Microtubule network provides many intracellular microbes with an efficient way to move within host cells. Orientia tsutsugamushi move from the cell periphery to the microtubule organizing center (MTOC) by dynein-dependent mechanism. In this study, we investigated the role of microtubule on the growth of O. tsutsugamushi. The treatment of infected cells with taxol as well as daunomycin enhanced the bacterial growth in contrast to colchicine. Immunofluorescent (IF) staining of taxol-treated cells exhibited that O. tsutsugamushi clustered tightly near the nucleus with thick bundles of microtubules, whereas dispersed in the cytoplasm in colchicine-treated cells. These results suggest that microtubule network facilitate the growth of O. tsutsugamushi.
Colchicine ; Cytoplasm ; Daunorubicin ; Microtubule-Organizing Center ; Microtubules ; Orientia tsutsugamushi* ; Paclitaxel

Inspite of technical advances, the need for pharmacologic treatment of proliferative vitreoretinopathy was increased. In order to evaluate the antiproliferative effect of various antimetabolites to the rabbit retinal pigment epithelial cell, we treated cultured rabbit retinal pigment epithelial cell with different concentration of drugs to perform dose inhibition studies. We found that the antimetabolites inhibited the proliferation of rabbit retinal pigment epithelial cell in a dose dependent and a time dependent manner. The drug concentration required for 50% inhibition of cell growth (ID50) were found to be as follows (BCNU; 6.51 mg/L, 5-FU ; 8.94 mg/L, Daunorubicin; 0.03mg/L, Mitomycin-C; 0.26mg/L).
Antimetabolites* ; Daunorubicin ; Epithelial Cells* ; Fluorouracil ; Mitomycin ; Retinaldehyde* ; Vitreoretinopathy, Proliferative

One of the most serious complications following strabismus surgery is the formation of adhesions that may result in restrictive ocular motility dysfunction. Management of the postoperative adhesions is often difficult. We investigated the effect of mitomycin c(MMC) and daunorubicin(DR) on postoperative would healing in rabbit extraocular muscle surgery after single intraoperative application. Sixteen white rabbits(32 eyes), weighing 2.0~2.5kg were used. These rabbits were divided into 4 groups; control group(BSS for 5 minutes exposure), group 1 (0.5mg/ml MMC for 1 minute exposure), group 2 (0.5mg/ml MMC for 5 minutes exposure), and group 3(25microgram/ml DR for 5 minutesexposure). Histopathologically, there was a more significant reduction of fibroblast and collagen fiber proliferation in group 1 and 2 than the control group. In group 3, these effects were better than the control group, but less than group 1 or 2. Immunohistochemically, group 1 and 2 showed greater effects of fibroblast growth factor (FGF) than the control group. In group 3, less effect was shown than group 1 or 2, but no difference was noted compare with the control group. These results suggest that intraoperative application of mitomycin c in strabismus surgery can increase a surgical success rate. However, daunorubicin is still controversial and more studies are needed on the dose and exposure time.
Collagen ; Daunorubicin* ; Fibroblast Growth Factors ; Fibroblasts ; Mitomycin* ; Rabbits ; Strabismus

OBJECTIVE: To explore the oxidative damage of OP9 cells induced by daunorubicin (DNR) treatment. METHODS: The TMRM probe was used to detect mitochondrial membrane potential by flow cytometry; the reactive oxygen species (ROS) was determined by flow cytometry DCFDA probe; the real-time PCR was used to detect the molecular expression of antioxidant enzyme，glutathione peroxidase (GPX) in OP9 cells; the expression of γ-H2AX was determined by flow cytometry. RESULTS: Compared with normal OP9 cells, the positive rate of TMRM in DNR-treated OP9 cells decreased by 56.7% (P＜0.05); the positive rate of DCFDA in DNR-treated OP9 cells increased by 3.52 times (P＜0.01). Compared with normal OP9 cells, DNR-treated OP9 cells showed a decrease in the expression of GPX4 by 44.22% (P＜0.001); the expression of GPX7 decreased by 65.7% (P＜0.001); the expression of GPX8 decreased by 24.7% (P＜0.001); the positive rate of γ-H2AX in DNR-treated OP9 cells increased (P＜0.05). CONCLUSION After DNR treatment, mitochondrial membrane potential of OP9 cells decreases; the level of reactive oxygen species increases; the expression of glutathione peroxidase (GPX) molecules decreases significantly; genomic instability increases obviously; the oxidative damage of cells increased.
Apoptosis ; Daunorubicin ; Mesenchymal Stem Cells ; Oxidative Stress ; Reactive Oxygen Species

OBJECTIVETo study the expression of annexin II (AnnII) and the fibrinolytic activity in NB4 cells and their alterations in the presence of arsenic trioxide (ATO) and daunorubicin (DNR).

METHODSLeukemia cell line NB4 was treated with ATO or DNR for 24 ∼ 72 h. Cell surface expression of AnnII and its mRNA were analysed by flow cytometry and real time PCR, respectively, the fibrinolytic activity by chromogenic assay.

RESULTSCompared with other acute leukemia cell lines, the expression of AnnII on untreated NB4 cells was relatively higher. The AnnII positive cell rates on NB4, HL-60, K562, and A3 cells were (94.5 ± 1.6)%, (40.1 ± 2.1)%, (36.3 ± 1.5)% and (11.8 ± 2.5)%, respectively. The fibrinolytic activity of NB4 cells was the greatest with a A value of 0.68 ± 0.02. The fibrinolytic activity of NB4 cells was obviously decreased by ATO, DNR or monoclonal antibody against AnnII, being decreased by 60.4%, 35.8% and 26.0% of the pretreatment level, respectively. The expressions of AnnII and its mRNA in NB4 cells were decreased dramatically after ATO and DNR treated for 48 h. Annexin II positive cells rate were (55.46 ± 4.72)% and (27.00 ± 6.18)%, respectively.

CONCLUSIONNB4 cells have strong ability to enhance the catalytic efficiency of the t-PA-dependent plasminogen activation and AnnII on the cell membrane contributes to this activity. Its high fibrinolytic activity can be corrected by ATO and DNR through down-regulating AnnII.

Annexin A2 ; Apoptosis ; Daunorubicin ; HL-60 Cells ; Humans ; Leukemia ; metabolism

Clostridium difficile (C. difficile) is one of the important pathogens which cause antibiotic-associated diarrhea (AAD) -diarrhea following antibiotic therapy. There are some reports of nosocomial outbreak of AAD caused by C. difficile.We analyzed risk factors and epidemiology of C. difficile-associated diarrhea (CAD) in Kumiai Hospital. From March 2003 to February 2004, 53 in patients developed AAD, of whom 35 patients (66%) were diagnosed as having CAD. Advanced age, bed-rest, tube-feeding, and prolonged administration of antibiotics were regarded as risk factors.In initial two months, seven cases developed CAD in one ward and five in another ward. After hand-washing and use of gloves were enforced in treating CAD patients, the incidence of CAD decreased. Epidemiological analysis was performed using PCR ribotyping of C. difficile strains recovered from 20 among 35 CAD cases in the different wards. Nineteen of 20 strains were identical, typed as the ribotype. These results may suggest nosocomial diarrhea but we cannot conclude that is a hospital infection as yet.Although all C. difficile strains recovered in this study were toxin A-positive, the result of the test using a toxin A detecting kit was negative in three cases. It is necessary toculture C. difficile in addition to detecting toxin A to diagnose CAD.
cytarabine/daunorubicin ; Carbon ion ; Diarrhea ; Clostridium difficile ; Toxins

Usually, tumor stem cells have been assessed functionally in animals with various in vivo transplantation assays or with in vitro colony forming assays. Such studies indicate the tumor stem cell assays can be used to study the properties of tumor stem cells and to delineate the difference in individual sensitivities to chemotherapeutic agents. Over the past year (1987,5-1988,4) we attempted to culture the epithelial tumor cells in laboratory to test the chemosensitivity to Methotrexate, cytarabine, and daunorubicin in different concentrations. The in vitro chemosensitivity of these cells to anticancer drugs was disappointed in much. Only 14% of the cultured cells were inhibited the growth more than 50% in over-all.
Animals ; Carcinoma, Transitional Cell ; Cells, Cultured ; Cytarabine ; Daunorubicin ; Methotrexate ; Neoplastic Stem Cells

Proliferative vitreoretinopathy (PVR) is a main cause of failure in retinal reattachment surgery. There have been many studies about the inhibition of proliferative vitreoretinophthy with several drugs. Authors investigated the inhibitory effect of proliferative vitreoretinopathy and retinal toxicity with various concentration of daunorubicin after intravitreal injection into the eyes of the pigmented rabbit. 7 pigment rabbit (11eyes) were used as subjects. After lensectomy and vitrectomy, control group was injected dermal fibroblast and F-BSS, and treatment group was injected dermal fibroblast and 5, 10, 15, 30 nmol Daunorubicin. At two weeks after intravitreal injection, both group were enucleated and examined with gross finding, light--microscopy, and electronmicroscopy. In all control group, proliferative vitreoretinopathy was found, but only preretinal membrane formation was found in 5, 10 nmol Daunorubicin injected group. In 15 nmol Daunorubicin injected group, the retina structure was preserved normally. In 30 nmol Daunorubicin injected group, the retinal outer segment was degenerated in microscopic finding. These results show that Daunorubicin has a potent effect on proliferative vitreoretinopathy, especially in 15 nmol, but retinal toxicity is suspected in marethan 30 nmol.
Daunorubicin* ; Fibroblasts ; Intravitreal Injections ; Membranes ; Retina ; Retinal Photoreceptor Cell Outer Segment ; Retinaldehyde ; Vitrectomy ; Vitreoretinopathy, Proliferative*

AIMTo study the electrochemical behavior of daunorubicin at Co/GC ion implantation modified electrode.

METHODSWith Co/GC ion implantation modified electrode as working electrode, daunorubicin was determined by voltammetry in 0.05 mol x L(-1) Na2HPO4-KH2PO4 (pH 6.82) solution.

RESULTSA sensitive reductive peak of daunorubicin was obtained by linear sweep voltammetry. The peak potential was -0.60 V (vs SCE). The peak current was proportional to the concentration of daunorubicin over the range of 2.84 x 10(-8) - 1.42 x 10(-6) mol x L(-1) and 1.42 x 10(-6) - 1.28 x 10(-5) mol x L(-1) with the detection limit of 1.42 x 10(-8) mol x L(-1). The reduction wave was applied to the determination of daunorubicin. The electrochemical behavior and reaction mechanism were studied by linear sweep and cyclic voltammetry.

CONCLUSIONThe reduction process was quasi-reversible with adsorption characteristics.

Antibiotics, Antineoplastic ; analysis ; chemistry ; Carbon ; Cobalt ; Daunorubicin ; analysis ; chemistry ; Electrochemistry ; Electrodes ; Hydrogen-Ion Concentration

The aim of this study was to observe the inhibitory effect of daunorubicin on KG1a cells and the expression of Eps8 which is a novel tumor-associated antigen with its full name epidermal growth factor receptor pathway substrate 8 (Eps8), and to explore the effect of daunorubicin on Eps8 expression in KG1a cells at mRNA and protein levels. The KG1a cells were treated with different concentration of daunorubicin for 24, 48, 72 h, then trypan blue staining was used to detect the inhibitory rate of KGla cells, RQ-PCR and Western blot were used to detect Eps8 mRNA and Eps8 protein expression. The results showed that daunorubicin inhibited the proliferation of KG1a cells in a dose and time dependent manner (r = 0.983, P < 0.01). Daunorubicin could reduce the mRNA and protein levels of Eps8 expression in dose and time dependent manners in KG1a cells (r = 0.979, P < 0.05). It is concluded that with the increasing of concentration and time of daunorubicin acting on KG1a cells, the cell proliferative inhibitory effect increased and the expression of Eps8 decreased, suggesting that the inhibitory effect of daunorubicin on KG1a cell proliferation is realized through downregulation of Eps8 expression.
Adaptor Proteins, Signal Transducing ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Daunorubicin ; pharmacology ; Humans