PubMed Health⌕ Search

Biomedical subjects

O Jonsson

Publications and source records attributed to O Jonsson.

At least 109 records · Page 6Linked to original sources
PubMed1977

Metabolism in the hypothermically perfused dog kidney. Incorporation rate of leucine and threonine into proteins.

The incorporation of [14C]leucine and [14C]threonine into kidney cortex proteins was studied during 6 days' hypothermic perfusion of dog kidneys at 8-10 degrees C and during in vitro incubation of dog kidney cortex slices at 37 degrees C. Leucine carbon was incorporated into proteins at a higher rate than threonine carbon both during in vitro incubation of kidney cortex slices and during hypothermic kidney perfusion. The incorporation of leucine and threonine during hypothermic perfusion was linear for 6 days but 50-100 times lower than the incorporation of leucine and threonine in kidney cortex slices at 37 degrees C. During hypothermic perfusion there was a decrease in specific activity of leucine and threonine in the perfusate corresponding to a degradation of proteins which was greater than protein synthesis as calculated from the incorporation of label into proteins. Leucine carbon was recovered in CO2 during hypothermic perfusion and in vitro incubation of kidney cortex slices at 37 degrees C. The incorporation of threonine carbon into CO2 was about 10% of the corresponding value for leucine both during hypothermic kidney perfusion and during in vitro incubation of kidney cortex slices at 37 degrees C. It is concluded that there is a turnover of kidney proteins during hypothermic perfusion with a perfusate containing amino acids.

Amino Acids↗
PubMed1977

Transmembrane fluxes of potassium in dog kidney slices. A quantitation of the effect of warm ischemia.

The effect of warm ischemia on the transmembrane transport of potassium in dog kidney slices was studied by measurement of the uptake of 42K. The requirement for steady-state conditions concerning the intracellular potassium concentration was thereby studied. The total potassium content in the slices was found to be constant between 120 and 180 min incubation at both 25 and 37 degrees C. The cell water calculated from the total tissue water and 14C-inulin space in the dog kidney slices amounted to 38 ml-100 g wet weight-1 at 37 degrees C and 45 ml-100 g wet weight-1 at 25 degrees C and was found to remain constant for the incubation interval 120--180 min. The major part of the tissue uptake of 42K could be described by one single mono-exponential function under these conditions. The transmembrane influx at 37 degrees C calculated by using a modified Keynes formula amounted to 1.70 mmol K+-kg wet weight-1-min-1 after no warm ischemia and to 0.89 mmol K+-kg wet weight-1-min-1 after 2 h warm ischemia. The corresponding values for incubation at 25 degrees C were 1.26 and 0.77 mmol K+-kg wet weight-1-min-1, respectively. In the slices incubated at 25 degrees C, the potassium content was higher and the sodium content lower than in slices incubated at 37 degrees C.

Animals↗
PubMed1977

Transurethral stone extraction with a vibrating basket catheter.

In a recent in vitro study, mechanical vibration was shown to facilitate, considerably, both the passing of a basket catheter beyond an artificial ureteral stone as well as the extraction of a calculus. Therefore, a device by which vibration can be transmitted to the basket of a modified stone extractor was developed for clinical application. The basket moves to and fro with an amplitude of 2-4 mm and a frequency of 40-60 Hz. An experimental follow-up study was performed in dogs to find out whether the vibration procedure as such induced injuries to the ureters. Modified stone extractors were passed up bilaterally into the ureters of 11 dogs. Vibration was applied in a standardized manner to one side, the other non-vibrated side served as a control. Postoperatively, 5 dogs were followed during 4-5 weeks with repeated urographies. Specimens of the ureters were examined microscopically when the dogs were sacrificed. No complications which could be ascribed to the vibration procedure as such were observed. The vibration technique was tried also in a pilot study comprising 14 patients with distal ureteral stones; in 9 patients, the stones were successfully extracted. Of the remaining 5 patients in whom the stone extraction failed, 3 passed the stone spontaneously and in 2 ureterolithotomies were performed. No complications were encountered.

Animals↗
PubMed1977

Blood flow in the calves during surgery.

The volume flow in the calves was measured by means of plethysmography in 14 patients who had a cholecystectomy and in 3 patients who had a wedge biopsy of the breast. The blood flow increased 100% during abdominal surgery, while no change was observed during the extraabdominal operation. When the legs were placed horizontally during cholecystectomy clear signs of venous pooling were observed. Venous pooling in the calves increased when pillows were placed in the popliteal fossae to prevent over-stretching of the knees. Elevation of the legs 20 degrees in the hip joints decreased the venous stasis considerably. Except for intermittent effects on the circulation caused by strong retraction of the intestines, no clear-cut change in the degree of venous stasis was observed during the course of a cholecystectomy.

Adult↗
PubMed1976

Metabolism in the hypothermically perfused kidney. Production and utilization of lactate and utilization of acetate in the dog kidney.

The mechanism for the high lactate production during hypothermic kidney perfusion has not been clarified previously. The metabolism of lactate and acetate was studied in 23 dog kidneys during continuous hypothermic perfusion. The perfusions were performed in a Gambro machine with a perfusate based on human serum albumin. With a perfusate containing fatty acid extracted albumin, which was almost free of fatty acids, the glucose uptake of the kidney was more pronounced than during perfusion with a fatty acid-rich perfusate. The high glucose uptake under this perfusion condition was associated with a lower lactate production and a higher glucose oxidation rate. In perfusions with a perfusate containing lactate at a concentration of 2.5 mmol/l a considerable lactate uptake of the kidney was shown. By isotope dilution technique the production and uptake rate of lactate was estimated at 4.4 and 8.0 mumol/g kidney and day in two experiments. The labeled lactate carbon was recovered in CO2, and glucose in the perfusate indicating a continuous oxidation and gluconeogenesis. Acetate was used by the kidney both for oxidation and for gluconeogenesis. Addition of acetate to the ordinary fatty acid-rich perfusate caused an enhanced lactate production from the perfused kidney. The results indicate that the high lactate production during hypothermic perfusion of kidneys is mainly dependent on a metabolic blockade at the level of pyruvate dehydrogenase.

Acetates↗
PubMed1975

The distribution of sodium in aortic walls from spontaneously hypertensive and normotensive rats.

The contents of exchangeable sodium, bound sodium and total water and the extracellular space of thoracic aortas from normotensive and spontaneously hypertensive rats were measured. The aortas from the hypertensive rats contained more sodium than those from the normotensive animals while the total water content and extracellular space in the two groups were the same. The capacity to bind sodium in an osmotically inactive form was greater in the aortas from the hypertensives than in those from the normotensives. The difference in binding capacity was of the same order of magnitude as the difference in sodium content, indicating that the excess sodium in the thoracic aortas from the hypertensive rats was osmotically inactive and thus unable to cause water logging.

Animals↗