ABSTRACT
Ultrasonic bubble detection has been widely used in predicting the risk of decompression sickness and evaluating the efficiency and safety of decompression procedures. Currently, the widely used SPENCER scale is conducted by using Doppler ultrasound to monitor the bubble signal in the precordial region of subjects. KM grading system is a computerized system based on Doppler ultrasound. The grading score can be converted into SPENCER bubble grading scale score and the bubble grading is precise and suitable for the motion status. On the basis of the above two methods, the KISMAN integrated severity score, extended SPENCER bubble grading and simplified Doppler bubble grading system were established. They not only coordinated analysis of Doppler ultrasound bubble detection results with other risk factors of decompression disease, but also convenient to use computer for processing detection results. With the in-depth application of Fourier technique and empirical mode decomposition in Doppler audio bubble signal detection, methods such as three-parameter fuzzy analysis and energy operator method are playing an important role in automatic bubble analysis. Optimization of detection technology and improvement of sensitivity and accuracy of automatic analysis are important development directions in the field of decompression bubble Doppler grating technology.
ABSTRACT
<p><b>OBJECTIVE</b>To explore the oxidative modification effect and its mechanism of low density lipoprotein (LDL) in hyperlipidemia (HL) rats after treating with tetrahydrobiopterin (BH4).</p><p><b>METHODS</b>Fifty four 8-week-old male Wistar rats were used, these 54 rats were randomly divided into control group, high fat diet group (HL group), high fat diet and injected BH4 group (HL + BH4 group), and 18 in each group. The BH4 levels of blood fats and blood serum and its metabolites, the aortic reactive oxygen species, the end product malondialdehyde (MDA) and the LDL oxidation level were all determined by killing 6 experimental rats in each group at the first 8, 16, and 24 weeks of age respectively.</p><p><b>RESULTS</b>Treating with BH4 after 8 and 16 weeks, there was no significant difference in serum lipids among three groups (P > 0. 05); but ROS and MDA decreased significantly (P < 0.01); compared with control and HL groups, the BH4 level of HL + BH4 group increased a lot (P < 0.01); compared with control group, the BH4 content reduced obviously in aortic homogenate of HL group (P < 0.01), but the total petrin levels (TB = BH4 + BH2 + B) had no significant difference (P > 0.05); the serum TBARS formation increased gradually with the increase of week-ages, but compared with HL group, the serum TBARS formation of HL + BH4 group reduced significantly (P < 0. 01).</p><p><b>CONCLUSION</b>Treating with BH4 can reduced the LDL oxidation, the mechanism may be related to the correct of NOS uncoupling, the reduce of ROS generation and the decrease of LDL lipid peroxidation.</p>
Subject(s)
Animals , Male , Rats , Biopterins , Therapeutic Uses , Hyperlipidemias , Blood , Drug Therapy , Lipid Peroxidation , Lipids , Blood , Lipoproteins, LDL , Metabolism , Malondialdehyde , Metabolism , Rats, Wistar , Reactive Oxygen Species , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To explore the effect of the level of lipid peroxidation and biomechanical properties after chronic treating with tetrahydrobiopterin (BH4) in thoracic aorta of hyperlipemia (HL) rats.</p><p><b>METHODS</b>HL rats were given BH4 chronically. The opening angle in the zero-stress state and the relationship between pressure and diameter (P-D) of mesenteric artery were measured by computer image 8, 16, and 24 week-old respectively.</p><p><b>RESULTS</b>Treating with BH4 chronically from 8 week-old in HL rats, there was a significant increase in the zero-stress state of opening angle of thoracic aorta. The P-D curve of mesenteric artery moved upward.</p><p><b>CONCLUSION</b>Treating with BH4 prevented the structure and function of artery from abnormal changing, and attenuated lipid peroxidation in HL rats.</p>
Subject(s)
Animals , Male , Rats , Aorta, Thoracic , Metabolism , Biomechanical Phenomena , Biopterins , Therapeutic Uses , Hyperlipidemias , Drug Therapy , Lipid Peroxidation , Rats, WistarABSTRACT
<p><b>AIM</b>To explore the effect of remodeling and biomechanical properties after chronic treating with tetrahydrobiopterin (BH4) in spontaneously hypertensive rats.</p><p><b>METHODS</b>The spontaneously hypertensive rat(SHR) were given with BH4 chronically. The opening angle in the zero-stress state , wall-to-lumen area ratios (W/L) of thoracic aorta and the relationship between pressure and diameter (P-D) of mesenteric artery were measured by computer image analysis in 4, 16, and 26 week-old respectively.</p><p><b>RESULTS</b>Treating with BH4 chronically from 4 weeks-old in SHR, there was a significant decrease in morphometric parameters of the thoracic aorta and an increase in the zero-stress state of opening angle of elastic artery. The P-D curve of mesenteric artery moved upward.</p><p><b>CONCLUSION</b>Treating with BH4 prevented the structure and function of artery from abnormal changing, including to attenuate the resistant vascular hypertrophy and recover the vascular elasticity and expansibility.</p>