The relationship between frontal gray matter volume and cognition varies across the healthy adult lifespan.

Objective: Age-associated decline in gray matter brain volume and cognitive function in healthy adults has been reported in the literature. The goal of the current study is to examine the relationship between age-related changes in regional gray matter volumes and cognitive function in a large, cross-sectional sample of healthy adults across the lifespan.

Methods: Magnetic resonance imaging and cognitive assessment were conducted on 148 adults aged 21-76 years.

Brain maturation in adolescence: concurrent changes in neuroanatomy and neurophysiology.

Adolescence to early adulthood is a period of dramatic transformation in the healthy human brain. However, the relationship between the concurrent structural and functional changes remains unclear. We investigated the impact of age on both neuroanatomy and neurophysiology in the same healthy subjects (n = 138) aged 10 to 30 years using magnetic resonance imaging (MRI) and resting electroencephalography (EEG) recordings.

Progressive grey matter atrophy over the first 2-3 years of illness in first-episode schizophrenia: a tensor-based morphometry study.

Little is known about the structural brain changes that occur over the first few years of schizophrenia, or how these changes differ from those associated with healthy brain development in adolescence and early adulthood. In this study, we aimed to identify regional differences in grey matter (GM) volume between patients with first-episode schizophrenia (FES) and matched healthy controls, both at the time of the patients' first psychotic episode (baseline condition) and 2-3 years subsequently (follow-up condition). Forty-one patients with FES and 47 matched healthy controls underwent a T1-weighted structural MRI scan.

Regional white matter and neuropsychological functioning across the adult lifespan.

Background: The current study utilized magnetic resonance imaging (MRI) to more fully elucidate the relationship among age, regional white matter, and neuropsychological functioning.

Methods: One hundred ninety-nine neurologically healthy adults received MRI and standardized neuropsychological assessment. MR images were spatially normalized and segmented by tissue type; relative white matter values in each of the four cerebral lobes in each hemisphere were computed.

Early life stress and morphometry of the adult anterior cingulate cortex and caudate nuclei.

Background: Early life stress (ELS) is linked to adult psychopathology and may contribute to long-term brain alterations, as suggested by studies of women who suffered childhood sexual abuse. We examine whether reported adverse ELS defined as stressful and/or traumatic adverse childhood events (ACEs) is associated with smaller limbic and basal ganglia volumes.

Method: 265 healthy Australian men and women without psychopathology or brain disorders were studied.

Orientational order of Australian spider silks as determined by solid-state NMR.

A simple solid-state NMR method was used to study the structure of (13)C- and (15)N-enriched silk from two Australian orb-web spider species, Nephila edulis and Argiope keyserlingi. Carbon-13 and (15)N spectra from alanine- or glycine-labeled oriented dragline silks were acquired with the fiber axis aligned parallel or perpendicular to the magnetic field. The fraction of oriented component was determined from each amino acid, alanine and glycine, using each nucleus independently, and attributed to the ordered crystalline domains in the silk.

Urinary albumin levels in the normal range determine arterial wall thickness in adults with Type 2 diabetes: a FIELD substudy.

Aim: Cardiovascular disease (CVD) rates are substantially higher among patients with Type 2 diabetes than in the general population. The objective of this study was to identify the determinants of carotid intima media thickness (IMT) in patients with Type 2 diabetes.

Methods: We measured the thickness of the intima media layer of the carotid artery, a strong predictor of the risk of future vascular events, in 397 Type 2 diabetic patients drawn from the Fenofibrate Intervention and Event Lowering in Diabetes study, prior to treatment allocation.

Neural synchrony and gray matter variation in human males and females: integration of 40 Hz gamma synchrony and MRI measures.

Coherent cognition requires activity to be brought together across diverse brain networks. Synchronous, in-phase oscillations in the high-frequency (40 Hz) Gamma range are thought to be one mechanism underlying the functional integration of brain networks. While sex differences have been observed across a range of cognitive functions, their role in normal cortical synchronization has not been elucidated.

Subcortical hyperintensities impact cognitive function among a select subset of healthy elderly.

Previous studies have examined the impact of subcortical hyperintensities (SH), a proxy measure of cerebrovascular disease, on the cognitive abilities of otherwise healthy older adults. However, there remains a limited understanding as to what extent this MRI marker of pathological processes explains the decline in specific cognitive functions that occur nearly ubiquitously with advanced age, especially in relation to other age-related imaging markers. In the present study we compared cognitive abilities between a sample of 53 older healthy adults (age range=50-79) and a sample of 53 younger adults (age range=21-40).

Preservation of limbic and paralimbic structures in aging.

Patterns of gray matter (GM) loss were measured in 223 healthy subjects spanning eight decades. We observed significant clusters of accelerated loss in focal regions of the frontal and parietal cortices, including the dorsolateral frontal cortex, pre- and postcentral gyrus, and the inferior and superior parietal lobes. The rate of loss in these clusters was approximately twice that of the global average.

Assessment of motion gating strategies for mouse magnetic resonance at high magnetic fields.

Purpose: To assess the performance of motion gating strategies for mouse cardiac magnetic resonance (MR) at high magnetic fields by quantifying the levels of motion artifact observed in images and spectra in vivo.

Materials And Methods: MR imaging (MRI) of the heart, diaphragm, and liver; MR angiography of the aortic arch; and slice-selective 1H-spectroscopy of the heart were performed on anesthetized C57Bl/6 mice at 11.75 T.

Fast, high-resolution in vivo cine magnetic resonance imaging in normal and failing mouse hearts on a vertical 11.7 T system.

Purpose: To establish fast, high-resolution in vivo cine magnetic resonance imaging (cine-MRI) on a vertical 11.7-T MR system and to investigate the stability of normal and failing mouse hearts in the vertical position.

Materials And Methods: To optimize the method on a high-field system, various MR-related parameters, such as relaxation times and the need for respiratory gating, were quantitatively investigated.

Differences in the BOLD fMRI response to direct and indirect cortical stimulation in the rat.

Functional MRI (fMRI) exploits a relationship between neuronal activity, metabolism, and cerebral blood flow to functionally map the brain. We have developed a model of direct cortical stimulation in the rat that can be combined with fMRI and used to compare the hemodynamic responses to direct and indirect cortical stimulation. Unilateral electrical stimulation of the rat hindpaw motor cortex, via stereotaxically positioned carbon-fiber electrodes, yielded blood oxygenation level-dependent (BOLD) fMRI signal changes in both the stimulated and homotypic contralateral motor cortices.

High-resolution, high-throughput magnetic paragraph sign resonance imaging of mouse embryonic paragraph sign anatomy using a fast gradient-echo sequence.

Embryonic development in normal and genetically modified mice is commonly analysed by histological sectioning. This procedure is time-consuming, prone to artefact, and results in the loss of three-dimensional (3D) information. Magnetic resonance imaging (MRI) of embryos has the potential of noninvasively acquiring a complete 3D data set.

Electromagnetic characterisation of MR RF coils using the transmission-line modelling method.

The Transmission-Line Modelling (TLM) method is applied to the electromagnetic characterisation of RF coils and samples for magnetic resonance imaging MRI. Theoretical verification was performed using a simple surface coil. Experimental verification was performed using Alderman-Grant and birdcage coils constructed for use on a 7 T micro-imaging system.

Elimination of Nyquist ghosting caused by read-out to phase-encode gradient cross-terms in EPI.

Echo-planar imaging (EPI) commonly suffers from ghosting artifacts caused by zero- or first-order phase differences between the odd and even echoes that constitute an EPI dataset. Small-bore imaging systems with shielded gradients may suffer significantly from cross-term eddy currents due to the high degree of manufacturing precision required in such systems compared to larger whole-body coils. A Nyquist ghost caused by cross-term eddy current contributions from the read-out to the phase-encode axis was identified in a small-bore system and characterized using a modified EPI experiment and a computer simulation.

Prenatal education for mothers with disabilities.

Prenatal nurse educators are well prepared to meet the learning needs of many expectant mothers. But how prepared are they to meet the learning needs of mothers with disabilities? To answer this question, eight mothers with various chronic illnesses located in north-eastern Ontario, Canada were asked to describe their maternity experiences. Given the small convenience sample and exploratory nature of the study, a qualitative content analysis was done.

Local and systemic effects of intra-arterial desmopressin in healthy volunteers and patients with type 3 von Willebrand disease. Role of interleukin-6.

Intra-arterial desmopressin caused dose and time dependent increases (p <0.001 for all) in forearm blood flow (all doses) and plasma tissue plasminogen activator (t-PA) concentrations (desmopressin > or = 70 ng/min). Although plasma t-PA concentrations rose in both forearms, there was a modest local release of t-PA in the infused forearm (14 ng/100 mL of tissue/min, p <0.

The effect of bulk susceptibility on murine snapshot imaging at 7.0 T: a comparison of snapshot imaging techniques.

The sensitivity of several single-shot imaging techniques to local field gradients (LFGs) generated by discontinuities in bulk magnetic susceptibility (BMS) were compared in mouse brain at 7.0 T. At high field, differences in BMS can cause substantial signal attenuation and image distortion.

Multiple-quantum filtered 17Q and 23Na NMR analysis of mitochondrial suspensions.

The fraction of strongly- and weakly-bound water molecules within mitochondrial suspensions, determined using three-quantum filtered 17O NMR relaxation analysis, was found to be large in comparison with that in erythrocytes and concentrated solutions of bovine serum albumen. It is suggested that bound water, together with regulation of mitochondrial matrix volume, may be an important controlling factor in the modulation of enzymic activity in the matrix. A spin I = 5/2 Jeener-Broekaert experiment and a four-quantum filtration experiment were used to demonstrate the absence of orientationally ordered water molecules within the mitochondrion.

NMR triple-quantum filtered relaxation analysis of 17O-water in insulin solutions: an insight into the aggregation of insulin and the properties of its bound water.

Transverse triple-quantum filtered NMR spectroscopy (TTQF) of 17O-water was used to study the properties of water in insulin solutions at different Zn2+ concentrations and pH values. It was established that strongly bound water molecules are already present in Zn-free insulin. On the assumption that the effective correlation time of a strongly bound water molecule, tau sb, is 10 ns, the apparent number of strongly bound water molecules was approximately 3 to 4 per insulin monomer.

Measuring morale--does practice area deprivation affect doctors' well-being?

Background: Morale is a perennial concern in general practice and, over the years, a variety of tools have been used to examine doctors' mental well-being in a range of psychological and sociological studies. Despite perceived associations between low morale and practice area deprivation, this has not been investigated previously.

Aim: To devise and apply a measure of mental well-being in general practitioners, and to use this to investigate the effect of practice area deprivation.

Comparison of two different pulse oximeters in monitoring preterm infants.

Objective: The aim of the study was to test the reliability and variation in the readings of two widely used pulse oximeters in preterm infants.

Design: Two different pulse oximeters and a transcutaneous PO2 monitor were used to record the data continuously on a cotside computer database.

Patients: Sixteen preterm infants were studied in the Neonatal Unit, Simpson Memorial Maternity Pavilion, Edinburgh, UK.