Biomedical subjects

J K Wen

Publications and source records attributed to J K Wen.

30 records · Page 2Linked to original sources

PubMed1991

Two cis-acting regulatory sequences in the peroxisome proliferator-responsive enhancer region of rat acyl-CoA oxidase gene.

To clarify the mechanism of transcriptional induction of the rat liver acyl-CoA oxidase gene by hypolipidemic agents, we searched for cis-acting regulatory sequences in the 5' upstream region of the gene by transfection studies. We found that the sequence between -639 and -472 acts as a peroxisome proliferator-responsive, tissue-specific enhancer. Footprint analysis revealed two protein binding sites in this region. One of these sequences exhibited a positive, whereas the other a negative, regulatory activity in transcription assays.

Acyl-CoA Oxidase↗

PubMed1990

Rat peroxisomal 3-ketoacyl-CoA thiolase gene. Occurrence of two closely related but differentially regulated genes.

We isolated and analyzed the genes for rat peroxisomal 3-ketoacyl-CoA thiolase. Two active genes (termed A and B), both likely to be coding for the peroxisomal thiolase, were identified per haploid rat genome. These genes span approximately 9 and 11 kilobases, respectively, and both contain 12 exons and 11 introns, with overall similar organizations. The nucleotide sequences are highly conserved in the coding regions and in many introns. The A and B genes code for slightly different amino acid sequences, and the known cDNA sequence (Hijikata, M., Ishii, N., Kagamiyama, H., Osumi, T., and Hashimoto, T. (1987) J. Biol. Chem. 262, 8151-8158) corresponds to the B gene product. By in vitro transcription/translation, the A gene was shown to produce a thiolase precursor having a 10-residue longer amino-terminal presequence than that of the B gene product. Primer extension analysis revealed that the A gene is constitutively expressed and is not influenced by the administration of a peroxisome proliferator, whereas the B gene is markedly activated by the same treatment. Several common sequences were noted in the 5'-flanking regions of the B gene and in the genes of two other peroxisomal beta-oxidation enzymes, induced in parallel by peroxisome proliferators.

Acetyl-CoA C-Acyltransferase↗

PubMed1990

Molecular analysis of human acatalasemia. Identification of a splicing mutation.

To search for the molecular defect of Japanese-type acatalasemia, we cloned the mutant catalase gene from a person with this deficiency. The nucleotide sequence of the mutant gene was determined for all exons, exon/intron junctions, and 5' and 3' flanking regions, and the findings were compared with the sequence from the normal gene. Seven base differences were found between the two genes. Among them, a G to A substitution at the fifth position of intron 4 (a splicing mutation) seemed most likely to be responsible for the defective catalase synthesis in the subject. To obtain suggestive evidence, we constructed chimeric genes that contained a segment of either the normal or mutant catalase gene, encompassing a 3' part of exon 4, the entire intron 4 and a 5' portion of exon 5, within the third exon of the human alpha-globin gene. When this chimeric gene construct was introduced into simian virus 40-transformed simian cells (COS-7), the transcript of the normal catalase/alpha-globin chimeric gene was spliced correctly, as revealed by Northern blotting and RNase mapping techniques. In contrast, the splicing of the mutant chimeric pre-mRNA occurred between the 5' donor site of the preceding intron and the 3' acceptor site of the intron containing the substitution, thereby skipping one entire exon sequence. Thus, the G to A transition at the fifth position of intron 4 of the catalase gene indeed severely limits the correct splicing of the RNA product. The same splice site mutation was found in the genomic DNA of another acatalasemic individual from an unrelated family. We suggest that this base substitution is the causal mutation of these cases of Japanese-type acatalasemia.

Acatalasia↗

PubMed1990

The Hall of Dragon Metamorphoses: a unique, indigenous asylum for chronic mental patients in Taiwan.

This paper describes the spontaneous rise of an indigenous asylum for the chronic mentally ill, called Lung Hwa Tang (The Hall of Dragon Metamorphoses), in contemporary Taiwan. Sociocultural factors relevant to the asylum, including the roles played by Chinese families and the current situation of mental health care in Taiwanese communities, are discussed. Despite its detrimental effect on patients, this asylum stands for an alternative mental health care system in the folk sector; it reflects a great demand from the communities for access to modern mental health services, the development of which have been very slow and inadequate in the past four decades in this rapidly developing country.

Adult↗

PubMed1990

Multi-cultural study of minor psychiatric disorders in Asia: symptom manifestations.

Patients with minor psychiatric disorders, including neuroses, situational adjustment reaction or acute emotional reaction, were investigated using symptom questionnaires at five research sites in Asia including: Chiang-Mai, Thailand; Bali, Indonesia; Kao-Hsiung, Taiwan, China; Shanghai, China; and Tokyo, Japan. The results revealed that the symptom profiles differ significantly among groups of different settings indicating that sociocultural background does contribute to the manifestation of neurotic symptomatology. It was also found that numerous and various subtypes of somatic scales were identified through factor analysis of symptoms for these Asian populations. It demonstrates that the spectrum of neurotic symptoms has a different focus for subjects in different sociocultural settings.

Adult↗

PubMed1988

Diminished synthesis of catalase due to the decrease in catalase mRNA in Japanese-type acatalasemia.

In order to characterize the genetic defect in Japanese-type acatalasemia, we examined catalase synthesis in the cultured fibroblasts isolated from a patient suffering from this disease. The transcript of the mutant catalase gene was also analyzed by Northern blotting. It was demonstrated that the severe reduction in catalase protein in the acatalasemic patient is due to the defective synthesis of the enzyme caused by the lack of catalase mRNA. Using Southern blotting, we did not detect large deletion, insertion or rearrangement in the mutant catalase gene as compared with the normal one. We conclude that Japanese-type acatalasemia in this study is resulted by a small mutation in the non-coding region of catalase gene which affects some step in the catalase mRNA metabolism.

Acatalasia↗

PubMed1987