Biomedical subjects

James C Patterson

Publications and source records attributed to James C Patterson.

6 recordsLinked to original sources

PubMed2006

Reduced presynaptic dopamine activity in fibromyalgia syndrome demonstrated with positron emission tomography: a pilot study.

UNLABELLED: Although the pathophysiology underlying the pain of fibromyalgia syndrome (FMS) remains unknown, a variety of clinical and investigational findings suggests a dysregulation of dopaminergic neurotransmission. We therefore investigated presynaptic dopaminergic function in 6 female FMS patients in comparison to 8 age- and gender-matched controls as assessed by positron emission tomography with 6-[(18)F]fluoro-L-DOPA as a tracer. Semiquantitative analysis revealed reductions in 6-[(18)F]fluoro-L-DOPA uptake in several brain regions, indicating a disruption of presynaptic dopamine activity wherein dopamine plays a putative role in natural analgesia. Although the small sample size makes these findings preliminary, it appears that FMS might be characterized by a disruption of dopaminergic neurotransmission. PERSPECTIVE: An association between FMS and reduced dopamine metabolism within the pain neuromatrix provides important insights into the pathophysiology of this mysterious disorder.

Adult↗

PubMed2006

Novel changes in discoidal high density lipoprotein morphology: a molecular dynamics study.

ApoA-I is a uniquely flexible lipid-scavenging protein capable of incorporating phospholipids into stable particles. Here we report molecular dynamics simulations on a series of progressively smaller discoidal high density lipoprotein particles produced by incremental removal of palmitoyloleoylphosphatidylcholine via four different pathways. The starting model contained 160 palmitoyloleoylphosphatidylcholines and a belt of two antiparallel amphipathic helical lipid-associating domains of apolipoprotein (apo) A-I. The results are particularly compelling. After a few nanoseconds of molecular dynamics simulation, independent of the starting particle and method of size reduction, all simulated double belts of the four lipidated apoA-I particles have helical domains that impressively approximate the x-ray crystal structure of lipid-free apoA-I, particularly between residues 88 and 186. These results provide atomic resolution models for two of the particles produced by in vitro reconstitution of nascent high density lipoprotein particles. These particles, measuring 95 angstroms and 78 angstroms by nondenaturing gradient gel electrophoresis, correspond in composition and in size/shape (by negative stain electron microscopy) to the simulated particles with molar ratios of 100:2 and 50:2, respectively. The lipids of the 100:2 particle family form minimal surfaces at their monolayer-monolayer interface, whereas the 50:2 particle family displays a lipid pocket capable of binding a dynamic range of phospholipid molecules.

Apolipoprotein A-I↗

PubMed2006

Neuropsychological performance, impulsivity, and comorbid psychiatric illness in patients with pathological gambling undergoing treatment at the CORE Inpatient Treatment Center.

INTRODUCTION: Pathologic gambling is a disorder with features that implicate abnormal functioning in brain regions involved in addiction, mood, anxiety, and impulse control disorders. Our goal was to examine brain function with neurocognitive tasks that target these brain regions in patients with pathologic gambling. METHODS: Patients were evaluated for comorbid psychiatric disorders, impulsivity, and performance on reversal-learning and reward-based decision-making cognitive tasks. RESULTS: Patients had higher impulsivity scores and significant deficits on both cognitive tasks compared with controls. All subjects also had comorbid psychiatric disorders, including mood, anxiety, psychotic, and substance abuse. CONCLUSION: The cognitive deficits and impulsivity are consistent with abnormal activity in orbitofrontal-limbic networks. The high level of comorbidity is consistent with the overall severity in these inpatients undergoing treatment, and adds weight to the concept of a fundamental abnormality in this network.

Anxiety↗

PubMed2003

Spectroscopic and density functional studies of the dinitrosyl metalloporphyrin complexes Fe(P)(NO)2 and Ru(P)(NO)2.

Experimental evidence including infrared spectra for the formation of the dinitrosyl metalloporphyrin complexes M(P)(NO)(2) (M = Ru or Fe, P = tetraphenylporphyrin (TPP), octaethylporphyrin (OEP), or tetra-m-tolylporphryin (TmTP)) is described. Although observation of a single NO stretching band in the IR spectrum of each M(P)(NO)(2) complex first suggested a centrosymmetric (D(4)(h)() or C(2)(h)()) structure, DFT geometry optimizations and frequency calculations of model complexes indicate that the trans-syn (C(2)(v)()) conformation should be more stable. The frequency calculations resolve the apparent ambiguity in the IR spectra in terms of the relative oscillator strengths of the predicted IR bands.

Journal Article↗

PubMed2002

Task-independent functional brain activity correlation with skin conductance changes: an fMRI study.

Lesions of the ventromedial prefrontal cortex cause a loss of skin conductance response (SCR) to stimuli with affective content and an inability to integrate information with social consequences into decisions. Previous behavioral studies using a gambling task were able to differentiate patients with lesions in this region from normal subjects. In the present imaging study, this region, among others, was shown to be "spontaneously" activated during three different cognitive states: a gambling task, a working memory task, and resting state. SCR data were simultaneously collected during the scanning process. Six subjects were scanned at 1.5 T during all three states, and one subject was scanned at 3 T during the resting state only. SCR data were used as a reference function for correlation analysis with the fMRI time series during each of the three tasks. SCR changes were evident during the gambling and two-back tasks as well as during rest. SCR activity was not observed to be specifically related to reward-based decisions in the gambling task. Correlation of the fMRI time series directly with the SCR data revealed a consistent set of activated regions. The activity of these regions showing correlation with the SCR appeared independent of the cognitive state. Further, the subject scanned only at rest (without the possible confound of task-related carryover activity) replicated the findings in the original six subjects. From these data, SCR appears to be a marker of a network that is active during, but independent of, the task being studied.

Adult↗

PubMedDate not supplied

How available is positron emission tomography in the United States?

PURPOSE: Positron emission tomography (PET) has become a major clinical diagnostic and prognostic tool for oncology and multiple other arenas. To some, however, the perception exists that PET is not available as a resource in their community. Our goal with this project was to determine how available clinical PET was in the United States. PROCEDURES: We used existing lists of PET centers, websites from PET scanner manufacturers, as well as a common Internet search engine to find clinical PET facilities. A mapping program was then used to determine area coverage with a 75-mile radius for each PET scanner found, and the United States Census website was utilized as a source of population data for covered and not covered areas. RESULTS: We found that 97% of the US population lives within 75 miles of a clinical PET facility. CONCLUSION: Thus, it appears that the idea of clinical PET being unavailable to many is a misconception, which may be limiting its use by some physicians who are unaware of how common it has become.

Equipment and Supplies, Hospital↗