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Objective To explore the effectiveness of whole genome amplification technology in DNA typing of trace samples.Methods Simulated trace samples which contain 1～20 cells were prepared by micromanipulation.Whole genome amplification was added before conventional PCR-STR typing step,to compare the effectiveness of PEP and MDA in DNA typing of trace samples from four aspects i.e.allele imbalance,allele drop-out,locus drop-out and pseudo allele (which contains the stutter peak).Results Amplification efficiency of MDA was higher than PEP method,but allele drop-out and pseudo allele were more frequently detected.Correct DNA typing rate of PEP is higher than MDA method,however,advantaged amplification of small fiagments DNA is more obvious.Conclusion MDA method is not suitable for the current STR typing.When the absolute amount of trace samples is quite small,we couldconsider using the PEP method to enhancethe sample quantity to meet the requirement of repeat testing.At the same time it could encounterthe failure of the large DNA fragments.
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Objective To study the local anatomic structure of subclavian vein and have a good command of operating methods and skills on subclavian vein catheterization (SVC) so as to improve the success rate of puncture. Methods Retrospectively analyze the clinical data of 600 cases of hospitalized patients who have had SVC (male 410, female 190) in our hospital from March 2010 to March 2014. Results There were 582 cases (97%) of successful puncture,including 546 cases (91%) of one-time puncture success,38 cases (6. 3%) of repeated puncture or other types of puncture,and 16 cases (2. 7%) of failed puncture. Postoperative complications occurred in 22 patients (3. 7%),including 8 cases (1. 3%) of strayed into the artery,3 cases (0. 5%) of pneumothorax,5 cases (0. 8%) of catheter tip into the internal jugular vein,2 cases (0. 3%) of catheter related infection,2 cases (0. 3%) of catheter blockage,and 2 cases (0. 3%) of arrhythmia. Conclusion SVC is easy,safe and reliable,and it is of high success rate and less complications. Catheter retention time of SVC is longer. From the above,SVC is a good central venous puncture method which is worth of popularizing in clinical use.
RESUMO
Objective To establish a mini-pool nucleic acid testing (NAT) assay using multiplex RT-nested PCR for the detection of HIV RNA, and apply it in screening for acute HIV infection among MSM. Methods Frozen EDTA plasma samples collected between Oct. 2008 and Mar. 2009 from 3 HIV infectors during window-period, a total of 30 HIV chronically infected individuals and 97 healthy subjects were used to develop the NAT assay. Plasma samples from 10 cases were pooled into one tube and centrifuged at high speed for the collection of viruses. HIV RNA was extracted. Two pairs of primers were designed according to two conserved regions of HIV RNA ( HXB2 nt 5783-nt 6228 and nt 1235-nt 2012).Multiplex RT-PCR and nested PCR were performed. Individual NAT-reactive samples were confirmed by commercially available NAT assays. The sensitivity and performance efficacy were also evaluated. The assay was then applied to 1 005 plasma specimens from MSM with negative or uncertain HIV antibody test results.These were collected in the same period as the other samples. Results ( 1 ) Two fragments of HIV were amplified successfully with the low detection limit of 162 copies/ml plasma; (2) Results of the mini-pool HIV NAT validation with samples from 3 HIV infectors during window-period were consistent with the expected values; (3) All 30 plasma samples from MSM with positive HIV antibody, which were tested by multiplex RT nested PCR, were found to be HIV RNA positive; (4) One out of 1 005 plasma samples was found to be HIV RNA positive, for this case acute infection was followed-up and sero-conversion was found. Conclusion Mini-pool NAT has good sensitivity, and may be applied to screening HIV RNA among MSM during window-period.