We investigated the significance of endogenous reactive oxygen species (ROS) produced by fungi treated with miconazole. ROS production in Candida albicans was measured by a real-time fluorogenic assay. The level of ROS production was increased by miconazole at the MIC (0.125 g/ml) and was enhanced further in a dose-dependent manner, with a fourfold increase detected when miconazole was used at 12.5 g/ml. This increase in the level of ROS production was completely inhibited by pyrrolidinedithiocarbamate (PDTC), an antioxidant, at 10 M. In a colony formation assay, the decrease in cell viability associated with miconazole treatment was significantly prevented by addition of PDTC. Moreover, the level of ROS production by 10 clinical isolates of Candida species was inversely correlated with the miconazole MIC (r ‫؍‬ ؊0.8818; P < 0.01). These results indicate that ROS production is important to the antifungal activity of miconazole.Candidiasis is a life-threatening disease in patients with immune suppression. Azoles are used widely for the treatment of candidiasis, but some clinical isolates show resistance (11,28). Further investigation of the mechanisms underlying the antifungal effects of azoles may aid in the development of new treatment strategies.Azoles exert a cytostatic or cytotoxic effect via inhibition of synthesis reactions in the metabolic pathways of essential fungal cell membrane components including ergosterol (29,30). Their primary target is the cytochrome P450-catalyzed 14␣-demethylation of ergosterol precursors. Mutations or overexpression of 14␣-demethylase, encoded by the ERG11 gene, as well as changes in the ergosterol synthesis pathway reportedly participates in the induction of resistance (14,19,20,25).Since it was found that miconazole, ketoconazole, and deacetylated ketoconazole were inserted in a lipid layer (6) and miconazole induced the release of K ϩ and intracellular ATP from Candida species (3, 4, 7), these agents may cause direct membrane damage.Recent studies clarified that a decrease in drug concentration brought about by energy-dependent efflux pumps is usually involved in multidrug resistance including azole resistance (1,2,16,26). This pumping system closely resembles a system in cancer cells based on the P-glycoprotein encoded by the MDR-1 gene. Thus, common biologic mechanisms shared with other eukaryotic cells are involved in the antifungal effects of azoles.In eukaryotic cells, mitochondria are common organelles that represent an important source of reactive oxygen species (ROS). Many cellular stresses such as irradiation and cytotoxic drugs cause growth inhibition and the death of mammalian cells via endogenous ROS production (5, 15, 27). ROS produced by granulocytes or monocytes are known to exert activity against fungi (9, 31). Furthermore, recent studies demonstrated that Candida albicans possesses an ROS scavenger, superoxide dismutase; this suggests that fungi may require a cytoprotective mechanism against not only exogenous ROS but also endogenous, fungus-derived ROS (1...

Detachment of cell-cell adhesion is indispensable for the first step of invasion and metastasis of cancer. This mechanism is frequently associated with the impairment of either E-cadherin expression or function. However, mechanisms of such abnormalities have not been fully elucidated. In this study, we demonstrated that the function of E-cadherin was completely abolished in the human gastric cancer cell line HSC-39, despite the high expression of E-cadherin, because of mutations in one of the E-cadherin-associated cytoplasmic proteins, ␤-catenin. Although immunofluorescence staining of HSC-39 cells by using an anti-E-cadherin antibody (HECD-1) revealed the strong and uniform expression of E-cadherin on the cell surface, cell compaction and cell aggregation were not observed in this cell. Western blotting (immunoblotting) using HECD-1 exhibited a 120-kDa band which is equivalent to normal E-cadherin. Northern (RNA) blotting demonstrated a 4.7-kb band, the same as mature E-cadherin mRNA. Immunoprecipitation of metabolically labeled proteins with HECD-1 revealed three bands corresponding to E-cadherin, ␣-catenin, and ␥-catenin and a 79-kDa band which was apparently smaller than that of normal ␤-catenin, indicating truncated ␤-catenin. The 79-kDa band was immunologically identified as ␤-catenin by using immunoblotting with anti-␤-catenin antibodies. Examination of ␤-catenin mRNA by the reverse transcriptase-PCR method revealed a transcript which was shorter than that of normal ␤-catenin. The sequencing of PCR product for ␤-catenin confirmed deletion in 321 bases from nucleotides ؉82 to ؉402. Southern blotting of ␤-catenin DNA disclosed mutation at the genomic level. Expression vectors of ␤-catenin were introduced into HSC-39 cells by transfection. In the obtained transfectants, E-cadherin-dependent cell-cell adhesiveness was recovered, as revealed by cell compaction, cell aggregation, and immunofluorescence staining. From these results, it was concluded that in HSC-39 cells, impaired cell-cell adhesion is due to mutations in ␤-catenin which results in the dysfunction of E-cadherin.

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We examined whether survivin acts as a constitutive and inducible radioresistance factor in pancreatic cancer cells. Using a quantitative TaqMan reverse transcription-polymerase chain reaction for survivin mRNA in five pancreatic cancer cell lines, we found an inverse relationship between survivin mRNA expression and radiosensitivity. PANC-1 cells, which had the highest survivin mRNA levels, were most resistant to X-irradiation; MIAPaCa-2 cells, which showed the least survivin mRNA expression, were the most sensitive to X-irradiation. Our results suggested that survivin could act as a constitutive radioresistance factor in pancreatic cancer cells. To determine whether radioresistance is enhanced by induction of survivin expression by irradiation, PANC-1 and MIAPaCa-2 cells were subjected to sublethal doses of X-irradiation followed by a lethal dose. Survivin mRNA expression was increased significantly in both PANC-1 and MIAPaCa-2 cell lines by pretreatment with a sublethal dose of X-irradiation, as was cell survival after exposure to the lethal dose. In this system, enzymatic caspase-3 activity was significantly suppressed in cells with acquired resistance. These results suggest that survivin also acts as an inducible radioresistance factor in pancreatic cancer cells. Survivin, then, appears to enhance radioresistance in pancreatic cancer cells; inhibition of survivin mRNA expression may improve the effectiveness of radiotherapy.

SR imaging can detect impairment of LA reservoir and conduit functions as well as LV systolic and diastolic dysfunctions in patients with DM, even in the absence of LV hypertrophy and LA dilatation. Coexisting HT augments the impairment of LV diastolic and LA conduit functions in diabetic patients.

Background: The significance of serum concentrations of tumor necrosis factor-α (TNF-α) in the pathogenesis of inflammatory bowel disease (IBD) is uncertain. We measured TNF-α in serum from IBD patients by immuno-PCR to analyze the relationship between TNF-α and pathophysiologic state in IBD. Methods: Serum samples were collected from 54 healthy blood donors, 29 patients with ulcerative colitis (UC; 46 samples), and 7 patients with Crohn disease (CD; 8 samples). DNA label was generated by PCR amplification using biotinylated primer and was bound with streptavidin to biotinylated third antibody. TNF-α sandwiched by antibodies was detected by PCR amplification of the DNA label. Results: TNF-α could be measured in all samples. The median serum concentration in IBD patients overall was ∼390-fold higher than in healthy donors (median increase, 380-fold for UC, 640-fold for CD). The median serum TNF-α concentration was 1.7-fold higher in the active stage of UC than in the inactive stage (P &lt;0.05), and this difference could be detected in individual patients. Conclusions: Sensitive measurement of serum TNF-α could provide an important pathophysiologic marker for the presence and activity of IBD.

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