ABSTRACT BACKGROUND: Coronavirus disease 2019 (COVID-19) is an ongoing global health threat. However, currently, no standard therapy has been approved for the disease. OBJECTIVES: To evaluate the clinical effectiveness of convalescent plasma (CP) in patients with acute respiratory distress syndrome (ARDS) due to COVID-19. DESIGN AND SETTING: Retrospective study conducted at Kayseri City Education and Research Hospital, Kayseri, Turkey. METHODS: The case group consisted of adult patients (> 18 years) with ARDS due to COVID-19 who received CP in combination with antiviral and supportive treatment. These patients were compared with others who only received antiviral and supportive treatment. RESULTS: During the study period, a total of 30 patients with ARDS due to COVID-19 were included. Eleven patients (36%) received CP in combination with antiviral and supportive treatment, whereas nineteen patients (64%) in the control group only received antiviral and supportive treatment. On admission, the median age, demographic and clinical data and initial laboratory test results were similar between the groups (P > 0.05). On the 14th day of treatment, the laboratory values remained similar between the groups (P > 0.05). The mortality rates were not significantly different between the groups. CONCLUSION: CP treatment did not affect mortality or lead to clinical improvement for COVID-19 patients with ARDS.

As propriedades eletroquímicas da olmesartana (OLME) foram investigadas por voltametria cíclia (CV) e voltametria de pulso diferencial (DPV) em eletrodo de gota pendente de mercúrio (HMDE). Todos os estudos foram baseados no sinal de redução eletroquímica de OLME irreversível e controlada pela adsorção em aproximadamente -1,2 e -1,5 V vs. Ag/AgCl em pH 5,0 e tampão Britton-Robinson (BR). Esse caráter adsortivo da molécula foi usado para se desenvolver um método de voltametria adsortiva de redissolução catódica de pulso diferencial (DPCAdSV) novo, completamente validado, rápido, seletivo e simples na determinação direta de OLME em dosagem farmacêutica e urina humana, sem etapas demoradas anteriores ao ensaio. A corrente de pico da redução eletroquímica de OLME varia linearmente com a concentração, na faixa de 4,7 × 10-8 mol L-1 (0,0262 µg mL-1 ) a 8,3 × 10-6 mol L-1 (4,636 µg mL-1). Neste método, o limite de quantificação (LOQ) foi determinado como sendo 5,1 × 10-7 mol L-1 (0,284 µg mL-1). O método foi aplicado na determinação do conteúdo de OLME em preparações farmacêuticas comerciais e em urina humana adulterada, e mostrou ser altamente exato e preciso, com um desvio padrão relativo de menos de 10% em todas as aplicações.

The electrochemical properties of olmesartan (OLME) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at hanging mercury drop electrode (HMDE). All studies were based on the irreversible and adsorption-controlled electrochemical reduction signal of OLME at about -1.2 and -1.5 V vs. Ag/AgCl at pH 5.0 in Britton-Robinson (BR) buffer. This adsorptive character of the molecule was used to develop a novel, fully validated, rapid, selective and simple differential pulse cathodic adsorptive stripping voltammeric (DPCAdSV) method for the direct determination of OLME in pharmaceutical dosage form and human urine without time-consuming steps prior to drug assay. Peak current of electrochemical reduction of OLME was found to vary linearly with the concentration in the range from 4.7 × 10-8 mol L-1 (0.0262 µg mL-1) to 8.3 × 10-6 mol L-1 (4.636 µg mL-1). In this method, limit of quantification (LOQ) was found to be 5.1 × 10-7 mol L-1 (0.284 µg mL-1). The method was applied to determine the content of OLME in commercial pharmaceutical preparation and spiked human urine. It was found to be highly accurate and precise, having a relative standard deviation of less than 10% for all applications.

O comportamento eletroquímico do aliscireno (ALS) foi estudado por meio de métodos experimentais eletroquímicos e cálculos teóricos realizados em nível B3LYP/6-31+G (d)//AM1. Estudos eletroquímicos foram baseados nos processos de redução reversível controlada por adsorção a ca. -1,5 V em eletrodo gotejante de mercúrio (HMDE) e de oxidação eletroquímica irreversível a ca. 1,0 V em eletrodo de carbono vítreo (GCE) do ALS vs. Ag/AgCl, KCl (3,0 mol L-1) em solução tampão Britton-Robinson pH 10 e 8, respectivamente. De acordo com os achados computacionais e experimentais, o ALS é esperado ser irreversivelmente oxidado na posição benzílica e reversivelmente reduzido nos grupos carbonila da amida. Métodos voltamétricos com e sem modo de redissolução adsortiva foram desenvolvidos e validados para quantificação do ALS em diferentes amostras. Limites de detecção e de quantificação para o ALS foram 6,3 × 10-8 e 2,1 × 10-7 mol L-1 por voltametria de pulso diferencial em HMDE e 1,2 × 10-8 e 3,9 × 10-8 mol L-1 por voltametria de onda quadrada com redissolução catódica adsortiva. Os métodos foram aplicados com sucesso em ensaios de fármacos em comprimidos e em sangue humano com boas recuperações, entre 91,7 e 102,3%, e desvio padrão relativo menor que 10%.

Electrochemical behavior of aliskiren (ALS) was studied via experimental electrochemical methods and theoretical calculations performed at B3LYP/6-31+G (d)//AM1. Cyclic voltammetry studies were carried out based on the adsorption-controlled reversible reduction at ca. -1.5 V on hanging mercury drop electrode (HMDE) and irreversible electrochemical oxidation of ALS at ca. 1.0 V on glassy carbon electrode (GCE), vs. Ag/AgCl, KCl (3.0 mol L-1), in Britton-Robinson buffer at pH 10 and 8, respectively. According to computational and experimental findings, ALS is expected to be oxidized irreversibly at benzylic position and reduced reversibly at amide carbonyl groups. Voltammetric methods with and without adsorptive stripping mode were developed and validated for quantification of ALS in different samples. Limits of detection and of quantification for ALS were 6.3 × 10-8 and 2.1 × 10-7 mol L-1 for differential pulse voltammetry on HMDE and 1.2 × 10-8 and 3.9 × 10-8 mol L-1 for square-wave cathodic adsorptive stripping voltammetry. The methods were successfully applied to assay the drug in tablets and human serum with good recoveries, between 91.7 and 102.3%, having relative standard deviation less than 10%.

Um eletrodo enzimático amperométrico baseado em polímero foi preparado para detecção amperométrica de colesterol livre. Inicialmente, o filme polimérico poli(o-fenilenodiamina) (PoPD) foi eletropolimerizado no meio acetonitrila-água contendo o monômero o-fenilenodiamina (oPD) e ácido canforsulfônico em eletrodo de Pt através da técnica de voltametria cíclica. A enzima oxidase colesterol foi imobilizada sobre a superfície do eletrodo Pt/PoPD. A determinação de colesterol foi realizada por maio do monitoramento da corrente de oxidação de H2O2 produzido enzimaticamente a +0,7 V vs. Ag/AgCl. A concentração da solução tampão, o valor de pH e a temperatura de trabalho otimizados foram 0,05 mol L-1, 7,5 and 40 ºC, respectivamente. O intervalo de trabalho do eletrodo de enzima para colesterol foi 9,8 × 10-3-11 µmol L-1 e tempo de resposta 150 s. Os efeitos de possíveis interferências presentes em amostras de soro em resposta ao eletrodo de enzima foram examinados. A determinação do colesterol total em amostras de soro foi realizada usando o eletrodo de enzima Pt/PoPD/ChOx proposto e os resultados foram em bom acordo com os obtidos pelo método espectrofotométrico.

A polymer-based amperometric enzyme electrode (Pt/PoPD/ChOx) was prepared for the amperometric detection of free cholesterol. Firstly, poly(o-phenylenediamine) (PoPD) polymer film was prepared in acetonitrile-water medium containing o-phenylenediamine (oPD) monomer and (±)-10-camphorsulfonic acid (HCSA) on Pt electrode by the use of cyclic voltammetry technique. Cholesterol oxidase (ChOx) enzyme was immobilized onto Pt/PoPD electrode surface. The determination of cholesterol was performed via monitoring of the oxidation current of enzymatically produced H2O2 at +0.7 V vs. Ag/AgCl. Optimum buffer concentration, pH and working temperature were found as 0.05 mol L-1, 7.5 and 40 ºC, respectively. The working range of enzyme electrode to cholesterol was 9.8 × 10-3-11 µmol L-1 and response time 150 s. The effects of possible interferences present in serum samples on response of enzyme electrode were examined. The determination of total cholesterol in serum samples was performed by using proposed Pt/PoPD/ChOx enzyme electrode and results were in good agreement with those obtained by spectrophotometric method.