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Vascular Disease and Dissection in Pregnancy
Published in Afshan B. Hameed, Diana S. Wolfe, Cardio-Obstetrics, 2020
Vascular Ehlers-Danlos syndrome (EDS) (type IV) is inherited in an autosomal dominant pattern related to mutations in the COL3A1 gene. Patients with EDS are at high risk of early death due to arterial, intestinal, and uterine rupture. Arterial complications occur in an unpredictable manner, even without arterial dilatation, and surgical repair is challenging due to the friable nature of the vascular tissue. Vascular EDS poses a high risk of obstetric complications, and deaths can occur from arterial dissection or uterine rupture. In a study of 81 pregnancies, 12 women died (14.8%) [19]. A subsequent study of 565 pregnancies reported arterial dissection in 9.2%, uterine rupture in 2.6%, and maternal deaths in 6.5% [20]. Other obstetric complications in women with all types of EDS include separation of the symphysis pubis, severe postpartum hemorrhage, and preterm delivery. Pregnancy is considered contraindicated in women with vascular EDS due to the high risk of mortality, but shared decision making is essential, and women who choose to pursue pregnancy should be followed by a multidisciplinary team at a specialized center [20,21].
Cardiac Subcellular Function During Diabetes
Published in Grant N. Pierce, Robert E. Beamish, Naranjan S. Dhalla, Heart Dysfunction in Diabetes, 2019
Grant N. Pierce, Robert E. Beamish, Naranjan S. Dhalla
Removal of sialic acid residues from the sarcolemmal membrane has been closely associated with an increase in membrane permeability.90,91 It is possible, therefore, that a decrease in sialic acid content in cardiac sarcolemma from diabetic rats may alter permeability characteristics. This would correlate well with the phospholipid observations previously discussed and in vivo evidence of a change in integrity of hearts from diabetic animals.37 A “leaky” plasma membrane may also explain reports of altered cation contents69,70 in myocardium from diabetic animals. Precedents for such a permeability change have been reported during diabetes in other tissues in the body. For example, an increase in vascular tissue permeability has been observed early in the diabetic process.92
Abies Spectabilis (D. Don) G. Don (Syn. A. Webbiana Lindl.) Family: Coniferae
Published in L.D. Kapoor, Handbook of Ayurvedic Medicinal Plants, 2017
Pharmacognostical description — Epidermis of the stem is covered by glandular hairs and rubiaceous-type stomata. The pericycle has lignified fibers arranged in a discontinuous ring. The vascular tissue, having five to six rings of xylem with small strands of phloem, is occupied by pith with two medullary bundles, either separate or fused. The epidermis of the leaves has glandular and covering trichomes and stomata and rosettes of calcium oxalate crystals are present. 21
Spirulina extract improves age-induced vascular dysfunction
Published in Pharmaceutical Biology, 2022
Michal Majewski, Mercedes Klett-Mingo, Carlos M. Verdasco-Martín, Cristina Otero, Mercedes Ferrer
Under pathophysiological conditions associated with increased oxidative stress, different homeostatic mechanisms can be activated. Thus, nuclear factor erythroid 2-related factor 2 (Nrf2) mediates the transcription of phase II antioxidant proteins responsible for the elimination of reactive oxygen species (ROS; Howden 2013) and hemeoxygenase-1 (HO-1). This process has been recognised as one of the most important factors protecting vascular tissue from a pro-oxidant environment (Kang et al. 2015; Drummond et al. 2019). This enzyme synthesises carbon monoxide (CO) from the degradation of haem to biliverdin/bilirubin. This gas mediator molecule is able to activate GC, increase cGMP levels and induce relaxation (Ryter et al. 2006). In addition, both NO (Félétou and Vanhoutte, 1996) and CO (Leffler et al. 2006) are able to activate potassium channels and induce membrane hyperpolarization in vascular smooth muscle cells. Thus, the participation of hyperpolarizing mechanisms through the activation of calcium- and ATP-dependent potassium channels (KCa or KATP, respectively), in conditions with decreased NO bioavailability, has been demonstrated in conductance and resistance vessels (Edwards et al. 2010; Dogan et al. 2019).
Differential expression of flowering genes in Arabidopsis thaliana under chronic and acute ionizing radiation
Published in International Journal of Radiation Biology, 2019
Maryna V. Kryvokhyzha, Konstantin V. Krutovsky, Namik M. Rashydov
To study the effects of irradiation on flowering, we measured the expression of six key flowering-related genes, such as APETALA1 (AP1), CONSTANS (CO), FLOWERING LOCUS C (FLC), FLOWERING LOCUS T (FT), GIGANTEA (GI), and LEAFY (LFY) under irradiation and control condition. The genes CO and GI are regulated by circadian clock and are key genes in the photoperiod flowering time pathway. The FT gene encodes the florigen, a ‘flowering hormone’ or hormone-like protein, responsible for controlling and/or triggering flowering in plants (Smaczniak et al. 2012). The FT gene is expressed also in the vascular tissue of leaves. The FT protein activates the MADS-box genes, important regulators of flower development (Jeong and Clark 2005; Kaufmann et al. 2010).
New Regenerative Vascular Grafts for Hemodialysis Access: Evaluation of a Preclinical Animal Model
Published in Journal of Investigative Surgery, 2018
Karen Tatiana Valencia Rivero, Juliana Jaramillo Escobar, Sergio David Galvis Forero, Maria Clara Miranda Saldaña, Rocío del Pilar López Panqueva, Néstor Fernando Sandoval Reyes, Juan Carlos Briceño Triana
The objective of this study was to design and fabricate SIS vascular grafts for hemodialysis access and to evaluate an animal model for the in vivo evaluation of graft patency and vascular tissue regeneration in the arteriovenous connection. A U-shaped SIS vascular graft was developed and studied in sheep and swine. It was determined that the swine model was better than the sheep model, as the inflammatory reaction it presented was less severe. Once the animal model had been defined, a surgical protocol was established for the implantation of SIS vascular grafts and their comparison with commercial synthetic vascular grafts (PTFE). Based on the results of the U-shaped vascular graft, a second design was developed. A C-shaped SIS vascular graft with a circumferential reinforcement also made of SIS was tested in vivo with the animal model established previously. The results showed a robust and consistent animal model and a vascular graft capable of improving on the performance of current synthetic vascular grafts. This study, therefore, achieved its intended objective and may be helpful with other research involving in vivo studies of vascular grafts for hemodialysis access.