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Biomedical subjects

G Cole

Publications and source records attributed to G Cole.

At least 19 recordsLinked to original sources
PubMed2003

The effect of material characteristics of shoe soles on muscle activation and energy aspects during running.

The purposes of this study were (a) to determine group and individual differences in oxygen consumption during heel-toe running and (b) to quantify the differences in EMG activity for selected muscle groups of the lower extremities when running in shoes with different mechanical heel characteristics. Twenty male runners performed heel-toe running using two shoe conditions, one with a mainly elastic and a visco-elastic heel. Oxygen consumption was quantified during steady state runs of 6 min duration, running slightly above the aerobic threshold providing four pairs of oxygen consumption results for comparison. Muscle activity was quantified using bipolar surface EMG measurements from the tibialis anterior, medial gastrocnemius, vastus medialis and the hamstrings muscle groups. EMG data were sampled for 5 s every minute for the 6 min providing 30 trials. EMG data were compared for the different conditions using an ANOVA (alpha=0.05). The findings of this study showed that changes in the heel material characteristics of running shoes were associated with (a) subject specific changes in oxygen consumption and (b) subject and muscle specific changes in the intensities of muscle activation before heel strike in the lower extremities. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.

Elasticity↗
PubMed2003

The American Urological Association In-Service Examination: performance correlates with Canadian and American specialty examinations.

PURPOSE: To our knowledge literature that correlates American Urological Association In-Service Examination (AUA ISE) scores with performance on final specialty examinations is lacking. We report an analysis of Canadian resident performance on the AUA ISE in relation to the Royal College of Physicians and Surgeons of Canada Certifying Examinations in Urology (RCPSCE) and the American Board of Urology Qualifying Examination Part 1 (ABU 1). MATERIALS AND METHODS: During the 5-year period 1997 to 2001 AUA ISE scores were analyzed from 91 final year residents attempting the RCPSCE and a subset of 43 of the 91 (47%) attempting ABU 1. Blinded correlation of scores on the AUA ISE with RCPSCE and ABU 1 was performed. RESULTS: Final year postgraduate year (PGY 5) AUA ISE results correlated strongly with the RCPSCE (r = 0.68, p <0.001) and ABU 1 (r = 0.600, p <0.001). PGY 4 and PGY 3 scores showed a statistically significant correlation, while PGY 2 performance did not meet statistical significance. For the RCPSCE a cutoff point could be determined for pass/failure, namely an AUA ISE raw score of 43% to 55% equaled a 75% pass, a score of 55% to 70% equaled a 88% pass and greater than 70% resulted in a 100% pass. The probability of scoring 70% or greater on ABU 1 as a best guess estimate of successful certification could also be predicted based on AUA ISE raw scores. CONCLUSIONS: The AUA ISE is a good predictor of performance on Canadian and American specialty examinations with the strongest correlation in the final year of residency.

Canada↗
PubMed2001

Predicting performance on the Royal College of Physicians and Surgeons of Canada internal medicine written examination.

BACKGROUND: Although the written component of the Royal College of Physicians and Surgeons of Canada (RCPSC)internal medicine examination is important for obtaining licensure and certification as a specialist, no methods exist to predict a candidate's performance on the examination. METHOD: We obtained data from 5 Canadian universities from 1988 to 1998 in order to compare raw scores from the American Internal Medicine In-Training Examination (AIMI-TE) with raw scores and outcomes (pass or fail) of the written component of the RCPSC internal medicine examination. RESULTS: Mean scores on the AIMI-TE correlated well with scores on the RCPSC internal medicine written examination for all postgraduate years (r = 0.62, r = 0.55 and r = 0.65 for postgraduate years 1, 2 and 3 respectively). Scores above the 50th percentile on the AIMI-TE w/ere predictive of a low failure rate (< 1.5%) on the RCPSC internal medicine written examination, whereas scores at or below the 10th percentile were associated with a high failure rate (about 24%). INTERPRETATION: Candidates who are eligible to take the written component of the RCPSC certification examination in internal medicine can use the AIMI-TE to predict their performance on the Canadian examination. The AIMI-TE is a useful test for residents in all levels of training, because the examination scores have a strong relation to expected performance on the Canadian examination for each year of postgraduate training.

Canada↗
PubMed2001

African Americans' views on research and the Tuskegee Syphilis Study.

The participation of African Americans in clinical and public health research is essential. However, for a multitude of reasons, participation is low in many research studies. This article reviews the literature that substantiates barriers to participation and the legacy of past abuses of human subjects through research. The article then reports the results of seven focus groups with 60 African Americans in Los Angeles, Chicago, Washington, DC, and Atlanta during the winter of 1997. In order to improve recruitment and retention in research, the focus group study examined knowledge of and attitudes toward medical research, knowledge of the Tuskegee Syphilis Study, and reactions to the Home Box Office production, Miss Evers' Boys, a fictionalized version of the Tuskegee Study, that premiered in February, 1997. The study found that accurate knowledge about research was limited; lack of understanding and trust of informed consent procedures was problematic; and distrust of researchers posed a substantial barrier to recruitment. Additionally, the study found that, in general, participants believed that research was important, but they clearly distinguished between types of research they would be willing to consider participating in and their motivations for doing so.

Black or African American↗
PubMed2001

Effect of object onset on the distribution of visual attention.

There now exists considerable evidence to suggest that the appearance of a new object in the visual field captures visual attention. One of the consequences of this attentional capture is that the object initiates a redistribution of attentional resources across visual space. This is classically observed in the precuing paradigm in which the onset of an abrupt cue influences the processing of a subsequently presented target. The present research describes a new phenomenon that occurs as a result of a new object appearing in the visual field. A stimulus presented in a region of space adjacent to a corner of an onsetting object receives an enhancement of processing relative to a stimulus presented adjacent to one of the object's straight edges. With the use of 2 converging methods, evidence is presented that suggests that the effect is a higher order attentional phenomenon whereby greater resources become directed to the corners of objects.

Attention↗
PubMed2000

Accuracy of target detection in new-object and old-object displays.

In 4 experiments, the authors investigated accuracy of detecting a target among nontargets. In some experiments, the target was a second-order square of stationary lines on a background of downward-moving lines, and nontargets were second-order squares of upward-moving lines. In other experiments, target and nontarget squares and background were shades of gray. The principal comparison was between "new" and "old" object displays. In new-object displays, search items appeared abruptly and one might be a target. In old-object displays, search items appeared abruptly, and after a delay one might become a target. Search displays in both conditions terminated shortly after target onset. Except when target onset was associated with the sole luminance change in a display, targets were much better detected in new- than in old-object displays. It is suggested that object onsets elicit a brief stimulus-driven enhancement of attention to the new objects.

Attention↗
PubMed1999

Mapping biochemistry to metabolism: FDG-PET and amyloid burden in Alzheimer's disease.

We evaluated the relationship between amyloid-beta protein (A beta) concentration and the metabolic abnormality in an Alzheimer's disease (AD) patient as measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Across most regions there were significant inverse correlations among FDG-PET intensity values and both insoluble. The temporal lobe samples showed no significant correlation between FDG-PET values and A beta deposition. Findings support A beta as contributing to the hypometabolism in regions of the AD brain that are still relatively viable metabolically; those regions with chronic pathologic damage, such as temporal cortex, may have other factors that contribute to metabolic deficits.

Aged↗
PubMed1999

Disulfide bond reduction: A powerful, chemical probe for the study of structure-function relationships in the hemocyanins.

The copper-containing hemocyanins are a class of oxygen-transport proteins whose structures differ in arthropods and molluscs. Crystal structure analyses and amino acid sequence comparisons show that disulfide bonding is a common feature in both arthropod and mollusc hemocyanins. Reduction of the disulfide bonds of a representative set of arthropod and mollusc hemocyanins results in complete loss of their oxygen-binding capacities. Thus, retention of the disulfide bonds is essential to the functional integrity of the oxygen-binding sites in the subunits of this class of oxygen carriers, despite the very different architectures of the arthropod and mollusc molecules. Depending upon the specific hemocyanin, partial to virtually complete restoration of the oxygen-binding capacity occurs when the disulfide-bond reductant is removed by dialysis. The rate at which the functional, active-site geometry is lost and the extent to which it can be restored varies markedly with hemocyanin type, aggregation state, and experimental conditions. Consequently, a comparison of these differences provides a simple, but powerful, way to probe internal and environmental factors that govern physiologically important structure-function relationships in this entire class of oxygen-transport proteins.

Animals↗
PubMed1999

Neuronal death and survival in two models of hypoxic-ischemic brain damage.

Two unilateral hypoxic-ischemia (HI) models (moderate and severe) in immature rat brain have been used to investigate the role of various transcription factors and related proteins in delayed neuronal death and survival. The moderate HI model results in an apoptotic-like neuronal death in selectively vulnerable regions of the brain while the more severe HI injury consistently produces widespread necrosis resulting in infarction, with some necrosis resistant cell populations showing evidence of an apoptotic type death. In susceptible regions undergoing an apoptotic-like death there was not only a prolonged induction of the immediate early genes, c-jun, c-fos and nur77, but also of possible target genes amyloid precursor protein (APP751) and CPP32. In contrast, increased levels of BDNF, phosphorylated CREB and PGHS-2 were found in cells resistant to the moderate HI insult suggesting that these proteins either alone or in combination may be of importance in the process of neuroprotection. An additional feature of both the moderate and severe brain insults was the rapid activation and/or proliferation of glial cells (microglia and astrocytes) in and around the site of damage. The glial response following HI was associated with an upregulation of both the CCAAT-enhancer binding protein alpha (microglia only) and NFkappaB transcription factors.

Animals↗
PubMed1999

Do equiluminant object onsets capture visual attention?

S. Yantis and A. P. Hillstrom (1994) have claimed that abrupt onset of a new visual object captures attention even when the new object is equiluminant with its background, implying that attention is captured at the level of object descriptions rather than at the level of luminance change detection. S. Yantis and A. P. Hillstrom's experiments contained potential flaws that call their conclusion into question. The present article reports 5 experiments investigating these and related issues. The results suggest that for abruptly onsetting visual objects to capture attention, detection of change in a dimension of sensory stimulation is a necessary, but perhaps not a sufficient, requirement. Evidence is also presented against the view that attentional priority for new objects arises as a result of visual masking of old objects in the same displays.

Adult↗
PubMed1999

Social Security fixes--beware of conjurers!

Among the many proposals for reform, there is one that offers the best chance of truly solving Social Security's financial problems, these authors believe. That proposal would increase savings by requiring workers to invest an additional 2% of their covered wages in individual accounts. At retirement, 75% of the money would go toward buying the current level of Social Security benefits, and 25% would be given to the individual as an "extra" pension. Individuals, not the government, would control investment of these accounts.

Actuarial Analysis↗
PubMed1998

Untangling the effects of hunger, anxiety, and nausea on energy intake during intravenous cholecystokinin octapeptide (CCK-8) infusion.

Infusions of cholecystokinin (CCK) may exert their effects on appetite by inducing feelings of nausea or anxiety. In this double blind, placebo controlled crossover study, the impact of these effects on appetite were examined. Fifteen male subjects received a 20 min i.v. infusion of cholecystokinin octapeptide (CCK-8) (4 ng/kg/min) or saline. The infusion commenced 20 min after a soup preload and 10 min before an ad libitum test meal. Visual analogue scales of appetite and mood were measured over 3 h, and subjects were instructed to report any other sensations they experienced over this time. CCK-8 significantly reduced premeal hunger, elevated premeal anxiety, and reduced energy intake at the ad libitum test meal. Meal duration and rate of eating (kcal/min) were also significantly reduced after CCK-8. After the smaller meal with CCK-8, hunger rose quickly to a higher level than with placebo. The return of hunger was commensurate with the smaller amount of energy consumed and indicated that CCK did not exert an enduring effect on hunger suppression. A significant correlation was found between the reduction in energy intake and hunger (r = 0.75 p < 0.01), but not with anxiety (r = 0.15 not significant). Analyses were performed separately on subjects who did (n = 8), or did not (n = 7) report gastrointestinal disturbance. Energy intake was reduced by 56.6% and 44.6%, respectively. These results indicate that, although feelings of anxiety and nausea may accompany CCK infusions, they are not necessary for the effects of CCK on appetite. These data provide support for a role of CCK in satiety.

Adolescent↗
PubMed1998

Active-site disruption in native Limulus hemocyanin and its subunits by disulfide-bond reductants: a chemical probe for the study of structure-function relationships in the hemocyanins.

The crystal structure analysis of Subunit II of Limulus hemocyanin has shown that its polypeptide chain is folded into three distinct structural domains. The oxygen-binding, dinuclear copper center is located deep in the core of Domain 2. Two disulfide bonds are located in a bridging domain, Domain 3. These disulfide bonds are remote from the oxygen-binding site, but are positioned so that they could affect its stability. When the disulfide bonds are broken by dithiothreitol or other disulfide-bond reductants, the 340-nm absorption band, associated with oxygen binding, is lost. Disulfide-bond reductants also cause the loss of the oxygen-binding capacity of all seven of the other subunits of Limulus hemocyanin. Thus, disulfide bonding is a general feature of the Limulus hemocyanin subunits that is important to the maintenance of the physiologically effective geometry of the oxygen-binding site. The rate of loss of oxygen-binding capacity, however, is highly dependent on subunit type, aggregation state, and protein conformation. Evidence that protein conformation markedly affects the rate of disruption of the oxygen-binding site comes from the finding that the addition of dithiothreitol to fully oxygenated samples results in a slow initial loss of oxygen-binding capacity followed by an appreciably faster reaction rate. In contrast, in the deoxygenated conformation, the reaction rate is monophasic and never attains the faster rates observed for oxygenated samples. When the disulfide bonds are broken and oxygen-binding capacity is lost, there is subunit-specific variability in the extent of polypeptide-chain unfolding, subunit aggregation, and loss of active-site copper ions. When the disulfide-bond reductant is removed by dialysis so that disulfide bonds can re-form, there is also subunit-specific variability in the extent of restoration of oxygen-binding capacity. Complete restoration of structure and function as the disulfide bonds re-form occurs only for the 48-subunit native molecule, whose architecture is stabilized by bound Ca2+ and extensive intersubunit contacts. We have found a similar loss of oxygen-binding capacity upon breaking disulfide bonds in a number of other arthropod and mollusc hemocyanins, suggesting that the active site of Limulus hemocyanin is not unique in its dependence upon intact disulfides. The results presented in this paper suggest that disulfide-bond reduction may provide a simple, but powerful, chemical tool with which to probe internal and environmental factors that govern physiologically important structure-function relationships in the hemocyanins.

Animals↗
PubMed1998

Tiagabine: absence of kinetic or dynamic interactions with ethanol.

Tiagabine is a new antiepileptic drug that inhibits the uptake of gamma-aminobutyric acid into neurons and glia. This double-blind, placebo-controlled study investigated the effect of multiple doses of tiagabine on the adverse cognitive effects produced by a single dose of ethanol in 20 healthy volunteers. The effects of each drug on the pharmaco-kinetics of the other were also determined. Compared with placebo, tiagabine produced no statistically significant effects on digit vigilance speed (primary assessment variable) or accuracy, choice reaction time, immediate or delayed word recall, delayed word recognition speed or sensitivity, visual tracking, body sway, or subjective measures of alertness, calmness, and contentment. There was no evidence of a pharmacodynamic interaction between tiagabine and ethanol with respect to these variables. The pharmacokinetic parameters of tiagabine and ethanol (maximum plasma concentration [Cmax], time to Cmax and area under the plasma concentration-time curve) were unchanged during concomitant administration. Adverse events, which mainly affected the central nervous system, occurred with a similar incidence during tiagabine and placebo administration and were more common after the administration of ethanol. There appears to be no need for additional caution regarding driving or operating machinery when ethanol is administered to patients taking tiagabine.

Adult↗
PubMed1998

Using "stages of behavioral change" constructs to measure the short-term effects of a worksite-based intervention to increase moderate physical activity.

We evaluated a three-level incentive program to promote regular, moderate physical activity among employees working in a federal agency. The objective was to assess the short-term effects of the intervention by examining the stages people go through as they attempt to make permanent changes in physical activity. Indicators of the process by which changes in physical activity take place were based on a modified version of the Transtheoretical Model of Behavior. A one-group pretest/posttest design was used to ascertain which of the stages the 1,192 participants were in both before and after the intervention. Analysis indicated that, of the 1,192 participants, 6.5% regressed one or more stages, 30.3% did not regress or progress from one stage to another, 27.7% remained in the maintenance stage, and 35.4% progressed one (21.1%) or more (14.3%) stages during the 50-day intervention. Among those who progressed, the most common change was from preparation to late preparation (20.8%) and from late preparation to action (19.4%). Findings reinforce the notion that the stages of change concept can serve as indicators of the change process which in turn, can be used as evidence of the short-term effectiveness of interventions. Findings also indicate this type of intervention holds promise for increasing physical activity among willing participants of a worksite population.

Behavior Therapy↗
PubMed1997

Spheroid body myopathy revisited.

Having reported spheroid body myopathy from Indiana (IN) inherited in an autosomal-dominant fashion several years ago, we now describe additional findings from the Oregon branch--briefly recorded earlier--and confirm earlier studies in another clinically affected IN member of this kinship demonstrating identical spheroid bodies within the myopathic muscle specimens. The spheroid bodies also contained increased amounts of desmin, alpha-B crystallin, and ubiquitin within muscle fibers. Our studies now have established that spheroid body myopathy is a member of the growing family of desminopathic neuromuscular conditions.

Adult↗