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Biomedical subjects

D Newham

Publications and source records attributed to D Newham.

8 recordsLinked to original sources
PubMed1990

Postoperative muscle strength.

This study investigates the role of motivation in voluntary strength measurements during the postoperative period. Thirty patients underwent surgery which was deemed minor, intermediate or major in severity. Before operation and on the 4th postoperative day measurement of grip strength, maximal voluntary and maximal tetanic (stimulated) contraction of adductor pollicis and assessment of mood were recorded. These investigations were also repeated on the 7th postoperative day in those who had major surgery. No patient had postoperative complications. Minor surgery had no influence on any of the values. Those who underwent major surgery showed significant reductions in grip strength, maximal voluntary contraction and mood; however, maximal tetanic contraction was unaffected. The results in the intermediate group were similar to the major group, although mood depression was less marked. Real strength of a hand muscle appears to be unaltered even by major surgery, but voluntary muscle force is decreased by intermediate and major surgery, and correlates with the patient's subjective state of well-being.

Adult↗
PubMed1983

Aminophylline and fatigue of adductor pollicis in man.

1. The effect of intravenous aminophylline on the contractility of adductor pollicis has been studied in three subjects both in the fresh state and following the induction of muscle fatigue. 2. Aminophylline had no influence on the frequency-force relationship and relaxation rate of adductor pollicis in the fresh state. 3. Fatigue resulted in a selective depression of the force response to low and moderate frequencies of stimulation and a slight effect on maximum force production 10 and 35 min afterwards. 4. Aminophylline given prior to, during and/or after fatigue did not influence this selective low-frequency fatigue at 10 or 35 min. 5. Aminophylline at the concentrations obtained has no significant effect on muscle contractility or fatiguability in man.

Adult↗
PubMed1981

Contractile function and fatigue of the respiratory muscles in man.

Ventilation depends on the proper functioning of the respiratory muscles. These muscles, like other skeletal muscles, can endure high work loads for only short time periods. The work of breathing in patients with lung disease in increased and it has therefore been argued that respiratory muscle fatigue may develop and contribute to respiratory failure. We have studied the contractile function and fatigue of the sternomastoid muscle and the diaphragm in normal subjects and found that these respiratory muscles have the same contractile properties as limb muscles. If subjected to a high load they develop similar patterns of fatigue. Studies on the sternomastoid muscle in patients with lung disease also confirmed that respiratory stress produces fatigue.

Action Potentials↗
PubMed1981

Variation in circulating immune complex levels with diet, exercise, and sleep: a comparison between normal controls and patients with systemic lupus erythematosus.

Circulating immune complexes (CIC) were measured in 4 normal controls and 8 patients with systemic lupus erythematosus (SLE) by a polyethylene glycol precipitation (PEG) method during a 24-hour period. In all the normal controls levels fell during sleep and after drinking 1 pint (568 ml) of milk and rose before getting out of bed and after moderate exercise. There were also marked differences in the patterns of rise and fall of the CIC levels between the normal controls and patients with SLE. Insufficient account has been taken of these physiological influences in CIC levels in previous studies attempting to relate disease activity to quantitative levels.

Adult↗
PubMed1980

Sternomastoid muscle function and fatigue in man.

1. A technique has been devised to measure the effect of stimulation frequency on the contraction force in an accessory muscle of respiration, the sternomastoid, in man. The frequency/force curve was found to be very similar to that of the quadriceps and adductor pollicis muscles. 2. Fatigue of the sternomastoid due to inspiratory loading or sustained maximum voluntary ventilation resulted in reduced force generation at low stimulation frequencies compared with maximum force. This type of fatigue frequently persisted for several hours. 3. If low frequency fatigue were to develop in patients with pulmonary disease it could have important consequences for the development of respiratory failure.

Electric Stimulation↗