bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue-Type Plasminogen Activator (tPA) and Its Inhibitor (PAI-1) in Patients Treated with Continuous Ambulatory Peritoneal Dialysis
Authors: Opatrný Jr. Karel , Opatrná Sylvie , Vít Ladislav , Opatrný Karel 
Published: April 2003

<b>Aim:</b> To establish whether the values of two key enzymes of fibrinolysis, tissue-type plasminogen activator (tPA) and its inhibitor (PAI-1), differ between patients treated with continuous ambulatory peritoneal dialysis (CAPD) and healthy volunteers and whether plasma and dialysate tPA and PAI-1 values vary during one exchange of dialysis solution. <b>Methods:</b> A total of 11 patients with chronic renal failure, treated with CAPD during the peritoneal equilibration test (in addition with blood sampling at time 0), and a control group of 11 healthy volunteers were examined. To identify the factors involved in the changes in tPA and PAI-1, 9 CAPD patients were subsequently monitored, in a crossover manner, during dialysis with solutions of 1.36 and 3.86% dextrose and off dialysis. <b>Results:</b> Compared with healthy individuals, CAPD-treated patients showed a significantly lower tPA activity (0.39 vs. 0.81 IU/ml, p < 0.05). Changes in plasma fibrinolysis during one exchange of dialysis solution were characterized mainly by a decrease in PAI-1 concentrations and activities caused by the circadian rhythm of fibrinolysis. To explain, in the crossover part of the study, the values of plasma PAI-1 antigen at time 0 (07.00 h) and at time 2 (09.00 h) were 9.4 versus 6.5 ng/ml with the 1.36% solution (p < 0.05), 8.2 versus 4.9 with the 3.86% solution (p < 0.05), and 14.1 versus 9.1 ng/ml off dialysis (p < 0.01). Compared to baseline (0 ng/ml with 1.36 as well as 3.86% solutions), the levels of PAI-1 antigen in dialysis solution rose, apparently due to local production in the peritoneal cavity, to 0.5 ng/ml (p < 0.05) with the 1.36% solution, to 0.7 (p < 0.05) with the 3.86% solution after a 2-hour dwell time, and to 1.6 (p < 0.05) and 1.3 ng/ml (p < 0.05) after a 4-hour dwell time, respectively. Hence, the different dextrose levels in the dialysis solutions had no effect on the monitored parameters of fibrinolysis. <b>Conclusion:</b> The lower activity of plasma tPA, and the increase in PAI-1 levels in dialysis solutions may contribute to the development of thromboses in CAPD patients and to fibrin formation on the peritoneal surface with consequences such as peritoneal fibrosis.
Atrial Natriuretic Peptide Increases Urodilatin in the Circulation
Authors: Vesely David L. , Overton Rose M. , Blankenship Mary , McCormick Michael T. , Schocken Douglas D. 
Published: April 2003

<b>Background:</b> Urodilatin is a 32-amino-acid (AA) peptide formed in the kidney. <b>Methods:</b> High-performance gel permeation chromatography and high-pressure liquid chromatography evaluation of plasma followed by sensitive urodilatin and atrial natriuretic peptide (ANP) assays revealed that urodilatin does circulate distinctly from ANP. <b>Results:</b> Urodilatin circulates at very low levels (i.e 9–12 pg/ml). Infusion of ANP increased the circulating concentration of urodilatin 135-fold (p < 0.001), suggesting that some of the effects of ANP may be mediated by urodilatin while long-acting natriuretic peptide, vessel dilator, and kaliuretic peptide did not affect urodilatin in healthy humans (n = 30). Only ANP decreased the renal clearance of urodilatin (60–75%, p < 0.01). Urodilatin was metabolized into peptides smaller than 5 AAs as well as excreted intact into urine. <b>Conclusion:</b> Urodilatin circulates and is increased by ANP in humans.
Effect of Intravenous Calcitriol on Cardiac Systolic and Diastolic Function in Patients on Hemodialysis
Authors: Lemmilä Satu , Saha Heikki , Virtanen Vesa , Ala-Houhala Ilpo , Pasternack Amos 
Published: April 2003

The systolic and diastolic function of the heart of hemodialysis (HD) patients and the effect of intravenous vitamin D therapy on cardiac function was studied by Doppler and digitized M-mode echocardiography in 10 HD patients before and after 3–4.5 months of calcitriol therapy. Calcitriol was administered intravenously 1–3 times a week at a dose of 1–2 µg after the dialysis sessions. Ten age- and sex-matched healthy controls were also examined echocardiographically. Before calcitriol therapy cardiac wall thicknesses (interventricular septum, posterior wall) and left ventricle (LV) dimensions (end diastolic, end systolic) were greater, and LV diastolic (peak late diastolic velocity, peak early diastolic velocity/peak late diastolic velocity ratio, isovolumic relaxation time) and systolic (fractional shortening) function was impaired in HD patients as compared to controls. The LV posterior wall thickness was related to plasma parathyroid hormone (PTH; r = 0.70, p = 0.01) in the patients. Calcitriol therapy raised serum ionized Ca from 1.23±0.04 to 1.33 ± 0.04 mmol/l and reduced PTH from 41.1±10.7 to 34.2±11.7 pmol/l (29±11%). Calcitriol therapy did not cause any significant changes in cardiac function in the whole patient group. However, in a subgroup of 5 patients with severe but controllable hyperparathyroidism (PTH >3 times upper normal margin) the LV dimensions and systolic function improved (LV end systolic dimension from 39.0 ± 4.0 to 31.3 ± 2.9 mm, p = 0.03; LV end diastolic dimension from 57.7 ± 3.1 to 53.4 ± 3.0 mm, p = 0.06; fractional shortening from 33 ± 4 to 42 ± 3%, p = 0.03). The diastolic indices improved also, but not significantly. In conclusion, left ventricle hypertrophy and systolic and diastolic dysfunction was observed in HD patients. Intravenous calcitriol therapy improved cardiac function in patients with severe secondary hyperparathyroidism.
Plasma Concentration of Brain Natriuretic Peptide as an Indicator of Cardiac Ventricular Function in Patients on Hemodialysis
Authors: Nitta Kosaku , Kawashima Akira , Yumura Wako , Naruse Mitsuhide , Oba Takashi , Kabaya Takashi , Nihei Hiroshi 
Published: April 2003

The plasma concentration of human brain natriuretic peptide (BNP) was measured by immunoradiometric assay in patients on maintenance hemodialysis (HD) to assess the possible relationship between the plasma levels of this peptide and cardiac ventricular function, as judged by M-mode echocardiography. The plasma BNP levels in the pre-HD state were significantly higher (688.5 ± 154.5 pg/ml) than those of healthy subjects (<40 pg/ml). In addition, the plasma BNP levels were slightly decreased during HD (post-HD, 617.3 ± 157.1 pg/ml). There was no correlation between the plasma levels of BNP and body weight changes during HD. The mean plasma BNP level was significantly higher in the group of patients with a low left ventricular ejection fraction (EF < 60%) than in the group with a normal EF. In the patients as a whole, there was an inverse correlation between plasma BNP levels and EF. Moreover, a positive correlation was found between plasma BNP levels and left ventricular mass index (r = 0.57, p < 0.05). These results suggest that plasma BNP levels increase in response to chronic stimulation in accordance with increased cardiac load, and that they may be a possible indicator of reduced ventricular function in HD patients.
Role of the Calices in Urine Flow with Characterization of a Caliceopelvic Sphincter and Reflex
Authors: Shafik Ahmed 
Published: April 2003

<b>Aim:</b> To study the role of the caliceal system in urine flow. <b>Methods:</b> Eight patients (6 men, 2 women; mean age 42.6 ± 7.6 years) with an upper polar renal mass (6 renal cysts; 2 hypernephromas) which did not encroach on the pelvicaliceal system were studied. After mass removal, a manometric catheter was introduced into one of the intact calices. Another catheter was introduced through the same calix, and the calix was filled with saline in increments of 0.1 ml, and the caliceal, caliceopelvic junction (CPJ), and renal pelvis pressures were recorded. The catheter was moved to the renal pelvis, and the pressure response of the aforementioned sites to renal pelvic filling with saline in increments of 1 ml was registered. The effect of filling of the locally anesthetized calix on the pelvicaliceal pressure was also determined. <b>Results:</b> Caliceal filling resulted in a rise of the caliceal (p < 0.01) and a drop of the CPJ (p < 0.01) pressures with no pressure response in the renal pelvis. Renal pelvic filling produced a rise of renal pelvic (p < 0.01) and CPJ (p < 0.05) pressures; the caliceal pressure showed no change (p > 0.05). Filling of the anesthetized calix or renal pelvis produced no significant pressure changes in calix, CPJ, or renal pelvis (p > 0.05). <b>Conclusions:</b> The CPJ dilatation upon caliceal contraction suggests a reflex relationship which we named ‘caliceopelvic inhibitory reflex’. The reflex is suggested to effect caliceal evacuation. On the other hand, CPJ closure upon renal pelvic contraction postulates another reflex relationship which we designated ‘pelvicaliceal excitatory reflex’. This reflex seems to prevent pelvicaliceal reflux. It is suggested that a ‘functional’ sphincter exists at the CPJ.
Delivered Dialysis Dose Is Suboptimal in Hospitalized Patients
Authors: Obialo Chamberlain I. , Hernandez Beverly , Carter Dianne 
Published: April 2003

Underdialyzed patients have high hospitalization and mortality rates. It is unclear if such patients receive adequate dialysis during hospitalization. In this cross-sectional study, we evaluated single treatment delivered dialysis dose during hospitalization and compared this to the dosage received at the free-standing outpatient clinics in the same patients. Eighty-four patients (54% male) aged 23–63 years (means ± SD 55.5 ± 14.6) who have been on dialysis for at least 3 months were evaluated. Hypertension and diabetes were the most common diagnoses, while thrombosed graft or fistula accounted for 40% of admissions. The mean dialysis treatment time (Td) was 30 min longer in the outpatient (OP) setting than the hospital (H): 3.6 ± 0.3 vs. 3.1 ± 0.2 h (p < 0.0001). Attained blood flow (QB) was 15% greater in the OP than H: 394 ± 40 vs. 331 ± 54 ml/min (p < 0.0001). The Kt/V was analyzed in 49 of 84 patients; the OP Kt/V was 20% greater than the H Kt/V: 1.38 ± 0.2 vs. 1.11 ± 0.1 (p < 0.0001). A further breakdown of H Kt/V according to access and membrane types showed that patients with functional grafts/fistula had a higher Kt/V than those with temporary accesses 1.14 ± 0.1 vs. 1.07 ± 0.1 (p = 0.01). We conclude that hospitalized patients receive suboptimal dialysis dose, this could have a negative impact on survival if hospitalization is recurrent and prolonged. Kinetic modeling should be routinely performed in such patients and Td should be increased in patients with temporary accesses.
Renal Reabsorption of Phosphate in Children with Sickle Cell Anemia
Authors: Al-Harbi Nafa , Annobil Samuel Hagan , Abbag Fuad , Adzaku Festus , Bassuni Wagih 
Published: April 2003

It has previously been reported that in adult patients with sickle-cell anemia the serum phosphate value and the maximum tubular reabsorption of phosphate per liter of glomerular filtrate (TmP/GFR) were significantly higher than in normal controls. This does not appear to have been studied in children with sickle cell anemia (young sicklers) and this prompted us to assess renal phosphate reabsorption in this group of patients. We looked at serum phosphate level and calculated renal phosphate reabsorption (TP/GFR) in children taking random urine and blood samples at the same time and using the formula TP/GFR = Sp – Up × SCr: UCr, in 30 young sicklers all of whom had normal renal function (mean age 7.3 years) and 40 normal matching controls (mean age 6.5 years). The mean serum phosphate value in young sicklers was significantly lower than in controls (4.3 against 5.3 mg/dl) while the mean value of TP/GFR was 4.09 ± 0.74 mg/dl in young sicklers compared to 4.65 ± 0.75 mg/dl in the control group (p = 0.0026). Therefore, the TP/GFR in young sicklers was also significantly lower (p = 0.0026) than in the control group. This may be explained by the high serum level of parathyroid hormone reported previously in patients with sickle cell anemia which is expected to lower phosphate reabsorption (TmP/GFR and TP/GFR are identical in children). The lower serum phosphate value and TP/GFR in younger sicklers seems to be in contrast with the relatively high serum phosphate value and TP/GFR previously reported in adults with sickle cell anemia.
Pravastatin Treatment of Very Low Density, Intermediate Density and Low Density Lipoproteins in Hypercholesterolemia and Combined Hyperlipidemia Secondary to the Nephrotic Syndrome
Authors: Toto Robert D. , Grundy Scott M. , Vega Gloria Lena 
Published: April 2003

<i>Background/Aims:</i> In the current study pravastatin was used in nephrotic syndrome patients with hypercholesterolemia and combined hyperlipidemia to test whether the drug decreases production of LDL and reduces levels of VLDL and IDL. <i>Methods:</i> Thirteen patients (7 with high LDL alone and 6 with high VLDL, IDL and LDL) were randomized in a placebo-controlled study that had a crossover design. Patients were treated 8 weeks with pravastatin (40 mg/day) (or placebo) and switched to the corresponding placebo/drug for another 8 weeks. During each phase of the trial, patients had measurement of plasma levels of lipoprotein lipids, and turnover rates of autologous LDL apo B. <i>Results:</i> Pravastatin increased LDL clearance by 16.7% and reduced total cholesterol content per LDL particle in patients with hypercholesterolemia. In combined hyperlipidemia, LDL clearance increased by 19% and there was no significant change in the production of LDL-apo B. Levels of VLDL+IDL apo B were not reduced significantly, while the total cholesterol content of these particles was reduced by 31.7%. <i>Conclusion:</i> Pravastatin effectively reduced LDL levels in both types of dyslipidemia by increasing LDL clearance. Treatment had no effect on production of LDL or on levels of VLDL+IDL-apo B. Thus, pravastatin increases LDL clearance. Statins do not seem to affect production rates of apo B-containing lipoproteins. Treatment of combined hyperlipidemia may require pravastatin and an added drug targeted to normalize levels of VLDL and IDL.
Elevation of Serum Levels of Metalloproteinase-1, Tissue Inhibitor of Metalloproteinase-1 and Type IV Collagen, and Plasma Levels of Metalloproteinase-9 in Polycystic Kidney Disease
Authors: Nakamura Tsukasa , Ushiyama Chifuyu , Suzuki Shingo , Ebihara Isao , Shimada Noriaki , Koide Hikaru 
Published: April 2003

Several studies on polycystic kidney disease (PKD) have revealed a number of extracellular matrix (ECM) abnormalities, suggesting that an abnormal ECM plays a role in the development of tubular cysts. Cystic kidney tubules synthesize and secrete high levels of metalloproteinases (MMP), which may participate in the restructuring of the tubular basement membrane. The aim of the present study was to determine whether serum MMP-1, tissue inhibitor of metalloproteinase (TIMP)-1, and type IV collagen levels, and plasma MMP-9 levels were altered in patients with PKD. Sixteen patients with autosomal dominant polycystic kidney disease, and 20 healthy controls were included in this study. Specific enzyme immunoassays were used to measure MMP-1, MMP-9, TIMP-1, and type IV collagen levels. Serum MMP-1 (14.8 ± 3.6 ng/ml), TIMP-1 (288.6 ± 48.6 ng/ml), and type IV collagen (192.6 ± 38.8 ng/ml) concentrations, and plasma MMP-9 (90.2 ± 26.8 ng/ml) concentrations in patients with PKD were significantly higher than those in healthy controls (MMP-1; 6.6 ± 0.9 ng/ml, p < 0.01, MMP-9; 36.4 ± 12.2 ng/ml, p < 0.01, TIMP-1; 164.6 ± 22.8 ng/ml, p < 0.01, and type IV collagen; 86.6 ± 14.2 ng/ml, p < 0.001). The present results suggest that ECM abnormalities associated with cystic kidney may result from aberrant degradation as well as from abnormal synthesis of ECM components.
Acute Effects of Oral Calcium Load on Parathyroid Function and on Bone Resorption in Young Men
Authors: Guillemant Josette , Le Huyen-Tran , Maria Annick , Guillemant Serge 
Published: April 2003

<i>Aim: </i>The aim of the present study was to check whether a calcium oral load was able to inhibit bone resorption as assessed by urinary excretion of a new bone marker, type 1 collagen cross-linked C-telopeptide (CrossLaps<sup>TM</sup>), in healthy young male adults. <i>Methods:</i> Twenty healthy young male adults (age 22 ± 2 years) were studied. In one series of assays, an oral calcium load of 1 g of elemental calcium as calcium citrate dissolved in 200 ml of low-calcium water was ingested, while in another series of assays the subjects ingested 200 ml of water alone. Blood samples were collected before and 1, 2, 3 and 4 h after the intake of calcium. Urine was collected at 2-hour intervals, i.e. before and for 4 h after the intake of calcium. Serum ionized calcium, phosphate and intact parathormone (iPTH) were measured at each time point. Urinary calcium, phosphate, creatinine and CrossLaps (as a ratio to creatinine) were measured in each urine sample. <i>Results:</i> Calcium intake was associated with very significant (ANOVA, p < 0.001) increases in serum ionized calcium and decreases in PTH. After calcium intake, measurements of urinary CrossLaps showed a progressive statistically significant (ANOVA, p < 0.001) decrease (–20% at 2 h and –55% at 4 h), whereas after ingestion of water, the changes were modest and not statistically significant. <i>Conclusions:</i> The present results show that bone resorption as assessed by urinary excretion of CrossLaps can be significantly suppressed by the ingestion of a 1-gram calcium load and attest that calcium supplementation has an acute effect on bone metabolism.
Leptin and Serum Erythropoietin in Hemodialyzed and Peritoneally Dialyzed Uremic Patients during rHuEPO Therapy
Authors: Małyszko Jolanta , Zbroch Edyta , Wołczyński Sławomir , Małyszko Jacek S. , Hryszko Tomasz , Myśliwiec Michał 
Published: April 2003

Leptin produced by fat cell has an unanticipated role in hematopoietic system development. We examined the relationships between leptinemia and requirements of erythropoietin (Epo), endogenous Epo levels as well as markers of inflammation: C-reactive protein, tumor necrosis factor α (TNFα) and interleukin-1 (IL-1) in rHuEPO-treated patients maintained on chronic hemodialyses or peritoneal dialyses. The studies were performed on 51 chronically hemodialyzed patients, 20 of them did not receive rHuEPO, 31 subjects received rHuEPO, and 22 patients on CAPD, 13 of them did not receive rHuEPO, 9 subjects were given rHuEPO. In hemodialyzed patients (Epo and Non-Epo group) leptin levels were significantly higher when compared to CAPD patients (Epo and Non-Epo group, respectively). Leptin in peritoneal fluid was significantly higher in the Non-Epo group. In ultrafiltrate, leptin levels were below the detection limit of 0.5 ng/ml. Epo levels in the HD + Epo group were significantly lower than in the HD + Non-Epo group and CAPD + Epo group. TNFα and IL-1 concentrations were significantly lower in both groups of CAPD patients when compared to respective HD groups. Treatment with rHuEPO resulted in nonsignificant decline in serum leptin (p = 0.07 in HD and p = 0.08 in CAPD) and significant leptin loss in peritoneal fluid. It may be of clinical relevance in dialyzed patients. In both groups of Epo-treated patients, positive physiological correlation between leptinemia and BMI disappeared. Leptin levels do not correlate with rHuEPO requirements and serum Epo in dialyzed patients.
Influence of Dialysis Procedure, Membrane Surface and Membrane Material on Iopromide Elimination in Patients with Reduced Kidney Function
Authors: Matzkies F.K. , Reinecke H. , Tombach B. , Kosch M. , Hegger K. , Milius M. , Hohage H. , Kisters K. , Kerber S. , Schaefer R.M. 
Published: April 2003

Haemodialysis for the elimination of contrast medium in patients with advanced renal failure is a common procedure. Even though sufficient elimination with the use of regular low-flux membranes is documented, large differences in results have been reported in prior investigations. We, therefore, compared Cuprophan and polysulfone dialysers with different surface areas to haemofiltration with different amounts of substitution fluid in 40 patients with compromised renal function after coronary angiography. Plasma iodine concentrations were measured by fluorescent excitation analysis. At constant blood flow rates of 200 ml/min, Cuprophan membranes with 1.3 m<sup>2</sup> surface area had a clearance rate of 87 ml/min, whereas polysulfone membranes of comparable size displayed a significantly higher clearance rate of 147 ml/min. Polysulfone membranes with 1.8 m<sup>2</sup> surface area showed a small but insignificant increase in the iodine clearance (162 ml/min), while Cuprophan membranes displayed an increase in clearance rates (121 ml/min). Additional ultrafiltration led to a further increase in the plasma clearance of both membranes and reduced urinary iodine excretion. Haemofiltration was comparable to haemodialysis in terms of efficacy and thus represents an alternative method. Clearance of iopromide during haemodialysis with polysulfone membranes is higher than with Cuprophan membranes. Elimination rates can be further increased by additional ultrafiltration. Haemofiltration is comparable to haemodialysis regarding contrast medium elimination.
Basal Cochlear Lesions Result in Increased Amplitude of Otoacoustic Emissions
Authors: Kakigi Akinobu , Hirakawa Haruo , Harel Noam , Mount Richard J. , Harrison Robert V. 
Published: April 2003

We have measured the changes in transient otoacoustic emissions (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) during and after ototoxic amikacin treatment in an animal (chinchilla) model. TEOAE and DPOAE were recorded from 6 adult chinchillas over a 6-week time course starting just before a 5-day or 7-day treatment period with amikacin sulphate (400 mg/kg/day, i.m.). After final recordings, cochlear morphology was assessed by scanning electron microscopy. Generally, both DPOAE and TEOAE amplitudes change during and after treatment in a systematic fashion. High-frequency components change first, followed by lower-frequency components. We note that there is often a long latency to the onset of changes in otoacoustic emissions (OAE), and that these changes can continue for weeks after treatment. Most importantly we report that when the basal region of the cochlea is damaged in the frequency region above the OAE recording bandwidth (0.6–6 kHz for TEOAE; 1–6.7 kHz for DPOAE), we often find an increase in OAE amplitudes. More specifically, we note that as a cochlear lesion progresses apically, there is often a transient increase in a frequency-specific OAE before it reduces or is lost. Our results suggest that the increase in OAE amplitudes precedes the expression of detectable cochlear pathology.