Patient perception and provider assessment of severity of heart failure as predictors of hospitalization

OBJECTIVE: To assess the agreement between 2 methods of assigning New York Heart Association (NYHA) functional class to patients with chronic heart failure (CHF): deriving NYHA class from self-report interview data versus clinician assignment. To then determine the ability of each method to predict all-cause hospitalization. METHODS: Adults with CHF > or = 50 years old from an urban health system in Indianapolis, Indiana, were administered the Kansas City Cardiomyopathy Questionnaire (a validated CHF symptom questionnaire) at baseline. Patient self-reported functional data were then used to derive NYHA class. Clinical providers who were blinded to patients' questionnaire data independently assessed NYHA functional class. We used a weighted kappa statistic to evaluate the agreement between the NYHA class from patient-derived and that from provider-assigned methods. We then assessed the ability of patient and provider NYHA to predict time to hospitalization using Cox proportional hazards models. RESULTS: Of 156 patients with complete 6-month follow-up (mean age 63 years +/- 9 SD, 53% African American, and 68% women), the correlation coefficient was 0.43 between the patient-derived and provider-assigned NYHA methods. The weighted kappa statistic was 0.278, and the 95% confidence interval was 0.18 to 0.37, indicating only slight agreement. Patients classified themselves in worse categories than did their providers. Provider-assigned NYHA was a better predictor of hospitalization (P = .06). CONCLUSIONS: There is only slight agreement between patient-derived and clinician-assigned NYHA functional class. A different approach with patients may be needed if providers hope to use patients' reports to identify those at risk for hospitalization.     

Recovery of Palladium(II) and Platinum(IV) in Novel Extraction Systems

Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the metal ions to the organic phase. As the best extractant among the investigated ones, D3EI-PrCl (with straight alkyl chain at substituent) can be pointed out, however, problems with effective stripping or phase disengagement after stripping should be indicated as a drawback of the organic phases used. Further investigation should focus on the improvement of the organic phase properties (e.g., increase in hydrophobicity of the extractants and addition of an organic phase modifier) towards stripping efficiency.     

The effect of response-delay on estimating reachability

The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.     

Stress-induced wall motion abnormalities with low-dose dobutamine infusion indicate the presence of severe disease and vulnerable myocardium

Background: Patients with left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) may develop stress-induced wall motion abnormalities (SWMA) with low-dose (10 μg/kg/min) dobutamine infusion. The clinical significance of low-dose SWMA is unknown. Objective: We investigated the clinical, hemodynamic and angiographic correlates of low-dose SWMA in patients with chronic ischemic LV systolic dysfunction. Methods: Seventy patients with chronic ischemic LV systolic dysfunction who had dobutamine stress echocardiography were studied. Clinical, hemodynamic, and angiographic parameters at rest and low-dose were compared between 38 patients (mean ejection fraction (EF) of 30 ± 8%) with low-dose SWMA and 32 patients (EF 30 ± 11%) without low-dose SWMA. Results: Multivariate analysis showed that the number of coronary territories with severe disease (stenosis ≥70%)(P = 0.001, RR = 6.3) was an independent predictor of low-dose SWMA. An increasing number of collateral vessels protected patients from low-dose SWMA (P = 0.011, RR = 0.25). A higher resting heart rate was a negative predictor of low-dose SWMA (P = 0.015, RR = 0.92) but no other hemodynamic variables were predictors. In the patients with low-dose SMA, regions with low-dose SWMA were more likely to be supplied by vessels with severe disease than regions without low-dose SWMA (92% vs 58%, P < 0.001). Conclusion: In patients with ischemic LV systolic dysfunction, the extent of severe disease and a lower numbers of collaterals predict the occurrence of low-dose SWMA. Low-dose SWMA is a highly specific marker for severe disease.     

Low‐frequency‐induced synaptic potentiation: A paradigm shift in the field of memory‐related plasticity mechanisms?

Long‐term potentiation (LTP) and long‐term depression (LTD) are two forms of synaptic plasticity thought to play functional roles in learning and memory processes. It is generally assumed that the direction of synaptic modifications (i.e., up‐ or down‐regulation of synaptic strength) depends on the specific pattern of afferent inputs, with high frequency activity or stimulation effectively inducing LTP, while low‐frequency patterns often elicit LTD. This dogma (“high frequency‐LTP, low frequency‐LTD”) has recently been challenged by evidence demonstrating low frequency stimulation (LFS)‐induced synaptic potentiation in the rodent hippocampus and amygdala. Extensive work in the past decades has focused on deciphering the mechanisms by which high frequency stimulation of afferent fiber systems results in LTP. With this review, we will compare and contrast the well‐known synaptic and cellular mechanisms underlying classical, high‐frequency‐induced LTP to those mediating the more recently discovered phenomena of LFS‐induced synaptic enhancement. In addition, we argue that LFS protocols provide a means to more accurately mimic some endogenous, oscillatory activity patterns present in hippocampal and extra‐hippocampal (especially neocortical) circuits during periods of memory consolidation. Consequently, LFS‐induced synaptic potentiation offers a novel and important avenue to investigate cellular and systems‐level mechanisms mediating the encoding, consolidation, and transfer of information throughout multiple forebrain networks implicated in learning and memory processes. © 2009 Wiley‐Liss, Inc.