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Biomedical subjects

T N Solie

Publications and source records attributed to T N Solie.

At least 19 recordsLinked to original sources

Gastric myoelectric and motor activity in dogs with gastric dilatation-volvulus.

Electrical and contractile properties of the stomach were assessed in six adult dogs after recovery from surgical treatment for gastric dilatation-volvulus (GDV), a disorder characterized by delayed gastric emptying of the solid phase. Electrodes and strain-gauge force transducers were sutured to the serosa of the antrum and pylorus at the time of surgical intervention for GDV. Ten days after implantation, electrical and mechanical activities were recorded before and after a standardized meal. The analog FM tape recordings of the electrical and mechanical signals were converted to digital time series for analysis by computer. Recordings from dogs after GDV showed increased slow wave propagation velocity in both the fasting and the fed states compared with controls. In addition, the GDV dogs had atypical fasting state phase III activity fronts. We found no difference in gastric slow wave frequency, dysrhythmia, or electromechanical coupling between the two groups. These results indicate that delayed gastric emptying in this syndrome is associated with increased gastric slow wave propagation velocity.

Animals

A programmable stimulator for electrophysiological studies.

We report on the design and construction of a programmable stimulator for use by neuroscientists. The stimulator is small, lightweight, and low powered. It generates positive, negative, or positive and negative pulses with widths and periods programmed by the user. The stimulator has ten parallel outputs to enable it to drive ten preparations at one time. It operates from 50-60 Hz, 115 v AC or 230 v AC and had a nominal peak-to-peak output of 30 volts. A liquid crystal display was used for the user interface and the timing was software-generated by a mincrocontroller.

Electric Stimulation

An analog data acquisition board for the Macintosh II.

The Macintosh II has the hardware to make a good scientific data acquisition and data processing machine. The data acquisition boards currently available do not sample multiple channels simultaneously. They are also relatively slow. We have designed a fast Analog-to-Digital Board for the Macintosh II that samples eight channels at once. This board acquires data with sampling periods from 1 microsecond to 1.6777215 seconds in increments of 100 nanoseconds. Any jitter is due to the stability of the clock which is about one part per billion. The actual analog-to-digital conversion time is 500 nanoseconds with another 500 nanoseconds taken up by the track-and-hold amplifier acquisition time and the multiplexer setting time. The board samples as many as eight channels, giving 12-bit resolution for signals between plus and minus 2.5 volts. For eight channels the maximum Nyquist frequency is 62.5 KHz. The board will acquire single-channel data that has frequencies up to 500 KHz. Simultaneous comparisons of two channels can be made for signals that have a highest frequency component of 250 KHz. Thirty-eight integrated circuits were used on a single-slot board that connects to the Macintosh II's 32-bit NuBus.

Analog-Digital Conversion

Ketamine-acepromazine as an anaesthetic agent for chinchillas (Chinchilla laniger).

Intramuscular injections of ketamine-acepromazine provided satisfactory surgical levels of anaesthesia. Induction was smooth. There was a wide margin of safety with no significant side effects, and there were no deaths attributable to anaesthesia. Induction time was 4-6 min, duration of surgical anaesthesia was 40-60 min, with complete recovery in 2-5 h. 80 chinchillas were used for this study.

Acepromazine

Analysis of nonexponential fluorescence decay data by a method of moments.

A method of moments is presented for the analysis of convoluted fluorescence decay data when the impulse response function is given by f(t) = alpha exp (-At - Bt1/2). Examples of this method are given using both simulated and measured fluorescence decays. It is also shown that this method, used with moment index displacements, will correct for light-scatter leakage, zero-point time shifts, and slow lamp drift.

Benz(a)Anthracenes