Biomedical subjects

Mei Wang

Publications and source records attributed to Mei Wang.

At least 19 recordsLinked to original sources

PubMed2026

Comparative analysis of histological and transcriptomic characteristics in caudal muscles of nile crocodiles (Crocodylus niloticus), siamese crocodiles (Crocodylus siamensis), and their hybrids.

Crocodylus niloticus and Crocodylus siamensis are high-value aquaculture species. C. niloticus is large-bodied but less abundant, while C. siamensis grows fast but is small-sized. Their hybrids combine parental advantages, yet relevant research is scarce. This study compared the histological and transcriptomic characteristics of the caudal muscle across the three taxa. HE staining indicated that C. niloticus had significantly larger myofiber diameters (p < 0.05); C. siamensis had the smallest, and the myofiber density of hybrids was much closer to that of C. siamensis. Masson's trichrome staining indicated that C. niloticus had the thickest collagen fibers (p < 0.05), C. siamensis the thinnest, and hybrids exhibited highly similar histological traits to C. siamensis. C. niloticus had higher LDH and SDH activities in caudal muscles, whereas the hybrid crocodile indicated the highest CK activity. Transcriptomic analysis identified numerous differentially expressed genes (DEGs), which were enriched in growth, muscle metabolism, and energy allocation pathways via GO/KEGG annotations. PPI analysis screened 24 hub genes related to energy metabolism. This study systematically reveals caudal muscle differences, providing insights into growth-related molecular mechanisms and theoretical support for crocodile artificial breeding.

Animals↗

PubMed2025

Biosynthesis and regulatory mechanism of tanshinones and phenolic acids in Salvia miltiorrhiza.

Salvia miltiorrhiza, a perennial plant of the genus Salvia in the family Lamiaceae, is one of the most important traditional Chinese medicinal herbs, renowned for its significant economic and medicinal value. Its application in China dates back to 200 BC, where it has been utilized clinically either as a monotherapy or in combination with other herbal medicines for treating cardiovascular and cerebrovascular diseases, as well as various other ailments. The bioactive constituents of S. miltiorrhiza primarily include lipophilic tanshinones and hydrophilic phenolic acids. Over the past decades, the biosynthetic pathways of tanshinones and phenolic acids have been elucidated. Coupled with the sequencing of its genome, substantial progress has been made in deciphering the biosynthesis and regulatory mechanisms of bioactive compounds in S. miltiorrhiza, including tanshinones, phenolic acids, flavonoids, and prenylated quinones. This review summarizes recent advances in the regulatory mechanisms underlying the biosynthesis of phenolic acids and tanshinones in S. miltiorrhiza, focusing on transcriptional regulation, post-translational modifications, and epigenetic regulation. These insights provide a foundation for enhancing the production of bioactive compounds through biotechnological approaches and advancing pharmacological applications.

Salvia miltiorrhiza↗

PubMed2007

Community-based screening for chronic kidney disease among populations older than 40 years in Beijing.

BACKGROUND: Chronic kidney disease (CKD) is a public health problem, while data from developing countries are limited. We sought to investigate the epidemiological features of kidney damage in metropolis-residing Chinese adults (>40 years old), and to determine the associated factors of CKD. METHODS: Two thousand three hundred and fifty-three residents in one district of Beijing were interviewed and tested for albuminuria, reduced renal function, haematuria and pyuria. The associations between demographic characteristics, health characteristics and indicators of kidney damage were examined. RESULTS: Albuminuria was detected in 6.2% of subjects; reduced renal function was found in 5.2% of subjects; haematuria was found in 0.8% and non-infective pyuria was found in 0.09%. Approximately, 11.3% (95% confidence interval: 10.0-12.8%) of subjects had at least one indicator of kidney damage. The awareness rate of CKD was only 7.2%. Systolic blood pressure and diabetes were independently associated with albuminuria. Age, diastolic blood pressure, hypercholesteraemia, hypertriglyceridaemia and hyperuricaemia were independently associated with reduced renal function. CONCLUSIONS: This is the first report on the prevalence of CKD in a community-based population within a developing country, determined using protocols recommended by kidney disease improving global outcomes (KDIGO). The prevalence of CKD in our population was close to the levels observed in developed countries, and the spectrum of CKD and associated factors were similar to developed countries. Results from this study suggest that strategies aimed at an intervention of hypertension and other metabolic disorders might prove effective in controlling the pandemic of CKD in China, as well as other developing countries.

Aged↗

PubMed2006

N-terminal pro-brain natriuretic peptide: an independent risk predictor of cardiovascular congestion, mortality, and adverse cardiovascular outcomes in chronic peritoneal dialysis patients.

This study was performed to determine whether the N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is a useful biomarker in predicting cardiovascular congestion, mortality, and cardiovascular death and event in chronic peritoneal dialysis (PD) patients. A prospective cohort study was conducted in 230 chronic PD patients in a dialysis unit of a university teaching hospital. Serum NT-pro-BNP was measured at baseline together with echocardiography and dialysis indices. Each patient was followed for 3 yr from the day of enrollment or until death. Time to develop first episode of cardiovascular congestion and other cardiovascular event and time to mortality and cardiovascular death were studied in relation to NT-pro-BNP. NT-pro-BNP showed the strongest correlation with residual GFR, followed by left ventricular ejection fraction and left ventricular mass index. In the univariate Cox regression model, NT-pro-BNP was a significant predictor of cardiovascular congestion, mortality, and cardiovascular death and event. In the fully adjusted multivariable Cox regression analysis that included residual GFR, left ventricular ejection fraction, and left ventricular mass index, the hazard ratios for cardiovascular congestion, mortality, composite end point of mortality and cardiovascular congestion, and cardiovascular death and event for patients of the fourth quartile were 4.25 (95% confidence interval [CI] 1.56 to 11.62; P = 0.005), 4.97 (95% CI 1.35 to 18.28; P = 0.016), 5.03 (95% CI 2.07 to 12.26; P < 0.001), 7.50 (95% CI 1.36 to 41.39; P = 0.021), and 9.10 (95% CI 2.46 to 33.67; P = 0.001), respectively, compared with the first quartile. These data showed that NT-pro-BNP is an important risk predictor of cardiovascular congestion, mortality, and adverse cardiovascular outcomes in chronic PD patients and adds important prognostic information beyond that contributed by left ventricular hypertrophy, systolic dysfunction, and other conventional risk factors.

Adult↗

PubMed2006

Preparation, structures and electrochemical property of phosphine substituted diiron azadithiolates relevant to the active site of Fe-only hydrogenases.

Mono- and di-phosphine diiron azadithiolate complexes [{(mu-SCH(2))(2)N(4-NO(2)C(6)H(4))}Fe(2)(CO)(5)(PMe(3))] (2), [{(mu-SCH(2))(2)N(4-NO(2)C(6)H(4))}{Fe(CO)(2)L}(2)] (3, L=PMe(3); 4, PMe(2)Ph) and the mu-hydride diiron complex [3(FeHFe)](+)[PF(6)](-) were prepared as biomimetic models of the active site of Fe-only hydrogenases. The complexes 2-4 and [3(FeHFe)](+)[PF(6)](-) were characterized by IR, (31)P, (1)H and (13)C NMR spectra and their molecular structures were determined by single crystal X-ray analyses. The PMe(3) ligand in complex 2 lies on the basal position. The PMe(3)-disubstituted complex 3 exists as two configuration isomers, transoid basal/basal and apical/basal, in the crystalline state, while two PMe(2)Ph ligands of 4 are in an apical/basal orientation. The variable temperature (31)P NMR spectra of 2 and 3 were made to have an insight into the existence of the possible conformation isomers of 2 and 3 in solution. The [3(FeHFe)](+) cation possesses the sole transoid ba/ba geometry as other reported mu-hydride diiron analogues. The electrocatalytic property of {(mu-SCH(2))(2)NC(6)H(5)}[Fe(CO)(2)PMe(3)](2) (5) was studied for proton reduction in the presence of HOAc.

Aza Compounds↗

PubMed2006

Role of the Akt/FoxO3a pathway in TGF-beta1-mediated mesangial cell dysfunction: a novel mechanism related to diabetic kidney disease.

Diabetic nephropathy (DN) is characterized by mesangial cell (MC) expansion and accumulation of extracellular matrix proteins. TGF-beta is increased in MC under diabetic conditions and in DN and activates key signaling pathways, including the phosphoinositide-3-kinase/Akt (PI3K/Akt) pathway. FoxO transcription factors play roles in cell survival and oxidative stress and are negatively regulated by Akt-mediated phosphorylation. We tested whether phosphorylation-mediated inactivation of FoxO3a by TGF-beta can mediate MC survival and oxidative stress. TGF-beta treatment significantly increased levels of p-Akt (activation) and p-FoxO3a (inactivation) in cultured MC. This FoxO3a inactivation was accompanied by significant decreases in the expression of two key FoxO3a target genes, the proapoptotic Bim and antioxidant manganese superoxide dismutase in MC. TGF-beta treatment triggered the nuclear exclusion of FoxO3a, significantly inhibited FoxO3a transcriptional activity, and markedly protected MC from apoptosis. A PI3K inhibitor blocked these TGF-beta effects. It is interesting that p-Akt and p-FoxO3A levels also were increased in renal cortical tissues from rats and mice at 2 wk after the induction of diabetes by streptozotocin, thus demonstrating in vivo significance. In summary, TGF-beta and diabetes can increase FoxO3a phosphorylation and transcriptional inactivation via PI3K/Akt. These new results suggest that Akt/FoxO pathway regulation may be a novel mechanism by which TGF-beta can induce unopposed MC survival and oxidant stress in early DN, thereby accelerating renal disease.

Animals↗

PubMed2006

Comparison of 99mTc-DTPA renal dynamic imaging with modified MDRD equation for glomerular filtration rate estimation in Chinese patients in different stages of chronic kidney disease.

BACKGROUND: The renal dynamic imaging method (modified Gate's method) with (99m)Tc-diethylene triamine pentaacetic acid ((99m)Tc-DTPA) is simple and less time consuming for glomerular filtration rate (GFR) estimation than other methods. However, its diagnostic performance as a surrogate marker of GFR is questioned increasingly. Recently, the modified Modification of Diet in Renal Disease (MDRD) study equation based on data from Chinese patients of chronic kidney disease (CKD) showed significant performance improvement. In the present study, the renal dynamic imaging methods and the modified abbreviated MDRD equation were compared with the plasma clearance method. METHODS: Four hundred and eighty two patients with CKD were selected. GFR were estimated simultaneously using three methods: (i) modified Gate's method (gGFR); (ii) the modified abbreviated MDRD equation (c-aGFR) and (iii) dual plasma sampling method (rGFR). Using rGFR as the reference method, gGFR and c-aGFR were compared with rGFR in each stage of CKD. RESULTS: Both gGFR and c-aGFR were correlated well with rGFR (r(gGFR) = 0.81 and r(c-aGFR) = 0.90, P < 0.001). In the overall performance, c-aGFR had less bias (849.5 vs 933.1 arbitrary units), higher precision (57 vs 78.4 ml/min/1.73 m(2)) and higher accuracy than gGFR. For gGFR, the 15, 30 and 50% accuracies were 32.4, 56.0 and 79.1%, respectively; for c-aGFR, the corresponding accuracy rose to 43.2%, 75.5% and 90.9%, respectively. In each stage of CKD, the modified abbreviated MDRD equation also outperformed the modified Gate's method in the GFR estimation. CONCLUSION: Our results indicated that the performance of the renal dynamic imaging in total GFR estimation was not better than the modified abbreviated MDRD equation in our patient group, and should not be used as a surrogate marker of GFR, especially in clinical trials. We presume that the dynamic renal imaging methods for estimation of GFR can be improved by using proper reference GFR, more adequate background subtraction and soft-tissue attenuation correction, in a relatively larger sample size.

Asian People↗

PubMed2006

Modified glomerular filtration rate estimating equation for Chinese patients with chronic kidney disease.

The Modification of Diet in Renal Disease (MDRD) equations provide a rapid method of assessing GFR in patients with chronic kidney disease (CKD). However, previous research indicated that modification of these equations is necessary for application in Chinese patients with CKD. The objective of this study was to modify MDRD equations on the basis of the data from the Chinese CKD population and compare the diagnostic performance of the modified MDRD equations with that of the original MDRD equations across CKD stages in a multicenter, cross-sectional study of GFR estimation from plasma creatinine, demographic data, and clinical characteristics. A total of 684 adult patients with CKD, from nine geographic regions of China were selected. A random sample of 454 of these patients were included in the training sample set, and the remaining 230 patients were included in the testing sample set. With the use of the dual plasma sampling (99m)Tc-DTPA plasma clearance method as a reference for GFR measurement, the original MDRD equations were modified by two methods: First, by adding a racial factor for Chinese in the original MDRD equations, and, second, by applying multiple linear regression to the training sample and modifying the coefficient that is associated with each variable in the original MDRD equations and then validating in the testing sample and comparing it with the original MDRD equations. All modified MDRD equations showed significant performance improvement in bias, precision, and accuracy compared with the original MDRD equations, and the percentage of estimated GFR that did not deviate >30% from the reference GFR was >75%. The modified MDRD equations that were based on the Chinese patients with CKD offered significant advantages in different CKD stages and could be applied in clinical practice, at least in Chinese patients with CKD.

Algorithms↗

PubMed2006

Analysis of bacterial strains with pyrolysis-gas chromatography/differential mobility spectrometry.

Eight vegetative bacterial strains and two spores were characterized by pyrolysis-gas chromatography with differential mobility spectrometry (py-GC/DMS) yielding topographic plots of ion intensity, retention time, and compensation voltage simultaneously for ions in positive and negative polarity. Biomarkers were found in the pyrolysate at characteristic retention times and compensation voltages and were confirmed by standard addition with GC/MS analyses providing discrimination between Gram negative and Gram positive bacterial types, but no recognition of individual strains within the Gram negative bacteria. Principal component analysis was applied using two dimensional data sets of ion intensity versus retention time at five compensation voltages including the reactant ion peaks all in positive and negative ion polarity. Clustering was observed with compensation voltage (CV) chromatograms associated with ion separation in the DMS detector and little or no clustering was observed with the reactant ion peaks or CV chromatograms where ion separation is poor. Consistent clustering of Gram positive B. odysseyi and Gram negative E. coli in both positive and negative polarities with the reactant ion peak chromatograms and key CV chromatograms suggests common but unknown common chemical compositions in the pyrolysate.

Bacteria↗

PubMed2006

Cardiovascular disease in early stages of chronic kidney disease in a Chinese population.

Cardiovascular disease (CVD) is one of the most serious complications of kidney disease, yet studies of CVD in early stage of chronic kidney disease (CKD) in Asian patients are very limited. Therefore, this study determined the prevalence and the spectrum of CVD in individuals with early-stage CKD and compared them with data of individuals without CKD. Compared with individuals with estimated GFR (eGFR) >90 ml/min per 1.73 m2, the prevalence of myocardial infarction, stroke, and total CVD of individuals with eGFR 60 to 89 ml/min per 1.73 m2 was increased by 91.4, 71.7, and 67.6%, respectively. For individuals with eGFR 30 to 59 ml/min per 1.73 m2, the percentage was 105.2, 289.1, and 200.7%, respectively. For each eGFR category, stroke was more prevalent than myocardial infarction. Compared with individuals with eGFR >90 ml/min per 1.73 m2, participants with eGFR 60 to 89 and 30 to 59 ml/min per 1.73 m2 tended to have more cardiovascular risk factors, and there were strong unadjusted and adjusted associations between CVD with different stages of eGFR (eGFR >90 ml/min per 1.73 m2 as reference). This is the first report on the prevalence and the spectrum of CVD in early stages of CKD in a community-based Chinese population. The spectrum of CVD in this Chinese population is different from reports of Western countries. Individuals with subtle decreased renal function seem much more likely to have multiple cardiovascular risk factors and have higher prevalence of CVD than those without CKD.

Adult↗

PubMed2006

Analysis of MYOC gene mutation in a Chinese glaucoma family with primary open-angle glaucoma and primary congenital glaucoma.

BACKGROUND: Glaucoma is one of the leading causes of blindness in the world. Primary open-angle glaucoma (POAG) and primary congenital glaucoma (PCG) are subtypes of glaucoma. Myocillin is the first gene identified to be involved in POAG. Recently, myocillin mutation has been found in PCG. In this context, we reported a special glaucoma pedigree, which was composed of both PCG and POAG patients, and analyzed the mutation of myocillin in this pedigree. METHODS: The family was composed of the parents, a son and a daughter. All members of the family underwent the complete ophthalmologic examinations. All coding exons 1 - 3 and flanking introns of myocilin gene were screened for sequence alterations by polymerase chain reaction and direct DNA sequencing. RESULTS: The son was the proband, who was diagnosed as PCG in both eyes. The father was diagnosed as POAG in the right eye, the left eye was still normal. Both the sister and the mother of the proband had normal intraocular pressure without glaucomatous optic disc changes. The mutations in intron 2 of myocilin gene were detected in the family. While the proband and the father were homozygous, the mother and the sister were heterozygous for the mutation. CONCLUSIONS: Homozygous mutation in intron 2 of myocilin gene is involved in both POAG and PCG. It is suggested that the pathogenesis might be overlapping in POAG and PCG.

Cytoskeletal Proteins↗

PubMed2006

Atrial strain rate echocardiography can predict success or failure of cardioversion for atrial fibrillation: a combined transthoracic tissue Doppler and transoesophageal imaging study.

AIMS: The purpose of this study was to assess the feasibility of measuring left atrial dysfunction with tissue Doppler imaging derived strain rate and to explore its role in predicting the maintenance of sinus rhythm after cardioversion for atrial fibrillation. METHODS AND RESULTS: Strain rate (SR) and tissue Doppler imaging (TDI) were performed with offline analysis of the basal left atrial wall (LA). SR detected a systolic (Ssr) and early diastolic (Esr) deformation induced by ventricular motion. LA dimensions and volume were measured. Left atrial appendage emptying (LAA_EV) and filling (LAA_FV) velocities were also obtained by transesophageal echocardiography. 27 healthy age-matched controls and 42 patients with AF before cardioversion were studied. Patients were grouped into (1): those who remained in sinus rhythm (group S, n=12) and (2) those who either failed cardioversion or reverted to AF within 4 weeks (group F, n=30). LA dimensions were significantly larger and atrial Esr was significantly lower in group F than group S (all p<0.01). LAA_EV and LAA_FV were not different between groups S and F. Multivariate regression analysis showed that a lower Esr and larger transverse LA diameter (LADtr) were independent predictors of failure of cardioversion (HR, 95% CI: 0.36, 0.14-0.88 and 2.85, 1.33-6.10, respectively). Esr combined with LADtr improved the sensitivity and specificity for predicting successful cardioversion. CONCLUSIONS: SR can be measured in the basal LA wall in atrial fibrillation and the magnitude of the early diastolic SR could predict the success of cardioversion and the likelihood of maintenance of sinus rhythm.

Adult↗

PubMed2006

Repair of infarcted myocardium by an extract of Geum japonicum with dual effects on angiogenesis and myogenesis.

BACKGROUND: It has become apparent recently that cardiac myocytes can divide after myocardial infarction, a circumstance that challenges the orthodox view that myocytes may be terminally differentiated. Replacement of the necrosed heart tissue by newly regenerated functional myocardium is a therapeutic ideal, but attempts to reconstitute functional myocardia and coronary vessels have been less successful. METHODS: We isolated a fraction containing 5 compounds from the Chinese herb Geum japonicum, which stimulates the processes of angiogenesis and cardiomyogenesis. We investigated these dual properties in both ex vivo and in vivo systems. RESULTS: We observed that this bioactive fraction displayed favorable dual actions on early angiogenesis and cardiomyogenesis in acute myocardial infarction in an animal model. Our results demonstrated that application of this bioactive fraction showed pronounced effects on limiting infarct size by 35%-45%, stimulating early development of new blood vessels in 24 h, and regenerating myocardium, replacing approximately 49% of the total infarction volume after 2 weeks. Echocardiographic studies demonstrated marked improvement of left ventricular function within 2 days after infarction, and the improvement was sustained for >1 month. CONCLUSIONS: The properties of this bioactive fraction appear to be entirely novel and represent a new approach for the treatment of ischemic heart disease.

Animals↗

PubMed2006

Mono- and binuclear complexes of iron(II) and iron(III) with an N4O ligand: synthesis, structures and catalytic properties in alkane oxidation.

Three mononuclear iron complexes and one binuclear iron complex, [Fe(tpoen)Cl].0.5(Fe2OCl6) (1), [Fe(tpoen)Cl]PF6 (2), Fe(tpoen)Cl3 (3) and [[Fe(tpoen)]2(mu-O)](ClO4)4 (4) (tpoen = N-(2-pyridylmethoxyethyl)-N,N-bis(2-pyridylmethyl)amine), were synthesized as functional models of non-heme iron oxygenases. Crystallographic studies revealed that the Fe(II) center of 1 is in a pseudooctahedral environment with a pentadentate N4O ligand and a chloride ion trans to the oxygen atom. The Fe(III) center of 3 is ligated by three nitrogen atoms of tpoen and three chloride ions in a facial configuration. Each Fe(III) center of 4 is coordinated with four nitrogen atoms and an oxygen atom of tpoen with the Fe-O-Fe angle of 172.0(3) angstroms. Complexes 2, 3 and 4 catalysed the oxidation of cyclohexane with H2O2 in the total TNs of 24-36 with A/K ratios of 1.9-2.4. Under the same conditions they also catalysed both the oxidation of ethylbenzene to benzylic alcohol and acetobenzene with good activity (30-47 TN) and low selectivity (A/K 0.7), and the oxidation of adamantane with moderate activity (15-18 TN) and low regioselectivity (3 degrees/2 degrees 3.0-3.2). With mCPBA as oxidant the catalytic activities of 2, 3 and 4 increased 1.8 to 2.3-fold for the oxidation of cyclohexane and ethylbenzene and 6.3 to 7.5-fold for the oxidation of adamantane. Drastic enhancement of the regioselectivity was observed in the oxidation of adamantane (3 degrees/2 degrees 18.5-30.3).

Journal Article↗

PubMed2006

Improving the management of anemia in hemodialysis patients by implementing the continuous quality improvement program.

BACKGROUND: Anemia is common in hemodialysis patients, and improvement in anemia management is possible with the implementation of continuous quality improvement (CQI) programs. The aim of this study is to improve anemia management in chronic hemodialysis patients using CQI. METHODS: Ninety hemodialysis patients in our single center were enrolled in the study. The patients were followed up from January 2004 to October 2005. The CQI team-oriented approach was driven by a process called the 'FOCUS-PDCA cycle plan' (find, organize, clarify, uncover, start, plan, do, check and act). Hemoglobin (Hb), serum ferritin and transferrin saturation were monitored periodically. RESULTS: By implementation of the CQI program, the proportion of patients with Hb >or=110 g/l increased from 42.2 to 60.0% (p < 0.05), and the Hb level increased from 101.2 +/- 18.05 to 110.4 +/- 14.23 g/l (p < 0.0001). The proportion of patients with an adequate iron status increased from 28.0 to 53.3% (p < 0.05). CONCLUSION: The CQI program is a useful method in the management of anemia in hemodialysis patients.

Adult↗

PubMed2006

Clinicogenetic study of mutations in LRRK2 exon 41 in Parkinson's disease patients from 18 countries.

We screened LRRK2 mutations in exon 41 in 904 parkin-negative Parkinson's disease (PD) patients (868 probands) from 18 countries across 5 continents. We found three heterozygous missense (novel I2012T, G2019S, and I2020T) mutations in LRRK2 exon 41. We identified 11 (1.3%) among 868 PD probands, including 2 sporadic cases and 8 (6.2%) of 130 autosomal dominant PD families. The LRRK2 mutations in exon 41 exhibited relatively common and worldwide distribution. Among the three mutations in exon 41, it has been reported that Caucasian patients with G2019S mutation have a single-founder effect. In the present study, Japanese patients with G2019S were unlikely to have a single founder from the Caucasian patients. In contrast, I2020T mutation has a single-founder effect in Japanese patients. Clinically, patients with LRRK2 mutations had typical idiopathic PD. Notably, several patients developed dementia and psychosis, and one with I2020T had low cardiac (123)I-metaiodobenzylguanidine (MIBG) heart/mediastinum ratio, although the ratio was not low in other patients with I2020T or G2019S. Clinical phenotypes including psychosis, dementia, and MIBG ratios are also heterogeneous, similar to neuropathology, in PD associated with LRRK2 mutations.

Antiparkinson Agents↗

PubMed2006

Prolonging the ultrasound signal enhancement from thrombi using targeted microbubbles based on sulfur-hexafluoride-filled gas.

RATIONALE AND OBJECTIVES: The objective of this study is to develop and characterize new microbubbles based on lipids and sulfur hexafluoride (SF6) for targeting thrombi as an improved ultrasound contrast agent. MATERIALS AND METHODS: Bioconjugate ligands were inserted into the lipid-coated membranes of SF6 gas microbubbles, and their physicochemical properties were determined. Diagnostic efficacies of SF6-filled microbubbles and the contrast agent SonoVue (Bracco Imaging, Geneve, Switzerland) were compared in dogs. RESULTS: Suspensions of lyophilized powder were reconstituted by injecting saline containing 3.1 x 10(8) SF6 microbubbles/mL with a mean diameter of 4.4 microm. More than 90% of microbubbles had diameters between 1 and 10 microm. After reconstitution, echogenicity and microbubble characteristics were unchanged for 8 hours. Targeted microbubbles increased the echogenicity of thrombi significantly and provided a longer period of optimal signal enhancement compared with nontargeted microbubbles. CONCLUSIONS: Our thrombus-targeting microbubble contrast agent shows high echogenicity and stability and thereby enhances the visualization of intravascular thrombi and prolongs the duration of the diagnostic window.

Animals↗

PubMed2006

An upper extremity kinematic model for evaluation of hemiparetic stroke.

Quantification of rehabilitation progress is necessary for accurately assessing clinical treatments. A three-dimension (3D) upper extremity (UE) kinematic model was developed to obtain joint angles of the trunk, shoulder and elbow using a Vicon motion analysis system. Strict evaluation confirmed the system's accuracy and precision. As an example of application, the model was used to evaluate the upper extremity movement of eight hemiparetic stroke patients with spasticity, while completing a set of reaching tasks. Main outcome measures include kinematic variables of movement time, range of motion, peak angular velocity, and percentage of reach where peak velocity occurs. The model computed motion patterns in the affected and unaffected arms. The unaffected arm showed a larger range of motion and higher angular velocity than the affected arm. Frequency analysis (power spectrum) demonstrated lower frequency content for elbow angle and angular velocity in the affected limb when compared to the unaffected limb. The model can accurately quantify UE arm motion, which may aid in the assessment and planning of stroke rehabilitation, and help to shorten recovery time.

Adult↗