Comparative evaluation of the susceptibility of neuronal (N1E-115) and non-neuronal (HeLa) cells to acetylsalicylic acid (ASA) cytotoxicity by confocal microscopy

A voltage-sensitive probe, tetramethylrhodamine methyl ester (TMRM) and digital imaging (confocal microscopy) were used to quantify differential membrane potential alteration in neuronal (murine neuroblastoma, N1E-115) and non-neuronal (human epithelial-like, HeLa) cells, after 1 and 24 hr of exposure to a knownin vivo neurotoxic agent, acetylsalicylic acid (ASA), as a first step in substantiating the relevance of alteration in resting membrane potential (V(m)) as a neurotoxic endpoint. After 1 hr of exposure, ASA (5.0 mm) hyperpolarized both HeLa and N1E-115 cells. V(m) decreased from -57.6mV+/- 2.8 (n= 20cells)to-74.7mV+/- 1.9 (n= 20cells) and from -64.0mV+/- 2.1 (n= 20cells)to-82.5mV+/- 3.4 (n= 20cells) for HeLa and N1E-115 cells, respectively. The extent of hyperpolarization was found to be ASA concentration dependent. There was no significant difference (P < 0.05) between the cell lines with respect to ASA sensitivity, suggesting that under these experimental conditions, ASA exhibited no selective cytotoxic activity for the neuronal cells. In comparison with control cultures, 24-hr ASA (5.0 mm) exposure did not affect the surviving cell V(m). The results of the present study were inconclusive with respect to the suitability of V(m) alteration as an indicator of neurotoxic potential.

Potassium starvation induces oxidative stress in Solanum lycopersicum L. roots

The relationship between potassium deficiency and the antioxidative defense system has received little study. The aim of this work was to study the induction of oxidative stress in response to K(+) deficiency and the putative role of antioxidants. The tomato plants were grown in hydroponic systems to determine the role of reactive oxygen species (ROS) in the root response to potassium deprivation. Parameters of oxidative stress (malondialdehyde and hydrogen peroxide (H(2)O(2)) concentration), activities of antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)) and antioxidant molecules (ascorbate (ASC) and glutathione) were investigated. H(2)O(2) was subcellularly located by laser confocal microscopy after potassium starvation in roots. During the first 24h, H(2)O(2) induced the cascade of the cellular response to low potassium, and ROS accumulation was located mainly in epidermal cells in the elongation zone and meristematic cells of the root tip and the epidermal cells of the mature zones of potassium starved roots. The activity of the antioxidative enzymes SOD, peroxidase and APX in potassium deprivation significantly increased, whereas CAT and DHAR activity was significantly depressed in the potassium starvation treatment compared to controls. GR did not show significant differences between control and potassium starvation treatments. Based on these results, we put forward the hypothesis that antioxidant molecule accumulations probably scavenge H(2)O(2) and might be regenerated by the ASC-glutathione cycle enzymes, such as DHAR and GR.

Clinical validation of the European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE) II criteria in an open-access unit: a prospective study

BACKGROUND AND STUDY AIMS

The European Panel on the Appropriateness of Gastrointestinal Endoscopy (EPAGE I) criteria were recently updated (EPAGE II), but no prospective studies have used these criteria in clinical practice. The aim of the current study was to validate the EPAGE II criteria in an open-access endoscopy unit.

PATIENTS AND METHODS

A prospective observational study was conducted in an open-access endoscopy unit at a tertiary care referral center. Consecutive outpatients (n = 1004; mean age 58.9 ± 13.1 years; 45 % men) were referred for diagnostic colonoscopy between September 2009 and February 2010. The appropriateness of colonoscopy was assessed based on EPAGE II criteria, and the relationship between appropriateness and both referral doctor and detection of significant lesions was examined. The effectiveness of EPAGE II criteria in assessing appropriateness was measured by means of sensitivity, specificity, and positive and negative predictive values for detecting significant lesions.

RESULTS

Colonoscopic cecal intubation was achieved in 956 patients (95.2 %). Most referral doctors were gastroenterologists (58.0 %) and the most common indication was colorectal cancer (CRC) screening (35.2 %). EPAGE II criteria were applicable in 968 patients (96.4 %); of these patients, the indication was appropriate in 778 (80.4 %), inappropriate in 102 (10.5 %), and uncertain in 88 (9.1 %). Patients with appropriate or uncertain indications based on EPAGE II criteria had more relevant endoscopic findings than those with inappropriate indications (38.8 % vs. 24.5 %; OR 1.95, 95 %CI 1.22 - 3.13; P < 0.005). Sensitivity and negative predictive value of EPAGE II criteria for detecting significant lesions were 93.1 % (95 %CI 90 % - 96 %) and 75.5 % (95 %CI 67 % - 84 %), respectively, whereas for advanced neoplastic lesions these values were 98.0 % (95 %CI 95 % - 100 %) and 98.0 % (95 % CI 95 % - 100 %), respectively. Adherence to EPAGE II recommendations was an independent predictor of finding a significant lesion (OR 1.93, 95 %CI 1.20 - 3.11; P = 0.007).

CONCLUSIONS

EPAGE II is a simple, valid score for detecting inappropriate colonoscopies in clinical practice.

Neural bases of language switching in high and early proficient bilinguals

The left inferior frontal cortex, the caudate and the anterior cingulate have been proposed as the neural origin of language switching, but most of the studies were conducted in low proficient bilinguals. In the present study, we investigated brain areas involved in language switching in a sample of 19 early, high-proficient Spanish-Catalan bilinguals using a picture naming task that allowed contrasting switch and non-switch trials. Compared to the non-switching condition, language switching elicited greater activation in the head of the left caudate and the pre-SMA/ACC. When the direction of the switching was considered, the left caudate was more associated with forward switching and the pre-SMA/ACC with backward switching. The discussion is focused on the relevance of these brain structures in language control in early, high-proficient bilinguals, and the comparison with previous results in late bilinguals.

Changes to the proteome and targeted metabolites of xylem sap in Brassica oleracea in response to salt stress

Root-to-shoot signalling via xylem sap is an important mechanism by which plants respond to stress. This signalling could be mediated by alteration in the concentrations of inorganic and/or organic molecules. The effect of salt stress on the contents of xylem sap in Brassica olarecea has been analysed by mass spectrometry in order to quantify these changes. Subcellular location of arabinogalactan proteins (AGPs) by immunogold labelling and peroxidase isozymes was also analysed by isoelectrofocusing. The xylem sap metabolome analysis demonstrated the presence of many organic compounds such as sugars, organic acids and amino acids. Of these, amino acid concentrations, particularly that of glutamine, the major amino acid in the sap, were substantially reduced by salt stress. The xylem sap proteome analysis demonstrated the accumulation of enzymes involved in xylem differentiation and lignification, such as cystein proteinases, acid peroxidases, and a putative hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase under salt stress. The peroxidase isozyme pattern showed that salt stress induced a high accumulation of an acid isoform. These results suggest that xylem differentiation and lignification is induced by salt stress. The combination of different methods to analyse the xylem sap composition provides new insights into mechanisms in plant development and signalling under salt stress.

Antipsychotic injectable treatment in patients with involuntary ambulatory treatment

Introduction

Involuntary Ambulatory Treatment (IAT) is a judicial measure existing in Spain. Its aim is to ensure the adherence to treatment of seriously ill patients, with poor insight and repeated hospitalization. This is done by means of the regular and involuntary administration of antipsychotic intramuscular medication.

Objectives

To assess the treatment used in patients undergoing IAT in a local clinic, to assess the type of medicaments and their dosage and to verify adherence to treatment and evolution.

Material and method

A revision was made of the clinical backgrounds of all the patients of a psychiatric outpatient clinic who have been submitted to IAT (n = 37). A note was made of socio-demographic variables as well as psychiatric diagnoses according to DSM-IV-TR criteria and the number of hospitalizations and treatments used.

Results

All but one patient had been hospitalized and average of 3.53 times before IAT. Since undergoing IAT only 6 patients have been admitted (16%). Four of them relapsed having abandoned treatment.

In seven cases (19%) the patients gained insight and the antipsychotic treatment was changed from injectable to oral treatment at the patients’ request. In these cases IAT was ceased.

The antipsychotic prescribed in 59% of the cases was Long-Acting Injectable Risperidone. This percentage was higher in non- schizophrenic patients (84%).

Conclusions

In our environment IAT could be an effective tool for severe patients with nil insight, since it can bring about an improvement in treatment adherence and evolution, as well as insight.

Epigenetic alterations in disseminated neuroblastoma tumour cells: influence of TMS1 gene hypermethylation in relapse risk in NB patients

PURPOSE

Most neuroblastoma patients over 18 months of age at diagnosis present disseminated disease. The presence of neuroblastoma cells in bone marrow can be used to evaluate the response to treatment. It is possible that alterations in certain tumour cells might confer a selective advantage over tumour dissemination process, and probably be helpful in the clonal selection of tumour-specific cells that could originate metastasis.

METHODS

We performed real-time quantitative PCR to identify the presence of disseminated tumour cells in bone marrow samples, and we used MSP to analyse the methylation profile of 20 genes putatively implied in dissemination.

RESULTS

We described epigenetic alterations in the methylated status of certain genes in disseminated tumour cells from bone marrow. Those cases with high rate of hypermethylation showed an increased probability of relapse during or after treatment. We found significantly poor prognosis in event-free survival in cases with hypermethylation of TMS1, MGMT and RARbeta2 genes.

CONCLUSION

We could not confirm the presence of a specific methylation profile in disseminated neuroblastoma tumour cells, but a high accumulation of epigenetic events in those cells is associated with a high risk of relapse, independently of MYCN amplification.