Protamine protects against vancomycin-induced kidney injury.

Vancomycin causes kidney injury by accumulating in the proximal tubule, likely mediated by megalin uptake. Protamine is a putative megalin inhibitor that shares binding sites with heparin and is approved for the treatment of heparin overdose. We employed a well-characterized Sprague-Dawley rat model to assess kidney injury and function in animals that received vancomycin, protamine alone, or vancomycin plus protamine over 5 days.

Impact of humanized vancomycin infusion on kidney function and kidney injury in a translational rat model.

Allometric dose scaling aims to create isometric exposures between animals and humans and is often employed in preclinical pharmacokinetic/pharmacodynamic models. Bolus-administration with allometric scaling is the most simple and commonly used strategy in pre-clinical kidney injury studies; however, it is possible to humanize drug exposures. Currently, it is unknown if dose-matched, bolus-administration with allometric scaling results in similar outcomes compared to humanized infusions in the vancomycin induced kidney injury model.

Toward patient-centered treatment goals for duchenne muscular dystrophy: insights from the "Your Voice" study.

Background: Patient-centered research has emerged as critically important for understanding the impact of treatments on key stakeholders. The subjective experience of quality of life (QOL) is increasingly recognized as fundamental to delineating treatment goals. The present study utilized content analysis of qualitative data and quantitative analysis to highlight important domains of disease burden and underlying reasons for their importance, and to characterize goals for new treatments for Duchenne Muscular Dystrophy (DMD).

Impact of Vancomycin Loading Doses and Dose Escalation on Glomerular Function and Kidney Injury Biomarkers in a Translational Rat Model.

Vancomycin-induced kidney injury is common, and outcomes in humans are well predicted by animal models. This study employed our translational rat model to investigate temporal changes in the glomerular filtration rate (GFR) and correlations with kidney injury biomarkers related to various vancomycin dosing strategies. First, Sprague-Dawley rats received allometrically scaled loading doses or standard doses.

Healthcare access, satisfaction, and health-related quality of life among children and adults with rare diseases.

Background: Research in a variety of countries indicates that healthcare access and health-related quality of life are challenged among people with a variety of rare diseases (RDs). However, there has been little systematic research on the experiences of children and adults with RDs in the American healthcare system that identifies commonalities across RDs. This research aimed to: (1) Describe demographics, disease characteristics, diagnostic experiences, access to healthcare, knowledge about RDs, support from healthcare professionals, and patient satisfaction among people with RDs and their caregivers; (2) examine predictors of patient satisfaction among adults with RDs; (3) compare health-related quality of life and stigma to US population norms; 4) examine predictors of anxiety and depression among adults and children with RDs.

Tropomyosin dephosphorylation results in compensated cardiac hypertrophy.

Phosphorylation of tropomyosin (Tm) has been shown to vary in mouse models of cardiac hypertrophy. Little is known about the in vivo role of Tm phosphorylation. This study examines the consequences of Tm dephosphorylation in the murine heart.

Differential effects of phosphorylation of regions of troponin I in modifying cooperative activation of cardiac thin filaments.

Ischemia and heart failure are associated with protein kinase C (PKC) dependent phosphorylation of cardiac troponin I (cTnI). We investigated the effect of phosphorylation of cTnI PKC sites S43, S45 and T144 under normal (pH 7.0) and acidic (pH 6.

Structural basis for the regulation of muscle contraction by troponin and tropomyosin.

The molecular switching mechanism governing skeletal and cardiac muscle contraction couples the binding of Ca2+ on troponin to the movement of tropomyosin on actin filaments. Despite years of investigation, this mechanism remains unclear because it has not yet been possible to directly assess the structural influence of troponin on tropomyosin that causes actin filaments, and hence myosin-crossbridge cycling and contraction, to switch on and off. A C-terminal domain of troponin I is thought to be intimately involved in inducing tropomyosin movement to an inhibitory position that blocks myosin-crossbridge interaction.

Identification of a region of troponin I important in signaling cross-bridge-dependent activation of cardiac myofilaments.

Force generating strong cross-bridges are required to fully activate cardiac thin filaments, but the molecular signaling mechanism remains unclear. Evidence demonstrating differential extents of cross-bridge-dependent activation of force, especially at acidic pH, in myofilaments in which slow skeletal troponin I (ssTnI) replaced cardiac TnI (cTnI) indicates the significance of a His in ssTnI that is an homologous Ala in cTnI. We compared cross-bridge-dependent activation in myofilaments regulated by cTnI, ssTnI, cTnI(A66H), or ssTnI(H34A).

Cardiac troponin T isoforms affect the Ca(2+) sensitivity of force development in the presence of slow skeletal troponin I: insights into the role of troponin T isoforms in the fetal heart.

In this study we investigated the physiological role of the cardiac troponin T (cTnT) isoforms in the presence of human slow skeletal troponin I (ssTnI). ssTnI is the main troponin I isoform in the fetal human heart. In reconstituted fibers containing the cTnT isoforms in the presence of ssTnI, cTnT1-containing fibers showed increased Ca(2+) sensitivity of force development compared with cTnT3- and cTnT4-containing fibers.