Determination of picloram in waters by sequential injection chromatography with UV detection

This paper describes a sequential injection chromatography procedure for determination of picloram in waters exploring the low backpressure of a 2.5 cm long monolithic C18 column. Separation of the analyte from the matrix was achieved in less than 60 s using a mobile phase composed by 20:80 (v v-1) acetonitrile:5.0 mmol L-1 H3PO4 and flow rate of 30 μL s-1. Detection was made at 223 nm with a 40 mm optical path length cell. The limits of detection and quantification were 33 and 137 μg L-1, respectively. The proposed method is sensitive enough to monitor the maximum concentration level for picloram in drinking water (500 μg L-1). The sampling frequency is 60 analyses per hour, consuming only 300 μL of acetonitrile per analysis. The proposed methodology was applied to spiked river water samples and no statistically significant differences were observed in comparison to a conventional HPLC-UV method.Este trabalho descreve um procedimento de cromatografia por injeção seqüencial para a determinação de picloram em águas explorando a baixa pressão de uma coluna monolítica C18 de 2,5 cm de comprimento. A separação do analito da matriz foi obtida em menos de 60 s usando como fase móvel uma mistura de acetonitrila e H3PO4 5,0 mmol L-1 na proporção 20:80 (v v-1) e vazão de 30 μL s-1. Detecção foi feita a 223 nm com uma cela de 40 mm de caminho óptico. O limite de detecção do método é adequado para monitorar o nível de concentração máximo permitido para picloram em água potável (500 μg L-1). A frequência de amostragem é de 60 análises por hora, consumindo 300 μL de acetonitrila por análise. A metodologia foi aplicada a águas de rio fortificadas, não sendo observadas diferenças estatisticamente significativas em comparação com a metodologia convencional de HPLC-UV.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sequential Injection Analysis with Square Wave Voltammetry (SI-SWV) Detection for Investigation of Adsorption of Picloram on a Clay Soil

This paper describes a sequential injection analysis method, with detection by square wave voltammetry using a hanging mercury drop electrode, to determine the herbicide picloram in soil extract

Antiproliferative activity of synthetic fatty acid amides from renewable resources

AbstractIn the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line—the most aggressive CNS cancer

Ehrlich ascites tumor-bearing mice treated with aqueous ethanol plant extract from Euphorbia tirucalli showed signs of systemic toxicity

Purpose: To evaluate the antitumor effect of a latex extract from Euphorbia tirucalli Linn. (Euphorbiaceae) and its toxicity.Methods: Aqueous ethanol and petroleum ether extracts were obtained through maceration. .Maximum tolerated dose was determined in healthy mice. Antitumor activity was measured in Ehrlich ascites tumor-bearing mice treated with the extract through intraperitoneal injection (62.5, 125 or 250 mg/kg) every 48 h (four doses). Efficacy was assessed by weight gain, abdominal circumference, volume of ascitic fluid and packed tumor cells, tumor cell viability and survival. Toxicity indicators were serum glucose, triglycerides, total proteins, activity of alanine and aspartate aminotransferases and mass of heart, spleen, kidney and liver. A hemolysis assay was also performed.Results: Doses of 62.5 and 125 mg/kg caused no antitumor activity, while 250 mg/kg dose reduced weight gain (3-fold), abdominal circumference and volume of ascitic fluid (> 50 %) and packed cells (50 %), but lowered tumor cell viability (40 %). However, mice treated with the extract survived for a shorter time than control mice. Furthermore, the 250 mg/kg dose caused cardiac atrophy, splenomegaly and fasting hyperglycemia. The extract caused hemolysis, and the half-maximal effective concentration (EC50) was 1.6 (0.9 – 2.7) mg/mL.Conclusion: Euphorbia tirucalli extract inhibits Ehrlich ascites tumor in mice, but the therapeutic dose is also harmful to non-tumor tissues.Keywords: Euphorbia tirucalli, Ehrlich ascites tumor-bearing mice, Antitumor, Toxicity, Cardiac atrophy, Splenomegal

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p

SARS-CoV-2 uses CD4 to infect T helper lymphocytes

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent of a major global outbreak of respiratory tract disease known as Coronavirus Disease 2019 (COVID-19). SARS-CoV-2 infects mainly lungs and may cause several immune-related complications, such as lymphocytopenia and cytokine storm, which are associated with the severity of the disease and predict mortality. The mechanism by which SARS-CoV-2 infection may result in immune system dysfunction is still not fully understood. Here, we show that SARS-CoV-2 infects human CD4+ T helper cells, but not CD8+ T cells, and is present in blood and bronchoalveolar lavage T helper cells of severe COVID-19 patients. We demonstrated that SARS-CoV-2 spike glycoprotein (S) directly binds to the CD4 molecule, which in turn mediates the entry of SARS-CoV-2 in T helper cells. This leads to impaired CD4 T cell function and may cause cell death. SARS-CoV-2-infected T helper cells express higher levels of IL-10, which is associated with viral persistence and disease severity. Thus, CD4-mediated SARS-CoV-2 infection of T helper cells may contribute to a poor immune response in COVID-19 patients.</p