Increased plasma ghrelin levels in chronic renal failure are not associated with hemodynamic parameters

BACKGROUND/AIMS

Hardly anything is known about the effect of renal function on plasma ghrelin levels. Ghrelin is an orexigenic hormone with important hemodynamic effects. We examined differences in plasma ghrelin levels between chronic renal failure (CRF) patients and healthy subjects, and ghrelin's relationship with indices of left ventricular (LV) function.

METHODS

Fasting total plasma ghrelin levels were measured in 122 CRF patients (57 on, 65 not on hemodialysis) and 57 control subjects. Indices of LV function were evaluated using echocardiography.

RESULTS

Total plasma ghrelin levels were higher in patients with CRF compared to controls, but were not different between patients on and those not on hemodialysis. In a multivariate linear regression model, presence of kidney dysfunction explained 41 % of the variability of ghrelin values. The etiology of renal failure (diabetic nephropathy or not) had no influence on ghrelin levels in the renal patients. Ghrelin levels were not associated with indices of LV systolic function or blood pressure in these patients.

CONCLUSION

Fasting plasma ghrelin concentrations are higher in CRF patients regardless of their need for hemodialysis compared to controls. The etiology of renal failure does not have any effect on plasma ghrelin levels. In addition, ghrelin levels are not associated with hemodynamic parameters in patients with CRF.

Plasma adiponectin concentrations in patients with chronic renal failure: relationship with metabolic risk factors and ischemic heart disease

AIMS

To compare plasma adiponectin levels between healthy controls and patients with chronic renal failure and to examine for a relationship between plasma adiponectin levels and ischemic heart disease as well as aortic distensibility which is an early marker of atherosclerosis.

METHODS

We included 89 patients with CRF (45 on and 44 not on hemodialysis) and 70 controls in a cross-sectional study. Plasma adiponectin levels were measured by radioimmunoassay. Aortic distensibility was assessed by high-resolution ultrasonography.

RESULTS

Plasma adiponectin levels were significantly almost twice as high in patients with renal failure compared to controls (9.7 +/- 1.1 vs. 5.4 +/- 0.6 microg/ml, p < 0.0001). No significant differences were found between renal patients on hemodialysis and not on hemodialysis (p = 0.71). Multivariate linear regression analysis in the renal patient group demonstrated a significant negative relationship between plasma adiponectin levels and ischemic heart disease (p = 0.02). The same analysis in the control subjects group showed a significant, negative relationship between plasma adiponectin levels and body mass index (p = 0.02) and a highly significant positive relationship with the high density lipoprotein cholesterol (p < 0.0001). In the total study population, glomerular filtration rate was the only independent predictor of plasma adiponectin concentrations. Aortic distensibility was lower in renal patients than in controls at a high level of significance (p < 0.0001). However, no significant relationship could be found between plasma adiponectin and aortic distensibility in either the controls or the renal patients.

CONCLUSIONS

Plasma adiponectin levels are almost twice as high in patients with chronic renal failure in comparison with healthy controls, but not different between renal patients on and those not on hemodialysis. In addition, low plasma adiponectin levels are strongly associated with ischemic heart disease, but not with aortic distensibility in chronic renal failure.

Evaluation of valaciclovir dosage reduction in continuous ambulatory peritoneal dialysis patients

In continuous ambulatory peritoneal dialysis (CAPD) patients, acyclovir-induced neurotoxicity is reported to be associated with high serum drug levels even when following the recommended reduced doses for this renal failure population. In view of the high oral bioavailability of valaciclovir (the L-valyl ester of acyclovir) the risk of neurotoxicity becomes more prominent. The present study was conducted in 12 CAPD patients who were administered a single oral dose of 500 mg valaciclovir. Acyclovir was analyzed by high-performance liquid chromatography. Relative pharmacokinetic parameters were estimated based on acyclovir concentrations at 8, 12 and 24 h post-dose. High inter-patient variations were observed with acyclovir apparent total clearance 7.238 +/- 4 l/h and half-life (T1/2) 22.27 +/- 16.82 h. However, dosage simulations confirmed supratherapeutic acyclovir concentrations for all participants when following the recommended dose of 1,000 mg valaciclovir/24 h for varicella zoster infections.

Isolation and characterization of skin-type, type I antifreeze polypeptides from the longhorn sculpin, Myoxocephalus octodecemspinosus

The antifreeze polypeptides (AFPs) are found in several marine fish and have been grouped into four distinct biochemical classes (type I-IV). Recently, the new subclass of skin-type, type I AFPs that are produced intracellularly as mature polypeptides have been identified in the winter flounder (Pleuronectes americanus) and the shorthorn sculpin (Myoxocephalus scorpius). This study demonstrates the presence of skin-type AFPs in the longhorn sculpin (Myoxocephalus octodecemspinosus), which produces type IV serum AFPs. Using polymerase chain reaction-based methods, a clone that encoded for a type I AFP was identified. The clone lacked a signal sequence, indicating that the mature polypeptide is produced in the cytosol. A recombinant protein was produced in Escherichia coli and antifreeze activity was characterized. Four individual Ala-rich polypeptides with antifreeze activity were isolated from the skin tissue. One polypeptide was completely sequenced by tandem MS. This study provides the first evidence of a fish species that produces two different biochemical classes of antifreeze proteins (type I and type IV), and enforces the notion that skin-type AFPs are a widespread biological phenomenon in fish.

Renal amyloidosis as a first manifestation of Familial Mediterranean Fever

Amyloid nephropathy was the presenting symptom in a case of Familial Mediterranean Fever (FMF). As recent progress in molecular pathology permits the detection of asymptomatic FMF individuals, it is suggested that relevant cases of renal amyloidosis should be tested for FMF mutations.

Labeling effects on the isoelectric point of green fluorescent protein

We studied the effects of fluorescent labeling on the isoelectric points (pI values) of proteins using capillary isoelectric focusing with laser-induced fluorescence detection (cIEF-LIF). Specifically, we labeled green fluorescent protein (GFP) from the jellyfish Aequorea victoria with the fluorogenic dye 3-(2-furoyl)quinoline-2-carboxaldehyde (FQ). cIEF-LIF was used to monitor the native fluorescence of GFP and showed pI changes in GFP's FQ-labeled products. Multiple labeling of GFP with FQ produced a series of products with pI values shifted towards a low pH. We verified cIEF-LIF results with traditional slab gel IEF. Our cIEF-LIF technique can routinely detect 10(-11) M of FQ-labeled protein, whereas traditional slab gel IEF with silver stain detection gives detection limits of 10(-7) M in the same samples.

Capillary electrochromatography with thermo-optical absorbance detection for the analysis of phenylthiohydantoin-amino acids

Capillary columns were packed with 3 microns C18 stationary phase, interfaced with an ultraviolet-laser based thermo-optical absorbance detector, and evaluated for separation of a mixture of phenylthiohydantoin-amino acids. These columns demonstrated consistent performance with a relative standard deviation (RSD) for migration time of less than 1.5% and a separation efficiency of 216,000 plates/m for the electroosmotic flow marker, thiourea. The thermo-optical absorbance detector was based on a 248 nm krypton-fluoride excimer laser. Detection limits (3 sigma) ranged from 1.6 to 4.8 x 10(-7) M phenylthiohydantoin (PTH)-amino acid injected onto the column, which is a factor of three superior to those obtained in micellar electrokinetic chromatographic analysis of these compounds. A mixture of 17 PTH amino acids was injected onto the capillary; 13 components were nearly baseline resolved in 14 min.

Visceral leishmaniasis in renal transplant recipients: successful treatment with liposomal amphotericin B (AmBisome)

Visceral leishmaniasis (VL) is a rare disease in renal transplant recipients. Liposomal amphotericin B (AmBisome) is known to be effective against VL. However, previously there has been no experience with administration of such treatment to renal transplant recipients. We report herein four patients with VL complicating renal transplantation who were treated successfully with liposomal amphotericin B (total dose, 23-40 mg/kg). Neither adverse reactions nor clinical relapses of VL were observed.

Acute renal failure in an adult patient with Henoch-Schoenlein purpura after episode of macroscopic hematuria

A case of severe prolonged acute renal failure with a histological picture of acute tubulointerstitial lesions in an adult patient with Henoch-Schoenlein purpura after an episode of macroscopic hematuria is described. The macroscopic hematuria lasted only for 5 days and the renal biopsy was performed 50 days after the end of the macroscopic hematuria. Restoration of renal function was not complete six months after the beginning of improvement. Fewer than 65 cases of acute renal failure due to tubulointerstitial nephritis in patients with glomerulonephritis and after episode of macroscopic hematuria have been described in the international literature. Only one of these patients was suffering from Henoch-Schoenlein purpura.

Sodium dodecyl sulfate-capillary electrophoresis of proteins in a sieving matrix utilizing two-spectral channel laser-induced fluorescence detection

We report a method for protein labeling, separation by capillary electrophoresis in a polymer sieving matrix, and detection by laser-induced fluorescence. Different dyes are used to label standard and sample proteins. A two-spectral channel detector resolves fluorescence from the sample and standards. Comparison of the migration time of the sample and standards permits the precise determination of molecular weight, irrespective of variations in run-to-run migration times.

Cationic and anionic polymeric additives for wall deactivation and selectivity control in the capillary electrophoretic separation of proteins in food samples

Both cationic and anionic polymeric additives were used for the capillary electrophoretic separation of proteins in food samples. The cationic polyelectrolyte polydiallyldimethylammonium chloride was more effective in minimizing protein-wall interactions at pH 3 than at pH 7, presumably due to greater repulsion between the adsorbed polymer and proteins. Improved resolution was observed in the presence of the co-additive sodium octanesulphonate, presumably due to ion-pairing interactions with protein sample components. The anionic polymer dextran sulfate produced relatively high efficiencies, 120,000-180,000 theoretical plates, for protein separation, presumably because the polymer adsorbed to the capillary wall, rendering the surface more hydrophilic. In addition to reduced protein-wall interactions, improved resolution was observed, presumably due to analyte-polymer ion-exchange/ion-pairing interactions. When poly(vinyl sulphonic acid) was used instead of dextran sulfate, broader profiles were obtained and fewer components were resolved, presumably due to reduced wall deactivation that is related to the lower hydrophilicity of poly(vinyl sulphonic acid).

Henoch-Schoenlein purpura and acute interstitial nephritis after intravenous vancomycin administration in a patient with a staphylococcal infection

We describe a case of Henoch-Schoenlein purpura, associated with oliguric acute renal failure due to acute interstitial nephritis histologically proven, in a patient with a staphylococcal chest infection. The clinical syndrome appeared twice after vancomycin administration and yielded on the withdrawal of the drug. As pathogenetic mechanism we propose an anaphylactoid reaction either to vancomycin or to a staphylococcal glycoprotein released after breakdown of the microbial cells caused by vancomycin.

The 10 years single center experience of using elderly donors for living related kidney transplantation

The use of elderly donors has been advocated to expand the organ donor pool because of increased needs and organ shortage. The aim of the study was to analyse whether old age of donors affects the outcome of renal transplantation and the long term safety of retrieval for the donors. We present data of 335 consecutive living related kidney transplants, performed in our centre the last 10 years, where in 174 patients the donor was less than 60 years of age, while in the rest 161 patients the donor was more than 60 years of age. No statistical difference was noted in either group at the incidence of irreversible acute rejections, early acute tubular necrosis, vascular complications and patient deaths. The graft survival was 86.7%, 80.4% and 78.1% for the 3rd, the 5th and the 8th year for the younger group of donors, while it was 83.6%, 78.2% and 67.8% for the older group (p = 0.13). Patient survival of the younger group was 95.9%, 94.7% and 94.7%, while for the older was 94.4%, 92.0% and 89.2% for the 3rd, the 5th, and the 8th year post transplantation (p = 0.24). Functional rehabilitation and quality of life were good in donors and recipients of both groups. These results suggest that renal transplantation from elderly donors offers comparable results from those obtained from younger donors.

Cationic polymers for selectivity control in the capillary electrophoretic separation of inorganic anions

The capillary electrophoretic (CE) separation of the inorganic anions bromide, chloride, nitrate, nitrite, fluoride, sulfate and phosphate is described in 0.005 mol/L sodium chromate electrolyte in the presence of soluble polydisperse ionic polymers (polyelectrolytes). The cationic polyelectrolytes used were as follows: poly(1,1-dimethyl-3,5-dimethylenepiperidinium) chromate, hexadimethrine chromate, poly(1,1-dimethyl-3,5-dimethylenepyrrolidinium) chromate and ((diethylamino)ethyl)-dextran chromate in the concentration range 0.004-0.6% (w/v). These polyelectrolytes were shown to be capable of reversing the direction of the electroosmotic flow as well as inducing changes in analyte electrophoretic mobility, separation selectivity, and resolution. Changes in electrophoretic mobility by as much as 25% were observed for the sulfate anion, and the resolution of fluoride and phosphate was enhanced by a factor of 7.8. In the presence of 0.05-0.17% w/v poly(1,1-dimethyl-3,5-dimethylenepyrrolidinium) chromate at pH 8, separation currents were found to increase only slightly as compared to an electrolyte containing equivalent amounts of sodium chromate. Electroosmotic flow was also found to be fairly constant (+/- 16%) in the pH range 6.55-10.02 for 0.01% (w/v) poly(1,1-dimethyl-3,5-dimethylenepiperidinium) chromate at an ionic strength of 0.04, compared to a 400% change in the absence of the polyelectrolyte. The reproducibility of the electroosmotic mobility was between 0.36 and 6% RSD, and analyte electrophoretic mobility was between 0.01 and 1.6% RSD. Peak height reproducibility was 0.2-8.0% RSD. Separation efficiencies were between 258,000 and 780,000 theoretical plates, and detection limits were between 4.4 x 10(-7) and 9.1 x 10(-6) mol/L.

Hepatitis C virus infection among Greek renal transplant patients

In this study, the prevalence of hepatitis C virus (HCV) infection among renal transplant recipients was high, directly proportional to the haemodialysis time before transplant and inversely proportional to the time after this. There was evidence of previous infection with hepatitis B virus (HBV), and a high prevalence of abnormal liver function tests. Virus induced chronic hepatitis lesions were rare, probably as a result of immunosuppression.

Antibodies against hepatitis C virus among renal transplant patients in Greece

To evaluate the prevalence of hepatitis C virus (HCV) infection in Greek renal transplant (RT) patients and its association with abnormal liver function tests (LFTs), serum anti-HCV was determined (Ortho-ELISA test system) in 206 RT and 245 haemodialysis patients (HD) as controls. The prevalence (10.2%) of anti-HCV in RT patients was significantly higher (P < 0.0001) than in the Greek general population (0.7%) and lower (P < 0.0001) than in the HD patients (23.8%), and was not related to the patients' age, post-transplant time or pre-transplant HD time. None of the anti-HCV RT patients was HBsAg+, whereas 13 (62%) and 12 (57%) of them were anti-HBsAg+ and anti-HBc+, respectively. The incidence of abnormal LFTs in anti-HCV+ HBsAg- and anti-HCV- HBsAg+ RT patients was similar. Our findings indicate that: (a) the prevalence of serum anti-HCV in the Greek RT population is high, although considerably lower than in HD pts; (b) anti-HCV+ RT patients have a high incidence of abnormal LFTs, comparable to that seen in HBsAg+ RT patients; and (c) in a substantial proportion of anti-HCV+ RT patients there is evidence of previous HBV infection.

Cefetamet pivoxil in acute pyelonephritis: an open study

Fifty-five adult patients with acute uncomplicated pyelonephritis were investigated in an open, prospective, randomized comparative study in which 31 patients were allocated to receive 1000 mg cefetamet pivoxil twice daily (or 2000 mg once daily) and 24 to receive 1000 mg cefadroxil twice daily, given orally for 10 to 15 days. Both groups were comparable for age, sex and body weight. Clinical signs and symptoms, i.e. flank tenderness, dysuria, urgency and pyuria, subsided somewhat more rapidly with cefetamet pivoxil, while defervescence was obtained by Day 3 +/- 1 in both groups. Twenty-nine of the cefetamet pivoxil patients were assessed bacteriologically. The pathogens isolated prior to treatment were E. coli (22), Proteus mirabilis (5), P. vulgaris (1) and P. stuartii (1). All 29 patients had sterile urine at treatment end. In the 22 assessable patients in the cefadroxil group, the pathogens isolated before treatment were E. coli (17), P. mirabilis (3), and K. pneumoniae (2). Six patients had relapsed at treatment end (5 E. coli and 1 P. mirabilis). Patients were re-assessed at follow-up, usually 2 to 4 weeks after the end of treatment. Four of the 29 patients in the cefetamet pivoxil group showed relapse (3 E. coli and 1 P. mirabilis) as did a further 3 in the cefadroxil group (2 E. coli and 1 P. mirabilis). The overall therapeutic outcome was considered as successful, i.e. cure or improvement, in 89.7% of the cefetamet pivoxil patients and 72.7% of those who had received cefadroxil. Tolerability was satisfactory for both trial drugs and there were only a few mild to moderately severe adverse events reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetics of intravenous cefetamet and oral cefetamet pivoxil in patients with renal insufficiency

The pharmacokinetics of cefetamet after a short intravenous infusion of cefetamet (515 mg) and oral administration of 1,000 mg of cefetamet pivoxil were studied in 9 healthy subjects and in 38 patients with various degrees of renal impairment. The results showed that cefetamet elimination was dependent on renal function. After intravenous dosing, total body (CLS), renal (CLR), and nonrenal (CLNR) clearances were linearly related to creatinine clearance (CLCR; r = 0.95, 0.92, and 0.59, respectively). Elimination half-life (t1/2 beta) was prolonged from 2.46 +/- 0.33 h in normal subjects to 29.1 +/- 13.9 h in patients with CLCR of less than 10 ml/min per 1.73 m2. Correspondingly, CLS and CLR decreased from 1.77 +/- 0.27 and 1.42 +/- 0.25 ml/min per kg to 0.14 +/- 0.04 and 0.04 +/- 0.03 ml/min per kg, respectively. The volume of distribution at steady state (0.298 +/- 0.049 liter/kg) for cefetamet was not altered by renal insufficiency (P greater than 0.05). After oral administration, the elimination parameters, t1/2 beta and CLR, were insignificantly different from the intravenous data (P greater than 0.05). Furthermore, the bioavailability (F) of cefetamet pivoxil (45 +/- 13%) was not altered by renal failure (P greater than 0.05). However, maximum concentration in plasma and the time to achieve this value were significantly increased (5.86 +/- 0.74 versus 14.8 +/- 6.14 micrograms/ml and 3.9 +/- 1.1 versus 8.4 +/- 1.7 h, respectively; P less than 0.05). Based on these observations, it is recommended that patients with CLcr of <10 ml/min per 1.73 m2 and between 10 and 39 ml/min per 1.73 m2 be given one-quarter of the normal daily dose either once or twice daily. Patients with CLcr between 40 and 80 ml/min per 1.73 m2 should receive one-half of the normal dose twice daily. For patients with CLcr of <10 ml/min per 1.73 m2, it would be recommended that they receive a normal standard dose as a loading dose on day 1 of treatment.