Vagus Nerve Stimulation in the Treatment of Dravet Syndrome / 罕见病研究

Dravet syndrome is a epileptic syndrome characterized by drug-resistant epilepsy occuring at childhood. It is often accompanied by status epilepticus and cognitive and language impairment appearing gradually as the disease progresses. The effect of antiepileptic drugs and resection epilepsy surgery on Dravet syndrome is poor although neuromodulation surgery, especially vagus nerve stimulation, is an effective and feasible treatment for Dravet syndrome. In this article we reported a case of Dravet syndrome treated with vagus nerve stimulation, relevant literature was reviewed and summarized at the same time. A total of 141 cases of Dravet treated by vagus nerve stimulation were collected, and the overall effective rate was 53.9%.

Development and evaluation of a novel method for rapid screening of Pichia pastoris strains capable of efficiently expressing recombinant proteins / 生物工程学报

Pichia pastoris is one of the most widely used recombinant protein expression systems. In this study, a novel method for rapid screening of P. pastoris strains capable of efficiently expressing recombinant proteins was developed. Firstly, the ability to express recombinant proteins of the modified strain GS115-E in which a functional Sec63-EGFP (Enhanced green fluorescent protein) fusion protein replaced the endogenous endoplasmic reticulum transmembrane protein Sec63 was tested. Next, the plasmids carrying different copy numbers of phytase (phy) gene or xylanase (xyn) gene were transformed into GS115-E to obtain recombinant strains with different expression levels of phytase or xylanase, and the expression levels of EGFP and recombinant proteins in different strains were tested. Finally, a flow cytometer sorter was used to separate a mixture of cells with different phytase expression levels into sub-populations according to green fluorescence intensity. A good linear correlation was found between the fluorescence intensities of EGFP and the expression levels of the recombinant proteins in the recombinant strains (0.8<|R|<1). By using the flow cytometer, high-yielding P. pastoris cells were efficiently screened from a mixture of cells. The expression level of phytase of the selected high-fluorescence strains was 4.09 times higher than that of the low-fluorescence strains after 120 h of methanol induction. By detecting the EGFP fluorescence intensity instead of detecting the expression level and activity of the recombinant proteins in the recombinant strains, the method developed by the present study possesses the greatly improved performance of convenience and versatility in screening high-yielding P. pastoris strains. Combining the method with high-throughput screening instruments and technologies, such as flow cytometer and droplet microfluidics, the speed and throughput of this method will be further increased. This method will provide a simple and rapid approach for screening and obtaining P. pastoris with high abilities to express recombinant proteins.

Constitutive display of Candida antarctica lipase B on the cell surface of Aspergillus niger and regulation of its fermentation / 生物工程学报

Displaying Candida antarctica lipase B (CALB) on the cell surface of Aspergillus niger is effectively applied for the industries of food, cosmetics, pharmaceutical and so on. Displaying CALB using induced promoter of glucoamylase on the cell surface of A. niger SH-1 has some problems such as inhibiting its expression under high concentration of glucose, mycelium cleavage and decreasing enzyme activity in the later period of fermentation process. Displaying CALB manipulated by constitutive promoter from glyceraldehyde-3-phosphate dehydrogenase instead of glucoamylase on the cell surface of A. niger SH-1, called AN-GpdA, could solve the above problems effectively. Furthermore, it can not only use glucose, but also xylose as a sole carbon source. Enzyme activity of AN-GpdA using xylose for fermentation reached 1 100.28 U/g of dry cell. We also used lignocellulose such as the hydrolysate of bagasse for fermentation with good performance. The result would provide a novel strategy for the utilization of bagasse.

Preparation of superparamagnetic paclitaxel nanoparticles from modified chitosan and their cytotoxicity against malignant brain glioma / 生物医学工程学杂志

We synthesized the superparamagnetic paclitaxel nanoparticles from modified chitosan tangling around Fe3O4 ferrofluid and taxol, and observed the nanoparticles with transmission electronic microscopy (TEM). Then we evaluated the paramagnetism of the particles by vibration specimen magnetometer (VSM) and tested their cytotoxicity with flow cytometry (FCM). The prepared nanoparticle solution was black without any floccule or sediment and appeared transparent after diluted. The nanoparticles were spherical and dispersed in water with mean diameter of 15 nm under TEM and showed superparamagnetic character. FCM test showed the nanoparticles had significant toxic effects against malignant astrocytoma U251 cell lines, equal to taxol alone. These results showed that the superparamagnetic nanoparticle not only enhanced the solubility of paclitaxel in water, but also was superparamagnetic and cytotoxic, which make suitable tools for magnetic targeting chemotherapy of brain gliomas.

X-ray and Clinical Characteristics of the Adult Contagious Atypical Pneumonia / 实用放射学杂志

Objective To enhance the cognition about the adult contagious atypical pneumonia for an expectation of earlier diagnosis, prevention and treatment.Methods We analyzed and summarized X-ray lung and clinical characteristics of 34 patients with contagious atypical pneumonias who were admitted to our hospital from Feb to April. 2003.Results X-ray findings of lung were characterized by mostly involving unilateral and presenting ill defined cloud or patches-form opacities. These lesions progressed and varied rapidly. The clinical manifestations were characterized by the onset of fever (34/34), mostly associated with systemic and joint aching pains (29/34) and dry coughs (29/34). Leucocyte counts showed normal or lower than normal. Patient with a continuing high fever might tend to develop ARDS (2/34). All the 34 patients recovered after combined therapies (anti-inflammation, anti-virus and promoting immunity ) and were discharged from hospital. The average in-hospital days were (10.6?4.2) days. Conclusion X-ray examination is the main method for the early diagnosis and observing state-variation. The predominant clinical features of this disease are fever, dry cough, aching pain in extremities, unconspicuous pulmonary signs as well as hemogram not rising, a continuing high fever may lead to the tendency of ARDS.

Effect of X-ray on amino-acid transmitters in brain of epileptic rat / 解放军医学杂志

Objective To investigate the effective mechanism, time and rational dose of radiotherapy of epileptic rat. Methods To make rat model of epilepsy, and give 0, 24,12 or 6Gy X ray irradiation, and then detect the amino-acid contents in frontal lobe of those rats in 1 hour, 24 hours or 1 week after radiotherapy. Results Glu and GABA are the key amino-acids in radio effection. After 12Gy or 24Gy irradiation there were low Glu, high GABA and low Glu/GABA in frontal lobe of rat. After 1h, 24h and 1 week irradiation, the contents of GABA raised up while the ratio of Glu/GABA declined with a remarkable decline at 24h. Conclusions Radiotherapy to epileptic rat may set off a rapid and enduring change of GABA and Glu transmitters, and 12Gy may be the rational radio dose for epileptic rat.