Bidirectional signal transduction is a newly elucidated mechanism in intercellular communication. The bidirectional signal transduction mediated by the Eph-ephrin is an important representative in this field. The Eph family receptor tyrosine kinases and their membrane-bound ligands, the ephrins, play pivotal roles in the development of nervous system, angiogenesis, etc. The signal transduction into cells by Eph receptors is the forward signal, whereas the signal transduction by ephrins is the reverse signal. Based on their molecular structures, the ephrins can be divided into two subclasses, i.e. ephrinA and ephrinB. The ephrinBs are transmembrane proteins, which can activate FAK, JNK and Wnt signal transduction pathways through phosphotyrosine-dependent signaling and PDZ-binding motif-dependent signaling. The ephrinAs are glycosylphosphotidylinositol (GPI) anchored proteins, which can also mediate reverse signal transduction.

OBJECTIVE:To study the inhibitory effects of emodin on the proliferation of human hepatocellular carcinoma SMMC7721 cells. METHODS:SMMC7721 cells were treated with 0(negative control),25,37.5,50,62.5,75,87.5,100μmol/L emodin solution and 100 μmol/L 5-FU for 24 h,48 h,72 h. The optical density value of cells was detected,and inhibition rate was calculated. SMMC7721 cells were treated with 0 (negative control),25,50,75 μmol/L emodin solution and 100 μmol/L 5-FU for 48 h,and cell apoptosis rate,cell cycle and the expression of Bax and Bcl-2 gene were detected. RESULTS:Compared with negative control,the rate of cell proliferation inhibition increased after treated with 25,37.5,50,62.5,75,87.5,100 μmol/L emodin and 100 μmol/L 5-FU,which was positively associated with the concentration and duration. Compared with negative con-trol,the rate of cell apoptosis increased after treated with 25,50,75 μmol/L emodin solution and 100 μmol/L 5-FU;the expres-sion of Bax increased and that of Bcl-2 dereased;50,75 μmol/L emodin solution and 100 μmol/L 5-FU could arrested cells at G0/G1 phase(P<0.05 or P<0.01). CONCLUSIONS:Emodin can inhibit the proliferation of SMMC7721,promote cell apoptosis and in-hibit cell growth.

The incidence of early neurological deterioration in acute ischemic stroke is higher, and the clinical prognosis is poor. There is no effective specific prevention and treatment now. This article reviews the advances in research on early neurological deterioration in acute ischaemic stroke in recent years.

Objective Patient safety is key to quality of care in hospital management, for which drug safety is critical. General hospitals are challenged with how to monitor drug adverse reaction (ADR), and motivate their staff to report ADRs in building a hospital safety culture. Methods The PDCA cycle quality improvement process was called into play, to set the ADR criteria and analyze data of inpatients' ADRs from 2005 to 2009, which was followed by measures proposed for ADR continuous improvement. Results A total of 2850 ADR cases were reported in the past 5 years, averaging 570 cases per year. The ADR incidence rate was 3. 28%, of which 43 were severe ADR cases, or 0. 49% of the total cases, accounting for 1. 51% of all the ADR cases. Year to year, the quantity and quality of ADR reporting have been improving in the hospital, witnessing an initial culture of drug safety. In 2008, the hospital was awarded as an advanced ADR center in Beijing. Conclusion The PDCA cycle is an effective means for ADR management, as it can improve the awareness of the medical staff for proactive ADR reporting. Sustained circular management against ADRs can minimize risks and maximize patient safety.Under-reporting and the corrective measures shall be watched over by the hospital in the future.

Objective To investigate the values of diffusion tensor MR imaging(DTI)and fiber tractography(FT)in the assessment of cognitive functions in children with periventricular leukomalacia (PVL),to facilitate to understand the mechanism of PVL children's cognitive functions.Methods Forty six children with PVL and 16 age-matched volunters were recruited.Developmental quotient(DQ)of all cases was recorded.According to the DQ scores,patients were divided into 3 groups:mild in 11 patients,moderate in 19,and severe in 16.DTI was performed in all cases and fractional anisotropy(FA)values were be calculated.Non-paired t test was used to compare the FA values of major white matter fibers between patients group and controls group.One-way ANOVA was used to compare the FA values among 4 groups.Results Compared with controls,all 46 patients with PVL showed a significant mean FA reduction in left corticospinal tract(CST)(0.476 ±0.064 vs.0.531 ±0.064),bilateral anterior limb of internal capsula (ICAL)(left 0.357 ±0.050 vs.0.405 ±0.081,right 0.370 ±0.040 vs.0.405 ±0.036),posterior limb of internal capsule(ICPL)(left 0.483 ±0.044 vs.0.546 ±0.091,right 0.485 ±0.046 vs.0.547 ±0.083),arcuate fasciculus(AF)(left 0.367 ± 0.069 vs.0.433 ± 0.097,right 0.363 ± 0.064 vs.0.421 ±0.091),posterior thalamic radiation(PTR)(left 0.390 ± 0.059 vs.0.459 ± 0.067,right 0.382 ± 0.047 vs.0.446 ± 0.064),anterior CG(ACG)(left 0.362 ± 0.056 vs.0.423 ± 0.057,right 0.345 ± 0.056 vs.0.417 ± 0.080),superior longitudinal fasciculus(SLF)(left 0.323 ± 0.050 vs.0.426 ±0.102,right 0.341 ± 0.056 vs.0.416 ± 0.092)and splenium of the corpus callosum(SCC)(0.535 ±0.090 vs.0.606 ±0.060)(t =2.037-3.745,P ＜0.05).The severity of cognitive impairment companied with decrease of the FA values of all fibers.The FA values of bilateral CST,ICAL,ICPL,left AF,bilateral PTR,ACG,SLF and SCC were significantly different among different groups(F =3.021-7.146,P ＜ 0.05).Conclusions The damage widespread of white matter bundles is found in children with PVL DTI and FT can provide details in the assessment of cognitive impairment in children with PVL.

During spermatogenesis, lysine-rich histones in spermatogenic cells are progressively replaced by arginine-rich protamine. In this study, the nucleoprotein transition in spermatogenic cells of Wistar rat was investigated using aniline blue staining, PTA staininig (both to demonstrate lysine-proteins) and NQS (1, 2-naphthoquinone4-sodium sulfonate) staining (to demonstrate arginine-protein). Under light microscope, the nuclei of spermatogonia and spermatocytes were intensely aniline blue positive and the nuclei of young spermatids moderately positive, while the nuclei of late elongated spermatids and spermatozoa were aniline blue negative. The nuclei of spermatogonia and young spermatids were basicallyy NQS negative and there were a few granules of weak NQS positive in the nuclei of primary spermatocytes, while the nuclei of late elongated spermatids and spermatozoa were NQS positive. Under the electron microscope, the PTA positive chromatin in the nuclei of early spermatids with round nucleus (steps 1 to 8)was fibrillar or granular in appearance. Along with the condensation of nuclei of spermatids(steps 9 to 13), the nuclear stain ability increased. The positive chromatin in the nuclei of spermatids (steps 14, 15) was disappeared progressively, in the direction from cranial to caudal along with the further condensation of nuclei. The nuclei of late spermatids with elongated nucleus (steps 18, 19) and spermatozoa were PTA negative. These observations suggest that the nucleoprotein transition from histones to protamine (S_1) occur during spermiogenesis and that this process could be divided into two consecutive steps, i. e. from histones through an intermediate phase of transition proteins to protamine.

AIM:To explore the protective effects of riboflavin on the kidney in streptozotocin (STZ)-induced diabetic rats.METHODS:Male Sprague-Dawley rats were randomly divided into 3 groups:normal control group,diabetic model group and riboflavin-treated group.Diabetes was induced by a single injection of STZ (dissolved in 0.01 mol/L citrate buffer,pH 4.5,65 mg/kg,ip) in rats.The biochemical methods were used to measure the contents of urine protein and malondialdehyde in the kidney,and the activities of superoxide dismutase (SOD) and catalase (CAT) in serum and renal tissues.Furthermore,the protein expression of TGF-?1 and plasminogen activator inhibitor-1(PAI-1) in renal cortex was detected by Western blotting.The morphological changes of renal tissue were observed under microscope.RESULTS:Compared to the diabetic model group,riboflavin significantly increased the activities of SOD and CAT (P

Seizures may be the first or sometimes the only manifestation of patients with glioma in clinics. The aim of operation is to eliminate epilepsy far beyond mere resection of tumor mass. The underlyling mechanisms of glioma-associated epileptogenesis are poorly understood. Recently the theory of amino-acid like neurotransmitters in chemical synapse is gradually accepted. However, the molecular mechanisms remain to be further investigated on how glutamate release is regulated and how synaptic homeostasis in peripheral neurons is kept or disturbed. So detailed studies are needed to clarify specific molecular target and provide proper evidence for optimal antiepileptic drugs in glioma-associated epileptoge-nesis.

AIM: To develop an RP-HPLC method for preparing the reference substanc of vicenin-2 in Desmodium styracifolium. METHODS: Ethanol-extract of desmodium styracifolium was isolated and purified by RP-HPLC combining solvent extraction with column chromatography and recrystalliztion.The purity and content of vicenin-2 were identified by HPLC. RESULTS: The flvonoids were completely separated under this chromatographic condition.The purity of the reference substance was 99.0% or above. CONCLUSION: The method is simple,accurate,better on repeatability,and effective to yield high-purity product.It can be used as reference substance for the research of herbal medicine.

AIM:To explore the effects of the new drug of sulfonylurea(1-{4-[2-(3-ethyl-4-methyl-2-oxo-3-pyrroline-1-carboxamido)ethyl]-phenylsulfonyl}-3-(1,4-tetramethylene)-urea,BGW) on the glucose uptake and the activation of Akt/PKB in SMMC7721 cells.METHODS:Cultured SMMC7721 cells were divided into control group,glibenclamide group,insulin group,BGW group and BGW+insulin group.Scintillation was used to detect the glucose uptake in SMM7721 cells.The activation of Akt/PKB was tested by Western blotting.RESULTS:Compared to control cells,gibenclamide,insulin,BGW and BGW+insulin significantly increased the glucose uptake(P