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Integrins are a family of cell adhesion receptors that are involved in cell-matrix and cell-cell communications. They facilitate cell proliferation, migration, and survival. Using the Cre-Lox system, we deleted beta1 integrin on Tie2-positive (Tie2-cre beta1 Int (fl/fl)) vascular endothelial cells. Deletion of beta1 integrin on vascular endothelial cells results in embryonic lethality. Blood vessel defects are encountered in the Tie2-Cre beta1 Int (fl/fl) embryos at embryonic age (E9.5), and embryos die before reaching E10.5. The embryos exhibit growth retardation and both histological evaluation and PECAM-1 staining of E9.5 embryos revealed defects in angiogenic sprouting and vascular branching morphogenesis. Large and medium-size vessel formation is not affected in these embryos. Angiogenic defects were observed in several regions of the embryo and yolk sacs. These results indicate that beta1 integrin expression on vascular endothelial cells is crucial for embryonic angiogenesis but dispensable for vasculogenesis.  相似文献   
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Background  

Breast cancer cells with CD44+/CD24- cell surface marker expression profile are proposed as cancer stem cells (CSCs). Normal breast epithelial cells that are CD44+/CD24- express higher levels of stem/progenitor cell associated genes. We, amongst others, have shown that cancer cells that have undergone epithelial to mesenchymal transition (EMT) display the CD44+/CD24- phenotype. However, whether all genes that induce EMT confer the CD44+/CD24- phenotype is unknown. We hypothesized that only a subset of genes associated with EMT generates CD44+/CD24- cells.  相似文献   
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The binder sperm proteins (BSP) have damaging effects on the sperm cryopreservation. Greater concentrations of BSPs in seminal plasma remove more cholesterol and phospholipids from the sperm membrane, resulting in a destabilization that decreases sperm resistance to cold shock and freezing. The present study was conducted to clone, express recombinant BSP3 and find its localization in spermatozoa of Bubalus bubalis. The amplified buffalo BSP3 gene coded for 136 amino acids and the expressed recombinant protein showed a molecular weight of about 19.5 kDa. The hyper-immune serum raised against the recombinant BSP3 reacted specifically to a 19.5 kDa protein in the sperm cell lysate. Further, the Bioinformatics analysis predicted two fibronectin type 2 (FN-2) binding domains. The buffalo BSP3 showed changes in the amino acid sequence in both N-terminal and FN2 domains which might alter its binding properties. The protein has been localized to the acrosome and the middle piece of the spermatozoa by indirect immuno-fluorescence microscopy. Nevertheless, the antibodies against BSP3 can be used to measure its concentration in buffalo ejaculates and to effectively sequester excess BSP3 to prevent the early cryocapacitation.  相似文献   
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Black blood turbo spin echo (TSE) imaging of the right ventricle (RV) free wall is highly sensitive to cardiac motion, frequently resulting in nondiagnostic images. Temporal and spatial parameters of a black blood TSE pulse sequence were evaluated for visualization of the RV free wall. Seventy‐four patient studies were retrospectively evaluated for the effects of acquisition timing on image quality. Axial black blood TSE images were acquired on 10 healthy volunteers to assess the role of spatial misregistration on right ventricle visualization; increasing the double inversion recovery (DIR) slice thickness beyond 300% had no effect on image quality (P = 0.2). Thirty‐five patient studies were prospectively evaluated with inversion times (TIs) corresponding to the mid‐diastolic rest period and end‐systole based on visual analysis of a four chamber cine. When TIs were chosen to be within the patients' RV rest period, mean image quality score was significantly improved (2.3 vs 1.86; P < 0.001) and the number of clinically diagnostic images increased from 32% to 46%. Black blood TSE imaging of the RV free wall is highly sensitive to cardiac motion. Image quality can be improved by choosing TIs concordant with the rest period of the patient's RV that may occur at mid‐diastole or end‐systole. Magn Reson Med 61:307–314, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   
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The binder of sperm proteins (BSP) are secretary products of seminal vesicles. Secretions from the seminal vesicles contribute more to seminal plasma which determine the quality of the semen. The concentration of BSPs in seminal plasma has been negatively correlated with cryopreservation. An analysis of expression profile of seminal plasma proteins could be critical for better freezability of semen. Present study was carried out to assess the expression levels of major seminal plasma protein genes viz., BSP1, BSP3 and BSP5 from seminal vesicles of water buffalo using Real Time PCR. The study consisted of identification of a suitable reference gene in seminal vesicles followed by the expression analysis of major bovine seminal plasma protein (BSP) genes. The most stable reference gene among the three (glyceraldehyde 3-phosphate dehydrogenase, ribosomal protein S15a (RPS15a) and beta-actin), was found to be RPS15a and therefore, was used for normalization of target gene expression. Data analysis of major BSPs showed highest relative expression of BSP3 followed by BSP1 and BSP5. The ratio of relative expression of BSP1:BSP3:BSP5 was 10:18:1. The results from the study also showed an altered expression pattern of major BSP genes in buffalo seminal vesicles. Thus, it can be concluded that the altered expression of these genes at mRNA level would also be reflected at protein level in the seminal plasma. This could be one of the probable reasons for poor freezability of buffalo semen as compared to cattle and the finding helps in designing better cryopreservation strategies for buffalo semen.  相似文献   
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Background

The extent of left atrial (LA) baseline low-voltage areas (LVA-B), which may be a surrogate for fibrosis, is associated with recurrent atrial fibrillation (AF) after ablation. This study aimed to assess the relationship between the extent of LVA-B isolated by ablation (LVA-I) and AF recurrence.

Methods

The study cohort included 159 consecutive patients with drug-refractory AF who underwent an initial AF ablation with LA voltage mapping during sinus rhythm. The extent of LVA-B was quantified while excluding the pulmonary veins, LA appendage, and mitral valve area. LVA-I was quantified as the percentage of LVA-B encircled by pulmonary vein isolation. Surveillance and symptom-prompted electrocardiograms, Holter monitors, and event monitors were used to document atrial arrhythmia recurrence for a median follow-up of 712 days (1.95 years).

Results

Of 159 patients, 72% were men and 27% had persistent AF. The mean number of sampled bipolar voltage points was 119 ± 56. The mean LA surface area was 102.3 ± 37.3 cm2, and the mean LVA-B was 1.9 ± 3.8 cm2. The mean LVA-I was 51.05% ± 36.8% of LVA-B. In the multivariable Cox proportional hazards model adjusted for LA volume, CHA2DS2-VASc (Congestive Heart Failure, Hypertension, Age [≥ 75 years], Diabetes, Stroke/Transient Ischemic Attack, Vascular Disease, Age [65-74 years], Sex [Female] score), LVA-B, and AF type, LVA-I was inversely associated with recurrent atrial arrhythmia after the blanking period (hazard ratio, 0.42/percent LVA isolated; P = 0.037).

Conclusions

The extent of LVA-I is independently associated with freedom from atrial arrhythmias after AF ablation, supporting ongoing efforts to target low LA voltage areas and other fibrosis indicators to improve ablation outcomes.  相似文献   
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