Mediterranean Diet Prior to Ischemic Stroke and Potential Circulating Mediators of Favorable Outcomes.

Background/Objectives. A Mediterranean diet (MD) has been associated with neuroprotective effects. We aimed to assess the MD's association with stroke prognosis and the potential mediators involved. Methods. Seventy patients with acute anterior circulation ischemic stroke were included. Dietary patterns were evaluated using the MEDAS scale, a food-frequency questionnaire, and a 24 h recall. Circulating biomarkers including insulin resistance (HOMA index), adipokines (resistin, adiponectin, leptin), choline pathway metabolites (TMAO, betaine, choline), and endothelial progenitor cells (EPCs) were measured. Early neurological improvement (ENI) at 24 h, final infarct volume, and functional outcome at 3 months were assessed. Results. Adherence to MD and olive oil consumption were associated with a lower prevalence of diabetes and atherothrombotic stroke, and with lower levels of fasting glycemia, hemoglobinA1C, insulin resistance, and TMAO levels. Monounsaturated fatty acids and oleic acid consumption correlated with lower resistin levels, while olive oil consumption was significantly associated with EPC mobilization. Multivariate analysis showed that higher MD adherence was independently associated with ENI and good functional prognosis at 3 months. EPC mobilization, lower HOMA levels, and lower resistin levels were associated with ENI, a smaller infarct volume, and good functional outcome. Conclusions. MD was associated with better prognosis after ischemic stroke, potentially mediated by lower insulin resistance, increased EPC mobilization, and lower resistin levels, among other factors.

Evaluation of different isotope dilution mass spectrometry strategies for the characterization of naturally abundant and isotopically labelled peptide standards.

Natural abundance and isotopically labelled tryptic peptides are routinely employed as standards in quantitative proteomics. The certification of the peptide content is usually carried out by amino acid analysis using isotope dilution mass spectrometry (IDMS) after the acid hydrolysis of the peptide. For the validation and traceability of the amino acid analysis procedure, expensive certified peptides must be employed. In this work we evaluate different IDMS alternatives which will reduce the amount of certified peptide required for validation of the amino acid analysis procedure. In this context, the characterization of both natural and isotopically labelled synthetic angiotensin I peptides was carried out. First, we applied a fast procedure for peptide hydrolysis based on microwave-assisted digestion and employed two certified peptide reference materials SRM 998 angiotensin I and CRM 6901-b C-peptide for validation of the hydrolysis procedure. The amino acids proline, leucine, isoleucine, valine, tyrosine, arginine and phenylalanine were evaluated for their suitability for peptide certification by IDMS by both liquid chromatography with tandem mass spectrometry (LC-MS/MS) and gas chromatography with mass spectrometry (GC)-MS/MS. Then, natural angiotensin I and 13C1-labelled angiotensin I were synthesized in-house and purified by preparative liquid chromatography. The concentration of the 13C1-labelled angiotensin I peptide was established by reverse IDMS in its native form using SRM 998 angiotensin I as reference. The concentration of the natural synthesized peptide was determined by IDMS both using the 13C1-labelled peptide in its native form and by amino acid analysis showing comparable results. Finally, the synthetic naturally abundant angiotensin I peptide was employed as "in-house" standard for the validation of subsequent peptide characterization procedures. Therefore, the novelty of this work relies on, first, the development of a faster hydrolysis procedure assisted by focused microwaves, providing complete hydrolysis in 150 min, and secondly, a validation strategy combining GC-MS and LC-MS/MS that allowed us to certify the purity of an in-house-synthesized peptide standard that can be employed as quality control in further experiments.

Correction of creatine-creatinine conversion during serum creatinine quantification by two-dimensional liquid chromatography and double-spike isotope dilution tandem mass spectrometry.

BACKGROUND AND AIMS: Development of a candidate reference method based on bidimensional liquid chromatography coupled to ESI-MS/MS and double spike isotope dilution for serum creatinine quantification capable of correcting for creatinine-creatine interconversion during sample pretreatment. Study of the impact of the creatine-creatinine interconversion during the analysis of human serum samples. MATERIALS AND METHODS: 13C1-creatinine and 13C2-creatine are added to the serum sample. Separation carried out by bidimensional liquid chromatography combining reversed phase and a strong cation exchange chromatography. The heart cut, containing creatine and creatinine, is automatically transferred to the second dimension. Quantification carried out by double spike isotope dilution tandem MS/MS. RESULTS: Minimization of spectral interferences and ion suppression due to matrix effects while increasing sample throughput compared to the direct coupling of cation exchange chromatography to the ESI source. Trueness of the method studied with the satisfactory analysis of two certified reference materials. Satisfactory intra- and inter-day precisions obtained analysing a serum pool and control sera. Analysis of 93 serum samples revealed negligible interconversions with no correlation with creatine levels. CONCLUSIONS: The method provides adequate analytical figures of merit for serum creatinine determination according to CSLI guidelines. Negligible creatine-creatinine interconversion is promoted with the applied sample preparation procedure.

Hidatidosis primaria en la mama, una entidad poco frecuente / Breast primary hydatid cyst, a rare entity

La hidatidosis mamaria es una rara entidad, siendo excepcional su foco primario en la mama. Presentamos el caso de una mujer con una tumoración dolorosa palpable en la mama, con hallazgo de numerosos quistes en el estudio mastológico catalogados como BIRADS 3. Se realizó punción aspiración con aguja fina para citología, no concordante con los hallazgos radiológicos. Ante la persistencia de los síntomas, se realizó una exéresis quirúrgica de la lesión, con hallazgos en la biopsia compatibles con una parasitosis. Una serología positiva para Echinococcus granulosus confirmó el diagnóstico de hidatidosis, por lo que se inició el tratamiento postoperatorio con albendazol. Su evolución fue favorable, sin signos de recidiva y asintomática. Aunque poco común y en ocasiones de presentación y hallazgos inespecíficos, el quiste hidatídico debe considerarse como un diagnóstico diferencial potencialmente serio al evaluar cualquier lesión nodular en la mama en las pacientes de áreas endémicas de esta enfermedad o con factores de riesgo. (AU)

Hydatid breast disease is a rare entity, its primary focus in the breast being exceptional. We present the case of a woman with a palpable painful tumor in the breast, with the finding of numerous cysts in a mastological study, classified as BIRADS 3. FNA was performed for cytology, not consistent with radiological findings. Given the persistence of symptoms, a surgical excision of the lesion was performed, with biopsy findings compatible with parasitosis. A positive serology for Echinococcus granulosus confirmed the diagnosis of hydatidosis, for which postoperative treatment with albendazole was started. Its evolution was favorable, without signs of recurrence and asymptomatic. Although uncommon and sometimes with nonspecific presentation and findings, hydatid cyst should be considered as a potentially serious differential diagnosis when evaluating any nodular lesion in the breast in patients from endemic areas of this disease or with risk factors. (AU)

How class cohesion and teachers' relatedness supportive/thwarting style relate to students' relatedness, motivation, and positive and negative outcomes in physical education.

The main goal of this study was to examine the links between class cohesion and teachers' relatedness teaching style with students' relatedness needs, motivation, and positive and negative outcomes in Physical Education. A total of 1294 students 10-18 years old (M = 14.40, SD = 1.99), 613 males (M = 14.48, SD = 1.95) and 681 females (M = 14.33, SD = 2.02), agreed to participate. They were enrolled in 88 classes belonging to 13 different primary and secondary schools in southwestern Spain. The study followed a correlational research design. Results of the multilevel path model showed a positive relationship between teachers' relatedness support and class cohesion and behavioral and emotional engagement through relatedness need satisfaction and autonomous and controlled motivation. Results also showed a positive relationship between teachers' relatedness thwarting and disruptive behaviors and problematic relationships through relatedness need frustration and amotivation. In conclusion, teachers' relatedness behaviors and class cohesion can significantly impact the students' relatedness and motivation, which in turn will affect their engagement and behaviors. A whole cascade of consequences begins with the way teachers teach and the cohesion generated in class. These first steps cannot be overlooked.

Quantification of modified nucleotides and nucleosides by isotope dilution mass spectrometry.

Epigenetic modifications are closely related to certain disorders of the organism, including the development of tumors. One of the main epigenetic modifications is the methylation of DNA cytosines, 5-methyl-2'-deoxycycytidine. Furthermore, 5-mdC can be oxidized to form three new modifications, 5-(hydroxymethyl)-2'-deoxycytidine, 5-formyl-2'-deoxycytidine, and 5-carboxy-2'-deoxycytidine. The coupling of liquid chromatography with tandem mass spectrometry has been widely used for the total determination of methylated DNA cytosines in samples of biological and clinical interest. These methods are based on the measurement of the free compounds (e.g., urine) or after complete hydrolysis of the DNA (e.g., tissues) followed by a preconcentration, derivatization, and/or clean-up step. This review highlights the main advances in the quantification of modified nucleotides and nucleosides by isotope dilution using isotopically labeled analogs combined with liquid or gas chromatography coupled to mass spectrometry reported in the last 20 years. The different possible sources of labeled compounds are indicated. Special emphasis has been placed on the different types of chromatography commonly used (reverse phase and hydrophilic interaction liquid chromatography) and the derivatization methods developed to enhance chromatographic resolution and ionization efficiency. We have also revised the application of bidimensional chromatography and indicated significant biological and clinical applications of these determinations.

Influence of Post-Processing on the Properties of Multi-Material Parts Obtained by Material Projection AM.

The great geometric complexity that additive manufacturing allows in parts, together with the possibility of combining several materials in the same part, establishes a new design and manufacturing paradigm. Despite the interest of many leading sectors, the lack of standardization still makes it necessary to carry out characterization work to enjoy these advantages in functional parts. In many of these techniques, the process does not end with the end of the machine cycle, but different post-processing must be carried out to consider the part finished. It has been found that the type of post process applied can have a similar effect on part quality as other further studied process parameters. In this work, the material projection technique was used to manufacture multi-material parts combining resins with different mechanical properties. The influence of different post-processing on the tensile behavior of these parts was analyzed. The results show the detrimental effect of ultrasonic treatment with isopropyl alcohol in the case of the more flexible resin mixtures, being advisable to use ultrasonic with mineral oil or furnace treatment. For more rigid mixtures, the furnace is the best option, although the other post-processing techniques do not significantly deteriorate their performance.

Determination of methylmercury and inorganic mercury in human hair samples of individuals from Colombian gold mining regions by double spiking isotope dilution and GC-ICP-MS.

With the aim to distinguish between routes of exposition to mercury (Hg) in artisanal and small-scale gold mining (ASGM) communities and to distinguish between Hg contamination sources, Hg species composition should be performed in human biomarkers. In this work, Hg species-specific determination were determined in human hair samples (N = 96), mostly non-directly occupied in ASGM tasks, from the six most relevant gold mining Colombian regions. Therefore, MeHg, Hg(II) and THg concentrations were simultaneously determined by double spiking species-specific isotope dilution mass spectrometry (IDMS) and GC-ICP-MS. Only 16.67% of participants were involved at some point in AGSM works and fish consumption ranged from 3 to 7 times/week, which is between medium and high intake levels. The median concentration of THg obtained from all samples is higher than the reference dose weekly acceptable of MeHg intake established by the EPA (1 ppm), whereas a 25% were more than 4 times higher than the WHO level (2.2 µg Hg g-1). Median THg value of individuals consuming fish 5-7 times per week was significantly higher (p < 0.05) than those of the other consuming groups (12.5 µg Hg g-1). Most of the samples presented a % of MeHg relative to THg higher than 80%. The average % of Hg(II)/THg was 11% and only 10 individuals presented a Hg(II) content over 30%. No significant differences (p > 0.05) were found when the amount of Hg(II) was compared between people involved in AGSM task and people not involved. Interestingly, significant differences among the evaluated groups where found when the percentage of the Hg(II)/THg ratio of these groups were compared. In fact, people involved in AGSM tasks showed 1.7 times higher Hg(II)/THg vs. inhabitants uninvolved. This suggest that Hg(II) determination by IDMS-GC-ICP-MS could be a good proxy for evaluating Hg(II) adsorption by direct exposure to mercury vapors onto hair.

Development and evaluation of an electrochemical biosensor for creatinine quantification in a drop of whole human blood.

An electrochemical biosensor for creatinine determination in a drop of whole human blood was developed and applied to the determination of creatinine in real clinical samples. It is based on the modification of a dual carbon working electrode with a combination of three enzymes: creatinine amidohydrolase (CNN), creatine amidinohydrolase (CRN) and sarcosine oxidase (SOX). Electrochemical transduction is performed using horseradish peroxidase (HRP) and potassium hexacyanoferrate(II) as mediator. A drop of human blood is enough to carry out the measurements by differential chronoamperometry where one carbon electrode detects creatine and the other both creatine and creatinine. The integrated differential signal obtained in the biosensor is linear with the concentration of creatinine in blood in the range 0.5-15 mg/dL and the enzyme-modified electrodes are stable for at least 3 months at 4 °C. The biosensor was lined to a reference method based on Isotope Dilution Mass Spectrometry (IDMS) with 50 real human blood samples and the results compared with those obtained by alternative routine techniques based on Jaffé method and an enzymatic method (Cobas 8000 Roche®, Crep2 Roche®). There were no significant differences between the creatinine concentrations found by the routine techniques and the developed biosensor.

Comparison between one and two-dimensional liquid chromatographic approaches for the determination of plasmatic stroke biomarkers by isotope dilution and tandem mass spectrometry.

This work presents the evaluation of one- and two-dimensional liquid chromatography for the quantification of three stroke outcome predictors in plasma. Isotopically labelled analogues of L-arginine (L-Arg), asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) are used to quantify the three analytes by isotope dilution and tandem mass spectrometry. Chromatographic isotope effects were not observed between natural L-Arg and its 15N-labelled analogue but they were observed between natural ADMA and SDMA and their multiple deuterated analogues. Under these conditions, bidimensional chromatography through the use of an automated multiple heart cutting mode provided unsatisfactory results for ADMA and SDMA due to the different amounts of natural and labelled compounds transferred from the first to the second chromatographic dimension. In contrast, using one dimensional liquid chromatography after a derivatization step to esterify carboxylic groups, chromatographic isotope effects did not alter the initial mass balance as full coelution of natural and labelled analogues or baseline resolution between the analytes was not required. This method was successfully validated following the Clinical & Laboratory Standards Institute guidelines and applied to the analysis of plasma samples from patients who had suffered from an intraparenchymal haemorrhagic stroke.