Search PubMed⌕ Search

Biomedical subjects

L Yang

Publications and source records attributed to L Yang.

At least 523 records · Page 29Linked to original sources
PubMed1997

A study of Helicobacterium pylori and prevention and treatment of chronic atrophic gastritis.

The rate of detection of helicobacterium pylori (HP) in chronic atrophic gastritis (CAG) is 67%, HP being a slightly aerobic Gram-negative bacterium. Some drugs of traditional Chinese medicine (TCM) for clearing away heat and for removing blood stasis have significant effect on inhibition of HP. The drugs in both the recipe for nourishing yin, clearing away heat and invigorating blood circulation and the recipe for clearing away heat and invigorating blood circulation have inhibitory action on HP in vitro. All patients with CAG have symptoms of damp-heat and blood stasis. Radix et Rhizoma Rhei and Rhizoma Coptidis Decoction for Purging Stomach-Fire ([symbol: see text]) as the basic recipe and "Huo Wei" ([symbol: see text]) No. 2 recipe as the supplementary have good inhibitory effect on HP in inhibition tests. The results show several forms of the medicine all resulted in significant good therapeutic effect.

Diagnosis, Differential↗
PubMed1997

[Mitral valve prolapse and infective endocarditis].

The data from patients with mitral valve prolapse and infective endocarditis were analysed. Twenty-one patients were found, including 13 males and 8 females, with a mean age of 32 years old (range 9 to 61 years). They accounted for 23% of all patients with infective endocarditis, and 48% of those with mitral valve endocarditis diagnosed in our hospital between Jan, 1984 to Dec, 1996. The clinical features were indistinct onset, high incidence of serious complications such as cardiac failure and emboli to large vessels, especially cerebral vessel. Echocardiography played an important role in the diagnosis of the disease.

Adolescent↗
PubMed1997

[Changes of 5-HT2A receptor binding on platelet of patients with CAD and the effects of exercise test].

It is known both 5-HT2A receptors of platelet and vascular smooth muscle regulate vascular constriction and platelet aggregation to 5-HT challenge. And that 5-HT-induced hypperreactivity of vascular smooth muscle and platelet were noted in patients with coronary artery disease (CAD). In order to investigate the mechanism of platelet hyperreactivity in cardiovascular disease. Platelet 5-HT2A receptor were measured by specific binding of 3H-ketanserin in patients with CAD (CAD group) and patients with chest pain but without CAD as well as healthy subjects (control group) before and after submaximal treadmill exercise. At the same time the levels of plasma 5-HT were also measured. The results showed: (1) In the resting state, 3H-ketanserin exhibited saturable binding with Bmax of 71.1 +/- 10.1 fmol/mg protein, Kd 1.35 +/- 0.20 nmol/L in control group (n = 8) and with Bmax of 102.1 +/- 22.2 fmol/mg protein, Kd 2.44 +/- 0.66 nmol/L in CAD group (n = 10). Between two groups had no significant difference (P > 0.05). And the specific binding of 2.0 nmol/L 3H-ketanserin and the level of plasma 5-HT in CAD group were higher than those in control group (P < 0.05). (2) After exercise all of the specific binding of 2.0 nmol/L 3H-ketanserin, Bmax of receptor binding and the level of plasma 5-HT were significantly increased in CAD group but not in control group. The above results suggested that the up-regulation of platelet 5-HT2A receptor was involved in the platelet hyperreactivity in CAD. The submaximal treadmill exercise had no significant effect on platelet function in control group, but it could lead to platelet 5-HT2A receptor increment and platelet activation in CAD group. Therefore, these changes of platelet might play a role in the acute myocardial ischemia induced by exercise.

Adult↗
PubMed1997

[Preparation method of foamed aerosol for use in vagina].

The extraction of medicinal materials, compatibility of liquor and prescription of emulsion for use in vagina were observed. The result shows that through compound extraction, removal of tannic materials, decolorization and water precipitation, with propylene glycol and ethylene glycol as latent solvent and using lactic acid to adjust to pH4.5, a clarified solution can be obtained, and then with the help of Tween-spans emulisifying agent and propellant the stable emulsion is formed.

Administration, Intravaginal↗
PubMed1997

[Alkaloid production of cultured coptis cells by two-stage suspension-culture].

In this study the asexual cell line H292 induced and selected from Coptis gulinensis had rapid growth rate and could stably produce alkaloids. By the one-stage method, after the cell suspensions were cultured on the same medium for six weeks, the increased dry and fresh weights of the cells were 20.96 g/L and 174.92 g/L respectively. The content of the total alkaloids in the cells was 14.79 mg/g cell dw. Per litter liquid medium could provide 323 mg alkaloid. In contrast, the cells were cultured by two-stage method. After having been cultured on the medium which contributed to the growth of the cells for three weeks, the cells were transferred to the medium which contributed to the production of the alkaloid and cultured for three weeks. Six weeks later, the dry and fresh weights of the cells were 16.72 g/L and 127.44 g/L, respectively. The biomass was lower than that by one-stage method, but the content of the total alkaloids was as high as 31.76 mg/g cell dw, which was much more than that by one-stage method. In addition, the content of the alkaloid in the medium was 25.31 mg/L. Per litter liquid medium could provide 556 mg alkaloid. The total yield of alkaloid obtained by two-stage method was 1.72 times than that by one-stage method.

Alkaloids↗
PubMed1997

[Chemical constituents of rhizoma Pinelliae pedatisecta].

Five compounds were isolated from the alkaloid extract of Rhizoma Pinelliae Pedatisecta and their structures were determined as pedatisectine F(I), hypoxanthine (II), erythritol (III), uridine (IV) and pedatisectine G (V), of which I and V are new compounds, while II, III and IV were found in this plant for the first time.

Alkaloids↗
PubMed1997

[A primary study on antagonizing effects of anti-snake venom Chinese herbs on endothelin-1 and sarafotoxin 6b].

Some anti-snake venom Chinese herbs were used to test the antagonizing effect on ET-1 and S6b. Oral administration has shown that both the water and alcohol extracts from Cissus assamica and Aristolochia fordiana, and the water extracts from Desmodium microphyllum, Cynanthum paniculatum and Polygonum cillinerve are very helpful in reducing the acute death caused by ET-1 and S6b(i.v.), while the extracts from Cissus assamica, Aristolochia fordiana and Cynanthum paniculatum can dilate the vasoconstriction by ET-1 in a dose dependent manner. Pharmacodynamic parameters have shown that the potencies of alcohol extracts from Cissus assamica and Aristolochia fordiana are greater than that of Cynanthum paniculatum. These data suggest that traditional anti-snake venom herbs have antagonizing effects on ET-1.

Animals↗
PubMed1997

[Identification of Scutellaria barbata D. Don and its adultrants].

Studies have been made on the comparison and identification of morphological and anatomical characteristics of six species Scutellaria barbata and its adultrants. Several tables and drawings are given. This paper may be helpful to pharmacognosists for identifying commercial crude drugs.

Drug Contamination↗
PubMed1997

[Study on diagnosis of oral mucosal melanoma with histology, electron microscopy (EM) and immunohistochemistry].

Fifteen cases of primary oral mucosal melanoma were studied with the methods of Fontana Staining, EM, and immunohistochemistry. The results showed that 4 of 15 cases were non-pigmented lesions. In these cases, two were positive with Fontana staining. Pigment body could not be found in three cases observed under EM, but all the 15 cases were positive with immunohistochemical staining. The results suggested that the immunohistochemical staining should be done for those cases suspected as non-pigment melanoma.

Humans↗
PubMed1997

[The in vitro inhibitory effect of CD8+ cells from patients with aplastic anemia on normal CFU-GM growth was blocked by cimetidine].

OBJECTIVE: To investigate the effect of histamine type II (H2) receptors on the inhibition of hematopoiesis by CD8+ cells from aplastic anemia (AA) patients. METHODS: The effects of CD8+ cells and/or cimetidine, alone or in combination, on normal human CFU-GM growth were studied by using CFU-GM assay. RESULTS: The CD8+ cells from the peripheral blood of AA patients significantly suppressed the growth of normal allogeneic CFU-GM. This inhibitory effect could be blocked by 0.5 x 10(-5) mol/L or 1.0 x 10(-5) mol/L cimetidine. 1.0 x 10(-5) mol/L cimetidine alone slightly inhibited the growth of normal CFU-GM, but 0.5 x 10(-5) mol/L cimetidine did not. CONCLUSION: H2 receptor antagonist cimetidine abolished the suppressive effect of AA patients CDB+ cells on the growth of normal CFU-GM.

Adult↗
PubMed1997

[Effects of cytokines on multidrug-resistance in K562/A02 cells].

OBJECTIVE: To explore the effects of cytokines on human leukemic cell line K562/S and its multidrug-resistant counterpart K562/A02. METHODS: The toxicities of cytokines and the IC50 (the concentration causing 50% inhibition of cell growth) of DNR were assayed by MTT method; intracellular drug concentration was measured by fluorometry; p-glycoprotein (p-gp) expression was detected by APAAP and mdr-1 mRNA was assayed by RT-PCR. RESULTS: The IC50 of DNR for K562/A02 and K562/S cells were 45.08 microg/ml and 0.607 microg/ml, respectively. Pretreating K562/A02 cells with rhu IFN (500 U/ml) or rhu IL-2 (250 U/ml) for 24 hours partially restored the sensitivity of K562/A02 cells to DNR (IC50 were 16.39 and 11.96 microg/ml, respectively) but had not effect on K562/S cells, and it elevated the intracellular DNR accumulation in K562/A02 from 2151 ng/mg x protein to 2570 and 2503ng/mg x protein, respectively. p-gp and mdr-1 mRNA were not down regulated. By contrast, rhu G-CSF and rhu GM-CSF had no effect on either K562/A02 or K562/S. CONCLUSION: rhu IFN or rhu IL-2 could partially restore the sensitivity of K562/A02 to DNR and elevate the intracellular DNR accumulation via a mechanism independent of p-gp or mdr-1 mRNA down-regulation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

[Determination of dimethyl ether correction factors in gas chromatography with TCD and FID].

Dimethyl ether (DME) correction factors in gas chromatography with thermal conductivity detector (TCD) and flame ionization detector (FID) by using H2 as carrier gas were determined in this work. The homemade DME gas was quantitatively absorbed in ice-cold water. With ethanol as standard, the aqueous mixture was injected into a gas chromatograph, equipped with serially-connected TCD and FID. The weight correction factors of DME based on methanol were 0.86 and 0.55 for TCD and FID respectively. The result for TCD was also confirmed by calculation based on the stoichiometrical transformation of methanol into DME in reaction gas chromatography.

English Abstract↗
PubMed1997

[Theoretical investigation of dynamic process in capillary column gas chromatographic system--effect of radial diffusion on elution profile].

Based on a mass balance equation, in this paper, the kinetic model of chromatography including influence of the radial diffusion on the mass transfer process is set up. Based on the hypothesis of Giddings, this model has been simplified. In this way, the expressions of the first moment, the second and the third central moment for this model are derived by Laplace transform in detail. The results show the radial diffusion affects not only the column efficiency, the peak spreading and the peak symmetry, but also the retention time.

English Abstract↗
PubMed1997

Immobilized IDA-type Cu2+-chelating membrane affinity chromatography for purification of bovine liver catalase.

Cu2+-chelating membrane medium based on iminodiacetate-substituted modified short cotton cellulose was examined to purify bovine liver catalase (BLC) by affinity chromatography. The buffer pH notably affect BLC binding to the Cu2+-chelating membrane adsorbent. The results showed that under the chromatographic conditions chosen, 67.7% recovery of BLC attained with an overall 4.7-fold increase in specific activity in a single step. After purification of BLC, the chelating membrane adsorbent can easily be regenerated by imidazole or EDTA buffer. Different results were obtained by the two regeneration methods: the later is more effective than the former in reviving the purification characters of the chelating membrane adsorbent.

Animals↗
PubMed1997

An evaluation of the role of nuclear cytoplasmic ratios and nuclear volume densities as diagnostic indicators in metaplastic, dysplastic and neoplastic lesions of the human cheek.

The increase in nuclear cytoplasmic (N/C) ratio is one of the features of cellular atypia which is used in the histopathological assessment of premalignant lesions of the oral mucosa. Since this feature is readily quantifiable using morphometry, we have analysed both N/C and nuclear volume densities in basal and spinous cells from human cheek lesions with and without malignant potential in order to ascertain the validity of this parameter as a predictor. Using a strictly standardised sampling procedure, measurements of cellular and nuclear areas of basal and spinous cells from normal and pathological human cheek mucosa were made on haematoxylin and eosin-stained sections using a VIDAS image analyser. Cases examined comprised fibrous hyperplasia (FH), traumatic inflammation (IF), benign hyperkeratosis (HK), lichen planus (LI), leukoplakia with dysplasia (DYS), squamous cell papilloma (PP), dysplastic epithelium from the edges adjacent to invasive carcinoma (CE) and islands from invasive squamous cell carcinoma (CI). In basal cells, N/C ratios and nuclear volume densities were lower than values obtained for the normal controls. In spinous cells, these parameters were elevated in the potentially premalignant lesions (DYS, CE) as well as in CI but values were similarly elevated in FH, IF, HK and PP, lesions which appear to have no malignant potential. The N/C ratio is of no value as a predictor of malignant potential in basal or spinous cells from cheek lesions. The putative increase in N/C which has been previously described qualitatively is probably due to increased nuclear hyperchromatism, which may provide an illusory increase in relative nuclear size at the expense of the cytoplasm.

Carcinoma, Squamous Cell↗
PubMed1997

CAND3: a ubiquitously expressed gene immediately adjacent and in opposite transcriptional orientation to the ATM gene at 11q23.1.

Using a magnetic beads-mediated cDNA selection procedure and a fetal brain expression library, we identified a transcriptional unit within a cosmid positive for the marker D11S384. Pursuit of its full-length cDNA led to the cloning of the third candidate gene (CAND3) we studied in our quest for the ataxia-telangiectasia (A-T) gene, ATM. CAND3 spans approximately 140 kb of genomic DNA and is located immediately centrimeric to ATM, with 544 bp of DNA separating the two genes. CAND3 encodes two ubiquitously expressed transcripts of approximately 5.8 kb and approximately 4.6 kb that are divergently transcribed from a promoter region common to ATM. Nucleotide sequence was determined for one of its alternately spliced transcripts. The predicted protein has 1175 amino acids and is novel in sequence, with only weak homologies to transcriptional factors, nucleoporin protein, and protein kinases, including members of the phosphatidylinositol 3-kinase (PI-3 kinase) family. Although neither homology to ATM nor any mutation of CAND3 in A-T patients has been found, the head-to-head arrangement of CAND3 and ATM, with expression of both housekeeping genes from a common stretch of 544 bp intergenic DNA, suggests a bi-directional promoter possibly for co-regulation of biologically related functions. YACs, BACs, cosmids, and STSs are defined to aid in further study of this gene.

Amino Acid Sequence↗
PubMed1997

The anti-inflammatory effects of ketoprofen in animal experiments.

The authors investigated the anti-inflammatory actions of ketoprofen using a battery of tests: in the rat paw oedema test induced by five different inciters, in the capillary permeability test, and in measuring the interleukin-8 (IL-8) production and superoxide dismutase (SOD) activity. The findings in these studies show that ketoprofen inhibits rat paw oedema, suppresses capillary permeability, reduces IL-8 production and increases SOD activity in the acetic-acid-induced inflammatory state. These results would seem to provide a clear rationale for exploring the usefulness of ketoprofen in the treatment of acute and chronic inflammatory diseases.

Acetic Acid↗