Utility of Soluble ST2 biomarker to predict recurrence after electrical cardioversion in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is the more frequent arrhythmia in clinical practice. The ST2S is a biomarker that has demonstrated to be predictor of cardiovascular outcomes in patients with heart failure but there is scarce information of his utility in patients with AF.

Purpose

Considering the characteristics of the ST2S we hypothesize this biomarker could correlate to recurrence in patients with AF and electrical cardioversion (ECV).

Methods

This was an observational and prospective clinical trial. We compared all patients with AF referred for ECV with a control group without AF, from September 1th 2016 to September 30 2019. Clinical, ECG, echocardiographic and ST2S levels were analyzed in both groups at basal, at 3 and 6 months of follow-up in such cases with AF. Patients with inflammatory or allergic diseases, moderate/severe ventricular dysfunction, structural cardiomyopathy, moderate/severe hepatic, renal or respiratory disease were excluded.

Results

We included a total of 94 patients with AF and 40 paired controls. Clinical variables are presented in Table 1. Fifty-eight (61.7%) patients with AF had recurrence at follow-up. There was a significant difference between the ST2S levels at baseline between AF patients (17163.8 pg/mL) and controls (11016.2 pg/mL) (p=0.001). ST2S biomarker levels at 3 and 6 months of follow-up decreased in those patients without AF recurrence as shown in Figure 1. Covariable models were performed and ST2S biomarker levels at 3 months were significant to predict recurrence at 6 months follow-up (Table 2). The calculated cut-point of the biomarker was of 15511.51 pg/ml with a c-value: 0.669.

Conclusions

In our experience ST2S was a useful biomarker to predict recurrence of AF after ECV. Considering the size of the study more studies should be performed to confirm this results.

Funding Acknowledgement

Type of funding sources: None.

Conventional single-chamber pacemakers versus transcatheter pacing systems at long-term follow-up

Background

Leadless pacemakers systems (LPM), have demonstrated safety and efficacy at mid-long term follow-up. There are still issues that cannot be completely avoided with conventional transvenous pacemaker (VVI) such as infectious or pocket related complications in which LPM are clearly superior.

Purpose

The aim of the study was to compare the clinical and device performance between LPM and VVI in a one-center long-term follow-up.

Methods

This was a prospective, observational, one-center study. We include all patients with a single chamber pacemaker implantation from June 1 2015 to March 1 2022 to complete a long-term follow-up. All clinical, electrical and echocardiographic characteristics, including electrical parameters, complications and mortality, were described.

Results

We included 245 patients with VVI pacemakers and 315 LPM. Mean age was 79.6±6.6 in LPM and 83.5±8.9 y/o in VVI pacemakers. All clinical, electrical and echocardiographic characteristics are described in Table 1. Electrical parameters of LPM were stable at long-term follow-up. There were a total of 7 complications in LPM and 17 in VVI pacemakers (p=0.006). There were no significant differences between major complications but there were in minor complications as shown in Table 2. There were no significant differences in mortality between both groups, but there was one death related to endocarditis in a VVI pacemaker patient during the follow-up (40,3±10 months).

Conclusions

In our study, there were no significant differences in terms of mortality and major complications between LMP and VVI at long-term follow-up. We consider our study supports the results in favor of the safety and effectiveness of LPM in the long-term.

Funding Acknowledgement

Type of funding sources: None.

Is Isolated tricuspid regurgitation different from functional tricuspid regurgitation?

Introduction

Isolated tricuspid regurgitation (TR) prevalence is increasing in the last decades. Its presence is associated with a worse prognosis when EROA is >40 mm2. Because of high surgery risk and increasing incidence, isolated TR is a challenge in modern cardiology.

Purpose

To evaluate the prevalence and characteristics of isolated TR compared to other TR aetiologies in a large cohort of patients.

Methods

Prospective study where consecutive patients undergoing an echocardiographic study within a three-month period were included. All studies with at least moderate TR were selected. Isolated TR was defined as TR with no likely pulmonary hypertension (>50 mmHg), no overt TR cause (no intrinsic tricuspid disease, LVEF ≥50%, no pacemaker/defibrillator wire across the tricuspid, no other significant valve disease, no disease that may cause TR, no congenital or pericardial heart disease); and no previous valve surgery. Patients with isolated TR and other aetiologies were compared.

Results

2121 patients with at least moderate TR were included. Isolated TR was found in 398 patients (18.8%). Basal characteristics are shown in table 1. Patients with isolated TR did not have a higher prevalence of AF (47.5% vs. 48.6% p=0.362). Isolated TR was less severe (20.5% vs. 32.1% of patients with severe TR; p<0.001) and less symptomatic (NYHA ≥ II in 27.8% of patients vs. 69.3%; p<0.001).

After selecting patients with at least severe TR, patients with isolated TR were also less symptomatic (NYHA≥II in 47.8% of patients vs. 70.7%; p<0.001) and they had better RV function (TAPSE <17 mm in 13.4% vs. 35.6%; p=0.001).

We found that patients with isolated severe TR had a larger tricuspid annulus diameter (25.4±0.8 mm/m2 vs. 24.0±0.3 mm/m2; p=0.047).

Conclusions

In this large prospective study, isolated TR is present in 18.8% of significant TR. Isolated TR was less severe, was associated with less RV dilatation (but with larger tricuspid annulus diameter) and patients had a better functional class compared to other TR aetiologies.

Differeces in NYHA and RV function

Funding Acknowledgement

Type of funding source: None

Influence of COVID-19 confinement on students' performance in higher education

This study analyzes the effects of COVID-19 confinement on the autonomous learning performance of students in higher education. Using a field experiment with 458 students from three different subjects at Universidad Autónoma de Madrid (Spain), we study the differences in assessments by dividing students into two groups. The first group (control) corresponds to academic years 2017/2018 and 2018/2019. The second group (experimental) corresponds to students from 2019/2020, which is the group of students that had their face-to-face activities interrupted because of the confinement. The results show that there is a significant positive effect of the COVID-19 confinement on students’ performance. This effect is also significant in activities that did not change their format when performed after the confinement. We find that this effect is significant both in subjects that increased the number of assessment activities and subjects that did not change the student workload. Additionally, an analysis of students’ learning strategies before confinement shows that students did not study on a continuous basis. Based on these results, we conclude that COVID-19 confinement changed students’ learning strategies to a more continuous habit, improving their efficiency. For these reasons, better scores in students’ assessment are expected due to COVID-19 confinement that can be explained by an improvement in their learning performance.

39 Overview of tricuspid regurgitation (tr). new classification of tr. when severe tr is too severe?

Introduction

Tricuspid regurgitation (TR) importance is growing in the last years. Its presence is associated with a worse prognosis. A new severity classification has been published, adding massive and torrential to the classical TR classification. However, it is not know how many of the patients classified as severe TR, corresponds to the new Torrential or massive classification that for sure will lead to different treatment strategies. Also few published studies have addressed the aetiologies, mechanisms and severity in large cohorts.

Purpose

To evaluate the burden of TR in a large cohort of patients referred for an echocardiography.

Methods

Prospective study where consecutive patients undergoing an echocardiographic study in 10 Spanish hospitals within a three-month period were included. All studies with at least moderate TR were selected for analysis. The evaluation was conduced according to the usual practice of the laboratory. TR assessment was performed as recommended by the European Association of Cardiovascular Imaging. TR was quantified according to Hanh & Zamorano new published classification.

Results

A total of 35088 consecutive echocardiographic studies were performed in the participant hospitals during the recruitment period. TR of at least moderate degree was detected in 2124 studies (6,05%). Mean age was 77,1 years and 62.8% were women.

Mitral or aortic valvulopthy was the most common cause, present in almost half of cases (48.4%). The second cause of TR was idiopathic with 22.2% of cases. Primary TR was found in 7.2% of patients, the most frequent aetiology in these group was cardiac implantable devices with 4.2% of total of TR. Aetiology and severity according to the new classification can be seen in the figures

Atrial fibrillation was present in 47.6% of cases. 56.4% of patients had symptoms at the time of the study (NYHA≥2 at the time of study).

Right ventricle (RV) was dilated (telediastolic basal diameter >42mm) in 39.4% of patients). RV function was impared (TAPSE <17mm) in 30.6% of patients.

Conclusions

In these larger multicentre study, significant TR may is present in up to 6% of the echocardiographic studies and is often symptomatic[m1] . 4,91% of patients had a massive or torrential grade. Most TR are secondary to mitral or aortic valvulopathy. Idiopathic TR has taken the second place.

Abstract 39 Figure. Severity and aetiology of TR

Loci-specific differences in blood DNA methylation in HBV-negative populations at risk for hepatocellular carcinoma development

Late onset of clinical symptoms in hepatocellular carcinoma (HCC) results in late diagnosis and poor disease outcome. Approximately 85% of individuals with HCC have underlying liver cirrhosis. However, not all cirrhotic patients develop cancer. Reliable tools that would distinguish cirrhotic patients who will develop cancer from those who will not are urgently needed. We used the Illumina HumanMethylation450 BeadChip microarray to test whether white blood cell DNA, an easily accessible source of DNA, exhibits site-specific changes in DNA methylation in blood of diagnosed HCC patients (post-diagnostic, 24 cases, 24 controls) and in prospectively collected blood specimens of HCC patients who were cancer-free at blood collection (pre-diagnostic, 21 cases, 21 controls). Out of 22 differentially methylated loci selected for validation by pyrosequencing, 19 loci with neighbouring CpG sites (probes) were confirmed in the pre-diagnostic study group and subjected to verification in a prospective cirrhotic cohort (13 cases, 23 controls). We established for the first time 9 probes that could distinguish HBV-negative cirrhotic patients who subsequently developed HCC from those who stayed cancer-free. These probes were identified within regulatory regions of BARD1, MAGEB3, BRUNOL5, FXYD6, TET1, TSPAN5, DPPA5, KIAA1210, and LSP1. Methylation levels within DPPA5, KIAA1210, and LSP1 were higher in prospective samples from HCC cases vs. cirrhotic controls. The remaining probes were hypomethylated in cases compared with controls. Using blood as a minimally invasive material and pyrosequencing as a straightforward quantitative method, the established probes have potential to be developed into a routine clinical test after validation in larger cohorts.

p-Type dopant incorporation and surface charge properties of catalyst-free GaN nanowires revealed by micro-Raman scattering and X-ray photoelectron spectroscopy

Micro-Raman scattering and X-ray photoelectron spectroscopy were employed to investigate Mg-doped GaN nanowires. With the increase of Mg doping level, pronounced Mg-induced local vibrational modes were observed. The evolution of longitudinal optical phonon-plasmon coupled mode, together with detailed X-ray photoelectron spectroscopy studies, show that the near-surface region of nanowires can be transformed from weakly n-type to p-type with the increase of Mg doping.

Inverted follicular keratosis: dermoscopic and reflectance confocal microscopic features

Inverted follicular keratosis (IFK) is a rare benign tumor which usually appears as a firm papule on the face. The diagnosis is generally made by histopathology because the clinical appearance is difficult to differentiate from other lesions. Dermoscopic features of IFK have not been established to date. Herein we describe the dermoscopic findings of 4 cases of IFK. Radial peripheral hairpin vessels surrounded by a whitish halo arranged around a central white-yellowish amorphous area were observed in 3 cases, and glomerular vessels were present in the central area of one of them. The fourth case also presented a central white amorphous area but showed arborizing vessels. Reflectance confocal microscopy (available in 1 case) revealed a broadened honeycomb pattern, epidermal projections and hairpin and glomerular vessels. To our knowledge this is the first case series describing the dermoscopic features of inverted follicular keratosis and the first confocal microscopy description of this entity.

Observation of phonon sideband emission in intrinsic InN nanowires: a photoluminescence and micro-Raman scattering study

In this work, photoluminescence and micro-Raman scattering experiments were performed on undoped InN nanowires. It was found that, besides the main photoluminescence peak, a clear phonon sideband emission peak, with an extremely narrow linewidth ~9 meV, was measured. The phonon spectrum revealed by micro-Raman scattering indicates only uncoupled LO phonons are involved in such phonon sideband emission. The clearly resolved phonon sideband emission peak with a narrow linewidth, together with the uncoupled LO phonon modes, suggests the superior quality of the presented InN nanowires, i.e., extremely low residual electron density and the absence of surface electron accumulation, which is consistent with the physical properties of intrinsic InN nanowires as in the previous studies. The detailed phonon sideband properties are also discussed in the text.

Involvement of TNF-alpha in abnormal adipocyte and muscle sortilin expression in obese mice and humans

AIMS/HYPOTHESIS

Insulin resistance is caused by numerous factors including inflammation. It is characterised by defective insulin stimulation of adipocyte and muscle glucose transport, which requires the glucose transporter GLUT4 translocation towards the plasma membrane. Defects in insulin signalling can cause insulin resistance, but alterations in GLUT4 trafficking could also play a role. Our goal was to determine whether proteins controlling GLUT4 trafficking are altered in insulin resistance linked to obesity.

METHODS

Using real-time RT-PCR, we searched for selected transcripts that were differentially expressed in adipose tissue and muscle in obese mice and humans. Using various adipocyte culture models and in vivo mice treatment, we searched for the involvement of TNF-alpha in these alterations in obesity.

RESULTS

Sortilin mRNA and protein were downregulated in adipose tissue from obese db/db and ob/ob mice, and also in muscle. Importantly, sortilin mRNA was also decreased in morbidly obese human diabetic patients. Sortilin and TNF-alpha (also known as TNF) mRNA levels were inversely correlated in mice and human adipose tissues. TNF-alpha decreased sortilin mRNA and protein levels in cultured mouse and human adipocytes, an effect partly prevented by the peroxisome proliferator-activated receptor gamma activator rosiglitazone. TNF-alpha also inhibited adipocyte and muscle sortilin mRNA when injected to mice.

CONCLUSIONS/INTERPRETATION

Sortilin, an essential player in adipocyte and muscle glucose metabolism through the control of GLUT4 localisation, is downregulated in obesity and TNF-alpha is likely to be involved in this defect. Chronic low-grade inflammation in obesity could thus contribute to insulin resistance by modulating proteins that control GLUT4 trafficking.

The nitric oxide-donating derivative of acetylsalicylic acid, NCX 4016, stimulates glucose transport and glucose transporters translocation in 3T3-L1 adipocytes

NCX 4016 is a nitric oxide (NO)-donating derivative of acetylsalicylic acid. NO and salicylate, in vivo metabolites of NCX 4016, were shown to be potential actors in controlling glucose homeostasis. In this study, we evaluated the action of NCX 4016 on the capacity of 3T3-L1 adipocytes to transport glucose in basal and insulin-stimulated conditions. NCX 4016 induced a twofold increase in glucose uptake in parallel with the translocation of the glucose transporters GLUT1 and GLUT4 to the plasma membrane, leaving unaffected their total expression levels. Importantly, NCX 4016 further increased glucose transport induced by a physiological concentration of insulin. The stimulatory effect of NCX 4016 on glucose uptake appears to be mediated by its NO moiety. Indeed, it is inhibited by a NO scavenger and treatment with acetylsalicylic or salicylic acid had no effect. Although NO is involved in the action of NCX 4016, it did not mainly depend on the soluble cGMP cyclase/protein kinase G pathway. Furthermore, NCX 4016-stimulated glucose transport did not involve the insulin-signaling cascade required to stimulate glucose transport. NCX 4016 induces a small activation of the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase and no activation of other stress-activated signaling molecules, including extracellular signal-regulated kinase, inhibitory factor kappaB, or AMP-activated kinases. Interestingly, NCX 4016 modified the content of S-nitrosylated proteins in adipocytes. Taken together, our results indicate that NCX 4016 induced glucose transport in adipocytes through a novel mechanism possibly involving S-nitrosylation. NCX 4016 thus possesses interesting characteristics to be considered as a candidate molecule for the treatment of patients suffering from metabolic syndrome and type 2 diabetes.

Kinetics of the biodegradation of green table olive wastewaters by aerobic and anaerobic treatments

The biodegradation of the organic pollutant matter present in green table olive wastewater (GTOW) is studied in batch reactors by an aerobic biodegradation and by an anaerobic digestion. In the aerobic biodegradation, the evolution of the substrate (in terms of chemical and biochemical oxygen demand), biomass, and total polyphenolic compounds present in the wastewater are followed during the process, and a kinetic study is performed using Contois' model, which when applied to the experimental results provides the kinetic parameter of this model, resulting in a modified Contois' equation (q=3.3S/(0.31S(0)X+X), gCOD/gVSS d(-1)). Other kinetic parameters were determined: the cellular yield coefficient (YX/S=5.7x10(-2) gVSS/gCOD) and the kinetic constant of cellular death phase (kd=0.16 d(-1)). Similarly, in the anaerobic digestion, the evolution of the substrate digested and the methane produced are followed, and the kinetic study is conducted using a modified Monod model combined with the Levenspiel model, due to the presence of inhibition effects. This model leads to the determination of the kinetic parameters: kinetic constant when no inhibitory substance is present (kM0=8.4x10(-2) h(-1)), critical substrate concentration of inhibition (TP*=0.34 g/L) and inhibitory parameter (n=2.25).

p38MAP Kinase activity is required for human primary adipocyte differentiation

Little is known about the role of p38MAPK in human adipocyte differentiation. Here we showed that p38MAPK activity increases during human preadipocytes differentiation. Pharmacological inhibition of p38MAPK during adipocyte differentiation of primary human preadipocytes markedly reduced triglycerides accumulation and adipocyte markers expression. Cell cycle arrest or proliferation was not affected by p38MAPK inhibition. Although induction of C/EBPbeta was not altered by the p38MAPK inhibitor, its phosphorylation on Threonine(188) was decreased as well as PPARgamma expression. These results indicate that p38MAPK plays a positive role in human adipogenesis through regulation of C/EBPbeta and PPARgamma factors.

Synthesis of Metallothionein-Mimic Decapeptides with Heavy Atom Signaling Properties

The automated parallel solid-phase synthesis of a 17-member library of metallothionein-mimic decapeptides carrying a Lariat ether group is described. The peptides were synthesized in good yield and the identity and quality of each product were performed by mass spectrometry and IR. Subsequently, in the presence of europium(III) ions as fluorescent reporter, each compound was screened, both attached to the resin and cleaved off, for their sensing behavior towards metal ions (Cd(2+),Hg(2+), Cu(2+), Mg(2+) and Ca(2+)) using fluorimetric techniques. Several of these Cys-enriched synthetic peptides showed surprisingly low detection limits for Cd(2+) and Hg(2+). The analytical potential of these metallothionein-mimic decapeptides as metal ion recognition materials for sensor development is outlined. Finally, the sensing response mechanism, based on an energy transfer process and a metal ion allosteric interaction, is proposed.

Should the 40-year-old practice of releasing virulent myxoma virus to control rabbits (Oryctolagus cuniculus) be continued?

Release of virulent myxoma virus has been a key component of rabbit-control operations in Queensland, Australia, since the 1960s but its use rests on anecdotal reports. During a routine operation to release virulent myxoma virus we found no evidence to support the continued regular use of the technique in south-west Queensland. Radio-tagged rabbits inoculated with virulent myxoma virus contracted the disease but failed to pass enough virus to other rabbits to spread the disease. Rabbits with clinical signs of myxomatosis that were shot were infected with field strain derived from the original laboratory strain released in 1950 rather than the virulent strain that has been released annually. There was no change in rabbit survival or abundance caused by the release. Nevertheless, the release of virulent virus may be useful against isolated pockets of rabbits mainly because field strains are less likely to be present. Such pockets are more common now that rabbit haemorrhagic disease virus is established in Queensland.

Library Preparation of Derivatives of 1,4,10,13-Tetraoxa-7,16-diaza-cycloctadecane and Their Fluorescence Behavior for Signaling Purposes

In the present work, we report the library preparation on solid supports of 20 derivatives of 1,4,10,13-tetraoxa-7,15-diaza-cycloctadecane 1(a-e)(w,x,y,z) carrying a fluorescent dansyl group. The sensing fluorescence behavior of these materials toward alkali and alkali earth metal ions was studied by packing the beads into a conventional flow-through cell in a FIA (flow injection analysis) approach. The fluorescence emission of these materials' responses shows a fluorescence increase to Li+, Na+, K+, NH4+, Ca2+, and Mg2+ with maximum sensitivity for Mg2+ over the rest of the ions. The analytical potential of these materials is outlined, and the sensing response mechanism, based on a photoinduced electron-transfer process, is proposed.

HTLV-1 modifies the clinical and immunological response to schistosomiasis

The immunological response in HTLV-1 infected individuals is characterized by a prominent Type-1 cytokine response with high production of IFN-gamma and TNF-alpha. In contrast, helminthic infections and in particular chronic schistosomiasis are associated with a predominant production of IL-4, IL-5, IL-10 and IL-13. Liver fibrosis is the main pathological finding in schistosomiasis that occurs after many years of infection. This pathology is T cell dependent but the immune response mechanisms are not completely understood. The North-east region of Brazil is endemic for both HTLV-1 and schistosomiasis. In the present study the immune response, clinical severity, and therapeutic response to praziquantel of patients with schistosomiasis coinfected with HTLV-1 were compared with patients infected only with S. mansoni. Patients with HTLV-1 and S. mansoni had lower levels of IL-5 (P < 0.05) and higher levels of IFN-gamma (P < 0.05) in cultures stimulated with S. mansoni antigen and decreased S. mansoni antigen specific IgE levels when compared with patients with schistosomiasis without HTLV-1 coinfection. Liver fibrosis was mild in all HTLV-1 coinfected patients and efficacy of praziquantel was lower in patients dually infected than in patients infected only with S. mansoni.

Fatty acid-induced insulin resistance: role of insulin receptor substrate 1 serine phosphorylation in the retroregulation of insulin signalling

Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterized by a decrease in the insulin effect on glucose transport in muscle and adipose tissue. Tyrosine phosphorylation of IRS-1 (insulin receptor substrate 1) and its binding to PI 3-kinase (phosphoinositide 3-kinase) are critical events in the insulin signalling cascade leading to insulin-stimulated glucose transport. Various studies have implicated lipids as a cause of insulin resistance in muscle. Elevated plasma fatty acid concentrations are associated with reduced insulin-stimulated glucose transport activity as a consequence of altered insulin signalling through PI 3-kinase. Modification of IRS-1 by serine phosphorylation could be one of the mechanisms leading to a decrease in IRS-1 tyrosine phosphorylation, PI 3-kinase activity and glucose transport. Recent findings demonstrate that non-esterified fatty acids, as well as other factors such as tumour necrosis factor alpha, hyperinsulinaemia and cellular stress, increase the serine phosphorylation of IRS-1 and identified Ser(307) as one of the phosphorylated sites. Moreover, several kinases able to phosphorylate this serine residue have been identified. These exciting results suggest that Ser(307) phosphorylation is a possible hallmark of insulin resistance in biologically insulin-responsive cells or tissues. Identification of IRS-1 kinases could enable rational drug design in order to selectively inhibit the activity of the relevant enzymes and generate a novel class of therapeutic agents for type 2 diabetes.

Alteration in insulin action: role of IRS-1 serine phosphorylation in the retroregulation of insulin signalling

Insulin resistance, when combined with impaired insulin secretion, contributes to the development of type 2 diabetes. Insulin resistance is characterised by a decrease in insulin effect on glucose transport in muscle and adipose tIssue. Tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) and its binding to phosphatidylinositol 3-kinase (PI 3-kinase) are critical events in the insulin signalling cascade leading to insulin-stimulated glucose transport. Modification of IRS-1 by serine phosphorylation could be one of the mechanisms leading to a decrease in IRS-1 tyrosine phosphorylation, PI 3-kinase activity and glucose transport. Recent findings demonstrate that "diabetogenic" factors such as FFA, TNFalpha, hyperinsulinemia and cellular stress, increase the serine phosphorylation of IRS-1 and identified Ser307/612/632 as phosphorylated sites. Moreover, several kinases able to phosphorylate these serine residues have been identified. These exciting results suggest that serine phosphorylation of IRS-1 is a possible hallmark of insulin resistance in biologically insulin responsive cells or tIssues. Identifying the pathways by which "diabetogenic" factors activate IRS-1 kinases and defining the precise role of serine phosphorylation events in IRS-1 regulation represent important goals. Such studies may enable rational drug design to selectively inhibit the activity of the relevant enzymes and generate a novel class of therapeutic agents for type 2 diabetes.

MAP kinases and mTOR mediate insulin-induced phosphorylation of insulin receptor substrate-1 on serine residues 307, 612 and 632

AIM/HYPOTHESIS

Insulin-induced IRS-1 serine phosphorylation could be physiologically important to regulate insulin action. In a hyperinsulinaemic state such as obesity or Type 2 diabetes, this phosphorylation could be modified and exacerbate insulin resistance. We aimed at identifying serine residues in IRS-1 phosphorylated in response to insulin stimulation and at determining the involved kinases.

METHODS

3T3-L1 adipocytes, muscle and adipose tissue of mice were subjected to Western Blot analysis with phosphospecific antibodies to identify phosphorylation sites in IRS-1 following insulin treatment. Pharmacological inhibitors were used to determine the serine kinases involved in this phosphorylation.

RESULTS

In 3T3-L1 adipocytes, insulin promoted the phosphorylation of serine 307, 612 and 632 with Serine(612/632) more rapidly phosphorylated than Serine(307). Insulin-induced phosphorylation of Serine(307) was dependent on the activation of a PI 3-kinase/mTOR pathway. The phosphorylation of Serine(612/632) required the activation of the MAP kinase pathway following short-term insulin stimulation and activation of the PI 3-kinase/mTOR pathway following prolonged insulin stimulation. Phosphorylation of Serine(307) and Serine(632) occurred in vivo in skeletal muscle and white adipose tissue of mice injected with insulin and was dependent on the activation of mTOR. Moreover, inhibition of mTOR led to a persistent PI 3-kinase activation by insulin.

CONCLUSION/INTERPRETATION

Insulin-induced IRS-1 serine phosphorylation is a complex process involving different sites and kinases. This complexity could be physiologically important to accurately regulate insulin signalling. Abnormal phosphorylation of these serine residues in hyperinsulinaemic state could participate in the down-regulation of insulin signalling.

Expression of a mineral phosphate solubilizing gene from Erwinia herbicola in two rhizobacterial strains

A genetic construction was carried out using the broad host range vector pKT230 and plasmid pMCG898, which encodes the Erwinia herbicola pyrroloquinoline quinone (PQQ) synthase, a gene involved in mineral phosphate solubilization (mps). The final construction was transformed and expressed in Escherichia coli MC1061, and the recombinant plasmids were transferred to Burkholderia cepacia IS-16 and Pseudomonas sp. PSS recipient cells by conjugation. Clones containing recombinant plasmids produced higher clearing halos in plates with insoluble phosphate as the unique (P) source, in comparison with those of strains without plasmids, demonstrating the heterologous expression of the E. herbicola gene in the recipient strains. This genetic manipulation allowed the increase in mps ability of both strains, enhancing their potentialities as growth promoters of agricultural crops. These results represent the first report on the application of the recombinant DNA methodology for the obtaining of improved phosphate solubilizing ability from rhizobacterial strains for biofertilization purposes.

Adapting pharmacokinetic properties of a humanized anti-interleukin-8 antibody for therapeutic applications using site-specific pegylation

A neutralizing anti-interleukin-(IL-)8 monoclonal antibody was humanized by grafting the complementary determining regions onto the human IgG framework. Subsequent alanine scanning mutagenesis and phage display enabled the production of an affinity matured antibody with a >100-fold improvement in IL-8 binding. Antibody fragments can be efficiently produced in Escherichia coli but have the limitation of rapid clearance rates in vivo. The Fab' fragment of the antibody was therefore modified with polyethylene glycol (PEG) in order to obtain a more desirable pharmacokinetic profile. PEG (5-40 kDa) was site-specifically conjugated to the Fab' via the single free cysteine residue in the hinge region. In vitro binding and bioassays showed little or no loss of activity. The pharmacokinetic profiles of the 20 kDa, 30 kDa, 40 kDa, and 40 kDa branched PEG-Fab' molecules were evaluated in rabbits. Relative to the native Fab', the clearance rates of the PEGylated molecules were decreased by 44-175-fold. In a rabbit ear model of ischemia/reperfusion injury, all PEGylated Fab' molecules were as efficacious in reducing oedema as the original monoclonal antibody. These studies demonstrate that it is possible to customize the pharmacokinetic properties of a Fab' while retaining its antigen binding activity.

Isolation of a gene from Burkholderia cepacia IS-16 encoding a protein that facilitates phosphatase activity

A genomic library from Burkholderia cepacia IS-16 was constructed in Escherichia coli by partial Sau3AI digestion of the chromosomal DNA, with the plasmid vector Bluescript SK. This library was screened for clones able to grow as green stained colonies on selective medium developed for detecting phosphatase-positive colonies. Three green-stained clones (pFS1, pFS2, and pFS3) carried recombinant plasmids harboring DNA inserts of 5.0, 8.0, and 0.9 kb, respectively. DNA hybridization experiments demonstrated the presence of overlapping DNA fragments in the three clones and that these three clones were all derived from Burkholderia cepacia IS-16 genomic DNA. DNA sequence analysis, together with polyacrylamide gels of proteins encoded by E. coli containing pFS3, suggested that the isolated 0. 9-kb DNA fragment encodes the functional portion of a phosphate transport protein.

Short-term cyclosporine induces a remission of autoimmune hepatitis in children

BACKGROUND/AIMS

The current immunosuppressive treatment of patients with autoimmune hepatitis consists of prednisone and azathioprine. High doses of prednisone used to obtain the remission of the disease are associated with serious adverse effects. To avoid harmful consequences of prednisone therapy, we proposed to treat patients with oral cyclosporine to obtain the remission of the inflammatory process.

METHODS

This is a pilot, multinational, multicenter, clinical trial involving children with autoimmune hepatitis. Thirty-two children were recruited, who according to international criteria were considered as having definite autoimmune hepatitis. Cyclosporine alone was administered for 6 months, followed by combined low doses of prednisone and azathioprine for 1 month, after which cyclosporine was discontinued. Biochemical remission of the disease was established by the follow-up of serum transaminase activity levels. Growth parameters and adverse effects of the treatment were recorded.

RESULTS

Two patients were withdrawn from the study: one for non-compliance and the other for liver failure which did not improve with cyclosporine. Of the 30 remaining patients, 25 normalized alanine aminotransferase activity levels by 6 months and all the patients by 1 year of treatment. Z-scores for height showed a trend towards improvement during treatment. Adverse effects of cyclosporine were mild and disappeared during weaning off the medication.

CONCLUSIONS

Cyclosporine induced the biochemical remission of the hepatic inflammatory/necrotic process in children with autoimmune hepatitis, with few and well-tolerated adverse effects.

Erosive azotemic osteoarthropathy of the hands in chronic ambulatory peritoneal dialysis and hemodialysis

OBJECTIVE

We studied the prevalence and significance of erosive azotemic osteoarthropathy (EAO) and its relationship with other osteoarticular abnormalities of dialysis-associated arthropathy (DAA).

METHODS

112 patients undergoing maintenance dialysis were studied: 63 hemodialysis (HD) and 49 continuous ambulatory peritoneal dialysis (CAPD). X-ray of the hands, shoulders, pelvis and cervical spine were examined for destructive spondyloarthropathy (SDA), bone cysts (BC), EAO and subperiosteal resorption. Beta 2-microglobulin (beta 2-m) and PTH were also measured.

RESULTS

Fifteen patients (13%) had EAO, usually in several joints of the hands, DIPs being the most frequently affected. Both patients on HD and those on CAPD had EAO, although the prevalence was higher in the HD group, 12 (19%) vs. 3 (6%). Patients with EAO were older (p < 0.05) and had more carpal tunnel syndrome (CTS) (p < 0.05) and BC (p < 0.01). Only 3 out of 15 patients with EAO had severe secondary hyperparathyroidism (sHPTH) (PTH > 500), while 9/15 had neither radiologic nor laboratory evidence of sHPTH. No differences were found regarding the duration of dialysis, or beta 2-m or PTH level.

CONCLUSION

EAO is not related to sHPTH and should be included within the spectrum of the clinical manifestations of DAA. Due to its location and radiologic picture, it is possible that etiologic factors leading to primary osteoarthritis may play a role in the development and evolution of EAO.

Histopathological changes in the reproductive organs of Manchego ewes grazing on lucerne

The effects of prolonged exposure to phyto-oestrogens (coumestrol) on the morphology of the reproductive organs of ewes were studied in 28 lucerne-grazing animals, and compared with 28 control ewes given a standard coumestrol-free diet. The anatomical studies showed that 43% of the ewes fed lucerne displayed macroscopic changes within the genital tract, of which the uterine alterations were especially prominent. The microscopic examination of the test group ewes identified specific histopathological features of the uterus and cervix. A greater than normal development of the cervical folds was observed, as well as cystic formations of different sizes whose content was eosinophilic. In the rest of the uterus, more glandular activity was detected in the lucerne-grazing group than in the control ewes, although cystic formations were not seen.

Epidemiology of renal involvement in type II diabetics (NIDDM) in Catalonia. The Catalan Diabetic Nephropathy Study Group

The aim of this cross-sectional study was to establish the prevalence of renal involvement and to identify associations with its most important possible risk factors in a group of patients with Type II diabetes mellitus, representative of the population living in Catalonia. One thousand two hundred and three patients (47% males, mean age: 61 +/- 6 years, diabetes duration 9 +/- 6 years) were studied. Overnight urine samples were collected to determine urinary albumin excretion (UAE). If UAE was > 15 micrograms/min, a new 24-h urine collection for UAE measurement to establish the existence of microalbuminuria (20-200 micrograms/min) or macroalbuminuria (> 200 micrograms/min) was obtained. Clinic and metabolic evaluations were also performed. The prevalence (%) of microalbuminuria, macroalbuminuria and hypertension were, respectively, 23. 1, 5.4 and 42. In comparison with normoalbuminurics, patients with microalbuminuria were predominately male (P < 0.03), with a significantly higher systolic (P < 0.001) and diastolic (P < 0.001) blood pressure and body mass index (P < 0.001). The prevalence of smokers (former + current) was higher in patients with microalbuminuria (43 vs 32%, P < 0.025). Moreover, patients with nephropathy had more prevalence of retinopathy (P < 0.001), neuropathy (P < 0.001), peripheral angiopathy (P < 0.001) and coronary disease (P < 0.001). The prevalence of microalbuminuria in Type II diabetes in Catalonia is similar to that observed in other european countries. The existence of microalbuminuria is associated with several diabetic complications, as well as tobacco consumption and obesity.

Identification of amino acids in the CD11a I-domain important for binding of the leukocyte function-associated antigen-1 (LFA-1) to intercellular adhesion molecule-1 (ICAM-1)

Leukocyte function-associated antigen-1 (LFA-1) is a cell surface adhesion receptor for intercellular adhesion molecule-1, -2, and -3 (ICAM-1, -2, -3). Using human/murine chimeras of the I-domain of the LFA-1 alpha subunit (CD11a), we recently identified the epitopes recognized by eight monoclonal antibodies against CD11a that inhibit LFA-1 binding to ICAM-1. In this report, we determined that replacement of the entire human I-domain with the entire murine I-domain in CD11a completely abrogated LFA-1 binding to human ICAM-1 without affecting the gross conformation or heterodimer formation of LFA-1, as assayed by antibody binding. In order to assess which residues of the I-domain are responsible for binding to ICAM-1, we tested the ability of a panel of human/murine I-domain chimeras to bind to human ICAM-1. When complexed with CD18, all CD11a chimeras bound ICAM-1 at levels comparable to wild-type CD11a/CD18, indicating that the residues in these chimeras which differ in human and murine I-domains may not play a critical role in LFA-1 binding to ICAM-1. A series of point mutations of residues that are conserved between murine and human CD11a I-domains, as well as between CD11b and CD11c, were also generated. Substitution of alanine for proline at position 192 in the human CD11a I-domain abrogated adhesion of LFA-1 to ICAM-1. Antibody binding data suggested that this was due to conformational changes within the I-domain. Mutation of the aspartic acids at positions 137 and 239 to either alanine or lysine completely destroyed ICAM-1 binding. The conformation of LFA-1 alanine mutants was not significantly altered. This suggests that these aspartic acids are required for binding of human LFA-1 to human ICAM-1.

X-ray structures of fragments from binding and nonbinding versions of a humanized anti-CD18 antibody: structural indications of the key role of VH residues 59 to 65

X-ray crystal structures of fragments from two different humanized anti-CD18 antibodies are reported. The Fv fragment of the nonbinding version has been refined in space group C2 with a = 64.2 A, b = 61.3 A, c = 51.8 A, and beta = 99 degrees to an R-value of 18.0% at 1.9 A, and the Fab fragment of the tight-binding version has been refined in space group P3 with a = 101. A and c = 45.5 A to an R-value of 17.8% at 3.0 A resolution. The very large difference in their binding affinity (> 1000-fold) is attributed to large and local structural differences in the C-terminal part of CDR-H2, and from this we conclude there is direct contact between this region and antigen when they combine. X-ray structures of antibody-antigen complexes available in the literature have yet to show this part of CDR-H2 in contact with antigen, despite its hypervariable sequence. Implications of this result for antibody humanization are discussed.

The use of polymorphic Alu insertions in human DNA fingerprinting

We have characterized several Human Specific (HS) Alu insertions as either dimorphic (TPA25, PV92, APO), slightly dimorphic (C2N4 and C4N4) or monomorphic (C3N1, C4N6, C4N2, C4N5, C4N8) based on studies of Caucasian, Asian, American Black and African Black populations. Our approach is based upon: 1) PCR amplification using primers complementary to the unique DNA sequences that flank the site of insertion of the different Alu elements studied; 2) gel electrophoresis and scoring according to the presence or absence of an Alu insertion in one or both homologous chromosomes; 3) allele frequencies determined by gene counting and compared to Hardy-Weinberg expectations. Our DNA fingerprinting procedure using PCR amplification of diallelic polymorphic (dimorphic) Human Specific Alu insertions, may be used as a tool for genetic mapping, to characterize populations, study human migrational patterns, and track the inheritance of human genetic disorders.

[Cardiac output studied by a non invasive method in hypertensive patients]

We measured by thoracic bioimpedance (BoMed, NCCOM3-R7) non invasive cardiac index (CI), stroke index (SI) and systemic vascular resistance index (SVRI) in 48 hypertensive patients (OMS) compared to 30 normotensive. The mean arterial pressure (MAP) and the SVRI were significantly higher in the hypertensive group while the CI are significantly lower, as that was shown in previous invasive studies. We found an inverse correlation between age and CI (r = -.30, p < or = .05) in relation with a negative correlation between SI and age (r = -.35, p < or = .05) and no correlation between heart rate and age. Furthermore we divided normotensive and hypertensive patients in three groups of CI (low CI < 2.8 l/min/m2, 2.8 < or = normal CI < or = 4.2 l/min/m2, high CI > 4.2 l/min/m2) and in three groups of SVRI (low SVRI < 1660 Flohms/m2, 1660 < or = normal SVRI < or = 2580 Flohms/m2, high SVRI > 2580 Flohms/m2). Despite CI diminution in hypertension, high CI percentage's was the same in normotensive and hypertensive patients. In conclusion, these results confirm previous studies by using a simple, easy, non invasive and reproducible method.

[Cardiac mass, ventricular relaxation parameters and their correlation with blood pressure during rest and ambulatory monitoring]

A resting blood pressure (Dynamap, 8AM-8PM, one recording every 15 minutes) has been recorded among 60 patients; mean age: 51 +/- 14 years (24 females, 36 males; 3 normotensive and 57 hypertensive WHO) and a echocardiogram TM and two-dimensional with doppler in order to measure the interventricular septum thickness, Left Ventricular Posterior Wall Thickness and the left Ventricular Internal diameter with which we can calculate the myocardial mass (MM, Devereux formula) and the myocardial mass index using the body surface. Furthermore ventricular relaxation has been studied (A/E, PHT) by using doppler echocardiogram. During the same week an ambulatory blood pressure (Nippon Colin 8AM-8PM one reading every 15 minutes) has been recorded. The blood variables are the mean of the recording, systolic, diastolic, mean. We have confirmed the conclusion between blood pressure and left ventricular mass by using resting and ambulatory blood pressure recordings. But it does not exist any significant difference within we compare the correlations coefficients (Hotteling's Test with Williams modification) obtained with two devices. In revenge this difference exists with ventricular relaxation index A/E to MBP: mMBPr = 0.51, mMBPa = 0.34 (p less than 0.05), and PHT to MBP: mMBPr = 0.49, mMBPa = 0.31, (p less than 0.05) and to the SBP: mSBPr = 0.54, mSBPa = 0.35, (p less than 0.05).

CONCLUSION

the relationship between blood pressure and myocardial mass and by, the heart effect from hypertension can be studied by using in any case resting and ambulatory blood pressure recordings. This will confirm the hypothesis in which the blood pressure recordings multiplication is more important than the way of recording it.(ABSTRACT TRUNCATED AT 250 WORDS)

Familial articular chondrocalcinosis in Spain

One hundred and one first degree relatives of 35 patients with chondrocalcinosis were examined for the presence of familial disease. Eleven subjects from nine families showed radiological chondrocalcinosis, a prevalence of familial disease of 26%. Two different patterns of disease were noted--the older generation was more commonly affected, and the younger generation and second degree relatives were exempt. Clinical and radiological differences were found between the early and late onset groups, but not between late onset and sporadic forms of chondrocalcinosis. These findings support the suggestion that the true prevalence of familial disease. is underestimated. A dominant, autosomal transmission with variable penetrance is consistent with our findings, which suggests that homozygous patients with familial chondrocalcinosis may present a more severe form of the disease.