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Biomedical subjects

P Bolton

Publications and source records attributed to P Bolton.

At least 19 recordsLinked to original sources
PubMed2006

Influence of innocuous cervical vertebral movement on the efferent innervation of the adrenal gland in the rat.

In general, in central nervous system intact anesthetized animals, adrenal sympathetic efferent nerve activity and catecholamine secretion increase in response to noxious somatic stimulation, and decrease in response to innocuous somatic stimulation. In anesthetized rats, noxious chemical stimulation of the thoracic and lumbar interspinous tissues is associated with large increases in adrenal sympathetic efferent nerve activity and catecholamine secretion, with a clear segmental organization to the reflex apparent in spinalized animals. However, the adrenal sympathetic nerve responses to mechanical stimulation in the form of pressure applied laterally to the lower thoracic and lower lumbar vertebrae do not display segmental organization, and the depressor response is more characteristic of responses to innocuous somatic stimulation despite the use of large forces (up to 3.0 kg). Therefore, we sought to determine whether innocuous movements of the mechanoreceptor-rich deep tissues of the neck modulate the sympathetic outflow to the adrenal gland. We performed experiments in 14 anaesthetised (Urethane 1 g/kg and Chloralose 0.1 g/kg) adult rats. Rats were intubated and breathed spontaneously. A computer driven small animal manipulator was used to impose ramp and hold rotational displacements (12 degrees /s, hold duration 2 s) of the 2nd cervical vertebra (range 2-30 degrees ) while recording multi-unit activity from sympathetic nerves innervating the adrenal gland. While noxious forepaw pinch elicited an increase in sympathetic nerve activity to the adrenal gland, there was no significant change in sympathetic nerve activity with small (2 degrees or 6 degrees ) rotations. Significant changes (P<0.05) in sympathetic activity were observed in only 7% (n=21) of all trials at larger displacements (12 degrees , 20 degrees , 25 degrees , 30 degrees n=287 trials). Our data suggest that although noxious stimuli may modulate sympathetic outflow, it is rare for afferents signalling innocuous cervical vertebral movements to modulate sympathetic nerves innervating the adrenal gland.

Adrenal Glands↗
PubMed2004

Future possibilities of the Linac Coherent Light Source.

A study of the potential for the development of the Linac Coherent Light Source (LCLS) beyond the specifications of the baseline design is presented. These future developments include delivery of X-ray pulses in the 1 fs regime, extension of the spectral range, increase of the FEL power, exploitation of the spontaneous emission, and a more flexible time structure. As this potential is exploited, the LCLS can maintain its role as a world-leading instrument for many years beyond its commissioning in 2008 and initial operation as the world's first X-ray free-electron laser.

Journal Article↗
PubMed2004

How do Africans view the impact of HIV? A report from a Ugandan community.

Although much research has been conducted on the causes and outcomes of HIV, far less has been written about how the affected societies themselves perceive the epidemic. This is particularly true in sub-Saharan Africa. In this study we interviewed 50 residents (28 female, 22 male) from 30 villages across the Rakai and contiguous portion of the Masaka districts in southwest Uganda about the problems affecting their communities as a result of HIV. These problems formed three main categories: (1) lack of able-bodied adults, (2) lack of care for children, and (3) mental and social problems. The interrelatedness of these categories is discussed in the context of communities that are struggling to recover from the effects of HIV.

Adult↗
PubMed2004

The relation of infantile spasms, tubers, and intelligence in tuberous sclerosis complex.

BACKGROUND: The aetiology of the learning difficulty in tuberous sclerosis is debated. It may be related to the amount of tubers in the brain or caused by the infantile spasms that occur in early life. AIMS: To examine the relative contributions to final intelligence (IQ) made by both cerebral tubers and infantile spasms. METHODS: As part of an epidemiological study of tuberous sclerosis in the south of England, patients were recruited who were able to undergo magnetic resonance imaging (MRI) without the need for an anaesthetic. Epilepsy history was determined by interview and review of clinical records. IQ was assessed using either Wechsler intelligence scales or Raven's matrices. RESULTS: A total of 41 patients consented to have an MRI scan. IQ scores were normally distributed about a mean of 91. Twenty six patients had a positive history of epilepsy, and 11 had suffered from infantile spasms. There was a significant relation between the number of tubers and IQ. Infantile spasm status partly confounded the relation between tubers and IQ, but did not render the relation statistically insignificant. The relation between infantile spasms and learning difficulty remained strong even when controlling for the number of tubers.

Adolescent↗
PubMed2004

Training opportunities for specialist registrars post-calmanization: audit of trainees' exposure to repair of the tympanic membrane.

Specialist training at the registrar grade in the United Kingdom has undergone significant change in the recent past. One of the effects has been a reduction in the length of time spent in training. This and the application of the European working time directive have the potential to reduce trainees' surgical exposure. The proportion of tympanic membrane procedures performed by reconstructive otolaryngology registrars in the Grampian University hospitals was audited to monitor the impact of these changes. Case notes of all patients who underwent myringoplasty or tympanoplasty between July 1998 and June 1999 were analysed retrospectively. Details of the surgeons' grade were recorded. The proportion of myringoplasties performed by registrars as determined by the Royal College of Surgeons of England National Comparative Audit survey, carried out in 1995 before the widespread implementation of recommended changes in otolaryngology registrar training, was set as the gold standard. In the period July 1998-1999 registrars had performed fewer myringoplasties than the standard, 17 per cent versus 34.2 per cent respectively (p = 0.035). A strategy to increase registrar exposure to myringoplasty surgery was then adopted by the department and the proportion of myringoplasties performed by registrars re-audited prospectively. The proportion of myringoplasties undertaken by registrars increased in the period January 2001 to July 2001 compared to July 1998-1999, 53 per cent versus 17 per cent respectively (p < 0.0007). Changes in working practice can address shortfalls in registrars' exposure to surgical procedures.

Education, Medical, Graduate↗
PubMed2003

Anaesthesia for an adolescent with mitochondrial encephalomyopathy-lactic acidosis-stroke-like episodes syndrome.

Anaesthesia for patients with mitochondrial disorders occurs with regularity, either for a diagnostic or therapeutic procedure associated with the syndrome or for unassociated surgery. We report the case of a 17-year-old boy with mitochondrial encephalomyopathy-lactic acidosis-stroke-like episodes (MELAS) syndrome who underwent a laparotomy for fundoplication. The potential hazards of anaesthesia for this patient, and the steps taken to avoid them, are discussed.

Adolescent↗
PubMed2001

Observation of plasma focusing of a 28.5 GeV positron beam.

The observation of plasma focusing of a 28.5 GeV positron beam is reported. The plasma was formed by ionizing a nitrogen jet only 3 mm thick. Simultaneous focusing in both transverse dimensions was observed with effective focusing strengths of order tesla per micron. The minimum area of the beam spot was reduced by a factor of 2.0+/-0.3 by the plasma. The longitudinal beam envelope was measured and compared with numerical calculations.

Journal Article↗
PubMed2001

Ease of laryngeal passage during fibreoptic intubation: a comparison of three endotracheal tubes.

BACKGROUND: The use of a fibreoptic bronchoscope to facilitate endotracheal intubation is well established in modern anaesthetic practice. Difficulty may be encountered when inserting an endotracheal tube over the fibrescope as the bevelled tip can impinge on the vocal cords or epiglottis and impede advancement through the laryngeal inlet. Intavent have recently developed a tapered tip tube for use with their Intubating Laryngeal Mask Airway. A randomised, double-blind study was performed to compare the ease of railroading three different tubes over a fibrescope placed in the trachea. METHODS: We studied 54 patients presenting for elective dental surgery. General anaesthesia was induced with propofol 2-3 mg/kg, fentanyl 1-1.5 microg/kg, and atracurium 0.5 mg/kg and maintained with oxygen (5 l/min) and isoflurane 1-2%. Nasotracheal fibreoptic intubation was attempted in all patients. In each case the ease of tube advancement over the fibrescope and into the trachea was evaluated by the blinded observer, using the classification system (Grade 0-2) described by Jones et al. RESULTS/CONCLUSION: The Intavent tube was found to be superior for nasotracheal fibreoptic intubation to either the Mallinckrodt reinforced tube (P<0.034) or the Portex Blue Line tube (P<0.004).

Adolescent↗
PubMed2001

A quality assurance activity to improve discharge communication with general practice.

The aim of this study was to describe and evaluate a method of improving the completion of discharge summary information. As a quality assurance activity, a self-carbonating form for both the patient record and discharge letter was introduced to a general practice casualty (GPC) in Sydney, Australia, involving approximately 40 community GPs. Evaluation involved assessment of the change associated with this intervention on a cohort of GPs using logistic regression analysis, clustering at the level of the treating GP. The main outcome measure was completion of a discharge letter to the patient's usual GP. Provision of discharge letters increased from 30% prior to the intervention to 90% following it (P< 0.0005; OR 11.9; 95% CI 8.6-16.4). It was concluded that solutions to problems of quality are best developed at the system level. The use of a self-carbonating form to simultaneously generate a discharge letter and the medical record might be used by other similar services with good effect.

Australia↗
PubMed2001

The reasons for, and lessons learned from, the closure of the Canterbury GP After-Hours Service.

This paper describes a trial of the Canterbury GP After-Hours Service (CGPAHS), a GP staffed after-hours service within the Canterbury Hospital Emergency Department. It was decided not to continue the service beyond the twelve-month trial phase because the opportunity cost to do this was greater than existing alternative services. The efficiency of the service might have been improved had greater numbers of patients been referred to it, either from the adjacent emergency department or the local community. Reasons why the trial was not able to realise these efficiencies are explored.

Community-Institutional Relations↗
PubMed2001

Collaborating to manage polypharmacy.

DiNCQUMGP (Divisions National Consortium for the Quality Use of Medicines in General Practice) reports on a collaboration between doctors, pharmaceutical companies, government agencies, and medicine users to manage polypharmacy (prescribing multiple medicines to a patient) amongst older people. We have reported the outcomes of our collaboration (improving the Quality Use of Medicines) elsewhere. Here we discuss how we worked together, opened up new opportunities, and learned from one another. The first part of this article outlines a constructive new way of thinking about collaborating, that we argue is fundamentally different from current approaches. The second part describes what we did in the words of those involved.

Cooperative Behavior↗
PubMed2001

Cross-cultural validity and reliability testing of a standard psychiatric assessment instrument without a gold standard.

The objective of this study was to assess the cross-culture validity and reliability of a standard psychiatric assessment instrument without the usual "gold standards." Normally criterion validity testing requires comparison with such a standard--usually another instrument or a professional diagnosis. Instead local informants identified persons with and without "agahinda gakabije" (a locally described grief syndrome) who were then asked if they thought they had this syndrome and also interviewed using the depression section of the Hopkins Symptom Checklist (DHSCL). To assess criterion validity, interviews where respondent and informant agreed on the presence or absence of agahinda gakabije were compared with depression diagnosis using the DHSCL. We also assessed construct validity (using factor analysis), internal reliability (Cronbach's alpha), and test-retest reliability using results from a subsequent community-based survey employing the DHSCL. We found a similar relationship between depression and agahinda gakabije as between depression and grief in western countries, which supports criterion validity. Construct validity and internal reliability were good (Cronbach's alpha = 0.87). Test-retest reliability of a DHSCL-based scale was less adequate (0.67). Although not replacing the usual gold standards for testing criterion validity, this approach may prove useful where these standards are unavailable. As this includes much of the developing world, this could result in more accurate mental health assessments among populations for whom this has hitherto not been possible.

Adult↗
PubMed2001

Local perceptions of the mental health effects of the Rwandan genocide.

The objectives of this study were to investigate how Rwandans perceive the mental health effects of the 1994 genocide, to investigate the local validity of western mental illness concepts, and (if these concepts were found to be valid) to provide data to adapt existing mental health assessment instruments for local use. We used three ethnographic methods to interview people in two rural areas in Rwanda: first, free listing provided a list of local terms for mental symptoms and disorders; second, key informant interviews then provided more detailed information about these disorders; and finally, pile sorts confirmed the relationships among symptoms and disorders that emerged from the other methods. We found that interviewees described the diagnostic symptoms of depression and posttraumatic stress disorder as results of the genocide and also described associated "local" symptoms not included in the established diagnostic criteria. They divided symptoms into a "mental trauma" syndrome that included the posttraumatic stress disorder symptoms and some depression and local symptoms, and a grief syndrome that included other depression and local symptoms. In the pile sorts, we focused on investigating mood disorders and confirmed that four of the locally described symptoms formed part of a local depression-like illness. The results suggest that depression occurs among this population and support the local content validity of depression assessment instruments, such as the Depression section of the Hopkins Symptom Checklist. Similar independent evidence of validity is missing from most cross-cultural surveys. Our work supports the need and feasibility for collecting this supporting evidence prior to conducting cross-cultural surveys using existing instruments.

Anthropology, Cultural↗
PubMed2001

Clinical findings of the second 1000 UK Gulf War veterans who attended the Ministry of Defence's Medical Assessment Programme.

OBJECTIVE: To review the diagnoses made in the second 1000 veterans of the Gulf conflict 1990-91 seen in the Ministry of Defence's Gulf Veterans' Medical Assessment Programme and to determine the main conditions related to Gulf service. DESIGN: Case series of 1000 consecutive Gulf veterans who presented to the programme between 25 February 1997 and 19 February 1998. SUBJECTS: Gulf War veterans. MAIN OUTCOME MEASURES: Assessment of the patient's health status. Diagnosis of medical and psychiatric conditions using ICD-10. RESULTS: 204 patients were unwell. 309 patients had organic disease, of whom 248 were well, 252 had psychiatric conditions which remained active in 173. The remaining 79, now well, had had psychiatric disorders following Gulf service. The principal psychiatric diagnosis was post traumatic stress disorder and the majority arose as a result of Gulf service. CONCLUSION: 796 (80%) veterans were well. There were 309 (31%) patients with organic disease. 252 (25%) veterans had psychiatric conditions of which 173 (69%) had an active diagnosed disorder and post traumatic stress disorder was the predominant condition. The pattern of disease is similar to that seen in NHS practice. We found, like others, no evidence to support a unique Gulf War syndrome. Post conflict illnesses have many common features.

Adult↗