Letrozole vs estradiol valerate induced PCOS in rats: glycemic, oxidative and inflammatory status assessment.

The objective of our study was to investigate glycemic, oxidative/antioxidative and inflammatory status in letrozole and estradiol valerate induced polycystic ovarian syndrome (PCOS) models. Sixty adult female Wistar rats were divided into four groups: L (0.2 mg letrozole/0.5 ml carboxymethyl cellulose (CMC), daily for 30 days), the control group CL, EV (one i.m. injection of 5 mg EV/0.5 ml sesame oil) and its corresponding control group CEV. After 30 days, ovarian morphology was assessed through ultrasound, serum free testosterone was determined, and an oral glucose tolerance test was performed. Blood, muscle, liver and periovarian adipose tissue (POAT) were collected for oxidative/antioxidative and inflammatory status evaluation. Free testosterone was increased only in the L group, while fasting glycemia was higher in the EV group. Both L and EV led to a significantly decreased level of muscle malondialehyde (MDA) and liver glutathione peroxidase (GPx) activity, while in POAT, MDA level diminished and GPx activity increased. The only difference between the two protocols was in muscle, where after L administration, GPx activity was significantly lower. Implementation of both protocols resulted in an increased expression of pNFKB in muscle, liver and POAT. The expression of monocyte chemoattractant protein 1 (MCP1) increased in liver and POAT after L administration, while in the EV group, MCP1 and STAT3 decreased in POAT. Our study shows that both protocols are characterized by an inflammatory environment in the usually insulin resistant tissues of human PCOS, without generating oxidative stress. In addition, EV has mild metabolic effects and unexpected interference with MCP1 expression in POAT, which require further investigation.

Cytotoxicity assessment of graphene-based nanomaterials on human dental follicle stem cells.

Graphene-oxide (GO) and its most encountered derivatives, thermally reduced graphene oxide (TRGO) and nitrogen-doped graphene (N-Gr), were synthesized and structurally characterized by spectroscopic techniques, like Raman and (13)C MAS solid state NMR. Several biological effects (cytotoxicity, oxidative stress induction, and cellular and mithocondrial membrane alterations) induced by such graphene-based materials on human dental follicle stem cells were investigated. Graphene oxide shows the lowest cytotoxic effect, followed by the nitrogen-doped graphene, while thermally reduced graphene oxide exhibits high cytotoxic effects. Graphene oxide induces oxidative stress without causing cell membrane damage. Nitrogen-doped graphene shows a slight antioxidant activity; however, at high doses (20 and 40 µg/ml) it causes membrane damage. Both graphene oxide and nitrogen-doped graphene seem to be valuable candidates for usage in dental nanocomposites.

Usefulness of real-time elastography strain ratio in the assessment of bile duct ligation-induced liver injury and the hepatoprotective effect of chitosan: an experimental animal study.

The purpose of the study described here was to evaluate the usefulness of the elastographic strain ratio in the assessment of liver changes in an experimental animal setting and the hepatoprotective effects of chitosan. Ultrasonography and Strain Ratio calculation were performed before and after bile duct ligation (BDL) in three groups of Wistar albino rats (n = 10 animals per group): (i) rats subjected to bile duct ligation only; (ii) rats subjected to bile duct ligation and administered chitosan for 14 d; (iii) rats subjected to bile duct ligation and administered chitosan for 7 d. The results were compared with the laboratory data and pathologic findings. Strain ratios revealed an increase in liver stiffness after bile duct ligation (p < 0.05), except in the group with chitosan administered for 7 d, and agreed with laboratory and pathology data. In conclusion, strain ratio can be used as an experimental research instrument in the assessment of liver response to injury. To the best of our knowledge, this is the first study reporting on the usefulness of the sonoelastographic liver-to-kidney strain ratio in assessing the effects of experimentally induced liver lesions.