Development of SYBR Green I real-time RT-PCR for the detection of Ebola virus / 病毒学报

In order to establish a rapid and accurate method for the detection of Ebola virus (EBOV), the primers used in SYBR Green I real-time RT-PCR were designed based on the EBOV NP gene sequences published in GenBank. The SYBR Green I real-time RT-PCR was established and optimized for the detection of EBOV. The EBOV RNA that was transcribed in vitro was used as a template. The sensitivity of this method was found to reach 1.0 x 10(2) copies/microL and the detection range was 10(2) - 10(10). No cross reaction with RNA samples from Marburg virus, Dengue virus, Xinjiang hemorrhagic fever virus, Japanese encephalitis virus, Influenza virus (H1N1 and H3N2) and Porcine reproductive and respiratory syndrome virus E genomic RNA was found. The method would be useful for the detection and monitoring of EBOV in China.

Study on phenotypic and genotypic characterization of clinical multidrug-resistant Escherichia coli isolates / 中华流行病学杂志

Objective To study the mechanisms on drug susceptibility and resistance of clinically multidrug-resistant Escherichia coli isolates,to provide information on related treatment.Methods The susceptibility of E.coli strains that isolated from different kinds of samples in the last 3 years on drugs was analyzed by agar dilution test,with strains that exhibiting resistances to cefotuxime,ciprofloxacin and amikacin simultaneously collected for further analysis.Resistant genes which mediate resistance to β-lactamases,fluoroquinolone and aminoglycoside as well as phylogenic type were detected by PCR amplification while genetic relation was analyzed by PFGE.Transferability of resistant plasmids was identified by conjugation test.Results In total,137 multidrug-resistant E.coli isolates were collected.Only 1％ of the isolates exhibited resistance to both imipenem and meropenem while 4％ of the strains were resistant to piperacillin/tazobactam.Most (85％) of the isolates were positive to ESBL and majority of them produced CTX-M.Target substitution and production of methylases were the main mechanisms causing resistance to fluoroquinolones and aminoglycosides respectively.Conclusion The main source of clinical multidrug-resistance was collected from urine samples.Carbapenem and enzyme inhibitor-containing antibiotics seemed to be the available antibiotics that were sentitive to the clinically multidrug-resistant E.coli isolates.

The effects of chronic stress on spatial cognitive ability of different sex mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of chronic stress on spatial cognitive ability in different sex mice.</p><p><b>METHODS</b>Thirty-two adult KM mice were divided into four groups (n=8): male control and chronic stress group, female control and chronic stress group. We used the modified Kaz's methods to build on the chronic stress model of mice, and then used the place navigational testing and the probe trial testing by the Morris water maze to measure the spatial cognitive ability of mice.</p><p><b>RESULTS</b>Following two weeks stress treatment, in the place navigational testing, to male group, the average latency to find the platform in water maze of chronic stress group was longer than that of the control; to female group, the average latency of chronic stress group was shorter than the control. Moreover, the male stress group showed faster swimming speed but longer latency to find the platform. In the probe trial testing the female chronic stress group spent more time in the target quadrant compared to the male chronic stress group.</p><p><b>CONCLUSION</b>Two weeks' chronic stress could impair male mice's spatial cognitive ability, but improve the female's.</p>

Suppressing poly(ADP-ribose)polymerase-1 inhibits tau phosphorylation in HEK293/tau441 cells / 生理学报

The study aimed to investigate the effect of inhibition of poly(ADP-ribose) polymerase-1 (PARP-1) activity on tau phosphorylation in HEK293/tau441 cells and its mechanism. HEK293/tau441 cells were treated with 3-aminobenzamide (3-AB), a PARP-1 inhibitor, at different doses (0.5, 1, 2, 4 mmol/L). After 24 h, the cell morphology was observed under phase contrast microscope, tau phosphorylation level in different sites (tau-1, tau-5, Thr231) and the activity of glycogen synthase kinase 3 (GSK-3) were detected by Western blotting. The results showed: (1) 3-AB at different doses failed to change the morphology of cells; (2) The 3-AB-induced decrease in activity of PARP-1 resulted in increase of unphosphorylation level in tau-1(Ser195/198/199/202) sites; (3) The phosphorylation of tau was decreased in Thr231 site, while the total tau was slightly changed after 3-AB treatment; (4) With the increased phosphorylation of GSK-3 at Ser9 site, the activity of GSK-3 was decreased after 3-AB treatment. The results suggest that the inhibition of PARP-1 by 3-AB could decrease tau phosphorylation in HEK293/tau441 cells probably through decreasing GSK-3 activity.

Inhibition of melatonin biosynthesis activates protein kinase a and induces Alzheimer-like tau hyperphosphorylation in rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase.</p><p><b>METHODS</b>Brain ventricular and intraperitoneal injections were used for haloperidol administration, Western blots for tau phosphorylation, 32P-labeling for PKA and GSK-3 activity, and high performance liquid chromatograph for detection of serum melatonin levels.</p><p><b>RESULTS</b>Haloperidol injection through the lateral ventricle and intraperitoneal reinforcement significantly stimulated PKA activity with a concurrent hyperphosphorylation of tau at M4 (Thr231/Ser235) and PS214 (Ser214) sites. Prior treatment of the rats using melatonin supplement for one week and reinforcement during the haloperidol administration arrested PKA activity and attenuated tau hyperphosphorylation. GSK-3 activity showed no obvious change after haloperidol injection, however, melatonin supplements and reinforcements during haloperidol infusion inactivated basal activity of GSK-3.</p><p><b>CONCLUSION</b>Decreased melatonin may be involved in Alzheimer-like tau hyperphosphorylation, and overactivation of PKA may play a crucial role in this process.</p>