[Effects of dose of erythropoiesis stimulating agents on cardiovascular outcomes, quality of life and costs of haemodialysis. the clinical evaluation of the DOSe of erythropoietins (C.E. DOSE) Trial]. / Effetti della dose degli agenti stimolanti l'eritropoiesi su esiti cardio-cerebrovascolari, qualità di vita e costi in emodialisi.

BACKGROUND: Anaemia is a risk factor for death, adverse cardiovascular outcomes and poor quality of life in patients with chronic kidney disease (CKD). Erythropoietin Stimulating Agents (ESA) are the most used treatment option. In observational studies, higher haemoglobin (Hb) levels (around 11-13 g/dL) are associated with improved survival and quality of life compared to Hb levels around 9-10 g/dL. Randomized studies found that targeting higher Hb levels with ESA causes an increased risk of death, mainly due to adverse cardiovascular outcomes. It is possible that this is mediated by ESA dose rather than haemoglobin concentration, although this hypothesis has never been formally tested. METHODS: We present the protocol of the Clinical Evaluation of the Dose of Erythropoietins (C.E. DOSE) trial, which will assess the benefits and harms of a high versus a low ESA dose therapeutic strategy for the management of anaemia of end stage kidney disease (ESKD). This is a randomized, prospective open label blinded end-point (PROBE) design trial due to enroll 900 haemodialysis patients. Patients will be randomized 1:1 to 4000 UI/week i. v. versus 18000 UI/week i. v. of epoetin alfa, beta or any other epoetin in equivalent doses. The primary outcome of the trial is a composite of cardiovascular events. In addition, quality of life and costs of these two strategies will be assessed. The study has been approved and funded by the Italian Agency of Drugs (Agenzia Italiana del Farmaco (AIFA)) within the 2006 funding plan for independent research on drugs (registered at www.clinicaltrials.gov (NCT00827021)).

[HFR-AEQUILIBRIUM and intradialytic cardiovascular stability: results of the first multicenter study in Lazio]. / HFR-AEQUILIBRIUM e stabilità cardiovascolare intradialitica: risultati del primo studio multi-centrico laziale.

Intradialytic hypotension (IDH) is a still-frequent and poorly-understood complication of haemodialysis. Haemofiltration has recently been shown to reduce the phenomenon of IDH. HFR-Aequilibrium adds to traditional HFR and is, in practice, a variant comprising endogenous re-infusion of haemodiafiltration with dialysate sodium concentration and ultrafiltration rate profiles elaborated by the 'Profiler' plasma sodium biofeedback system, and measurement of plasma sodium via the on-line Natrium sodium sensor.

Increased hexosamine biosynthetic pathway flux dedifferentiates INS-1E cells and murine islets by an extracellular signal-regulated kinase (ERK)1/2-mediated signal transmission pathway.

AIMS/HYPOTHESIS: Beta cell failure is caused by loss of cell mass, mostly by apoptosis, but also by simple dysfunction (decline of glucose-stimulated insulin secretion, downregulation of specific gene expression). Apoptosis and dysfunction are caused, at least in part, by lipoglucotoxicity. The mechanisms implicated are oxidative stress, increase in the hexosamine biosynthetic pathway (HBP) flux and endoplasmic reticulum (ER) stress. Oxidative stress plays a role in glucotoxicity-induced beta cell dedifferentiation, while glucotoxicity-induced ER stress has been mostly linked to beta cell apoptosis. We sought to clarify whether ER stress caused by increased HBP flux participates in a dedifferentiating response of beta cells, in the absence of relevant apoptosis. METHODS: We used INS-1E cells and murine islets. We analysed the unfolded protein response and the expression profile of beta cells by real-time RT-PCR and western blot. The signal transmission pathway elicited by ER stress was investigated by real-time RT-PCR and immunofluorescence. RESULTS: Glucosamine and high glucose induced ER stress, but did not decrease cell viability in INS-1E cells. ER stress caused dedifferentiation of beta cells, as shown by downregulation of beta cell markers and of the transcription factor, pancreatic and duodenal homeobox 1. Glucose-stimulated insulin secretion was inhibited. These effects were prevented by the chemical chaperone, 4-phenyl butyric acid. The extracellular signal-regulated kinase (ERK) signal transmission pathway was implicated, since its inhibition prevented the effects induced by glucosamine and high glucose. CONCLUSIONS/INTERPRETATION: Glucotoxic ER stress dedifferentiates beta cells, in the absence of apoptosis, through a transcriptional response. These effects are mediated by the activation of ERK1/2.

Cell fate following ER stress: just a matter of "quo ante" recovery or death?

The endoplasmic reticulum (ER) is a complex and multifunctional organelle. It is the intracellular compartment of protein folding, a complex task, both facilitated and monitored by ER folding enzymes and molecular chaperones. The ER is also a stress-sensing organelle. It senses stress caused by disequilibrium between ER load and folding capacity and responds by activating signal transduction pathways, known as unfolded protein response (UPR). Three major classes of transducer are known, inositol-requiring protein-1 (IRE1), activating transcription factor-6 (ATF6), and protein kinase RNA (PKR)-like endoplasmic reticulum kinase (PERK), which sense with their endoluminal domain the state of protein folding, although the exact mechanism(s) involved is not entirely clear. Depending on whether the homeostatic response of the UPR is successful in restoring an equilibrium between ER load and protein folding or not, the two possible outcomes of the UPR so far considered have been life or death. Indeed, recent efforts have been devoted to understand the life/death switch mechanisms. However, recent data suggest that what appears to be a pure binary decision may in fact be more complex, and survival may be achieved at the expenses of luxury cell functions, such as expression of differentiation genes.

Two sunflower 17.6HSP genes, arranged in tandem and highly homologous, are induced differently by various elicitors.

Plants respond to environmental stimuli, such as heat shock, by re-programming cellular activity through differential gene expression, mainly controlled at the transcription level. The current study refers to two sunflower small heat shock protein (sHSP) genes arranged in tandem in head-to-head orientation and linked by a 3809 bp region. These genes exhibit only slight structural differences in the coding portion. They code for cytosolic class I sHSPs and are named HaHSP17.6a and HaHSP17.6b according to the molecular weight of the putative proteins. The genomic organization of these genes is consistent with the idea that many HSP genes originate from duplication events; in this case, probably an inversion and duplication occurred. The HaHSP17.6a and HaHSP17.6b genes are characterized by different expression levels under various heat stress conditions; moreover, their expression is differently induced by various elicitors. The differential regulation observed for HaHSP17.6a and HaHSP17.6b genes differs from previous observations on duplicated sHSP genes in plants.

Cis and trans actions of the cholinesterase-like domain within the thyroglobulin dimer.

Thyroglobulin (Tg, precursor for thyroid hormone synthesis) is a large secreted glycoprotein composed of upstream regions I-II-III, followed by the approximately 570 residue cholinesterase-like (ChEL) domain. ChEL has two identified functions: 1) homodimerization, and 2) binding to I-II-III that facilitates I-II-III oxidative maturation required for intracellular protein transport. Like its homologs in the acetylcholinesterase (AChE) family, ChEL possesses two carboxyl-terminal alpha-helices. We find that a Tg-AChE chimera (swapping AChE in place of ChEL) allows for dimerization with monomeric AChE, proving exposure of the carboxyl-terminal helices within the larger context of Tg. Further, we establish that perturbing trans-helical interaction blocks homodimerization of the Tg ChEL domain. Additionally, ChEL can associate with neuroligins (a related family of cholinesterase-like proteins), demonstrating potential for Tg cross-dimerization between non-identical partners. Indeed, when mutant rdw-Tg (Tg-G2298R, defective for protein secretion) is co-expressed with wild-type Tg, the two proteins cross-dimerize and secretion of rdw-Tg is partially restored. Moreover, we find that AChE and soluble neuroligins also can bind to the upstream Tg regions I-II-III; however, they cannot rescue secretion, because they cannot facilitate oxidative maturation of I-II-III. These data suggest that specific properties of distinct Tg ChEL mutants may result in distinct patterns of Tg monomer folding, cross-dimerization with wild-type Tg, and variable secretion behavior in heterozygous patients.

Mixed-disulfide folding intermediates between thyroglobulin and endoplasmic reticulum resident oxidoreductases ERp57 and protein disulfide isomerase.

We present the first identification of transient folding intermediates of endogenous thyroglobulin (Tg; a large homodimeric secretory glycoprotein of thyrocytes), which include mixed disulfides with endogenous oxidoreductases servicing Tg folding needs. Formation of disulfide-linked Tg adducts with endoplasmic reticulum (ER) oxidoreductases begins cotranslationally. Inhibition of ER glucosidase activity blocked formation of a subgroup of Tg adducts containing ERp57 while causing increased Tg adduct formation with protein disulfide isomerase (PDI), delayed adduct resolution, perturbed oxidative folding of Tg monomers, impaired Tg dimerization, increased Tg association with BiP/GRP78 and GRP94, activation of the unfolded protein response, increased ER-associated degradation of a subpopulation of Tg, partial Tg escape from ER quality control with increased secretion of free monomers, and decreased overall Tg secretion. These data point towards mixed disulfides with the ERp57 oxidoreductase in conjunction with calreticulin/calnexin chaperones acting as normal early Tg folding intermediates that can be "substituted" by PDI adducts only at the expense of lower folding efficiency with resultant ER stress.

Isolation and characterisation of a cDNA for a novel small HSP from sunflower suspension cell cultures.

A full-length cDNA encoding a novel small heat shock protein (HaHSP17.9) was isolated from a cDNA library of sunflower (Helianthus annuus cv. Gloriasol). The deduced amino acid sequence exhibited high degree homology to the class I cytosolic sHSPs from other plant species, and contained all the conserved regions characteristic of this class of proteins. Northern analyses showed that the transcript homologous to HaHSP17.9 accumulates during heat shock in suspension cultured cells and in the different parts of sunflower seedlings.

Irreversible acute renal failure after bilateral extracorporeal shock wave lithotripsy.

A 75 year-old man underwent double extracorporeal shock wave lithotripsy (ESWL) for bilateral nephrolithiasis. After the first treatment, serum creatinine rose to 247.52 mcmol/L. After the second treatment the patient presented persistent gross hematuria and, a few weeks later, oliguric renal failure; serum creatinine rose to 884 mcmol/L. Diagnostic evaluation with ultrasound revealed no obstructive complications, and no subcapsular or perirenal hematoma. The patient started chronic hemodialysis.

[A comparison between propafenone and amiodarone in the conversion to sinus rhythm of atrial fibrillation of recent onset]. / Confronto tra propafenone ed amiodarone nella conversione al ritmo sinusale della fibrillazione atriale di recente insorgenza.

The effectiveness of propafenone versus amiodarone for conversion to sinus rhythm of paroxysmal atrial fibrillation was compared. Fifty-four consecutive adult patients affected by recent onset atrial fibrillation (< 7 days) were randomized to treatment with intravenous propafenone (27 patients) and amiodarone (27 patient). Sinus rhythm was restored respectively in 74.1% and 70.4% (p = ns); within 5 hours was obtained reconversion in 65% of propafenone and in 15.8% of amiodarone group (p < 0.05); the mean conversion time was 3.5 and 16.6 hours (p < 0.01). In conclusion propafenone seems to be as effective and safe as amiodarone, but is significantly fast in converting recent onset atrial fibrillation to sinus rhythm.