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101.
Studies on the role played by attachment attitudes among late adolescents who show Problematic Internet Use (PIU) are still lacking. Three self-report measures concerning attachment attitudes, childhood experiences of abuse, and Internet addiction were administered to 310 students (49 % males) aged 18–19 attending the last year of high school. Students who screened positive for PIU were more likely to be male and to have suffered childhood experiences of physical and sexual abuse; they also scored higher than the other participants on scales assessing anxious and avoidant attachment attitudes. A logistic regression showed that the classification of participants in the PIU group was predicted by male gender, having suffered from physical and sexual abuse in childhood, and preoccupation with relationships. Keeping constant the effects of gender and childhood experiences of abuse in the equation model, increasing values of preoccupation with relationships were reflected by an exponential growth in the probability curve for PIU classification. Findings of the study support the hypothesis that insecure attachment attitudes (particularly the preoccupation with relationships) are involved in the development of PIU among late adolescents.  相似文献   
102.
Although the causes of dyslexia are still debated, all researchers agree that the main challenge is to find ways that allow a child with dyslexia to read more words in less time, because reading more is undisputedly the most efficient intervention for dyslexia. Sophisticated training programs exist, but they typically target the component skills of reading, such as phonological awareness. After the component skills have improved, the main challenge remains (that is, reading deficits must be treated by reading more--a vicious circle for a dyslexic child). Here, we show that a simple manipulation of letter spacing substantially improved text reading performance on the fly (without any training) in a large, unselected sample of Italian and French dyslexic children. Extra-large letter spacing helps reading, because dyslexics are abnormally affected by crowding, a perceptual phenomenon with detrimental effects on letter recognition that is modulated by the spacing between letters. Extra-large letter spacing may help to break the vicious circle by rendering the reading material more easily accessible.  相似文献   
103.
We introduce a new approach to improve structural and dynamical determination of large metalloproteins using solid-state nuclear magnetic resonance (NMR) with (1)H detection under ultrafast magic angle spinning (MAS). The approach is based on the rapid and sensitive acquisition of an extensive set of (15)N and (13)C nuclear relaxation rates. The system on which we demonstrate these methods is the enzyme Cu, Zn superoxide dismutase (SOD), which coordinates a Cu ion available either in Cu(+) (diamagnetic) or Cu(2+) (paramagnetic) form. Paramagnetic relaxation enhancements are obtained from the difference in rates measured in the two forms and are employed as structural constraints for the determination of the protein structure. When added to (1)H-(1)H distance restraints, they are shown to yield a twofold improvement of the precision of the structure. Site-specific order parameters and timescales of motion are obtained by a gaussian axial fluctuation (GAF) analysis of the relaxation rates of the diamagnetic molecule, and interpreted in relation to backbone structure and metal binding. Timescales for motion are found to be in the range of the overall correlation time in solution, where internal motions characterized here would not be observable.  相似文献   
104.

Background:

This prospective study investigated the association between preprocedural biomarker levels and incident major adverse cardiac events (MACE) in complex patients undergoing percutaneous coronary intervention (PCI) with sirolimus‐eluting stenting.

Hypothesis:

Lipoprotein(a) (Lp[a]), interleukin‐10 (IL‐10), and high‐sensitivity C‐reactive protein (CRP) have long‐term prognostic value in patients undergoing PCI.

Methods:

Between April 2002 and February 2003, 161 patients were included in the study. Blood was drawn before the procedure, and biomarkers were measured. Patients were followed‐up for MACE (death, nonfatal myocardial infarction, and repeat revascularization). Cox proportional hazard models were used to determine risk of MACE for tertiles of biomarkers. Both 1‐year and long‐term follow‐up (median, 6 years; maximum, 8 years) were evaluated.

Results:

Mean age was 59 years, and 68% were men. During long‐term follow‐up, 72 MACE occurred (overall crude cumulative incidence: 45% [95% confidence interval (CI): 37%‐52%]). Lp(a) was associated with a higher 1‐year risk of MACE, with an adjusted hazard ratio (HR) of 3.1 (95% CI: 1.1‐8.6) for the highest vs the lowest tertile. This association weakened and lost significance with long‐term follow‐up. IL‐10 showed a tendency toward an association with MACE. The 1‐year HR was 2.1 (95% CI: 0.92‐5.0). Long‐term follow‐up rendered a similar result. The association of CRP with MACE did not reach statistical significance at 1‐year follow‐up. However, CRP was associated with long‐term risk of MACE, with an HR of 1.9 (95% CI: 1.0‐3.5).

Conclusions:

In this prospective study, preprocedural Lp(a) level was associated with short‐term prognosis after PCI. The preprocedural CRP level was associated with long‐term prognosis after PCI. Clin. Cardiol. 2012 DOI: 10.1002/clc.21988 The authors have no funding, financial relationships, or conflicts of interest to disclose.  相似文献   
105.
Right ventricular (RV) failure (RVF) is the main cause of death in patients with pulmonary artery hypertension (PAH). Sildenafil, a phosphodiesterase type 5 inhibitor, was approved recently for treatment of PAH patients. However, the mechanisms underlying RV contractile malfunction and the benefits of sildenafil on RV function are not well understood. We aimed to investigate the following: (1) the ultrastructural and excitation-contraction coupling alterations underlying PAH-induced RVF; (2) whether the ultrastructural changes are reversible; and (3) the mechanisms underlying the therapeutic benefits of sildenafil in PAH-RVF. We used a single injection of monocrotaline in Wistar rats to induce pulmonary vascular proliferation, which led to PAH and RVF. RV myocytes displayed severe transverse (T)-tubule loss and disorganization, as well as blunted and dys-synchronous sarcoplasmic reticulum Ca(2+) release. Sildenafil prevented and reversed the monocrotaline-induced PAH and LV filling impairment. Early intervention with sildenafil prevented RV hypertrophy and the development of RVF, T-tubule remodeling, and Ca(2+) handling dysfunction. Although late treatment with sildenafil did not reverse RV hypertrophy in animals with established RVF, RV systolic function was improved. Furthermore, late intervention partially reversed both the impairment of myocyte T-tubule integrity and Ca(2+) handling protein and sarcoplasmic reticulum Ca(2+) release function in monocrotaline-treated rats. In conclusion, PAH-induced increase in RV afterload causes severe T-tubule remodeling and Ca(2+) handling dysfunction in RV myocytes, leading to RV contractile failure. Sildenafil prevents and partially reverses ultrastructural, molecular, and functional remodeling of failing RV myocytes. Reversal of pathological T-tubule remodeling, although incomplete, is achievable without the regression of RV hypertrophy.  相似文献   
106.

Background

Takotsubo cardiomyopathy (TC) usually is not recognized until heart catheterization reveals typical wall motion abnormalities in the absence of significant coronary artery disease. It was our aim to identify TC by its unique cardiac biomarker profile at an early stage and, preferably, with non-invasive procedures only.

Methods

Ratios of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and myoglobin, NT-proBNP and troponin T (TnT), NT-proBNP and creatinekinase-MB (CK-MB) were compared in patients with TC (n = 39), patients with ST-elevation myocardial infarction (STEMI, n = 48) and patients with non-ST-elevation myocardial infarction (NSTEMI, n = 34). Biomarkers were recorded serially at admission and at the three consecutive days. Optimal cut-off values to distinguish TC from STEMI and NSTEMI were calculated with receiver operator characteristic (ROC) curves.

Results

At admission a NT-proBNP (ng/l)/myoglobin (μg/l) ratio of 3.8, distinguished TC from STEMI (sensitivity: 89%, specificity: 90%), while a NT-proBNP (ng/l)/myoglobin (μg/l) ratio of 14 separated well between TC and NSTEMI (sensitivity: 65%, specificity: 90%). Best differentiation of TC and ACS was possible with the ratio of peak levels of NT-proBNP (ng/l)/TnT (μg/l). A cut-off value of NT-proBNP (ng/l)/TnT (μg/l) ratio of 2889, distinguished TC from STEMI (sensitivity: 91%, specificity: 95%), while a NT-proBNP (ng/l)/TnT (μg/l) ratio of 5000 separated well between TC and NSTEMI (sensitivity: 83%, specificity: 95%).

Conclusions

TC goes along with a singular cardiac biomarker profile, which might be useful to identify patients with TC among patients presenting with acute coronary syndromes (ACS).  相似文献   
107.
Asthma is a phenotypically heterogeneous disorder of multifactorial origins that affects 300 million people suffering from asthma and more than 250,000 asthma-related deaths each year. Although treatment for asthma has improved, its prevalence continues to increase, particularly in low and middle income countries, or in some ethnic groups in which prevalence was previously low. Observed spatio-temporal variations in the increased prevalence of asthma depend on exposure to environmental factors. Recently, several arguments are also in favor of the involvement of host susceptibility and stress in the observed increase of asthma prevalence. Further?investigations are warranted to better understand mechanisms underlying asthma increase or stagnation.  相似文献   
108.

Background

The interaction of adenosine diphosphate with its P2Y1 and P2Y12 receptors on platelets is important for platelet function. However, nothing is known about adenosine diphosphate and its function in human megakaryocytes.

Design and Methods

We studied the role of adenosine diphosphate and P2Y receptors on proplatelet formation by human megakaryocytes in culture.

Results

Megakaryocytes expressed all the known eight subtypes of P2Y receptors, and constitutively released adenosine diphosphate. Proplatelet formation was inhibited by the adenosine diphosphate scavengers apyrase and CP/CPK by 60-70% and by the P2Y12 inhibitors cangrelor and 2-MeSAMP by 50-60%, but was not inhibited by the P2Y1 inhibitor MRS 2179. However, the active metabolites of the anti-P2Y12 drugs, clopidogrel and prasugrel, did not inhibit proplatelet formation. Since cangrelor and 2-MeSAMP also interact with P2Y13, we hypothesized that P2Y13, rather than P2Y12 is involved in adenosine diphosphate-regulated proplatelet formation. The specific P2Y13 inhibitor MRS 2211 inhibited proplatelet formation in a concentration-dependent manner. Megakaryocytes from a patient with severe congenital P2Y12 deficiency showed normal proplatelet formation, which was inhibited by apyrase, cangrelor or MRS 2211 by 50-60%. The platelet count of patients with congenital delta-storage pool deficiency, who lack secretable adenosine diphosphate, was significantly lower than that of patients with other platelet function disorders, confirming the important role of secretable adenosine diphosphate in platelet formation.

Conclusions

This is the first demonstration that adenosine diphosphate released by megakaryocytes regulates their function by interacting with P2Y13. The clinical relevance of this not previously described physiological role of adenosine diphosphate and P2Y13 requires further exploration.Key words: ADP, proplatelet formation, P2Y13 receptor  相似文献   
109.
Long‐term studies of Charcot‐Marie‐Tooth (CMT) disease across the entire lifespan require stable endpoints that measure the same underlying construct (e.g., disability). The aim of this study was to assess the relationship between the CMT Pediatric Scale (CMTPedS) and the adult CMT Neuropathy Score (CMTNSv2) in 203 children, adolescents, and young adults with CMT. There was a moderate curvilinear correlation between the CMTPedS and the CMTNSv2 (Spearman's rho ρ = 0.716, p < 0.0001), although there appears to be a floor effect of the CMTNSv2 in patients with a milder CMT phenotype. Univariate analyses indicate that the relationship between the CMTPedS and CMTNSv2 scores improves with worsening disease severity and advancing age. Although one universal scale throughout life would be ideal, our data supports the transition from the CMTPedS in childhood to the CMTNSv2 in adulthood as a continuum of measuring lifelong disability in patients with CMT.  相似文献   
110.
The treatment of elderly patients with coronary artery disease (CAD) is challenging because this population is complex and greatly expanding. Drug-eluting stents (DES) generally improve the outcome in high-risk cases. We evaluated the clinical impact of different first-generation DES, i.e., sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES), in this context. A prospective, nonrandomized, single-center, allcomers registry consecutively enrolling all patients aged ≥75 years eligible for percutaneous coronary intervention (PCI) with DES was carried out. Only one type of DES was implanted per protocol for each patient. Two groups were identified according to the type of implanted stent, i.e., SES and PES. The primary end point encompassed major adverse cardiac events (MACE), including death, myocardial infarction, and target lesion revascularization (TLR). The secondary end point encompassed the rate of definite/probable stent thrombosis and target vessel revascularization (TVR). From June 2004 to May 2008, 151 patients were enrolled. Among them, 112 (74.2%) received SES and 39 (25.8%) received PES. Baseline clinical characteristics were similar, while few angiographic features (ostial location, stent diameter, proximal reference vessel diameter) showed minor differences. At the median follow-up of 22.6 months, primary and secondary end points did not significantly differ in terms of MACE (SES 12.5% vs PES 20.5%, P = 0.3), death (SES 5.4% vs PES 7.7%, P = 0.7), myocardial infarction (SES 4.5% vs PES 10.3%, P = 0.2), TLR (SES 2.7% vs PES 2.6%, P = 1.0), stent thrombosis (SES 1.8% vs PES 5.1%, P = 0.3), and TVR (SES 1.8% vs PES 0%, P = 0.6). In this real-world population of elderly patients treated by DES–PCI for CAD, the overall efficacy and safety have been excellent in both DES, and the choice between SES and PES did not influence the clinical outcome.  相似文献   
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