British Medical Association enters GM-crop affray.
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Biomedical subjects
Publications and source records attributed to P Mitchell.
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In three experiments, children aged between 4 and 7 years viewed a circular disc oriented at a slant. The disc was made of luminous material and situated in a darkened chamber. Children of all ages exaggerated the circularity of the disc when they knew that the object was really a circle (the circle task), and the effect was greatest in the younger members of the sample. Crucially, however, a group of children in Experiment 3 who viewed an identical shape that they knew emanated from an actual ellipse did not exaggerate circularity. In the second experiment, children tackled three standard theory of mind tasks in addition to the circle task mentioned above. A significant correlation emerged (even with age partialed) between the extent of exaggeration made by those who knew that the shape was a circle and ability to pass the theory of mind tests. It seems knowledge of reality contaminates judgements of appearance in the circle task. This might be the same bias that features in realist errors in theory of mind tasks.
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BACKGROUND: Spinocerebellar ataxia type 2 (SCA2) is a recently delineated cause of autosomal dominant cerebellar ataxia type I. The basic clinical neurologic features of SCA2 have been described in the literature, but neuropsychological features have not, despite statements that some patients became demented. OBJECTIVE: To describe the clinical and neuropsychological features of patients from a pedigree with SCA2. PATIENTS AND METHODS: We studied 8 affected members of an Australian pedigree of northern Italian origin with autosomal dominant cerebellar ataxia type I caused by SCA2. Patients underwent clinical neurologic examination and abbreviated neuropsychological testing, while some also underwent magnetic resonance imaging. The results were compared with pooled results from previously published studies of patients with SCA2. RESULTS: The pedigree displayed anticipation, with earlier onset in later generations, and there was an inverse correlation between repeat number and age at onset. The principal difference from other clinical reports of SCA2 was our finding of unequivocal frontal-executive dysfunction in 5 of 6 individuals who could be tested quantitatively, despite Mini-Mental State Examination scores in the nondemented range. This feature did not appear to correlate with either repeat size or duration of illness. CONCLUSIONS: In light of a recent report of frontal-executive dysfunction in spinocerebellar ataxia type III, we postulate that this pattern may be common to the autosomal dominant cerebellar ataxias and frequently may be overlooked because of the insensitivity of routine screening tests such as the Mini-Mental State Examination.
OBJECTIVE: To quantify the relationship between pseudoexfoliation (PXF) and open-angle glaucoma, ocular hypertension, and intraocular pressure (IOP) in a defined older population. METHODS: A cross-sectional study of 3654 people aged 49 to 97 years identified subjects with PXF during slitlamp examination. The IOP was measured by applanation tonometry. Glaucoma was diagnosed from characteristic visual field loss combined with optic disc cupping and rim thinning, without reference to IOP. Ocular hypertension was diagnosed if IOP was greater than 21 mm Hg in either eye, without field and disc changes. General estimating equation models were used to assess associations between eyes with PXF and glaucoma or ocular hypertension. RESULTS: Pseudoexfoliation was diagnosed in 2.3% of subjects, and both prevalence and bilaterality increased with age. Glaucomatous damage was present in 14.2% of eyes with PXF compared with 1.7% of eyes without PXF (age- and sex-adjusted odds ratio (OR), 5.0; 95% confidence interval (CI), 2.6-9.6). This was almost unchanged (OR, 4.8) after adjustment for glaucoma risk factors and was also relatively unaffected by IOP adjustment (OR, 3.7; 95% CI, 1.8-7.6). For subjects with PXF, the relationship with glaucoma persisted, but was weaker (OR, 2.3; 95% CI, 1.0-5.0) in the multivariate model. However, the population attributable risk from PXF was only 2.7%. Ocular hypertension was also more frequent in eyes with PXF (9.3%) than in eyes without PXF (3.1%) but was of borderline significance in the multivariate model (OR, 2.3; 95% CI, 0.9-5.7). CONCLUSIONS: This study confirmed the strong relationship between glaucoma and PXF. Subjects with PXF had an increased risk of glaucoma, while eyes with PXF had a higher risk, which was independent of other glaucoma risk factors, including IOP.
OBJECTIVE: To describe the sources of protein intake in a sample of the US adult population and among subgroups defined by race-ethnicity, age, and gender. DESIGN: The Third National Health and Nutrition Examination Survey, 1988-1991, is a stratified random sample of the total civilian noninstitutionalized population, drawn from the 50 United States and the District of Columbia. For all foods consumed by the participants, based on a 24-hour dietary recall, protein sources and the contribution of each protein type to the total protein intake were determined. SUBJECTS: Adult participants in the third National Health and Nutrition Examination Survey (n = 7,924). STATISTICAL ANALYSES: Weighted total, age-specific, and age-adjusted mean protein intakes were calculated using SAS and WesVarPC. Statistical differences were determined by 2-tailed t tests. RESULTS: The main protein source in the American diet is animal protein (69%). Meat, fish, and poultry protein combined contributed the most to animal protein (42%), followed by dairy protein (20%). Grains (18%) contributed the most to plant protein consumption. Women consumed a lower percentage of beef (14%) and pork (7%) protein than did men (18% and 9%, respectively). Women also consumed a higher percentage of poultry (13%), dairy (22%), and fruit and vegetable (11%) protein than did men (11%, 19%, and 9%, respectively). Blacks reported eating a higher percentage of poultry (18%) and pork (11%) protein and a lower percent of dairy protein (14%) than did whites (12%, 7%, and 22%, respectively) and Mexican-Americans (11%, 8%, and 17%, respectively). Mexican-Americans consumed a higher percentage of legume (7%) and egg (7%) protein than did whites (4% and 4%, respectively) and blacks (4% and 5%, respectively). Whites consumed a higher percentage of grain protein (19%) than did blacks (16%) and Mexican-Americans (15%). CONCLUSIONS: These results show that, although the percentage of total energy from protein may be similar among race-ethnicities and between men and women, their sources of protein are different. These differences should be taken into account when providing nutrition education for specific populations.
PURPOSE: To compare optic disk size in eyes of subjects classified as normal with the eyes of subjects with open-angle glaucoma, ocular hypertension, or pseudoexfoliation syndrome in an older population-based sample. METHODS: The Blue Mountains Eye Study examined 3,654 subjects. Vertical disk diameter was measured from stereoscopic disk photographs, and we used spherical equivalent refraction to correct for magnification. Analyses used all eyes in a general estimating equation model. RESULTS: Mean disk diameter was 1.556 mm in glaucomatous eyes, significantly different (P <.05) than normal eyes (1.506 mm) and eyes with ocular hypertension (1.494 mm) or pseudoexfoliation (1.501 mm). CONCLUSIONS: Patients with glaucoma have slightly larger optic disks than nonglaucomatous subjects.
The present study examined the influences of the selective 5-HT1A receptor antagonist, WAY-100635, on the social and agonistic behavior exhibited by male resident mice during encounters with unfamiliar intruder conspecifics. Acute administration of WAY-100635 (0.01-1.0 mg/kg sc) dose dependently enhanced the duration of resident maintenance behavior, reaching statistical significance at 1.0 mg/kg. The duration of resident attend/approach behavior was reduced at 0.01 mg/kg. Drug-free intruder animals showed a reduction in the frequency and duration of attend/approach behavior when the resident mice were treated with 0.01 mg/kg WAY-100635. No other significant effects on behavior were detected for WAY-100635. A previous investigation reported that WAY-100635 induced anxiolytic-like effects in the mouse light/dark box test. In the present study, however, the level of defensive behavior of the saline-treated resident mice was too low for any further anxiolytic-like attenuation of this behavior to be observed. Therefore, no conclusions regarding the potential anxiolytic activity of WAY-100635 may be drawn from the data presented here. Current results are consistent with data for the lack of effect of WAY-100635 on rat agonistic behavior but contrast with findings for the effects of the 5-HT1A receptor antagonists (+)-WAY-100135 and SDZ 216-525 on mouse agonistic behavior.
OBJECTIVE: To assess associations between the stages of age-related maculopathy (ARM) and dietary intake of carotene, vitamin C, retinol, and zinc. DESIGN: Cross-sectional, population-based study. PARTICIPANTS: A total of 3654 subjects 49 years of age and older from a defined area, west of Sydney, Australia, participated. A total of 2900 participants (79.4%) completed accurate food records. INTERVENTION: Masked grading of stereoscopic macular photographs, detailed interviewer-administered questionnaire, and 145-item self-administered food frequency questionnaire. MAIN OUTCOME MEASURES: Late ARM and early ARM were diagnosed from photographic grading. RESULTS: The authors found no statistically significant associations between ARM and dietary intake of either carotene, zinc, or vitamins A or C, either from diet or supplements or from the combined intake from diet and supplements. Multivariate-adjusted odds ratios (95% confidence interval) were calculated comparing highest to lowest dietary intake quintiles. For late ARM, the odds ratios were carotene, 0.7 (range, 0.3-2.0); vitamin A, 1.2 (range, 0.5-3.3); vitamin C, 1.3 (range, 0.5-3.4); and zinc, 1.0 (range, 0.4-2.8). For early ARM, the odds ratios were carotene, 0.7 (range, 0.4-1.1); vitamin A, 1.2 (range, 0.7-2.0); vitamin C, 0.9 (range, 0.5-1.4); and zinc, 0.8 (range, 0.5-1.3). No significant trends were apparent. Adjustment for energy intake also showed no associations between these antioxidants and ARM. Further, no associations were found between increasing intake of foods high in antioxidant vitamins and decreasing prevalence of either late or early ARM. CONCLUSIONS: The authors found no associations between ARM and dietary antioxidants, either from diet alone or including supplements, or from selected foods, in the Blue Mountains Eye Study population.
OBJECTIVE: To determine prevalence and associations with refractive errors in a defined older population. DESIGN: Cross-sectional study. PARTICIPANTS: A total of 3654 residents, aged 49-97, of the Blue Mountains, west of Sydney, Australia. METHODS: Comprehensive questionnaire and detailed eye examination, including refraction. MAIN OUTCOME MEASURES: Refractive error of phakic eyes, age, gender, and education. RESULTS: Prevalence rates were determined for myopia (15%), hyperopia (57%), and emmetropia (28%). Hyperopia prevalence was age-related, increasing from 36% in persons aged <60 years to 71 % of persons aged > or = 80 (P < 0.0001), whereas myopia prevalence decreased with age, from 21 % in persons aged <60 years to 10% of persons aged > or = 80 years (P < 0.0001). Younger myopic subjects in this population reported first wearing distance correction at a significantly younger age than older subjects, P < 0.0001. After adjustment for age, women were slightly more hyperopic (mean +0.75 diopters [D]) than men (mean +0.59 D, P = 0.0012. The gender-adjusted mean spherical error increased with age from +0.03 D in persons aged <60 years to +1.2 D in persons aged > or = 80 years (P < 0.0001). The gender-adjusted mean cylinder power also increased with age, from -0.6 D in persons aged <60 years to -1.2 D in persons aged > or = 80 years (P < 0.0001). The mean axis of astigmatism was "against the rule" in all age groups. Anisometropia increased with age, from a mean of 0.4 D in persons aged <60 to 0.9 D in persons aged > or = 80 years (P < 0.0001). Higher education was associated with myopia in men (P = 0.009) but not in women (P = 0.21) after adjustment for age. CONCLUSION: This report has documented the detailed refractive status of an older population, confirming previously described trends but also finding an apparent higher prevalence of myopia among younger members of this community.
OBJECTIVE: To quantify the relationship between myopia and open-angle glaucoma, ocular hypertension (OH), and intraocular pressure (IOP) in a representative older population. DESIGN: Cross-sectional population-based study of 3654 Australians 49 to 97 years of age. METHODS: Subjects with any myopia (> or =-1.0 diopter [D]) were identified by a standardized subjective refraction and categorized into low myopia (> or =-1.0 D to <-3.0 D) or moderate-to-high myopia (> or =-3.0 D). Glaucoma was diagnosed from characteristic visual field loss, combined with optic disc cupping and rim thinning, without reference to IOP. Ocular hypertension was diagnosed when applanation IOP was greater than 21 mmHg in either eye in the absence of glaucomatous visual field and optic disc changes. MAIN OUTCOME MEASURE: General estimating equation models were used to assess associations between eyes with myopia and either glaucoma or OH. RESULTS: Glaucoma was present in 4.2% of eyes with low myopia and 4.4% of eyes with moderate-to-high myopia compared to 1.5% of eyes without myopia. The relationship between glaucoma and myopia was maintained after adjusting for known glaucoma risk factors, odds ratio (OR) of 2.3, and 95% confidence intervals (CI) of 1.3 to 4.1 for low myopia. It was stronger for eyes with moderate-to-high myopia (OR, 3.3; CI, 1.7-6.4). Only a borderline relationship was found with OH, OR of 1.8 (CI, 1.2-2.9) for low myopia, and OR of 0.9 (CI, 0.4-2.0) for moderate-to-high myopia. Mean IOP was approximately 0.5 mmHg higher in myopic eyes compared to nonmyopic eyes. CONCLUSIONS: This study has confirmed a strong relationship between myopia and glaucoma. Myopic subjects had a twofold to threefold increased risk of glaucoma compared with that of nonmyopic subjects. The risk was independent of other glaucoma risk factors and IOP.
OBJECTIVE: Until recently, inhaled corticosteroids were not considered to cause elevated intraocular pressure (IOP), although topical and oral corticosteroids have been shown to do so in susceptible individuals. The authors aimed to (1) identify whether an association existed between inhaled corticosteroid use and elevated IOP or open-angle glaucoma and (2) determine whether this effect may have a genetic basis. DESIGN: Cross-sectional, population-based study of 3654 persons 49 to 97 years of age attending the Blue Mountains Eye Study, near Sydney, Australia. METHODS: A series of questions assessed use of inhaled and other corticosteroids as well as family history of glaucoma. Elevated IOP was assessed using applanation tonometry. Diagnosis of glaucoma was based on automated perimetry defects and optic disc signs but without reference to IOP. MAIN OUTCOME MEASURE: Statistical analysis of associations between inhaled corticosteroid use and elevated IOP or glaucoma, by family history, adjusting for other risk factors. RESULTS: Open-angle glaucoma was diagnosed in 108 subjects, and elevated IOP was found in 160 subjects. In persons with a glaucoma family history, there was a strong association between inhaled corticosteroid use and presence of either glaucoma or elevated IOP (odds ratio [OR], 2.6; 95% confidence interval, 1.2-5.8). The risk increased with higher doses (OR, 6.3; 95% CI, 1.0-38.6) for persons who used more than four puffs per day. These findings were not explained by concurrent use of oral or ocular corticosteroids. In persons without a family history of glaucoma, no association was found between use of inhaled corticosteroids and glaucoma or elevated IOP. CONCLUSIONS: These findings suggest an association between ever use of inhaled corticosteroids and a finding of elevated IOP or glaucoma in subjects with a glaucoma family history. Patients being treated with inhaled corticosteroids need review by an ophthalmologist if they report a glaucoma family history.
AIM: To determine whether clinical symptoms manifested during an episode of major depression are sufficient to allow meaningful sub-groups of non-melancholic depression to be identified. METHODS: A sample of 178 non-melancholic patients with a major depressive episode was studied. The initial set of clinical variables was refined to 38 (21 depression, 17 anxiety) items and a cluster analysis undertaken. RESULTS: A four-cluster solution identified 'anxiety', 'irritability', 'depressed mood' and 'residual' clusters, with these labels clarified by reference to a large data bank of non-symptomatic variables. These analyses suggested that members of the first two clusters could be viewed as having spectrum conditions (whereby Axis I symptom states are able to be linked with precursor or prodromal states and personality). CONCLUSIONS: We confirm the long-standing suggestion that the non-melancholic depressive class contains sub-groups of those with manifest states of anxious depression and of an irritable or 'hostile' depression, and that such manifest symptoms are likely to be rooted in and fed by temperament and personality characteristics. The delineation of such sub-groups should assist studies designed to identify underlying neurobiological underpinnings and clinical management of the non-melancholic depressive disorders.
Several case reports and open studies have reported the efficacy of lamotrigine in bipolar depression. A randomised placebo-controlled 7-week study comparing two doses of lamotrigine with placebo in 195 patients with moderate to severe bipolar depression has now been completed. Lamotrigine was superior to placebo after 3 weeks as assessed by changes in the Montgomery-Asberg Depression Rating Scale (MADRS). A response, defined as more than 50% improvement on the MADRS occurred in 56 and 48% of the lamotrigine 200 and 50 mg/day groups, respectively, compared with 29% for placebo (P<0.05). There was no evidence that lamotrigine destabilised mood or precipitated mania. Tolerability was good and there were no cases of serious rashes. Preliminary results from an ongoing study also indicate that lamotrigine is more effective than gabapentin in bipolar depression. In conclusion, lamotrigine is effective in alleviating bipolar depression, without causing mood destabilisation. Slow dosage escalation yields good tolerability.
BACKGROUND: Although depressed patients demonstrate impaired performance on a range of neuropsychological tests, there is little research that examines either frontal cognitive deficits or possible differences in test performance between melancholic and non-melancholic subtypes. METHODS: Depressed subjects were administered a broad neuropsychological battery. In an overall analysis, 77 depressed subjects were compared with 28 controls. In a second set of analyses, the depressed sample was divided into melancholic and non-melancholic subsets according to DSM-III-R, the CORE system and the Newcastle scale. These depressed subsets were contrasted to controls and with each other using ANCOVA controlling for age, IQ, simple reaction time and Hamilton Depression scores where appropriate. RESULTS: The total depressed sample was impaired on most mnemonic tasks, simple reaction time and Trails B. Similar findings applied to DSM-III-R melancholic and non-melancholic subjects. When defined by the CORE and Newcastle (narrower definitions of melancholia), melancholic patients were additionally impaired on WCST (perseverative response) and (for Newcastle) digit symbol substitution. In contrast, the cognitive performance of the CORE and Newcastle-defined non-melancholic patients was largely unimpaired. CONCLUSIONS: Using narrower definitions of melancholia, i.e. CORE and (in particular) Newcastle, melancholic patients were impaired on mnemonic tasks and tasks of selective attention, and set-shifting while non-melancholic subjects were largely unimpaired in their cognitive performance. These differences may be due to impairment of specific neuroanatomical regions in narrowly defined melancholic patients, in particular the anterior cingulate.