Biomedical subjects

Terry Brown

Publications and source records attributed to Terry Brown.

10 recordsLinked to original sources

PubMed2006

Practice parameters for the medical therapy of obstructive sleep apnea.

Therapies for obstructive sleep apnea other than positive airway pressure, oral appliances, and surgical modifications of the upper airway are reviewed in this practice parameter. Several of these therapies such as weight loss and positional therapy hold some promise. Others, such as serotonergic agents, may gain credibility in the future but lack well-designed clinical trials. No practice parameters could be developed for a number of possible therapeutic modalities that had little or no evidence-based data on which to form a conclusion. The role of an organized, targeted weight-loss program either as a single therapy or as a supplement to PAP needs to be clarified. Although bariatric surgery is increasingly performed for refractory medically complicated obesity, its long-term effectiveness in treatment of obstructive sleep apnea in morbidly obese patients is not yet demonstrated. Positional therapy, or methods for preventing sleep in the supine position, has probably been underutilized due to lack of easily measured predictive factors and randomized controlled trials.

Combined Modality Therapy↗

PubMed2006

Practice parameters for the psychological and behavioral treatment of insomnia: an update. An american academy of sleep medicine report.

Insomnia is highly prevalent, has associated daytime consequences which impair job performance and quality of life, and is associated with increased risk of comorbidities including depression. These practice parameters provide recommendations regarding behavioral and psychological treatment approaches, which are often effective in primary and secondary insomnia. These recommendations replace or modify those published in the 1999 practice parameter paper produced by the American Sleep Disorders Association. A Task Force of content experts was appointed by the American Academy of Sleep Medicine to perform a comprehensive review of the scientific literature since 1999 and to grade the evidence regarding non-pharmacological treatments of insomnia. Recommendations were developed based on this review using evidence-based methods. These recommendations were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the American Academy of Sleep Medicine. Psychological and behavioral interventions are effective in the treatment of both chronic primary insomnia (Standard) and secondary insomnia (Guideline). Stimulus control therapy, relaxation training, and cognitive behavior therapy are individually effective therapies in the treatment of chronic insomnia (Standard) and sleep restriction therapy, multicomponent therapy (without cognitive therapy), biofeedback and paradoxical intention are individually effective therapies in the treatment of chronic insomnia (Guideline). There was insufficient evidence to recommend sleep hygiene education, imagery training and cognitive therapy as single therapies or when added to other specific approaches. Psychological and behavioral interventions are effective in the treatment of insomnia in older adults and in the treatment of insomnia among chronic hypnotic users (Standard).

Adult↗

PubMed2005

Environmentally stratified sampling design for the development of Great Lakes environmental indicators.

Understanding the relationship between human disturbance and ecological response is essential to the process of indicator development. For large-scale observational studies, sites should be selected across gradients of anthropogenic stress, but such gradients are often unknown for apopulation of sites prior to site selection. Stress data available from public sources can be used in a geographic information system (GIS) to partially characterize environmental conditions for large geographic areas without visiting the sites. We divided the U.S. Great Lakes coastal region into 762 units consisting of a shoreline reach and drainage-shed and then summarized over 200 environmental variables in seven categories for the units using a GIS. Redundancy within the categories of environmental variables was reduced using principal components analysis. Environmental strata were generated from cluster analysis using principal component scores as input. To protect against site selection bias, sites were selected in random order from clusters. The site selection process allowed us to exclude sites that were inaccessible and was shown to successfully distribute sites across the range of environmental variation in our GIS data. This design has broad applicability when the goal is to develop ecological indicators using observational data from large-scale surveys.

Animals↗

PubMed2005

Aging and caloric restriction: effects on Leydig cell steroidogenesis.

We have shown previously that testosterone concentration in the blood serum of Brown Norway rat becomes reduced with aging, and that this results from reduced testosterone production by individual Leydig cells. Herein we examine the effects of caloric restriction (CR), an intervention shown to delay or inhibit age-associated pathologic and biologic changes in a number of systems and organisms, on Leydig cell steroidogenic function. CR (40%) was initiated in 4 month-old Brown Norway rats, and continued through age 34 months. Serum testosterone concentration in the ad libitum (AL)-fed controls was reduced by 30% from 5 to 13 months, by another 67% through 25 months, and then was sustained through 34 months. For the CR rats, the serum testosterone level was reduced to 45% of AL controls by 5 months, only 6 weeks after the initiation of the CR regimen. There was no further reduction through 25 months, at which time serum testosterone concentration in CR animals was significantly higher than in AL controls. By age 28-34 months, there was no significant difference between the two diets. The weights of prostate and seminal vesicle, two biomarkers of serum androgen levels, were consistent with the changes in serum testosterone concentration in both AL and CR animals. The ability of isolated Leydig cells to produce testosterone in vitro also paralleled the age- and CR-related changes in serum testosterone concentration. CR resulted in a rapid, 36% reduction in testosterone production from control by age 5 months. In contrast to cells from the AL rats, there were no further decreases in testosterone production through age 25 months. Indeed, Leydig cells from the 25 month-old CR rats produced significantly greater amounts of testosterone than cells from the 25 month-old AL rats. These results indicate that short-term CR results in the suppression of Leydig cell function and in reduction in serum testosterone levels. The significantly higher concentrations of serum testosterone concentration, and increased Leydig cell testosterone production, elicited by CR in 25 month-old rats compared to AL controls suggest that long-term CR can transiently suppress the reductions in steroidogenesis that are characteristic of aging.

Aging↗

PubMed2005

Pilot study of Myers Briggs Type Indicator personality profiling in emergency department senior medical staff.

OBJECTIVE: To study the viability of using the Myers Briggs Type Indicator (MBTI) in senior ED medical staff and to examine what trends, if any, in personality types exist within the specialty. METHODS: A pilot cross-sectional survey was undertaken during which a standard MBTI questionnaire was sent anonymously to a convenience sample of senior ED medical staff in Tasmania and South Australia. Completed surveys after a second mailing were analysed and the results collated. RESULTS: Of 82 senior ED medical staff surveyed, 68 returned completed questionnaires (response rate 83%). The single most common personality group in the cohort was the (Extrovert/Intuitive/Thinking/Judging) ENTJ type exhibited by 12 (17.7%, 95% CI 9.4-28.7%) clinicians in the cohort. This group is present at a rate of 3% in the general population. In terms of individual traits, Introversion was exhibited by 33 (48.5%, 95% CI 36.2-61%), Intuitive traits by 40 (58.8%, 95% CI 46.2-70.6%), Thinking traits by 40 (58.8%, 95% CI 46.2-70.6%) and Judging traits by 53 (77.9%, 95% CI 66.2-87.1%) of our cohort of senior ED medical staff. CONCLUSION: Our senior ED medical staff cohort suggests notable variations from the general population in terms of their MBTI profiles.

Cross-Sectional Studies↗

PubMed2005

Teaching on the run--general practice training between consultations.

BACKGROUND: General practitioner teachers play a growing role in medical education. Much of the teaching is done during and between patient consultations, ie. 'on the run'. This presents challenges in terms of time available for teaching, teacher training and feedback on teacher performance. Australian Government funded programs have been developed to train clinical teachers in hospital settings; these might be adaptable to the general practice setting. OBJECTIVE: This article describes a project aimed to adapt current programs to the needs of GP teachers, and present them in workshops around Tasmania. DISCUSSION: The adapted program was well received by workshop participants, who reported significant increase in knowledge and skill in teaching, and a change in attitude to teaching in their practices. The program will be continued and expanded to encourage more GPs, general practice registrars and senior medical students to teach on the run.

Australia↗

PubMed2004

The cyclooxygenase-2 inhibitor GW406381X [2-(4-ethoxyphenyl)-3-[4-(methylsulfonyl)phenyl]-pyrazolo[1,5-b]pyridazine] is effective in animal models of neuropathic pain and central sensitization.

The pathogenic form of the cyclooxygenase (COX) enzyme, COX-2, is also constitutively present in the spinal cord and has been implicated in chronic pain states in rat and man. A number of COX-2 inhibitors, including celecoxib and rofecoxib, are already used in man for the treatment of inflammatory pain. Preclinically, the dual-acting COX-2 inhibitor, GW406381X [2-(4-ethoxyphenyl)-3-[4-(methylsulfonyl)phenyl]-pyrazolo[1,5-b]pyridazine, where X denotes the free base], is as effective as rofecoxib and celecoxib in the rat established Freund's Complete Adjuvant model with an ED(50) of 1.5 mg/kg p.o. compared with 1.0 mg/kg p.o. for rofecoxib and 6.6 mg/kg p.o. for celecoxib. However, in contrast to celecoxib (5 mg/kg p.o. b.i.d.) and rofecoxib (5 mg/kg p.o. b.i.d.), which were without significant effect, GW406381X (5 mg/kg p.o. b.i.d.) fully reversed mechanical allodynia in the chronic constriction injury model and reversed thermal hyperalgesia in the mouse partial ligation model, both models of neuropathic pain. GW406381X, was also effective in a rat model of capsaicin-induced central sensitization, when given intrathecally (ED(50) = 0.07 mug) and after chronic but not acute oral dosing. Celecoxib and rofecoxib had no effect in this model. Several hypotheses have been proposed to try to explain these differences in efficacy, including central nervous system penetration, enzyme kinetics, and potency. The novel finding of effectiveness of GW406381X in these models of neuropathic pain/central sensitization, in addition to activity in inflammatory pain models and together with its central efficacy, suggests dual activity of GW406381X compared with celecoxib and rofecoxib, which may translate into greater efficacy in a broader spectrum of pain states in the clinic.

Animals↗

PubMed2004

Identification of 2,3-diaryl-pyrazolo[1,5-b]pyridazines as potent and selective cyclooxygenase-2 inhibitors.

GW406381 (8), currently undergoing clinical evaluation for the treatment of inflammatory pain is a member of a novel series of 2,3-diaryl-pyrazolo[1,5-b]pyridazine based cyclooxygenase-2 (COX-2) inhibitors, which have been shown to be highly potent and selective. Several examples of the series, in addition to possessing favourable pharmacokinetic profiles and analgesic activity in vivo, have also demonstrated relatively high brain penetration in the rat compared with the clinically available compounds, which may ultimately prove beneficial in the treatment of pain.

Administration, Oral↗

PubMed2004

Recent developments in low-level lead exposure and intellectual impairment in children.

In the last decade children's blood lead levels have fallen significantly in a number of countries, and current mean levels in developed countries are in the region of 3 Mu g/dL. Despite this reduction, childhood lead poisoning continues to be a major public health problem for certain at-risk groups of children, and concerns remain over the effects of lead on intellectual development in infants and children. The evidence for lowered cognitive ability in children exposed to lead has come largely from prospective epidemiologic studies. The current World Health Organization/Centers for Disease Control and Prevention blood level of concern reflects this and stands at 10 Mu g/dL. However, a recent study on a cohort of children whose lifetime peak blood levels were consistently less than 10 Mu g/dL has extended the association of blood lead and intellectual impairment to lower levels of lead exposure and suggests there is no safety margin at existing exposures. Because of the importance of this finding, we reviewed this study in detail along with other recent developments in the field of low-level lead exposure and children's cognitive development. We conclude that these findings are important scientifically, and efforts should continue to reduce childhood exposure. However, from a public health perspective, exposure to lead should be seen within the many other risk factors impacting on normal childhood development, in particular the influence of the learning environment itself. Current lead exposure accounts for a very small amount of variance in cognitive ability (1-4%), whereas social and parenting factors account for 40% or more.

Child↗

PubMed2002

Summary of the National Toxicology Program's report of the endocrine disruptors low-dose peer review.

At the request of the U.S. Environmental Protection Agency (U.S. EPA), the National Toxicology Program organized an independent and open peer review to evaluate the scientific evidence on low-dose effects and nonmonotonic dose-response relationships for endocrine-disrupting chemicals in mammalian species. For this peer review, "low-dose effects" referred to biologic changes that occur in the range of human exposures or at doses lower than those typically used in the standard testing paradigm of the U.S. EPA for evaluating reproductive and developmental toxicity. The demonstration that an effect is adverse was not required because in many cases the long-term health consequences of altered endocrine function during development have not been fully characterized. A unique aspect of this peer review was the willing submission of individual animal data by principal investigators of primary research groups active in this field and the independent statistical reanalyses of selected parameters prior to the peer review meeting by a subpanel of statisticians. The expert peer-review panel (the panel) also considered mechanistic data that might influence the plausibility of low-dose effects and identified study design issues or other biologic factors that might account for differences in reported outcomes among studies. The panel found that low-dose effects, as defined for this review, have been demonstrated in laboratory animals exposed to certain endocrine-active agents. In some cases where low-dose effects have been reported, the findings have not been replicated. The shape of the dose-response curves for reported effects varied with the end point and dosing regimen and were low-dose linear, threshold-appearing, or nonmonotonic. The findings of the panel indicate that the current testing paradigm used for assessments of reproductive and developmental toxicity should be revisited to see whether changes are needed regarding dose selection, animal-model selection, age when animals are evaluated, and the end points being measured following exposure to endocrine-active agents.

Androgens↗