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Biomedical subjects

R Mackenzie

Publications and source records attributed to R Mackenzie.

At least 37 records · Page 2Linked to original sources

Pre-hospital anaesthesia.

Effective management of the airway may have the greatest impact on mortality and morbidity of all pre-hospital interventions. The administration of a pre-hospital anaesthetic may not only facilitate effective management and protection of the airway but may also be fundamental to maintaining adequate ventilation and reducing times to definitive treatment for casualties who are trapped and those with major chest and head injuries. Pre-hospital anaesthesia is a highly skilled technique that requires considerable training and experience. Inappropriate attempts to anaesthetise critically injured casualties may prove fatal if the operator does not have the requisite knowledge, skills and equipment. For those that do, this article provides an operational framework within which pre-hospital anaesthesia can be developed (Box 5).

Anesthesia, General↗

Community care. In the know.

People living in residential homes are becoming increasingly dependent and this trend is likely to continue, with more demands on district nursing services. An audit by one trust found that many staff in residential homes cared for highly dependent patients despite having little or no training. Primary care trusts are responsible for care in residential homes and should arrange staff training in preventing pressure injuries, managing incontinence, nutrition, rehabilitation, post-surgical care, and other topics.

Aged↗

Equipment for immediate medical care.

The equipment lists provided in this article are not intended to be proscriptive or definitive. They are simply an illustration of the logical application of equipment selection and packing principles according to the likely needs of the casualty. Although trained personnel with relatively little equipment can perform simple interventions, optimal care requires some advanced techniques and good quality comprehensive equipment. Such equipment is available for pre-hospital use. Regardless of what equipment is packed, the immediate care practitioner must understand the circumstances in which the equipment is likely to be used and tailor it to the likely needs of the casualty.

Choice Behavior↗

Conformational epitope of the type III group B Streptococcus capsular polysaccharide.

The protective epitope of the type III group B streptococcal polysaccharide (GBSPIII) is length dependent and conformational. To obtain a more accurate characterization of the conformational epitope, ELISA inhibition and surface plasmon resonance studies were conducted on two GBSPIII-specific mAbs using a large panel of oligosaccharide probes. The results of the studies confirmed that 2 repeating units (RU) is the minimum binding unit and that, while increases in chain length from 2 RU to 7 RU caused further optimization of the epitope, it remained monovalent. A 3-fold increase in affinity was observed between 7 RU and 20 RU, which, by surface plasmon resonance studies on a Fab, was shown to be due to both further optimization of the individual epitope and the occurrence of multivalency of epitope. The data support our hypothesis that the conformational epitope is an extended helical segment of the GBSPIII. GBSPIII exists mainly in the random coil form, which structurally mimics short oligosaccharide self Ags, but it can infrequently and spontaneously form extended helices. Although not prevalent in GBSPIII, the immune system preferentially selects these helical epitopes because they are unique to the polysaccharide. Contrary to a previously proposed model of GBSPIII binding in which the binding of the first Ab propagates a continuum of helical epitopes, our binding kinetics are consistent only with the helical epitope's being discontinuous and infrequent.

Animals↗

Scoring oral mucositis.

Oral mucositis is a common, dose limiting and potentially serious complication of both radiation and chemotherapy. Both these therapies are non-specific, interfering with the cellular homeostasis of both malignant and normal host cells. An important effect is the loss of the rapidly proliferating epithelial cells in the oral cavity, gut and in the bone marrow. Within the mouth, the loss of these cells leads to mucosal atrophy, necrosis and ulceration. Although post-treatment healing is generally uneventful, severe mucositis can be life threatening, especially if complicated by dehydration or secondary infection. Accurate and reproducible evaluation of oral mucositis is important in order to monitor patient toxicity during therapy, to document the toxicity of conventional therapy and to critically assess the effects of alternative therapies. A number of oral toxicity scoring systems have been described, but direct comparisons have rarely been undertaken and little data exist regarding inter- and intra-user reliability. This paper reviews a number of oral mucositis scoring systems that are commonly used and will also discuss, briefly, the biological basis of its development and management.

Antineoplastic Agents↗

Double-blind, placebo-controlled, crossover study of lamotrigine in treatment-resistant generalised epilepsy.

PURPOSE: Lamotrigine (LTG) is recognised as effective add-on therapy for focal epilepsies, but this is the first double-blind, placebo-controlled, crossover study in treatment-resistant generalised epilepsy. METHODS: The study consisted of 2 x 8-week treatment periods followed by a 4-week washout period. Patients received doses of either 75 or 150 mg daily, depending on their concomitant antiepileptic drugs (AEDs). Long-term continuation was offered at the end of the study with open-label LTG. RESULTS: Five centres in Australia recruited 26 patients who were having absence, myoclonic, or generalized tonic-clonic seizures or a combination of these. Twenty-two patients completed the study. There was a significant reduction in frequency of both tonic-clonic and absence seizure types with LTG. A 350% decrease in seizures was observed for tonic-clonic seizures in 50% of cases and for absence seizures in 33% of evaluable cases. Rash was the only adverse effect causing discontinuation. Twenty-three of 26 opted for open-label LTG, with 20 still receiving LTG for a mean of 26 months. In these 20, 80% had > or =50% seizure reduction and five (25%) were seizure free. CONCLUSIONS: This study shows that LTG is effective add-on therapy in patients with refractory generalised epilepsies. Statistically significant reduction in seizures in both absence and tonic-clonic seizure types was seen even with low doses of LTG.

Adolescent↗

Magnetic resonance imaging of the shoulder: assessment of effectiveness.

OBJECTIVES: To quantify how magnetic resonance imaging (MRI) influences clinicians' diagnosis, diagnostic confidence and management plans in patients with shoulder problems. To investigate whether such changes are associated with an improvement in health. METHODS: A prospective observational study on all patients referred to a regional centre for MRI of the shoulder over a 6-month period. Data on diagnosis, diagnostic confidence and proposed management before MRI were compared with diagnoses and actual management after MRI. In addition, short form 36 item (SF-36) health survey data were collected at referral and again 6 months later. RESULTS: In 86 of 99 MRI referrals there was sufficient clinical data for the patient to enter the study. MRI led to previously unsuspected diagnoses in 20 of 59 patients where the clinicians had provided full diagnostic information before and after the examination. When MRI confirmed the clinical diagnosis, significant improvements in clinicians' diagnostic confidence were found (P < 0.001). MRI led to a change in management (P < 0.05) in 44 (62%) of the 71 patients where full management plans were available. Health survey results were available in 62 patients; although there were some improvements in SF-36 scores, these did not reach statistical significance. CONCLUSION: Magnetic resonance imaging of the shoulder significantly influences clinicians' diagnoses and management plans. However, patients do not record a statistically significant improvement in health-related quality of life over 6 months.

Adolescent↗

Magnetic resonance imaging of the knee: assessment of effectiveness.

OBJECTIVES: To quantify how magnetic resonance imaging (MRI) influences clinicians' diagnoses, diagnostic confidence and management plans in patients with knee problems. To investigate whether these changes can bring about an improvement in health. METHODS: This was a prospective observational study on all patients referred to a regional unit for MRI of the knee over a 6-month-period. Data on diagnosis, diagnostic confidence and proposed management before MRI was compared with diagnoses and actual management after MRI. In addition, short form 36 item (SF-36) health survey data was collected at referral and again 6 months later. RESULTS: Three hundred and thirty-two patients were entered into the study. MRI led to previously unsuspected diagnosis in 69 of 269 patients with available data. When MRI confirmed the clinical diagnosis, significant improvements in clinicians' diagnostic confidence were found (P < 0.01 for medical meniscus, P < 0.05 lateral meniscus, P < 0.05 anterior cruciate). MRI led to a change in management in 180 (63%) of 288 patients (where data available). There was a significant shift away from surgical management after MRI (P < 0.01). SF-36 results were available in 206 patients. There was a significant improvement over time in five of the eight SF-36 scales (four at P < 0.001, one at P < 0.01). CONCLUSIONS: Magnetic resonance imaging significantly influences clinicians' diagnoses and management plans. These patients, examined by MRI, also recorded an improvement in health related quality of life.

Adolescent↗

Magnetic resonance imaging of the knee: diagnostic performance studies.

OBJECTIVES: To review and reassess the published diagnostic performance statistics for MRI of the menisci and cruciate ligaments. To illustrate the potential sources and effects of bias in the evaluation of this widely accepted diagnostic technique. METHODS: Published evaluations of knee MRI were identified from the literature. Criteria for inclusion in the review were a total sample size > or = 35, arthroscopic correlation of MRI findings and presentation of complete results. Diagnostic performance statistics were then recalculated for each published study. RESULTS: Twenty-two studies were identified with sample sizes between 35 and 1014. The overall sensitivity for MRI of the menisci and cruciates was 0.88 (95% confidence interval 0.86-0.90). The overall specificity was 0.94 (0.93-0.94). Sampling error varied widely amongst studies and was rarely quantified. CONCLUSIONS: Diagnostic performance statistics are widely used. It is still not well appreciated that these are subject to sampling error. Such errors make meaningful comparisons between published studies more difficult. Nevertheless, the results for meniscal and cruciate lesions are consistently high and support the use of MRI for these common problems. The diagnostic performance of other applications of MRI should be subjected to similar critical review.

Anterior Cruciate Ligament↗

A double-blind, placebo-controlled crossover study of vigabatrin 2 g/day and 3 g/day in uncontrolled partial seizures.

The efficacy and tolerability of vigabatrin as add-on therapy was assessed in patients with uncontrolled partial seizures. Ninety-seven patients entered this seven-centre, double-blind, placebo-crossover study. Vigabatrin (2 g or 3 g) or placebo was administered daily. Vigabatrin was well-tolerated and did not cause clinically significant adverse drug effects when added to established anticonvulsant therapy. No significant differences were observed between dose groups for the overall incidence of adverse events, although drowsiness and visual disturbances (diplopia, ataxia, visual abnormalities) showed a dose-related increase with vigabatrin treatment. The results of this study indicate that vigabatrin, given in a daily dose of either 2 g or 3 g is significantly more effective than placebo in reducing seizure frequency among patients with partial seizures.

Adolescent↗