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Biomedical subjects

Y R Wang

Publications and source records attributed to Y R Wang.

35 records · Page 2Linked to original sources
PubMed1997

[A study of the mechanism of L-NNA on sleep inhibition].

In the present study, the sleep-waking cycle and the immunoreactivity of 5-HT-containing neurons in rats receiving intraperitoneal injections of N-Nitro-L-arginine (L-NNA, 50 mg/kg) and L-arginine (L-arg, 110 mg/kg) were observed respectively. The results showed that injection of L-NNA suppressed both slow wave sleep (SWS) and rapid eye movement sleep (REMS) and increased mean arterial pressure (MAP). L-arg markedly attenuated MAP, whereas SWS and REMS were unchanged. The effects of L-NNA on sleep and MAP were reversed by preinjection of L-arg. In comparison with control group, the positive cells in dorsal raphe nucleus (DR) and raphe magus nucleus (MnR) increased 2 h after injection of L-NNA. The effect was attenuated by preadministration of L-arg. All these results suggest that L-arg: NO pathway is involved in the regulation of sleep-waking cycle and the increment of the positive immunoreactivity of the 5-HT-containing neurons in the DR may be related to the sleep-suppressive effects induced by L-NNA.

Animals↗
PubMed1996

Substrate specificity of monomeric and dimeric alpha-sarcin.

The substrate specificity of monomeric and dimeric forms of alpha-sarcin was investigated by membrane blotting procedures. Dimeric alpha-sarcin fails to inactivate ribosomes as well as to hydrolyze mini-stem-loop RNA, whereas monomeric alpha-sarcin catalyzes both substrates. Both monomeric and dimeric alpha-sarcin are effective ribonucleases that are displayed by in situ RNA-impregnated gel electrophoresis. The same purine base specificity was detected for both dimeric and monomeric forms. alpha-Sarcin is also an effective deoxyribonuclease to supercoiled DNA. The action of alpha-sarcin as deoxyribonuclease and ribonuclease is inhibited by the presence of SDS (3.5 x 10(-6) M); the inhibition on ribonuclease, but not on deoxyribonuclease, is reversible if the proteins are renatured.

Animals↗
PubMed1996

Enhanced expression of hepatic genes in copper-deficient rats detected by the messenger RNA differential display method.

The influence of copper (Cu) status on hepatic gene expression was examined by using the "messenger RNA differential display" technology. This method involves the distribution of mRNA in a two-dimensional array for the rapid identification and cloning of differentially expressed genes. Livers from male Sprague-Dawley rats that had been fed a Cu-deficient (CD) diet (9.4 micromol/kg) or a Cu-adequate (CA) diet (103.9 micromol/kg) for 6 wk were used to supply cytosolic RNA. Cytosolic RNA were reverse-transcribed in the presence of anchor primers and then amplified by polymerase chain reaction with anchor and arbitrary primer sets. The amplified cDNA were then resolved by denaturing polyacrylamide gel electrophoresis. Differences in mRNA expression between the CD and CA rats were identified. DNA fragments were cloned, sequenced and used as probes for Northern blot analysis to confirm that the identified genes were differentially expressed. The analysis of cDNA sequences by computer searches against DNA and protein databases revealed that one cDNA fragment, whose mRNA abundance was enhanced 1.2-fold by copper deficiency, is novel. Four other cDNA fragments were found to have substantial homology with rat ferritin mRNA; rat fetuin mRNA; rat mitochondrial 12S and 16S rRNA, phenylalanine-, valine- and leucine-tRNA genes; rat mitochondrial genes for 16S rRNA, tRNA-leucine and tRNA-valine; and their mRNA abundance was 0.6- to 0.8-fold higher in Cu-deficient rats. Five additional cDNAs detected by this method appeared to represent novel genes because they exhibited no substantial homology to recorded gene and protein sequences deposited in DNA and protein databases. These results demonstrate the usefulness of this technology in the detection of genes which were differentially expressed as a result of the deprivation of a single nutrient, dietary copper, in this research project.

Animals↗
PubMed1996

Heat shock pretreatment prevents hydrogen peroxide injury of pulmonary endothelial cells and macrophages in culture.

The purpose of the present study was to determine whether heat shock pretreatment would protect pulmonary endothelial cells and alveolar macrophages against hydrogen peroxide (H2O2)-induced injury. The bovine pulmonary artery endothelial cells (BPAECs) heat-shocked (42 degrees C for 2 h) prior to exposure to H2O2 (1 mmol/L for 45 min) showed significant decrease in H2O2-mediated increment of release of lactate dehydrogenase and production of thiobarbituric acid-reactive substances, and obvious alleviation in H2O2-induced decrease in activities of catalase and superoxide dismutase. Heat-shocked (42 degrees C for 2 h) rat pulmonary alveolar macrophages (PAMs) also obtained acquired resistance to injury by subsequent exposure of 1, 2, or 3 mmol/L H2O2 for 45 min. Simultaneously with this acquired oxidative resistance, Northern blot analysis showed that heat-shocked BPAECs and PAMs, contained an increased level of mRNA coding for the inducible form of heat shock protein 70 (HSP70), and Western blot analysis indicated that there were increased expression of HSP70. Inhibition of protein synthesis by cycloheximide (25 micrograms/mL) and inhibition of RNA synthesis by actinomycin D (5 micrograms/mL) prevented the cytoprotection against H2O2. These results are consistent with the hypothesis that heat shock pretreatment would protect pulmonary endothelial cells and alveolar macrophages against H2O2-induced injury, and possibly that HSPs play a role in this cytoprotection.

Animals↗
PubMed1996

Copper deficiency increases hepatic apolipoprotein B secretion and mRNA editing in rats.

Male weanling Sprague-Dawley rats were assigned to copper-deficient (9.0 mumol Cu/kg diet) or copper-adequate (102 mumol Cu/kg diet) dietary treatments for 6 wk. Pulse-chase studies using freshly isolated rat liver parenchymal cells demonstrated that apolipoprotein B (apoB)-48 and apoB-100 syntheses were not altered, but secretion was increased twofold in hepatocytes derived from copper-deficient rats. Both plasma apoB-48 and apoB-100 levels were increased by copper deficiency, but only the apoB-48 increase was significant. Hepatic apoB mRNA editing, expressed as a ratio of apoB-48 mRNA to apoB-48 plus apoB-100 mRNA, was significantly increased from 60.8% in copper-adequate to 70.2% in copper-deficient rats. Moreover, hepatic apoB mRNA abundance was not significantly altered by copper deficiency. Thus the increased amount of nascent apoB-48 secreted into the medium as well as the enhanced apoB mRNA editing may have contributed to the differential increase in plasma apoB-48 over apoB-100 level in copper-deficient rats.

Animals↗
PubMed1994

Tone recognition of continuous Mandarin speech assisted with prosodic information.

In this paper, a simple recurrent neural network (SRNN) is employed to model the prosody of continuous Mandarin speech to assist tone recognition. For each syllable in continuous speech, several acoustic features carrying prosodic information are extracted and taken as inputs to the SRNN. If proper linguistic features extracted from the context of the syllable are set as output targets, the SRNN can learn to represent the prosodic state of the utterance at the syllable using its hidden nodes. Outputs of the hidden nodes then serve as additional recognition features to assist recognition of the tone of the syllable. The performance of the proposed tone recognition approach was examined by simulation on a multilayer perception (MLP)-based speaker-dependent tone recognition task. The recognition rate was improved from 91.38% to 93.10%. The SRNN prosodic model is further analyzed to exploit the linguistic meaning of prosodic states. By vector quantizing the outputs of the hidden nodes of the SRNN, a finite-state automata that roughly represents the mechanism of human prosody pronunciation can be obtained.

China↗
PubMed1993

[Dissolution rate of berberine in ermiao pills].

The dissolution rate of Ermiao Pills was determined by the Cup Method in artificial gastric juice and artificial intestinal juice. Parameter T50, T alpha and n were obtained. The F value shows no significant difference in between the two groups (P > 0.05), indicating that the above two releasing media do not markedly influence the dissolution rate of Ermiao Pills.

Berberine↗
PubMed1990

A new approach to the treatment of malignant effusion.

Lymphocytes isolated from malignant effusion were induced to become LAK cells after in vitro culture with rIL-2. 28 patients with malignant effusion were treated by i.p. or intrapleural administration of autologous LAK cells combined with rIL-2 or by rIL-2 alone. The effusion disappeared in 13 patients and significantly decreased in another 13. Two patients did not respond to the treatment. Tumor cells in effusion disappeared or significantly decreased and lymphocytes significantly increased in all responses. Except for transient fever in 9 patients, no serious side effects were found.

Adult↗
PubMed1988

Phosalone applied to cotton (Gossypium hirsutum L.): its deposition and persistence on foliages, soils and final residues in seeds.

Phosalone, O,O-diethyl-S-(6-chloro-1,3-benzoxazol-2(3H)-onyl)methyl phosphorodithioate, was field-applied by ground equipment to cotton (Gossypium hirsutum L.) at the rates of 1050 and 2100 g a.i./ha, respectively, to determine its dissipation on leaves and soils and the residues in seeds at harvest. The insecticide concentrations on cotton leaves and soils were measured periodically for 14 days following its application. It was found that the half lives of the insecticide on cotton leaves at the dosages of 1050 and 2100 g a.i./ha were 6.8 and 6.3 days, respectively. And the half lives on soils for the 2 dosages were 7 and 5.8 days, respectively. The residues remaining in soils at harvest time were 0.072 and 0.121 mg/kg 14 days post-application and the residues in cotton seeds were relatively low (less than 0.02-0.12 mg/kg).

Gossypium↗
PubMedDate not supplied

Growth inhibition of cancer cells by an active metabolite of a novel vitamin D prodrug.

Active vitamin D compounds have been developed that maintain antiproliferative properties with low calcemic activity. BCI-210, a novel vitamin D pro-drug developed in our laboratory, is activated through side chain hydroxylation and possesses lower calcemic activity than calcitriol. The human hepatoma cell line (HepG2) was used to produce an active metabolite, which was characterized and identified as 27-hydroxy-BCI-210. We compared the ability of 27-OH-BCI-210 with calcitriol to inhibit proliferation of prostate (LNCaP), and breast (MCF-7) cancer cells. Cells were plated in multi-well plates and incubated with vehicle or vitamin D compounds for 6 days, after which the cell numbers were determined by a colorimetric assay. 27-OH-BCI-210 produced a dose-dependent growth inhibition, although a concentration five-fold greater than calcitriol was required to produce equivalent inhibition. We also examined the antiproliferative activity of 27-OH-BCI-210 in combination with chemotherapeutic drugs. With genistein and doxorubicin, 27-OH-BCI-210 produced synergistic inhibition of proliferation of LNCaP and MCF-7 cells. These synergistic interactions suggest the potential clinical utility of 27-OH-BCI-210 in the treatment of prostate and breast tumors.

Antineoplastic Combined Chemotherapy Protocols↗