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Biomedical subjects

Li Rao

Publications and source records attributed to Li Rao.

17 recordsLinked to original sources
PubMed2006

Effects of autologous stem cell transplantation on ventricular electrophysiology in doxorubicin-induced heart failure.

To investigate whether stem cell transplantation affects ventricular electrophysiology in vivo, either autologous bone marrow mesenchymal stem cells or skeletal myoblast cells were transplanted via a catheter into a doxorubicin-treated failing heart. Four weeks after transplantation, electrophysiological investigation showed that transplantation of either cell type prolonged the local activation time and increased the activation time dispersion. In the stem cell transplantation groups, a positive correlation was demonstrated between activation time dispersion and the number of stem cell-derived cells in the pacing site. It is concluded that transplantation of either mesenchymal stem cells or skeletal myoblast cells might exacerbate abnormalities of local ventricular conduction in the doxorubicin-treated failing heart.

Animals↗
PubMed2006

[Correlation between desmin gene, platelet-activating factor acetylhydrolase gene and dilated cardiomyopathy].

OBJECTIVE: To test the Missense mutation of Desmin gene (Ile451Met), the frequency of missense mutation (G994-->T) of Platelet-Activating Factor Acetylhydrolase (PAF-AH) gene, and the correlation between these mutations and dilated cardiomyopathy (DCM) in the Chinese population with DCM. METHODS: A case control study was conducted with 89 DCM patients and 110 healthy people (control group) participating in the study. The exon 8 of Desmin gene and exon 9 of PAF-AH gene were identified by polymerase chain reaction, restriction enzyme digestion, polyacrylamide gel electrophoresis and DNA sequencing for described mutation site of Desmin (Ile451Met) and PAF-AH (Val279Phe). RESULTS: No mutation (Ile451Met) in Desmin gene was found in either the DCM patients or the healthy people. There was no significant difference in the frequency of PAF-AH gene mutation (Val279Phe) between the patient and control groups (P>0.05). CONCLUSION: Neither the mutation of Ile451Met in gene encoding for Desmin exon 8 nor the mutation frequency of PAF-AH gene (G994-->T) has correlation with the DCM.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2006

[Review of nonlinear filters for medical ultrasonic images].

Ultrasound medical imaging has been widely applied in clinic diagnoses because of its real-time, non-invasiveness and convenience. However, it suffers from severe speckle noises. Until now, a lot of filtering algorithms have been proposed, but none of them is satisfactory. In this paper, four nonlinear filter methods, based on median filter, wavelet decomposition and anisotropic diffusion, are systematically reviewed. Finally, the prospect of the nonlinear filtering method is discussed.

Algorithms↗
PubMed2006

[Changes of heart function after different cell type stem cell transplantation in chronic heart failure].

To investigate the feasibility of introcoronary cell infusion into nonischemic heart failure (HF) heart and whether different types of stem cell transplantation would affect heart function to a similar degree. Japanese white ears rabbits were used as HF models by intravenous injection adriamycin. Autologous bone marrow mononuclear cells(BMCs), bone marrow stromal cells (MSCs), skeletal myoblasts (SMs) or culture medium were infused into coronary arteries respectively by occluding the root of ascending aorta. The mortality during and 4 weeks after the procedure the mortality was 7.1% and 16.7% respectively. After 4 weeks, the ejection fraction (EF) in BMCs group had significant improvement (P < 0.05, n=8). No significant difference was seen in MSCs (n =8), SMs (n=6) and sham groups (n=8) compared with pretransplantation (P > 0.05). In sham group,the left ventricular endostolic diameter (LVED) had significant enlargement (P < 0.05), No significant difference was seen in MBCs, MSCs and SMs groups compared with pretransplantation (P > 0.05). Immunofluorescence revealed de novo expression of cardiac troponin I in BMCs and MSCs groups, cardiac troponin I was not detected in SMs group. In conclusions, intracoronary cell transplantation could provide effective cell delivery into dilated cardiomyopathy hearts and could be a useful strategy for treating CHF, BMCs cell transplantation may be the first choice in all the above cell types.

Animals↗
PubMed2005

[Feasibility of stem cells transplantation through aorta in adriamycin-induced heart failure].

Stem cells transplantation is a promising strategy for treating myocardial infarction and/or chronic heart failure; however, with respect to nonischemic heart failure, there are some limitations inherent in the current methods of transplantation. In this study, we investigated the feasibility of a novel method, i. e. transplantation through the root of aorta when the ascending aorta occluded above the sinus aortae. Japanese white ears rabbits were used as chronic heart failure models by intravenous injection of adriamycin. Autologous bone marrow mononuclear cells (MNC) were infused into the root of aorta when the ascending aorta was occluded by a couple of balloons above the sinus aortae. After 4 weeks, ejection fraction was significantly improved in MNC group. In conclusion, we have developed a unique method for efficient and safe cell transplantation based on infusion in aorta. This method, potentially suitable for nonischemic heart failure and could be used to achieve even and global supply of cells in heart.

Animals↗
PubMed2005

[A medical ultrasonic image filtering method based on anisotropic diffusion].

OBJECTIVE: To remove the speckle noise in ultrasonic images by using anisotropic diffusion method. METHOD: Based on anisotropic diffusion, a partial differential equation, of which the initial data was the input images, was transformed into differential forms and solved with iterations. The speckle scale function of the equation was modified to make better use in filtering medical ultrasonic images. RESULT: By comparing the results with other three filters, the anisotropic diffusion method could smooth the speckles very well and the edge of the image was also clear. CONCLUSION: Anisotropic diffusion can remove the speckle noise effectively and has great potential in filtering medical ultrasonic images.

Anisotropy↗
PubMed2005

Automatic segmentation of echocardiography based on a morphological reconstruction algorithm.

OBJECTIVE: To improve the precision of the traditional segmentation of echocardiogram, by suppressing the influence from inherent speckle noises in medical ultrasonic images. METHOD: An automatic segmentation method based on reconstructed morphology was proposed in this paper. First, the opening and closing operations by reconstruction were imposed to the ultrasonic image. Second, the top-hat operation was used to extract the bright and/or dark features and to find out the boundaries corresponding to these features, whereby implemented the automatic segmentation. RESULT: The segmented echocardiogram had less artificial boundaries resulted from speckle noise, and could accurately be extracted the artery and ventricle. CONCLUSION: The presented method can detect both dark and bright objects accurately, and the boundary has a fine continuity. In addition, the algorithm is also applicable to the extraction of sole bright/dark features, accordingly to reduce the complexity and time needed and to improve the accuracy.

Algorithms↗
PubMed2005

[Association between phospholamban gene mutation and dilated cardiomyopathy in the Chengdu area].

OBJECTIVE: To find out whether phospholamban (PLN) is the virulence gene of dilated cardiomyopathy (DCM) in the Chinese of Chengdu. METHODS: DNA was isolated from 89 hospitalized unrelated patients with DCM and 110 healthy Chinese Hans as controls. The PLN mutations was screened by polymerase chain reaction (PCR)-single strand conformation polymorphisms (SSCP) and nucleotide sequence analysis. RESULTS: In polyacrylamide gel lectrophoresis, no abnormal conformer was found in the two groups. In DNA sequence, no C --> T missense mutation at nucleotide 25 was identified in the DCM patients and the controls. Meanwhile, T --> G missense mutation at nucleotide 116 was not found in the affected individuals and in the controls. CONCLUSION: No PLN gene mutation was found in patients with DCM in Chengdu. This result indicated that PLN gene mutation may not be a common cause for DCM in the Chinese population in Chengdu.

Base Sequence↗
PubMed2005

[Recommendations for mitral regurgtitation with Doppler echocardiography].

Mitral regurgitation is one of the most serious heart diseases. With the development of up-to-date medical techniques, the ratio of successful operations in valvular repair and valvular replacement has been largely improved. Examinations before operation become extremely crucial. Accurate method is required in assessing the degree of mitral regurgitation to set down the corresponding treatment method. This paper reviews the evaluation methods of mitral valvular regurgitation provided in these years and presents comments on the application areas as well as the merits and disadvantages of those methods. Finally, the prospect of the method based on three-dimensional Doppler ultrasonographic imaging on mitral regurgitation is discussed.

Echocardiography, Doppler, Color↗
PubMed2004

[Further study on heterogeneic basis of complement C8 beta deficiency].

OBJECTIVE: In Caucasian population, the most common molecular basis for C8 beta deficiency s a single C to T transition in exon 9 of C8 beta gene resulting in a stop codon. In previous family studies, two individuals were identified with C8 beta complete deficiency and were found to be only heterozygous for this mutation. This study was conducted by the present authors in search of other possible causes for these two C8 beta deficient individuals. METHODS: Using direct DNA sequence analysis of all exon-specific PCR products of the C8 beta gene from these two C8 beta deficient patients and their descendants. RESULTS: Two other C to T transitions at base 298 and 388 in exon 3 were detected, which could also create a termination codon. The descendants from one of the deficient patients were also analysed for the mutations, and it could be demonstrated that the two C to T mutations in exons 9 and 3 are segregating independently. CONCLUSION: These two mutations, which create a termination codon, are sufficient to explain the complete C8 beta deficiency in both patients.

Codon, Nonsense↗
PubMed2004

[Study on association between aldosterone synthase gene polymorphism and the left ventricular structure and function of patients with dilated cardiomyopathy in China].

OBJECTIVE: To investigate the association between a -344 C/T polymorphism of aldosterone synthase gene (CYP11B2) and the left ventricular structure and function of patients with dilated cardiomyopathy (DCM) in China. METHODS: Eighty-nine patients with DCM were genotyped by PCR-RFLP, and were divided into TT, TC, CC and TT+CC four groups by their genotypes, respectively. Left ventricular structure and function were assessed with echocardiography. RESULTS: There was no significant difference between four groups in left ventricular diameters, mass and ejection fraction in patients with DCM. CONCLUSION: The data were not in favor of a significant association between the aldosterone synthase gene CYP11B2 and the left ventricular structure and function in patients with DCM.

Adult↗
PubMed2003

[A study on the construction of allelic ladders for 4 short tandem repeat loci (D7S817, D10S1432, D10S1213 and D18S865) and their genetic polymorphism in two Chinese populations].

OBJECTIVE: To produce standard allelic ladders for four STR loci(D7S817, D10S1432, D10S1213 and D18S865) by recombined plasmids and use them in the research of genetic polymorphism. METHODS: After being amplified by PCR, different STR allelic fragments were isolated from the polyacryramide gel. The STR allelic fragments were eluted into distilled water and reamplified by PCR to obtain purified allelic fragments. Next, the purified allelic fragments were subcloned individually into the PUC plasmid vectors, and the size and structure of the inserts were confirmed by the analysis of their DNA sequences. Then we transfected the PUC plasmid vectors into E. coli DH5 alpha cells, worked on selective culture, and finally, mixed the alleles of the four STR loci respectively. RESULTS: The standard allelic ladders for four new loci (D7S817, D10S1432, D10S1213 and D18S865) were obtained, with which the genetic polymorphisms of four new loci in Chinese Hans and Dongxiang ethnic groups were studied. CONCLUSION: The standard STR allelic ladders acquired by this method are of high value in forensic practice, and they are applicable to the analysis of genetic polymorphism.

Alleles↗
PubMed2003

[Associations between aldosterone synthase gene polymorphisms and left ventricular structure and function in Chinese normal Han People].

OBJECTIVE: The aim of the present study was to investigate the association between a polymorphism of the aldosterone synthase gene CYP11B2 and left ventricular structure and function in Chinese Han people. METHODS: One handred and ten persons aged 20 to 49 years were studies by echocardiography to assess left ventricular size, mass and function. The subjects were genotyped with the use of PCR-RFLP. RESULTS: Three genotypes for aldosterone synthase at position -334 in the transcriptional regulatory region were found: TT, TC and CC. The distribution of sex and arterial blood pressure was homogeneous in the aldosterone synthase genotype groups. No significant associations of echocardiographic LV dimensions, mass and function with a specific aldosterone synthase genotype were noted. CONCLUSION: The above data are not in favor of a significant association between the polymorphisms of aldosterone synthase gene CYP11B2 and the LV structure and function in Chinese normal Han people.

Adult↗
PubMed2002

[Hemodynamics monitoring of liver transplantation with color Doppler ultrasound].

By hemodynamic monitoring of liver transplantation with Color Doppler ultrasound, we observed the hemodynamic changes pre- and post-operatively and the patency of the anastomotic vessels, to detect or exclude the presence of complications, then assess the prognosis. We measured the hepatic blood flow after orthotopic liver transplantation in recent 6 cases, and observed the patency of anastomostic vessels and the hemodynamic improvement of the portal vein and hepatic arteries. The abnormal liquid and solid echoes were not found around the transplantated liver in all 6 cases. The echoes of hepatic parenchyma and tububes were normal. The direction and speed of blood flow were also normal. Five of anastomoses of portal vein in 6 cases were patent. The rest one was a little stenosed, and the speed of local blood flow was a little faster. There were 11 patent ones and 1 mildly stenosed in the 12 anastomoses of inferior venae cavae. The speed index(SI) and resistance index(RI) of hepatic arterial blood flow distal to the anastomoses were all normal. Liver transplantation is the redical therapying of portal hypertension, and the color Doppler ultrasound is the best non-invasived method for monitoring the hemodynamic changes of transplantated liver.

Adult↗