OBJECTIVETo express antibacterial peptide thanatin in the prokaryotic expression system and test its antibacterial activity.

METHODSThe DNA sequence coding for the 21 peptides of thanatin was synthesized using the preferred genetic codes of E. coli, cloned into pTYB11 plasmid, and transformed into E.coli ER2566. The expression of thanatin fused with intein was induced by IPTG in E.coli, and intein-thanatin specifically bound to the column through intein tag was cleaved overnight at 4 degrees celsius; in DTT/cysteine buffer.

RESULTSThe cleaved thanatin was eluted with a protein concentration of 245 microg/ml in the first 4 ml. The purified thanatin had showed strong antibacterial activities against G- bacteria such as Shigella flexneri, Klebsiella pneumoniae, Shigella snnei, Escherichia coli O157, toxin producing Escherichia coli, Pseudomonas aeruginosa, and fungi such as Candida albicans, with especial potency in killing drug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, and extended-spectrum beta-lactamases (ESBL)-producing E.coli. Eighty strains of drug-resistant (ESBL-producing) and 30 strains of sensitive E. coli were used for anti-bacterial assay, and no significant differences in the antibacterial activity of thanatin were found between the sensitive and drug-resistant E. coli (P>0.05).

CONCLUSIONThe recombinant thanatin obtained shows strong antibacterial activity against drug-resistant and sensitive bacteria, and can be a potential substitute for routine antibiotics in the treatment of G- bacterial infections.

Anti-Bacterial Agents ; metabolism ; pharmacology ; Antimicrobial Cationic Peptides ; biosynthesis ; genetics ; pharmacology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology

Adolescent ; Antibodies, Viral ; blood ; China ; epidemiology ; Female ; Humans ; Influenza A virus ; immunology ; Male ; Seroepidemiologic Studies ; Students, Medical ; Vietnam ; epidemiology ; Young Adult

Coronary Vessel Anomalies ; diagnosis ; Electrocardiography ; Humans ; Infant ; Pulmonary Artery ; abnormalities

Objective To investigate the brain mechanisms of aging of the visual attention. Methods Through the precue-target visual search paradigm using the event-related potentials technique,16 young and 16 elderly subjects participated the electrophysiological experiment.The background was comprised of three homocentric black circles and eight English capital letters consisted of each circle.The letter “T” was designed as the target stimulus.T was a target only when it located the circle clued to the same size of the precue.For example,when the cue was the “large”,“T” may appear within 3 circles.When the cue was the “median”,“T” may appear within either the median or small circles.When the cue was small,the target “T” may appear only within the small circle. Results The reaction time of the two groups of subjects became quick with the reduction of the cue scale,while the amplitudes of P1 and N1 components of event-related potentials increased with the decrease of the cue scale.Old subjects showed longer response time than did young subjects,and the posterior P1 component was enhanced significantly and N1 component was inhibited obviously.The P2 component was manifested as significantly inhibitory effect not only in the amplitude but also in the abnormal and unstable waveform.Conclusions The cognitive function of elderly subjects declines in the research of target stimuli,which suggests that the age-related changes could lead to deficit in the posterior area of the brain to visual spatial attention (involuntary attention).

Hypothalamic-pituitary-adrenal(HPA)axis-related factors in patients with type 2 diabetes were studied according to different levels of HbA1C.It showed that HPA axis was normal in HbA1C≤ 7% group[ACTH (18.03±8.39)ng/L,blood cortisol(49.22±8.68)μg/L],hyperactive in 7%11% group with weak feedback regulation[ACTH(26.08±15.41)ng/L,blood cortisol(55.64±24.27)μg/L].These results suggest that HPA axis-related factors in type 2 diabetic patients are different with different grades of glucose metabolic turbulence.

In order to study the influence of trichosanthin (TCS) on apoptosis and growth inhibition of human NB4 cells in vitro, the expression of annexin V and the change of DeltaPsim of NB4 cells induced by TCS was analyzed by FACS, and MTT assay was adopted to measure the growth inhibition ratio of NB4 cells treated with TCS. Apoptosis was assayed by agarose gel electrophoresis. The results showed the higher concentration of TCS and the longer the acting time, the stronger growth inhibition of NB4 cells. The expression of annexin V was positive, and the positive ratio was greatly enhanced with prolongation of acting time. DeltaPsim reduced gradually while the apoptosis cells increasing. DNA agarose gel electrophoresis showed a gradient, which confirmed that TCS could induce NB4 cells apoptosis. In conclusion, taken together, data show that TCS can inhibit NB4 growth in vitro, and induce apoptosis. Experiment provides an important evidence for application of TCS in clinical treatment of acute promyelocytic leukemia.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; DNA Fragmentation ; drug effects ; Dose-Response Relationship, Drug ; Flow Cytometry ; Humans ; Trichosanthin ; pharmacology

OBJECTIVETo study the rabies molecular biology features in animals between high incidence area of rabies and no rabies cases area in Hunan.

METHODSdetect saliva of dogs and brains of dogs and cats by direct immunofluorescence assay, review positive samples by RT-PCR, sequencing extract RNA virus for genetic analysis.

RESULTS12 were detected rabies virus antigen and positive nucleoside acid in 82 dogs from Wugang city also 1 in 17 from Dongkou county; the positive rate: Wugang 14.63 percent, Dongkou 5.88 percent. No rabies virus was detected in 67 samples of dog brains from Fenghuang County. Also none in 28 samples of cat brains. Amplificating N gene of rabies virus from positive samples of dog brain's tissue (No Wg13, Dk13) by RT-PCR, it shows that homology of nucleoside acid between two strain of virus is 99.4 percent; also 99.1 percent of amino acid. The homology of nucleoside acid (amonio acid) among Wg13 stain and Chinese strain CTN and aG strain is 89.4 percent (98.2 percent) and 86.1 percent (95.1 percent); The homology of nucleoside acid (amonio acid) among Dk13 stain Chinese strain CTN and aG strain is 89.1 percent (98.0 percent), 86.1 percent (94.9 percent).Compare with isolated rabies virus from abroad, the homology between two strains and Indonesia is 92.8 percent and 93.2 percent, the most similar of them. The strains isolated from other countries including Japan, Sri Lanka and India are relatively lower; The sequence of gene Wg13 and Dk13 were taken replacement of amino acid.

CONCLUSIONTwo strains are belong to type I rabies virus, comparing its N gene with current using vaccine strains, both are in same group, and homology are relatively higher.

Animals ; Cats ; Dogs ; Genes, Viral ; Phylogeny ; Rabies virus ; classification ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Substantial evidence strongly implies that sensory gating P50 (also called P50 auditory evoked potential, P50) and dopaminergic neurotransmitters are related. In animal experiment, P50 can be recorded in an awake and quiet state with freedom of movement. Until now there is lack of animal experimental data on the supportive effect of estrogen on function of dopaminergic neurons in substantia nigra (SN) in physiological state. In the present study, female Sprague-Dawley (SD) rats were used as subjects. The animals were divided randomly into four groups: (1) control group (normal animals); (2) Parkinson's disease (PD) model group: the right SN was lesioned with 6-hydroxydopamine (6-OHDA); (3) PD model with bilateral ovariectomized group (OVX-PD): bilateral ovariectomy was performed before administration with 6-OHDA; (4) estrogen + PD model with bilateral ovariectomized group (OVX-E(2)-PD): physiological dose of estrogen was given to the bilateral ovariectomy animals before administration with 6-OHDA. P50 induced by two brief acoustic stimuli were recorded in the right SN and the number of TH(+) dopaminergic neurons in the SN stained by immunohistochemistry was calculated after the determination of P50. The results showed that in the PD model group, the testing/conditioning (T/C) ratio of P50 decreased by 40.60% and the number of TH(+) cells in the right SN decreased by 64.74% as compared with that in the control group (P<0.01); In the OVX-PD group, the T/C ratio of P50 decreased by 45.88% and the number of TH(+) cells was reduced by 57.26% as compared with that in the PD group (P<0.01). Administration with 6-OHDA into the SN pars compacta of ovariectomized rats caused more decrease in the number of TH(+) cells as well as more damage to the function of sensory gating in SN. While in OVX-E(2)-PD group, intramuscular injection with estrogen at physiological dose 3 d before 6-OHDA administration decreased the degree of damage to the SN functionally and morphologically, and its degree of injury corresponded to PD group. These results indicate that the mechanism of protection of dopaminergic neurons in the SN provided by physiological level of estrogen is by promoting the resistibility of the neurons to harmful stimulation. If the gonads are resected resulting in a lack of estrogen, the degree of injury to the function and morphology of dopaminergic neurons in SN induced by 6-OHDA increases. Replacement of estrogen at physiological level on time is necessary. Sensory gating P50 in SN may reflect dynamically the protection of estrogen against dopaminergic neurons depletion in vivo.
Animals ; Disease Models, Animal ; Dopaminergic Neurons ; drug effects ; Estrogens ; pharmacology ; Evoked Potentials, Auditory ; Female ; Neuroprotective Agents ; pharmacology ; Ovariectomy ; Oxidopamine ; adverse effects ; Parkinson Disease ; physiopathology ; Parkinson Disease, Secondary ; Rats ; Rats, Sprague-Dawley ; Substantia Nigra ; cytology ; drug effects

Embryo technology, including super-ovulation, embryo transfer and embryo nucleus transfer, was a well-developed technology in 20th century. It has been widely used in animal science and veterinary and boomed livestock industry in China. Chinese livestock producer could gain high grade breeds in short time through embryo technology by the reason that embryo technology could make outstanding gene spread out in herd. With the help of embryo technology, rare animals could have a chance to extend their progeny in fast changing world. In this article, we briefly introduced the process of embryo transfer and application of embryo technology in China.

BACKGROUND: The balloon dilatation technique plays an important role in the correction of kyphosis. A balloon catheter can enlarge the spinal cavity in kyphoplasty followed by injection of bone cement under low pressure to lay a foundation for the stability of the spine. OBJECTIVE: To explore the feasibility of balloon dilation with injectable calcium sulfate cement for tibial plateau fractures and to analyze its clinical effect. METHODS: Twenty-four upper tibia specimens of the adults were taken to make the Schatzker Ⅲ collapsed fracture model of the tibial plateau. Then, these specimens were randomized into three groups: the standard group was subjected to poking reduction with autologus bone grafting and screw internal fixation, the bone cement group was inflated with balloon dilatation followed by calcium sulfate cement injection, and the combined group was treated with fixation with cancellous bone screws and balloon dilatation followed by injection of calcium sulfate cement. The general situation of reduction and fixation was observed and the reduction effect was measured. RESULTS AND CONCLUSION: (1) Fixation effect in the model: All three models were well reset, and the average displacement of the standard group, the simple bone cement group and the bone cement screw group was (-0.22±0.62), (-0.23±0.67), and (-0.20±0.69) mm, respectively. There was no significant difference in the displacement between the three groups (P ＞ 0.05). (2) Clinical application: One case of Schatzker type Ⅱ fracture of the left tibial plateau was treated with cancellous bone screw fixation and balloon dilatation followed by injection of calcium sulfate cement. X-ray results showed calcium sulfate cement was visible at 3 postoperative days. At 30 postoperative days, the patient presented with good joint range of motion, and the calcium sulfate was partially absorbed on the X-ray film. At 60 postoperative days, the patient appeared to have no joint extension disorder, and fracture healing and absorption of calcium sulfate as shown by X-rays. To conclude, the balloon dilation with injectable calcium sulfate cement for the treatment of tibial plateau fracture is feasible and has clinical value.