Graphene Oxide: Key to Efficient Charge Extraction and Suppression of Polaronic Transport in Hybrids with Poly (3-hexylthiophene) Nanoparticles

Nanoparticles (NPs) of conjugated polymers in intimate contact with sheets of graphene oxide (GO) constitute a promising class of water-dispersible nanohybrid materials of increased interest for the design of sustainable and improved optoelectronic thin-film devices, revealing properties exclusively pre-established upon their liquid-phase synthesis. In this context, we report for the first time the preparation of a P3HT_NPs-GO nanohybrid employing a miniemulsion synthesis approach, whereby GO sheets dispersed in the aqueous phase serve as a surfactant. We show that this process uniquely favors a quinoid-like conformation of the P3HT chains of the resulting NPs well located onto individual GO sheets. The accompanied change in the electronic behavior of these P3HT_NPs, consistently confirmed by the photoluminescence and Raman response of the hybrid in the liquid and solid states, respectively, as well as by the properties of the surface potential of isolated individual P3HT_NPs-GO nano-objects, facilitates unprecedented charge transfer interactions between the two constituents. While the electrochemical performance of nanohybrid films is featured by fast charge transfer processes, compared to those taking place in pure P3HT_NPs films, the loss of electrochromic effects in P3HT_NPs-GO films additionally indicates the unusual suppression of polaronic charge transport processes typically encountered in P3HT. Thus, the established interface interactions in the P3HT_NPs-GO hybrid enable a direct and highly efficient charge extraction channel via GO sheets. These findings are of relevance for the sustainable design of novel high-performance optoelectronic device structures based on water-dispersible conjugated polymer nanoparticles.

Patients with hepatocellular carcinoma that die during the first year of liver transplantation have high blood sFasL concentrations

BACKGROUND

Fas ligand (FasL) is one ligand that activates extrinsic apoptosis pathway. High expression in lymphocytes of FasL have been found in patients with acute rejection of liver transplantation (LT). No high blood concentrations of soluble FasL (sFasL) have been found in patients with acute LT rejection; however, the samples size of those studies was small.

AIM

To determine whether patients with hepatocellular carcinoma (HCC) that dead during the first year of LT have higher blood sFasL concentrations previously to LT that those who that remain alive in a study of higher sample size.

METHODS

Patients underwent LT due to HCC were included in this retrospective study. Serum sFasL levels prior to LT were measured and one-year LT mortality was registered.

RESULTS

Non-surviving patients (n = 14) showed higher serum sFasL levels [477 (269-496) vs 85 (44-382) pg/mL; P < 0.001] than surviving patients (n = 113). Serum sFasL levels (pg/mL) were associated with mortality (OR = 1.006; 95%CI = 1.003-1.010; P = 0.001) independently of age of LT donor in the logistic regression analysis.

CONCLUSION

We report for the first time that HCC patients who die within the first year of HT have higher blood sFasL concentrations prior to HT than those who remain alive.

DNA and RNA oxidative damage in hepatocellular carcinoma patients and mortality during the first year of liver transplantation

BACKGROUND

Oxidative damage of DNA and RNA has been associated with mortality of patients with different diseases. However, there is no published data on the potential use of DNA and RNA oxidative damage to predict the prognosis of patients with hepatocellular carcinoma (HCC) undergoing liver transplantation (LT).

AIM

To determine whether patients with increased DNA and RNA oxidative damage prior to LT for HCC have a poor LT prognosis.

METHODS

Patients with HCC who underwent LT were included in this observational and retrospective study. Serum levels of all three oxidized guanine species (OGS) were measured prior to LT since guanine is the nucleobase that forms DNA and RNA most prone to oxidation. LT mortality at 1 year was the end-point study.

RESULTS

Surviving patients (n = 101) showed lower serum OGS levels (P = 0.01) and lower age of the liver donor (P = 0.03) than non-surviving patients (n = 13). An association between serum OGS levels prior to LT and 1-year LT (odds ratio = 2.079; 95% confidence interval = 1.356-3.189; P = 0.001) was found in the logistic regression analysis.

CONCLUSION

The main new finding was that high serum OGS concentration prior to LT was associated with the mortality 1 year after LT in HCC patients.

Liver transplant with controlled donors after circulatory death with normothermic regional perfusion and brain dead donors: A multicenter cohort study of transfusion, one-year graft survival and mortality

BACKGROUND

Controlled donation after circulatory death (cDCD) has expanded the donor pool for liver transplantation (LT). However, transfusion requirements and perioperative outcomes should be elucidated. The aim of this multicenter study was to assess red blood cell (RBC) transfusions, one-year graft and patient survival after LT after cDCD with normothermic regional perfusion (NRP) compared with donors after brain death (DBD).

METHODS

591 LT carried out in ten centers during 2019 were reviewed. Thromboelastometry was used to manage coagulation and blood product transfusion in all centers. Normothermic regional perfusion was the standard technique for organ recovery.

RESULTS

447 patients received DBD and 144 cDCD with NRP. Baseline MCF Extem was lower in the cDCD group There were no differences in the percentage of patients (63% vs. 61% p = 0.69), nor in the number of RBC units transfused (4.7 (0.2) vs 5.5 (0.4) in DBD vs cDCD, p = 0.11. Twenty-six patients (6%) died during admission for LT in the DBD group compared with 3 patients (2%) in the cDCD group (p = 0.15). To overcome the bias due to a worse coagulation profile in cDCD recipients, matched samples were compared. No differences in baseline laboratory data, or in intraoperative use of RBC or one-year outcome data were observed between DBD and cDCD recipients.

CONCLUSIONS

cDCD with NRP is not associated with increased RBC transfusion. No differences in graft and patient survival between cDCD and DBD were found. Donors after controlled circulatory death with NRP can increasingly be utilized with safety, improving the imbalance between organ donors and the ever-growing demand.

Time course of improvement in novel nitric oxide-regulated hormones in response to exercise training in middle-aged and older adults

Introduction

Cardiovascular disease risk augments with advance of age. The mechanism of the increased cardiovascular disease risk by aging is related to attenuation of arterial function via endothelium-derived relaxing factor, such as nitric oxide (NO). Recently, apelin and adropin have identified as NO-upregulated hormones, whereas augmented secretion of asymmetric dimethylarginine (ADMA) have identified as NO-downregulated hormones. However, the effects of exercise training-induced changes in NO-regulated hormones on the reduction of arterial stiffness via NO productions remain unclear.

Purpose

This study aimed to determine the time-dependent changes in NO-regulated hormones related to exercise-training effects of arterial stiffness via NO productions in healthy middle-aged and older adults.

Methods

Thirty-two Japanese healthy middle-aged and older subjects (67±1 years) were randomly divided into two groups: exercise intervention and sedentary controls. Subjects in the training group completed 8-week of aerobic exercise training (60–70% peak oxygen uptake [VO2peak] for 45 min, 3 days/week). We evaluated plasma nitrite/nitrate (NOx), apelin, and ADMA levels, serum apelin level and carotid-femoral pulse wave velocity (cfPWV) as an index of arterial stiffness, measured every 2 weeks for 8-week in the training group.

Results

cfPWV was gradually declined from baseline to 8-week and significantly decreased from baseline at weeks 6 (P&lt;0.05) and 8 (P&lt;0.01). Plasma NOx level was gradually elevated during exercise intervention and significantly increased from baseline at weeks 6 (P&lt;0.05) and 8 (P&lt;0.01). Interestingly, plasma apelin and serum adropin levels were gradually elevated during exercise intervention and significantly increased from baseline at weeks 4, 6 and 8 (each P&lt;0.01). Additionally, plasma ADMA level was significantly decreased at 8-week intervention (P&lt;0.01). Furthermore, the exercise training-induced increase in plasma NOx level was significantly correlated with the changes in circulating apelin (r=0.505, P&lt;0.05), adropin (r=0.662, P&lt;0.01), or ADMA (r=−0.483, P&lt;0.05) levels before and after the 8-week. The exercise training-induced increase in plasma NOx level was significantly correlated with training-induced changes in circulating apelin (r=0.483, P&lt;0.05) or adropin (r=0.556, P&lt;0.05) before and after the 6-week.

Conclusions

These results suggest that the NO-upregulated hormones (apelin and adropin) were increased at the early stage of exercise training intervention and NO-downregulated hormone (ADMA) was decreased at the late stage of exercise training intervention, and these changes in NO-regulated hormones may be contributed to the reduction of arterial stiffness in the middle-aged and older adults.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

When genetic and surname analyses meet historical sources: The C56R mutation associated with factor XI deficiency as a marker of human migration during the Spanish Reconquista

The C56R mutation associated with factor XI deficiency has been first evidenced in individuals from the French Basque Country. Genetic investigations revealed that this mutation occurred about 5400 years ago as a founder effect in this zone. Other cases were subsequently described in Southwestern Europe. Noticeably a cluster of cases was evidenced in Yecla, a small city from the province of Murcia, in Southeastern Spain. In correlation with historical sources our genetic data and surname analysis argue for associating this mutation with the migration of people from Western Pyrenees (and more probably from the Navarra province) toward Southeastern Spain during the Reconquista period.

Impact of an excise tax on the consumption of sugar-sweetened beverages in young people living in poorer neighbourhoods of Catalonia, Spain: a difference in differences study

Background

Sugar-sweetened beverage consumption is contributing to the obesity epidemic. On 28 March 2017, Catalonia enacted a law levying an excise tax on sugar-sweetened beverages for public health reasons. The purpose of this study is to assess the impact of the tax on the consumption of sugar-sweetened beverages in Catalonia (Spain).

Methods

Before-and-after study to assess changes in the prevalence of consumption of sugar-sweetened beverages among 1929 persons aged 12 to 40 years residing in low-income neighbourhoods of Barcelona (intervention) and Madrid (control). Beverage consumption frequency was ascertained via a validated questionnaire administered during the month prior to the tax’s introduction (May 2017) and again at 1 year after it had come into force. The effect of the tax was obtained using Poisson regression models with robust variance weighted using propensity scores.

Results

While the prevalence of regular consumers of taxed beverages fell by 39% in Barcelona as compared to Madrid, the prevalence of consumers of untaxed beverages remained stable. The main reason cited by more than two-thirds of those surveyed for reducing their consumption of sugar-sweetened beverages was the increase in price, followed by a heightened awareness of their health effects.

Conclusions

The introduction of the Catalonian excise tax on sugar-sweetened beverages was followed by a reduction in the prevalence of regular consumers of taxed beverages.

Impact of an excise tax on the consumption of sugar-sweetened beverages in Catalonia, Spain

Background

Sugar-sweetened beverage consumption is contributing to the obesity epidemic. On 28 March 2017, Catalonia enacted a law levying an excise tax on sugar-sweetened beverages for public health reasons. The purpose of this study is to assess the impact of the tax on the consumption of sugar-sweetened beverages in Catalonia (Spain).

Methods

Before-and-after study to assess changes in the prevalence of consumption of sugar-sweetened beverages among 1929 persons aged 12 to 40 years residing in low-income neighbourhoods of Barcelona (intervention) and Madrid (control). Beverage consumption frequency was ascertained via a validated questionnaire administered during the month prior to the tax’s introduction (May 2017) and again at one year after it had come into force. The effect of the tax was obtained using Poisson regression models with robust variance.

Results

While the prevalence of regular consumers of taxed beverages fell by 41% in Barcelona as compared to Madrid, the prevalence of consumers of untaxed beverages remained stable. The main reason cited by more than two-thirds of those surveyed for reducing their consumption of sugar-sweetened beverages was the increase in price, followed by a heightened awareness of their health effects.

Conclusions

The introduction of the Catalonian excise tax on sugar-sweetened beverages was followed by a reduction in the prevalence of regular consumers of taxed beverages.

Key messages

This is the first study to show the efficacy of the Catalonian excise tax to reduce the prevalence of regular consumers of sugar sweetened beverages by residents of low-income neighbourhoods in Spain. Our results, along with the remaining scientific evidence on the subject, would justify the extension of the measure to the rest of Spain for public health reasons.

High serum caspase-3 levels in hepatocellular carcinoma prior to liver transplantation and high mortality risk during the first year after liver transplantation

Background: Higher liver caspase-3 activity has been found in patients with different liver diseases. However, there is no published data about circulating caspase-3 levels in patients with hepatocellular carcinoma (HCC) who underwent liver transplantation (LT). Therefore, our objective in this study was to determine whether an association between circulating caspase-3 levels in HCC patients prior to LT and one-year mortality after LT exists. Methods: In this observational and retrospective study, we included HCC patients who underwent LT. We measured serum levels of caspase-3 (as the main executor of apoptosis) and caspase-cleaved cytokeratin (CCCK)-18 (to estimate apoptosis degree) before LT. Results: One-year surviving LT patients (n = 129) showed lower serum levels of caspase-3 (p = 0.004) and CCCK-18 (p = 0.001) than non-surviving LT patients (n = 16). Logistic regression analysis showed that serum caspase-3 levels prior to LT were associated with one-year after LT mortality (Odds Ratio = 2.612; 95% CI = 1.519-4.493; p = 0.001). We found a positive association between serum levels of caspase-3 and CCCK-18 (rho = 0.26; p = 0.002). Conclusions: Our study is the first one reporting data of circulating caspase-3 levels prior to LT for HCC, and an association between high serum caspase-3 levels previously to LT and survival at first year after LT.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Serum total antioxidant capacity prior to liver transplantation for hepatocellular carcinoma is associated with 1-year liver transplantation survival

Objective

To determine whether there was an association between serum total antioxidant capacity (TAC) levels prior to in liver transplantation (LT) for hepatocellular carcinoma (HCC) and 1-year LT mortality.

Methods

This observational retrospective single-centre study of patients with LT for HCC measured serum levels of TAC and malondialdehyde (as a biomarker of lipid peroxidation) before LT. The study endpoint was 1-year LT mortality.

Results

This study included 142 patients who underwent LT for HCC. Patients who survived the first year (n = 127) had significantly lower aged liver donors, significantly higher serum TAC levels, and significantly lower serum malondialdehyde levels compared with the non-survivors (n = 15). Logistic regression analysis found that serum TAC levels (odds ratio [OR] 0.275; 95% confidence interval [CI] 0.135, 0.562) and the age of the LT donor (OR 1.050; 95% CI 1.009, 1.094) were associated with 1-year LT mortality. There was an inverse association between serum levels of TAC and malondialdehyde levels (rho = –0.22).

Conclusions

There was an association between low serum TAC levels prior to LT for HCC and mortality during the first year after LT. There was an inverse association between serum TAC levels and lipid peroxidation as measured by malondialdehyde levels.

Patients with high serum substance P levels previously to liver transplantation for hepatocellular carcinoma have higher risk of one-year liver transplantation mortality

Purpose

Substance P is a tachykinins family member with inflammatory effects. Higher circulating levels of substance P have been found in patients with liver diseases and in patients with higher severity of liver diseases. The objective of this study was to determine whether serum levels of substance P levels, prior to liver transplantation (LT) for hepatocellular carcinoma (HCC) are associated with one-year LT mortality.

Material and Methods

In this observational retrospective unicenter study were included patients with LT for HCC. Serum levels of substance P were measured before LT. The end-point of the study was one-year mortality after LT.

Results

We found that one-year survivor patients (n = 127) showed a lower age in liver donors (p = 0.03) and lower levels of serum substance P levels (p = 0.003) than non-survivor patients (n = 15). Logistic regression analysis showed that serum levels of substance P (levels) were associated with one-year mortality (Odds Ratio = 1.011; 95% CI = 1.004–1.018; p = 0.002) controlling for the age of the LT donor.

Conclusions

We believe that our study is the first study reporting data on circulating levels of substance P previously to LT for HCC, and an association between elevated levels of serum substance P before LT and mortality during the first year of LT.

Fluid and Volume Monitoring

Background

Fluid resuscitation is not only used to prevent acute kidney injury (AKI) but fluid management is also a cornerstone of treatment for patients with established AKI and renal failure. Ultrafiltration removes volume initially from the intravascular compartment inducing a relative degree of hypovolemia. Normal reflex mechanisms attempt to sustain blood pressure constant despite marked changes in blood volume and cardiac output. Thus, compensated shock with a normal blood pressure is a major cause of AKI or exacerbations of AKI during ultrafiltration.

Methods

We undertook a systematic review of the literature using MEDLINE, Google Scholar and PubMed searches. We determined a list of key questions and convened a 2-day consensus conference to develop summary statements via a series of alternating breakout and plenary sessions. In these sessions, we identified supporting evidence and generated clinical practice recommendations and/or directions for future research.

Results

We defined three aspects of fluid monitoring: i) normal and pathophysiological cardiovascular mechanisms; ii) measures of volume responsiveness and impending cardiovascular collapse during volume removal, and; iii) measured indices of each using non-invasive and minimally invasive continuous and intermittent monitoring techniques. The evidence documents that AKI can occur in the setting of normotensive hypovolemia and that under-resuscitation represents a major cause of both AKI and mortality ion critically ill patients. Traditional measures of intravascular volume and ventricular filling do not predict volume responsiveness whereas dynamic functional hemodynamic markers, such as pulse pressure or stroke volume variation during positive pressure breathing or mean flow changes with passive leg raising are highly predictive of volume responsiveness. Numerous commercially-available devices exist that can acquire these signals.

Conclusions

Prospective clinical trials using functional hemodynamic markers in the diagnosis and management of AKI and volume status during ultrafiltration need to be performed. More traditional measure of preload be abandoned as marked of volume responsiveness though still useful to assess overall volume status.

High incidence of FXI deficiency in a Spanish town caused by 11 different mutations and the first duplication of F11: Results from the Yecla study

INTRODUCTION

Factor XI (FXI) deficiency is a rare disorder with molecular heterogeneity in Caucasians but relatively frequent and molecularly homogeneous in certain populations.

AIM

To characterize FXI deficiency in a Spanish town of 60 000 inhabitants.

METHODS

A total of 324 764 APTT tests were screened during 20 years. FXI was evaluated by FXI:C and by Western blot. Genetic analysis of F11 was performed by sequencing, multiplex ligation-dependent probe amplification and genotyping.

RESULTS

Our study identified 46 unrelated cases and 170 relatives with FXI deficiency carrying 12 different genetic defects. p.Cys56Arg, described as founder mutation in the French-Basque population, was identified in 109 subjects from 24 unrelated families. This mutation was also identified in 2% of the general population. p.Cys416Tyr, c.1693G>A and p.Pro538Leu were identified in 7, 6 and 2 unrelated families, respectively. NGS analysis of the whole F11 gene revealed a common haplotype for each of the four recurrent mutations, suggesting a founder effect. The analysis of plasma FXI of four p.Pro538Leu homozygous carriers revealed that this variant was not activated by FXIIa. We identified four mutations previously described in other Caucasian subjects with FXI deficiency (p.Lys536Asn; p.Thr322Ile, p.Arg268Cys and c.325G>A) and four new gene defects: p.(Cys599Tyr) potentially causing a functional deficiency, p.(Ile426Thr), p.(Ile592Thr) and the first worldwide duplication of 1653 bp involving exons 8 and 9. Bleeding was rare and mild.

CONCLUSIONS

Our population-cohort study supplies new evidences that FXI deficiency in Caucasians is more common than previously thought and confirmed the wide underlying genetic heterogeneity, caused by both recurrent and sporadic mutations.

Uniparental disomy causes deficiencies of vitamin K-dependent proteins

Essentials Vitamin K-dependent coagulant factor deficiency (VKCFD) is a rare autosomal recessive disorder. We describe a case of inherited VKCFD due to uniparental disomy. The homozygous mutation caused the absence of GGCX isoform 1 and overexpression of Δ2GGCX. Hepatic and non-hepatic vitamin K-dependent proteins must be assayed to monitor VKCFD treatment.

SUMMARY

Background Inherited deficiency of all vitamin K-dependent coagulant factors (VKCFD) is a rare autosomal recessive disorder caused by mutations in the γ-glutamyl carboxylase gene (GGCX) or the vitamin K epoxide reductase gene (VKORC1), with great heterogeneity in terms of both clinical presentation and response to treatment. Objective To characterize the molecular basis of VKCFD in a Spanish family. Methods and Results Sequencing of candidate genes, comparative genomic hybridization and massive sequencing identified a new mechanism causing VKCFD in the proband. Uniparental disomy (UPD) of chromosome 2 caused homozygosity of a mutation (c.44-1G>A) resulting in aberrant GGCX splicing. This change contributed to absent expression of the mRNA coding for the full-length protein, and to four-fold overexpression of the smaller mRNA isoform lacking exon 2 (Δ2GGCX). Δ2GGCX might be responsible for two unexpected clinical observations in the patient: (i) increased plasma osteocalcin levels following vitamin K1 supplementation; and (ii) a mild non-bleeding phenotype. Conclusions Our study identifies a new autosomal disease, VKCFD1, caused by UPD. These data suggest that the Δ2GGCX isoform may retain enzymatic activity, and strongly encourage the evaluation of both hepatic and non-hepatic vitamin K-dependent proteins to assess differing responses to vitamin K supplementation in VKCFD patients.

Inhibition of PKC-dependent extracellular Ca2+ entry contributes to the depression of contractile activity in long-term pressure-overloaded endothelium-denuded rat aortas

We examined the contractile responsiveness of rat thoracic aortas under pressure overload after long-term suprarenal abdominal aortic coarctation (lt-Srac). Endothelium-dependent angiotensin II (ANG II) type 2 receptor (AT₂R)-mediated depression of contractions to ANG II has been reported in short-term (1 week) pressure-overloaded rat aortas. Contractility was evaluated in the aortic rings of rats subjected to lt-Srac or sham surgery (Sham) for 8 weeks. ANG I and II levels and AT₂R protein expression in the aortas of lt-Srac and Sham rats were also evaluated. lt-Srac attenuated the contractions of ANG II and phenylephrine in the aortas in an endothelium-independent manner. However, lt-Srac did not influence the transient contractions induced in endothelium-denuded aortic rings by ANG II, phenylephrine, or caffeine in Ca²⁺-free medium or the subsequent tonic constrictions induced by the addition of Ca²⁺ in the absence of agonists. Thus, the contractions induced by Ca²⁺ release from intracellular stores and Ca²⁺ influx through stored-operated channels were not inhibited in the aortas of lt-Srac rats. Potassium-elicited contractions in endothelium-denuded aortic rings of lt-Srac rats remained unaltered compared with control tissues. Consequently, the contractile depression observed in aortic tissues of lt-Srac rats cannot be explained by direct inhibition of voltage-operated Ca²⁺ channels. Interestingly, 12-O-tetradecanoylphorbol-13-acetate-induced contractions in endothelium-denuded aortic rings of lt-Srac rats were depressed in the presence but not in the absence of extracellular Ca²⁺. Neither levels of angiotensins nor of AT₂R were modified in the aortas after lt-Srac. The results suggest that, in rat thoracic aortas, lt-Srac selectively inhibited protein kinase C-mediated activation of contraction that is dependent on extracellular Ca²⁺ entry.

Relación del índice de masa corporal y el porcentaje de grasa corporal en jóvenes venezolanos

El índice masa corporal (IMC) es uno de los criterios mayormente utilizados para definir la obesidad en la población infantil. No obstante, el mismo determina el estado nutricional, mientras que el total de la grasa corporal demarca su composición corporal. Por lo tanto, el objetivo general del estudio fue determinar la relación entre el índice de masa corporal y el porcentaje de grasa corporal en 505 estudiantes (242 del sexo femenino y 263 masculino) de un Liceo Bolivariano del estado Barinas, con edades comprendidas entre 10 y 20 años. La investigación se enmarcó en el enfoque cuantitativo, con un tipo de investigación de campo, basado en un diseño no experimental, de nivel descriptivo-correlacional y de corte transversal. El análisis de datos se realizó a través del software estadístico SPSS versión 17.0. Los resultados presentan una correlación alta entre el IMC y el porcentaje de grasa (r: 0,75** para las chicas y r: 0,77** para los chicos; p<0,01). Asimismo, se presentaron correlaciones altas y significativas en los diferentes grupos de edad para ambos sexos. Para el masculino G1: r: 0,81, p<0,01; G2: r: 0,82**, p<0,01 y G3: r: 0,66**, p<0,01. En el caso del femenino la relación fue G1: r: 0,72**; G2: r: 0,83** y G3: r: 0,81**, p<0,01. Se concluye de esta manera que existe alta correlación positiva entre el IMC y el porcentaje de grasa corporal en la Institución Educativa mencionada, por lo tanto se considera la utilización del IMC como una herramienta aplicable para la estimación del estado nutricional. 

Induction of endoplasmic reticulum stress impairs insulin-stimulated vasomotor relaxation in rat aortic rings: role of endothelin-1

Sustained endoplasmic reticulum (ER) stress and thus activation of the unfolded protein response is now thought to be the foundation of various chronic disorders including whole-body insulin resistance and cardiovascular disease. The purpose of the present study was to test the hypothesis that ER stress impairs insulin-stimulated vasomotor reactivity. We report that experimental induction of ER stress in isolated aortic rings with tunicamycin (20 μg/mL), a well-established inducer of ER stress, resulted in insulin-stimulated vascular contraction (-78±21% at 1000 μIU/mL; -100±27% at 10,000 μIU/mL; all p<0.05) rather than relaxation (+23±7% at 1000 μIU/mL; +43±8% at 10,000 μIU/mL; all p<0.05). Importantly, we found that insulin-stimulated vascular contraction as a result of ER stress was largely eliminated in the presence of tezosentan (3 μM), a nonselective endothelin-1 (ET-1) receptor blocker (+1±14% at 1000 μIU/mL; +8±17% at 10,000 μIU/mL). Similarly, inhibition of ET-1 receptors fully restored the impairment of acetylcholine-mediated relaxation induced by ER stress (maximal relaxation: control = 94±2%, tunicamycin = 76±5%, tunicamycin + tezosentan = 90±3). Furthermore, we demonstrate that ER stress caused a ≈20-fold greater release of ET-1 from aortic endothelial cells under basal conditions as well as a ≈15-fold increase under insulin-stimulated conditions (p<0.05). This ER stress-mediated up-regulation in ET-1 release from endothelial cells was accompanied by a ≈3-fold increase in phosphorylation of p44/22 MAPK (p<0.05), a known pathway by which insulin signaling activates ET-1. Together, these findings support the hypothesis that vascular ER stress-mediated activation of ET-1 may be an underlying cause of impaired vasomotor responsiveness to insulin and endothelial dysfunction.

Political borders as scientific barriers in general practice. Portugal and Spain as a case study

INTRODUCTION

Borders do not only mean the existence of limits, but also of barriers. For example, despite the cultural and geographic proximity, there seems to be a considerable lack of awareness and ignorance among Portuguese and Spanish GP's of their Iberian neighbour's scientific production, particularly among the Spanish side, which is biased towards the work and publications of authors from Anglo-Saxon and Northern European countries.

METHODS

The authors thus carried out an analysis of the last 12 issues of both the Portuguese and Spanish General Practice flagship journals, counting back from the last issue of 2008.

RESULTS

The authors found out that only 3% of the citations in the Portuguese journal were from Spanish authors, and there were no citations of Portuguese authors in the Spanish journal.

CONCLUSION

These results highlight an important and common problem in Europe, namely the lack of awareness of the primary care reality in two neighbouring European countries, which results in low levels of scientific exchange, and few joint meetings and publications.

Postprandial lipaemia, oxidative stress and endothelial function: a review

AIMS

Postprandial lipaemia-induced endothelial dysfunction is felt to be mediated by increases in oxidative stress. In this review, we have examined the cross-sectional relationships found among these three variables.

METHODS

We found 20 studies conducted by 16 independent investigative teams through a Medline search from 1980 to 2008; studies were required to report correlations between at least two of the three variables of interest in studies of humans. This review is divided into (i) discussions on the biomarkers and other measures of postprandial lipaemia, oxidative stress and endothelial function; (ii) associations reported among the three variables; and (iii) other considerations including alternative intervention studies.

RESULTS

Triglycerides and free fatty acids are robust and well-standardised biomarkers of lipaemia. Measures of oxidative stress ranged from electron spin techniques to measures of lipid peroxidation and are limited by lack of standardisation. Brachial artery flow-mediated dilatation is the most commonly used measure of endothelial function. The associations between postprandial lipaemia and oxidative stress and between postprandial lipaemia and endothelial function are strong and consistent. However, the association between postprandial oxidative stress and endothelial function appears weak, at least using current approaches to measurement of oxidative stress.

DISCUSSION AND CONCLUSIONS

These observations are consistent with the proposed concept that oxidative stress mediates the adverse effects of postprandial lipaemia on endothelial function; they are limited by the difficulties in measuring oxidative stress. Efforts directed at optimising and standardising the measurement of oxidative stress will be of value in future works in this area.

Hepatocellular carcinoma and liver transplantation: a 12-year experience

BACKGROUND

Orthotopic liver transplantation (OLT) for patients with cirrhosis and concomitant hepatocellular carcinoma (HCC) in early stages is the treatment of choice, with an acceptable recurrence rate and excellent survival.

AIM

We sought to evaluate (1) the accuracy of preoperative imaging; (2) the impact of pre-OLT treatments on survival and recurrence; and (3) the influence of beyond Milan criteria selection on global outcomes.

METHODS

We studied a cohort of 65 patients with HCC among 300 consecutive OLTs over a single 12-year experience. We analyzed the overall outcomes of survival and recurrence, the accuracy of preoperative diagnosis and staging the influence of neoadjuvant treatment prior to OLT, and the effect on overall outcomes beyond the Milan criteria in our series.

RESULTS

The 65 transplants were performed for HCC, mostly in association with hepatitis C virus and alcoholic cirrhosis with HTP. At a mean follow-up of 40.32 months, the recurrence rate was 5.7% among the 61 HCC confirmed by histopathology. The overall survival was 30.07. Actuarial survivals at 1, 5, and 10 years were 82%, 77%, and 62%, respectively. Six retransplants occurred among the seven graft losses albeit with poor survival after the second graft. Most explants showed low pTNM stages with favorable microscopic features. Preoperative imaging tests failed to achieve an accurate diagnosis in 15.38% of the series. The role of alpha-fetoprotein (AFP) and hepatic biopsy was irrelevant. Unfavorable histopathologic factors predicted a greater recurrence rate, but had no influence on survival. Neither recurrence nor survival were modified by pre-OLT therapy.

CONCLUSIONS

In our series, AFP, hepatic biopsy, and pre-OLT treatment had limited roles. Radiological imaging techniques underestimated HCC staging and lead to a misdiagnosis to an expected degree. Despite these findings, this single institution experience with OLT for HCC showed excellent survivals with a low recurrence rate including cases of patients beyond the Milan criteria.

Electrochromic conducting polymers: optical contrast characterization of chameleonic materials

The optical characterization in the visible wavelength range was obtained for an electrochromic material, poly-3, 4-ethylenedioxy-thiophene (PEDOT), as a function of its redox charge density (charge consumed for the color change between its maximum and minimum absorbance states). The experimental procedure was kept very simple and all the information can be obtained from only one film, including the identification of the maximum achievable contrast for the material. Different films of the electrochromic material were tested in order to check the validity of the predicted values, showing excellent agreement.

Physical functioning in patients with chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) treated with dialysis have reduced levels of physical functioning. Little is known of the physical functioning in patients prior to initiation of renal replacement therapy (RRT). The purpose of the study was 2-fold: (i) to document physical functioning of patients with CKD not requiring RRT, using objective laboratory tests, physical performance measures and self-reported functioning; and (ii) to determine the correlations between these measures of physical functioning and renal function.

METHODS

Thirty-two patients with CKD (mean estimated glomerular filtration rate [eGFR] 29.9 +/- 17.0) were recruited for the study. Subjects completed symptom-limited treadmill test (peak oxygen uptake [VO2peak]), physical performance measures (gait speed, sit-to-stand and 6-minute walk) and the SF-36 Health Status Questionnaire (physical functioning scale [PF] and physical composite scale [PCS]). Descriptive and correlational analyses were performed on the data.

RESULTS

VO2peak (O2 17.8 +/- 6.7 ml/kg body weight per minute), physical performance measures and self-reported functioning were reduced compared with sedentary age-predicted norms. Significant correlations were found between VO2peak and all other physical functioning measures; however, only maximal gait speed and PCS correlated significantly with eGFR.

CONCLUSIONS

Patients with CKD have reduced physical functioning as measured using objective laboratory tests (VO2peak), physical performance measures and self-reported functioning. Given that low physical functioning predicts outcomes in dialysis patients, interventions to maintain or improve physical functioning are warranted prior to initiation of dialysis.

Otocephaly, and pulmonary malformation association: two case reports

Otocephaly is a rare lethal malformation of the first and second branchial arches. We report two infants with otocephaly and failed resuscitation. Both infants had pulmonary malformations: pulmonary hypoplasia and two-lobed right lung. We report these rare associations with a brief review of the literature.

[Use of blood products in patients treated surgically for stage I non-small cell lung cancer]

OBJECTIVE

Retrospective study on the relation between the use of blood products and survival rates in patients treated surgically for stage I non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The study included 856 patients who underwent surgical resection from 1969 to 2000 for stage I NSCLC, classified histologically according to the current guidelines of the Spanish Society of Pulmonary and Thoracic Surgery (SEPAR). Patients who died in the postoperative period were excluded from the study. A series of clinicopathological variables were recorded, including the perioperative use or not of blood products. Descriptive, univariate, and multivariate statistical analyses were performed. Follow up concluded in December of 2003.

RESULTS

One hundred twenty-five patients (14.6%) underwent a perioperative transfusion. A significant association was found between the use of blood products and tumor size (P<.001), pneumectomy (P<.001), and cell type (P<.05). The respective 2, 5, and 10-year survival rates were 78%, 63%, and 54% for the nontransfusion group, and 73%, 59%, and 46% for the transfusion group. Both survival curves were compared and no significant differences were found (P=.23). Multivariate regression analysis included tumor size, patient age, and histologic cell type (squamous cell carcinoma or not); no relation between transfusion and survival was found.

CONCLUSIONS

In our series, we found no difference in survival rates for patients with stage I NSCLC after perioperative blood transfusion.

[Lung transplantation in cystic fibrosis: perioperative mortality]

OBJECTIVE

To determine the incidence and causes of perioperative mortality following lung transplant for cystic fibrosis.

PATIENTS AND METHODS

We analyzed the cases of 57 patients. Fifty-five patients received double lung transplants, 1 received a heart-double lung transplant, and 1 received a combined double lung and liver transplant. Information related to the organ donor, recipient, lung graft, and early postoperative period was gathered. Perioperative mortality was defined as death resulting from anesthesia or surgery regardless of how many days had passed. The Kaplan-Meier method was used to analyze survival. A Cox logistic regression model was used to determine variables affecting mortality.

RESULTS

Survival was 83.7% at 1 year after transplantation, 77.3% at 2 years, and 66.9% at 5 years. Five (8.7%) patients died as a result of anesthesia or surgery. A ratio of PaO2 to inspired oxygen fraction (FiO2) less than 200 mm Hg in the early postoperative period was observed in 8 (14%) patients. Primary graft failure occurred in 4 patients, due to pneumonia in 2 and to biventricular dysfunction in 2. Three of those patients died. Two patients with PaO2/FiO2 greater than 200 mm Hg died after surgery, one from septic shock due to Pseudomonas cepacia and the other from massive cerebral infarction. PaO2/FiO2 upon admission to the recovery care unit was the only variable significantly associated with perioperative mortality in the logistic regression model (P=.0034).

CONCLUSIONS

The only factor significantly related to perioperative mortality in patients receiving transplants for cystic fibrosis was PaO2/FiO2 upon admission to the recovery unit.

[T2N1M0 non-small cell lung cancer: surgery and prognostic factors]

OBJECTIVE

To determine the prognostic factors for the survival in a group of patients operated on for a non-small cell lung cancer classified as T2N1M0.

PATIENTS AND METHODS

Two hundred sixteen patients treated exclusively with surgery were studied. Kaplan-Meier survival and Cox multivariable regression analyses were used.

RESULTS

The overall survival rate was 39.8% at 5 years and 29.9% at 10 years. Sex, age, presence or absence of symptoms, type of resection, number, and location of affected lymph nodes had no effect on survival. Tumor size (P=.04) and histologic type (P=.03) did significantly affect prognosis. Both variables entered into the Cox multivariable regression model.

CONCLUSIONS

Patients operated on for non-small cell lung cancer classified as T2N1M0 have an overall probability of 5-year survival of approximately 40%. However, the prognosis for this group of patients is heterogeneous: in our study it was affected by the histologic type (45.5% for squamous cell and 25% for non-squamous cell cancers) and tumor size (53% for tumors with a diameter of <or=3 cm, 45% for tumors between 3.1 and 5 cm, and 29% for a tumor diameter >5 cm).

[Non-small cell bronchogenic cancer in stage IA: mortality patterns after surgery]

OBJECTIVE

To determine the causes of death in patients treated surgically for nonsmall cell lung cancer (NSCLC) in stage IA and to evaluate the impact on survival of not performing systematic lymph node dissection and of the number of nodes resected.

PATIENTS AND METHODS

The study sample consisted of 156 patients operated on for NSCLC and classified in stage IA according to TNM staging. Only palpable or visible lymph nodes were dissected. Kaplan-Meier survival curves were compared using a log-rank test.

RESULTS

At the end of the study, 85 (54.5%) patients had died, 67 (42.9%) were alive, and 4 (2.5%) were lost to follow up. Twenty-three (14.7%) died from a recurrence of NSCLC: 2 with local tumors (1.2%), 2 with mediastinal node involvement (1.2%), and 19 (12.1%) with distant metastasis. The cause of death was unrelated to NSCLC in 62 (39.7%) cases: 33 (21.1%) had a new tumor, 18 of which were bronchogenic, and 29 (18.5%) had nonmalignant disease. The 5-year survival rate was 81.4%. The rate was 88.9% among patients from whom no lymph nodes were excised and 79.9% among those with node excision, although the difference was not statistically significant (P=.4073).

CONCLUSIONS

Our experience suggests that neither the fact of not performing systematic lymph node dissection nor the number of nodes resected has an impact on survival. A substantial number of patients died of causes unrelated to the NSCLC for which they had been treated.

A risk model for non-small cell lung cancer using clinicopathological variables, angiogenesis and oncoprotein expression

BACKGROUND

The aim of this study was to investigate new prognostic factors, by using a prognostic model, that could help to identify the patient group with the greatest probability of death.

PATIENTS AND METHODS

First, the clinicopathological variables were analyzed. Second, microvessels were immunohistochemically (IHC) stained with factor VIII-related antibody and then counted in the most intense vascularization area or hotspot, using an automatic image analyzer. In addition, biological angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and inducible nitric oxide synthase expression (iNOS) were also studied. Finally, we evaluated the IHC expression of p53 and p21WAF1 tumor supressor proteins.

RESULTS

The significant independent predictors were: tumor size (p=0.0063), angiogenesis (p=0.0271) and p21WAF1 (p=0.0478). Thus, the most important factor was tumor size 2.7462 [95% CI=1.3307-5.6673]. Finally, these variables were included in a risk model, in order to identify the group with the highest associated probability of death.

CONCLUSION

The analysis of several prognostic factors could establish a more accurate patient risk profile.