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Biomedical subjects

Z Qiu

Publications and source records attributed to Z Qiu.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Expression of surfactant protein SP-A, SP-B, and SP-C mRNA in lungs of rats with bleomycin-induced pulmonary fibrosis].

OBJECTIVE: The expressions of surfactant protein (SP)SP-A, SP-B, and SP-CmRNA in lungs of rats with bleomycin-induced pulmonary fibrosis were studied. METHOD: A single dose of bleomycin(BLM) was intratracheal injected to induce pulmonary fibrosis of rats. Animals were killed at day 3, 7, 14 and 28 after BLM administration. The total RNA was extracted from the lung tissue. The expressions of SPsmRNA were analyzed with Northern blot. RESULT: The number of alveolar type II epithelial cells increased in BLM-administered rats. The expressions of SP-A, SP-B and SP-CmRNA decreased at day 3 after BLM administration and decreased maximally at day 7, and then began to increase at day 14 and significantly increased at day 28, though they were still below the control levels. CONCLUSION: The results show that the changes of expressions of SP-A, SP-B and SP-CmRNA occur during the development of bleomycin-induced pulmonary fibrosis in rats and they may play a role in the pathogenesis of lung fibrosis.

Animals↗
PubMed1998

[Expressions of TNF alpha, PDGF in alveolar type II epithelial cells of rats with bleomycin-induced pulmonary fibrosis].

OBJECTIVE: The expressions of TNF alpha and PDGF in alveolar type II epithelial cells of rats with bleomycin(BLM)-induced pulmonary fibrosis were studied. METHOD: A single intratracheal injection of BLM was administrated to induce pulmonary fibrosis of rats. Animals were killed at day 3,7,14 and 28 after BLM-administration. The immunohistochemical methods were used to analyze the expressions of TNF alpha and PDGF proteins in alveolar epithelium of rats. The total RNA was extracted from the alveolar type II epithelial cells of rats and the expressions of TNF alpha and PDGF mRNA were analyzed with Northern blot. RESULT: TNF alpha and PDGF were expressed in the alveolar type II epithelial cells of BLM-administrated rats. The expression of TNF alpha elevated in median and late-stage of the process and reached the peak at day 28. While the expression of PDGF elevated in early-stage and reached the peak at day 7. By contrast, TNF alpha and PDGF weren't expressed in the alveolar type II epithelial cells of normal controls. CONCLUSION: The results show that the alveolar type II epithelial cell from rats with pulmonary fibrosis overexpresses TNF alpha and PDGF and they may play roles in the pathogenesis of lung fibrosis.

Animals↗
PubMed1998

[Surgical treatment of aortopulmonary septal defect].

OBJECTIVE: To study the surgical treatment of aortopulmonary septal defect. METHOD: From January 1983 to December 1996, 5 patients with aortopulmonary septal defect (APSD) (2 male and 3 female) aged from 6 to 34 years (mean 17.4 years) underwent surgical treatment. According to Mori's were classification, 5 patients belonged to type I, 2 type II and 1 type III. The diameters of the defect ranged from 1.0 to 3.0 cm. The operations were performed under moderate hypothermic cardiopulmonary bypass. Pulmonary artery incision was performed, in 3 patients while aortic incision in the other 2. All defects were repaired by Dacron patch. RESULT: There were no operative deaths and postoperative complications. During follow-up of 10 months to 12 years, no late complications and deaths were found. CONCLUSION: The operation should be done early as possible whenever the diagnosis is established. The surgical repair should be taken under cardiopulmonary bypass. To chose an incision on the aorta is more reasonable than on the pulmonary artery. The use the dacron patch can prevent stenosis and recanalization after operation.

Adolescent↗
PubMed1998

[Effects of artemisia capillaris on blood glucose and lipid in mice].

The effects of Artemisia capillaris Thunb (AC) on blood glucose and lipid in mice were studied and its effective mechanism was explained. The results showed that hyperglycemic effect in aloxan-induced mice was inhibited (P < 0.01); that hyperglycemica in DM mice was decreased (P < 0.05); but the change of fasting blood glucose (FBG) in normal and hyperlipidemia mice was not significant (P < 0.05); that the level of total cholesterol (TC) and/or atherosclerotic index (AI) was decreased (P < 0.01-0.05) and the content of high density lipoprotein cholesterol (HDL-C) was increased in the above different model mice (P < 0.01-0.05). These results indicated that the AC would have the similar hypoglycemic effect as biguanide-drugs, improve endogenous and exogenous metabolic derangement in blood lipid. These suggest that AC could be used to protect and treat DM and its chronic complication.

Alloxan↗
PubMed1997

The Escherichia coli polB locus is identical to dinA, the structural gene for DNA polymerase II. Characterization of Pol II purified from a polB mutant.

Escherichia coli DNA polymerase II (Pol II) is a member of the group B, "alpha-like" family of DNA polymerases. Pol II is encoded by the damage-inducible dinA gene and exhibits SOS induction under the control of Lex A repressor. The polB gene was originally designated as the structural gene for Pol II based on the absence of detectable Pol II activity in cell lysates prepared from a strain containing the mutant polB100 allele. Because polB and dinA mapped at different chromosomal locations, it remained an open question whether polB, in addition to lexA, might be involved in regulating the expression of Pol II. We have cloned and sequenced the polB100 mutant allele, including adjacent surrounding sequences, and have expressed the mutant dinA gene from Pol B100 on a high copy number plasmid. Our sequence data reveal that polB and dinA represent the same gene and that the original transduction mapping of polB was inaccurate. We purified the mutant Pol B100 polymerase and show that it retains 5 to 10% of the wild-type level of polymerase activity. The Pol B100 mutation, Gly401 --> Asp401, is not located within any of the five conserved domains that define group B polymerases. Pol B100 retains a wild-type level of 3' --> 5' exonuclease activity. We suggest that the normal level of exonucleolytic proofreading associated with the mutant Pol B100 enzyme may explain the repeated failures, over the past two decades, to detect phenotypes in polB mutant strains.

Bacterial Proteins↗
PubMed1997

Escherichia coli DNA polymerase II catalyzes chromosomal and episomal DNA synthesis in vivo.

We have investigated a role for Escherichia coli DNA polymerase II (Pol II) in copying chromosomal and episomal DNA in dividing cells in vivo. Forward mutation frequencies and rates were measured at two chromosomal loci, rpoB and gyrA, and base substitution and frameshift mutation frequencies were measured on an F'(lacZ) episome. To amplify any differences in polymerase error rates, methyl-directed mismatch repair was inactivated. When wild-type Pol II (polB+) was replaced on the chromosome by a proofreading-defective Pol II exo- (polBex1), there was a significant increase in mutation frequencies to rifampicin resistance (RifR) (rpoB) and nalidixic acid resistance (NalR) (gyrA). This increased mutagenesis occurred in the presence of an antimutator allele of E. coli DNA polymerase III (Pol III) (dnaE915), but not in the presence of wild-type Pol III (dnaE+), suggesting that Pol II can compete effectively with DnaE915 but not with DnaE+. Sequencing the RifR mutants revealed a G --> A hot spot highly specific to Pol II exo-. Pol II exo- caused a significant increase in the frequency of base substitution and frameshift mutations on F' episomes, even in dnaE+ cells, suggesting that Pol II is able to compete with Pol III for DNA synthesis on F episomes.

Anti-Bacterial Agents↗
PubMed1997

[The curative effects of anti-TNF monoclonal antibody in E. coli infected mice].

OBJECTIVE: To evaluate effects of monoclonal antibody (McAb) against TNFa on E. coli infected mice. METHODS: 30 mice (10 week old, Kunming) were divided equally into three groups. The first group, as a control, 200 microliters saline (NS)/mouse was injected intravenously; Second group (untreated group), only E. coli (10(7) organisms/200 microliters NS) were injected intra-abdominaly; Third group (treated group), E. coli (10(7) organisms) were injected intra-abdominal and McAb against TNF alpha 2 mg/kg dissolved in 200 microliters NS were injected intravenously. After 24 h, observed the survival rate, compared the serum TNF level in blood and investigated pathology of intestine, lung and liver. RESULTS: There was a higher survival rate in treated group, with the serum TNF level lowered significantly, and the untreated mice had severe pathologic changes in viscera. CONCLUSION: Using anti-TNF alpha McAb was effective in reducing mortality rate in mice after infected with E. coli, but could not prevent the pathologic changes.

Animals↗
PubMed1997

The development of monoclonal antibody against rhTNF and its curative effects on E. coli infected mice.

Fifteen hybridoma cell lines producing monoclonal antibodies (McAb) against recombinant human tumor necrosis factor alpha (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from a BALB/c mouse immunized with rhTNFa. Following J. M. Davis's Works, semi-solid medium was used for initial cloning. Five of them were studied further. Their main chromosome numbers range were 96 to 105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1.25 x 10(8) mol/L, 1.12 x 10(8) mol/L, 2.34 x 10(8) mol/L, 8.55 x 10(7) mol/L, 1.04 x 10(8) mol/L, respectively. Two groups of mice challenging with E. Coli (10(7) organisms), one group treated with 2 mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serum TNF level was significantly lower too, and the untreated mice had severe pathologic changes in viscera.

Animals↗
PubMed1997

[Studies on difference of fluorescence activity and elution order of propranolol enantiomers by reversed-phase high performance liquid chromatography].

A sensitive RP-HPLC method for the determination of propranolol enantiomers was developed. It involves the formation of the monoester of propranolol with optically pure (R,R)-O,O'-diacetyl tartaric acid anhydride (DATAAN) in a dry, aprotic solvent with an excess of trichloroacetic acid. The resulting diastereomeric monoesters were easily resolved on a Shim-pack CLC-ODS column with the mobile phase system consisting of different proportions of 2% aqueous acetic acid (adjusted with concentrated ammonia to pH 3.48) and 90% aqueous methanol. And the column effluent was monitored by a fluorescence detector (lambda(ex) 296 nm, lambda(em) 340 nm). In our experiment, a very strong difference of the fluorescence absorbance of the two diastereomers was observed. After having studied chromatographic separation conditions including pH value, ionic strength and the volume percent of organic modifier in mobile phase, we presented the different configurations of the diastereomers and an intra-molecular hydrogen bond which exists only in the (R,R,S) isomer. These could account for the obvious difference of fluorescence activity of two diastereomeric monoesters and their elution order on the reversed-phase column. Our studies show that the intra-molecular hydrogen bond plays an important role on the polarity of the diastereomeric derivatives which determines their elution order and the fluorescence absorbance of the two diastereomers.

Chromatography, High Pressure Liquid↗
PubMed1997

Transmission factors of schistosomiasis japonica in the mountainous regions with type of plateau canyon and plateau basin.

OBJECTIVE: To provide the scientific basis for formulating the control strategies of schistosomiasis japonica in mountainous regions in China Schistosomiasis Control Programme. METHODS: We selected Chuanxing Village in Sichuan Province and Zhonghe Village in Yunnan Province as the two pilot areas for an epidemiological investigation according to their geographical and topographical characteristics, i.e. plateau canyon and plateau basin, respectively. Concentrated-egg hatching method in nylon tissue bag and Kato-Katz technique were used for the survey on prevalence rate and intensity of infection of man and domestic animals. Questionnaires were applied to investigating the infection sources, community behavior and the socioeconomic status. Snail survey and detection of cercaria-infested water bodies were conducted using routine techniques. RESULTS: The results showed that in the endemic areas with plateau canyon, the key infection source was cattle. The infection rate in women was higher than that in men. The pattern of water-pollution was wild feces and the pollution source was cattle feces. Snails and infectious snails were distributed over the rice fields and the resident was infected through production activities. In plateau basin, the key infection source was human beings. The infection rate in men was higher than that in women. The pattern of water pollution was fertilization. The pollution source was human feces. Snails and infectious snails were distributed over the canals and ditches and the resident was infected through production and daily activities. CONCLUSIONS: Therefore, it was suggested that the mountainous endemic areas should be divided into two sub-types, i.e., plateau basins and plateau canyons. The different control strategies should be formulated in accordance with the environmental situations and socioeconomic factors in the two kinds of endemic areas.

Adolescent↗
PubMed1996

Tyrosine kinase activation is an immediate and essential step in hypotonic cell swelling-induced ERK activation and c-fos gene expression in cardiac myocytes.

Hypotonic stress causes rapid cell swelling and initiates various cellular adaptive processes. However, it is unknown how cells initially sense low osmolarity and convert it into intracellular signals. We investigated the signal transduction mechanism initiated by hypotonic cell swelling in cardiac myocytes using c-fos expression as a nuclear marker. Treatment of myocytes with hypotonic culture media rapidly induced c-fos expression, whereas hypertonic stress had no effect. Transfection of c-fos reporter gene constructs suggested that the hypotonic stress response element maps to the serum response element of the c-fos promoter. Hypotonic stress immediately (within 5 s) activated tyrosine kinase activity, while activation of ERK1/2 peaked at 5 min. Stress-activated kinase (JNK1) was modestly activated at 15 min, whereas HOG1 like kinase (p38) was not activated by hypotonic stress. Extensive pharmacological studies indicated that only tyrosine kinase inhibitors suppressed the hypotonic swelling-induced c-fos expression. The effect of hypotonic stress was mimicked by chlorpromazine, which is known to cause membrane deformation. These results suggest that the signaling mechanism of hypotonic stress is distinct from that of hyperosmolar stress in mammalian cells. Tyrosine kinase activation is the earliest detectable cell response and plays an essential role in hypotonic swelling-induced ERK1/2 activation and c-fos expression.

Animals↗
PubMed1996

Oral HIV-I recovery in the presence of periodontal disease.

OBJECTIVE: To determine whether a significant association occurs between the presence of various periodontal diseases and recoverable infectious HIV-I in the saliva of injecting drug users. DESIGN: Five hundred and fifty-one injecting drug users were recruited from various programs associated with the Beth Israel Medical Center. Examiners were 'blinded' to the subject's HIV-I serostatus. A socio-economic and risk factors' survey was conducted and a complete oral examination, including periodontal disease indices was performed. Whole saliva and blood were collected for virus culture. MAIN OUTCOME MEASUREMENTS: Recovery of infectious HIV-I in saliva related to presence of periodontal diseases. RESULTS: Those HIV-I seropositive subjects with periodontal diseases did not differ from those HIV-I seropositive subjects without periodontal disease in mean age and immune status. Less than 1% of the HIV-I seropositive subjects had cultivable HIV-I in their saliva while it was present in 78% of PBMCs and 35% of the sera. There was no significant association between infectious HIV-I in saliva, serum, or PBMCs and any of the various periodontal diseases. CONCLUSIONS: The presence of periodontal disease in HIV-I seropositive injecting drug users does not appear to be a potential risk factor for infectious HIV-I in saliva, probably due to the various anti-viral components of saliva.

Adult↗
PubMed1996

Identification of domains in rubella virus genomic RNA and capsid protein necessary for specific interaction.

In rubella virus-infected cells, genomic 40S and subgenomic 24S RNAs are present in the cytoplasm of infected cells. However, encapsidation by rubella virus capsid protein is specific for 40S genomic RNA. As a first step toward understanding the assembly of rubella virus nucleocapsid at the molecular level, the interaction between capsid protein and genomic RNA was studied by Northwestern (RNA-protein) blot analysis. RNA probes prepared by in vitro transcription were used to localize the RNA sequence that participates in binding to the capsid protein. We have identified a 29-nucleotide RNA sequence (nucleotides 347 to 375) that is essential for the binding. By using overlapping synthetic peptides of capsid protein, a peptide domain (residues 28 to 56) that displays specific RNA-binding activity of capsid protein has been located. This result suggests that the specific recognition of viral RNA during rubella virus assembly involves, at least in part, the nucleocapsid protein.

Amino Acid Sequence↗
PubMed1996

Cholinergic stimulation modulates negative inotropic effect of cocaine on ferret ventricular myocardium.

We tested the hypothesis that the negative inotropic effect (NIE) of cocaine is mediated, at least in part, by cholinergic stimulation and can be correlated with the degree of adenosine 3',5'-cyclic monophosphate (cAMP) dependency of the inotropic state. Cardiac myocytes were isolated from left ventricles of ferrets and loaded with the fluorescent Ca2+ indicator indo 1. Cells were placed in physiological solution containing 2.0 mM Ca2+ and stimulated at 0.5 Hz and 30 degrees C. Cocaine decreased peak cell shortening and peak intracellular Ca2+ in a concentration-dependent manner (10(-8)-10(-4) M). The concentration-response curve of cocaine was shifted significantly downward compared with those of lidocaine and procaine in the same range of concentrations. Atropine (10(-6) M) shifted the concentration-response curve of cocaine, but not those of lidocaine and procaine, rightward, with a pA2 value (7.66) similar to that obtained with carbachol (7.99). With prior addition of isoproterenol (ISO, 10(-8) M) or increased Ca2+ (4.0 mM) to increase cell shortening to the same degree (approximately 60%), cocaine and carbachol decreased contractility to a significantly greater extent in ISO-stimulated myocytes. To clarify whether these treatments changed responsiveness of the contractile elements to Ca2+, the effect of 2,3-butanedione monoxime, an agent that interferes with the interaction of myosin and actin, was tested with previous addition of ISO or increased Ca2+, and no differential effect occurred. Therefore, we postulate that 1) the NIE of cocaine on myocytes is caused by decreased Ca2+ availability; 2) this effect is due to specific stimulation of cholinergic receptors in addition to other direct myocardial (probably local anesthetic) effects; and 3) the NIE correlates with the level of cAMP dependence of the inotropic state.

Animals↗
PubMed1996

Active expression of G gamma globin gene on chromosome 11 with Yunnanese A gamma delta beta)0-thalassemia deletion in MEL cells.

A permanent lymphocyte cell line of a heterozygote with Yunnanese (A gamma delta beta)0-thalassemia deletion, associated with an increased production of G gamma globin in adult, was founded using Epstein-Barr virus transformation. The hybrids of the lymphocyte cell and mouse erythroleukemia cell (MEL) were achieved and the hybrids containing human chromosome 11 were selected with the monoclonal antibody 53/6. The subclones containing only either the normal or the abnormal human chromosome 11 were separated and the expression of the human globin genes was studied. Expression of the beta-globin gene, but not the G gamma and A gamma, was observed in the hybrids containing only the normal human chromosome 11, while active expression of the G gamma globin gene was observed in the hybrids containing only the abnormal human chromosome 11. These results have confirmed that the DNA deletion in the beta-globin gene cluster is the cause of persistent active expression of the G gamma globin gene in the Yunnanese mutant.

Adult↗
PubMed1995

Brefeldin A and monensin arrest cell surface expression of membrane glycoproteins and release of rubella virus.

The maturation of rubella virus (RV) glycoproteins E2 and E1 was examined by using brefeldin A (BFA) and monensin. BFA, which induces the rapid redistribution of Golgi enzymes residing in the Golgi complex into the endoplasmic reticulum (ER), was used to locate the intracellular site for the modification of carbohydrate side-chains on RV E1 and E2 proteins. The monovalent ionophore monensin, which inhibits intracellular transport of proteins through the ER-Golgi complex, was used to block the transport of E1 and E2 glycoproteins through the Golgi complex. BFA and monensin effectively blocked the cell surface expression of RV E2 and E1 proteins, secretion of an anchor-free form of E2 and budding of RV from the plasma membrane. For O-linked glycosylation, addition of N-acetylgalactosamine and galactose to E2 protein was found to take place in the medial to the trans Golgi. A dramatic change in the intracellular distribution of RV structural proteins was observed when transfected COS cells were treated with BFA or monensin, although the proteolytic processing of RV structural protein precursor was not affected. In the presence of BFA or monensin, virus release from infected Vero cells was only 0.1% of the intracellular virus, and the intracellular virus titre decreased as well. Our results suggest that O-linked glycosylation on the E2 protein occurred in the post-ER region and the transport of RV structural proteins to the Golgi complex and post-Golgi compartment may be a rate-limiting step in RV assembly and budding.

Animals↗