J.U. Schlegel

Individual renal plasma flow determination in 2 minutes

A method is described for determining effective renal plasma flow, using the renal counts 1 to 2 minutes after injection and applying background subtraction as a ratio to the total amount of radio-activity injected intravenously with appropriate correction for kidney depth. It appears that this simple approach for determination of effective renal plasma flow within a matter of 2 minutes is accurate and reliable, and should be useful for a number of applications when it is important to determine total and individual renal plasma flow. The approach is recommended as a screening procedure in lieu of the determination of blood urea nitrogen and serum creatinine, with the additional advantages of gross morphology and determination of individual renal plasma flow in an absolute as well as relative manner.

Heterotransplantation of the Kidney: Two Clinical Experiences

The field of heterotransplantation is now being explored because of success with immunosuppressive measures in homotransplantation, and because of the scarcity of suitable human organs. Two patients in terminal uremia, maintained on dialysis, received heterotransplants from nonhuman primates. In the first case a renal heterotransplant from a rhesus monkey implanted in a 32-year old woman showed satisfactory immediate function but was removed after 10 days because of inadequate function. The second patient received a renal hetero transplant from a chimpanzee. A threatened rejection was reversed with immunosuppressive measures, but 2 months after transplantation the patient died of pneumonia. The transplanted kidneys showed no evidence of rejection.

Determination of Filtration Fraction Using the Gamma Scintillation Camera

A simple technique for determining effective renal plasma flow, filtration fraction and filtration rate is described. The determination depends upon the use of 131iodine labeled hippuran and 99mtechnetium labeled iron ascorbate or Sn diethylenetriaminepentaacetic acid. The filtration fraction is determined by dividing the corrected uptake for the technetium compound by the corrected uptake for radiohippuran. The uptake is simply determined by the 1 to 2-minute count over the kidneys with background subtraction and taking into account the amount injected. The technique is simple, quick and appears to be a useful clinical tool.

Inhibitory Effect of L-Ascorbate on Tumor Formation in Urinary Bladders Implanted with 3-Hydroxyanthranilic Acid

Summary A 2 × 2 factorial experiment was done to test the interaction of ascorbic acid and 3-hydroxyanthranilic acid on the development of malignant and total tumors in the urinary bladders of mice. An analysis of the data showed that the probability of survival was the same in all groups of mice and that ascorbic acid inhibited the anticipated carcinogenic effect of 3-hydroxyanthranilic acid.

Vasectomy in rhesus monkeys I. Surgical techniques and gross observations

Vasectomy and vaso-occlusion techniques were used in 47 male rhesus monkeys to maximize and minimize the amount of sperm allowed to escape from the vas into surrounding tissues for up to seventy-two weeks postoperatively. Body weight changes and blood clinical data indicated that the general health of all the monkeys remained good. Normal seasonal changes in body weights and testicular volumes suggested that there were no disturbances to the endocrine system and that the monkeys remained responsive to seasonal environmental stimuli. Vasectomy appears to cause no short-term deleterious effects in the rhesus monkeys, based on observations made during the seventy-two weeks that these monkeys were study after vasectomy. This conclusion agrees with the findings of other investigators.

Nitrofurantoin, Sulfamethizole and Cephalexin Urinary Concentration in Unequally Functioning Pyelonephritic Kidneys

Nitrofurantoin, sulfamethizole and cephalexin peak urinary drug concentrations were studied in patients and non-human primates with unequally functioning pyelonephritic kidneys. The peak urinary drug concentration of the poorly functioning kidney in comparison to the better kidney was greater than its percentage relative blood flow or creatinine clearance but variable in its relationship to creatinine concentration, osmolality and sodium concentration. Although for each unit of creatinine clearance the poorly functioning kidney had a higher peak urinary drug concentration than the better functioning kidney, for each kidney the peak urinary drug concentration seemed to be directly proportional to the creatinine clearance, the drug dosage and the renal mechanisms of drug excretion. Nitrofurantoin in the usual recommended dosage did not reach minimal inhibitory urinary drug concentration below a unilateral creatinine clearance of 20 ml. per minute. Whereas, sulfamethizole and cephalexin reached peak urinary drug concentrations greater than the minimal inhibitory concentration at the lowest studied unilateral creatinine clearance of 4 and 11 ml. per minute, respectively.

Vasectomy in rhesus monkeys II. Failure to demonstrate humoral and cellular immune responses specific for sperm

Abstract A study designed to determine whether humoral antibodies and a cell-mediated immune response to sperm antigen(s) in rhesus monkeys after unilateral and bilateral vas ligations has revealed negative findings. Kibrick agglutination, indirect hemagglutination, and sperm immobilization tests on pre- and postvasectomy sera obtained at timed intervals of one to one hundred and two weeks indicated that significant sperm agglutinating, hemagglutinating, and immobilizing antibodies did not develop in these animals. Also, lymphocyte transformation studies showed that a significant cellular antibody response to sperm antigen(s) did not develop in vasectomized animals. Furthermore, sera from rhesus monkeys injected with autologous and homologous washed sperm in Freunds adjuvant failed to demonstrate a positive reaction in agglutination and immobilization tests. On the other hand, immunization of a female rhesus monkey with washed sperm in Freunds adjuvant produced high titer sperm agglutinating and immobilizing antibodies. Therefore, it has not been possible to repeat or contribute supporting data to literature reports concerning the presence of antibodies to sperm in vasectomized rhesus monkeys. It is further suggested that a number of antigens unrelated to sperm might react with sera obtained from vasectomized animals and lead to positive findings in sperm agglutination and immobilization tests. As a result, erroneous conclusions may be drawn about the development of antibodies specific for sperm in vasectomized rhesus monkeys. Definitive conclusions concerning the development of specific antibodies to sperm antigens after vasectomy will be possible only when sperm antigens have been isolated, purified, and chemically and immunologically characterized for use in serologic tests.

Stabilization of Urinary 3-Hydroxyanthranilic Acid by Oral Administration of L-Ascorbic Acid.

Summary A method is presented for the stabilization of urinary 3-hydroxyanthranilic acid (3-HOA) to enable the acquisition of more reliable data concerning the urinary excretion of 3-HOA by patients with tumors of the urinary bladder. The data show that significant amounts of 3-HOA can decompose in urine samples of some tumor patients if such samples are allowed to incubate at 37°C for 6 hours, and that the presence of high levels of L-ascorbate in such samples inhibits this decomposition.

Decomposition of 3-hydroxyanthranilic acid under simulated physiologic conditions.

Summary The stability of 3-hydroxyanthranilic acid (3-HOA) in buffer solutions was investigated as it relates to pH, oxygen tension, and catalytic ion concentrations. The data show that 3-HOA is unstable under certain simulated physiologic conditions, and suggest that the amounts found in some samples of voided urine are not necessarily the true quantities formed, but rather may be the amounts remaining after decomposition of the metabolite in the interim between formation and analysis.

Vasectomy in rhesus monkeys III. Light microscopic studies of testicular morphology

Rhesus monkeys were randomly assigned to undergo various surgical procedures. The animals were followed from one to sixty-six weeks postvasectomy, at which time they were sacrificed and their tissues prepared for light and electron microscopy. Vasectomy in the rhesus monkey, as in certain other species, appears to be a procedure not attended with widespread testicular atrophy or histologic evidence of impaired spermatogenic potential utilizing the procedures and postoperative periods studied. Why certain animals exhibited focal degenerative changes is unclear; perhaps a certain population, yet to be defined, is more sensitive to such procedures, resulting in testicular alterations. It is important that such a population and such changes be defined to predict more accurately the possibility of successful vasovasostomy and reestablishment of fertility.