Percutaneous transluminal radiofrequency closure of the coronary artery in animal studies.

The aim of this study was to investigate the safety and effectiveness of a novel method for the selective transcoronary closure of small coronary arteries by the intraluminal application of radiofrequency (RF) energy. Twenty-six small (diameter of 1-2 mm) coronary artery branches were selected in 13 dogs. An RF electrode wire (CRW-Zcy) was placed into the target vessel and a coronary balloon was used to transiently block the blood flow and limit damage to the proximal vessel. A therapeutic dosage of 20-30 W of RT energy every 10-30 sec (selected according the diameter of the target artery) was discharged via the CRW-Zcy inside a microcatheter two or three times in order to achieve arterial closure. A high dosage of 60 W every 120 sec of RF energy was used to conduct the safety study. All 26 branches were successfully closed resulting in the complete blockage of the antegrade and retrograde flows. The area of injury was limited to the target artery and the supplied myocardium. High-dose RF did not cause injury to the adjacent vessels and myocardium. The animals tolerated the procedure well without any untoward systemic effects. A follow-up angiography at two weeks revealed no evidence of recanalization or retrograde filling of the target artery. Percutaneous transluminal radiofrequency closure is a safe and effective interventional approach for closing the small coronary arteries, and is potentially valuable for further investigation.

[A discussion about the tactics of mechanical ventilation for acute respiratory distress occurring in the first case of influenza A (H5N1) in Guizhou Province].

OBJECTIVE: To discuss the tactics of mechanical ventilation in a human severe case of influenza A (H5N1) complicated with acute respiratory distress syndrome (ARDS). METHODS: The data of the patient infected by the influenza A (H5N1) admitted to People's Hospital of Guizhou Province on January 15, 2009, were analyzed and summarized. RESULTS: The patient, a 29-year-old man, had been healthy in the past, but had exposed to the environment of bird flu before illness. The initial symptom was unremitting high fever, and then the clinical situation deteriorated progressively with occurrence of dyspnea. Pulmonary infiltrates were evident in the left lower lobe on January 19, and rapidly progressed to involve bilateral lungs presenting ARDS-like changes. Mechanical ventilation became the most important treatment among others. The ventilation mode was synchronized intermittent mandatory ventilation (SIMV)+ pressure support (PS) + positive end expiratory pressure (PEEP), following lung protective ventilatory strategies, with low tidal volume. The patient's condition improved day by day without developing multiple organ dysfunction. The patient fully recovered and was discharged on February 6. CONCLUSION: Early detection, early diagnosis, and finely effective intervention are to improve oxygenation by mechanical ventilation with low tidal volume and adequate PEEP are critical to reducing the mortality.

Atorvastatin reduces tissue factor expression in adipose tissue of atherosclerotic rabbits.

BACKGROUND: We have recently demonstrated that tissue factor (TF) expression increases in adipose tissues/adipocytes of cholesterol-fed rabbit, which is associated with a hypercoagulable state that contributes to thrombosis. In this study, we evaluated the ability of atorvastatin to modulate TF expression in cholesterol-fed rabbit and the regulatory mechanism. METHODS: Male rabbits were randomly fed with normal diet and high-cholesterol diet for 8 weeks, following 4 weeks, those fed high-cholesterol diet were randomly assigned to atorvastatin or starch. At the end of 12 weeks, subcutaneous adipose was collected, and culture adipocyte. TF mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). TF concentrations were determined with ELISA. The in vitro effect of atorvastatin and mevalonate (MVA) on TF production in adipocytes was observed. RESULTS: Atorvastatin reduced serum TC and LDL-C levels (P<0.05), and decreased plasma TF concentration and expression in adipose tissues/adipocytes from cholesterol-fed rabbits. In vitro, atorvastatin dose-dependently suppressed TF expression and protein secretion in adipocytes. MVA reversed the inhibitory effect of atorvastatin on TF expression in concentration-dependent manner. CONCLUSIONS: Results provide further support for the antithrombotic effect of atorvastatin. It also indicated that mevalonate pathway may play an important role in TF expression in adipocyte.

Atorvastatin reduces plasminogen activator inhibitor-1 expression in adipose tissue of atherosclerotic rabbits.

BACKGROUND: Plasminogen activator inhibitor-1 (PAI-1) expression are increased in adipose tissues/adipocytes of obese mice, which is associated with a hypofibrinolytic state that contributes to thrombosis. We recently demonstrated that PAI-1 expression increases in adipose tissues/adipocytes of cholesterol-fed rabbits. In this study, we evaluated the ability of atorvastatin to modulate PAI-1 expression in cholesterol-fed rabbits and the regulatory mechanism. METHODS: Male rabbits were randomly fed with normal diet and high-cholesterol diet for 8 weeks, following 4 weeks, those fed high-cholesterol diet were randomly assigned to 2.5 mg/kg/day atorvastatin or starch. At the end of 12 weeks, subcutaneous adipose was collected, and culture adipocyte. PAI-1 mRNA was detected by RT-PCR. PAI-1 concentrations were determined with ELISA. The effect of atorvastatin and mevalonate (MVA) on PAI-1 production in adipocytes in vitro was observed. RESULTS: Atorvastatin significantly reduced serum TC and LDL-C concentrations (p<0.05), and decreased plasma PAI-1 concentration and PAI-1 expression in adipose tissues/adipocytes from cholesterol-fed rabbits. In vitro, atorvastatin dose-dependently suppressed PAI-1 expression and protein secretion in adipocytes. MVA reversed the inhibitory effect of atorvastatin on PAI-1 expression in concentration-dependent manner. CONCLUSIONS: Atorvastatin reduces plasma PAI-1 concentration and PAI-1 expression in adipose tissue and adipocyte of atherosclerotic rabbit, and inhibits PAI-1 expression and protein secretion in adipocytes in vitro, suggesting that it may have an antithrombtic effect. We also suggest that the mevalonate pathway may play an important role in PAI-1 expression in adipocyte.

[Development of a portable ECG monitor with diagnostic & therapeutic functions and its clinical applications].

A portable ECG monitor is introduced in the paper, which has a temporary intravenous and transesophageal fixable rate pacing function. During the PSVT attack, the tachyarrythmia can be stopped by the transesophageal cardiac pacing while the ECG signals are monitored. The instrument has some advantages such as small size, low price and good practicality. It is worth while introducing and popularizing it to all hospitals.

[Development and research of temporary demand pacemaker with electrocardiosignal display].

A temporary demand pacemaker with electrocardiosignal display is introduced in this paper. Double way low-noise electrocardiosignal preamplifier, amplitude limiter, high and low pass filter, 50 Hz notch filter, TTL level generator and stimulating pulse formation circuit are components of the hardware electrocircuit. The demand pacing and the electrocardiosignal display are separately controlled by the software in which the double microcontrollers communications technique is used. In this study, liquid crystal display is firstly used in body surface electrocardiosignal display or intracardial electrophysiologic signal display when the temporary demand pacemaker is installed and put into use. The machine has proven clinically useful and can be of wide appliation.