Cardiac glucose utilization during the fed-to-starved transition.
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Animals↗
Biomedical subjects
Y L Liu
Publications and source records attributed to Y L Liu.
Skeletal muscle glucose disposal after re-feeding in the hyperthyroid rat.
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Animals↗
Growth factor receptors and the progression of breast cancer.
Interference with autocrine or paracrine loops offers a potential means of treatment of tumors which currently lack effective therapies. Hormonally responsive breast cancers generally respond to treatment with antiestrogens but a frequent occurrence is an outgrowth of populations of tumor cells that are no longer dependent on estrogen for growth. If the acquisition of the ability to constitutively express growth factors or growth factor receptors is associated with this form of tumor progression, identification of the growth factors and their receptors having the capability of reducing the dependence on estrogen for growth is an important first step in the design of strategies aimed at interfering with their function. Experimental systems employing transfection with eukaryotic expression vectors are described that are designed to test the hypothesis that overexpression of epidermal growth factor receptor or the related protein C-ERB-B2 may confer an increased growth rate under conditions of estrogen deprivation. The transfected cells are also being used to explore the molecular mechanisms underlying the regulation of epidermal growth factor receptor expression by estrogen.
Animals↗
Translation initiation factors induce DNA synthesis and transform NIH 3T3 cells.
Several polypeptide factors that are essential for the initiation of protein synthesis bind to eukaryotic mRNAs and facilitate the formation of ribosome initiation complexes. Purified mRNA-binding translation initiation factors were microinjected into quiescent NIH 3T3 cells to study the possible growth-promoting role of these factors in living cells. We report that recombinant eIF-4E and rabbit reticulocyte eIF-4F induce a dose-dependent increase of DNA synthesis and morphologically transform NIH 3T3 cells. These results suggest that polypeptides involved in activating the rate-limiting step of protein synthesis (initiation complex formation) can be mitogenic and oncogenic when overexpressed in a cell by direct injection. Thus, eIF-4E and eIF-4F represent a class of proto-oncogenic proteins that is cytoplasmic, is involved in protein synthesis initiation, and is distinct from the proto-oncogenes that have been identified previously.
Animals↗
[HPLC analysis of flavonoids in the root of six Glycyrrhiza species].
Ten flavonoids isolated from six species of Glycyrrhiza root were analysed by reversed phase HPLC. A column packed with Partisil 5 ODS-3 and gradient elution by using different percentage of methanol (B) in water-glacial acetic acid (97:3 V/V) (A) were used to separate licochalcone A, isoschaftoside, schaftoside, liquiritin, isoviolanthin, violanthin, ononin, isoliquiritin, 4', 7-dihydroxyflavone and licoflavone A. Nine Glycyrrhiza samples of six species were analysed to determine their composition and content of the flavonoids. The results showed that the composition and content of the flavonoids of different Glycyrrhiza species were different as well as the same species but collected in different places.
Chromatography, High Pressure Liquid↗
[Structure of swertiamacroside from Swertia macrosperma C.B. Clark].
From the air-dried whole plant of SwerBia macrosperma C. B. Clark four compounds I-IV were isolated. One of them is a new caffeic acid disaccharide ester. Its structure was elucidated as 1-O-trans-caffeoyl-6-O-alpha-L-rhamnopyranosyl-beta-D-glucopyranos ide, i. e. trans caffeic acid-1-O-rutinose ester on the basis of chemical and spectroscopic analysis, and named swertiamacroside (I). The other three known compounds were identified as mangiferin (II), bellidifodin (III) and bellidifodin-8-O-beta-D-glucopyranoside (IV).
Caffeic Acids↗
[Studies on the structure of scuteamoenin from the root of Scutellaria amoena].
In containing our studies on the flavonoids from Scutellaria amoena C.H. Wright, a new flavanone (I) and six known compounds (II-VII) were isolated from the roots of this plant. On the basis of spectroscopic analysis (UV, 1H NMR, 13C NMR, MS and CD) and chemical evidence, the structure of the new compound was elucidated as (2S) -2',5,6'-trihydroxy-7-methoxyflavanone (I) and named scuteamoenin, the other six known compounds were identified as (2R,3R) -3,5,7-trihydroxyflavanone (II), 2',3,5,6,7-pentahydroxyflavone (III), 2',5,7-trihydroxy-6-methoxyflavone (IV), skullcaflavone II (V), chrysin (VI) and beta-sitosterol (VII) respectively. Compounds II-VII were obtained from this plant for the first time.
Drugs, Chinese Herbal↗
Health insurance coverage of Minnesota farm families.
This study of 1,482 farm families assesses the extent and cost of health insurance coverage among Minnesota farm families and finds that these families are buying less insurance coverage than urban families, while paying a higher proportion of their income for these premiums. More than three-fourths of the farm families surveyed buy their health insurance plan themselves and pay for it out of pocket. Their plans, on average, are slightly less expensive than employer-provided plans in urban areas, but they provide much less coverage and have more copayments and deductibles. Unlike their urban counterparts, who often choose health plans for convenience of location or freedom to choose physicians, farmers generally choose plans on the basis of costs and services provided. About 7 percent of farm families are without insurance, and many others are underinsured because they cannot afford to purchase an adequate plan.
Cost Control↗
Time courses of the responses of pyruvate dehydrogenase activities to short-term starvation in diaphragm and selected skeletal muscles of the rat.
In the fed state, the percentages of the pyruvate dehydrogenase complex (PDH) in the active form (PDHa) in diaphragm and a selection of skeletal muscles (adductor longus, soleus, extensor digitorum longus, tibialis anterior, gastrocnemius) ranged from 8% (soleus) to 38% (gastrocnemius). Major decreases in PDHa activities in all of these muscles were observed after 15 h of starvation, by which time activities were less than 40% of the fed values. In general, the response to starvation was observed more rapidly in muscles of high oxidative capacity. The patterns of changes in skeletal-muscle PDH activities during the fed-to-starved transition are discussed in relation to changes in lipid-fuel supply and oxidation.
Animals↗
[Synthesis of acylates of niridazole and its analogs as schistosomicides].
In order to decrease the toxicity and enhance the curative effect of niridazole against Schistosomiasis japonica, a series of acylates of niridazole has been prepared through acylation of niridazole, 2-substituted acetamido-5-nitrothiazoles and 1-(5-nitro-2-thiazolyl)-4-acylpiperazine were also prepared. The products has been tested against Schistosomiasis japonica in mice. Preliminary test results showed that the majority of aliphatic acylates of niridazole exhibited marked schistosomicidal effect against adult worms as well as larva (compounds 2, 4-8, 12, 13, 15, 18, 19), a few of aromatic and heterocyclic acylates (compounds 14, 22) and the analogs of niridazole (compounds 26, 39, 49) showed weak activity.
Acylation↗
[Studies on the chemical constituents of Piper macropodum C.DC].
Piper macropodum is used in Chinese folk medicine for the treatment of rheumatism, toothache, epilepsy and stomach ache. From the ethanolic extract of the viny stem of this plant five components were isolated, a new compound and four known compounds. On the basis of spectroscopic analysis (IR, UV, MS, 1HNMR and 13CNMR) the structure of this new compound was elucidated as (2E,4E)-N-isobutyl-2,4-icosadienamide (I). The other four compounds were identified as piperine (II), piperyline (III), daucosterol (IV) and beta-sitosterol (V). All of them were isolated from this species for the first time.
Chemical Phenomena↗
[Studies on chemical constituents of Glycyrrhiza eurycarpa P. C. Li].
A species of the genus Glycyrrhiza, G. eurycarpa P. C. Li recently reported as a new species growing in Gansu Province and Xinjiang Autonomous Region has not been studied before on its chemical constituents. This paper reports the isolation and chemical elucidation of four flavonoid glycosides from this species collected in Jinta County, Gansu Province. On the basis of physical and chemical constants and spectroscopic data (UV, IR, MS, 1HNMR and 13CNMR), compound I was confirmed as a new isoflavone diglycoside. Its structure was elucidated as formononetin-7-O[-D-apio-beta-D-furanosyl(1----2)]-beta-D-gl ucopyranoside. The new compound was named glycyroside. The other three components (II-IV) were identified as liquiritin, isoliquiritin and schaftoside, respectively.
Chemical Phenomena↗
[Genetic characteristics in yang deficiency patients].
With regard to genetic aspects, the authors determined the HLA typing in 50 cases of Yang deficiency (YD) syndrome and 230 healthy controls. Rohrer index and costae arcuarial angle were also measured in 50 cases of YD syndrome and 60 healthy controls. The results showed that the distributional frequencies of HLA-B5 (P less than 0.05), CW3 (P less than 0.01) and A9 (P less than 0.05) in YD were significantly lower than those in normal controls. It reflected the genetic characteristics of YD syndrome indirectly. The YD patients had higher Rohrer index (more than 1.50) than normal controls. The costae arcuarial angle of YD group was 80 +/- 14.35 degree (mean +/- SD), and that of normal controls was 69.5 +/- 11.83 degree. These indicated that fattiness was more often seen in the YD group.
Adolescent↗
[Studies on the structures of new flavonoids from the root of Scutellaria amoena].
From the root of Scutellaria amoena C.H. Wright, two new flavonoids (I, II) and six known flavonoids (III-VIII) were isolated. On the basis of spectroscopic analysis (UV, 1HNMR, 13CNMR, MS and CD) and chemical evidences, the structures of I and II were elucidated as (2S)-2',5,6'-trihydroxy-7-methoxyflavanone-2'-O-beta-D-glucopyrano side (I) and (2R, 3R)-2',3,5,7-tetrahydroxyflavanone (II) respectively. The other six known compounds were identified as (2S)-5,7,8-trihydroxyflavanone (III), (2S)-2',5,6',7-tetrahydroxyflavanone (IV), (2R, 3R)-2',3,5,6',7-pentahydroxyflavanone (V), 2',5,6',7-tetrahydroxyflavone (VI) norwogonin (VII) and oroxylin-A (VIII) respectively. Compounds III-VIII were obtained from this plant for the first time.
Chemical Phenomena↗
B cell proliferation in follicles, germinal centre formation and the site of neoplastic transformation in Burkitt's lymphoma.
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Animals↗
A two-year study of acceptability, side effects, and effectiveness of Norplant and Norplant-2 implants in the People's Republic of China.
A large scale, phased investigation of NORPLANT contraceptive systems was conducted in the People's Republic of China. The first phase comprehended 1,200 women in four cities. Expanded trials included 11,918 women at 12 major centers and at sub-centers by 31 May 1987. At that date 4,676 NORPLANT capsule subjects and 1,089 rod subjects had completed one year of use, 1,381 capsule acceptors had completed two years as had 197 rod users. Gross pregnancy rates were less than 0.1 per 100 for each implant type both at one and at two years. Continuation rates were 94 per 100 for each implant type at one year, and were 82.0 and 83.6 per 100 among users of NORPLANT capsule and rod implants, respectively, at two years. Disruption of menstrual function was the dominant reason for termination, but mean hemoglobin levels increased in each of the nine centers reporting values at admission and at one year. First year gross cumulative termination rates for medical reasons were 1.2 to 1.3 per 100, reaching 3.8 and 5.6 per 100 for capsule and rod implants, respectively, at two years. Microdose contraception with these levonorgestrel-releasing implants appears to be a highly acceptable and effective modality suitable for Chinese women. NORPLANT implants are now approved by the national drug regulatory agency for general use in China.
Adolescent↗
Protection by 5-(2-pyrazinyl)-4-methyl-1,2-dithiol-3-thione (oltipraz) against the hepatotoxicity of aflatoxin B1 in the rat.
A new chemoprotective agent, oltipraz, was evaluated for alleviation of aflatoxin B1-induced hepatotoxicity. Male F344 rats were fed a diet supplemented with 0.075% oltipraz and compared to rats fed the purified diet (AIN) alone. Rats were fed these diets for 1 week prior to treatment with aflatoxin B1 (AFB1) and throughout the experimental period. AFB1 was administered to rats by gavage in single doses ranging from 0.25 to 10 mg/kg body weight for acute toxicity studies and in multiple doses of 0.25 mg/kg, 5 days/week, for 2 weeks for subchronic toxicity studies. The latter protocol constitutes a tumorigenic dosing regimen. In an acute toxicity study, pretreatment with oltipraz reduced from 83 to 36% the mortality produced by 10 mg/kg AFB1. Oltipraz significantly suppressed the elevated serum levels of alanine amino transaminase and sorbitol dehydrogenase induced by sublethal doses of AFB1. In subchronic toxicity studies, the AFB1-treated rats fed AIN diet failed to gain weight over the 2-week treatment period and their liver weights were severely depressed. In contrast, the rats fed the oltipraz supplemented diet maintained a high rate of growth during AFB1 treatment. The subchronic AFB1 treatment regimen also resulted in over 75% loss of prelabeled [3H]thymidine from the liver while oltipraz supplementation largely prevented this loss. Taken together, these results indicate that oltipraz is very effective in ameliorating the toxic effects of AFB1 in rats.
Aflatoxin B1↗
Inhibitory effect of parvovirus H-1 on cultured human tumour cells or transformed cells.
The present study establishes the in vitro system for studying the oncosuppression activity of parvovirus and discovers that parvovirus H-1 can be grown cytolytically in various human cancer cell lines, which include 4 hepatoma cell lines (QGY-7703, SMMC-7721, Bel-7402, PLC/PRF/5), 3 gastric cancer cell lines (SGC-7901, MGC-80-3, MKN-28) and 1 naspharynx cancer cell line (CNE). The growth of two primary gastric cancer cell cultures from surgical cancer tissue were also inhibited by the infection of H-1. The sensitivity of cancer cells to H-1 may relate to their differentiation states. On the contrary, H-1 can neither be grown cytolytically in normal liver or stomach cells, nor inhibit their growth. Transformation of human skin fibroblasts with Simian Virus 40 activated their sensitivity to H-1. Our results thus indicate that the antineoplastic activity of H-1 in vivo involves at least its direct inhibiting or killing malignant cells.
Carcinoma, Hepatocellular↗