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Abstract

A class of very potent nucleoside transport inhibitors is present in two molecular forms around physiological pH. We investigated whether the monoprotonated or the unionized species of these molecules binds to this camer protein with higher affinity.  相似文献   
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The study investigates the effects of the 11+ and HarmoKnee injury prevention programmes on knee strength in male soccer players. Under-21-year-old players (n=36) were divided equally into: the 11+, HarmoKnee and control groups. The programmes were performed for 24 sessions (20-25 min each). The hamstrings and quadriceps strength were measured bilaterally at 60°·s-1, 180°·s-1 and 300°·s-1. The concentric quadriceps peak torque (PT) of the 11+ increased by 27.7% at 300°·s-1 in the dominant leg (p<0.05). The concentric quadriceps PT of HarmoKnee increased by 36.6%, 36.2% and 28% in the dominant leg, and by 31.3%, 31.7% and 20.05% at 60°·s-1, 180°·s-1 and 300°·s-1 in the non-dominant leg respectively. In the 11+ group the concentric hamstring PT increased by 22%, 21.4% and 22.1% at 60°·s-1, 180°·s-1 and 300°·s-1, respectively in the dominant leg, and by 22.3%, and 15.7% at 60°·s-1 and 180°·s-1, in the non-dominant leg. In the HarmoKnee group the hamstrings in the dominant leg showed an increase in PT by 32.5%, 31.3% and 14.3% at 60°·s-1, 180°·s-1 and 300°·s-1, and in the non-dominant leg hamstrings PT increased by 21.1% and 19.3% at 60°·s-1 and 180°·s-1 respectively. The concentric hamstrings strength was significantly different between the 11+ and control groups in the dominant (p=0.01) and non-dominant legs (p=0.02). The HarmoKnee programme enhanced the concentric strength of quadriceps. The 11+ and HarmoKnee programmes are useful warm-up protocols for improving concentric hamstring strength in young professional male soccer players. The 11+ programme is more advantageous for its greater concentric hamstring strength improvement compared to the HarmoKnee programme.  相似文献   
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This study focuses on the transient and dynamic activation of intracellular signal transduction following different protocols of depolarization. During chronic depolarization, phosphorylation of extracellular signal-regulated kinases (ERKs) was observed to peak and subsequently fall to low levels within 10 min of depolarization. Short periods of depolarization, from 1 to 5 min in duration, also led to phosphorylation of ERK, and the rate of ERK dephosphorylation was not affected by the duration of depolarization. Phosphorylation of the cyclic AMP response element binding protein (CREB) also peaked as a result of chronic depolarization but decreased to intermediate levels that were maintained for more than 1 h. Pulsatile depolarization was explored as a means to circumvent the deactivation of intracellular signaling activity during chronic depolarization. Both ERK and CREB were rephosphorylated by a second period of depolarization that followed a recovery period of 10 min or more. The effects of the durations of depolarization and interpulse recovery on reactivation of ERK and CREB were characterized. Measurements of free cytoplasmic Ca(2+) confirmed the transient rise in the intracellular calcium concentration ([Ca(2+)](i)) during chronic depolarization and the pulsatile increase in [Ca(2+)](i) that can be achieved with short periods of depolarization. This study characterizes the dynamic activities of signal transduction following depolarization. Electrical stimulation of neurons induces many cellular changes that unfold over time, and the influx of Ca(2+) ions that mediate these events is transient. This study suggests that pulsatile activity may be a means of maintaining signaling activity over long periods of time.  相似文献   
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Introduction  

Nucleus pulposus (NP) cells have a phenotype similar to articular cartilage (AC) cells. However, the matrix of the NP is clearly different to that of AC suggesting that specific cell phenotypes exist. The aim of this study was to identify novel genes that could be used to distinguish bovine NP cells from AC and annulus fibrosus (AF) cells, and to further determine their expression in normal and degenerate human intervertebral disc (IVD) cells.  相似文献   
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MicroRNA-181a binds to the 3′ untranslated region of messenger RNA (mRNA) for renin, a rate-limiting enzyme of the renin-angiotensin system. Our objective was to determine whether this molecular interaction translates into a clinically meaningful effect on blood pressure and whether circulating miR-181a is a measurable proxy of blood pressure. In 200 human kidneys from the TRANScriptome of renaL humAn TissuE (TRANSLATE) study, renal miR-181a was the sole negative predictor of renin mRNA and a strong correlate of circulating miR-181a. Elevated miR-181a levels correlated positively with systolic and diastolic blood pressure in TRANSLATE, and this association was independent of circulating renin. The association between serum miR-181a and systolic blood pressure was replicated in 199 subjects from the Genetic Regulation of Arterial Pressure of Humans In the Community (GRAPHIC) study. Renal immunohistochemistry and in situ hybridization showed that colocalization of miR-181a and renin was most prominent in collecting ducts where renin is not released into the systemic circulation. Analysis of 69 human kidneys characterized by RNA sequencing revealed that miR-181a was associated with downregulation of four mitochondrial pathways and upregulation of 41 signaling cascades of adaptive immunity and inflammation. We conclude that renal miR-181a has pleiotropic effects on pathways relevant to blood pressure regulation and that circulating levels of miR-181a are both a measurable proxy of renal miR-181a expression and a novel biochemical correlate of blood pressure.  相似文献   
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Background

During liver development, intrahepatic bile ducts are thought to arise by a unique asymmetric mode of cholangiocyte tubulogenesis characterized by a series of remodeling stages. Moreover, in liver diseases, cells lining the Canals of Hering can proliferate and generate new hepatic tissue. The aim of this study was to develop protocols for three-dimensional visualization of protein expression, hepatic portal structures and human hepatic cholangiocyte tubulogenesis.

Results

Protocols were developed to digitally visualize portal vessel branching and protein expression of hepatic cell lineage and extracellular matrix deposition markers in three dimensions. Samples from human prenatal livers ranging from 7 weeks + 2 days to 15½ weeks post conception as well as adult normal and acetaminophen intoxicated liver were used. The markers included cytokeratins (CK) 7 and 19, the epithelial cell adhesion molecule (EpCAM), hepatocyte paraffin 1 (HepPar1), sex determining region Y (SRY)-box 9 (SOX9), laminin, nestin, and aquaporin 1 (AQP1). Digital three-dimensional reconstructions using CK19 as a single marker protein disclosed a fine network of CK19 positive cells in the biliary tree in normal liver and in the extensive ductular reactions originating from intrahepatic bile ducts and branching into the parenchyma of the acetaminophen intoxicated liver. In the developing human liver, three-dimensional reconstructions using multiple marker proteins confirmed that the human intrahepatic biliary tree forms through several developmental stages involving an initial transition of primitive hepatocytes into cholangiocytes shaping the ductal plate followed by a process of maturation and remodeling where the intrahepatic biliary tree develops through an asymmetrical form of cholangiocyte tubulogenesis.

Conclusions

The developed protocols provide a novel and sophisticated three-dimensional visualization of vessels and protein expression in human liver during development and disease.  相似文献   
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