Glial progenitor cells of the adult human white and grey matter are contextually distinct.

Genomic analyses have revealed heterogeneity among glial progenitor cells (GPCs), but the compartment selectivity of human GPCs (hGPCs) is unclear. Here, we asked if GPCs of human grey and white brain matter are distinct in their architecture and associated gene expression. RNA profiling of NG2-defined hGPCs derived from adult human neocortex and white matter differed in their expression of genes involved in Wnt, NOTCH, BMP and TGFß signaling, suggesting compartment-selective biases in fate and self-renewal. White matter hGPCs over-expressed the BMP antagonists BAMBI and CHRDL1, suggesting their tonic suppression of astrocytic fate relative to cortical hGPCs, whose relative enrichment of cytoskeletal genes presaged their greater morphological complexity. In human glial chimeric mice, cortical hGPCs assumed larger and more complex morphologies than white matter hGPCs, and both were more complex than their mouse counterparts. These findings suggest that human grey and white matter GPCs comprise context-specific pools with distinct functional biases.

An unusual presentation of juvenile Alexander disease.

Alexander disease is a rare leukodystrophy that most often presents in infancy but also includes neonatal, juvenile, and adult variants. Juvenile Alexander disease presents primarily with bulbar symptoms between 2 and 12 years of age. The diagnosis is often suggested by the clinical course and brain magnetic resonance image pattern and then confirmed by the presence of a mutation in the glial fibrillary acidic protein gene. A young girl presented with globus sensation and magnetic resonance imaging of the brain revealed abnormalities mainly involving white matter tracts of the medulla oblongata and cerebellum. The presence of a mutation in the glial fibrillary acidic protein gene confirmed the diagnosis of juvenile Alexander disease. A high index of clinical suspicion is necessary for the diagnosis of late-onset presentations of Alexander disease.

Abernethy malformation complicated by hepatopulmonary syndrome and a liver mass successfully treated by liver transplantation.

A seven-yr-old boy presented with persistent oxygen requirement following a respiratory infection. Physical exam was remarkable for orthodeoxia and digital clubbing. Laboratory evaluation showed elevated A-a oxygen gradient of 48 mmHg and mildly elevated transaminases. Sonography showed a 13 cm multilobulated liver mass and a biopsy revealed histological findings consistent with focal nodular hyperplasia. MAA scan revealed 23% right to left shunting. Abdominal CTA and MRV demonstrated the absence of the intrahepatic portal vein with an extrahepatic portocaval shunt. Abernethy malformation is a rare anomalous intra- or extrahepatic communication between portal blood flow and systemic venous return. In rare cases, Abernethy malformation results in HPS. Ours is the sixth case report to describe the co-existence of these two entities. Surgical correction of anomalous hepatic vasculature or liver transplant is imperative to restoration of lung function and also to prevent progression of possible malignant liver tumors. We describe the second patient with Abernethy and HPS who underwent liver transplant with complete resolution of HPS.

Pupillary light reflexes in premature infants prior to 30 weeks postmenstrual age.

Data regarding the pupillary responses in very premature neonates is scarce; what data exist, moreover, is not recent. The purpose of this pilot study is to collect data on direct and consensual pupillary light responses before 30 weeks postmenstrual age. Six neonates were studied. Mean pupillary size at rest was 3.6 +/- 0.4 mm. No direct or consensual responses to light were present in any of 12 eyes. Accurate information about pupillary reflexes in very premature neonates provides relevant information about the development of the visual and neurologic systems. Available information about the development of the Edinger-Westphal nucleus, sphincter pupillary muscle, optic nerve myelinization, and autonomic nervous system is briefly reviewed.