PubMed Health⌕ Search

Biomedical subjects

I McDonald

Publications and source records attributed to I McDonald.

At least 19 recordsLinked to original sources
PubMed2003

Evaluating podiatry services: testing a treatment specific measure of health status.

This study reports on the preliminary testing of a new measure designed for use alongside EQ-5D in evaluating outcomes in podiatry: the Podiatry Health Questionnaire (PHQ). Individuals aged 18 years or more, receiving podiatry services in clinic or domicilliary locations across four NHS Trusts in Yorkshire and Humberside UK took part in a questionnaire survey. Respondents reported high levels of problems on all six PHQ dimensions. Correlations suggested that the PHQ and EQ-5D were measuring distinct constructs. The levels on each dimension were well defined in terms of self-rated morbidity on the PHQ visual analogue scale (PHQvas) and the EQ-5Dvas, although PHQvas appeared to be slightly more sensitive to changes in health on the dimensions. There was a strong relationship between clinicians' Podiatry Clinical Score rating and reported symptoms for four out of six PHQ dimensions and PHQvas. The PHQ was able to distinguish respondents in terms of their self-reported morbidity in EQ-5D and in terms of their morbidity as assessed by clinicians. It is suggested that the respondent completed PHQ appears to be a useful new measure for assessing foot-related health. However, further investigation of the psychometric properties of the measure is required.

Adolescent↗
PubMed2001

Effect of L-carnitine treatment for valproate-induced hepatotoxicity.

The authors analyzed the association of L-carnitine treatment with hepatic survival in 92 patients with severe, symptomatic, valproate-induced hepatotoxicity. Forty-eight percent of the 42 patients treated with L-carnitine survived, but only 10% of the 50 patients treated solely with aggressive supportive care survived (p < 0.001). Early intervention with IV rather than enteral L-carnitine was associated with the greatest hepatic survival. Specifically, all 10 patients who were diagnosed in <5 days and treated with IV L-carnitine survived. Most patients had features of chronic illness and most children appeared to be malnourished.

Adolescent↗
PubMed2001

Taxonomic characterization of new alkaliphilic and alkalitolerant methanotrophs from soda lakes of the Southeastern Transbaikal region and description of Methylomicrobium buryatense sp.nov.

Five strains of obligate methanotrophic bacteria (4G, 5G, 6G, 7G and 5B) isolated from bottom sediments of Southeastern Transbaikal soda lakes (pH 9.5-10.5) are taxonomically described. These bacteria are aerobic, Gram-negative monotrichous rods having tightly packed cup-shaped structures on the outer cell wall surface (S-layers) and Type I intracytoplasmic membranes. All the isolates possess particulate methane monooxygenase (pMMO) and one strain (5G) also contains soluble methane monooxygenase (sMMO). They assimilate methane and methanol via the ribulose monophosphate pathway (RuMP). The isolates are alkalitolerant or facultatively alkaliphilic, able to grow at pH 10.5-11.0 and optimally at pH 8.5-9.5. These organisms are obligately dependent on the presence of sodium ions in the growth medium and tolerate up to 0.9-1.4 M NaCl or 1 M NaHCO3. Although being mesophilic, all the isolates are resistant to heating (80 degrees C, 20 min), freezing and drying. Their cellular fatty acids profiles primarily consist of C(16:1). The major phospholipids are phosphatidylethanolamine and phosphatidylglycerol. The main quinone is Q-8. The DNA G+C content ranges from 49.2-51.5 mol %. Comparative 16S rDNA sequencing showed that the newly isolated methanotrophs are related to membres of the Methylomicrobium genus. However, they differ from the known members of this genus by DNA-DNA relatedness. Based on pheno- and genotypic characteristics, we propose a new species of the genus Methylomicrobium Methylomicrobium buryatense sp. nov.

DNA, Ribosomal↗
PubMed1999

Molecular analysis of a novel methanesulfonic acid monooxygenase from the methylotroph Methylosulfonomonas methylovora.

Methylosulfonomonas methylovora M2 is an unusual gram-negative methylotrophic bacterium that can grow on methanesulfonic acid (MSA) as the sole source of carbon and energy. Oxidation of MSA by this bacterium is carried out by a multicomponent MSA monooxygenase (MSAMO). Cloning and sequencing of a 7.5-kbp SphI fragment of chromosomal DNA revealed four tightly linked genes encoding this novel monooxygenase. Analysis of the deduced MSAMO polypeptide sequences indicated that the enzyme contains a two-component hydroxylase of the mononuclear-iron-center type. The large subunit of the hydroxylase, MsmA (48 kDa), contains a typical Rieske-type [2Fe-2S] center with an unusual iron-binding motif and, together with the small subunit of the hydroxylase, MsmB (20 kDa), showed a high degree of identity with a number of dioxygenase enzymes. However, the other components of the MSAMO, MsmC, the ferredoxin component, and MsmD, the reductase, more closely resemble those found in other classes of oxygenases. MsmC has a high degree of identity to ferredoxins from toluene and methane monooxygenases, which are enzymes characterized by possessing hydroxylases containing mu-oxo bridge binuclear iron centers. MsmD is a reductase of 38 kDa with a typical chloroplast-like [2Fe-2S] center and conserved flavin adenine dinucleotide- and NAD-binding motifs and is similar to a number of mono- and dioxygenase reductase components. Preliminary analysis of the genes encoding MSAMO from a marine MSA-degrading bacterium, Marinosulfonomonas methylotropha, revealed the presence of msm genes highly related to those found in Methylosulfonomonas, suggesting that MSAMO is a novel type of oxygenase that may be conserved in all MSA-utilizing bacteria.

Amino Acid Sequence↗
PubMed1997

Cardiac disease construction on the borderland.

The diagnosis of possible heart disease in the well patient has undergone remarkable shifts over the past century. The traditional medical view places strong emphasis on the contribution of technological data to the diagnosis of disease. In the case of serious heart disease, cardiac diagnostic technologies can play a defining role but, more often in the clinical context, patients are assessed for heart disease which is minor. The question is whether disease is present at all. In this borderland between health and disease, the interpretation of technological data is inherently uncertain. The diagnosis then depends more heavily on the social utility of particular disease categories. Shifts in diagnostic categorisation are not therefore attributable solely to more extensive forms of cardiac imaging but are socially constructed in an interactive context which involves the technology, the medical profession and the wider social structures which exist at the time of diagnosis. Claims of technological certainty create a social space within which the medical profession generates disease categories. These shifting disease categories may serve the needs of patients but may also be influenced by those of other players.

Cardiology↗
PubMed1997

Trends in in-hospital mortality following acute myocardial infarction (AMI) in Victoria, 1987-1994.

BACKGROUND: Death rates from coronary hearts disease have exhibited remarkable declines in most industrialised countries. Cardiovascular mortality has been the subject of extensive research and we considered it important to analyse recent local population based data on hospital outcomes of acute myocardial infarction (AMI). AIM: To document the trends in in-hospital mortality from AMI in Victoria from 1987-1994. METHODS: This was a retrospective analysis of data from the Victorian Inpatient Minimum Database relating to all public acute care hospitals. All separations recording a principal diagnosis 410 (AMI) were selected. Changes in distribution of AMI separations, in-hospital mortality, and changes in length of stay were examined. RESULTS: The mean age of women admitted was 72 years compared with 64 years for men. Women comprised around a third of the overall sample but the proportion varied from 13% in those under 50 years to 57% among those aged 80 years and over. A striking decline in mortality was observed throughout the eight year period. The relative age adjusted decline was 33.5% (40% in males and 26% in females) with rates remaining higher in women. This decline occurred despite the increasing representation of those aged over 80 years. There was a significant decline in the mean length of stay (1.8 days) over the eight year period but this is likely to have had only minimal impact on mortality rates. CONCLUSION: We have documented welcome declines in in-hospital mortality from AMI that are not an artefact of declining lengths of stay. Our observations parallel those in similar overseas studies. Large changes in medical management have taken place from the mid 1980s and may be partly responsible, but a change in disease process cannot be ruled out.

Aged↗
PubMed1996

The assessment of diagnostic imaging technologies: a policy perspective.

Diagnostic imaging technologies are essential in health care but have high costs and poorly defined benefits. Formulation and implementation of policy on their procurement and use is made difficult by the complexity of the diagnostic process, and the limitations of available data and assessment methodology. Informed policy decisions will need to be based on a synthesis of imperfect data from a variety of perspectives, and supplemented by effective dissemination and feedback of information. A list of attributes for consideration in the policy formulation process is presented.

Australia↗
PubMed1996

Mortality soon after discharge from a major teaching hospital: linking mortality and morbidity.

In this pilot study, data held by the Registrar of Births, Deaths and Marriages was linked to the Patient Master Index at St Vincent's Hospital Melbourne in order to identify early post discharge deaths, and inpatient records were linked with the Victorian Inpatient Minimum Database. Between July 1991 and December 1993 there were 831 deaths within 28 days of discharge. Injuries and poisoning were the commonest cause of death in younger patients who had attended the emergency department. These were responsible for 64% of deaths under the age of 40 years. There were deaths from cardiovascular disease which had been unrecognised during the hospital stay. There is also the need to identify in hospital those at risk of suicide. Amongst inpatients who were discharged home or transferred, the risk of death was greatest in the days immediately following discharge. Policies relating to the transfer of patients need to be reviewed as the study found that 30% of patients who had been transferred to long term care facilities died within four days. In conclusion, linking mortality and morbidity data can highlight areas of hospital care where there is the potential to prevent premature death, and improve management. The outcome of coronial investigations should be transmitted to hospitals for quality assurance purposes.

Adult↗
PubMed1996

Leaving hospital against medical advice.

Early post-discharge deaths were identified in a recent study based at St Vincent's Hospital, Melbourne, over a two and a half year period. As a result of linking patient records with the Victorian Minimum Database (VIMD) those who had discharged themselves against medical advice (ama) were identified. In this study information relating to all patients who discharged themselves ama from St Vincent's Hospital was obtained from the VIMD. We found that 1.5% of separations over the study period were discharges ama. Nearly half were over the age of 60 years. Injuries and poisoning, circulatory disorders and mental disorders were the most common diagnostic categories associated with discharge ama. The specific conditions contained within these included fractured neck of femur, cerebral occlusion and subarachnoid haemorhage. The study raises the important question of how discharge ama affects the clinical outcome in patients with such serious conditions. A follow up of such patients, which includes interviews with clinicians and families is suggested. The patients who died within 28 days were in the main elderly, suffering from malignancy. Even in these cases a knowledge of the attitudes and experiences of clinicians would be useful in order to manage optimally requests by critically ill patients for discharge.

Adult↗
PubMed1994

Prediction of delayed neurological deficit after subarachnoid haemorrhage: a CT blood load and Doppler velocity approach.

The predictive value of cranial computed tomography (CT) blood load and serial transcranial Doppler sonography for the development of delayed ischaemic neurological deficit was assessed in 121 patients following subarachnoid haemorrhage. Of the 121 patients, 81 (67%) had thick layers of blood or haematoma, including intraventricular bleeding. The proportion of patients who developed delayed deficit was higher with increasing amounts of subarachnoid blood on the admission CT (51% of 53 cases in Fisher grade 3; 35% of 33 cases in grade 2; 28% of 7 cases in grade 1, P < 0.01). Doppler velocities obtained from readings at least every 2 days following admission were higher in patients with delayed neurological deficit (peak velocity for grade 3 patients 176 +/- 6 cm/s (mean +/- SE), versus grade 2: 164 +/- 7 cm/s; grade 4 149 +/- 9, both P = 0.04, Mann-Whitney). Peak velocity and maximal 24-h rise tended to be higher within different CT grades in patients with a deficit than in those without; this difference was significant for grade 3 patients (P < 0.01). We conclude that a combined approach with CT and Doppler sonography provides greater predictive value for the development of delayed ischaemic neurological deficit than either test considered independently. The value of Doppler sonography may be greatest for patients with Fisher grade 3 blood, in whom the risk of delayed ischaemia is greatest.

Adult↗
PubMed1993

Angiographic and Doppler diagnosis of cerebral artery vasospasm following subarachnoid haemorrhage.

Angiographic middle and anterior cerebral artery diameter and transcranial ultrasound flow velocity measurements were performed within 24 h of each other in 102 patients with recent aneurysmal subarachnoid haemorrhage. There was a significant inverse correlation between middle cerebral artery diameter and flow velocity (r = -0.54, p < 0.001). No such correlation was seen for anterior cerebral arteries (r = -0.25). The ratio of middle cerebral artery to extracranial internal carotid artery velocities, which is an index of vasospasm, did not show improved correlation with arteriographic diameters, compared with uncorrected middle cerebral artery readings. Middle and anterior cerebral artery velocities and diameters both began to show significant changes indicative of vasospasm from day 4-5 onwards, suggesting that an increase in Doppler velocity is a good indicator of middle cerebral artery diameter, as shown by angiography. These studies indicate that transcranial Doppler is a useful non-invasive monitor for the development of delayed vasospasm following subarachnoid haemorrhage.

Adolescent↗
PubMed1993

Use of transcranial Doppler sonography to predict development of a delayed ischemic deficit after subarachnoid hemorrhage.

Blood flow velocity was recorded from the middle or anterior cerebral and extracranial internal carotid arteries using transcranial Doppler sonography (TCD) in 121 unselected consecutive patients with acute aneurysmal subarachnoid hemorrhage (SAH). Recordings were made daily or every 2nd day after SAH for a 14-day period. The highest recorded velocity was greater in the 47 patients who developed a delayed ischemic neurological deficit (186 +/- 6 cm sec-1; mean +/- standard error of the mean) than in the 74 patients who did not develop a neurological deficit (149 +/- 5 cm sec-1) (p < 0.001, Mann-Whitney test). Peak velocity recordings can thus assist in the diagnosis of delayed ischemic neurological deficit; however, peak velocity was often recorded only after the onset of neurological deficit. When only those readings made before the onset of neurological deficit were considered, there was no significant difference in peak velocity between the groups (157 +/- 8 cm sec-1 vs. 149 +/- 5 cm sec-1, respectively). Alternative TCD parameters for predicting delayed neurological deficit were therefore sought. The rate of increase in TCD velocity, recorded during the first few days after SAH, was significantly higher in the patients who later developed a neurological deficit. A maximum velocity increase of 65 +/- 5 cm sec-1 per 24-hour period was recorded in patients who later developed a neurological deficit, compared to 47 +/- 3 cm sec-1 24 hrs-1 in patients who did not develop a delayed neurological deficit (p = 0.003). A rise of more than 50 cm sec-1 24 hrs-1 identifies those patients who are most likely to develop a delayed ischemic neurological deficit after SAH. This can be applied prospectively to individual cases. Serial TCD studies in the early period after SAH are thus of value to identify patients who can be selected for prophylactic therapy, which may prevent or ameliorate development of delayed ischemic neurological deficits.

Adolescent↗
PubMed1992

A protective role for nitric oxide in the oxidative modification of low density lipoproteins by mouse macrophages.

Low density lipoproteins (LDL) oxidatively modified by macrophages have been shown to be atherogenic in ex vivo studies. We studied the potential role of nitric oxide (NO), a free radical produced by macrophages, in LDL modification. Human LDL (1 mg/ml) were incubated with mouse peritoneal macrophages in Ham's F-10 medium. The cells were then stimulated by interferon-gamma and tumor necrosis factor-alpha to increase their production of NO from 1.3 to 12.2 microM in 24 h, as measured by nitrite. Lipid peroxidation of LDL, as measured by thiobarbituric acid-reactive materials (TBARS), was reduced in stimulated cells in a time-dependent manner. At 24 h, the decrease was about 27%. In the presence of an NO synthase inhibitor (NG-aminophomoarginine), the generation of NO was diminished and the protection against LDL lipid peroxidation was reversed. The extent of LDL protein modification was also assessed by examining its electrophoretic mobility. It was found that macrophage NO reduced the change in LDL electromobility. These data indicate that the production of NO may inhibit the oxidative modification of LDL with cytokine-stimulated macrophages. We suggest that NO plays a protective role in limiting macrophage-induced LDL modification.

Animals↗