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  • Author or Editor: Walter E. van den Brom x
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SUMMARY

The hepatobiliary dynamics of a 99mTc-labeled derivative of iminodiacetate were investigated in 29 healthy dogs. A 2-compartment model proved to be adequate to describe the hepatic time-activity curve. Model-derived variables for the hepatic accumulation and the biliary excretion and transport were used as a reference for evaluation of a number of commonly used measurements directly derived from hepatic and biliary time-activity curves (graphic variables). The difference between t50(ex) and t95(ex), representing the moments when 50 and 95%, respectively, of the maximal count rate during the hepatic excretory phase were measured, proved to be an adequate graphic variable to quantitate biliary excretion. The use of other graphic variables to quantitate hepatobiliary functions seemed unjustified.

Free access
in American Journal of Veterinary Research

SUMMARY

In 25 dogs with spontaneous cholestatic disease, the hepatobiliary dynamics were evaluated by use of scintigraphy and a 99mTc-labeled iminodiacetate (ida) derivative. Hyperbilirubinemia existed in all dogs, with serum total bilirubin concentration ranging from 6 to 262 (μmol/L. An appropriate compartmental model was used to characterize the liver time-activity curves. Model-dependent variables for hepatic uptake and biliary excretion of radiolabeled IDA were found to reliably represent the underlying physiologic processes. Measurements directly derived from the liver time-activity curves of IDA, representing the moments of accumulation of 50 and 95% of the maximal hepatic activity did not accurately represent the hepatic uptake by being significantly influenced by biliary excretion and by competition of renal excretion. The time-interval between 95% and 50% of the maximal activity in the excretory phase proved to be a quantitative characteristic of bile flow in all instances. Compartmental analysis of 99mTc-ida excretory scintigraphy characterized bile flow quantitatively in clinically normal dogs and in dogs with cholestasis. The method permitted the clinical evaluation of cholestasis based on quantitative, instead of the usual qualitative, and on functional, instead of phenomenologic, criteria.

Free access
in American Journal of Veterinary Research

Abstract

Objective

To study a combined urodynamic technique for assessment of urethral closure and bladder storage function in female dogs.

Animals

20 healthy, adult, sexually intact female dogs of various breeds.

Procedure

Urethral pressure profilometry and continuous urethral pressure registration during high-diuresis cystometry (cysto-urethrometry) were studied in dogs sedated with xylazine. Pressures were measured, using a flexible polyvinylchloride multichannel catheter connected to a perfusion system. Urine production and volume were determined by radionucleotide dilution analysis of urine samples. Urethral pressure profilometry was performed first, followed by cystourethrometry. Maximal urethral pressure and maximal urethral closure pressure of consecutive profiles and their mean values were determined. Closure pressure at its highest and lowest level and at micturition threshold and absolute and relative magnitude of urethral pressure variation were determined in the high-pressure zone of the urethra while the bladder filled, enforced by diuresis. Bladder pressure and volume at the micturition threshold and static compliance also were determined.

Results

Differences in mean and variance between variables listed were not significant. Urethral closure pressure varied from 5 to 67 cm of H2O during bladder storage. So-called unstable detrusor contractions were observed in 6 dogs.

Conclusions

Several variables for the assessment of the dynamics of urethral closure and bladder storage function obtained by the technique reported here are reproducible. Values from this study are considered reference values for further studies.

Clinical Relevance

The reported technique can be helpful in the investigation of complicated urinary incontinence in female dogs. (Am J Vet Res 1996;57:1131-1136)

Free access
in American Journal of Veterinary Research

SUMMARY

In 11 dogs, potentials recorded from the scalp and from the solitary nucleus after stimulation of the glossopharyngeal nerve were compared. The far-field potentials recorded from the scalp consisted of negativity, with peak latency of 2.10 to 3.45 milliseconds (mean, 2.93 milliseconds), followed by positivity, with peak latency of 3.20 to 5.95 milliseconds (mean, 4.86 milliseconds) and duration of 4.65 to 6.95 milliseconds (mean, 5.70 milliseconds). The near-field potentials recorded from the solitary nucleus consisted of positivity, with peak latency of 2.15 to 2.70 milliseconds (mean, 2.45 milliseconds), followed by negativity, with peak latency of 4.05 to 5.05 milliseconds (mean, 4.39 milliseconds) and duration of 4.45 to 5.80 milliseconds (mean, 5.21 milliseconds). Comparison of the far-field potentials (n = 10) with the near-field potentials (n = 5) indicated that polarity of the waves was reversed and that the first peak’s latency was slightly (approx 0.5 milliseconds) longer in the scalp-recorded far-field potentials. Neither the difference in latency of the second peak nor the difference in its duration, measured from the onset of the potentials to the return to the baseline of the activity, was significant. The results strongly suggest that the response in the solitary nucleus evoked by electrical stimulation of the glossopharyngeal nerve is the source of at least part of the scalp-recorded responses to stimulation of the same nerve. The scalp-recorded far-field potentials could, therefore, be characterized as volume conducted from the evoked response in the solitary nucleus.

Free access
in American Journal of Veterinary Research