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Biomedical subjects

A Burns

Publications and source records attributed to A Burns.

At least 37 records · Page 2Linked to original sources

Calculated glomerular filtration rate is a useful screening tool to identify scleroderma patients with renal impairment.

OBJECTIVES: Although it only occurs in a minority of patients, renal involvement is a life-threatening complication of scleroderma (SSc). We have investigated the utility of two formulae to calculate glomerular filtration rate (GFR) in a population of SSc patients. METHODS: Twenty-six patients (20 female, 6 male, median age 58 yr, age range 12-80 yr) satisfied our criteria for inclusion in a retrospective comparison of measured and calculated GFR. GFR was measured using (51)Cr-EDTA. The modified Cockcroft and Gault formula and equation 7 from the Modification of Diet in Renal Disease (MDRD) were used to calculate GFR. RESULTS: Eighteen out of 19 patients analysed with a serum creatinine concentration less than the upper limit of the normal range had a measured GFR outside the normal range. Three patients with a normal creatinine concentration had a measured GFR <60 ml/min and in each of these the calculated GFR was also abnormal. All patients with a measured GFR <60 ml/min were identified using both the MDRD and the modified Cockcroft and Gault formula to calculate GFR. The greatest correlation between measured and calculated GFR was seen when the MDRD formula, which employs demographic and serum variables, was used in patients with body surface area (BSA) >1.4 m(2) who were not taking Iloprost (r=0.91). Use of the Cockcroft and Gault formula to calculate creatinine clearance with a correction factor for GFR, the inclusion of patients taking Iloprost and the inclusion of patients with BSA <1.4 m(2) were all associated with a lower degree of correlation. CONCLUSION: Serum creatinine is a poor marker of renal function in SSc patients. Calculating GFR from demographic and serum variables is a simple technique to identify SSc patients who have abnormal renal function. The authors recommend the use of the MDRD formula.

Adolescent↗

The effect of anticholinesterases on personality changes in Alzheimer's disease.

Anticholinesterases are known to be effective against cognitive and non-cognitive symptoms of Alzheimer's disease (AD) but their effect on the personality changes in the disease is not known. This study examines the effect of anticholinesterase treatment on personality changes in AD. It involved the carers of patients with mild to moderate AD who were currently receiving anticholinesterases in south Manchester. The personality change was measured using the Brooks and McKinlay Personality Inventory. The carers were asked to complete the inventory for each of three periods in the patients' lives: before the onset of AD, after the diagnosis of AD but before starting anticholinesterases, and currently on anticholinesterases. Fifty-eight carers participated in the study. Personality became more negative (total score on the personality inventory became less) following the onset of AD (p < 0.001). Following anticholinesterase treatment, the total score on the personality inventory remained the same or increased in 23 (39%) patients. Scores on individual personality traits remained the same or increased in the majority of patients. In approximately one fifth of the patients, the traits 'does things himself', 'happy', 'calm' and 'cautious' showed improvement on anticholinesterases. The study confirms that personality changes are almost universal and negative in AD and suggests that anticholinesterases may have a positive effect. Further double blind prospective studies are needed to understand natural progression of personality changes in AD and to validate the findings of this study.

Aged↗

Inherited frontotemporal dementia in nine British families associated with intronic mutations in the tau gene.

Genetic screening of 171 patients with frontotemporal lobar degeneration disclosed 14 patients, across nine pedigrees, with mutations in the intron to exon 10 in the tau gene, a region regulating the splicing of exon 10 via a stem loop mechanism. Thirteen of these patients had the +16 splice site mutation and one had the +13 splice site mutation. Affected members of all nine families presented with changes in behaviour and social conduct that were prototypical of frontotemporal dementia (FTD). In all patients with the +16 splice site mutation, the behavioural profile was characterized by disinhibition, restless overactivity, a fatuous affect, puerile behaviour and verbal and motor stereotypies. The single patient with the +13 mutation presented a contrasting picture of apathy and inertia. In addition, all patients had evidence of semantic loss. Pathologically, five of the six patients so far autopsied shared frontotemporal atrophy with involvement of the substantia nigra. The underlying histology was that of microvacuolar-type cortical degeneration with a few swollen cells. Tau pathology was widespread throughout the brain and present in neurones and glial cells, mostly in the frontal and temporal cortical regions. This was in the form of neurofibrillary tangles and amorphous tau deposits (pre-tangles); Pick bodies were not observed. Ultrastructurally, the tau filaments had a twisted, ribbon-like morphology distinct from the paired helical filaments of Alzheimer's disease. One patient died from an unrelated illness whilst in the early clinical stages of FTD. In this patient, cortical microvacuolar and astrocytic changes were absent, though there were scattered neurones and glial cells, immunoreactive to tau, throughout the cortical and subcortical regions. The disease process underlying the neurodegeneration within these inherited forms of FTD may therefore stem directly from early, primary alterations in the function of tau. All eight families with the +16 mutation seem to be part of a common extended pedigree, possibly originating from a founder member residing within the North Wales region of Great Britain.

Age of Onset↗

Confirmation of uterotrophic activity of 3-(4-methylbenzylidine)camphor in the immature rat.

In this study we found that the ultraviolet sunscreen component 3-(4-methylbenzylidine)camphor (4MBC) is uterotrophic in immature rats when administered by either subcutaneous injection or oral gavage. These data confirm earlier reports of uterotrophic activity for this agent when administered to immature rats in the diet or by whole-body immersion; however, they are in contrast to negative unpublished immature rat uterotrophic assay results. Data also indicate that 4MBC binds to isolated rat uterine estrogen receptors and shows activity in a human estrogen receptor yeast transactivation assay; however, we considered both of these effects equivocal. In this study, we confirmed the original observation that 4MBC was active as a mitogen to MCF-7 breast cancer cells. We evaluated and discounted the possibility that the estrogenic activity of 4MBC is related to its bulky camphor group, which is of similar molecular dimensions to that of the weak estrogen kepone. Uncertainty remains regarding the mechanism of the uterotrophic activity of 4MBC.

Administration, Oral↗

Factors affecting survival of elderly nursing home residents.

OBJECTIVE: To examine whether the admission characteristics of nursing home residents predict mortality and to look for factors that account for different mortality rates between those homes. METHODS: A retrospective case note audit of the admission characteristics of residents in nursing homes registered with the Manchester Health Authority who died within a 12 month period and a group of current residents matched by age, sex and length of stay. Time between admission and death was examined using actuarial estimators of survival and factors predicting time between admission and death were examined using the proportional hazards model of Cox. Standardised mortality ratios (SMR) were calculated on each of the homes from the Office for National Statistics for Greater Manchester Metropolitan County. Logistic regression was used to assess those factors that predicted death at 1, 2 and 4 weeks and 3, 6 and twelve months after admission. RESULTS: Following admission the mean survival time was 5.9 years. There was a wide variation in the mortality ratio between the homes and five of the 32 studied had SMRs of over 7. Increasing age, male sex, poor appetite, sleep disturbance, build, place of admission from, history of malignancy and respiratory disease and the number of prescribed drugs were all found to be significant predictors of mortality. Malignancy, pressure sores, poor appetite and number of prescribed drugs predicted death with 4 weeks after admission. CONCLUSION: Some nursing homes have higher mortality rates than others although this was accounted for by the characteristics of the residents and not by any measurable characteristic of the nursing home environment.

Age Factors↗

Clinical features of dementia associated with apolipoprotein epsilon4: discrimination with a neural network genetic algorithm.

BACKGROUND: It is unclear whether the APOE epsilon4 allele is associated with distinct clinical features in dementia. METHOD: 100 cases meeting ICD criteria for dementia were interviewed using standardized instruments and genotyped for APOE. The presence of the epsilon4 allele was used by a genetic algorithm neural network (GANN) to discriminate symptoms and signs. RESULTS: The GANN selected six features: gender, systolic blood pressure, absence of ankle tendon reflexes, history of weight loss, history of falls, and interviewer observed lability of mood. Using these features, a neural network discriminated cases according to epsilon4 highly accurately (area under receiver operating characteristic=0.83, sensitivity=0.78, specificity=0.78). CONCLUSIONS: A GANN is able to discriminate a clinically distinct group of features among dementia patients who express the epsilon4 allele.

Accidental Falls↗

Regional cerebral volume measurements in late-life depression: relationship to clinical correlates, neuropsychological impairment and response to treatment.

BACKGROUND: Elderly people who develop depression have demonstrable changes in cerebral structure but little is known of the relationship between regional cerebral volumes, treatment response and cognitive impairment. METHOD: Forty-four patients with major depression diagnosed according to DSM-IIIR criteria underwent magnetic resonance imaging and regional cerebral volumes were quantified using multispectral analysis. Response to antidepressant treatment was assessed prospectively and a neuropsychological test battery was administered. RESULTS: There was a trend for smaller fronto-temporal volumes in the treatment-resistant patients. Impaired immediate working memory was linked with reduced frontal and parietal lobe volume and impaired short-term memory functioning was associated with reduced temporal lobe volume. Ventricular enlargement was associated with prior administration of electro-convulsive therapy, poor physical health and later age at onset of first episode of depression. CONCLUSION: In late-life depression, brain changes should not preclude vigorous antidepressant treatment. Regional cerebral volume changes may be a complication of poor physical health and are associated with memory dysfunction even upon recovery from depression.

Age Factors↗

Depressive symptoms in patients with Alzheimer's disease.

OBJECTIVES: A comparison was made between the depressive symptom profiles of thirty patients with Alzheimer's disease (AD) who did not have co-existing depression and thirty patients with major depression who did not have co-existing dementia. The main objective was to identify symptoms common to both disorders and those which may be able to differentiate AD from major depression. METHOD: A sample of patients suffering from either AD (n = 30) or major depression (n = 30) were recruited from a specialist old age psychiatry service. Depressive symptoms were profiled using the Hamilton Depression Rating Scale (HDRS), the Cornell Scale for Depression in Dementia (CSDD) and the Geriatric Depression Scale (GDS). RESULTS: Depressive symptoms were present in AD in the absence of coexistent major depression. Certain depressive symptoms from all the three scales such as sadness, diurnal variation in mood and early or late insomnia were able to differentiate the two disorders with almost 90% accuracy while symptoms such as irritability, retardation and weight loss were common to both and were unable to differentiate the two. CONCLUSION: Depressive symptoms occur in AD when co-existing depression is ruled out. Their recognition has implications for the diagnosis of major depression in these patients.

Aged↗

Glucuronidation of nonylphenol and octylphenol eliminates their ability to activate transcription via the estrogen receptor.

Both p-nonylphenol (NP) and p-octylphenol (OP) exhibit weak estrogen-like activity in in vitro and in some rodent assays. To help understand the biochemical and molecular basis for these effects, and thus to permit extrapolation of risk to human health, it is important to establish whether these activities are retained by their metabolites. These data are particularly important in light of the knowledge that both NP and OP are rapidly and extensively metabolized to their glucuronide conjugates in rats. The activity of these glucuronide metabolites, however, is unknown. These studies investigated the intrinsic ability of NP, OP, and their principal mammalian metabolites, nonylphenol glucuronide (NPG) and octylphenol glucuronide (OPG), to affect estrogen receptor (ER)- or androgen receptor (AR)-mediated transcription in a yeast transcriptional activation system. Specifically, the estrogen-, anti-estrogen-, androgen-, and anti-androgen-like activities of NP, OP, NPG, and OPG have been assessed using recombinant yeast strains that express either human ER or AR. The two parent compounds, NP (EC(50) 110 nM) and OP (EC(50) 700 nM), exhibited intrinsic estrogen-like activity in this system, and consistent with numerous studies with these chemicals, they were 3-4 orders of magnitude less potent than 17beta-estradiol (EC(50) 500 pM). However, in contrast to the parent molecules, neither NPG nor OPG exhibited any evidence of estrogen-, antiestrogen-, androgen-, or anti-androgen-like activity in these recombinant yeast strains. Therefore, the weak estrogen-like activity noted for NP and OP in vivo at high doses is likely to reflect saturation of parent molecule glucuronidation. At anticipated levels of human exposure to NP and OP such a saturation of detoxification is highly unlikely; therefore, these in vitro data support the conclusion that the potential endocrine hazard posed by NP and OP to humans is likely to be negligible.

Androgen Antagonists↗

A randomized trial of the effectiveness of cognitive-behavioral therapy and supportive counseling for anxiety symptoms in older adults.

The authors used a randomized trial to compare cognitive-behavioral therapy (CBT) and supportive counseling (SC) in the treatment of anxiety symptoms in older adults who met Diagnostic and Statistical Manual of Mental Disorders (4th ed.: American Psychiatric Association, 1994) criteria for anxiety disorders. Both conditions had a 6-week baseline no-treatment phase. Treatment was delivered primarily in patients' own homes and in an individual format. Outcomes were assessed at posttreatment and at 3-, 6-, and 12-month follow-ups. There was no spontaneous improvement during the baseline phase. Both groups showed improvement on anxiety measures following treatment, with a better outcome for the CBT group on self-rating of anxiety and depression. Over the follow-up period, the CBT group maintained improvement and had significantly greater improvement than the SC group on anxiety and 1 depression measure. Treatment response for anxiety was also superior for the CBT group, although there was no difference between groups in endstate functioning.

Aged↗

Seasonal variation in admission rates to intensive care units.

Intensive care physicians perceive that there is seasonal variation in the number of admissions to critical care services. There is, however, little published evidence to support this belief. Data were therefore collected from five adjacent critical care units in the eastern region over a period of 8 years, in order to quantify any seasonal variation that may exist. Data on 16 355 critically ill patients were obtained between 1992 and 2000. Analysis showed clear winter peaks; December had a 30% higher admission rate than the quietest month, February. There was a small, but increasing, summer peak. The admission rate also exhibits an increasing linear trend, equivalent to a 6.6% annual increase in admissions per critical care bed. We conclude that there is significant seasonal variation in critical care activity, and that this is important to consider when planning services.

Adult↗

Atrial thrombus and central venous dialysis catheters.

A native arteriovenous fistula is the first choice for hemodialysis access. Despite improved catheter designs and the use of internal jugular veins, thrombotic complications still occur when tunneled central venous catheters are used as an alternative. Although right atrial thrombus (RAT) is a well-characterized complication of long-term central venous cannulation, particularly when used for parenteral nutrition and chemotherapy in pediatric practice, only 9 reported cases previously have been associated with the long-term use of central venous catheters for hemodialysis. We report five cases of RAT seen at our unit between 1994 and 1998 in patients who had been dialyzed using tunneled catheters. In four of five cases, the diagnosis was made during the investigation of hemoptysis or dyspnea. In the fifth case, a screening transthoracic echocardiogram revealed the thrombus. Three of five of the patients suffered pulmonary emboli, and a fourth patient had an unexplained electromechanical dissociation cardiac arrest without definite evidence of pulmonary embolus. Our experience suggests that anticoagulated patients with RAT remain at risk of pulmonary embolism. One of our patients successfully underwent atrial thrombectomy. In four of five of our cases and four of nine cases in the literature, the central venous catheter tip was within the right atrium. Positioning of the central venous catheter tip low down in the superior vena cava or in the right atrium has been advocated to improve dialysis adequacy and to reduce the incidence of catheter thrombosis. However, placement of the catheter tip within the right atrium may be associated with an increased risk of RAT.

Adolescent↗