Automated segmentation of MR imaging to determine normative central nervous system cerebrospinal fluid volumes in healthy volunteers.

An accurate non-invasive method to determine total body cerebrospinal fluid volume has a number of potential diagnostic and therapeutic applications. Herein we describe a technique for automated segmentation of total body MRI data to determine cranial and spinal CSF volume in 15 healthy adults. These in vivo estimates of CSF volume exceed the standard reported volume of 150mL in human adults and provide normative data for diagnosis of disease states such as hydrocephalus and therapy including pharmacologic dosimetry.

Cortical laminar binding of PET amyloid and tau tracers in Alzheimer disease.

Unlabelled: Neurofibrillary tau pathology and amyloid β (Aβ) plaques, characteristic lesions of Alzheimer disease (AD), show different neocortical laminar distributions. Neurofibrillary-tangle tau pathology tends to be closer to the gray matter-white matter boundary, whereas Aβ is dispersed throughout the width of the cortical ribbon.

Methods: Using PET radiotracers for tau and Aβ lesions, we developed an image analysis tool to measure the distance of tracer-positive voxels from the gray matter-white matter boundary.

Variability in assessing treatment response: metastatic colorectal cancer as a paradigm.

Purpose: The cutoff values currently used to categorize tumor response to therapy are neither biologically based nor tailored for measurement reproducibility with contemporary imaging modalities. Sources and magnitudes of discordance in response assessment in metastatic colorectal cancer (mCRC) are unknown.

Experimental Design: A subset of patients' CT images of chest, abdomen, and pelvis were randomly chosen from a multicenter clinical trial evaluating insulin-like growth factor receptor type 1-targeted therapy in mCRC.

(11)C-MK-8278 PET as a tool for pharmacodynamic brain occupancy of histamine 3 receptor inverse agonists.

Unlabelled: The histamine 3 (H3) receptor is a presynaptic autoreceptor in the central nervous system that regulates the synthesis and release of histamine and modulates the release of other major neurotransmitters. H3 receptor inverse agonists (IAs) may be efficacious in the treatment of various central nervous system disorders, including excessive daytime sleepiness, attention deficit hyperactivity disorder, Alzheimer disease, ethanol addiction, and obesity.

Methods: Using PET and a novel high-affinity and selective radioligand (11)C-MK-8278, we studied the tracer biodistribution, quantification, and brain H3 receptor occupancy (RO) of MK-0249 and MK-3134, 2 potential IA drugs targeting cerebral H3 receptors, in 6 healthy male subjects (age, 19-40 y).

Alteration of PHYA expression change circadian rhythms and timing of bud set in Populus.

In many temperate woody species, dormancy is induced by short photoperiods. Earlier studies have shown that the photoreceptor phytochrome A (phyA) promotes growth. Specifically, Populus plants that over-express the oat PHYA gene (oatPHYAox) show daylength-independent growth and do not become dormant.