Vascular Endothelial Dysfunction in β-Thalassemia Occurs Despite Increased eNOS Expression and Preserved Vascular Smooth Muscle Cell Reactivity to NO

The hereditary β-thalassemia major condition requires regular lifelong blood transfusions. Transfusion-related iron overloading has been associated with the onset of cardiovascular complications, including cardiac dysfunction and vascular anomalies. By using an untransfused murine model of β-thalassemia major, we tested the hypothesis that vascular endothelial dysfunction, alterations of arterial structure and of its mechanical properties would occur despite the absence of treatments.Vascular function and structure were evaluated ex vivo. Compared to the controls, endothelium-dependent vasodilation with acetylcholine was blunted in mesenteric resistance arteries of β-thalassemic mice while the endothelium-independent vasodilator (sodium nitroprusside) produced comparable vessel dilation, indicating endothelial cell impairment with preserved smooth muscle cell reactivity to nitric oxide (NO). While these findings suggest a decrease in NO bioavailability, Western blotting showed heightened expression of aortic endothelial NO synthase (eNOS) in β-thalassemia. Vascular remodeling of the common carotid arteries revealed increased medial elastin content. Under isobaric conditions, the carotid arteries of β-thalassemic mice exhibited decreased wall stress and softening due to structural changes of the vessel wall.A complex vasculopathy was identified in untransfused β-thalassemic mice characterized by altered carotid artery structure and endothelial dysfunction of resistance arterioles, likely attributable to reduced NO bioavailability despite enhanced vascular eNOS expression

Polar extracts from (Tunisian) Acacia salicina Lindl. Study of the antimicrobial and antigenotoxic activities

<p>Abstract</p> <p>Background</p> <p>Methanolic, aqueous and Total Oligomer Flavonoids (TOF)-enriched extracts obtained from the leaves of <it>Acacia salicina </it>'Lindl.' were investigated for antibacterial, antimutagenic and antioxidant activities.</p> <p>Methods</p> <p>The antimicrobial activity was tested on the Gram positive and Gram negative reference bacterial strains. The Mutagenic and antimutagenic activities against direct acting mutagens, methylmethane sulfonate (MMS) and 4-nitro-o-phenylenediamine (NOPD), and indirect acting mutagens, 2-aminoanthracene (2-AA) and benzo[a]pyrene (B(a)P) were performed with <it>S. typhimurium </it>TA102 and TA98 assay systems. In addition, the enzymatic and nonenzymatic methods were employed to evaluate the anti-oxidative effects of the tested extracts.</p> <p>Results</p> <p>A significant effect against the Gram positive and Gram negative reference bacterial strains was observed with all the extracts. The mutagenic and antimutagenic studies revealed that all the extracts decreased the mutagenicity induced by B(a)P (7.5 μg/plate), 2-AA (5 μg/plate), MMS (1.3 mg/plate) and NOPD (10 μg/plate). Likewise, all the extracts showed an important free radical scavenging activity towards the superoxide anion generated by the xanthine/xanthine oxidase assay system, as well as high Trolox Equivalent Antioxidant Capacity (TEAC), against the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS)⁺• radical. TOF-enriched extract exhibited the highest protective effect against free radicals, direct acting-mutagen and metabolically activated S9-dependent mutagens.</p> <p>Conclusions</p> <p>The present study indicates that the extracts from <it>A. salicina </it>leaves are a significant source of compounds with the antimutagenic and antioxidant activities, and this may be useful for developing potential chemopreventive substances.</p

Definition and significance of polycystic ovarian morphology: a task force report from the Androgen Excess and Polycystic Ovary Syndrome Society

First published online: December 16, 2013BACKGROUND The diagnosis of polycystic ovary syndrome (PCOS) relies on clinical, biological and morphological criteria. With the advent of ultrasonography, follicle excess has become the main aspect of polycystic ovarian morphology (PCOM). Since 2003, most investigators have used a threshold of 12 follicles (measuring 2–9 mm in diameter) per whole ovary, but that now seems obsolete. An increase in ovarian volume (OV) and/or area may also be considered accurate markers of PCOM, yet their utility compared with follicle excess remains unclear. METHODS Published peer-reviewed medical literature about PCOM was searched using PubMed.gov online facilities and was submitted to critical assessment by a panel of experts. Studies reporting antral follicle counts (AFC) or follicle number per ovary (FNPO) using transvaginal ultrasonography in healthy women of reproductive age were also included. Only studies that reported the mean or median AFC or FNPO of follicles measuring 2–9 mm, 2–10 mm or <10 mm in diameter, or visualized all follicles, were included. RESULTS Studies addressing women recruited from the general population and studies comparing control and PCOS populations with appropriate statistics were convergent towards setting the threshold for increased FNPO at ≥25 follicles, in women aged 18–35 years. These studies suggested maintaining the threshold for increased OV at ≥10 ml. Critical analysis of the literature showed that OV had less diagnostic potential for PCOM compared with FNPO. The review did not identify any additional diagnostic advantage for other ultrasound metrics such as specific measurements of ovarian stroma or blood flow. Even though serum concentrations of anti-Müllerian hormone (AMH) showed a diagnostic performance for PCOM that was equal to or better than that of FNPO in some series, the accuracy and reproducibility issues of currently available AMH assays preclude the establishment of a threshold value for its use as a surrogate marker of PCOM. PCOM does not associate with significant consequences for health in the absence of other symptoms of PCOS but, because of the use of inconsistent definitions of PCOM among studies, this question cannot be answered with absolute certainty. CONCLUSIONS The Task Force recommends using FNPO for the definition of PCOM setting the threshold at ≥25, but only when using newer technology that affords maximal resolution of ovarian follicles (i.e. transducer frequency ≥8 MHz). If such technology is not available, we recommend using OV rather than FNPO for the diagnosis of PCOM for routine daily practice but not for research studies that require the precise full characterization of patients. The Task Force recognizes the still unmet need for standardization of the follicle counting technique and the need for regularly updating the thresholds used to define follicle excess, particularly in diverse populations. Serum AMH concentration generated great expectations as a surrogate marker for the follicle excess of PCOM, but full standardization of AMH assays is needed before they can be routinely used for clinical practice and research. Finally, the finding of PCOM in ovulatory women not showing clinical or biochemical androgen excess may be inconsequential, even though some studies suggest that isolated PCOM may represent the milder end of the PCOS spectrum.Didier Dewailly, Marla E. Lujan, Enrico Carmina, Marcelle I. Cedars, Joop Laven, Robert J. Norman, and Héctor F. Escobar-Morreal