Objective To evaluate Left ventricular(LV) diastolic function in essential hypertension by conventional pulse-wave Doppler echocardiography (cPWD) and Doppler tissue imaging (DTI) and compare the two modalities. Methods Two hundred patients with essential hypertension were classified as NLVH subgroup (n = 160) and LVH subgroup (n =40) based on left ventricular mass index (LVMI) with one hundred and sixty health subjects as control group. The mitral valve flow pattern (MVFP) was obtained.Early diastolic (E) and late velocities (A) were measured and E/A was calculated. DTI was used to obtain the left ventricular lateral wall early diastolic mitral annulus velocity (Em) and E/Em was calculated.Results Essential hypertension patients had LV diastolic dysfunction both by cPWD (higher E and lower E/A ratio) and DTI (lower Em and higher E/Em ratio) compared with healthy subjects [E:(0. 88 ±0. 18)cm/s vs (0. 76 ±0. 19) cm/s;E/A ratio:0. 86 ±0. 28 vs 1.02 ±0. 38;Em: (9. 4 ±2. 8)cm/s vs (11. 9 ±3. 8)cm/s;E/Em ratio;7. 9 ± 2. 7 vs 6. 0 ± 1. 8: with all P value ＜0.01]. Em was significantly reduced and E/Em was significantly elevated in LVH subgroup than NLVH subgroup [Em; (7.7 ±2. 6) cm/s vs (9. 9 ± 2. 8) cm/s, E/Em: 9. 6 ± 3. 6 vs 7. 4 ± 2. 4, P ＜ 0. 05]. No significant difference was found in A and E/A between these two subgroups [(0. 90 ± 0. 22) cm/s vs (0. 87 ± 0. 17) cm/s; 0. 80 ± 0. 34 vs 0.88 ±0.28, P ＞ 0.05]. Conclusions cPWD and DTI both had implications to detect diastolic dysfunction in non-hypertrophic stage hypertension. Em、E/Em could be more sensitive and precise to reflect the impairment of diastolic function in the progress of hypertension.

Objective To develop specific targeted magnetic biomarkers which can selectively mark the senile plaques in Alzheimer' s disease (AD) and verify its feasibility and validity.Methods Aβ1-40 peptide and Tat-PTD ( Tat-protein transduction domain) was binded with dextran-coated ultrasmall superparamagnetic iron oxide ( USPIO) particles.Visualization of plaques in vivo in Alzheimer transgenic mice was investigated at 7.0 Tesla using T2 sequences after intravenous administration of the targeted nanoiron contrast agent and verified by histological staining.Results The targeted nano-iron contrast agent could enter the cultured neural stem cells,and was able to accelerate T2 relaxation rates of water protons in the cells and negatively reinforce the T2 signal intensity in the labeled cells.Plaques were specifically detected in vivo by magnetic resonance imaging ( MRI) and correlated well with histological staining after injection of nano-iron contrast agent into the APP/PS1 mice.Conclusion The targeted nano-iron contrast agent has the ability of selectively labeling the senile plaques in AD brain tissues in vivo,which might enable the early detection of plaques by MRI and can be further applied in the studies of early diagnosis of AD.

OBJECTIVETo investigate the effect of a new biomaterial combining calcium citrate and recombinant human bone morphogenetic protein-2 (rhBMP-2) on bone regeneration in a bone defect rabbit model.

METHODSTotally 30 male New Zealand white rabbits were randomly and equally divided into calcium citrate-rhBMP-2 (CC-rhBMP-2) group and rhBMP-2 only group. Two 10 mm-long and 5 mm-deep bone defects were respectively created in the left and right femoral condyles of the rabbits. Subsequently 5 pellets of calcium citrate (10 mg) combined with rhBMP-2 (2 mg) or rhBMP-2 alone were implanted into the bone defects and compressed with cotton swab. Bone granules were obtained at 2, 4 and 6 weeks after procedure and received histological analysis. LSD t-test and a subsequent t-test were adopted for statistical analysis.

RESULTSHistomorphometric analysis revealed newly formed bones, and calcium citrate has been absorbed in the treatment group. The percent of newly formed bone area in femoral condyle in control group and CC-rhBMP-2 group was respectively 31.73%+/-1.26% vs 48.21%+/-2.37% at 2 weeks; 43.40%+/-1.65% vs 57.32%+/-1.47% at 4 weeks, and 51.32%+/-7.80% vs 66.74%+/-4.05% at 6 weeks (P less than 0.05 for all). At 2 weeks, mature cancellous bone was observed to be already formed in the treatment group.

CONCLUSIONFrom this study, it can be concluded that calcium citrate combined with rhBMP-2 signifcantly enhances bone regeneration in bone defects. This synthetic gelatin matrix stimulates formation of new bone and bone marrow in the defect areas by releasing calcium ions.

Animals ; Biocompatible Materials ; Bone Regeneration ; Calcium Citrate ; Humans ; Osteogenesis

OBJECTIVETo investigate the relationship between the mRNA expression levels of p53-mediating DNA damage and repair genes in the peripheral blood lymphocytes of workers and their exposures to benzene in their working environment.

METHODSThe mRNA expression levels of p53 and related genes were determined by SYBR Green I chimeric fluorescence quantitative real-time RT-PCR analysis in peripheral blood lymphocytes of 72 workers, who were classified into group A (46 direct exposure to benzene) and group B (26 indirect exposure to benzene) based on their positions, and 29 controls. The differences of gene expression levels were analyzed by software REST 2005. Meanwhile, the peripheral blood leukocytes, hemoglobin and platelet of workers and controls were counted. Benzene content was measured in the samples of toluene, used as raw material, and spraying agents and benzene, toluene and xylene concentrations in the air of workplaces were monitored.

RESULTSThere were no significant differences in the mRNA expression levels of p53, Ku80, Ape1 and Mdm-2 between group A or group B and control group (P > 0.05). The expression up-regulation of p21 mRNA was found, but without significant difference (P > 0.05). However, the mRNA expression levels of Rad51, Bcl-2, Bax, Xpa and Xpc in group A and Rad51 in group B were downregulated significantly (P < 0.05 or P < 0.01). Moreover, both the counts of white blood cell, hemoglobin and platelet in group A were (4.93 +/- 1.27) x 10(9)/L, (123.97 +/- 11.80) g/L and (124.02 +/- 41.22) x 10(9)/L respectively and platelet in group B (135.80 +/- 39.44) x 10(9)/L were significantly lower than in control group (P < 0.05 or P < 0.01).

CONCLUSIONThe mRNA expression levels of some p53-mediating DNA damage and repair genes are downregulated in the workers chronically exposed to low benzene concentration. The working environment impacts on health of group A workers are greater than the ones of group B.

Adult ; Benzene ; adverse effects ; DNA Damage ; DNA Repair ; Female ; Humans ; Lymphocytes ; drug effects ; metabolism ; Male ; Occupational Exposure ; adverse effects ; RNA, Messenger ; genetics ; Tumor Suppressor Protein p53 ; genetics ; metabolism ; Young Adult