Animals ; Epilepsy ; genetics ; metabolism ; Genes, MDR ; Hippocampus ; drug effects ; metabolism ; Male ; Rats ; Rats, Wistar ; Triazines ; pharmacology

Background: Acute lower respiratory tract infection, mainly pneumonia, were the main reasons cause death for children under 5 years old. Objectives: Determine the isolated rate of bacteria inpatients under 5 years old with acute lower respiratory tract infection in Ha Noi and antibiotic resistance of pneumococcal isolated form patients. Subjects and method: Patients under 5 years old with acute lower respiratory tract infection in National hospital of pediatrics and Bach Mai hospital from 01/2002. Using quantitative culturedand PCR method. Results: Out of total 164 patients with lower respiratory tract infection, there were 91 diagnosed pneumonia by chest X-ray, 73 cases of acute bronchitis. 73,6% of the pneumococcal isolated were penicillin resistance (gPRSP) with different genes such as pbp 1a+2x+ab. Most of the S.pneumoniae strains were serotype 19F or 23F. There were no statistic differences by comparison charactersistics of weight, vessel, subclinical symptoms such as: dissolved oxygen level (S\xac\xacp\xac\xac\xac\xacO\xac2\xac), the amount of leucocyte in blood. However, temperature of pneumonia patients was higher than bronchitis patients, breathing of pneumonia patients was also faster than bronchitis patients. Isolated bacteria with amount \ufffd?106 cfu/ml was H.influenzae, S.pneumoniae and Moraxell catarrhalis in pneumonia group, bronchitis group was 28,8% and control group was 17,1%. Conclusion: Penicillin, erythoromycin and co-trimoxazole resistance rate of S.pneumoniaein patients with acute lower respiratory tract infection was high. Quantitative cultured method has prognostic value in diagnosis pneumonia.
Genes ; MDR/ drug effects ; immunology ; Streptococcus pneumoniae/ growth & ; development ; Anti-Bacterial Agents

BACKGROUNDThe hematopoietic microenvironment (HM) plays a critical role in malignant cell growth, patient survival, and response to chemotherapy in hematologic malignancies. However, mechanisms associated with this environmental influence remain unclear. In this study, we investigated the role of bone marrow derived mesenchymal stem cells (MSCs) in U937 cell line, to find out the relations between leukemia drug resistance and the MSCs.

METHODSU937 cells were cultured in suspension or grew adherently with MSCs. The cell growth curve was drawn and the cell cycle was measured by flow cytometry. Apoptosis and sensitivity of U937 to daunoblastina (DNR) were quantified by DNA ladder detection and trypan blue exclusion assays, respectively. The gene expression profile chip technology was used to determine and analyze the changes in apoptosis-related gene expression after adherent culture and the expression of MDR1 mRNA was assessed by reverse transcriptional polymerase chain reaction (RT-PCR) at the same time.

RESULTSIn the adherent culture, the proliferation of the U937 cells was inhibited, the G0/G1 phase cells increased (F = 64.9726, P < 0.0001), G2/M phase cells were decreased (F = 98.1361, P < 0.0001) and the natural apoptosis rate was decreased (F = 24.0866, P < 0.0001) compared with those in the suspended culture. U937 cell viability was enhanced and cell apoptosis was blocked during DNR treatment in adherent culture with MSCs. Thirty-nine differently expressed genes were screened from the 487 apoptosis related genes in the adherent culture U937 cells. Among the 37 upregulated genes, Bcl-XL was upregulated most significantly. Two genes were downregulated. Adherent culture did not induce MDR1 mRNA expression in U937 cells.

CONCLUSIONSMSCs play a role in modulating the proliferation of U937 cells and response of U937 cells to DNR, and Bcl-XL apoptosis-inhibiting gene may be most important in determining the sensitivity of leukemic cells to treatment, which is not related to MDR1.

Apoptosis ; drug effects ; Bone Marrow Cells ; physiology ; Cell Proliferation ; Daunorubicin ; pharmacology ; Drug Resistance, Neoplasm ; Genes, MDR ; Humans ; Immunophenotyping ; Mesenchymal Stromal Cells ; physiology ; U937 Cells ; drug effects

OBJECTIVETo investigate the apoptosis-induction, P-glycoprotein (P-gp) and mdr1 mRNA inhibition effects of arsenic trioxide (As2O3) and buthionine sulfoximine (BSO) on multidrug-resistant cell line K562/ADM cells, and to determine the relationship between intracellular GSH content and arsenic effect.

METHODSK562/ADM cells were treated with arsenic (0.5, 2.0, 5.0 micromol/L) alone or combined with BSO (100 micromol/L). The cell proliferating capacity was assessed with MTT assay, and cell apoptosis by Annexin V and propidium iodide (PI) staining. Intracellular GSH contents were measured using a glutathione assay kit by spectrophotometry. P-gp expression was determined by flow cytometry, and mdr1 mRNA expression by semi-quantitative RT-PCR.

RESULTSThe GSH contents in K562/ADM cell was (81.13 +/- 3.91) mg/g protein. After the GSH contents were degraded by BSO, the K562/ADM cell proliferating capacity was obviously inhibited and the cells were induced apoptosis in 24 hours by the combination of clinic dose arsenic group (0.5, 2.0 micromol/L) and BSO (100 micromol/L). The cell apoptosis rates at 48 hours in arsenic alone group and combination group were (59.29 +/- 6.01)% and (65.06 +/- 8.29)%, and at 72 hours were (82.15 +/- 9.28)% and (92.72 +/- 9.41)% retrospectively. At 48 hours, the mdr1 mRNA inhibition effect of the combination group was obviously stronger than that of high dose arsenic alone group. At 72 hours, the P-gp inhibition effect of the combination group (clinic dose arsenic group, 0.5, 2.0 micromol/L) was obviously stronger than that of high dose arsenic alone group (5.0 micromol/L).

CONCLUSIONThe intracellular GSH contents are closely correlated with the arsenic effect. The combination of conventional dose arsenic and BSO significantly induces K562/ADM cell apoptosis and inhibits P-gp and mdr1 mRNA expression in the cells.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Buthionine Sulfoximine ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Genes, MDR ; drug effects ; Glutathione ; metabolism ; Humans ; K562 Cells ; Oxides ; pharmacology

OBJECTIVETo investigate the effects of arsenic trioxide (As(2)O(3)) on the apoptosis and p-glycoprotein (P-gp) expression of multidrug-resistant human leukemia cells.

METHODSHuman multidrug-resistant leukemia cell line K562/ADM overexpressing the MDR1 gene, was used as the target cells. The cell proliferating activity was assessed using the MTT colorimetric assay. Cytomorphology was investigated under light, confocal and electron microscopes. DNA fragmentation was examined using agarose gel electrophoresis, while p-gp expression, cell cycle status and sub-G1 cells were determined using flow cytometry.

RESULTSZero point five to 20 micromol/L As(2)O(3) inhibited the proliferation of K562/ADM cells, and K562/ADM cells were more sensitive to As(2)O(3) than the parental K562 cells. As(2)O(3)-induced apoptosis of K562/ADM cells was determined by the observance of typical morphological changes and the appearance of DNA ladder and sub-G1 cell populations. As(2)O(3) significantly inhibited the P-gp expression of K562/ADM cells, and synergistically enhanced the sensitivity of the drug-resistant cells to adriamycin.

CONCLUSIONSAs(2)O(3) induces growth-inhibition and apoptosis, down-regulates P-gp expression and exerts a synergistic effect in combination with adriamycin in multidrug-resistant leukemia cells.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; Apoptosis ; drug effects ; Arsenicals ; pharmacology ; Drug Resistance, Multiple ; Gene Expression ; Genes, MDR ; Humans ; Leukemia ; genetics ; metabolism ; Oxides ; pharmacology

OBJECTIVETo investigate the effect of small interference RNA (siRNA) on mdr1 and P-glyco-protein (P-gp) expression of multi-drug resistance (MDR) human leukemia cell line K562/A02.

METHODSThree si RNAs (si-mdr1-1, si-mdr1-2, si-mdr1-3) which were specifically targeted mdr1 gene were synthesized and transfected into K562/A02 cells. Expression of mdr1 mRNA was assayed by RT-PCR. P-gp expression and intracellular daunorubicin (DNR) concentration were determined by flow cytometry. 50% inhibition concentration (IC(50)) of doxorubicin (ADM) on K562/A02 was determined by MTT method.

RESULTSTreatment of K562/A02 cell with the 3 kinds of siRNAs resulted in a reversal of MDR of a different extent. The third siRNA was more effective in the suppression of mdr1 with a significant reduction of (58.0 +/- 1.54)% of the mdr1 mRNA expression. Positive expression rate of p170 decreased from (76.0 +/- 1.0)% to (19.6 +/- 1.9)%, and the relative efficiency of K562/A02 to ADM was 70.4%. The intracellular accumulation of DNR increased after siRNA treatment.

CONCLUSIONThe siRNA could effectively restore the sensitivity of K562/A02 cells to conventional chemotherapeutic agents.

Base Sequence ; Daunorubicin ; pharmacokinetics ; Drug Resistance, Neoplasm ; Genes, MDR ; physiology ; Humans ; K562 Cells ; drug effects ; Molecular Sequence Data ; RNA, Messenger ; analysis ; RNA, Small Interfering ; pharmacology

OBJECTIVETo study the reverse effect of ligustrazine (TMP) on HepG2/ADM, a herd of hepatocellular carcinoma cell, multidrug resistance (MDR) and the influence of P-gp170 expression.

METHODThe reverse effect of ligustrazine on HepG2/ADM cell was observed, with the methods of cell culture, MTT's analyze, RT-PCR and Flow cytometric, etc.

RESULTLigustrazine could make MDR of cell line of HepG2/ADM reduce the expression of P-gp170, enhance the density of adriamycin in cell and increase the adriamycin's cytotoxicity. With the Flow cytometric, the results of RT-PCR showed the transcriptional activity of the MDR1 decreased.

CONCLUSIONLigustrazine can reverse MDR of HCC cell line of HepG2/ADM and has prospect in clinical use.

Calcium Channel Blockers ; pharmacology ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; drug effects ; Doxorubicin ; metabolism ; pharmacology ; Drug Resistance, Multiple ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Genes, MDR ; Glycoproteins ; metabolism ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Pyrazines ; pharmacology

OBJECTIVETo observe the lethal effect of multidrug resistance gene (MDR1) antisense RNA combined with oxaliplatin and 5-FU on drug-resistant rectal carcinoma cells.

METHODSPC-MDR1 plasmid including MDR1 was constructed with gene cloning techniques. The drug-resistant cancer cells (8348R) were transferred with the plasmids, and the positive neoplasm cells were selected with G418. Green fluorescent protein (GFP) gene was used as a reporting gene to monitor the gene transfer efficiency under the influence of oxaliplatin and 5-FU. The cytotoxicity and therapeutic effects of MDR1 anti-sense RNA combined with oxaliplatin and 5-FU were evaluated by colony-forming rate and MTT assay.

RESULTSA significant decrease of biological activity was observed in 8348R cells transferred with PC-MDR1, cell cycles were blocked in S phase, or in G2/M phase, and apoptosis rate of the cells increased. With treatment of oxaliplatin, the plasmid transfer efficiency in the drug-resistant cancer cells was improved about 18 times. Using an IC(50) dose of oxaliplatin and 5-FU combined with (MDR1) anti-sense RNA, 75 percent of 8348R cells were killed, which was significant higher than that of the control cells.

CONCLUSIONSCombined MDR1 antisense RNA with oxaliplatin and 5-FU has a synergistic effect of killing drug-resistant cancer cells and may be a promising method for treating drug-resistant rectal carcinoma.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Combined Modality Therapy ; Drug Synergism ; Fluorouracil ; pharmacology ; Genes, MDR ; genetics ; Genetic Therapy ; Humans ; Organoplatinum Compounds ; pharmacology ; RNA, Antisense ; genetics ; Rectal Neoplasms ; genetics ; pathology ; therapy ; Transfection

To produce leukemic STI571-resistant cell lines and to explore the molecular mechanism of STI571-resistance, cell lines K562-n and K562-n/VCR were induced by exposing cells to gradually increasing STI571 concentration of culture medium to have STI571-resistance and major biological characteristics between these subclones and the parent cells were compared. The results showed that a STI571-resistant cell line based on multidrug-resistance was established, which exhibited 23.41-fold resistance to STI571, 662.26-fold resistance to VCR and cross-resistance to HHT. K562-n/STI was generated from K562-n and had some characteristics of MDR. The intracellular accumulation of DNR in K562-n/STI and K562-n/VCR/STI were 33.24 and 18.76 respectively. Transcription of mdr-1 gene in both K562-n/STI and K562-n/VCR/STI was positive. Cell doubling time of K562-n/STI and K562-n/VCR/STI was significantly longer than that in their parent cells (P <0.05). And proliferation index was also higher than that in parent cells (P <0.05). It is conclusion that the tolerance of K562-n cells to STI571 can be augmented by adding low-dose of STI571 into the culture medium repeatedly. K562-n/STIs expressed MDR at some extent, and transcription of mdr-1 gene in K562-n/STIs was positive. As K562-n is a cell line used to develop human leukemia in nude mice, K562-n/STI and K562-n/VCR/STI 571 will contribute to the study of mechanism of STI571-resistance as in vitro and in vivo experimental models.
Antineoplastic Agents ; pharmacology ; Benzamides ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Drug Resistance, Neoplasm ; Genes, MDR ; Humans ; Imatinib Mesylate ; K562 Cells ; Piperazines ; pharmacology ; Pyrimidines ; pharmacology ; RNA, Messenger ; analysis

The role of multidrug resistance (MDR1) gene in the activation of volume-activated chloride currents in bovine pigmented ciliary epithelial (PCE) cells was investigated by the patch-clamp technique, the antisense approach, the immunofluorescent technique and the confocal microscopy. PCE cells express P-glycoprotein (P-gp, the product of MDR1 gene). An MDR1 antisense oligonucleotide suppressed MDR1 expression (93% reduction of P-gp immunofluorescence), delayed the activation of a volume-activated chloride current (latency prolonged by 109%), reduced the activation rate by 62% and decreased the peak value of the current by 56%. The transfection reagent lipofectin and the mismatch control oligonucleotide did not significantly affect the current. The data indicate that the volume-activated chloride current is associated with the endogenous expression of MDR1 gene in PCE cells.
ATP-Binding Cassette, Sub-Family B, Member 1 ; biosynthesis ; Animals ; Cattle ; Cells, Cultured ; Chloride Channels ; physiology ; Ciliary Body ; cytology ; physiology ; Epithelial Cells ; metabolism ; physiology ; Gene Expression ; drug effects ; Genes, MDR ; physiology ; Oligonucleotides, Antisense ; pharmacology