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Biomedical subjects

Mei Wang

Publications and source records attributed to Mei Wang.

At least 55 records · Page 3Linked to original sources
PubMed2006

[Expressions of RhoC and osteopontin in esophageal squamous carcinoma and association with the patients' prognosis].

OBJECTIVE: To investigate the expressions of RhoC and osteopontin (OPN) protein in esophageal squamous carcinoma (ESC) and their association with the biological behavior of ESC. METHODS: The expressions of RhoC and OPN protein were detected in 80 ESC cases by immunohistochemistry. RESULTS: The positive expression rate of RhoC was 66.25% in these ESC cases. The rate was significantly higher in cases with lymph node metastasis than in those without (r(s)=-2.115, P<0.05), but RhoC expression was not associated with the tumor diameter, differentiation or TNM grade (P>0.05). The RhoC-positive patients had significantly shorter survival time than the negative patients (P<0.001). All the 80 ESC patients were positive for OPN expression, and OPN expression levels were correlated with the differentiation (chi(2)=10.766, P<0.05) and lymph node metastasis of the tumor (r(s)=-2.289, P<0.05), but not with the tumor diameter or TNM grade (P>0.05). Higher expression level of OPN was closely related to shorter survival time of the patients (P<0.05). A positive correlation was found between RhoC protein and OPN expressions (r(s)= 0.408, P<0.001) in these cases. CONCLUSION: The expressions of RhoC and OPN protein are closely related to lymph node metastasis of ESC and the patients survival time, and therefore may serve the purpose of prognostic evaluation of ESC.

Adult↗
PubMed2006

[Difference between FOXP3 gene expressions in donor grafts with or without acute graft-versus-host disease].

The study was aimed to investigate the association of FOXP3 gene expression in donor grafts with acute graft-versus-host disease after HLA-identical sibling allogeneic hematopoietic stem cell transplantation. Twenty-six donor grafts (peripheral blood or bone marrow) and their respective clinical characteristics were evaluated. Flow cytometry analysis was performed to assess the percentage of CD4+CD25+ and CD4+CD25(high) T cells in cord blood, healthy controls' peripheral blood and donor grafts. Relative transcripts of FOXP3 mRNA were determined by real-time quantitative reverse transcription -polymerase chain reaction with beta2-MG as the internal control gene. The specificity of FOXP3 and beta2-MG amplifications was confirmed by analyzing the dissociation curves and electrophoresis of the target amplicon. The results showed that the CD4+CD25+ T cells in peripheral blood, peripheral blood stem cell (PBSC) or BM grafts exhibited a continuous and primarily low expression of CD25 and the frequencies of CD4+CD25+ T and CD4+CD25(high) T in CD4+ T cells were (48.5 +/- 16.3)% and (9.6 +/- 2.5)%, (42.1 +/- 14.7)% and (13.1 +/- 4.2)%, (43.4 +/- 9.6)% and (14.6 +/- 4.5)%, respectively. There was no significant difference in the frequencies and absolute numbers of CD4+CD25(high) T cells between patients with aGVHD and patients without aGVHD (P > 0.05). The plot of log transfused cDNA amount versus DeltaCt had a slope of 0.0826 which indicated approximately equal efficiency of FOXP3 and beta2-MG amplifications in real-time PCR. The specificities of amplification were confirmed by analyzing the dissociation curves and electrophoresis of PCR products with the values of Tm 86.5 degrees C and 82.3 degrees C, respectively. The relative transcripts of FOXP3 in PBSC grafts of recipients without aGVHD were 318%high as those with aGVHD (median of 41.0 x 10(-5) and 12.9 x 10(-5), respectively) (P = 0.03). No significant difference was found in other related variables for GVHD. It is concluded that coexpression of CD4 and CD25 may be insufficient to identify regulatory T cells; FOXP3 mRNA expression may be specifically quantified with real-time quantitative RT-PCR using SYBR Green I chemistry. FOXP3 mRNA expression in donor grafts is significantly low in patients with aGVHD compared with patients without aGVHD. It indicated that the expression level of FOXP3 mRNA may be one of the useful indicators for in predicting aGVHD.

Adolescent↗
PubMed2005

Cycles of chromosome instability are associated with a fragile site and are increased by defects in DNA replication and checkpoint controls in yeast.

We report here that a normal budding yeast chromosome (ChrVII) can undergo remarkable cycles of chromosome instability. The events associated with cycles of instability caused a distinctive "sectoring" of colonies on selective agar plates. We found that instability initiated at any of several sites on ChrVII, and was sharply increased by the disruption of DNA replication or by defects in checkpoint controls. We studied in detail the cycles of instability associated with one particular chromosomal site (the "403 site"). This site contained multiple tRNA genes known to stall replication forks, and when deleted, the overall frequency of sectoring was reduced. Instability of the 403 site involved multiple nonallelic recombination events that led to the formation of a monocentric translocation. This translocation remained unstable, frequently undergoing either loss or recombination events linked to the translocation junction. These results suggest a model in which instability initiates at specific chromosomal sites that stall replication forks. Forks not stabilized by checkpoint proteins break and undergo multiple rounds of nonallelic recombination to form translocations. Some translocations remain unstable because they join two "incompatible" chromosomal regions. Cycles of instability of this normal yeast chromosome may be relevant to chromosome instability of mammalian fragile sites and of chromosomes in cancer cells.

Cell Cycle Proteins↗
PubMed2005

[Comparison of single plasma sample methods and prediction of dual plasma sample method in measurement of 99mTc-Diethylene Triamine Pentaacetic Acid plasma clearance].

OBJECTIVE: To find an applicable condition of the single-plasma-sample method (SPSM) to measure the glomerular filtration(GFR) with (99m)Tcj Diethylene Triamine Pentaacetic Acid ((99m)Tc-DTPA), and predict the value of (99m)Tc-DTPA plasma clearance by dual plasma sample method (DPSM ) from that by SPSM. METHODS: Three hundred and thirty five patients with chronic kidney disease (CKD) were selected (192 males and 143 females). The average age was 51.91+/-14.76 years. The GFR was determined simultaneously by 2 methods: (1) SPSM (sGFR); (2) DPSM (tGFR), using DPSM as reference standard, sGFR calculated from the different SPSM was compared with tGFR. An equation was developed to predict tGFR from sGFR. GFR estimated by abbreviated Modification of Diet in Renal Disease (MDRD) equation (aGFR) was evaluated as the criterion in selection of DPSM and SPSM. The condition that DPSM could be substituted by SPSM in GFR measurement was given. RESULTS: When tGFR >or= 30 mL/(minx1.73 m(2)), all of the sGFR were significantly correlated with tGFR. Among them, Watson modified Christensen and Groth's equation at sample time=240 min tended to be the most accurate (r=0.977, RMSE=10.91), and tGFR could be predicted from sGFR using the equation: Predicted tGFR [mL/(minx1.73 m(2))]=7.755 4+0.789 3xsGFR+0.002 4 xsGFR2 (n=297, r2=0.959 1, P<0.001). When aGFR was less than 50 mL/(minx1.73 m(2)), the diagnostic sensitivity of tGFR<30 mL/(minx1.73 m(2)) was 94.7%, and recommended as the criterion in selection of DPSM and SPSM. CONCLUSION: When aGFR >or=50 mL/(minx1.73 m(2)), DPSM can be substituted by SPSM in GFR measurement.

Algorithms↗
PubMed2005

Does anterior plating of the cervical spine predispose to adjacent segment changes?

STUDY DESIGN: In a human cadaveric model, the effects of plate supplementation on the mechanical behaviors of adjacent segments were investigated. OBJECTIVES: The objective was to determine the effects of anterior cervical fusion and plating on the adjacent segments. SUMMARY OF BACKGROUND DATA: Increases in intradiscal pressure and intervertebral motion at adjacent segments have been reported in the lumbar spine following an instrumented fusion. It is unclear if the same phenomenon presents in the cervical spine. METHODS: Seven human cadaveric cervical spines (C2-T1) were used, and fusion of the C5-C6 segment was chosen for the purpose of this study. Two miniature pressure transducers were implanted within each adjacent disc. Flexion, extension, lateral bending, and torsion loads up to 2.5 Nm were applied to the intact spine, and following each of the two procedures, anterior discectomy and grafted fusion, and anterior plating of the C5-C6 motion segment. RESULTS: At the surgical level, a significant increase in segmental stiffness was observed after plating in all directions. Following the grafted fusion, there were no statistically significant changes at the superior adjacent segment, and there was a 13.7% increase in axial rotation in the inferior adjacent segment. Once anterior plating was applied, slight increase (<12%) over the intact spines was noted in lateral bending in both adjacent segments. However, there was no significant difference between the grafted fusion and anterior plated fusion at either adjacent segment. At both adjacent disc levels, the differences in intradiscal pressures between grafted fusion and plated fusion were less than 30% in all directions, and none of these differences was statistically significant. CONCLUSIONS: Intradiscal pressures and intervertebral motion at the adjacent levels are not significantly affected by the instrumented anterior fusion. The clinically observed degenerative change at adjacent segments in the cervical spine is more likely to be attributed to natural progression of the spondylotic process as opposed to biomechanical effect of the instrumentation or fusion.

Aged↗
PubMed2005

Biomechanical changes at adjacent segments following anterior lumbar interbody fusion using tapered cages.

STUDY DESIGN: A biomechanical evaluation of anterior cages in a calf lumbar spine model. OBJECTIVES: To determine changes in spinal motion and intradiscal pressures at immediately adjacent lumbar motion segments following anterior insertion of tapered cages. SUMMARY OF BACKGROUND DATA: Stand-alone anterior lumbar interbody fusion (ALIF) is an effective approach in the treatment of discogenic low back pain. A tapered lumbar (LT) cage design attempts to restore physiologic lordosis and sagittal balance. We are not aware of any previous biomechanical evaluation of the effects of LT cages on adjacent motion segments. METHODS: Nine fresh calf spines (L2-L5) were procured for the study. Pure moments (up to 8.5 Nm) in flexion, extension, and lateral bending were applied to the L2 vertebra in five steps through a nonconstrained loading system. With each step of loading, three-dimensional rotation at three intervertebral disc levels was obtained through a three-camera motion analysis system, and intradiscal pressures within the nucleus pulposus of the two nonoperated discs were measured with miniature transducers. The spines were tested initially intact and following paired anterior LT cage insertion. RESULTS: Following ALIF, small to moderate increase in motion was found at both adjacent segments in flexion (superior: 12.5%, P < 0.05; inferior: 11.3%, P < 0.02) and lateral bending (superior: 7.8%, P < 0.02; inferior: 6.6%, P < 0.02). An increase in intradiscal pressure was noted at the superior adjacent segment under flexion (21%, P < 0.01) and lateral bending (16%, P < 0.03). Intradiscal pressure changes at the inferior adjacent level were not significant. CONCLUSIONS: Statistically significant changes in intradiscal pressures and motion were found at the adjacent levels following a single-level stand-alone ALIF procedure using paired LT cages.

Animals↗
PubMed2005

Observation of circulating tumour cells in patients with non-small cell lung cancer by real-time fluorescent quantitative reverse transcriptase-polymerase chain reaction in peroperative period.

PURPOSE: To assess whether surgical manoeuvre or resection of lung cancer could lead to haematogenous dissemination of malignant cells. In the mean time, the relationship between the sequence of vessel ligation and the haematogenous dissemination of cancer cells during operation was determined. METHODS: Exploiting cytokeratin 19 (CK19)/carcinoembryonic antigen (CEA) mRNA as markers, 69 peripheral blood samples were collected from 23 consecutive patients with non-small cell lung cancer (NSCLC) who underwent surgical resection with curative intention in preoperative, intraoperative and postoperative period, respectively. Before the operation, all patients were randomly assigned to one of the two surgical procedure groups according to the order of vessel ligation, PV-first group and PA-first group. Additionally, the ten patients with benign lung disease served as control subjects undergoing surgical resection. The quantity and timing of the shedding of lung cancer cells into the circulation of patients were also monitored by fluorescent quantitative-reverse transcriptase-polymerase chain reaction before, during and after surgery. RESULTS: (1) The CK19 diagnostic test: the value of CK19 mRNA in operation was significantly higher than that of preoperation (5.246+/-0.196 vs. 4.472+/-0.164, P=0.000) and postoperation (5.246+/-0.196 vs. 4.694+/-0.177, P=0.013). The values between adenocarcinoma and squamous carcinoma were strikingly different (4.9110+/-1.0315 vs. 4.1891+/-0.4126, t=2.364, P=0.028). The values between PV-first group and PA-first group during perioperative period appear to be different (4.503 vs. 5.085, P=0.086). Before operation, of the 23 cases studied, 14 cases were positive (60.9%). Surprisingly, circulating epithelial cells were detected in two patients resected for benign lung disease. (2) The CEA diagnostic test: the level of CEA mRNA ascended continuously within this period. The postoperative values were significantly higher than those of preoperation (4.874 vs. 4.483, P=0.000) and those of operative day (4.874 vs. 4.537, P=0.000). The values between PV-first group and PA-first group appear to reach statistical significance (4.397 vs. 4.817, P=0.075). At the same time, there was a correlation between preoperative T-stage and perioperative CEA mRNA (4.267 vs. 4.760, P=0.025). Among the 23 cases, 10 cases were positive (43.5%). Both patients with benign lung disease served as control subjects undergoing surgical resection and the volunteers were negative. CONCLUSIONS: A considerable proportion of patients who appear to have resectable NSCLC might be regarded as having systemic disease, which is often undetectable by current tumour staging method. In terms of a marker used for the NSCLC patients who undergo operation, CEA is more suitable than CK19. The CK19-expressing epithelial cells are released intraoperatively into the circulation, meanwhile CEA-expressing tumour cells are disseminated mostly postoperatively. Surgical manipulation could promote the release of tumour cells into the bloodstream, but the ligation of pulmonary vein before the ligation of the pulmonary artery may partly prevent such release during surgery.

Aged↗
PubMed2005

[Multianalysis of short-term prognostic factors in surgical practices for hypertensive intracerebral hemorrhage].

OBJECTIVE: To evaluate and compare the effectiveness of different types of surgical therapy for patients with hypertensive cerebral hemorrhage, and analyze the major risk factors of prognosis. METHODS: 2464 patients with hypertensive cerebral hemorrhage in 92 hospitals in different areas of China underwent different types of surgical treatment: Group I (n = 639), undergoing traditional craniotomy as control; Group II (n = 409), receiving minimally invasive hematoma evacuation; and Group III (n = 1416), receiving CT guided stereotaxic hematoma aspiration. The clinical data were collected and underwent multianalysis. RESULTS: The factors influencing the short-term prognosis were Glasgow coma scale (GCS) score before surgery and the incidence of postoperative complications in Group II; GCS score before surgery and the incidence of postoperative complications and volume of hemorrhage, duration between ictus and surgery, use of urokinase in Group III; and GCS score before surgery, muscle power before surgery, diastolic pressure at admission and postoperative complications in Group III. CONCLUSION: Analysis of prognosis related factors of cerebral hemorrhage plays a very important role in the selection of therapeutic strategy. It may be beneficial for standardizing surgical indications, further designing large scale clinical trial, helping the doctors select appropriate strategy of treatment, and serving the social population better.

Adolescent↗
PubMed2005

Cell division and morphology of the marine ciliate, Condylostoma spatiosum Ozaki and Yagiu (Ciliophora, Heterotrichida) based on a Chinese population.

The morphology and morphogenesis of the large marine heterotrichous ciliate, Condylostoma spatiosum Ozaki & Yagiu in Yagiu, 1944, isolated from Jiaozhou Bay off Qingdao (Tsingtao), China, were investigated using live observation and protargol impregnation. A detailed redescription is given since no infraciliature data about this "well-studied" species are available. It is characterized by: size in vivo 400-700 x 90-140 microm; buccal field about 1/3 of body length; adoral zone composed of 130 membranelles on average; invariably two prominent membrane-like frontal cirri, which are parallel to each other; about 58 somatic kineties; macronucleus composed of 13-22 fragments. Morphogenesis proceeds basically as described in a previous report and can be summarized as follows: (1) the parental adoral zone of membranelles is partly dedifferentiated and then renewed in the posterior portion; (2) in the proter, both the frontal cirri and the paroral membrane are newly formed by anlagen derived from the disaggregated old structures; (3) in the opisthe the anlagen of the paroral membrane and the frontal cirri develop from the right margin of the oral primordium; (4) two frontal cirri are formed one after the other by the frontal cirral anlage; (5) during morphogenesis, no recognizable duplication of basal bodies takes place in somatic kineties; and (6) the macronucleus divides after prior fusion. One reorganizer was observed showing that the basic process of reorganization is obviously similar to that in division.

Animals↗
PubMed2005

Unheated Cannabis sativa extracts and its major compound THC-acid have potential immuno-modulating properties not mediated by CB1 and CB2 receptor coupled pathways.

There is a great interest in the pharmacological properties of cannabinoid like compounds that are not linked to the adverse effects of Delta(9)-tetrahydrocannabinol (THC), e.g. psychoactive properties. The present paper describes the potential immuno-modulating activity of unheated Cannabis sativa extracts and its main non-psychoactive constituent Delta(9)-tetrahydrocanabinoid acid (THCa). By heating Cannabis extracts, THCa was shown to be converted into THC. Unheated Cannabis extract and THCa were able to inhibit the tumor necrosis factor alpha (TNF-alpha) levels in culture supernatants from U937 macrophages and peripheral blood macrophages after stimulation with LPS in a dose-dependent manner. This inhibition persisted over a longer period of time, whereas after prolonged exposure time THC and heated Cannabis extract tend to induce the TNF-alpha level. Furthermore we demonstrated that THCa and THC show distinct effects on phosphatidylcholine specific phospholipase C (PC-PLC) activity. Unheated Cannabis extract and THCa inhibit the PC-PLC activity in a dose-dependent manner, while THC induced PC-PLC activity at high concentrations. These results suggest that THCa and THC exert their immuno-modulating effects via different metabolic pathways.

Cannabis↗
PubMed2005

Geographic and ethnic differences in frequencies of two polymorphisms (D/N394 and L/I272) of the parkin gene in sporadic Parkinson's disease.

In this report, we evaluated the allele frequency of the D/N394 single nucleotide polymorphism (SNP) in exon 11 of the parkin gene in 200 Japanese patients with sporadic Parkinson's disease (PD) and 200 normal controls. Although the reported allele frequency of G-to-A (D/N394) is 2% in Caucasians, this SNP was not detected in Japanese patients and healthy controls. Evaluation of L/I272 polymorphism, a C-to-A transition in exon 7, showed the polymorphism in only six controls, but not in PD patients. Our results suggest that the frequencies of parkin polymorphisms are different among Asians and Caucasians.

Alleles↗
PubMed2005

[The changing etiology and therapeutic situation of atherosclerotic renal artery stenosis].

OBJECTIVE: To determine whether the etiology of renal artery stenosis changed. To investigate the clinical characteristics and current therapeutic situation of atherosclerotic renal artery stenosis (ARAS). METHODS: Retrospective analysis was performed in 144 cases of renal artery stenosis diagnosed by angiography (> or = 50% luminal narrowing) from 1979 to 2003. Eighty-seven of them were diagnosed as ARAS by special characteristics of angiography and clinical features. The clinical data of ARAS was compared with RAS caused by other diseases. RESULTS: The proportion of ARAS in all RAS was 60.4%. The proportion of ARAS was 28.9% during the period of 1980 to 1990 and 71.7% from the year of 1991 to 2003, respectively. The prevalence of hypertension was 90.8% among ARAS patients. Newly-progressive hypertension was more common among ARAS patients compared with RAS patients with other causes (37.9% vs 21.0%, P = 0.044). Renal dysfunction were more commonly seen among ARAS than non-ARAS patients in those with the same degree of stenosis (11.2% vs 6.9% for stenosis 50%-74%, P = 0.038; 35.8% vs 15.4% for stenosis > or = 75%, P = 0.046). Among ARAS cases, 60.9% were managed with antihypertensive agents only, 18.8% were managed by angioplasty with or without stents. After 1990, the improvement rate of blood pressure rose significantly but not for renal function. The improvement rate of blood pressure by angioplasty was similar with that by medication (84.1% vs 92.6% for stenosis 50%-74%, P = 0.39; 76.6% vs 80.1% for stenosis > or = 75%, P = 0.61). And the improvement or stable rate of renal function was not different (85.4% vs 85.7% for stenosis 50%-74%, P = 0.91; 77.8% vs 76.9% for stenosis > or = 75%, P = 0.83). CONCLUSION: ARAS is the predominant cause of RAS nowadays in stead of Takayasu arteritis. Medication is the mostly used management for ARAS, though more angioplasty with or without stents appear. The effect of medication for ARAS has improved since 1990. Most cases of ARAS could achieve ideal blood pressure control and similar renal function protection with either rational medication or angioplasty.

Adult↗
PubMed2005

[Fluid distribution abnormalities and influence of hemodialysis on fluid distribution in patients on maintenance hemodialysis].

OBJECTIVE: To study the fluid distribution abnormalities in patients on hemodialysis and fluid shift between intracellular and extracellular compartment during hemodialysis (HD). METHODS: Eighty stable end stage renal disease patients on maintenance hemodialysis were selected. Conventional low flux dialyses at dialysate sodium concentration of 138 mmoL/L were performed for all of the patients. Fresenius polysulphons or Gambro hemophon dialyzers were used. All of the patients showed no clinical signs of over ultrafiltration during HD sessions and dry body weights were considered adequate. Intracellular water (ICW), extracellular water (ECW) and total body water (TBW) were measured and standardized by body weight (nICW, nECW, nTBW) before and after HD sessions. Sixty-seven cases of sex, age and body weight matched normal individuals were used as controls. Bio-impedance spectrum (BIS) analysis (Xitron, Technologies, San Diego, CA, USA) was used in body fluid measurement. Pre and post HD nICW, nECW, and nTBW were compared with these of the controls. RESULTS: There were no differences in age, post-dialysis body weight and body mass index between patients on hemodialysis and the controls. Patients on hemodialysis had less nICW [male (0.28+/-0.05) vs (0.33+/-0.04), P<0.01; female (0.22+/-0.03) vs (0.27+/- 0.04), P<0.001], more nECW [male (0.28+/-0.02) vs (0.25+/-0.02), P<0.001; female (0.25+/-0.03) vs (0.23+/-0.01), P<0.05], and less nTBW [male (0.56+/-0.04) vs (0.58+/-0.05), P<0.05; female (0.47+/-0.05) vs (0.49+/-0.03), P<0.05] compared with the controls. The average ultra-filtration volume was (2.2+/-0.9)L. After dialysis, there was an increase in nICW [male (0.28+/-0.05) vs (0.30+/-0.05), P<0.001; female (0.22+/-0.03) vs (0.25+/-0.03), P<0.001), an decrease in nECW [male (0.28+/-0.02) vs (0.26+/-0.03), P<0.001; female (0.24+/-0.03) vs (0.21+/-0.03), P<0.001],and decrease of ECW/ICW ratio [male (1.06+/-0.30) vs (0.89+/-0.25) P<0.001; female (1.10+/-0.17) vs (0.88+/-0.17) P<0.001] which reached the levels of the normal individuals (0.79+/- 0.10 for male, 0.86+/-0.10 for female]. CONCLUSION: Our results show that (1) Before HD sessions, patients on HD had less nICW and more nECW; (2) During conventional low flux HD sessions at dialysate sodium concentration of 138 mmoL/L, fluid shifted from extracellular space to intracellular space.(3) nECW and ECW/ICW ratio from normal population are reasonable for evaluation of dry weight in patients on hemodialysis, but nTBW and nICW are not.

Adult↗
PubMed2005

Comparison of bacterial diversity along the human intestinal tract by direct cloning and sequencing of 16S rRNA genes.

Bacterial diversity of the mucosal biopsies from human jejunum, distal ileum, ascending colon and rectum were compared by analysis of PCR-amplified 16S rDNA clone libraries. A total of 347 clones from the mucosal biopsies were partially sequenced and assigned to six phylogenetic phyla of the domain Bacteria: Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria, Verrucomicrobia, and Actinobacteria. The jejunum sample had least microbial diversity compared to the other samples and a trend towards highest diversity in ascending colon was observed. The clone libraries of distal ileum, ascending colon and rectum were not significantly different from each other (P>0.0043), but they differed significantly from the jejunum library (P=0.001). The population of sequences retrieved from jejunal biopsies was dominated by sequences closely related to Streptococcus (67%), while the population of sequences derived from distal ileum, ascending colon and rectum were dominated by sequences affiliated with Bacteroidetes (27-49%), and Clostridium clusters XIVa (20-34%) and IV (7-13%). The results indicate that the microbial community in jejunum is different from those in distal ileum, ascending colon and rectum, and that the major phylogenetic groups are similar from distal ileum to rectum.

Bacteria↗
PubMed2005

Strain rate imaging differentiates transmural from non-transmural myocardial infarction: a validation study using delayed-enhancement magnetic resonance imaging.

OBJECTIVES: The aim of this study was to determine if strain rate imaging (SRI) correlates with the transmural extent of myocardial infarction (MI) measured by contrast-enhanced magnetic resonance imaging (Ce-MRI). BACKGROUND: Identification of the transmural extent of myocardial necrosis and degree of non-viability after acute MI is clinically important. METHODS: Tissue Doppler echocardiography with SRI and Ce-MRI were performed in 47 consecutive patients with a first acute MI between days 2 and 6 and compared to 60 age-matched healthy volunteers. Peak myocardial velocities and peak myocardial deformation strain rates were measured. Location and size of the infarct zone was confirmed by Ce-MRI using the delayed enhancement technique with a 16-segment model. RESULTS: Contrast-enhanced MRI identified transmural infarction in 21 patients, non-transmural infarction in 15 (mean transmurality of infarct 72.3 +/- 10.6%), and another 11 patients with subendocardial infarction (<50% transmural extent of the left ventricular wall). Peak systolic strain rate (SRs) of the transmural infarction segments was significantly lower compared to normal myocardium or with non-transmural infarction segments (both p < 0.0005). A cutoff value of SRs >-0.59 s(-1) detected a transmural infarction with high sensitivity (90.9%) and high specificity (96.4%), and -0.98 s(-1) >SRs >-1.26 s(-1) distinguished subendocardial infarction from normal myocardium with a sensitivity of 81.3% and a specificity of 83.3%. CONCLUSIONS: Peak myocardial deformation by SRI can differentiate transmural from non-transmural MI, and it allows noninvasive determination of transmurality of the scar after MI and thereby the extent of non-viable myocardium.

Acute Disease↗
PubMed2005

Polyetheretherketone as a biomaterial for spinal applications.

Threaded lumbar interbody spinal fusion devices (TIBFD) made from titanium have been reported to be 90% effective for single-level lumbar interbody fusion, although radiographic determination of fusion has been intensely debated in the literature. Using blinded radiographic, biomechanic, histologic, and statistical measures, we evaluated a radiolucent polyetheretherketone (PEEK)-threaded interbody fusion device packed with autograft or rhBMP-2 on an absorbable collagen sponge in 13 sheep at 6 months. Radiographic fusion, increased spinal level biomechanical stiffness, and histologic fusion were demonstrated for the PEEK cages filled with autograft or rhBMP-2 on a collagen sponge. No device degradation or wear debris was observed. Only mild chronic inflammation consisting of a few macrophages was observed in peri-implant tissues. Based on these results, the polymeric biomaterial PEEK may be a useful biomaterial for interbody fusion cages due to the polymer's increased radiolucency and decreased stiffness.

Animals↗
PubMed2005

[Prevention of glucocorticoid-induced osteoporosis in patients with primary glomerulonephritis].

OBJECTIVE: To investigate the changes of bone metabolism in patients with primary glomerulonephritis who receive glucocorticoid (GC) treatment and to compare the therapeutic efficacy and security of alfacalcidol in prevention of glucocorticoid-induced osteoporosis (GIOP). METHODS: 89 patients with primary glomerulonephritis, aged 18 approximately 50, were randomly divided into 3 groups: Group A (n = 30) treated with alfacidol 1.0 microg/d plus calcium carbonate 750 mg Tid, Group B (n = 30) treated with alfacidol 0.5 microg/d plus calcium carbonate 750 mg Tid, and control group (n = 29) treated with calcium carbonate 750 mg Tid. The bone mineral density (BMD) at the lumbar spine and femoral neck was measured, and the serum levels of osteocalcin (OC), calcium, phosphorus, albumin (Alb), and creatine (Scr) were examined before and 3, 6, and 12 months after the treatment. RESULTS: The values of BMD at the lumbar spine and femoral neck before the treatment was not significantly different from those 3, 6, and 12 months after the treatment in Groups A and B (all P > 0.05) and there were no significant differences in the BMD values at different time points between Group A and Group B. In the control group the BMD values at the lumbar spine 3, 6, and 12 months after the beginning of experiment were significantly lower than that before the experiment and significantly lower than the corresponding values of Groups A and B (all P < 0.05), however, there was no significant difference in the BMD value at the femoral neck before and after the experiment in the control group. The serum OC 3, 6, and 12 months after were significantly lower than that before the experiment (all P < 0.05) in the control group. However, there was no significant difference in the value of serum OC before and 3, 6, and 12 months after the treatment in Groups A and B (all P > 0.05). CONCLUSION: Treatment of alfacidol 0.5 microg/d plus calcium carbonate helps preserve the BMD and prevent bone loss in the patients with primary glomerulonephritis.

Adolescent↗