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Biomedical subjects

J J Szwed

Publications and source records attributed to J J Szwed.

At least 19 recordsLinked to original sources
PubMed1984

Histamine and protein transport in canine muscle.

The effect of intraarterial histamine infusion on transcapillary protein transport was determined in the constant flow pump-perfused isolated gracilis muscle of the dog. Muscle vascular resistance (MVR), the rate of net transcapillary protein transport (Js), net transcapillary fluid transport (Jv), changes in protein-free transcapillary fluid movement (delta Jo) and rubidium extraction (ERb) were calculated following four experimental manipulations. First, as a control, venous pressure was elevated by 20 mmHg; next, histamine was infused intraarterially; then venous pressure was elevated by 20 mmHg during histamine infusion; and finally, the recovery of the tissue from histamine infusion was determined. Although elevation of venous pressure produced no change in MVR, it significantly increased Js, Jv and delta Jo. Histamine infusion caused a significant decline in MVR, and increases in Js and in Jv. delta Jo did not change significantly. When venous pressure elevation was superimposed upon histamine infusion, MVR did not change; Js, Jv, and delta Jo increased but only by increments similar to venous pressure elevation alone. None of the manipulations altered Rb extraction. At the constant flow used in this study, histamine does not appear to increase either capillary hydrostatic pressure or capillary surface area, so that the small intestine in Js was probably due to a slight increase in capillary permeability.

Animals↗
PubMed1983

Normokalemic nonazotemic adrenal insufficiency.

Two patients had adrenal insufficiency with severe hyponatremia and profound central nervous system symptoms. In both adrenal insufficiency was diagnosed clinically. Neither patient had either hyperkalemia or azotemia.

Adrenal Insufficiency↗
PubMed1982

Mass-balance approach for estimating transcapillary fluid and protein movement.

This study assesses the applicability of a procedure based on mass conservation to estimate transcapillary protein transport (PT) in patients. In a tissue that exhibits net transcapillary protein transport, total transcapillary fluid movement (FMT) is defined according to the law of mass conservation as: FMT = FA (CV - CA)/CV + PT/CV where FA is arterial plasma flow and CV and CA are respectively venous and arterial protein concentration. The first term above (FMO) was estimated from changes in venous plasma oncotic pressure. The second term was estimated both from the rate of tissue accumulation of 125I-albumin and from the mass-balance relationship as (FMT - FMO). FMT was determined in a jejunal segment as the sum of the changes in tissue weight, fluid secretion, and lymph flow. Increasing venous pressure by 10 and 20 mmHg produced changes in FMT and PT which, as estimated by the two methods, were not significantly different. Thus PT can be estimated from the mass-balance relationship without employing either radioactive labels or noxious tissue manipulation; such an approach should be suitable for clinical application.

Body Fluids↗
PubMed1982

The importance of microscopic examination of the urinary sediment.

Urinalysis may provide evidence of significant renal disease in asymptomatic patients. The microscopic urinalysis is vital to making diagnoses in many asymptomatic cases, including urinary tract infection, urinary tract tumors, occult glomerulonephritis, and interstitial nephritis. Three-hundred-fifty-three consecutive urinalyses were performed in our Urinalysis Laboratory to discern the incidence of significant urinary findings not disclosed by macroscopic examination. One-hundred-seventy-two urines had negative macroscopic exams, but 52 of these had positive microscopic findings, an incidence of 30% (52/172). Furthermore, 15% (52/353) of all urines studied revealed significant urinary findings microscopically. An adequate examination of the urine must include a microscopic as well as a macroscopic examination.

Erythrocytes↗
PubMed1980

Hypoxanthine-arabinoside pharmacokinetics after adenine arabinoside administration to a patient with renal failure.

Hypoxanthine arabinoside pharmacokinetics were measured during an adenine arabinoside continuous intravenous infusion and during hemodialysis in a patient with renal failure. Therapeutic guidelines for adenine arabinoside in renal failure are provided based on an elimination half-life of 4.7 h and a plasma clearance of 87.9 ml/min for the hypoxanthine metabolite.

Acute Kidney Injury↗
PubMed1980

Effect of intravenous mannitol on renal hemodynamics and renal lymph recovery during acute ureteral obstruction.

The object of this study was to determine the effect of mannitol upon lymph flow during acute unilateral renal obstruction in the dog--whether it would sustain, increase, or have an adverse effect upon renal hilar lymph flow. Two groups of dogs were used so that the efficacy of bolus injection could be compared with continuous infusion of mannitol. After ureteral obstruction renal hilar lymph flow increased significantly. Renal artery pressure, venous pressure, blood flow, and lymph flow were sustained by both bolus and continuous infusion. These results show that intravenous mannitol given during acute ureteral obstruction will sustain an increase in renal hilar lymph flow.

Acute Disease↗
PubMed1980

Urinalysis and clinical renal disease.

Urinalysis is a simple, efficient, and accurate guide in the diagnosis of renal disease. By determining a patient's history and obtaining a physical examination, the physician is very often able to diagnose a patient's renal lesion. Heavy proteinuria and a microscopic sediment containing red cells and red cell casts strongly suggest acute glomerulonephritis. The causes of this nephropathy are legion. On the other hand, mild proteinuria and a lack of microscopic findings suggest nephrosclerosis, interstitial nephritis, or acute tubular necrosis in the proper clinical setting. When glomerular disease produces nephrotic syndrome, the various types of glomerular disease can be diagnosed accurately without biopsy in a high percentage of cases.

Acute Kidney Injury↗
PubMed1979

Diuretics, hepatic and thoracic duct lymph flows in the dog.

1. Simultaneous thoracic duct and hepatic lymph flows were measured in 29 mongrel dogs before and after the intravenous administration of mannitol, ethacrynic acid, frusemide and chlorothiazide in separate experiments. 2. Thoracic duct lymph flow increased significantly after each diuretic agent was administered. 3. Hepatic lymph flow increased only after ethacrynic acid and mannitol administration. Frusemide and chlorothiazide did not alter hepatic lymph flow. 4. These data show that increases in thoracic duct lymph flow after ethacrynic acid and mannitol arise partly from the liver, as well as from other organs.

Animals↗
PubMed1979

Hypercalcaemia due to hyperparathyroidism in a patient with chronic renal failure and renal carcinoma.

A 65-year-old woman with a history of a left heminephrectomy for renal carcinoma developed hypercalcaemia 11 years after the operation. The same kidney was found to contain a recurrent renal carcinoma. After the radical nephrectomy of the left kidney, hypercalcaemia remitted but reappeared 11 months later. The right kidney was small but functioned at a level of creatinine clearance of 10--15 ml/min. Metastatic work-up was negative, and secondary causes of hypercalcaemia were excluded. A neck exploration revealed a parathyroid adenoma. With parathyroid resection the serum calcium declined to normal, and the risk of hypercalcaemic nephropathy in the remaining kidney was precluded.

Adenoma↗
PubMed1978

Minoxidil treatment of malignant hypertension. Recovery of renal function.

We treated eight severely hypertensive, long-term hemodialysis patients who failed to respond to ultrafiltration or conventional medication with minoxidil rather than with bilateral nephrectomy. Control of blood pressure and relief of symptoms was achieved in all eight. In addition, three of the patients, who were all severely oliguric, recovered sufficient renal function to allow the discontinuation of dialysis. Two are presently doing well, while one died of causes unrelated to uremia or minoxidil therapy. We presently reserve bilateral nephrectomy for those hypertensive dialysis patients who are awaiting transplantation.

Acute Kidney Injury↗
PubMed1978

Prevailing patterns and predictor variables in patients with acute tubular necrosis.

The courses of 276 acute tubular necrosis patients referred for dialysis were reviewed in search for prognostic indicators. Sixty-three percent survived. Of 28 possible predictor variables, a posttoxic cause and nonoliguria were favorable, whereas myocardial infarction and peritonitis affected survival unfavorably. Total pareneral nutrition influenced survival favorably only in those with multiple complications or peritonitis. No single variable or combination predicted a lethal outcome. Since survivors were frequently restored to complete health, we advocate an aggressive therapeutic approach even in the face of multiple complications.

Acute Kidney Injury↗
PubMed1977

Pharmacokinetics of cefaclor in normal subjects and patients with chronic renal failure.

We studied the pharmacokinetics of cefaclor, a new cephalosporin antibiotic, in normal subjects and subjects with chronic renal failure. Cefaclor was largely, but not entirely, eliminated by the kidneys. The cefaclor half-life in normal subjects was 40 to 60 min; in subjects with essentially no renal function, it increased to 3 h. In normal subjects, 50 to 70% of a 250-mg dose was excreted in the urine within 8 h. The linear relationship between the elimination constant and creatinine clearance allowed the construction of a useful dosage modification nomogram.

Animals↗
PubMed1977

Diuretics and small intestinal lymph flow in the dog.

Simultaneous measurements of thoracic duct lymph flow and small intestinal lymph flow were carried out in mongrel dogs after the administration of mannitol, ethacrynic acid, furosemide and chlorothiazide. Thoracic duct lymph flow increased only after injection of mannitol. Intestinal lymph flow increased after injection of all diuretics except chlorothiazide. Furthermore, mannitol produced simultaneous increases in thoracic duct and intestinal lymph flows. The durations of response of the increased lymph flows from each lymph channel produced by mannitol were statistically identical. The durations of increased intestinal lymph flows observed with each drug were: 40+/-3 (S.E.), 43+/-2 and 38+/-2 minutes for mannitol, ethacrynic acid and furosemide, respectively. Mean arterial blood pressures and inferior vena cava pressures did not change from the control to the experimental state in any animal studied. Similarly measurements of serum and lymph sodium, potassium and protein concentrations were unchanged from the control to the experimental state. These studies demonstrate that mannitol simultaneously increases thoracic duct lymph flow as well as intestinal lymph flow. Secondly, the results suggest that the increases in thoracic duct lymph flow after ethacrynic acid and furosemide administration, observed in previous studies arose primarily from the small intestine.

Animals↗
PubMed1977

Intradialytic measurement of cardiac output by thermodilution and impedance cardiography.

Impedance cardiography was compared with thermodilution cardiography in the measurement of cardiac output serially during maintenance hemodialyses in ten chronic uremic patients. Measurements were carried out pre-dialysis and post-dialysis as well as hourly during dialysis. The results demonstrated statistical identity between impedance and thermodilution cardiography at all times of measurement. The study confirms the validity of the non-invasive technique in measuring cardiac output in the uremic patient.

Adult↗
PubMed1976

The acute effects of respiratory and metabolic acidosis on renal function in the dog.

1. Effective renal plasma flow, glomerular filtration rate and cardiac output were measured in osmotically loaded dogs before and during comparable acute respiratory and metabolic acidosis. 2. Urine output increased in control dogs and in animals with metabolic acidosis, but declined with respiratory acidosis. Effective renal plasma flow and glomerular filtration rate declined with respiratory and metabolic acidosis. 3. When respiratory acidosis was buffered with sodium bicarbonate, urine volume increased and glomerular filtration rate and effective renal plasma flow were unchanged; with trihydroxymethylaminomethane, urine volume increased but glomerular filtration rate and effective renal plasma flow fell. 4. When metabolic acidosis was buffered with sodium bicarbonate, urine volume increased; with trihydroxymethylaminomethane, urine volume increased but glomerular filtration rate fell. Cardiac output declined only during metabolic acidosis, both buffered and unbuffered. 5. These studies demonstrate that, even with osmotic loading: (1) respiratory acidosis caused a decrease in glomerular filtration rate, effective renal plasma flow and urine volume; (2) metabolic acidosis depresses glomerular filtration rate and effective renal plasma flow but does not change urine volume even though cardiac output falls; (3) sodium bicarbonate is mor effective than trihydroxymethylaminomethane in preserving renal function during respiratory and metabolic acidosis.

Acidosis↗