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Biomedical subjects

S Liu

Publications and source records attributed to S Liu.

At least 577 records · Page 32Linked to original sources
PubMed1998

[Early changes in rat lungs caused by lower-dose quartz dust].

OBJECTIVE: To study the features of damages in the lungs caused by lower dose quartz. METHODS: Cell count, contents of protein and total lipid and activity of lactate dehydrogenase (LDH) in bronchoalveolar lavage, changes in content of collagen in the whole lungs of the rats were determined after their exposure to lower dose quartz and asbestosdust (10 mg per rat), and pathological changes in the lungs were also observed. RESULTS: Cell count, contents of protein and total lipid and activity of lactate dehydrogenase in bronchoalveolar lavage, and content of total collagen in the whole lungs increased persistently in the rats exposed to quartz; and, only cell count and activity of lactate dehydrogenase increased transiently in rats 10 days after exposure to asbestos, and content of collagen also increased gradually, but not so obviously as caused by quartz. CONCLUSION: Lower dose quartz has very strong toxicity to the lungs leading to pulmonary fibrosis.

Animals↗
PubMed1998

[Studies on cloned genomic differential DNA fragments extracted from esophageal carcinoma and non-cancerous esophageal tissues in Linxian County].

OBJECTIVE: To isolate the genes involved in carcinogenesis of esophageal cancer and to provide a molecular marker for screening and early detection of it in susceptible individuals. METHODS: DNA extracted from 12 matched pairs of esophageal cancer and non-cancerous tissues in patients of Linxian County, Henan Province, a high incidence area for esophageal cancer, and differential DNA fragments were isolated with arbitrary primer polymerase chain reaction (AP-PCR), cloned and sequenced. Restriction endonuclease Dra I and Hind III were used to digest genomic DNA in the pair-matched cancerous and non-cancerous esophageal tissues for Southern blot analysis. RESULTS: There was a randomly amplified differential DNA fragment of about 1.0 kb in cancerous tissues in three of the twelve cases with esophageal cancer, but no such fragments could be found in corresponding non-cancerous tissues. Sequence analysis showed that no homologous DNA in GeneBank database as same as 11T differential DNA fragments. Southern blot analysis showed that there was significant difference between pair-matched cancerous and non-cancerous tissues. CONCLUSION: 11T differential DNA fragment appeared during carcinogenesis of the esophagus, and further investigations were needed to study if it could be regarded as a new kind of oncogene or a biomarker of it.

Base Sequence↗
PubMed1998

Oxidative and malondialdehyde modification of low-density lipoprotein: a comparative study of binding and degradation by macrophages and endothelial cells.

Comparative study of oxidatively modified low-density lipoprotein (Ox-LDL) and malondialdehyde-modified low-density lipoprotein (MDA-LDL) is important for further understanding the biological properties of Ox-LDL, such as its toxic effects, immunogenicity and multiplicity of scavenger receptor binding. In this study, the characteristics of Ox-LDL and MDA-LDL binding and degradation were compared. The results show that when their degree of modification (as determined by relative electrophoretic mobility) was similar, the binding and degradation of Ox-LDL by the macrophage cell line P388D1 were greater than those of MDA-LDL. The binding and degradation of Ox-LDL by macrophages and human umbilical vein endothelial cells increased with the degree of modification. In addition, Ox-LDL or MDA-LDL could competitively inhibit binding of labelled Ox-LDL or labelled MDA-LDL to their respective macrophage receptors, and could partially inhibit each other.

Animals↗
PubMed1998

[Comparison of changes in oncogene of human embryo lung cells before and after chemical modification for chrysotile].

OBJECTIVE: To seek for a suitable chamical agent for surface modification of chrysotile. METHODS: The effects of aluminum citrate, mixed rare earth and sodium selenite on c-Ha-ras oncogene and P21ras protein in the transformation of human embryo lung cells caused by chrysotile were studied. RESULTS: The transcription level of c-Ha-ras oncogene and the content of P21ras in those exposed to chrysotile were significantly higher than those in the controls. The transcription level of c-Ha-ras oncogene and the content of P21ras in those exposed to chrysotile treated in advance with three kinds of chemicals mentioned above were significantly lower than those in untreated. CONCLUSION: Treatment of chrysotile with three kinds of above-mentioned chemicals in advance could reduce its carcinogenecity in human beings.

Aluminum Compounds↗
PubMed1998

[Studies on incidence of malignant tumor in workers exposed to dust in a mine in 30 years].

OBJECTIVE: To investigate incidence of malignant tumor in workers exposed to dust in a mine during the past 30 years. METHODS: A retrospective cohort study was conducted in 16,711 workers exposed to dust and 7,598 non-exposed workers. RESULTS: Incidence of lung cancer in exposed workers ranked the first place, whth an SMR of 2.648, as compared with that of non-exposed workers. Incidence of lung cancer in the dust-exposed workers with a longer duration of employment was significantly higher than in those with a shorter one. Incidence of lung cancer in exposed workers with a wetoperation mode was lower than that in those with dry-operation mode. CONCLUSION: Malignant tumor, especially lung cancer, occurred more frequently in the workers exposed to dust, which could be a potential risk factor contributing to carcinogenesis.

Adolescent↗
PubMed1998

[Analysis of causes of revision after hip replacement].

From 1974 to 1991, two hundred and sixty-four cases of hip replacement were performed. These cases composed of 150 cases of artificial femoral head prosthesis replacement and 114 cases of total hip replacement. Fifteen cases were revised after the first replacement in 7.4 years average (5-16 years). The revision rate was 5.7%. The causes of revision were loose or subside of prosthesis, wear and tear of acetabulum, dislocation of artificial hip joint, etc, which caused pain and dysfunction. The revision cases were followed up for 4.7 years average with good result. To prevent revision, The medully canal shonld not be too wide and in osteoporosis cases, bone cement was suggested to apply. The chondrium of acetabulum should be removed completely.

Aged↗
PubMed1998

REMI mutagenesis and identification of pathogenic mutants in blast fungus (Magnaporthe grisea).

Blast fungus' mutant, which is very difficult to obtain, is the key substance in the study of the relation between pathogen and plant. Rice-Aichi-ashahi was used as the host and plasmid pBF101 or pCSN43 as foreign DNA fragment, and REMI mutagenesis was applied to tag the pathogenic sequence in rice blast fungus M.grisea. Three mutants (R2H65, R2H69 and R2B1565) related to pathogenicity were recovered from several hundreds of transformants. R2H69 and R2H65 produced merely strange conidia which could not form appressorium or yield abnormals, and pathogenicity test further confirmed that they were unable to cause disease. R2B1565 possesses the same phenotypes as those of the wild type except that the ability of causing disease was much reduced.

DNA Restriction Enzymes↗
PubMed1998

[A preliminary report of antiscar formation effect by subconjunctival injection of mitomycin C before trabeculectomy in glaucoma].

To improve the function of filtering blebs and increase the successful rate of the trabeculectomy, mitomycin C injection 0.02 mg.ml-1 was given subconjunctivally at the operative site before trabeculectomy in 32 patients (38 eyes) with moderate or late glaucoma. All patients were followed up for 6 to 12 months. The results showed that the rate of functional blebs were 93.7%. The successful rate of the operation was 94.7%. The common postoperative complication was shallow anterior chamber (7.9%). These findings indicate that the subconjunctival injection of mitomycin C before operation is a safe, effective method for antiscar formation.

Adult↗
PubMed1998

[Drug resistance study and detection of methicillin-resistant staphylococci].

MRSA and MRSE were identified by detecting oxacillin resistance of 107 strains of staphylococci from clinical sources. The positive rates of MRSA were 45.2% and 16.9%, respectively among the whole number of staphylococci examined. Antibiotic-resistant strains were detected with disks by Kirby-Bauer method. All MRSA and MRSE strains were multi-resistant. Resistant rates of MRSA and MRSE were higher than MSSA and MSSE. The positive rates of beta lactamase producing in MRSA and MRSE were significantly higher than MSSA and MSSE (P< 0.05 and P< 0.01) respectively. These results indicated that MRSA and MRSE were the main pathogens in the clinical infection. MRSA and MRSE detection are important for the early diagnosis and treatment of patients with infective diseases.

Drug Resistance, Multiple↗
PubMed1998

[Expression and significance of p53, c-erbB2, CEA proteins in colorectal adenoma and carcinoma].

Expression of p53, c-erB2, CEA proteins in 15 cases of normal colorectal mucosa, 40 adenoma and 40 carcinoma of colon were studied with immunohistochemistry. The positive rate of p53, c-erbB2, CEA in colorectal carcinomas were significantly higher than those in adenoma. The positive rate of p53 in adenoma with severe atypical hyperplasia was higher than that in the mild (P< 0.01), and was higher in colorectal carcinomas of poor differentiation that that in the well-differentiated ones (P< 0.05). The novel type monoclonal antibody of CEA Col-1 had a high sensitivity and specificity for the tissue of colorectal carcinoma in which the positive rate was 85%. The results suggested the alteration p53, c-erbB2 are involve in the tumorgenesis and development of colorectal carcinoma; and detection of p53, c-erbB2 and CEA proteins are helpful in distinguishing benign and malignant polyps of colon.

Adenocarcinoma↗
PubMed1998

[Antiviral and antibacterial actions of bingduqing granules in vitro].

The antiviral and antibacterial actions in vitro of bingduqing granules which consists of nine kinds of Chinese traditional medicinal herbs were observed. The results showed that the inhibitive concentrations of bingduqing granules for Adv-7, RSV, HSV-1, and influenza virus A3, were >-6.9, 8.3, 13.8 and 83 mg x ml-1, respectively; while the minimum inhibitive concentrations for Staphylococcus aureus, Staphylococcus epidermidis, Type A and B Streptococci, and pseudomonas aeruginosa were 0.03125, 0.03125, 0.125, 0.125, and 0.25 g x ml-1, respectively. This study provide a pharmacodynamics basis for clinical application of Bingduqing Granules in the treatment of respiratory tract infection.

Adenoviruses, Human↗
PubMed1998

[Study on the mechanism for fetal asphyxia in intrahepatic cholestasis of pregnancy].

OBJECTIVE: To investigate the cause of fetal asphyxia of mothers with intrahepatic cholestasis of pregnancy (ICP). METHODS: The cord plasma erythropoietin (EPO) concentrations were measured in 37 infants of mothers with ICP and 46 control infants after elective cesarean section. Furthermore, the transfer of oxygen across the placental membranes in ICP group (n = 7) were compared with controls (n = 8) by dual perfusion of the human placental lobule in vitro. RESULTS: The oxygen transfer across the placental membrane in ICP was similar to the controls (P < 0.05). However cord venous EPO was lower in infants delivered by elective cesarean section from women with ICP (13.58 +/- 8.88 IU/L, P < 0.05) than that in control infants (20.43 +/- 14.15 IU/L). CONCLUSION: The transfer of oxygen across the placental membrane in ICP may be normal. The lower cord venous EPO value in ICP may be mainly responsible for the fetal asphyxia.

Adult↗
PubMed1998

[Relationship between pregnancy loss and antiphospholipid antibody].

OBJECTIVE: To investigate the relationship between history of pregnancy loss and antiphospholipid antibodies (APA), including anticardiolipin (ACA) and lupus anti-coagulant antibodies (LA). METHODS: Levels of serum APA, ACA and LA were determined by enzyme linked immunoabsorbent assay and activated partial thromboplastin time method respectively in 122 patients with history of unexplained pregnancy loss (study group) and 100 normal nonpregnant women (control group). The study group was further divided into three subgroups: embryo growth arrest (n = 23), stillbirth (n = 31), and recurrent abortion (n = 63). RESULTS: The positive rates of APA, ACA, LA in the study group were significantly higher than those in controls (P < 0.05-0.001). The above significance was true in both stillbirth and recurrent abortion groups but not in embryo growth arrest group. CONCLUSIONS: Levels of serum APA were associated with pregnancy loss, especially recurrent abortion and stillbirth. We suggested routine screening of serum APA should be performed in patients with history of fetal wastage for the sake of early treatment.

Abortion, Habitual↗
PubMed1998

[Comparison between selenomethionine and sodium selenite on action potentials of cultured myocardiocytes].

The action potentials of ventricular myocardial cells were recorded with glass microelectrodes inside the cells from neonatal Wistar rats treated with selenomethionine and sodium selenite in concentrations of 1.0, 2.0, and 4.0 mg/L selenium. Both of selenomethionine and sodium selenite decreased the action potential parameters, such as action potential amplitude(APA), overshoot(OS), threshold potential(TP), maximum diastolic potential (MDP) and maximum rate of depolarization (Vmax). Selenomethionine decreased the action potential duration at 10%, 50% and 90% repolarization (APD10, APD50 and APD90), while sodium selenite prolonged APD10, APD50 and APD90 at dose of 4.0 mg/L selenium and decreased APD50 and APD90 at dose of 1.0 and 2.0 mg/L selenium. The results indicated that both sodium selenite and selenomethionine inhibit the transmembrane movement of Ca2- and sodium selenite also inhibits transmembrane movement of K+.

Action Potentials↗
PubMed1998

[Relationship between the expression level of alpha-MHC gene and cardiac contractility during heart failure].

To investigate the molecular basis of the decrease in myocardial contractility during heart failure, an animan model of heart failure was set up by means of deoxycorticosterone-acetate impregnated silicone rubber implants in wistar rats. Cardiac contractility in normal and heart failure rats was examined, and gene expression of its myocardial contractile protein, alpha-MHC, was quantitatively analyzed at gene transcription level by using RNA slot blot hybridization. The results showed that the cardiac contractility and the alpha-MHC mRNA levels in heart failure rats were all lower than those in the normal. Statistical analysis showed a positive correlation between the cardiac contractility and the gene expression of alpha-MHC (r = 0.4143, n = 43, P < 0.05). The above results indicate that gene expression level of alpha-MHC is one of the key factors determining cardiac contractility.

Animals↗
PubMed1998

[Reversal of cancer multidrug resistance by Chinese medicine Ams-11, Fw-13 and Tul-17].

The aim of this project was to find some kinds of Chinese materia medica as effective agents for in vitro reversal of cancer multidrug resistance. Based on the present authors' previous researches, thirty-two kinds of Chinese medicine as research meterials were selected and examined. Using cell growth inhibit assay, the authors found that three of them--Ams-11, Fw-13 and Tul-17 in the doses free from cytotoxity could enhance the sensitivity of multidrug resistant cells to anti-cancer drugs in a dose-dependent way. It seemed that these three kinds of Chinese medicine might be potential effective reversal agents.

Cell Survival↗
PubMed1998

[Qualitative and quantitative analyses of telomerase activity in cultured cells].

In this study, we established a qualitative PCR-TRAP assay by using SYBR Green stain instead of EB stain; this modification based on Kim's method raised the sensitivity of telomerase detection by 25-100 fold. Besides, a quantitative assay was established by us using 32P-ATP labeled TS primer and the internal control TSK1. We detected the telomerase activity of 12 cultured cells by means of these two assays. The results showed that the telomerase activity could be detected in all the cells, but the activity levels of the cells differed prominently (from 23 to 652 TPG units). The establishment of PCR-TRAP assay and especially the establishment of quantitative assay have enabled us to evaluate the telomerase activity of cells more accurately, and they can be used in our further studies of tumor gene therapy by reducing the telomerase activity of tumor cells.

Breast Neoplasms↗