HIV Infections ; prevention & control ; Humans

Objective To establish and verify a multiplex fluorescence quantitative PCR method for detection of CHO host cell residual DNA content and fragmentation degree, so as to provide a reliable method for safety detection of related vaccines.Methods Two sets of primers(Alu-L and Alu) and universal probe were designed for clone250 and clone49c, members of Alu sequence family of CHO cells. The UBI3 gene of capsicum was introduced as external standard gene, and corresponding primers and probe were designed. Multiplex reaction system of Alu sequence and external standard gene was established, and the residual DNA of CHO cells in samples was quantified by the multiplex fluorescence quantitative PCR. The linear range,limit of quantitation(LOQ), specificity, robustness, precision and accuracy of the method were verified. In addition, the DNA fragmentation degree of CHO cells was determined by comparing the △Ct [Ct(Alu-L)-Ct(Alu)] of the amplification curves of long and short primers of Alu sequences. Results The multiplex reaction standard curve had a good linear relationship in the range of 0. 001-0. 1 ng/μL, R~2≥ 0. 99. The addition of external standard gene had no effect on the detection ability for CHO target, and the LOQ was 0. 5 fg/μL. The DNA of human, E.coli, rats and mice had no effect on the detection, the primers targeting residual DNA of CHO cells had no specific amplification in the genomes of seven animal cell lines, and the fragmented DNA samples showed no effect on the detection results. The CVs of precision verification were all less than 15%, and the recoveries of simulated samples in normal saline and PBS containing 1% BSA were in the range of 70%-130%. The△Ct of Alu and Alu-L amplification curves increased with the degree of sample fragmentation, and the fitting curve R~2≥ 0. 99.Conclusion The multiplex fluorescence quantitative PCR detection method established in this study can rapidly and accurately quantify the residual DNA of CHO cells and determine the fragmentation degree of samples according to △Ct, which can be used for the safety detection of the related vaccines.

Liquichip technology utilizes different fluorescent coding microbead as carriers of bio-probes and flow cytometry as optical detection method,to accomplish bio-molecules reaction in suspension liquid system.This article introduces the application of liquidchip technology in the analysis of autoimmune disease,cytokine,contagious disease,endocrinopathy,neural disease,tumor marker detection and so on.With the advantages of high sensitivity,high speed,high flux,multi-analyte,high accuracy and excellent repeatability,liquichip technology has promising prospect to be widely used as advanced biomedical detection platform.

Objective There are many interferences such as power interference, electrode polarization interference, myoelectricity interference, baseline drift, apparatus buzz and so on in electrocardiosignal acquisition system. It is very difficult to effectively remove these interferences in the process of actual measurement. Methods Power harmonic interference, electrode polarization interference and myoelectricity interference were removed by low-pass filter. Baseline drift was removed by high-pass filter. Power basic frequency interference was removed by 50 Hz trap filter. Results These three design proposals had such advantages as good effect, rapid speed and easy realization. Conclusion They can be well applied in ECG monitor with embedded CPU and real time character. Besides, they can also be used in medical apparatus measuring other biological electric signals and industrial observation and control system.

Actual research on brain-computer interface system is analyzed.The basic structure and operational principle of this system are set forth.Methods of signal collection,feature extraction and selection classification of system signals are concluded.Latest analysis methods and existing defects of feature extraction and selection classification are introduced in detail.Problems existing in brain-computer interface system are also analyzed.Great advantages on feature extraction of wavelet transform & wavelet packet decomposition and wide prospects on selection classification of neural network are pointed out at last.

Nucleated red blood cells (nRBCs) are immature red blood cells, which are rarely in circulating blood in elder children, but often present in neonatal blood. The clinical significance in neonates is unclear. Numerous studies have shown that many kinds of acute and chronic stimuli can lead to an increase in the number of nRBCs in circulating blood. This article reviews various pathological processes related to the production and release of nRBCs, and emphasizes the effects of acute and chronic hypoxia and immune regulation on it.

At present clinic study and use of anti-tumour platinum drug are wide and active. The paper reviews progression of clinic study and use of anti-tumour platinum drug and expects its prospect.

Expansive type of hepatocellular carcinoma (HCC) is a subtype of HCC. Correlation between the preoperative sonography and postoperative pathology was studied in 35 cases of HCC. According to the classification of nakashima, 21 cases belonged to the expansive type whereas the other 14 cases the infiltrative type. Different from the infiltrative type. the expansive type of HCC had four specific sonographic appearances: hypoechoic ring, hypoechcic halo, pedunculated and small nodular echo which had different pathological bases. Expansive tyje of HCC was not so commonly seen as infiltative type but its rate of surgical resection was mu~h higher than that of infiltratine type (JP< 0. 01). Thus, it is the kind of HCC with significant clinical importance. Preoperative ultrasonographic diagnosis help to decide the way of treatment.

Objective To investigate the methods of preoperation diagnosis and treatment of primary gastric lymphoma of mucosa-associated lymphoid tissue(MALT).Methods To analyze retrospectively the diagnosis and treatment of 54 cases of MALT lymphoma diagnosed surgically and pathologically.Results The most common symptoms were stomachache or discomfort.Of the patients with MALT lymphoma,85.2%(46/54)cases were diagnosed by preoperation gastroscopy with biopsy.Helicobacter pylori was found in 48 cases(88.9%).The overall resection rate for MALT lymphoma was 87%(47/54).The 5-year and 10-year survival were 77.1% and 72.9%,respectively.Conclusions It is obvious that MALT lymphoma is associated with Helicobacter pylori.Since no specific symptoms in gastric MALT lymphoma,the preoperative diagnosis is relied upon the application of gastrointestinal image,gastroscopy and repeated biopsy.The use of curative resection with the post-operative chemotherapy and/or radiotherapy to treat MALT lymphoma is reasonable.

Aim To study whether or not the green tea catechins(EGCG)has physiological benefits and the underling protective mechanism.Methods The subunit protein levels of ?4、?7 of nAChR were detected by BCA protein assay,Dot Blot assay and MTT assay.Results The results showed that the green tea catechins can significantly reduce the subunit protein levels of nAChR and decrease the cell activity induced by A?1-40.Conclusions EGCG can provide neuroprotection in vitro by up-regulating nAChR sununit levels and inhibiting the neurotoxin of A?1-40.