Intrauterine Treatment of Monochorionic Triamniotic Triplet Pregnancy with Twin Reverse Arterial Perfusion Sequence

To editor:This study reports a pregnant woman who was naturally conceived with monochorionic triamniotic(MCTA)combined with twin reversed arterial perfusion(TRAP).An ultrasound revealed that one of the fetuses had a cardiac malformation,and a connection between the umbilical arteries was suspected.To reduce the acardiac fetus,radiofrequency ablation was performed at 17+3 weeks of pregnancy.At 36+4 weeks,two healthy infants were delivered via elective cesarean section.Postoperative examination revealed a direct connection between the umbilical arteries,with the placental perfusion acting as a direct pump.It is essential to identify the intrauterine status of the blood-supplying infant and vascular connections in order to achieve successful outcomes in pregnancies with complications,such as edema and heart failure.The studies involving human participants were reviewed and approved by Human Research Ethics Committee of Tianjin Central Hospital of Obstetrics and Gynecology.The patient provided her written informed consent to participate in this study.

Syphilis testing algorithms:A review

The methods and strategies used to screen for syp-hilis and to confirm initially reactive results can vary significantly across clinical laboratories. While the performance characteristics of these different appro-aches have been evaluated by multiple studies, there is not, as of yet, a single, universally recommendedalgorithm for syphilis testing. To clarify the currently available options for syphilis testing, this update will summarize the clinical challenges to diagnosis, review the specific performance characteristics of treponemal and non-treponemal tests, and fnally, summarize select studies published over the past decade which have evaluated these approaches. Specifcally, this review will discuss the traditional and reverse sequence syphilis screening algorithms commonly used in the United States, alongside a discussion of the European Centre for Disease Prevention and Control syphilis algorithm. Ultimately, in the United States, the decision of which algorithm to use is largely dependent on laboratory resources, the local incidence of syphilis and patient demographics. Key words： Syphilis; Treponemal infection; Immuno-assay; Reverse sequence screening; Rapid plasma regain; Treponema pallidum particle agglutination test; Automation; Algorithm; Primary infection; Late latent infection

Increment of hFIX expression with endogenous intron 1 in vitro

This paper probes into the feasibility of increasing expression level of hFIX gene with endogenous nitron 1 sequence. hFIX minigene was obtained with middle sequence truncated nitron 1 inserted into the relative site of hFIX cDNA, and plasmid vector pKG5i’IX, retroviral vector GINaCi’IX were constructed. These vectors were transduced into target cells of PA317, C2C12, primary rabbit skin fibroblasts (RSF) and primary human skin fibroblasts (HSF). The expression level of mixed colonies are PA317/pKG5i’IX, 151 "g/106 cells/24h; PA317/GINaCi’IX, 308ng/106 cells/24 h; C2C12/G1 NaCi’IX, 186 ng/106 cells/24 h; RSF/GINaCi’IX, 1929 ng/106 cells/24 h; HSF/GlNaCi’IX, 1646 ng/106 cells/ 24 h. These results indicated that hFIX minigene with nitron 1 is able to increase the expression level to about 3 times of that of hFIX cDNA. Meanwhile, in order to study the application of hFIX minigene in the retroviral-mediated gene transfer system and refrain from nitron splicing during viral production, a retroviral vector GlNaCi’IXR with reversely inserted hFIX minigene expression cassette was constructed. The expression level of reverse constructor in PA317 cells was 390 ng/106 cells/24 h with 79% of bioactivity. PCR detection of HT/GlNaCi’IXR cells infected with PA317/ClNaCi’IXR supernatant confirmed the existence of nitron 1 sequence. These results suggested that expression vector with forward-inserted intronl-carrying hFIX expression cassette can be used in directed gene Human factor IX expression with nitron transfer, but when using the retroviral-mediated gene transfer system, reversely-inserted intronl-carrying hFIX expression cassette should be considered.

The Umbilical Cord and Complications of Twin Gestations

The rate of twin pregnancies has increased over the last decades, largely because of the ongoing development of assisted reproductive technology and increased maternal age at childbearing. Twins have a higher risk of adverse outcomes during pregnancy and the perinatal period. The prevalence of umbilical cord abnormalities is higher for twin pregnancies compared with singleton pregnancies. Some of these abnormalities are nonspecific to twinning and can also be found in singleton gestations (such as velamentous cord insertion, vasa previa, and single umbilical artery). Other abnormalities are associated with monochorionic twins, such as umbilical cord entanglement, and umbilical proximate cord insertion. Most of these abnormalities can be detected by ultrasound evaluation. The early and accurate ultrasound diagnosis of chorionicity, amnionicity, and placental and umbilical cord characteristics is crucial if we are to predict the risk of complications and to determine the best management for twin pregnancies. Histopathological examination of the placenta and umbilical cord after delivery can help to confirm prenatal diagnosis and to provide a better understanding of the physiopathology of their abnormalities. The aim of this review was to emphasize the role that the umbilical cord plays in twin complications and to describe the management of these high-risk pregnancies.