Search

Avoidance of red blood cell (RBC) transfusions in patients awaiting heart transplantation (HTx) has been suggested to minimize the risk of allosensitization. Although recent studies have suggested that an immature immune system in younger HTx recipients may reduce risks associated with RBC transfusion, the role of age in moderating the influence of transfusion on HTx outcomes remains unclear. We used available data from a national transplant registry to explore whether the association between pre-transplant transfusions and outcomes of pediatric HTx varies by patient age. De-identified data were obtained from the United Network for Organ Sharing registry, including first-time recipients of isolated HTx performed at age 0-17 years in 1995-2015. The primary exposure was receiving blood transfusions within 2 weeks prior to HTx. Patient survival after HTx was evaluated using multivariable Cox proportional hazards, where age at transplant was interacted with exposure to pre-transplant transfusion. Age-specific hazard ratios (HRs) of pre-transplant transfusion were plotted across ages at transplant. There were 4883 patients meeting inclusion criteria, of whom 1258 died during follow-up (mean follow-up duration 6 ± 5 years). Patients receiving pre-transplant transfusions were distinguished by younger age, higher prevalence of prior cardiac surgery, greater likelihood of being in the intensive care unit, and greater use of left ventricular assist device bridge to transplant. In multivariable analysis, pre-transplant transfusions were associated with increased mortality hazard among infants

The Parkinson's disease questionnaire (PDQ-39) is a well-validated British scale for the assessment of health-related quality of life (HQoL) in Parkinson's disease (PD). The PDQ-39 has been translated into Greek and it was applied to 119 Greek PD patients. These patients were classified in stages according to the Hoehn and Yahr (HY) scale and their motor disability was assessed by means of the Unified Parkinson's disease rating scale (UPDRS) as well as the Schwab and England activities of daily living scale (ADL). The Beck depression inventory (BDI) was applied for the evaluation of depression. The translated version of PDQ-39, designated PDQ-39GrV, was validated as follows: (1) Cronbach's α coefficient and item — total Spearman's rank — order correlations were calculated in order to estimate the internal consistency of PDQ-39GrV scales. (2) Validity of the PDQ-39GrV was examined in terms of agreement with the clinical assessment parameters (stage, UPDRS, ADL and BDI scores). (3) Sixty one PD patients were re-evaluated 3–7days later in order to check test-retest reliability. The results showed the following: (1) The PDQ-39GrV demonstrated very good internal consistency (α: 0.71–0.94). Item — total correlations were statistically significant (r: 0.52–0.93). Test-retest measurements correlated significantly (p = 0.001). (2) Clinically obtained motor parameters correlated well with PDQ-39GrV scales influenced by physical aspects of the disease, while emotionally and socially influenced ones correlated with depression. Our findings indicate that PDQ-39 GrV is a reliable, easy to administer scale for the assessment of HQoL in Greek PD patients.

An in vitro whole blood reperfusion model was employed to quantify: (a) initial rates of lysis of mural platelet deposits from flowing blood onto fibrin-coated surfaces and (b) plasmin-mediated consumption of plasma plasminogen and fibrinogen, by recombinant tissue-type plasminogen activator (rt-PA) and two t-PA variants, KHRR 296–299 AAAA (K-tPA) and T103N, N117Q, KHRR 296–299 AAAA (TNK-tPA), at wall shear rates of either 500 or 1000 s−1. K- and TNK-tPA are more fibrin-specific than rt-PA, and are also resistant to inactivation by plasminogen activator inhibitor−1 (PAI−1). At 500 s−1, no agent showed significant lysis of mural platelet deposits on fibrin, even at concentrations as high as 10 μ g/ml of blood. At 1000 s−1, each agent demonstrated a dose-dependent lysis of mural platelet deposits, due to plasmin-mediated lysis of the fibrin substrate (fibrinolysis). The local concentration of thrombolytic agents close to the fibrin-coated surface is probably higher than the concentration of released PAI−1 from the adherent and activated platelets. Hence, the initial rates of lysis achieved by K- and TNK-tPA were not significantly different from that by rt-PA, when each agent was tested at either 1 or 10 μ g/ml of blood. However, TNK-tPA, at 1 μ g/ml,> caused the most extensive lysis at the end of the 50 min reperfusion period (50% vs 29% and 17% by rt-PA and K-tPA, respectively). K- and TNK-tPA, at concentrations as high as 10 μ g/ml of blood, caused plasminogen activation that was controlled by the natural plasmin inhibitors, and, thus, no proteolytic degradation of plasma fibrinogen (fibrinogenolysis). On the contrary, rt-PA at 1 μ g/ml revealed slight fibrinogenolysis that became extensive at 10 μ g/ml. This study demonstrates the potential use of an in vitro model, that mimics the in vivo hemodynamic environment, in evaluating the performance of thrombolytic agents. The data suggest that: (a) adequate flow must accompany fibrinolysis for successful embolization, and (b) the TNK variant may lyse annular thrombi after recanalization, at least as efficiently as rt-PA does, while causing lesser defect of systemic hemostasis. © 1998 Biomedical Engineering Society. PAC98: 8745Hw, 8790+y, 8380Lz, 8715Kg

Two adjective pairs in comparative form, more-less and taller-shorter, were tested with moderately mentally retarded (MR) and nonretarded children (NR) matched on verbal mental age (MA) and socioeconomic status (SES) in a “show” and an “act-out” experimental condition. The data indicated that all the main effects, the group, the experimental condition, and the unmarked-marked relational terms were significant and so were the interactions of the Group × Experimental Conditions, Group × Unmarked Versus Marked Relational Terms, and Group × Experimental Conditions and Unmarked Versus Marked Relational Terms. A logistic regression analysis (LRA) showed that the relational term shorter in the act-out condition best predicted classification membership for the subjects in either group, suggesting that the MR children were less able to self-regulate behavior. The error types, however, mainly observed in the act-out experimental condition were the same from a semantic point of view in either group. The effect of the unmarked versus marked distinction cannot be considered independent of the experimental conditions applied.

The effect of flow-induced shear stress on membrane K+ permeability was investigated by measuring86Rb+ efflux in cultured calf pulmonary artery endothelial cells. Cells were subjected to step changes in shear stress from 1 dyn/cm2 to 2.4, 4.8, or 10 dyn/cm2 in a parallel-plate flow chamber. Increasing shear stress produced a graded, transient increase in86Rb+ efflux which peaked within 1 min and subsequently declined rapidly toward pre-stimulus levels. Upon returning shear stress to 1 dyn/cm2,86Rb+ efflux initially decreased, but returned slowly to basal values. In contrast, application of bradykinin at a constant shear stress of 1 dyn/cm2 produced a transient increase in86Rb+ efflux that was followed by a sustained elevated phase during which time efflux gradually returned to pre-stimulus levels. In order to exclude the possibility that the transient increase in86Rb+ efflux with shear stress simply reflects a flow-dependent change in the washout of radiotracer, the transient convection-diffusion equation was solved using finite element simulation. When the flux of86Rb+ from the cell monolayer was assumed to be constant with time, the mathematical model predicted an increase in efflux rate coefficients upon step increases in flow that were only 7–19% of that observed experimentally. The numerical predictions correlated well with the experimentally obtained peaks when the flux of86Rb+ from the cell monolayer was simultaneously increased with flow to a new steady value. These simulations however, could not predict the transient nature of the response to increased shear stress. The results from the computer modeling suggest that the transient increase in86Rb+ efflux does not reflect a washout phenomenon and supports the hypothesis that shear stress produces a graded, transient increase in the K+ permeability of vascular endothelial cells.