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Biomedical subjects

R Morgan

Publications and source records attributed to R Morgan.

At least 19 recordsLinked to original sources
PubMed2006

The Valiant thoracic endograft.

Thoracic aortic pathology is common, but conventional surgery carries with it a significant risk of mortality and morbidity due to thoracotomy, extensive surgical dissection, partial left lung collapse, proximal aortic cross-clamping and blood loss necessary for open thoracic aortic replacement. Endovascular techniques have the potential to remove much of this harm. However, endograft delivery to the thoracic aorta brings its own challenges; the graft and delivery system must be conformable to follow the aortic arch, flexible to track through tortuous calcified vessels, of low profile for access through the iliac arteries, and deploy accurately and with minimal force to avoid accidental side branch occlusion. The endoprosthesis must also prove to be durable. This paper reviews current indications for thoracic aortic stent grafts and the properties of an ideal endograft for deployment in the arch and descending aorta. The Medtronic Valiant TM endoprosthesis with Xcelerant TM Delivery System is a third-generation system designed specifically for the treatment of a range of thoracic aortic pathologies, including but not exclusively, aneurysms and dissections. The design of the Valiant endoprosthesis and delivery system are described in detail, and compared to the second-generation Talent system. Our early experience of using Valiant in 28 patients with a range of pathologies is described. The graft achieved an initial technical success in 93% and was easy to position and deploy. Long-term data is now required; the Virtue Registry is a prospective multicenter European registry collecting clinical and health economics data on Valiant in the management of aortic dissections.

Aortic Dissection↗
PubMed2005

Comparison of particle penetration with non-spherical polyvinyl alcohol versus trisacryl gelatin microspheres in women undergoing premyomectomy uterine artery embolization.

AIM: The purpose of this study was to compare the depth of vascular penetration of non-spherical polyvinyl alcohol (PVA) versus trisacryl gelatin microspheres (MS) in women undergoing uterine artery embolization (UAE) immediately before transabdominal myomectomy. MATERIALS AND METHODS: A total of 17 patients who had been referred for embolization before myomectomy underwent bilateral uterine artery embolization using either 355-500 microm PVA (group A) or 700-900 microm MS (group B). The depth of penetration of the particles was assessed by identifying their presence and location in the resected specimen. RESULTS: Of the 17 women enrolled in this study, 10 were in group A and 6 in group B. One woman underwent embolization using both types of particle and was excluded from the analysis. Embolic particles were significantly (p = 0.048) more frequently located within the fibroid (4/6, 67%) in Group B than Group A (1/10, 10%). Particles were also identified in the perifibroid tissues in 4/6 (67%) in Group B and 4/10 (40%) in Group A, with no statistical difference. There were no procedural complications. CONCLUSION: MS particles (700-900 microm) penetrate significantly deeper into leiomyomata compared with non-spherical PVA (355-500 microm). MS may therefore confer advantages in UAE, as they may more specifically target the fibroid, allowing an earlier end-point to embolization and minimizing ischaemic damage to normal myometrium and ovaries.

Acrylic Resins↗
PubMed2005

Neuroanaesthetists' experience of workload-related issues and long-duration cases.

A survey of the members of the Neuroanaesthesia Society of Great Britain and Ireland was conducted to examine issues arising from the management of long cases. Replies were received from 47% of neuroanaesthetists. The survey highlights that consultants are working for prolonged periods without adequate rest. This may compromise patient safety, job satisfaction and recruitment to the specialty. These pressures are likely to increase as the European Working Time Directive reduces the availability of trainees, and because of expansion in neurosurgery and neuroradiology. Similar concerns are likely to extend into other anaesthetic specialties with long-duration cases and may apply to our surgical colleagues.

Anesthesiology↗
PubMed2005

Endovascular stent graft repair of mycotic aneurysms of the thoracic aorta.

Traditional open surgical repair for mycotic aneurysms of the thoracic aorta is associated with significant morbidity and mortality. Endovascular repair has been reported as an alternative treatment in patients with mycotic thoracic aneurysms. This article reports our experience of endovascular stent graft placement in three patients with mycotic aneurysms of the thoracic aorta and compares the results with similar reports on the literature.

Aged↗
PubMed2004

A placebo-controlled crossover study comparing the effects of nateglinide and glibenclamide on postprandial hyperglycaemia and hyperinsulinaemia in patients with type 2 diabetes.

AIM: This was a randomized, double blind, three period crossover study. The objective was to compare glucose, insulin and C-peptide 24 h profiles in patients with type 2 diabetes mellitus after dosing with nateglinide (given preprandially before three test meals), glibenclamide (administered once before breakfast) or placebo (given before three test meals). METHODS: Fourteen patients underwent screening followed within 3 weeks by three treatment periods of 1 day, each separated by 7 days. Dosing followed a six-sequence balanced, two 3 x 3-replicated Latin square. RESULTS: Mean peak serum insulin levels were lower after nateglinide (115 mU/l) than after glibenclamide (145 mU/l.h; p = 0.017) but higher than after placebo (79 mU/l; p = 0.001). However, peak insulin levels were reached earlier after nateglinide [mean time to peak (tmax) 1.7 h] compared to glibenclamide (mean tmax 2.1 h, p = 0.06). Total insulin exposure over the day was higher after glibenclamide compared with that following nateglinide (1216 vs. 1067 mU/l.h; p = 0.009). Similar findings were seen with serum C-peptide. Despite this, mean peak plasma glucose concentrations were lower following nateglinide (11.4 mmol/l from a baseline of 8.3 mmol/l) compared with glibenclamide (13.2 mmol/l from a baseline of 8.5 mmol/l; p = 0.001) and placebo (14.0 mmol/l from a baseline of 8.0 mmol/L; p < 0.001). CONCLUSIONS: Nateglinide improves early prandial measures of insulin and glucose response to a standard meal, more so than glibenclamide, in people with type 2 diabetes.

Aged↗
PubMed2003

The use of stent grafts for the treatment of aneurysms and dissections of the thoracic aorta: a single centre experience.

OBJECTIVE: To review the results of stent graft treatment for diseases of the thoracic aorta. DESIGN: A retrospective study of the results of thoracic stent graft procedures in a single centre. METHODS: The results of 30 procedures performed in 24 patients were analysed. Eleven patients had aneurysmal dilatation of the descending thoracic aorta (>5.5 cm), nine patients had complicated type B dissection, three had penetrating ulcers and one had a traumatic pseudoaneurysm. Imaging follow-up consisted of CT scans performed at one, three, six and 12 months following the procedure and annually thereafter. RESULTS: One technical failure occurred due to a ruptured external iliac artery. There were no other immediate failures. The primary technical success rate was 83%. The 30-day procedural and patient mortality rates were 7 and 8%, respectively. No neurological complications occurred. Seven patients had the subclavian artery covered without complications. Secondary intervention was required in 21%. During the follow-up period (mean 11 months, range 1-48 months.) there were five deaths, two of which were related to stent graft infection. CONCLUSION: Thoracic stent grafts offer a realistic alternative to surgery.

Aged↗
PubMed2003

A modification to the experimental gingivitis protocol to compare the antiplaque properties of two toothpastes.

BACKGROUND AND AIMS: Randomised, blind, controlled experimental gingivitis and home-use study protocols are used to evaluate the efficacy of oral hygiene products. The present methodological study combined the two clinical trial designs to compare the preventive and therapeutic potentials of two toothpastes. MATERIAL AND METHODS: The study was a parallel group, randomised, double-blind design, initially involving 73 healthy dentate subjects. A 21-day experimental gingivitis protocol was combined with a 6-week (42 days) home-use protocol. At baseline, modified gingival index (MGI), gingival index (GI) and gingival bleeding (GB) were recorded. A dental prophylaxis was then performed. Subjects were allocated to either control fluoride or stannous fluoride toothpaste based on gender and GI. During the first 21-day period, subjects applied the allocated toothpaste, for 1 min twice a day, to a group of teeth in a plastic shield and brushed the remaining teeth with the same paste. From day 21 the shield was not placed, and subjects brushed all teeth with the toothpaste for 1 min twice per day up to day 42. MGI, GB and a plaque index (PI) were recorded on days 21 and 42. RESULTS: Sixty-nine and 67 subjects completed to days 21 and 42, respectively. For shielded teeth, PI, MGI and GB increased to day 21 and then after ceasing the use of the shield decreased to day 42. At day 21, PI favoured the stannous fluoride toothpaste, but differences did not achieve statistical significance for any parameter at days 21 or 42. For unshielded teeth, there were no significant differences between the toothpastes for any parameter at either time point. CONCLUSION: : The feasibility of combining two gingivitis clinical trial methodologies appears proven, and data on both the preventive and therapeutic chemical and mechanical efficacy of toothpastes can be obtained through such protocols. Specifically from the present study and consistent with some other reports, the plaque inhibitory properties of the stannous fluoride product are limited and do not always translate into an antiplaque/antigingivitis effect.

Adult↗
PubMed2003

Carotid endarterectomy in patients aged 75 and over: early results and late outcome.

BACKGROUND: The mean age of patients in the European Carotid Surgery Trial with greater than 70% stenosis was 62 years. With changing demographics older patients are increasingly being referred for carotid endarterectomy (CEA). OBJECTIVES: To assess the complications and survival (stroke-free and overall) of patients over the age of 75 undergoing CEA. METHODS: Analysis of a database, clinical records and cause of death of patients undergoing CEA in a single regional unit over a 7 year period (1/4/1993 until 1/4/2000), with follow-up to April 2002. The rates of further neurological events were obtained from the Scottish Morbidity Record 1 (SMR 1) of hospital discharges. Patients referred from outside the region were excluded. Differences between groups were assessed by the Chi-squared test, with Yates correction and log-rank tests. RESULTS: Of the 235 patients undergoing CEAs, 55 (23%) were 75 years or older. The post-operative neurological complication rate was 1.7% in the under 75's and 5.4% in the older group (p < 0.05). The 30 day mortality was 1.1% (two patients) and 1.8% (one patient) respectively. The Kaplan-Meier estimated survival for the under 75's and older were 93 and 75% at 3 years and 80 and 59% at 5 years respectively (p < 0.001). The Kaplan-Meier estimated neurological event-free 5 year survival for the under 75's and older patients were 96 and 82% respectively (p < 0.001). CONCLUSION: CEA in patients aged 75 years and over is associated with a significantly increased risk of stroke and death. CEA may not benefit elderly patients with a reduced life expectancy.

Age Factors↗
PubMed2002

Predictors of long-term outcome following high-dose chemotherapy in high-risk primary breast cancer.

We report on a predictive model of long-term outcome in 114 high-risk breast cancer patients treated with high-dose chemotherapy between 1989 and 1994. Paraffin-blocks from 90 of the 114 primaries were assessed for the presence of five risk factors: grade, mitotic index, protein expression of p53, HER2/neu, and oestrogen/progesterone receptor status; we could analyse the effect of risk factors in 84 of these 90 tumours. Seven-year relapse-free and overall survival was 58% (95% confidence interval 44-74%) and 82% (95% confidence interval 71-94%) vs 33% (95% confidence interval 21-52%) and 41% (95% confidence interval 28-60%) for patients whose primary tumours displayed > or =3 risk factors vs patients with < or =2 risk factors. For the entire group of 168 high-risk breast cancer patients, inflammatory stage IIIB disease and involved post-mastectomy margins were associated with decreased relapse-free survival and overall survival; patients treated with non-doxorubicin containing standard adjuvant therapy experienced worse overall survival (RR, 2.08; 95% confidence interval 1.04 to 4.16; P=0.04), while adjuvant tamoxifen improved overall survival (RR, 0.65; 95% confidence interval 0.41-1.01; P=0.054). Future trial designs and patient selection for studies specific for high-risk breast cancer patients should include appropriate prognostic models. Validation of such models could come from recently completed randomised, prospective trials.

Adult↗
PubMed2002

Survey of junior hospital doctors' attitudes to cardiopulmonary resuscitation.

Most cardiac arrest teams are made up of junior doctors. The stressful effect of cardiopulmonary resuscitation (CPR) on doctors has not previously been established. A questionnaire was sent to all 52 junior doctors who participated in the cardiac arrest team at a district general hospital. Forty one questionnaires were returned by 22 junior house officers, 12 senior house officers, and seven specialist registrars. The questionnaire was anonymous so non-responders could not be recontacted. Seventy three per cent found CPR stressful. The main reason for stress was the inappropriateness of CPR on the individual patient (12), poor outcome (13), no advanced life support (ALS) course (4), and the procedure itself (4). Fifty four per cent felt the number of inappropriate CPR had increased in the last six months with the main reason given (48%) being failure of senior staff to make "do not resuscitate" orders. Ninety seven per cent felt some CPRs were inappropriate; 70% felt a debriefing session should occur after CPR, while 88% reported not having one. Seventy six per cent felt competent at performing CPR, 22% felt incompetent of whom none had undergone ALS training. Fifty eight per cent found it difficult to discuss CPR with patients; 46% found it difficult to discuss CPR with relatives. Most junior doctors feel stress from CPR. Adequate review by senior doctors with documentation of do not resuscitate orders where appropriate, after discussion with patients, might be beneficial. Adequate training, improving communication skills, and support for junior doctors in the cardiac arrest team need to be reviewed since improvement in these areas may reduce stress.

Attitude of Health Personnel↗
PubMed2002

Oral candidiasis.

Oral candidiasis is a common opportunistic infection of the oral cavity caused by an overgrowth of Candida species, the commonest being Candida albicans. The incidence varies depending on age and certain predisposing factors. There are three broad groupings consisting of acute candidiasis, chronic candidiasis, and angular cheilitis. Risk factors include impaired salivary gland function, drugs, dentures, high carbohydrate diet, and extremes of life, smoking, diabetes mellitus, Cushing's syndrome, malignancies, and immunosuppressive conditions. Management involves taking a history, an examination, and appropriate antifungal treatment with a few requiring samples to be taken for laboratory analysis. In certain high risk groups antifungal prophylaxis reduces the incidence and severity of infections. The prognosis is good in the great majority of cases.

Antifungal Agents↗
PubMed2001

Twice-weekly paclitaxel and weekly carboplatin with concurrent thoracic radiation followed by carboplatin/paclitaxel consolidation for stage III non-small-cell lung cancer: a California Cancer Consortium phase II trial.

PURPOSE: Recent studies have suggested the superiority of concurrent chemoradiotherapy and the efficacy of paclitaxel/carboplatin in advanced non-small-cell lung cancer (NSCLC). In view of those results, we sought to examine the safety and efficacy of administration of radiosensitizing paclitaxel twice weekly and carboplatin weekly with concurrent thoracic radiation therapy (XRT) followed by consolidation paclitaxel and carboplatin for stage III NSCLC in a multi-institutional phase II trial. PATIENTS AND METHODS: Induction chemoradiotherapy consisted of paclitaxel 30 mg/m2 delivered intravenously (IV) for 1 hour twice weekly for 6 weeks, carboplatin at a dose based on an area under the concentration-time curve (AUC) of 1.5 mg/mL x min, given IV once weekly for 6 weeks, and concomitant XRT of 1.8 to 2.0 Gy daily for a total of 61 Gy. Patients who achieved a complete response, partial response, or stable disease received two 21-day cycles of consolidation chemotherapy consisting of paclitaxel 200 mg/m2 IV for 3 hours and carboplatin at a dose based on an AUC of 6 mg/mL x min. RESULTS: Thirty-four patients were eligible. Their median age was 62 years (range, 39 to 73 years), 59% were female, 41% were male, 94% had a performance status of 0 or 1, 38% had stage IIIA NSCLC, and 62% had stage IIIB NSCLC. Common grade III and IV toxicities during the induction chemoradiation phase included esophagitis (38%) and neutropenia (12%). The most common adverse reaction during consolidation chemotherapy was grade III neutropenia in five patients (15%). The overall response rate was 71%, which was achieved in the induction phase. The median follow-up was 20 months, the median survival was 17 months, and 2-year actuarial survival rate was 40% (95% confidence interval, 20% to 65%). CONCLUSION: This regimen is tolerable and results are promising. We recommend further evaluation of this regimen in a phase III trial.

Adult↗
PubMed2001

Downstream of Otx2, or how to get a head.

Otx2 is a member of a highly conserved family of homeodomain-containing transcription factors that function in early brain development. Recent studies have identified a significant number of target genes downstream of Otx2, allowing us to address the question of how it fulfils its diverse developmental roles. Interestingly, many of these target genes are not transcription factors or signaling molecules, and they probably have no direct affect on gene expression. Furthermore, there is evidence that Otx2 coordinates the activity of unrelated genes that have overlapping functions, and that it does so directly without intermediate transcriptional or signaling activity.

Animals↗
PubMed2001

The circadian gene Clock is restricted to the anterior neural plate early in development and is regulated by the neural inducer noggin and the transcription factor Otx2.

The circadian cycle is a simple, universal molecular mechanism for imposing cyclical control on cellular processes. Here we have examined the regulation of one of the key circadian genes, Clock, in early Xenopus development. We find that the expression of Clock is dependent on developmental stage, not on time per se, and is mostly restricted to the anterior neural plate. It's expression can be induced by the secreted polypeptide noggin, and subsequently upregulated by Otx2, a transcription factor required for the determination of anterior fate.

Animals↗