Biomedical subjects

J J Chang

Publications and source records attributed to J J Chang.

At least 55 records · Page 3Linked to original sources

PubMed1993

Hypolipidemic effects of 6-amino-2-mercapto-5-methylpyrimidine-4-carboxylic acid in rats and tissue culture cells.

6-Amino-2-mercapto-5-methylpyrimidine-4-carboxylic acid (AMMPCA) was found to be a potent hypolipidemic agent at oral doses of 10 and 20 mg/kg/day in rodents. This agent was observed to affect de novo lipid synthesizing enzyme activities in a manner that resulted in lower lipid levels in tissues including the aorta wall. Very low density lipoprotein and low density lipoprotein cholesterol levels were reduced, whereas high density lipoprotein cholesterol levels were significantly increased. AMMPCA interfered with low density receptor activity, suggesting that the drug blocked lipid uptake by peripheral tissue while stimulating binding of lipid to the high density lipoprotein receptor, which should accelerate lipid clearance from the tissues and blood. A second mode of action of the drug is enhanced biliary excretion of lipids, but there was no evidence of a lithogenic effect. Acute toxicity studies in rodents support the fact that AMMPCA is safe in its therapeutic dose range.

Animals↗

PubMed1993

Antitumor agents, 138. Rotenoids and isoflavones as cytotoxic constitutents from Amorpha fruticosa.

Eight cytotoxic compounds have been isolated from the CHCl3 extract of Amorpha fruticosa. One compound, 6'-O-D-beta-glucopyranosyldalpanol [10], is a new cytotoxic rotenoid. Another known rotenoid, 12 alpha beta-hydroxyamorphigenin [6], was first shown to exhibit extremely potent cytotoxicity (ED50 < 0.001 microgram/ml) in six neoplastic cell lines. In addition to these compounds, three isoflavones (afrormosin [1], 7,2',4', 5'-tetramethoxyisoflavone [2], 8-methylretusin [3]) and five rotenoids (amorphispironone [4], amorphigenin [5], dalpanol [7], 12a beta-hydroxydalpanol [8], and tephrosin [9]) were isolated. Compound 8 was isolated for the first time as a natural product from this plant. The structures of these compounds were established on the basis of spectral data; some were further confirmed by X-ray crystallographic analysis.

Antineoplastic Agents, Phytogenic↗

PubMed1993

Antitumor agents, 145. Cytotoxic asprellic acids A and C and asprellic acid B. new p-coumaroyl triterpenes, from Ilex asprella.

Three new p-coumaroyl triterpenes, asprellic acids A [1], B [2], and C [3], were isolated from the EtOH extract of dried leaves of Ilex asprella. The structures for 1-3 have been established as 3,27-di-O-trans-p-coumaroyl [1], 3-O-trans-p-coumaroyl-27-O-cis-p-coumaroyl- [2], and 3-O-cis-p-coumaroyl-27-O-trans-p-coumaroyl- [3] 3 beta,27-dihydroxyolean-12-en-28-oic acid, respectively, by spectral and chemical examinations. Asprellic acid A [1] exhibited potent cytotoxicity against the RPMI-7951 cell line with an ED50 value of 0.62 micrograms/ml, while the cytotoxicity of asprellic acid C [3] against RPMI-7951 was marginal (ED50 5.5 micrograms/ml). Compounds 1 and 3 also showed cytotoxicity against KB cells with ED50 values of 3.75 and 2.86 micrograms/ml, respectively. Asprellic acid B [2] did not show cytotoxicity (> 10 micrograms/ml) against KB or RPMI-7951 cell lines.

Adenocarcinoma↗

PubMed1993

[A comparison of ankle fixation between two kinds of low-temperature plastic anterior ankle foot orthoses].

The low-temperature ankle foot orthosis (AFO) was designed in the anterior leaf type, called anterior AFO, to meet the need of indoor barefoot walking. It could be easily molded and remolded to fit the foot, as well as to adjust the position of the foot and ankle. Two kinds of low-temperature plastic anterior ankle foot orthoses, anterior encased and anterior direct molding ankle foot orthoses, were compared to analyze the effectiveness of ankle fixation in plantar flexion and inversion. Force was applied to each of the anterior AFOs at the anterior-middle and anterior-lateral sides to simulate the movement of ankle plantar flexion and inversion. At the same time, the deformation in plantar flexion and inversion of both anterior AFOs were recorded to analyze the relationship between force and the deformed angle. The results showed that plantar flexion deformed angles of the anterior direct molding AFO were 2.6 times more flexible than anterior encased AFO. The ankle inversion deformed angles of the anterior direct molding AFO were 3 times more flexible than the anterior encased AFO in inversion. These results support our belief that anterior encased AFO is more effective in controlling ankle plantar flexion and inversion than anterior direct molding AFO, especially for severe spastic hemiplegia in gait correction.

Ankle Joint↗

PubMed1993

[Jiangzhi koufu ye in the treatment of essential hyperlipemia].

The effect of Jiangzhi Koufu Ye (JZKFY) for serum lipid was verified. 333 patients were treated with JZKFY as treated group, while those with vitamin E as control. It was found that JZKFY was able to lower TC, TG, TC-HDL-ch/HDL-ch and raise HDL-ch very significantly (P < 0.001) after 14 weeks and the effect were maintained at least 4 weeks. The marked effective and the total effective rate were 59% and 92% respectively. Except for HDL-ch, all other indexes were better than the control. No obvious side effects were found.

Aged↗

PubMed1993

[Comparison of various patterns of chopstick use and functional performance].

Three hundred and ninety-seven normal adult subjects were tested in order to investigate the prevalences of various patterns of chopstick-use. Manipulation speed was also compared. According to the movement of the fingers, finger positions and contact areas, we can divide the various chopstick-use patterns into 3 basic patterns with 13 variations. Prevalences of the 3 basic patterns were palmar prehension (68.5%), lateral prehension (14.2%), and dynamic palmar prehension (17.3%). There was a statistically significant difference in manipulation speed among the 3 basic patterns. The influence of sex and age on manipulation speed was also analyzed for each of the 3 basic chopstick-use patterns. The results of this study will serve as a reference for occupational therapists in the evaluation and training for eating activities.

Adult↗

PubMed1992

Antitumor agents. 134. New shiraiachrome-A- and calphostin-C-related perylene derivatives as cytotoxic and antiviral agents and inhibitors of protein kinase C.

Shiraiachrome-A and -B have been isolated from the mycelium of the Chinese bamboo fungus Shiraia bambusicola as the cytotoxic principles. A series of new perylene derivatives (7-27) related to Shiraiachrome-A and -B as well as Calphostin-C have been synthesized and evaluated for their cytotoxicity, antiviral activity, and inhibitory activity against protein kinase C. The results indicated that 11 and 12 are potent cytotoxic agents against HCT-8, RPMI-7951, and TE-671 solid tumor cells, whereas 24 and 26 demonstrated strong antiviral activity against HSV-1 and HSV-2. Compound 10 is an inhibitor of protein kinase C.

Animals↗

PubMed1992

Monosomy 21 in two patients with acute nonlymphocytic leukemia.

Among 50 cases of acute nonlymphocytic leukemia (ANLL) with available cytogenetic data seen in our section since May 1988, two were found to carry a monosomy 21 abnormality which has been rarely reported in hematologic malignancies. The first case is a 58-year-old male with a diagnosis of AML, FAB M2, who died of refractory leukemia 9 months later. The other case is a 59-year-old female with AML, FAB M2. Complete remission was achieved initially but she died of sepsis 3 months later with no evidence of leukemic relapse. Monosomy 21 is not yet recognized as a nonrandom cytogenetic abnormality in ANLL, whereas its unusual predilection in AML, especially the FAB M2 or M4 categories, as noted in our study and others' reports, have raised this possibility. Further studies and the accumulation of new cases are needed in the hope of defining it as a subtype of ANLL.

Chromosomes, Human, Pair 21↗

PubMed1992

2,4,5-trichlorophenoxyacetic acid influence on 2,6-dinitrotoluene-induced urine genotoxicity in Fischer 344 rats: effect on gastrointestinal microflora and enzyme activity.

2,4,5-Trichlorophenoxyacetic acid (2,4,5-T) and 2,6-dinitrotoluene (2,6-DNT) are hazardous chemicals that have potential harmful effects. 2,6-DNT is recognized as a hepatotoxicant while 2,4,5-T, a component of Agent Orange, is also suspect. 2,6-DNT requires both oxidative and reductive metabolism to elicit genotoxic effects. To determine what effect 2,4,5-T had on 2,6-DNT metabolism, intestinal enzymes, microbial populations, and urine mutagenicity were examined during 2,4,5-T treatment. Weanling Fischer 344 male rats were treated daily with 54.4 mg/kg 2,4,5-T by gavage for 4 weeks. One, two, and four weeks after the initial 2,4,5-T dose, rats were administered (po) 2,6-DNT (75 mg/kg) and urine was collected for 24 hr in metabolism cages. Azo reductase, nitroreductase, beta-glucuronidase, dechlorinase, and dehydrochlorinase activities were examined concurrently. Treatment of rats for 1 week reduced the transformation of 2,6-DNT to mutagenic urinary metabolites. This was accompanied by a decrease in the fecal anaerobic microorganisms. The elimination of Lactobacillus fermentum from the small intestine and cecum of treated animals accompanied a significant increase in oxygen-tolerant lactobacilli and other unidentified aerobic microorganisms. However, there were no significant alterations in the intestinal enzyme activities examined. By 2 weeks of 2,4,5-T treatment, microbiota and urine genotoxicity returned to the levels observed in control animals. This trend continued for the duration of the experiment. After 2 weeks, while cecal nitroreductase and azo reductase activities increased, small intestinal beta-glucuronidase activity decreased. By 4 weeks, treated and untreated animal intestinal enzyme activities were indistinguishable.(ABSTRACT TRUNCATED AT 250 WORDS)

2,4,5-Trichlorophenoxyacetic Acid↗

PubMed1992

Antitumor agents, 129. Tannins and related compounds as selective cytotoxic agents.

Fifty-seven tannins and related compounds, including gallotannins, ellagitannins, and condensed and complex tannins, were evaluated for their cytotoxicities against human tumor cell lines, including malignant melanoma, lung carcinoma, ileocecal adenocarcinoma, epidermoid carcinoma, malignant melanoma, and medulloblastoma cell lines. Among them, chebulagic acid [1], geraniin [2], sanguiin H-11 [3], 4,5-di-O-galloylquinic acid [12], 1,3,4,5-tetra-O-galloylquinic acid [15], 1(beta)-O-galloylpedunculagin [24], furosin [29], castalagin [38], sanguiin H-2 [34], vescalagin [39], grandinin [40], phyllyraeoidin A [42], (-)-epicatechin 3-O-gallate [50], cinnamtannin B2 [55], and acutissimin A [56] exhibited moderate selective cytotoxicity against PRMI-7951 melanoma cells with ED50 values in the range of 0.1-0.8 microgram/ml. Selective cytotoxicities against the melanoma cells were also observed for strictinin [22], pedunculagin [23], eugeniin [25], elaeocarpusin [28], punicacortein C [37], casuarinin [41], sanguiin H-6 [43], procyanidin B-2 3,3'-di-O-gallate [51], procyanidin C-1 3,3',3"-tri-O-gallate [52], and cinnamtannin B1 [54] with ED50 values of 1-4 micrograms/ml. All of the tannins were found to be inactive (greater than 10 micrograms/ml) against lung carcinoma (A-549), ileocecal adenocarcinoma (HCT-8), epidermoid carcinoma of nasopharnyx (KB), and medulloblastoma (TE-671) tumor cells.

Antineoplastic Agents, Phytogenic↗

PubMed1992

Antitumor agents, 135. Structure and stereochemistry of polacandrin, a new cytotoxic triterpene from Polanisia dodecandra.

A new dammarane triterpene, polacandrin [1], has been isolated from Polanisia dodecandra. The structure of 1 was established as 1 beta, 3 alpha, 12 beta, 25-tetrahydroxy-20(S),24(S)-epoxydammarane by chemical and spectroscopic methods, which included the concerted application of a number of 2D nmr techniques that involved 1H-1H COSY, HETCOR, NOESY, and long-range HETCOR. Single-crystal X-ray analysis of polacandrin pentahydrate verified the complete structure and stereochemistry. Polacandrin showed potent cytotoxicities against KB (ED50 = 0.60 microgram/ml), P-388 (ED50 = 0.90 microgram/ml), and RPMI-7951 (ED50 = 0.62 microgram/ml) tumor cells.

Animals↗

PubMed1992

The effects on lipid metabolism of 4-phenyl-5,5-dicarbethoxy-2-pyrrolidenone in Sprague Dawley rats.

4-Phenyl-5,5-dicarbethoxy-2-pyrrolidenone [XIV] treatment in Sprague Dawley rats caused significant reduction of serum cholesterol and triglyceride levels with reduction of VLDL and LDL cholesterol levels. The compound significantly reduced regulatory enzyme activities, e.g. ATP dependent citrate lyase, HMG CoA reductase, acyl CoA cholesterol acyl transferase, cholesterol-7-alpha-hydroxylase, sn-glycerol-3-phosphate acyl transferase and phosphatidylate phosphohydrolase. In tissue cultured cells, the compound suppressed LDL receptor activity and degradation, and elevated HDL receptor activity and HDL degradation. Rat bile cholesterol and phospholipids were elevated; however, overall bile acids were reduced. In situ loop studies suggest that the agent interfered with interhepatic reabsorption of cholesterol and cholic acids. At the therapeutic dose of compound XIV, no deleterious effects were demonstrated in mice.

Animals↗

PubMed1991

Cytotoxic principles of Securinega virosa: virosecurinine and viroallosecurinine and related derivatives.

Virosecurinine (1) and viroallosecurinine (2) were isolated as two cytotoxic alkaloids from the leaves of Securinega virosa. A comparison of the cytotoxicity of 1 and several of its derivatives indicates that an alpha,beta- and a gamma,delta-unsaturated lactone located in a strained ring system, such as rings -B, -C, and -D of 1, is structurally required for significant cytotoxicity.

Alkaloids↗

PubMed1991

[The relationship between functional recovery one year after a stroke, and related factors].

This study examines the factors affecting functional performance of 40 hemiplegic subjects in their homes following discharge from the hospital. All subjects suffered a cerebral vascular accident at least one year prior to this research period. Barthel Index was used to assess subjects' self-reported functional level in activities of daily living (ADL). A backward elimination of stepwise regression analysis was performed to ascertain the predictive value of the variables in determining functional performance one year after the onset of a stroke. These variables are factors related to the initial onset and those affecting the patient's functional status at home. The results revealed that subjects who had a shorter length of stay in the hospital, scored a higher on the Barthel Index (p less than 0.05). It also demonstrated that subjects who were more satisfied with their current subjective health status, had a higher Barthel Index score.

Activities of Daily Living↗

PubMed1990

New phenomena linking depth and luminance in stereoscopic motion.

A novel random-dot stereogram (RDS) was used to study stereoscopic motion. For this RDS stimulus, the direction of luminance motion and the direction of the moving cyclopean pattern can be independently controlled. The perceived cyclopean motion was examined under five different conditions, in which the cyclopean pattern was moving either up or down, the luminant dots were: (1) moving in the cyclopean direction; (2) moving opposite to the cyclopean direction; (3) moving orthogonal to the cyclopean direction, (4) stationary; or (5) dynamic (dots uncorrelated in successive frames). The study showed that luminance direction dominated cyclopean direction and that smooth and coherent cyclopean motion is seen only if luminance motion is present. The results suggest that stereoscopic motion is processed by interactions between separate binocular disparity units and luminance motion units, and not by a single binocular motion system, in which binocular units are tuned to both disparity and direction of motion.

Depth Perception↗

PubMed1990

Renal, hepatic, cardiac and thymic acute toxicity afforded by bis(helenalinyl)malonate in BDF1 mice.

Bis(helenalinyl)malonate [BHM], a pharmacologically active sesquiterpene lactone potentially useful as an antineoplastic agent, proved to be less toxic than its parent compound, helenalin. Its LD50 in BDF1 mice, i.p. was more than twice that of helenalin. Its lower toxicity allowed a higher therapeutic dose (15 mg/kg/day vs. 8 mg/kg/day for helenalin) which, in turn, afforded a greater T/C% (261 vs. 161). When BHM was employed at its therapeutic dose of 15 mg/kg/day, no marked toxicity was evident after three daily doses. However, continuation of treatment at this level led to both kidney and liver toxicity as measured by clinical chemistry parameters. Histological lesions in the thymus and kidney were demonstrated within 48 h at 25 mg/kg as a single dose. Apparently the toxicity was delayed with BHM but accumulated over time. Transient cardiotoxicity occurred with the drug and the agent was suspected of causing intestinal blockage.

Animals↗

PubMed1990

Effect of lindane on nitroreductase and dechlorinase enzyme activity in the gastrointestinal tract.

A previously reported acceleration of parathion metabolism in the gastrointestinal (GI) tract of lindane-pretreated rats could have been due to either a prolonged residence time of parathion or increased GI nitroreductase activity or both. Thus to determine the effect on GI nitroreductase and dechlorinase activity, 20 mg/kg lindane or 535 mg/kg neomycin were administered daily, by gavage, to weanling F-344 rats. Enzyme activity in the small intestine and cecum were assayed after 2 weeks and 5 weeks of treatment. Neomycin treatment inhibited the activity of both enzymes in the cecum but had no significant effect on enzyme activity in the small intestine, suggesting the presence of mucosal nitroreductase and dechlorinase in the small intestine. In contrast, lindane, which had no effect on enzyme activity in the cecum, significantly increased nitroreductase activity in the small intestine after treatment for 5 weeks. This increased nitroreductase may account for the previously reported lindane-parathion interaction and could influence the metabolism, toxicity, and risk assessment of many other environmental nitro-compounds that become toxic, mutagenic or carcinogenic upon reduction of their nitro-groups.

Animals↗

PubMed1990

The cytotoxic principles of Pseudolarix kaempferi: pseudolaric acid-A and -B and related derivatives.

Pseudolaric acid-A and -B, the novel diterpene acids isolated from Pseudolarix kaempferi, and their related derivatives have been tested for cytotoxicity against KB, A-549, HCT-8, P-388, and L-1210 tumor cells. The results showed that pseudolaric acid-A and -B demonstrated potent cytotoxicity. The selectivity of pseudolaric acid-A and -B which inhibit the growth of particular cell types within the disease-oriented human cancer cell line panels is discussed.

Animals↗