Objective:Multi-facial reflective type of nano-ultrasound contrast agents（UCAs）loaded with hollow self-decomposable silica nanoparticles（SiO 2 NP）of different particle sizes were prepared to investigate the effect of the particle size of SiO 2 NP on the structural and physicochemical characteristics of the nano-UCAs，as well as on the intensity of ultrasound contrast. Methods:Two types of SiO 2 NP with large and small particle sizes（SiO 2 NP L and SiO 2 NP S）were prepared by adjusting the material ratios，and nano-UCAs with different particle sizes of SiO 2 NP S loaded at a concentration of 2 mg/ml were prepared by the thin film hydration method（SiO 2 NP L@NBs and SiO 2 NP S@NBs），and compared with the commercial SonoVue and the prepared nano-bubbles（NBs）for comparing the particle size，zeta potential and stability，scanning electron microscopy to observe the structure，CCK8 method to assess cytotoxicity，and comparison of ultrasonography imaging intensity in in vivo and in vitro experiments. Results:The particle sizes of the two SiO 2 NP（SiO 2 NP L and SiO 2 NP S）were（213.270 ± 16.890）nm and（53.870 ± 8.246）nm，respectively，and the particle size of the synthesized nano-UCA was SiO 2 NP L@NBs（628.40 ± 89.97）nm and SiO 2 NP S@NBs（493.40 ± 36.35）nm respectively，there was no difference in particle size（ P>0.05）. The scanning electron microscope showed a "fig" structure. The stability of SiO 2 NP S@NBs was better than that of SiO 2 NP L@NBs and SonoVue. Safety tests showed that both SiO 2 NP L@NBs and SiO 2 NP S@NBs were safe and usable. Compared with NBs，the intensity of contrast-enhanced ultrasound contrast in SiO 2 NP@NBs with multiple reflection interfaces was significantly enhanced，and the enhanced intensity of contrast-enhanced ultrasound in vitro and in vivo in the SiO 2 NP L@NBs group was significantly higher than that of the NBs group，the SiO 2 NP S@NBs group，and the SonoVue group（all P<0.05）. There was no significant difference in the enhanced intensity of in vitro contrast-enhanced ultrasound between the SiO 2 NP S@NBs group and that of SonoVue（ P>0.05），and the enhanced intensity of contrast-enhanced ultrasound in vivo was significantly higher than that in the SonoVue group（ P<0.05）. Conclusions:The large and small SiO 2 NPs prepared by adjusting the material ratio do not affect the nanoparticle size of UCA.The ultrasonic enhancement ability of nano-UCA with large particle size SiO 2 NP is stronger，but the stability time at room temperature is shorter than that of nano-UCA with small particle size SiO 2 NP.

Objective:Multi-facial reflective type of nano-ultrasound contrast agents（UCAs）loaded with hollow self-decomposable silica nanoparticles（SiO 2 NP）of different particle sizes were prepared to investigate the effect of the particle size of SiO 2 NP on the structural and physicochemical characteristics of the nano-UCAs，as well as on the intensity of ultrasound contrast. Methods:Two types of SiO 2 NP with large and small particle sizes（SiO 2 NP L and SiO 2 NP S）were prepared by adjusting the material ratios，and nano-UCAs with different particle sizes of SiO 2 NP S loaded at a concentration of 2 mg/ml were prepared by the thin film hydration method（SiO 2 NP L@NBs and SiO 2 NP S@NBs），and compared with the commercial SonoVue and the prepared nano-bubbles（NBs）for comparing the particle size，zeta potential and stability，scanning electron microscopy to observe the structure，CCK8 method to assess cytotoxicity，and comparison of ultrasonography imaging intensity in in vivo and in vitro experiments. Results:The particle sizes of the two SiO 2 NP（SiO 2 NP L and SiO 2 NP S）were（213.270 ± 16.890）nm and（53.870 ± 8.246）nm，respectively，and the particle size of the synthesized nano-UCA was SiO 2 NP L@NBs（628.40 ± 89.97）nm and SiO 2 NP S@NBs（493.40 ± 36.35）nm respectively，there was no difference in particle size（ P>0.05）. The scanning electron microscope showed a "fig" structure. The stability of SiO 2 NP S@NBs was better than that of SiO 2 NP L@NBs and SonoVue. Safety tests showed that both SiO 2 NP L@NBs and SiO 2 NP S@NBs were safe and usable. Compared with NBs，the intensity of contrast-enhanced ultrasound contrast in SiO 2 NP@NBs with multiple reflection interfaces was significantly enhanced，and the enhanced intensity of contrast-enhanced ultrasound in vitro and in vivo in the SiO 2 NP L@NBs group was significantly higher than that of the NBs group，the SiO 2 NP S@NBs group，and the SonoVue group（all P<0.05）. There was no significant difference in the enhanced intensity of in vitro contrast-enhanced ultrasound between the SiO 2 NP S@NBs group and that of SonoVue（ P>0.05），and the enhanced intensity of contrast-enhanced ultrasound in vivo was significantly higher than that in the SonoVue group（ P<0.05）. Conclusions:The large and small SiO 2 NPs prepared by adjusting the material ratio do not affect the nanoparticle size of UCA.The ultrasonic enhancement ability of nano-UCA with large particle size SiO 2 NP is stronger，but the stability time at room temperature is shorter than that of nano-UCA with small particle size SiO 2 NP.

Objective:To investigate the power and prenatal diagnosis strategies of cell-free fetal DNA (cffDNA) testing for chromosomal aneuploidy screening apart from trisomy-13/18/21.Methods:This study collected the clinical data of three cases at high risk of trisomy-16 indicated by cffDNA testing in Hunan Provincial Maternal and Child Health Care Hospital from March 2019 to March 2020. Results of the conventional G-banding karyotype analysis of amniotic fluid, single nucleotide polymorphism array (SNP-array) and low-coverage massively parallel copy number variation sequencing (CNV-seq) of placenta/fetal skin samples were analyzed.Results:(1) cffDNA testing results suggested that case 1-3 were at high risk of trisomy-16 and the Z values of chromosome 16 were 20.57, 24.88 and 17.87, respectively. (2) Karyotype analysis of amniotic fluid samples did not identify any abnormalities in Case 1 and 2, while SNP-array revealed a 19.2 Mb and 23.0 Mb heterozygous deletion at 16p13.3p12.3 and 16q22.1q24.3 in Case 1, and a 16.0 Mb loss of heterozygosity at 16q22.3q24.3 in Case 2. Case 3 had a mosaicism karyotype of 47,XY,+16[3]/46,XY[97] and SNP-array analysis showed no heterozygous deletion greater than 5 Mb or copy number variation. (3) Ultrasonography indicated fetal growth restriction in Case 1 and 2 and fetal death in Case 3. All three pregnancies were terminated. CNV-seq analysis of placental tissue in the center of both fetal and maternal side revealed mosaic trisomy 16, with the copy numbers of chromosome 16 of 2.56/2.70, 2.73/2.82, 2.80/2.81, respectively. However, no copy number variation was detected in Case 1 or 2 by CNV-seq analysis of fetal skin tissues. Conclusions:cffDNA testing has a certain power in detecting trisomy-16 apart from trisomy-13/18/21. For high-risk cases of trisomy-16 indicated by cffDNA testing, SNP-array analysis combined with karyotype analysis is suggested to rule out low-level mosaicism and loss of heterozygosity.

OBJECTIVE: To explore the genetic etiology of a pedigree with mental retardation and hypotonia by using chromosome microarray analysis (CMA), low coverage massive parallel copy number variation sequencing (CNV-seq) and quantitative PCR (qPCR). METHODS: Genomic DNA was extracted from peripheral blood samples from two male patients and healthy members from the pedigree. CNV-seq was carried out for one patient. Suspected CNV was verified by qPCR. CNV-seq or single nucleotide polymorphism array (SNP array) were carried out for another patient and his family members. RESULTS: Both patients showed severe hypotonia and global development delay, in particular language delay. CNV-seq and SNP array indicated that both patients had carried a Xq28 duplication, with spanned 0.26 Mb and 0.42 Mb, respectively. Both duplications encompassed the MECP2 gene. CNV-seq analysis of their family members confirmed that the mother and one sister had carried similar duplications, while an elder brother was normal. CONCLUSION CNV-seq and CMA are rapid and effective tools for the diagnosis of MECP2 duplication syndrome in children with mental retardation, hypotonia and recurrent infections.

OBJECTIVE: To carry out prenatal diagnosis for a fetus with high risk predicted by non-invasive prenatal testing (NIPT). METHODS: Next-generation sequencing (NGS) was used to analyze free fetal DNA (ffDNA) in the maternal plasma. Chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were used to ascertain copy number variation in the fetus and its parents. RESULTS: SNP-array analysis and chromosomal karyotyping revealed that the fetus had a 15.018 Mb duplication at 4q34.1q35.2 and a 7.678 Mb duplication at 21q11.2q21.1, which were derived from a t(4;21)(q34.1;q21.1) translocation carried by its mother. CONCLUSION NIPT is capable of detecting submicroscopic chromosomal abnormalities of the fetus. Combined use of genetic techniques, in particular SNP-array, is crucial for the diagnosis of partial trisomy 21q in this case.

Objective: To carry out genetic testing for a boy presenting with mental retardation and hypoplasia. Methods: Conventional karyotyping, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism based array (SNP-array) were used to analyze the boy and his parents. Results: SNP-array has detected a 25.7 Mb microduplication at 2q33.3q36.3 in the boy. Chromosomal karyotyping and FISH analysis indicated that his mother had a karyotype of 46, XX, ish ins(11; 2)(p15; q33q36), and that the boy has carried an abnormal chromosome 11 derived from the maternal translocation. The karyotype of the boy was ascertained as 46, XY, ish der(11)ins(11; 2)(p15; q33q36)mat. Conclusion SNP-array combined with G-banding and FISH can delineate the cryptic translocation and is valuable for the assessment of recurrence risk for subsequent pregnancies.

Objective: To investigate the genetic etiology of neurodevelopmental disorders (NDD), and to provide a theoretical basis for its genetic counseling, family risk evaluation and prenatal diagnosis. Methods: Karyotype analysis and chromosome microarray analysis (CMA) were conducted of the data from 420 children diagnosed accor-ding to NDD diagnostic criteria at Maternal and Child Health Hospital of Hunan Province from January 2016 to December 2018. Results: Among the 420 cases, 14 cases (3.33%, 14/420 cases) with global developmental disabilities/intellectual disabilities (GDD/ID) had chromosomal abnormalities.The location of chromosome breakpoints and the range of deleted or duplicated fragments in 13 cases were further determined by using CMA.In this study, pathogenic copy number variations (CNVs) were detected in 61 children (14.52%, 61/420 cases), which included 31 cases (50.82%, 31/61 cases) of known syndromes, including Angelman/Prader-Will syndrome (8 cases), Williams syndrome (3 cases), Phelan-McDermid syndrome (3 cases) and other 13 syndromes, and 30 cases with clinically significant pathogenic CNVs.Additionally, by the combination of CMA and fluorescence in situ hybridization (FISH), a family were diagnosed with mental retardation caused by 10q26 and 12p13 occult rearrangement. Conclusions Chromosomal abnormalities and genomic microdeletion/duplication are the primary genetic causes for children with NDD.Combination of karyotype analysis, CMA and FISH can provide definite etiological diagnosis for these children, which has important clinical signi-ficance for the treatment of children and guidance of their parents′ reproduction.

OBJECTIVE: To explore the prenatal screening and diagnosis for a pair of monochorionic-diamniotic (MCDA) twins discordant for 45,X/46,XX mosaicism. METHODS: Amniotic fluid samples were taken from both twins for whom non-invasive prenatal testing has signaled a high risk for sex chromosomal abnormality. Uncultured amniotic fluid was analyzed by fluorescence in situ hybridization (FISH) and single nucleotide polymorphism array (SNP-array). Conventional G-banded karyotyping analysis was performed on the cultured amniotic fluid. RESULTS: Metaphase chromosome analysis showed that one of the twins had a mos 45,X[11]/46,XX[26] karyotype, while the other had a normal karyotype. FISH and SNP-array applied on uncultured amniotic fluid revealed about 30% mosaicism in one of the twins. The twins were confirmed to be monozygotic by SNP-array analysis. CONCLUSION To avoid confusion arising from discordant karyotypes in MCDA twins with abnormal non-invasive prenatal testing (NIPT) results, dual amniocentesis should be carried out to obtain amniotic fluid samples for chromosomal as well as molecular analysis. To determine the ratio of 45,X and 46,XX cells in Turner syndrome can provide valuable information for prenatal genetic counseling.
Amniocentesis ; Chromosomes, Human, X ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Mosaicism ; Pregnancy ; Prenatal Diagnosis

Telemedicine service can effectively improve the diagnosis and treatment, rationally allocate medical resources, and fully reduce medical expenditure, so as to meet people′s health care needs. As introduced by the authors, Beijing Geriatric Hospital provides telemedicine services for chronic diseases guidance, medical consultation and home care services through mobile App, realizing hierarchical medical services, resource sharing and service collaboration in the region, and making up for the shortcomings of time and space in conventional model of face-to-face services. However, in the process of promotion and application, a series of ethical issues have also been found, such as the change of doctor-patient relationship, the protection of patient privacy, the safety of data and information, and the management of medical quality. By discussing the ethical risks in the telemedicine environment and thinking about the relevant countermeasures, we can promote the establishment of a corresponding medical ethics system and promote the sustainable development of telemedicine.

Glutamine is the most abundant amino acid found in plasma and cells. It is the preferred fuel for enterocytes in the small intestine, macrophages, and lymphocytes. After serious burn, increased requirement of glutamine by the gastrointestinal tract, kidney and lymphocytes, and relatively insufficient self synthesis likely contribute to the rapid decline of glutamine in circulation and cells. Glutamine supplementation can not only protect intestinal mucosa, maintain normal intestinal barrier function, reduce bacterial translocation, and enhance the intestinal immune function, but also increase the number of lymphocytes, enhance the phagocytic function of macrophage, promote the synthesis of immunoglobulin, and reduce the body′s inflammatory response, so as to enhance the immune function. Therefore, glutamine supplementation can improve and enhance the immune function, reduce complications and promote the prognosis of severely burned patients.