Para investigar se estresse oxidativo contribui para a progressão da calcificação/estenose valvar aórtica (VA), avaliamos a produção de espécies reativas de oxigênio (ERO) e efeitos dos antioxidantes tempol e ác. lipóico em modelo de calcificação VA em coelhos. Superóxido, H2O2 e 3-nitrotirosina aumentaram em células inflamatórias e principalmente nos núcleos de calcificação, juntamente com as subunidades p22phox, Nox2 da NADPH oxidase e da proteína dissulfeto isomerase, que co-localizam. PCR mostrou aumento da Nox4 em relação a Nox1. A calcificação foi menor com ác.lipóico e maior com tempol, coicidindo com resultados de modelo in vitro em células musculares lisas. VA humanas estenóticas tiveram aumento semelhante de ERO e da expressão protéica em torno da calcificação. Estresse oxidativo pode contribuir para a progressão da estenose aórtica. / To invetigate whether oxidative stress contributes to aortic valve (AV) calcification/stenosis progression, we assessed reactive oxygen species (ROS) production and effects of antioxidants tempol and lipoic acid in a rabbit AV calcification model. Superoxide, H2O2 and 3-nitrotyrosine increased in inflammatory cells and mainly in calcifying nuclei, coincident with NADPH oxidase subunits p22phox, Nox2 and protein disulfide isomerase, which co-localized. PCR showed switch from Nox1 to Nox4. Calcification was smaller with lipoic acid and greater with tempol, similar to an in vitro smooth muscle cell calcification model results. Human stenotic AV had analogous increase in ROS and protein expression around calcifying nuclei. Oxidative stress can contribute to AV stenosis progression.

Osteopontin, also called cytokine Eta-1, is a multifunctional protein containing Arg-Gly-Asp-Ser (RODS) cell-binding sequence. It interacts with αvβ1, αvβ3 and αvβ5 integrins and CD44 receptors. OPN is suggested to play a role during inflammation via the recruitment and retention of macrophages and T-cells to inflamed sites. OPN regulates the production of inflammatory cytokines and nitric oxide in macrophages. In this review, we will discuss diverse roles of OPN related to cardiovascular diseases, including atherosclerosis, valvular stenosis, hypertrophy, myocardial infarction and heart failure.

Reef-building corals are subject to high amounts of stress, including pollution and rising sea surface temperatures due to climate change. These factors can affect the ability of corals to produce their calcium carbonate skeletons. Evaluation of the effects of climate change may be facilitated by evaluation of records of coral skeletal growth over a long period of time. The aim of this study was to evaluate skeletal growth of the coral Orbicella faveolata in La Parguera, Puerto Rico over a 32-year period. For this, 14 Orbicella faveolata core samples were collected from corals at two reefs (1.2 km apart) in southwestern Puerto Rico. Coral cores were used to obtain skeletal growth data. Average skeletal extension, density, and calcification was determined for subannual and annual periods, and compared between sites. Time series and growth master chronologies were constructed and compared between corals at the two reef sites. In addition, sea surface temperature (SST) data was obtained and summarized into time series, and correlated with coral growth chronologies for the 32-year period. Results showed that two Orbicella faveolata, growth parameters (extension and calcification) were similar between Turrumote and Pinnacles reefs, while density was non-significantly greater on Pinnacles Reef between 1973 and 2004. SST had a weak, and non-significant correlation to growth parameters over time.

Thesis (Ph.D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2010. / Cataloged from PDF version of thesis. / Includes bibliographical references. / The mechanisms involved in the formation of coral skeletons are examined using a laboratory model for coral calcification and the growth of living corals under different environmental conditions. Abiogenic aragonite was precipitated from seawater over a range of saturation states (Chapter 1). Abiogenic aragonite formed at high saturation state ([Omega]>~20) had a granular appearance and was enriched in trace elements, similar to the crystals found within the centers of calcification and dark bands in coral skeletons. Abiogenic aragonite formed fibrous crystals at lower saturation states, similar to the crystals which radiate out from the centers of calcification. These similarities suggest that the internal calcifying environment of the coral experiences a wide range of saturation states. To estimate when periods of high or low saturation state occur within the coral, corals were stained to mark the skeleton deposited during specific time intervals (Chapter 2). Dark bands are shown to form between dusk and dawn. A conceptual model is proposed in which daytime saturation state is limited by the availability of CO₂ due to the uptake of CO₂ by photosynthesis. To test the potential for photosynthesis to limit CO₂ availability to calcification, corals were grown under experimentally manipulated CO₂ and nutrient levels. Elevated CO₂ levels were found to decrease calcification in zooxanthellate colonies of the coral Astrangia poculata, however the addition of inorganic nutrients reduced the negative impact of CO₂ (Chapter 3), while reduced calcification rates were associated with elevated nutrients at ambient CO₂ levels. Together these results suggest that nutrient availability may limit photosynthesis under elevated pCO₂ conditions, while at ambient conditions additional stimulation of photosynthesis may limit the CO₂ supply to calcification. To further test the interaction of photosynthesis with calcification, the effects of nutrients, CO₂, and temperature were tested on both zooxanthellate and azooxanthellate coral colonies (Chapter 4). No clear pattern of nutrient enhancement of photosynthesis or calcification was found. However, a pronounced gender difference was found in the effect of CO₂ on calcification in spawning corals, with female corals being more sensitive to elevated CO₂. / (cont.) Coral calcification is examined using a laboratory model and living corals. In the laboratory model, abiogenic aragonite formed at high saturation state ([Omega]>~20) had a granular appearance and was enriched in trace elements, similar to centers of calcification and dark bands in corals. Abiogenic aragonite formed fibrous crystals at lower saturation states, similar to crystals which radiate out from centers of calcification. These similarities suggest the calcifying environment of the coral experiences a range of saturation states. To estimate when high or low saturation states occur within the coral, living corals were stained, staining patterns suggest dark bands form between dusk and dawn. A model is proposed in which daytime saturation state is limited by the availability of CO₂. To test the potential for photosynthesis to limit CO₂ availability to calcification, corals were grown under altered CO₂ and nutrient levels. Elevated CO₂ levels decreased calcification in zooxanthellate corals, however addition of nutrients reduced the negative impact of CO₂. This suggests nutrient availability may limit photosynthesis under elevated pCO₂2 conditions. The effects of nutrients, CO₂, and temperature were further tested on both zooxanthellate and azooxanthellate coral colonies. Unexpectedly, a gender difference was found in the effect of CO₂ on calcification. / by Michael Holcomb. / Ph.D.

Alpacas kept in Central Europe are often deficient in vitamin D3, which is supplemented orally or by injection by the owners or veterinarians. Vitamin D3 can be specified in two different units (IU and µg), which differ by a factor of 40. By mixing up these units, an overdosage can be induced. In this study, three alpaca crias were examined after vitamin D3 intoxication, with particular reference to kidney function. All three animals developed non-specific clinical alterations 1–2 weeks after a vitamin D3 overdose of approximately 40 times. Plasma of the animals revealed several alterations. The main findings were severe azotemia, hypercalcemia and hyperphosphatemia, 15 days after treatment. Kidney function analysis (endogenous creatinine clearance) in two of the crias revealed severe glomerular damage. All crias died despite intensive treatment within 23 days after vitamin D3 treatment. Necropsy revealed calcification in different organs, mainly the kidneys, lungs and liver. Since nine other crias in the same group were treated with comparable doses of vitamin D3 and no clinical signs were observed in these animals, it is concluded that individual animals show different levels of sensitivity to vitamin D3.

Background Caseous mitral annular calcification (CMAC) is a rare liquefactive variant of mitral annular calcification (MAC) and superficially mimics a cardiac vegetation or abscess. CMAC is viewed as a benign condition of MAC, while MAC has clinical implications for patients’ lives. Correctly diagnosing CMAC is essential in order to avoid unnecessary interventions, cardiac surgery or even psychological suffering for the patient. Case presentation We report on 6 patients with suspected intra-cardiac masses of the mitral annulus that were referred to our institution for further clarification. A definitive diagnosis of CMAC was achieved by combining echocardiography (Echo), cardiac magnetic resonance imaging (MRI) and cardiac computed tomography (CT) for these patients. Echo assessed the mass itself and possible interactions with the mitral valve. MRI was useful in differentiating the tissue from other benign or malign neoplasms. CT revealed the typical structure of CMAC with a “soft” liquefied centre and an outer capsule with calcification. Conclusion CMAC is a rare condition, and most clinicians and even radiologists are not familiar with it. CMAC can be mistaken for an intra-cardiac tumour, thombus, vegetation, or abscess. Non-invasive multimodality imaging (i.e. Echo, MRI, and CT) helps to establish a definitive diagnosis of CMAC and avoid unnecessary interventions especially in uncertain cases.

Thesis (M.Tech.: Radiography)-Dept. of Radiography, Durban University of Technology, 2008. xxi, 146 leaves, Appendices A-S / The main aim of this study, was to assess the prevalence of coronary artery calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years.

Cardiovascular disease (CVD) and erectile dysfunction (ED) have common etiologies, such as increased adiposity and chronic diseases. Incident ED is known to be a sentinel of CVD, providing a unique opportunity for early lifestyle interventions to attenuate the progression of disease. The internal pudendal artery (IPA) plays an important role in controlling resistance to penile blood flow and thereby erections. Although morphological and functional disturbances in the IPA have been associated with ED, few studies have characterized changes in the IPA as it relates to increased adiposity and chronic diseases (e.g., chronic kidney disease [CKD]). Finally, although both vascular calcification and ED have been shown to be prevalent in patients with CKD, there has yet to be an assessment of associated mechanisms. The effect of lifestyle modifications on erectile function was evaluated in both experimental and clinical settings. Specifically, the studies assessed the effect of caloric restriction (CR) in rats and of chronic exercise in sedentary, overweight or obese male and female subjects. In rats, structural and functional changes of the IPA and erectile responses were characterized in relation to increasing adiposity and to CKD. Experimentally, the susceptibility of various vascular beds to calcification in CKD was determined. Clinically, erectile and female sexual function was assessed in patients with Stage 3 to 5 CKD, who had no history of CVD. In rats, CR blunted the accumulation of abdominal adiposity, and attenuated progression of both endothelial dysfunction and ED, independently of morphological changes in the IPA. Rats with CKD had an increased frequency of ED, greater endothelial dysfunction, and altered vascular morphology, yet vascular calcification per se did not account for ED. In the clinical study, sedentary and overweight or obese males with ED, but not females, had a significantly higher body mass index (BMI) and waist circumference. Chronic exercise significantly improved ED and female sexual dysfunction (FSD). Clinically, CKD was associated with ED and FSD as well as increased coronary artery calcification and endothelial dysfunction. These findings support the concept that early detection of cardiovascular abnormalities, using incident ED as a sentinel, should facilitate early interventions in otherwise asymptomatic populations. / Thesis (Ph.D, Pharmacology & Toxicology) -- Queen's University, 2013-09-30 22:33:20.436

Osmoregulation is an essential process to maintain water and ionic balance and when euryhaline fish move between freshwater and seawater environments as part of their life cycle this presents additional osmoregulatory challenges. Migrating fish can be exposed in both environments to pollutants such as endocrine disrupting chemicals (EDCs) that include natural hormones (e.g. 17β-estradiol; E2), synthetic hormones (e.g. 17α-ethinylestradiol; EE2), and industrial chemicals (e.g. nonylphenol). The focus of this thesis was to study the effects of different categories of EDCs on the osmoregulatory functions of euryhaline fish such as three-spined sticklebacks (Gasterosteus aculeatus) and rainbow trout (Oncorhynchus mykiss). Osmoregulatory variables (such as osmolality, water and ionic content) were compared in plasma and tissues (white muscle and carcass) of rainbow trout. This validated the use of specific tissue parameters as a surrogate of plasma responses to various osmoregulatory challenges. Waterborne exposure to 17α-ethinylestradiol revealed differential sensitivity of vitellogenesis in the three-spined sticklebacks (no induction) and rainbow trout, but had a significant effect on calcium homeostasis in both species. Intraperitoneal implants of 17β-estradiol reduced CaCO3 production and apparent water absorption in the intestine and increased in tissue calcium stores of seawater-acclimated trout, but fish were able to compensate and showed no overall osmoregulatory disturbance. Waterborne exposure to nonylphenol in freshwater trout was also investigated, but no effects on osmoregulation were found up to 2 ng/l. Overall, estrogens can affect osmoregulation differentially in euryhaline fish species, and sometimes at EDC levels lower than the threshold for reproductive effects (i.e. vitellogenin induction).

Thesis submitted in fulfilment of the requirements of the Master's Degree in technology: Radiography, Durban University of Technology, 2008. / The main aim of this study, was to assess the prevalence of coronary artery calcification in asymptomatic risk and non risk individuals in the South African Indian population, within the age group of 20-70 years. / M