MyoD, Myogenin, and Desmin-nls-lacZ Transgene Emphasize the Distinct Patterns of Satellite Cell Activation in Growth and Regeneration

Although satellite cell differentiation is involved in postnatal myogenesis from growth to posttrauma regeneration, the early stages of this process remain unclear. This study investigatedpHuDes-nls-lacZtransgene activity, as revealed by X-gal staining and the accumulation of MyoD, myogenin, endogenous desmin, and myosin, in order to determine whether satellite cells share the same activation program during growth and regeneration. After birth, skeletal myonuclei in which myogenin expression was limited were briefly characterized by transgene activity. Satellite cells were only evidenced by MyoD and slow myosin accumulation, but failed to initiate transgene expression. After freeze trauma, satellite cell activation led to MyoD, myogenin, and desmin expression. Subsequently, when myosin expression occurred, transgene activation was apparent in regenerating structures, with more intense X-gal staining in mononucleated cells than regenerating myotubes. After the second week posttrauma, only desmin and myogenin expression were maintained in regenerating structures. In culture, the behavior of satellite cells showed that desmin expression was committed before transgene activation occurred, i.e., concurrently with MyoD, myogenin, myosin expression, and the first fusion events. Quantitative analysis confirmed the discrepancy between endogenous desmin and transgene expression and demonstrated the close correlation between transgene activation and the fusion index. Our results strongly suggest that satellite cells promote distinct pathways of myogenic response during growth and regeneration.     

Trace elements status in multinodular goiter

Importance of iodine and selenium in thyroid metabolism is well known, but the roles of other essential trace elements including copper, zinc, manganese and iron on thyroid hormone homeostasis remain unclear. The aim of this study was to investigate the status of those trace elements in benign thyroid diseases and evaluate possible links between trace element concentrations and thyroid hormones.The study group was composed of 25 patients with multinodular goiter. Concentrations of thyroid hormones (plasma-free thyroxine, FT₄; free triiodothyronine, FT₃; and thyrotropin, TSH), selenium, copper, zinc, manganese and iron in plasma, and urinary iodine were determined. The results were compared with those of a healthy control group (n=20) with no thyroid disorder.A mild iodine deficiency was observed in the patients with multinodular goiter whereas urinary iodine levels were in the range of “normal” values in healthy controls. All patients were euthyroid, and their thyroid hormone concentrations were not significantly different from the control group. Plasma selenium, zinc and iron concentrations did not differ from controls, while copper and manganese levels were found to be significantly higher in the patients with multinodular goiter indicating links between these trace elements and thyroid function and possibly in development of goiter. Besides iodine, there was a significant correlation between plasma copper concentration and FT₃/FT₄ ratio.     

Detailed Characterization of Brain Dysfunction in a Long-Term Rodent Model of Critical Illness

Neurochemical Research - Critical illness encompasses a wide spectrum of life-threatening clinical conditions requiring intensive care. Our objective was to evaluate cognitive, inflammatory and...     

Effects of Ethanolic Extract of Cynara cardunculus (Artichoke) Leaves on Neuroinflammatory and Neurochemical Parameters in a Diet-Induced Mice Obesity Model

Neurochemical Research - This study aimed to evaluate the effect of Cynara cardunculus leaf ethanol extract on inflammatory and oxidative stress parameters in the hypothalamus, prefrontal cortex,...     

Bacteriophages of lactic acid bacteria and their impact on milk fermentations

Every biotechnology process that relies on the use of bacteria to make a product or to overproduce a molecule may, at some time, struggle with the presence of virulent phages. For example, phages are the primary cause of fermentation failure in the milk transformation industry. This review focuses on the recent scientific advances in the field of lactic acid bacteria phage research. Three specific topics, namely, the sources of contamination, the detection methods and the control procedures will be discussed.     

Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer

The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.     

Synthesis of modified proanthocyanidins: easy and general introduction of a hydroxy group at C-6 of catechin; efficient synthesis of elephantorrhizol

A general procedure for the oxidation of catechin derivatives is described, leading to the introduction of a new hydroxy group at C-6. This procedure has been applied for the synthesis of elephantorrhizol, a natural flavan-3-ol exhibiting a fully substituted cycle A.