The secondary structure of bovine serum albumin (BSA) was first examined in the thermal denaturation up to 130 degrees C. The helicity (66%) of the protein decreased with rise of temperature. Half of the original helicity was lost at 80 degrees C, but the helicity of 16% was still maintained even at 130 degrees C. When the BSA solution was cooled down to 25 degrees C after heating at temperatures above 50 degrees C, the helicity was not completely recovered. The higher the thermal denaturation temperature was, the lower was the recovered helicity. On the other hand, upon the addition of sodium dodecyl sulfate (SDS), the secondary structure of BSA was partially protected against the thermal denaturation above 50 degrees C where the structural change became irreversible. A particular protective effect was observed below 85 degrees C upon the coexistence of SDS of extremely low concentrations. For example, the helicity was 34% at 80 degrees C in the absence of SDS, but it was maintained at 58% at the same temperature upon the coexistence of 0.75 mM SDS. Upon cooling down from 80 to 25 degrees C, the helicity of BSA was recovered to 62% in the presence of 0.75 mM SDS. Such a protective effect of SDS was not observed above 95 degrees C. In the interaction with the surfactant, this protein structure appeared likely to have a critical temperature between 90 and 100 degrees C in addition to the critical temperature in the vicinity of 50 degrees C. This protective effect of SDS, characterized by the specific amphiphilic nature of this anionic surfactant, is considered to be attained by building cross-linking bridges between particular nonpolar residues and particular positively charged residues in the protein molecule.

Background and Purpose-Risk-standardized hospital readmission rates are used as publicly reported measures reflecting quality of care. Valid risk-standardized models adjust for differences in patient-level factors across hospitals. We conducted a systematic review of peer-reviewed literature to identify models that compare hospital-level poststroke readmission rates, evaluate patient-level risk scores predicting readmission, or describe patient and process-of-care predictors of readmission after stroke. Methods-Relevant studies in English published from January 1989 to July 2010 were identified using MEDLINE, PubMed, Scopus, PsycINFO, and all Ovid Evidence-Based Medicine Reviews. Authors of eligible publications reported readmission within 1 year after stroke hospitalization and identified Ն1 predictors of readmission in risk-adjusted statistical models. Publications were excluded if they lacked primary data or quantitative outcomes, reported only composite outcomes, or had Ͻ100 patients. Results-Of 374 identified publications, 16 met the inclusion criteria for this review. No model was specifically designed to compare risk-adjusted readmission rates at the hospital level or calculate scores predicting a patient's risk of readmission. The studies providing multivariable models of patient-level and/or process-of-care factors associated with readmission varied in stroke definitions, data sources, outcomes (all-cause and/or stroke-related readmission), durations of follow-up, and model covariates. Few characteristics were consistently associated with readmission. Conclusions-This review identified no risk-standardized models for comparing hospital readmission performance or predicting readmission risk after stroke. Patient-level and system-level factors associated with readmission were inconsistent across studies. The current literature provides little guidance for the development of risk-standardized models suitable for the public reporting of hospital-level stroke readmission performance. (Stroke. 2010;41:2525-2533.)

Background Prompt recognition of acute myocardial infarction (AMI) symptoms and timely care-seeking behavior are critical to optimize acute medical therapies. Relatively little is known about the symptom presentation and care-seeking experiences of women aged ≤55 years with AMI, a group shown to have increased mortality risk as compared with similarly aged men. Understanding symptom recognition and experiences engaging the healthcare system may provide opportunities to reduce delays and improve acute care for this population. Methods and Results We conducted a qualitative study using in-depth interviews with 30 women (aged 30-55 years) hospitalized with AMI to explore their experiences with prodromal symptoms and their decision-making process to seek medical care. Five themes characterized their experiences: 1) prodromal symptoms varied substantially in both nature and duration; 2) they inaccurately assessed personal risk of heart disease and commonly attributed symptoms to non-cardiac causes; 3) competing and conflicting priorities influenced decisions about seeking acute care; 4) the healthcare system was not consistently responsive to them, resulting in delays in workup and diagnosis; and 5) they did not routinely access primary care, including preventive care for heart disease. Conclusions Participants did not accurately assess their cardiovascular risk, reported poor preventive health behaviors, and delayed seeking care for symptoms, suggesting that differences in both prevention and acute care may be contributing to young women's elevated AMI mortality relative to men. Identifying factors that promote better cardiovascular knowledge, improved preventive health care, and prompt care-seeking behaviors represent important targets for this population.

Background:The Joint Commission (JC) began certifying primary stroke centers (PSCs) in the