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[The evolution of sleep: birds at the crossroads between mammals and reptiles].

INTRODUCTION: The evolution of sleep is one of the mysteries surrounding the sleep. Since the discovery of the two phases in the mammalian sleep, NREM and REM, the sleep researchers have unsuccessfully tried to understand their origin and the causes of the sleep duality. Looking for an answer to these questions, the sleep of reptiles (the parental group of mammals) and birds (also descending from reptiles) has been studied. As a result, NREM and REM were found in birds but not in reptiles, and the question remains thus unresolved. DEVELOPMENT AND CONCLUSIONS: This review presents a critical analysis of the published sleep studies developed in birds and points to a possible cause of the conflict: considerable doubts can be cast on the existence of the two sleep phases in birds. If birds turn to have only one sleep phase, they would have a very similar sleep to that of reptiles. As a consequence, the two phases, REM and NREM, would be exclusive of mammals, and both would have appeared as a consequence of the evolutionary changes in the development of the brain from reptiles to mammals.

Animals↗

PubMedDate not supplied

Renal disease associated with antineutrophil cytoplasmic antibody: 39 patients over a 5-year period.

We have reviewed 39 adult patients who presented over a 5-year period with biopsy confirmed renal disease in association with positive antineutrophil cytoplasmic antibody (18 with C-ANCA, 21 with P-ANCA). Twenty-three (59%) had primary systemic vasculitis, typically with aggressive renal histology including focal necrotising and crescentic glomerulonephritis. In the remaining patients a wide range of clinical syndromes and renal histological appearances were apparent: 30 had abnormal renal function (serum creatinine > 140 mumol/l), including 17 who were initially dialysis-dependent. Intensive immunosuppression was administered in 33 cases. When response was assessed at 3 months, renal function was stable or improved in 17 (52%), 5 of whom were able to discontinue dialysis. There was, however, an appreciable early mortality and, at latest follow-up (1-57 months), 12 patients had died and 8 were on the dialysis programme. On immunosuppression, ANCA became negative in the majority (median time 1.5 months) but recurred during clinical relapse in 11 cases. In asymptomatic patients (12 cases), the reappearance of ANCA positivity did not herald clinical relapse. The ANCA assay has increased awareness of systemic vasculitis but not removed the need for histological confirmation before instituting immunosuppression.

Adult↗