[Persistent Polyclonal B-Cell Lymphocytosis (PPBL): An Entity That Is Not What it Seems]. / Linfocitose Policlonal Persistente de Células B (LPPB): Uma Entidade que Não É o que Parece.

Persistent polyclonal B-cell lymphocytosis is a rare disease with chronic lymphocytosis of polyclonal origin, which is more frequent in mostly asymptomatic middle-aged female smokers. The hallmark of this entity is the presence of bilobed/binucleated B lymphocytes, which are polyclonal as demonstrated by immunophenotyping; an elevated IgM level is common. This disease shows, in most cases, an indolent course over many years and, although controversial, it may rarely convert to malignant lymphoma. In addition to smoking, a genetic predisposition for persistent polyclonal B-cell lymphocytosis is likely. Recurrent genetic aberrations have been described. The differential diagnosis includes non-Hodgkin's lymphoma and a clear distinction between both entities is of the utmost importance because treatment is generally not indicated in the former: instead, regular follow-up is recommended. The authors describe the case of a 46-year-old female smoker, who presented with chronic lymphocytosis, elevated IgM and circulating binucleated lymphocytes. Excluding lymphoma was important considering the unusual presentation with constitutional symptoms and splenomegaly.

A linfocitose policlonal persistente de células B é uma doença rara, caracterizada por linfocitose crónica policlonal, que ocorre mais frequentemente em mulheres fumadoras de meia-idade, que se apresentam assintomáticas ou com sintomas inespecíficos. A presença de linfócitos B binucleados é considerada a assinatura citomorfológica desta entidade. A imunofenotipagem comprova a sua origem policlonal, observando-se muitas vezes uma elevação da IgM sérica. É controverso se existe um risco aumentado de desenvolvimento de linfoma. A predisposição genética é também um fator de risco, além do tabagismo. Apesar da sua natureza policlonal, alterações genéticas recorrentes estão descritas. Na linfocitose policlonal persistente de células B a abordagem terapêutica consiste habitualmente numa vigilância regular, o que reforça a importância do seu reconhecimento. Os autores descrevem o caso de uma mulher de 46 anos, fumadora, com linfocitose crónica, IgM elevada e linfócitos binucleados. O diagnóstico diferencial com linfoma assumiu particular importância, considerando os sintomas constitucionais e esplenomegalia que apresentava.

Simultaneous voltammetric determination of 7-methyl-guanine and 5-methyl-cytosine using a cathodically pre-treated boron-doped diamond electrode.

Given the importance of identifying the presence of biomarkers of human diseases in DNA samples, the main objective of this work was to investigate, for the first time, the electro-catalytic oxidation of 7-methyl-guanine (7-mGua) and 5-methyl-cytosine (5-mCyt) on a boron doped diamond electrode pre-treated cathodically (red-BDDE), using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The anodic peak potentials of 7-mGua and 5-mCyt by DPV were at E = 1.04 V and E = 1.37 V at pH = 4.5, indicating excellent peak separation of approximately 330 mV between species. Using DPV, experimental conditions such as supporting electrolyte, pH and influence of interferents were also investigated to develop a sensitive and selective method for individual and simultaneous quantification of these biomarkers. The analytical curves for the simultaneous quantification of 7-mGua and 5-mCyt in the acid medium (pH = 4.5) were: concentration range of 0.50-5.00 µmol L-1 (r = 0.999), detection limit of 0.27 µmol L-1 for 7-mGua; from 3.00 to 25.00 µmol L-1 (r = 0.998), with a detection limit of 1.69 µmol L-1 for 5-mCyt. A new DP voltammetric method for the simultaneous detection and quantification of biomarkers 7-mGua and 5-mCyt using a red-BDDE is proposed.

In situ voltammetric analysis of 2,4-dichlorophenoxyacetic acid in environmental water using a boron doped diamond electrode and an adapted unmanned air vehicle sampling platform.

In the present work a voltammetric method was developed for in situ detection of 2,4-dichlorophenoxyacetic acid (2,4-D) in environmental water samples, using a compact and lightweight electrochemical cell using a fused deposition modeling (FDM) 3D printer with biodegradable polylactic acid filament, and a boron-doped diamond electrode (BDDE). The samples were collected by an adapted unmanned aerial vehicle (UAV) with a micropump and a miniature solenoid valve powered by an open source microcontroller. After optimizing the supporting electrolyte, pH and parameters of the square wave voltammetry (SWV) a linear analytical curve for 2,4-D in 0.5 mol L-1 Na2SO4 (pH = 2.0 regulated using 0.5 mol L-1 H2SO4 solution) in a concentration range from 100 nmol L-1 to 911 nmol L-1 with 34 nmol L-1 as the limit of detection was obtained. The same samples in situ analyzed by SWV were sent to the laboratory for gas chromatography-mass spectrometry (GC-MS) analysis; and there was no statistical difference from the concentration of 2,4-D in any of the samples at a 95% confidence level. Therefore, the method developed for quantification of 2,4-D in water provides an important environmental monitoring tool since it enables access to difficult areas in a fast, practical and safe way. This is the first time that an adapted UAV with these features has been used to collect environmental water for in situ electrochemical analysis as a screening tool to alert the presence of environmental hazard compounds, such as 2,4-D. Thus, this method can be used by environmental and sanitary control agencies to monitor or to supervise environmental water quality with response in real time.

Anodic behavior of clioquinol at a glassy carbon electrode.

Clioquinol is an antifungal, antiprotozoal and an Alzheimer's disease drug with cytotoxic activity toward human cancer cells. The electrochemical behavior of clioquinol and its oxidation product was studied using cyclic, differential pulse and square-wave voltammetry over a wide pH range on a glassy carbon electrode. The results revealed that the oxidation of clioquinol is an irreversible pH-dependent process that proceeds with the transfer of one electron and one proton in an adsorption-controlled mechanism and results in the formation of a main oxidation product, which adsorbs very strongly on the glassy carbon surface. The charge transfer coefficient was calculated as 0.64. The adsorbed oxidation product presented reversible redox behavior, with two electron and two proton transfer. The electrochemical oxidation of clioquinol as a phenolic compound involves the formation of a phenoxy radical which reacts in at least two ways: in one pathway the radical initiates polymerization, the products remaining at the electrode surface, and in the other the radical is oxidized to a quinone-like structure. A mechanism for the oxidation of clioquinol is proposed.