[CASE REPORT: LEGAL, PSYCHOLOGICAL AND ETHICAL ASPECTS OF THE DYING PATIENT ACT].

INTRODUCTION: We present a patient with amyotrophic lateral sclerosis (ALS), dependent on noninvasive ventilation, whose advance directives precluded life-prolonging measures. The patient was found in cardiac arrest and in accordance with the directives of her surrogate decision maker, underwent intubation and mechanical ventilation. Later, an additional surrogate decision maker disapproved of ventilation and when the ventilator was disconnected for bronchial suctioning, she asked the nurse not to reconnect the patient to the ventilator. We discuss the legal, psychological and ethical aspects of implementation of Israeli law in this complex patient.

Strengths of hydrogen bonds involving phosphorylated amino acid side chains.

Post-translational phosphorylation plays a key role in regulating protein function. Here, we provide a quantitative assessment of the relative strengths of hydrogen bonds involving phosphorylated amino acid side chains (pSer, pAsp) with several common donors (Arg, Lys, and backbone amide groups). We utilize multiple levels of theory, consisting of explicit solvent molecular dynamics, implicit solvent molecular mechanics, and quantum mechanics with a self-consistent reaction field treatment of solvent. Because the approximately 6 pKa of phosphate suggests that -1 and -2 charged species may coexist at physiological pH, hydrogen bonds involving both protonated and deprotonated phosphates for all donor-acceptor pairs are considered. Multiple bonding geometries for the charged-charged interactions are also considered. Arg is shown to be capable of substantially stronger salt bridges with phosphorylated side chains than Lys. A pSer hydrogen-bond acceptor tends to form more stable interactions than a pAsp acceptor. The effect of phosphate protonation state on the strengths of the hydrogen bonds is remarkably subtle, with a more pronounced effect on pAsp than on pSer.