Biomedical subjects
Publications and source records attributed to C Robertson.
It is essential that health professionals feel comfortable in a working environment which enables them to work effectively and efficiently. This study used an ergonomic approach to analyse whether the layout of equipment and materials in a trauma resuscitation unit met its users' needs.
The pattern, severity and circumstances of injury sustained by 52 motorcyclists admitted as the result of a road traffic accident were prospectively documented. Forty-eight of the patients were drivers and four were pillion passengers. Three of the drivers and all of the pillion passengers were female. Injuries to motorcyclists accounted for 0.4% of the total workload of the department during the course of the study, and for 14% of all injuries seen there arising from road traffic accidents. Eighty-nine per cent of the patients were aged less than 25 years and the oldest patient was aged 44 years. Patients under the age of 21 years were injured more severely than those aged 21 years or more. The majority of injuries (67%) involved the limbs with the right arm and leg being injured twice as often as the left arm and leg. Arms and legs were injured with equal frequency. Head and facial injuries comprised only 9% of the total. Two patients were observed not to be wearing helmets at the time of the accident. Patients admitted between midnight and 05.59 hours sustained injuries of greater severity than those admitted between 06.00 and 23.59. Fifty per cent of patients had an Injury Severity Score of less than five, and only four patients had Injury Severity Score of 25 or more. One third of patients were riding motorcycles with an engine size of 750cc or greater. This group of patients was younger than patients riding less powerful motorcycles and also sustained injuries of greater severity.
The dense tubular system (DTS) functions to regulate platelet activation by sequestering or releasing calcium, similar to the sarcotubules of skeletal muscle. In resting platelets, the DTS exists as thin elongated membranes. Within 10 seconds of the addition of thrombin, platelets show a major ultrastructural change in their DTS: from the thin elongated form to a rounded vesicular form. These morphologic changes were demonstrated with two different stains and two different fixation methods. Platelets exposed to the calcium ionophore A23187 showed the same ultrastructural changes in the DTS. In contrast, the DTS remains in a thin elongated form when platelets are stimulated by the protein kinase C activators phorbol 12-myristate 13-acetate (PMA) and oleoylacetylglycerol (OAG). These morphologic changes may be related to the discharge of calcium from the DTS because this is stimulated by thrombin and A23187, but not by PMA. Preincubation of the platelets with the intracellular calcium chelator 5,5'-dimethyl-bis-(0-aminophenoxy)-ethane-N,N,N',N tetra acetic acid (BAPTA) largely prevented both the thrombin-induced rise in intracellular calcium and the changes in DTS morphology, suggesting that the changes in DTS morphology are secondary to the increase in cytosolic calcium. The results provide a morphologic correlate to existing biochemical evidence showing that the DTS is involved early during paltelet activation.
BACKGROUND: This study evaluated the effect of endoscopic treatment for malignant dysphagia on quality of life (QL) as part of a prospective comparison of Nd:YAG laser therapy and intubation. METHODS: Two QL instruments were used: the Quality of Life Index (QLI) and a Linear Analogue Self-Assessment (LASA). Only 23 of 43 patients receiving laser therapy and 15 of 30 having endoscopic intubation agreed to partake in QL assessment; serial measurements until death were obtained in 13 and 9 patients, respectively. RESULTS: Dysphagia grade (DG) as measured on a 5-point scale, correlated significantly with LASA (n = 92; r = -0.51; P less than 0.0001) and QLI (n = 92; r = -0.43; P less than 0.0001) scores. In addition, there was a strong correlation between LASA and QLI scores (r = 0.678; P less than 0.0001). All patients followed up serially until death derived significant palliation of their dysphagia with laser treatment and intubation. Such therapy resulted in a significant initial improvement in QL, with the mean best LASA and QLI scores after treatment being higher than the corresponding mean pretreatment scores (P less than 0.004). However, this improvement proved transient; QL worsened significantly as a patient's general condition deteriorated during the final stages of the illness. The mean last post-treatment LASA and QLI scores in both groups (recorded within 5 weeks of death) were less than the corresponding mean pretreatment scores (P less than 0.004). CONCLUSIONS: Endoscopic palliation of malignant dysphagia results in a significant initial improvement in QL. Subsequently, QL worsens appreciably as a patient's general condition deteriorates during the terminal phase of disease.
The immunological crossreactivity between the two granule-specific membrane glycoproteins, synaptophysin and granulophysin, was studied using a series of site-specific monoclonal and polyclonal antibodies. The epitope relatedness of six monoclonal antibodies against granulophysin was examined by competitive ELISA. The antibodies are shown to recognize distinct, but overlapping epitopes within a compact region that is constructed by the three-dimensional configuration of the molecule. All these antibody clones also recognize rat neuronal synaptophysin. Two monoclonal antibodies against synaptophysin, of which one is the well-characterized SY38 antibody, directed against the carboxy terminal of the molecule, are also shown to react with granulophysin. Characterized polyclonal antibodies against different peptide antigens of synaptophysin failed to recognize granulophysin. Synaptophysin and granulophysin are distinctly recognized in brain cell (white matter) and the pituitary both qualitatively and quantitatively. Based on these and other observations, it is suggested that the repeat motif in the cytoplasmic tail of synaptophysin represents an immunodominant construct that is the target for the observed crossreactive antibodies and that a similar tertiary construct has been preserved in granulophysin and in other transmembrane proteins.
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OBJECTIVE: To assess whether the management of asthma has improved from three consecutive surveys. DESIGN: Retrospective case note survey of acute asthma admissions in 1983 and 1989; case notes selected from 1985-6 survey of prospectively identified patients to include only patients with a final discharge code of asthma. SETTING: A large city teaching hospital. Patients--101 patients with acute asthma as the primary diagnosis in 1983; 85 in 1985-6; and 133 in 1989, 14 of whom were subsequently transferred elsewhere. MAIN MEASURES: Conformity with a checklist of important aspects of the process of asthma management including initial assessment, treatment, supervision, and discharge and review arrangements. RESULTS: All patient groups were similar in age, smoking habit, and stay in hospital and, as an objective guide to severity of asthma, had similar initial pulse rates. Major improvements occurred in management: by 1989, 119(90%) patients were treated with oral corticosteroids (69(68%), 67(79%) in 1983, 1985-6 respectively) and 109(82%) with oxygen (62(61%), 51(60%)) (both p < 0.001). 114(86%) had regular recording of peak flow measurements (53(52%), 54(64%); p < 0.001), and 103/119(86%) were discharged taking oral corticosteroids (66(65%), 63(74%); p < 0.01). Significantly fewer patients, however, had their regular inhaled corticosteroid treatment increased on discharge (38/119(32%) v 53(52%), 39(46%); p < 0.01), but more were receiving high dose inhaled treatment on admission. CONCLUSIONS: The management of asthma improved significantly, and the normal practice of doctors has changed in an area of practice with longstanding problems.
BACKGROUND AND PURPOSE: Conventional diets may cause hyperglycemia in patients with neurological injuries. The purpose of this study was to examine the effect on the severity of cerebral infarction of replacing carbohydrates as the primary dietary source of nonprotein calories. METHODS: Sixty-nine Long-Evans rats were either fasted for 24 hours, fed isocaloric amounts of a control diet containing 51.5% of the calories as carbohydrates, or fed one of five experimental diets before middle cerebral artery occlusion for 45 minutes. In the experimental diets, 60% of the carbohydrate calories were replaced with one or more of the following substrates: 1,3-butanediol, triacetin, tributyrin, and long- and medium-chain triglycerides. RESULTS: The plasma glucose concentration in the fasted animals was 6.4 +/- 1.1 mumol/ml. In the animals receiving the control diet, which contained the greatest number of carbohydrate calories, plasma glucose was 9.1 +/- 1.4 mumol/ml. The 1,3-butanediol diet resulted in an intermediate plasma glucose concentration averaging 7.8 +/- 1.3 mumol/ml. Plasma beta-hydroxybutyrate levels were elevated in the fasted group and with the 1,3-butanediol diet. Plasma acetate levels were increased with the diets supplemented with triacetin. The smallest infarct volume (53 +/- 43 mm3) was found in the fasted group and the largest (162 +/- 56 mm3) in the control diet group. Infarct volumes that were significantly smaller were found with the 1,3-butanediol diet (98 +/- 41 mm3) and with the triacetin/tributyrin diet (105 +/- 53 mm3). The volume of the infarct was directly related to the plasma glucose concentration before ischemia (n = 69, r = 0.47, p less than 0.01), but not to plasma lactate, ketone body, or acetate levels. CONCLUSIONS: It may be possible to develop a diet for patients with neurological injuries using noncarbohydrate calorie sources, such as 1,3-butanediol, triacetin, or tributyrin, that would supply systemic caloric and protein requirements without the adverse effect of conventional diets.
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Ergonomics is the practical and scientific study of people in relation to their working environment. We describe its application to the operation of a trauma resuscitation room. We used specifically designed computer software. This methodology enables a unique and objective assessment of the design and operation of a clinical system. It may be particularly applicable to other hospital areas where the efficient interaction of staff, patients and equipment is crucial to the optimal clinical outcome.
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The fecal osmotic gap is considered to be useful in the investigation of chronic diarrhea. However, two important questions regarding the calculation of the osmotic gap remain unanswered: the effect of the method of measuring osmolality and the most appropriate means for its calculation. In 41 patients with varying causes of diarrhea, stool osmolalities and electrolyte concentrations were measured. Measurement of stool osmolality by a dew point technique underestimated results by a variable factor, which makes it an inappropriate method. Fecal osmolality measured by freezing point depression gave reliable results and so was considered to be preferable. The osmotic gap was calculated by two methods: subtraction of the calculated osmolality from (1) stool osmolality and (2) plasma osmolality. The former approach was found to be inappropriate on the basis of large variations in results when consecutive stool samples were analyzed, a poor correlation with the severity of osmotic diarrhea, poor resolution between results from patients with secretory diarrhea and those with osmotic diarrhea, and practical difficulties in ensuring adequate collection of stool samples.
The effect of lipid lowering on hard exudates was determined in six consecutive patients with insulin-dependent diabetes mellitus. Diet and hypolipidemic drug therapy including the use of pravastatin, a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme-A reductase, were used to treat patients for one year. The total cholesterol concentration decreased from a mean baseline value of 231 mg/dl to a treatment mean value of 165 mg/dl. The mean low-density lipoprotein cholesterol concentration decreased from 157 mg/dl to 93 mg/dl. Masked grading of fundus photographs indicated an improvement in hard exudates in all six patients and a decrease in microaneurysms in four patients. Visual acuity improved in one patient and did not change (one line or less change) in five patients. No remarkable side effects resulting from treatment were observed. Our pilot study suggests that aggressive therapy of diabetic patients with hyperlipidemia may have a beneficial effect on background retinopathy.
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