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Influenza viruses cause annual epidemics and occasional pandemics and thus represent a significant public health problem together with considerable economic consequences. As current influenza virus vaccines do not provide the best immunological protection, plasmid DNA vaccines have been seen as a potential alternative due to the stimulation of both B- and T-cell responses without the presence of any infectious agent and because they are easily produced, highly stable and safe. From this standpoint, several downstream methods have been proposed to obtain high quantities of pharmaceutical grade supercoiled plasmid DNA. This work describes a rapid process, based on ion exchange chromatography using an ethylenediamine (EDA) monolith for the purification of an experimental DNA influenza vaccine. The purification process allowed a significant reduction of the host contaminants, such as proteins, RNA and genomic DNA and the DNA vaccine recovery with a purity degree of 97.1% and a step yield of 47%. Finally, both transfection efficiency of the influenza vaccine and its cytotoxicity in two types of eukaryotic cell lines were tested in order to compare with the same plasmid DNA purified with a commercial kit.

Background/Aims: Hepatitis C virus infection remains prevalent among patients undergoing long-term haemodialysis and has a detrimental impact on survival in this population. Antiviral therapy for chronic hepatitis C in haemodialysis patients is still a challenge to clinicians. The aim of the current study is to evaluate the efficacy and safety of therapy with pegylated interferon, alone or combined with ribavirin, for chronic hepatitis C among patients undergoing long-term hemodialysis. Methods: We conducted a retrospective, multicenter cohort trial with monotherapy (pegylated interferon) (n=21) or combined antiviral therapy (pegylated interferon plus ribavirin) (n=5) for chronic hepatitis C in patients undergoing long-term haemodialysis. Results: Sustained virological response was obtained in eleven (42%) patients. Seven (26.9%) patients interrupted prematurely the antiviral treatment due to serious side-effects, the most frequent cause of treatment withdrawal being hematological (n=3). HCV RNA load was lower in responder than non-responder patients, 5.44 (3.45; 6.36) vs. 5.86 (4.61; 6.46) log10 copies/mL, even if the difference was not significant (P=0.099). Blood transfusion requirement was greater in patients on combined antiviral therapy than those on pegylated interferon alone, 100% (5/5) vs. 0% (0/21), P=0.0001. No difference in sustained viral response occurred between patients on combined antiviral therapy and those on pegylated interferon monotherapy [40% (2/5) vs. 42.8% (9/21), P=0.90]. Conclusions: Results from this study showed that pegylated interferon alone or with ribavirin is unsatisfactory in terms of efficacy and safety. Prospective trials based on interferon-free regimens (i.e., sofosbuvir plus ribavirin or sofosbuvir plus daclatasvir) are under way in patients with hepatitis C receiving long-term hemodialysis.

Affinity chromatography represents a sole technique in purification of different biomolecules. The specific recognition between affinity ligands and target biomolecules has a major role in the specificity of the process. Therefore, choosing the right ligand is a crucial step for the development of a successful purification system. This work describes the application of the DNA intercalator 3,8-diamino-6-phenylphenanthridine (DAPP) as a chromatographic affinity ligand for the specific separation and purification of supercoiled plasmid DNA (pDNA). The support was prepared by coupling DAPP onto an epoxy-activated Sepharose matrix, using mild conditions and resulting in a ligand density of 0.15 mmol DAPP/g derivatized Sepharose. The characterization of DAPP-Sepharose support in terms of dynamic binding capacity was achieved by studying the effect of plasmid DNA concentration and flow rate on pDNA adsorption. The maximum capacity value of 336.75 μg pDNA/mL gel was obtained at 1 mL/min with a pDNA concentration of 150 μg/mL. Moreover, the values did not vary significantly with the variation of flow rate. In addition, the DAPP-Sepharose showed a high affinity towards pDNA as quantified by the respective dissociation constant (Kd = 2.29 ± 0.195 × 10−7 M). The support was also tested for the purification of two plasmid molecules with different sizes (pVAX1-LacZ and pCAMBIA-1303, with 6.05 kbp and 12.361 kbp, respectively) from clarified Escherichia coli lysate solutions. Total retention of all lysate components was achieved without any added salt to the eluent buffer. The selective elution of impurities and supercoiled pDNA was accomplished simply by the addition of small amounts of salt to the buffer solution. The yield for pCAMBIA-1303 was 65% and for pVAX1-LacZ was 94%, with all host impurity levels in accordance with the requirements established by the regulatory agencies.

AG490 is a tyrphostin originally described as a Janus Activated Kinase (JAK) 2 inhibitor. AG490 also inhibits epidermal growth factor receptor (EGFR) and guanylyl cyclases (GC). More recently, AG490 was associated with oxidative stress protection in experimental acute kidney injury models. We now show that AG490 is also a strong activator of the Hypoxia Inducible Factor (HIF)-1. Under normoxic conditions HIF-1α is degraded through hydroxylation, von Hippel Lindau protein (VHL)-mediated ubiquitin tagging and proteasomal degradation. AG490 increased HIF-1α protein, but not HIF-1α mRNA levels, dose- and time-dependently in cultured endothelial, vascular smooth muscle and kidney proximal tubular epithelial cells. AG490 increased HIF-1α protein half-life, suggesting that HIF-1α protein accumulation resulted from a decreased degradation. In this regard, AG490 prevented HIF-1α hydroxylation and increased HIF-1α protein levels in human renal carcinoma cells expressing VHL, but did not further increase HIF-1α in VHL negative cells. AG490 did not prevent the proteasomal degradation of other proteins. HIF-1α was not upregulated by dominant negative JAK2constructs, tyrphostin AG9, the EGFR inhibitors erbstatin and genistein, the GC inhibitor Ly83583 or cGMP analogues. Finally, AG490 also increased HIF-1α transcriptional activity evidenced by the increased HIF-1α-dependent VEGF expression. In conclusion, AG490 is a novel HIF-1α activator that increases HIF-1α half-life and protein levels through interference with HIF-1α hydroxylation and VHL-mediated degradation. This action may contribute to the cell and tissue protective effects of AG490.

Purpose Cholesterol microembolization may explain some treatment failures after renal artery stent placement. The identification of cholesterol crystals may provide significant help in diagnosing the real frequency and severity of this complication. The aim of the present study was to examine the efficacy of polarized light imaging in the detection of cholesterol emboli trapped in a protection device. Materials and Methods During a period of 18 months, 15 significant atherosclerotic stenoses of the ostium of the main renal artery were treated with primary stent placement with embolic protection. The filter device used was made of polyurethane, with a pore size of 115 μm. The device was mounted over a 0.014-inch guide wire. For pathologic analysis, the recaptured filter basket was compressed between two slides and examined in a microscope under polarized light. Results All the stenoses were successfully treated without clinical complications. All the filters were deployed and recaptured without difficulty. Cholesterol crystals were detected in 12 filters and no cholesterol was found in three. In one case, trouble with filter manipulation precluded pathologic analysis. No worsening of renal function was detected in any patient during follow-up. Conclusions Microscopic analysis with polarized light easily detects the cholesterol crystals trapped in the filter device. This provides evidence that renal cholesterol microembolism is highly prevalent during renal artery stent placement.

Introduction and objectives. Physiological and hypotonic saline solutions have been used interchangeably for preventing contrast media nephrotoxicity. No analysis of the possible differential effects of the 2 solutions on the milieu interieur or intercompartmental fluid volumes has been performed. Our aim was to study the systemic and renal effects of 2 types of saline solution regularly used to prevent contrast media nephrotoxicity in patients undergoing coronary angiography. Methods. Changes in electrolyte levels and volume distribution were studied in 71 individuals who were randomized to receive either 0.9% isotonic saline (n=36) or 0.45% hypotonic saline (n=35) during the 12 hours before and after contrast injection (2000 mL in each period). Results. The creatinine level was elevated equally often in the isotonic and hypotonic saline groups. Isotonic saline administration led to reductions in hemoglobin level, hematocrit, and plasma albumin level, and to increases in plasma volume, by 12.3% and 10.4% at 24 and 48 hours, respectively. These changes were significant compared with baseline measurements and compared with the group that received hypotonic saline. Neither of the 2 saline solutions resulted in a change in plasma atrial natriuretic peptide level. Plasma and urine osmolality decreased only with hypotonic saline. The increase in plasma creatinine level was similar with both isotonic and hypotonic saline. Conclusions. During standard therapy for preventing contrast media nephrotoxicity: a) isotonic saline, but not

Aunque la anemia ha pasado a ocupar un plano relevante en la concepcion patogenica actual de la insuficiencia cardiaca (IC), se trata aun de una entidad rodeada de incognitas. La prevalencia de anemia y su importancia clinica en la poblacion con IC son muy elevadas. Sin embargo, no se han establecido aun con certeza suficiente los objetivos de tratamiento de la anemia en la poblacion con IC. El presente trabajo revisa aspectos clinicos y fisiopatologicos de esta forma particular de anemia, con especial atencion a los mecanismos celulares y moleculares de regulacion, y sus implicaciones en el tratamiento.

Several studies have documented the nephroprotective effect of cilastatin co-administered with imipenem in subjects treated with cyclosporin A. However, no large clinical studies are available to confirm this observation. Here the quality of the evidence on cilastatin nephroprotection against cyclosporin-induced nephrotoxicity is evaluated.The results of all studies where cyclosporin was used alone or combined with imipenem/cilastatin (Tienam) on the same clinical setting were systematically reviewed. Primary outcome was the reduction in serum creatinine concentration. Secondary outcome included development of acute renal failure. Medline was searched using three different retrieval systems (Pubmed, Silver Platter, Knowledge Finder) from January 1966 to February 2006. Attempts were made to contact authors of relevant studies to obtain additional data. Five clinical studies were found, including 125 patients under cyclosporin plus imipenem/cilastatin and 104 under cyclosporin alone.Cyclosporin increased serum creatinine in all the studies. Average reduction of serum creatinine in cilastatin-treated versus untreated patients was Delta = -0.53 mg/dL (95%CI: -0.90 to -0.17) (Z = 2.84, p = 0.004). Variability between studies was large (from Delta = -0.21 to Delta= -1.59 mg/dL) and heterogeneity pronounced (chi(2) = 8.760, df = 4; p = 0.067). Meta-regression of serum creatinine reduction versus baseline serum creatinine explained 84% of this variability, by the variation in basal serum creatinine. When randomized and observational clinical studies were analyzed separately, conclusions were the same: serum creatinine in cilastatin treated patients was reduced by Delta = -0.98 mg/dL (95%CI: -1.57 to -0.38) in randomized studies (Z = 3.213, p = 0.001) and Delta= -0.32 mg/dL (95%CI: -0.63 to -0.01) in observational studies (Z = 2.013, p = 0.044). Odds Ratio for developing acute renal failure was 0.24 (95% CI: 0.11-0.53, p0.0001) on patients simultaneously treated with cyclosporin plus imipenem/cilastatin compared to patients treated with cyclosporin alone.Administration of cilastatin may reduce acute cyclosporin nephrotoxicity.

Although anemia now occupies an important place in our present understanding of the pathogenesis of heart failure, the condition is surrounded in mystery. Anemia is highly prevalent in patients with heart failure and is of great clinical significance. However, the treatment targets for anemia in patients with heart failure have still not been accurately defined. The present article reviews of the clinical and pathophysiological characteristics of anemia in this context. Particular emphasis has been placed on cellular and molecular regulatory mechanisms, and their implications for treatment.

Lately, researchers have made several efforts to improve vaccine production to fight highly contagious respiratory diseases like influenza. One of the most promising options for reducing the impact of this virus is DNA vaccination. However, a large quantity of highly pure plasmid DNA (pDNA) is necessary to attain this goal. The present work describes the production and purification of the plasmid NTC7482-41H-VA2HA expressing influenza virus hemagglutinin using an agmatine monolith. This ligand was chosen to purify supercoiled (sc) pDNA from complex lysates because of its versatile multimodal character. Its natural intervention in several biological systems together with its similarity with the highly studied arginine ligand allowed the development of a simpler and more specific purification process. Agmatine works under two strategies: descending ammonium sulfate gradient and ascending sodium chloride gradient. Furthermore, pH manipulation revealed an important role in pDNA isoforms selectivity. Dynamic binding capacity (DBC) experiments were performed varying different parameters and showed an increase with pDNA concentration, while high flow rate and high pH had the opposite effect. Sc pDNA was purified with high yield and was efficient with respect to cell transfection and cell viability. This monolith showed to be appropriate to purify the plasmid NTC7482-41H-VA2HA, providing a valuable tool for pDNA influenza vaccines preparation.

La enfermedad cardiovascular es la primera causa de morbimortalidad en Espana. La presencia de insuficiencia renal tiene un valor pronostico y obliga a modificar el abordaje terapeutico. Identificamos con el termino de insuficiencia combinada cardiorrenal (ICR) a una entidad diferenciada, infraestimada en nuestra poblacion, en la que coexisten el fallo renal y el cardiaco. Los pacientes con ICR son autenticos supervivientes de la aplicacion de diversas tecnologias y po-seen un equilibrio hemodinamico e hidrosalino diferente del de las insuficiencias cardiaca o renal aisladas. El diagnostico temprano de esta enfermedad, su seguimiento, tanto hospitalario como ambulatorio, asi como un manejo especifico, condicionan su pronostico. El aspecto clave del control de estos enfermos reside en el mantenimiento de un delicado balance de liquidos, que es siempre individual y personalizado. Este tipo de manejo requiere un entrenamiento y mentalizacion particulares del personal sanitario, con una vision integrada de los multiples factores implicados. El diseno de un plan estructurado segun objetivos, y la comprension del equilibrio de cada individuo son una pieza clave del tratamiento de la ICR. La presente revision se basa en conceptos tradicionales, actualizados de una manera practica, y trata de llamar la atencion sobre una entidad clinica en acelerado crecimiento.

Recurrent acute postinfectious glomerulonephritis is infrequent in childhood and exceptional in adults. The factors that determine recurrence are poorly understood. Selective IgA deficiency is characterized by an increased incidence of gastrointestinal and respiratory infections. The case of a 33-year-old man with a history of repetitive sinopulmonary infections and diagnosed with selective IgA deficiency is described. He suffered 2 episodes of postinfectious glomerulonephritis within a 15-year period. Selective IgA deficiency may have predisposed to the development of recurrent postinfectious glomerulonephritis

The present study, reports the utilization of berenil as ligand in a negative pseudo-affinity chromatographic step to purify the plasmid pVAX1-LacZ from Escherichia coli clarified lysates. The chromatographic support was prepared by coupling berenil to epoxy-activated Sepharose and was qualitatively and quantitatively characterized using scanning electron microscopy, Fourier transformed infrared spectroscopy and elemental analysis. The clarified lysate was loaded onto the berenil-Sepharose support with 0.55 M of ammonium sulphate in the eluent, achieving the immediate elution of plasmid DNA. The impurities tightly bound to the support, were eluted after decreasing the salt concentration to 0 M. The overall process enabled the recovery of 87% of loaded plasmid DNA with a HPLC purity of ≫99% and according to FDA specifications. This method represents an alternative approach to the previous utilization of the same chromatographic pseudo-affinity support in a positive mode. It uses lower amounts of salt and one-step chromatographic procedure, resulting in smaller operating time and costs and representing an alternate procedure for plasmid DNA purification.

The present study addressed the effect of interventions aimed to increase NO in the setting of acute renal ischemia/reperfusion (I/R) in uninephrectomized rabbits. In the 60-minute post-I/R period, l -arginine+superoxide (O 2 •− ) dismutase (SOD) synergistically improved the renal functional (69.4% versus 10.4% of the pre-I/R glomerular filtration rate with or without l -arginine+SOD, respectively; P l -arginine+SOD, P l -arginine+SOD was no longer present at 24 and 48 hours (plasma creatinine in vehicle-treated versus l -arginine+SOD–treated animals [mg/100 mL]: 24 hours after I/R, 9.4±1.9 versus 8.07±0.65; 48 hours after I/R, 11.6±3.6 versus 9.7±0.9; P =NS in all the cases). Additional experiments were conducted using a milder 30-minute ischemic model, which showed no significant functional or histological protection by using l -arginine+SOD. In conclusion, our experiments disclosed the following: (1) the critical importance of the interaction between NO and O 2 •− in the acute protective effect of l -arginine (this effect not only improved renal function and histology but also reduced neutrophil accumulation) and (2) the discordance existing between the immediate protection afforded by l -arginine+SOD and the lack of protection observed at 24 and 48 hours. This finding suggests that a punctual intervention on the NO system at the time of I/R is not sufficient to reduce renal damage over the long term.

Small molecules that bind DNA with high specificity present a promising opportunity for application as chromatographic ligands for plasmid DNA (pDNA) purification. This research used the intercalator 3,8-diamino-6-phenylphenanthridine (DAPP) as an immobilized ligand for the specific separation of supercoiled (sc) pDNA by affinity chromatography. The results showed that the protonated DAPP-Sepharose support has a great affinity for sc pDNA isoform, separating it from the less active open circular and linear isoforms. All pDNA isoforms were retained in the column using 10mM acetate buffer pH 5. Selective elution of oc and linear isoforms was achieved with 0.22M of sodium chloride in the same buffer. Finally, increasing the concentration to 0.55M led to the elution of the sc isoform. The binding of pDNA to DAPP-Sepharose varies in function of pH, and the stability of the protonated DAPP-DNA complex decreases with increasing salt concentration.

In this study, berenil was tested as a ligand, specifically to purify plasmids of different sizes pVAX1-LacZ (6.05 Kbp) and pCAMBIA-1303 (12.361 Kbp) from clarified Escherichia coli alkaline lysates. For this purpose, chromatographic experiments were performed using Sepharose derivatized with berenil. The results showed that both pDNA molecules are completely purified using lower amounts of salt in the eluent than those previously reported for other pseudo-affinity and hydrophobic interaction chromatography based processes. Total retention of all lysate components was achieved with 1.3 M ammonium sulphate in the eluent buffer and pDNA elution was obtained by decreasing the salt concentration to 0.55 M. All impurities were eluted after decreasing the concentration to 0 M. The recovery yield for pCAMBIA-1303 (45%) was lower than that obtained for pVAX1-LacZ (85%), however the larger pDNA showed a higher purity level. Purification of pVAX1-LacZ was also performed using non-clarified E. coli process streams, replacing the clarification step with a second chromatographic run on the berenil-Sepharose. Using the same binding and elution conditions as before, a pure plasmid sample was obtained with a 33% yield and with all host impurity levels in accordance with the requirements established by the regulatory agencies. These results suggest that this chromatographic method is a promising alternative to purify pDNA for therapeutic use., Fundação para a Ciência e Tecnologia (FCT) - PTDC/QUI-QUI/100896/2008, SFRH/BD/64918/2009

To determine the role of nitric oxide (NO)-dependent mechanisms on erythrocyte properties, we exposed red cells to L-arginine competitive analogues, 8Br-cyclic guanosine monophosphate (8Br-cGMP) and neutrophil-eliminating filters. These treatments significantly decreased hypotonic hemolysis, increased potassium efflux and caused a spiculate change in erythrocyte morphology. These effects were related to a decrease of NO caused by the three types of treatments.

Cyclosporin A (CyA) is an efficient immunosuppressive agent, which, however, causes functional and structural alterations in endothelial cells. The aim of the present study was to examine the mechanisms of CyA-induced endothelial disfunction. CyA administration (Wistar rats, 25 mg/kg per day for 15 days) induced a significant inhibition of endothelium-dependent relaxation to acetylcholine on isolated femoral arteries. No changes with CyA were detected in the relaxation response to the endothelium-independent agent (sodium nitroprusside) or the endothelium-dependent receptor-independent agent (Ca2+ ionophore). The addition of L-arginine (10(-5) mol/L) shifted to the left the acetylcholine-mediated vasorelaxing response in CyA-treated segments, an effect that was accompanied by a marked increase of cGMP. 45Ca2+ uptake was higher in CyA-treated segments with respect to control segments but became normalized after incubation with L-arginine or sodium nitroprusside. De-endothelialization or incubation with the L-arginine competitive analogue N omega-nitro-L-arginine (NwNLA) increased 45Ca2+ uptake in control segments but not in CyA-treated segments. In conclusion, in isolated rat arteries, chronic CyA therapy affects endothelial function by uncoupling the acetylcholine-mediated relaxation and interfering with an endothelium-mediated pathway that regulates 45Ca2+ uptake by a mechanism reversed by an L-arginine-dependent cGMP generation.

We have studied the levels of a new biochemical marker of bone resorption, carboxyterminal cross-linked telopeptide of type I collagen (ICTP), in 26 healthy control subjects, 15 patients with primary hyperparathyroidism (PHPT) and 17 patients with secondary hyperparathyroidism (secondary HPT). Levels of ICTP in PHPT and secondary HPT have been correlated with those of serum tartrate resistant acid phosphatase (TRAP), another biochemical marker of bone turnover, and with serum levels of intact parathyroid hormone (iPTH). The ICTP levels of the control group were 2.07 +/- 0.58 micrograms l-1, n = 26, range 1.3-3.2. They were independent of sex and age in the studied age range (30-62 years). The ICTP levels of PHPT patients were 3.5 +/- 3.5 micrograms l-1, mean +/- SD, range 0.5-12.2 micrograms l-1, significantly higher than those of control subjects (p0.05). We found a significant linear correlation between values of ICTP and iPTH levels (p0.01), between values of ICTP and serum activity of TRAP (p0.01) and between iPTH and TRAP levels (p0.01) in patients with PHPT. The ICTP levels in patients with secondary HPT were higher than those of patients with PHPT, 46 +/- 37 micrograms l-1, range 12-167 micrograms l-1 (p0.001) due to the impaired renal clearance of this peptide. We did not find a significant linear correlation between values of ICTP and iPTH levels in the serum of patients with secondary HPT, although we found a significant correlation between levels of ICTP and levels of TRAP, both biochemical markers of bone turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Small molecules, like some antibiotics and anticancer agents that bind DNA with high specificity can represent a relevant alternative as ligands in affinity processes for plasmid DNA (pDNA) purification. In the present study, pDNA binding affinities of berberine, berenil, kanamycin and neomycin were evaluated by a competitive displacement assay with ethidium bromide using a fluorimetric titration technique. The binding between pDNA and ethidium bromide was tested in different buffer conditions varying the type and the salt concentration, and was performed both in absence and in presence of the studied compounds. The results showed that the minor groove binder berenil has the higher pDNA binding constant. Chromatographic experiments using a derivatized column with berenil as ligand, showed a total retention of pDNA using 1.3 M ammonium sulphate in eluent buffer. A selective separation of supercoiled and open circular isoforms was achieved by further decreasing salt concentration to 0.6 M and then to 0 M. These results suggest a promising application of berenil as ligand for specific pDNA supercoiled (sc) isoform purification by pseudo-affinity chromatography., C. Caramelo-Nunes acknowledges a fellowship (SFRH/BD/64918/2009) from the Portuguese Foundation for Science and Technology (FCT).

The effect of endothelin (ET) on the cytosolic-free calcium [(Ca2+]i) changes in polymorphonuclear leukocytes (PMN) from normal humans and Wistar rats was investigated. ET induced a dose-related [Ca2+]i peak. This [Ca2+]i transient was blunted by TMB-8 (10(-5)M) and by Ca(2+)-free EGTA medium, therefore suggesting a role of both intracellular Ca2+ release and Ca2+ influx in the generation of the [Ca2+]i peak. Preincubation of PMN with the nitric oxide (NO)-donor L-arginine (L-Arg) markedly blocked the ET-induced [Ca2+]i transient in an enantiomerically-specific manner. A similar blunting effect of L-Arg on the fMLP (10(-7)M)-induced [Ca2+]i transient was detected. The L-Arg antagonist, NG-monomethyl-L-arginine (L-NMMA), reverted the L-Arg blocking effect on both ET- and fMLP-induced [Ca2+]i transients. These data suggest that ET has a potential role in activating Ca2+ mobilization in PMN, an effect that can be inhibited by L-Arg.

Leishmania infection may be associated with immunecomplex-mediated glomerular injury. Contrary to immune-competent individuals, leishmaniasis in HIV patients is a chronic, relapsing disease. Despite the increasing frequency of the Leishmania/ HIV co-infection, there is a paucity of information on the effects of such co-infection in the kidney. We present a patient with AIDS and refractory, relapsing visceral leishmaniasis who developed nephrotic syndrome associated with renal involvement by Leishmania in the absence ofimmunecomplex glomerular deposition. For the first time, the relapsing nature of renal injury in this context is documented.

Intravenous fluids administration is the usual practice in the postoperative period. Nonetheless, consensus about the more appropriate fluid reposition recipe is still insufficient.To study the type of intravenous reposition used in Surgical Units and its impact on the internal milieu.prospective study of 112 patients with scheduled surgery, receiving only intravenous fluids.biochemical study on postoperative fluids management in uncomplicated surgery. Principal variables: 1. Water and electrolytes administrated. 2. Differences in sodium/water balances before surgery vs first day after surgery. 3. Symptoms related to hyponatremia.Median P[Na] before and after surgery was 139.9+/-2.9 and 137.7+/-3.7, respectively (p0.01). Fourteen patients (12.5%) had P[Na]135, and 12 of them had a reduction of more than 6 mmol/L; accordingly, twenty-six patients (23.2%) had an increased free-water retention (p0.05). Relevantly, they did not receive a higher amount of free-water and the proportion of isotonic saline/free water varied from1 to3. As possible mechanism of free-water accumulation: the postoperative P[Na] was lower in the patients who had a negative free-water clearanceor= -1 L (136.7+/-4.1 vs 138.5+/-3.2 mmol/L, p 0.015).The present study provides new information about the intravenous fluids prescribed in postoperative patients, ie, different proportions saline/water are basically equivalent with respect to inducing symptomatic hyponatremia. The mean value of the relation saline/water is 2:1. Hypotonic fluids input is not clearly related to more intense hyponatremia; the latter appears to depend more on a reduced capacity of the kidney to generate sufficient free water output.

Treatment of mycotic aneurysms of the aorta includes excision of infected tissue followed by anatomic or extra-anatomic bypass. However, operative mortality remains high particularly in elderly patients with comorbidities. We describe here 2 patients with mycotic aneurysms of the descending aorta in whom endovascular repair was successfully performed. In 1 of these patients, stent grafting was attained during the acute, bacteraemic phase of infection. After 12 and 20 months, respectively, of diagnosis, both patients are doing well.

Vasculitis is diagnosed with increasing frequency in the elderly. We hereby present the case of an 84-year-old male, who had weight loss, low-degree fever, anemia and epigastric pain. After 14 days of study with the tentative diagnosis of digestive neoplasia, a progressive renal insufficiency was detected. This clinical picture was secondary to ANCA-positive vasculitis. The case poses the differential diagnosis of non-oliguric acute renal failure (FRA) in elder people and the systematics of the study of renal insufficiency in individuals with previously unknown renal function. Also, this patient's history emphasizes the importance of acute deterioration of renal function as a guiding symptom for orienting the interpretation of clinical data. In the present case, a diagnostic hypothesis based only in the pursue of an occult digestive tumor misguided the attention from the main cause of the disease.

The viric infections influence morbi-mortality in Chronic kidney Disease patients in hemodialysis therapy and can affect to the Staff of the Units. The guides considered the most relevant virus at the present moment: C Virus, B Virus and HIV. To prevent horizontal nosocomial transmission is necessary the observance always the universal precautions in the HD units, although sometimes can appeared seroconversions and epidemic bud when exist a break of these. Is analyzed different situations with special focus in units for acute patients. The following steps under the suspicious of the epidemic bud appeared in one of the annexes together with legislation according to this case. Respect to the staff in every one of the virus is shown prevention patterns, serologic markers to perform when an accident with infected blood occur, also is considered when treatment is indicated. The guides considered too the conditions necessary for include these patients on waiting list for kidney transplantation.

The aim of the present study was to investigate the effect of different dialysate buffer and glucose concentrations, membrane surface (S) bigger than 2 m2 and increased dialysate flow (Qd) in phosphate (P) removal.A. First phase (5 patients): the following variations in dialysate composition were introduced. A: glucose 1.60 g/L, bicarbonate: 39 mEq/L, acetate 4 mEq/L, B: glucose 1.5 g/L bicarbonate 17 mEq/L, acetate 10 mEq/L; C: glucose 0, bicarbonate: 39 mEq/L, acetate 4 mEq/L; and D: glucose 0, bicarbonate 17 mEq/L, acetate 10 mEq/L. B. Second phase (14 patients): variations in S and Qd were: 1. Qd: 500 mL/min + Hemophan 2 m2, 2. Qd: 500 mL/min + Hemophan 2.6 m2, 3. Qd: 750 mL/min + Hemophan 2 m2, 4. Qd: 750 mL/min + Hemophan 2.6 m2.Comparing HDs performed with low bicarbonate (B and D) respect to current buffer formulations (A and C), total P removal was 997.3 (+/- 237.3) vs 882 (+/- 216.1) mg (p NS). No differences were found by grouping the sessions according to glucose concentration. There were no significant differences in total phosphate removal between the two different S or Qd. The most important predictive factor of total P removal was the initial P and 2 hours serum P concentration, and PTH concentration.i) Removal of P is better predicted by pre-dialysis P serum concentration; ii) P removal was not affected by the changes in bicarbonate and glucose concentration in the dialysate; iii) the increase of the dialyzer area between 2 and 2.6 m2 augments Kt/V, but without influencing P elimination; iv) a higher Qd does not determine significant differences in P removal and v) higher PTH is associated with a higher P elimination.

When a pyoverdin (PV), (a siderophore) from Pseudomonas fluorescens , binds aluminum 1:1, its natural fluorescence almost doubles, whereas PV–Fe is non-fluorescent. Complex formation allows [Al] determination down to 1 μg/l. Fe(III) in the sample interferes with [Al] determination, but added after PV, improves the assay’s performance. Ascorbic acid does not eliminate Fe(III) interference. PV–Al fluorescence could have analytical and toxicological applications.

Hypophosphatemia (Hf) is infrequently reported in chronic hemodialysis patients. The objective of this report is to describe the incidence, etiology, symptoms and treatment of Hf in a Dialysis Unit (defined as phosphorus2.5 mg/dL). In a retrospective study over a period of three years, we identified 22 cases of Hf, occurring on 11 among 149 patients. A two-groups distribution was made: Group A, patients with more than one episode (n = 3, 14 episodes of Hf) and Group B, patients with only one isolated episode of Hf (n = 8, 8 episodes of Hf). Plasma Ca, P, Albumin and nPCR were significant lower in group A (p0.05). Only two patients of group B had symptoms. Cases of Hf were: Group A: low-protein diet and alcoholism, Group B: decreased dietary intake due to non-digestive problems (n = 2) or due to digestive problems plus antacids (n = 4), phos-phate binders (n = 1) and dietary phosphorus restriction (n = 1). Three patients had secondary hyperparathyroidism. Treatment consisted on oral supplementarion by diet and changes in oral calcium salts. Intravenous supplementation was required acutely to raise serum P in a patient with auricular fibrilation. Two group A patients who has plasma 1.25 vitamin D5 pg/mL received vitamin D, and the third oral supplements of P. In all the cases, Hf resolved with these measures. We concluded that Hf is not so infrequent in hemodialysis. In patients with low-protein diet and low vitamin D concentration, Hf can be sustained. On the other hand, a decreased dietary intake maintaining similar phosphate binder's supplementation is the most frequent cause of occasional and symptomatic Hf, even in patients with secondary hyperparathyroidism.

The relationship between estrogens, bone metabolism and osteoporosis is well known. Chronic renal failure in women is associated with menstrual disorders, lower bone mineral density and increased risk of fractures. However, most studies on renal osteodystrophy have not taken into account the role of oestrogen deficiency, its interaction, and the possible benefits of hormone replacement therapy (HRT) in uremic women. According to these limitations and the actual evidence of benefits and risks of HRT, we conclude that: a) Osteoporosis must be evaluated as a part of renal osteodystrophy; b) HRT would be considered in women with climateric symptoms and osteoporosis, and should not be used for prevention of cardiovascular disease, and c) Clearly we need to do more studies related to osteoporosis and estrogens in CRF, but right now we have to try to optimize bone turnover in our uremic patients.

It has been recently proposed that haemodialysis membrane choice may influence the maintenance of residual renal function. The aim of the present study was to prospectively analyse the effect of membrane choice on the outcome of renal function in patients entering a chronic haemodialysis programme. Twenty-two patients from four hospitals have been randomly assigned to be dialysed with either polysulphone (PSF)/polyacrylonitrile (PAN) (group A; n = 9), or cuprophane membranes (group B; n = 13). Basal and monthly serum biochemistry, residual creatinine clearance (Ccr) and urine volume (Vu), pharmacological and dialytic treatment, diet, and haemodialysis-related complications were recorded. A significant decrease was observed in the two most relevant variables, i.e. remnant Ccr and Vu, within 3 months of starting haemodialysis, with stabilization during the further follow-up. Such decrease was similar (P NS) for both groups A and B throughout the 9-month observation period. In conclusion, our results suggest that the choice of haemodialysis membrane does not influence the outcome of the residual renal function. Renal function decreased significantly within 3 months on haemodialysis, independently of the type of dialyser membrane.

In the present work, we have examined the effects of selective inhibition of the inducible isoform of nitric oxide synthase (iNOS) in rat medulla by aminoguanidine (AG) on the arterial pressure of Dahl salt sensitive (DS), Dahl salt-resistant (DR) and Sprague Dawley (SD) rats by chronic in vivo hemodynamic experiment, the effect of sodium chloride (NaCl) or NaCl plus AG infusion on urinary nitrate/nitrite (urinary NO3/NO2 UNO(x)), the end product of nitric oxide (NO), excretion, glomerular filtration rate (GFR), effective renal plasma flow (ERPF) and plasma renin activity (PRA). Furthermore, an iNOS activity assay was also made. The results showed that AG infusion significantly augmented the pressor response of DS and SD rats to high NaCl (8%) intake, and decreased GFR, ERPF and PRA of DS rats. In addition, in DS rats, renal medullary interstitial administration of high NaCl significantly elevated the iNOS activity of renal tissue, especially inner medulla and outer medulla, and greatly increased UNO(x) excretion. Therefore, it is concluded that inducible NOS is an important modulator of blood pressure in case of NaCl-induced hypertension.

Tubular secretion of creatinine is increased by meat meals. This increment has been attributed to the formation of new creatinine from creatine contained in the cooked meals. However, no studies are available using amino acid infusions containing no creatine, which allow to further investigate the putative causes of increment in tubular creatinine secretion.We performed a prospective, interventional study involving 34 individuals with normal renal function participating in a protocol on arterial hypertension. A continuous infusion of L-arginine (6%, i.v., in four 30 min periods at 50, 100, 200 and 300 ml/h) was administered. Creatinine (CCr) and inulin (CIn) clearances were determined at baseline and during L-arginine infusion. We analyzed the effects of L-arginine on tubular secretion by comparing CCr and CIn and calculated tubular secretion of creatinine (TSCr).L-arginine infusion induced a significant increase in both CCr and CIn. CCr and CIn were respectively 117.9 +/- 22.7 and 107.5 +/- 23, before and 170.3 +/- 23 and 144.2 +/- 47.8 after the infusion of L-arginine (both p0.01). This increase was simultaneous with an increment in TSCr from 1.12 +/- 0.4 to 1.43 +/- 0.6 (p0.01). CCr correlated significantly with CIn at baseline and at 60 min of infusion (r = 0.365, p = 0.031 and r = 0.368, p = 0.038, respectively), but not at 120 min (r = 0.130, p = 0.412), a time corresponding to the maximum increase in CIn and TSCr.L-arginine induces a substantial increase of CCr, which exceeds that expected from the increase in glomerular filtration rate measured by CIn and corresponds to an increment in TSCr. This phenomenon adds a new interpretation of the effect of amino acids on tubular handling of creatinine and has practical implications in the evaluation of renal function by means of creatinine clearance.

An important number of Hospital admissions (HA) occurs through Hospital Emergency Departments (HED). This is a indicator of quality and have to be lower than 50%. However there are almost no data available on the causes of emergency consultation by outpatient hemodialysis patients (HD). For this reason, we prospectively examined a population of 83 outpatient HD patients dialyzed in a peripheral unit under the surveillance of a University Hospital.1) To know the diagnosis of HED and days of hospitalization for which HD patients came to the HED in 1998. 2) To know the possible risk factors associated with the patients with frequent assistance in HED. 3) To compare the number and causes of emergency consultation in 1998 with a group of patients treated in the same Unit in 1991 (n = 39).The percentage of patients who used the HED in 1998 was 66.3% (55/83). The total number of emergency episodes in 1998 was 118 (mean of 55 patients 2.27 +/- 1.51). Fifty one percent of the emergency episodes were due to patients initiative. The 4 more frequent diagnoses of HED in 1998 were infectious, 19.5% (23/118); traumatologic emergencies, 15.3% (18/118); digestive disease 15.3% (18/118); relationed problem vascular access, 11.9% (14/118). Thirty percent (36/118) of the emergency consultations needed HA leading to a mean hospitalitation of 10.2 +/- 9.3 days. The infectious disease were the highest percentage of HA (36.1%) and the longest days of hospitalitation (12.7 +/- 11.2 days). The risk factors for repeated emergency consultation (more than 3 times) were: age (68.9 vs 61.4), lower hematocrit (31.6 vs 34.4%), lower hemoglobin (10.2 vs 11), high EPO dose (166.3 vs 109.7 unit/kg/week) and lower Kt/V (0.99 vs 1.11). If we compare these results with 1991 the percentage that used the HED was similar 66.2% (pNS); the number of emergency episodes was higher (mean 2.99 +/- 1.96) than 1998 (p0.006) and there are a significant differences in the diagnoses of HED between 1998 and 1991: acute pulmonary edema 1.7 vs 11.2% (p0.003); hiperkalemia 0.8 vs 7.9% (p0.009); gastrointestinal disease 15.3% vs 4.5% (p0.008) and infectious 19.5% vs 7.9% (p0.01). In conclusion our study provides data previously not available on the epidemiology of Emergency Consultation by outpatient HD patients treated in the same peripheral unit. The data obtained albeit limited because of the number provide information of potential protocol usefulness for the possible reduction in the frequency of Hospital Emergency Consultations by outpatient HD patients.

The expression of vascular endothelial growth factor (VEGF) was analysed in biopsy samples from patients with pyogenic granuloma. The results disclosed the presence of a strong VEGF signal in pyogenic granulomas, which are constituted by a vast majority of cells of endothelial lineage. A marked positivity was evident in areas of proliferating endothelial cells without vessel lumen formation. In the same respect, staining for VEGF was less marked in the vessels with a well-developed lumen. The fact that VEGF production appears to be limited to endothelial cell precursors or immature endothelial cells prior to the complete development of the vessels, leads to the possibility that VEGF may act as an autocrine factor in circumstances of endothelial cell stimulation.

Abstract —The mechanisms involved in the blockade of proliferation in confluent endothelial cells are insufficiently understood. In this regard, the continuity of intercellular junctions appears to be critical to the regulation of endothelial monolayer cell growth. The present study examined the hypothesis that the disruption of the intercellular adherens junctions will trigger both endothelial cell proliferation and autocrine production of growth factors. With this purpose, we assessed the changes in growth, death resistance, and expression of vascular endothelial growth factor (VEGF) under conditions of disruption of the intercellular junctions between endothelial cells. Disruption of cell junctions was produced by means of a specific anti–vascular endothelial cadherin monoclonal antibody, EGTA, or cytochalasin D. Our results disclosed that these maneuvers induce an increase in VEGF mRNA production, with transcription of the 121–, 165–, and 189–amino acid isoforms of VEGF. Further evidence of the relationship between endothelial cells monolayer continuity and VEGF protein expression was obtained by the demonstration of an increase in VEGF protein, as determined by Western blot, induced by the aforementioned maneuvers, as well as by immunocytochemical detection of increased VEGF staining in the areas surrounding a mechanical endothelial injury and in endothelial cells at subconfluence. In functional terms, the autocrine expression of VEGF was associated with growth-promoting and cytoprotective effects, as assessed by [ 3 H]thymidine uptake, 51 Cr release, and flow cytometry. In conclusion, our results reveal that disruption of homophilic interendothelial junctions induces VEGF expression. Under these conditions, autocrine VEGF appears to have a relevant role in death inhibition and proliferation of endothelial cells.

Twenty-one cases of septic pulmonary embolism were selected from a series of 76 patients on chronic haemodialysis diagnosed of S. aureus bacteremia. Ninety percent of patients underwent dialysis through an arteriovenous fistula and 10% by means of a prosthetic access. The most common symptoms were fever (100%), pleuritic pain (66%) and productive cough (55%); twenty-four percent of patients had inflammatory signs at vascular accesses. All patients had some symptoms indicative of pulmonary pathology and all of them had positive blood cultures and findings in the chest X-ray. The clinical course was favourable in 100% of cases. Accesses were lost only in the two cases with prosthetic material. The diagnosis was obtained by chest X-ray and blood cultures. Other more sophisticated tests did not improve the diagnostic yielding.