Mast cell activation markers for in vitro study

ABSTRACT

Mast cells (MCs) are well known for their role in allergic conditions. This cell can be activated by various types of secretagogues, ranging from a small chemical to a huge protein. Mast cell activation by secretagogues triggers the increase in intracellular calcium (iCa²⁺) concentration, granule trafficking, and exocytosis. Activated mast cells release their intra-granular pre-stored mediator or the newly synthesized mediator in the exocytosis process, in the form of degranulation or secretion. There are at least three types of exocytosis in mast cells, which are suggested to contribute to the release of different mediators, i.e.,, piecemeal, kiss-and-run, and compound exocytosis. The status of mast cells, i.e., activated or resting, is often determined by measuring the concentration of the released mediator such as histamine or β-hexosaminidase. This review summarizes several mast cell components that have been and are generally used as mast cell activation indicator, from the classical histamine and β-hexosaminidase measurement, to eicosanoid and granule trafficking observation. Basic principle of the component determination is also explained with their specified research application and purpose. The information will help to predict the experiment results with a certain study design.     

Evidence for a ''new'' Rh gene complex producing the rare Cx (Rh9) antigen in the Somali population of East Africa

Four unrelated propositi with an unusual Cx-positive Rh phenotype were found during a population survey of 513 Somalis. The Rh phenotypes of the propositi and their available relatives showed that the gene that produces the Cx antigen differs from that found in whites in that it is inherited with an Rh gene complex that produces no C or D. Instead, this gene complex produced es, c, and probably V, although it appeared that no f (ce) antigen was made. These findings suggest that Cx cannot be considered a simple variant form of C but rather a distinct rare Rh antigen that may occur in association with different Rh gene complexes.     

Evaluation of the Persistence and Leaching Behaviour of Thiram Fungicide in Soil,Water and Oil Palm Leaves

The residual levels and persistence of thiram in the soil, water and oil palm seedling leaves were investigated under field conditions. The experimental plots were carried out on a clay loam soil and applied with three treatments namely; manufacturer’s recommended dosage (25.6 g a.i. plot^?1), manufacturer’s double recommended dosage (51.2 g a.i. plot^?1), and control (water) were applied. Thiram residues were detected in the soil from day 0 to day 3 in the range of 0.22–27.04 mg kg^?1. Low concentrations of thiram were observed in the water and leave samples in the range of 0.27–2.52 mg L^?1 and 1.34–12.28 mg kg^?1, respectively. Results have shown that thiram has a rapid degradation and has less persistence due to climatic factors. These findings suggest that thiram is safe when applied at manufacturer’s recommended dosage on oil palm seedlings due to low residual levels observed in soil and water bodies.     

Electrochemical detection of Cd(ii) ions in complex matrices with nanopipets

Heavy metal contamination and its detrimental health effects are a growing concern globally. Several metal mitigation systems and regulatory approaches have been implemented to minimize the negative impacts on human health. However, none of these function at maximum efficiency, mainly due to the lack of accurate information about metal speciation. Therefore, there is a critical need to develop novel, cheap, efficient, and robust metal detecting sensors. In this study, we describe the application of a nanopipet based electrochemical sensor to detect aqueous Cd(ii) ions. The inner radius of our nanopipets is ∼300 nm, and the fundamental mechanism behind our sensor''s response is ion transfer between two immiscible electrolyte solutions (ITIES). The absence of redox behavior makes ITIES an excellent, attractive electrochemical tool to study various ions in aqueous solutions. In this study, we used 1,10-phenanthroline as our ionophore in the organic phase (dichloroethane) to facilitate the transfer of Cd(ii) ions from the polar aqueous phase to the less polar organic phase. Unlike previous studies, we characterized our nanopipet in complicated matrices, including, but not limited to, tris buffer and artificial seawater. We performed quantitative assessments to determine our sensor''s limit of detection, stability, sensitivity, and selectivity. We further show that our nanosensor can detect free Cd(ii) ions in the presence of strong complexing agents such as ethylenediaminetetraacetic acid, 2,3-dimercaptosuccinic acid, etc. We quantified the concentration of free Cd(ii) ions in a water sample collected from a local lagoon. Thus, we showcased the power of our nanopipets to act as a robust, accurate, and efficient speciation sensor to detect Cd(ii) ions in environmental samples.

A nanopipet electrochemical sensor was successfully utilized to detect free Cd(ll) ions in complicated matrices and real environmental water samples.