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Sample records for carotid body type

  1. Measurements of intracellular Ca2+ in dissociated type I cells of the rabbit carotid body.

    PubMed Central

    Biscoe, T J; Duchen, M R; Eisner, D A; O'Neill, S C; Valdeolmillos, M

    1989-01-01

    1. The carotid body chemoreceptors are stimulated in situ by cyanide (CN-), which mimics the effect of hypoxia. We have shown that CN- increases a calcium-dependent potassium conductance (gK(Ca)) in single type I cells dissociated from the carotid body of the rabbit. We have now used the Ca2(+)-sensitive fluorophore, Fura-2, to measure intracellular Ca2+ directly in single type I cells. 2. CN- reversibly increased [Ca2+]i from approximately 90 nM to a mean of approximately 200 nM. Some of this Ca2+ originated from an intracellular store, which was depleted by exposure to Ca2(+)-free solutions. Prolonged application of CN- caused a sustained increase in [Ca2+]i, suggesting that CN- impairs the removal or sequestration of Ca2+. 3. pHi measured with the dye BCECF (2,7-bis(2-carboxyethyl)-5(and-6)-carboxyfluorescein) did not change consistently in response to CN-, although pHi changed predictably in response to both ammonium chloride and to acidification of the superfusate with CO2. 4. Potassium-induced depolarization (35 mM-K+) caused a large, cadmium-sensitive rise in [Ca2+]i. The K(+)-induced Ca2+ load was used to study the regulation of [Ca2+]i. 5. The clearance of a Ca2+ load was slowed either by removal of [Na+]o or by application of CN-. This shows that both a Na+-Ca2+ exchange and an energy-dependent process or processes contribute to the regulation of [Ca2+]i. 6. Carbachol (CCh, 10-100 microM), which also hyperpolarizes type I cells, caused a small transient rise in [Ca2+]i, indicating release from an exhaustible intracellular pool. The response to CN- was unaffected by prior or continued exposure to CCh, suggesting that the two stimuli operate by distinct mechanisms. 7. The increased gK(Ca) seen in type I cells in response to CN- thus reflects a change in cellular Ca2+ homeostasis. The rise in [Ca2+]i presumably underlies the documented increase in transmitter release from the carotid body in response to CN-. If chemotransduction is a consequence of the

  2. CaV3.2 T-type Ca²⁺ channels in H₂S-mediated hypoxic response of the carotid body.

    PubMed

    Makarenko, Vladislav V; Peng, Ying-Jie; Yuan, Guoxiang; Fox, Aaron P; Kumar, Ganesh K; Nanduri, Jayasri; Prabhakar, Nanduri R

    2015-01-15

    Arterial blood O2 levels are detected by specialized sensory organs called carotid bodies. Voltage-gated Ca(2+) channels (VGCCs) are important for carotid body O2 sensing. Given that T-type VGCCs contribute to nociceptive sensation, we hypothesized that they participate in carotid body O2 sensing. The rat carotid body expresses high levels of mRNA encoding the α1H-subunit, and α1H protein is localized to glomus cells, the primary O2-sensing cells in the chemoreceptor tissue, suggesting that CaV3.2 is the major T-type VGCC isoform expressed in the carotid body. Mibefradil and TTA-A2, selective blockers of the T-type VGCC, markedly attenuated elevation of hypoxia-evoked intracellular Ca(2+) concentration, secretion of catecholamines from glomus cells, and sensory excitation of the rat carotid body. Similar results were obtained in the carotid body and glomus cells from CaV3.2 knockout (Cacna1h(-/-)) mice. Since cystathionine-γ-lyase (CSE)-derived H2S is a critical mediator of the carotid body response to hypoxia, the role of T-type VGCCs in H2S-mediated O2 sensing was examined. Like hypoxia, NaHS, a H2S donor, increased intracellular Ca(2+) concentration and augmented carotid body sensory nerve activity in wild-type mice, and these effects were markedly attenuated in Cacna1h(-/-) mice. In wild-type mice, TTA-A2 markedly attenuated glomus cell and carotid body sensory nerve responses to hypoxia, and these effects were absent in CSE knockout mice. These results demonstrate that CaV3.2 T-type VGCCs contribute to the H2S-mediated carotid body response to hypoxia. PMID:25377087

  3. Effects of hypercapnia on membrane potential and intracellular calcium in rat carotid body type I cells.

    PubMed Central

    Buckler, K J; Vaughan-Jones, R D

    1994-01-01

    1. An acid-induced rise in the intracellular calcium concentration ([Ca2+]i) of type I cells is thought to play a vital role in pH/PCO2 chemoreception by the carotid body. In this present study we have investigated the cause of this rise in [Ca2+]i in enzymatically isolated, neonatal rat type I cells. 2. The rise in [Ca2+]i induced by a hypercapnic acidosis was inhibited in Ca(2+)-free media, and by 2 mM Ni2+. Acidosis also increased Mn2+ permeability. The rise in [Ca2+]i is dependent, therefore, upon a Ca2+ influx from the external medium. 3. The acid-induced rise in [Ca2+]i was attenuated by both nicardipine and methoxyverapamil (D600), suggesting a role for L-type Ca2+ channels. 4. Acidosis depolarized type I cells and often (approximately 50% of cells) induced action potentials. These effects coincided with a rise in [Ca2+]i. When membrane depolarization was prevented by a voltage clamp, acidosis failed to evoke a rise in [Ca2+]i. The acid-induced rise in [Ca2+]i is a consequence, therefore, of membrane depolarization. 5. Acidosis decreased the resting membrane conductance of type I cells. The reversal potential of the acid-sensitive current was about -75 mV. 6. A depolarization (30 mM [K+]o)-induced rise in [Ca2+]i was blocked by either the removal of extracellular Ca2+ or the presence of 2 mM Ni2+, and was also substantially inhibited by nicardipine. Under voltage-clamp conditions, [Ca2+]i displayed a bell-shaped dependence on membrane potential. Depolarization raises [Ca2+]i, therefore, through voltage-operated Ca2+ channels. 7. Caffeine (10 mM) induced only a small rise in [Ca2+]i (< 10% of that induced by 30 mM extracellular K+). Ca(2+)-induced Ca2+ release is unlikely, therefore, to contribute greatly to the rise in [Ca2+]i induced by depolarization. 8. Although the replacement of extracellular Na+ with N-methyl-D-glucamine (NMG), but not Li+, inhibited the acid-induced rise in [Ca2+]i, this was due to membrane hyperpolarization and not to the inhibition

  4. Effects of mitochondrial uncouplers on intracellular calcium, pH and membrane potential in rat carotid body type I cells

    PubMed Central

    Buckler, K J; Vaughan-Jones, R D

    1998-01-01

    Mitochondrial uncouplers are potent stimulants of the carotid body. We have therefore investigated their effects upon isolated type I cells. Both 2,4-dinitrophenol (DNP) and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) caused an increase in [Ca2+]i which was largely inhibited by removal of extracellular Ca2+ or Na+, or by the addition of 2 mm Ni2+. Methoxyverapamil (D600) also partially inhibited the [Ca2+]i response. In perforated-patch recordings, the rise in [Ca2+]i coincided with membrane depolarization and was greatly reduced by voltage clamping the cell to −70 mV. Uncouplers also inhibited a background K+ current and induced a small inward current. Uncouplers reduced pHi by 0.1 unit. Alkaline media diminished this acidification but had no effect on the [Ca2+]i response. FCCP and DNP also depolarized type I cell mitochondria. The onset of mitochondrial depolarization preceded changes in cell membrane conductance by 3–4 s. We conclude that uncouplers excite the carotid body by inhibiting a background K+ conductance and inducing a small inward current, both of which lead to membrane depolarization and voltage-gated Ca2+ entry. These effects are unlikely to be caused by cell acidification. The inhibition of background K+ current may be related to the uncoupling of oxidative phosphorylation. PMID:9824720

  5. Effects of mitochondrial uncouplers on intracellular calcium, pH and membrane potential in rat carotid body type I cells.

    PubMed

    Buckler, K J; Vaughan-Jones, R D

    1998-12-15

    1. Mitochondrial uncouplers are potent stimulants of the carotid body. We have therefore investigated their effects upon isolated type I cells. Both 2,4-dinitrophenol (DNP) and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) caused an increase in [Ca2+]i which was largely inhibited by removal of extracellular Ca2+ or Na+, or by the addition of 2 mM Ni2+. Methoxyverapamil (D600) also partially inhibited the [Ca2+]i response. 2. In perforated-patch recordings, the rise in [Ca2+]i coincided with membrane depolarization and was greatly reduced by voltage clamping the cell to -70 mV. Uncouplers also inhibited a background K+ current and induced a small inward current. 3. Uncouplers reduced pHi by 0.1 unit. Alkaline media diminished this acidification but had no effect on the [Ca2+]i response. 4. FCCP and DNP also depolarized type I cell mitochondria. The onset of mitochondrial depolarization preceded changes in cell membrane conductance by 3-4 s. 5. We conclude that uncouplers excite the carotid body by inhibiting a background K+ conductance and inducing a small inward current, both of which lead to membrane depolarization and voltage-gated Ca2+ entry. These effects are unlikely to be caused by cell acidification. The inhibition of background K+ current may be related to the uncoupling of oxidative phosphorylation. PMID:9824720

  6. 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

  7. Hyperbaric Oxygen Therapy Improves Glucose Homeostasis in Type 2 Diabetes Patients: A Likely Involvement of the Carotid Bodies.

    PubMed

    Vera-Cruz, P; Guerreiro, F; Ribeiro, M J; Guarino, M P; Conde, S V

    2015-01-01

    The carotid bodies (CBs) are peripheral chemoreceptors that respond to hypoxia increasing minute ventilation and activating the sympathetic nervous system. Besides its role in ventilation we recently described that CB regulate peripheral insulin sensitivity. Knowing that the CB is functionally blocked by hyperoxia and that hyperbaric oxygen therapy (HBOT) improves fasting blood glucose in diabetes patients, we have investigated the effect of HBOT on glucose tolerance in type 2 diabetes patients. Volunteers with indication for HBOT were recruited at the Subaquatic and Hyperbaric Medicine Center of Portuguese Navy and divided into two groups: type 2 diabetes patients and controls. Groups were submitted to 20 sessions of HBOT. OGTT were done before the first and after the last HBOT session. Sixteen diabetic patients and 16 control individual were included. Fasting glycemia was143.5 ± 12.62 mg/dl in diabetic patients and 92.06 ± 2.99 mg/dl in controls. In diabetic patients glycemia post-OGTT was 280.25 ± 22.29 mg/dl before the first HBOT session. After 20 sessions, fasting and 2 h post-OGTT glycemia decreased significantly. In control group HBOT did not modify fasting glycemia and post-OGTT glycemia. Our results showed that HBOT ameliorates glucose tolerance in diabetic patients and suggest that HBOT could be used as a therapeutic intervention for type 2 diabetes. PMID:26303484

  8. Type I cell ROS kinetics under hypoxia in the intact mouse carotid body ex vivo: a FRET-based study.

    PubMed

    Bernardini, A; Brockmeier, U; Metzen, E; Berchner-Pfannschmidt, U; Harde, E; Acker-Palmer, A; Papkovsky, D; Acker, H; Fandrey, J

    2015-01-01

    Reactive oxygen species (ROS) mainly originating from NADPH oxidases have been shown to be involved in the carotid body (CB) oxygen-sensing cascade. For measuring ROS kinetics, type I cells of the mouse CB in an ex vivo preparation were transfected with the ROS sensor construct FRET-HSP33. After 2 days of tissue culture, type I cells expressed FRET-HSP33 as shown by immunohistochemistry. In one population of CBs, 5 min of hypoxia induced a significant and reversible decrease of type I cell ROS levels (n = 9 CBs; P < 0.015), which could be inhibited by 4-(2-aminoethyl)benzensulfonylfluorid (AEBSF), a highly specific inhibitor of the NADPH oxidase subunits p47(phox) and p67(phox). In another population of CBs, however, 5 min of hypoxia induced a significant and reversible increase of ROS levels in type I cells (n = 8 CBs; P < 0.05), which was slightly enhanced by administration of 3 mM AEBSF. These different ROS kinetics seemed to coincide with different mice breeding conditions. Type I cells of both populations showed a typical hypoxia-induced membrane potential (MP) depolarization, which could be inhibited by 3 mM AEBSF. ROS and MP closely followed the hypoxic decrease in CB tissue oxygen as measured with an O2-sensitive dye. We conclude that attenuated p47(phox) subunit activity of the NADPH oxidase under hypoxia is the physiological trigger for type I cell MP depolarization probably due to ROS decrease, whereas the observed ROS increase has no influence on type I cell MP kinetics under hypoxia. PMID:25318107

  9. Carotid body tumor: a 25-year experience.

    PubMed

    Metheetrairut, Choakchai; Chotikavanich, Chanticha; Keskool, Phawin; Suphaphongs, Nit

    2016-08-01

    Carotid body tumor is an uncommon hypervascular benign tumor in the head and neck region. It usually presents as a slow growing mass at the carotid bifurcation. Because of the high rate of neurovascular complications, resection of this tumor is considered challenging for otolaryngologists. Between 1988 and 2013, 40 carotid body tumors from 38 patients were diagnosed and underwent resection at Siriraj Hospital (25 female and 13 male patients). Their age ranged from 15 to 59 years. Seven patients had bilateral tumors simultaneously whereas six cases had familial history of carotid body tumor. Carotid angiography was performed in 29 cases; other additional diagnostic studies included CT scan, MRI, and MRA to detect the widening of carotid bifurcation, its extension, and multifocal tumors. All diagnosed tumors were successfully removed. However, internal carotid artery and carotid bifurcation were injured in 11 cases (27.5 %). Shamblin class III and previous biopsy history were considered risk factors for vascular injury. Postoperative cranial nerves deficit was found in 20 % of the cases and CNS complication occurred in two patients (5 %). There was no surgical mortality. Additionally, upon the mean follow-up period of 36 months, no recurrence or malignant transformation was detected in this study. Multidisciplinary approach, early tumor detection, meticulous preoperative evaluation, and modern vascular surgical technique are the key success factors for tumor removal. PMID:26233244

  10. Symptomatic carotid stenosis in the setting of bilateral disease and coexisting carotid body tumor: management with a carotid stent and staged excision.

    PubMed

    Smeds, Matthew; Jacobs, Donald

    2013-12-01

    The aim of the paper is to describe the management of a patient with bilateral carotid artery stenosis, symptomatic on the left, with coexisting left carotid body tumor with left carotid stenting followed by right carotid endarterectomy and excision of carotid body tumor. A 60-year-old man with significant bilateral carotid stenosis was referred to us with symptomatic left carotid disease and concomitant left carotid body tumor. A Precise nitinol carotid stent (Cordis Endovascular, Miami Lakes, FL, USA) was placed in his left carotid artery followed by interval carotid endarterectomy on the right. Excision of the carotid body tumor was then performed. Carotid stenting is a treatment option in patients with carotid stenosis and coexisting carotid body tumor. To our knowledge, this is the first reported carotid stent for symptomatic carotid stenosis in a patient with a concomitant carotid body tumor. PMID:23493283

  11. CaV3.2 T-type Ca2+ channels mediate the augmented calcium influx in carotid body glomus cells by chronic intermittent hypoxia.

    PubMed

    Makarenko, Vladislav V; Ahmmed, Gias U; Peng, Ying-Jie; Khan, Shakil A; Nanduri, Jayasri; Kumar, Ganesh K; Fox, Aaron P; Prabhakar, Nanduri R

    2016-01-01

    Chronic intermittent hypoxia (CIH) is a hallmark manifestation of sleep apnea. A heightened carotid body activity and the resulting chemosensory reflex mediate increased sympathetic nerve activity by CIH. However, the mechanisms underlying heightened carotid body activity by CIH are not known. An elevation of intracellular calcium ion concentration ([Ca(2+)]i) in glomus cells, the primary oxygen-sensing cells, is an essential step for carotid body activation by hypoxia. In the present study, we examined the effects of CIH on the glomus cell [Ca(2+)]i response to hypoxia and assessed the underlying mechanisms. Glomus cells were harvested from adult rats or wild-type mice treated with 10 days of either room air (control) or CIH (alternating cycles of 15 s of hypoxia and 5 min of room air; 9 episodes/h; 8 h/day). CIH-treated glomus cells exhibited an enhanced [Ca(2+)]i response to hypoxia, and this effect was absent in the presence of 2-(4-cyclopropylphenyl)-N-((1R)-1-[5-[(2,2,2-trifluoroethyl)oxo]-pyridin-2-yl]ethyl)acetamide (TTA-A2), a specific inhibitor of T-type Ca(2+) channels, and in voltage-gated calcium channel, type 3.2 (CaV3.2), null glomus cells. CaV3.2 knockout mice exhibited an absence of CIH-induced hypersensitivity of the carotid body. CIH increased reactive oxygen species (ROS) levels in glomus cells. A ROS scavenger prevented the exaggerated TTA-A2-sensitive [Ca(2+)]i response to hypoxia. CIH had no effect on CaV3.2 mRNA levels. CIH augmented Ca(2+) currents and increased CaV3.2 protein in plasma membrane fractions of human embryonic kidney-293 cells stably expressing CaV3.2, and either a ROS scavenger or brefeldin-A, an inhibitor of protein trafficking, prevented these effects. These findings suggest that CIH leads to an augmented Ca(2+) influx via ROS-dependent facilitation of CaV3.2 protein trafficking to the plasma membrane. PMID:26561606

  12. Association between adjunctive metformin therapy in young type 1 diabetes patients with excess body fat and reduction of carotid intima-media thickness.

    PubMed

    Burchardt, Paweł; Zawada, Agnieszka; Kaczmarek, Jolanta; Marcinkaniec, Justyna; Wysocki, Henryk; Wierusz-Wysocka, Bogna; Grzymisławski, Marian; Rzeźniczak, Janusz; Zozulińska-Ziółkiewicz, Dorota; Naskręt, Dariusz

    2016-08-25

    INTRODUCTION    Lipoprotein-associated phospholipase A2 (Lp-PLA2) and cholesteryl ester lipase (CEL) may oxidize low-density lipoproteins (oxLDL). OBJECTIVES    The aim of the study was to determine the influence of metformin on the metabolism of atherogenic lipid fractions in relation to Lp-PLA2 and CEL levels, as well as assess consequent improvement in the intima-media thickness (IMT) of the common carotid artery in young type 1 diabetes patients with excess body fat. PATIENTS AND METHODS    It was an open-label randomized clinical trial that lasted 6 months. It included a total of 84 people with metabolic decompensation (glycated hemoglobin >7.5%, >58.5 mmol/mol) of diabetes. Adjunctive metformin therapy (in addition to insulin) was administered in 42 patients, and the remaining 42 patients received insulin alone. Glycated low-density lipoproteins (LDLs), oxLDL, Lp-PLA2, and CEL were assessed by commercially available enzyme-linked immunosorbent assay kits. Cartoid IMT was measured using the Carotid Analyser for Research tool. Biochemical analyses were performed using routine laboratory techniques. RESULTS    The reduction of mean carotid IMT was observed in young type 1 diabetic adults treated additionally with metformin (0.6 ±0.1 cm vs 0.53 ±0.1 cm; P = 0.002). This effect was probably due to weight reduction (90 ±16 kg vs 87 ±15 kg, P = 0.054) and the decrease in atherogenic glycated LDL levels (1.5 ±0.5 mg/dl vs 1.6 ±1.046 mg/dl, P = 0.006). No such correlations were observed in patients treated with insulin alone. Additionally, in patients receiving metformin, glycated LDL levels were inversely correlated with Lp-PLA2 levels (r = -0.31, P <0.05). CONCLUSIONS    Additional use of metformin in young type 1 diabetic patients with excess body fat leads to a significant reduction of mean IMT in the common carotid artery. Concentrations of CEL and Lp-PLA2 were significantly increased in both study arms despite improved glucose metabolism

  13. Regulation of tyrosine hydroxylase gene expression in the rat carotid body by hypoxia.

    PubMed

    Czyzyk-Krzeska, M F; Bayliss, D A; Lawson, E E; Millhorn, D E

    1992-04-01

    The activity (Vmax) of tyrosine hydroxylase (TH; EC 1.14.16.2), the rate limiting enzyme in the synthesis of catecholamines, is increased in carotid body, superior cervical ganglion, and the adrenal medulla during hypoxia (i.e., reduced PaO2). The present study was undertaken to determine if the increase in TH activity in these tissues during hypoxia is regulated at the level of TH mRNA. Adult rats were exposed to hypoxia (10% O2) or room air for periods lasting from 1 to 48 h. The carotid bodies, superior cervical ganglia, and adrenals were removed and processed for in situ hybridization using 35S-labeled oligonucleotide probes. The concentration of TH mRNA was increased by hypoxia at all time points in carotid body type I cells, but not in cells of either superior cervical ganglion or adrenal medulla. The increase in TH mRNA in carotid body during hypoxia did not require innervation of the carotid body or intact adrenal glands. In addition, hypercapnia, another physiological stimulus of carotid body activity, failed to induce an increase in TH mRNA in type I cells. Our findings suggest that hypoxia stimulates TH gene expression in the carotid body by a mechanism that is intrinsic to type I cells. PMID:1347783

  14. A preliminary anatomical study on carotid body of Makouei sheep

    PubMed Central

    Najafi, Gholamreza; Soltanalinejad, Farhad; Hasanzadeh, Hamed

    2013-01-01

    The carotid is a small mass of chemoreceptor's and sustentacular cells that detects changes in the composition of the arterial blood. The aim of the present study was to identify the size, color, location, blood and nerve supply of the carotid body in Makouei sheep. Fourteen heads of sheep from both sexes were collected from Urmia public slaughter-house. The exact situation and nerve supply of the carotid body was determined. Before dissection, blue latex was injected into right and left common carotid arteries. All the branches of the common carotid artery and the branch supplying carotid body were investigated. This study showed that, carotid body in sheep has been situated around the muscular branch of the occipital artery. The mean weight, width and length, thickness of carotid body were 0.01 g, 0.83 mm, 1.07 mm, and 1.06 mm respectively. Blood to the carotid body was supplied by glomic artery which was a branch of occipital artery. It was innervated by herring nerve which was a branch of glossopharyngeal nerve. PMID:25653785

  15. A preliminary anatomical study on carotid body of Makouei sheep.

    PubMed

    Najafi, Gholamreza; Soltanalinejad, Farhad; Hasanzadeh, Hamed

    2013-01-01

    The carotid is a small mass of chemoreceptor's and sustentacular cells that detects changes in the composition of the arterial blood. The aim of the present study was to identify the size, color, location, blood and nerve supply of the carotid body in Makouei sheep. Fourteen heads of sheep from both sexes were collected from Urmia public slaughter-house. The exact situation and nerve supply of the carotid body was determined. Before dissection, blue latex was injected into right and left common carotid arteries. All the branches of the common carotid artery and the branch supplying carotid body were investigated. This study showed that, carotid body in sheep has been situated around the muscular branch of the occipital artery. The mean weight, width and length, thickness of carotid body were 0.01 g, 0.83 mm, 1.07 mm, and 1.06 mm respectively. Blood to the carotid body was supplied by glomic artery which was a branch of occipital artery. It was innervated by herring nerve which was a branch of glossopharyngeal nerve. PMID:25653785

  16. 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.

  17. Autoradiographic localization of alpha-bungarotoxin-binding sites in the carotid body of the rat.

    PubMed

    Chen, I; Mascorro, J A; Yates, R D

    1981-01-01

    Radioiodinated alpha-bungarotoxin (alpha-Bgt) was used to localize alpha-Bgt-acetylcholine receptors in the carotid body of the rat. The gamma spectrometer analyses indicated a high uptake of [125I] alpha-Bgt in carotid bodies incubated in vitro (1.51 fmole per organ). Incorporation of the isotope was effectively blocked by pretreatment of carotid bodies with d-tubocurarine and unlabeled alpha-Bgt, but not by atropine. Light microscopic autoradiography showed a heavy labeling of some parenchymal cells. Electron-microscopic autoradiography revealed that labeling was localized along the interface between parenchymal cells, especially where their cytoplasmic processes engage in complex interdigitations. The silver grain counts on electron-microscopic autoradiographs suggest that labelings are preferentially associated with the plasma membrane of certain Type I cells. It is suggested that these Type I cells in the rat's carotid body probably are provided with nicotinic acetylcholine receptors on their plasma membranes. PMID:7273116

  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. Reflex carotid body chemoreceptor control of phrenic sympathetic neurons.

    PubMed

    Bałkowiec, A; Revenko, S; Szulczyk, P

    1993-04-01

    The reflex reaction of phrenic sympathetic neurons to stimulation of carotid body chemoreceptors was tested in chloralose-anesthetized and paralyzed cats with both vago-aortic nerves cut. During systemic hypoxia (animals ventilated with 10% O2 in N2) the sympathetic phrenic nerve activity increased from 100% in the control to 269%. This increase was markedly attenuated after cutting both sinus nerves. Reflex excitatory response in phrenic sympathetic neurons with the latency of 150 msec was evoked by electrical stimulation of the right carotid sinus nerve (3 pulses of 0.2 msec, 333 Hz). The central transmission time of the reflex was about 90 msec. Injecting 0.1 ml of 1 M NaHCO3 saturated with CO2 (in order to activate carotid body chemoreceptors) into the right or left carotid sinus, evoked excitatory responses in sympathetic neurons regardless of the side. The stimulation of carotid body chemoreceptors also increased somatic phrenic nerve activity. The three methods applied to the stimulation of carotid body chemoreceptors produced increase of phrenic nerve sympathetic activity. PMID:8390088

  20. Spexin is expressed in the carotid body and is upregulated by postnatal hyperoxia exposure.

    PubMed

    Porzionato, Andrea; Rucinski, Marcin; Macchi, Veronica; Stecco, Carla; Sarasin, Gloria; Sfriso, Maria M; Di Giulio, Camillo; Malendowicz, Ludwik K; De Caro, Raffaele

    2012-01-01

    Spexin is a recently identified peptide which is expressed in many different endocrine and nervous tissues. Due to the absence of data regarding spexin expression in the carotid body, the first aim of the present study was to investigate, through immunohistochemistry and Real-Time PCR, the expression and distribution of spexin in the rat and human carotid body. Moreover, the carotid body is known to undergo various structural and functional modifications in response to hyperoxic stimuli during the first postnatal period. Thus, we also evaluated if hyperoxia during the first postnatal weeks may produce changes in the spexin expression. Materials consisted of carotid bodies obtained at autopsy from five human adult subjects and sampled from 10 six-weeks old Sprague-Dawley rats. Five rats were maintained in normoxia for the first six postnatal weeks; five rats were exposed to 60% hyperoxia for 2 weeks and then maintained in normoxia for other 4 weeks. Diffuse anti-spexin immunoreactivity was found in type I cells of both humans and rats. No spexin immunoreactivity was visible in the type II cells. Hyperoxia exposure during the first 2 weeks of postnatal life caused a reduction of volume in the carotid body still apparent after 4 weeks of normoxia. Using real-time PCR, spexin expression was 6-7 times higher in hyperoxia-exposed rats than in normoxia-exposed ones. The expression of spexin in type I cells suggests a possible modulator role in peripheral chemoreception. Moreover, the ascertained role of spexin in the regulation of cell proliferation in other tissues (e.g., adrenal gland cortex) suggests a possible role of spexin also in the hyperoxia-induced plasticity of the carotid body. PMID:23080164

  1. Carotid body, insulin, and metabolic diseases: unraveling the links.

    PubMed

    Conde, Sílvia V; Sacramento, Joana F; Guarino, Maria P; Gonzalez, Constancio; Obeso, Ana; Diogo, Lucilia N; Monteiro, Emilia C; Ribeiro, Maria J

    2014-01-01

    The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future. PMID:25400585

  2. Carotid body, insulin, and metabolic diseases: unraveling the links

    PubMed Central

    Conde, Sílvia V.; Sacramento, Joana F.; Guarino, Maria P.; Gonzalez, Constancio; Obeso, Ana; Diogo, Lucilia N.; Monteiro, Emilia C.; Ribeiro, Maria J.

    2014-01-01

    The carotid bodies (CB) are peripheral chemoreceptors that sense changes in arterial blood O2, CO2, and pH levels. Hypoxia, hypercapnia, and acidosis activate the CB, which respond by increasing the action potential frequency in their sensory nerve, the carotid sinus nerve (CSN). CSN activity is integrated in the brain stem to induce a panoply of cardiorespiratory reflexes aimed, primarily, to normalize the altered blood gases, via hyperventilation, and to regulate blood pressure and cardiac performance, via sympathetic nervous system (SNS) activation. Besides its role in the cardiorespiratory control the CB has been proposed as a metabolic sensor implicated in the control of energy homeostasis and, more recently, in the regulation of whole body insulin sensitivity. Hypercaloric diets cause CB overactivation in rats, which seems to be at the origin of the development of insulin resistance and hypertension, core features of metabolic syndrome and type 2 diabetes. Consistent with this notion, CB sensory denervation prevents metabolic and hemodynamic alterations in hypercaloric feed animal. Obstructive sleep apnea (OSA) is another chronic disorder characterized by increased CB activity and intimately related with several metabolic and cardiovascular abnormalities. In this manuscript we review in a concise manner the putative pathways linking CB chemoreceptors deregulation with the pathogenesis of insulin resistance and arterial hypertension. Also, the link between chronic intermittent hypoxia (CIH) and insulin resistance is discussed. Then, a final section is devoted to debate strategies to reduce CB activity and its use for prevention and therapeutics of metabolic diseases with an emphasis on new exciting research in the modulation of bioelectronic signals, likely to be central in the future. PMID:25400585

  3. Surgical Excision of Carotid Body Tumor Through Modified Approach-A Case Report.

    PubMed

    Prabakaran, Sureshkannan; Subburayulu, Anand Shankar; Ravikumar, P T

    2016-06-01

    Paragangliomas arising from the carotid body in the carotid bifurcation are termed as carotid body tumors. They are usually slow growing and asymptomatic. Considering the anatomical location, invasion or pressure on the adjacent vascular and neural tissues, the importance of early diagnosis and management is critical. In this article a case of carotid body tumor excised through transverse neck skin crease incision is presented along with literature review on the diagnosis, grading and different surgical approaches. PMID:27298550

  4. Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia

    PubMed Central

    Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C.; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J.; Schwartz, Alan R.; Shirahata, Machiko

    2014-01-01

    Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.–9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. PMID:25103977

  5. Carotid body denervation prevents fasting hyperglycemia during chronic intermittent hypoxia.

    PubMed

    Shin, Mi-Kyung; Yao, Qiaoling; Jun, Jonathan C; Bevans-Fonti, Shannon; Yoo, Doo-Young; Han, Woobum; Mesarwi, Omar; Richardson, Ria; Fu, Ya-Yuan; Pasricha, Pankaj J; Schwartz, Alan R; Shirahata, Machiko; Polotsky, Vsevolod Y

    2014-10-01

    Obstructive sleep apnea causes chronic intermittent hypoxia (IH) and is associated with impaired glucose metabolism, but mechanisms are unknown. Carotid bodies orchestrate physiological responses to hypoxemia by activating the sympathetic nervous system. Therefore, we hypothesized that carotid body denervation would abolish glucose intolerance and insulin resistance induced by chronic IH. Male C57BL/6J mice underwent carotid sinus nerve dissection (CSND) or sham surgery and then were exposed to IH or intermittent air (IA) for 4 or 6 wk. Hypoxia was administered by decreasing a fraction of inspired oxygen from 20.9% to 6.5% once per minute, during the 12-h light phase (9 a.m.-9 p.m.). As expected, denervated mice exhibited blunted hypoxic ventilatory responses. In sham-operated mice, IH increased fasting blood glucose, baseline hepatic glucose output (HGO), and expression of a rate-liming hepatic enzyme of gluconeogenesis phosphoenolpyruvate carboxykinase (PEPCK), whereas the whole body glucose flux during hyperinsulinemic euglycemic clamp was not changed. IH did not affect glucose tolerance after adjustment for fasting hyperglycemia in the intraperitoneal glucose tolerance test. CSND prevented IH-induced fasting hyperglycemia and increases in baseline HGO and liver PEPCK expression. CSND trended to augment the insulin-stimulated glucose flux and enhanced liver Akt phosphorylation at both hypoxic and normoxic conditions. IH increased serum epinephrine levels and liver sympathetic innervation, and both increases were abolished by CSND. We conclude that chronic IH induces fasting hyperglycemia increasing baseline HGO via the CSN sympathetic output from carotid body chemoreceptors, but does not significantly impair whole body insulin sensitivity. PMID:25103977

  6. Expression of leptin and leptin receptor isoforms in the rat and human carotid body.

    PubMed

    Porzionato, Andrea; Rucinski, Marcin; Macchi, Veronica; Stecco, Carla; Castagliuolo, Ignazio; Malendowicz, Ludwik K; De Caro, Raffaele

    2011-04-18

    Leptin is known to play a role in the modulation of metabolism and control of breathing acting mainly on central nervous structures, although additional actions on peripheral arterial chemoreceptors have also been suggested in the literature. We therefore examined by means of immunohistochemistry the expression of leptin and leptin receptors in the carotid bodies of rats and humans. Leptin expression and relative expression of leptin receptor isoforms were also studied in rats by real-time PCR. No leptin or leptin receptor immunoreactivities were visible in the type II cells of either series. In rat carotid bodies, diffuse positive stainings for leptin and leptin receptors (both with antibody recognizing all receptor isoforms and antibody specific for Ob-Rb) were observed in type I cells. In human carotid bodies, the mean percentage (±standard error) of leptin immunoreactive type I cells was 39.4%±5.1% and the percentages of leptin receptor immunoreactive type I cells were 57.3%±3.9% with antibody recognizing all receptor isoforms and 33.3%±4.2% with antibody specific for isoform Ob-Rb. Double immunofluorescences with anti-tyrosine hydroxylase (type I cell marker) and anti-glial fibrillary acidic protein (type II cell markers) confirmed the selective location of leptin and Ob-Rb in type I cells. Real-time PCR showed the expression of leptin and Ob-Ra, Ob-Rb, Ob-Rc and Ob-Rf isoform mRNA in the rat carotid body, levels of expression being Ob-Rf>Ob-Rc>Ob-Ra>Ob-Rb. Ob-Re mRNA was not detected. The above findings suggest a role of circulating or locally produced leptin in the regulation of chemoreceptor discharge and/or metabolic sensing function, by means of direct action on type I cells. PMID:21334312

  7. Surgical complications of carotid body tumors surgery: a review.

    PubMed

    Amato, B; Serra, R; Fappiano, F; Rossi, R; Danzi, M; Milone, M; Quarto, G; Benassai, G; Bianco, T; Amato, M; Furino, E; Compagna, R

    2015-12-01

    Carotid body tumor (CBT) is a rare neoplasm, although it represents about 65% of head and neck paragangliomas. Surgical excision is considered the appropriate therapy for CBTs. The aim of this study was to evaluate surgical outcomes on a large scale. We reviewed 19 studies between 2004 to 2014 with a total of 625 procedures. We observed a higher number of cases in women (62%). Only 3 (0,48%) deaths were reported as surgical complication. Total cranial nerve injuries were 302 (48,32%) of which 194 (31,04%) were transient and 108 (17,28%) were permanent. We found a total of 174 (27,84%) arterial injuries, most of which are external carotid artery (ECA) injuries. Cerebrovascular accident due to surgery were 15 (2,4%). We concluded that surgical resection remains the treatment of choice for these disease despite the related morbidity. PMID:26498887

  8. Gene expression and function of adenosine A(2A) receptor in the rat carotid body.

    PubMed

    Kobayashi, S; Conforti, L; Millhorn, D E

    2000-08-01

    The present study was undertaken to determine whether rat carotid bodies express adenosine (Ado) A(2A) receptors and whether this receptor is involved in the cellular response to hypoxia. Our results demonstrate that rat carotid bodies express the A(2A) and A(2B) Ado receptor mRNAs but not the A(1) or A(3) receptor mRNAs as determined by reverse transcriptase-polymerase chain reaction. In situ hybridization confirmed the expression of the A(2A) receptor mRNA. Immunohistochemical studies further showed that the A(2A) receptor is expressed in the carotid body and that it is colocalized with tyrosine hydroxylase in type I cells. Whole cell voltage-clamp studies using isolated type I cells showed that Ado inhibited the voltage-dependent Ca(2+) currents and that this inhibition was abolished by the selective A(2A) receptor antagonist ZM-241385. Ca(2+) imaging studies using fura 2 revealed that exposure to severe hypoxia induced elevation of intracellular Ca(2+) concentration ([Ca(2+)](i)) in type I cells and that extracellularly applied Ado significantly attenuated the hypoxia-induced elevation of [Ca(2+)](i). Taken together, our findings indicate that A(2A) receptors are present in type I cells and that activation of A(2A) receptors modulates Ca(2+) accumulation during hypoxia. This mechanism may play a role in regulating intracellular Ca(2+) homeostasis and cellular excitability during hypoxia. PMID:10926550

  9. Carotid body remodelling in l-NAME-induced hypertension in the rat.

    PubMed

    Felix, A S; Rocha, V N; Nascimento, A L R; de Carvalho, J J

    2012-05-01

    The carotid body (CB) is a chemoreceptor organ located at the bifurcation of the common carotid artery. It is made up of the carotid glomus, a structure containing type 1 cells surrounded by type 2 cells. The aim of this study was to evaluate the morphological changes of the CB and carotid glomus in the rat model of l-NAME-induced hypertension. Male Wistar rats were divided in two groups: control untreated rats (C) and rats receiving l-NAME 40 mg/kg/day (LN) for 6 weeks. At the end of the experiment, the systolic blood pressure was 63% higher in the LN group compared with the C group. Morphometric analysis showed that the area of the CB was 29% greater in the LN group compared with the C group. The density of nuclei in the CB was similar between groups, but it was 31% less in the carotid glomus of the LN group. Cells in the CB of the LN group displayed cytoplasmic vacuolation and expressed several biogenic amines. There were more elastic fibres, proteoglycans and collagen fibres in the LN group compared with the C group. Immunohistochemistry showed increased expression of nuclear factor kB, substance P, vascular endothelial growth factor and neuronal nitric oxide synthase in the LN group, while expression of the protein gene product 9.5 was decreased. l-NAME alters cell morphology and the expression of extracellular matrix molecules in the CB and carotid glomus in rats with l-NAME-induced hypertension. PMID:21899859

  10. Presynaptic action of adenosine on a 4-aminopyridine-sensitive current in the rat carotid body

    PubMed Central

    Vandier, C; Conway, A F; Landauer, R C; Kumar, P

    1999-01-01

    Plasma adenosine concentration increases during hypoxia to a level that excites carotid body chemoreceptors by an undetermined mechanism. We have examined this further by determining the electrophysiological responses to exogenous adenosine of sinus nerve chemoafferents in vitro and of whole-cell currents in isolated type I cells.Steady-state, single-fibre chemoafferent discharge was increased approximately 5-fold above basal levels by 100 μM adenosine. This adenosine-stimulated discharge was reversibly and increasingly reduced by methoxyverapamil (D600, 100 μM), by application of nickel chloride (Ni2+, 2 mM) and by removal of extracellular Ca2+. These effects strongly suggest a presynaptic, excitatory action of adenosine on type I cells of the carotid body.Adenosine decreased whole-cell outward currents at membrane potentials above -40 mV in isolated type I cells recorded during superfusion with bicarbonate-buffered saline solution at 34–36 °C. This effect was reversible and concentration dependent with a maximal effect at 10 μM.The degree of current inhibition induced by 10 μM adenosine was voltage independent (45.39 ± 2.55% (mean ± s.e.m.) between −40 and +30 mV) and largely (∼75%), but not entirely, Ca2+ independent. 4-Aminopyridine (4-AP, 5 mM) decreased the amplitude of the control outward current by 80.60 ± 3.67% and abolished the effect of adenosine.Adenosine was without effect upon currents near the resting membrane potential of approximately −55 mV and did not induce depolarization in current-clamp experiments.We conclude that adenosine acts to inhibit a 4-AP-sensitive current in isolated type I cells of the rat carotid body and suggest that this mechanism contributes to the chemoexcitatory effect of adenosine in the whole carotid body. PMID:10050009

  11. Carotid body chemoreceptors, sympathetic neural activation, and cardiometabolic disease.

    PubMed

    Iturriaga, Rodrigo; Del Rio, Rodrigo; Idiaquez, Juan; Somers, Virend K

    2016-01-01

    The carotid body (CB) is the main peripheral chemoreceptor that senses the arterial PO2, PCO2 and pH. In response to hypoxemia, hypercapnia and acidosis, carotid chemosensory discharge elicits reflex respiratory, autonomic and cardiovascular adjustments. The classical construct considers the CB as the main peripheral oxygen sensor, triggering reflex physiological responses to acute hypoxemia and facilitating the ventilatory acclimation to chronic hypoxemia at high altitude. However, a growing body of experimental evidence supports the novel concept that an abnormally enhanced CB chemosensory input to the brainstem contributes to overactivation of the sympathetic nervous system, and consequent pathology. Indeed, the CB has been implicated in several diseases associated with increases in central sympathetic outflow. These include hypertension, heart failure, sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. Indeed, ablation of the CB has been proposed for the treatment of severe and resistant hypertension in humans. In this review, we will analyze and discuss new evidence supporting an important role for the CB chemoreceptor in the progression of autonomic and cardiorespiratory alterations induced by heart failure, obstructive sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. PMID:26920146

  12. Regulation of carotid body oxygen sensing by hypoxia-inducible factors.

    PubMed

    Prabhakar, Nanduri R; Semenza, Gregg L

    2016-01-01

    Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Carotid body responses to hypoxia are not uniform but instead exhibit remarkable inter-individual variations. The molecular mechanisms underlying variations in carotid body O2 sensing are not known. Hypoxia-inducible factor-1 (HIF-1) and HIF-2 mediate transcriptional responses to hypoxia. This article reviews the emerging evidence that proper expression of the HIF-α isoforms is a key molecular determinant for carotid body O2 sensing. HIF-1α deficiency leads to a blunted carotid body hypoxic response, which is due to increased abundance of HIF-2α, elevated anti-oxidant enzyme activity, and a reduced intracellular redox state. Conversely, HIF-2α deficiency results in augmented carotid body sensitivity to hypoxia, which is due to increased abundance of HIF-1α, elevated pro-oxidant enzyme activity, and an oxidized intracellular redox state. Double heterozygous mice with equally reduced HIF-1α and HIF-2α showed no abnormality in redox state or carotid body O2 sensing. Thus, mutual antagonism between HIF-α isoforms determines the redox state and thereby establishes the set point for hypoxic sensing by the carotid body. PMID:26265380

  13. Dual effects of nitric oxide on cat carotid body chemoreception.

    PubMed

    Iturriaga, R; Villanueva, S; Mosqueira, M

    2000-09-01

    We studied the effects of nitric oxide (NO) released by NO donors on cat carotid body (CB) chemosensory activity during normoxia and hypoxia. CBs excised from pentobarbital sodium-anaesthetized cats were perfused with Tyrode at 38 degrees C and pH 7.40. The frequency of chemosensory discharges (f(x)) was recorded from the carotid sinus nerve, and changes of NO concentration were measured by a chronoamperometric technique, with NO-selective carbon-fiber microelectrodes inserted in the CB. During steady chemosensory excitation induced by hypoxia, bolus injections of NO (DeltaNO = 0. 5-12 microM), released by S-nitroso-N-acetylpenicillamine (SNAP) and 6-(2-hydroxy-1-methyl-nitrosohydrazino)-N-methyl-1-hexanamine++ + (NOC-9), transiently reduced f(x) in a dose-dependent manner. However, during normoxia, the same concentration of NO (DeltaNO = 0. 5-13 microM) released by the NO donors increased f(x) in a dose-dependent manner. The present results show a dual effect of NO on CB chemoreception that is dependent on the PO(2) levels. During hypoxia, NO is predominantly an inhibitor of chemoreception, whereas, in normoxia, NO increased f(x). The mechanisms by which NO produces chemosensory excitation during normoxia remain to be determined. PMID:10956344

  14. Progression of carotid-artery disease in type 2 diabetic patients: a cohort prospective study.

    PubMed

    Bosevski, Marijan; Stojanovska, Lily

    2015-01-01

    In order to assess the progression of carotid-artery disease in type 2 diabetic cohort (n=207 patients), the dynamic change in carotid intima-media thickness (CIMT) and the occurrence of plaques were followed for a period of 31.35±10.59 months. The mean CIMT at the beginning of the study was 0.9178±0.1447 mm, with a maximal value of 1.1210±0.2366 mm. The maximal value of CIMT changed by 0.07 mm/year. Progression of CIMT was noted in 86.8% and its regression in 7.8% of patients. The occurrence of carotid plaques was detected in 41.8% of patients. Multiple regression analysis revealed the maximal value of CIMT to be associated with diastolic blood pressure, despite mean CIMT being predicted by body mass index. The presence of peripheral arterial disease and hypo-high-density lipoproteinemia were found to be predictors for the occurrence of carotid plaques. Our data have clinical implications in predicting risk factors for the progression of carotid-artery disease in type 2 diabetic patients for their appropriate management. PMID:26527880

  15. Progression of carotid-artery disease in type 2 diabetic patients: a cohort prospective study

    PubMed Central

    Bosevski, Marijan; Stojanovska, Lily

    2015-01-01

    In order to assess the progression of carotid-artery disease in type 2 diabetic cohort (n=207 patients), the dynamic change in carotid intima-media thickness (CIMT) and the occurrence of plaques were followed for a period of 31.35±10.59 months. The mean CIMT at the beginning of the study was 0.9178±0.1447 mm, with a maximal value of 1.1210±0.2366 mm. The maximal value of CIMT changed by 0.07 mm/year. Progression of CIMT was noted in 86.8% and its regression in 7.8% of patients. The occurrence of carotid plaques was detected in 41.8% of patients. Multiple regression analysis revealed the maximal value of CIMT to be associated with diastolic blood pressure, despite mean CIMT being predicted by body mass index. The presence of peripheral arterial disease and hypo-high-density lipoproteinemia were found to be predictors for the occurrence of carotid plaques. Our data have clinical implications in predicting risk factors for the progression of carotid-artery disease in type 2 diabetic patients for their appropriate management. PMID:26527880

  16. Biophysical studies of the cellular elements of the rabbit carotid body.

    PubMed

    Duchen, M R; Caddy, K W; Kirby, G C; Patterson, D L; Ponte, J; Biscoe, T J

    1988-07-01

    The carotid body is a major sensor of oxygen partial pressure in the arterial blood, and plays a role in the control of respiration. Despite extensive investigation of the structure, the cellular basis of the transduction mechanism remains poorly understood. We have developed a preparation of freshly dissociated cells from the rabbit carotid body, in which two cell types may be identified using morphological criteria. The preparation allows application of the patch clamp technique to characterize the properties of the cells which have otherwise proved difficult to study in situ. Carotid bodies of rabbits were dissociated using a combination of enzymatic and mechanical procedures. The dissociated preparation obtained consisted of clusters of spherical or ovoid cells of 12-15 microns in diameter and a distinct population of spherical cells of 8-10 microns diameter. Electron microscopic techniques were used to identify the cells present in the preparation. Again two populations of cells could be distinguished. A population of cells 10-12 microns in diameter, often found in clusters, possessed the dense-cored vesicles characteristic of Type I cells, while a population of smaller cells (diameter 5-7 microns) had peripherally condensed nuclear chromatin and fine cytoplasmic surface extensions characteristic of Type II cells. Patch clamp study of the cells showed that they represent two electrophysiologically distinct populations. The larger cells, corresponding to Type I cells, were found to be excitable, generating fast, sodium-dependent action potentials that were recorded both in the cell attached and whole cell recording configurations. The smaller Type II cells did not generate action potentials. Voltage clamp study of Type I cells allowed definition of a range of voltage-gated currents. These included an inactivating, tetrodotoxin-sensitive inward sodium current, a high threshold sustained inward calcium current, and outward potassium currents. A component of the

  17. Revelations about carotid body function through its pathological role in resistant hypertension.

    PubMed

    Paton, Julian F R; Ratcliffe, Laura; Hering, Dagmara; Wolf, Jacek; Sobotka, Paul A; Narkiewicz, Krzysztof

    2013-08-01

    Much recent attention has been given to the carotid body because of its potential role in cardiovascular disease states. One disease, neurogenic hypertension, characterised by excessive sympathetic activity, appears dependent on carotid body activity that may or may not be accompanied by sleep-disordered breathing. Herein, we review recent literature suggesting that the carotid body acquires tonicity in hypertension. We predict that carotid glomectomy will be a powerful way to temper excessive sympathetic discharge in diseases such as hypertension. We propose a model to explain that signalling from the 'hypertensive' carotid body is tonic, and hypothesise that there will be a sub-population of glomus cells that channel separately into reflex pathways controlling sympathetic motor outflows. PMID:23828147

  18. Cerebral foreign body reaction after carotid aneurysm stenting.

    PubMed

    Lorentzen, Anastasia Orlova; Nome, Terje; Bakke, Søren Jacob; Scheie, David; Stenset, Vidar; Aamodt, Anne Hege

    2016-02-01

    Flow diverter stents are new important tools in the treatment of large, giant, or wide-necked aneurysms. Their delivery and positioning may be difficult due to vessel tortuosity. Common adverse events include intracranial hemorrhage and ischemic stroke, which usually occurs within the same day, or the next few days after the procedure. We present a case where we encountered an unusual intracerebral complication several months after endovascular treatment of a large left internal carotid artery aneurysm, and where brain biopsy revealed foreign body reaction to hydrophilic polymer fragments distally to the stent site. Although previously described, embolization of polymer material from intravascular equipment is rare. We could not identify any other biopsy verified case in the literature, with this particular presentation of intracerebral polymer embolization--a multifocal inflammation spread out through the white matter of one hemisphere without hemorrhage or ischemic changes. PMID:26510943

  19. KISS1 and KISS1R expression in the human and rat carotid body and superior cervical ganglion.

    PubMed

    Porzionato, A; Fenu, G; Rucinski, M; Macchi, V; Montella, A; Malendowicz, L K; De Caro, R

    2011-01-01

    KISS1 and its receptor, KISS1R, have both been found to be expressed in central nervous system, but few data are present in the literature about their distribution in peripheral nervous structures. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of KISS1 and KISS1R in the rat and human carotid bodies and superior cervical ganglia, also with particular reference to the different cellular populations. Materials consisted of carotid bodies and superior cervical ganglia were obtained at autopsy from 10 adult subjects and sampled from 10 adult Sprague-Dawley rats. Immunohistochemistry revealed diffuse expression of KISS1 and KISS1R in type I cells of both human and rat carotid bodies, whereas type II cells were negative. In both human and rat superior cervical ganglia positive anti-KISS1 and -KISS1R immunostainings were also selectively found in ganglion cells, satellite cells being negative. Endothelial cells also showed moderate immunostaining for both KISS1 and KISS1R. The expression of both kisspeptins and kisspeptin receptors in glomic type I cells and sympathetic ganglion cells supports a modulatory role of KISS1 on peripheral chemoreception and sympathetic function. Moreover, local changes in blood flow have been considered to be involved in carotid body chemoreceptor discharge and kisspeptins and kisspeptin receptors have also been found in the endothelial cells. As a consequence, a possible role of kisspeptins in the regulation of carotid body blood flow and, indirectly, in chemoreceptor discharge may also be hypothesized. PMID:22193294

  20. KISS1 and KISS1R expression in the human and rat carotid body and superior cervical ganglion

    PubMed Central

    Porzionato, A.; Fenu, G.; Rucinski, M.; Macchi, V.; Montella, A.; Malendowicz, L.K.; De Caro, R.

    2011-01-01

    KISS1 and its receptor, KISS1R, have both been found to be expressed in central nervous system, but few data are present in the literature about their distribution in peripheral nervous structures. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of KISS1 and KISS1R in the rat and human carotid bodies and superior cervical ganglia, also with particular reference to the different cellular populations. Materials consisted of carotid bodies and superior cervical ganglia were obtained at autopsy from 10 adult subjects and sampled from 10 adult Sprague-Dawley rats. Immunohistochemistry revealed diffuse expression of KISS1 and KISS1R in type I cells of both human and rat carotid bodies, whereas type II cells were negative. In both human and rat superior cervical ganglia positive anti-KISS1 and -KISS1R immunostainings were also selectively found in ganglion cells, satellite cells being negative. Endothelial cells also showed moderate immunostaining for both KISS1 and KISS1R. The expression of both kisspeptins and kisspeptin receptors in glomic type I cells and sympathetic ganglion cells supports a modulatory role of KISS1 on peripheral chemoreception and sympathetic function. Moreover, local changes in blood flow have been considered to be involved in carotid body chemoreceptor discharge and kisspeptins and kisspeptin receptors have also been found in the endothelial cells. As a consequence, a possible role of kisspeptins in the regulation of carotid body blood flow and, indirectly, in chemoreceptor discharge may also be hypothesized. PMID:22193294

  1. Angiotensin AT1 receptor-mediated excitation of rat carotid body chemoreceptor afferent activity.

    PubMed

    Allen, A M

    1998-08-01

    1. A high density of angiotensin II receptors was observed in the rat carotid body by in vitro autoradiography employing 125I-[Sar1, Ile8]-angiotensin II as radioligand. Displacement studies demonstrated that the receptors were of the AT1 subtype. 2. The binding pattern indicated that the AT1 receptors occurred over clumps of glomus cells, the principal chemoreceptor cell of the carotid body. Selective lesions of the sympathetic or afferent innervation of the carotid body had little effect on the density of receptor binding, demonstrating that the majority of AT1 receptors were intrinsic to the glomus cells. 3. To determine the direct effect of angiotensin II on chemoreceptor function, without the confounding effects of the vasoconstrictor action of angiotensin II, carotid sinus nerve activity was recorded from the isolated carotid body in vitro. The carotid body was superfused with Tyrode solution saturated with carbogen (95 % O2, 5 % CO2), maintained at 36 C, and multi-unit nerve activity recorded with a suction electrode. 4. Angiotensin II elicited a dose-dependent excitation of carotid sinus nerve activity (maximum increase of 36 +/- 11 % with 10 nM angiotensin II) with a threshold concentration of 1 nM. The response was blocked by the addition of an AT1 receptor antagonist, losartan (1 microM), but not by the addition of an AT2 receptor antagonist, PD123319 (1 microM). 5. In approximately 50 % of experiments the excitation was preceded by an inhibition of activity (maximum decrease of 24 +/- 8 % with 10 nM angiotensin II). This inhibitory response was markedly attenuated by losartan but not affected by PD123319. 6. These observations demonstrate that angiotensin II, acting through AT1 receptors located on glomus cells in the carotid body, can directly alter carotid chemoreceptor afferent activity. This provides a means whereby humoral information about fluid and electrolyte homeostasis might influence control of cardiorespiratory function. PMID:9660892

  2. Angiotensin AT1 receptor-mediated excitation of rat carotid body chemoreceptor afferent activity

    PubMed Central

    Allen, A M

    1998-01-01

    A high density of angiotensin II receptors was observed in the rat carotid body by in vitro autoradiography employing 125I-[Sar1,Ile8]-angiotensin II as radioligand. Displacement studies demonstrated that the receptors were of the AT1 subtype.The binding pattern indicated that the AT1 receptors occurred over clumps of glomus cells, the principal chemoreceptor cell of the carotid body. Selective lesions of the sympathetic or afferent innervation of the carotid body had little effect on the density of receptor binding, demonstrating that the majority of AT1 receptors were intrinsic to the glomus cells.To determine the direct effect of angiotensin II on chemoreceptor function, without the confounding effects of the vasoconstrictor action of angiotensin II, carotid sinus nerve activity was recorded from the isolated carotid body in vitro. The carotid body was superfused with Tyrode solution saturated with carbogen (95% O2, 5% CO2), maintained at 36 °C, and multi-unit nerve activity recorded with a suction electrode.Angiotensin II elicited a dose-dependent excitation of carotid sinus nerve activity (maximum increase of 36 ± 11% with 10 nm angiotensin II) with a threshold concentration of 1 nm. The response was blocked by the addition of an AT1 receptor antagonist, losartan (1 μm), but not by the addition of an AT2 receptor antagonist, PD123319 (1 μm).In approximately 50% of experiments the excitation was preceded by an inhibition of activity (maximum decrease of 24 ± 8% with 10 nm angiotensin II). This inhibitory response was markedly attenuated by losartan but not affected by PD123319.These observations demonstrate that angiotensin II, acting through AT1 receptors located on glomus cells in the carotid body, can directly alter carotid chemoreceptor afferent activity. This provides a means whereby humoral information about fluid and electrolyte homeostasis might influence control of cardiorespiratory function. PMID:9660892

  3. Magnetic resonance and computed tomography imaging of a carotid body tumor in a dog

    PubMed Central

    2012-01-01

    A 5-year-old castrated male Labrador Retriever was presented to a referring veterinarian for a swelling in the neck region. Based on the results of histopathology, a carotid body tumor, was diagnosed. The dog was referred to a medical imaging unit for further staging and follow up. This report describes the magnetic resonance (MR) and computed tomographic (CT) appearance of a carotid body tumor. PMID:22507757

  4. The Carotid Body and Arousal in the Fetus and Neonate

    PubMed Central

    2012-01-01

    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 CO2. 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 CO2 in the fetus and newborn and will outline what we know (and don’t know) about the involvement of the carotid body in this process. PMID:22684039

  5. Effects of specific carotid body and brain hypoxia on respiratory muscle control in the awake goat.

    PubMed Central

    Smith, C A; Engwall, M J; Dempsey, J A; Bisgard, G E

    1993-01-01

    1. We assessed the effects of specific brain hypoxia on the control of inspiratory and expiratory muscle electromyographic (EMG) activities in response to specific carotid body hypoxia in seven awake goats. We used an isolated carotid body perfusion technique that permitted specific, physiological, steady-state stimulation of the carotid bodies or maintenance of normoxia and normocapnia at the carotid bodies while varying the level of systemic, and therefore, brain oxygenation. 2. Isolated brain normocapnic hypoxia of up to 1.5 h duration increased inspired minute ventilation (VI) by means of increases in both tidal volume (VT) and respiratory frequency (fR). Electromyographic activities of both inspiratory and expiratory muscles were augmented as well. These responses were similar to those produced by low levels of whole-body normoxic hypercapnia. We conclude that moderate levels of brain hypoxia (Pa,O2 approximately 40 mmHg) in awake goats caused a net stimulation of ventilatory motor output. 3. Hypoxic stimulation of the carotid bodies alone caused comparable increases in VT and fR, and EMG augmentation of both inspiratory and expiratory muscles whether the brain was hypoxic or normoxic. These responses were quite similar to those obtained over a wide range of whole-body normoxic hypercapnia. We conclude that the integration of carotid body afferent information is not affected by moderate brain hypoxia in awake goats. 4. We found no evidence for an asymmetrical recruitment pattern of inspiratory vs. expiratory muscles in response to carotid body hypoxia or in response to brain hypoxia alone. 5. Our data support the concept that moderate brain hypoxia results in a net stimulation of respiratory motor output. These findings question the significance of 'central hypoxic depression' to the regulation of breathing under physiological levels of hypoxaemia in the awake animal. PMID:8487210

  6. Carotid body potentiation during chronic intermittent hypoxia: implication for hypertension.

    PubMed

    Del Rio, Rodrigo; Moya, Esteban A; Iturriaga, Rodrigo

    2014-01-01

    Autonomic dysfunction is involved in the development of hypertension in humans with obstructive sleep apnea, and animals exposed to chronic intermittent hypoxia (CIH). It has been proposed that a crucial step in the development of the hypertension is the potentiation of the carotid body (CB) chemosensory responses to hypoxia, but the temporal progression of the CB chemosensory, autonomic and hypertensive changes induced by CIH are not known. We tested the hypothesis that CB potentiation precedes the autonomic imbalance and the hypertension in rats exposed to CIH. Thus, we studied the changes in CB chemosensory and ventilatory responsiveness to hypoxia, the spontaneous baroreflex sensitivity (BRS), heart rate variability (HRV) and arterial blood pressure in pentobarbital anesthetized rats exposed to CIH for 7, 14, and 21 days. After 7 days of CIH, CB chemosensory and ventilatory responses to hypoxia were enhanced, while BRS was significantly reduced by 2-fold in CIH-rats compared to sham-rats. These alterations persisted until 21 days of CIH. After 14 days, CIH shifted the HRV power spectra suggesting a predominance of sympathetic over parasympathetic tone. In contrast, hypertension was found after 21 days of CIH. Concomitant changes between the gain of spectral HRV, BRS, and ventilatory hypoxic chemoreflex showed that the CIH-induced BRS attenuation preceded the HRV changes. CIH induced a simultaneous decrease of the BRS gain along with an increase of the hypoxic ventilatory gain. Present results show that CIH-induced persistent hypertension was preceded by early changes in CB chemosensory control of cardiorespiratory and autonomic function. PMID:25429271

  7. Role of the carotid bodies in chemosensory ventilatory responses in the anesthetized mouse.

    PubMed

    Izumizaki, Masahiko; Pokorski, Mieczyslaw; Homma, Ikuo

    2004-10-01

    We examined the effects of carotid body denervation on ventilatory responses to normoxia (21% O2 in N2 for 240 s), hypoxic hypoxia (10 and 15% O2 in N2 for 90 and 120 s, respectively), and hyperoxic hypercapnia (5% CO2 in O2 for 240 s) in the spontaneously breathing urethane-anesthetized mouse. Respiratory measurements were made with a whole body, single-chamber plethysmograph before and after cutting both carotid sinus nerves. Baseline measurements in air showed that carotid body denervation was accompanied by lower minute ventilation with a reduction in respiratory frequency. On the basis of measurements with an open-circuit system, no significant differences in O2 consumption or CO2 production before and after chemodenervation were found. During both levels of hypoxia, animals with intact sinus nerves had increased respiratory frequency, tidal volume, and minute ventilation; however, after chemodenervation, animals experienced a drop in respiratory frequency and ventilatory depression. Tidal volume responses during 15% hypoxia were similar before and after carotid body denervation; during 10% hypoxia in chemodenervated animals, there was a sudden increase in tidal volume with an increase in the rate of inspiration, suggesting that gasping occurred. During hyperoxic hypercapnia, ventilatory responses were lower with a smaller tidal volume after chemodenervation than before. We conclude that the carotid bodies are essential for maintaining ventilation during eupnea, hypoxia, and hypercapnia in the anesthetized mouse. PMID:15194670

  8. 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

  9. Evidence for a carotid body homolog in the lizard Tupinambis merianae.

    PubMed

    Reichert, Michelle N; Brink, Deidre L; Milsom, William K

    2015-01-15

    The homolog to the mammalian carotid body has not yet been identified in lizards. Observational studies and evolutionary history provide indirect evidence for the existence of a chemoreceptor population at the first major bifurcation of the common carotid artery in lizards, but a chemoreceptive role for this area has not yet been definitively demonstrated. We explored this possibility by measuring changes in cardiorespiratory variables in response to focal arterial injections of the hypoxia mimic sodium cyanide (NaCN) into the carotid artery of 12 unanesthetized specimens of Tupinambis merianae. These injections elicited increases in heart rate (f(H); 101±35% increase) and respiratory rate (f(R); 620±119% increase), but not mean arterial blood pressure (MAP). These responses were eliminated by vagal denervation. Similar responses were elicited by injections of the neurotransmitters acetylcholine (ACh) and serotonin (5-HT) but not norepinephrine. Heart rate and respiratory rate increases in response to NaCN could be blocked or reduced by antagonists to ACh (atropine) and/or 5-HT (methysergide). Finally, using immunohistochemistry, we demonstrate the presence of putative chemoreceptive cells immunopositive for the cholinergic cell marker vesicular ACh transporter (VAChT) and 5-HT on internal lattice-like structures at the carotid bifurcation. These results provide evidence in lizards for the existence of dispersed chemoreceptor cells at the first carotid bifurcation in the central cardiovascular area that have similar properties to known carotid body homologs, adding to the picture of chemoreceptor evolution in vertebrates. PMID:25524981

  10. Carotid baroreceptor influence on forearm vascular resistance during low level lower body negative pressure

    NASA Technical Reports Server (NTRS)

    Thompson, Cynthia A.; Ludwig, David A.; Convertino, Victor A.

    1991-01-01

    The degree of forearm vasoconstriction induced by low levels of lower body negative pressure (LBNP) provides a measure of the responsiveness of the cardiopulmonary baroreflex. The validity of this measurement is based on the assumption that this vasoconstriction response is not influenced by unloading of carotid baroreceptors. To test the hypothesis that arterial baroreceptor unloading does not alter the degree of forearm vascular resistance during low levels of LBNP, 12 subjects were exposed to -15 and -20 mm Hg LBNP with and without additional artificial (+ 10 mm Hg neck pressure) unloading of the carotid baroreceptors. There was no measurable influence of carotid unloading on forearm vascular resistance at either level of LBNP. It is concluded that forearm vascular resistance measured during cardiopulmonary baroreceptor unloading is unaffected by carotid baroreceptor unloading within the magnitude encountered during low levels of LBNP.

  11. Carotid body overactivity induces respiratory neurone channelopathy contributing to neurogenic hypertension.

    PubMed

    Moraes, Davi J A; Machado, Benedito H; Paton, Julian F R

    2015-07-15

    Why sympathetic activity rises in neurogenic hypertension remains unknown. It has been postulated that changes in the electrical excitability of medullary pre-sympathetic neurones are the main causal mechanism for the development of sympathetic overactivity in experimental hypertension. Here we review recent data suggesting that enhanced sympathetic activity in neurogenic hypertension is, at least in part, dependent on alterations in the electrical excitability of medullary respiratory neurones and their central modulation of sympatho-excitatory networks. We also present results showing a critical role for carotid body tonicity in the aetiology of enhanced central respiratory modulation of sympathetic activity in neurogenic hypertension. We propose a novel hypothesis of respiratory neurone channelopathy induced by carotid body overactivity in neurogenic hypertension that may contribute to sympathetic excess. Moreover, our data support the notion of targeting the carotid body as a potential novel therapeutic approach for reducing sympathetic vasomotor tone in neurogenic hypertension. PMID:25900825

  12. Thermal effects on ventilation in cats: participation of carotid body chemoreceptors.

    PubMed

    Fadic, R; Larrain, C; Zapata, P

    1991-10-01

    In pentobarbitone anesthetized cats, raising body temperature from 37 to 40 degrees C by external heat increased respiratory frequency, tidal volume, frequency of spontaneous gasps and mean inspiratory flow. It reduced end-tidal CO2 pressure, together with inspiratory and expiratory durations. After bilateral section of the carotid nerves, raising body temperature still induced hyperventilation, but the increase in gasp frequency was less pronounced and no significant change in tidal volume was observed. In comparison to steady ventilatory values in the intact condition, significant reductions in tidal volume at 38 degrees C and in gasp frequency at 37, 39 and 40 degrees C were observed after bilateral carotid neurotomy. Brief hyperoxic tests induced transient decreases in tidal volume and increases in end-tidal CO2 pressure which were significantly larger at 40 degrees C than at 37 degrees C. These changes disappeared after bilateral carotid neurotomy. Anesthetic block of both carotid nerves produced transient reductions in tidal volume at any given temperature. We conclude that carotid body afferents contribute to the hyperventilation evoked by hyperthermia. After their interruption, such contribution is replaceable from other thermal afferents. PMID:1759053

  13. Inherent variations in CO-H2S-mediated carotid body O2 sensing mediate hypertension and pulmonary edema.

    PubMed

    Peng, Ying-Jie; Makarenko, Vladislav V; Nanduri, Jayasri; Vasavda, Chirag; Raghuraman, Gayatri; Yuan, Guoxiang; Gadalla, Moataz M; Kumar, Ganesh K; Snyder, Solomon H; Prabhakar, Nanduri R

    2014-01-21

    Oxygen (O2) sensing by the carotid body and its chemosensory reflex is critical for homeostatic regulation of breathing and blood pressure. Humans and animals exhibit substantial interindividual variation in this chemosensory reflex response, with profound effects on cardiorespiratory functions. However, the underlying mechanisms are not known. Here, we report that inherent variations in carotid body O2 sensing by carbon monoxide (CO)-sensitive hydrogen sulfide (H2S) signaling contribute to reflex variation in three genetically distinct rat strains. Compared with Sprague-Dawley (SD) rats, Brown-Norway (BN) rats exhibit impaired carotid body O2 sensing and develop pulmonary edema as a consequence of poor ventilatory adaptation to hypobaric hypoxia. Spontaneous Hypertensive (SH) rat carotid bodies display inherent hypersensitivity to hypoxia and develop hypertension. BN rat carotid bodies have naturally higher CO and lower H2S levels than SD rat, whereas SH carotid bodies have reduced CO and greater H2S generation. Higher CO levels in BN rats were associated with higher substrate affinity of the enzyme heme oxygenase 2, whereas SH rats present lower substrate affinity and, thus, reduced CO generation. Reducing CO levels in BN rat carotid bodies increased H2S generation, restoring O2 sensing and preventing hypoxia-induced pulmonary edema. Increasing CO levels in SH carotid bodies reduced H2S generation, preventing hypersensitivity to hypoxia and controlling hypertension in SH rats. PMID:24395806

  14. Role of. alpha. sub 2 -adrenergic receptors in the carotid body response to hypoxia

    SciTech Connect

    Kou, Y.R.; Ernsberger, P.; Cherniack, N.S.; Prabhakar, N.R. )

    1990-02-26

    Clonidine, which acts in part as an {alpha}{sub 2}-adrenergic receptor agonist, depresses ventilation. The authors examined the role of {alpha}{sub 2}-receptors in carotid chemoreceptor activity. The density of {alpha}{sub 2}-receptors was determined in membrane fractions of 18 cat carotid bodies using {sup 125}I-iodoclonidine with 0.1 mM epinephrine or 10 {mu}M SKF-86466 defining nonspecific binding. {alpha}{sub 2}-Adrenergic receptor density averaged 0.6{plus minus}0.1 fmol/carotid body (mean {plus minus} SEM) and was comparable to other sympathetic target tissues. The authors then studied the effects of an agonist (guanabenz) and an antagonist (SKF-86466; 6-Cl-N-methyl-2,3,4,5-tetrahydro-1-H3-benzazepine) specific for {alpha}{sub 2}-receptors on baseline and hypoxia-stimulated carotid body discharge, in 10 anesthetized, paralyzed and artificially ventilated cats. Intracarotid infusion of guanabenz for 5 minutes caused a dose-dependent depression of the baseline activity and reduced the chemoreceptor response to hypoxia by 88.0{plus minus}5.8% of the vehicle-injected controls. Intravenous administration of SKF-86466 reversed the effects of guanabenz on the carotid body activity. in contrast, chemoreceptor depression caused by dopamine was unaffected by SKF-86466. SKF-86466 alone increased baseline discharge and potentiated the chemoreceptor response to hypoxia by 34.0 {plus minus} 9.6% of the controls. These results demonstrate that {alpha}{sub 2}-adrenergic receptors are present in the cat carotid body and they exert an inhibitory influence on the chemoreceptor response to hypoxia.

  15. Towards the Sensory Nature of the Carotid Body: Hering, De Castro and Heymans†

    PubMed Central

    de Castro, Fernando

    2009-01-01

    The carotid body or glomus caroticum is a chemosensory organ bilaterally located between the external and internal carotid arteries. Although known by anatomists since the report included by Von Haller and Taube in the mid XVIII century, its detailed study started the first quarter of the XX. The Austro-German physiologist Heinrich E. Hering studied the cardio-respiratory reflexes searched for the anatomical basis of this reflex in the carotid sinus, while the Ghent School leaded by the physio-pharmacologists Jean-François Heymans and his son Corneille focussed in the cardio-aortic reflexogenic region. In 1925, Fernando De Castro, one of the youngest and more brilliant disciples of Santiago Ramón y Cajal at the Laboratorio de Investigaciones Biológicas (Madrid, Spain), profited from some original novelties in histological procedures to study the fine structure and innervation of the carotid body. De Castro unravelled them in a series of scientific papers published between 1926 and 1929, which became the basis to consider the carotid body as a sensory receptor (or chemoreceptor) to detect the chemical changes in the composition of the blood. Indeed, this was the first description of arterial chemoreceptors. Impressed by the novelty and implications of the work of De Castro, Corneille Heymans invited the Spanish neurologist to visit Ghent on two occasions (1929 and 1932), where both performed experiences together. Shortly after, Heymans visited De Castro at the Instituto Cajal (Madrid). From 1932 to 1933, Corneille Heymans focused all his attention on the carotid body his physiological demonstration of De Castro's hypothesis regarding chemoreceptors was awarded with the Nobel Prize in Physiology or Medicine in 1938, just when Spain was immersed in its catastrophic Civil War. PMID:20057927

  16. Immunohistochemical localization of dopamine D2 receptor in the rat carotid body.

    PubMed

    Wakai, Jun; Takayama, Anna; Yokoyama, Takuya; Nakamuta, Nobuaki; Kusakabe, Tatsumi; Yamamoto, Yoshio

    2015-10-01

    Dopamine modulates the chemosensitivity of arterial chemoreceptors, and dopamine D2 receptor (D2R) is expected to localize in the glomus cells and/or sensory nerve endings of the carotid body. In the present study, the localization of D2R in the rat carotid body was examined using double immunofluorescence for D2R with various cell markers. D2R immunoreactivity was mainly localized in glomus cells immunoreactive to tyrosine hydroxylase or dopamine β-hydroxylase (DBH), but not in S100B-immunoreactive sustentacular cells. Furthermore, D2R immunoreactivity was observed in petrosal ganglion cells and nerve bundles in the carotid body, but not in the nerve endings with P2X2 immunoreactivity. In the carotid ganglion, a few punctate D2R-immunoreactive products were detected in DBH-immunoreactive nerve cell bodies. These results showed that D2R was mainly distributed in glomus cells, and suggested that D2R plays a role in the inhibitory modulation of chemosensory activity in a paracrine and/or autocrine manner. PMID:26272445

  17. Carotid Body Chemoreflex Mediates Intermittent Hypoxia-Induced Oxidative Stress in the Adrenal Medulla

    PubMed Central

    Kumar, Ganesh K.; Peng, Ying-Jie; Nanduri, Jayasri; Prabhakar, Nanduri R.

    2016-01-01

    Intermittent hypoxia (IH) increases reactive oxygen species generation resulting in oxidative stress in the adrenal medulla (AM), a major end-organ of the sympathetic nervous system which facilitates catecholamine secretion by hypoxia. Here, we show that carotid body chemoreflex contributes to IH-induced oxidative stress in the AM. Carotid bodies were ablated by cryocoagulation of glomus cells, the putative O2 sensing cells. Carotid body ablated (CBA) and control rats were exposed to IH and the redox state of the AM was assessed biochemically. We found that IH raised reactive oxygen species levels along with an increase in NADPH oxidase (Nox), a pro-oxidant enzyme and a decrease in superoxide dismutase-2 (SOD2), an anti-oxidant enzyme. Further, IH increased hypoxia-inducible factor (HIF)-1α, whereas decreased HIF-2α, the transcriptional regulator of Nox and SOD-2, respectively. These IH-induced changes in the AM were absent in CBA rats. Moreover, IH increased splanchnic nerve activity and facilitated hypoxia-evoked catecholamine efflux from the AM and CBA prevented these effects. These findings suggest that IH-induced oxidative stress and catecholamine efflux in the AM occurs via carotid body chemoreflex involving HIF α isoform mediated imbalance in pro-, and anti-oxidant enzymes. PMID:26303481

  18. A case of congenital agenesis of the common carotid artery associated with an ectopic parathyroid adenoma mimicking a carotid body tumor.

    PubMed

    Malm, Ian-James; Olcott, Clara M; Chan, Jason Y K; Loyo, Myriam; Kim, Young J

    2013-01-01

    Ectopic parathyroid adenomas can be encountered during four gland explorations, but nearly 80% of adenomas are localized with ultrasound and sestamibi imaging. Ectopic adenomas are thought to arise from abnormal migration during development. As a cervical congenital anomaly, common carotid artery agenesis is an extremely rare anomaly characterized by separate origins of the internal and external carotid arteries directly from the aortic arch. Here we present a case of a 75 year old man with primary hyperparathyroidism who was found to have congenital agenesis of the common carotid artery associated with an ectopic parathyroid adenoma within the parapharyngeal space, which mimicked a carotid body tumor based on location and imaging. The successful identification and resection of the ectopic parathyroid adenoma presented here demonstrate the importance of preoperative imaging studies to allow appropriate operative planning as well as the utility of intraoperative parathyroid hormone assay in predicting cure during surgery. PMID:23993711

  19. 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.

  20. Multidisciplinary Management of Carotid Body Tumors in a Tertiary Urban Institution

    PubMed Central

    Galyfos, George; Stamatatos, Ioannis; Kerasidis, Stavros; Stefanidis, Ioannis; Giannakakis, Sotirios; Kastrisios, Georgios; Geropapas, Georgios; Papacharalampous, Gerasimos; Maltezos, Chrisostomos

    2015-01-01

    Objective. Aim of this study is to present the experience of our institution in carotid body tumors (CBTs) treatment. Methods. All cases treated in a Vascular Surgery Department within 2.5 years (03/2013–09/2015) were retrospectively evaluated. Demographics, diagnostic, and treatment strategy were recorded. All patients with known CBT underwent ultrasound and magnetic resonance imaging preoperatively. All cases were classified according to the Shamblin type and evaluated by a radiologist, otolaryngologist, and anesthesiologist before and after surgery. Major outcomes included mortality, stroke, cranial nerve injury, and recurrence. Results. Overall, nine patients (mean age: 59.5 ± 16.3 years) with a total of ten CBTs were treated. There was no gender prevalence and most of the cases (55%) were asymptomatic. There were no functional or familial cases. There was only one bilateral case treated in a staged manner. No preoperative embolization of CBTs was performed. Mortality and stroke rates were null. No severe complication was observed in the early and late setting. No malignancy was recorded. Mean follow-up was 15.6 ± 7.8 months. Conclusions. Multidisciplinary management of patients with CBTs is imperative for optimal results, especially in type III tumors, bilateral or functional cases. After careful treatment planning and intraoperative manipulations, complications could be avoided even without preoperative embolization. PMID:26783464

  1. The neurogenic niche in the carotid body and its applicability to antiparkinsonian cell therapy.

    PubMed

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

    2009-08-01

    The carotid body (CB) is a neural crest-derived organ whose major function is to sense changes in arterial O(2) tension to elicit hyperventilation during hypoxia. The CB is composed of clusters of neuron-like glomus, or type I, cells that are highly dopaminergic and contain large amounts of the glial cell line-derived neurotrophic factor (GDNF). Glomus cells are enveloped by glia-like sustentacular, or type II, cells. In chronic hypoxia the CB grows with increase in glomus cell number. This adaptive response depends on a collection of neural progenitors that can be isolated and induced to form clonal neurospheres in vitro. CB neurospheres contain numerous newly differentiated glomus cells, which maintain their functional properties and the ability to synthesize dopamine and GDNF. Intrastriatal CB transplants have been assayed in animal models of Parkinson's disease (PD) to test whether they increase the striatal dopamine levels and/or exert a neuroprotective action on the nigrostriatal pathway. Two pilot safety studies performed on PD patients subjected to CB autotransplantation have suggested that a major limitation of this technique is the small size of the organ. This could, however, be overcome by the in vitro formation of new CB tissue derived from adult CB stem cells. PMID:19263191

  2. Do the carotid body chemoreceptors mediate cardiovascular and sympathetic adjustments induced by sodium overload in rats?

    PubMed

    Pedrino, Gustavo R; Mourão, Aline A; Moreira, Marina C S; da Silva, Elaine F; Lopes, Paulo R; Fajemiroye, James O; Schoorlemmer, Guss H M; Sato, Mônica A; Reis, Ângela A S; Rebelo, Ana C S; Cravo, Sergio L

    2016-05-15

    Acute plasma hypernatremia induces several cardiovascular and sympathetic responses. It is conceivable that these responses contribute to rapid sodium excretion and restoration of normal conditions. Afferent pathways mediating these responses are not entirely understood. The present study analyses the effects of acute carotid chemoreceptor inactivation on cardiovascular and sympathetic responses induced by infusion of hypertonic saline (HS). All experiments were performed on anesthetized male Wistar rats instrumented for recording of arterial blood pressure (ABP), renal blood flow (RBF) and renal sympathetic nerve activity (RSNA). Animals were subjected to sham surgery or carotid chemoreceptor inactivation by bilateral ligation of the carotid body artery (CBA). In sham rats (n=8), intravenous infusion of HS (3 M NaCl, 1.8 ml/kg b.wt.) elicited a transient increase (9±2mmHg) in ABP, and long lasting (30 min) increases in RBF (138±5%) and renal vascular conductance (RVC) (128±5%) with concurrent decrease in RSNA (-19±4%). In rats submitted to CBA ligation (n=8), the pressor response to HS was higher (24±2mmHg; p<0.05). However, RBF and RVC responses to HS infusion were significantly reduced (113±5% and 93±4%, respectively) while RSNA was increased (13±2%). When HS (3M NaCl, 200μl) was administrated into internal carotid artery (ICA), distinct sympathetic and cardiovascular responses were observed. In sham-group, HS infusion (3M NaCl, 200μl) into ICA promoted an increase in ABP (26±8mmHg) and RSNA (29±13%). In CBA rats, ABP (-3±5.6mmHg) remained unaltered despite sympathoinhibition (-37.6±5.4%). These results demonstrate that carotid body chemoreceptors play a role in the development of hemodynamic and sympathetic responses to acute HS infusion. PMID:27060222

  3. CT AND MRI FEATURES OF CAROTID BODY PARAGANGLIOMAS IN 16 DOGS.

    PubMed

    Mai, Wilfried; Seiler, Gabriela S; Lindl-Bylicki, Britany J; Zwingenberger, Allison L

    2015-01-01

    Carotid body tumors (paragangliomas) arise from chemoreceptors located at the carotid bifurcation. In imaging studies, this neoplasm may be confused with other neck neoplasms such as thyroid carcinoma. The purpose of this retrospective, cross-sectional study was to describe computed tomographic (CT) and magnetic resonance imaging (MRI) characteristics of confirmed carotid body tumors in a multi-institutional sample of dogs. A total of 16 dogs met inclusion criteria (14 examined using CT and two with MRI). The most common reason for imaging was a palpable cervical mass or respiratory signs (i.e., dyspnea or increased respiratory noises). The most commonly affected breed was Boston terrier (n = 5). Dogs were predominantly male castrated (n = 10) and the median age was 9 years [range 3-14.5]. Most tumors appeared as a large mass centered at the carotid bifurcation, with poor margination in six dogs and discrete margins in ten dogs. Masses were iso- to hypoattenuating to adjacent muscles in CT images and hyperintense to muscles in T1- and T2-weighted MRI. For both CT and MRI, masses typically showed strong and heterogeneous contrast enhancement. There was invasion into the adjacent structures in 9/16 dogs. In six of these nine dogs, the basilar portion of the skull was affected. The external carotid artery was entrapped in seven dogs. There was invasion into the internal jugular vein in three dogs, and into the external jugular, maxillary, and linguo-facial veins in one dog. Imaging characteristics helped explain some clinical presentations such as breathing difficulties, Horner's syndrome, head tilt, or facial nerve paralysis. PMID:25846946

  4. The Role of Hypoxia-Inducible Factors in Oxygen Sensing by the Carotid Body

    PubMed Central

    Prabhakar, Nanduri R.

    2013-01-01

    Chronic intermittent hypoxia (IH) associated with sleep-disordered breathing is an important cause of hypertension, which results from carotid body-mediated activation of the sympathetic nervous system. IH triggers increased levels of reactive oxygen species (ROS) in the carotid body, which induce increased synthesis and stability of hypoxia-inducible factor 1α (HIF-1α) and calpain-dependent degradation of HIF-2α. HIF-1 activates transcription of the Nox2 gene, encoding NADPH oxidase 2, which generates superoxide. Loss of HIF-2 activity leads to decreased transcription of the Sod2 gene, encoding manganese superoxide dismutase, which converts superoxide to hydrogen peroxide. Thus, IH disrupts the balance between HIF-1-dependent pro-oxidant and HIF-2-dependent anti-oxidant activities, and this loss of redox homeostasis underlies the pathogenesis of autonomic morbidities associated with IH. PMID:23080136

  5. 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

  6. Peripheral chemoreceptors determine the respiratory sensitivity of central chemoreceptors to CO2 : role of carotid body CO2.

    PubMed

    Smith, Curtis A; Blain, Grégory M; Henderson, Kathleen S; Dempsey, Jerome A

    2015-09-15

    We asked if the type of carotid body (CB) chemoreceptor stimulus influenced the ventilatory gain of the central chemoreceptors to CO2 . The effect of CB normoxic hypocapnia, normocapnia and hypercapnia (carotid body PCO2 ≈ 22, 41 and 68 mmHg, respectively) on the ventilatory CO2 sensitivity of central chemoreceptors was studied in seven awake dogs with vascularly-isolated and extracorporeally-perfused CBs. Chemosensitivity with one CB was similar to that in intact dogs. In four CB-denervated dogs, absence of hyper-/hypoventilatory responses to CB perfusion with PCO2 of 19-75 mmHg confirmed separation of the perfused CB circulation from the brain. The group mean central CO2 response slopes were increased 303% for minute ventilation (V̇I)(P ≤ 0.01) and 251% for mean inspiratory flow rate (VT /TI ) (P ≤ 0.05) when the CB was hypercapnic vs. hypocapnic; central CO2 response slopes for tidal volume (VT ), breathing frequency (fb ) and rate of rise of the diaphragm EMG increased in 6 of 7 animals but the group mean changes did not reach statistical significance. Group mean central CO2 response slopes were also increased 237% for V̇I(P ≤ 0.01) and 249% for VT /TI (P ≤ 0.05) when the CB was normocapnic vs. hypocapnic, but no significant differences in any of the central ventilatory response indices were found between CB normocapnia and hypercapnia. These hyperadditive effects of CB hyper-/hypocapnia agree with previous findings using CB hyper-/hypoxia.We propose that hyperaddition is the dominant form of chemoreceptor interaction in quiet wakefulness when the chemosensory control system is intact, response gains physiological, and carotid body chemoreceptors are driven by a wide range of O2 and/or CO2 . PMID:26171601

  7. Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

    PubMed

    Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

    2015-01-01

    Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P < 0.01; western blot [WB]: F(3,16) = 53.52, P < 0.01) across the subgroups. GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P < 0.01; WB: F(6,29) = 15.95, P < 0.01). No detectable changes in GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB. PMID:26742253

  8. Opioid peptides in the rabbit carotid body: identification and evidence for co-utilization and interactions with dopamine.

    PubMed

    González-Guerrero, P R; Rigual, R; González, C

    1993-05-01

    The rabbit carotid body is a catecholaminergic organ that contains dopamine and norepinephrine in a proportion of nearly 5:1. Chronic (15 days) carotid sinus nerve denervation or superior cervical ganglionectomy did not modify the carotid body dopamine content (5-6 nmol/mg of protein, equivalent to 250 pmol per carotid body), but sympathectomy reduced by approximately 50% the norepinephrine content. The carotid body has also a very high content of opioid activity (250 equivalent pmol of Leu-enkephalin/mg of protein) as measured by a radioreceptor assay that detects preferentially delta-opioid activity. In the carotid body the degree of opioid posttranslational processing to low-molecular-weight peptides (mostly Leu- and Met-enkephalin) is nearly 80%. HPLC identification of opioid peptides revealed that the sequences of Met- and Leu-enkephalin were in a proportion of nearly 6:1, indicating that the main opioid precursor in the carotid body is proenkephalin A. Chronic denervations of the carotid body did not modify the levels or the degree of opioid precursor processing. Acute hypoxic exposure of the animals (8% O2 in N2; 3 h) resulted in a parallel decrease of dopamine and opioid activity, without any change in the degree of opioid processing. Norepinephrine levels were not affected by hypoxia. These findings suggest corelease of dopamine and opioids during natural hypoxic stimulation. In agreement with the analytical data, [D-Ala2, D-Leu5]enkephalin, but not [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin, reduced the in vitro release of dopamine induced by low PO2, a high external K+ concentration, and dinitrophenol. Naloxone augmented the release response elicited by low PO2 stimulation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8473894

  9. Effects of nitric oxide gas on cat carotid body chemosensory response to hypoxia.

    PubMed

    Iturriaga, R; Mosqueira, M; Villanueva, S

    2000-02-14

    It has been proposed that nitric oxide (NO) is an inhibitory modulator of carotid body (CB) chemoreception to hypoxia. However, the effects of NO gas on carotid chemoreception have not been tested yet. The role played by NO has been revealed by the use of pharmacological tools (i.e., NO donors and NO synthase inhibitors). Here, we studied the effects of NO gas (25 ppm in N(2)) on the chemosensory response to hypoxia (PO(2) approximately 30 Torr) in the cat CB perfused in vitro. During steady hypoxic chemoreceptor excitation, bolus injections or perfusion of Tyrode equilibrated with NO reduced the increased frequency of carotid chemosensory discharges (f(x)). Perfusion for 2 min of Tyrode equilibrated with NO also reduced the rate of the rise of the chemosensory response, as well as the maximal amplitude, as compared with the normal chemosensory response to hypoxia. Present results provide direct evidence that NO gas is an inhibitory modulator of CB hypoxic chemoreception. PMID:10677601

  10. 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

  11. Comparative gene expression profile of mouse carotid body and adrenal medulla under physiological hypoxia

    PubMed Central

    Ganfornina, MD; Pérez-García, MT; Gutiérrez, G; Miguel-Velado, E; López-López, JR; Marín, A; Sánchez, D; González, C

    2005-01-01

    The carotid body (CB) is an arterial chemoreceptor, bearing specialized type I cells that respond to hypoxia by closing specific K+ channels and releasing neurotransmitters to activate sensory axons. Despite having detailed information on the electrical and neurochemical changes triggered by hypoxia in CB, the knowledge of the molecular components involved in the signalling cascade of the hypoxic response is fragmentary. This study analyses the mouse CB transcriptional changes in response to low PO2 by hybridization to oligonucleotide microarrays. The transcripts were obtained from whole CBs after mice were exposed to either normoxia (21% O2), or physiological hypoxia (10% O2) for 24 h. The CB transcriptional profiles obtained under these environmental conditions were subtracted from the profile of control non-chemoreceptor adrenal medulla extracted from the same animals. Given the common developmental origin of these two organs, they share many properties but differ specifically in their response to O2. Our analysis revealed 751 probe sets regulated specifically in CB under hypoxia (388 up-regulated and 363 down-regulated). These results were corroborated by assessing the transcriptional changes of selected genes under physiological hypoxia with quantitative RT-PCR. Our microarray experiments revealed a number of CB-expressed genes (e.g. TH, ferritin and triosephosphate isomerase) that were known to change their expression under hypoxia. However, we also found novel genes that consistently changed their expression under physiological hypoxia. Among them, a group of ion channels show specific regulation in CB: the potassium channels Kir6.1 and Kcnn4 are up-regulated, while the modulatory subunit Kcnab1 is down-regulated by low PO2 levels. PMID:15890701

  12. Tetrodotoxin as a tool to elucidate sensory transduction mechanisms: the case for the arterial chemoreceptors of the carotid body.

    PubMed

    Rocher, Asuncion; Caceres, Ana Isabel; Obeso, Ana; Gonzalez, Constancio

    2011-12-01

    Carotid bodies (CBs) are secondary sensory receptors in which the sensing elements, chemoreceptor cells, are activated by decreases in arterial PO(2) (hypoxic hypoxia). Upon activation, chemoreceptor cells (also known as Type I and glomus cells) increase their rate of release of neurotransmitters that drive the sensory activity in the carotid sinus nerve (CSN) which ends in the brain stem where reflex responses are coordinated. When challenged with hypoxic hypoxia, the physiopathologically most relevant stimulus to the CBs, they are activated and initiate ventilatory and cardiocirculatory reflexes. Reflex increase in minute volume ventilation promotes CO(2) removal from alveoli and a decrease in alveolar PCO(2) ensues. Reduced alveolar PCO(2) makes possible alveolar and arterial PO(2) to increase minimizing the intensity of hypoxia. The ventilatory effect, in conjunction the cardiocirculatory components of the CB chemoreflex, tend to maintain an adequate supply of oxygen to the tissues. The CB has been the focus of attention since the discovery of its nature as a sensory organ by de Castro (1928) and the discovery of its function as the origin of ventilatory reflexes by Heymans' group (1930). A great deal of effort has been focused on the study of the mechanisms involved in O(2) detection. This review is devoted to this topic, mechanisms of oxygen sensing. Starting from a summary of the main theories evolving through the years, we will emphasize the nature and significance of the findings obtained with veratridine and tetrodotoxin (TTX) in the genesis of current models of O(2)-sensing. PMID:22363245

  13. Tetrodotoxin as a Tool to Elucidate Sensory Transduction Mechanisms: The Case for the Arterial Chemoreceptors of the Carotid Body

    PubMed Central

    Rocher, Asuncion; Caceres, Ana Isabel; Obeso, Ana; Gonzalez, Constancio

    2011-01-01

    Carotid bodies (CBs) are secondary sensory receptors in which the sensing elements, chemoreceptor cells, are activated by decreases in arterial PO2 (hypoxic hypoxia). Upon activation, chemoreceptor cells (also known as Type I and glomus cells) increase their rate of release of neurotransmitters that drive the sensory activity in the carotid sinus nerve (CSN) which ends in the brain stem where reflex responses are coordinated. When challenged with hypoxic hypoxia, the physiopathologically most relevant stimulus to the CBs, they are activated and initiate ventilatory and cardiocirculatory reflexes. Reflex increase in minute volume ventilation promotes CO2 removal from alveoli and a decrease in alveolar PCO2 ensues. Reduced alveolar PCO2 makes possible alveolar and arterial PO2 to increase minimizing the intensity of hypoxia. The ventilatory effect, in conjunction the cardiocirculatory components of the CB chemoreflex, tend to maintain an adequate supply of oxygen to the tissues. The CB has been the focus of attention since the discovery of its nature as a sensory organ by de Castro (1928) and the discovery of its function as the origin of ventilatory reflexes by Heymans group (1930). A great deal of effort has been focused on the study of the mechanisms involved in O2 detection. This review is devoted to this topic, mechanisms of oxygen sensing. Starting from a summary of the main theories evolving through the years, we will emphasize the nature and significance of the findings obtained with veratridine and tetrodotoxin (TTX) in the genesis of current models of O2-sensing. PMID:22363245

  14. [Intraventricular hemorrhage after carotid endarterectomy. Role of moyamoya-type collateral circulation].

    PubMed

    Masson, C; Martin, N; Masson, M; Cambier, J

    1986-01-01

    Stenotic lesions of the cervical arteries due to atherosclerosis or irradiation may provoke the development of a Moya-Moya type collateral network. Rupture of a vessel participating in this collateral circulation may be the cause of a hemorrhagic accident. The hemorrhage may be subarachnoid, intracerebral or more usually intraventricular. Intraventricular hemorrhage occurred in a patient who had developed a Moya-Moya type collateral circulation secondary to atherosclerotic stenosis of a carotid artery. The hemorrhagic incident occurred during carotid endarterectomy, suggesting a predisposing role for hemodynamic modifications resulting from the operation. PMID:3809859

  15. Effects of lifestyle modification on metabolic parameters and carotid intima-media thickness in patients with type 2 diabetes mellitus.

    PubMed

    Kim, So Hun; Lee, Suk Jeong; Kang, Eun Seok; Kang, Shinae; Hur, Kyu Yeon; Lee, Hyun Joo; Ahn, Chul Woo; Cha, Bong Soo; Yoo, Ji Soo; Lee, Hyun Chul

    2006-08-01

    The aim of this study was to examine the effects of a 6-month intensive lifestyle modification intervention on metabolic parameters and carotid intima-media thickness (IMT) in patients with type 2 diabetes mellitus. Fifty-eight subjects with type 2 diabetes mellitus were randomly assigned to the intervention group or the control group. The subjects in the intervention group participated in a 16-week intensive lifestyle modification program and subsequent monthly meetings during the 6-month study period. Control subjects received basic dietary education and usual care. Anthropometric data, metabolic parameters, and carotid IMT were examined before the intervention and after 6 months. Lifestyle modification intervention group patients showed a significant reduction in HbA1c (-1.0% +/- 1.3% vs +0.1% +/- 1.2%, P = .002), fasting blood glucose (-1.6 +/- 1.5 vs +0.3 +/- 2.5 mmol/L, P = .001), and 2-hour postprandial plasma glucose (-2.1 +/- 2.5 vs +0.8 +/- 4.4 mmol/L, P = .003) compared with control patients after 6 months. Body weight (-2.0 +/- 2.6 vs +0.2 +/- 1.7 kg, P = .001), body mass index (-0.8 +/- 1.0 vs 0.0 +/- 0.8 kg/m2, P = .003), and systolic blood pressure (-8.2 +/- 15.9 vs +0.4 +/- 14.1 mm Hg, P = .041) were significantly decreased in the intervention group. A significantly reduced carotid mean IMT progression was seen in the intervention group after 6 months (-0.040 +/- 0.136 vs +0.083 +/- 0.167 mm, P = .007). Changes in HbA1c (r = 0.34, P = .028), fasting plasma glucose (r = 0.31, P = .045), and 2-hour postprandial plasma glucose (r = 0.37, P = .015) correlated with the mean carotid IMT change after adjustment for age and sex. In conclusion, a 6-month intensive lifestyle modification intervention in patients with type 2 diabetes mellitus resulted in improved glycemic control and decreased progression of carotid IMT. PMID:16839841

  16. The human carotid body transcriptome with focus on oxygen sensing and inflammation – a comparative analysis

    PubMed Central

    Mkrtchian, Souren; Kåhlin, Jessica; Ebberyd, Anette; Gonzalez, Constancio; Sanchez, Diego; Balbir, Alexander; Kostuk, Eric W; Shirahata, Machiko; Fagerlund, Malin Jonsson; Eriksson, Lars I

    2012-01-01

    The carotid body (CB) is the key oxygen sensing organ. While the expression of CB specific genes is relatively well studied in animals, corresponding data for the human CB are missing. In this study we used five surgically removed human CBs to characterize the CB transcriptome with microarray and PCR analyses, and compared the results with mice data. In silico approaches demonstrated a unique gene expression profile of the human and mouse CB transcriptomes and an unexpected upregulation of both human and mouse CB genes involved in the inflammatory response compared to brain and adrenal gland data. Human CBs express most of the genes previously proposed to be involved in oxygen sensing and signalling based on animal studies, including NOX2, AMPK, CSE and oxygen sensitive K+ channels. In the TASK subfamily of K+ channels, TASK-1 is expressed in human CBs, while TASK-3 and TASK-5 are absent, although we demonstrated both TASK-1 and TASK-3 in one of the mouse reference strains. Maxi-K was expressed exclusively as the spliced variant ZERO in the human CB. In summary, the human CB transcriptome shares important features with the mouse CB, but also differs significantly in the expression of a number of CB chemosensory genes. This study provides key information for future functional investigations on the human carotid body. PMID:22615433

  17. Sclerosing paraganglioma of the carotid body: a potential pitfall of malignancy.

    PubMed

    Santi, Raffaella; Franchi, Alessandro; Saladino, Valeria; Trovati, Massimo; Cenacchi, Giovanna; Squadrelli-Saraceno, Massimo; Nesi, Gabriella

    2015-06-01

    Paragangliomas (PGs) of the head and neck region are typically benign, slow-growing neuroendocrine tumours. At times, they may exhibit unusual histological features, such as prominent stromal sclerosis (sclerosing PG), which may raise concerns of malignancy. We describe a case of sclerosing PG of the carotid body, emphasizing the value of immunohistochemical stains for differential diagnosis. A 43-year-old woman presented with a painless lump on the neck. A magnetic resonance imaging scan demonstrated a hypervascular lesion of the carotid body, which was surgically excised. Grossly, the lesion measured 1.8 cm at maximum diameter. On microscopic examination, irregular nests and tiny bundles of neoplastic cells were found between thick bands of fibrous tissue. Focal nuclear cytomegaly and marked pleomorphism were noted. Neoplastic cells proved to be immunoreactive for chromogranin, synaptophysin and neuron specific enolase, but negative for cytokeratins, smooth muscle actin and CD34. Ultrastructurally, numerous mitochondria, rough endoplasmic reticulum structures and endocrine granules were seen in the cytoplasm of the tumour cells. On consideration of the above-mentioned clinico-pathological and ultrastructural findings a diagnosis of sclerosing PG was established. Sclerosing PG is a rare entity which may mimic a malignant neoplasm. The recognition of this unusual morphological variant of PG, together with appropriate immunostains, leads to the correct diagnosis. PMID:25194351

  18. Peptide receptor radionuclide therapy with (177)Lu DOTATATE in a case of recurrent carotid body paraganglioma with spinal metastases.

    PubMed

    Gupta, Santosh Kumar; Singla, Suhas; Karunanithi, Sellam; Damle, Nishikant; Bal, Chandrasekhar

    2014-05-01

    Paragangliomas are rare benign neuroendocrine tumors, and 80% of all paragangliomas are either carotid body tumors or glomus jugulare tumors. We present a case of recurrent unresectable carotid body paraganglioma with nodal and T7 vertebral metastases in a 30-year-old man 6 years postsurgery detected with Ga DOTANOC PET/CT and was administered with peptide receptor radionuclide therapy using Lu DOTATATE. After 5 cycles of Lu DOTATATE (total cumulative activity of 750 mCi [27 GBq]), significant response at the primary site on Ga DOTANOC PET/CT and complete disappearance of nodal and T7 vertebral metastases were noted. PMID:24217545

  19. The relationship between distribution of body fat mass and carotid artery intima-media thickness in Korean older adults

    PubMed Central

    Park, Jin-Kee; Park, Hyuntae; Kim, Kwi-Baek

    2015-01-01

    [Purpose] The aim of this study was to examine the relationships between the amount and distribution of body fat and the carotid intima-media thickness to explore whether coronary artery disease risk may be mediated through effects on the amount of fat mass in older adults. [Subjects and Methods] A total of 200 elderly females was participated. The percentage of body fat mass was measured by the bioelectrical impedance analysis method, and the carotid intima-media thickness was measured by B-mode ultrasound. Analysis of covariance was performed to assess independent associations between the four categories of percentage of body fat mass and the carotid intima-media thickness after multivariate adjustment. Logistic regression analyses were utilized to calculate odds ratios and 95% confidence intervals for examining independent associations between percentage of body fat mass and the estimated risk of coronary artery disease. [Results] Analysis of covariance showed that the carotid intima-media thickness was significantly thick in both obesity and overweight groups. When multivariate-adjusted OR for the estimated risk of coronary artery disease, the odds ratios for the obesity and overweight groups were 3.0 (95% confidence interval, 1.1 to 8.7) and 2.5 (95% confidence interval, 1.0 to 6.1), respectively. [Conclusion] This study demonstrates that elderly females with a high body fat mass are more likely to have the estimated risk of CAD than who fit body fat mass in elderly female. PMID:26633917

  20. The relationship between distribution of body fat mass and carotid artery intima-media thickness in Korean older adults.

    PubMed

    Park, Jin-Kee; Park, Hyuntae; Kim, Kwi-Baek

    2015-10-01

    [Purpose] The aim of this study was to examine the relationships between the amount and distribution of body fat and the carotid intima-media thickness to explore whether coronary artery disease risk may be mediated through effects on the amount of fat mass in older adults. [Subjects and Methods] A total of 200 elderly females was participated. The percentage of body fat mass was measured by the bioelectrical impedance analysis method, and the carotid intima-media thickness was measured by B-mode ultrasound. Analysis of covariance was performed to assess independent associations between the four categories of percentage of body fat mass and the carotid intima-media thickness after multivariate adjustment. Logistic regression analyses were utilized to calculate odds ratios and 95% confidence intervals for examining independent associations between percentage of body fat mass and the estimated risk of coronary artery disease. [Results] Analysis of covariance showed that the carotid intima-media thickness was significantly thick in both obesity and overweight groups. When multivariate-adjusted OR for the estimated risk of coronary artery disease, the odds ratios for the obesity and overweight groups were 3.0 (95% confidence interval, 1.1 to 8.7) and 2.5 (95% confidence interval, 1.0 to 6.1), respectively. [Conclusion] This study demonstrates that elderly females with a high body fat mass are more likely to have the estimated risk of CAD than who fit body fat mass in elderly female. PMID:26633917

  1. H2S production by reactive oxygen species in the carotid body triggers hypertension in a rodent model of sleep apnea.

    PubMed

    Yuan, Guoxiang; Peng, Ying-Jie; Khan, Shakil A; Nanduri, Jayasri; Singh, Amritha; Vasavda, Chirag; Semenza, Gregg L; Kumar, Ganesh K; Snyder, Solomon H; Prabhakar, Nanduri R

    2016-01-01

    Sleep apnea is a prevalent respiratory disease in which episodic cessation of breathing causes intermittent hypoxia. Patients with sleep apnea and rodents exposed to intermittent hypoxia exhibit hypertension. The carotid body senses changes in blood O2 concentrations, and an enhanced carotid body chemosensory reflex contributes to hypertension in sleep apnea patients. A rodent model of intermittent hypoxia that mimics blood O2 saturation profiles of patients with sleep apnea has shown that increased generation of reactive oxygen species (ROS) in the carotid body enhances the chemosensory reflex and triggers hypertension. CO generated by heme oxygenase-2 (HO-2) induces a signaling pathway that inhibits hydrogen sulfide (H2S) production by cystathionine γ-lyase (CSE), leading to suppression of carotid body activity. We found that ROS inhibited CO generation by HO-2 in the carotid body and liver through a mechanism that required Cys(265) in the heme regulatory motif of heterologously expressed HO-2. We showed that ROS induced by intermittent hypoxia inhibited CO production and increased H2S concentrations in the carotid body, which stimulated its neural activity. In rodents, blockade of H2S synthesis by CSE, by either pharmacologic or genetic approaches, inhibited carotid body activation and hypertension induced by intermittent hypoxia. Thus, our results indicate that oxidant-induced inactivation of HO-2, which leads to increased CSE-dependent H2S production in the carotid body, is a critical trigger of hypertension in rodents exposed to intermittent hypoxia. PMID:27531649

  2. Effects of cyanide and uncouplers on chemoreceptor activity and ATP content of the cat carotid body.

    PubMed

    Obeso, A; Almaraz, L; Gonzalez, C

    1989-03-01

    In cat carotid bodies (c.b.'s) incubated in vitro with [3H]tyrosine to label the stores of catecholamines, it was found that CN promotes dose- and Ca2+-dependent release of [3H]dopamine (DA) from c.b. tissues in parallel to the increased electrical activity recorded from the carotid sinus nerve (c.s.n.). Two different uncouplers, dinitrophenol (DNP) and carbonyl-cyanide-m-chlorophenyl-hydrazone (CCCP), both activate also in a dose-dependent fashion, release of DA and electrical activity in the c.s.n. However, while cyanide (CN) (10(-4) M) applied during 5 min reduced the adenosine triphosphate (ATP) content of the c.b. by 45%, DNP (2.5 x 10(-4) M) and CCCP (10(-6) M) applied for the same period of time did not modify the ATP levels of the organ. At the above concentrations, the 3 agents increased about 8-fold the electrical activity recorded from the c.s.n. Thus, contrary to the postulates of the metabolic hypotheses, our findings indicate that the decrease in the ATP content in the c.b. is not a prerequisite for the activation of the chemoreceptors. We propose alternative mechanisms to explain the chemostimulant action of the metabolic poisons. PMID:2720379

  3. Inhibitory effects of NO on carotid body: contribution of neural and endothelial nitric oxide synthase isoforms.

    PubMed

    Valdés, Viviana; Mosqueira, Matías; Rey, Sergio; Del Rio, Rodrigo; Iturriaga, Rodrigo

    2003-01-01

    We tested the hypothesis that nitric oxide (NO) produced within the carotid body is a tonic inhibitor of chemoreception and determined the contribution of neuronal and endothelial nitric oxide synthase (eNOS) isoforms to the inhibitory NO effect. Accordingly, we studied the effect of NO generated from S-nitroso-N-acetylpenicillamide (SNAP) and compared the effects of the nonselective inhibitor N(omega)-nitro-l-arginine methyl ester (l-NAME) and the selective nNOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole (TRIM) on chemosensory dose-response curves induced by nicotine and NaCN and responses to hypoxia (Po(2) approximately 30 Torr). CBs excised from pentobarbitone-anesthetized cats were perfused in vitro with Tyrode at 38 degrees C and pH 7.40, and chemosensory discharges were recorded from the carotid sinus nerve. SNAP (100 microM) reduced the responses to nicotine and NaCN. l-NAME (1 mM) enhanced the responses to nicotine and NaCN by increasing their duration, but TRIM (100 microM) only enhanced the responses to high doses of NaCN. The amplitude of the response to hypoxia was enhanced by l-NAME but not by TRIM. Our results suggest that both isoforms contribute to the NO action, but eNOS being the main source for NO in the cat CB and exerting a tonic effect upon chemoreceptor activity. PMID:12388352

  4. Carotid body chemosensory excitation induced by nitric oxide: involvement of oxidative metabolism.

    PubMed

    Mosqueira, Matias; Iturriaga, Rodrigo

    2002-08-01

    Nitric oxide (NO) produces a dual effect on carotid body (CB) oxygen chemoreception. At low concentration, NO inhibits chemosensory response to hypoxia, while in normoxia, medium and high [NO] increases the frequency of carotid chemosensory discharges (f(x)). Since NO and peroxynitrite inhibit mitochondrial respiration, it is plausible that the NO-induced excitation may depend on the mitochondrial oxidative metabolism. To test this hypothesis, we studied the effects of oligomycin, FCCP and antimycin A that produce selective blockade of hypoxic and NaCN-induced chemosensory responses, leaving nicotinic response less affected. CBs excised from pentobarbitone-anaesthetised cats were perfused in vitro with Tyrode (P(O(2)) approximately 125 Torr, pH 7.40 at 38 degrees C). Hypoxia (P(O(2)) approximately equal 30 Torr), NaCN and nicotine (1-100 microg) and S-nitroso-N-acetylpenicillamide (SNAP, 300-600 microg) increased f(x). Oligomycin (12.5-25 microg), antimycin A (10 microg) and FCCP (5 microM) transiently increased f(x). Subsequently, chemosensory responses to hypoxia, NaCN and SNAP were reduced or abolished, while the response to nicotine was less affected. The electron donor system tetramethyl-p-phenylene diamide and ascorbate that bypasses the electron chain blockade produced by antimycin A, restores the excitatory responses to NaCN and SNAP. Present results suggest that the chemoexcitatory effect of NO depends on the integrity of mitochondrial metabolism. PMID:12126919

  5. Hypoxic pulmonary vasoconstriction, carotid body function and erythropoietin production in adult rats perinatally exposed to hyperoxia

    PubMed Central

    Prieto-Lloret, Jesus; Ramirez, Maria; Olea, Elena; Moral-Sanz, Javier; Cogolludo, Angel; Castañeda, Javier; Yubero, Sara; Agapito, Teresa; Gomez-Niño, Angela; Rocher, Asuncion; Rigual, Ricardo; Obeso, Ana; Perez-Vizcaino, Francisco; González, Constancio

    2015-01-01

    Adult mammalians possess three cell systems that are activated by acute bodily hypoxia: pulmonary artery smooth muscle cells (PASMC), carotid body chemoreceptor cells (CBCC) and erythropoietin (EPO)-producing cells. In rats, chronic perinatal hyperoxia causes permanent carotid body (CB) atrophy and functional alterations of surviving CBCC. There are no studies on PASMC or EPO-producing cells. Our aim is to define possible long-lasting functional changes in PASMC or EPO-producing cells (measured as EPO plasma levels) and, further, to analyse CBCC functional alterations. We used 3- to 4-month-old rats born and reared in a normal atmosphere or exposed to perinatal hyperoxia (55–60% O2 for the last 5–6 days of pregnancy and 4 weeks after birth). Perinatal hyperoxia causes an almost complete loss of hypoxic pulmonary vasoconstriction (HPV), which was correlated with lung oxidative status in early postnatal life and prevented by antioxidant supplementation in the diet. O2-sensitivity of K+ currents in the PASMC of hyperoxic animals is normal, indicating that their inhibition is not sufficient to trigger HPV. Perinatal hyperoxia also abrogated responses elicited by hypoxia on catecholamine and cAMP metabolism in the CB. An increase in EPO plasma levels elicited by hypoxia was identical in hyperoxic and control animals, implying a normal functioning of EPO-producing cells. The loss of HPV observed in adult rats and caused by perinatal hyperoxia, comparable to oxygen therapy in premature infants, might represent a previously unrecognized complication of such a medical intervention capable of aggravating medical conditions such as regional pneumonias, atelectases or general anaesthesia in adult life. Key points Adult animals that have been perinatally exposed to oxygen-rich atmospheres (hyperoxia), recalling those used for oxygen therapy in infants, exhibit a loss of hypoxic pulmonary vasoconstriction, whereas vasoconstriction elicited by depolarizing agents is

  6. Acrolein inhalation alters arterial blood gases and triggers carotid body-mediated cardiovascular responses in hypertensive rats

    PubMed Central

    Perez, Christina M.; Hazari, Mehdi S.; Ledbetter, Allen D.; Haykal-Coates, Najwa; Carll, Alex P.; Cascio, Wayne E.; Winsett, Darrell W.; Costa, Daniel L.; Farraj, Aimen K.

    2016-01-01

    Context Air pollution exposure affects autonomic function, heart rate, blood pressure and left ventricular function. While the mechanism for these effects is uncertain, several studies have reported that air pollution exposure modifies activity of the carotid body, the major organ that senses changes in arterial oxygen and carbon dioxide levels, and elicits downstream changes in autonomic control and cardiac function. Objective We hypothesized that exposure to acrolein, an unsaturated aldehyde and mucosal irritant found in cigarette smoke and diesel exhaust, would activate the carotid body chemoreceptor response and lead to secondary cardiovascular responses in rats. Materials and methods Spontaneously hypertensive (SH) rats were exposed once for 3 h to 3 ppm acrolein gas or filtered air in whole body plethysmograph chambers. To determine if the carotid body mediated acrolein-induced cardiovascular responses, rats were pretreated with an inhibitor of cystathionine γ-lyase (CSE), an enzyme essential for carotid body signal transduction. Results Acrolein exposure induced several cardiovascular effects. Systolic, diastolic and mean arterial blood pressure increased during exposure, while cardiac contractility decreased 1 day after exposure. The cardiovascular effects were associated with decreases in pO2, breathing frequency and expiratory time, and increases in sympathetic tone during exposure followed by parasympathetic dominance after exposure. The CSE inhibitor prevented the cardiovascular effects of acrolein exposure. Discussion and conclusion Pretreatment with the CSE inhibitor prevented the cardiovascular effects of acrolein, suggesting that the cardiovascular responses with acrolein may be mediated by carotid body-triggered changes in autonomic tone. (This abstract does not reflect EPA policy.) PMID:25600140

  7. Volatile Anaesthetic Depression of the Carotid Body Chemoreflex-Mediated Ventilatory Response to Hypoxia: Directions for Future Research

    PubMed Central

    Pandit, J. J.

    2014-01-01

    In assessing whether volatile anaesthetics directly depress the carotid body response to hypoxia it is necessary to combine in meta-analysis studies of when it is “functionally isolated” (e.g., recordings are made from its afferent nerve). Key articles were retrieved (full papers in English) and subjected to quantitative analysis to yield an aggregate estimate of effect. Results from articles that did not use such methodology were assessed separately from this quantitative approach, to see what could be learned also from a nonquantitative overview. Just 7 articles met the inclusion criteria for hypoxia and just 6 articles for hypercapnia. Within these articles, the anaesthetic (mean dose 0.75, standard deviation (SD) 0.40 minimum alveolar concentration, MAC) statistically significantly depressed carotid body hypoxic response by 24% (P = 0.041), but a similar dose (mean 0.81 (0.42) MAC) did not affect the hypercapnic response. The articles not included in the quantitative analysis (31 articles), assessed qualitatively, also indicated that anaesthetics depress carotid body function. This conclusion helps direct future research on the anaesthetic effects on putative cellular/molecular processes that underlie the transduction of hypoxia in the carotid body. PMID:24808974

  8. Relevance of the Carotid Body Chemoreflex in the Progression of Heart Failure

    PubMed Central

    Andrade, David C.; Lucero, Claudia; Toledo, Camilo; Madrid, Carlos; Marcus, Noah J.; Schultz, Harold D.; Del Rio, Rodrigo

    2015-01-01

    Chronic heart failure (CHF) is a global health problem affecting millions of people. Autonomic dysfunction and disordered breathing patterns are commonly observed in patients with CHF, and both are strongly related to poor prognosis and high mortality risk. Tonic activation of carotid body (CB) chemoreceptors contributes to sympathoexcitation and disordered breathing patterns in experimental models of CHF. Recent studies show that ablation of the CB chemoreceptors improves autonomic function and breathing control in CHF and improves survival. These exciting findings indicate that alterations in CB function are critical to the progression of CHF. Therefore, better understanding of the physiology of the CB chemoreflex in CHF could lead to improvements in current treatments and clinical management of patients with CHF characterized by high chemosensitivity. Accordingly, the main focus of this brief review is to summarize current knowledge of CB chemoreflex function in different experimental models of CHF and to comment on their potential translation to treatment of human CHF. PMID:26779536

  9. Brainstem PCO2 modulates phrenic responses to specific carotid body hypoxia in an in situ dual perfused rat preparation

    PubMed Central

    Day, Trevor A; Wilson, Richard J A

    2007-01-01

    Inputs from central (brainstem) and peripheral (carotid body) respiratory chemoreceptors are coordinated to protect blood gases against potentially deleterious fluctuations. However, the mathematics of the steady-state interaction between chemoreceptors has been difficult to ascertain. Further, how this interaction affects time-dependent phenomena (in which chemoresponses depend upon previous experience) is largely unknown. To determine how central PCO2 modulates the response to peripheral chemostimulation in the rat, we utilized an in situ arterially perfused, vagotomized, decerebrate preparation, in which central and peripheral chemoreceptors were perfused separately (i.e. dual perfused preparation (DPP)). We carried out two sets of experiments: in Experiment 1, we alternated steady-state brainstem PCO2 between 25 and 50 Torr in each preparation, and applied specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) under both conditions; in Experiment 2, we applied four 5 min bouts (separated by 5 min) of specific carotid body hypoxia (60 Torr PO2 and 40 Torr PCO2) while holding the brainstem at either 30 Torr or 50 Torr PCO2. We demonstrate that the level of brainstem PCO2 modulates (a) the magnitude of the phrenic responses to a single step of specific carotid body hypoxia and (b) the magnitude of time-dependent phenomena. We report that the interaction between chemoreceptors is negative (i.e. hypo-additive), whereby a lower brainstem PCO2 augments phrenic responses resulting from specific carotid body hypoxia. A negative interaction may underlie the pathophysiology of central sleep apnoea in populations that are chronically hypocapnic. PMID:17082232

  10. EPAC signalling pathways are involved in low PO2 chemoreception in carotid body chemoreceptor cells

    PubMed Central

    Rocher, Asuncion; Caceres, Ana I; Almaraz, Laura; Gonzalez, Constancio

    2009-01-01

    Chemoreceptor cells of the carotid bodies (CB) are activated by hypoxia and acidosis, responding with an increase in their rate of neurotransmitter release, which in turn increases the electrical activity in the carotid sinus nerve and evokes a homeostatic hyperventilation. Studies in isolated chemoreceptor cells have shown that moderate hypoxias (≈ 46 mmHg) produces smaller depolarisations and comparable Ca2+ transients but a much higher catecholamine (CA) release response in intact CBs than intense acidic/hypercapnic stimuli (20% CO2, pH 6.6). Similarly, intense hypoxia (≈ 20 mmHg) produces smaller depolarizations and Ca2+ transients in isolated chemoreceptor cells but a higher CA release response in intact CBs than a pure depolarizing stimulus (30–35 mm external K+). Studying the mechanisms responsible for these differences we have found the following. (1) Acidic hypercapnia inhibited ICa (∼60%; whole cell) and CA release (∼45%; intact CB) elicited by ionomycin and high K+. (2) Adenylate cyclase inhibition (SQ-22536; 80 μm) inhibited the hypoxic release response (>50%) and did not affect acidic/hypercapnic release, evidencing that the high gain of hypoxia to elicit neurotransmitter release is cAMP dependent. (3) The last effect was independent of PKA activation, as three kinase inhibitors (H-89, KT 5720 and Rp-cAMP; ≥ 10 × IC50) did not alter the hypoxic release response. (4) The Epac (exchange protein activated by cAMP) activator (8-pCPT-2′-O-Me-cAMP, 100 μm) reversed the effects of the cyclase inhibitor. (5) The Epac inhibitor brefeldin A (100 μm) inhibited (54%) hypoxic induced release. Our findings show for the first time that an Epac-mediated pathway mediates O2 sensing/transduction in chemoreceptor cells. PMID:19581380

  11. Vitamin D, carotid intima–media thickness and bone structure in patients with type 2 diabetes

    PubMed Central

    Winckler, Karoline; Tarnow, Lise; Lundby-Christensen, Louise; Almdal, Thomas P; Wiinberg, Niels; Eiken, Pia; Boesgaard, Trine W

    2015-01-01

    Despite aggressive treatment of cardiovascular disease (CVD) risk factors individuals with type 2 diabetes (T2D) still have increased risk of cardiovascular morbidity and mortality. The primary aim of this study was to examine the cross-sectional association between total (25-hydroxy vitamin D (25(OH)D)) and risk of CVD in patients with T2D. Secondary objective was to examine the association between 25(OH)D and bone health. A Danish cohort of patients with T2D participating in a randomised clinical trial were analysed. In total 415 patients (68% men, age 60±9 years (mean±s.d.), duration of diabetes 12±6 years), including 294 patients (71%) treated with insulin. Carotid intima–media thickness (IMT) and arterial stiffness (carotid artery distensibility coefficient (DC) and Young's elastic modulus (YEM)) were measured by ultrasound scan as indicators of CVD. Bone health was assessed by bone mineral density and trabecular bone score measured by dual energy X-ray absorptiometry. In this cohort, 214 patients (52%) were vitamin D deficient (25(OH)D <50 nmol/l). Carotid IMT was 0.793±0.137 mm, DC was 0.0030±0.001 mmHg, YEM was 2354±1038 mmHg and 13 (3%) of the patients were diagnosed with osteoporosis. A 25(OH)D level was not associated with carotid IMT or arterial stiffness (P>0.3) or bone health (P>0.6) after adjustment for CVD risk factors. In conclusion, 25(OH)D status was not associated with carotid IMT, arterial stiffness or bone health in this cohort of patients with T2D. To explore these associations and the association with other biomarkers further, multicentre studies with large numbers of patients are required. PMID:25956908

  12. Carotid body denervation improves autonomic and cardiac function and attenuates disordered breathing in congestive heart failure

    PubMed Central

    Marcus, Noah J; Rio, Rodrigo; Schultz, Evan P; Xia, Xiao-Hong; Schultz, Harold D

    2014-01-01

    In congestive heart failure (CHF), carotid body (CB) chemoreceptor activity is enhanced and is associated with oscillatory (Cheyne–Stokes) breathing patterns, increased sympathetic nerve activity (SNA) and increased arrhythmia incidence. We hypothesized that denervation of the CB (CBD) chemoreceptors would reduce SNA, reduce apnoea and arrhythmia incidence and improve ventricular function in pacing-induced CHF rabbits. Resting breathing, renal SNA (RSNA) and arrhythmia incidence were measured in three groups of animals: (1) sham CHF/sham–CBD (sham–sham); (2) CHF/sham–CBD (CHF–sham); and (3) CHF/CBD (CHF–CBD). Chemoreflex sensitivity was measured as the RSNA and minute ventilatory () responses to hypoxia and hypercapnia. Respiratory pattern was measured by plethysmography and quantified by an apnoea–hypopnoea index, respiratory rate variability index and the coefficient of variation of tidal volume. Sympatho-respiratory coupling (SRC) was assessed using power spectral analysis and the magnitude of the peak coherence function between tidal volume and RSNA frequency spectra. Arrhythmia incidence and low frequency/high frequency ratio of heart rate variability were assessed using ECG and blood pressure waveforms, respectively. RSNA and responses to hypoxia were augmented in CHF–sham and abolished in CHF–CBD animals. Resting RSNA was greater in CHF–sham compared to sham–sham animals (43 ± 5% max vs. 23 ± 2% max, P < 0.05), and this increase was not found in CHF–CBD animals (25 ± 1% max, P < 0.05 vs. CHF–sham). Low frequency/high frequency heart rate variability ratio was similarly increased in CHF and reduced by CBD (P < 0.05). Respiratory rate variability index, coefficient of variation of tidal volume and apnoea–hypopnoea index were increased in CHF–sham animals and reduced in CHF–CBD animals (P < 0.05). SRC (peak coherence) was increased in CHF–sham animals (sham–sham 0.49 ± 0.05; CHF–sham 0.79

  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. PMID:26764048

  14. Carotid artery intima-media thickness and distensibility in children and adolescents: reference values and role of body dimensions.

    PubMed

    Doyon, Anke; Kracht, Daniela; Bayazit, Aysun K; Deveci, Murat; Duzova, Ali; Krmar, Rafael T; Litwin, Mieczyslaw; Niemirska, Anna; Oguz, Berna; Schmidt, Bernhard M W; Sözeri, Betul; Querfeld, Uwe; Melk, Anette; Schaefer, Franz; Wühl, Elke

    2013-09-01

    Carotid intima-media thickness (cIMT) and carotid artery distensibility are reliable screening methods for vascular alterations and the assessment of cardiovascular risk in adult and pediatric cohorts. We sought to establish an international reference data set for the childhood and adolescence period and explore the impact of developmental changes in body dimensions and blood pressure (BP) on carotid wall thickness and elasticity. cIMT, the distensibility coefficient, the incremental modulus of elasticity, and the stiffness index β were assessed in 1155 children aged 6 to 18 years and sex-specific reference charts normalized to age or height were constructed from 1051 nonobese and nonhypertensive children. The role of body dimensions, BP, and family history, as well as the association between cIMT and distensibility, was investigated. cIMT increased and distensibility decreased with age, height, body mass index, and BP. A significant sex difference was apparent from the age of 15 years. Age- and height-normalized cIMT and distensibility values differed in children who are short or tall for their age. By stepwise multivariate analysis, standardized systolic BP and body mass index were independently positively associated with cIMT SD scores (SDS). Systolic BP SDS independently predicted all distensibility measures. Distensibility coefficient SDS was negatively and β SDS positively associated with cIMT SDS, whereas incremental modulus of elasticity was independent of cIMT. Morphological and functional aspects of the common carotid artery are particularly influenced by age, body dimensions, and BP. The reference charts established in this study allow to accurately compare vascular phenotypes of children with chronic conditions with those of healthy children. PMID:23817494

  15. Extracellular potassium and chemosensitivity in the rat carotid body, in vitro.

    PubMed Central

    Pepper, D R; Landauer, R C; Kumar, P

    1996-01-01

    1. The effects of raising extracellular potassium concentration ([K+]o) from 3.0 to 5.3, 9.5 or 16.8 mM on chemoreceptor responses to hypoxia, hypercapnia and asphyxia were examined in a superfused in vitro rat carotid body preparation. 2. Single-exponential functions with offset were fitted to the chemoreceptor discharge responses to ramp decreases in Po2. Increasing [K+]o was without effect upon the rate constants of the fitted exponential functions (P > 0.20). Increasing [K+]o, significantly increased the horizontal asymptote (chemoreceptor discharge in hyperoxia) in a non-linear fashion when all levels of [K+]o were included in the analysis (P < 0.001) but not when a comparison was made only between 3.0 and 5.3 mM Ko+ (P > 0.40). The rightward position of the response curves, as quantified by the Po2 at 50% maximum discharge, was linearly related to [K+]o but only when all levels of [K+]o were included in the analysis (P < 0.03). Chemoreceptor sensitivity to [K+]o increased non-linearly as [K+]o was increased but this effect was not dependent upon the Po2 (P > 0.90). 4. Increasing PCO2 in hyperoxia increased chemoreceptor discharge linearly at all levels of [K+]o. Whilst discharge at any level of PCO2 was elevated by increased levels of [K+]o, raising [K+]o did not increase CO2 sensitivity (P > 0.20). Similarly, increasing PCO2 did not increase chemosensitivity to [K+]o. The lack of effect of [K+]o upon CO2 chemosensitivity was also observed as Po2 was decreased to hypoxic levels (P > 0.10). 5. Our data demonstrate that an elevation of [K+]o can increase chemoreceptor discharge in the in vitro carotid body in a PO2- and PCO2-independent manner, suggesting that the PO2-dependent effects of [K+]o, previously reported in vivo may be due to other indirect effects of [K+]o or hypoxia. PMID:8799903

  16. Almitrine has no effect on gas exchange after bilateral carotid body resection in severe chronic airflow obstruction.

    PubMed

    De Backer, W; Vermeire, P; Bogaert, E; Janssens, E; Van Maele, R

    1985-01-01

    Using a double-blind cross-over design, a single dose of 100 mg almitrine bismesylate and placebo were administered orally to eight patients with chronic airflow obstruction having undergone bilateral carotid body resection (BCBR) up to two years earlier to alleviate their extreme dyspnoea. In an open study, two other patients have been given almitrine before and three weeks after BCBR. In all patients, arterial blood gases, ventilation and breathing patterns, neuromuscular drive and hypoxic responsiveness have been studied before and three hours after drug administration. Almitrine failed to improve gas exchange in the patients with BCBR, nor did it affect ventilation, ventilatory or hypoxic drive. In the patients studied before and after BCBR, almitrine only improved gas exchange significantly before BCBR. It is concluded that in man almitrine acts solely as a peripheral chemoreceptor agonist and that the well-documented improvement in V/Q relationship is mediated through carotid body stimulation. PMID:3904873

  17. Neuroprotective and reparative effects of carotid body grafts in a chronic MPTP model of Parkinson's disease.

    PubMed

    Muñoz-Manchado, Ana B; Villadiego, Javier; Suárez-Luna, Nela; Bermejo-Navas, Alfonso; Garrido-Gil, Pablo; Labandeira-García, José L; Echevarría, Miriam; López-Barneo, José; Toledo-Aral, Juan J

    2013-03-01

    Intrastriatal transplantation of dopaminergic carotid body (CB) cells ameliorates parkinsonism in animal models and, with less efficacy, in Parkinson's disease patients. CB-based cell therapy was initially proposed because of its high dopamine content. However, later studies suggested that its beneficial effect might be due to a trophic action exerted on nigrostriatal neurons. Compatible with this concept are the high levels of neurotrophic factors encountered in CB cells. To test experimentally this idea, unilateral striatal transplants were performed with a sham graft in the contralateral striatum, as a robust internal control. Thereafter, the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6, -tetrahydropyridine was injected during 3 months. CB grafts protected from degeneration ipsilateral nigral dopaminergic neurons projecting to the transplant in a dose-dependent manner regarding size and glial cell line-derived neurotrophic factor expression. Grafts performed at different times after the onset of the neurotoxic treatment demonstrated with histological and behavioral methods protection and repair of the nigrostriatal pathway by CB transplants. This study provides a mechanistic explanation for the action of CB transplants on parkinsonian models. It should also help to improve cell therapy approaches to Parkinson's disease. PMID:22743091

  18. Histochemical demonstration of tripeptidyl aminopeptidase I in the rat carotid body.

    PubMed

    Atanasova, Dimitrinka; Lazarov, Nikolai

    2015-03-01

    Tripeptidyl aminopeptidase I (TPP I) is a lysosomal exopeptidase that is widely distributed throughout the central nervous system (CNS) and internal organs in many mammalian species. The enzyme is involved in the breakdown of collagen and different peptides. The carotid body (CB) is the main peripheral arterial chemoreceptor playing an important role in the control of breathing and the autonomic control of cardiovascular function. In response to hypoxia its neuron-like glomus cells release a variety of peptide transmitters that trigger an action potential through the afferent fibers, thus conveying the chemosensory information to the CNS. In the present study we investigated the histochemical localization of TPP I in the CB of rats. Enzyme histochemistry showed high activity of TPP I in CB glomeruli. In particular, the glomus cells contained many TPP I-positive granules, while the glial-like sustentacular cells displayed a slightly fainter reaction. The interglomerular connective tissue was also weakly stained. The results show that both the parenchymal cells of the rat CB express, albeit with different intensity, TPP I. Taken together with our previous enzyme histochemical investigations on the rat CB, it seems likely that the glomus cells possess enzymatic equipment necessary for the neuropeptide intracellular and collagen extracellular initial degradation. These findings also suggest that TPP I is involved in the general turnover of chemotransmitters between glomus cells and sensory nerve endings which emphasizes its importance for chemoreception under hypoxic conditions. PMID:25636608

  19. Central role of carotid body chemoreceptors in disordered breathing and cardiorenal dysfunction in chronic heart failure

    PubMed Central

    Marcus, Noah J.; Del Rio, Rodrigo; Schultz, Harold D.

    2014-01-01

    Oscillatory breathing (OB) patterns are observed in pre-term infants, patients with cardio-renal impairment, and in otherwise healthy humans exposed to high altitude. Enhanced carotid body (CB) chemoreflex sensitivity is common to all of these populations and is thought to contribute to these abnormal patterns by destabilizing the respiratory control system. OB patterns in chronic heart failure (CHF) patients are associated with greater levels of tonic and chemoreflex-evoked sympathetic nerve activity (SNA), which is associated with greater morbidity and poor prognosis. Enhanced chemoreflex drive may contribute to tonic elevations in SNA by strengthening the relationship between respiratory and sympathetic neural outflow. Elimination of CB afferents in experimental models of CHF has been shown to reduce OB, respiratory-sympathetic coupling, and renal SNA, and to improve autonomic balance in the heart. The CB chemoreceptors may play an important role in progression of CHF by contributing to respiratory instability and OB, which in turn further exacerbates tonic and chemoreflex-evoked increases in SNA to the heart and kidney. PMID:25505417

  20. Interleukin-1β promotes the neurogenesis of carotid bodies by stimulating the activation of ERK1/2.

    PubMed

    Xue, Fen; Liu, Ling; Fan, Juan; He, ShanShan; Li, Rui; Peng, Zheng-Wu; Wang, Bai-Ren

    2015-12-01

    The carotid body (CB) is a complex sensory organ that functions to sense homeostatic O2 in the blood. Previous studies have shown that CBs express interleukin (IL)-1 receptor type I and that the chemosensitivity of CBs is increased following stimulation with pro-inflammatory cytokines. However, the effects of pro-inflammatory cytokines, such as IL-1β, on the neurogenesis of CB are unclear. Thus, in this study, we aimed to assess the effects of IL-1β and intermittent hypobaric hypoxia (IHH) plus IL-1β on the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, tyrosine hydroxylase (TH) and the expression of nestin, a well-established stem cell marker in the nervous system. The results showed that TH, nestin expression and ERK1/2 phosphorylation were increased in the rat CB following intraperitoneal injection of IL-1β. Moreover, IL-1β had additive effects on IHH. These results suggested that the plasticity of CB was increased following treatment with IL-1β and that ERK1/2 may be involved in neurogenic signaling in CBs. PMID:26327233

  1. Carotid intima media thickness is associated with body fat abnormalities in HIV-infected patients

    PubMed Central

    2014-01-01

    Background HIV-infected patients may be at increased risk of cardiovascular (CV) events, and lipodystrophy is generally associated with proatherogenic metabolic disturbances. Carotid intima-media thickness (cIMT) has been used as a surrogate marker for atherosclerosis and it has been shown to be an independent risk factor for CV disease. Our objective was to evaluate cIMT in HIV-infected patients on combined anti-retroviral therapy (cART) with and without lipodystrophy defined by fat mass ratio (L-FMR), and to determine the association of lipodystrophy and visceral obesity [(visceral (VAT), subcutaneous adipose tissue (SAT) volume and VAT/SAT ratio, objectively evaluated by CT scan] with cIMT. Methods Cross-sectional study of 199 HIV-infected patients. Body composition by DXA and abdominal CT, lipids, blood pressure, inflammatory markers, and cIMT by ultrasonography were performed. L-FMR was defined as the ratio of the percentage of trunk fat mass to the percentage of lower limb fat mass by DXA. Categorical variables were compared using the chi-square or Fisher’s exact test. Spearman correlation coefficients were estimated to study the association between cIMT and clinical and metabolic characteristics. Means of cIMT, adjusted for age, were calculated, using generalized linear models. Results L-FMR was present in 41.2% of patients and cIMT was higher in these patients [0.81 (0.24) vs. 0.76 (0.25); p = 0.037)]. Lipodystrophic patients had higher VAT and VAT/SAT ratio and lower SAT. cIMT was associated with lipodystrophy evaluated by FMR, trunk fat, total abdominal fat, VAT and VAT/SAT ratio. No association was observed between cIMT and leg fat mass. Using generalized linear models, cIMT means were adjusted for age and no significant differences remained after this adjustment. The adjusted mean of cIMT was 0.787 (95% CI: 0.751-0.823) in patients without lipodystrophy, and 0.775 (95% CI: 0.732-0.817) in those with lipodystrophy (p = 0.671). Conclusions

  2. Pharmacology of pH effects on carotid body chemoreceptors in vitro.

    PubMed

    Eyzaguirre, C; Zapata, P

    1968-04-01

    1. The carotid body and the carotid nerve were removed from anaesthetized cats and placed in a small Perspex channel through which Locke solution (at various pH values and usually equilibrated with 50% O(2) in N(2)) was allowed to flow. The glomus was immersed in the flowing solution while the nerve was lifted into oil covering the saline. Sensory discharges were recorded from the nerve and their frequency was used as an index of receptor activity. At times, a small segment of carotid artery, containing pressoreceptor endings, was removed together with the glomus. In this case, pressoreceptor discharges were recorded from the nerve.2. The amplitude of either chemo- or pressoreceptor discharges was not changed by strong acid solutions. Acid decreased the frequency of the baroreceptor discharges only when pH fell to less than 4.0. Solutions at low pH increased the chemosensory discharge, but acid depressed the increased chemoreceptor discharge elicited by KCl. These experiments indicated that H(+) ions probably acted as membrane ;stabilizers' without depolarizing either the nerve fibres or endings.3. Acid solutions increased the action of acetylcholine chloride (AChCl) (100-200 mug) on chemoreceptors. This effect probably was due either to inactivation of tissue cholinesterase or to enhanced sensitivity of the sensory endings to ACh.4. Choline chloride (10(-3)M), which favours ACh synthesis, protected the preparation against decay during prolonged experimentation. Hemicholinium-3 (HC-3), which blocks ACh synthesis in low concentrations (10(-5)M), depressed the chemosensory response to acid and to hypoxia when such stimuli were applied repeatedly. This concentration of HC-3 did not change effects of applied ACh.5. Substances which affect ACh release markedly changed the chemoreceptor discharge increase induced by acidity and other forms of stimulation. In the absence of Ca(2+), acid, anoxia, and interruption of flow provoked receptor depression while receptor

  3. Urinary miR-29 Correlates with Albuminuria and Carotid Intima-Media Thickness in Type 2 Diabetes Patients

    PubMed Central

    Zhao, Wenbo; Wang, Cheng; Zhang, Jun; Liu, Xun; Li, Yuanqing; Paudel, Sujay Dutta; Wang, Qianqian; Lou, Tanqi

    2013-01-01

    Background Cell-free microRNAs stably and abundantly exist in body fluids and emerging evidence suggests cell-free microRNAs as novel and non-invasive disease biomarker. Deregulation of miR-29 is involved in the pathogenesis of diabetic nephropathy and insulin resistance thus may be implicated in diabetic vascular complication. Therefore, we investigated the possibility of urinary miR-29 as biomarker for diabetic nephropathy and atherosclerosis in patients with type 2 diabetes. Methods 83 patients with type 2 diabetes were enrolled in this study, miR-29a, miR-29b and miR-29c levels in urine supernatant was determined by TaqMan qRT-PCR, and a synthetic cel-miR-39 was added to the urine as a spike-in control before miRNAs extraction. Urinary albumin excretion rate and urine albumin/creatinine ratio, funduscopy and carotid ultrasound were used for evaluation of diabetic vascular complication. The laboratory parameters indicating blood glucose level, renal function and serum lipids were also collected. Results Patients with albuminuria (n = 42, age 60.62±12.00yrs) showed significantly higher comorbidity of diabetic retinopathy (p = 0.015) and higher levels of urinary miR-29a (p = 0.035) compared with those with normoalbuminuria (n = 41, age 58.54±14.40yrs). There was no significant difference in urinary miR-29b (p = 0.148) or miR-29c level (p = 0.321) between groups. Urinary albumin excretion rate significantly correlated with urinary miR-29a level (r = 0.286, p = 0.016), while urinary miR-29b significantly correlated with carotid intima-media thickness (cIMT) (r = 0.286, p = 0.046). Conclusion Urinary miR-29a correlated with albuminuria while urinary miR-29b correlated with carotid intima-media thickness (cIMT) in patients with type 2 diabetes. Therefore, they may have the potential to serve as alternative biomarker for diabetic nephropathy and atherosclerosis in type 2 diabetes. PMID:24349318

  4. Acute hypoxia modifies cAMP levels induced by inhibitors of phosphodiesterase-4 in rat carotid bodies, carotid arteries and superior cervical ganglia

    PubMed Central

    Nunes, Ana R; Batuca, Joana R; Monteiro, Emília C

    2010-01-01

    Background and purpose: Phosphodiesterase (PDE) inhibitors are useful to treat hypoxia-related diseases and are used in experiments studying the effects of oxygen on 3′-5′-cyclic adenosine monophosphate (cAMP) production. We studied the effects of acute hypoxia on cAMP accumulation induced by PDE inhibitors in oxygen-specific chemosensors, the carotid bodies (CBs) and in non-chemosensitive CB-related structures: carotid arteries (CAs) and superior cervical ganglia (SCG). Experimental approach: Concentration–response curves for the effects of a non-specific PDE inhibitor [isobutylmethylxanthine (IBMX) ], PDE4 selective inhibitors (rolipram, Ro 20-1724) and a PDE2 selective inhibitor (erythro-9-(2-hydroxy-3-nonyl)adenine) on cAMP levels were obtained in normoxic (20% O2/5% CO2) or hypoxic (5% O2/5% CO2) conditions. Key results: Responses to the PDE inhibitors were compatible with the presence of PDE4 in rat CBs, CAs and SCG but in the absence of PDE2 in CAs and CBs. Acute hypoxia enhanced the effects of IBMX and PDE4 inhibitors on cAMP accumulation in CAs and CBs. In SCG, acute hypoxia reduced cAMP accumulation induced by all the four PDE inhibitors tested. Differences between the effects of Ro 20-1724 and rolipram on cAMP were found in CAs and CBs during hypoxia. Conclusions and implications: The effects of PDE4 inhibitors could be potentiated or inhibited by acute hypoxia depending on the PDE isoforms of the tissue. The similarities between the characterization of PDE4 inhibitors at the CBs and CAs, under normoxia and hypoxia, did not support a specific role for cAMP in the oxygen-sensing machinery at the CB and suggested that no direct CB-mediated, hyperventilatory, adverse effects would be expected with administration of PDE4 inhibitors. PMID:20082613

  5. Intermittent Hypoxia-Induced Carotid Body Chemosensory Potentiation and Hypertension Are Critically Dependent on Peroxynitrite Formation

    PubMed Central

    Moya, Esteban A.; Arias, Paulina; Varela, Carlos; Oyarce, María P.; Del Rio, Rodrigo; Iturriaga, Rodrigo

    2016-01-01

    Oxidative stress is involved in the development of carotid body (CB) chemosensory potentiation and systemic hypertension induced by chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea. We tested whether peroxynitrite (ONOO−), a highly reactive nitrogen species, is involved in the enhanced CB oxygen chemosensitivity and the hypertension during CIH. Accordingly, we studied effects of Ebselen, an ONOO− scavenger, on 3-nitrotyrosine immunoreactivity (3-NT-ir) in the CB, the CB chemosensory discharge, and arterial blood pressure (BP) in rats exposed to CIH. Male Sprague-Dawley rats were exposed to CIH (5% O2, 12 times/h, 8 h/day) for 7 days. Ebselen (10 mg/kg/day) was administrated using osmotic minipumps and BP measured with radiotelemetry. Compared to the sham animals, CIH-treated rats showed increased 3-NT-ir within the CB, enhanced CB chemosensory responses to hypoxia, increased BP response to acute hypoxia, and hypertension. Rats treated with Ebselen and exposed to CIH displayed a significant reduction in 3-NT-ir levels (60.8 ± 14.9 versus 22.9 ± 4.2 a.u.), reduced CB chemosensory response to 5% O2 (266.5 ± 13.4 versus 168.6 ± 16.8 Hz), and decreased mean BP (116.9 ± 13.2 versus 82.1 ± 5.1 mmHg). Our results suggest that CIH-induced CB chemosensory potentiation and hypertension are critically dependent on ONOO− formation. PMID:26798430

  6. An evaluation on management of carotid body tumour (CBT). A twelve years experience*

    PubMed Central

    BOSCARINO, G.; PARENTE, E.; MINELLI, F.; FERRANTE, A.; SNIDER, F.

    2014-01-01

    Summary Objectives Carotid Body Tumor (CBT) is a rare lesion of the neuroendocrine system but it is the most common form of head and neck paraganglioma (PGL). Our objective is to discuss the optimal management of these lesions to provide the best outcome of patients treated by surgical resection. Patients and Methods A retrospective evaluation was obtained by review of the records of 20 patients with 26 CBT treated at our institution between 2000 and 2012. Primary tumor characteristics, diagnostic protocols, surgical treatment, short and long-term outcomes were collected and analyzed. Results A total of 26 CBTs resections were performed on 20 patients; the age range was 21–89 years. There was a female prevalence (14 women-80% and 6 men-20%). Familial cases occurred in 6 patients (30%); of these, 3 patients had bilateral lesions and 1 patient multiple paragangliomas. In all cases no lymph node metastasis was found. All lesions were grouped into three groups according to the latero-lateral diameter: Group I < 3 cm; Group II 3<>5cm; Group III >5cm. All patients were managed by surgical resection of the CBT. There were no operative deaths. Overall we found transitory neurological impairment in 15,3% and permanent neurological deficit in 7,6% of cases. No complications occurred in all resections of Group I tumors. In Group II only 1 resection was followed by dysphonia by recurrent nerve palsy (after vagal nerve en-bloc resection). In Group III only 1 resection was followed by permanent vagus nerve palsy. Conclusions Surgical removal of the tumor is the only treatment that can ensure a complete eradication of the disease. Family screening is of great importance in patients with hereditary forms. Careful preoperative planning of surgical procedure by integrated diagnostic imaging and a full mastery of the surgical technique can minimize the risk of the most common postoperative complications. Lifelong follow-up is mandatory to make early diagnosis of recurrent disease

  7. Carotid Body Ablation Abrogates Hypertension and Autonomic Alterations Induced by Intermittent Hypoxia in Rats.

    PubMed

    Del Rio, Rodrigo; Andrade, David C; Lucero, Claudia; Arias, Paulina; Iturriaga, Rodrigo

    2016-08-01

    Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, enhances carotid body (CB) chemosensory responses to hypoxia and produces autonomic dysfunction, cardiac arrhythmias, and hypertension. We tested whether autonomic alterations, arrhythmogenesis, and the progression of hypertension induced by CIH depend on the enhanced CB chemosensory drive, by ablation of the CB chemoreceptors. Male Sprague-Dawley rats were exposed to control (Sham) conditions for 7 days and then to CIH (5% O2, 12/h 8 h/d) for a total of 28 days. At 21 days of CIH exposure, rats underwent bilateral CB ablation and then exposed to CIH for 7 additional days. Arterial blood pressure and ventilatory chemoreflex response to hypoxia were measured in conscious rats. In addition, cardiac autonomic imbalance, cardiac baroreflex gain, and arrhythmia score were assessed during the length of the experiments. In separate experimental series, we measured extracellular matrix remodeling content in cardiac atrial tissue and systemic oxidative stress. CIH induced hypertension, enhanced ventilatory response to hypoxia, induced autonomic imbalance toward sympathetic preponderance, reduced baroreflex gain, and increased arrhythmias and atrial fibrosis. CB ablation normalized blood pressure, reduced ventilatory response to hypoxia, and restored cardiac autonomic and baroreflex function. In addition, CB ablation reduced the number of arrhythmias, but not extracellular matrix remodeling or systemic oxidative stress, suggesting that reductions in arrhythmia incidence during CIH were related to normalization of cardiac autonomic balance. Present results show that autonomic alterations induced by CIH are critically dependent on the CB and support a main role for the CB in the CIH-induced hypertension. PMID:27381902

  8. Study of the effects of age and body mass index on the carotid wall vibration: extraction methodology and analysis.

    PubMed

    Yousefi Rizi, Fereshteh; Setarehdan, Seyed Kamaledin; Behnam, Hamid; Alizadeh Sani, Zahra

    2014-07-01

    This study aims to non-invasively extract the vibrations of the carotid wall and evaluate the changes in the carotid artery wall caused by age and obesity. Such evaluation can increase the possibility of detecting wall stiffness and atherosclerosis in its early stage. In this study, a novel method that uses a phase-tracking method based on the continuous wavelet transform calculates the carotid wall motion from the ultrasound radio frequency signals. To extract the high-frequency components of the wall motion, wall vibration, the empirical mode decomposition was then used. The posterior wall (intima-media) motion and vibration were extracted for 54 healthy volunteers (mean age: 33.87 ± 14.73 years), including 13 overweight subjects (body mass index > 25) and 14 female participants using their radio frequency signals. The results showed that the dominant frequency of the wall vibration correlates with age (r = -0.5887, p < 0.001) and body mass index (r = -0.4838, p < 0.001). The quantitative analysis further demonstrated that the dominant frequency of the vibration in the radial direction of the carotid wall decreases by age and is lower in overweight subjects. Besides, the peak-to-peak amplitude of the wall vibration showed significant correlations with age (r = -0.5456, p < 0.001) and body mass index (r = -0.5821, p < 0.001). The peak-to-peak amplitude also decreases by age and is lower in overweight subjects. However, there were no significant correlations between these features of the wall vibrations and systolic/diastolic blood pressure and sex. Our proposed measures were certified using the calculated arterial stiffness indices. The average power spectrum of the elderly subjects'wall motion in the frequency range of the wall vibration (>100 Hz) is decreased more in comparison with the young subjects. Our results revealed that the proposed method may be useful for detecting the stiffness and distortion in the carotid wall that occur prior to wall thickening

  9. Properties of a transient K+ current in chemoreceptor cells of rabbit carotid body.

    PubMed Central

    López-López, J R; De Luis, D A; Gonzalez, C

    1993-01-01

    1. Adult rabbit carotid body chemoreceptor cells, enzymatically dispersed and short-term cultured, exhibit an inactivating outward K+ current that is reversibly inhibited by low PO2. In the present work we have characterized the biophysical and pharmacological properties of this current using the whole-cell voltage clamp recording technique. 2. Inactivating current was recorded after blockage of Ca2+ currents with extracellular Co2+, Cd2+, or after complete washing out of Ca2+ channels. 3. The threshold of activation of this inactivating current was about -40 mV. Current activated very quickly (mean rise time 4.8 +/- 0.42 ms at +60 mV) but inactivated more slowly. Inactivation was well fitted by two exponentials with time constants of 79.7 +/- 6.6 and 824 +/- 42.8 ms (at +40 mV). The inactivation process showed a little voltage dependence. 4. The steady-state inactivation was well fitted by a Boltzman function. Inactivation was fully removed at potentials negative to -80 mV and was complete at voltages near -10 mV; 50% inactivation occurred at -41 mV. 5. Recovery from inactivation had several components and was voltage dependent. Initial recovery was fast, but full recovery, even at -100 mV, required more than 30 s. 6. Inactivating current was selectively blocked by 4-aminopyridine (4-AP), in a dose-dependent manner (IC50, 0.2 mM). The duration of chemoreceptor cells action potentials was augmented by 1 mM 4-AP from 2.3 +/- 0.36 to 7.0 +/- 0.25 ms at 0 mV. Tetraethylamonium (TEA), at concentrations above 5 mM, blocked inactivating and non-inactivating components of the whole K+ current. 7. Inactivating current was modulated by cyclic AMP (cAMP). Bath application of 2 mM dibutyryl cAMP reduced peak amplitude by 18.7 +/- 2.9% (at +30 mV) and slowed down the rise time of the current. The effect was not voltage dependent. Forskolin (10-20 microM) also affected inactivating current, by accelerating the inactivation process. In the same preparations neither dibutyryl c

  10. Properties of ionic currents from isolated adult rat carotid body chemoreceptor cells: effect of hypoxia.

    PubMed Central

    López-López, J R; González, C; Pérez-García, M T

    1997-01-01

    1. The electrical properties of chemoreceptor cells from neonatal rat and adult rabbit carotid bodies (CBs) are strikingly different. These differences have been suggested to be developmental and/or species related. To distinguish between the two possibilities, the whole-cell configuration of the patch-clamp technique was used to characterize the ionic currents present in isolated chemoreceptor cells from adult rat CBs. Since hypoxia-induced inhibition of O2-sensitive K+ currents is considered a crucial step in O2 chemoreception, the effect of hypoxia on the adult rat chemoreceptor cell currents was also studied. 2. Outward currents were carried mainly by K+, and two different components could be distinguished: a Ca(2+)-dependent K+ current (IK(Ca)) sensitive to Cd2+ and charybdotoxin (CTX), and a Ca(2+)-insensitive, voltage-dependent K+ current (IK(V)). IK(V) showed a slow voltage-dependent activation (time constant (tau) of 87.4 ms at -20 mV and 8.8 ms at +60 mV) and a very slow inactivation, described by the sum of two exponentials (tau 1 = 684 +/- 150 ms and tau 2 = 4.96 +/- 0.76 s at + 30 mV), that was almost voltage insensitive. The kinetic and pharmacological properties of IK(V) are typical of a delayed rectifier K+ channel. 3. Voltage-dependent Ca2+ currents (ICa) were present in nineteen of twenty-seven cells. TTX-sensitive Na+ currents were also observed in about 10% of the cells. 4. Low PO2 (< 10 mmHg) reduced the whole outward current amplitude by 22.17 +/- 1.96% (n = 27) at +20 mV. This effect was absent in the presence of Cd2+. Since low PO2 did not affect ICa, we conclude that hypoxia selectively blocks IK(Ca). 5. The properties of the currents recorded in adult rat chemoreceptor cells, including the specific inhibition of IK(Ca) by hypoxia, are similar to those reported in neonatal rat CB cells, implying that the differences between rat and rabbit chemoreceptor cells are species related. PMID:9080372

  11. Endovascular Treatment of a Carotid Dissecting Pseudoaneurysm in a Patient with Ehlers-Danlos Syndrome Type IV with Fatal Outcome

    SciTech Connect

    Lim, Siok Ping Duddy, Martin J.

    2008-01-15

    We present a patient with Ehlers-Danlos syndrome type IV (EDS IV) with a carotid dissecting pseudoaneurysm causing severe carotid stenosis. This lesion was treated endovascularly. Unfortunately, the patient died of remote vascular catastrophes (intracranial hemorrhage and abdominal aortic rupture). This unique case illustrates the perils of endovascular treatment of EDS IV patients and the need for preoperative screening for concomitant lesions. It also shows that a dissecting pseudoaneurysm can feasibly be treated with a covered stent and that closure is effective using Angioseal in patients with EDS IV.

  12. Long-term influence of neonatal hypoxia on catecholamine activity in carotid bodies and brainstem cell groups of the rat.

    PubMed Central

    Soulier, V; Dalmaz, Y; Cottet-Emard, J M; Lagercrantz, H; Pequignot, J M

    1997-01-01

    1. In order to determine the long-term influence of neonatal hypoxia on catecholaminergic activity in peripheral arterial chemoreceptors and brainstem noradrenergic cell groups (A1, A2, A5 and A6), 1-day-old male rat pups were subjected to hypoxia (10% oxygen) for 6 days and then supplied with normal air. Control animals were kept at normoxia from birth. Rats were killed at either 3 or 8 weeks of age. 2. The content of dopamine and noradrenaline in carotid bodies of neonatally hypoxic rats was increased at both 3 and 8 weeks of age. 3. Noradrenaline turnover was selectively decreased in the caudal portion of A2 (located in the area of chemosensory afferent projection) at 8 weeks of age (-76 +/- 2%), while this turnover was unaffected in rostral A2 cells. Noradrenergic activity in A1, A5 and A6 was altered by neonatal hypoxia in an age-dependent fashion. 4. The data suggest that neonatal hypoxia induces long-term changes in the basal activity of the carotid body and brainstem noradrenergic cell groups. Such changes might contribute to neuronal regulation of the delayed respiratory, arousal and neural sequelae associated with neonatal hypoxia. These changes could also be involved in the early programming of respiratory and blood pressure control. PMID:9032699

  13. An unusual presentation of foreign body in the common carotid artery.

    PubMed

    Lahiri, Somdatta; Ghosh, Shibajyoti; Sengupta, Goutam; Bakshi, Udayan

    2011-12-01

    Penetrating trauma to neck resulting in arteriovenous (AV) fistula and aneurysms involving the carotid system are uncommon injuries with life-threatening consequences. We report here a case of a young factory worker who developed a traumatic AV fistula with false aneurysm, with however, no other complications. He was successfully operated when he presented to us two months after the injury and is doing well in follow-up. PMID:23204711

  14. Lower body positive pressure application with an antigravity suit in acute carotid occlusion.

    PubMed

    Berthet, Karine; Lukaszewicz, Anne Claire; Bousser, Marie-Germaine; Payen, Didier

    2010-01-01

    The challenge in acute stroke is still to reperfuse as early as possible the ischemic territory. Since fibrinolytic therapies have a limited window with potential risk of bleeding, having a nonpharmacologic mean to recruit vessels in area surrounding necrosis might be useful. We propose here to use antigravity suit inflated at "venous" pressure levels to shift blood towards thoracic and brain territories. We report two cases of spectacular clinical recovery after acute carotid occlusion. PMID:20798842

  15. Endovascular repair of direct carotid-cavernous fistula in Ehlers-Danlos type IV.

    PubMed

    Linfante, Italo; Lin, Eugene; Knott, Eric; Katzen, Barry; Dabus, Guilherme

    2014-01-01

    Ehlers-Danlos syndrome (EDS) type IV is a collagen vascular disease with an autosomal dominant inheritance caused by COL3A1 mutation. Patients with EDS type IV can present with organ rupture, spontaneous arterial dissections and ruptured aneurysms. Because of their propensity to form arterial dissections, aneurysms and rupture, they can develop carotid-cavernous fistula (CCF) after minor trauma or spontaneously. In EDS, it has been reported that even conventional catheter diagnostic angiography may result in large artery dissections and vessel rupture. In addition, the treatment of CCF in EDS type IV can result in up to 59% mortality after initial treatment, of which 23% is attributed to direct complications of treatment. We present the case of a patient with EDS type IV who previously had spontaneous dissection and multiple pseudoaneurysms of both the iliac and femoral arteries and the distal abdominal aorta. Several years later the patient developed a direct type A CCF which was successfully treated with endovascular embolization using a transvenous approach with detachable coils. The literature pertaining to CCF in EDS type IV and its treatment is reviewed. PMID:24385391

  16. Endovascular repair of direct carotid-cavernous fistula in Ehlers-Danlos type IV.

    PubMed

    Linfante, Italo; Lin, Eugene; Knott, Eric; Katzen, Barry; Dabus, Guilherme

    2015-01-01

    Ehlers-Danlos syndrome (EDS) type IV is a collagen vascular disease with an autosomal dominant inheritance caused by COL3A1 mutation. Patients with EDS type IV can present with organ rupture, spontaneous arterial dissections and ruptured aneurysms. Because of their propensity to form arterial dissections, aneurysms and rupture, they can develop carotid-cavernous fistula (CCF) after minor trauma or spontaneously. In EDS, it has been reported that even conventional catheter diagnostic angiography may result in large artery dissections and vessel rupture. In addition, the treatment of CCF in EDS type IV can result in up to 59% mortality after initial treatment, of which 23% is attributed to direct complications of treatment. We present the case of a patient with EDS type IV who previously had spontaneous dissection and multiple pseudoaneurysms of both the iliac and femoral arteries and the distal abdominal aorta. Several years later the patient developed a direct type A CCF which was successfully treated with endovascular embolization using a transvenous approach with detachable coils. The literature pertaining to CCF in EDS type IV and its treatment is reviewed. PMID:24401479

  17. Role of voltage-dependent calcium channels in stimulus–secretion coupling in rabbit carotid body chemoreceptor cells

    PubMed Central

    Rocher, Asunción; Geijo-Barrientos, Emilio; Cáceres, Ana Isabel; Rigual, Ricardo; González, Constancio; Almaraz, Laura

    2005-01-01

    We have defined Ca2+ channel subtypes expressed in rabbit carotid body (CB) chemoreceptor cells and their participation in the stimulus-evoked catecholamine (CA) release. Ca2+ currents (ICa) activated at –30 mV, peaked at +10 mV and were fully blocked by 200 μm Cd2+. L-type channels (sensitive to 2 μm nisoldipine) activated at –30 mV and carried 21 ± 2% of total ICa. Non-L-type channels activated at potentials positive to –10 mV and carried: N channels (sensitive to 1 μm ω-conotoxin-GVIA) 16 ± 1% of total ICa, P/Q channels (sensitive to 3 μm ω-conotoxin-MVIIC after nisoldipine plus GVIA) 23 ± 3% of total ICa and R channels (resistant to all blockers combined) 40 ± 3% of total ICa. CA release induced by hypoxia, hypercapnic acidosis, dinitrophenol (DNP) and high K+o in the intact CB was inhibited by 79–98% by 200 μm Cd2+. Hypoxia, hypercapnic acidosis and DNP, depolarized chemoreceptor cells and eventually generated repetitive action potential discharge. Nisoldipine plus MVIIC nearly abolished the release of CAs induced by hypoxia and hypercapnic acidosis and reduced by 74% that induced by DNP. All these secretory responses were insensitive to GVIA. 30 and 100 mm K+o brought resting membrane potential (Em) of chemoreceptor cells (–48.1 ± 1.2 mV) to –22.5 and +7.2 mV, respectively. Thirty millimolar K+o-evoked release was abolished by nisoldipine but that induced by 100 mm K+o was mediated by activation of L, N, and P/Q channels. Data show that tested stimuli depolarize rabbit CB chemoreceptor cells and elicit CA release through Ca2+ entry via voltage-activated channels. Only L and P/Q channels are tightly coupled to the secretion of CA. PMID:15528240

  18. Aggressive change of a carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV.

    PubMed

    Kojima, Atsuhiro; Saga, Isako; Tomio, Ryosuke; Kosho, Tomoki; Hatamochi, Atsushi

    2015-06-01

    The authors report a rare case of a carotid-cavernous fistula (CCF) secondary to Ehlers-Danlos syndrome (EDS) type IV which showed an aggressive angiographical change.A 59-year-old woman presented with headache, right pulsatile tinnitus, and diplopia on the right side. The diagnostic angiography demonstrated a right CCF. Accordingly transarterial embolization of the fistula was attempted 5 days later. The initial right internal carotid angiography showed an aneurysm on the petrous portion of the internal carotid artery (ICA) which was not recognized in the diagnostic angiography. Spontaneous reduction of the shunt flow and long dissection of the ICA were also revealed. The aneurysm was successfully occluded with coils, and only minor shunt flow was shown on the final angiogram. EDS type IV was diagnosed with a skin biopsy for a collagen abnormality. After the operation, the stenosis of the right ICA gradually progressed, although there was no recurrence of the CCF.Interventional treatment for patients with EDS can cause devastating vascular complication. We should be aware of the possibility of EDS type IV when a spontaneous CCF shows unusual angiographical change because early diagnosis of EDS type IV is crucial for determination of the optimum treatment option. PMID:26015525

  19. 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 ...

  20. Body Type Attractiveness Preferences of the Aged.

    ERIC Educational Resources Information Center

    Portnoy, Enid J.

    A study explored the relationship between body types and four attraction dimensions (physical, social, task, and communication) as perceived by older adults (mean age 68). Subjects, 35 males and 73 females in private residences and senior citizen centers, were shown three same-sex body silhouettes representing the older ectomorph, mesomorph, and…

  1. Atorvastatin Treatment for Carotid Intima-Media Thickness in Chinese Patients With Type 2 Diabetes

    PubMed Central

    Fang, Na; Han, Wei; Gong, Dandan; Zou Chen; Fan, Yu

    2015-01-01

    Abstract Impact of atorvastatin on carotid intima-media thickness (CIMT) in patients with type 2 diabetes is still debating. The aim of our study is to investigate atorvastatin as adjuvant treatment on CIMT in Chinese patients with type 2 diabetes by conducting a meta-analysis based on the randomized controlled trials (RCTs). A systematic search of electronic database of the Pubmed, EMBASE, Cochrane Library, VIP database, China National Knowledge Infrastructure, and Wangfang up to January 2015 was conducted. Randomized controlled trials (RCTs) comparing atorvastatin adjuvant treatment to the hypoglycemic therapies or high-dose atorvastatin versus low-dose atorvastatin therapies for patients with type 2 diabetes were selected. A total of 14 RCTs involving 1345 patients were included. Adjuvant treatment with atorvastatin was associated with a significant reduction in CIMT (weighted mean difference [WMD] = −0.17 mm; 95% confidence interval [CI] −0.22 to −0.12). Compared with the low-dose atorvastatin, high-dose atorvastatin treatment was associated with a significant reduction in CIMT (WMD = −0.17 mm; 95% CI: −0.32 to −0.02). Adjuvant treatment with atorvastatin reduced serum total cholesterol, triglyceride, low-density lipoproteins, and high sensitivity C-reactive protein levels. However, atorvastatin had no significant impact on blood glucose levels. This meta-analysis demonstrated that treatment with atorvastatin significantly reduced CIMT in Chinese patients with type 2 diabetes. Moreover, high-dose atorvastatin appeared to have additional benefits in reducing CIMT than the low-dose atorvastatin. PMID:26554793

  2. Fatal Peritoneal Bleeding Following Embolization of a Carotid-Cavernous Fistula in Ehlers-Danlos Syndrome Type IV

    SciTech Connect

    Usinskiene, Jurgita; Mazighi, Mikael; Bisdorff, Annouk; Houdart, Emmanuel

    2006-12-15

    We report the case of a 25-year-old woman treated for a spontaneous carotid-cavernous fistula in a context of Ehlers-Danlos syndrome type IV. Embolization with a transvenous approach was achieved without complications; however, the patient died 72 hr later of massive intraperitoneal bleeding. At autopsy, no lesion of the digestive arteries was identified. Possible causes of this bleeding are discussed.

  3. Mannose-Binding Lectin Levels and Carotid Intima-Media Thickness in Type 2 Diabetic Patients

    PubMed Central

    Káplár, Miklós; Sweni, Shah; Kulcsár, Julianna; Cogoi, Barbara; Esze, Regina; Somodi, Sándor; Papp, Mária; Oláh, László; Magyar, Mária Tünde; Szabó, Katalin; Czuriga-Kovács, Katalin Réka; Hársfalvi, Jolán; Paragh, György

    2016-01-01

    Introduction. Mannose-binding lectin (MBL) activates complement system and has been suggested to play a role in vascular complications in diabetics. Carotid intima-media thickness (cIMT) detects subclinical atherosclerosis. We evaluated the association of MBL and IMT in type 2 diabetic (T2DM) patients. Methods. Serum MBL levels and cIMT were measured in a total of 103 diabetics and in 98 age-matched healthy controls. Results. There was no significant difference in MBL level in T2DM versus controls. As expected, IMT was significantly higher in T2DM patients than in controls (P = 0.001). In T2DM, the lowest cIMT was seen in patients with normal MBL level (500–1000) while cIMT continuously increased with both high MBL and absolute MBL deficiency states. This was especially significant in high MBL versus normal MBL T2DM patients (P = 0.002). According to multiple regression analysis the main predictors of IMT in T2DM are age (P < 0.003), ApoA level (P = 0.023), and the MBL (P = 0.036). Conclusions. Our results suggest a dual role of MBL as a risk factor for cIMT in T2DM. MBL may also be used as a marker of macrovascular disease, as both low and high levels indicate the susceptibility for atherosclerosis in T2DM. PMID:26640806

  4. Nonalcoholic Fatty Liver Disease is Associated with Increased Carotid Intima-Media Thickness in Type 1 Diabetic Patients

    PubMed Central

    Zhang, Lei; Guo, Kaifeng; Lu, Junxi; Zhao, Fangya; Yu, Haoyong; Han, Junfeng; Bao, Yuqian; Chen, Haibing; Jia, Weiping

    2016-01-01

    A growing body of evidence suggests that NAFLD is associated with an increased risk of incident CVD events both in patients without diabetes and in those with type 2 diabetes (T2DM). However, no published data are available regarding the association between NAFLD and C-IMT in T1DM. A total of 722 patients (371 men) with T1DM were included in this cross-sectional study. The main outcome measures were detection of NAFLD, C-IMT and classical risk factors. The mean age of the subjects was 46.2 years, and 51.1% were male. The prevalence of NAFLD was 15.9%. NAFLD patients had a markedly greater C-IMT (0.81 ± 0.25 vs. 0.69 ± 0.18 mm; p < 0.001) and frequency of carotid plaque (28.9% vs. 16.9%; p < 0.05) than those without fatty liver. Moreover, the differences in C-IMT remained after adjusting for potential confounders. A stepwise linear regression analysis revealed that age (standardized β, 0.326; p < 0.001), NAFLD (standardized β, 0.151, p < 0.001), and hsCRP (standardized β, 0.115, p = 0.008) were independently associated with C-IMT in all subjects. Our data show NAFLD is associated with elevated C-IMT in T1DM independent of conventional cardiovascular disease risk factors. PMID:27226159

  5. Sudden death due to rupture of the right internal carotid artery in neurofibromatosis type 1: A case report.

    PubMed

    Liang, Yue; Tong, Fang; Zhang, Lin; Li, Wenhe; Zhou, Yiwu

    2016-07-01

    Vascular involvement is a well-recognized manifestation of neurofibromatosis type 1 (NF1) which has the potential to be fatal when disrupted. We here present a case of sudden death due to the fatal arterial rupture resulted from infiltration of the neurofibromas. A 42-year-old man who suffered from NF1 presented a 1-h history of sudden onset of pain in his right cervical region. His condition worsened and became unconscious on his way to the emergency room. Despite resuscitation efforts, he died 30min later without regaining consciousness. Autopsy examination showed that a neurofibroma located around the right internal carotid artery, confirmed immunohistochemically with S-100, vimentin and CD34. Furthermore, proliferation of spindle cells positive for S-100 was seen in the wall of right internal carotid artery, which was disrupted and resulted in a hemorrhage. These findings suggest that the artery was disrupted by neurofibromas in the vascular wall, which led to fragility of the vessel. On the basis of these findings, we concluded that the cause of death was asphyxia resulting from airway obstruction compressed by the hematoma due to the arterial rupture. As the locality of the neurofibroma and hemorrhage were closed to the carotid baroreflex, we considered another possible mechanism of his sudden death, which could be cardiac inhibition induced by vagal stimulation. We hope this case will increase recognition of NF-1 vasculopathy when encountering any sudden death in NF1 patients. PMID:27497331

  6. Acute restraint stress increases carotid reactivity in type-I diabetic rats by enhancing Nox4/NADPH oxidase functionality.

    PubMed

    Moreira, Josimar D; Pernomian, Larissa; Gomes, Mayara S; Pernomian, Laena; Moreira, Rafael P; do Prado, Alejandro F; da Silva, Carlos H T P; de Oliveira, Ana M

    2015-10-15

    Hyperglycemia increases the generation of reactive oxygen species and affects systems that regulate the vascular tone including renin-angiotensin system. Stress could exacerbate intracellular oxidative stress during Diabetes upon the activation of angiotensin AT1/NADPH oxidase pathway, which contributes to the development of diabetic cardiovascular complications. For this study, type-I Diabetes was induced in Wistar rats by intraperitoneal injection of streptozotocin. 28 days after streptozotocin injection, the animals underwent to acute restraint stress for 3 h. Cumulative concentration-response curves for angiotensin II were obtained in carotid rings pre-treated or not with Nox or cyclooxygenase inhibitors. Nox1 or Nox4 expression and activity were assessed by Western blotting and lucigenin chemiluminescence, respectively. The role of Nox1 and Nox4 on reactive oxygen species generation was evaluated by flow cytometry and Amplex Red assays. Cyclooxygenases expression was assessed by real-time polymerase chain reaction. The contractile response evoked by angiotensin II was increased in diabetic rat carotid. Acute restraint stress increased this response in this vessel by mechanisms mediated by Nox4, whose local expression and activity in generating hydrogen peroxide are increased. The contractile hyperreactivity to angiotensin II in stressed diabetic rat carotid is also mediated by metabolites derived from cyclooxygenase-2, whose local expression is increased. Taken together, our findings suggest that acute restraint stress exacerbates the contractile hyperreactivity to angiotensin II in diabetic rat carotid by enhancing Nox4-driven generation of hydrogen peroxide, which evokes contractile tone by cyclooxygenases-dependent mechanisms. Finally, these findings highlight the harmful role played by acute stress in modulating diabetic vascular complications. PMID:26387612

  7. Congenital Absence of Internal Carotid Artery with Rare Type of Intercavernous Anastamosis and Ruptured Cerebral Aneurysm

    PubMed Central

    Alurkar, Anand; Oak, Sagar; Kori, Smita

    2016-01-01

    Congenital absence of Internal Carotid Artery (ICA) is a rare anomaly seen in <0.01% of the population. Various collateral circulations develop in these cases to maintain adequate cerebral perfusion. High incidence of aneurysms is reported in these cases. Complete evaluation is required to detect other abnormalities usually seen in these patients. We report a case of congenital absence of right ICA in a 39-year-old female who presented with Subarachnoid Haemorrhage (SAH) and had a Middle Cerebral Artery Aneurysm (MCA). The right MCA got supply from the intercavernous communication from the left internal carotid artery. Skull base Computed Tomogram (CT) confirmed the congenital absence of right ICA. She underwent successful surgical clipping for the aneurysm. The high incidence of aneurysms, collateral circulations, embryological development and postulated mechanisms of this anomaly were discussed. The exact aetiology behind the absence of ICA remains unclear. It is important to differentiate this condition from acquired stenosis/occlusion due to atherosclerosis and carotid dissection. Recognising the anomaly is important and gains even more significance during surgical planning in cases of direct aneurysm clipping, carotid endarterectomy and transphenoidal surgeries. PMID:27190916

  8. 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 ...

  9. The Effect of Sitagliptin on Carotid Artery Atherosclerosis in Type 2 Diabetes: The PROLOGUE Randomized Controlled Trial

    PubMed Central

    Oyama, Jun-ichi; Murohara, Toyoaki; Kitakaze, Masafumi; Ishizu, Tomoko; Sato, Yasunori; Kitagawa, Kazuo; Kamiya, Haruo; Ajioka, Masayoshi; Ishihara, Masaharu; Dai, Kazuoki; Sata, Masataka; Maemura, Koji; Tomiyama, Hirofumi; Higashi, Yukihito; Kaku, Kohei; Matsuhisa, Munehide; Yamashita, Kentaro; Bando, Yasuko K.; Kashihara, Naoki; Ueda, Shinichiro; Inoue, Teruo; Tanaka, Atsushi; Node, Koichi

    2016-01-01

    Background Experimental studies have suggested that dipeptidyl peptidase-4 (DPP-4) inhibitors provide cardiovascular protective effects. We performed a randomized study to evaluate the effects of sitagliptin added on to the conventional therapy compared with conventional therapy alone (diet, exercise, and/or drugs, except for incretin-related agents) on the intima-media thickness (IMT) of the carotid artery, a surrogate marker for the evaluation of atherosclerotic cardiovascular disease, in people with type 2 diabetes mellitus (T2DM). Methods and Findings We used a multicenter PROBE (prospective, randomized, open label, blinded endpoint) design. Individuals aged ≥30 y with T2DM (6.2% ≤ HbA1c < 9.4%) were randomly allocated to receive either sitagliptin (25 to 100 mg/d) or conventional therapy. Carotid ultrasound was performed at participating medical centers, and all parameters were measured in a core laboratory. Of the 463 enrolled participants with T2DM, 442 were included in the primary analysis (sitagliptin group, 222; conventional therapy group, 220). Estimated mean (± standard error) common carotid artery IMT at 24 mo of follow-up in the sitagliptin and conventional therapy groups was 0.827 ± 0.007 mm and 0.837 ± 0.007 mm, respectively, with a mean difference of −0.009 mm (97.2% CI −0.028 to 0.011, p = 0.309). HbA1c level at 24 mo was significantly lower with sitagliptin than with conventional therapy (6.56% ± 0.05% versus 6.72% ± 0.05%, p = 0.008; group mean difference −0.159, 95% CI −0.278 to −0.041). Episodes of serious hypoglycemia were recorded only in the conventional therapy group, and the rate of other adverse events was not different between the two groups. As it was not a placebo-controlled trial and carotid IMT was measured as a surrogate marker of atherosclerosis, there were some limitations of interpretation. Conclusions In the PROLOGUE study, there was no evidence that treatment with sitagliptin had an additional effect on the

  10. 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. PMID:27061654

  11. Regulation of hypoxia-inducible factor-α isoforms and redox state by carotid body neural activity in rats

    PubMed Central

    Peng, Ying-Jie; Yuan, Guoxiang; Khan, Shakil; Nanduri, Jayasri; Makarenko, Vladislav V; Reddy, Vaddi Damodara; Vasavda, Chirag; Kumar, Ganesh K; Semenza, Gregg L; Prabhakar, Nanduri R

    2014-01-01

    Previous studies reported that chronic intermittent hypoxia (CIH) results in an imbalanced expression of hypoxia-inducible factor-α (HIF-α) isoforms and oxidative stress in rodents, which may be due either to the direct effect of CIH or indirectly via hitherto uncharacterized mechanism(s). As neural activity is a potent regulator of gene transcription, we hypothesized that carotid body (CB) neural activity contributes to CIH-induced HIF-α isoform expression and oxidative stress in the chemoreflex pathway. Experiments were performed on adult rats exposed to CIH for 10 days. Rats exposed to CIH exhibited: increased HIF-1α and decreased HIF-2α expression; increased NADPH oxidase 2 and decreased superoxide dismutase 2 expression; and oxidative stress in the nucleus tractus solitarius and rostral ventrolateral medulla as well as in the adrenal medulla (AM), a major end organ of the sympathetic nervous system. Selective ablation of the CB abolished these effects. In the AM, sympathetic activation by the CB chemoreflex mediates CIH-induced HIF-α isoform imbalance via muscarinic acetylcholine receptor-mediated Ca2+ influx, and the resultant activation of mammalian target of rapamycin pathway and calpain proteases. Rats exposed to CIH presented with hypertension, elevated sympathetic activity and increased circulating catecholamines. Selective ablation of either the CB (afferent pathway) or sympathetic innervation to the AM (efferent pathway) abolished these effects. These observations uncover CB neural activity-dependent regulation of HIF-α isoforms and the redox state by CIH in the central and peripheral nervous systems associated with the chemoreflex. PMID:24973414

  12. Dissociation between blood pressure and heart rate response to hypoxia after bilateral carotid body removal in men with systolic heart failure.

    PubMed

    Niewinski, Piotr; Janczak, Dariusz; Rucinski, Artur; Tubek, Stanislaw; Engelman, Zoar J; Jazwiec, Przemyslaw; Banasiak, Waldemar; Sobotka, Paul A; Hart, Emma C J; Paton, Julian F R; Ponikowski, Piotr

    2014-03-01

    While the ventilatory response to hypoxia is known to be mediated by the carotid bodies, the origin of the haemodynamic alterations evoked by hypoxia is less certain. Bilateral carotid body removal (CBR) performed to treat congestive heart failure may serve as a model to improve our understanding of haemodynamic responses to hypoxia in humans. We studied six congestive heart failure patients before and 1 month after CBR [median (interquartile range): age, 58.5 (56-61) years old; and ejection fraction, 32 (25-34)%]. Peripheral chemosensitivity (hypoxic ventilatory response) was equated to the slope relating lowest oxygen saturation to highest minute ventilation following exposures to hypoxia. Likewise, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) slopes were calculated as slopes relating the lowest oxygen saturations to the highest SBP, DBP and HR responses. We found that CBR reduces the hypoxic ventilatory response (91%, P < 0.05), SBP (71%, P < 0.05) and DBP slopes (59%, P = 0.07). In contrast, the HR slope remained unchanged. The dissociation between the blood pressure and HR responses after CBR shows involvement of a different chemoreceptive site(s) maintaining the response to acute hypoxia. We conclude that carotid bodies are responsible for ventilatory and blood pressure responses, while the HR response might be mediated by the aortic bodies. The significant reduction of the blood pressure response to hypoxia after CBR suggests a decrease in sympathetic tone, which is of particular clinical relevance in congestive heart failure. PMID:24243836

  13. 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

  14. 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

  15. Severe compression of a bailout self-expanding chimney stent for rescuing the miscoverage of left common carotid artery during TEVAR of a type B aortic dissection.

    PubMed

    Wang, Lixin; Guo, Daqiao; Jiang, Junhao; Shi, Zhenyu; Fu, Weiguo; Wang, Yuqi

    2014-04-01

    A 54-year-old man who suffered from paraplegia due to type B aortic dissection was treated with a Valiant stent-graft. However, attempts to gain secure proximal sealing resulted in an inadvertent coverage of the left common carotid artery by the endograft. The blood flow in the left common carotid artery was restored by a transcarotid Smart Control stent in a chimney fashion. At 6- and 18-month follow-up, computed tomography scan showed that the chimney stent was severely compressed by the stent graft, although the patient remained neurologically asymptomatic. PMID:24309751

  16. 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 ...

  17. Heteromeric TASK-1/TASK-3 is the major oxygen-sensitive background K+ channel in rat carotid body glomus cells.

    PubMed

    Kim, Donghee; Cavanaugh, Eric J; Kim, Insook; Carroll, John L

    2009-06-15

    Carotid body (CB) glomus cells from rat express a TASK-like background K+ channel that is believed to play a critical role in the regulation of excitability and hypoxia-induced increase in respiration. Here we studied the kinetic behaviour of single channel openings from rat CB cells to determine the molecular identity of the 'TASK-like' K+ channels. In outside-out patches, the TASK-like background K+ channel in CB cells was inhibited >90% by a reduction of pH(o) from 7.3 to 5.8. In cell-attached patches with 140 mM KCl and 1 mM Mg2+ in the bath and pipette solutions, two main open levels with conductance levels of approximately 14 pS and approximately 32 pS were recorded at a membrane potential of -60 mV. The K+ channels showed kinetic properties similar to TASK-1 (approximately 14 pS), TASK-3 (approximately 32 pS) and TASK-1/3 heteromer (approximately 32 pS). The presence of three TASK isoforms was tested by reducing [Mg2+](o) to approximately 0 mM, which had no effect on the conductance of TASK-1, but increased those of TASK-1/3 and TASK-3 to 42 pS and 74 pS, respectively. In CB cells, the reduction of [Mg2+](o) to approximately 0 mM also caused the appearance of approximately 42 pS (TASK-1/3-like) and approximately 74 pS (TASK-3-like) channels, in addition to the approximately 14 pS (TASK-1-like) channel. The 42 pS channel was the most abundant, contributing approximately 75% of the current produced by TASK-like channels. Ruthenium red (5 microM) had no effect on TASK-1 and TASK-1/3, but inhibited TASK-3 by 87%. In CB cells, ruthenium red caused approximately 12% inhibition of TASK-like activity. Methanandamide reduced the activity of all three TASKs by 80-90%, and that of TASK-like channels in CB cell also by approximately 80%. In CB cells, hypoxia caused inhibition of TASK-like channels, including TASK-1/3-like channels. These results show that TASK-1, TASK-1/3 and TASK-3 are all functionally expressed in isolated CB cells, and that the TASK-1/3 heteromer

  18. Association of retinopathy and intima media thickness of common carotid artery in type 2 diabetic patients

    PubMed Central

    Momeni, Ali; Dyani, Mohamad Ali; Ebrahimi, Elnaz; Sedehi, Morteza; Naderi, Afsaneh

    2015-01-01

    Background: This study was carried out in order to evaluate the relationship between retinopathy and carotid intima-media thickness (CIMT). Materials and Methods: In a cross-sectional study, 154 diabetic patients who had a history of diabetic disease were evaluated in two equal groups of 77 patients with and without retinopathy, respectively. CIMT was evaluated in all of the patients. Results: Mean age of the patients was 59.65 ± 9.37 years. Mean CIMT of all patients was 0.84 ± 0.18. CIMT of patients with retinopathy was significantly greater than patients without retinopathy (P < 0.001). CIMT also correlated with age, duration of diabetes, systolic blood pressure, blood urea nitrogen, and serum creatinine. Conclusion: CIMT may be used as a simple, available and noninvasive method for screening of macro and microvascular complication of diabetic patients. PMID:26109997

  19. Transvenous Embolization for Carotid-Cavernous Fistula in a Patient with Vascular Type of Ehlers-Danlos Syndrome—Direct Superior Ophthalmic Vein Approach: Case Report

    PubMed Central

    TANAKA, Teppei; HAYAKAWA, Motoharu; SADATO, Akiyo; ADACHI, Kazuhide; WATABE, Takeya; MAEDA, Shingo; OHMURA, Masahiro; HIROSE, Yuichi

    2014-01-01

    The vascular type of Ehlers-Danlos syndrome (vEDS) is an autosomal dominant hereditary disease characterized by connective tissue fragility throughout the body, including the arteries, viscera, and gastrointestinal tract. We report a case in which we performed transvenous embolization (TVE) via direct superior ophthalmic vein (SOV) approach to treat a direct carotid-cavernous fistula (CCF) in a patient with Ehlers-Danlos syndrome (EDS). The patient was a 37-year-old woman who developed tinnitus in her left ear and a headache during examination in the outpatient clinic of another hospital in order to make a definitive diagnosis of vEDS, and she was referred to our hospital and examined. Based on the results of all of the studies she was diagnosed with a CCF. Conservative treatment was attempted, but was not very effective. Because of progressing aphasia, TVE was performed via the SOV direct cut. There were no intraoperative or postoperative complications. It has been reported that cerebral angiography is generally contraindicated in vEDS and that the morbimortality associated with endovascular treatment is very high. When performing treatment it is necessary to be sufficiently aware of the risks it entails. PMID:24418783

  20. Multiple strokes and bilateral carotid dissections: a fulminant case of newly diagnosed Ehlers-Danlos syndrome type IV.

    PubMed

    Dohle, C; Baehring, J M

    2012-07-15

    Ehlers-Danlos Syndrome is a rare group of inheritable disorders resulting in abnormal collagen production, leading to skin fragility, joint hypermobility and easy bruising. Six major subtypes have been identified, of which Type IV most often leads to neurovascular complications, may lead to inner organ rupture and overall has the worst prognosis. Early recognition followed by genetic testing is key, since this diagnosis will guide decision making in the management of complications, influence the choice of antiplatelet medications versus anticoagulants and allow for potentially affected family members to be identified, undergo genetic testing and reproductive counseling. We here report the case of a 50 year old woman with a fulminant presentation of Ehlers Danlos Syndrome Type IV, including bilateral carotid and vertebral artery dissection, multiple strokes and liver rupture. Of note, this patient did not have a known history or obvious clinical features of connective tissue disease. Genetic testing confirmed the diagnosis. Review of her family history revealed multiple family members with a history of aortic dissection or aneurysm rupture. This case illustrates that Ehlers Danlos Syndrome Type IV is an important differential diagnosis even in adult patients without a known history of connective tissue disease and no prior complications. PMID:22559935

  1. Microsurgical anatomy of the human carotid body (glomus caroticum): Features of its detailed topography, syntopy and morphology.

    PubMed

    Schulz, Sissy-Amelie; Wöhler, Aliona; Beutner, Dirk; Angelov, Doychin N

    2016-03-01

    The human glomus caroticum (GC) is not readily accessible during ordinary anatomical teaching courses because of insufficient time and difficulties encountered in the preparation. Accordingly, most anatomical descriptions of its location, relationship to neighboring structures, size and shape are supported only by drawings, but not by photographs. The aim of this study is to present the GC with all associated roots and branches. Following microscope-assisted dissection and precise photo-documentation, a detailed analysis of location, syntopy and morphology was performed. We carried out this study on 46 bifurcations of the common carotid artery (CCA) into the external (ECA) and internal (ICA) carotid arteries and identified the GC in 40 (91%) of them. We found significant variations regarding the location of the GC and its syntopy: GC was associated with CCA (42%), ECA (28%) and ICA (30%) lying on the medial or lateral surface (82% or 13%, respectively) or exactly in the middle (5%) of the bifurcation. The short and long diameter of its oval form varied from 1.0×2.0 to 5.0×5.0mm. Connections with the sympathetic trunk (100%), glossopharyngeal (93%), vagus (79%) and hypoglossal nerve (90%) could be established in 29 cadavers. We conclude that precise knowledge of this enormous variety might be very helpful not only to students in medicine and dentistry during anatomical dissection courses, but also to surgeons working in this field. PMID:26704358

  2. Atorvastatin Treatment for Carotid Intima-Media Thickness in Chinese Patients With Type 2 Diabetes: A Meta-Analysis.

    PubMed

    Fang, Na; Han, Wei; Gong, Dandan; Zou Chen; Fan, Yu

    2015-11-01

    Impact of atorvastatin on carotid intima-media thickness (CIMT) in patients with type 2 diabetes is still debating.The aim of our study is to investigate atorvastatin as adjuvant treatment on CIMT in Chinese patients with type 2 diabetes by conducting a meta-analysis based on the randomized controlled trials (RCTs).A systematic search of electronic database of the Pubmed, EMBASE, Cochrane Library, VIP database, China National Knowledge Infrastructure, and Wangfang up to January 2015 was conducted. Randomized controlled trials (RCTs) comparing atorvastatin adjuvant treatment to the hypoglycemic therapies or high-dose atorvastatin versus low-dose atorvastatin therapies for patients with type 2 diabetes were selected.A total of 14 RCTs involving 1345 patients were included. Adjuvant treatment with atorvastatin was associated with a significant reduction in CIMT (weighted mean difference [WMD] = -0.17 mm; 95% confidence interval [CI] -0.22 to -0.12). Compared with the low-dose atorvastatin, high-dose atorvastatin treatment was associated with a significant reduction in CIMT (WMD = -0.17 mm; 95% CI: -0.32 to -0.02). Adjuvant treatment with atorvastatin reduced serum total cholesterol, triglyceride, low-density lipoproteins, and high sensitivity C-reactive protein levels. However, atorvastatin had no significant impact on blood glucose levels.This meta-analysis demonstrated that treatment with atorvastatin significantly reduced CIMT in Chinese patients with type 2 diabetes. Moreover, high-dose atorvastatin appeared to have additional benefits in reducing CIMT than the low-dose atorvastatin. PMID:26554793

  3. The Combined Impact of Neutrophil-to-Lymphocyte Ratio and Type 2 Diabetic Mellitus on Significant Coronary Artery Disease and Carotid Artery Atherosclerosis

    PubMed Central

    Kim, Bong-Joon; Cho, Sang-Hoon; Kim, Hyun-Su; Heo, Jung-Ho; Cha, Tae-Joon

    2016-01-01

    Background Neutrophil-to-lymphocyte ratio (NLR) has recently emerged as a new important inflammatory marker for predicting cardiovascular events. This study aimed to evaluate the combined impact of NLR and type 2 diabetes mellitus (T2DM) on significant coronary artery disease (CAD) and carotid artery atherosclerosis. Methods This study includes a total of 828 patients evaluated by coronary angiography and carotid ultrasonography. Significant CAD was defined as at least one vessel with stenosis greater than 50%. We employed logistic regression models to investigate the association of NLR and T2DM with significant CAD. The goodness-of-fit and discriminability of the models were assessed by the loglikelihood ratio test and C-index, respectively. Also, we investigated the clinical relevance of the categorized NLR that classifies patients into three risk groups (low, intermediate, high). Results According to logistic regression analysis, both NLR {adjusted odds ratio (OR) 1.31, p < 0.001} and T2DM (adjusted OR 2.46, p = 0.006) were independent risk factors of significant CAD. The addition of NLR and T2DM into a logistic regression model including conventional cardiovascular risk factors significantly improved the goodness-of-fit (p < 0.001) and the discriminability of the model (p = 0.004). Also, T2DM patients assigned into the high risk group (NLR > 2) showed the greater prevalence of significant CAD and carotid artery atherosclerosis compared with patients without T2DM or type 2 diabetic patients assigned into the low risk group (NLR ≤ 1). Conclusion Our results suggest that type 2 diabetic patients with high inflammatory state would be more vulnerable to significant CAD and carotid artery atherosclerosis. PMID:27358703

  4. A novel approach to the treatment of a direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV.

    PubMed

    Nakagawa, Ichiro; Park, Hun Soo; Wada, Takeshi; Takayama, Katsutoshi; Nakagawa, Hiroyuki; Kichikawa, Kimihiko; Nakase, Hiroyuki

    2016-01-01

    We report a case of a direct carotid-cavernous fistula (CCF) in a patient with Ehlers-Danlos syndrome type IV who presented with progressive chemosis and diplopia. To prevent potential lethal arterial wall injury due to the fragility of the arterial vessel wall, the ipsilateral carotid artery and internal jugular vein were surgically exposed for direct insertion of endovascular sheaths, and transvenous embolization was performed using triple microcatheters with detachable coils. The clinical course was uneventful, and chemosis and diplopia subsequently resolved. By the 6 month follow-up, MRI revealed no recurrence of the CCF. These techniques offer a unique access alternative for endovascular treatment, thereby reducing the risks associated with arterial dissection that often accompanies transfemoral access in this particular condition. PMID:25432980

  5. Direct Carotid Cavernous Fistula of an Adult-Type Persistent Primitive Trigeminal Artery with Multiple Vascular Variations

    PubMed Central

    Jin, Sung-Chul; Park, Hyun; Choi, Choong-Gon

    2011-01-01

    We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF. PMID:21607181

  6. Direct carotid cavernous fistula of an adult-type persistent primitive trigeminal artery with multiple vascular variations.

    PubMed

    Jin, Sung-Chul; Park, Hyun; Kwon, Do Hoon; Choi, Choong-Gon

    2011-04-01

    We report a case of spontaneous right carotid-cavernous fistula (CCF) in a proximal segment of persistent primitive trigeminal artery (PPTA) and combined vascular anomalies such as left duplicated hypoplastic proximal posterior cerebral arteries and a variation of anterior choroidal artery supplying temporal and occipital lobe. A 45-year-old male presented with progressive right exophthalmos, diplopia, and ocular pain. With manual compression of the internal carotid artery, a cerebral angiography revealed a right CCF from a PPTA. Treatment involved the placement of detachable non-fibered and fibered coils, and use of a hyperglide balloon to protect against coil herniation into the internal carotid artery. A final angiograph revealed complete occlusion of PPTA resulted in no contrast filling of CCF. PMID:21607181

  7. A computer-graphic technique for the study of body size perception and body types.

    PubMed

    Benson, P J; Emery, J L; Cohen-Tovée, E M; Tovée, M J

    1999-08-01

    We present a novel approach for measuring body size estimation in normal and eating-disordered women and men. Clinical categories of body types were used as prototypes. By comparing the subjective appearance of a person's body with prototypes, we can understand how different attributes of his or her body shape contribute to perception of body size. After lifelike random distortions have been applied to parts of their body image, individuals adjust their body shapes until they converge on their perceived veridical appearance. Exaggeration and minimization of particular body areas measured with respect to their true shape and with different prototypes can be expressed as numerical deviations. In this way, perceived body size and body attractiveness can be appraised during the course of diagnosis and treatment of eating disorders. PMID:10502868

  8. Carotid Artery Disease

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Carotid Artery Disease? Carotid artery disease is a disease in ... blood to your face, scalp, and neck. Carotid Arteries Figure A shows the location of the right ...

  9. Distribution of transient receptor potential channels in the rat carotid chemosensory pathway.

    PubMed

    Buniel, Maria C F; Schilling, William P; Kunze, Diana L

    2003-09-22

    Glomus cells in the carotid body respond to decreases in oxygen tension of the blood and transmit this sensory information in the carotid sinus nerve to the brain via neurons in the petrosal ganglion. G-protein-coupled membrane receptors linked to phospholipase C may play an important role in this response through the activation of the cation channels formed by the transient receptor potential (TRP) proteins. In the present study, expression of TRPC proteins in the rat carotid body and petrosal ganglion was examined using immunohistochemical techniques. TRPC3, TRPC4, TRPC5, TRPC6, and TRPC7 were present in neurons throughout the ganglion. TRPC1 was expressed in only 28% of petrosal neurons, and of this population, 45% were tyrosine hydroxylase (TH)-positive, accounting for essentially all the TH-expressing neurons in the ganglion. Because TH-positive neurons project to the carotid body, this result suggests that TRPC1 is selectively associated with the chemosensory pathway. Confocal images through the carotid body showed that TRPC1/3/4/5/6 proteins localize to the carotid sinus nerve fibers, some of which were immunoreactive to an anti-neurofilament (NF) antibody cocktail. TRPC1 and TRPC3 were present in both NF-positive and NF-negative fibers, whereas TPRC4, TRPC5, and TRPC6 expression was primarily localized to NF-negative fibers. Only TRPC1 and TRPC4 were localized in the afferent nerve terminals that encircle individual glomus cells. TRPC7 was not expressed in sensory fibers. All the TRPC proteins studied were present in type I glomus cells. Although their role as receptor-activated cation channels in the chemosensory pathway is yet to be established, the presence of TRPC channels in glomus cells and sensory nerves of the carotid body suggests a role in facilitating and/or sustaining the hypoxic response. PMID:12900933

  10. Scandia-doped tungsten bodies for Sc-type cathodes

    NASA Astrophysics Data System (ADS)

    Wang, Jinshu; Wang, Yiman; Tao, Siwu; Li, Hongyi; Yang, Jiancan; Zhou, Meiling

    2003-06-01

    We systematically investigated scandium oxide-doped (and with small amount of rhenium-doped) tungsten bodies for Scandate-type cathodes. Homogeneous microstructure and uniform distribution of scandia were found in these bodies. Sub-micron granular porous bodies with greatly uniformly dispersed scandia are obtained by sintering Sc 2O 3 and Re doped tungsten powder. Such bodies are thought to be beneficial for emission uniformity. For Scandate-type cathodes with such bodies, a slight decrease of scandia was observed by "in situ" AES analysis after ion sputtering, but it recovers completely on reheating. It is assumed that film-like Sc 2O 3 coating over tungsten grains but leaving porous areas for diffusion of barium to the surface leads to good emission properties and high resistance to ion bombardment. Reprocucibility has been proved for the body manufactering process. This offers the possibility of improving the performance of these cathodes in applications such as CRT's.

  11. Spatial Distribution of Small Water Body Types across Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWB), such as ponds and wetlands, can have substantial cumulative effects on hydrologic, biogeochemical, and biological processes; yet the spatial distributions of various SWB types are often unknown. Usi...

  12. Anomalous course of the external carotid artery.

    PubMed

    Kawai, Katsushi

    2016-09-01

    The course and the branching patterns of the external carotid artery were investigated macroscopically in a total of 550 bodies or 1100 head sides of Japanese subjects, donated for student dissection at Kumamoto University from 1994 to 2014. With the exception of 14 head sides, the external carotid arteries running between the posterior belly of the digastric and stylohyoid muscles were found in 42 (3.87 %) out of 1086 head sides. Strictly speaking, they passed between the stylohyoid muscle and the stylohyoid branch of the facial nerve in 23 out of these 42 head sides. In the remaining 19 instances, the stylohyoid branch of the facial nerve was cut and its relationship to the external carotid artery was not clear. The external carotid artery running lateral to the intact stylohyoid branch of the facial nerve, medial to the digastric muscle was not found. The external carotid arteries running lateral to the digastric muscle were found in 4 (0.37 %) out of 1086 head sides. As a result, it is proposed that plural, potential courses of the external carotid artery originally exist and that some parts of such potential courses remain as branches of the external carotid artery in the usual instance, while the anomalous courses of the external carotid artery are induced mainly by anastomosis between the muscular branches supplying the wall of the head and neck in contrast to the usual external carotid artery induced mainly by the branches originally supplying the pharynx. PMID:26439732

  13. Gene Expression Profiling Supports the Neural Crest Origin of Adult Rodent Carotid Body Stem Cells and Identifies CD10 as a Marker for Mesectoderm-Committed Progenitors.

    PubMed

    Navarro-Guerrero, Elena; Platero-Luengo, Aida; Linares-Clemente, Pedro; Cases, Ildefonso; López-Barneo, José; Pardal, Ricardo

    2016-06-01

    Neural stem cells (NSCs) are promising tools for understanding nervous system plasticity and repair, but their use is hampered by the lack of markers suitable for their prospective isolation and characterization. The carotid body (CB) contains a population of peripheral NSCs, which support organ growth during acclimatization to hypoxia. We have set up CB neurosphere (NS) cultures enriched in differentiated neuronal (glomus) cells versus undifferentiated progenitors to investigate molecular hallmarks of cell classes within the CB stem cell (CBSC) niche. Microarray gene expression analysis in NS is compatible with CBSCs being neural crest derived-multipotent progenitor cells able to sustain CB growth upon exposure to hypoxia. Moreover, we have identified CD10 as a marker suitable for isolation of a population of CB mesectoderm-committed progenitor cells. CD10 + cells are resting in normoxia, and during hypoxia they are activated to proliferate and to eventually complete maturation into mesectodermal cells, thus participating in the angiogenesis necessary for CB growth. Our results shed light into the molecular and cellular mechanisms involved in CBSC fate choice, favoring a potential use of these cells for cell therapy. Stem Cells 2016;34:1637-1650. PMID:26866353

  14. Enhanced nitric oxide generation from nitric oxide synthases as the cause of increased peroxynitrite formation during acute restraint stress: Effects on carotid responsiveness to angiotensinergic stimuli in type-1 diabetic rats.

    PubMed

    Moreira, Josimar D; Pernomian, Larissa; Gomes, Mayara S; Moreira, Rafael P; do Prado, Alejandro F; da Silva, Carlos H T P; de Oliveira, Ana M

    2016-07-15

    Diabetes mellitus is associated with reactive oxygen and nitrogen species accumulation. Behavioral stress increases nitric oxide production, which may trigger a massive impact on vascular cells and accelerate cardiovascular complications under oxidative stress conditions such as Diabetes. For this study, type-1 Diabetes mellitus was induced in Wistar rats by intraperitoneal injection of streptozotocin. After 28 days, cumulative concentration-response curves for angiotensin II were obtained in endothelium-intact carotid rings from diabetic rats that underwent to acute restraint stress for 3h. The contractile response evoked by angiotensin II was increased in carotid arteries from diabetic rats. Acute restraint stress did not alter angiotensin II-induced contraction in carotid arteries from normoglycaemic rats. However acute stress combined with Diabetes increased angiotensin II-induced contraction in carotid rings. Western blot experiments and the inhibition of nitric oxide synthases in functional assays showed that neuronal, endothelial and inducible nitric oxide synthase isoforms contribute to the increased formation of peroxynitrite and contractile hyperreactivity to angiotensin II in carotid rings from stressed diabetic rats. In summary, these findings suggest that the increased superoxide anion generation in carotid arteries from diabetic rats associated to the increased local nitric oxide synthases expression and activity induced by acute restrain stress were responsible for exacerbating the local formation of peroxynitrite and the contraction induced by angiotensin II. PMID:27118175

  15. Carotid artery anatomy (image)

    MedlinePlus

    There are four carotid arteries, two on each side of the neck: right and left internal carotid arteries, and right and left external carotid arteries. The carotid arteries deliver oxygen-rich blood from the heart to the head and brain.

  16. Type-D personality and body image in men: the role of exercise status.

    PubMed

    Borkoles, Erika; Polman, Remco; Levy, Andrew

    2010-01-01

    The 'Distressed' or Type-D personality is described by the interaction between high levels of negative affectivity and social inhibition. This study investigated the prevalence of Type-D personality in men of different exercise status, the association between Type-D and body image perceptions, and the moderating effect of exercise status. Participants were 564 British males aged between 18 and 55 years. Of these 200 were classified as sedentary, 148 as active and 216 as weight trainers. Participants completed the DS14 and Multidimensional Body-Self Relations Questionnaire. Results showed that more individuals were classified as Type-D in the sedentary group (45%) than the two active groups, and in the weight training (24.5%) than the active (14.2%) group. Both Type-D and a sedentary lifestyle were associated with a significantly poorer body image. However, exercise mode was not associated with body image differences. Sedentary Type-D men scored significantly lower in Body Areas Satisfaction and higher in Self-Classified Weight than both active groups. Regular exercise might provide a pathway for Type-D men to develop a more positive body image. PMID:19945926

  17. 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

  18. 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.

  19. Inhibition of [3H]catecholamine release and Ca2+ currents by prostaglandin E2 in rabbit carotid body chemoreceptor cells.

    PubMed Central

    Gómez-Niño, A; López-López, J R; Almaraz, L; González, C

    1994-01-01

    Basal release of [3H]catecholamine ([3H]CA) from rabbit carotid bodies (CBs), previously incubated in the presence of [3H]tyrosine, was not significantly modified by prostaglandin E2 (PGE2). On the contrary, PGE2 (3-300 nM) produced a dose-dependent inhibition of the low PO2-evoked release of [3H]CA. The inhibition was greatest (55%) at a low intensity of hypoxic stimulation (incubating solution PO2 approximately 66 mmHg) and decreased with increasing intensities of hypoxia. Chronic denervation of the CB did not modify the response to PGE2. The release of [3H]CA induced by incubating the CBs in a hypercapnic-acidic solution (PCO2 approximately 132 mmHg; pH = 6.60) and by dinitrophenol (100 microM) was not significantly modified by 300 nM PGE2. PGE2 (300 nM) inhibited the release of [3H]CA elicited by incubating the CBs in a high K+ (35 mM)-containing solution. The release response elicited by high K+ (25 mM) was strongly augmented by a dihydropyridine agonist of Ca2+ channels, Bay K 8644, at a concentration of 1 microM. The Bay K 8644 effect was partly inhibited by PGE2 (300 nM). Using whole-cell recordings in freshly dispersed or short-term cultured chemoreceptor cells from adult rabbits it was found that Ca2+ currents (ICa) were reversibly inhibited by bath application of PGE2. A good parallelism exits between the dose-response curves for PGE2 inhibition of ICa in isolated chemoreceptor cells and high extracellular [K+]- or hypoxia-evoked release of [3H]CA from the whole CB.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7519263

  20. Increase in cytosolic Ca2+ produced by hypoxia and other depolarizing stimuli activates a non-selective cation channel in chemoreceptor cells of rat carotid body

    PubMed Central

    Kang, Dawon; Wang, Jiaju; Hogan, James O; Vennekens, Rudi; Freichel, Marc; White, Carl; Kim, Donghee

    2014-01-01

    The current model of O2 sensing by carotid body chemoreceptor (glomus) cells is that hypoxia inhibits the outward K+ current and causes cell depolarization, Ca2+ influx via voltage-dependent Ca2+ channels and a rise in intracellular [Ca2+] ([Ca2+]i). Here we show that hypoxia (<5% O2), in addition to inhibiting the two-pore domain K+ channels TASK-1/3 (TASK), indirectly activates an ∼20 pS channel in isolated glomus cells. The 20 pS channel was permeable to K+, Na+ and Cs+ but not to Cl− or Ca2+. The 20 pS channel was not sensitive to voltage. Inhibition of TASK by external acid, depolarization of glomus cells with high external KCl (20 mm) or opening of the Ca2+ channel with FPL64176 activated the 20 pS channel when 1 mm Ca2+ was present in the external solution. Ca2+ (10 μm) applied to the cytosolic side of inside-out patches activated the 20 pS channel. The threshold [Ca2+]i for activation of the 20 pS channel in cell-attached patches was ∼200 nm. The reversal potential of the 20 pS channel was estimated to be −28 mV. Our results reveal a sequential mechanism in which hypoxia (<5% O2) first inhibits the K+ conductance and then activates a Na+-permeable, non-selective cation channel via depolarization-induced rise in [Ca2+]i. Our results suggest that inhibition of K+ efflux and stimulation of Na+ influx both contribute to the depolarization of glomus cells during moderate to severe hypoxia. PMID:24591572

  1. Solvable Many-Body Models of Goldfish Type with One-, Two- and Three-Body Forces

    NASA Astrophysics Data System (ADS)

    Bihun, Oksana; Calogero, Francesco

    2013-10-01

    The class of solvable many-body problems ''of goldfish type'' is extended by including (the additional presence of) three-body forces. The solvable N-body problems thereby identified are characterized by Newtonian equations of motion featuring 19 arbitrary ''coupling constants''. Restrictions on these constants are identified which cause these systems - or appropriate variants of them - to be isochronous or asymptotically isochronous, i.e. all their solutions to be periodic with a fixed period (independent of the initial data) or to have this property up to contributions vanishing exponentially as t→ ∞.

  2. Effects of biphasic, basal-bolus or basal insulin analogue treatments on carotid intima-media thickness in patients with type 2 diabetes mellitus: the randomised Copenhagen Insulin and Metformin Therapy (CIMT) trial

    PubMed Central

    Lundby-Christensen, Louise; Vaag, Allan; Tarnow, Lise; Almdal, Thomas P; Lund, Søren S; Wetterslev, Jørn; Gluud, Christian; Boesgaard, Trine W; Wiinberg, Niels; Perrild, Hans; Krarup, Thure; Snorgaard, Ole; Gade-Rasmussen, Birthe; Thorsteinsson, Birger; Røder, Michael; Mathiesen, Elisabeth R; Jensen, Tonny; Vestergaard, Henrik; Hedetoft, Christoffer; Breum, Leif; Duun, Elsebeth; Sneppen, Simone B; Pedersen, Oluf; Hemmingsen, Bianca; Carstensen, Bendix; Madsbad, Sten

    2016-01-01

    Objective To assess the effect of 3 insulin analogue regimens on change in carotid intima-media thickness (IMT) in patients with type 2 diabetes. Design and setting Investigator-initiated, randomised, placebo-controlled trial with a 2×3 factorial design, conducted at 8 hospitals in Denmark. Participants and interventions Participants with type 2 diabetes (glycated haemoglobin (HbA1c)≥7.5% (≥58 mmol/mol), body mass index >25 kg/m2) were, in addition to metformin versus placebo, randomised to 18 months open-label biphasic insulin aspart 1–3 times daily (n=137) versus insulin aspart 3 times daily in combination with insulin detemir once daily (n=138) versus insulin detemir alone once daily (n=137), aiming at HbA1c≤7.0% (≤53 mmol/mol). Outcomes Primary outcome was change in mean carotid IMT (a marker of subclinical cardiovascular disease). HbA1c, insulin dose, weight, and hypoglycaemic and serious adverse events were other prespecified outcomes. Results Carotid IMT change did not differ between groups (biphasic −0.009 mm (95% CI −0.022 to 0.004), aspart+detemir 0.000 mm (95% CI −0.013 to 0.013), detemir −0.012 mm (95% CI −0.025 to 0.000)). HbA1c was more reduced with biphasic (−1.0% (95% CI −1.2 to −0.8)) compared with the aspart+detemir (−0.4% (95% CI −0.6 to −0.3)) and detemir (−0.3% (95% CI −0.4 to −0.1)) groups (p<0.001). Weight gain was higher in the biphasic (3.3 kg (95% CI 2.7 to 4.0) and aspart+detemir (3.2 kg (95% CI 2.6 to 3.9)) compared with the detemir group (1.9 kg (95% CI 1.3 to 2.6)). Insulin dose was higher with detemir (1.6 IU/kg/day (95% CI 1.4 to 1.8)) compared with biphasic (1.0 IU/kg/day (95% CI 0.9 to 1.1)) and aspart+detemir (1.1 IU/kg/day (95% CI 1.0 to 1.3)) (p<0.001). Number of participants with severe hypoglycaemia and serious adverse events did not differ. Conclusions Carotid IMT change did not differ between 3 insulin regimens despite differences in HbA1c, weight gain and

  3. 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 ...

  4. Carotid artery disease

    MedlinePlus

    ... you have had a stroke or TIA, a nervous system (neurological) exam will show other problems. You may also have the following tests: Blood cholesterol and triglycerides test Blood sugar (glucose) test Ultrasound of the carotid arteries ( carotid ...

  5. Carotid artery surgery - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000238.htm Carotid artery surgery - discharge To use the sharing features on this page, please enable JavaScript. You had carotid artery surgery to restore proper blood flow to your ...

  6. Carotid artery surgery - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100124.htm Carotid artery surgery - series To use the sharing features on ... 4 Normal anatomy Overview There are four carotid arteries, with a pair located on each side of ...

  7. Carotid endarterectomy or stenting?

    PubMed Central

    Ng, P Y

    2009-01-01

    The relative role of surgical or endovascular treatment in carotid stenosis remains controversial. Results of recent studies add even more confusion to the debate. Major clinical trials so far have shown a wide range of complication rates for carotid endarterectomy and carotid stenting. Only surgeons or interventionists who can maintain a complication rate of 3% or below should consider treating patients with asymptomatic disease.

  8. Carotid sinus syndrome.

    PubMed

    Mallet, Mark

    2003-02-01

    This article reviews the recent literature about carotid sinus syndrome. It looks principally at the various ways in which it may present, the limited knowledge of its pathophysiology, and the role of carotid sinus massage in the investigation of carotid sinus syndrome. PMID:12619336

  9. Molecular identification of Kvα subunits that contribute to the oxygen-sensitive K+ current of chemoreceptor cells of the rabbit carotid body

    PubMed Central

    Sanchez, Diego; López-López, Jose R; Pérez-García, M Teresa; Sanz-Alfayate, Gloria; Obeso, Ana; Ganfornina, Maria D; Gonzalez, Constancio

    2002-01-01

    Rabbit carotid body (CB) chemoreceptor cells possess a fast-inactivating K+ current that is specifically inhibited by hypoxia. We have studied the expression of Kvα subunits, which might be responsible for this current. RT-PCR experiments identified the expression of Kv1.4, Kv3.4, Kv4.1 and Kv4.3 mRNAs in the rabbit CB. There was no expression of Kv3.3 or Kv4.2 transcripts. Immunocytochemistry with antibodies to tyrosine hydroxylase (anti-TH) and to specific Kv subunits revealed the expression of Kv3.4 and Kv4.3 in chemoreceptor cells, while Kv1.4 was only found in nerve fibres. Kv4.1 mRNA was also found in chemoreceptor cells following in situ hybridization combined with anti-TH antibody labelling. Kv4.1 and Kv4.3 appeared to be present in all chemoreceptor cells, but Kv3.4 was only expressed in a population of them. Electrophysiological experiments applying specific toxins or antibodies demonstrated that both Kv3.4 and Kv4.3 participate in the oxygen-sensitive K+ current of chemoreceptor cells. However, toxin application experiments confirmed a larger contribution of members of the Kv4 subfamily. [Ca2+]i measurements under hypoxic conditions and immunocytochemistry experiments in dispersed CB cells demonstrated the expression of Kv3.4 and Kv4.3 in oxygen-sensitive cells; the presence of Kv3.4 in the chemoreceptor cell membrane was not required for the response to low PO2. In summary, three Kv subunits (Kv3.4, Kv4.1 and Kv4.3) may be involved in the fast-inactivating outward K+ current of rabbit CB chemoreceptor cells. The homogeneous distribution of the Kv4 subunits in chemoreceptor cells, along with their electrophysiological properties, suggest that Kv4.1, Kv4.3, or their heteromultimers, are the molecular correlate of the oxygen-sensitive K+ channel. PMID:12122138

  10. Association of Risk Estimates of Three Different Cardiovascular Risk Assessment Tools with Carotid Intima Media Thickness in Patients with Type 2 Diabetes

    PubMed Central

    Weerarathna, Thilak Priyantha; Dulanjalee, Ranasinghe Bethmi Arachige Thilini; Jayawardana, Madumekala Rupasinghe; Edirisingha, Udara Priyadarshani; Rathnayake, Madushanka

    2016-01-01

    Introduction Risk assessment tools used to calculate the Cardiovascular Disease (CVD) risk such as the Framingham Risk Score (FRS), United Kingdom Prospective Diabetes study (UKPDS) risk engine and the World Health Organization (WHO) risk score have not been tested on their ability to detect subclinical atherosclerosis in most developing countries. Aim To study the association between the calculated CVD risk scores using each of these tools and Carotid Intima Medial Thickness (CIMT), a surrogate marker of atherosclerosis, in a group of patients with Type 2 diabetes (T2DM) in Sri Lanka. Materials and Methods We calculated CVD risk scores of 68 randomly selected patients with T2DM with no history or symptoms of CVD and measured their CIMT using B-mode ultrasonography (USS). Carotid USS was considered positive when the maximum carotid IMT was 0.9mm or when arteriosclerotic plaques were detected. The 10-year CVD risk was calculated using the FRS, the UKPDS risk engine and the WHO risk score. Pearson correlation was used to study the association between CVD risk scores with CIMT. Results Of the 68 patients studied, 50% were males and their mean age (SD) was 56.9 (±9.6) years. The mean age at onset and duration of diabetes were 44.3(±9.1) and 12.2(±7.6) years respectively. Of the scoring methods, UKPDS tool had weak, but significantly positive (r = 0.26, p < 0.05) and FRS had positive but not significant association (r= 0. 21) with CIMT. There was a negative association between CIMT and WHO risk score (r= - 0.07). Conclusion Of the three CVD risk assessment tools, both UKPDS risk engine and FRS have almost equal ability (former being marginally superior) in predicting underlying atherosclerotic vascular disease in patients with T2DM. Negative association of the WHO risk score with CIMT argues against its utility for CVD screening. These findings highlight the need for developing more sensitive and reliable CVD risk assessment tools for developing countries.

  11. Experimental aerodynamic study of a car-type bluff body

    NASA Astrophysics Data System (ADS)

    Conan, Boris; Anthoine, Jérôme; Planquart, Philippe

    2011-05-01

    The Ahmed body is used as a reference model for fundamental studies of car-type bluff body aerodynamics, in particular focused on the influence of the rear slant angle on the drag coefficient. The objectives of the present work are to obtain reliable drag coefficient comparable to the literature and to explain, based on the nature of the flow, its variation when changing the rear slant angle from 10° to 40°. The drag coefficients measured in both an open and a closed test sections differ by less than 0.5% which proves the reliability and reproducibility of the results. The sensitivity of the drag coefficient to some parameters such as the model roughness or the oncoming boundary layer and the lack of precise information on these parameters in the literature could explain the difference observed with the Ahmed drag coefficient data. The various types of measurement techniques used in the study underline their complementarity. The combination of particle image velocimetry and oil visualization provides a deeper understanding of the flow behaviour around the Ahmed body and a physical interpretation of the drag coefficient evolution.

  12. Data on carotid intima-media thickness and lipoprotein subclasses in type 1 diabetes from the Diabetes Control and Complications Trial and the Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC)

    PubMed Central

    Basu, Arpita; Jenkins, Alicia J.; Zhang, Ying; Stoner, Julie A.; Klein, Richard L.; Lopes-Virella, Maria F.; Timothy Garvey, W.; Lyons, Timothy J.

    2015-01-01

    Type 1 diabetes (T1DM) is associated with increased risk of macrovascular complications. We examined longitudinal associations of serum conventional lipids and nuclear magnetic resonance (NMR)-determined lipoprotein subclasses with carotid intima-media thickness (IMT) in adults with T1DM (n=455) enrolled in the Diabetes Control and Complications Trial (DCCT). Data on serum lipids and lipoproteins were collected at DCCT baseline (1983–89) and were correlated with common and internal carotid IMT determined by ultrasonography during the observational follow-up of the DCCT, the Epidemiology of Diabetes Interventions and Complications (EDIC) study, at EDIC ‘Year 1’ (199–1996) and EDIC ‘Year 6’ (1998–2000). This article contains data on the associations of DCCT baseline lipoprotein profiles (NMR-based VLDL & chylomicrons, IDL/LDL and HDL subclasses and ‘conventional’ total, LDL-, HDL-, non-HDL-cholesterol and triglycerides) with carotid IMT at EDIC Years 1 and 6, stratified by gender. The data are supplemental to our original research article describing detailed associations of DCCT baseline lipids and lipoprotein profiles with EDIC Year 12 carotid IMT (Basu et al. in press) [1]. PMID:26759826

  13. In vitro activation of cyclo-oxygenase in the rabbit carotid body: effect of its blockade on [3H]catecholamine release.

    PubMed Central

    Gómez-Niño, A; Almaraz, L; González, C

    1994-01-01

    The release of prostaglandin E2 (PGE2) from rabbit carotid bodies (CBs) incubated in basal conditions (PO2 approximately 132 mmHg; PCO2 approximately 33 mmHg; pH = 7.42) amounts to 94.4 +/- 10.1 pg (mg protein)-1 (10 min)-1 (mean +/- S.E.M.). Incubation of the CB in a hypoxic solution (PO2 approximately 46 mmHg) produced a significant 40% increase (P < 0.05) in the release of PGE2. Indomethacin (2 microM) prevented the hypoxia-induced release of PGE2. Sensory plus sympathetic denervation of the CB 4 days prior to the experiments did not modify either basal or low PO2-induced PGE2 release, indicating that intraglomic nerve endings are not significant sources for the PGE2 released. Incubation of the CB in an acidic-hypercapnic solution (PO2 approximately 132 mmHg; PCO2 approximately 132 mmHg; pH = 6.60) or in a high K(+)-containing solution (35 mM) was also effective in promoting an increase in the outflow of PGE2 from the organs. The release of [3H]catecholamines ([3H]CA) from the CB elicited by incubating the organs in low PO2 solutions (PO2 ranged between 66 and 13 mmHg) was potentiated by two inhibitors of cyclo-oxygenase, acetylsalicylic acid (ASA, 100 microM) and indomethacin (2 microM). The effect persisted after chronic denervation of the organ. The secretory response elicited by acidic stimuli was also augmented by cyclo-oxygenase inhibitors. Thus, [3H]CA release elicited by incubating the CBs in the acidic-hypercapnic solution increased by 300% in the presence of indomethacin (2 microM), and ASA (100 microM) more than doubled the release induced by dinitrophenol (100 microM), a protonophore that mimics an acidic stimulus. Indomethacin, but not ASA, moderately increased the high K(+)-evoked [3H]CA release. The effect of indomethacin on the release of [3H]CA elicited by acidic and hypoxic stimuli was reversed by PGE2 in a dose-dependent manner (0.3-300 nM). These results show that low PO2 and high PCO2-low pH, the natural stimuli to the CB, as well as high

  14. Another New Solvable Many-Body Model of Goldfish Type

    NASA Astrophysics Data System (ADS)

    Calogero, Francesco

    2012-07-01

    A new solvable many-body problem is identified. It is characterized by nonlinear Newtonian equations of motion (''acceleration equal force'') featuring one-body and two-body velocity-dependent forces ''of goldfish type'' which determine the motion of an arbitrary number N of unit-mass point-particles in a plane. The N (generally complex) values z_{n}( t) at time t of the N coordinates of these moving particles are given by the N eigenvalues of a time-dependent N× N matrix U( t) explicitly known in terms of the 2N initial data z_{n}( 0) and dot{z}_{n}(0) . This model comes in two different variants, one featuring 3 arbitrary coupling constants, the other only 2; for special values of these parameters all solutions are completely periodic with the same period independent of the initial data (''isochrony''); for other special values of these parameters this property holds up to corrections vanishing exponentially as t→ ∞ (''asymptotic isochrony''). Other isochronous variants of these models are also reported. Alternative formulations, obtained by changing the dependent variables from the N zeros of a monic polynomial of degree N to its N coefficients, are also exhibited. Some mathematical findings implied by some of these results - such as Diophantine properties of the zeros of certain polynomials - are outlined, but their analysis is postponed to a separate paper.

  15. Living with Carotid Artery Disease

    MedlinePlus

    ... from the NHLBI on Twitter. Living With Carotid Artery Disease If you have carotid artery disease, you can take steps to manage the ... treatment plan, and getting ongoing care. Having carotid artery disease raises your risk of having a stroke . ...

  16. [Carotid atherosclerosis and dementia].

    PubMed

    Harlé, Louise-Marine; Plichart, Matthieu

    2015-09-01

    Over the past decade a growing interest has been devoted to exploring the role of atherosclerosis in the development of dementia. Despite a well-known association between atherosclerosis risk factors in middle-life with later cognitive decline, the pathophysiological pathways underlying this association remain unclear. The current hypothesis is that neurodegenerative and vascular lesions coexist and have a synergistic role in the development of cognitive impairment and dementia. Carotid atherosclerosis (e.g. carotid plaques and intima-media thickness as measured by carotid ultrasonography) has been associated with cognitive decline and dementia and may help to better understand the complex interaction between the vascular and neurodegenerative processes. Furthermore, carotid atherosclerosis has been used in the recent field for dementia risk prediction. In this review, we discuss the physiopathological implications from the current available data on the relationship between carotid atherosclerosis and dementia as well as the interest of carotid biomarkers for individual dementia risk prediction. PMID:26395304

  17. Body type and performance of elite cuban baseball players.

    PubMed

    Carvajal, Wiliam; Ríos, Andrés; Echevarría, Ivis; Martínez, Miriam; Miñoso, Julio; Rodríguez, Dialvis

    2009-04-01

    Introduction Appropriate stature and adequate somatotype are not the only attributes determining athletic performance, but they are important prerequisites for sports participation and success. However, there is scant literature on baseball players' kinanthropometric profiles and their association with performance. Given that Cuban baseball players have been among the world's top performers in recent decades, characterization of their morphological features linked to their performance may contribute to developing the evidence base in this area. Objective Describe the kinanthropometric profile related to sports performance of elite Cuban baseball players, classified by playing position. Methods Body composition, somatotype, proportionality, and performance were measured in 100 elite baseball players grouped by playing position and performance. Data from the 2002-2003 baseball season was gathered for players participating in the 43rd Cuban National Baseball Series (November 2003-May 2004). Slugging percentage (SLG) was used to measure performance of all players except pitchers, whose performance was measured as end-of-season win-loss record. Mean and standard deviation values were calculated for anthropometric and performance results, presented in tables for comparison. ANOVA and MANOVA analyses were applied to determine magnitudes of difference between the variables studied, as well as statistical significance of the differences established (p≤0.05 and p≤0.01). Results Performance and body type varied by playing position, and statistically significant differences were found in performance, body composition and somatotype variables between some positions. No significant differences in proportionality were found. First basemen and outfielders (center, left, and right fielders) were the best offensive players with the highest mean SLG, body weight and muscle mass values. Infielders (second basemen, shortstops, and third basemen) had the lowest mean body weight and

  18. Altered body composition in type 2 diabetes mellitus

    PubMed Central

    Heshka, Stanley; Ruggiero, Andrea; Bray, George A.; Foreyt, John; Kahn, Stephen E.; Lewis, Cora E.; Saad, Mohammed; Schwartz, Ann V.

    2010-01-01

    Objective To identify differences in amount and distribution of fat and lean soft tissue in subjects with and without type 2 diabetes and to determine whether any differences are affected by race/ethnicity or sex. Design Overweight and obese (body mass index, BMI≥25 kg/m2) Black, White and Hispanic men (490) and women (825) with type 2 diabetes ([mean±SD] age 58.5±6.6; BMI 35.3±5.3) who had a baseline dual energy x-ray absorptiometry whole body scan at the time of enrollment in the Look Ahead clinical trial, and 242 healthy controls, 91 males and 151 females (age 55.3±8.6 y, BMI 30.7±4.2 kg/m2) who were participating in unrelated research and were scanned on the same densitometers. Results Adjusted for covariates, total fat mass was smaller in persons with type 2 diabetes than in controls (−1.4±0.3[SE]; 34.5 vs 35.8 kg, p<0.001) while trunk fat was larger (1.3±0.2[SE]; 19.9 vs 18.6 kg, p<0.001) and leg fat was smaller (−1.5±0.2[SE]; 10.7 vs 12.3 kg, p<0.001). The arms of subjects with type 2 diabetes did not have significantly less fat compared to controls. Adjusted trunk lean mass was larger in type 2 diabetes by 0.6 kg (28.4 vs 27.8 kg, p<0.001) while leg lean was smaller by 0.5 kg (18.1 vs 18.6 kg, p<0.001). Conclusions Type 2 diabetes is associated with less total fat, leg fat and leg lean mass and more truncal fat and lean mass than controls. The physiological processes producing these deviations in tissue distribution and their metabolic significance warrant further investigation. (ClinicalTrials.gov number, NCT00017953) PMID:18227843

  19. Serum carboxy-terminal telopeptide of type I collagen levels are associated with carotid atherosclerosis in patients with cardiovascular risk factors.

    PubMed

    Kondo, Takeshi; Endo, Itsuro; Aihara, Ken-Ichi; Onishi, Yukiyo; Dong, Bingzi; Ohguro, Yukari; Kurahashi, Kiyoe; Yoshida, Sumiko; Fujinaka, Yuichi; Kuroda, Akio; Matsuhisa, Munehide; Fukumoto, Seiji; Matsumoto, Toshio; Abe, Masahiro

    2016-04-25

    Carboxy-terminal telopeptide of type I collagen (ICTP) is generated through matrix metalloproteinase (MMP)-dependent type I collagen digestion, and has been widely utilized as a biomarker for bone turnover. The fact that atherosclerotic lesions are rich in both type I collagen and MMP-producing macrophages led to the hypothesis that serum ICTP concentrations may serve as a non-invasive clinical biomarker for atherosclerosis. Therefore, the association of serum ICTP concentrations with the maximum intima-media thickness (IMT) of carotid arteries, a surrogate index of systemic atherosclerosis, or brachial-ankle pulse wave velocity (baPWV) in patients with atherosclerotic risk factors was evaluated. A total of 52 male and 65 female (mean age: 62.8 yrs) patients without renal failure, malignancies or bone diseases known to affect serum ICTP concentrations were recruited. Patients with max IMTs ≥1.1 mm showed significantly higher serum ICTP concentrations compared with patients with max IMTs <1.1 mm (3.33 ± 0.97 vs 2.82 ± 0.65 ng/mL, p<0.05). Serum ICTP concentration was also positively correlated with max IMT (p<0.001) or baPWV values (p<0.05). Multivariate analyses also revealed that serum ICTP concentrations were correlated with max IMT (p<0.001; 95% CI 0.200 to 0.454). These results suggest that serum ICTP concentrations can be used as a non-invasive biomarker for systemic atherosclerosis. PMID:26877258

  20. Carotid Artery Disease

    MedlinePlus

    ... small balloon on its tip. They inflate the balloon at the blockage site in the carotid artery to flatten or compress the plaque against the artery wall. Carotid angioplasty is often combined with the placement of a small, metal, mesh-like device called a stent. When a stent is placed inside of a ...

  1. Body Type and Sex of Receiver: Their Effects on Source Credibility.

    ERIC Educational Resources Information Center

    Eckman, Bruce K.; Rancer, Andrew S.

    This study focused on whether actual or stereotypic associations with a speaker's body type would affect his or her credibility. Effects on the source-credibility ratings submitted by a total of 165 students were investigated for three different sources' body types. A significant main effect was found for body type but not for the blocked…

  2. 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.

  3. 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.

  4. Relationship between Carotid Intima-Media Thickness and Left Ventricular Mass in Type 1 Diabetes: results from the Epidemiology of Diabetes Interventions and Complications (EDIC) Study

    PubMed Central

    Chahal, Harjit; Backlund, Jye-Yu C.; Cleary, Patricia A.; Lachin, John M.; Polak, Joseph; Lima, Joao A.C.; Bluemke, David A.

    2012-01-01

    Introduction Type 1 diabetes mellitus is associated with early atherosclerosis and enhanced cardiovascular mortality. The relationship between carotid IMT (cIMT), a marker of subclinical atherosclerosis and left ventricular (LV) mass, an independent predictor of cardiovascular morbidity has not been previously studied in type 1 diabetics. Methods The Epidemiology of Diabetes Interventions and Complications (EDIC) study is a multicenter observational study designed to follow up the Diabetes Control and Complications Trial (DCCT) cohort. LV mass was measured with cardiac MRI at EDIC year 15 and common cIMT was assessed using B-mode ultrasound at EDIC year 12. Multivariable linear regression models were used to assess the relationship between cIMT at year 12 and LV mass at year 15. Results A total of 889 participants had both cardiac MRI and cIMT measures available for these analyses. At EDIC year 15, the mean age of the participants was 49 (±7) years; mean diabetes duration was 28 (±5) years and 52% were males. Spearman correlation coefficient (r) between LV mass and cIMT was 0.33 (p<0.0001). After adjusting for basic covariates (machine, reader, age and gender), a significant association between LV mass and cIMT (estimate 2.0 g/m2 per 0.1 mm cIMT increment, p < 0.0001) was observed. This association was diminished by the addition of systolic blood pressure in particular 1.15 g/m2 per 0.1 mm cIMT increment, p<0.0001) and to a lessor extent other cardiovascular disease (CVD) risk factors. The relationship observed between LV mass and cIMT was stronger (HOW MUCH) in patients with shorter diabetes duration. Conclusion In a well characterized population with type 1 diabetes, cIMT was an independent predictor of higher LV mass. These findings suggest a common pathway, possibly mediated by blood pressure dependent mechanisms, for vascular and myocardial structural change in T1DM. PMID:22884107

  5. Carotid artery surgery

    MedlinePlus

    ... Aspirin and heart disease Butter, margarine, and cooking oils Carotid artery surgery - discharge Cholesterol and ... by: Daniel Kantor, MD, Kantor Neurology, Coconut Creek, FL and Immediate Past President of the ...

  6. 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 in your groin after using some ...

  7. [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

  8. Spatial Distribution of Small Water Body Types in Indiana Ecoregions

    EPA Science Inventory

    Due to their large numbers and biogeochemical activity, small water bodies (SWBs), such as ponds and wetlands, can have substantial cumulative effects on hydrologic and biogeochemical processes. Using updated National Wetland Inventory data, we describe the spatial distribution o...

  9. Post Tracheostomy Carotid-Tracheal Fistula.

    PubMed

    Shylendran, Sudhin; Baliyan, Vinit; Yadav, Ajay K; Kumar, Atin; Gamanagatti, Shivanand

    2016-03-01

    Tracheostomy is the life saving procedure in patients presenting with upper airway obstruction. The procedure is also performed in patients on chronic ventilatory support. It is generally considered a safe procedure with a low complication rate. Vascular injuries are the most serious and life threatening complications. Injury to a high lying innominate artery is the most frequent vascular injury in such cases. Injury to other vessels e.g. carotid arteries is less frequent. We are presenting one such rare type of vascular injury with a fistulous communication between trachea and carotid artery leading to massive hemoptysis. PMID:27066421

  10. Extramedullary plasmacytoma in the carotid space: Expanding the differential diagnosis

    PubMed Central

    Deshpande, Sneha Satish; Kane, Shubhada; Arya, Supreeta

    2014-01-01

    Plasma cell neoplasms have been classified into various types, with a range of clinical and radiological presentations. Extramedullary plasmacytoma (EMP) is a subset of plasma cell neoplasms which presents as an isolated non-osseous soft tissue mass. Though carotid space neoplasms are commonly encountered, EMP in the carotid space is rare and seldom considered in the initial differential diagnosis of a carotid space mass. These tumors can be treated by surgery or radiotherapy. On the other hand, the commonly encountered tumors in the carotid space are treated surgically. Also, it is mandatory to exclude multiple myeloma in the patients presenting with EMP. Hence, accurate and early diagnosis has therapeutic and prognostic implications. We report a rare case of EMP of the carotid space, describing the imaging features and the differential diagnoses with clues pointing to this rare entity. PMID:25489135

  11. 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 ...

  12. Basilar vascular system supplied by only right proatlantal intersegmentary artery type 1 with aneurysm and left internal carotid occlusion: a case report and review from the literature.

    PubMed

    Ferrone, Alessandro; Brogna, Barbara; Giliberti, Raffaele; Vassallo, Pasquale; De Magistris, Giuseppe

    2016-09-01

    Persistence of proatlantal artery (PA) is a rare condition. More than 40 cases were described in the literature. Aneurysm may involve the PA itself in approximately 2% of cases, most arising from the internal carotid artery (ICA) side of PA. This case was particular because the PA showed a saccular aneurysm on the posterior wall, probably due to atherosclerosis disease and other alterations: plaque ulcerative of ICA, occlusion of left ICA, and aberrant right VA. PMID:27594943

  13. 16 CFR 1112.11 - What are the types of third party conformity assessment bodies?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... assessment bodies? 1112.11 Section 1112.11 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS REQUIREMENTS PERTAINING TO THIRD PARTY CONFORMITY ASSESSMENT BODIES General Requirements Pertaining to Third Party Conformity Assessment Bodies § 1112.11 What are the types of third...

  14. Perceived Fashionability of a Garment as Inferred from the Age and Body Type of the Wearer.

    ERIC Educational Resources Information Center

    Clayton, Ruth; And Others

    1987-01-01

    Ninety college-aged females rated the fashionability of six garments worn by nine models representing three age levels and three body types. Results show respondents used age and body type cues as well as fashion detail to judge garment fashionability. (Author/CH)

  15. 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

  16. Common Carotid Intima Media Thickness and Ankle-Brachial Pressure Index Correlate with Local but Not Global Atheroma Burden: A Cross Sectional Study Using Whole Body Magnetic Resonance Angiography

    PubMed Central

    Weir-McCall, Jonathan R.; Khan, Faisel; Lambert, Matthew A.; Adamson, Carly L.; Gardner, Michael; Gandy, Stephen J.; Ramkumar, Prasad Guntur; Belch, Jill J. F.; Struthers, Allan D.; Rauchhaus, Petra; Morris, Andrew D.; Houston, J. Graeme

    2014-01-01

    Background Common carotid intima media thickness (CIMT) and ankle brachial pressure index (ABPI) are used as surrogate marker of atherosclerosis, and have been shown to correlate with arterial stiffness, however their correlation with global atherosclerotic burden has not been previously assessed. We compare CIMT and ABPI with atheroma burden as measured by whole body magnetic resonance angiography (WB-MRA). Methods 50 patients with symptomatic peripheral arterial disease were recruited. CIMT was measured using ultrasound while rest and exercise ABPI were performed. WB-MRA was performed in a 1.5T MRI scanner using 4 volume acquisitions with a divided dose of intravenous gadolinium gadoterate meglumine (Dotarem, Guerbet, FR). The WB-MRA data was divided into 31 anatomical arterial segments with each scored according to degree of luminal narrowing: 0 = normal, 1 = <50%, 2 = 50–70%, 3 = 70–99%, 4 = vessel occlusion. The segment scores were summed and from this a standardized atheroma score was calculated. Results The atherosclerotic burden was high with a standardised atheroma score of 39.5±11. Common CIMT showed a positive correlation with the whole body atheroma score (β 0.32, p = 0.045), however this was due to its strong correlation with the neck and thoracic segments (β 0.42 p = 0.01) with no correlation with the rest of the body. ABPI correlated with the whole body atheroma score (β −0.39, p = 0.012), which was due to a strong correlation with the ilio-femoral vessels with no correlation with the thoracic or neck vessels. On multiple linear regression, no correlation between CIMT and global atheroma burden was present (β 0.13 p = 0.45), while the correlation between ABPI and atheroma burden persisted (β −0.45 p = 0.005). Conclusion ABPI but not CIMT correlates with global atheroma burden as measured by whole body contrast enhanced magnetic resonance angiography in a population with symptomatic peripheral

  17. Aerodynamics on a transport aircraft type wing-body model

    NASA Technical Reports Server (NTRS)

    Schmitt, V.

    1982-01-01

    The DFLR-F4 wing-body combination is studied. The 1/38 model is formed by a 9.5 aspect ratio transonic wing and an Airbus A 310 fuselage. The F4 wing geometrical characteristics are described and the main experimental results obtained in the S2MA wind tunnel are discussed. Both wing-fuselage interferences and viscous effects, which are important on the wing due to a high rear loading, are investigated by performing 3D calculations. An attempt is made to find their limitations.

  18. 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

  19. Preferences for body type and body characteristics associated with attractive and unattractive bodies: Jackson and McGill revisited.

    PubMed

    Rosenfeld, L B; Stewart, S C; Stinnett, H J; Jackson, L A

    1999-10-01

    The present investigation replicates Jackson and McGill's study (1996) and extends it by considering the effects of respondents' own height, weight, and body mass on perceptions of attractiveness. Results, although generally supportive of those found by Jackson and McGill, point to the influence of respondents' own physical characteristics in the process of perceptions of attractiveness: only 1 of Jackson and McGill's 3 (of a possible 19) differences between responses of African- and Euro-American women was corroborated (the importance of silky hair for Euro-American women), whereas a second difference (the importance of round buttocks for African-American women) disappeared when controlling for respondents' weight, height, and body mass. Although differences between the two investigations may be attributed to regional differences in the surveyed students (Michigan and North Carolina), the small effect of one's own weight, height, and body mass in assessing an other-sex person's attractiveness may reflect adherence to norms learned very early in life that are subject to regional variations. PMID:10597583

  20. When are people interchangeable sexual objects? The effect of gender and body type on sexual fungibility.

    PubMed

    Gervais, Sarah J; Vescio, Theresa K; Allen, Jill

    2012-12-01

    The purpose of this research was to empirically examine the fungibility hypothesis derived from sexual objectification theory. Sexual objectification theorists have suggested that like objects, people, typically women, may be fungible or interchangeable with similar others. Despite its provocative nature and potential adverse psychological consequences, the fungibility hypothesis has yet to be empirically examined. We suggested that women, regardless of body types, but also men with body types that resemble the cultural ideal of attractiveness (e.g., large arms and chests and narrow waists), would be more fungible than men with body types that resemble the cultural average. Participants (n = 66) saw images of average and ideal women and men once before they completed a surprise matching task requiring that they match the bodies and faces that appeared together in the original images. Consistent with hypotheses, we found that women with ideal bodies, women with average bodies, and men with ideal bodies were more fungible (perceivers made more body-face pairing errors) than men with average bodies. Furthermore, it appears that when people are fungible they are interchangeable with people with similar body types. Implications and directions for future research on objectification and fungibility are discussed. PMID:23216316

  1. Urgent Intracranial Carotid Artery Decompression after Penetrating Head Injury

    PubMed Central

    Kim, Seong Joon

    2013-01-01

    We describe a case of intracranial carotid artery occlusion due to penetrating craniofacial injury by high velocity foreign body that was relieved by decompressive surgery. A 46-year-old man presented with a penetrating wound to his face. A piece of an electric angular grinder disc became lodged in the anterior skull base. Computed tomography revealed that the disc had penetrated the unilateral paraclinoid and suprasellar areas without flow of the intracranial carotid artery on the lesion side. The cavernous sinus was also compromised. Removal of the anterior clinoid process reopened the carotid blood flow, and the injection of glue into the cavernous sinus restored complete hemostasis during extraction of the fragment from the face. Digital subtraction angiography revealed complete recanalization of the carotid artery without any evidence of dissection. Accurate diagnosis regarding the extent of the compromised structures and urgent decompressive surgery with adequate hemostasis minimized the severity of penetrating damage in our patient. PMID:23634269

  2. 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 ( ...

  3. 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 ...

  4. Altered body composition in type 2 diabetes mellitus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The styd objectives were to identify differences in amount and distribution of fat and lean soft tissue in a cross-sectional study of subjects with and without type 2 diabetes, and to determine whether any differences are affected by race/ethnicity or sex. Participants were overweight and obese (bod...

  5. The evaluation of body image in children with type 1 diabetes: A case-control study.

    PubMed

    Troncone, Alda; Prisco, Francesco; Cascella, Crescenzo; Chianese, Antonietta; Zanfardino, Angela; Iafusco, Dario

    2016-04-01

    This study evaluated the body image perception in children with type 1 diabetes in order to identify symptoms of disordered eating behaviours early. Children with type 1 diabetes and controls showed underestimation and dissatisfaction with body size. The patients, especially girls, were more accurate in their perception of body size than the control group. The study sheds light on some of the underlying factors that may contribute to the development of disordered eating behaviours in adolescence. The causes of the differences of perception of body size are discussed. PMID:24752557

  6. Body Image Distortion and Exposure to Extreme Body Types: Contingent Adaptation and Cross Adaptation for Self and Other

    PubMed Central

    Brooks, Kevin R.; Mond, Jonathan M.; Stevenson, Richard J.; Stephen, Ian D.

    2016-01-01

    Body size misperception is common amongst the general public and is a core component of eating disorders and related conditions. While perennial media exposure to the “thin ideal” has been blamed for this misperception, relatively little research has examined visual adaptation as a potential mechanism. We examined the extent to which the bodies of “self” and “other” are processed by common or separate mechanisms in young women. Using a contingent adaptation paradigm, experiment 1 gave participants prolonged exposure to images both of the self and of another female that had been distorted in opposite directions (e.g., expanded other/contracted self), and assessed the aftereffects using test images both of the self and other. The directions of the resulting perceptual biases were contingent on the test stimulus, establishing at least some separation between the mechanisms encoding these body types. Experiment 2 used a cross adaptation paradigm to further investigate the extent to which these mechanisms are independent. Participants were adapted either to expanded or to contracted images of their own body or that of another female. While adaptation effects were largest when adapting and testing with the same body type, confirming the separation of mechanisms reported in experiment 1, substantial misperceptions were also demonstrated for cross adaptation conditions, demonstrating a degree of overlap in the encoding of self and other. In addition, the evidence of misperception of one's own body following exposure to “thin” and to “fat” others demonstrates the viability of visual adaptation as a model of body image disturbance both for those who underestimate and those who overestimate their own size. PMID:27471447

  7. Body Image Distortion and Exposure to Extreme Body Types: Contingent Adaptation and Cross Adaptation for Self and Other.

    PubMed

    Brooks, Kevin R; Mond, Jonathan M; Stevenson, Richard J; Stephen, Ian D

    2016-01-01

    Body size misperception is common amongst the general public and is a core component of eating disorders and related conditions. While perennial media exposure to the "thin ideal" has been blamed for this misperception, relatively little research has examined visual adaptation as a potential mechanism. We examined the extent to which the bodies of "self" and "other" are processed by common or separate mechanisms in young women. Using a contingent adaptation paradigm, experiment 1 gave participants prolonged exposure to images both of the self and of another female that had been distorted in opposite directions (e.g., expanded other/contracted self), and assessed the aftereffects using test images both of the self and other. The directions of the resulting perceptual biases were contingent on the test stimulus, establishing at least some separation between the mechanisms encoding these body types. Experiment 2 used a cross adaptation paradigm to further investigate the extent to which these mechanisms are independent. Participants were adapted either to expanded or to contracted images of their own body or that of another female. While adaptation effects were largest when adapting and testing with the same body type, confirming the separation of mechanisms reported in experiment 1, substantial misperceptions were also demonstrated for cross adaptation conditions, demonstrating a degree of overlap in the encoding of self and other. In addition, the evidence of misperception of one's own body following exposure to "thin" and to "fat" others demonstrates the viability of visual adaptation as a model of body image disturbance both for those who underestimate and those who overestimate their own size. PMID:27471447

  8. Hamiltonian Dynamics of Spider-Type Multirotor Rigid Bodies Systems

    SciTech Connect

    Doroshin, Anton V.

    2010-03-01

    This paper sets out to develop a spider-type multiple-rotor system which can be used for attitude control of spacecraft. The multirotor system contains a large number of rotor-equipped rays, so it was called a 'Spider-type System', also it can be called 'Rotary Hedgehog'. These systems allow using spinups and captures of conjugate rotors to perform compound attitude motion of spacecraft. The paper describes a new method of spacecraft attitude reorientation and new mathematical model of motion in Hamilton form. Hamiltonian dynamics of the system is investigated with the help of Andoyer-Deprit canonical variables. These variables allow obtaining exact solution for hetero- and homoclinic orbits in phase space of the system motion, which are very important for qualitative analysis.

  9. 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.

  10. Carotid-cardiac baroreflex influence on forearm vascular resistance during low level LBNP

    NASA Technical Reports Server (NTRS)

    Ludwig, David

    1990-01-01

    Twelve healthy males were tested at low levels of lower body negative pressure (LBNP) with and without artificial stimulation of the carotid-cardiac baroreceptors. The carotid-cardiac baroreceptors were stimulated by applying a pressure of 10 mmHg to the carotid artery via a pressurized neck chamber. During the procedure, forearm blood flow (FBF) and forearm vascular resistance (FVR) were measured using a Whitney mercury silastic strain gauge technique. FBF decreased while FVR increased with increased intensity of LBNP. Both FBF and FVR were unaffected by carotid-cardiac baroreceptor stimulation.

  11. 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

  12. How Can Carotid Artery Disease Be Prevented?

    MedlinePlus

    ... from the NHLBI on Twitter. How Can Carotid Artery Disease Be Prevented? Taking action to control your risk factors can help prevent or delay carotid artery disease and stroke . Your risk for carotid artery ...

  13. VO2 Max in Variable Type Exercise Among Well-Trained Upper Body Athletes.

    ERIC Educational Resources Information Center

    Seals, Douglas R.; Mullin, John P.

    1982-01-01

    The maximal oxygen consumption (VO2 max) of well-trained upper body athletes was compared to that of untrained individuals in four types of exercise: arm cranking, legs only cycling, graded treadmill running, and combined arm cranking and leg cycling. Results of the study showed that well-trained upper body athletes attained a significantly higher…

  14. 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

  15. 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

  16. Management of carotid artery stenosis

    PubMed Central

    Louridas, George; Junaid, Asad

    2005-01-01

    OBJECTIVE To clarify the definition of carotid artery diseases, the appropriateness of screening for disease, investigation and management of patients presenting with transient ischemic attacks, and management of asymptomatic carotid bruits. SOURCES OF INFORMATION MEDLINE was searched using the terms carotid endarterectomy, carotid disease, and carotid stenosis. Most studies offer level II or III evidence. Consensus statements and guidelines from various neurovascular societies were also consulted. MAIN MESSAGE Patients with symptoms of hemispheric transient ischemic attacks associated with >70% stenosis of the internal carotid artery are at highest risk of major stroke or death. Risk is greatest within 48 hours of symptom onset; patients should have urgent evaluation by a vascular surgeon for consideration of carotid endarterectomy (CEA). Patients with 50% to 69% stenosis might benefit from urgent surgical intervention depending on clinical features and associated comorbidity. Patients with <50% stenosis do not benefit from surgery. Asymptomatic patients with >60% stenosis should be considered for elective CEA. CONCLUSION Symptomatic carotid artery syndromes need urgent carotid duplex evaluation to determine the need for urgent surgery. Those with the greatest degree of stenosis derive the greatest benefit from timely CEA. PMID:16060177

  17. Sintering of beta-type alumina bodies using alpha-alumina encapsulation

    DOEpatents

    McEntire, Bryan J.; Virkar, Anil V.

    1981-01-01

    A method of sintering a shaped green, beta-type alumina body comprising: (A) inserting said body into an open chamber prepared by exposing the interior surface of a container consisting essentially of at least about 50 weight percent of alpha-alumina and a remainder of other refractory material to a sodium oxide or sodium oxide producing environment; (B) sealing the chamber; and heating the chamber with the shaped body encapsulated therein to a temperature and for a time necessary to sinter said body to the desired density. The encapsulation chamber prepared as described above is also claimed.

  18. Spontaneous closure of posttraumatic high-flow carotid-cavernous fistula following cerebral angiography

    PubMed Central

    Meena, Ugan Singh; Gupta, Pankaj; Shrivastava, Trilochan; Purohit, Devendra

    2016-01-01

    Traumatic carotid-cavernous fistula (TCCF) is a direct communication between cavernous portion of the internal carotid artery (ICA) and cavernous sinus due to tear in ICA. Most of the cases are treated by endovascular embolization. Spontaneous resolution of high-flow TCCFs is extremely rare. We report a case of posttraumatic, direct, high-flow carotid cavernous fistula (Barrow type A) that resolved spontaneously after cerebral angiography. PMID:27057229

  19. Spontaneous closure of posttraumatic high-flow carotid-cavernous fistula following cerebral angiography.

    PubMed

    Meena, Ugan Singh; Gupta, Pankaj; Shrivastava, Trilochan; Purohit, Devendra

    2016-01-01

    Traumatic carotid-cavernous fistula (TCCF) is a direct communication between cavernous portion of the internal carotid artery (ICA) and cavernous sinus due to tear in ICA. Most of the cases are treated by endovascular embolization. Spontaneous resolution of high-flow TCCFs is extremely rare. We report a case of posttraumatic, direct, high-flow carotid cavernous fistula (Barrow type A) that resolved spontaneously after cerebral angiography. PMID:27057229

  20. Vision System To Identify Car Body Types For Spray Painting Robot

    NASA Astrophysics Data System (ADS)

    Uartlam, Peter; Neilson, Geoff

    1984-02-01

    The automation of car body spray booth operations employing paint spraying robots generally requires the robots to execute one of a number of defined routines according to the car body type. A vision system is described which identifies a car body type by its shape and provides an identity code to the robot controller thus enabling the correct routine to be executed. The vision system consists of a low cost linescan camera, a flucrescens light source and a microprocessor image analyser and is an example of a cost effective, reliable, industrially engineered robot vision system for a demanding production environment. Extension of the system with additional cameras will increase the application to the other automatic operations on a car assembly line where it becomes essential to reliably differentiate between up to 40 vatiations of body types.

  1. 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

  2. Water-Body types identification in urban areas from radarsat-2 fully polarimetric SAR data

    NASA Astrophysics Data System (ADS)

    Xie, Lei; Zhang, Hong; Wang, Chao; Chen, Fulong

    2016-08-01

    This paper presents a novel method for supervised water-body extraction and water-body types identification from Radarsat-2 fully polarimetric (FP) synthetic aperture radar (SAR) data in complex urban areas. First, supervised water-body extraction using the Wishart classifier is performed, and the false alarms that are formed in built-up areas are removed using morphological processing methods and spatial contextual information. Then, the support vector machine (SVM), the classification and regression tree (CART), TreeBagger (TB), and random forest (RF) classifiers are introduced for water-body types (rivers, lakes, ponds) identification. In SAR images, certain other objects that are misclassified as water are also considered in water-body types identification. Several shape and polarimetric features of each candidate water-body are used for identification. Radarsat-2 PolSAR data that were acquired over Suzhou city and Dongguan city in China are used to validate the effectiveness of the proposed method, and the experimental results are evaluated at both the object and pixel levels. We compared the water-body types classification results using only shape features and the combination of shape and polarimetric features, the experimental results show that the polarimetric features can eliminate the misclassifications from certain other objects like roads to water areas, and the increasement of classification accuracy embodies at both the object and pixel levels. The experimental results show that the proposed methods can achieve satisfactory accuracies at the object level [89.4% (Suzhou), 95.53% (Dongguan)] and the pixel level [96.22% (Suzhou), 97.95% (Dongguan)] for water-body types classification, respectively.

  3. 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

  4. Unexpected Radiologic Findings for a Casting Type of Radiolucent Colorectal Foreign Body Composed of Polyurethane Foam

    PubMed Central

    Tamamoto, Fumihiko; Ogawa, Shoichi; Sano, Maiko; Yoshimura, Tetsunori; Nozaki, Miwako

    2016-01-01

    Radiologic diagnosis of colorectal foreign bodies is usually not very difficult, because inserted materials are often clearly visible on plain abdominal radiographs. However, when they are radiolucent, a plain abdominal radiograph has been reported to be useless. As radiolucent colorectal foreign bodies appear as radiolucent artificial contours or air-trapped materials in the pelvis, almost always the diagnosis itself can be made by careful evaluation of plain abdominal radiographs. We encountered a case of casting type of radiolucent colorectal foreign body formed from polyurethane foam. It presented us with unexpected radiologic findings and led to diagnostic difficulties. PMID:27213072

  5. Unexpected Radiologic Findings for a Casting Type of Radiolucent Colorectal Foreign Body Composed of Polyurethane Foam.

    PubMed

    Sanjo, Emi; Tamamoto, Fumihiko; Ogawa, Shoichi; Sano, Maiko; Yoshimura, Tetsunori; Nozaki, Miwako

    2016-01-01

    Radiologic diagnosis of colorectal foreign bodies is usually not very difficult, because inserted materials are often clearly visible on plain abdominal radiographs. However, when they are radiolucent, a plain abdominal radiograph has been reported to be useless. As radiolucent colorectal foreign bodies appear as radiolucent artificial contours or air-trapped materials in the pelvis, almost always the diagnosis itself can be made by careful evaluation of plain abdominal radiographs. We encountered a case of casting type of radiolucent colorectal foreign body formed from polyurethane foam. It presented us with unexpected radiologic findings and led to diagnostic difficulties. PMID:27213072

  6. Cervical carotid pseudoaneurysm: A carotid artery stenting complication

    PubMed Central

    Raso, Jair; Darwich, Rogerio; Ornellas, Carlos; Cariri, Gustavo

    2011-01-01

    Background: As carotid artery stenting becomes increasingly used, more complications are likely to occur. We present a case of Staphylococcus septicemia and pseudoaneurysm arising in the neck portion of the carotid artery after stenting. Case Description: A 51-year-old man was admitted with mild left hemiparesis. CT and MRI showed right hemisphere ischemia. Duplex Scan and MRA showed bilateral severe stenosis of the carotid arteries in the neck. A percutaneous angioplasty with stenting of the left carotid artery was performed. Two weeks after the procedure, he developed fever and swelling in the right leg and shoulder. An abscess, near where the groin had been punctured for the angioplasty was surgically drained. Blood samples were positive for S. aureus. After treatment the patient complained of a painful bulky pulsatile left cervical mass. Duplex scan and MRA showed a pseudoaneurysm of the left carotid artery. We excised the pseudoaneurysm and rebuilt the carotid artery with a saphenous vein graft. The postoperative period was uneventful, and the MRA revealed a patent saphenous graft. Conclusion: Mycotic pseudoaneurysm of the carotid artery is a rare complication of percutaneous angioplasty and stenting. Surgical treatment with saphenous vein graft is the treatment of choice. PMID:21748038

  7. Effect of current glycemic control on qualitative body composition in sedentary ambulatory Type 2 diabetics

    PubMed Central

    Solanki, Jayesh Dalpatbhai; Makwana, Amit H.; Mehta, Hemant B.; Kamdar, Panna; Gokhale, Pradnya A.; Shah, Chinmay J.

    2016-01-01

    Background: Obesity and Type 2 diabetes mellitus are on rise with cause–effect relationship. Diabetics monitor blood sugar, neglecting qualitative body composition, leaving residual threat of ectopic fat unattended. We tried to correlate glycemic triad with parameters of body composition derived objectively by bioelectrical impedance analysis (BIA). Materials and Methods: A sample of 78 under treatment sedentary Type 2 diabetics of either sex with known glycemic and lipidemic control from our city. Following baseline assessment measurement was done by instrument Omron Karada Scan (Model HBF-510, China) using the principle of tetra poplar BIA to derive parameters of body composition. We tried to correlate glycemic triad with these parameters, both directly as well as after defining them as per established cutoff norms. Results: We found poor glycemic control in the study group (20% for Hb1AC), high body mass index, subcutaneous fat, visceral fat (VF), total body fat (TBF), and lesser mass of skeletal muscle in Type 2 diabetics. However, there were small, insignificant, and inconsistent difference of these parameters while directly correlating with the fasting blood sugar, postprandial blood sugar, and glycosylated hemoglobin. On qualitative assessment, the impact of glycemic control as per standard norms, the risk of high VF, high TBF, low skeletal muscle mass was though high (between 1 and 2) in Type 2 diabetics with poor glycemic control as compared to good glycemics, but each strength lacks statistical significance. Conclusion: BIA reveals that Type 2 diabetics have more ectopic fat on expense of skeletal muscle that do not correlate with current glycemic status, both quantitatively and qualitatively. Measurement of body composition can be included and subjects can be motivated for lifestyle modification strategies while managing metabolic derangements of Type 2 diabetes. PMID:27185972

  8. Type of body fat distribution in postmenopausal women and its related factors

    PubMed Central

    Noroozi, Mahnaz; Rastegari, Zahra; Paknahad, Zamzam

    2010-01-01

    BACKGROUND: The type of body fat distribution has an important role for identifying risk of diseases. One of the simple anthropometric indexes for estimating type of body fat distribution is waist circumference index. This study is aimed to determine the type of body fat distribution in postmenopausal women and its related factors. METHODS: This is a cross sectional descriptive analytical study. Samples were 278 postmenopausal women in Isfahan who were selected by stratified sampling and then were invited to 64 health centers of Isfahan. Data was gathered using a questionnaire and standard meter. Data was analyzed using SPSS software and descriptive and inferential statistics. RESULTS: Results showed that in postmenopausal women the mean of waist circumference index was 93.63 (10.66) and its range was 54 to 119 cm. There was a meaningful relation between job, educational status, total pregnancies, total deliveries, age of first pregnancy, lactation history and menopausal age with waist circumference index. CONCLUSIONS: Results showed that the type of body fat distribution of postmenopausal women is of android type. Considering side effects of this kind of distribution, necessary teachings about healthy eating, movement and exercises must be given to women of these ages. PMID:21589746

  9. Dynamics and associations of microbial community types across the human body.

    PubMed

    Ding, Tao; Schloss, Patrick D

    2014-05-15

    A primary goal of the Human Microbiome Project (HMP) was to provide a reference collection of 16S ribosomal RNA gene sequences collected from sites across the human body that would allow microbiologists to better associate changes in the microbiome with changes in health. The HMP Consortium has reported the structure and function of the human microbiome in 300 healthy adults at 18 body sites from a single time point. Using additional data collected over the course of 12-18 months, we used Dirichlet multinomial mixture models to partition the data into community types for each body site and made three important observations. First, there were strong associations between whether individuals had been breastfed as an infant, their gender, and their level of education with their community types at several body sites. Second, although the specific taxonomic compositions of the oral and gut microbiomes were different, the community types observed at these sites were predictive of each other. Finally, over the course of the sampling period, the community types from sites within the oral cavity were the least stable, whereas those in the vagina and gut were the most stable. Our results demonstrate that even with the considerable intra- and interpersonal variation in the human microbiome, this variation can be partitioned into community types that are predictive of each other and are probably the result of life-history characteristics. Understanding the diversity of community types and the mechanisms that result in an individual having a particular type or changing types, will allow us to use their community types to assess disease risk and to personalize therapies. PMID:24739969

  10. Comparative analysis of the biaxial mechanical behavior of carotid wall tissue and biological and synthetic materials used for carotid patch angioplasty.

    PubMed

    Kamenskiy, Alexey V; Pipinos, Iraklis I; MacTaggart, Jason N; Kazmi, Syed A Jaffar; Dzenis, Yuris A

    2011-11-01

    Patch angioplasty is the most common technique used for the performance of carotid endarterectomy. A large number of patching materials are available for use while new materials are being continuously developed. Surprisingly little is known about the mechanical properties of these materials and how these properties compare with those of the carotid artery wall. Mismatch of the mechanical properties can produce mechanical and hemodynamic effects that may compromise the long-term patency of the endarterectomized arterial segment. The aim of this paper was to systematically evaluate and compare the biaxial mechanical behavior of the most commonly used patching materials. We compared PTFE (n  =  1), Dacron (n  =  2), bovine pericardium (n  =  10), autogenous greater saphenous vein (n  =  10), and autogenous external jugular vein (n  =  9) with the wall of the common carotid artery (n  =  18). All patching materials were found to be significantly stiffer than the carotid wall in both the longitudinal and circumferential directions. Synthetic patches demonstrated the most mismatch in stiffness values and vein patches the least mismatch in stiffness values compared to those of the native carotid artery. All biological materials, including the carotid artery, demonstrated substantial nonlinearity, anisotropy, and variability; however, the behavior of biological and biologically-derived patches was both qualitatively and quantitatively different from the behavior of the carotid wall. The majority of carotid arteries tested were stiffer in the circumferential direction, while the opposite anisotropy was observed for all types of vein patches and bovine pericardium. The rates of increase in the nonlinear stiffness over the physiological stress range were also different for the carotid and patching materials. Several carotid wall samples exhibited reverse anisotropy compared to the average behavior of the carotid tissue. A similar characteristic was

  11. Intracytoplasmic inclusion bodies in the chondrocytes of type I lethal achondrogenesis.

    PubMed

    Yang, S S; Heidelberger, K P; Bernstein, J

    1976-11-01

    Lethal achondrogenesis in the past has been frequently confused with achondroplasia. Clinical and radiologic advances in the last decade have led to clear differentiation of this condition from other types of bone dysplasia. It is further separated into two types on the basis of radiographic and pathologic findings. Re-evaluation of the histologic features has led to the recognition of heretofore unrecognized intracytoplasmic inclusion bodies in the chondrocytes of type 1 achondrogenesis. The finding of inclusions strengthens the differentiation of the two types and may have implications for the pathogenesis of the form of chondrodystrophy. PMID:186383

  12. Dynamical evolution of Chelyabinsk-type bodies from sungrazing orbits to near-Earth space

    NASA Astrophysics Data System (ADS)

    Emel'yanenko, V. V.

    2015-12-01

    Studies of the orbital evolution show that, with a high probability, the Chelyabinsk object was near the Sun about 1 Myr ago. This is consistent with the estimate of a cosmic ray exposure age (Popova et al., 2013). Dynamical features of the flux of Chelyabinsk-type bodies have been studied by numerical integrations, assuming their origin near the Sun about 1 Myr ago. The most frequent fate of these bodies is solar collision. But about a quarter of all the original objects survive until the present epoch. The majority of the surviving bodies are typical near-Earth objects. The rate of their encounters with the Earth is almost constant for the last 0.5 Myr. About a third of the Chelyabinsk-type objects approach the Earth from the Sun direction.

  13. Vacuolar ATPase regulates surfactant secretion in rat alveolar type II cells by modulating lamellar body calcium.

    PubMed

    Chintagari, Narendranath Reddy; Mishra, Amarjit; Su, Lijing; Wang, Yang; Ayalew, Sahlu; Hartson, Steven D; Liu, Lin

    2010-01-01

    Lung surfactant reduces surface tension and maintains the stability of alveoli. How surfactant is released from alveolar epithelial type II cells is not fully understood. Vacuolar ATPase (V-ATPase) is the enzyme responsible for pumping H(+) into lamellar bodies and is required for the processing of surfactant proteins and the packaging of surfactant lipids. However, its role in lung surfactant secretion is unknown. Proteomic analysis revealed that vacuolar ATPase (V-ATPase) dominated the alveolar type II cell lipid raft proteome. Western blotting confirmed the association of V-ATPase a1 and B1/2 subunits with lipid rafts and their enrichment in lamellar bodies. The dissipation of lamellar body pH gradient by Bafilomycin A1 (Baf A1), an inhibitor of V-ATPase, increased surfactant secretion. Baf A1-stimulated secretion was blocked by the intracellular Ca(2+) chelator, BAPTA-AM, the protein kinase C (PKC) inhibitor, staurosporine, and the Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), KN-62. Baf A1 induced Ca(2+) release from isolated lamellar bodies. Thapsigargin reduced the Baf A1-induced secretion, indicating cross-talk between lamellar body and endoplasmic reticulum Ca(2+) pools. Stimulation of type II cells with surfactant secretagogues dissipated the pH gradient across lamellar bodies and disassembled the V-ATPase complex, indicating the physiological relevance of the V-ATPase-mediated surfactant secretion. Finally, silencing of V-ATPase a1 and B2 subunits decreased stimulated surfactant secretion, indicating that these subunits were crucial for surfactant secretion. We conclude that V-ATPase regulates surfactant secretion via an increased Ca(2+) mobilization from lamellar bodies and endoplasmic reticulum, and the activation of PKC and CaMKII. Our finding revealed a previously unrealized role of V-ATPase in surfactant secretion. PMID:20169059

  14. The influence of vibration type, frequency, body position and additional load on the neuromuscular activity during whole body vibration.

    PubMed

    Ritzmann, Ramona; Gollhofer, Albert; Kramer, Andreas

    2013-01-01

    This study aimed to assess the influence of different whole body vibration (WBV) determinants on the electromyographic (EMG) activity during WBV in order to identify those training conditions that cause highest neuromuscular responses and therefore provide optimal training conditions. In a randomized cross-over study, the EMG activity of six leg muscles was analyzed in 18 subjects with respect to the following determinants: (1) vibration type (side-alternating vibration (SV) vs. synchronous vibration (SyV), (2) frequency (5-10-15-20-25-30 Hz), (3) knee flexion angle (10°-30°-60°), (4) stance condition (forefoot vs. normal stance) and (5) load variation (no extra load vs. additional load equal to one-third of the body weight). The results are: (1) neuromuscular activity during SV was enhanced compared to SyV (P < 0.05); (2) a progressive increase in frequency caused a progressive increase in EMG activity (P < 0.05); (3) the EMG activity was highest for the knee extensors when the knee joint was 60° flexed (P < 0.05); (4) for the plantar flexors in the forefoot stance condition (P < 0.05); and (5) additional load caused an increase in neuromuscular activation (P < 0.05). In conclusion, large variations of the EMG activation could be observed across conditions. However, with an appropriate adjustment of specific WBV determinants, high EMG activations and therefore high activation intensities could be achieved in the selected muscles. The combination of high vibration frequencies with additional load on an SV platform led to highest EMG activities. Regarding the body position, a knee flexion of 60° and forefoot stance appear to be beneficial for the knee extensors and the plantar flexors, respectively. PMID:22538279

  15. The Effect of Body Type and Camera Shot on Interpersonal Attraction and Source Credibility.

    ERIC Educational Resources Information Center

    McCain, Thomas A.; Divers, Lawrence

    In order to examine the effects of manipulating image size (i.e., relative size) and body type of speakers in a television context on source credibility and interpersonal attraction, a study was conducted at Illinois State University during the spring of 1973. Subjects were eighteen intact groups of students enrolled in speech communication class…

  16. The effects of vitamin D, K and calcium co-supplementation on carotid intima-media thickness and metabolic status in overweight type 2 diabetic patients with CHD.

    PubMed

    Asemi, Zatollah; Raygan, Fariba; Bahmani, Fereshteh; Rezavandi, Zohreh; Talari, Hamid Reza; Rafiee, Motahereh; Poladchang, Somayyeh; Darooghegi Mofrad, Manijeh; Taheri, Sara; Mohammadi, Ali Akbar; Esmaillzadeh, Ahmad

    2016-07-01

    This study was conducted to examine the effects of vitamin D, K and Ca co-supplementation on carotid intima-media thickness (CIMT) and metabolic status in overweight diabetic patients with CHD. This randomised, double-blind, placebo-controlled trial was conducted among sixty-six diabetic patients with CHD. Participants were randomly allocated into two groups to take either 5µg vitamin D, 90 µg vitamin K plus 500 mg Ca supplements (n 33) or placebo (n 33) twice a day for 12 weeks. Fasting blood samples were obtained at the beginning of the study and after the 12-week intervention period to determine related markers. Vitamin D, K and Ca co-supplementation resulted in a significant reduction in maximum levels of left CIMT (-0·04 (sd 0·22) v. +0·04 (sd 0·09) mm, P=0·02). Changes in serum vitamin D (+6·5 (sd 7·8) v. +0·4 (sd 2·2) ng/ml, P<0·001), Ca (+0·6 (sd 0·3) v. +0·1 (sd 0·1) mg/dl, P<0·001) and insulin concentrations (-0·9 (sd 3·1) v. +2·6 (sd 7·2) µIU/ml, P=0·01), homoeostasis model for assessment of estimated insulin resistance (-0·4 (sd 1·2) v. +0·7 (sd 2·3), P=0·01), β-cell function (-2·1 (sd 9·0) v. +8·9 (sd 23·7), P=0·01) and quantitative insulin sensitivity check index (+0·007 (sd 0·01) v. -0·006 (sd 0·02), P=0·01) in supplemented patients were significantly different from those in patients in the placebo group. Supplementation resulted in significant changes in HDL-cholesterol (+2·7 (sd 7·0) v. -2·5 (sd 5·7) mg/dl, P=0·002), high-sensitivity C-reactive protein (-1320·1 (sd 3758·3) v. +464·0 (sd 3053·3) ng/ml, P=0·03) and plasma malondialdehyde concentrations (-0·4 (sd 0·5) v. -1·0 (sd 1·1) µmol/l, P=0·007) compared with placebo. Overall, vitamin D, K and Ca co-supplementation for 12 weeks among diabetic patients with CHD had beneficial effects on maximum levels of left CIMT and metabolic status. The effect of vitamin D, K and Ca co-supplementation on maximum levels of left CIMT could be a chance

  17. Intracranial Pseudoaneurysms, Fusiform Aneurysms and Carotid-Cavernous Fistulas

    PubMed Central

    Lv, Xianli; Jiang, Chuhan; Li, Youxiang; Lv, Ming; Zhang, Jingbo; Wu, Zhongxue

    2008-01-01

    Summary The study assessed the effectiveness and safety of endovascular covered stents in the management of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Fourteen endovascular covered stents were used to repair three pseudoaneurysms, six fu-siform aneurysms and six direct carotid-cavernous fistulas. Aneurysms were in the carotid artery in seven cases, in the vertebral artery two cases. It was not possible to treat two additional cases transcutaneously for technical reasons
2/15. Percutaneous closure of the lesions with an endovascular covered stent was successful in 13 of 15 cases. Initial follow-up showed good stent patency. No complications were observed after stent implantation. During follow-up, stent thromboses were detected in two of nine patients with follow-up digital subtracted angiography. One carotid-cavernous fistula of Barrow Type A transformed into Barrow Type D at nine month follow-up study was cured with a procudure of Onyx-18 injection. Endovascular covered stents may be an option for percutaneous closure of intracranial pseudoaneurysms, fusiform aneurysms and direct carotid-cavernous fistulas. Endoluminal vascular repair with covered stents offers an alternative therapeutic approach to conventional modalities. PMID:20557743

  18. Body fat, fat distribution, and psychosocial factors among patients with Type 2 diabetes mellitus.

    PubMed

    Bell, R A; Summerson, J H; Spangler, J G; Konen, J C

    1998-01-01

    Diabetes, a risk factor for cardiovascular disease, requires lifestyle modifications (diet, exercise, weight loss). The relations between body mass index, waist-hip ratio (WHR), and psychosocial indicators, such as affect and stress, among 302 diabetic patients from a clinic and a neighborhood health center were analyzed. Data included stress and mood scale responses, body size (height, weight, and WHR) and potential confounders (physical activity, energy intake, and diabetes duration). In univariate analyses, body mass index was positively associated with stress and inversely associated with positive affect only in women. Multiple regression analyses indicated that stress was associated with body mass index and negative mood was associated with the WHR. The findings suggested that stress and affect may be important correlates of body fat among women with Type 2 diabetes, leading to more complications. Healthcare providers can help women with Type 2 diabetes lose weight and lower the risk of cardiovascular disease by recognizing and helping them deal with these psychosocial issues. PMID:9850808

  19. Protein dynamics in whole body and in splanchnic and leg tissues in type I diabetic patients.

    PubMed Central

    Nair, K S; Ford, G C; Ekberg, K; Fernqvist-Forbes, E; Wahren, J

    1995-01-01

    To elucidate the mechanism of insulin's anticatabolic effect in humans, protein dynamics were evaluated in the whole-body, splanchnic, and leg tissues in six C-peptide-negative type I diabetic male patients in the insulin-deprived and insulin-treated states using two separate amino acid models (leucine and phenylalanine). L-(1-13C,15N)leucine, L-(ring-2H5)phenylalanine, and L-(ring-2H2) tyrosine were infused intravenously, and isotopic enrichments of [1-13C,15N]-leucine, (13C)leucine, (13C)ketoisocaproate, (2H5)phenylalanine, [2H4]tyrosine, (2H2)tyrosine, and 13CO2 were measured in arterial, hepatic vein, and femoral vein samples. Whole-body leucine flux, phenylalanine flux, and tyrosine flux were decreased (< 0.01) by insulin treatment, indicating an inhibition of protein breakdown. Moreover, insulin decreased (< 0.05) the rates of leucine oxidation and leucine transamination (P < 0.01), but the percent rate of ketoisocaproate oxidation was increased by insulin (P < 0.01). Insulin also reduced (< 0.01) whole-body protein synthesis estimated from both the leucine model (nonoxidative leucine disposal) and the phenylalanine model (disposal of phenylalanine not accounted by its conversion to tyrosine). Regional studies demonstrated that changes in whole body protein breakdown are accounted for by changes in both splanchnic and leg tissues. The changes in whole-body protein synthesis were not associated with changes in skeletal muscle (leg) protein synthesis but could be accounted for by the splanchnic region. We conclude that though insulin decreases whole-body protein breakdown in patients with type I diabetes by inhibition of protein breakdown in splanchnic and leg tissues, it selectively decreases protein synthesis in splanchnic tissues, which accounted for the observed decrease in whole-body protein synthesis. Insulin also augmented anabolism by decreasing leucine transamination. Images PMID:7769135

  20. Worsening angle closure glaucoma and choroidal detachments subsequent to closure of a carotid cavernous fistula

    PubMed Central

    2012-01-01

    Background Carotid cavernous fistulas are abnormal communications between the cavernous sinus and the external or internal carotid arteries. Although rare, closure of carotid cavernous fistulas can lead to immediate ocular complications. To our knowledge, our case represents the first report of worsening angle closure glaucoma and choroidal detachments over an extended period of two months subsequent to closure of a carotid cavernous fistula. Case presentation A 70-year-old female with a history of primary angle closure glaucoma presented with 4 mm of proptosis, resistance to retropulsion, tortuous corkscrew blood vessels and an orbital bruit of the right eye. Diagnostic cerebral angiogram showed a small indirect Barrow type D right carotid cavernous fistula. Transarterial embolization was planned but repeat cerebral angiography prior to the procedure demonstrated spontaneous partial closure of the carotid cavernous fistula and the procedure was aborted. One month later, our patient was noted to have worsening vision and choroidal detachments of the right eye. She declined further testing and was thus started on self-administered manual carotid jugular compressions. One month later, she developed progressive worsening of her choroidal detachments and angle closure. She eventually opted for surgical intervention but repeat cerebral angiography showed significant thrombosis of the carotid cavernous fistula and no intervention was warranted. Examination two months later showed complete resolution of the choroidal detachments and open angles of both eyes. Conclusions Our patient demonstrated worsening angle closure glaucoma and choroidal detachments after spontaneous closure of her carotid cavernous fistula had been noted. Ocular complications, including acute angle closure, have been reported to occur immediately after closure of carotid cavernous fistulas, but not over months as in our patient. It is imperative that individuals who have undergone apparent closure

  1. Many-Body Effect in Spin Dephasing in n-Type GaAs Quantum Wells

    NASA Astrophysics Data System (ADS)

    Weng, Ming-Qi; Wu, Ming-Wei

    2005-03-01

    By constructing and numerically solving the kinetic Bloch equations we perform a many-body study of the spin dephasing due to the D'yakonov-Perel' effect in n-type GaAs (100) quantum wells for high temperatures. In our study, we include the spin-conserving scattering such as the electron-phonon, the electron-nonmagnetic impurity as well as the electron-electron Coulomb scattering into consideration. The dephasing obtained from our theory contains both the single-particle and the many-body contributions with the latter originating from the inhomogeneous broadening introduced by the DP term [J. Supercond.: Incorp. Novel Magn. 14 (2001) 245 Eur. Phys. J. B 18 (2000) 373]. Our result agrees very well with the experimental data [Phys. Rev. B 62 (2000) 13034] of Malinowski et al. We further show that in the case we study, the spin dephasing is dominated by the many-body effect.

  2. Lessons learnt from carotid artery trials.

    PubMed

    Van Damme, H; Limet, R

    2006-01-01

    The objective of the authors is to assess the natural history of carotid artery disease and the role of carotid intervention in preventing ipsilateral stroke. The development of endovascular techniques for correction of carotid artery stenoses made this less invasive technique very popular, with an inherent risk of unregulated overuse by a variety of medical specialists, who are not always well informed on the natural history of carotid artery disease. It re-opened the discussion on the value of carotid endarterectomy for stroke prophylaxis. This ongoing debate offers the opportunity to distil evidence-based guidelines for the management of extracranial carotid artery stenoses. In recent papers, some authors expressed doubts on the validity and general applicability of the results of the pivotal randomised trials of carotid endarterectomy. The excellent results in terms of operative outcome and long term stroke prevention would, according to certain comments, not be attainable in routine practice. Another criticism of carotid endarterectomy is its higher operative morbidity in terms of cranial nerve lesions and myocardial infarctions, compared to endovascular procedures. This consideration is, for some authors, the main reason to espouse carotid artery stenting as a better alternative to carotid endarterectomy. Any evidence supporting this point of view is missing. The supposed equivalence or non-inferiority of carotid artery stenting is purely speculative. The aim of this review paper is to summarize the crude data of carotid surgery trials. The authors aim to answer four questions. For which lesions is carotid endarterectomy most beneficial ? Are the results of randomised carotid surgery trials biased by the selection of patients ? Is operative morbidity, other than stroke, under-estimated ? Is carotid artery stenting safe and efficacious ? An in-depth review with a critical analysis is made of recently published and on-going trials, comparing carotid surgery

  3. Blunt carotid artery injury after minor facial trauma

    PubMed Central

    Murabit, Amera; Tredget, Edward E

    2012-01-01

    A healthy young man presented three days after suffering a punch to the face resulting in minimally displaced mandibular fractures. History revealed an episode of anterograde amnesia and a delayed episode of dysphonia. Apart from the fractured mandible, the physical examination was otherwise noncontributory. Imaging revealed severe luminal narrowing of the left cervical internal carotid artery distal to the carotid bifurcation, consistent with carotid dissection; and two focal hypodensities in the left frontal and parietal cortices, highly suggestive of acute secondary embolic infarcts. The patient was treated with systemic anticoagulation for three months and experienced no further neurological symptoms. His mandibular fractures, treated conservatively, healed without any complications. Blunt carotid artery injuries are uncommon and diverse. Neurological symptoms may develop in a delayed fashion, thus, a high index of suspicion based on knowledge of the injury mechanisms and patterns of associated injuries may enable earlier diagnosis and treatment. Angiographic imaging is essential for the diagnosis and classification of injury characteristics (eg, type, location, etc). Treatment must be considered on an individual patient basis depending on the presentation, grade and morphology of the lesion. Although no level I clinical trials exist on the topic, anticoagulation seems to be the treatment of choice in most cases and surgical intervention is not commonly indicated. Carotid artery dissection without complete thrombosis may be effectively treated with systemic anticoagulation or antiplatelet therapy in the majority of cases. PMID:23997588

  4. Blunt carotid artery injury after minor facial trauma.

    PubMed

    Murabit, Amera; Tredget, Edward E

    2012-01-01

    A healthy young man presented three days after suffering a punch to the face resulting in minimally displaced mandibular fractures. History revealed an episode of anterograde amnesia and a delayed episode of dysphonia. Apart from the fractured mandible, the physical examination was otherwise noncontributory. Imaging revealed severe luminal narrowing of the left cervical internal carotid artery distal to the carotid bifurcation, consistent with carotid dissection; and two focal hypodensities in the left frontal and parietal cortices, highly suggestive of acute secondary embolic infarcts. The patient was treated with systemic anticoagulation for three months and experienced no further neurological symptoms. His mandibular fractures, treated conservatively, healed without any complications. Blunt carotid artery injuries are uncommon and diverse. Neurological symptoms may develop in a delayed fashion, thus, a high index of suspicion based on knowledge of the injury mechanisms and patterns of associated injuries may enable earlier diagnosis and treatment. Angiographic imaging is essential for the diagnosis and classification of injury characteristics (eg, type, location, etc). Treatment must be considered on an individual patient basis depending on the presentation, grade and morphology of the lesion. Although no level I clinical trials exist on the topic, anticoagulation seems to be the treatment of choice in most cases and surgical intervention is not commonly indicated. Carotid artery dissection without complete thrombosis may be effectively treated with systemic anticoagulation or antiplatelet therapy in the majority of cases. PMID:23997588

  5. Effects of Royal Jelly Supplementation on Body Weight and Dietary Intake in Type 2 Diabetic Females

    PubMed Central

    Pourmoradian, Samira; Mahdavi, Reza; Mobasseri, Majid; Faramarzi, Elnaz; Mobasseri, Mehrnoosh

    2012-01-01

    Background: The objective of the current study was to assess the effects of royal jelly supple-mentation on body weight, total daily energy and macronutrients intakes in type2 diabetic fe-males. Methods: In this randomized clinical trial, fifty female volunteers with type2 diabetes were as-signed into the supplemented (n=25) and placebo (n=25) groups, given a daily dose of 1000 mg royal jelly soft gel or placebo, for 8 weeks, respectively. Before and after the intervention, body weight and height of subjects were measured and body mass index was calculated. Dietary intake of patients was assessed using 24-hour food recall questionnaire for three non consecutive days (including 1 weekend day) and analyzed with Nutritionist IV software. The normally distributed data were compared using paired and independent t-tests, where appropriate. Results: Royal jelly supplementation significantly (P<0.01) decreased the mean body weight (72.45±4.42 vs. 71.00±6.44 kg) while it increased insignificantly in placebo group (73.02±6.44 vs 73.52±6.80 kg). Royal jelly supplementation resulted in significant decrease of mean daily total energy (P<0.01) and carbohydrate (P<0.01) intakes, while in placebo group the mean daily total energy and fat intakes were increased significantly (P<0.05). Conclusion: Supplementation with royal jelly may be beneficial in weight management of di-abetic patients. PMID:24688939

  6. 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

  7. The two types of stethoscope systems for respiration system diagnostics of the human body

    NASA Astrophysics Data System (ADS)

    Abashkin, Vladimir; Achimova, Elena

    2003-12-01

    An acoustic multimode fiber optic sensors for medical diagnostics based upon the shutter principle has been elaborated with semiconductor laser diode as light source. The construction and the method of component preparation are described. Other type of stethoscope is electrical one. Both stethoscopes are four channels. The kinetics and dynamic vibrations and sounds of the human body can be detected, acquired and then processing by personal computer for medical diagnostics.

  8. Sympathoinhibition and hypotension in carotid sinus hypersensitivity.

    PubMed

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

    1992-12-01

    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. PMID:1290922

  9. 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.

  10. 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 ...