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Sample records for advanced human carotid

  1. Algorithm for quantifying advanced carotid artery atherosclerosis in humans using MRI and active contours

    NASA Astrophysics Data System (ADS)

    Adams, Gareth; Vick, G. W., III; Bordelon, Cassius; Insull, William; Morrisett, Joel

    2002-05-01

    A new algorithm for measuring carotid artery volumes and estimating atherosclerotic plaque volumes from MRI images has been developed and validated using pressure-perfusion-fixed cadaveric carotid arteries. Our method uses an active contour algorithm with the generalized gradient vector field force as the external force to localize the boundaries of the artery on each MRI cross-section. Plaque volume is estimated by an automated algorithm based on estimating the normal wall thickness for each branch of the carotid. Triplicate volume measurements were performed by a single observer on thirty-eight pairs of cadaveric carotid arteries. The coefficient of variance (COV) was used to quantify measurement reproducibility. Aggregate volumes were computed for nine contiguous slices bounding the carotid bifurcation. The median (mean +/- SD) COV for the 76 aggregate arterial volumes was 0.93% (1.47% +/- 1.52%) for the lumen volume, 0.95% (1.06% +/- 0.67%) for the total artery volume, and 4.69% (5.39% +/- 3.97%) for the plaque volume. These results indicate that our algorithm provides repeatable measures of arterial volumes and a repeatable estimate of plaque volume of cadaveric carotid specimens through analysis of MRI images. The algorithm also significantly decreases the amount of time necessary to generate these measurements.

  2. Hemodynamic Effects of Long-term Morphological Changes in the Human Carotid Sinus

    PubMed Central

    Seong, Jaehoon; Jeong, Woowon; Smith, Nataliya; Towner, Rheal A.

    2015-01-01

    Previous investigations of morphology for human carotid artery bifurcation from infancy to young adulthood found substantial growth of the internal carotid artery with advancing age, and the development of the carotid sinus at the root of the internal carotid artery during teen age years. Although the reasons for the appearance of the carotid sinus are not clearly understood yet, it has been hypothesized that the dilation of the carotid sinus serves to support pressure sensing, and slows the blood flow to reduce pulsatility to protect the brain. In order to understand this interesting evolvement at the carotid bifurcation in the aspects of fluid mechanics, we performed in vitro phase-contrast MR flow experiments using compliant silicone replicas of age-dependent carotid artery bifurcations. The silicone models in childhood, adolescence, and adulthood were fabricated using a rapid prototyping technique, and incorporated with a bench-top flow mock circulation loop using a computer-controlled piston pump. The results of the in vitro flow study showed highly complex flow characteristics at the bifurcation in all age-dependent models. However, the highest magnitude of kinetic energy was found at the internal carotid artery in the child model. The high kinetic energy in the internal carotid artery during childhood might be one of the local hemodynamic forces that initiate morphological long-term development of the carotid sinus in the human carotid bifurcation. PMID:25702250

  3. Carotid baroreflex responsiveness in heat-stressed humans

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.

    2000-01-01

    The effects of whole body heating on human baroreflex function are relatively unknown. The purpose of this project was to identify whether whole body heating reduces the maximal slope of the carotid baroreflex. In 12 subjects, carotid-vasomotor and carotid-cardiac baroreflex responsiveness were assessed in normothermia and during whole body heating. Whole body heating increased sublingual temperature (from 36.4 +/- 0.1 to 37.4 +/- 0.1 degrees C, P < 0.01) and increased heart rate (from 59 +/- 3 to 83 +/- 3 beats/min, P < 0. 01), whereas mean arterial blood pressure (MAP) was slightly decreased (from 88 +/- 2 to 83 +/- 2 mmHg, P < 0.01). Carotid-vasomotor and carotid-cardiac responsiveness were assessed by identifying the maximal gain of MAP and heart rate to R wave-triggered changes in carotid sinus transmural pressure. Whole body heating significantly decreased the responsiveness of the carotid-vasomotor baroreflex (from -0.20 +/- 0.02 to -0.13 +/- 0.02 mmHg/mmHg, P < 0.01) without altering the responsiveness of the carotid-cardiac baroreflex (from -0.40 +/- 0.05 to -0.36 +/- 0.02 beats x min(-1) x mmHg(-1), P = 0.21). Carotid-vasomotor and carotid-cardiac baroreflex curves were shifted downward and upward, respectively, to accommodate the decrease in blood pressure and increase in heart rate that accompanied the heat stress. Moreover, the operating point of the carotid-cardiac baroreflex was shifted closer to threshold (P = 0.02) by the heat stress. Reduced carotid-vasomotor baroreflex responsiveness, coupled with a reduction in the functional reserve for the carotid baroreflex to increase heart rate during a hypotensive challenge, may contribute to increased susceptibility to orthostatic intolerance during a heat stress.

  4. Glomus tissue in the vicinity of the human carotid sinus.

    PubMed Central

    Garfia, A

    1980-01-01

    Three of 60 cadavers have shown, in the adventitia or in the adipose tissue from the human carotid sinus region, small islands of tissue richly and typically vascularized and with nerve endings contacting cells like the tissue of the principal carotid body. In two of the cases such 'miniglomera' were single but in the third there were several all on the same side. A modified en bloc silver nitrate reduction stain was used to demonstrate the microvascular arrangements and the nerve endings by light microscopy of serial tangential sections of the carotid bifurcation. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:7364653

  5. Association between carotid diameter and the advanced glycation endproduct Nε-Carboxymethyllysine (CML)

    PubMed Central

    Baumann, Marcus; Richart, Tom; Sollinger, Daniel; Pelisek, Jaroslav; Roos, Marcel; Kouznetsova, Tatiana; Eckstein, Hans-Henning; Heemann, Uwe; Staessen, Jan A

    2009-01-01

    Background Nε-Carboxymethyllysine (CML) is the major non-cross linking advanced glycation end product (AGE). CML is elevated in diabetic patients and apparent in atherosclerotic lesions. AGEs are associated with hypertension and arterial stiffness potentially by qualitative changes of elastic fibers. We investigated whether CML affects carotid and aortic properties in normoglycemic subjects. Methods Hundred-two subjects (age 48.2 ± 11.3 years) of the FLEMENGHO study were stratified according to the median of the plasma CML level (200.8 ng/ml; 25th percentile: 181.6 ng/ml, 75th percentile: 226.1 ng/ml) into "high CML" versus "low CML" as determined by ELISA. Local carotid artery properties, carotid intima media thickness (IMT), aortic pulse wave velocity (PWV), blood pressure and fetuin-A were analyzed. In 26 patients after carotidectomy, CML was visualized using immunohistochemistry. Results According to the CML median, groups were similar for anthropometric and biochemical data. Carotid diameter was enlarged in the "high" CML group (485.7 ± 122.2 versus 421.2 ± 133.2 μm; P < 0.05), in particular in participants with elevated blood pressure and with "high" CML ("low" CML: 377.9 ± 122.2 μm and "high" CML: 514.5 ± 151.6 μm; P < 0.001). CML was associated fetuin-A as marker of vascular inflammation in the whole cohort (r = 0.28; P < 0.01) and with carotid diameter in hypertensive subjects (r = 0.42; P < 0.01). CML level had no effect on aortic stiffness. CML was detected in the subendothelial space of human carotid arteries. Conclusion In normoglycemic subjects CML was associated with carotid diameter without adaptive changes of elastic properties and with fetuin-A as vascular inflammation marker, in particular in subjects with elevated blood pressure. This may suggest qualitative changes of elastic fibers resulting in a defective mechanotransduction, in particular as CML is present in human carotid arteries. PMID:19660101

  6. Cellular properties and chemosensory responses of the human carotid body

    PubMed Central

    Ortega-Sáenz, Patricia; Pardal, Ricardo; Levitsky, Konstantin; Villadiego, Javier; Muñoz-Manchado, Ana Belén; Durán, Rocío; Bonilla-Henao, Victoria; Arias-Mayenco, Ignacio; Sobrino, Verónica; Ordóñez, Antonio; Oliver, María; Toledo-Aral, Juan José; López-Barneo, José

    2013-01-01

    The carotid body (CB) is the major peripheral arterial chemoreceptor in mammals that mediates the acute hyperventilatory response to hypoxia. The CB grows in response to sustained hypoxia and also participates in acclimatisation to chronic hypoxaemia. Knowledge of CB physiology at the cellular level has increased considerably in recent times thanks to studies performed on lower mammals, and rodents in particular. However, the functional characteristics of human CB cells remain practically unknown. Herein, we use tissue slices or enzymatically dispersed cells to determine the characteristics of human CB cells. The adult human CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). We found that GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. Moreover, glomus cells exhibited voltage-dependent Na+, Ca2+ and K+ currents that were qualitatively similar to those reported in lower mammals. These cells responded to hypoxia with an external Ca2+-dependent increase of cytosolic Ca2+ and quantal catecholamine secretion, as reported for other mammalian species. Interestingly, human glomus cells are also responsive to hypoglycaemia and together these two stimuli can potentiate each other's effects. The chemosensory responses of glomus cells are also preserved at an advanced age. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans. PMID:24167224

  7. Natriuretic Peptide Receptor-C is Up-Regulated in the Intima of Advanced Carotid Artery Atherosclerosis

    PubMed Central

    Zayed, Mohamed A; Harring, Scott D; Abendschein, Dana R; Vemuri, Chandu; Lu, Dongsi; Detering, Lisa; Liu, Yongjian; Woodard, Pamela K

    2016-01-01

    Objective Natriuretic peptide receptor-C (NPR-C/NPR-3) is a cell surface protein involved in vascular remodelling that is up-regulated in atherosclerosis. NPR-C expression has not been well characterized in human carotid artery occlusive lesions. We hypothesized that NPR-C expression correlates with intimal features of vulnerable atherosclerotic carotid artery plaque. Methods To test this hypothesis, we evaluated NPR-C expression by immunohistochemistry (IHC) in carotid endarterectomy (CEA) specimens isolated from 18 patients. The grade, location, and co-localization of NPR-C in CEA specimens were evaluated using two tissue analysis techniques. Results Relative to minimally diseased CEA specimens, we observed avid NPR-C tissue staining in the intima of maximally diseased CEA specimens (65%; p=0.06). Specifically, maximally diseased CEA specimens demonstrated increased NPR-C expression in the superficial intima (61%, p=0.17), and deep intima (138% increase; p=0.05). In the superficial intima, NPR-C expression significantly co-localized with vascular smooth muscle cells (VSMCs) and macrophages. The intensity of NPR-C expression was also higher in the superficial intima plaque shoulder and cap regions, and significantly correlated with atheroma and fibroatheroma vulnerable plaque regions (β=1.04, 95% CI=0.46, 1.64). Conclusion These findings demonstrate significant NPR-C expression in the intima of advanced carotid artery plaques. Furthermore, NPR-C expression was higher in vulnerable carotid plaque intimal regions, and correlate with features of advanced disease. Our findings suggest that NPR-C may serve as a potential biomarker for carotid plaque vulnerability and progression, in patients with advanced carotid artery occlusive disease. PMID:27547837

  8. Anatomical and functional characteristics of carotid sinus stimulation in humans

    NASA Technical Reports Server (NTRS)

    Querry, R. G.; Smith, S. A.; Stromstad, M.; Ide, K.; Secher, N. H.; Raven, P. B.

    2001-01-01

    Transmission characteristics of pneumatic pressure to the carotid sinus were evaluated in 19 subjects at rest and during exercise. Either a percutaneous fluid-filled (n = 12) or balloon-tipped catheter (n = 7) was placed at the carotid bifurcation to record internal transmission of external neck pressure/neck suction (NP/NS). Sustained, 5-s pulses, and rapid ramping pulse protocols (+40 to -80 Torr) were recorded. Transmission of pressure stimuli was less with the fluid-filled catheter compared with that of the balloon-tipped catheter (65% vs. 82% negative pressure, 83% vs. 89% positive pressure; P < 0.05). Anatomical location of the carotid sinus averaged 3.2 cm (left) and 3.6 cm (right) from the gonion of the mandible with a range of 0-7.5 cm. Transmission was not altered by exercise or Valsalva maneuver, but did vary depending on the position of the carotid sinus locus beneath the sealed chamber. These data indicate that transmission of external NP/NS was higher than previously recorded in humans, and anatomical variation of carotid sinus location and equipment design can affect transmission results.

  9. Alternation of histone and DNA methylation in human atherosclerotic carotid plaques.

    PubMed

    Greißel, A; Culmes, M; Napieralski, R; Wagner, E; Gebhard, H; Schmitt, M; Zimmermann, A; Eckstein, H-H; Zernecke, A; Pelisek, J

    2015-08-01

    Little is known about epigenetics and its possible role in atherosclerosis. We here analysed histone and DNA methylation and the expression of corresponding methyltransferases in early and advanced human atherosclerotic carotid lesions in comparison to healthy carotid arteries. Western Blotting was performed on carotid plaques from our biobank with early (n=60) or advanced (n=60) stages of atherosclerosis and healthy carotid arteries (n=12) to analyse di-methylation patterns of histone H3 at positions K4, K9 and K27. In atherosclerotic lesions, di-methylation of H3K4 was unaltered and that of H3K9 and H3K27 significantly decreased compared to control arteries. Immunohistochemistry revealed an increased appearance of di-methylated H3K4 in smooth muscle cells (SMCs), a decreased expression of di-methylated H3K9 in SMCs and inflammatory cells, and reduced di-methylated H3K27 in inflammatory cells in advanced versus early atherosclerosis. Expression of corresponding histone methyltransferases MLL2 and G9a was increased in advanced versus early atherosclerosis. Genomic DNA hypomethylation, as determined by PCR for methylated LINE1 and SAT-alpha, was observed in early and advanced plaques compared to control arteries and in cell-free serum of patients with high-grade carotid stenosis compared to healthy volunteers. In contrast, no differences in DNA methylation were observed in blood cells. Expression of DNA-methyltransferase DNMT1 was reduced in atherosclerotic plaques versus controls, DNMT3A was undetectable, and DNMT3B not altered. DNA-demethylase TET1 was increased in atherosclerosisc plaques. The extent of histone and DNA methylation and expression of some corresponding methyltransferases are significantly altered in atherosclerosis, suggesting a possible contribution of epigenetics in disease development. PMID:25993995

  10. Optical detection of structural changes in human carotid atherosclerotic plaque

    NASA Astrophysics Data System (ADS)

    Korol, R. M.; Canham, P. B.; Finlay, H. M.; Hammond, R. R.; Quantz, M.; Ferguson, G. G.; Liu, L. Y.; Lucas, A. R.

    2005-08-01

    Background: Arterial bifurcations are commonly the sites of developing atherosclerotic plaque that lead to arterial occlusions and plaque rupture (myocardial infarctions and strokes). Laser induced fluorescence (LIF) spectroscopy provides an effective nondestructive method supplying spectral information on extracellular matrix (ECM) protein composition, specifically collagen and elastin. Purpose: To investigate regional differences in the ECM proteins -- collagen I, III and elastin in unstable plaque by analyzing data from laser-induced fluorescence spectroscopy of human carotid endarterectomy specimens. Methods: Gels of ECM protein extracts (elastin, collagen types I & III) were measured as reference spectra and internal thoracic artery segments (extra tissue from bypass surgery) were used as tissue controls. Arterial segments and the endarterectomy specimens (n=21) were cut into 5mm cross-sectional rings. Ten fluorescence spectra per sampling area were then recorded at 5 sites per ring with argon laser excitation (357nm) with a penetration depth of 200 μm. Spectra were normalized to maximum intensity and analyzed using multiple regression analysis. Tissue rings were fixed in formalin (within 3 hours of surgery), sectioned and stained with H&E or Movat's Pentachrome for histological analysis. Spectroscopy data were correlated with immunohistology (staining for elastin, collagen types I, III and IV). Results: Quantitative fluorescence for the thoracic arteries revealed a dominant elastin component on the luminal side -- confirmed with immunohistology and known artery structure. Carotid endarterectomy specimens by comparison had a significant decrease in elastin signature and increased collagen type I and III. Arterial spectra were markedly different between the thoracic and carotid specimens. There was also a significant elevation (p<0.05) of collagen type I distal to the bifurcation compared to proximal tissue in the carotid specimens. Conclusion: Fluorescence

  11. The Human Carotid Body Gene Expression and Function in Signaling of Hypoxia and Inflammation.

    PubMed

    Kåhlin, Jessica; Mkrtchian, Souren; Ebberyd, Anette; Eriksson, Lars I; Fagerlund, Malin Jonsson

    2015-01-01

    Although animal carotid body oxygen sensing and signaling has been extensively investigated, the human carotid body remains essentially uncharacterized. Therefore, we aimed to study the human carotid body in terms of morphology, global and specific expression of sensing and signaling genes as well as inflammatory genes. The human carotid body response to brief or prolonged hypoxia was studied in carotid body slices from adult surgical patients and ACh, ATP and cytokine release was analyzed. We demonstrate that the human carotid body expresses key oxygen sensing and signaling genes in similarity with animal carotid bodies with a few diverging data. The human carotid body moreover shows enrichment of genes in the inflammatory response and releases pro and anti-inflammatory cytokines in response to prolonged hypoxia. In response to acute hypoxia the human carotid body releases ACh and ATP and we thus translate previous findings in animal models to human tissue. We conclude that by releasing pro- and anti-inflammatory cytokines during hypoxia the human carotid body displays a structural and functional capacity to participate in sensing and mediating systemic inflammation.

  12. The human carotid body releases acetylcholine, ATP and cytokines during hypoxia.

    PubMed

    Kåhlin, Jessica; Mkrtchian, Souren; Ebberyd, Anette; Hammarstedt-Nordenvall, Lalle; Nordlander, Britt; Yoshitake, Takashi; Kehr, Jan; Prabhakar, Nanduri; Poellinger, Lorenz; Fagerlund, Malin Jonsson; Eriksson, Lars I

    2014-08-01

    Studies on experimental animals established that the carotid bodies are sensory organs for detecting arterial blood O2 levels and that the ensuing chemosensory reflex is a major regulator of cardiorespiratory functions during hypoxia. However, little information is available on the human carotid body responses to hypoxia. The present study was performed on human carotid bodies obtained from surgical patients undergoing elective head and neck cancer surgery. Our results show that exposing carotid body slices to hypoxia for a period as brief as 5 min markedly facilitates the release of ACh and ATP. Furthermore, prolonged hypoxia for 1 h induces an increased release of interleukin (IL)-1β, IL-4, IL-6, IL-8 and IL-10. Immunohistochemical analysis revealed that type 1 cells of the human carotid body express an array of cytokine receptors as well as hypoxia-inducible factor-1α and hypoxia-inducible factor-2α. Taken together, these results demonstrate that ACh and ATP are released from the human carotid body in response to hypoxia, suggesting that these neurotransmitters, as in several experimental animal models, play a role in hypoxic signalling also in the human carotid body. The finding that the human carotid body releases cytokines in response to hypoxia adds to the growing body of information suggesting that the carotid body may play a role in detecting inflammation, providing a link between the immune system and the nervous system.

  13. Assessment of permeation of lipoproteins in human carotid tissue

    NASA Astrophysics Data System (ADS)

    Ghosn, Mohamad G.; Syed, Saba H.; Leba, Michael; Morrisett, Joel D.; Tuchin, Valery V.; Larin, Kirill V.

    2010-02-01

    Cardiovascular disease is among the leading causes of death in the United States. Specifically, atherosclerosis is an increasingly devastating contributor to the tally and has been found to be a byproduct of arterial permeability irregularities in regards to lipoprotein penetration. To further explore arterial physiology and molecular transport, the imaging technique of Optical Coherence Tomography (OCT) was employed. With OCT, the permeation of glucose (MW = 180 Da), low density lipoprotein (LDL; MW = 2.1 × 106 Da), and high density lipoprotein (HDL; MW = 2.5 × 105 Da) in human carotid tissue was studied to determine the effect of different molecular characteristics on permeation in atherosclerotic tissues. The permeability rates calculated from the diffusion of the molecular agents into the abnormal carotid tissue samples is compared to those of normal, healthy tissue. The results show that in the abnormal tissue, the permeation of agents correlate to the size constraints. The larger molecules of LDL diffuse the slowest, while the smallest molecules of glucose diffuse the fastest. However, in normal tissue, LDL permeates at a faster rate than the other two agents, implying the existence of a transport mechanism that facilitates the passage of LDL molecules. These results highlight the capability of OCT as a sensitive and specific imaging technique as well as provide significant information to the understanding of atherosclerosis and its effect on tissue properties.

  14. Impedance-based outflow boundary conditions for human carotid haemodynamics.

    PubMed

    Malvè, M; Chandra, S; García, A; Mena, A; Martínez, M A; Finol, E A; Doblaré, M

    2014-01-01

    In this study, we develop structured tree outflow boundary conditions for modelling the human carotid haemodynamics. The model geometry was reconstructed through computerised tomography scan. Unsteady-state computational fluid dynamic analyses were performed under different conditions using a commercial software package ADINA R&D, Inc., (Watertown, MA, USA) in order to assess the impact of the boundary conditions on the flow variables. In particular, the results showed that the peripheral vessels massively impact the pressure while the flow is relatively unaffected. As an example of application of these outflow conditions, an unsteady fluid-structure interaction (FSI) simulation was carried out and the dependence of the wall shear stress (WSS) on the arterial wall compliance in the carotid bifurcation was studied. In particular, a comparison between FSI and rigid-wall models was conducted. Results showed that the WSS distributions were substantially affected by the diameter variation of the arterial wall. In particular, even similar WSS distributions were found for both cases, and differences in the computed WSS values were also found.

  15. Computational modeling of hypertensive growth in the human carotid artery

    NASA Astrophysics Data System (ADS)

    Sáez, Pablo; Peña, Estefania; Martínez, Miguel Angel; Kuhl, Ellen

    2014-06-01

    Arterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively.

  16. Continuous resetting of the human carotid baroreceptor-cardiac reflex.

    PubMed

    Kasting, G A; Eckberg, D L; Fritsch, J M; Birkett, C L

    1987-04-01

    Although human baroreflex responses have been studied during night as well as day, there has been no attempt to distinguish circadian changes of baroreflex function from those related to sleep. We measured carotid baroreceptor-cardiac reflex responses serially during a 24-h period in 11 normotensive volunteers who were awake and cooperative during testing. We applied sequences of ramped R-wave-triggered neck chamber pressure changes from +40 to -65 mmHg, during held expiration, at 3-h intervals. Subjects maintained their usual sleep-wake cycles but were awakened for three 30-min periods for night testing. There was no systematic change of baroreflex slope during the 24-h period. There were, however, parallel shifts of the entire sigmoid baroreceptor-cardiac reflex response relation along its R-R interval and arterial pressure axes associated with small, but significant, circadian changes of baseline R-R intervals and arterial pressures. Thus, although our data do not point toward major circadian variability of baro-reflex responsiveness, they provide evidence for an ongoing process of human baroreflex resetting.

  17. Computational modeling of hypertensive growth in the human carotid artery

    PubMed Central

    Sáez, Pablo; Peña, Estefania; Martínez, Miguel Angel; Kuhl, Ellen

    2014-01-01

    Arterial hypertension is a chronic medical condition associated with an elevated blood pressure. Chronic arterial hypertension initiates a series of events, which are known to collectively initiate arterial wall thickening. However, the correlation between macrostructural mechanical loading, microstructural cellular changes, and macrostructural adaptation remains unclear. Here, we present a microstructurally motivated computational model for chronic arterial hypertension through smooth muscle cell growth. To model growth, we adopt a classical concept based on the multiplicative decomposition of the deformation gradient into an elastic part and a growth part. Motivated by clinical observations, we assume that the driving force for growth is the stretch sensed by the smooth muscle cells. We embed our model into a finite element framework, where growth is stored locally as an internal variable. First, to demonstrate the features of our model, we investigate the effects of hypertensive growth in a real human carotid artery. Our results agree nicely with experimental data reported in the literature both qualitatively and quantitatively. PMID:25342868

  18. Selective Expression of Galanin in Neuronal-Like Cells of the Human Carotid Body.

    PubMed

    Di Giulio, Camillo; Marconi, Guya Diletta; Zara, Susi; Di Tano, Andrea; Porzionato, Andrea; Pokorski, Mieczyslaw; Cataldi, Amelia; Mazzatenta, Andrea

    2015-01-01

    The carotid body is a neural-crest-derived organ devoted to respiratory homeostasis through sensing changes in blood oxygen levels. The sensory units are the glomeruli composed of clusters of neuronal-like (type I) cells surrounded by glial-like (type II) cells. During chronic hypoxia, the carotid body shows growth, with increasing neuronal-like cell numbers. We are interested in the signals involved in the mechanisms that underlie such response, because they are not well understood and described. Considering that, in literature, galanin is involved in neurotrophic or neuroprotective role in cell proliferation and is expressed in animal carotid body, we investigated its expression in human. Here, we have shown the expression and localisation of galanin in the human carotid body.

  19. Neurotrophic Properties, Chemosensory Responses and Neurogenic Niche of the Human Carotid Body.

    PubMed

    Ortega-Sáenz, Patricia; Villadiego, Javier; Pardal, Ricardo; Toledo-Aral, Juan José; López-Barneo, José

    2015-01-01

    The carotid body (CB) is a polymodal chemoreceptor that triggers the hyperventilatory response to hypoxia necessary for the maintenance of O(2) homeostasis essential for the survival of organs such as the brain or heart. Glomus cells, the sensory elements in the CB, are also sensitive to hypercapnia, acidosis and, although less generally accepted, hypoglycemia. Current knowledge on CB function is mainly based on studies performed on lower mammals, but the information on the human CB is scant. Here we describe the structure, neurotrophic properties, and cellular responses to hypoxia and hypoglycemia of CBs dissected from human cadavers. The adult CB parenchyma contains clusters of chemosensitive glomus (type I) and sustentacular (type II) cells as well as nestin-positive progenitor cells. This organ also expresses high levels of the dopaminotrophic glial cell line-derived neurotrophic factor (GDNF). GDNF production and the number of progenitor and glomus cells were preserved in the CBs of human subjects of advanced age. As reported for other mammalian species, glomus cells responded to hypoxia by external Ca(2+)-dependent increase of cytosolic [Ca(2+)] and quantal catecholamine release. Human glomus cells are also responsive to hypoglycemia and together the two stimuli, hypoxia and hypoglycemia, can potentiate each other's effects. The chemo-sensory responses of glomus cells are also preserved at an advanced age. Interestingly, a neurogenic niche similar to that recently described in rodents is also preserved in the adult human CB. These new data on the cellular and molecular physiology of the CB pave the way for future pathophysiological studies involving this organ in humans.

  20. Effects of acute hyperthermia on the carotid baroreflex control of heart rate in humans

    NASA Astrophysics Data System (ADS)

    Yamazaki, F.; Sagawa, S.; Torii, R.; Endo, Y.; Shiraki, K.

    The purpose of this study was to examine the effect of hyperthermia on the carotid baroreceptor-cardiac reflexes in humans. Nine healthy males underwent acute hyperthermia (esophageal temperature 38.0° C) produced by hot water-perfused suits. Beat-to-beat heart rate (HR) responses were determined during positive and negative R-wave-triggered neck pressure steps from +40 to -65 mm Hg during normothermia and hyperthermia. The carotid baroreceptor-cardiac reflex sensitivity was evaluated from the maximum slope of the HR response to changes in carotid distending pressure. Buffering capacity of the HR response to carotid distending pressure was evaluated in % from a reference point calculated as (HR at 0 mm Hg neck pressure-minimum HR)/HR range ×100. An upward shift of the curve was evident in hyperthermia because HR increased from 57.7+/-2.4 beats/min in normothermia to 88.7+/-4.1 beats/min in hyperthermia (P<0.05) without changes in mean arterial pressure. The maximum slope of the curve in hyperthermia was similar to that in normothermia. The reference point was increased (P<0.05) during hyperthermia. These results suggest that the sensitivity of the carotid baroreflex of HR remains unchanged in hyperthermia. However, the capacity for tachycardia response to rapid onset of hypotension is reduced and the capacity for bradycardia response to sudden hypertension is increased during acute hyperthermia.

  1. 12- and 15-lipoxygenases in human carotid atherosclerotic lesions: Associations with cerebrovascular symptoms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lipoxygenase (ALOX) enzymes are implicated in both pro- and anti-atherogenic processes. The aim of this study was to investigate mRNA expression of 12- and 15-lipoxygenases (ALOX12, ALOX12B, ALOX15, ALOX15B) and the atypical ALOXE3 in human carotid atherosclerotic lesions, in relation to cerebrovasc...

  2. Comparison of aortic and carotid baroreflex stimulus-response characteristics in humans

    NASA Technical Reports Server (NTRS)

    Smith, S. A.; Querry, R. G.; Fadel, P. J.; Weiss, M. W.; Olivencia-Yurvati, A.; Shi, X.; Raven, P. B.

    2001-01-01

    In order to characterize the stimulus-response relationships of the arterial, aortic, and carotid baroreflexes in mediating cardiac chronotropic function, we measured heart rate (HR) responses elicited by acute changes in mean arterial pressure (MAP) and carotid sinus pressure (CSP) in 11 healthy individuals. Arterial (aortic + carotid) baroreflex control of HR was quantified using ramped changes in MAP induced by bolus injection of phenylephrine (PE) and sodium nitroprusside (SN). To assess aortic-cardiac responses, neck pressure (NP) and suction (NS) were applied during PE and SN administration, respectively, to counter alterations in CSP thereby isolating the aortic baroreflex. Graded levels of NP and NS were delivered to the carotid sinus using a customized neck collar device to assess the carotid-cardiac baroreflex, independent of drug infusion. The operating characteristics of each reflex were determined from the logistic function of the elicited HR response to the induced change in MAP. The arterial pressures at which the threshold was located on the stimulus-response curves determined for the arterial, aortic and carotid baroreflexes were not significantly different (72+/-4, 67+/-3, and 72+/-4 mm Hg, respectively, P > 0.05). Similarly, the MAP at which the saturation of the reflex responses were elicited did not differ among the baroreflex arcs examined (98+/-3, 99+/-2, and 102+/-3 mm Hg, respectively). These data suggest that the baroreceptor populations studied operate over the same range of arterial pressures. This finding indicates each baroreflex functions as both an important anti-hypotensive and anti-hypertensive mechanism. In addition, this investigation describes a model of aortic baroreflex function in normal healthy humans, which may prove useful in identifying the origin of baroreflex dysfunction in disease- and training-induced conditions.

  3. Coexpression of Galanin and Nestin in the Chemoreceptor Cells of the Human Carotid Body.

    PubMed

    Mazzatenta, Andrea; Marconi, Guya D; Macchi, Veronica; Porzionato, Andrea; Cataldi, Amelia; Di Giulio, Camillo; Pokorski, Mieczyslaw

    2016-01-01

    The carotid body is a highly specialized chemoreceptive organ of neural crest origin whose role is to detect changes in arterial oxygen content. The sensory units are the chemoreceptor cells, which are neuronal-like cells, surrounded by sustentacular or glial-like cells. It is suggested that the carotid body contains self-renewing multipotent stem cells, which are putatively represented by glial-like sustentacular cells. The mechanisms of renewal of neuronal-like cells are unclear. Recently, we have demonstrated the expression of galanin, a peptide promoting neurogenesis, in chemoreceptor cells in the human CB. Thus, in the present study we seek to determine whether galanin expression in chemoreceptor cells could be matched with that of nestin, a peptide that is a marker of multipotent neural stem cells, or rather with the glial fibrillary acidic protein (GFAP), a marker for glial cells. The latter would underscore the pluasibly essential role of sustentacular cells in the self-renewal capability of chemorecetors. We found that galanin expression is matched with nestin in chemoreceptor cells of the human carotid body, but not with that of GFAP. Thus, galanin expression in chemoreceptor cells could provide a signal for neurogenesis and chemoreceptor cell differentiation in the carotid body.

  4. Role of the carotid body chemoreceptors in baroreflex control of blood pressure during hypoglycaemia in humans.

    PubMed

    Limberg, Jacqueline K; Taylor, Jennifer L; Dube, Simmi; Basu, Rita; Basu, Ananda; Joyner, Michael J; Wehrwein, Erica A

    2014-04-01

    Activation of the carotid body chemoreceptors with hypoxia alters baroreceptor-mediated responses. We aimed to examine whether this relationship can be translated to other chemoreceptor stimuli (i.e. hypoglycaemia) by testing the following hypotheses: (i) activation of the carotid body chemoreceptors with hypoglycaemia would reduce spontaneous cardiac baroreflex sensitivity (sCBRS) in healthy humans; and (ii) desensitization of the carotid chemoreceptors with hyperoxia would restore sCBRS to baseline levels during hypoglycaemia. Ten young healthy adults completed two 180 min hyperinsulinaemic [2 mU (kg fat-free mass)(-1) min(-1)], hypoglycaemic (∼ 3.2 μmol ml(-1)) clamps, separated by at least 1 week and randomized to normoxia (arterial partial pressure of O2, 122 ± 10 mmHg) or hyperoxia (arterial partial pressure of O2, 424 ± 123 mmHg; to blunt activation of the carotid body glomus cells). Changes in heart rate, blood pressure, plasma catecholamines, heart rate variability (HRV) and sCBRS were assessed. During hypoglycaemia, HRV and sCBRS were reduced (P < 0.05) and the baroreflex working range was shifted to higher heart rates. When hyperoxia was superimposed on hypoglycaemia, there was a greater reduction in blood pressure and a blunted rise in heart rate when compared with normoxic conditions (P < 0.05); however, there was no detectable effect of hyperoxia on sCBRS or HRV during hypoglycaemia (P > 0.05). In summary, hypoglycaemia-mediated changes in HRV and sCBRS cannot be attributed exclusively to the carotid chemoreceptors; however, the chemoreceptors appear to play a role in resetting the baroreflex working range during hypoglycaemia.

  5. Elevated expression of mechanosensory polycystins in human carotid atherosclerotic plaques: association with p53 activation and disease severity

    PubMed Central

    Varela, Aimilia; Piperi, Christina; Sigala, Fragiska; Agrogiannis, George; Davos, Constantinos H.; Andri, Maria-Anastasia; Manopoulos, Christos; Tsangaris, Sokrates; Basdra, Efthimia K.; Papavassiliou, Athanasios G.

    2015-01-01

    Atherosclerotic plaque formation is associated with irregular distribution of wall shear stress (WSS) that modulates endothelial function and integrity. Polycystins (PC)-1/-2 constitute a flow-sensing protein complex in endothelial cells, able to respond to WSS and induce cell-proliferation changes leading to atherosclerosis. An endothelial cell-culture system of measurable WSS was established to detect alterations in PCs expression under conditions of low- and high-oscillatory shear stress in vitro. PCs expression and p53 activation as a regulator of cell proliferation were further evaluated in vivo and in 69 advanced human carotid atherosclerotic plaques (AAPs). Increased PC-1/PC-2 expression was observed at 30–60 min of low shear stress (LSS) in endothelial cells. Elevated PC-1 expression at LSS was followed by p53 potentiation. PCs immunoreactivity localizes in areas with macrophage infiltration and neovascularization. PC-1 mRNA and protein levels were significantly higher than PC-2 in stable fibroatherotic (V) and unstable/complicated (VI) AAPs. Elevated PC-1 immunostaining was detected in AAPs from patients with diabetes mellitus, dyslipidemia, hypertension and carotid stenosis, at both arteries (50%) or in one artery (90%). PCs seem to participate in plaque formation and progression. Since PC-1 upregulation coincides with p38 and p53 activation, a potential interplay of these molecules in atherosclerosis induction is posed. PMID:26286632

  6. Lattice Boltzmann method simulating hemodynamics in the three-dimensional stenosed and recanalized human carotid bifurcations

    NASA Astrophysics Data System (ADS)

    Kang, XiuYing

    2015-01-01

    By using the lattice Boltzmann method (LBM) pulsatile blood flows were simulated in three-dimensional moderate stenosed and recanalized carotid bifurcations to understand local hemodynamics and its relevance in arterial atherosclerosis formation and progression. The helical flow patterns, secondary flow and wall dynamical pressure spatiotemporal distributions were investigated, which leads to the disturbed shear forces in the carotid artery bifurcations. The wall shear stress distributions indicated by time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and the relative residence time (RRT) in a cardiac cycle revealed the regions where atherosclerotic plaques are prone to form, extend or rupture. This study also illustrates the point that locally disturbed flow may be considered as an indicator for early atherosclerosis diagnosis. Additionally the present work demonstrates the robust and highly efficient advantages of the LBM for the hemodynamics study of the human blood vessel system.

  7. Regional calcium distribution and ultrasound images of the vessel wall in human carotid arteries

    NASA Astrophysics Data System (ADS)

    Szikszai, Z.; Kertész, Zs.; Uzonyi, I.; Szíki, G. Á.; Magyar, M. T.; Molnár, S.; Ida, Y.; Csiba, L.

    2005-04-01

    Arterial calcification can take place at two sites in the vessel wall: the intima and the media. Intimal calcification occurs exclusively within atherosclerotic plaques, while medial calcification may develop independently. Extensive calcified plaques in the carotid arteries can be easily detected by B-mode ultrasonic imaging. The calcium content might correlate with the ultrasound reflectance of the vessel wall, and could be a surrogate marker for arteriosclerosis. In this study, segments of human carotid arteries collected at autopsy were examined by ultrasonography in vitro and calcium distributional maps of sections from the same segments were determined by particle induced X-ray emission. Our aim was to make a first step towards investigating the relationship between the calcium distributional maps and the respective ultrasound images.

  8. Distinct Differences on Neointima Formation in Immunodeficient and Humanized Mice after Carotid or Femoral Arterial Injury

    PubMed Central

    Moser, Jill; van Ark, Joris; van Dijk, Marcory C.; Greiner, Dale L.; Shultz, Leonard D.; van Goor, Harry; Hillebrands, Jan-Luuk

    2016-01-01

    Percutaneous coronary intervention is widely adopted to treat patients with coronary artery disease. However, restenosis remains an unsolved clinical problem after vascular interventions. The role of the systemic and local immune response in the development of restenosis is not fully understood. Hence, the aim of the current study was to investigate the role of the human immune system on subsequent neointima formation elicited by vascular injury in a humanized mouse model. Immunodeficient NOD.Cg-PrkdcscidIL2rgtm1Wjl(NSG) mice were reconstituted with human (h)PBMCs immediately after both carotid wire and femoral cuff injury were induced in order to identify how differences in the severity of injury influenced endothelial regeneration, neointima formation, and homing of human inflammatory and progenitor cells. In contrast to non-reconstituted mice, hPBMC reconstitution reduced neointima formation after femoral cuff injury whereas hPBMCs promoted neointima formation after carotid wire injury 4 weeks after induction of injury. Neointimal endothelium and smooth muscle cells in the injured arteries were of mouse origin. Our results indicate that the immune system may differentially respond to arterial injury depending on the severity of injury, which may also be influenced by the intrinsic properties of the arteries themselves, resulting in either minimal or aggravated neointima formation. PMID:27759053

  9. Ex vivo differential phase contrast and magnetic resonance imaging for characterization of human carotid atherosclerotic plaques.

    PubMed

    Meletta, Romana; Borel, Nicole; Stolzmann, Paul; Astolfo, Alberto; Klohs, Jan; Stampanoni, Marco; Rudin, Markus; Schibli, Roger; Krämer, Stefanie D; Herde, Adrienne Müller

    2015-10-01

    Non-invasive detection of specific atherosclerotic plaque components related to vulnerability is of high clinical relevance to prevent cerebrovascular events. The feasibility of magnetic resonance imaging (MRI) for characterization of plaque components was already demonstrated. We aimed to evaluate the potential of ex vivo differential phase contrast X-ray tomography (DPC) to accurately characterize human carotid plaque components in comparison to high field multicontrast MRI and histopathology. Two human plaque segments, obtained from carotid endarterectomy, classified according to criteria of the American Heart Association as stable and unstable plaque, were examined by ex vivo DPC tomography and multicontrast MRI (T1-, T2-, and proton density-weighted imaging, magnetization transfer contrast, diffusion-weighted imaging). To identify specific plaque components, the plaques were subsequently sectioned and stained for fibrous and cellular components, smooth muscle cells, hemosiderin, and fibrin. Histological data were then matched with DPC and MR images to define signal criteria for atherosclerotic plaque components. Characteristic structures, such as the lipid and necrotic core covered by a fibrous cap, calcification and hemosiderin deposits were delineated by histology and found with excellent sensitivity, resolution and accuracy in both imaging modalities. DPC tomography was superior to MRI regarding resolution and soft tissue contrast. Ex vivo DPC tomography allowed accurate identification of structures and components of atherosclerotic plaques at different lesion stages, in good correlation with histopathological findings.

  10. Distribution of alkaline phosphatase, osteopontin, RANK ligand and osteoprotegerin in calcified human carotid atheroma.

    PubMed

    Higgins, Catherine L; Isbilir, Salim; Basto, Pamela; Chen, Iou Yih; Vaduganathan, Muthiah; Vaduganathan, Periyanan; Reardon, Michael J; Lawrie, Gerald; Peterson, Leif; Morrisett, Joel D

    2015-10-01

    Ectopic vascular calcification is a significant component of atherosclerotic disease. Osteopontin (OPN), Osteoprotegerin (OPG), Receptor Activator of NFκB Ligand (RANKL), and alkaline phosphatase (ALP) are each thought to play central roles in the calcification or demineralization of atherosclerotic lesions. Abnormalities in the balance of these proteins may lead to perturbations in bone remodeling and arterial calcification. The purpose of this study was to measure the distribution of these proteins in human carotid lesions and to elucidate possible mechanism(s) whereby they control the deposition or depletion of arterial calcification. Thirty-three patients who had undergone carotid endarterectomy (CEA) within the previous 18 months and 11 control patients were enrolled. CEA specimens were analyzed by EBCT for calcification content in terms of Agatston (AGAT) and Volume scores. CEA specimens were then cut into 5 mm segments which were homogenized and extracted. Extracts were analyzed for tissue levels of calcium, phosphorus, ALP, OPN, RANKL, and OPG. Fasting blood samples were analyzed for the same components. In CEA tissue segments, the calcification levels (CHA AGAT) were inversely associated with the levels of OPG (r = -0.432/-0.579, p < 0.05) and positively associated with the levels of RANKL (r = 0.332/0.415, p < 0.05). In turn, the tissue levels of OPG were associated with homologous serum levels of OPG (r = 0.820/0.389, p < 0.001), and the tissue levels of RANKL were associated with the serum levels of homologous RANKL (r = 0.739/0.666, p < 0.0001). This study suggests that serum levels of OPG and RANKL may be useful biomarkers for estimating the degree of calcification in carotid atherosclerotic lesions. PMID:26307009

  11. Carotid Endarterectomy

    MedlinePlus

    ... the carotid arteries. This limits or blocks the flow of oxygen-rich blood to your brain, which can lead to a stroke. Carotid Arteries Figure A shows ... normal carotid artery that has normal blood flow. Figure C show the inside of a carotid ...

  12. Association between Human Plasma Chondroitin Sulfate Isomers and Carotid Atherosclerotic Plaques.

    PubMed

    Zinellu, Elisabetta; Lepedda, Antonio Junior; Cigliano, Antonio; Pisanu, Salvatore; Zinellu, Angelo; Carru, Ciriaco; Bacciu, Pietro Paolo; Piredda, Franco; Guarino, Anna; Spirito, Rita; Formato, Marilena

    2012-01-01

    Several studies have evidenced variations in plasma glycosaminoglycans content in physiological and pathological conditions. In normal human plasma GAGs are present mainly as undersulfated chondroitin sulfate (CS). The aim of the present study was to evaluate possible correlations between plasma CS level/structure and the presence/typology of carotid atherosclerotic lesion. Plasma CS was purified from 46 control subjects and 47 patients undergoing carotid endarterectomy showing either a soft or a hard plaque. The concentration and structural characteristics of plasma CS were assessed by capillary electrophoresis of constituent unsaturated fluorophore-labeled disaccharides. Results showed that the concentration of total CS isomers was increased by 21.4% (P < 0.01) in plasma of patients, due to a significant increase of undersulfated CS. Consequently, in patients the plasma CS charge density was significantly reduced with respect to that of controls. After sorting for plaque typology, we found that patients with soft plaques and those with hard ones differently contribute to the observed changes. In plasma from patients with soft plaques, the increase in CS content was not associated with modifications of its sulfation pattern. On the contrary, the presence of hard plaques was associated with CS sulfation pattern modifications in presence of quite normal total CS isomers levels. These results suggest that the plasma CS content and structure could be related to the presence and the typology of atherosclerotic plaque and could provide a useful diagnostic tool, as well as information on the molecular mechanisms responsible for plaque instability.

  13. Device for rapid quantification of human carotid baroreceptor-cardiac reflex responses.

    PubMed

    Sprenkle, J M; Eckberg, D L; Goble, R L; Schelhorn, J J; Halliday, H C

    1986-02-01

    We designed, constructed, and evaluated a new device to characterize the human carotid baroreceptor-cardiac reflex response relation rapidly. We designed this system for study of reflex responses of astronauts before, during, and after space travel. The system comprises a new tightly sealing silicone rubber neck chamber, a stepping motor-driven electro-deposited nickel bellows pressure system, capable of delivering sequential R-wave-triggered neck chamber pressure changes between +40 and -65 mmHg, and a microprocessor-based electronics system for control of pressure steps and analysis and display of responses. This new system provokes classic sigmoid baroreceptor-cardiac reflex responses with threshold, linear, and saturation ranges in most human volunteers during one held expiration.

  14. Intraoperative radiation of canine carotid artery, internal jugular vein, and vagus nerve. Therapeutic applications in the management of advanced head and neck cancers

    SciTech Connect

    Mittal, B.B.; Pelzer, H.; Tsao, C.S.; Ward, W.F.; Johnson, P.; Friedman, C.; Sisson, G.A. Sr.; Kies, M. )

    1990-12-01

    As a step in the application of intraoperative radiotherapy (IORT) for treating advanced head and neck cancers, preliminary information was obtained on the radiation tolerance of the canine common carotid artery, internal jugular vein, and vagus nerve to a single, high-dose electron beam. Both sides of the neck of eight mongrel dogs were operated on to expose an 8-cm segment of common carotid artery, internal jugular vein, and vagus nerve. One side of the neck was irradiated, using escalating doses of 2500, 3500, 4500, and 5500 cGy. The contralateral side of the neck served as the unirradiated control. At 3 and 6 months after IORT, one dog at each dose level was killed. None of the dogs developed carotid bleeding at any time after IORT. Light microscopic investigations using hematoxylin-eosin staining on the common carotid artery and internal jugular vein showed no consistent changes that suggested radiation damage; however, the Masson trichrome stain and hydroxyproline concentration of irradiated common carotid artery indicated an increase in the collagen content of the tunica media. Marked changes in the irradiated vagus nerve were seen, indicating severe demyelination and loss of nerve fibers, which appeared to be radiation-dose dependent. Four patients with advanced recurrent head and neck cancer were treated with surgical resection and IORT without any acute or subacute complications. The role of IORT as a supplement to surgery, external beam irradiation, and chemotherapy in selected patients with advanced head and neck cancer needs further exploration.

  15. Carotid chemoreceptor modulation of blood flow during exercise in healthy humans.

    PubMed

    Stickland, Michael K; Fuhr, Desi P; Haykowsky, Mark J; Jones, Kelvin E; Paterson, D Ian; Ezekowitz, Justin A; McMurtry, M Sean

    2011-12-15

    Carotid chemoreceptor (CC) inhibition reduces sympathetic nervous outflow in exercising dogs and humans. We sought to determine if CC suppression increases muscle blood flow in humans during exercise and hypoxia. Healthy subjects (N = 13) were evaluated at rest and during constant-work leg extension exercise while exposed to either normoxia or hypoxia (inspired O(2) tension, F(IO(2)), ≈ 0.12, target arterial O(2) saturation = 85%). Subjects breathed hyperoxic gas (F(IO(2)) ≈ 1.0) and/or received intravenous dopamine to inhibit the CC while femoral arterial blood flow data were obtained continuously with pulsed Doppler ultrasound. Exercise increased heart rate, mean arterial pressure, femoral blood flow and conductance compared to rest. Transient hyperoxia had no significant effect on blood flow at rest, but increased femoral blood flow and conductance transiently during exercise without changing blood pressure. Similarly, dopamine had no effect on steady-state blood flow at rest, but increased femoral blood flow and conductance during exercise. The transient vasodilatory response observed by CC inhibition with hyperoxia during exercise could be blocked with simultaneous CC inhibition with dopamine. Despite evidence of dopamine reducing ventilation during hypoxia, no effect on femoral blood flow, conductance or mean arterial pressure was observed either at rest or during exercise with CC inhibition with dopamine while breathing hypoxia. These findings indicate that the carotid chemoreceptor contributes to skeletal muscle blood flow regulation during normoxic exercise in healthy humans, but that the influence of the CC on blood flow regulation in hypoxia is limited.

  16. Carotid chemoreceptor modulation of blood flow during exercise in healthy humans.

    PubMed

    Stickland, Michael K; Fuhr, Desi P; Haykowsky, Mark J; Jones, Kelvin E; Paterson, D Ian; Ezekowitz, Justin A; McMurtry, M Sean

    2011-12-15

    Carotid chemoreceptor (CC) inhibition reduces sympathetic nervous outflow in exercising dogs and humans. We sought to determine if CC suppression increases muscle blood flow in humans during exercise and hypoxia. Healthy subjects (N = 13) were evaluated at rest and during constant-work leg extension exercise while exposed to either normoxia or hypoxia (inspired O(2) tension, F(IO(2)), ≈ 0.12, target arterial O(2) saturation = 85%). Subjects breathed hyperoxic gas (F(IO(2)) ≈ 1.0) and/or received intravenous dopamine to inhibit the CC while femoral arterial blood flow data were obtained continuously with pulsed Doppler ultrasound. Exercise increased heart rate, mean arterial pressure, femoral blood flow and conductance compared to rest. Transient hyperoxia had no significant effect on blood flow at rest, but increased femoral blood flow and conductance transiently during exercise without changing blood pressure. Similarly, dopamine had no effect on steady-state blood flow at rest, but increased femoral blood flow and conductance during exercise. The transient vasodilatory response observed by CC inhibition with hyperoxia during exercise could be blocked with simultaneous CC inhibition with dopamine. Despite evidence of dopamine reducing ventilation during hypoxia, no effect on femoral blood flow, conductance or mean arterial pressure was observed either at rest or during exercise with CC inhibition with dopamine while breathing hypoxia. These findings indicate that the carotid chemoreceptor contributes to skeletal muscle blood flow regulation during normoxic exercise in healthy humans, but that the influence of the CC on blood flow regulation in hypoxia is limited. PMID:22025661

  17. Tomographic particle image velocimetry investigation of the flow in a modeled human carotid artery bifurcation

    NASA Astrophysics Data System (ADS)

    Buchmann, N. A.; Atkinson, C.; Jeremy, M. C.; Soria, J.

    2011-04-01

    Hemodynamic forces within the human carotid artery are well known to play a key role in the initiation and progression of vascular diseases such as atherosclerosis. The degree and extent of the disease largely depends on the prevailing three-dimensional flow structure and wall shear stress (WSS) distribution. This work presents tomographic PIV (Tomo-PIV) measurements of the flow structure and WSS in a physiologically accurate model of the human carotid artery bifurcation. The vascular geometry is reconstructed from patient-specific data and reproduced in a transparent flow phantom to demonstrate the feasibility of Tomo-PIV in a complex three-dimensional geometry. Tomographic reconstruction is performed with the multiplicative line-of-sight (MLOS) estimation and simultaneous multiplicative algebraic reconstruction (SMART) technique. The implemented methodology is validated by comparing the results with Stereo-PIV measurements in the same facility. Using a steady flow assumption, the measurement error and RMS uncertainty are directly inferred from the measured velocity field. It is shown that the measurement uncertainty increases for increasing light sheet thickness and increasing velocity gradients, which are largest near the vessel walls. For a typical volume depth of 6 mm (or 256 pixel), the analysis indicates that the velocity derived from 3D cross-correlation can be measured within ±2% of the maximum velocity (or ±0.2 pixel) near the center of the vessel and within ±5% (±0.6 pixel) near the vessel wall. The technique is then applied to acquire 3D-3C velocity field data at multiple axial locations within the carotid artery model, which are combined to yield the flow field and WSS in a volume of approximately 26 mm × 27 mm × 60 mm. Shear stress is computed from the velocity gradient tensor and a method for inferring the WSS distribution on the vessel wall is presented. The results indicate the presence of a complex and three-dimensional flow structure, with

  18. Human-derived nanoparticles and vascular response to injury in rabbit carotid arteries: proof of principle.

    PubMed

    Schwartz, Maria A K; Lieske, John C; Kumar, Vivek; Farell-Baril, Gerard; Miller, Virginia M

    2008-01-01

    Self-calcifying, self-replicating nanoparticles have been isolated from calcified human tissues. However, it is unclear if these nanoparticles participate in disease processes. Therefore, this study was designed to preliminarily test the hypothesis that human-derived nanoparticles are causal to arterial disease processes. One carotid artery of 3 kg male rabbits was denuded of endothelium; the contralateral artery remained unoperated as a control. Each rabbit was injected intravenously with either saline, calcified, or decalcified nanoparticles cultured from calcified human arteries or kidney stones. After 35 days, both injured and control arteries were removed for histological examination. Injured arteries from rabbits injected with saline showed minimal, eccentric intimal hyperplasia. Injured arteries from rabbits injected with calcified kidney stone- and arterial-derived nanoparticles occluded, sometimes with canalization. The calcified kidney stone-derived nanoparticles caused calcifications within the occlusion. Responses to injury in rabbits injected with decalcified kidney stone-derived nanoparticles were similar to those observed in saline-injected animals. However, decalcified arterial-derived nanoparticles produced intimal hyperplasia that varied from moderate to occlusion with canalization and calcification. This study offers the first evidence that there may be a causal relationship between human-derived nanoparticles and response to injury including calcification in arteries with damaged endothelium. PMID:18686783

  19. Physical human lumen carotid reconstruction: life-size models by rapid prototyping

    NASA Astrophysics Data System (ADS)

    Pili, Piero; Murgia, Fabrizio; Pusceddu, Gabriella; Franzoni, Gregorio; Tuveri, Massimiliano

    2003-05-01

    Rapid Prototyping (RP) is a technique used in industry for manufacturing prototypes. Its capability to physically reproduce geometrical complex shapes is getting increasing interest in many fields of medicine. In the field of vascular surgery, replicas of artery lumen have utility in complex cases or when standard imaging is felt to be equivocal. Replicas can also facilitate experimental studies of computational vascular fluid-dynamics permitting in-vitro reproductions of blood flow in living subjects before and after surgery. The VIrtual VAscular (VIVA) project at CRS4, developed a system able to process three-dimensional (3D) datasets extracted from a Computer Tomography (CT) apparatus, visualize them, reconstruct the geometry of arteries of specific patients, and simulate blood flow in them. In this paper, the applicability of RP techniques to VIVA's real size replicas of an autoptic carotid vessel lumen is presented and an overview of the RP based system developed is provided. The techniques used in our prototype are discussed and experimental results for the creation of a human carotid lumen replica are analyzed. We discuss in detail the pipeline of manufacturing process: 3D geometric reconstruction from segmented points, geometry tessellation, STL (Stereo Lithography format) conversion. Moreover we illustrate some technical details of the specific RP technique used to build the lumen replicas, which is called Fused Deposition Modelling (FDM), the materials used for prototypes, throughput time and costs of the FDM models realized. The system is totally based on open-source software. This enables us to control each step of the pipeline, from data acquisition to STL export file. In this context, we present main sources of error encountered during all manufacturing process stages.

  20. Effect of dynamic exercise on human carotid-cardiac baroreflex latency

    NASA Technical Reports Server (NTRS)

    Potts, J. T.; Raven, P. B.

    1995-01-01

    We compared the beat-to-beat responses of heart rate (HR) after brief activation of carotid baroreceptors in resting humans with the responses obtained during mild-to-moderate levels of dynamic exercise [25 and 50% of peak O2 uptake (VO2peak)] to investigate the effect of exercise on baroreflex latency. Carotid baroreceptors were activated by a pressure pulse (5 s) of neck suction (NS, -80 Torr) and neck pressure (NP, +40 Torr) during held expiration. At rest the peak change in HR to NS/NP occurred during the first several heartbeats (1st-3rd beat), whereas during mild and moderate exercise peak HR responses occurred near the end of the NS/NP pulse (6th-8th beat). In contrast, time (s) to the peak change in HR was not different between rest and exercise (P > 0.05). Reflex tachycadia to NP progressively decreased during exercise (17 +/- 3, 10 +/- 1, and 4 +/- 1% of control, rest vs. 25% VO2peak, vs. 50% VO2peak, respectively, P < 0.05), and a strong positive correlation was found between the magnitude of the reflex tachycardia and a measure of HR variability (cardiac vagal tone index, r = 0.74, P < 0.0001). Reflex bradycardia to NS gradually increased during exercise (13 +/- 2, 17 +/- 2, and 18 +/- 2% of control, rest vs. 25% VO2peak, vs. 50% VO2peak, respectively, P = 0.10) and was negatively correlated with cardiac vagal tone (r = 0.42, P < 0.06).(ABSTRACT TRUNCATED AT 250 WORDS).

  1. Matrix metalloproteinase-2 of human carotid atherosclerotic plaques promotes platelet activation. Correlation with ischaemic events.

    PubMed

    Lenti, Massimo; Falcinelli, Emanuela; Pompili, Marcella; de Rango, Paola; Conti, Valentina; Guglielmini, Giuseppe; Momi, Stefania; Corazzi, Teresa; Giordano, Giuseppe; Gresele, Paolo

    2014-06-01

    Purified active matrix metalloproteinase-2 (MMP-2) is able to promote platelet aggregation. We aimed to assess the role of MMP-2 expressed in atherosclerotic plaques in the platelet-activating potential of human carotid plaques and its correlation with ischaemic events. Carotid plaques from 81 patients undergoing endarterectomy were tested for pro-MMP-2 and TIMP-2 content by zymography and ELISA. Plaque extracts were incubated with gel-filtered platelets from healthy volunteers for 2 minutes before the addition of a subthreshold concentration of thrombin receptor activating peptide-6 (TRAP-6) and aggregation was assessed. Moreover, platelet deposition on plaque extracts immobilised on plastic coverslips under high shear-rate flow conditions was measured. Forty-three plaque extracts (53%) potentiated platelet aggregation (+233 ± 26.8%), an effect prevented by three different specific MMP-2 inhibitors (inhibitor II, TIMP-2, moAb anti-MMP-2). The pro-MMP-2/TIMP-2 ratio of plaques potentiating platelet aggregation was significantly higher than that of plaques not potentiating it (3.67 ± 1.21 vs 1.01 ± 0.43, p<0.05). Moreover, the platelet aggregation-potentiating effect, the active-MMP-2 content and the active MMP-2/pro-MMP-2 ratio of plaque extracts were significantly higher in plaques from patients who developed a subsequent major cardiovascular event. In conclusion, atherosclerotic plaques exert a prothrombotic effect by potentiating platelet activation due to their content of MMP-2; an elevated MMP-2 activity in plaques is associated with a higher rate of subsequent ischaemic cerebrovascular events. PMID:24499865

  2. Advanced glycation end products, carotid atherosclerosis, and circulating endothelial progenitor cells in patients with end-stage renal disease.

    PubMed

    Ueno, Hiroki; Koyama, Hidenori; Fukumoto, Shinya; Tanaka, Shinji; Shoji, Takuhito; Shoji, Tetsuo; Emoto, Masanori; Tahara, Hideki; Inaba, Masaaki; Kakiya, Ryusuke; Tabata, Tsutomu; Miyata, Toshio; Nishizawa, Yoshiki

    2011-04-01

    Numbers of endothelial progenitor cells (EPCs) have been shown to be decreased in subjects with end-stage renal disease (ESRD), the mechanism of which remained poorly understood. In this study, mutual association among circulating EPC levels, carotid atherosclerosis, serum pentosidine, and skin autofluorescence, a recently established noninvasive measure of advanced glycation end products accumulation, was examined in 212 ESRD subjects undergoing hemodialysis. Numbers of circulating EPCs were measured as CD34+ CD133+ CD45(low) VEGFR2+ cells and progenitor cells as CD34+ CD133+ CD45(low) fraction by flow cytometry. Skin autofluorescence was assessed by the autofluorescence reader; and serum pentosidine, by enzyme-linked immunosorbent assay. Carotid atherosclerosis was determined as intimal-medial thickness (IMT) measured by ultrasound. Circulating EPCs were significantly and inversely correlated with skin autofluorescence in ESRD subjects (R = -0.216, P = .002), but not with serum pentosidine (R = -0.079, P = .25). Circulating EPCs tended to be inversely associated with IMT (R = -0.125, P = .069). Intimal-medial thickness was also tended to be correlated positively with skin autofluorescence (R = 0.133, P = .054) and significantly with serum pentosidine (R = 0.159, P = .019). Stepwise multiple regression analyses reveal that skin autofluorescence, but not serum pentosidine and IMT, was independently associated with low circulating EPCs. Of note, skin autofluorescence was also inversely and independently associated with circulating progenitor cells. Thus, tissue accumulated, but not circulating, advanced glycation end products may be a determinant of a decrease in circulating EPCs in ESRD subjects.

  3. Advanced glycation end products, carotid atherosclerosis, and circulating endothelial progenitor cells in patients with end-stage renal disease.

    PubMed

    Ueno, Hiroki; Koyama, Hidenori; Fukumoto, Shinya; Tanaka, Shinji; Shoji, Takuhito; Shoji, Tetsuo; Emoto, Masanori; Tahara, Hideki; Inaba, Masaaki; Kakiya, Ryusuke; Tabata, Tsutomu; Miyata, Toshio; Nishizawa, Yoshiki

    2011-04-01

    Numbers of endothelial progenitor cells (EPCs) have been shown to be decreased in subjects with end-stage renal disease (ESRD), the mechanism of which remained poorly understood. In this study, mutual association among circulating EPC levels, carotid atherosclerosis, serum pentosidine, and skin autofluorescence, a recently established noninvasive measure of advanced glycation end products accumulation, was examined in 212 ESRD subjects undergoing hemodialysis. Numbers of circulating EPCs were measured as CD34+ CD133+ CD45(low) VEGFR2+ cells and progenitor cells as CD34+ CD133+ CD45(low) fraction by flow cytometry. Skin autofluorescence was assessed by the autofluorescence reader; and serum pentosidine, by enzyme-linked immunosorbent assay. Carotid atherosclerosis was determined as intimal-medial thickness (IMT) measured by ultrasound. Circulating EPCs were significantly and inversely correlated with skin autofluorescence in ESRD subjects (R = -0.216, P = .002), but not with serum pentosidine (R = -0.079, P = .25). Circulating EPCs tended to be inversely associated with IMT (R = -0.125, P = .069). Intimal-medial thickness was also tended to be correlated positively with skin autofluorescence (R = 0.133, P = .054) and significantly with serum pentosidine (R = 0.159, P = .019). Stepwise multiple regression analyses reveal that skin autofluorescence, but not serum pentosidine and IMT, was independently associated with low circulating EPCs. Of note, skin autofluorescence was also inversely and independently associated with circulating progenitor cells. Thus, tissue accumulated, but not circulating, advanced glycation end products may be a determinant of a decrease in circulating EPCs in ESRD subjects. PMID:20494372

  4. Carotid artery surgery

    MedlinePlus

    Carotid endarterectomy; CAS surgery; Carotid artery stenosis - surgery; Endarterectomy - carotid artery ... through the catheter around the blocked area during surgery. Your carotid artery is opened. The surgeon removes ...

  5. Predictive haemodynamics in a one-dimensional human carotid artery bifurcation. Part II: Application to graft design.

    PubMed

    Kolachalama, Vijaya B; Bressloff, Neil W; Nair, Prasanth B; Shearman, Clifford P

    2008-03-01

    A Bayesian surrogate modeling technique is proposed that may be able to predict an optimal bypass graft configuration for patients suffering with stenosis in the internal carotid artery (ICA). At the outset, this statistical technique is considered as a means for identifying key geometric parameters influencing haemodynamics in the human carotid bifurcation. This methodology uses a design of experiments (DoE) technique to generate candidate geometries for flow analysis. A pulsatile one dimensional Navier-Stokes solver incorporating fluid-wall interactions for a Newtonian fluid which predicts pressure and flow in the carotid bifurcation (comprising a stenosed segment in the internal carotid artery) is used for the numerical simulations. Two metrics, pressure variation factor (PVF) and maximum pressure (p(*)(m)) are employed to directly compare the global and local effects, respectively, of variations in the geometry. The values of PVF and p(*)(m) are then used to construct two Bayesian surrogate models. These models are statistically analyzed to visualize how each geometric parameter influences PVF and p(*)(m). Percentage of stenosis is found to influence these pressure based metrics more than any other geometric parameter. Later, we identify bypass grafts with optimal geometric and material properties which have low values of PVF on five test cases with 70%, 75%, 80%, 85%, and 90% stenosis in the ICA, respectively.5%, 80%, 85%, and 90% stenosis in the ICA, respectively. PMID:18334411

  6. Advances in human genetics

    SciTech Connect

    Harris, H.; Hirschhorn, K.

    1993-01-01

    This book has five chapters covering peroxisomal diseases, X-linked immunodeficiencies, genetic mutations affecting human lipoproteins and their receptors and enzymes, genetic aspects of cancer, and Gaucher disease. The chapter on peroxisomes covers their discovery, structure, functions, disorders, etc. The chapter on X-linked immunodeficiencies discusses such diseases as agammaglobulinemia, severe combined immunodeficiency, Wiskott-Aldrich syndrome, animal models, linkage analysis, etc. Apolipoprotein formation, synthesis, gene regulation, proteins, etc. are the main focus of chapter 3. The chapter on cancer covers such topics as oncogene mapping and the molecular characterization of some recessive oncogenes. Gaucher disease is covered from its diagnosis, classification, and prevention, to its organ system involvement and molecular biology.

  7. Bilateral carotid artery injury response in side impact using a vessel model integrated with a human body model.

    PubMed

    Danelson, Kerry A; Gayzik, F Scott; Yu, Mao M; Martin, R Shayn; Duma, Stefan M; Stitzel, Joel D

    2009-10-01

    In a far-side crash configuration, the occupant can experience severe excursion from the seat space. Given this challenge, there are research efforts focused on alternate restraints, such as four-point belts. A potential implication of this geometry would be interaction of the belt with the occupant's neck. This study examines the response of the carotid arteries using a Finite Element Model (FEM) in a far-side crash configuration with a reversed three-point restraint. A FEM of the carotid artery and neck fascia was developed and integrated with the Total Human Model for Safety (THUMS) version 1.44. This model was subjected to four test conditions simulating far-side crashes. Load conditions included a low velocity impact of approximately 4 m/s and a higher velocity impact of approximately 10 m/s. For each velocity, the model was restrained with a belt placed low on the neck and a belt placed higher on the neck. Strain data in each element of the carotid arteries was analyzed. The overall response of the vessel was examined to determine locations of high strain values. Low belt placement resulted in more head excursion, stretching the carotid on the non-struck side. High belt placement resulted in compression of the artery on the struck side due to direct loading of the vessel from the belt. Strain values in the carotid artery elements increased with increasing speed of impact. The lower and higher speed tests with a low belt configuration resulted in a maximum principal strains, at maximal belt engagement, of 0.223 and 0.459, respectively. Corresponding values for the high belt configuration were 0.222 and 0.563. In both belt configurations, the non-struck side vessel stretched more than the struck side vessel; however, the non-struck side vessel experienced higher compressive forces. Strain values measured during the simulations can be compared to a value of 0.31 to intimal failure in previous experimental tests. These results quantitatively illustrate the two

  8. Bilateral Carotid Artery Injury Response in Side Impact Using a Vessel Model Integrated with a Human Body Model

    PubMed Central

    Danelson, Kerry A.; Gayzik, F. Scott; Yu, Mao M.; Martin, R. Shayn; Duma, Stefan M.; Stitzel, Joel D.

    2009-01-01

    In a far-side crash configuration, the occupant can experience severe excursion from the seat space. Given this challenge, there are research efforts focused on alternate restraints, such as four-point belts. A potential implication of this geometry would be interaction of the belt with the occupant’s neck. This study examines the response of the carotid arteries using a Finite Element Model (FEM) in a far-side crash configuration with a reversed three-point restraint. A FEM of the carotid artery and neck fascia was developed and integrated with the Total Human Model for Safety (THUMS) version 1.44. This model was subjected to four test conditions simulating far-side crashes. Load conditions included a low velocity impact of approximately 4 m/s and a higher velocity impact of approximately 10 m/s. For each velocity, the model was restrained with a belt placed low on the neck and a belt placed higher on the neck. Strain data in each element of the carotid arteries was analyzed. The overall response of the vessel was examined to determine locations of high strain values. Low belt placement resulted in more head excursion, stretching the carotid on the non-struck side. High belt placement resulted in compression of the artery on the struck side due to direct loading of the vessel from the belt. Strain values in the carotid artery elements increased with increasing speed of impact. The lower and higher speed tests with a low belt configuration resulted in a maximum principal strains, at maximal belt engagement, of 0.223 and 0.459, respectively. Corresponding values for the high belt configuration were 0.222 and 0.563. In both belt configurations, the non-struck side vessel stretched more than the struck side vessel; however, the non-struck side vessel experienced higher compressive forces. Strain values measured during the simulations can be compared to a value of 0.31 to intimal failure in previous experimental tests. These results quantitatively illustrate the two

  9. Morphometric and hemodynamic analysis of atherosclerotic progression in human carotid artery bifurcations.

    PubMed

    Huang, Xu; Yin, Xiaoping; Xu, Yingjin; Jia, Xinwei; Li, Jianhui; Niu, Pei; Shen, Wenzeng; Kassab, Ghassan S; Tan, Wenchang; Huo, Yunlong

    2016-03-01

    Although atherosclerosis has been widely investigated at carotid artery bifurcation, there is a lack of morphometric and hemodynamic data at different stages of the disease. The purpose of this study was to determine the lesion difference in patients with carotid artery disease compared with healthy control subjects. The three-dimensional (3D) geometry of carotid artery bifurcation was reconstructed from computed tomography angiography (CTA) images of Chinese control subjects (n = 30) and patients with carotid artery disease (n = 30). We defined two novel vector angles (i.e., angles 1 and 2) that were tangential to the reconstructed contour of the 3D vessel. The best-fit diameter was computed along the internal carotid artery (ICA) center line. Hemodynamic analysis was performed at various bifurcations. Patients with stenotic vessels have larger angles 1 and 2 (151 ± 11° and 42 ± 20°) and smaller diameters of the external carotid artery (ECA) (4.6 ± 0.85 mm) compared with control subjects (144 ± 13° and 36 ± 16°, 5.2 ± 0.57 mm) although there is no significant difference in the common carotid artery (CCA) (7.1 ± 1.2 vs. 7.5 ± 1.0 mm, P = 0.18). In particular, all patients with carotid artery disease have a stenosis at the proximal ICA (including both sinus and carina regions), while 20% of patients have stenosis at the middle ICA and 20% have stenosis expansion to the entire cervical ICA. Morphometric and hemodynamic analyses suggest that atherosclerotic plaques initiate at both sinus and carina regions of ICA and progress downstream.

  10. Effects of exercise pressor reflex activation on carotid baroreflex function during exercise in humans

    NASA Technical Reports Server (NTRS)

    Gallagher, K. M.; Fadel, P. J.; Stromstad, M.; Ide, K.; Smith, S. A.; Querry, R. G.; Raven, P. B.; Secher, N. H.

    2001-01-01

    1. This investigation was designed to determine the contribution of the exercise pressor reflex to the resetting of the carotid baroreflex during exercise. 2. Ten subjects performed 3.5 min of static one-legged exercise (20 % maximal voluntary contraction) and 7 min dynamic cycling (20 % maximal oxygen uptake) under two conditions: control (no intervention) and with the application of medical anti-shock (MAS) trousers inflated to 100 mmHg (to activate the exercise pressor reflex). Carotid baroreflex function was determined at rest and during exercise using a rapid neck pressure/neck suction technique. 3. During exercise, the application of MAS trousers (MAS condition) increased mean arterial pressure (MAP), plasma noradrenaline concentration (dynamic exercise only) and perceived exertion (dynamic exercise only) when compared to control (P < 0.05). No effect of the MAS condition was evident at rest. The MAS condition had no effect on heart rate (HR), plasma lactate and adrenaline concentrations or oxygen uptake at rest and during exercise. The carotid baroreflex stimulus-response curve was reset upward on the response arm and rightward to a higher operating pressure by control exercise without alterations in gain. Activation of the exercise pressor reflex by MAS trousers further reset carotid baroreflex control of MAP, as indicated by the upward and rightward relocation of the curve. However, carotid baroreflex control of HR was only shifted rightward to higher operating pressures by MAS trousers. The sensitivity of the carotid baroreflex was unaltered by exercise pressor reflex activation. 4. These findings suggest that during dynamic and static exercise the exercise pressor reflex is capable of actively resetting carotid baroreflex control of mean arterial pressure; however, it would appear only to modulate carotid baroreflex control of heart rate.

  11. Distinctive proteomic profiles among different regions of human carotid plaques in men and women

    PubMed Central

    Liang, Wenzhao; Ward, Liam J.; Karlsson, Helen; Ljunggren, Stefan A.; Li, Wei; Lindahl, Mats; Yuan, Xi-Ming

    2016-01-01

    The heterogeneity of atherosclerotic tissue has limited comprehension in proteomic and metabolomic analyses. To elucidate the functional implications, and differences between genders, of atherosclerotic lesion formation we investigated protein profiles from different regions of human carotid atherosclerotic arteries; internal control, fatty streak, plaque shoulder, plaque centre, and fibrous cap. Proteomic analysis was performed using 2-DE with MALDI-TOF, with validation using nLC-MS/MS. Protein mapping of 2-DE identified 52 unique proteins, including 15 previously unmapped proteins, of which 41 proteins were confirmed by nLC-MS/MS analysis. Expression levels of 18 proteins were significantly altered in plaque regions compared to the internal control region. Nine proteins showed site-specific alterations, irrespective of gender, with clear associations to extracellular matrix remodelling. Five proteins display gender-specific alterations with 2-DE, with two alterations validated by nLC-MS/MS. Gender differences in ferritin light chain and transthyretin were validated using both techniques. Validation of immunohistochemistry confirmed significantly higher levels of ferritin in plaques from male patients. Proteomic analysis of different plaque regions has reduced the effects of plaque heterogeneity, and significant differences in protein expression are determined in specific regions and between genders. These proteomes have functional implications in plaque progression and are of importance in understanding gender differences in atherosclerosis. PMID:27198765

  12. Aspirin augments carotid-cardiac baroreflex sensitivity during muscle mechanoreflex and metaboreflex activation in humans.

    PubMed

    Drew, Rachel C; Muller, Matthew D; Blaha, Cheryl A; Mast, Jessica L; Herr, Michael D; Stocker, Sean D; Sinoway, Lawrence I

    2013-10-15

    Muscle mechanoreflex activation decreases the sensitivity of carotid baroreflex (CBR)-heart rate (HR) control during local metabolite accumulation in humans. However, the contribution of thromboxane A2 (TXA2) toward this response is unknown. Therefore, the effect of inhibiting TXA2 production via low-dose aspirin on CBR-HR sensitivity during muscle mechanoreflex and metaboreflex activation in humans was examined. Twelve young subjects performed two trials during two visits, preceded by 7 days' low-dose aspirin (81 mg) or placebo. One trial involved 3-min passive calf stretch (mechanoreflex) during 7.5-min limb circulatory occlusion (CO). In another trial, CO was preceded by 1.5 min of 70% maximal voluntary contraction isometric calf exercise to accumulate metabolites during CO and stretch (mechanoreflex and metaboreflex). HR (ECG) and mean arterial pressure (Finometer) were recorded. CBR function was assessed using rapid neck pressures ranging from +40 to -80 mmHg. Aspirin significantly decreased baseline thromboxane B2 production by 84 ± 4% (P < 0.05) but did not affect 6-keto prostaglandin F1α. Following aspirin, stretch with metabolite accumulation significantly augmented maximal gain (GMAX) and operating point gain (GOP) of CBR-HR (GMAX; -0.71 ± 0.14 vs. -0.37 ± 0.08 and GOP; -0.69 ± 0.13 vs. -0.35 ± 0.12 beats·min(-1)·mmHg(-1) for aspirin and placebo, respectively; P < 0.05). CBR-HR function curves were reset similarly with aspirin and placebo during stretch with metabolite accumulation. In conclusion, these findings suggest that low-dose aspirin augments CBR-HR sensitivity during concurrent muscle mechanoreflex and metaboreflex activation in humans. This increased sensitivity appears linked to reduced TXA2 production, which likely plays a role in metabolite sensitization of muscle mechanoreceptors. PMID:23970529

  13. Carotid Ultrasound

    MedlinePlus

    ... plaque narrows the carotid arteries and reduces the flow of oxygen-rich blood to the brain. If the plaque ruptures, a blood clot can form on its surface. A clot can mostly or completely block blood flow through a carotid artery, which can cause a ...

  14. Differential mechanical response and microstructural organization between non-human primate femoral and carotid arteries

    PubMed Central

    Raykin, Julia; Li, Haiyan; Gleason, Rudolph L.

    2014-01-01

    Unique anatomic locations and physiologic functions predispose different arteries to varying mechanical responses and pathologies. However, the underlying causes of these mechanical differences are not well understood. The objective of this study was to first identify structural differences in the arterial matrix that would account for the mechanical differences between healthy femoral and carotid arteries and second to utilize these structural observations to perform a microstructurally motivated constitutive analysis. Femoral and carotid arteries were subjected to cylindrical biaxial loading and their microstructure was quantified using two-photon microscopy. The femoral arteries were found to be less compliant than the carotid arteries at physiologic loads, consistent with previous studies, despite similar extracellular compositions of collagen and elastin (P > 0.05). The femoral arteries exhibited significantly less circumferential dispersion of collagen fibers (P < 0.05), despite a similar mean fiber alignment direction as the carotid arteries. Elastin transmural distribution, in vivo axial stretch, and opening angles were also found to be distinctly different between the arteries. Lastly, we modeled the arteries’ mechanical behaviors using a microstructural-based, distributed collagen fiber constitutive model. With this approach, the material parameters of the model were solved using the experimental microstructural observations. The findings of this study support an important role for microstructural organization in arterial stiffness. PMID:24532266

  15. Sympathoinhibition and hypotension in carotid sinus hypersensitivity

    NASA Technical Reports Server (NTRS)

    Smith, M. L.; Ellenbogen, K. A.; Eckberg, D. L.

    1992-01-01

    Carotid sinus reflex hypersensitivity is a known cause of syncope in humans. The condition is characterized by cardioinhibition and vasodepression, each to varying degrees. The extent and importance of sympathoinhibition has not been determined in patients with carotid sinus hypersensitivity. This study reports on the extent of sympathoinhibition measured directly directly during carotid massage with and without atrioventricular sequential pacing, in a patient with symptomatic carotid sinus reflex hypersensitivity. Carotid massage elicited asystole, hypotension and complete inhibition of muscle sympathetic nerve activity. Carotid massage during atrioventricular pacing produced similar sympathoinhibition, but with minimal hypotension. Therefore, sympathoinhibition did not contribute importantly to the hypotension during carotid massage in the supine position in this patient. Further investigations are required to elucidate the relation of sympathoinhibition to hypotension in patients with carotid sinus hypersensitivity in the upright position.

  16. Role of central command in carotid baroreflex resetting in humans during static exercise

    NASA Technical Reports Server (NTRS)

    Ogoh, S.; Wasmund, W. L.; Keller, D. M.; O-Yurvati, A.; Gallagher, K. M.; Mitchell, J. H.; Raven, P. B.

    2002-01-01

    The purpose of the experiments was to examine the role of central command in the exercise-induced resetting of the carotid baroreflex. Eight subjects performed 30 % maximal voluntary contraction (MVC) static knee extension and flexion with manipulation of central command (CC) by patellar tendon vibration (PTV). The same subjects also performed static knee extension and flexion exercise without PTV at a force development that elicited the same ratings of perceived exertion (RPE) as those observed during exercise with PTV in order to assess involvement of the exercise pressor reflex. Carotid baroreflex (CBR) function curves were modelled from the heart rate (HR) and mean arterial pressure (MAP) responses to rapid changes in neck pressure and suction during steady state static exercise. Knee extension exercise with PTV (decreased CC activation) reset the CBR-HR and CBR-MAP to a lower operating pressure (P < 0.05) and knee flexion exercise with PTV (increased CC activation) reset the CBR-HR and CBR-MAP to a higher operating pressure (P < 0.05). Comparison between knee extension and flexion exercise at the same RPE with and without PTV found no difference in the resetting of the CBR-HR function curves (P > 0.05) suggesting the response was determined primarily by CC activation. However, the CBR-MAP function curves were reset to operating pressures determined by both exercise pressor reflex (EPR) and central command activation. Thus the physiological response to exercise requires CC activation to reset the carotid-cardiac reflex but requires either CC or EPR to reset the carotid-vasomotor reflex.

  17. Multi-analyte profiling in human carotid atherosclerosis uncovers pro-inflammatory macrophage programming in plaques.

    PubMed

    Shalhoub, Joseph; Viiri, Leena E; Cross, Amanda J; Gregan, Scott M; Allin, David M; Astola, Nagore; Franklin, Ian J; Davies, Alun H; Monaco, Claudia

    2016-05-01

    Molecular characterisation of vulnerable atherosclerosis is necessary for targeting functional imaging and plaque-stabilising therapeutics. Inflammation has been linked to atherogenesis and the development of high-risk plaques. We set to quantify cytokine, chemokine and matrix metalloproteinase (MMP) protein production in cells derived from carotid plaques to map the inflammatory milieu responsible for instability. Carotid endarterectomies from carefully characterised symptomatic (n=35) and asymptomatic (n=32) patients were enzymatically dissociated producing mixed cell type atheroma cell suspensions which were cultured for 24 hours. Supernatants were interrogated for 45 analytes using the Luminex 100 platform. Twenty-nine of the 45 analytes were reproducibly detectable in the majority of donors. The in vitro production of a specific network of mediators was found to be significantly higher in symptomatic than asymptomatic plaques, including: tumour necrosis factor α, interleukin (IL) 1β, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), CCL5, CCL20, CXCL9, matrix metalloproteinase (MMP)-3 and MMP-9. Ingenuity pathway analysis of differentially expressed analytes between symptomatic and asymptomatic patients identified a number of key biological pathways (p< 10(-25)). In conclusion, the carotid artery plaque culprit of ischaemic neurological symptoms is characterised by an inflammatory milieu favouring inflammatory cell recruitment and pro-inflammatory macrophage polarisation. PMID:26763091

  18. Multi-analyte profiling in human carotid atherosclerosis uncovers pro-inflammatory macrophage programming in plaques.

    PubMed

    Shalhoub, Joseph; Viiri, Leena E; Cross, Amanda J; Gregan, Scott M; Allin, David M; Astola, Nagore; Franklin, Ian J; Davies, Alun H; Monaco, Claudia

    2016-05-01

    Molecular characterisation of vulnerable atherosclerosis is necessary for targeting functional imaging and plaque-stabilising therapeutics. Inflammation has been linked to atherogenesis and the development of high-risk plaques. We set to quantify cytokine, chemokine and matrix metalloproteinase (MMP) protein production in cells derived from carotid plaques to map the inflammatory milieu responsible for instability. Carotid endarterectomies from carefully characterised symptomatic (n=35) and asymptomatic (n=32) patients were enzymatically dissociated producing mixed cell type atheroma cell suspensions which were cultured for 24 hours. Supernatants were interrogated for 45 analytes using the Luminex 100 platform. Twenty-nine of the 45 analytes were reproducibly detectable in the majority of donors. The in vitro production of a specific network of mediators was found to be significantly higher in symptomatic than asymptomatic plaques, including: tumour necrosis factor α, interleukin (IL) 1β, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage colony-stimulating factor (M-CSF), CCL5, CCL20, CXCL9, matrix metalloproteinase (MMP)-3 and MMP-9. Ingenuity pathway analysis of differentially expressed analytes between symptomatic and asymptomatic patients identified a number of key biological pathways (p< 10(-25)). In conclusion, the carotid artery plaque culprit of ischaemic neurological symptoms is characterised by an inflammatory milieu favouring inflammatory cell recruitment and pro-inflammatory macrophage polarisation.

  19. Comparison of grey scale median (GSM) measurement in ultrasound images of human carotid plaques using two different softwares.

    PubMed

    Östling, Gerd; Persson, Margaretha; Hedblad, Bo; Gonçalves, Isabel

    2013-11-01

    Grey scale median (GSM) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut-off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with Adobe Photoshop(®) and with Artery Measurement System (AMS) on duplex ultrasound images of 100 consecutive medium- to large-sized carotid plaques of the Beta-blocker Cholesterol-lowering Asymptomatic Plaque Study (BCAPS). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for Adobe Photoshop(®) and AMS, respectively. Mean difference was 20·45 (95% CI: 19·17-21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi-square test revealed a kappa value of 0·68 when studying quartiles of GSM. The intra-observer variability was 1·9% for AMS and 2·5% for Adobe Photoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries.

  20. Fractal analysis of the structural complexity of the connective tissue in human carotid bodies

    PubMed Central

    Guidolin, Diego; Porzionato, Andrea; Tortorella, Cinzia; Macchi, Veronica; De Caro, Raffaele

    2014-01-01

    The carotid body (CB) may undergo different structural changes during perinatal development, aging, or in response to environmental stimuli. In the previous literature, morphometric approaches to evaluate these changes have considered quantitative first order parameters, such as volumes or densities, while changes in spatial disposition and/or complexity of structural components have not yet been considered. In the present study, different strategies for addressing morphological complexity of CB, apart from the overall amount of each tissue component, were evaluated and compared. In particular, we considered the spatial distribution of connective tissue in the carotid bodies of young control subjects, young opiate-related deaths and aged subjects, through analysis of dispersion (Morisita's index), gray level co-occurrence matrix (entropy, angular second moment, variance, correlation), and fractal analysis (fractal dimension, lacunarity). Opiate-related deaths and aged subjects showed a comparable increase in connective tissue with respect to young controls. However, the Morisita's index (p < 0.05), angular second moment (p < 0.05), fractal dimension (p < 0.01), and lacunarity (p < 0.01) permitted to identify significant differences in the disposition of the connective tissue between these two series. A receiver operating characteristic (ROC) curve was also calculated to evaluate the efficiency of each parameter. The fractal dimension and lacunarity, with areas under the ROC curve of 0.9651 (excellent accuracy) and 0.8835 (good accuracy), respectively, showed the highest discriminatory power. They evidenced higher level of structural complexity in the carotid bodies of opiate-related deaths than old controls, due to more complex branching of intralobular connective tissue. Further analyses will have to consider the suitability of these approaches to address other morphological features of the CB, such as different cell populations, vascularization, and innervation

  1. Carotid barochemoreceptor pathological findings regarding carotid plaque status and aging

    PubMed Central

    Milei, José; Lavezzi, Anna M; Bruni, Barbara; Grana, Daniel R; Azzato, Francisco; Matturri, Luigi

    2009-01-01

    BACKGROUND: Carotid barochemoreceptor pathological lesions have been studied in animals, but few human necropsies have been performed. Therefore, data rely on case patients following surgery, radiotherapy and carotid endarterectomy. Almost no data are available regarding whether the effect of aging prevails over pathological conditions, despite the classic description that glomic fibrosis increases with age. OBJECTIVE: To morphometrically characterize the alterations of the carotid barochemoreceptors and their supplying arteries. METHODS: Patients (n=23) who had suffered and died from stroke, with and without complicated internal carotid atheromatosis, were divided by age (group 1: older than 80 years; group 2: 65 to 80 years; and group 3: younger than 65 years). Carotid segments were obtained at autopsy. The specimens were stained for light microscopy and immunohistochemistry. RESULTS: Carotid glomus presented from moderate-to-severe atrophy and fibrosis. A focal decrease in vascularization (CD34-positive) of the glomus (greater than 50%) was observed in areas of atrophy and fibrosis. Damaged nerve endings (S100 protein-positive) were observed at the media of the carotid sinus. Morphometric data showed no differences between groups for glomus area, number of type 1 and 2 cells, and the wall to lumen arteriole ratio. No statistical differences were demonstrated in the pathological findings of the carotid glomus when comparing complicated with noncomplicated plaques or age groups. CONCLUSION: Severe carotid chemoreceptor damage exists in patients who have died from stroke and suffered from carotid atheromatosis. These findings were independent from aging and plaque type. However, damage was correlated with a marked narrowing of the supplying arterioles as a consequence of hemodynamic and/or metabolic alterations (dyslipidemia, diabetes). PMID:19148350

  2. Healthy older humans exhibit augmented carotid-cardiac baroreflex sensitivity with aspirin during muscle mechanoreflex and metaboreflex activation.

    PubMed

    Drew, Rachel C; Blaha, Cheryl A; Herr, Michael D; Stocker, Sean D; Sinoway, Lawrence I

    2015-10-01

    Low-dose aspirin inhibits thromboxane production and augments the sensitivity of carotid baroreflex (CBR) control of heart rate (HR) during concurrent muscle mechanoreflex and metaboreflex activation in healthy young humans. However, it is unknown how aging affects this response. Therefore, the effect of low-dose aspirin on carotid-cardiac baroreflex sensitivity during muscle mechanoreflex with and without metaboreflex activation in healthy older humans was examined. Twelve older subjects (6 men and 6 women, mean age: 62 ± 1 yr) performed two trials during two visits preceded by 7 days of low-dose aspirin (81 mg) or placebo. One trial involved 3 min of passive calf stretch (mechanoreflex) during 7.5 min of limb circulatory occlusion (CO). In another trial, CO was preceded by 1.5 min of 70% maximal voluntary contraction isometric calf exercise (mechanoreflex and metaboreflex). HR (ECG) and mean arterial blood pressure (MAP; Finometer) were recorded. CBR function was assessed using rapid neck pressure application (+40 to -80 mmHg). Aspirin significantly decreased baseline thromboxane B2 production by 83 ± 4% (P < 0.05) but did not affect 6-keto-PGF1α. After aspirin, CBR-HR maximal gain and operating point gain were significantly higher during stretch with metabolite accumulation compared with placebo (maximal gain: -0.23 ± 0.03 vs. -0.14 ± 0.02 and operating point gain: -0.11 ± 0.03 vs. -0.04 ± 0.01 beats·min(-1)·mmHg(-1) for aspirin and placebo, respectively, P < 0.05). In conclusion, these findings suggest that low-dose aspirin augments CBR-HR sensitivity during concurrent muscle mechanoreflex and metaboreflex activation in healthy older humans. This increased sensitivity appears linked to reduced thromboxane sensitization of muscle mechanoreceptors, which consequently improves CBR-HR control. PMID:26371168

  3. Healthy older humans exhibit augmented carotid-cardiac baroreflex sensitivity with aspirin during muscle mechanoreflex and metaboreflex activation.

    PubMed

    Drew, Rachel C; Blaha, Cheryl A; Herr, Michael D; Stocker, Sean D; Sinoway, Lawrence I

    2015-10-01

    Low-dose aspirin inhibits thromboxane production and augments the sensitivity of carotid baroreflex (CBR) control of heart rate (HR) during concurrent muscle mechanoreflex and metaboreflex activation in healthy young humans. However, it is unknown how aging affects this response. Therefore, the effect of low-dose aspirin on carotid-cardiac baroreflex sensitivity during muscle mechanoreflex with and without metaboreflex activation in healthy older humans was examined. Twelve older subjects (6 men and 6 women, mean age: 62 ± 1 yr) performed two trials during two visits preceded by 7 days of low-dose aspirin (81 mg) or placebo. One trial involved 3 min of passive calf stretch (mechanoreflex) during 7.5 min of limb circulatory occlusion (CO). In another trial, CO was preceded by 1.5 min of 70% maximal voluntary contraction isometric calf exercise (mechanoreflex and metaboreflex). HR (ECG) and mean arterial blood pressure (MAP; Finometer) were recorded. CBR function was assessed using rapid neck pressure application (+40 to -80 mmHg). Aspirin significantly decreased baseline thromboxane B2 production by 83 ± 4% (P < 0.05) but did not affect 6-keto-PGF1α. After aspirin, CBR-HR maximal gain and operating point gain were significantly higher during stretch with metabolite accumulation compared with placebo (maximal gain: -0.23 ± 0.03 vs. -0.14 ± 0.02 and operating point gain: -0.11 ± 0.03 vs. -0.04 ± 0.01 beats·min(-1)·mmHg(-1) for aspirin and placebo, respectively, P < 0.05). In conclusion, these findings suggest that low-dose aspirin augments CBR-HR sensitivity during concurrent muscle mechanoreflex and metaboreflex activation in healthy older humans. This increased sensitivity appears linked to reduced thromboxane sensitization of muscle mechanoreceptors, which consequently improves CBR-HR control.

  4. Attenuation of human carotid-cardiac vagal baroreflex responses after physical detraining

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.; Fritsch, Janice M.

    1992-01-01

    Astronauts who are occupied with prelaunch schedules may have to limit their regular physical exercise routines. To assess a potential effect on blood pressure control, carotid baroreceptor-cardiac reflex responses of 16 men were evaluated before and after two weeks of exercise detraining that followed ten weeks of regular scheduled exercise (30 min/d, 4 d/week at 75 percent V(O2) max). After detraining, the baroreflex stimulus-response relationship had a reduced slope 0.4 msec/mmHg and range of response. In addition, there was a resetting of the relationship on the R-R interval axis. Both the minimum and maximum R-R interval responses to the stimulus were significantly reduced after detraining. Baseline systolic pressure did not change with detraining, and the carotid baroreceptor-cardiac response relationship did not shift on the pressure axis. These results suggest that detraining from regular exercise can compromise vagally-mediated mechanisms of blood pressure regulation.

  5. Short-duration spaceflight impairs human carotid baroreceptor-cardiac reflex responses.

    PubMed

    Fritsch, J M; Charles, J B; Bennett, B S; Jones, M M; Eckberg, D L

    1992-08-01

    Orthostatic intolerance is a predictable but poorly understood consequence of space travel. Because arterial baroreceptors modulate abrupt pressure transients, we tested the hypothesis that spaceflight impairs baroreflex mechanisms. We studied vagally mediated carotid baroreceptor-cardiac reflex responses (provoked by neck pressure changes) in the supine position and heart rate and blood pressure in the supine and standing positions in 16 astronauts before and after 4- to 5-day Space Shuttle missions. On landing day, resting R-R intervals and standard deviations, and the slope, range, and position of operational points on the carotid transmural pressure-sinus node response relation were all reduced relative to preflight. Stand tests on landing day revealed two separate groups (one maintained standing arterial pressure better) that were separated by preflight slopes, operational points, and supine and standing R-R intervals and by preflight-to-postflight changes in standing pressures, body weights, and operational points. Our results suggest that short-duration spaceflight leads to significant reductions in vagal control of the sinus node that may contribute to, but do not account completely for, orthostatic intolerance.

  6. Plaque components affect wall stress in stented human carotid artery: A numerical study

    NASA Astrophysics Data System (ADS)

    Fan, Zhen-Min; Liu, Xiao; Du, Cheng-Fei; Sun, An-Qiang; Zhang, Nan; Fan, Zhan-Ming; Fan, Yu-Bo; Deng, Xiao-Yan

    2016-09-01

    Carotid artery stenting presents challenges of in-stent restenosis and late thrombosis, which are caused primarily by alterations in the mechanical environment of the artery after stent implantation. The present study constructed patient-specific carotid arterial bifurcation models with lipid pools and calcified components based on magnetic resonance imaging. We numerically analyzed the effects of multicomponent plaques on the distributions of von Mises stresses (VMSs) in the patient-specific models after stenting. The results showed that when a stent was deployed, the large soft lipid pool in atherosclerotic plaques cushioned the host artery and reduced the stress within the arterial wall; however, this resulted in a sharp increase of VMS in the fibrous cap. When compared with the lipid pool, the presence of the calcified components led to slightly increased stresses on the luminal surface. However, when a calcification was located close to the luminal surface of the host artery and the stenosis, the local VMS was elevated. Overall, compared with calcified components, large lipid pools severely damaged the host artery after stenting. Furthermore, damage due to the calcified component may depend on location.

  7. Propionibacterium acnes Recovered from Atherosclerotic Human Carotid Arteries Undergoes Biofilm Dispersion and Releases Lipolytic and Proteolytic Enzymes in Response to Norepinephrine Challenge In Vitro

    PubMed Central

    Lanter, Bernard B.

    2015-01-01

    In the present study, human atherosclerotic carotid arteries were examined following endarterectomy for the presence of the Gram-positive bacterium Propionibacterium acnes and its potential association with biofilm structures within the arterial wall. The P. acnes 16S rRNA gene was detectable in 4 of 15 carotid artery samples, and viable P. acnes was one among 10 different bacterial species recoverable in culture. Fluorescence in situ hybridization analysis of 5 additional atherosclerotic carotid arteries demonstrated biofilm bacteria within all samples, with P. acnes detectable in 4 samples. We also demonstrated that laboratory-grown cultures of P. acnes biofilms were susceptible to induction of a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of iron-bound transferrin or with free iron. The production and release of lipolytic and proteolytic extracellular enzymes by P. acnes were shown to increase in iron-induced dispersed biofilms, and these dispersion-induced P. acnes VP1 biofilms showed increased expression of mRNAs for the triacylglycerol lipases PPA2105 and PPA1796 and the hyaluronate lyase PPA380 compared to that in untreated biofilms. These results demonstrate that P. acnes can infect the carotid arteries of humans with atherosclerosis as a component of multispecies biofilms and that dispersion is inducible for this organism, at least in vitro, with physiologically relevant levels of norepinephrine resulting in the production and release of degradative enzymes. PMID:26216428

  8. Propionibacterium acnes Recovered from Atherosclerotic Human Carotid Arteries Undergoes Biofilm Dispersion and Releases Lipolytic and Proteolytic Enzymes in Response to Norepinephrine Challenge In Vitro.

    PubMed

    Lanter, Bernard B; Davies, David G

    2015-10-01

    In the present study, human atherosclerotic carotid arteries were examined following endarterectomy for the presence of the Gram-positive bacterium Propionibacterium acnes and its potential association with biofilm structures within the arterial wall. The P. acnes 16S rRNA gene was detectable in 4 of 15 carotid artery samples, and viable P. acnes was one among 10 different bacterial species recoverable in culture. Fluorescence in situ hybridization analysis of 5 additional atherosclerotic carotid arteries demonstrated biofilm bacteria within all samples, with P. acnes detectable in 4 samples. We also demonstrated that laboratory-grown cultures of P. acnes biofilms were susceptible to induction of a biofilm dispersion response when challenged with physiologically relevant levels of norepinephrine in the presence of iron-bound transferrin or with free iron. The production and release of lipolytic and proteolytic extracellular enzymes by P. acnes were shown to increase in iron-induced dispersed biofilms, and these dispersion-induced P. acnes VP1 biofilms showed increased expression of mRNAs for the triacylglycerol lipases PPA2105 and PPA1796 and the hyaluronate lyase PPA380 compared to that in untreated biofilms. These results demonstrate that P. acnes can infect the carotid arteries of humans with atherosclerosis as a component of multispecies biofilms and that dispersion is inducible for this organism, at least in vitro, with physiologically relevant levels of norepinephrine resulting in the production and release of degradative enzymes. PMID:26216428

  9. Endothelial shear stress estimation in the human carotid artery based on Womersley versus Poiseuille flow.

    PubMed

    Schwarz, Janina C V; Duivenvoorden, Raphaël; Nederveen, Aart J; Stroes, Erik S G; VanBavel, Ed

    2015-03-01

    Endothelial shear stress (ESS) dynamics are a major determinant of atherosclerosis development. The frequently used Poiseuille method to estimate ESS dynamics has important limitations. Therefore, we investigated whether Womersley flow may provide a better alternative for estimation of ESS while requiring equally simple hemodynamic parameters. Common carotid blood flow, centerline velocity, lumen diameter and mean wall thickness (MWT) were measured with 3T-MRI in 45 subjects at three different occasions. Mean ESS and two measures of pulsatility [shear pulsatility index (SPI) and oscillatory shear index (OSI)] were estimated based on Poiseuille and Womersley flow and compared to the more complex velocity gradient modelling method. The association between ESS and MWT was tested with multiple linear regression analysis; interscan reproducibility was assessed using intraclass correlation coefficients (ICC). Mean ESS and pulsatility indices based on Womersley flow (ESSwq β = -0.18, P = 0.04; SPIwq β = 0.24, P = 0.02; OSIwq β = 0.18, P = 0.045), showed equally good correlations with carotid MWT as the velocity gradient method (ESSvg β = -0.23, P = 0.01; SPIvg β = 0.21, P = 0.02; OSIvg β = 0.07, P = 0.47). This in contrast to the Poiseuille flow method that only showed a good correlation for mean ESS (ESSpq β = -0.18, P = 0.04; SPIpq β = 0.14, P = 0.14; OSIpq β = 0.04, P = 0.69). Womersley and Poiseuille methods had high intraclass correlation coefficients indicating good interscan reproducibility (both ICC = 0.84, 95% confidence interval 0.75-0.90). Estimation of ESS dynamics based on Womersley flow modelling is superior to Poiseuille flow modelling and has good interscan reproducibility.

  10. Carotid baroreflex regulation of sympathetic nerve activity during dynamic exercise in humans

    NASA Technical Reports Server (NTRS)

    Fadel, P. J.; Ogoh, S.; Watenpaugh, D. E.; Wasmund, W.; Olivencia-Yurvati, A.; Smith, M. L.; Raven, P. B.

    2001-01-01

    We sought to determine whether carotid baroreflex (CBR) control of muscle sympathetic nerve activity (MSNA) was altered during dynamic exercise. In five men and three women, 23.8 +/- 0.7 (SE) yr of age, CBR function was evaluated at rest and during 20 min of arm cycling at 50% peak O(2) uptake using 5-s periods of neck pressure and neck suction. From rest to steady-state arm cycling, mean arterial pressure (MAP) was significantly increased from 90.0 +/- 2.7 to 118.7 +/- 3.6 mmHg and MSNA burst frequency (microneurography at the peroneal nerve) was elevated by 51 +/- 14% (P < 0.01). However, despite the marked increases in MAP and MSNA during exercise, CBR-Delta%MSNA responses elicited by the application of various levels of neck pressure and neck suction ranging from +45 to -80 Torr were not significantly different from those at rest. Furthermore, estimated baroreflex sensitivity for the control of MSNA at rest was the same as during exercise (P = 0.74) across the range of neck chamber pressures. Thus CBR control of sympathetic nerve activity appears to be preserved during moderate-intensity dynamic exercise.

  11. Choice of In Vivo Versus Idealized Velocity Boundary Conditions Influences Physiologically Relevant Flow Patterns in a Subject-Specific Simulation of Flow in the Human Carotid Bifurcation

    PubMed Central

    Wake, Amanda K.; Oshinski, John N.; Tannenbaum, Allen R.; Giddens, Don P.

    2009-01-01

    Background Accurate fluid mechanics models are important tools for predicting the flow field in the carotid artery bifurcation and for understanding the relationship between hemodynamics and the initiation and progression of atherosclerosis. Clinical imaging modalities can be used to obtain geometry and blood flow data for developing subject-specific, human carotid artery bifurcation models. Method of Approach We developed subject-specific computational fluid dynamics (CFD) models of the human carotid bifurcation from magnetic resonance (MR) geometry data and phase contrast MR (PCMR) velocity data, measured in vivo. Two simulations were conducted with identical geometry, flow rates, and fluid parameters: (1) Simulation 1 used in vivo, measured velocity distributions as time-varying boundary conditions, and (2) Simulation 2 used idealized, fully-developed velocity profiles as boundary conditions. Results The position and extent of negative axial velocity regions (NAVR) vary between the two simulations at any given point in time, and these regions vary temporally within each simulation. The combination of inlet velocity boundary conditions, geometry, and flow waveforms influences NAVRs. In particular, the combination of flow division and the location of the velocity peak with respect to individual carotid geometry landmarks (bifurcation apex position and the departure angle of the IC) influences the size and location of these reversed flow zones. Average axial wall shear stress (WSS) distributions are qualitatively similar for the two simulations; however, instantaneous WSS values vary with the choice of velocity boundary conditions. Conclusions By developing subject-specific simulations from in vivo measured geometry and flow data and varying the velocity boundary conditions in otherwise identical models we isolated the effects of measured versus idealized velocity distributions on blood flow patterns. Choice of velocity distributions at boundary conditions are

  12. Carotid artery stenting: current and emerging options

    PubMed Central

    Morr, Simon; Lin, Ning; Siddiqui, Adnan H

    2014-01-01

    Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments. PMID:25349483

  13. Traumatic Pseudoaneurysm of Right Extracranial Internal Carotid Artery: A Rare Entity and Recent Advancement of Treatment with Minimally Invasive Technique.

    PubMed

    Ong, Joo Lian Julian; Jalaludin, Salmah

    2016-03-01

    The purpose is to describe a case of traumatic right extracranial internal carotid artery (EICA) pseudoaneurysm, which is a rare entity and the evolution of treatment from surgery to minimally invasive intervention by endovascular stenting and coiling. We reported a case of traumatic right EICA pseudoaneurysm who presented with multiple cranial nerve palsies. Multiple radiological examinations [including magnetic resonance imaging (MRI) with angiogram, computed tomography angiogram (CTA), and digital subtraction angiogram (DSA)] demonstrated right EICA pseudoaneurysm. The pseudoaneurysm was successfully treated with endovascular stenting and coiling. EICA pseudoaneurysm is a rare entity, and open surgery was the gold standard of treatment. Current technology allows endovascular stenting and coiling of pseudoaneurysm as an alternative treatment. It is minimally invasive, associated with lesser complications, better recovery and a shorter hospital stay. PMID:27547119

  14. The effect of age on the unfolding of elastin lamellae and collagen fibers with stretch in human carotid arteries.

    PubMed

    Samila, Z J; Carter, S A

    1981-10-01

    We measured folding of elastin lamellae and collagen fibers in human carotid arteries and correlated the results with the elastic properties of the vessels. Specimens cut into circumferential strips were stretched to various degrees, fixed, and stained for elastin and collagen. Folding was measured on photographic projections. Elastin lamellae unfolded quickly with initial stretch. In old vessels they did not straighten as much as in the young suggesting that the content of the interlamellar space may interfere with the unfolding. Collagen fibers straightened more during stretch in stiffer older vessels than in the young, already at low degrees of stretch. Young's modulus at extension of 5% appeared to correlate with unfolding of elastin lamellae in young extensible vessels. The modulus correlated significantly with unfolding of collagen fibers at extensions of 15% and greater, and the slope of the regression of the modulus on folding increased with stretch. Our findings provide for the first time morphologic evidence for the role of elastin lamellae in the determination of the elastic properties at low extensions, for the importance of collagen fibers in increasing stiffness with further stretch, and for the relationship between increased stiffness with age and the earlier recruitment of the collagen fibers.

  15. Ex Vivo and in Silico Study of Human Common Carotid Arteries Pressure Response in Physiological and Inverted State

    NASA Astrophysics Data System (ADS)

    Piechna, A.; Cieślicki, K.; Lombarski, L.; Ciszek, B.

    2015-02-01

    Arterial walls are a multilayer structures with nonlinear material characteristics. Furthermore, residual stresses exist in unloaded state (zero-pressure condition) and they affect arterial behavior. To investigate these phenomena a number of theoretical and numerical studies were performed, however no experimental validation was proposed and realized yet. We cannot get rid of residual stresses without damaging the arterial segment. In this paper we propose a novel experiment to validate a numerical model of artery with residual stresses. The inspiration for our study originates from experiments made by Dobrin on dogs' arteries (1999). We applied the idea of turning the artery inside out. After such an operation the sequence of layer is reversed and the residual stresses are re-ordered. We performed several pressure-inflation tests on human Common Carotid Arteries (CCA) in normal and inverted configurations. The nonlinear responses of arterial behavior were obtained and compared to the numerical model. Computer simulations were carried out using the commercial software which applied the finite element method (FEM). Then, these results were discussed.

  16. A Perfusion-based Human Cadaveric Model for Management of Carotid Artery Injury during Endoscopic Endonasal Skull Base Surgery.

    PubMed

    Pham, Martin; Kale, Aydemir; Marquez, Yvette; Winer, Jesse; Lee, Brian; Harris, Brianna; Minnetti, Michael; Carey, Joseph; Giannotta, Steven; Zada, Gabriel

    2014-10-01

    Objective To create and develop a reproducible and realistic training environment to prepare residents and trainees for arterial catastrophes during endoscopic endonasal surgery. Design An artificial blood substitute was perfused at systolic blood pressures in eight fresh human cadavers to mimic intraoperative scenarios. Setting The USC Keck School of Medicine Fresh Tissue Dissection Laboratory was used as the training site. Participants Trainees were USC neurosurgery residents and junior faculty. Main Outcome A 5-point questionnaire was used to assess pre- and posttraining confidence scores. Results High-pressure extravasation at normal arterial blood pressure mimicked real intraoperative internal carotid artery (ICA) injury. Residents developed psychomotor skills required to achieve hemostasis using suction, cottonoids, and muscle grafts. Questionnaire responses from all trainees reported a realistic experience enhanced by the addition of the perfusion model. Conclusions The addition of an arterial perfusion system to fresh tissue cadavers is among the most realistic training models available. This enables the simulation of rare intraoperative scenarios such as ICA injury. Strategies for rapid hemostasis and implementation of techniques including endoscope manipulation, suction, and packing can all be rehearsed via this novel paradigm. PMID:25301092

  17. Human factors challenges for advanced process control

    SciTech Connect

    Stubler, W.F.; O`Hara, J..M.

    1996-08-01

    New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls.

  18. Technological advances for studying human behavior

    NASA Technical Reports Server (NTRS)

    Roske-Hofstrand, Renate J.

    1990-01-01

    Technological advances for studying human behavior are noted in viewgraph form. It is asserted that performance-aiding systems are proliferating without a fundamental understanding of how they would interact with the humans who must control them. Two views of automation research, the hardware view and the human-centered view, are listed. Other viewgraphs give information on vital elements for human-centered research, a continuum of the research process, available technologies, new technologies for persistent problems, a sample research infrastructure, the need for metrics, and examples of data-link technology.

  19. Biaxial mechanical properties of the human thoracic and abdominal aorta, common carotid, subclavian, renal and common iliac arteries.

    PubMed

    Kamenskiy, Alexey V; Dzenis, Yuris A; Kazmi, Syed A Jaffar; Pemberton, Mark A; Pipinos, Iraklis I; Phillips, Nick Y; Herber, Kyle; Woodford, Thomas; Bowen, Robert E; Lomneth, Carol S; MacTaggart, Jason N

    2014-11-01

    The biomechanics of large- and medium-sized arteries influence the pathophysiology of arterial disease and the response to therapeutic interventions. However, a comprehensive comparative analysis of human arterial biaxial mechanical properties has not yet been reported. Planar biaxial extension was used to establish the passive mechanical properties of human thoracic (TA, [Formula: see text]) and abdominal (AA, [Formula: see text]) aorta, common carotid (CCA, [Formula: see text]), subclavian (SA, [Formula: see text]), renal (RA, [Formula: see text]) and common iliac (CIA, [Formula: see text]) arteries from 11 deceased subjects ([Formula: see text] years old). Histological evaluation determined the structure of each specimen. Experimental data were used to determine constitutive parameters for a structurally motivated nonlinear anisotropic constitutive model. All arteries demonstrated appreciable anisotropy and large nonlinear deformations. Most CCA, SA, TA, AA and CIA specimens were stiffer longitudinally, while most RAs were stiffer circumferentially. A switch in anisotropy was occasionally demonstrated for all arteries. The CCA was the most compliant, least anisotropic and least frequently diseased of all arteries, while the CIA and AA were the stiffest and the most diseased. The severity of atherosclerosis correlated with age, but was not affected by laterality. Elastin fibers in the aorta, SA and CCA were uniformly and mostly circumferentially distributed throughout the media, while in the RA and CIA, elastin was primarily axially aligned and concentrated in the external elastic lamina. Constitutive modeling provided good fits to the experimental data for most arteries. Biomechanical and architectural features of major arteries differ depending on location and functional environment. A better understanding of localized arterial mechanical properties may support the development of site-specific treatment modalities for arterial disease.

  20. Population in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Sharma, Martha B.

    2000-01-01

    Addresses the population section of the Advanced Placement course outline for human geography, focusing on four themes: (1) geographical analysis of population; (2) population distribution and composition; (3) population growth and decline over time and space; and (4) population movement. Identifies strategies for instructional activities.…

  1. Carotid body chemoreflex: a driver of autonomic abnormalities in sleep apnoea.

    PubMed

    Prabhakar, Nanduri R

    2016-08-01

    What is the topic of this review? This article presents emerging evidence for heightened carotid body chemoreflex activity as a major driver of sympathetic activation and hypertension in sleep apnoea patients. What advances does it heighlight? This article discusses the recent advances on cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex in experimental models of sleep apnoea. The carotid bodies are the principal peripheral chemoreceptors for detecting changes in arterial blood oxygen concentration, and the resulting chemoreflex is a potent regulator of the sympathetic tone, blood pressure and breathing. Sleep apnoea is a disease of the respiratory system that affects several million adult humans. Apnoeas occur during sleep, often as a result of obstruction of the upper airway (obstructive sleep apnoea) or because of defective respiratory rhythm generation by the CNS (central sleep apnoea). Patients with sleep apnoea exhibit several co-morbidities, with the most notable among them being heightened sympathetic nerve activity and hypertension. Emerging evidence suggests that intermittent hypoxia resulting from periodic apnoea stimulates the carotid body, and the ensuing chemoreflex mediates the increased sympathetic tone and hypertension in sleep apnoea patients. Rodent models of intermittent hypoxia that simulate the O2 saturation profiles encountered during sleep apnoea have provided important insights into the cellular and molecular mechanisms underlying the heightened carotid body chemoreflex. This article describes how intermittent hypoxia affects the carotid body function and discusses the cellular, molecular and epigenetic mechanisms underlying the exaggerated chemoreflex. PMID:27474260

  2. Best evidence for medical therapy for carotid artery stenosis.

    PubMed

    Constantinou, Jason; Jayia, Parveen; Hamilton, George

    2013-10-01

    Carotid atheromatous disease is an important cause of stroke and represents a key target in stroke prevention. Randomized trials have shown the efficacy of carotid endarterectomy in secondary stroke prevention. Carotid stenting presents a less invasive alternative to surgical intervention. Advances in medical management, if compliance can be ensured, are leading to improvement in outcomes when implemented as sole therapy in the treatment of atherosclerotic carotid stenosis. This includes lifestyle modification, blood pressure control, and antiplatelet and statin therapy. Over the last 20 years, the annual rate of ipsilateral stroke associated with asymptomatic carotid stenosis has decreased from 2% to 4% to less than 1%. This is largely due to improvements in medical therapy. However, despite numerous trials and years of clinical research, the optimal management of symptomatic and asymptomatic carotid disease remains controversial. This article presents and summarizes the evidence supporting best medical treatment for carotid artery stenosis.

  3. Low Endogenous Secretory Receptor for Advanced Glycation End-Products Levels Are Associated With Inflammation and Carotid Atherosclerosis in Prediabetes.

    PubMed

    Di Pino, Antonino; Urbano, Francesca; Zagami, Rose Maria; Filippello, Agnese; Di Mauro, Stefania; Piro, Salvatore; Purrello, Francesco; Rabuazzo, Agata Maria

    2016-04-01

    Pre-diabetes is associated with advanced vascular damage. Our data shows that subjects with pre-diabetes exhibited low esRAGE plasma levels and gene expression, which are inversely related with markers of inflammation and atherosclerotic risk.

  4. Short-duration spaceflight impairs human carotid baroreceptor-cardiac reflex responses

    NASA Technical Reports Server (NTRS)

    Fritsch, Janice M.; Charles, John B.; Bennett, Barbara S.; Jones, Michele M.; Eckberg, Dwain L.

    1992-01-01

    The effect of a spaceflight on the vagally mediated baroreceptor-cardiac reflex responses of humans were investigated by measuring the responses (provoked by neck pressure changes) in supine position and the heart rate and blood pressure in the supine and standing positions in 16 astronauts before and after 4- to 5-day long Space Shuttle missions. The results showed that exposures to spaceflight resulted in reduced baseline levels of the vagal-cardiac outflow and the vagally mediated responses to changes of the arterial baroreceptor input and that these changes contribute to postflight reductions of astronauts' ability to maintain standing arterial pressures.

  5. Short-duration spaceflight impairs human carotid baroreceptor-cardiac reflex responses

    NASA Astrophysics Data System (ADS)

    Fritsch, Janice M.; Charles, John B.; Bennett, Barbara S.; Jones, Michele M.; Eckberg, Dwain L.

    1992-08-01

    The effect of a spaceflight on the vagally mediated baroreceptor-cardiac reflex responses of humans were investigated by measuring the responses (provoked by neck pressure changes) in supine position and the heart rate and blood pressure in the supine and standing positions in 16 astronauts before and after 4- to 5-day long Space Shuttle missions. The results showed that exposures to spaceflight resulted in reduced baseline levels of the vagal-cardiac outflow and the vagally mediated responses to changes of the arterial baroreceptor input and that these changes contribute to postflight reductions of astronauts' ability to maintain standing arterial pressures.

  6. Carotid Artery Disease

    MedlinePlus

    ... brain with blood. If you have carotid artery disease, the arteries become narrow, usually because of atherosclerosis. ... one of the causes of stroke. Carotid artery disease often does not cause symptoms, but there are ...

  7. Blockade of Ets-1 attenuates epidermal growth factor-dependent collagen loss in human carotid plaque smooth muscle cells.

    PubMed

    Rao, Velidi H; Rai, Vikrant; Stoupa, Samantha; Agrawal, Devendra K

    2015-09-15

    Although degradation of extracellular matrix by matrix metalloproteinases (MMPs) is thought to be involved in symptomatic (S) carotid plaques in atherosclerosis, the mechanisms of MMP expression are poorly understood. Here, we demonstrate that collagen loss in vascular smooth vessel cells (VSMCs) isolated from S plaques was induced by epidermal growth factor (EGF) through the activation of p38-MAPK and JNK-MAPK pathways. Inhibitors of p38-MAPK and JNK-MAPK signaling pathways downregulated the expression of MMP-1 and MMP-9. In addition, we examined whether v-ets erythroblastosis virus E26 oncogene homologue 1 (Ets-1), an important regulator of different genes, is involved in destabilizing S plaques in patients with carotid stenosis. We demonstrate that EGF induces Ets-1 expression and decreases interstitial and basement membrane collagen in vascular smooth muscle cells (VSMCs) from patients with carotid stenosis. Increased expression of MMP-1 and -9 and decreased collagen mRNA transcripts were also found in Ets-1-overexpressed VSMCs. Transfection with both dominant-negative form of Ets-1 and small interfering RNA blocked EGF-induced MMP-1 and -9 expressions and increased the mRNA transcripts for collagen I (α1) and collagen III (α1) in S compared with asymptomatic (AS) carotid plaques. Inhibitors of p38-MAPK (SB202190) and JNK-MAPK (SP600125) signaling pathways decreased the expression of Ets-1, MMP-1, and MMP-9 and increased collagen type I and III expression in EGF-treated VSMCs. This study provides a mechanistic insight into the role of Ets-1 in the plaque destabilization in patients with carotid stenosis involving p38-MAPK and JNK signaling pathways.

  8. MMP-1 and MMP-9 regulate epidermal growth factor-dependent collagen loss in human carotid plaque smooth muscle cells.

    PubMed

    Rao, Velidi H; Kansal, Vikash; Stoupa, Samantha; Agrawal, Devendra K

    2014-02-01

    Mechanisms underlying the rupture of atherosclerotic plaque, a crucial factor in the development of myocardial infarction and stroke, are not well defined. Here, we examined the role of epidermal growth factor (EGF)-mediated matrix metalloproteinases (MMP) on the stability of interstitial collagens in vascular smooth muscle cells (VSMCs) isolated from carotid endarterectomy tissues of symptomatic and asymptomatic patients with carotid stenosis. VSMCs isolated from the carotid plaques of both asymptomatic and symptomatic patients were treated with EGF. The MMP-9 activity was quantified by gelatin zymography and the analysis of mRNA transcripts and protein for MMP-9, MMP-1, EGFR and collagen types I, Col I(α1) and collagen type III, Col III(α1) were analyzed by qPCR and immunofluorescence, respectively. The effect of EGF treatment to increase MMP-9 activity and mRNA transcripts for MMP-9, MMP-1, and EGFR and to decrease mRNA transcripts for Col I(α1) and Col III(α1) was threefold to fourfold greater in VSMCs isolated from the carotid plaques of symptomatic than asymptomatic patients. Inhibitors of EGFR (AG1478) and a small molecule inhibitor of MMP-9 decreased the MMP9 expression and upregulated Col I(α1) and Col III(α1) in EGF-treated VSMCs of both groups. Additionally, the magnitude in decreased MMP-9 mRNA and increased Col I(α1) and Col III(α1) due to knockdown of MMP-9 gene with siRNA in EGF-treated VSMCs was significantly greater in the symptomatic group than the asymptomatic group. Thus, a selective blockade of both EGFR and MMP-9 may be a novel strategy and a promising target for stabilizing vulnerable plaques in patients with carotid stenosis.

  9. Advances in Computationally Modeling Human Oral Bioavailability

    PubMed Central

    Wang, Junmei; Hou, Tingjun

    2015-01-01

    Although significant progress has been made in experimental high throughput screening (HTS) of ADME (absorption, distribution, metabolism, excretion) and pharmacokinetic properties, the ADME and Toxicity (ADME-Tox) in silico modeling is still indispensable in drug discovery as it can guide us to wisely select drug candidates prior to expensive ADME screenings and clinical trials. Compared to other ADME-Tox properties, human oral bioavailability (HOBA) is particularly important but extremely difficult to predict. In this paper, the advances in human oral bioavailability modeling will be reviewed. Moreover, our deep insight on how to construct more accurate and reliable HOBA QSAR and classification models will also discussed. PMID:25582307

  10. Smooth muscle cells in human atherosclerosis: proteomic profiling reveals differences in expression of Annexin A1 and mitochondrial proteins in carotid disease.

    PubMed

    Viiri, Leena E; Full, Louise E; Navin, Tina J; Begum, Shajna; Didangelos, Athanasios; Astola, Nagore; Berge, Rolf K; Seppälä, Ilkka; Shalhoub, Joseph; Franklin, Ian J; Perretti, Mauro; Lehtimäki, Terho; Davies, Alun H; Wait, Robin; Monaco, Claudia

    2013-01-01

    Smooth muscle cells (SMC) contribute to the development and stability of atherosclerotic lesions. The molecular mechanisms that mediate their properties are incompletely defined. We employed proteomics and in vitro functional assays to identify the unique characteristics of intimal SMC isolated from human carotid endarterectomy specimens and medial SMC from thoracic aortas and carotids. We verified our findings in the Tampere Vascular Study. Human atheroma-derived SMC exhibit decreased expression of mitochondrial proteins ATP Synthase subunit-beta and Aldehyde dehydrogenase 2, and decreased mitochondrial activity when compared to control SMC. Moreover, a comparison between plaque-derived SMC isolated from patients with or without recent acute cerebrovascular symptoms uncovered an increase in Annexin A1, an endogenous anti-inflammatory protein, in the asymptomatic group. The deletion of Annexin A1 or the blockade of its signaling in SMC resulted in increased cytokine production at baseline and after stimulation with the pro-inflammatory cytokine Tumor Necrosis Factor α. In summary, our proteomics and biochemical analysis revealed mitochondrial damage in human plaque-derived SMC as well as a role of Annexin A1 in reducing the production of pro-inflammatory mediators in SMC.

  11. Advances in Human B Cell Phenotypic Profiling

    PubMed Central

    Kaminski, Denise A.; Wei, Chungwen; Qian, Yu; Rosenberg, Alexander F.; Sanz, Ignacio

    2012-01-01

    To advance our understanding and treatment of disease, research immunologists have been called-upon to place more centralized emphasis on impactful human studies. Such endeavors will inevitably require large-scale study execution and data management regulation (“Big Biology”), necessitating standardized and reliable metrics of immune status and function. A well-known example setting this large-scale effort in-motion is identifying correlations between eventual disease outcome and T lymphocyte phenotype in large HIV-patient cohorts using multiparameter flow cytometry. However, infection, immunodeficiency, and autoimmunity are also characterized by correlative and functional contributions of B lymphocytes, which to-date have received much less attention in the human Big Biology enterprise. Here, we review progress in human B cell phenotyping, analysis, and bioinformatics tools that constitute valuable resources for the B cell research community to effectively join in this effort. PMID:23087687

  12. Future Management of Carotid Stenosis: Role of Urgent Carotid Interventions in the Acutely Symptomatic Carotid Patient and Best Medical Therapy for Asymptomatic Carotid Disease

    PubMed Central

    Bazan, Hernan A.; Smith, Taylor A.; Donovan, Melissa J.; Sternbergh, W. Charles

    2014-01-01

    Background Stroke is the fourth leading cause of death in the United States, leading to devastating disability. Most strokes are ischemic, and nearly one-third of these are caused by carotid disease. The primary mechanism of carotid-related stroke is an atheroembolic event from an unstable atherosclerotic plaque rupture. In the 1990s, randomized trials demonstrated the benefit of carotid endarterectomy (CEA) in reducing the risk of stroke in both symptomatic and asymptomatic carotid disease. Methods We review best medical therapy (BMT) for asymptomatic carotid disease and recent randomized trials comparing CEA and carotid angioplasty stenting (CAS), and we discuss the role of urgent carotid interventions in patients with acute neurologic symptoms. Results In 2010, 2 large trials demonstrated the efficacy of CAS in select patients, although CAS was associated with an increased procedural stroke risk compared to CEA. An age effect was observed; patients >75 years do worse with CAS compared to CEA. As BMT has evolved in the past decade, a future trial (CREST-2) will address whether BMT is equal to intervention (CEA or CAS) in asymptomatic carotid disease. In a subgroup of patients with asymptomatic carotid disease, CEA plus BMT will likely remain the mainstay therapy for carotid disease compared to BMT alone. CEA and CAS will continue to play complementary roles in the future, as CAS will be done in select patients in whom CEA cannot be undertaken because of high-risk anatomical or medical conditions. Finally, a role for urgent carotid interventions in a select group of patients who present with acute neurologic symptoms is developing as a way to prevent recurrent stroke after an initial carotid plaque rupture event. Conclusion CAS has an increasingly higher risk of stroke with advancing age. Patients treated with CAS have a 1.76-fold increased risk of stroke (95% CI, 1.35-2.31) with each 10-year increase in age. No such age effect is seen in patients treated with CEA

  13. Differential expression of oxidation-specific epitopes and apolipoprotein(a) in progressing and ruptured human coronary and carotid atherosclerotic lesions.

    PubMed

    van Dijk, Rogier A; Kolodgie, Frank; Ravandi, Amir; Leibundgut, Gregor; Hu, Patrick P; Prasad, Anand; Mahmud, Ehtisham; Dennis, Edward; Curtiss, Linda K; Witztum, Joseph L; Wasserman, Bruce A; Otsuka, Fumiyuki; Virmani, Renu; Tsimikas, Sotirios

    2012-12-01

    The relationships between oxidation-specific epitopes (OSE) and lipoprotein (a) [Lp(a)] and progressive atherosclerosis and plaque rupture have not been determined. Coronary artery sections from sudden death victims and carotid endarterectomy specimens were immunostained for apoB-100, oxidized phospholipids (OxPL), apo(a), malondialdehyde-lysine (MDA), and MDA-related epitopes detected by antibody IK17 and macrophage markers. The presence of OxPL captured in carotid and saphenous vein graft distal protection devices was determined with LC-MS/MS. In coronary arteries, OSE and apo(a) were absent in normal coronary arteries and minimally present in early lesions. As lesions progressed, apoB and MDA epitopes did not increase, whereas macrophage, apo(a), OxPL, and IK17 epitopes increased proportionally, but they differed according to plaque type and plaque components. Apo(a) epitopes were present throughout early and late lesions, especially in macrophages and the necrotic core. IK17 and OxPL epitopes were strongest in late lesions in macrophage-rich areas, lipid pools, and the necrotic core, and they were most specifically associated with unstable and ruptured plaques. Specific OxPL were present in distal protection devices. Human atherosclerotic lesions manifest a differential expression of OSEs and apo(a) as they progress, rupture, and become clinically symptomatic. These findings provide a rationale for targeting OSE for biotheranostic applications in humans. PMID:22969153

  14. The influence of constitutive law choice used to characterise atherosclerotic tissue material properties on computing stress values in human carotid plaques.

    PubMed

    Teng, Zhongzhao; Yuan, Jianmin; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J; Wang, Shuo; Lu, Qingsheng; Gillard, Jonathan H

    2015-11-01

    Calculating high stress concentration within carotid atherosclerotic plaques has been shown to be complementary to anatomical features in assessing vulnerability. Reliability of stress calculation may depend on the constitutive laws/strain energy density functions (SEDFs) used to characterize tissue material properties. Different SEDFs, including neo-Hookean, one-/two-term Ogden, Yeoh, 5-parameter Mooney-Rivlin, Demiray and modified Mooney-Rivlin, have been used to describe atherosclerotic tissue behavior. However, the capacity of SEDFs to fit experimental data and the difference in the stress calculation remains unexplored. In this study, seven SEDFs were used to fit the stress-stretch data points of media, fibrous cap, lipid and intraplaque hemorrhage/thrombus obtained from 21 human carotid plaques. Semi-analytic solution, 2D structure-only and 3D fully coupled fluid-structure interaction (FSI) analyses were used to quantify stress using different SEDFs and the related material stability examined. Results show that, except for neo-Hookean, all other six SEDFs fitted the experimental points well, with vessel stress distribution in the circumferential and radial directions being similar. 2D structural-only analysis was successful for all seven SEDFs, but 3D FSI were only possible with neo-Hookean, Demiray and modified Mooney-Rivlin models. Stresses calculated using Demiray and modified Mooney-Rivlin models were nearly identical. Further analyses indicated that the energy contours of one-/two-term Ogden and 5-parameter Mooney-Rivlin models were not strictly convex and the material stability indictors under homogeneous deformations were not always positive. In conclusion, considering the capacity in characterizing material properties and stabilities, Demiray and modified Mooney-Rivlin SEDF appear practical choices for mechanical analyses to predict the critical mechanical conditions within carotid atherosclerotic plaques. PMID:26472305

  15. The influence of constitutive law choice used to characterise atherosclerotic tissue material properties on computing stress values in human carotid plaques

    PubMed Central

    Teng, Zhongzhao; Yuan, Jianmin; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J.; Wang, Shuo; Lu, Qingsheng; Gillard, Jonathan H.

    2015-01-01

    Calculating high stress concentration within carotid atherosclerotic plaques has been shown to be complementary to anatomical features in assessing vulnerability. Reliability of stress calculation may depend on the constitutive laws/strain energy density functions (SEDFs) used to characterize tissue material properties. Different SEDFs, including neo-Hookean, one-/two-term Ogden, Yeoh, 5-parameter Mooney–Rivlin, Demiray and modified Mooney–Rivlin, have been used to describe atherosclerotic tissue behavior. However, the capacity of SEDFs to fit experimental data and the difference in the stress calculation remains unexplored. In this study, seven SEDFs were used to fit the stress–stretch data points of media, fibrous cap, lipid and intraplaque hemorrhage/thrombus obtained from 21 human carotid plaques. Semi-analytic solution, 2D structure-only and 3D fully coupled fluid-structure interaction (FSI) analyses were used to quantify stress using different SEDFs and the related material stability examined. Results show that, except for neo-Hookean, all other six SEDFs fitted the experimental points well, with vessel stress distribution in the circumferential and radial directions being similar. 2D structural-only analysis was successful for all seven SEDFs, but 3D FSI were only possible with neo-Hookean, Demiray and modified Mooney–Rivlin models. Stresses calculated using Demiray and modified Mooney–Rivlin models were nearly identical. Further analyses indicated that the energy contours of one-/two-term Ogden and 5-parameter Mooney–Rivlin models were not strictly convex and the material stability indictors under homogeneous deformations were not always positive. In conclusion, considering the capacity in characterizing material properties and stabilities, Demiray and modified Mooney–Rivlin SEDF appear practical choices for mechanical analyses to predict the critical mechanical conditions within carotid atherosclerotic plaques. PMID:26472305

  16. The influence of constitutive law choice used to characterise atherosclerotic tissue material properties on computing stress values in human carotid plaques.

    PubMed

    Teng, Zhongzhao; Yuan, Jianmin; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J; Wang, Shuo; Lu, Qingsheng; Gillard, Jonathan H

    2015-11-01

    Calculating high stress concentration within carotid atherosclerotic plaques has been shown to be complementary to anatomical features in assessing vulnerability. Reliability of stress calculation may depend on the constitutive laws/strain energy density functions (SEDFs) used to characterize tissue material properties. Different SEDFs, including neo-Hookean, one-/two-term Ogden, Yeoh, 5-parameter Mooney-Rivlin, Demiray and modified Mooney-Rivlin, have been used to describe atherosclerotic tissue behavior. However, the capacity of SEDFs to fit experimental data and the difference in the stress calculation remains unexplored. In this study, seven SEDFs were used to fit the stress-stretch data points of media, fibrous cap, lipid and intraplaque hemorrhage/thrombus obtained from 21 human carotid plaques. Semi-analytic solution, 2D structure-only and 3D fully coupled fluid-structure interaction (FSI) analyses were used to quantify stress using different SEDFs and the related material stability examined. Results show that, except for neo-Hookean, all other six SEDFs fitted the experimental points well, with vessel stress distribution in the circumferential and radial directions being similar. 2D structural-only analysis was successful for all seven SEDFs, but 3D FSI were only possible with neo-Hookean, Demiray and modified Mooney-Rivlin models. Stresses calculated using Demiray and modified Mooney-Rivlin models were nearly identical. Further analyses indicated that the energy contours of one-/two-term Ogden and 5-parameter Mooney-Rivlin models were not strictly convex and the material stability indictors under homogeneous deformations were not always positive. In conclusion, considering the capacity in characterizing material properties and stabilities, Demiray and modified Mooney-Rivlin SEDF appear practical choices for mechanical analyses to predict the critical mechanical conditions within carotid atherosclerotic plaques.

  17. Carotid labyrinth of amphibians.

    PubMed

    Kusakabe, Tatsumi

    2002-11-01

    The amphibian carotid labyrinth is a characteristic maze-like vascular expansion at the bifurcation of the common carotid artery into the internal and external carotid arteries. The carotid labyrinths of anurans are spherical and those of urodeles are oblong. In the intervascular stroma of both anuran and urodelan carotid labyrinths, the glomus cells (type I cells, chief cells) are distributed singly or in clusters between connective tissue cells and smooth muscle cells. In fluorescence histochemistry, the glomus cells emit intense fluorescence for biogenic monoamines. In fine structure, the glomus cells are characterized by a number of dense-cored vesicles in their cytoplasm. The glomus cells have long, thin cytoplasmic processes, some of which are closely associated with smooth muscle cells, endothelial cells, and pericytes. Afferent, efferent, and reciprocal synapses are found on the glomus cells. The morphogenesis of the carotid labyrinth starts in the larvae at the point where the carotid arch descends to the internal gills. Through the early stages of larval development, the slightly expanded region of the external carotid artery becomes closely connected with the carotid arch. By the end of the foot stage, the expanded region becomes globular, and at the final stage of metamorphosis the carotid labyrinth is close to its adult form. In fine structure, the glomus cells appear as early as the initial stage of larval development. At the middle stages of development, the number of dense-cored vesicles increases remarkably. Distinct afferent synapses are found in juveniles, although efferent synapses can be seen during metamorphosis. The carotid labyrinth is innervated by nerve fibers containing several kinds of regulatory neuropeptides. Double-immunolabeling in combination with a multiple dye filter system demonstrates the coexistence of two different neuropeptides. The amphibian carotid labyrinth has been electrophysiologically confirmed to have arterial chemo

  18. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    PubMed

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P < 0.01). Using the spectrum analysis approach, the fall in scBRS with hypoxia was attenuated with infusion of low-dose dopamine (P < 0.01). The decrease in baroreflex sensitivity to rising pressures (scBRS "up-up") was also attenuated with low-dose dopamine (P < 0.05). However, dopamine did not attenuate the decrease in baroreflex sensitivity to falling pressures (scBRS "down-down"; P > 0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes. PMID:27418545

  19. Intermittent hypoxia and arterial blood pressure control in humans: role of the peripheral vasculature and carotid baroreflex.

    PubMed

    Tremblay, Joshua C; Boulet, Lindsey M; Tymko, Michael M; Foster, Glen E

    2016-09-01

    Intermittent hypoxia (IH) occurs in association with obstructive sleep apnea and likely contributes to the pathogenesis of hypertension. The purpose of this study was to examine the putative early adaptations at the level of the peripheral vasculature and carotid baroreflex (CBR) that may promote the development of hypertension. Ten healthy male participants (26 ± 1 yr, BMI = 24 ± 1 kg/m(2)) were exposed to 6 h of IH (1-min cycles of normoxia and hypoxia) and SHAM in a single-blinded, counterbalanced crossover study design. Ambulatory blood pressure was measured during each condition and the following night. Vascular strain of the carotid and femoral artery, a measure of localized arterial stiffness, and hemodynamic shear patterns in the brachial and femoral arteries were measured during each condition. Brachial artery reactive hyperemia flow-mediated vasodilation was assessed before and after each condition as a measure of endothelial function. CBR function and its control over leg vascular conductance (LVC) were measured after each condition with a variable-pressure neck chamber. Intermittent hypoxia 1) increased nighttime pulse pressure by 3.2 ± 1.3 mmHg, 2) altered femoral but not brachial artery hemodynamics, 3) did not affect brachial artery endothelial function, 4) reduced vascular strain in the carotid and possibly femoral artery, and 5) shifted CBR mean arterial pressure (MAP) to higher MAP while blunting LVC responses to CBR loading. These results suggest limb-specific vascular impairments, reduced vascular strain, and CBR resetting combined with blunted LVC responses are factors in the early pathogenesis of IH-induced development of hypertension. PMID:27402667

  20. Reductions in carotid chemoreceptor activity with low-dose dopamine improves baroreflex control of heart rate during hypoxia in humans.

    PubMed

    Mozer, Michael T; Holbein, Walter W; Joyner, Michael J; Curry, Timothy B; Limberg, Jacqueline K

    2016-07-01

    The purpose of the present investigation was to examine the contribution of the carotid body chemoreceptors to changes in baroreflex control of heart rate with exposure to hypoxia. We hypothesized spontaneous cardiac baroreflex sensitivity (scBRS) would be reduced with hypoxia and this effect would be blunted when carotid chemoreceptor activity was reduced with low-dose dopamine. Fifteen healthy adults (11 M/4 F) completed two visits randomized to intravenous dopamine or placebo (saline). On each visit, subjects were exposed to 5-min normoxia (~99% SpO2), followed by 5-min hypoxia (~84% SpO2). Blood pressure (intra-arterial catheter) and heart rate (ECG) were measured continuously and scBRS was assessed by spectrum and sequence methodologies. scBRS was reduced with hypoxia (P < 0.01). Using the spectrum analysis approach, the fall in scBRS with hypoxia was attenuated with infusion of low-dose dopamine (P < 0.01). The decrease in baroreflex sensitivity to rising pressures (scBRS "up-up") was also attenuated with low-dose dopamine (P < 0.05). However, dopamine did not attenuate the decrease in baroreflex sensitivity to falling pressures (scBRS "down-down"; P > 0.05). Present findings are consistent with a reduction in scBRS with systemic hypoxia. Furthermore, we show this effect is partially mediated by the carotid body chemoreceptors, given the fall in scBRS is attenuated when activity of the chemoreceptors is reduced with low-dose dopamine. However, the improvement in scBRS with dopamine appears to be specific to rising blood pressures. These results may have important implications for impairments in baroreflex function common in disease states of acute and/or chronic hypoxemia, as well as the experimental use of dopamine to assess such changes.

  1. Intermittent hypoxia and arterial blood pressure control in humans: role of the peripheral vasculature and carotid baroreflex.

    PubMed

    Tremblay, Joshua C; Boulet, Lindsey M; Tymko, Michael M; Foster, Glen E

    2016-09-01

    Intermittent hypoxia (IH) occurs in association with obstructive sleep apnea and likely contributes to the pathogenesis of hypertension. The purpose of this study was to examine the putative early adaptations at the level of the peripheral vasculature and carotid baroreflex (CBR) that may promote the development of hypertension. Ten healthy male participants (26 ± 1 yr, BMI = 24 ± 1 kg/m(2)) were exposed to 6 h of IH (1-min cycles of normoxia and hypoxia) and SHAM in a single-blinded, counterbalanced crossover study design. Ambulatory blood pressure was measured during each condition and the following night. Vascular strain of the carotid and femoral artery, a measure of localized arterial stiffness, and hemodynamic shear patterns in the brachial and femoral arteries were measured during each condition. Brachial artery reactive hyperemia flow-mediated vasodilation was assessed before and after each condition as a measure of endothelial function. CBR function and its control over leg vascular conductance (LVC) were measured after each condition with a variable-pressure neck chamber. Intermittent hypoxia 1) increased nighttime pulse pressure by 3.2 ± 1.3 mmHg, 2) altered femoral but not brachial artery hemodynamics, 3) did not affect brachial artery endothelial function, 4) reduced vascular strain in the carotid and possibly femoral artery, and 5) shifted CBR mean arterial pressure (MAP) to higher MAP while blunting LVC responses to CBR loading. These results suggest limb-specific vascular impairments, reduced vascular strain, and CBR resetting combined with blunted LVC responses are factors in the early pathogenesis of IH-induced development of hypertension.

  2. Laboratory Diagnosis of Human Rabies: Recent Advances

    PubMed Central

    Mani, Reeta Subramaniam; Madhusudana, Shampur Narayan

    2013-01-01

    Rabies, an acute progressive, fatal encephalomyelitis, transmitted most commonly through the bite of a rabid animal, is responsible for an estimated 61,000 human deaths worldwide. The true disease burden and public health impact due to rabies remain underestimated due to lack of sensitive laboratory diagnostic methods. Rapid diagnosis of rabies can help initiate prompt infection control and public health measures, obviate the need for unnecessary treatment/medical tests, and assist in timely administration of pre- or postexposure prophylactic vaccination to family members and medical staff. Antemortem diagnosis of human rabies provides an impetus for clinicians to attempt experimental therapeutic approaches in some patients, especially after the reported survival of a few cases of human rabies. Traditional methods for antemortem and postmortem rabies diagnosis have several limitations. Recent advances in technology have led to the improvement or development of several diagnostic assays which include methods for rabies viral antigen and antibody detection and assays for viral nucleic acid detection and identification of specific biomarkers. These assays which complement traditional methods have the potential to revolutionize rabies diagnosis in future. PMID:24348170

  3. Durability of carotid endarterectomy.

    PubMed

    Baker, W H; Hayes, A C; Mahler, D; Littooy, F N

    1983-07-01

    Carotid endarterectomy is the preferred treatment for patients with transient ischemic attacks and carotid stenosis. Although clinically these patients do well, the long-term fate of the operated carotid artery has not been well documented. To address this question, repeated noninvasive testing has been employed to follow our carotid endarterectomy patients since 1976. Supraorbital Doppler examination, oculoplethysmography-Kartchner, carotid phonoangiography and, later in this series, spectral analysis of the carotid Doppler velocities were performed after 193 endarterectomies. One hundred fifty-eight patients were initially tested within 3 months of operation, and 35 were initially tested 3 or more months after operation. Twenty-four arteries, four of which were symptomatic, had an initial abnormal test and are excluded from this study of carotid artery durability. Of the 169 patients with normal carotid tests, 36 had no further evaluation. Among the 133 patients who returned for serial testing from 1 to 60 months (mean 20 months), 115 carotid arteries continued to test normal at late follow-up but 18 subsequently developed test abnormalities. Ten had more than 75% stenosis, eight had 50% to 75% stenosis. Eight of these patients had contrast studies: three had normal findings; the five that had abnormal findings underwent reoperation. Interestingly, only two patients presented with symptoms appropriate to the abnormal test. The findings suggest that carotid endarterectomy is a reasonably durable operation. Recurrent stenosis was presumed or proven in 10% of 133 serially tested carotid arteries. This threat of restenosis makes long-term follow-up of these patients mandatory.

  4. Endothelial lipase is highly expressed in macrophages in advanced human atherosclerotic lesions.

    PubMed

    Bartels, Emil D; Nielsen, John E; Lindegaard, Marie L S; Hulten, Lillemor M; Schroeder, Torben V; Nielsen, Lars B

    2007-12-01

    Endothelial lipase (EL) is expressed in endothelial cells, and affects plasma lipoprotein metabolism by hydrolyzing phospholipids in HDL. To determine the cellular expression of EL mRNA and protein in human atherosclerotic lesions, we performed in situ hybridization and immunohistochemical studies on sections of carotid endarterectomy specimens from patients with symptomatic cerebrovascular disease. In each of eight patients, EL mRNA and/or protein were seen in areas between the necrotic core and the fibrotic cap where they colocalized with LPL and macrophage-specific CD68. Moreover, there was a positive association between the expression of EL mRNA and CD68 mRNA in plaques from 26 patients. The impact of differentiation from monocytes into macrophages, and subsequently foam cells (by incubation with acetylated LDL) on expression was studied using THP-1 monocytes and primary human monocytes. EL mRNA expression increased markedly when either type of monocytes was differentiated into macrophages. Upon further differentiation into foam cells EL mRNA decreased whereas protein levels remained high compared to monocytes. In conclusion, macrophages in advanced human atherosclerotic lesions display high levels of EL expression, and the level of EL expression varies greatly during transformation of blood monocytes into foam cells.

  5. Mass transport of low density lipoprotein in reconstructed hemodynamic environments of human carotid arteries: the role of volume and solute flux through the endothelium.

    PubMed

    Kim, Sungho; Giddens, Don P

    2015-04-01

    The accumulation of low density lipoprotein (LDL) in the arterial intima is a critical step in the initiation and progression of atheromatous lesions. In this study we examine subject-specific LDL transport into the intima of carotid bifurcations in three human subjects using a three-pore model for LDL mass transfer. Subject-specific carotid artery computational models were derived using magnetic resonance imaging (MRI) to obtain the geometry and phase-contract MRI (PC-MRI) to acquire pulsatile inflow and outflow boundary conditions for each subject. The subjects were selected to represent a wide range of anatomical configurations and different stages of atherosclerotic development from mild to moderate intimal thickening. A fluid-solid interaction (FSI) model was implemented in the computational fluid dynamics (CFD) approach in order to consider the effects of a compliant vessel on wall shear stress (WSS). The WSS-dependent response of the endothelium to LDL mass transfer was modeled by multiple pathways to include the contributions of leaky junctions, normal junctions, and transcytosis to LDL solute and plasma volume flux from the lumen into the intima. Time averaged WSS (TAWSS) over the cardiac cycle was computed to represent the spatial WSS distribution, and wall thickness (WTH) was determined from black blood MRI (BBMRI) so as to visualize intimal thickening patterns in the bifurcations. The regions which are exposed to low TAWSS correspond to elevated WTH and higher mass and volume flux via the leaky junctions. In all subjects, the maximum LDL solute flux was observed to be immediately downstream of the stenosis, supporting observations that existing atherosclerotic lesions tend to progress in the downstream direction of the stenosis.

  6. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  7. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  8. Carotid stenting and endarterectomy.

    PubMed

    Yip, Hon-Kan; Sung, Pei-Hsun; Wu, Chiung-Jen; Yu, Cheuk-Man

    2016-07-01

    Stroke, either ischemic or hemorrhagic, remains the second commonest cause of death worldwide in the last decade. Etiologies for ischemic stroke (IS) vary widely. Atherothrombotic occlusion is an essential cause to which carotid artery stenosis (CAS) is a major contributor. Administration of anti-platelet agent to patients with CAS has been shown to reduce incidence of long-term IS. In additional, in patients with symptomatic CAS, clinical trials have demonstrated that carotid endarterectomy (CEA) is superior to medical therapy for prevention of future CAS-related IS. However, CEA is not suitable for CAS post-radiotherapy or those located at higher level of the internal carotid artery; and major complications of this procedure including cranial nerve injuries have stimulated the interest of using percutaneous transfemoral carotid stenting as an alternative approach. Although transfemoral arterial approach of carotid stenting is not inferior to CEA in improving clinical outcomes, it has been reported to be associated with vascular complication and has its limitations in patients with athero-occlusive disease of abdominal aorta or bilateral iliac arteries, level II or III aortic arch, or bovine type carotid arterial anatomy. Therefore, transradial/transbrachial arterial approach has emerged as a novel method for carotid stenting. This article provides a critical review on interventional approaches for the treatment of CAS.

  9. Current status of carotid ultrasound in atherosclerosis

    PubMed Central

    2016-01-01

    Cardiovascular disease (CVD) primarily caused by atherosclerosis is a major cause of death and disability in developed countries. Sonographic carotid intima-media thickness (CIMT) is widely studied as a surrogate marker for detecting subclinical atherosclerosis for risk prediction and disease progress to guide medical intervention. However, there is no standardized CIMT measurement methodology in clinical studies resulting in inconsistent findings, thereby undermining the clinical value of CIMT. Increasing evidences show that CIMT alone has weak predictive value for CVD while CIMT including plaque presence consistently improves the predictive power. Quantification of plaque burden further enhances the predictive power beyond plaque presence. Sonographic carotid plaque characteristics have been found to be predictive of cerebral ischaemic events. With advances in ultrasound technology, enhanced assessment of carotid plaques is feasible to detect high-risk/vulnerable plaques, and provide risk assessment for ischemic stroke beyond measurement of luminal stenosis. PMID:27429912

  10. Carotid body tumors: a 40-year study.

    PubMed

    Farr, H W

    1980-01-01

    A total of 44 carotid body tumors were observed for over 40 years at Memorial Sloan-Kettering Cancer Center in New York. The true nature of th paraganglioma can remain obscure in those patients without prior tissue biopsy or sophisticated diagnostic studies. Eighteen patients came to surgery without a primary working diagnosis of the conditions, 43 percent of the seris. Significant advances in the preoperative workup of a cervical mass attached to the carotid sheath are now recommended: ultrasonography, radioisotope perfusion scanning, and selective carotid arteriography. Catecholamine determination should be considered for any paraganglioma exhibiting vasomotor instability or hypertension. Prior to 1945 the carotid bifurcation was sacrificed eight times with a 50 percent mortality occurring in relatively youthful subjects. In the 35 years since then, a more sophisticated surgical technique preserving the carotid circulation has resulted in over 30 resections with but one fatality. Multicentricity, both in the sporadic and the familial form, is characteristic of this rare tumor, also called "APUDoma." (APUD is an acronym derived from three of the most important characteristics of these cells: a high amine content, amine precursor uptake, and decarboxylation. Its malignant potential is beyond debate.

  11. Angioplasty and stent placement - carotid artery

    MedlinePlus

    Carotid angioplasty and stenting; CAS; Angioplasty - carotid artery; Carotid artery stenosis - angioplasty; ... Carotid angioplasty and stenting (CAS) is done using a small surgical cut. Your surgeon will make a surgical cut ...

  12. Morpheus: Advancing Technologies for Human Exploration

    NASA Technical Reports Server (NTRS)

    Olansen, Jon B.; Munday, Stephen R.; Mitchell, Jennifer D.; Baine, Michael

    2012-01-01

    NASA's Morpheus Project has developed and tested a prototype planetary lander capable of vertical takeoff and landing. Designed to serve as a vertical testbed (VTB) for advanced spacecraft technologies, the vehicle provides a platform for bringing technologies from the laboratory into an integrated flight system at relatively low cost. This allows individual technologies to mature into capabilities that can be incorporated into human exploration missions. The Morpheus vehicle is propelled by a LOX/Methane engine and sized to carry a payload of 1100 lb to the lunar surface. In addition to VTB vehicles, the Project s major elements include ground support systems and an operations facility. Initial testing will demonstrate technologies used to perform autonomous hazard avoidance and precision landing on a lunar or other planetary surface. The Morpheus vehicle successfully performed a set of integrated vehicle test flights including hot-fire and tethered hover tests, leading up to un-tethered free-flights. The initial phase of this development and testing campaign is being conducted on-site at the Johnson Space Center (JSC), with the first fully integrated vehicle firing its engine less than one year after project initiation. Designed, developed, manufactured and operated in-house by engineers at JSC, the Morpheus Project represents an unprecedented departure from recent NASA programs that traditionally require longer, more expensive development lifecycles and testing at remote, dedicated testing facilities. Morpheus testing includes three major types of integrated tests. A hot-fire (HF) is a static vehicle test of the LOX/Methane propulsion system. Tether tests (TT) have the vehicle suspended above the ground using a crane, which allows testing of the propulsion and integrated Guidance, Navigation, and Control (GN&C) in hovering flight without the risk of a vehicle departure or crash. Morpheus free-flights (FF) test the complete Morpheus system without the additional

  13. [Evaluation of carotid stenosis by using carotid ultrasonography].

    PubMed

    Seike, Nahoko; Ito, Michiko; Yasaka, Masahiro

    2010-12-01

    Carotid stenosis is observed in several diseases such as atherosclerosis, moyamoya disease, and aortitis. Carotid stenosis can be assessed using computed tomography (CT), magnetic resonance angiography (MRA), ultrasonography, or cerebral angiography. Carotid ultrasonography is superior to other modalities because it is a noninvasive, repeatable, and easy method that does not involve much cost. The intima-media complex thickness (IMT) can be easily measured using carotid ultrasonography. The incidence of cerebral and cardiovascular events increases with increase in the thickness of the IMT. The percentage of stenosis was expressed using the NASCET, ECST, or area methods. The NASCET criterion of 70% stenosis for performing carotid endarterectomy for symptomatic carotid stenosis corresponded to 85% ECST stenosis, 90% area stenosis, and 200 cm/sec of peak systolic velocity. Carotid ultrasonography provides information on not only carotid stenosis but also unstable plaques such as ulcer, hypoechoic plaque, thin fibrous cap, and mobile plaque. In patients with moyamoya disease, carotid ultrasonography often reveals that the diameter of the internal carotid artery (ICA) is greatly reduced at the proximal portion above the bulbus (resembling a champagne bottle neck) and is less than 50% that of the common carotid artery (champagne bottle neck sign); the diameter of the ICA is smaller than that of the external carotid artery (diameter reversal sign). In patients with aortitis, IMT thickness is frequently observed at the common carotid artery (Macaroni sign) but not at the ICA. PMID:21139180

  14. PROBABILISTIC MODELING FOR ADVANCED HUMAN EXPOSURE ASSESSMENT

    EPA Science Inventory

    Human exposures to environmental pollutants widely vary depending on the emission patterns that result in microenvironmental pollutant concentrations, as well as behavioral factors that determine the extent of an individual's contact with these pollutants. Probabilistic human exp...

  15. Advancing Humanities Studies at Community, Technical, and Junior Colleges.

    ERIC Educational Resources Information Center

    Eisenberg, Diane U.; And Others

    The American Association of Community and Junior Colleges' (AACJC's) two-year Advancing the Humanities Project (AHP) has assisted selected community colleges in promoting the humanities on their campuses. Parts I and II of this report on the AHP present statements by Dale Parnell and Judith Jeffrey Howard about the AACJC's humanities initiatives…

  16. Photoacoustic imaging of carotid artery atherosclerosis

    NASA Astrophysics Data System (ADS)

    Kruizinga, Pieter; van der Steen, Antonius F. W.; de Jong, Nico; Springeling, Geert; Robertus, Jan Lukas; van der Lugt, Aad; van Soest, Gijs

    2014-11-01

    We introduce a method for photoacoustic imaging of the carotid artery, tailored toward detection of lipid-rich atherosclerotic lesions. A common human carotid artery was obtained at autopsy, embedded in a neck mimicking phantom and imaged with a multimodality imaging system using interstitial illumination. Light was delivered through a 1.25-mm-diameter optical probe that can be placed in the pharynx, allowing the carotid artery to be illuminated from within the body. Ultrasound imaging and photoacoustic signal detection is achieved by an external 8-MHz linear array coupled to an ultrasound imaging system. Spectroscopic analysis of photoacoustic images obtained in the wavelength range from 1130 to 1250 nm revealed plaque-specific lipid accumulation in the collagen structure of the artery wall. These spectroscopic findings were confirmed by histology.

  17. Human factors survey of advanced instrumentation and controls

    SciTech Connect

    Carter, R.J.

    1989-01-01

    A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I C. Fifteen potential human factors problems were identified. They include: the need for an advanced I C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I C; and operator acceptance and trust. 11 refs., 1 tab.

  18. Screening for Carotid Artery Stenosis

    MedlinePlus

    ... Task Force learned about the potential benefits and harms of screening for carotid artery stenosis: Health professionals ... blood flow through the arteries. Potential Benefits and Harms of Carotid Artery Stenosis Screening and Treatment The ...

  19. Advancing Usability Evaluation through Human Reliability Analysis

    SciTech Connect

    Ronald L. Boring; David I. Gertman

    2005-07-01

    This paper introduces a novel augmentation to the current heuristic usability evaluation methodology. The SPAR-H human reliability analysis method was developed for categorizing human performance in nuclear power plants. Despite the specialized use of SPAR-H for safety critical scenarios, the method also holds promise for use in commercial off-the-shelf software usability evaluations. The SPAR-H method shares task analysis underpinnings with human-computer interaction, and it can be easily adapted to incorporate usability heuristics as performance shaping factors. By assigning probabilistic modifiers to heuristics, it is possible to arrive at the usability error probability (UEP). This UEP is not a literal probability of error but nonetheless provides a quantitative basis to heuristic evaluation. When combined with a consequence matrix for usability errors, this method affords ready prioritization of usability issues.

  20. [A Novel, Less Invasive Protection Method for Carotid Artery Stenting].

    PubMed

    Ohshima, Tomotaka; Goto, Shunsaku; Yamamoto, Taiki; Imai, Tasuku; Nishizawa, Toshihisa; Shimato, Shinji; Kato, Kyozo

    2016-07-01

    Purpose: We present a novel, less invasive protection method for carotid artery stenting. Case presentation: A 67-year-old man presented with symptomatic severe left carotid artery stenosis. A transfemoral approach was dangerous because of an abdominal aortic aneurysm. A 6Fr Axcelguide Simmonds catheter was inserted into the right brachial artery, and advanced into the left common carotid artery. Next, a 6Fr Optimo 100-cm catheter was coaxially navigated into the left common carotid artery. A PercuSurge GuardWire 300-cm was coaxially navigated into the left external carotid artery. Under flow reversal with the 2 balloons, another PercuSurge GuardWire 300-cm was navigated into the distal left internal carotid artery through the lesion. After both PercuSurge GuardWire balloons were inflated, the 6Fr Optimo was deflated and retrieved using a catheter exchange technique. Then, under distal double-balloon protection, routine stenting was performed. Conclusions: This technique is safer and less invasive than previous methods, especially in cases with difficult femoral access and vulnerable carotid plaque. PMID:27384116

  1. Human factors aspects of advanced instrumentation in the nuclear industry

    SciTech Connect

    Carter, R.J.

    1989-01-01

    An important consideration in regards to the use of advanced instrumentation in the nuclear industry is the interface between the instrumentation system and the human. A survey, oriented towards identifying the human factors aspects of digital instrumentation, was conducted at a number of United States (US) and Canadian nuclear vendors and utilities. Human factors issues, subsumed under the categories of computer-generated displays, controls, organizational support, training, and related topics were identified. 20 refs., 2 tabs.

  2. Advances in Human B19 Erythrovirus Biology▿

    PubMed Central

    Servant-Delmas, Annabelle; Lefrère, Jean-Jacques; Morinet, Frédéric; Pillet, Sylvie

    2010-01-01

    Since its discovery, human parvovirus B19 (B19V), now termed erythrovirus, has been associated with many clinical situations (neurological and myocardium infections, persistent B19V DNAemia) in addition to the prototype clinical manifestations, i.e., erythema infectiosum and erythroblastopenia crisis. In 2002, the use of new molecular tools led to the characterization of three different genotypes of human B19 erythrovirus. Although the genomic organization is conserved, the geographic distribution of the different genotypes varies worldwide, and the nucleotidic divergences can impact the molecular diagnosis of B19 virus infection. The cell cycle of the virus remains partially unresolved; however, recent studies have shed light on the mechanism of cell entry and the interactions of B19V proteins with apoptosis pathways. PMID:20631151

  3. Carotid Artery Disease

    MedlinePlus

    ... and efficacy continues to be studied in several medical centers. This procedure involves the placement of a small flexible tube (catheter) into an artery from the groin. The catheter is then directed to the neck to reach the carotid artery blockage. A balloon pushes open the artery wall and a stent ( ...

  4. Carotid Artery Screening

    MedlinePlus

    ... or radiologist then places the transducer on the skin in various locations, sweeping over the area of interest or angling the sound beam from a different location to better see an area of concern. Doppler sonography and Carotid IMT US are performed using the ...

  5. Coronary atherosclerosis burden is not advanced in patients with β-thalassemia despite premature extracardiac atherosclerosis: a coronary artery calcium score and carotid intima-media thickness study

    PubMed Central

    Hahalis, George; Zacharioglou, Evangelia; Xanthopoulou, Ioanna; Koniari, Ioanna; Kalogeropoulou, Chistina; Tsota, Irene; Rigopoulou, Aspasia; Diamantopoulos, Athanasios; Gkizas, Vasilios; Davlouros, Periklis; Akinosoglou, Karolina; Leopoulou, Marianna; Gogos, Charalampos; Alexopoulos, Dimitrios

    2016-01-01

    Background Thalassemic patients demonstrate an increased rate of extracardiac vascular complications and increased carotid wall intima-media thickness (cIMT), but very low prevalence of coronary artery disease (CAD). We investigated the atheroma burden by assessing the coronary artery calcium (CAC) and cIMT in these patients. Methods We examined 37 patients with β-thalassemia and 150 healthy control volunteers with multi-detector computer tomography (CT) and ultrasonography to determine CAC score and cIMT, respectively. Results Propensity score matching (C-statistic: 0.88; 95% CI: 0.83–0.93) resulted in 27 pairs of patients; severe CAC was observed in 2 (7.4%) and 0 of β-thalassemia patients and healthy volunteers respectively (P = 0.5). Median calcium score was 0 (0–0) in β-thalassemia patients and 0 (0–4) in healthy volunteers (P = 0.8). Median intima-media thickness was higher in β-thalassemia patients compared to control group [0.45 (0.06–0.65) vs. 0.062 (0.054–0.086); P = 0.04]. Conclusions Patients with β–thalassemia in comparison with healthy control subjects exhibit similar CAC score and increased cIMT. Our findings indicate a disparate rate of progression of atherosclerosis between coronary and extracardiac arteries in these patients lending support to the epidemiological evidence. PMID:27168742

  6. Advanced Solid State Lighting for Human Evaluation Project

    NASA Technical Reports Server (NTRS)

    Zeitlin, Nancy; Holbert, Eirik

    2015-01-01

    Lighting intensity and color have a significant impact on human circadian rhythms. Advanced solid state lighting was developed for the Advanced Exploration System (AES) Deep Space Habitat(DSH) concept demonstrator. The latest generation of assemblies using the latest commercially available LED lights were designed for use in the Bigelow Aerospace Environmental Control and Life Support System (ECLSS) simulator and the University of Hawaii's Hawaii Space Exploration Analog and Simulation (Hi-SEAS) habitat. Agreements with both these organizations will allow the government to receive feedback on the lights and lighting algorithms from long term human interaction.

  7. Subject-Specific Fully-Coupled and One-Way Fluid-Structure Interaction Models for Modeling of Carotid Atherosclerotic Plaques in Humans

    PubMed Central

    Tao, Xiaojuan; Gao, Peiyi; Jing, Lina; Lin, Yan; Sui, Binbin

    2015-01-01

    Background Hemodynamics play an important role in the development and progression of carotid atherosclerosis, and may be important in the assessment of plaque vulnerability. The aim of this study was to develop a system to assess the hemodynamics of carotid atherosclerotic plaques using subject-specific fluid-structure interaction (FSI) models based on magnetic resonance imaging (MRI). Material/Methods Models of carotid bifurcations (n=86 with plaques from 52 patients, n=14 normal carotids from 12 participants) were obtained at the Department of Radiology, Beijing Tian Tan Hospital between 2010 and 2013. The maximum von Mises stress, minimum pressure, and flow velocity values were assessed at the most stenotic site in patients, or at the carotid bifurcations in healthy volunteers. Results of one-way FSI were compared with fully-coupled FSI for the plaques of 19 randomly selected models. Results The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05). The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05). Although there were differences in numerical values, both methods were equivalent. The maximum von Mises stress of vulnerable plaques was significantly higher than stable plaques (P<0.001). The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001). Conclusions The hemodynamics of atherosclerotic plaques can be assessed noninvasively using subject-specific models of FSI based on MRI. PMID:26510514

  8. Experimental determination of circumferential properties of fresh carotid artery plaques.

    PubMed

    Lawlor, Michael G; O'Donnell, Michael R; O'Connell, Barry M; Walsh, Michael T

    2011-06-01

    Carotid endarterectomy (CEA) is currently accepted as the gold standard for interventional revascularisation of diseased arteries belonging to the carotid bifurcation. Despite the proven efficacy of CEA, great interest has been generated in carotid angioplasty and stenting (CAS) as an alternative to open surgical therapy. CAS is less invasive compared with CEA, and has the potential to successfully treat lesions close to the aortic arch or distal internal carotid artery (ICA). Following promising results from two recent trials (CREST; Carotid revascularisation endarterectomy versus stenting trial, and ICSS; International carotid stenting study) it is envisaged that there will be a greater uptake in carotid stenting, especially amongst the group who do not qualify for open surgical repair, thus creating pressure to develop computational models that describe a multitude of plaque models in the carotid arteries and their reaction to the deployment of such interventional devices. Pertinent analyses will require fresh human atherosclerotic plaque material characteristics for different disease types. This study analysed atherosclerotic plaque characteristics from 18 patients tested on site, post-surgical revascularisation through endarterectomy, with 4 tissue samples being excluded from tensile testing based on large width-length ratios. According to their mechanical behaviour, atherosclerotic plaques were separated into 3 grades of stiffness. Individual and group material coefficients were then generated analytically using the Yeoh strain energy function. The ultimate tensile strength (UTS) of each sample was also recorded, showing large variation across the 14 atherosclerotic samples tested. Experimental Green strains at rupture varied from 0.299 to 0.588 and the Cauchy stress observed in the experiments was between 0.131 and 0.779 MPa. It is expected that this data may be used in future design optimisation of next generation interventional medical devices for the

  9. Management of Carotid Artery Trauma

    PubMed Central

    Lee, Thomas S.; Ducic, Yadranko; Gordin, Eli; Stroman, David

    2014-01-01

    With increased awareness and liberal screening of trauma patients with identified risk factors, recent case series demonstrate improved early diagnosis of carotid artery trauma before they become problematio. There remains a need for unified screening criteria for both intracranial and extracranial carotid trauma. In the absence of contraindications, antithrombotic agents should be considered in blunt carotid artery injuries, as there is a significant risk of progression of vessel injury with observation alone. Despite CTA being used as a common screening modality, it appears to lack sufficient sensitivity. DSA remains to be the gold standard in screening. Endovascular techniques are becoming more widely accepted as the primary surgical modality in the treatment of blunt extracranial carotid injuries and penetrating/blunt intracranial carotid lessions. Nonetheless, open surgical approaches are still needed for the treatment of penetrating extracranial carotid injuries and in patients with unfavorable lesions for endovascular intervention. PMID:25136406

  10. Human life support for advanced space exploration

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, S. H.

    1997-01-01

    The requirements for a human life support system for long-duration space missions are reviewed. The system design of a controlled ecological life support system is briefly described, followed by a more detailed account of the study of the conceptual design of a Lunar Based CELSS. The latter is to provide a safe, reliable, recycling lunar base life support system based on a hybrid physicochemical/biological representative technology. The most important conclusion reached by this study is that implementation of a completely recycling CELSS approach for a lunar base is not only feasible, but eminently practical. On a cumulative launch mass basis, a 4-person Lunar Base CELSS would pay for itself in approximately 2.6 years relative to a physicochemical air/water recycling system with resupply of food from the Earth. For crew sizes of 30 and 100, the breakeven point would come even sooner, after 2.1 and 1.7 years, respectively, due to the increased mass savings that can be realized with the larger plant growth units. Two other conclusions are particularly important with regard to the orientation of future research and technology development. First, the mass estimates of the Lunar Base CELSS indicate that a primary design objective in implementing this kind of system must be to minimized the mass and power requirement of the food production plant growth units, which greatly surpass those of the other air and water recycling systems. Consequently, substantial research must be directed at identifying ways to produce food more efficiently. On the other hand, detailed studies to identify the best technology options for the other subsystems should not be expected to produce dramatic reductions in either mass or power requirement of a Lunar Base CELSS. The most crucial evaluation criterion must, therefore, be the capability for functional integration of these technologies into the ultimate design of the system. Secondly, this study illustrates that existing or near

  11. Human life support for advanced space exploration.

    PubMed

    Schwartzkopf, S H

    1997-01-01

    The requirements for a human life support system for long-duration space missions are reviewed. The system design of a controlled ecological life support system is briefly described, followed by a more detailed account of the study of the conceptual design of a Lunar Based CELSS. The latter is to provide a safe, reliable, recycling lunar base life support system based on a hybrid physicochemical/biological representative technology. The most important conclusion reached by this study is that implementation of a completely recycling CELSS approach for a lunar base is not only feasible, but eminently practical. On a cumulative launch mass basis, a 4-person Lunar Base CELSS would pay for itself in approximately 2.6 years relative to a physicochemical air/water recycling system with resupply of food from the Earth. For crew sizes of 30 and 100, the breakeven point would come even sooner, after 2.1 and 1.7 years, respectively, due to the increased mass savings that can be realized with the larger plant growth units. Two other conclusions are particularly important with regard to the orientation of future research and technology development. First, the mass estimates of the Lunar Base CELSS indicate that a primary design objective in implementing this kind of system must be to minimized the mass and power requirement of the food production plant growth units, which greatly surpass those of the other air and water recycling systems. Consequently, substantial research must be directed at identifying ways to produce food more efficiently. On the other hand, detailed studies to identify the best technology options for the other subsystems should not be expected to produce dramatic reductions in either mass or power requirement of a Lunar Base CELSS. The most crucial evaluation criterion must, therefore, be the capability for functional integration of these technologies into the ultimate design of the system. Secondly, this study illustrates that existing or near

  12. Human life support for advanced space exploration.

    PubMed

    Schwartzkopf, S H

    1997-01-01

    The requirements for a human life support system for long-duration space missions are reviewed. The system design of a controlled ecological life support system is briefly described, followed by a more detailed account of the study of the conceptual design of a Lunar Based CELSS. The latter is to provide a safe, reliable, recycling lunar base life support system based on a hybrid physicochemical/biological representative technology. The most important conclusion reached by this study is that implementation of a completely recycling CELSS approach for a lunar base is not only feasible, but eminently practical. On a cumulative launch mass basis, a 4-person Lunar Base CELSS would pay for itself in approximately 2.6 years relative to a physicochemical air/water recycling system with resupply of food from the Earth. For crew sizes of 30 and 100, the breakeven point would come even sooner, after 2.1 and 1.7 years, respectively, due to the increased mass savings that can be realized with the larger plant growth units. Two other conclusions are particularly important with regard to the orientation of future research and technology development. First, the mass estimates of the Lunar Base CELSS indicate that a primary design objective in implementing this kind of system must be to minimized the mass and power requirement of the food production plant growth units, which greatly surpass those of the other air and water recycling systems. Consequently, substantial research must be directed at identifying ways to produce food more efficiently. On the other hand, detailed studies to identify the best technology options for the other subsystems should not be expected to produce dramatic reductions in either mass or power requirement of a Lunar Base CELSS. The most crucial evaluation criterion must, therefore, be the capability for functional integration of these technologies into the ultimate design of the system. Secondly, this study illustrates that existing or near

  13. Advanced human-system interface design review guidelines

    SciTech Connect

    O'Hara, J.M.

    1990-01-01

    Advanced, computer-based, human-system interface designs are emerging in nuclear power plant (NPP) control rooms. These developments may have significant implications for plant safety in that they will greatly affect the ways in which operators interact with systems. At present, however, the only guidance available to the US Nuclear Regulatory Commission (NRC) for the review of control room-operator interfaces, NUREG-0700, was written prior to these technological changes and is thus not designed to address them. The objective of the project reported in this paper is to develop an Advanced Control Room Design Review Guideline for use in performing human factors reviews of advanced operator interfaces. This guideline will be implemented, in part, as a portable, computer-based, interactive document for field use. The paper describes the overall guideline development methodology, the present status of the document, and the plans for further guideline testing and development. 21 refs., 3 figs.

  14. Imagining STEM Higher Education Futures: Advancing Human Well-Being

    ERIC Educational Resources Information Center

    Walker, Melanie

    2015-01-01

    The paper explores a conceptual approach to the question of what it means to provide a university education that addresses equity, and encourages the formation of STEM graduates oriented to public-good values and with commitments to making professional contributions to society which will advance human well-being. It considers and rejects…

  15. Cities and Urban Land Use in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Ford, Larry R.

    2000-01-01

    Discusses the cities and urban land use section of the Advanced Placement (AP) human geography course, focusing on the: (1) definitions of urbanism; (2) origin and evolution of cities; (3) functional character of contemporary cities; (4) built environment and social space; and (5) responses to urban growth. (CMK)

  16. Human Ecology and Health Advancement: The Newcastle Experience and Implications.

    ERIC Educational Resources Information Center

    Graham, Jenny; Honari, Morteza

    1992-01-01

    Argues for the necessity of adopting a human ecological framework for the advancement of health. Focusing on the Australian experience, highlights the difficulties in moving beyond the narrow mold of Western Medical Science to a more holistic, quality of life orientation, and suggests that the role of education at all levels of the community is…

  17. Industrialization and Economic Development in Advanced Placement Human Geography.

    ERIC Educational Resources Information Center

    Bailey, Adrian J.

    2000-01-01

    Focuses on the industrialization and economic development section of the Advanced Placement (AP) human geography course, addressing four specific aspects: (1) the character of industrialization; (2) spatial aspects of the rise of industrial economies; (3) contemporary global patterns of industrialization and resource extraction; and (4) impacts of…

  18. Carotid body paraganglioma.

    PubMed

    Manzoor, Tahir; Ahmed, Bashir; Najam, Atif; Ayub, Zeeshan

    2009-08-01

    Carotid body tumours are benign neoplasms. This case report describes two patients with this rare tumour with diagnostic workup and treatment options. The first case was a 36-year-old gentleman who presented with 6 months history of painless swelling on the left side of neck. The second patient was 60-years-old man who presented with slowly growing swelling on the right side of neck for the last 20 years. Both patients had transmitted pulsations over the swelling. On suspicion of a vascular lesion, a contrast enhanced CT scan and Doppler's ultrasound of neck was advised which suggested the diagnosis of a carotid body tumour. Magnetic Resonance Angiography (MRA) confirmed the diagnosis. Excision in collaboration with vascular surgeon was planned for the first case. The second case was subjected to radiation therapy due to the large size of tumour and the patient's age.

  19. Data on TREM-1 activation destabilizing carotid plaques.

    PubMed

    Rao, Velidi H; Rai, Vikrant; Stoupa, Samantha; Subramanian, Saravanan; Agrawal, Devendra K

    2016-09-01

    The data described herein are related to the article entitled "Tumor necrosis factor-α regulates triggering receptor expressed on myeloid cells-1-dependent matrix metalloproteinases in the carotid plaques of symptomatic patients with carotid stenosis" (Rao et al., 2016) [1]. Additional data are provided on the dose-response effect of TNF-α, TREM-1 antibody and recombinant rTREM-1/Fc fusion chimera (TREM-1/FC) on the expression of MMP-1 and MMP-9 in vascular smooth muscle cells (VSMCs) isolated from human carotid endarterectomy tissues. Data are also presented on the distribution of CD86+ M1- and CD206+ M2-macrophages and their co-localization with TREM-1 in symptomatic carotid plaques as visualized by dual immunofluorescence. The interpretation of this data and further extensive insights can be found in Rao et al. (2016) [1]. PMID:27331093

  20. Carotid Artery Stenting versus Endarterectomy

    PubMed Central

    Gahremanpour, Amir; Perin, Emerson C.; Silva, Guilherme

    2012-01-01

    For about 2 decades, investigators have been comparing carotid endarterectomy with carotid artery stenting in regard to their effectiveness and safety in treating carotid artery stenosis. We conducted a systematic review to summarize and appraise the available evidence provided by randomized trials, meta-analyses, and registries comparing the clinical outcomes of the 2 procedures. We searched the MEDLINE, SciVerse Scopus, and Cochrane databases and the bibliographies of pertinent textbooks and articles to identify these studies. The results of clinical trials and, consequently, the meta-analyses of those trials produced conflicting results regarding the comparative effectiveness and safety of carotid endarterectomy and carotid stenting. These conflicting results arose because of differences in patient population, trial design, outcome measures, and variability among centers in the endovascular devices used and in operator skills. Careful appraisal of the trials and meta-analyses, particularly the most recent and largest National Institutes of Healthsponsored trial (the Carotid Revascularization Endarterectomy vs Stenting Trial [CREST]), showed that carotid stenting and endarterectomy were associated with similar rates of death and disabling stroke. Within the 30-day periprocedural period, carotid stenting was associated with higher risks of stroke, especially for patients aged >70 years, whereas carotid endarterectomy was associated with a higher risk of myocardial infarction. The slightly higher cost of stenting compared with endarterectomy was within an acceptable range by cost-effectiveness standards. We conclude that carotid artery stenting is an equivalent alternative to carotid endarterectomy when patient age and anatomy, surgical risk, and operator experience are considered in the choice of treatment approach. PMID:22949763

  1. Advanced automated glass cockpit certification: Being wary of human factors

    NASA Technical Reports Server (NTRS)

    Amalberti, Rene; Wilbaux, Florence

    1994-01-01

    This paper presents some facets of the French experience with human factors in the process of certification of advanced automated cockpits. Three types of difficulties are described: first, the difficulties concerning the hotly debated concept of human error and its non-linear relationship to risk of accident; a typology of errors to be taken into account in the certification process is put forward to respond to this issue. Next, the difficulties connected to the basically gradual and evolving nature of pilot expertise on a given type of aircraft, which contrasts with the immediate and definitive style of certifying systems. The last difficulties to be considered are those related to the goals of certification itself on these new aircraft and the status of findings from human factor analyses (in particular, what should be done with disappointing results, how much can the changes induced by human factors investigation economically affect aircraft design, how many errors do we need to accumulate before we revise the system, what should be remedied when human factor problems are discovered at the certification stage: the machine? pilot training? the rules? or everything?). The growth of advanced-automated glass cockpits has forced the international aeronautical community to pay more attention to human factors during the design phase, the certification phase and pilot training. The recent creation of a human factor desk at the DGAC-SFACT (Official French services) is a direct consequence of this. The paper is divided into three parts. Part one debates human error and its relationship with system design and accident risk. Part two describes difficulties connected to the basically gradual and evolving nature of pilot expertise on a given type of aircraft, which contrasts with the immediate and definitive style of certifying systems. Part three focuses on concrete outcomes of human factors for certification purposes.

  2. Technical advances and pitfalls on the way to human cloning.

    PubMed

    Mollard, Richard; Denham, Mark; Trounson, Alan

    2002-03-01

    There exists a widespread consensus that the cloning of human beings to term would be detrimental to both the mother and child and of little value to society. However, the ambition of a few organisations and the recent advances in cellular and molecular technologies that led to the cloning of Dolly the sheep, for example, have meant that such a procedure will be possible if not illegal in the near future. The science associated with the cloning technologies practiced in other mammalian species reported to date provide important advances in our understanding of how cells function during early developmental processes and commit themselves to specific developmental pathways. However, many technological insufficiencies remain. Both technological advances and several of the associated insufficiencies are outlined in this review.

  3. Technical advances and pitfalls on the way to human cloning.

    PubMed

    Mollard, Richard; Denham, Mark; Trounson, Alan

    2002-03-01

    There exists a widespread consensus that the cloning of human beings to term would be detrimental to both the mother and child and of little value to society. However, the ambition of a few organisations and the recent advances in cellular and molecular technologies that led to the cloning of Dolly the sheep, for example, have meant that such a procedure will be possible if not illegal in the near future. The science associated with the cloning technologies practiced in other mammalian species reported to date provide important advances in our understanding of how cells function during early developmental processes and commit themselves to specific developmental pathways. However, many technological insufficiencies remain. Both technological advances and several of the associated insufficiencies are outlined in this review. PMID:11963651

  4. Carotid chemoreceptor development in mice.

    PubMed

    Shirahata, Machiko; Kostuk, Eric W; Pichard, Luis E

    2013-01-01

    Mice are the most suitable species for understanding genetic aspects of postnatal developments of the carotid body due to the availability of many inbred strains and knockout mice. Our study has shown that the carotid body grows differentially in different mouse strains, indicating the involvement of genes. However, the small size hampers investigating functional development of the carotid body. Hypoxic and/or hyperoxic ventilatory responses have been investigated in newborn mice, but these responses are indirect assessment of the carotid body function. Therefore, we need to develop techniques of measuring carotid chemoreceptor neural activity from young mice. Many studies have taken advantage of the knockout mice to understand chemoreceptor function of the carotid body, but they are not always suitable for addressing postnatal development of the carotid body due to lethality during perinatal periods. Various inbred strains with well-designed experiments will provide useful information regarding genetic mechanisms of the postnatal carotid chemoreceptor development. Also, targeted gene deletion is a critical approach.

  5. Carotid revascularization: risks and benefits

    PubMed Central

    O’Brien, Marlene; Chandra, Ankur

    2014-01-01

    Despite a decline during the recent decades in stroke-related death, the incidence of stroke has remained unchanged or slightly increased, and extracranial carotid artery stenosis is implicated in 20%–30% of all strokes. Medical therapy and risk factor modification are first-line therapies for all patients with carotid occlusive disease. Evidence for the treatment of patients with symptomatic carotid stenosis greater than 70% with either carotid artery stenting (CAS) or carotid endarterectomy (CEA) is compelling, and several trials have demonstrated a benefit to carotid revascularization in the symptomatic patient population. Asymptomatic carotid stenosis is more controversial, with the largest trials only demonstrating a 1% per year risk stroke reduction with CEA. Although there are sufficient data to advocate for aggressive medical therapy as the primary mode of treatment for asymptomatic carotid stenosis, there are also data to suggest that certain patient populations will benefit from a stroke risk reduction with carotid revascularization. In the United States, consensus and practice guidelines dictate that CEA is reasonable in patients with high-grade asymptomatic stenosis, a reasonable life expectancy, and perioperative risk of less than 3%. Regarding CAS versus CEA, the best-available evidence demonstrates no difference between the two procedures in early perioperative stroke, myocardial infarction, or death, and no difference in 4-year ipsilateral stroke risk. However, because of the higher perioperative risks of stroke in patients undergoing CAS, particularly in symptomatic, female, or elderly patients, it is difficult to recommend CAS over CEA except in populations with prohibitive cardiac risk, previous carotid surgery, or prior neck radiation. Current treatment paradigms are based on identifying the magnitude of perioperative risk in patient subsets and on using predictive factors to stratify patients with high-risk asymptomatic stenosis. PMID

  6. Carotid chemoreceptor "resetting" revisited.

    PubMed

    Carroll, John L; Kim, Insook

    2013-01-01

    Carotid body (CB) chemoreceptors transduce low arterial O(2) tension into increased action potential activity on the carotid sinus nerves, which contributes to resting ventilatory drive, increased ventilatory drive in response to hypoxia, arousal responses to hypoxia during sleep, upper airway muscle activity, blood pressure control and sympathetic tone. Their sensitivity to O(2) is low in the newborn and increases during the days or weeks after birth to reach adult levels. This postnatal functional maturation of the CB O(2) response has been termed "resetting" and it occurs in every mammalian species studied to date. The O(2) environment appears to play a key role; the fetus develops in a low O(2) environment throughout gestation and initiation of CB "resetting" after birth is modulated by the large increase in arterial oxygen tension occurring at birth. Although numerous studies have reported age-related changes in various components of the O(2) transduction cascade, how the O(2) environment shapes normal CB prenatal development and postnatal "resetting" remains unknown. Viewing CB "resetting" as environment-driven (developmental) phenotypic plasticity raises important mechanistic questions that have received little attention. This review examines what is known (and not known) about mechanisms of CB functional maturation, with a focus on the role of the O(2) environment.

  7. Increased carotid intima-media thickness and reduced distensibility in human class III obesity: independent and differential influences of adiposity and blood pressure on the vasculature.

    PubMed

    Moore, Xiao L; Michell, Danielle; Lee, Sabrina; Skilton, Michael R; Nair, Rajesh; Dixon, John B; Dart, Anthony M; Chin-Dusting, Jaye

    2013-01-01

    Carotid intima-media-thickness (cIMT) and carotid distensibility (distensibility), structural and functional properties of carotid arteries respectively, are early markers, as well as strong predictors of cardiovascular disease (CVD). The characteristic of these two parameters in individuals with BMI>40.0 kg/m(2) (Class III obesity), however, are largely unknown. The present study was designed to document cIMT and distensibility in this population and to relate these to other factors with established association with CVD in obesity. The study included 96 subjects (65 with BMI>40.0 kg/m(2) and 31, age- and gender-matched, with BMI of 18.5 to 30.0 kg/m(2)). cIMT and distensibility were measured by non-invasive high resolution ultrasonography, circulatory CD133(+)/KDR(+) angiogenic cells and endothelial microparticles (EMP) by flow cytometry, and plasma levels of adipokines, growth factors and cytokines by Luminex immunoassay kits. The study results demonstrated increased cIMT (0.62±0.11 mm vs. 0.54±0.08 mm, P = 0.0002) and reduced distensibility (22.52±10.79 10(-3)kpa(-1)vs. 29.91±12.37 10(-3)kpa(-1), P<0.05) in individuals with BMI>40.0 kg/m(2). Both cIMT and distensibility were significantly associated with traditional CVD risk factors, adiposity/adipokines and inflammatory markers but had no association with circulating angiogenic cells. We also demonstrated, for the first time, elevated plasma EMP levels in individuals with BMI>40.0 kg/m(2). In conclusion, cIMT is increased and distensibility reduced in Class III obesity with the changes predominantly related to conventional CVD risk factors present in this condition, demonstrating that both cIMT and distensibility remain as CVD markers in Class III obesity. PMID:23342053

  8. Increased Carotid Intima-Media Thickness and Reduced Distensibility in Human Class III Obesity: Independent and Differential Influences of Adiposity and Blood Pressure on the Vasculature

    PubMed Central

    Moore, Xiao L.; Michell, Danielle; Lee, Sabrina; Skilton, Michael R.; Nair, Rajesh; Dixon, John B.; Dart, Anthony M.; Chin-Dusting, Jaye

    2013-01-01

    Carotid intima-media-thickness (cIMT) and carotid distensibility (distensibility), structural and functional properties of carotid arteries respectively, are early markers, as well as strong predictors of cardiovascular disease (CVD). The characteristic of these two parameters in individuals with BMI>40.0 kg/m2 (Class III obesity), however, are largely unknown. The present study was designed to document cIMT and distensibility in this population and to relate these to other factors with established association with CVD in obesity. The study included 96 subjects (65 with BMI>40.0 kg/m2 and 31, age- and gender-matched, with BMI of 18.5 to 30.0 kg/m2). cIMT and distensibility were measured by non-invasive high resolution ultrasonography, circulatory CD133+/KDR+ angiogenic cells and endothelial microparticles (EMP) by flow cytometry, and plasma levels of adipokines, growth factors and cytokines by Luminex immunoassay kits. The study results demonstrated increased cIMT (0.62±0.11 mm vs. 0.54±0.08 mm, P = 0.0002) and reduced distensibility (22.52±10.79 10−3kpa−1 vs. 29.91±12.37 10−3kpa−1, P<0.05) in individuals with BMI>40.0 kg/m2. Both cIMT and distensibility were significantly associated with traditional CVD risk factors, adiposity/adipokines and inflammatory markers but had no association with circulating angiogenic cells. We also demonstrated, for the first time, elevated plasma EMP levels in individuals with BMI>40.0 kg/m2. In conclusion, cIMT is increased and distensibility reduced in Class III obesity with the changes predominantly related to conventional CVD risk factors present in this condition, demonstrating that both cIMT and distensibility remain as CVD markers in Class III obesity. PMID:23342053

  9. Increased carotid intima-media thickness and reduced distensibility in human class III obesity: independent and differential influences of adiposity and blood pressure on the vasculature.

    PubMed

    Moore, Xiao L; Michell, Danielle; Lee, Sabrina; Skilton, Michael R; Nair, Rajesh; Dixon, John B; Dart, Anthony M; Chin-Dusting, Jaye

    2013-01-01

    Carotid intima-media-thickness (cIMT) and carotid distensibility (distensibility), structural and functional properties of carotid arteries respectively, are early markers, as well as strong predictors of cardiovascular disease (CVD). The characteristic of these two parameters in individuals with BMI>40.0 kg/m(2) (Class III obesity), however, are largely unknown. The present study was designed to document cIMT and distensibility in this population and to relate these to other factors with established association with CVD in obesity. The study included 96 subjects (65 with BMI>40.0 kg/m(2) and 31, age- and gender-matched, with BMI of 18.5 to 30.0 kg/m(2)). cIMT and distensibility were measured by non-invasive high resolution ultrasonography, circulatory CD133(+)/KDR(+) angiogenic cells and endothelial microparticles (EMP) by flow cytometry, and plasma levels of adipokines, growth factors and cytokines by Luminex immunoassay kits. The study results demonstrated increased cIMT (0.62±0.11 mm vs. 0.54±0.08 mm, P = 0.0002) and reduced distensibility (22.52±10.79 10(-3)kpa(-1)vs. 29.91±12.37 10(-3)kpa(-1), P<0.05) in individuals with BMI>40.0 kg/m(2). Both cIMT and distensibility were significantly associated with traditional CVD risk factors, adiposity/adipokines and inflammatory markers but had no association with circulating angiogenic cells. We also demonstrated, for the first time, elevated plasma EMP levels in individuals with BMI>40.0 kg/m(2). In conclusion, cIMT is increased and distensibility reduced in Class III obesity with the changes predominantly related to conventional CVD risk factors present in this condition, demonstrating that both cIMT and distensibility remain as CVD markers in Class III obesity.

  10. Carotid Disease Management: Surgery, Stenting, or Medication.

    PubMed

    Khandelwal, Priyank; Chaturvedi, Seemant

    2015-09-01

    Internal carotid artery stenosis accounts for about 7-10 % of ischemic strokes. Conventional risk factors such as aging, hypertension, diabetes mellitus, and smoking increase the risk for carotid atherosclerosis. All patients with carotid stenosis should receive aggressive medical therapy. Carotid revascularization with either endarterectomy or stenting can benefit select patients with severe stenosis. New clinical trials will examine the contemporary role of carotid revascularization relative to optimal medical therapy.

  11. Contemporary carotid imaging: from degree of stenosis to plaque vulnerability.

    PubMed

    Brinjikji, Waleed; Huston, John; Rabinstein, Alejandro A; Kim, Gyeong-Moon; Lerman, Amir; Lanzino, Giuseppe

    2016-01-01

    Carotid artery stenosis is a well-established risk factor of ischemic stroke, contributing to up to 10%-20% of strokes or transient ischemic attacks. Many clinical trials over the last 20 years have used measurements of carotid artery stenosis as a means to risk stratify patients. However, with improvements in vascular imaging techniques such as CT angiography and MR angiography, ultrasonography, and PET/CT, it is now possible to risk stratify patients, not just on the degree of carotid artery stenosis but also on how vulnerable the plaque is to rupture, resulting in ischemic stroke. These imaging techniques are ushering in an emerging paradigm shift that allows for risk stratifications based on the presence of imaging features such as intraplaque hemorrhage (IPH), plaque ulceration, plaque neovascularity, fibrous cap thickness, and presence of a lipid-rich necrotic core (LRNC). It is important for the neurosurgeon to be aware of these new imaging techniques that allow for improved patient risk stratification and outcomes. For example, a patient with a low-grade stenosis but an ulcerated plaque may benefit more from a revascularization procedure than a patient with a stable 70% asymptomatic stenosis with a thick fibrous cap. This review summarizes the current state-of-the-art advances in carotid plaque imaging. Currently, MRI is the gold standard in carotid plaque imaging, with its high resolution and high sensitivity for identifying IPH, ulceration, LRNC, and inflammation. However, MRI is limited due to time constraints. CT also allows for high-resolution imaging and can accurately detect ulceration and calcification, but cannot reliably differentiate LRNC from IPH. PET/CT is an effective technique to identify active inflammation within the plaque, but it does not allow for assessment of anatomy, ulceration, IPH, or LRNC. Ultrasonography, with the aid of contrast enhancement, is a cost-effective technique to assess plaque morphology and characteristics, but it is

  12. A Cryptochrome 2 mutation yields advanced sleep phase in humans.

    PubMed

    Hirano, Arisa; Shi, Guangsen; Jones, Christopher R; Lipzen, Anna; Pennacchio, Len A; Xu, Ying; Hallows, William C; McMahon, Thomas; Yamazaki, Maya; Ptáček, Louis J; Fu, Ying-Hui

    2016-01-01

    Familial Advanced Sleep Phase (FASP) is a heritable human sleep phenotype characterized by very early sleep and wake times. We identified a missense mutation in the human Cryptochrome 2 (CRY2) gene that co-segregates with FASP in one family. The mutation leads to replacement of an alanine residue at position 260 with a threonine (A260T). In mice, the CRY2 mutation causes a shortened circadian period and reduced phase-shift to early-night light pulse associated with phase-advanced behavioral rhythms in the light-dark cycle. The A260T mutation is located in the phosphate loop of the flavin adenine dinucleotide (FAD) binding domain of CRY2. The mutation alters the conformation of CRY2, increasing its accessibility and affinity for FBXL3 (an E3 ubiquitin ligase), thus promoting its degradation. These results demonstrate that CRY2 stability controlled by FBXL3 plays a key role in the regulation of human sleep wake behavior. PMID:27529127

  13. Advances in culture and manipulation of human pluripotent stem cells.

    PubMed

    Qian, X; Villa-Diaz, L G; Krebsbach, P H

    2013-11-01

    Recent advances in the understanding of pluripotent stem cell biology and emerging technologies to reprogram somatic cells to a stem cell-like state are helping bring stem cell therapies for a range of human disorders closer to clinical reality. Human pluripotent stem cells (hPSCs) have become a promising resource for regenerative medicine and research into early development because these cells are able to self-renew indefinitely and are capable of differentiation into specialized cell types of all 3 germ layers and trophoectoderm. Human PSCs include embryonic stem cells (hESCs) derived from the inner cell mass of blastocyst-stage embryos and induced pluripotent stem cells (hiPSCs) generated via the reprogramming of somatic cells by the overexpression of key transcription factors. The application of hiPSCs and the finding that somatic cells can be directly reprogrammed into different cell types will likely have a significant impact on regenerative medicine. However, a major limitation for successful therapeutic application of hPSCs and their derivatives is the potential xenogeneic contamination and instability of current culture conditions. This review summarizes recent advances in hPSC culture and methods to induce controlled lineage differentiation through regulation of cell-signaling pathways and manipulation of gene expression as well as new trends in direct reprogramming of somatic cells.

  14. Recent advances in research on climate and human conflict

    NASA Astrophysics Data System (ADS)

    Hsiang, S. M.

    2014-12-01

    A rapidly growing body of empirical, quantitative research examines whether rates of human conflict can be systematically altered by climatic changes. We discuss recent advances in this field, including Bayesian meta-analyses of the effect of temperature and rainfall on current and future large-scale conflicts, the impact of climate variables on gang violence and suicides in Mexico, and probabilistic projections of personal violence and property crime in the United States under RCP scenarios. Criticisms of this research field will also be explained and addressed.

  15. NASA's Advanced Life Support Systems Human-Rated Test Facility

    NASA Technical Reports Server (NTRS)

    Henninger, D. L.; Tri, T. O.; Packham, N. J.

    1996-01-01

    Future NASA missions to explore the solar system will be long-duration missions, requiring human life support systems which must operate with very high reliability over long periods of time. Such systems must be highly regenerative, requiring minimum resupply, to enable the crews to be largely self-sufficient. These regenerative life support systems will use a combination of higher plants, microorganisms, and physicochemical processes to recycle air and water, produce food, and process wastes. A key step in the development of these systems is establishment of a human-rated test facility specifically tailored to evaluation of closed, regenerative life supports systems--one in which long-duration, large-scale testing involving human test crews can be performed. Construction of such a facility, the Advanced Life Support Program's (ALS) Human-Rated Test Facility (HRTF), has begun at NASA's Johnson Space Center, and definition of systems and development of initial outfitting concepts for the facility are underway. This paper will provide an overview of the HRTF project plan, an explanation of baseline configurations, and descriptive illustrations of facility outfitting concepts.

  16. NASA's Advanced Life Support Systems Human-Rated Test Facility.

    PubMed

    Henninger, D L; Tri, T O; Packham, N J

    1996-01-01

    Future NASA missions to explore the solar system will be long-duration missions, requiring human life support systems which must operate with very high reliability over long periods of time. Such systems must be highly regenerative, requiring minimum resupply, to enable the crews to be largely self-sufficient. These regenerative life support systems will use a combination of higher plants, microorganisms, and physicochemical processes to recycle air and water, produce food, and process wastes. A key step in the development of these systems is establishment of a human-rated test facility specifically tailored to evaluation of closed, regenerative life supports systems--one in which long-duration, large-scale testing involving human test crews can be performed. Construction of such a facility, the Advanced Life Support Program's (ALS) Human-Rated Test Facility (HRTF), has begun at NASA's Johnson Space Center, and definition of systems and development of initial outfitting concepts for the facility are underway. This paper will provide an overview of the HRTF project plan, an explanation of baseline configurations, and descriptive illustrations of facility outfitting concepts.

  17. Does human cognition allow Human Factors (HF) certification of advanced aircrew systems?

    NASA Technical Reports Server (NTRS)

    Macleod, Iain S.; Taylor, Robert M.

    1994-01-01

    This paper has examined the requirements of HF specification and certification within advanced or complex aircrew systems. It suggests reasons for current inadequacies in the use of HF in the design process, giving some examples in support, and suggesting an avenue towards the improvement of the HF certification process. The importance of human cognition to the operation and performance of advanced aircrew systems has been stressed. Many of the shortfalls of advanced aircrew systems must be attributed to over automated designs that show little consideration on either the mental limits or the cognitive capabilities of the human system component. Traditional approaches to system design and HF certification are set within an over physicalistic foundation. Also, traditionally it was assumed that physicalistic system functions could be attributed to either the human or the machine on a one to one basis. Moreover, any problems associated with the parallel needs, or promoting human understanding alongside system operation and direction, were generally equated in reality by the natural flexibility and adaptability of human skills. The consideration of the human component of a complex system is seen as being primarily based on manifestations of human behavior to the almost total exclusion of any appreciation of unobservable human mental and cognitive processes. The argument of this paper is that the considered functionality of any complex human-machine system must contain functions that are purely human and purely cognitive. Human-machine system reliability ultimately depends on human reliability and dependability and, therefore, on the form and frequency of cognitive processes that have to be conducted to support system performance. The greater the demand placed by an advanced aircraft system on the human component's basic knowledge processes or cognition, rather than on skill, the more insiduous the effects the human may have on that system. This paper discusses one

  18. Indium-111-labeled platelet scintigraphy in carotid atherosclerosis

    SciTech Connect

    Minar, E.; Ehringer, H.; Dudczak, R.; Schoefl, R.J.; Jung, M.; Koppensteiner, R.; Ahmadi, R.; Kretschmer, G.

    1989-01-01

    We evaluated platelet accumulation in carotid arteries by means of a dual-radiotracer method, using indium-111-labeled platelets and technetium-99m-labeled human serum albumin, in 123 patients (92 men, 31 women; median age 60 years). Sixty patients had symptoms of transient ischemic carotid artery disease, and 63 patients with peripheral arterial occlusive disease served as controls. Antiplatelet treatment with acetylsalicylic acid was taken by 53 of the 123 patients. In 36 of the 60 symptomatic patients, platelet scintigraphy was repeated 3-4 days after carotid endarterectomy. Comparison of different scintigraphic parameters (platelet accumulation index and percent of the injected dose of labeled platelets at the carotid bifurcation) showed no significant differences between symptomatic and asymptomatic patients, and the severity of stenosis and the presence of plaque ulceration also had no influence on the parameters. There was no difference between patients with a short (less than 4 weeks) or long (greater than 4 weeks) interval from the last transient ischemic attack to scintigraphy and no difference between patients with or without antiplatelet treatment. Classifying the patients according to plaque morphology judged by high-resolution real-time ultrasonography also demonstrated no differences. No significant correlation was found between any scintigraphic parameter and other platelet function parameters such as platelet survival time, platelet turnover rate, and concentration of platelet-specific proteins. Quantification of platelet deposition after carotid endarterectomy in 36 patients demonstrated a significant increase of the median platelet accumulation index and the percent injected dose index.

  19. Consciousness in humans and non-human animals: recent advances and future directions

    PubMed Central

    Boly, Melanie; Seth, Anil K.; Wilke, Melanie; Ingmundson, Paul; Baars, Bernard; Laureys, Steven; Edelman, David B.; Tsuchiya, Naotsugu

    2013-01-01

    This joint article reflects the authors' personal views regarding noteworthy advances in the neuroscience of consciousness in the last 10 years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical, and conceptual insights. These include the evidence for the importance of fronto-parietal connectivity and of “top-down” processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological enhancements. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation. PMID:24198791

  20. How Is Carotid Artery Disease Treated?

    MedlinePlus

    ... Links Related Topics Atherosclerosis Carotid Endarterectomy Carotid Ultrasound Stents Stroke Send a link to NHLBI to someone ... outward against the wall of the artery. A stent (a small mesh tube) is then put in ...

  1. Developing Advanced Human Support Technologies for Planetary Exploration Missions

    NASA Technical Reports Server (NTRS)

    Berdich, Debra P.; Campbell, Paul D.; Jernigan, J. Mark

    2004-01-01

    The United States Vision for Space Exploration calls for sending robots and humans to explore the Earth's moon, the planet Mars, and beyond. The National Aeronautics and Space Administration (NASA) is developing a set of design reference missions that will provide further detail to these plans. Lunar missions are expected to provide a stepping stone, through operational research and evaluation, in developing the knowledge base necessary to send crews on long duration missions to Mars and other distant destinations. The NASA Exploration Systems Directorate (ExSD), in its program of bioastronautics research, manages the development of technologies that maintain human life, health, and performance in space. Using a system engineering process and risk management methods, ExSD's Human Support Systems (HSS) Program selects and performs research and technology development in several critical areas and transfers the results of its efforts to NASA exploration mission/systems development programs in the form of developed technologies and new knowledge about the capabilities and constraints of systems required to support human existence beyond Low Earth Orbit. HSS efforts include the areas of advanced environmental monitoring and control, extravehicular activity, food technologies, life support systems, space human factors engineering, and systems integration of all these elements. The HSS Program provides a structured set of deliverable products to meet the needs of exploration programs. These products reduce the gaps that exist in our knowledge of and capabilities for human support for long duration, remote space missions. They also reduce the performance gap between the efficiency of current space systems and the greater efficiency that must be achieved to make human planetary exploration missions economically and logistically feasible. In conducting this research and technology development program, it is necessary for HSS technologists and program managers to develop a

  2. Human umbilical cord blood cells and diabetes mellitus: recent advances.

    PubMed

    Reddi, Alluru S; Kothari, Neil; Kuppasani, Kishore; Ende, Norman

    2015-01-01

    Stem cell therapy for patients with diabetes is an area of great interest to both scientists and clinicians. Human umbilical cord blood cells (HUCBCs) are being increasingly used as a source of stem cells for cell-based therapy for diabetes because these cells can differentiate into pancreatic islet β-cells. Administration of HUCBCs has been shown to lower blood glucose levels in diabetic animal models. The use of autologous HUCBC transfusion in type 1 diabetic children has not shown any benefit. However, "Stem Cell Educator" therapy has shown promise in long term lowering of blood glucose levels in both type 1 and type 2 diabetic patients. In this review, we will briefly discuss recent advances in HUCBC therapy in the treatment of diabetes and some of its complications.

  3. Advanced Plasma Propulsion for Human Missions to Jupiter

    NASA Technical Reports Server (NTRS)

    Donahue, Benjamin B.; Pearson, J. Boise

    1999-01-01

    This paper will briefly identify a promising fusion plasma power source, which when coupled with a promising electric thruster technology would provide for an efficient interplanetary transfer craft suitable to a 4 year round trip mission to the Jovian system. An advanced, nearly radiation free Inertial Electrostatic Confinement scheme for containing fusion plasma was judged as offering potential for delivering the performance and operational benefits needed for such high energy human expedition missions, without requiring heavy superconducting magnets for containment of the fusion plasma. Once the Jovian transfer stage has matched the heliocentric velocity of Jupiter, the energy requirements for excursions to its outer satellites (Callisto, Ganymede and Europa) by smaller excursion craft are not prohibitive. The overall propulsion, power and thruster system is briefly described and a preliminary vehicle mass statement is presented.

  4. Zebrafish Models of Human Leukemia: Technological Advances and Mechanistic Insights.

    PubMed

    Harrison, Nicholas R; Laroche, Fabrice J F; Gutierrez, Alejandro; Feng, Hui

    2016-01-01

    Insights concerning leukemic pathophysiology have been acquired in various animal models and further efforts to understand the mechanisms underlying leukemic treatment resistance and disease relapse promise to improve therapeutic strategies. The zebrafish (Danio rerio) is a vertebrate organism with a conserved hematopoietic program and unique experimental strengths suiting it for the investigation of human leukemia. Recent technological advances in zebrafish research including efficient transgenesis, precise genome editing, and straightforward transplantation techniques have led to the generation of a number of leukemia models. The transparency of the zebrafish when coupled with improved lineage-tracing and imaging techniques has revealed exquisite details of leukemic initiation, progression, and regression. With these advantages, the zebrafish represents a unique experimental system for leukemic research and additionally, advances in zebrafish-based high-throughput drug screening promise to hasten the discovery of novel leukemia therapeutics. To date, investigators have accumulated knowledge of the genetic underpinnings critical to leukemic transformation and treatment resistance and without doubt, zebrafish are rapidly expanding our understanding of disease mechanisms and helping to shape therapeutic strategies for improved outcomes in leukemic patients.

  5. Zebrafish Models of Human Leukemia: Technological Advances and Mechanistic Insights

    PubMed Central

    Harrison, Nicholas R.; Laroche, Fabrice J.F.; Gutierrez, Alejandro

    2016-01-01

    Insights concerning leukemic pathophysiology have been acquired in various animal models and further efforts to understand the mechanisms underlying leukemic treatment resistance and disease relapse promise to improve therapeutic strategies. The zebrafish (Danio rerio) is a vertebrate organism with a conserved hematopoietic program and unique experimental strengths suiting it for the investigation of human leukemia. Recent technological advances in zebrafish research including efficient transgenesis, precise genome editing, and straightforward transplantation techniques have led to the generation of a number of leukemia models. The transparency of the zebrafish when coupled with improved lineage-tracing and imaging techniques has revealed exquisite details of leukemic initiation, progression, and regression. With these advantages, the zebrafish represents a unique experimental system for leukemic research and additionally, advances in zebrafish-based high-throughput drug screening promise to hasten the discovery of novel leukemia therapeutics. To date, investigators have accumulated knowledge of the genetic underpinnings critical to leukemic transformation and treatment resistance and without doubt, zebrafish are rapidly expanding our understanding of disease mechanisms and helping to shape therapeutic strategies for improved outcomes in leukemic patients. PMID:27165361

  6. Zebrafish Models of Human Leukemia: Technological Advances and Mechanistic Insights.

    PubMed

    Harrison, Nicholas R; Laroche, Fabrice J F; Gutierrez, Alejandro; Feng, Hui

    2016-01-01

    Insights concerning leukemic pathophysiology have been acquired in various animal models and further efforts to understand the mechanisms underlying leukemic treatment resistance and disease relapse promise to improve therapeutic strategies. The zebrafish (Danio rerio) is a vertebrate organism with a conserved hematopoietic program and unique experimental strengths suiting it for the investigation of human leukemia. Recent technological advances in zebrafish research including efficient transgenesis, precise genome editing, and straightforward transplantation techniques have led to the generation of a number of leukemia models. The transparency of the zebrafish when coupled with improved lineage-tracing and imaging techniques has revealed exquisite details of leukemic initiation, progression, and regression. With these advantages, the zebrafish represents a unique experimental system for leukemic research and additionally, advances in zebrafish-based high-throughput drug screening promise to hasten the discovery of novel leukemia therapeutics. To date, investigators have accumulated knowledge of the genetic underpinnings critical to leukemic transformation and treatment resistance and without doubt, zebrafish are rapidly expanding our understanding of disease mechanisms and helping to shape therapeutic strategies for improved outcomes in leukemic patients. PMID:27165361

  7. Multimodality Imaging of Carotid Stenosis

    PubMed Central

    Adla, Theodor; Adlova, Radka

    2015-01-01

    Four diagnostic modalities are used to image the following internal carotid artery: digital subtraction angiography (DSA), duplex ultrasound (DUS), computed tomography angiography (CTA), and magnetic resonance angiography (MRA). The aim of this article is to describe the potentials of these techniques and to discuss their advantages and disadvantages. Invasive DSA is still considered the gold standard and is an indivisible part of the carotid stenting procedure. DUS is an inexpensive but operator-dependent tool with limited visibility of the carotid artery course. Conversely, CTA and MRA allow assessment of the carotid artery from the aortic arch to intracranial parts. The disadvantages of CTA are radiation and iodine contrast medium administration. MRA is without radiation but contrast-enhanced MRA is more accurate than noncontrast MRA. The choice of methods depends on the clinical indications and the availability of methods in individual centers. However, the general approach to patient with suspected carotid artery stenosis is to first perform DUS and then other noninvasive methods such as CTA, MRA, or transcranial Doppler US. PMID:26417185

  8. Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA)

    NASA Technical Reports Server (NTRS)

    Banker, Brian F.; Robinson, Travis

    2016-01-01

    The proposed paper will cover ongoing effort named HESTIA (Human Exploration Spacecraft Testbed for Integration and Advancement), led at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) to promote a cross-subsystem approach to developing Mars-enabling technologies with the ultimate goal of integrated system optimization. HESTIA also aims to develop the infrastructure required to rapidly test these highly integrated systems at a low cost. The initial focus is on the common fluids architecture required to enable human exploration of mars, specifically between life support and in-situ resource utilization (ISRU) subsystems. An overview of the advancements in both integrated technologies, in infrastructure, in simulation, and in modeling capabilities will be presented, as well as the results and findings of integrated testing,. Due to the enormous mass gear-ratio required for human exploration beyond low-earth orbit, (for every 1 kg of payload landed on Mars, 226 kg will be required on Earth), minimization of surface hardware and commodities is paramount. Hardware requirements can be minimized by reduction of equipment performing similar functions though for different subsystems. If hardware could be developed which meets the requirements of both life support and ISRU it could result in the reduction of primary hardware and/or reduction in spares. Minimization of commodities to the surface of mars can be achieved through the creation of higher efficiency systems producing little to no undesired waste, such as a closed-loop life support subsystem. Where complete efficiency is impossible or impractical, makeup commodities could be manufactured via ISRU. Although, utilization of ISRU products (oxygen and water) for crew consumption holds great promise of reducing demands on life support hardware, there exist concerns as to the purity and transportation of commodities. To date, ISRU has been focused on production rates and purities for

  9. Carotid bruits as predictor for carotid stenoses detected by ultrasonography: an observational study

    PubMed Central

    Johansson, Elias P; Wester, Per

    2008-01-01

    Background Carotid surgery in asymptomatic subjects with carotid stenosis is effective to prevent ischemic stroke. There is, however, uncertainty how to find such persons at risk, because mass screening with carotid artery ultrasonography (US) is not cost-effective. Signs of carotid bruits corresponding to the carotid arteries may serve as a tool to select subjects for further investigation. This study is thus aimed at determining the usefulness of carotid bruits in the screening of carotid stenoses. Methods 1555 consecutive carotid ultrasonography investigations from 1486 cases done between January 2004 and March 2006 at Norrlands University Hospital, Sweden, were examined. 356 subjects, medium age 69 (27–88) years, had a significant (≥ 50%) US-verified carotid stenosis uni- or bilaterally, 291 had been examined for signs of carotid bruits. The likelihood ratios for carotid bruits to predict US-verified carotid stenoses were calculated and expressed as likelihood percentages. Results Thirty-one out of 100 persons (31%) with carotid bruit as an indication to perform carotid US had a significant (≥ 50%) carotid stenosis. 281 of the 356 (79%) cases with significant carotid stenoses were found among patients with cerebrovascular disease (CVD). 145 of 226 (64%) CVD patients with a significant carotid stenosis had a carotid bruit. In patients with 50–99% carotid stenoses carotid bruits had an accuracy of 75% (436/582), a sensitivity of 71% (236/334), a specificity of 81% (200/248), a positive likelihood ratio at 3.65 and a negative likelihood at 0.36. Patients with 70–99% stenoses had the highest sensitivity at 77% (183/238). In patients with 100% carotid stenoses, carotid bruits had a sensitivity of 26% (15/57) and a specificity of 49% (256/525). Conclusion Although carotid bruits are not accurate to confirm or to exclude significant carotid stenoses, these signs are appropriate for directed screening for further investigation with carotid US if the patient

  10. Accumulation of advanced glycation end-products in human dentine.

    PubMed

    Miura, Jiro; Nishikawa, Kantaro; Kubo, Mizuho; Fukushima, Shuichiro; Hashimoto, Mamoru; Takeshige, Fumio; Araki, Tsutomu

    2014-02-01

    Cross-linking of collagen by Advanced Glycation End-products (AGEs) occurs by non-enzymatic glycation (Maillard reaction). The purpose of this study was to examine whether AGEs are formed in human dentinal collagen, and to consider any possible influence of AGEs on dentinal physiology. Mechanical characteristics, fluorescence spectra and immunohistochemical analyses of demineralized dentine sections from young subjects were compared with those of aged ones. The same investigations were performed with young dentine artificially glycated by incubation in 0.1M ribose solution. Indentation measurement indicated that the sections from aged dentine were mechanically harder than those from young dentine. The hardness of young dentine increased after incubation in ribose solution. Fluorescence peak wavelength of the young dentine was shorter than that of the aged one, but shifted towards the peak wavelength of the aged one after incubation in ribose solution. These changes were considered to be due to accumulation of AGEs. Existence of AGEs in dentinal collagen was confirmed by immunohistochemical analysis. The obtained results suggest that AGEs accumulation occurs in dentinal collagen and is affected by both human age and physiological conditions such as glucose level in blood because dentinal collagen receives nourishment via dental pulp and tubules. PMID:24370182

  11. Counterpulsation with symphony prevents retrograde carotid, aortic, and coronary flows observed with intra-aortic balloon pump support.

    PubMed

    Giridharan, Guruprasad A; Bartoli, Carlo R; Spence, Paul A; Dowling, Robert D; Koenig, Steven C

    2012-07-01

    A counterpulsation device (Symphony) is being developed to provide long-term circulatory support for advanced heart failure (HF) patients. In acute animal experiments, flow waveform patterns in the aortic, carotid, and coronary arteries were compared during Symphony and intra-aortic balloon pump (IABP) support. Human data were examined for similarities. The 30-mL Symphony was compared to a 40-mL IABP in calves with cardiac dysfunction (80-100 kg, n = 8). Aortic pressures and aortic, carotid, and coronary artery flows were simultaneously recorded at baseline (devices off) and during 1:1 and 1:2 support. Forward, retrograde, and mean flows were calculated and compared for each test condition. Findings were also compared to aortic flow measurements recorded in HF patients (n = 21) supported by 40-mL IABP. IABP caused significant retrograde flows in the aorta, coronary (IABP: -24 ± 8 mL/min, Symphony: -6 ± 2 mL/min, baseline: -2 ± 1 mL/min, P < 0.05), and carotid arteries (IABP: -30 ± 5 mL/min, Symphony: -0 ± 0 mL/min, baseline: -0 ± 0 L/min, P < 0.05) during ventricular systole compared to the Symphony. IABP support produced higher diastolic pressure and flow augmentation compared to Symphony. Due to retrograde flows during IABP support, Symphony provided higher overall coronary, carotid, and aortic flows. Similar reduction in total aortic flows due to retrograde flow was observed in HF patients during IABP support. Counterpulsation with an IABP via aortic volume displacement produces retrograde flows during rapid balloon deflation that reduces total flow. Counterpulsation with Symphony via volume removal eliminates retrograde flow and improves total flow more than that achieved with IABP. The Symphony may provide long-term hemodynamic benefits in HF patients.

  12. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease.

    PubMed

    Noordzij, Marjon J; Lefrandt, Joop D; Loeffen, Erik A H; Saleem, Ben R; Meerwaldt, Robbert; Lutgers, Helen L; Smit, Andries J; Zeebregts, Clark J

    2012-02-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was measured using the AGE Reader™ in 56 patients with carotid artery stenosis and in 56 age- and sex-matched healthy controls without diabetes, renal dysfunction or known atherosclerotic disease. SAF was higher in patients with carotid artery stenosis compared to the control group: mean 2.81 versus 2.46 (P = 0.002), but especially in the younger age group of 50-60 years old: mean 2.82 versus 1.94 (P = 0.000). Patients with carotid artery stenosis and PAOD proved to have an even higher SAF than patients with carotid artery stenosis only: mean 3.28 versus 2.66 (P = 0.003). Backward linear regression analysis showed that age, smoking, diabetes mellitus, renal function and the presence of PAOD were the determinants of SAF, but carotid artery stenosis was not. SAF is increased in patients with carotid artery stenosis and PAOD. The univariate and multivariate associations of SAF with age, smoking, diabetes, renal insufficiency and PAOD suggest that increased SAF can be seen as an indicator of widespread atherosclerosis. PMID:21336554

  13. Skin autofluorescence is increased in patients with carotid artery stenosis and peripheral artery disease.

    PubMed

    Noordzij, Marjon J; Lefrandt, Joop D; Loeffen, Erik A H; Saleem, Ben R; Meerwaldt, Robbert; Lutgers, Helen L; Smit, Andries J; Zeebregts, Clark J

    2012-02-01

    Advanced glycation end products (AGEs) have a pivotal role in atherosclerosis. We evaluated skin autofluorescence (SAF), a non-invasive measurement of tissue AGE accumulation, in patients with carotid artery stenosis with and without coexisting peripheral artery occlusive disease (PAOD). SAF was measured using the AGE Reader™ in 56 patients with carotid artery stenosis and in 56 age- and sex-matched healthy controls without diabetes, renal dysfunction or known atherosclerotic disease. SAF was higher in patients with carotid artery stenosis compared to the control group: mean 2.81 versus 2.46 (P = 0.002), but especially in the younger age group of 50-60 years old: mean 2.82 versus 1.94 (P = 0.000). Patients with carotid artery stenosis and PAOD proved to have an even higher SAF than patients with carotid artery stenosis only: mean 3.28 versus 2.66 (P = 0.003). Backward linear regression analysis showed that age, smoking, diabetes mellitus, renal function and the presence of PAOD were the determinants of SAF, but carotid artery stenosis was not. SAF is increased in patients with carotid artery stenosis and PAOD. The univariate and multivariate associations of SAF with age, smoking, diabetes, renal insufficiency and PAOD suggest that increased SAF can be seen as an indicator of widespread atherosclerosis.

  14. [Radiological study of the internal carotid artery].

    PubMed

    Meder, J F; Brugières, P; Leguen, O

    1993-12-01

    Three radiologic methods are used to investigate the internal carotid artery. The main indication of CT scan is the assessment of brain ischaemic complications of carotid disease. Magnetic resonance imaging allows in addition to detect dissecting hematomas and carotid flow abnormalities. Cerebral angiography, which owes much to the advent of digital techniques, remains the standard examination of internal carotid artery. Complications of angiography although rare and usually benign explain the recent development of less invasive explorations such as dynamic CT scan and magnetic resonance angiography. This latter method is still under evaluation for diagnosis of carotid stenosis and small size aneurysms.

  15. Carotid plaque characterization using CT and MRI scans for synergistic image analysis

    NASA Astrophysics Data System (ADS)

    Getzin, Matthew; Xu, Yiqin; Rao, Arhant; Madi, Saaussan; Bahadur, Ali; Lennartz, Michelle R.; Wang, Ge

    2014-09-01

    Noninvasive determination of plaque vulnerability has been a holy grail of medical imaging. Despite advances in tomographic technologies , there is currently no effective way to identify vulnerable atherosclerotic plaques with high sensitivity and specificity. Computed tomography (CT) and magnetic resonance imaging (MRI) are widely used, but neither provides sufficient information of plaque properties. Thus, we are motivated to combine CT and MRI imaging to determine if the composite information can better reflect the histological determination of plaque vulnerability. Two human endarterectomy specimens (1 symptomatic carotid and 1 stable femoral) were imaged using Scanco Medical Viva CT40 and Bruker Pharmascan 16cm 7T Horizontal MRI / MRS systems. μCT scans were done at 55 kVp and tube current of 70 mA. Samples underwent RARE-VTR and MSME pulse sequences to measure T1, T2 values, and proton density. The specimens were processed for histology and scored for vulnerability using the American Heart Association criteria. Single modality-based analyses were performed through segmentation of key imaging biomarkers (i.e. calcification and lumen), image registration, measurement of fibrous capsule, and multi-component T1 and T2 decay modeling. Feature differences were analyzed between the unstable and stable controls, symptomatic carotid and femoral plaque, respectively. By building on the techniques used in this study, synergistic CT+MRI analysis may provide a promising solution for plaque characterization in vivo.

  16. A Novel Carotid Device for Embolic Diversion: Lessons Learned from a 'First in Man' Trial in Patients with Atrial Fibrillation

    SciTech Connect

    Sievert, Horst Franke, Jennifer; Grad, Ygael; Nishri, Boaz; Assaf, Yaron; Yodfat, Ofer; Roemer, Albrecht; Robertson, Greg C.; Stone, Gregg W.

    2012-04-15

    Purpose: This study was designed to investigate a novel device that was developed to direct emboli away from the internal carotid artery to the external carotid artery to prevent embolic stroke while avoiding the necessity for anticoagulation with warfarin. Methods: A stent-like, self-expandable filter was developed consisting of fine cobalt alloy mesh. After promising preclinical animal testing, the device was implanted into the common carotid artery extending into the external carotid artery in three patients with atrial fibrillation, each of whom were at high-risk for cerebral emboli and were suboptimal candidates for anticoagulation. Follow-up was performed clinically and with carotid duplex ultrasound. Results: The implantation was successful in all three patients. Unrestricted flow through the filter was demonstrated in each patient at 6 months by duplex sonography. However, at 7 months ultrasound demonstrated occlusion of the internal carotid artery filter in one patient, which was subsequently confirmed by angiography. Subtotal filter occlusion occurred in a second patient at 14 months. Neither patient had clinical symptoms. Both internal carotid arteries were successfully recanalized using standard angioplasty techniques without complication. The third patient had completely normal carotid blood flow at 29 months follow-up. Conclusions: Implantation of a novel device intended to divert emboli away from the internal carotid artery was feasible, but resulted in occlusive neointimal proliferation in two of three patients. These results demonstrate a discrepancy from the findings of preclinical animal studies and human investigation.

  17. Cerebral hemodynamic changes and electroencephalography during carotid endarterectomy

    SciTech Connect

    Algotsson, L.; Messeter, K.; Rehncrona, S.; Skeidsvoll, H.; Ryding, E. )

    1990-05-01

    Some patients undergoing endarterectomy for occlusive carotid artery disease run a risk of brain ischemia during cross-clamping of the artery. The present study of 15 patients was undertaken to evaluate changes in cerebral blood flow (CBF), as measured with an intravenous (IV) tracer (133Xenon) technique, and to relate CBF changes to changes in the electroencephalogram (EEG). CBF was measured before and after induction of anesthesia, during cross-clamping of the carotid artery, after release of the clamps, and at 24 hours after the operation. All the patients were anesthetized with methohexitone, fentanyl, and nitrous oxide and oxygen. EEG was continuously recorded during the operation. Carotid artery shunts were not used. In 8 patients, cross-clamping of the carotid artery did not influence the EEG. In this group of patients, induction of anesthesia caused a 38% decrease in CBF, which presumably reflects the normal reaction to the anesthetic agent given. There were no further changes in CBF during cross-clamping. In 7 patients, the EEG showed signs of deterioration during the intraoperative vascular occlusion. In these patients, anesthesia did not cause any CBF change, whereas cross-clamping the artery induced a 33% decrease in CBF. In individual patients, the severity of EEG changes correlated with the decrease in CBF. The absence of a change in CBF by anesthesia and a decrease due to cross-clamping of the carotid artery may be explained by the presence of a more advanced cerebrovascular disease and an insufficiency to maintain CBF during cross-clamping.

  18. The CD4/CD8 Ratio is Inversely Associated with Carotid Intima-Media Thickness Progression in Human Immunodeficiency Virus-Infected Patients on Antiretroviral Treatment.

    PubMed

    Bernal Morell, Enrique; Serrano Cabeza, José; Muñoz, Ángeles; Marín, Irene; Masiá, Mar; Gutiérrez, Félix; Cano, Alfredo

    2016-07-01

    Inversion of the CD4/CD8 ratio (<1) has been identified as a surrogate marker of immunosenescence and an independent predictor of AIDS events in HIV-infected patients and mortality in the general population. We aimed to assess the association between the CD4/CD8 ratio and carotid intima-media thickness (cIMT) progression in treated HIV-infected patients as a marker of coronary heart disease. A longitudinal study was conducted during 3 years in 96 virally suppressed HIV-infected patients receiving antiretroviral treatment (ART). We analyzed the associations between the CD4/CD8 ratio, cardiovascular risk factors, and antiretroviral treatment (ART) and progression of subclinical atherosclerosis assessed using cIMT at baseline and after 3 years. Finally, 96 patients completed the study. Seventy six (79.1%) patients were male, aged 44 ± 10 years; 39 (40.6%) were on treatment with protease inhibitors; 49 (51.04%) with nonnucleoside reverse transcriptase inhibitors, 6 (6.25%) with integrase inhibitors, 3 (3.12%) with maraviroc, and 2 (2.08%) just with nucleoside reverse transcriptase inhibitors. The mean of ART exposition was 6.9 ± 5.9 years. Twenty six (27%) patients had family history of ischemic heart disease, 51 (53.12%) were smokers, 12 (12.5%) were hypertensive, 4 (4.16%) had type 2 diabetes, 23 (23.9%) had dyslipidemia, and 31 (32.3%) were infected with hepatitis C virus. Baseline cIMT was significantly associated with age (rho = 0.497; p < .001), basal glucemia (rho = 0.323; p = .001), triglycerides (rho = 0.232; p = .023), Framingham risk score (rho = 0.324; p = .001), CD4/CD8 ratio (rho = -0.176; p = .05), and dyslipidemia (0.72 ± 0.16 mm vs. 0.63 ± 0.11 mm; p = .029). In multivariable analysis where cardiovascular risk factor and ART were included, cIMT progression was inversely associated with CD4/CD8 ratio [odds ratio (OR) = 0.283; confidence interval (95% CI) 0.099-0.809; p = .019

  19. Technical Advancement and Human Progress and The Problems of Education.

    ERIC Educational Resources Information Center

    Bixby, Louis W.

    1980-01-01

    Projects and discusses possible future developments resulting from electrochemical technological advancements. Educational implications are explored, and examples of integrated learning in diverse interest areas are given. (CS)

  20. Serum Osteoprotegerin Is Associated With Calcified Carotid Plaque

    PubMed Central

    Kwon, Ami; Choi, Yun-Seok; Choi, Yong-Won; Chung, Woo-Baek; Park, Chul-Soo; Chung, Wook-Sung; Lee, Man-Young; Youn, Ho-Joong

    2016-01-01

    Abstract Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ± 9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis. PMID:27082605

  1. Factor analytic reduction of the carotid-cardiac baroreflex parameters

    NASA Technical Reports Server (NTRS)

    Ludwig, David A.

    1989-01-01

    An accepted method for measuring the responsiveness of the carotid-cardiac baroreflex to arterial pressure changes is to artificially stimulate the baroreceptors in the neck. This is accomplished by using a pressurized neck cuff which constricts and distends the carotid artery and subsequently stimulates the baroreceptors. Nine physiological responses to this type of stimulation are quantified and used as indicators of the baroreflex. Thirty male humans between the ages 27 and 46 underwent the carotid-cardiac baroreflex test. The data for the nine response parameters were analyzed by principle component factor analysis. The results of this analysis indicated that 93 percent of the total variance across all nine parameters could be explained in four dimensions. Examination of the factor loadings following an orthogonal rotation of the principle components indicated four well defined dimensions. The first two dimensions reflected location points for R-R interval and carotid distending pressure respectively. The third dimension was composed of measures reflecting the gain of the reflex. The fourth dimension was the ratio of the resting R-R interval to R-R interval during simulated hypertension. The data suggests that the analysis of all nine baroreflex parameters is redundant.

  2. Dengue human infection models to advance dengue vaccine development.

    PubMed

    Larsen, Christian P; Whitehead, Stephen S; Durbin, Anna P

    2015-12-10

    Dengue viruses (DENV) currently infect approximately 400 million people each year causing millions to seek care and overwhelming the health care infrastructure in endemic areas. Vaccines to prevent dengue and therapeutics to treat dengue are not currently available. The efficacy of the most advanced candidate vaccine against symptomatic dengue in general and DENV-2 in particular was much lower than expected, despite the ability of the vaccine to induce neutralizing antibody against all four DENV serotypes. Because seroconversion to the DENV serotypes following vaccination was thought to be indicative of induced protection, these results have made it more difficult to assess which candidate vaccines should or should not be evaluated in large studies in endemic areas. A dengue human infection model (DHIM) could be extremely valuable to down-select candidate vaccines or therapeutics prior to engaging in efficacy trials in endemic areas. Two DHIM have been developed to assess the efficacy of live attenuated tetravalent (LATV) dengue vaccines. The first model, developed by the Laboratory of Infectious Diseases at the U. S. National Institutes of Health, utilizes a modified DENV-2 strain DEN2Δ30. This virus was derived from the DENV-2 Tonga/74 that caused only very mild clinical infection during the outbreak from which it was recovered. DEN2Δ30 induced viremia in 100%, rash in 80%, and neutropenia in 27% of the 30 subjects to whom it was given. The Walter Reed Army Institute of Research (WRAIR) is developing a DHIM the goal of which is to identify DENV that cause symptomatic dengue fever. WRAIR has evaluated seven viruses and has identified two that meet dengue fever criteria. Both of these models may be very useful in the evaluation and down-selection of candidate dengue vaccines and therapeutics. PMID:26424605

  3. Dengue human infection models to advance dengue vaccine development.

    PubMed

    Larsen, Christian P; Whitehead, Stephen S; Durbin, Anna P

    2015-12-10

    Dengue viruses (DENV) currently infect approximately 400 million people each year causing millions to seek care and overwhelming the health care infrastructure in endemic areas. Vaccines to prevent dengue and therapeutics to treat dengue are not currently available. The efficacy of the most advanced candidate vaccine against symptomatic dengue in general and DENV-2 in particular was much lower than expected, despite the ability of the vaccine to induce neutralizing antibody against all four DENV serotypes. Because seroconversion to the DENV serotypes following vaccination was thought to be indicative of induced protection, these results have made it more difficult to assess which candidate vaccines should or should not be evaluated in large studies in endemic areas. A dengue human infection model (DHIM) could be extremely valuable to down-select candidate vaccines or therapeutics prior to engaging in efficacy trials in endemic areas. Two DHIM have been developed to assess the efficacy of live attenuated tetravalent (LATV) dengue vaccines. The first model, developed by the Laboratory of Infectious Diseases at the U. S. National Institutes of Health, utilizes a modified DENV-2 strain DEN2Δ30. This virus was derived from the DENV-2 Tonga/74 that caused only very mild clinical infection during the outbreak from which it was recovered. DEN2Δ30 induced viremia in 100%, rash in 80%, and neutropenia in 27% of the 30 subjects to whom it was given. The Walter Reed Army Institute of Research (WRAIR) is developing a DHIM the goal of which is to identify DENV that cause symptomatic dengue fever. WRAIR has evaluated seven viruses and has identified two that meet dengue fever criteria. Both of these models may be very useful in the evaluation and down-selection of candidate dengue vaccines and therapeutics.

  4. Human factors of advanced technology (glass cockpit) transport aircraft

    NASA Technical Reports Server (NTRS)

    Wiener, Earl L.

    1989-01-01

    A three-year study of airline crews at two U.S. airlines who were flying an advanced technology aircraft, the Boeing 757 is discussed. The opinions and experiences of these pilots as they view the advanced, automated features of this aircraft, and contrast them with previous models they have flown are discussed. Training for advanced automation; (2) cockpit errors and error reduction; (3) management of cockpit workload; and (4) general attitudes toward cockpit automation are emphasized. The limitations of the air traffic control (ATC) system on the ability to utilize the advanced features of the new aircraft are discussed. In general the pilots are enthusiastic about flying an advanced technology aircraft, but they express mixed feelings about the impact of automation on workload, crew errors, and ability to manage the flight.

  5. Spontaneous internal carotid artery dissection.

    PubMed

    Khimenko, L P; Esham, H R; Ahmed, W

    2000-10-01

    Once considered uncommon, spontaneous dissection of the carotid artery is an increasingly recognized cause of stroke, headache, cranial nerve palsy, or ophthalmologic events, especially in young adults. Even in the presence of existing signs and symptoms, the diagnosis can be missed by experienced physicians of all specialties. We report a case of spontaneous internal carotid artery dissection in a 38-year-old woman with a cortical stroke and visual disturbances as initial symptoms. The diagnosis was confirmed by magnetic resonance imaging/angiography and by angiography. Prompt anticoagulation was instituted, and the patient had complete resolution of symptoms. Cervicocephalic arterial dissection should be included in the differential diagnosis of the causes of cerebrovascular events.

  6. Carotid endarterectomy: current consensus and controversies.

    PubMed

    Meerwaldt, Robbert; Hermus, Linda; Reijnen, Michel M P J; Zeebregts, Clark J

    2010-10-01

    Stroke is the third most common cause of mortality, and carotid artery stenosis causes 8% to 29% of all ischemic strokes. Best medical treatment forms the basis of carotid stenosis treatment, and carotid endarterectomy (CEA) has an additional beneficial effect in high-grade stenosis. Carotid angioplasty and stenting (CAS) has challenged CEA as a primary carotid intervention. At present, CEA remains the gold standard, but in the future, CAS techniques will evolve and might become beneficial for subgroups of patients with carotid stenosis. This chapter briefly describes the history of carotid interventions and current consensus and controversies in CEA. In the last two years, several meta-analyses were published on a variety of aspects of best medical treatment, CEA, and CAS. It is still a matter of debate as to whether asymptomatic patients with carotid stenosis should undergo a carotid intervention. Especially because medical treatment has dramatically evolved since the early carotid trials. On the other hand, it is clear that carotid interventions in symptomatic patients with a high-grade stenosis should be performed as early as possible after the initial neurological event in order to achieve optimal stroke risk reduction. In CEA, the use of patching is advocated above primary closure, while the role of selective patching is still unclear. No differences in stroke and mortality rates are observed for routine versus selective shunting, for conventional versus eversion CEA, or for local versus general anesthesia. It is anticipated that in the future, there will be several interesting developments in carotid interventions such as plaque morphology analysis, acute interventions during stroke in progress, and further evolvement of CAS techniques. PMID:21082576

  7. Carotid endarterectomy: current consensus and controversies.

    PubMed

    Meerwaldt, Robbert; Hermus, Linda; Reijnen, Michel M P J; Zeebregts, Clark J

    2010-10-01

    Stroke is the third most common cause of mortality, and carotid artery stenosis causes 8% to 29% of all ischemic strokes. Best medical treatment forms the basis of carotid stenosis treatment, and carotid endarterectomy (CEA) has an additional beneficial effect in high-grade stenosis. Carotid angioplasty and stenting (CAS) has challenged CEA as a primary carotid intervention. At present, CEA remains the gold standard, but in the future, CAS techniques will evolve and might become beneficial for subgroups of patients with carotid stenosis. This chapter briefly describes the history of carotid interventions and current consensus and controversies in CEA. In the last two years, several meta-analyses were published on a variety of aspects of best medical treatment, CEA, and CAS. It is still a matter of debate as to whether asymptomatic patients with carotid stenosis should undergo a carotid intervention. Especially because medical treatment has dramatically evolved since the early carotid trials. On the other hand, it is clear that carotid interventions in symptomatic patients with a high-grade stenosis should be performed as early as possible after the initial neurological event in order to achieve optimal stroke risk reduction. In CEA, the use of patching is advocated above primary closure, while the role of selective patching is still unclear. No differences in stroke and mortality rates are observed for routine versus selective shunting, for conventional versus eversion CEA, or for local versus general anesthesia. It is anticipated that in the future, there will be several interesting developments in carotid interventions such as plaque morphology analysis, acute interventions during stroke in progress, and further evolvement of CAS techniques.

  8. Carotid Stump Syndrome: Pathophysiology and Endovascular Treatment Options

    SciTech Connect

    Lakshminarayan, Raghuram; Scott, Paul M.; Robinson, Graham J.; Ettles, Duncan F.

    2011-02-15

    Carotid stump syndrome is one of the recognised causes of recurrent ipsilateral cerebrovascular events after occlusion of the internal carotid artery. It is believed that microemboli arising from the stump of the occluded internal carotid artery or the ipsilateral external carotid artery can pass into the middle cerebral artery circulation as a result of patent external carotid-internal carotid anastomotic channels. Different pathophysiologic causes of this syndrome and endovascular options for treatment are discussed.

  9. Quantification of carotid vessel atherosclerosis

    NASA Astrophysics Data System (ADS)

    Chiu, Bernard; Egger, Micaela; Spence, J. D.; Parraga, Grace; Fenster, Aaron

    2006-03-01

    Atherosclerosis is characterized by the development of plaques in the arterial wall, which ultimately leads to heart attacks and stroke. 3D ultrasound (US) has been used to screen patients' carotid arteries. Plaque measurements obtained from these images may aid in the management and monitoring of patients, and in evaluating the effect of new treatment options. Different types of measures for ultrasound phenotypes of atherosclerosis have been proposed. Here, we report on the development and application of a method used to analyze changes in carotid plaque morphology from 3D US images obtained at two different time points. We evaluated our technique using manual segmentations of the wall and lumen of the carotid artery from images acquired in two US scanning sessions. To incorporate the effect of intraobserver variability in our evaluation, manual segmentation was performed five times each for the arterial wall and lumen. From this set of five segmentations, the mean wall and lumen surfaces were reconstructed, with the standard deviation at each point mapped onto the surfaces. A correspondence map between the mean wall and lumen surfaces was then established, and the thickness of the atherosclerotic plaque at each point in the vessel was estimated to be the distance between each correspondence pairs. The two-sample Student's t-test was used to judge whether the difference between the thickness values at each pair corresponding points of the arteries in the two 3D US images was statistically significant.

  10. Rat Carotid Artery Balloon Injury Model

    PubMed Central

    Tulis, David Anthony

    2010-01-01

    i. Summary Numerous and diverse experimental animal models have been used over the years to examine reactions to various forms of blood vessel disease and/or injury across species and in multiple vascular beds in a cumulative effort to relate these findings to the human condition. In this context, the rat carotid artery balloon injury model is highly characterized and commonly used for investigating gross morphological, cellular, biochemical, and molecular components of the response to experimentally-induced arterial injury. The mechanical damage caused by the balloon catheter completely removes the intimal endothelial lining and creates a distending mural injury in the operated vessel. This elicits a reproducible remodeling response characterized by vascular smooth muscle cell (SMC) mitogenesis and migration (via phenotypic switching), SMC apoptosis, partial vascular endothelial cell regeneration, enhanced matrix synthesis, and establishment of an invasive neointima in time-dependent fashion. This multi-factorial process allows for investigation of these many important pathophysiological processes and can serve as a valuable “proof-of-concept” tool to verify and substantiate in vitro results; however, inherent anatomical and adaptive constraints of this in vivo model ration comparison to the diseased human system (see Note 1). In this chapter, brief overview of the materials needed and the methodologies commonly employed for successful routine performance of this important experimental animal model will be provided. Individual sub-sections will cover animal care and handling, pre- and post-operative procedures, and the surgery proper. Protocols for histopathology and morphometry and procedures for data management and interpretation pertinent to the rat carotid artery balloon injury model will be discussed in Chapter __ of this series. Notes will conclude with important caveats, limitations, and considerations for practical use of this technique. PMID:18287662

  11. Markers of inflammation associated with plaque progression and instability in patients with carotid atherosclerosis.

    PubMed

    Ammirati, Enrico; Moroni, Francesco; Norata, Giuseppe Danilo; Magnoni, Marco; Camici, Paolo G

    2015-01-01

    Atherosclerosis is the focal expression of a systemic disease affecting medium- and large-sized arteries, in which traditional cardiovascular risk factor and immune factors play a key role. It is well accepted that circulating biomarkers, including C-reactive protein and interleukin-6, reliably predict major cardiovascular events, including myocardial infarction or death. However, the relevance of biomarkers of systemic inflammation to atherosclerosis progression in the carotid artery is less established. The large majority of clinical studies focused on the association between biomarkers and subclinical atherosclerosis, that is, carotid intima-media thickening (cIMT), which represents an earlier stage of the disease. The aim of this work is to review inflammatory biomarkers that were associated with a higher atherosclerotic burden, a faster disease progression, and features of plaque instability, such as inflammation or neovascularization, in patients with carotid atherosclerotic plaque, which represents an advanced stage of disease compared with cIMT. The association of biomarkers with the occurrence of cerebrovascular events, secondary to carotid plaque rupture, will also be presented. Currently, the degree of carotid artery stenosis is used to predict the risk of future cerebrovascular events in patients affected by carotid atherosclerosis. However, this strategy appears suboptimal. The identification of suitable biomarkers could provide a useful adjunctive criterion to ensure better risk stratification and optimize management. PMID:25960621

  12. Increased Vessel Depiction of the Carotid Bifurcation with a Specialized 16-Channel Phased Array Coil at 3T

    PubMed Central

    Tate, Quinn; Kim, Seong-Eun; Treiman, Gerald; Parker, Dennis L.; Hadley, J. Rock

    2012-01-01

    The purpose of this work was to design and construct a multi-channel receive-only RF coil for 3 Tesla magnetic resonance imaging of the human carotid artery and bifurcation with optimized signal to noise ratio in the carotid vessels along the full extent of the neck. A neck phantom designed to match the anatomy of a subject with a neck representing the body habitus often seen in subjects with carotid arterial disease, was constructed. Sixteen circular coil elements were arranged on a semi-rigid fiberglass former that closely fit the shape of the phantom, resulting in a 16-channel bilateral phased array coil. Comparisons were made between this coil and a typical 4-channel carotid coil in a study of 10 carotid vessels in 5 healthy volunteers. The 16-channel carotid coil showed a 73% average improvement in signal to noise ratio (SNR) at the carotid bifurcation. This coil also maintained an SNR greater than the peak SNR of the 4-channel coil over a vessel length of 10 cm. The resulting increase in SNR improved vessel depiction of the carotid arteries over an extended field of view, and demonstrated better image quality for higher parallel imaging reduction factors compared to the 4-channel coil. PMID:22777692

  13. [Advances on research of human exposure to triclosan].

    PubMed

    Jin, Chenye; Chen, Yiming; Zhang, Peiqi; Xiong, Zhezhen; Wang, Caifeng; Tian, Ying

    2016-03-01

    Triclosan, a broad-spectrum antimicrobial agent, was reported to have been widely detected in various human biological samples such as urine, blood and human milk among foreign populations. In China, limited reports have been found on human exposure to triclosan, and the reported urinary triclosan concentrations were significantly lower than that of American populations. Besides, the potential influencing factors still remain unclear regarding human exposure to triclosan, but evidences suggest that those in middle age and with higher household income and higher social class tend to have higher urinary triclosan concentrations. Furthermore, triclosan exposure tend to differ by sex, geography, heredity, metabolism and life style.

  14. Planetary protection issues in advance of human exploration of Mars.

    PubMed

    McKay, C P; Davis, W L

    1989-01-01

    Current planetary quarantine considerations focus on robotic missions and attempt a policy of no biological contamination. The presence of humans on Mars, however, will inevitably result in biological contamination and physical alteration of the local environment. The focus of planetary quarantine must therefore shift toward defining and minimizing the inevitable contamination associated with humans. This will involve first determining those areas that will be affected by the presence of a human base, then verifying that these environments do not harbor indigenous life nor provide sites for Earth bacteria to grow. Precursor missions can provide salient information that can make more efficient the planning and design of human exploration missions. In particular, a robotic sample return mission can help to eliminate the concern about returning samples with humans or the return of humans themselves from a planetary quarantine perspective. Without a robotic return the cost of quarantine that would have to be added to a human mission may well exceed the cost of a robotic return mission. Even if the preponderance of scientific evidence argues against the presence of indigenous life, it must be considered as part of any serious planetary quarantine analysis for missions to Mars. If there is life on Mars, the question of human exploration assumes an ethical dimension. PMID:11537372

  15. Planetary protection issues in advance of human exploration of Mars

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.; Davis, Wanda L.

    1989-01-01

    The major planetary quarantine issues associated with human exploration of Mars, which is viewed as being more likely to harbor indigenous life than is the moon, are discussed. Special attention is given to the environmental impact of human missions to Mars due to contamination and mechanical disturbances of the local environment, the contamination issues associated with the return of humans, and the planetary quarantine strategy for a human base. It is emphasized that, in addition to the question of indigenous life, there may be some concern of returning to earth the earth microorganisms that have spent some time in the Martian environment. It is suggested that, due to the fact that a robot system can be subjected to more stringent controls and protective treatments than a mission involving humans, a robotic sample return mission can help to eliminate many planetary-quarantine concerns about returning samples.

  16. Compliant Wall Simulation of a Healthy Carotid Bifurcation

    NASA Astrophysics Data System (ADS)

    Williamson, Shobha; Rayz, Vitaliy; Saloner, David; Berger, Stanley

    2003-11-01

    Cardiovascular disease is a major cause of mortality in the industrialized world. Together with the genetic causes of this disease, fluid-structure interaction (FSI) in the arterial system plays a role in the development of arteriosclerosis. In an effort to further understand this disease, an FSI model of the carotid artery is in progress. To construct this model, we begin with compliant arterial wall deformation considered under transient global blood pressure. Vessel walls are composed of collagen fibers, elastin, smooth muscle, and water. Due to its complexity and variation among humans, it is difficult to create an accurate mechanical description of this material. Hence, we begin by way of isotropic properties with the future intent of anisotropic modeling. Using these parameters, a pulsatile 3D model of wall movement for a healthy carotid artery is presented. Supported under a National Science Foundation Graduate Research Fellowship, NIH Grant HL61823, and PBD, Inc.

  17. An approach towards molecular imaging of activated platelets allows imaging of symptomatic human carotid plaques in a new model of a tissue flow chamber.

    PubMed

    von Elverfeldt, Dominik; Meissner, Mirko; Peter, Karlheinz; Paul, Dominik; Meixner, Fabian; Neudorfer, Irene; Merkle, Annette; Harloff, Andreas; Zirlik, Andreas; Schöllhorn, Joachim; Markl, Michael; Hennig, Jürgen; Bode, Christoph; von zur Muhlen, Constantin

    2012-01-01

    The development of magnetic resonance imaging (MRI) contrast agents targeting epitopes in atherosclerosis is of general interest. In particular, early detection of activated platelets as key players in plaque rupture could provide improved triage of patients. However, so far the efficiency of contrast agents targeting human pathologies can only be examined in animal experiments, which do not necessarily reflect human in vivo conditions. We therefore describe application of a contrast agent targeting activated human platelets in an MRI tissue flow chamber, allowing detection and characterization of contrast agent binding. Microparticles of iron oxide (MPIO) were conjugated to an antibody targeting ligand-induced binding sites (LIBS) on the activated platelet glycoprotein IIb/IIIa-receptor or to control antibody, resulting in LIBS-MPIO or control-MPIO contrast agent. Human endarterectomy specimens from patients with acute stroke or transient ischemic attack were imaged ex vivo before and after contrast agent perfusion using a 9.4 T MRI system. Specimens were measured under static (n = 18) or flow conditions (n = 18) in a specially designed flow chamber setup, simulating physiological conditions in a stenosed vessel. A significant MPIO-induced negative contrast was achieved in MRI by LIBS-MPIO in specimens under static and flow conditions (LIBS-MPIO vs control-MPIO: p < 0.01), and the location of LIBS-MPIO binding corresponded well between histology and MRI (p < 0.05). The number of MPIOs per platelet area on endarterectomy specimens in histology was significantly higher with LIBS-MPIO (p < 0.001). Furthermore, the intensity of contrast agent binding and signal change showed the potential to reflect the severity of clinical symptoms. LIBS-MPIO allows the detection of activated platelets on the surface of symptomatic atherosclerotic human plaques using molecular MRI. Furthermore, the MRI tissue flow chamber setup described could help to evaluate

  18. Carotid Artery Stenting: Single-Center Experience Over 11 Years

    SciTech Connect

    Nolz, Richard Schernthaner, Ruediger Egbert; Cejna, Manfred; Schernthaner, Melanie Lammer, Johannes Schoder, Maria

    2010-04-15

    This article reports the results of carotid artery stenting during an 11-year period. Data from 168 carotid artery stenting procedures (symptomatic, n = 55; asymptomatic, n = 101; symptoms not accessible, n = 12) were retrospectively collected. Primary technical success rate, neurological events in-hospital, access-site complications, and contrast-induced nephropathy (n = 118) were evaluated. To evaluate the influence of experience in carotid artery stenting on intraprocedural neurologic complications, patients were divided into two groups. Group 1 included the first 80 treated patients, and group 2 the remainder of the patients (n = 88). In-stent restenoses at last-follow-up examinations (n = 89) were assessed. The overall primary technical success rate was 95.8%. The in-hospital stroke-death rate was 3.0% (n = 5; symptomatic, 5.4%; asymptomatic, 2.0%; p = 0.346). Neurologic complications were markedly higher in group 1 (4.2%; three major strokes; symptomatic, 2.8%, asymptomatic, 1.4%) compared to group 2 (2.4%; one major and one minor stroke-symptomatic, 1.2%, asymptomatic 1.2%), but this was not statistically significant. Further complications were access-site complications in 12 (7.1%), with surgical revision required in 1 (0.6%) and mild contrast-induced nephropathy in 1 (0.85%). Twenty-one (23.6%) patients had >50% in-stent restenosis during a mean follow-up of 28.2 months. In conclusion, advanced experience in carotid artery stenting leads to an acceptable periprocedural stroke-death rate. In-stent restenosis could be a critical factor during the follow-up course.

  19. Selective aggregation of PAMAM dendrimer nanocarriers and PAMAM/ZnPc nanodrugs on human atheromatous carotid tissues: a photodynamic therapy for atherosclerosis

    NASA Astrophysics Data System (ADS)

    Spyropoulos-Antonakakis, Nikolaos; Sarantopoulou, Evangelia; Trohopoulos, Panagiotis N.; Stefi, Aikaterina L.; Kollia, Zoe; Gavriil, Vassilios E.; Bourkoula, Athanasia; Petrou, Panagiota S.; Kakabakos, Sotirios; Semashko, Vadim V.; Nizamutdinov, Alexey S.; Cefalas, Alkiviadis-Constantinos

    2015-05-01

    Photodynamic therapy (PDT) involves the action of photons on photosensitive molecules, where atomic oxygen or OH- molecular species are locally released on pathogenic human cells, which are mainly carcinogenic, thus causing cell necrosis. The efficacy of PDT depends on the local nanothermodynamic conditions near the cell/nanodrug system that control both the level of intracellular translocation of nanoparticles in the pathogenic cell and their agglomeration on the cell membrane. Dendrimers are considered one of the most effective and promising drug carriers because of their relatively low toxicity and negligible activation of complementary reactions. Polyamidoamine (PAMAM) dendrite delivery of PDT agents has been investigated in the last few years for tumour selectivity, retention, pharmacokinetics and water solubility. Nevertheless, their use as drug carriers of photosensitizing molecules in PDT for cardiovascular disease, targeting the selective necrosis of macrophage cells responsible for atheromatous plaque growth, has never been investigated. Furthermore, the level of aggregation, translocation and nanodrug delivery efficacy of PAMAM dendrimers or PAMAM/zinc phthalocyanine (ZnPc) conjugates on human atheromatous tissue and endothelial cells is still unknown.

  20. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid...

  1. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid...

  2. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid...

  3. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid...

  4. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid...

  5. Distal protection for treatment of complete cervical internal carotid occlusion.

    PubMed

    Hungerford, John P; Chaudry, Imran; Turner, Raymond; Turk, Aquilla S

    2012-01-01

    Distal protection devices (DPD) have been advocated for carotid artery stenting to reduce the risk of distal embolization. These devices were designed for deployment in the straight cervical segment of the internal carotid artery. We present a case of total cervical carotid occlusion recanalized with the aid of a distal protection device deployed 'distally' in the intracranial internal carotid artery.

  6. Advanced human-system interface design review guideline. Evaluation procedures and guidelines for human factors engineering reviews

    SciTech Connect

    O`Hara, J.M.; Brown, W.S.; Baker, C.C.; Welch, D.L.; Granda, T.M.; Vingelis, P.J.

    1994-07-01

    Advanced control rooms will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator`s overall role in the system, the method of information presentation, and the ways in which operators interact with the system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The principal guidance available to the NRC, however, was developed more than ten years ago, well before these technological changes. Accordingly, the human factors guidance needs to be updated to serve as the basis for NRC review of these advanced designs. The purpose of this project was to develop a general approach to advanced HSI review and the human factors guidelines to support. NRC safety reviews of advanced systems. This two-volume report provides the results of the project. Volume I describes the development of the Advanced HSI Design Review Guideline (DRG) including (1) its theoretical and technical foundation, (2) a general model for the review of advanced HSIs, (3) guideline development in both hard-copy and computer-based versions, and (4) the tests and evaluations performed to develop and validate the DRG. Volume I also includes a discussion of the gaps in available guidance and a methodology for addressing them. Volume 2 provides the guidelines to be used for advanced HSI review and the procedures for their use.

  7. Advanced control rooms and crew performance issues: Implications for human reliability

    SciTech Connect

    O`Hara, J.M.; Hall, R.E.

    1991-12-31

    Recent trends in advanced control room (ACR) design are considered with respect to their impact on human performance. It is concluded that potentially negative influences exist, however, a variety of factors make it difficult to model, analyze, and quantify these effects for human reliability analyses (HRAs).

  8. Human rights advances in women's reproductive health in Africa.

    PubMed

    Ngwena, Charles G; Brookman-Amissah, Eunice; Skuster, Patty

    2015-05-01

    The African Commission on Human and Peoples' Rights recently adopted General Comment No 2 to interpret provisions of Article 14 of the Protocol to the African Charter on the Rights Women. The provisions relate to women's rights to fertility control, contraception, family planning, information and education, and abortion. The present article highlights the General Comment's potential to promote women's sexual and reproductive rights in multiple ways. The General Comment's human rights value goes beyond providing states with guidance for framing their domestic laws, practices, and policies to comply with treaty obligations. General Comment No 2 is invaluable in educating all stakeholders-including healthcare providers, lawyers, policymakers, and judicial officers at the domestic level-about pertinent jurisprudence. Civil society and human rights advocates can use the General Comment to render the state accountable for failure to implement its treaty obligations.

  9. Advanced Research Training in Human Geography: The Scottish Experience

    ERIC Educational Resources Information Center

    Gwanzura-Ottemoeller, Fungisai; Hopkins, Peter; Lorimer, Hayden; Philip, Lorna J.

    2005-01-01

    Formal research training is integral to research degrees in human geography completed in UK higher education institutions today. The Economic and Social Research Council (ESRC) has been the driving force behind the formalization of research training. Arguably less well known among the ESRC research training recommendations is the stipulation that…

  10. Human Relationships That Nurture and Advance the Construction of Knowledge.

    ERIC Educational Resources Information Center

    Herman, William E.; Gwaltney, Thomas M.

    This paper reviews the historical antecedents and theoretical foundation for a constructivist approach to teaching and learning. One neglected characteristic of constructivism apparent in the professional literature is the need to better understand that human relationships in the classroom are often pivotal in helping students construct knowledge.…

  11. Human Factors Evaluation of Advanced Electric Power Grid Visualization Tools

    SciTech Connect

    Greitzer, Frank L.; Dauenhauer, Peter M.; Wierks, Tamara G.; Podmore, Robin

    2009-04-01

    This report describes initial human factors evaluation of four visualization tools (Graphical Contingency Analysis, Force Directed Graphs, Phasor State Estimator and Mode Meter/ Mode Shapes) developed by PNNL, and proposed test plans that may be implemented to evaluate their utility in scenario-based experiments.

  12. Management of Bilateral Carotid Occlusive Disease

    PubMed Central

    Jadhav, Ashutosh P.; Ducruet, Andrew F.; Jankowitz, Brian T.; Jovin, Tudor G.

    2016-01-01

    Background Symptomatic bilateral internal carotid occlusive disease is a rare but potentially devastating entity. Medical therapy alone is associated with high rates of mortality and recurrent stroke. The optimal management of this disease remains poorly understood. Methods A retrospective review of a prospectively maintained database was conducted for patients who presented with an acute stroke in the setting of bilateral carotid occlusive disease between May and October 2013. Results We identified 3 patients. The admission National Institutes of Health Stroke Scale score ranged from 4 to 7. All patients had small- to moderate-sized infarcts in the anterior circulation on presentation. Angiography confirmed bilateral internal carotid occlusions with collateral filling via the posterior communicating artery and retrograde filling via external carotid artery supply to the ophthalmic artery. All patients were initially managed with permissive hypertension and anticoagulation followed by carotid angioplasty and stenting. At 1-year follow-up, all patients demonstrated a modified Rankin scale score of 0-1. Conclusions Carotid stenting may be a safe and effective therapy for patients presenting with symptomatic bilateral carotid occlusions. PMID:27051405

  13. Signal processing at mammalian carotid body chemoreceptors.

    PubMed

    Nurse, Colin A; Piskuric, Nikol A

    2013-01-01

    Mammalian carotid bodies are richly vascularized chemosensory organs that sense blood levels of O(2), CO(2)/H(+), and glucose and maintain homeostatic regulation of these levels via the reflex control of ventilation. Carotid bodies consist of innervated clusters of type I (or glomus) cells in intimate association with glial-like type II cells. Carotid bodies make afferent connections with fibers from sensory neurons in the petrosal ganglia and receive efferent inhibitory innervation from parasympathetic neurons located in the carotid sinus and glossopharyngeal nerves. There are synapses between type I (chemosensory) cells and petrosal afferent terminals, as well as between neighboring type I cells. There is a broad array of neurotransmitters and neuromodulators and their ionotropic and metabotropic receptors in the carotid body. This allows for complex processing of sensory stimuli (e.g., hypoxia and acid hypercapnia) involving both autocrine and paracrine signaling pathways. This review summarizes and evaluates current knowledge of these pathways and presents an integrated working model on information processing in carotid bodies. Included in this model is a novel hypothesis for a potential role of type II cells as an amplifier for the release of a key excitatory carotid body neurotransmitter, ATP, via P2Y purinoceptors and pannexin-1 channels.

  14. [A Case of Carotid Free-Floating Thrombus Treated by Carotid Ultrasonography-Guided Endovascular Approach].

    PubMed

    Otawa, Masato; Kinkori, Takeshi; Watanabe, Kenichi; Ando, Ryo; Tambara, Masao; Arima, Toru

    2016-06-01

    We experienced a case of carotid free-floating thrombus treated by carotid ultrasonography-guided endovascular approach. A 63-year-old man was brought to our hospital with the chief complaint of sudden onset left hemiplegia. MRI revealed acute infarction of the right MCA territory due to the right M1 occlusion. Carotid ultrasonography showed a pedunculated, polypoid mobile plaque floating with the cardiac beat. We attempted ultrasonography-guided endovascular treatment. Under proximal balloon protection, the floating plaque was successfully aspirated into the Penumbra aspiration catheter. Carotid stent was also placed to stabilize the residual pedicle of the plaque. Aspirated plaque was identified as fresh thrombus by pathological examination. Carotid ultrasonography-guided endovascular approach was effective for getting the picture of real-time dynamics of the carotid FFT. PMID:27270147

  15. Hemodynamic changes and baroreflex sensitivity associated with carotid endarterectomy and carotid artery stenting.

    PubMed

    Cao, Qinqin; Zhang, Jun; Xu, Gelin

    2015-01-01

    Atherosclerotic carotid lesion is a major cause of stroke which accounts for up to 20% of ischemic stroke. Aggressive treatment of carotid stenosis may prevent stroke. Currently, carotid endarterectomy (CEA) and carotid artery stenting (CAS) are the first-line treatments for severe carotid stenosis. CEA is superior to medical therapy in preventing stroke and cardiovascular death. CAS has emerged as an alternative to CEA in recent years due to its less invasive nature. However, both CEA and CAS may be associated with adverse hemodynamic changes as well as a variation of carotid baroreflex sensitivity. There is no consensus on which of these two methods is more advantageous concerning the procedure-related hemodynamic changes. This article reviews the hemodynamic changes and baroreflex sensitivity after CEA and CAS. PMID:25999987

  16. Assessing carotid atherosclerosis by fiber-optic multispectral photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Hui, Jie; Li, Rui; Wang, Pu; Phillips, Evan; Bruning, Rebecca; Liao, Chien-Sheng; Sturek, Michael; Goergen, Craig J.; Cheng, Ji-Xin

    2015-03-01

    Atherosclerotic plaque at the carotid bifurcation is the underlying cause of the majority of ischemic strokes. Noninvasive imaging and quantification of the compositional changes preceding gross anatomic changes within the arterial wall is essential for diagnosis of disease. Current imaging modalities such as duplex ultrasound, computed tomography, positron emission tomography are limited by the lack of compositional contrast and the detection of flow-limiting lesions. Although high-resolution magnetic resonance imaging has been developed to characterize atherosclerotic plaque composition, its accessibility for wide clinical use is limited. Here, we demonstrate a fiber-based multispectral photoacoustic tomography system for excitation of lipids and external acoustic detection of the generated ultrasound. Using sequential ultrasound imaging of ex vivo preparations we achieved ~2 cm imaging depth and chemical selectivity for assessment of human arterial plaques. A multivariate curve resolution alternating least squares analysis method was applied to resolve the major chemical components, including intravascular lipid, intramuscular fat, and blood. These results show the promise of detecting carotid plaque in vivo through esophageal fiber-optic excitation of lipids and external acoustic detection of the generated ultrasound. This imaging system has great potential for serving as a point-ofcare device for early diagnosis of carotid artery disease in the clinic.

  17. Oncolytic virotherapy for human malignant mesothelioma: recent advances

    PubMed Central

    Boisgerault, Nicolas; Achard, Carole; Delaunay, Tiphaine; Cellerin, Laurent; Tangy, Frédéric; Grégoire, Marc; Fonteneau, Jean-François

    2015-01-01

    Cancer virotherapy is an attractive alternative to conventional treatments because it offers a wide range of antitumor effects due to 1) the diversity of the oncolytic viruses that are now available and 2) their multifaceted activities against both tumor cells and tumor vessels, in addition to their ability to induce antitumor immune responses. In this review, we summarize preclinical and clinical data regarding the targeting of malignant mesothelioma (MM) by oncolytic viruses. We also discuss the potential of other oncolytic viruses that have already shown antitumor effects against several malignancies in advanced clinical trials but are yet to be tested against MM cells. Finally, we review how the activation of the immune system and combinations with other types of anticancer treatments could support the development of oncolytic virotherapy for the treatment of MM. PMID:27512676

  18. Recent Advances in Computational Mechanics of the Human Knee Joint

    PubMed Central

    Kazemi, M.; Dabiri, Y.; Li, L. P.

    2013-01-01

    Computational mechanics has been advanced in every area of orthopedic biomechanics. The objective of this paper is to provide a general review of the computational models used in the analysis of the mechanical function of the knee joint in different loading and pathological conditions. Major review articles published in related areas are summarized first. The constitutive models for soft tissues of the knee are briefly discussed to facilitate understanding the joint modeling. A detailed review of the tibiofemoral joint models is presented thereafter. The geometry reconstruction procedures as well as some critical issues in finite element modeling are also discussed. Computational modeling can be a reliable and effective method for the study of mechanical behavior of the knee joint, if the model is constructed correctly. Single-phase material models have been used to predict the instantaneous load response for the healthy knees and repaired joints, such as total and partial meniscectomies, ACL and PCL reconstructions, and joint replacements. Recently, poromechanical models accounting for fluid pressurization in soft tissues have been proposed to study the viscoelastic response of the healthy and impaired knee joints. While the constitutive modeling has been considerably advanced at the tissue level, many challenges still exist in applying a good material model to three-dimensional joint simulations. A complete model validation at the joint level seems impossible presently, because only simple data can be obtained experimentally. Therefore, model validation may be concentrated on the constitutive laws using multiple mechanical tests of the tissues. Extensive model verifications at the joint level are still crucial for the accuracy of the modeling. PMID:23509602

  19. Can a closed carotid artery be reopened?

    PubMed

    Issawi, Ahmad; Klopfenstein, Jeffrey

    2015-10-01

    Carotid occlusion is a disease that presents a difficult decision for the treating provider. Traditionally, many providers would opt for expectant management with risk factor reduction and supportive therapy. There is a growing body of literature however pointing to possible improved outcomes of more aggressive treatments, including reopening of the occluded carotid. In this review, we discuss the difficulties involved in diagnosing a patient presenting with symptomatic carotid occlusion, the natural history of the disease, and the emerging treatment options and paradigms of different institutions based on recent literature. PMID:26277365

  20. Setaria digitata in advancing our knowledge of human lymphatic filariasis.

    PubMed

    Perumal, A N I; Gunawardene, Y I N S; Dassanayake, R S

    2016-03-01

    Setaria digitata is a filarial parasite that causes fatal cerebrospinal nematodiasis in goats, sheep and horses, resulting in substantial economic losses in animal husbandry in the tropics. Due to its close resemblance to Wuchereria bancrofti, this nematode is also frequently used as a model organism to study human lymphatic filariasis. This review highlights numerous insights into the morphological, histological, biochemical, immunological and genetic aspects of S. digitata that have broadened our understanding towards the control and eradication of filarial diseases. PMID:25924635

  1. [Clinical significance and functional outcomes of ligation of exterior carotid artery in surgical treatment of oropharyngeal cancer].

    PubMed

    Klochikhin, A L; Trofimov, E I; Gamilovskaia, Iu V; Chistiakov, A L

    2010-01-01

    This work was designed to analyse outcomes of the treatment of 65 patients with advanced oropharyngeal cancer who had received combined treatment including radical resection of the tumour. Thirty three patients underwent surgery without ligation of exterior carotid artery while the remaining 32 (control group) were operated after preceding ligation of this vessel. The influence of ligation of exterior carotid artery on cerebral circulation was evaluated by the following methods: estimation of the intraoperative blood loss from A.T. Staroverov's formula, ultrasound dopplerography of extracranial carotid segments, electroencephalography, measurement of the fields of vision using statistical quantitative perimetry, evaluation of the patients' neurologic status. It was shown that ligation of exterior carotid artery has no apparent effect on the intraoperative blood loss during radical surgery for the management of oropharyngeal cancer nor does it influence healing of the postoperative wound and oncological outcome of this treatment. PMID:20436415

  2. Advanced human-system interface design review guideline. General evaluation model, technical development, and guideline description

    SciTech Connect

    O`Hara, J.M.

    1994-07-01

    Advanced control rooms will use advanced human-system interface (HSI) technologies that may have significant implications for plant safety in that they will affect the operator`s overall role in the system, the method of information presentation, and the ways in which operators interact with the system. The U.S. Nuclear Regulatory Commission (NRC) reviews the HSI aspects of control rooms to ensure that they are designed to good human factors engineering principles and that operator performance and reliability are appropriately supported to protect public health and safety. The principal guidance available to the NRC, however, was developed more than ten years ago, well before these technological changes. Accordingly, the human factors guidance needs to be updated to serve as the basis for NRC review of these advanced designs. The purpose of this project was to develop a general approach to advanced HSI review and the human factors guidelines to support NRC safety reviews of advanced systems. This two-volume report provides the results of the project. Volume I describes the development of the Advanced HSI Design Review Guideline (DRG) including (1) its theoretical and technical foundation, (2) a general model for the review of advanced HSIs, (3) guideline development in both hard-copy and computer-based versions, and (4) the tests and evaluations performed to develop and validate the DRG. Volume I also includes a discussion of the gaps in available guidance and a methodology for addressing them. Volume 2 provides the guidelines to be used for advanced HSI review and the procedures for their use.

  3. Assessing human exposure to airborne pollutants: Advances and opportunities

    SciTech Connect

    Lioy, P.J. )

    1991-08-01

    A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It is also the costliest and most time consuming. The second method is more indirect and involves techniques such as measuring the amount of a contaminant with a stationary monitor and extrapolating exposure by means of personal activity records or mathematical models. Exposure to carbon monoxide inside a car, for example, might be roughly calculated from the amount of time spent in the car and the quantity of carbon monoxide in the car under typical operating conditions. The third method involves biological markers as a measure of the integrated dose within the body and of past contact with pollutants. For example, a marker for airborne lead exposure can be elevated lead levels in the blood. However, this must be weighed against contributions from other media. A final and major point made in the report is the need to have accurate and realistic assessments to ensure optimal reduction of human exposure. To accomplish this, exposure assessment research should be supported by government programs. Although not stated, such research should also be supported by other sectors, including the regulated community.

  4. Evaluation of Carotid Plaque Using Ultrasound Imaging

    PubMed Central

    2016-01-01

    Traditional risk factors for predicting of cardiovascular disease are not always effective predictors for development of cardiovascular events. This review summarizes several newly developed noninvasive imaging techniques for evaluating carotid plaques and their role in cardiovascular disease risk. PMID:27358696

  5. Human mortality at very advanced age might be constant.

    PubMed

    Klemera, P; Doubal, S

    1997-11-01

    An attempt was made to identify the course of the mortality rate at the upper tail of human age. The only known data suitable for this purpose were published by Riggs and Millecchia (J.E. Riggs, R.J. Millecchia, Mech. Ageing Dev. 62 (1992) 191-199) and our analysis follows up their results. By means of mathematical elaboration it was proved that these data imply a constant mortality rate (approx. 25% per year) at ages above 113 years for men and above 116 years for women. Indirect arguments supporting the validity of the source data are discussed. Nevertheless, even if the source data are mistaken, we proved they cannot be the product of purely random errors and our results may contribute to the elucidation of the origin of those systematic errors. PMID:9379712

  6. Complications of cerebral angiography for patients with mild carotid territory ischaemia being considered for carotid endarterectomy.

    PubMed Central

    Hankey, G J; Warlow, C P; Molyneux, A J

    1990-01-01

    It is essential to image the carotid bifurcation adequately in patients with symptomatic carotid territory ischaemia if they are being considered for carotid endarterectomy. Optimal resolution is achieved by selective intraarterial contrast angiography which is an invasive procedure carrying some risk. The overall risk-benefit of carotid endarterectomy is currently being investigated in several large randomised trials in Europe and North America. Because cerebral angiography is a prerequisite for carotid endarterectomy, the risks of cerebral angiography will need to be added to those of surgery when considering whether carotid endarterectomy is effective in the management of these patients. This study evaluated prospectively 382 patients with symptomatically mild carotid ischaemia who had cerebral angiography to visualise a potentially resectable lesion at the carotid bifurcation. Complications followed 14 cerebral angiograms in 13 patients (3.4%); two complications were local (0.5%), two systemic (0.5%) and 10 were neurological (2.6%). The neurological complications were transient (TIA 1, generalised seizure 1) in two patients (0.5%), reversible (stroke) in three (0.8%) and permanent (stroke) in five patients (1.3%). There were no deaths. The significant risk factors for post angiographic stroke were (1) stroke before angiography compared with transient ischaemic attacks of the eye or brain and (2) the presence of greater than or equal to 50% diameter stenosis of the symptomatic internal carotid artery; unfortunately it may be the latter patients who are most at risk of stroke as part of the natural history of their disease and therefore most in need of prophylactic carotid endarterectomy (which requires cerebral angiography). The absolute risk of post-angiographic stroke of patients for cerebral angiography using clinical evaluation and Duplex carotid ultrasound screening. PMID:2118171

  7. Advanced Nuclear Power Concepts for Human Exploration Missions

    SciTech Connect

    Robert L. Cataldo; Lee S. Mason

    2000-06-04

    The design reference mission for the National Aeronautics and Space Administration's (NASA's) human mission to Mars supports a philosophy of living off the land in order to reduce crew risk, launch mass, and life-cycle costs associated with logistics resupply to a Mars base. Life-support materials, oxygen, water, and buffer gases, and the crew's ascent-stage propellant would not be brought from Earth but rather manufactured from the Mars atmosphere. The propellants would be made over {approx}2 yr, the time between Mars mission launch window opportunities. The production of propellants is very power intensive and depends on type, amount, and time to produce the propellants. Closed-loop life support and food production are also power intensive. With the base having several habitats, a greenhouse, and propellant production capability, total power levels reach well over 125 kW(electric). The most mass-efficient means of satisfying these requirements is through the use of nuclear power. Studies have been performed to identify a potential system concept, described in this paper, using a mobile cart to transport the power system away from the Mars lander and provide adequate separation between the reactor and crew. The studies included an assessment of reactor and power conversion technology options, selection of system and component redundancy, determination of optimum separation distance, and system performance sensitivity to some key operating parameters.

  8. Advanced UV Absorbers for the Protection of Human Skin.

    PubMed

    Hüglin, Dietmar

    2016-01-01

    The increasing awareness of the damaging effects of UV radiation to human skin triggered the market introduction of new cosmetic UV absorbers. This article summarizes the outcome of a multi-year research program, in which the author contributed to the development of different new UV filters. First of all, the molecular design and the basic properties of bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT) will be presented. This oil-soluble filter, which today is widely used in both beach products and skin care products, exhibits inherent photostability and strong broad-spectrum UV-A+B absorbance. Based on the concept of micronized organic UV absorbers, the UV-B filter tris biphenyl triazine (TBPT) will be introduced. At present TBPT exhibits the highest efficacy of all cosmetic UV absorbers in the market (measured by area under the UV spectrum). Finally, the concept of liposomogenic UV absorbers will be featured. This approach was developed to create water-resistant UV filters, as liposomogenic structures are thought to integrate into the lipids of the horny layer. Due to prohibitively high costs, this technology did not result in a commercial product so far. PMID:27561611

  9. Advanced UV Absorbers for the Protection of Human Skin.

    PubMed

    Hüglin, Dietmar

    2016-01-01

    The increasing awareness of the damaging effects of UV radiation to human skin triggered the market introduction of new cosmetic UV absorbers. This article summarizes the outcome of a multi-year research program, in which the author contributed to the development of different new UV filters. First of all, the molecular design and the basic properties of bis-ethylhexyloxyphenol methoxyphenyl triazine (BEMT) will be presented. This oil-soluble filter, which today is widely used in both beach products and skin care products, exhibits inherent photostability and strong broad-spectrum UV-A+B absorbance. Based on the concept of micronized organic UV absorbers, the UV-B filter tris biphenyl triazine (TBPT) will be introduced. At present TBPT exhibits the highest efficacy of all cosmetic UV absorbers in the market (measured by area under the UV spectrum). Finally, the concept of liposomogenic UV absorbers will be featured. This approach was developed to create water-resistant UV filters, as liposomogenic structures are thought to integrate into the lipids of the horny layer. Due to prohibitively high costs, this technology did not result in a commercial product so far.

  10. Advanced Analysis of Pharmaco-Sleep Data in Humans.

    PubMed

    Anderer, Peter

    2015-01-01

    Pharmaco-sleep studies in humans aim at the description of the effects of drugs, most frequently substances that act on the central nervous system, by means of quantitative analysis of biosignals recorded in subjects during sleep. Up to 2007, the only standard for the classification of sleep macrostructure that found worldwide acceptance were the rules published in 1968 by Rechtschaffen and Kales. In May 2007, the AASM Manual for the Scoring of Sleep and Associated Events was published by the American Academy of Sleep Medicine, and concerning the classification of sleep stages, these new rules are supposed to replace those developed by Rechtschaffen and Kales. As compared to the rather low interrater reliability of manual sleep scoring, semiautomated approaches may achieve a reliability close to 1 (Cohen's kappa 0.99 for 2 semiautomated scorings as compared to 0.76 for 2 manual scorings) without any decline in validity. Depending on the aim of the pharmaco-sleep study, additional analyses concerning sleep fragmentation, sleep microstructure, sleep depth, sleep processes and local aspects of sleep should be considered. For some of these additional features, rules for visual scoring have been established, while for others automatic analysis is obligatory. Generally, for reasons of cost-effectiveness but also reliability, automatic analysis is preferable to visual analysis. However, the validity of the automatic method applied has to be proven. PMID:26901054

  11. A Distributed Simulation Facility to Support Human Factors Research in Advanced Air Transportation Technology

    NASA Technical Reports Server (NTRS)

    Amonlirdviman, Keith; Farley, Todd C.; Hansman, R. John, Jr.; Ladik, John F.; Sherer, Dana Z.

    1998-01-01

    A distributed real-time simulation of the civil air traffic environment developed to support human factors research in advanced air transportation technology is presented. The distributed environment is based on a custom simulation architecture designed for simplicity and flexibility in human experiments. Standard Internet protocols are used to create the distributed environment, linking all advanced cockpit simulator, all Air Traffic Control simulator, and a pseudo-aircraft control and simulation management station. The pseudo-aircraft control station also functions as a scenario design tool for coordinating human factors experiments. This station incorporates a pseudo-pilot interface designed to reduce workload for human operators piloting multiple aircraft simultaneously in real time. The application of this distributed simulation facility to support a study of the effect of shared information (via air-ground datalink) on pilot/controller shared situation awareness and re-route negotiation is also presented.

  12. Advanced human machine interaction for an image interpretation workstation

    NASA Astrophysics Data System (ADS)

    Maier, S.; Martin, M.; van de Camp, F.; Peinsipp-Byma, E.; Beyerer, J.

    2016-05-01

    In recent years, many new interaction technologies have been developed that enhance the usability of computer systems and allow for novel types of interaction. The areas of application for these technologies have mostly been in gaming and entertainment. However, in professional environments, there are especially demanding tasks that would greatly benefit from improved human machine interfaces as well as an overall improved user experience. We, therefore, envisioned and built an image-interpretation-workstation of the future, a multi-monitor workplace comprised of four screens. Each screen is dedicated to a complex software product such as a geo-information system to provide geographic context, an image annotation tool, software to generate standardized reports and a tool to aid in the identification of objects. Using self-developed systems for hand tracking, pointing gestures and head pose estimation in addition to touchscreens, face identification, and speech recognition systems we created a novel approach to this complex task. For example, head pose information is used to save the position of the mouse cursor on the currently focused screen and to restore it as soon as the same screen is focused again while hand gestures allow for intuitive manipulation of 3d objects in mid-air. While the primary focus is on the task of image interpretation, all of the technologies involved provide generic ways of efficiently interacting with a multi-screen setup and could be utilized in other fields as well. In preliminary experiments, we received promising feedback from users in the military and started to tailor the functionality to their needs

  13. Advancing human health risk assessment: integrating recent advisory committee recommendations.

    PubMed

    Dourson, Michael; Becker, Richard A; Haber, Lynne T; Pottenger, Lynn H; Bredfeldt, Tiffany; Fenner-Crisp, Penelope A

    2013-07-01

    Over the last dozen years, many national and international expert groups have considered specific improvements to risk assessment. Many of their stated recommendations are mutually supportive, but others appear conflicting, at least in an initial assessment. This review identifies areas of consensus and difference and recommends a practical, biology-centric course forward, which includes: (1) incorporating a clear problem formulation at the outset of the assessment with a level of complexity that is appropriate for informing the relevant risk management decision; (2) using toxicokinetics and toxicodynamic information to develop Chemical Specific Adjustment Factors (CSAF); (3) using mode of action (MOA) information and an understanding of the relevant biology as the key, central organizing principle for the risk assessment; (4) integrating MOA information into dose-response assessments using existing guidelines for non-cancer and cancer assessments; (5) using a tiered, iterative approach developed by the World Health Organization/International Programme on Chemical Safety (WHO/IPCS) as a scientifically robust, fit-for-purpose approach for risk assessment of combined exposures (chemical mixtures); and (6) applying all of this knowledge to enable interpretation of human biomonitoring data in a risk context. While scientifically based defaults will remain important and useful when data on CSAF or MOA to refine an assessment are absent or insufficient, assessments should always strive to use these data. The use of available 21st century knowledge of biological processes, clinical findings, chemical interactions, and dose-response at the molecular, cellular, organ and organism levels will minimize the need for extrapolation and reliance on default approaches. PMID:23844697

  14. Advancing human health risk assessment: Integrating recent advisory committee recommendations

    PubMed Central

    Becker, Richard A.; Haber, Lynne T.; Pottenger, Lynn H.; Bredfeldt, Tiffany; Fenner-Crisp, Penelope A.

    2013-01-01

    Over the last dozen years, many national and international expert groups have considered specific improvements to risk assessment. Many of their stated recommendations are mutually supportive, but others appear conflicting, at least in an initial assessment. This review identifies areas of consensus and difference and recommends a practical, biology-centric course forward, which includes: (1) incorporating a clear problem formulation at the outset of the assessment with a level of complexity that is appropriate for informing the relevant risk management decision; (2) using toxicokinetics and toxicodynamic information to develop Chemical Specific Adjustment Factors (CSAF); (3) using mode of action (MOA) information and an understanding of the relevant biology as the key, central organizing principle for the risk assessment; (4) integrating MOA information into dose–response assessments using existing guidelines for non-cancer and cancer assessments; (5) using a tiered, iterative approach developed by the World Health Organization/International Programme on Chemical Safety (WHO/IPCS) as a scientifically robust, fit-for-purpose approach for risk assessment of combined exposures (chemical mixtures); and (6) applying all of this knowledge to enable interpretation of human biomonitoring data in a risk context. While scientifically based defaults will remain important and useful when data on CSAF or MOA to refine an assessment are absent or insufficient, assessments should always strive to use these data. The use of available 21st century knowledge of biological processes, clinical findings, chemical interactions, and dose–response at the molecular, cellular, organ and organism levels will minimize the need for extrapolation and reliance on default approaches. PMID:23844697

  15. A Framework for Human Performance Criteria for Advanced Reactor Operational Concepts

    SciTech Connect

    Jacques V Hugo; David I Gertman; Jeffrey C Joe

    2014-08-01

    This report supports the determination of new Operational Concept models needed in support of the operational design of new reactors. The objective of this research is to establish the technical bases for human performance and human performance criteria frameworks, models, and guidance for operational concepts for advanced reactor designs. The report includes a discussion of operating principles for advanced reactors, the human performance issues and requirements for human performance based upon work domain analysis and current regulatory requirements, and a description of general human performance criteria. The major findings and key observations to date are that there is some operating experience that informs operational concepts for baseline designs for SFR and HGTRs, with the Experimental Breeder Reactor-II (EBR-II) as a best-case predecessor design. This report summarizes the theoretical and operational foundations for the development of a framework and model for human performance criteria that will influence the development of future Operational Concepts. The report also highlights issues associated with advanced reactor design and clarifies and codifies the identified aspects of technology and operating scenarios.

  16. Introduction of a Rabbit Carotid Artery Model for Sonothrombolysis Research

    PubMed Central

    Fisher, David J.; Ahadi, Golnaz; Voie, Arne

    2012-01-01

    The goal of this study was to develop an in vivo sonothrombolysis model for stroke research. The rabbit carotid artery has average vessel diameters similar to human M1/M2 segments and allows generation of a thrombotic occlusion using various kinds of thrombus material as well as thrombus placement under visual control. It further allows real-time monitoring of flow and clot mechanics during the sonothrombolysis procedure using high-frequency diagnostic ultrasound. In the present study, the model will be introduced and first results to show feasibility using diagnostic as well as high-intensity focused ultrasound will be presented. PMID:23275798

  17. Ultrasonic Imaging of Hemodynamic Force in Carotid Blood Flow

    NASA Astrophysics Data System (ADS)

    Nitta, N.; Homma, K.

    Hemodynamic forces including blood pressure and shear stress affect vulnerable plaque rupture in arteriosclerosis and biochemical activation of endothelium such as NO production. In this study, a method for estimating and imaging shear stress and pressure gradient distributions in blood vessel as the hemodynamic force based on viscosity estimation is presented. Feasibility of this method was investigated by applying to human carotid blood flow. Estimated results of shear stress and pressure gradient distributions coincide with the ideal distributions obtained by numerical simulation and flow-phantom experiment.

  18. Internal carotid artery rupture caused by carotid shunt insertion

    PubMed Central

    Illuminati, Giulio; Caliò, Francesco G.; Pizzardi, Giulia; Vietri, Francesco

    2015-01-01

    Introduction Shunting is a well-accepted method of maintaining cerebral perfusion during carotid endarterectomy (CEA). Nonetheless, shunt insertion may lead to complications including arterial dissection, embolization, and thrombosis. We present a complication of shunt insertion consisting of arterial wall rupture, not reported previously. Presentation of case A 78-year-old woman underwent CEA combined with coronary artery bypass grafting (CABG). At the time of shunt insertion an arterial rupture at the distal tip of the shunt was detected and was repaired via a small saphenous vein patch. Eversion CEA and subsequent CABG completed the procedure whose postoperative course was uneventful. Discussion Shunting during combined CEA-CABG may be advisable to assure cerebral protection from possible hypoperfusion due to potential hemodynamic instability of patients with severe coronary artery disease. Awareness and prompt management of possible shunt-related complications, including the newly reported one, may contribute to limiting their harmful effect. Conclusion Arterial wall rupture is a possible, previously not reported, shunt-related complication to be aware of when performing CEA. PMID:26255001

  19. Carotid endarterectomy and prevention of cerebral ischemia in symptomatic carotid stenosis

    SciTech Connect

    Mayberg, M.R.; Eskridge, J.; Winn, H.R.; Eskridge, J. ); Wilson, S.E. ); Yatsu, F. ); Weiss, D.G. ); Messina, L. ); Hershey, L.A. ); Colling, C. ); Deykin, D. )

    1991-12-18

    The objective of this study was to determine whether carotid endarterectomy provides protection against subsequent cerebral ischemia in men with ischemic symptoms in the distribution of significant ipsilateral internal carotid artery stenosis. The study group was comprised of men who presented within 120 days of onset of symptoms that were consistent with transient ischemic attacks, transient monocular blindness, or recent small completed strokes between July 1988 and February 1991. Among 5,000 patients screened, 189 individuals were randomized with angiographic internal carotid artery stenosis greater than 50% ipsilateral to the presenting symptoms. Forty-eight eligible patients who refused entry were followed up outside of the trial. For a selected cohort of men with symptoms of cerebral or retinal ischemia in the distribution of a high-grade internal carotid artery stenosis, carotid endarterectomy can effectively reduce the risk of subsequent ipsilateral cerebral ischemia. The risk of cerebral ischemia in this subgroup of patients is considerably higher than previously estimated.

  20. Oculoplethysmography and carotid phonoangiography for the noninvasive detection of extracranial carotid occlusive disease.

    PubMed

    McRae, L P; Cadwallader, J A; Kartchner, M M

    1979-01-01

    Clinical applications of imaging techniques and noninvasive physiological vascular evaluations provide useful assistance in the detection and management of stroke-prone patients by minimizing unnecessary carotid arteriography and surgery. Two such evaluation techniques are oculoplethysmography (OPG) and carotid phonoangiography (CPA). Developed, used, and proved highly reliable at the Tucson (Arizona) Medical Center, the techniques have been documented in 12,000 tests on approximately 8500 patients. OPG simultaneously records the bilateral ocular pulses concomitantly with external carotid pulses. Delays in timing of these pulses reflect reduction of flow in the internal and/or external carotid arteries, respectively. CPA consists of electronic stethoscopic auscultation, direct visualization, and photographic recording of carotid bruits or blood flow sounds.

  1. Perspectives on the Development and Future of Advanced Placement® Human Geography

    ERIC Educational Resources Information Center

    Hildebrant, Barbara

    2016-01-01

    Advanced Placement (AP) Human Geography faced a number of hurdles that nearly derailed the course before it launched in 2000-2001. A dedicated cadre of geography professionals and high school teachers rose to the challenge and the course remains one of the fastest growing AP courses currently offered by College Board. Seventeen readers and leaders…

  2. Placing Advanced Placement® Human Geography: Its Role in U.S. Geography Education

    ERIC Educational Resources Information Center

    Bednarz, Sarah Witham

    2016-01-01

    This article examines Advanced Placement Human Geography (AP HG) in the context of its place in efforts to reform geography education. It presents a critical analysis of the AP program and its curriculum, asserting that it represents "powerful knowledge" as conceptualized by Young. It concludes with a call for research in AP HG aligned…

  3. Familial advanced sleep-phase syndrome: A short-period circadian rhythm variant in humans.

    PubMed

    Jones, C R; Campbell, S S; Zone, S E; Cooper, F; DeSano, A; Murphy, P J; Jones, B; Czajkowski, L; Ptácek, L J

    1999-09-01

    Biological circadian clocks oscillate with an approximately 24-hour period, are ubiquitous, and presumably confer a selective advantage by anticipating the transitions between day and night. The circadian rhythms of sleep, melatonin secretion and body core temperature are thought to be generated by the suprachiasmatic nucleus of the hypothalamus, the anatomic locus of the mammalian circadian clock. Autosomal semi-dominant mutations in rodents with fast or slow biological clocks (that is, short or long endogenous period lengths; tau) are associated with phase-advanced or delayed sleep-wake rhythms, respectively. These models predict the existence of familial human circadian rhythm variants but none of the human circadian rhythm disorders are known to have a familial tendency. Although a slight 'morning lark' tendency is common, individuals with a large and disabling sleep phase-advance are rare. This disorder, advanced sleep-phase syndrome, is characterized by very early sleep onset and offset; only two cases are reported in young adults. Here we describe three kindreds with a profound phase advance of the sleep-wake, melatonin and temperature rhythms associated with a very short tau. The trait segregates as an autosomal dominant with high penetrance. These kindreds represent a well-characterized familial circadian rhythm variant in humans and provide a unique opportunity for genetic analysis of human circadian physiology. PMID:10470086

  4. Reducing the Human Burden of Breast Cancer: Advanced Radiation Therapy Yields Improved Treatment Outcomes.

    PubMed

    Currey, Adam D; Bergom, Carmen; Kelly, Tracy R; Wilson, J Frank

    2015-01-01

    Radiation therapy is an important modality in the treatment of patients with breast cancer. While its efficacy in the treatment of breast cancer was known shortly after the discovery of x-rays, significant advances in radiation delivery over the past 20 years have resulted in improved patient outcomes. With the development of improved systemic therapy, optimizing local control has become increasingly important and has been shown to improve survival. Better understanding of the magnitude of treatment benefit, as well as patient and biological factors that confer an increased recurrence risk, have allowed radiation oncologists to better tailor treatment decisions to individual patients. Furthermore, significant technological advances have occurred that have reduced the acute and long-term toxicity of radiation treatment. These advances continue to reduce the human burden of breast cancer. It is important for radiation oncologists and nonradiation oncologists to understand these advances, so that patients are appropriately educated about the risks and benefits of this important treatment modality.

  5. Obesity and carotid artery remodeling

    PubMed Central

    Kozakova, M; Palombo, C; Morizzo, C; Højlund, K; Hatunic, M; Balkau, B; Nilsson, P M; Ferrannini, E

    2015-01-01

    Background/Objective: The present study tested the hypothesis that obesity-related changes in carotid intima-media thickness (IMT) might represent not only preclinical atherosclerosis but an adaptive remodeling meant to preserve circumferential wall stress (CWS) in altered hemodynamic conditions characterized by body size-dependent increase in stroke volume (SV) and blood pressure (BP). Subjects/Methods: Common carotid artery (CCA) luminal diameter (LD), IMT and CWS were measured in three different populations in order to study: (A) cross-sectional associations between SV, BP, anthropometric parameters and CCA LD (266 healthy subjects with wide range of body weight (24–159 kg)); (B) longitudinal associations between CCA LD and 3-year IMT progression rate (ΔIMT; 571 healthy non-obese subjects without increased cardiovascular (CV) risk); (C) the impact of obesity on CCA geometry and CWS (88 obese subjects without CV complications and 88 non-obese subjects matched for gender and age). Results: CCA LD was independently associated with SV that was determined by body size. In the longitudinal study, baseline LD was an independent determinant of ΔIMT, and ΔIMT of subjects in the highest LD quartile was significantly higher (28±3 μm) as compared with those in the lower quartiles (8±3, 16±4 and 16±3 μm, P=0.001, P<0.05 and P=0.01, respectively). In addition, CCA CWS decreased during the observational period in the highest LD quartile (from 54.2±8.6 to 51.6±7.4 kPa, P<0.0001). As compared with gender- and age-matched lean individuals, obese subjects had highly increased CCA LD and BP (P<0.0001 for both), but only slightly higher CWS (P=0.05) due to a significant increase in IMT (P=0.005 after adjustment for confounders). Conclusions: Our findings suggest that in obese subjects, the CCA wall thickens to compensate the luminal enlargement caused by body size-induced increase in SV, and therefore, to normalize the wall stress. CCA diameter in obesity could

  6. Interaction of the carotid baroreflex, the muscle chemoreflex and the cardiopulmonary baroreflex in man during exercise

    NASA Technical Reports Server (NTRS)

    Eiken, O.; Convertino, V. A.; Doerr, D. F.; Dudley, G. A.; Morariu, G.; Mekjavic, I. B.

    1991-01-01

    The interaction of the muscle chemoreflex and the cardiopulmonary baroreflex with the carotid baroreflex in humans performing exercise was investigated in healthy subjects using specially designed exercise regimen and apparatus. Stimulation of the muscle chemoreflex was achieved by restricting blood flow in the exercising muscles by means of applying a pressure of 50 mm Hg, whereas cardiopulmonary baroreceptors were unloaded by employing LBNP of -20 mm Hg. The carotid baroreceptors were unloaded and stimulated by neck-pressure maneuvers (Sprenkle et al., 1986). Results showed that the cardiodecelerating capacity of the carotid baroreflex remains active during exercise, and may even be sensitized by the chemoreflex-induced increase in arterial pressure; but it is not affected by the cardiopulmonary baroreceptor activity.

  7. Workshop on Critical Issues in Microgravity Fluids, Transport, and Reaction Processes in Advanced Human Support Technology

    NASA Technical Reports Server (NTRS)

    Chiaramonte, Francis P.; Joshi, Jitendra A.

    2004-01-01

    This workshop was designed to bring the experts from the Advanced Human Support Technologies communities together to identify the most pressing and fruitful areas of research where success hinges on collaborative research between the two communities. Thus an effort was made to bring together experts in both advanced human support technologies and microgravity fluids, transport and reaction processes. Expertise was drawn from academia, national laboratories, and the federal government. The intent was to bring about a thorough exchange of ideas and develop recommendations to address the significant open design and operation issues for human support systems that are affected by fluid physics, transport and reaction processes. This report provides a summary of key discussions, findings, and recommendations.

  8. Advances in Robotic, Human, and Autonomous Systems for Missions of Space Exploration

    NASA Technical Reports Server (NTRS)

    Gross, Anthony R.; Briggs, Geoffrey A.; Glass, Brian J.; Pedersen, Liam; Kortenkamp, David M.; Wettergreen, David S.; Nourbakhsh, I.; Clancy, Daniel J.; Zornetzer, Steven (Technical Monitor)

    2002-01-01

    Space exploration missions are evolving toward more complex architectures involving more capable robotic systems, new levels of human and robotic interaction, and increasingly autonomous systems. How this evolving mix of advanced capabilities will be utilized in the design of new missions is a subject of much current interest. Cost and risk constraints also play a key role in the development of new missions, resulting in a complex interplay of a broad range of factors in the mission development and planning of new missions. This paper will discuss how human, robotic, and autonomous systems could be used in advanced space exploration missions. In particular, a recently completed survey of the state of the art and the potential future of robotic systems, as well as new experiments utilizing human and robotic approaches will be described. Finally, there will be a discussion of how best to utilize these various approaches for meeting space exploration goals.

  9. Effect of bilateral carotid body resection on cardiac baroreflex control of blood pressure during hypoglycemia.

    PubMed

    Limberg, Jacqueline K; Taylor, Jennifer L; Mozer, Michael T; Dube, Simmi; Basu, Ananda; Basu, Rita; Rizza, Robert A; Curry, Timothy B; Joyner, Michael J; Wehrwein, Erica A

    2015-06-01

    Hypoglycemia results in a reduction in cardiac baroreflex sensitivity and a shift in the baroreflex working range to higher heart rates. This effect is mediated, in part, by the carotid chemoreceptors. Therefore, we hypothesized hypoglycemia-mediated changes in baroreflex control of heart rate would be blunted in carotid body-resected patients when compared with healthy controls. Five patients with bilateral carotid body resection for glomus tumors and 10 healthy controls completed a 180-minute hyperinsulinemic, hypoglycemic (≈3.3 mmol/L) clamp. Changes in heart rate, blood pressure, and spontaneous cardiac baroreflex sensitivity were assessed. Baseline baroreflex sensitivity was not different between groups (P>0.05). Hypoglycemia resulted in a reduction in baroreflex sensitivity in both the groups (main effect of time, P<0.01) and responses were lower in resected patients when compared with controls (main effect of group, P<0.05). Hypoglycemia resulted in large reductions in systolic (-17±7 mm Hg) and mean (-14±5 mm Hg) blood pressure in resected patients that were not observed in controls (interaction of group and time, P<0.05). Despite lower blood pressures, increases in heart rate with hypoglycemia were blunted in resected patients (interaction of group and time, P<0.01). Major novel findings from this study demonstrate that intact carotid chemoreceptors are essential for increasing heart rate and maintaining arterial blood pressure during hypoglycemia in humans. These data support a contribution of the carotid chemoreceptors to blood pressure control and highlight the potential widespread effects of carotid body resection in humans.

  10. Who Is at Risk for Carotid Artery Disease?

    MedlinePlus

    ... Prevention Living With Clinical Trials Links Related Topics Atherosclerosis Carotid Endarterectomy Carotid Ultrasound Stents Stroke Send a ... who don’t have diabetes. Family history of atherosclerosis . People who have a family history of atherosclerosis ...

  11. MIGRAINE, CAROTID STIFFNESS AND GENETIC POLYMORPHISM.

    PubMed

    Kes, Vanja Basić; Jurasić, Miljenka-Jelena; Zavoreo, Iris; Corić, Lejla; Rotim, Kresimir

    2015-12-01

    Recently migraine has been associated with increased arterial stiffness, procoagulant state, increased incidence of cerebral white matter lesions (WML) and stroke. Our aim was to compare the characteristics of migraineurs to headache free controls regarding their functional carotid ultrasound parameters. Sixty patients (45 women) with migraine (mean age 40.42 ± 10.61 years) were compared with 45 controls (30 women) with no prior history of repeating headache (mean age 38.94 ± 5.46 years) using E-tracking software on Alpha 10 ultrasound platform. Student's t-test was used on statistical analysis with alpha < 0.05. All tested carotid vascular parameters were worse in patients with migraine including increased intima-media thickness, greater carotid diameter and carotid diameter change, as well as several arterial stiffness indices. Additionally, patients with migraine had greater incidence of homozygous mutations for procoagulant genes (MTHFR (C677T), PAI-1 and ACE I/D) than expected. Computed tomography and magnetic resonance imaging of the brain showed WML in 11 patients, four of them migraine with aura patients. Since we established increased carotid stiffness and higher frequency of procoagulant gene mutations in migraineurs, we propose prospective ultrasound monitoring in such patients, especially those with detected WML, in order to timely commence more active and specific preventive stroke management strategies.

  12. Carotid artery disease following external cervical irradiation.

    PubMed Central

    Elerding, S C; Fernandez, R N; Grotta, J C; Lindberg, R D; Causay, L C; McMurtrey, M J

    1981-01-01

    A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head an neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population observed over the same period of time (p = 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult. PMID:7294930

  13. Carotid intraplaque neovascularization quantification software (CINQS).

    PubMed

    Akkus, Zeynettin; van Burken, Gerard; van den Oord, Stijn C H; Schinkel, Arend F L; de Jong, Nico; van der Steen, Antonius F W; Bosch, Johan G

    2015-01-01

    Intraplaque neovascularization (IPN) is an important biomarker of atherosclerotic plaque vulnerability. As IPN can be detected by contrast enhanced ultrasound (CEUS), imaging-biomarkers derived from CEUS may allow early prediction of plaque vulnerability. To select the best quantitative imaging-biomarkers for prediction of plaque vulnerability, a systematic analysis of IPN with existing and new analysis algorithms is necessary. Currently available commercial contrast quantification tools are not applicable for quantitative analysis of carotid IPN due to substantial motion of the carotid artery, artifacts, and intermittent perfusion of plaques. We therefore developed a specialized software package called Carotid intraplaque neovascularization quantification software (CINQS). It was designed for effective and systematic comparison of sets of quantitative imaging biomarkers. CINQS includes several analysis algorithms for carotid IPN quantification and overcomes the limitations of current contrast quantification tools and existing carotid IPN quantification approaches. CINQS has a modular design which allows integrating new analysis tools. Wizard-like analysis tools and its graphical-user-interface facilitate its usage. In this paper, we describe the concept, analysis tools, and performance of CINQS and present analysis results of 45 plaques of 23 patients. The results in 45 plaques showed excellent agreement with visual IPN scores for two quantitative imaging-biomarkers (The area under the receiver operating characteristic curve was 0.92 and 0.93). PMID:25561454

  14. Human-System Safety Methods for Development of Advanced Air Traffic Management Systems

    SciTech Connect

    Nelson, W.R.

    1999-05-24

    The Idaho National Engineering and Environmental Laboratory (INEEL) is supporting the National Aeronautics and Space Administration in the development of advanced air traffic management (ATM) systems as part of the Advanced Air Transportation Technologies program. As part of this program INEEL conducted a survey of human-system safety methods that have been applied to complex technical systems, to identify lessons learned from these applications and provide recommendations for the development of advanced ATM systems. The domains that were surveyed included offshore oil and gas, commercial nuclear power, commercial aviation, and military. The survey showed that widely different approaches are used in these industries, and that the methods used range from very high-level, qualitative approaches to very detailed quantitative methods such as human reliability analysis (HRA) and probabilistic safety assessment (PSA). In addition, the industries varied widely in how effectively they incorporate human-system safety assessment in the design, development, and testing of complex technical systems. In spite of the lack of uniformity in the approaches and methods used, it was found that methods are available that can be combined and adapted to support the development of advanced air traffic management systems.

  15. Effects of an Advanced Reactor’s Design, Use of Automation, and Mission on Human Operators

    SciTech Connect

    Jeffrey C. Joe; Johanna H. Oxstrand

    2014-06-01

    The roles, functions, and tasks of the human operator in existing light water nuclear power plants (NPPs) are based on sound nuclear and human factors engineering (HFE) principles, are well defined by the plant’s conduct of operations, and have been validated by years of operating experience. However, advanced NPPs whose engineering designs differ from existing light-water reactors (LWRs) will impose changes on the roles, functions, and tasks of the human operators. The plans to increase the use of automation, reduce staffing levels, and add to the mission of these advanced NPPs will also affect the operator’s roles, functions, and tasks. We assert that these factors, which do not appear to have received a lot of attention by the design engineers of advanced NPPs relative to the attention given to conceptual design of these reactors, can have significant risk implications for the operators and overall plant safety if not mitigated appropriately. This paper presents a high-level analysis of a specific advanced NPP and how its engineered design, its plan to use greater levels of automation, and its expanded mission have risk significant implications on operator performance and overall plant safety.

  16. Human Factors Engineering (HFE) insights for advanced reactors based upon operating experience

    SciTech Connect

    Higgins, J.; Nasta, K.

    1997-01-01

    The NRC Human Factors Engineering Program Review Model (HFE PRM, NUREG-0711) was developed to support a design process review for advanced reactor design certification under 10CFR52. The HFE PRM defines ten fundamental elements of a human factors engineering program. An Operating Experience Review (OER) is one of these elements. The main purpose of an OER is to identify potential safety issues from operating plant experience and ensure that they are addressed in a new design. Broad-based experience reviews have typically been performed in the past by reactor designers. For the HFE PRM the intent is to have a more focussed OER that concentrates on HFE issues or experience that would be relevant to the human-system interface (HSI) design process for new advanced reactors. This document provides a detailed list of HFE-relevant operating experience pertinent to the HSI design process for advanced nuclear power plants. This document is intended to be used by NRC reviewers as part of the HFE PRM review process in determining the completeness of an OER performed by an applicant for advanced reactor design certification. 49 refs.

  17. Complications of cerebral angiography in patients with symptomatic carotid territory ischaemia screened by carotid ultrasound.

    PubMed Central

    Davies, K N; Humphrey, P R

    1993-01-01

    After nearly 40 years, carotid endarterectomy has been shown to be of benefit to patients with symptomatic carotid territory ischaemia and greater than 70% stenosis of the relevant internal carotid artery. Cerebral angiography is performed before surgery and is not without risk. These risks must be added to those of surgery before recommending the procedure to patients. The study evaluated the local, systemic and neurological complications following digital subtraction angiography with selective catheterisation of the carotid arteries in 200 patients presenting to a cerebrovascular clinic for assessment of cerebral ischaemia. All patients had carotid ultrasound screening before angiography to screen out those with normal arteries or mild disease (less than 30% stenosis of symptomatic internal carotid artery). Complications occurred in 28 patients. There were six (3%) local, two (1%) systemic and 20 (10%) neurological complications. Seventeen neurological complications occurred within 24 hours and there were three late complications (24-72 hours). Neurological complications occurred more frequently when angiography was performed by a trainee rather than a consultant neuroradiologist (p < 0.01). The neurological complications were transient (resolved within 24 hours) in 10/200 (5%), reversible (resolved within seven days) in two (1%) and permanent in 8/200 (4%). Two patients died after a stroke and two other patients suffered a disabling stroke. At 24 hours post angiography the permanent (persisting beyond seven days) neurological complication rate was 2.5%. The incidence of total neurological complications and post angiographic strokes was higher in patients with greater than 90% stenosis of the symptomatic internal carotid artery (p < 0.001). The increased use of non-invasive Doppler duplex screening will reduced the absolute number of patients put at risk of angiography, yet the rate of post angiographic complications is likely to increase as patients with severe

  18. Safety Outcomes Using a Proximal Protection Device in Carotid Stenting of Long Carotid Stenoses

    PubMed Central

    Atchaneeyasakul, Kunakorn; Khandelwal, Priyank; Ambekar, Sudheer; Ramdas, Kevin; Guada, Luis; Yavagal, Dileep

    2016-01-01

    Background Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. Objective We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. Methods This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. Results From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. Conclusion In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign.

  19. ULTRASTRUCTURE OF THE CAROTID BODY

    PubMed Central

    Biscoe, T. J.; Stehbens, W. E.

    1966-01-01

    An electron microscope investigation was made of the carotid body in the cat and the rabbit. In thin-walled blood vessels the endothelium was fenestrated. Larger vessels were surrounded by a layer of smooth muscle fibers. Among the numerous blood vessels lay groups of cells of two types covered by basement membranes. Aggregates of Type I cells were invested by Type II cells, though occasionally cytoplasmic extensions were covered by basement membrane only. Type I cells contained many electron-opaque cored vesicles (350 to 1900 A in diameter) resembling those in endocrine secretory cells. Type II cells covered nerve endings terminating on Type I cells and enclosed nerve fibers in much the same manner as Schwann cells. The nerve endings contained numerous microvesicles (∼500 A in diameter), mitochondria, glycogen granules, and a few electron-opaque cored vesicles. Junctions between nerve endings and Type I cells were associated with regions of increased density in both intercellular spaces and the adjoining cytoplasm. Cilia of the 9 + 0 fibril pattern were observed in Type I and Type II cells and pericytes. Nonmyelinated nerve fibers, often containing microvesicles, mitochondria, and a few electron-opaque cored vesicles (650 to 1000 A in diameter) were present in Schwann cells, many of which were situated close to blood vessels Ganglion cells near the periphery of the gland, fibrocytes, and segments of unidentified cells were also seen. It was concluded that, according to present concepts of the structure of nerve endings, those endings related to Type I cells could be efferent or afferent. PMID:5971007

  20. Carotid Baroreflex Function During Prolonged Exercise

    NASA Technical Reports Server (NTRS)

    Raven, P. B.

    1999-01-01

    Astronauts are often required to work (exercise) at moderate to high intensities for extended periods while performing extra-vehicular activities (EVA). Although the physiologic responses associated with prolonged exercise have been documented, the mechanisms involved in blood pressure regulation under these conditions have not yet been fully elucidated. An understanding of this issue is pertinent to the ability of humans to perform work in microgravity and complies with the emphasis of NASA's Space Physiology and Countermeasures Program. Prolonged exercise at a constant workload is know to result in a progressive decrease in mean arterial pressure (MAP) concomitant with a decrease in stroke volume and a compensatory increase in heart rate. The continuous decrease in MAP during the exercise, which is related to the thermoregulatory redistribution of circulating blood volume to the cutaneous circulation, raises the question as to whether there is a loss of baroreflex regulation of arterial blood pressure. We propose that with prolongation of the exercise to 60 minutes, progressive increases on central command reflect a progressive upward resetting of the carotid baroreflex (CBR) such that the operating point of the CBR is shifted to a pressure below the threshold of the reflex rendering it ineffectual in correcting the downward drift in MAP. In order to test this hypothesis, experiments have been designed to uncouple the global hemodynamic response to prolonged exercise from the central command mediated response via: (1) continuous maintenance of cardiac filling volume by intravenous infusion of a dextran solution; and (2) whole body surface cooling to counteract thermoregulatory cutaneous vasodialation. As the type of work (exercise) performed by astronauts is inherently arm and upper body dependent, we will also examine the physiologic responses to prolonged leg cycling and arm ergometry exercise in the supine positions with and without level lower body negative

  1. Current management of asymptomatic carotid stenosis.

    PubMed

    Castilla-Guerra, L; Fernández-Moreno, M C; Serrano-Rodríguez, L

    2015-05-01

    Asymptomatic carotid stenosis (ACS) is a common problem in daily clinical practice, and its management is still the subject of controversy. In contrast to symptomatic carotid disease, the main studies on surgical treatment of patients with ACS have shown only a modest benefit in the primary prevention of stroke. In addition, current medical treatment has drastically decreased the risk of stroke in patients with ACS. Selecting patients amenable to endovascular treatment and determining how and when to conduct the ultrasound follow-up of these patients are issues that still need resolving. This article analyzes two new studies underway that provide evidence for better management of ACS in daily clinical practice.

  2. Finite element analysis of mechanics of neovessels with intraplaque hemorrhage in carotid atherosclerosis

    PubMed Central

    2015-01-01

    Background Intraplaque hemorrhage is a widely known factor facilitating plaque instability. Neovascularization of plaque can be regarded as a compensatory response to the blood supply in the deep intimal and medial areas of the artery. Due to the physiological function, the deformation of carotid atherosclerotic plaque would happen under the action of blood pressure and blood flow. Neovessels are subject to mechanical loading and likely undergo deformation. The rupture of neovessels may deteriorate the instability of plaque. This study focuses on the local mechanical environments around neovessels and investigates the relationship between the biomechanics and the morphological specificity of neovessels. Methods Stress and stretch were used to evaluate the rupture risk of the neovessels in plaque. Computational structural analysis was performed based on two human carotid plaque slice samples. Two-dimensional models containing neovessels and other components were built according to the plaque slice samples. Each component was assumed to be non-linear isotropic, piecewise homogeneous and incompressible. Different mechanical boundary conditions, i.e. static pressures, were imposed in the carotid lumen and neovessels lumen respectively. Finite element method was used to simulate the mechanical conditions in the atherosclerotic plaque. Results Those neovessels closer to the carotid lumen undergo larger stress and stretch. With the same distance to the carotid lumen, the longer the perimeter of neovessels is, the larger stress and the deformation of the neovessels will be. Under the same conditions, the neovessels with larger curvature suffer greater stress and stretch. Neovessels surrounded by red blood cells undergo a much larger stretch. Conclusions Local mechanical conditions may result in the hemorrhage of neovessels and accelerate the rupture of plaque. The mechanical environments of the neovessel are related to its shape, curvature, distance to the carotid lumen

  3. Some inadequacies of the current human factors certification process of advanced aircraft technologies

    NASA Technical Reports Server (NTRS)

    Paries, Jean

    1994-01-01

    Automation related accidents or serious incidents are not limited to advanced technology aircraft. There is a full history of such accidents with conventional technology aircraft. However, this type of occurrence is far from sparing the newest 'glass cockpit' generation, and it even seems to be a growing contributor to its accident rate. Nevertheless, all these aircraft have been properly certificated according to the relevant airworthiness regulations. Therefore, there is a growing concern that with the technological advancement of air transport aircraft cockpits, the current airworthiness regulations addressing cockpit design and human factors may have reached some level of inadequacy. This paper reviews some aspects of the current airworthiness regulations and certification process related to human factors of cockpit design and focuses on questioning their ability to guarantee the intended safety objectives.

  4. Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

    SciTech Connect

    Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

    1987-01-01

    This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

  5. Open Innovation at NASA: A New Business Model for Advancing Human Health and Performance Innovations

    NASA Technical Reports Server (NTRS)

    Davis, Jeffrey R.; Richard, Elizabeth E.; Keeton, Kathryn E.

    2014-01-01

    This paper describes a new business model for advancing NASA human health and performance innovations and demonstrates how open innovation shaped its development. A 45 percent research and technology development budget reduction drove formulation of a strategic plan grounded in collaboration. We describe the strategy execution, including adoption and results of open innovation initiatives, the challenges of cultural change, and the development of virtual centers and a knowledge management tool to educate and engage the workforce and promote cultural change.

  6. Carotid Body Tumor as a Cause of Stroke.

    PubMed

    Budincevic, Hrvoje; Piršic, Ana; Bohm, Tihana; Trajbar, Tomislav; Ivkošic, Ante; Pavlovic, Tomislav; Bielen, Ivan; Soldo-Butkovic, Silva

    2016-01-01

    We herein report a case of a 78-year-old woman who was admitted to our hospital due to a stroke with left-sided hemiparesis. Ultrasound of the carotid arteries showed a carotid body tumor on the bifurcation of the right common carotid artery, which was subsequently confirmed by a further neuroradiological investigation. Magnetic resonance imaging of the head confirmed an acute ischemic lesion located in the right periventricular region. The carotid body tumor (CBT) was surgically removed and confirmed on histopathology. Our case reveals the role of carotid ultrasound in the diagnosis of a CBT, which may be a potential cause of stroke. PMID:26831027

  7. Occipital infarction with hemianopsia from carotid occlusive disease.

    PubMed

    Pessin, M S; Kwan, E S; Scott, R M; Hedges, T R

    1989-03-01

    Extracranial internal carotid artery occlusive disease usually produces stroke in the middle cerebral artery territory or the border zone between the middle and anterior cerebral arteries. It is unusual for occipital infarction in the posterior cerebral artery territory to be caused by internal carotid artery disease despite the fact that the posterior cerebral artery may arise directly from the internal carotid artery as an anatomic variation. We describe a patient with a fetal posterior cerebral artery originating from the internal carotid artery, and the initial manifestation of his extracranial internal carotid artery occlusive disease was hemianopsia from occipital infarction.

  8. Recent Advances in Understanding the Role of Nutrition in Human Genome Evolution12

    PubMed Central

    Ye, Kaixiong; Gu, Zhenglong

    2011-01-01

    Dietary transitions in human history have been suggested to play important roles in the evolution of mankind. Genetic variations caused by adaptation to diet during human evolution could have important health consequences in current society. The advance of sequencing technologies and the rapid accumulation of genome information provide an unprecedented opportunity to comprehensively characterize genetic variations in human populations and unravel the genetic basis of human evolution. Series of selection detection methods, based on various theoretical models and exploiting different aspects of selection signatures, have been developed. Their applications at the species and population levels have respectively led to the identification of human specific selection events that distinguish human from nonhuman primates and local adaptation events that contribute to human diversity. Scrutiny of candidate genes has revealed paradigms of adaptations to specific nutritional components and genome-wide selection scans have verified the prevalence of diet-related selection events and provided many more candidates awaiting further investigation. Understanding the role of diet in human evolution is fundamental for the development of evidence-based, genome-informed nutritional practices in the era of personal genomics. PMID:22332091

  9. Serum soluble RAGE levels and carotid atherosclerosis: the Northern Manhattan Study (NOMAS)

    PubMed Central

    Hudson, Barry I; Gardener, Hannah; Liu-Mares, Wen; Dong, Chuanhui; Cheung, Ken; Elkind, Mitchell SV; Wright, Clinton B; Sacco, Ralph L; Rundek, Tatjana

    2016-01-01

    Background Recent cohort studies suggested that serum levels of soluble Receptor for Advanced Glycation End-products (sRAGE) are associated with the risk of cardiovascular disease. We hypothesized that sRAGE levels are associated with subclinical atherosclerosis in a racially and ethnically diverse population. Methods and results 828 stroke-free participants from the Northern Manhattan Study (mean age 71.1±8.7yrs; 64% Hispanic, 19% black, and 17% white) underwent high-resolution carotid B-mode ultrasound to measure carotid plaque (present in 62% of subjects) and intima-media thickness (IMT) (mean Total= 0.96±0.10 mm). Serum sRAGE was measured by ELISA and associations tested between sRAGE with IMT and plaque presence. Soluble RAGE levels were not associated with plaque presence or IMT after adjusting for sociodemographic, vascular risk factors and medication use. Stratification by race-ethnicity did not reveal any associations with carotid IMT or plaque. Conclusion In the present study, sRAGE levels were not associated with carotid atherosclerosis. PMID:25744702

  10. Tasting arterial blood: what do the carotid chemoreceptors sense?

    PubMed Central

    Prabhakhar, Nanduri R.; Joyner, Michael J.

    2015-01-01

    The carotid bodies are sensory organs that detect the chemical composition of the arterial blood. The carotid body sensory activity increases in response to arterial hypoxemia and the ensuing chemoreflex regulates vital homeostatic functions. Recent studies suggest that the carotid bodies might also sense arterial blood glucose and circulating insulin levels. This review focuses on how the carotid bodies sense O2, glucose, and insulin and some potential implications of these sensory functions on physiological regulation and in pathophysiological conditions. Emerging evidence suggests that carbon monoxide (CO)-regulated hydrogen sulfide (H2S), stemming from hypoxia, depolarizes type I cells by inhibiting certain K+ channels, facilitates voltage-gated Ca2+ influx leading to sensory excitation of the carotid body. Elevated CO and decreased H2S renders the carotid bodies insensitive to hypoxia resulting in attenuated ventilatory adaptations to high altitude hypoxia, whereas reduced CO and high H2S result in hypersensitivity of the carotid bodies to hypoxia and hypertension. Acute hypoglycemia augments the carotid body responses to hypoxia but that a prolonged lack of glucose in the carotid bodies can lead to a failure to sense hypoxia. Emerging evidence also indicates that carotid bodies might sense insulin directly independent of its effect on glucose, linking the carotid bodies to the pathophysiological consequences of the metabolic syndrome. How glucose and insulin interact with the CO-H2S signaling is an area of ongoing study. PMID:25642193

  11. Tasting arterial blood: what do the carotid chemoreceptors sense?

    PubMed

    Prabhakhar, Nanduri R; Joyner, Michael J

    2014-01-01

    The carotid bodies are sensory organs that detect the chemical composition of the arterial blood. The carotid body sensory activity increases in response to arterial hypoxemia and the ensuing chemoreflex regulates vital homeostatic functions. Recent studies suggest that the carotid bodies might also sense arterial blood glucose and circulating insulin levels. This review focuses on how the carotid bodies sense O2, glucose, and insulin and some potential implications of these sensory functions on physiological regulation and in pathophysiological conditions. Emerging evidence suggests that carbon monoxide (CO)-regulated hydrogen sulfide (H2S), stemming from hypoxia, depolarizes type I cells by inhibiting certain K(+) channels, facilitates voltage-gated Ca(2+) influx leading to sensory excitation of the carotid body. Elevated CO and decreased H2S renders the carotid bodies insensitive to hypoxia resulting in attenuated ventilatory adaptations to high altitude hypoxia, whereas reduced CO and high H2S result in hypersensitivity of the carotid bodies to hypoxia and hypertension. Acute hypoglycemia augments the carotid body responses to hypoxia but that a prolonged lack of glucose in the carotid bodies can lead to a failure to sense hypoxia. Emerging evidence also indicates that carotid bodies might sense insulin directly independent of its effect on glucose, linking the carotid bodies to the pathophysiological consequences of the metabolic syndrome. How glucose and insulin interact with the CO-H2S signaling is an area of ongoing study. PMID:25642193

  12. Evidence-based surgical treatment of carotid stenosis. Literature review.

    PubMed

    Andaluz, N; Zuccarello, M

    2004-03-01

    Carotid stenosis is an important cause of transient ischemic attacks and stroke. The cause of carotid stenosis is most often atherosclerosis, which accounts for 10% to 20% of brain infarction cases. Despite the introduction of tissue-plasminogen activator and other promising experimental therapies for select patients with acute ischemic stroke prevention remains the best approach to reduce its impact. Stroke-prone patients can be identified and targeted for specific interventions. At this juncture, treatment of carotid stenosis is a well-established therapeutic target and a pillar of stroke prevention. Two main strategies exist for the treatment of carotid stenosis. The 1st is stabilization or halting the progression of the carotid plaque formation with medications and modifications of risk factors (e.g., hypertension, diabetes, smoking, obesity, high cholesterol). The 2nd approach is the elimination or reduction of carotid stenosis by carotid endarterectomy or angioplasty and stenting. Carotid endarterectomy is the mainstay of therapy for symptomatic, severe carotid stenosis. Although its role for asymptomatic patients appears more limited, it is distinct for severe stenosis. Carotid angioplasty and stenting are techniques in maturation with the attractiveness of being less invasive that face the challenge of at least replicating the results of surgery. In this article, we will discuss the surgical management of symptomatic and asymptomatic carotid stenosis based on the evidence provided by the literature. PMID:15257259

  13. Oxygen sensing by the carotid body: mechanisms and role in adaptation to hypoxia.

    PubMed

    López-Barneo, José; González-Rodríguez, Patricia; Gao, Lin; Fernández-Agüera, M Carmen; Pardal, Ricardo; Ortega-Sáenz, Patricia

    2016-04-15

    Oxygen (O2) is fundamental for cell and whole-body homeostasis. Our understanding of the adaptive processes that take place in response to a lack of O2(hypoxia) has progressed significantly in recent years. The carotid body (CB) is the main arterial chemoreceptor that mediates the acute cardiorespiratory reflexes (hyperventilation and sympathetic activation) triggered by hypoxia. The CB is composed of clusters of cells (glomeruli) in close contact with blood vessels and nerve fibers. Glomus cells, the O2-sensitive elements in the CB, are neuron-like cells that contain O2-sensitive K(+)channels, which are inhibited by hypoxia. This leads to cell depolarization, Ca(2+)entry, and the release of transmitters to activate sensory fibers terminating at the respiratory center. The mechanism whereby O2modulates K(+)channels has remained elusive, although several appealing hypotheses have been postulated. Recent data suggest that mitochondria complex I signaling to membrane K(+)channels plays a fundamental role in acute O2sensing. CB activation during exposure to low Po2is also necessary for acclimatization to chronic hypoxia. CB growth during sustained hypoxia depends on the activation of a resident population of stem cells, which are also activated by transmitters released from the O2-sensitive glomus cells. These advances should foster further studies on the role of CB dysfunction in the pathogenesis of highly prevalent human diseases.

  14. Carotid Artery Intima-Media Thickness, Carotid Plaque and Coronary Heart Disease and Stroke in Chinese

    PubMed Central

    Chien, Kuo-Liong; Su, Ta-Chen; Jeng, Jiann-Shing; Hsu, Hsiu-Ching; Chang, Wei-Tien; Chen, Ming-Fong; Lee, Yuan-Teh; Hu, Frank B.

    2008-01-01

    Background Our aim was to prospectively investigate the association between carotid artery intima-media thickness (IMT) as well as carotid plaque and incidence of coronary heart disease (CHD) and stroke in Chinese, among whom data are limited. Methods and Findings We conducted a community-based cohort study composed of 2190 participants free of cardiovascular disease at baseline in one community. During a median 10.5-year follow up, we documented 68 new cases of coronary heart disease and 94 cases of stroke. The multivariate relative risks (RRs) associated with a change of 1 standard deviation of maximal common carotid IMT were 1.38 (95% confidence interval [CI], 1.12–1.70) for CHD and 1.47 (95% CI, 1.28–1.69) for stroke. The corresponding RRs with internal carotid IMT were 1.47 (95% CI, 1.21–1.79) for CHD and 1.52 (95% CI, 1.31–1.76) for stroke. Carotid plaque measured by the degree of diameter stenosis was also significantly associated with increased risk of CHD (p for trend<0.0001) and stroke (p for trend<0.0001). However, these associations were largely attenuated when adjusting for IMT measurements. Conclusions This prospective study indicates a significant association between carotid IMT and incidence of CHD and stroke in Chinese adults. These measurements may be useful for cardiovascular risk assessment and stratification in Chinese. PMID:18927612

  15. Common Carotid Artery Stump Syndrome Due to Mobile Thrombus Detected by Carotid Duplex Ultrasonography.

    PubMed

    Omoto, Shusaku; Hasegawa, Yuki; Sakai, Kenichiro; Matsuno, Hiromasa; Arai, Ayumi; Terasawa, Yuka; Mitsumura, Hidetaka; Iguchi, Yasuyuki

    2016-10-01

    Carotid stump syndrome is a cause of recurrent embolic stroke following occlusion of the ipsilateral internal carotid artery. The present report describes a case of recurrent cerebral embolism ipsilateral to a chronically occluded left common carotid artery (CCA), i.e., "CCA stump syndrome." Doppler color flow imaging showed anterograde flow in the left internal and external carotid arteries, which were supplied by collateral flow from the superior thyroid artery inflowing just proximal to the left carotid bifurcation. According to carotid duplex ultrasonography (CDU), a low-echoic mobile thrombus was noted at the distal stump of the occluded CCA, which presumably caused distal embolism. The low-echoic mobile thrombus dramatically changed to a homogenously high-echoic thrombus, and there was no recurrence of stroke after antiplatelet and anticoagulant therapy. This is the first report to demonstrate a CDU-verified temporal change in the thrombus at the stump in CCA stump syndrome. CDU is a noninvasive and useful technique to characterize hemodynamics, thrombus morphology, and the response to therapy. PMID:27567297

  16. Association of Circulating Matrix Metalloproteinases with Carotid Artery Characteristics: The ARIC Carotid MRI Study

    PubMed Central

    Gaubatz, John W.; Ballantyne, Christie M.; Wasserman, Bruce A.; He, Max; Chambless, Lloyd E.; Boerwinkle, Eric; Hoogeveen, Ron C.

    2010-01-01

    Objective To examine the relationship of plasma levels of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase-1 (TIMP-1) with carotid artery characteristics measured by magnetic resonance imaging (MRI) in a cross-sectional investigation among Atherosclerosis Risk in Communities (ARIC) Carotid MRI Study participants. Methods and Results A stratified random sample was recruited based on intima-media thickness (IMT) from a previous ultrasound examination. A high-resolution gadolinium-enhanced MRI exam of the carotid artery was performed in 2004–2005 on 1,901 ARIC cohort participants. Multiple carotid wall characteristics including wall thickness, lumen area, calcium area, lipid core and fibrous cap measures were evaluated for associations with plasma MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9 and TIMP-1. Plasma MMP-1, MMP-3, and MMP-7 were significantly higher among participants in the high IMT group compared to those in the low IMT group. Normalized wall index was independently associated with MMP-3, MMP-7, and TIMP-1. MMP-7 was positively associated with carotid calcification. Mean fibrous cap thickness was significantly higher in individuals with elevated TIMP-1 levels. In addition, TIMP-1 was positively associated with measures of lipid core. Conclusions Circulating levels of specific MMPs and TIMP-1 were associated with carotid wall remodeling and structural changes related to plaque burden in the elderly. PMID:20167662

  17. Carotid Doppler evaluation in cerebrovascular disease.

    PubMed Central

    D'Alton, J. G.; Norris, J. W.

    1983-01-01

    The Doppler technique has proven to be a useful noninvasive technique for evaluating the patency of the carotid artery in patients at risk of stroke. The data obtained from 246 carotid Doppler examinations were compared with the angiographic findings in the same patients. The sensitivity, specificity and accuracy were high when the degree of stenosis was greater than 50%, but occlusions were less reliably detected, with 8 (33%) of the 24 being misdiagnosed as high-grade stenoses. Carotid Doppler evaluation guides and accelerates decisions regarding further investigations, such as cerebral angiography. It helps one decide whether a neck bruit is of arterial origin and aids assessment following cerebrovascular surgery. It is not a substitute for cerebral angiography because it poorly visualizes both the posterior and the intracranial circulations and cannot accurately detect low-grade (less than 50%) stenoses or ulcerated arterial plaques. Detection of stenosis in a carotid artery in an otherwise uncertain case is an indication for cerebral angiography, so the Doppler technique will probably increase the number of angiograms performed. However, this technique is also useful in follow-up, being without hazard, and should, therefore, reduce the likelihood of unnecessary angiographic examinations. Images FIG. 2 FIG. 3A FIG. 3B FIG. 5 PMID:6640454

  18. Carotid baroreflex response following 30 days exposure to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Doerr, D. F.; Eckberg, D. L.; Fritsch, J. M.; Vernikos-Danellis, J.

    1989-01-01

    The mechanism of the carotid-baroreflex response to weightlessness was investigated in human subjects exposed to simulated microgravity (30 days of 6-day head-down bed rest followed by 5 days of recovery). Baroreceptor-cardiac reflex responses were elicited by a complex sequence of pressure changes delivered to a neck chamber device. The shape of the sigmoid baroreceptor-cardiac response curve was examined for alterations and the occurrence of resetting, as well as for a possible association of the impaired baroreflex function with hypotension during the postexposure orthostatic stress. It was found that the exposure to head-down bed rest caused a significant shift on the R-R interval axis, which paralleled reductions and elevations in baseline HR such that the baseline R-R (operational point) remained in the same position on the response curve. This shift in the location of the reflex relation indicates a significant resetting of the carotid baroreceptors, which may represent an appropriate adaptation which contributes to the maintenance of a constant resting arterial blood pressure before, during, and after bed rest, observed in these study.

  19. Combination of Light and Melatonin Time Cues for Phase Advancing the Human Circadian Clock

    PubMed Central

    Burke, Tina M.; Markwald, Rachel R.; Chinoy, Evan D.; Snider, Jesse A.; Bessman, Sara C.; Jung, Christopher M.; Wright, Kenneth P.

    2013-01-01

    Study Objectives: Photic and non-photic stimuli have been shown to shift the phase of the human circadian clock. We examined how photic and non-photic time cues may be combined by the human circadian system by assessing the phase advancing effects of one evening dose of exogenous melatonin, alone and in combination with one session of morning bright light exposure. Design: Randomized placebo-controlled double-blind circadian protocol. The effects of four conditions, dim light (∼1.9 lux, ∼0.6 Watts/m2)-placebo, dim light-melatonin (5 mg), bright light (∼3000 lux, ∼7 Watts/m2)-placebo, and bright light-melatonin on circadian phase was assessed by the change in the salivary dim light melatonin onset (DLMO) prior to and following treatment under constant routine conditions. Melatonin or placebo was administered 5.75 h prior to habitual bedtime and 3 h of bright light exposure started 1 h prior to habitual wake time. Setting: Sleep and chronobiology laboratory environment free of time cues. Participants: Thirty-six healthy participants (18 females) aged 22 ± 4 y (mean ± SD). Results: Morning bright light combined with early evening exogenous melatonin induced a greater phase advance of the DLMO than either treatment alone. Bright light alone and melatonin alone induced similar phase advances. Conclusion: Information from light and melatonin appear to be combined by the human circadian clock. The ability to combine circadian time cues has important implications for understanding fundamental physiological principles of the human circadian timing system. Knowledge of such principles is important for designing effective countermeasures for phase-shifting the human circadian clock to adapt to jet lag, shift work, and for designing effective treatments for circadian sleep-wakefulness disorders. Citation: Burke TM; Markwald RR; Chinoy ED; Snider JA; Bessman SC; Jung CM; Wright Jr KP. Combination of light and melatonin time cues for phase advancing the human circadian

  20. Automated carotid artery intima layer regional segmentation

    NASA Astrophysics Data System (ADS)

    Meiburger, Kristen M.; Molinari, Filippo; Rajendra Acharya, U.; Saba, Luca; Rodrigues, Paulo; Liboni, William; Nicolaides, Andrew; Suri, Jasjit S.

    2011-07-01

    Evaluation of the carotid artery wall is essential for the assessment of a patient's cardiovascular risk or for the diagnosis of cardiovascular pathologies. This paper presents a new, completely user-independent algorithm called carotid artery intima layer regional segmentation (CAILRS, a class of AtheroEdge™ systems), which automatically segments the intima layer of the far wall of the carotid ultrasound artery based on mean shift classification applied to the far wall. Further, the system extracts the lumen-intima and media-adventitia borders in the far wall of the carotid artery. Our new system is characterized and validated by comparing CAILRS borders with the manual tracings carried out by experts. The new technique is also benchmarked with a semi-automatic technique based on a first-order absolute moment edge operator (FOAM) and compared to our previous edge-based automated methods such as CALEX (Molinari et al 2010 J. Ultrasound Med. 29 399-418, 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CULEX (Delsanto et al 2007 IEEE Trans. Instrum. Meas. 56 1265-74, Molinari et al 2010 IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57 1112-24), CALSFOAM (Molinari et al Int. Angiol. (at press)), and CAUDLES-EF (Molinari et al J. Digit. Imaging (at press)). Our multi-institutional database consisted of 300 longitudinal B-mode carotid images. In comparison to semi-automated FOAM, CAILRS showed the IMT bias of -0.035 ± 0.186 mm while FOAM showed -0.016 ± 0.258 mm. Our IMT was slightly underestimated with respect to the ground truth IMT, but showed uniform behavior over the entire database. CAILRS outperformed all the four previous automated methods. The system's figure of merit was 95.6%, which was lower than that of the semi-automated method (98%), but higher than that of the other automated techniques.

  1. Advances in probing the blood vessels of the human brain using magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Haacke, E. Mark

    2002-03-01

    Magnetic resonance imaging offers a marvelous means to probe the vasculature of the human body non-invasively. The first major advances came when the physics of the effects of motion in MRI were first understood well enough that new methods could be designed to compensate for the motion. This led to the development of MR angiography. The second major advance occurred when a contrast agent was used to enhance the signal from vessels independent of blood flow. This made it possible to image much smaller vessels because of the increased signal-to-noise ratio. The third major advance occurred when the susceptibility of the venous blood was used to create a new contrast unique to veins even in the presence of the contrast agent to enhance their signal. The fourth advance is close behind with the potential to use the susceptibility to measure the local oxygen content. Each of these advances involved some interesting physics and raised questions about local magnetic field effects, some of which remain unanswered yet today. We will show results from the first three levels with hints at how to proceed to the fourth. The development of this technology has important clinical implications. With new higher relaxivity contrast agents and higher field magnets coming on the market, the possibility to image vessels down to on the order of 100 microns may be viable. Each advance has enhanced the range of applications from just imaging vessels to occult vascular disease, trauma, the detection of blood products, and physiologic function of the tissue itself.

  2. Advanced Imaging and Tissue Engineering of the Human Limbal Epithelial Stem Cell Niche

    PubMed Central

    Massie, Isobel; Dziasko, Marc; Kureshi, Alvena; Levis, Hannah J.; Morgan, Louise; Neale, Michael; Sheth, Radhika; Tovell, Victoria E.; Vernon, Amanda J.; Funderburgh, James L.; Daniels, Julie T.

    2015-01-01

    The limbal epithelial stem cell niche provides a unique, physically protective environment in which limbal epithelial stem cells reside in close proximity with accessory cell types and their secreted factors. The use of advanced imaging techniques is described to visualize the niche in three dimensions in native human corneal tissue. In addition, a protocol is provided for the isolation and culture of three different cell types, including human limbal epithelial stem cells from the limbal niche of human donor tissue. Finally, the process of incorporating these cells within plastic compressed collagen constructs to form a tissue-engineered corneal limbus is described and how immunohistochemical techniques may be applied to characterize cell phenotype therein. PMID:25388395

  3. Challenges and advances in mouse modeling for human pancreatic tumorigenesis and metastasis

    PubMed Central

    Qiu, Wanglong

    2013-01-01

    Pancreatic cancer is critical for developed countries, where its rate of diagnosis has been increasing steadily annually. In the past decade, the advances of pancreatic cancer research have not contributed to the decline in mortality rates from pancreatic cancer—the overall 5-year survival rate remains about 5% low. This number only underscores an obvious urgency for us to better understand the biological features of pancreatic carcinogenesis, to develop early detection methods, and to improve novel therapeutic treatments. To achieve these goals, animal modeling that faithfully recapitulates the whole process of human pancreatic cancer is central to making the advancements. In this review, we summarize the currently available animal models for pancreatic cancer and the advances in pancreatic cancer animal modeling. We compare and contrast the advantages and disadvantages of three major categories of these models: (1) carcinogen-induced; (2) xenograft and allograft; and (3) genetically engineered mouse models. We focus more on the genetically engineered mouse models, a category which has been rapidly expanded recently for their capacities to mimic human pancreatic cancer and metastasis, and highlight the combinations of these models with various newly developed strategies and cell-lineage labeling systems. PMID:23114842

  4. A framework for advanced methods of control of human-induced vibrations

    NASA Astrophysics Data System (ADS)

    Reynolds, Paul

    2012-04-01

    The vibration serviceability of civil engineering structures under human dynamic excitation is becoming ever more critical with the design and redevelopment of structures with reduced mass, stiffness and damping. A large number of problems have been reported in floors, footbridges, sports stadia, staircases and other structures. Unfortunately, the range of options available to fix such problems are very limited and are primarily limited to structural modification or the implementation of passive vibration control measures, such as tuned mass dampers. This paper presents the initial development of a new framework for advanced methods of control of humaninduced vibrations in civil engineering structures. This framework includes both existing passive methods of vibration control and more advanced active, semi-active and hybrid control techniques, which may be further developed as practical solutions for these problems. Through the use of this framework, rational decisions as to the most appropriate technologies for particular human vibration problems may be made and pursued further. This framework is also intended to be used in the design of new civil engineering structures, where advanced control technologies may be used both to increase the achievable slenderness and to reduce the amount of construction materials used and hence their embodied energy. This will be an ever more important consideration with the current drive for structures with reduced environmental impact.

  5. The discovery of sensory nature of the carotid bodies--invited article.

    PubMed

    De Castro, F

    2009-01-01

    Although the carotid body (or glomus caroticum) was a structure familiar to anatomists in the XVIIIth century, it was not until the beginning of the XXth century that its role was revealed. It was then that the German physiologist Heinrich Hering described the respiratory reflex and he began to study the anatomical basis of this reflex focusing on the carotid region, and the carotid sinus in particular. At this time, the physiologists and pharmacologists associated with Jean-François Heymans and his son (Corneille) in Ghent (Belgium) adopted a different approach to resolve this issue, and they centred their efforts on the cardio-aortic reflexogenic region. However, at the Laboratorio de Investigaciones Biológicas (Madrid, Spain), one of the youngest and more brilliant disciples of Santiago Ramón y Cajal, Fernando De Castro, took advantage of certain technical advances to study the fine structure of the carotid body (De Castro, 1925). In successive papers (1926, 1928, 1929), De Castro unravelled most of the histological secrets of this small structure and described the exact localisation of the "chemoreceptors" within the glomus. Indeed, his was the first description of cells specifically devoted to detect changes in the chemical composition of blood. Heymans was deeply interested in the work of De Castro, and he extended two invitations to the Spanish neurologist to visit (1929 and 1932) so that they could share their experiences. From 1932-1933, Corneille Heymans focused his attention on the carotid body and his physiological demonstration of De Castro's hypothesis regarding chemoreceptors led to him obtaining the Nobel Prize in Physiology or Medicine in 1938, while Spain was immersed in its catastrophic Civil War.

  6. Anatomical Considerations on Surgical Anatomy of the Carotid Bifurcation

    PubMed Central

    Michalinos, Adamantios; Chatzimarkos, Markos; Arkadopoulos, Nikolaos; Safioleas, Michail

    2016-01-01

    Surgical anatomy of carotid bifurcation is of unique importance for numerous medical specialties. Despite extensive research, many aspects such as precise height of carotid bifurcation, micrometric values of carotid arteries and their branches as their diameter, length, and degree of tortuosity, and variations of proximal external carotid artery branches are undetermined. Furthermore carotid bifurcation is involved in many pathologic processes, atheromatous disease being the commonest. Carotid atheromatous disease is a major predisposing factor for disabling and possibly fatal strokes with geometry of carotid bifurcation playing an important role in its natural history. Consequently detailed knowledge of various anatomic parameters is of paramount importance not only for understanding of the disease but also for design of surgical treatment, especially selection between carotid endarterectomy and carotid stenting. Carotid bifurcation paragangliomas constitute unique tumors with diagnostic accuracy, treatment design, and success of operative intervention dependent on precise knowledge of anatomy. Considering those, it becomes clear that selection and application of proper surgical therapy should consider anatomical details. Further research might ameliorate available treatment options or even lead to innovative ones. PMID:27047690

  7. Recent advances in the prenatal interrogation of the human fetal genome.

    PubMed

    Hui, Lisa; Bianchi, Diana W

    2013-02-01

    The amount of genetic and genomic information obtainable from the human fetus during pregnancy is accelerating at an unprecedented rate. Two themes have dominated recent technological advances in prenatal diagnosis: interrogation of the fetal genome in increasingly high resolution and the development of non-invasive methods of fetal testing using cell-free DNA in maternal plasma. These two areas of advancement have now converged with several recent reports of non-invasive assessment of the entire fetal genome from maternal blood. However, technological progress is outpacing the ability of the healthcare providers and patients to incorporate these new tests into existing clinical care, and further complicates many of the economic and ethical dilemmas in prenatal diagnosis. This review summarizes recent work in this field and discusses the integration of these new technologies into the clinic and society.

  8. Serum Osteoprotegerin Is Associated With Calcified Carotid Plaque: A Strobe-Compliant Observational Study.

    PubMed

    Kwon, Ami; Choi, Yun-Seok; Choi, Yong-Won; Chung, Woo-Baek; Park, Chul-Soo; Chung, Wook-Sung; Lee, Man-Young; Youn, Ho-Joong

    2016-04-01

    Osteoprotegerin (OPG) is a kind of tumor necrosis factor, which is related to bone metabolism and vascular calcification. The increase of Osteoprotegerin concentration in serum is related to cardiovascular diseases in humans. The purpose of this study was to figure out the relevance between osteoprotegerin in serum and carotid calcification. Serum OPG concentrations were compared in 145 patients who underwent carotid sonography (average age: 68 ± 9 years old, male: female = 81:64). A calcified plaque (CP) (37 people [27%]), a noncalcified plaque (NCP) (54 people [37%]), and a nonplaque (NP) (54 people [37%]) were classified for this study. No significant differences among 3 groups were demonstrated in the distribution of age, diabetes, high blood pressure, and hyperlipidemia. Serum osteoprotegerin concentrations were significantly increased in CP group rather than NCP group or NP group; (median [interquartile range], 4016 [1410] vs 3210 [1802] pg/mL, P < 0.05 and 4016 [1410] vs 3204 [1754] pg/mL, P < 0.05). Serum osteoprotegerin concentrations did not indicate a significant difference between NCP Group or NP Group. This study had proved that patient group accompanied with carotid calcification in carotid artery disease had an increased serum OPG concentration, so it could consider that OPG plays an important function on calcification related to arteriosclerosis. PMID:27082605

  9. Measuring therapeutic alliance between oncologists and patients with advanced cancer: The Human Connection Scale

    PubMed Central

    Mack, Jennifer W; Block, Susan D.; Nilsson, Matthew; Wright, Alexi; Trice, Elizabeth; Friedlander, Robert; Paulk, Elizabeth; Prigerson, Holly G

    2009-01-01

    Objectives Patients consider having a human connection with a physician to be an important aspect of end-of-life (EOL) care. We sought to develop and validate a measure of therapeutic alliance between advanced cancer patients and their physicians, and to evaluate the effects of therapeutic alliance on EOL experiences and care. Methods We developed The Human Connection (THC) scale to measure the extent to which patients felt a sense of mutual understanding, caring, and trust with their physicians. The scale was administered to 217 advanced cancer patients along with measures of attributes hypothesized to be related to therapeutic alliance, including emotional acceptance of terminal illness. EOL outcomes in 90 patients who died during the study were also examined. Results The 16-item THC questionnaire was internally consistent (Cronbach’s α =.90) and valid, based on its expected positive association with emotional acceptance of the terminal illness (r=.31, P<.0001). THC scores were inversely related to symptom burden (r=−.19, P=.006), functional status (Karnofsky score, r=.22, P=.001), and mental illness (THC score 50.69 for patients with any DSM diagnosis versus 55.22 for those without, P=.03). THC scores were not significantly associated with EOL discussions (P=.68). Among patients who had died, EOL ICU care was inversely associated with therapeutic alliance (THC score 46.5 for those with ICU care versus 55.5 for those without, P=.002), such that patients with higher THC scores were less likely to spend time in the ICU during the last week of life. Conclusion The THC scale is a valid and reliable measure of therapeutic alliance between advanced cancer patients and their physicians. In addition, we found no evidence to suggest that EOL discussions harm patients’ therapeutic alliance. A strong therapeutic alliance is associated with emotional acceptance of a terminal illness and with decreased ICU care at the end of life among patients with advanced cancer

  10. Association between human papillomavirus and EGFR mutations in advanced lung adenocarcinoma

    PubMed Central

    Li, Ming; Deng, Fang; Qian, Li-Ting; Meng, Shui-Ping; Zhang, Yang; Shan, Wu-Lin; Zhang, Xiao-Lei; Wang, Bao-Long

    2016-01-01

    Previous studies have demonstrated an association between human papillomavirus (HPV) and mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer patients; however, few studies have investigated this association in advanced lung adenocarcinoma patients undergoing gefitinib treatment. The present study investigated the association between HPV and EGFR mutations in advanced lung adenocarcinoma patients. A total of 95 advanced lung adenocarcinoma patients were enrolled in the study. The HPV infection status and presence of EGFR mutations in tumor tissue was evaluated. Patient clinical characteristics were also determined and compared with HPV infection and EGFR mutation status to analyze their impact on progression-free survival. HPV DNA was identified in 27/95 (28.4%) lung adenocarcinoma tumors and was most common in patients with lymph node metastasis (P=0.016). A total of 44/95 (46.3%) cases exhibited EGFR mutations, which were predominantly observed in female patients and non-smokers. The presence of HPV DNA was significantly associated with EGFR mutations (P=0.012) and multivariate analysis also revealed that HPV DNA was significantly associated with EGFR mutations (odds ratio=3.971) in advanced lung adenocarcinoma. Patients with both HPV infections and EGFR mutations exhibit a marked decrease in the risk of lung cancer progression when compared with those without HPV infection or EGFR mutations (adjusted HR=0.640; 95% confidence interval: 0.488–0.840; P=0.001). HPV infection was significantly associated with EGFR mutations in advanced lung adenocarcinoma patients. Furthermore, patients with HPV infections exhibited the longest progression-free survival times, which may be due to good response to tyrosine kinase inhibitor- or platinum-based-adjuvant therapy in these patients. Patients with EGFR mutations exhibited a better prognosis when compared with those exhibiting wild-type EGFR, regardless of HPV status. PMID:27602120

  11. Association between human papillomavirus and EGFR mutations in advanced lung adenocarcinoma

    PubMed Central

    Li, Ming; Deng, Fang; Qian, Li-Ting; Meng, Shui-Ping; Zhang, Yang; Shan, Wu-Lin; Zhang, Xiao-Lei; Wang, Bao-Long

    2016-01-01

    Previous studies have demonstrated an association between human papillomavirus (HPV) and mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer patients; however, few studies have investigated this association in advanced lung adenocarcinoma patients undergoing gefitinib treatment. The present study investigated the association between HPV and EGFR mutations in advanced lung adenocarcinoma patients. A total of 95 advanced lung adenocarcinoma patients were enrolled in the study. The HPV infection status and presence of EGFR mutations in tumor tissue was evaluated. Patient clinical characteristics were also determined and compared with HPV infection and EGFR mutation status to analyze their impact on progression-free survival. HPV DNA was identified in 27/95 (28.4%) lung adenocarcinoma tumors and was most common in patients with lymph node metastasis (P=0.016). A total of 44/95 (46.3%) cases exhibited EGFR mutations, which were predominantly observed in female patients and non-smokers. The presence of HPV DNA was significantly associated with EGFR mutations (P=0.012) and multivariate analysis also revealed that HPV DNA was significantly associated with EGFR mutations (odds ratio=3.971) in advanced lung adenocarcinoma. Patients with both HPV infections and EGFR mutations exhibit a marked decrease in the risk of lung cancer progression when compared with those without HPV infection or EGFR mutations (adjusted HR=0.640; 95% confidence interval: 0.488–0.840; P=0.001). HPV infection was significantly associated with EGFR mutations in advanced lung adenocarcinoma patients. Furthermore, patients with HPV infections exhibited the longest progression-free survival times, which may be due to good response to tyrosine kinase inhibitor- or platinum-based-adjuvant therapy in these patients. Patients with EGFR mutations exhibited a better prognosis when compared with those exhibiting wild-type EGFR, regardless of HPV status.

  12. DEVELOPMENT OF HUMAN FACTORS ENGINEERING GUIDANCE FOR SAFETY EVALUATIONS OF ADVANCED REACTORS.

    SciTech Connect

    O'HARA, J.; PERSENSKY, J.; SZABO, A.

    2006-10-01

    Advanced reactors are expected to be based on a concept of operations that is different from what is currently used in today's reactors. Therefore, regulatory staff may need new tools, developed from the best available technical bases, to support licensing evaluations. The areas in which new review guidance may be needed and the efforts underway to address the needs will be discussed. Our preliminary results focus on some of the technical issues to be addressed in three areas for which new guidance may be developed: automation and control, operations under degraded conditions, and new human factors engineering methods and tools.

  13. Estimation of Stiffness Parameter on the Common Carotid Artery

    NASA Astrophysics Data System (ADS)

    Koya, Yoshiharu; Mizoshiri, Isao; Matsui, Kiyoaki; Nakamura, Takashi

    The arteriosclerosis is on the increase with an aging or change of our living environment. For that reason, diagnosis of the common carotid artery using echocardiogram is doing to take precautions carebropathy. Up to the present, several methods to measure stiffness parameter of the carotid artery have been proposed. However, they have analyzed at the only one point of common carotid artery. In this paper, we propose the method of analysis extended over a wide area of common carotid artery. In order to measure stiffness parameter of common carotid artery from echocardiogram, it is required to detect two border curves which are boundaries between vessel wall and blood. The method is composed of two steps. The first step is the detection of border curves, and the second step is the calculation of stiffness parameter using diameter of common carotid artery. Experimental results show the validity of the proposed method.

  14. The Development of Carotid Stent Material

    PubMed Central

    He, Dongsheng; Liu, Wenhua; Zhang, Tao

    2015-01-01

    Endovascular angioplasty with stenting is a promising option for treating carotid artery stenosis. There exist a rapidly increasing number of different stent types with different materials. The bare-metal stent is the most commonly used stent with acceptable results, but it leaves us with the problems of thrombosis and restenosis. The drug-eluting stent is a breakthrough as it has the ability to reduce the restenosis rate, but the problem of late thrombosis still has to be addressed. The biodegradable stent disappears after having served its function. However, restenosis and degradation rates remain to be studied. In this article, we review every stent material with its characteristics, clinical results and complications and point out the standards of an ideal carotid stent. PMID:26019710

  15. HW 03-4 CAROTID BAROREFLEX ACTIVATION THERAPY.

    PubMed

    Alnima, Teba

    2016-09-01

    Electrical carotid baroreflex activation therapy is an emerging device-based treatment for patients with treatment-resistant hypertension. Its blood pressure lowering effect has been demonstrated in several animal and human studies. In addition, this treatment has showed its prolonged effect over the long-term. The main mechanism of the blood pressure reduction during this therapy is by inhibition of the sympathetic outflow. Yet the question arises whether the inhibition of central sympathetic activity is sufficient to be the sole mechanism behind the sustained reduction in blood pressure. In this lecture, we will present the latest data on the effect of baroreflex activation therapy on blood pressure, the mechanisms of action that account for the persistent blood pressure lowering, the most suitable candidates for this treatment and future developments on the field of baropacing. PMID:27643277

  16. Endovascular Treatment of Extracranial Internal Carotid Aneurysms Using Endografts

    SciTech Connect

    Baldi, Sebastian Rostagno, Roman D.; Zander, Tobias; Llorens, Rafael; Schonholz, Claudio; Maynar, Manuel

    2008-03-15

    Aneurysms of the extracranial internal carotid artery (EICA) are infrequent. They are difficult to treat with conventional surgery because of their distal extension into the skull base. We report three cases of EICA aneurysms in two symptomatic patients successfully treated with polytetrafluoroethylene self-expanding endografts using an endovascular approach. The aneurysms were located distal to the carotid bifurcation and extended to the subpetrous portion of the internal carotid artery.

  17. Comparative Review of the Treatment Methodologies of Carotid Stenosis

    PubMed Central

    Bae, Coney; Szuchmacher, Mauricio; Chang, John B.

    2015-01-01

    The treatment of carotid stenosis entails three methodologies, namely, medical management, carotid angioplasty and stenting (CAS), as well as carotid endarterectomy (CEA). The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial (ECST) have shown that symptomatic carotid stenosis greater than 70% is best treated with CEA. In asymptomatic patients with carotid stenosis greater than 60%, CEA was more beneficial than treatment with aspirin alone according to the Asymptomatic Carotid Atherosclerosis (ACAS) and Asymptomatic Carotid Stenosis Trial (ACST) trials. When CAS is compared with CEA, the CREST resulted in similar rates of ipsilateral stroke and death rates regardless of symptoms. However, CAS not only increased adverse effects in women, it also amplified stroke rates and death in elderly patients compared with CEA. CAS can maximize its utility in treating focal restenosis after CEA and patients with overwhelming cardiac risk or prior neck irradiation. When performing CEA, using a patch was equated to a more durable result than primary closure, whereas eversion technique is a new methodology deserving a spotlight. Comparing the three major treatment strategies of carotid stenosis has intrinsic drawbacks, as most trials are outdated and they vary in their premises, definitions, and study designs. With the newly codified best medical management including antiplatelet therapies with aspirin and clopidogrel, statin, antihypertensive agents, strict diabetes control, smoking cessation, and life style change, the current trials may demonstrate that asymptomatic carotid stenosis is best treated with best medical therapy. The ongoing trials will illuminate and reshape the treatment paradigm for symptomatic and asymptomatic carotid stenosis. PMID:26417191

  18. Carotid artery access for transcatheter aortic valve replacement.

    PubMed

    Guyton, Robert A; Block, Peter C; Thourani, Vinod H; Lerakis, Stamatios; Babaliaros, Vasilis

    2013-10-01

    We report three patients who had successful transcatheter aortic valve replacement (TAVR) via carotid artery access. None were candidates for thoracotomy (including minimal access incisions) and had no other vascular access sites that would accommodate the transcatheter valve sheath. Antegrade carotid perfusion and retrograde insertion of the delivery sheath maintained cerebral blood flow without sequelae. Carotid access for TAVR is an option for unusual patients without other access.

  19. Advances in Pemphigus and its Endemic Pemphigus Foliaceus (Fogo Selvagem) Phenotype: A Paradigm of Human Autoimmunity

    PubMed Central

    Culton, Donna A.; Qian, Ye; Li, Ning; Rubenstein, David; Aoki, Valeria; Filhio, Gunter Hans; Rivitti, Evandro A.; Diaz, Luis A.

    2009-01-01

    Pemphigus encompasses a group of organ specific, antibody mediated autoimmune diseases of the skin characterized by keratinocyte detachment that leads to the development of blisters and erosions, which can become life-threatening. The pathogenic autoantibodies recognize desmogleins, which are members of the desmosomal cadherin family of cell adhesion molecules. Desmoglein 3 is targeted in pemphigus vulgaris while desmoglein 1 is targeted in pemphigus foliaceus and its endemic form, fogo selvagem. This review will briefly define the salient features of pemphigus and the proposed steps in pathogenesis. We will then summarize the most recent advances in three important areas of investigation: (i) epidemiologic, genetic, and immunologic features of fogo selvagem, (ii) molecular mechanisms of injury to the epidermis, and (iii) novel therapeutic strategies targeting specific steps in disease pathogenesis. The advances in each of these three seemingly separate areas contribute to the overall understanding of the pemphigus disease model. These recent advancements also underscore the dynamic interplay between the treatment of patients in a clinical setting and basic science research, which has led to an integrative understanding disease pathogenesis and treatment and allow pemphigus to serve as a paradigm of human autoimmunity. PMID:18838249

  20. Technology Roadmap Instrumentation, Control, and Human-Machine Interface to Support DOE Advanced Nuclear Energy Programs

    SciTech Connect

    Donald D Dudenhoeffer; Burce P Hallbert

    2007-03-01

    Instrumentation, Controls, and Human-Machine Interface (ICHMI) technologies are essential to ensuring delivery and effective operation of optimized advanced Generation IV (Gen IV) nuclear energy systems. In 1996, the Watts Bar I nuclear power plant in Tennessee was the last U.S. nuclear power plant to go on line. It was, in fact, built based on pre-1990 technology. Since this last U.S. nuclear power plant was designed, there have been major advances in the field of ICHMI systems. Computer technology employed in other industries has advanced dramatically, and computing systems are now replaced every few years as they become functionally obsolete. Functional obsolescence occurs when newer, more functional technology replaces or supersedes an existing technology, even though an existing technology may well be in working order.Although ICHMI architectures are comprised of much of the same technology, they have not been updated nearly as often in the nuclear power industry. For example, some newer Personal Digital Assistants (PDAs) or handheld computers may, in fact, have more functionality than the 1996 computer control system at the Watts Bar I plant. This illustrates the need to transition and upgrade current nuclear power plant ICHMI technologies.

  1. Are Carotid Stent Fractures Clinically Significant?

    SciTech Connect

    Garcia-Toca, Manuel; Rodriguez, Heron E.; Naughton, Peter A.; Keeling, Aiofee; Phade, Sachin V.; Morasch, Mark D.; Kibbe, Melina R.; Eskandari, Mark K.

    2012-04-15

    Purpose: Late stent fatigue is a known complication after carotid artery stenting (CAS) for cervical carotid occlusive disease. The purpose of this study was to determine the prevalence and clinical significance of carotid stent fractures. Materials and Methods: A single-center retrospective review of 253 carotid bifurcation lesions treated with CAS and mechanical embolic protection from April 2001 to December 2009 was performed. Stent integrity was analyzed by two independent observers using multiplanar cervical plain radiographs with fractures classified into the following types: type I = single strut fracture; type II = multiple strut fractures; type III = transverse fracture; and type IV = transverse fracture with dislocation. Mean follow-up was 32 months. Results: Follow-up imaging was completed on 106 self-expanding nitinol stents (26 closed-cell and 80 open-cell stents). Eight fractures (7.5%) were detected (type I n = 1, type II n = 6, and type III n = 1). Seven fractures were found in open-cell stents (Precise n = 3, ViVEXX n = 2, and Acculink n = 2), and 1 fracture was found in a closed-cell stent (Xact n = 1) (p = 0.67). Only a previous history of external beam neck irradiation was associated with fractures (p = 0.048). No associated clinical sequelae were observed among the patients with fractures, and only 1 patient had an associated significant restenosis ({>=}80%) requiring reintervention. Conclusions: Late stent fatigue after CAS is an uncommon event and rarely clinically relevant. Although cell design does not appear to influence the occurrence of fractures, lesion characteristics may be associated risk factors.

  2. Aterofisiol® in carotid plaque evolution

    PubMed Central

    Amato, Bruno; Compagna, Rita; Amato, Maurizio; Gallelli, Luca; de Franciscis, Stefano; Serra, Raffaele

    2015-01-01

    Background In patients with carotid stenosis, the risk of plaque rupture is related to the composition of the atherosclerotic plaque rather than to its magnitude. In this regard, we evaluated the effects of a supplement, Aterofisiol,® containing omega-3 (EPA [eicosapen acid] DHA [docosahexaenoic acid]), vitamin K2, vitamin B6, vitamin B12, oligomeric proanthocyanidins (OPC) and resveratrol on the composition of atherosclerotic plaque and on neurological symptoms in patients with carotid stenosis undergoing carotid endarterectomy. Methods The study was randomized, prospective, and double-blinded. Eligible patients were of both sexes, with carotid stenosis >70% who underwent endarterectomy. Enrolled patients were randomly allocated to receive either one tablet of acetylsalicylic acid 100 mg (Cardioaspirin®) + one tablet of Aterofisiol every 24 hours or one tablet of Cardioaspirin + one tablet of placebo every 24 hours. Each treatment was started 30 days before the surgery and was stopped 5 days before the surgery. The plaques were removed “en bloc” using standard surgical technique. Results During the study period, 214 patients (135 men and 79 women) were enrolled for intent-to-treat and randomized in two groups: Group A: 107 patients (68 men and 39 women) were treated with Cardioaspirin + Aterofisiol. Group B: 107 patients (67 men and 40 women) were treated with Cardioaspirin + placebo. At the end of the study, 202 patients participated fully (103 patients in Group A and 99 patients in Group B), making up the protocol evaluation population (94.4%). The mean lipid content of removed plaques was significantly lower (P<0.05) in Group A. We recorded a significantly lower incidence of neurological symptoms in Group A in comparison with Group B (P<0.05). Conclusion In the study, Aterofisiol showed to be effective in reducing the amounts of cholesterol and lipids in the plaques and in reducing adverse neurological events in the study group with respect to controls

  3. Markerless attenuation correction for carotid MRI surface receiver coils in combined PET/MR imaging

    NASA Astrophysics Data System (ADS)

    Eldib, Mootaz; Bini, Jason; Robson, Philip M.; Calcagno, Claudia; Faul, David D.; Tsoumpas, Charalampos; Fayad, Zahi A.

    2015-06-01

    The purpose of the study was to evaluate the effect of attenuation of MR coils on quantitative carotid PET/MR exams. Additionally, an automated attenuation correction method for flexible carotid MR coils was developed and evaluated. The attenuation of the carotid coil was measured by imaging a uniform water phantom injected with 37 MBq of 18F-FDG in a combined PET/MR scanner for 24 min with and without the coil. In the same session, an ultra-short echo time (UTE) image of the coil on top of the phantom was acquired. Using a combination of rigid and non-rigid registration, a CT-based attenuation map was registered to the UTE image of the coil for attenuation and scatter correction. After phantom validation, the effect of the carotid coil attenuation and the attenuation correction method were evaluated in five subjects. Phantom studies indicated that the overall loss of PET counts due to the coil was 6.3% with local region-of-interest (ROI) errors reaching up to 18.8%. Our registration method to correct for attenuation from the coil decreased the global error and local error (ROI) to 0.8% and 3.8%, respectively. The proposed registration method accurately captured the location and shape of the coil with a maximum spatial error of 2.6 mm. Quantitative analysis in human studies correlated with the phantom findings, but was dependent on the size of the ROI used in the analysis. MR coils result in significant error in PET quantification and thus attenuation correction is needed. The proposed strategy provides an operator-free method for attenuation and scatter correction for a flexible MRI carotid surface coil for routine clinical use.

  4. Markerless attenuation correction for carotid MRI surface receiver coils in combined PET/MR imaging.

    PubMed

    Eldib, Mootaz; Bini, Jason; Robson, Philip M; Calcagno, Claudia; Faul, David D; Tsoumpas, Charalampos; Fayad, Zahi A

    2015-06-21

    The purpose of the study was to evaluate the effect of attenuation of MR coils on quantitative carotid PET/MR exams. Additionally, an automated attenuation correction method for flexible carotid MR coils was developed and evaluated. The attenuation of the carotid coil was measured by imaging a uniform water phantom injected with 37 MBq of 18F-FDG in a combined PET/MR scanner for 24 min with and without the coil. In the same session, an ultra-short echo time (UTE) image of the coil on top of the phantom was acquired. Using a combination of rigid and non-rigid registration, a CT-based attenuation map was registered to the UTE image of the coil for attenuation and scatter correction. After phantom validation, the effect of the carotid coil attenuation and the attenuation correction method were evaluated in five subjects. Phantom studies indicated that the overall loss of PET counts due to the coil was 6.3% with local region-of-interest (ROI) errors reaching up to 18.8%. Our registration method to correct for attenuation from the coil decreased the global error and local error (ROI) to 0.8% and 3.8%, respectively. The proposed registration method accurately captured the location and shape of the coil with a maximum spatial error of 2.6 mm. Quantitative analysis in human studies correlated with the phantom findings, but was dependent on the size of the ROI used in the analysis. MR coils result in significant error in PET quantification and thus attenuation correction is needed. The proposed strategy provides an operator-free method for attenuation and scatter correction for a flexible MRI carotid surface coil for routine clinical use.

  5. Cryptic parasite revealed improved prospects for treatment and control of human cryptosporidiosis through advanced technologies.

    PubMed

    Jex, Aaron R; Smith, Huw V; Nolan, Matthew J; Campbell, Bronwyn E; Young, Neil D; Cantacessi, Cinzia; Gasser, Robin B

    2011-01-01

    Cryptosporidium is an important genus of parasitic protozoa of humans and other vertebrates and is a major cause of intestinal disease globally. Unlike many common causes of infectious enteritis, there are no widely available, effective vaccine or drug-based intervention strategies for Cryptosporidium, and control is focused mainly on prevention. This approach is particularly deficient for infections of severely immunocompromised and/or suppressed, the elderly or malnourished people. However, cryptosporidiosis also presents a significant burden on immunocompetent individuals, and can, for example have lasting effects on the physical and mental development of children infected at an early age. In the last few decades, our understanding of Cryptosporidium has expanded significantly in numerous areas, including the parasite life-cycle, the processes of excystation, cellular invasion and reproduction, and the interplay between parasite and host. Nonetheless, despite extensive research, many aspects of the biology of Cryptosporidium remain unknown, and treatment and control are challenging. Here, we review the current state of knowledge of Cryptosporidium, with a focus on major advances arising from the recently completed genome sequences of the two species of greatest relevance in humans, namely Cryptosporidium hominis and Cryptosporidium parvum. In addition, we discuss the potential of next-generation sequencing technologies, new advances in in silico analyses and progress in in vitro culturing systems to bridge these gaps and to lead toward effective treatment and control of cryptosporidiosis.

  6. Identifying human disease genes: advances in molecular genetics and computational approaches.

    PubMed

    Bakhtiar, S M; Ali, A; Baig, S M; Barh, D; Miyoshi, A; Azevedo, V

    2014-07-04

    The human genome project is one of the significant achievements that have provided detailed insight into our genetic legacy. During the last two decades, biomedical investigations have gathered a considerable body of evidence by detecting more than 2000 disease genes. Despite the imperative advances in the genetic understanding of various diseases, the pathogenesis of many others remains obscure. With recent advances, the laborious methodologies used to identify DNA variations are replaced by direct sequencing of genomic DNA to detect genetic changes. The ability to perform such studies depends equally on the development of high-throughput and economical genotyping methods. Currently, basically for every disease whose origen is still unknown, genetic approaches are available which could be pedigree-dependent or -independent with the capacity to elucidate fundamental disease mechanisms. Computer algorithms and programs for linkage analysis have formed the foundation for many disease gene detection projects, similarly databases of clinical findings have been widely used to support diagnostic decisions in dysmorphology and general human disease. For every disease type, genome sequence variations, particularly single nucleotide polymorphisms are mapped by comparing the genetic makeup of case and control groups. Methods that predict the effects of polymorphisms on protein stability are useful for the identification of possible disease associations, whereas structural effects can be assessed using methods to predict stability changes in proteins using sequence and/or structural information.

  7. The prognosis of carotid siphon stenosis.

    PubMed

    Wechsler, L R; Kistler, J P; Davis, K R; Kaminski, M J

    1986-01-01

    We retrospectively reviewed the clinical course and angiograms of 15 patients with carotid siphon stenosis of 50% or greater. Fourteen had less than 50% stenosis at the origin of the ipsilateral internal carotid artery, and one had a greater degree of stenosis but underwent endarterectomy after an initial angiogram. Angiograms were examined for evidence of hemodynamic abnormalities in addition to residual lumen diameter. Seven patients initially had TIAs, 5 had strokes, and 3 were asymptomatic. In an average followup of 51 months (range 4-123 months) subsequent cerebral ischemic events occurred in 6 (40%), but only 1 had a stroke with a persisting neurological deficit that could be directly attributed to the siphon stenosis. Stenoses were hemodynamically significant by angiography in 5 of 7 TIA patients, and only 1 of 5 stroke patients. The incidence of subsequent ischemic events in this study was similar to 2 previous studies of siphon stenosis, however in this study most of the events ipsilateral to the siphon stenosis were TIAs or minor strokes. The association of hemodynamic angiographic abnormalities and initial TIAs but not strokes suggests that the mechanism producing ischemic symptoms may differ in patients with TIA and stroke who have carotid siphon stenosis.

  8. The anterior loop of the carotid siphon.

    PubMed

    Alencastro, L C

    1991-01-01

    The extracavernous-presubarachnoid segment of the carotid artery (EPCA), medial to the clinoid process, was studied in 48 sphenoid bones. Ten specimens were submitted to microdissection; the remainders were cut in 1 mm thick slices after electrolytic decalcification. The studies showed that the EPCA has a mean length of 3.09 mm (0.5 to 6.5 mm). It has a shorter length than the whole medioclinoid (paraclinoid) segment of the artery because the subarachnoid space may enter between the artery and the clinoid process, as well as the venous space of the cavernous sinus. Venous channels of extremely small diameter were found between the EPCA and the clinoid process in 30.3% of the cases and between the EPCA and the sphenoid body in 48.6%. The distal limit of the intracavernous cartoid artery is the projection of the caudal surface of the clinoid process, which is coincident with the vertex of the anterior loop of the carotid siphon in 91.7% of the cases. The origin of the ophthalmic artery was verified to be from the EPCA in 9.7%, at the transition to the subarachnoid space in 6.5%, and intracavernous in 3.2%. Immediately proximal to the EPCA, the anterior horizontal segment of the carotid artery may be reached without entering the venous space of the cavernous sinus through the superior wall in 27.8% and through the lateral wall in 66.6%.

  9. Carotid artery rupture and cervicofacial actinomycosis.

    PubMed

    Kummer, Anne; Lhermitte, Benoît; Ödman, Micaela; Grabherr, Silke; Mangin, Patrice; Palmiere, Cristian

    2012-11-01

    Cervicofacial actinomycosis is an uncommon, progressive infection caused by bacilli of the Actinomyces genus. Actinomyces are common commensal saprophytes in the oral cavity which may have medical importance as facultative pathogens. Subsequent to local injuries to the oral mucosa, they may penetrate the deep tissues and be responsible for suppurative or granulomatous infections. We herein report a case of a 65-year-old man who underwent surgery followed by chemotherapy and radiotherapy for a tonsillar carcinoma. An ulcerous lesion in the base of the tongue developed and spread to the carotid artery wall. The man died of a massive hemorrhage due to left carotid artery rupture. Postmortem computed tomography angiography performed prior to autopsy allowed the precise localization of the source of bleeding to be detected. Postmortem biochemical investigations confirmed the presence of inflammation associated with local bacterial infection. Histological investigations revealed the rupture of the left carotid artery surrounded by numerous colonies of Actinomyces. Acute and chronic inflammation with tissue necrosis as well as post-actinic, fibrotic changes were also found in the tissues surrounding the ruptured artery wall. PMID:22819527

  10. Noninvasive evaluation and management of the "asymptomatic" carotid bruit.

    PubMed

    Kartchner, M M; McRae, L P

    1977-12-01

    Cervical bruits in patients who are asymptomatic or who have nonhemispheric neurological symptoms present a universal challenge. Of 4,000 patients evaluated noninvasively for carotid occlusive disease, 1,287 presented with "asymptomatic" bruits (697 had nonhemispheric neurological symptoms and 590 were clinically asymptomatic). Carotid phonoangiography (CPA), the visual analysis of carotid bruits, identifies bruits indicative of significant stenosis, documents progression, and differentiates bruits of carotid bifurcation and sub-bifurcation origin. Sub-bifurication bruits were diagnosed in 619, insignificant bifurcation bruits in 426, and significant carotid bruits in 242 patients by CPA. Oculoplethysmography (OPG) evaluates the hemodynamic significance of carotid bruits by comparative timing of simultaneously recorded ocular and ear lobe pulses. OPG detected 273 asymptomatic bruit patients with significant internal carotid flow reduction and indicated 5% of the bifurcation bruits were of external carotid origin. An accuracy of 89% in determining greater than 40% stenosis by OPG/CPA in 295 patients having arteriography increases to 97% when both OPG and CPA are positive. Six-month to 70-month clinical follow-up of the 1,287 patients documented 154 carotid endarterectomies and 38 strokes. Analysis of the strokes favors arteriography and operation only for those patients with appropriately positive or progressive OPG/CPA or with focal transient ischemic attacks (TIAs).

  11. [An integrated segmentation method for 3D ultrasound carotid artery].

    PubMed

    Yang, Xin; Wu, Huihui; Liu, Yang; Xu, Hongwei; Liang, Huageng; Cai, Wenjuan; Fang, Mengjie; Wang, Yujie

    2013-07-01

    An integrated segmentation method for 3D ultrasound carotid artery was proposed. 3D ultrasound image was sliced into transverse, coronal and sagittal 2D images on the carotid bifurcation point. Then, the three images were processed respectively, and the carotid artery contours and thickness were obtained finally. This paper tries to overcome the disadvantages of current computer aided diagnosis method, such as high computational complexity, easily introduced subjective errors et al. The proposed method could get the carotid artery overall information rapidly, accurately and completely. It could be transplanted into clinical usage for atherosclerosis diagnosis and prevention. PMID:24195385

  12. Heart research advances using database search engines, Human Protein Atlas and the Sydney Heart Bank.

    PubMed

    Li, Amy; Estigoy, Colleen; Raftery, Mark; Cameron, Darryl; Odeberg, Jacob; Pontén, Fredrik; Lal, Sean; Dos Remedios, Cristobal G

    2013-10-01

    This Methodological Review is intended as a guide for research students who may have just discovered a human "novel" cardiac protein, but it may also help hard-pressed reviewers of journal submissions on a "novel" protein reported in an animal model of human heart failure. Whether you are an expert or not, you may know little or nothing about this particular protein of interest. In this review we provide a strategic guide on how to proceed. We ask: How do you discover what has been published (even in an abstract or research report) about this protein? Everyone knows how to undertake literature searches using PubMed and Medline but these are usually encyclopaedic, often producing long lists of papers, most of which are either irrelevant or only vaguely relevant to your query. Relatively few will be aware of more advanced search engines such as Google Scholar and even fewer will know about Quertle. Next, we provide a strategy for discovering if your "novel" protein is expressed in the normal, healthy human heart, and if it is, we show you how to investigate its subcellular location. This can usually be achieved by visiting the website "Human Protein Atlas" without doing a single experiment. Finally, we provide a pathway to discovering if your protein of interest changes its expression level with heart failure/disease or with ageing.

  13. Percutaneous Injection of Lidocaine Within the Carotid Body Area in Carotid Artery Stenting: An 'Old-New' Technique

    SciTech Connect

    Mourikis, Dimitrios; Chatoupis, Konstantinos; Katsenis, Konstantinos; Vlahos, Lampros; Chatziioannou, Achilles

    2008-07-15

    Severe bradycardia is a common untoward effect during balloon angioplasty when performing carotid artery stenting. Therefore atropine injection even before dilatation and the presence of an anesthesiologist are advocated in all patients. In the surgical literature, injection of a local anesthetic agent into the carotid sinus before carotid endarterectomy was performed in an attempt to ameliorate perioperative hemodynamic instability. This study was undertaken to test the hypothesis that percutaneous infiltration of the carotid sinus with local anesthetic immediately before balloon dilatation reduces bradycardia and ameliorates the need for atropine injection or the presence of an anesthesiologist. Infiltration of the carotid sinus with 5 ml of 1% lidocaine, 3 min before dilatation, was performed in 30 consecutive patients. No one exhibited any significant rhythm change that required atropine injection. The anesthesiologist did not face any hemodynamic instability during the carotid artery stenting procedure.

  14. Quality assurance and risk management: Perspectives on Human Factors Certification of Advanced Aviation Systems

    NASA Technical Reports Server (NTRS)

    Taylor, Robert M.; Macleod, Iain S.

    1994-01-01

    This paper is based on the experience of engineering psychologists advising the U.K. Ministry of Defense (MoD) on the procurement of advanced aviation systems that conform to good human engineering (HE) practice. Traditional approaches to HE in systems procurement focus on the physical nature of the human-machine interface. Advanced aviation systems present increasingly complex design requirements for human functional integration, information processing, and cognitive task performance effectiveness. These developing requirements present new challenges for HE quality assurance (QA) and risk management, requiring focus on design processes as well as on design content or product. A new approach to the application of HE, recently adopted by NATO, provides more systematic ordering and control of HE processes and activities to meet the challenges of advanced aircrew systems design. This systematic approach to HE has been applied by MoD to the procurement of mission systems for the Royal Navy Merlin helicopter. In MoD procurement, certification is a judicial function, essentially independent of the service customer and industry contractor. Certification decisions are based on advice from MoD's appointed Acceptance Agency. Test and evaluation (T&E) conducted by the contractor and by the Acceptance Agency provide evidence for certification. Certification identifies limitations of systems upon release to the service. Evidence of compliance with HE standards traditionally forms the main basis of HE certification and significant non-compliance could restrict release. The systems HE approach shows concern for the quality of processes as well as for the content of the product. Human factors certification should be concerned with the quality of HE processes as well as products. Certification should require proof of process as well as proof of content and performance. QA criteria such as completeness, consistency, timeliness, and compatibility provide generic guidelines for

  15. Correlation of Respirator Fit Measured on Human Subjects and a Static Advanced Headform

    PubMed Central

    Bergman, Michael S.; He, Xinjian; Joseph, Michael E.; Zhuang, Ziqing; Heimbuch, Brian K.; Shaffer, Ronald E.; Choe, Melanie; Wander, Joseph D.

    2015-01-01

    This study assessed the correlation of N95 filtering face-piece respirator (FFR) fit between a Static Advanced Headform (StAH) and 10 human test subjects. Quantitative fit evaluations were performed on test subjects who made three visits to the laboratory. On each visit, one fit evaluation was performed on eight different FFRs of various model/size variations. Additionally, subject breathing patterns were recorded. Each fit evaluation comprised three two-minute exercises: “Normal Breathing,” “Deep Breathing,” and again “Normal Breathing.” The overall test fit factors (FF) for human tests were recorded. The same respirator samples were later mounted on the StAH and the overall test manikin fit factors (MFF) were assessed utilizing the recorded human breathing patterns. Linear regression was performed on the mean log10-transformed FF and MFF values to assess the relationship between the values obtained from humans and the StAH. This is the first study to report a positive correlation of respirator fit between a headform and test subjects. The linear regression by respirator resulted in R2 = 0.95, indicating a strong linear correlation between FF and MFF. For all respirators the geometric mean (GM) FF values were consistently higher than those of the GM MFF. For 50% of respirators, GM FF and GM MFF values were significantly different between humans and the StAH. For data grouped by subject/respirator combinations, the linear regression resulted in R2 = 0.49. A weaker correlation (R2 = 0.11) was found using only data paired by subject/respirator combination where both the test subject and StAH had passed a real-time leak check before performing the fit evaluation. For six respirators, the difference in passing rates between the StAH and humans was < 20%, while two respirators showed a difference of 29% and 43%. For data by test subject, GM FF and GM MFF values were significantly different for 40% of the subjects. Overall, the advanced headform system has

  16. Correlation of respirator fit measured on human subjects and a static advanced headform.

    PubMed

    Bergman, Michael S; He, Xinjian; Joseph, Michael E; Zhuang, Ziqing; Heimbuch, Brian K; Shaffer, Ronald E; Choe, Melanie; Wander, Joseph D

    2015-01-01

    This study assessed the correlation of N95 filtering facepiece respirator (FFR) fit between a Static Advanced Headform (StAH) and 10 human test subjects. Quantitative fit evaluations were performed on test subjects who made three visits to the laboratory. On each visit, one fit evaluation was performed on eight different FFRs of various model/size variations. Additionally, subject breathing patterns were recorded. Each fit evaluation comprised three two-minute exercises: "Normal Breathing," "Deep Breathing," and again "Normal Breathing." The overall test fit factors (FF) for human tests were recorded. The same respirator samples were later mounted on the StAH and the overall test manikin fit factors (MFF) were assessed utilizing the recorded human breathing patterns. Linear regression was performed on the mean log10-transformed FF and MFF values to assess the relationship between the values obtained from humans and the StAH. This is the first study to report a positive correlation of respirator fit between a headform and test subjects. The linear regression by respirator resulted in R(2) = 0.95, indicating a strong linear correlation between FF and MFF. For all respirators the geometric mean (GM) FF values were consistently higher than those of the GM MFF. For 50% of respirators, GM FF and GM MFF values were significantly different between humans and the StAH. For data grouped by subject/respirator combinations, the linear regression resulted in R(2) = 0.49. A weaker correlation (R(2) = 0.11) was found using only data paired by subject/respirator combination where both the test subject and StAH had passed a real-time leak check before performing the fit evaluation. For six respirators, the difference in passing rates between the StAH and humans was < 20%, while two respirators showed a difference of 29% and 43%. For data by test subject, GM FF and GM MFF values were significantly different for 40% of the subjects. Overall, the advanced headform system has potential

  17. Impact of Serum High Mobility Group Box 1 and Soluble Receptor for Advanced Glycation End-Products on Subclinical Atherosclerosis in Patients with Granulomatosis with Polyangiitis

    PubMed Central

    de Souza, Alexandre W. S.; de Leeuw, Karina; van Timmeren, Mirjan M.; Limburg, Pieter C.; Stegeman, Coen A.; Bijl, Marc; Westra, Johanna; Kallenberg, Cees G. M.

    2014-01-01

    The objective of this study was to evaluate whether levels of high mobility group box 1 (HMGB1) in granulomatosis with polyangiitis (GPA) patients are associated with carotid atherosclerosis, related to levels of soluble receptor for advanced glycation end-products (sRAGE) and influenced by immunosuppressive or lipid-lowering therapy. Twenty-three GPA patients and 20 controls were evaluated for HMGB1- and sRAGE levels and for carotid atherosclerosis using ultrasound to determine intima-media thickness (IMT). In vitro the effect of atorvastatin on the production of HMGB1 by lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVEC) was assessed. Serum HMGB1 and sRAGE levels did not differ between patients and controls. A negative correlation was found between sRAGE and maximum IMT but HMGB1 and carotid IMT were not related. HMGB1 levels were reduced in GPA patients on statins and prednisolone. In vitro, atorvastatin reduced HMGB1 levels in supernatants of activated HUVEC. In conclusion, carotid IMT is inversely correlated with sRAGE levels but not with HMGB1 levels. Statins and prednisolone are associated with reduced serum HMGB1 levels and atorvastatin decreases HMGB1 release by activated HUVEC in vitro, indicating an additional anti-inflammatory effect of statins. PMID:24776932

  18. Carotid artery stenting versus endarterectomy: a systematic review.

    PubMed

    Gahremanpour, Amir; Perin, Emerson C; Silva, Guilherme

    2012-01-01

    For about 2 decades, investigators have been comparing carotid endarterectomy with carotid artery stenting in regard to their effectiveness and safety in treating carotid artery stenosis. We conducted a systematic review to summarize and appraise the available evidence provided by randomized trials, meta-analyses, and registries comparing the clinical outcomes of the 2 procedures. We searched the MEDLINE, SciVerse Scopus, and Cochrane databases and the bibliographies of pertinent textbooks and articles to identify these studies. The results of clinical trials and, consequently, the meta-analyses of those trials produced conflicting results regarding the comparative effectiveness and safety of carotid endarterectomy and carotid stenting. These conflicting results arose because of differences in patient population, trial design, outcome measures, and variability among centers in the endovascular devices used and in operator skills. Careful appraisal of the trials and meta-analyses, particularly the most recent and largest National Institutes of Health-sponsored trial (the Carotid Revascularization Endarterectomy vs Stenting Trial [CREST]), showed that carotid stenting and endarterectomy were associated with similar rates of death and disabling stroke. Within the 30-day periprocedural period, carotid stenting was associated with higher risks of stroke, especially for patients aged >70 years, whereas carotid endarterectomy was associated with a higher risk of myocardial infarction. The slightly higher cost of stenting compared with endarterectomy was within an acceptable range by cost-effectiveness standards. We conclude that carotid artery stenting is an equivalent alternative to carotid endarterectomy when patient age and anatomy, surgical risk, and operator experience are considered in the choice of treatment approach. PMID:22949763

  19. Dietary advanced lipid oxidation endproducts are risk factors to human health.

    PubMed

    Kanner, Joseph

    2007-09-01

    Lipid oxidation in foods is one of the major degradative processes responsible for losses in food quality. The oxidation of unsaturated fatty acids results in significant generation of dietary advanced lipid oxidation endproducts (ALEs) which are in part cytotoxic and genotoxic compounds. The gastrointestinal tract is constantly exposed to dietary oxidized food compounds, after digestion a part of them are absorbed into the lymph or directly into the blood stream. After ingestion of oxidized fats animals and human have been shown to excrete in urine increase amounts of malondialdehyde but also lipophilic carbonyl compounds. Oxidized cholesterol in the diet was found to be a source of oxidized lipoproteins in human serum. Some of the dietary ALEs, which are absorbed from the gut to the circulatory system, seems to act as injurious chemicals that activate an inflammatory response which affects not only circulatory system but also organs such as liver, kidney, lung, and the gut itself. We believe that repeated consumption of oxidized fat in the diet poses a chronic threat to human health. High concentration of dietary antioxidants could prevent lipid oxidation and ALEs generation not only in foods but also in stomach condition and thereby potentially decrease absorption of ALEs from the gut. This could explains the health benefit of diets containing large amounts of dietary antioxidants such those present in fruits and vegetables, or products such as red-wine or tea consuming during the meal. PMID:17854006

  20. Dietary advanced lipid oxidation endproducts are risk factors to human health.

    PubMed

    Kanner, Joseph

    2007-09-01

    Lipid oxidation in foods is one of the major degradative processes responsible for losses in food quality. The oxidation of unsaturated fatty acids results in significant generation of dietary advanced lipid oxidation endproducts (ALEs) which are in part cytotoxic and genotoxic compounds. The gastrointestinal tract is constantly exposed to dietary oxidized food compounds, after digestion a part of them are absorbed into the lymph or directly into the blood stream. After ingestion of oxidized fats animals and human have been shown to excrete in urine increase amounts of malondialdehyde but also lipophilic carbonyl compounds. Oxidized cholesterol in the diet was found to be a source of oxidized lipoproteins in human serum. Some of the dietary ALEs, which are absorbed from the gut to the circulatory system, seems to act as injurious chemicals that activate an inflammatory response which affects not only circulatory system but also organs such as liver, kidney, lung, and the gut itself. We believe that repeated consumption of oxidized fat in the diet poses a chronic threat to human health. High concentration of dietary antioxidants could prevent lipid oxidation and ALEs generation not only in foods but also in stomach condition and thereby potentially decrease absorption of ALEs from the gut. This could explains the health benefit of diets containing large amounts of dietary antioxidants such those present in fruits and vegetables, or products such as red-wine or tea consuming during the meal.

  1. Biological effects of space radiation on human cells: history, advances and outcomes.

    PubMed

    Maalouf, Mira; Durante, Marco; Foray, Nicolas

    2011-01-01

    Exposure to radiation is one of the main concerns for space exploration by humans. By focusing deliberately on the works performed on human cells, we endeavored to review, decade by decade, the technological developments and conceptual advances of space radiation biology. Despite considerable efforts, the cancer and the toxicity risks remain to be quantified: 1) the nature and the frequency of secondary heavy ions need to be better characterized in order to estimate their contribution to the dose and to the final biological response; 2) the diversity of radiation history of each astronaut and the impact of individual susceptibility make very difficult any epidemiological analysis for estimating hazards specifically due to space radiation exposure. 3) Cytogenetic data undoubtedly revealed that space radiation exposure produce significant damage in cells. However, our knowledge of the basic mechanisms specific to low-dose, to repeated doses and to adaptive response is still poor. The application of new radiobiological techniques, like immunofluorescence, and the use of human tissue models different from blood, like skin fibroblasts, may help in clarifying all the above items. PMID:21436608

  2. [Advances in the experimental analysis of behavior: issues of choice behavior, comparative cognition, and human language].

    PubMed

    Sakagami, T; Yamamoto, J; Jitsumori, M

    1994-12-01

    As the opportunity to contact with related areas has increased, the study of of the experimental analysis of behavior has experienced revolutionary changes. Some of the most active and important areas-studies of choice, comparative cognition, and human language--are reviewed to acquaint readers. Studies of CHOICE have linked to the molar theories of behavioral economics and behavioral ecology, which promoted research of choice by animals under uncertainty conditions. Further approach has been made to integrate the molar and molecular analyses on the basis of the ideas of behavior dynamics. COMPARATIVE COGNITION is a part of a larger field including cognitive science, behavioral neuroscience, and biological science. Recent developments, aided with a comparative perspective, made significant contributions to our understanding of the phylogeny and ontogeny of cognition. Advances in analysis of human behavior provided tools to study behavioral aspects of semantics, syntax, and pragmatics of HUMAN LANGUAGE. Using the paradigm of stimulus equivalence, the emergence of stimulus relations, stimulus-stimulus networks, hierarchical structure of verbal behavior, and other language-related behaviors have been investigated.

  3. Differential oxidative status and immune characterization of the early and advanced stages of human breast cancer.

    PubMed

    Panis, C; Victorino, V J; Herrera, A C S A; Freitas, L F; De Rossi, T; Campos, F C; Simão, A N Colado; Barbosa, D S; Pinge-Filho, P; Cecchini, R; Cecchini, A L

    2012-06-01

    Breast cancer is the malignant neoplasia with the highest incidence in women worldwide. Chronic oxidative stress and inflammation have been indicated as major mediators during carcinogenesis and cancer progression. Human studies have not considered the complexity of tumor biology during the stages of cancer advance, limiting their clinical application. The purpose of this study was to characterize systemic oxidative stress and immune response parameters in early (ED; TNM I and II) and advanced disease (AD; TNM III and IV) of patients diagnosed with infiltrative ductal carcinoma breast cancer. Oxidative stress parameters were evaluated by plasmatic lipoperoxidation, carbonyl content, thiobarbituric reactive substances (TBARS), nitric oxide levels (NO), total radical antioxidant parameter (TRAP), superoxide dismutase, and catalase activities and GSH levels. Immune evaluation was determined by TNF-α, IL-1β, IL-12, and IL-10 levels and leukocytes oxidative burst evaluation by chemiluminescence. Tissue damage analysis included heart (total CK and CKMB), liver (AST, ALT, GGT), and renal (creatinine, urea, and uric acid) plasmatic markers. C-reactive protein (CRP) and iron metabolism were also evaluated. Analysis of the results verified different oxidative stress statuses occur at distinct cancer stages. ED was characterized by reduction in catalase, 8-isoprostanes, and GSH levels, with enhanced lipid peroxidation and TBARS levels. AD exhibited more pronounced oxidative status, with reduction in catalase activity and TRAP, intense lipid peroxidation and high levels of NO, TBARs, and carbonyl content. ED patients presented a Th2 immune pattern, while AD exhibited Th1 status. CRP levels and ferritin were increased in both stages of disease. Leukocytes burst impairment was observed in both the groups. Plasma iron levels were significantly elevated in AD. The data obtained indicated that oxidative stress enhancement and immune response impairment may be necessary to ensure

  4. Numerical simulation of blood flow and plaque progression in carotid-carotid bypass patient specific case.

    PubMed

    Filipovic, Nenad; Saveljic, Igor; Nikolic, Dalibor; Milosevic, Zarko; Kovacevic, Pavle; Velicki, Lazar

    2015-01-01

    This study describes computer simulation of blood flow and plaque progression pattern in a patient who underwent surgical treatment for infected carotid prosthetic tube graft using carotid-carotid cross-over bypass. The 3D blood flow is governed by the Navier-Stokes equations, together with the continuity equation. Mass transfer within the blood lumen and through the arterial wall is coupled with the blood flow and is modelled by the convection-diffusion equation. Low-density lipoprotein (LDL) transport in lumen of the vessel is described by Kedem-Katchalsky equations. The inflammatory process is solved using three additional reaction-diffusion partial differential equations. Calculation based on a computer simulation showed that flow distribution in the left carotid artery (CA) was around 40-50% of the total flow in the right common CA. Also, the left CA had higher pressure gradient after surgical intervention. Plaque progression simulation predicted development of the atherosclerotic plaque in the position of the right common CA and the left internal CA. A novel way of atherosclerotic plaque progression modelling using computer simulation shows a potential clinical benefit with significant impact on the treatment strategy optimization. PMID:26291584

  5. Human factors engineering guidance for the review of advanced alarm systems

    SciTech Connect

    O`Hara, J.M.; Brown, W.S.; Higgins, J.C.; Stubler, W.F.

    1994-09-01

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout.

  6. Computational methods to extract meaning from text and advance theories of human cognition.

    PubMed

    McNamara, Danielle S

    2011-01-01

    Over the past two decades, researchers have made great advances in the area of computational methods for extracting meaning from text. This research has to a large extent been spurred by the development of latent semantic analysis (LSA), a method for extracting and representing the meaning of words using statistical computations applied to large corpora of text. Since the advent of LSA, researchers have developed and tested alternative statistical methods designed to detect and analyze meaning in text corpora. This research exemplifies how statistical models of semantics play an important role in our understanding of cognition and contribute to the field of cognitive science. Importantly, these models afford large-scale representations of human knowledge and allow researchers to explore various questions regarding knowledge, discourse processing, text comprehension, and language. This topic includes the latest progress by the leading researchers in the endeavor to go beyond LSA.

  7. Computational methods to extract meaning from text and advance theories of human cognition.

    PubMed

    McNamara, Danielle S

    2011-01-01

    Over the past two decades, researchers have made great advances in the area of computational methods for extracting meaning from text. This research has to a large extent been spurred by the development of latent semantic analysis (LSA), a method for extracting and representing the meaning of words using statistical computations applied to large corpora of text. Since the advent of LSA, researchers have developed and tested alternative statistical methods designed to detect and analyze meaning in text corpora. This research exemplifies how statistical models of semantics play an important role in our understanding of cognition and contribute to the field of cognitive science. Importantly, these models afford large-scale representations of human knowledge and allow researchers to explore various questions regarding knowledge, discourse processing, text comprehension, and language. This topic includes the latest progress by the leading researchers in the endeavor to go beyond LSA. PMID:25164173

  8. Advances in microfluidic platforms for analyzing and regulating human pluripotent stem cells.

    PubMed

    Qian, Tongcheng; Shusta, Eric V; Palecek, Sean P

    2015-10-01

    Microfluidic devices employ submillimeter length scale control of flow to achieve high-resolution spatial and temporal control over the microenvironment, providing powerful tools to elucidate mechanisms of human pluripotent stem cell (hPSC) regulation and to elicit desired hPSC fates. In addition, microfluidics allow control of paracrine and juxtracrine signaling, thereby enabling fabrication of microphysiological systems comprised of multiple cell types organized into organs-on-a-chip. Microfluidic cell culture systems can also be integrated with actuators and sensors, permitting construction of high-density arrays of cell-based biosensors for screening applications. This review describes recent advances in using microfluidics to understand mechanisms by which the microenvironment regulates hPSC fates and applications of microfluidics to realize the potential of hPSCs for in vitro modeling and screening applications.

  9. Recent Advances in Diagnosis, Prevention, and Treatment of Human Respiratory Syncytial Virus

    PubMed Central

    Bawage, Swapnil Subhash; Tiwari, Pooja Munnilal; Singh, Shree Ram

    2013-01-01

    Human respiratory syncytial virus (RSV) is a common cause of respiratory infection in infants and the elderly, leading to significant morbidity and mortality. The interdisciplinary fields, especially biotechnology and nanotechnology, have facilitated the development of modern detection systems for RSV. Many anti-RSV compounds like fusion inhibitors and RNAi molecules have been successful in laboratory and clinical trials. But, currently, there are no effective drugs for RSV infection even after decades of research. Effective diagnosis can result in effective treatment, but the progress in both of these facets must be concurrent. The development in prevention and treatment measures for RSV is at appreciable pace, but the implementation into clinical practice still seems a challenge. This review attempts to present the promising diverse research approaches and advancements in the area of diagnosis, prevention, and treatment that contribute to RSV management. PMID:24382964

  10. Carotid and vertebrobasilar transient ischemic attacks: clinical and angiographic correlation.

    PubMed

    Ueda, K; Toole, J F; McHenry, L C

    1979-08-01

    Carotid and vertebrobasilar transient ischemic attacks (TIAs) were clinically and angiographically correlated in 85 patients who had four-vessel angiography within 2 weeks after a TIA. The patients were divided into carotid and vertebrobasilar groups by clinical criteria. In the correlations of symptoms with arteriography, lesions of the contralateral internal carotid artery were observed in 54 percent of the patients. Of 39 patients with vertebrobasilar symptoms, 34 percent also had one carotid lesion and six patients had combinations of symptoms of both carotid and vertebrobasilar disease. In correlation with carotid bruits of the 85 patients, bruits were heard over one carotid artery in 42 percent. Subclavian bruits were heard in 47 percent of the patients with vertebrobasilar symptomatology. TIAs owing to arteriosclerosis of the cervical arteries occurred in 85 percent of the patients, but there was no significant difference in the incidence of atherosclerosis-induced TIA in the carotid and vertebrobasilar systems. For accurate population surveys of the prevalence of TIAs, and for clinical decisions, proper categorization of patients is necessary.

  11. Stroke. Geometry is destiny for carotid atherosclerotic plaques.

    PubMed

    Fisher, Mark

    2011-01-01

    The geometry of carotid arteries, both normal and narrowed, produces flow characteristics that predict the location of atherosclerosis and the site of plaque rupture. A recent study has shown that the upstream carotid plaque undergoes profound biochemical and apoptotic changes that are closely linked to the development of stroke symptoms.

  12. Internal carotid artery dissection associated with scuba diving.

    PubMed

    Nelson, E E

    1995-01-01

    A 52-year-old man presented to the emergency department with dysphasia and a headache after scuba diving. He was treated initially for decompression sickness. Subsequent workup revealed bilateral internal carotid artery dissection. The risk factors, presenting symptoms, diagnosis, and treatment of internal carotid artery dissection are reviewed. The importance of considering unusual causes of neurologic deficits after scuba diving is emphasized.

  13. Traumatic internal carotid artery dissections caused by blunt softball injuries.

    PubMed

    Schievink, W I; Atkinson, J L; Bartleson, J D; Whisnant, J P

    1998-03-01

    This report describes recently treated patients with carotid artery dissection caused by blunt softball injuries, as well as the results of a study of carotid artery trauma in a community. Data obtained through the medical records linkage system used for epidemiologic studies in Olmsted County, MN were used to identify all cases of traumatic internal carotid artery dissection diagnosed from 1987 through 1994. Four patients with traumatic internal carotid artery dissections were identified during the 8-year period under study. In two patients (50%) the carotid dissection was a result of the direct impact of a softball. A 39-year-old-man, who developed transient cerebral ischemic symptoms, and a 35-year-old woman, who developed a painful Horner's syndrome, were struck by a softball on the anterolateral aspect of the neck. Both patients had a low carotid bifurcation. These data suggest that internal carotid artery dissections may be underrecognized sequelae of direct softball injuries to the anterolateral neck. A low carotid bifurcation may be a risk factor for such injuries.

  14. The Role of PPARγ in Advanced Glycation End Products-Induced Inflammatory Response in Human Chondrocytes

    PubMed Central

    Li, Yu-qing; Chen, Cheng; Cai, Wei; Zeng, Yue-lin

    2015-01-01

    Objective Advances made in the past ten years highlight the notion that peroxisome proliferator-activated receptors gamma (PPARγ) has protective properties in the pathophysiology of osteoarthritis (OA). The aim of this study was to define the roles of PPARγ in AGEs-induced inflammatory response in human chondrocytes. Methods Primary human chondrocytes were stimulated with AGEs in the presence or absence of neutralizing antibody against RAGE (anti-RAGE), MAPK specific inhibitors and PPARγ agonist pioglitazone. The expression of IL-1, MMP-13, TNF-α, PPARγ, nuclear NF-κB p65 and cytosol IκBα was determined by western blotting and real-time PCR. Results AGEs could enhance the expression of IL-1, TNF-α, and MMP-13, but the level of PPARγ was decreased in a time- and dose-dependent manner, which was inhibited by anti-RAGE, SB203580 (P38 MAPK specific inhibitor) and SP600125 (a selective inhibitor of JNK). PPARγ agonist pioglitazone could inhibit the effects of AGEs-induced inflammatory response and PPARγ down-regulation. In human chondrocytes, AGEs could induce cytosol IκBα degradation and increase the level of nuclear NF-κB p65, which was inhibited by PPARγ agonist pioglitazone. Conclusions In primary human chondrocytes, AGEs could down-regulate PPARγ expression and increase the inflammatory mediators, which could be reversed by PPARγ agonist pioglitazone. Activation of RAGE by AGEs triggers a cascade of downstream signaling, including MAPK JNK/ p38, PPARγ and NF-κB. Taken together, PPARγ could be a potential target for pharmacologic intervention in the treatment of OA. PMID:26024533

  15. A Probabilistic Risk Analysis (PRA) of Human Space Missions for the Advanced Integration Matrix (AIM)

    NASA Technical Reports Server (NTRS)

    Jones, Harry W.; Dillon-Merrill, Robin L.; Thomas, Gretchen A.

    2003-01-01

    The Advanced Integration Matrix (AIM) Project u7ill study and solve systems-level integration issues for exploration missions beyond Low Earth Orbit (LEO), through the design and development of a ground-based facility for developing revolutionary integrated systems for joint human-robotic missions. This paper describes a Probabilistic Risk Analysis (PRA) of human space missions that was developed to help define the direction and priorities for AIM. Risk analysis is required for all major NASA programs and has been used for shuttle, station, and Mars lander programs. It is a prescribed part of early planning and is necessary during concept definition, even before mission scenarios and system designs exist. PRA cm begin when little failure data are available, and be continually updated and refined as detail becomes available. PRA provides a basis for examining tradeoffs among safety, reliability, performance, and cost. The objective of AIM's PRA is to indicate how risk can be managed and future human space missions enabled by the AIM Project. Many critical events can cause injuries and fatalities to the crew without causing loss of vehicle or mission. Some critical systems are beyond AIM's scope, such as propulsion and guidance. Many failure-causing events can be mitigated by conducting operational tests in AIM, such as testing equipment and evaluating operational procedures, especially in the areas of communications and computers, autonomous operations, life support, thermal design, EVA and rover activities, physiological factors including habitation, medical equipment, and food, and multifunctional tools and repairable systems. AIM is well suited to test and demonstrate the habitat, life support, crew operations, and human interface. Because these account for significant crew, systems performance, and science risks, AIM will help reduce mission risk, and missions beyond LEO are far enough in the future that AIM can have significant impact.

  16. Opening the Solar System: An Advanced Nuclear Spacecraft for Human Exploration

    NASA Technical Reports Server (NTRS)

    Werka, R. O.; Percy, T. K.

    2014-01-01

    Human exploration of the solar system is limited by our technology, not our imagination. We dream of a time when we can freely travel among the planets and truly become a spacefaring people. However, the current state of our technology limits our options for architecting missions to other planets. Instead of sailing the seas of space in the way that we cruise the seas of Earth, our limited propulsion technology requires us to depart Earth on a giant cluster of gas tanks and return in a lifeboat. This inefficient approach to exploration is evident in many of today's leading mission plans for human flights to Mars, asteroids, and other destinations. The cost and complexity of this approach to mission architecting makes it extremely difficult to realize our dreams of exploration beyond Low Earth Orbit (LEO). This does not need to be the case. Researchers at NASA's Marshall Space Flight Center (MSFC) have been investigating the feasibility of a new take on nuclear propulsion with the performance to enable a paradigm shift in human space exploration. During the fall of 2013, engineers at MSFC's Advanced Concepts Office developed a spacecraft concept (pictured below) around this new propulsion technology and redefined the human Mars mission to show its full potential. This spacecraft, which can be launched with a fleet of soon-to-be available SLS launch vehicles, is fueled primarily with hydrogen, and is fully reusable with no staging required. The reusable nature of this design enables a host of alternative mission architectures that more closely resemble an ocean voyage than our current piecemeal approach to exploration.

  17. Receptors for advanced glycosylation endproducts in human brain: role in brain homeostasis.

    PubMed Central

    Li, J. J.; Dickson, D.; Hof, P. R.; Vlassara, H.

    1998-01-01

    BACKGROUND: Advanced glycation end products (AGEs) are the reactive derivatives of nonenzymatic glucose-macromolecule condensation products. Aging human tissues accumulate AGEs in an age-dependent manner and contribute to age-related functional changes in vital organs. We have shown previously that AGE scavenger receptors are present on monocyte/macrophages, lymphocytes, and other cells. However, it remains unclear whether the human brain can efficiently eliminate AGE-modified proteins and whether excessive AGEs can contribute to inflammatory changes leading to brain injury in aging. MATERIALS AND METHODS: To explore the expression and characteristics of AGE-binding proteins on CNS glia components and their putative function, such as degradation of AGE-modified proteins, primary human astrocytes and human monocytes (as a microglial cell surrogate) and murine microglia (N9) cells and cell membrane extracts were used. Immunohistochemistry was used to examine the distribution of AGE-binding proteins in the human hippocampus; RT-PCR techniques were used to examine the biologic effects of AGEs and a model AGE compound, FFI, on AGE-binding protein modulation and cytokine responses of human astrocytes and monocytes. RESULTS: Our results showed that AGE-binding proteins AGE-R1, -R2, and -R3 are present in glial cells. Western blot analyses and radiolabeled ligand binding studies show that AGE-R1 and -R3 from human astrocytes bind AGE-modified proteins; binding could be blocked by anti-AGE-R1 and anti-AGE-R3 antibodies, respectively. Immunohistochemistry showed that AGE-R1 and -R2 are expressed mainly in neurons; only some glial cells express these AGE-binding proteins. In contrast, AGE-R3 was found only on those astrocytes whose positively stained foot processes extend and surround the sheath of microcapillaries. RT-PCR results showed that mRNAs of the three AGE-binding proteins are expressed constitutively in human astrocytes and monocytes, and receptor transcripts are

  18. Micro-CT of Carotid Arteries: A Tool for Experimental Studies

    SciTech Connect

    Mohr, Andreas; Wenke, Ruediger; Roemer, Frank W.; Lynch, John A.; Gatzka, Christian; Priebe, Markus; Guermazi, Ali; Grigorian, Mikayel; Heller, Martin; Mueller-Huelsbeck, Stefan

    2004-11-15

    Micro-computed tomography (micro-CT) is a high-resolution, nondestructive tool for two- and three-dimensional imaging and quantification. The ability of this technique to assess atherosclerosis of the carotid artery was evaluated in three human cadaver samples based on the original axial acquisitions, multiplanar reconstructions and volume rendering techniques. Quantitative analysis included the calculation of: (1) the original lumen perimeter, original lumen area, plaque area, residual lumen area, calcified area and gross sectional area reduction of the vascular lumen from two-dimensional slices; (2) the total tissue volume, soft tissue volume and calcified tissue volume from the three-dimensional data set. This preliminary study demonstrates the potential of micro-CT as a supplementary method for the two- and three-dimensional ex vivo evaluation of carotid atherosclerosis.

  19. [Ophthalmological complications associated with clinically significant carotid stenosis].

    PubMed

    Rozegnał-Madej, Agnieszka; Bielecka, Emilia; Swiech-Zubilewicz, Anna; Zarnowski, Tomasz; Karakuła, Wacław; Zubilewicz, Tomasz

    2012-01-01

    The aim of the study was to show ocular manifestations in carotid artery occlusive disease, with pathogenesis, diagnostic and therapeutic abilities of this changes. Carotid arteries are the main route by which the blood is supplied to the cerebrum and eyes. Clinical significant carotid artery stenosis is mainly caused by atherosclerosis. Most frequent neurological symptoms are transient ischemic attacks (TIA) and temporary visual loss (amaurosos fugax) are most common ocular symptoms. Other ocular pathologies in fundus examination are retinal embolies, retinal vein occlusion, anterior ischemic optic neuropathy, ocular ischemic syndrome or glaucoma. Most dangerous complications are stroke, blindness, or even patients death. Besides clinical examination the diagnosis is usually confirmed by carotid artery color Doppler ultrasound, magnetic resonance angiography and retinal fluorescein angiography. It is important to refer a patient with suspected or confirmed significant carotid artery stenosis for appropriate evaluation and treatment to a endovascular surgeon. PMID:22783748

  20. Everted cervical vein for carotid patch angioplasty.

    PubMed

    Yu, A; Dardik, H; Wolodiger, F; Raccuia, J; Kapadia, I; Sussman, B; Kahn, M; Pecoraro, J P; Ibrahim, I M

    1990-11-01

    Because of the theoretic benefits of autologous vein we undertook an investigation to evaluate cervical veins (facial, external jugular) as patch material after carotid endarterectomy. A device that stimulated both circumferential fixation by sutures and radial tension exerted on in vivo patches was constructed to measure burst strength of tissue. Mean bursting pressure for groin saphenous vein (n = 10) was 94.5 +/- 15.1 pounds per square inch (psi), 75.5 +/- 8.9 psi for ankle saphenous vein (n = 10), 83.3 +/- 14.5 psi for everted (double layer) cervical vein (n = 5) and 10 +/- 3.3 psi for single layer cervical vein (n = 5). No significant differences between saphenous vein at any level and everted (double layer) cervical vein, but all were significantly different from single layer cervical vein (p less than 0.05). From June 1987 through November 1989, 19 patients underwent 21 carotid endarterectomies complemented with adjunctive everted cervical vein patch angioplasty. Indications for surgery were asymptomatic stenosis (53%), transient ischemic attack (29%), and cerebrovascular accident with recovery (18%). All patients were studied after surgery with duplex scanning. Asymptomatic recurrent stenosis was observed in one patient. Transient hypoglossal nerve dysfunction occurred in one other patient. One postoperative death occurred as a result of massive aspiration. These results indicate that everted cervical vein is comparable to the saphenous vein in resistance to bursting and can yield similar results as patch material after carotid endarterectomy. Accordingly, saphenous vein can be spared and lower extremity incisions avoided.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Carotid Stent Fracture from Stylocarotid Syndrome

    PubMed Central

    Hooker, Jeffrey D; Joyner, David A; Farley, Edward P; Khan, Majid

    2016-01-01

    Eagle syndrome is a rare condition resulting from elongation of the temporal styloid process or calcification of its associated stylohyoid ligaments. Although usually presenting with pain or odynophagia, Eagle syndrome has been reported to cause a multitude of neurologic symptoms or vascular complications, some of which can be life-threatening. We present a case in which an endovascularly placed internal carotid artery stent in close proximity to a calcified stylohyoid ligament resulted in stent fracture with subsequent stent and vessel occlusion. We review and discuss the presentation, diagnosis, etiology, complications and treatment options of the syndrome. PMID:27761179

  2. Congenital Absence of the Internal Carotid Artery

    SciTech Connect

    Florio, Francesco; Balzano, Silverio; Nardella, Michele; Strizzi, Vincenzo; Cammisa, Mario; Bozzini, Vincenzo; Catapano, Giuseppe; D'Angelo, Vincenzo

    1999-01-15

    We report three cases of congenital absence of an internal carotid artery (ICA), diagnosed incidentally by digital subtraction angiography. The analysis of the cases is based on the classification of segmental ICA agenesis proposed by Lasjaunias and Berenstein. Usually the patients with this rare vascular anomaly are asymptomatic; some may have symptoms related to cerebrovascular insufficiency, compression by enlarged intracranial collateral vessels, or complications associated with cerebral aneurysms. Diagnosis of congenital absence of ICA is made by skull base computed tomography (CT) scan, CT and magnetic resonance angiography, and conventional or digital subtraction angiography.

  3. Concomitant Carotid and Coronary Artery Reconstruction

    PubMed Central

    Craver, Joseph M.; Murphy, Douglas A.; Jones, Ellis L.; Curling, Patrick E.; Bone, David K.; Smith, Robert B.; Perdue, Garland D.; Hatcher, Charles R.; Kandrach, Michael

    1982-01-01

    Data are presented on 68 patients who underwent concomitant carotid endarterectomy (CE) and coronary artery bypass surgery (CAB) at Emory University Hospital from January 1974 to February 1981. This group is then compared with a randomly selected, matched population without known carotid disease who underwent CAB alone. Asymptomatic bruit was the reason for investigation in 40 patients (59%); another 23 patients (34%) experienced transient cerebral ischemic attacks (TIAs); and five patients (7%) had TIA and prior stroke. Carotid stenoses (>75% luminal narrowing) were demonstrated as follows: isolated left, 24 patients; isolated right, 27 patients; and bilateral lesions, 16 patients. One patient had innominate artery stenosis. Associated total occlusion of one or both vertebral arteries was demonstrated in six patients. Ninety-seven per cent of patients had disabling angina pectoris prior to operation; the angina was unstable in 57%, 15% had congestive heart failure, and 54% had had at least one prior myocardial infarction (MI). Single-vessel coronary disease was present in 12.5% of patients, double in 37.5%, triple in 41.1%, and left main stenosis in 9%; 43% of patients had abnormal ventricular contractility. CE was performed on 67 patients (36 left and 31 right); aortocarotid bypass was performed on one. The CE procedures were performed immediately prior to the sternotomy for CAB under the same anesthesia. CAB consisted of single bypass in eight patients (11.8%); double in 16 patients (23.5%); triple in 22 patients (32.4%); and quadruple or more in 22 patients (32.4%) (mean = 2.9 grafts per patient). There was no hospital mortality. Perioperative MI occurred in 2.0% and stroke with residual deficit in 1.3%. Cumulative survival is 98.5% at two years. Sixty-three patients (92%) reported improvement or elimination of anginal symptoms after operation. Rehospitalization for stroke was necessary in 3.7% patients. Postoperative activity levels are; self-care only, 3

  4. Clinical Carotid Measurements: Present and Future State

    PubMed Central

    Strandness, D.E.

    1982-01-01

    The most satisfactory methods of evaluating the carotid artery have included Doppler imaging and ultrasonic duplex scanning. It is now recognized that these techniques are most accurate when used in combination with spectral analysis to more objectively determine the flow patterns present across this important bifurcation. In the centers where there is the most experience in their use, the sensitivity of the methods approach 90% and are most accurate for detecting high-grade stenoses (greater than 50% diameter reduction). The most promising future applications include the use of computerized pattern recognition techniques to quantitatively separate patients with varying degrees of disease. PMID:15226956

  5. Recommendations for Carotid Stenting in Korea

    PubMed Central

    Chang, Hyuk Won; Suh, Sang-il; Jeong, Hae Woong; Suh, Dae Chul

    2015-01-01

    Carotid artery angioplasty with stenting (CAS) is being performed in many hospitals in Korea. Most of the guidelines which are being used are similar, but the practical aspects such as techniques are different between hospitals. For example, usage of various protective devices, the oral antiplatelet regimen prior to procedure and placing of temporary pacemaker to prevent bradycardia are different between hospitals. In this article, we summarize and propose the guidelines for CAS which is currently being accepted in Korea. These guidelines may be helpful in providing protocol to neurointerventionalist who perform CAS and to standardize the process including reporting of CAS in the future comparative trials in Korea. PMID:25763292

  6. Management of Extracranial Carotid Artery Disease

    PubMed Central

    Ooi, Yinn Cher

    2015-01-01

    Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common non-traumatic cause among adults <45 years of age. The aim of this paper is to provide comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management and interventional management. PMID:25439328

  7. Association between the Gensini Score and Carotid Artery Stenosis

    PubMed Central

    Fidan, Serdar; Tabakçı, Mehmet Mustafa; Toprak, Cuneyt; Alizade, Elnur; Acar, Emrah; Bayam, Emrah; Tellice, Muhammet; Naser, Abdurrahman; Kargın, Ramazan

    2016-01-01

    Background and Objectives The aim of this study was to evaluate the association between the extent of coronary artery disease assessed by the Gensini score and/or the SYNTAX score and the significant carotid stenosis in patients undergoing coronary artery bypass grafting (CABG). Subjects and Methods A total of 225 patients who had carotid doppler ultrasonography prior to CABG were included retrospectively. Significant coronary artery disease was assumed as a lumen diameter stenosis of ≥50% in any of the major epicardial coronary arteries. The severity of carotid stenosis was determined by B-mode and duplex ultrasonography. Clinically significant carotid stenosis was defined as peak systolic velocity greater than 125 cm/s. Results The mean value of SYNTAX score and Gensini score was highest in patients allocated to significant carotid stenosis (22.98±7.32, p<0.001 and 77.40±32.35, p<0.001, respectively). The other risk factors for significant carotid stenosis were found to be male gender (p=0.029), carotid bruit (p<0.001), diabetes (p=0.021), left main disease (p=0.002), 3-vessel disease (p=0.008), chronic total coronary occlusion (p=0.001), and coronary artery calcification (p=0.001) in univariate analysis. However, only the Gensini score (odds ratio[OR]=1.030, p=0.004), carotid bruit (OR=0.068, p<0.001), and male gender (OR=0.190, p=0.003) were the independent predictors. The Gensini score cut off value predicting significant carotid stenosis was 50.5 with 77% sensitivity (p<0.001). Conclusion The Gensini score may be used to identify patients at high risk for significant carotid stenosis prior to CABG. PMID:27721854

  8. The Urotensin II System and Carotid Atherosclerosis: A Role in Vascular Calcification

    PubMed Central

    Albanese, Isabella; Daskalopoulou, Stella S.; Yu, Bin; You, Zhipeng; Genest, Jacques; Alsheikh-Ali, Alawi; Schwertani, Adel G.

    2016-01-01

    Background and Aims: The aims of the present study were to determine the expression of urotensin II (UII), urotensin-II related peptide (URP), and their receptor (UT) in stable and unstable carotid atherosclerosis, and determine the effects of UII on human aortic smooth muscle cell (SMCs) calcification. Methods and Results: We examined UII, URP, and UT protein expression in 88 carotid endarterectomy specimens using immunohistochemistry. Expression of UII, URP, and UT was more evident in unstable compared to stable plaques (P < 0.05). Multivariate Spearman correlation analyses revealed significant positive correlations between UII, URP and UT overall staining and presence of calcification, severity of stenosis and inflammation (P < 0.05). Subjects undergoing carotid endarterectomy had significantly higher plasma UII levels, as assessed by ELISA, when compared with normolipidemic healthy control subjects (P < 0.05). Incubation of human aortic SMCs cultured in phosphate media with varying concentrations of UII resulted in a significant increase in calcium deposition and alkaline phosphatase activity. UII also significantly increased β-catenin translocation and expression of ALPL, BMP2, ON, and SOX9 (P < 0.05). Incubation of cells with phosphate medium alone increased the expression of the pre-UT and mature UT (P < 0.01), and addition of UII had a synergistic effect on pre-UT protein expression (P < 0.001) compared to phosphate medium alone. Conclusions: Upregulation of UII, URP, and UT in unstable carotid endarterectomy plaques and plasma, and the stimulatory effect of UII on vascular smooth muscle cell calcification suggest that the UII system may play a role in the pathogenesis of vascular calcification and stability of atherosclerosis. PMID:27375483

  9. Technical advance: liposomal alendronate depletes monocytes and macrophages in the nonhuman primate model of human disease.

    PubMed

    Burwitz, Benjamin J; Reed, Jason S; Hammond, Katherine B; Ohme, Merete A; Planer, Shannon L; Legasse, Alfred W; Ericsen, Adam J; Richter, Yoram; Golomb, Gershon; Sacha, Jonah B

    2014-09-01

    Nonhuman primates are critical animal models for the study of human disorders and disease and offer a platform to assess the role of immune cells in pathogenesis via depletion of specific cellular subsets. However, this model is currently hindered by the lack of reagents that safely and specifically ablate myeloid cells of the monocyte/macrophage Lin. Given the central importance of macrophages in homeostasis and host immunity, development of a macrophage-depletion technique in nonhuman primates would open new avenues of research. Here, using LA at i.v. doses as low as 0.1 mg/kg, we show a >50% transient depletion of circulating monocytes and tissue-resident macrophages in RMs by an 11-color flow cytometric analysis. Diminution of monocytes was followed rapidly by emigration of monocytes from the bone marrow, leading to a rebound of monocytes to baseline levels. Importantly, LA was well-tolerated, as no adverse effects or changes in gross organ function were observed during depletion. These results advance the ex vivo study of myeloid cells by flow cytometry and pave the way for in vivo studies of monocyte/macrophage biology in nonhuman primate models of human disease. PMID:24823811

  10. DNA technological progress toward advanced diagnostic tools to support human hookworm control.

    PubMed

    Gasser, R B; Cantacessi, C; Loukas, A

    2008-01-01

    Blood-feeding hookworms are parasitic nematodes of major human health importance. Currently, it is estimated that 740 million people are infected worldwide, and more than 80 million of them are severely affected clinically by hookworm disease. In spite of the health problems caused and the advances toward the development of vaccines against some hookworms, limited attention has been paid to the need for improved, practical methods of diagnosis. Accurate diagnosis and genetic characterization of hookworms is central to their effective control. While traditional diagnostic methods have considerable limitations, there has been some progress toward the development of molecular-diagnostic tools. The present article provides a brief background on hookworm disease of humans, reviews the main methods that have been used for diagnosis and describes progress in establishing polymerase chain reaction (PCR)-based methods for the specific diagnosis of hookworm infection and the genetic characterisation of the causative agents. This progress provides a foundation for the rapid development of practical, highly sensitive and specific diagnostic and analytical tools to be used in improved hookworm prevention and control programmes.

  11. Technical Advance: Liposomal alendronate depletes monocytes and macrophages in the nonhuman primate model of human disease

    PubMed Central

    Burwitz, Benjamin J.; Reed, Jason S.; Hammond, Katherine B.; Ohme, Merete A.; Planer, Shannon L.; Legasse, Alfred W.; Ericsen, Adam J.; Richter, Yoram; Golomb, Gershon; Sacha, Jonah B.

    2014-01-01

    Nonhuman primates are critical animal models for the study of human disorders and disease and offer a platform to assess the role of immune cells in pathogenesis via depletion of specific cellular subsets. However, this model is currently hindered by the lack of reagents that safely and specifically ablate myeloid cells of the monocyte/macrophage Lin. Given the central importance of macrophages in homeostasis and host immunity, development of a macrophage-depletion technique in nonhuman primates would open new avenues of research. Here, using LA at i.v. doses as low as 0.1 mg/kg, we show a >50% transient depletion of circulating monocytes and tissue-resident macrophages in RMs by an 11-color flow cytometric analysis. Diminution of monocytes was followed rapidly by emigration of monocytes from the bone marrow, leading to a rebound of monocytes to baseline levels. Importantly, LA was well-tolerated, as no adverse effects or changes in gross organ function were observed during depletion. These results advance the ex vivo study of myeloid cells by flow cytometry and pave the way for in vivo studies of monocyte/macrophage biology in nonhuman primate models of human disease. PMID:24823811

  12. Classification of human colonic tissues using FTIR spectra and advanced statistical techniques

    NASA Astrophysics Data System (ADS)

    Zwielly, A.; Argov, S.; Salman, A.; Bogomolny, E.; Mordechai, S.

    2010-04-01

    One of the major public health hazards is colon cancer. There is a great necessity to develop new methods for early detection of cancer. If colon cancer is detected and treated early, cure rate of more than 90% can be achieved. In this study we used FTIR microscopy (MSP), which has shown a good potential in the last 20 years in the fields of medical diagnostic and early detection of abnormal tissues. Large database of FTIR microscopic spectra was acquired from 230 human colonic biopsies. Five different subgroups were included in our database, normal and cancer tissues as well as three stages of benign colonic polyps, namely, mild, moderate and severe polyps which are precursors of carcinoma. In this study we applied advanced mathematical and statistical techniques including principal component analysis (PCA) and linear discriminant analysis (LDA), on human colonic FTIR spectra in order to differentiate among the mentioned subgroups' tissues. Good classification accuracy between normal, polyps and cancer groups was achieved with approximately 85% success rate. Our results showed that there is a great potential of developing FTIR-micro spectroscopy as a simple, reagent-free viable tool for early detection of colon cancer in particular the early stages of premalignancy among the benign colonic polyps.

  13. Successful Endovascular Treatment of a Left Common Carotid Artery Aneurysm Following Failed Surgery of a Right Common Carotid Artery Aneurysm

    SciTech Connect

    Cil, Barbaros E. Ucar, Ibrahim; Ozsoy, Fatma; Arat, Anil; Yorgancioglu, Cem; Boeke, Erkmen

    2005-04-15

    Aneurysm of the common carotid artery is a rare and serious disease requiring prompt treatment in order to avoid neurologic complications. A 39-year-old man presented with voice impairment and a pulsatile mass at the right side of his neck and was found by color Doppler examination to have bilateral common carotid artery aneurysms of unknown origin. The right-sided large aneurysm was treated with placement of an 8 mm interposition Gore-Tex graft between the right common and internal carotid arteries. The surgical graft thrombosed 7 days after the surgery but the left-sided aneurysm was successfully treated by a Jostent peripheral stent-graft. Color Doppler examination showed a patent stent and no filling of the aneurysm on his first and sixth-month follow-up. Bilateral common carotid artery aneurysm is an exceptionally unusual condition and endovascular treatment of carotid artery aneurysms with covered stents may become an effective treatment alternative for these lesions.

  14. Recent advances in determining protein and amino acid requirements in humans.

    PubMed

    Elango, Rajavel; Ball, Ronald O; Pencharz, Paul B

    2012-08-01

    During the past 25 years a significant amount of research has been conducted to determine amino acid requirements in humans. This is primarily due to advancements in the application of stable isotopes to examine amino acid requirements. The indicator amino acid oxidation (IAAO) method has emerged as a robust and minimally invasive technique to identify requirements. The IAAO method is based on the concept that when one indispensable dietary amino acid (IDAA) is deficient for protein synthesis, then the excess of all other IDAA, including the indicator amino acid, will be oxidized. With increasing intakes of the limiting amino acid, IAAO will decrease, reflecting increasing incorporation into protein. Once the requirement for the limiting amino acid is met there will be no further change in the indicator oxidation. The IAAO method has been systematically applied to determine most IDAA requirements in adults. The estimates are comparable to the values obtained using the more elaborate 24h-indicator amino acid oxidation and balance (24h-IAAO/IAAB) model. Due to its non-invasive nature the IAAO method has also been used to determine requirements for amino acids in neonates, children and in disease. The IAAO model has recently been applied to determine total protein requirements in humans. The IAAO method is rapid, reliable and has been used to determine amino acid requirements in different species, across the life cycle and in disease. The recent application of IAAO to determine protein requirements in humans is novel and has significant implications for dietary protein intake recommendations globally.

  15. Detection of advanced glycation end products (AGEs) on human skin by in vivo confocal Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Martin, A. A.; Pereira, L.; Ali, S. M.; Pizzol, C. D.; Tellez, C. A.; Favero, P. P.; Santos, L.; da Silva, V. V.; Praes, C. E. O.

    2016-03-01

    The aging process involves the reduction in the production of the major components of skin tissue. During intrinsic aging and photoaging processes, in dermis of human skin, fibroblasts become senescent and have decreased activity, which produce low levels of collagen. Moreover, there is accumulation of advanced glycation end products (AGEs). AGEs have incidence in the progression of age-related diseases, principally in diabetes mellitus and in Alzheimer's diseases. AGEs causes intracellular damage and/or apoptosis leading to an increase of the free radicals, generating a crosslink with skin proteins and oxidative stress. The aim of this study is to detect AGEs markers on human skin by in vivo Confocal Raman spectroscopy. Spectra were obtained by using a Rivers Diagnostic System, 785 nm laser excitation and a CCD detector from the skin surface down to 120 μm depth. We analyzed the confocal Raman spectra of the skin dermis of 30 women volunteers divided into 3 groups: 10 volunteers with diabetes mellitus type II, 65-80 years old (DEW); 10 young healthy women, 20-33 years old (HYW); and 10 elderly healthy women, 65-80 years old (HEW). Pentosidine and glucosepane were the principally identified AGEs in the hydroxyproline and proline Raman spectral region (1000-800 cm-1), in the 1.260-1.320 cm-1 region assignable to alpha-helical amide III modes, and in the Amide I region. Pentosidine and glucosepane calculated vibrational spectra were performed through Density Functional Theory using the B3LYP functional with 3-21G basis set. Difference between the Raman spectra of diabetic elderly women and healthy young women, and between healthy elderly women and healthy young women were also obtained with the purpose of identifying AGEs Raman bands markers. AGEs peaks and collagen changes have been identified and used to quantify the glycation process in human skin.

  16. Next Generation Respiratory Viral Vaccine System: Advanced and Emerging Bioengineered Human Lung Epithelia Model (HLEM) Organoid Technology

    NASA Technical Reports Server (NTRS)

    Goodwin, Thomas J.; Schneider, Sandra L.; MacIntosh, Victor; Gibbons, Thomas F.

    2010-01-01

    Acute respiratory infections, including pneumonia and influenza, are the S t" leading cause of United States and worldwide deaths. Newly emerging pathogens signaled the need for an advanced generation of vaccine technology.. Human bronchial-tracheal epithelial tissue was bioengineered to detect, identify, host and study the pathogenesis of acute respiratory viral disease. The 3-dimensional (3D) human lung epithelio-mesechymal tissue-like assemblies (HLEM TLAs) share characteristics with human respiratory epithelium: tight junctions, desmosomes, microvilli, functional markers villin, keratins and production of tissue mucin. Respiratory Syntial Virus (RSV) studies demonstrate viral growth kinetics and membrane bound glycoproteins up to day 20 post infection in the human lung-orgainoid infected cell system. Peak replication of RSV occurred on day 10 at 7 log10 particles forming units per ml/day. HLEM is an advanced virus vaccine model and biosentinel system for emergent viral infectious diseases to support DoD global surveillance and military readiness.

  17. Glaucoma Management in Carotid Cavernous Fistula

    PubMed Central

    Calafiore, Silvia; Perdicchi, Andrea; Scuderi, Gianluca; Contestabile, Maria Teresa; Abdolrahimzadeh, Solmaz; Recupero, Santi Maria

    2016-01-01

    Carotid cavernous fistulas (CCF) are vascular communications between the carotid artery and the cavernous sinus. Ophthalmologists are called to diagnose and manage the condition in cases that present with ocular features. A 73-year-old female was referred to our glaucoma center clinic. Eight years before, she had started receiving medication for glaucoma and had undergone laser iridotomy, but a satisfactory management of intraocular pressure (IOP) had not been achieved. The patient was complaining of intermittent diplopia, bilateral proptosis, and conjunctival chemosis over the past 6 months. Best-corrected visual acuity in the right (OD) and left eye (OS) was 9/10 and 10/10, respectively. Visual field testing showed slight paracentral field defects mostly in OS. IOP was 20 mm Hg in OD and 34 mm Hg in OS. We referred the patient to neuroradiology, and MRI angiography revealed a CCF with angiographic classification of Cognard grade 2. Closure of the CCF by transarterial embolization was performed in the neuroradiology department. One week following the procedure, the clinical signs of diplopia, proptosis, and conjunctival chemosis had greatly improved, and IOP was reduced to 12 mm Hg OD and 19 mm Hg in OS. Glaucoma treatment was maintained with topical brimatoprost, brinzolamide, and timolol. Owing to the risk of vision loss associated with vascular stasis, retinal ischemia, and high IOP, ophthalmologists must be aware of the clinical features of CCF and should request appropriate imaging studies such as MRI angiography in order to confirm the diagnosis and plan multidisciplinary treatment. PMID:27462258

  18. Stenting of Extracranial Carotid Artery Stenosis

    PubMed Central

    Koshimae, N.; Morimoto, T.; Nagata, K.

    2003-01-01

    Summary The purpose of this study is to evaluate our cases of cervical internal carotid artery stenosis for safty stenting. We investigate the preoperative internal carotid artery stenosis using by integrated backscatter (IBS) method of ultra sonography, comparing with the thirty five surgical specimens as to their nature, histological structure, thickness of fibrous cap. We choose the protection method according to plaque structure, and placed Easy-Wall stent or Smart stent after prePTA. We added post PTA according to the extent of expansion and IVUS findings. Calibrated IBS = IBS value (ROI) /intinal IBS value of ‘bleeding’, ‘lipiď, ‘thrombus’, fiber, ‘hyalinization’ were -27.5, -22.5, -15.2, -11.1, +2.1. That of the thin fibrous cap were -10.9*, that of thic fibrous cap were -2.4 (*p < 0.001). There was a good coleration between the extent of expansion and expected histological findings. All conplications were two cases of small cerebral infarction and a case of bleeding from the complicated lung cancer. The protection at prePTA lead to no complications in case of acute cerebral infarctions. It is very important to check the histological specimen carefully for safty stenting. PMID:20591243

  19. Glaucoma Management in Carotid Cavernous Fistula.

    PubMed

    Calafiore, Silvia; Perdicchi, Andrea; Scuderi, Gianluca; Contestabile, Maria Teresa; Abdolrahimzadeh, Solmaz; Recupero, Santi Maria

    2016-01-01

    Carotid cavernous fistulas (CCF) are vascular communications between the carotid artery and the cavernous sinus. Ophthalmologists are called to diagnose and manage the condition in cases that present with ocular features. A 73-year-old female was referred to our glaucoma center clinic. Eight years before, she had started receiving medication for glaucoma and had undergone laser iridotomy, but a satisfactory management of intraocular pressure (IOP) had not been achieved. The patient was complaining of intermittent diplopia, bilateral proptosis, and conjunctival chemosis over the past 6 months. Best-corrected visual acuity in the right (OD) and left eye (OS) was 9/10 and 10/10, respectively. Visual field testing showed slight paracentral field defects mostly in OS. IOP was 20 mm Hg in OD and 34 mm Hg in OS. We referred the patient to neuroradiology, and MRI angiography revealed a CCF with angiographic classification of Cognard grade 2. Closure of the CCF by transarterial embolization was performed in the neuroradiology department. One week following the procedure, the clinical signs of diplopia, proptosis, and conjunctival chemosis had greatly improved, and IOP was reduced to 12 mm Hg OD and 19 mm Hg in OS. Glaucoma treatment was maintained with topical brimatoprost, brinzolamide, and timolol. Owing to the risk of vision loss associated with vascular stasis, retinal ischemia, and high IOP, ophthalmologists must be aware of the clinical features of CCF and should request appropriate imaging studies such as MRI angiography in order to confirm the diagnosis and plan multidisciplinary treatment. PMID:27462258

  20. Hypothermia during Carotid Endarterectomy: A Safety Study

    PubMed Central

    Candela, Serena; Dito, Raffaele; Casolla, Barbara; Silvestri, Emanuele; Sette, Giuliano; Filippi, Federico; Taurino, Maurizio; Brancadoro, Domitilla; Orzi, Francesco

    2016-01-01

    Background CEA is associated with peri-operative risk of brain ischemia, due both to emboli production caused by manipulation of the plaque and to potentially noxious reduction of cerebral blood flow by carotid clamping. Mild hypothermia (34–35°C) is probably the most effective approach to protect brain from ischemic insult. It is therefore a substantial hypothesis that hypothermia lowers the risk of ischemic brain damage potentially associated with CEA. Purpose of the study is to test whether systemic endovascular cooling to a target of 34.5–35°C, initiated before and maintained during CEA, is feasible and safe. Methods The study was carried out in 7 consecutive patients referred to the Vascular Surgery Unit and judged eligible for CEA. Cooling was initiated 60–90 min before CEA, by endovascular approach (Zoll system). The target temperature was maintained during CEA, followed by passive, controlled rewarming (0.4°C/h). The whole procedure was carried out under anesthesia. Results All the patients enrolled had no adverse events. Two patients exhibited a transient bradycardia (heart rate 30 beats/min). There were no significant differences in the clinical status, laboratory and physiological data measured before and after CEA. Conclusions Systemic cooling to 34.5–35.0°C, initiated before and maintained during carotid clamping, is feasible and safe. Trial Registration ClinicalTrials.gov NCT02629653 PMID:27058874

  1. Noninvasive Assessment of Carotid Artery Disease

    PubMed Central

    Bandyk, Dennis F.; Thiele, Brain L.

    1983-01-01

    Noninvasive methods of detecting carotid disease were developed to avoid the morbidity and occasional mortality associated with cerebral angiography. The tests developed are of the following two types: direct, which uses imaging or the detection of flow disturbances to identify disease at the bifurcation, and indirect, which infers the presence of bifurcation disease by detecting changes at a remote site. The initial goal of only detecting disease has now been broadened, with this technology being used to address important clinical and epidemiologic questions such as the natural history of carotid bifurcation disease. The recognition of these important contributions has been compounded, however, by the large number of tests that are available, producing the problem of deciding which test or tests should be used for a particular patient. The use of multiple tests avoids the deficiencies of single tests but compounds medical costs. For a cost-effective single form of testing for all circumstances, duplex scanning methods offer the greatest possibility of detecting all degrees of disease. Images PMID:6649597

  2. Medical treatment in carotid artery intervention.

    PubMed

    Kolkert, J L; Meerwaldt, R; Lefrandt, J D; Geelkerken, R H; Zeebregts, C J

    2011-12-01

    Medical treatment has a pivotal role in the treatment of patients with occlusive carotid artery disease. Large trials have provided the justification for operative treatment besides medical treatment in patients with recent significant carotid artery stenosis two decades ago. Since then, medical therapy has evolved tremendously. Next to aspirin, antiplatelet regimens acting on a different level in the modulation of platelet aggregation have made their entry. Moreover, statin therapy has been introduced. These changes among others in secondary stroke prevention, along with better understanding in life-style adjustments and perioperative medical management, have led to a decrease in stroke recurrence. Secondary prevention is therefore now the most important pillar of medical therapy. It consists of antiplatelet therapy, statins and blood pressure lowering agents in all patients. Small adjustments are recommended for those patients referred for invasive treatment. Moreover, long-term medical treatment is imperative. In this article, we summarize current evidence in literature regarding medical management in patients with previous stroke or TIA. PMID:22051989

  3. Radiation therapy of carotid body tumors

    SciTech Connect

    Valdagni, R.; Amichetti, M. )

    1990-02-01

    Chemodectomas of carotid artery bifurcation are generally managed with surgery, irradiation being reserved for inoperable, bulky, and recurrent tumors. Probably due to this pretreatment selection of patients, chemodectomas are anedoctally considered radioresistant tumors, although this concept is not supported by the recent literature. From 1968 to 1987, 13 carotid body tumors in seven patients were treated with irradiation as sole treatment (10 lesions) or as postoperative modality (three lesions). Familial occurrence and bilateral presentation were observed in 3 of 7 and in 6 of 7 patients, respectively. Total dose of irradiation was of 46-60 Gy (median 50 Gy, mean 52.25 Gy) with dose per fraction of 1.8-2.5 Gy. Local control (subjective or objective) was obtained in all the patients. Clinical results following World Health Organization (WHO) criteria were: 3 of 13 complete response, 7 of 13 partial response and 3 of 13 no change. Follow-up range is 1-19 years. Acute side effects were minimal and mid- or long-term toxicity was absent.32 references.

  4. Medical treatment in carotid artery intervention.

    PubMed

    Kolkert, J L; Meerwaldt, R; Lefrandt, J D; Geelkerken, R H; Zeebregts, C J

    2011-12-01

    Medical treatment has a pivotal role in the treatment of patients with occlusive carotid artery disease. Large trials have provided the justification for operative treatment besides medical treatment in patients with recent significant carotid artery stenosis two decades ago. Since then, medical therapy has evolved tremendously. Next to aspirin, antiplatelet regimens acting on a different level in the modulation of platelet aggregation have made their entry. Moreover, statin therapy has been introduced. These changes among others in secondary stroke prevention, along with better understanding in life-style adjustments and perioperative medical management, have led to a decrease in stroke recurrence. Secondary prevention is therefore now the most important pillar of medical therapy. It consists of antiplatelet therapy, statins and blood pressure lowering agents in all patients. Small adjustments are recommended for those patients referred for invasive treatment. Moreover, long-term medical treatment is imperative. In this article, we summarize current evidence in literature regarding medical management in patients with previous stroke or TIA.

  5. Should patients with asymptomatic significant carotid stenosis undergo simultaneous carotid and cardiac surgery?

    PubMed Central

    Ogutu, Peter; Werner, Raphael; Oertel, Frank; Beyer, Michael

    2014-01-01

    A best evidence topic in cardiovascular surgery was written according to a structured protocol. The question addressed was whether patients with severe asymptomatic carotid and coronary artery diseases should undergo simultaneous carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG). A total of 624 papers were found using the reported search, of which 20 represent the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study results of these papers are tabulated. Previous cohort studies showed mixed results, while advocating for the necessity of a randomized controlled trial (RCT). A recent RCT showed that patients undergoing prophylactic or simultaneous CEA + CABG had lower rates of stroke (0%) compared with delayed CEA 1–3 months after CABG (7.7%), without significant perioperative mortality difference. This study included patients with unilateral severe (>70%) asymptomatic carotid stenosis requiring CABG. An earlier partly randomized trial also showed better outcomes for patients undergoing simultaneous procedures (P = 0.045). Interestingly, systematic reviews previously failed to show compelling evidence supporting prophylactic CEA. This could be partly due to the fact that these reviews collectively analyse different cohort qualities. Neurological studies have, however, shown reduced cognitive and phonetic quality and function in patients with unilateral and bilateral asymptomatic carotid artery stenosis. Twenty-one RCTs comparing lone carotid artery stenting (CAS) and CEA informed the American Heart Association guidelines, which declared CAS comparable with CEA for symptomatic and asymptomatic carotid stenosis (CS). However, the risk of death/stroke for CAS alone is double that for CEA alone in the acute phase following onset of symptoms, while CEA alone is associated with a doubled risk of myocardial infarction. There is

  6. Contralateral acoustic stimulation induces a phase advance in evoked otoacoustic emissions in humans.

    PubMed

    Giraud, A L; Perrin, E; Chéry-Croze, S; Chays, A; Collet, L

    1996-05-01

    In 28 normal-hearing human subjects, the medial olivocochlear efferent system was activated by contralateral acoustic stimulation which is able to mimic the inhibitory effects of electrical stimulation of the crossed olivocochlear bundle. A first experiment on 16 subjects demonstrated that a contralateral white noise of 35 dB SL was able to induce temporal changes on transiently evoked otoacoustic emissions in response to clicks of 63 dB SPL. These temporal changes consisted of an advance of click-evoked otoacoustic signals in 87% of cases and is referred to as phase-shift effect. The phase advance, quantified using two signal processing methods in both time and frequency domains, was found to be mainly associated with lower frequencies, with a maximal effect at 1.5 kHz and minimal effects around 3.5 and 4 kHz. In a second experiment, carried out on 12 subjects, a negative relationship was found to exist between the ipsilateral stimulation level (level of clicks ranging from 57 to 69 dB SPL) and the phase-shift effect (PSE). Specifically in the range of levels tested (25-45 dB SL), a linear relationship presenting no obvious saturation effect was observed between the contralateral level and the PSE. The PSE was examined in 6 additional subjects exhibiting pathological symptoms; 2 of 3 individuals, who had no contralateral stapedial reflexes unilaterally, showed the PSE whereas this response was reduced or absent in 3 other subjects in the ear with severed efferents associated with a vestibular neurotomy. The integrity of olivocochlear efferents was, therefore, necessary to obtain a full effect, but the absence of stapedial reflex did not prevent the effect from occurring. PMID:8789811

  7. Defining Advancement Career Paths and Succession Plans: Critical Human Capital Retention Strategies for High-Performing Advancement Divisions

    ERIC Educational Resources Information Center

    Croteau, Jon Derek; Wolk, Holly Gordon

    2010-01-01

    There are many factors that can influence whether a highly talented staff member will build a career within an institution or use it as a stepping stone. This article defines and explores the notions of developing career paths and succession planning and why they are critical human capital investment strategies in retaining the highest performers…

  8. [Simultaneous carotid and vertebral revascularization in the aged].

    PubMed

    Illuminati, G; Caliò, F G; Bertagni, A; Piermattei, A; Vietri, F; Martinelli, V

    1997-09-01

    Five patients of a mean age of 76, have been submitted to combined vertebral and carotid artery revascularization for a severe vertebro-basilar insufficiency. Vertebral artery revascularization consisted of a transposition to the common carotid artery in one case and of a carotid-distal vertebral artery saphenous bypass graft. The associated carotid artery revascularization consisted of a carotid endarterectomy with patch in 4 cases and without patch in one case. There were no postoperative mortality and no postoperative stroke. Postoperative morbidity included a transitory revascularization syndrome, a myocardial ischemia and a Horner's syndrome. Complete relief of vertebrobasilar symptoms was obtained in 4 patients whereas in one patient only a mild positional vertigo persisted. All vascular reconstructions have been assessed with postoperative arteriography and duplex-scan every six months. At 11 months mean follow-up, all revascularizations are patent. Combined carotid and vertebral artery surgery is effective in well selected cases, and it does not enhance the risk of the two operations performed separately. It also eliminate the possibility of failure of isolated carotid revascularization for vertebrobasilar symptoms.

  9. Carotid Stenting vs Endarterectomy: New Results in Perspective

    PubMed Central

    Perkins, William J.; Lanzino, Guiseppe; Brott, Thomas G.

    2010-01-01

    Carotid artery stenosis is a major risk factor for stroke, and treatments for this condition to decrease the risk of stroke include medical therapy, carotid endarterectomy (CEA), and, more recently, carotid angioplasty and stenting (CAS). Randomized controlled trials comparing the efficacy of CEA vs medical therapy showed a clear benefit for CEA in patients with symptomatic carotid artery stenosis of greater than 70% and a lesser benefit in patients with 50% to 69% stenosis. Treatments have evolved in the ensuing 20 years, and a new method, CAS, has emerged as a possible alternative to CEA. In early results, CAS proved feasible but did not compare favorably with CEA. Later and larger-scale studies comparing CAS to CEA failed to reach conclusions regarding a clear neurologic outcome advantage of one method over the other. This subject was of sufficient interest that 2 larger-scale randomized controlled trials comparing CAS and CEA, the Carotid Revascularization Endarterectomy vs Stenting Trial and the International Carotid Stenting Study, were undertaken to further explore this issue. This brief review places the new data arising from these studies in the context of prior efforts to address the problem of carotid artery stenosis and explores further opportunities for improvement and patient recommendations in light of these new findings. PMID:21123637

  10. Life expectancy and late stroke following carotid endarterectomy.

    PubMed Central

    Bernstein, E F; Humber, P B; Collins, G M; Dilley, R B; Devin, J B; Stuart, S H

    1983-01-01

    A review of the UCSD experience with 456 consecutive carotid endarterectomy procedures confirms the acceptably low operative mortality and morbidity associated with this operation. Immediate complications were not different when routine or selective shunting was performed, but the patients with a low internal carotid artery back pressure had higher operative complication rates. The coexistence of atherosclerosis in other parts of the body severe-enough to warrant surgery for them was not associated with either higher early or late carotid surgery complication rates. Following both coronary bypass and carotid procedures, the late mortality was decreased, and the late incidence of stroke was particularly low in comparison to the remainder of the patient group. Late follow-up emphasized the high continuing attrition rate from all causes in these patients. Late strokes continued to occur, particularly in patients with prior strokes and severe preoperative bilateral carotid disease. The late course of patients with posterior circulation transient ischemic attacks treated by carotid endarterectomy was quite similar to that of patients treated for anterior circulation transient ischemia attacks (TIAs). Newer postoperative screening procedures may decrease the incidence of late postoperative stroke by identifying recurrent carotid stenosis while it is still in the asymptomatic stage. PMID:6602597

  11. Peripheral Chemoreceptors: Function and Plasticity of the Carotid Body

    PubMed Central

    Kumar, Prem; Prabhakar, Nanduri R.

    2014-01-01

    The discovery of the sensory nature of the carotid body dates back to the beginning of the 20th century. Following these seminal discoveries, research into carotid body mechanisms moved forward progressively through the 20th century, with many descriptions of the ultrastructure of the organ and stimulus-response measurements at the level of the whole organ. The later part of 20th century witnessed the first descriptions of the cellular responses and electrophysiology of isolated and cultured type I and type II cells, and there now exist a number of testable hypotheses of chemotransduction. The goal of this article is to provide a comprehensive review of current concepts on sensory transduction and transmission of the hypoxic stimulus at the carotid body with an emphasis on integrating cellular mechanisms with the whole organ responses and highlighting the gaps or discrepancies in our knowledge. It is increasingly evident that in addition to hypoxia, the carotid body responds to a wide variety of blood-borne stimuli, including reduced glucose and immune-related cytokines and we therefore also consider the evidence for a polymodal function of the carotid body and its implications. It is clear that the sensory function of the carotid body exhibits considerable plasticity in response to the chronic perturbations in environmental O2 that is associated with many physiological and pathological conditions. The mechanisms and consequences of carotid body plasticity in health and disease are discussed in the final sections of this article. PMID:23728973

  12. An absent ophthalmic artery or carotid siphon signal on transcranial Doppler confirms the presence of severe ipsilateral internal carotid artery disease.

    PubMed

    Wilterdink, J L; Feldmann, E; Bragoni, M; Brooks, J M; Benavides, J G

    1994-10-01

    Transcranial Doppler ultrasound provides a useful adjunct to extracranial ultrasound in the diagnosis of carotid bifurcation disease. Previous studies have shown that collateral flow patterns and diminished flow velocities in the ipsilateral middle cerebral artery correlate with hemodynamically significant carotid disease. In a series of 7,054 carotid duplex and transcranial Doppler examinations, 12.5% (95% confidence interval [CI]: 8.7, 16.4) of 287 ophthalmic arteries ipsilateral to an apparent carotid occlusion had no detectable flow signal, compared with 0.5% (95% CI: 0.3, 0.7) of 6,767 ophthalmic arteries ipsilateral to a non-occluded carotid artery (p < 0.001). Carotid siphon signals were not detectable in 24.4% (95% CI: 19.4, 29.4) of arteries ipsilateral to the carotid occlusion, versus 1.0% (95% CI: 0.8, 1.3) ipsilateral to nonoccluded carotid arteries (p < 0.001). A significant number of absent ophthalmic artery and carotid siphon signals (5.7 and 8.7%, respectively) were also found in patients with 80 to 99% extracranial carotid stenosis. A subset of 216 studies with angiographic correlation confirmed the high association of these transcranial Doppler findings with severe stenosis or occlusion of the internal carotid artery. Primary ophthalmological disease or siphon occlusion did not explain these findings. An absent ophthalmic artery or carotid siphon signal on transcranial Doppler examination is believed to represent a failure to detect slow flow distal to severe carotid bifurcation lesions. As a sign of ipsilateral carotid occlusion, the sensitivities of absent ophthalmic artery and carotid siphon signals are quite low (12.5 and 24.4%, respectively). The high specificities of 99.5 and 99.0%, however, make these findings useful in confirming the diagnosis of presumptive carotid occlusion by carotid duplex ultrasound.

  13. Heavy Snoring as a Cause of Carotid Artery Atherosclerosis

    PubMed Central

    Lee, Sharon A.; Amis, Terence C.; Byth, Karen; Larcos, George; Kairaitis, Kristina; Robinson, Tracey D.; Wheatley, John R.

    2008-01-01

    Study Objectives: Previous studies have suggested that snoring and obstructive sleep apnea hypopnea syndrome may be important risk factors for the development of carotid atherosclerosis and stroke. However, it is not clear if snoring per se is independently related to the risk of developing carotid atherosclerotic plaque. Design: Observational cohort study. Setting: Volunteer sample examined in a sleep laboratory. Participants: One hundred ten volunteers (snorers and nonsnorers with only mild, nonhypoxic obstructive sleep apnea hypopnea syndrome) underwent polysomnography with quantification of snoring, bilateral carotid and femoral artery ultrasound with quantification of atherosclerosis, and cardiovascular risk factor assessment. Subjects were categorized into 3 snoring groups: mild (0%–25% night snoring), moderate (> 25%–50% night snoring), and heavy (> 50% night snoring). Interventions: N/A. Measurements and Results: The prevalence of carotid atherosclerosis was 20% with mild snoring, 32% with moderate snoring, and 64% with heavy snoring (P < 0.04, Χ2). Logistic regression analysis was used to determine the independent effect of snoring on the prevalence of carotid and femoral atherosclerosis. After adjustment for age, sex, smoking history, and hypertension, heavy snoring was significantly associated with carotid atherosclerosis (odds ratio 10.5; 95% confidence interval 2.1–51.8; P = 0.004) but not with femoral atherosclerosis. Conclusions: Heavy snoring significantly increases the risk of carotid atherosclerosis, and the increase is independent of other risk factors, including measures of nocturnal hypoxia and obstructive sleep apnea severity. Considering the high prevalence of snoring in the community, these findings have substantial public health implications for the management of carotid atherosclerosis and the prevention of stroke. Citation: Lee SA; Amis TC; Byth K; Larcos G; Kairaitis K; RobinsonTD; Wheatley JR. Heavy snoring as a cause of carotid

  14. Hydrocortisone supresses inflammatory activity of metalloproteinase - 8 in carotid plaque

    PubMed Central

    Gabriel, Sthefano Atique; Antonangelo, Leila; Capelozzi, Vera Luiza; Beteli, Camila Baumann; de Camargo Júnior, Otacílio; de Aquino, José Luis Braga; Caffaro, Roberto Augusto

    2015-01-01

    Objective Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone. Methods The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after carotid endarterectomy. In carotid plaque, tissue levels of MMP-8 and MMP-9 were measured. Results Group 1 showed increased serum levels of MMP- 8 (994.28 pg/ml and 408.54 pg/ml, respectively; P=0.045) and MMP-9 (106,656.34 and 42,807.69 respectively; P=0.014) at 1 hour after carotid endarterectomy compared to the control group. Symptomatic patients in Group 1 exhibited lower tissue concentration of MMP-8 in comparison to the control group (143.89 pg/ml and 1317.36 respectively; P=0.003). There was a correlation between preoperative MMP-9 levels and tissue concentrations of MMP-8 (P=0.042) and MMP-9 (P=0.019) between symptomatic patients in the control group. Conclusion Hydrocortisone reduces the concentration of MMP- 8 in carotid plaque, especially in symptomatic patients. There was an association between systemic and tissue inflammation. PMID:26313719

  15. Mechanisms of carotid body chemoreflex dysfunction during heart failure

    PubMed Central

    Schultz, Harold D.; Marcus, Noah J.; Del Rio, Rodrigo

    2015-01-01

    Recent advances have drawn interest in the potential for carotid body (CB) ablation or desensitization as an effective strategy for clinical treatment and management of cardio-respiratory diseases including hypertension, heart failure, diabetes mellitus, metabolic syndrome, and renal failure. These disease states have in common sympathetic overactivity, which plays an important role in the development and progression of the disease and is often associated with breathing dysregulation, which in turn likely mediates or aggravates the autonomic imbalance. Evidence from both chronic heart failure (CHF) patients and animal models indicates that the CB chemoreflex is enhanced in CHF and contributes to the tonic elevation in sympathetic activity and the development of periodic breathing associated with the disease. Although this maladaptive change likely derives from altered function at all levels of the reflex arc, a tonic increase in afferent activity from CB glomus cells is likely to be a main driving force. This report will focus on our understanding of mechanisms that alter CB function in CHF and their potential translational impact on treatment of CHF. PMID:25398713

  16. Pathophysiology and Medical Treatment of Carotid Artery Stenosis

    PubMed Central

    Prasad, Kailash

    2015-01-01

    Stroke is the third leading cause of mortality. Approximately 80 to 85% strokes are ischemic due to carotid artery stenosis (CAS). The prevalence of significant CAS is 7% in women and 9% in men. Severe asymptomatic CAS varies from 0 to 3.1%. Prevalence of symptomatic CAS is high in patients with peripheral arterial disease. CAS is due to atherosclerosis, the major risk factors for which include dyslipidemia, hypertension, diabetes, obesity, cigarette smoking, advanced glycation end products (AGEs) and its receptors (RAGE, soluble RAGE [sRAGE]), lack of exercise and C-reactive protein (CRP). This article discusses the basic mechanism of atherosclerosis and the mechanisms by which these risk factors induce atherosclerosis. The role of AGEs and its receptors in the development and progression of CAS has been discussed in detail. Lifestyle changes and medical treatment of CAS such as lifestyle changes, lipid-lowering agents, antihypertensive agents, antidiabetic drugs, anti-AGE therapy, measures to elevate soluble receptors of AGE (sRAGE, esRAGE). CRP-lowering agents have been discussed in detail. The drugs especially lipid-lowering agents, and antihypertensive and antidiabetic drugs suppress, regress, and slow the progression of CAS. The possible role of lowering the levels of AGEs and raising the levels of sRAGE in the treatment of CAS has been proposed. Lifestyle changes besides medical treatment have been stressed. Lifestyle changes and medical treatment not only would slow the progression of CAS but would also regress the CAS. PMID:26417183

  17. Strain assessment in the carotid artery wall using ultrasound speckle tracking: validation in a sheep model.

    PubMed

    Larsson, Matilda; Verbrugghe, Peter; Smoljkić, Marija; Verhoeven, Jelle; Heyde, Brecht; Famaey, Nele; Herijgers, Paul; D'hooge, Jan

    2015-02-01

    The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound speckle tracking. The left carotid artery of five sheep was exposed and sonomicrometry crystals were sutured onto the artery wall to obtain reference strain. Ultrasound imaging was performed at baseline and stress, followed by strain estimation using an in-house speckle tracking algorithm tuned for vascular applications. The correlation between estimated and reference strain was r = 0.95 (p < 0.001) and r = 0.87 (p < 0.01) for longitudinal and circumferential strain, respectively. Moreover, acceptable limits of agreement were found in Bland-Altman analysis (longitudinally: -0.15 to 0.42%, circumferentially: -0.54 to 0.50%), which demonstrates the feasibility of estimating carotid artery strain using ultrasound speckle tracking. However, further studies are needed to test the algorithm on human in-vivo data and to investigate its potential to detect subclinical cardiovascular disease and characterize atherosclerotic plaques.

  18. Strain assessment in the carotid artery wall using ultrasound speckle tracking: validation in a sheep model

    NASA Astrophysics Data System (ADS)

    Larsson, Matilda; Verbrugghe, Peter; Smoljkić, Marija; Verhoeven, Jelle; Heyde, Brecht; Famaey, Nele; Herijgers, Paul; D'hooge, Jan

    2015-02-01

    The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound speckle tracking. The left carotid artery of five sheep was exposed and sonomicrometry crystals were sutured onto the artery wall to obtain reference strain. Ultrasound imaging was performed at baseline and stress, followed by strain estimation using an in-house speckle tracking algorithm tuned for vascular applications. The correlation between estimated and reference strain was r = 0.95 (p < 0.001) and r = 0.87 (p < 0.01) for longitudinal and circumferential strain, respectively. Moreover, acceptable limits of agreement were found in Bland-Altman analysis (longitudinally: -0.15 to 0.42%, circumferentially: -0.54 to 0.50%), which demonstrates the feasibility of estimating carotid artery strain using ultrasound speckle tracking. However, further studies are needed to test the algorithm on human in-vivo data and to investigate its potential to detect subclinical cardiovascular disease and characterize atherosclerotic plaques.

  19. Enhanced carotid body chemosensory activity and the cardiovascular alterations induced by intermittent hypoxia

    PubMed Central

    Iturriaga, Rodrigo; Andrade, David C.; Del Rio, Rodrigo

    2014-01-01

    The carotid body (CB) plays a main role in the maintenance of the oxygen homeostasis. The hypoxic stimulation of the CB increases the chemosensory discharge, which in turn elicits reflex sympathetic, cardiovascular, and ventilatory adjustments. An exacerbate carotid chemosensory activity has been associated with human sympathetic-mediated diseases such as hypertension, insulin resistance, heart failure, and obstructive sleep apnea (OSA). Indeed, the CB chemosensory discharge becomes tonically hypereactive in experimental models of OSA and heart failure. Chronic intermittent hypoxia (CIH), a main feature of OSA, enhances CB chemosensory baseline discharges in normoxia and in response to hypoxia, inducing sympathetic overactivity and hypertension. Oxidative stress, increased levels of ET-1, Angiotensin II and pro-inflammatory cytokines, along with a reduced production of NO in the CB, have been associated with the enhanced carotid chemosensory activity. In this review, we will discuss new evidence supporting a main role for the CB chemoreceptor in the autonomic and cardiorespiratory alterations induced by intermittent hypoxia, as well as the molecular mechanisms involved in the CB chemosensory potentiation. PMID:25520668

  20. External Carotid-Internal Jugular Fistula as a Late Complication After Carotid Endarterectomy: A Rare Case

    SciTech Connect

    Bakar, Bulent; Cekirge, Saruhan; Tekkok, Ismail Hakki

    2011-02-15

    A 66-year-old man presented with mild amnesia, progressive fatigue, ataxia, visual hallucinations, and debility. His past medical history included right-sided carotid endarterectomy performed elsewhere 6 years previously. Cranial magnetic resonance imaging showed left parieto-occipital arteriovenous malformation-like tortous vessels, venous congestion, and ischemic areas. Cerebral angiography showed right-sided compound external carotid artery-internal jugular vein (IJV) fistula, and distal occlusion of the right IJV. Transvenous embolization via contralateral IJV was performed, and the fistula, together with fistulous portion of the distal IJV, was sealed using coils. Two years later, patient is well with normal neurologic examination findings. The presence of an arteriovenous communication after vascular surgery is a serious complication with potential long-term effects and therefore should be diagnosed and treated as promptly as possible.

  1. Pathophysiology and management of reperfusion injury and hyperperfusion syndrome after carotid endarterectomy and carotid artery stenting.

    PubMed

    Farooq, Muhammad U; Goshgarian, Christopher; Min, Jiangyong; Gorelick, Philip B

    2016-01-01

    Cerebral hyperperfusion is a relatively rare syndrome with significant and potentially preventable clinical consequences. The pathophysiology of cerebral hyperperfusion syndrome (CHS) may involve dysregulation of the cerebral vascular system and hypertension, in the setting of increase in cerebral blood flow. The early recognition of CHS is important to prevent complications such as intracerebral hemorrhage. This review will focus on CHS following carotid endarterectomy and carotid artery stenting. We will discuss the typical clinical features of CHS, risk factors, pathophysiology, diagnostic modalities for detection, identification of patients at risk, and prevention and treatment. Although currently there are no specific guidelines for the management of CHS, identification of patients at risk for CHS and aggressive treatment of hypertension are recommended. PMID:27602202

  2. Real-Time Elastography Visualization and Histopathological Characterization of Rabbit Atherosclerotic Carotid Arteries.

    PubMed

    Wang, ZhenZhen; Liu, NaNa; Zhang, LiFeng; Li, XiaoYing; Han, XueSong; Peng, YanQing; Dang, MeiZheng; Sun, LiTao; Tian, JiaWei

    2016-01-01

    To evaluate the feasibility of non-invasive vascular real-time elastography imaging (RTE) in visualizing the composition of rabbit carotid atherosclerotic plaque as determined by histopathology, a rabbit model of accelerated carotid atherosclerosis was used. Thirty rabbits were randomly divided into two groups of 15 rabbits each. The first group was fed a cholesterol-rich diet and received balloon-induced injury the left common carotid artery endothelium, whereas the second group only received a cholesterol-rich diet. The rabbits were all examined in vivo with HITACHI non-invasive vascular real-time elastography (Hi-RTE) at baseline and 12 wk, and results from the elastography were compared with American Heart Association histologic classifications. Hi-RTE and the American Heart Association histologic classifications had good agreement, with weighted Cohen's kappa (95% confidence internal) of 0.785 (0.649-0.920). Strains of segmented plaques that were stained in different colors were statistically different (p < 0.0001). The sensitivity and specificity of elastograms for detecting a lipid core were 95.5% and 61.5%, respectively, and the area under the receiver operating characteristic curve was 0.789, with a 95% confidence interval of 0.679 to 0.876. This study is the first to indicate the feasibility of utilizing Hi-RTE in visualizing normal and atherosclerotic rabbit carotid arteries non-invasively. This affordable and reliable method can be widely applied in research of both animal and human peripheral artery atherosclerosis.

  3. Impairment of carotid-cardiac vagal baroreflex in wheelchair-dependent quadriplegics.

    PubMed

    Convertino, V A; Adams, W C; Shea, J D; Thompson, C A; Hoffler, G W

    1991-03-01

    The incidence of orthostatic hypotension can increase after prolonged exposure to chair rest and bedrest and is associated with post-bed rest impairment of the carotid-cardiac baroreflex response. We therefore hypothesized that the hypotension observed in humans confined to wheelchairs may be manifested by a reduced baroreflex sensitivity. We compared baroreflex responses of 16 wheelchair-dependent (WCD) quadriplegics with those of 15 able-bodied subjects (ABS) matched for age, height, and weight. Beat-to-beat R-R intervals were measured during application of graded pressures from 40 to -65 mmHg using a neck chamber for noninvasive stimulation of the carotid baroreceptors. Changes of R-R intervals were plotted against carotid distending pressures. The maximum slope of the stimulus-response relationship was greater (P less than 0.0001) in ABS (6.1 +/- 0.6 ms/mmHg) than in WCD (2.6 +/- 0.4 ms/mmHg). The range of the R-R interval response, i.e., the capacity to buffer blood pressure changes, was only 138 +/- 19 ms in WCD compared with 253 +/- 19 ms in ABS (P less than 0.001). Mean sitting systolic-to-diastolic blood pressures in WCD (92/60 mmHg) were less (P less than 0.0001) than in ABS (120/77 mmHg), although there were no significant differences between groups in supine resting blood pressures. Chronic loss of stimulation to carotid baroreceptors by routine standing posture is associated with attenuated sensitivity and reduced buffer capacity of the arterial baroreflex and hypotension during sitting in WCD patients.

  4. Interaction of semicircular canal stimulation with carotid baroreceptor reflex control of heart rate

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    The carotid-cardiac baroreflex contributes to the prediction of orthostatic tolerance; experimental attenuation of the reflex response leads to orthostatic hypotension in humans and animals. Anecdotal observations indicate that rotational head movements about the vertical axis of the body can also induce orthostatic bradycardia and hypotension through increased parasympathetic activity. We therefore measured the chronotropic response to carotid baroreceptor stimulation in 12 men during varying conditions of vestibulo-oculomotor stimulation to test the hypothesis that stimulation of the semicircular canals associated with head movements in the yaw plane inhibits cardioacceleration through a vagally mediated baroreflex. Carotid-cardiac baroreflex response was assessed by plotting R-R intervals (ms) at each of 8 neck pressure steps with their respective carotid distending pressures (mmHg). Calculated baroreflex gain (maximal slope of the stimulus-response relationship) was measured under 4 experimental conditions: 1) sinusoidal whole-body yaw rotation of the subject in the dark without visual fixation (combined vestibular-oculomotor stimulation); 2) yaw oscillation of the subject while tracking a small head-fixed light moving with the subject (vestibular stimulation without eye movements); 3) subject stationary while fixating on a small light oscillating in yaw at the same frequency, peak acceleration, and velocity as the chair (eye movements without vestibular stimulation); and 4) subject stationary in the dark (no eye or head motion). Head motion alone and with eye movement reduced baseline baroreflex responsiveness to the same stimulus by 30%. Inhibition of cardioacceleration during rotational head movements may have significant impact on functional performance in aerospace environments, particularly in high-performance aircraft pilots during high angular acceleration in aerial combat maneuvers or in astronauts upon return from spaceflight who already have

  5. [Non-invasive explorations of the carotid arteries (author's transl)].

    PubMed

    Persson, A V; Dyer, V E

    1981-01-01

    For the non-invasive evaluation of patients suspected of having extracranial carotid artery disease, the non-invasive vascular laboratory at the Lahey Clinic, Boston, Massachusetts uses three tests. Carotid phonoangiography (C.P.A.) by itself is 60% accurate, the Kartchner-McRae Oculoplethysmograph (O.P.G.) by itself 80% accurate, and the Echoflow doppler arterial imager, by itself 90% accurate. These examinations are used for surveillance of high-risk patients and to determine the need for carotid arteriography. In a series of 94 patients, the combination of these non-invasive methods yielded one false negative and 2 false positive studies, for an overall accuracy of 95%.

  6. Advanced oxidative protein products induced human keratinocyte apoptosis through the NOX-MAPK pathway.

    PubMed

    Sun, Baihui; Ding, Ruoting; Yu, Wenlin; Wu, Yanhong; Wang, Bulin; Li, Qin

    2016-07-01

    Impaired wound healing is a major diabetes-related complication. Keratinocytes play an important role in wound healing. Multiple factors have been proposed that can induce dysfunction in keratinocytes. The focus of present research is at a more specific molecular level. We investigated the role of advanced oxidative protein products (AOPPs) in inducing human immortalized keratinocyte (HaCaT) cell apoptosis and the cellular mechanism underlying the proapoptotic effect of AOPPs. HaCaT cells were treated with increasing concentrations of AOPP-human serum albumin or for increasing time durations. The cell viability was measured using the thiazolyl blue tetrazolium bromide method, and flow cytometry was used to assess the rate of cell apoptosis. A loss of mitochondrial membrane potential (MMP) and an increase in intracellular reactive oxygen species (ROS) were observed through a confocal laser scanning microscope system, and the level of ROS generation was determined using a microplate reader. Nicotinamide adenine dinucleotide phosphate oxidase (NOX)4, extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), and apoptosis-related downstream protein interactions were investigated using the Western blot analysis. We found that AOPPs triggered HaCaT cell apoptosis and MMP loss. After AOPP treatment, intracellular ROS generation increased in a time- and dose-dependent manner. Proapoptotic proteins, such as Bax, caspase 9/caspase 3, and poly(ADP-ribose) polymerase (PARP)-1 were activated, whereas anti-apoptotic Bcl-2 protein was downregulated. AOPPs also increased NOX4, ERK1/2, and p38 MAPK expression. Taken together, these findings suggest that extracellular AOPP accumulation triggered NOX-dependent ROS production, which activated ERK1/2 and p38 MAPK, and induced HaCaT cell apoptosis by activating caspase 3 and PARP-1.

  7. Next Generation Life Support Project: Development of Advanced Technologies for Human Exploration Missions

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.

    2012-01-01

    Next Generation Life Support (NGLS) is one of several technology development projects sponsored by the National Aeronautics and Space Administration s Game Changing Development Program. NGLS is developing life support technologies (including water recovery, and space suit life support technologies) needed for humans to live and work productively in space. NGLS has three project tasks: Variable Oxygen Regulator (VOR), Rapid Cycle Amine (RCA) swing bed, and Alternative Water Processing. The selected technologies within each of these areas are focused on increasing affordability, reliability, and vehicle self sufficiency while decreasing mass and enabling long duration exploration. The RCA and VOR tasks are directed at key technology needs for the Portable Life Support System (PLSS) for an Exploration Extravehicular Mobility Unit (EMU), with focus on prototyping and integrated testing. The focus of the Rapid Cycle Amine (RCA) swing-bed ventilation task is to provide integrated carbon dioxide removal and humidity control that can be regenerated in real time during an EVA. The Variable Oxygen Regulator technology will significantly increase the number of pressure settings available to the space suit. Current spacesuit pressure regulators are limited to only two settings while the adjustability of the advanced regulator will be nearly continuous. The Alternative Water Processor efforts will result in the development of a system capable of recycling wastewater from sources expected in future exploration missions, including hygiene and laundry water, based on natural biological processes and membrane-based post treatment. The technologies will support a capability-driven architecture for extending human presence beyond low Earth orbit to potential destinations such as the Moon, near Earth asteroids and Mars.

  8. Implications of carotid sinus hypersensitivity following preoperative embolization of a carotid body tumor. An indication for prophylactic intraoperative cardiac pacing.

    PubMed

    Bauer, Ashley M; Smith, Russell B; Thorell, William E

    2014-05-01

    IMPORTANCE Carotid body tumors are rare neoplasms of neural crest origin that are both highly vascularized and locally invasive. Treatment options for these tumors often include surgery with preoperative embolization, which can pose major cardiovascular risk to patients. As demonstrated by this case report, hemodynamic instability following preoperative embolization of a carotid body tumor may indicate severe carotid sinus hypersensitivity and the need for temporary cardiac pacing. OBSERVATIONS This case report describes a man in his early 30s who presented for staged surgical resection of bilateral carotid body tumors with preoperative embolization. After embolization of the second tumor, the patient displayed transient episodes of bradycardia and hypotension, which resolved with medical management. Surgery commenced, and with minimal manipulation intraoperatively, the patient became asystolic and required resuscitation. Following a negative cardiac workup, a temporary pacemaker was implanted, and surgical resection of the tumor was successfully completed. CONCLUSIONS AND RELEVANCE Carotid sinus hypersensitivity is a rare but serious risk of preoperative embolization of carotid body tumors. Postembolization bradycardia or hypotension should be assessed as potential harbingers of carotid sinus hypersensitivity, and the need for temporary intraoperative cardiac pacing should be strongly considered. PMID:24651937

  9. Hepatocyte growth factor protects human endothelial cells against advanced glycation end products-induced apoposis

    SciTech Connect

    Zhou Yijun . E-mail: zhou-yijun@hotmail.com; Wang Jiahe; Zhang Jin

    2006-06-02

    Advanced glycation end products (AGEs) form by a non-enzymatic reaction between reducing sugars and biological proteins, which play an important role in the pathogenesis of atherosclerosis. In this study, we assessed AGEs effects on human umbilical vein endothelial cells (HUVECs) growth, proliferation and apoptosis. Additionally, we investigated whether hepatocyte growth factor (HGF), an anti-apoptotic factor for endothelial cells, prevents AGEs-induced apoptosis of HUVECs. HUVECs were treated with AGEs in the presence or absence of HGF. Treatment of HUVECs with AGEs changed cell morphology, decreased cell viability, and induced DNA fragmentation, leading to apoptosis. Apoptosis was induced by AGEs in a dose- and time-dependent fashion. AGEs markedly elevated Bax and decreased NF-{kappa}B, but not Bcl-2 expression. Additionally, AGEs significantly inhibited cell growth through a pro-apoptotic action involving caspase-3 and -9 activations in HUVECs. Most importantly, pretreatment with HGF protected against AGEs-induced cytotoxicity in the endothelial cells. HGF significantly promoted the expression of Bcl-2 and NF-{kappa}B, while decreasing the activities of caspase-3 and -9 without affecting Bax level. Our data suggest that AGEs induce apoptosis in endothelial cells. HGF effectively attenuate AGEs-induced endothelial cell apoptosis. These findings provide new perspectives in the role of HGF in cardiovascular disease.

  10. Carotid siphon geometry and variants of the circle of Willis in the origin of carotid aneurysms.

    PubMed

    Silva Neto, Ângelo Raimundo; Câmara, Ródio Luis Brandão; Valença, Marcelo Moraes

    2012-12-01

    This study evaluated anatomical variants in the carotid siphon and of the circle of Willis in patients with aneurysms. We performed a retrospective analysis of cerebral angiographies. The Control Group was composed of patients without aneurysms. Posterior communicating artery (PcomA) aneurysms were more common in women (p<0.05), and the anterior communicating artery (AcomA) aneurysms in men (p<0.1). The incidence of fetal-type PcomA was higher in cases with co-occurring PcomA aneurysm (24 versus 8%, p<0.05). Patients with AcomA aneurysm had higher incidence of A1 hypoplasia (p<0.0001, OR=32.13, 95%CI 12.95-79.71) and lower frequency of fetal-type PcomA compared to their control counterparts (p=0.0125). The angle of carotid siphon was narrower in patients with PcomA aneurysm (27.3±19.1 versus 34.8±22.6, p=0.028). In conclusion, a narrower carotid siphon or the presence of fetal-type PcomA or A1 hypoplasia may cause hemodynamic stress, thereby promoting the formation of aneurysms in susceptible individuals.

  11. Comparison of Neurocognitive Outcomes after Carotid Endarterectomy and Carotid Artery Stenting.

    PubMed

    Kim, Jerry J; Schwartz, Samuel; Wen, Johnny; deVirgilio, Christian; Lobue, Abeline; Walot, Irwin; Koopmann, Matthew; Donayre, Carlos; White, Rodney A

    2015-10-01

    Cognitive and emotional outcomes after carotid endarterectomy (CEA) and carotid artery stenting with embolic protection device (CAS + EPD) are not clear. Patients were entered prospectively into a United States Food and Drug Administration-approved single-center physician-sponsored investigational device exemption between 2004 and 2010 and received either CEA or CAS + EPD. Patients underwent cognitive testing preprocedure and at 6, 12, and 60 months postprocedure. Cognitive domains assessed included attention, memory, executive, motor function, visual spatial functioning, language, and processing speed. Beck Depression and anxiety scales were also compared. There were a total of 38 patients that met conventional indications for carotid surgery (symptomatic with ≥50% stenosis or asymptomatic with ≥70% stenosis)-12 patients underwent CEA, whereas 26 patients underwent CAS + EPD. Both CEA and CAS + EPD patients showed postprocedure improvement in memory and executive function. No differences were seen at follow-up in regards to emotional dysfunction (depression and anxiety), attention, visual spatial functioning, language, motor function, and processing speed. Only two patients underwent neuropsychiatric testing at 60 months-these CAS + EPD patients showed sustained improvement in memory, visual spatial, and executive functions. In conclusion, cognitive and emotional outcomes were similar between CEA and CAS + EPD patients. PMID:26463299

  12. The relationship between preoperative serum cortisol level and the stability of plaque in carotid artery stenosis patients undergoing carotid endarterectomy

    PubMed Central

    Qin, Feng; Sun, Yudong; Hu, Wenping; Wei, Xiaolong; Li, Zhenjiang

    2016-01-01

    Background Stability of plaque has been implicated as risk factor for stroke. Serum cortisol regulates lipoprotein metabolism and immune response, contributing to plaque stability in atherosclerosis. However, the relationship between serum cortisol and stability of carotid plaque has not been well characterized. We conducted a serology analysis to identify the relationship between serum cortisol and carotid plaque stability. Methods Between May 2013 to October 2015, 73 patients with carotid stenosis patients undergoing carotid endarterectomy (CEA) were enrolled in our study. Serum cortisol was analyzed at 8:00 AM in the morning before surgery via liquid chromatography tandem mass spectrometry. According to the classification made by the American Heart Association, hematoxylin-and-eosin staining was performed to divide these patients into either a stable or unstable group, according to the morphology of fibrous cap, lipid core and intima layer. A curve fitting method was used to identify the relationship between preoperative serum cortisol and stability of carotid plaque. Univariate and multivariate logistic regression analysis were used to identify carotid plaque stability-associated serum cortisol. Results Curve fitting’s result represents a U-shape characteristic. A total of 314.92 and 395.23 nmol/L were considered as the cut point for preoperative serum cortisol when trisected the patients. When adjusted for degree of stenosis, hyperlipemia, smoking and low-density lipoprotein (LDL), univariate and multivariate logistic regression analysis’ results demonstrated that preoperative serum cortisol can significantly affect carotid plaque stability. The odds ratio values in multivariate logistic regression analysis for C reactive protein (CRP), white blood cell (WBC), interleukin-6 (IL-6) and preoperative serum cortisol level were 7.67 and 20.86 respectively. Conclusions Preoperative serum cortisol was associated with stability of carotid plaque in patients

  13. Stent-Protected Carotid Angioplasty Using a Membrane Stent: A Comparative Cadaver Study

    SciTech Connect

    Mueller-Huelsbeck, Stefan Guehne, Albrecht; Tsokos, Michael; Huesler, Erhard J.; Schaffner, Silvio R.; Paulsen, Friedrich; Hedderich, Juergen; Heller, Martin; Jahnke, Thomas

    2006-08-15

    Purpose. To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. Methods. Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 {mu}m effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. Results. Absolute numbers of particles (median; >100 {mu}m) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p 0.011) and the largest number (p = 0.054) of particles. Conclusions. On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary

  14. Carotid and vertebral artery dissection syndromes

    PubMed Central

    Thanvi, B; Munshi, S; Dawson, S; Robinson, T

    2005-01-01

    Cervicocerebral arterial dissections (CAD) are an important cause of strokes in younger patients accounting for nearly 20% of strokes in patients under the age of 45 years. Extracranial internal carotid artery dissections comprise 70%–80% and extracranial vertebral dissections account for about 15% of all CAD. Aetiopathogenesis of CAD is incompletely understood, though trauma, respiratory infections, and underlying arteriopathy are considered important. A typical picture of local pain, headache, and ipsilateral Horner's syndrome followed after several hours by cerebral or retinal ischaemia is rare. Doppler ultrasound, MRI/MRA, and CT angiography are useful non-invasive diagnostic tests. The treatment of extracranial CAD is mainly medical using anticoagulants or antiplatelet agents although controlled studies to show their effectiveness are lacking. The prognosis of extracranial CAD is generally much better than that of the intracranial CAD. Recurrences are rare in CAD. PMID:15937204

  15. Plasma lecithin:cholesterol acyltransferase and carotid intima-media thickness in European individuals at high cardiovascular risk

    PubMed Central

    Calabresi, Laura; Baldassarre, Damiano; Simonelli, Sara; Gomaraschi, Monica; Amato, Mauro; Castelnuovo, Samuela; Frigerio, Beatrice; Ravani, Alessio; Sansaro, Daniela; Kauhanen, Jussi; Rauramaa, Rainer; de Faire, Ulf; Hamsten, Anders; Smit, Andries J.; Mannarino, Elmo; Humphries, Steve E.; Giral, Philippe; Veglia, Fabrizio; Sirtori, Cesare R.; Franceschini, Guido; Tremoli, Elena

    2011-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. LCAT is a major factor in HDL remodeling and metabolism, and it has long been believed to play a critical role in macrophage reverse cholesterol transport (RCT). The effect of LCAT on human atherogenesis is still controversial. In the present study, the plasma LCAT concentration was measured in all subjects (n = 540) not on drug treatment at the time of enrollment in the multicenter, longitudinal, observational IMPROVE study. Mean and maximum intima-media thickness (IMT) of the whole carotid tree was measured by B-mode ultrasonography in all subjects. In the entire cohort, LCAT quartiles were not associated with carotid mean and maximum IMT (P for trend 0.95 and 0.18, respectively), also after adjustment for age, gender, HDL-cholesterol (HDL-C), and triglycerides. No association between carotid IMT and LCAT quartiles was observed in men (P=0.30 and P=0.99 for mean and maximum IMT, respectively), whereas carotid IMT increased with LCAT quartiles in women (P for trend 0.14 and 0.019 for mean and maximum IMT, respectively). The present findings support the concept that LCAT is not required for an efficient reverse cholesterol transport and that a low plasma LCAT concentration and activity is not associated with increased atherosclerosis. PMID:21596929

  16. Assessment of Carotid Artery Stenosis and the Use of Statins

    PubMed Central

    Whayne, Thomas F.

    2015-01-01

    General thinking has previously centered on managing carotid artery stenosis (CAS) by carotid endarterectomy and subsequently, stenting for higher risk patients. However for CAS and other forms of vascular disease, especially when asymptomatic, there is new emphasis on defining underlying mechanisms. Knowledge of these mechanisms can lead to medical treatments that result in possible atherosclerotic plaque stabilization, and even plaque regression, including in the patient with CAS. For now, the key medication class for a medical approach are the statins. Their use is supported by good cardiovascular clinical trial evidence including some directed carotid artery studies, especially with a demonstrated decrease in carotid intima-media thickness. Procedural controversy still exists but the current era in medicine offers significant support for medical management of asymptomatic CAS while techniques to recognize the vulnerable plaque evolve. If CAS converts to a symptomatic status, early referral for endarterectomy or stenting is indicated. PMID:26417184

  17. Branch retinal artery occlusion following carotid stenting: A case report

    PubMed Central

    Sun, Ran; Peng, Xiao-Yan; You, Qi-Sheng; Jiao, Li-Qun; Liu, Da-Chuan

    2016-01-01

    A 70 year old male was diagnosed with carotid stenosis and underwent carotid artery stenting (CAS). Severe postoperative complications arose subsequent to the procedure, including decreased visual acuity and symptoms of a visual field defect, and the patient was eventually diagnosed with retinal artery embolism. CAS reduces carotid plaque; however, the subsequent shedding of carotid plaque may cause retinal artery embolism, resulting in the serious loss of visual function in patients. This complication is of paramount importance and requires great consideration from the neurologist and the patients undergoing CAS. Ophthalmic evaluation is paramount following CAS due to the possibility of embolic occlusion of the retinal artery. It is imperative that patients be informed of the risk of permanent vision loss as a result of CAS.

  18. Carotid body tumor imitator: An interesting case of Castleman's disease

    PubMed Central

    Shakir, Hakeem J.; Diletti, Sara M.; Hart, Alexandra M.; Meyers, Joshua E.; Dumont, Travis M.; Siddiqui, Adnan H.

    2015-01-01

    Background: There are very few reports in the literature of Castleman's disease affecting the carotid artery and a single previous report of a case of Castleman's disease of the neck originally mistaken as a carotid body tumor. Case Description: We describe a rare case of Castleman's disease, manifesting with classic radiographic hallmarks of a carotid body tumor. The postoperative pathologic examination identified the resected mass as Castleman's lymphadenopathy. The management of this particular case is discussed, and the findings are highlighted. Conclusions: We present a unique case of a tumor initially and incorrectly diagnosed as a carotid body tumor. However, after comprehensive treatment with endovascular and surgical modalities and subsequent pathologic examination, the diagnosis of this rare entity was made. PMID:26677415

  19. Common carotid artery dissection caused by radiotherapy: A case report

    PubMed Central

    Wang, Jiayan; Yue, Dandan; Chen, Xin; Wei, Zhenyu; Lu, Wenmei; Wu, Danhong

    2016-01-01

    In the present study, a case of acute cerebral infarction with radiation-induced carotid artery dissection is reported. Carotid artery dissection is generally asymptomatic at the early stages. Due to the non-specific clinical manifestations of carotid artery dissection, a detailed inquiry of the past history of a patient has a critical role in making a diagnosis of radiation-induced common carotid artery dissection. Onset of acute ischemic stroke is the predominant manifestation, and for patients with a history of head-and-neck radiotherapy, dissection should be considered. The condition may progress rapidly, and result in a poor prognosis. Therefore, a correct early diagnosis and initiation of appropriate therapy may lead to rapid recovery, and influence the overall prognosis.

  20. Ultrasonic imaging and oculoplethysmography in diagnosis of carotid occlusive disease.

    PubMed

    Wasserman, D H; Hobson, R W; Lynch, T G; Berry, S M; Jamil, Z

    1983-10-01

    Pulsed Doppler ultrasonic imaging (UI) of the cervical carotid artery provides flow-dependent anatomic detail of the carotid bifurcation, while oculoplethysmography (Kartchner) (OPG-K) and ocular pneumoplethysmography (Gee) (OPG-G) reflect changes in flow and pressure resulting from hemodynamically significant lesions. We examined 66 patients prospectively with UI, OPG-K, and OPG-G to compare the relative accuracy of these techniques with contrast arteriography. Both UI and OPG-G were significantly more accurate than OPG-K. While the accuracies of UI and OPG-G were not significantly different, their combined use resulted in a significant increase in sensitivity compared with that of Doppler imaging alone. In addition, UI correctly identified 22 (85%) of 26 occlusions of the internal carotid artery. The use of UI and OPG-G together provided accurate anatomic and hemodynamic information useful in the evaluation of carotid occlusive disease.

  1. Common carotid artery dissection caused by radiotherapy: A case report

    PubMed Central

    Wang, Jiayan; Yue, Dandan; Chen, Xin; Wei, Zhenyu; Lu, Wenmei; Wu, Danhong

    2016-01-01

    In the present study, a case of acute cerebral infarction with radiation-induced carotid artery dissection is reported. Carotid artery dissection is generally asymptomatic at the early stages. Due to the non-specific clinical manifestations of carotid artery dissection, a detailed inquiry of the past history of a patient has a critical role in making a diagnosis of radiation-induced common carotid artery dissection. Onset of acute ischemic stroke is the predominant manifestation, and for patients with a history of head-and-neck radiotherapy, dissection should be considered. The condition may progress rapidly, and result in a poor prognosis. Therefore, a correct early diagnosis and initiation of appropriate therapy may lead to rapid recovery, and influence the overall prognosis. PMID:27699045

  2. Aneurysm of the internal carotid artery after minor trauma.

    PubMed

    Laissaoui, Younès; Noureddine El Alami, Mohamed

    2014-01-01

    We report a rare case of posttraumatic aneurysm of the internal carotid artery. The aneurysm was surgically removed, followed by a simple postoperative course. Such lesions should be highly suspected in cases of penetration into the retroangulomandibular neck region.

  3. Hematopoietic specification from human pluripotent stem cells: current advances and challenges toward de novo generation of hematopoietic stem cells.

    PubMed

    Slukvin, Igor I

    2013-12-12

    Significant advances in cellular reprogramming technologies and hematopoietic differentiation from human pluripotent stem cells (hPSCs) have already enabled the routine production of multiple lineages of blood cells in vitro and opened novel opportunities to study hematopoietic development, model genetic blood diseases, and manufacture immunologically matched cells for transfusion and cancer immunotherapy. However, the generation of hematopoietic cells with robust and sustained multilineage engraftment has not been achieved. Here, we highlight the recent advances in understanding the molecular and cellular pathways leading to blood development from hPSCs and discuss potential approaches that can be taken to facilitate the development of technologies for de novo production of hematopoietic stem cells.

  4. Carotid and Aortic Stiffness in Patients with Heterozygous Familial Hypercholesterolemia

    PubMed Central

    Meshkov, Alexey N.; Rozhkova, Tatyana A.; Kalinina, Maria V.; Deev, Alexander D.; Rogoza, Anatoliy N.; Balakhonova, Tatyana V.; Boytsov, Sergey A.

    2016-01-01

    Background The role of plasma cholesterol in impairing arterial function and elasticity remains unclear. We evaluated arterial stiffness, measured locally in the common carotid artery by high-resolution echo-tracking, and aortic stiffness, using carotid-femoral pulse wave velocity (PWV) (the “gold-standard” measurement of arterial stiffness), in treatment-naive patients with heterozygous familial hypercholesterolemia (FH). Methods The study included 66 patients with FH (10–66 years old) and 57 first-degree relatives without FH (11–61 years old). Carotid-femoral PWV was determined by SphygmoCor (AtCor, Australia). The parameters of carotid stiffness β-index, Peterson elastic modulus and local PWV were assessed with regard to the common carotid artery at a distance of 1cm from the bifurcation (AlokaProsound Alpha7, Japan). Results FH patients showed significantly higher β-index (6.3(4.8–8.2) vs. 5.2(4.2–6.4), p = 0.005), Ep (78(53–111) kPa vs. 62(48–79) kPa, p = 0.006), local PWV (5.4(4.5–6.4) m/c vs. 4.7(4.2–5.4) m/c, p = 0.005), but comparable values of carotid-femoral PWV (6.76(7.0–7.92) m/c vs. 6.48(6.16–7.12) m/c, p = 0.138). Carotid arteries and the aorta stiffened with age in patients with FH, but after 30 years, carotid arteries stiffened more significantly than the aorta. Conclusions Our study demonstrated that treatment-naive patients with FH had stiffer carotid arteries than their relatives, but showed no difference in aortic stiffness. We also found out that the rate of reduction of elasticity of the aorta and carotid arteries in FH patients varies: it is observed earlier in carotid arteries than in the aorta. PMID:27434535

  5. Cavernous Carotid Artery Pseudoaneurysm Following a Radical Cavernous Sinus Resection

    PubMed Central

    Katzir, Miki; Gil, Ziv; Cohen, José Enrique; Sviri, Gill Efraim

    2016-01-01

    Iatrogenic cavernous carotid pseudoaneurysms are a special group among other intracranial aneurysms. They can occur during the dissection phase of the surgery if the tumor encases a vessel. Complications of their rupture as hemorrhage or stroke are life threatening. Early recognition and treatment is mandatory to avoid catastrophic sequelae. We present the successful diagnosis and endovascular treatment of a postoperative cavernous carotid pseudoaneurysm following radical cavernous sinus resection. PMID:27330923

  6. Cavernous Carotid Artery Pseudoaneurysm Following a Radical Cavernous Sinus Resection.

    PubMed

    Katzir, Miki; Gil, Ziv; Cohen, José Enrique; Sviri, Gill Efraim

    2016-06-01

    Iatrogenic cavernous carotid pseudoaneurysms are a special group among other intracranial aneurysms. They can occur during the dissection phase of the surgery if the tumor encases a vessel. Complications of their rupture as hemorrhage or stroke are life threatening. Early recognition and treatment is mandatory to avoid catastrophic sequelae. We present the successful diagnosis and endovascular treatment of a postoperative cavernous carotid pseudoaneurysm following radical cavernous sinus resection. PMID:27330923

  7. ESVS guidelines. Invasive treatment for carotid stenosis: indications, techniques.

    PubMed

    Liapis, C D; Bell, P R F; Mikhailidis, D; Sivenius, J; Nicolaides, A; Fernandes e Fernandes, J; Biasi, G; Norgren, L

    2009-04-01

    The European Society for Vascular Surgery brought together a group of experts in the field of carotid artery disease to produce updated guidelines for the invasive treatment of carotid disease. The recommendations were rated according to the level of evidence. Carotid endarterectomy (CEA) is recommended in symptomatic patients with >50% stenosis if the perioperative stroke/death rate is <6% [A], preferably within 2 weeks of the patient's last symptoms [A]. CEA is also recommended in asymptomatic men <75 years old with 70-99% stenosis if the perioperative stroke/death risk is <3% [A]. The benefit from CEA in asymptomatic women is significantly less than in men [A]. CEA should therefore be considered only in younger, fit women [A]. Carotid patch angioplasty is preferable to primary closure [A]. Aspirin at a dose of 75-325 mg daily and statins should be given before, during and following CEA. [A] Carotid artery stenting (CAS) should be performed only in high-risk for CEA patients, in high-volume centres with documented low peri-operative stroke and death rates or inside a randomized controlled trial [C]. CAS should be performed under dual antiplatelet treatment with aspirin and clopidogrel [A]. Carotid protection devices are probably of benefit [C].

  8. Imaging of the Fibrous Cap in Atherosclerotic Carotid Plaque

    SciTech Connect

    Saba, Luca; Potters, Fons; Lugt, Aad van der; Mallarini, Giorgio

    2010-08-15

    In the last two decades, a substantial number of articles have been published to provide diagnostic solutions for patients with carotid atherosclerotic disease. These articles have resulted in a shift of opinion regarding the identification of stroke risk in patients with carotid atherosclerotic disease. In the recent past, the degree of carotid artery stenosis was the sole determinant for performing carotid intervention (carotid endarterectomy or carotid stenting) in these patients. We now know that the degree of stenosis is only one marker for future cerebrovascular events. If one wants to determine the risk of these events more accurately, other parameters must be taken into account; among these parameters are plaque composition, presence and state of the fibrous cap (FC), intraplaque haemorrhage, plaque ulceration, and plaque location. In particular, the FC is an important structure for the stability of the plaque, and its rupture is highly associated with a recent history of transient ischaemic attack or stroke. The subject of this review is imaging of the FC.

  9. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  10. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement

    PubMed Central

    Hussain, Ahmad S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates.

  11. Intravascular Ultrasound for Intracranial and Extracranial Carotid Artery Stent Placement.

    PubMed

    Hussain, Ahmad S; Hussain, Namath S

    2016-01-01

    Intravascular ultrasound (IVUS) can provide valuable information regarding endoluminal morphology. We present the first description of IVUS-guided intracranial and extracranial carotid artery stent placement for arterial dissection. A 41-year-old female with a sudden-onset headache and blurred vision underwent a computed tomography (CT) angiogram imaging that revealed bilateral carotid artery dissections (BCAD) and a left vertebral artery dissection (VAD). Endovascular treatment (EVT) of a long segment right carotid artery dissection (CAD) was performed employing two Carotid WALLSTENT™ Monorails™ (8 x 36 mm, 10 x 31 mm) (Boston Scientific, Marlborough, MA). With the help of the IVUS, the distal stent was placed up to the petrous carotid artery, followed by the placement of the second stent in the immediate proximal location with some overlap that extended down to the carotid artery bulb. Intraoperative angiography and post-stenting IVUS revealed excellent stent placement with good resolution of the dissection and good luminal patency with pseudolumen obliteration. Stent use for intracranial circulation dissections will continue to be a favorable option given the decreased morbidity of endovascular therapy in this location. As endovascular surgeons become more facile with the use of IVUS, using it as a guide for stent placement and post-stenting confirmation will help them to ensure proper positioning and improved patency rates. PMID:27672529

  12. Endovascular Treatment of Iatrogenic and Traumatic Carotid Artery Dissection

    SciTech Connect

    Schulte, Stefan; Donas, Konstantinos P. Pitoulias, Georgios A.; Horsch, Svante

    2008-09-15

    This paper reports on the early and midterm results of endovascular treatment of acute carotid artery dissections, its specific problems, and its limitations. We encountered seven patients with symptomatic extracranial carotid artery dissection, three cases of which occurred after carotid endarterectomy, two after carotid angioplasty and stenting, and two after trauma. Balloon-expandable and self-expanding stents were placed using a transfemoral approach. Success in restoring the carotid lumen was achieved in all patients. No procedure-related complications occurred. All patients experienced significant clinical improvement while in the hospital and achieved complete long-term recovery. At follow-up (mean, 22.4 months), good luminal patency of the stented segments was observed. In conclusion, in this small series, primary stent-supported angioplasty seems to be a safe and effective strategy in the treatment of selected patients having acute traumatic extracranial carotid artery dissection, with excellent early and midterm results. Larger series and longer-term follow-up are required before definitive recommendations can be made.

  13. Ciprofloxacin inhibits advanced glycation end products-induced adhesion molecule expression on human monocytes

    PubMed Central

    Mori, S; Takahashi, HK; Liu, K; Wake, H; Zhang, J; Liu, R; Yoshino, T; Nishibori, M

    2010-01-01

    BACKGROUND AND PURPOSE Advanced glycation end products (AGEs) subtypes, proteins or lipids that become glycated after exposure to sugars, can induce complications in diabetes. Among the various AGE subtypes, glyceraldehyde-derived AGE (AGE-2) and glycolaldehyde-derived AGE (AGE-3) are involved in inflammation in diabetic patients; monocytes are activated by these AGEs. Ciprofloxacin (CIP), a fluorinated 4-quinolone, is often used clinically to treat infections associated with diabetis due to its antibacterial properties. It also modulates immune responses in human peripheral blood mononuclear cells (PBMC) therefore we investigated the involvement of AGEs in these effects. EXPERIMENTAL APPROACH Expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2 and CD40 was examined by flow cytometry. The production of tumour necrosis factor (TNF)-α, interferon (IFN)-γ, prostaglandin E2 (PGE2) and cAMP were determined by enzyme-linked immunosorbent assay. Cyclooxygenase (COX)-2 expression was determined by Western blot analysis. Lymphocyte proliferation was determined by [3H]-thymidine uptake. KEY RESULTS CIP induced PGE2 production in monocytes, irrespective of the presence of AGE-2 and AGE-3, by enhancing COX-2 expression; this led to an elevation of intracellular cAMP in monocytes. Non-selective and selective COX-2 inhibitors, indomethacin and NS398, inhibited CIP-induced PGE2 and cAMP production. In addition, CIP inhibited AGE-2- and AGE-3-induced expressions of ICAM-1, B7.1, B7.2 and CD40 in monocytes, the production of TNF-α and IFN-γ and lymphocyte proliferation in PBMC. Indomethacin, NS398 and a protein kinase A inhibitor, H89, inhibited the actions of CIP. CONCLUSIONS AND IMPLICATIONS CIP exerts immunomodulatory activity via PGE2, implying therapeutic potential of CIP for the treatment of AGE-2- and AGE-3-induced inflammatory responses. PMID:20718752

  14. Technology Alignment and Portfolio Prioritization (TAPP): Advanced Methods in Strategic Analysis, Technology Forecasting and Long Term Planning for Human Exploration and Operations, Advanced Exploration Systems and Advanced Concepts

    NASA Technical Reports Server (NTRS)

    Funaro, Gregory V.; Alexander, Reginald A.

    2015-01-01

    The Advanced Concepts Office (ACO) at NASA, Marshall Space Flight Center is expanding its current technology assessment methodologies. ACO is developing a framework called TAPP that uses a variety of methods, such as association mining and rule learning from data mining, structure development using a Technological Innovation System (TIS), and social network modeling to measure structural relationships. The role of ACO is to 1) produce a broad spectrum of ideas and alternatives for a variety of NASA's missions, 2) determine mission architecture feasibility and appropriateness to NASA's strategic plans, and 3) define a project in enough detail to establish an initial baseline capable of meeting mission objectives ACO's role supports the decision­-making process associated with the maturation of concepts for traveling through, living in, and understanding space. ACO performs concept studies and technology assessments to determine the degree of alignment between mission objectives and new technologies. The first step in technology assessment is to identify the current technology maturity in terms of a technology readiness level (TRL). The second step is to determine the difficulty associated with advancing a technology from one state to the next state. NASA has used TRLs since 1970 and ACO formalized them in 1995. The DoD, ESA, Oil & Gas, and DoE have adopted TRLs as a means to assess technology maturity. However, "with the emergence of more complex systems and system of systems, it has been increasingly recognized that TRL assessments have limitations, especially when considering [the] integration of complex systems." When performing the second step in a technology assessment, NASA requires that an Advancement Degree of Difficulty (AD2) method be utilized. NASA has used and developed or used a variety of methods to perform this step: Expert Opinion or Delphi Approach, Value Engineering or Value Stream, Analytical Hierarchy Process (AHP), Technique for the Order of

  15. 78 FR 8546 - National Center for Advancing Translational Sciences (NCATS) and National Human Genome Research...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ...) and National Human Genome Research Institute (NHGRI): Cooperative Research and Development Agreement... the National Human Genome Research Institute (NHGRI), the National Institutes of Health (NIH),...

  16. Carotid body oxygen sensing and adaptation to hypoxia.

    PubMed

    López-Barneo, José; Macías, David; Platero-Luengo, Aida; Ortega-Sáenz, Patricia; Pardal, Ricardo

    2016-01-01

    The carotid body (CB) is the principal arterial chemoreceptor that mediates the hyperventilatory response to hypoxia. Our understanding of CB function and its role in disease mechanisms has progressed considerably in the last decades, particularly in recent years. The sensory elements of the CB are the neuron-like glomus cells, which contain numerous transmitters and form synapses with afferent sensory fibers. The activation of glomus cells under hypoxia mainly depends on the modulation of O2-sensitive K(+) channels which leads to cell depolarization and the opening of Ca(2+) channels. This model of sensory transduction operates in all mammalian species studied thus far, including man. However, the molecular mechanisms underlying the modulation of ion channel function by changes in the O2 level are as yet unknown. The CB plays a fundamental role in acclimatization to sustained hypoxia. Mice with CB atrophy or patients who have undergone CB resection due to surgical treatments show a marked intolerance to even mild hypoxia. CB growth under hypoxia is supported by the existence of a resident population of neural crest-derived stem cells of glia-like phenotype. These stem cells are not highly affected by exposure to low O2 tension; however, there are abundant synapse-like contacts between the glomus cells and stem cells (chemoproliferative synapses), which may be needed to trigger progenitor cell proliferation and differentiation under hypoxia. CB hypo- or hyper-activation may also contribute to the pathogenesis of several prevalent human diseases.

  17. The carotid body and arousal in the fetus and neonate.

    PubMed

    Darnall, Robert A

    2013-01-01

    Arousal from sleep is a major defense mechanism in infants against hypoxia and/or hypercapnia. Arousal failure may be an important contributor to SIDS. Areas of the brainstem that have been found to be abnormal in a majority of SIDS infants are involved in the arousal process. Arousal is sleep state dependent, being depressed during AS in most mammals, but depressed during QS in human infants. Repeated exposure to hypoxia causes a progressive blunting of arousal that may involve medullary raphe GABAergic mechanisms. Whereas CB chemoreceptors contribute heavily to arousal in response to hypoxia, serotonergic central chemoreceptors have been implicated in the arousal response to CO(2). Pulmonary or chest wall mechanoreceptors also contribute to arousal in proportion to the ventilatory response and decreases in their input may contribute to depressed arousal during AS. Little is known about specific arousal pathways beyond the NTS. Whether CB chemoreceptor stimulation directly stimulates arousal centers or whether this is done indirectly through respiratory networks remains unknown. This review will focus on arousal in response to hypoxia and CO(2) in the fetus and newborn and will outline what we know (and do not know) about the involvement of the carotid body in this process. PMID:22684039

  18. Association of SERPINA9 gene variants with carotid artery atherosclerosis: the Atherosclerosis Risk in Communities (ARIC) Carotid MRI Study

    PubMed Central

    Tang, Weihong; Morrison, Alanna; Wasserman, Bruce A; Folsom, Aaron R; Sun, Wei; Campbell, Stephen; Kao, W H Linda; Boerwinkle, Eric

    2013-01-01

    The SNP rs11628722 in the SERPINA9 gene was previously associated with incident ischemic stroke in the Atherosclerosis Risk in Communities (ARIC) study. Centerin, the protein encoded by SERPINA9, is involved in maturation and maintenance of naïve B cells, which play a role in atherogenesis. We investigated whether 21 tag SNPs in the SERPINA9 gene are associated with features of carotid artery atherosclerotic plaque measured by magnetic resonance imaging (MRI). Carotid MRI data were obtained from 1,282 European Americans and 341 African Americans of the ARIC Carotid MRI study, which recruited participants from ARIC by a stratified sampling plan that over-sampled participants with carotid intima-media thickening. Five MRI measures, focused on carotid wall volume, wall thickness, and lipid core, were analyzed. Genetic associations between the MRI measurements and each of the 21 SNPs were analyzed in linear regression models with adjustment for sample weights and traditional risk factors. Rs11628722 was tested a priori. In African Americans, rs11628722 was significantly associated with carotid wall volume (p < 0.05). Among the other 20 SNPs, adjusted for multiple testing, rs4905204, which encodes an Ala to Val amino acid change, was significantly associated with maximum wall thickness (p < 0.000625) and suggestively associated with total wall volume (p < 0.0026) in European Americans. In conclusion, SNPs in the SERPINA9 gene showed race-specific associations with characteristics of carotid atherosclerotic plaques. Replications in other populations are needed to validate findings of this study and to establish the SERPINA9 gene as a candidate in the etiology of carotid atherosclerosis. PMID:24319541

  19. POA 01-3 CAROTID-FEMORAL PULSE WAVE VELOCITY IS THE BEST BIOMECHANICAL MARKER FOR RISK PREDICTION.

    PubMed

    Mitchell, Gary F

    2016-09-01

    Aortic stiffness increases markedly with advancing age and is associated with widening of pulse pressure, an increase in pulse wave velocity, earlier return of reflected waves to the proximal aorta and increased risk for target organ damage and adverse outcomes. Various measures of arterial stiffness and wave reflection have been proposed as potential surrogate measures of aortic stiffness. Carotid-femoral pulse wave velocity is a direct measure of aortic wall stiffness that is easily measured with modest requirements for special equipment and training and has been shown to predict events and reclassify cardiovascular disease risk in models that include standard cardiovascular disease risk factors. Therefore, carotid-femoral pulse wave velocity has emerged as the best biomechanical marker for risk prediction. PMID:27643104

  20. MR Imaging of Carotid Plaque Composition During Lipid-Lowering Therapy

    PubMed Central

    Zhao, Xue-Qiao; Dong, Li; Hatsukami, Tom; Phan, Binh An; Chu, Baocheng; Moore, Andrew; Lane, Trevor; Neradilek, Moni B.; Polissar, Nayak; Monick, Duane; Lee, Colin; Underhill, Hunter; Yuan, Chun

    2013-01-01

    OBJECTIVES The purpose of this study was to test the lipid depletion hypothesis and to establish the time course of change in carotid plaque morphology and composition during lipid therapy using high-resolution magnetic resonance imaging (MRI). BACKGROUND Lipid therapy is thought to improve plaque stability and reduce cardiovascular events by targeting the plaque rupture risk features such as large lipid core, thin fibrous cap, and high level of inflammatory infiltrates. However, the plaque stabilizing process during lipid therapy has not been clearly demonstrated in humans and in vivo. METHODS Subjects with coronary or carotid artery disease, apolipoprotein B ≥120 mg/dl, and lipid treatment history <1 year, were randomly assigned to atorvastatin monotherapy or to atorvastatin-based combination therapies with appropriate placebos for 3 years. All subjects underwent high-resolution, multicontrast bilateral carotid MRI scans at baseline and annually for 3 years. All images were analyzed for quantification of wall area and plaque composition blinded to therapy, laboratory results, and clinical course. RESULTS After 3 years of lipid therapy, the 33 subjects with measurable lipid-rich necrotic core (LRNC) at baseline had a significant reduction in plaque lipid content: LRNC volume decreased from 60.4 ± 59.5 mm3 to 37.4 ± 69.5 mm3 (p < 0.001) and %LRNC (LRNC area/wall area in the lipid-rich regions) from 14.2 ± 7.0% to 7.4 ± 8.2% (p < 0.001). The time course showed that %LRNC decreased by 3.2 (p < 0.001) in the first year, by 3.0 (p = 0.005) in the second year, and by 0.91 (p = 0.2) in the third year. Changes in LRNC volume followed the same pattern. Percent wall volume (100 × wall/outer wall, a ratio of volumes) in the lipid-rich regions significantly decreased from 52.3 ± 8.5% to 48.6 ± 9.7% (p = 0.002). Slices containing LRNC had significantly more percent wall volume reduction than those without (−4.7% vs. −1.4%, p = 0.02). CONCLUSIONS Intensive lipid

  1. Contrast-enhanced ultrasound imaging of the vasa vasorum of carotid artery plaque

    PubMed Central

    Song, Ze-Zhou; Zhang, Yan-Ming

    2015-01-01

    The vasa vasorum of carotid artery plaque is a novel marker of accurately evaluating the vulnerability of carotid artery plaque, which was associated with symptomatic cerebrovascular and cardiovascular disease. The presence of ultrasound contrast agents in carotid artery plaque represents the presence of the vasa vasorum in carotid artery plaque because the ultrasound contrast agents are strict intravascular tracers. Therefore, contrast-enhanced ultrasound (CEUS) is a novel and safe imaging modality for evaluating the vasa vasorum in carotid artery plaque. However, there are some issues that needs to be assessed to embody fully the clinical utility of the vasa vasorum in carotid artery plaque with CEUS. PMID:26120382

  2. Carotid occlusive disease as a risk factor in major cardiovascular surgery.

    PubMed

    Kartchner, M M; McRae, L P

    1982-08-01

    Carotid occlusive disease in patients undergoing major cardiovascular surgery raises the question of the perioperative risk factor of stroke. We evaluated 234 cardiovascular patients preoperatively by oculoplethysmography (OPG) to detect hemodynamically severe carotid occlusive disease. The perioperative stroke risk without flow-reducing carotid occlusive disease was 1%, in contrast to a 17% incidence of stroke when OPG studies indicated internal carotid artery stenosis of more than 60%. Oculoplethysmography is a reliable indicator of hemodynamically severe carotid occlusive disease with an associated high risk of stroke that warrants prophylactic carotid endarterectomy before major cardiovascular surgery.

  3. Carotid Artery Stenting: Review of Technique and Update of Recent Literature

    PubMed Central

    Ahn, Sun Ho; Prince, Ethan A.; Dubel, Gregory J.

    2013-01-01

    Stroke is the fourth leading cause of death and the number one cause of long-term disability in the United States. Carotid stenosis is an important cause of ischemic strokes, accounting for 20 to 25%. Previous studies have established carotid endarterectomy as standard of care of symptomatic patients with > 50% stenosis and asymptomatic patients with > 60% stenosis; recently, carotid artery stenting has emerged as an alternative treatment for carotid stenosis. Several studies have been published comparing carotid artery stenting with endarterectomy with mixed results. In this article, the authors discuss carotid artery stenting technique, the results from the most recent trials, and future directions. PMID:24436551

  4. Automated calculation of bifurcation carotid angle for analyzing the risk of carotis plaques by using carotid CT angiographic images

    NASA Astrophysics Data System (ADS)

    Demir, N.; Demir, S.

    2015-05-01

    The aim of this study is calculation of bifurcation carotid angle by detection of vessel boundaries to assist the medical doctors if this angle is a risk factor about formation of carotid plaques.Carotid ct angiography images are clustered automatically by ISODATA unsupervised classification algorithm. Since the spectral digital numbers (DN) of vessel pixels are bigger than the other part of the images, the cluster which has the biggest median value of DN among all other classes gives the vessel class. The cluster image in raster format is converted into the vector format which allows working on the vessel geometry. The converted vector vessel cluster dataset has been simplified using Douglas-Peucker algorithm to eliminate the zigzag effects of pixel data which are remained on the vector form dataset. Then the cluster polygon is converted to lines and the vertices which will be used for the calculation of bifurcation carotid angle. For sorting the vertex points to calculate the angle on each vertex, alpha-shapes algorithm is applied along the boundary. Then all the angles on each vertex point along the boundary of vessels are calculated. It is also visually clear that the angle which has the minimum value among all the calculated angles, gives the bifurcation carotid angle for one projected plane. The final carotid angle has calculated and 18 sample datasets are used to test the method.

  5. Human Dignity and Humiliation Studies: A Global Network Advancing Dignity through Dialogue

    ERIC Educational Resources Information Center

    Lindner, Evelin G.; Hartling, Linda M.; Spalthoff, Ulrich

    2011-01-01

    Human rights are universally based on the concept of human dignity. Various international organizations are developing the theoretical, legal, and political framework for human rights. The underlying concept of human dignity is less disputed, but also receives less attention. This shortcoming is addressed by a worldwide group of scholars and…

  6. The Prognostic Significance of Asymptomatic Carotid Bruits in the Elderly

    PubMed Central

    Shorr, Ronald I; Johnson, Karen C; Wan, Jim Y; Sutton-Tyrrell, Kim; Pahor, Marco; Bailey, James E; Applegate, William B

    1998-01-01

    OBJECTIVE To determine the association between asymptomatic carotid bruits and the development of subsequent stroke in older adults with isolated systolic hypertension. DESIGN Retrospective cohort study. SETTING The Systolic Hypertension in the Elderly Program (SHEP), a 5-year randomized trial testing the efficacy of treating systolic hypertension in noninstitutionalized persons aged 60 years or older. From the original 4,736 SHEP participants, we identified a cohort of 4,442 persons who had no prior history of stroke, transient ischemic attack, or myocardial infarction at randomization. MEASUREMENTS AND MAIN RESULTS The end point for this ancillary study was the development of a stroke. The average follow-up was 4.2 years. Carotid bruits were found in 284 (6.4%) of the participants at baseline. Strokes developed in 21 (7.4%) of those with carotid bruits and in 210 (5.0%) of those without carotid bruits. The unadjusted risk of stroke among persons with carotid bruits was 1.53 (95% confidence interval [CI] 0.98, 2.40). Adjusting for age, gender, race, blood pressure, smoking, lipid levels, self-reported aspirin use, and treatment group assignment, the relative risk of stroke among persons with asymptomatic carotid bruits was 1.29 (95% CI 0.80, 2.06). Among SHEP enrollees aged 60 to 69 years, there was a trend (p=.08) toward increased risk (relative risk [RR] 2.05; 95% CI 0.92, 4.68) of subsequent stroke in persons with, compared to those without, carotid bruits. However, among enrollees aged 70 years or over, there was no relation between carotid bruit and subsequent stroke (RR 0.98; 95% CI 0.55, 1.76). In no other subgroup of SHEP enrollees did the presence of carotid bruit independently predict stroke. CONCLUSIONS Although we cannot rule out a small increased risk of stroke associated with bruits in asymptomatic SHEP enrollees aged 60 to 69 years, the utility of carotid bruits as a marker for increased risk of stroke among asymptomatic elderly with isolated

  7. Advancement of a 30K W Solar Electric Propulsion System Capability for NASA Human and Robotic Exploration Missions

    NASA Technical Reports Server (NTRS)

    Smith, Bryan K.; Nazario, Margaret L.; Manzella, David H.

    2012-01-01

    Solar Electric Propulsion has evolved into a demonstrated operational capability performing station keeping for geosynchronous satellites, enabling challenging deep-space science missions, and assisting in the transfer of satellites from an elliptical orbit Geostationary Transfer Orbit (GTO) to a Geostationary Earth Orbit (GEO). Advancing higher power SEP systems will enable numerous future applications for human, robotic, and commercial missions. These missions are enabled by either the increased performance of the SEP system or by the cost reductions when compared to conventional chemical propulsion systems. Higher power SEP systems that provide very high payload for robotic missions also trade favorably for the advancement of human exploration beyond low Earth orbit. Demonstrated reliable systems are required for human space flight and due to their successful present day widespread use and inherent high reliability, SEP systems have progressively become a viable entrant into these future human exploration architectures. NASA studies have identified a 30 kW-class SEP capability as the next appropriate evolutionary step, applicable to wide range of both human and robotic missions. This paper describes the planning options, mission applications, and technology investments for representative 30kW-class SEP mission concepts under consideration by NASA

  8. Increased apolipoprotein E and c-fms gene expression without elevated interleukin 1 or 6 mRNA levels indicates selective activation of macrophage functions in advanced human atheroma.

    PubMed Central

    Salomon, R N; Underwood, R; Doyle, M V; Wang, A; Libby, P

    1992-01-01

    Cells found within atherosclerotic lesions can produce in culture protein mediators that may participate in atherogenesis. To test whether human atheromata actually contain transcripts for certain of these genes, we compared levels of mRNAs in carotid or coronary atheromata and in nonatherosclerotic human vessels by polymerase chain reaction (PCR) amplification of cDNAs reverse-transcribed from RNA. We measured PCR products (generated during exponential amplification) by incorporation of 32P-labeled primers. Levels of interleukin 1 alpha, 1 beta, or 6 mRNAs in plaques and controls did not differ. Compared to uninvolved vessels, plaques did contain higher levels of mRNA encoding platelet-derived growth factor A chain (42 +/- 24 vs. 12 +/- 10 fmol of product; mean +/- SD; n = 8 and 8, respectively; P = 0.007) and B chain (41 +/- 36 vs. 4 +/- 3 fmol of product, n = 14 and 6, respectively; P = 0.024). Atherosclerotic lesions consistently had much higher levels of apolipoprotein E (apoE) mRNA than did control vessels (131 +/- 71 vs. 5 +/- 3 fmol of product; n = 12 and 10, respectively; P less than 0.001). Direct RNA blot analyses confirmed elevated levels of apoE mRNA in plaque extracts. To test whether mononuclear phagocytes might be a source of the apoE mRNA, we studied a selective marker for cells of the monocytic lineage, the c-fms protooncogene, which encodes the receptor for macrophage colony-stimulating factor. Plaques also contained elevated levels of c-fms mRNA (30 +/- 17 vs. 5 +/- 3 fmol of product; n = 10 and 7, respectively; P = 0.002). Immunohistochemical colocalization demonstrated apoE protein in association with macrophages in plaques, whereas nonatherosclerotic vessels showed no immunoreactive apoE. ApoE produced locally in atheroma might modulate the functions of lesional T cells or promote "reverse cholesterol transport" by associating with high density lipoprotein particles, thus targeting them for peripheral uptake. Macrophages within the advanced

  9. Proposed clinical internal carotid artery classification system

    PubMed Central

    Abdulrauf, Saleem I; Ashour, Ahmed M; Marvin, Eric; Coppens, Jeroen; Kang, Brian; Hsieh, Tze Yu Yeh; Nery, Breno; Penanes, Juan R; Alsahlawi, Aysha K; Moore, Shawn; Al-Shaar, Hussam Abou; Kemp, Joanna; Chawla, Kanika; Sujijantarat, Nanthiya; Najeeb, Alaa; Parkar, Nadeem; Shetty, Vilaas; Vafaie, Tina; Antisdel, Jastin; Mikulec, Tony A; Edgell, Randall; Lebovitz, Jonathan; Pierson, Matt; Pires de Aguiar, Paulo Henrique; Buchanan, Paula; Di Cosola, Angela; Stevens, George

    2016-01-01

    Introduction: Numerical classification systems for the internal carotid artery (ICA) are available, but modifications have added confusion to the numerical systems. Furthermore, previous classifications may not be applicable uniformly to microsurgical and endoscopic procedures. The purpose of this study was to develop a clinically useful classification system. Materials and Methods: We performed cadaver dissections of the ICA in 5 heads (10 sides) and evaluated 648 internal carotid arteries with computed tomography angiography. We identified specific anatomic landmarks to define the beginning and end of each ICA segment. Results: The ICA was classified into eight segments based on the cadaver and imaging findings: (1) Cervical segment; (2) cochlear segment (ascending segment of the ICA in the temporal bone) (relation of the start of this segment to the base of the styloid process: Above, 425 sides [80%]; below, 2 sides [0.4%]; at same level, 107 sides [20%]; P < 0.0001) (relation of cochlea to ICA: Posterior, 501 sides [85%]; posteromedial, 84 sides [14%]; P < 0.0001); (3) petrous segment (horizontal segment of ICA in the temporal bone) starting at the crossing of the eustachian tube superolateral to the ICA turn in all 10 samples; (4) Gasserian-Clival segment (ascending segment of ICA in the cavernous sinus) starting at the petrolingual ligament (PLL) (relation to vidian canal on imaging: At same level, 360 sides [63%]; below, 154 sides [27%]; above, 53 sides [9%]; P < 0.0001); in this segment, the ICA projected medially toward the clivus in 275 sides (52%) or parallel to the clivus with no deviation in 256 sides (48%; P < 0.0001); (5) sellar segment (medial loop of ICA in the cavernous sinus) starting at the takeoff of the meningeal hypophyseal trunk (ICA was medial into the sella in 271 cases [46%], lateral without touching the sella in 127 cases [23%], and abutting the sella in 182 cases [31%]; P < 0.0001); (6) sphenoid segment (lateral loop of ICA within the

  10. Proposed clinical internal carotid artery classification system

    PubMed Central

    Abdulrauf, Saleem I; Ashour, Ahmed M; Marvin, Eric; Coppens, Jeroen; Kang, Brian; Hsieh, Tze Yu Yeh; Nery, Breno; Penanes, Juan R; Alsahlawi, Aysha K; Moore, Shawn; Al-Shaar, Hussam Abou; Kemp, Joanna; Chawla, Kanika; Sujijantarat, Nanthiya; Najeeb, Alaa; Parkar, Nadeem; Shetty, Vilaas; Vafaie, Tina; Antisdel, Jastin; Mikulec, Tony A; Edgell, Randall; Lebovitz, Jonathan; Pierson, Matt; Pires de Aguiar, Paulo Henrique; Buchanan, Paula; Di Cosola, Angela; Stevens, George

    2016-01-01

    Introduction: Numerical classification systems for the internal carotid artery (ICA) are available, but modifications have added confusion to the numerical systems. Furthermore, previous classifications may not be applicable uniformly to microsurgical and endoscopic procedures. The purpose of this study was to develop a clinically useful classification system. Materials and Methods: We performed cadaver dissections of the ICA in 5 heads (10 sides) and evaluated 648 internal carotid arteries with computed tomography angiography. We identified specific anatomic landmarks to define the beginning and end of each ICA segment. Results: The ICA was classified into eight segments based on the cadaver and imaging findings: (1) Cervical segment; (2) cochlear segment (ascending segment of the ICA in the temporal bone) (relation of the start of this segment to the base of the styloid process: Above, 425 sides [80%]; below, 2 sides [0.4%]; at same level, 107 sides [20%]; P < 0.0001) (relation of cochlea to ICA: Posterior, 501 sides [85%]; posteromedial, 84 sides [14%]; P < 0.0001); (3) petrous segment (horizontal segment of ICA in the temporal bone) starting at the crossing of the eustachian tube superolateral to the ICA turn in all 10 samples; (4) Gasserian-Clival segment (ascending segment of ICA in the cavernous sinus) starting at the petrolingual ligament (PLL) (relation to vidian canal on imaging: At same level, 360 sides [63%]; below, 154 sides [27%]; above, 53 sides [9%]; P < 0.0001); in this segment, the ICA projected medially toward the clivus in 275 sides (52%) or parallel to the clivus with no deviation in 256 sides (48%; P < 0.0001); (5) sellar segment (medial loop of ICA in the cavernous sinus) starting at the takeoff of the meningeal hypophyseal trunk (ICA was medial into the sella in 271 cases [46%], lateral without touching the sella in 127 cases [23%], and abutting the sella in 182 cases [31%]; P < 0.0001); (6) sphenoid segment (lateral loop of ICA within the

  11. Two Automated Techniques for Carotid Lumen Diameter Measurement: Regional versus Boundary Approaches.

    PubMed

    Araki, Tadashi; Kumar, P Krishna; Suri, Harman S; Ikeda, Nobutaka; Gupta, Ajay; Saba, Luca; Rajan, Jeny; Lavra, Francesco; Sharma, Aditya M; Shafique, Shoaib; Nicolaides, Andrew; Laird, John R; Suri, Jasjit S

    2016-07-01

    The degree of stenosis in the carotid artery can be predicted using automated carotid lumen diameter (LD) measured from B-mode ultrasound images. Systolic velocity-based methods for measurement of LD are subjective. With the advancement of high resolution imaging, image-based methods have started to emerge. However, they require robust image analysis for accurate LD measurement. This paper presents two different algorithms for automated segmentation of the lumen borders in carotid ultrasound images. Both algorithms are modeled as a two stage process. Stage one consists of a global-based model using scale-space framework for the extraction of the region of interest. This stage is common to both algorithms. Stage two is modeled using a local-based strategy that extracts the lumen interfaces. At this stage, the algorithm-1 is modeled as a region-based strategy using a classification framework, whereas the algorithm-2 is modeled as a boundary-based approach that uses the level set framework. Two sets of databases (DB), Japan DB (JDB) (202 patients, 404 images) and Hong Kong DB (HKDB) (50 patients, 300 images) were used in this study. Two trained neuroradiologists performed manual LD tracings. The mean automated LD measured was 6.35 ± 0.95 mm for JDB and 6.20 ± 1.35 mm for HKDB. The precision-of-merit was: 97.4 % and 98.0 % w.r.t to two manual tracings for JDB and 99.7 % and 97.9 % w.r.t to two manual tracings for HKDB. Statistical tests such as ANOVA, Chi-Squared, T-test, and Mann-Whitney test were conducted to show the stability and reliability of the automated techniques. PMID:27299355

  12. A Lumped Parameter Method to Calculate the Effect of Internal Carotid Artery Occlusion on Anterior Cerebral Artery Pressure Waveform

    PubMed Central

    Abdi, M.; Navidbakhsh, M.; Razmkon, A.

    2016-01-01

    Background and Objective Numerical modeling of biological structures would be very helpful tool to analyze hundreds of human body phenomena and also diseases diagnosis. One physiologic phenomenon is blood circulatory system and heart hemodynamic performance that can be simulated by utilizing lumped method. In this study, we can predict hemodynamic behavior of one artery of circulatory system (anterior cerebral artery) when disease such as internal carotid artery occlusion is occurred. Method Pressure-flow simulation is one the leading common approaches for modeling of circulatory system behavior and forecasts of hemodynamic in numerous physiological conditions. In this paper, by using lumped model (electrical analogy), CV system is simulated in MATLAB software (SIMULINK environment). Results The performance of healthy blood circulation and heart is modeled and the obtained results used for further analyses. The stenosis of internal carotid artery at different rates was, then, induced in the circuit and the effects are studied. In stenosis cases, the effects of internal carotid artery occlusion on  left anterior cerebral artery pressure waveform are investigated. Conclusion The findings of this study may have implications not only for understanding the behavior of human biological system at healthy condition but also for diagnosis of diseases in circulatory and cardiovascular system of human body. PMID:27026953

  13. Solitary fibrous tumor surrounding the carotid sheath.

    PubMed

    Gómez-Oliveira, Guillermo; Alvarez-Flores, Modesto; Arribas-García, Ignacio; Martínez-Gimeno, Carlos

    2010-03-01

    Solitary fibrous tumors (SFTs) are rare spindle cell neoplasms that are mostly found arising from the pleura. Although SFTs recently have been reported in other regions, they are rare in the head and neck and have often been misdiagnosed due to their rarity. SFTs are benign in most cases. Clinically, SFTs usually manifest as well-circumscribed, slow-growing, smooth and painless masses. Symptoms are often minimal, although they may include sore throat, difficulty in swallowing, change of voice or trismus. CT-Scan and MRI are the most sensitive imaging procedures used. The treatment of choice is complete surgical excision of the lesion. Because recurrences have been noted up to 30 years after surgery, long-term follow up is mandatory. In this article, we present a case of a Solitary Fibrous Tumor arising in the parapharyngeal space in a 20-year-old man, involving the carotid sheath, treated by surgical excision with no recurrence after 1 year. The clinical presentation, surgical management and pathological findings are described.

  14. Venous Drainage Patterns in Carotid Cavernous Fistulas

    PubMed Central

    Aralasmak, Ayse; Karaali, Kamil; Senol, Utku; Ozdemir, Huseyin; Alkan, Alpay

    2014-01-01

    Purpose. The carotid-cavernous fistula (CCF) is an abnormal arteriovenous communication and its drainage pathways may affect the clinic presentation and change treatment approach. We evaluated drainage patterns of CCFs by digital subtraction angiography (DSA) and categorized drainage pathways according to their types and etiology. Materials and Methods. Venous drainage patterns of 13 CCFs from 10 subjects were studied and categorized as anterior, posterior, superior, inferior, and contralateral on DSA. Drainage patterns were correlated to types and etiology of CCFs. Diagnosis of CCFs was first made by noninvasive imaging techniques. Results. On DSA, traumatic CCFs were usually high flow, direct type while spontaneous CCFs were usually slow flow, indirect type. Bilaterality and mixed types were observed among the indirect spontaneous CCFs. In all CCFs, anterior and inferior drainages were the most common. Contrary to the literature, posterior and superior drainages were noted only in high flow and long standing direct fistulas. Contralateral drainage was not observed in all, supporting plausible compartmentalization of cavernous sinuses. Conclusion. Types, etiology, and duration of the CCFs may affect their drainage patterns. DSA is valuable for categorization of CCFs and verification of drainage patterns. Drainage pathways may affect the clinic presentation and also change treatment approach. PMID:24967298

  15. Th1/Th17 Plasticity Is a Marker of Advanced β Cell Autoimmunity and Impaired Glucose Tolerance in Humans

    PubMed Central

    Reinert-Hartwall, Linnea; Honkanen, Jarno; Salo, Harri M.; Nieminen, Janne K.; Luopajärvi, Kristiina; Härkönen, Taina; Veijola, Riitta; Simell, Olli; Ilonen, Jorma; Peet, Aleksandr; Tillmann, Vallo; Knip, Mikael; Knip, Mikael; Koski, Katriina; Koski, Matti; Härkönen, Taina; Ryhänen, Samppa; Hämäläinen, Anu-Maaria; Ormisson, Anne; Peet, Aleksandr; Tillmann, Vallo; Ulich, Valentina; Kuzmicheva, Elena; Mokurov, Sergei; Markova, Svetlana; Pylova, Svetlana; Isakova, Marina; Shakurova, Elena; Petrov, Vladimir; Dorshakova, Natalya V.; Karapetyan, Tatyana; Varlamova, Tatyana; Ilonen, Jorma; Kiviniemi, Minna; Alnek, Kristi; Janson, Helis; Uibo, Raivo; Salum, Tiit; von Mutius, Erika; Weber, Juliane; Ahlfors, Helena; Kallionpää, Henna; Laajala, Essi; Lahesmaa, Riitta; Lähdesmäki, Harri; Moulder, Robert; Nieminen, Janne; Ruohtula, Terhi; Vaarala, Outi; Honkanen, Hanna; Hyöty, Heikki; Kondrashova, Anita; Oikarinen, Sami; Harmsen, Hermie J. M.; De Goffau, Marcus C.; Welling, Gjalt; Alahuhta, Kirsi; Virtanen, Suvi M.

    2015-01-01

    Upregulation of IL-17 immunity and detrimental effects of IL-17 on human islets have been implicated in human type 1 diabetes. In animal models, the plasticity of Th1/Th17 cells contributes to the development of autoimmune diabetes. In this study, we demonstrate that the upregulation of the IL-17 pathway and Th1/Th17 plasticity in peripheral blood are markers of advanced β cell autoimmunity and impaired β cell function in human type 1 diabetes. Activated Th17 immunity was observed in the late stage of preclinical diabetes in children with β cell autoimmunity and impaired glucose tolerance, but not in children with early β cell autoimmunity. We found an increased ratio of IFN-γ/IL-17 expression in Th17 cells in children with advanced β cell autoimmunity, which correlated with HbA1c and plasma glucose concentrations in an oral glucose tolerance test, and thus impaired β cell function. Low expression of Helios was seen in Th17 cells, suggesting that Th1/Th17 cells are not converted thymus-derived regulatory T cells. Our results suggest that the development of Th1/Th17 plasticity may serve as a biomarker of disease progression from β cell autoantibody positivity to type 1 diabetes. These data in human type 1 diabetes emphasize the role of Th1/Th17 plasticity as a potential contributor to tissue destruction in autoimmune conditions. PMID:25480564

  16. Recent findings from the Human Proteome Project: opening the mass spectrometry toolbox to advance cancer diagnosis, surveillance and treatment.

    PubMed

    Cantor, David I; Nice, Edouard C; Baker, Mark S

    2015-06-01

    The Human Proteome Project stands to eclipse the Human Genome Project in terms of scope, content and interpretation. Its outputs, in conjunction with recent developments across the proteomics community, provide new tools for cancer research with the potential of providing clinically relevant insights into the disease. These collectively may guide the development of future diagnosis, surveillance and treatment strategies. Having established a robust organizational framework within the international community, the Human Proteome Organization and the proteomics community at large have made significant advances in biomarker discovery, detection, molecular imaging and in exploring tumor heterogeneity. Here, the authors discuss some developments in cancer proteomics and how they can be implemented to reduce the global burden of the disease.

  17. Advancing human rights in patient care through strategic litigation: challenging medical confidentiality issues in countries in transition.

    PubMed

    Talbot, Susie

    2013-12-12

    The concept of human rights in patient care offers a framework, relevant to both patients and providers, for identifying and addressing human rights violations within a state's health system. While a range of legal and non-legal mechanisms are available to advance this concept (and, indeed, are generally used to best effect in combination as part of a wider advocacy strategy), this paper considers the use of strategic litigation to hold states to account and encourage broader systemic change. As an illustration of such an approach, this article focuses on the issue of breaches of medical confidentiality-a pervasive problem in certain countries in Eastern Europe and Central Asia, with serious implications for vulnerable or marginalized individuals. This paper presents an overview of the European Court of Human Rights' approach to this topic and discusses the potential for further strategic litigation in Eastern Europe and Central Asia.

  18. Outcome of Carotid Artery Stenting for Radiation-Induced Stenosis

    SciTech Connect

    Dorresteijn, Lucille; Vogels, Oscar; Leeuw, Frank-Erik de; Vos, Jan-Albert; Christiaans, Marleen H.; Ackerstaff, Rob; Kappelle, Arnoud C.

    2010-08-01

    Purpose: Patients who have been irradiated at the neck have an increased risk of symptomatic stenosis of the carotid artery during follow-up. Carotid angioplasty and stenting (CAS) can be a preferable alternative treatment to carotid endarterectomy, which is associated with increased operative risks in these patients. Methods and Materials: We performed a prospective cohort study of 24 previously irradiated patients who underwent CAS for symptomatic carotid stenosis. We assessed periprocedural and nonprocedural events including transient ischemic attack (TIA), nondisabling stroke, disabling stoke, and death. Patency rates were evaluated on duplex ultrasound scans. Restenosis was defined as a stenosis of >50% at the stent location. Results: Periprocedural TIA rate was 8%, and periprocedural stroke (nondisabling) occurred in 4% of patients. After a mean follow-up of 3.3 years (range, 0.3-11.0 years), only one ipsilateral incident event (TIA) had occurred (4%). In 12% of patients, a contralateral incident event was present: one TIA (4%) and two strokes (12%, two disabling strokes). Restenosis was apparent in 17%, 33%, and 42% at 3, 12, and 24 months, respectively, although none of the patients with restenosed vessels became symptomatic. The length of the irradiation to CAS interval proved the only significant risk factor for restenosis. Conclusions: The results of CAS for radiation-induced carotid stenosis are favorable in terms of recurrence of cerebrovascular events at the CAS site.

  19. Pulp Stone, Haemodialysis, End-stage Renal Disease, Carotid Atherosclerosis

    PubMed Central

    Patil, Santosh; Sinha, Nidhi

    2013-01-01

    Objectives: The aim of this study was to determine the relationship between the presence of pulp calcification and carotid artery calcification on the dental panoramic radiographs in End Stage Renal Disease (ESRD) patients who were on haemodialysis. Methods: A total of 112 End Stage Renal Disease (ESRD) patients on who were haemodialysis participated in this study. The periapical and the panoramic radiographs for all the patients were evaluated for the presence or absence of the narrowing of the dental pulps and for pulp stones in the pulp chambers and the pulp canals. The panoramic radiographs were also evaluated to determine the carotid calcification. Results: Carotid calcifications were detected in none of the patients. 84 (74.99%) patients had dental pulp narrowing, and 38 (33.92%) patients had pulp stones. There was no statistical correlation between pulp narrowing and Carotid Artery Calcification (CAC) in the haemodialysis patient group. There was also no statistical correlation between pulp stones and CAC in the haemodialysis patients. Conclusion: However, the incidental finding of CAC on a panoramic radiograph can provide life-saving information for the vascular disease patients, but in the present study, no significant relationship was found between the presence of the pulpal calcification and CAC in the ESRD patients who were on haemodialysis. Therefore, the presence of pulp calcification does not seem to serve as a diagnostic marker for carotid atherosclerosis. PMID:23905147

  20. The distribution of cholinesterases in the cat carotid body.

    PubMed

    Biscoe, T J; Silver, A

    1966-03-01

    1. The distribution of acetyl- and butyrylcholinesterase in the carotid body of the cat has been examined histochemically. Studies were made on normal carotid bodies and on carotid bodies from cats in which certain nerves had been cut some time previously. The nerves sectioned were the sinus nerve, the post-ganglionic sympathetic branch of the superior cervical ganglion or the preganglionic cervical sympathetic trunk.2. It was confirmed that more butyrylcholinesterase than acetylcholinesterase is present. Both enzymes are found in three sites: (i) as strands, (ii) as plexuses, (iii) inside a few cells.3. The distribution is unaffected by cutting the sinus nerve or preganglionic cervical sympathetic nerves. Disorganization and depletion of the cholinesterases in the strands and plexuses occurs when the post-ganglionic branch of the superior cervical ganglion is cut. The cholinesterase in cells is unaffected.4. In carotid bodies in which vessels were filled with red blood cells or in which the vascular bed was injected with carmine-gelatine, it was seen that strands and plexuses are associated with blood vessels, and with blood vessels and cells respectively.5. It is suggested that a cholinergic pathway controlling carotid body blood vessels runs in the post-ganglionic cervical sympathetic.

  1. Delayed presentation of a carotid pseudoaneurysm following penetrating neck trauma

    PubMed Central

    Alfawaz, Abdullah; Li, Xiaoyi; Kénel-Pierre, Stefan; Yang, Jane; Rey, Jorge; Robinson, Handel

    2016-01-01

    Objective: Penetrating carotid trauma in a hemodynamically stable patient invariably presents with a pseudoaneurysm on initial imaging. Although extremely rare, delayed pseudoaneurysm formation has been reported. The purpose of this paper is to define this rare entity and propose a diagnostic and treatment plan. Methods: We present a case of delayed presentation of carotid pseudoaneurysm following penetrating neck trauma. A systematic review of the literature was performed. Results: A 21-year-old male presents to the trauma center after sustaining a gunshot wound to the left upper back resulting in a zone 2 hematoma and pneumothorax. Bullet fragment artifact interfered with computed tomography. Carotid angiogram was normal. The patient was discharged after 3 days. He returned to the Emergency Department 3 months later with a painful pulsatile hematoma. Computed tomography angiogram revealed a 6-cm pseudoaneurysm arising from the proximal left internal carotid artery (ICA). A left common carotid artery (CCA) to ICA bypass with reversed great saphenous vein was performed. The patient’s post-operative course was uneventful, neurologic deficits improved, and he was discharged. Conclusion: Delayed presentation of traumatic pseudoaneurysms has been reported, although usually these cases are iatrogenic access complications in extremities. While endovascular therapies are first line for zone 1 and 3 vascular injuries, management of zone 2 injuries is still controversial. This patient was treated with a bypass due to the need to evacuate the hematoma that was exerting a mass effect in the neck. PMID:27489718

  2. An Experimental and Computational Study of Blunt Carotid Artery Injury

    PubMed Central

    Gayzik, F. Scott; Bostrom, Ola; Örtenwall, Per; Duma, Stefan M.; Stitzel, Joel D.

    2006-01-01

    A carotid artery dissection begins as a tear or defect of the intimal lining of the artery, and can lead to luminal occlusion and ultimately cerebral ischemia. Our aim is to conduct an organ level validation of a finite element model of the carotid artery using an experiment designed to elicit internal layer failure within fluid-filled carotid artery samples. A 2.4-kg beveled guillotine is dropped from three heights (0.3, 0.5 and 0.7 m) onto fluid-filled porcine carotid arteries and resulting damage is recorded. These events are modeled using finite element analysis. Stress, strain and strain rate are correlated to experimental outcome. Internal layer damage is reported in half of the experiments, with damage occurring with 100% frequency at a drop height of 0.7 m. Simulations of this experiment result in maximum principal stress and strain values of 1.43 MPa and 46.2% respectively. The strain level predicted by the model for this impact scenario approaches the strain to intimal failure level for porcine arteries found in the literature. The results of this study represent an important step in validating this finite element carotid artery model at the organ level. PMID:16968627

  3. [Endovascular treatment for cervical carotid artery aneurysm: a case report].

    PubMed

    Hattori, Yasuhiko; Sugiu, Kenji; Hishikawa, Tomohito; Tokunaga, Koji; Takahashi, Kazuya; Date, Isao

    2013-06-01

    We report here a case of cervical carotid artery aneurysm. This 37-year-old male suffered from acute neck swelling when he was taking lunch after physical work. Ultrasonography demonstrated a cervical pseudoaneurysm and a jet flow, which was blowing into the dome from the carotid artery. Angiogram revealed an aneurysm with a diameter of 3 cm at the bifurcation of the common carotid artery. Coil embolization using double-catheter technique was performed and complete occlusion of the aneurysm was obtained without any complications. The patient returned to his normal life. Cervical carotid artery aneurysms are rare and they induce pain by swelling in the neck, hoarseness, swallowing disturbance, hemorrhage, and cerebral ischemia due to embolism. In case of a cervical carotid artery aneurysm, safe and effective treatments are required and endovascular treatment should be considered. Although stent-assisted coil embolization or covered-stent placement were reported as an effective treatment for cervical aneurysms, coil embolization without using a stent was performed in this particular patient who is a young, blue-collar worker because the avoidance of long-term anti-platelet therapy was desirable. Preoperative evaluation is important to select adequate treatment. PMID:23732763

  4. Carotid Artery Stenting Trials: Conduct, Results, Critique, and Current Recommendations

    SciTech Connect

    Macdonald, Sumaira

    2012-02-15

    The carotid stenting trialists have demonstrated persistence and determination in comparing an evolving technique, carotid artery stenting (CAS), against a mature and exacting standard for carotid revascularisation, carotid endarterectomy (CEA). This review focuses on their endeavours. A total of 12 1-on-1 randomised trials comparing CAS and CEA have been reported; 6 of these can be considered major, and 5 of these reflect (in part) current CAS standards of practice and form the basis of this review. At least 18 meta-analyses seeking to compare CAS and CEA exist. These are limited by the quality and heterogeneity of the data informing them (e.g., five trials were stopped prematurely such that they collectively failed to reach recruitment target by >4000 patients). The Carotid Stenting Trialists' Collaboration Publication represents a prespecified meta-analysis of European trials that were sufficiently similar to allow valid conclusions to be drawn; these trials and conclusions will be explored. When the rate of myocardial infarction (MI) is rigorously assessed, CAS and CEA are equivalent for the composite end point of stroke/death and MI, with more minor strokes for CAS and more MIs for CEA. These outcomes have a discrepant impact on quality of life and subsequent mortality. The all-stroke death outcomes for patients <70 years old are equivalent, with more minor strokes occurring in the elderly during CAS than CEA. There are significantly more severe haematomas and cranial nerve injuries after CEA. The influence of experience on outcome cannot be underestimated.

  5. Clinical use of noninvasive evaluation of the carotid artery.

    PubMed

    Persson, A V; O'Leary, D H; Kovacs, A; Dyer, V E

    1980-06-01

    The noninvasive evaluation of carotid artery disease should include a battery of tests that includes one direct and one indirect assessment of the extracranial carotid arteries. The resulting data should be correlated with the clinical findings and the patient's general status so the risks and benefits of carotid endarterectomy may be determined. These studies are usually outpatient procedures and allow one to determine in the office which patients would benefit from carotid surgery and who should be followed serially. Carotid arteriography is reserved for those patients who will be subjected to surgery. In our hands, the combination of CPA, Kartchner-McRae OPG, and Echoflow fulfill these requirements. In a small number of patients the history, physical examination, and noninvasive studies are inconclusive. For most patients, we are able to make decisions as to the best therapy in the office and can discuss risks and benefits with patients and their families with an accuracy of approximately 95 per cent before hospitalization and arteriography are considered.

  6. Gasotransmitter regulation of ion channels: a key step in O2 sensing by the carotid body.

    PubMed

    Prabhakar, Nanduri R; Peers, Chris

    2014-01-01

    Carotid bodies detect hypoxia in arterial blood, translating this stimulus into physiological responses via the CNS. It is long established that ion channels are critical to this process. More recent evidence indicates that gasotransmitters exert powerful influences on O2 sensing by the carotid body. Here, we review current understanding of hypoxia-dependent production of gasotransmitters, how they regulate ion channels in the carotid body, and how this impacts carotid body function.

  7. Carotid artery stenting compared with endarterectomy in patients with symptomatic carotid stenosis (International Carotid Stenting Study): an interim analysis of a randomised controlled trial

    PubMed Central

    2010-01-01

    Summary Background Stents are an alternative treatment to carotid endarterectomy for symptomatic carotid stenosis, but previous trials have not established equivalent safety and efficacy. We compared the safety of carotid artery stenting with that of carotid endarterectomy. Methods The International Carotid Stenting Study (ICSS) is a multicentre, international, randomised controlled trial with blinded adjudication of outcomes. Patients with recently symptomatic carotid artery stenosis were randomly assigned in a 1:1 ratio to receive carotid artery stenting or carotid endarterectomy. Randomisation was by telephone call or fax to a central computerised service and was stratified by centre with minimisation for sex, age, contralateral occlusion, and side of the randomised artery. Patients and investigators were not masked to treatment assignment. Patients were followed up by independent clinicians not directly involved in delivering the randomised treatment. The primary outcome measure of the trial is the 3-year rate of fatal or disabling stroke in any territory, which has not been analysed yet. The main outcome measure for the interim safety analysis was the 120-day rate of stroke, death, or procedural myocardial infarction. Analysis was by intention to treat (ITT). This study is registered, number ISRCTN25337470. Findings The trial enrolled 1713 patients (stenting group, n=855; endarterectomy group, n=858). Two patients in the stenting group and one in the endarterectomy group withdrew immediately after randomisation, and were not included in the ITT analysis. Between randomisation and 120 days, there were 34 (Kaplan-Meier estimate 4·0%) events of disabling stroke or death in the stenting group compared with 27 (3·2%) events in the endarterectomy group (hazard ratio [HR] 1·28, 95% CI 0·77–2·11). The incidence of stroke, death, or procedural myocardial infarction was 8·5% in the stenting group compared with 5·2% in the endarterectomy group (72 vs 44 events

  8. Thirty-Day Outcome Following Carotid Artery Stenting: A 10-Year Experience from a Single Center

    SciTech Connect

    Karkos, Christos D. Karamanos, Dimitrios G.; Papazoglou, Konstantinos O.; Demiropoulos, Filippos P.; Papadimitriou, Dimitrios N.; Gerassimidis, Thomas S.

    2010-02-15

    We aimed to present our experience with carotid angioplasty and stenting (CAS) and to document how the technique evolved over the last decade (1997-2007). A retrospective study of 333 patients (259 men; median age, 69 years) who underwent 336 CAS procedures. Of these, 118 (35%) patients were symptomatic and 164 (49%) lesions involved the left carotid bifurcation. The first 163 patients received a balloon-expandable stent, whereas the remaining 173 received a self-expandable one. Cerebral protection devices were used in the last 84 (25%) procedures. Access was via the femoral artery in all but six cases, in which direct puncture of the common carotid was necessary. The left common carotid originated from the innominate artery in 18 cases (5%). Conversion to open endarterectomy was necessary in two patients due to inability to remove the filter. Perioperative neurological events included stroke in 6 patients (1.8%), transient ischemic attack in 15 (4.5%), and hyperperfusion syndrome in 10 (3.0%). Three patients died during the first 30 days. As a result, the mortality and the combined stroke/death rate were 0.9 and 2.4%, respectively, with no differences between symptomatic and asymptomatic patients. Bradycardia was noted in 48 patients (14%), and hypotension in 45 (13%). Univariate analysis identified hypertension (P = 0.03), hyperlipidemia (P = 0.02), and current or ex-smoking (P = 0.02) as significant risk factors for death/stroke. On multivariate analysis using logistic regression, only hyperlipidemia [odds ratio (OR), 53.90; 95% confidence interval (CI), 4.19-693.47; P = 0.002] and current or ex-smoking (OR, 63.84; 95% CI,: 4.80-848.68; P = 0.001) remained statistically significant. In conclusion, CAS can be performed safely and effectively, with acceptable mortality, stroke/death, and cardiovascular complication rates. Although technological advances (stent design, cerebral protection devices), perioperative pharmacological management, and increasing experience

  9. Left or Right Carotid Endarterectomy in Patients with Atherosclerotic Disease: Ipsilateral Effects on Cognition?

    ERIC Educational Resources Information Center

    Brand, N.; Bossema, E. R.; van Ommen, M.; Moll, F. L.; Ackerstaff, R. G. A.

    2004-01-01

    We evaluated hemispheric functions ipsilateral to the side of carotid endarterectomy (CEA) in patients with a severe stenosis in the left or right carotid artery. Assessments took place 1 day before and 3 months after CEA. Only right-handed males were included. Nineteen patients underwent surgery of the left carotid artery and 17 of the right.…

  10. Bilateral stenosis of carotid siphon in Hutchinson-Gilford progeria syndrome.

    PubMed

    Narazaki, Ryo; Makimura, Mika; Sanefuji, Masafumi; Fukamachi, Shigeru; Akiyoshi, Hidetaka; So, Hidenori; Yamamura, Kenichiro; Doisaki, Sayoko; Kojima, Seiji; Ihara, Kenji; Hara, Toshiro; Ohga, Shouichi

    2013-08-01

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare premature aging disease, caused by a de novo mutation of lamin-A gene, LMNA G608G. Accumulation of abnormal lamin-A (progerin) compromises nuclear membrane integrity and results in the accelerated senescence. Affected patients show a typical feature of birdlike face, alopecia, sclerotic skin, loss of subcutaneous fat, and short stature with advancing years. Neonatal scleroderma is the first presentation, although early diagnosis is challenging. The leading cause of death is cardio-/cerebro-vascular accidents associated with atherosclerosis. However, not all findings may recapitulate the aging process. We herein report a 9-year-old Japanese male with HGPS who developed cerebral infarction. The genetic study of peripheral blood-derived DNA determined a heterozygous c.1824C>T mutation, p.G608G. Telomere length of lymphocytes was normal. Bilateral stenosis of carotid siphons was prominent, while systemic arteriosclerosis was unremarkable assessed by the ankle-brachial index, carotid ultrasound imaging and funduscopic study. HGPS patients have marked loss and functional defects in vascular smooth muscle cells, leading to the vulnerability to circulatory stress. Symmetrical stenosis of siphons might occur as a distinctive cerebral vasculopathy of HGPS, rather than simple vascular senescence. Peripheral blood study on LMNA G608G and telomere length could screen progerias in infancy for early therapeutic intervention.

  11. Carotid Endothelial VCAM-1 Is an Early Marker of Carotid Atherosclerosis and Predicts Coronary Artery Disease in Swine

    PubMed Central

    Masseau, I.; Bowles, D. K.

    2015-01-01

    Objective The aim was to determine if endothelial VCAM-1 (eVCAM-1) expression in the common carotid artery (CCA) would correlate with predictive markers of atherosclerotic disease, would precede reduction of markers of endothelial cell function and would predict coronary artery disease (CAD). Methods and results Carotid arterial segments (bifurcation, proximal and distal CCA) were harvested from 14 and 24 month-old male castrated familial hypercholesterolemic (FH) swine, a model of spontaneous atherosclerosis. Quantification of local expression of eVCAM-1, intimal macrophage accumulation, oxidative stress, intima-media (I/M) ratio, intima-media thickness (IMT), endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (p-eNOS) in selected regions of the carotids revealed a relationship between local inflammation and atheroscle-rotic plaque progression. Importantly, inflammation was not uniform throughout the CCA. Endo-thelial VCAM-1 expression was the greatest at the bifurcation and increased with age. Finally, eV-CAM-1 best estimated the severity of CAD compared to blood levels of glucose, hypercholestero-lemia, carotid IMT, and p-eNOS. Conclusion Our data suggested that eVCAM-1 was closely associated with atherosclerotic plaque progression and preceded impairment of EDD. Thus, this study supported the use of carotid VCAM-1 targeting agents to estimate the severity of CAD. PMID:26702331

  12. Border Detection of Common Carotid Artery Using Hough Transform

    NASA Astrophysics Data System (ADS)

    Koya, Yoshiharu; Nagahara, Yoshihiro

    The arteriosclerosis is on the increase with an aging or change of our living environment. For that reason, diagnosis of the common carotid artery using echocardiogram is doing to take precautions carebropathy. The arteriosclerosis of the common carotid artery is diagnosed using Intima-Media Thickness (IMT) which is obtained from echocardiogram. In order to measure IMT from echocardiogram, it is required to detect a border which is a boundary between vessel tissue layers. The method of border detection requires reproducibility and high accuracy. The conventional methods to detect the border curve depend on differential value of brightness on the common carotid artery. Therefore, we can't extract a good candidate point by influence of a noise. In this paper, we propose the high-accuracy detection method by Hough Transform. About high-accuracy, it realized by attaching importance to high reliable candidate point of border.

  13. Carotid body tumors: advantages of contrast ultrasound investigation.

    PubMed

    Giannoni, Maria F; Irace, Luigi; Vicenzini, Edoardo; Massa, Rita; Gossetti, Bruno; Benedetti-Valentini, Fabrizio

    2009-10-01

    Carotid body tumors are rare neoplasms that have to be considered in the evaluation of all lateral neck mass. Early surgical removal has been recommended to avoid possible cranial nerve injury, the most common perioperative complication. Computed tomography (CT) and magnetic resonance imaging (MRA) angiographies are the preferred pre-operative diagnostic imaging investigations, as well as the 111 In-pentetreotide scintigraphic scan, whereas the standard ultrasound investigations have poor sensitivity in characterizing of the blood flows of the parenchimal structure of the carotid body tumors. We describe a case of a patient with a carotid body tumor assessed with contrast ultrasonography that clearly improved the quality of the standard color Duplex. This technique may represent a non-invasive method, easy to use and to repeat, and able to achieve high diagnostic accuracy.

  14. Addressing Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome in Advanced Practice Nursing Education.

    ERIC Educational Resources Information Center

    Nokes, Kathleen M.; Stein, Gary L.

    1997-01-01

    A survey of 23 advanced practice nursing programs showed only 3 had HIV-specific graduate-level nursing courses. Recommendations were made for HIV-specific courses, integration of HIV content into other courses, use of Centers for Disease Control and Occupational Safety and Health Administration guidelines, and subspecialties in HIV nursing. (SK)

  15. Chronic Interactions Between Carotid Baroreceptors and Chemoreceptors in Obesity Hypertension.

    PubMed

    Lohmeier, Thomas E; Iliescu, Radu; Tudorancea, Ionut; Cazan, Radu; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

    2016-07-01

    Carotid bodies play a critical role in protecting against hypoxemia, and their activation increases sympathetic activity, arterial pressure, and ventilation, responses opposed by acute stimulation of the baroreflex. Although chemoreceptor hypersensitivity is associated with sympathetically mediated hypertension, the mechanisms involved and their significance in the pathogenesis of hypertension remain unclear. We investigated the chronic interactions of these reflexes in dogs with sympathetically mediated, obesity-induced hypertension based on the hypothesis that hypoxemia and tonic activation of carotid chemoreceptors may be associated with obesity. After 5 weeks on a high-fat diet, the animals experienced a 35% to 40% weight gain and increases in arterial pressure from 106±3 to 123±3 mm Hg and respiratory rate from 8±1 to 12±1 breaths/min along with hypoxemia (arterial partial pressure of oxygen=81±3 mm Hg) but eucapnia. During 7 days of carotid baroreflex activation by electric stimulation of the carotid sinus, tachypnea was attenuated, and hypertension was abolished before these variables returned to prestimulation values during a recovery period. After subsequent denervation of the carotid sinus region, respiratory rate decreased transiently in association with further sustained reductions in arterial partial pressure of oxygen (to 65±2 mm Hg) and substantial hypercapnia. Moreover, the severity of hypertension was attenuated from 125±2 to 116±3 mm Hg (45%-50% reduction). These findings suggest that hypoxemia may account for sustained stimulation of peripheral chemoreceptors in obesity and that this activation leads to compensatory increases in ventilation and central sympathetic outflow that contributes to neurogenically mediated hypertension. Furthermore, the excitatory effects of chemoreceptor hyperactivity are abolished by chronic activation of the carotid baroreflex. PMID:27160198

  16. Automated landmarking and geometric characterization of the carotid siphon.

    PubMed

    Bogunović, Hrvoje; Pozo, José María; Cárdenes, Rubén; Villa-Uriol, María Cruz; Blanc, Raphaël; Piotin, Michel; Frangi, Alejandro F

    2012-05-01

    The geometry of the carotid siphon has a large variability between subjects, which has prompted its study as a potential geometric risk factor for the onset of vascular pathologies on and off the internal carotid artery (ICA). In this work, we present a methodology for an objective and extensive geometric characterization of carotid siphon parameterized by a set of anatomical landmarks. We introduce a complete and automated characterization pipeline. Starting from the segmentation of vasculature from angiographic image and its centerline extraction, we first identify ICA by characterizing vessel tree bifurcations and training a support vector machine classifier to detect ICA terminal bifurcation. On ICA centerline curve, we detect anatomical landmarks of carotid siphon by modeling it as a sequence of four bends and selecting their centers and interfaces between them. Bends are detected from the trajectory of the curvature vector expressed in the parallel transport frame of the curve. Finally, using the detected landmarks, we characterize the geometry in two complementary ways. First, with a set of local and global geometric features, known to affect hemodynamics. Second, using large deformation diffeomorphic metric curve mapping (LDDMCM) to quantify pairwise shape similarity. We processed 96 images acquired with 3D rotational angiography. ICA identification had a cross-validation success rate of 99%. Automated landmarking was validated by computing limits of agreement with the reference taken to be the locations of the manually placed landmarks averaged across multiple observers. For all but one landmark, either the bias was not statistically significant or the variability was within 50% of the inter-observer one. The subsequently computed values of geometric features and LDDMCM were commensurate to the ones obtained with manual landmarking. The characterization based on pair-wise LDDMCM proved better in classifying the carotid siphon shape classes than the one

  17. Human Exploration System Test-Bed for Integration and Advancement (HESTIA) Support of Future NASA Deep-Space Missions

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose; Ewert, Michael

    2016-01-01

    The Engineering Directorate at the NASA - Johnson Space Center is outfitting a 20-Foot diameter hypobaric chamber in Building 7 to support future deep-space Environmental Control & Life Support System (ECLSS) research as part of the Human Exploration System Test-bed for Integration and Advancement (HESTIA) Project. This human-rated chamber is the only NASA facility that has the unique experience, chamber geometry, infrastructure, and support systems capable of conducting this research. The chamber was used to support Gemini, Apollo, and SkyLab Missions. More recently, it was used to conduct 30-, 60-, and 90-day human ECLSS closed-loop testing in the 1990s to support the International Space Station and life support technology development. NASA studies show that both planetary surface and deep-space transit crew habitats will be 3-4 story cylindrical structures driven by human occupancy volumetric needs and launch vehicle constraints. The HESTIA facility offers a 3-story, 20-foot diameter habitat consistent with the studies' recommendations. HESTIA operations follow stringent processes by a certified test team that including human testing. Project management, analysis, design, acquisition, fabrication, assembly and certification of facility build-ups are available to support this research. HESTIA offers close proximity to key stakeholders including astronauts, Human Research Program (who direct space human research for the agency), Mission Operations, Safety & Mission Assurance, and Engineering Directorate. The HESTIA chamber can operate at reduced pressure and elevated oxygen environments including those proposed for deep-space exploration. Data acquisition, power, fluids and other facility resources are available to support a wide range of research. Recently completed HESTIA research consisted of unmanned testing of ECLSS technologies. Eventually, the HESTIA research will include humans for extended durations at reduced pressure and elevated oxygen to demonstrate

  18. The Relationship between Carotid Intima-Media Thickness and Carotid Plaque in the Northern Manhattan Study

    PubMed Central

    Rundek, Tatjana; Gardener, Hannah; Della-Morte, David; Dong, Chuanhui; Cabral, Digna; Tiozzo, Eduardo; Roberts, Eugene; Crisby, Milita; Chueng, Kuen; Demmer, Ryan; Elkind, Mitchell S. V.; Sacco, Ralph L.; Desvarieux, Moise

    2015-01-01

    Objective Carotid intima–media thickness (cIMT) and carotid plaque (CP) are proposed biomarkers of subclinical atherosclerosis associated with stroke risk. Whether cIMT and CP are distinct phenotypes or single traits at different stages of atherosclerotic development is unclear. We explored the relationship between these markers in the population-based Northern Manhattan Study. Methods We used high-resolution ultrasound and validated imaging protocols to study the cross-sectional (N=1,788 stroke-free participants) and prospective relationship (N=768 with follow-up scan; mean years between examinations=3.5) between CP and cIMT measured in plaque-free areas. Results The mean age was 66±9 (40% male, 19% black, 17% white, 61% Hispanic). The mean baseline cIMT was 0.92±0.09mm, 0.94±0.09mm among the 58% with prevalent plaque, 0.90±0.08mm among the 42% without prevalent plaque (p<0.0001). Each 0.1mm increase in baseline cIMT was associated with a 1.72-fold increased odds of plaque presence (95%CI=1.50-1.97), increased plaque thickness (effect on the median=0.46mm, p<0.0001), and increased plaque area (effect on the median=3.45mm2, p<0.0001), adjusting for demographics and vascular risk factors. Elevated baseline cIMT was associated with an increased risk of new plaque in any location at follow-up, but after adjusting for demographics and vascular risk factors this association was no longer present. No association was observed in carotid segment-specific analyses. Conclusion Increased cIMT was associated with baseline prevalent plaque but did not predict incident plaque independent of other vascular risk factors. This finding suggests that increased cIMT is not an independent predictor of plaque development although these atherosclerotic phenotypes often coexist and share some common vascular determinants. PMID:26071659

  19. Lateralization of expression of neural sympathetic activity to the vessels and effects of carotid baroreceptor stimulation

    PubMed Central

    Diedrich, André; Porta, Alberto; Barbic, Franca; Brychta, Robert J.; Bonizzi, Pietro; Diedrich, Laura; Cerutti, Sergio; Robertson, David; Furlan, Raffaello

    2009-01-01

    Human studies suggest that cardiovascular neural sympathetic control is predominantly modulated by the right cerebral hemisphere. It is unknown whether post-ganglionic sympathetic activity [muscle sympathetic nerve activity (MSNA)] shows any functional asymmetry. Eight right-handed volunteers (3 women and 5 men, 32 ± 2 yr of age) underwent ECG, beat-by-beat blood pressure, respiratory activity, and simultaneous right and left MSNA recordings during spontaneous and controlled breathing (CB, 15 breaths/min, 0.25 Hz). Dynamic carotid baroreceptor stimulation was obtained by 0.1-Hz sinusoidal suction, from 0 to −50 mmHg, randomly applied to the right, left, and combined right and left sides of the neck during CB. Laterality was assessed by changes in the MSNA burst rate (in bursts/min, and bursts/100 beats), strength [amplitude (A) and area (AA)], and the oscillatory component at 0.1 Hz during baroreceptor stimulation. Amplitude parameters were normalized by CB burst mean amplitude and area of the same side. At rest, the right and left MSNA burst rate and total MSNA activity were similar. Conversely, the right MSNA normalized burst AN (1.36 ± 0.18) and AAN (1.31 ± 0.16) were larger than the left MSNA AN (1.04 ± 0.09) and AAN (1.02 ± 0.08). Unilateral and bilateral carotid baroreflex stimulation abolished the right prevalence of AN and AAN. In conclusion, the right lateralization of sympathetic activity to the vessels is indicated by normalized burst strength parameters of bilateral MSNA recordings at rest during spontaneous breathing. Carotid baroreceptor stimulation disrupted such expression of MSNA lateralization possibly by disturbing the synchronizing action of right cerebral hemisphere. PMID:19363133

  20. Correlation of dental pulp stones, carotid artery and renal calcifications using digital panoramic radiography and ultrasonography

    PubMed Central

    Yeluri, Garima; Kumar, C. Anand; Raghav, Namita

    2015-01-01

    Background: The human tissues continuously undergo modification as deposition of calcium (CA) salts either in an organized or disorganized pattern. The latter pattern usually occurs in the soft tissues such as in arteries, brain, kidneys, lungs, and dental pulp. The purpose of this study is to evaluate the presence of pulp calcification and carotid artery calcification (CDC) as a marker for renal calcification and altered serum biomarkers such as serum CA, phosphorus (P), and alkaline phosphatase (ALP). Materials and Methods: Digital panoramic radiographs of 50 patients with the presence of pulp stones and suspected CAC were subjected to carotid artery and renal ultrasonography (USG) examination for the presence of vascular calcification and also to evaluate the alterations in serum CA, P, and ALP levels. Data were analyzed statistically using Chi-square test. Results: Panoramic radiographs of 50 patients showed 88.28% of teeth with the presence of pulp stones stones and 91% carotid arteries with calcification. The sensitivity of panoramic radiograph was greater than that of USG (93.67%), but the specificity of USG was more than the panoramic radiograph (44.44%) in detecting CAC. The prevalence rate of renal calcification on USG was 92%. The statistical difference between the patients with or without alteration in serum Ca levels was not significant (χ2 = 0.581 and P = 0.446). On comparison of serum P and ALP, the difference was found to be statistically significant. Conclusion: Presence of pulp stones and CAC's on panoramic radiograph have remarkably proved to establish the chances of renal artery calcification associated with alterations in serum CA levels. PMID:26604565

  1. Impact of palbociclib combinations on treatment of advanced estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer

    PubMed Central

    Boér, Katalin

    2016-01-01

    Breast cancer is a heterogeneous disease with multiple subgroups based on clinical and molecular characteristics. For the largest subgroup of breast cancers, hormone receptor-positive/human epidermal growth factor 2 (HER2)-negative tumors, hormone treatment is the mainstay of therapy and is likely to result in significant improvement in disease outcomes. However, some of these cancers demonstrate de novo or acquired resistance to endocrine therapy. Despite intensive research to develop new strategies to enhance the efficacy of currently available treatment options for hormone receptor-positive breast cancer, progress has been slow, and there were few advances for a period of 10 years. In 2012, a new molecularly targeted therapeutic strategy, inhibition of mammalian target of rapamycin with everolimus, was introduced into clinical practice. Everolimus, in combination with a steroidal aromatase inhibitor, exemestane, resulted in an increase in progression-free survival, but not overall survival in patients with estrogen receptor (ER)+ve advanced disease who had progressed on hormone therapy. In 2015, the first cyclin-dependent kinases 4/6 (CDK4/6) inhibitor, palbociclib, received accelerated US Food and Drug Administration approval for use in combination with letrozole for the treatment of postmenopausal ER+ve/HER2−ve advanced breast cancer as initial, endocrine-based therapy. The addition of palbociclib to endocrine therapy resulted in longer progression-free survival than letrozole alone. One year later, palbociclib received a new indication, use in combination with fulvestrant, in both premenopausal and postmenopausal females with advanced breast cancer of the same subtype with disease progression following endocrine therapy. Adding palbociclib to fulvestrant resulted in a significantly increased median progression-free survival compared to fulvestrant monotherapy. These new combination regimens of palbociclib with endocrine agents represent an important

  2. [Correlation of some biochemical and coagulological parameters in carotid atherosclerosis].

    PubMed

    Akhvlediani, M V; Vorob'eva, E O; Emukhvari, M G; Sharashidze, N A; Kupreishvili, S B

    2009-11-01

    It has been established positive correlation of the degree of stenosis and intima-media thickness of carotid arteries with the following biochemical parameters: total cholesterol, LDL cholesterol, Apo-B, Lp(a), triglycerides, hs-C-reactive protein(CRP), interleukines (IL-1beta and IL-6), fibrinogen, D-dimers. Negative correlation was stated with respect to HDL cholesterol, Apo-A-1, protein C. Relation between the parameters of the blood lipid spectre, proteins and mediators of inflammation as well as those of hemostasis enables us to approach pathophysiological mechanisms of carotid atherosclerosis, define the processes of inflammation and atherosclerosis.

  3. Tissue Characterization on Common Carotid Artery using AR Model

    NASA Astrophysics Data System (ADS)

    Koya, Yoshiharu; Mizoshiri, Isao

    This study uses one image with a echocardiography and detects arteriosclerosis on the common carotid artery by tissue characterization. The conventional methods are measurement of thickness on the vessel wall or stiffness on the common carotid artery. However, they need frames of several beats and great calculation times. But, we detect the arteriosclerosis with only one image. Our method estimate the grade of arteriosclerosis by AR model parameters fitted to the texture on the lumen-intima wall. Experimental results show the validity of the proposed method.

  4. Injury of the peripheral cranial nerves during carotid endarterectomy.

    PubMed

    Theodotou, B; Mahaley, M S

    1985-01-01

    The incidence of local nerve injury among 192 consecutive carotid endarterectomies in 162 patients between 1977-1983 was determined from review of the medical records. Two facial nerve, 5 hypoglossal nerve, and 2 vagus nerve injuries were discovered for a total incidence of 4.7%. Only the 2 facial nerve injuries failed to improve over 2 years. Followup ranged from 1 to 60 months in this group of patients. Careful attention to details of tissue dissection at surgery should lower the incidence of nerve injury during carotid endarterectomy. PMID:4049454

  5. Heuber Maneuver in Evaluation of Direct Carotid-Cavernous Fistula

    PubMed Central

    Rajagopal, Rengarajan; Mehta, Neeraj; Saran, Sonal; Khera, Pushpinder S.

    2016-01-01

    Summary Carotid-cavernous fistulas are abnormal communications between the carotid system and the cavernous sinus. Elevated venous pressure produces congestion in the orbit with resultant transudation of fluid and increased intraocular pressure, thereby leading to secondary glaucoma which may result in visual loss. Immediate treatment is hence, warranted in these cases. The planning of endovascular management is dependent on many parameters, the most important of which are the size and location of the fistula. Since these are high-flow fistulas, assessment requires certain manoeuvers. Heuber manoeuver is one of the manoeuvers used to demonstrate the size of the fistula. PMID:27781074

  6. Anti‐Inflammatory Immune Skewing Is Atheroprotective: Apoe−/−FcγRIIb−/− Mice Develop Fibrous Carotid Plaques

    PubMed Central

    Harmon, Erin Y.; Fronhofer, Van; Keller, Rebecca S.; Feustel, Paul J.; Zhu, Xinmei; Xu, Hao; Avram, Dorina; Jones, David M.; Nagarajan, Shanmugam; Lennartz, Michelle R.

    2014-01-01

    Background Stroke, caused by carotid plaque rupture, is a major cause of death in the United States. Whereas vulnerable human plaques have higher Fc receptor (FcγR) expression than their stable counterparts, how FcγR expression impacts plaque histology is unknown. We investigated the role of FcγRIIb in carotid plaque development and stability in apolipoprotein (Apo)e−/− and Apoe−/−FcγRIIb−/− double knockout (DKO) animals. Methods and Results Plaques were induced by implantation of a shear stress‐modifying cast around the carotid artery. Plaque length and stenosis were followed longitudinally using ultrasound biomicroscopy. Immune status was determined by flow cytometry, cytokine release, immunoglobulin G concentration and analysis of macrophage polarization both in plaques and in vitro. Surprisingly, DKO animals had lower plaque burden in both carotid artery and descending aorta. Plaques from Apoe−/− mice were foam‐cell rich and resembled vulnerable human specimens, whereas those from DKO mice were fibrous and histologically stable. Plaques from DKO animals expressed higher arginase 1 (Arg‐1) and lower inducible nitric oxide synthase (iNOS), indicating the presence of M2 macrophages. Analysis of blood and cervical lymph nodes revealed higher interleukin (IL)‐10, immune complexes, and regulatory T cells (Tregs) and lower IL‐12, IL‐1β, and tumor necrosis factor alpha (TNF‐α) in DKO mice. Similarly, in vitro stimulation produced higher IL‐10 and Arg‐1 and lower iNOS, IL‐1β, and TNF‐α in DKO versus Apoe−/− macrophages. These results define a systemic anti‐inflammatory phenotype. Conclusions We hypothesized that removal of FcγRIIb would exacerbate atherosclerosis and generate unstable plaques. However, we found that deletion of FcγRIIb on a congenic C57BL/6 background induces an anti‐inflammatory Treg/M2 polarization that is atheroprotective. PMID:25516435

  7. A cohort study of duplex Doppler examinations of the carotid artery in primary open angle glaucoma

    PubMed Central

    Marmion, Vincent J; Aldoori, Munther I; Woodcock, John P

    2014-01-01

    Objectives To explore the possibility of pathological change in the common carotid artery at the bifurcation and in the internal carotid artery beyond the bifurcation which could contribute to a reduced diastolic pressure as observed in primary open angle glaucoma. Design Duplex ultrasonic examinations of carotid bifurcations were conducted on 80 patients. Carotid artery defects were allocated into three types: no demonstrable flow defects, internal carotid artery abnormalities and disease in the carotid bulb. Setting Bristol Royal Infirmary Vascular Laboratory. Participants Eighty patients (mean age 69.6 years) providing a total of 160 sides to the analysis. Main outcome measures An estimated central retinal artery pressure, intraocular pressure and field loss were recorded for each side measured. Results Doppler investigations revealed significant levels of pathological change in the internal carotid distinct from changes at the carotid bulb. The disease revealed in the internal carotid artery was significantly associated with intraocular pressure (p = 0.032), with an effect small to medium in magnitude. The Q2 measure, derived from mean arterial pressure and intraocular pressure, was also substantively associated with disease in the internal carotid artery. Both intraocular pressure and the Q2 measure effectively discriminated between groups, with field loss providing rather less discriminating capability. There was a strong trend towards a higher intraocular pressures and a greater visual field loss with internal carotid artery disease. Conclusions Pathological changes in the extra cranial carotid artery in primary open angle glaucoma exceed those in the arteries classified as normal. The presence of disease specifically in the internal carotid artery emphasised the need for a mechanism for the evaluation of the internal carotid apart from the carotid bulb. A basis for clarifying the presence of an ischaemic zone is proposed. PMID:25289141

  8. Advances in Electronic-Nose Technologies for the Detection of Volatile Biomarker Metabolites in the Human Breath

    PubMed Central

    Wilson, Alphus D.

    2015-01-01

    Recent advancements in the use of electronic-nose (e-nose) devices to analyze human breath profiles for the presence of specific volatile metabolites, known as biomarkers or chemical bio-indicators of specific human diseases, metabolic disorders and the overall health status of individuals, are providing the potential for new noninvasive tools and techniques useful to point-of-care clinical disease diagnoses. This exciting new area of electronic disease detection and diagnosis promises to yield much faster and earlier detection of human diseases and disorders, allowing earlier, more effective treatments, resulting in more rapid patient recovery from various afflictions. E-nose devices are particularly suited for the field of disease diagnostics, because they are sensitive to a wide range of volatile organic compounds (VOCs) and can effectively distinguish between different complex gaseous mixtures via analysis of electronic aroma sensor-array output profiles of volatile metabolites present in the human breath. This review provides a summary of some recent developments of electronic-nose technologies, particularly involving breath analysis, with the potential for providing many new diagnostic applications for the detection of specific human diseases associated with different organs in the body, detectable from e-nose analyses of aberrant disease-associated VOCs present in air expired from the lungs. PMID:25738426

  9. Diabetes mellitus--advances and challenges in human β-cell proliferation.

    PubMed

    Wang, Peng; Fiaschi-Taesch, Nathalie M; Vasavada, Rupangi C; Scott, Donald K; García-Ocaña, Adolfo; Stewart, Andrew F

    2015-04-01

    The treatment of diabetes mellitus represents one of the greatest medical challenges of our era. Diabetes results from a deficiency or functional impairment of insulin-producing β cells, alone or in combination with insulin resistance. It logically follows that the replacement or regeneration of β cells should reverse the progression of diabetes and, indeed, this seems to be the case in humans and rodents. This concept has prompted attempts in many laboratories to create new human β cells using stem-cell strategies to transdifferentiate or reprogramme non-β cells into β cells or to discover small molecules or other compounds that can induce proliferation of human β cells. This latter approach has shown promise, but has also proven particularly challenging to implement. In this Review, we discuss the physiology of normal human β-cell replication, the molecular mechanisms that regulate the cell cycle in human β cells, the upstream intracellular signalling pathways that connect them to cell surface receptors on β cells, the epigenetic mechanisms that control human β-cell proliferation and unbiased approaches for discovering novel molecules that can drive human β-cell proliferation. Finally, we discuss the potential and challenges of implementing strategies that replace or regenerate β cells.

  10. Cerebral hemodynamics after contralateral carotid endarterectomy in patients with symptomatic and asymptomatic carotid occlusion: a 10-year follow-up.

    PubMed

    Baracchini, Claudio; Meneghetti, Giorgio; Manara, Renzo; Ermani, Mario; Ballotta, Enzo

    2006-07-01

    We sought to investigate whether carotid endarterectomy (CEA) can achieve long-term cerebral hemodynamic improvement and reduce recurrence of cerebral ischemic events in symptomatic and asymptomatic patients with severe (>70%) carotid artery stenosis contralateral to carotid occlusion (CO). Thirty-nine patients with severe carotid lesion contralateral to CO were studied before (1 day) and after CEA (at 7 days, 1, 3 and 6 months, and then yearly thereafter). Collateral flow and cerebral vasomotor reactivity (VMR) were assessed by transcranial Doppler sonography (TCD). A total of 32 unoperated patients with severe carotid lesion contralateral to CO, who were comparable with respect to age and sex, served as a control group. The average period of TCD follow-up was 10 years and was obtained in all patients; during this period, major clinical events (stroke, acute myocardial infarction and death) were also recorded. The proportion of patients with collateral flow via the anterior communicating artery increased significantly from 61.5% before to 89.7% after CEA (P = 0.01). Cerebral VMR ipsilateral to CO improved in 85.7% of patients (30 of 35) within 30 days of CEA, and in all patients within 90 days. No significant spontaneous VMR recovery was recorded in the control group. After the initial recovery, no significant change in VMR was observed in the surgical group or the control group during the follow-up. In conclusion, in patients with severe carotid stenosis, CEA contralateral to symptomatic and asymptomatic CO determines a durable cerebral hemodynamic improvement not only on the side of the CEA but also on the contralateral side, with no difference between symptomatic and asymptomatic patients.

  11. Treatment of a ballistic wound of the common carotid artery revealed by a spontaneous carotid-jugular fistula.

    PubMed

    Mlynski, Amélie; Mocellin, Nicolas; Imperato, Marc; Molimard, Benoît; Bordier, Emmanuel; Menguy, Paul; Baranger, Bernard

    2011-02-01

    The case reported is of a 30-year-old patient with a left internal carotid-jugular fistula secondary to the explosion of an improvised explosive device during the Afghan war. Carotid resection with arterial bypass using a venous allograft and internal jugular ligation were performed by left cervicotomy associated with sternotomy at a specialized center. The management of cervical arteriovenous fistulas that occur as a result of penetrating trauma faced during the war must be considered and it should be noted that, on battlefields, treatment is not always performed in specialized units. PMID:21183314

  12. Human Engineering Operations and Habitability Assessment: A Process for Advanced Life Support Ground Facility Testbeds

    NASA Technical Reports Server (NTRS)

    Connolly, Janis H.; Arch, M.; Elfezouaty, Eileen Schultz; Novak, Jennifer Blume; Bond, Robert L. (Technical Monitor)

    1999-01-01

    Design and Human Engineering (HE) processes strive to ensure that the human-machine interface is designed for optimal performance throughout the system life cycle. Each component can be tested and assessed independently to assure optimal performance, but it is not until full integration that the system and the inherent interactions between the system components can be assessed as a whole. HE processes (which are defining/app lying requirements for human interaction with missions/systems) are included in space flight activities, but also need to be included in ground activities and specifically, ground facility testbeds such as Bio-Plex. A unique aspect of the Bio-Plex Facility is the integral issue of Habitability which includes qualities of the environment that allow humans to work and live. HE is a process by which Habitability and system performance can be assessed.

  13. Admixed human embryos and stem cells: legislative, ethical and scientific advances.

    PubMed

    Bahadur, G; Iqbal, M; Malik, S; Sanyal, A; Wafa, R; Noble, R

    2008-01-01

    This paper examines the regulatory framework currently governing the creation of animal-human hybrids and chimera embryos in stem cell research, and some of the ethical implications of such research. It discusses the findings of a recent government select committee that considered the topic. It considers the debate around the precise definition of a human embryo, and whether such hybrids therefore fall within the remit of the Human Fertilisation and Embryology Authority. It outlines the advantages of such hybrids, in lessening the need for human egg donors, as well as the moral objections to species boundary violation. It calls for an examination of the scientific benefits of such research to inform debate on the question, and argues for the need to take genuine account of the public's views on this matter.

  14. [Advances in humans and animals opportunistic pathogens from environment infecting plants by crossing kingdoms].

    PubMed

    Huang, Min; Wu, Yixin; He, Pengfei

    2016-02-01

    Some pathogenic microorganisms ubiquitous in the environment could cross kingdoms to infect diverse hosts. Several cross-kingdom human pathogens were summarized in this paper, including Serratia marcescens, Enterobacter cloacae and Pseudomonas aeuriginosa. They are ubiquitous in the nature and could cause plant diseases using the same or different infection strategies with which they infect humans and broaden host range. Among these bacteria, Klebsiella pneumoniae causes top rot disease of maize in the nature, revealing some plants in the environment could serve as a reservoir of various pathogens which might infect animals and probably humans when conditions are favorable, and even potentially harm food. Research on these cross-kingdom pathogens may play a very important role in the epidemiology of human, animal and plant diseases and be a hot topic in environment science. PMID:27373067

  15. Wavelet-based neural network analysis of internal carotid arterial Doppler signals.

    PubMed

    Ubeyli, Elif Derya; Güler, Inan

    2006-06-01

    In this study, internal carotid arterial Doppler signals recorded from 130 subjects, where 45 of them suffered from internal carotid artery stenosis, 44 of them suffered from internal carotid artery occlusion and the rest of them were healthy subjects, were classified using wavelet-based neural network. Wavelet-based neural network model, employing the multilayer perceptron, was used for analysis of the internal carotid arterial Doppler signals. Multi-layer perceptron neural network (MLPNN) trained with the Levenberg-Marquardt algorithm was used to detect stenosis and occlusion in internal carotid arteries. In order to determine the MLPNN inputs, spectral analysis of the internal carotid arterial Doppler signals was performed using wavelet transform (WT). The MLPNN was trained, cross validated, and tested with training, cross validation, and testing sets, respectively. All these data sets were obtained from internal carotid arteries of healthy subjects, subjects suffering from internal carotid artery stenosis and occlusion. The correct classification rate was 96% for healthy subjects, 96.15% for subjects having internal carotid artery stenosis and 96.30% for subjects having internal carotid artery occlusion. The classification results showed that the MLPNN trained with the Levenberg-Marquardt algorithm was effective to detect internal carotid artery stenosis and occlusion. PMID:16848135

  16. Reflections by contrarians on the post-CREST evaluation of carotid stenting for stroke prevention.

    PubMed

    Barnett, Henry J M; Pelz, David M; Lownie, Stephen P

    2010-12-01

    Carotid angioplasty and stenting has become a popular alternative to carotid endarterectomy for the treatment of carotid stenosis in stroke. Evidence from early randomized controlled trials comparing these interventions revealed mixed results. The largest such trial, the Carotid Revascularization Endarterectomy vs. Stenting Trial recently showed equivalence of the procedures in a mixed cohort of both symptomatic and asymptomatic patients. These results have been heralded in North America as definitively demonstrating the safety and efficacy of carotid angioplasty and stenting, making it an attractive alternative to carotid endarterectomy. It is therefore probable that many more asymptomatic patients will be subjected to Carotid angioplasty and stenting, perceived by many to be less invasive than carotid endarterectomy. The authors argue that the design of Carotid Revascularization Endarterectomy vs. Stenting Trial was flawed by the mixture of two dissimilar patient groups, thus violating the principle of ceteris paribus, essential for the validity of a randomized controlled trials. The evidence for any invasive treatment of asymptomatic carotid disease is weak, with recent data favouring purely medical management. The authors believe that carotid angioplasty and stenting in asymptomatic patients should cease until better evidence is available. PMID:21050401

  17. Cranial nerve palsies in spontaneous carotid artery dissection.

    PubMed Central

    Sturzenegger, M; Huber, P

    1993-01-01

    Two patients had isolated unilateral cranial nerve palsies due to spontaneous internal carotid artery (ICA) dissection without ischaemic cerebral involvement. One had acute glossopharyngeal and vagal, the other isolated hypoglossal nerve palsy. Reviewing all reported cases of angiographically confirmed ICA dissection in the literature, 36 additional cases with unequivocal ipsilateral cranial nerve palsies were analysed. While an isolated palsy of the IXth and Xth has not been reported previously, palsies of the XIIth nerve or the IXth to XIIth nerves were most frequently found. In these patients, lower cranial nerve palsies are probably the result of compression by an enlarging ICA due to mural haematoma. Symptoms and signs indicative of carotid dissection were concurrently present only in some reported cases. This raises the question of unrecognised carotid dissection as a cause of isolated cranial nerve palsies. When the dissection occurs in the subadventitial layer without relevant narrowing of the arterial lumen and when an aneurysm is thrombosed, angiography does not reliably yield the diagnosis. Therefore, carotid dissection might have been underestimated as a cause of isolated lower cranial nerve palsies before the advent of MRI. MRI demonstrates directly the extension of the wall haematoma in the axial and longitudinal planes. Some arteriopathies such as fibromuscular dysplasia and tortuosity make a vessel predisposed to dissection. Images PMID:8229030

  18. A Parallel Lattice Boltzmann Model of a Carotid Artery

    NASA Astrophysics Data System (ADS)

    Boyd, J.; Ryan, S. J.; Buick, J. M.

    2008-11-01

    A parallel implementation of the lattice Boltzmann model is considered for a three dimensional model of the carotid artery. The computational method and its parallel implementation are described. The performance of the parallel implementation on a Beowulf cluster is presented, as are preliminary hemodynamic results.

  19. Acute Carotid Artery Stent Thrombosis Due to Dual Antiplatelet Resistance

    SciTech Connect

    Köklü, Erkan Arslan, Şakir; Yüksel, İsa Öner; Bayar, Nermin; Koç, Pınar

    2015-08-15

    Carotid artery stenting (CAS) is a revascularization modality that is an alternative to carotid endarterectomy. The efficacy of CAS in primary and secondary prevention from ischemic stroke has been demonstrated in various trials. Acute thrombosis of CAS is a rare complication that can lead to dramatic and catastrophic consequences. We discuss a case of acute CAS thrombosis in a patient who had previously undergone successful CAS. CAS was performed in a 73-year-old man who had had dysarthria lasting 2 weeks with 95 % stenosis in his left internal carotid artery. An acute cerebrovascular event resulting in right-sided hemiplegia developed 24 h after the procedure. Computed tomographic carotid angiography revealed complete occlusion of the stent with thrombus. The cause of stent thrombosis was thought to be antiaggregant resistance to both acetylsalicylic acid and clopidogrel. The most important cause of acute CAS thrombosis is inadequate or ineffective antiaggregant therapy. Evaluating patients who are candidates for CAS for acetylsalicylic acid and clopidogrel resistance may preclude this complication.

  20. [Revascularization of the carotid and vertebral arteries in the elderly].

    PubMed

    Illuminati, G; Bezzi, M; D'Urso, A; Giacobbi, D; Ceccanei, G; Vietri, F

    2004-01-01

    From January 1994 to July 2004, 323 patients underwent 348 revascularization of carotid bifurcation for atherosclerotic stenoses. Eighty eight patients (group A) were 75 year-old or older, whereas 235 (group B) were younger than 75 years. Postoperative mortality/neurologic morbidity rate was 1% in group A, and 1.4% in group B. At 5 years, patency and freedom from symptoms/stroke were, respectively, 91% and 92% in group A, and 89% and 91% in group B. None of these differences was statistically significant. In the same time period, 26 internal carotid arteries were revascularized in 24 patients, 75 or more aged, for a symptomatic kinking. Postoperative mortality/morbidity rate was absent, whereas, at 5 years, patency and freedom from symptoms/stroke were, respectively, 88% and 92%. Twelve vertebral arteries were revascularized in 12 patients, 75 or more aged, for invalidating symptoms of vertebrobasilar insufficiency. Postoperative mortality/neurologic morbidity rate was absent. In one case postoperative recurrence of symptoms occurred, despite a patent revascularization. Patency and freedom from symptoms/stroke were 84% and 75%, at 5 years. Revascularization of carotid and vertebral arteries in the elderly can be accomplished with good results, superposable to those of standard revascularization of carotid bifurcation in a younger patients' population.

  1. Aortic Baroreceptors Display Higher Mechanosensitivity than Carotid Baroreceptors

    PubMed Central

    Lau, Eva On-Chai; Lo, Chun-Yin; Yao, Yifei; Mak, Arthur Fuk-Tat; Jiang, Liwen; Huang, Yu; Yao, Xiaoqiang

    2016-01-01

    Arterial baroreceptors are mechanical sensors that detect blood pressure changes. It has long been suggested that the two arterial baroreceptors, aortic and carotid baroreceptors, have different pressure sensitivities. However, there is no consensus as to which of the arterial baroreceptors are more sensitive to changes in blood pressure. In the present study, we employed independent methods to compare the pressure sensitivity of the two arterial baroreceptors. Firstly, pressure-activated action potential firing was measured by whole-cell current clamp with a high-speed pressure clamp system in primary cultured baroreceptor neurons. The results show that aortic depressor neurons possessed a higher percentage of mechano-sensitive neurons. Furthermore, aortic baroreceptor neurons show a lower pressure threshold than that of carotid baroreceptor neurons. Secondly, uniaxial stretching of baroreceptor neurons, that mimics the forces exerted on blood vessels, elicited a larger increase in intracellular Ca2+ rise in aortic baroreceptor neurons than in carotid baroreceptor neurons. Thirdly, the pressure-induced action potential firing in the aortic depressor nerve recorded in vivo was also higher. The present study therefore provides for a basic physiological understanding on the pressure sensitivity of the two baroreceptor neurons and suggests that aortic baroreceptors have a higher pressure sensitivity than carotid baroreceptors. PMID:27630578

  2. Aortic Baroreceptors Display Higher Mechanosensitivity than Carotid Baroreceptors.

    PubMed

    Lau, Eva On-Chai; Lo, Chun-Yin; Yao, Yifei; Mak, Arthur Fuk-Tat; Jiang, Liwen; Huang, Yu; Yao, Xiaoqiang

    2016-01-01

    Arterial baroreceptors are mechanical sensors that detect blood pressure changes. It has long been suggested that the two arterial baroreceptors, aortic and carotid baroreceptors, have different pressure sensitivities. However, there is no consensus as to which of the arterial baroreceptors are more sensitive to changes in blood pressure. In the present study, we employed independent methods to compare the pressure sensitivity of the two arterial baroreceptors. Firstly, pressure-activated action potential firing was measured by whole-cell current clamp with a high-speed pressure clamp system in primary cultured baroreceptor neurons. The results show that aortic depressor neurons possessed a higher percentage of mechano-sensitive neurons. Furthermore, aortic baroreceptor neurons show a lower pressure threshold than that of carotid baroreceptor neurons. Secondly, uniaxial stretching of baroreceptor neurons, that mimics the forces exerted on blood vessels, elicited a larger increase in intracellular Ca(2+) rise in aortic baroreceptor neurons than in carotid baroreceptor neurons. Thirdly, the pressure-induced action potential firing in the aortic depressor nerve recorded in vivo was also higher. The present study therefore provides for a basic physiological understanding on the pressure sensitivity of the two baroreceptor neurons and suggests that aortic baroreceptors have a higher pressure sensitivity than carotid baroreceptors. PMID:27630578

  3. Unusual presentation of traumatic extracranial internal carotid artery aneurysm.

    PubMed

    Bradbury, P G; Lambert, C D

    1978-07-01

    A young man presented with apparent transient ischemic attacks following a motorcycle accident in which he sustained minor injuries only. Computerized axial tomography demonstrated a small right frontal infarct, and angiography revealed an aneurysm of the right internal carotid artery in its extracranial course. This was thought to be traumatic in origin.

  4. Differential modulation by extracellular ATP of carotid chemosensory responses.

    PubMed

    Spergel, D; Lahiri, S

    1993-06-01

    The possibility that the carotid body has ATP surface receptors that mediate O2 chemoreception was tested. To distinguish between the event(s) initiating chemoreception and those at the neurotransmitter level, we also tested the chemosensory response to nicotine before and after ATP administration. Carotid bodies from cats anesthetized with pentobarbital sodium were perfused and superfused in vitro with modified Tyrode solution (PCO2 < 1 Torr, pH 7.4, 36 degrees C) equilibrated at PO2 > 400 or approximately 150 Torr while chemosensory discharge was recorded extracellularly. ATP and adenosine 5'-[gamma-thio]triphosphate stimulated discharge with similar dose dependence, whereas adenosine had little effect. ATP infusion for > or = 2 min evoked an initial stimulation of discharge followed by a decline to baseline (desensitization). Desensitization did not affect the response to hypoxia (perfusate flow interruption) but inhibited the response to nicotine (4-nmol pulse). Therefore, 1) the carotid body has surface ATP receptors that may mediate the chemosensory response to nicotine but not to hypoxia and 2) nicotinic receptors are not required for carotid body O2 chemoreception. PMID:8366007

  5. Aortic Baroreceptors Display Higher Mechanosensitivity than Carotid Baroreceptors

    PubMed Central

    Lau, Eva On-Chai; Lo, Chun-Yin; Yao, Yifei; Mak, Arthur Fuk-Tat; Jiang, Liwen; Huang, Yu; Yao, Xiaoqiang

    2016-01-01

    Arterial baroreceptors are mechanical sensors that detect blood pressure changes. It has long been suggested that the two arterial baroreceptors, aortic and carotid baroreceptors, have different pressure sensitivities. However, there is no consensus as to which of the arterial baroreceptors are more sensitive to changes in blood pressure. In the present study, we employed independent methods to compare the pressure sensitivity of the two arterial baroreceptors. Firstly, pressure-activated action potential firing was measured by whole-cell current clamp with a high-speed pressure clamp system in primary cultured baroreceptor neurons. The results show that aortic depressor neurons possessed a higher percentage of mechano-sensitive neurons. Furthermore, aortic baroreceptor neurons show a lower pressure threshold than that of carotid baroreceptor neurons. Secondly, uniaxial stretching of baroreceptor neurons, that mimics the forces exerted on blood vessels, elicited a larger increase in intracellular Ca2+ rise in aortic baroreceptor neurons than in carotid baroreceptor neurons. Thirdly, the pressure-induced action potential firing in the aortic depressor nerve recorded in vivo was also higher. The present study therefore provides for a basic physiological understanding on the pressure sensitivity of the two baroreceptor neurons and suggests that aortic baroreceptors have a higher pressure sensitivity than carotid baroreceptors.

  6. Outcome After Surgical Treatment of Paraclinoid Carotid Aneurysms.

    PubMed

    Pasqualin, Alberto; Meneghelli, Pietro; Cozzi, Francesco; Chioffi, Franco

    2016-01-01

    Surgery on paraclinoid carotid aneurysms is technically demanding and entails considerable risks, especially to visual function. The aim of this study was to evaluate the clinical and visual outcome after surgery in 66 patients with paraclinoid carotid aneurysms (30 ruptured and 36 unruptured) treated between 1990 and 2014. Thirty-six aneurysms were of standard size, and 30 were large (16-20 mm) or giant (>20 mm); the Barami classification was used in every case. During surgery, multiple clips were needed in 25 % of patients with standard, and in 80 % of patients with large-giant aneurysms; temporary carotid occlusion was performed on 11 % of patients with standard and 63 % with large-giant aneurysms. Postoperatively, a cerebrospinal fluid fistula was repaired surgically in two patients. At the 3-month follow-up, the modified Rankin Score (mRS) was favorable (0-2) in 63 % of patients with ruptured and in 97 % with unruptured aneurysms; four patients presenting with large hematomas died. Postoperative visual impairment (worsening or newly developing deficit) was noted in 25 % of cases with standard and 14 % of cases with large-giant ruptured aneurysms, and, respectively, in 10 % with standard and 31 % with large-giant unruptured aneurysms. It has been concluded that surgery remains a reasonable choice in the management of patients with paraclinoid carotid aneurysms. PMID:27637626

  7. [Revascularization of the carotid and vertebral arteries in the elderly].

    PubMed

    Illuminati, G; Bezzi, M; D'Urso, A; Giacobbi, D; Ceccanei, G; Vietri, F

    2004-01-01

    From January 1994 to July 2004, 323 patients underwent 348 revascularization of carotid bifurcation for atherosclerotic stenoses. Eighty eight patients (group A) were 75 year-old or older, whereas 235 (group B) were younger than 75 years. Postoperative mortality/neurologic morbidity rate was 1% in group A, and 1.4% in group B. At 5 years, patency and freedom from symptoms/stroke were, respectively, 91% and 92% in group A, and 89% and 91% in group B. None of these differences was statistically significant. In the same time period, 26 internal carotid arteries were revascularized in 24 patients, 75 or more aged, for a symptomatic kinking. Postoperative mortality/morbidity rate was absent, whereas, at 5 years, patency and freedom from symptoms/stroke were, respectively, 88% and 92%. Twelve vertebral arteries were revascularized in 12 patients, 75 or more aged, for invalidating symptoms of vertebrobasilar insufficiency. Postoperative mortality/neurologic morbidity rate was absent. In one case postoperative recurrence of symptoms occurred, despite a patent revascularization. Patency and freedom from symptoms/stroke were 84% and 75%, at 5 years. Revascularization of carotid and vertebral arteries in the elderly can be accomplished with good results, superposable to those of standard revascularization of carotid bifurcation in a younger patients' population. PMID:15803810

  8. Design of the Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST)

    PubMed Central

    Sheffet, Alice J.; Roubin, Gary; Howard, George; Howard, Virginia; Moore, Wesley; Meschia, James F.; Hobson, Robert W.; Brott, Thomas G.

    2009-01-01

    Rationale Carotid endarterectomy (CEA) and medical therapy were shown superior to medical therapy alone for symptomatic (≥50%) and asymptomatic (≥60%) stenosis. Carotid angioplasty stenting (CAS) offers a less invasive alternative. Establishing safety, efficacy, and durability of CAS requires rigorous comparison with CEA in symptomatic and asymptomatic patients. Aims The objective is to compare the efficacy of CAS versus CEA in patients with symptomatic (≥50%) or asymptomatic (≥60%) extracranial carotid stenosis. Design The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST) is a prospective, randomized, parallel, two-arm, multi-center trial with blinded endpoint adjudication. Primary endpoints are analyzed using standard time-to-event statistical modeling with adjustment for major baseline covariates. Primary analysis is on an intent-to-treat basis. Study Outcomes The primary outcome is the occurrence of any stroke, myocardial infarction, or death during a 30-day peri-procedural period, and ipsilateral stroke during follow-up of up to four years. Secondary outcomes include restenosis and health-related quality of life. PMID:20088993

  9. Towards Precision Medicine: Advances in Computational Approaches for the Analysis of Human Variants

    PubMed Central

    Peterson, Thomas A; Doughty, Emily; Kann, Maricel G

    2013-01-01

    Variations and similarities in our individual genomes are part of our history, our heritage, and our identity. Some human genomic variants are associated with common traits such as hair and eye color, while others are associated with susceptibility to disease or response to drug treatment. Identifying the human variations producing clinically relevant phenotypic changes is critical for providing accurate and personalized diagnosis, prognosis, and treatment for diseases. Furthermore, a better understanding of the molecular underpinning of disease can lead to development of new drug targets for precision medicine. Several resources have been designed for collecting and storing human genomic variations in highly structured, easily accessible databases. Unfortunately, a vast amount of information about these genetic variants and their functional and phenotypic associations is currently buried in the literature, only accessible by manual curation or sophisticated text mining technology to extract the relevant information. In addition, the low cost of sequencing technologies coupled with increasing computational power has enabled the development of numerous computational methodologies to predict the pathogenicity of