Depletion of Intracellular Glutamine Pools Triggers Toxoplasma gondii Stage Conversion in Human Glutamatergic Neurons

Toxoplasma gondii chronically infects the brain as latent cysts containing bradyzoites and causes various effects in the host. Recently, the molecular mechanisms of cyst formation in the mouse brain have been elucidated, but those in the human brain remain largely unknown. Here, we show that abnormal glutamine metabolism caused by both interferon-γ (IFN-γ) stimulation and T. gondii infection induce cyst formation in human neuroblastoma cells regardless of the anti-T. gondii host factor nitric oxide (NO) level or Indoleamine 2,3-dioxygenase-1 (IDO1) expression. IFN-γ stimulation promoted intracellular glutamine degradation in human neuronal cells. Additionally, T. gondii infection inhibited the mRNA expression of the host glutamine transporters SLC38A1 and SLC38A2. These dual effects led to glutamine starvation and triggered T. gondii stage conversion in human neuronal cells. Furthermore, these mechanisms are conserved in human iPSC-derived glutamatergic neurons. Taken together, our data suggest that glutamine starvation in host cells is an important trigger of T. gondii stage conversion in human neurons.

TPTPC and BHC integrated grid connected energy storage system for power loss reduction

Purpose This paper aims to propose a bidirectional hidden converter (BHC)-based three-phase DC–AC conversion for energy storage application. BHC is the new concept to vary an energy storage device voltage into wide range. Hidden converter power loss and power rating are reduced by using zero-sequence injection-based carrier-based pulse-width modulation (CBPWM) strategy. Design/methodology/approach By using this control strategy, a BHC processes only little amount of power during double-stage conversion, mostly during direct or single-stage conversion of the three-phase three-port converter (TPTPC) only processing the maximum power. Findings TPTPC consists of two sets of positive group switches for inversion process, one set of switches is regular inverter switches called vertical positive group switches, and the second set is anti-series switches, which are horizontally connected for direct or single-stage conversion. Originality/value Characteristics, principles and implementations of proposed DC–AC 3Ø conversion system and its PWM strategy are analyzed. Through experimental outputs, the effectiveness and viability of the proposed solutions are validated.

Fabrication of High Flux Polysulfone/Mesoporous Silica Nanocomposite Ultrafiltration Membranes for Industrial Wastewater Treatment

The inclusion of nanosphere particles like mesoporous silica MSNS~500(nm) inside the membrane substance matrix substantially enhanced water permeability and dye rejection. The dry/wet stage conversion method was employed for fabricating all membranes. The influence of different concentrations for MSNS (0–8% wt.%) in the existence of povidone (PVP) acting in the role of pore-forming on the behavior of the PSF-UF membrane was investigated. Results revealed that as soon as MSNS level grew up till 6 wt. percent, the rejection of Methylene blue (MB) dye gradually increased. The morphological properties of UF-produced membranes PS/PVP/SiO2 were investigated using scanning electron microscopy. They demonstrated a considerable degree of MB rejection of 84.7 percent, as well as an increase in MSNS concentration to 6 wt. percent. Besides, as the MSNS concentration raised to 6 wt.%, the membrane's permeability dropped from 429.2 L/m2.h for PS/PVP to 136 L/m2.h for PS/PVP/SiO2 (6%) membrane. Only water was permitted to pass across the hydrophilic UF fabricated membrane on the feed side, improving the quality of the water stream on permeate portion, making the fabricated membranes appropriate for industrial treatment of wastewater. The addendum of the polyvinylpyrrolidone acting as an additive to the investigated membranes enhanced their efficiency.

Facile Synthesis of Sulfonyl Chlorides/Bromides from Sulfonyl Hydrazides

A simple and rapid method for efficient synthesis of sulfonyl chlorides/bromides from sulfonyl hydrazide with NXS (X = Cl or Br) and late-stage conversion to several other functional groups was described. A variety of nucleophiles could be engaged in this transformation, thus permitting the synthesis of complex sulfonamides and sulfonates. In most cases, these reactions are highly selective, simple, and clean, affording products at excellent yields.

Facile Synthesis of Sulfonyl Chlorides/Bromides from Sulfonyl Hydrazides

A simple and rapid method for efficient synthesis of sulfonyl chlorides/bromides from sulfonyl hydrazide with NXS (X = Cl or Br) and late-stage conversion to several other functional groups has been described. A variety of nucleophiles could be engaged in this transformation thus permitting the synthesis of complex sulfonamides, sulfonates. In most cases, these reactions are highly selective, simple, and clean, affording products in excellent yields.

Encystation of Entamoeba histolytica in Axenic Culture

Entamoeba histolytica is a parasitic protozoan that causes amoebic dysentery, which affects approximately 90 million people each year worldwide. E. histolytica is transmitted through ingestion of food and water contaminated with the cyst form, which undergoes excystation in the small intestine to the trophozoite form that colonizes the large intestine. The reptile pathogen Entamoeba invadens has served as a model for studying stage conversion between the trophozoite and cyst form due to lack of reproducible encystation of E. histolytica in the laboratory. Although much has been learned about encystation and excystation using E. invadens, the findings do not fully translate to E. histolytica due to the extensive genetic and host differences between these species. Here, we present the first reproducible encystation of E. histolytica in vitro. The cysts produced were viable and displayed the four characteristic hallmarks: round shape, chitinous cell wall, tetranucleation, and detergent resistance. Using flow cytometry analysis, glucose limitation and high cell density were key for encystation, as for E. invadens. Entry into encystation was enhanced by the short-chain fatty acids acetate and propionate, unlike for E. invadens. This new model will now allow the further study of E. histolytica stage conversion, transmission, and treatment.

From Genes to Transcripts, a Tightly Regulated Journey in Plasmodium

Over the past decade, we have witnessed significant progresses in understanding gene regulation in Apicomplexa including the human malaria parasite, Plasmodium falciparum. This parasite possesses the ability to convert in multiple stages in various hosts, cell types, and environments. Recent findings indicate that P. falciparum is talented at using efficient and complementary molecular mechanisms to ensure a tight control of gene expression at each stage of its life cycle. Here, we review the current understanding on the contribution of the epigenome, atypical transcription factors, and chromatin organization to regulate stage conversion in P. falciparum. The adjustment of these regulatory mechanisms occurring during the progression of the life cycle will be extensively discussed.