The study described here was undertaken to extend the observation that some transcription factors can either stimulate or suppress gene expression depending on the local environment of their DNA binding site. It is suggested that if such transcription factors also had a mechanism to sense the expression level of the gene they control, then they could create a feedback loop able to keep expression of a gene within a limited range. The transcription factor would be activating if gene expression were determined to be too low and repressing if it were too high. To test the above idea, I have examined the effect of gene expression on the ability of the transcription factor binding areas, the promoter/enhancers, to stimulate or attenuate gene expression depending on the existing expression level of a gene.  https://www.selleckchem.com/products/l-arginine-l-glutamate.html  Studies were carried out with a population of 61 human genes expressed selectively in liver. A similar study was carried out with thyroid genes. The total length of all promoter/enhancers in each gene sequence was determined and compared in weakly and strongly expressed genes. The results showed that the level of expression was stimulated by promoter/enhancers in weakly expressed genes and antagonized in strongly expressed ones. The results are interpreted to indicate that promoter/enhancers act to keep expression of a gene within a defined range that is appropriate for the gene's function.
  To evaluate the splenic uptake function after irradiation with high-energy X-rays.
 
  Fourteen male Wistar rats were distributed into three groups. Group 1 (n = 6) - control, non-irradiated; Group 2 (n = 4) - animals that were irradiated and studied 24 h after irradiation; and Group 3 (n = 4) - animals that were irradiated and studied 48 h after irradiation. The animals were irradiated with 8 Gy X-rays in the abdominal region. According with the groups, after 24 or 48 h, 1 ml/kg of a 50% colloidal carbon solution was injected in the left internal jugular vein. After 40 min, the spleens were removed for histological studies. Macrophages containing carbon pigments in their cytoplasms were counted in 16 consecutive microscopic fields, and their means were considered as the uptake pattern of each animal.
 
  In the control groups, carbon pigments were captured by macrophages in the red and white pulps, while in the irradiated groups, the uptake in the marginal zone, around the white pulp, was enhanced. There was no disorder on the splenic parenchyma or necrosis in histological analyzes. Qualitatively rare apoptotic events were observed, with no difference between control and irradiated animals.
 
  The high-energy X-ray, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles. This radiation was not associated with morphological changes, nor with necrosis or apoptosis of splenic tissue.
 The high-energy X-ray, used in radiotherapy, modifies the splenic clearance, enhancing the amount of marginal zone macrophages containing colloid particles. This radiation was not associated with morphological changes, nor with necrosis or apoptosis of splenic tissue.Alzheimer's disease (AD), a neurodegenerative disorder affects more than 35 million people globally. Acetylcholinesterase suppression is the common approach to enhance the well-being of AD patients by increasing the duration of acetylcholine in the cholinergic synapses. Generally, herbal secondary metabolites are reported to be a major resource for acetylcholinesterase inhibitors (AChEIs). Trans-tephrostachin was reported from Tephrosia purpurea for AChE inhibition. Here, we report on the design, synthesis, and assessment of human acetylcholinesterase inhibitory activity from trans-tephrostachin derivatives or analogs as anti-AD agents. The five newly synthesized compounds 4a. 4b, 4c, 4d and 4e displayed potent inhibitory activities with IC50 values of 35.0, 35.6, 10.6, 10.3, and 28.1 μM respectively. AChE enzyme kinetic study was performed for the five derived compounds using the Ellman's method. The Lineweaver-Burk and the secondary plots revealed the mixed inhibition for 4a, 4c and 4d whereas 4b and 4e demonstrated competitive inhibition. Molecular docking and molecular dynamics simulations showed the derivatives or analogs of trans-tephrostachin attained a high binding affinity and efficacy than the standard drug. In conclusion, trans-tephrostachin and its derivative compounds could become effective agents for further drug development to treat AD.Synthetic hydroxyapatite (HA) due to its high biocompatibility, anti-inflammatory properties, high stability, and a flexible structure in combination with magnetic nanoparticles has the strong potential to be used in modern medicine including tissue engineering, imaging, and drug delivery. Herein, a hydrothermal process was used to prepare magnetite nanoparticles dispersed on the hydroxyapatite nanorods with cetyltrimethylammonium bromide (CTAB) as a surfactant. Characterization study of the synthesized iron oxide-hydroxyapatite (IO-HA) nanocomposite was performed by FT-IR spectroscopy, X-ray powder diffraction, energy dispersive X-Ray analysis (EDX) for elemental mapping, transmission electron microscopy, and vibrating sample magnetometer. Then, the biocompatibility of the synthesized nanocomposite studied by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay and hemocompatibility assay. Focus on this point, curcumin loaded IO-HA (Cur@IO-HA) was developed for exploring the pH-sensitivity of the drug carrier and then evaluating its cellular uptake. The in vitro efficacy of the synthesized nanocomposites as a magnetic resonance imaging (MRI) contrast agent was also investigated. Our results showed that IO-HA nanocomposite is non-cytotoxic and hemocompatible as well as a good pH-sensitive drug carrier and a favorable MRI T2 contrast agent. Comparing to the free curcumin, Cur@IO-HA displayed a good cellular uptake. Taking into account the above issues, IO-HA nanocomposite has the most potential for application as a theranostic MRI contrast agent.Soil salinity is a global problem that has adverse effects on both agriculture and aquaculture production. The main objectives of this study were to observe the distribution pattern of soil salinity in the accreted and non-accreted land of the Noakhali district and to determine the intensity of salinity at different depths (1-2 cm, 15-20 cm, and 45-60 cm). Soil samples from 60 sampling sites were analyzed to measure electrical conductivity (EC). The two-way factorial ANOVA model revealed a significant effect of depth (p less then 0.001) and sampling locations (p less then 0.001) on soil salinity. After decomposition of this model, one-way ANOVA showed that 45-60 cm of depth contains significantly higher soil salinity (p less then 0.01) ranging from 0.28 to 4.70 dS/m compared to 1-2 cm (ranging from 0.14 to 2.39 dS/m) and 15-20 cm (ranging from 0.18 to 2.37 dS/m) depth. In the case of accreted lands, surface (1-2 cm) and mid-layer (15-20 cm) soils were found slight to severely saline, while soil at a depth of 45-60 cm was found high to extremely saline.