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Biomedical subjects

M K Benson

Publications and source records attributed to M K Benson.

At least 19 recordsLinked to original sources
PubMed1992

Effect of carbohydrate rich versus fat rich loads on gas exchange and walking performance in patients with chronic obstructive lung disease.

BACKGROUND: High calorie intakes, especially as carbohydrate, increase carbon dioxide production (VCO2) and may precipitate respiratory failure in patients with severe pulmonary disease. Energy obtained from fat results in less carbon dioxide and thus may permit a reduced level of alveolar ventilation for any given arterial blood carbon dioxide tension (PaCO2). METHODS: Ten patients with stable severe chronic obstructive lung disease underwent a six minute walk before and 45 minutes after taking 920 kcal of a fat rich drink, an isocalorific amount of a carbohydrate rich drink, and an equal volume of a non-calorific control liquid on three separate days, in a double blind randomised crossover study. Borg scores of the perceived effort to breathe were measured at the beginning and end of each six minute walk. Minute ventilation (VE2), VCO2, oxygen consumption (VO2), respiratory quotient (RQ), arterial blood gas tensions, and lung function were measured before and 30 minutes after each test drink. RESULTS: Baseline measurements were similar on all three test days and the non-calorific control drink resulted in no changes in any of the measured variables. The carbohydrate rich drink resulted in significantly greater increases in VE, VCO2, VO2, RQ, PaCO2, and Borg score and a greater fall in the distance walked in six minutes than the fat rich drink (mean fall after carbohydrate rich drink 17 m v 3 m after fat rich drink and the non-calorific control). The increase in VCO2 correlated significantly with the decrease in six minute walking distance and the increase in Borg score after the carbohydrate rich drink. The only significant change after the fat rich drink when compared with the non-calorific control was an increase in VCO2. CONCLUSIONS: Comparatively small changes in the carbohydrate and fat constitution of meals can have a significant effect on VCO2, exercise tolerance, and breathlessness in patients with chronic obstructive lung disease.

Aged↗
PubMed1992

Acute pneumonitis associated with low dose methotrexate treatment for rheumatoid arthritis: report of five cases and review of published reports.

BACKGROUND: Low dose methotrexate has become established in the treatment of refractory rheumatoid arthritis. Until recently it has been considered that the use of a low dose regimen (< 20 mg/week) would avoid the pulmonary toxicity associated with the higher doses prescribed in malignant disease. Although initial experience with low dose methotrexate was encouraging, an increasing number of cases of an acute, life threatening pneumonitis are being reported in patients with refractory rheumatoid arthritis. PATIENTS: Since 1984 43 patients with refractory rheumatoid arthritis have been established on low dose methotrexate in the Oxford Health District. Five of these patients have subsequently developed acute methotrexate induced pneumonitis. The clinical and radiological features of these cases are described and previous reports reviewed. RESULTS: Five patients having low dose methotrexate treatment developed acute pneumonitis. Presentation was subacute and dominated by constitutional features. Respiratory symptoms developed insidiously but progressed rapidly with increasing dyspnoea associated with severe hypoxia. Chest radiographs were non-specific, showing diffuse interstitial infiltration and alveolar shadowing. Microbiological investigation gave negative results. In all cases methotrexate was discontinued and high dose corticosteroids started, with rapid clinical and radiological improvement. After withdrawal of steroid both clinical and radiological resolution was maintained at follow up. CONCLUSION: Acute pneumonitis is an uncommon but serious adverse effect of low dose methotrexate treatment for refractory rheumatoid arthritis. The initial presentation is non-specific and a high index of suspicion is required as respiratory failure may develop rapidly. Management depends on exclusion of infection, withdrawal of methotrexate, and high dose corticosteroid treatment. Full supportive treatment is indicated as the prognosis in such patients is good.

Acute Disease↗
PubMed1992

The Oxford club-foot programme.

We treated 63 club feet in 44 patients by a defined programme of strapping from birth followed by one of two operations performed at six weeks, either a simple calcaneal tendon lengthening or a subtalar realignment, and reviewed them prospectively. The decision as to which operation to perform was taken at four weeks after radiographic measurement of the talocalcaneal angle. All but eight patients (ten feet) were followed for a mean of 8.7 years. The overall results after calcaneal tendon lengthening were satisfactory. The re-operation rate after subtalar realignment was high (39%) due to over or undercorrection of the deformity.

Child↗
PubMed1992

Hip dysplasia in hereditary motor and sensory neuropathies.

Hip dysplasia complicating the hereditary motor and sensory neuropathies is not widely recognised. We describe four patients in whom the neuropathy affected the proximal muscles and we suggest that hereditary motor and sensory neuropathies may be responsible for the failure of the initial treatment of some neonatal dislocated hips.

Adolescent↗
PubMed1992

The ossific nuclei and the cartilage anlage of the talus and calcaneum.

We studied the ossific nuclei on radiographs of the feet of three stillborn infants, two with club feet, relating the size, position and alignment of each nucleus to the cartilaginous talus or calcaneum in which it lay. Anteroposterior projections of the nucleus of the talus show deformity of that bone as well as subtalar malalignment. Lateral projections of the calcaneal nucleus may underestimate the degree of hindfoot equinus.

Calcaneus↗
PubMed1979

Antibiotic prophylaxis in total hip replacement.

A controlled prospective trial to compare the efficacy of the antibiotics cephaloridine and flucloxacillin in preventing infection after total hip replacement was conducted at three hospitals. The antibiotic regimens began before surgery, cephaloridine being continued for 12 hours and flucloxacillin for 14 days afterwards. Over an 18-month period 297 patients undergoing a total of 310 hip replacements were entered into the trial and randomly allocated to one of the regimens. The follow-up period ranged from one to two and a half years. All operations were performed in conventional operating theatres; at two of the hospitals these were also used by various other surgical disciplines. Four patients developed deep infection, two having received the cephaloridine and two the flucloxacillin regimen. The overall rate of deep infection was therefore 1.3%. Thus three doses of cephaloridine proved to be as effective as a two-week regimen of flucloxacillin. Giving a prophylactic systemic antibiotic reduced the incidence of infection to a level comparable with that obtained in ultra-clean-air operating enclosures.

Aged↗
PubMed1978

A comparison of four beta-adrenoceptor antagonists in patients with asthma.

1 Cardiovascular and airways response to two non-cardioselective beta-adrenoceptor blocking drugs, propranolol and pindolol (with partial agonist activity) and two cardioselective beta-adrenoceptor blocking drugs, acebutolol (with partial agonist activity) and atenolol, were compared in twelve patients with asthma. 2 All four drugs produced a significant reduction in resting pulse rate and prevented the increase in heart rate following inhaled isoprenaline (1,500 microgram). 3 Seven patients in clinical remission showed no significant bronchoconstrictor response to any of the drugs. In the remaining five patients, bronchoconstriction was greatest following propranolol (mean reduction in FEV1 26.6%) and least following atenolol (mean reduction in FEV1 6.5%). 4 The bronchodilator response to inhaled isoprenaline was blocked by propranolol and pindolol but not by acebutolol and atenolol. 5 Partial agonist activity did not appear to be clinically useful.

Adolescent↗
PubMed1978

Beta-blockers and asthma.

In a single-blind, randomised, crossover study in 10 asthmatic patients, the effects of approximately equipotent oral doses of 3 cardioselective beta-blockers-atenolol (100 mg), metoprolol (100 mg), and acebutolol (300 mg)-and 4 non-cardioselective beta-blockers-proranolol (100 mg), oxprenolol (100 mg), pindolol (5 mg), and timolol (10 mg) upon FEV1 were compared. All drugs, except pindolol, produced a significant reduction in standing pulse rate and prevented an increase in heart rate after inhaled isoprenaline (1500 microgram). All drugs caused a fall in FEV1 but only atenolol did not differ significantly from placebo in this respect. The bronchodilator response to inhaled isoprenaline was blocked by the 4 non-cardioselective drugs; the 3 cardioselective agents permitted some bronchodilatation, but only atenolol did not differ from placebo.

Adolescent↗
PubMed1978

Bronchial responsiveness to inhaled histamine and isoprenaline in patients with airway obstruction.

In order to examine the hypothesis that bronchial reactivity to non-specific constrictor stimuli is influenced by the resting tone of the bronchial smooth muscle, the airway responses to inhaled histamine solution and inhaled isoprenaline were measured in 19 patients with airway obstruction. There was a significant positive correlation between the size of the constrictor response to histamine and the dilator response to isoprenaline (r = +0.83; p less than 0.01) as measured by changes in specific airway conductance. Patients with asthma showed greater bronchial reactivity to both histamine and isoprenaline than those with chronic bronchitis, although some patients had changes intermediate between the two extremes.

Adult↗
PubMed1977

The use of 99mc-EHDP as a scanning agent in the detection of metastases from osteosarcoma.

The early detection of metastatic spread in sixteen patients with osteosarcoma has been studied over a twelve month period, comparing the techniques of bone scanning and radiography. In only two patients were we able to demonstrate changes suggestive of pulmonary metastases any earlier with a 99mTc-EHDP scan than with chest radiographs and one of these resolved spontaneously. However, the bone scan did accurately delineate the extent of the primary tumour and may, therefore, be helpful in deciding the level of the amputation and the response of the patient to treatment, particularly now that chemotherapy and immunotherapy are frequently used in the management of the disease.

Adolescent↗
PubMed1977

Bronchial reactivity: interaction between vagal stimulation and inhaled histamine.

The interaction between the effects of vagal stimulation and inhaled histamine on the bronchi was studied in anesthetized dogs. Reactivity was assessed by measuring changes in bronchial caliber visualized with tantalum bronchograms. In seven vagotomized dogs the bronchoconstrictor response to a combination of electrical stimulation of the vagus nerves and inhaled histamine solution produced a mean reduction in airway diameter (Daw) of 2.21 mm which was significantly greater than the additive results of the two stimuli applied separately (mean decrease in Daw 0.29 +/- 0.91 mm). In three dogs the effect of vagal stimulation was to produce a shift in the dose-response curve to inhaled histamine. These results indicate that the effect of the base-line bronchomotor tone must be considered in the evaluation of the effect of vagal blockade on airway reactivity. An increase in the resting degree of bronchomotor tone may contribute to the hyperreactivity observed in patients with asthma.

Aerosols↗