Separate Kidney Function Research Articles

SCANNING ELECTRON MICROSCOPE: POSSIBILITIES FOR STUDYING KIDNEY DISEASES

Currently, due to the intensive development of high-tech science-intensive medical and research devices, more and more attention is paid to the development of diagnostics of rare and difficult to diagnose diseases. It is known that among numerous nephropathies, hematuria may be the only symptom of kidney and urinary tract diseases, which complicates their diagnosis and treatment. In order to develop new approaches for the diagnosis of nephropathies, the authors have been studying the morphology of red blood cells in the blood and urine of children and adults using a scanning electron microscope for several years. The paper presents the results of studies of children with various kidney diseases, including IgA-nephropathy, and chronic glomerulonephritis. Scanning electron microscopy was used for the first time to detect nanoparticles on the surface of red blood cells, the size of which is comparable to the size of viruses, which became the basis for one of the authors ' assumptions, namely, the possible transport of certain types of viruses by red blood cells. Thus, some kidney diseases could be considered virus-associated. This paper presents for the first time the results of determining the glomerular filtration rate of both kidneys separately in the study of separate kidney function and of the study of urine smears obtained during catheterization of the ureters in patients with hydronephrosis of one of the kidneys by scanning electron microscopy. As in previous studies, nanoparticles were found on the surface of red blood cells, which leads to the conclusion about the possible viral nature of the disease of the considered patient. In addition, smear images obtained using a microscope showed a significant difference in the elements of the right and left kidneys urine, which did not contradict the data on the study of glomerular filtration rate. According to the authors, the capabilities of the scanning electron microscope can be applied in fundamental research of kidney diseases at the cellular and molecular levels, forming new ideas about their origin, as well as on the basis of which new methods of non-invasive diagnostics can be built.

Sergey Petrovich Fyodorov (1869–1936) — an outstanding Russian surgeon and urologist (the 150th anniversary of the birth)

The article is devoted to the 150th anniversary of the outstanding russian physician, scientist and health care organizer Sergey Petrovich Fedorov (1869–1936). As head of the department of hospital surgery at the Military Medical Academy from 1903 to 1936, S.P. Fedorov made an invaluable contribution to many areas of surgery, and especially to urology. For the first time in Russia, S.P. Fedorov performed cystoscopy with ureteral catheterization and proposed a method for determining a separate kidney function – an indigo carmine test. Also he was the first in our country who performed a suprapubic adenomectomy. On top of that he developed a renal clamp bearing his name. In 1907, in St. Petersburg, the first urological society in Russia was established on the initiative of Fedorov. In 1923, on his initiative, the publication of the journal Urology was launched. These and other achievements of S.P. Fedorov forever immortalized his name among the most prominent representatives of the medical science of our country. In 1907, on the initiative of S.P. Fedorov in St. Petersburg was created the first Russian urological society. In 1923 he initiated the publication of the journal “Urology”. These and other achievements of S.P. Fedorov forever immortalized his name among the most outstanding representatives of medical science of our country.

Primary obstructed megaureter (POM) in children

The aim of this study was to analyze the results of surgical and conservative treatment of non-refluxing POM. In the period 2000-2009, 45 children (52 ureters) were treated, the average age was 5.8 months (±10.33), 24 children (26 ureters) by surgery (I) and 21 children (26 ureters) by conservative means (II). The average follow-up period was 73.8 (±32.91) and 30.85 months (±23.1) resp. Urine examination, USG, DTPA99mTc, biochemical testing, micturating cystouretography in all patients were performed. Significant difference was present in the occurrence of hydronephrosis of 0th, 3rd and 4th grade, p10 mm, p<0.01; and in the occurrence of normal and prolonged time T ½, p<0.01. The health condition was adjusted in 13 (54.20 %), improved on DTPA99mTc in 5 (20.85 %), non-improved in 3 (12.50 %), deteriorated in 1 (4.15 %) and unknown in 2 (8.3 %) patients. In the IInd group a significant difference was in case of occurrence of hydronephrosis of 0th, 2nd and 3rd grade, (p<0.01, or p=0.037 and p=0.011) and in occurrence of normal ureter, with ureter 0-5 mm and dilated ureter 5-10 mm, p<0.01. The condition at the end of the follow-up period was assessed DTPA99mTc as adjusted in 11 (52.39 %) patients, improved in 6 (28.57 %), unimproved in 3 (14.28 %) and no patient was assessed as having deteriorated and unknown in 1 (4.76 %). In patients with an impaired separate kidney function, early surgical treatment helps to minimize damage to the kidney function and prevents future complications (Tab. 6, Fig. 3, Ref. 32).

CONTRAST ENHANCED SPIRAL COMPUTERIZED TOMOGRAPHY IN PATIENTS WITH CHRONIC OBSTRUCTIVE UROPATHY AND NORMAL SERUM CREATININE: A SINGLE SESSION FOR ANATOMICAL AND FUNCTIONAL ASSESSMENT

We evaluated contrast enhanced spiral computerized tomography (CT) as a single session for the anatomical and functional assessment of patients with chronic obstructive uropathy and normal serum creatinine. The study included 65 patients with unilateral or bilateral chronic renal obstruction and normal serum creatinine. Five patients had bilateral obstruction and the remaining 60 had unilateral obstruction and a normal contralateral kidney. Therefore, the total number of renal units was 130, that is 70 obstructed and 60 normal. All patients underwent contrast enhanced spiral CT together with excretory urography (IVP) and Tc-mercaptoacetyltriglycine renal scan. CT was used to identify the cause of obstruction and selectively determine the glomerular filtration rate (GFR) of the 2 kidneys. The diagnostic accuracy of CT for identifying the cause of hydronephrosis was compared with that of IVP. Moreover, a correlation was made between CT GFR and isotope GFR. Obstruction was caused by ureteropelvic junction narrowing in 25 cases, ureteral stones in 21, ureteral stricture in 20 and extrinsic ureteral obstruction in 4. Contrast enhanced spiral CT identified the cause of hydronephrosis in all obstructed kidneys (100% sensitivity), while IVP identified the cause in 52 (74% sensitivity), which was a significant difference (p <0.05). CT and IVP excluded obstruction in all normal kidneys (100% specificity). A comparison between the isotope GFR of obstructed kidneys with the corresponding CT GFR showed a perfect correlation (r = 0.78, p <0.0001). Moreover, a similar comparison between isotope GFR and CT GFR of normal kidneys showed an excellent correlation (r = 0.73, p <0.0001). In obstructed and normal kidneys mean isotope clearance was not significantly different from that of mean CT clearance. Contrast enhanced spiral CT is more sensitive than IVP for identifying the cause of chronic obstructive uropathy. Moreover, it is as accurate as radioisotope renal scan for calculating the total and separate kidney function. We recommend spiral CT with contrast medium as a single radiological diagnostic modality for the assessment of patients with chronic renal obstruction and normal serum creatinine.

Renal nuclear medicine

The measurement of renal function has been a major field of interest in nuclear medicine. Many studies in the literature are still dedicated to this subject, with the aim of replacing the traditional urinary clearance methods with simpler and easier techniques. Simplified plasma clearance methods appear of sufficient accuracy to estimate global kidney function, except in very low function in which urinary clearance is still indicated. Gamma-camera methods have also been developed that, although of a lesser accuracy than the in vitro techniques, offer the important advantage of allowing renal imaging with the estimation of separate kidney function. Because of the intimate link between kidney function and structure, the diagnosis of nephrourological diseases has represented an important goal of nuclear medicine research. The functional information attainable with radionuclides is a valuable complement to the morphological information of imaging techniques such as x-ray computed tomography, ultrasonography, and magnetic resonance imaging. Recent contributions of nuclear medicine to the progress of clinical nephrology include the evaluation of renal function and the diagnostic work-up of renovascular hypertension, obstructive nephropathy, urinary tract infection, and renal transplantation.

Renal scintigraphy in insulin-dependent diabetes mellitus: Early glomerular and urologic dysfunction

Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by intravenous injection of 99mTc-diethylenetriaminepentaacetic acid (DTPA) and 131I-Hippuran in 115 insulin-dependent diabetic patients with albumin excretion rates (AER) <200 μg/min, and in 45 normal subjects. Separate kidney function and urinary elimination were estimated by renography. GFR was increased in the diabetic patients (152 ± 24 ml/min/1.73m 2, vs. 128 ± 15) and correlated significantly with RPF (r = 0.5; p < 10 −9). No relationship was found between GFR and the duration of diabetes, blood glucose, HbA 1c, or AER. Fifty patients were hyperfiltering with RPF and filtration fraction higher than those in the normofiltering group. Slow intrarenal or pyeloureteral elimination, either unilateral or bilateral, was observed in 3 controls and 60 diabetic subjects (24 hyperfiltering; 36 normofiltering) and did not disappear with the patient in the standing position. In these 60 patients, mean age, duration of diabetes, blood glucose, HbA 1c, 24 h albumin excretion rate, and frequency of peripheral or autonomic neuropathy did not differ from patients with normal scintigraphy; GFR was lower in the group with slow elimination, but not significantly so. 99mTc-DTPA renal uptake was symmetric in all the controls; asymmetric renal uptake with asymmetric GFR was observed in 13 patients (7 hyperfiltering; 6 normofiltering) and often associated with slower elimination. No evidence for renal stenotic atheroma or parenchymatous disease was found on the angiopyeloureterography. The results suggest that incipient uropathy is a very common phenomenon that occurs irrespective of glomerular dysfunction.

Congenital Renal Anomaly: Evaluation With 99mTc-Dimercaptosuccinic Acid Renal Scintigraphy

Technetium 99m-2,3, dimercaptosuccinic acid (99mTc-DMSA) preferentially accumulates in the renal cortex, demonstrating functioning cortical mass. We used 99mTc-DMSA renal scintigraphy in ten patients with horseshoe kidneys and five patients with unilateral fused kidneys. The results show that 99mTc-DMSA renal scintigraphy reliably establishes the diagnosis of horseshoe kidney and clearly shows the isthmus, which is very essential for proper management. The technique also aids in the definitive assessment of separate kidney function and of total radionuclide uptake is possible using 99mTc-DMSA scintigraphy.

Renal Function Studies using 99mTc-Dimercaptosuccinic Acid

99mTc-dimercaptosuccinic acid (DMSA), provides both a well defined renal image via preferential cortical accumulation, and a quantitative assessment of separate kidney function, correlating well with renal plasma flow obtained from the 131I-Hippuran renogram of each kidney. 99mTc-DMSA is capable of labeling the functioning nephrons in the cortex without interference by the activity of urine flow, suggesting that DMSA should be termed a cortical tubular marker. 99mTc-DMSA scintigraphy has advantages over conventional methods in that it can be performed repeatedly with little discomfort to the patients, as a routine clinical examination.

Separate renal function studies in conscious dogs with renovascular hypertension.

A new method was developed for separate kidney function studies by catheterizing the ureters and exteriorizing the catheters through the urethra into the vagina. Renal artery plication was performed to reduce blood flow to one kidney by 66 +/- 5%. Arterial pressure increased from 107 +/- 2 to 131 +/- 3 mmHg and remained elevated for 28 days. Plasma renin activity was increased for the first 7-10 days only. Sodium and water excretion were markedly reduced in the kidney with the stenosed renal artery and after the first 2 days Na and water excretion were incresed in the contralateral kidney. These changes in Na and water excretion were frequently associated with similar directional changes in glomerular filtration rate (GFR) and renal plasma flow. An exception was noted in that renal sodium and water excretion remained low throughout the 28 days in the kidney with the constricted renal artery, whereas GRF returned to near the control level by the end of 2 wk. Altered filtration fraction did not appear to be a determining factor in control of the rate of Na excretion. It is suggested that GFR, the renin-angiotensin-aldosterone system, and other as yet undefined factors are involved in salt and water homeostasis during unilateral renal artery stenosis with hypertension.

Validity of 99mTc Dimercaptosuccinic Acid Renal Uptake for an Assessment of Individual Kidney Function

99mTc dimercaptosuccinic acid is a new renal scanning agent that provides a good quality of renal image as a result of preferential cortical accumulation and also makes feasible a quantitative assessment of separate kidney function, correlating well with renal plasma flow obtained from a 131I hippuran renogram of each kidney. By measuring the dimercaptosuccinic acid uptake, the cortical functioning nephrons can be determined independent of the activity from the urinary outflow tract. Such evaluations may replace the conventional split renal function study in which traumatic procedures, such as cystoscopy and ureteral catheterizations, are required. 99mTc dimercaptosuccinic acid scintigraphy causes less discomfort to the patient and can be performed repeatedly and routinely even in children and debilitated geriatric patients.

A Scintillation Camera Technique for Quantitative Estimation of Separate Kidney Function and Its Use before Nephrectomy

A Scintillation Camera Technique for Quantitative Estimation of Separate Kidney Function and Its Use before Nephrectomy

A Scintillation Camera Technique for Quantitative Estimation of Separate Kidney Function and Its Use before Nephrectomy

A scintillation camera technique was used for measuring renal uptake of [131I]Hippuran 80-110 s after injection. Externally measured Hippuran uptake was markedly influenced by kidney depth, which was measured by lateral-view image after injection of [99mTc]iron ascorbic acid complex or [197Hg]chlormerodrine. When one kidney was nearer to the dorsal surface of the body than the other, it was necessary to correct the externally measured Hippuran uptake for kidney depth to obtain reliable information on the true partition of Hippuran between the two kidneys. In some patients the glomerular filtration rate (GFR) was measured before and after nephrectomy. Measured postoperative GFR was compared with preoperatively predicted GFR, which was calculated by multiplying the preoperative Hippuran uptake of the kidney to be left in situ, as a fraction of the preoperative Hippuran uptake of both kidneys, by the measured preoperative GFR. The measured postoperative GFR was usually moderately higher than the preoperatively predicted GFR. The difference could be explained by a postoperative compensatory increase in function of the remaining kidney. Thus, the present method offers a possibility of estimating separate kidney function without arterial or ureteric catheterization.

Sodium excretion in Goldblatt hypertension. Long-term separate kidney function studies in rats by means of a new technique.

Separate kidney function with special attention to sodium excretion was studied during 18 days in hypertensive rats with unilaterally constricted renal artery. For urine collection the bladder was divided into two separate chambers and drained by a new simple technique. Urinary flow rate of the untouched kidney was always elevated as compared to the clamped kidney. However the clearance of PAH and inulin of the untouched kidney was higher than that of the clamped kidney only during the first postoperative days and during saline intake. The osmolality and the inulin and potassium concentration were usually higher in the urine from the clamped kidney, whereas sodium concentration was higher in the urine from the contralateral kidney. Sodium excretion of the untouched kidney was not only greater than that of the clamped kidney but even greater than that of a normotensive control kidney. On the other hand sodium excretion of the clamped kidney was less than that of a normal kidney. Thus, total renal sodium output of the hypertensive and the normotensive rats did not differ. The reduced sodium excretion of the clamped kidney is interpreted as a consequence of the “exaggerated” sodium excretion of the untouched kidney, which is exposed to the high blood pressure.

THE USE OF THE I-131-HIPPURAN RENOGRAM IN THE DETECTION OF DISPARATE KIDNEY FUNCTION IN HYPERTENSIVE PATIENTS.

The reliability of the radioisotope renogram in detecting functional disparity in the separate kidneys of hypertensive patients with unilateral renal disease was investigated. Renograms recorded in 33 hypertensive patients without unilateral renal disease were employed for establishing control criteria. The physiologic basis for the three types of positive renograms found in the presence of unilateral renal dysfunction has been discussed. The renogram appears to be a valuable method for demonstrating significant disparity in separate kidney function while avoiding the hazards and technical difficulties of bilateral ureteral catheterization.

The effect of chlorothiazide on separate kidney function in essential hypertension

The effect of chlorothiazide on separate kidney function in essential hypertension

Simultaneous direct and indirect inulin clearance as a separate kidney function test.

Simultaneous direct and indirect inulin clearance as a separate kidney function test.