• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.250-256
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• 2004

Background : Bacterial infections in diabetic patients are an important cause of increased morbidity and mortality. It has been reported that bacterial infections in diabetics showed more impaired PMN functions such as reduced PMN respiratory burst and decreased microbicidal activity in inflammed tissues. Also, apoptosis(programmed cell death) is postulated to be a key mechanism for neutrophil elimination. It is very important that PMN apoptosis keeps the balance from an area of inflammation. Actuallly, as little was known about PMN apoptosis and respiratory burst in diabetes, we investigated PMN apoptosis and hydrogen peroxide production after endotoxin exposure. Methods : Peripheral venous blood samples were collected by routine venipuncture from healthy volunteers and diabetics to harvest neutrophils. We respectively measured the PMN apoptosis, the production of hydrogen peroxide, and the cell viability. Results : Normal neutrophils showed a tendency to decreased apoptosis after endotoxin treatment. In patients with diabetes, PMN apoptosis was significantly decreased compared with healthy controls. In addition, the LPS-induced neutrophils in diabetics demonstrated more decreased apoptosis. However, the production of hydrogen peroxide was not different between groups. Conclusion : These observations suggest that the decreased PMN apoptosis in diabetics with endotoxin exposure may also affect the increased susceptibility and severity of infections.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.766-770
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• 2013

Several upstream activators required for proper activation of brlA are involved in the development, vegetative growth, toxin production, and pathogenesis of Aspergillus fumigatus. In this study, we characterized the roles of two upstream developmental regulators, A. fumigatus flbB (AfuflbB) and flbE (AfuflbE), in toxin production and virulence. The deletion of AfuflbB and AfuflbE resulted in reduction of the expression of AfulaeA. Moreover, only about 8% to 10% of fumagillin was produced in the two mutants compared with that of wild type, and ${\Delta}AfuflbB$ strain produced 85% of gliotoxin compared with wild type, whereas none was produced by ${\Delta}AfuflbB$. Flow-cytometric analysis revealed decreased necrotic and apoptotic polymorphonuclear leukocytes cell death after exposure to supernatants from ${\Delta}AfuflbB$ and ${\Delta}AfuflbB$ strains compared with the wild type. These results indicate that FlbB and FlbE are necessary for the proper laeA expression, toxin production, and virulence of A. fumigatus.