Biomedical subjects

Hong-Yu Sun

Publications and source records attributed to Hong-Yu Sun.

6 recordsLinked to original sources

PubMed2006

Successful preimplantation genetic diagnosis for alpha- and beta-thalassemia in China.

METHODS & RESULTS: In southern China, the average carrier rates of alpha-thalassemia and beta-thalassemia in the population are as high as 10.3% and 2.8%, respectively. Because of the high rates, they are known as 'social diseases' in some regions. In this study, the fluorescent gap PCR, which can detect the alpha-thalassemia Southeast Asia deletion (SEA deletion), was applied in four clinical applications of preimplantation genetic diagnosis (PGD) on four couples, among whom both partners were alpha-thalassemia carriers. Two patients became pregnant and two healthy babies were born, which confirmed the PGD results. The single cell multiplex nested PCR followed by reverse dot blot (RDB), which can simultaneously detect the 16 beta-thalassemia mutations in the Chinese population, was applied in four clinical PGD cycles on four couples among whom both partners were beta-thalassemia carriers. One pregnancy was achieved and it resulted in a live healthy birth, which confirmed the results of PGD. The amplification efficiencies of the two protocols described above were 89.5% and 93.9%, respectively. The allele drop-out (ADO) rates of these two protocols were 5.9% and 10.9%, respectively. CONCLUSION: These studies represent the successful applications of PGD protocols that can detect more than 95% of alpha- and beta -thalassemia mutations in the Chinese population.

Adult↗

PubMed2006

[Recent advancement in miniSTR research].

As the most popular and important inherited marker used in forensic identification, short tandem repeat (STR) always have partial DNA profiling or even no results when handling degraded or minute DNA sample. Through redesigning primers close to STR core repeats, MiniSTR can access shorter STR loci and increase success rate of DNA profiling in degraded or minute DNA sample. The review provides an update on the advancement of miniSTR research to give information in the practice of forensic science.

DNA Degradation, Necrotic↗

PubMed2006

[Genetics of heteroplasmy in the mtDNA control region among the Chinese Han population].

OBJECTIVE: To explore the distribution and genetic pattern of heteroplasmy of mtDNA control region among Chinese Han population. METHODS: The human mtDNA control region was amplified into 6 amplicons overlapped partially each other. Then these amplicons were analyzed by DHPLC which we developed to detect low heteroplasmic signals. RESULTS: There were 51 heteroplasmic cases (34%) found from different tissues of 150 unrelated individuals of the Chinese Han population. mtDNA heteroplasmy shows non-uniform distribution in various tissues. The highest occurrence of heteroplasmy was in brain tissues (50/150) and myocardium (48/150), the lowest was in bone tissues (22/150). 36 sites of heteroplasmy were identified in our samples. Three sites of mtDNA heteroplasmy rarely co-existed in one individual. No sex differences were detected in the frequency of mtDNA heteroplasmy. No change in the mtDNA heteroplasmy profile was detected of blood samples from the same individuals within 2 years. Individuals older than 41 years showed a heteroplasmy frequency significantly higher than their younger counterparts. Members from the same maternal pedigree in a family can share the same sites of mtDNA heteroplasmy but may have different heteroplasmy contents at those sites. CONCLUSION: DHPLC is a highly sensitive technique in detecting heteroplasmy. mtDNA heteroplasmy widely exists in the Chinese Han population. The results shown here could potentially have a guidable value in forensic individual identification and parentage testing.

Adolescent↗

PubMed2005

[Successful preimplantation genetic diagnosis for beta-thalassemia using multiplex nested polymerase chain reaction].

OBJECTIVE: To develop single-cell multiplex nested polymerase chain reaction (PCR) assays for preimplantation genetic diagnosis (PGD) in couples at risk of having child with beta-thalassemia. METHODS: Primers were designed and synthesized according to the documented mutation sites common among Chinese. Venous blood was collected from 4 pairs of husband and wife, all heterozygotes for beta-thalassemia, and underwent multiple nested PCR. Intraooplasmic sperm injection and mechanical bio psy was used to obtain single blastomere. Multiplex nested PCR was used to detect the CD41-42 mutation and the closely linked polymorphic marker, HumTHO1 gene or CD41-42, CD41-28, IVSII654 mutation and HumTHO1 gene in the single blastomeres from four clinical PGD cycles. The normal embryos with high scores capable of continuing to divide were transplanted into the uteri. The process of gestation was observed. RESULTS: 200 lymphocytes were amplified by nested PCR. The average amplification rate of the most common 16 beta-thalassemia mutations in Chinese population was 91.3% and the average rate of allele drop out for different sites was 17.0% without differences between any 2 sites. During the 4 PGD cycles 33 embryos underwent bioassay with a success rate of 100%. 33 blastomeres were obtained to undergo PCR, of which 30 were successfully amplified with an amplification rate of 90.9%. Explicit diagnosis was obtained in 26 of the 30 embryos: 7 normal homozygotes, 11 heterozygotes, and 8 abnormal or complex heterozygotes. One or more embryos were transferred back into the uteri of the 4 women and clinical pregnancy occurred in one woman. Five weeks after the implantation B-mode ultrasonography showed monocyesis, and in the 17th week of gestational period paracentesis of cord blood showed normal homozygote. At last a normal female infant confirming the PGD result had been born, which was the first reported unaffected pregnancy resulting from PGD using multiplex nested PCR for couples as beta-thalassemia gene carriers. The results of diagnosis for embryo all corresponded to those for blastomere. The average ADO rate of blastomere was 13.3% (4/30). CONCLUSION: PGD using multiplex nested PCR, as an alternative to prenatal diagnosis, is a reliable and effective way to help couples-carriers of pathogenetic genes to get a healthy baby.

Adult↗

PubMed2003

[Four Y-STR multiplex system by silver staining].

A multiplex PCR system has been developed to amplify 4 Y-chromosome specific short tandem repeats (STR), DYS391, GATA-A4, GATA-A10 and GATA-H4, simultaneously. PCR products were separated by polyacrylamide gels electrophoresis followed by silver stain. When 311 unrelated males from the Han population in Guangdong were detected by the multiplex system, DYS391, GATA-A4, GATA-A10 and GATA-H4 showed 5, 7, 6 and 5 alleles respectively. Total 98 haplotypes could be identified. Gene diversity value for the 4 STR was 0.4623, 0.6972, 0.7173 and 0.6015 respectively. The gene diversity value for the haplotypes of the 4 Y-STR reached 0.9755. The four Y-STR multiplex system will be very powerful for establishing Y-STR database, exploring human origin, paternity testing and personal identification.

English Abstract↗

PubMed2002

Protection of potassium channel inhibitors against hypoxia/reoxygenation-induced death of cultured hippocampal neurons.

OBJECTIVE: To investigate the effects of potassium channel inhibitors on hypoxia/reoxygenation-induced death of cultured hippocampal neurons. METHODS: Cultured 8 d in vitro, hippocampal neurons were exposed to hypoxia (in mixture of 95% N2 and 5% CO2) for 6 h, and then reoxygenated till the 72nd hour. Different potassium channel inhibitors were applied to the culture solution separately after reoxygenation. Neuron death was analyzed with cell counting and MTT assay. RESULTS: Hypoxia/reoxygenation procedure induced a delayed death of cultured hippocampal neurons. Application of tetraethylammonium (TEA) offered concentration-dependent protection of the neurons against death. Selective high-conductance calcium-activated potassium channel (BK) inhibitor iberiotoxin (IbTX) showed significant neuron protection (P<0.001). However, A-type potassium channel inhibitor 4-aminopyridine presented no protection against neuron death (P>0.05). CONCLUSION: Following hypoxia/reoxygenation, enhanced activity of potassium channel, especially BK channel, may induce neuron death.

4-Aminopyridine↗