New Neuroimaging Findings in Patients with Molybdenum Cofactor Deficiency Type A: A Case Report and Literature Review.

INTRODUCTION: Molybdenum cofactor deficiency (MoCD-A) is an extremely rare autosomal recessive disease that presents with intractable seizures. The diagnosis poses challenges due to the limited number of cases reported worldwide. Magnetic resonance imaging (MRI) is a useful diagnostic tool that can detect brain injury associated with the disorder. The prognosis of MoCD-A is poor partly because most cases are initially misdiagnosed as HIE (hypoxic ischemic encephalopathy), emphasizing the need for an early and accurate diagnosis to improve quality of life and provide adequate genetic counseling to avoid new cases in the future. CASE REPORT: This report presents a case of molybdenum cofactor deficiency type A (MoCD-A) caused by MOCS1 gene mutations. A male newborn was admitted on the 10th day of birth due to uncontrolled seizures and feeding difficulties. Brain MRI showed severe cerebral damage with multiple foci that did not enhance upon contrast administration. The diagnosis was confirmed by genetic analysis and the patient received rehabilitation. His parents also received genetic counseling. To the best of our knowledge, this is the first reported MoCD-A case that had enhanced MR imaging with Gd-DTPA (0.1 mmol/kg). In addition, we reviewed the clinical and neuroimaging features of 25 newborns diagnosed with MoCD-A, as documented in the existing literature. CONCLUSION: MRI is crucial in the diagnosis of MoCD-A. A correct diagnosis can provide the family with timely genetic counseling to prevent future cases.

A simple and efficient in planta transformation method based on the active regeneration capacity of plants.

Plant genetic transformation strategies serve as essential tools for the genetic engineering and advanced molecular breeding of plants. However, the complicated operational protocols and low efficiency of current transformation strategies restrict the genetic modification of most plant species. This paper describes the development of the regenerative activity-dependent in planta injection delivery (RAPID) method based on the active regeneration capacity of plants. In this method, Agrobacterium tumefaciens is delivered to plant meristems via injection to induce transfected nascent tissues. Stable transgenic plants can be obtained by subsequent vegetative propagation of the positive nascent tissues. The method was successfully used for transformation of plants with strong regeneration capacity, including different genotypes of sweet potato (Ipomoea batatas), potato (Solanum tuberosum), and bayhops (Ipomoea pes-caprae). Compared with traditional transformation methods, RAPID has a much higher transformation efficiency and shorter duration, and it does not require tissue culture procedures. The RAPID method therefore overcomes the limitations of traditional methods to enable rapid in planta transformation and can be potentially applied to a wide range of plant species that are capable of active regeneration.

Regulatory effect of isovitexin on MAPK/NF-κB signal in mice with acute ulcerative colitis.

The aim of this study was to investigate the anti-inflammatory effects and mechanism of isovitexin on ulcerative colitis mice and RAW264.7 cells. The results showed that isovitexin had strong antioxidant and anti-inflammatory effects, and could restore intestinal barrier integrity (p < 0.01). In addition, isovitexin inhibited the expression of MyD88, TLR4 and NF-κB p65 proteins. At the same time, isovitexin can inhibit the activation of MAPK/NF-κB signaling pathway in RAW264.7 cells. In conclusion, isovitexin has a protective effect on UC mice, and its improvement mechanism of UC might be related to MAPK/NF-κB signaling pathway.

Natural allelic variation confers high resistance to sweet potato weevils in sweet potato.

Sweet potato (Ipomoea batatas L.) is a major root crop worldwide. Sweet potato weevils (SPWs) pose one of the most significant challenges to sweet potato production in tropical and subtropical regions, causing deleterious economic and environmental effects. Characterizing the mechanisms underlying natural resistance to SPWs is therefore crucial; however, the genetic basis of host SPW resistance (SPWR) remains unclear. Here we obtained two sweet potato germplasm with high SPWR and, by map-based cloning, revealed two major SPW-resistant genes-SPWR1 and SPWR2-that are important regulators of natural defence against SPWs. The SPW-induced WRKY transcriptional factor SPWR1 directly activates the expression of SPWR2, and SPWR2, the conserved dehydroquinate synthase, promotes the accumulation of quinate derivative metabolites that confer SPWR in sweet potato. Generally, our results provide new insights into the molecular mechanism underlying sweet potato-SPW interactions and will aid future efforts to achieve eco-friendly SPW management.

Analysis of circRNAs and circRNA-associated competing endogenous RNA networks in ß-thalassemia.

The involvement of circRNAs in ß-thalassemia and their actions on fetal hemoglobin (HbF) is unclear. Here, the circRNAs in ß-thalassemia carriers with high HbF levels were comprehensively analyzed and compared with those of healthy individuals. Differential expression of 2183 circRNAs was observed and their correlations with hematological parameters were investigated. Down-regulated hsa-circRNA-100466 had a strong negative correlation with HbF and HbA2. Bioinformatics was employed to construct a hsa-circRNA-100466­associated competing endogenous RNA (ceRNA) network to identify hub genes and associated miRNAs. The hsa-circRNA-100466▁miR-19b-3p▁SOX6 pathway was identified using both present and previously published data. The ceRNA network was verified by qRT-PCR analysis of ß-thalassemia samples, RNA immunoprecipitation of K562 cell lysates, and dual-luciferase reporter analysis. qRT-PCR confirmed that hsa-circRNA-100466 and SOX6 were significantly down-regulated, while miR-19b-3p was up-regulated. Hsa-circRNA-100466, miR-19b-3p, and SOX6 were co-immunoprecipitated by anti-argonaute antibodies, indicating involvement with HbF induction. A further dual-luciferase reporter assay verified that miR-19b-3p interacted directly with hsa-circRNA-100466 and SOX6. Furthermore, spearman correlation coefficients revealed their significant correlations with HbF. In conclusion, a novel hsa-circRNA-100466▁miR-19b-3p▁SOX6 pathway was identified, providing insight into HbF induction and suggesting targets ß-thalassemia treatment.

Downregulation of lncRNA AFAP1-AS1 by oridonin inhibits the epithelial-to-mesenchymal transition and proliferation of pancreatic cancer cells.

Recent studies have demonstrated that the expression of the long non-coding RNA (lncRNA) AFAP1-AS1 in pancreatic cancer is negatively correlated with survival and prognosis. However, the effects of oridonin and lncRNA AFAP1-AS1 on the epithelial-to-mesenchymal transition (EMT) and migration of pancreatic cancer cells have not been fully elucidated. Surgery is the only potentially curative method for pancreatic cancer, but postoperative recurrence and metastasis are common. The aim of the present study was to assess the effect of oridonin and lncRNA AFAP1-AS1 silencing on pancreatic cancer cells. The pancreatic cancer cell lines BxPC-3 and PANC-1 cells were transfected with siAFAP1-AS1 and its negative control (siNC). After that, oridonin was used to treat the siAFAP1-AS1-transfected cells. The expression of lncRNA AFAP1-AS1 was downregulated in the pancreatic cancer cell lines BxPC-3 and PANC-1. The apoptosis and cell cycle progression of pancreatic cancer cells were evaluated by flow cytometry and Hoechst 33258 staining. Metastasis and invasion of BxPC-3 and PANC-1 cells were detected by transwell migration assay, real-time cell analysis, and western blot analysis. Cells were transfected with the lentiviral siAFAP1-AS1 and siNC, and tumorigenesis was evaluated in BALB/C nude mice. Immunohistochemical examination was used to verify the effects of oridonin and siAFAP1-AS1 on pancreatic cancer. The results demonstrated that the combination of oridonin and siAFAP1-AS1 inhibited pancreatic cancer cell proliferation, induced apoptosis, arrested cell cycle progression, prevented the migration, regulated EMT-related protein expression in BxPC-3 and PANC-1 cells, and inhibited pancreatic cancer cell tumorigenicity and EMT in nude mice.

Risk of dermatologic and mucosal adverse events associated with PD-1/PD-L1 inhibitors in cancer patients: A meta-analysis of randomized controlled trials.

BACKGROUND: Programmed death 1 protein (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors are promising cancer immunotherapy. Their dermatologic safety profiles are still poorly understood. The purpose of this article is to evaluate the incidence of selected dermatologic and mucosal adverse effects (AEs) and determine the risk of developing these adverse events associated with PD-1/PD-L1 inhibitors, compared with chemotherapy or ipilimumab. METHODS: PubMed was searched for eligible studies (up to February 21, 2019). Only phase II and phase III randomized controlled trials (RCTs) compared with chemotherapy or ipilimumab monotherapy were included in this meta-analysis. RESULTS: A total 11,465 patients from 18 clinical trials were included in this meta-analysis. Rash and pruritus were the most frequently reported dermatologic AE, with incidence 11.8% and 12.2% respectively. Compared with patients receiving chemotherapy, PD-1/PD-L1 inhibitor treated patients had higher risk of developing rash (RR = 1.84), pruritus (RR = 3.74) and vitiligo (RR = 9.54), and also lower risk in developing mucosal inflammation (RR = 0.26), stomatitis (RR = 0.26), and alopecia (RR = 0.03). Additionally, anti-PD1/PD-L1 drugs had similar risk of developing rash and lower risk of inducing pruritus compared to ipilimumab. In the subgroup analysis, PD-L1 inhibitor demonstrated better safety than PD-1 inhibitor in developing rash, with RR = 1.38 and RR = 2.11, respectively. CONCLUSION: Our meta-analysis concluded that anti PD-1/PD-L1 drugs have different dermatological and mucosal safety profile compared to conventional therapy, and differences of dermatological toxicity between PD-1 and PD-L1 inhibitor warrant further investigation.

Impacts of Lean Construction on Safety Systems: A System Dynamics Approach.

Lean construction has been viewed as an effective management approach for reducing the occurrence of no-value or destructive activities, such as wasting resources and safety-related accidents. However, few studies have systematically addressed how and to what extent lean construction practices influence construction safety. To bridge this gap, a conceptual model is developed and validated using a system dynamics approach. The construction system in this model comprises four sub-systems (i.e., environment system, equipment system, management system, and employee system). Data were collected from 448 projects in China. Simulations were conducted to determine the correlations between five types of lean tools and the four construction sub-systems. The results show that: (a) 5S management has significant positive impacts on the control of key locations and facilities at construction sites, and contributes to the mitigation of environmental impacts; (b) visual management can significantly improve safety compliance and safety management; (c) just-in-time management has significantly positive influences on the safety facilities layout and formulation of the safety plan; and (d) the Last Planner® System and conference management are effective in improving safety training and the implementation of the safety plan. These findings provide new insights into the use of lean construction for improving construction safety through the implementation of a targeted lean approach.

Benzopyran derivatives from endophytic Daldinia eschscholzii JC-15 in Dendrobium chrysotoxum and their bioactivities.

Five new benzopyran derivatives (2-6) and a new natural product (1) were isolated from endophytic Daldinia eschscholzii in Dendrobium chrysotoxum and determined as (R)-2,3-dihydro-2,5-dihydroxy-2-methylchromen-4-one (1), (2R, 4S)-2,3-dihydro-2-methyl-benzopyran-4,5-diol (2), (R)-3-methoxyl-1-(2,6-dihydroxy phenyl)-butan-1-one (3), 7-O-α-d-ribosyl-5-hydroxy-2-methyl-4H-chromen-4-one (4), 7-O-α-d-ribosyl-2,3-dihydro-5-hydroxy-2-methyl-chromen-4-one (5), daldinium A (6). These compounds were evaluated for their antimicrobial activity, anti-acetylcholinesterase, nitric oxide inhibition, anticoagulant, photodynamic antimicrobial activities and glucose uptake of adipocytes. Some compounds showed photoactive antimicrobial activities and glucose uptake stimulating activities.

New Bisabosquals from Stachybotrys sp. PH30583 Elicited on Solid Media.

Stachybotrys sp. PH30583 cultured in liquid medium only led to one structure type of novel isochroman dimers. Using the one strain-many compounds strategy, the reinvestigation of the metabolites from Stachybotrys sp. PH30583 cultured in rice solid medium led to the isolation of four triprenyl phenols, including two new bisabosquals and two known phenylspirodrimanes. Nitrobisabosquals A and B (1 and 2) are the first case of pyrrolidone-bisabosquals reported in literature. Totally different compounds were isolated using rice solid medium, compared with those isolated using liquid medium, so that rice solid medium presents a key factor in the production of triprenyl phenols. Compound 1 exhibited cytotoxicity against tumor cells, A-549, HL-60, MCF-7 SMMC-7721, and SW480, as well as weak anticoagulant activity with activated partial thromboplastin time (APTT) of 32.1 ± 0.17 s (p < 0.05 vs. Con.) at a concentration of 5 mM. Triprenyl phenol metabolites could be used as chemotaxonomic markers for Stachybotrys.

Invasive prenatal diagnosis of α-thalassemia to control Hb Bart's hydrops fetalis syndrome: 15 years of experience.

PURPOSE: The aim of the present study was to report experiences with invasive prenatal diagnosis of α-thalassemia for the prevention of Hb Bart's hydrops fetalis syndrome in the Guangxi Zhuang Autonomous Region, China. METHODS: Pregnant women and their partners who tested positive for α0-thalassemia or were diagnosed with HbH diseases were counseled and suggested to undergo a prenatal diagnostic procedure for α-thalassemia. Fetal material was obtained by chorionic villus sampling (CVS) between 9 and 13 weeks of gestation, by amniocentesis between 16 and 24 weeks of gestation and by cordocentesis after 24 weeks of gestation. The α0-thalassemia gene types were detected by gap polymerase chain reaction (Gap-PCR). All results were finally confirmed by DNA analysis after delivery or termination of pregnancy. RESULTS: An invasive prenatal α-thalassemia diagnosis was performed in 3155 cases at risk for Hb Bart's hydrops fetalis syndrome at our hospital from 2002 to 2016. CVS was performed in 1559 cases (49.4%), amniocentesis in 1240 cases (39.3%) and cordocentesis in 356 cases (11.3%). In total, 786 fetuses were diagnosed as Hb Bart's hydrops fetalis syndrome. Among these cases, the α-thalassemia genotype was --SEA/--SEA in 784 cases and --SEA/--THAI in 2 cases. All affected pregnancies were terminated in time. CONCLUSIONS: This extensive experience suggests that carrier screening, molecular diagnostics, genetic counselling, and prenatal diagnosis are effective measures to prevent Hb Bart's hydrops fetalis syndrome.

Oridonin inhibition and miR­200b­3p/ZEB1 axis in human pancreatic cancer.

The relationship among oridonin, miR-200b-3p and pancreatic cancer on epithelial-to-mesenchymal transition (EMT) was investigated for the molecular mechanism or signaling pathways on the migration in pancreatic cancer. BxPC-3 and PANC-1 cells were cultivated and the IC50 of oridonin in BxPC-3 and PANC-1 cells were obtained by the CCK-8 array. The expression of miR­200b-3p was verified by using real-time PCR and its target gene was predicted. BxPC-3 and PANC-1 cells were treated with oridonin or transfected by miR-200b-3p, those cells were used for western blot assay, Transwell assay, ELISA, immunofluorescence staining, tumorigenesis assay in nude mice and immunohistochemical assay to verify the effects of oridonin or miR-200b-3p on pancreatic cancer. We found that oridonin inhibited the proliferation of BxPC-3 and PANC-1 cells in a dose-dependent manner. miR-200b-3p was downregulated by oridonin in BxPC-3 and PANC-1 cells. ZEB1 was a target gene for miR-200b-3p. Oridonin or overexpression of miR­200b-3p can inhibit the cell migration in BxPC-3 and PANC-1 cells. miR-200b-3p can inhibit the EMT and oridonin can inhibit the expression of ZEB1, N-cadherin and fibronectin but not increase the expression of E-cadherin, while the cell adhesion molecules ICAM-1 and VCAM-1 were decreased by oridonin in BxPC-3 and PANC-1 cells and the cytoskeleton was altered by oridonin in PANC-1 cells compared with the control. In summary, the results demonstrate that miR­200b-3p was able to inhibit the EMT of human pancreatic cancer in vivo and in vitro by targeted ZEB1. In vitro, oridonin had a certain effect on the migration in BxPC-3 and PANC-1 cells, but not though type III EMT by miR-200-3p/ZEB1 axis, and may be related to type â…¡ EMT, tumor microenvironment or altering the cytoskeleton. In vivo, oridonin inhibited the cancer migration in the nude mouse model though inhibiting EMT.

Anti-phytopathogen, multi-target acetylcholinesterase inhibitory and antioxidant activities of metabolites from endophytic Chaetomium globosum.

Fourteen metabolites with various structure types were isolated from endophytic Chaetomium globosum. Five compounds were separated from genus Chaetomium for the first time. Some compounds exhibited remarkable inhibition against phytopathogenic fungi causing root rot of Panax notoginseng. Compounds 1-5 had significant DPPH-free radical-scavenging activity. Compounds 3 and 5 indicated significant inhibitions against the acetylcholinesterase (AChE). From preliminary structure-activity relationship, it was found that the oxygenic five-membered ring of 3 and 5 was crucial in the anti-AChE activity. These structures provide new templates for the potential treatment and management of plant diseases and Alzheimer disease.

Oridonin alters the expression profiles of microRNAs in BxPC-3 human pancreatic cancer cells.

BACKGROUND: Oridonin, an ingredient used in traditional Chinese medicine, has been demonstrated to play an important role in antitumour effects, but the mechanism underlying its antitumour properties is still not clear. METHODS: To verify the anti-cancer effects of oridonin via a miRNA-dependent mechanism, comprehensive miRNA expression profiling of oridonin-treated BxPC-3 human pancreatic cancer cells was performed using a miRNA microarray assay based on Sanger miR-Base Release 20, followed by a validation using real-time PCR. MicroRNA target prediction and Gene Ontology and KEGG pathway analysis were performed to investigate possible pathways involved. RESULTS: The results showed that 105 miRNAs were significantly differentially expressed (signal reading >500, p ≤ 0.01, |Log2-value| ≥1) in oridonin-treated BxPC-3 human pancreatic cancer cells. CONCLUSIONS: Our data indicates that oridonin inhibits BxPC-3 cells probably through regulating the expression of miRNAs. Interruption of miRNA profiling may provide new therapeutic methods for the clinical treatment of pancreatic cancer.

Antimicrobial metabolites from endophytic Streptomyces sp. YIM61470.

Six compounds were isolated from Streptomyces sp. YIM61470, and their structures elucidated by spectral analysis as (R)-1-O-(phenylacetyl)glycerol (1), 4',5-dihydroxy-6-(3,3-dimethylallyl)-7-methoxyflavanone (2), (32R,33R,34S) -32,33,34,35-bacteriohopanetetrol (3), MKN-003C (4), cyclo (L-Pro-L-Gly) (5), and cyclo(L-Pro-L-Tyr) (6). Compound 1, an chiral monoacylglycerol, was isolated from a natural source for the first time. Compound 2 was first found in microorganisms, and compound 3, a bacteriohopanoid, was found first in the genus Streptomyces. Compounds 1-6 showed weak anti-microbial activity.

[Study on the incidence of beta-Thalassemia and genotypes among children under 7 year-olds in Nanning, Liuzhou and Baise areas, Guangxi province].

OBJECTIVE: To conduct research of beta-Thalassemia incidence and genotypes on children below 7 years of age in Nanning, Liuzhou and Baise areas, Guangxi province. METHODS: A total of 2261 children aged below 7 in Nanning, Liuzhou and Baise areas were studied. Venous blood was detected by routine blood test, hemoglobin analysis and beta-Thalassemia genotyping. RESULTS: Among 2261 samples, 125 showed high level of HbA2 and were diagnosed as beta-Thalassemia (5.53%). Genotypes of the patients were classified as: 59 cases with beta-globin gene condon (CD) 41-42 mutation, 33 cases CD17 mutation, 18 cases with TA TA box nt-28 mutation, 7 with IVS-II-654 mutation, 3 with CD43 mutation, 3 with HbE mutation, one with CD71-72 and TATA box nt-29 mutation, respectively. The genotyping frequencies of beta-Thalassemia were as follows: 47.20% for CD41-42 mutation, 26.40% for CD17 mutation, 14.40% for TATAbox nt-28 mutation, 5.60% for IVS-II-654 mutation, 2.40% for CD43 mutation, 2.40% for HbE mutation, 0.80% for CD71-72 mutation and TATAbox nt-29 mutation respectively. CONCLUSION: This study on children in the area with high incidence of beta-Thalassemia reflected the incidence and characteristics of genotypes in this area. Our data also provided evidence for the development of a program on genetic counseling and prevention for thalassemia.

[Prevalence of hypertension in the Guangxi Bai Ku Yao populations].

OBJECTIVE: To observe the prevalence of hypertension and associated risk factors in the Guangxi Bai Ku Yao populations. METHODS: A total of 1170 subjects of Bai Ku Yao aged 15 and over were surveyed by a stratified randomized cluster sampling. Blood pressure, body height, weight, waist circumference, serum lipid and apolipoprotein levels were measured, and body mass index (BMI) were calculated, matched 1173 subjects of Han Chinese from the same region served as control. RESULTS: The standardized prevalence of hypertension in Bai Ku Yao was significantly lower than that in Han (11.53% vs.16.79%, P < 0.01). The mean levels of systolic, diastolic blood pressure, and pulse pressure in Bai Ku Yao were also significantly lower than those in Han [(115.7 +/- 16.3) vs. (120.0 +/- 16.3) mm Hg (1 mm Hg = 0.133 kPa), P < 0.01; (74.1 +/- 9.4) vs. (75.9 +/- 10.4) mm Hg, P < 0.01; and (41.6 +/- 12.0) vs. (44.2 +/- 11.2) mm Hg, P < 0.01; respectively]. Hypertension was positively correlated with male, age, physical activity, BMI, waist circumference, and the intakes of total energy, total fat, and sodium, and negatively associated with education level in both ethnic groups (P < 0.05 - 0.01), but was positively associated with alcohol consumption only in Han. The rates of awareness, treatment and control of hypertension were significantly lower in Bai Ku Yao than those in Han population [(11.81% vs. 21.76%), P < 0.05; (5.51% vs. 12.95%), P < 0.05; and (2.36% vs. 8.29%), P < 0.05; respectively]. CONCLUSION: The prevalence of hypertension was significantly lower in Bai Ku Yao population than in Han population and diet, low sodium intake, life style, and genetic factors might be responsible for the lower hypertension prevalence in Bai Ku Yao population.

[Prenatal gene diagnosis of paternally inherited alpha-thalassemia by detecting fetal DNA in maternal plasma].

OBJECTIVE: To evaluate the value of diagnosis of alpha-thalassemia by analyzing fetal DNA in maternal plasma. METHODS: Ten families were screened, the husbands being alpha-thalassemia Southeast Asia deletion (SEA alpha-thalassemia-1) heterozygotes and the pregnant women being alpha-thalassemia-2 heterozygotes. Fluorescent polymerase chain reaction (PCR) and gene scanning were used to detect the paternally inherited genotypes of SEA alpha-thalassemia-1 gene mutation and short tandem repeats (STRs) in the maternal plasma fetal DNA. The results were compared to those of conventional prenatal diagnosis of fetal DNA in amniotic fluid, chorionic villus or cord blood. RESULTS: Paternally derived STR genotypes were detected in all specimens of plasma fetal DNA. Paternally inherited SEA alpha-thalassemia-1 gene mutation was detected in 4 cases, while the other 6 cases did not inherit the paternal mutation. The results were completely concordant with those of the conventional prenatal diagnosis. CONCLUSION: Noninvasive prenatal diagnostic method, the technique using fluorescent PCR and gene scanning to detect the fetal DNA and paternally inherited SEA alpha-thalassemia-1 gene mutation in maternal plasma helps exclude the fetuses with hemoglobin H diseases.

[Prenatal diagnosis of Thailand deletion of alpha-thalassemia 1].

OBJECTIVE: To conduct prenatal diagnosis on the couples carrying Thailand deletion (--THAI) alpha-thalassemia 1 and at high risk of having fetus with alpha-thalassemia. METHODS: Genotypes of couples and fetuses were analyzed by PCR and DNA sequencing. RESULTS: Four pregnant women were patients with Hb H diseases of --THAI compounding with alpha-thalassemia 2, while their husbands were heterozygote of the Southeast Asian type alpha-thalassemia 1 (--SEA). Another 5 families, either husbands or wives were heterozygote of --THAI or --SEA. The genotypes of their fetuses were as follows: 2 cases with Hb Bart's hydrops fetalis syndrome, 1 Hb H disease, 4 alpha-thalassemia heterozygote and 2 normal. The DNA sequencing approved the PCR results. CONCLUSION: The study on prenatal diagnosis of Thailand deletion alpha-thalassemia 1 is of importance to the genetic counseling and prenatal diagnosis of alpha-thalassemia.

[Non-invasive prenatal genetic diagnosis of beta-thalassaemia using single fetal nucleated erythrocyte from maternal blood].

OBJECTIVE: To investigate non-invasive prenatal genetic diagnosis of beta-thalassaemia using a single fetal nucleated erythrocyte (NRBC) from maternal blood by comparing with the genotype obtained from chorionic villus or amniocytes, and to evaluate the diagnostic results in reliability and feasibility of this method. METHODS: Maternal blood samples were obtained from 28 pregnant women at risk of beta thalassaemia during 9 - 34 weeks of gestation. NRBCs in maternal blood were enriched by single density gradient separation, stained with benzidine, and then collected by micromanipulation individually. After primer extension preamplification (PEP) of the entire genome from each single NRBC, short tandem repeat (STR) genotype was analyzed after further amplification of this gene. Single NRBC was tested individually to identify if it was fetal or maternal in origin by STR genotype of NRBC and its corresponding parents. beta-globin DNA fragments were amplified with nested-PCR using PEP product of a single fetal NRBC that was determined to be fetal in origin. Fetal beta-globin genotypes were analyzed by reverse dot-blot hybridization (RDB), the accuracy was evaluated by comparing with genotype which had been determined on DNA obtained from chorionic villus (CVS) or amniocytes. RESULTS: A total of 298 NRBCs were found in all of 28 pregnant women at a range of 4 to 13 per 5 ml venous blood. After PEP, about 43.6% of NRBCs were determined to be fetal in origin by STR typing. Using PEP product of a single fetal NRBC as template, beta-globin DNA fragment was examined on agarose gel after nested-PCR, amplification efficiency was 90.8% (118/130). Fetal beta-globin genotypes were achieved successfully in all cases with RDB. Comparing with the genotypes which were obtained from CVS or amniocytes, the rate of diagnostic accuracy was 85.7% (24/28). CONCLUSIONS: PEP technique and STR genotype analysis provide effective method for identification of single nucleated erythrocyte from maternal blood in origin. With the techniques PEP and RDB, fetal beta-globin genetic diagnosis was achieved using a single fetal NRBC from maternal blood. The method had a high accuracy and reliability in diagnosis. It may become an optional approach to non-invasive prenatal diagnosis of beta-thalassemia.