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OBJECTIVE@#To assess the value of single sperm sequencing in preimplantation genetic testing for monogenic disease (PGT-M).@*METHODS@#A Chinese couple with two children whom had died of Spinal muscular atrophy (SMA) and attended the Jiangxi Provincial Maternal and Child Health Care Hospital in June 2020 was selected as the subject. Eleven single sperm samples were isolated by mechanical immobilization and subjected to whole genome amplification. Real-time PCR and Sanger sequencing were used to detect the SMN1 variants in the single sperm samples. Genomic DNA of the wife, her parents and the husband, as well as one single sperm sample harboring the SMN1 variant and two single sperm samples without the variant were used for the linkage analysis. Targeted capture and high-throughput sequencing were carried out to test 100 single nucleotide polymorphisms distributed within 2 Mb up- and downstream the variant site. The haplotypes linked with the SMN1 variants were determined by linkage analysis. Blastocyst embryos were harvested after fertilizing by intracytoplasmic sperm injection. Cells from the trophoblasts of each embryo were biopsied and subjected to whole genome amplification and targeted capture and high-throughput sequencing to determine their carrier status. Chromosomal aneuploidy of wild-type embryos was excluded. An euploid embryo of high quality was transferred. Amniotic fluid sample was taken at 18 weeks of gestation to confirm the status of the fetus.@*RESULTS@#Genetic testing showed that the couple both had deletion of exons 7 ~ 8 of the SMN1 gene. The wife has inherited the deletion from her father, while the husband was de novo. The haplotypes of the husband were successfully constructed by single sperm sequencing. Preimplantation genetic testing has indicated that 5 embryos had harbored the heterozygous variant, 4 embryos were of the wild type, among which 3 were euploid. Prenatal diagnosis during the second trimester of pregnancy has confirmed that the fetus did not carry the deletion.@*CONCLUSION@#By single sperm sequencing and PGT-M, the birth of further affected child has been successfully avoided.
Subject(s)
Humans , Pregnancy , Female , Child , Male , Preimplantation Diagnosis , East Asian People , Semen , Genetic Testing , Muscular Atrophy, Spinal/genetics , Aneuploidy , Blastocyst/pathology , High-Throughput Nucleotide Sequencing , SpermatozoaABSTRACT
Objective:To investigate the effects of dexmedetomidine on the myocardial electrical conduction velocity and the expression and distribution of connexin 43 (Cx43) in rats.Methods:Healthy adult Sprague-Dawley rats of both sexes, weighing 270-330 g, were used.Twelve isolated rat hearts successfully perfused in the Langendorff apparatus were divided into 2 groups ( n=6 each) using a random number table method: control group (group C) and dexmedetomidine group (group D). The hearts were perfused for 15 min with K-H solution, and then the hearts were continuously perfused for 30 min with 37 ℃ K-H solution in group C and with K-H solution containing dexmedetomidine 50 ng/ml in group D. Programmed electrical stimulation was performed after the end of perfusion, the activation latency was recorded, and the electrical conduction velocity of myocardial tissues was calculated, and then the left ventricular myocardial tissues were obtained for determination of the expression and distribution of myocardial Cx43 protein by immunohistochemistry method. Results:Compared with group C, the activation latency was significantly prolonged, the electrical conduction velocity was reduced, and the expression of Cx43 was down-regulated in group D ( P<0.05). Cx43 protein was mostly distributed in intercalated discs at both ends of cells in group C, and there was a tendency for the proteins localized at end-to-end contact sites of ventricular cardiomyocytes to localize at side-to-side contact sites, and the distribution was messy in group D. Conclusions:Dexmedetomidine causes arrhythmia probably through down-regulating the expression of Cx43 protein, changing its distribution, and reducing myocardial electrical conduction velocity in rats.
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Objective:To investigate the effect of diabetes mellitus on pulmonary uptake of sevoflurane.Methods:Twenty patients with type 2 diabetes mellitus, aged 40-64 yr, with body mass index of 18.5-22.9 kg/m 2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, undergoing elective surgery with general anesthesia, served as diabetes group (group D). Twenty non-diabetic patients matched by age, gender and surgery were selected as control group (group C). After anesthesia induction and tracheal intubation, sevoflurane was inhaled at a concentration of 2% (oxygen flow 2 L/min). The inhaled concentration (Fi) and exhaled concentration (Fa) at 1, 3, 5, 10, 15, 20 and 30 min of inhalation of sevoflurane were recorded, and the Fa/Fi ratio was calculated.The time required for the Fa/Fi ratio to reach 0.7 was recorded. Results:Compared with group C, the Fa/Fi ratio was significantly increased at each time point, and the time required for the Fa/Fi ratio to reach 0.7 was shortened in group D ( P<0.05). Conclusion:Diabetes mellitus can reduce pulmonary uptake of sevoflurane in the patients.
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Objective:To evaluate the effect of transcutaneous electrical acupoint stimulation (TEAS) at Neiguan on dexmedetomidine-induced bradycardia in patients.Methods:Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients, aged 20-50 yr, weighing 48-60 kg, scheduled for elective gynecological surgery under general anesthesia, were divided into 2 groups ( n=30 each) using a random number table method: control group (group C) and TEAS group (group T). Dexmedetomidine 1 μg/kg was infused intravenously over 10 min followed by intravenous infusion 0.5 μg·kg -1·min -1 in two groups, and the patients in group T simultaneously received TEAS (frequency 2/100 Hz, disperse-dense wave, intensity 5-10 mA according to the current that could be tolerated) at bilateral Neiguan acupoints.The stimulator was only connected, and no current was given in group C. Before the infusion of dexmedetomidine (T 0) and at 10 min of dexmedetomidine infusion (T 1), mean arterial pressure (MAP) and heart rate (HR) was recorded, and electrocardiogram (ECG) was collected to calculate the PR interval, QT interval, QT interval, Tp-e interval and index of cardiac electrophysiological balance (iCEB). The development of arrhythmia was recorded. Results:Compared with the baseline value at T 0, HR was significantly decreased, and QT interval and PR interval were prolonged at T 1 in two groups, and iCEB was increased, and Tp-e interval was prolonged at T 1 in group C ( P<0.05). Compared with group C, HR was significantly increased, PR interval and Tp-e interval were shortened at T 1, and the incidence of bradycardia and atrioventricular block was increased in group T ( P<0.05). Conclusion:TEAS at Neiguan can decrease the risk of bradycardia induced by dexmedetomidine, and the mechanism may be related to shortening atrioventricular conduction time and reducing heterogeneity of ventricular repolarization in patients.
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OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) for the prenatal diagnosis of a fetus with structural anomaly detected by ultrasonography.@*METHODS@#The fetus and its parents were subjected to chromosomal karyotyping and CMA analysis.@*RESULTS@#The fetus was found to carry a 46,XN,t(8;11)(q21.2;q13) translocation which was inherited from its mother. CMA has found no copy number variations (CNVs) in both parents but a de novo 2.00 Mb microdeletion in the fetus at 8q13.3.@*CONCLUSION@#CMA is capable of detecting microdeletions and microduplications in fetuses with translocations detected by karyotyping analysis.
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Female , Humans , Pregnancy , Chromosome Aberrations , Chromosome Deletion , Chromosomes, Human, Pair 8 , DNA Copy Number Variations , Fetus , Karyotyping , Microarray Analysis , Prenatal DiagnosisABSTRACT
OBJECTIVE@#To assess the value of combined chromosomal karyotyping and chromosomal microarray analysis (CMA) for prenatal diagnosis.@*METHODS@#G-banding karyotyping and CMA were simultaneously performed on 546 women who were subjected to amniocentesis during middle pregnancy.@*RESULTS@#In total 82 cases were detected with chromosomal abnormalities. The two methods were consistent in 43 cases, which included 14 trisomy 21, 6 trisomy 18, 1 trisomy 13, 14 sex chromosomal aneuploidies, 4 chromosomal deletions, 3 chromosomal duplications and 1 sex chromosomal mosaicism. Fifteen fetuses with chromosomal abnormalities detected by CMA were missed by karyotyping analysis, which included 9 microdeletions and 6 microduplications. Sixteen fetuses with chromosomal abnormalities detected by karyotyping analysis were missed by CMA, which included 15 chromosomal translocations and 1 sex chromosomal mosaicism. In 7 cases, the results of karyotyping analysis and CMA were inconsistent. One supernumerary marker chromosome detected by karyotyping analysis was verified by CMA as 9p13.1p21.1 duplication.@*CONCLUSION@#Combined chromosomal karyotyping and CMA can significantly improve the detection rate for chromosomal abnormalities, which has a great value for prenatal diagnosis.
Subject(s)
Female , Humans , Pregnancy , Chromosome Aberrations , Chromosome Disorders , Diagnosis , Genetics , Karyotyping , Microarray Analysis , Prenatal DiagnosisABSTRACT
OBJECTIVE@#To assess the value of preimplantation genetic test (PGT) based on next generation sequencing (NGS) for achieving pregnancy for 71 couples with one partner carrying a reciprocal or Robertsonian translocation.@*METHODS@#Following blastocyst biopsy, whole genome of single cell was amplified, and PGT was performed by NGS. The subjects included 60 couples with one partner carrying a reciprocal translocation and 11 with one partner carrying a Robertsonian translocation. The results of PGT, implantation and prenatal diagnosis for all of the couples were analyzed.@*RESULTS@#In total 301 embryos were obtained for the 71 couples through 92 ovulation cycles, 287 (95.3%) of which were successfully diagnosed by NGS. Eighty-five euploidy embryos were identified for the reciprocal translocation carrier group. In 18 cycles, no euploid embryo was obtained. Cancellation rate for the cycles was 19.5%. For reciprocal translocation carrier group and Robertsonian translocation carrier group, the rates for implantation, early abortion, and clinical pregnancy were 89.3% (42/47), 25.5% (12/47), 63.8% (30/47), and 88.8% (8/9), 22.2% (2/9), and 66.6% (6/9), respectively. The result of prenatal diagnosis was consistent with the that of PGT.@*CONCLUSION@#PGT based on NGS can effectively identify euploid embryos and reduce recurrent abortions and termination of pregnancies, achieving a satisfactory rate for clinical pregnancy.
Subject(s)
Female , Humans , Pregnancy , Fertilization in Vitro , Genetic Testing , High-Throughput Nucleotide Sequencing , Preimplantation Diagnosis , Methods , Translocation, GeneticABSTRACT
OBJECTIVE@#To explore the clinical characteristics and genetic basis for a pedigree affected with propionic acidemia.@*METHODS@#Trio whole exome sequencing (WES) was used to screen potential variants in the proband and his parents. Sanger sequencing was carried out for the elder sister of the proband, and prenatal diagnosis was carried out at 18th gestational week upon the next pregnancy of his mother.@*RESULTS@#Two novel heterozygous variants, PCCA c.1845+1G>A and c.446delA, were detected by WES, for which his father and mother were respectively heterozygous carriers. His elder sister also inherited the PCCA c.1845+1G>A variant from her father, while the fetus was heterozygous for the PCCA c.1845+1G>A variant. Above results were confirmed by Sanger sequencing.@*CONCLUSION@#Identification of the PCCA c.1845+1G>A and c.446delA variants by WES has facilitated genetic counseling and prenatal diagnosis for this family.
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TORCH, which is considered as a series of pathogens, including the Toxoplasma gondii, Rubella virus, Cytomegalovirus or Herpes simplex virus, often infects the pregnant women to induce the the fetus or newborn infection by transplacental infection or exposure to contaminated genital tract secretions at delivery. Increasing evidence have been confirmed that the infection of TORCH may cause the miscarriage, premature birth, malformed fetus, stillbirth, intrauterine growth retardation, neonatal multiple organ dysfunction and other adverse pregnancy outcomes. For most TORCH-infections cases may lacking the effective treatments during pregnancy, and it is important to achieve the effacing monitoring of TORCH infections before and during pregnancy. The laboratory testing of TORCH has the great significance. However, the consensus opinions still need to improve the the standardization of TORCH testing process and the correct interpretation. Based on the characteristics of the TORCH detection method, this article gives a consensus opinion on the standardized detection and clinical application of TORCH from the laboratory perspective according to the characteristics and types of infection of different pathogens.
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OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with N-acetylglutamate synthase deficiency.@*METHODS@#Trio whole exome sequencing (WES) was carried out for the pedigree. Pathogenicity of the identified variant was predicted based on the latest recommendation of the American College of Medical Genetics and Genomics (ACMG). Prenatal diagnosis was provided for subsequent pregnancy through Sanger sequencing.@*RESULTS@#Trio WES showed that the proband has carried compound heterozygous c.68delG and c.796G>C variants of NAGS gene, for which the mother and father were respectively heterozygous carriers. Neither variant was reported previously. Based on the ACMG guidelines, the c.68delG variant was classified as "likely pathogenic" (PVS1+PM2), while the c.796G>C variant was classified as with "uncertain significance" (PM2+BP4). Sanger sequencing validated the above findings, and only detected the heterozygous c.796G>C variant in the amniotic fluid sample. The fetus was followed up till 6 month after birth with no obvious abnormality.@*CONCLUSION@#The compound heterozygous c.68delG and c.796G>C variants of the NAGS gene probably underlay the disorder in this pedigree, and the resulth asenabled genetic counseling and prenatal diagnosis for this pedigree.
Subject(s)
Female , Humans , Male , Pregnancy , Amino-Acid N-Acetyltransferase/genetics , China , Genetic Testing , Mutation/genetics , Pedigree , Prenatal Diagnosis , Urea Cycle Disorders, Inborn/genetics , Exome SequencingABSTRACT
Objective:To determine the changes in the expression of myocardial miRNA and the target genes in the rats with hypothermic ischemia-reperfusion (I/R) arrhythmia.Methods:Clean-grade healthy male Sprague-Dawley rats, aged 2-3 months, weighing 300-400 g, were anesthetized, the chest was opened, and the heart was taken to establish an isolated heart perfusion model.Six successfully perfused isolated hearts were divided into 2 groups ( n=3 each) using a random number table method: control group (group C) and heart I/R group (IR group). The model of hypothermic global I/R injury was established by interrupting perfusion for 60-min followed by 30-min reperfusion in chloral hydrate-anesthetized rats.The arrhythmia score was recorded during reperfusion.High-throughput sequencing was used to identify the differentially expressed miRNAs in two groups.The RNAhybrid and miRanda databases were used to predict the target genes of mRNA regulated by the differentially expressed miRNAs, and the enrichment for target genes was performed by Gene Ontology and KEGG databases, and the miRNAs closely related to arrhythmia and with higher expression were selected to carry out the real-time polymerase chain reaction detection. Results:The results of high-throughput sequencing showed that there were 7 differentially expressed miRNAs (novel-miR-17, novel-miR-19, novel-miR-30, novel-miR-43, rno-miR-122-5p, novel-miR-16 and rno-miR-429) in group IR as compared with group C. There were 4 miRNAs that were closely related to arrhythmia and had higher expression: the expression of novel-miR-17, novel-miR-30 and rno-miR-122-5p was significantly up-regulated, and the expression of rno-miR-429 was down-regulated in group IR when compared with group C ( P<0.05). The miRNA-mRNA correlation analysis revealed that GJA1 gene was the target of novel-miR-17. Conclusion:Myocardial novel-miR-17 is involved in the occurrence of hypothermic I/R arrhythmia probably by acting on GJA1 gene in rats.
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Objective:To compare the effects of desflurane and sevoflurane on cardiac electrophysiological balance in the patients undergoing gynecological surgery.Methods:Forty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients, aged 20-50 yr, weighing 46-73 kg, scheduled for elective gynecological surgery, were divided into sevoflurane group ( n=20) and desflurane group ( n=20) using a random number table method.Colloid solution was intravenously infused for volume expansion after entering the operating room.The patients were tracheally intubated after anesthesia induction and then mechanically ventilated.Sevoflurane group and desflurane group inhaled 1.3 MAC sevoflurane and desflurane, respectively, to maintain anesthesia.The 12-lead electrocardiograms were collected before anesthesia induction (T 1), at 5 min after tracheal intubation (T 2), and 20 min after the concentration reaching the preset concentration (T 3) to calculate QT interval, QTc interval, Tp-e interval, Tp-e/QT ratio and index of cardiac electrophysiological balance (iCEB) and to record mean arterial pressure (MAP) and heart rate (HR). Results:Compared with the baseline value at T 1, MAP was significantly decreased at T 2, 3, and HR was decreased, and QT interval and QTc interval were prolonged at T 3 in two groups, and the iCEB were significantly increased in sevoflurane group ( P<0.05). Compared with those at T 2, MAP was significantly decreased at T 3 in sevoflurane group, and HR and MAP were significantly decreased at T 3 in desflurane group ( P<0.05). The iCEB and Tp-e/QT ratio were significantly decreased and Tp-e interval was prolonged at T 3 in desflurane group when compared with sevoflurane group ( P<0.05). Conclusion:Desflurane has no marked effect on the cardiac electrophysiological balance, and sevoflurane causes a decrease in cardiac electrophysiological stability in the patients undergoing gynecological surgery.
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Objective:To evaluate the changes in the electrical conduction of ventricular myocardium during hypothermic ischemia-reperfusion (I/R) in rats with arrhythmia.Methods:Healthy clean-grade adult male Sprague-Dawley rats, aged 2-3 months, weighing 200-300 g, were studied.The hearts were removed and retrogradely perfused with oxygenated K-H solution in a Langendorff apparatus. Sixteen isolated hearts were divided into 2 groups ( n=8 each) using a random number table method: normal control group (group C) and hypothermic I/R group (group I/R). In group C, the heart was perfused with K-H solution at 37 ℃ for 120 min.In group I/R, the heart was perfused with K-H solution at 37 ℃ for 30 min, and then perfusion was stopped, cardiac arrest was induced through injecting Thomas solution (4 ℃), the area around the heart was protected with low temperature (4 ℃) Thomas solution, and hearts were perfused with 4 ℃ Thomas solution at 30 min after cardiac arrest and with 37 ℃ K-H solution for 30 min staring from 60 min after cardiac arrest.The rats in group I/R were further divided into high-risk subgroup (I/R-H subgroup) and low-risk subgroup (I/R-L subgroup). The time of spontaneous recovery of heart beat and development of arrhythmia were recorded.At the end of reperfusion, the atrioventricular conduction 2∶1 block point (2∶1B) and ventricular electrical conduction velocity (CV) were measured and recorded by program-controlled electrical stimulation. Results:Compared with group C, CV and 2∶1B were significantly decreased in IR-L and IR-H subgroups ( P<0.05). Compared with IR-L subgroup, the time for restoration of spontaneous heart beat was significantly prolonged, the incidence of ventricular fibrillation and arrhythmia score were increased, and CV and 2∶1B were decreased in IR-H subgroup ( P<0.05). Conclusion:The electrical CV of ventricular myocardium is decreased during hypothermic I/R, which may be the mechanism of reperfusion-induced ventricular arrhythmia in rats with arrhythmia.
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Objective:To evaluate the effect of electroacupuncture (EA) on electrophysiological characteristics of ventricular myocardium during myocardial ischemia-reperfusion (I/R) in rats.Methods:Twenty-four clean-grade healthy adult male Sprague-Dawley rats, weighing 280-320 g, were divided into 3 groups ( n=8 each) using a random number table method: sham operation group (group SH), I/R group and group EA.The model of myocardial I/R injury was established by ligating the left anterior descending branch of coronary artery for 30 min followed by 30-min reperfusion in anesthetized rats.Bilateral Neiguan acupoints in forelimbs were stimulated for 30 min during the period of reperfusion in group EA.Heart rate (HR), monophasic action potential amplitude (MAPA), maximum depolarization rate (V max), and monophasic action potential duration at 90% repolarization (MAPD 90) were recorded.The development of arrhythmias and arrhythmias score were recorded during reperfusion. Results:Compared with group SH, HR was significantly decreased, MAPA and V max were decreased, MAPD 90 was prolonged, and the incidence of ventricular premature beat, ventricular tachycardia and ventricular fibrillation and arrhythmias score were increased at T 1, 2 in I/R and EA groups ( P<0.05). Compared with group I/R, HR was significantly increased, MAPA and V max were increased, MAPD 90 was shortened, and the incidence of ventricular tachycardia and ventricular fibrillation and arrhythmias score were decreased at T 2 in EA group ( P<0.05). Conclusion:EA can accelerate myocardial depolarization and shorten repolarization, thus decreasing the occurrence of reperfusion arrhythmia in rats.
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Objective:To evaluate the relationship between decreased atrial myoelectric conduction and gap junction protein 40 (Cx40) and Cx43 in rats with reperfusion atrial arrhythmia.Methods:Sixteen Langendorff-isolated heart perfusion models were randomly divided into control group (group C) and ischemia-reperfusion group (group IR), with 8 rats in each group.According to whether the atrial arrhythmia occurred after reperfusion, group IR was further divided into reperfusion non-atrial arrhythmia subgroup (group R-NAA) and reperfusion atrial arrhythmia subgroup (group R-AA). Group C was balanced perfusion with K-H solution (37 ℃) for 120 min.In group IR, hearts were perfused with K-H solution (37 ℃) for 30 min, perfusion was then stopped, Thomas solution (4 ℃, 20 ml/kg) was injected to induce cardiac arrest for 60 min, the surrounding of the heart was protected with 4 ℃Thomas solution, and hearts were perfused with Thomas solution (4 ℃, 10 ml/kg) again after 30 min of cardiac arrest and then with K-H solution 37 ℃ for 30 min.At 120 min of equilibration or 30 min of reperfusion, the effective refractory period (ERP) and conduction velocity (CV) of the right atrium were measured, the expression of Cx40 and Cx43 in the right atrial myocardium was detected by Western blot, and ratio of Cx40 to Cx40+ Cx43 and the ratio of Cx43 to Cx40+ Cx43 were calculated.Results:The incidence of reperfusion atrial arrhythmia was 38% in group IR.Compared with group C, ERP was significantly prolonged, CV was decreased, the expression of Cx40 and Cx43 was down-regulated, the ratio of Cx40 to Cx40+ Cx43 was increased, and the ratio of Cx43 to Cx40+ Cx43 was decreased in R-NAA and R-AA groups ( P<0.05). Compared with group R-NAA, ERP was significantly prolonged, CV was decreased, the expression of Cx40 and Cx43 was down-regulated, the ratio of Cx40 to Cx40+ Cx43 was increased, and the ratio of Cx43 to Cx40+ Cx43 was decreased in group R-AA ( P<0.05). Conclusion:The decreased atrial myoelectric conduction may be related to the down-regulation of Cx40 and Cx43 expression in rats with reperfusion atrial arrhythmia.
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Objective:To evaluate the effect of electroacupuncture postconditioning on the expression of microRNA-1 (miRNA-1) in rats with arrhythmias induced by myocardial ischemia-reperfusion (I/R).Methods:Twenty-four clean-grade healthy adult male Sprague-Dawley rats, aged 2-3 months, weighing 280-320 g, were divided into 3 groups ( n=8 each) using a random number table method: sham operation group (S group), I/R group and electroacupuncture postconditioning group (EP group). The model of myocardial reperfusion arrhythmia was established by ligating the left anterior descending branch of coronary artery for 30 min followed by 30-min reperfusion in anesthetized rats.The artery was only isolated without ligation after thoracotomy in group S. Bilateral Neiguan acupoints were stimulated for 30 min starting from the time point immediately after reperfusion in EP group.The occurrence of arrhythmia during reperfusion was recorded.The rats were sacrificed at 30 min of reperfusion, and hearts were removed for examination of the pathological changes of the myocardium and for determination of miRNA-1 expression (by quantitative real-time polymerase chain reaction) and expression of Kir2.1 and connexin 43 (Cx43) (by Western blot). Results:Compared with S group, the incidence of arrhythmia was significantly increased, the expression of miRNA-1 was up-regulated, and the expression of Kir2.1 and Cx43 was down-regulated in I/R and EP groups ( P<0.05). Compared with I/R group, the incidence of arrhythmia was significantly decreased, the expression of miRNA-1 was down-regulated, and the expression of Kir2.1 and Cx43 was up-regulated in EP group ( P<0.05). The pathological changes of myocardium were accentuated in I/R and EP groups when compared with S group, and the pathological changes were significantly attenuated in EP group when compared with I/R group. Conclusion:The mechanism by which electroacupuncture postconditioning reduces the occurrence of reperfusion arrhythmia is related to up-regulation of Kir2.1 and Cx43 expression after down-regulation of miRNA-1 expression in rats.
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Objective:To observe the changes in the expression of microRNAs in ventricular myocardium in a rat model of hypothermic ischemia-reperfusion (I/R).Methods:Healthy clean-grade male Sprague-Dawley rats, aged 2-3 months, weighing 300-400 g, were anesthetized with intraperitoneal chloral hydrate.Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O 2-5%CO 2.Sixteen Langendorff-perfused hearts were prepared and divided into 2 groups ( n=8 each) by a random number table method: control group (group C) and hypothermic I/R group (group I/R). The hearts were made globally ischemic for 60 min followed by 30-min hypothermic (4 ℃) reperfusion to establish the model of hypothermic I/R injury.The type and duration of arrhythmia and time of recovery of spontaneous heartbeats were recorded during reperfusion.The rats in group I/R were further divided into low-risk group (I/R-L group) and high-risk group (I/R-H group). The left ventricular myocardium was collected after the end of perfusion for high throughput sequencing to screen the differentially expressed microRNAs, and the reliability of the sequencing results was verified by quantitative real-time polymerase chain reaction.Gene Ontology and KEGG databases were used to analyze the biological regulatory pathways of differentially expressed target genes. Results:Compared with group C, there were 437 up-regulated microRNAs and 242 down-regulated microRNAs in group I/R-L and 419 up-regulated microRNAs and 260 down-regulated microRNAs in group I/R-H.Compared with group I/R-L, 392 microRNAs were up-regulated, and 287 microRNAs were down-regulated in group I/R-H.There were 84 microRNAs with absolute value of fold change ≥2 and significantly differential expression ( P<0.01) among the three groups.Subsequently, 4 microRNAs were randomly selected for validation using quantitative real-time polymerase chain reaction, confirming that the sequencing results were reliable.These differentially expressed target genes were involved in 11 biological processes and 6 KEGG pathways which were related to reperfusion arrhythmia.Potassium ion transmembrane transport and the adrenergic receptor signaling pathway in cardiomyocytes were enriched by the largest number of target genes. Conclusion:The expression of microRNAs in ventricular myocardium changes significantly after heart hypothermic I/R.These differentially expressed microRNAs regulate potassium ion transmembrane transport probably and mainly through the adrenergic receptor signaling pathway in the cardiomyocytes and thus are involved in the occurrence and development of hypothermic I/R arrhythmias.
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Objective@#To assess the value of next-generation sequencing (NGS)-based single nucleotide polymorphism (SNP) haplotyping for preimplantation genetic diagnosis (PGD) for beta-thalassemia coupled with human leukocyte antigen (HLA) matching.@*Methods@#Three couples were recruited. Couple 1 both carried a βIVS-2-654 variation and had previously given birth to a son with β thalassemia major. Couple 2 respectively carried βcd41-42 and βIVS-2-654 but had no history of pregnancy. Couple 3 respectively carried βCD17and βIVS-2-654, and had a daughter carrying βCD17.@*Results@#For couple 1, NGS-SNP typing identified two embryos not only unaffected with thalassemia but also with matched HLA. One blastocyst was transferred and resulted in successful pregnancy. A healthy baby was born at 39th week of gestation. Its umbilical blood was used to treat the sick brother through hemopoietic stem cell transplantation. For couple 2, seven blastocysts were obtained. Second transplantation has resulted in successful pregnancy. Prenatal diagnosis was consistent with PGD. For couple 3, two blastocysts not only unaffected with thalassemia but also with no pathogenic copy number variations were obtained. Transfer of one blastocyte resulted in successful pregnancy, and prenatal diagnosis was consistent with PGD.@*Conclusion@#NGS-based SNP typing is an useful tool for selecting embryos unaffected with beta-thalassemia and matched HLA through PGD.
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Objective@#To delineate the variants spectrum of phenytalanine hydroxylase (PAH) gene among 78 unrelated patients with phenylketonuria (PKU) from Jiangxi province.@*Methods@#The 13 exons and flanking intronic regions of the PAH gene were subjected to PCR amplification and sequencing.@*Results@#A total of 143 variants were detected among the 156 alleles, which included 54 types of variants, which yielded a detection rate of 91.7%. Common variants have included R243Q (26/143, 18.2%), R408Q (10/143, 7.0%), EX6-96A>G (8/143, 5.6%), IVS4-1G>A (7/143, 4.9%), R241C (7/143, 4.9%) and V399V (7/143, 4.9%). In addition, 6 novel variants were detected, which included IVS4-3T>G, Q172H, C284Y, V291L, V329del, and L430R. The variants consisted of missense, splicing, nonsense and deletion variants, which have mainly located in exons 7 (45, 31.5%), 12 (17, 11.9%), 11 (16, 11.2%) and 6 (14, 9.8%).@*Conclusion@#Variants of the PAH gene identified in Jiangxi province mainly involve exons 7, 12, 11 and 6, with the most common variants being R243Q and R408Q. Six novel variants were identified.
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Objective To investigate the electrophysiological characteristics of myocardium after hypothermic ischemia-reperfusion (I/R) in rats with different degrees of arrhythmia using an in vitro experiment.Methods Healthy clean-grade male Sprague-Dawley rats,aged 2-3 months,weighing 300-400 g,were used in this study.The rats were sacrificed after anesthesia,and their hearts were rapidly excised.Sixteen Langendorff-perfused hearts were prepared and divided into 2 groups (n=8 each) by a random number table method:control group (group C) and hypothermic I/R group (group I/R).The hearts were made globally ischemic for 60 min followed by 30-min hypothermic (4 ℃) reperfusion to establish the model of hypothermic I/R injury.The occurrence and duration of arrhythmia and time of recovery of spontaneous heartbeat were recorded during reperfusion.The rats in group I/R were further divided into low-risk group (I/R-L group,ventricular arrhythmia score≤3 points) and high-risk group (I/R-H group,ventricular arrhythmia score＞3 points) according to the arrhythmia score.Monophasic action potential amplitude (MAPA),monophasic action potential (MAP) duration at 50％ and 90％ repolarization (MAPDs0 and MAPD90) and maximum ascending velocity (Vmax) of phase 0 in the endocardium,myocardium and epicardium of the left ventricular anterior wall were recorded at 30 min of equilibration (T0) and 15 and 30 min of reperfusion (T1,2).The effective refractory period (ERP) and ventricular fibrillation threshold (VFT) of the left ventricle were measured by programmed electrical stimulation,and the ERP/MAPD90 ratio was calculated.Results Compared with the baseline at T0,MAPA in the three layers was significantly decreased,and MAPD50 and MAPD90 were prolonged at T1,2 in I/R-L and I/R-H groups,and V in the three layers was decreased at T1,2 in I/R-H group (P＜0.05).MAPD50 and MAPD90 in the three layers were significantly shorter at T2 than at T1 in I/R-L and I/R-H groups (P＜0.05).Compared with group C,MAPDs0,MAPDg0 and ERP in the three layers were significantly prolonged at T1,2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in I/R-L and I/R-H groups (P ＜ 0.05).Compared with I/R-L group,the duration of arrhythmia and MAPD90 and ERP in the three layers were significantly prolonged at T2,the ERP/MAPDg0 ratio was decreased,and VFT was increased in group I/R-H (P＜0.05).Conclusion Myocardial depolarization is inhibited,repolarization duration is prolonged,and electrophysiological stability is decreased after hypothermic I/R in the rats with arrhythmia,and the prolongation of myocardial repolarization and decrease in electrophysiological stability are more obvious in the rats at high risk of arrhythmia.