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S Macdonald

Publications and source records attributed to S Macdonald.

At least 19 recordsLinked to original sources
PubMed2006

Survey of pigs' kidneys with lesions consistent with PMWS and PDNS and ochratoxicosis. Part 1: concentrations and prevalence of ochratoxin A.

One thousand condemned pigs' kidneys were collected in February 2002 from two pig abattoirs in England to assess the possible contribution of ochratoxicosis to postweaning multisystemic wasting syndrome (PMWS) and porcine dermatitis and nephropathy syndrome (PDNS); 250 of the kidneys with macroscopic lesions consistent with nephrosis/nephritis (pale or white cortical lesions) were selected, and the concentration of ochratoxin A was measured in samples of renal cortex by high-performance liquid chromatography (HPLC). Low concentrations were detected in 230 (92 per cent) of the kidneys tested, and in 41 (16.4 per cent) of them the concentration was below the limit of quantification of 0.2 microg/kg. In 187 (74.8 per cent) of the kidneys, the concentration was more than 0.2 microg/kg, and the highest concentration detected was 2.3 microg/kg. The mean (sd) concentration was 0.31 (0.33) microg/kg. The identification of ochratoxin A was confirmed by mass spectrometry. The concentrations of ochratoxin A did not exceed the threshold assessed by the Food Standards Agency to be safe for human food.

Animals↗
PubMed2006

Systematic review of factors influencing patient and practitioner delay in diagnosis of upper gastrointestinal cancer.

As knowledge on the causation of cancers advances and new treatments are developed, early recognition and accurate diagnosis becomes increasingly important. This review focused on identifying factors influencing patient and primary care practitioner delay for upper gastrointestinal cancer. A systematic methodology was applied, including extensive searches of the literature published from 1970 to 2003, systematic data extraction, quality assessment and narrative data synthesis. Included studies were those evaluating factors associated with the time interval between a patient first noticing a cancer symptom and presenting to primary care, between a patient first presenting to primary care and being referred to secondary care, or describing an intervention designed to reduce those intervals. Twenty-five studies were included in the review. Studies reporting delay intervals demonstrated that the patient phase of delay was greater than the practitioner phase, whilst patient-related research suggests that recognition of symptom seriousness is more important than recognition of the presence of the symptom. The main factors related to practitioner delay were misdiagnosis, application and interpretation of tests, and the confounding effect of existing disease. Greater understanding of patient factors is required, along with evaluation of interventions to ensure appropriate diagnosis, examination and investigation.

Attitude to Health↗
PubMed2006

Is there any evidence that cerebral protection is beneficial? Experimental data.

This article presents the available experimental data from the world literature on the use of cerebral protection devices during carotid artery stenting (CAS). Clinical studies relying on surrogate markers of cerebral embolisation in place of neurological event rate as primary outcome measures are evaluated alongside bench-top and animal studies. These surrogate markers include evaluations of outcomes using procedural transcranial Doppler (TCD) and diffusion-weighted magnetic resonance imaging of brain (DWI). Pathological analyses of debris retrieved from in-vivo analyses of protection devices are also included in this review because although the focus of these studies was primarily clinical, the laboratory data will be preferentially presented and it provides interesting insights. It can be shown that each of the three philosophies of cerebral protection, namely flow arrest (proximal or distal), flow reversal and distal filtration is capable of the entrapment of sizeable debris that would logically threaten devastating stroke if it embolized to the brain. Whilst balloon occlusion significantly reduces the procedural microembolic load (particles less than 60 mm) and flow reversal may be the first means to entirely eliminate it, filters may be associated with increased microembolization. This has been described by some workers as controlled embolization. Certainly, particles smaller than the pore size of currently available filters (60-140 mm) will readily evade capture due to filter periflow and through-flow. There is evidence to suggest that tens of thousands of particles of this size may be released during CAS and there is some evidence that this may be associated with more new white lesions on DWI of brain. The clinical consequences of this controlled embolization however, remain unclear and sophisticated neuropsychometric test batteries may need to be applied at later time points to detect subtle injury that may be compounded by a late inflammatory response around cerebral emboli. Devices relying on placement in the distal internal carotid artery (ICA) for establishment of protection risk intimal damage and the release of microemboli due largely to device deployment and retrieval. Although devices effecting flow arrest and flow reversal will limit all embolization, they do so at the expense of constant procedural cerebral perfusion and may not be tolerated in patients with precarious cerebral reserve capacity, loss of integrity of the Circle of Willis and/or high-grade stenosis of the contralateral ICA. Advances in the concept of cerebral protection will require technical refinements to existing devices, alternative mechanical strategies and/or pharmacological plaque stabilization.

Angioplasty↗
PubMed2005

Treatment of active Crohn's disease in children using partial enteral nutrition with liquid formula: a randomised controlled trial.

BACKGROUND AND AIMS: Total enteral nutrition (TEN) with a liquid formula can suppress gut inflammation and induce remission in active Crohn's disease. The mechanism is obscure. Studies have suggested that long term nutritional supplementation with a liquid formula (partial enteral nutrition (PEN)) may also suppress inflammation and prevent relapse. The aim of this study was to compare PEN with conventional TEN in active Crohn's disease. PATIENTS AND METHODS: Fifty children with a paediatric Crohn's disease activity index (PCDAI)>20 were randomly assigned to receive 50% (PEN) or 100% (TEN) of their energy requirement as elemental formula for six weeks. The PEN group was encouraged to eat an unrestricted diet while those receiving TEN were not allowed to eat. The primary outcome was achievement of remission (PCDAI<10). Secondary analyses of changes in erythrocyte sedimentation rate (ESR), C reactive protein, albumin, and platelets were performed to look for evidence of anti-inflammatory effects. RESULTS: Remission rate with PEN was lower than with TEN (15% v 42%; p=0.035). Although PCDAI fell in both groups (p=0.001 for both), the reduction was greater with TEN (p=0.005). Moreover, the fall in PCDAI with PEN was due to symptomatic and nutritional benefits. With both treatments there were significant improvements in relation to abdominal pain, "sense of wellbeing", and nutritional status. However, only TEN led to a reduction in diarrhoea (p=0.02), an increase in haemoglobin and albumin, and a fall in platelets and ESR. CONCLUSIONS: TEN suppresses inflammation in active Crohn's disease but PEN does not. This suggests that long term nutritional supplementation, although beneficial to some patients, is unlikely to suppress inflammation and so prevent disease relapse.

Adolescent↗
PubMed2004

Is the endovascular treatment of carotid stenosis in high-risk patients really safer than carotid endarterectomy?

BACKGROUND: We assess the outcomes of patients who would have been considered at high-risk from carotid endarterectomy (CEA), who have undergone endovascular treatment. METHODS: High-risk patients were classed as those with occlusion of the contralateral internal carotid artery, recurrent stenosis following CEA, stenosis secondary to neck irradiation or treatment prior to coronary bypass surgery. RESULTS: 103 procedures fulfilled at least one inclusion criterion. 58.3% had symptomatic disease. The all stroke/death rate was 9.7%. The major disabling stroke/stroke-related death rate was 3.9%. 63 had a contralateral occlusion, 15 post-CEA, 17 post-radiation and 33 pre-coronary surgery. The major disabling stroke/stroke-related death rates for each subset were 4.8, 6.7, 0 and 0%, respectively. CONCLUSIONS: These results suggest that this category of patients is at high-risk of stroke regardless of method of carotid intervention.

Adult↗
PubMed2003

Complications following carotid angioplasty and carotid stenting in patients with symptomatic carotid artery disease.

BACKGROUND: We review a single centre's experience of the endovascular treatment of carotid artery disease, present the 30-day and 1-year complication rates and assess whether changes in technique are associated with a change in clinical outcome. METHODS: Patients who underwent carotid angioplasty with or without stenting for symptomatic > or = 70% carotid artery stenosis secondary to atherosclerosis were included. 333 procedures were performed, i.e. angioplasty alone (86), stent without cerebral protection (150) and stent with cerebral protection (97). RESULTS: At 30 days, the total major disabling stroke and all death rate was 3.0%. For angioplasty alone, this was 2.3%, for stent without cerebral protection 4.0% and for stent with cerebral protection 2.1%. If non-stroke-related deaths were excluded, it was 2.3, 3.3 and 0%, respectively. After 30 days, the 1-year ipsilateral stroke rate was 0.8%. CONCLUSIONS: Carotid artery stenting, in particular with a cerebral protection device, is a safe alternative to carotid endarterectomy for the treatment of symptomatic high-grade carotid artery disease.

Aged↗
PubMed2003

Being "at fault" in traffic crashes: does alcohol, cannabis, cocaine, or polydrug abuse make a difference?

OBJECTIVE: To compare associations of alcohol, cannabis, and cocaine abuse and traffic crash risk for "at fault" crashes and all crashes. DESIGN: A historical cohort study. SETTING: Toronto, Ontario. Patients or subjects: Subjects beginning treatment at the Centre for Addictions and Mental Health (CAMH) in 1994 for abuse of alcohol, cannabis, cocaine, and all combinations of these substances (n = 590, with 411 drivers). A control group consisted of 518 records from the Ontario registry of registered drivers, frequency matched for age and sex and residence. INTERVENTIONS: CAMH subjects took part in therapeutic programs. Pre-intervention (11 115 driver-years) and post-intervention intervals (8550 driver-years) were defined and compared. MAIN OUTCOME MEASURES: Crash and collision rates, adjusted relative risks (ARRs) of crash involvement and of "at fault" crashes were computed using Poisson regression to control for variations in time at risk, age, and sex of participants. RESULTS: Pre-treatment, significant ARRs of 1.49 to 1.79 for all crashes were found for abusers of cannabis, cocaine, or a combination. ARRs increased by 10%-15% for "at fault" crashes. Post-treatment, all associations were very modest for all abuse types. Only younger and male drivers had a significantly increased risk, which was stronger for "at fault" than for all crashes. CONCLUSIONS: Abuse of cannabis and cocaine pre-treatment was more strongly related to "at fault" crashes than to all crashes. Interaction between these substances means that the effects of combined abuse cannot be predicted from simple main effects.

Accidents, Traffic↗
PubMed2003

Nithsdale Schizophrenia Surveys 24: sexual dysfunction. Case-control study.

BACKGROUND: That sexual dysfunction occurs in schizophrenia is not in doubt. Previous studies have had weaknesses such as the use of selected populations or the absence of a control group. AIMS: To measure rates of sexual dysfunction in people with schizophrenia compared with the general population. METHOD: Sexual dysfunction was assessed by a self-completed gender-specific questionnaire. Ninety-eight (73%) of 135 persons with schizophrenia and 81 (71%) of 114 persons recruited as controls returned the questionnaire. RESULTS: At least one sexual dysfunction was reported by 82% of men and 96% of women with schizophrenia. Male patients reported less desire for sex, were less likely to achieve and maintain an erection, were more likely to ejaculate more quickly and were less satisfied with the intensity of their orgasms. Female patients reported less enjoyment than the control group. Sexual dysfunction in female patients was associated with negative schizophrenic symptoms and general psychopathology. There was no association between sexual dysfunction and type of antipsychotic medication. CONCLUSIONS: People with schizophrenia report much higher rates of sexual dysfunction than do the general population. Men and women with schizophrenia have a different pattern of sexual dysfunction.

Adult↗
PubMed2002

Residential care in the community for adults with intellectual disability: needs, characteristics and services.

BACKGROUND: The pattern of residential services for people with intellectual disability in England has changed dramatically since 1971, with many more places being made available in residential homes in the community. The aim of the present study was to assess the needs and characteristics of residents and features of all the residential homes provided by a national charity. METHOD: Assessments of adaptive behaviour, problem behaviour and social impairment were completed by staff who knew residents well; information about costs and staffing was provided from central records. RESULTS: A significant proportion of residents have important care needs relating to their skills, their behaviour and their social abilities. Residents with these needs are dispersed throughout services, so that a large majority of services include one or more residents with relatively complex needs. CONCLUSIONS: Compared with services in the late 1980s, these services care for a much more disabled client group. Since individuals with high levels of particular needs are typically distributed throughout services, a very high proportion of services require staff who have relatively advanced skills. Current national plans do not adequately address this need and case management arrangements may encourage the re-creation of more institutional services. DECLARATION OF INTEREST: The first author is a Trustee of the charity.

Activities of Daily Living↗
PubMed2002

The costs of trauma caused by seizures: can they be reduced?

This study surveyed admissions of patients with trauma caused by seizures from a population of over 400 000 to a Regional Neurosurgery, Plastic Surgery, Orthopaedic Surgical Services and a short-stay ward. Information on duration of epilepsy, seizure type, antiepileptic drugs (AEDs) and the co-existence of other neurological or psychiatric factors was reviewed and the hospital costs calculated. Twelve patients (eight males, four females, aged 28 to 78 years) had 13 admissions with 14 injuries caused by seizures during the period August 1995 to November 1998 (1% of the total admissions with the diagnosis of epilepsy). Seven had head-injuries, four had limb fractures or dislocations, two had burns and one had severe lacerations. The average duration of stays were between 1 day (short-stay ward) and 9-24 days for the three major services. The direct healthcare costs of this small group were high ( Ł 49 421) or Ł 3802 per traumatic incident. Clinical review suggested that the trauma could have been prevented by alternative care in seven patients at the most optimistic. Epilepsy is uncommon as a cause of severe trauma, the seizures may be difficult to prevent and the direct healthcare costs are high.

Craniocerebral Trauma↗
PubMed2001

The effects of introducing or lowering legal per se blood alcohol limits for driving: an international review.

In this review evidence on the impact of introducing or lowering legal blood alcohol limits on traffic safety measures is examined. There is substantial variability in the types and rigour of methods used to evaluate these legislative measures, and thus not surprisingly there is variability in the results observed. In most but not all cases where an evaluation of an introduced or lowered legal limit has been conducted, some beneficial effect on traffic safety measures has been reported. These effects are in some cases relatively small, and in other cases may be temporary. In some jurisdictions, lasting reductions in collision rates have been reported. Available evidence suggests that where beneficial effects are observed they are due to general deterrence, and not restricted only to drivers at blood alcohol concentrations (BAC) specifically affected by the legal change.

Accidents, Traffic↗
PubMed2001

Embolisation of renal arteriovenous malformation (AVM) in pregnancy.

A case of congenital renal arteriovenous malformation (AVM), presenting with profuse haematuria in the second trimester of pregnancy is reported. Selective embolisation with polyvinyl alcohol particles and absolute alcohol successfully ablated the lesion and a healthy infant was delivered at term five months later. Renal angiography at three years showed no evidence of the lesion.

Adult↗
PubMed2001

Common iliac artery access during endovascular thoracic aortic repair facilitated by a transabdominal wall tunnel.

PURPOSE: To describe a technique for common iliac artery (CIA) access during endovascular aortic aneurysm repair when unfavorable angulation between the CIA and the delivery sheath precludes direct arterial access. TECHNIQUE: After retroperitoneal exposure of the CIA, a puncture site is chosen inferolateral to the surgical incision, and an 18-G trocar/cannula is advanced in alignment with the CIA through the anterior abdominal wall or skin of the upper thigh into the retroperitoneal space. Serial dilatation is performed over a guidewire placed through the cannula to create the subcutaneous tract. The trocar/cannula is replaced over the wire, and the CIA is punctured under direct vision. The guidewire is then advanced into the proximal aorta. A CIA arteriotomy is performed and the delivery system introduced over the guidewire through the tunnel into the iliac artery. CONCLUSIONS: Retroperitoneal exposure of the CIA with tunneled transabdominal wall delivery of the stent-graft avoids both external iliac artery injury and creation of a temporary access conduit in patients with iliac tortuosity and/or occlusive disease.

Abdominal Muscles↗
PubMed2000

Pre-core mutant infections in the Canadian Inuit.

BACKGROUND/AIMS: Previous cross-sectional data suggested that chronic hepatitis B viral (HBV) infections in the Canadian Inuit were inactive. The aim of this study was to confirm these findings and document the prevalence of the subsequently described "pre-core mutant" variant of HBV in this population. METHODS: We obtained sera from residents of five remote Canadian Inuit communities. Residents were selected if they were known to be hepatitis B surface antigen (HBsAg) positive or had a history of liver disease. HBV serology, HBV-DNA, and pre-core mutant testing were performed by commercially available assays, polymerase chain reaction (PCR) and direct sequencing of the viral genome, respectively. RESULTS: Sera were obtained from 176/266 (66%) of selected individuals. Thirty-eight (22%) were HBsAg positive and 16 (9.1%) anti-HBs positive. Of HBsAg positive carriers 25/38 (66%) were male as compared to 68/138 (49%) of the remaining individuals (p<0.05). Of 37 HBsAg positive carriers, none were HBeAg positive, 36 (97%) anti-HBe positive and one (3%) HBeAg and anti-HBe negative. Liver enzyme and function tests were normal in all cases. 30/37 (81%) HBsAg positive carriers were HBV-DNA positive and 26/30 (87%) were pre-core mutant positive. CONCLUSION: The majority of HBV infections in community-based Canadian Inuit are inactive and the prevalence of pre-core mutant infections is the highest reported to date.

Adult↗
PubMed2000

Comparison of technical success and outcome of tunneled catheters inserted via the jugular and subclavian approaches.

PURPOSE: To compare the technical success and immediate and long-term outcomes of tunneled central venous catheters placed in comparative cohorts via the subclavian vein (SCV) and the internal jugular vein (IJV) routes. MATERIALS AND METHODS: This was a prospective observational single-center study of consecutive procedures. Between November 1993 and June 1995, 99 catheters were placed via the SCV and between December 1997 and July 1998, 109 catheters were placed via the IJV. Procedural data were recorded in both cohorts by completion of a proforma by the primary operator. RESULTS: Follow-up data were available in 96% of the SCV and 87% of the IJV cohorts. The average procedure time was significantly shorter in the IJV group and technical success was 100% versus 97% in the SCV group, but this did not reach statistical significance. The procedure-related pneumothorax rate and the rate of symptomatic venous thrombosis were significantly lower in the IJV cohort (P = .023, P = .015). Fewer catheters were removed prematurely due to sepsis in the IJV group (P = .043). CONCLUSIONS: The IJV route is associated with comparable technical success, and lower major procedural complication and venous thrombosis rates, with fewer catheters removed prematurely. The right IJV approach with ultrasound guidance is recommended as the route of choice for the placement of tunneled central venous catheters.

Catheterization, Central Venous↗