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Biomedical subjects

J Qi

Publications and source records attributed to J Qi.

At least 91 records · Page 5Linked to original sources

[Studies on pyridonecarboxylic acids as antibacterial agents. XIV. Synthesis and structure-activity relationships of 7,8-disubstituted-1-cyclopropyl-6-methyl-1,4-dihydro-4-oxo-3-quinoline carboxylic acids].

Eighteen pyridonecarboxylic acids, characterized by a methyl group at the C6-position instead of the usual fluorine atom, cyclopropyl at the N1-position, substituted amino groups at the C7-position, and some substituted groups (hydrogen, chlorine, nitro and amino) at the C8-position, were synthesized. The in vitro antibacterial activity of these compounds were tested, and the structure-activity relationships were also discussed. The results of the study showed that the activity of compounds 22 and 24 were less potent than that of ciprofloxacin against S. aureus, S. epidermidis, E. coli and P. aeruginosa, while they were 2-100 times more potent than ciprofloxacin against K. pneumoniae, S. marcescens, A. calcoacetous, E. aerogenes, S. typhi and S. typhimurium.

Anti-Infective Agents↗

[Seroepidemiologic survey for A/PR/8/34 (H1N1) virus from Chinese residents].

A total of 414 serum specimens were collected from the residents with ages of < or = 20 year old in eight different parts of China for detecting antibody to A/PR/8/34(H1N1) influenza virus with HI test. Of them, 24 had antibody with HI titers > or = 20 to A/PR/8/34(H1N1) virus. These 24 specimens were tested with the same method using A/swine/Iowa/15/30 (H1N1), A/Guangxi/10/94(H1N1) and A/Beijing/53/97(H1N1) viruses. The results showed that except 5 of them had antibody with HI titers 20-40 to A/Beijing/53/97(H1N1) virus, the rest had antibodies with titers < 20 to the viruses for checking test. Therefore, the antibody to A/PR/8/34(H1N1) virus in the tested sera was not caused by cross reaction of antibodies against another H1N1 viruses. The results in this paper also further demonstrated that the A/PR/8/34(H1N1) like virus was circulating in residents in China.

Adolescent↗

[Genetic relationships of Nyctereutes procyonopides: as inferred from random amplified polymorphic DNA analysis].

Random amplified polymorphic DNAs (RAPDs) were used to investigate genetic relationships of eight raccoon dogs (Nyctereutes procyonopides). Using 28 arbitrary primers (10 bp), about 130 RAPD markers were observed in each individual. The average, maximum, and minimum genetic distance among 8 raccoon dogs are 11.20%, 14.93%, and 2.94% respectively. Our molecular phylogenetic trees constructed by UPGMA and NJ methods suggest that those 8 Chinese raccoon dogs may be divided into 4 clusters: (1) Guangxi raccoon dog, (2) Anhui raccoon dog, (3) Shaanxi raccoon dog, (4) Yunnan and Vietnam raccoon dog. Guangxi raccoon dog is more closely related to Anhui raccoon dog than to Yunnan-Vietnam raccoon dog. If the Yunnan-Vietnam cluster is a valid subspecies, it is reasonable to give the Guangxi, Anhui and Shaanxi clusters the same classification status as that of the Yunnan-Vietnam Cluster.

Animals↗

Fibrin regulation of interleukin-8 gene expression in human vascular endothelial cells.

Recent studies in our laboratory, as well as others, have suggested that fibrin can regulate cell function in vitro and likely control inflammation in vivo by acting as a potent cell activator. This has led us to hypothesize that during tissue and vascular injury, fibrin can enhance leukocyte recruitment by inducing vascular endothelial cell expression of leukocyte chemotactic factors. To begin to test this hypothesis, we developed an in vitro model of in situ fibrin polymerization on human umbilical vein endothelial cell culture (HUVEC) and determined the ability of fibrin to induce HUVEC expression of the potent leukocyte chemotactic factor interleukin-8 (IL-8). Our initial studies showed that fibrin induced IL-8 expression in a time- and dose-dependent fashion. Fibrin-induced IL-8 expression in HUVEC could be seen as early as 2 hours post-fibrin stimulation. Additionally, fibrin concentrations as low as 30 microg/mL stimulated a detectable level of IL-8 antigen expression from HUVEC. We also showed that this fibrin induced IL-8 had the identical molecular weight and similar antigenic identity as recombinant and monocyte derived IL-8. Northern blot analysis showed that the IL-8 antigen increase seen in fibrin treated HUVEC was due to fibrin induced elevation of steady state mRNA expression in HUVEC. These data clearly support our hypothesis that fibrin is a potent vascular endothelial cell (VEC) activator that can directly contribute to leukocyte recruitment and activation by inducing leukocyte chemotactic factor expression from VEC.

Cells, Cultured↗

Fibrin induction of tissue factor expression in human vascular endothelial cells.

BACKGROUND: For the present study, we hypothesized that fibrin is an inducer of tissue factor (TF) expression in vascular endothelial cells in vitro and in vivo. METHODS AND RESULTS: To test the in vitro aspect of this hypothesis, human umbilical vein endothelial cells (HUVECs) were cocultured with physiologically relevant concentrations of fibrin (0.03 to 1.0 mg fibrin/mL) for various times (0.5 to 24 hours), and TF expression was compared with that in unstimulated HUVECs (media control). Results demonstrated that fibrin induced a time- and dose-dependent increase in TF antigen expression, functional TF procoagulant activity, and TF mRNA in HUVECs. CONCLUSIONS: These studies demonstrate that fibrin can directly regulate TF expression in HUVECs in vitro.

Blotting, Western↗

Fibrin induction of ICAM-1 expression in human vascular endothelial cells.

In acute and chronic inflammatory processes, fibrin deposition, and leukocyte accumulation are classic histopathologic hallmarks. Previous studies have shown that fibrin and fibrin degradation products can have biologic effects on vascular endothelial cells and can induce the expression of several endothelial cell-derived factors that may be important in regulating inflammation and tissue repair. We now demonstrate that coculture of human vascular endothelial cells (EC) with fibrin results in the up-regulation of intercellular adhesion molecule-1 (ICAM-1), thus providing a first link between fibrin deposition and adhesion molecule expression, which may lead subsequently to leukocyte accumulation and extravasation. Increased ICAM-1 expression was demonstrated by ELISA, flow cytometry, and functional adhesion assays. EC ICAM-1 expression increased in a time and dose response fashion. Cell surface levels of ICAM-1 induced by fibrin were comparable to, or exceeded, levels induced by IL-1beta. ICAM-1 expression increased beginning at 4 h post-fibrin formation with sustained elevated expression at 48 h. Fibrin-stimulated EC also bound increased numbers of polymorphonuclear neutrophils in cellular adhesion assays. This increase in adhesion could be blocked by Ab to ICAM-1. Inhibition of fibrin polymerization also inhibited the up-regulation of ICAM-1. Culture medium from fibrin-stimulated EC contained elevated levels of soluble ICAM-1. These data suggest that fibrin deposition on vascular EC, in addition to other reported effects on EC metabolism, may also lead to leukocyte accumulation and extravasation through the induction of leukocyte adhesion molecules such as ICAM-1.

Cell Adhesion↗

Reciprocal regulation of the content of aromatic L-amino acid decarboxylase and tyrosine hydroxylase mRNA by NGF in PC12 cells.

Aromatic L-amino acid decarboxylase (AADC) and tyrosine hydroxylase (TH) are involved in the synthesis of dopamine and other monoamine neurotransmitters, and their activities can be regulated by a number of physiological stimuli. An interesting finding has been that (-)-deprenyl and some other irreversible monoamine B oxidase inhibitors increase AADC gene expression and that these compounds can exert neuronal protection/rescue effects. In this study, we have investigated the effects of nerve growth factor (NGF), and of (-)-deprenyl on AADC and TH gene expression in PC12 cells. Cells were treated with different doses of NGF (0.2-50 ng/ml) for up to 3 days. Northern and blot hybridizations were performed to detect AADC and TH mRNA. The results show that NGF can down-regulate AADC gene expression while increasing TH gene expression in a time- and dose-dependent fashion. Treatment with (-)-deprenyl alone increases the gene expression of AADC, and (-)-deprenyl further counteracts the reductions induced by NGF. This study introduces novel results with regard to the regulation of the gene expression of AADC in PC12 cells, which is not paralleled by the other catecholamine biosynthetic enzymes. These findings support the existence of an interaction between NGF and AADC gene expression that may be associated with the process of neuronal degeneration or regeneration.

Animals↗

Two cytotoxic pathways of natural killer cells in human cord blood: implications in cord blood transplantation.

Using K562 cells as a target we investigated cord blood (CB)-natural killer (NK) cytolytic pathways. The cytotoxicity of fresh CB-NK cells was significantly lower than that of peripheral blood mononuclear cells (PB MNCs). When CB was incubated with IL-2, the level of CB-NK cytotoxicity was increased and boosted to the level observed in PB-NK cells. Fresh CB-NK cells induced apoptosis in target cells. Activated CB cells induced apoptosis and necrosis in target cells, at the same level as PB MNCs. CB stem cell transplantation may also induce graft-versus-host disease (GVHD)/graft-versus-leukaemia (GVL), similar to bone marrow transplantation.

Apoptosis↗

Eltanolone as an alternative to propofol for ambulatory anesthesia.

UNLABELLED: The intravenous (i.v.) steroid anesthetic, eltanolone, compares favorably to propofol with respect to its induction characteristics. This double-blind investigation was designed to compare the induction and recovery profile of eltanolone (versus propofol) when it was used for both induction and maintenance of ambulatory anesthesia. Eighty-three consenting ASA physical status I-III outpatients undergoing minor gynecologic or urologic procedures lasting 10-40 min were randomly assigned to one of three anesthetic treatment groups. All patients received midazolam, 2 mg i.v., and fentanyl, 50 micrograms i.v., before induction of anesthesia. The control group (Group 1) was induced with propofol, 2.4 mg/kg i.v. (18-60 yr or ASA physical status I or II) or 1.6 mg/kg i.v. (61-80 yr and/or ASA physical status III), followed by intermittent bolus doses of 0.6 mg/kg i.v. in combination with N2O 67% for maintenance of anesthesia. In Group 2, anesthesia was induced with eltanolone, 0.75 mg/kg i.v., (18-60 yr and/or ASA physical status I or II) or 0.5 mg/kg i.v. (61-80 yr and/or ASA physical status III), and maintained with intermittent bolus injections of 0.2 mg/kg i.v. and N2O 67%. Group 3 received eltanolone, 1.0 mg/kg i.v. (18-60 yr and/or ASA physical status I or II), or 0.75 mg/kg i.v. (61-80 yr and/or ASA physical status III), followed by intermittent bolus injections of 0.2 mg/kg i.v. and N2O 67%. In addition to recording the induction and recovery times and side effects, psychomotor testing was performed before and at 30-min intervals after anesthesia. Induction times (57 +/- 23, 67 +/- 26, and 61 +/- 22s, respectively) were similar in all three groups. Although eltanolone produced no pain on injection (versus 52% in the propofol group), 10% of the eltanolone-treated patients (versus none in the propofol group) developed transient cutaneous (rash-like) reactions. The total dose of study medication used during the anesthetic period was 9.2 +/- 3.7 mg.kg-1.h-1 in the propofol group compared with 3.3 +/- 1.4 mg.kg-1.h-1 and 3.3 +/- 1.9 mg.kg-1.h-1 in Groups 2 and 3, respectively. Early recovery times were significantly shorter after propofol anesthesia. However, times to ambulation, micturition, and being judged "fit for discharge," as well as recovery of cognitive function, were similar in all three groups. Although ethanolone seems to be a safe and effective i.v. anesthetic, these data suggest that it is unlikely to replace propofol in the ambulatory setting. IMPLICATIONS: Eltanolone is an investigational steroid anesthetic that causes less pain on injection and less cardiovascular depression than propofol (the most widely used intravenous anesthetic in the outpatient setting). Unfortunately, emergence from anesthesia after ambulatory surgery is slower with eltanolone compared with propofol. Therefore, it is unlikely that eltanolone will replace propofol for outpatient anesthesia.

Adult↗

Cytotoxic T-lymphocytes recognizing P-glycoprotein in murine multidrug-resistant leukemias.

A multidrug-resistant murine lymphoid leukemia P388/ADR overexpresses P-glycoprotein (P-gp), an active transporter that pumps cytotoxic drugs out of cells and a product of mdr1 gene. Cytotoxic T lymphocytes (CTL) that showed cytotoxicity against P388/ADR were generated from mixed lymphocyte tumor cell culture. CTL do not kill drugsensitive parental P388 (P388/parent) that does not express P-gp. Monoclonal antibody against P-gp inhibited cytotoxic activity. Similar results were obtained in another multidrug-resistant cell line P388/VP-16. Cytotoxic activity was mediated by Thy1+ CD4- CD8+ T-cells. When P388/ADR was treated with murine IL-4, expression of P-gp was downregulated. Monoclonal antibody against interleukin-4 (IL-4) abrogated the IL-4-induced suppression of P-gp. Cytolytic activity of CTL against IL-4-treated P388/ADR was dose dependently inhibited. These results suggest that P-gp is immunogenic and can be a target of CTL in this murine leukemia model.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[The plant regeneration of Salvia miltiorrhiza Bge. transformed by Agrobacterium].

The hairy roots and crown galls of Salvia miltiorrhiza were obtained by infecting plant with A. rhizogenes (strain 15834, LBA 9402) and A. tumefaciens (strain C58). The transformed plants were regenerated light and transplanted form cultural medium into soil successfully. The plants transformed by A. rhizogenes have characteristics of short stems and develop hairy roots, those and trans formed by A. tumefaciens grow vigorously featuring, longer stems and well developed roots. Both biomass production and tanshenone content are higher than the original plant.

Agrobacterium tumefaciens↗

[Discovery of a novel reassortant H1N2 influenza virus].

Three strains of influenza A virus were isolated from patients suffering from influenza like disease in Railway Hygiene and Anti-epidemic Station of Taiyuan in January 1996. The identification results by serological method indicated that the isolates were different from H1N2 subtype of influenza A virus isolated from men in 1989 and 1992 and that their HA antigenicity was similar to that of A/RP/8/34 (H1N1) virus, but distinguishable from that of influenza A (H1N1) virus circulating in mans recently. The comparison of migration patterns of the RNA among the isolates, the A/PR//34 (H1N1) and the A/Wuhan/359/95 (H3N2) viruses revealed that the migration patterns of RNA 1-4 segments of the isolates were similar to those of A/PR/8/34 (H1N1) virus, but those of RNA 5-6 segments were indistinguishable from those of A/Wuhan/359/95 (H3N2) strain. However, the migration patterns of RNA 7-8 segments of the isolates were not only different from those of A/PR/8/34 (H1N1) virus, but also distingrasgable from those of A/Wuhan/359/95 (H3N2) strain. Therefore, it could be considered that the isolates were a novel reassortant H1N2 influenza A virus.

Adolescent↗

[In vitro reversal of homoharringtonine resistance by the combination of tamoxifen and verapamil].

OBJECTIVE: To investigate the reversal of homoharringtonine (HHT)-resistance by tamoxifen (TAM) or verapamil (VER) alone or in combination. METHODS: The drug-sensitivity test was performed with semisolid agar culture. RESULTS: The cytotoxicity of HHT to K562/S cells was not enhanced by TAM or VER alone or in combination,but HHT resistance in HHT resistant cells (K562/H20) was reversed by VER and TAM at nontoxic doses (4micromol/L or 8micromol/L). The IC50 of K562/H20 for HHT decreased from 446.8 +/- 0.08microg/L to 45.1 +/- 0.02microg/L in the presence of 4micromol/L of VER, to 22.4 +/- 0.03microg/L in 8micromol/L of VER, to 85.1 +/- 0.03microg/L in 4micromol/L of TAM and to 26.4 +/- 0.02microg/L in 8micromol/L of TAM. In the presence of combinations of 2micromol/L VER and 4micromol/L TAM and of 2micromol/L VER and 8micromol/L TAM, IC50 of K562/H20 decreased to 30.4 +/- 0.02microg/L and 4.3 +/- 0.04microg/L, respectively. CONCLUSION: HHT-resistance could be reversed by VER or TAM alone, and the combination of the two drugs showed a synergistic effect.

Animals↗

[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↗

[Effects of antisense oligodeoxynucleotides targeting multidrug resistance gene on resistant cell line K562/ AO2].

OBJECTIVE: To investigate the reversal effect of antisense oligodeoxynucleotide on human multidrug-resistant leukemic cell line K562/AO2. METHODS: Antisense oligodeoxynucleotides (AOD) targeting-6 approximately 9 sites of exon 2 in human multidrug resistance gene(mdr-1), one of which is sequence-strict-complied and linked with polyethyleneglycol (PEG) at 5' end (AP, 15 mer), the other lacks nucleotide complied site-1 (AP', 14mer), were synthesized. AP, AP' and verapamil were simultaneously added to human mdr-1-mRNA positive leukemia cell line K562/AO2 and, mdr-1-mRNA and p170 were detected. AS' and AP'were labelled by FITC and designated as ASF' and APF', respectively. In addition, the intracellular concentration of them was detected by FACS. RESULTS: AP' significantly enhanced the sensitivity of K562/AO2 to DOX, down-regulated the expression of mdr-1 and MRP-mRNA and p170, elevated the intracellular concentration of the two AOD, while AP had no effect. The uptake of APF' was significantly higher than that of ASF' in K562/AO2, and the fluorescence was observed in the plasma and nuclear of K562/AO2 cells. CONCLUSION: (AOD targeting mdr-1 promoted the drug sensitivity of drug-resistant tumor cells. 2 AOD had no cytotoxicity to tumor cells. 5 Low molecule PEG enhanced significantly the uptake of AOD by tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Pharmacokinetic study on acetaminophen: interaction with a Chinese medicine.

To know the influences of a Chinese traditional medicine (KAKKONTO) on the metabolism of acetaminophen (APAP), we have carried out pharmacokinetic studies on APAP under KAKKONTO coadministration in humans and rats. In humans, the pharmacokinetic parameters were calculated from the blood APAP concentration-time curves of each volunteer. The parameters did not show any significant differences between the KAKKONTO-coadministration group (group K) and the APAP-administration group (group A). KAKKONTO, when given at two different doses, did not show any significant effects on blood APAP level. In rats, the blood APAP level was significantly higher than that of group A (p < 0.01) only in the 100 mg/kg of group K at 0.25 h after APAP administration. There were no other significant differences.

Acetaminophen↗

Selection of a high tanshinone-producing crown gall strain and production of tanshinone in the strain.

Crown galls were induced by direct infection of sterile seedlings of Salvia miltiorrhiza with Agrobacterium tumefaciens C58 and subcultured on a 67-V hormone-free medium by successively selecting red cell aggregates. A high tanshinone-producing crown gall strain C1 was obtained after 12 months in a subculture. It grows well and retains its high tanshinone-producing characteristic in liquid stationary cultures. It is obvious that the yeast extract and fermentation extract of Armillaria mellea as elicitors promote strain C1 to produce tanshinone. Tanshinone content of strain C1 cultures was over three times higher than that of the crude drugs. The results indicated that the crown gall tissue and elicitor technique could provide some new clues for the production of tanshinone under the condition of a liquid stationary culture.

Abietanes↗