Cell-imaging studies of highly substituted oxazole derivatives as organelle targeting fluorophores (OTFPs).

The field of biomedical science has progressed enormously in the past decade. With the advent of newer diagnostic tools for imaging and detection, identification of root cause of a disease is now remarkably accurate and specific. Small organic fluorophores in these connections are in great demand currently for cellular organelle sensing and detecting, due to their non-invasiveness, excellent accuracy and bio-sensitivity. Small molecule fluorescence probes offer most potent area for biological sensing with diagnostic imaging ability. These organelle targetable fluorescent probes are produced through synthetic manipulations to get the desired, decent fluorescence properties. When a suitable organelle specific functional group is installed within these highly fluorescent scaffolds, then these molecules turn out to be as lysotracker, mitotracker and cytoplasm-stainer in mammalian cells with high efficiencies (high Pearson co-efficient factors). The present work demonstrated an environmentally benign (green) one-pot, sp3 C-H functionalization of highly substituted oxazole derivatives with excellent photophysical properties. These molecules were further modified by installing organelle specific targetable groups (sensors/detectors) which selectively localize in specific intra-cellular organelles.

Prediction of groundwater nitrate concentration in a semiarid region using hybrid Bayesian artificial intelligence approaches.

Nitrate is a major pollutant in groundwater whose main source is municipal wastewater and agricultural activities. In the present study, Bayesian approaches such as Bayesian generalized linear model (BGLM), Bayesian regularized neural network (BRNN), Bayesian additive regression tree (BART), and Bayesian ridge regression (BRR) were used to model groundwater nitrate contamination in a semiarid region Marvdasht watershed, Fars province, Iran. Eleven groundwater (GW) nitrate conditioning factors have been taken as input parameters for predictive modeling. The results showed that the Bayesian models used in this study were all competent to model groundwater nitrate and the BART model with R2 = 0.83 was more efficient than the other models. The result of variable importance showed that potassium (K) has the highest importance in the models followed by rainfall, altitude, groundwater depth, and distance from the residential area. The results of the study can support the decision-making process to control and reduce the sources of nitrate pollution.

Siglecs Modulate Activities of Immune Cells Through Positive and Negative Regulation of ROS Generation.

Reactive oxygen species (ROS) are a group of oxygen-containing highly-reactive molecules produced from oxidative metabolic processes or in response to intracellular signals like cytokines and external stimuli like pathogen attack. They regulate a range of physiological processes and are involved in innate immune responses against infectious agents. Deregulation of ROS contributes to a plethora of disease conditions. Sialic acids are carbohydrates, present on cell surfaces or soluble proteins. Sialic acid-binding immunoglobulin-like lectins (Siglecs) recognize and bind to sialic acids. These are widely expressed on various types of immune cells. Siglecs modulate immune activation and can promote or inhibit ROS generation under different contexts. Siglecs promote ROS-dependent cell death in neutrophils and eosinophils while limiting oxidative stress associated with chronic obstructive pulmonary disease (COPD), sickle cell disease (SCD), coronavirus disease-2019 (COVID-19), etc. This review distinguishes itself in summarizing the current understanding of the role of Siglecs in moderating ROS production and their distinct effect on different immune cells; that ultimately determine the cellular response and the disease outcome. This is an important field of investigation having scope for both expansion and medical importance.

An Unusual Case of a Dematiaceous Fungus with an Exclusive Cerebral Involvement After ABO-Incompatible Renal Transplantation.

BACKGROUND Cladophialophora carrionii was detected postoperatively in a cerebral space-occupying lesion of a patient who had undergone ABO-incompatible renal transplantation. The infection was successfully treated with oral terbinafine and itraconazole. CASE REPORT An otherwise healthy 46-year-old man underwent ABO-incompatible renal transplantation. Postoperatively, he was hemodynamically stable and the graft was functioning well. Within 2 weeks, the patient developed clinical depression, followed by seizures and left-side hemiparesis. There were no skin findings. Radiological investigation showed 2 space-occupying lesions in the brain parenchyma. The patient's condition improved after partial frontal lobectomy and microsurgical abscess evacuation, with a short course of liposomal amphotericin B and a combination of oral terbinafine and itraconazole. Microbiological examination of the pus showed growth of C. carrionii, which predominantly causes subcutaneous mycoses. CONCLUSIONS It is very rare for melanized fungal infections to cause an exclusively cerebral disease without any skin involvement. Furthermore, among established cases, C. carrionii is a very rarely detected pathogen.

Polysubstituted Imidazoles as LysoTracker Molecules: Their Synthesis via Iodine/H2O and Cell-Imaging Studies.

An iodine-catalyzed, environmentally benign one-pot methodology has been developed for the synthesis of diverse substituted imidazoles. This transition-metal-free, aerobic, water-mediated cyclization reaction is operationally simple and works well with different amines or aldehydes by multiple C-N bond formations with satisfactory yield. The methodology is regioselective as well as scalable. These imidazole derivatives show excellent fluorescence properties both in the solid and solution phase, which is further extended to live-cell imaging. Due to the suitable fluorescence properties of these scaffolds, lysosome-directing groups are incorporated in two of these derivatized imidazoles to track intracellular lysosomes. Successfully, those molecules show bright blue fluorescence while detecting lysosomes in human or murine cells and can be considered to be rapid lysosome-staining probes.

Predicting the deforestation probability using the binary logistic regression, random forest, ensemble rotational forest, REPTree: A case study at the Gumani River Basin, India.

Rapid population growth and its corresponding effects like the expansion of human settlement, increasing agricultural land, and industry lead to the loss of forest area in most parts of the world especially in such highly populated nations like India. Forest canopy density (FCD) is a useful measure to assess the forest cover change in its own as numerous works of forest change have been done using only FCD with the help of remote sensing and GIS. The coupling of binary logistic regression (BLR), random forest (RF), ensemble of rotational forest and reduced error pruning trees (RTF-REPTree) with FCD makes it more convenient to find out the deforestation probability. Advanced vegetation index (AVI), bare soil index (BSI), shadow index (SI), and scaled vegetation density (VD) derived from Landsat imageries are the main input parameters to identify the FCD. After preparing the FCDs of 1990, 2000, 2010 and 2017 the deforestation map of the study area was prepared and considered as dependent parameter for deforestation probability modelling. On the other hand, twelve deforestation determining factors were used to delineate the deforestation probability with the help of BLR, RF and RTF-REPTree models. These deforestation probability models were validated through area under curve (AUC), receiver operating characteristics (ROC), efficiency, true skill statistics (TSS) and Kappa co-efficient. The validation result shows that all the models like BLR (AUC = 0.874), RF (AUC = 0.886) and RTF-REPTree (AUC = 0.919) have good capability of assessing the deforestation probability but among them, RTF-REPTree has the highest accuracy level. The result also shows that low canopy density area i.e. not under the dense forest cover has increased by 9.26% from 1990 to 2017. Besides, nearly 30% of the forested land is under high to very high deforestation probable zone, which needs to be protected with immediate measures.

Sialic Acid-Siglec-E Interactions During Pseudomonas aeruginosa Infection of Macrophages Interferes With Phagosome Maturation by Altering Intracellular Calcium Concentrations.

Pseudomonas aeruginosa (PA) is commonly associated with nosocomial and chronic infections of lungs. We have earlier demonstrated that an acidic sugar, sialic acid, is present in PA which is recognized and bound by sialic acid binding immunoglobulin type lectins (siglecs) expressed on neutrophils. Here, we have tried to gain a detailed insight into the immunosuppressive role of sialic acid-siglec interactions in macrophage-mediated clearance of sialylated PA (PA+Sia). We have demonstrated that PA+Sia shows enhanced binding (~1.5-fold) to macrophages due to additional interactions between sialic acids and siglec-E and exhibited more phagocytosis. However, internalization of PA+Sia is associated with a reduction in respiratory burst and increase in anti-inflammatory cytokines secretion which is reversed upon desialylation of the bacteria. Phagocytosis of PA+Sia is also associated with reduced intracellular calcium ion concentrations and altered calcium-dependent signaling which negatively affects phagosome maturation. Consequently, although more PA+Sia was localized in early phagosomes (Rab5 compartment), only fewer bacteria reach into the late phagosomal compartment (Rab7). Possibly, this leads to reduced phagosome lysosome fusion where reduced numbers of PA+Sia are trafficked into lysosomes, compared to PA-Sia. Thus, internalized PA+Sia remain viable and replicates intracellularly in macrophages. We have also demonstrated that such siglec-E-sialic acid interaction recruited SHP-1/SHP-2 phosphatases which modulate MAPK and NF-κB signaling pathways. Disrupting sialic acid-siglec-E interaction by silencing siglec-E in macrophages results in improved bactericidal response against PA+Sia characterized by robust respiratory burst, enhanced intracellular calcium levels and nuclear translocation of p65 component of NF-κB complex leading to increased pro-inflammatory cytokine secretion. Taken together, we have identified that sialic acid-siglec-E interactions is another pathway utilized by PA in order to suppress macrophage antimicrobial responses and inhibit phagosome maturation, thereby persisting as an intracellular pathogen in macrophages.

Successful Third Kidney Transplant After Desensitization for Combined Human Leucocyte Antigen (HLA) and ABO Incompatibility: A Case Report and Review of Literature.

BACKGROUND In the present era, kidney transplantation across immunological barriers (ABO incompatibility and human leucocyte antigen (HLA) incompatibility) is a successful strategy to provide transplantation to immunologically high-risk patients. The safety and outcome of crossing both ABO and HLA barriers simultaneously in a retransplantation scenario is rarely reported from the developing world. CASE REPORT A 30-year-old female underwent a third living donor kidney transplantation. Her previous 2 transplants being lost to chronic allograft nephropathy. The transplantation was done across a simultaneous blood group as well as HLA incompatibility. The donor was the mother who was blood group B, with the recipient being blood group O. The complement dependent cytotoxicity crossmatch of the pair was negative but the flow cross match for T as well as B lymphocytes was positive. The mean fluorescence intensity value for class I antigens was 6951 and that for class 2 antigens was 7534. The patient underwent a desensitization procedure including rituximab, plasmapheresis and intravenous immunoglobulin pre-transplantation. The pre-transplantation isohemaglutunin titer was <1: 8 and the donor specific antibody against class 1 antigens was <2200 and <770 against class 2 antigens. Induction was done with anti-thymocyte globulin in the dose of 3 mg/kg in 2 divided doses. The patient is maintained on triple immunosuppression with tacrolimus, prednisolone and mycophenolate mofetil. After a follow-up period of 5 months, she maintains a good graft function with serum creatinine of 1.01 mg/dL. CONCLUSIONS With the advances in the desensitizing procedures in the developing world, kidney transplantation across a combined HLA and ABO incompatible barrier can be offered to these highly sensitized patients, even in case of retransplantation.

Detection of Lysosome by a Fluorescent Heterocycle: Development of Fused Pyrido-Imidazo-Indole Framework via Cu-Catalyzed Tandem N-Arylation.

Fluorescent active small molecules for organelle-specific bioimaging are in great demand. We synthesized 20 different pyrido-imidazo-indole fused heterocycles (6-5-5-6 ring) via copper catalyzed tandem N-arylation reaction in moderate to good yields. Due to decent fluorescent property, lysosome-directing moieties were attached on two of these heterocycles. Delightfully, those molecules tracked lysosome with bright blue fluorescence and colocalized with a known lysosome marker (Lysotracker Red) in human/murine cells. Therefore, it may be considered as a rapid (10 min) lysosome staining probe.

Monitoring Coil-Globule Transitions of Thermoresponsive Polymers by Using NMR Solvent Relaxation.

Thermoresponsive polymers exhibit coil-globule transition in aqueous solution where the polymer undergoes transition from the coil-like morphology to a globular form with the change of temperature. Such transitions also reflect changes in the solvent dynamics captured by various spectroscopic methods. In this work, we construct a phenomenological model to capture the dynamics of the NMR relaxation of water molecules of an aqueous solution of thermoresponsive polymers that are known to form hydrogen bonds with the solvent water molecules. The model relies on the behavior of the polymer-solvent hydrogen bonds and the sharing of rotational kinetic energy of water molecules in the vicinity of the polymer chain and the bulk. This is shown to provide a direct estimate of the fractional change of the polymer-water hydrogen bonds across lower critical solution temperature from NMR relaxation data of solvent water along with a reliable estimate of the transition temperature. In addition, it also provides a measure of the dispersion of the strengths of these hydrogen bonds. We exemplify the validity of this model by successfully fitting the experimental data to show that the extracted parameters provide significant insights into the role played by the hydrogen bonds in the process. The possible extension of this model to solvents that form no hydrogen bonds with the polymers is also discussed.