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Biomedical subjects

A Pickering

Publications and source records attributed to A Pickering.

At least 19 recordsLinked to original sources
PubMed2005

Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices.

The effluent of 17 sewage treatment works (STW) across Norway, Sweden, Finland, The Netherlands, Belgium, Germany, France and Switzerland was studied for the presence of estradiol (E2), estrone (E1), ethinylestradiol (EE2) and nonylphenol (NP). Treatment processes included primary and chemical treatment only, submerged aerated filter, oxidation ditch, activated sludge (AS) and combined trickling filter with activated sludge. The effluent strength ranged between 87 and 846 L/PE (population equivalent), the total hydraulic retention time (HRT) ranged between 4 and 120 h, sludge retention time (SRT) between 3 and 30 d, and water temperature ranged from 12 to 21 degrees C. The highest estrogen values were detected in the effluent of the STW which only used primary treatment (13 ng/L E2 and 35 ng/L E1) and on one occasion in one of the STW using the AS system (6.5 ng/L E2, 50.5 ng/L E1, but on three other occasions the concentrations in this STW were at least a factor of 6 lower). For the 16 STW employing secondary treatment E2 was only detected in the effluent of six works during the study period (average 0.7-5.7 ng/L). E1 was detected in the effluent of 13 of the same STW. The median value for E1 for the 16 STW with secondary treatment was 3.0 ng/L. EE2 was only detected in two STW (1.1, <0.8-2.8 ng/L). NP could be detected in the effluent of all 14 STW where this measurement was attempted, with a median of 0.31 microg/L and values ranging from 0.05 to 1.31 microg/L. A comparison of removal performance for E1 was carried out following prediction of the probable influent concentration. A weak but significant (alpha<5%) correlation between E1 removal and HRT or SRT was observed.

Environmental Monitoring↗
PubMed2003

Initial management of ocular hypertension and primary open-angle glaucoma: an evaluation of the royal college of ophthalmologists' guidelines.

PURPOSE: The purpose of this study was to identify any consensus of opinion among consultant ophthalmologists in Wales with respect to the initial management of glaucoma referrals based on the published guidelines of the Royal College of Ophthalmologists (RCO) and to compare consultant opinion with the practice in a typical hospital. METHOD: The RCO guidelines document was studied to identify clear statements, which could be adopted as standards for audit purposes. A questionnaire was designed and sent to all consultant ophthalmologists in Wales (n=37) to obtain their opinions. An audit was performed of 100 consecutive patients referred to our unit as glaucoma suspects with regard to initial management. Descriptive statistical analysis was performed. RESULTS: A good response rate for a postal questionnaire was obtained (81%) with 79.1% of responders finding the guidelines of at least some help. Levels of agreement with the definitions of ocular hypertension (OH) and primary open-angle glaucoma (POAG) were 76.7 and 86.7%, respectively. There was consensus of consultant opinion regarding many of the elements of the baseline clinical assessment with the significant exceptions of the necessity for dilated fundoscopy, gonioscopy, retinal nerve fibre layer assessment, and drawing of optic discs. The various 'clinical scenarios' for management of the RCO document were not all endorsed. The clinical audit results of the initial management of glaucoma referrals accurately reflected the consensus of the consultant opinion. DISCUSSION: The RCO guidelines document represents a useful contribution to the management of patients with OH and POAG. Nevertheless, considerable variation in opinion exists concerning even the most basic areas. With the advent of clinical governance, bridging the gap between the conclusions of College working parties and realities of everyday practice will assume greater importance.

Attitude of Health Personnel↗
PubMed2002

Ventilation and health in non-industrial indoor environments: report from a European multidisciplinary scientific consensus meeting (EUROVEN).

Scientific literature on the effects of ventilation on health, comfort, and productivity in non-industrial indoor environments (offices, schools, homes, etc.) has been reviewed by a multidisciplinary group of European scientists, called EUROVEN, with expertise in medicine, epidemiology, toxicology, and engineering. The group reviewed 105 papers published in peer-reviewed scientific journals and judged 30 as conclusive, providing sufficient information on ventilation, health effects, data processing, and reporting, 14 as providing relevant background information on the issue, 43 as relevant but non-informative or inconclusive, and 18 as irrelevant for the issue discussed. Based on the data in papers judged conclusive, the group agreed that ventilation is strongly associated with comfort (perceived air quality) and health [Sick Building Syndrome (SBS) symptoms, inflammation, infections, asthma, allergy, short-term sick leave], and that an association between ventilation and productivity (performance of office work) is indicated. The group also concluded that increasing outdoor air supply rates in non-industrial environments improves perceived air quality; that outdoor air supply rates below 25 l/s per person increase the risk of SBS symptoms, increase short-term sick leave, and decrease productivity among occupants of office buildings; and that ventilation rates above 0.5 air changes per hour (h-1) in homes reduce infestation of house dust mites in Nordic countries. The group concluded additionally that the literature indicates that in buildings with air-conditioning systems there may be an increased risk of SBS symptoms compared with naturally or mechanically ventilated buildings, and that improper maintenance, design, and functioning of air-conditioning systems contributes to increased prevalence of SBS symptoms.

Air Pollution, Indoor↗
PubMed2001

Neuroimaging correlates of negative priming.

Many theoretical accounts of selective attention and memory retrieval include reference to active inhibitory processes, such as those argued to underlie the negative priming effect. fMRI was used in order to investigate the areas of cortical activation associated with Stroop interference, Stroop facilitation and Stroop negative priming tasks. The most significant activation within the negative priming task was within the inferior parietal lobule, left temporal lobe and frontal lobes. Areas of cortical activation are discussed with reference to theoretical accounts of the negative priming effect.

Adult↗
PubMed2001

The differential effects of chlorpromazine and haloperidol on latent inhibition in healthy volunteers.

Latent inhibition (LI) is a measure of reduced learning about a stimulus to which there has been prior exposure without any consequence. It therefore requires a comparison between a pre-exposed (PE) and a non-pre-exposed (NPE) condition. Since, in animals, LI is disrupted by amphetamines and enhanced by antipsychotics, LI disruption has been proposed as a measure of the characteristic attentional deficit in schizophrenia: the inability to ignore irrelevant stimuli. The findings in humans are, however, inconsistent. In particular, a recent investigation suggested that since haloperidol disrupted LI in healthy volunteers, and LI was normal in non-medicated patients with schizophrenia, the previous findings in schizophrenic patients were entirely due to the negative effects of their medication on LI (Williams et al., 1998). We conducted two studies of antipsychotic drug effects on auditory LI using a within-subject, parallel group design in healthy volunteers. In the first of these, single doses of haloperidol (1 mg. i.v.) were compared with paroxetine (20 mg p.o.) and placebo, and in the second, chlorpromazine (100 mg p.o.) was compared with lorazepam (2 mg. p.o.) and placebo. Eye movements, neuropsychological test performance (spatial working memory (SWM), Tower of London and intra/extra dimensional shift, from the CANTAB test battery) and visual analogue rating scales, were also included as other measures of attention and frontal lobe function. Haloperidol was associated with a non-significant reduction in LI scores, and dysphoria/akathisia (Barnes Akathisia Rating Scale) in three-quarters of the subjects. The LI finding may be explained by increased distractibility which was indicated by an increase in antisaccade directional errors in this group. In contrast, LI was significantly increased by chlorpromazine but not by an equally sedative dose of lorazepam (both drugs causing marked decreases in peak saccadic velocity). Paroxetine had no effect on LI, eye movements or CANTAB neuropsychological test performance. Haloperidol was associated with impaired SWM, which correlated with the degree of dysphoria/akathisia, but no other drug effects on CANTAB measures were detected. We conclude that the effect of antipsychotics on LI is both modality and pharmacologically dependent and that further research using a wider range of antipsychotic compounds is necessary to clarify the cognitive effects of these drugs, and to determine whether there are important differences between them.

Acoustic Stimulation↗
PubMed2000

Outcome of anorexia nervosa: eating attitudes, personality, and parental bonding.

BACKGROUND: We examined eating attitudes, personality, and parental bonding in women with a history of anorexia nervosa stratified by degree of recovery in comparison to randomly selected controls. We were interested in the distinguishing characteristics of recovery and of chronic anorexia nervosa. METHOD: All female new referrals to an eating disorders service between January 1, 1981 and December 31, 1984 with probable or definite anorexia nervosa were eligible for inclusion. 86.4% of these women ("cases") were located and agreed to participate. The control group was a random community sample. All subjects were interviewed with a structured diagnostic instrument and completed a battery of psychological inventories including the Eating Disorder Inventory (EDI), the Three-Factor Eating Questionnaire (TFEQ), the Temperament and Character Inventory (TCI), and the Parental Bonding Instrument (PBI). RESULTS: We divided the anorexia follow-up sample into full recovery (n = 21), partial recovery (n = 34), and chronically ill (n = 15) and compared them to community controls (n = 98). The chronically ill group was distinguished by a lower desired body mass index (BMI), higher cognitive restraint on the TFEQ, higher Drive for Thinness and Bulimia on the EDI, lower maternal and paternal care on the PBI, and high harm avoidance and low self-directedness on the TCI. The full recovery group scored high on self-directedness and cooperativeness on the TCI. CONCLUSIONS: The domains of personality, character, and parental bonding differ among categories of recovery in anorexia nervosa. Whether these differences contribute to recovery or emerge during recovery or lack thereof remains an unanswered question.

Adult↗
PubMed2000

CNS acetylcholine receptor activity in European medicinal plants traditionally used to improve failing memory.

Certain Lamiaceous and Asteraceous plants have long histories of use as restoratives of lost or declining cognitive functions in western European systems of traditional medicine. Investigations were carried out to evaluate human CNS cholinergic receptor binding activity in extracts of those European medicinal plants reputed to enhance or restore mental functions including memory. Ethanolic extracts were prepared from accessions of these plants and a number of other species related by genus. Amongst the plant extracts screened for contents able to displace [3H]-(N)-nicotine and [3H]-(N)-scopolamine from nicotinic receptors and muscarinic receptors, respectively in homogenates of human cerebral cortical cell membranes, the most potent extracts, prepared from one accession of Melissa officinalis, three Salvia species and Artemisia absinthium had IC50 concentrations of < 1 mg/ml. The displacement curves of some extracts were comparable with that of carbamylcholine chloride, a potent acetylcholine analogue. Choline, a weak nicotinic ligand (IC50 = 3 x 10(-4) M) was found in extracts of all plants studied at concentrations of 10(-6)-10(-5) M. These concentrations could not account for not more than 5% of the displacement activity observed. Some extracts displayed differential displacement at nicotinic and muscarinic acetylcholine receptors, with M. officinalis 0033 having the highest [3H]-(N)-nicotine displacement value and Salvia elegans with the highest [3H]-(N)-scopolamine displacement value. There was also considerable variation in cholinoreceptor interactions between different accessions of a single plant species. Although most plant extracts screened showed some nicotinic and muscarinic activity, only some showed dose-dependent receptor activity typical of materials with genuine cholinergic activity.

Asteraceae↗
PubMed1999

Hippocampal involvement in spatial and working memory: a structural MRI analysis of patients with unilateral mesial temporal lobe sclerosis.

Forty-seven patients with unilateral temporal lobe epilepsy (TLE) were investigated on the Nine-Box Maze. The task was designed to compare working memory and spatial mapping theories of the functions of the hippocampus and provide measures of spatial, object, working, and reference memory. The results extended our previous findings in a larger group of patients. Spatial memory deficits across both working and reference memory conditions were found in patients with a right epileptogenic focus. There was no evidence of an object working memory deficit, but a nonlateralized impairment in object reference memory was revealed, which is consistent with our previous findings. The pattern of results was confirmed in a subgroup of 33 patients with unilateral atrophy localized to the hippocampus and parahippocampal gyrus, as verified by volumetric analysis of magnetic resonance images. In addition spatial memory errors significantly correlated with volumetric measures of mesial temporal lobe structures and not with measures of the remaining temporal cortex. In contrast, object reference memory errors correlated with volumetric measures of the temporal cortex and not with mesial temporal lobe structures. These findings support a specialized role for the right hippocampal region in spatial memory.

Adult↗
PubMed1999

Relatives' lived experiences of complementary therapies in a critical care department--a phenomenological study.

This phenomenological study examined relatives' lived experiences of complementary therapies in the Department of Critical Care Medicine at Royal Hobart Hospital. Participants in the study, 20 relatives of critically ill patients, were involved in a non-structured, audiotaped interview. Subsequently, transcripts were analysed using a phenomenological transformative process to identify common themes in the text. Study findings suggested four emerging conceptual categories, which with further analysis uncovered the essence of the phenomenon as extending and enriching a caring atmosphere.

Adolescent↗
PubMed1999

Fertility and reproduction in women with anorexia nervosa: a controlled study.

BACKGROUND: Women who have anorexia nervosa may experience difficulties with fertility and reproduction. METHOD: We examined fertility and reproductive history in 66 women who had a history of anorexia nervosa (DSM-III-R) and 98 randomly selected community controls as part of a follow-up investigation examining the course of anorexia nervosa. RESULTS: Although women with a history of anorexia nervosa and controls did not differ on rate of pregnancy, mean number of pregnancies per woman, or age at first pregnancy, women with anorexia nervosa had significantly more miscarriages and cesarean deliveries, and the offspring of women with anorexia nervosa were significantly more likely to be born prematurely and were of lower birth weight than offspring of controls. There were no differences between women with active versus remitted anorexia nervosa on any of these measures; however, offspring of anorexic women with no history of bulimia nervosa had significantly lower body weight than offspring of anorexic women with a lifetime history of bulimia nervosa. CONCLUSION: Our results argue for intensive prenatal care for women with both active and remitted anorexia nervosa to ensure adequate prenatal nutrition and fetal development.

Adult↗
PubMed1998

Outcome of anorexia nervosa: a case-control study.

OBJECTIVE: Although there have been many studies of the outcome of anorexia nervosa, methodological weaknesses limit their interpretation. The authors used a case-control design to try to improve knowledge about the outcome of anorexia nervosa. METHOD: All new female patients referred to an eating disorders service between Jan. 1, 1981, and Dec. 31, 1984, who had probable or definite anorexia nervosa were eligible for inclusion. Of these women, 86.4% (N = 70) were located and agreed to participate. The comparison group (N = 98) was a random community sample. All subjects were interviewed with a structured diagnostic instrument. RESULTS: A minority of the patients (10%) continued to meet the criteria for anorexia nervosa a mean of 12 years after initial referral. Even among those who no longer met these criteria, relatively low body weight and cognitive features characteristic of anorexia nervosa (perfectionism and cognitive restraint) persisted. The rates of lifetime comorbid major depression, alcohol dependence, and a number of anxiety disorders were very high. CONCLUSIONS: In the managed care/brief treatment era, therapeutic approaches with an excessive focus on weight gain that neglect the detection and treatment of associated psychological features and comorbidity may be inappropriate. Anorexia nervosa is a serious psychiatric disorder with substantial morbidity.

Adolescent↗
PubMed1997

Spatial memory deficits in patients with unilateral damage to the right hippocampal formation.

Patients with unilateral temporal lobe damage resulting from intractable temporal lobe epilepsy (TLE, n = 30) or from temporal lobe resection (temporal lobectomy, TLR, n = 47) were investigated on the Nine-box Maze. The task, analogous to the radial arm maze, was designed to compare spatial mapping and working memory theories of the functions of the hippocampus. The task provides measures of spatial, object, working and reference memory, incorporated into a within subjects design. The spatial component was designed to encourage the formation of allocentric rather than egocentric spatial representations. Spatial memory deficits were found (across working and reference memory components) in both TLE and TLR patients with right temporal lobe damage, with intact spatial memory in patients with corresponding left temporal lobe damage. Performance on the matched non-spatial (object) working memory component was equal to healthy controls for all groups. However all patient groups showed a deficit on object reference memory. These findings are discussed in relation to the underlying temporal lobe pathology and particularly atrophy of the hippocampal formation. Overall, the results support the cognitive mapping theory of hippocampal function, with the demonstration of a selective (and probably allocentric) spatial memory deficit in patients with right hippocampal damage.

Adolescent↗
PubMed1997

Relation between cognitive dysfunction and pseudobulbar palsy in amyotrophic lateral sclerosis.

OBJECTIVES: To examine the relation between cognitive dysfunction and pseudobulbar features in patients with amyotrophic lateral sclerosis (ALS). METHODS: The performance of two patient groups, ALS with pseudobulbar palsy (n = 24) and ALS without pseudobulbar palsy (n = 28), was compared with 28 healthy age matched controls on an extensive neuropsychological battery. Tests used were the national adult reading test, short form of the WAIS-R, recognition memory test, Kendrick object learning test, paired associate learning, Wisconsin card sorting test, verbal fluency, Stroop and negative priming tests, a random movement joystick test, and a computerised Tower of Hanoi test. RESULTS: Tests of executive function showed a pronounced deficit on written verbal fluency in both ALS groups in comparison to controls, which tended to be more prominent in patients with ALS with pseudobulbar palsy. The random movement joystick test (a non-verbal test of intrinsic movement generation) showed an impairment in the generation of random sequences in patients with pseudobulbar palsy only. The computerised Tower of Hanoi showed a subtle planning impairment (shorter planning times) in all the patients with ALS compared with controls on trials requiring more complex solutions. In addition the pseudobulbar patients displayed shorter planning times on complex trials, and tended to solve these trials less accurately. There was also evidence of a deficit for all patients with ALS in comparison with controls on total errors and number of categories achieved on the Wisconsin card sorting test and a strong tendency towards an impairment on a task of selective attention and cognitive inhibition (negative priming). A word recognition memory deficit was showed across both ALS groups. CONCLUSIONS: This study elicited cognitive deficits (involving predominantly executive processes, with some evidence of memory impairment) in patients with ALS and further strengthened the link between ALS and frontal lobe dysfunction, this being more prominent in patients with pseudobulbar palsy. However, cognitive impairments suggestive of extramotor cortical involvement were not exclusive to this subgroup.

Adult↗
PubMed1996

A case of comorbid anorexia nervosa, bulimia nervosa, and Munchausen's syndrome.

Reports of comorbid eating disorders and Munchausen's syndrome are rare. As part of a follow-up study of the outcome of anorexia nervosa, medical records and direct structured psychiatric interview data were collected on all women treated for anorexia nervosa in Christchurch, New Zealand between 1981-1984. On interview, one participant received diagnoses of anorexia nervosa, bulimia nervosa, and factitious disorder (Munchausen's syndrome). The subject interwove symptoms of her eating disorders with factitious presentations on several occasions. This diagnosis had not been apparent prior to compilation of all medical records.

Adult↗