Microglia refine developing retinal astrocytic and vascular networks through the complement C3/C3aR axis.

Microglia, a resident immune cell of the central nervous system (CNS), play a pivotal role in facilitating neurovascular development through mechanisms that are not fully understood. Previous reports indicate a role for microglia in regulating astrocyte density. This current work resolves the mechanism through which microglia facilitate astrocyte spatial patterning and superficial vascular bed formation in the neuroretina during development. Ablation of microglia increased astrocyte density and altered spatial patterning. Mechanistically, we show that microglia regulate the formation of the spatially organized astrocyte template required for subsequent vascular growth, through the complement C3/C3aR axis during neuroretinal development. Lack of C3 or C3aR hindered the developmental phagocytic removal of astrocyte bodies and resulted in increased astrocyte density. In addition, increased astrocyte density was associated with elevated proangiogenic extracellular matrix gene expression in C3- and C3aR-deficient retinas, resulting in increased vascular density. These data demonstrate that microglia regulate developmental astrocyte and vascular network spatial patterning in the neuroretina via the complement axis.

Churg-Strauss syndrome presenting as spontaneous subarachnoid haemorrhage.

Churg-Strauss syndrome (CSS) is a systemic small-vessel vasculitis characterised by the presence of asthma and eosinophilia. Central nervous system involvement (cerebral infarctions or intracerebral haemorrhage) is rare in CSS. Spontaneous subarachnoid hemorrhage (SAH) has been described in other systemic vasculitides. SAH is exceptional in CSS. We present a 47-year-old woman with CSS presenting as a spontaneous SAH with cerebral angiography findings consistent with vasculitis of the basilar artery and without aneurysms or arteriovenous malformations. She received treatment with prednisone and cyclophosphamide, and 2 months later the basilar artery was normal on magnetic resonance angiography.

[Importance of arteriography in the localization of insulinomas. Report of 2 new clinical cases]. / Importancia de la arteriografía en la localización de los insulinomas. Aportación de dos nuevos casos clínicos.

Two new clinical cases of insulinomas are reported, confirming the immense value of selective arteriography of the celiac trunk and upper mesenteric artery in localizing the tumor.