Biomedical subjects

Guo-di Chen

Publications and source records attributed to Guo-di Chen.

6 recordsLinked to original sources

PubMed2006

[Analysis of the multi-amplified 5 STR loci and their allelic distribution in both Han populations in Chengdu City and Yunnan province].

OBJECTIVE: To illuminate the multi-amplified 5 STR loci and their allelic distribution in Hans by means of STR-DNA typing with improved efficiency and decreased cost. METHODS: We have established an allelic ladder of D7S820, D13S317, D5S818, D3S1358 and Amelogenin loci via the cloning techniques. With this homemade allelic ladder, we established successfully a multiplexing polymerase chain reaction (PCR) method, followed by denaturing polyacrylamide gel electrophoresis (PAGE) and silver staining. DNA samples collected from 130 unrelated Han individuals in Yunnan and Chengdu were analyzed. The non-overlapping of the allelic fragments of the five loci allowed the detection to be accomplished successfully. RESULTS: No difference of the genotyping results of the single locus amplification and multiplexing was observed. The genotype distributions of 4 STR were in accordance with the Hardy-Weinberg equilibrium. 7, 7, 8 and 8 alleles of D7S820, D13S317, D5S818, and D3S1358 loci were observed in Yunnan Han population, as well as 8, 7, 8 and 7 alleles in Chengdu Han population respectively. No significant difference in the allele distribution of these loci was seen between these two Han populations. CONCLUSION: This multiplexing system with home-made allelic ladder has a high combined discrimination power and exclusion power. It is a valuable tool in forensic science practice.

Alleles↗

PubMed2005

[Primary study on the influence of blood transfusion on the STR genotypes of recipient's blood].

OBJECTIVE: To investigate whether any change occurred in recipients' blood collected at different times after transfusion with different quantity of blood. METHODS: Three patients were transfused with 400 ml, 800 ml and 1200 ml blood separately. The blood samples were collected from the recipients before transfusion and at 4 h, 8 h, 12 h after transfusion, and from the donors. DNA were extracted by Chelex-100 method and were amplified by the polymerase chain reaction (PCR). Six loci of D1S549, D18S865, D3S1754, D12S391, D12S375, D6S477 were selected. The PCR products were analyzed by polyacrylamide gel (PAG) vertical electrophoresis and silver staining. RESULTS: The investigations on the six STR loci revealed that the patients' STR genotypes remained unchanged within 12 h after blood transfusion. CONCLUSION: The STR genotypes of the donors would have no influence on the STR genotypes of the patients within 12 h after transfusion providing the volume of blood transfused is less than 1200 ml.

Asian People↗

PubMed2004

[Further study on heterogeneic basis of complement C8 beta deficiency].

OBJECTIVE: In Caucasian population, the most common molecular basis for C8 beta deficiency s a single C to T transition in exon 9 of C8 beta gene resulting in a stop codon. In previous family studies, two individuals were identified with C8 beta complete deficiency and were found to be only heterozygous for this mutation. This study was conducted by the present authors in search of other possible causes for these two C8 beta deficient individuals. METHODS: Using direct DNA sequence analysis of all exon-specific PCR products of the C8 beta gene from these two C8 beta deficient patients and their descendants. RESULTS: Two other C to T transitions at base 298 and 388 in exon 3 were detected, which could also create a termination codon. The descendants from one of the deficient patients were also analysed for the mutations, and it could be demonstrated that the two C to T mutations in exons 9 and 3 are segregating independently. CONCLUSION: These two mutations, which create a termination codon, are sufficient to explain the complete C8 beta deficiency in both patients.

Codon, Nonsense↗

PubMed2004

[Polymorphisms of five short tandem repeat systems in Chinese Zang population in Kangba area].

OBJECTIVE: To get preliminary genotype and allele frequency distributions of D1S549, D3S1754, D12S391, D12S375 and D18S865 loci in Chinese Zang (Tibetan) population in Kangba area and to validate more short tandam repeat (STR) systems for forensic application. METHODS: Fresh samples of venous blood from 100 unrelated individuals of Chinese Zang population in Kangba area were dropped on the filter paper. After they dried up, DNA were extracted by chelex-100 method and amplified by the polymerase chain reaction (PCR). The PCR products were analyzed by PAG vertical electrophoresis and silver staining. RESULTS: Seven alleles were found at D1S549 locus, six alleles at D3S1754 locus, ten alleles at D12S391 locus, six alleles at D12S375 and six alleles at D18S865 locus. No deviations from Hardy-Weinberg equilibrium were observed. The heterozygosities observed were 0.86, 0.77, 0.81, 0.69, 0.80 for D1S549, D3S1754, D12S391, D12S375 and D18S865 respectively. The calculated values of the Power of Exclusion were 0.715, 0.545, 0.618, 0.413 and 0.599, and the values of the Power of Discrimination were 0.929, 0.838, 0.934, 0.886 and 0.890, respectively. CONCLUSION: All of the five loci in this study were useful for individual identification and paternity test, as well as for research purposes in genetics.

Alleles↗

PubMed2004

[Analysis of p53 gene mutation in esophageal exfoliative cells].

OBJECTIVE: To explore the feasibility of detecting p53 gene mutation in exfoliative esophageal cells, and compare gene mutation between precancerous lesions and normal esophageal exfoliative cells and correlate p53 gene mutation with esophageal carcinogenesis. METHODS: Forty-eight samples (24 normal squamous epithelia and 24 severe squamous dysplasia) were obtained by balloon cytologic technique from a high incidence area, Yanting county, Sichuan Province, China in 1982. p53 gene mutations in exons 5 and 7 were analyzed by PCR-SSCP. RESULTS: p53 genes were detected in all samples. Five samples with p53 mutation were detected in exon 7 and no mutation was detected in exon 5 in 24 severe dysplasia samples. Three of the 5 samples with mutation in exon 7 developed esophageal cancer in 1992, 1994 and 1996 respectively. No p53 gene mutation was detected in exon 5 and 7 in normal exfoliative samples. CONCLUSION: p53 mutation may have occurred in the precancerous lesions which contributes in the initiation of human esophageal carcinogenesis.

Adult↗

PubMed2002

[A study of forensic individual identification used STR locus with silver staining and multiplex PCR methods].

Amplification of short tandem repeat(STR) loci has become a useful tool for human identification applications. To improve throughput and efficiency for the forensic materials and gain foure and six STR locis multiplex methods with silver staining, CSF1PO,TPOX,THO1 and vWA(referred to as multiplex A), D18S51, D7S820, D13S317, D5S818, D3S1358 and Amelogenin(referred to as multiplex B) have been evaluated for use in a rape case. The products of multiplex amplication were separated in a denaturing polyacrylamide gel and analyzed with silver staining. Two multiplex amplications used in this case could provide a power of discrimination of approximately 2.43 x 10(-19). Silver staining was shown to be a validation methods for analysing the products of four and six multiplex amplications.

English Abstract↗