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Biomedical subjects

C Browning

Publications and source records attributed to C Browning.

29 records · Page 2Linked to original sources
PubMed1990

The use of intraluminal strain gauges for recording ambulant small bowel motility.

Perfused-tube manometry has hitherto been the standard technique for recording intraluminal intestinal pressure in humans, but it is unsuitable for ambulant use. The aim of our study was to evaluate the ability of resistive strain gauge transducers attached to a fine catheter to detect pressure change. Simultaneous strain gauge and perfused-tube manometry was performed on six fasting subjects; in four, strain gauge activation was continuous and in two, the transducers were activated in a pulsed mode with data encoded as a pulse train with an approximate frequency of 20 Hz. Eight thousand eight hundred eighty-eight pressure waves were recorded by strain gauge, of which 96% were detected by perfused-tube manometry. There was good agreement in both phases II and III of the migrating motor complex. The amplitude of pressure waves recorded by strain gauge was slightly but significantly greater. A proportion (14-17%) of pressure waves recorded by strain gauge were bifid; this was not seen with the perfused tube. These differences are best explained by the greater sensitivity and more rapid rise time of the strain gauges. There was no loss of fidelity in the pulse-interval recording mode. A seventh subject underwent a continuous 72-h recording with the strain gauge catheter attached to a battery-operated encoder and magnetic tape cassette recorder and was freely ambulant during this period. The procedure was well tolerated and motility patterns could be clearly identified. We conclude that intraluminal strain gauge catheters are suitable for prolonged use in ambulant subjects and produce data that are closely comparable to the data acquired from perfused-tube manometry under laboratory conditions.

Adult↗
PubMed1987

Therapeutic issues and intervention strategies with young adult lesbian clients: a developmental approach.

This paper examines the coming out process within an adult developmental context. Therapeutic issues which surface for the young adult lesbian client include separation from parents, development of social support, exploration of career/vocational goals, and the establishment of intimate relationships. Intervention strategies are suggested which facilitate the coming out process and help the client integrate her sexual orientation within her emerging adult identity.

Adolescent↗
PubMed1986

Measurement of intracellular pH with microelectrodes in rat kidney in vivo.

The construction of two types of double-barreled microelectrodes of sufficiently small tip size to record cytosolic pH (pHc) in renal tubular epithelial cells is described. Mean pHc in control anesthetized rats was 7.10 and mean basolateral membrane potential (Em) was -51.8 mV. These results suggest that hydrogen ions are actively extruded from either or both poles of the proximal tubular cell but that bicarbonate exit across the basolateral membrane is passive. In animals treated with acetazolamide, pHc was significantly elevated (mean 7.35) but Em was unchanged, suggesting that proton extrusion continues but that the rate of reaction of OH- with CO2 is diminished due to carbonic anhydrase inhibition. A pH higher than that of arterial blood was obtained from sites presumed to be in the interstitium. The evidence for the various assignments of microelectrode tip position is discussed.

Acetazolamide↗
PubMed1983

Receiving, decoding and noise limiting systems for a new pressure-sensitive ingestible radio telemetric capsule.

A new pressure-sensitive radiotelemetric capsule for recording intraluminal pressures within the human gastrointestinal tract has been developed; this capsule employs a pulsed mode of operation. Data recording as a pulse train greatly simplifies problems encountered hitherto in this field, but has produced the requirement for a decoding system which, on tape replay, will reproduce the original pressure change. A system is described here which, in addition to producing an analogue signal from the recorded pulse train, will also eliminate artefacts due to either spurious radio signals or variations in magnetic tape transport speed; it also provides a sensitive and accurate indication of transient signal loss.

Capsules↗
PubMedDate not supplied

Rickets in premature infants receiving parenteral nutrition: a case report and review of the literature.

There is a multifactorial etiology for rickets in premature infants receiving total parenteral nutrition. As an example of this, we describe a premature infant fed almost exclusively parenterally for the first 8 months of life who developed biochemical and radiologic evidence of rickets despite receiving vitamin D, calcium, and phosphorus at presently recommended levels. From our experience and a review of previous literature, there appears to be considerable uncertainty regarding the intravenous requirements of calcium, phosphorus, and vitamin D, particularly in low-birth weight infants. Therefore, measurements of serum 25-hydroxyvitamin D levels, vitamin D, and mineral intakes, and calcium and phosphorus excretion might be clinically useful for monitoring premature infants receiving total parenteral nutrition. Further research delineating more precisely the vitamin D, calcium, and phosphorus requirements of such infants is also suggested.

Calcium↗
PubMedDate not supplied

Fascicular conduction disturbances following aortocoronary bypass surgery: the role of hypothermia versus potassium-arrest cardioplegia.

Two hundred and sixty six consecutive patients who underwent aortocoronary bypass surgery at our institution were studied to assess the incidence of developing new fascicular conduction disturbance. The first 66 patients (Group I) were operated on using systemic hypothermia and ventricular fibrillation while the next 200 patients (Group II) were operated on using systemic hypothermia plus 4 degrees C potassium cardioplegia. Twelve patients in Group I (18%) developed new fascicular conduction defects, an incidence similar to previous studies of patients operated on using similar conditions. A significantly higher incidence of new fascicular conduction defects occurred in Group II patients where 87 patients (43.5%) developed new defects (p less than .001). The most likely explanations for the marked increase in fascicular conduction defects in Group II patients were either local effects of high concentrations of potassium on the conduction system or excessive cooling of the posterior wall of the heart.

Adult↗