A randomised controlled trial of the effects of mindfulness practice on medical student stress levels

OBJECTIVE

This study aimed to determine whether the practice of mindfulness reduces the level of stress experienced by senior medical students.

METHODS

We carried out a multicentre, single-blinded, randomised controlled trial with intention-to-treat analysis in three clinical schools attached to the University of Tasmania, Hobart, Tasmania. Participants included 66 medical students in their final 2 years of study in 2009. Participants were block-randomised to either an intervention or a usual care control group. The intervention used an audio CD of guided mindfulness practice designed and produced for this trial. Participants were advised to use the intervention daily over the 8 weeks of the trial. All participants completed two self-report questionnaires, at baseline and at 8 weeks, respectively. The intervention group also completed a questionnaire at 16 weeks to provide follow-up data. The primary outcome measure was the difference over time in scores on the Perceived Stress Scale (PSS). The secondary outcome measure referred to differences over time in scores on the subscales of the Depression, Anxiety and Stress Scale (DASS).

RESULTS

Mean baseline scores on the PSS and the stress component of the DASS were 15.7 (maximal score of 40) and 13.2 (maximal score of 42), respectively, both of which exceed scores in age-matched normative control data. Using multivariable analysis, participants in the intervention group demonstrated significant reductions in scores on the PSS (- 3.44, 95% confidence interval [CI] - 6.20 to - 0.68; p < 0.05) and the anxiety component of the DASS (- 2.82, 95% CI - 4.99 to - 0.64; p < 0.05). A borderline significant effect was demonstrated on the stress component of the DASS (- 3.69, 95% CI - 7.38 to 0.01; p = 0.05). Follow-up at 8 weeks post-trial revealed that the effect was maintained.

CONCLUSIONS

Mindfulness practice reduced stress and anxiety in senior medical students. Stress is prevalent in medical students and can have adverse effects on both student health and patients. A simple, self-administered, evidence-based intervention now exists to manage stress in this at-risk population and should be widely utilised.

A randomised controlled trial of the effects of mindfulness practice on medical student stress levels

OBJECTIVE

This study aimed to determine whether the practice of mindfulness reduces the level of stress experienced by senior medical students.

METHODS

We carried out a multicentre, single-blinded, randomised controlled trial with intention-to-treat analysis in three clinical schools attached to the University of Tasmania, Hobart, Tasmania. Participants included 66 medical students in their final 2 years of study in 2009. Participants were block-randomised to either an intervention or a usual care control group. The intervention used an audio CD of guided mindfulness practice designed and produced for this trial. Participants were advised to use the intervention daily over the 8 weeks of the trial. All participants completed two self-report questionnaires, at baseline and at 8 weeks, respectively. The intervention group also completed a questionnaire at 16 weeks to provide follow-up data. The primary outcome measure was the difference over time in scores on the Perceived Stress Scale (PSS). The secondary outcome measure referred to differences over time in scores on the subscales of the Depression, Anxiety and Stress Scale (DASS).

RESULTS

Mean baseline scores on the PSS and the stress component of the DASS were 15.7 (maximal score of 40) and 13.2 (maximal score of 42), respectively, both of which exceed scores in age-matched normative control data. Using multivariable analysis, participants in the intervention group demonstrated significant reductions in scores on the PSS (- 3.44, 95% confidence interval [CI] - 6.20 to - 0.68; p < 0.05) and the anxiety component of the DASS (- 2.82, 95% CI - 4.99 to - 0.64; p < 0.05). A borderline significant effect was demonstrated on the stress component of the DASS (- 3.69, 95% CI - 7.38 to 0.01; p = 0.05). Follow-up at 8 weeks post-trial revealed that the effect was maintained.

CONCLUSIONS

Mindfulness practice reduced stress and anxiety in senior medical students. Stress is prevalent in medical students and can have adverse effects on both student health and patients. A simple, self-administered, evidence-based intervention now exists to manage stress in this at-risk population and should be widely utilised.

PORRIGE - a cohort study of general practice registrars

BACKGROUND

Current general practitioner shortages need to be addressed, especially in areas of need. This study was designed to investigate which registrar characteristics were associated with retention in the field of general practice (and in the region of training).

METHOD

The authors performed a retrospective cohort study of people who entered general practice training in Tasmania from 1995-2005, and included a crosssectional survey conducted between November 2008 and April 2009 that assessed the association between baseline characteristics and current field of practice and practice location.

RESULTS

Fifty-four percent of the cohort was working in general practice in Tasmania at the time of the survey. General practice registrars were more likely to be a GP working in Tasmania if they were nonmedically partnered (OR 14.42, p=0.001). They were also more likely to be living in Tasmania if they were older (OR 1.47, p=0.029) or nonmedically partnered (OR 23.4, p=0.014).

DISCUSSION

Regional training providers may best be able to serve their training region by addressing the specific needs of the general practice registrar family unit.

Bone marrow lesions predict site-specific cartilage defect development and volume loss: a prospective study in older adults

Introduction

Recent evidence suggests that bone marrow lesions (BMLs) play a pivotal role in knee osteoarthritis (OA). The aims of this study were to determine: 1) whether baseline BML presence and/or severity predict site-specific cartilage defect progression and cartilage volume loss; and 2) whether baseline cartilage defects predict site-specific BML progression.

Methods

A total of 405 subjects (mean age 63 years, range 52 to 79) were measured at baseline and approximately 2.7 years later. Magnetic resonance imaging (MRI) of the right knee was performed to measure knee cartilage volume, cartilage defects (0 to 4), and BMLs (0 to 3) at the medial tibial (MT), medial femoral (MF), lateral tibial (LT), and lateral femoral (LF) sites. Logistic regression and generalized estimating equations were used to examine the relationship between BMLs and cartilage defects and cartilage volume loss.

Results

At all four sites, baseline BML presence predicted defect progression (odds ratio (OR) 2.4 to 6.4, all P < 0.05), and cartilage volume loss (-0.9 to -2.9% difference per annum, all P < 0.05) at the same site. In multivariable analysis, there was a significant relationship between BML severity and defect progression at all four sites (OR 1.8 to 3.2, all P < 0.05) and BML severity and cartilage volume loss at the MF, LT, and LF sites (β -22.1 to -42.0, all P < 0.05). Additionally, baseline defect severity predicted BML progression at the MT and LF sites (OR 3.3 to 3.7, all P < 0.01). Lastly, there was a greater increase in cartilage volume loss at the MT and LT sites when both larger defects and BMLs were present at baseline (all P < 0.05).

Conclusions

Baseline BMLs predicted site-specific defect progression and cartilage volume loss in a dose-response manner suggesting BMLs may have a local effect on cartilage homeostasis. Baseline defects predicted site-specific BML progression, which may represent increased bone loading adjacent to defects. These results suggest BMLs and defects are interconnected and play key roles in knee cartilage volume loss; thus, both should be considered targets for intervention.

Natural history and clinical significance of MRI-detected bone marrow lesions at the knee: a prospective study in community dwelling older adults

Introduction

There are conflicting data on the natural history and clinical significance of bone marrow lesions (BMLs). The aims of this study were to describe the natural history of MRI-detected BMLs at the knee using a quantitative measure and examine the association of BMLs with pain, function and stiffness scores, and total knee replacement (TKR) surgery.

Methods

A total of 395 older males and females were randomly selected from the general population (mean age 63 years, range 52 to 79) and measured at baseline and approximately 2.7 years later. BMLs were determined using T2-weighted fat saturation MRI by measuring the maximum area of the lesion. Reproducibility was excellent (intraclass correlation coefficient (ICC): 0.97). Pain, function, and stiffness were assessed by Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores. X-ray was used to assess radiographic osteoarthritis (ROA) at baseline.

Results

At baseline, 43% (n = 168/395) had a BML. Of these 25% decreased in size and 24% increased. Of the remaining sample (n = 227), 7% developed a new BML. In a multivariable model, a change in BML size was associated with a change in pain and function scores (β = 1.13 to 2.55 per 1 SD increase, all P < 0.05), only in those participants without ROA. Lastly, baseline BML severity predicted TKR surgery (odds ratio (OR) 2.10/unit, P = 0.019).

Conclusions

In a population based sample, BMLs (assessed by measuring maximal area) were not static, with similar proportions both worsening and improving. A change in BML size was associated with changes in pain in those without established ROA. This finding suggests that fluctuating knee pain may be attributable to BMLs in those participants with early stage disease. Baseline BMLs also predicted TKR surgery. These findings suggest therapeutic interventions aimed at altering the natural history of BMLs should be considered.

Pedometer determined ambulatory activity and bone mass: a population-based longitudinal study in older adults

In this large population-based study, walking was assessed twice yearly for a week, each time by pedometer, had consistent clinically important associations with hip areal bone mineral density (aBMD) in both sexes which appears most important in those over 65 years of age suggesting that walking becomes more important with increasing age.

INTRODUCTION

Walking is advocated as a preventative strategy for osteoporosis but the evidence is conflicting in females and lacking in males. The aim of this population-based longitudinal study in community dwelling older people (n=875) was to determine the association between pedometer determined ambulatory activity (PAA) and bone mass.

METHODS

Bone mass was assessed as aBMD at the hip and spine using dual X-ray absorptiometry. Steps per day were measured using pedometers for 1 week on four occasions at least 6 months apart. Data were analysed using linear mixed models.

RESULTS

At baseline, PAA was positively associated with hip aBMD. An age interaction was present with steps having a stronger association for those aged over 65 years. Longitudinally, the effect of steps on hip aBMD was constant, but not additive over time. For those over 65 years, the difference in hip aBMD between the lowest and highest steps quartiles ranged from 3.1% to 9.4%. With regard to the spine, the relationship between daily steps and spine aBMD was modified by sex. For males; there was no significant relationship between steps and spine aBMD. However, for females, higher steps were associated with higher spine aBMD with the effect being constant over time but not additive. There was no evidence of a threshold effect.

CONCLUSION

In conclusion, pedometer-determined ambulatory activity has consistent clinically important associations with hip aBMD in both sexes which appears most important in those over 65 years of age. The associations for spine aBMD were both weaker and inconsistent suggesting site specificity.

Subchondral bone and cartilage damage: a prospective study in older adults

OBJECTIVE

There is limited longitudinal evidence relating subchondral bone changes to cartilage damage and loss. The aim of this study was to describe the association between baseline tibial bone area and tibial subchondral bone mineral density (BMD) with tibial cartilage defect development and cartilage volume loss.

METHODS

A total of 341 subjects (mean age 63 years, range 52-79 years) underwent measurement at baseline and approximately 2.7 years later. Tibial knee cartilage volume, cartilage defects (graded on a scale of 0-4), and bone area were determined using T1-weighted fat suppression magnetic resonance imaging. Tibial subchondral BMD was determined using dual x-ray absorptiometry.

RESULTS

In multivariable analysis, baseline bone area positively predicted cartilage defect development at the medial and lateral tibial sites (odds ratio [OR] 1.6 per 1 SD increase, 95% confidence interval [95% CI] 1.0, 2.6, and OR 2.4 per 1 SD increase, 95% CI 1.4, 4.0, respectively) and cartilage volume loss at the medial tibial site (beta = -34.9 per 1 SD increase, 95% CI -49.8, -20.1). In contrast, baseline subchondral BMD positively predicted cartilage defect development at the medial tibial site only (OR 1.6 per 1 SD increase, 95% CI 1.2, 2.1) and was not associated with cartilage loss.

CONCLUSION

The results of this study demonstrated that bone area predicted medial and lateral cartilage defect development and medial cartilage volume loss, while subchondral BMD predicted medial defect development but not cartilage loss. These associations were independent of each other, indicating there are multiple mechanisms by which subchondral bone changes may lead to cartilage damage.

General practitioners' use of cardiovascular risk calculators

BACKGROUND

This study was designed to investigate general practitioners' knowledge of absolute risk estimation, and whether they used it to guide their management of cardiovascular disease.

METHOD

A cross sectional postal self administered survey of GPs in the General Practice South Division in southern Tasmania.

RESULTS

A total of 56-62% of responders correctly answered knowledge questions, which could be as low as 33-36% when corrected for nonresponse bias. A cardiovascular risk calculator was used by 72% (as low as 42% when corrected for nonresponse bias); of these, 93% used them to motivate lifestyle change and for education, and 66% used them to assist disease management. General practitioners who used risk calculators tended to rate some factors more highly as contributing to cardiovascular disease, such as Aboriginality and diabetes.

DISCUSSION

Many GPs were using absolute risk calculators, and most used them appropriately as decision making tools, not just for education or motivation. Further education of GPs about cardiovascular risk is still indicated.

A randomized single blind crossover trial comparing leather and commercial wrist splints for treating chronic wrist pain in adults

BACKGROUND

To compare the effectiveness of a custom-made leather wrist splint (LS) with a commercially available fabric splint (FS) in adults with chronic wrist pain.

METHODS

Participants (N = 25, mean age = 54) were randomly assigned to treatment order in a 2-phase crossover trial. Splints were worn for 2 weeks, separated by a one-week washout period. Outcomes were assessed at baseline and after each splint phase using the Australian/Canadian Osteoarthritis Hand Index (AUSCAN), the Canadian Occupational Performance Measure (COPM) and Jamar dynamometer by an observer blinded to treatment allocation.

RESULTS

Both styles of wrist splint significantly reduced pain (effect size LS 0.79, FS 0.43), improved hand function and increased grip strength compared to baseline (all p < 0.05) with no increase in wrist stiffness. There was a consistent trend for the LS to be superior to the FS but this was statistically significant only for patient perceived occupational performance (p = 0.008) and satisfaction (p = 0.015). Lastly, 72% of patients preferred the custom-made leather splint compared to the commercially available splint.

CONCLUSION

Leather wrist splints were superior to a commercially available fabric splint for the short-term relief of pain and dysfunction.

Clinically isolated acute transverse myelitis: prognostic features and incidence

Demyelinating acute transverse myelitis may be the first presentation of multiple sclerosis or remain a clinically isolated syndrome. North Canterbury, New Zealand provides a well circumscribed population to study acute transverse myelitis. Objective: to identify prognostic features, clinical outcomes and incidence of ATM in North Canterbury, New Zealand. All patients with acute transverse myelitis as a first neurological presentation diagnosed from January 2001 to December 2005 at a single institution providing all neurological care for North Canterbury were assessed for clinical data, MRI findings, cerebrospinal fluid results and clinical outcomes. CHAMPS, Barkhof/Tintore and Swanton criteria were applied to brain MRI. Sixty-one patients were identified with a mean duration of follow-up of 30 ± 17 months. Fifty percent of patients with ATM with brain lesions by CHAMPS criteria converted to clinically definite multiple sclerosis. No patients with idiopathic acute transverse myelitis converted to clinically definite multiple sclerosis. There was a strong association with conversion to clinically definite multiple sclerosis and abnormal brain MRI by CHAMPS criteria (hazard ratio, 5.63; 1.83—17.3), Barkhof/Tintore criteria (hazard ratio, 6.43; 2.31—17.9) and Swanton criteria (hazard ratio, 4.53; 1.67—12.3). The age standardized annual incidence of acute transverse myelitis was 24.6 (18.2—31.1) per million, of definite and possible idiopathic acute transverse myelitis was 6.2 (2.9—9.6) per million, and of acute transverse myelitis with brain lesions was 4.7 (1.9—7.6) per million. Patients with idiopathic acute transverse myelitis are at low risk for conversion to clinically definite multiple sclerosis. Abnormal brain MRI by CHAMPS criteria is a sensitive predictor of conversion to clinically definite multiple sclerosis. The annual incidence of acute transverse multiple sclerosis in North Canterbury, New Zealand is significantly higher than previously reported.

Growing rate of gain on subsequent feedlot performance, meat, and carcass quality of beef steers

Eighty Angus and Angus x Simmental steer calves were used in a completely random design to determine the effect of rate of BW gain during the backgrounding period on subsequent feedlot performance, carcass characteristics, Warner-Bratzler shear force (WBSF), and sensory analysis. Animals were stratified by BW and allotted randomly to 1 of 10 pens (5 pens/treatment). Dietary treatments were formulated for an ADG of 0.91 kg/d [low BW gain (LG), 1.06 Mcal of NE(g)/kg] diets and 1.25 kg/d [high BW gain (HG), 1.19 Mcal of NE(g)/kg]. Steers were fed 70 d during the growing period. The LG diet consisted of 52.5% barley silage, 39.0% whole shell corn, and 8.5% supplement, whereas the HG diet contained 43.9% barley silage, 47.4% whole shell corn, and 8.7% supplement (DM basis). Initial BW (226 kg) was not different (P = 0.70) between treatments. Steers fed the HG diet had increased ADG (1.67 vs. 1.40 kg/d; P < 0.001) compared with steers fed LG diet. Dry matter intake was greater (9.49 vs. 8.35 kg/d; P < 0.001) for steers fed the HG vs. LG diet. Total backgrounding cost ($/animal) was less (P < 0.001) for those steers fed LG diet compared with HG diet ($126.00 vs. $140.35, respectively); however, total cost per kilogram of BW gain was not different (P = 0.24; $0.485/kg of BW gain). After the backgrounding period, steers were fed a common finishing diet for 135 d. During the finishing period, LG steers had similar (P = 0.12; 10.73 vs. 10.35 kg/d) DMI compared with those fed HG diets; however, ADG was not different (1.55 kg; P = 0.72) among treatments. Hot carcass weight, marbling score, 12th-rib fat, LM area, and USDA yield grade were not different (P > 0.12) between treatments and averaged 363 kg, Sm(30), 1.33 cm, 83.8 cm(2), and 2.7, respectively. There were no differences (P = 0.77; 3.63 +/- 0.12 kg) in WBSF tenderness of rib-eye steaks. Percent cooking loss was increased in LG diets (P = 0.017). No differences were observed in consumer sensory analysis of tenderness, juiciness, and flavor intensity (P > or = 0.276; 5.43 +/- 0.12, 5.07 +/- 0.13, and 5.17 +/- 0.05, respectively). These data suggest that feeding steers diets that differ in energy concentration and result in ADG of 1.4 and 1.7 kg/d during the growing period results in minimal changes in subsequent finishing performance and does not affect meat quality.

Tracking of bone mass from childhood to adolescence and factors that predict deviation from tracking

It has been hypothesized that bone density tracks but long term studies in children are lacking. As such, the aim of this study was to describe tracking of dual X-ray absorptiometry measures from age 8 to age 16 years, whether this was independent of change in body size and whether deviation from tracking could be predicted. 116 males and 67 females had anthropometric (height and weight), questionnaire (medication use, sports, breastfeeding), fitness (PWC(170)) and DXA measures (bone free lean mass [LM], fat mass [FM] and bone mass) at baseline and follow-up. BMC and aBMD were assessed at the spine and hip and total body and bone mineral apparent density (BMAD) at the spine and hip. We found all DXA measures tracked significantly after adjustment for change in height and change in weight (males: R(2): BMC 24-62%; aBMD 41-48%; BMAD 30-37%, females: R(2): BMC 45-72%; aBMD 36-56%; BMAD 30-48%). Factors that predicted subjects would deviate positively, that is improve in tertile or remain in the highest tertile of spine and hip aBMD included having been breastfed, increase in LM, PWC(170) at age 8 and sport participation in males. LM at age 8 was beneficial in males while in females; FM at age 8 predicted subjects would deviate positively. Boys who gained absolute and percent FM and girls who gained percent FM, were more likely to deviate negatively, that is, decrease in tertile or remain in the lowest tertile of spine and hip aBMD. ICS use at age 8 also predicted subjects, particularly males would not improve in bone mass relative to their peers. In conclusion, DXA measures track moderately to strongly from childhood to adolescence. This was independent of linear growth and sex indicating bone development and physical growth are under largely separate mechanistic control. Body composition was the main predictor of altered tracking but environmental factors also appear important.

Increasing incidence of ALS in Canterbury, New Zealand: a 22-year study

OBJECTIVE

We performed a prospective study of amyotrophic lateral sclerosis (ALS) in North Canterbury, New Zealand, from 1985 to 2006, to ascertain the incidence of ALS over that 22-year period, and to detect patterns of change in incidence. We also aimed to identify factors that influenced survival.

METHODS

A prospective database of all patients seen at the Department of Neurology at Christchurch Public Hospital formed the basis of this study. Additional cases were identified through hospital coding data and from neurologists' private practice records. Kaplan-Meier life table analysis and Cox proportional hazards analyses were used for the survival analysis. Poisson regression and capture-recapture techniques were used to analyze incidence data.

RESULTS

ALS incidence rates steadily increased by 3% per year over the 22 years, from 1.6 to 3.3 per 100,000 per year. Older age, bulbar symptoms, and male sex adversely affected survival. The median survival from diagnosis was 17.6 months and from symptom onset 27.6 months. Contemporary supportive therapies such as noninvasive ventilation and percutaneous endoscopic gastrostomy did not extend survival. There was no disease clustering and no clues to etiology were revealed.

CONCLUSIONS

We report the highest recorded incidence of amyotrophic lateral sclerosis (ALS) to date, with the incidence of ALS in Canterbury increasing over the 22 years of the study. We were unable to confirm improvement in survival using contemporary supportive therapies and confirmed older age, male sex, and bulbar onset as adverse prognostic factors. The increasing incidence is not explained by aging of the population.

Identification of a prostate cancer susceptibility gene on chromosome 5p13q12 associated with risk of both familial and sporadic disease

Genetic heterogeneity is a difficulty frequently encountered in the search for genes conferring susceptibility to prostate cancer. To circumvent this issue, we selected a large prostate cancer pedigree for genome-wide linkage analysis from a population that is genetically homogeneous. Selected cases and first-degree relatives were genotyped with Affymetrix 10K SNP arrays, identifying a 14 Mb haplotype on chromosome 5 (5p13-q12) inherited identical-by-descent (IBD) by multiple cases. Microsatellite genotyping of additional deceased case samples confirmed that a total of eight cases inherited the common haplotype (P=0.0017). Re-sequencing of eight prioritised candidate genes in the region in six selected individuals identified 15 SNPs segregating with the IBD haplotype, located within the ITGA2 gene. Three of these polymorphisms were selected for genotyping in an independent Tasmanian data set comprising 127 cases with familial prostate cancer, 412 sporadic cases and 319 unaffected controls. Two were associated with prostate cancer risk: rs3212649 (OR=1.67 (1.07-2.6), P=0.0009) and rs1126643 (OR=1.52 (1.01-2.28), P=0.0088). Significant association was observed in both familial and sporadic prostate cancer. Although the functional SNP remains to be identified, considerable circumstantial evidence, provided by in vivo and in vitro studies, supports a role for ITGA2 in tumour development.

Association between birth weight and adolescent systolic blood pressure in a caucasian birth cohort differs according to skin type, CRH promoter or 11beta-HSD2 genotype

OBJECTIVE

To examine whether the inverse association between birth weight and blood pressure varies by skin pigmentation and/or related genotypes.

STUDY DESIGN

671 children from a predominantly caucasian birth cohort were followed-up to adolescence (mean (SD) age 14.4 (0.64)).

METHODS

Data on birth weight, socioeconomic status, maternal antenatal smoking, adolescent blood pressure and polymorphisms of candidate genes were obtained and analysed by multiple linear regression.

RESULTS

An increase in birth weight of 1 kg was associated with an non-significant difference in adolescent systolic blood pressure of -0.53 mm Hg (95% CI -1.72 to 0.66) per kg after adjustment for child age and cohort entry criteria. The inverse association between birth weight and systolic blood pressure was stronger for those with darker skin (> or =2% melanin) (difference in effect, p = 0.02), those with more copies of the C allele of corticotropin-releasing hormone (CRH) +T1273C (p = 0.06), and those with more copies of the short (< or =236 bp) form of the 11beta-HSD2{CA}n(repeat) microsatellite (p = 0.03).

CONCLUSIONS

These findings add to the evidence that cortisol-related pathways may account for at least part of the observed birth weight-blood pressure associations.

A Meta-Analysis of the Effect of Time Pressure on Human Performance

A quantitative review of time pressure effects on human performance was conducted. One-hundred-twenty-five references were identified that met selection criteria. These studies provided 827 effect sizes. Analyses revealed an overall small but detrimental effect of time pressure on performance. However, moderator analyses indicated that the effect of time pressure varied as a function of task type and the measure of performance (accuracy vs. speed). As expected, time pressure facilitated speed but impaired accuracy for both perceptual and cognitive tasks. Although there were few studies available for motor tasks, evidence from the available studies indicated that time pressure reduced speed. Accuracy data were inconclusive. Across all analyses there was evidence of substantial variability across studies, indicating that other moderating variables may influence the performance effects of time pressure.

Cardiomyopathy and cardiomegaly in stillborn infants of diabetic mothers

To report the incidence of cardiomegaly in stillborn normally formed infants of mothers with diabetes mellitus. This is a retrospective study with institutional ethics approval. The presence of cardiomegaly was recorded in stillborn infants of diabetic mothers (N = 27) and compared with that recorded in stillborn large-for-gestational age (LGA > 90th percentile, n = 18) and stillborn appropriately grown (10th to 90th percentiles, n = 107) nondiabetic infants. Blinded to the clinical details, the histology slides were reviewed to measure cardiac wall thickness and to record the presence or absence of myocardial fiber disarray. Stillborn infants of mothers with diabetes mellitus, when compared with appropriately grown stillborn nondiabetic infants and when adjusted for birth weight, had heavier hearts, thicker ventricular free wall measurements, and lighter brains. While cardiomegaly was reported in 22% of stillborn LGA infants, comparison with stillborn appropriately grown infants revealed no difference in heart weights corrected for birth weight. Comparison of LGA nondiabetic infants with stillborn diabetes mellitus infants revealed greater actual heart weight/expected for birth weight (P < 0.05) and lighter brains (actual brain weight/expected for birth weight, P < 0.05) in the diabetes mellitus group. Cardiomegaly is a common finding in stillborn infants of mothers with diabetes mellitus and may contribute to the risk of fetal death in these pregnancies.

The advantages of dense marker sets for linkage analysis with very large families

Dense sets of hundreds of thousands of markers have been developed for genome-wide association studies. These marker sets are also beneficial for linkage analysis of large, deep pedigrees containing distantly related cases. It is impossible to analyse jointly all genotypes in large pedigrees using the Lander-Green Algorithm, however, as marker density increases it becomes less crucial to analyse all individuals' genotypes simultaneously. In this report, an approximate multipoint non-parametric technique is described, where large pedigrees are split into many small pedigrees, each containing just two cases. This technique is demonstrated, using phased data from the International Hapmap Project to simulate sets of 10,000, 50,000 and 250,000 markers, showing that it becomes increasingly accurate as more markers are genotyped. This method allows routine linkage analysis of large families with dense marker sets and represents a more easily applied alternative to Monte Carlo Markov Chain methods.

Natural history of the long-term cognitive, affective, and physical sequelae of mild traumatic brain injury

Mild traumatic brain injury (MTBI) is associated with cognitive,affective, and physical sequelae. When symptoms persist for more than 3 months, a diagnosis of Post-Concussion Syndrome (PCS) is often given. The current study tracked symptom development to explore the natural sequelae of MTBI. Twenty-six MTBI patients received a comprehensive neuropsychological assessment at three intervals: within 1 week, at 4 months and at 7 months post-concussion. Based on DSMIV criteria and clinical judgment, two external raters diagnosed five MTBI participants with PCS. Results suggested that aspects of cognitive functioning of the symptomatic MTBI (i.e., PCS) participants were different from matched normal control (NC) subjects, and from the 21 MTBI patients who were asymptomatic, at 4 months. Asymptomatic MTBI participants improved in overall level of functioning from 4 to 7 months, but remained significantly different from NC participants in their reduced verbal fluency and working memory functioning.

Proton transfer reaction of a new orthohydroxy Schiff base at room temperature and 77 K

One new orthohydroxy Schiff base, 2-(N-benzyl-alpha-iminoethyl)naphthol (BEIN) has been synthesized. The proton transfer reaction of BEIN has been investigated by means of absorption, steady state and time resolved fluorescence spectroscopy in different solvents at room temperature and 77K. The behavior of BEIN in ethanol and water, has been studied in neutral, acidic and basic conditions. Excited state intramolecular proton transfer (ESIPT) is evidenced by a large Stokes shifted ( approximately 11,000 cm-1) fluorescence in solid crystalline media at room temperature. We present the observation of phosphorescence both in non-polar and protic solvents at 77K. The observed decay dynamics of the phosphorescence and delayed fluorescence indicates that the triplet state can be attributed to the cis-keto form. The molecular structures are determined by B3LYP/6-31G** calculation. From theoretical study it is suggested that the strengthening of hydrogen bond result from the steric repulsion of the phenyl ring. The presence of benzene ring increases the proton transfer barrier in case of BEIN compared to previously studied 7-ethylsalicylidenebenzylamine (ESBA).

Doxazosin controlled release vs tamsulosin in the management of benign prostatic hyperplasia: an efficacy analysis

An analysis is presented to compare the efficacies of the doxazosin gastrointestinal therapeutic system (doxazosin-GITS) and tamsulosin in patients with benign prostatic hyperplasia (BPH), collecting data from a published 20-week, randomized, double-blind, crossover study. Results demonstrated that after 8 weeks of treatment, both doxazosin-GITS and tamsulosin provided significant (p < 0.001) improvement from baseline in total international prostate symptom score (IPSS) and obstructive and irritative subscores. Doxazosin-GITS was more effective than tamsulosin (p = 0.019 between-group difference for total IPSS; p = 0.001 for irritative subscore). Similarly, after the first 4 weeks of treatment, prior to dose titration, both doxazosin-GITS and tamsulosin provided significant (p < or = 0.001) improvement in total IPSS and subscores. Doxazosin-GITS was more effective than tamsulosin (p = 0.045 between-group difference for obstructive subscore). These data confirm that the efficacy of doxazosin is superior to that of tamsulosin in the management of patients with BPH.

Calcium-sensing receptor stimulates PTHrP release by pathways dependent on PKC, p38 MAPK, JNK, and ERK1/2 in H-500 cells

Elevated extracellular calcium ([Ca2+]o) and other agonists potentially acting via the calcium-sensing receptor (CaR) increase parathyroid hormone-related peptide (PTHrP) release from H-500 Leydig cells. Here, we provide strong evidence for the CaR's involvement by using a dominant negative CaR that attenuates high [Ca2+]o-induced PTHrP release. This effect is likely transcriptional, because high [Ca2+]o upregulates the PTHrP transcript, an effect that is abolished by actinomycin D. Regulation of PTHrP release by the CaR involves activation of PKC as well as ERK1/2, p38 MAPK, and JNK pathways. However, we show for the first time that high [Ca2+]o-induced activation of the stress-activated protein kinase SEK1 is PKC independent, because there is an additive effect of a PKC inhibitor in combination with the JNK inhibitor on [Ca2+]o-stimulated PTHrP release. Furthermore, high [Ca2+]o, in a PKC-independent fashion, induces phosphorylation of ERK1/2, SEK1, p38 MAPK, and its downstream transcription factor ATF-2. We conclude that CaR regulation of PTHrP release in H-500 cells involves activation of PKC as well as the ERK1/2, p38 MAPK, and JNK pathways.

Role of cyclooxygenase and haemoxygenase products in nitric oxide-independent vasodilatation in the porcine ciliary artery

PURPOSE

Vascular endothelial cell dysfunction has been noted in patients with normal pressure glaucoma. Although nitric oxide (NO) accounts for a large proportion of vasorelaxation in the posterior ciliary artery, considerable relaxation remains unexplained. We investigated the roles of haemoxygenase (HO) and cyclooxygenase (COX), which produce the vasodilators carbon monoxide (CO) and prostacyclin, respectively, in NO-independent endothelium-dependent vasodilatation in porcine posterior ciliary arteries.

METHODS

Isolated vascular rings were mounted in a Mulvaney-Halpern small vessel myograph for the measurement of isometric tension development. Vasodilator responses to bradykinin (BK) were elicited in each ring on three separate occasions following preconstriction with prostaglandin F(2alpha): first in the absence of inhibitors, second in the presence of the NO synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME, 10(-3) M), and third in the presence of L-NAME and either a COX (indomethacin, 10(-6) M) or an HO inhibitor (tin protoporphyrin-IX 10(-5) M). Results were expressed as a percentage of the maximal relaxation in the presence of L-NAME alone.

RESULTS

Incubation with indomethacin (n=6), in the presence of L-NAME, significantly reduced (P<0.01) maximum BK-induced relaxation (-103.5+/-8.8%) compared to paired rings in the presence of L-NAME alone (-130.8+/-8.8%). HO inhibition did not reduce NO-independent, BK-induced relaxation when compared to paired control vessels.

CONCLUSIONS

These data suggest that in the presence of L-NAME, a COX product accounts for a significant proportion of NO-independent vasodilatation. In contrast, endogenous CO production does not have a functionally significant role in the porcine ciliary artery. Eye (2003) 17, 628-636. doi:10.1038/sj.eye.6700437

Polyvalent cation receptor proteins (CaRs) are salinity sensors in fish

To determine whether calcium polyvalent cation-sensing receptors (CaRs) are salinity sensors in fish, we used a homology-based cloning strategy to isolate a 4.1-kb cDNA encoding a 1,027-aa dogfish shark (Squalus acanthias) kidney CaR. Expression studies in human embryonic kidney cells reveal that shark kidney senses combinations of Ca(2+), Mg(2+), and Na(+) ions at concentrations present in seawater and kidney tubules. Shark kidney is expressed in multiple shark osmoregulatory organs, including specific tubules of the kidney, rectal gland, stomach, intestine, olfactory lamellae, gill, and brain. Reverse transcriptase-PCR amplification using specific primers in two teleost fish, winter flounder (Pleuronectes americanus) and Atlantic salmon (Salmo salar), reveals a similar pattern of CaR tissue expression. Exposure of the lumen of winter flounder urinary bladder to the CaR agonists, Gd(3+) and neomycin, reversibly inhibit volume transport, which is important for euryhaline teleost survival in seawater. Within 24-72 hr after transfer of freshwater-adapted Atlantic salmon to seawater, there are increases in their plasma Ca(2+), Mg(2+), and Na(+) that likely serve as a signal for internal CaRs, i.e., brain, to sense alterations in salinity in the surrounding water. We conclude that CaRs act as salinity sensors in both teleost and elasmobranch fish. Their tissue expression patterns in fish provide insights into CaR functions in terrestrial animals including humans.

Panic disorder among Vietnamese refugees attending a psychiatric clinic: prevalence and subtypes

This study surveys Vietnamese refugees attending two psychiatric clinics to determine both the prevalence of panic disorder (PD) as well as panic attack subtypes in those suffering PD. A culturally valid adaptation of the SCID-panic module (the Vietnamese Panic Disorder Survey or VPDS) was administered to 100 Vietnamese refugees attending two psychiatric clinics. Utilizing culturally sensitive panic probes, the VPDS provides information regarding both the presence of PD and panic attack subtypes during the month prior to interview. Of 100 patients surveyed, 50 (50%) currently suffered PD. Among the 50 patients suffering PD, the most common panic attack subtypes during the previous month were the following: "orthostatic dizziness" (74% of the 50 panic disorder patients [PDPs]), headache (50% of PDPs), wind-induced/temperature-shift-induced (24% of PDPs), effort-induced (18% of PDPs), gastro-intestinal (16% of PDPs), micturition-induced (8% of PDPs), out-of-the-blue palpitations (24% of PDPs), and out-of-the-blue shortness of breath (16% of PDPs). Five mechanisms are adduced to account for this high PD prevalence as well as the specific profile of subtypes: 1) a trauma-caused panic attack diathesis; 2) trauma-event cues; 3) ethnic differences in physiology; 4) catastrophic cognitions generated by cultural syndromes; and 5) a modification of Clark's spiral of panic.

Emergency contraception

Emergency contraception is often misunderstood by the general public and nurses alike. This article outlines information about methods of post-coital contraception that all nurses need to provide appropriate health advice to women in any nursing setting. This article first appeared in Nursing Standard. 14, 7, 38-43. Readers who successfully completed a written 'practice profile assessment' on that occasion may not do so again.

Emergency contraception: implications for nursing practice

Emergency contraception is often misunderstood by the general public and nurses alike. This article outlines information about methods of post-coital contraception that all nurses need to provide appropriate health advice to women in any nursing setting.

Effects of aerobic exercise on serum leptin levels in obese women

It has been demonstrated that leptin concentrations in obese patients may be altered by weight loss. We examined the effects of a 9-week aerobic exercise program on serum leptin concentrations in overweight women (20-50% above ideal body mass) under conditions of weight stability. Sixteen overweight women, mean (SE) age 42.75 (1.64) years, comprised the exercise group which adhered to a supervised aerobic exercise program. A graded exercise treadmill test was conducted before and after the exercise program to determine maximal oxygen uptake (VO2max) using open-circuit spirometry. The women demonstrated improved aerobic fitness (VO2max increased 12.29%), however, body fat and the body mass index did not change significantly [42.27 (1.35)-41.87 (1.33)%]. Fourteen women, age 40.57 (2.80) years, did not exercise over the same time period and served as a control group. Serum leptin levels were not significantly altered for either the exercise [28.00 (2.13)-31.04 (2.71) ng x ml(-1)] or the control group [33.24 (3.78)-34.69 (3.14) ng x mg(-1)]. The data indicate that 9 weeks of aerobic exercise improves aerobic fitness, but does not affect leptin concentrations in overweight women.

Conditional reasoning, causality, and the structure of semantic memory: strength of association as a predictive factor for content effects

Available evidence indicates that responses to conditional inferences using concrete causal premises is affected by the relative number of available alternate causes (Cummins, D.D., 1995. Memory and Cognition 23 (5), 646-658). We propose that another important factor that may influence the kinds of inferences made to causal conditionals is the relative strength of association between such causes and the consequent term. We present a study with adult participants that examines the effect of strength of association on performance on a conditional reasoning task using causal premises for which there exist one highly associated potential cause for the given consequent term. We predicted that adults would produce a greater proportion of biconditional responses to invalid forms with strongly associated premises than weakly associated ones, while valid forms would not be affected by strength of association. The results are consistent with this hypothesis.

The development of conditional reasoning and the structure of semantic memory

The present article examines 2 predictions concerning conditional reasoning in children derived from a revised version of Markovits's model of conditional reasoning. The first study examined the prediction that younger children (8 years of age) would have greater difficulty in responding correctly to premises where the antecedent was strongly associated with the consequent than to premises where the association was weaker; for example, "If something is a car, then it has a motor" should be more difficult than "If something is a refrigerator, then it has a motor." A total of 55 children in grades 2 and 3 (average age: 8 years) and 49 children in grades 5 and 6 (average age: 11 years) were given either 2 strongly associated problems or weakly associated counterparts. Results indicated that 8-year-olds did better on the weakly associated problems than on the strongly associated problems, but there was no difference among the 11-year-olds. The second study examined the prediction that younger children (8 years of age) would have greater difficulty in responding correctly to causal premises ("If a rock is thrown at a window, the window will break") than to corresponding ad hoc premises ("A rock is something that can be used to break a window"). A total of 53 children in grades 2 and 3 (average age: 8 years) and 49 children in grades 5 and 6 (average age: 11 years) were given either 2 causal problems or ad hoc counterparts. Results indicated that 8-year-old did better on the ad hoc problems than on the causal problems, but there was no difference among the 11-year-olds. These studies are interpreted as consistent with the idea that 1 major factor in the development of reasoning in this age level is the development of children's ability to explore their own knowledge base.

Protein kinase C activation stimulates calcium transport in adrenal zona glomerulosa cells

Adrenal zona glomerulosa (ZG) cells produce aldosterone in response to angiotensin II and extracellular potassium through different mechanisms which involve changes in cytosolic free calcium (Cai). Protein kinase C (PKC) activation is part of the angiotensin II signalling cascade but its effects on Cai are unknown. PKC activation with 1 microM phorbol 12-myristate 13-acetate (PMA) and 8 mM Ko significantly increased the rate of calcium influx (P < 0.001). Both the PKC- and the Ko-induced calcium influx occurred via a nifedipine-sensitive pathway. When both were combined, PKC activation and 8 mM Ko were not additive over either agent alone. PKC activation and 8 mM Ko also stimulated calcium efflux (P < 0.01). When combined together PKC activation and 8 mM Ko had additive effects on calcium efflux (P < 0.05). PKC activation did not increase Cai nor the exchangeable calcium pool in contrast to 8 mM Ko which significantly increased both (P < 0.001). Thus, PKC activation in ZG cells induces a pattern of calcium transport characterized by accelerated calcium recycling across the cell membrane without increasing cell calcium content.

Cloning and characterization of a calcium-sensing receptor from the hypercalcemic New Zealand white rabbit reveals unaltered responsiveness to extracellular calcium

The extracellular Ca2+ (Ca(0)2+)-sensing receptor (CaR) recently cloned from mammalian parathyroid, kidney, brain, and thyroid plays a central role in maintaining near constancy of Ca(0)2+. We previously showed that the hypercalcemia normally present in New Zealand white rabbits is associated with an elevated set point for Ca(02+)-regulated PTH release (the level of Ca(0)2+ half-maximally inhibiting hormonal secretion). This observation suggested an alteration in the Ca(02+)-sensing mechanism in the rabbit parathyroid, a possibility we have now pursued by isolating and characterizing the rabbit homolog of the CaR. The cloned rabbit kidney CaR (RabCaR) shares a high degree of overall homology (> 90% amino acid identity) with the bovine, human, and rat CaRs, although it differs slightly in several regions of the extracellular domain potentially involved in binding ligands. By Northern analysis and/or immunohistochemistry, a similar or identical receptor is also expressed in parathyroid, thyroid C cells, small and large intestine, and in the thick ascending limb and collecting ducts of the kidney. When expressed transiently in HEK293 cells and assayed functionally through CaR agonist-evoked increases in Ca(i)2+, the rabbit CaR shows apparent affinities for Ca(0)2+, Mg(0)2+, and Gd(0)3+ that are indistinguishable from those observed in studies carried out concomitantly using the human CaR. Therefore, at least as assessed by its ability to increase Ca(i)2+ when expressed in HEK293 cells, the intrinsic functional properties of the rabbit CaR cannot explain the hypercalcemia observed in vivo in the New Zealand white rabbit.

Amyloid-beta proteins activate Ca(2+)-permeable channels through calcium-sensing receptors

The amyloid-beta peptides (A beta) are produced in excess in Alzheimer's disease (AD) and may contribute to neuronal dysfunction and degeneration. This study provides strong evidence for a novel cellular target for the actions of A beta, the phospholipase C-coupled, extracellular Ca(2+)-sensing receptor (CaR). We demonstrate that A beta(s) produce a CaR-mediated activation of a Ca(2+)-permeable, nonselective cation channel (NCC), probably via elevation in cytosolic Ca2+ (Cai), in cultured hippocampal pyramidal neurons from normal rats and from wild type mice but not those from mice with targeted disruption of the CaR gene (CaR -/-). A beta(s) also activate NCC in CaR-transfected but not in nontransfected human embryonic kidney (HEK293) cells. Thus aggregates of A beta deposited on hippocampal neurons in AD could appropriately activate the CaR, stimulating Ca(2+)-permeable channels and causing sustained elevation of Cai with resultant neuronal dysfunction.

Deficient cation channel regulation in neurons from mice with targeted disruption of the extracellular Ca2+-sensing receptor gene

This study presents evidence that a receptor sensitive to the concentration of extracellular Ca2+ (Ca[2+]o) (CaR) is functionally coupled to ion channels involved in modulation of neuronal excitability. This receptor is expressed in hippocampus and other brain regions, suggesting that it could mediate some of the well-recognized but poorly understood direct actions of extracellular Ca2+ (Ca[2+]o) on neuronal function. The effects of polycationic CaR agonists on the activity of a nonselective cation channel (NCC) in cultured hippocampal neurons from wild-type mice and from mice homozygous for targeted disruption of the CaR gene (CaR -/-) were compared in this study. The CaR agonists, neomycin (100 microM), spermine (300 microM), and elevation of Ca(2+)o from 0.75 to 3 mM, significantly increased the probability of channel opening (Po) in wild-type neurons. None of these agents, however, produced any effect on Po in neurons from mice lacking the CaR. The same NCC, however, could be activated by thapsigargin in neurons from both wild-type mice and CaR-deficient mice, most likely through an associated increase in the cytosolic free calcium concentration (Ca[i]). Thus the CaR regulates the activity of Ca2+-permeable NCC in hippocampal neurons and could potentially modulate key neuronal functions, including neurotransmission and neuronal excitability, via membrane depolarization.

Expression and characterization of inactivating and activating mutations in the human Ca2+o-sensing receptor

Nearly 30 mutations have been identified to date in the coding region of the extracellular calcium-sensing receptor (CaR) that are associated with inherited human hypo- and hypercalcemic disorders. To understand the mechanisms by which the mutations alter the function of the receptor may help to discern the structure-function relationships in terms of ligand-binding and G protein coupling. In the present studies, we transiently expressed eight known CaR mutations in HEK293 cells. The effects of the mutations on extracellular calcium- and gadolinium-elicited increases in the cytosolic calcium concentration were then examined. Seven inactivating mutations, which cause familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism, show a reduced functional activity of the receptor because they may 1) reduce its affinity for agonists; 2) prevent conversion of the receptor from a putatively immature, high mannose form into the fully glycosylated and biologically active form of the CaR, in addition to lowering its affinity for agonists; or 3) fail to couple the receptor to and/or activate its respective G protein(s). Conversely, one activating mutation, which causes a form of autosomal dominant hypocalcemia, appears to increase the affinity of the receptor for its agonists.