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J G Chang

Publications and source records attributed to J G Chang.

At least 109 records · Page 6Linked to original sources
PubMed1995

Application of natural and amplification-created restriction sites in prenatal and preimplantation diagnosis of beta-thalassemia.

We attempted the strategy of natural and amplification-created restriction sites for early prenatal and preimplantation diagnosis of Chinese beta-thalassemia. Mutagenesis primers were designed for 11 mutations reported for the Chinese population. The diagnosis was established after polymerase chain reaction and digestion of products by specific enzymes. The results were confirmed by direct sequencing of enzymatically amplified double-stranded DNA. The beta-globin gene was amplified from triploid embryos and isolated blastomeres using mismatched primers. The mutant and normal alleles can be distinguished clearly by this new method. Early prenatal diagnosis was successfully achieved in 9 cases. The beta-globin gene was successfully amplified from single blastomeres and tripronuclear embryos with mismatched primers. Natural and amplification-created restriction sites are a reliable method for rapid prenatal diagnosis of beta-thalassemia. Furthermore, the strategy provides a possible approach for the preimplantation diagnosis of beta-thalassemia.

Base Sequence↗
PubMed1995

Application of ABO genotyping using polymerase chain reaction method to assess engraftment in bone marrow transplantation--a case report.

We described a case of acute promyelocytic leukemia with O blood type who received bone marrow transplantation during a second remission from his HLA identical, B blood type sibling. Using PCR genotyping of the ABO group and analysis of the variable number of tandem repeats of the D1S80 locus, we could quickly document the successful early engraftment in this patient. We emphasize that the use of PCR ABO genotyping is a quick and valuable method which could be applied to assess the engraftment and its follow up in those transplant cases with donors of mismatched blood groups.

ABO Blood-Group System↗
PubMed1995

Clonal analysis in acute myeloid leukemia by polymerase chain reaction.

We have used PCR to amplify a polymorphic portion of the X-chromosome linked phosphoglycerate kinase gene (PGK) combined with a methylation-sensitive restriction enzyme digestion of the active X chromosome to examine the frequency of heterozygosity in Taiwanese females and analyze clonality in 18 female patients with acute myeloid leukemia (AML). We used hair follicles as normal tissue control. We found that the incidence of heterozygosity of the PGK gene in 102 hematological normal females and 18 patients tested was 35% (42/120). In five AML patients, a monoclonal X-inactivation pattern of leukemic blasts was found at presentation, which then returned to polyclonal at remission. In two of these five cases, a monoclonal pattern recurred at relapse. We also found that the hair follicles were readily accessible normal tissue for control, were easy to obtain, and were non-invasive.

Base Sequence↗
PubMed1995

Molecular diagnosis of thalassemia in Taiwan.

Thalassemia is an autosomal recessive disease characterized by absent or decreased synthesis of the globin chain. This disease is very common in Taiwan area. It mainly consists of alpha- and beta-thalassemia. The diagnosis of these entities depends on hemoglobin electrophoresis, mean corpuscular volume (MCV), or mean hemoglobin concentration of red blood cell and excludes the disease of iron deficiency anemia. However, these tests are not reliable. The definite diagnosis is to check the hemoglobin genes directly. In recent years, we have developed several molecular techniques to solve these problems. This review focuses on the techniques which are used recently in Taiwan area.

Female↗
PubMed1995

[Current clinical approaches and gene mutation study of beta-thalassemia major].

Forty-one cases of beta-thalassemia major were assessed for their clinical manifestations and gene mutation. The age distribution was from 1 to 18 years old. Patient's initial clinical symptoms began mostly before 2 years of age (90.2%). Patient's initial hematological data included mean hemoglobin value, 5.8 +/- 1.2 gm/dl, hemoglobin F value, 85.0 +/- 12.1%, hemoglobin A2 value 2.3 +/- 1.8%, reticulocyte count 9.2 +/- 9.0%. Eight different point mutations were characterized. Of these mutations, C to T substitution at nucleotide (nt) 654 of intervening sequence (IVS) 2, accounting for 46.3% of mutant beta-globin genes, is the most common mutation in our series, followed by frameshift codons 41/42 with a four nucleotides (TCTT) deletion for 31.7%; A to G substitution at position -28 of the promotor area for 8.5%; A to T substitution at codon 17 for 6.1%; frameshift codons 27/28 (insertion of C) for 2.4%; G to T substitution at nucleotide 1 of IVS-1 for 2.4%; frameshift codons 71/72 (insertion of A) and IVS-1 3' end TAG-->GAG for 1.2%. The first four mutations account for 92.6% of all beta-globin gene mutations in our series. As to mutations in each individual, the incidence of compound heterozygotes of two different mutations is much higher than homozygotes of a single mutation, 78.0% vs. 22.0%. Compound heterozygotes of C to T substitution at nt 654 of IVS-2 and frameshift codons 41/42 with a four nucleotides deletion is the most common pattern of beta-thalassemia mutation in our patients (41.5%). Patients with beta(0)/-28 beta(+) compound heterozygote mutation had much delayed initial symptoms than beta (0)/beta(0) homozygote mutation, but clinical manifestation may be aggravated when the mutation combined with glucose-6-phosphate dehydrogenase deficiency. Severity of iron overload was significantly correlated with total transfusion amount and patient's age in simple regression analysis (p < 0.001). Splenectomy may effectively prolong transfusion interval, maintain higher hemoglobin level before each transfusion and palliate clinical symptoms (p < 0.01). Iron-chelating agent therapy can effectively lower the total amount of serum ferritin. Higher severity of iron overload correlates with higher incidence of EKG and cardiac abnormalities in patients with beta-thalassemia major.

Adolescent↗
PubMed1995

Genotyping of the DQA1*4 alleles by restriction enzyme digestion of the PCR product from the AmpliType PM kit.

An earlier study has shown that the three DQA1*4 alleles (0401, 0501 and 0601) can be distinguished by restriction enzyme digestion of the polymerase chain reaction (PCR) product derived from the DQ alpha AmpliType kit (Perikin-Elmer, Norwalk, NJ). We have found that the AmpliType PM kit (Perkin-Elmer, Branchburg, NJ) can also be used to achieve the same goal. In this case, a Bio-Profil image analysis system (Vilber Lourmat, Marne La Vallee, France) is used for evaluating the restricted patterns. After typing the six alleles of DQA1 by the AmpliType HLA DQ alpha Detection Reagent Set (Perkin-Elmer, Branchburg, NJ), the PCR products from the PM kit with allele 4 were digested with Fok I and RsaI, separately. Since the other five fragments from PM kit will conceal the digested fragments of the HLA DQA1 PCR products, we measured the optical density of the pre- and post-digested 242 bp fragments in Fok I digestion, and 214/221 bp fragments in Rsa I digestion to decide the results of enzyme digestion. Out of 136 samples used in this study, 61 contain the DQA1 allele 4 determined by the DQ alpha AmpliType method. All 61 were typed with enzyme digestion, of which there are 2.3%, 19.8% and 8.1% in allele 0401, 0501 and 0601, respectively. Our procedure can thus extend the utilization of AmpliType PM kit and increase the discrimination power of the DQA1 system, especially in populations with high distribution of allele 4.

Alleles↗
PubMed1994

Random amplified polymorphic DNA polymerase chain reaction (RAPD PCR) fingerprints in forensic species identification.

The random amplified polymorphic DNA (RAPD) method was used to identify the species of forensic biological samples. Neither genomic DNA sequence nor two polymerase chain reaction (PCR) cycle programs is required. Only single 10-nt primer and one PCR program are used. We demonstrated that this method can be used to identify animals including bovine, goat, pig, dog, rat, rabbit, chicken, duck, and human by comparing their RAPD PCR fingerprints. This study provides a simple, fast and sensitive fingerprinting method in species identification for crime scene evidence or food products of endangered species.

Animals↗
PubMed1994

Molecular basis and hematological characterization of Hb H disease in southeast Asia.

We molecularly characterized sixty-seven cases of Hb H disease by the polymerase chain reaction. The strategy depends on amplifying the alpha-thalassemia-1 (alpha-thal-1) gene by primers flanking the breakpoint and sequence differences of the 3' end of the alpha-globin gene and the nonhomologous elements I, II, and III among different types of alpha-thala-2. In the 67 cases studied, all involved alpha-thal-1 of the Southeast Asia type (SEA) in combination with deletional or nondeletional alpha-thal-2. Thirty-two cases were of the deletion form and 35 cases were of the nondeletion form. In 32 cases of the deletion form, 29 cases were rightward deletion (-alpha 3.7), and three cases were leftward deletion (-alpha 4.2). We found that all of the nondeletion forms were alpha-thal-1 of SEA type with Hb CS. After the subtyping of Hb H with -alpha 3.7, 26 out of 29 were type I deletion and 3 out of 29 were type II deletion. Comparisons of clinical data of deletion forms and the nondeletion form showed that there were earlier occurrence of anemic symptoms and a larger erythrocyte volume in the nondeletion form group (P < 0.005).

Asia, Southeastern↗
PubMed1994

Rapid molecular characterization of Hb H disease in Chinese by polymerase chain reaction.

We have developed a rapid method to molecularly distinguish different types of Hb H disease. The study depended on (a) most of the Hb H disease in Taiwan having an alpha-thalassemia-1 of the Southeast Asia type (--SEA) in one allele and (b) the differences of X box of alpha-globin gene cluster in the other allele. To detect the --SEA allele, we utilized the primers located on either side of the breakpoint to do PCR, then characterized the amplified products. For the other allele, we sequenced part of the X box, and found that bases -2803 to -2461 of the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene. In -alpha 4.2, the bases belonged to the X box of alpha 1 globin gene, whereas in alpha CS alpha it contained both X boxes of alpha 1 and alpha 2 globin genes. There was an MboII site at this region of the X box of alpha 2 globin gene. We utilized PCR to amplify this region and digested it with restriction enzyme MboII, then combined it with another PCR of different types of Hb H disease. One hundred and one cases of Hb H disease from different families were studied: all of the cases had one allele of --SEA deletion, while the other allele showed that 52/101 were -alpha 3.7, 41/101 were alpha CS alpha, 7/101 were -alpha 4.2, and 1/101 was -alpha G. Taichung. Of 52 cases of Hb H with -alpha 3.7, 47 were type-I deletion and five were type-II deletion.

Alleles↗
PubMed1994

Rapid detection of -alpha 4.2 deletion of alpha-thalassemia-2 by polymerase chain reaction.

We sequenced part of the X boxes of alpha-thalassemia-1 of Southeast Asia type (- -SEA) with -alpha 4.2, -alpha 3.7, -alpha G-Taichung, and alpha CS alpha. We found the X box of -alpha 3.7 belonged to the X box of alpha 2 globin gene and the X box of alpha CS alpha contained X boxes of both alpha 1 and alpha 2 globin gene, whereas the X box of -alpha 4.2 and -alpha G-Taichung was a hybrid of X boxes of alpha 2 and alpha 1 globin gene. We also found there are two types of -alpha 4.2 deletion; type 1 is a common type of -alpha 4.2 deletion and type 2 is linkage to -alpha G-Taichung. We used a combination of two methods, the amplification refractory mutation system (ARMS) and the amplified created restriction sites (ACRS), to amplify the hybrids of X boxes specifically. The upstream primer for X box of alpha 2 globin gene was designed following the standard ARMS procedure to amplify the X segment of the alpha-globin gene. The downstream primer was designed according to the ACRS method to check the specificity of PCR products. Using this approach, we can diagnose the different types of -alpha 4.2 deletion. This kind of approach can also be used to amplify the specific region from the cluster of highly homologous genes.

Base Sequence↗
PubMed1994

Molecular characterization of glucose-6-phosphate dehydrogenase deficiency in Chinese infants with or without severe neonatal hyperbilirubinaemia.

To characterize mutations in the glucose-6-phosphate dehydrogenase (G6PD) gene in Chinese infants, we studied 213 G6PD-deficient infants without blood exchange transfusion (BET) therapy, and 34 patients who required BET therapy for their severe hyperbilirubinaemia after birth. Nine different point mutations were characterized in all infants. Of these mutations, the G to T substitution at cDNA nucleotide (nt) 1376, which accounts for the mutations in 131 (53.0%) neonates, followed by G to A substitution at nt 1388 in 18 (10.5%) infants, A to G substitution at nt 493 in 17 (6.9%) infants, A to G substitution at nt 95 in 10 (4.1%) infants, C to T substitution at nt 1024 in six (2.4%) infants, and G to T substitution at nt 392 in three (1.2%) infants, G to A substitution at nt 487 in two (0.8%) infants, C to T substitution at nt 1360 in two (0.8%) infants and C to T substitution at nt 592 in two (0.8%) infants. Mutations in 48 (19.5%) G6PD-deficient infants were not characterized. Most (64.7%) mutations in the G6PD-deficient infants who required BET therapy after birth result from a G to T substitution at nt 1376. The enzyme activity of G6PD deficient infants who required BET therapy is significantly lower than for those who did not, even in a group with the same variant (as in 1376 mutation). Severe neonatal jaundice requiring BET therapy can take place with the majority of variants encountered in this area.

Base Sequence↗
PubMed1994

Diagnosis of thalassaemia by non-isotope detection of alpha/beta and zeta/alpha mRNA ratios.

The alpha/beta and zeta/alpha messenger RNA (mRNA) ratios in the thalassaemia syndromes were investigated by polymerase chain reaction (PCR) with silver staining of the PCR products. In this study we used the PCR to amplify cDNA copies of circulating erythroid cell mRNA in order to measure the relative amounts of alpha-, beta- and zeta-globin contained within. Quantitation was performed by scanning the silver stain of specific globin cDNA bands. We found that there were significant differences of alpha/beta-mRNA and zeta/alpha-mRNA in patients with Hb H disease and alpha-thalassaemia-1 compared to normal subjects. There was a marked increase in the alpha/beta-mRNA ratio but not in the zeta/alpha-mRNA ratio in patients with beta-thalassaemia. In two beta-thalassaemia cases abnormal increases of zeta-globin bands were noted and they were confirmed through DNA analysis to be combined with alpha-thalassaemia-1. This method provides a simple, rapid and non-radioactive approach to detect thalassaemia syndromes, and can help to screen cases of beta-thalassaemia with alpha-thalassaemia-1.

Adult↗
PubMed1994

A rapid method to study the relationship between IDDM and HLA-DQ beta 57 Asp.

We have developed a rapid and simple method to detect the relation between HLA-DQ beta 57 Asp and Chinese IDDM patients. The method involved the selective amplification of a DNA fragment from the HLA-DQ B1 gene by using the mutagenic primers. After PCR, if the HLA-DQ beta 57 was Asp, then there was an artificially created restriction enzyme cutting site. We then can accurately obtain the results by enzyme digestion and electrophoresis. Sixty-nine IDDM patients and 30 nondiabetic control subjects were analyzed using this method. Twenty-two (42%) IDDM patients had non-Asp 57 homozygous, 31/45%) were Asp/non-Asp 57 heterozygous, and 9 (13%) had Asp-57 homozygous. Of the 30 control subjects, the number of cases for these three types were 6 (20%), 18 (60%), and 6 (20%), respectively. The relative risk of homozygous DQ beta 57 non-Asp in our group was 2.9 and the p value was greater than 0.05. Using this kind of approach, we were able to provide a simple, rapid, and non-radioactive method to detect whether the HLA DQ beta 57 was Asp or not.

Adolescent↗
PubMed1994

Prenatal diagnosis of beta-thalassemic mutations in Chinese by multiple restriction fragment-single strand conformation polymorphism analysis.

A modified approach of polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) has been developed for prenatal diagnosis of beta-thalassemic mutations. In this method, a single PCR product (1,350-bp) is first generated, which is then digested by restriction enzymes (BbsI, BamHI, DraI) to generate multiple shorter restriction fragments for electrophoretic analysis in an SSCP gel. The method is thus termed multiple restriction fragment (MRF)-SSCP. Two cases of chorionic samples and the blood samples of their parents were studied. The previously described amplification-created restriction site (ACRS) method was used to confirm the SSCP results obtained. Two polymorphic sites of the beta-globin gene which would influence the MRF-SSCP patterns are described, including a previously undescribed polymorphic site located at codon 3 (CAT or CAC) of the beta-globin gene.

Base Sequence↗
PubMed1994

Molecular basis of beta-thalassemia minor in Taiwan.

The mutations producing beta-thalassemia minor in 227 Taiwanese were studied using the method of naturally and amplified created restriction sites. beta-Thalassemia minor was caused by one beta-globin gene mutation in most of the cases (225/227); only a few cases were caused by two gene mutation (2/227). The most common type of mutation was frameshift codon 41/42 (-TCTT) (93/227), followed in descending order by the C-->T substitution at nucleotide 654 of IVS-2 (83/227), the nonsense mutation A--T at codon 17 (22/227), the A-->T mutation at position -28 of the promotor region (12/227), the frameshift codon 27/28 (+C) (6/227), the initial codon mutation (ATG-->AGG) (5/227), and one each of the codon 71/72 (+A), IVS-1 nt 1 (G-->T), IVS-1 3' end (TAG-->GAG), and nonsense codon 43. In the two cases of the two-gene mutation, one was the nt 654 mutation with Hb Kaohsiung and another one was frameshift codon 41/42 with Hb Meinung. The first four mutations accounted for more than 90% of the mutations. The C-->T substitution at the nt 654 of IVS-2 and initial codon mutation in our study had a higher incidence than in other Southeast Asia areas. Comparison of clinical data in different types of beta-thalassemia showed that there were higher MCV and MCH levels in beta (+)-thalassemia.

Adolescent↗
PubMed1994

A case of simultaneous multiple gastric cancers with p53 gene mutation.

Simultaneous multiple gastric cancers are rarely observed in clinical practice, and its association with p53 gene mutation has not been mentioned in any previous reports. We report a case of advanced gastric cancer with two primary lesions in the stomach who received total gastrectomy. Tumor and surrounding normal tissues from the surgical specimen were studied by using polymerase chain reaction-single strand conformation polymorphism analysis, restriction enzyme digestion method and direct sequencing. Point mutations of p53 gene at codon 248 (CGG-->TGG) were found in both primary tumor foci. The patient developed cancerous peritonitis eight months after the operation and expired six months later. This report suggests that p53 gene mutation can occur at an earlier stage in the tumorigenesis of gastric cancer than previously reported and it might be associated with an unusual clinical and pathological presentation.

Aged↗