A human inhibitor of tumor necrosis factor alpha.

Urine of some febrile patients exhibits a TNF-alpha inhibitory activity (TNF-alpha INH), sensitive to heat and trypsin, with an apparent mol wt of 40-60 X 10(3) and a pI range of 5.5-6.1. As for the Il-1 INH, the TNF INH activity involves a competitive mechanism of action suggesting the existence of a family of negative feedback-regulating molecules interfering with cytokines actions.

Morphometric analysis of the translocation of lumenal membrane between cytoplasm and cell surface of transitional epithelial cells during the expansion-contraction cycles of mammalian urinary bladder.

The flow of membrane between the cytoplasm and the lumenal surface during the expansion-contraction cycle of urinary bladder was estimated by stereological examination of electron micrographs of urothelial cells from guinea pigs, gerbils, hamsters, rabbits, and rats. The quantitative data obtained allowed an approximation of the surface area, volume, and numbers of lumenal membranelike vesicles and infoldings per unit volume of cytoplasm. Depending upon the species, approximately 85 to approximately 94% of the membrane surface area translocated into and out of the cytoplasm was in the form of discoidal vesicles. The remainder was accounted for by infoldings of the lumenal plasma membrane. The density of vesicles involved in transfer of membrane was quite similar in all the species examined, except guinea pigs which yielded lower values. In contrast, the densities of the total cytoplasmic pools of discoidal vesicles potentially available for translocation varied greatly among the different species. In general, species of animals with a highly concentrated urine had a greater density of discoidal vesicles than species with a less concentrated urine. This correlation may indicate an authentic relationship between lumenal membranes and the tonicity of urine, such as increased membrane recycling or turnover with increasingly hypertonic urine; or it may signify the existence of some other, more obscure relationship.

Social rank in house mice: differentiation revealed by ultraviolet visualization of urinary marking patterns.

Ultraviolet light has been used to examine urine marks deposited by adult male house mice on filter paper on the floors of their cages during overnight tests. Both the urination frequency and the pattern in which urine was deposited on the filter paper depended upon social rank. Dominant males vigorously marked their entire cage floor, whereas subordinate males typically voided urine in only two to four pools in the corners of their cages.

Physicochemical basis for formation of renal stones of calcium phosphate origin: calculation of the degree of saturation of urine with respect to brushite.

Brushite (CaHPO(4).2H(2)O) was considered to govern the formation of renal calculus of calcium phosphate origin. The degree of saturation of urine with respect to this phase was therefore calculated. This value was obtained from the ratio of the activity product of Ca(++) and HPO(4) (m) (K(sp)) before and after incubation of urine with brushite. The errors in the calculation of K(sp) were largely eliminated by this procedure.The urine of patients with idiopathic hypercalciuria and recurrent calcium-containing renal calculi was supersaturated with respect to brushit largely because of the high urinary concentration of Ca(++). The urine of normocalciuric subjects was undersaturated except at high urinary pH. This technique of estimating the degree of saturation of urine should allow a quantitative assessment of the various therapeutic regimens recommended for patients with nephrolithiasis.

An inhibitor of sodium transport in the urine of dogs with normal renal function.

The urine and serum of chronically uremic patients and dogs contain an inhibitor of sodium transport that reduces short-circuit current (SCC) in the toad bladder and produces natriuresis in the rat. The present studies represent an effort to determine whether the same inhibitor is detectable in urine of normal dogs maintained on a dosium intake varying from 3 to 258 meq/day. Observations were made with and without fludrocortisone. The same Sephadex G-25 gel filtration fraction previously shown to contain the "uremic" inhibitor was tested in both the isolated toad bladder and rat bioassay systems. The fraction from dogs maintained on 258 meq qodium plus 0.2 mg fludrocortisone/day consistently inhibited SCC in the toad bladder and induced a natriuresis in the rat (P less than 0.001). The fraction from dogs on the same sodium intake without fludrocortisone was also natriuretic (P less than 0.01) but did not inhibit SCC significantly. In contrast, the fraction from dogs fed 3 meq sodium with fludrocortisone or 91 meq sodium without fludrocortisone had no significant effect in either assay system. Thus, an inhibitor of sodium transport has been found in the urine of nonuremic dogs. Both the degree of natriuresis in the rat and the degree of inhibition of SCC in the toad bladder correlated with the state of sodium balance which ensued in the dog.

Warfarin metabolism in man: identification of metabolites in urine.

After administration of the coumarin anticoagulant racemic warfarin to normal humans, seven fluorescent compounds were chromatographically separated from extracts of their urine. Four of these were identified using mass spectrometry, thin-layer chromatography, and ultraviolet absorption spectroscopy. One metabolic pathway, reduction of the acetonyl side chain of warfarin, resulted in the formation of a second asymmetric carbon atom, and two diastereoisomer alcohols were identified. These warfarin alcohols are structurally similar to pharmacologically active coumarin derivatives. They have not been reported in animal studies. In addition, 6- and 7-hydroxywarfarin were identified. These are the first studies to document the metabolic fate of warfarin in the normal human.

Development and clinical application of a new method for the radioimmunoassay of arginine vasopressin in human plasma.

A radioimmunoassay has been developed that permits reliable measurements of plasma arginine vasopressin (AVP) at concentrations as low as 0.5 pg/ml in sample volumes of 1 ml or less. Nonhormonal immunoreactivity associated with the plasma proteins is eliminated by acetone precipitation before assay, leaving unaltered a component that is immunologically and chromatographically indistinguishable from standard AVP. Storage of plasma results in a decline in AVP concentration and, thus, must be carefully regulated. The plasma AVP values obtained by our method approximate the anticipated levels and vary in accordance with physiologic expections. In recumbent normal subjects, plasma AVP ranged from (mean +/-SD) 5.4+/-3.4 pg/ml after fluid deprivation to 1.4+/-0.8 pg/ml after water loading, and correlated significantly with both plasma osmolality (r=0.52; P<0.001) and urine osmolality (r=0.77; P<0.001). After fluid restriction, plasma AVP was uniformly normal relative to plasma osmolality in patients with nephrogenic diabetes insipidus and primary polydipsia but was distinctly subnormal in all patients with pituitary diabetes insipidus. The infusion of physiologic amounts of posterior pituitary extract caused a dose-related rise in plasma vasopressin that afterwards declined at the expected rate (t(1/2)=22.5+/-4 min). We conclude that, when used appropriately, our radioimmunoassay method provides a useful way of assessing AVP function in man.

An evaluation of fetal renal function in a chronic sheep preparation.

Fetal renal function in the sheep was investigated in a chronic preparation which permitted repeated evaluations of urine flow and osmolality as well as renal clearances in animals which were unanesthetized and remote from acute surgical stress. Measurements of fetal blood pressure, pH, osmolality, fetal growth in utero, and final outcome did not indicate an adverse effect of the experimental procedure on the fetus. Fetal urine flow and osmolality were highly variable during the early postoperative period. They did not stabilize until 3-6 days after surgery, when urine osmolality became markedly hypotonic (range 65-160 mOsm/kg H(2)O) and urine flow rose to approximately 0.14 ml/min.kg. Fluctuations in urine flow and osmolality in the early postoperative period were the result of tubular reabsorption of water rather than a change in the glomerular filtration rate. The inulin-(14)C clearance, used as a measure of the glomerular filtration rate, was 1.05 +/-0.05 ml/min.kg (mean +/-sem) for all animals studied. Urea, fructose, sodium, and chloride were partially reabsorbed by the fetal kidney, while creatinine was secreted. Continuous drainage of fetal urine for 18 days in one animal demonstrated that the fetus was able to excrete large amounts of water, sodium, and fructose without apparent detrimental effects.

Direct measurement of osteolysis in man.

Precise, direct measurement of bone calcium release (v(o-)) has been accomplished using a continuous tracer administration (CTA) technique. Dietary calcium (96.97% (40)Ca) is replaced by (40)Ca (99.991% (40)Ca) and blood levels of the naturally occuring isotope (48)Ca are monitored by neutron activation analysis as a function of time. (48)Ca abundance falls as this isotope is excreted and only partially replaced by release from bone. After a suitable period, an asymptotic abundance of (48)Ca in serum, E, is approached which is the fraction of the turnover rate of the rapidly exchangeable calcium pools coming from the skeleton (E = v(o-)/v(t)). E is determined with a standard error of 2%, providing a precise, sensitive index of v(o-). 13 studies in three normal men and one postmenopausal woman receiving maintenance estrogen show large intersubject variations in parameters of calcium metabolism using both CTA and pulse tracer administration (PTA) plus balance techniques. Induced hypercalcemia results in a prolonged decrease in v(o-). Glucocorticoid therapy initially and consistently induces a marked hypercalciuria while effects on most other parameters of calcium kinetics are variable. In two men E fell when testosterone was added to glucocorticoid treatment, consistent with the known antiosteolytic effect of androgens, despite the short period of study.

Antibacterial activity of human urine.

The fate of bacteria in human urine was studied after inoculation of small numbers of Escherichia coli and other bacterial strains commonly implicated in urinary tract infection. Urine from normal individuals was often inhibitory and sometimes bactericidal for growth of these organisms. Antibacterial activity of urine was not related to lack of nutrient material as addition of broth did not decrease inhibitory activity. Antibacterial activity was correlated with osmolality, urea concentration and ammonium concentration, but not with organic acid, sodium, or potassium concentration. Between a pH range of 5.0-6.5 antibacterial activity of urine was greater at lower pH. Ultrafiltration and column chromatography to remove protein did not decrease antibacterial activity. Urea concentration was a more important determinant of antibacterial activity than osmolality or ammonium concentration. Increasing the urea of a noninhibitory urine to equal that of an inhibitory urine made the urine inhibitory. However, increasing osmolality (with sodium chloride) or increasing ammonium to equal the osmolality or ammonium of an inhibitory urine did not increase antibacterial activity. Similarly, dialysis to decrease osmolality or ammonium but preserve urea did not decrease inhibitory activity. Decreasing urea with preservation of ammonium and osmolality decreased antibacterial activity. Removal of ammonium with an ion exchanger did not decrease antibacterial activity, whereas conversion of urea to ammonium with urease and subsequent removal of the ammonium decreased antibacterial activity. Urine collected from volunteers after ingestion of urea demonstrated a marked increase in antibacterial activity, as compared with urine collected before ingestion of urea.

Genes that modify expression of major urinary proteins in mice.

A survey of major urinary proteins (MUPs) from eight BALB/c mouse substrains by isoelectric focusing identified a common pattern with about 10 protein bands in males. One substrain, BALB/cJPt, differed in that it expressed two variant MUP patterns, designated 4.1lo and null. To find the chromosomal location of the gene which determines the 4.1lo phenotype, BALB/cJPt-MUP-4.1lo was crossed with a wild-derived Mus musculus domesticus inbred strain (CLA) that expresses the common BALB/c MUP pattern. The F1 phenotype revealed that the gene(s) controlling the MUP-4.1lo trait was recessive. A restriction fragment polymorphism between these strains found with a MUP cDNA probe allowed us to establish that a gene determining the MUP-4.1lo trait was not linked to the MUP structural genes on chromosome 4. Assays for other chromosomal marker loci revealed that a gene determining the MUP-4.1lo trait, designated Mupm-1, was closely linked to Myc-1 on chromosome 15. To determine the genetic basis of the null trait, BALB/cJPt-MUP-null mice were crossed with BALB/cJPt-MUP-4.1lo mice. A MUP restriction fragment polymorphism between these two lines was tightly linked to a gene or genes involved in determining the MUP-null phenotype. The two variant MUP phenotypes in BALB/cJ mice are determined by separate genes, one of which is located on chromosome 4 and the other on chromosome 15. The chromosomal location of Mupm-1 suggests that it produces a trans-acting factor which regulates MUP expression.

Bioassay procedure for the detection of mutagenic metabolites in human urine with the use of sister chromatid exchange analysis.

A short-term bioassay system for the detection of activated mutagenic metabolites in urine from humans exposed to promutagens was described. Human diploid fibroblasts were grown in medium containing 5--20% urine from smokers, from nonsmokers, and from individuals undergoing cyclophosphamide (Cp) chemotherapy for treatment of cancer. The cells were then subjected to sister chromatid exchange (SCE) analysis. Activated Cp metabolic products in urine specimens produced up to a ten-fold increase in SCE's over preinjection SCE levels for the same individuals. Linear dose-response curves over a urine concentration range from 5 to 20% in culture medium were obtained from cells grown in urine specimens from 7 nonsmokers and 8 cigarette smokers. This test system proved to be sensitive to ambient exposure levels of environmental mutagens and demonstrated that urine from smokers was significantly more mutagenic than was urine from nonsmokers. Replicate experiments showed highly reproducible SCE values for each individual as well as for average SCE values for each group of subjects. The ability of this bioassay system to detect trace mutagenic activity in human urine reproducibly makes it an attractive choice for the monitoring of humans who have been exposed to environmental and/or industrial mutagens.

Comparative validity of random-interval and fixed-interval urinalysis schedules.

Accurate detection of unprescribed drug use by addicts in treatment may facilitate their rehabilitation. Many clinics collect urine samples at random, using fixed-interval collection schedules, which are not free from sampling error. Random-interval schedules minimize sampling error and consequently increase detectability of drug use by eliminating safe periods during which drug use cannot be detected. We compared these two methods by observing rates of detected opiate- and quinine-positive samples preceding and following implementation of random-interval schedules. Detected drug use doubled initially. As detection and clinical sanctions became more certain, drug use declined to well below its former level. Programs that use fixed-interval schedules may underdetect drug use by more than 50%. If patients can reliably predict safe periods, the possibility of using drugs without fear of detection may impede their rehabilitation.

The value of preoperative screening investigations in otherwise healthy individuals.

To assess the value of routine screening preoperative investigations in an otherwise healthy surgical population, the charts of 2570 patients undergoing cholecystectomy in two university teaching hospitals were reviewed. Of these, 1010 patients who were believed to be free of active disease other than cholelithiasis were selected for further study. Preoperative screening investigations were assessed in terms of frequency of use and abnormalities detected. The predictive values of these tests were analyzed and compared with information obtained from the history and physical examination. The frequency with which action was taken because of abnormal test results was also determined. Of the 5003 preoperative screening tests performed, abnormal results were obtained in 225. Of these, 104 were of potential importance. Action resulting from these abnormalities occurred in 17 cases. In only four patients could a conceivable benefit have arisen from a preoperative screening test. When compared with the results of the history and physical examination, routine preoperative investigations provided little further information that altered management in otherwise healthy surgical patients undergoing cholecystectomy.

Changing physician test ordering in a university hospital. An intervention of physician participation, explicit criteria, and feedback.

To decrease inappropriate test ordering by medical house staff in a university hospital, we examined the feasibility of an intervention that involved physicians in developing explicit criteria for ordering four specific tests and incorporated feedback of tests ordered. We implemented a time series design with measures at 12 and six months before, during, and three weeks after the intervention. During the intervention, orders for initial or admission chest roentgenograms decreased by 22% and repeated orders for routine urinalyses, chest roentgenograms, and leukocyte differential counts decreased by 23%, 30%, and 46%, respectively, compared with the six-month preintervention period. Orders for prothrombin time and/or partial thromboplastin time did not fall. After the intervention, most test ordering remained at the intervention level. These preliminary results suggest that this intervention may be effective and not overly costly.

The unproven utility of preoperative urinalysis. Clinical use.

We investigated the utility, ie, relevance to clinical outcome, of routine preoperative urinalysis with a retrospective study of 200 clean-wound, orthopedic, nonprosthetic knee procedures. Physicians primarily order a preoperative urinalysis to detect infection, because of the purported relationship between remote infection and surgical wound infection. We found that preoperative urinalysis is uniformly ordered, with a high prevalence of abnormal results (15%) but a low physician-response rate (29%). Wound infection was rare, but there was no difference in frequency of wound infection between patients with normal and abnormal results of urinalysis. We conclude that the utility of routine preoperative urinalysis is unproven. Current practice does not agree with the rationale for ordering this test, nor does published literature support it. Although data are inadequate to fully define the appropriate use of preoperative urinalysis, we suggest clinical recommendations and avenues for further research.

Vasopressin-resistant nephrogenic diabetes insipidus. A result of amphotericin B therapy.

Polyuria and polydipsia developed in two cases during amphotericin B therapy for deep mycoses. Neither patient could concentrate his urine in response to water deprivation or exogenous vasopressin. Other causes of vasopressin-resistant nephrogenic diabetes insipidus were not present. Three months after amphotericin B therapy had been discontinued, concentrating ability improved toward normal. A third patient was further observed and demonstrated normal diluting capacity but impaired free-water reabsorption, suggesting a distal tubular defect consistent with nephrogenic diabetes insipidus. Four months after discontinuing therapy, renal concentrating ability was normal. Amphotericin B can induce a reversible form of nephrogenic diabetes insipidus.

Ineffectiveness of intravenous ascorbic acid as an acidifying agent in man.

The acidifying effect of intravenous (IV) ascorbic acid was studied in seven healthy adult volunteers. After obtaining baseline urine and blood samples, 2-g IV doses of ascorbic acid were administered to each subject during a 20-minute period. Venous blood samples were obtained at times 0.5, 1, and 2 hours, and urine was collected at times 0.5, 1, 2, and 3 hours. Our results show that venous blood pH, plasma bicarbonate concentration, urine PCO2, and urine bicarbonate excretion did not change significantly during the study period. Urinary titratable acidity, ammonium excretion, and net hydrogen ion excretion decreased, and urinary pH actually showed a significant rise at two hours. We therefore conclude that IV ascorbic acid administered in recommended doses does not effectively acidify urine.

Noneffect of isoniazid on urine glucose tests.

Isoniazid has been shown by in vitro study to reduce Clinitest tablets. The effect of isoniazid on urine glucose tests was investigated in 30 patients by comparing commonly used glucose oxidase methods to Clinitest. Study results indicate that isoniazid does not cause clinically significant interference with the copper reduction method for urine glucose determination.

Understanding diabetes routines: a professional training exercise.

As part of the continuing education programs conducted at the Washington University Diabetes Research and Training Center, 65 health professionals participated in a 4-day simulation exercise which required them to adhere to a diabetic regimen. Instructions covered injections, urine testing, recording results, and calculating and following a meal plan. Evaluation of the simulation focused on the degree of participant adherence to each component, the problems they encountered, and how the experience influenced their patient/clinician interaction. Mean scores for adherence over the 4-day period for each component of the regimen were injections (82%), diet (67%), urine testing (58%), and recording results (56%). Of the total number of adherence problems encountered by the participants, 52% were diet-related, 17% involved urine testing, 17% time constraints, 10% loss of spontaneity, and 4% involved injections. Analysis of the impact of the experience in the work setting indicated improved participant sensitivity to diabetic patient adherence problems and increased ability to effectively counsel patients and family members.