Study of The Y-STR Multiplex Microfluidic Chip Rapid Amplification System / 生物化学与生物物理进展

ObjectiveAt present, the matching reagents of commercially available rapid DNA instruments based on microfluidics chip technology are autosome short tandem repeat (STR) individual identification reagents. The non-recombining part of the human Y chromosome is widely used in forensic DNA analysis, particularly in cases where standard autosomal DNA profile is uninformative. Y-STR loci are useful markers to identify males and male lineages in forensic practice. In order to achieve rapid and fully integrated detection ofY-STR loci, this study constructed the RTyper Y27 microfluidic chip rapid detection system and validated the performance of this system. MethodsThe system was verified and evaluated by sensitivity, success rate, typing accuracy, peak height balance, sizing precision and accuracy, mock case sample tests, mixture detection ability, and inhibition tolerance. ResultsComplete Y-STR profiles can be obtained when the template amount of DNA standard 9948 was ≥8 ng, the number of blood cards was ≥3 pieces, and the number of oral swab scrapings was≥7 times. The success rate of fully integrated detection was 91.52%, and the concordance rates was 99.74% for 165 testing samples. The success rate of 115 blood spots in these samples was 90.43%, with a typing accuracy of 99.65%, the success rate of 50 buccal swabs was 94%, with a typing accuracy of 99.92%. There was no significant difference in typing accuracy between blood spots and buccal swab samples. The peak height ratio between different fluorescence channels was 89.81%. The standard deviation of allelic ladder for 10 runs was within 0.5 bp. The size differences between allele and corresponding allele in allelic ladder was within 0.5 bp. The maximum precision CV values within and between batches were 0.48% and 0.68%, respectively, which were lower than 15%. These data indicate that the system has good accuracy and precision. The system was capable of accurately typing oral swabs, blood cards, saliva cards, cigarette butts, blood swabs and seminal stains. Complete Y-STR profiles can be obtained and distinguish at the 1∶3 ratio of minor and major contributors in artificial male DNA mixtures. Complete Y-STR genotyping can be obtained under the interference of inhibitors, such as different concentrations of humic acid (50-400 mg/L), indigotin (20-100 nmol/L) and hemoglobin (100-500 μmol/L). ConclusionIn this study, the RTyper Y27 microfluidic chip rapid amplification system is combined with the Quick TargSeq 1.0 integrated system, and the Y-STR profile can be obtained in approximately 2 h. Through a series of verification experiments, the results show that the system has good repeatability, accuracy and stability, can meet the on-site Y-STR detection requirements, and can be used in forensic practice.

Myocardial perfusion evaluation post percutaneous transluminal septal myocardial ablation in patients with hypertrophic obstructive cardiomyopathy by ⁹⁹Tc(m) MIBI SPECT MPI / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the myocardial perfusion and function in patients with hypertrophic obstructive cardiomyopathy (HOCM) before and after percutaneous transluminal septal myocardial ablation (PTSMA).</p><p><b>METHODS</b>Sixty-eight patients with hypertrophic obstructive cardiomyopathy were included and (99)Tc(m)-MIBI SPECT MPI was applied before and at 1 week after PTSMA, six-month follow-up was finished in 11 patients. Semi quantity and QGS quantity perfusion and function assessment was performed in 17 LV segments.</p><p><b>RESULTS</b>Myocardial perfusion post-PTSMA was significantly reduced in 98% patients, especially in basal anterosepta, basal interseptal, mid-anteroseptal, mid-interseptal and apical septal segments compared with pre-PTSMA (all P < 0.05). Perfusion was significantly increased at 6 months follow-up than at 1 week post-PTSMA but still lower than pre-PTSMA (all P < 0.05). LVEF (evaluated by gated SPECT) was similar before and after the procedure (P > 0.05). Regional wall motion after PTSMA was lower than pre-PTSMA in basal anterior, basal anteroseptal, basal interseptal and basal inferior (P < 0.05). Regional wall thinkening was lower than pre-PTSMA in basal interseptal, mid-anteroseptal, mid-interseptal (P < 0.05).</p><p><b>CONCLUSIONS</b>(99)Tc(m) MIBI SPECT can be used to monitor myocardial perfusion post PTSMA in patients with HOCM.</p>

Feasibility of in vivo isotope labeled autologous mononuclear bone marrow cells monitoring post cardiac transplantation in a swine model of myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe in vivo stem cell distribution and viability after transplantation by noninvasive imaging of 18F-fluorodeoxyglucose (18F-FDG) labeled autologous mononuclear bone marrow cells.</p><p><b>METHODS</b>Myocardial infarction was established in 8 swine by ligating left anterior descending coronary artery after anesthesia. Bone marrow (20 ml) was drawn through ileum. After isolation, mononuclear bone marrow cells were labeled by radionuclide 18F-FDG and intramyocardially injected into infarction region. Whole body planar scan and myocardial tomography scan were performed immediately, 1 h, 2 h, and 3 h post stem cell injection. Viability and stability of radionuclide labeled stem cells were determined at 3 h post labeling in vitro.</p><p><b>RESULTS</b>The labeling efficiency was (67 +/- 14)%. Mean dose of radioactive in marrow cells was (32 +/- 7) MBq. Trypan blue staining showed in vitro viability was (95 +/- 3)% at 3 h post labeling. After intramyocardial injection, labeled mononuclear bone marrow cell retention rate in infarction region was (83 +/- 6)%, (49 +/- 8)%, (32 +/- 6)% and (24 +/- 5)% immediately, 1 h, 2 h, and 3 h post injection, respectively.</p><p><b>CONCLUSIONS</b>Distribution and viability of stem cell after cardiac transplantation could be effective monitored by 18F-FDG labeled autologous mononuclear bone marrow cell technique in acute stage in this model.</p>