Drug Development.

Background: TREM2 is a lipid-sensing receptor expressed by microglial sub-populations within neuropathological microenvironments, whose downstream signaling promotes microglial survival, plasticity, and migration. Multiple loss-of-function variants strongly implicate TREM2 as a key regulator of Alzheimer's disease (AD) risk. Accordingly, TREM2 antibodies are currently in development to evaluate the therapeutic potential of TREM2 agonism in neurodegenerative diseases.

A Fast-Binding, Functionally Reversible, COX-2 Radiotracer for CNS PET Imaging.

Cyclooxygenase-2 (COX-2) is an enzyme that plays a pivotal role in peripheral inflammation and pain via the prostaglandin pathway. In the central nervous system (CNS), COX-2 is implicated in neurodegenerative and psychiatric disorders as a potential therapeutic target and biomarker. However, clinical studies with COX-2 have yielded inconsistent results, partly due to limited mechanistic understanding of how COX-2 activity relates to CNS pathology.

Microglia and complement mediate early corticostriatal synapse loss and cognitive dysfunction in Huntington's disease.

Huntington's disease (HD) is a devastating monogenic neurodegenerative disease characterized by early, selective pathology in the basal ganglia despite the ubiquitous expression of mutant huntingtin. The molecular mechanisms underlying this region-specific neuronal degeneration and how these relate to the development of early cognitive phenotypes are poorly understood. Here we show that there is selective loss of synaptic connections between the cortex and striatum in postmortem tissue from patients with HD that is associated with the increased activation and localization of complement proteins, innate immune molecules, to these synaptic elements.

Single-Cell RNA Sequencing of Microglia throughout the Mouse Lifespan and in the Injured Brain Reveals Complex Cell-State Changes.

Microglia, the resident immune cells of the brain, rapidly change states in response to their environment, but we lack molecular and functional signatures of different microglial populations. Here, we analyzed the RNA expression patterns of more than 76,000 individual microglia in mice during development, in old age, and after brain injury. Our analysis uncovered at least nine transcriptionally distinct microglial states, which expressed unique sets of genes and were localized in the brain using specific markers.

Metastatic intracranial abscesses of bronchopulmonary origin.

Intracranialabscesses are serious, life-threatening infections despite recent advances in diagnosis and treatment. We report the case of a child with metastatic brain abscesses and a chronic, sharp foreign body of the bronchus. Its presentation and endoscopic appearance and the microbiology of the abscesses are detailed.

A spectrophotometric assay for nanogram quantities of biotin and avidin.

Parameters and conditions of an enzyme based assay for biotin and avidin are presented. Biotinylated glucose-6-phosphate dehydrogenase when complexed with avidin becomes inactivated. Thus it was possible to construct a competitive assay system for biotin.

Improved biotinylation of glucose-6-phosphate dehydrogenase using active-site-blocking agents.

Characteristics of the biotinylation of glucose-6-phosphate dehydrogenase are presented. The enzyme is inactivated in the presence of N-hydroxysuccinimido biotin but can be protected by an appropriate concentration of NADPH used as an active-site blocker. A Ki of 1.