrasound, the small holes with diameter about 1-2 microm in the cell surface appeared. The ultrasound increased the adriamycin concentration in the cells, accelerated the formation of apoptotic bodies, and promoted apoptosis of adriamycin-resistant cells. It is concluded that the ultrasound at optimal parameters enhances inhibitory effect of adriamycin on drug-resistant cell line, thereby reverses drug-resistance of drug-resistant cell line through sound-hole effect in tumor cells resulting from ultrasound induced cavitation.
Doxorubicin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Humans ; K562 Cells ; Ultrasonics

This study was aimed to investigate the effects of gambogic acid on the cells of high-risk patients with myelodysplastic syndrome (MDS) in vitro and its mechanism. The inhibition effect of gambogic acid on growth of MUTZ-1 cell line of MDS-RAEB was detected by MTT method. Apoptosis and cell cycle were detected by morphological observation and flow cytometry respectively. The expressions of bax/bcl-2 gene at mRNA level were detected by RT-PCR. The results indicated that the Gambogic acid inhibited the growth of MUTZ-1 cells, the inhibitory rate of gambogic acid with the range of 0.2 - 0.8 microg/ml was enhanced along with increasing of drug concentration. Flow cytometric assay showed that the apoptotic rate of MUTZ-1 cells treated by gambogic acid also was enhanced along with increasing of drug concentration, the apoptotic rates resulting from gambogic acid (0, 0.4, 0.6, 0.8 microg/ml) were (5 +/- 0.5)%, (13 +/- 0.5)%, (37 +/- 0.7)% and (56 +/- 0.6)% respectively. The characteristic changes of apoptosis emerged in MUTZ-1 cells after being exposed to gambogic acid. Gambogic acid could significantly down-regulate the expressions of bcl-2 gene in a dose dependent manner, however, it had no effects on bax gene. It is concluded that within the range of concentration from 0.4 to 0. 8 microg/ml, gambogic acid can inhibit the growth of MUTZ-1 cells by inducing their apoptosis and down-regulating the expression of bcl-2 gene, which may be one of the main mechanisms underlying its antitumor effects.
Apoptosis ; drug effects ; Cell Line ; Flow Cytometry ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; RNA, Messenger ; genetics ; Xanthones ; pharmacology ; bcl-2-Associated X Protein ; genetics

BACKGROUNDPrior research about N400 has been mainly based on English stimuli, while the cognitive processing of Chinese characters is still unclear. The aim of the present study was to further investigate the semantic processing of Chinese idioms.

METHODSEvent related potentials (ERP) component N400 was elicited by 38 pairs of matching (congruent) and mismatching (incongruent) ended Chinese idioms: ending words with same phoneme but different shape and meaning (sPdSdM), with similar shape but different phoneme and meaning (sSdPdM), with same meaning but different phoneme and shape (sMdPdS), and words with different phoneme, shape and meaning (dPdSdM) and recorded by Guangzhou Runjie WJ-1 ERP instruments. In 62 right-handed healthy adults (age 19 - 50 years), N400 amplitudes and latencies were compared between matching and mismatching conditions at Fz, Cz and Pz.

RESULTSN400 showed a midline distribution and could be elicited in electrodes Fz, Cz and Pz. The mean values of N400 latencies and amplitudes were obtained for matching and mismatching ending words in healthy adults. Significant differences were found in N400 latencies and amplitudes in matching and mismatching ending-words idioms in healthy adults (P < 0.05). Compared with matching ending-words idioms, N400 latencies were prolonged and the amplitudes were increased in mismatching ones. N400s elicited by different types of stimuli showed different latencies and amplitudes, and longest N400 latency and largest N400 amplitude were elicited by ending-words with dPdSdM. No gender difference was found of N400 latency and amplitude in this study (P > 0.05).

CONCLUSIONSCompared with English stimuli, Chinese ideographic words could provide more flexible stimuli for N400 research in that the words have 3-dimension changes - phoneme, shape and meaning. Features of N400 elicited by matching and mismatching ending words in Chinese idioms are mainly determined by the meaning of the word. Some issues of N400 elicited by Chinese characters deserve further research.

Adult ; Cognition ; Evoked Potentials ; physiology ; Female ; Humans ; Male ; Middle Aged ; Reaction Time ; Reading ; Semantics ; Sex Characteristics

This study was aimed to explore the potential therapy of Gambogic acid (GA) combined with magnetic nanoparticle of Fe3O4 (Fe3O4-MNP) on leukemia. The proliferation of U937 cells and the cytotoxicity were evaluated by MTT assay. Cell apoptosis was observed and analyzed by microscopy and flow cytometry respectively. The expressions of gene and protein were detected by quantitative real-time polymerase chain reaction and Western blot respectively. The results showed that GA enhanced the cytotoxicity for U937 cells in dose- and time-dependent manners. The Fe3O4-MNP itself had not cytotoxicity, but could enhance the inhibitory effect of GA on proliferation of U937 cells. The apoptotic rate of U937 cells induced by combination of GA with Fe3O4-MNP was higher than that by GA alone. The typical apoptotic features of cells treated with GA and Fe3O4-MNP were observed. The expression levels of caspase-3 and bax after co-treatment of GA and Fe3O4-MNP were higher than that exposed to GA or Fe3O4-MNP alone, but the expressions of bcl-2, NF-kappaB and survivin were down-regulated. It is concluded that Fe3O4-MNP can promote GA-induced apoptosis in U937 cells, and the combination of GA with Fe3O4-MNP may be a safer and less toxic new therapy for leukemia.
Apoptosis ; drug effects ; Humans ; Iron Compounds ; administration & dosage ; pharmacology ; Magnetics ; Nanoparticles ; U937 Cells ; Xanthones ; pharmacology