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Biomedical subjects

K T Nielsen

Publications and source records attributed to K T Nielsen.

4 recordsLinked to original sources
PubMed1992

In vitro effects of bladder mucosa and an enkephalinase inhibitor on tachykinin induced contractility of the dog bladder.

Tachykinin-induced contractility of smooth muscle strips from dog bladders was studied in vitro, and the presence of substance P-like immunoreactivity and neurokinin A and neurokinin B-like immunoreactivity was examined in bladder sections. Nerve fibers with substance P-like immunoreactivity were present in the mucosa, submucosa and smooth muscle. Fibers were also found in nerves, intramural ganglia, and around blood vessels. Neurokinin A-like immunoreactivity had similar distribution, and no neurokinin B-like immunoreactivity was observed. Removal of the mucosa significantly enhanced the sensitivity and the maximum responses to the tachykinins. After removing the mucosa, the sensitivity to these tachykinins increased 0.4 to 0.5 log units (p less than 0.02). The responses to carbachol were not altered by mucosa removal. The leftward shifts of the concentration-response curves for neurokinin A were of similar magnitude after removal of the mucosa, and after pretreatment with phosphoramidon (10 microM), an enkephalinase inhibitor, in the presence of mucosa. However, phosphoramidon did not alter the sensitivity of the bladder strips to neurokinin B, and slightly changed the sensitivity to substance P (0.2 log units). Additional shifts of the substance P and neurokinin A curves to the left were observed in the presence of phosphoramidon when the mucosa was removed (0.6 and 0.5 log units, p less than 0.005). The order of potency for the tachykinins (neurokinin A greater than substance P) was not altered by mucosa removal, addition of phosphoramidon, or both. Neurokinin A was degraded by enkephalinase located in the bladder mucosa and addition of phosphoramidon or mucosa removal resulted in an inhibition or loss of enkephalinase activity. It is concluded that the responses to neurokinin A, which acts on NK-2 type of receptors, prevail on the dog bladder.

Animals↗
PubMed1990

Radical prostatectomy versus expectant primary treatment in stages I and II prostatic cancer. A fifteen-year follow-up.

A fifteen-year follow-up of a prospective, randomized study comparing placebo with radical prostatectomy as the primary treatment of early prostatic cancer is presented. A total of 111 patients with clinical Stage I or II prostatic cancer, normal acid phosphatase levels, and negative findings on skeletal x-ray film were evaluable. Thirty Stage I patients and 20 Stage II patients received placebo only; 31 Stage I and 30 Stage II patients underwent radical prostatectomy. The survival status for 95 patients (86%) was established at the fifteen-year follow-up. No significant differences in crude survival occurred in either stage or in both stages combined. Moreover, the survival curves closely followed reference curves based on expected U.S. mortality for men of comparable ages and races. A statistically significant association between a high Gleason histologic score and poor survival was established. In this study, initial treatment with radical prostatectomy did not yield longer survival than initial placebo treatment alone. However, the findings should be interpreted with caution, since sample size was small and staging procedure was simplified.

Adenocarcinoma↗
PubMed1976

Renal tubular reabsorptive response to hypernatremia.

Renal tubular reabsorptive response to rapid infusions of isotonic saline and 5% NaCl solutions were measured during brisk ethacrynic acid diuresis in anesthetized dogs. When adjustments were made for effects of variations in volume expansion, as indexed by plasma protein concentration ([Pprot]), tubular reabsorption of sodium per unit filtrate volume (TNa/GFR) was found to be significantly and positively correlated with plasma sodium concentration ([PNa]) despite hypernatremia and total body surfeit of sodium. The proportions of sodium and water reabsorbed were also homeostatically inappropriate, since the sodium concentration in the reabsorbate was somewhat in excess of that in contemporary plasma ultrafiltrate. These findings signify that glomerulotubular balance holds when the filtered load of sodium is increased by an increment in [pNa] as well as GFR. It is proposed that the moiety of tubular reabsorption (some 75% of GFR) studied here is more closely related to regulation of volume than of osmolality of sodium concentration, and the primary regulation exerted is on tubular volume reabsorption (bulk fluid reabsorption) rather than on the amount of sodium reabsorbed.

Animals↗