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Biomedical subjects

J G Chang

Publications and source records attributed to J G Chang.

At least 91 records · Page 5Linked to original sources
PubMed1997

Prenatal diagnosis of thalassemia in the Chinese.

There is a high prevalence of thalassemia in the Taiwan area. Prenatal diagnosis of severe forms of thalassemia is important for the prevention of this disease. We performed prenatal diagnosis in 167 cases, of which 59 cases were diagnosed by chorionic villi biopsy, 91 cases by amniotic fluid analysis, and 17 cases by cord blood analysis. Hb Bart's hydrops was detected by amplifying the break junction area of the alpha-thalassemia-1 Southeast Asia (SEA)-type gene, and beta-thalassemia major was detected by using naturally occurring restriction sites and the amplified created restriction sites (ACRS) method. Screening for hemoglobin (Hb) Bart's hydrops revealed 26 cases of Hb Bart's hydrops, 67 cases of alpha-thalassemia-1 (including 6 Hb Bart's hydrops falsely diagnosed as alpha-thalassemia-1 from chorionic villi samples), and 38 normal cases. Screening for beta-thalassemia major revealed 8 cases of beta-thalassemia major, 17 cases of beta-thalassemia minor, and 11 normal cases. In cases of alpha-thalassemia, maternal tissue contamination in the chorionic villi samples occurred in the diagnosis of the carrier state and further amniotic fluid analysis will be necessary. There were no any false-positive or false-negative results in beta-thalassemia major screening. We conclude that prenatal diagnosis is a reliable and accurate screening method for thalassemia and may be valuable in other areas of high prevalence for thalassemia in Southeast Asia and in Southern China.

Gene Frequency↗
PubMed1997

Rapid detection of trisomy 21 by homologous gene quantitative PCR (HGQ-PCR).

Down's syndrome results from the production of three copies of chromosome 21 within a cell. We have devised a method termed the homologous gene quantitative polymerase chain reaction (HGQ-PCR), which uses one pair of primers and which can directly identify the additional copy of chromosome 21 by simultaneously amplifying two highly homologous genes of the human liver-type phosphofructokinase located on chromosome 21 (PFKL-CH21) and the human muscle-type phosphofructokinase located on chromosome 1 (PFKM-CH1) for self-detecting determination. On analysis of 34 cases of Down's syndrome, including two cases of unbalanced translocation 46, XY, der (14; 21) (q10; q10), + 21, and 100 normal individuals, the relative ratio of the PFKM-CH1/PFKL-CH21 product was 1.33 +/- 0.323 (mean +/- SD) and 0.40 +/- 0.16 (mean +/- SD) for disomy DNA and trisomy DNA, respectively. The difference between these two groups was highly significant (P < 0.001). These results indicate that this quantitative method is practical and may be used for the prenatal diagnosis of Down's syndrome caused by trisomy 21.

Cells, Cultured↗
PubMed1997

Molecular analysis of survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes of spinal muscular atrophy patients and their parents.

We have assayed deletions of two candidate genes for spinal muscular atrophy (SMA), the survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes, in 101 patients from 86 Chinese SMA families. Deletions of exons 7 and 8 of the telomeric SMN gene were detected in 100%, 78.6%, 96.6%, and 16.7%, in type I, II, III, and adult-onset SMA patients, respectively. Deletion of exon 7 only was found in eight type II and one type III patient. One type II patient did not have a deletion of either exon 7 or 8. The prevalence of deletions of exons 5 and 6 of the NAIP gene were 22.5% and 2.4% in type I and II SMA patients, respectively. We also examined four polymorphisms of SMN genes and found that there were only two, SMN-2 and CBCD541-2, in Chinese subjects. In our study, analysis of the ratio of the telomeric to centromeric portion (T/C ratio) of the SMN gene after enzyme digestion was performed to differentiate carriers, normals, and SMA patients. We found the T/C ratio of exon 7 of the SMN gene differed significantly among the three groups, and may be used for carrier analysis. An asymptomatic individual with homozygous deletion of exons 7 and 8 of the SMN gene showed no difference in microsatellite markers in the SMA-related 5q11.2-5q13.3. In conclusion, SMN deletion in clinically presumed child-onset SMA should be considered as confirmation of the diagnosis. However, adult-onset SMA, a heterogeneous disease with phenotypical similarities to child-onset SMA, may be caused by SMN or other gene(s).

Adult↗
PubMed1997

Resistance to recombinant erythropoietin in a hemodialysis patient with heterozygous hemoglobinopathy J-Meinung.

The mechanism of resistance to recombinant human erythropoietin (EPO) in hemodialysis patients with hemoglobinopathy is not yet fully understood. Poor responses to EPO have been reported in anemic dialysis patients with sickle cell disease and thalassemia. We present the first case of a hemodialysis patient with EPO resistance and hemoglobin J-Meinung, which is initially found by hemoglobin electrophoresis and finally proven by molecular genetic analysis. Additionally, the patient was diagnosed as having chronic active hemolysis with hallmarks of splenomegaly, an increased serum bilirubin and reticulocyte index, and a reduced haptoglobin level. We discuss the possible mechanisms and proper treatment options in such patients with a poor response to EPO.

Adult↗
PubMed1997

Aberrant FHIT transcripts in acute myeloid leukaemia.

Recently the FHIT gene (fragile histidine triad gene) has been identified at chromosome 3p14.2 and a high frequency of abnormalities in this gene has been demonstrated in various cancers. To determine the role of the FHIT gene in leukaemia, bone marrow or peripheral blood from 62 acute myeloid leukaemia patients and five haemopoietic cell lines (HL60, U937, Raji, KC-1, K562) were analysed by reverse transcription of the FHIT mRNA followed by PCR amplification and sequencing of the products. To detect the deletion of the FHIT gene, 17 cases were evaluated using microsatellite polymorphism analysis. In this study, 17/62 (27%) AML patients expressed aberrant transcripts which lack two or more exons of the FHIT gene, and all the cell lines exhibited the aberrant FHIT transcripts. No cases exhibited a loss of the FHIT alleles. Our data indicated that the FHIT gene may play a role in myeloid carcinogenesis and may be indicated in the late progression of the disease.

Acute Disease↗
PubMed1997

Multiplex mutagenically separated PCR: diagnosis of beta-thalassemia and hemoglobin variants.

A rapid and simple method, termed multiplex mutagenically separated PCR (MS-PCR), was developed to detect several molecular defects in the hemoglobin gene in one PCR. This technique, in which different-size allele-specific primers were used, specifically amplified both normal and mutant alleles of the globin gene in the same reaction. Subsequent gel electrophoresis showed at least one of the two allelic products at the same locus or two of the several allelic products of different loci and provided a within-assay quality control for the exclusion of false-negative results. In our study, the four most common beta-thalassemia mutations, together with four other common hemoglobin variants in Chinese, were tested. Using multiplex MS-PCR 6 to 12 primers were added simultaneously into one reaction tube to identify one to four mutations. Not only is this multiplex MS-PCR method reliable and non-isotopic, the results can be obtained in less than one working day.

Alleles↗
PubMed1997

HLA-DMA and DMB genotyping in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the relation of HLA-DMA and DMB alleles to the development of rheumatoid arthritis (RA). METHODS: We studied HLA-DMA and DMB alleles in 153 patients with RA and 138 healthy controls using the amplification created restriction site method and digestion with restriction enzymes. RESULTS: There was no significant difference in frequencies of HLA-DMA and DMB alleles between patients with RA and controls. The HLA-DMA and DMB alleles were not related to extraarticular involvement, seropositivity for rheumatoid factor, or bone erosion. There was also no significant difference in frequencies of HLA-DMA and DMB alleles among DR4-positive and DR4-negative patients and controls. CONCLUSION: HLA-DMA and DMB do not appear to be associated with the pathogenesis of RA.

Alleles↗
PubMed1996

ABO genotyping by mutagenically separated polymerase chain reaction.

ABO blood groups were determined by the mutagenically separated polymerase chain reaction (MS-PCR). The products from two sets of PCR reactions using the same program for the nucleotides at positions 261 and 703 from cDNA at the ABO locus were used to distinguish A, B and O alleles. Two forward mutagenic allele-specific primers of different lengths for the ABO polymorphic site were paired with the same reverse primer in each PCR reaction. The 216 bp fragment of the PCR products for the 261th nucleotide was A or B allele-specific and the 195 bp fragment was O allele-specific. The 126 bp fragment of the PCR products for the 703th nucleotide was B allele-specific and the 106 bp fragment was A or O allele-specific. The ABO genotypes were determined by the intersection of the predicted alleles from these two PCR reactions. The PCR products were obtained using 10 ng of DNA in 50 microL of PCR reaction mixture, and electrophoresed in 4% agarose gel. In this study, 265 ABO-phenotype known samples (A: 31, B: 48, AB: 6 and O: 180) in Chinese were used. The results of ABO genotypes were AA: 1, AO: 30, BB: 2, BO: 46, AB: 6 and OO: 180. These results were confirmed by the PCR-RFLP ABO genotyping method. This technique is a simple, rapid, and reliable method for ABO genotyping.

ABO Blood-Group System↗
PubMed1996

Polymerase chain reaction diagnosis of Helicobacter pylori in gastroduodenal diseases: comparison with culture and histopathological examinations.

Helicobacter pylori has been associated with a variety of upper gastrointestinal diseases. Histopathological examination and culture are considered to be the more specific tests in the diagnosis of H. pylori infection. In the present study, we evaluated the efficiency of a polymerase chain reaction (PCR) assay of the H. pylori urease A gene as a procedure in the diagnosis of gastric H. pylori infection in various gastroduodenal diseases. Biopsy specimens were obtained from the antral mucosa of 83 patients during endoscopic examination and were submitted to three tests for the detection of H. pylori infection. The detection rates of H. pylori using PCR, histopathological examination and culture were 84, 77 and 63%, respectively. When the infection was defined, by the agreement of culture and histopathological examination or by positive culture, the PCR assay had a sensitivity of 98.1% and a specificity of 84.6%. When the infection was defined by a positive result of either two of the three tests or by positive culture, the PCR assay had a sensitivity of 98.6% and a specificity of 85.7%. We conclude that the PCR assay is a valuable test for the diagnosis of H. pylori infection in gastroduodenal diseases.

Adult↗
PubMed1996

Human cytomegalovirus as a potential etiologic agent in recurrent aphthous ulcers and Behçet's disease.

In a preliminary study on anti-human cytomegalovirus (HCMV) antibody (Ab) by ELISA, the serum anti-HCMV/IgG Ab concentrations in 22 patients with recurrent aphthous ulcers (RAU) in the remission stage were found to be significantly higher than in 22 control subjects (121 +/- 42 vs 100 +/- 27, P < 0.05) and in 39 patients with RAU in the active stage (121 +/- 42 vs 88 +/- 45, P < 0.01). Therefore, the potential of HCMV as an etiologic agent in RAU was proposed and studies using the polymerase chain reaction (PCR) and in situ hybridization (ISH) have been performed to investigate the possible presence of HCMV DNA in pre-ulcerative oral aphthous lesions in patients with RAU or Behçet's disease (BD) of the mucocutaneous type. For this purpose, formalin-fixed biopsy specimens were obtained from 13 pre-ulcerative oral aphthous lesions, 2 samples of normal oral mucosa and 1 ileal mucosal lesion from 9 RAU patients and 4 BD patients. Five specimens of normal oral mucosa from 5 normal control subjects and 12 specimens of oral erosive or ulcerative lesions from 12 patients with erosive lichen planus (ELP) were also included. By PCR, HCMV DNA was detected in 5 of the 13 (38.5%) pre-ulcerative oral aphthous lesions, 3 from RAU patients and 2 from BD patients. The ileal mucosa specimen was also HCMV DNA-positive, whereas HCMV DNA was not demonstrated in any of the 7 specimens of normal oral mucosa from RAU patients and normal control subjects; 12 specimens of oral lesions from ELP patients were similarly negative. ISH did not detect HCMV DNA in any of the biopsy specimens from RAU patients and control subjects. Our findings suggest that HCMV may be an etiologic agent in some cases of RAU and BD.

Adolescent↗
PubMed1996

The effect of "chi-han (hot nature)" Chinese herbs on the secretion of IL-1 beta and TNF-alpha by mononuclear cells.

The effect of "chi-han (hot nature)" Chinese herbs on the secretion of the cytokines IL-1 beta and TNF-alpha was investigated by studying the in vitro effect of the "hot nature" Chinese herbs Radix aconiti, Evodia rutaecarpa, Zingiberis rhizoma, and Cortex cinnamomi. An ethanolic extract of each of these Chinese medicinal herbs was added to human peripheral mononuclear cell culture medium and allowed to react for various specified lengths of time. The culture medium supernatants were collected and tested for their cytokine levels at specified time intervals. We found different reaction patterns of cytokine secretion among these "hot nature" Chinese herbs. Radix aconiti extract showed an augmentative effect on the secretion of cytokines IL-1 beta and TNF-alpha with 20% to 50% concentrations of the pure herbal extract, especially when the reaction time was 18 or 24 hours. Evodia rutaecarpa extract showed a biphasic effect on the secretion of IL-1 beta and TNF-alpha when the reaction time was 18 or 24 hours. The secretion of cytokines was stimulated by low concentrations of the herbal extract, but inhibited by higher concentrations of the extract. Zingiberis rhizoma extract also showed a biphasic effect on the secretion of cytokine IL-1 beta when the reaction time was 18 or 24 hours. As for Cortex cinnamomi extract, no significant augmentative effect on cytokine secretion was found in our study. In consideration of the pyrogenic property of cytokines, it would appear that "hot nature" Chinese herbs can be further divided into different subgroups with minute differences based on their different effects on cytokine secretion.

Dose-Response Relationship, Drug↗
PubMed1995

The effect of Chinese medicinal herb Zingiberis rhizoma extract on cytokine secretion by human peripheral blood mononuclear cells.

The ethanolic extract of the Chinese medicinal herb Zingiberis rhizoma, the rhizome of Zingiber officinale Roscoe (Zingiberaceae), was found to show biphasic effects on secretion of cytokines by human peripheral blood mononuclear cells in vitro. In this study, the augmentative effect of Zingiberis rhizoma extract on cytokine secretion was shown to be time dependent. No significant secretion of cytokine was noted when the reaction time was 1 or 3 h. Secretion of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and granulocyte-macrophage colony-stimulating factor (GM-CSF) by the mononuclear cells was markedly increased in the presence of a low concentration of Zingiberis rhizoma extract, varying from 10-30 mg/ml, when the reaction time was 18 or 24 h. A higher concentration of the herbal extract did not show similar or stronger augmentative effect as did low concentration of the herbal extract.

Cytokines↗
PubMed1995

Rapid detection of hemoglobin variants by mutagenically separated polymerase chain reaction (MS-PCR).

The detection of molecular defects of hemoglobin variants using mutagenically separated polymerase chain reaction (MS-PCR) was applied in this study. Using different lengths of allele-specific mutagenic primers, normal and mutant alleles of hemoglobin genes were amplified in the same reaction tube. Subsequent gel electrophoresis showed at least one of the two allelic products at the same loci or at least two of the several allelic products at different loci. We employed MS-PCR to test the following hemoglobin variants: Hb Constant Spring (Hb CS), Hb E, Hb G-Taichung, Hb J-Meinung, and Hb Kaohsiung. The results were the same as those obtained by amplified created reaction sites (ACRS) or direct sequencing. We conclude that the MS-PCR provides a rapid and simple alternative to other techniques for mutation detection in hemoglobin variants. Moreover, the principle can be extended to other genetic diseases.

Alleles↗
PubMed1995

Treatment and survival of lymphoid malignancy in the north-west of England: a population-based study.

Classification of lymphoid malignancy has changed markedly in recent years and advances have been made in therapy. This study investigated the variations in treatment and survival of 1622 patients in a population-based registry. A total of 1009 cases of malignant lymphoma (ML) were classified according to the Kiel classification. Pathology review resulted in major diagnostic changes for 24% of cases. Of the ML cases, 39% had not had full staging procedures. Younger patients were more likely to have been treated with multiagent chemotherapy regimens, as were patients with B symptoms. Median survival for ML patients was 12 months for high-grade patients and more than 60 months for low-grade patients. Significant factors affecting the survival of ML patients were performance status, whether treatment had followed a recognised protocol, whether treatment had been carried out at a specialist oncology centre (SOC), grade of disease, stage, gender and age. The same factors had a significant effect on survival of the leukaemia patients, except for treatment at an SOC, which had a significant favourable effect on survival of acute lymphoblastic leukaemia (ALL) patients only. Median survival for patients with chronic lymphocytic leukaemia was 43 months and 7 months for ALL patients.

Adolescent↗
PubMed1995

Rapid diagnosis of beta-thalassaemia by mutagenically separated polymerase chain reaction (MS-PCR) and its application to prenatal diagnosis.

We have developed a rapid and simple PCR-based method which is modified from the mutagenically separated polymerase chain reaction (MS-PCR) to detect the molecular defects of beta-thalassaemia. We can use this technique to amplify normal and mutant alleles of the beta-globin gene in the same reaction tube, using different-sized allele-specific primers. This mutagenesis separates the amplification reactions of alleles performed in the same tube. Subsequent gel electrophoresis shows at least one of the two allelic products at the same locus or at least two of the several allelic products at different loci. Therefore, in addition to simple handling, MS-PCR provides a within-assay quality control for the exclusion of false negative results. The five most common mutations of beta-thalassaemia and haemoglobin E which occur in the Taiwanese population were tested, and 14 prenatal samples were checked with accurate results. This method is simple, rapid and accurate, and can be used routinely in prenatal diagnosis. The principle used here can also be applied to other genetic diseases.

Base Sequence↗
PubMed1995

The effect of Evodia rutaecarpa extract on cytokine secretion by human mononuclear cells in vitro.

The effect of Evodia rutaecarpa extract on cytokine secretion by human mononuclear cells in vitro was investigated. Evodia rutaecarpa extract of various concentrations in mononuclear cell culture medium showed biphasic effects on the secretion of interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and granulocyte-macrophage colony stimulating factor (GM-CSF) by the mononuclear cells. Generally speaking, a low to medium level of Evodia rutaecarpa extract, in concentrations ranging from 10% to 30%, showed significant stimulating effects on the secretion of IL-1 beta, IL-6, TNF-alpha and GM-CSF. On the other hand, high level of Evodia rutaecarpa extract, with concentration more than 40%, lost its stimulating effects. Moreover, reaction time affected the stimulating effects of Evodia rutaecarpa extract on cytokine secretion by mononuclear cells. Mononuclear cell culture medium containing Evodia rutaecarpa extract that was allowed to react for 18 or 24 hours showed significantly better stimulating effects than that reacted for 1 or 3 hours.

Cells, Cultured↗