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Biomedical subjects

C J Chang

Publications and source records attributed to C J Chang.

At least 199 records · Page 11Linked to original sources
PubMed1993

[One year follow-up study of the recovery of adrenal insufficiency induced by formulated herb drugs].

Previous studies have found that taking formulated herb drugs may reduce the serum cortisol level which may result in an adrenal insufficiency. We suspect that this effect is induced by corticosteroids artificially mixed in formulated herb drugs. The objectives of this study were to determine the time course of serum cortisol and plasma ACTH (adrenocorticotropic hormone) levels, and whether pituitary-adrenal function recovers after quitting formulated herb drugs for a period of one year. Forty eight subjects with an initial serum cortisol level smaller than 10.7 micrograms/dL due to the intake of formulated herb drugs were recruited. They were tested for serum cortisol and plasma ACTH levels at 08:00 6, 9 and 12 months after quitting formulated herb drugs, respectively. The diagnosis of adrenal insufficiency was confirmed by an ACTH test at 9 months and 12 months after quitting the formulated herb drugs. The follow-up rates ranged from 63% to 71%. The 08:00 serum cortisol levels at the initial test, 6 months, 9 months, and 12 months were 4.4 +/- 0.5 micrograms/dL, 6.6 +/- 0.8 micrograms/dL, 6.6 +/- 0.7 micrograms/dL, 6.2 +/- 0.8 micrograms/dL, respectively, (interpersonal p = 0.0001, intrapersonal p = 0.0004, repeated measures ANOVA test.) The 08:00 plasma ACTH levels at the initial test, 6 months, 9 months and 12 months were 33.8 +/- 6.4 pg/mL, 67.6 +/- 16.8 pg/mL, 21.0 +/- 3.2 pg/mL, 16.3 +/- 2.2 pg/mL, respectively (interpersonal P = 0.0001, intrapersonal P = 0.0003, repeated measures ANOVA test.) The statistical significance was the same after logarithmic transformation of the ACTH levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1993

Oral health conditions among people visiting a medical center for health checkups.

The purpose of this study was to evaluate the oral health conditions of subjects in a southern Taiwan health checkup program. One half of the examinees were selected randomly for oral examination during a two-year period. There were 537 subjects, including 286 men and 251 women with mean ages of 49.7 +/- 13.5 years and 50.2 +/- 12.1 years, respectively. Oral examinations included periodontal condition and existence of dental caries. The periodontal treatment needs of all examinees were evaluated using the Community Periodontal Index of Treatment Needs system and the World Health Organization periodontal probe. Dental caries examination was performed by the visual-tactile method with a mouth mirror and explorer. No radiographs were taken. All clinical evaluations were performed by the first author, who has experience in all of the indices. The results showed that only 0.7% of the subjects had no need of periodontal treatment, 6.7% had bleeding after gentle probing, and 75.2% presented with calculus, overhanging restorations, or pockets of 4 or 5 mm. The remaining 17.3% had pocket depths of 6 mm or deeper. There was no statistically significant difference between males and females in periodontal treatment needs and the mean number of decayed teeth (D). According to this hospital-based observation, most of the people in the health checkup program were in need of periodontal treatment, including oral hygiene instruction, prophylaxis and root planing. Approximately one-fifth of the subjects needed complex periodontal treatment; there were no differences in the treatment needs of males and females.(ABSTRACT TRUNCATED AT 250 WORDS)

Academic Medical Centers↗
PubMed1993

The effect of shift system on sleep quality, sleep quantity, psychological disturbance, and family function of workers in Taiwan.

This study was designed to examine whether there were any differences in sleep quality and quantity between rotating shift workers and permanent day workers. The subjects of this study consisted of 419 rotating shift workers and 468 permanent day workers. The Chinese Health Questionnaire (CHQ-12) and Family APGAR Index were used to collect information concerning psychological disturbances and family dysfunctions. The results showed that, compared to the permanent day workers, sleep quality and quantity were poorer for the rotating shift workers. The rotating shift workers often had more psychological disturbances and family dysfunctions than permanent day workers.

Adult↗
PubMed1993

Antiproliferative and antimetastatic effects of gossypol on Dunning prostate cell-bearing Copenhagen rats.

Gossypol, a polyphenolic aldehyde naturally present in cottonseed, has long been recognized as a male contraceptive and recently as a potential anticancer agent. Our study used a rodent model to evaluate gossypol's potential for the treatment of human prostatic carcinoma. Two-month-old Copenhagen male rats received subcutaneous implants of a subpassage of MAT-LyLu prostatic cancer line, a highly metastatic, androgen-independent Dunning prostate tumor subline that specifically metastasizes to lymph nodes and lungs of recipients. After 2 weeks of gossypol treatment (0 or 12.5 mg/kg B.W./day S.C.) initiated immediately after transplantation, the rats were sacrificed and evaluated for prostate tumor growth and metastasis. Testosterone and gossypol levels in tumor tissue and various reproductive organs and serum potassium level were measured by radioimmunoassay (RIA), high pressure liquid chromatography (HPLC) and atomic emission spectroscopy (AES), respectively. Gossypol-treated rats exhibited weight reductions in developed MAT-LyLu prostate tumor mass and prostate of 24% (p < 0.05) and 31% (p < 0.05), respectively; whereas testicular and epididymal weights were not significantly affected. Few metastases (20%) were observed in either lymph nodes or lungs of gossypol-treated recipients. The control rats, however, had a much higher rate of lung (60%) and lymph node metastasis (40%). Testicular testosterone levels, as measured by RIA, were significantly lower in gossypol-treated rats than in controls (p < 0.05), but serum testosterone levels were not different. Extractable gossypol content in the prostate tumor, as measured by HPLC, reached 19.67 ng/gm and was 1.28 times higher than in liver, 1.98 times higher than in testes, but was 3.3% of that in prostate. Moreover, serum had the highest gossypol content (10.7 micrograms/ml). Serum potassium levels, as measured by AES, were significantly higher in gossypol-treated individuals than controls (p < 0.05). Our results indicate for the first time that gossypol has antiproliferative and antimetastatic effects on MAT-LyLu prostate cancer cells and can be explored as a potential therapeutic agent for androgen-independent human prostatic carcinoma.

Androgens↗
PubMed1992

Prevalence and risk factors of diabetic retinopathy among noninsulin-dependent diabetic subjects.

In a population-based study in Taiwan, 11,478 subjects aged 40 years or older were screened for diabetes in one urban and five rural areas. Among the 715 subjects proven to have diabetes, 527 subjects underwent ophthalmoscopy. Diabetic retinopathy was present in 184 of the 527 subjects (35.0%), including background diabetic retinopathy in 157 subjects (30.0%), preproliferative diabetic retinopathy in 15 subjects (2.8%), and proliferative diabetic retinopathy in 12 subjects (2.2%). Diabetic retinopathy was correlated with the duration of diabetes and age at onset of diabetes, type of diabetes treatment, higher serum creatinine levels, and lower serum cholesterol levels. Several other factors, including gender, age, residential area, family income, educational level, control and family history of diabetes, body mass index, physical activity, exercise, cigarette smoking, stroke, ischemic heart disease, leg vessel disease, hypertension, and proteinuria, had no significant association with retinopathy. By multiple logistic regression analysis, duration of diabetes was the most important risk factor related to retinopathy. Diabetic subjects treated with insulin had a higher risk of developing retinopathy than those treated with dietary control (relative risk, 1.57; .05 < P < .10). The univariate analysis disclosed that proliferative diabetic retinopathy was related to older age at examination, older age at onset of diabetes, type of diabetes treatment, and presence of leg vessel disease. Insulin-treated diabetic subjects also had a higher risk of proliferative diabetic retinopathy than patients in whom diabetes was controlled by diet, with a relative risk of 2.51 (.05 < P < .10) in the multiple logistic regression analysis.

Adult↗
PubMed1992

Rapid screening for taxanes by tandem mass spectrometry.

A highly specific and sensitive method is described for determining taxol, cephalomannine, and baccatin III in crude plant extracts. Radical anions of the taxanes are formed by desorption chemical ionization, and a parent tandem mass spectrometric scan is used to recognize these compounds by their characteristic dissociations. The limit of detection of the individual taxanes in typical plant matrices is less than 500 pg when all three species are screened simultaneously. Because of the sensitivity of the method, extraction times can be shortened to 30 min and crude extracts can be examined at the rate of 6/h. Detection of all three taxanes extracted from a single Taxus cuspidata needle in a combined extraction/analysis time of less than 1 h is demonstrated.

Alkaloids↗
PubMed1992

Transfer of 3H-gossypol to neonatal rats via milk of nursing dams.

Gossypol is a naturally occurring toxin with potent antifertility action in both males and females. Transfer of gossypol via milk from lactating mother to neonates has not been documented. One theory for the lack of such a finding is that gossypol, once tightly bound to milk proteins, is not extractable by conventional extraction methods for HPLC analysis. This study was designed to examine the possibility and dynamics of transmammary transfer of radioactively-labelled gossypol to neonates through nursing. Nursing rats were dosed with fifty microCi of 3H-gossypol in 0.5 ml of dimethyl sulfoxide via oral intubation on Day 10 post-partum. Six hours after treatment, significant amounts of 3H-gossypol were detected in the coagulated milk collected from the stomachs of the neonates as well as in the blood, liver, lung, spleen and a number of other tissues of these pups. While most neonatal tissues showed a steady decline in 3H-gossypol retention over time regardless of neonatal gender, adrenal glands and gonads preferentially accumulated 3H-gossypol in a time- and sex-dependent manner during the 24-hour sampling period. The results demonstrate that 3H-gossypol is transferred via milk from the nursing dams to their neonates. Thus, the gossypol content of milk presents a conceivable threat to neonatal health, especially to the normal function of steroidogenic organs.

Animals↗
PubMed1992

Biologically active gamma-lactones and methylketoalkenes from Lindera benzoin.

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of ripe berries from Lindera benzoin led to the isolation of three new C21 alkane-alkene gamma-lactones designated isolinderanolide, isolinderenolide, and linderanolide as well as the known series of C17 and C19 obtusilactones (isoobtusilactone A, obtusilactone A, isoobtusilactone, and obtusilactone) previously isolated from Lindera obtusiloba. The novel (6Z,9Z,12Z)-pentadecatrien-2-one, the known (6Z,9Z)-pentadecadien-2-one, and the known (+)-(Z)-nerolidol were also isolated as bioactive compounds. The structural elucidation and biological activities of these compounds are reported.

Animals↗
PubMed1992

Emodin, a protein tyrosine kinase inhibitor from Polygonum cuspidatum.

Bioassay-directed fractionation of a Chinese medicinal plant, Polygonum cuspidatum (Polygonaceae), has led to the discovery of an anthraquinone, emodin [1], as a strong inhibitor of a protein tyrosine kinase (p56lck) partially purified from bovine thymus. Comparison of the IC50 values of emodin for protein tyrosine kinase inhibitory activity with physcion [2] and emodin-O8-D-glucoside [3], also isolated from the same plant, reveal the importance of the hydroxyl groups at C-6 and C-8 for the observed activity.

Animals↗
PubMed1992

Protein-tyrosine kinase inhibition: mechanism-based discovery of antitumor agents.

Protein-tyrosine kinases (PTKs) have been shown to induce the cascade of altered cell parameters characteristic of transformed cells. This proposition provides an important rationale for the discovery of potential antitumor agents from natural sources on the basis of inhibition of PTK activity. Numerous naturally occurring and synthetic analogues of PTK inhibitors were systematically evaluated in this review based on their structure-activity relationships and potential antitumor efficacy.

Animals↗
PubMed1992

Structure and expression of mouse alpha 1-acid glycoprotein gene-3 (AGP-3).

The genome of Mus domesticus has multiple genes of the alpha 1-acid glycoprotein (AGP). Two cDNA clones were identified corresponding to AGP-1 and AGP-2. Moreover, two alleles of AGP-1 exist in inbred mice. The genomic DNA of the AGP-2 gene has been cloned and studied. Here we report the genomic organization of three M. domesticus AGP genes, the sequence analysis of the AGP-3 genomic DNA, and the expression of the AGP-3 gene. The major structural differences between AGP-2 and AGP-3 genes are located in introns 1 and 5. The low level of AGP-3 mRNA can be detected by the polymerase chain reaction (PCR). The molecular basis of the low level expression of AGP-3 and the possible classification of AGP-3 as a pseudogene are discussed.

Amino Acid Sequence↗
PubMed1992

Influence of central obesity and obesity level on the prevalence of NIDDM and impaired glucose tolerance.

The purpose of this study was to determine the association of the prevalence of non-insulin-dependent diabetes (NIDDM) with central obesity, obesity, and family history of diabetes. This survey consisted of 1590 subjects (646 men, 944 women) aged 30 years or more from the Sun-Ming district of Kaoshiung city. Glucose tolerance status was ascertained by both medical history and a 75-g oral glucose tolerance test according to World Health Organization criteria. In men and women with central obesity (WHR > or = 0.92 in men and > or = 0.85 in women) or obesity (BMI > or = 27.6 kg/m2 in men and > or = 28.3 kg/m2 in women) (WHR: waist-hip ratio; BMI: body mass index), the prevalence of impaired glucose tolerance (IGT) and diabetes was significantly higher, except the prevalence of diabetes in both sexes with obesity and the prevalence of IGT in women with central obesity were not statistically different, as compared with nonobese subjects. The prevalence of diabetes in men significantly increased from the first quartile to the fourth quartile of BMI and the waist-hip ratio (WHR) (4.48% to 9.21% in BMI, 3.67% to 13.61% in WHR), while the prevalence in women also significantly increased from the first to fourth quartile (2.45% to 11.76% in BMI, 2.04% to 13.49% in WHR). Multiple logistic regression analyses revealed similar increase in the prevalence of diabetes among both men and women for every 1 kg/m2 increase in BMI and every 0.05 increase in WHR (1.07-fold and 1.09-fold in BMI, 1.34-fold and 1.32-fold in WHR, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Morphometric analysis of renal cortex changes induced by diethylstilbestrol (DES) in Syrian hamsters.

Estrogen-induced renal adenocarcinoma usually can be readily detected in castrated hamsters after 9 to 12 months of DES treatment. In the present study, we examined the morphological characteristics of the renal cortices of castrated hamsters that had received 3 months of DES treatment in order to describe early histological evidence of carcinogenesis induction. Twelve Syrian Golden hamsters, 8 to 9 weeks of age, were first castrated and then subjected to either subpannicular implantation of a 20 mg DES pellet (experiment group), or sham operation (controls). Morphological and 2-D morphometric evaluations were conducted sequentially on kidney histological sections. Numbers (N's) or area fractions (AF's) of renal components in the juxta-medullary junction of each kidney section were processed for morphometric evaluation. The DES treatment caused a 15% increase in kidney weight, but not body weight. Dysplastic foci associated with hyperplastic tubules were present in 67% of the left kidneys or 17% of the right kidneys of hamsters in the test group, but were absent in kidneys of controls. DES treatment decreased glomeruli N by 33% and increased the vasculature AF by 169% per examination field. DES also increased AF's of glomeruli, proximal tubules, distal tubules, and vasculature by 17, 81, 53 and 346% per nephron, respectively. Our results showed that, after the first three months of DES-treatment, hamster kidneys developed dysplastic foci and their masses were greater than controls. Increased renal components in the juxta-medullary junction region included glomeruli, tubules, and vasculature. The dysplastic foci may be sites of subsequent malignancies, whereas the increased renal mass might be a result of functional adaptation/expression to exogenous estrogen which might contribute to the carcinogenic process.

Animals↗
PubMed1991

Chemical modification of DNA: quantitation of O6-methyldeoxyguanosine by tandem mass spectrometry.

Methodology is described which allows quantitation of O6-methyldeoxyguanosine generated as a product of in vitro methylation of calf thymus DNA by methyl methanesulfonate (MeMS). Quantitative precision of 10% is achieved on samples of 10(-11)-10(-12) mol generated in 0.02% yield (expressed as O6-methyldeoxyguanosine versus deoxyguanosine) when DNA is treated with the weak carcinogen MeMS. These results show the potential application of this method to the analysis of DNA chemical modifications at the low levels that are relevant to the induction of biological effects of many alkylating agents. The methodology utilizes enzymatic degradation, reverse-phase chromatography and finally analysis by tandem mass spectrometry using desorption chemical ionization. Multiple reaction monitoring was used to increase sensitivity and the CD3-labeled nucleoside was used as an internal standard for quantification.

Chromatography, High Pressure Liquid↗
PubMed1991

Increased collagen gene expression in vascular smooth muscle cells cultured in serum or isoleucine deprived medium.

The relationship between type I and type III collagen gene expression and the growth state of cultured bovine vascular smooth muscle cells has been investigated. Growth was modulated by incubation of subconfluent cultures of smooth muscle cells in media containing concentrations of fetal calf serum ranging from 10% to 0.5%. As the serum concentration was lowered, the doubling time increased from 17 hours to 70 hours, and collagen mRNA levels increased as judged by Northern blot analysis. The levels of induction were 5- to 15-fold for alpha 1(I), 2- to 3-fold for alpha 2(I), and 4- to 7-fold for alpha 1(III). Metabolic cell labelling with precursor amino acids indicated that type I and type III procollagen synthesis was elevated approximately 2-fold as growth slowed. A similar 2-fold increase occurred upon translation of isolated RNAs in a rabbit reticulocyte cell-free system. Nuclear run-on analysis indicated that increased collagen transcription can account for part of the increase in mRNA levels following incubation in lowered fetal calf serum. To further examine the influence of proliferation on collagen gene expression, smooth muscle cells were cultured in isoleucine-free medium, which resulted in quiescence within 36 hours. Induction of collagen mRNA levels was observed within 24 hours of incubation in isoleucine-free medium. Thus, collagen gene expression increases as the growth of vascular smooth muscle cells is slowed by either deprivation of growth factors or essential amino acids. Regulation is mediated at several sites, including gene transcription and mRNA translation, and possibly post-transcriptional steps.

Animals↗
PubMed1990

Gigantecin: a novel antimitotic and cytotoxic acetogenin, with nonadjacent tetrahydrofuran rings, from Goniothalamus giganteus (Annonaceae).

Gigantecin (I), a novel tetrahydroxy-di-tetrahydrofuran fatty acid gamma-lactone (acetogenin), was isolated from an ethanolic extract of the stem bark of Goniothalamus giganteus Hook. f., Thomas (Annonaceae), by means of activity-directed fractionation (brine shrimp lethality test). This new compound is extremely cytotoxic to human tumor cells, inhibits crown gall tumors on potato discs, and is active in an assay designed to detect antimitotic agents (9 ASK).

Animals↗