Several radionuclide parameters are routinely used for the diagnosis of renal obstruction. In order to evaluate the sensitivity of those parameters, an experimental model of partial ureteral obstruction in rats was used. Neither the cortical transit time, nor the response to furosemide could serve to discriminate between obstructive and nonobstructive kidneys. These parameters were, however, more or less related to the degree of impairment of the single kidney glomerular filtration rate and should probably be considered as functional parameters reflecting the grade of the obstructive phenomenon.
To see if oral dipyridamole increases peritoneal clearances in humans undergoing peritoneal dialysis, two types of double-blind clinical studies were undertaken. In a single-dose study, 7 patients were randomized to take dipyridamole or placebo early in a peritoneal dialysis with 2 L, hourly cycles; later in the same dialysis a crossover administration was studied. In a multidose study, 17 patients were randomized to take dipyridamole or placebo three times daily and clearance studies were performed on days 1, 4, and 8 during 2 L, hourly peritoneal dialysis cycles. Neither the single dose of dipyridamole or placebo significantly altered drainage volumes, clearances, or dialysate protein from control periods. In the multidose study, mean values on dipyridamole or placebo were not significantly changed from respective baseline predrug values. Mean values with dipyridamole and placebo usually were not significantly different. Dipyridamole did not appear to improve peritoneal clearances even with repeated ingestion.
Diagnosis of renovascular hypertension is of particular interest because it is curable by vascular surgery or percutaneous transluminal angioplasty (PTA). Transvenous digital subtraction angiography (DSA) is a minimally invasive method of importance in detecting renal hypertension of different origins (pre-, intra-, postrenal). This study was carried out to assess the value of transvenous DSA in analyzing the renal arteries and renal parenchyma, in detecting renal artery stenosis, and in controlling PTA results. Our results demonstrate that image quality of transvenous DSA of the renal arteries was excellent (diagnostic in 474 of 510 cases, 93%). A large number (62%) could be analyzed following one injection of contrast medium, in 25% a second, and 6% a third injection was necessary. In follow-up studies after PTA (1 week to 24 months) patients with normalized blood pressure values (16/33) had a completely reopened arterial segment and normal parenchyma of both kidneys. In persistent or recurrent hypertension (17/33) restenosis could be detected by transvenous DSA in 2 cases and renal parenchymal lesions in 8 cases. Reversible intimal dissections observed immediately following PTA had no influence on blood pressure results. Intra-arterial DSA is recommended when renal artery stenosis is to be evaluated for PTA and when the result of balloon catheter dilatation is to be evaluated. Intra-arterial DSA is indicated to exclude stenosis following kidney transplantation and to determine perfusion of the graft (parenchyma and venous return) taking advantage of small volumes and concentrations of contrast material made possible by digital contrast enhancement.
The effects of an oral protein load, consisting of 1.5 g/kg body weight as cooked red meat, on: serum creatinine (SCr); glomerular filtration rate (GFR) ([125I]iothalamate clearance); and "renal functional reserve" (test-baseline GFR) (RFR) were evaluated in two groups of patients with solitary kidneys (SK). Group 1 had 7 patients with SCr of 1.00 to 1.40 mg/dl. Group 2 had 7 patients with SCr of 1.40 to 3.00 mg/dl. SCr and GFR were recorded during the 4 hours preceding and the 4 hours following the protein load. SCr rose significantly in both groups after protein load (from 1.16 to 1.19 mg/dl in Group 1, from 1.65 to 1.80 mg/dl in Group 2). GFR changes were: from 114.8 to 195.5 ml/min, from 59.0 to 107.7 ml/min, respectively in the two groups. The RFR was smaller in SK patients with early renal failure (ERF) (Group 2), 48.70 ml/min, than in those with normal renal function (Group 1), 80.77 ml/min. However, despite the smallest RFR, SK patients with ERF had the highest percentage increase in their GFR. In conclusion, in SK patients a hemodynamic adaptation to protein intake is present at different levels of renal function, and further studies are necessary to establish whether protein intake should be monitored in these patients.
(1985). Digital Subtraction Angiography (DSA) and other Noninvasive Methods for Evaluation of Renal Circulation and Hypertension. Uremia Investigation: Vol. 9, No. 2, pp. 231-241.
Eight patients with end-stage renal disease (ESRD) who developed bacterial infection of the perirectal area or perineum are reported. The diagnosis was not always straightforward. Bacteremia was seen in 3 of 8 patients and one of these died. Careful examination of the anus, rectum, and perineum should be mandatory in ESRD patients with undiagnosed fever. Treatment consisted of extensive surgical debridement and drainage along with antimicrobial therapy.
Brown-Norway (BN) rats immunized with renal medulla from Sprague-Dawley (SD) rats developed a renal lesion characterized by focal interstitial and perivascular mononuclear cell infiltrates without glomerular involvement. The cellular infiltrates were extracted from the affected kidneys and determined to consist of monocytes 64 +/- 4% (mean +/- S.D.) and T cells 2 +/- 9%. IgG antibodies directed at tubular basement membrane and tubular cell antigens were found in the affected kidneys and in circulation. Sera of immunized rats were used in in vitro studies to determine the presence of antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). In the CDC there was cytolysis of SD kidney and spleen cells but not BN kidney cells. In the ADCC there was significant lysis of BN kidney cells as well as SD kidney cells. Antibodies have been raised in the immunized rats against major histocompatibility (MHC) antigens as well as against autologous tubular cells. The finding of monocytes bearing Fc receptors among the infiltrating cells, as well as antibodies that can function in an ADCC indicates the presence of a combined immune effector mechanism that might be operative in tubulointerstitial nephritis.
Ultrasound examination of a renal transplant was performed in 27 patients over a period of 28 months; there were kidneys from 12 living and 15 cadaveric donors. The ultrasonic scans were performed over a period ranging from 2 days to 12 years following transplantation. We were able to observe and describe the echographic findings of the normal evolution of a well functioning renal transplant, acute tubular necrosis, acute and chronic rejection, perirenal fluid collection, and obstructive uropathy. Ultrasound evaluation of renal transplant was accurate in the diagnosis of postoperative complications together with clinical and laboratory findings. Ultrasound imaging is independent of renal function and can be performed quickly as often as necessary. Percutaneous procedures, including fine needle aspiration, biopsy, aspiration of fluid collection, and positioning of the pyelostomy catheter can be performed under ultrasonic guidance.
One standard continuous ambulatory peritoneal dialysis (CAPD) infusion/drainage system was found prone to recurrent mechanical failure at the junction between the silastic catheter and the titanium connector. This resulted in slackening and eventual disconnection with attendant risk of bacterial entry and a CAPD-associated peritonitis. A simple "lock-ring" device, when fitted over the catheter-titanium connector junction, afforded a secure joint.
Since 1980 we have refined a procedure for renal needle biopsy with continuous ultrasonic guidance (USRNB) which facilitates control of the needle progression through the soft tissues to the lower pole of the kidney. The advantage of this method is evident in a selected population (major obesity, small kidneys). We compared this procedure to the conventional blind biopsy in a series of 32 nonselected patients. Tissue samples with more than 10 glomeruli were obtained in 87% of patients with 2.8 punctures using USRNB, the difference was significant when compared to a blind technique (56%, 4.0, respectively, p less than 0.05). USRNB has been performed in 108 patients with 2 failures due to a poor echographic contrast. Reasons why this procedure should be substituted for the blind technique include: (i) Less morbidity, (ii) improvement of the quality of renal tissue, (iii) better comfort for both patient and physician, and (iv) less technical restriction of the biopsy indication when compared to blind renal needle biopsy.
In this study, 53 children suffering from recurrent urinary tract infections were investigated both by ultrasound and direct radionuclide voiding cystography (RNVC). The findings were: Most high-grade vesicopelvic refluxes were detected by both methods consistently. Discrepant results of high-grade vesicopelvic refluxes were seen in 6 kidneys from 4 children. Main advantages of RNVC are the quick results and the ease of interpretation of these results. In RNVC the whole urinary tract can be observed during the filling phase as well as during the voiding and postvoiding phase. In sonography, the different parts of the urinary tract must be explored one after another during the filling, voiding, and postvoiding phase. The investigation by sonography is time consuming and a strongly investigator-dependent procedure.
In hypothyroid rats (TX), the isotonic fluid reabsorption (Jv), that is closely linked to the transepithelial sodium transport (JNa), is impaired. The administration of physiological doses (10 micrograms/kg body weight per day) of tri-iodothyronine (T3) doubles Jv in three days (TX+T3). This phenomenon could be explained by several mechanisms: a direct stimulation of Na-K-ATPase, an increase in the Na+ entry step, changes in the permeability properties of the luminal and/or basal lateral membranes. Using a kinetic microassay, Na-K-ATPase activity was measured in early (S1) and late (S2) proximal tubules segments isolated from control, TX, and TX+3T3 animals. In TX rats the enzyme activity was lower (70%) in both segments versus control rats, it remained unchanged after 3 days, and it increased after 7 days of T3 substitution. The Na+ permeability of brush border membrane (BBM) vesicles isolated from TX and TX+T3 rats was identical. However the valuation of the K+ membrane permeability by in vivo perfusion of the lumen and peritubular space of proximal tubules of TX rats, with perfusate containing the K+ ionophore valinomycin (1 microgram/ml), induced a significant increase in Jv that accounted for 40% of that elicited by T3. Taken together, the in vivo and in vitro experiments suggest that the early effect on Jv of physiological doses of T3 cannot be explained by a direct action of T3 either on the Na+ entry step across the BBM or on the Na+ exit step (i.e., the Na-K-ATPase), but rather by an increase in K+ permeability of proximal tubular cell membranes.(ABSTRACT TRUNCATED AT 250 WORDS)
The uptake of phosphate [expressed as phosphorus (P)] by the anion exchange resins, Dowex 1-X8, Dowex SBR, and Bio-Rex 5, aluminum hydroxide, and sucralfate tablets was evaluated. The maximum uptake capacities (in mg P per gram of "wet" resin or solid) were 56, 49, and 84 mg for Dowex SBR, Dowex 1-X8, and Bio-Rex 5 resins, respectively, and 164-168 mg for aluminum hydroxide and sucralfate. At a concentration of P considered to approximate that encountered in the stomach (0.3 mg/ml), Bio-Rex 5 resin, aluminum hydroxide, and sucralfate bound similar amounts of P. Physiologic concentrations of bicarbonate or chloride and simulated gastric or intestinal fluids caused small changes in P uptake by Bio-Rex 5 resin. The resins bound large quantities of taurocholic (TA) and glycocholic (GA) acids. However, when Bio-Rex 5 was converted to the taurocholate form, it bound the same amount of P as the original chloride-form resin, and the binding of TA was prevented.
Schlegel and Gates described an isotopic method for the measurement of global and separated glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) based on the determination by scintillation camera of the fraction of the injected dose (99mTc-DTPA-[131I]hippuran) present in the kidneys 1-3 min after its administration. This method requires counting of the injected dose and attenuation correction, but no blood or urine sampling. We validated this technique by the simultaneous infusion of inulin and polycyclic aromatic hydrocarbon (PAH) in patients with various levels of renal function (anuric to normal). To better define individual renal function we studied 9 kidneys in patients either nephrectomized or with a nephrostomy enabling separated function measurement. A good correlation between inulin, PAH clearance, and isotopic GFR-ERPF measurement for both global and separate renal function was observed.
A method of [123I]hippuran (OIH) renogram evaluation is proposed, which delivers transition rates for total and split renal clearance. It is based on the reconstruction of the true kidney input, using an equation of balance and a two-compartment model assumption of OIH kinetics. Results are compared with clearance determinations using whole body principles and transit time determination by deconvolution. It is shown that the reconstructed true input corresponds to the plasma activity while the vascular volume of distribution corresponds to the blood.
Urinary excretion of lactate dehydrogenase (LDH), glutathione-S-transferase (GST), leucine arylamidase (LAS), gamma-glutamyltransferase (GGT), beta-galactosidase (GAL), beta-N-acetyl-D-glucosaminidase (NAG), sodium, and glucose were determined in female Sprague-Dawley rats the subsequent three days after intraperitoneal treatment with single doses of 4.5 mg CdCl2 X 1H2O/kg, 20 mg Na2CrO4/kg, and 0.75 mg HgCl2/kg body weight. Although the pathological effects were localized within the same part of the nephron (i.e., the proximal tubule), there were marked differences with regard to the extent and time course of the parameters affected. Treatment with cadmium resulted essentially in a marked decline in sodium and glucose excretion. The administration of chromate led to a slightly to moderately elevated excretion of the enzyme activities measured with the cytosolic LDH as the most increased enzyme (ca. 500% of controls on Day 3 postadministration). Median glucose excretion was unaffected whereas sodium excretion was transiently reduced. The maximum of enzyme excretion after HgCl2 was essentially the same on the first day postadministration and the amount of enzyme activity in urine up to 20 times higher compared to that after chromium. Sodium excretion was below that of controls on Days 2 and 3, whereas glucose excretion was markedly elevated (up to 8000% of controls). The results indicate that it is possible to discriminate with the use of selected urinary enzymes, substrates, and electrolytes various kinds of nephrotoxic actions not only in different but also within the same part of the nephron.
Urinary proteins were studied in patients after kidney transplantation during various functional states (normal function, acute rejection, chronic rejection) by two-dimensional polyacrylamide gel electrophoresis. In the first dimension, the proteins were separated according to their electric charge by isoelectric focusing, and in the second dimension according to their molecular weight by sodium dodecyl sulfate polyacrylamide gel electrophoresis. After electrophoresis the proteins were visualized using a highly sensitive silver stain technique. The combination of these methods allowed the discrimination of up to 250 protein spots in human urine, most of them unidentified up to now. Functional changes of the kidney transplants were accompanied by complex changes of the protein pattern in urine. These changes cannot be simply compared to the tubular and glomerular pattern of proteinuria which can be identified by one-dimensional sodium dodecyl sulfate electrophoresis. The 2D electrophoresis of urinary proteins may develop into a useful tool in localizing of kidney damage and in the evaluation of renal disease.
Azathioprine and prednisolone may lead to intolerable long-term side effects in some patients with a renal allograft. We have converted 9 patients with stable grafts but severe side effects from conventional immunosuppression to cyclosporine alone. While the steroid side effects largely resolved and there were no problems with acute rejection associated with conversion, the long-term follow up of these patients has demonstrated a number of problems. The average follow-up period since conversion is now 2 years: 2 patients have died, 2 grafts have been lost, and 1 patient required conversion to azathioprine. Chronic nephrotoxicity, gout, indomethacin-induced acute oliguria, and squamous cell carcinomas were the most troublesome effects seen. The disadvantages of conversion outweigh the advantages in most of the patients that we converted.
Urinary kallikrein excretion was evaluated in 85 normal subjects and in 149 uncomplicated and recently diagnosed essential hypertensive patients. Moreover, the possible interrelationships between urinary kallikrein excretion and age, sex, electrolyte excretion, and plasma renin activity were examined. In patients with essential hypertension, urinary kallikrein excretion was similar to that of normal subjects. In these patients the enzyme was weakly and positively related to urinary potassium and plasma renin activity; no correlation was found with blood pressure, urinary sodium, age, or sex. In normal subjects and in patients with essential hypertension, the variables studied account for only 25% and 17%, respectively, of the variability of urinary kallikrein excretion. We conclude that the relatively short duration of hypertension in our patients may explain the unaltered values of urinary kallikrein excretion with respect to controls.
