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Biomedical subjects

J Kurkus

Publications and source records attributed to J Kurkus.

35 records · Page 2Linked to original sources

A search for a defect of proximal transport in denervated kidneys of conscious dogs.

The influence of renal nerves on proximal Na+ reabsorption was studied in clearance experiments with unilaterally renal-denervated conscious dogs prepared by surgical bladder division. Two types of experiments were made : A. maximal water diuresis, and B. Total blockade of distal NaCl reabsorption with ethacrynic acid and chlorothiazide. In maximal water diuresis CH2O + CNa was used as a measure of fluid delivery to the distal nephron. At similar GFR on both sides, the proximal reabsorption estimated as GFR--(CH2O + CNa) was 38.4 +/- 5.6 ml/min for the intact and 35.9 +/- 4.2 ml/min for the denervated kidney (n = 6, difference NS). After distal tubular blockade, proximal Na+ reabsorption calculated as filtered load minus urinary excretion was 3.84 +/- 0.43 mmol/min for the intact and 3.91 +/- 0.36 mmol/min for the denervated kidney (n = 6, difference NS). The fractional reabsorption of NA+ was 64.9 +/- 1.0% for the intact and 66.9 +/- 1.1% for the denervated kidney (difference NS). In contrast to data from renal denervation studies with anaesthetized animals, the present experiments did not show any difference in proximal reabsorption between the innervated- and denervated kidney. We conclude that in absence of anaesthesia renal efferent nerves have no major effect on NaCl transport in dog proximal tubule.

Animals↗

[Therapy of urinary tract infection in kidney insufficiency with cotrimoxazole].

37 patients were 44 times treated with cotrimoxazole for an infection of the urinary tract during a renal insufficiency. The creatinine level in the plasma was in all cases more than 1.5 mg/100 ml. cotrimoxazole (Sulprim, Polfa) was administered at a creatinine level to 3 mg/100 ml in a dosage of 3 times 1 tablet a day. Patients with a creatinine level of more than 3 mg/100 ml received twice 1 tablet a day. The time of treatment was 10-14 days. An effectiveness of the medicament was established in 84% of the cases. The results of the treatment were good in the primary infection as well as in the reinfection. The drug was effective in the majority of the bacteria flora. It is well tolerated and little toxic.

Bacterial Infections↗

Influence of renal denervation on urine concentration in awake and anaesthetized dogs.

The role of renal nerves in urine concentration was studied in clearance experiments with unilaterally renal-denervated dogs prepared by surgical bladder division. Urine concentration was assessed under conditions of: (1) stimulation of ADH release by dehydration or barbiturate anaesthesia; (2) mannitol diuresis, and (3) isotonic saline diuresis. Differences in TcH2O/GFR between the intact and denervated kidney were not significant in any of the experimental groups. However, in dehydrated conscious dogs Uosm of the intact kidney (939 +/- 58 mmol/kg H2O) was significantly higher (P less than 0.05) than that of the denervated organ (806 +/- 51 mmol/kg H2O). In the intact kidney the medullary content of total solutes and sodium per kg wet tissue was 684 +/- 26 mmol and 208 +/- 12 mmol, respectively. This was significantly higher (P less than 0.005) than corresponding values of 581 +/- 23 mmol and 171 +/- 14 mmol per kg wet tissue measured in the denervated organ. We suggest that a slight impairment of urine concentration (lower Uosm) in the denervated kidney of conscious dogs may depend on decreased medullary hypertonicity.

Anesthesia↗

[A new synthetic diet for acute and chronic advanced renal insufficiency].

Nefromin is a specific food poor in protein and rich in calories with addition of vitamins and some trace elements (iron, calcium salts). This food is determined for patients with acute and chronic renal insufficiency. It facilitates the diet therapy of the patients. As the only therapy it improves the general state of the disease of the patient with renal lesion. It lowers the creatinine level, allows a positive nitrogen balance and prevents acidosis.

Acute Kidney Injury↗

Denervated and intact kidney responses to saline load in awake and anesthetized dogs.

The function of the innervated and denervated kidney was examined in clearance studies with unilaterally renal-denervated conscious and anesthetized dogs before and after saline loading. Barbiturate anesthesia distinctly depressed hemodynamics and excretory function of both kidneys and increased the difference between the denervated and innervated organ. In conscious moderately hydrated dogs the denervated kidney excreted slightly more sodium and water, while after saline loading higher excretion was observed on the innervated side. The denervated-to-innervated kidney ratios for UNaV, UNaV/100 ml GFR, and urine flow fell significantly from mean control values of 1.27, 1.27, and 1.20, respectively, to 0.80, 0.87, and 0.77 after extracellular volume expansion. Similar alterations of the ratios were observed in anesthetized dogs, but higher excretion of the denervated kidney persisted after saline loading. It is concluded that the greater natriuretic response of the intact kidney to saline infusion was due to inhibition of sodium-retaining action of renal efferent nerve activity by acute extracellular volume expansion.

Animals↗

Reinvestigation of denervation diuresis and natriuresis in conscious dogs.

The function of innervated and denervated kidney was compared in clearance studies with conscious dogs. The animals were prepared for experiments by unilateral renal denervation and surgical division of the bladder to form two hemibladders enabling separate urine collection from two kidneys. The mean urine flow was 6% higher for the denervated kidney (not significant) while mean differences for osmolar clearance (+ 13%), sodium excretion (+21%) and GFT (+5%) were all significant (P less than 0.05). When corrected to 100 ml GFR, sodium excretion was not significantly higher for the denervated kidney. In most experiments higher sodium excretion on the denefvated side was associated with higher GFR. Thus, contrary to some earlier views, a slight increase in the excretory function which follows denervation of the kidney is demonstrable also in conscious undisturbed animals. The data suggest that increased haemodynamics of the denervated kidney are responsible for higher excretion, but do not exclude a contribution of inhibited tubular reabsorption.

Animals↗

Plasma hormone and renal function changes in unrestrained dogs exposed to cold.

Renal clearances and plasma antidiuretic hormone (ADH), 17-hydroxycorticoids, and norepinephrine were measured in unrestrained dogs before and during exposure to ambient cold (minus 4 to + 4 degrees C). Some dogs were treated with an inhibitor of cortisol biosynthesis, Metopirone, either alone or combined with dexamethasone, a potent glucocorticoid suppressing ACTH release. Plasma ADH increased in the Metopirone-treated group (P smaller than 0.02) but changed little in other dogs. Plasma 17-hydroxycorticoids in untreated dogs rose from a control value of 14.4 plus or minus 1.9 (SE) to 1.82 plus or minus 1.2 mug/100 ml after 20 min of exposure (P smaller than 0.01), an increase comparable with that previously observed in restrained dogs. Plasma norepinephrine increased from 0.98 plus or minus 0.07 to 1.15 plus or minus 0.08 mug/liter (P smaller than 0.01) after 20 min of exposure. Urine flow, C-Cr, and C-PAH tended to increase spontaneously in nonexposed control dogs. Exposure to cold abolished or reversed this tendency, most distinctly in the Metopirone-dexamethasone group. The urine concentration, measured as T-c-H2O/C-Cr, did not change in cold, in contrast to a decrease previously observed in restrained dogs. The data do not support the key role of plasma cortisol elevation in the mechanism of urine-concentration defect in cold and demonstrate important differences between responses of restrained and unrestrained animals.

17-Hydroxycorticosteroids↗

Manganese content of large-volume parenteral solutions and of nutrient additives.

Manganese (Mn) was analyzed by flameless atomic absorption spectrophotometry in a variety of commercially produced solutions and additives commonly used in total parenteral nutrition (TPN). The amount of Mn in preparations tested varied among manufacturers and among lots. It was generally present in very small amounts with amino acid preparations supplying the major portion in the TPN formulas. Among amino acid solutions, Aminosyn 10% had the highest Mn content (5.2-17.0 micrograms/liter) with Veinamine 8%, FreAmine II, 8.5%, Travasol 10%, and Nephramine having less than 6.7 micrograms/liter. Other large volume parenterals contained appreciably less Mn, eg, Dextrose 50% had 0.64-2.5 micrograms/liter. Some of the additives were high in Mn, eg, potassium phosphate--280 micrograms/liter, magnesium sulfate 50%--up to 225 micrograms/liter, and Berocca C--245.8 micrograms/liter but their actual contributions to daily TPN intake was no more than 3.3 micrograms. The calculated Mn content in TPN formulas with varying source materials ranged from 8.07-21.75 micrograms per total daily volume. These values agreed with those obtained from analysis of actual TPN solutions. The values for 10% Intralipid and 20% Liposyn were 0.5 and 3.0 micrograms/liter, respectively.

Adult↗