Quantifying Hemodialysis

Seasonal effects of dehydration in air on urea production in the frog Rana pipiens

Acetaminophen overdose may be accompanied by electrolyte disturbances. The basis for electrolyte change appears to be due to increased fractional urinary electrolyte excretion. This study investigated the impact of serum acetaminophen concentration on changes in serum potassium, creatinine and urea concentrations in patients with acetaminophen overdose. This was a retrospective cohort study which included patients admitted to the emergency department and hospital within 24 h of acetaminophen ingestion. The study was conducted over a period of 5 years from 1 January 2004 to 31 December 2008. Data are presented as mean ± SD and as medians (interquartile range) and groups were compared using independent two-tailed Student t-test. Statistical Package for Social Sciences (SPSS) 15 was used for data analysis. Two hundred and eighty-three patients were studied (44 males and 239 females), mean age 23 ± 7.5 years. Patients who had a serum acetaminophen concentration above a 'possible toxicity' treatment line were associated with an elevation in serum creatinine concentration (p=0.044) and a reduction in the serum potassium concentration (p<0.001) but were not associated with a reduction in serum urea concentration (p>0.99). During the study period, 63.3% (179 patients) had serum potassium concentrations less than the normal concentration (3.5 mmol/l) and 31.4% (89 patients) had serum urea concentrations less than the normal concentration (2.5 mmol/l). The serum creatinine concentration in all patients was within the normal range. Acetaminophen appears to cause a concentration-dependent reduction of potassium concentrations and an elevation of creatinine concentrations of short duration (<24 h) after overdose.

Renal AA amyloidosis in a dairy cow in Turkey

Spring‐summer frogs, Rana pipiens, acclimated at 22.5°C or 27°C were dehydrated in 0.15 M NaCl for up to 24 hours. After 10 or 24 hours of treatment, the concentration of urea in serum increases relative to the concentrations of urea measured in serum of frogs kept in tap water or 0.125 M NaCl. The increase in the concentration of urea in serum of spring‐summer frogs was associated with an increase in body urea and an increased rate of urea production. When fall‐winter frogs, acclimated at 20°C, were dehydrated in 0.15 M NaCl for 12.5 hours, no increase in the concentration of urea in serum was observed, relative to frogs treated with tap water or 0.125 M NaCl. After 48 hours, the concentration of urea in serum of frogs treated with 0.15 M or 0.125 M NaCl was the same, but both were significantly greater than tap water treated frogs. The metabolic basis for the increase in the rate of urea production observed in spring‐summer but not fall‐winter frogs in response to hyperosmotic sodium chloride is discussed.

Summary To evaluate the effects of compensated heart failure (hf) on digoxin pharmacokinetic properties in cats, 6 cats with dilated cardiomyopathy were compared with 6 clinically normal (control) cats. Digoxin tablets were administered at a dosage of 0.01 mg/kg of body weight, q 48 h for approximately 10 days, until presumed steady state was reached. Both groups were treated concomitantly with aspirin, furosemide, and a commercial low-salt diet. Retrospectively, control and hf cats were calculated to be at 95% and 97% steady state, respectively. At the time blood samples were collected, hf cats were clinically compensated. Serum digoxin concentration ([dxn]) was determined by radioimmunoassay on samples drawn immediately before and 1, 2, 4, 8, 12, 24, 34, and 48 hours after digoxin administration. Measured and calculated values (peak, 8-hour, and mean [dxn]; elimination half-life [t½]; oral clearance; and hours during which [dxn] was in the toxic range) were not significantly different between control and hf cats. To predict individual propensity for digoxin intoxication serum creatinine and urea concentrations and sulfobromophthalein dye retention were measured in control and hf cats prior to the onset of treatment with digoxin. There was no statistically significant correlation between serum creatinine and urea concentrations when compared with sulfobromophthalein dye retention nor between any of these values and digoxin peak, 8-hour, and mean concentrations or t½, oral clearance, or hours during which [dxn] was in the toxic range. Mean serum creatinine and urea nitrogen concentrations were significantly greater (P &lt; 0.01) and sulfobromophthalein dye retention approached significant prolongation (P &lt; 0.06) in hf cats, compared with that in control cats. All hf cats with sulfobromophthalein dye retention &gt; 5% at 30 minutes became digoxtn-intox-icated, on the basis of [dxn]; no hf cats with normal sulfobromophthalein dye retention became intoxicated. In compensated heart failure, digoxin pharmacokinetic properties are not altered beyond that expected when concurrent antithrombotic and offloading treatments with aspirin, furosemide, and commercial low-saltdiet are used. In addition, digoxin treatment q 48 h produces adequate serum concentrations in the cat, with steady state being reached after approximately 10 days of digoxin treatment in hf cats given concomitant treatment. Digoxin toxicosis can be expected in approximately 50% of animals given digoxin tablets at a dosage of 0.01 mg/kg, q 48 h, with the additional treatment described. Because of individual variation, [dxn] should be monitored to minimize digoxin toxicity and maximize its therapeutic efficacy. Blood samplings 8 hours after digoxin administration, after attaining approximate steady-state conditions in the animal, is recommended. Although serum urea and creatinine concentrations and sulfobromophthalein dye retention did not predict digoxin pharmacokinetic properties, the latter test may be useful in determining which cats will become digoxin-intoxicated.

This study is conducted to establish the profile of some serum biochemicals which included creatinine, urea, glucose, total protein and albumin concentrations in 104 clinically normal donkeys (65 males and 39 females) aged 2-4 years. Animals were classified on the basis of age and sex, in Baghdad city/ Iraq. The Results showed that the, mean values ± standard error (SE) of serum creatinine and urea concentrations were as follows: Creatinine 65.55±2.01 µmol/L and urea 6.79±0.20 mmol/L, while serum concentrations of glucose, total protein and albumin were 54.7±3.09 g/dl, 123±14.3 and 3.4±0.08 mmol/L, respectively. Creatinine values showed a significant difference between 4 years and more than 4 years old subgroups. However, there were no differences in serum urea concentration between male and female and compared with biochemical ranges obtaining for another donkey breeds. This suggested that most biochemical values determined in this study serve as reference ranges for Iraqi donkey and could be used in health control and diagnosis of diseases. In conclusion a significant increase in serum creatinine was recorded at age 4 and more than 4 years as compares with serum urea and no differences in serum glucose, total protein and albumin.

This study was designed to examine, the effect of Effective aqueous extract Lawsonia inermis leaves as antioxidant on concentration of Urea ,Criatinine and Histological of kidneys in Albino male Rats exposed to hydrogen peroxide induced oxidative stress. This study showed that 0.5% hydrogen peroxide concentration leds to significant increase (P&lt;0.05( in concentration of serum urea and creatinine comparing with control group. While the aqueous extract of Lawsonia inermis concentration (50mg/kg) led to significant decrease (P&lt;0.05) in concentration of serum urea and creatinine compare with control group. Also the results showed no significant increase in concentration of urea and creatinine in group exposed to oxidative stress and aqueous extract of Henna comparing with control group. The histological results of the kidney treated with (0.5%) H2o2 showed degeneration, congestion, lymphatic infilteration, vacuolation in the renal tubules with necrosis comparing with control. While sections of kidney treated with aqueous extract of Henna showed normal appearance of the renal tubules. Histological investigation of kidneys rats treated with H2O2 and extract of Henna showed improvement in histological picture with reduction in infilteration, vacuolation and necrosis but the tissue did not return back to the normal state.

Objectives To evaluate the influence of heart disease and heart failure on 9 parameters: the serum sodium, potassium, chloride, creatinine and urea concentrations, heart rate, vaso-vagal tonus index (VVTI), red cell number and hematocrit. Background Previous studies have demonstrated that heart disease, heart failure and their treatment are associated with changes in laboratory and electrocardiographic parameters. Animals, materials and methods Data were retrieved from 92 client-owned dogs with naturally occurring heart disease. Dogs were classified according to the severity of their heart disease and or the presence of heart failure. The effects of heart disease, the progression into heart failure, the initiation of successful therapy and the administration of diuretics on these parameters were determined. Results Worse heart failure was characterized by the following changes: a significant fall in serum sodium and chloride concentrations and VVTI, and a significant increase in the serum urea concentration and heart rate. The onset of heart failure was characterized by a fall in VVTI and chloride concentration. The successful treatment of heart failure was characterized by a fall in heart rate, an increase in creatinine and sodium concentrations. Dogs receiving diuretics had higher heart rates, lower VVTI, higher urea concentrations, lower potassium, sodium and chloride concentrations. Conclusions Numerous complex alterations in some of the studied parameters are associated with heart disease, heart failure and their treatment. Further consideration of these changes may improve our skills in diagnosis, prognostication and treatment.

Correlations among serum glucose, beta-hydroxybutyrate and urea concentrations in non-pregnant ewes

1. The effects of seasonal conditions and nutrition on serum proteins and serum urea concentrations were studied in female reindeer and reindeer calves in Finland. With the exception of one group in winter, the reindeer were roaming wild in the forests. This one group was kept in captivity, out of doors, on a comparatively high nutritional plane. One group lived wild during the winter in very poor nutritional conditions. 2. A very clear seasonal variation in the serum protein and urea concentration was found. The serum protein concentration was low in late winter and increased rapidly during the summer, being high in the autumn. The serum urea concentration was also low in the winter and high in the summer. In the autumn, however, the serum urea concentration was again low. 3. Changes in the serum protein concentration were normally associated with the serum globulins. Only in the very poor-nutrition group did the albumin content decrease significantly. As a result of the large changes in the concentration of serum globulins, there were also considerable changes in the albumin: globulin ratio. 4. The serum protein concentration was much lower in the reindeer calves than in the adult reindeer. The concentration of globulins in particular was much lower than in the adults.

The purpose of the present study was to examine the protective effect of FK453, (+)-(R)-1-[(E)-3-(2-phenylpyrazolo [1,5-a] pyridin-3-yl) acryloyl]-2-piperidine ethanol, a potent non-xanthine (adenosine A1 receptor antagonist, on glycerol-induced acute renal failure (ARF) in rat in comparison with the effects of FR113452 (S-(-) enantiomer of FK453), 1,3-dipropyl-8-cyclopentyl-xanthine (adenosine A1 receptor antagonist), theophylline (nonselective adenosine receptor antagonist), CGS15943 [1,2,4] triazolo [1,5-C] quinazolone, adenosine A2A receptor antagonist), and typical diuretics (hydrochlorothiazide and furosemide). FK453 (1 and 10 mg/kg orally) significantly reduced serum creatinine and urea concentrations in 25% glycerol (10 ml/kg intramuscularly)-induced ARF by protective treatment. The effect was similar to that of 1,3-dipropyl-8-cyclopentyl-xanthine and theophylline. FR113452 and CGS15943 had little effect on serum creatinine and urea concentrations. In contrast, hydrochlorothiazide and furosemide increased serum creatinine and urea concentrations. FK453, hydrochlorothiazide, and furosemide did not have any effect on either serum creatinine or urea concentration in 25% glycerol-induced ARF by therapeutic treatment. In 50% glycerol (10 ml/kg im)-induced ARF, FK453 reduced serum creatinine and urea concentrations, and increased urine volume and creatinine clearance. The results of the present study showed that FK453, a potent nonxanthine adenosine A1 receptor antagonist, ameliorated glycerol-induced ARF in the rat. The findings support the idea that adenosine is an important factor in the development of glycerol-induced ARF in the rat and that the protective effect of adenosine receptor antagonist is mediated via the adenosine A1 receptor. Drug Dev. Res. 39:47–53 © 1997 Wiley-Liss, Inc.

BackgroundAcute kidney injury (AKI) is frequent among critically ill patients. Renal replacement therapy (RRT) is often required to deal with severe complications of AKI. This technique is however associated with side effects such as hemodynamic instability and delayed renal recovery. In this study, we aimed to describe a novel model of hemodialysis in rats with AKI and depict a dialysis membrane performance.MethodsEighteen Sprague–Dawley rats received 0.75% adenine-rich diet to induce AKI. After 2 weeks, nine underwent an arterio-venous extracorporeal circulation (ECC) (ECC group) for 2 h without a dialysis membrane on the circuit and nine received a hemodialysis session (HD group) for 2 h with an ECC circuit. All rats were hemodynamically monitored, and glomerular filtration rate (GFR) was measured by transcutaneous fluorescence after the injection of FITC-Sinistrin. Blood samples were collected at different time points to assess serum creatinine and serum urea concentrations and to determine the Kt/V. Sinistrin concentration was also quantified in both plasma and dialysis effluent.ResultsAfter 2 weeks of adenine-rich diet, rats exhibited a decrease in GFR. Both serum urea and serum creatinine concentrations increased in the ECC group but remained stable in the HD group. We found no significant difference in serum creatinine and serum urea concentrations between groups. At the end of experiments, mean serum urea was 36.7 mmol/l (95%CI 19.7–46.9 mmol/l) and 23.6 mmol/l (95%CI 15.2–33.5 mmol/l) in the ECC and HD groups, respectively (p = 0.15), and mean serum creatinine concentration was 158.0 µmol/l (95%CI 108.1–191.9 µmol/l) and 114.0 µmol/l (95%CI 90.2–140.9 µmol/l) in the ECC and HD groups, respectively (p = 0.11). The Kt/V of the model was estimated at 0.23. Sinistrin quantity in the ultrafiltrate raised steadily during the dialysis session. After 2 h, the median quantity was 149.2 µg (95% CI 99.7–250.3 µg).ConclusionsThis hemodialysis model is an acceptable compromise between the requirement of hemodynamic tolerance which implies reducing extracorporeal blood volume (using a small dialyzer) and the demonstration that diffusion of molecules through the membrane is achieved.

BackgroundIn domestic animals many biochemical and physiological processes exhibit daily rhythmicity. The aim of the present study was to investigate the rhythmic pattern of salivary and serum urea concentrations in sheep.MethodsSix 3-year-old female sheep kept in the same environmental conditions were used. Sheep were sampled at 4 hour intervals for 48 consecutive hours starting at 08:00 of the first day and finishing at 04:00 of the second day. Blood samples were collected via intravenous cannulae inserted into the jugular vein; saliva samples were collected through a specific tube, the "Salivette". Salivary and serum urea concentrations were assayed by means of UV spectrophotometer. ANOVA was used to determine significant differences. The single Cosinor procedure was applied to the results showing significant differences over time.ResultsANOVA showed a significant effect of time on salivary and serum urea concentrations. Serum and salivary urea peaked during the light phase. In the dark phase serum and salivary urea concentrations decreased, and the diurnal trough occurred at midnight. Cosinor analysis showed diurnal acrophases for salivary and serum urea concentrations. Daily mean levels were significantly higher in the serum than in the saliva.ConclusionIn sheep both salivary and serum urea concentrations showed daily fluctuations. Urea is synthesized in the liver and its production is strongly influenced by food intake. Future investigation should clarify whether daily urea rhythms in sheep are endogenous or are simply the result of the temporal administration of food.

To determine whether patients with acute myocardial infarction undergoing thrombolysis with streptokinase develop changes in renal function. Prospective assessment of renal function in 60 consecutive patients admitted with acute myocardial infarction. Tertiary referral centre and city general hospital. 60 consecutive patients with acute myocardial infarction. Thirty eight were given streptokinase and 17 tissue plasminogen activator (alteplase) and five no thrombolytic agent (non-streptokinase group). Proteinuria and creatinine clearance on admission (day 1) and on days 3 and 6; serum urea and creatinine concentrations on days 1 and 7; streptokinase IgG on days 1, 2, and 7. Significant proteinuria (> 0.15 g/24 h) was found in 31 (82%) of the 38 patients in the streptokinase group (mean 0.47 g/24 h (95% confidence interval 0.35 to 0.6 g/24 h)) in the 24 hours after admission compared with six (27%) out of 22 in the non-streptokinase group (mean 0.17 g/24 h (0.12 to 0.2 g/24 h); P = 0.008). In the streptokinase group this decreased to the normal range by day 3 (mean 0.15 g/24 h (0.1 to 0.22 g/24 h); P = 0.0001 v baseline). Electrophoresis of urine showed the proteinuria to be glomerular in origin. Creatinine clearance and serum creatinine and urea concentrations were similar in both groups. In the streptokinase group detectable streptokinase IgG titres were found in 28 out of 32 (87%) patients. The median titre on admission was 16 (range 0-110); it fell to 3 (range 0-80; P = 0.001) by day 2 and increased to 61 (range 0-7700; P = 0.0002 v baseline) by day 7. Streptokinase was associated with significant early onset proteinuria of glomerular origin. This started to resolve by day 3 and resulted in no deterioration in overall renal function. The temporal relation to the initial fall in antibody titre suggests that it could be the result of immune complex deposition in the glomeruli.

Brown Swiss (BS) cows have greater urea concentrations in milk and blood compared with Holstein (HO) cows. We tested the hypothesis that BS and HO cows differ in kidney function and nitrogen excretion. Blood, saliva, urine, and feces were sampled in 31 multiparous BS and 46 HO cows kept under identical feeding and management conditions. Samples were collected at different lactational stages after the monthly DHIA control test-day. To test the glomerular filtration rate (GFR) and urea excretion, concentrations of creatinine and urea were measured in serum, urine, and saliva. As an additional marker to estimate GFR, we determined symmetric dimethylarginine (SDMA) in serum. Feces were analyzed for dry matter content and nitrogen concentration. Data on milk urea and protein concentrations, and daily milk yield were obtained from the monthly DHIA test-day records. The effects of breed, time, and parity number on blood, saliva, urine, feces, and milk parameters were evaluated with the GLM procedure with breed, time, and parity number as fixed effects. Differences between BS and HO were assessed by the Tukey-corrected t-test at P < 0.05. Concentrations of urea, creatinine, and SDMA in serum, were greater in BS than in HO cows (P < 0.01): 5.46 ± 0.19 vs 4.72 ± 0.13 mmol/L (urea), 105.96 ± 2.23 vs 93.07 ± 1.50 mmol/l (creatinine), and 16.78 ± 0.69 vs 13.39 ± 0.44 µg/dL (SDMA). We observed a greater urea concentration in BS cows (25.8 ± 0.7 vs 21.8 ± 0.7 mg/dL) and protein content in milk (3.70 ± 0.08 vs 3.45 ± 0.07%) than in HO cows (P < 0.01). Urea and creatinine concentrations in urine and saliva did not differ among breeds. No differences between BS and HO were observed for milk yield, fecal DM, and fecal nitrogen content. Dry matter intake and body weight were similar in BS and HO cows (P > 0.05). Despite greater urea, creatinine, and SDMA concentrations in blood as well as a higher milk urea content in BS compared with HO, respective concentrations in urine did not differ between breeds. In conclusion, our results demonstrate a lower renal GFR in BS compared with HO cows, thereby contributing to the greater plasma urea concentration in BS cows. However, estimation of nitrogen excretion via milk, urine, and feces does not entirely reflect nitrogen turnover within the animal.