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Biomedical subjects

B W Watson

Publications and source records attributed to B W Watson.

10 recordsLinked to original sources

The effect of temperature on canine papillary muscle.

Measurements of the total duration, tA, of the action potential for canine papillary muscle in the temperature range 25-45 degrees C are shown to follow the law ta = tau exp (Q/kBT), with tau and the activation energy Q independent of temperature, T, and kB equal to Boltzmann's constant. The value obtained for Q = 0.65 +/- 0.10 eV. Results are also presented for the temperature dependence of points V(x) on the action potential curve, where x is the percentage of repolarisation within the range 30% less than x less than 100%.

Action Potentials

The contingent negative variation and psychological findings in chronic hepatic encephalopathy.

Early diagnosis of chronic hepatic encephalopathy (CHE) in the latent stage before the appearance of clinical signs, should reduce both morbidity and mortality as deterioration is often preventable by treatment. Since existing diagnostic procedures are inadequate, we have investigated a test in which morphine is used as a provocative agent and any resulting change in cerebral function assessed by measurement of the CNV in conjuction with a psychological trail test. Twenty six patients were studied, 6 of whom had clinically overt CHE. A significant correlation (P less than 0.05) between the change in CNV amplitude with morphine and the initial CNV amplitude, consistent with the theoretical model of Tecce (1972), was found. However, the CNV and trail test results taken as a whole did not allow even those patients with overt CHE to be distinguished and we conclude that it is unlikely that differing degrees of latent CHE could be detected.

Chronic Disease

Effect of long-term ionized air treatment on patients with bronchial asthma.

Seven patients with bronchial asthma requiring continuous medication were subjected to eight weeks of nocturnal exposure to negatively ionized air, and their progress was followed using objective tests of lung function and clinical assessment. During exposure, four patients showed significant increases in morning PEFR, which in two of these patients was not sustained when exposure ceased. In two patients the observed increase in PEFR was accompanied by subjective improvement. From the results of all our assessments we conclude that, although this treatment may lead to an improvement in some patients with asthma, further objective studies are required to determine the value of negatively ionized air in the routine management of asthma.

Adult

Theory of hydrokinetic clearance of bacteria from the urinary bladder. I. Effect of variations in bacterial growth rate.

If the bladder is regularly emptied in appropriate circumstances the concentration of bacteria in successively voided samples progressively falls. By making a number of assumptions about conditions of bacterial growth in the bladder the way in which this washout of bacteria will occur can be predicted. Such predictions give a form of washout curve which differs significantly from that commonly encountered in patients. The shape of the predicted washout curve is affected by the form of the bacterial growth curve but this influence is not sufficient to account for the observed difference between patients and predictions.

Bacteriuria

Theory of hydrokinetic clearance of bacteria from the urinary bladder. II. Effects of "bound" organisms and diuresis.

When patients with urinary infection drink large volumes of water and empty the bladder at frequent regular intervals, the concentration of bacteria in the voided samples commonly falls rapidly at first and then remains almost constant. The present theoretical analysis leads to the conclusion that the rapid initial fall in concentration is a function of diuresis and that the subsequent constant output originates from bacteria bound to multiplication sites on the uroepithelium from which their progeny are shed into the urine.

Bacteriuria

Electrical potential difference between basal cell carcinoma, benign inflammatory lesions and normal tissue.

Measurement of the resting electrical potential difference on the surface of the skin has been made on patients with suspected basal cell carcinoma. It was demonstrated that in fifty-five lesions from forty-nine patients, the mean electrical potential difference from thirty-six basal cell carcinomas was found to be +II mV, from nineteen benign inflammatory lesions it was found to be +2 mV, and from normal skin, contra-lateral to the lesions in both groups, it was found to be -3 mV. All the measurements are relative to a reference electrode placed under the tongue. The difference between the means for the inflammatory lesions and for the normal skin was found to be statistically insignificant, but the difference between these means and the mean potential difference for the basal cell carcinoma group was found to be highly significant (P less than 0-1%). However, the populations overlap to such an extent as to make the measurement, in its present form, useless as a diagnostic technique.

Basal Cell Carcinoma

The Departments of Medical Eelectronics, St. Bartholomew's Hospital--the first ten years.

The organisation of an electronics department required to support the work of a large teaching hospital is described. The research and development programme involves the interaction of graduates from many disciplines since problems can emerge from any of the specialities, for example general surgery, obstetrics and gynaecology, clinical neurophysiology. Examples from the research and development programme of the department are described in order to illustrate the range of medical electronic techniques needed to provide adequate support for the clinical research programmes which have received support from the Joint Research Board of the Hospital and Medical College.

Biophysical Phenomena