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Sample records for cat carotid body

  1. Chronic hyperoxic effects on cat carotid body catecholamines and structure.

    PubMed

    Mokashi, A; Di Guilio, C; Morelli, L; Lahiri, S

    1994-06-01

    To account for the loss of O2 chemoreception in the cat carotid body during chronic hyperoxia, we studied the putative neurotransmitter correlates. Also, we studied the structural aspect of the carotid body tissues. We found that catecholamine concentrations increased and that the densecored vesicles in the glomus cells were not depleted, indicating that a lack of transmitters was not the cause for the loss of O2 chemoreception.

  2. 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.

  3. Modulatory effects of histamine on cat carotid body chemoreception.

    PubMed

    Del Rio, Rodrigo; Moya, Esteban A; Koenig, Cecilia S; Fujiwara, Kunio; Alcayaga, Julio; Iturriaga, Rodrigo

    2008-12-31

    Histamine has been proposed to be an excitatory transmitter between the carotid body (CB) chemoreceptor (glomus) cells and petrosal ganglion (PG) neurons. The histamine biosynthetic pathway, its storage and release, as well as the presence of histamine H1, H2 and H3 receptors have been found in the CB. However, there is only indirect evidence showing the presence of histamine in glomus cells, or weather its application produces chemosensory excitation. Thus, we studied the histamine immunocytochemical localization in the cat CB, and the effects of histamine, and H1, H2 and H3 receptor blockers on carotid sinus nerve (CSN) discharge, using CB and PG preparations in vitro. We found histamine immunoreactivity in dense-cored vesicles of glomus cells. Histamine induced dose-dependent increases in CSN discharge in the CB, but not in the PG. The H1-antagonist pyrilamine reduced the CB responses induced by histamine, the H2-antagonists cimetidine and ranitidine had no effect, while the H3-antagonist thioperamide enhanced histamine-induced responses. Present data suggests that histamine plays an excitatory modulatory role in the generation of cat CB chemosensory activity.

  4. Efferent inhibition of carotid body chemoreception in chronically hypoxic cats.

    PubMed

    Lahiri, S; Smatresk, N; Pokorski, M; Barnard, P; Mokashi, A

    1983-11-01

    The effects of chronic hypoxia on carotid chemoreceptor afferent activity before and after sectioning the carotid sinus nerves (CSN) were studied in cats exposed to 10% O2 for 21-49 days in a chamber at sea level. For comparison, chronically normoxic cats at sea level were also studied. The cats were anesthetized, paucifiber preparation for the measurement of carotid chemosensory activity from a small slip of CSN was made, and their steady-state responses to 4-5 levels of arterial pressure of O2 (PaO2) at a constant PaCO2 and to 3-4 levels of PaCO2 in hyperoxia were measured before and after sectioning the CSN. The chemosensory response to hypoxia in the cats with intact CSN after chronic exposure to hypoxia was not reduced relative to the cats that breathed room air at sea level. Sectioning the CSN significantly augmented the chemosensory responses to hypoxia in all the chronically hypoxic but not significantly in the normoxic cats. The responses to moderate hypercapnia during hyperoxia were not significantly changed by cutting the CSN in either group. We conclude that there is a significant CSN efferent inhibition of chemosensory activity due to chronic hypoxia in the cat. This implies that without the efferent inhibition the hypoxic chemosensitivity is increased by chronic hypoxia.

  5. Carbonic anhydrase and chemoreception in the cat carotid body.

    PubMed

    Iturriaga, R; Lahiri, S; Mokashi, A

    1991-10-01

    To test the hypothesis that CO2 and O2 chemoreception in the carotid body (CB) may depend on its carbonic anhydrase (CA) activity, we used an in vitro cat CB preparation and studied the effects of methazolamide, a permeable CA inhibitor (pK 7.3), on the chemosensory responses to CO2, O2, and nicotine. The isolated CB was perfused and superfused with Tyrode solution, free of CO2-HCO3-, at 36.0 +/- 0.5 degrees C. The frequency of chemosensory discharges was recorded from the whole carotid sinus nerve. The responses to bolus injections (0.3-0.5 ml) of Tyrode solution equilibrated with PCO2 of 38-110 Torr, switching from HEPES to CO2-HCO3- Tyrode (PCO2 = 25-60 Torr) for about 3 min, hypoxic Tyrode (PO2 = 25-30 Torr) for 2-8 min, perfusate flow interruptions for approximately 4 min, and bolus injections of nicotine (4 nmol) were studied before, during, and after perfusion (30-45 min) with methazolamide (42.4 microM). Methazolamide reversibly inhibited, delayed, and reduced the responses to transient CO2 stimulus, diminished the onset of but not the late response to prolonged CO2 stimulus, and delayed but did not decrease the responses to hypoxia and perfusate interruption. The response to nicotine did not change. The results indicated that CA in the glomus cells played a crucial role primarily in the speed and magnitude of the initial response to CO2 stimulus and indirectly influenced O2 chemoreception. These effects were upstream from the nicotine receptor-mediated sensory response.

  6. Anion exchanger and chloride channel in cat carotid body chemotransduction.

    PubMed

    Iturriaga, R; Mokashi, A; Lahiri, S

    1998-05-28

    In order to test the hypothesis that carotid body (CB) chemoreception depends on the functions of anion channels and HCO3-/Cl- exchangers, we studied the effects of the anion channel blocker anthracene-9-carboxylic acid (9-ANC), the carbonic anhydrase inhibitor methazolamide, and the HCO3-/Cl- exchanger blocker 4,4 diisothiocyanatostilbene-2-2'disulfonic acid (DIDS) on the chemosensory discharges of cat CB, perfused-superfused in vitro at 36.5 +/- 0.5 degrees C, with a modified Tyrode solution. The chemosensory responses to hypoxia (PO2 approximately 50 Torr), hypercapnia (PCO2 approximately 60 Torr, pH = 7.10), nicotine (2-4 nmol) and NaCN (20-40 nmol) were recorded. 9-ANC (2 microM) and DIDS (10 microM) decreased the chemosensory baseline activity, and eliminated the initial peak responses to hypercapnia and hypoxia and increased the time to achieve it. Methazolamide (0.13 mM) did not alter the effect of 9-ANC. The steady state responses to hypoxia and hypercapnia were not diminished after 9-ANC but DIDS lowered the responses. Responses to NaCN effects were all diminished but those to nicotine were not affected. The results suggest that the functions of anion channels and HCO3-/Cl- exchangers are important for the resting dischargers and for the fast responses to hypoxia and hypercapnia.

  7. Effects of naloxone on carotid body chemoreception and ventilation in the cat.

    PubMed

    Pokorski, M; Lahiri, S

    1981-12-01

    The effects of intravenous injection of naloxone (0.4 mg.kg-1), an opiate antagonist, on the responses of carotid body chemoreceptor discharge and ventilation to steady-state levels of hypoxia and hypercapnia were investigated in 12 anesthesized cats. After naloxone, carotid chemoreceptor response to hypoxia (PaO2 60--30 Torr) was enhanced, a finding that suggested that the endogenous enkephalin-like peptide present in the carotid body inhibits carotid chemoreceptors. This reasoning is supported by the observation that close intra-arterial injection of met-enkephalin inhibits carotid chemoreceptors and that the effect is blocked by naloxone. After naloxone, ventilation was stimulated even in the absence of a significant stimulation of carotid chemoreceptors during hyperoxia, indicating that ventilation is normally suppressed by endogenous opiates in the central nervous system, an effect disinhibited by naloxone. Also, the ventilatory effect of the peripheral chemoreceptor input was augmented after naloxone.

  8. Cat carotid body chemoreceptor responses before and after nicotine receptor blockade with alpha-bungarotoxin.

    PubMed

    Mulligan, E; Lahiri, S

    1987-01-01

    The nature of nicotine receptors in the carotid body was studied in anesthetized, paralyzed and artificially ventilated cats. Chemoreceptor discharge in single or few-fiber preparations of the carotid sinus nerve was measured during isocapnic hypoxia, hyperoxic hypercapnia and in response to nicotine injections before and after administration of alpha-bungarotoxin (10 cats) and after alpha-bungarotoxin plus mecamylamine (7 cats) which binds to neuromuscular-type nicotine cholinergic receptors. alpha-Bungarotoxin caused a slight enhancement of the chemoreceptor response to hypoxia without affecting the chemoreceptor stimulation by nicotine. Mecamylamine (1-5 mg, i.v.), a ganglionic-type nicotinic receptor blocker, had no further effect on the response to hypoxia while it completely abolished the chemoreceptor stimulation by nicotine. Thus the nicotinic receptors in the cat carotid body which elicit excitation of chemosensory fibers appear to be of the ganglionic-type. Blockade of neuromuscular and ganglionic types of nicotinic receptors in the carotid body by alpha-bungarotoxin and mecamylamine does not attenuate the chemosensory responses to either hypoxia or hypercapnia. These nicotinic receptors therefore, do not appear to play an essential role in hypoxic or hypercapnic chemoreception in the cat carotid body.

  9. Aortic and carotid body chemoreception in prolonged hyperoxia in the cat.

    PubMed

    Mokashi, A; Lahiri, S

    1991-11-01

    Carotid body chemosensory response to hypoxia is attenuated as a result of prolonged normobaric hyperoxia (NH) in the cat. The effect of NH is likely to be due to high cellular PO2 and O2-related free radicals. Accordingly, the effect would be less if O2 delivery to the chemoreceptor tissue could be compromised. The aortic bodies, which appear to have less of a circulatory O2 delivery, as suggested by their vigorous responses to a slight compromise of O2 flow compared with those of the carotid body, could provide a suitable testing material for the hypothesis. We tested the hypothesis by studying both aortic and carotid body chemoreceptors in the same cats (n = 6) which were exposed to nearly 100% O2 for about 60 h. These chemoreceptor organs were also studied in 6 control cats which were maintained in room air at sea-level. The cats were anesthetized and their carotid and aortic chemosensory fibers were identified by the usual procedure, and their responses to hypoxia and hypercapnia and to bolus injections (i.v.) of cyanide and nicotine were measured. In the NH cats, the carotid but not aortic chemosensory responses to hypoxia and cyanide were attenuated and to hypercapnia (both onset and steady state) augmented. The aortic chemoreceptors were stimulated by hypoxia, hypercapnia, cyanide and nicotine both in the NH and the control cats similarly. The results support the hypothesis that it is presumably a higher tissue blood flow and hence a higher concentration of O2-related free radicals which ultimately led to the specific attenuation of O2 chemoreception in the carotid body.

  10. Evidence for two types of nicotinic receptors in the cat carotid body chemoreceptor cells.

    PubMed

    Obeso, A; Gómez-Niño, M A; Almaraz, L; Dinger, B; Fidone, S; González, C

    1997-04-18

    Current concepts on the location and functional significance of nicotinic receptors in the carotid body rest on alpha-bungarotoxin binding and autoradiographic studies. Using an in vitro preparation of the cat carotid body whose catecholamine deposits have been labeled by prior incubation with the tritiated natural precursor [3H]tyrosine, we have found that nicotine induces release of [3H]catecholamines in a dose-dependent manner (IC50 = 9.81 microM). We also found that mecamylamine (50 microM) completely abolished the nicotine-induced release, while alpha-bungarotoxin (100 nM; approximately 20 times its binding Kd) only reduced the release by 56%. These findings indicate that chemoreceptor cells, and perhaps other carotid body structures, contain nicotinic receptors that are not sensitive to alpha-bungarotoxin and force a revision of the current concepts on cholinergic mechanisms in the carotid body chemoreception.

  11. Occurrence of neutral endopeptidase activity in the cat carotid body and its significance in chemoreception.

    PubMed

    Kumar, G K; Runold, M; Ghai, R D; Cherniack, N S; Prabhakar, N R

    1990-05-28

    The carotid body contains both tachykinins and enkephalins. Neutral endopeptidase (NEP, E.C. 3.4.24.11), has been suggested to involve in the metabolism of these neuropeptides in several organs. In the present study we determined neutral endopeptidase activity of the cat carotid body and assessed its significance in chemoreception. The cytosolic and membrane fractions of the carotid body contained NEP-like activity whereas it occurred only in the membrane fractions of the superior cervical and the nodose ganglia. Phosphoramidon, thiorphan and metal ion chelators inhibited NEP-like activity of all the 3 tissues studied; other protease inhibitors, however, were ineffective. Close carotid body administration of phosphoramidon significantly potentiated the carotid body response to low PO2 but not to hypercapnia. The enhanced response to hypoxia following phosphoramidon was further augmented by naloxone, an enkephalin antagonist. These results demonstrate that the glomus tissue contains detectable amounts of NEP-like activity and its inhibition selectively affects the hypoxic response of the carotid body.

  12. Optical measurements of the dependence of chemoreception on oxygen pressure in the cat carotid body.

    PubMed

    Rumsey, W L; Iturriaga, R; Spergel, D; Lahiri, S; Wilson, D F

    1991-10-01

    The relationship between oxygen pressure (PO2) in the carotid body and carotid sinus nerve discharge was evaluated in the isolated perfused/superfused cat carotid body using the oxygen-dependent quenching of phosphorescence. Images of phosphorescence intensity arising from Pd-coproporphyrin within the microcirculation of the carotid body provided measurements of intravascular PO2. These measurements were substantiated by determining phosphorescence life-time. The carotid body was perfused in the isolated state via the common carotid artery with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid-buffered Tyrode solution, pH 7.4, at a constant pressure of 80 mmHg. Superfusion was maintained with similar media equilibrated with 100% argon. PO2 in the exchange vessels was markedly less than that in the perfusate entering the carotid artery, 23 +/- 3 and 45 +/- 3 Torr for normoxic (111 +/- 15 Torr) and hyperoxic (345 +/- 72 Torr) perfusates, respectively. Chemosensory discharge rose slowly in response to a brief interruption of perfusate flow as PO2 steadily declined from either of these capillary PO2 values to approximately 10 Torr. Between approximately 10 and 3 Torr, chemosensory discharge increased strikingly, concomitant with an enhanced rate of oxygen disappearance, from -36 +/- 4 to -69 +/- 13 (92% change) and -28 +/- 3 to -48 +/- 3 (71% change) Torr/s for normoxic and hyperoxic perfusates, respectively. As PO2 fell below approximately 3 Torr, oxygen disappearance slowed and neural activity decayed. Thus the relationships between microvascular PO2 and chemosensory discharge and between oxygen disappearance and neural discharge suggest that oxygen metabolism in the carotid body determines the expression of oxygen chemoreception.

  13. 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.

  14. Hydrogen sulfide activates the carotid body chemoreceptors in cat, rabbit and rat ex vivo preparations.

    PubMed

    Jiao, Yingfu; Li, Qian; Sun, Biying; Zhang, Guohua; Rong, Weifang

    2015-03-01

    We and others previously reported experimental evidence suggesting an important role for hydrogen sulfide (H2S) in oxygen sensing in murine carotid body chemoreceptors. More recent data implicated abnormal H2S-mediated chemoreceptor signaling in pathological conditions such as chronic heart failure and hypertension. However, the idea of H2S as a mediator of oxygen-sensing in chemoreceptors has been challenged. In particular, it was shown that exogenous H2S inhibited the release of neurotransmitters (ACh and ATP) from the cat carotid body, raising the possibility that there exists significant species difference in H2S-mediated signaling in chemoreceptors. This study was designed specifically to determine the effect of H2S on chemoreceptors in different species. We conducted multiunit extracellular recordings of the sinus nerve in the ex vivo carotid body preparation taken from the rat, the cat and the rabbit. As observed in the mouse carotid body, H2S donors (NaHS or Na2S) evoked qualitatively similar excitatory responses of the afferent sinus nerves of the species studied here. The excitatory effects of the H2S donors were concentration-dependent and reversible. The sinus nerve responses to H2S donors were prevented by blockade of the transmission between type I cells and the afferent terminals, as was the response to hypoxia. These results demonstrate that exogenous H2S exerts qualitatively similar excitatory effects on chemoreceptor afferents of different species. The role of endogenous H2S-mediated signaling in carotid body function in different species awaits further investigation.

  15. Endothelins in the cat petrosal ganglion and carotid body: effects and immunolocalization.

    PubMed

    Rey, Sergio; Del Rio, Rodrigo; Alcayaga, Julio; Iturriaga, Rodrigo

    2006-01-19

    In response to hypoxia, chemoreceptor cells of the carotid body (CB) release transmitters, which acting on the petrosal ganglion (PG) neuron terminals, increase the chemoafferent discharge. Additionally, vasoactive molecules produced within the CB may modulate hypoxic chemoreception by controlling blood flow and tissue PO2. Endothelin-1 (ET-1) increases basal CB chemosensory discharges in situ, probably due to its vasoconstrictor action. However, the actions of ET-1 on PG neurons or its expression in the PG are not known. Using immunohistochemistry, we found that endothelin-like peptides are expressed in the cat PG and CB under normoxic conditions. Exogenous applications of ET-1 increased the chemosensory activity in the vascularly perfused CB but were ineffective on either the CB or PG superfused preparations, both of which are devoid of vascular control. Thus, our data indicate that the excitatory effect of ET-1 in the carotid chemoreceptor system appears to be mainly due to a vasoconstrictor effect in the CB blood vessels.

  16. CO reveals dual mechanisms of O2 chemoreception in the cat carotid body.

    PubMed

    Lahiri, S; Iturriaga, R; Mokashi, A; Ray, D K; Chugh, D

    1993-11-01

    The hypothesis that CO-binding pigments in the carotid body participate in O2 chemoreception was tested. The chemosensory nerve discharges of cat carotid body perfused and superfused in vitro at 36-37 degrees C with cell-free solution containing CO2-HCO3- (pH approximately equal to 7.39) were recorded to monitor O2 chemoreception. Several levels of PCO (60-550 Torr) at two levels of PO2 (50 Torr-140 Torr) were used. With high PCO of 500-550 Torr at any PO2 the discharge rate peaked promptly but the effect was significantly less than that to hypoxia. At any stage of the CO effect, exposure to light promptly attenuated or eliminated the response, as if the stimulatory effect of hypoxia was absent. Lower PCO of 60-70 Torr attenuated the response to hypoxia which was not suppressed by light. PCO of 140 Torr also attenuated the response to hypoxia and made the activity partially photolabile. During high PCO exposure the excitatory response to cyanide but not to nicotine was attenuated, consistent with the idea that the effects of nicotine are downstream from those of CO. Both inhibitory and excitatory effects of CO were promptly reversible. The results indicate that two types of CO-binding chromophores participate in O2 chemoreception in the carotid body.

  17. Contribution of in vivo microvascular PO2 in the cat carotid body chemotransduction.

    PubMed

    Lahiri, S; Rumsey, W L; Wilson, D F; Iturriaga, R

    1993-09-01

    To understand the interplay between microcirculatory control and carotid body (CB) function, we simultaneously measured carotid body microvascular PO2 (CBM PO2) and chemosensory activity in the cat in vivo under several experimental conditions. Cats were anesthetized with pentobarbital sodium, paralyzed, and artificially ventilated. CBs were exposed, and steady-state CBM PO2 was measured by the O2-dependent quenching of the phosphorescence of Pd-meso-tetra-(4-carboxyphenyl)porphine, which was administered intravenously. A few fibers of the carotid sinus nerve were used to record chemosensory discharges. At arterial PO2 (PaO2) of 103.4 +/- 4.1 Torr, CBM PO2 was 52.5 +/- 3.6 Torr (n = 9). Graded lowering of PaO2 from 160 to 50 Torr resulted in nearly proportional decreases in CBM PO2, but at lower PaO2 the decrease in CBM PO2 became more substantial. As PaO2 decreased, chemosensory discharge increased in parallel with CBM PO2. Hypercapnia and hypocapnia did not significantly change the relationship between PaO2 and CBM PO2, although the chemosensory discharge responded significantly. CBM PO2 and chemosensory discharge were not affected by hemorrhagic hypotension until arterial blood pressure fell below approximately 50 Torr and then CBM PO2 decreased and chemosensory discharge increased. The lack of a significant effect of hemorrhagic hypotension indicated that O2 delivery to CB was almost independent of the systemic blood pressure. Taken together, the observations suggest that CB microcirculation and PO2 are subject to control by intrinsic mechanisms and that CBM PO2 is compatible with oxidative metabolism playing a role in O2 chemoreception during hypoxia.

  18. Effect of hypoxia and hypercapnia on catecholamine content in cat carotid body.

    PubMed

    Fitzgerald, R S; Garger, P; Hauer, M C; Raff, H; Fechter, L

    1983-05-01

    The purpose of this study was to determine the content of catecholamines (CA) in the cat carotid body before and after 0.5 h exposures to normoxic normocapnia [arterial O2 partial pressure (Pao2) 126 +/- 28 Torr, arterial CO2 partial pressure (Paco2) 36.4 +/- 1.5 Torr], hypoxic normocapnia (Pao2 25 +/- 3 Torr, Paco2 36.7 +/- 3.3 Torr), and normoxic hypercapnia (Pao2 132 +/- 13 Torr, Paco2 = 98.2 +/- 7.6 Torr). CA synthesis was blocked using alpha-methylparatyrosine methyl ester (AMPT) prior to alterations in the inspired air. There was a significant decrease in carotid body content of dopamine (DA), norepinephrine (NE), and epinephrine (E) 1 h after AMPT administration. Analysis of variance and Duncan new multiple range procedures revealed that during the subsequent 0.5-h exposures to normoxia, hypoxia, or hypercapnia, only the decrease in DA during hypoxia was significantly greater than that during normoxia; the loss during hypercapnia was not. The decreases in NE during the three exposures were indistinguishable among themselves as were the decreases in E. The decrease in CA content is probably attributable to increased release. The data reveal that the release of CAs during the chemoreception of hypoxia is different from that during the chemoreception of hypercapnia and support the concept of different mechanisms for the chemoreception of hypoxia and hypercapnia.

  19. Cat carotid body oxygen metabolism and chemoreception described by a two-cytochrome model.

    PubMed

    Nair, P K; Buerk, D G; Whalen, W J

    1986-02-01

    We have analyzed O2 disappearance curves (DCs) in cat carotid bodies (CBs) measured with our O2 microelectrode, after stopping flow of either blood (108 DCs in 12 cats) or a hemoglobin-free (Locke) perfusion solution (35 DCs in 6 cats). Prior to occlusion, the mean tissue PO2 levels were 74.5 +/- 2.8 (SE) Torr in blood-perfused CBs and 103.4 +/- 2.6 in Locke-perfused CBs. The O2 consumption rates (VO2) determined from the initial 3 s of the DCs were 1.46 +/- 0.08 and 1.50 +/- 0.10 (SE) ml O2 . 100 g-1 . min-1, respectively, for the blood-perfused and Locke-perfused CBs. The change in total sinus nerve activity from the CB was also measured following stopped flow. The nerve activity began to increase immediately, providing further evidence that classic hypoxia is not the mechanism of chemoreceptor discharge. However, about two-thirds of the increased activity in blood-perfused CBs occurred after tissue PO2 levels fell below 20 Torr. As the CB tissue PO2 decreased, the O2 disappearance rate (-dPO2/dt) also decreased for both experimental conditions, indicating that the CB VO2 varies with O2 concentration. The increase in nerve discharge and O2 disappearance rate can be interpreted by a two-cytochrome model for O2 metabolism, with both high and low affinities.

  20. Stimulus interaction between CO and CO2 in the cat carotid body chemoreception.

    PubMed

    Osanai, S; Chugh, D K; Mokashi, A; Lahiri, S

    1996-03-04

    Since high PCO in the dark works like hypoxia in the carotid body chemoreceptors and since hypoxia shows a stimulus interaction with CO2, it is hypothesized that high PCO will show a similar interaction with PCO2 in the chemosensory excitation in the dark. We tested the hypothesis using cat carotid body perfused and superfused in vitro with Po2 of about 100 Torr. In one series, the chemosensory discharges were tested at three levels of PCO2 at high PCO of 500 Torr in the absence and presence of light. In the dark, normocapnia (PCO2 approximately 30 Torr) with high PCO promptly stimulated the sensory discharges to a peak, subsiding to a lower level. In hypocapnia (PCO2 approximately 18 Torr) with high PCO, all phases of activities were significantly lower than those of normocapnia, showing stimulus interaction. Hypercapnia saturated the activity with high PCO and seems to preclude a clear demonstration of stimulus interaction. In another series, an intermediate level of PCO (approximately 150 Torr), which showed a half-maximal activity in normoxia, showed a clear interaction with hypercapnia in the dark. With high PCO, bright light promptly reduced the activity to baseline at all PCO2 levels. This then increased somewhat to a steady-state. Withdrawal of the light was followed by a sharp rise in the activity to a peak which then fell to a somewhat lower level of steady-state. The peak discharge rate in the presence of light did not differ significantly from those of PCO2 alone.

  1. Intracellular pH and oxygen chemoreception in the cat carotid body in vitro.

    PubMed

    Iturriaga, R; Rumsey, W L; Lahiri, S; Spergel, D; Wilson, D F

    1992-06-01

    To test the hypothesis that O2 chemoreception in the carotid body (CB) is mediated by cellular acidosis, we simultaneously measured responses of the chemosensory and intracellular pH (pHi) to agents that are known to change pHi and studied the effects of hypoxia and ischemia on these variables in the cat CB. The CB was perfused and superfused in vitro with a modified Tyrode's solution at 36.0 +/- 0.5 degrees C with or without CO2-HCO3- (pH 7.40) and equilibrated at a given PO2. Chemosensory discharges were recorded from the whole carotid sinus nerve. To measure pHi changes, the CB was loaded with the pH-sensitive indicator 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, and the fluorescence (excitation 420-490 nm, emission greater than 515 nm) was detected by an intensified charged coupled device camera with an epifluorescence macroscope. Boluses of Tyrode's solution (0.5 ml, free of CO2-HCO3-) containing sodium acetate or NH4Cl prolonged perfusion of acid Tyrode's solution (pH 7.20-6.50), and boluses of Tyrode's solution with CO2-HCO3- were used. A decrease of fluorescence indicated pHi turning acid, and an increase of fluorescence indicated a change in alkaline pHi. Chemosensory activity varied inversely with the fluorescence change after application of these agents. Interruption of perfusate flow or application of hypoxic perfusate resulted in large increases in chemosensory discharge without any change in the fluorescence. The results indicated that chemosensory responses to brief ischemia and hypoxia were not mediated by a fall of pHi of CB cells, whereas those to CO2 and extracellular acidity were associated with decreases in pHi.

  2. THE IMPACT OF HYDROGEN SULFIDE (H2S) ON NEUROTRANSMITTER RELEASE FROM THE CAT CAROTID BODY

    PubMed Central

    Fitzgerald, Robert S.; Shirahata, Machiko; Chang, Irene; Kostuk, Eric; Kiihl, Samara

    2011-01-01

    Do cat carotid bodies (CBs) increase their release of acetylcholine and ATP in response to H2S? Two CBs, incubated in a Krebs Ringer bicarbonate solution at 37° C, exhibited a normal response to hypoxia -- increased release of acetylcholine (ACh) and ATP. They were challenged with several concentrations of Na2S, an H2S donor. H2S, a new gasotransmitter, is reported to open KATP channels. Under normoxic conditions the CBs reduced their release of ACh and ATP below control values. They responded identically to pinacidil, a well-known KATP channel opener. CB glomus cells exhibited a positive immunohistochemical signal for cystathione-β-synthetase, a H2S synthesizing enzyme, and for a subunit of the KATP channel. The data suggest that Na2S may have opened the glomus cells’ KATP channels, hyperpolarizing the cells, thus reducing their tonic release of ACh and ATP. Since during hypoxia H2S levels rise, the glomus cells responding very actively to hypoxia may be protected from over-exertion by the H2S opening of the KATP channels. PMID:21292043

  3. Potential role of H2O2 in chemoreception in the cat carotid body.

    PubMed

    Osanai, S; Mokashi, A; Rozanov, C; Buerk, D G; Lahiri, S

    1997-03-19

    The hypothesis that H2O2 plays a critical role in hypoxic chemoreception in the cat carotid body (CB) was tested using a perfused-superfused preparation in vitro, measuring chemosensory discharge and CB tissue PO2 (PtiO2). According to the hypothesis NADPH mediated, PO2 dependent increase in H2O2 production would hyperpolarize the glomus cell, decreasing the chemosensory discharge. Thus, lactate and aminotriazole which would increase H2O2 concentration, would decrease the chemosensory discharge during hypoxia. However, 2.5-5.0 mM lactate and 25 mM aminotriazole did not diminish the hypoxic response. But, 2.5 mM lactate decreased the chemosensory discharge during normoxia which can be explained by an increase of CB PtiO2. Diethyldithiocarbamic acid (5 mM), which blocks the conversion of superoxide to H2O2, also diminished the chemosensory discharge, presumably due to an increased CB PtiO2. Menadione (increasing H2O2) and t-butyl hydroperoxide irreversibly decreased the chemosensory discharge, and the data are not useful. H2O2 increased the PO2 of the perfusate, and therefore could not be tested against PO2. Thus, perturbation of endogenous or exogenous H2O2 did not provide any evidence for its critical role in O2 chemoreception.

  4. Testing the metabolic hypothesis of O2 chemoreception in the cat carotid body in vitro.

    PubMed

    Buerk, D G; Iturriaga, R; Lahiri, S

    1994-03-01

    It is known that oligomycin reduces the oxidative phosphorylation high-energy state or high-energy intermediates by inhibiting the formation of ATP without directly inhibiting electron transport, whereas metabolic uncouplers dissipate the high-energy state without net production of ATP. The metabolic hypothesis for O2 chemoreception in the carotid body (CB) predicts that 1) oligomycin should diminish O2 consumption and attenuate O2 chemoreception and 2) uncouplers should reverse the effect of oligomycin by increasing O2 consumption without restoring O2 chemoreception. These predictions were tested by simultaneously measuring CB chemosensory discharge from the sinus nerve and the rate of tissue O2 disappearance (dPO2/dt) during interruption of perfusate flow in perfused-superfused cat CB preparations (n = 9). O2 consumption was calculated from dPO2/dt. Flow-interruption responses were measured before and after oligomycin (1-microgram bolus) and subsequently after dinitrophenol (50 microM). Chemosensory responses to bolus injections of hypercapnic Tyrode solution, cyanide, or nicotine were also tested periodically. Oligomycin diminished dPO2/dt from -2.67 +/- 0.30 to -2.02 +/- 0.19 (SE) Torr/s (P < 0.004, paired t test) and reduced the maximal sensory response from 196 +/- 43 to 124 +/- 12 impulses/s (P < 0.002, paired t test) while augmenting the initial response to CO2. Dinitrophenol reversed the metabolic depressant effect of oligomycin but further suppressed the chemosensory response. These results confirm the above predictions and strengthen the metabolic hypothesis for O2 chemoreception in the CB.

  5. Neural responses of the cat carotid and aortic bodies to hypercapnia and hypoxia.

    PubMed

    Fitzgerald, R S; Dehghani, G A

    1982-03-01

    The response (imp . s-1) of single- or few-fiber preparations from the carotid body (10 experiments) and the aortic body (5 experiments) to various levels of hypercapnia on different backgrounds of hypoxia were analyzed by two statistical techniques--analysis of variance and the Duncan's new multiple-range test. These analyses showed an initial statistically significant increase in the slope of the response to increasing arterial pressure of CO2 (PaCO2) as PaO2 fell. But the slope of the response to carbon dioxide later showed a clear tendency to become less; i.e., no significant increase in imp . s-1 when a PaCO2 rose (substantially) with normoxic (carotid body) and hypoxic (carotid and aortic bodies) backgrounds. The response of the aortic body to hypercapnia showed no statistically significant increase if the background was hyperoxia or normoxia. The characteristic of the chemoreceptor to become saturated in its response to carbon dioxide while still retaining its ability to respond to hypoxia suggests the possibility that at least some of the mechanisms involved in the chemoreception of hypoxia differ from those involved in the chemoreception of hypercapnia.

  6. Dopamine increases in cat carotid body during excitation by carbon monoxide: implications for a chromophore theory of chemoreception.

    PubMed

    Buerk, D G; Chugh, D K; Osanai, S; Mokashi, A; Lahiri, S

    1997-12-11

    Studies of dopamine (DA) release were conducted with 10 perfused/superfused cat carotid bodies using shallow recessed Nafion polymer-coated microsensors (tips approximately 5 microns). Simultaneous measurements of tissue DA and neuronal discharge (ND) from the sinus nerve were made after switching from normoxic, normocapnic control perfusate (20% O2, 5% CO2, balance N2) to a normoxic, normocapnic perfusate equilibrated with a high tension (> 550 Torr) of carbon monoxide (CO). When high PCO perfusate was delivered in the dark, ND increased from a baseline of 89 +/- 24 (SE) impulses/s, to a peak excitation of 374 +/- 44 impulses/s within 15-30 s. Excitation then diminished to a plateau of 281 +/- 36 impulses/s within 1-2 min. Both peak and plateau ND were significantly above baseline (P < 0.05). Average tissue DA values increased above basal levels by +7.2 +/- 1.0 and +5.6 +/- 0.6 microns, respectively, during the peak and plateau ND phases (P < 0.05). Bright light restored the chemosensory activity to baseline, but had no effect on DA. Both chemosensory excitation and tissue DA responses to high CO in the dark were diminished in 3 carotid bodies perfused with Ca(2+)-free solutions. Responses were reduced even further with Ca2+ chelator (EGTA) in the perfusate. The results suggest that the effect of high PCO on DA release and chemosensory excitation are dependent on Ca2+ in the media, but the two events are not coupled.

  7. Effects of changes in chemoreceptor activity on extracellular K+ and Ca2+ activities in the cat carotid body.

    PubMed

    O'Regan, R G; Acker, H

    1988-04-05

    In anaesthetized, paralysed and artificially ventilated cats triple-barrelled ion-selective microelectrodes (ISMs) were inserted into the right carotid body in order to measure extracellular activities of K+ ([K+]o) and Ca2+ ([Ca2+]o) simultaneously. In 3 experiments a method involving iron deposition located the tips of the ISMs in the cellular islands of the organ. A thin cannula inserted into the right carotid artery (i.c.) via the lingual artery was used to infuse Ringer-Locke solutions (0.1-0.5 ml/min) containing either sodium cyanide (NaCN), acetylcholine (ACh) or dopamine (DA). Analysis of the effects of administration of NaCN (20-100 micrograms/min i.c.) showed that during this procedure [K+]o increased and [Ca2+]o decreased by mean values (+/- S.D.) of 0.99 +/- 0.82 and 0.22 +/- 0.06 mM respectively. During administration of ACh (20-50 micrograms/min i.c.) [K+]o increased and [Ca2+]o decreased respectively by mean values (+/- S.D.) of 3.18 +/- 3.0 and 0.31 +/- 0.14 mM. Decreases in [K+]o and [Ca2+]o by mean values (+/- S.D.) of 1.53 +/- 1.64 and 0.34 +/- 0.33 mM respectively were associated with administration of DA (20-50 micrograms/min i.c.). The predominant influences exerted by NaCN and ACh on chemoreceptor activity were excitatory whereas administration of DA caused either inhibition, excitation or a combination of these two effects. Stimulation of the sympathetic supply to the carotid body was associated with either increases, decreases or no reaction of chemosensory activity, [K+]o and [Ca2+]o. The changes in [K+]o associated with the various procedures may reflect the state of polarization within the chemoreceptor complex. Decreases in [Ca2+]o usually accompanied the performance of all procedures and may have resulted from an increased influx of this ion from the interstitial fluids into the cells for the purpose of provoking neurotransmitter release. However, the time course of the changes in [K+]o and [Ca2+]o were considerably slower in onset and

  8. Adrenergic mechanisms and chemoreception in the carotid body of the cat and rabbit.

    PubMed

    Folgering, H; Ponte, J; Sadig, T

    1982-04-01

    1. The effect of beta-adrenergic and dopaminergic agonists and antagonists on the chemoreceptor response to graded hypoxia and hypercapnia was tested in nineteen cats and ten rabbits anaesthetized either with chloralose-urethane or pentobarbitone sodium, paralysed with pancuronium bromide and artificially ventilated.2. The inhibitory action of dopamine was confirmed. The inhibition following intra-arterial bolus injection was blocked by haloperidol; dopamine then excited and this excitation was blocked with propranolol. Adrenaline or noradrenaline caused a transient inhibition followed by a marked excitation. The inhibition was blocked with haloperidol and the excitation blocked with propranolol or metoprolol. Isoprenaline excited without inhibition and this was blocked with propranolol or metoprolol.3. A novel finding was that the chemoreceptor response to hypoxia was markedly reduced or even abolished with propranolol or metoprolol. The response was enhanced with a constant infusion of isoprenaline, adrenaline or noradrenaline in proportion to the degree of hypoxia, an effect mimicked by raising CO(2). The chemoreceptor response to hypoxia was similarly enhanced by haloperidol and depressed by a constant infusion of dopamine in proportion to the degree of hypoxia.4. The effect of these drugs on the chemoreceptor response to hypercapnia was less constant. In the majority of tests the aminergic agonists and antagonists caused a parallel shift of the CO(2) response curves in the same direction as the O(2) response curves and by amounts proportional to the degree of hypoxia. In some tests these drugs caused a change in the slope of the CO(2) response curves but only if P(a, O2) was less than 60 mmHg.5. One interpretation of these results is that hypoxia exerts a presynaptic action, causing the release of noradrenaline and dopamine from Type I cells, and that these substances act upon aminergic receptors on the sensory fibre, causing a change in potential and

  9. G proteins in carotid body chemoreception.

    PubMed

    Prabhakar, N R; Kou, Y R; Kumar, G K

    1995-01-01

    G proteins are signal coupling molecules that play major roles in mediating the effects of transmitters as well as certain sensory signals. In the present study we examined whether oxygen chemoreception in the carotid body is coupled to G proteins. Experiments were performed on carotid bodies isolated from anesthetized cats. Presence of G proteins was examined with ADP-ribosylation of the carotid body membranes. Pertussis toxin (PTX), which inactivates G proteins in neuronal tissues, ADP-ribosylated a single band of carotid body protein with a molecular mass of 41 kDa. With cholera toxin (CTX) only a faint band of protein corresponding to approximately 45 kDa was evident. Perfusing the isolated carotid bodies with PTX (2.5 micrograms/min; 60 min) attenuated the sensory response to hypoxia by 52% of the controls. Perfusion with CTX (50 micrograms/min; for 60 min), on the other hand, increased baseline activity and potentiated the hypoxic response by 125% of controls. Heat-inactivated toxins, however, had no influence on the carotid body sensory response to hypoxia. These results suggest that G proteins are present in the chemoreceptor tissue and they seem to be coupled to the transduction and/or to the transmission of the hypoxic stimulus.

  10. Acetate enhances the chemosensory response to hypoxia in the cat carotid body in vitro in the absence of CO2-HCO3-.

    PubMed

    Iturriaga, R

    1996-01-01

    To determine if intracellular acidosis enhances hypoxic chemoreception in the absence of CO2-HCO3- at pH 7.4, the effects of sodium acetate (30 mM) were studied on the chemosensory responses of the cat carotid body to hypoxic, stagnant and cytotoxic hypoxia. Carotid bodies were perfused and superfused in vitro with Tyrode's solution, free of CO2-HCO3-, buffered with HEPES-NaOH, pH 7.40, at 36.5 +/d- 0.5 degrees C and equilibrated at PO2 of 125 Torr (perfusate) and < 20 Torr (superfusate). In the absence of acetate, hypoxia (PO2 25 Torr), flow interruption and NaCN (0.01-100 micrograms) augmented the chemosensory discharges. However, in the presence of acetate, the half-excitation time of these responses decreased and their amplitude increased. Thus, acetate enhances the chemosensory response to hypoxic, stagnant and cytotoxic hypoxia. It is suggested that that intracellular acidosis induced by acetate contributes to this potentiation by correcting the alkaline pHi caused by the absence of HCO3-(-)HCO2 in the perfusate.

  11. Reciprocal photolabile O2 consumption and chemoreceptor excitation by carbon monoxide in the cat carotid body: evidence for cytochrome a3 as the primary O2 sensor.

    PubMed

    Lahiri, S; Buerk, D G; Chugh, D; Osanai, S; Mokashi, A

    1995-07-03

    High carbon monoxide (CO) gas tensions (> 500 Torr) at normoxic PO2 (125-140 Torr) stimulates carotid chemosensory discharge in the perfused carotid body (CB) in the absence but not in the presence of light. According to a metabolic hypothesis of O2 chemoreception, the increased chemosensory discharge should correspond to a photoreversible decrease of O2 consumption, unlike a non-respiratory hypothesis. We tested the respiratory vs. non-respiratory hypotheses of O2 chemoreception in the cat CB by measuring the effect of high CO. Experiments were conducted using CBs perfused and superfused in vitro with high CO in normoxic, normocapnic cell-free CO2-HCO3- buffer solution at 37 degrees C. Simultaneous measurements of the rate of O2 disappearance with recessed PO2 microelectrodes and chemosensory discharge were made after flow interruption with and without CO in the perfusate. The control O2 disappearance rate without CO was -3.66 +/- 0.43 (S.E.) Torr/s (100 measurements in 12 cat CBs). In the dark, high CO reduced the O2 disappearance rate to -2.35 +/- 0.33 Torr/s, or 64.2 +/- 9.0% of control (P < 0.005, 34 measurements). High CO was excitatory in the dark, with an increase in baseline neural discharge from 129.2 +/- 47.0 to 399.3 +/- 49.1 impulses per s (P < 0.0001), and maximum discharge rate of 659 +/- 76 impulses/s (N.S. compared to control) during flow interruption. During perfusion with high CO in the light, there were no significant differences in baseline neural discharge or in the maximum neural discharge after flow interruption, and little effect on O2 metabolism (88.8 +/- 11.5% of control, N.S., 29 measurements).(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Carbon monoxide: a role in carotid body chemoreception.

    PubMed

    Prabhakar, N R; Dinerman, J L; Agani, F H; Snyder, S H

    1995-03-14

    Carbon monoxide (CO), produced endogenously by heme oxygenase, has been implicated as a neuronal messenger. Carotid bodies are sensory organs that regulate ventilation by responding to alterations of blood oxygen, CO2, and pH. Changes in blood gases are sensed by glomus cells in the carotid body that synapse on afferent terminals of the carotid sinus nerve that projects to respiratory-related neurons in the brainstem. Using immunocytochemistry, we demonstrate that heme oxygenase 2 is localized to glomus cells in the cat and rat carotid bodies. Physiological studies show that zinc protoporphyrin IX, a potent heme oxygenase inhibitor, markedly increases carotid body sensory activity, while copper protoporphyrin IX, which does not inhibit the enzyme, is inactive. Exogenous CO reverses the stimulatory effects of zinc protoporphyrin IX. These results suggest that glomus cells are capable of synthesizing CO and endogenous CO appears to be a physiologic regulator of carotid body sensory activity.

  13. Carotid and Vagal Body Paragangliomas

    PubMed Central

    del Guercio, Luca; Narese, Donatella; Ferrara, Doriana; Butrico, Lucia; Padricelli, Andrea; Porcellini, Massimo

    Between 1972 and 2012, 25 patients presenting 32 paragangliomas of the neck were observed. Tumor locations included the carotid body (CBTs) in 21 patients and the vagus nerve in 4. Four patients had bilateral CBT and one a bilateral vagal tumor; a metachronous bilateral jugulare paraganglioma was diagnosed in one patient with bilateral CBT Shamblin type III. Five patients presented CBTs type II and three type III. Preoperative embolization was performed in 5 CBTs, with no significant difference in blood loss. Twenty-nine paragangliomas were resected (with three internal carotid artery resection): there were no cerebrovascular accident or perioperative death. Nine patients (36%) had cranial nerve palsy prior to surgery and a postoperative nerve dysfunction occurred in four other tumors (16%). Persistent nerve deficits occurred in 3 patients (12%). No evidence of malignancy was shown, intraoperatively or during a postoperative follow-up period (9 months to 18 years; mean: 8 years). PMID:24251239

  14. Carotid body disease and the physician--chronic carotid glomitis.

    PubMed Central

    Heath, D.; Khan, Q.; Nash, J.; Smith, P.

    1989-01-01

    There are three types of histological change in the carotid bodies which appear to have physiological and clinical associations. A prominence of the dark variant of chief cells with their contents of met-enkephalin and other peptides appears to be associated with acute exposure to hypoxia. Proliferation of sustentacular cells around the clusters of chief cells appears to be related to ageing and also to systemic hypertension. Recently we have described a new condition of chronic carotid glomitis which is characterized by follicles of lymphocytes and may have a basis in auto-immunity. In the present review we report for the first time plasma cell activity in the carotid bodies of an elderly man, especially around nerve fibrils and unmyelinated axons ensheathed in sustentacular cells. Such appearances are consistent with the view that ageing nerve fibrils may be the antigenic stimulus for the development of chronic carotid glomitis. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:2692011

  15. Myocardial hypertrophy induces carotid body hyperplasia.

    PubMed

    Sivridis, Efthimios; Pavlidis, Pavlos; Fiska, Aliki; Pitsiava, Dimitra; Giatromanolaki, Alexandra

    2011-01-01

    The carotid bodies tend to enlarge after long-standing cardiopulmonary disease. Our objective was to investigate whether cardiac hypertrophy is associated with carotid body hyperplasia. Fifteen autopsy cases with combined left and right ventricular hypertrophy were examined and compared with two control groups (16 cases). The study involved a meticulous dissection of carotid bifurcations, thin serial sections, and morphometric analysis of carotid body volume and cell types (progenitor, dark, light, and sustentacular). There was a significant increase in sustentacular cells in all individuals with cardiac hypertrophy, which was not drug-induced, and accompanied by a similar increase in carotid body volume. Dark or light cell accumulation was detected focally and only in three instances. It appears that the generalized sustentacular cell hyperplasia is the result of long-standing hypoxia, while a superimposed focal prominence of dark or light cells may be proliferative or metaplastic in nature and attributed to short-term hypoxia.

  16. Selective activation of carotid nerve fibers by acetylcholine applied to the cat petrosal ganglion in vitro.

    PubMed

    Alcayaga, J; Iturriaga, R; Varas, R; Arroyo, J; Zapata, P

    1998-03-09

    The petrosal ganglion innervates carotid body chemoreceptors through the carotid (sinus) nerve. These primary sensory neurons are activated by transmitters released from receptor (glomus) cells, acetylcholine (ACh) having been proposed as one of the transmitters involved in this process. Since the perikarya of primary sensory neurons share several properties with peripheral sensory endings, we studied the electrical responses of the carotid nerve and glossopharyngeal branch to ACh locally applied to the cat petrosal ganglion superfused in vitro. Ganglionar applications of AChCl (1 microg-1 mg) generated bursts of action potentials conducted along the carotid nerve, while only a few spikes were exceptionally recorded from the glossopharyngeal branch in response to the largest doses. Carotid nerve responses to ACh were dose-dependent, the higher doses inducing transient desensitization. Application of nicotine to the petrosal ganglion also evoked dose-dependent excitatory responses in the carotid nerve. Responses to ACh were reversibly antagonized by adding hexamethonium to the superfusate, more intense and prolonged block of ACh responses being produced by mecamylamine. Ganglionar applications of gamma-amino butyric acid and serotonin, in doses of up to 5 mg, did not induce firing of action potentials in any of the branches of the glossopharyngeal nerve. Our results indicate that petrosal ganglion neurons projecting through the carotid nerve are selectively activated by ACh acting on nicotinic ACh receptors located in the somata of these neurons. Thus, cholinosensitivity would be shared by the membranes of peripheral endings and perikarya of primary sensory neurons involved in arterial chemoreception.

  17. Anatomical variations in human carotid bodies.

    PubMed Central

    Khan, Q; Heath, D; Smith, P

    1988-01-01

    The variations in anatomical structure and position of both carotid bodies were noted in 100 consecutive subjects who came to necropsy. Considerable variations in form were found. Although most carotid bodies (83% on the right and 86% on the left) were of the classic ovoid type, an appreciable minority was bilobed (9% on the right and 7% on the left) or double (7% on the right and 6% on the left); 1% were leaf shaped. All these anatomical variants have to be distinguished from the pathologically enlarged carotid body that may have a smooth or finely nodular surface. Anatomical variants (such as the bilobed) may themselves enlarge as a consequence of carotid body hyperplasia. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 6 Fig 7 Fig 8 PMID:3209707

  18. Hyperbaric oxygenation alters carotid body ultrastructure and function.

    PubMed

    Torbati, D; Sherpa, A K; Lahiri, S; Mokashi, A; Albertine, K H; DiGiulio, C

    1993-05-01

    We previously demonstrated that chronic normobaric hyperoxia (NH) for 60-67 h attenuated the carotid chemosensory response to hypoxia, probably initiated by the generation of reactive oxygen species (ROS). Since biological systems are affected by oxygen in a dose-dependent manner, we hypothesized that hyperbaric oxygenation (HBO) would affect the cellular mechanisms of oxygen chemoreception in a shorter time. To test the hypothesis, we studied the effects of oxygen at 5 atmospheres absolute (ATA) on cats (n = 7) carotid body ultrastructure and chemosensory responses to hypoxia, hypercapnia, and to bolus injections of cyanide, nicotine and dopamine. Four control cats breathed room air at 1 ATA. At the termination of the experiments, carotid bodies from 4 cats in each group were fixed and prepared for electron microscopy and morphometry. On the average, HBO diminished the chemosensory responsiveness to hypoxia (P < 0.01, unpaired t-test) within about 2 h, supporting the hypothesis. The responses to hypercapnia or bolus injections of cyanide, nicotine and dopamine were normal. HBO did not diminish the distribution of the dense-cored vesicles but significantly increased the mean volume-density of mitochondria and decreased the cristated area per mitochondrion in the glomus cells. The latter suggests a link between oxidative metabolism and chemosensing, and the former excludes availability of neurotransmitters being the cause of the blunted chemosensory response to hypoxia.

  19. Analysis of carotid chemoreceptor responses to substance P analogue in anaesthetized cats.

    PubMed

    Prabhakar, N R; Gouda, E; Kumar, G K; Kou, Y R

    1995-03-18

    Analogues of Substance P (SP) have been shown to act as SP receptor antagonists in various physiological systems. We have previously shown that the carotid body sensory response to hypoxia could be attenuated by D-Pro2-D-Trp7,9-SP (DPDT-SP) and suggested that SP may be important for chemoreception. In the absence of detailed characterization of the antagonistic effects of DPDT-SP, the role of SP in carotid body chemoreception remains uncertain. The present study was undertaken to analyze the effects of DPDT-SP on carotid body activity in anaesthetized cats (n = 18). Intra-carotid infusion of DPDT-SP antagonized SP-induced chemoreceptor stimulation. 90% blockade of SP responses was obtained at infusion rates of 15 micrograms/kg per min of DPDT-SP for 15 min. By contrast, infusions of either saline (controls) or at doses below 10 micrograms/kg per min had no effect on SP responses. The doses that effectively antagonized SP excitation (i.e., 15 micrograms/kg per min) also blocked or markedly attenuated the chemoreceptor responses to hypoxia, without affecting the carotid body stimulation caused by nicotine. The effects of DPDT-SP were associated with significant reduction in baseline activity in normoxia. The antagonistic effects were reversible after terminating the infusion of DPDT-SP. Increasing the dose to 25 micrograms/kg per min, however, abolished the carotid body excitation by any of the stimuli tested (i.e., SP, hypoxia and nicotine), indicating that at higher doses DPDT-SP is non-selective. These results demonstrate that DPDT-SP given in adequate doses to block SP response also attenuates or abolishes the carotid body excitation by hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Dopamine modulates carotid nerve responses induced by acetylcholine on the cat petrosal ganglion in vitro.

    PubMed

    Alcayaga, J; Varas, R; Arroyo, J; Iturriaga, R; Zapata, P

    1999-06-12

    We have recently reported that application of acetylcholine (ACh) or nicotine to the petrosal ganglion-the sensory ganglion of the glossopharyngeal nerve-elicits a burst of discharges in the carotid nerve branch, innervating the carotid body and sinus, but not in the glossopharyngeal branch, innervating the tongue and pharynx. Thus, the perikarya of sensory neurons for the carotid bifurcation exhibit selective cholinosensitivity. Since dopamine (DA) modulates carotid nerve chemosensory activity, we searched for the presence of DA sensitivity at the perikarya of these neurons in the cat petrosal ganglion superfused in vitro. Applications of DA in doses of up to 5 mg to the ganglion did not modify the rate of spontaneous discharges in the carotid nerve. However, if DA was applied 30 s before ACh injections, ACh-evoked reactions were modified: low doses of DA enhanced the subsequent responses to ACh, while high doses of DA depressed the responses to ACh. This depressant effect of DA on ACh responses was partially antagonized by adding spiroperone to the superfusate. Our results show that the response to ACh of petrosal ganglion neurons projecting through the carotid nerve is modulated by DA acting on D(2) receptors located in the somata of these neurons. Thus, dopaminergic modulation of cholinosensitivity could be shared also by the membranes of peripheral endings and perikarya of primary sensory neurons involved in arterial chemoreception.

  1. Neurotransmission in the carotid body: transmitters and modulators between glomus cells and petrosal ganglion nerve terminals.

    PubMed

    Iturriaga, Rodrigo; Alcayaga, Julio

    2004-12-01

    The carotid body (CB) is the main arterial chemoreceptor. The most accepted model of arterial chemoreception postulates that carotid body glomus (type I) cells are the primary receptors, which are synaptically connected to the nerve terminals of petrosal ganglion (PG) neurons. In response to natural stimuli, glomus cells are expected to release one (or more) transmitter(s) which, acting on the peripheral nerve terminals of processes from chemosensory petrosal neurons, increases the sensory discharge. Among several molecules present in glomus cells, acetylcholine and adenosine nucleotides and dopamine are considered as excitatory transmitter candidates. In this review, we will examine recent evidence supporting the notion that acetylcholine and adenosine 5'-triphosphate are the main excitatory transmitters in the cat and rat carotid bodies. On the other hand, dopamine may act as a modulator of the chemoreception process in the cat, but as an excitatory transmitter in the rabbit carotid body.

  2. Body CT (CAT Scan)

    MedlinePlus

    ... may increase the risk of an unusual adverse effect. Women should always inform their physician and the CT ... of data to create two-dimensional cross-sectional images of your body, which are then displayed on a monitor. CT ...

  3. Protein kinase C--a potential modifier of carotid body function.

    PubMed

    Faff, L; Kowalewski, C; Pokorski, M

    1999-04-01

    This article deals with the potential role of protein kinase C (PKC) in signal transduction in the carotid body. The carotid body is a chemosensory organ which, by sensing reductions in arterial blood oxygen tension, is primarily responsible for the hyperventilation of hypoxia. The mechanisms of transduction of the hypoxic stimulus into a neural signal regulating respiration are not clear. Hypoxia increases the phosphoinositide-specific phospholipase C (PLC) activity in the carotid body. The PLC-derived signalling molecules are known to activate PKC. The enzyme might, thus, have the potential to interact with the process of chemoreception. This article demonstrates that PKC is present in the chemoreceptor cells of the cat carotid body and discusses the biology of the enzyme relevant to chemosensory function. This gives rise to the hypothesis that PKC-mediated mechanisms alter chemoreceptor cell function to a sufficient extent to metamorphose the hypoxic signal into an increased discharge frequency in the apposed sinus nerve endings.

  4. Amiloride and carotid body chemoreception of hypercapnia and hypoxia.

    PubMed

    Fitzgerald, R S; Shirahata, M; Lahiri, S

    1990-09-01

    The sodium-proton (Na(+)-H+) antiporter has been found in virtually every tissue where its presence has been investigated. Its principal physiological role is to regulate intracellular pH (pHi). Amiloride (10(-3)-10(-4) M) is a known blocker of the antiporter when Na is present in normal physiological concentrations (130-140 x 10(-3) M). In order to determine if the Na(+)-H+ antiporter participated in the chemoreception of hypercapnia or hypoxia anesthetized, paralyzed, artificially ventilated cats were fitted with a loop in the right common carotid artery for the selective perfusion of the carotid body. Neural activity (imp/10 sec) was recorded from single or few fiber preparations during hypercapnia (PaCO2 = 48-64 Torr) while the carotid body was perfused with Krebs-Ringer bicarbonate solution for 2.5 min, then with its own hypercapnic arterial blood (4 min), then with Krebs-Ringer bicarbonate solution containing 0.6-0.8 x 10(-3) M amiloride (2.5 min), then with its own hypercapnic blood (4 min). After 20 min of rest the protocol was repeated during hypoxia (PaO2 = 35-45 Torr). The carotid body response to hypercapnic blood was unaffected by a preceding perfusion of the amiloride-containing solution but the response to hypoxic blood was decreased by 25% by the amiloride-containing solution. The data suggest the possibility of different mechanisms being involved in the chemoreception of hypercapnia and hypoxia.

  5. Two cytochrome oxygen consumption model and mechanism for carotid body chemoreception.

    PubMed

    Nair, P K; Buerk, D G; Whalen, W J; Schubert, R W

    1986-01-01

    We have measured sinus nerve discharge, tissue PO2 and oxygen consumption (VO2) in cat carotid bodies under different experimental conditions using our recessed oxygen microelectrode. Our results indicate that the change in chemoreceptor activity with oxygen disappearance following blood flow occlusion can be related to a two cytochrome model for oxygen consumption as previously proposed by Mills and Jöbsis (1972).

  6. Effect of acute and chronic cobalt administration on carotid body chemoreceptors responses.

    PubMed

    Morelli, L; Di Giulio, C; Iezzi, M; Data, P G

    1994-06-30

    Chronic cobalt exposure leads to release and production of erythropoietin and consequently to polycythemia. Accordingly, cellular elements sensitive to oxygen in the carotid body, would manifest responses during acute and chronic cobalt administration. The carotid body, detects gas changes (PO2, PCO2/pH) in the arterial blood and regulates ventilation and circulation by the afferent nerve discharge. We hypothesized that cobalt interacts with an oxygen sensitive mechanism in the carotid chemoreception and in erythropoietin producing cells. Twelve cats were anesthetized, paralysed and artificially ventilated; few fiber preparation of carotid sinus nerve were recorded during close intraarterial injection of cobalt. In another protocol, 12 rats received an intraperitoneal dose of CoCl2 (10 mg/kg) daily for 6 weeks. At the end, the carotid body was fixed in situ by superfusion. Ultrastructural and morphometric studies were made. Acute administration (0.08-2.3 mumol) promptly stimulated the chemoreceptor afferents. Type I cells increased significantly along with erythropoiesis in the chronic cobalt treated rats. The stimulatory effects of cobalt on the carotid body chemoreceptor showed that sensitive mechanisms in the kidney and in the carotid body are similar, and cobalt interacts with the physiological responses of oxygen.

  7. Carotid body O2 chemoreception and mitochondrial oxidative phosphorylation.

    PubMed

    Mulligan, E; Lahiri, S; Storey, B T

    1981-08-01

    The effect on carotid chemoreceptor afferents of oligomycin, an inhibitor of mitochondrial oxidative phosphorylation that does not affect energy conservation, was studied in 20 cats that were anesthetized, paralyzed, and artificially ventilated. Responses of single or a few chemoreceptor afferents to changes in arterial O2 tension (PaO2) at constant arterial CO2 tension were recorded. In addition, responses to nicotine, cyanide, and antimycin A or carbonyl cyanide p-tri-fluoromethoxyphenylhydrazone (FCCP) were tested in normoxia. Oligomycin (50-500 microgram) was administered by close intra-arterial injection, and the same tests were repeated at timed intervals. Initially, oligomycin caused vigorous stimulation of carotid chemoreceptor activity. Subsequently, although the afferent fibers were still active and could be vigorously stimulated by nicotine, they no longer responded to changes in PaO2 or to doses of cyanide, antimycin A, or FCCP. These results separate stimulation of chemoreceptor afferents by hypoxia and metabolic inhibitors and uncouplers from that by nicotine and suggest that intact oxidative phosphorylation, required for maintenance of the intracellular high-energy phosphate levels, forms the basis of O2 chemoreception in the carotid body.

  8. Differential effects of oligomycin on carotid chemoreceptor responses to O2 and CO2 in the cat.

    PubMed

    Shirahata, M; Andronikou, S; Lahiri, S

    1987-11-01

    Effects of oligomycin on carotid chemoreceptor responses to O2 and CO2 were investigated using an in situ perfusion technique. Cats were anesthetized, paralyzed, and artificially ventilated. To avoid a possible reaction between an oligomycin-ethanol mixture and blood, we administered oligomycin to the carotid body via cell- and protein-free perfusate. Except for the perfusion periods, the carotid body received its own natural blood supply. Responses to O2, CO2, sodium cyanide, and nicotine of the same carotid chemoreceptor afferents were studied before and after each perfusion. An appropriate low dose of oligomycin completely blocked carotid chemoreceptor response to O2 while preserving the CO2 response. At the same time cyanide response was attenuated leaving nicotine response intact. Additional doses of oligomycin attenuated carotid chemoreceptor response to CO2 as well. Perfusion with a blank solution containing ethanol did not change the carotid body chemoreceptor responses. These effects of oligomycin on carotid chemoreceptor responses to O2 and CO2 were reversible, and restoration of the response to CO2 preceded that to O2. In addition, oligomycin administered into the blood with close intra-arterial injection produced similar differential blockade of O2 and CO2 chemoreception, preserving the nicotine and dopamine effects. This study confirmed the previous findings and provided new evidence showing that 1) the responses of carotid chemoreceptor to O2 and CO2 were separable by oligomycin due to the inhibition of oxidative phosphorylation and 2) the responses to nicotine and dopamine were intact even after blockade of O2 response.

  9. CO interact with intracellular [H+] with and without CO2-HCO3- in the cat carotid chemosensory discharge.

    PubMed

    Osanai, S; Rozanov, C; Mokashi, A; Buerk, D G; Lahiri, S

    1997-08-01

    To test the hypothesis whether CO2-HCO3- buffer is essential for the expression of chemoreception and to distinguish between pHi and pHo interaction with pCO in the carotid chemosensory response, we superfused-perfused in vitro cat carotid bodies using HEPES-Tyrode's solution with and without CO2-HCO3-, and compared the responses at the same pHo in the absence and presence of light. In the absence of light, pCO (> 138 Torr) stimulated the carotid body chemoreceptors in CO2-HCO3- buffer at pHo of 7.40, whereas pCO (69-550 Torr) did not stimulate the neural discharge in HEPES buffer at the pHo of 7.4-7.1 but did so below pHo 7.1. In the presence of light, all the responses were diminished proportionately.

  10. Stimulus interaction between CO2 and almitrine in the cat carotid chemoreceptors.

    PubMed

    Lahiri, S; Mokashi, A; Huang, W; Sherpa, A K; Di Giulio, C

    1989-07-01

    The hypothesis that augmentation of the carotid chemoreceptor response to hypoxia by almitrine is due in part to an increased response to CO2 was tested by using single or few fiber preparation of carotid body chemosensory fibers in 12 cats anesthetized with alpha-chloralose. To differentiate between the plausible mechanisms of effects, we also tested the responsiveness of the afferents to cyanide and nicotine before and after almitrine. After a saturation dose of almitrine (1 mg.kg-1 followed by 0.5 mg.kg-1.h-1) the chemosensory responses to CO2 strikingly increased even during hyperoxia: the afferents showing an increased transient peak activity at the onset of hypercapnia, an augmented steady-state response to CO2 stimulus, and a decreased arterial PCO2 stimulus threshold. Thus, the effect of almitrine on carotid chemoreceptor response to hypoxia could be explained, at least in part, by its multiplicative stimulus interaction with CO2. After almitrine, the chemoreceptor response to cyanide, which is dependent on arterial PO2, was not particularly augmented relative to those of nicotine. Accordingly, the O2-sensing mechanism does not appear to be the primary site of almitrine effect. The results also indicate that the site of CO2 chemoreception resides downstream from those of hypoxia.

  11. 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.

  12. Interaction of dopamine and haloperidol with O2 and CO2 chemoreception in carotid body.

    PubMed

    Lahiri, S; Nishino, T; Mokashi, A; Mulligan, E

    1980-07-01

    Effects of dopamine and of a dopaminergic blocker, haloperidol, on the responses of carotid body chemoreceptors to hypoxia and hypercapnia were investigated in 16 anesthetized cats. Intravenous infusion of dopamine (10-20 micrograms.min-1) decreased carotid body chemoreceptor responses to hypoxia and hypercapnia. The effect was greater at higher levels of arterial oxygen and carbon dioxide tension (PaO2 and PaCO2) stimulus. Thus, the magnitude of the dopamine effect depended on the degree of both PO2- and PCO2-mediated excitation of the receptors. Haloperidol potentiated responses to both hypoxia and hypercapnia but apparently did not stimulate the receptors in the absence of these stimuli. Potentiation by haloperidol and inhibition by dopamine of excitatory effects due to PaO2 decrease and PaCO2 increase are complementary. The data suggest that chemoreception of dopamine, O2, and CO2 converge at some site in the carotid body. Persistence of hypoxic and hypercapnic responses, following dopamine-blocking doses of haloperidol, does not support the theory that regulation of dopamine release is responsible for O2 and CO2 chemoreception in carotid body of the cat.

  13. 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

  14. Anesthetic approaches in carotid body tumor surgery

    PubMed Central

    Kavakli, Ali Sait; Ozturk, Nilgun Kavrut

    2016-01-01

    OBJECTIVE: Carotid body tumors (CBT) are benign tumors that originate from neural non-chromaffin cells that are typically localized near carotid bifurcation. Surgical removal of the tumor is the most appropriate treatment. General anesthesia is preferred anesthetic technique for CBT surgery. Basic elements of anesthetic management are protection of hemodynamic stability and maintaining cerebral perfusion pressure (CPP). The aim of this study was to evaluate anesthetic management of CBT surgery and present the literature knowledge. METHODS: The study included 10 consecutive patients with diagnosis of CBT who underwent surgery at Antalya Training and Research Hospital, in Antalya, Turkey, between 2013 and 2016. Preoperative demographic details; comorbidities; side of surgical site; duration of operation; length of intensive care unit (ICU) and hospital stay; change of intraoperative blood pressure; use of inotropic drugs, blood products, and analgesics; postoperative visual analogue scale (VAS) pain score; and complications were recorded. RESULTS: According to Shamblin classification, 3 tumors were type I and the remaining 7 were type II. Tumors were located on right side in 6 patients, and on left in 4. Blood loss sufficient to require transfusion was observed in 1 patient. Average intraoperative blood loss was 287±68 mL. Tachycardia and hypertension were observed in 1 patient; bradycardia and hypotension were seen in 4 patients. Infusion for inotropic support was administered to 1 patient. Mean duration of operation was 109±20 minutes. Mean VAS score was 4±1, mean ICU tramadol consumption was 80±25 mg. Duration of stay in ICU and hospital were 2.4±1.1 hours and 3.8±0.7 days, respectively. Mortality and neurological complications were not seen in postoperative period. CONCLUSION: CBT surgery requires close and complex anesthesia management. Protection of hemodynamic stability against sudden hemodynamic changes, monitoring, and maintaining CPP are the most

  15. Selective inhibition of the carotid body sensory response to hypoxia by the substance P receptor antagonist CP-96,345.

    PubMed

    Prabhakar, N R; Cao, H; Lowe, J A; Snider, R M

    1993-11-01

    Carotid bodies are sensory organs for monitoring arterial oxygen and CO2. Previous studies have shown that chemoreceptor tissue contains substance P (SP) and exogenously administered SP augments chemosensory discharge. In the present study, we examined the physiological importance of SP in carotid body chemoreception by using a selective nonpeptide SP [neurokinin (NK) 1] receptor antagonist CP-96,345. In experiments performed on anesthetized cats, sensory discharge was recorded from the carotid body in situ. To control for alterations in blood flow, additional studies were conducted on the carotid body in vitro. In in vivo studies, close carotid body (intraarterial) administration of CP-96,345 attenuated the sensory response to hypoxia in a dose-dependent manner with 73% of the response abolished at doses of 0.3-0.6 mg/kg. Comparable doses of the (2R,3R)-enantiomer had no effect on hypoxia-induced excitation, indicating that the effect of CP-96,345 was not due to nonspecific action. In contrast, the carotid body response to high CO2 was not affected by CP-96,345, implying that only the hypoxic response is mediated by NK-1 receptor and confirming that the effect of the SP antagonist was not due to nonspecific actions. Marked attenuation of the sensory response to hypoxia was also obtained in the carotid body in vitro, suggesting that the effects of the NK-1 antagonist were not secondary to cardiovascular changes. These results demonstrate that CP-96,345 attenuates or abolishes the chemosensory response to hypoxia but not to CO2 and suggest that SP mediates the hypoxia-induced sensory excitation in the cat carotid body via NK-1 receptor activation.

  16. A case of carotid body tumor concomitant with carcinoid tumor.

    PubMed

    Mun, Mi Jin; Lee, Jin Choon; Lee, Byung Joo

    2015-02-01

    Neuroendocrine tumors typically fall into two broad categories: those of epithelial origin and those of neural derivation. The former group includes carcinoid tumors and the latter includes paraganglioma. Although paraganglioma and carcinoid tumor have different biologic behaviors, their overlapping histological appearance can pose diagnostic challenges. Carcinoid tumors are rare, slow-growing neuroendocrine tumors arising from the enterochromaffin cells disseminated throughout the gastrointestinal and bronchopulmonary systems. Carotid body tumor is the most common type of extra-adrenal paraganglioma. Paraganglioma tends to grow slowly but can compress adjacent vessel and nerve. A 63-year-old woman showed huge mass extending from carotid body to skull base, encircling internal and external carotid arteries on magnetic resonance image. Surgical removal of carotid body tumor was done after embolization procedure. Postoperative histopathologic examination and immunohistochemical analysis were consistent with paraganglioma concomitant with carcinoid tumor in carotid body. Primary cervical carcinoid tumor is extremely rare, and to the best of our knowledge, this is the first case of concomitant existence of paraganglioma and carcinoid tumor in carotid body.

  17. Effect of osmotic stimuli on the carotid baroreceptor and chemoreceptor discharges in cats.

    PubMed

    Trzebski, A; Chruścielewski, L; Majcherczyk, S

    1978-01-01

    In 15 cats under chloralose-urethan anaesthesia carotid sinus area was arterially isolated and perfused with artificially pulsatile pressures. Solutions of NaCl, of various osmolality, mannitol, glucose and bicarbonate were locally perfused through the isolated carotid area and the single baroreceptor and chemoreceptor fibre activity was recorded with standard technique. An increase in the osmolality of the perfused fluid evoked an increase of the single baroreceptor discharge. Each pulse pressure produced more spikes of higher frequency in big A type baroreceptor fibres. Clear effects were observed during perfusion of 300 mM NCl solutions. Solutions of higher osmolility transformed rhythmical pulse pressure discharge into continuous baroreceptor firing. The excitatory effects of hyperosmolar solutions were reversible after switching to the perfusion fluids of normal osmolality. An increased activity was also observed in the single carotid chemoreceptor fibres. It is concluded that both baro- and chemoreceptors are sensitive to osmotic stimulation.

  18. Evidence for histamine as a new modulator of carotid body chemoreception.

    PubMed

    Rio, R Del; Moya, E A; Alcayaga, J; Iturriaga, R

    2009-01-01

    It has been proposed that histamine is an excitatory transmitter between the glomus cells of the carotid body (CB) and the nerve endings of the petrosal ganglion (PG) neurons. The histamine biosynthetic pathway and the presence of histamine H1, H2 and H3 receptors have been reported in the CB. Thus, histamine meets some of the criteria to be regarded as a transmitter. However, there is no evidence that glomus cells contain histamine, or whether its application produces chemosensory excitation. Therefore, we studied its immunocytochemical localization on cat CB and its effects on chemosensory activity. Using perfused and superfused in vitro CB and PG preparations, we assessed the effects of histamine hydrochloride on chemosensory discharges and of histamine H1, H2 and H3 receptor blockers. We found the presence of histamine immunoreactivity in dense-core vesicles in glomus cells. In an in vitro CB preparation we performed pharmacological experiments to characterize histamine effects. The application of histamine hydrochloride (0.5-1,000 microg) to the CB produces a dose-dependent increase in the carotid sinus nerve activity. The H1 receptor blockade with pyrilamine 500 nM produces partial decrease of the histamine-induced response, whereas the H2 receptor blockade (ranitidine 100microM) fail to abolish the histamine excitatory effects. Antagonism of the H3 receptor results in an increase in carotid body chemosensory activity. On the other hand, application of histamine to the isolated PG had no effect on the carotid nerve discharge. Our results suggest that histamine is a modulator of the carotid body chemoreception through H1 and H3 receptor activation.

  19. Gasotransmitter Regulation of Ion Channels: A Key Step in O2 Sensing By the Carotid Body

    PubMed Central

    Prabhakar, Nanduri R.

    2014-01-01

    Carotid bodies detect hypoxia in arterial blood, translating this stimulus into physiological responses via the CNS. It is long established that ion channels are critical to this process. More recent evidence indicates that gasotransmitters exert powerful influences on O2 sensing by the carotid body. Here, we review current understanding of hypoxia-dependent production of gasotransmitters, how they regulate ion channels in the carotid body, and how this impacts carotid body function. PMID:24382871

  20. Chemical modification of carotid body chemoreception by sulfhydryls.

    PubMed

    Lahiri, S

    1981-05-29

    Sulfhydryl reagents cause striking augmentation of the chemoreceptor responses of the carotid body to hypoxia. This indicates that a cellular plasma membrane protein with a reactive sulfhydryl group is a constituent part of the chemoreceptor architecture and provides a means of identification, localization, and isolation of the protein.

  1. 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.

  2. Protein phosphorylation signaling mechanisms in carotid body chemoreception.

    PubMed

    Wang, Z Z; He, L; Chen, J; Dinger, B; Stensaas, L; Fidone, S

    1999-01-01

    Chemotransduction in the carotid body occurs in specialized type I cells and likely involves a complex series of regulated events which culminates in the release of neurotransmitter agents and the excitation of afferent nerve fibers. Previous studies have shown that multiple factors, including the levels of calcium and cyclic nucleotide second messengers, are important regulators of the chemoreceptor transduction cascade in type I cells. In addition, increases in electrical excitability induced in type I cells by chronic exposure to hypoxia are mimicked by agents which elevate intracellular cyclic AMP levels [Stea et al., J Neurosci 1995;15:2192-2202]. These and other findings suggest that protein kinases, and the phosphorylation of specific protein targets are important components of the hypoxic transduction machinery. Moreover, protein kinase-mediated cascades may participate in the well-known physiological adjustments which occur in the carotid body during prolonged stimulation. In the current study, our data demonstrate (1) the presence of specific protein kinases and target phosphoproteins in the carotid body, and also in the morphologically similar small intensely fluorescent cells of the superior cervical sympathetic ganglia. (2) Nitric oxide production and efferent inhibition in the chemosensory tissue is reduced in the presence of the specific tyrosine kinase inhibitor, lavendustin A. (3) Hypoxia-induced catecholamine release from type I cells is inhibited by the protein kinase A antagonist, Rp-cAMPs. And finally (4), exposure to chronic hypoxia up-regulates the expression of the tyrosine kinase, fyn, and an important growth regulatory phosphoprotein, growth associated protein-43 (GAP-43). These findings suggest that second messenger-mediated phosphorylation and dephosphorylation of specific protein targets is a mechanism capable of regulating diverse cellular functions in the carotid body during acute and chronic stimulation.

  3. The histology of the carotid bodies in highlanders from Ladakh

    NASA Astrophysics Data System (ADS)

    Khan, Q.; Heath, D.; Smith, P.; Norboo, T.

    1988-12-01

    A histological study was made of the carotid bodies in a boy and three adult male highlanders born and residing between altitudes of 3300 m to 4200 m in Ladakh. The carotid bodies were enlarged in two of the men, and in all four subjects showed increased numbers and enlargement of the dark variants of the chief cells of the glomic tissue. In these dark cells the cytoplasm was voluminous, formed streamers and contained many intracytoplasmic vesicles of which some had mused to form larger vesicles that appeared to have discharged from the cell surface. Immunohistochemical studies showed that these cells contained considerable amounts of the peptide met-enkephalin. It is thus considered that prominence of dark cells containing this peptide is characteristic of sustained exposure of the carotid bodies to hypobaric hypoxia. In the middle-aged highlander there was a prominence of sustentacular cells which encroached upon the cores of chief cells and this may be associated with the characteristic loss of hypoxic ventilatory response in the highlander.

  4. 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.

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

    PubMed

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

    2014-08-01

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

  6. [Surgical treatment of tumors of the carotid body with reconstruction of the internal carotid artery].

    PubMed

    Reparaz, L; Magallón, P; Riera, L; Capilla, M T; Merino, M J; Martínez, I; Hernández, A; Sáez, L; Alamo, O; Jiménez Cossío, J A

    1990-01-01

    The experience about treatment in infiltrating tumors of Carotid Corpus, III Degree (Shamblin), is presented. Different methods of carotid reconstruction, and biologic and evolutive characteristics are emphasized, discussing preoperatory study and surgical technics.

  7. Body condition of feral cats and the effect of neutering.

    PubMed

    Scott, Karen C; Levy, Julie K; Gorman, Shawn P; Newell, Susan M

    2002-01-01

    Considerable debate exists regarding the most appropriate methods for controlling feral cat populations, both from humane and logistical points of view. The physical condition of feral cats has not been reported, and it is not known if these cats benefit from neutering. This study investigates the body condition of feral cats by measuring body weight (BW), body condition score (BCS; Burkholder, 2000; Laflamme, Kealy, & Schmidt, 1994), and falciform fat pad. The study includes lateral abdominal radiographs taken at the time of neutering of 105 adult feral cats for measurement of falciform fat pad depth and area. At that time we also assessed BW and BCS. One year later we assessed the effects of neutering on body condition by evaluating a subsample of 14 cats. At the time of surgery, the cats were lean but not emaciated (BW 3.1 +/- 0.9 kg; BCS 4 +/- 1; based on a 1 to 9 scale ranging from 1 [emaciated] to 9 [grossly obese]). Falciform fat pad depth and area averaged 7.1 mm and 197.4 mm2, respectively, indicating a small amount of fat. Fourteen cats, reevaluated 1 year after neutering, increased 260% + 90% in falciform fat pad depth, 420% +/- 390% in fat pad area, 40% +/- 4% in BW, and 1 level in BCS ranking (1 to 9 scale; all differences p <.001). Similar to confined socialized cats, feral cats gained significant weight and body fat after neutering.

  8. 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.

  9. Cerebral foreign body reaction after carotid aneurysm stenting

    PubMed Central

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

    2016-01-01

    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

  10. 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

  11. Contribution of endothelin-1 to the enhanced carotid body chemosensory responses induced by chronic intermittent hypoxia.

    PubMed

    Rey, Sergio; Del Rio, Rodrigo; Iturriaga, Rodrigo

    2006-05-01

    Chronic intermittent hypoxia (CIH) enhances carotid body (CB) chemosensory responses to acute hypoxia. We tested the hypothesis that endothelin-1 (ET-1), an excitatory modulator of CB chemoreception may contribute to the enhanced CB chemosensory responses in cats exposed to cyclic hypoxic episodes repeated during 8 h for 4 days. Accordingly, we measured the ET-1 immunoreactivity (ET-ir) in the CB and plasma. Using a perfused CB preparation, we studied the effects of exogenous ET-1 and bosentan, a non-selective endothelin receptor type A and B antagonist, on the frequency of chemosensory discharges (f(x)) during normoxia, mild and severe hypoxia. We found that CIH increased ET-ir in the CB by approximately 10-fold leaving ET-1 plasma levels unchanged. Application of ET-1 to control and CIH-treated CBs produced long-lasting dose-dependent increases in f(x), although the dose-response curve showed a rightward-shift in the CIH-treated CBs. CIH increased baseline f(x) and hypoxic chemosensory responses, which were reduced by 50 microM bosentan in CBs from CIH-treated cats. Present results suggest that a local increase of ET-1 in the CB may contribute to the enhanced chemosensory responses induced by CIH predominantly through a vasomotor mechanism.

  12. Regulation of the common carotid arterial blood flow by nicotinic receptors in the medulla of cats

    PubMed Central

    Gong, C-L; Chiu, Y-T; Lin, N-N; Cheng, C-C; Lin, S-Z; Lee, T J-F; Kuo, J-S

    2006-01-01

    Background and purpose: Actions of glutamate and serotonin on their respective receptors in the dorsal facial area (DFA) of the medulla are known to regulate common carotid arterial (CCA) blood flow in cats. Less is known about acetylcholine action on its nicotinic receptor (nAChR) subtypes in the DFA for regulation of CCA blood flow and this aspect was investigated. Experimental approach: Nicotinic and muscarinic agonists and antagonists were microinjected into the DFA through a three-barrel tubing in anesthetized cats. Results: CCA blood flow was dose-dependently increased by nicotine (a non-selective nAChR agonist) and choline (a selective α7-nAChR agonist). These effects of nicotine were attenuated by α-bungarotoxin (an α7-nAChR antagonist), methyllycaconitine (an α7-nAChR antagonist), mecamylamine (a relatively selective α3β4-nAChR antagonist) and dihydro-β-erythroidine (a relatively selective α4β2-nAChR antagonist). The choline-induced flow increase was attenuated by α-bungarotoxin and mecamylamine, but not by dihydro-β-erythroidine. Muscarinic agonists (muscarine and methacholine) and antagonist (atropine) affected neither the basal nor the nicotine-induced increase in the CCA blood flow. Conclusions and implications: Functional α7, α4β2, and α3β4 subunits of the nAChR appear to be present on the DFA neurons. Activations of these receptors increase the CCA blood flow. The present findings do not preclude the presence of other nAChRs subunits. Muscarinic receptors, if any, on the DFA are not involved in regulation of the CCA blood flow. Various subtypes of nAChRs in the DFA may mediate regulation of the CCA and cerebral blood flows. PMID:16894347

  13. Does yawning increase arousal through mechanical stimulation of the carotid body?

    PubMed

    Matikainen, Jorma; Elo, Hannu

    2008-01-01

    Yawning is a stereotyped event that occurs in humans and animals from fish to mammals, but neither its mechanisms nor its functions are entirely known. Its widespread nature suggests that it has important physiological functions. It is associated with stretching of muscles in a large area, but the function of this stretching is understood far from completely. It has been proposed that yawning increases arousal and that it is an arousal defense reflex, whose aim is to reverse brain hypoxia. Whilst yawning has been speculated to have an important role in reversing hypoxia, there is a structure in the neck that is known to be intimately involved in the regulation of oxygen homeostasis, namely the carotid body. It senses acute changes in oxygen levels. In spite of this, a connection has never been proposed either between the carotid body and arousal, or between yawning and the carotid body. We propose that yawning stimulates mechanically the carotid body (and possibly other structures in the neck). We further propose that this stimulation gives rise to increased arousal, alertness and wakefulness and that one important physiological function of yawning is increase of arousal through this stimulation. We also propose that mechanical effects on the shunt system of the carotid body may be involved in this stimulation. Our hypothesis is supported by several facts. For example, yawning causes movements and compressions that may affect the carotid body that is situated strategically at the bifurcation of the common carotid artery. Thus, yawning may stimulate the carotid body. The carotid body is highly vascular and compressions may affect its shunt system and blood flow and for example give rise to release of hormones or other substances. Also several facts related to situations where people yawn or do not yawn support our hypothesis and are discussed. Further support comes from facts related to somnogenic substances, hormones and transmitters, and from facts related to the

  14. Expression of tandem P domain K+ channel, TREK-1, in the rat carotid body.

    PubMed

    Yamamoto, Y; Taniguchi, K

    2006-04-01

    TREK-1 is one of the important potassium channels for regulating membrane excitability. To examine the distribution of TREK-1 in the rat carotid body, we performed RT-PCR for mRNA expression and in situ hybridization and immunohistochemistry for tissue distribution of TREK-1. RT-PCR detected mRNA expression of TREK-1 in the carotid body. Furthermore, in situ hybridization revealed the localization of TREK-1 mRNA in the glomus cells. TREK-1 immunoreactivity was mainly distributed in the glomus cells and nerve fibers in the carotid body. TREK-1 may modulate potassium current of glomus cells and/or afferent nerve endings in the rat carotid body.

  15. Correlation between adenosine triphosphate levels, dopamine release and electrical activity in the carotid body: support for the metabolic hypothesis of chemoreception.

    PubMed

    Obeso, A; Almaraz, L; Gonzalez, C

    1985-11-25

    An unsolved issue for the arterial chemoreceptors is the mechanism by which hypoxia and other natural stimuli lead to an increase of activity in the carotid sinus nerve. According to the 'metabolic hypothesis', the hypoxic activation of the carotid body (CB) is mediated by a decrease of the ATP levels in the type I cells, which then release a neurotransmitter capable of exciting the sensory nerve endings. Using an in vitro preparation of cat CB, we report that ATP levels in the CB do in fact decrease when the organs are exposed to moderate, short lasting hypoxia (5 min 20% O2). Additionally, we found that decreases in ATP levels induced by 2-deoxyglucose (2 mM) or sodium cyanide (0.1 mM) are closely correlated with dopamine release from type I cells and electrical activity in the carotid sinus nerve elicited by these agents. The possible cause-effect relationship of these events is discussed.

  16. General redox environment and carotid body chemoreceptor function.

    PubMed

    Agapito, Maria Teresa; Sanz-Alfayate, Gloria; Gomez-Niño, Angela; Gonzalez, Constancio; Obeso, Ana

    2009-03-01

    Carotid body (CB) chemoreceptor cells detect physiological levels of hypoxia and generate a hyperventilation, homeostatic in nature, aimed to minimize the deleterious effects of hypoxia. Intimate mechanisms involved in oxygen sensing in chemoreceptor cells remain largely unknown, but reactive oxygen species (ROS) had been proposed as mediators of this process. We have determined glutathione levels and calculated glutathione redox potential (E(GSH); indicator of the general redox environment of cells) in rat diaphragms incubated in the presence of oxidizing agents of two types: nonpermeating and permeating through cell membranes; in the latter group, unspecific oxidants and inhibitors of ROS-disposing enzymes were used. Selected concentrations of oxidizing agents were tested for their ability to modify the normoxic and hypoxic activity of chemoreceptor cells measured in vitro as their rate of release of neurotransmitters. Results evidence variable relationships between E(GSH) and the activity of chemoreceptor cells. The independence of chemoreceptor cell activity from the E(GSH) would imply that the ability of the CB to play its homeostatic role is largely preserved in any pathological or toxicological contingency causing oxidative stress. Consistent with this suggestion, it was also found that CB-mediated hypoxic hyperventilation was not altered by treatment of intact animals with agents that markedly decreased the E(GSH) in all tissues assayed.

  17. Mechanisms of carotid body chemoreflex dysfunction during heart failure

    PubMed Central

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

    2015-01-01

    Recent advances have drawn interest in the potential for carotid body (CB) ablation or desensitization as an effective strategy for clinical treatment and management of cardio-respiratory diseases including hypertension, heart failure, diabetes mellitus, metabolic syndrome, and renal failure. These disease states have in common sympathetic overactivity, which plays an important role in the development and progression of the disease and is often associated with breathing dysregulation, which in turn likely mediates or aggravates the autonomic imbalance. Evidence from both chronic heart failure (CHF) patients and animal models indicates that the CB chemoreflex is enhanced in CHF and contributes to the tonic elevation in sympathetic activity and the development of periodic breathing associated with the disease. Although this maladaptive change likely derives from altered function at all levels of the reflex arc, a tonic increase in afferent activity from CB glomus cells is likely to be a main driving force. This report will focus on our understanding of mechanisms that alter CB function in CHF and their potential translational impact on treatment of CHF. PMID:25398713

  18. Ultrastructure of the carotid body of the goat.

    PubMed

    Abdel-Magied, E M; Taha, A A

    1995-09-01

    The carotid body of the goat was found to be a small oval or rounded parenchymatous organ. It was characterized by its profound vascularity. Delicate septa divided the parenchyma into small feebly defined lobules. Electron microscopy revealed that the parenchyma comprised type I cells, type II cells, nerve endings, axons and fenestrated dilated capillaries. Type I cells were characterized with electron dense-cored vesicles. They showed variations in size and concentration of the dense-cored vesicles and number of mitochondria. The possibility that these variations are reflections of different stages of activity is discussed. Type II cells were less numerous than type I cells, relatively small and devoid of dense-cored vesicles. They usually surrounded small groups of type I cells and associated nerve endings and axons. Presumptive afferent nerve endings characterized with many clear vesicles, occasional large granular vesicles and varying numbers of slender mitochondria, lay apposed to type I cells. Nerve endings of this kind showed afferent and efferent synaptic junctions with type I cells. Presumptive sympathetic efferent endings were occasionally seen within the lobules but never lay apposed to type I cells or afferent nerve ending.

  19. Carotid body oxygen sensing and adaptation to hypoxia.

    PubMed

    López-Barneo, José; Macías, David; Platero-Luengo, Aida; Ortega-Sáenz, Patricia; Pardal, Ricardo

    2016-01-01

    The carotid body (CB) is the principal arterial chemoreceptor that mediates the hyperventilatory response to hypoxia. Our understanding of CB function and its role in disease mechanisms has progressed considerably in the last decades, particularly in recent years. The sensory elements of the CB are the neuron-like glomus cells, which contain numerous transmitters and form synapses with afferent sensory fibers. The activation of glomus cells under hypoxia mainly depends on the modulation of O2-sensitive K(+) channels which leads to cell depolarization and the opening of Ca(2+) channels. This model of sensory transduction operates in all mammalian species studied thus far, including man. However, the molecular mechanisms underlying the modulation of ion channel function by changes in the O2 level are as yet unknown. The CB plays a fundamental role in acclimatization to sustained hypoxia. Mice with CB atrophy or patients who have undergone CB resection due to surgical treatments show a marked intolerance to even mild hypoxia. CB growth under hypoxia is supported by the existence of a resident population of neural crest-derived stem cells of glia-like phenotype. These stem cells are not highly affected by exposure to low O2 tension; however, there are abundant synapse-like contacts between the glomus cells and stem cells (chemoproliferative synapses), which may be needed to trigger progenitor cell proliferation and differentiation under hypoxia. CB hypo- or hyper-activation may also contribute to the pathogenesis of several prevalent human diseases.

  20. Adrenergic mechanisms in oxygen chemoreception in the cat aortic body.

    PubMed

    Mulligan, E; Lahiri, S; Mokashi, A; Matsumoto, S; McGregor, K H

    1986-03-01

    Sixteen cats were studied to test the hypothesis that oxygen chemoreception in the cat aortic body is dependent on the beta-adrenergic mechanism. The chemoreceptor activity was measured from a few aortic chemoreceptor afferents in each cat, anesthetized with alpha-chloralose (60 mg X kg-1). Three types of experiments were conducted. Aortic chemoreceptor responses to steady-state hypoxia (PaO2 range, 100-30 Torr) were measured (a) before and during intravenous infusion of the beta-receptor agonist, isoproterenol (0.5 micrograms X kg-1) in nine spontaneously breathing cats, and (b) before and after intravenous injection of the beta-receptor antagonist, propranolol (1 mg X kg-1) in seven cats which were paralyzed and artificially ventilated. In the third category (c) the stimulatory effect of hypotension on aortic chemoreceptor activity was measured in six of the seven cats in group (b) before and after propranolol injection. Isoproterenol infusion only moderately stimulated aortic chemoreceptor activity. This stimulation was blocked by propranolol. However, propranolol did not attenuate aortic chemoreceptor responses to hypoxia or to hypotension. We conclude that the beta-receptor adrenergic mechanism does not mediate oxygen chemoreception in the cat aortic body.

  1. 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

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

    PubMed

    Kromhout, Kaatje; Gielen, Ingrid; De Cock, Hilde E V; Van Dyck, Kristof; van Bree, Henri

    2012-04-16

    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.

  3. Carotid body chemoreception in the absence and presence of CO2-HCO3-.

    PubMed

    Iturriaga, R; Lahiri, S

    1991-12-24

    Carotid body (CB) chemosensory responses to natural and pharmacological stimuli were studied in vitro in the presence and nominal absence of CO2-HCO3- in the perfusion-superfusion media. The CBs obtained from cats (n = 10), anesthetized with sodium pentobarbitone, were simultaneously perfused and superfused with a modified Tyrode solution at 36.5 +/- 0.5 degrees C, equilibrated respectively with PO2 of 120 and less than 20 Torr. The Tyrode, nominally free of CO2-HCO3- (HEPES-NaOH, pH 7.38, 310 mOsm), was used first. Subsequently the Tyrode containing HEPES-HCO3-, equilibrated with PCO2 of 36.8 Torr (pH 7.38) was used. Chemosensory discharges were recorded from the carotid sinus nerve. Both hypoxia (PO2 = 20-25 Torr) and ischemic hypoxia stimulated the discharge in the absence and presence of CO2-HCO3-. However, the presence of CO2-HCO3- significantly raised the baseline activity, augmented the speed, sensitivity and the maximal responses to both types of hypoxia. Hypercapnic perfusate (PCO2 = 65 Torr at pH 7.17) produced a peak response equally promptly in the absence and presence of CO2-HCO3- in the ongoing perfusate but generated a larger and more sustained response. Presence of CO2-HCO3- strongly potentiated the responses to cyanide (10(-10)-10(-7) mol) but less strikingly the responses to nicotine (10(-11)-10(-8) mol). Thus, the extracellular CO2-HCO3- significantly improved the response to hypoxia but was not essential for O2 chemoreception. The underlying mechanisms of the effect of CO2-HCO3- is likely to be mediated by the Cl(-)-HCO3- anion exchanger in the pH regulation of glomus cells.

  4. A simple technique to achieve bloodless excision of carotid body tumors.

    PubMed

    Spinelli, Francesco; Massara, Mafalda; La Spada, Michele; Stilo, Francesco; Barillà, David; De Caridi, Giovanni

    2014-05-01

    We describe a technique for Shamblin II-III carotid body tumor (CBT) resection to reduce bleeding and neurologic complications during surgery. The technique was based on the fact that CBTs are supplied almost exclusively from the external carotid artery. Therefore, we carefully isolated the origin of the external carotid artery and its distal branches outside the tumor and temporarily clamped all of these vessels after heparin administration. This allowed a safe and bloodless resection as the tumor was dissected from the internal carotid artery in the usual subadventitial plane. The internal carotid artery was never clamped, and respect of peripheral nerves was warranted in the clean and bloodless field. From 2007 to 2010, we treated 11 patients with a CBT: six had a Shamblin II and five had a Shamblin III lesion. Neither perioperative neurologic events nor recurrences occurred after a mean follow-up of 42 months.

  5. Neonatal Maternal Separation Augments Carotid Body Response to Hypoxia in Adult Males but Not Female Rats

    PubMed Central

    Soliz, Jorge; Tam, Rose; Kinkead, Richard

    2016-01-01

    Perinatal exposure to adverse experiences disrupts brain development, including the brainstem network that regulates breathing. At adulthood, rats previously subjected to stress (in the form of neonatal maternal separation; NMS) display features reported in patients suffering from sleep disordered breathing, including an increased hypoxic ventilatory response and hypertension. This effect is also sex-specific (males only). Based on these observations, we hypothesized that NMS augments the carotid body's O2-chemosensitivity. Using an isolated and perfused ex vivo carotid body preparation from adult rats we compared carotid sinus nerve (CSN) responses to hypoxia and hypercapnia in carotid bodies harvested from adult rats that either experienced control conditions (no experimental manipulation) or were subjected to NMS (3 h/day from postnatal days 3 to 12). In males, the CSN response to hypoxia measured in preparations from NMS males was 1.5 fold higher than controls. In control rats, the female's response was similar to that of males; however, the increase in CSN activity measured in NMS females was 3.0 times lower than controls. The CSN response to hypercapnia was not influenced by stress or sex. We conclude that NMS is sufficient to have persistent and sex-specific effects on the carotid body's response to hypoxia. Because NMS also has sex-specific effects on the neuroendocrine response to stress, we propose that carotid body function is influenced by stress hormones. This, in turn, leads to a predisposition toward cardio-respiratory disorders. PMID:27729873

  6. Revisiting cAMP signaling in the carotid body

    PubMed Central

    Nunes, Ana R.; Holmes, Andrew P.; Conde, Sílvia V.; Gauda, Estelle B.; Monteiro, Emília C.

    2014-01-01

    Chronic carotid body (CB) activation is now recognized as being essential in the development of hypertension and promoting insulin resistance; thus, it is imperative to characterize the chemotransduction mechanisms of this organ in order to modulate its activity and improve patient outcomes. For several years, and although controversial, cyclic adenosine monophosphate (cAMP) was considered an important player in initiating the activation of the CB. However, its relevance was partially displaced in the 90s by the emerging role of the mitochondria and molecules such as AMP-activated protein kinase and O2-sensitive K+ channels. Neurotransmitters/neuromodulators binding to metabotropic receptors are essential to chemotransmission in the CB, and cAMP is central to this process. cAMP also contributes to raise intracellular Ca2+ levels, and is intimately related to the cellular energetic status (AMP/ATP ratio). Furthermore, cAMP signaling is a target of multiple current pharmacological agents used in clinical practice. This review (1) provides an outline on the classical view of the cAMP-signaling pathway in the CB that originally supported its role in the O2/CO2 sensing mechanism, (2) presents recent evidence on CB cAMP neuromodulation and (3) discusses how CB activity is affected by current clinical therapies that modify cAMP-signaling, namely dopaminergic drugs, caffeine (modulation of A2A/A2B receptors) and roflumilast (PDE4 inhibitors). cAMP is key to any process that involves metabotropic receptors and the intracellular pathways involved in CB disease states are likely to involve this classical second messenger. Research examining the potential modification of cAMP levels and/or interactions with molecules associated with CB hyperactivity is currently in its beginning and this review will open doors for future explorations. PMID:25389406

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

    PubMed Central

    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

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

    PubMed Central

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

    2013-01-01

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

  9. Effects of hypoxia on catecholamine synthesis in rabbit carotid body in vitro

    PubMed Central

    Fidone, S.; Gonzalez, C.; Yoshizaki, K.

    1982-01-01

    1. Unanaesthetized, unrestrained rabbits were exposed for 3 hr in a chamber to either air, hypoxic gas mixtures (10% or 14% O2 in N2) or a hyperoxic gas mixture (50% O2 in N2). The carotid bodies were then removed and incubated for 3 hr in modified Tyrode media equilibrated with 100% O2 and containing either [3H]tyrosine or [3H]DOPA. The contents of [3H]DA and [3H]NA in the tissue were determined as described in the preceding paper. 2. When [3H]DOPA was used as precursor, neither labelled dopamine (DA) or noradrenaline (NA) synthesis was increased in carotid bodies from rabbits exposed to 10% O2 in N2. Following exposure to 10% O2 in N2 and incubation with [3H]tyrosine, however, [3H]DA synthesis was increased by 72% above control (air) values while [3H]NA synthesis was unchanged. Less severe hypoxia, 14% O2 in N2, resulted in a smaller increase in [3H]DA synthesis, i.e. 53% above control value. Again, [3H]NA synthesis was unchanged. Similar experiments with the superior cervical ganglion involving exposure of the animals to either 10% or 14% O2 in N2 did not produce any change in the amounts of [3H]DA or [3H]NA synthesized from [3H]tyrosine when compared to control animals breathing air. 3. Sympathectomy of the carotid body or transection of the carotid sinus nerve 12-15 days prior to hypoxic exposure (10% O2 in N2) did not alter the increase in [3H]DA synthesis compared to normally innervated carotid bodies. 4. Carotid bodies incubated with [3H]tyrosine for 2 hr in an alternating O2/N2 sequence (5 min in media equilibrated with 100% O2 followed by 3 min in media equilibrated with 100% N2) synthesized 37% more [3H]DA than control carotid bodies similarly exposed to an alternating O2/O2 sequence. [3H]NA synthesis was unchanged. However, tissue levels of non-metabolized [3H]tyrosine were reduced by 19% in the carotid bodies exposed to the O2/N2 sequence. 5. Exposure of rabbits for 3 hr to 50% O2 in N2, followed by incubation of their carotid bodies in [3H

  10. Chronic hyperoxia alters the expression of neurotrophic factors in the carotid body of neonatal rats.

    PubMed

    Dmitrieff, Elizabeth F; Wilson, Julia T; Dunmire, Kyle B; Bavis, Ryan W

    2011-02-15

    Chronic exposure to hyperoxia alters the postnatal development and innervation of the rat carotid body. We hypothesized that this plasticity is related to changes in the expression of neurotrophic factors or related proteins. Rats were reared in 60% O(2) from 24 to 36h prior to birth until studied at 3d of age (P3). Protein levels for brain-derived neurotrophic factor (BDNF) were significantly reduced (-70%) in the P3 carotid body, while protein levels for its receptor, tyrosine kinase B, and for glial cell line-derived neurotrophic factor (GDNF) were unchanged. Transcript levels in the carotid body were downregulated for the GDNF receptor Ret (-34%) and the neuropeptide Vgf (-67%), upregulated for Cbln1 (+205%), and unchanged for Fgf2; protein levels were not quantified for these genes. Immunohistochemical analysis revealed that Vgf and Cbln1 proteins are expressed within the carotid body glomus cells. These data suggest that BDNF, and perhaps other neurotrophic factors, contribute to abnormal carotid body function following perinatal hyperoxia.

  11. Carotid body chemosensory responses in mice deficient of TASK channels

    PubMed Central

    Ortega-Sáenz, Patricia; Levitsky, Konstantin L.; Marcos-Almaraz, María T.; Bonilla-Henao, Victoria; Pascual, Alberto

    2010-01-01

    Background K+ channels of the TASK family are believed to participate in sensory transduction by chemoreceptor (glomus) cells of the carotid body (CB). However, studies on the systemic CB-mediated ventilatory response to hypoxia and hypercapnia in TASK1- and/or TASK3-deficient mice have yielded conflicting results. We have characterized the glomus cell phenotype of TASK-null mice and studied the responses of individual cells to hypoxia and other chemical stimuli. CB morphology and glomus cell size were normal in wild-type as well as in TASK1−/− or double TASK1/3−/− mice. Patch-clamped TASK1/3-null glomus cells had significantly higher membrane resistance and less hyperpolarized resting potential than their wild-type counterpart. These electrical parameters were practically normal in TASK1−/− cells. Sensitivity of background currents to changes of extracellular pH was drastically diminished in TASK1/3-null cells. In contrast with these observations, responsiveness to hypoxia or hypercapnia of either TASK1−/− or double TASK1/3−/− cells, as estimated by the amperometric measurement of catecholamine release, was apparently normal. TASK1/3 knockout cells showed an enhanced secretory rate in basal (normoxic) conditions compatible with their increased excitability. Responsiveness to hypoxia of TASK1/3-null cells was maintained after pharmacological blockade of maxi-K+ channels. These data in the TASK-null mouse model indicate that TASK3 channels contribute to the background K+ current in glomus cells and to their sensitivity to external pH. They also suggest that, although TASK1 channels might be dispensable for O2/CO2 sensing in mouse CB cells, TASK3 channels (or TASK1/3 heteromers) could mediate hypoxic depolarization of normal glomus cells. The ability of TASK1/3−/− glomus cells to maintain a powerful response to hypoxia even after blockade of maxi-K+ channels, suggests the existence of multiple sensor and/or effector mechanisms, which could

  12. 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.

  13. 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.

  14. Long-term regulation of carotid body function: acclimatization and adaptation--invited article.

    PubMed

    Prabhakar, N R; Peng, Y-J; Kumar, G K; Nanduri, J; Di Giulio, C; Lahiri, Sukhamay

    2009-01-01

    Physiological responses to hypoxia either continuous (CH) or intermittent (IH) depend on the O(2)-sensing ability of the peripheral arterial chemoreceptors, especially the carotid bodies, and the ensuing reflexes play important roles in maintaining homeostasis. The purpose of this article is to summarize the effects of CH and IH on carotid body function and the underlying mechanisms. CH increases baseline carotid body activity and sensitizes the response to acute hypoxia. These effects are associated with hyperplasia of glomus cells and neovascularization. Enhanced hypoxic sensitivity is due to alterations in ion current densities as well as changes in neurotransmitter dynamics and recruitment of additional neuromodulators (endothelin-1, ET-1) in glomus cells. Morphological alterations are in part due to up-regulation of growth factors (e.g. VEGF). Hypoxia-inducible factor-1 (HIF-1), a transcriptional activator might underlie the remodeling of carotid body structure and function by CH. Chronic IH, on the other hand, is associated with recurrent apneas in adults and premature infants. Two major effects of chronic IH on the adult carotid body are sensitization of the hypoxic sensory response and long-lasting increase in baseline activity i.e., sensory long-term facilitation (LTF) which involve reactive oxygen species (ROS) and HIF-1. In neonates, chronic IH leads to sensitization of the hypoxic response but does not induce sensory LTF. Chronic IH-induced sensitization of the carotid body response to hypoxia increases the likelihood of unstable breathing perpetuating in more number of apneas, whereas sensory LTF may contribute to increased sympathetic tone and systemic hypertension associated with recurrent apneas.

  15. Iatrogenic central retinal artery occlusion after carotid body tumor embolization and excision

    PubMed Central

    Rangel, Carlos M.; Jaramillo, Sergio; Varón, Clara L.; Prada, Angélica M.

    2017-01-01

    Objective: To report a case of iatrogenic central retinal artery occlusion after embolization and surgical resection of carotid body paraganglioma. Methods: Case report Results: One adult female patient presented with persistent unilateral visual loss after embolization with Embosphere® and Contour® microparticles of carotid body tumor. Fluorescein angiography revealed intraluminal microspheres in the central retinal artery ramifications. OCT revealed intraretinal spherical, hyporeflective particles with posterior shadowing. Conclusions: Central retinal artery occlusion should be assessed as a possible complication after surgical repair of head and neck paragangliomas.

  16. Carotid body chemoreception: the importance of CO2-HCO3- and carbonic anhydrase. (review).

    PubMed

    Iturriaga, R

    1993-01-01

    The current hypotheses of carotid body (CB) chemoreception regard the glomus cells as the initial site of stimulus transduction. The consensus is that the transduction of chemical stimulus is coupled with the release of transmitter(s) from the glomus cells, which in turn generates action potentials in the afferent nerve terminals. Carbonic anhydrase (CA) is present in the glomus cells of the CB. Inhibition of CA activity in the CB in situ reduces the carotid chemosensory responses to CO2 and to O2, suggesting a common mechanism of chemosensing for both stimuli. However, CA inhibitors also block the red blood cell enzyme. Thus, the CO2 hydration reaction does not come to completion within the transit time of the blood from the lung to the CB. A steady-state reaction is not reached until later and so the PCO2 and pH levels in arterial blood samples are not the same as those sensed by the CB. Experiments in vitro using cat CB perfused and superfused with cell-free solutions, which had been pre-equilibrated with respiratory gases, strongly support the proposition that the CA activity in CB cells is essential for the speed and amplitude of the initial response to CO2 and for its subsequent adaptation. The immediate response to hypoxia also is delayed, but the late steady-state was less dependent on CA activity. In the nominal absence of CO2-HCO3- from the perfusate, hypoxic chemoreception persisted and its magnitude is not affected by CA inhibition, except for a delay which may be due to the initial alkaline pH of the glomus cells. Recent experiments performed in isolated glomus cells and in the whole CB show that hypoxia does not modify significantly the intracellular pH. By its simple catalytic function, CA can speed up the approach of the CO2 hydration reaction to equilibrium. However, CA may also contribute in the steady-state to the regulation of pHi by providing a continuous supply of H+ and HCO3-. Furthermore, CA performs a facilitatory role in the physiological

  17. Effect of CO on VO2 of carotid body and chemoreception with and without Ca2+.

    PubMed

    Lahiri, S; Buerk, D G; Osanai, S; Mokashi, A; Chugh, D K

    1997-09-10

    This study was done using high PCO (> 500 Torr at PO2 of 120 Torr) in the carotid body perfusate in vitro, and recording simultaneously the activity of the whole carotid sinus nerve (CSN) and VO2 of the carotid body. In the cascade of excitation of CSN by high PCO in the dark [light eliminated the excitation; S. Lahiri, News Physiol. Sci. 9 (1992) 161-165], Ca2+ effects occur at the level of neurosecretion after the level of oxygen consumption, according to the following scheme: CO-hypoxia-->VO2 decrease-->K+ conductance decrease-->cell depolarization-->cytosolic Ca2+ rise-->neurosecretion-->neural discharge. Thus, a part of the hypothesis was that [Ca2+] decrease, being a downstream event, may not affect VO2 of the carotid body. Also, to determine to what extent the intracellular calcium stores contribute to cystolic [Ca2+] and chemosensory discharge with high PCO, we tested the effect of interruption of perfusate flow with medium nominally free of [Ca2+] on CSN excitation and VO2 of the carotid body with and without high PCO. High PCO in the dark decreased carotid body VO2, independent of [Ca2+]o. CSN excitation was always enhanced by high PCO, and its sensitivity to perfusate flow interruption. Also, nominally Ca(2+)-free solution increased the latency and decreased the rate of rise and peak activity of CSN during interruption of perfusate flow, but CO augmented the responses. This reversal effect by CO suggests that Ca2+ is released from intracellular stores, because CO has no other way to excite the chemoreceptors than by acting on the intracellular stores.

  18. Separation of carotid body chemoreceptor responses to O2 and CO2 by oligomycin and by antimycin A.

    PubMed

    Mulligan, E; Lahiri, S

    1982-03-01

    The cat carotid chemoreceptor O2 and CO2 responses can be separated by oligomycin and by antimycin A. Both of these agents greatly diminish or abolish the chemoreceptor O2 response but not the nicotine or CO2 responses. After either oligomycin or antimycin, the responses to increases and decreases in arterial CO2 partial pressure (PaCO2) consisted of increases and decreases in activity characterized respectively by exaggerated overshoots and undershoots. These were eliminated by the carbonic anhydrase inhibitor, acetazolamide, suggesting that they resulted from changes in carotid body tissue pH. The steady-state PaCO2 response remaining after oligomycin was no longer dependent on arterial O2 partial pressure (PaO2). All effects of antimycin were readily reversible in about 20 min. The separation of the responses to O2 and CO2 indicates that there may be at least partially separate pathways of chemoreception for these two stimuli. The similarity of the oligomycin and antimycin results supports the metabolic hypothesis of chemoreception.

  19. 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

  20. Towards the sensory nature of the carotid body: hering, de castro and heymansdagger.

    PubMed

    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.

  1. Big cat, small cat: reconstructing body size evolution in living and extinct Felidae.

    PubMed

    Cuff, A R; Randau, M; Head, J; Hutchinson, J R; Pierce, S E; Goswami, A

    2015-08-01

    The evolution of body mass is a fundamental topic in evolutionary biology, because it is closely linked to manifold life history and ecological traits and is readily estimable for many extinct taxa. In this study, we examine patterns of body mass evolution in Felidae (Placentalia, Carnivora) to assess the effects of phylogeny, mode of evolution, and the relationship between body mass and prey choice in this charismatic mammalian clade. Our data set includes 39 extant and 26 extinct taxa, with published body mass data supplemented by estimates based on condylobasal length. These data were run through 'SURFACE' and 'bayou' to test for patterns of body mass evolution and convergence between taxa. Body masses of felids are significantly different among prey choice groupings (small, mixed and large). We find that body mass evolution in cats is strongly influenced by phylogeny, but different patterns emerged depending on inclusion of extinct taxa and assumptions about branch lengths. A single Ornstein-Uhlenbeck optimum best explains the distribution of body masses when first-occurrence data were used for the fossil taxa. However, when mean occurrence dates or last known occurrence dates were used, two selective optima for felid body mass were recovered in most analyses: a small optimum around 5 kg and a large one around 100 kg. Across living and extinct cats, we infer repeated evolutionary convergences towards both of these optima, but, likely due to biased extinction of large taxa, our results shift to supporting a Brownian motion model when only extant taxa are included in analyses.

  2. Carotid Ultrasound Imaging

    MedlinePlus

    ... Index A-Z Ultrasound - Carotid Carotid ultrasound uses sound waves to produce pictures of the carotid arteries ... pictures of the inside of the body using sound waves. Ultrasound imaging, also called ultrasound scanning or ...

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

    PubMed

    De Castro, F

    2009-01-01

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

  4. 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.

  5. Regulation of common carotid arterial blood flow by nitrergic neurons in the medulla of cats.

    PubMed

    Gong, Chi-Li; Chiu, Yung-Tsung; Lin, Nai-Nu; Cheng, Ching-Chang; Li, Hsing-Tan; Kuo, Jon-Son

    2007-02-05

    Glutamate stimulation of the dorsal facial area, an area located dorsal to the facial nucleus, increases common carotid arterial blood flow. Nitrergic neurons are important in cardiovascular regulatory areas. We investigated whether the nitrergic neurons might be present and play a role in the dorsal facial area to regulate the arterial blood flow. Injections of L-arginine (an NO precursor) and sodium nitroprusside (an NO donor) into the area caused dose-dependent increases in the arterial blood flow. Injection of N(G)-nitro-arginine methyl ester (L-NAME, an NO synthase inhibitor) or methylene blue (a guanylate cyclase inhibitor) decreased the arterial blood flow. Nitrergic neurons and fibers were found in the dorsal facial area by histochemical staining of nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase, a maker of NO synthase. In conclusion, nitrergic neurons are present in the dorsal facial area and appear to release NO tonically in stimulating the area to cause increase in common carotid arterial blood flow.

  6. 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.

  7. Hes1 is required for the development of the superior cervical ganglion of sympathetic trunk and the carotid body.

    PubMed

    Kameda, Yoko; Saitoh, Takayoshi; Nemoto, Noriko; Katoh, Tokio; Iseki, Sachiko

    2012-08-01

    Hes1 gene represses the expression of proneural basic helix-loop-helix (bHLH) factor Mash1, which is essential for the differentiation of the sympathetic ganglia and carotid body glomus cells. The sympathetic ganglia, carotid body, and common carotid artery in Wnt1-Cre/R26R double transgenic mice were intensely labeled by X-gal staining, i.e., the neural crest origin. The deficiency of Hes1 caused severe hypoplasia of the superior cervical ganglion (SCG). At embryonic day (E) 17.5-E18.5, the volume of the SCG in Hes1 null mutants was reduced to 26.4% of the value in wild-type mice. In 4 of 30 cases (13.3%), the common carotid artery derived from the third arch artery was absent in the null mutants, and the carotid body was not formed. When the common carotid artery was retained, the organ grew in the wall of the third arch artery and glomus cell precursors were provided from the SCG in the null mutants as well as in wild-types. However, the volume of carotid body in the null mutants was only 52.5% of the value in wild-types at E17.5-E18.5. These results suggest that Hes1 plays a critical role in regulating the development of neural crest derivatives in the mouse cervical region.

  8. Chemoreceptor discharges and cytochrome redox changes of the rat carotid body: Role of heme ligands

    PubMed Central

    Lahiri, Sukhamay; Ehleben, Wilhelm; Acker, Helmut

    1999-01-01

    In superfused in vitro rat carotid body, we recorded chemoreceptor discharges and the redox state of cytochromes simultaneously to identify the primary oxygen-sensing protein controlling transmitter release and electrical activity of the carotid sinus nerve. These parameters were tested under the influence of heme ligands such as oxygen, cyanide, 4-(2-aminoethyl)-benzenesulfonyl fluoride, and CO. During stimulation, there was an initial increase in discharge frequency followed by a decline or suppression of activity. Photometric changes lagged and were maintained as nerve activity decreased. Reducing mitochondrial cytochromes by cyanide or prolonged severe hypoxia, suppressed the chemoreceptor discharge. 4-(2-Aminoethyl)-benzenesulfonyl fluoride, a specific inhibitor of the phagocytic cytochrome b558, also silenced the chemoreceptors after an initial excitation. CO increased the chemoreceptor discharge under normoxia, an effect inhibited by light, when the cytochromes were not reduced. When the discharges were depressed by severe hypoxia, exposure to light excited the chemoreceptors and the cytochromes were reduced. The rapidity of the chemosensory responses to light and lack of effect on dopamine release from type I cells led us to hypothesize that carotid body type I cells and the apposed nerve endings use different mechanisms for oxygen sensing: the nerve endings generate action potentials in association with membrane heme proteins whereas cytosolic heme proteins signal the redox state, releasing modulators or transmitters from type I cells. PMID:10430959

  9. Imaging findings of malignant bilateral carotid body tumors: A case report and review of the literature

    PubMed Central

    LV, HAN; CHEN, XIAOHONG; ZHOU, SHUAI; CUI, SUPING; BAI, YUNLONG; WANG, ZHENCHANG

    2016-01-01

    Carotid body tumors (CBTs) are a rare type of extra-adrenal paraganglioma, which originate from the carotid body. A 29-year-old woman was admitted to the Department of Head and Neck Surgery, Beijing Tongren Hospital (Capital Medical University, Beijing, China) with hoarseness of the throat, which had progressively worsened over seven months. The patient had a family history of CBTs. Computed tomography and ultrasound imaging revealed multiple well-enhanced masses located at the bilateral carotid bifurcation and in the left parapharyngeal space. Surgery and pathological examination confirmed that the patient had developed regional lymph node metastasis. Significantly enhanced multiple pulmonary and hepatic lesions indicated that the patient had also developed distal metastasis. A genetic analysis performed on the family members of the patient revealed that the family carried a mutated succinate dehydrogenase D gene. In the present study, a systemic review of the literature indicated that extra vigilance is required in familial forms of CBT, in order to increase the standard of treatment for CBT patients. PMID:27073498

  10. Cats

    MedlinePlus

    ... Patients Infants and Young Children Publications & Materials Announcements Cats Recommend on Facebook Tweet Share Compartir Overview Diseases ... hand washing whenever you play or work with cats Wash your hands with soap and running water ...

  11. Trained vs untrained evaluator assessment of body condition score as a predictor of percent body fat in adult cats.

    PubMed

    Shoveller, Anna K; DiGennaro, Joe; Lanman, Cynthia; Spangler, Dawn

    2014-12-01

    Body condition scoring (BCS) provides a readily available technique that can be used by both veterinary professionals and owners to assess the body condition of cats, and diagnose overweight or underweight conditions. The objective of this study was to evaluate a five-point BCS system with half-point delineations using dual-energy x-ray absorptiometry (DXA). Four evaluators (a veterinarian, veterinary technician, trained scorer and untrained scorer) assessed 133 neutered adult cats. For all scorers, BCS score was more strongly correlated with percent body fat than with body weight. Percent body fat increased by approximately 7% within each step increase in BCS. The veterinarian had the strongest correlation coefficient between BCS and percent fat (r = 0.80). Mean body fat in cats classified as being in ideal body condition was 12 and 19%, for 3.0 and 3.5 BCS, respectively. Within BCS category, male cats were significantly heavier in body weight than females within the same assigned BCS category. However, DXA-measured percent body fat did not differ significantly between male and female cats within BCS category, as assigned by the veterinarian (P >0.13). Conversely, when assessed by others, mean percent body fat within BCS category was lower in males than females for cats classified as being overweight (BCS >4.0). The results of this study show that using a BCS system that has been validated within a range of normal weight to moderately overweight cats can help to differentiate between lean cats and cats that may not be excessively overweight, but that still carry a higher proportion of body fat.

  12. Enhanced carotid body chemosensory activity and the cardiovascular alterations induced by intermittent hypoxia

    PubMed Central

    Iturriaga, Rodrigo; Andrade, David C.; Del Rio, Rodrigo

    2014-01-01

    The carotid body (CB) plays a main role in the maintenance of the oxygen homeostasis. The hypoxic stimulation of the CB increases the chemosensory discharge, which in turn elicits reflex sympathetic, cardiovascular, and ventilatory adjustments. An exacerbate carotid chemosensory activity has been associated with human sympathetic-mediated diseases such as hypertension, insulin resistance, heart failure, and obstructive sleep apnea (OSA). Indeed, the CB chemosensory discharge becomes tonically hypereactive in experimental models of OSA and heart failure. Chronic intermittent hypoxia (CIH), a main feature of OSA, enhances CB chemosensory baseline discharges in normoxia and in response to hypoxia, inducing sympathetic overactivity and hypertension. Oxidative stress, increased levels of ET-1, Angiotensin II and pro-inflammatory cytokines, along with a reduced production of NO in the CB, have been associated with the enhanced carotid chemosensory activity. In this review, we will discuss new evidence supporting a main role for the CB chemoreceptor in the autonomic and cardiorespiratory alterations induced by intermittent hypoxia, as well as the molecular mechanisms involved in the CB chemosensory potentiation. PMID:25520668

  13. Deoxyglucose mapping in the cat visual cortex following carotid artery injection and cortical flat-mounting.

    PubMed

    Freeman, B; Löwel, S; Singer, W

    1987-06-01

    Two techniques are described for improving the efficiency of the deoxyglucose metabolic mapping procedure for studies on the cat visual cortex. The first technique involves the bilateral cannulation of the lingual arteries and the symmetrical injection of 2-deoxy-D-[U-14C]glucose in amounts significantly smaller than required with systemic intravenous administration. The second technique is carried out at the end of the stimulation period and involves unfolding the grey matter of the occipital region of the unfixed cortex by blunt dissection (defibrillation) and cutting of the white matter to make a cortical flat-mount: this permits the preparation of large sections parallel to the cortical laminae and thus the interpretation of deoxyglucose uptake patterns in any one lamina over a large area of the visual cortex. The experiments are relatively cheap and the time required to flat-mount the cortices does not seem to produce any significant decrease in spatial resolution of the autoradiograms. In appropriate experiments (published elsewhere) the techniques allow a comparative analysis of the deoxyglucose patterns between hemispheres receiving different visual stimulation.

  14. Multiple effects of nordihydroguaiaretic acid on ionic currents in rat isolated type I carotid body cells

    PubMed Central

    Hatton, C J; Peers, C

    1997-01-01

    The effects of the lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) on the ionic currents of rat carotid body type I cells were investigated by use of whole-cell and outside-out patch clamp techniques. NDGA (5–50 μM) produced a concentration-dependent inhibition of whole-cell K+ currents at all activating test potentials (holding potential −70 mV). The time-course of the inhibition was also concentration-dependent and the effects of NDGA were only reversible following brief periods of exposure (<2 min). Another lipoxygenase inhibitor, phenidone (5 μM), was without effect on whole-cell K+ currents in carotid body type I cells. NDGA (5–50 μM) also inhibited whole-cell Ca2+ channel currents (recorded with Ba2+ as charge carrier) in a concentration-dependent manner. Isolation of voltage-gated K+ channels by use of high [Mg2+] (6 mM), low [Ca2+] (0.1 mM) solutions revealed a direct inhibition of the voltage-sensitive component of the whole-cell K+ current by NDGA (50 μM). In excised, outside-out patches NDGA (20–50 μM) increased large conductance, Ca2+ activated K+ channel activity approximately 10 fold, an effect which could be reversed by either tetraethylammonium (10 mM) or charybdotoxin (30 nM). It is concluded that NDGA activates maxi-K+ channels in carotid body type I cells and over the same concentration range inhibits voltage-sensitive K+ and Ca2+ channels. The inhibition of whole cell K+ currents seen is most likely due to a combination of direct inhibition of the voltage-sensitive K+ current and indirect inhibition of maxi-K+ channel activity through blockade of Ca2+ channels. PMID:9384510

  15. 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

  16. Effects of angiotensin II on leptin and downstream leptin signaling in the carotid body during acute intermittent hypoxia.

    PubMed

    Moreau, J M; Messenger, S A; Ciriello, J

    2015-12-03

    Angiotensin II (ANG II) is known to promote leptin production and secretion. Although ANG II type 1 receptors (AT1Rs) and leptin are expressed within the carotid body, it is not known whether AT1R and leptin are co-expressed in the same glomus cells nor if these peptides are affected within the carotid body by intermittent hypoxia (IH). This study was done to investigate whether ANG II modulated leptin signaling in the carotid body during IH. Rats were treated with captopril (Capt) or the AT1R blocker losartan (Los) in the drinking water for 3days prior to being exposed to IH (8h) or normoxia (8h). IH induced increases in plasma ANG II and leptin compared to normoxic controls. Capt treatment abolished the plasma leptin changes to IH, whereas Los treatment had no effect on the IH induced increase in plasma leptin. Additionally, carotid body glomus cells containing both leptin and the long form of the leptin receptor (OB-Rb) were found to co-express AT1R protein, and IH increased the expression of only AT1R protein within the carotid body in both Capt- and non-Capt-treated animals. On the other hand, Los treatment did not modify AT1R protein expression to IH. Additionally, Capt and Los treatment eliminated the elevated carotid body leptin protein expression, and the changes in phosphorylated signal transducer and activator of transcription three protein, the short form of the leptin receptor (OB-R100), suppressor of cytokine signaling 3, and phosphorylated extracellular-signal-regulated kinase 1/2 protein expression induced by IH. However, Capt elevated the expression of OB-Rb protein, whereas Los abolished the changes in OB-Rb protein to IH. These findings, taken together with the previous observation that ANG II modifies carotid body chemosensitivity, suggest that the increased circulating levels of ANG II and leptin induced by IH act at the carotid body to alter leptin signaling within the carotid body which in turn may influence chemoreceptor function.

  17. Radical resection of a Shamblin type III carotid body tumour without cerebro-neurological deficit: Improved technique with preoperative embolization and carotid stenting.

    PubMed

    Ong, H S; Fan, X D; Ji, T

    2014-12-01

    The surgical resection of a large unfavourable Shamblin type III carotid body tumour (CBT) can be very challenging technically, with many potential significant complications. Preoperative embolization aids in shrinking the lesion, reducing intraoperative blood loss, and improving visualization of the surgical field. Preoperative internal carotid artery (ICA) stenting aids in reinforcing the arterial wall, thereby providing a better dissection plane. A woman presented to our institution with a large right-sided CBT. Failure of the preoperative temporary balloon occlusion (TBO) test emphasized the importance of intraoperative preservation of the ipsilateral ICA. A combination of both preoperative embolization and carotid stenting allowed a less hazardous radical resection of the CBT. An almost bloodless surgical field permitted meticulous dissection, hence reducing the risk of intraoperative vascular and nerve injury. Embolization and carotid stenting prior to surgical resection should be considered in cases with bilateral CBT or a skull base orientated high CBT, and for those with intracranial extension and patients who have failed the TBO test.

  18. Modulation of the hypoxic sensory response of the carotid body by 5-hydroxytryptamine: role of the 5-HT2 receptor.

    PubMed

    Jacono, F J; Peng, Y-J; Kumar, G K; Prabhakar, N R

    2005-02-15

    Previous studies have shown that glomus cells of the carotid body express 5-hydroxytryptamine (5-HT). The aim of this study was to elucidate the role of 5-HT on the hypoxic sensory response (HSR) of the carotid body. Sensory activity was recorded from multi-fiber (n=16) and single-fiber (n=8) preparations of ex vivo carotid bodies harvested from anesthetized, adult rats. 5-HT (3 microM) had no significant effect on the magnitude or on the onset of the HSR. However, 5-HT consistently prolonged the time necessary for the sensory activity to return to baseline following the termination of the hypoxic challenge. Ketanserin (40 microM), a 5-HT2 receptor antagonist completely prevented 5-HT-induced prolongation of the HSR, whereas had no effect on the control HSR (onset, magnitude, and time for decay without 5-HT). Carotid bodies expressed 5-HT, but hypoxia did not facilitate 5-HT release. These observations suggest that 5-HT is not critical for the HSR of the rat carotid body, but it modulates the dynamics of the HSR via its action on 5-HT2 receptors.

  19. Effects of low oxygen on the release of dopamine from the rabbit carotid body in vitro

    PubMed Central

    Fidone, S.; Gonzalez, C.; Yoshizaki, K.

    1982-01-01

    1. Rabbit carotid bodies were pre-loaded with [3H]dopamine (DA) synthesized from [3H]tyrosine and then mounted in a vertical drop-type superfusion chamber which permitted simultaneous collection of released [3H]DA and recording of chemoreceptor discharge from the carotid sinus nerve. 2. The time course of the spontaneous release of [3H]DA (superfusion with media equilibrated with 100% O2) in the presence of monoamine oxidase inhibitors exhibited two linear components, an initial steep phase followed after 3-4 hr by a later slower phase of release. 3. When a 5 min low O2 stimulus was delivered during the initial steep linear component of resting [3H]DA release, there was an abrupt increase in release, the magnitude of which was stimulus-dependent. 4. The efflux of total radioactivity from the preparation declined exponentially with time; under resting conditions it was principally non-metabolized [3H]tyrosine. During stimulation, however the efflux increased, and 60-80% of the radioactivity could be attributed to [3H]DA. 5. For a given low O2 stimulus, the ratio of [3H]DA release during the stimulus period over that in the preceding control period remained approximately the same throughout a single experiment. Ratios for different low O2 stimuli (50, 40, 30, 20, 10 and 0% O2 in N2) yielded a parabolic relationship when plotted against stimulus intensity. 6. Transection of the carotid sinus nerve or removal of the superior cervical ganglion 12-15 days prior to the experiment did not affect the release of [3H]DA at moderate stimulus intensities (superfusion with media equilibrated with 30% or 10% O2 in N2) but both procedures significantly depressed release at the highest stimulus intensity (100% N2). 7. Chemoreceptor discharge and [3H]DA release were simultaneously monitored in experiments using superfusion media free of monoamine oxidase inhibitors. In these experiments, the efflux of [3H]dihydroxyphenyl acetic acid (DOPAC) was also measured. The increase in peak

  20. 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

  1. 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.

  2. Impaired ventilatory acclimatization to hypoxia in female mice overexpressing erythropoietin: unexpected deleterious effect of estradiol in carotid bodies.

    PubMed

    Gassmann, Max; Pfistner, Christine; Doan, Van Diep; Vogel, Johannes; Soliz, Jorge

    2010-12-01

    Apart from enhancing the production of red blood cells, erythropoietin (Epo) alters the ventilatory response when oxygen supply is reduced. We recently demonstrated that Epo's beneficial effect on the ventilatory response to acute hypoxia is sex dependent, with female mice being better able to cope with reduced oxygenation. In the present work, we hypothesized that ventilatory acclimatization to chronic hypoxia (VAH) in transgenic female mice (Tg6) harboring high levels of Epo in the brain and blood will also be improved compared with wild-type (WT) animals. Surprisingly, VAH was blunted in Tg6 female mice. To define whether this phenomenon had a central (brain stem respiratory centers) and/or peripheral (carotid bodies) origin, a bilateral transection of carotid sinus nerve (chemodenervation) was performed. This procedure allowed the analysis of the central response in the absence of carotid body information. Interestingly, chemodenervation restored the VAH in Tg6 mice, suggesting that carotid bodies were responsible for the blunted response. Coherently with this observation, the sensitivity to oxygen alteration in arterial blood (Dejour test) after chronic hypoxia was lower in transgenic carotid bodies compared with the WT control. As blunted VAH occurred in female but not male transgenic mice, the involvement of sex female steroids was obvious. Indeed, measurement of sexual female hormones revealed that the estradiol serum level was 4 times higher in transgenic mice Tg6 than in WT animals. While ovariectomy decreased VAH in WT females, this treatment restored VAH in Tg6 female mice. In line with this observation, injections of estradiol in ovariectomized Tg6 females dramatically reduced the VAH. We concluded that during chronic hypoxia, estradiol in carotid bodies suppresses the Epo-mediated elevation of ventilation. Considering the increased application of recombinant Epo for a variety of disorders, our data imply the need to take the patient's hormonal status

  3. Signal transduction of aortic and carotid sinus baroreceptors is not modified by central command during spontaneous motor activity in decerebrate cats.

    PubMed

    Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Ishida, Tomoko; Idesako, Mitsuhiro; Liang, Nan

    2014-05-15

    Our laboratory has suggested that central command provides selective inhibition of the cardiomotor component of aortic baroreflex at the start of exercise, preserving carotid sinus baroreflex. It is postulated that central command may modify the signal transduction of aortic baroreceptors, so as to decrease aortic baroreceptor input to the cardiovascular centers, and, thereby, can cause the selective inhibition of aortic baroreflex. To test the hypothesis, we directly analyzed the responses in multifiber aortic nerve activity (AoNA) and carotid sinus nerve activity (CsNA) during spontaneous motor activity in decerebrate, paralyzed cats. The increases of 62-104% in mean AoNA and CsNA were found during spontaneous motor activity, in proportion to a rise of 35 ± 3 mmHg (means ± SE) in mean arterial blood pressure (MAP), and had an attenuating tendency by restraining heart rate (HR) at the lower intrinsic frequency of 154 ± 6 beats/min. Brief occlusion of the abdominal aorta was conducted before and during spontaneous motor activity to produce a mechanically evoked increase in MAP and, thereby, to examine the stimulus-response relationship of arterial baroreceptors. Although the sensitivity of the MAP-HR baroreflex curve was markedly blunted during spontaneous motor activity, the stimulus-response relationships of AoNA and CsNA were not influenced by spontaneous motor activity, irrespective of the absence or presence of the HR restraint. Thus, it is concluded that aortic and carotid sinus baroreceptors can code beat-by-beat blood pressure during spontaneous motor activity in decerebrate cats and that central command is unlikely to modulate the signal transduction of arterial baroreceptors.

  4. A pilot study of the body weight of pure-bred client-owned adult cats.

    PubMed

    Kienzle, Ellen; Moik, Katja

    2011-10-01

    A total of 539 pure-bred and seventy-five cats without a pedigree were weighed and scored at cat shows or in veterinary surgeries. Data from normal-weight cats with a body condition score (BCS) of 5 (ideal) were only used. Breeds were grouped into five classes. For female cats, the mean weight for these groups were as follows: very light (2.8 kg); light (3.2 kg); medium (3.5 kg); large (4.0 kg); giant (4.9) kg. For male cats, the corresponding values were 3.6, 4.2, 4.3, 5.1 and 6.1 kg. Siamese/Oriental Shorthair were identified as a very light breed, the Norwegian Forest and the Siberian Cat as a large breed and the Maine Coon as a giant breed. Males and females of the same breed did not always belong to the same class. In some breeds, individuals of the same sex were found in two different classes. The percentage of intact overweight cats (BCS >5) was low (7 % of intact males, 3 % of intact females). Incidence of overweight in neutered cats was 50 % in males and 38 % in females. Among pedigreed cats, there were differences in the incidence of overweight in neutered cats: high in Norwegian Forest Cats (males 75 %, females 50 %) and low in Siamese/Oriental Shorthair Cats (males 25 %, females 1 %). Cats with a BCS of 6, 7 and 8 had on average 120, 154 and 214 % of the normal weight of their breed, respectively.

  5. The von Hippel-Lindau Chuvash mutation in mice causes carotid-body hyperplasia and enhanced ventilatory sensitivity to hypoxia.

    PubMed

    Slingo, Mary E; Turner, Philip J; Christian, Helen C; Buckler, Keith J; Robbins, Peter A

    2014-04-01

    The hypoxia-inducible factor (HIF) family of transcription factors coordinates diverse cellular and systemic responses to hypoxia. Chuvash polycythemia (CP) is an autosomal recessive disorder in humans in which there is impaired oxygen-dependent degradation of HIF, resulting in long-term systemic elevation of HIF levels at normal oxygen tensions. CP patients demonstrate the characteristic features of ventilatory acclimatization to hypoxia, namely, an elevated baseline ventilation and enhanced acute hypoxic ventilatory response (AHVR). We investigated the ventilatory and carotid-body phenotype of a mouse model of CP, using whole-body plethysmography, immunohistochemistry, and electron microscopy. In keeping with studies in humans, CP mice had elevated ventilation in euoxia and a significantly exaggerated AHVR when exposed to 10% oxygen, with or without the addition of 3% carbon dioxide. Carotid-body immunohistochemistry demonstrated marked hyperplasia of the oxygen-sensing type I cells, and the cells themselves appeared enlarged with more prominent nuclei. This hypertrophy was confirmed by electron microscopy, which also revealed that the type I cells contained an increased number of mitochondria, enlarged dense-cored vesicles, and markedly expanded rough endoplasmic reticulum. The morphological and ultrastructural changes seen in the CP mouse carotid body are strikingly similar to those observed in animals exposed to chronic hypoxia. Our study demonstrates that the HIF pathway plays a major role, not only in regulating both euoxic ventilatory control and the sensitivity of the response to hypoxia, but also in determining the morphology of the carotid body.

  6. Retrobulbar lymphoma associated with a ballistic foreign body in a cat.

    PubMed

    Robat, C; Bemelmans, I; Marescaux, L

    2016-04-01

    A seven-year-old domestic shorthair cat, adopted 5 years previously with a corneal perforation of the left eye, was presented for investigation of a left orbital mass. Computed tomography revealed a metallic foreign body within a contrast-enhancing, heterogeneous orbital mass. Large cell lymphoma was diagnosed from a fine needle aspirate. The cat staged negatively and was treated with L-asparaginase, prednisolone and three fractions of radiation therapy. A rapid clinical remission was obtained and the cat remained in remission for 3 years after therapy. This is the first report of large cell lymphoma likely occurring secondary to a foreign body.

  7. 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

  8. 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

  9. Chemotransduction in the Carotid Body: K+ Current Modulated by Po2 in Type I Chemoreceptor Cells

    NASA Astrophysics Data System (ADS)

    Lopez-Barneo, Jose; Lopez-Lopez, Jose R.; Urena, Juan; Gonzalez, Constancio

    1988-07-01

    The ionic currents of carotid body type I cells and their possible involvement in the detection of oxygen tension (Po2) in arterial blood are unknown. The electrical properties of these cells were studied with the whole-cell patch clamp technique, and the hypothesis that ionic conductances can be altered by changes in Po2 was tested. The results show that type I cells have voltage-dependent sodium, calcium, and potassium channels. Sodium and calcium currents were unaffected by a decrease in Po2 from 150 to 10 millimeters of mercury, whereas, with the same experimental protocol, potassium currents were reversibly reduced by 25 to 50 percent. The effect of hypoxia was independent of internal adenosine triphosphate and calcium. Thus, ionic conductances, and particularly the O2-sensitive potassium current, play a key role in the transduction mechanism of arterial chemoreceptors.

  10. Role of the Carotid Body in the Pathophysiology of Heart Failure

    PubMed Central

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

    2013-01-01

    Important recent advances implicate a role of the carotid body (CB) chemoreflex in sympathetic and breathing dysregulation in several cardio-respiratory diseases, drawing renewed interest in its potential implications for clinical treatment. Evidence from both chronic heart failure (CHF) patients and animal models indicates that the CB chemoreflex is enhanced in CHF, and contributes to the tonic elevation in sympathetic nerve activity (SNA) and periodic breathing associated with the disease. Although this maladaptive change likely derives from altered function at all levels of the reflex arc, a change in afferent function of the CB is likely to be a main driving force. This review will focus on recent advances in our understanding of the pathophysiological mechanisms that alter CB function in CHF and their potential translational impact on treatment of chronic heart failure (CHF). PMID:23824499

  11. Changes in neurochemicals within the ventrolateral medullary respiratory column in awake goats after carotid body denervation

    PubMed Central

    Miller, Justin Robert; Neumueller, Suzanne; Muere, Clarissa; Olesiak, Samantha; Pan, Lawrence; Hodges, Matthew R.

    2013-01-01

    A current and major unanswered question is why the highly sensitive central CO2/H+ chemoreceptors do not prevent hypoventilation-induced hypercapnia following carotid body denervation (CBD). Because perturbations involving the carotid bodies affect central neuromodulator and/or neurotransmitter levels within the respiratory network, we tested the hypothesis that after CBD there is an increase in inhibitory and/or a decrease in excitatory neurochemicals within the ventrolateral medullary column (VMC) in awake goats. Microtubules for chronic use were implanted bilaterally in the VMC within or near the pre-Bötzinger Complex (preBötC) through which mock cerebrospinal fluid (mCSF) was dialyzed. Effluent mCSF was collected and analyzed for neurochemical content. The goats hypoventilated (peak +22.3 ± 3.4 mmHg PaCO2) and exhibited a reduced CO2 chemoreflex (nadir, 34.8 ± 7.4% of control ΔV̇E/ΔPaCO2) after CBD with significant but limited recovery over 30 days post-CBD. After CBD, GABA and glycine were above pre-CBD levels (266 ± 29% and 189 ± 25% of pre-CBD; P < 0.05), and glutamine and dopamine were significantly below pre-CBD levels (P < 0.05). Serotonin, substance P, and epinephrine were variable but not significantly (P > 0.05) different from control after CBD. Analyses of brainstem tissues collected 30 days after CBD exhibited 1) a midline raphe-specific reduction (P < 0.05) in the percentage of tryptophan hydroxylase–expressing neurons, and 2) a reduction (P < 0.05) in serotonin transporter density in five medullary respiratory nuclei. We conclude that after CBD, an increase in inhibitory neurotransmitters and a decrease in excitatory neuromodulation within the VMC/preBötC likely contribute to the hypoventilation and attenuated ventilatory CO2 chemoreflex. PMID:23869058

  12. Does Shamblin's classification predict postoperative morbidity in carotid body tumors? A proposal to modify Shamblin's classification.

    PubMed

    Luna-Ortiz, Kuauhyama; Rascon-Ortiz, Mario; Villavicencio-Valencia, Veronica; Herrera-Gomez, Angel

    2006-02-01

    The objective of this study was to analyze the possible correlation between Shamblin's classification and post-surgical morbidity in the treatment of carotid body tumors (CBTs). Seventy-two patients with carotid body tumors were seen over a 22-year period. Twenty-three patients were excluded as they did not comply with the criteria of the objectives. All patients were grouped according to Shamblin's classification. We propose a modification to this classification and make a comparison by analyzing the surgical time and bleeding, as well as the neurological and vascular damage. We resected 50 CBTs in 49 patients, ranging in age from 18 to 73 years. Three groups were formed: group I with 8 (16%) patients, group II with 17 (34%) and group III with 24 (49%). Post-surgical neurological damage was observed in one patient (12.5%) from group I, in six (35%) from group II and in nine patients (37.5%) from group III. Vascular sacrifice had to be performed in 21% of class II tumors and in 8.7% of class III. None of the class I tumors required vascular sacrifice. No statistically significant difference existed for vascular or neurological risk in relation to Shamblin's classification. However, when analyzed according to the classification proposed herein, there was a correlation between Shamblin's classification and vascular sacrifice (P =0.001). There was a statistically significant correlation between the original Shamblin and the modified Shamblin regarding surgical time and bleeding. Shamblin's classification predicts only vascular morbidity. Neurological morbidity is not reflected in it and only reflects the surgeon's experience with CBT resections. Surgical time and bleeding are directly related to the Shamblin as it reflects the size of tumors in relation to the blood vessels. Shamblin's classification must be modified to be more objective so that the international reports can accurately reflect the morbidity related to it.

  13. [Transformation of neuronal activity in the cat lateral geniculate body].

    PubMed

    Silakov, V L

    1976-05-01

    The neuronal activity transformations were studied in the cat LGB under the action of nembutal, light stimulation, and micropolarization of geniculate cells. The transformation of single spike activity into bursts was found to reflect the inhibitory state of the neurons. Their excitation entailed a reverse transformation. Short feed-back connections functioning within the microsystems of LGB neurons are supposed to underlie the transformations.

  14. 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

    2011-05-04

    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.

  15. Tracheobronchial foreign bodies in cats: a retrospective study of 12 cases.

    PubMed

    Leal, Rodolfo Oliveira; Bongrand, Yannick; Lepoutre, Julie Gallay; Gomes, Eymeric; Hernandez, Juan

    2017-02-01

    Objectives The aim of the study was to evaluate age, sex, breed, clinical signs, time between onset of signs and presentation, diagnostic procedures, method of extraction, location and nature of foreign bodies (FBs) in confirmed cases of tracheobronchial FBs in cats. We hypothesised that bronchoscopy was effective in extracting tracheobronchial FBs in cats. Methods A retrospective study was performed using clinical reports from three private practices in France between May 2009 and November 2014. Cats were included if an intraluminal tracheobronchial FB had been identified and extracted (either by bronchoscopy or surgery). Results Twelve cats (six male, six female) were included. Mean age was 3.75 ± 2.5 years. Coughing was the main complaint and was present in 9/12 (75%) of the cats. Thoracic radiographs were obtained in 12/12 cats (100%) and a FB was suspected in 11/12 (92%). Bronchoscopy was performed in all of the cats and enabled FB extraction in 10/12 (83%) of them. In 2/12 cats (17%), an additional surgical approach was required. In 6/12 (50%) cats, FBs were located in the trachea, while in 6/12 (50%) cats FBs were in the bronchial tree, particularly in the right caudal bronchus (4/6; 66%). Seven of 12 (58%) FBs were vegetal in nature, 3/12 (25%) were mineral and 2/12 (17%) were undetermined. All the mineral FBs were extracted from the trachea, while the majority of the vegetal ones (5/7; 71%) were found in the bronchi. Conclusions and relevance Feline respiratory FBs can be found in the trachea and in the bronchial tree, particularly in the right caudal bronchus. Vegetal FBs tend to migrate through the bronchial tree, whereas mineral ones tend to lodge in the trachea. Bronchoscopy seems to be a highly effective procedure for the extraction of tracheobronchial FBs in cats.

  16. Overt and subclinical baroreflex dysfunction following bilateral carotid body tumor resection: pathophysiology, diagnosis, and implications for management.

    PubMed

    Ghali, Michael G Z; Srinivasan, Visish M; Hanna, Ehab; DeMonte, Franco

    2017-02-25

    Carotid body paragangliomas are rare, usually benign, tumors arising from glomus cells of the carotid body. Bilateral involvement is present in ∼5% of sporadic cases and up to one-third of familial cases. In the majority of patients undergoing bilateral resection of carotid body tumors (CBTs), a condition known as baroreflex failure syndrome (BFS) develops following resection of the second tumor characterized by headache, anxiety, emotional lability, orthostatic lightheadedness, hypertension, and tachycardia. This is believed to result from damage to the carotid baroreceptor apparatus. Patients without overt cardiovascular abnormalities may have subclinical baroreceptor dysfunction evident only on specific testing, measuring HR and sympathetic nerve responses to baro-loading (eg., phenylephrine) and baro-unloading (e.g., Valsalva maneuver). Given the high incidence of BFS in patients undergoing bilateral resection of CBTs, it is suggested that operation be limited to unilateral resection of the dominant/symptomatic lesion and non-surgical intervention (i.e., embolization, radiotherapy) on the contralateral side. Alternatively, refinement of surgical technique to prevent injury to elements of the baroreceptor apparatus may prevent this unfortunate complication of bilateral tumor resection. We present a case of a 16 year old girl with bilateral jugular vagale and carotid body tumors who developed hypertension following surgical resection of her left jugular vagale tumor and worsening of hypertension concurrent with progression, eventually requiring intensity-modulated radiation therapy and a resection for significant progression of her left jugular vagale tumor. Our case illustrates the generalizability of BFS to patients with tumors involving the vagal baro-afferent fibers.

  17. Influence of age, body mass index, and blood pressure on the carotid intima-media thickness in normotensive and hypertensive patients.

    PubMed

    Honzikova, Natasa; Labrova, Ruzena; Fiser, Bohumil; Maderova, Eva; Novakova, Zuzana; Zavodna, Eva; Semrad, Borivoj

    2006-10-01

    We investigated whether body mass index and blood pressure have an additive influence on the carotid intima-media thickness (IMT). In 27 patients treated for hypertension (47.2+/-8.7 years) and 23 normotensive subjects (44.1+/-8.1 years), 24-h recording of blood pressure was performed. The carotid IMT was determined by ultrasonography and baroreflex sensitivity by a spectral method from 5-min recordings of blood pressure. Significant differences between hypertensive and normotensive subjects were observed for carotid IMT (0.60+/-0.08 vs. 0.51+/-0.07 mm; p<0.001) and baroreflex sensitivity (3.5+/-1.8 vs. 5.6+/-2.1 ms/mm Hg; p<0.001). Hierarchical multiple regression analysis (p<0.01) showed that carotid IMT was positively correlated with age (p<0.001) and body mass index (p<0.05) in normotensive subjects. The increased carotid IMT in hypertensive patients was not additively influenced by either age or body mass index. Baroreflex sensitivity decreased with age (p<0.01) and with carotid IMT (p<0.05) in normotensive subjects only. Multiregression analysis showed that an additive influence of age and body mass index on the development of carotid IMT is essential only in normotensive subjects. In hypertensive subjects the influence of blood pressure predominates, as documented by a comparison of the carotid IMT between hypertensive and normotensive subjects.

  18. The role of nitric oxide in carotid chemoreception.

    PubMed

    Wang, Z Z; Dinger, B G; Stensaas, L J; Fidone, S J

    1995-01-01

    Immunocytochemical and histochemical studies of cat and rat carotid bodies have revealed a plexus of nitric oxide synthase (NOS)-positive nerve fibers associated with lobules of chemosensory type I cells as well as with the carotid body vasculature. NOS-positive fibers originate from (1) autonomic neurons located in the carotid body and distributed along the carotid sinus nerve (CNS) and IXth cranial nerve which terminate in the adventitial layer of carotid body blood vessels, and (2) from unipolar sensory neurons of the petrosal (IXth nerve) ganglion. Carotid bodies incubated with the NO precursor, 3H-arginine, yield 3H-citrulline, the detectable coproduct of NO synthesis. Furthermore, electrical stimulation of the CNS or exposure of carotid bodies to hypoxic incubation media elevates 3H-citrulline formation. Millimolar concentrations of L-arginine inhibit chemoreceptor activity evoked by hypoxia, an effect which is reversed by the specific NOS antagonist, L-NG-nitroarginine methylester (L-NAME, 0.1 mM). Electrical stimulation of CNS C fibers elevates cyclic GMP in the carotid body vasculature and lobules of type I cells. Cyclic GMP production is reduced during stimulation in the presence of L-NAME, a finding consistent with the known ability of NO to activate a soluble form of guanylate cyclase. Further studies showed that brief (< 1 min) stimulation of CNS C fibers inhibits basal chemoreceptor discharge in a perfused/superfused in vitro carotid body preparation, whereas prolonged (> 5 min) stimulation is required to inhibit the response to hypoxia. The inhibitory effect is reversed by L-NAME. Our combined anatomical, neuropharmacological and electrophysiological data suggest that NO plays a dual role in mediating CNS inhibition, one via its actions on the organ's vasculature and the other through direct effects on the chemosensory type I cells. The former pathway involves cholinergic/NOS presumptive parasympathetic autonomic neurons, while the latter may be

  19. Dosing obese cats based on body weight spuriously affects some measures of glucose tolerance.

    PubMed

    Reeve-Johnson, M K; Rand, J S; Anderson, S T; Appleton, D J; Morton, J M; Vankan, D

    2016-10-01

    The primary objective was to investigate whether dosing glucose by body weight results in spurious effects on measures of glucose tolerance in obese cats because volume of distribution does not increase linearly with body weight. Healthy research cats (n = 16; 6 castrated males, 10 spayed females) were used. A retrospective study was performed using glucose concentration data from glucose tolerance and insulin sensitivity tests before and after cats were fed ad libitum for 9 to 12 mo to promote weight gain. The higher dose of glucose (0.5 vs 0.3 g/kg body weight) in the glucose tolerance tests increased 2-min glucose concentrations (P < 0.001), and there was a positive correlation between 2-min and 2-h glucose (r = 0.65, P = 0.006). Two-min (P = 0.016 and 0.019, respectively), and 2-h (P = 0.057 and 0.003, respectively) glucose concentrations, and glucose half-life (T1/2; P = 0.034 and <0.001 respectively) were positively associated with body weight and body condition score. Glucose dose should be decreased by 0.05 g for every kg above ideal body weight. Alternatively, for every unit of body condition score above 5 on a 9-point scale, observed 2-h glucose concentration should be adjusted down by 0.1 mmol/L. Dosing glucose based on body weight spuriously increases glucose concentrations at 2 h in obese cats and could lead to cats being incorrectly classified as having impaired glucose tolerance. This has important implications for clinical studies assessing the effect of interventions on glucose tolerance when lean and obese cats are compared.

  20. 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

  1. 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.

  2. Effect of hyperoxic exposure during early development on neurotrophin expression in the carotid body and nucleus tractus solitarii

    PubMed Central

    Chavez-Valdez, Raul; Mason, Ariel; Nunes, Ana R.; Northington, Frances J.; Tankersley, Clarke; Ahlawat, Rajni; Johnson, Sheree M.

    2012-01-01

    Synaptic activity can modify expression of neurotrophins, which influence the development of neuronal circuits. In the newborn rat, early hyperoxia silences the synaptic activity and input from the carotid body, impairing the development and function of chemoreceptors. The purpose of this study was to determine whether early hyperoxic exposure, sufficient to induce hypoplasia of the carotid body and decrease the number of chemoafferents, would also modify neurotrophin expression within the nucleus tractus solitarii (nTS). Rat pups were exposed to hyperoxia (fraction of inspired oxygen 0.60) or normoxia until 7 or 14 days of postnatal development (PND). In the carotid body, hyperoxia decreased brain-derived neurotrophic factor (BDNF) protein expression by 93% (P = 0.04) after a 7-day exposure, followed by a decrease in retrogradely labeled chemoafferents by 55% (P = 0.004) within the petrosal ganglion at 14 days. Return to normoxia for 1 wk after a 14-day hyperoxic exposure did not reverse this effect. In the nTS, hyperoxia for 7 days: 1) decreased BDNF gene expression by 67% and protein expression by 18%; 2) attenuated upregulation of BDNF mRNA levels in response to acute hypoxia; and 3) upregulated p75 neurotrophic receptor, truncated tropomyosin kinase B (inactive receptor), and cleaved caspase-3. These effects were not observed in the locus coeruleus (LC). Hyperoxia for 14 days also decreased tyrosine hydroxylase levels by 18% (P = 0.04) in nTS but not in the LC. In conclusion, hyperoxic exposure during early PND reduces neurotrophin levels in the carotid body and the nTS and shifts the balance of neurotrophic support from prosurvival to proapoptotic in the nTS, the primary brain stem site for central integration of sensory and autonomic inputs. PMID:22422797

  3. The carotid body in the duck and the consequences of its denervation upon the cardiac responses to immersion

    PubMed Central

    Jones, D. R.; Purves, M. J.

    1970-01-01

    1. The anatomy of the carotid body and its afferent nerve supply was studied in the duck and a method of denervating the carotid body which ensures a satisfactory post-operative course is described. 2. The effect of denervating the carotid body upon the cardiac response to immersion of the head in water was studied in ten ducks which at the time of the test were unanaesthetized. 3. When the nerves were intact, immersion of the head caused a fall in heart rate after a latent period of between 1 and 9 sec to an average of 24% of the resting rate after 30 sec. Simultaneous measurement of arterial oxygen tension (Pa, O2) in the brachiocephalic artery showed a rapid initial fall during the initial 10 sec from control levels, 93-103 mm Hg, to between 42 and 47 mm Hg, followed by a gradual fall of 3-5 mm Hg for each subsequent 30 sec period of submergence. 4. Following carotid body denervation, the latent period before heart rate started to fall was no different from control but the average fall in heart rate was now to 90% of the resting rate and brachiocephalic Pa. O2 continued to fall steadily during submergence reaching levels of between 10 and 21 mm Hg by the end of the second minute. 5. Stimulation of the central end of branches of the IXth (glossopharyngeal) nerve supplying the glottis caused apnoea and bradycardia. 6. It is concluded that apnoea and bradycardia during submergence in the duck is initiated reflexly from receptors in the nares, pharynx and glottis but that the profound degree of bradycardia and mechanisms which maintain a relatively high Pa, O2 are regulated by peripheral chemoreceptor activity. ImagesPlate 1 PMID:5501002

  4. Non-additive interactions between mitochondrial complex IV blockers and hypoxia in rat carotid body responses

    PubMed Central

    Donnelly, David F; Kim, Insook; Mulligan, Eileen M; Carroll, John L

    2013-01-01

    The metabolic hypothesis of carotid body chemoreceptor hypoxia transduction proposes an impairment of ATP production as the signal for activation. We hypothesized that mitochondrial complex IV blockers and hypoxia would act synergistically in exciting afferent nerve activity. Following a pretreatment with low dosage sodium cyanide (10-20μM), the hypoxia-induced nerve response was significantly reduced along with hypoxia-induced catecholamine release. However, in isolated glomus cells, the intracellular calcium response was enhanced as initially predicted. This suggests a cyanide-mediated impairment in the step between the glomus cell intracellular calcium rise and neurotransmitter release from secretory vesicles. Administration of a PKC blocker largely reversed the inhibitory actions of cyanide on the neural response. We conclude that the expected synergism between cyanide and hypoxia occurs at the level of glomus cell intracellular calcium but not at downstream steps due to a PKC-dependent inhibition of secretion. This suggests that at least one regulatory step beyond the glomus cell calcium response may modulate the magnitude of chemoreceptor responsiveness. PMID:24096081

  5. Carotid body: a new target for rescuing neural control of cardiorespiratory balance in disease.

    PubMed

    Fitzgerald, Robert S

    2014-01-01

    Significant insight into the mechanisms involved in chronic heart failure (CHF) have been provided by Schultz and his associates at the University of Nebraska Medical Center with the use of pacing-induced heart failure rabbits. Critical among the CHF mechanisms was the role of the carotid body (CB). The stimulated CB produces a wide array of systemic reflex responses; certainly those in the cardiopulmonary (CP) system are the most important in CHF. This generates a question as to whether the CB could serve as a target for some kind of treatment to reestablish control of cardiorespiratory balance in CHF. Any treatment would have to be based on a solid understanding of the mechanisms of chemosensing by the CB as well as the transducing of that sensing into neural activity sent to the medullary centers and regions of autonomic outflow to the periphery. Two avenues of treatment could be to (1) silence or attenuate the CB's neural output pharmacologically and (2) excise the CBS. There is a long history of CB removal mostly as a remedy for chronic obstructive lung disease. Results have been inconclusive as to the effectiveness of this procedure. But if carefully planned, the procedure might be a helpful treatment.

  6. 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.

  7. 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

  8. Plasticity in the brain: influence of bilateral carotid body resection (bCBR) on central CO2 sensitivity.

    PubMed

    Dahan, Albert; Sarton, Elise; Teppema, Luc

    2008-01-01

    We investigated the effect of bilateral carotid body resection (bCBR) in a patient with bilateral carotid body tumors on central CO2 sensitivity. We applied multiple square-wave changes in end-tidal CO2 and measured ventilation before the first surgery and at regular intervals for 3 years after surgery. The data were analyzed using a two-compartment model of the ventilatory control system. bCBR resulted in the loss of the fast response to CO2, and a sharp reduction in the magnitude of central CO2 sensitivity (a reduction of about 80% within 3 months after bCBR). Central CO2 sensitivity gradually increased to pre-operative values within 2 years after surgery. These observations are a strong indication for (1) the existence of a tonic influence from the peripheral chemoreceptors of the carotid bodies on central CO2 drive; (2) absence of any recovery of the peripheral drive after bCBR; and (3) neural plasticity causing the regeneration of central drive after bCBR.

  9. Color Doppler Ultrasound in Diagnosis and Assessment of Carotid Body Tumors: Comparison with Computed Tomography Angiography.

    PubMed

    Jin, Zhan-Qiang; He, Wen; Wu, Dong-Fang; Lin, Mei-Ying; Jiang, Hua-Tang

    2016-09-01

    A carotid body tumor (CBT) is a rare, non-chromaffin paraganglioma, and its diagnosis mainly depends on imaging modalities. The aim of this study was to investigate the ability of color Doppler ultrasound (CDU) in the diagnosis and assessment of CBT based on computed tomography (CT). We retrospectively reviewed the CDU and CT features of 49 consecutive CBTs and 23 schwannomas from 67 patients and compared these findings with surgical resection specimens. The mean size of CBT lesions on ultrasound scans and CT angiography (CTA) was 3.24 cm ± 0.82 cm (range, 1.6-5.2 cm) and 3.84 cm ± 1.08 cm (range, 1.8-6.8 cm), respectively, which had statistically significant difference (t = 9.815, p = 0.000). The vascularity of CBT lesions was richer than that of schwannoma lesions (p < 0.05). Intra-lesional vascularities feeding CBT mostly arose from the external carotid artery and had spectrum characteristics including low velocity and resistance. Peak systolic velocity (PSV) and resistance index (RI) of the vasa vasorum were 39.8 cm/s ± 19.8 cm/s and 0.54 ± 0.06, respectively. There was the correlation between CTA and CDU in identifying Shamblin type I CBT lesions, while CTA technique was superior for CDU, identifying Shamblin type II and III CBT lesions. Accuracy, specificity and sensitivity of CDU in diagnosing CBTs were 87.5% (63 of 72), 82.6% (19 of 23) and 89.8% (44 of 49), respectively. Both accuracy and sensitivity of CTA in diagnosing CBTs were 100%. CDU can be useful for assessment of Shamblin's type and intra-lesional blood flow of CBTs before its metastases, while CT imaging can reveal the relationship between lesions and adjacent arteries, as well as the involvement of the skull base. CDU combined with CT imaging can be used as an optimal detection modality for the assessment and management of CBT.

  10. 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

  11. Management of dogs and cats with endotracheal tube tracheal foreign bodies

    PubMed Central

    Nutt, Laura K.; Webb, Jinelle A.; Prosser, Kirsten J.; Defarges, Alice

    2014-01-01

    Two cats and 3 dogs were treated for an endotracheal tube tracheal foreign body (ETFB) during recovery from general anesthesia. Bronchoscopy was used to remove the ETFB. Animals were clinically normal at discharge. While rare, ETFB can occur upon recovery from anesthesia. Bronchoscopy is an effective way to remove ETFB. PMID:24891640

  12. Variations in leopard cat (Prionailurus bengalensis) skull morphology and body size: sexual and geographic influences

    PubMed Central

    Oliveira, Luiz Flamarion B.

    2015-01-01

    The leopard cat, Prionailurus bengalensis (Kerr, 1792), is one of the most widespread Asian cats, occurring in continental eastern and southeastern Asia. Since 1929, several studies have focused on the morphology, ecology, and taxonomy of leopard cats. Nevertheless, hitherto there has been no agreement on basic aspects of leopard cat biology, such as the presence or absence of sexual dimorphism, morphological skull and body differences between the eleven recognized subspecies, and the biogeography of the different morphotypes. Twenty measurements on 25 adult leopard cat skulls from different Asian localities were analyzed through univariate and multivariate statistical approaches. Skull and external body measurements from studies over the last 77 years were assembled and organized in two categories: full data and summary data. Most of this database comprises small samples, which have never been statistically tested and compared with each other. Full data sets were tested with univariate and multivariate statistical analyses; summary data sets (i.e., means, SDs, and ranges) were analyzed through suitable univariate approaches. The independent analyses of the data from these works confirmed our original results and improved the overview of sexual dimorphism and geographical morphological variation among subspecies. Continental leopard cats have larger skulls and body dimensions. Skulls of Indochinese morphotypes have broader and higher features than those of continental morphotypes, while individuals from the Sunda Islands have skulls with comparatively narrow and low profiles. Cranial sexual dimorphism is present in different degrees among subspecies. Most display subtle sex-related variations in a few skull features. However, in some cases, sexual dimorphism in skull morphology is absent, such as in P. b. sumatranus and P. b. borneoensis. External body measurement comparisons also indicate the low degree of sexual dimorphism. Apart from the gonads, the longer hind

  13. Body size and metabolic differences in Maine Coon cats with and without hypertrophic cardiomyopathy.

    PubMed

    Freeman, Lisa M; Rush, John E; Meurs, Kathryn M; Bulmer, Barret J; Cunningham, Suzanne M

    2013-02-01

    An interplay between growth, glucose regulation and hypertrophic cardiomyopathy (HCM) may exist, but has not been studied in detail. The purpose of this study was to characterize morphometric features, insulin-like growth factor-1 (IGF-1) and glucose metabolism in Maine Coon cats with HCM. Body weight, body condition score (BCS), head length and width, and abdominal circumference were measured in Maine Coon cats >2 years of age. Echocardiography and thoracic radiography (for measurement of humerus length, and fourth and twelfth vertebrae length) were also performed. Blood was collected for biochemistry profile, DNA testing, insulin and IGF-1. Sixteen of 63 cats had HCM [myosin binding protein C (MYBPC)+, n = 3 and MYBPC-, n = 13] and 47/63 were echocardiographically normal (MYBPC+, n = 17 and MYBPC-, n = 30). There were no significant differences in any measured parameter between MYBPC+ and MYBPC- cats. Cats with HCM were significantly older (P <0.001), heavier (P = 0.006), more obese (P = 0.008), and had longer humeri (P = 0.02) compared with the HCM- group. Cats with HCM also had higher serum glucose (P = 0.01), homeostasis model assessment (HOMA) and IGF-1 (P = 0.01) concentrations, were from smaller litters (P = 0.04), and were larger at 6 months (P = 0.02) and at 1 year of age (P = 0.03). Multivariate analysis revealed that age (P <0.001), BCS (P = 0.03) and HOMA (P = 0.047) remained significantly associated with HCM. These results support the hypothesis that early growth and nutrition, larger body size and obesity may be environmental modifiers of genetic predisposition to HCM. Further studies are warranted to evaluate the effects of early nutrition on the phenotypic expression of HCM.

  14. 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

  15. Ionic mechanisms for the transduction of acidic stimuli in rabbit carotid body glomus cells.

    PubMed Central

    Rocher, A; Obeso, A; Gonzalez, C; Herreros, B

    1991-01-01

    1. The release of [3H]dopamine (DA) in response to inhibition of the Na+ pump or to intracellular acid load was studied in rabbit carotid bodies (CB) previously incubated with the precursor [3H]tyrosine. The ionic requirements of the release response and the involvement of specific ion transport systems were investigated. 2. Inhibition of the Na+ pump, by incubating the CB with ouabain or in K(+)-free medium, evokes a DA release response which requires the presence of Na+ and Ca2+ in the medium and is insensitive to nisoldipine. This suggests that the response is triggered by entry of external Ca2+ through Na(+)-Ca2+ exchange, a consequence of the increase in intracellular Na+ resulting from inhibition of the pump. 3. Incubation of the CB in medium equilibrated with 20% CO2 at pH 6.6, or in medium containing the protonophore dinitrophenol (DNP) or the weak acid propionate, elicits a DA release response which requires also the presence of Na+ and Ca2+ in the medium and is insensitive to dihydropyridines. 4. Ethylisopropylamiloride (EIPA), an inhibitor of the Na(+)-H+ exchanger, markedly decreases the release response elicited by DNP or propionate in bicarbonate-free medium, but has not any effect in bicarbonate-buffered medium. In the latter condition, the EIPA-insensitive release of DA is inhibited by reducing the HCO3- concentration in the medium to 2 mM or by removal of Cl-, suggesting that in bicarbonate-buffered medium a Na(+)-dependent HCO3(-)-Cl- exchanger is involved in the release response. 5. It is concluded that the release of DA by the chemoreceptor cells in response to acidic stimulation is triggered by entry of external Ca2+ through Na(+)-Ca2+ exchange. This exchange is promoted by the increase of intracellular Na+ that results from the operation of Na(+)-coupled H(+)-extruding mechanisms activated by the acid load. PMID:1668755

  16. Glycogen metabolism protects against metabolic insult to preserve carotid body function during glucose deprivation.

    PubMed

    Holmes, Andrew P; Turner, Philip J; Carter, Paul; Leadbeater, Wendy; Ray, Clare J; Hauton, David; Buckler, Keith J; Kumar, Prem

    2014-10-15

    The view that the carotid body (CB) type I cells are direct physiological sensors of hypoglycaemia is challenged by the finding that the basal sensory neuronal outflow from the whole organ is unchanged in response to low glucose. The reason for this difference in viewpoint and how the whole CB maintains its metabolic integrity when exposed to low glucose is unknown. Here we show that, in the intact superfused rat CB, basal sensory neuronal activity was sustained during glucose deprivation for 29.1 ± 1.2 min, before irreversible failure following a brief period of excitation. Graded increases in the basal discharge induced by reducing the superfusate PO2 led to proportional decreases in the time to the pre-failure excitation during glucose deprivation which was dependent on a complete run-down in glycolysis and a fall in cellular energy status. A similar ability to withstand prolonged glucose deprivation was observed in isolated type I cells. Electron micrographs and immunofluorescence staining of rat CB sections revealed the presence of glycogen granules and the glycogen conversion enzymes glycogen synthase I and glycogen phosphorylase BB, dispersed throughout the type I cell cytoplasm. Furthermore, pharmacological attenuation of glycogenolysis and functional depletion of glycogen both significantly reduced the time to glycolytic run-down by ∼33 and 65%, respectively. These findings suggest that type I cell glycogen metabolism allows for the continuation of glycolysis and the maintenance of CB sensory neuronal output in periods of restricted glucose delivery and this may act as a key protective mechanism for the organ during hypoglycaemia. The ability, or otherwise, to preserve energetic status may thus account for variation in the reported capacity of the CB to sense physiological glucose concentrations and may even underlie its function during pathological states associated with augmented CB discharge.

  17. Glucose sensing by carotid body glomus cells: potential implications in disease

    PubMed Central

    Gao, Lin; Ortega-Sáenz, Patricia; García-Fernández, María; González-Rodríguez, Patricia; Caballero-Eraso, Candela; López-Barneo, José

    2014-01-01

    The carotid body (CB) is a key chemoreceptor organ in which glomus cells sense changes in blood O2, CO2, and pH levels. CB glomus cells have also been found to detect hypoglycemia in both non-primate mammals and humans. O2 and low-glucose responses share a common final pathway involving membrane depolarization, extracellular calcium influx, increase in cytosolic calcium concentration, and neurotransmitter secretion, which stimulates afferent sensory fibers to evoke sympathoadrenal activation. On the other hand, hypoxia and low glucose induce separate signal transduction pathways. Unlike O2 sensing, the response of the CB to low glucose is not altered by rotenone, with the low glucose-activated background cationic current unaffected by hypoxia. Responses of the CB to hypoglycemia and hypoxia can be potentiated by each other. The counter-regulatory response to hypoglycemia by the CB is essential for the brain, an organ that is particularly sensitive to low glucose. CB glucose sensing could be altered in diabetic patients, particularly those under insulin treatment, as well as in other medical conditions such as sleep apnea or obstructive pulmonary diseases, where chronic hypoxemia presents with plastic modifications in CB structure and function. The current review will focus on the following main aspects: (1) the CB as a low glucose sensor in both in vitro and in vivo models; (2) molecular and ionic mechanisms of low glucose sensing by glomus cells, (3) the interplay between low glucose and O2 sensing in CB, and (4) the role of CB low glucose sensing in the pathophysiology of cardiorespiratory and metabolic diseases, and how this may serve as a potential therapeutic target. PMID:25360117

  18. Expression of nitric oxide-containing structures in the rat carotid body.

    PubMed

    Atanasova, Dimitrinka Y; Dimitrov, Nikolay D; Lazarov, Nikolai E

    2016-10-01

    The carotid body (CB) is a major peripheral arterial chemoreceptor organ that evokes compensatory reflex responses so as to maintain gas homeostasis. It is dually innervated by sensory fibers from petrosal ganglion (PG) neurons, and autonomic fibers from postganglionic sympathetic neurons of the superior cervical ganglion (SCG) and parasympathetic vasomotor fibers of intrinsic ganglion cells in the CB. The presence of nitric oxide (NO), a putative gaseous neurotransmitter substance in a number of neuronal and non-neuronal structures, was examined in the CB, PG and SCG of the rat using nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry, nitric oxide synthase (NOS) immunohistochemistry and retrograde tracing. One week after injecting the retrograde tracer Fast Blue (FB) in the CB, we found that a subset of perikarya in the caudal portions of the PG and SCG were FB-labeled. Histochemistry and immunohistochemistry revealed that the majority of large- and medium-sized PG and SCG cells were NADPH-d positive and displayed a strong NOS immunostaining. We also observed that many varicose nerve fibers penetrating the CB and enveloping the glomus cells and blood vessels were NADPH-d reactive and expressed the constitutive isoforms of NOS, nNOS and eNOS. In addition, some autonomic microganglion cells embedded within, or located at the periphery of the CB, and not glomus or sustentacular cells were nNOS-immunopositive while CB microvasculature expressed eNOS. The present results suggest that NO is a transmitter in the autonomic nerve endings supplying the CB and is involved in efferent chemoreceptor inhibition by a dual mechanism.

  19. Glucose sensing by carotid body glomus cells: potential implications in disease.

    PubMed

    Gao, Lin; Ortega-Sáenz, Patricia; García-Fernández, María; González-Rodríguez, Patricia; Caballero-Eraso, Candela; López-Barneo, José

    2014-01-01

    The carotid body (CB) is a key chemoreceptor organ in which glomus cells sense changes in blood O2, CO2, and pH levels. CB glomus cells have also been found to detect hypoglycemia in both non-primate mammals and humans. O2 and low-glucose responses share a common final pathway involving membrane depolarization, extracellular calcium influx, increase in cytosolic calcium concentration, and neurotransmitter secretion, which stimulates afferent sensory fibers to evoke sympathoadrenal activation. On the other hand, hypoxia and low glucose induce separate signal transduction pathways. Unlike O2 sensing, the response of the CB to low glucose is not altered by rotenone, with the low glucose-activated background cationic current unaffected by hypoxia. Responses of the CB to hypoglycemia and hypoxia can be potentiated by each other. The counter-regulatory response to hypoglycemia by the CB is essential for the brain, an organ that is particularly sensitive to low glucose. CB glucose sensing could be altered in diabetic patients, particularly those under insulin treatment, as well as in other medical conditions such as sleep apnea or obstructive pulmonary diseases, where chronic hypoxemia presents with plastic modifications in CB structure and function. The current review will focus on the following main aspects: (1) the CB as a low glucose sensor in both in vitro and in vivo models; (2) molecular and ionic mechanisms of low glucose sensing by glomus cells, (3) the interplay between low glucose and O2 sensing in CB, and (4) the role of CB low glucose sensing in the pathophysiology of cardiorespiratory and metabolic diseases, and how this may serve as a potential therapeutic target.

  20. 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

  1. [Effect of mammillary body ablation on extinctive inhibition in cats].

    PubMed

    Voronin, L G; Nikol'skaia, K A

    1978-01-01

    Chronic extinction of chain closed conditioned reflex in intact rabbits took five to six days. The order of extinction of the reflex links was as follows: the nearer to reinforcement the link of the chain, the sooner it was inhibited. In the course of extinction different "compensatory" movements appeared with a high frequency. Unlike the conditioned movements they were not fully extinguished: in the rest periods (lying for 4 to 10 min.), running and sniffing took place 4 to 8 times in the session. After the ablation of the mammilary bodies, extinctive inhibition was developing slower (9 to 13 days) than in the norm. The order of extinction became reverse: the nearer the link of the chain to reinforcement, the greater the difficulty of inhibition. The appearance of "compensatory" movements sharply differed from the norm. The general behaviour of the operated rabbits was peculiar in that during extinction of conditioned movements the short periods of rest (1 to 3 min.) alternated with running, sitting, scratching, washing, etc.

  2. Reduced to oxidized glutathione ratios and oxygen sensing in calf and rabbit carotid body chemoreceptor cells

    PubMed Central

    Sanz-Alfayate, G; Obeso, A; Agapito, M T; González, C

    2001-01-01

    The aim of this work was to test the redox hypotheses of O2 chemoreception in the carotid body (CB). They postulate that hypoxia alters the levels of reactive oxygen species (ROS) and the ratio of reduced to oxidized glutathione (GSH/GSSG), causing modifications to the sulfhydryl groups/disulfide bonds of K+ channel proteins, which leads to the activation of chemoreceptor cells. We found that the GSH/GSSG ratio in normoxic calf CB (30.14 ± 4.67; n = 12) and hypoxic organs (33.03 ± 6.88; n = 10), and the absolute levels of total glutathione (0.71 ± 0.07 nmol (mg tissue)−1, normoxia vs. 0.76 ± 0.07 nmol (mg tissue)−1, hypoxia) were not statistically different. N-Acetylcysteine (2 mm; NAC), a precursor of glutathione and ROS scavenger, increased normoxic glutathione levels to 1.03 ± 0.06 nmol (mg tissue)−1 (P < 0.02) and GSH/GSSG ratios to 59.05 ± 5.05 (P < 0.001). NAC (20 μm–10 mm) did not activate or inhibit chemoreceptor cells as it did not alter the normoxic or the hypoxic release of 3H-catecholamines (3H-CAs) from rabbit and calf CBs whose CA deposits had been labelled by prior incubation with the natural CA precursor 3H-tyrosine. NAC (2 mm) was equally ineffective in altering the release of 3H-CAs induced by stimuli (high external K+ and ionomycin) that bypass the initial steps of the hypoxic cascade of activation of chemoreceptor cells, thereby excluding the possibility that the lack of effect of NAC on normoxic and hypoxic release of 3H-CAs results from a concomitant alteration of Ca2+ channels or of the exocytotic machinery. The present findings do not support the contention that O2 chemoreception in the CB is linked to variations in the GSH/GSSG quotient as the redox models propose. PMID:11711574

  3. 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

  4. Respiratory Adaptation to Acute Metabolic Acidosis in Goats with Ablated Carotid Bodies,

    DTIC Science & Technology

    1982-06-03

    values. DISCUSSION We have shown in a previous communication (26) that the goats used in the present study were deprived of peripheral chemoreception ...was manifest in the chemodenervated awake goats. This is in agreement with findings in anesthetized cats (14) and in anesthetized (12) and awake dogs...anesthetized cats by Katsaros (14). It appears that a respiratory adaptation to AMA, mani- fest in lowering the resting PaCO 2 and in shifting CO2

  5. Whole body computed tomographic characteristics of skeletal and cardiac muscular metastatic neoplasia in dogs and cats.

    PubMed

    Vignoli, Massimo; Terragni, Rossella; Rossi, Federica; Frühauf, Lukas; Bacci, Barbara; Ressel, Lorenzo; Capitani, Ombretta; Marconato, Laura

    2013-01-01

    Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT-guided tru-cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty-one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well-demarcated, oval-to-round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.

  6. K+ channels in O2 sensing and postnatal development of carotid body glomus cell response to hypoxia

    PubMed Central

    Kim, Donghee

    2016-01-01

    The sensitivity of carotid body chemoreceptors to hypoxia is low just after birth and increases over the first few weeks of the postnatal period. At present, it is believed that the hypoxia-induced excitation of carotid body glomus cells begins with the inhibition of the outward K+ current via one or more O2 sensors. Although the nature of the O2 sensors and their signals that inhibit the K+ current are not well defined, studies suggest that the postnatal maturation of the glomus cell response to hypoxia is largely due to the increased sensitivity of K+ channels to hypoxia. As KV, BK and TASK channels that are O2-sensitive contribute to the K+ current, it is important to identify the O2 sensor and the signaling molecule for each of these K+ channels. Various O2 sensors (mitochondrial hemeprotein, hemeoxygenase-2, NADPH oxidase) and associated signals have been proposed to mediate the inhibition of K+ channels by hypoxia. Studies suggest that a mitochondrial hemeprotein is likely to serve as an O2 sensor for K+ channels, particularly for TASK, and that multiple signals may be involved. Thus, changes in the sensitivity of the mitochondrial O2 sensor to hypoxia, the sensitivity of K+ channels to signals generated by mitochondria, and/or the expression levels of K+ channels are likely to account for the postnatal maturation of O2 sensing by glomus cells. PMID:22801091

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

    PubMed

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

    2010-04-01

    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.

  8. The effect of discrete stimulation of carotid body chemoreceptors on atrial natriuretic peptide in anaesthetized dogs.

    PubMed Central

    al-Obaidi, M; Whitaker, E M; Karim, F

    1991-01-01

    1. In seven chloralose-anaesthetized and artificially ventilated beagles, the carotid sinus regions were vascularly isolated and perfused with either arterial or mixed (arterial and venous) blood (PO2 46.4 +/- 1.5 mmHg, mean +/- S.E.M.) to stimulate the chemoreceptors at constant flow and pressure. Cervical vagosympathetic trunks were ligated in all dogs, and gallamine triethiodide (2.0 mg kg-1 h-1, I.V.) was given in five dogs. Right atrial pressure was measured in all dogs, and left atrial pressure in four dogs. Mean aortic pressure was held constant (91.0 +/- 3.0 mmHg) by means of a reservoir connected to the animal via the common carotid and femoral arteries. Plasma atrial natriuretic peptide (ANP) was measured by radioimmunoassay and urinary sodium by flame photometry. 2. In seven dogs with mean carotid sinus pressure maintained at 96.0 +/- 4.3 mmHg, stimulation of the carotid chemoreceptors for 25 min produced significant increases in left atrial pressure of 41.2 +/- 3.3% (n = 4; P less than 0.005) from 5.4 +/- 0.6 cmH2O and of 30.9 +/- 4.5% (n = 7; P less than 0.002) in ANP from 31.6 +/- 2.1 pg ml-1. However, chemoreceptor stimulation produced significant decreases in urine flow rate of 26.1 +/- 1.9% (n = 9; P less than 0.001) from 0.29 +/- 0.03 ml min-1 (100 g kidney weight)-1 and sodium excretion of 29.0 +/- 2.3% (P less than 0.001) from 8.5 +/- 1.7 mumol min-1 (100 g kidney weight)-1 but right atrial pressure and heart rate did not change significantly. In three of the dogs, beta-adrenoceptor blockade by atenolol (2 mg kg-1, I.V.) greatly reduced the effects of chemoreceptor stimulation on plasma levels of ANP. 3. The results show, for the first time, that discrete stimulation of the carotid chemoreceptors caused an increase in plasma ANP levels, probably due to the reflex increase in atrial pressure that results from an inhibition of the cardiac sympathetic nerves, and an increase in venous return from a reduction of peripheral vascular capacitance. PMID

  9. A Short-Term Fasting in Neonates Induces Breathing Instability and Epigenetic Modification in the Carotid Body.

    PubMed

    Shirahata, Machiko; Tang, Wan-Yee; Kostuk, Eric W

    2015-01-01

    The respiratory control system is not fully developed in newborn, and data suggest that adequate nutrition is important for the development of the respiratory control system. Infants need to be fed every 2-4 h to maintain appropriate energy levels, but a skip of feeding can occur due to social economical reasons or mild sickness of infants. Here, we asked questions if a short-term fasting (1) alters carotid body (CB) chemoreceptor activity and integrated function of the respiratory control system; (2) causes epigenetic modification within the respiratory control system. Mouse pups (carotid sinus nerve activity appeared to be depressed after fasting. Moreover, fasting increased global 5mC and 5-hmC content in DNA isolated from the CB but not DNA in the superior cervical ganglion (SCG). Methylation specific PCR (MSPCR) revealed that fasting increased methylation of leptin and socs3 genes. The results suggest fasting inhibits CB activity leading to hypoventilation, and low glucose does not compensate the low CB activity. Epigenetic effect on CB function/activity may be related to the prolonged effect of fasting on ventilation.

  10. Carotid labyrinth of amphibians.

    PubMed

    Kusakabe, Tatsumi

    2002-11-01

    - and baroreceptor functions analogous to those of the mammalian carotid body and carotid sinus. The ultrastructural characteristics of the glomus cells during and after metamorphosis suggest that the glomus cells contribute to the chemoreception after metamorphosis. The three-dimensional fine structure of vascular corrosion casts suggests that the amphibian carotid labyrinth has the appropriate architecture for controlling vascular tone and the findings throughout metamorphosis reveal that the vascular regulatory function begins at an early stage of metamorphosis. In addition, immunohistochemical studies suggest that the vascular regulation in the carotid labyrinth is under peptidergic innervation. Thus, the multiple functions of the carotid labyrinth underline the importance of this relatively small organ for maintenance of homeostasis and appropriate blood supply to the cephalic region.

  11. Carotid Ultrasound

    MedlinePlus

    ... this page from the NHLBI on Twitter. Carotid Ultrasound Also known as carotid duplex. Carotid ultrasound is a painless imaging test that uses high- ... of your carotid arteries. This test uses an ultrasound machine, which includes a computer, a screen, and ...

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

    PubMed Central

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

    2015-01-01

    Abstract 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  ≈ 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 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 ()(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 (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. Key points The influence of specific carotid body (CB) normoxic hypocapnia, hypercapnia and normocapnia on the ventilatory sensitivity of central chemoreceptors to systemic hypercapnia was assessed in seven awake dogs with extracorporeal perfusion of the

  13. In the carotid body, galanin is a signal for neurogenesis in young, and for neurodegeneration in the old and in drug-addicted subjects.

    PubMed

    Mazzatenta, Andrea; Marconi, Guya D; Zara, Susi; Cataldi, Amelia; Porzionato, Andrea; Di Giulio, Camillo

    2014-01-01

    The carotid body is a highly specialized chemoreceptive structure for the detection of and reaction to hypoxia, through induction of an increase in hypoxia inducible factor. As tissue hypoxia increases with aging and can have dramatic effects in respiratory depression induced by drug addiction, we investigated the carotid body in young and old healthy subjects in comparison with drug-addicted subjects, including the expression of the neurotransmitter galanin. Galanin expression was recently reported for neuronal-like cells of the human carotid body, and it is implicated in several functions in neurons. In particular, this includes the regulation of differentiation of neural stem cells, and participation in the development and plasticity of the nervous system. Using immunohistochemistry detection, we demonstrate that galanin expression in the human carotid body in healthy older subjects and drug-addicted subjects is significantly reduced in comparison with healthy young subjects. This demonstrates not only the effects of normal aging and senescence, but also in the drug-addicted subjects, this appears to be due to a disorganization of the chemo-sensory region. With both aging and drug addiction, this results in a physiological reduction in neuronal-like cells, coupled with interlobular and intralobular increases in connective tissue fibers. Consequently, in both aging and drug addiction, this reduction of neuronal-like cells and the regeneration suggest that the carotid body is losing its sensory capabilities, with the transmission of chemoreceptive signals dramatically and vitally reduced. The level of galanin expression would thus provide a signal for neurogenesis in young subjects, and for neurodegeneration in older and drug-addicted subjects.

  14. Measurement of body composition in cats using computed tomography and dual energy X-ray absorptiometry.

    PubMed

    Buelund, Lene E; Nielsen, Dorte H; McEvoy, Fintan J; Svalastoga, Eiliv L; Bjornvad, Charlotte R

    2011-01-01

    Dual energy X-ray absorptiometry (DEXA) is a reference method for assessing body composition but is seldom `accessible in veterinary settings. Computed tomography (CT) can provide similar body composition estimates and we propose that it can be used in body composition studies in animals. We compared CT and DEXA data from 73 healthy adult neutered domestic cats. Three approaches for measuring adipose tissue percentage from full-body CT scans were explored. By examining the frequency distribution of voxels by Hounsfield unit (HU) value, it is possible to calculate a fat index (Fat%) that is in close agreement with the fat percentages obtained from DEXA scans. Fat% values obtained by the best of the methods had a mean difference of 0.96% (95% confidence interval 0.33-1.59%) from the DEXA results. Fat% obtained by the other two methods were characterized by good correlation but poor agreement and in one of the methods, the difference between the values from the two modalities was proportional to their mean. By using CT, it is possible to obtain body composition estimates that are in close agreement with those available using DEXA. While the significance of individual Fat% measurements obtained from CT can be difficult to interpret and to compare between centers, CT can contribute to research studies concerned either with nutrition or with obesity-related disorders.

  15. Distribution of voltage-gated potassium (Kv) and hyperpolarization-activated (HCN) channels in sensory afferent fibers in the rat carotid body

    PubMed Central

    Buniel, Maria; Glazebrook, Patricia A.; Ramirez-Navarro, Angelina; Kunze, Diana L.

    2008-01-01

    The chemosensory glomus cells of the carotid body (CB) detect changes in O2-tension. Carotid sinus nerve fibers, which originate from peripheral sensory neurons located within the petrosal ganglion, innervate the CB. Release of transmitter from glomus cells activates the sensory afferent fibers to transmit information to the nucleus of the solitary tract in the brainstem. The ion channels expressed within the sensory nerve terminals play an essential role in the ability of the terminal to initiate action potentials in response to transmitter-evoked depolarization. However, with a few exceptions, the identity of ion channels expressed in these peripheral nerve fibers is unknown. This study addresses the expression of voltage-gated channels in the sensory fibers with a focus on channels that set the resting membrane potential and regulate discharge patterns. Using immunohistochemistry and fluorescence confocal microscopy, potassium channel subunits and HCN (hyperpolarization-activated) family members were localized both in petrosal neurons that expressed tyrosine hydroxylase, and the CSN axons within the carotid body. Channels contributing to resting membrane potential including HCN2, responsible in part for Ih current, and the KCNQ2 and KCNQ5 subunits thought to underlie the neuronal “M current” were identified in the sensory neurons and their axons innervating the carotid body. In addition, the results presented here demonstrate expression of several potassium channels that shape the action potential and the frequency of discharge including Kv1.4, Kv1.5, Kv4.3, KCa (BK). The role of these channels should be considered in interpretation of the fiber discharge in response to perturbation of the carotid body environment. PMID:18668683

  16. Morphological differences of the carotid body among C57/BL6 (B6), A/J, and CSS B6A1 mouse strains.

    PubMed

    Chai, Sam; Gillombardo, Carl B; Donovan, Lucas; Strohl, Kingman P

    2011-08-15

    The C57/BL6 (B6) mouse strain exhibits post-hypoxic frequency decline and periodic breathing, as well as greater amount of irregular breathing during rest in comparison to the A/J and to the B6a1, a chromosomal substitution strain whereby the A/J chromosome 1 is bred onto the B6 background (Han et al., 2002; Yamauchi et al., 2008a,b). The hypothesis was that morphological differences in the carotid body would associate with such trait variations. After confirming strain differences in post-hypoxic ventilatory behavior, histological examination (n=8 in each group) using hematoxylin and eosin (H&E) staining revealed equivalent, well-defined tissue structure at the bifurcation of the carotid arteries, an active secretory parenchyma (type I cells) from the supportive stromal tissue, and clustering of type I cells in all three strains. Tyrosine hydroxylase (TH) immunohistochemical staining revealed a typical organization of type I cells and neurovascular components into glomeruli in all three strains. Image analysis from 5 μm sections from each strain generated a series of cytological metrics. The percent carotid body composition of TH+ type I cells in the A/J, B6 and B6a1 was 20±4%, 39±3%, and 44±3%, respectively (p=0.00004). However, cellular organization in terms of density and ultrastructure in the B6a1 is more similar to the B6 than to the A/J. These findings indicate that genetic mechanisms that produce strain differences in ventilatory function do not associate with carotid body structure or tyrosine hydroxylase morphology, and that A/J chromosome 1 does not contribute much to B6 carotid body morphology.

  17. Differential modulation by extracellular ATP of carotid chemosensory responses.

    PubMed

    Spergel, D; Lahiri, S

    1993-06-01

    The possibility that the carotid body has ATP surface receptors that mediate O2 chemoreception was tested. To distinguish between the event(s) initiating chemoreception and those at the neurotransmitter level, we also tested the chemosensory response to nicotine before and after ATP administration. Carotid bodies from cats anesthetized with pentobarbital sodium were perfused and superfused in vitro with modified Tyrode solution (PCO2 < 1 Torr, pH 7.4, 36 degrees C) equilibrated at PO2 > 400 or approximately 150 Torr while chemosensory discharge was recorded extracellularly. ATP and adenosine 5'-[gamma-thio]triphosphate stimulated discharge with similar dose dependence, whereas adenosine had little effect. ATP infusion for > or = 2 min evoked an initial stimulation of discharge followed by a decline to baseline (desensitization). Desensitization did not affect the response to hypoxia (perfusate flow interruption) but inhibited the response to nicotine (4-nmol pulse). Therefore, 1) the carotid body has surface ATP receptors that may mediate the chemosensory response to nicotine but not to hypoxia and 2) nicotinic receptors are not required for carotid body O2 chemoreception.

  18. Subcutaneous hemangiosarcoma induced by a foreign body (steel staple) in a cat.

    PubMed

    Tan, Rommel Max; Singh, Kuldeep; Sandman, Kristi

    2013-04-01

    An 8-year-old, female domestic shorthair cat was presented with a ventral abdominal subcutaneous mass. A radiograph showed that the center of the mass contained what appeared to be steel sutures, presumed to be from an ovariohysterectomy performed 7 years earlier. The excised mass was irregular and contained numerous pockets filled with friable necrotic material and hemorrhages that were dissected by fibrous connective tissue bands. Multiple tangled and fragmented pieces of steel staples were deeply embedded within the mass. Histologically, the mass was non-encapsulated, densely cellular, and infiltrative. Neoplastic cells lined caverns and channels and were factor VIII-positive by immunohistochemistry. The neoplastic cells were oval to round with granular cytoplasm and vesicular nucleus and exhibited moderate cellular and nuclear pleomorphism. A diagnosis of subcutaneous hemangiosarcoma was made. To our knowledge, this is the first report of foreign body associated hemangiosarcoma and the first case of steel staple associated neoplasm in domestic animals.

  19. Biphasic changes in body temperature produced by intracerebroventricular injections of histamine in the cat.

    PubMed

    Clark, W G; Cumby, H R

    1976-09-01

    1. Intracerebroventricular administration of histamine to cats caused hypothermia followed by a rise in body temperature. 2-Methylhistamine caused a similar biphasic response, while 3-methylhistamine had no effect on body temperature and 4-methylhistamine produced a delayed hyperthermia. Some tolerance to the hypothermic activity developed when a series of closely spaced injections of histamine was given. 2. Doses of histamine and 2-methylhistamine which altered body temperature when given centrally were ineffective when infused or injected I.V. 3. Pyrilamine, an H1-receptor antagonist, prevented the hypothermic response to histamine. 4. Hypothermic responses to histamine at an environmental temperature of 22 degrees C were comparable to responses in a cold room at 4 degrees C in both resting animals and animals acting to depress a lever to escape an external heat load. A change in error signal from the thermostat could account for these results. However, lesser degrees of hypothermia developed when histamine was given to animals in a hot environment. In some, but not all animals, this smaller response could be attributed to inadequate heat loss in spite of maximal activation of heat-loss mechanisms. 5. The hyperthermic response to histamine was antagonized by central, but not peripheral, injection of metiamide, an H2-receptor antagonist. 6. The results indicate that histamine and related agents can act centrally to cause both hypothermia, mediated by H1-receptors, and hyperthermia, mediated by H2-receptors.

  20. Serotonin-mediated modulation of hypoxia-induced intracellular calcium responses in glomus cells isolated from rat carotid body.

    PubMed

    Yokoyama, Takuya; Nakamuta, Nobuaki; Kusakabe, Tatsumi; Yamamoto, Yoshio

    2015-06-15

    In the present study, we examined serotonin (5-HT)-induced intracellular Ca(2+) ([Ca(2+)]i) responses to hypoxia in glomus cells isolated from carotid body (CB) of the rat. 5-HT did not induce any [Ca(2+)]i responses in clustered glomus cells during normoxia (21% O2), whereas, the perfusion of hypoxic solution (1% O2) induced repetitive increases in [Ca(2+)]i in the same specimens. The frequency and magnitude of hypoxia-induced [Ca(2+)]i changes observed in the glomus cells were enhanced in the presence of 5-HT, and this response was inhibited by the 5-HT2 receptor antagonist, ketanserin. Furthermore, RT-PCR analysis detected the expression of 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1F, 5-HT2A, 5-HT2B, 5-HT3A, and 5-HT3B receptor mRNAs in extracts of the CB. These results suggest that 5-HT increases hypoxia-induced [Ca(2+)]i responses in glomus cells. 5-HT may elevate hypoxic responses in glomus cells in order to increase chemosensory activity of the CB.

  1. Neural coding of repetitive clicks in the medial geniculate body of cat.

    PubMed

    Rouiller, E; de Ribaupierre, Y; Toros-Morel, A; de Ribaupierre, F

    1981-09-01

    The activity of 418 medial geniculate body (MGB) units was studied in response to repetitive acoustic pulses in 35 nitrous oxide anaesthetized cats. The proportion of MGB neurons insensitive to repetitive clicks was close to 30%. On the basis of their pattern of discharge, the responsive units were divided into three categories. The majority of them (71%), classified as "lockers', showed discharges precisely time-locked to the individual clicks of the train. A few units (8%), called "groupers', had discharges loosely synchronized to low-rate repetitive clicks. When the spikes were not synchronized, the cell had transient or sustained responses for a limited frequency range and was classified as a "special responder' (21%). Responses of "lockers' were time-locked up to a limiting rate, which varied between 10 and 800 Hz; half of the "lockers' had a limiting rate of locking equal to or higher than 100 Hz. The degree of entrainment, defined as the probability that each click evokes at least one spike, regularly decreases for increasing rates; on the other hand, the precision of locking increasing increases with frequency. The time jitter observed at 100 Hz might be as small as 0.2 ms and was 1.2 ms on average. The population of "lockers' can mark with precision the transients of complex sounds and has response properties still compatible with a temporal coding of the fundamental frequency of most animal vocalizations.

  2. Whole-Body Counter Evaluation of Internal Radioactive Cesium in Dogs and Cats Exposed to the Fukushima Nuclear Disaster

    PubMed Central

    Wada, Seiichi; Ito, Nobuhiko; Watanabe, Masamichi; Kakizaki, Takehiko; Natsuhori, Masahiro; Kawamata, Jun; Urayama, Yoshio

    2017-01-01

    As a result of the 2011 nuclear incident that occurred at the Fukushima Nuclear Power Plant, a large number of abandoned dogs and cats were left within the disaster zone. A small number of these animals were rescued and cared for at shelters. Prior to the dispersal of these animals to their owners or fosterers, we evaluated the degree of internal radiocesium contamination using a specially designed whole-body counter. We conducted 863 non-invasive measurements of gamma rays due to internal radioactive cesium for 68 dogs and 120 cats at one shelter. After plotting graphs of 137Cs density we generated exponential functions of decay from seven dogs and six cats. From the regression formulae, we were able to determine the biological half-lives as 38.2 days for dogs and 30.8 days for cats. We found that in dogs there was a correlation between the biological half-life of radioactive cesium and age. Using our data, we estimated whole-body densities for each cat and dog at the time when they were rescued. We found that there were deviations in the data distributions among the different species, likely due to the timing of rescue, or living habits prior to rescue. A significant correlation was found when extracted feline reproductive organs were analyzed; the coefficients for the estimation of whole-body densities were approximately 7-fold higher than those based on the extracted feline reproductive organs. This may be due to the fact that majority of the radioactive cesium accumulates within muscular tissue with less distribution in other organs. It is possible to plan the appropriate management period in an animal shelter based on the use of the biological half-life of radioactive cesium calculated in this study. We believe that the correlations we uncovered in this work would be of great use for the management of companion animals in the event of a future nuclear accident. PMID:28099476

  3. Whole-Body Counter Evaluation of Internal Radioactive Cesium in Dogs and Cats Exposed to the Fukushima Nuclear Disaster.

    PubMed

    Wada, Seiichi; Ito, Nobuhiko; Watanabe, Masamichi; Kakizaki, Takehiko; Natsuhori, Masahiro; Kawamata, Jun; Urayama, Yoshio

    2017-01-01

    As a result of the 2011 nuclear incident that occurred at the Fukushima Nuclear Power Plant, a large number of abandoned dogs and cats were left within the disaster zone. A small number of these animals were rescued and cared for at shelters. Prior to the dispersal of these animals to their owners or fosterers, we evaluated the degree of internal radiocesium contamination using a specially designed whole-body counter. We conducted 863 non-invasive measurements of gamma rays due to internal radioactive cesium for 68 dogs and 120 cats at one shelter. After plotting graphs of 137Cs density we generated exponential functions of decay from seven dogs and six cats. From the regression formulae, we were able to determine the biological half-lives as 38.2 days for dogs and 30.8 days for cats. We found that in dogs there was a correlation between the biological half-life of radioactive cesium and age. Using our data, we estimated whole-body densities for each cat and dog at the time when they were rescued. We found that there were deviations in the data distributions among the different species, likely due to the timing of rescue, or living habits prior to rescue. A significant correlation was found when extracted feline reproductive organs were analyzed; the coefficients for the estimation of whole-body densities were approximately 7-fold higher than those based on the extracted feline reproductive organs. This may be due to the fact that majority of the radioactive cesium accumulates within muscular tissue with less distribution in other organs. It is possible to plan the appropriate management period in an animal shelter based on the use of the biological half-life of radioactive cesium calculated in this study. We believe that the correlations we uncovered in this work would be of great use for the management of companion animals in the event of a future nuclear accident.

  4. 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.

  5. Attenuated outward potassium currents in carotid body glomus cells of heart failure rabbit: involvement of nitric oxide

    PubMed Central

    Li, Yu-Long; Sun, Shu-Yu; Overholt, Jeffery L; Prabhakar, Nanduri R; Rozanski, George J; Zucker, Irving H; Schultz, Harold D

    2004-01-01

    It has been shown that peripheral chemoreceptor sensitivity is enhanced in both clinical and experimental heart failure (HF) and that impairment of nitric oxide (NO) production contributes to this enhancement. In order to understand the cellular mechanisms associated with the alterations of chemoreceptor function and the actions of NO in the carotid body (CB), we compared the outward K+ currents (IK) of glomus cells in sham rabbits with that in HF rabbits and monitored the effects of NO on these currents. Ik was measured in glomus cells using conventional and perforated whole-cell configurations. IK was attenuated in glomus cells of HF rabbits, and their resting membrane potentials (−34.7 ± 1.0 mV) were depolarized as compared with those in sham rabbits (−47.2 ± 1.9 mV). The selective Ca2+-dependent K+ channel (KCa) blocker iberiotoxin (IbTx, 100 nm) reduced IK in glomus cells from sham rabbits, but had no effect on IK from HF rabbits. In perforated whole-cell mode, the NO donor SNAP (100 μm) increased IK in glomus cells from HF rabbits to a greater extent than that in sham rabbits (P < 0.01), and IbTx inhibited the effects of SNAP. However, in conventional whole-cell mode, SNAP had no effect. Nω-nitro-L-arginine (L-NNA, NO synthase inhibitor) decreased Ik in sham rabbits but not in HF rabbits. The guanylate cyclase inhibitor 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ) inhibited the effect of SNAP on Ik. These results demonstrate that IK is reduced in CB glomus cells from HF rabbits. This effect is due mainly to the suppression of KCa channel activity caused by decreased availability of NO. In addition, intracellular cGMP is necessary for the KCa channel modulation by NO. PMID:14673183

  6. Hypoxia induces voltage-dependent Ca2+ entry and quantal dopamine secretion in carotid body glomus cells.

    PubMed Central

    Ureña, J; Fernández-Chacón, R; Benot, A R; Alvarez de Toledo, G A; López-Barneo, J

    1994-01-01

    We have investigated the changes of cytosolic [Ca2+] and the secretory activity in single glomus cells dispersed from rabbit carotid bodies during exposure to solutions with variable O2 tension (Po2). In normoxic conditions (Po2 = 145 mmHg; 1 mmHg = 133 Pa), intracellular [Ca2+] was 58 +/- 29 nM, and switching to low Po2 (between 10 and 60 mmHg) led to a reversible increase of [Ca2+] up to 800 nM. The response to hypoxia completely disappeared after removal of external Ca2+ or with the addition of 0.2 mM Cd2+ to the external solution. These same solutions also abolished both the Ca2+ current of the cells and the increase of internal [Ca2+] elicited by high external K+. Elevations of cytosolic [Ca2+] in response to hypoxia or to direct membrane depolarization elicited the release of dopamine, which was detected by amperometric techniques. Dopamine secretion occurred in episodes of spike-like activity that appear to represent the release from single secretory vesicles. From the mean charge of well-resolved secretory events, we estimated the average number of dopamine molecules per vesicle to be approximately 140,000, a value about 15 times smaller than a previous estimate in chromaffin granules of adrenomedullary cells. These results directly demonstrate in a single-cell preparation the secretory response of glomus cells to hypoxia. The data indicate that the enhancement of cellular excitability upon exposure to low Po2 results in Ca2+ entry through voltage-gated channels, which leads to an increase in intracellular [Ca2+] and exocytotic transmitter release. PMID:7937863

  7. Postsynaptic action of GABA in modulating sensory transmission in co-cultures of rat carotid body via GABAA receptors

    PubMed Central

    Zhang, Min; Clarke, Katherine; Zhong, Huijun; Vollmer, Cathy; Nurse, Colin A

    2009-01-01

    GABA is expressed in carotid body (CB) chemoreceptor type I cells and has previously been reported to modulate sensory transmission via presynaptic GABAB receptors. Because low doses of clinically important GABAA receptor (GABAAR) agonists, e.g. benzodiazepines, have been reported to depress afferent CB responses to hypoxia, we investigated the potential contribution of GABAAR in co-cultures of rat type I cells and sensory petrosal neurones (PNs). During gramicidin perforated-patch recordings (to preserve intracellular Cl−), GABA and/or the GABAA agonist muscimol (50 μm) induced a bicuculline-sensitive membrane depolarization in isolated PNs. GABA-induced whole-cell currents reversed at ∼−38 mV and had an EC50 of ∼10 μm (Hill coefficient =∼1) at −60 mV. During simultaneous PN and type I cell recordings at functional chemosensory units in co-culture, bicuculline reversibly potentiated the PN, but not type I cell, depolarizing response to hypoxia. Application of the CB excitatory neurotransmitter ATP (1 μm) over the soma of functional PN induced a spike discharge that was markedly suppressed during co-application with GABA (2 μm), even though GABA alone was excitatory. RT-PCR analysis detected expression of GABAergic markers including mRNA for α1, α2, β2, γ2S, γ2L and γ3 GABAAR subunits in petrosal ganglia extracts. Also, CB extracts contained mRNAs for GABA biosynthetic markers, i.e. glutamate decarboxylase (GAD) isoforms GAD 67A,E, and GABA transporter isoforms GAT 2,3 and BGT-1. In CB sections, sensory nerve endings apposed to type I cells were immunopositive for the GABAAR β subunit. These data suggest that GABA, released from the CB during hypoxia, inhibits sensory discharge postsynaptically via a shunting mechanism involving GABAA receptors. PMID:19029183

  8. 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.

  9. Haloperidol-induced suppression of carotid chemoreception in vitro.

    PubMed

    Nolan, W F; Donnelly, D F; Smith, E J; Dutton, R E

    1985-09-01

    Effects of antagonism of endogenous dopamine with haloperidol on single-unit frequency, interspike interval distribution, and interval serial dependency of the cat sinus nerve were tested using an in vitro carotid body-sinus nerve superfusion technique. A dose dependency of inhibition by haloperidol (0.05-2.0 microgram/ml) was observed. Superfusion with 1-2 microgram/ml haloperidol significantly reduced frequency within 5 min (P less than 0.05) and caused a complete cessation of firing within 25 min in 5 of 10 chemoreceptor units. Frequency recovered to control during drug washout. Acetylcholine (10-micrograms/ml superfusion or 500-micrograms bolus) increased sinus nerve activity under control conditions but not during superfusion with haloperidol. No effect of haloperidol on impulse serial dependency was detected. However, interval distribution was significantly altered by haloperidol in five of six chemoreceptor units. Our results suggest an excitatory role for dopamine in carotid chemoreception.

  10. An Unusual Case of a Nasal Foreign Body in a Cat with Chronic Nasal Discharge.

    PubMed

    Bellei, Emma; Pisoni, Luciano; Joechler, Monika; Pietra, Marco

    2015-01-01

    This report describes a cat infected with the feline infectious virus and a 1 yr history of unilateral mucopurulent nasal discharge. Intraoral radiography and endoscopic examination revealed the presence of a large fragment of tooth root in the right nasal cavity. The cat had previously undergone maxillary canine tooth (104) extraction. The root was successfully removed by an endoscopic-assisted procedure, and follow-up examination 1 yr later documented complete disappearance of the respiratory signs.

  11. A revisit to O2 sensing and transduction in the carotid body chemoreceptors in the context of reactive oxygen species biology.

    PubMed

    Gonzalez, C; Agapito, M T; Rocher, A; Gomez-Niño, A; Rigual, R; Castañeda, J; Conde, S V; Obeso, A

    2010-12-31

    Oxygen-sensing and transduction in purposeful responses in cells and organisms is of great physiological and medical interest. All animals, including humans, encounter in their lifespan many situations in which oxygen availability might be insufficient, whether acutely or chronically, physiologically or pathologically. Therefore to trace at the molecular level the sequence of events or steps connecting the oxygen deficit with the cell responses is of interest in itself as an achievement of science. In addition, it is also of great medical interest as such knowledge might facilitate the therapeutical approach to patients and to design strategies to minimize hypoxic damage. In our article we define the concepts of sensors and transducers, the steps of the hypoxic transduction cascade in the carotid body chemoreceptor cells and also discuss current models of oxygen- sensing (bioenergetic, biosynthetic and conformational) with their supportive and unsupportive data from updated literature. We envision oxygen-sensing in carotid body chemoreceptor cells as a process initiated at the level of plasma membrane and performed by a hemoprotein, which might be NOX4 or a hemoprotein not yet chemically identified. Upon oxygen-desaturation, the sensor would experience conformational changes allosterically transmitted to oxygen regulated K+ channels, the initial effectors in the transduction cascade. A decrease in their opening probability would produce cell depolarization, activation of voltage dependent calcium channels and release of neurotransmitters. Neurotransmitters would activate the nerve endings of the carotid body sensory nerve to convey the information of the hypoxic situation to the central nervous system that would command ventilation to fight hypoxia.

  12. 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.

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

    PubMed Central

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

    2015-01-01

    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 ([Ca2+]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 [Ca2+]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 [Ca2+]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 Ca2+ 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 [Ca2+]i response to hypoxia. CIH had no effect on CaV3.2 mRNA levels. CIH augmented Ca2+ 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 Ca2+ influx via ROS-dependent facilitation of CaV3.2 protein trafficking to the plasma membrane. PMID:26561606

  14. Relative mitochondrial membrane potential and [Ca2+]i in type I cells isolated from the rabbit carotid body.

    PubMed Central

    Duchen, M R; Biscoe, T J

    1992-01-01

    1. In the accompanying paper (Duchen & Biscoe, 1992) we have described graded changes in autofluorescence derived from mitochondrial NAD(P)H in type I cells of the carotid body in response to changes of PO2 over a physiologically significant range. These observations suggest that mitochondrial function in these cells is unusually sensitive to oxygen and could play a role in oxygen sensing. We have now explored further the relationships between hypoxia, mitochondrial membrane potential (delta psi m) and [Ca2+]i. 2. The fluorescence of Rhodamine 123 (Rh 123) accumulated within mitochondria is quenched by delta psi m. Mitochondrial depolarization thus increases the fluorescence signal. Blockade of electron transport (CN-, anoxia, rotenone) and uncoupling agents (e.g. carbonyl cyanide p-trifluoromethoxy-phenylhydrazone; FCCP) increased fluorescence by up to 80-120%, while fluorescence was reduced by blockade of the F0 proton channel of the mitochondrial ATP synthase complex (oligomycin). 3. delta psi m depolarized rapidly with anoxia, and was usually completely dissipated within 1-2 min. The depolarization of delta psi m with anoxia (or CN-) and repolarization on reoxygenation both followed a time course well characterized as the sum of two exponential processes. Oligomycin (0.2-2 micrograms/ml) hyperpolarized delta psi m and abolished the slower components of both the depolarization with anoxia and of the subsequent repolarization. These data (i) illustrate the role of the F1-F0 ATP synthetase in slowing the rate of dissipation of delta psi m on cessation of electron transport, (ii) confirm blockade of the ATP synthetase by oligomycin at these concentrations, and (iii) indicate significant accumulation of intramitochondrial ADP during 1-2 min of anoxia. 4. Depolarization of delta psi m was graded with graded changes in PO2 below about 60 mmHg. The stimulus-response curves thus constructed strongly resemble those for [Ca2+]i and NAD(P)H with PO2. The change in delta

  15. Neurons sensitive to narrow ranges of repetitive acoustic transients in the medial geniculate body of the cat.

    PubMed

    Rouiller, E; de Ribaupierre, F

    1982-01-01

    Neuronal activity was recorded in the medial geniculate body (MGB) of nitrous oxide anaesthetized, paralysed cats in response to click trains. For most cells responding to these stimuli the spike discharges are precisely time locked to individual clicks within the train. The present study has revealed that, apart from the normal "locker" response being characterized by a monotonic decrease in the entrainment as the frequency of the clicks within the train increases, there is a small population of "lockers" which show a non-monotonic response to increasing click frequency. 41% of these non-monotonic cells were not at all entrained by the lowest click rates and had time-locked responses for very restricted frequency ranges. These particular non-monotonic "lockers" were more commonly-found in the posterior part of the pars lateralis and in the suprageniculate nucleus. These cells might be involved in the temporal coding of natural sounds such as animal vocalizations and the cat's purr.

  16. The role of sodium and calcium ions in the hypothalamus in the control of body temperature of the unanaesthetized cat

    PubMed Central

    Myers, R. D.; Veale, W. L.

    1971-01-01

    1. Isolated regions of the anterior, posterior and other areas of the hypothalamus of the unanaesthetized cat were perfused by means of push-pull cannulae lowered through permanently implanted guide tubes. Each site was perfused for a 30 min interval at a rate of 50 μl./min. Concentrations of sodium, calcium, potassium and magnesium ions in the perfusate were altered selectively. 2. Sodium ions in a concentration which varied from 13·6 to 68·0 mM in excess of the level in extracellular fluid caused a steep rise in the temperature of the cat when the solution was perfused at sites located within the posterior hypothalamic area. Shivering, vasoconstriction, and piloerection accompanied the increase in temperature. When the chloride was replaced in the perfusate by the toluene-p-sulphonate salt of sodium, the hyperthermia was equally intense. Solutions containing excess sodium ions perfused within the anterior and other hypothalamic areas produced either a slight fall or rise in temperature as well as other physiological changes. 3. Calcium ions in a concentration which varied from 2·6 to 10·4 mM in excess of the physiological level perfused at the same sites within the posterior region of the hypothalamus produced a sharp fall in body temperature, which was accompanied by vasodilatation and a decrease in the activity of the cat. When solutions containing excess calcium were perfused in the anterior and other hypothalamic areas, no consistent change in temperature occurred. 4. Potassium or magnesium ions in concentrations which varied from two to ten times the level in extracellular fluid had virtually no effect on the temperature of the cat when they were perfused in the anterior, posterior or other areas of the hypothalamus. 5. We conclude that the constancy in the ratio between sodium and calcium ions in the posterior hypothalamus may be the inherent mechanism by which the set-point for body temperature is determined. ImagesFig. 7 PMID:5548019

  17. Age and body weight effects on glucose and insulin tolerance in colony cats maintained since weaning on high dietary carbohydrate.

    PubMed

    Backus, R C; Cave, N J; Ganjam, V K; Turner, J B M; Biourge, V C

    2010-12-01

    High dietary carbohydrate is suggested to promote development of diabetes mellitus in cats. Glucose tolerance, insulin sensitivity, and insulin secretion were assessed in young [0.8-2.3 (median = 1.1) years, n = 13] and mature [4.0-7.0 (median 5.8) years, n = 12] sexually intact females of a large (n ≅ 700) feline colony in which only dry-type diets (35% metabolizable energy as carbohydrate) were fed from weaning. Insulin sensitivity was assessed from the 'late-phase' (60-120 min) plasma insulin response of intravenous glucose tolerance tests (IVGTTs) and from fractional change in glycaemia from baseline 15 min after an insulin bolus (0.1 U/kg, i.v.). Insulin secretion was assessed from the 'early-phase' (0-15 min) plasma insulin response of IVGTTs. Compared to the young cats, the mature cats had greater body weights [2.3-3.8 (median = 2.9) vs. 3.0-6.3 (median = 4.0) kg, p < 0.01], greater late-phase insulin responses (p < 0.05), lower insulin-induced glycaemic changes (p = 0.06), lower early-phase insulin responses (p < 0.05), and non-significantly different rates of glucose disposal. The late-phase insulin response was correlated with body weight and age (p < 0.05). When group assignments were balanced for body weight, the age-group differences and correlations became non-significant. The findings indicate that body weight gain is more likely than dry-type diets to induce the pre-diabetic conditions of insulin resistance and secretion dysfunction.

  18. Carotid Endarterectomy

    MedlinePlus

    ... is not a cure. Your arteries can become blocked again if your underlying condition, such as high ... or cut, on your neck to expose the blocked section of the carotid artery. Your surgeon will ...

  19. Carotid duplex

    MedlinePlus

    ... moved around your neck. The pressure should not cause any pain. You may also hear a "whooshing" sound. This is normal. ... clotting (thrombosis) Narrowing in the arteries (stenosis) Other ... an abnormal sound called a bruit over the carotid neck arteries. ...

  20. Effects of modulators of AMP-activated protein kinase on TASK-1/3 and intracellular Ca2+ concentration in rat carotid body glomus cells

    PubMed Central

    Kim, Donghee; Kang1,2, Dawon; Martin, Elizabeth A.; Kim, Insook; Carroll, John L.

    2014-01-01

    Acute hypoxia depolarizes carotid body chemoreceptor (glomus) cells and elevates intracellular Ca2+ concentration ([Ca2+]i). Recent studies suggest that AMP-activated protein kinase (AMPK) mediates these effects of hypoxia by inhibiting the background K+ channels such as TASK. Here we studied the effects of modulators of AMPK on TASK activity in cell-attached patches. Activators of AMPK (1 mM AICAR and 0.1–0.5 mM A769662) did not inhibit TASK activity or cause depolarization during acute (10 min) or prolonged (2–3 hr) exposure. Hypoxia inhibited TASK activity by ~70% in cells pretreated with AICAR or A769662. Both AICAR and A769662 (15–40 min) failed to increase [Ca2+]i in glomus cells. Compound C (40 µM), an inhibitor of AMPK, showed no effect on hypoxia-induced inhibition of TASK. AICAR and A769662 phosphorylated AMPKα in PC12 cells, and Compound C blocked the phosphorylation. Our results suggest that AMPK does not affect TASK activity and is not involved in hypoxia-induced elevation of intracellular [Ca2+] in isolated rat carotid body glomus cells. PMID:24530802

  1. 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.

  2. Intracellular pH and its regulation in isolated type I carotid body cells of the neonatal rat.

    PubMed Central

    Buckler, K J; Vaughan-Jones, R D; Peers, C; Nye, P C

    1991-01-01

    1. The dual-emission pH-sensitive fluoroprobe carboxy-SNARF-1 (carboxy-seminaptharhodofluor) was used to measure pHi in type I cells enzymically dispersed from the neonatal rat carotid body. 2. Steady-state pHi in cells bathed in a HEPES-buffered Tyrode solution (pH 7.4) was found to be remarkably alkaline (pHi = 7.77) whereas cells bathed in a CO2-HCO3(-)-buffered Tyrode solution (pH 7.4) had a more 'normal' pHi (pHi = 7.28). These observations were further substantiated by using an independent nullpoint test method to determine pHi. 3. Intracellular intrinsic buffering (beta, determined by acidifying the cell using an NH4Cl pre-pulse) was in the range 7-20 mM per pH unit and appeared to be dependent upon pHi with beta increasing as pHi decreased. 4. In cells bathed in a HEPES-buffered Tyrode solution, pHi recovery from an induced intracellular acid load (10 mM-NH4Cl pre-pulse) was inhibited by the Na(+)-H+ exchange inhibitor ethyl isopropyl amiloride (EIPA; 150 microM) or substitution of Nao+ with N-methyl-D-glucamine (NMG). Both EIPA and Nao+ removal also caused a rapid intracellular acidification, which in the case of Nao+ removal, was readily reversible. The rate of this acidification was similar for both Nao+ removal and EIPA addition. 5. Transferring cells from a HEPES-buffered Tyrode solution to one buffered with 5% CO2-HCO3- resulted in an intracellular acidification which was partially, or wholly, sustained. The rate of acidification upon transfer to CO2-HCO3- was considerably slowed by the membrane permeant carbonic anhydrase inhibitor, acetazolamide, thus indicating the presence of the enzyme in these cells. 6. In CO2-HCO3(-)-buffered Tyrode solution, pHi recovery from an intracellular acidosis (NH4+ pre-pulse) was only partially inhibited by EIPA or amiloride whereas Nao+ removal completely inhibited the recovery. The stilbene DIDS (4,4-diisothiocyanatostilbenedisulphonic acid, 200 microM) also partially inhibited pHi recovery following an induced

  3. Whole-body biodistribution of 3'-deoxy-3'-[(18) f]fluorothymidine ((18) FLT) in healthy adult cats.

    PubMed

    Rowe, Joshua A; Morandi, Federica; Wall, Jonathan S; Akula, Murthy; Kennel, Stephen J; Osborne, Dustin; Martin, Emily B; Galyon, Gina D; Long, Misty J; Stuckey, Alan C; LeBlanc, Amy K

    2013-01-01

    Positron emission tomography/computed tomography (PET/CT) utilizing 3'-deoxy-3'-[(18) F]fluorothymidine ((18) FLT), a proliferation tracer, has been found to be a useful tool for characterizing neoplastic diseases and bone marrow function in humans. As PET and PET/CT imaging become increasingly available in veterinary medicine, knowledge of radiopharmaceutical biodistribution in veterinary species is needed for lesion interpretation in the clinical setting. The purpose of this study was to describe the normal biodistribution of (18) FLT in adult domestic cats. Imaging of six healthy young adult castrated male cats was performed using a commercially available PET/CT scanner consisting of a 64-slice helical CT scanner with an integrated whole-body, high-resolution lutetium oxy-orthosilicate (LSO) PET scanner. Cats were sedated and injected intravenously with 108.60 ± 2.09 (mean ± SD) MBq of (18) FLT (greater than 99% radiochemical purity by high-performance liquid chromatography). Imaging was performed in sternal recumbency under general anesthesia. Static images utilizing multiple bed positions were acquired 80.83 ± 7.52 (mean ± SD) minutes post-injection. Regions of interest were manually drawn over major parenchymal organs and selected areas of bone marrow and increased tracer uptake. Standardized uptake values were calculated. Notable areas of uptake included hematopoietic bone marrow, intestinal tract, and the urinary and hepatobiliary systems. No appreciable uptake was observed within brain, lung, myocardium, spleen, or skeletal muscle. Findings from this study can be used as baseline data for future studies of diseases in cats.

  4. [Syncope and carotid paraganglioma].

    PubMed

    Bizueto-Rosas, Héctor; Salazar-Reyes, Anabel; Moran-Reyes, Ely Guadalupe; González-Arcos, Gregorio; Hernández-Pérez, Noemí A; Solorio-Rosette, Hugo F; Soto-Hernández, Gabriel

    2014-01-01

    Syncope is a medical emergency, which is more or less frequent. Its prevalence increases with age. It is defined as the loss of consciousness and postural tone resulting from a transient alteration of cerebral flow. It appears suddenly, but it does not leave behind any sequela or after-effects. Out of two groups, the neutrally mediated (or neuromediated) syncope, especially the one called carotid sinus hypersensitivity, is related to the carotid sinus paraganglioma. It is triggered by sinus pressure, which results in sudden death by overstimulation. In the next article, we show the case of a sexagenarian female patient with a disabling syncope and a 7 cm carotid body paraganglioma, which did not allow her the minimum movement of lateral dorsiflexion or extension of the neck. For this reason, the patient had to remain hospitalized, in a dorsal decubitus position with semiflexion of the neck. Before the surgery was practiced, a temporary pacemaker was used, and after the resection of the carotid body paraganglioma, in accordance to the patient's studies of cardiac electrophysiology, she was discharged without electrical nerve stimulation.

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

    PubMed

    Prabhakhar, Nanduri R; Joyner, Michael J

    2014-01-01

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

  7. Inhibition of adenylate cyclase attenuates muscarinic Ca²(+) signaling by a PKA-independent mechanism in rat carotid body Type I cells.

    PubMed

    Thompson, Carrie M; Wyatt, Christopher N

    2011-01-31

    Carotid body (CB) Type I cells respond to hypoxia by releasing excitatory and inhibitory neurotransmitters. This mechanism leads to increased firing of the carotid sinus nerve (CSN) which alters breathing to maintain blood gases within the physiological range. Acetylcholine targets both muscarinic and nicotinic receptors in the rat CB, acting postsynaptically on CSN and presynaptically on Type I cells. Muscarinic Ca²(+) signaling is inhibited by the activation of G(i)-coupled receptors including histamine H3 receptors. Here inhibition of adenylate cyclase with SQ22536 mimicked H3 receptor activation. Using Ca²(+) imaging techniques it was observed that inhibition of muscarinic Ca²(+) signaling was independent of protein kinase A (PKA) as PKA inhibitors H89 and KT5720 were without effect on the muscarinic Ca²(+) response. By contrast the Epac (exchange protein activated by cAMP) inhibitor brefeldin A inhibited muscarinic Ca²(+) signaling whereas the Epac activator 8-pCPT-2'-O-Me-cAMP-AM potentiated Ca²(+) signaling. Thus in Type I cells inhibition of adenylate cyclase inhibited muscarinic Ca²(+) signaling via a PKA-independent pathway that may rely upon modulation of Epac.

  8. Responses of neurons in the rostral ventrolateral medulla to whole body rotations: comparisons in decerebrate and conscious cats

    PubMed Central

    DeStefino, V. J.; Reighard, D. A.; Sugiyama, Y.; Suzuki, T.; Cotter, L. A.; Larson, M. G.; Gandhi, N. J.; Barman, S. M.

    2011-01-01

    The responses to vestibular stimulation of brain stem neurons that regulate sympathetic outflow and blood flow have been studied extensively in decerebrate preparations, but not in conscious animals. In the present study, we compared the responses of neurons in the rostral ventrolateral medulla (RVLM), a principal region of the brain stem involved in the regulation of blood pressure, to whole body rotations of conscious and decerebrate cats. In both preparations, RVLM neurons exhibited similar levels of spontaneous activity (median of ∼17 spikes/s). The firing of about half of the RVLM neurons recorded in decerebrate cats was modulated by rotations; these cells were activated by vertical tilts in a variety of directions, with response characteristics suggesting that their labyrinthine inputs originated in otolith organs. The activity of over one-third of RVLM neurons in decerebrate animals was altered by stimulation of baroreceptors; RVLM units with and without baroreceptor signals had similar responses to rotations. In contrast, only 6% of RVLM neurons studied in conscious cats exhibited cardiac-related activity, and the firing of just 1% of the cells was modulated by rotations. These data suggest that the brain stem circuitry mediating vestibulosympathetic reflexes is highly sensitive to changes in body position in space but that the responses to vestibular stimuli of neurons in the pathway are suppressed by higher brain centers in conscious animals. The findings also raise the possibility that autonomic responses to a variety of inputs, including those from the inner ear, could be gated according to behavioral context and attenuated when they are not necessary. PMID:21493724

  9. Responses of neurons in the rostral ventrolateral medulla to whole body rotations: comparisons in decerebrate and conscious cats.

    PubMed

    Destefino, V J; Reighard, D A; Sugiyama, Y; Suzuki, T; Cotter, L A; Larson, M G; Gandhi, N J; Barman, S M; Yates, B J

    2011-06-01

    The responses to vestibular stimulation of brain stem neurons that regulate sympathetic outflow and blood flow have been studied extensively in decerebrate preparations, but not in conscious animals. In the present study, we compared the responses of neurons in the rostral ventrolateral medulla (RVLM), a principal region of the brain stem involved in the regulation of blood pressure, to whole body rotations of conscious and decerebrate cats. In both preparations, RVLM neurons exhibited similar levels of spontaneous activity (median of ∼17 spikes/s). The firing of about half of the RVLM neurons recorded in decerebrate cats was modulated by rotations; these cells were activated by vertical tilts in a variety of directions, with response characteristics suggesting that their labyrinthine inputs originated in otolith organs. The activity of over one-third of RVLM neurons in decerebrate animals was altered by stimulation of baroreceptors; RVLM units with and without baroreceptor signals had similar responses to rotations. In contrast, only 6% of RVLM neurons studied in conscious cats exhibited cardiac-related activity, and the firing of just 1% of the cells was modulated by rotations. These data suggest that the brain stem circuitry mediating vestibulosympathetic reflexes is highly sensitive to changes in body position in space but that the responses to vestibular stimuli of neurons in the pathway are suppressed by higher brain centers in conscious animals. The findings also raise the possibility that autonomic responses to a variety of inputs, including those from the inner ear, could be gated according to behavioral context and attenuated when they are not necessary.

  10. 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.

  11. Body composition and amino acid concentrations of select birds and mammals consumed by cats in northern and central California.

    PubMed

    Kremen, N A; Calvert, C C; Larsen, J A; Baldwin, R A; Hahn, T P; Fascetti, A J

    2013-03-01

    The diet of the feral domestic cat consists of primarily birds and small mammals, but the nutritional composition is relatively unknown. Because of the increasing popularity of natural diets for cats and other wild captive carnivores, the purpose of this study was to describe the body composition and AA concentrations of select birds and small mammals in northern and central California: wild-caught mice (n = 7), Norway rats (n = 2), roof rats (n = 2), voles (n = 4), moles (n = 2), gophers (n = 3), and birds (n = 4). Body water, crude fat (CFa), CP, ash, and AA composition for each specimen were determined. Results are reported as mean ± SD. All results are reported on a DM basis except body water (as-is basis) and AA (g/16 g N). Combined, carcasses had this mean composition: 67.35 ± 3.19% water, 11.72 ± 6.17% CFa, 62.19 ± 7.28% CP, and 14.83 ± 2.66% ash. Concentrations of Arg, Tau, Cys, and Met were 5.63 ± 0.46, 0.92 ± 0.33, 1.91 ± 0.89, and 1.82 ± 0.19 g/16 g N, respectively. Using NRC physiologic fuel values for CP, CFa, and carbohydrate by difference, the combined average energy content of the carcasses was 3,929 kcal/kg DM, but the fiber content was not determined. With the exception of mice and rats, little historical data exist regarding the body and AA composition of many of the species analyzed in this study. Wild-caught mice and rats were composed of less fat but more ash compared with previously reported data in their purpose-bred counterparts. The CP content of mice in this study was similar to previous reports in purpose-bred mice. The CP content of rats was similar or slightly greater compared with historical findings in purpose-bred rats. The N content of rats and AA concentrations on a per-N basis for both rats and mice were similar to previously published data on purpose-bred rodents. The discrepancies in nutrient composition, especially fat concentration, indicate that using purpose-bred animals to represent the diet of the feral domestic

  12. Mean circulatory filling pressure during splanchnic nerve stimulation and whole-body hypoxia in the anaesthetized cat.

    PubMed Central

    Bower, E A; O'Donnell, C P

    1991-01-01

    1. Mean circulatory filling pressure (MCFP) was measured in cats under chloralose anaesthesia by obstruction of blood flow in the pulmonary artery. Pressures in the aorta, hepatic portal vein and right atrium were recorded, and MCFP was estimated from the value at which all three pressures became equal when blood was pumped from aorta to vena cava during circulatory arrest. Simultaneous equality was not attained at MCFP values below 5 mmHg. 2. In cats ventilated by positive pressure after administration of gallamine, MCFP was 9.7 +/- 0.3 mmHg (n = 14). The values of MCFP measured in six cats before and after administration of gallamine did not differ significantly. Change of blood volume altered MCFP linearly over the range 5-21 mmHg. Noradrenaline (7.5 micrograms kg-1 min-1) increased MCFP from 9.3 +/- 0.9 to 16.5 +/- 0.6 mmHg (n = 4), and phentolamine (2 mg kg-1) reduced it to 5.6 +/- 0.3 mmHg (n = 5). 3. Changes in MCFP were evoked at different circulating blood volumes by stimulation of the splanchnic sympathetic nerves and by whole-body hypoxia. Ablation of all splanchnic nerves reduced MCFP from 9.4 +/- 0.5 to 7.1 +/- 0.3 mmHg (n = 5) and stimulation of their distal ends at 10 Hz increased it by 4.1 +/- 0.4 mmHg (n = 4); similar increments were obtained at different blood volumes and initial values of MCFP. 4. Hypoxia increased MCFP by 0.23 mmHg per 1 mmHg fall in arterial oxygen tension below Pa,O2 56 mmHg (r = -0.86; n = 24). Similar increments were obtained at different blood volumes and initial values of MCFP. Ablation of all splanchnic nerves reduced the increments by 60%, and administration of phentolamine abolished them. PMID:1886068

  13. Acetylcholine increases intracellular calcium of arterial chemoreceptor cells of adult cats.

    PubMed

    Shirahata, M; Fitzgerald, R S; Sham, J S

    1997-11-01

    Acetylcholine increases intracellular calcium of arterial chemoreceptor cells of adult cats. J. Neurophysiol. 78: 2388-2395, 1997. Several neurotransmitters have been reported to play important roles in the chemoreception of the carotid body. Among them acetylcholine (ACh) appears to be involved in excitatory processes in the cat carotid body. As one of the steps to elucidate possible roles of ACh in carotid body chemoreception in the cat, we examined the effect of ACh on intracellular calcium concentration ([Ca2+]i) of cultured carotid body cells. The carotid body from adult cats was dissociated and cultured for up to 2 wk. [Ca2+]i was measured from clusters of cells with a microfluorometric technique using Indo-1 AM. Experiments were performed at 37 degrees C, and cells were continuously superfused with modified Krebs solutions equilibrated with 5% CO2-16% O2-79% N2. ACh (100 mu M) caused a marked increase in [Ca2+]i in approximately 70% of clusters, and the responses to 1-300 mu M of ACh were concentration dependent. The magnitude and kinetics of the ACh response were mimicked by the application of nicotine, whereas muscarinic agonists, pilocarpine, and muscarine failed to evoke a similar response. ACh-induced increase in [Ca2+]i was dependent on extracellular Ca2+: it was greatly reduced or completely abolished by a transient removal of extracellular Ca2+. The response was consistently but only partially reduced by caffeine (5 mM) or nifedipine (10 mu M). The effect of mecamylamine (100 mu M) was inhibitory but small. Moreover, the increase in [Ca2+]i in response to ACh was also observed in some clusters that did not respond to high K (100 mM) Krebs. These results suggest that ACh increases [Ca2+]i of cultured carotid body cells by activating neuronal nicotinic ACh receptors, leading to Ca2+ influx via nicotinic channels. In addition, other pathways such as Ca2+ influx through L-type calcium channels, perhaps secondary to membrane depolarization, and Ca2

  14. Oestradiol, but not genistein, inhibits the rise in food intake following gonadectomy in cats, but genistein is associated with an increase in lean body mass.

    PubMed

    Cave, N J; Backus, R C; Marks, S L; Klasing, K C

    2007-10-01

    The prevalence of obesity in domestic cats is increasing worldwide, and is strongly associated with gonadectomy. We have previously demonstrated the effectiveness of oestradiol in reducing food intake in both male and female neutered cats. This experiment was designed to test the hypothesis that oestradiol or genistein would prevent the increase in food intake following gonadectomy of male and female cats, and would prevent an increase in body fat mass. Three groups of eight cats each were surgically neutered then treated daily with either 0.5 mug oestradiol subcutaneously, 100 mg/kg genistein orally, or vehicle only. Effect of treatment on food intake, vaginal cytology and body weight were recorded, and body composition was assayed using the D(2)O isotopic dilution method. Neutering was followed by an increase in food intake, bodyweight and body fat mass in the control group, which were almost completely prevented by treatment with oestradiol (p < 0.001). Treatment with genistein had no effect on food intake or bodyweight increase, but was associated with a significant increase in lean body mass (p = 0.018), and significantly less body fat accumulation than the control group (p = 0.01). There were no significant differences in responses to treatment between sexes. These findings demonstrate the importance of gonadal oestrogen for the control of food intake in male and female cats, and suggest the provision of an oestrogenic compound could help prevent obesity following neutering. In addition, the findings of this study are consistent with observations in rodents of the efficacy of genistein in inhibiting adipogenesis and promoting lean body tissue development.

  15. Dietary fat and carbohydrate have different effects on body weight, energy expenditure, glucose homeostasis and behaviour in adult cats fed to energy requirement.

    PubMed

    Gooding, Margaret A; Atkinson, Jim L; Duncan, Ian J H; Niel, Lee; Shoveller, Anna K

    2015-01-01

    The effects of dietary carbohydrate and fat on feline health are not well understood. The effects of feeding diets moderately high in fat (HF; n 10; 30 % fat, 26 % carbohydrate as fed) or carbohydrate (HC; n 10; 11 % fat, 47 % carbohydrate), for 84 d, were investigated in healthy, adult cats (3·5 (sd 0·5) years). Data on indirect calorimetry, blood biomarkers, activity, play and cognition were collected at baseline, and at intervals throughout the study. Body composition was measured by dual-energy X-ray absorptiometry at baseline and on day 85. There were no significant main effects of diet on body weight and composition. When data were analysed over study day within diet, cats fed HF diets experienced a significant increase in body fat (P = 0·001) and body weight (P = 0·043) in contrast to cats consuming the HC diet that experienced no change in body fat or body weight (P = 0·762) throughout the study. Overall, energy expenditure was similar between diets (P = 0·356 (fasted), P = 0·086 (postprandial)) and respiratory quotient declined with exposure to the HF diet and increased with exposure to the HC diet (P < 0·001; fasted and postprandial). There was no difference in insulin sensitivity as an overall effect of diet (P = 0·266). Activity declined from baseline with exposure to both diets (HC: P = 0·002; HF: P = 0·01) but was not different between diets (P = 0·247). There was no effect of diet on play (P = 0·387) and cats consuming either the HF or HC diet did not successfully learn the cognitive test. Overall, cats adapt to dietary macronutrient content, and the implications of feeding HC and HF diets on risk for adiposity as driven by metabolic and behavioural mechanisms are discussed.

  16. The Mitochondrial SDHD Gene Is Required for Early Embryogenesis, and Its Partial Deficiency Results in Persistent Carotid Body Glomus Cell Activation with Full Responsiveness to Hypoxia

    PubMed Central

    Piruat, José I.; Pintado, C. Oscar; Ortega-Sáenz, Patricia; Roche, Marta; López-Barneo, José

    2004-01-01

    The SDHD gene encodes one of the two membrane-anchoring proteins of the succinate dehydrogenase (complex II) of the mitochondrial electron transport chain. This gene has recently been proposed to be involved in oxygen sensing because mutations that cause loss of its function produce hereditary familiar paraganglioma, a tumor of the carotid body (CB), the main arterial chemoreceptor that senses oxygen levels in the blood. Here, we report the generation of a SDHD knockout mouse, which to our knowledge is the first mammalian model lacking a protein of the electron transport chain. Homozygous SDHD−/− animals die at early embryonic stages. Heterozygous SDHD+/− mice show a general, noncompensated deficiency of succinate dehydrogenase activity without alterations in body weight or major physiological dysfunction. The responsiveness to hypoxia of CBs from SDHD+/− mice remains intact, although the loss of an SDHD allele results in abnormal enhancement of resting CB activity due to a decrease of K+ conductance and persistent Ca2+ influx into glomus cells. This CB overactivity is linked to a subtle glomus cell hypertrophy and hyperplasia. These observations indicate that constitutive activation of SDHD+/− glomus cells precedes CB tumor transformation. They also suggest that, contrary to previous beliefs, mitochondrial complex II is not directly involved in CB oxygen sensing. PMID:15572694

  17. Carotid bypass for carotid occlusion.

    PubMed

    Hage, Ziad A; Behbahani, Mandana; Amin-Hanjani, Sepideh; Charbel, Fady T

    2015-07-01

    The 2-year risk of ipsilateral ischemic stroke following internal carotid artery occlusion (ICAO) in a patient undergoing maximal medical therapy is 5-8% per year. While medical therapy may reduce the risk of stroke, it does not completely eliminate it. Since the 1985 extracranial-intracranial (EC-IC) bypass study, additional trials have been conducted to further investigate the usefulness of EC-IC bypass surgery in more selected patients with cerebral ischemia and impaired hemodynamic reserve. These important studies will be briefly reviewed in this article, as well as a discussion regarding the utility of bypass surgery for ICAO in current clinical practice. In addition, a short discussion regarding the pathophysiology of carotid occlusion will be presented. We will also highlight our own institutional patient selection criteria based on the latest methods for hemodynamic assessment, as well as our intraoperative flow assisted surgical techniques (FAST), and post-operative patient follow-up.

  18. Carotid artery stenting versus carotid endarterectomy.

    PubMed

    Nanna, Michael G; Gomes, Paulina; Njoh, Roland F; Ward, Charisse; Attaran, Robert R; Mena, Carlos

    2016-09-01

    Stroke remains a significant contributor to morbidity and mortality in developed countries. Carotid artery stenosis is a major cause of stroke. Advances in medical therapy, surgical technique and endovascular maturation has resulted in options for the treatment of carotid stenosis. Here, we present a review of carotid artery stenting and carotid endarterectomy as it applies to trials comparing and contrasting the two treatment options. We also explore the intricacies surrounding reimbursement of these treatment strategies in the USA.

  19. 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.

  20. The CamKKβ Inhibitor STO609 Causes Artefacts in Calcium Imaging and Selectively Inhibits BKCa in Mouse Carotid Body Type I Cells.

    PubMed

    Jurcsisn, Jennifer G; Pye, Richard L; Ali, Jon; Barr, Barbara L; Wyatt, Christopher N

    2015-01-01

    It has previously been reported that AMP-activated protein kinase (AMPK) may be critical for hypoxic chemotransduction in carotid body type I cells. This study sought to determine the importance of the regulatory upstream kinase of AMPK, CamKKβ, in the acute response to hypoxia in isolated mouse type I cells.Initial data indicated several previously unreported artefacts associated with using the CamKKβ inhibitor STO609 and Ca(2+) imaging techniques. Most importantly Fura-2 and X-Rhod1 imaging revealed that STO609 quenched emission fluorescence even in the absence of intracellular Ca(2+) ([Ca(2+)](I)). Furthermore, STO609 (100 μM) rapidly inhibited outward macroscopic currents and this inhibition was abolished in the presence of the selective BK(Ca) inhibitor paxilline.Taken together these data suggest that ST0609 should be used with caution during Ca(2+) imaging studies as it can directly interact with Ca(2+) binding dyes. The rapid inhibitory effect of STO609 on BK(Ca) was unexpected as the majority of studies using this compound required an incubation of approximately 10 min to inhibit the kinase. Furthermore, as AMPK activation inhibits BK(Ca), inhibiting AMPK's upstream kinases would, if anything, be predicted to have the opposite effect on BK(Ca). Future work will determine if the inhibition of BK(Ca) is via CamKKβ or via an off target action of STO609 on the channel itself.

  1. 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.

  2. Dependence of carotid chemosensory responses on metabolic substrates.

    PubMed

    Spergel, D; Lahiri, S; Wilson, D F

    1992-11-20

    The dependence of the carotid chemosensory response to hypoxia on metabolic substrate and the hypothesis that lactic acidosis is essential for O2 chemoreception were tested. Effects of 3 types of substrate (glucose, glutamate and a mixture of amino acids) on the response to hypoxia (perfusate flow interruption) were measured (n = 33 carotid bodies). The response to nicotine (n = 25) was used to determine whether these effects were exclusive to the hypoxic response. The cat carotid body was perfused and superfused in vitro with modified Tyrode solution (pO2 > 400 Torr, pCO2 < 1 Torr, pH = 7.4) at 36 degrees C containing a given substrate for at least 15 min prior to flow interruption or nicotine injection. Without substrate, responses to flow interruption (n = 4) and nicotine (n = 2) were irreversibly depressed. With glucose, responses to flow interruption (n = 13) and nicotine (n = 8) increased in a concentration-dependent fashion. Glutamate (42 mM) alone (n = 11) or a mixture of amino acids (4.2 mM) plus 5.5 mM glucose (n = 12) substituted for 11 mM glucose (n = 10). Thus, glutamate (42 mM), or a mixture of amino acids (4.2 mM) or a high concentration of glucose (11 mM) can support chemosensory responses to flow interruption and nicotine. Since glutamate undergoes oxidative deamination to alpha-ketoglutarate without lactic acid production, O2 chemoreception does not depend on lactic acidosis.

  3. Directionality derived from differential sensitivity to monaural and binaural cues in the cat's medial geniculate body.

    PubMed

    Samson, F K; Barone, P; Irons, W A; Clarey, J C; Poirier, P; Imig, T J

    2000-09-01

    Azimuth tuning of high-frequency neurons in the primary auditory cortex (AI) is known to depend on binaural disparity and monaural spectral (pinna) cues present in broadband noise bursts. Single-unit response patterns differ according to binaural interactions, strength of monaural excitatory input from each ear, and azimuth sensitivity to monaural stimulation. The latter characteristic has been used as a gauge of neural sensitivity to monaural spectral directional cues. Azimuth sensitivity may depend predominantly on binaural disparity cues, exclusively on monaural spectral cues, or on both. The primary goal of this study was to determine whether each cortical response pattern corresponds to a similar pattern in the medial geniculate body (MGB) or whether some patterns are unique to the cortex. Single-unit responses were recorded from the ventral nucleus (Vn) and lateral part of the posterior group of thalamic nuclei (Po), tonotopic subdivisions of the MGB. Responses to free-field presentation of noise bursts that varied in azimuth and sound pressure level were obtained using methods identical to those used previously in field AI. Many units were azimuth sensitive, i.e., they responded well at some azimuths, and poorly, if at all, at others. These were studied further by obtaining responses to monaural noise stimulation, approximated by reversible plugging of one ear. Monaural directional (MD) cells were sensitive to the azimuth of monaural noise stimulation, whereas binaural directional (BD) cells were either insensitive to its azimuth or monaurally unresponsive. Thus BD and MD cells show differential sensitivity to monaural spectral cues. Monaural azimuth sensitivity could not be used to interpret the spectral sensitivity of predominantly binaural cells that exhibited strong binaural facilitation because they were either unresponsive or poorly responsive to monaural stimulation. The available evidence suggests that some such cells are sensitive to spectral cues

  4. 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.

  5. Carotid baroreflex control of heart rate is enhanced, while control of mean arterial pressure is preserved during whole-body heat stress in young healthy men.

    PubMed

    Krnjajic, Davor; Allen, Dustin R; Butts, Cory L; Keller, David M

    2016-08-03

    Whole-body heat stress (WBH) results in numerous cardiovascular alterations that ultimately reduce orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported as a potential reason for this decrement, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in ten healthy male subjects (age, 26 ± 3; height, 185 ± 7 cm; weight, 82 ± 10 kg; BMI, 24 ± 3 kg/m(2); mean ± sd) using 5 s trials of neck pressure (+45, +30 and +15 Torr) and neck suction (-20, -40, -60 and -80 Torr) during normothermia (NT) and passive WBH (∆ core temp ~1 °C). Analyses of stimulus response curves (four parameter logistic model) for CBR control of heart rate (CBR-HR) and mean arterial pressure (CBR-MAP), as well as separate 2-way ANOVA of the hypo- and hypertensive stimuli (factor 1: thermal condition, factor 2: chamber pressure) were performed. For CBR-HR, maximal gain was increased during WBH (-0.73±0.11) compared to NT (-0.39±0.04, mean±SE, p=0.03). In addition, the CBR-HR responding range was increased during WBH (33±5) compared to NT (19±2 bpm, p=0.03). Separate analysis of hypertensive stimulation revealed enhanced HR responses during WBH at -40, -60 and -80 Torr (condition*chamber pressure interaction, p=0.049) compared to NT. For CBR-MAP, both logistic analysis and separate 2-way ANOVA revealed no differences during WBH. Therefore, in response to passive WBH, CBR control of heart rate (enhanced) and arterial pressure (no change) is well-preserved.

  6. BDNF and AMPA receptors in the cNTS modulate the hyperglycemic reflex after local carotid body NaCN stimulation.

    PubMed

    Cuéllar, R; Montero, S; Luquín, S; García-Estrada, J; Melnikov, V; Virgen-Ortiz, A; Lemus, M; Pineda-Lemus, M; de Álvarez-Buylla, E

    2017-02-03

    The application of sodium cyanide (NaCN) to the carotid body receptors (CBR) (CBR stimulation) induces rapid blood hyperglycemia and an increase in brain glucose retention. The commissural nucleus tractus solitarius (cNTS) is an essential relay nucleus in this hyperglycemic reflex; it receives glutamatergic afferents (that also release brain derived neurotrophic factor, BDNF) from the nodose-petrosal ganglia that relays CBR information. Previous work showed that AMPA in NTS blocks hyperglycemia and brain glucose retention after CBR stimulation. In contrast, BDNF, which attenuates glutamatergic AMPA currents in NTS, enhances these glycemic responses. Here we investigated the combined effects of BDNF and AMPA (and their antagonists) in NTS on the glycemic responses to CBR stimulation. Microinjections of BDNF plus AMPA into the cNTS before CBR stimulation in anesthetized rats, induced blood hyperglycemia and an increase in brain arteriovenous (a-v) of blood glucose concentration difference, which we infer is due to increased brain glucose retention. By contrast, the microinjection of the TrkB antagonist K252a plus AMPA abolished the glycemic responses to CBR stimulation similar to what is observed after AMPA pretreatments. In BDNF plus AMPA microinjections preceding CBR stimulation, the number of c-fos immunoreactive cNTS neurons increased. In contrast, in the rats microinjected with K252a plus AMPA in NTS, before CBR stimulation, c-fos expression in cNTS decreased. The expression of AMPA receptors GluR2/3 did not change in any of the studied groups. These results indicate that BDNF in cNTS plays a key role in the modulation of the hyperglycemic reflex initiated by CBR stimulation.

  7. Oxygen and mitochondrial inhibitors modulate both monomeric and heteromeric TASK-1 and TASK-3 channels in mouse carotid body type-1 cells

    PubMed Central

    Turner, Philip J; Buckler, Keith J

    2013-01-01

    In rat arterial chemoreceptors, background potassium channels play an important role in maintaining resting membrane potential and promoting depolarization and excitation in response to hypoxia or acidosis. It has been suggested that these channels are a heterodimer of TASK-1 and TASK-3 based on their similarity to heterologously expressed TASK-1/3 fusion proteins. In this study, we sought to confirm the identity of these channels through germline ablation of Task-1 (Kcnk3) and Task-3 (Kcnk9) in mice. Background K-channels were abundant in carotid body type-1 cells from wild-type mice and comparable to those previously described in rat type-1 cells with a main conductance state of 33 pS. This channel was absent from both Task-1−/− and Task-3−/− cells. In its place we observed a larger (38 pS) K+-channel in Task-1−/− cells and a smaller (18 pS) K+-channel in Task-3−/− cells. None of these channels were observed in Task-1−/−/Task-3−/− double knock-out mice. We therefore conclude that the predominant background K-channel in wild-type mice is a TASK-1/TASK-3 heterodimer, whereas that in Task-1−/− mice is TASK-3 and, conversely, that in Task-3−/− mice is TASK-1. All three forms of TASK channel in type-1 cells were inhibited by hypoxia, cyanide and the uncoupler FCCP, but the greatest sensitivity was seen in TASK-1 and TASK-1/TASK-3 channels. In summary, the background K-channel in type-1 cells is predominantly a TASK-1/TASK-3 heterodimer. Although both TASK-1 and TASK-3 are able to couple to the oxygen and metabolism sensing pathways present in type-1 cells, channels containing TASK-1 appear to be more sensitive. PMID:24042502

  8. 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

  9. Molecular identification and functional role of voltage-gated sodium channels in rat carotid body chemoreceptor cells. Regulation of expression by chronic hypoxia in vivo.

    PubMed

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

    2007-07-01

    We have assessed the expression, molecular identification and functional role of Na+ channels (Na(v)) in carotid bodies (CB) obtained from normoxic and chronically hypoxic adult rats. Veratridine evoked release of catecholamines (CA) from an in vitro preparation of intact CBs obtained from normoxic animals, the response being Ca2+ and Na+-dependent and sensitive to tetrodotoxin (TTX). TTX inhibited by 25-50% the CA release response evoked by graded hypoxia. Immunoblot assays demonstrated the presence of Na(v)alpha-subunit (c. 220 kDa) in crude homogenates from rat CBs, being evident an up-regulation (60%) of this protein in the CBs obtained from chronically hypoxic rats (10% O2; 7 days). This up-regulation was accompanied by an enhanced TTX-sensitive release response to veratridine, and by an enhanced ventilatory response to acute hypoxic stimuli. RT-PCR studies demonstrated the expression of mRNA for Na(v)1.1, Na(v)1.2, Na(v)1.3, Na(v)1.6 and Na(v)1.7 isoforms. At least three isoforms, Na(v)1.1, Na(v)1.3 and Na(v)1.6 co-localized with tyrosine hydroxylase in all chemoreceptor cells. RT-PCR and immunocytochemistry indicated that Na(v)1.1 isoform was up-regulated by chronic hypoxia in chemoreceptor cells. We conclude that Na(v) up-regulation represents an adaptive mechanism to increase chemoreceptor sensitivity during acclimatization to sustained hypoxia as evidenced by enhanced ventilatory responses to acute hypoxic tests.

  10. 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 ...

  11. Carotid artery surgery - slideshow

    MedlinePlus

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

  12. Autonomic control of the cardiovascular system in the cat during hypoxemia.

    PubMed

    Fitzgerald, Robert S; Dehghani, Gholam Abbas; Kiihl, Samara

    2013-03-01

    This study aimed to determine the roles played by the autonomic interoreceptors, the carotid bodies (cbs) and the aortic bodies (abs) in anesthetized, paralyzed, artificially ventilated cats' response to systemic hypoxemia. Four 15min challenges stimulated each of 15 animals: (1) hypoxic hypoxia (10%O₂ in N₂; HH) in the intact (int) cat where both abs and cbs sent neural traffic to the nucleus tractus solitarius (NTS); (2) carbon monoxide hypoxia (30%O₂ in N₂ with the addition of CO; COH) in the intact cat where only the abs sent neural traffic to the NTS; (3) HH in the cat after transection of both aortic depressor nerves, resecting the aortic bodies (HHabr), where only the cbs sent neural traffic to the NTS; (4) COH to the abr cat where neither abs nor cbs sent neural traffic to the NTS. Cardiac output (C.O.), contractility (dP/dt(MAX)), systolic/diastolic pressures, aortic blood pressure, total peripheral resistance, pulmonary arterial pressure, and pulmonary vascular resistance (PVR) were measured. When both cbs and abs were active the maximum increases were observed except for PVR which decreased. Some variables showed the cbs to have a greater effect than the abs. The abs proved to be important during some challenges for maintaining blood pressure. The data support the critically important role for the chemoreceptor-sympathetic nervous system connection during hypoxemia for maintaining viable homeostasis, with some differences between the cbs and the abs.

  13. Body CT (CAT Scan)

    MedlinePlus

    ... lives. CT has been shown to be a cost-effective imaging tool for a wide range of ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  14. Body Condition Scores and Evaluation of Feeding Habits of Dogs and Cats at a Low Cost Veterinary Clinic and a General Practice.

    PubMed

    Sapowicz, Stephanie A; Linder, Deborah E; Freeman, Lisa M

    2016-01-01

    This study assessed body condition scores (BCS) and feeding habits for dogs and cats. Eighty-six cats and 229 dogs (and their owners) were enrolled from 2 clinics: a low cost clinic (n = 149) and a general practice (n = 166). BCS and body weight were recorded. Owners completed a survey which included animal age, sex, and breed; owner demographics; and feeding practices (e.g., diet, rationale for feeding practices). Owners from the low cost clinic had a significantly lower income (P < 0.001) and education (P < 0.001) compared to those from the general practice. Animals from the low cost clinic were younger (P < 0.001) and dogs were less likely to be neutered (P < 0.001). Overweight prevalence was 55% overall (P = 0.083), with a significantly higher prevalence in the general practice for cats (44% versus 66%; P = 0.046), but not for dogs (58% versus 53%; P = 0.230). Multivariate analysis showed that only neuter status was significantly associated with BCS (P = 0.004). Veterinarians were the most common source of nutritional information, though lack of accurate nutrition knowledge was common among all participants. These findings support the need for enhanced communication about optimal BCS and nutrition regardless of socioeconomic status.

  15. Body Condition Scores and Evaluation of Feeding Habits of Dogs and Cats at a Low Cost Veterinary Clinic and a General Practice

    PubMed Central

    2016-01-01

    This study assessed body condition scores (BCS) and feeding habits for dogs and cats. Eighty-six cats and 229 dogs (and their owners) were enrolled from 2 clinics: a low cost clinic (n = 149) and a general practice (n = 166). BCS and body weight were recorded. Owners completed a survey which included animal age, sex, and breed; owner demographics; and feeding practices (e.g., diet, rationale for feeding practices). Owners from the low cost clinic had a significantly lower income (P < 0.001) and education (P < 0.001) compared to those from the general practice. Animals from the low cost clinic were younger (P < 0.001) and dogs were less likely to be neutered (P < 0.001). Overweight prevalence was 55% overall (P = 0.083), with a significantly higher prevalence in the general practice for cats (44% versus 66%; P = 0.046), but not for dogs (58% versus 53%; P = 0.230). Multivariate analysis showed that only neuter status was significantly associated with BCS (P = 0.004). Veterinarians were the most common source of nutritional information, though lack of accurate nutrition knowledge was common among all participants. These findings support the need for enhanced communication about optimal BCS and nutrition regardless of socioeconomic status. PMID:27722198

  16. [Conditioned reflex changes in the intra-analyzer interaction of the afferent inputs from the lateral geniculate body and pulvinar thalami in the cerebral cortex of cats].

    PubMed

    Shumikhina, S I

    1986-01-01

    Paired heterogeneous stimulation of the lateral geniculate body (LGB) and pulvinar (Pulv) as a conditioned stimulus of alimentary instrumental conditioned reflex (CR), resulted in a change of relations between afferent inputs from LGB and Pulv to the visual and associative cortex of cats. At stimulation of LGB preceding by 40 ms, facilitation of the response to testing Pulv stimulation observed in untrained cats, appeared only at the beginning of the learning and was suppressed by the end of elaboration, when the amplitude of the response to the conditioning LGB stimulation greatly increased. In the process of CR elaboration (in the middle of learning), Pulv stimulation preceding by 40 ms facilitated the response to the testing LGB stimulation and simultaneously increased the amplitude of the response to the conditioning Pulv stimulation.

  17. P2Y2 receptor activation opens pannexin-1 channels in rat carotid body type II cells: potential role in amplifying the neurotransmitter ATP

    PubMed Central

    Zhang, Min; Piskuric, Nikol A; Vollmer, Cathy; Nurse, Colin A

    2012-01-01

    Signal processing in the carotid body (CB) is initiated at receptor glomus (or type I) cells which depolarize and release the excitatory neurotransmitter ATP during chemoexcitation by hypoxia and acid hypercapnia. Glomus cell clusters (GCs) occur in intimate association with glia-like type II cells which express purinergic P2Y2 receptors (P2Y2Rs) but their function is unclear. Here we immunolocalize the gap junction-like protein channel pannexin-1 (Panx-1) in type II cells and show Panx-1 mRNA expression in the rat CB. As expected, type II cell activation within or near isolated GCs by P2Y2R agonists, ATP and UTP (100 μm), induced a rise in intracellular [Ca2+]. Moreover in perforated-patch whole cell recordings from type II cells, these agonists caused a prolonged depolarization and a concentration-dependent, delayed opening of non-selective ion channels that was prevented by Panx-1 blockers, carbenoxolone (5 μm) and 4,4′-diisothiocyano-2,2′-stilbenedisulfonic acid (DIDS; 10 μm). Because Panx-1 channels serve as conduits for ATP release, we hypothesized that paracrine, type II cell P2Y2R activation leads to ATP-induced ATP release. In proof-of-principle experiments we used co-cultured chemoafferent petrosal neurones (PNs), which express P2X2/3 purinoceptors, as sensitive biosensors of ATP released from type II cells. In several cases, UTP activation of type II cells within or near GCs led to depolarization or increased firing in nearby PNs, and the effect was reversibly abolished by the selective P2X2/3 receptor blocker, pyridoxalphosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS; 10 μm). We propose that CB type II cells may function as ATP amplifiers during chemotransduction via paracrine activation of P2Y2Rs and Panx-1 channels. PMID:22733659

  18. Effects of the removal of extracellular Ca2+ on [Ca2+]i responses to FCCP and acetate in carotid body glomus cells of adult rabbits.

    PubMed

    Sato, M

    1997-09-12

    The effects of the removal of extracellular Ca2+ on the responses of cytosolic concentrations of Ca2+ ([Ca2+]i) to acidic stimuli, a protonophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) and an organic acid acetate, were examined in clusters of cultured carotid body glomus cells of adult rabbits using fura-2 microfluorometry. Application of FCCP (1 microM) induced an increase in [Ca2+]i (mean +/- S.E.M., 108 +/- 14%). After withdrawal of the protonophore the increased [Ca2+]i returned slowly to a resting level. The [Ca2+]i response was attenuated by an inorganic Ca2+ channel antagonist Ni2+ (2 mM) by 81 +/- 4%, and by an L-type voltage-gated Ca2+ channel antagonist D600 (10 microM) by 53 +/- 13%. The removal of extracellular Ca2+ eliminated the [Ca2+]i response in 71% of the tested cells (n = 17), and depressed it by 68 +/- 6% in the rest. Recovery following stimulation with FCCP in the absence of Ca2+ reversibly produced a rapid and large rise in [Ca2+]i, referred to as a [Ca2+]i rise after Ca2+-free/FCCP. The magnitude of a [Ca2+]i rise after Ca2+-free/FCCP (285 +/- 28%, P < 0.05) was larger than that of an increase in [Ca2+]i induced by FCCP in the presence of Ca2+ and had a correlation with the intensity of the suppression of the [Ca2+]i response by Ca2+ removal. A [Ca2+]i rise after Ca2+-free/FCCP was inhibited mostly by D600. Similarly, recovery following exposure to acetate in the absence of Ca2+ caused a rise in [Ca2+]i, referred to as a [Ca2+]i rise after Ca2+-free/acetate which was sensitive to D600. The magnitude of the [Ca2+]i rise was larger than that of a change in [Ca2+]i caused by acetate in the presence of Ca2+. These results suggest that FCCP-induced increase in [Ca2+]i was, in most cells, due to Ca2+ influx via L-type voltage-gated Ca2+ channels and, in some cells, due to both Ca2+ influx and Ca2+ release from internal Ca2+ pool. The removal of extracellular Ca2+ might modify [Ca2+]i responses to acidic stimuli, causing [Ca2+]i

  19. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats

    PubMed Central

    Hoelmkjaer, Kirsten M.; Wewer Albrechtsen, Nicolai J.; Holst, Jens J.; Cronin, Anna M.; Nielsen, Dorte H.; Mandrup-Poulsen, Thomas; Bjornvad, Charlotte R.

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats. PMID:27136422

  20. Metabolic determinants of body weight after cats were fed a low-carbohydrate high-protein diet or a high-carbohydrate low-protein diet ad libitum for 8 wk.

    PubMed

    Coradini, M; Rand, J S; Morton, J M; Rawlings, J M

    2014-10-01

    Overweight and obese conditions are common in cats and are associated with the development of a number of diseases. Knowledge of metabolic determinants and predictors of weight gain may enable better preventative strategies for obesity in cats. Lean, healthy cats were fed either a low-carbohydrate high-protein diet (n 16) or a high-carbohydrate low-protein (n 16) diet ad libitum for 8 wk. Potential determinants and predictors of final body weight assessed were body fat and lean masses, energy required for maintenance, energy requirements above maintenance for each kilogram of weight gain, insulin sensitivity index, fasting, mean 24-h and peak plasma glucose, insulin, and leptin concentrations, and fasting and mean 24-h serum adiponectin concentrations. In cats fed the low-carbohydrate high-protein diet, after adjusting for initial body weight, those with higher energy requirements for weight gain and higher fasting glucose concentration had higher final body weights (P ≤ 0.01). Predicted final body weights using initial body weight, fasting glucose and mean 24-h insulin concentrations (partial R(2) 37.3%) were imprecise. An equation using just initial body weight and fasting glucose concentration would be of more practical value, but was marginally less precise. In cats fed the high-carbohydrate low-protein diet, those with lower fasting leptin concentration initially had higher final body weights (P = 0.01). Predicted final body weights using initial body weight, energy requirements for maintenance, total body fat percentage and fasting leptin concentration (partial R(2) 39.2%) were reasonably precise. Further studies are warranted to confirm these findings and to improve the precision of predicted final body weights.

  1. 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 . ...

  2. What Is 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 ...

  3. 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.

  4. Carotid Artery Screening

    MedlinePlus

    ... plaque and the injury it causes is called atherosclerosis . Over time, the walls of affected arteries thicken ... disease (CAD) obesity physical inactivity family history of atherosclerosis and/or stroke Screening Recommendations Carotid Duplex US ...

  5. Carotid Artery Disease

    MedlinePlus

    ... sites within the artery. This process is called atherosclerosis. Carotid arteries that are clogged with plaques are ... at greater risk of high blood pressure and atherosclerosis. High blood-fat levels. High levels of low- ...

  6. Carotid artery disease

    MedlinePlus

    ... a stroke recover most or all of their functions. Others die of the stroke itself or from complications. About half of people ... patients with extracranial carotid and vertebral artery disease: executive summary: ... American Association of Neuroscience Nurses, American Association ...

  7. Cat Batiks.

    ERIC Educational Resources Information Center

    Buban, Marcia H.

    1998-01-01

    Discusses an art activity where fourth-grade students created backgrounds using melted paraffin and a variety of paints for their cat batik/collage. Explains that after the students created their backgrounds, they assembled their paper cats for the collage using smaller shapes glued together and wax to add texture for fur. (CMK)

  8. Muscle spindle responses to horizontal support surface perturbation in the anesthetized cat: insights into the role of autogenic feedback in whole body postural control.

    PubMed

    Honeycutt, Claire F; Nardelli, Paul; Cope, Timothy C; Nichols, T Richard

    2012-09-01

    Intact cats and humans respond to support surface perturbations with broadly tuned, directionally sensitive muscle activation. These muscle responses are further sensitive to initial stance widths (distance between feet) and perturbation velocity. The sensory origins driving these responses are not known, and conflicting hypotheses are prevalent in the literature. We hypothesize that the direction-, stance-width-, and velocity-sensitive muscle response during support surface perturbations is driven largely by rapid autogenic proprioceptive pathways. The primary objective of this study was to obtain direct evidence for our hypothesis by establishing that muscle spindle receptors in the intact limb can provide appropriate information to drive the muscle response to whole body postural perturbations. Our second objective was to determine if spindle recordings from the intact limb generate the heightened sensitivity to small perturbations that has been reported in isolated muscle experiments. Maintenance of this heightened sensitivity would indicate that muscle spindles are highly proficient at detecting even small disturbances, suggesting they can provide efficient feedback about changing postural conditions. We performed intraaxonal recordings from muscle spindles in anesthetized cats during horizontal, hindlimb perturbations. We indeed found that muscle spindle afferents in the intact limb generate broadly tuned but directionally sensitive activation patterns. These afferents were also sensitive to initial stance widths and perturbation velocities. Finally, we found that afferents in the intact limb have heightened sensitivity to small perturbations. We conclude that muscle spindle afferents provide an array of important information about biomechanics and perturbation characteristics highlighting their potential importance in generating appropriate muscular response during a postural disturbance.

  9. Muscle spindle responses to horizontal support surface perturbation in the anesthetized cat: insights into the role of autogenic feedback in whole body postural control

    PubMed Central

    Nardelli, Paul; Cope, Timothy C.; Nichols, T. Richard

    2012-01-01

    Intact cats and humans respond to support surface perturbations with broadly tuned, directionally sensitive muscle activation. These muscle responses are further sensitive to initial stance widths (distance between feet) and perturbation velocity. The sensory origins driving these responses are not known, and conflicting hypotheses are prevalent in the literature. We hypothesize that the direction-, stance-width-, and velocity-sensitive muscle response during support surface perturbations is driven largely by rapid autogenic proprioceptive pathways. The primary objective of this study was to obtain direct evidence for our hypothesis by establishing that muscle spindle receptors in the intact limb can provide appropriate information to drive the muscle response to whole body postural perturbations. Our second objective was to determine if spindle recordings from the intact limb generate the heightened sensitivity to small perturbations that has been reported in isolated muscle experiments. Maintenance of this heightened sensitivity would indicate that muscle spindles are highly proficient at detecting even small disturbances, suggesting they can provide efficient feedback about changing postural conditions. We performed intraaxonal recordings from muscle spindles in anesthetized cats during horizontal, hindlimb perturbations. We indeed found that muscle spindle afferents in the intact limb generate broadly tuned but directionally sensitive activation patterns. These afferents were also sensitive to initial stance widths and perturbation velocities. Finally, we found that afferents in the intact limb have heightened sensitivity to small perturbations. We conclude that muscle spindle afferents provide an array of important information about biomechanics and perturbation characteristics highlighting their potential importance in generating appropriate muscular response during a postural disturbance. PMID:22673334

  10. [Carotid ultrasonography: evaluation of carotid ultrasonography].

    PubMed

    Taniuchi, Ryosui

    2007-02-01

    Carotid ultrasonography is a laboratory procedure showing how arteriosclerosis screening can diagnose carotid artery occlusion and high-grade stenosis. It is useful for inspection in general practice because of its non-invasiveness, development of sonography equipment, laboratory methods and the establishment of an evaluation method. We generally use a linear array probe of around 7-8MHz for carotid observation and combine the B mode method, color and power Doppler method, and pulsed Doppler method for inspection. At vessel analysis, the intima-media thickness, the property of plaque and stenotic ratio are evaluated. We observe the direction of bloodstream and presence of stricture by Doppler color flow imaging and measure flow velocity and the wave pattern by pulsed Doppler method and, with the B mode method, evaluate the extent or degree of stricture. This can be depicted well using a convex array probe and sector array probe when the mental change caused by disease is deep, and depiction is difficult by linear array probe.

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

    PubMed Central

    Garfia, A

    1980-01-01

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

  12. Astronomy CATS

    NASA Astrophysics Data System (ADS)

    Brissenden, Gina; Prather, Edward E.; Impey, Chris

    2012-08-01

    The Center for Astronomy Education's (CAE's) NSF-funded Collaboration of Astronomy Teaching Scholars (CATS) Program is a grassroots multi-institutional effort to increase the capacity for astronomy education research and improve science literacy in the United States.Our primary target population is the 500,000 college students who each year enroll in an introductory general education (a breadth requirement for non-science majors) Earth, Astronomy, and Space Science (EASS) course (Fraknoi 2001, AGI 2006).An equally important population for our efforts is the individuals who are, or will be, teaching these students. In this chapter, we will briefly discuss the goals of CAE and CATS, the varied personnel that make up the CATS collective, the diverse projects we've undertaken, and the many challenges we have had to work through to make CATS a success.

  13. 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 ...

  14. Hearing disorders in cats.

    PubMed

    Strain, George M

    2017-03-01

    Practical relevance: Auditory function is a sense that is central to life for cats - being important in situational awareness of potential predators, pursuit of prey, and for communication with conspecifics, humans and other species. Deafness in cats is most frequently the result of a genetic disorder, strongly associated with white fur and blue eyes, but may also result from acquired causes such as advancing age, ototoxic drugs, infection, environmental noise and physical trauma. Deafness can be sensorineural, where there is loss of cochlear hair cells, or conductive, where sound is muffled on its way to the inner ear. Clinical challenges: Establishing whether a cat is deaf can be difficult as behavioral testing of hearing is subjective and does not reliably detect unilateral deafness. Brainstem auditory evoked response testing is an objective measure but is limited in its availability. Currently, sensorineural deafness is irreversible because no treatments are available to restore lost hair cells. Conductive hearing loss can usually be treated, although full hearing recovery following otitis media may take weeks as the body clears the middle ear of debris. Evidence base: The author draws on the published literature and his extensive research on clinical aspects and molecular genetics of deafness, principally in companion animals, to review types and forms of deafness in cats. He also discusses current diagnostic approaches and provides brief advice for managing cats with hearing loss.

  15. [Grafting of carotid arteries].

    PubMed

    Belov, Iu V; Stepanenko, A B; Gens, A P; Bazylev, V V; Seleznev, M N; Savichev, D D

    2005-01-01

    Over 5-years, 167 reconstructive surgeries for stenosis of internal carotid arteries (ICA) were performed in 124 patients. Mean age of the patients was 63.5 years. One hundred and twenty-nine carotid endarterectomies (CEAE) in 86 patients and 38 reconstructive operations of ICA in 38 patients were performed. There were no lethal outcomes in short- and long-term postoperative period. In short-term period after prosthesis of ICA restenosis was revealed in 3% patients, after eversion CEAE in 3% patients the embolism was seen, after standard CEAE restenosis were diagnosed in 8% patients and thrombosis -- in 3%. In long-term period after grafting of ICA the strokes were seen in 3%, stenosis -- in 6% patients, after eversion endarterectomy -- in 0 and 3% patients, and after standard CEAE -- in 3 and 24% patients, respectively. It is concluded that grafting of ICA is adequate surgical method of reconstruction and stroke prevention in specific variants of carotid atherosclerosis.

  16. 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 ...

  17. Carotid artery surgery

    MedlinePlus

    ... may help lower your chance of having a stroke. But you will need to make lifestyle changes to help prevent plaque buildup, blood clots, and other problems in your carotid arteries over time. You may need to change your diet and start an exercise program, if your doctor tells you exercise is ...

  18. Idiopathic generalised tremor syndrome in two cats.

    PubMed

    Mauler, Daniela A; Van Soens, Iris; Bhatti, Sofie F; Cornelis, Ine; Martlé, Valentine A; Van Ham, Luc M

    2014-04-01

    Two male neutered domestic shorthair cats were evaluated for generalised tremors. On neurological examination both cats showed whole-body tremors, worsening with stress. A mainly cerebellar disorder was suspected. Blood examination, cerebrospinal fluid analysis and electrophysiological examination of both cats and magnetic resonance imaging of the brain in one cat were normal. Idiopathic generalised tremor syndrome (IGTS) was suspected owing to the exclusion of underlying causes and the clinical similarities with the syndrome in dogs. Treatment as recommended for dogs was initiated and resulted in improvement. This report describes the first cases of IGTS in cats.

  19. Cat scratch disease (image)

    MedlinePlus

    Cat scratch disease is an infectious illness associated with cat scratches, bites, or exposure to cat saliva, causing chronic swelling of the lymph nodes. Cat scratch disease is possibly the most common cause of chronic ...

  20. Cat and Dog Bites

    MedlinePlus

    ... Prevention and Wellness Staying Healthy Pets and Animals Cat and Dog Bites Cat and Dog Bites Pets and AnimalsPrevention and WellnessStaying Healthy Share Cat and Dog Bites Cat and dog bites are ...

  1. 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.

  2. 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

  3. How Is Carotid Artery Disease Treated?

    MedlinePlus

    ... from the NHLBI on Twitter. How Is Carotid Artery Disease Treated? Treatments for carotid artery disease may ... plaque removed and normal blood flow restored. Carotid Artery Angioplasty and Stenting Doctors use a procedure called ...

  4. 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 ...

  5. Obesity and carotid artery remodeling

    PubMed Central

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

    2015-01-01

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

  6. Cat scratch disease.

    PubMed

    Bozhkov, V; Madjov, R; Plachkov, I; Arnaudov, P; Chernopolsky, P; Krasnaliev, I

    2014-01-01

    Approximately 24,000 people are infected with cat scratch disease (CSD) every year. CSD is caused by the bacteria Bartonella henselae, a gram-negative bacteria most often transmitted to humans through a bite or scratch from an infected cat or kitten. Although CSD is often a benign and self-limiting condition, it can affect any major organ system in the body, manifesting in different ways and sometimes leading to lifelong sequelae. It is a disease that is often overlooked in primary care because of the wide range of symptom presentation and relative rarity of serious complications. It is important for health care providers to recognize patients at risk for CSD, know what laboratory testing and treatments are available, and be aware of complications that may arise from this disease in the future.

  7. 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

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

    PubMed Central

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

    2009-01-01

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

  9. Cool Cats: Feline Fun with Abstract Art.

    ERIC Educational Resources Information Center

    Lambert, Phyllis Gilchrist

    2002-01-01

    Presents a lesson that teaches students about abstract art in a fun way. Explains that students draw cats, learn about the work of Pablo Picasso, and, in the style of Picasso, combine the parts of the cats (tail, legs, head, body) together in unconventional ways. (CMK)

  10. [Carotid duplex ultrasonography for neurosurgeons].

    PubMed

    Sadahiro, Hirokazu; Ishihara, Hideyuki; Oka, Fumiaki; Suzuki, Michiyasu

    2011-12-01

    Carotid duplex ultrasonography (CDU) is one of the most well-known imaging methods for arteriosclerosis and ischemic stroke. For neurosurgeons, it is very important for the details of carotid plaque to be thoroughly investigated by CDU. Symptomatic carotid plaque is very fragile and easily changes morphologically, and so requires frequent CDU examination. Furthermore, after carotid endarterectomy (CEA) and carotid artery stenting (CAS), restenosis is evaluated with CDU. CDU facilitates not only morphological imaging in the B mode, but also allows a flow study with color Doppler and duplex imaging. So, CDU can help assess the presence of proximal and intracranial artery lesions in spite of only having a cervical view, and the patency of the extracranial artery to intracranial artery bypass is revealed with CDU, which shows a rich velocity and low pulsatility index (PI) in duplex imaging. For the examiner, it is necessary to ponder on what duplex imaging means in examinations, and to summarize all imaging finding.

  11. Cat scratch disease

    MedlinePlus

    ... t scratch and bite. Don't allow a cat to lick your skin, eyes, mouth, or open wounds or scratches. Use flea control measures to lower the risk your cat develops the disease. Don't touch feral cats. ...

  12. Clinical results of carotid artery stenting versus carotid endarterectomy

    PubMed Central

    Akinci, Tuba; Derle, Eda; Kibaroğlu, Seda; Harman, Ali; Kural, Feride; Cınar, Pınar; Kilinc, Munire; Akay, Hakki T.; Can, Ufuk; Benli, Ulku S.

    2016-01-01

    Objective: To review our results of carotid artery stenting (CAS) and carotid endarterectomy (CEA). Methods: We evaluated the medical records of patients undergoing carotid artery revascularization procedure, between 2001 and 2013 in Baskent University Hospital, Ankara, Turkey. Carotid artery stenting or CEA procedures were performed in patients with asymptomatic carotid stenosis (≥70%) or symptomatic stenosis (≥50%). Demographic data, procedural details, and clinical outcomes were recorded. Primary outcome measures were in 30-day stroke/transient ischemic attacks (TIA)/amaurosis fugax or death. Secondary outcome measures were nerve injury, bleeding complications, length of stay in hospital, stroke, restenosis (ICA patency), and all-cause death during long-term follow-up. Results: One hundred ninety-four CEA and 115 CAS procedures were performed for symptomatic and/or asymptomatic carotid artery stenosis. There is no significant differences 30-day mortality and neurologic morbidity between CAS (13%) and CEA procedures (7.7%). Length of stay in hospital were significantly longer in CEA group (p=0.001). In the post-procedural follow up, only in symptomatic patients, restenosis rate was higher in the CEA group (p=.045). The other endpoints did not differ significantly. Conclusions: Endovascular stent treatment of carotid artery atherosclerotic disease is an alternative for vascular surgery, especially for patients that are high risk for standard CEA. The increasing experience, development of cerebral protection systems and new treatment protocols increases CAS feasibility. PMID:27744460

  13. Percutaneous Thrombin Injection with a Distal Embolic Protection Device for Treatment of a Common Carotid Artery Pseudoaneurysm

    PubMed Central

    Lee, J.H.; Tseng, I.K.; Siegel, R.L.; Roychowdhury, S.

    2013-01-01

    Summary Carotid artery pseudoaneurysm is a rare complication from placement of an internal jugular triple lumen catheter. Endovascular stenting is the favored treatment option in the setting of traumatic carotid injury. In other parts of the body, specifically the femoral artery, thrombin injection has become the standard of care. We intend to show that effective management of carotid pseudoaneurysms can also be achieved with thrombin injection after placement of a distal embolic protection device. PMID:23693049

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

    PubMed

    Khandelwal, Priyank; Chaturvedi, Seemant

    2015-09-01

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

  15. [Carotid endarterectomy under local anesthesia].

    PubMed

    Kuz'min, A L; Belov, Iu V

    2001-01-01

    Results of carotid endarterectomy (CEAE) in 193 patients with different degree of cerebrovascular insufficiency were analyzed. All the patients were men with carotid atherosclerosis (age from 39 to 68 years, mean age 53.6 +/- 0.4). A total of 253 CEAEs were performed under local anesthesia (60 patients underwent consecutive bilateral operations). In early postoperative period 3 patients died, one of them--of ischemic stroke due to thrombosis of internal carotid artery on the side of the operation. Non-fatal stroke was in 1 patient. There were no intraoperative cerebral complications. This testifies to reliability of cerebral circulation control through direct contact with patient.

  16. Redistribution by 5-hydroxytryptamine of carotid arterial blood at the expense of arteriovenous anastomotic blood flow

    PubMed Central

    Saxena, Pramod R.; Verdouw, Pieter D.

    1982-01-01

    1. The effects of 5-hydroxytryptamine by intravenous (1, 5 and 10 μg kg-1 min-1 in cats) and intracarotid (0·5 and 2 μg kg-1 min-1 in pigs) routes were studied on the complete distribution of common carotid artery blood flow, measured with radioactive microspheres (15 μm). In addition, the amine was also infused (0·75-3 μg kg-1 min-1) into the carotid artery of cats to observe its influence on the shunting of microspheres in the jugular venous blood. 2. The basal total common carotid blood flow was distributed ipsilaterally mainly to extracerebral tissues and only little blood entered the brain. As shown by the presence of microspheres in the lungs after injection into the carotid artery (52% in cats; 82% in pigs), a major fraction of the carotid blood by-passed the capillary bed through arteriovenous anastomoses in the head (non-nutrient fraction). 3. 5-Hydroxytryptamine redistributed the blood in favour of the nutrient compartment at the expense of arteriovenous anastomotic fraction. In cats, tissue blood flow did not significantly change but, in the pig, blood flow to all tissues, particularly to skin and ears, was substantially increased despite a reduction in total carotid blood flow. This reduction was entirely due to a change in the non-nutrient fraction. 4. Intracarotid infusion of 5-hydroxytryptamine in vagosympathectomized intact or spinal cats decreased the number of microspheres appearing in the jugular venous blood, again indicating a reduction in arteriovenous anastomotic flow due to a constriction of these non-nutrient vessels. 5. Cyproheptadine (1 mg kg-1) completely reversed the effect of 5-hydroxytryptamine on the total carotid blood flow. However, the vasoconstriction of arteriovenous anastomoses was only partially attenuated and the vasodilatatory response was either unchanged (muscle) or even enhanced (skin, ear and bones). 6. It is suggested that 5-hydroxytryptamine causes vasoconstriction of the large arteries via D-receptors which are

  17. Use of absorbable sutures in canine carotid arteries.

    PubMed

    Rey, A R; Carrillo-Farga, J; Velasco, C O; Valencia, M O

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material.

  18. The validity of internal carotid back pressure measurements during carotid endarterectomy for unilateral carotid stenosis.

    PubMed

    Lord, R S; Graham, A R

    1986-06-01

    Peri-operative neurological deficits in 212 patients undergoing carotid endarterectomy for unilateral carotid stenosis were examined to determine whether the internal carotid back pressure (ICBP) correctly predicted the need for a protective shunt during temporary carotid occlusion. Three strokes occurred in 149 patients who were not shunted. In one of these the ICBP indicated the need for a shunt, but shunting was not possible for technical reasons and a stroke due to hypoperfusion occurred. In another patient a stroke occurred as a result of embolism. There was only one patient where the ICBP possibly incorrectly predicted that a shunt would not be necessary. Four strokes due to various causes occurred in the 63 shunted patients. Shunting was not withheld from these patients in order to prove that ICBP would correctly predict their vulnerability to hypoperfusion since to have done so would be unethical. The results indicate that in patients with unilateral carotid stenosis the ICBP is an accurate indicator of which patients can undergo carotid endarterectomy without the need for shunting.

  19. pH regulation in adult rat carotid body glomus cells. Importance of extracellular pH, sodium, and potassium [published erratum appears in J Gen Physiol 1993 Jan;101(1):following 144

    PubMed Central

    1992-01-01

    The course of intracellular pH (pHi) was followed in superfused (36 degrees C) single glomus (type I) cells of the freshly dissociated adult rat carotid body. The cells had been loaded with the pH-sensitive fluorescent dye 2',7'-(2-carboxyethyl)-5 (and -6)-carboxyfluorescein. The high K(+)-nigericin method was used for calibration. The pHi of the glomus cell at pHo 7.40, without CO2, was 7.23 +/- 0.02 (n = 70); in 5% CO2/25 mM HCO3-, pHi was 7.18 +/- 0.08 (n = 9). The pHi was very sensitive to changes in pHo. Without CO2, delta pHi/delta pHo was 0.85 (pHo 6.20-8.00; 32 cells), while in CO2/HCO3- this ratio was 0.82 irrespective of whether pHo (6.80-7.40; 14 cells) was changed at constant PCO2 or at constant [HCO3-]o. The great pHi sensitivity of the glomus cell to pHo is matched only by that of the human red cell. An active Na+/H+ exchanger (apparent Km = 58 +/- 6 mM) is present in glomus cells: Na+ removal or addition of the amiloride derivative 5- (N,N-hexamethylene)-amiloride induced pHi to fall by as much as 0.9. The membrane of these cells also contains a K+/H+ exchanger. Raising [K+]o from 4.7 to 25, 50, or 140 mM reversibly raised pHi by 0.2, 0.3, and 0.6, respectively. Rb+ had no effect, but in corresponding concentrations of Tl+ alkalinization was much faster than in K+. Reducing [K+]o to 1.5 mM lowered pHi by 0.1. These pHi changes were shown not to be due to changes in membrane voltage, and were even more striking in the absence of Na+. Intrinsic buffering power (amount of strong base required to produce, in the nominal absence of CO2, a small pHi rise) increased from 3 to approximately 21 mM as pHi was lowered, but remained nearly unchanged below pHi 6.60. The fitted expression assumed the presence of one "equivalent" intracellular buffer (pK 6.41, 41 mM). The exceptional pHi sensitivity to pHo suggests that the pHi of the glomus cell is a link in the chemoreceptor's response to external acidity. PMID:1294152

  20. 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.

  1. Angioplasty and stent placement - carotid artery - discharge

    MedlinePlus

    ... angioplasty and stenting - discharge; CAS - discharge; Endarterectomy - carotid artery - discharge; Angioplasty - carotid artery - discharge ... were done to open a narrowed or blocked artery that supplies blood to your brain. Your health ...

  2. The Short-Term Effect of Ketogenic Diet on Carotid Intima-Media Thickness and Elastic Properties of the Carotid Artery and the Aorta in Epileptic Children.

    PubMed

    Doksöz, Önder; Güzel, Orkide; Yılmaz, Ünsal; İşgüder, Rana; Çeleğen, Kübra; Meşe, Timur; Uysal, Utku

    2015-10-01

    The aim of this prospective study is to investigate the effect of a 6-month-long ketogenic diet on carotid intima-media thickness, carotid artery, and aortic vascular functions. Thirty-eight drug-resistant epileptic patients who were being treated with ketogenic diet were enrolled. Fasting total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, total cholesterol, and glucose concentrations were measured and echocardiography was performed in all patients before the beginning of ketogenic diet and at the sixth month of treatment. The body weight, height, body mass index, serum levels of triglyceride, total cholesterol, and low-density lipoprotein increased significantly at month 6 when compared to baseline values (P < .05). Carotid intima-media thickness, elastic properties of the aorta, and carotid artery did not change at the sixth month of therapy compared to baseline values. A 6-month-long ketogenic diet has no effect on carotid intima-media thickness and elastic properties of the carotid artery and the aorta.

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

    PubMed Central

    Johansson, Elias P; Wester, Per

    2008-01-01

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

  4. Cat Scratch Disease

    MedlinePlus

    Cat scratch disease (CSD) is an illness caused by the bacterium Bartonella henselae. Almost half of all cats carry the infection ... symptoms of CSD, call your doctor. Centers for Disease Control and Prevention

  5. Cat-Scratch Disease

    MedlinePlus

    ... Patients Infants and Young Children Publications & Materials Announcements Cat-Scratch Disease Recommend on Facebook Tweet Share Compartir ( ... play and learn how to attack prey. How cats and people become infected Kitten playing with a ...

  6. Ototoxicity in dogs and cats.

    PubMed

    Oishi, Naoki; Talaska, Andra E; Schacht, Jochen

    2012-11-01

    A variety of drugs in veterinary use have side effects that can potentially damage the senses of hearing or balance in animals. A large body of literature exists on the incidence and mechanisms of ototoxicity in experimental animals and in humans, but little is documented in domestic dogs and cats. However, the generality of these adverse actions across species allows one to extrapolate and provide the veterinarian with insight into possible complications of chemotherapy.

  7. Cat-Scratch Disease

    MedlinePlus

    ... have diabetes or those who have acquired immunodeficiency syndrome (AIDS).Cat-scratch disease is also called cat-scratch fever. ... You can also get the bacteria in your eyes if you pet a cat that has the bacteria on its fur and ...

  8. CATS Featured Articles

    Atmospheric Science Data Center

    2017-01-31

      CATS Featured Articles       A Slice of Cirrus: Image of ... just hours before by the Cloud-Aerosol Transport System (CATS) onboard the International Space Station. Nighttime View of Raung Volcanic Plume : Natural Hazards  - The CATS instrument slices through darkness to reveal the vertical structure of a ...

  9. Renal morphology in cats with diabetes mellitus.

    PubMed

    Zini, E; Benali, S; Coppola, L; Guscetti, F; Ackermann, M; Lutz, T A; Reusch, C E; Aresu, L

    2014-11-01

    In humans, diabetes mellitus (DM) is an important cause of renal damage, with glomerular lesions being predominant. In cats, although diabetes is a common endocrinopathy, it is yet unknown whether it leads to renal damage. The aim of the study was to compare renal histologic features and parameters of renal function in diabetic cats against a control population matched for age, gender, breed, and body weight. Thirty-two diabetic and 20 control cats were included. Kidney sections from paraffin-embedded kidney samples were stained and examined with optical microscopy to identify glomerular, tubulointerstitial, and vascular lesions and to assess their frequency and severity. Serum creatinine and urea concentrations were also compared. Glomerular lesions were observed in 29 cats overall, with mesangial matrix increase being more common (19 cats). Tubulointerstitial lesions were observed in 42 cats, including lymphocytic infiltration (29), fibrosis (22), or tubular necrosis (21). Vascular lesions were observed in 5 cases. The frequency and severity of histologic lesions did not differ between diabetic and control cats; however, among diabetics, those that survived longer after diagnosis had more glomerular and vascular lesions. Serum creatinine and urea concentrations were similar between groups; in diabetic cats median creatinine was 109 μmol/l (range, 51-1200) and urea was 12 mmol/l (range, 4-63), and in controls creatinine was 126 μmol/l (range, 50-875) and urea 11 mmol/l (range, 3-80). The results suggest that DM in cats does not lead to microscopically detectable kidney lesions or clinically relevant renal dysfunction. The authors hypothesize that the short life expectancy of diabetic cats may be the main reason for the difference from human diabetics.

  10. Selection of treatment for patients with carotid artery disease: medication, carotid endarterectomy, or carotid artery stenting.

    PubMed

    Bosiers, Marc; Peeters, Patrick; Deloose, Koen; Verbist, Jürgen; Sprouse, Richard L

    2005-01-01

    Patients presenting with atherosclerosis of the extracranial carotid arteries may be offered carotid endarterectomy (CEA), carotid artery stenting (CAS), or medical therapy to reduce their risk of stroke. In many cases, the choice between treatment modalities remains controversial. An algorithm based on patients' neurologic symptoms, comorbidities, limiting factors for CAS and CEA, and personal preferences was developed to determine the optimal treatment in each case. This algorithm was then employed to determine therapy in 308 consecutive patients presenting to a single institution during one calendar year. Ninety-five (30.8%) patients presented with an asymptomatic carotid stenosis of more than 80% and 213 (69.2%) with a symptomatic stenosis of more than 50%. According to our algorithm, 59 (62.1%) of the 95 asymptomatic patients received CAS, 20 (21.1%) received CEA, and 16 (16.8%) received medical therapy. All symptomatic patients underwent intervention; 153 (71.8%) were treated with CAS and 60 (28.2%) with CEA. Combined 30-day stroke and death rates after CAS were 1.7% in asymptomatic patients and 2.6% in symptomatic patients. After CEA, these rates were 0% and 3.3%, respectively. Careful selection of treatment modality according to predetermined criteria can result in improved outcomes.

  11. Generation of cloned transgenic cats expressing red fluorescence protein.

    PubMed

    Yin, Xi Jun; Lee, Hyo Sang; Yu, Xian Feng; Choi, Eugene; Koo, Bon Chul; Kwon, Mo Sun; Lee, Young S; Cho, Su Jin; Jin, Guang Zhen; Kim, Lyoung Hyo; Shin, Hyoung Doo; Kim, Teoan; Kim, Nam Hyung; Kong, Il Keun

    2008-03-01

    A method for engineering and producing genetically modified cats is important for generating biomedical models of human diseases. Here we describe the use of somatic cell nuclear transfer to produce cloned transgenic cats that systemically express red fluorescent protein. Immature oocytes were collected from superovulating cat ovaries. Donor fibroblasts were obtained from an ear skin biopsy of a white male Turkish Angora cat, cultured for one to two passages, and subjected to transduction with a retrovirus vector designed to transfer and express the red fluorescent protein (RFP) gene. A total of 176 RFP cloned embryos were transferred into 11 surrogate mothers (mean = 16 +/- 7.5 per recipient). Three surrogate mothers were successfully impregnated (27.3%) and delivered two liveborn and one stillborn kitten at 65 to 66 days of gestation. Analysis of nine feline-specific microsatellite loci confirmed that the cloned cats were genetically identical to the donor cat. Presence of the RFP gene in the transgenic cat genome was confirmed by PCR and Southern blot analyses. Whole-body red fluorescence was detected 60 days after birth in the liveborn transgenic (TG) cat but not in the surrogate mother cat. Red fluorescence was detected in tissue samples, including hair, muscle, brain, heart, liver, kidney, spleen, bronchus, lung, stomach, intestine, tongue, and even excrement of the stillborn TG cat. These results suggest that this nuclear transfer procedure using genetically modified somatic cells could be useful for the efficient production of transgenic cats.

  12. Exocrine Pancreas in Cats With Diabetes Mellitus.

    PubMed

    Zini, E; Ferro, S; Lunardi, F; Zanetti, R; Heller, R S; Coppola, L M; Guscetti, F; Osto, M; Lutz, T A; Cavicchioli, L; Reusch, C E

    2016-01-01

    Pancreatitis has been described in cats with diabetes mellitus, although the number of studies currently available is very limited. In addition, ketoacidosis has been hypothesized to be associated with pancreatitis in diabetic cats. The aims of the present study were to investigate whether diabetic cats have pancreatitis and to determine if pancreatitis is more frequent with ketoacidosis. Samples of pancreas were collected postmortem from 37 diabetic cats, including 15 with ketoacidosis, and 20 control cats matched for age, sex, breed, and body weight. Sections were stained with hematoxylin and eosin, double-labeled for insulin/CD3, insulin/CD20, insulin/myeloperoxidase, insulin/PCNA, and glucagon/Ki67, and single-labeled for Iba1. A previously proposed semiquantitative score was used to characterize pancreatitis, along with counts of inflammatory cells. Scores of pancreatitis and the number of neutrophils, macrophages, and lymphocytes in the exocrine pancreas did not differ between diabetic and control cats or between diabetic cats with and without ketoacidosis. Of note, PCNA-positive acinar cells were increased (P = .002) in diabetic cats, particularly near islets (P < .001). Ki67-positive acinar cells were increased only near islets (P = .038). Ketoacidosis was not linked to proliferation. The results suggest that histopathologic evidence of pancreatitis may not be more frequent in diabetic cats and that ketoacidosis may not be associated with it at the time of death. Augmented PCNA-positive acinar cells might indicate increased proliferation due to chronic pancreatitis. The reason behind the prevalent proliferation of acinar cells surrounding pancreatic islets deserves further investigation.

  13. Cat scratch encephalopathy.

    PubMed

    Silver, B E; Bean, C S

    1991-06-01

    Cat scratch disease is usually benign, self-limited and without sequelae. Margileth has established four clinical criteria, three of which must be satisfied to make the diagnosis: 1) a history of animal exposure, usually kitten, with primary skin or ocular lesions; 2) regional chronic adenopathy without other apparent cause; 3) a positive cat scratch disease antigen skin test; and 4) lymph node biopsy demonstrating noncaseating granulomas and germinal center hyperplasia. Central nervous system involvement in cat scratch disease has been previously reported, although it is extremely uncommon. In a several-month period, we encountered two cases of cat scratch disease complicated by encephalopathy. The intents of this paper are twofold: 1) to briefly review the current literature on cat scratch disease, 2) to demonstrate that cat scratch disease complicated by encephalopathy presents acutely with seizures, posturing and coma and resolves rapidly with supportive care.

  14. Computerised Axial Tomography (CAT)

    DTIC Science & Technology

    1990-06-01

    OF COMPUTERISED AXIAL TOMOGRAPHY Paragraph 1.1 ORIGIN, DEVELOPMENT AND MARKET OF CAT Paragraph 1.2 EQUIPMENT Chapter 2 OPERATIONAL PRINCIPLE OF A CT...DEVELOPMENT OF THE COMPUTERISED AXIAL TOMOGRAPHY 1.1 Origin, development and marketing of the CAT The origin of the CAT goes back to 1961 when...count on wide commercial possibilities, in the international market . In particular, EMI entered, very forcefully, the American market , always

  15. Association between HbA1c and carotid atherosclerosis among elderly Koreans with normal fasting glucose

    PubMed Central

    Lee, Seung Won; Kim, Hyeon Chang; Lee, Yong-ho; Song, Bo Mi; Choi, Hansol; Park, Ji Hye; Rhee, Yumie; Kim, Chang Oh

    2017-01-01

    Aim We examined whether glycated haemoglobin (HbA1c) is associated to carotid atherosclerosis in an elderly Korean population with normal fasting glucose. Methods Using data from the Korean Urban Rural Elderly study, we conducted a cross-sectional analysis of 1,133 participants (335 men and 798 women) with a mean age of 71.8 years. All participants had fasting blood glucose less than 100mg/dL (5.6 mmol/L) and HbA1c level below 6.5% (48 mmol/mol). They were also free from a history of cardiovascular disease, known type 2 diabetes mellitus or use of anti-diabetes medications. Carotid atherosclerosis was assessed by intima-media thickness (IMT) using ultrasonography. The association between HbA1c and carotid IMT was investigated using multivariable linear regression analysis. Results HbA1c levels were independently and positively associated with carotid IMT (β = 0.020, p = 0.045) after adjusting for sex, age, body mass index, systolic blood pressure, diastolic blood pressure, triglyceride, LDL cholesterol, smoking and alcohol intake. However, fasting insulin and glucose levels were not associated with carotid IMT. Conclusion HbA1c levels were positively associated with carotid atherosclerosis, as assessed by carotid IMT, in an elderly population with normoglycemia. Our study suggested that higher HbA1c level is an effective and informative marker of carotid atherosclerosis in an elderly population. PMID:28178313

  16. Carotid baroreceptor reflexes in humans during orthostatic stress.

    PubMed

    Cooper, V L; Hainsworth, R

    2001-09-01

    Orthostatic stress, including standing, head-up tilting and lower body suction, results in increases in peripheral vascular resistance but little or no change in mean arterial pressure. This study was undertaken to determine whether the sensitivity of the carotid baroreceptor reflex was enhanced during conditions of decreased venous return. We studied eight healthy subjects and determined responses of pulse interval (ECG) and forearm vascular resistance (mean finger blood pressure divided by Doppler estimate of brachial artery blood velocity) to graded increases and decreases in carotid transmural pressure, effected by a neck suction/pressure device. Responses were determined with and without the application of lower body negative pressure (LBNP) at -40 mmHg. Stimulus-response curves were determined as the responses to graded neck pressure changes and the differential of this provided estimates of reflex sensitivity. Changes in carotid transmural pressure caused graded changes in R-R interval and vascular resistance. The cardiac responses were unaffected by LBNP. Vascular resistance responses, however, were significantly enhanced during LBNP and the peak gain of the reflex was increased from 1.2 +/- 0.3 (mean +/- S.E.M.) to 2.2 +/- 0.3 units (P < 0.05). The increased baroreflex gain may contribute to maintenance of blood pressure during orthostatic stress and limit the pressure decreases during prolonged periods of such stress.

  17. Cat-scratch Disease.

    PubMed

    Klotz, Stephen A; Ianas, Voichita; Elliott, Sean P

    2011-01-15

    Cat-scratch disease is a common infection that usually presents as tender lymphadenopathy. It should be included in the differential diagnosis of fever of unknown origin and any lymphadenopathy syndrome. Asymptomatic, bacteremic cats with Bartonella henselae in their saliva serve as vectors by biting and clawing the skin. Cat fleas are responsible for horizontal transmission of the disease from cat to cat, and on occasion, arthropod vectors (fleas or ticks) may transmit the disease to humans. Cat-scratch disease is commonly diagnosed in children, but adults can present with it as well. The causative microorganism, B. henselae, is difficult to culture. Diagnosis is most often arrived at by obtaining a history of exposure to cats and a serologic test with high titers (greater than 1:256) of immunoglobulin G antibody to B. henselae. Most cases of cat-scratch disease are self-limited and do not require antibiotic treatment. If an antibiotic is chosen, azithromycin has been shown in one small study to speed recovery. Infrequently, cat-scratch disease may present in a more disseminated form with hepatosplenomegaly or meningoencephalitis, or with bacillary angiomatosis in patients with AIDS.

  18. What Are the Signs and Symptoms of Carotid Artery Disease?

    MedlinePlus

    ... What Are the Signs and Symptoms of Carotid Artery Disease? Carotid artery disease may not cause signs or symptoms until it severely narrows or blocks a carotid artery. Signs and symptoms may include a bruit, a ...

  19. Carotid endarterectomy: current consensus and controversies.

    PubMed

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

    2010-10-01

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

  20. Carotid Stenosis and Ocular Blood Pressure Modelling

    PubMed Central

    Jullian, M.; Kinsner, W.

    1984-01-01

    A model of the human carotid vascular system was developed to study the effects of carotid stenosis on ocular blood pressure and ocular pulse waveform. The model incorporates a non-linear element representing a stenosis. A state variable representation of a reduced model is used in a computer simulation. Results show that carotid stenosis as low as 20% are detectable in the ocular blood pressure waveform.

  1. 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.

  2. Carotid Stump Syndrome: Pathophysiology and Endovascular Treatment Options

    SciTech Connect

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

    2011-02-15

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

  3. Metabolizable energy intake of client-owned adult cats.

    PubMed

    Thes, M; Koeber, N; Fritz, J; Wendel, F; Dobenecker, B; Kienzle, E

    2015-12-01

    A retrospective analysis of the metabolizable energy (ME) intake of privately owned pet cats from the authors' nutrition consultation practice (years 2007-2011) was carried out to test whether current recommendations are suitable for pet cats. Data of 80 adult cats (median age: 9.0 years, median deviation from ideal weight: +22.5%, majority neutered) at maintenance were available. Six percentage of the cats were healthy and the others were affected by various chronic diseases. A standardized questionnaire was used, cat owners weighed cat and food. For ration calculation, the software Diet Check Munich(™) was used (ME prediction according to National Research Council, 2006: Nutrient Requirements of Dogs and Cats. National Academy Press, Washington, DC). Data were analysed for the factors deviation from ideal weight, breed, age, gender, disease and type of feeding [prepared food (dry, wet) vs. home-made]. Over- or underweight were defined as ≥15% deviation from ideal body weight (BW) according to Kienzle and Moik (British Journal of Nutrition 2011, 106, Suppl 1: S113). Cat owner's estimation of ideal BW was higher than literature data from Kienzle and Moik (2011). Based on literature data, 26.3% of the pet cats were normal weight, 63.7% overweight and 10% underweight. The mean ME intake of all adult cats amounted to 0.40 ± 0.14 MJ/kg actual BW(0.67) (n = 80). When the data were analysed according to normal, over- and underweight, there was a significant effect with normal weight cats eating 0.46 MJ/kg BW(0.67) . Underweight cats ate even more (0.49 MJ/kg BW(0.67) ), whereas overweight cats ate considerably less (0.36 MJ/kg BW(0.67) ). The other factors had no influence on ME intake of adult cats.

  4. Dog and cat bites.

    PubMed

    Ellis, Robert; Ellis, Carrie

    2014-08-15

    Animal bites account for 1% of all emergency department visits in the United States and more than $50 million in health care costs per year. Most animal bites are from a dog, usually one known to the victim. Most dog bite victims are children. Bite wounds should be cleaned, copiously irrigated with normal saline using a 20-mL or larger syringe or a 20-gauge catheter attached to the syringe. The wound should be explored for tendon or bone involvement and possible foreign bodies. Wounds may be closed if cosmetically favorable, such as wounds on the face or gaping wounds. Antibiotic prophylaxis should be considered, especially if there is a high risk of infection, such as with cat bites, with puncture wounds, with wounds to the hand, and in persons who are immunosuppressed. Amoxicillin/clavulanate is the first-line prophylactic antibiotic. The need for rabies prophylaxis should be addressed with any animal bite because even domestic animals are often unvaccinated. Postexposure rabies prophylaxis consists of immune globulin at presentation and vaccination on days 0, 3, 7, and 14. Counseling patients and families about animal safety may help decrease animal bites. In most states, physicians are required by law to report animal bites.

  5. Endothelial Function and Carotid Intimal Medial Thickness in Asymptomatic Subjects With and Without Cardiovascular Risk Factors

    PubMed Central

    Ananthakrishna, Rajiv; Shankarappa, Ravindranath K; Rangan, Kapil; Chandrasekaran, Dhanalakshmi; Nanjappa, Manjunath C

    2012-01-01

    Background The study was performed to assess endothelial function and carotid intimal-medial thickness (IMT) in asymptomatic patients, with and without risk factors for cardiovascular disease. Methods A cross sectional survey of asymptomatic patients, aged 21 - 60 years, with and without risk factors for cardiovascular disease was recruited from the outpatient department of Cardiology. Endothelial function was evaluated by flow mediated dilatation (FMD) of the brachial artery and carotid IMT was determined using a high resolution B mode ultrasonography system. Results A total of 104 patients were included in the study. The mean carotid IMT was 0.67 ± 0.05 mm in the group without risk factors and 0.78 ± 0.12 mm in the group with risk factors (P value < 0.05). Endothelial dysfunction (ED) and increased carotid IMT were more significant in the group with risk factors (P value < 0.001). Age, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood pressure, body mass index and HbA1c had a significant correlation with both IMT and FMD response. A higher proportion of subjects with diabetes mellitus (87%), metabolic syndrome (86%) and family history of premature coronary artery disease (78%) had ED. In subjects with normal coronary angiogram, 71% had abnormal FMD response and 36% had increased carotid IMT. Conclusion In asymptomatic subjects, risk factors for cardiovascular disease are significantly associated with objective evidence of ED and increased carotid IMT. FMD response and carotid IMT values are likely to yield additional information beyond traditional risk factors for classifying patients in regard to the likelihood of cardiovascular event. Therapeutic measures with the aim of improving endothelial function and reducing carotid IMT may reduce the burden of cardiovascular disease.

  6. That Fat Cat

    ERIC Educational Resources Information Center

    Lambert, Phyllis Gilchrist

    2012-01-01

    This activity began with a picture book, Nurit Karlin's "Fat Cat On a Mat" (HarperCollins; 1998). The author and her students started their project with a 5-inch circular template for the head of their cats. They reviewed shapes as they drew the head and then added the ears and nose, which were triangles. Details to the face were added when…

  7. State of cat genomics.

    PubMed

    O'Brien, Stephen J; Johnson, Warren; Driscoll, Carlos; Pontius, Joan; Pecon-Slattery, Jill; Menotti-Raymond, Marilyn

    2008-06-01

    Our knowledge of cat family biology was recently expanded to include a genomics perspective with the completion of a draft whole genome sequence of an Abyssinian cat. The utility of the new genome information has been demonstrated by applications ranging from disease gene discovery and comparative genomics to species conservation. Patterns of genomic organization among cats and inbred domestic cat breeds have illuminated our view of domestication, revealing linkage disequilibrium tracks consequent of breed formation, defining chromosome exchanges that punctuated major lineages of mammals and suggesting ancestral continental migration events that led to 37 modern species of Felidae. We review these recent advances here. As the genome resources develop, the cat is poised to make a major contribution to many areas in genetics and biology.

  8. Comparative study of aural microflora in healthy cats, allergic cats and cats with systemic disease.

    PubMed

    Pressanti, Charline; Drouet, Clémence; Cadiergues, Marie-Christine

    2014-12-01

    Twenty healthy cats (group 1) with clinically normal ears, 15 cats with systemic disease (group 2) and 15 allergic cats (group 3) were included in a prospective study. The experimental unit was the ear. A clinical score was established for each ear canal after otoscopic examination. Microbial population was assessed on cytological examination of smears performed with the cotton-tipped applicator smear technique. Fungal population was significantly more prominent in allergic cats (P <0.001) and in diseased cats compared with healthy cats (P <0.02). Bacterial population was significantly higher in allergic cats than in healthy cats (P <0.001) and cats suffering from systemic disease (P <0.001). Bacterial overgrowth was also higher in cats with systemic disease than healthy cats. In cats from group 2, only fungal overgrowth was associated with otitis severity. In group 3, only bacterial overgrowth was associated with otitis severity.

  9. Relationship between carotid intima‐media thickness and arterial stiffness in children after Kawasaki disease

    PubMed Central

    Cheung, Y‐f; Wong, S J; Ho, M H K

    2007-01-01

    Background Evidence of premature atherosclerosis and systemic arterial stiffening in patients after Kawasaki disease is accumulating. Aim To test the hypothesis that carotid intima‐media thickness (IMT), a surrogate marker of atherosclerosis, is associated with systemic arterial stiffness in children after Kawasaki disease. Methods A cohort of 72 patients was studied, comprising 26 patients with Kawasaki disease and coronary aneurysms (group I), 24 patients with Kawasaki disease and normal coronary arteries (group II) and 22 healthy age‐matched children (group III). The carotid IMT, carotid artery stiffness index, brachioradial pulse wave velocity (PWV), fasting total cholesterol, high‐density lipoprotein (HDL) cholesterol and low‐density lipoprotein (LDL) cholesterol were determined and compared among the three groups. Results The carotid IMT was related to indices of arterial stiffness, and significant determinants of carotid IMT were identified by multivariate analysis. The mean (standard deviation (SD)) carotid IMT of both group I (0.41 (0.04) mm) and group II (0.39 (0.04) mm) was significantly greater than that of group III (0.36 (0.04) mm; p<0.001 and p = 0.008, respectively). For the entire cohort, carotid IMT correlated positively with LDL cholesterol (r = 0.31, p = 0.009), carotid artery stiffness index (r = 0.40, p = 0.001) and brachioradial PWV (r = 0.28, p = 0.016), but not with age, body mass index, systemic blood pressure, and HDL and total cholesterol. Multiple linear regression analysis identified carotid artery stiffness index (β = 0.25, p = 0.028) and subject grouping (β = −0.39, p = 0.001; model R2 = 0.29) as significant correlates of carotid IMT. Conclusion The increased carotid IMT in children after Kawasaki disease is associated with systemic arterial stiffening. PMID:16820386

  10. Ischemic stroke risk reduction following cardiac surgery by carotid compression

    NASA Astrophysics Data System (ADS)

    Isingoma, Paul

    Every year over 500,000 cardiovascular procedures requiring cardiopulmonary bypass (CPB) are performed in the United States. CPB is a technique that temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. During CPB, an aortic cross-clamp is used to clamp the aorta and separate the systemic circulation from the outflow of the heart. Unfortunately, these procedures have been found to cause most cerebral emboli, which produce clinical, subclinical and silent neurologic injuries. Many clinical neurologic injuries occur in the postoperative period, with over 20% of the clinical strokes occurring during this period. In this study, we focus on visualizing the flow distribution in the aortic arch, the effect of carotid compression and the influence of compression time and MAP during CPB on reducing cerebral emboli. Experiments are performed with an aortic arch model in a mock cardiovascular system. Fluorescent particles are used to simulate emboli that are released into circulation immediately after carotid compression. The LVAD is used as the pump to produce flow in the system by gradually adjusting the speed to maintain desired clinical conditions. Aortic and proximal branches MAP of 65.0 +/- 5.0 mmHg (normal MAP) or 95.0 +/- 5.0 mmHg (high MAP), aortic flow of 4.0 +/- 0.5 L/min, and all branches flow (left and right carotids, and subclavian arteries) of 10% of the aortic flow. Flow distribution of particles is visualized using LaVision's DaVis imaging software and analyzed using imagej's particle analysis tool to track, count, and record particle properties from the aortic arch. Carotid compression for 10-20 seconds reduces the number of particles entering the carotid arteries by over 73% at normal MAP, and by over 85% at high MAP. A higher MAP resulted in fewer particles entering the branching vessels both at baseline and during occlusion conditions. A compression duration of

  11. The contralateral carotid disease in patients with internal carotid artery occlusion.

    PubMed

    Lovrencić-Huzjan, Arijana; Strineka, Maja; Aiman, Drazen; Strbe, Sanja; Sodec-Simicević, Darja; Demarin, Vida

    2009-09-01

    The one-year incidence of carotid occlusion is 6/100 000 inhabitants in general population. Stroke incidence and mortality rate in these patients vary. Patients that underwent carotid endarterectomy (CES) are at a higher risk of progression of contralateral carotid stenosis. The aim of the study was to investigate the management and natural history of the contralateral internal carotid artery disease in patients with internal carotid artery occlusion (ICAO). During one year, 297 patients with ICAO were investigated. Follow up examinations were retrospectively analyzed and patients were divided into groups according to contralateral carotid disease. Out of 297 patients, only one investigation was performed in 90 patients with carotid occlusion. Thirty three patients were followed up due to postoperative ICAO. In 14 patients, ICAO developed during ultrasonographic follow up. In this group of patients, 9 had unchanged contralateral findings, whereas in 5 patients disease progression was observed. Out of 44 patients with ICAO and contralateral subtotal stenosis at initial investigation, 42 underwent carotid surgery. Postoperatively, 32 patients had normal findings, 6 developed mild carotid stenosis, 2 developed moderate carotid stenosis, and 2 had postoperative carotid occlusion. Two patients were followed-up without intervention. Nine patients with bilateral ICAO were followed-up for years. Follow up was continued in 106 patients with ICAO and contralateral mild to moderate changes. The finding was unchanged in 68 patients. In 21 (30%) patients the disease progressed to subtotal stenosis and 18 patients underwent carotid surgery. Accordingly, contralateral carotid disease progression was observed in one third of patients with carotid occlusion. Additional studies on the issue are needed.

  12. Effects of Hydrazine on Electrophysiology, Behavior and Runway Performance in the Cat.

    DTIC Science & Technology

    HYDRAZINES, *ROCKET PROPELLANTS, ELECTROENCEPHALOGRAPHY, TOXICITY, BEHAVIOR, PERFORMANCE(HUMAN), CENTRAL NERVOUS SYSTEM, TOXIC TOLERANCES, PERMISSIBLE DOSAGE, BODY WEIGHT, ELECTROPHYSIOLOGY, BRAIN , CATS, EXPERIMENTAL DATA.

  13. Use of Absorbable Sutures in Canine Carotid Arteries

    PubMed Central

    Rey, Alejandro R.; Carrillo-Farga, Joaquin; Velasco, Carlos O.; Valencia, Martin O.V.

    1990-01-01

    To study the functional and microstructural characteristics of polydioxanone sutures in vascular surgery, we created 48 vascular anastomoses in the right and left common carotid arteries of 24 mongrel dogs. In each animal, polydioxanone sutures were used in 1 carotid artery, and polypropylene sutures were used in the contralateral carotid artery. Twelve groups of 2 animals each were then formed. The 1st group was observed for 1 month, the 2nd for 2 months, the 3rd for 3 months, and so on until the 12th group, which was observed for 12 months. At the end of each observation period, reoperation was undertaken to evaluate the vascular anastomoses by means of angiography and microscopy. The polypropylene anastomoses showed a marked deformity, with tissue retraction and a foreign body reaction. In contrast, the polydioxanone anastomoses exhibited satisfactory healing, without deformity, and were well tolerated histologically. We believe that polydioxanone may be a useful, alternative vascular suture material. (Texas Heart Institute Journal 1990;17:99-102) Images PMID:15227391

  14. Parasitic infections of domestic cats, Felis catus, in western Hungary.

    PubMed

    Capári, B; Hamel, D; Visser, M; Winter, R; Pfister, K; Rehbein, S

    2013-02-18

    During 2011, faeces from 235 owned domestic cats from a rural area in western Hungary were examined using standard coproscopical techniques. The overall prevalence of cats with endoparasites was 39.6% (95% CI 33.3-46.1). The most frequently identified faecal forms were those of ascarids (Toxocara, 17.4%; Toxascaris 7.2%), followed by those of Aelurostrongylus lungworms (14.5%), hookworms (11.1%), taeniid cestodes (4.7%), Cystoisospora coccidians (4.3%), and capillarids (3.8%). Single and multiple infections with up to five parasites concurrently were founded in 24.7% and 14.9% of the cats, respectively. Mixed endoparasite infections were recorded more frequently (p=0.0245) in cats greater than one year old compared to younger cats. Young cats (≤ 1 year) were parasitized more frequently (p<0.05) with ascarids and Cystoisospora spp. but demonstrated infections of hookworms, lungworms and taeniid cestodes less often than the older cats. Cats with taeniid infection were more likely (p<0.05) to harbour Toxocara, hookworm, Aelurostrongylus, and capillarid infections than cats without taeniid cestodes. Cats of owners who claimed the use of wormers were less frequently helminth-positive compared to cats whose owners did not use anthelmintics (21.2% vs. 44.4%; p=0.001). A subset of 115 faecal samples screened by a coproantigen ELISA revealed Giardia-specific antigen in 37.4% samples. Giardia cysts were found by immunofluorescent staining in 30 of the 43 samples tested positive for Giardia by ELISA. In addition, ectoparasites collected from 82 cats by body search and combing were identified. Fleas (1-30 per cat), biting lice (Felicola subrostratus), and ticks (1-5 per cat) were isolated from 58, 1 and 43 cats, respectively. Ctenocephalides felis was identified on all flea infested cats while single specimens of C. canis and Pulex irritans were recovered from three and two cats, respectively. All but one tick collected were adult Ixodes ricinus; the single other tick was a

  15. Carotid Vascular Abnormalities in Primary Hyperparathyroidism

    PubMed Central

    Walker, M. D.; Fleischer, J.; Rundek, T.; McMahon, D. J.; Homma, S.; Sacco, R.; Silverberg, S. J.

    2009-01-01

    Context: Data on the presence, extent, and reversibility of cardiovascular disease in primary hyperparathyroidism (PHPT) are conflicting. Objective: This study evaluated carotid structure and function in PHPT patients compared with population-based controls. Design: This is a case-control study. Setting: The study was conducted in a university hospital metabolic bone disease unit. Participants: Forty-nine men and women with PHPT and 991 controls without PHPT were studied. Outcome Measures: We measured carotid intima-media thickness (IMT), carotid plaque presence and thickness, and carotid stiffness, strain, and distensibility. Results: IMT, carotid plaque thickness, carotid stiffness, and distensibility were abnormal in PHPT patients, and IMT was higher in patients than controls (0.959 vs. 0.907 mm, P < 0.0001). In PHPT, PTH levels, but not calcium concentration, predicted carotid stiffness (P = 0.04), strain (P = 0.06), and distensibility (P = 0.07). Patients with increased carotid stiffness had significantly higher PTH levels than did those with normal stiffness (141 ± 48 vs. 94.9 ± 44 pg/ml, P = 0.002), and odds of abnormal stiffness increased 1.91 (confidence interval = 1.09–3.35; P = 0.024) for every 10 pg/ml increase in PTH, adjusted for age, creatinine, and albumin-corrected calcium. Conclusions: Mild PHPT is associated with subclinical carotid vascular manifestations. IMT, a predictor of cardiovascular outcomes, is increased. Measures of carotid stiffness are associated with extent of PTH elevation, suggesting that those with more severe PHPT may have impaired vascular compliance and that PTH, rather than calcium, is the mediator. PMID:19755478

  16. Giardia infection in cats.

    PubMed

    Janeczko, Stephanie; Griffin, Brenda

    2010-08-01

    The protozoon Giardia duodenalis is a common gastrointestinal parasite of cats. While most Giardia-infected cats are asymptomatic, acute small bowel diarrhea, occasionally with concomitant weight loss, may occur. Giardia poses a diagnostic challenge, but newer tests, including a commercially available ELISA kit, have improved clinicians' ability to obtain an accurate diagnosis. Several treatment options have been reported, and although none has been shown to be universally effective, most cases can be successfully managed with drug therapy, supportive measures, and environmental control. Current recommendations suggest that combination therapy with fenbendazole and metronidazole may be the safest, most effective treatment option for symptomatic cats.

  17. Carbonic anhydrase and control of breathing: different effects of benzolamide and methazolamide in the anaesthetized cat.

    PubMed Central

    Teppema, L; Berkenbosch, A; DeGoede, J; Olievier, C

    1995-01-01

    1. The effect of inhibition of erythrocyte carbonic anhydrase on the ventilatory response to CO2 was studied by administering benzolamide (70 mg kg-1, i.v.), an inhibitor which does not cross the blood-brain barrier, to carotid body denervated cats which were anaesthetized with chloralose-urethane. 2. In the same animals the effect on the ventilatory response to CO2 of subsequent inhibition of central nervous system (CNS) carbonic anhydrase was studied by infusing methazolamide (20 mg kg-1), an inhibitor which rapidly penetrates into brain tissue. 3. The results show that inhibition of erythrocyte carbonic anhydrase by benzolamide leads to a decrease in the slope of the normoxic CO2 response curve, and a decrease of the extrapolated arterial PCO2 at zero ventilation. 4. Inhibition of CNS carbonic anhydrase by methazolamide results in an increase in slope and alpha-intercept of the ventilatory CO2 response curve. 5. Using a mass balance equation for CO2 of a brain compartment, it is argued that inhibition of erythrocyte carbonic anhydrase results in a decrease in slope of the in vivo CO2 dissociation curve, which can explain the effects of benzolamide. 6. The changes in slope and intercept induced by methazolamide are discussed in relation to effects on neurones containing carbonic anhydrase, which may include central chemoreceptors. PMID:8576866

  18. [Treatment of carotid cavernous fistulas].

    PubMed

    Solymosi, L

    2004-11-01

    The diagnosis and treatment of carotid cavernous fistulas (CCF) is an interdisciplinary challenge for both ophthalmologists and interventional neuroradiologists. According to the clinical signs and symptoms the tentative diagnosis is made by the ophthalmologist. It is the task of the neuroradiologist to ascertain this diagnosis by intra-arterial angiography. If a fistula is suspected this invasive diagnostic procedure is indispensable, not only to establish the diagnosis but also to classify those types of fistula with an unfavourable spontaneous course possibly resulting in intracranial haemorrhage. The indication for therapy is based on the clinical symptoms and the angiographic findings. In a number of cases no therapy is required. Since a fistula may change over time, these patients have to be under close ophthalmological surveillance. In many patients a conservative therapeutic approach with manual compression of the carotid artery is sufficient as a fIrst step. Invasive treatment is performed via the endovascular approach in almost all cases. Direct CCF are predominantly treated transarterially with detachable balloons and/or coils. Recently, intracranial stents have been used increasingly. The embolisation of indirect CCF is most effective using the transvenous access with coils. There are several approaches to the cavernous sinus. The interventional occlusion of CCF is nowadays a very effective treatment associated with a comparatively high cure rate and low incidence of complications. By close cooperation between ophthalmologists and neuroradiologists the patients can be protected against visual loss, the development of a secondary glaucoma, and, most importantly, against intracranial haemorrhage.

  19. Cat tongue Velcro

    NASA Astrophysics Data System (ADS)

    Noel, Alexis; Martinez, Andrea; Jung, Hyewon; Tsai, Ting-Wen; Hu, David

    2016-11-01

    A cat's tongue is covered in an array of spines called papillae. These spines are thought to be used in grooming and rasping meat from bones of prey, although no mechanism has been given. We use high-speed video to film a cat removing cat food deeply wedged into a 3-D printed fur mat. We show that the spines on the tongue act as Velcro for particles. The tongue itself is highly elastic. As the cat presses it against a substrate, the tongue flattens and the spines separate. When the tongue is removed from the substrate the spines come together, wedging particles between them. This elasticity-driven entrapment permits the surface of the tongue to act as a carrier for hard to reach particles, and to increase the efficacy of grooming and feeding.

  20. Carotid Baroreflex Function During Prolonged Exercise

    NASA Technical Reports Server (NTRS)

    Raven, P. B.

    1999-01-01

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

  1. Fatal big cat attacks.

    PubMed

    Cohle, S D; Harlan, C W; Harlan, G

    1990-09-01

    Two cases of fatal attacks by large cats are presented. In the first case, a 30-year-old female zoo worker was attacked by a jaguar that had escaped its cage. In the second case, a 2-year-old girl was fatally injured by her father's pet leopard. The pattern of injuries in these cases is nearly identical to those of these cats' prey in the wild.

  2. Management of Bilateral Carotid Occlusive Disease

    PubMed Central

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

    2016-01-01

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

  3. [The effect of carotid endarterectomy on cognitive disturbances in patients with atherosclerotic stenosis of carotid arteries].

    PubMed

    Iakhno, N N; Fedorova, T S; Damulin, I V; Shcherbiuk, A N; Vinogradov, O A; Lavrent'ev, A V

    2011-01-01

    Clinical and neuropsychological features of non-dementia cognitive disturbances were studied in 102 patients with atherosclerotic carotid stenosis. Cognitive disturbances were assessed after the carotid endarterectomy (CEAE). Mild cognitive impairment was found in 37 (36,3%) of patients, moderate cognitive impairment was diagnosed in 36 (35,3%)patients. Moderate cognitive impairment was found more often in patients with symptomatic carotid stenosis with structural brain changes confirmed by neuroimaging data and with instable atherosclerotic plaques with the predomination of hypodensity component. It allows to suggest that both the reduction of perfusion and arterio-arterial microemboli may cause cognitive dysfunction in patients with atherosclerotic carotid stenosis. The data on the positive effect of CEAE on cognitive functions have been obtained. The positive changes were more distinct in patients with asymptomatic course of carotid stenosis. However CEAE may have a negative effect on cognitive functions in patients with moderate cognitive impairment of dysmnestic character and symptomatic carotid stenosis.

  4. Parotid or carotid? Misled by site.

    PubMed

    Tyagi, Ruchita; Munjal, Manish; Kaur, Pavneet; Kaur, Harpreet; Sood, Neena

    2017-03-06

    We present an interesting scenario where a 64 years old male presented with a long standing painless, infra-auricular swelling, which had progressively increased in size. Based on the site, the clinical impression was of a salivary gland lesion and FNAC was performed. The smears were unusually cellular and had necrotic background. The cytological diagnosis was a cystic neoplasm of salivary gland, possibly mucoepidermoid carcinoma. Warthin's tumor was also kept in differential. However, the radiological investigations, which were made available after the FNAC report were conflicting with cytological diagnosis of a malignancy and were characteristic of a carotid body tumor, generally a benign neoplasm. Surgical excision of the tumor with regional lymph node sampling was done and histopathological examination solved the puzzle by revealing metastasis of paraganglioma to right posterior triangle lymph nodes. This case is unique because of the unusual presentation of a malignant paraganglioma as an infra-auricular swelling, which was clinically considered as a parotid tumor. The clinician as well as the pathologist need to be aware of such diagnostic pitfall. Diagn. Cytopathol. 2017. © 2017 Wiley Periodicals, Inc.

  5. Carotid sheath abscess caused by a tooth decay infection on the opposite side.

    PubMed

    Tuncturk, F Ruya; Uzun, Lokman; Kalcioglu, M Tayyar; Egilmez, Oguz Kadir; Timurlenk, Emine; Erguven, Muferet

    2015-01-01

    Deep neck infections are mortal diseases that need emergency treatment. It can occur at any age but usually in pediatric ages. In this report, a left cervical carotid space abscess of a pediatric patient was discussed. It was interesting that the only origin of the left carotid sheath abscess was right inferior first molar tooth decay. Right neck spaces were all clean. Patient had no immunosupression and also there were no congenital masses such as branchial cleft cysts, foreign bodies, or masses suspicious for malignancies in cervical ultrasound and MRI. We discussed this rare condition under the light of the literature.

  6. Flow diversion in the treatment of carotid injury and carotid-cavernous fistula after transsphenoidal surgery

    PubMed Central

    Lum, Cheemum; Ahmed, Muhammad E; Glikstein, Rafael; dos Santos, Marlise P; Lesiuk, Howard; Labib, Mohamed; Kassam, Amin B

    2015-01-01

    We describe a case of iatrogenic carotid injury with secondary carotid-cavernous fistula (CCF) treated with a silk flow diverter stent placed within the injured internal carotid artery and coils placed within the cavernous sinus. Flow diverters may offer a simple and potentially safe vessel-sparing option in this rare complication of transsphenoidal surgery. The management options are discussed and the relevant literature is reviewed. PMID:26015526

  7. Reference values of one-point carotid stiffness parameters determined by carotid echo-tracking and brachial pulse pressure in a large population of healthy subjects.

    PubMed

    Vriz, Olga; Aboyans, Victor; Minisini, Rosalba; Magne, Julien; Bertin, Nicole; Pirisi, Mario; Bossone, Eduardo

    2017-03-02

    Arterial stiffness can predict cardiovascular events, and the aim of this study was to produce age- and sex-specific reference values for echo-tracking carotid stiffness in healthy subjects. A total of 900 subjects (500 males, mean age 45.8±19 years) were enrolled. Common carotid artery stiffness and compliance, using a high-definition echo-tracking ultrasound system, were evaluated. To compare stiffness parameters across the different age groups, individual scores were transformed into T-scores, indicating how many standard deviation (s.d.) units an individual's score was above or below the mean that was observed in the group including same-sex individuals aged 36 to 44 years. Carotid stiffness was similar among genders, except compliance, which was lower in women (P<0.0001). These characteristics were also maintained when the studied population was divided into seven age groups. Stiffness parameters increased significantly with age, but the opposite occurred for compliance. The T-score was found to increase significantly across all age groups, with a steeper increase in stiffness around the age of 60 years in women. For each T-score s.d., the corresponding carotid absolute values for arterial stiffness and compliance were obtained. In a multivariate model, carotid stiffness parameters were constantly and independently associated with age, mean arterial pressure, pulse pressure, heart rate and body mass index. Our study provides a normogram of carotid arterial stiffness and compliance indices obtained with the echo-tracking method in a large population of healthy subjects stratified by gender and age that can be used in clinical practice.Hypertension Research advance online publication, 2 March 2017; doi:10.1038/hr.2017.24.

  8. Modeling the Carotid Sinus Baroreceptor

    PubMed Central

    Srinivasan, Ramachandra; Nudelman, Harvey B.

    1972-01-01

    A mathematical model that describes the relationship between sinus pressure and nerve discharge frequency of the carotid sinus baroreceptor is presented. It is partly based upon the single-fiber data obtained by Clarke from the sinus nerve of a dog. The model takes into account what is currently known about the physiology of the baroreceptor. It consists of two nonlinear ordinary differential equations and eight free parameters. With one set of values for these eight parameters, the model reproduces well the experimental results reported by Clarke for positive ramp pressure inputs. Only three parameters needed to be adjusted in order to fit the dynamic data. The remaining five were obtained from static and steady-state data. PMID:5056961

  9. 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

  10. Effect of carotid occlusion and of perfusion pressure on renal function in conscious dogs.

    PubMed

    Gross, R; Kirchheim, H; Ruffmann, K

    1981-06-01

    We studied the effect of bilateral common carotid occlusion (implanted pneumatic cuffs) on renal blood flow (electromagnetic flowmeter) and renal function (implanted ureteral catheter) in nine chronically instrumented, conscious dogs on a high sodium diet (14 mmol/kg body weight per day). By means of suprarenal aortic constriction (pneumatic cuff) the influence of renal perfusion pressure was investigated. There was no change in renal blood flow or glomerular filtration rate (inulin clearance) with either reflexly increasing (+49.6%) or constant renal perfusion pressure. Carotid occlusion caused an increase of urine output by 80.5% and of sodium excretion by 85.3% due to a fall in fractional sodium reabsorption (-0.9%) when renal perfusion pressure was allowed to rise. Neither an increase of diuresis or sodium excretion nor an antinatriuresis was observed when renal perfusion pressure was kept constant during carotid occlusion. We conclude that, in conscious dogs at rest, the moderate sympathetic activation associated with carotid occlusion is too small to induce renal sympathetic vasoconstriction or antinatriuresis. The "carotid sinus polyuria" is a pressure-diuresis.

  11. Influence of chronic exercise on carotid atherosclerosis in marathon runners

    PubMed Central

    Taylor, Beth A; Zaleski, Amanda L; Capizzi, Jeffrey A; Ballard, Kevin D; Troyanos, Christopher; Baggish, Aaron L; D'Hemecourt, Pierre A; Dada, Marcin R; Thompson, Paul D

    2014-01-01

    Objectives The effect of habitual, high-intensity exercise training on the progression of atherosclerosis is unclear. We assessed indices of vascular health (central systolic blood pressure (SBP) and arterial stiffness as well as carotid intima-medial thickness (cIMT)) in addition to cardiovascular risk factors of trained runners versus their untrained spouses or partners to evaluate the impact of exercise on the development of carotid atherosclerosis. Setting field study at Boston Marathon. Participants 42 qualifiers (mean age±SD: 46±13 years, 21 women) for the 2012 Boston Marathon and their sedentary domestic controls (46±12 years, n=21 women). Outcomes We measured medical and running history, vital signs, anthropometrics, blood lipids, C reactive protein (CRP), 10 years Framingham risk, central arterial stiffness and SBP and cIMT. Results Multiple cardiovascular risk factors, including CRP, non-high-density lipoprotein cholesterol, triglycerides, heart rate, body weight and body mass index (all p<0.05), were reduced in the runners. The left and right cIMT, as well as central SBP, were not different between the two groups (all p>0.31) and were associated with age (all r≥0.41; p<0.01) and Framingham risk score (all r≥0.44; p<0.01) independent of exercise group (all p>0.08 for interactions). The amplification of the central pressure waveform (augmentation pressure at heart rate 75 bpm) was also not different between the two groups (p=0.07) but was related to age (p<0.01) and group (p=0.02) in a multiple linear regression model. Conclusions Habitual endurance exercise improves the cardiovascular risk profile, but does not reduce the magnitude of carotid atherosclerosis associated with age and cardiovascular risk factors. PMID:24531453

  12. Questions and Answers about Carotid Endarterectomy

    MedlinePlus

    ... other material inside the artery walls is called atherosclerosis, popularly known as "hardening of the arteries." The ... more informed decisions. In another trial (Asymptomatic Carotid Atherosclerosis Study, or ACAS), the procedure has also been ...

  13. Evaluation of Carotid Plaque Using Ultrasound Imaging

    PubMed Central

    2016-01-01

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

  14. Ophthalmic masquerades of the atherosclerotic carotids

    PubMed Central

    Arthur, Anupriya; Alexander, Anika; Bal, Simerpreet; Sivadasan, Ajith; Aaron, Sanjith

    2014-01-01

    Patients with carotid atherosclerosis can present with ophthalmic symptoms. These symptoms and signs can be due to retinal emboli, hypoperfusion of the retina and choroid, opening up of collateral channels, or chronic hypoperfusion of the globe (ocular ischemic syndrome). These pathological mechanisms can produce many interesting signs and a careful history can bring out important past symptoms pointing toward the carotid as the source of the patient's presenting symptom. Such patients are at high risk for an ischemic stroke, especially in the subsequent few days following their first acute symptom. It is important for clinicians to be familiar with these ophthalmic symptoms and signs caused by carotid atherosclerosis for making an early diagnosis and to take appropriate measures to prevent a stroke. This review elaborates the clinical features, importance, and implications of various ophthalmic symptoms and signs resulting from atherosclerotic carotid artery disease. PMID:24817748

  15. Cats protecting birds revisited.

    PubMed

    Fan, Meng; Kuang, Yang; Feng, Zhilan

    2005-09-01

    In this paper, we revisit the dynamical interaction among prey (bird), mesopredator (rat), and superpredator (cat) discussed in [Courchamp, F., Langlais, M., Sugihara, G., 1999. Cats protecting birds: modelling the mesopredator release effect. Journal of Animal Ecology 68, 282-292]. First, we develop a prey-mesopredator-superpredator (i.e., bird-rat-cat, briefly, BRC) model, where the predator's functional responses are derived based on the classical Holling's time budget arguments. Our BRC model overcomes several model construction problems in Courchamp et al. (1999), and admits richer, reasonable and realistic dynamics. We explore the possible control strategies to save or restore the bird by controlling or eliminating the rat or the cat when the bird is endangered. We establish the existence of two types of mesopredator release phenomena: severe mesopredator release, where once superpredators are suppressed, a burst of mesopredators follows which leads their shared prey to extinction; and mild mesopredator release, where the mesopredator release could assert more negative impact on the endemic prey but does not lead the endemic prey to extinction. A sharp sufficient criterion is established for the occurrence of severe mesopredator release. We also show that, in a prey-mesopredator-superpredator trophic food web, eradication of introduced superpredators such as feral domestic cats in the BRC model, is not always the best solution to protect endemic insular prey. The presence of a superpredator may have a beneficial effect in such systems.

  16. The Feline Mystique: Dispelling the Myth of the Independent Cat.

    ERIC Educational Resources Information Center

    Soltow, Willow

    1984-01-01

    Describes learning activities about cats for primary and intermediate grades. Primary grade activity subjects include cat behavior, needs, breeds, storybook cats, and celestial cats. Intermediate grade activity subjects include cat history, care, language, literary cats, and cats in art. (BC)

  17. The effect of activation of central adrenergic receptors by clonidine on the excitability of the solitary tract neurons in cats.

    PubMed

    Lipski, J; Solnicka, E

    1976-01-01

    The effect of i.v. administered clonidine (10-15 mug/kg) on the evoked potential recorded in the dosal part of medulla oblongata, during carotid sinus nerve stimulation, was studied in chloralose-urethane anaesthetized cats. Clonidine influenced the amplitude and configuration of the evoked potential and the changes were parallel to the blood pressure depressor response. However, the blood pressure drops, evoked by i.v. infusion of papaverine, did not influence the potential. It is concluded that the synaptic transmission from the carotid sinus nerve to the second order neurons in the solatary tract area can be modulated by the clonidine-induced activation of central adrenergic receptors.

  18. Carotid sheath haematoma: a case report.

    PubMed

    Yadav, Jayanthi; Badkur, D S; Arora, Arneet

    2009-10-01

    Carotid sheath haematoma is a rare finding, sometimes the only injury found in cases of manual strangulation without any associated external or internal injury to the neck. One such rare case is reported in an 8 year old female victim where presence of carotid sheath haematoma not only helped to ascertain the cause of death but also helped in the reconstruction of mechanism of infliction of force on the neck.

  19. Should Dogs and Cats be Given as Gifts?

    PubMed Central

    Weiss, Emily; Dolan, Emily D.; Garrison, Laurie; Hong, Julie; Slater, Margaret

    2013-01-01

    Simple Summary Policies that state pets should not be adopted as gifts are prevalent at animal welfare organizations, despite the fact that this belief is unfounded. Denying adopters who intend to give the animals as gifts may unnecessarily impede the overarching goal of increasing adoptions of pets from our nations’ shelter system. We found that receiving a dog or cat as a gift was not associated with impact on self-perceived love/attachment, or whether the dog or cat was still in the home. These results suggest there is no increased risk of relinquishment for dogs and cats received as a gift. Abstract Policies that state dogs and cats should not be adopted as gifts are prevalent at animal welfare organizations, despite the fact that this belief is unfounded. Denying adopters who intend to give the animals as gifts may unnecessarily impede the overarching goal of increasing the rate of live-releases of dogs and cats from our nations’ shelter system. The results of this brief survey show that receiving a dog or cat as a gift was neither significantly associated with impact on self-perceived love/attachment, nor was it associated with whether or not respondents still had the dog or cat in the home. The results from this survey add to a growing body of literature that suggests there is no increased risk of relinquishment for dogs and cats received as a gift. PMID:26479748

  20. Presumptive sialadenosis in a cat.

    PubMed

    Boydell, P; Pike, R; Crossley, D

    2000-12-01

    A cat was presented with signs associated with enlargement of the mandibular salivary glands. Histological findings were normal, consistent with a diagnosis of sialadenosis, and the cat responded to symptomatic treatment with oral phenobarbitone.

  1. Internal carotid artery rupture caused by carotid shunt insertion

    PubMed Central

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

    2015-01-01

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

  2. What's inside your cat's head? A review of cat (Felis silvestris catus) cognition research past, present and future.

    PubMed

    Vitale Shreve, Kristyn R; Udell, Monique A R

    2015-11-01

    The domestic cat (Felis silvestris catus) has shared an intertwined existence with humans for thousands of years, living on our city streets and in our homes. Yet, little scientific research has focused on the cognition of the domestic cat, especially in comparison with human's other companion, the domestic dog (Canis lupus familiaris). This review surveys the current status of several areas of cat cognition research including perception, object permanence, memory, physical causality, quantity and time discrimination, cats' sensitivity to human cues, vocal recognition and communication, attachment bonds, personality, and cognitive health. Although interest in cat cognition is growing, we still have a long way to go until we have an inclusive body of research on the subject. Therefore, this review also identifies areas where future research must be conducted. In addition to the scientific value of future work in this area, future research on cat cognition could have an important influence on the management and welfare of pet and free-roaming cats, leading to improved human-cat interactions.

  3. Slipped capital femoral epiphysis in 17 Maine Coon cats.

    PubMed

    Borak, Danilo; Wunderlin, Nadja; Brückner, Michael; Schwarz, Günter; Klang, Andrea

    2017-01-01

    Objectives From May 2009 to January 2015, 208 Maine Coon cats presented to the Tierklinik Hollabrunn - a small animal referral and first-opinion centre - and 17 (8.17%) cats were diagnosed with a slipped capital femoral epiphysis (SCFE). Over the same time period, 29 (0.67%) of 4348 cats (all breeds) were diagnosed with SCFE. Methods Clinical and orthopaedic examinations and diagnostic imaging were performed on all affected Maine Coons. Age at first presentation, sex, body weight, body condition score (BCS), unilateral or bilateral manifestation of the disease, activity level and duration of lameness, age at neutering and known family history of disease were recorded. Sixteen of 17 Maine Coons were surgically treated. Surgically removed femoral tissue samples were histologically examined in 13 cases. Results The mean age at first presentation was 21.47 months; male to female ratio was 16:1; mean body weight was 7.5 kg (range 5.3-9.3 kg); and mean BCS was 5.06/9.0. Seven cats were bilaterally affected; the median duration of decreased activity level and lameness was 2 weeks; mean age at neutering was 7.7 months (range 3.0-12.0 months); and four cats were littermates. Fourteen femoral head and neck ostectomies, eight total hip replacements and one primary fixation were performed. All 13 histologically available samples confirmed the diagnosis of SCFE. Conclusions and relevance To date, SCFE has been reported only occasionally in Maine Coon cats. However, the results of this study showed that Maine Coons were approximately 12-fold more likely to develop SCFE than the overall population of cats presenting to the Tierklinik Hollabrunn over the same time period. Male sex, neutering, delayed physeal closure and breed-specific high body weight may play an important role in the pathogenesis of SCFE in Maine Coon cats.

  4. Cat Scratch Disease (For Parents)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Cat Scratch Disease KidsHealth > For Parents > Cat Scratch Disease Print A A A What's in ... Doctor en español Enfermedad por arañazo de gato Cat scratch disease is a bacterial infection that a ...

  5. Vibrational Schroedinger Cats

    NASA Technical Reports Server (NTRS)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.

    1996-01-01

    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  6. CAT altitude avoidance system

    NASA Technical Reports Server (NTRS)

    Gary, B. L. (Inventor)

    1982-01-01

    A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an ""average'' range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer. If CAT has been detected in the general area, then the aircraft can be flown at an altitude to avoid the tropopause or inversion layer.

  7. Blood volume of nonsplenectomized and splenectomized cats before and after acute hemorrhage

    SciTech Connect

    Breznock, E.M.; Strack, D.

    1982-10-01

    Blood volume (BV) was determined in awake, nonsplenectomized (NSPX) and splenectomized (SPX) cats before and after hemorrhage (6 ml/kg). Each NSPX cat had a determined BV at least 10 ml/kg greater than the same cat after splenectomy. The mean BV of SPX cats was 43.4 +/- 8.94. ml kg (4.3% of body weight). The calculated RBC masses of NSPX and SPX cats were 17.0 +/- 4.07 and 12.2 +/- 1.12 ml/kg, respectively. Each NSPX cat had apparent RBC masses of 5 ml/kg greater than that of the same cat after splenectomy was done. At 1 hour after a hemorrhage, the BV and RBC masses determined in SPX cats were 46.7 +/- 12.1 and 9.7 +/- 1.90 ml/kg, respectively. Extravascular-to-intravascular fluid flux (calculated from RBC masses and plasma protein dilution) was approximately 0.80% of body weight. The indirect method with /sup 51/Cr-labeled RBC for BV determination was accurate and precise in awake, SPX cats; in awake, NSPX cats, the /sup 51/Cr-labeled RBC dilution method was precise, but not accurate. The spleen in the cat resulted in marked overestimations of BV and RBC masses.

  8. Interaction of central venous pressure, intramuscular pressure, and carotid baroreflex function

    NASA Technical Reports Server (NTRS)

    Shi, X.; Foresman, B. H.; Raven, P. B.; Blomqvist, C. G. (Principal Investigator)

    1997-01-01

    Seven healthy volunteer men participated in an experiment involving lower body positive pressure (LBPP) of 30 Torr and acute volume expansions of 5-6% (VE-I) and 9-10% (VE-II) of their total blood volume (TBV) to differentiate the effect of increased intramuscular pressure and central venous pressure (CVP) on the maximal gain (Gmax) of the carotid baroreflex. During each experimental condition, the heart rate (HR), mean arterial pressure (MAP; intraradial artery or Finapres), and CVP (at the 3rd-4th intercostal space) were monitored continuously. Gmax was derived from the logistic modeling of the HR and MAP responses to ramped changes in carotid sinus transmural pressure using a protocol of pulsatile changes in neck chamber pressure from +40 to -65 Torr. The increase in CVP during +30-Torr LBPP was 1.5 mmHg (P < 0.05) and was similar to that observed during VE-I (1.7 mmHg, P > 0.05). The Gmax of the carotid baroreflex of HR and MAP was significantly decreased during LBPP by -0.145 +/- 0.039 beats x min(-1) x mmHg(-1) (38%) and -0.071 +/- 0.013 mmHg/mmHg (25%), respectively; however, VE-I did not affect Gmax. During VE-II, CVP was significantly greater than that elicited by LBPP, and the Gmax of the carotid baroreflex of the HR and MAP responses was significantly reduced. We conclude that carotid baroreflex responsiveness was selectively inhibited by increasing intramuscular pressure, possibly resulting in an activation of the intramuscular mechanoreceptors during LBPP. Furthermore, it would appear that the inhibition of the carotid baroreflex, via cardiopulmonary baroreceptor loading (increased CVP), occurred when a threshold pressure (CVP) was achieved.

  9. Who Is at Risk for Carotid Artery Disease?

    MedlinePlus

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

  10. Prostatic carcinoma in two cats.

    PubMed

    Caney, S M; Holt, P E; Day, M J; Rudorf, H; Gruffydd-Jones, T J

    1998-03-01

    Clinical, radiological and pathological features of two cats with prostatic carcinoma are reported. In both cats the presenting history included signs of lower urinary tract disease with haematuria and dysuria. Prostatomegaly was visible radiographically in one cat; an irregular intraprostatic urethra was seen on retrograde contrast urethrography in both cats. In one of the cats, neoplasia was suspected on the basis of a transurethral catheter biopsy. Following a poor response to palliative treatment in both cases, euthanasia was performed with histological confirmation of the diagnosis.

  11. Carotid intraplaque neovascularization quantification software (CINQS).

    PubMed

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

    2015-01-01

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

  12. Carotid artery disease following external cervical irradiation

    SciTech Connect

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

    1981-01-01

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

  13. Carotid artery disease following external cervical irradiation

    SciTech Connect

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

    1981-11-01

    A retrospective study of 910 patients surviving at least five years after cervical irradiation for Hodgkin's disease, non-Hodgkin's lymphoma, or primary head and neck neoplasms showed the incidence of stroke following cervical irradiation was 63 of 910 patients (6.3%) during a mean period of observation of nine years. This represents a trend toward an increased risk for this population over the expected incidence of 38 strokes for a matched population observed over the same period of time (p = 0.39). A prospective study of 118 similar patients currently living five years after cervical radiotherapy was performed to determine the incidence of carotid artery disease occurring as a consequence of neck irradiation. Abnormal carotid phonoangiograms (CPA) were found in 25% of the patients and abnormal oculoplethysmographs (OPG) were found in 17%. These studies represent significant carotid lesions that are not expected in such a population. It is concluded that the carotid stenoses demonstrated are most likely a consequence of prior irradiation. Patients that are five-year survivors of cervical irradiation should have noninvasive vascular laboratory studies performed as part of their routine follow-up examinations in order to detect these carotid lesions while they are occult.

  14. Genetic testing in domestic cats.

    PubMed

    Lyons, Leslie A

    2012-12-01

    Varieties of genetic tests are currently available for the domestic cat that support veterinary health care, breed management, species identification, and forensic investigations. Approximately thirty-five genes contain over fifty mutations that cause feline health problems or alterations in the cat's appearance. Specific genes, such as sweet and drug receptors, have been knocked-out of Felidae during evolution and can be used along with mtDNA markers for species identification. Both STR and SNP panels differentiate cat race, breed, and individual identity, as well as gender-specific markers to determine sex of an individual. Cat genetic tests are common offerings for commercial laboratories, allowing both the veterinary clinician and the private owner to obtain DNA test results. This article will review the genetic tests for the domestic cat, and their various applications in different fields of science. Highlighted are genetic tests specific to the individual cat, which are a part of the cat's genome.

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

    PubMed Central

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

    2016-01-01

    Background Embolic protection devices can prevent atherosclerotic emboli during carotid stenting. Newer proximal protection devices reverse flow in the internal carotid artery (ICA), leading to reduction in perioperative microemboli. The risk of stroke is high for carotid stenting of ICA lesions with a length >10 mm and/or angiographic string sign. Objective We aimed to evaluate the safety outcomes of proximal embolic protection device usage in this high-risk group. Methods This is a retrospective analysis of patients who underwent carotid stenting procedures with proximal embolic protection devices at a tertiary care center. High-risk features for adverse events with carotid stenting were identified. Peri- and postprocedural outcomes were recorded. We further compared outcomes in patients with a carotid stenosis length >10 mm to those with shorter stenosis. Results From January 2011 to December 2014, we included 27 patients; 96.3% were symptomatic and 3.7% were asymptomatic. There was a stent placement technical success rate of 100%. No major stroke or coronary events were recorded. One minor stroke event developed in one patient. A carotid lesion length >10 mm and/or angiographic string sign was noted in 21/27 patients, with an average lesion length of 14.4 mm. One patient (4.8%) in this group developed a minor stroke event. Neither a coronary nor a major stroke event was recorded in this group. There was no significant difference in the complication rate between the long lesion and the control group. Conclusion In our patient cohort, it was found that a proximal embolic protection device is safe for patients with carotid stenosis, including those with a carotid lesion length >10 mm and/or angiographic string sign. PMID:27781040

  16. Ecology Driving Genetic Variation: A Comparative Phylogeography of Jungle Cat (Felis chaus) and Leopard Cat (Prionailurus bengalensis) in India

    PubMed Central

    Mukherjee, Shomita; Krishnan, Anand; Tamma, Krishnapriya; Home, Chandrima; R, Navya; Joseph, Sonia; Das, Arundhati; Ramakrishnan, Uma

    2010-01-01

    Background Comparative phylogeography links historical population processes to current/ecological processes through congruent/incongruent patterns of genetic variation among species/lineages. Despite high biodiversity, India lacks a phylogeographic paradigm due to limited comparative studies. We compared the phylogenetic patterns of Indian populations of jungle cat (Felis chaus) and leopard cat (Prionailurus bengalensis). Given similarities in their distribution within India, evolutionary histories, body size and habits, congruent patterns of genetic variation were expected. Methodology/Principal Findings We collected scats from various biogeographic zones in India and analyzed mtDNA from 55 jungle cats (460 bp NADH5, 141 bp cytochrome b) and 40 leopard cats (362 bp NADH5, 202 bp cytochrome b). Jungle cats revealed high genetic variation, relatively low population structure and demographic expansion around the mid-Pleistocene. In contrast, leopard cats revealed lower genetic variation and high population structure with a FST of 0.86 between North and South Indian populations. Niche-model analyses using two approaches (BIOCLIM and MaxEnt) support absence of leopard cats from Central India, indicating a climate associated barrier. We hypothesize that high summer temperatures limit leopard cat distribution and that a rise in temperature in the peninsular region of India during the LGM caused the split in leopard cat population in India. Conclusions/Significance Our results indicate that ecological variables describing a species range can predict genetic patterns. Our study has also resolved the confusion over the distribution of the leopard cat in India. The reciprocally monophyletic island population in the South mandates conservation attention. PMID:21060831

  17. Early angiographic changes after carotid endarterectomy.

    PubMed

    Diaz, F G; Patel, S; Boulos, R; Mehta, B; Ausman, J I

    1982-02-01

    This report reviews the angiographic evaluation of 41 patients who underwent a carotid endarterectomy at Henry Ford Hospital. Postoperative angiograms were performed after 48 endarterectomies. Changes included the development of postoperative intimal flaps, common carotid stenosis, carotid occlusions, areas of corrugation, surface irregularities, and postendarterectomy dilatation. The development of dilatation, or the pantaloon effect, on the endarterectomized segment contributed to the limited use of angioplastic procedures. The benefits derived from a postoperative angiogram include the objective evaluation of the endarterectomized segment, the demonstration of a potentially complicating problem such as intimal flaps that could lead to restenosis, and recognition of the possible development of associated local problems. The procedure can be done with limited risks to the patients and in competent hands has low morbidity and mortality.

  18. Current status of carotid ultrasound in atherosclerosis

    PubMed Central

    2016-01-01

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

  19. An immunocytochemical mapping of somatostatin in the cat auditory cortex.

    PubMed

    Martín, F; Coveñas, R; Narváez, J A; Tramu, G

    2003-10-01

    Using an indirect immunoperoxidase technique, the localization of somatostatin-28 (1-12)-like immunoreactive fibers and cell bodies in the auditory cortex of the cat (anterior, primary, secondary, temporal, ventral, ventroposterior, posterior and dorsoposterior auditory fields) was studied. In general, the distribution of SOM-ir structures is widespread in the auditory cortex of the feline. A high density of immunoreactive fibers as well as a low density of cell bodies containing somatostatin were observed in all the layers of the eight above-mentioned auditory fields. These data indicate that somatostatin-28 (1-12) could act as a neurotransmitter and/or a neuromodulator in the auditory cortex of the cat. The origin of the SOM-ir fibers in the auditory cortex of the cat, as well as the issue of whether the cell bodies containing somatostatin-28 (1-12) are local or projecting neurons is discussed.

  20. Big cat genomics.

    PubMed

    O'Brien, Stephen J; Johnson, Warren E

    2005-01-01

    Advances in population and quantitative genomics, aided by the computational algorithms that employ genetic theory and practice, are now being applied to biological questions that surround free-ranging species not traditionally suitable for genetic enquiry. Here we review how applications of molecular genetic tools have been used to describe the natural history, present status, and future disposition of wild cat species. Insight into phylogenetic hierarchy, demographic contractions, geographic population substructure, behavioral ecology, and infectious diseases have revealed strategies for survival and adaptation of these fascinating predators. Conservation, stabilization, and management of the big cats are important areas that derive benefit from the genome resources expanded and applied to highly successful species, imperiled by an expanding human population.

  1. Carotid Artery Stenting 2013: Thumbs up

    PubMed Central

    Wagdi, Philipp

    2013-01-01

    It has been customary for interventional cardiologists involved in carotid artery stenting, to underline non-inferiority of the percutaneous technique versus surgical carotid endarterectomy. To that end, all cause morbidity and mortality figures of both methods are compared. Surgery has, in most large randomized studies, had an edge over stenting in terms of cerebrovascular adverse events. This may have partly been due to occasional indiscriminate indication for stenting in lesions and/or vessels with unfavourable characteristics (severe target vessel tortuosity and calcification, Type III aortic arch, and so on). On one hand, the author pleads for improvement of the excellent results of endarterectomy, by subjecting all patients planned for surgery to a thorough preoperative cardiological work up, including generous invasive investigation, thus reducing the incidence of perioperative myocardial infarction, heart failure and cardiac death. On the other hand, we are convinced that the results of carotid stenting should then be compared to best practice surgery. The rate of neurological adverse event rate after carotid endarterectomy at our institution lies under 0.7% at 30 days postoperatively. Specifically, the goal should be that carotid stenting underbids surgical endarterectomy, also and mainly, in terms of cerebral and cerebrovascular adverse events. Cardiac morbidity and mortality as well as laryngeal nerve palsy should no more be the main arguments for the percutaneous approach. This should easily be possible if patient selection for carotid revascularisation would be approached according to morphological criteria, in analogy with the “Syntax”-score used to optimise revascularisation strategies in coronary artery disease.

  2. First bite syndrome following ipsilateral carotid endarterectomy.

    PubMed

    Wang, Tom Kai Ming; Bhamidipaty, Venu; MacCormick, Murray

    2013-02-01

    First bite syndrome (FBS) is characterized by unilateral pain in the parotid region after the first bite of each meal, usually following ipsilateral neck surgery. The proposed mechanism is sympathetic denervation of the parotid gland, from iatrogenic injury to the sympathetic trunk supplying this gland. Local botulinum toxin injection has emerged as a promising treatment option with favorable results. To date, there are 3 published cases in the literature describing FBS after carotid endarterectomy. We present a case of a 75-year-old gentleman who developed FBS after carotid endarterectomy, to raise the awareness of this unusual and uncommon complication.

  3. Transoral carotid ultrasonography using a micro convex probe with B-flow imaging for extracranial internal carotid artery dissection.

    PubMed

    Sakima, Hirokuni; Isa, Katsunori; Anegawa, Takahiro; Kokuba, Kazuhito; Nakachi, Koh; Goya, Yoshino; Tokashiki, Takashi; Ishiuchi, Shogo; Ohya, Yusuke

    2012-11-01

    We report on transoral carotid ultrasonography using a micro convex probe with B-flow imaging for determining spontaneous extracranial internal carotid artery dissection just below the petrous portion. A 49-year-old man suffered cortical and subcortical infarction in the region of the right middle cerebral artery. Magnetic resonance angiography on the third day of admission revealed spontaneous recanalization of the right internal carotid artery associated with an intimal flap-like structure at the petrous portion. Transoral carotid ultrasonography using a micro convex probe revealed right extracranial internal carotid artery dissection, showing an increased diameter of the right extracranial internal carotid artery with double lumen formation, stenosis of the true lumen, and a mobile intimal flap in B-flow imaging. Transoral carotid ultrasonography using a micro convex probe was helpful to attempt a self-expanding stent for recanalizing right extracranial internal carotid artery dissection. The patient recovered and was discharged ambulatory. The size of the micro convex probe was optimum for transoral carotid ultrasonography in our patient. Micro convex probe is more commonly used than the standard transoral carotid ultrasonography probe, which lacks versatility. We consider that transoral carotid ultrasonography using a micro convex probe could be routinely used for ultrasonographic evaluation of extracranial internal carotid artery dissection.

  4. Effects of stressors on the behavior and physiology of domestic cats.

    PubMed

    Stella, Judi; Croney, Candace; Buffington, Tony

    2013-01-31

    Feline interstitial cystitis (FIC) is a chronic pain syndrome of domestic cats. Cats with FIC have chronic, recurrent lower urinary tract signs (LUTS) and other comorbid disorders that are exacerbated by stressors. The aim of this study was to evaluate behavioral and physiological responses of healthy cats and cats diagnosed with FIC after exposure to a five day stressor. Ten healthy cats and 18 cats with FIC were housed at The Ohio State University Veterinary Medical Center (OSUVMC) vivarium. All cats were housed in enriched cages for at least one year prior to the experiment. Cats had daily play time and socialization outside of the cage, food treats and auditory enrichment. The daily husbandry schedule was maintained at a consistent time of day and cats were cared for by two familiar caretakers. During the test days, cats were exposed to multiple unpredictable stressors which included exposure to multiple unfamiliar caretakers, an inconsistent husbandry schedule, and discontinuation of play time, socialization, food treats, and auditory enrichment. Sickness behaviors (SB), including vomiting, diarrhea, anorexia or decreased food and water intake, fever, lethargy, somnolence, enhanced pain-like behaviors, decreased general activity, body care activities (grooming), and social interactions, were recorded daily. Blood samples were collected in the morning, before and after the stress period, for measurement of serum cortisol concentration, leukocytes, lymphocytes, neutrophils, neutrophil: lymphocyte (N:L) ratio and mRNA for the cytokines interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Overall, the short term stressors led to a significant increase in SB in both healthy cats and cats with FIC, whereas lymphopenia and N:L changes occurred only in FIC cats. Daily monitoring of cats for SB may be a noninvasive and reliable way to assess stress responses and overall welfare of cats housed in cages.

  5. Unilateral Direct Carotid Cavernous Fistula Causing Bilateral Ocular Manifestation

    PubMed Central

    Demartini Jr., Zeferino; Liebert, Fernando; Gatto, Luana Antunes Maranha; Jung, Thiago Simiano; Rocha Jr., Carlos; Santos, Alex Marques Borges; Koppe, Gelson Luis

    2015-01-01

    Unilateral carotid cavernous fistula presents with ipsilateral ocular findings. Bilateral presentation is only seen in bilateral fistulas, usually associated with indirect (dural) carotid cavernous fistulas. Direct carotid cavernous fistulas are an abnormal communication between the internal carotid artery and the cavernous sinus. They typically begin with a traumatic disruption in the artery wall into the cavernous sinus, presenting with a classic triad of unilateral pulsatile exophthalmos, cranial bruit and episcleral venous engorgement. We report the case of a 38-year-old male with traumatic right carotid cavernous sinus fistula and bilateral ocular presentation successfully treated by interventional neuroradiology. PMID:26955353

  6. An Integrated Backscatter Ultrasound Technique for the Detection of Coronary and Carotid Atherosclerotic Lesions

    PubMed Central

    Kawasaki, Masanori

    2015-01-01

    The instability of carotid and coronary plaques has been reported to be associated with acute coronary syndrome, strokes and other cerebrovascular events. Therefore, recognition of the tissue characteristics of carotid and coronary plaques is important to understand and prevent coronary and cerebral artery disease. Recently, an ultrasound integrated backscatter (IB) technique has been developed. The ultrasound IB power ratio is a function of the difference in acoustic characteristic impedance between the medium and target tissue, and the acoustic characteristic impedance is determined by the density of tissue multiplied by the speed of sound. This concept allows for tissue characterization of carotid and coronary plaques for risk stratification of patients with coronary and cerebral artery disease. Two- and three-dimensional IB color-coded maps for the evaluation of tissue components consist of four major components: fibrous, dense fibrosis, lipid pool and calcification. Although several ultrasound techniques using special mathematical algorithms have been reported, a growing body of literature has shown the reliability and usefulness of the IB technique for the tissue characterization of carotid and coronary plaques. This review summarizes concepts, experimental procedures, image reliability and the application of the IB technique. Furthermore, the IB technique is compared with other techniques. PMID:25574937

  7. An integrated backscatter ultrasound technique for the detection of coronary and carotid atherosclerotic lesions.

    PubMed

    Kawasaki, Masanori

    2015-01-07

    The instability of carotid and coronary plaques has been reported to be associated with acute coronary syndrome, strokes and other cerebrovascular events. Therefore, recognition of the tissue characteristics of carotid and coronary plaques is important to understand and prevent coronary and cerebral artery disease. Recently, an ultrasound integrated backscatter (IB) technique has been developed. The ultrasound IB power ratio is a function of the difference in acoustic characteristic impedance between the medium and target tissue, and the acoustic characteristic impedance is determined by the density of tissue multiplied by the speed of sound. This concept allows for tissue characterization of carotid and coronary plaques for risk stratification of patients with coronary and cerebral artery disease. Two- and three-dimensional IB color-coded maps for the evaluation of tissue components consist of four major components: fibrous, dense fibrosis, lipid pool and calcification. Although several ultrasound techniques using special mathematical algorithms have been reported, a growing body of literature has shown the reliability and usefulness of the IB technique for the tissue characterization of carotid and coronary plaques. This review summarizes concepts, experimental procedures, image reliability and the application of the IB technique. Furthermore, the IB technique is compared with other techniques.

  8. MR coil sensitivity inhomogeneity correction for plaque characterization in carotid arteries

    NASA Astrophysics Data System (ADS)

    Salvado, Olivier; Hillenbrand, Claudia; Suri, Jasjit; Wilson, David L.

    2004-05-01

    We are involved in a comprehensive program to characterize atherosclerotic disease using multiple MR images having different contrast mechanisms (T1W, T2W, PDW, magnetization transfer, etc.) of human carotid and animal model arteries. We use specially designed intravascular and surface array coils that give high signal-to-noise but suffer from sensitivity inhomogeneity. With carotid surface coils, challenges include: (1) a steep bias field with an 80% change; (2) presence of nearby muscular structures lacking high frequency information to distinguish bias from anatomical features; (3) many confounding zero-valued voxels subject to fat suppression, blood flow cancellation, or air, which are not subject to coil sensitivity; and (4) substantial noise. Bias was corrected using a modification of the adaptive fuzzy c-mean method reported by Pham et al. (IEEE TMI, 18:738-752), whereby a bias field modeled as a mechanical membrane was iteratively improved until cluster means no longer changed. Because our images were noisy, we added a noise reduction filtering step between iterations and used about 5 classes. In a digital phantom having a bias field measured from our MR system, variations across an area comparable to a carotid artery were reduced from 50% to <5% with processing. Human carotid images were qualitatively improved and large regions of skeletal muscle were relatively flat. Other commonly applied techniques failed to segment the images or introduced strong edge artifacts. Current evaluations include comparisons to bias as measured by a body coil in human MR images.

  9. The Use of Refuges by Communally Housed Cats

    PubMed Central

    Sicuto de Oliveira, Adriana; Terçariol, César Augusto Sangaletti; Genaro, Gelson

    2015-01-01

    Simple Summary Captive domestic cats frequently suffer from the lack of physical space and opportunities to perform species-typical behaviors, such as climbing or hiding. Environmental enrichment is a technique that helps transform the space available to animals into a more appropriate habitat. In this study, we tested horizontal and vertical refuge boxes as environmental enrichment for cats living communally in a cat rescue shelter. The provision of boxes in the environment increases the use of available space by the cats. We suggest this improves the cats’ welfare while in communally-housed rescue shelters. Abstract The increase of domestic animals kept in shelters highlights the need to ensure animal welfare. Environmental enrichment can improve animal welfare in many ways, such as encouraging captive animals to use all the space available to them. The effects of physical environmental enrichment on the spatial distribution and behavioral repertoire of 35 neutered domestic cats housed communally were analyzed. The provision of boxes in the environment increases the use of available space by the cats. We suggest this improves the cats’ welfare while in communally-housed rescue shelters. The frequencies of active and especially inactive behaviors also increased in the enriched condition. In a test with vertical environmental enrichment, the animals showed an increased length of stay in refuges located at a height of 0.5 m compared to those on the ground (0.0 m). However, the entry frequency was higher in refuges at 0.0 m. Both horizontal and vertical environmental enrichment increased the use of available space, demonstrating that box refuges as enrichment are effective in providing a refuge when at a height, or a place to explore at ground level. We suggest it enhances the welfare of cats in communally housed shelters. This information adds to the body of evidence relating to cat enrichment and can be useful in designing cat housing in veterinary clinics

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

    PubMed

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

    2016-10-01

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

  11. Rheoreceptors in the carotid sinus of dog.

    PubMed Central

    Hajduczok, G; Chapleau, M W; Abboud, F M

    1988-01-01

    The arterial baroreceptors are known to be sensitive to changes in pressure but there are no known sensors in the cardiovascular system for changes in flow. We tested the hypothesis that changes in flow at constant pressure alter carotid sinus multi-unit nerve activity. In anesthetized dogs with vascularly isolated carotid sinuses, increases in flow at constant pressure resulted in increases in carotid sinus nerve activity in relation to the increase in flow. The increased activity during flow was not caused by an increase in strain of the sinus wall but was directly related to the increase in shear stress (36.6 +/- 11.7% increase in activity per dyne/cm2; 1 dyne = 0.1 MN). The pressure threshold of single baroreceptor units was determined during a slow pressure ramp with and without flow. Flow caused a significant decrease in pressure threshold from 81.1 +/- 6.1 mmHg (1 mmHg = 1.333 x 10(2) Pa) in the absence of flow to 69.3 +/- 5.7 mmHg with flow. We conclude that there are arterial "rheoreceptors" in the carotid sinus that respond to flow at constant pressure and strain. The results with single baroreceptor units indicate also that baroreceptors may be sensitized by increases in flow. Thus, changes in flow per se in addition to changes in arterial pressure may be important determinants of reflex circulatory adjustments. PMID:3174642

  12. A review of over three decades of research on cat-human and human-cat interactions and relationships.

    PubMed

    Turner, Dennis C

    2017-01-22

    This review article covers research conducted over the last three decades on cat-human and human-cat interactions and relationships, especially from an ethological point of view. It includes findings on cat-cat and cat-human communication, cat personalities and cat-owner personalities, the effects of cats on humans, and problems caused by cats.

  13. [Carotid body paraganglioma in a teenager. Case report].

    PubMed

    López-Vázquez, María Elisa; Llamas-Macías, Francisco Javier; Nuño-Escobar, César; González-Ojeda, Alejandro; Fuentes-Orozco, Clotilde; Macías-Amezcua, Michel Dassaejv

    2014-01-01

    Antecedentes: los paragangliomas de cabeza y cuello son tumores neuroendocrinos de baja incidencia (0.6%), en su mayor parte benignos, en cuyo origen se han involucrado múltiples factores. Los seres humanos y otras especies que viven a grandes alturas (por arriba de 2000 metros sobre el nivel del mar) son propensos a sufrir hipoxia crónica relativa, hiperplasia del cuerpo carotídeo y, eventualmente, paragangliomas. Este padecimiento aparece en la quinta década de la vida y en la tercera, en caso de presentación familiar. Caso clínico: se comunica el caso de una adolescente de 16 años de edad que un año antes tuvo faringitis aguda con tumor localizado en la cara lateral izquierda del cuello, de crecimiento gradual, sin ningún síntoma. El ultrasonido Doppler dúplex de cuello mostró una lesión nodular sólida sobre el trayecto de la bifurcación carotídea izquierda. Fue intervenida quirúrgicamente mediante cervicotomía lateral izquierda, en la cual se encontró una tumoración de aproximadamente 4 × 3 × 3 cm, sumamente vascularizada, que afectaba la carótida común desde su tercio medio, la carótida interna hasta la base del cráneo y la carótida externa hasta el tercio superior, con íntima relación con la tráquea, el esófago y la columna cervical. La tumoración se resecó en su totalidad, el estudio histopatológico corroboró los paragangliomas. Conclusiones: la edad de presentación es poco común, por lo que se considera relevante y de interés clínico comunicar este caso, toda vez que debe considerarse como posibilidad diagnóstica.

  14. Ventilatory Responsiveness of Goats with Ablated Carotid Bodies,

    DTIC Science & Technology

    1982-06-03

    and a non- rebreathing valve into a circuit made up of wide-bore tubing and a CO2 absorber, with a T-piece connector leadingI2 to a bag-in-box...Words: CO2 production, CSF, CO2 rebreathing , cyanide, awake goats. L’ J .A __ 20. AsTh ACT (raetu sm reverse L N n .mllasy mad fdeWlby block number...hypercapniaafterCBx, the goats responded to hyperoxic CO2 rebreathing with a similar increase in ventilation before and after CBx. We conclude that the

  15. Carotid body chemoreception: mechanisms and dynamic protection against apnea.

    PubMed

    Lahiri, S

    1994-01-01

    A critical role of peripheral chemoreceptors in terminating apnea and in initiating normal breathing has been emphasized. Since these are the only organs which signal hypoxia, failure of its adequate development can contribute to the disease of respiratory failure in neonatal life. The failure may reside in any of the steps from initiation of O2 chemoreception involving respiratory and non-respiratory pigments, ion balance including H+ and Ca2+, neurotransmitter mechanisms and transduction.

  16. Raccoonpox in a Canadian cat.

    PubMed

    Yager, Julie A; Hutchison, Lisa; Barrett, John W

    2006-12-01

    Poxvirus infections affecting the skin of cats are extremely rare in North America, in contrast to Europe where cowpox virus is well recognized as an accidental pathogen in cats that hunt small rodents. The virus or viruses responsible for the anecdotal cases in North America have never been characterized. This paper reports a case of raccoonpox infection in a Canadian cat. Biopsy of the initial ulcerative lesion on the forepaw revealed ballooning degeneration of surface and follicular keratinoctyes. Infected cells contained large eosinophilic type A inclusions. Electron microscopic examination revealed virions of an orthopoxvirus, subsequently identified as raccoonpox by polymerase chain reaction and gene sequencing. The cat made a full recovery.

  17. External hydrocephalus in two cats.

    PubMed

    Dewey, Curtis W; Coates, Joan R; Ducoté, Julie M; Stefanacci, Joseph D; Walker, Michael A; Marino, Dominic J

    2003-01-01

    External hydrocephalus describes an accumulation of cerebrospinal fluid (CSF) between the cerebral hemispheres and the overlying arachnoid membrane, rather than within the lateral ventricles. Two young cats with encephalopathic signs were diagnosed with external hydrocephalus, one via magnetic resonance imaging and one via computed tomography. Both cats had abnormally large, broad heads, with no evidence of open fontanelles. A surgical shunt was placed in each cat to divert the accumulated CSF within the cranial cavity to the peritoneal space. Both cats improved dramatically soon after surgical shunting was performed, and they continue to do well clinically, approximately 42 months and 8 months postoperatively, respectively.

  18. Management of carotid stenosis. History and today

    PubMed Central

    Jargiełło, Tomasz; Drelich-Zbroja, Anna

    2013-01-01

    Internal carotid stenosis constitutes a significant clinical challenge, since it is the cause of 20–25% of ischemic brain strokes. The management of the internal carotid stenosis for many years has been raising controversies amongst neurologists, vascular surgeons and interventional radiologists mainly due to the introduction of endovascular stenting as an alternative to surgical treatment. Its application, however, requires knowledge of specific selection criteria for this kind of treatment as well as of the methods of monitoring patients after stent implantation into the internal carotid artery. Duplex Doppler ultrasound examination is currently a basis for the diagnosis of the arterial stenosis of precranial segments of the carotid arteries. It allows a reliable assessment of not only the course and morphology of the walls, but also of the hemodynamics of blood flow. Interventional treatment is applicable in patients with internal carotid stenosis of ≥70%, which is accompanied by an increase of the systolic flow velocity above 200 cm/s and the end-diastolic velocity above 50–60 cm/s in the stenotic lumen. In most cases, such a diagnosis in duplex Doppler ultrasound examination does not require any confirmation by additional diagnostic methods and if neurological symptoms are also present, it constitutes a single indication for interventional treatment. When deciding about choice of surgical or endovascular method of treatment, the following factors are of crucial importance: morphology of atherosclerotic plaque, its size, echogenicity, homogeneity of its structure, its surface and outlines. By means of ultrasound examinations, patients can be monitored after endovascular stent implantation. They enable evaluation of the degree of stent patency and allow for an early detection of symptoms indicating stenosis recurrence or presence of in-stent thrombosis. When interpreting the findings of the US checkup, it is essential to refer to the initial examination

  19. Management of carotid stenosis. History and today.

    PubMed

    Szczerbo-Trojanowska, Małgorzata; Jargiełło, Tomasz; Drelich-Zbroja, Anna

    2013-03-01

    Internal carotid stenosis constitutes a significant clinical challenge, since it is the cause of 20-25% of ischemic brain strokes. The management of the internal carotid stenosis for many years has been raising controversies amongst neurologists, vascular surgeons and interventional radiologists mainly due to the introduction of endovascular stenting as an alternative to surgical treatment. Its application, however, requires knowledge of specific selection criteria for this kind of treatment as well as of the methods of monitoring patients after stent implantation into the internal carotid artery. Duplex Doppler ultrasound examination is currently a basis for the diagnosis of the arterial stenosis of precranial segments of the carotid arteries. It allows a reliable assessment of not only the course and morphology of the walls, but also of the hemodynamics of blood flow. Interventional treatment is applicable in patients with internal carotid stenosis of ≥70%, which is accompanied by an increase of the systolic flow velocity above 200 cm/s and the end-diastolic velocity above 50-60 cm/s in the stenotic lumen. In most cases, such a diagnosis in duplex Doppler ultrasound examination does not require any confirmation by additional diagnostic methods and if neurological symptoms are also present, it constitutes a single indication for interventional treatment. When deciding about choice of surgical or endovascular method of treatment, the following factors are of crucial importance: morphology of atherosclerotic plaque, its size, echogenicity, homogeneity of its structure, its surface and outlines. By means of ultrasound examinations, patients can be monitored after endovascular stent implantation. They enable evaluation of the degree of stent patency and allow for an early detection of symptoms indicating stenosis recurrence or presence of in-stent thrombosis. When interpreting the findings of the US checkup, it is essential to refer to the initial examination

  20. Intracranial Carotid Calcification on Cranial Computed Tomography

    PubMed Central

    Subedi, Deepak; Zishan, Umme Sara; Chappell, Francesca; Gregoriades, Maria-Lena; Sudlow, Cathie; Sellar, Robin

    2015-01-01

    Background and Purpose— Intracranial internal carotid artery calcification is associated with cerebrovascular risk factors and stroke, but few quantification methods are available. We tested the reliability of visual scoring, semiautomated Agatston score, and calcium volume measurement in patients with recent stroke. Methods— We used scans from a prospective hospital stroke registry and included patients with anterior circulation ischemic stroke or transient ischemic stroke whose noncontrast cranial computed tomographic scans were available electronically. Two raters measured semiautomatic quantitative Agatston score, and calcium volume, and performed qualitative visual scoring using the original 4-point Woodcock score and a modified Woodcock score, where each image on which the internal carotid arteries appeared was scored and the slice scores summed. Results— Intra- and interobserver coefficient of variations were 8.8% and 16.5% for Agatston, 8.8% and 15.5% for calcium volume, and 5.7% and 5.4% for the modified Woodcock visual score, respectively. The modified Woodcock visual score correlated strongly with both Agatston and calcium volume quantitative measures (both R2=0.84; P<0.0001); calcium volume increased by 0.47-mm/point increase in modified Woodcock visual score. Intracranial internal carotid artery calcification increased with age by all measures (eg, visual score, Spearman ρ=0.4; P=0.005). Conclusions— Visual scores correlate highly with quantitative intracranial internal carotid artery calcification measures, with excellent observer agreements. Visual intracranial internal carotid artery scores could be a rapid and practical method for epidemiological studies. PMID:26251250

  1. Systemic cat scratch disease.

    PubMed

    Liao, Hui-Min; Huang, Fu-Yuan; Chi, Hsin; Wang, Nieu-Lu; Chen, Be-Fong

    2006-08-01

    Systemic cat scratch disease (CSD) is often associated with prolonged fever and microabscesses in the liver and/or spleen. We report a case of systemic CSD with hepatic, splenic and renal involvement in an aboriginal child in Taiwan. A previously healthy 9-year-old girl had an intermittent fever for about 17 days, and complained of abdominal pain, headache and weight loss. Abdominal computed tomography showed multiple tiny hypodense nodular lesions in the spleen and both kidneys. Laparotomy revealed multiple soft, whitish-tan lesions on the surface of the liver and spleen. Histopathologic examination of a biopsy specimen of the spleen showed necrotizing granulomatous inflammation with central necrosis surrounded by epithelioid cells and occasional Langhans' giant cells, strongly suggestive of Bartonella henselae infection. History revealed close contact with a cat. B. henselae DNA was detected by polymerase chain reaction in the tissue specimen, and the single antibody titer against B. henselae was greater than 1:2048. These results confirmed the diagnosis of visceral CSD caused by B. henselae. The patient's symptoms resolved after treatment with rifampin and tetracycline. This case illustrates the need for inclusion of systemic CSD in patients with fever of unknown origin and abdominal pain.

  2. Anatomical Considerations on Surgical Anatomy of the Carotid Bifurcation

    PubMed Central

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

    2016-01-01

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

  3. Differential effect of central command on aortic and carotid sinus baroreceptor-heart rate reflexes at the onset of spontaneous, fictive motor activity.

    PubMed

    Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Liang, Nan; Ishida, Tomoko

    2012-08-15

    Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, fictive motor activity in paralyzed, decerebrate cats. We confirmed that aortic nerve (AN)-stimulation-induced bradycardia was markedly blunted to 26 ± 4.4% of the control (21 ± 1.3 beats/min) at the onset of spontaneous motor activity. Although the baroreflex bradycardia by electrical stimulation of the carotid sinus nerve (CSN) was suppressed (P < 0.05) to 86 ± 5.6% of the control (38 ± 1.2 beats/min), the inhibitory effect of spontaneous motor activity was much weaker (P < 0.05) with CSN stimulation than with AN stimulation. The baroreflex bradycardia elicited by brief occlusion of the abdominal aorta was blunted to 36% of the control (36 ± 1.6 beats/min) during spontaneous motor activity, suggesting that central command is able to inhibit the cardiomotor sensitivity of arterial baroreflexes as the net effect. Mechanical stretch of the triceps surae muscle never affected the baroreflex bradycardia elicited by AN or CSN stimulation and by aortic occlusion, suggesting that muscle mechanoreflex did not modify the cardiomotor sensitivity of aortic and carotid sinus baroreflex. Since the inhibitory effect of central command on the carotid baroreflex pathway, associated with spontaneous motor activity, was much weaker compared with the aortic baroreflex pathway, it is concluded that central command does not force a generalized modulation on the whole pathways of arterial baroreflexes but provides selective inhibition for the cardiomotor component of the aortic baroreflex.

  4. Dermal mass aspirate from a Persian cat.

    PubMed

    Zimmerman, Kurt; Feldman, Bernard; Robertson, John; Herring, Erin S; Manning, Thomas

    2003-01-01

    A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5-1.0 microm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis, and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.

  5. Hypertensive retinopathy in a cat

    PubMed Central

    Van Boxtel, Sherry A.

    2003-01-01

    A 12-year-old cat presented for sudden blindness was diagnosed with hypertensive retinopathy on the basis of ophthalmologic and ultrasonic examination. Renal failure due to a large intranephric cyst obstructing the right ureter and renal artery was the suggested cause of the systemic hypertension. The cat died 8 hours after unilateral nephrectomy. PMID:12650046

  6. Oral masses in two cats.

    PubMed

    Bock, P; Hach, V; Baumgärtner, W

    2011-07-01

    Incisional biopsies from the oral cavity of 2 adult cats were submitted for histological investigation. Cat No. 1 showed a solitary well-circumscribed neoplasm in the left mandible. Cat No. 2 demonstrated a diffusely infiltrating neoplasm in the left maxilla. Both tumors consisted of medium-size epithelial cells embedded in a fibrovascular stroma. The mitotic index was 0 to 1 mitosis per high-power field. The epithelial cells showed an irregular arrangement forming nests or streams in cat No. 1, whereas a palisading growth was noted in cat No. 2. Both tumors, especially that of cat No. 1, showed multifocal accumulations of amyloid as confirmed by Congo red staining and a distinct green birefringence under polarized light, which lacked cytokeratin immunoreactivity as well as and AL and AA amyloid immunoreactivity. In addition, the amyloid in cat No. 2 was positive for the odontogenic ameloblast-associated protein, formerly termed APin. In sum, both cats suffered from an amyloid-producing odontogenic tumor, but their tumors varied with respect to morphology and type of amyloid produced.

  7. College Students and Their Cats

    ERIC Educational Resources Information Center

    Weinstein, Lawrence; Alexander, Ralph

    2010-01-01

    Twenty-two Siamese and 32 mixed breed cats' personalities were rated by their respective college student owners and compared. Further, the owners' self rated personality traits were correlated with the pets'; significant Siamese and Mixed differences and correlations were obtained. These are the first data to examine breed of cat on a personality…

  8. CONTRACT ADMINISTRATIVE TRACKING SYSTEM (CATS)

    EPA Science Inventory

    The Contract Administrative Tracking System (CATS) was developed in response to an ORD NHEERL, Mid-Continent Ecology Division (MED)-recognized need for an automated tracking and retrieval system for Cost Reimbursable Level of Effort (CR/LOE) Contracts. CATS is an Oracle-based app...

  9. The Use of Refuges by Communally Housed Cats.

    PubMed

    de Oliveira, Adriana Sicuto; Terçariol, César Augusto Sangaletti; Genaro, Gelson

    2015-04-24

    The increase of domestic animals kept in shelters highlights the need to ensure animal welfare. Environmental enrichment can improve animal welfare in many ways, such as encouraging captive animals to use all the space available to them. The effects of physical environmental enrichment on the spatial distribution and behavioral repertoire of 35 neutered domestic cats housed communally were analyzed. The provision of boxes in the environment increases the use of available space by the cats. We suggest this improves the cats' welfare while in communally-housed rescue shelters. The frequencies of active and especially inactive behaviors also increased in the enriched condition. In a test with vertical environmental enrichment, the animals showed an increased length of stay in refuges located at a height of 0.5 m compared to those on the ground (0.0 m). However, the entry frequency was higher in refuges at 0.0 m. Both horizontal and vertical environmental enrichment increased the use of available space, demonstrating that box refuges as enrichment are effective in providing a refuge when at a height, or a place to explore at ground level. We suggest it enhances the welfare of cats in communally housed shelters. This information adds to the body of evidence relating to cat enrichment and can be useful in designing cat housing in veterinary clinics, research laboratories, shelters and domestic homes.

  10. Comparison of gastrointestinal adverse effects of ketoprofen between adult and young cats.

    PubMed

    Takata, Kenji; Hikasa, Yoshiaki; Satoh, Hiroshi

    2012-12-01

    This study elucidated differences in predisposition to the gastrointestinal adverse effects of ketoprofen between young and adult cats. Ketoprofen was administered subcutaneously (2.0 mg/kg, s.c.) once a day for 3 days. The animals were sacrificed 24 hr after final injection to allow examination of gastrointestinal mucosal lesions. Ketoprofen caused gastric lesions in adult cats (>6 months) but not in young cats (<3 months). Ketoprofen caused more severe small intestinal lesions in adult cats than in young cats. In the study of prevention of lipopolysaccharide (LPS)-induced hyperthermia using ketoprofen, young and adult cats of both sexes were administered LPS (0.3 μg/kg, intravenously), and body temperature was measured 24 hr later. Ketoprofen was administered subcutaneously 30 min before LPS injection. LPS-induced hyperthermia was almost completely inhibited by pretreatment with ketoprofen in both adult and young cats. In the pharmacokinetics of ketoprofen, plasma concentrations were analyzed by high-performance liquid chromatography. No significant differences were observed in plasma concentrations of two mirror-image R(-) and S(+) ketoprofen between young and adult cats from 0.5-4 hr after injection. As observed in a previous study using flunixin, the degree of gastrointestinal damage was unrelated to plasma concentrations of ketoprofen. The results of this study demonstrated that ketoprofen is safer for use in young cats than in adult cats from the viewpoint of gastrointestinal adverse effects.

  11. Experimental infection with Trichinella T12 in domestic cats.

    PubMed

    Ribicich, M; Krivokapich, S; Pasqualetti, M; Gonzalez Prous, C L; Gatti, G M; Falzoni, E; Aronowicz, T; Arbusti, P; Fariña, F; Rosa, A

    2013-05-20

    Trichinella spiralis has been documented in wild animals in Argentina, including puma, armadillos, rats and wild boars. In 2008, molecular analysis identified Trichinella T12 from a naturally infected puma (Puma concolor) from Patagonia. The aim of the present work was to study the relationship between the infectivity and pathology of Trichinella T12 in the puma and in domestic cats, and the possible risks that may be present for transmission among these animals. Two cats (A and B) were orally-infected with 3300 and 1850 Trichinella T12 muscle larvae, respectively; one additional cat was used as a control. During the 54 days post-infection, a daily examination was performed which included monitoring body temperature, and cardiac and respiration rates; the animals were then euthanized. Hematological studies included hematocrit (%), hemoglobin (g/dl), and white cell, neutrophil, lymphocyte and eosinophil counts. Blood biochemistry included urea, creatinine, AST, ALT, CK, LDH and ALP. An ELISA assay was also performed. At necropsy, organs (liver, spleen, brain, cerebellum and kidney), nails and muscle samples were obtained for histopathology studies and artificial digestion. The muscles that were studied included the diaphragm, massetter, cutaneous, temporal, intercostals, lumbar, tongue, limbs, neck and tail. Clinical signs, such as anorexia, diarrhea, vomiting, shaggy hair, decay and muscle pain, were observed in both cats. The eosinophil counts were elevated in both cats A and B. Trichinella larvae were recovered from all of the muscles analyzed where the histopathology showed larvae in several muscles without degenerative reaction. Neither larvae nor lesions were observed in non-muscular organs. Cat A had a maximum of 246 larvae per gram (lpg) in the temporal muscle and a minimum of 80 lpg in the tongue, while cat B had a maximum of 65 lpg in muscles of the leg and a minimum of 10 lpg in tail muscles. This study represents the first record of experimental

  12. Is carotid sonography a useful tool for predicting functional capabilities in ischemic stroke patients following carotid artery stenting?

    PubMed Central

    Lin, Chih-Ming; Su, Jian-Chi; Chang, Yu-Jun; Liu, Chi-Kuang; Lu, Henry Horng-Shing; Jong, Yuh-Jyh

    2017-01-01

    Abstract Carotid stenosis is a major cause of stroke and timely intervention with stenting manipulation can significantly reduce the risk of secondary stroke. The impact of stenting procedures on patient functional capabilities has not yet been explored. The primary aim of this study was to examine associations between periprocedural carotid sonography parameters and post-treatment functional capabilities in stroke patients. Sixty-seven patients who received carotid stenting at 1 angiography laboratory were included. Prestenting and poststenting carotid duplex data were recorded and resistance index (RI) differences at various carotid system locations were compared. The modified Rankin Scale (mRS) was used to assess functional capability. All of the studied parameters were analyzed by SPSS (version 16.0, SPSS Inc, Chicago, IL). Following stenting, mRS scores improved (n = 44) or remained stationary (n = 23). Net contralateral internal carotid artery (ICA) RI for patients with improved mRS was lower compared to that for patients with stationary mRS (median = 0.040 vs 0.11; P = 0.003). The contralateral common carotid artery RI before and after stenting differed significantly (P < 0.050) in both. The ipsilateral ICA RI differed (P < 0.050) only in patients with improved mRS. The difference in mean transit time, Barthel index, net ipsilateral ICA RI, net contralateral external carotid artery RI, postipsilateral common carotid artery RI, and postipsilateral ICA RI differed significantly between different baseline stroke severity groups (P < 0.050). Carotid artery stenting improved physical function in a proportion of ischemic stroke patients with carotid stenosis. Carotid ultrasound is a useful assessment tool to predict likely functional outcomes following carotid artery stenting. PMID:28328821

  13. Ivermectin in the treatment of Physaloptera preputialis in two cats.

    PubMed

    Gustafson, B W

    1995-01-01

    Two mixed-breed cats were examined for intermittent vomiting of several months' duration. Adult Physaloptera preputialis nematodes were detected in the vomitus and melena was observed in both cases. Clinicopathological abnormalities including anemia and eosinophilia were found in one case. Clinical signs resolved following anthelmintic therapy with ivermectin (200 micrograms/kg body weight) administered subcutaneously.

  14. Evolution of Skull and Mandible Shape in Cats (Carnivora: Felidae)

    PubMed Central

    Christiansen, Per

    2008-01-01

    The felid family consists of two major subgroups, the sabretoothed and the feline cats, to which all extant species belong, and are the most anatomically derived of all carnivores for predation on large prey with a precision killing bite. There has been much controversy and uncertainty about why the skulls and mandibles of sabretoothed and feline cats evolved to become so anatomically divergent, but previous models have focused on single characters and no unifying hypothesis of evolutionary shape changes has been formulated. Here I show that the shape of the skull and mandible in derived sabrecats occupy entirely different positions within overall morphospace from feline cats, and that the evolution of skull and mandible shape has followed very different paths in the two subgroups. When normalised for body-size differences, evolution of bite forces differ markedly in the two groups, and are much lower in derived sabrecats, and they show a significant relationship with size and cranial shape, whereas no such relationship is present in feline cats. Evolution of skull and mandible shape in modern cats has been governed by the need for uniform powerful biting irrespective of body size, whereas in sabrecats, shape evolution was governed by selective pressures for efficient predation with hypertrophied upper canines at high gape angles, and bite forces were secondary and became progressively weaker during sabrecat evolution. The current study emphasises combinations of new techniques for morphological shape analysis and biomechanical studies to formulate evolutionary hypotheses for difficult groups. PMID:18665225

  15. Evolution of skull and mandible shape in cats (Carnivora: Felidae).

    PubMed

    Christiansen, Per

    2008-07-30

    The felid family consists of two major subgroups, the sabretoothed and the feline cats, to which all extant species belong, and are the most anatomically derived of all carnivores for predation on large prey with a precision killing bite. There has been much controversy and uncertainty about why the skulls and mandibles of sabretoothed and feline cats evolved to become so anatomically divergent, but previous models have focused on single characters and no unifying hypothesis of evolutionary shape changes has been formulated. Here I show that the shape of the skull and mandible in derived sabrecats occupy entirely different positions within overall morphospace from feline cats, and that the evolution of skull and mandible shape has followed very different paths in the two subgroups. When normalised for body-size differences, evolution of bite forces differ markedly in the two groups, and are much lower in derived sabrecats, and they show a significant relationship with size and cranial shape, whereas no such relationship is present in feline cats. Evolution of skull and mandible shape in modern cats has been governed by the need for uniform powerful biting irrespective of body size, whereas in sabrecats, shape evolution was governed by selective pressures for efficient predation with hypertrophied upper canines at high gape angles, and bite forces were secondary and became progressively weaker during sabrecat evolution. The current study emphasises combinations of new techniques for morphological shape analysis and biomechanical studies to formulate evolutionary hypotheses for difficult groups.

  16. US Domestic Cats as Sentinels for Perfluoroalkyl Substances ...

    EPA Pesticide Factsheets

    Perfluoroalkyl substances (PFAS), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) , are persistent, globally distributed, anthropogenic compounds. The primary source(s) for human exposure are not well understood although within home exposure is likely important since many consumer products have been treated with different PFAS, and people spend much of their lives indoors. Herein, domestic cats were used as sentinels to investigate potential exposure and health linkages. PFAS in serum samples of 72 pet and feral cats, including 11 healthy and 61 with one or more primary disease diagnoses, were quantitated using high-resolution time-of-flight mass spectroscopy. All but one sample had detectable PFAS, with PFOS and perfluorohexane sulfonate (PFHxS) ranging from cats were very similar to contemporary NHANES reports of human sera in the U. S. POPULATION: The highest PFAS serum concentrations detected were in indoor cats due to disproportionately elevated PFHxS levels. Ranked by quartile, contingency testing indicated that total PFAS levels were positively associated with living indoors and with higher body weight and body condition scores. Individual PFAS quartile rankings suggested positive associations with respiratory effusion, thyroid, liver, and possibly chronic kidney disease . Domestic cats appear to be useful sentinels for assessing primary

  17. Estimation of Stiffness Parameter on the Common Carotid Artery

    NASA Astrophysics Data System (ADS)

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

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

  18. An internal carotid artery aneurysm presenting with dysarthria.

    PubMed

    Davey, P T; Rychlik, I; O'Donnell, M; Baker, R; Rennie, I

    2013-10-01

    A 72-year-old woman presented to her general practitioner with a 4-week history of right neck swelling. Clinical examination elicited a pulsatile mass consistent with a carotid artery aneurysm. Five days later the patient noticed her tongue movements had become awkward with associated dysarthria. Computed tomography confirmed a 4cm internal carotid artery aneurysm arising just distally to the carotid bifurcation. She proceeded to transfemoral diagnostic carotid angiography. Balloon occlusion of the right internal carotid artery origin was performed for a ten-minute period without any neurological deficit. The decision was taken to proceed to surgical ligation of the origin of the internal carotid artery. Her symptoms of dysarthria have resolved.

  19. Symptomatic carotid ischaemic events: safest and most cost effective way of selecting patients for angiography, before carotid endarterectomy.

    PubMed Central

    Hankey, G J; Warlow, C P

    1990-01-01

    OBJECTIVE: To determine the safest, least costly, and most effective way to select patients with symptomatic carotid ischaemic events for carotid angiography before carotid endarterectomy. DESIGN: Prospective cohort study. SETTING: University departments of clinical neurosciences and clinical neurology. PATIENTS: 485 Patients with carotid territory transient ischaemic attacks of the brain (n = 224) or eye (n = 162) or retinal infarction (n = 99) were referred to a single neurologist between 1976 and 1986. INTERVENTIONS: Clinical examination by auscultation over the precordium, supraclavicular fossae, and neck vessels (all patients). Cerebral angiography of patients suitable for carotid endarterectomy. MAIN OUTCOME MEASURES: Financial cost and number of disabling strokes after angiography. RESULTS: 296 Patients were investigated by cerebral angiography. Ischaemic symptoms had occurred in the distribution of 298 internal carotid arteries (symptomatic) that were imaged, two patients having bilateral symptoms. The presence or absence of a carotid bruit and the maximum percentage diameter stenosis of the origin of the symptomatic internal carotid artery were correlated. The prevalence of mild disease (diameter stenosis greater than or equal to 25%) of the symptomatic internal carotid artery was 57%, and if an ipsilateral carotid bruit was heard the probability of mild stenosis rose to 92%. The prevalence of moderate disease of the symptomatic internal carotid artery (stenosis greater than or equal to 50%) was 39%, and if a bruit was heard the probability doubled to 78%. The prevalence of severe internal carotid disease (stenosis greater than or equal to 75%) was 22%, and if a bruit was heard the probability was more than double, at 49%. The direct cost to both the NHS and the private health sector of investigating patients with symptomatic carotid ischaemia was estimated for several strategies of carotid artery imaging and expressed in terms of financial cost and number

  20. How cats lap

    NASA Astrophysics Data System (ADS)

    Stocker, Roman; Reis, Pedro; Jung, Sunghwan; Aristoff, Jeffrey

    2010-11-01

    We studied the lapping of the domestic cat (Felis catus) by combining high-speed photography with a laboratory model of lapping. We found that Felis catus laps by a subtle mechanism based on water adhesion to the dorsal side of the tongue and the creation of a liquid column, exploiting inertia to defeat gravity and pull liquid into the mouth. The competition between inertia and gravity controls the pinch-off time of the column, determining the optimal lapping frequency, f. Felis catus was found to operate near the optimum and theoretical analysis yielded a scaling, f ˜M-1/6, of lapping frequency with animal mass, M. This prediction was verified by measuring lapping frequency across felids, from ocelots to lions, suggesting that the lapping mechanism is conserved among felines.

  1. Carotid Baroreflex Activation: Past, Present, and Future

    PubMed Central

    Scheffers, Ingrid J. M.; Kroon, Abraham A.

    2010-01-01

    Electrical activation of the carotid baroreceptor system is an attractive therapy for the treatment of resistant hypertension. In the past, several attempts were made to directly activate the baroreceptor system in humans, but the method had to be restricted to a few selected patients. Adverse effects, the need for better electrical devices and better surgical techniques, and the lack of knowledge about long-term effects has greatly hampered developments in this area for many years. Recently, a new and promising device was evaluated in a multicenter feasibility trial, which showed a clinically and statistically significant reduction in office systolic blood pressure (>20 mm Hg). This reduction could be sustained for at least 2 years with an acceptable safety profile. In the future, this new device may stimulate further application of electrical activation of the carotid baroreflex in treatment-resistant hypertension. PMID:20424959

  2. Review of stents for the carotid artery.

    PubMed

    Bosiers, M; Deloose, K; Verbist, J; Peeters, P

    2006-04-01

    The individual characteristics of a stent may make it an attractive choice in some circumstances, but render it a less desirable option in others. The applicability depends primarily on the arterial anatomy and the specific details of the lesion being treated. A careful assessment by the interventionalist is required to select the proper type of stent that is of appropriate size. Certainly, personal preferences and familiarity with a specific device may legitimately influence the decision to choose one stent over another. Finally, stent design can play a role in the selection procedure. Although carotid stents are often functionally equivalent in the clinical setting and have been used successfully to treat a wide variety of lesions, a basic knowledge of stent geometry can contribute to make up your mind in certain carotid cases.

  3. [Carotid surgery, indications, results and perspectives].

    PubMed

    Kün, P; Battino, J; Cloarec, M; Witchitz, S; Vanet, R; Mergy, R

    1985-01-01

    A series of 215 patients who had undergone 250 carotid artery operations were followed up for a mean of 30 months. Perioperative mortality was 2%, neurologic morbidity was 7% but with permanent sequelae in 1.39% of cases. Recurrence of stenosis was detected in 0.8% of patients but there were no cases of postoperative thrombosis. Indications for surgery were based on the existence of hemispheric ischemic accidents corresponding to the territory supplied by the artery operated upon, and on anatomic and evolutive arguments drawn from results of non-invasive review examinations: ultrasonography and Doppler. Results obtained: 81.9% of patients were asymptomatic after 30 months, appear to be superior to those of the natural history of carotid artery lesions.

  4. Comparative Review of the Treatment Methodologies of Carotid Stenosis

    PubMed Central

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

    2015-01-01

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

  5. A big floating thrombus in the common carotid artery.

    PubMed

    La Spada, Michele; Stilo, Francesco; Barillà, David; Spinelli, Francesco

    2011-11-01

    The management of the free-floating thrombus (FFT) is difficult, and it is unclear whether surgical or medical treatment is superior. The common carotid artery is rarely involved. An 80-year-old woman presented with right hand weakness and syncope. Ultrasound showed the presence of FFT in the left common carotid artery. A carotid endarterectomy with Dacron patch angioplasty was immediately performed without complications. In the presence of symptoms, the interventional management of FFT is advised.

  6. Endovascular Treatment of Extracranial Internal Carotid Aneurysms Using Endografts

    SciTech Connect

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

    2008-03-15

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

  7. Carotid artery access for transcatheter aortic valve replacement.

    PubMed

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

    2013-10-01

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

  8. Acute carotid baroreflex resetting in conscious dogs.

    PubMed Central

    Tan, W; Zucker, I H

    1989-01-01

    1. Acute baroreflex resetting in the control of arterial pressure was studied in six chronically instrumented, conscious dogs. Following aortic baroreceptor denervation, the carotid sinuses were surgically prepared for reversible vascular isolation. 2. During the experiments both carotid sinuses were temporarily isolated from the systemic circulation and conditioned with a pulsatile pressure. The carotid sinus conditioning pressure (CPCSP) was at a level of 100, 140 or 60 mmHg for 20 min each. Carotid sinus pressure (CSP) versus mean arterial pressure (MAP) baroreflex curves were constructed after each conditioning period. 3. The baroreflex curves were shifted downward and to the left at low CPCSP and upward and to the right at high CPCSP. 4. We used four parameters to quantify baroreflex resetting. These were: (1) the set point pressure (PSP), (2) the threshold pressure (PTh), (3) BP50 or mid-point pressure and (4) the CSP at maximum gain (PGmax). At high CPCSP, these four parameters were increased by 18.5 +/- 4.0, 23.4 +/- 4.3, 21.7 +/- 5.0 and 22.0 +/- 5.1 mmHg, respectively (P less than 0.05). 5. Resetting was not complete in these studies. The extent of resetting was approximately 50% for upward and 35% for downward baroreflex conditioning. 6. Analysis of the present experimental data indicates that when the cardiovascular system is exposed to a short-term hyper- or hypotension, the baroreflex is capable of correcting the baseline arterial pressure while preserving its ability to buffer transient disturbances as a result of partial resetting. PMID:2607463

  9. Management of infected carotid artery rupture.

    PubMed

    Liu, Jie; Zeng, Quan; Huang, Jiang-Ju; Hu, Guo-Hua

    2014-06-01

    Carotid artery rupture (CAR) is a life-threatening complication of head and neck cancer, and infection complicates its management. The purpose of this study was to review our experience with the treatment of infected CAR and to summarize the existing literature on this topic. We retrospectively reviewed the medical records of patients treated in our department from 2000 to 2011 and re-analyzed cases reported in the literature during the same time period. We analyzed etiology, anatomic location, treatment, and rates of recurrent hemorrhage for each case. A total of 46 episodes of infected CAR occurred in the four patients in our own records and 27 patients described in the literature. Twenty-eight patients suffered from various head and neck cancers and underwent surgical resection, and 27 of them subsequently received radiotherapy or radiotherapy combined with chemotherapy (the 28th patient died before radiotherapy due to severe blood loss). The most common site of bleeding was the common carotid artery (33/46, 71.7%). Seventeen cases (17/45, 37.8%) were treated with surgical ligation, 20 (44.4%) with stent placement, and 7 (15.6%) with embolization. Surgical ligation had a lower rate of recurrent bleeding (2/17, 11.8%) than stent placement (12/20, 60.0%) when used for the treatment of infected CAR (P = 0.037, Chi squared test). Our results suggest that surgical ligation is an effective option in the management of infected CAR and may be the best choice to prevent recurrent hemorrhage. The complication rates, however, may be high when the common carotid or the internal carotid arteries are ligated.

  10. 3D carotid plaque MR Imaging

    PubMed Central

    Parker, Dennis L.

    2015-01-01

    SYNOPSIS There has been significant progress made in 3D carotid plaque magnetic resonance imaging techniques in recent years. 3D plaque imaging clearly represents the future in clinical use. With effective flow suppression techniques, choices of different contrast weighting acquisitions, and time-efficient imaging approaches, 3D plaque imaging offers flexible imaging plane and view angle analysis, large coverage, multi-vascular beds capability, and even can be used in fast screening. PMID:26610656

  11. 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.

  12. Aterofisiol® in carotid plaque evolution

    PubMed Central

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

    2015-01-01

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

  13. Carotid Endarterectomy: Current Concepts and Practice Patterns

    PubMed Central

    Saha, Sibu P.; Saha, Subhajit; Vyas, Krishna S.

    2015-01-01

    Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon. PMID:26417192

  14. [Morbidity and mortality of carotid endarterectomy].

    PubMed

    Rodríguez Pérez, A; Cabrera Morán, V; Abad Vázquez, C; Muñoz Falcón, L; Hernández Ruiz, A; Hermida Anllo, M; Cárdenes Romero, I

    1993-01-01

    In order to investigate the peroperative complications in carotid surgery, a cohort of 64 patients operated of carotid endarterectomy (EC) were evaluated. A total 78 EC were performed, 56 unilateral (EC-U) and 11 bilateral (EC-B). All the cases were managed in a similar manner regarding surgical technique, monitoring, anesthetic management and pre and postoperative care. A temporary shunt was inserted in 6 cases. The hospital mortality has been 0. We registered the following postoperative complications: arterial hypertension in 23.1 of EC-U and 18.2% of EC-B, cervical hematoma in 5.3% (EC-U) and 13.6% (EC-B), TIA in 5.3% (EC-U) and 4.5% (EC-B), stroke 1.7% (EC-U) and 4.5% (EC-B), vocal cord injury in 3.5% of EC-U and chest pain with angina in 1.7% of EC-U. A review of the mortality and morbidity in carotid surgery is done.

  15. [Eversion carotid endarterectomy: advantages and disadvantages].

    PubMed

    Kazanchian, P O; Popov, V A; Rudakova, T V; Gaponova, E N

    1998-01-01

    A comparative analysis of results of 70 operations fulfilled by the method of classical with autovein plasty of the internal carotid artery (ICA) and of 103 operations by the method of eversion carotid endarterectomy (CEAE) was made. The time of compression of the carotid artery during the eversion CEAE proved to be considerably less (22.5 +/- 6.5) min, than when using the "classical" method (32.5 +/- 5.3) min. In the nearest postoperative period no neurological complications of embologenic genesis or those associated with acute thrombosis of ICA after the eversion CEAE were noted while after the "classical" method they developed in 3 patients and 2 of them died. After the eversion CEAE 1 patients died of myocardial infarction. In remote periods after the "classical" CEAE the restenosis and reocclusions appeared in 6 patients, while after the eversion method--in 3 patients. CEAE fulfilled by the eversion technique is an effective operation reducing the amount of postoperative neurological complications as well as of late restenosis and reocclusions. It can be used without the applying of the internal bypass.

  16. Atypical Arteritis in Internal Carotid Arteries: A Novel Concept of Isolated Internal Carotid Arteritis

    PubMed Central

    Fukuma, Kazuki; Kowa, Hisanori; Nakayasu, Hiroyuki; Nakashima, Kenji

    2016-01-01

    We presented a 38-year-old woman suffering from acute cerebral infarction due to arteritis limited to bilateral internal carotid arteries without a condition of giant cell arteritis or granulomatosis with polyangitis. Our case is unprecedented and characterized by a young woman with wall enhancement in the internal carotid arteries on contrast-enhanced magnetic resonance imaging (MRI), therapeutic effects of steroids, and positive status for human leucocyte antigen-B39, -B51 and -DR4. These disease characteristics were not in accordance with existing diagnostic criteria of vasculitis, such as Takayasu’s arteritis, giant cell arteritis, granulomatosis with polyangiitis, and Behcet’s disease. We suggested consideration of a novel “isolated internal carotid arteritis” disease concept. PMID:27708542

  17. The first derivative of the carotid displacement pulse.

    NASA Technical Reports Server (NTRS)

    Khan, A. H.; Spodick, D. H.

    1972-01-01

    The amplitude and time relationships of the carotid derivative in normal individuals and unselected cardiac patients is investigated together with the effects of different contraction strengths in patients with pulsus alternans and subjects challenged with isoproterenol and propranolol. Data regarding the relationship between the preejection period (PEP) and the ratio of peak to total amplitude of the carotid displacement pulse derivative are presented. It is found that cardiac abnormality tends to reduce the rate of rise of the carotid displacement pulse. The results obtained show that the PEP is a somewhat more sensitive index of the changes studied than the carotid displacement derivative.

  18. Cutpoints for screening blood glucose concentrations in healthy senior cats.

    PubMed

    Reeve-Johnson, Mia K; Rand, Jacquie S; Vankan, Dianne; Anderson, Stephen T; Marshall, Rhett; Morton, John M

    2017-02-01

    Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18-24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

  19. Measurement of regional cerebral blood flow in cat brain using intracarotid 2H2O and 2H NMR imaging

    SciTech Connect

    Detre, J.A.; Subramanian, V.H.; Mitchell, M.D.; Smith, D.S.; Kobayashi, A.; Zaman, A.; Leigh, J.S. Jr. )

    1990-05-01

    Cerebral blood flow (CBF) was measured in cat brain in vivo at 2.7 T using 2H NMR to monitor the washout of deuterated saline injected into both carotid arteries via the lingual arteries. In anesthetized cats, global CBF varied directly with PaCO{sub 2} over a range of 20-50 mm Hg, and the corresponding global CBF values ranged from 25 to 125 ml.100 g-1.min-1. Regional CBF was measured in a 1-cm axial section of cat brain using intracarotid deuterated saline and gradient-echo 2H NMR imaging. Blood flow images with a maximum pixel resolution of 0.3 x 0.3 x 1.0 cm were generated from the deuterium signal washout at each pixel. Image derived values for CBF agreed well with other determinations, and decreased significantly with hypocapnia.

  20. Numerical analysis of 3D blood flow and common carotid artery hemodynamics in the carotid artery bifurcation with stenosis.

    PubMed

    Antonova, N; Dong, X; Tosheva, P; Kaliviotis, E; Velcheva, I

    2014-01-01

    The results for blood flow in the carotid artery bifurcation on the basis of numerical simulation of Navier-Stokes equations are presented in this study. Four cases of carotid bifurcation are considered: common carotid artery (CCA) bifurcation without stenoses and cases with one, two and three stenoses are also presented. The results are obtained by performing numerical simulations considering one pulse wave period based on the finite volume discretization of Navier-Stokes equations. The structures of the flow around the bifurcation are obtained and the deformation of the pulse wave from common carotid artery (CCA) to the internal carotid artery (ICA) and external carotid artery (ECA) is traced. The axial velocity and wall shear stress (WSS) distribution and contours are presented considering the characteristic time points. The results of the WSS distribution around the bifurcation allow a prediction of the probable sites of stenosis growth.

  1. Junctional Internal Carotid Artery Aneurysms: The Schrödinger's Cat of Vascular Neurosurgery.

    PubMed

    Carlson, Andrew P; Loveren, Harry R van; Youssef, A Samy; Agazzi, Siviero

    2015-03-01

    Objectives Despite advances in neuroimaging, it is not always definitive whether a paraclinoid aneurysm is intradural or entirely extradural. We illustrate the potential use of surgical exploration in these aneurysms that we refer to as "junctional" aneurysms. Methods Retrospective review of eight patients with unruptured aneurysms who underwent a planned surgical exploration of a junctional aneurysm. Results Of the eight patients, three underwent exploration of the aneurysm during surgery for a different aneurysm. All three of these were found to be extradural. Five patients underwent a craniotomy for the exclusive purpose of clarifying the location of the aneurysm. Two of these cases were found to be intradural and were clipped. Two cases were found to be extradural. In one patient, the initially extradural aneurysm was converted into an intradural aneurysm during removal of the anterior clinoid process, necessitating surgical clipping. One transient third nerve palsy was observed. Discussion Until further progress in neuroimaging allows clinicians to determine unequivocally the exact anatomical location of a paraclinoid aneurysm, we advocate the use of the term junctional aneurysm to reflect the clinical uncertainty inherent in management decisions made regarding these aneurysms. We have illustrated a strategy of surgical exploration in select patients.

  2. Junctional Internal Carotid Artery Aneurysms: The Schrödinger's Cat of Vascular Neurosurgery

    PubMed Central

    Carlson, Andrew P.; Loveren, Harry R. van; Youssef, A. Samy; Agazzi, Siviero

    2014-01-01

    Objectives Despite advances in neuroimaging, it is not always definitive whether a paraclinoid aneurysm is intradural or entirely extradural. We illustrate the potential use of surgical exploration in these aneurysms that we refer to as “junctional” aneurysms. Methods Retrospective review of eight patients with unruptured aneurysms who underwent a planned surgical exploration of a junctional aneurysm. Results Of the eight patients, three underwent exploration of the aneurysm during surgery for a different aneurysm. All three of these were found to be extradural. Five patients underwent a craniotomy for the exclusive purpose of clarifying the location of the aneurysm. Two of these cases were found to be intradural and were clipped. Two cases were found to be extradural. In one patient, the initially extradural aneurysm was converted into an intradural aneurysm during removal of the anterior clinoid process, necessitating surgical clipping. One transient third nerve palsy was observed. Discussion Until further progress in neuroimaging allows clinicians to determine unequivocally the exact anatomical location of a paraclinoid aneurysm, we advocate the use of the term junctional aneurysm to reflect the clinical uncertainty inherent in management decisions made regarding these aneurysms. We have illustrated a strategy of surgical exploration in select patients. PMID:25844299

  3. Carotid-cardiac baroreflex response and LBNP tolerance following resistance training

    NASA Technical Reports Server (NTRS)

    Tatro, D. L.; Dudley, G. A.; Convertino, V. A.

    1992-01-01

    The purpose of this study was to examine the effect of lower body resistance training on cardiovascular control mechanisms and blood pressure maintenance during an orthostatic challenge. Lower body negative pressure (LBNP) tolerance, carotid-cardiac baroreflex function (using neck chamber pressure), and calf compliance were measured in eight healthy males before and after 19 wk of knee extension and leg press training. Resistance training sessions consisted of four or five sets of 6-12 repetitions of each exercise, performed two times per week. Training increased strength 25 +/- 3 (SE) percent (P = 0.0003) and 31 +/- 6 percent (P = 0.0004), respectively, for the leg press and knee extension exercises. Average fiber size in biopsy samples of m. vastus lateralis increased 21 +/- 5 percent (P = 0.0014). Resistance training had no significant effect on LBNP tolerance. However, calf compliance decreased in five of the seven subjects measured, with the group average changing from 4.4 +/- 0.6 ml.mm Hg-1 to 3.9 +/- 0.3 ml.mm Hg-1 (P = 0.3826). The stimulus-response relationship of the carotid-cardiac baroreflex response shifted to the left on the carotid pressure axis as indicated by a reduction of 6 mm Hg in baseline systolic blood pressure (P = 0.0471). In addition, maximum slope increased from 5.4 +/- 1.3 ms.mm Hg-1 before training to 6.6 +/- 1.6 ms.mm Hg-1 after training (P = 0.0141). Our results suggest the possibility that high resistance, lower extremity exercise training can cause a chronic increase in sensitivity and resetting of the carotid-cardiac baroreflex.

  4. Interaction of semicircular canal stimulation with carotid baroreceptor reflex control of heart rate

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    The carotid-cardiac baroreflex contributes to the prediction of orthostatic tolerance; experimental attenuation of the reflex response leads to orthostatic hypotension in humans and animals. Anecdotal observations indicate that rotational head movements about the vertical axis of the body can also induce orthostatic bradycardia and hypotension through increased parasympathetic activity. We therefore measured the chronotropic response to carotid baroreceptor stimulation in 12 men during varying conditions of vestibulo-oculomotor stimulation to test the hypothesis that stimulation of the semicircular canals associated with head movements in the yaw plane inhibits cardioacceleration through a vagally mediated baroreflex. Carotid-cardiac baroreflex response was assessed by plotting R-R intervals (ms) at each of 8 neck pressure steps with their respective carotid distending pressures (mmHg). Calculated baroreflex gain (maximal slope of the stimulus-response relationship) was measured under 4 experimental conditions: 1) sinusoidal whole-body yaw rotation of the subject in the dark without visual fixation (combined vestibular-oculomotor stimulation); 2) yaw oscillation of the subject while tracking a small head-fixed light moving with the subject (vestibular stimulation without eye movements); 3) subject stationary while fixating on a small light oscillating in yaw at the same frequency, peak acceleration, and velocity as the chair (eye movements without vestibular stimulation); and 4) subject stationary in the dark (no eye or head motion). Head motion alone and with eye movement reduced baseline baroreflex responsiveness to the same stimulus by 30%. Inhibition of cardioacceleration during rotational head movements may have significant impact on functional performance in aerospace environments, particularly in high-performance aircraft pilots during high angular acceleration in aerial combat maneuvers or in astronauts upon return from spaceflight who already have

  5. Pemphigus foliaceus in a cat.

    PubMed

    Kofod, H

    1993-01-16

    The author's cat started to develop the signs of pemphigus foliaceus one month after he returned home after six months absence. The initial signs included dry coughing and difficulty with purring and swallowing, followed by typical changes of the skin. The cat was treated by a combination of chrysotherapy and systemic glucocorticoid injections, and remained free of clinical signs for one and a half years. The cat then relapsed and showed the initial signs except that coughing was not observed. It was treated as before but after a second relapse and the same treatment it slowly developed a general weakness and was euthanased.

  6. Serum calcium level is related to both intima-media thickness and carotid atherosclerosis: a neglect risk factor in obese/overweight subjects

    PubMed Central

    2012-01-01

    Background Experimental studies suggested that high serum calcium may be important in the pathogenesis of vascular diseases. Since calcium seems to affect specifically the cerebrovascular district, aim of this study was to determine the relation between serum calcium levels, within normal range, and subclinical atherosclerosis in the carotid arteries, in a population of obese/overweight subjects. Methods In our retrospective study we included 472 subjects (59% female) with body mass index equal to or more than 25 kg/m2. They underwent a physical examination, a biochemical assessment (including calcium evaluation) and a B-mode ultrasonography of the extracranial carotid arteries to detect carotid atherosclerosis presence and to measure intima-media thickness. Results Mean age of the population was 50 ±12 years. Prevalence of the Carotid atherosclerosis was 40%. Mean carotid intima-media thickness was 0,66 ± 0,18 mm. The univariate and multivariate analysis showed an association between calcium and carotid intima-media thickness (p = 0,035). We divided the population in serum calcium tertiles. We found an higher carotid atherosclerosis prevalence in the III tertile in comparison to that of the I tertile (p = 0,039). Conclusions In this study we found a positive relation between serum calcium levels, within normal range, and subclinical atherosclerosis in the carotid arteries, in a population of obese/overweight subjects. It is important to consider the impact of the serum calcium levels in the overall risk assessment of patients, at least in obese subjects. PMID:22672668

  7. Cytologic findings, and feline herpesvirus DNA and Chlamydophila felis antigen detection rates in normal cats and cats with conjunctival and corneal lesions.

    PubMed

    Volopich, Sabine; Benetka, Viviane; Schwendenwein, Ilse; Möstl, Karin; Sommerfeld-Stur, Irene; Nell, Barbara

    2005-01-01

    Samples were collected from 36 cats with feline herpesvirus (FHV-1)-related ocular disease (conjunctivitis, epithelial or stromal keratitis, or corneal sequestration), and 17 cats without ocular changes. Corneoconjunctival swabs, scrapings and biopsies were tested in various combinations for presence of FHV-1 DNA using single round (sr) polymerase chain reaction (PCR) and nested PCR (nPCR). Additional swabs from the inferior conjunctival fornix were tested by enzyme-linked immunosorbent assay for Chlamydophila felis antigen. Cytologic evaluation was carried out on conjunctival (cats with conjunctivitis) and corneal (cats with keratitis) cytobrush preparations. FHV-1 DNA was detected by PCR in 14 (39%) cats with ocular disease and 1 (6%) of the control group. Agreement between srPCR and nPCR results was significant (P < 0.01). FHV-1 DNA was detected in 3/7 cats with conjunctivitis, 5/6 cats with epithelial keratitis, 3/11 cats with stromal keratitis, and 3/12 cats with corneal sequestration. There was a significant association (P = 0.0027) between viral presence and epithelial keratitis. However, no significant association was found between viral presence and conjunctivitis (P = 0.059), stromal keratitis (P = 0.15), or corneal sequestration (P = 0.18). With respect to FHV-1 DNA detection, intersample agreement was significant (P < 0.03). No sampling technique seemed more likely than another to harvest detectable viral DNA, except for cats with corneal sequestrum in which viral DNA was not detected using corneoconjunctival swabs. FHV-1 DNA was detected in 6/9 samples with intranuclear inclusion bodies and in 6/7 cats with eosinophils on cytologic examination. All samples tested negative for C. felis antigen.

  8. Nuclear magnetic resonance-determined lipoprotein subclasses and carotid intima-media thickness in type 1 diabetes

    PubMed Central

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

    2015-01-01

    Background Dyslipidemia has been linked to vascular complications of Type 1 diabetes (T1DM). We investigated the prospective associations of nuclear magnetic resonance-determined lipoprotein subclass profiles (NMR-LSP) and conventional lipid profiles with carotid intima-media thickness (IMT) in T1DM. Methods NMR-LSP and conventional lipids were measured in a subset of Diabetes Control and Complications Trial (DCCT) participants (n=455) at study entry (‘baseline’, 1983–89), and were related to 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 12 (2004–2006). Associations were defined using multiple linear regression stratified by gender, and following adjustment for HbA1c, diabetes duration, body mass index, albuminuria, DCCT randomization group, smoking status, statin use, and ultrasound devices. Results In men, significant positive associations were observed between some baseline NMR-subclasses of LDL (total IDL/LDL and large LDL) and common and/or internal carotid IMT, and between conventional total- and LDL-cholesterol and non-HDL-cholesterol and common carotid IMT, at EDIC Year 12; these persisted in adjusted analyses (p<0.05). Large LDL particles and conventional triglycerides were positively associated with common carotid IMT changes over 12 years (p<0.05). Inverse associations of mean HDL diameter and large HDL concentrations, and positive associations of small LDL with common and/or internal carotid IMT (all p<0.05) were found, but did not persist in adjusted analyses. No significant associations were observed in women. Conclusion NMR-LSP-derived LDL particles, in addition to conventional lipid profiles, may help in identifying men with T1DM at highest risk for vascular disease. PMID:26600440

  9. [Prevalence of Tritrichomonas foetus among Dutch cats].

    PubMed

    van Doorn, D C K; de Bruin, M J; Jorritsma, R A; Ploeger, H W; Schoormans, A

    2009-09-01

    Prevalence of Tritrichomonas foetus among Dutch cats The aim of this study was to determine the prevalence of and risk factors for, Tritrichomonas foetus among cats in the Netherlands. A total of 154 faecal samples were collected from three groups of cats: cats with diarrhoea (n=53), cattery cats (n=47), and healthy pet cats (n=54). Faecal samples were examined with a T. foetus specific real-time PCR. All PCR-positive samples were run on gel electrophoresis for definitive diagnosis. The prevalence of T. foetus was 2% among cats with diarrhoea and 4% among cattery cats; T. foetus was not prevalent among pet cats (none of the samples tested positive). Questionnaires had been distributed to cat and cattery owners to determine risk factors for T. foetus, but the low prevalence precluded statistical analysis of the questionnaire results.

  10. High prevalence of helminth parasites in feral cats in Majorca Island (Spain).

    PubMed

    Millán, Javier; Casanova, Joan Carles

    2009-12-01

    Feral cats are widespread in the countryside of Majorca (Balearic Islands, Spain). Since they are not subject of sanitary control, they can act as reservoir of parasites of veterinary and zoonotic interest. The main organs of 58 wild-trapped cats in 16 different areas from Majorca were analyzed by helminths. All the cats were parasitized, and eight species of helminths were retrieved (mean = 3.4 species per cat, with 74% of the cats harboring three or more species). Seven of them presented a prevalence >20%: Joyeuxiella pasqualei (76%), Diplopylidium acanthotetra (60%), Dipylidium carracidoi (33%), Taenia taeniaeformis (22%), Ancylostoma tubaeforme (91%), and Toxocara cati (35%) in the gastrointestinal tract, and Oslerus rostratus (24%) in lungs. The A. tubaeforme prevalence and intensity (mean = 30, up to 396) is the highest recorded for a population of cats. Prevalence and abundance of J. pasqualei and D. acanthotetra were strongly associated, secondary to the use of the same intermediary host (geckos). Other positive associations found are probably related to host susceptibility. Abundance of D. acanthotetra, T. cati, and A. tubaeforme and the number of species per host were negatively correlated with cat body condition (assessed by the kidney fat index). Females were more frequently parasitized by A. tubaeforme than males, and adult females were more heavily infested by J. pasqualei and D. acanthotetra than cats from other groups. These and other findings are discussed in relation with host ecology. Feral cats serve as reservoirs of helminths in the countryside of Majorca and their populations should be controlled.

  11. Cat eye syndrome

    PubMed Central

    Sharma, Deepak; Murki, Srinivas; Pratap, Tejo; Vasikarla, Madhavi

    2014-01-01

    A full-term female baby, a product of non-consanguineous marriage, was born at 37 weeks of gestation with a birth weight of 2.08 kg. Antenatal scan at 31 weeks revealed complex congenital heart disease with a hypoplastic right ventricle, pulmonary atresia and an intact septum. Immediately after birth, the infant was shifted to the nursery and was started on intravenous fluids and infusion prostaglandin E1 (Alprostidil). On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. Postnatal echocardiography confirmed a large ostium secundum atrial septal defect with left to right shunt, right ventricle hypoplasia, pulmonary atresia with an intact septum and a large vertical patent ductus arteriosus. Ophthalmological examination showed a bilateral chorioretinal coloboma sparing disc and fovea. Karyotyping showed an extra small marker chromosome suggestive of the Cat eye syndrome. PMID:24842361

  12. Cat eye syndrome.

    PubMed

    Sharma, Deepak; Murki, Srinivas; Pratap, Tejo; Vasikarla, Madhavi

    2014-05-19

    A full-term female baby, a product of non-consanguineous marriage, was born at 37 weeks of gestation with a birth weight of 2.08 kg. Antenatal scan at 31 weeks revealed complex congenital heart disease with a hypoplastic right ventricle, pulmonary atresia and an intact septum. Immediately after birth, the infant was shifted to the nursery and was started on intravenous fluids and infusion prostaglandin E1 (Alprostidil). On examination, she had microcephaly, periorbital puffiness, a long philtrum, a broad nasal bridge and retrognathia, up slanting palpebral fissures, widely spaced nipples, a sacral dimple and right upper limb postaxial polydactyly. Postnatal echocardiography confirmed a large ostium secundum atrial septal defect with left to right shunt, right ventricle hypoplasia, pulmonary atresia with an intact septum and a large vertical patent ductus arteriosus. Ophthalmological examination showed a bilateral chorioretinal coloboma sparing disc and fovea. Karyotyping showed an extra small marker chromosome suggestive of the Cat eye syndrome.

  13. Coding Microsatellite Frameshift Mutations Accumulate in Atherosclerotic Carotid Artery Lesions: Evaluation of 26 Cases and Literature Review.

    PubMed

    Kurz, Carolin; Hakimi, Maani; Kloor, Matthias; Grond-Ginsbach, Caspar; Gross-Weissmann, Marie-Luise; Böckler, Dittmar; von Knebel Doeberitz, Magnus; Dihlmann, Susanne

    2015-06-09

    Somatic DNA alterations are known to occur in atherosclerotic carotid artery lesions; however, their significance is unknown. The accumulation of microsatellite mutations in coding DNA regions may reflect a deficiency of the DNA mismatch repair (MMR) system. Alternatively, accumulation of these coding microsatellite mutations may indicate that they contribute to the pathology. To discriminate between these two possibilities, we compared the mutation frequencies in coding microsatellites (likely functionally relevant) with those in noncoding microsatellites (likely neutral). Genomic DNA was isolated from carotid endarterectomy (CEA) specimens of 26 patients undergoing carotid surgery and from 15 nonatherosclerotic control arteries. Samples were analyzed by DNA fragment analysis for instability at three noncoding (BAT25, BAT26, CAT25) and five coding (AIM2, ACVR2, BAX, CASP5, TGFBR2) microsatellite loci, with proven validity for detection of microsatellite instability in neoplasms. We found an increased frequency of coding microsatellite mutations in CEA specimens compared with control specimens (34.6 versus 0%; p = 0.0013). Five CEA specimens exhibited more than one frameshift mutation, and ACVR2 and CASP5 were affected most frequently (5/26 and 6/26). Moreover, the rate of coding microsatellite alterations (15/130) differed significantly from that of noncoding alterations (0/78) in CEA specimens (p = 0.0013). In control arteries, no microsatellite alterations were observed, neither in coding nor in noncoding microsatellite loci. In conclusion, the specific accumulation of coding mutations suggests that these mutations play a role in the pathogenesis of atherosclerotic carotid lesions, since the absence of mutations in noncoding microsatellites argues against general microsatellite instability, reflecting MMR deficiency.

  14. Ischemic postconditioning alleviates neuronal injury caused by relief of carotid stenosis in a rat model of cerebral hypoperfusion.

    PubMed

    Feng, Chunsheng; Luo, Tianfei; Qi, Li; Wang, Boyu; Luo, Yinan; Ge, Pengfei

    2012-10-18

    The effects of early relief of heavy bilateral carotid stenosis and ischemic postconditioning on hippocampus CA1 neurons are still unclear. In this study, we used a rat model to imitate severe bilateral carotid stenosis in humans. The rats were divided into sham group, carotid stenosis group, stenosis relief group and ischemic postconditioning group. Ischemic postconditioning consisted of three cycles of 30 s ischemia and 30 s reperfusion. The cerebral blood flow was measured with a laser Doppler flowmeter. Neuronal death in the CA1 region was observed by hematoxylin-eosin staining, and the number of live neurons was assessed by cell counting under a light microscope. The levels of oxidative products MDA and 8-iso-PGF2α, inflammatory factors IL-1β and TNF-α, and the activities of anti-oxidative enzymes SOD and CAT were assayed by specific enzyme-linked immunosorbent assay (ELISA) kits, respectively. We found that relief of carotid stenosis and ischemic postconditioning could increase cerebral blood flow. When stenosis was relieved, the percentage of live neurons was 66.6% ± 6.2% on day 3 and 62.3% ± 9.8% on day 27, which was significantly higher than 55.5% ± 4.8% in stenosis group. Ischemic postconditioning markedly improved the live neurons to 92.5% ± 6.7% on day 3 and 88.6% ± 9.1% on day 27. Further study showed that, neuronal death caused by relief of stenosis is associated with increased oxidative stress and enhanced inflammatory response, and the protection of ischemic postconditioning is related to inhibition of oxidative stress and suppression of inflammatory response.

  15. The effects of stimulating carotid chemoreceptors on renal haemodynamics and function in dogs.

    PubMed Central

    Karim, F; Poucher, S M; Summerill, R A

    1987-01-01

    1. Dogs were anaesthetized with chloralose and artificially ventilated. The carotid chemoreceptors were stimulated by changing the perfusion of vascularly isolated carotid sinus regions from arterial to venous blood. The mean carotid sinus pressure and the mean arterial blood pressure were held constant at 124 +/- 3 and 122 +/- 3 mmHg, respectively. Both vagosympathetic trunks were sectioned in the neck and propranolol (17 micrograms kg-1 min-1 I.V.) and gallamine triethiodide (0.2-2.0 mg kg-1 30 min-1 I.V.) were infused. Renal blood flow was measured by an electromagnetic flow probe, glomerular filtration rate by creatinine clearance, sodium excretion by flame photometry and solute excretion by osmometry. 2. In sixteen tests in thirteen dogs perfusion of the carotid sinus regions with venous blood resulted in significant decreases in renal blood flow from 271 +/- 24 to 198 +/- 21 ml min-1 100 g-1 renal mass; glomerular filtration rate from 41.0 +/- 4.8 to 22.1 +/- 3.1 ml min-1 100 g-1; filtration fraction from 0.25 +/- 0.02 to 0.19 +/- 0.02; urine flow from 0.48 +/- 1.0 to 0.21 +/- 0.03 ml min-1 100 g-1; sodium excretion from 18.1 +/- 4.1 to 12.9 +/- 4.2 mumol min-1 100 g-1; and osmolar excretion 327 +/- 42 to 171 +/- 26 mu osmol min-1 100 g-1. The right atrial pressure did not change significantly from 4.6 +/- 1.2 cmH2O. 3. In seven dogs, tying renal sympathetic nerves abolished all the responses except that of sodium excretion which was now reversed; sodium excretion increased from 68 +/- 19 to 116 +/- 38 mumol min-1 100 g-1 without significant change in right atrial pressure from 7.4 +/- 1.9 cmH2O. Crushing the carotid bodies, however, abolished all the responses. 4. The results show that carotid chemoreceptor stimulation can cause significant reflex effects on renal haemodynamics and function which are mediated via renal sympathetic nerves. They also show that the chemoreceptor stimulation can cause natriuresis in the absence of haemodynamic changes, in the

  16. Prevalence and determinants of carotid plaque in the cross-sectional REFINE-Reykjavik study

    PubMed Central

    Sturlaugsdottir, Ran; Aspelund, Thor; Bjornsdottir, Gudlaug; Sigurdsson, Sigurdur; Thorsson, Bolli; Eiriksdottir, Gudny; Gudnason, Vilmundur

    2016-01-01

    Objective Carotid plaque and intima-media thickness are non-invasive arterial markers that are used as surrogate end points for cardiovascular disease. The aim was to assess the prevalence and severity of carotid plaque, and examine its determinant risk factors and their association to the common carotid artery intima-media thickness (CCA-IMT) in a general population. Methods We examined 6524 participants aged 25–69 years in the population-based REFINE (Risk Evaluation For INfarct Estimates)-Reykjavik study. Plaques at the bifurcation and internal carotid arteries were evaluated. Mean CCA-IMT was measured in the near and far walls of the common carotid arteries. Results The prevalence of minimal, moderate and severe plaque was 35.0%, 8.9% and 1.1%, respectively, and the mean CCA-IMT was 0.73 (SD 0.14) mm. Age, sex, smoking and type 2 diabetes mellitus (T2DM) were the strongest risk factors associated with plaque, followed by systolic blood pressure, total cholesterol, body mass index and family history of myocardial infarct. Low educational level was also strongly and independently associated with plaque. CCA-IMT shared the same risk factors except for a non-significant association with T2DM and family history of myocardial infarction (MI). Participants with T2DM had greater plaque prevalence, 2-fold higher in those <50 years and 17–30% greater in age groups 50–54 to 60–64, and more significant plaques (moderate or severe) were the difference in prevalence was 24% in age group 50–54 and ≥60% in older age groups, compared with non-T2DM. Conclusions Carotid plaque and CCA-IMT have mostly common determinants. However, T2DM and family history of MI were associated with plaque but not with CCA-IMT. Greater prevalence and more severe plaques in individuals with T2DM raise the concern that with increasing prevalence of T2DM we may expect an increase in atherosclerosis and its consequences. PMID:27884845

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

    PubMed

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

    2015-01-01

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

  18. Congenital horner syndrome and hemiplegia secondary to carotid dissection.

    PubMed

    Gupta, Mohit; Dinakaran, Subramanian; Chan, Tan K

    2005-01-01

    A 5-month-old infant had right Horner syndrome and left hemiplegia. Magnetic resonance imaging confirmed smaller cerebral hemisphere and magnetic resonance angiography showed reduced blood flow in the internal carotid artery on the right. A diagnosis of congenital hemiplegia and carotid occlusion secondary to maternal trauma during pregnancy was made.

  19. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  20. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  1. 21 CFR 870.3850 - Carotid sinus nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carotid sinus nerve stimulator. 870.3850 Section 870.3850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3850 Carotid...

  2. Carotid baroreceptor-muscle sympathetic relation in humans.

    PubMed

    Rea, R F; Eckberg, D L

    1987-12-01

    The purpose of this study was to define the relation between carotid distending pressure and muscle sympathetic activity in humans. Carotid baroreceptors of nine healthy subjects were compressed or stretched for 5 s with graded neck pressure or suction (+40 to -65 mmHg), and muscle sympathetic nerve activity was recorded. The results delineate several features of human baroreflex function. First, the carotid-muscle sympathetic relation is well described by an inverse sigmoid function. Second, a linear relation exists between carotid distending pressure and sympathetic outflow over a range of approximately 25 mmHg. Third, sympathetic responses to changes of carotid pressures are asymmetric; increases of sympathetic activity during carotid compression are much greater than reductions of sympathetic activity during carotid stretch. Fourth, at rest, normal subjects operate near the threshold level for sympathetic excitation. Thus the carotid-muscle sympathetic baroreflex is poised to oppose reductions more effectively than elevations of arterial pressure, and the range of pressures over which the reflex is active is wider than thought hitherto.

  3. Survival of a feline isolate of Tritrichomonas foetus in water, cat urine, cat food and cat litter.

    PubMed

    Rosypal, Alexa C; Ripley, Allyson; Stockdale Walden, Heather D; Blagburn, Byron L; Grant, David C; Lindsay, David S

    2012-04-30

    Feline intestinal trichomoniasis caused by Tritrichomonas foetus is associated with large bowel diarrhea in cats from many parts of the world. It has long been recognized as an economically important sexually transmitted disease that causes early abortion in cattle. Isolates of T. foetus from cattle are infectious for the large intestine of cats and isolates of T. foetus from cats are infectious for the reproductive system of cattle. The parasite is maintained by fecal-oral transmission in cats. The present study was conducted to examine the survival of a feline isolate of T. foetus, AUTf-12, under various conditions that are relevant to fecal-oral transmission in cats. Trophozoites were grown in TYM medium and then exposed to water, cat urine, dry cat food, canned cat food, clumping cat litter, or filter paper for various lengths of time and then re-cultured in TYM medium. Trophozoites survived exposure to distilled or tap water for 30 but not 60 min, while they survived for at least 180 min in urine. Trophozoites survived for 30 min on dry cat food but survived for 120-180 min in canned cat food. No survival of trophozoites was observed on cat litter but trophozoites survived for 15 min when placed on filter paper. Our results indicate that T. foetus can survive and be potentially infectious in water, urine, dry cat food and canned cat food.

  4. [Effect of gamma-aminobutyric acid and phenibut on the central links of the vascular reflexes with chemo- and mechanoreceptors of the aorto-carotid zone].

    PubMed

    Kovalev, G V; Morozov, I S

    1975-04-01

    Experiments were conducted on decerebrated cats. A depressive effect of gamma-aminobutyruc acid (GABA)--100--200 mg/kg and its phenyl derivative phenibut--20 mg/kg--on depressive reactions of the systemic arterial pressure and on the inhibition of spontaneous bioelectrical activity in the renal nerve occurring in stimulation of the mechanoreceptors of the carotid sinus and of the sinus and depressor nerve afferents (having a mechanoreceptor modality) was demonstrated. Pressor reactions of the systemic arterial pressure and evoked bioelectrical activity were enhanced in the renal nerve in stimulation of chemoreceptors of the carotid sinus following administration of the same GABA and phenibut doses. The data obtained are interpreted from the aspect of a deprimating action of GABA and phenibut in the area of the paramedian reticular nuclei of the medulla oblongata.

  5. Relation between visceral fat and carotid intimal media thickness in Mexican postmenopausal women: a preliminary report

    PubMed Central

    Azpilcueta, Yessica Mireya Moreno; Ortiz, Sergio Rosales

    2016-01-01

    Aim of the study To investigate the relationship between visceral fat and carotid IMT (intima media thickness) in Mexican postmenopausal women. Material and methods In 71 postmenopausal women divided in two groups: group 1, IMT > 1 mm and group 2, IMT ≤ 1 mm, blood pressure, body mass index (BMI), waist hip ratio (WHR), visceral and subcutaneous fats and carotid IMT were analyzed. Descriptive statistics were used and the comparison among those with abnormal and normal IMT was carried out using Mann-Whitney U test; also Spearman's correlation analysis was done. Results When comparing group 1 (n = 9, 12.7%) with group 2 (n = 62, 87.3%), it was found that the subcutaneous fat, visceral fat and systolic blood pressure were significantly greater in group 1 (p < 0.018, p < 0.001 and p < 0.006, respectively), and also in this group there was a correlation between BMI and subcutaneous fat (ρ = 0.686, p < 0.041) and between visceral fat and the systolic blood pressure (ρ = 0.712, p < 0.031). In group 2, there was a correlation between IMT and diastolic blood pressure (ρ = 0.251, p < 0.049). Conclusion Subcutaneous and visceral fat have an unfavorable effect in the carotid IMT and in blood pressure. PMID:27582681

  6. Noncavernous arteriovenous shunts mimicking carotid cavernous fistulae

    PubMed Central

    Kobkitsuksakul, Chai; Jiarakongmun, Pakorn; Chanthanaphak, Ekachat; Singhara Na Ayudya, Sirintara (Pongpech)

    2016-01-01

    PURPOSE The classic symptoms and signs of carotid cavernous sinus fistula or cavernous sinus dural arteriovenous fistula (AVF) consist of eye redness, exophthalmos, and gaze abnormality. The angiography findings typically consist of arteriovenous shunt at cavernous sinus with ophthalmic venous drainage with or without cortical venous reflux. In rare circumstances, the shunts are localized outside the cavernous sinus, but mimic symptoms and radiography of the cavernous shunt. We would like to present the other locations of the arteriovenous shunt, which mimic the clinical presentation of carotid cavernous fistulae, and analyze venous drainages. METHODS We retrospectively examined the records of 350 patients who were given provisional diagnoses of carotid cavernous sinus fistulae or cavernous sinus dural AVF in the division of Interventional Neuroradiology, Ramathibodi Hospital, Bangkok between 2008 and 2014. Any patient with cavernous arteriovenous shunt was excluded. RESULTS Of those 350 patients, 10 patients (2.85%) were identified as having noncavernous sinus AVF. The angiographic diagnoses consisted of three anterior condylar (hypoglossal) dural AVF, two traumatic middle meningeal AVF, one lesser sphenoid wing dural AVF, one vertebro-vertebral fistula (VVF), one intraorbital AVF, one direct dural artery to cortical vein dural AVF, and one transverse-sigmoid dural AVF. Six cases (60%) were found to have venous efferent obstruction. CONCLUSION Arteriovenous shunts mimicking the cavernous AVF are rare, with a prevalence of only 2.85% in this series. The clinical presentation mainly depends on venous outflow. The venous outlet of the arteriovenous shunts is influenced by venous afferent-efferent patterns according to the venous anatomy of the central nervous system and the skull base, as well as by architectural disturbance, specifically, obstruction of the venous outflow. PMID:27767958

  7. Carotid artery disease after head and neck radiotherapy.

    PubMed

    Thalhammer, Christoph; Husmann, Marc; Glanzmann, Christoph; Studer, Gabriela; Amann-Vesti, Beatrice R

    2015-01-01

    Radiation induced atherosclerosis of the carotid artery is a clinically relevant late complication after head and neck radiotherapy. Improved long-term survival after multimodality therapy in neck malignancies result in an increased risk of carotid artery disease in patients after radiotherapy (RT). This review focuses on the current knowledge of occlusive carotid disease after head and neck radiotherapy and highlights the exceeding morphologic post-radiation vessel wall pathologies. More severe and extensive carotid artery atherosclerosis with plaque in all segments including the common carotid artery is a frequent finding after RT. Therefore, colour coded duplex ultrasound surveillance in patients after head and neck RT is recommended. Some histopathological studies indicate differences to “classical” atherosclerosis, and pathogenesis of chronic radiation vasculopathy is still under discussion.

  8. Mathematical model of carotid artery for stent placement

    NASA Astrophysics Data System (ADS)

    Rahman, Tengku Husna Tengku Abdul; Din, Ummul Khair Salma; Ahmad, Rokiah @ Rozita

    2016-11-01

    The carotid artery stenting is one of the methods used to reduce the effect of artherosclerosis which caused by the thickening of the artery wall. In most of the studies, the measure of wall elasticity, shear stress and the blood pressure through the blood flow were considered. The aim of this study is to determine the position to place the stent inside the carotid artery. A mathematical model is reconstructed to determine the suitable location of the stent in the carotid artery. Throughout the study, differences in fluid flow between a normal carotid artery wall and stenosed carotid artery wall are investigated. Since the existence of the stenosis provides a resistance in the flow, it is important to identify the right position to place the stent. The stent will be placed in the position where stenosis exists to ease the blood to flow normally. Later after the stent placement, the blood flow normally through the blood vessel.

  9. Dynamics of collateral circulation in progressive asymptomatic carotid disease.

    PubMed

    Moll, F L; Eikelboom, B C; Vermeulen, F E; van Lier, H J; Schulte, B P

    1986-03-01

    Inadequacy of collateral arterial flow is the major risk factor for hemispheric infarction in association with spontaneous occlusion of the ipsilateral carotid artery. This prospective study was designed to measure the adaptation of collateral cerebral circulation through the circle of Willis in patients in whom a unilateral carotid stenosis of hemodynamic consequence develops asymptomatically. The collateral cerebral potential is assessed by ocular pneumoplethysmography (OPG) during proximal common carotid artery compression, measuring the collateral ophthalmic artery pressure (COAP). During an average follow-up of almost 3 years (maximum more than 7 years), 45 patients showed asymptomatic development of a unilateral hemodynamically significant carotid stenosis according to OPG evidence. In these patients the mean index COAP/brachial artery pressure did not change on the side of stenosis progression (p greater than 0.05). The developed carotid stenosis had only reduced collateral circulation to the contralateral hemisphere. The risk of inadequate collateral cerebral circulation remained during progression of asymptomatic extracranial arterial obstructive disease.

  10. Bilateral atherosclerotic internal carotid artery occlusion and recurrent ischaemic stroke.

    PubMed

    Amin, Osama S M

    2015-06-08

    Bilateral internal carotid artery occlusion (BICAO) is a rare disease that carries a gloomy prognosis. We report a case of a 52-year-old man who developed ischaemic infarction at the region of the right middle cerebral artery; he was found to have atherosclerotic occlusion of both internal carotid arteries on Doppler-duplex examination. He received medical treatment only. After 1 year, he developed a new infarction at the region of the left middle cerebral artery. Conventional angiography revealed bilateral occlusion of internal carotid arteries at their origin, approximately 50% stenosis of the common carotid bulbs and mild stenosis of the origin of external carotid arteries. The patient did not undergo any form of surgical revascularisation procedures and died of severe aspiration pneumonia approximately 2 months after the second stroke. BICAO portends a poor outcome and carries a risk of recurrent ischaemic events. The best management strategy for this vascular occlusion remains unclear.

  11. The course of post-ganglionic sympathetic fibres distributed with the trigeminal nerve in the cat.

    PubMed Central

    Matthews, B; Robinson, P P

    1980-01-01

    1. The course of post-ganglionic sympathetic fibres to the jaws, face and eye was investigated in cats by observing the effects of nerve sections on responses evoked by stimulation of the cervical sympathetic trunk. 2. Sympathetic fibres were present in the infraorbital and inferior alveolar nerves. From the superior cervical ganglion, all of these fibres travelled in the internal carotid nerve and all but a few passed through the foramen lacerum and joined the trigeminal nerve at its ganglion. 3. Compound action potentials were recorded from sympathetic fibres in six out of twenty-seven teeth. These fibres followed the route described above. 4. Sympathetic fibres to the pupil and levator palpebrae superioris passed from the internal carotid nerve to the eye via the foramen lacerum and the superior orbital fissure. Some fibres causing piloerection in front of the ear travelled by the same route and some travelled with the maxillary division of the trigeminal nerve. 5. Sympathetic fibres to the nictitating membrane followed a similar route to those supplying the pupil except that they entered the cranial vault through the pterygoid foramen. 6. The secretomotor fibres to the submandibular salivary gland and some vasoconstrictor fibres to the lip did not travel with the internal carotid nerve or major branches of the trigeminal nerve. PMID:7431241

  12. Increased carotid intima media thickness is associated with prolactin levels in subjects with untreated prolactinoma: a pilot study.

    PubMed

    Jiang, Xiao-Bing; Li, Cui-Ling; He, Dong-Sheng; Mao, Zhi-Gang; Liu, Dong-Hong; Fan, Xiang; Hu, Bin; Zhu, Yong-Hong; Wang, Hai-Jun

    2014-06-01

    Hyperprolactinemia is associated with endothelial dysfunction and atherogenic risk factors, but carotid intima media thickness (IMT) has not been studied in hyperprolactinemic patients. To determine whether untreated hyperprolactinemia contributes to increased carotid IMT. Thirty-one prolactinoma patients and 60 healthy controls were respectively studied. Participants underwent hormone evaluation. Anthropometric parameters (body mass index and blood pressure), inflammatory markers (high-sensitivity C-reactive protein and fibrinogen), serum glucose, insulin, lipid and apolipoprotein profiles were also determined. Endothelial function measured as the flow-mediated dilation (FMD) of a brachial artery and carotid IMT were evaluated using high-resolution ultrasonography. Multivariate linear regression analysis was applied to identify independent determinants of FMD and carotid IMT. Triglycerides, homeostasis model assessment of insulin resistance, apolipoprotein (apo)B/apoA-I ratio, high-sensitivity C-reactive protein (hsCRP) and fibrinogen were significantly higher, while apoA-I was significantly lower in patients with prolactinomas than in the controls. Meanwhile, decreased FMD and increased carotid IMT were observed in hyperprolactinemic group. Serum prolactin was positively correlated with triglycerides, apoB/apoA-I ratio, hypogonadal, hsCRP and fibrinogen (P < 0.05), but inversely associated with apoA-I and HDL-C (P ≤ 0.001). Moreover, prolactin was found negatively correlated with FMD (r = -0.576, P < 0.0001), and positively correlated with mean carotid IMT (r = 0.652, P < 0.0001). Multivariate regression analysis revealed that prolactin determined, independent of traditional risk factors, FMD (B = -0.589, 95% confidence interval (CI) -2.525 to -0.804, P = 0.001) and mean carotid IMT (B = 0.527, 95% CI 0.027-0.069, P < 0.0001). Hyperprolactinemia may be involved in the preclinical increase in carotid IMT, directly or by promoting atherogenic factors, including

  13. Recommendations for Carotid Stenting in Korea

    PubMed Central

    Chang, Hyuk Won; Suh, Sang-il; Jeong, Hae Woong; Suh, Dae Chul

    2015-01-01

    Carotid artery angioplasty with stenting (CAS) is being performed in many hospitals in Korea. Most of the guidelines which are being used are similar, but the practical aspects such as techniques are different between hospitals. For example, usage of various protective devices, the oral antiplatelet regimen prior to procedure and placing of temporary pacemaker to prevent bradycardia are different between hospitals. In this article, we summarize and propose the guidelines for CAS which is currently being accepted in Korea. These guidelines may be helpful in providing protocol to neurointerventionalist who perform CAS and to standardize the process including reporting of CAS in the future comparative trials in Korea. PMID:25763292

  14. Pulsatile Flow Studies in Atherosclerotic Carotid Bifurcations

    NASA Astrophysics Data System (ADS)

    Bale-Glickman, Jocelyn; Selby, Kathy; Saloner, David; Savas, Omer

    2001-11-01

    Particle image velocimetry and flow visualization techniques are used to study flows in models of atherosclerotic carotid bifurcations. The flow models exactly replicate the interior geometry of plaque excised from patients. The input flows are physiological wave forms derived from Doppler Ultrasound scans done on patients before surgery. The systolic and diastolic Reynolds numbers are 300 and 900. The complex internal geometry of the diseased artery combined with the pulsatile input flow results in exceedingly complex flow patterns. These flow patterns include internal jets, three-dimensional shear layers, stagnation lines, and multiple recirculation and separation regions. The physiological input flows are compared to flows when the wave form is sinusoidal.

  15. Congenital Absence of the Internal Carotid Artery

    SciTech Connect

    Florio, Francesco; Balzano, Silverio; Nardella, Michele; Strizzi, Vincenzo; Cammisa, Mario; Bozzini, Vincenzo; Catapano, Giuseppe; D'Angelo, Vincenzo

    1999-01-15

    We report three cases of congenital absence of an internal carotid artery (ICA), diagnosed incidentally by digital subtraction angiography. The analysis of the cases is based on the classification of segmental ICA agenesis proposed by Lasjaunias and Berenstein. Usually the patients with this rare vascular anomaly are asymptomatic; some may have symptoms related to cerebrovascular insufficiency, compression by enlarged intracranial collateral vessels, or complications associated with cerebral aneurysms. Diagnosis of congenital absence of ICA is made by skull base computed tomography (CT) scan, CT and magnetic resonance angiography, and conventional or digital subtraction angiography.

  16. The Cat's Eye Nebula

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This NASA Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the 'Cat's Eye Nebula.' Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual 'fossil record' of the dynamics and late evolution of a dying star. A preliminary interpretation suggests that the star might be a double-star system. The suspected companion star also might be responsible for a pair of high-speed jets of gas that lie at right angles to this equatorial ring. If the companion were pulling in material from a neighboring star, jets escaping along the companion's rotation axis could be produced. These jets would explain several puzzling features along the periphery of the gas lobes. Like a stream of water hitting a sand pile, the jets compress gas ahead of them, creating the 'curlicue' features and bright arcs near the outer edge of the lobes. The twin jets are now pointing in different directions than these features. This suggests the jets are wobbling, or precessing, and turning on and off episodically. This color picture, taken with the Wide Field Planetary Camera-2, is a composite of three images taken at different wavelengths. (red, hydrogen-alpha; blue, neutral oxygen, 6300 angstroms; green, ionized nitrogen, 6584 angstroms). The image was taken on September 18, 1994. NGC 6543 is 3,000 light- years away in the northern constellation Draco. The term planetary nebula is a misnomer; dying stars create these cocoons when they lose outer layers of gas. The process has nothing to do with planet formation, which is predicted to happen early in a star's life.

  17. Air humidity and carotid rete function in thermoregulation of the goat.

    PubMed

    Jessen, C; Pongratz, H

    1979-07-01

    1. The effects of air humidity on respiratory rate have been studied in conscious goats exposed to an air temperature of + 33 degrees C. Before the experiments the animals had been chronically implanted with hypothalamic thermodes and intravascular heat exchangers to manipulate hypothalamic and general body core temperatures.2. Raising air humidity from 37 to 96% at constant air temperature resulted in a rise of respiratory rate, an immediate increase in hypothalamic temperature and a delayed smaller increase in general body core temperature.3. The rise of respiratory rate was smaller when general body core temperature was clamped at its control level and was absent when hypothalamic and general body core temperatures were clamped at their control levels during the humid air phase.4. It is concluded that the effect of high air humidity on respiratory rate in goats is predominantly the result of a rise in hypothalamic temperature acting on local thermosensitive structures. The carotid rete heat exchanger is thought to provide the thermal link between the evaporating surfaces of the upper respiratory tract and the hypothalamus.5. This function of the carotid rete heat exchanger is restricted to heat stressed animals. In animals subject to central cooling no local effects on hypothalamic temperature could be observed when the temperature of the inspired air was altered from + 33 to - 17 degrees C.

  18. Air humidity and carotid rete function in thermo-regulation of the goat

    PubMed Central

    Jessen, Claus; Pongratz, Hans

    1979-01-01

    1. The effects of air humidity on respiratory rate have been studied in conscious goats exposed to an air temperature of + 33 °C. Before the experiments the animals had been chronically implanted with hypothalamic thermodes and intravascular heat exchangers to manipulate hypothalamic and general body core temperatures. 2. Raising air humidity from 37 to 96% at constant air temperature resulted in a rise of respiratory rate, an immediate increase in hypothalamic temperature and a delayed smaller increase in general body core temperature. 3. The rise of respiratory rate was smaller when general body core temperature was clamped at its control level and was absent when hypothalamic and general body core temperatures were clamped at their control levels during the humid air phase. 4. It is concluded that the effect of high air humidity on respiratory rate in goats is predominantly the result of a rise in hypothalamic temperature acting on local thermosensitive structures. The carotid rete heat exchanger is thought to provide the thermal link between the evaporating surfaces of the upper respiratory tract and the hypothalamus. 5. This function of the carotid rete heat exchanger is restricted to heat stressed animals. In animals subject to central cooling no local effects on hypothalamic temperature could be observed when the temperature of the inspired air was altered from + 33 to - 17 °C. PMID:490377

  19. Cat Ownership Perception and Caretaking Explored in an Internet Survey of People Associated with Cats.

    PubMed

    Zito, Sarah; Vankan, Dianne; Bennett, Pauleen; Paterson, Mandy; Phillips, Clive J C

    2015-01-01

    People who feed cats that they do not perceive they own (sometimes called semi-owners) are thought to make a considerable contribution to unwanted cat numbers because the cats they support are generally not sterilized. Understanding people's perception of cat ownership and the psychology underlying cat semi-ownership could inform approaches to mitigate the negative effects of cat semi-ownership. The primary aims of this study were to investigate cat ownership perception and to examine its association with human-cat interactions and caretaking behaviours. A secondary aim was to evaluate a definition of cat semi-ownership (including an association time of ≥1 month and frequent feeding), revised from a previous definition proposed in the literature to distinguish cat semi-ownership from casual interactions with unowned cats. Cat owners and semi-owners displayed similar types of interactions and caretaking behaviours. Nevertheless, caretaking behaviours were more commonly displayed towards owned cats than semi-owned cats, and semi-owned cats were more likely to have produced kittens (p<0.01). All interactions and caretaking behaviours were more likely to be displayed towards cats in semi-ownership relationships compared to casual interaction relationships. Determinants of cat ownership perception were identified (p<0.05) and included association time, attachment, perceived cat friendliness and health, and feelings about unowned cats, including the acceptability of feeding unowned cats. Encouraging semi-owners to have the cats they care for sterilized may assist in reducing the number of unwanted kittens and could be a valuable alternative to trying to prevent semi-ownership entirely. Highly accessible semi-owner "gatekeepers" could help to deliver education messages and facilitate the provision of cat sterilization services to semi-owners. This research enabled semi-ownership to be distinguished from casual interaction relationships and can assist welfare and

  20. Hyperglycemia and Inflammatory Property of Circulating Monocytes are Associated with Inflammatory Property of Carotid Plaques in Patients Undergoing Carotid Endarterectomy

    PubMed Central

    Tanaka, Masashi; Masuda, Shinya; Matsuo, Yoshiyuki; Sasaki, Yousuke; Yamakage, Hajime; Muranaka, Kazuya; Wada, Hiromichi; Hasegawa, Koji; Tsukahara, Tetsuya; Shimatsu, Akira

    2016-01-01

    Aim: This study aims to determine the association between glucose metabolism and proinflammatory/anti-inflammatory properties of circulating monocytes or those of carotid plaques in patients who underwent carotid endarterectomy. Methods: Clinical characteristics and expression levels of proinflammatory/anti-inflammatory markers in circulating monocytes/carotid plaques were examined in 12 patients with diabetes and 12 patients without diabetes. Results: Circulating monocytes from patients with diabetes revealed higher tumor necrosis factor (TNF)-α and lower interleukin (IL)-10 expression levels compared with those from patients without diabetes, which was also observed in carotid plaques from patients with diabetes. Hyperglycemia revealed positive and negative correlations with the ratios of IL-6+ and IL-10+ cells in carotid plaques, respectively. Moreover, we determined a positive correlation between circulating monocytes and carotid plaques with respect to TNF-α and IL-6 expressions. Conclusions: The inflammatory property of circulating monocytes was associated with that of carotid plaques. Hyperglycemia increased inflammatory properties and decreased anti-inflammatory properties of carotid plaques. PMID:27001002

  1. Successful Endovascular Treatment of a Left Common Carotid Artery Aneurysm Following Failed Surgery of a Right Common Carotid Artery Aneurysm

    SciTech Connect

    Cil, Barbaros E. Ucar, Ibrahim; Ozsoy, Fatma; Arat, Anil; Yorgancioglu, Cem; Boeke, Erkmen

    2005-04-15

    Aneurysm of the common carotid artery is a rare and serious disease requiring prompt treatment in order to avoid neurologic complications. A 39-year-old man presented with voice impairment and a pulsatile mass at the right side of his neck and was found by color Doppler examination to have bilateral common carotid artery aneurysms of unknown origin. The right-sided large aneurysm was treated with placement of an 8 mm interposition Gore-Tex graft between the right common and internal carotid arteries. The surgical graft thrombosed 7 days after the surgery but the left-sided aneurysm was successfully treated by a Jostent peripheral stent-graft. Color Doppler examination showed a patent stent and no filling of the aneurysm on his first and sixth-month follow-up. Bilateral common carotid artery aneurysm is an exceptionally unusual condition and endovascular treatment of carotid artery aneurysms with covered stents may become an effective treatment alternative for these lesions.

  2. Medical treatment in carotid artery intervention.

    PubMed

    Kolkert, J L; Meerwaldt, R; Lefrandt, J D; Geelkerken, R H; Zeebregts, C J

    2011-12-01

    Medical treatment has a pivotal role in the treatment of patients with occlusive carotid artery disease. Large trials have provided the justification for operative treatment besides medical treatment in patients with recent significant carotid artery stenosis two decades ago. Since then, medical therapy has evolved tremendously. Next to aspirin, antiplatelet regimens acting on a different level in the modulation of platelet aggregation have made their entry. Moreover, statin therapy has been introduced. These changes among others in secondary stroke prevention, along with better understanding in life-style adjustments and perioperative medical management, have led to a decrease in stroke recurrence. Secondary prevention is therefore now the most important pillar of medical therapy. It consists of antiplatelet therapy, statins and blood pressure lowering agents in all patients. Small adjustments are recommended for those patients referred for invasive treatment. Moreover, long-term medical treatment is imperative. In this article, we summarize current evidence in literature regarding medical management in patients with previous stroke or TIA.

  3. Common Carotid Artery Occlusion: A Case Series

    PubMed Central

    Bajkó, Zoltán; Bălaşa, Rodica; Moţăţăianu, Anca; Maier, Smaranda; Chebuţ, Octavia Claudia; Szatmári, Szabolcs

    2013-01-01

    Subjects and Methods. We analysed 5000 cerebrovascular ultrasound records. A total of 0.4% of the patients had common carotid artery occlusion (CCAO). Results. The mean age was 59.8 ± 14.2 years, and the male/female ratio was 2.33. The most frequent risk factors were hypertension, ischaemic heart disease, dyslipidemia, diabetes mellitus, and smoking. Right-sided and left-sided CCAO occurred in 65% and 30% of the cases, respectively, and bilateral occlusion was detected in one case (5%). Patent bifurcation was observed in 10 cases of CCAO in which the anterograde flow in the ICA was maintained from the external carotid artery with reversed flow. In two of the cases, the occluded CCA was hypoplastic. The aetiology of CCAO in the majority of cases was the atherosclerosis (15 cases). The male/female ratio was higher in the patients with occluded distal vessels, and the short-term outcome was poorer. Only two cases from this series underwent revascularisation surgery. Spontaneous recanalisation was observed in one case. Conclusions. The most frequent cause of CCAO was atherosclerosis. The outcome is improved in the cases with patent distal vessels, and spontaneous recanalisation is possible. Treatment methods have not been standardised. Surgical revascularisation is possible in cases of patent distal vessels, but the indications are debatable. PMID:24167740

  4. Serum Uric Acid Is Associated with Carotid Plaques: The National Heart, Lung, and Blood Institute Family Heart Study

    PubMed Central

    NEOGI, TUHINA; ELLISON, R. CURTIS; HUNT, STEVEN; TERKELTAUB, ROBERT; FELSON, DAVID T.; ZHANG, YUQING

    2009-01-01

    Objective To examine the association of serum uric acid (SUA) with a marker of preclinical cardiovascular disease (CVD), carotid atherosclerotic plaques (PLQ), where early evidence of risk may be evident, focusing on individuals without CV risk factors. Methods The National Heart, Lung, and Blood Institute Family Heart Study is a multicenter study designed to assess risk factors for heart disease. PLQ were assessed with carotid ultrasound. We conducted sex-specific logistic regression to assess the association of SUA with presence of PLQ, including analyses among persons without risk factors related to both CVD and hyperuricemia. Results In total, 4866 participants had both SUA and carotid ultrasound assessed (54% women, mean age 52 yrs, mean body mass index 27.6). The association of SUA with PLQ increased with increasing SUA levels, demonstrating a dose-response relation for men [OR 1.0, 1.29, 1.61, 1.75, for SUA categories < 5 (reference), 5 to < 6, 6 to < 6.8, ≥ 6.8 mg/dl, respectively; p = 0.002]. Similar associations were found in men without CV risk factors. We found no relation of SUA with PLQ in women. Conclusion In this large study, SUA was associated with carotid atherosclerotic plaques in men. Results were similar in the absence of CV risk factors. These results suggest that SUA may have a pathophysiologic role in atherosclerosis in men. (J Rheumatol First Release Nov 15 2008; doi:10.3899/jrheum.080646) PMID:19012359

  5. Retroviruses and sexual size dimorphism in domestic cats (Felis catus L.).

    PubMed Central

    Pontier, D; Fromont, E; Courchamp, F; Artois, M; Yoccoz, N G

    1998-01-01

    Hochberg and co-workers have predicted that an increase in host adult mortality due to parasites is balanced by an earlier age at first reproduction. In polygynous species we hypothesize that such a pattern would lead to diverging selection pressure on body size between sexes and increased sexual size dimorphism. In polygynous mammals, male body size is considered to be an important factor for reproductive success. Thus, under the pressure of a virulent infection, males should be selected for rapid growth and/or higher body size to be able to compete successfully as soon as possible with opponents. In contrast, under the same selection pressure, females should be selected for lighter adult body size or rapid growth to reach sexual maturity earlier. We investigated this hypothesis in the domestic cat Felis catus. Orange cats have greater body size dimorphism than non-orange cats. Orange females are lighter than non-orange females, and orange males are heavier than non-orange males. Here, we report the extent to which orange and non-orange individuals differ in infection prevelance for two retroviruses, feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). FIV is thought to be transmitted almost exclusively through aggressive contacts between individuals, whereas FeLV transmission occurs mainly through social contacts. The pattern of infection of both diseases is consistent with the higher aggressiveness of orange cats. In both sexes, orange cats are significantly more infected by FIV, and tend to be less infected by FeLV than other cats. The pattern of infection is also consistent with an earlier age at first reproduction in orange than in non-orange cats, at least for females. These results suggest that microparasitism may have played an important role in the evolution of sexual size dimorphism of domestic cats. PMID:9493404

  6. Should patients with asymptomatic significant carotid stenosis undergo simultaneous carotid and cardiac surgery?

    PubMed Central

    Ogutu, Peter; Werner, Raphael; Oertel, Frank; Beyer, Michael

    2014-01-01

    A best evidence topic in cardiovascular surgery was written according to a structured protocol. The question addressed was whether patients with severe asymptomatic carotid and coronary artery diseases should undergo simultaneous carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG). A total of 624 papers were found using the reported search, of which 20 represent the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study results of these papers are tabulated. Previous cohort studies showed mixed results, while advocating for the necessity of a randomized controlled trial (RCT). A recent RCT showed that patients undergoing prophylactic or simultaneous CEA + CABG had lower rates of stroke (0%) compared with delayed CEA 1–3 months after CABG (7.7%), without significant perioperative mortality difference. This study included patients with unilateral severe (>70%) asymptomatic carotid stenosis requiring CABG. An earlier partly randomized trial also showed better outcomes for patients undergoing simultaneous procedures (P = 0.045). Interestingly, systematic reviews previously failed to show compelling evidence supporting prophylactic CEA. This could be partly due to the fact that these reviews collectively analyse different cohort qualities. Neurological studies have, however, shown reduced cognitive and phonetic quality and function in patients with unilateral and bilateral asymptomatic carotid artery stenosis. Twenty-one RCTs comparing lone carotid artery stenting (CAS) and CEA informed the American Heart Association guidelines, which declared CAS comparable with CEA for symptomatic and asymptomatic carotid stenosis (CS). However, the risk of death/stroke for CAS alone is double that for CEA alone in the acute phase following onset of symptoms, while CEA alone is associated with a doubled risk of myocardial infarction. There is

  7. Four cats with fungal rhinitis.

    PubMed

    Whitney, Beth L; Broussard, John; Stefanacci, Joseph D

    2005-02-01

    Fungal rhinitis is uncommon in the cat and cases of nasal aspergillosis-penicilliosis have been rarely reported. Signs of fungal rhinitis include epistaxis, sneezing, mucopurulent nasal discharge and exophthalmos. Brachycephalic feline breeds seem to be at increased risk for development of nasal aspergillosis-penicilliosis. Computed tomography (CT) imaging and rhinoscopy are useful in assessing the extent of the disease and in obtaining diagnostic samples. Fungal culture may lead to false negative or positive results and must be used in conjunction with other diagnostic tests. Serological testing was not useful in two cats tested. The cats in this study were treated with oral itraconazole therapy. When itraconazole therapy was discontinued prematurely, clinical signs recurred. Hepatotoxicosis is a possible sequel to itraconazole therapy.

  8. Q Fever (Coxiella burnetii) Knowledge and Attitudes of Australian Cat Breeders and Their Husbandry Practices.

    PubMed

    Shapiro, A J; Norris, J M; Bosward, K L; Heller, J

    2016-09-13

    A Q fever outbreak in a small animal veterinary hospital, associated with a cat caesarean section, initiated a cat seroprevalence study (n = 712) that found circulating antibodies to Coxiella burnetii was highest in cattery-confined breeding cats (9.3%). These findings stimulated interest about potential sources of C. burnetii infection for cats and humans associated with cats. Cat breeders are potentially a group at increased risk of C. burnetii infection, and this study sought to identify potential risk factors. A cross-sectional online survey was conducted targeting all domestic cat breeders registered with an affiliate member body in Australia in 2015. Responses from 177 cat breeders across Australia were analysed. Forty per cent of responding cat breeders had not heard of Q fever. Raw meat was fed as an integral constituent of the diet by 89% of respondents. Eighty per cent of respondents allowed queens access to the home for parturition, and assistance of queens and resuscitation of kittens at the time of birth were reported by 97% of respondents. Respondents who perceived some level of exposure to Q fever through their breeding activities were three times less likely to perform mouth-to-snout resuscitation (OR 0.3 95% CI 0.1-0.9; P = 0.034) than those who did not perceive a risk of exposure. Similarly, respondents who perceived Q fever as a risk through breeding activities were close to eight times more likely to use personal protective equipment during parturition (OR 7.7 95% CI 1.5-39.9; P = 0.015) than those who did not. Husbandry practices of cat breeders that may increase the risk of C. burnetii transmission require further targeted investigations to assess the contribution of these risk factors to the acquisition of disease. Concurrent education forums are recommended to inform Australian cat breeders of the aetiopathogenesis of Q fever.

  9. Parental history of premature myocardial infarction is a stronger predictor of increased carotid intima-media thickness than parental history of hypertension.

    PubMed

    Barra, S; Gaeta, G; Cuomo, V; Guarini, P; Cuomo, S; Capozzi, G; Tudisca, G; Madrid, A; Trevisan, M

    2011-06-01

    An increased carotid intima-media thickness (IMT) is detectable in young subjects with parental history of premature myocardial infarction (PHPMI) or hypertension (PHH). In this study we evaluated if PHPMI and PHH exert a different influence on carotid IMT and if their conjunction produces additive effects. High-resolution B-mode ultrasonographic evaluation of common carotid artery IMT was acquired from 48 subjects without PHPMI and PHH (22 males, 26 females; mean age 22.1±4.9 years; controls), 24 age- (±1 year) and sex-matched subjects with PHH without PHPMI (PHH-positive/PHPMI-negative subjects), 24 age- and sex-matched subjects with PHPMI without PHH (PHH-negative/PHPMI-positive subjects) and 24 age- and sex-matched subjects with both PHPMI and PHH (PHH/PHPMI-positive subjects). Lipid profile, resting blood pressure, smoking behaviour and body mass index (BMI) were also assessed. Carotid IMT was smaller in controls (0.41±0.07mm) compared to PHH-positive/PHPMI-negative subjects (0.47±0.10, p=0.023), to PHH-negative/PHPMI-positive subjects (0.54±0.11, p<0.001) and to PHH/PHPMI-positive subjects (0.52±0.10mm, p<0.001). Carotid IMT was greater in PHH-negative/PHPMI-positive (p=0.006) and in PHH/PHPMI-positive (p=0.031) than in PHH-positive/PHPMI-negative subjects. No difference in carotid IMT was evident between PHH-negative/PHPMI-positive and PHH/PHPMI-positive subjects (p=0.549). In the comparison among subjects using multiple regression analysis, only PHPMI, age and BMI were independently associated with carotid IMT. In healthy young subjects with PHPMI and/or PHH, carotid IMT is increased. PHPMI is a stronger predictor of increased carotid IMT than PHH. PHH in conjunction with PHPMI does not add any further detrimental effect on carotid IMT.

  10. Grooming and control of fleas in cats.

    PubMed

    Eckstein; Hart

    2000-05-10

    Oral grooming is common in cats, as in rodent and bovid species where grooming has been shown to be effective in removing lice and ticks. In Experiment 1, we examined the effectiveness of oral grooming in removing fleas which are the main ectoparasite of cats. Elizabethan collars (E-collars) which prevented grooming were fitted on nine cats in a flea-infested household and 3 weeks later, flea numbers on these cats were compared with nine control cats in the same household. Flea numbers dropped in the control cats reflecting an apparent drop in adult fleas in the environment, but in the E-collar cats, flea numbers did not drop, and were about twice as numerous as in control cats. The significantly greater number of fleas on the E-collar cats was attributed to their inability to groom off fleas. In Experiment 2, videotaping of nine different cats from the flea-infested household revealed that these cats groomed at about twice the rate of 10 similarly videotaped control cats from a flea-free colony. These results reveal that flea exposure can increase grooming rate in cats and that grooming is effective in removing fleas.

  11. Simultaneous Endovascular Treatment of Tandem Internal Carotid Lesions: Case Report and Review of Literature.

    PubMed

    Cvetic, Vladimir; Dragas, Marko; Colic, Momcilo; Vukasinovic, Ivan; Radmili, Oliver; Ilic, Nikola; Koncar, Igor; Bascarevic, Vladimir; Ristanovic, Natasa; Davidovic, Lazar

    2016-07-01

    The incidence of concomitant extracranial carotid artery stenosis and ipsilateral intracranial carotid aneurysm has been reported to vary between 2.8% and 5%. These complex lesions may present a challenge for treatment decision-making. This case report describes an asymptomatic male patient with severe carotid bifurcation stenosis, coupled with an unruptured supraclinoid internal carotid aneurysm. Both lesions were treated simultaneously. Patient underwent carotid stenting followed by aneurysm coiling in the same setting without any complication.

  12. Hydrocortisone supresses inflammatory activity of metalloproteinase - 8 in carotid plaque

    PubMed Central

    Gabriel, Sthefano Atique; Antonangelo, Leila; Capelozzi, Vera Luiza; Beteli, Camila Baumann; de Camargo Júnior, Otacílio; de Aquino, José Luis Braga; Caffaro, Roberto Augusto

    2015-01-01

    Objective Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone. Methods The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after carotid endarterectomy. In carotid plaque, tissue levels of MMP-8 and MMP-9 were measured. Results Group 1 showed increased serum levels of MMP- 8 (994.28 pg/ml and 408.54 pg/ml, respectively; P=0.045) and MMP-9 (106,656.34 and 42,807.69 respectively; P=0.014) at 1 hour after carotid endarterectomy compared to the control group. Symptomatic patients in Group 1 exhibited lower tissue concentration of MMP-8 in comparison to the control group (143.89 pg/ml and 1317.36 respectively; P=0.003). There was a correlation between preoperative MMP-9 levels and tissue concentrations of MMP-8 (P=0.042) and MMP-9 (P=0.019) between symptomatic patients in the control group. Conclusion Hydrocortisone reduces the concentration of MMP- 8 in carotid plaque, especially in symptomatic patients. There was an association between systemic and tissue inflammation. PMID:26313719

  13. Morphological age-dependent development of the human carotid bifurcation.

    PubMed

    Seong, Jaehoon; Lieber, Baruch B; Wakhloo, Ajay K

    2005-03-01

    The unique morphology of the adult human carotid bifurcation and its sinus has been investigated extensively, but its long-term, age-dependent development has not. It is important fundamentally and clinically to understand the hemodynamics and developmental forces that play a role in remodeling of the carotid bifurcation and maturation of the sinus in association with brain maturation. This understanding can lead to better prognostication and therapy of carotid disease. We analyzed the change of sinus morphology and the angle of the carotid bifurcation in four postnatal developmental stages (Group I: 0-2 years, Group II: 3-9 years, Group III: 10-19 years, and Group IV: 20-36 years, respectively) using multiprojection digital subtraction angiograms and image post-processing techniques. The most significant findings are the substantial growth of the internal carotid artery (ICA) with age and the development of a carotid sinus at the root of the ICA during late adolescence. The bifurcation angle remains virtually unchanged from infancy to adulthood. However, the angle split between the ICA and external carotid artery (ECA) relative to the common carotid artery (CCA) undergoes significant changes. Initially, the ICA appears to emanate as a side branch. Later in life, to reduce hydraulic resistance in response to increased flow demand by the brain, the bifurcation is remodeled to a construct in which both daughter vessels are a skewed continuation of the parent artery. This study provides a new analysis method to examine the development of the human carotid bifurcation over the developmental years, despite the small and sparse database. A larger database will enable in the future a more extensive analysis such as gender or racial differences.

  14. The paradox of Schrodinger's cat

    NASA Astrophysics Data System (ADS)

    Villars, C. N.

    1986-07-01

    Erwin Schrodinger first described the thought-experiment which has since become known as 'the paradox of Schrodinger's cat' 51 years ago. In recent years, popular accounts of quantum mechanics have tended to adopt one or other of the philosophically most extreme solutions to this paradox, i.e. the consciousness hypothesis or the many worlds interpretation. The author attempts to redress the balance by describing what he takes to be the orthodox solution to the paradox which explains the paradox, without recourse to such counterintuitive notions as a cat simultaneously dead and alive or a universe continually splitting into multiple worlds, as being due to a misapplication of the quantum formalism.

  15. High Agatston Calcium Score of Intracranial Carotid Artery

    PubMed Central

    Kao, Hung-Wen; Liou, Michelle; Chung, Hsiao-Wen; Liu, Hua-Shan; Tsai, Ping-Huei; Chiang, Shih-Wei; Chou, Ming-Chung; Peng, Giia-Sheun; Huang, Guo-Shu; Hsu, Hsian-He; Chen, Cheng-Yu

    2015-01-01

    Abstract The effect of intracranial internal carotid artery (ICA) calcification on cognitive impairment is uncertain. Our objective was to investigate whether intracranial ICA calcification is a significant cognitive predictor for cognitive impairment. Global cognition and degrees of intracranial ICA calcification of 579 subjects were assessed with Mini-Mental State Examination (MMSE) and Agatston calcium scoring method, respectively. Other risk factors for cognitive impairment, including age, education level, hypertension, diabetes mellitus, smoking, hyperlipidemia, and body mass index, were documented and analyzed for their associations with cognitive function. In univariate analyses, older age, lower education level, hypertension, diabetes mellitus, and higher intracranial ICA Agatston scores were significantly associated with cognitive impairment. In ordinal logistic regression, only age and total intracranial ICA Agatston score were significant risk factors for cognitive impairment. After adjustment for the other documented risk factors, subjects were 7% (95% CI: 5–10; P < 0.001) and 6% (95% CI: 0–13; P = 0.04) more likely to have lower cognitive category with every year increment of age and every 100-point increment of the total intracranial ICA Agatston score respectively. These results suggest an important role of the intracranial ICA calcification on cognitive impairment. PMID:26426620

  16. Safety, tolerability, and pharmacokinetics of 6-month daily dosing of an oral formulation of cyclosporine (ATOPICA for cats®) in cats

    PubMed Central

    Roberts, E S; VanLare, K A; Strehlau, G; Peyrou, M; Roycroft, L M; King, S

    2014-01-01

    Cyclosporine was proven efficacious in the treatment of feline hypersensitivity dermatitis. This target animal study was conducted to evaluate the safety, tolerability, and pharmacokinetics of ATOPICA for Cats® (cyclosporine oral solution, USP) MODIFIED following 6-month daily dosing in cats. Forty healthy cats (four cats/sex/group) received 0, 8 (1×), 16 (2×), 24 (3×), or 40 (5×) mg/kg cyclosporine once daily for 6 months (183 days). Body weight, food consumption, ophthalmoscopic, physical examinations including neurological assessments, blood pressure, electrocardiography, clinical pathology (hematology, coagulation, clinical chemistry, urinalysis), organ weights, and macroscopic and microscopic examinations were performed and assessed. In addition, blood concentrations of cyclosporine were measured at the pretreatment trough on Days 1, 2, 7, 14, 31, 91, 154, and 182, and post-treatment on Days 1, 31, and 182. Adverse effects possibly related to treatment included prolonged APTT and one report each of bone marrow hypocellularity and lymphoma; all occurred in cats treated with doses more than 16 mg/kg. There was no significant accumulation of cyclosporine beyond the first week of treatment. Results confirm that ATOPICA for Cats is safe and well tolerated in cats without unexpected accumulation beyond the first week of treatment when administered as directed. PMID:24134659

  17. Safety, tolerability, and pharmacokinetics of 6-month daily dosing of an oral formulation of cyclosporine (ATOPICA for cats®) in cats.

    PubMed

    Roberts, E S; Vanlare, K A; Strehlau, G; Peyrou, M; Roycroft, L M; King, S

    2014-04-01

    Cyclosporine was proven efficacious in the treatment of feline hypersensitivity dermatitis. This target animal study was conducted to evaluate the safety, tolerability, and pharmacokinetics of ATOPICA for Cats® (cyclosporine oral solution, USP) MODIFIED following 6-month daily dosing in cats. Forty healthy cats (four cats/sex/group) received 0, 8 (1×), 16 (2×), 24 (3×), or 40 (5×) mg/kg cyclosporine once daily for 6 months (183 days). Body weight, food consumption, ophthalmoscopic, physical examinations including neurological assessments, blood pressure, electrocardiography, clinical pathology (hematology, coagulation, clinical chemistry, urinalysis), organ weights, and macroscopic and microscopic examinations were performed and assessed. In addition, blood concentrations of cyclosporine were measured at the pretreatment trough on Days 1, 2, 7, 14, 31, 91, 154, and 182, and post-treatment on Days 1, 31, and 182. Adverse effects possibly related to treatment included prolonged APTT and one report each of bone marrow hypocellularity and lymphoma; all occurred in cats treated with doses more than 16 mg/kg. There was no significant accumulation of cyclosporine beyond the first week of treatment. Results confirm that ATOPICA for Cats is safe and well tolerated in cats without unexpected accumulation beyond the first week of treatment when administered as directed.

  18. SCAI/SVM expert consensus statement on carotid stenting: Training and credentialing for carotid stenting.

    PubMed

    Aronow, Herbert D; Collins, Tyrone J; Gray, William A; Jaff, Michael R; Kluck, Bryan W; Patel, Rajan A G; Rosenfield, Kenneth A; Safian, Robert D; Sobieszczyk, Piotr S; Wayangankar, Siddharth A; White, Christopher J

    2016-02-01

    Carotid artery stenting (CAS) has become an integral part of the therapeutic armamentarium offered by cardiovascular medicine programs for the prevention of stroke. The purpose of this expert consensus statement is to provide physician training and credentialing guidance to facilitate the safe and effective incorporation of CAS into clinical practice within these programs. Since publication of the 2005 Clinical Competence Statement on Carotid Stenting, there has been substantial device innovation, publication of numerous clinical trials and observational studies, accumulation of extensive real-world clinical experience and widespread participation in robust national quality improvement initiatives [5]. Collectively, these advances have led to substantial evolution in the selection of appropriate patients, as well as in the cognitive, technical and clinical skills required to perform safe and effective CAS. Herein, we summarize published guidelines, describe training pathways, outline elements of competency, offer strategies for tracking outcomes, specify facility, equipment and personnel requirements, and propose criteria for maintenance of CAS competency.

  19. External Carotid-Internal Jugular Fistula as a Late Complication After Carotid Endarterectomy: A Rare Case

    SciTech Connect

    Bakar, Bulent; Cekirge, Saruhan; Tekkok, Ismail Hakki

    2011-02-15

    A 66-year-old man presented with mild amnesia, progressive fatigue, ataxia, visual hallucinations, and debility. His past medical history included right-sided carotid endarterectomy performed elsewhere 6 years previously. Cranial magnetic resonance imaging showed left parieto-occipital arteriovenous malformation-like tortous vessels, venous congestion, and ischemic areas. Cerebral angiography showed right-sided compound external carotid artery-internal jugular vein (IJV) fistula, and distal occlusion of the right IJV. Transvenous embolization via contralateral IJV was performed, and the fistula, together with fistulous portion of the distal IJV, was sealed using coils. Two years later, patient is well with normal neurologic examination findings. The presence of an arteriovenous communication after vascular surgery is a serious complication with potential long-term effects and therefore should be diagnosed and treated as promptly as possible.

  20. On the mechanism of L-DOPA-induced postural hypotension in the cat

    PubMed Central

    Dhasmana, K. M.; Spilker, B. A.

    1973-01-01

    1. The effects of L-DOPA on postural hypotension and carotid occlusion pressor effect were studied, mainly in cats; the recovery of the blood pressure upon tilting was used as a measure of postural hypotension. 2. L-DOPA (30 mg/kg) partially depressed the carotid occlusion pressor effect and caused some degree of postural hypotension, L-DOPA (100 mg/kg) had more marked effects; the responses returned to control after 90 to 150 minutes. L-DOPA itself caused a pressor response in all cats. 3. The dopa decarboxylase inhibitor N1-(DL-seryl)-N2-(2,3,4-trihydroxybenzyl) hydrazine (RO4-4602, 50 and 10 mg/kg) had no effect itself on the tilt response but completely prevented the effects of L-DOPA on the carotid occlusion pressor effect and postural hypotension. 4. After RO4-4602 (3 and 1 mg/kg), L-DOPA (100 mg/kg) caused a brief rise of blood pressure followed by a longer lasting fall in horizontally-orientated cats (i.e. `supine' hypotension). No postural hypotension was observed after L-DOPA under these conditions. 5. Noradrenaline elicited only small and transient effects on postural hypotension, but dopamine's effects were more marked and longer lasting. Pressor dose-response relationships for noradrenaline were the same before and after L-DOPA, as well as in cats pretreated with L-DOPA for 4 days. 6. In cats with kidneys and intestines removed, the tilt reflex was still present. Dose-response curves to L-DOPA were the same as in normal animals. RO4-4602 (3 mg/kg) prevented postural hypotension and block of the carotid occlusion pressor effect; supine hypotension was also observed after L-DOPA. 7. The recovery response to tilting in spinal cats was markedly depressed or absent unless the blood pressure was elevated by angiotensin, in which experiments L-DOPA depressed the recovery upon tilting (i.e. induced postural hypotension). 8. Blood pressure responses to tyramine were increased after 10 mg/kg of L-DOPA, but depressed after 100 mg/kg. The response to tyramine was