Nanostructured material-based electrochemical sensing of oxidative DNA damage biomarkers 8-oxoguanine and 8-oxodeoxyguanosine: a comprehensive review.

Oxidative DNA damage plays an important role in the pathogenesis of various diseases. Among oxidative DNA lesions, 8-oxoguanine (8-oxoG) and its corresponding nucleotide 8-oxo-2'-deoxyguanosine (8-oxodG), the guanine and deoxyguanosine oxidation products, have gained much attention, being considered biomarkers for oxidative DNA damage. Both 8-oxoG and 8-oxodG are used to predict overall body oxidative stress levels, to estimate the risk, to detect, and to make prognosis related to treatment of cancer, degenerative, and other age-related diseases. The need for rapid, easy, and low-cost detection and quantification of 8-oxoG and 8-oxodG biomarkers of oxidative DNA damage in complex samples, urine, blood, and tissue, caused an increasing interest on electrochemical sensors based on modified electrodes, due to their high sensitivity and selectivity, low-cost, and easy miniaturization and automation. This review aims to provide a comprehensive and exhaustive overview of the fundamental principles concerning the electrochemical determination of the biomarkers 8-oxoG and 8-oxodG using nanostructured materials (NsM), such as carbon nanotubes, carbon nanofibers, graphene-related materials, gold nanomaterials, metal nanoparticles, polymers, nanocomposites, dendrimers, antibodies and aptamers, and modified electrochemical sensors.

DNA Electrochemical Biosensors for In Situ Probing of Pharmaceutical Drug Oxidative DNA Damage.

Deoxyribonucleic acid (DNA) electrochemical biosensors are devices that incorporate immobilized DNA as a molecular recognition element on the electrode surface, and enable probing in situ the oxidative DNA damage. A wide range of DNA electrochemical biosensor analytical and biotechnological applications in pharmacology are foreseen, due to their ability to determine in situ and in real-time the DNA interaction mechanisms with pharmaceutical drugs, as well as with their degradation products, redox reaction products, and metabolites, and due to their capacity to achieve quantitative electroanalytical evaluation of the drugs, with high sensitivity, short time of analysis, and low cost. This review presents the design and applications of label-free DNA electrochemical biosensors that use DNA direct electrochemical oxidation to detect oxidative DNA damage. The DNA electrochemical biosensor development, from the viewpoint of electrochemical and atomic force microscopy (AFM) characterization, and the bottom-up immobilization of DNA nanostructures at the electrode surface, are described. Applications of DNA electrochemical biosensors that enable the label-free detection of DNA interactions with pharmaceutical compounds, such as acridine derivatives, alkaloids, alkylating agents, alkylphosphocholines, antibiotics, antimetabolites, kinase inhibitors, immunomodulatory agents, metal complexes, nucleoside analogs, and phenolic compounds, which can be used in drug analysis and drug discovery, and may lead to future screening systems, are reviewed.

Calcium channel blocker lercanidipine electrochemistry using a carbon black-modified glassy carbon electrode.

Lercanidipine, a third-generation dihydropyridine calcium L-type channel blocker, redox behavior at different carbon electrode materials, in a wide pH range, using cyclic, square-wave, and differential pulse voltammetry, was studied. A comparison was made between unmodified glassy carbon electrode (GCE) and boron-doped diamond electrode (BDDE), and GCE and BDDE modified with a carbon black (CB) nanoparticle embedded within a dihexadecylphosphate (DHP) nanostructured film (CB-DHP/GCE and CB-DHP/BDDE). Lercanidipine oxidation, for 3.4 < pH < 9.5, is an irreversible, diffusion-controlled, pH-dependent process that occurs in two consecutive steps, with the transfer of one electron and one proton, at the N1 and C4 positions in the 1,4-dihydropyridine ring. For pH > 9.5, both oxidation processes are pH-independent and a pKa = 9.40 was determined. Lercanidipine reduction at pH = 7.0 is an irreversible process, and the lercanidipine reduction products are electroactive and follow a reversible electron transfer reaction. Lercanidipine electroanalytical determination, at a nanostructured GCE modified with a CB-DHP film (CB-DHP/GCE), with no need for N2 purging, with a detection limit of 0.058 µM (3.58 × 10-5 g L-1) and a quantification limit of 0.176 µM (1.08 × 10-4 g L-1), was achieved. Graphical abstract.

Natural phenolic antioxidants electrochemistry: Towards a new food science methodology.

Natural phenolic compounds are abundant in the vegetable kingdom, occurring mainly as secondary metabolites in a wide variety of chemical structures. Around 10,000 different plant phenolic derivatives have been isolated and identified. This review provides an exhaustive overview concerning the electron transfer reactions in natural polyphenols, from the point of view of their in vitro antioxidant and/or pro-oxidant mode of action, as well as their identification in highly complex matrixes, for example, fruits, vegetables, wine, food supplements, relevant for food quality control, nutrition, and health research. The accurate assessment of polyphenols' redox behavior is essential, and the application of the electrochemical methods in routine quality control of natural products and foods, where the polyphenols antioxidant activity needs to be quantified in vitro, is of the utmost importance. The phenol moiety oxidation pathways and the effect of substituents and experimental conditions on their electrochemical behavior will be reviewed. The fundamental principles concerning the redox behavior of natural polyphenols, specifically flavonoids and other benzopyran derivatives, phenolic acids and ester derivatives, quinones, lignins, tannins, lignans, essential oils, stilbenes, curcuminoids, and chalcones, will be described. The final sections will focus on the electroanalysis of phenolic antioxidants in natural products and the electroanalytical evaluation of in vitro total antioxidant capacity.

Amyloid Beta Peptide VHHQ, KLVFF, and IIGLMVGGVV Domains Involved in Fibrilization: AFM and Electrochemical Characterization.

The time-dependent structural modifications and oxidation behavior of specifically chosen five short amyloid beta (Aß) peptides, Aß1-16, Aß1-28, Aß10-20, Aß12-28, and Aß17-42, fragments of the complete human Aß1-40 peptide, were investigated by atomic force microscopy (AFM) and voltammetry. The objective was to determine the influence of different Aß domains (VHHQ that contains electroactive histidine H residues, KLVFF that is the peptide hydrophobic aggregation core, and IIGLMVGGVV that is the C-terminus hydrophobic region), and of Aß peptide hydrophobicity, in the fibrilization mechanism. The short Aß peptides absence of aggregation or the time-dependent aggregation mechanisms, at room temperature, in free chloride media, within the time window from 0 to 48 h, were established by AFM via changes in their adsorption morphology, and by differential pulse voltammetry, via modifications of the amino acid residues oxidation peak currents. The first oxidation peak was of tyrosine Y residue and the second peak was of histidine H and methionine M residues oxidation. A correlation between the presence of an intact highly hydrophobic KLVFF aggregation core and the time-dependent changes on the Aß peptides aggregation was found. The hydrophobic C-terminal domain IIGLMVGGVV, present in the Aß1-40 peptide, also contributed to accelerate the formation of Aß1-40 peptide aggregates and fibrils.

Atomic Force Microscopy and Voltammetric Investigation of Quadruplex Formation between a Triazole-Acridine Conjugate and Guanine-Containing Repeat DNA Sequences.

The interactions of the Tetrahymena telomeric repeat sequence d(TG4T) and the polyguanylic acid (poly(G)) sequence with the quadruplex-targeting triazole-linked acridine ligand GL15 were investigated using atomic force microscopy (AFM) at a highly oriented pyrolytic graphite and voltammetry at a glassy carbon electrode. GL15 interacted with both sequences, in a time dependent manner, and G-quadruplex formation was detected. AFM showed the adsorption of quadruplexes as small d(TG4T) and poly(G) spherical aggregates and large quadruplex-based poly(G) assemblies, and voltammetry showed the decrease and disappearance of GL15 and guanine oxidation peak currents and appearance of the G-quadruplex oxidation peak. The GL15 molecule strongly stabilized and accelerated G-quadruplex formation in both Na(+) and K(+) ion-containing solution, although only K(+) promoted the formation of perfectly aligned tetra-molecular G-quadruplexes. The small-molecule complex with the d(TG4T) quadruplex is discrete and approximately globular, whereas the G-quadruplex complex with poly(G) is formed at a number of points along the length of the polynucleotide, analogous to beads on a string.

Quadruplex nanostructures of d(TGGGGT): influence of sodium and potassium ions.

The Tetrahymena telomeric repeat sequence d(TG4T) contains only guanine (G) and thymine (T) bases and has medical and nanotechnological applications because of its ability to self-assemble into stiff tetra-molecular parallel-stranded G-quadruplexes. The hexadeoxynucleotide d(TG4T) was studied using atomic force microscopy (AFM) on the highly oriented pyrolytic graphite surface and differential pulse (DP) voltammetry at a glassy carbon electrode. The d(TG4T) single-strands self-assembled into G-quadruplex structures, very fast in K(+) ions solution and slowly in Na(+) ions containing solution. The G-quadruplex structures were detected in AFM by the adsorption of small spherical aggregates and by DP voltammetry by the G oxidation peak decrease and G-quartets oxidation peak occurrence, in a time and K(+) ions concentration dependent manner. In the presence of Na(+) ions, the d(TG4T) single-strands also slowly self-assembled into higher-order nanostructures, detected by AFM as short nanowires and nanostructured films that were never observed in K(+) ions containing solution.

In situ electrochemical evaluation of anticancer drug temozolomide and its metabolites-DNA interaction.

Temozolomide (TMZ) is an antineoplastic alkylating agent with activity against serious and aggressive types of brain tumours. It has been postulated that TMZ exerts its antitumor activity via its spontaneous degradation at physiological pH. The in vitro evaluation of the interaction of TMZ and its final metabolites, 5-aminoimidazole-4-carboxamide (AIC) and methyldiazonium ion, with double-stranded DNA (dsDNA) was studied using differential pulse voltammetry at a glassy carbon electrode. The DNA damage was electrochemically detected following the changes in the oxidation peaks of guanosine and adenosine residues. The results obtained revealed the decrease of the dsDNA oxidation peaks with incubation time, showing that TMZ and AIC/methyldiazonium ion interact with dsDNA causing its condensation. Furthermore, the experiments of the in situ TMZ and AIC/methyldiazonium ion-dsDNA interaction using the multilayer dsDNA-electrochemical biosensor confirmed the condensation of dsDNA caused by these species and showed evidence for a specific interaction between the guanosine residues and TMZ metabolites, since free guanine oxidation peak was detected. The oxidative damage caused to DNA bases by TMZ metabolites was also detected electrochemically by monitoring the appearance of the 8-oxoguanine/2,8-dyhydroxyadenine oxidation peaks. Nondenaturing agarose gel electrophoresis of AIC/methyldiazonium ion-dsDNA samples confirmed the occurrence of dsDNA condensation and oxidative damage observed in the electrochemical results. The importance of the dsDNA-electrochemical biosensor in the in situ evaluation of TMZ-dsDNA interactions is clearly demonstrated.

Self-assembled G-quadruplex nanostructures: AFM and voltammetric characterization.

G-rich oligodeoxynucleotides (ODNs) have great medical and nanotechnological potential, because they can self-assemble into G-quadruplexes and higher-order nanostructures. The folding properties of d(G)10, d(TG9) and d(TG8T) ODNs were studied using atomic force microscopy (AFM) and voltammetry at carbon electrodes. Single-stranded ODNs, in Na(+) containing solutions and for short incubation times, were detected using AFM as network films and polymeric structures and using voltammetry by the occurrence of only the guanine oxidation peak. G-quadruplexes, in Na(+) containing solutions and long incubation times, or in K(+) containing solutions, were detected using AFM as spherical aggregates and using voltammetry by the decrease of the guanine oxidation peak and the occurrence of the G-quartet oxidation peak. Concerning the self-assembling into higher-order nanostructures, d(G)10 was the only sequence forming G-nanowires observed using AFM, d(TG9) formed short G-based super-structures that adsorbed as rod-like shape aggregates, and d(TG8T) formed no nanostructures, due to the presence of thymine residues at both 5' and 3' ends.

Acute liver failure in under two year-olds--are there markers of metabolic disease on admission?

INTRODUCTION: The early establishment of an etiology for acute liver failure (ALF) in infants is essential for the start of adequate treatment in the shortest timeframe possible. AIM: To identify markers of inherited metabolic disease on admission in children under two years of age with ALF. MATERIAL AND METHODS: A retrospective review of the medical records of all children (< 2 years old) with ALF admitted to the pediatric hepatology or intensive care units of a tertiary center over a twenty-three year period (January 1989 to December 2011) was done. Patients were divided into two groups: with (group A) or without (group B) a metabolic etiology. Clinical and laboratory parameters on admission were compared. RESULTS: Twenty-three children met inclusion criteria. Twelve had ALF of metabolic origin (group A). The median age in this group was 2.25 (Q1-Q3: 0.63-4.65) months and in group B 8.0 (Q1-Q3: 1.5-15) months. History of failure to thrive and/or vomiting was more frequent in group A (p = 0.022). Age, gender, encephalopathy and left ventricular hypertrophy were similar in both groups (p = 0.147, p = 1.000, p = 0.637, p = 1.000, respectively). Laboratory tests on admission (plasma lactate, ammonia, cholesterol, phosphate, INR, glucose, bilirubin, ALT, base excess and the presence of reducing substances in urine) showed no statistically significant differences between groups. CONCLUSION: This study showed that although infants with inborn errors of metabolism showed a trend towards lower age at presentation, the only marker of inherited metabolic disease found on admission was history of vomiting and/or failure to thrive.

Electrochemistry of chemotherapeutic alkylating agents and their interaction with DNA.

Alkylating agents were among the first anticancer drugs to be discovered and continue to be the most commonly used in chemotherapy. They are electrophiles that react with the ring nitrogen and extracyclic oxygen atoms of DNA bases, forming covalent adducts that further lead to cross-linking of DNA strands, abnormal base pairing or DNA strand breaks. The investigation and quantitative analysis of alkylating agents in biological samples are essential for monitoring the therapy progression and efficiency, understanding their pharmacokinetics and develop new more effective and specific chemotherapeutical drugs. Among biotechnological methods, electrochemical techniques are particularly important in pharmaceutical medicine, owing to their rapid detection, great sensitivity, robustness, exceptional detection limits, ability to be used with small analyte volumes in turbid biofluids, and easy adaptability to miniaturization and point-of-care (POC) testing. This article provides first an exhaustive review concerning the electrochemical methods of characterization and quantification of different classes of chemotherapeutic alkylating agents (triazenes and hydrazines, nitrosoureas, nitrogen mustards, oxazaphosphorines, alkyl alkane sulfonates and ethylene imines) in standard samples, pharmaceutical formulations and biological matrixes. The second part of the article focuses on the recent electrochemical methodologies and DNA-electrochemical biosensors developed to study the interaction of alkylating agents with DNA. These studies are relevant for obtaining real-time details about the alkylating agents' mechanism of action and for assessing the oxidative DNA damage they cause, important for the development of improved antineoplastic drugs.

Policies on children and schools during the SARS-CoV-2 pandemic in Western Europe.

During the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), mitigation policies for children have been a topic of considerable uncertainty and debate. Although some children have co-morbidities which increase their risk for severe coronavirus disease (COVID-19), and complications such as multisystem inflammatory syndrome and long COVID, most children only get mild COVID-19. On the other hand, consistent evidence shows that mass mitigation measures had enormous adverse impacts on children. A central question can thus be posed: What amount of mitigation should children bear, in response to a disease that is disproportionally affecting older people? In this review, we analyze the distinct child versus adult epidemiology, policies, mitigation trade-offs and outcomes in children in Western Europe. The highly heterogenous European policies applied to children compared to adults did not lead to significant measurable differences in outcomes. Remarkably, the relative epidemiological importance of transmission from school-age children to other age groups remains uncertain, with current evidence suggesting that schools often follow, rather than lead, community transmission. Important learning points for future pandemics are summarized.

Prospective study of loss of health-related quality adjusted life years in children and their families due to uncomplicated and hospitalised varicella.

INTRODUCTION AND AIMS: Although usually benign, varicella can lead to serious complications and sometimes long-term sequelae. Vaccines are safe and effective but not yet included in immunisation programmes in many countries. We aimed to quantify the impact on health-related quality of life (HRQoL) in terms of quality-adjusted life years (QALY) in children with varicella and their families, key to assessing cost-utility in countries with low mortality due to this infection. METHODS: Children with varicella in the community and admitted to hospitals in Portugal were included over 18 months from January 2019. Children's and carers' HRQoL losses were assessed prospectively using standard multi-attribute utility instruments for measuring HRQoL (EQ-5D and CHU9D), from presentation to recovery, allowing the calculation of QALYs. RESULTS: Among 109 families with children with varicella recruited from attendees at a pediatric emergency service (community arm), the mean HRQoL loss/child was 2.0 days (95 % CI 1.9-2.2, n = 101) (mean 5.4 QALYs/1000 children (95 % CI 5.3-6.1) and 1.3 days/primary carer (95 % CI 1.2-1.6, n = 103) (mean 3.6 QALYs /1000 carers (95 % CI 3.4-4.4). Among 114 families with children admitted to hospital because of severe varicella or a complication (hospital arm), the mean HRQoL loss/child was 9.8 days (95 % CI 9.4-10.6, n = 114) (mean 26.8 QALYs /1000 children (95 % CI 25.8-29.0) and 8.5 days/primary carer (95 % CI 7.4-9.6, n = 114) (mean 23.4 QALYs/1000 carers (95 % CI 20.3-26.2). Mean QALY losses/1000 patients were particularly high for bone and joint infections [67.5 (95 % CI 43.9-97.6)]. Estimates for children's QALYs lost using the CHU9D tool were well correlated with those obtained using EQ-5D, but substantially lower. CONCLUSIONS: The impact of varicella on HRQoL is substantial. We report the first measurements of QALYs lost in hospitalised children and in the families of children both in the community and admitted to hospital, providing important information to guide vaccination policy recommendations.

In situ DNA oxidative damage by electrochemically generated hydroxyl free radicals on a boron-doped diamond electrode.

In situ DNA oxidative damage by electrochemically generated hydroxyl free radicals has been directly demonstrated on a boron-doped diamond electrode. The DNA-electrochemical biosensor incorporates immobilized double-stranded DNA (dsDNA) as molecular recognition element on the electrode surface, and measures in situ specific binding processes with dsDNA, as it is a complementary tool for the study of bimolecular interaction mechanisms of compounds binding to DNA and enabling the screening and evaluation of the effect caused to DNA by radicals and health hazardous compounds. Oxidants, particularly reactive oxygen species (ROS), play an important role in dsDNA oxidative damage which is strongly related to mutagenesis, carcinogenesis, autoimmune inflammatory, and neurodegenerative diseases. The hydroxyl radical is considered the main contributing ROS to endogenous oxidation of cellular dsDNA causing double-stranded and single-stranded breaks, free bases, and 8-oxoguanine occurrence. The dsDNA-electrochemical biosensor was used to study the interaction between dsDNA immobilized on a boron-doped diamond electrode surface and in situ electrochemically generate hydroxyl radicals. Non-denaturing agarose gel-electrophoresis of the dsDNA films on the electrode surface after interaction with the electrochemically generated hydroxyl radicals clearly showed the occurrence of in situ dsDNA oxidative damage. The importance of the dsDNA-electrochemical biosensor in the evaluation of the dsDNA-hydroxyl radical interactions is clearly demonstrated.

Microcystin-LR and chemically degraded microcystin-LR electrochemical oxidation.

Microcystins (MCs) are cyclic hepatotoxic heptapeptides produced by certain strains of freshwater cyanobacteria toxic for humans and animals. The electrochemical behaviour of microcystin-LR (MC-LR) at a glassy carbon electrode (GCE) was investigated using cyclic voltammetry (CV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV). The oxidation of MC-LR is a diffusion-controlled irreversible and pH-independent process that occurs with the transfer of only one electron and does not involve the formation of any electroactive oxidation product. Upon incubation in different pH electrolytes, homogeneous degradation of MC-LR in solution was electrochemically detected by the appearance of a new oxidation peak at a lower potential. The electrochemical behaviour of chemically degraded MC-LR is an irreversible, pH-dependent process, and involves the formation of two redox products that undergo reversible oxidation. The formation of degradation products of MC-LR was confirmed by HPLC with UV detection at room temperature. Experiments were also carried out in solutions containing constituent MC-LR amino acids, which enabled the understanding of the MC-LR electron transfer reaction and degradation. An oxidation mechanism for MC-LR is proposed.

In situ evaluation of anticancer drug methotrexate-DNA interaction using a DNA-electrochemical biosensor and AFM characterization.

An in situ evaluation of the dsDNA-methotrexate (MTX) interaction was performed by voltammetry using a DNA-electrochemical biosensor and characterized by atomic force microscopy (AFM) at a highly oriented pyrolytic graphite (HOPG) surface. Electrochemical experiments in incubated solutions showed that the interaction of MTX with dsDNA leads to modifications to the dsDNA structure in a time-dependent manner. The AFM images show reorganization of the DNA self-assembled network on the surface of the HOPG electrode upon binding methotrexate and the formation of a more densely packed and slightly thicker MTX-dsDNA lattice with a large number of aggregates embedded into the network film. The intercalation of MTX between complementary base pairs of dsDNA lead to the increase of purine oxidation peaks due to the unwinding of the dsDNA. The dsDNA-electrochemical biosensor and the purinic homo-polynucleotide single stranded sequences of guanosine and adenosine, poly[G] and poly[A]-electrochemical biosensors, were used to investigate and understand the interaction between MTX and dsDNA.

Mycoplasma pneumoniae-associated mucositis.

A 9-year-old boy presented to the emergency department of a paediatric hospital with non-painful lesions on his lips and inside his mouth, associated with lip swelling. On examination, his oral mucosa and lips showed numerous blisters with yellowish serofibrinous content and lip oedema. An eye examination revealed bilateral conjunctival injection. Genitalia was unaffected and no other skin lesions were found. He was on day 4 of clarithromycin prescribed for atypical pneumonia caused by Mycoplasma pneumoniae The patient was diagnosed with M. pneumoniae-associated mucositis and was started on topical treatment with fusidic acid and betamethasone, with gradual improvement of the oral lesions.

Kawasaki Disease: Predictors of Resistance to Intravenous Immunoglobulin and Cardiac Complications. / Doença de Kawasaki: Preditores de Resistência à Imunoglobulina Intravenosa e Complicações Cardíacas.

BACKGROUND: Kawasaki disease (KD) is the leading cause of acquired cardiac disease in children, in developed countries. OBJECTIVES: To identify predictive factors for resistance to intravenous immunoglobulin (IVIG), calculate the effectiveness of Japanese predictive models and characterize cardiac complications. METHODS: Retrospective analysis of KD cases admitted in a Portuguese paediatric hospital between january 2006 and july 2018. ROC curves were used to determine predictive factors for resistance and the multivariate logistic regression analysis was used to develop the predictive model. A significance level of 5% was used. RESULTS: 48 patients with a median age of 36 months were included. The IVIG resistance was 21%. Echocardiographic anomalies were noted in 46%, with coronary involvement in 25% of the sample population. As predictive variable of resistance, the C-reactive protein (CRP) presented an AUC ROC = 0.789, optimal cut-off value 15.1 mg/dL, sensitivity (Sn) 77.8% and specificity (Sp) 78.9%. The erythrocyte sedimentation rate (ESR) presented an AUC ROC = 0.781, optimal cut-off value 90.5 mm/h, Sn 66.7% and Sp 85.7%. The model with the two variables showed p = 0.042 and AUC ROC = 0.790. Predictive strength of Japanese models were: Kobayashi (Sn 63.6%, Sp 77.3%), Egami (Sn 66.7%, Sp 73.1%), Sano (Sn 28.6%, Sp 94.1%). CONCLUSION: CRP and ESR are independent variables that were related to IVIG resistance, with optimal cut-off points of 15.1 mg/dL and 90.5 mm/h, respectively. About half of the patients had some form of cardiac involvement. The Japanese models appeared to be inadequate in our population. (Arq Bras Cardiol. 2021; 116(3):485-491).

FUNDAMENTO: A doença de Kawasaki (DK) é a principal causa de cardiopatia adquirida em idade pediátrica nos países desenvolvidos. OBJETIVOS: Identificar fatores preditores de resistência à imunoglobulina intravenosa (IGIV), calcular a eficácia dos modelos preditores japoneses e caracterizar as complicações cardíacas. MÉTODOS: Análise retrospectiva dos casos de DK entre janeiro de 2006 e julho de 2018 em um hospital pediátrico português. Foram construídas curvas ROC para encontrar fatores preditores de resistência e utilizada regressão logística multivariada para elaborar o modelo preditor. O nível de significância utilizado foi de 5%. RESULTADOS: Foram incluídos 48 pacientes com mediana de idade de 36 meses. Verificou-se resistência à IGIV em 21%. Ocorreram alterações ecocardiográficas em 46%, com envolvimento coronário em 25%. Como variáveis preditoras de resistência, a proteína C-reativa (PC-R) apresentou uma AUC ROC = 0,789, ponto de corte = 15,1 mg/dL, sensibilidade (S) = 77,8% e especificidade (E) = 78,9%. A velocidade de sedimentação (VS) apresentou uma AUC ROC = 0,781, ponto de corte = 90,5 mm/h, S = 66,7% e E = 85,7%. O modelo com as duas variáveis apresentou valor p = 0,042 e AUC ROC = 0,790. O modelo Kobayashi apresentou S = 63,6% e E = 77,3%; Egami, S = 66,7% e E = 73,1%; e Sano, S = 28,6% e E = 94,1%. CONCLUSÃO: A PC-R e a VS são variáveis independentes que mostraram tendência preditora de resistência à IGIV com pontos de corte ótimos de 15,1 mg/dL e 90,5 mm/h, respectivamente. Cerca de metade dos pacientes teve algum tipo de envolvimento cardíaco. Os modelos japoneses não têm utilidade nessa população. (Arq Bras Cardiol. 2021; 116(3):485-491).

Parechovirus Genotype 3 Outbreak Among Young Infants in Portugal.

INTRODUCTION: Human parechovirus type 3 has been recognized as a cause of pediatric infection, occasionally associated with serious illness, including sepsis and meningitis, particularly among young infants. The aim of this study is to report the first known human parechovirus type 3 outbreak in Portugal. MATERIAL AND METHODS: Descriptive study of an outbreak that occurred between the 8th June to the 12th August 2016. Laboratory diagnosis was made by reverse transcription - polymerase chain reaction in the cerebrospinal fluid and/or in stools. Genotyping was made by reverse transcription - polymerase chain reaction and sequencing in stool samples from infants and family members. RESULTS: Human parechovirus type 3 infection was detected in seven infants, of which six were male. Median age was 23 days (5 - 52). One had seizures, with a magnetic resonance imaging scan showing white matter diffusion restriction. The mean duration of admission was 5.6 days (3 - 11), with favourable outcome in all. In three cases there were symptomatic close family members. Human parechovirus type 3 was identified in the stools of three mothers. DISCUSSION: Even though human parechovirus type 3 infection has been well described in the presented age group, most Portuguese hospitals do not have this laboratory diagnosis. Our results are comparable to those obtained in other countries. Besides detection of the virus in the cerebrospinal fluid, there were no raised local or systemic inflammatory markers. CONCLUSION: This study reports the first known outbreak, in infants, of human parechovirus type 3 in Portugal. Although there is no specific treatment, this diagnosis can avoid unnecessary empirical antibiotic treatment and prolonged admissions.

Introdução: O parechovirus humano tipo 3 tem sido reconhecido como causa de infeção em idade pediátrica, ocasionalmente associado a doença grave, incluindo sépsis e meningite, particularmente em pequenos lactentes. Foi objectivo deste estudo descrever o primeiro surto conhecido de infeção por parechovirus humano tipo 3 em Portugal. Material e Métodos: Estudo descritivo de um surto ocorrido entre 8 de junho a 12 de agosto de 2016. O diagnóstico laboratorial foi realizado por transcriptase reversa - reação em cadeia da polimerase no líquido cefalorraquidiano e/ou nas fezes. A genotipagem foi efetuada no Instituto Nacional de Saúde Doutor Ricardo Jorge, por transcriptase reversa - reação em cadeia da polimerase e sequenciação, em amostras de fezes dos lactentes e seus familiares. Resultados: Foi detetada infeção por parechovirus humano tipo 3 em sete lactentes, seis dos quais do sexo masculino, mediana de idade de 23 dias (5 - 52). Uma lactente apresentou convulsões, com múltiplas lesões da substância branca na ressonância magnética nuclear. A duração média de internamento foi de 5,6 dias (3 - 11), com evolução favorável em todos. Em três casos havia familiares próximos sintomáticos. Em três mães foi identificado parechovirus humano tipo 3 nas fezes. Discussão: Embora a infeção por parechovirus humano tipo 3 esteja bem descrita neste grupo etário, a maior parte dos hospitais portugueses não dispõe deste diagnóstico laboratorial. Os resultados obtidos foram semelhantes aos verificados noutros países. Apesar da deteção do vírus no líquido cefalorraquidiano, destaca-se a ausência de resposta inflamatória local ou sistémica. Conclusão: Este estudo reporta o primeiro surto conhecido de infeção por parechovirus humano tipo 3 ocorrido em Portugal em pequenos lactentes. Apesar de não existir tratamento específico, este diagnóstico poderá evitar poderá evitar antibioterapia e internamentos prolongados.

Caveolin proteins electrochemical oxidation and interaction with cholesterol.

Caveolae consist in lipid raft domains composed of caveolin proteins, cholesterol, glycosphingolipids, and GPI-anchored proteins. Caveolin proteins present three different types, caveolin 1 (CAV-1), caveolin 2 (CAV-2) and caveolin 3 (CAV-3), with a very similar structure and amino acid composition. The native caveolin proteins oxidation mechanism was investigated for the first time, at a glassy carbon electrode, using cyclic, square wave and differential pulse voltammetry. The three native caveolin proteins oxidation mechanism presented only one tyrosine and tryptophan amino acid residues oxidation peak. Denatured caveolin proteins presented also the tyrosine, tryptophan and cysteine amino acid residues oxidation peaks. The reverse cholesterol transport is related to caveolae and caveolin proteins, and CAV-1 is directly connected to cholesterol transport. The influence of cholesterol on the three caveolin proteins electrochemical behaviour was evaluated. In the absence and in the presence of cholesterol, significant differences in the CAV-1 oxidation peak current were observed.