A new ionizing-radiation resistant strain WGR702 was isolated from arid soils which had been ra-diated. The strain WGR702 was Gram-positive and coccus, the diameter of the cell was 1.5 ?m～2.5?m.The strain WGR702 was pink-pigmented, motile, facultative anaerobe and non-spore forming. The range tem-perature and pH for strain WGR702 growth were 10℃～35℃ and pH 5.0～10.0 respectively. The strain WGR702 had a G+C content of 60.5 mol%. UV and gamma radiation survival curves showed the strain WGR702 had highly ionizing-radiation resistant. Phylogenetic analysis of the 16S rDNA gene sequences (EU315117) showed 94.79%～98.53% similarities with other recognized Serratia species. Primary charac-teristics that distinguish isolate WGR702 from the species of genus Serratia include the cells are spherical and Gram-positive. Based on the phenotypic, biochemical and physiological characteristics differences it is proposed that the new isolated strain WGR702 might be classified as a novel species of Serratia.

Objective The present study was designed to investigate the efficiency of simvastatin therapy for experimental pul‐monary hypertension (PH) in rat ,and the effects on the number and function of circulating endothelial progenitor cells (EPC) . Methods Twenty four Sprague Dawley rats were divided into 3 groups randomly :model group ,treatment group and control group , 8 rats in each group .Rats were treated with a single subcutaneous injection of monocrotaline to induce PH (PBS used as control) . The rats in the experimental group were administrated with simvastatin 3 days following subcutaneous injection of monocrotaline .In the 21st day ,the number of circulating EPC ,the right ventricle systolic pressure of rat ,pulmonary vascular structural changes and the quantity of cultured EPC were measured .At the same time ,EPC in each group were cultured in vitro ,then the ability of prolif‐eration and function were analyzed and compared .Results The number of circulating EPC in model group was decreased signifi‐cantly compared to both control and model groups (P< 0 .01) .Compared with model group ,simvastatin treatment markedly de‐creased the RVSP and the ratio of media thickness to eternal diameter (P<0 .01) ,but the ratio of vessel area to total arterial area (VA/TAA) was definitively increased(P<0 .01) .After 7 days of culture in vitro ,both the output of EPC and the ability of prolif‐eration ,conglutination and migration of EPC in treatment group were up -regulated compared with those in model group (P<0 .01) .Conclusion This study confirmed that simvastatin effectively treat experimental PH through improving quantity and func‐tion of circulating EPC .

[ Objective] To explore the variation features of contrast enhanced ultrasound ( CEUS) quantitative parameters and its correlation with tumor microvessel density ( MVD ) , after the treatment of living liver cancer using high intensity focused ultrasound ( HIFU ) . [ Methods ] A group of 30 New Zealand white rabbits were made into VX2 liver cancer models, that were randomly divided into control group ( n =15, not HIFU treatment) and treatment group ( n =15, HIFU treatment).CEUS was performed, then obtaining ascending slope(AS),arrival time(AT),time-to-peak(TTP),peak intensity ( PI) ,area under curve ( AUC ) .And correlation analysis was performed with MVD obtained by immune histochemical method. [ Results ] Compared with those in the control group, AS, PI, AUC were significantly decreased in treatment group (P <0.05) and so was MVD (P <0.05).AT,TTP were significantly delayed than those in the control group (P<0.05).The AS, PI, AUC of CEUS quantitative parameters were positively correlated with MVD (P<0.05).The AT, TTP respectively showed a negative correlation with MVD ( P<0.05) . [ Conclusion] CEUS quantitative parameters of liver cancer tissue have high correlation with MVD.It can reflect the microvessel structure change of the liver cancer tissue and help to judge the curative effect and prognosis of HIFU for liver cancer.

Whole cell patch-clamp technique was used to record the changes of persistent sodium current (I(Na.P)) and the effect of administered agents in ventricular myocytes of guinea pig to investigate the essence of I(Na.P) and mechanism of increased I(Na.P) of ventricular myocytes during hypoxia. The results showed: (1) Pro-NO L-arginine(L-Arg) and donor sodium nitroprusside (SNP) increased I(Na.P) in a concentration-dependent manner in normoxia. (2) I(Na.P) increased gradually with the prolongation of hypoxia time. After 15 min of hypoxia, administration of N(G)-nitro-L-arginine methyl ester (L-NAME), a NO synthase inhibitor, could not significantly recover the increased I(Na.P) [(1.344+/-0.320) vs (1.301+/-0.317) pA/pF, P>0.05, n=5]; (3) During hypoxia the perfusion solution with L-NAME decreased the increased I(Na.P), and the difference was significant compared with pure hypoxia [(0.914+/-0.263), n=5 vs (1.344+/-0.320) pA/pF, P<0.05, n=6], whereas the amplitude of I(Na.P) was still larger than that in normoxia [(0.914+/-0.263) vs (0.497+/-0.149) pA/pF, P<0.05, n=5]; (4) Reducing agent dithiothreitiol (DTT) not only recovered the increased I(Na.P) by L-Arg and administered SNP after hypoxia [(1.449+/-0.522) vs (0.414+/-0.067) pA/pF, P<0.01, n=6, and (1.786+/-0.636) vs (0.436+/-0.141) pA/pF, P<0.01, n=5, respectively], but also decreased the I(Na.P) in normoxia [(0.442+/-0.056) vs (0.396+/-0.057) pA/pF, P<0.01, n=6]. Our results suggest that hypoxia increases I(Na.P) of ventricular myocytes, which is induced by raised NO oxidating sodium channel protein in myocardial membrane during hypoxia. The activity of I(Na.P) in normoxia is related to the oxidation state of the channel protein.
Animals ; Cell Hypoxia ; physiology ; Cell Separation ; Female ; Guinea Pigs ; Heart Ventricles ; Male ; Myocardium ; cytology ; Myocytes, Cardiac ; metabolism ; physiology ; Nitric Oxide ; pharmacology ; Nitroprusside ; pharmacology ; Patch-Clamp Techniques ; Sodium Channels ; physiology

AIMTo investigate the effect of hypoxia/early reoxygenation on persistent sodium current (I(Na.P)) in single ventricular myocytes of guinea pig and discuss its role and significance during this pathological condition.

METHODSThe whole cell patch clamp technology was used to record this current and study its change under the condition of hypoxia/reoxygenation model.

RESULTS(1) With 0.5 Hz, 1 Hz and 2 Hz pulse frequency, the current density gap between the first and the eighth pulse of I(Na.P) was (0.021 +/- 0.014) pA/ pF, (0.097 +/- 0.014) pA/pF and (0.133 +/- 0.024) pA/pF (P < 0.01) respectively. (2) Depolarization with membrane holding potential of -150 - -80 mV respectively, I(Na.P) density attenuated gradually. (3) The amplitude of I(Na.P) was increased consistently with the prolongation of hypoxia time during hypoxia. (4) I(Na.P) was (0.500 +/- 0.125) pA/pF, (1.294 +/- 0.321) pA/pF and (0.988 +/- 0.189) pA/pF (P < 0.01, vs normoxia, respectively) during normoxia, hypoxia after 15 min and reoxygenation after 5 min, respectively.

CONCLUSIONThese results indicate that I(Na.P) has great significance in arrhythmogenesis and calcium-overload, which causes the following postischemia and post hypoxia myocardial damage.

Animals ; Calcium ; metabolism ; Cell Hypoxia ; Guinea Pigs ; Heart Ventricles ; Membrane Potentials ; Myocytes, Cardiac ; metabolism ; physiology ; Oxygen ; metabolism ; Patch-Clamp Techniques ; Sodium ; metabolism ; Sodium Channels ; metabolism

In this study, a novel resequencing pathogen microarray (RPM)-based multi-pathogen detection assay was developed to simultaneously detect 14 rotaviruses, 7 caliciviruses, 8 astroviruses, 28 enteroviruses, and 16 rare diarrhea viruses in patients with diarrhea syndrome. The specificity of the assay was examined using confirmed virus-positive specimens, and the sensitivity was evaluated by serial ten-fold dilutions of in vitro transcribed RNA. RPM assay could detect and differentiate virus types/subtypes at 20-2000 copies/microL. The detection threshold of RPM was determined by adjusting the reference concentration, and the detection steps were optimized to type Enterovirus. The nucleic acids of 10 stool samples from patients with unexplained diarrhea were screened, and 6 of them showed positive results. The RPM results were further verified by singleplex PCR followed by sequencing, and no difference was found between the two assays. In conclusion, we have established a high-throughput RPM assay with high specificity and sensitivity, which demonstrates a great potential for the identification of pathogens in patients with unexplained diarrhea and the management of emerging epidemic.
DNA Primers ; genetics ; Diarrhea ; virology ; Feces ; virology ; High-Throughput Screening Assays ; methods ; Humans ; Oligonucleotide Array Sequence Analysis ; methods ; Sensitivity and Specificity ; Viruses ; classification ; genetics ; isolation & purification

Whole-cell and cell-attached patch-clamp techniques were used to record the changes of persistent sodium current (I(Na.P)) in ventricular myocytes of guinea pig to investigate the effect of low extracellular pH on I(Na.P) and its mechanism. The results showed that low extracellular pH (7.0, 6.8 and 6.5) obviously increased the amplitude of whole-cell I(Na.P) in a [H(+)] concentration-dependent manner. Under the condition of extracellular pH 6.5, I(Na.P) was markedly augmented from control (pH 7.4) value of (0.347+/-0.067) pA/pF to (0.817+/- 0.137) pA/pF (P<0.01, n=6), whereas the reducing agent dithiothreitiol (DTT, 1 mmol/L) reversed the increased IN(Na.P) from (0.817+/-0.137) pA/pF to (0.233+/-0.078) pA/pF (P<0.01 vs pH 6.5, n=6). Decreasing extracellular pH to 6.5 also increased the persistent sodium channel activity in cell-attached patches. The mean open probability and mean open time were increased from control value of 0.021+/-0.007 and (0.899+/-0.074) ms to 0.205+/-0.023 and (1.593+/-0.158) ms, respectively (both P<0.01, n=6), and such enhancement was reversed by application of 1 mmol/L DTT [to 0.019+/-0.005 and (0.868+/-0.190) ms, both P<0.01 vs pH 6.5, n=6]. Furthermore, protein kinase C (PKC) inhibitor bisindolylmaleimide (BIM, 5 micromol/L) reduced the enhanced mean open probability and mean open time at pH 6.5 from 0.214+/-0.024 and (1.634+/-0.137) ms to 0.025+/-0.006 and (0.914+/-0.070) ms, respectively (both P<0.01 vs pH 6.5, n=6). The results demonstrate that low extracellular pH markedly increases I(Na.P) in guinea pig ventricular myocytes, in which activation of PKC may be involved.
Animals ; Culture Media ; chemistry ; Extracellular Space ; chemistry ; Female ; Guinea Pigs ; Heart Ventricles ; cytology ; Hydrogen-Ion Concentration ; Male ; Membrane Potentials ; physiology ; Myocytes, Cardiac ; cytology ; physiology ; Patch-Clamp Techniques ; Sodium ; metabolism ; Sodium Channels ; physiology

In this paper, membrane current properties of the fully-grown oocytes from toad, Bufo bufo gargarizans, were studied by using two-microelectrode voltage clamp technique. Axion of adult female toad was destroyed, and then ovarian lobes containing oocytes in stage I to VI were removed and incubated in Ca(2+)-free ND96 solution with collagenase (1.5 mg/ml) for 1 h. Subsequently, the oocytes were washed in Ca(2+)-free ND96 solution for 10 min to completely remove the follicular layer. For the experiments only the oocytes in stage V and VI were selected and used during 1 to 5 d. The membrane was depolarized from a holding potential of -80 mV to +60 mV in 10 mV step. It was found that a sustained outward current was elicited by depolarization. Potassium channel blockers (tetraethylammonium chloride, TEA, 10 mmol/L and 4-aminopyridine, 4-AP, 10 mmol/L) reduced the outward current to (23.4+/-0.72)% of the maximum. However, further addition of chloride channel blocker (5-nitro-2, 3-phenypropylamino benzoate, NPPB, 30 micromol/L) could almost completely block the outward current to (2.1+/-0.08)% of the maximum. In the presence of TEA and 4-AP, removal of extracellular Ca(2+) or adding verapamil (40 micromol/L), could also reduce the outward current to (2.2+/-0.04) % and (3.1+/-0.15) % of the maximum, respectively. It is concluded that calcium-dependent chloride channels exist in plasma membrane of Bufo bufo gargarizans oocytes, besides potassium channels.
4-Aminopyridine ; toxicity ; Animals ; Bufo bufo ; Calcium ; metabolism ; Cell Membrane ; metabolism ; Chloride Channels ; drug effects ; physiology ; Female ; Nitrobenzoates ; pharmacology ; Oocytes ; metabolism ; Tetraethylammonium Compounds ; pharmacology ; Verapamil ; pharmacology

Objective To establish a method performance verification project and experimental method for the clinical chemiluminescence immunoassay.Methods Referring to CLSI evaluation protocols and pertinent literature,and by combining our actual works,we designed a verification procedure and experimental method.By Using these above,the precision,accuracy,analytical sensitivity,analytical measurement range,clinical reportable range and biotic interval of AFP on the Bayer Centaur 240 chemiluminescence immunoassay system were verificated.Results would be compared with the declaration of the manufacturer or desirable specifications derived from biologic variation.Results The results showed that the between-day inaccuracy on AFP levels at 77.4 ng/ml and 168.0 ng/ml was 5.70% and 4.84% respectively,these were consistent with manufacturer's inaccuracy claimed.The relative bias between the results measured for calibrator at four levels and target value was less 5.0%,and the relative bias between the results measured for EQA control sample at five levels and target value was-3.4% to 11.9%.Lower limit of detection was 1.04 ng/ml,lower slightly manufacturer's analytical sensitivity claimed.Biologic limit of detection was 2.65 ng/ml-3.53 ng/ml,functional sensitivity was 3.53 ng/ml.Analytical measurement range was 3.53-912.00 ng/ml,within manufacturer's liner range claimed.Clinical reportable range was 3.53-182 400.00 ng/ml.Reference interval was 0.6-7.7 ng/ml,within manufacturer' s claimed.Conclusions The main performances of the detection system are accorded with the declaration of the manufacturer.The performance verification procedure and experimental method of our research ars simple and practical,which has important significations for building medical laboratory and laboratory accreditation, improving quality of the chemiluminescence immunoassay.

Objective To investigate the changes in the threshold of auditory brainstem response (ABR),[Ca2+]i and calmodulin(CaM)in cochlear nucleus of the newborn mice infected by murine cytomegalovirus(MCMV)in the brain.Methods Sixty-nine newborn mice were randomized into the model group and the control group.The model group(54 mice)was established by intracranial injection with MCMV viral suspension 20 μl,and the same volume of 0.9％ sodium chloride was injected in the control group(15 mice).After one month,the ABR was tested in a sound-electric screen environment and the threshold was recorded.Then intracellular free calcium [Ca2 +] i and the mRNA level of CaM in the cochlear nucleus were assayed by flow cytometry and RT-PCR.Results Compared to the control group [(64.0 ±1.3)dBSPL],the threshold of ABR in the model group [(84.5 ±2.7)dBSPL] was increased(F =2.789,P =0.000).Moreover,in the model group the intracellular free calcium [Ca2 +] i and the mRNA level of CaM in the cochlear nucleus were increased(F =1.290,P =0.000;F =4.252,P =0.023),the differences were statistically significant.Conclusions The intracranial injection of MCMV can lead to abnormal changes in the threshold of ABR in mice,and the change of [Ca2 +]i/CaM in cochlear nucleus may be the important pathological basis of sensorineural hearing loss induced by MCMV infection.