Application of -based test systems for the assessment of genotoxic effects of environmental radioactivity of undisturbed mountain soils (Aragats Massif, Armenia).

Plant test systems are a sensitive way to detect the genetic effects of various contaminants in environmental compartments: water, soil and sediments. Biotesting of the genotoxicity of soil samples with various activity concentrations of naturally occurring (Ra, Th, K) and artificial (Cs) radionuclides in soil, from the territory of the Aragats Massif (Armenia) was carried out with the application of the micronucleus (Trad-MСN) and stamen hair mutation (Trad-SHM) bioassays of (clone 02) model test-object in the soil - plant system. Undisturbed soil sampling was performed in the southern slopes of the Aragats Massif, from different altitudes (from 1000 to 3200 m above sea level).

Assessing radon hazard in drinking water: A comprehensive approach integrating deterministic and probabilistic methods with water consumption routines.

The research aimed to determine the spatiotemporal distribution patterns of radon activity concentrations in tap water of Yerevan city and assess radon-associated hazards using both deterministic and probabilistic approaches. This was accomplished by integrating one-year monitoring data of radon in water with water consumption habits among adult population clusters, which were identified through food frequency questionnaire in Yerevan. The study findings indicated variations in radon activity levels across administrative districts.

Human intestinal stromal cells promote homeostasis in normal mucosa but inflammation in Crohn's disease in a retinoic acid-deficient manner.

Intestinal stromal cells (SCs), which synthesize the extracellular matrix that gives the mucosa its structure, are newly appreciated to play a role in mucosal inflammation. Here, we show that human intestinal vimentinCD90smooth muscle actin SCs synthesize retinoic acid (RA) at levels equivalent to intestinal epithelial cells, a function in the human intestine previously attributed exclusively to epithelial cells. Crohn's disease SCs (Crohn's SCs), however, synthesized markedly less RA than SCs from healthy intestine (normal SCs).

Epidermal retinol dehydrogenases cyclically regulate stem cell markers and clock genes and influence hair composition.

The hair follicle (HF) is a self-renewing adult miniorgan that undergoes drastic metabolic and morphological changes during precisely timed cyclic organogenesis. The HF cycle is known to be regulated by steroid hormones, growth factors and circadian clock genes. Recent data also suggest a role for a vitamin A derivative, all-trans-retinoic acid (ATRA), the activating ligand of transcription factors, retinoic acid receptors, in the regulation of the HF cycle.