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Biomedical subjects

C Wallace

Publications and source records attributed to C Wallace.

At least 19 recordsLinked to original sources
PubMed2000

Community care and criminal offending in schizophrenia.

BACKGROUND: The introduction of community care in psychiatry is widely thought to have resulted in more offending among the seriously mentally ill. This view affects public policy towards and public perceptions of such people. We investigated the association between the introduction of community care and the pattern of offending in patients with schizophrenia in Victoria, Australia. METHODS: We established patterns of offending from criminal records in two groups of patients with schizophrenia over their lifetime to date and in the 10 years after their first hospital admission. One group was first admitted in 1975 before major deinstitutionalisation in Victoria, the second group in 1985 when community care was becoming the norm. Each patient was matched to a control, by age, sex, and place of residence to allow for changing patterns of offending over time in the wider community. FINDINGS: Compared with controls, significantly more of those with schizophrenia were convicted at least once for all categories of criminal offending except sexual offences (relative risk of offending in 1975=3.5 [95% CI 2.0-5.5), p=0.001, in 1985=3.0 [1.9-4.9], p=0.001). Among men, more offences were committed in the 1985 group than the 1975 group, but this was matched by a similar increase in convictions among the community controls. Those with schizophrenia who had also received treatment for substance abuse accounted for a disproportionate amount of offending. Analysis of admission data for the patients and the total population of admissions with schizophrenia showed that although there had been an increase of 74 days per annum spent in the community for each of the study population as a whole, first admissions spent only 1 more day in the community in 1985 compared with 1975. INTERPRETATION: Increased rates in criminal conviction for those with schizophrenia over the last 20 years are consistent with change in the pattern of offending in the general community. Deinstitutionalisation does not adequately explain such change. Mental-health services should aim to reduce the raised rates of criminal offending associated with schizophrenia, but turning the clock back on community care is unlikely to contribute towards any positive outcome.

Adult↗
PubMed2000

Analysis of endoglin expression in normal brain tissue and in cerebral arteriovenous malformations.

BACKGROUND AND PURPOSE: A high incidence of arteriovenous malformations (AVMs) is associated with hereditary hemorrhagic telangiectasia type 1. Endoglin, the gene mutated in this disorder, is expressed at reduced levels on blood vessels of these patients. Since endoglin is a component of the transforming growth factor-beta receptor complex critical for vascular development and homeostasis, we determined its expression in sporadic cerebral AVMs and in normal brain vessels. METHODS: Twenty cerebral AVMs and 10 normal brain samples were analyzed for endoglin, platelet endothelial cell adhesion molecule 1 (PECAM-1), alpha-smooth muscle cell actin, vimentin, and desmin by immunohistochemistry. RESULTS: In normal brain, endoglin was found not only on the endothelium of all vessels but also on the adventitial layer of arteries and arterioles. In cerebral AVMs, the numerous vessels present expressed endoglin on both endothelium and adventitia. Arterialized veins, identified by lack of elastin and uneven thickness of smooth muscle cells, revealed endoglin-positive mesenchymal cells in the adventitia and perivascular connective tissue. These cells were fibroblasts since they expressed vimentin but not actin and/or desmin. CONCLUSIONS: This is the first report of endoglin expression on adventitia of normal brain arteries and on arterialized veins in cerebral AVMs. Increasing numbers of endoglin-positive endothelial and adventitial cells were seen in sporadic cerebral AVMs, but endoglin density was normal. Thus, it is not involved in the generation of these lesions. However, the presence of endoglin on fibroblasts in the perivascular stroma suggests an active role for this protein in vascular remodeling in response to increased blood flow and shear stress.

Actins↗
PubMed2000

Herbal tea in the treatment of diabetes mellitus.

OBJECTIVE: To evaluate the effects of a native herbal tea in patients with type 2 diabetes. DESIGN: Randomized, placebo-controlled, single-blind study. SETTING: The Metabolic Centre at the University of Alberta Hospitals. SUBJECTS: Forty volunteers with type 2 diabetes. INTERVENTIONS: After a 1 month "run-in" period, subjects drank 250 mL/d of either the herbal tea or a placebo tea for 10 days, and were followed up for a further 4 weeks. OUTCOME MEASURES: A responder analysis defined as a 10% change in mean blood glucose levels based on 4 capillary glucose readings daily. Secondary end points included changes in HbA1c, fructosamine and response to a meal challenge using Ensure. RESULTS: The responder analysis showed no benefit from the herbal tea. Fructosamine levels before and after tea therapy decreased significantly in both study groups. Mean HbA1c levels and incremental areas under the glucose curve (AUC) in the meal challenge did not change in either study group. These data were reanalysed in hyperglycemic subjects with HbA1c levels greater than 120% of normal. The responder analysis and HbA1c levels did not change in either group. Mean (and standard deviation) fructosamine levels, before and after tea therapy, were significantly lower in the herbal tea group than in the placebo tea group (361 [98] versus 338 [100] micromol/L, p < 0.01 compared with 338 [60] versus 323 [49] micromol/L, p = 0.08). In the hyperglycemic subgroup the mean AUC during the meal challenge, before versus after tea therapy, was 776 (369) versus 639 (331) mmol/L (p = 0.22) in the herbal tea group and 433 (125) versus 420 (173) mmol/L (p = 0.90) in the placebo group. CONCLUSIONS: Although the responder analysis failed to show an effect of the herbal tea, the data suggest there may be a short-term benefit from the tea in subjects with poor glycemic control.

Aged↗
PubMed1999

Tryptophan depletion impairs stimulus-reward learning while methylphenidate disrupts attentional control in healthy young adults: implications for the monoaminergic basis of impulsive behaviour.

RATIONALE: Altered serotonergic and dopaminergic function have been widely implicated in behavioural disorders associated with impulsivity and risk-taking. However, little research has addressed the specific cognitive consequences of changed monoaminergic function that might contribute to the production of impulsive behaviour. OBJECTIVES AND METHODS: We compared the effects of rapid plasma tryptophan depletion, acute doses of the mixed indirect catecholamine agonist, methylphenidate (40 mg), and acute doses of the alpha(1)/alpha(2 )agonist, clonidine (1.5 microg/kg), on aspects of visual discrimination learning involving either acquisition of altered stimulus-reward associations (i.e. updating the affective valence of exteroceptive stimuli) or the control of attention towards relevant as opposed to irrelevant stimulus dimensions. RESULTS: Relative to subjects who received placebo, subjects with reduced tryptophan exhibited a deficit in the ability to learn changed stimulus-reward associations, but were still able to shift an acquired attentional set away from a now-irrelevant stimulus dimension towards a newly relevant dimension. By contrast, subjects who received methylphenidate were able to learn effectively about changing stimulus-reward associations, but showed an enhanced ability to shift an attentional bias, in combination with slowed response times. Subjects who received clonidine showed neither of these changes. CONCLUSIONS: These results suggest that reduction in central serotonin leads to altered neuromodulation of the cortical and subcortical regions (e.g. orbitofrontal cortex, striatum and anterior temporal structures) that mediate important aspects of associative learning whereby exteroceptive stimuli acquire altered incentive motivational value. On the other hand, facilitation of catecholamine neurotransmitters may disrupt the allocation of attention between relevant and irrelevant features of the environment, perhaps through altered modulation of the dorsolateral prefrontal cortex. The implications of these results for understanding the differential neuromodulation of cognitive functions are discussed.

Adolescent↗
PubMed1999

Behavioural changes in the rat following infection with varicella-zoster virus.

Following the establishment of a chronic varicella-zoster virus infection in the rat, behavioural allodynia and hyperalgesia were observed in the injected, but not the contralateral hind limb up to 33 days post-infection. This model may prove useful in investigating mechanisms involved in the establishment of post-herpetic neuralgia.

Animals↗
PubMed1998

Evolution, partnerships and cooperation.

In an evolutionary game theoretic setting, players are allowed to choose not only their strategies for a particular interaction, but also to some extent with whom they will play. A stability concept is presented and examined which allows agents to endogenously construct fixed partnerships. A strategy-matching type is said to be recoverable if a population in which it is used by all players is both internally and externally stable to random mutations. Such a strategy-matching type always exists and maximises social efficiency in the population. Some examples are considered in the light of this concept. The ability to form fixed partnerships enables players to coordinate on efficient outcomes. In particular, cooperation is achieved in the Prisoners' Dilemma without recourse to repetition or rigid spatial restriction.

Animals↗
PubMed1998

Patient satisfaction with screening mammography: online vs off-line interpretation.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine patient satisfaction with online and off-line methods of interpreting screening mammograms and to determine those characteristics that most influence patient preferences. MATERIALS AND METHODS: A survey consisting of 17 questions assessing satisfaction and demographics was distributed to women whose screening mammograms were read in one of two ways at the same facility: (a) the "online" method, in which all additional requested studies are completed and results are immediately communicated, and (b) the "off-line" method, in which mammograms are read in batches the next day, results are communicated at a later time, and patients return for diagnostic studies. To ensure statistical power, at least 174 surveys were collected from each group. RESULTS: Of 192 women whose mammograms were interpreted online, 188 (97%) responded, and of 247 women whose mammograms were interpreted off-line, 181 (73%) responded. Overall mean satisfaction with the mammographic experience and with the time it took to receive results differed significantly between the two groups (P < .002). Analysis of the subgroup of very satisfied respondents disclosed that 92% of patients in the online group and 59% of patients in the off-line group were very satisfied with their mammography experience. If allowed to choose the method of interpretation, 97% of patients in the online group and 91% of patients in the off-line group would choose online interpretation. CONCLUSION: Patients preferred online mammographic interpretation of screening studies.

Adult↗
PubMed1998

Sudden death in psychiatric patients.

BACKGROUND: The present study investigated histories of prior psychiatric treatment in cases of sudden death reported to the coroner. METHODS: A matching survey linked the register of deaths reported to the coroner with a comprehensive statewide psychiatric case register covering both in-patient and community-based services. RESULTS: Sudden death was five times higher in people with histories of psychiatric contact. Suicide accounted for part of this excess mortality but deaths from natural causes and accidents were also elevated. Schizophrenic and affective disorders had similar suicide rates. Comorbid substance misuse doubled the risk of sudden death in affective and schizophrenic disorders. CONCLUSIONS: The rates of sudden death are sufficiently elevated to raise questions about current priorities in mental health care. There is a need both for greater attention to suicide risk, most notably among young people with schizophrenia, to the early detection of cardiovascular disorders and to the vigorous management of comorbid substance misuse.

Accidents↗
PubMed1998

Serious criminal offending and mental disorder. Case linkage study.

BACKGROUND: A relationship exists between mental disorder and offending behaviours but the nature and extent of the association remains in doubt. METHOD: Those convicted in the higher courts of Victoria between 1993 and 1995 had their psychiatric history explored by case linkage to a register listing virtually all contacts with the public psychiatric services. RESULTS: Prior psychiatric contact was found in 25% of offenders, but the personality disorder and substance misuse accounted for much of this relationship. Schizophrenia and affective disorders were also over-represented, particularly those with coexisting substance misuse. CONCLUSIONS: The increased offending in schizophrenia and affective illness is modest and may often be mediated by coexisting substance misuse. The risk of a serious crime being committed by someone with a major mental illness is small and does not justify subjecting them, as a group, to either increased institutional containment or greater coercion.

Age Distribution↗
PubMed1998

Systemic sclerosis: using high-resolution CT to detect lung disease in children.

OBJECTIVE: The purpose of this study was to determine the prevalence of interstitial lung disease and the severity of disease in children with systemic sclerosis using high-resolution CT (HRCT). SUBJECTS AND METHODS: Eleven children (mean age, 11 years) with scleroderma underwent HRCT, chest radiography, and pulmonary function testing. Eight of these 11 patients also underwent follow-up HRCT. HRCT studies were assessed by two observers for ground-glass attenuation, honeycombing, and other abnormalities. Profusion scores for ground-glass attenuation and honeycombing were determined by multiplying severity of disease by the percentage of lung involvement. RESULTS: Chest radiographs predicted interstitial lung disease in only two patients, whereas HRCT showed interstitial lung disease in eight patients (p = .05). On HRCT, ground-glass attenuation was found in eight patients (73%), honeycombing in five patients (45%), linear opacities in six patients (55%), and subpleural micronodules in seven patients (64%). By the end of the study, 10 patients (91%) had evidence of interstitial lung disease on HRCT. Overall, profusion scores for these 10 patients showed four patients with mild, one with moderate, and five with severe disease. Also, HRCT revealed worsening disease in three of eight patients. We found no correlation between duration of scleroderma and severity of interstitial lung disease (p > .02). Seven patients with evidence of lung disease on HRCT had abnormal results on pulmonary function tests; patients with the highest scores for ground-glass attenuation had the most abnormal results on pulmonary function tests (p < .01). CONCLUSION: HRCT shows significant pulmonary disease in children with systemic sclerosis, revealing abnormalities in 91% of our patients. Pulmonary disease should be suspected in children with scleroderma, even if the chest radiograph has normal findings.

Adolescent↗
PubMed1997

General practitioners knowledge of and attitudes to the use of seat belts in pregnancy.

This study was designed to look at General Practitioner's knowledge of and attitudes to the use of seat belts in pregnancy. It has been shown that correct seat belt use does significantly reduce both maternal and fetal morbidity and mortality following RTAs. However, seat belts are infrequently and often incorrectly utilised by women during pregnancy. Passenger safety education is essential. General Practitioners in Ireland are in a prime position to provide this education in early pregnancy. A postal questionnaire was sent to all members of ICGP (n = 1,780). The results show that 70% of GPs are aware that women are obliged by law to use a seat belt while pregnant, and a similar number felt the subject of passenger safety education is an important medical issue. 75% feel women should wear seat belts in third trimester. However, only 30% provide regular advice and less than 50% indicated that they are aware of the correct advice to give. Also GPs are not asked by their pregnant patients for advice. There is no statistically significant difference between male and female GPs. GPs have the opportunity to and so should provide passenger safety advice. This advice must be accurate and safe.

Attitude of Health Personnel↗
PubMed1996

The Pemberton sign.

Explore the source record for details and available documents.

Goiter, Substernal↗
PubMed1995

Tibial mononeuropathy from a lower limb synovial cyst.

BACKGROUND: Tibial mononeuropathy due to compression by a synovial cyst is uncommon with fewer than 10 cases reported in the literature. METHOD: Case Study. RESULTS: Tibial motor mononeuropathy with focal conduction block between the popliteal fossa and ankle was identified by electrophysiological testing. Magnetic resonance imaging and surgical exploration identified a synovial cyst compressing the nerve just distal to the popliteal fossa. CONCLUSIONS: The combination of electrophysiological localization and imaging in cases of unexplained tibial mononeuropathy may identify an unexpected structural cause.

Adult↗
PubMed1995

Fetal thyrotoxicosis: a case report and recommendations for prediction, diagnosis, and treatment.

A maternal history of Graves' disease places the fetus at risk for thyrotoxicosis in utero via the placental transfer of thyroid-stimulating immunoglobulins. Methods for prediction of fetal hyperthyroidism are available, but are not widely used. Clinical assessment of fetal thyroid status by monitoring of fetal heart rate and growth may be inaccurate. This raises some uncertainty in the initial diagnosis of fetal thyrotoxicosis and complicates the assessment of fetal response to maternal propylthiouracil therapy. A case illustrating these pitfalls in the diagnosis and management of fetal hyperthyroidism is presented. The condition was correctly diagnosed, but treatment based on fetal heart rate resulted in biochemical hypothyroidism in the infant at birth. Current recommendations for diagnosis and treatment of fetal hyperthyroidism are reviewed along with recent developments in the field. A modified approach is proposed.

Adult↗
PubMed1995

Clinical indicators contributing to I.C.U. length of stay in elective craniotomy patients with brain tumour.

The immediate purposes of this study are (a) to indicate the I.C.U. and hospital length of stay in elective craniotomy patients with brain tumour, and (b) to identify the clinical indicators that contribute to the I.C.U. length of stay. The ultimate purpose is to contribute to a growing body of knowledge in providing quality and cost effective patient outcomes by creating appropriate vehicles for further research in the field of neuroscience. The following clinical indicators are identified: pre-op patient admission to ward or same day admit unit, O.R. cancellations, type of tumour, nursing staff availability, intubation on admission, I.C.U. length of stay, and post-op complications. The results of this pilot study, with sample size of 55 patients, could assist us in the nursing profession to develop an appropriate Care Map for craniotomy patients with brain tumour.

Adult↗