Assessment of mitochondrial metabolic oxidative state in living cardiomyocytes with spectrally-resolved fluorescence lifetime spectroscopy of NAD(P)H / 生物医学工程学杂志

The primary function of cardiac mitochondria is the production of ATP to support heart contraction. Examination of the mitochondrial redox state is therefore crucially important to sensitively detect early signs of mitochondrial function in pathophysiological conditions, such as ischemia, diabetes and heart failure. We study fingerprinting of mitochondrial metabolic oxidative state in living cardiomyocytes with spectrally-resolved fluorescence lifetime spectroscopy of NAD(P)H, the principal electron donor in mitochondrial respiration responsible for vital ATP supply. Here NAD(P)H is studied as a marker for non-invasive fluorescent probing of the mitochondrial function. NAD(P) H fluorescence is recorded in cardiac cells following excitation with 375nm UV-light and detection by spectrally-resolved time-correlated single photon counting (TCSPC), based on the simultaneous measurement of the fluorescence spectra and fluorescence lifetimes. Modulation of NADH production and/or mitochondrial respiration is tested to study dynamic characteristics of NAD(P) H fluorescence decay. Our results show that at least a 3-exponential decay model, with 0.4-0.7ns, 1.2-1.9ns and 8.0-13. Ons lifetime pools is necessary to describe cardiomyocyte autofluorescence (AF) within 420-560nm spectral range. Increased mitochondrial NADH production by ketone bodies enhanced the fluorescence intensity, without significant change in fluorescent lifetimes. Rotenone, the inhibitor of Complex I of the mitochondrial respiratory chain, increased AF intensity and shortened the average fluorescence lifetime. Dinitrophenol (DNP), an uncoupling agent of the mitochondrial oxidative phosphorylation, lowered AF intensity, broadened the spectral shoulder at 520 nm and increased the average fluorescence lifetime. These effects are comparable to the study of NADH fluorescence decay in vitro. In the present contribution we demonstrated that spectrally-resolved fluorescence lifetime technique provides promising new tool for analysis of mitochondrial NAD(P) H fluorescence with good reproducibility in living cardiomyocytes. This approach will enhance our knowledge about cardiomyocyte oxidative metabolism and/or its dysfunction at a cellular level. In the future, this approach can prove helpful in the clinical diagnosis and treatment of mitochondrial disorder.

Prevention and Countermeasures of Occupational Bloodborne Exposure Risks in Health Care Workers / 中华医院感染学杂志

OBJECTIVE To discuss the prevention and countermeasures of occupational bloodborne exposure risks in health care workers.METHODS The data of the exposure materials,and the management measure were collected.RESULTS Totally 397 people were exposed to hematogenous exposure injury,of which 96 doctors people,and 301 nurses,but no one got infection disease.CONCLUSIONS Good management can prevent the injury caused by occupational exposure.

Hospital Infection among Inpatients:Situation Analysis 2005-2007 / 中华医院感染学杂志

OBJECTIVE To sum up the cases of hospital infection,in order to further improve the experience of the work of hospital infection.METHODS The investigation of hospital infection situation among inpatients 2005-2007 was reviewed.RESULTS The hospital infection rates in 2005-2007 were 1.81%,1.65% and 1.52%,respectively,mainly in the lower respiratory tract infection and surgical incision.CONCLUSIONS Hospital infection is closely related with the age,the underlying diseases,the antibiotic misuse and the environment.