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Biomedical subjects

Michael Clarke

Publications and source records attributed to Michael Clarke.

10 recordsLinked to original sources
PubMed2006

The influence of catecholamines on pseudocholinesterase enzymatic activity. Results of a laboratory investigation.

OBJECTIVE: Acceleratory and inhibitory receptors have been described on the pseudocholinesterase (PCHE) molecule. An increased PCHE activity has been reported in patients with chronic pain and anxiety, conditions known to be correlated with increased plasma catecholamine levels. Aim of this laboratory investigation was to determine whether catecholamines have an effect on PCHE activity, as this knowledge could help to define the role of PCHE in the assessment of stress. METHODS: After Ethics committee approval and written informed consent, 3 ml of blood was collected from five healthy volunteers. Fourteen samples of 50 mul each were prepared from each of the volunteer's plasma. Epinephrine (25, 50, 100, 200, 400 and 1000 pg) and norepinephrine (50, 100, 200, 400, 800 and 2000 pg) were added to samples of each subject. Sodium-chloride solution was added to control samples. PCHE activity was photometrically assessed. RESULTS: PCHE activity was significantly higher after the addition of epinephrine (median 8304 versus 7386 U/l). This effect was not dose-dependent. PCHE activity did not change after addition of norepinephine. CONCLUSIONS: This mechanism might explain previous findings that showed higher levels of PCHE activity in the presence of chronic pain and anxiety. In the absence of a dose-response curve in the concentration range studied, PCHE activity does not appear to be suitable for the assessment of levels of stress.

Anxiety↗
PubMed2006

Childhood encephalopathy: viruses, immune response, and outcome.

This study examined children with an acute encephalopathy illness for evidence of viral infection, disordered blood-brain barrier function, intrathecal immunoglobulin synthesis, and interferon (IFN) production, and related their temporal occurrence to outcome. A prospective study of 22 children (13 males, 9 females; age range 1mo to 13y, median 2y 4mo), recorded clinical details, with serum and cerebrospinal fluid (CSF) analysis near presentation and then on convalescent specimens taken up to day 39 of the neurological illness. Outcome was assessed with standard scales between 18 months and 3 years after presentation. A history consistent with viral infection was given in 17 children but laboratory evidence of viral infection was found in only 7 (7/17). In 18 out of 21 children, an elevated CSF:serum albumin ratio indicative of impairment of the blood-CSF and blood-brain barriers was detected at some stage of the illness. In 14 of the 15 children with a raised immunoglobulin G index, and in 12 of the 14 children where the CSF was positive for oligoclonal bands, this was preceded by, or was observed at the same time as, an abnormal albumin ratio. Sixteen children (16/18) had elevated IFN-alpha levels in serum, or CSF, or in both. We conclude that these findings indicate an initial disruption of the blood-brain barrier followed by intrathecal antibody production by activated lymphocytes, clonally restricted to a few antigens. This is the first in vivo study to show this as an important pathogenetic mechanism of encephalitis in children. Poor outcome was associated with young age, a deteriorating electroencephalogram pattern from grade 1 to grade 2, and the degree of blood-brain barrier impairment, particularly when prolonged, but not with Glasgow Coma Scale score. The persistence of IFN-alpha was associated with a good prognosis.

Acute Disease↗
PubMed2006

Thoracic aneurysm rupture presenting as a rapidly enlarging neck mass.

A rapidly enlarging neck mass is an unusual clinical complaint at the emergency department. We report a case of an acute left neck swelling caused by a haematoma from a ruptured thoracic aneurysm. This resulted in dynamic airway distortion and obstruction and posed a great challenge to airway management.

Acute Disease↗
PubMed2005

Population-based study of the outcome following the prenatal diagnosis of cystic hygroma.

OBJECTIVE: To identify the population prevalence, pregnancy outcome, and the pattern of associated anomalies with a prenatal diagnosis of cystic hygroma. DESIGN: We analysed the pregnancy outcomes from 99 cases of prenatally diagnosed cystic hygroma reported to the Trent Congenital Anomalies Register from 1 January 1997 to 31 December 1999, by means of an outcome reporting form completed by the notifying centre. RESULTS: We identified a population prevalence of 1 in 1775 livebirths for prenatally diagnosed cystic hygroma. There were 64 terminations of pregnancy, 19 spontaneous pregnancy failures, and 16 livebirths. Of the 87 pregnancies karyotyped, 53 (61%) demonstrated aneuploidy with Turner syndrome being the most common, 29 (33%). There were a large variety of structural malformations identified, however, only 14 out of 83 terminations of pregnancy and spontaneous pregnancy failures had post-mortem examinations. Termination of pregnancy for Turner syndrome not complicated by identified structural malformations was the norm. Of the 16 livebirths, only 6 were normal at birth, 1 other has had successful hygroma surgery. Four of the liveborn infants have since died. CONCLUSIONS: The 'normal outcome' rate from pregnancies complicated by prenatally diagnosed cystic hygroma is less than 10% in this study (6/99). Prenatal diagnosis of cystic hygroma requires careful assessment of the fetus, with regard to both karyotyping and ultrasound. Post-mortem examination should be encouraged after termination of pregnancy, or spontaneous pregnancy loss. This is important not just to the current pregnancy but also for future pregnancies.

Adult↗
PubMed2005

Clinical and cost-effectiveness of a new nurse-led continence service: a randomised controlled trial.

BACKGROUND: Continence services in the UK have developed at different rates within differing care models, resulting in scattered and inconsistent services. Consequently, questions remain about the most cost-effective method of delivering these services. AIM: To evaluate the impact of a new service led by a continence nurse practitioner compared with existing primary/secondary care provision for people with urinary incontinence and storage symptoms. DESIGN OF STUDY: Randomised controlled trial with a 3- and 6-month follow-up in men and women (n = 3746) aged 40 years and over living in private households (intervention [n = 2958]; control [n = 788]). SETTING: Leicestershire and Rutland, UK. METHOD: The continence nurse practitioner intervention comprised a continence service provided by specially trained nurses delivering evidence-based interventions using predetermined care pathways. They delivered an 8-week primary intervention package that included advice on diet and fluids; bladder training; pelvic floor awareness and lifestyle advice. The standard care arm comprised access to existing primary care including GP and continence advisory services in the area. Outcome measures were recorded at 3 and 6 months post-randomisation. RESULTS: The percentage of individuals who improved (with at least one symptom alleviated) at 3 months was 59% in the intervention group compared with 48% in the standard care group (difference of 11%, 95% CI = 7 to 16; P<0.001) The percentage of people reporting no symptoms or 'cured' was 25% in the intervention group and 15% in the standard care group (difference of 10%, 95% CI = 6 to 13, P = 0.001). At 6 months the difference was maintained. There was a significant difference in impact scores between the two groups at 3 and 6 months. CONCLUSIONS: The continence nurse practitioner-led intervention reduced the symptoms of incontinence, frequency, urgency and nocturia at 3 and 6 months; impact was reduced; and satisfaction with the new service was high.

Adult↗
PubMed2003

Are gender differences in the relationship between self-rated health and mortality enduring? Results from three birth cohorts in Melton Mowbray, United Kingdom.

PURPOSE: The purpose of this study was to assess whether there is an enduring gender difference in the ability of self-rated health to predict mortality and investigate whether self-reported physical health problems account for this difference. DESIGN AND METHODS: Cox models for 4-year survival were fitted to data from successive cohorts aged 75-81 years registered with a primary care practice in the U.K. Midlands surveyed in 1981, 1988, and 1993-1995. RESULTS: Self-rated health was consistently a stronger predictor in men (hazard ratio [HR] = 2.7; 95% confidence interval [CI] = 2.1-3.5) than it was in women (HR = 1.9; 95% CI = 1.5-2.4). Women surveyed in 1993-1995 were more likely than men to report problems that were disabling but not life-threatening, whereas men were more likely to report potentially life-threatening problems. However, these differences did not explain the association of self-rated health with mortality. More than half of those who reported a potentially life-threatening problem said that their health was good. IMPLICATIONS: Self-rated health is more strongly associated with mortality in men, but this is unlikely to be explained by differences in the nature of their physical health problems.

Aged↗
PubMed2003

Active life expectancy in people with and without diabetes.

BACKGROUND: The aim of the study was to investigate the feasibility of monitoring older people's health by measuring active life expectancy among older people with and without diabetes using routinely collected primary care data. METHODS: The study comprised the first five rounds of a routine health assessment of those aged 75 years and over belonging to a large Midlands general practice (list size 32,500). A nurse carried out the health assessments in the participant's home. Being active was defined as the ability to perform (without difficulty, help or use of aids) at least six of seven activities of daily living (ADLs). Mortality data were collected through the practice register together with regular linkage to information from the Office for National Statistics. Period health expectancies were calculated for those known or found to be diabetic through the health assessments and for non-diabetic individuals. RESULTS: Calculation of active life expectancies (ALE) was based on 2,474 persons (212 with and 2,262 without diabetes). At all ages, people with diabetes had lower life expectancy and spent fewer years active. The proportion of remaining life spent active was, however, similar for both groups at younger ages, but by age 85 years people with diabetes spent only 32 per cent of remaining life active compared with 42 per cent for those without diabetes. CONCLUSION: Annual health assessments of the over-75s in primary care together with linkage to mortality data provide a feasible method of monitoring older people's health, particularly for subgroups at greater risk of disability. At Strategic Health Authority or Primary Care Trust level these methods can monitor health needs, highlight health inequalities and evaluate intervention strategies.

Activities of Daily Living↗
PubMed2002

Improving uptake of influenza vaccination among older people: a randomised controlled trial.

BACKGROUND: The uptake of influenza vaccination among older people is suboptimal. Contact with a doctor or nurse is associated with older people deciding to accept influenza vaccination. AIM: To compare different forms of approach in improving uptake of influenza vaccination among patients aged 75 years and over in primary care. DESIGN OF STUDY: Randomised controlled trial. SETTING: One large rural general practice serving the town and surrounding area of Melton Mowbray, Leicestershire. METHOD: All 2,052 patients aged 75 years and over, registered with the practice and not living in nursing/residential homes or sheltered accommodation, were included in the study. One-third of patients were randomised to receive an offer of influenza vaccination as part of an over-75 health check administered by a practice nurse in the patient's home, and two-thirds of patients were randomised to receive a personal letter of invitation to attend an influenza vaccination clinic held at the surgery. The main outcome measure was uptake of influenza vaccination. RESULTS: Six hundred and eighty patients were randomised to the health check arm of the trial and 1,372 were randomised to receive a personal letter. Of those randomised to the health check arm, 468 received the health check from the nurse. Overall, the difference in influenza vaccination uptake was 6.4% (95% confidence interval [CI] = 2.2% to 10.4%) with 67.9% (n = 932) of those who were sent a personal letter actually receiving the vaccine, compared with 74.3% (n = 505) of those offered a combined health check and influenza vaccination (P = 0.003). CONCLUSION: Combining home-based over- 75 health checks with influenza vaccination can improve uptake among older patients. However this intervention is likely to be costly and its effect on influenza vaccination rates is modest. The difference in uptake is greater among those who do not routinely comeforwardfor vaccination and a more viable option may be to target these patients.

Aged↗
PubMedDate not supplied

The Proseal LMA is a useful rescue device during failed rapid sequence intubation: two additional cases.

PURPOSE: We report two cases where the ProSeal laryngeal mask airway (PLMA) was successfully used as a rescue device, after failed tracheal intubation, during rapid sequence induction. CLINICAL FINDINGS: The first case involved a 31-yr-old primigravida presenting for emergency Cesarean section for severe fetal distress. She had a grade 3 larynx and airway edema was observed during laryngoscopy. Attempts with a McCoy blade and gum elastic bougie failed to secure the airway. A size 4 PLMA was inserted with good airway control and surgery proceeded uneventfully. The second case involved a 51-yr-old man presenting for appendectomy. Following failed attempts at intubation, a size 5 PLMA was successful in securing his airway and surgery proceeded uneventfully. CONCLUSIONS: The correctly placed PLMA has potential advantages over the cLMA for airway rescue in the circumstance of failed emergency intubation in a patient with a potentially full stomach. In the two cases reported, the PLMA provided effective rescue of the airway.

Adult↗