Depot injections and nut allergy.
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Aged↗
Biomedical subjects
R Howard
Publications and source records attributed to R Howard.
Can diving-induced tissue nitrogen supersaturation increase the chance of acoustically driven bubble growth in marine mammals?
The potential for acoustically mediated causes of stranding in cetaceans (whales and dolphins) is of increasing concern given recent stranding events associated with anthropogenic acoustic activity. We examine a potentially debilitating non-auditory mechanism called rectified diffusion. Rectified diffusion causes gas bubble growth, which in an insonified animal may produce emboli, tissue separation and high, localized pressure in nervous tissue. Using the results of a dolphin dive study and a model of rectified diffusion for low-frequency exposure, we demonstrate that the diving behavior of cetaceans prior to an intense acoustic exposure may increase the chance of rectified diffusion. Specifically, deep diving and slow ascent/descent speed contributes to increased gas-tissue saturation, a condition that amplifies the likelihood of rectified diffusion. The depth of lung collapse limits nitrogen uptake per dive and the surface interval duration influences the amount of nitrogen washout from tissues between dives. Model results suggest that low-frequency rectified diffusion models need to be advanced, that the diving behavior of marine mammals of concern needs to be investigated to identify at-risk animals, and that more intensive studies of gas dynamics within diving marine mammals should be undertaken.
Animals↗
The inter- and intraobserver reliabilities of a new classification system for ischaemic stroke: the South London Stroke Register.
OBJECTIVES: This study aims to determine the inter- and intraobserver reliabilities of an aetiological classification devised as part of a community-based stroke register. METHODS: Patients with first-ever acute ischaemic stroke were clinically assessed and received investigation according to a set protocol. Results of the clinical assessment and investigations were used to determine an aetiological stroke subtype for each patient by observer 1. Aetiological subtypes consisted of extracranial large artery atherosclerosis (LAAec), intracranial large artery atherosclerosis (LAAic), high-risk cardioembolism (CH), medium-risk cardioembolism (CM), small vessel occlusion (SVO), other aetiology (OTH), no aetiology identified (NA) and multiple probable or multiple possible aetiology (MPA). The same data were distributed to a further four observers along with the criteria for the classification system. Two of the observers were retested on the same patients after of period of 8 weeks. Inter- and intraobserver agreement was determined using the kappa statistic, which gives the chance-adjusted percentage agreement. RESULTS: Forty-five consecutive patients were included. The overall kappa statistic for ischaemic stroke was 0.91 indicating excellent agreement. Kappa statistics were highest for the more frequent subtypes of SVO (0.97) and CH (0.97). Substantially high kappa statistics were also obtained for the less-frequent categories of LAAec (0.91), CM (0.84), NA (0.89) and MPA (0.87). A low kappa statistic was obtained for the category OTH (0.16), which had a low frequency of reporting, indicating poor agreement. The kappa statistic for probable categories was higher than the kappa statistic for all stroke subtypes at 0.96. Intraobserver agreement between first and second assignments of subtype diagnoses for both observers reached excellent agreement with kappa statistics of 0.83 and 0.85. CONCLUSION: The aetiological classification system, designed for use in the investigation of the epidemiology, stroke subtype and their relation to the natural history of stroke in a multiethnic inner city population, allows high inter- and intrarater agreements of subtype diagnosis.
Acute Disease↗
Quality of care in private sector and NHS facilities for people with dementia: cross sectional survey.
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Aged↗
(1)H-MR spectroscopy differentiates mild cognitive impairment from normal brain aging.
This study aimed to characterize the white matter biochemical profile of healthy elderly subjects, mild cognitive impairment (MCI) subjects, and early Alzheimer's disease (AD) patients. We used proton magnetic resonance spectroscopy ((1)H-MRS) to measure myo-inositol, creatine, N-acetylaspartate (NAA) and choline levels from a volume of interest located in the paratrigonal white matter bilaterally. A significantly higher myo-inositol/creatine ratio was found in MCI subjects and AD patients than in controls. The NAA/creatine ratio was reduced in AD patients in the left hemisphere compared to control subjects. The choline/creatine ratio was not significantly different among the three groups. These data suggest that MCI is different from normal brain aging, having a white matter biochemical pattern similar to AD.
Aged↗
Optimising management of delirium. Patients with delirium should be treated with care.
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Age Factors↗
Do hair care practices affect the acquisition of tinea capitis? A case-control study.
OBJECTIVE: To determine the influences of hair-grooming practices and environmental factors as risk factors for the acquisition of tinea capitis (TC) in children. DESIGN: Case-control study comparing children with culture-proved TC with age-, sex-, and race-matched control subjects without scalp disease. SETTING: A multicenter study involving 3 urban referral centers in the United States. PARTICIPANTS: A convenience sample of 66 patients aged 12 years and younger presenting to pediatric dermatology clinics with clinical evidence of TC were enrolled as cases. Matched control subjects (n = 68), without known scalp disease, were enrolled from the outpatient pediatric clinics at the same institutions. RESULTS: Significant associations with TC in the conditional logistic regression model were a prior history of TC (odds ratio, 3.11; 95% confidence interval, 1.02-9.43; P =.04) and exposure to TC (odds ratio, 16.32; 95% confidence interval, 3.55-75.16; P =.001). The use of a hair conditioner was statistically significant in the univariable model but not in the multivariable model (odds ratio, 0.46; 95% confidence interval, 0.20-1.08; P =.07). Hairstyling, frequency of washing, use of oils or grease, and other hair care practices were not shown to be associated with the presence of TC. CONCLUSIONS: Hair-grooming practices do not appear to play a major role in the acquisition of TC. Hair conditioners may be protective in children at risk for TC, but further studies are needed to confirm this finding.
Case-Control Studies↗
Depression in older people with mild stroke, carotid stenosis and peripheral vascular disease: a comparison with healthy controls.
BACKGROUND: Although depression has a recognised association with stroke, the role of "silent" cerebrovascular pathology associated with carotid stenosis and peripheral vascular disease remains unexplored. METHODS: Four groups of 25 community residents aged 65 and over were recruited, comprising first anterior circulation stroke, carotid stenosis accompanied by transient ischaemic attack, peripheral vascular disease and a non-vascular control group. All participants were interviewed using the Hamilton Rating Scale for Depression [HRSD] (including a modified version) and Geriatric Depression Scale. DSM IV criteria for major depression and measures of handicap, social support and physical illness were also administered. Head computerised tomography (CT) scans were performed on stroke patients to examine the relationship between lesion location and depression. RESULTS: One hundred patients were interviewed. Stroke patients were more likely to live in a nursing home and had less social support than other groups. Mean scores on the modified Hamilton and Geriatric Depression Scales were higher in stroke and carotid stenosis groups than controls. Patients with stroke did not show a higher prevalence of DSM IV major depressive disorder than those with carotid stenosis. There was no relationship between the presence of lesions affecting the frontal/subcortical system and prevalence/severity of depression. LIMITATIONS: Small numbers, mortality of stroke patients in hospital, possible selection bias in the control group and use of a previously unvalidated depression rating scale all limit the study. CONCLUSIONS: A possible role for carotid stenosis in the pathogenesis of depressive disorder is suggested. Larger studies incorporating brain imaging may be required to examine the mechanism of this association more closely. The use of a shorter version of the HRSD in older people with cerebrovascular disease may warrant further exploration.
Aged↗
Guidelines for the management of agitation in dementia.
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Aged↗
Florid reactive periostitis and bizarre parosteal osteochondromatous proliferation: pre-biopsy imaging evolution, treatment and outcome.
OBJECTIVE: To report on the imaging evolution of florid reactive periostitis (FRP) and bizarre parosteal osteochondromatous proliferation (BPOP) of the phalanges of the hands from prospective diagnosis to operation and on postsurgical outcome. DESIGN AND PATIENTS: Three patients (2 female, 1 male; age range 11-34 years) presented with a swollen digit of the hand. Following presumptive radiographic diagnosis of FRP, they were closely observed both clinically and radiographically until operation. All three patients had radiographs of the involved digit, and one patient had an MR imaging examination. The interval between presumptive diagnosis and operation ranged from 2 to 8 months. Following operation, the patients have been clinically followed for 9-13 months (mean 10 months). RESULTS: In each of the patients, maturing of periosteal reaction without bone destruction was observed within 1-2 weeks of the presumptive diagnosis of FRP. Periosteal reaction was initially minimal in relation to the extent of soft tissue swelling and subsequently became more florid. In one patient, the lesion ossified, became adherent to the phalanx, and had an "osteochondromatous" appearance. In another patient, periosteal reaction was seen on both sides of the phalanx with an intact phalanx. In the sole patient who had MR imaging, edema was seen in the phalanx distal to the symptomatic site and the metacarpal proximal to the symptomatic site. CONCLUSIONS: Close clinical and radiographic correlation permits an accurate pre-biopsy diagnosis of FRP. The first follow-up radiograph taken within 2 weeks usually provides re-assurance of the accuracy of the diagnosis. FRP may progress to BPOP. Arbitrary antibiotic treatment can be avoided, and a planned surgical approach can be adopted.
Adult↗
Persecutory delusions: a review and theoretical integration.
Persecutory (paranoid) delusions are a frequently observed clinical phenomenon. In recent years, an increasing volume of research has attempted to explain these types of beliefs in terms of psychological mechanisms. Theories have emphasized early experience, perceptual abnormalities, motivational factors, and information-processing deficits. In this article we review relevant findings, including our own studies of the role of causal attributions and theory of mind deficits. We propose a new integrative model that builds on this work. The core of the model is an account of the way that causal attributions influence self-representations, which in turn influence future attributions: the attribution--self-representation cycle. We argue that biases in this cycle cause negative events to be attributed to external agents and hence contribute to the building of a paranoid world view. These abnormalities are amenable to investigation by functional neuroimaging, and recent studies have implicated specific areas of neuroactivation. However, these findings do not necessarily suggest that paranoid delusions are entirely biological in origin, and there is evidence that adverse early experience may play a role in determining the development of a cognitive vulnerability to paranoid thinking.
Cognition↗
Are beta blockers effective in African Americans with systolic heart failure?
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Journal Article↗
Liver iron estimation in beta-thalassaemia: comparison of MRI biochemical assay and histological grading.
AIMS: The aims of the study were to compare the efficacy of magnetic resonance imaging (MRI), biochemical assay and histological grading in estimating liver iron content, and to evaluate the value of liver to muscle signal intensity ratio (L/M ratio) on spin-echo T1-weighted images in this role. MATERIALS AND METHODS: Thirty-nine homozygous beta-thalassaemics had their L/M ratio measured on MRI, followed by ultrasound-guided liver biopsies with histological grading of iron storage and biochemical quantification of liver iron concentration (LIC-b) using atomic absorption spectrophotometry. RESULTS: A significant difference in L/M ratios between the four grades of iron storage on histology was observed (P < 0.001). The coefficient of correlation was -0.67 between L/M ratio and LIC-b ranging from 2 to 21.6 mg/g dry weight. Specific values of L/M ratio reliably reflected liver iron content at clinically important levels. A L/M ratio of < 0.6 has 86% sensitivity and 100% specificity in the prediction of grade 3 or 4 iron storage histologically and 81% sensitivity and 81% specificity in predicting LIC-b > 15 mg/g. A L/M ratio of > 0.8 predicts a histological iron storage grading of 0 or 1 with a 100% sensitivity and 74% specificity. CONCLUSION: L/M ratio on MRI is of value as a non-invasive alternative to repeated liver biopsies for estimating liver iron content at clinically important thresholds.
Adolescent↗
Anti-interleukin-2 receptor therapy in combination with mycophenolate mofetil is associated with more severe hepatitis C recurrence after liver transplantation.
The pathogenesis of hepatitis C virus (HCV) recurrence after liver transplantation (LT) is poorly understood, but the cellular immune response is likely to have a major role. Daclizumab, an interleukin-2 receptor (IL-2R) antibody that blunts T-cell activation, leading to a decreased risk for cellular rejection, is used frequently in transplant recipients. The aim of this study is to evaluate the effect of daclizumab therapy on the incidence and severity of recurrent HCV. Forty-one liver transplant recipients (21 patients, HCV positive; 20 patients, HCV negative) at high risk for neurological or renal complications of calcineurin inhibitors were administered daclizumab, mycophenolate mofetil (MMF), and steroids in the early post-LT period, followed by tacrolimus and a steroid taper. All patients were followed up prospectively for graft function and disease recurrence with protocol liver biopsies day 7, month 4, and yearly. Compared with patients without HCV, patients with HCV administered daclizumab had greater 4-month serum alkaline phosphatase, total bilirubin, and alanine aminotransferase (ALT) levels. These biochemical differences resolved by 12 months, except for persistent elevation of ALT levels. Compared with a well-matched HCV control population, patients with HCV administered daclizumab were more likely to have an earlier onset of hepatitis, jaundice, and greater histological activity. Recurrent hepatitis progressed more rapidly in the daclizumab group; 45% developed advanced disease within 1 year. HCV viral load in the daclizumab group was significantly greater at both 4 months and 1 year. Results of this study suggest that the use of adjuvant IL-2R antibodies in combination with MMF in the early peritransplantation period may be associated with early recurrence of hepatitis C and more rapid histological progression of disease.
Adult↗
Behavioural management of aggression in dementia: a randomized controlled trial.
OBJECTIVE: To evaluate the efficacy of a brief behaviour management training programme for family carers of patients with dementia and aggressive behaviour. DESIGN: A randomized controlled trial of a four-session, community-based behaviour management programme. The primary outcome measure was the Rating Scale for Aggressive Behaviour in the Elderly. PARTICIPANTS: 62 patients with dementia, and their co-resident carers. RESULTS: There were no significant differences in aggression scores between behaviour management and control groups at follow-up. After adjusting for baseline differences in Rating Scale for Aggressive Behaviour in the Elderly scores, there was a trend towards a reduction in aggressive behaviour in the patients in the behaviour management group compared with those in the control group (F = 3.37, P = 0.071). CONCLUSIONS: This study adds to the small evidence base for the effectiveness of behavioural management strategies in dementia.
Aged↗
Functional magnetic resonance imaging of odor identification: the effect of aging.
BACKGROUND: Sense of smell declines with age and impairment in olfaction has been observed in some neurodegenerative disorders such as Alzheimer's disease. Functional neuroimaging techniques enable researchers to observe brain regions activated by olfactory stimuli. METHODS: We gave three mainly olfactory-mediated odors (limonene, methylsalicylate, and eugenol) to six young and six elderly subjects and observed the areas activated by using blood oxygen level dependent contrast functional magnetic resonance imaging. RESULTS: The group mapping of young subjects showed extensive activation in the orbitofrontal cortex, commonly believed to be the olfactory cortex, some limbic areas (the hippocampus and the thalamus), regions involved with gustatory sensation (the anterior insula and the inferior postcentral gyrus), superior and inferior temporal gyri, and cerebellum. In the elderly group, only the left inferior temporal gyrus and the primary visual cortex reached accepted significance levels. CONCLUSIONS: We have therefore confirmed previous reports of brain regions involved in olfactory processing in young volunteers and demonstrated decreased activation in elderly volunteers.
Adult↗
Infundibulohypophysitis in a man presenting with diabetes insipidus and cavernous sinus involvement.
Infundibulohypophysitis is an unusual inflammatory condition that affects the infundibulum, the pituitary stalk, and the neurohypophysis and may be part of a range that includes lymphocytic hypophysitis. Lymphocytic hypophysitis occurs mainly in women and most often presents in the later stages of pregnancy. Infundibulohypophysitis usually presents with diabetes insipidus and the cause remains unclear. The case of a 46 year old man with a 12 week history of polyuria and polydipsia is reported. Cranial diabetes insipidus was diagnosed on the basis of a water deprivation test. Initial cranial and pituitary imaging studies were normal. He subsequently developed symptoms of panhypopituitism over a period of 6-9 months and then, more acutely, developed diplopia secondary to a fourth nerve palsy. Further brain imaging studies disclosed an enhancing pituitary stalk and a left cavernous sinus lesion. An initial trial of immunosuppressive treatment did not help symptoms significantly. The diagnosis of infundibulohypophysitis was made on histological evidence. The patient was treated with prednisolone and methotrexate. At 9 months he is well, without symptoms, and the radiological abnormalities have resolved.
Anti-Inflammatory Agents↗
Cerebrovascular risk factors and stroke subtypes: differences between ethnic groups.
BACKGROUND AND PURPOSE: The excess risk of stroke seen in the black population has not been explained by differences in age, sex, and social class, although differences in the frequency of cerebrovascular risk factors may be partly responsible. Data on risk factor profiles for the UK black stroke population are sparse. Previous studies have contrasted the association of cerebrovascular risk factors between hemorrhagic and ischemic stroke and between etiologic subtypes of infarct. The relationship of cerebrovascular risk factors to clinical classifications of stroke, however, has been little examined. The aim of this study was to establish the frequency of cerebrovascular risk factors in patients with first-ever strokes in the South London, UK, population and to examine the relationship of these risk factors to both ethnicity and Bamford stroke subtype. METHODS: The study included 1254 first-ever stroke patients registered in the South London Community Stroke Register between 1995 and 1998; 995 patients (79.3%) were white, 203 (16.2%) were black, 52 (4.1%) were of other ethnic origin, and 4 (0. 3%) were of unknown ethnic origin. RESULTS: In multivariate analysis, increasing age (P:<0.001) and previous cerebrovascular disease (P:=0.007) were independently associated with infarct rather than hemorrhage. Atrial fibrillation was associated with all nonlacunar (P:=0.02), total anterior circulation (P:=0.007), and partial anterior circulation infarcts (P:=0.02) compared with the lacunar group. All other risk factors were similar between infarct subtypes. Risk factors for hemorrhage subtypes were similar in multivariate analysis; increasing age was the only factor associated with primary intracerebral hemorrhage over subarachnoid hemorrhage (P:<0.001). The black stroke population suffered significantly less atrial fibrillation (P:=0.001) and engaged in less alcohol excess (P:<0. 001) and were less likely to have ever smoked (P:<0.001). Hypertension (P:<0.001) and diabetes mellitus (P:<0.001) were more prevalent in the black population. CONCLUSIONS: Physiological cerebrovascular risk factors for the UK black population are similar to those of the US black population, but behavioral risk factors differ. Risk factors differ between ethnic groups in the United Kingdom, and future measures for secondary prevention should take this into consideration. Bamford clinical subtypes bear little association with cerebrovascular risk factors. Other classification systems, such as those that classify stroke by etiology, may be more useful in explaining the excess risk of stroke and the scope for its prevention.
Age Distribution↗