Small RNA interference-mediated ADP-ribosylation factor 6 silencing inhibits proliferation, migration and invasion of human prostate cancer PC-3 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of silencing ADP-ribosylation factor 6 (Arf6) on the proliferation, migration, and invasion of prostate cancer cell line PC-3 and the possible molecular mechanisms.</p><p><b>METHODS</b>Three Arf6-specific small interfering RNA (siRNA) were transfected into cultured prostate cancer cell line PC-3. Arf6 expression was examined by real-time PCR and Western blotting. MTT assay, wound healing assay, and Transwell migration and invasion assay were used to observe the effect of Arf6 silencing on the proliferation, migration, and invasion ability of PC-3 cells. The levels of phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2), ERK1/2, p-AKT, AKT and Rac1 were detected by Western blotting.</p><p><b>RESULTS</b>Transfection of siRNA-3 resulted in significantly decreased Arf6 mRNA and protein expression with inhibition rates of (91.88±3.13)% and (86.37±0.57)%, respectively. Arf6 silencing by siRNA-3 markedly suppressed the proliferation, migration and invasion of PC-3 cells and reduced the expression levels of p-ERK1/2 and Rac1.</p><p><b>CONCLUSION</b>Silencing of Arf6 efficiently inhibits the proliferation, migration, and invasion of PC-3 cells in vitro, and the underlying mechanisms may involve the down-regulation of p-ERK1/2 and Rac1.</p>

Naringin inhibits monocyte adhesion to high glucose-induced human umbilical vein endothelial cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of naringin on monocyte adhesion to high glucose-induced human umbilical vein endothelial cells (HUVECs).</p><p><b>METHODS</b>Cultured HUVECs isolated from human umbilical cords were pretreated with or without naringin and induced with high glucose (33 mmol/L) for 48 h. Human monocyte THP-1 cells, after labeling with BCECF-AM, were co-cultured with the HUVECs for 30 min. The labeled THP-1 cells adhering to HUVECs were observed under fluoroscence microscope, and the inhibitory effect of naringin on the cell adhesion was evaluated by measuring the adhering cell density. Western blot analysis was used to detect the expressions of the adhesion molecules in the HUVECs, and reactive oxygen species (ROS) production in the HUVECs was measured using an oxidation-sensitive fluorescent probe (DCFH-DA). The nuclear extracts of the HUVECs were prepared to examine the expression of nuclear factor-kappa B (NF-kappaB) in the cell nuclei by Western blotting.</p><p><b>RESULTS</b>HUVECs in high-glucose culture showed increased adhesion to THP-1 cells and enhanced expressions of the cell adhesion molecules, which were significantly attenuated by pretreatment with naringin (10-50 microg/ml). High glucose induced DCF-sensitive intracellular ROS production in the HUVECs, and this effect was inhibited by naringin pretreatment of the cells. Naringin also suppressed high glucose-induced increment of NF-kappaB expression in the cell nuclei of HUVECs.</p><p><b>CONCLUSION</b>Naringin can suppress high glucose-induced vascular inflammation possibly by inhibiting ROS production and NF-kappaB activation in HUVECs.</p>

Measurement of brain regional oxygen saturation in neonates in China: a multicenter randomized clinical trial / 中华儿科杂志

<p><b>OBJECTIVES</b>To understand the value of measuring neonatal cerebral regional oxygen saturation (rSO2) using near infrared spectroscopy (NIRS) in assessing cerebral oxygenation, to establish the normal range of neonatal cerebral rSO2 and to collect data of the changes of cerebral rSO2 under certain disease status.</p><p><b>METHODS</b>Nine large hospitals participated in the multicenter randomized clinical trial from Jan 2007 to Apr 2008. Using the NIRS human tissue oximeter (TSAH-100) independently developed in China, the cerebral rSO2 of 223 normal full-term and 95 otherwise healthy preterm neonates without any special disease, was detected at 1, 2 and 3 days after birth, respectively. The cerebral rSO2 of 102 neonates with diseases which may affect the cerebral oxygenation, was also detected during the severe phases. The pulse oxygen saturation (SpO2) measured at the finger tip, and also the arterial oxygen saturation (SaO2) measured by blood gas analysis, which could indicate the oxygen supply of the whole body, were obtained simultaneously. The correlations among cerebral rSO2, pulse SpO2 and arterial SaO2 were analyzed.</p><p><b>RESULTS</b>(1) The cerebral rSO2 of the normal full-term neonates was (62+/-2)%. Cerebral hypoxia was defined as rSO2 lower than 58%. The cerebral rSO2 of the normal full-terms was steady at 1, 2 and 3 days after birth respectively, without any significant differences among them (F=0.610, P>0.05). The cerebral rSO2 of the neonates with diseases was (55+/-7)%, which was significantly lower than that of the normal full-term neonates (t=15.492, P<0.05). (2) The cerebral rSO2 was positively correlated with the SpO2 (r=0.74, P<0.01) and the SaO2 (r=0.71, P<0.01). (3) Under some special diseases, the changes of cerebral rSO2 was asynchronous with those of the SpO2: (1) For 18 cases under severe cerebral damages or under relatively low hemoglobin concentration, the cerebral rSO2 was significantly low (50%-58%), but the SpO2 was still normal (above 90%). (2) During the recovery of some critically ill neonates, the increase of cerebral rSO2 was lagged as compared with that of pulse SpO2. Especially, during the severe phases of 6 cases with multi-organ failure, the SpO2 and the cerebral rSO2 were both significantly low (55%-80% for SpO2, and 44%-50% for cerebral rSO2); when the diseases were alleviated, although the SpO2 recovered to above 85%, the cerebral rSO2 was still significantly low (around 50%). (3) In 3 cases, during the severe phases of serious hypoxic-ischemic encephalopathy (HIE), the cerebral rSO2 significantly increased to 70%-72%, which was significantly higher than the normal value (62%).</p><p><b>CONCLUSIONS</b>The range of cerebral rSO2 of the normal full-term neonates was (62+/-2)%. Cerebral oxygenation can be externally indicated by the rSO2 noninvasively and continuously measured by NIRS, which was positively correlated with traditional pulse SpO2 and arterial SaO2. In some special diseases, the rSO2 measured by NIRS can be helpful for clinical diagnoses and treatments.</p>

Pharmacokinetics and relative bioavailability of ziprasidone tablets in Chinese healthy volunteers / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the pharmacokinetics and bioavailability of ziprasidone tablets in Chinese healthy volunteers.</p><p><b>METHODS</b>A randomized crossover study was performed in 20 healthy volunteers, who received a single oral dose (40 mg) of the test or reference preparation of ziprasidone. Blood samples were collected from the subjects at different time points following the drug administration, and the plasma concentration of ziprasidone was determined using high-performance liquid chromatography. The pharmacokinetic parameters were analyzed by DAS software and the relative bioavailability was calculated according to the formula F=AUC(t)/AUC(r)x100%.</p><p><b>RESULTS</b>For the test and reference preparation, the pharmacokinetics parameter C(max) was 170.7-/+71.3 and 174.4-/+81.6 ng/ml, t(max) 3.73-/+1.87 and 3.69-/+1.84 h, t((1/2)) 5.57-/+1.62 and 5.61-/+1.73 h, AUC(0-t) 1273-/+252.3 and 1296-/+266.9 ng.h.ml(-1), and AUC(0-infinity)1396-/+276.9 and 1407-/+281.5 ng.h.ml(-1), respectively, with the relative bioavailability of (98.3-/+12.6)%. No significant differences were found in the main parameters of the test and reference preparations as analyzed by ANOVA and two- and one-side t-test.</p><p><b>CONCLUSION</b>The test and reference preparation of ziprasidone are bioequivalent.</p>

Establishment of homogeneous time-resolved fluorescence immunoassay for high throughput screening of protein tyrosine kinase inhibitors / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an in vitro homogeneous time-resolved fluorescence immunoassay method for high throughput screening of protein tyrosine kinase (PTK) inhibitors.</p><p><b>METHODS</b>Specific fluorescence signals at 670 and 612 nm were measured by multifunctional microplate reader when the fluorescence was emitted through a resonance energy transfer between fluorescent materials (EuK and XL-665). The inhibitory activity of Sunitinib, a standard PTK inhibitor, on vascular endothelia growth factor receptor 2 (VEGFR-2) kinase activity was investigated.</p><p><b>RESULTS</b>A homogeneous time-resolved fluorescence immunoassay was established for high throughput screening of PTK inhibitor. In this system, the concentrations of VEGFR-2, adenosine triphosphate (ATP) and poly-peptide substrate were 5 ng/microl, 100 micromol/L and 1 micromol/L, respectively. Sunitinib inhibited VEGFR-2 kinase activity with an IC50 value of 86.7 nmol/L, which was close to the values tested using other methods.</p><p><b>CONCLUSION</b>The homogeneous time-resolved fluorescence immunoassay we established can be easily used for high throughput screening of PTK inhibitors.</p>

Evaluation of Amberlite XAD-1600 resin-based purification of the bioactive components from Radix Paeoniae Alba and Rhizoma Curcumae Longae extracts by pharmacodynamic and toxicological models / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the pharmacodynamics and toxicicity of the major bioactive components extracted and purified from Radix Paeoniae Alba and Rhizoma Curcumae Longae using Amberlite XAD-1600 resin.</p><p><b>METHODS</b>Amberlite XAD-1600 was used to purify the bioactive components from the crude 75% ethanol extracts of the two herbs. The pharmacodynamic and toxic effects of the crude extracts and extract purified using XAD-1600 resin were comparatively examined with two acute inflammatory models, two pain models and acute toxicity test in vivo.</p><p><b>RESULTS</b>The anti-inflammatory and analgesic effects of the purified extract were significant stronger with lower toxicity than those of the crude ethanol extract.</p><p><b>CONCLUSION</b>Amberlite XAD-1600 resin allows efficient extraction and purification of the bioactive components from the two herbs.</p>

Measurement of plasma concentration and bioavailability of nolatrexed dihydrochloride in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a methods based on high-performance liquid chromatogram-mass spectrum for measuring the plasma concentration of nolatrexed dihydrochloride and investigate the pharmacokinetic profile and absolute bioavailability of the drug in mice.</p><p><b>METHODS</b>Nolatrexed dihydrochloride were injected intravenously at 50 mg/kg or administered orally at 200 mg/kg in mice, and blood samples were collected at various time points following drug administration. The plasma concentration of nolatrexed dihydrochloride in mice was determined using high-performance liquid chromatogram-mass spectrum. The pharmacokinetic parameters were calculated using DAS software, and the absolute bioavailability of orally and intravenously administered was assessed according to the ratio of their area under the curve (AUC).</p><p><b>RESULTS</b>The method showed good linear relationship within the drug concentration range of 0.01-40 mg/L (r=0.9995, P<0.001). The recovery of nolatrexed dihydrochloride from the mouse plasma was more than 85%, and the intra- and inter-day precision expressed as the relative standard deviation was less than 15%. The half-life (T(1/2)), AUC, distribution factor and plasma clearance (CL) for intravenously administered nolatrexed dihydrochloride (50 mg/kg) were 3.020-/+0.017 h, 89.972-/+0.425 mg/L/h, 0.831-/+0.106 L/kg, and 0.556-/+0.093 L/h/kg, respectively. The T(1/2), AUC, peak time (T(max)) and peak concentration (C(max)) for orally administered drug were 5.046-/+0.191 h, 84.893-/+9.923 mg/L/h, 1.000-/+0.012 h, and 18.000-/+0.0140 mg/L, respectively. The absolute bioavailability of nolatrexed dihydrochloride in mice was 23.58%.</p><p><b>CONCLUSION</b>The absolute bioavailability of nolatrexed dihydrochloride in mice determined in this study provides an experimental basis for development of the oral preparation of the drug.</p>

Inhibitory effect of polysaccharides on the six-alpha-helix bundle formation of HIV gp41 protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the in vitro inhibitory effect of expolysaccharides from Streptomyces, polysaccharides of Ganoderma lucidum and rice bran on six-alpha-helix bundle formation of HIV gp41 protein.</p><p><b>METHODS</b>The amount of six-alpha-helix bundle formed in the presence of N36 and C34 was tested by ELISA in response to treatments with different doses of polysaccharides.</p><p><b>RESULTS</b>Expolysaccharides from Streptomyces potentially inhibited six-alpha-helix bundle formation with the effective concentration (IC(50)) of 145.48-/+7.25 mg /L. Polysaccharides of Ganoderma lucidum and rice bran showed no effect on the six-alpha-helix bundle formation.</p><p><b>CONCLUSION</b>Expolysaccharides from Streptomyces can inhibit the six-alpha-helix bundle formation of HIV gp41, whereas polysaccharides of Ganoderma lucidum and rice bran do not exhibit such activity.</p>

Purification of a new phospholipase A2 homologue from Agkistrodon blomhoffii siniticus and its effects on gene expression profile of Hep3B cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To isolate and purify a new phospholipase A2 (PLA2) homologue from Agkistrodon blomhoffii siniticus and investigate its effects on the gene expression profile of Hep3B cells.</p><p><b>METHODS</b>The PLA2 homologue was isolated and purified by reverse-phase high-performance liquid chromatography (HPLC) and its purity was determined also by HPLC. The relative molecular mass of the homologue was measured by electrospray ionization mass spectrum. The gene expression profile of Hep3B cells was detected with gene chip after exposure of the cells to 139 microg/ml PLA2 homologue for 12 h.</p><p><b>RESULTS</b>The purity of the PLA2 homologue was 97.2%, whose relative molecular mass was 13,900. After exposure of Hep3B cells to 139 microg/ml PLA2 homologue for 12 h, 19 genes were down-regulated and 20 up-regulated in the cells. The genes showing altered expressions in response to the exposure were mainly involved in cell cycle control and DNA damage repair, cell apoptosis and senescence, production of signal transduction molecules and transcription factors, cell adhesion, angiogenesis, and tumor invasion and metastasis.</p><p><b>CONCLUSIONS</b>The PLA2 homologue induces alterations in the expression of a wide variety of genes involved in the growth and metastasis of tumor cells. The results of this study provide clues for further study of the possible mechanism for the action of PLA2 homologue on Hep3B cells.</p>