Efficacy and initial clinical evaluation of optical genome mapping in the diagnosis of structural variations / 中华预防医学杂志

To investigate the efficacy and value of optical genome mapping (OGM) in detecting chromosomal structural variations. In a clinical study about high-precision analysis of genomic structural variation for complex genetic diseases, a retrospective study was performed on the cases with karyotyping at the department of Obstetrics and Gynecology, and Endocrinology of Peking Union Medical College Hospital from January to December 2021. Ten cases with abnormal karyotype was detected by OGM. Partial cases were verified by fluorescence in situ hybridization (FISH), SNP array or CNV-seq. Results of ten cases, nine were detected with abnormality by OGM, including unbalanced chromosomal rearrangements (n=3), translocation (n=5) and paracentric inversion (n=1), and the results were in concordance with other standard assays. However, one case with breakpoint and reconnected at centromere has not been detected. In conclusion, ten samples were comprehensively analyzed by karyotyping, FISH, SNP array or CNV-seq, and OGM, and results demonstrated that optical genome mapping as a new technology can not only detect unbalanced rearrangements such as copy number variants as well as balanced translocations and inversions, but more importantly, it can refine breakpoints and orientation of duplicated segments or insertions. So it can contribute to the diagnosis of genetic diseases and prevent birth defect. However, the current technology is not yet capable of detecting breakpoints of balanced structural variations lying within unmapped regions.

Metabolic Characteristics of Leucocyte-deplated and Suspended RBC Produced by Using Lipid Whole Blood During Routine Storage / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the differences of metabolic pathways of leucocyte-deplated RBCs prepared by using lipid whole blood and nomal blood during routine storage so as to provide some reference for clinical blood use.</p><p><b>METHODS</b>Twenty U whole blood from 20 donors, including 10 U lipid blood and 10 U normal whole blood, were selected for preparing leukodepleted red blood cells, red blood cells were taken from storage bags on day 0, 14 and 35, respectively. Metabolites in the red blood cells were analyzed, red blood cell metabolic extracts were detected by UPLC-MS/MS. The metabolite data of RBC from 2 groups were analyzed by SIMCA-P 13.0 software using OPLS-DA and by SPSS 19.0 using Mann-Whitney U test. Difference of metabolic pathways was described according to different metabolites.</p><p><b>RESULTS</b>The glucose, adenine, pyruvic acid, GSH, GSSG and niacinamide levels on day 0 in lipid RBCs were higher than those in the control group(P<0.05). The glucose, pyruvic acid and GSH levels on day 14 in lipid RBCs were lower than those in the control group (P<0.05), and the levels of adenine, GSSG and niacinamide were higher than that in the control group (P<0.05). The glucose level on day 0 was lower than that in the control group (P<0.05), and the levels of adenine and niacinamide were higher than those in the control group (P<0.05). but the pyruvic acid, GSH and GSSG levels were not significantly different between 2 groups (P>0.05).</p><p><b>CONCLUSION</b>Compared with the normal red blood cells, the energy metabolism pathway decreases in lipid red blood cells within the storage period and pentose phosphate pathway increases.</p>

Genetic counseling, prenatal screening and diagnosis of Down syndrome in the second trimester in women of advanced maternal age: a prospective study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The incidence of autosomal trisomy in livebirths is strongly dependent on maternal age. Special consideration is given to the provision of prenatal screening and cytogenetic testing to women of advanced maternal age (AMA). The aim of this study was to evaluate the effectiveness of second trimester prenatal screening and amniocentesis for Down syndrome (DS) and compare the trends of choice of screening and amniocentesis among AMA women.</p><p><b>METHODS</b>A total of 5404 AMA patients with natural singleton pregnancy were recruited for this prospective study from January 2008 to December 2010. The gestational weeks were from 15 weeks to 20(+6) weeks. The patients referred were grouped into a screening group (2107 cases) and an amniocentesis group (3297 cases) by their own decision. The prevalence of DS was compared between the two groups by chi-square test. Choice rates for each maternal age with trends were compared by regression analysis.</p><p><b>RESULTS</b>There were 18 cases of fetal DS detected in the screening group with a prevalence of 8.54‰ (18/2107). Twenty-five cases of fetal DS were diagnosed in the amniocentesis group with a prevalence of 7.58‰ (25/3297). No statistical difference was observed in the prevalence of DS between the screening and amniocentesis group (P = 0.928). The invasive testing rate for DS in the amniocentesis group was 5.54 times higher than that of the screening group (1/131.88 vs. 1/23.78). With the increase of the maternal age, the choice of amniocentesis increased while the choice of the screening showed an opposite trend. The choice of the AMA women between the screening and amniocentesis was significantly age relevant (P = 0.012).</p><p><b>CONCLUSIONS</b>The second trimester serum screening in combination with maternal age was more effective than maternal age alone to screen for DS. We suggest educating the patients by recommending AMA women be informed of both screening and amniocentesis options.</p>

Characterization of an iridovirus detected in rock bream (Oplegnathus fasciatus; Temminck and Schlegel) / 病毒学报

During the summer of 2009, mass mortality was observed in cage-cultured Rock Bream (Oplegnathus fasciatus; Temminck and Schlegel) in the Liaoning Province. Histopathogic studies of the affected fish showed enlarged basophilic cells in the kidney and spleen. These necrotic cells were stained purple using haematoxylin and eosin (HE). GF cell cultures showed advanced cytopathic effects after infection with virus supernatants from diseased fish homogenate. Transmission electron microscopy revealed hexagonal outlines virions in the cytoplasm of the spleen, kidney, liver, intestine cells. The viral particles consisted of a central nucleocapsid (100-110 nm) and envelope, and were 150-180 nm in diameter. These results suggested that the virus belonged to the Iridoviridae. Using polymerase chain reaction (PCR), approximately 570-bp fragments were amplified from the viral DNA in spleen, kidney, gill, intestine, heart and brain of diseased fish with the primers derived from red sea bream Iridovirus (RSIV). In addition, a specific fragment of 1 400 bp of the major capsid protein (MCP) gene of the Iridovirus was amplified by PCR. A phylogenetic tree was constructed to compare the corresponding genetic sequences in Megalocytivirus. The tree demonstrated that RSIV-LN09 virus existed in the same branch as the RSIV-U1 et al. Our present results indicated that RSIV was the causative agent.

Isolation and characterization of an iridovirus from sick giant salamander (Andrias davidianus) / 病毒学报

A virus was isolated from cultured sick giant salmander (Andrias davidianus ) in a farm, Shanxi Province, China. Skin ulceration and necrosis of the distal limbs are main clinical symptoms. Virus propagated and caused CPE at 10 degrees C to 30 degrees C in BF-2, CO, CHSE, FHM cells. The optimum condition of replication was in BF-2 cells at 25 degrees C. The virus was proved to be senstive to chloroform, heat, pH3 and pH10 treatment. Viral replication was inhibited by 5-Fluoro-2-deoxyuridine (FUDR). These results indicated that the virus possessed an envelope and DNA as the genome. Electron-microscopic observation of thin-section showed numerous hexagonal viral particles measuring 130 nm to 150 nm in diameter orderly arranged in a lattice form in cytoplasm of BF-2 cells. The particles showed typical iridovirus morphology. A 413 bp fragment was amplified from the viral main capsid protein gene by PCR. The fragments was sequenced and analysed. The results showed the isolate shared more than 96% nucleotide identity with some Ranaviruses. We suggested that this virus was named as Andrias davidianus iridovirus (ADIV) tentatively.

Comparison of characteristics of SVCV strains isolated in China and in Europe / 病毒学报

In the nationwide epidemiological investigation, SVCV-741 was for the first time isolated in Beijing region, China in 2003, and designated as SVCV Asian strain. In this paper, we compared SVCV-741 (Asian strains isolated in China) with SVCV-10/3 (Europe reference strain) on their physico-chemical, biological and morphological characteristics. The results indicated that there were no distinct differences between two SVCV strains on phycico-chemical and morphological characteristics. The main existing differences were: (1) The stability of SVCV-741 to temperature in cell culture was higher than that of SVCV-10/3, which might have some evolutionary and biological implication of SVCV; (2) No SVC outbreak ever occurred caused by SVCV-741;Furthermore we found that both SVCV-741 and SVCV-10/3 grew faster and produced higher virus titer in CO cells than other cell lines. It indicated that CO cell lines might be useful tool for SVCV research.

Study on the correlation of serum folate and red blood cell folate level with birth defects and unexplained recurrent pregnancy loss / 中华妇产科杂志

0.05). The RBC folate level of birth defect group except the urinary defect was significantly lower compared with the control group(233-547 vs 689 nmol/L,P