The 2006 National Kidney Foundation K/DOQI guidelines have lowered the peritoneal dialysis adequacy standard of Kt/V(urea) from 2.1 to 1.7 in anuric patients, largely based on the patient survival results of 2 clinical trials in Mexico and Hong Kong. It is our contention that the guidelines may be misleading since they have chosen to ignore the bias in these trials and have ignored the adverse outcomes in control groups in the trials on which the guidelines are based, as well as the body size of the subjects in these trials. Body size has changed in the US and Canada over the last few decades and there are similar changes worldwide. We suggest that the minimum targets for peritoneal dialysis be reinstituted at the previous standard Kt/V(urea) of 2.0.
The experiments were conducted on bulls-analogs of the black-piebald and Simmental breed which differ from each other in the intensity of live weight gain (18-31%) as well as on lactating cows-analogs of the black-piebald breed which differ in the level of milk productivity (41-80%). The intensity of the carboxylation processes (CO2 fixation) as well as of protein and lipids biosynthesis in the liver of the bulls from a heavy-producing group (the second group) is shown to be considerably higher than in the low-producing animals (the first group). In venous blood plasm of the second group bulls the content of urea and citrate was higher (by 29-141 and 33%, respectively) than in the first group animals. Blood plasma of the lactating cows from a heavy-producing group contains more urea (57-70%), citrate (146-80%) and total protein (10-14%) than that of animals with low milk productivity. Similar regularity is also observed as to the amount of urea and citrate of milk of cows with a higher milk productivity (by 40-50 and 51-53% higher respectively, than in the low-productive animals).
We have studied 126 chemical compounds. Moreover 9-triphenylphosphoniomethyl-phenanthrene chloride has been found to stabilize bioassays and preserve their urea content unchanged for a period of 90-990 days. Due to its use a delayed technique of a quantitative assessment of urea in biological objects has been elaborated characterized by universal novelty. It may be used with the aim of studying metabolic processes in the cosmonauts' body, atomic submarine crews, members of polar, alpine, desert, underwater, space and other expeditions which cannot be accompanied by a biochemical laboratory.
Arctic Investigations Program, Division of Preparedness and Emerging Infections, National Center for Emerging Zoonoses and Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK 99508, United States. email@example.com
To evaluate the accuracy of two non-invasive tests in a population of Alaska Native persons. High rates of Helicobacter pylori (H. pylori) infection, H. pylori treatment failure, and gastric cancer in this population necessitate documentation of infection status at multiple time points over a patient's life.
In 280 patients undergoing endoscopy, H. pylori was diagnosed by culture, histology, rapid urease test, (13)C urea breath test (UBT), and immunoglobulin G antibodies to H. pylori in serum. The performances of (13)C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori test by culture or, in case of a negative culture result, by positive histology and a positive rapid urease test.
The sensitivity and specificity of the (13)C-UBT were 93% and 88%, respectively, relative to the gold standard. The antibody test had an equivalent sensitivity of 93% with a reduced specificity of 68%. The false positive results for the antibody test were associated with previous treatment for an H. pylori infection [relative risk (RR) = 2.8]. High levels of antibodies to H. pylori were associated with chronic gastritis and male gender, while high scores in the (13)C-UBT test were associated with older age and with the H. pylori bacteria load on histological examination (RR = 4.4).
The (13)C-UBT outperformed the antibody test for H. pylori and could be used when a non-invasive test is clinically necessary to document treatment outcome or when monitoring for reinfection.
Cites: J Infect Dis. 2009 Mar 1;199(5):652-6019125674
Cites: Can J Gastroenterol. 2006 Dec;20(12):775-817171196
The anabolic effects of insulin-like growth factor-I (IGF-I) may involve a decrease of hepatic nitrogen (N) clearance, but this has never been studied in humans. Patients with cirrhosis have low levels of IGF-I and might benefit from IGF-I therapy. Conversely, a possible decrease in hepatic N clearance by IGF-I could increase the risk of hepatic encephalopathy.
To examine the effects of 1-week IGF-I administration on the functional hepatic N clearance (FHNC), viz. the linear slope of the relationship between blood-a-amino-N concentration and urea-N synthesis rate as controlled by an infusion of alanine.
A randomized sequence-crossover placebo-controlled study. Eight healthy volunteers and eight patients with alcoholic cirrhosis received injections of saline or IGF-I twice daily (50 µg/kg) for 7 days.
IGF-I levels at baseline were lower in the patients than those in the controls. The IGF-I treatment normalized patient levels and caused an increase in the controls to supra-physiological levels. FHNC was lower in patients compared with healthy subjects (23.0 vs 36.5 L/h, P=0.03). IGF-I treatment reduced FHNC by 30% in healthy subjects (from 36.5 to 25.7 L/h, P = 0.02), whereas no effect was found in the patients.
IGF-I downregulates urea synthesis in normal subjects. This may be part of the explanation behind the anabolic effects of IGF-I. The normalization of IGF-I in cirrhosis patients without an effect on urea synthesis implies that the patients were resistant to IGF-I with regard to reduction of hepatic amino-N elimination. IGF-I treatment of cirrhosis patients evidently carries no risk of N accumulation.
To estimate the incidence of urea cycle diseases (UCDs) in Finland and determine the course of the various disorders as well as the outcome.
The original data were collected in the years 1998-2001. The diagnoses made after 2001, as well as the current status of the patients, were updated by surveys in the spring of 2007.
We found a total of 55 cases of UCDs in Finland by 2007: 30 cases of ornithine transcarbamylase (OTC) deficiency, 20 of argininosuccinate lyase (ASL) deficiency, 3 of carbamyl phosphate synthetase (CPS-I) deficiency, 1 of type 1 citrullinaemia and 1 of argininaemia. The estimated total incidence of UCDs was 1:39 000. The incidences of individual disorders were: OTC deficiency 1:62 000, ASL deficiency 1:144 000, CPS deficiency 1:539 000 and citrullinaemia 1:1 616 000. Eighteen (33%) of the patients with a diagnosis of UCD have died, most during their first hyperammonaemic crisis. One patient with OTC deficiency has had a liver transplant. Neurological symptoms of varying severity are common among these patients, particularly those with ASL deficiency.
The first survey on the incidence of UCDs in Finland shows some differences in the occurrence rates compared to other countries. Hyperammonaemia, and the neurological symptoms caused by it, can be avoided in most patients with late-onset UCDs with a standard treatment. However, in patients with ASL deficiency, the development of neurological symptoms seems to be inevitable in spite of careful treatment and avoidance of hyperammonaemia.
In the Canada-USA (CANUSA) Study, the dialysis dose was neither randomized nor held constant, was measured at 6 month intervals, and the relative risk of mortality (R) was found to correlate linearly to mean values of weekly peritoneal plus renal urea clearance normalized to volume, (KprT/ V)m, ranging from 1.5 to 2.3. A risk/dose (R/D) function was derived for continuous ambulatory peritoneal dialysis from kinetic criteria for dose equivalency in hemodialysis (HD) and peritoneal dialysis (PD) and the HD R/D function. This PD R/D function was nonlinear with breakpoint from steep to shallow slope at (KprT/V)ud = 2.00, where ud refers to uniform single doses in contrast to mean doses with wide variances on the mean. The predicted decrease in renal urea clearance KrT/V per 6 months of CANUSA follow-up was computed from serial measured KrT/V in the Randomized Dialysis Prescription and Clinical Outcomes Study and showed it to be 0.21 +/- 0.34. The CANUSA (KprT/V)m values were corrected for the distributed values of 3 months decrements in KrT/V, and the population mortality risk at each (KprT/V)m dose level reported in CANUSA was computed from summation of the product of the R/D curve and fractional distribution of (KprT/V)ud values. From these calculations, the authors conclude that maximum (KprT/V)ud level achieved in CANUSA was 2.00, and the study does not define R/D response above this level.