Objective To investigate the clinical significance of fetal tricuspid regurgitation (TR) in the screening of chromosomal abnormalities at the first-trimester. Methods Screening for chromosomal abnormalities was carried out in 1 262 fetuses at 11+0 to 13+6 weeks. Ultrosound was performed to measure crown rump length and nuchal translucency (NT) thickness, and to acquire tricuspid waveform. All the neonates were followed up for 6 months after birth. Results Among the 1 262 fetuses, 68 were found to have TR. TR was present in 54 (4.4%) of the 1 239 chromosomally normal fetuses, and in 14 (61%) of the 23 with chromosomal abnormalities. Cardiac malformations were detectable in 28 fetuses. The prevalence of TR was 64%in those with cardiac malformations and 1.5%in those without cardiac malformations. Conclusions Tricuspid regurgitation is an effective predictor for the detection of fetal chromosomal abnormalities at the first trimester.

Purpose To probe into the value of M-mode echocardiography and spectral Doppler echocardiography in diagnosing fetal atrial premature beats.Materials and Methods Echocardiography examinations were given to the seventy-three fetuses around 16-40 gestational weeks which were found suffering from fetal arrhythmia in the clinical examinations by using M-mode echocardiography and spectral Doppler. Thirty-two of them were screened out with fetal atrial premature beats, and their ultrasonic cardiograms were analyzed. The follow-up visits were later conducted.Results Among the thirty-two cases with fetal atrial premature beats, fourteen were attacked frequently, and the other eighteen were attacked accidentally. Two cases were documented with muscular ventricular septal defect. Apart from two missing cases, the rest thirty cases were found to be recovered from arrhythmia before or after birth in the follow-up visits. The disappearance rate of atrialpremature beats in the fetuses attacked frequently by the disease before birth was clearly lower than that in those attacked accidentally (P<0.05). Muscular ventricular septal defect in the two cases were found closed after birth. Conclusion M-mode echocardiography and spectral Doppler echocardiography, as non-invasive imagining techniques to take antenatal examination of fetal arrhythmia, have advantages such as reliable, direct, convenient and can be used repetitively, therefore can provide important information for clinical treatment and prognosis.

Objective To establish a new method for rapid detection of β-thalassemia by investigating six clinical common mutation types.Methods Fifty cases of clinical wild-type samples and 42 cases ofβ-thalassemia samples were collected, and β-globin gene was amplified by PCR.Uniform ligation probe ( ULP) specific probes were designed for hybridization reaction to increase the reaction specificity and real-time PCR was performed to increase the sensitivity.After that, PCR products were verified by agarose electrophoresis.After examining the specificity and sensitivity, Kappa test between LDR-ULP method and reverse dot blot( RDB) method was conducted.Results Hybridization efficiency was improved 2.53 times by LDR-ULP hybridization.Each mutant type showed a significant amplification curve, whereas the wild-type had no significant curve within 40 cycles.The limit of determination of this method was 5 pg.The results of 92 cases of peripheral blood samples detected by the method of LDR-ULP and RDB were completely consistent.Conclusion In this study, a simple, inexpensive, rapid new method to detect β-thalassemia were established.

Objective To establish a homothermal and fast detecting method on pathogenic bacteria by combining recombinase-aid amplification (RAA) with molecular beacon.Methods The establishment of the methodology.Staphylococcus aureus specific primers were designed from the relative region of the staphylococcal protein A (SPA).Asymmetry amplification was optimized by adjusting the primer concentration ratios.The results of amplification and hybridization were visualized and analyzed by agarose gel electrophoresis and fluorescence detection.The sensitivity was identified by detecting dilute positive plasmids.And the specificity was determined using RAA method by detecting 72 pathogenic bacteria,including Staphylococcus aureus and other Staphylococcus spp.from the Department of Clinical Laboratory of Daping Hospital in December 2016.Besides,the Kappa analysis and the clinical diagnosis efficiency were investigated by analyzing 39 extra strains in the laboratory in December 2016.Results When the concentration ratio of restrictive and non-restrictive primer was 1:20,the yield efficiency of single-stranded DNA (ssDNA) reached the peak.And as for the hybridization efficiency,the asymmetry amplification was higher than symmetry amplification.Twenty copies/μl was proposed as the limits of detection by testing dilute plasmids.And the RAA hybridization method could distinguish Staphylococcus aureus with other Staphylococcus spp.Comparing with traditional detection methods with a Kappa index of 0.860,this method shows a good consistency.By analyzing the 111 bacteria,the sensitivity of the method is 92.5％ (37/40),the specificity is 97.2％ (69/71),the positive predictive value is 94.9％ (37/39),the negative predictive value is 95.8％ (69/72),the positive likelihood radio is 33.04,the negative likelihood radio is 0.077,the Youden index is 0.897 and the Kappa index is 0.902.Conclusion Through the combination of asymmetry recombinase-aid amplification optimization and molecular beacon probe,a new method of detecting bacteria DNA with RAA hybridization technique is established,providing the foundation for its clinical application.

Objective To explore the value of prenatal echocardiography in diagnosis of fetal ventricular septal defect (VSD).Methods Prenatal echocardiography was performed on 3 826 fetuses,and the results were compared with those of postnatal echocardiography or autopsy findings.The diagnostic accuracy,misdiagnosis rate and missed diagnosis rate of prenatal echocardiography for VSD were calculated.Results Among 3 826 fetuses,VSD was found in 61 fetuses (61/3 826,1.59％) with prenatal echocardiography,including simple VSD in 36 fetuses (36/3 826,0.94％) and VSD complicated with other heart malformations in 25 fetuses (25/3 826,0.65 ％).According to the results of autopsy and postnatal echocardiography,the final diagnosis of VSD was found in 76 cases (76/3 826,1.99％),of which simple VSD was found in 51 cases (51/3 826,1.33 ％),VSD complicated with other heart malformations were found in 25 fetuses (25/3 826,0.65％).The diagnostic accuracy,missed diagnosis rate and misdiagnosis rate of simple VSD with prenatal echocardiography was 58.82％ (30/51),41.18％ (21/51) and 1.06‰ (4/3 775),respectively.The diagnostic accuracy,missed diagnosis rate and misdiagnosis rate of VSD complicated with other heart malformations with prenatal echocardiography was 96.00％ (24/25),4.00％ (1/25) and 0.26‰ (1/3 801),respectively.Conclusion Echocardiography has important clinical value in prenatal diagnosis of fetal VSD,which can provide important references for treatment plan and prognosis evaluation.