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Biomedical subjects

N C Chang

Publications and source records attributed to N C Chang.

33 records · Page 2Linked to original sources
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↗
PubMed1983

Rheumatic diseases in China.

Prevalence and clinical manifestations of 5 common rheumatic diseases in China are discussed. Systemic lupus erythematosus appears to be more prevalent in Chinese than in Caucasians with possibly different clinical manifestations, in particular less serositis. Rheumatoid arthritis may be less aggressive and seronegative arthridities are less common. Behçet's and aortitis are frequently seen but not temporal arteritis and polymyalgia rheumatica.

Aortitis↗
PubMed1983

Differential effects of chronic monocyte depletion on macrophage populations.

The administration of the bone-seeking isotope, 89Sr, to mice results in severe monocytopenia without any apparent effect on the numbers of resident peritoneal macrophages (Mphi). An explanation for this dichotomy was sought by determining whether the residual blood monocytes were still an effective source of Mphi after 89Sr treatment. Stem cell enumeration showed that a 90% fall in bone marrow macrophage colony-forming cells after 89Sr was accompanied by a 10-fold rise in splenic M-CFC. Splenectomy performed before 89Sr treatment, however, resulted in little additional monocytopenia and had no affect on the numbers of resident peritoneal Mphi even when sampling was extended to 31 days, an interval beyond the accepted half-time for peritoneal Mphi. Intraperitoneal injections of thioglycollate or Corynebacterium parvum elicited few or no monocyte-Mphi during respective intervals of 4 and 7 days. Elicitation with thioglycollate was attempted in tritiated thymidine-labeled mice 26 days after 89Sr. Four days later only a 2-fold increase in labeled peritoneal Mphi was found in the 89Sr-treated mice compared with a 150-fold increase in the controls. Studies of the ectoenzymes 5'-nucleotidase, alkaline phosphodiesterase I, and leucine aminopeptidase in such elicitation experiments suggested that the observed changes in activities reflected the direct stimulation of resident Mphi rather than monocyte immigration. Overall, the results indicate that treatment with 89Sr distinguishes two large populations of Mphi on the basis of their dependence on bone marrow. Mphi of inflammation reflect the monocytopenia and are severely and rapidly depleted by such treatment. The maintenance of resident type Mphi, on the other hand, appears to be independent of both the state of the bone marrow and the level of monocytes in the blood.

Animals↗
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↗
PubMedDate not supplied

Restricted expression of LUZP in neural lineage cells: a study in embryonic stem cells.

A novel protein LUZP with 3 leucine zipper motifs at its amino terminus is predominantly expressed in the adult brain. A modified gene targeting approach was employed in an attempt to establish in vitro and in vivo models in which Luzp is knock-out (KO) for phenotype assessment and a reporter gene lacZ is knock-in (KI) for tracing its expression. We report in this study the molecular cloning of the Luzp gene, its targeting vector construction and Luzp-KO/lacZ-KI embryonic stem (ES) clone selection. Since LUZP is also expressed in ES cells, the possibility of embryonic lethality cannot be excluded when attempting to establish Luzp-null mutant mice. We have therefore examined the development of homozygous Luzp-KO/lacZ-KI clones in nude mice. Tissue types derived from all three embryonic germ layers were observed in teratomas developed in nude mice. In situ X-gal staining further revealed restricted expression of LUZP in neural lineage cells.

Animals↗
PubMedDate not supplied

Effect of anti-hypertensive drug dose frequency on the clinic-home blood pressure difference in patients with stage 1 treated hypertension.

Clinic blood pressure (CBP) is generally used for diagnosis and treatment monitoring in hypertension, but target organ damage correlates more closely with home blood pressure (HBP). Eliminating the clinic-home blood pressure difference (CHBPD) would make conventional CBP a more accurate alternative to HBP. This prospective, randomized, open trial compared the effect of a once-daily versus a twice-daily regimen of anti-hypertensive therapy on CHBPD. After a 2-week wash-out period, 85 confirmed stage 1 hypertensive patients were randomized to receive 2 mg trichlormethiazide daily in one (40 subjects) or two (45 subjects) daily doses for 3 weeks. CBP and HBP measurements were taken during the third week of treatment and the CHBPD calculated. After treatment, the systolic and diastolic CHBPD values were significantly greater in the once-daily regimen than in the twice-daily regimen. Conventional CBP should not be used as an alternative to HBP for evaluating prognosis and monitoring anti-hypertensive therapy when using a once-daily regimen.

Adult↗