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N C Chang

Publications and source records attributed to N C Chang.

9 recordsLinked to original sources
PubMed1992

Molecular cloning and characterization of a mouse alpha 2C2 adrenoceptor subtype gene.

A clone MA2C2 encoding the murine homologue of adrenoceptor alpha 2C2 was isolated from a mouse genomic library using a subtype specific probe. The nucleotide and the deduced amino acid sequences derived from an ApaI fragment (2 kb) of the clone reveal a single open reading frame encoding a putative receptor protein of 455 amino acids. The 5' untranslated region (0.5 kb) sequenced is characterized by high GC content and CpG island count.

Amino Acid Sequence↗
PubMed1992

Characterization of a glial associated antigen GA-1 by monoclonal antibody.

A glial antigen (GA-1) was identified by monoclonal antibodies (MAb) raised against C6 rat glioma cells. MAb-7D3 (IgG2a kappa) revealed GA-1 as a single protein band with a Rf value of 0.09 by the use of basic-PAGE Western blot. SDS-PAGE Western blot and radioimmunoprecipitation (RIP) further resolved GA-1 into two subunits with a molecular weight of 200 and 78 kDa respectively. Subcellular localization by immunocytochemical staining revealed its cytosolic presence with a punctate pattern perinuclearly. Significant expression of GA-1 may be detected in 4 glioma or glial cell lines derived from rat brain. However, no expression may be detected in the rest of the 18 mammalian cell lines or primary neural cell cultures examined. All of the above data thereby suggest that GA-1 may be glial specific whereas the epitope of GA-1 defined by MAb-7D3 is species (rat) specific.

Animals↗
PubMed1990

In vitro amplification by polymerase chain reaction of a partial gene encoding the third subtype of alpha-2 adrenergic receptor in humans.

In order to clone the third subtype of human alpha-2 adrenergic receptor, polymerase chain reaction (PCR) was employed. Primer pairs corresponding to the conserved sequences in transmembrane domains III and VI were used to selectively amplify the adrenergic receptor genes of the alpha-2 type from human genomic DNA. Sequence data obtained from a clone PCRA2, 885 bps in length, revealed the presence of significant (80%) homology with the known alpha-2A and 2B subtypes of human in the transmembrane domains, whereas distinct variations were noted in the third cytoplasmic loop. When compared with a recently reported alpha-2 receptor gene of rat, essentially identical sequences were found in the transmembrane domains III-VI, except one amino acid in domain VI. As high as 65% homology was also found in the third cytoplasmic loop. We suggest this in vitro amplified fragment represents the partial gene of the third subtype of alpha-2 adrenergic receptor in human.

Amino Acid Sequence↗
PubMed1990

[Cloning and sequencing of hemolysin gene from clinical Aeromonas hydrophila].

Aerolysin is one of the important virulence factors for Aeromonas hydrophila infection. To understand the characteristics of the aerolysin gene in clinical A. hydrophila, a genomic library was constructed by using pUC19 as cloning vector. The positive clone containing the aerolysin gene was selected by the colony hybridization method, using the aerolysin probe (an 48 mer oligonucleotide) of aquatic A. hydrophila. Four positive out of 1,200 transformants were obtained from the primarily screened genomic library, and were further identified for specific binding capability by the dot blot hybridization method. One of three positive clones, designated as pAH-1, was further analyzed by the restriction mapping technique. For further sequencing the aerolysin gene nucleotides, the 3.0 kb fragment of A. hydrophila isolated from pAH-1 was cloned into pBluescriptII, pKS+, resulting in plasmid pKAH-1. Subclones of pKAH-1 were constructed and determined for the presence of 48 mer aerolysin gene sequence by dot blot hybridization method. These (subclones pKS+SS and pSK+SS) were selected for nucleotide sequencing by single-stranded dideoxy sequencing method. The nucleotide sequence similarity coefficient between clinical and aquatic strains of A. hydrophila was 76%; whereas between clinical strains of A. hydrophila and A. sobria was 71%. Since the length of the A. hydrophila DNA fragment cloned into pAH-1 is 3.0 kb, a larger size than the aerolysin gene of aquatic A. hydrophila (1.45 kb) and, also, includes 3' region of aerolysin gene in aquatic A. hydrophila, the indication is that the clone, pKAH-1, contains an entire aerolysin gene of A. hydrophila. The similarity between a small region (containing 8 amino acids) of the aerolysin in the clinical A. hydrophila and the alpha toxin of Staphylococcus aureus suggests that there is functional significance in this region.

Aeromonas↗
PubMed1989

Autopsy statistics on the relative frequency of acute myocardial infarction in the Japanese mental workers and the unemployed during the two oil-crises periods.

In order to investigate whether job induced emotional stress, arising from socioenvironmental disasters would act as a trigger for the onset of AMI, the author reviewed all pathological autopsies throughout Japan 15 years old and over. Data was obtained from publications of the "Annual of the Pathological Autopsy Cases in Japan" for the years 1966-1968 (a period of high economic growth), 1973-1975 (1974, the year of the first oil crisis), and 1978-1980 (1979, the year of the second oil crisis). Relative frequencies of AMI were significantly higher during the years of both oil crises than in both the preceding and following years (2.6% in 1973, 3.7% in 1974, 3.0% in 1975; 2.8% in 1978, 3.2% in 1979, and 2.0% in 1980), and in each of three years of the high economic growth period (1.9-2.2% in 1966-1968). The proportions of managers and officials among AMI victims were significantly higher in the years of both oil crises than in both the preceding and following years (13.4% in 1973, 17.5% in 1974, 12.5% in 1975; 11.6% in 1978, 15.8% in 1979, and 11.1% in 1980). Moreover, there was a significantly higher value in the year of first oil crisis than in each of three years of the high economic growth period (11.7-13.1% in 1966-1968). The proportions of "out of job" persons were also significantly higher in the years of both oil crises than in the preceding years (24.0% in 1973, 29.3% in 1974, 27.8% in 1975; 24.1% in 1978, 29.1% in 1979, and 27.4% in 1980). For 11,199 randomly selected autopsies, the proportions of AMI in the above two occupational groups were significantly higher in the years of both oil crises than in the preceding years. Moreover, the proportion of "out of job" persons was significantly higher in the year of first oil crisis than in each of three years of the high economic growth period. A similar trend was noted among professional and technical workers, with more AMI occurring in this group during the years of both oil crises than in both the preceding and following years but without statistically significant difference.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1975

Ether lipid metabolism. Incorporation of O-hexadecyl ethanediol into rat brain lipids.

1-O-[1'-14C]Hexadecyl ethanediol was administered intracerebrally to myelinating rat brain, and incorporation of radioactivity into brain lipids was followed over a 48-h period: (1) O-Hexadecyl ethanediol was metabolized primarily through oxidative ether bond cleavage, and much of the label was recovered in phospholipid acyl groups. (2) Substantial amounts of radioactivity were also found in choline and ethanolamine phospholipids having an O-hexadecyloxyethyl glycerol backbone. This means that alkyl ethanediol was used in glycerol ether biosynthesis as are long-chain primary alcohols. (3) Acidic hydrolysis of the ethanolamine glycerophosphatide fraction yielded also labeled hexadecanol which may indicate desaturation of 1-O-hexadecyloxyethyl 2-acyl glycerophosphoryl ethanolamine to the plasmalogen analogue. (4) Small amounts of the substrate were oxidized to O-hexadecyl glycolic acid and incorporated into the phospholipids. The substrate did not serve as precursor of O-hexadecyl ethanediol phosphorylcholine or phosphorylethanolamine in the brain.

Animals↗
PubMed1975

Evaluation of mammographic calcifications using a computer program.

A computer pattern recognition program was developed to evaluate calcifications seen on mammograms. When the approximate horizontal length, average internal gray level, and contrast were used as criteria, 84.3% of the lesions studied were correctly identified as malignant or benign. These results show that a computer program can help evaluate calcifications of the breast.

Breast Neoplasms↗