Sample records for arachidonic acid-induced ear

  1. Inhibition of arachidonic acid-induced ear oedema as a model for assessing topical anti-inflammatory compounds

    Microsoft Academic Search

    A. Crummey; G. P. Harper; E. A. Boyle; F. R. Mangan

    1987-01-01

    We have found that mouse ear oedema induced by the topical application of arachidonic acid is not a specific screen for compounds inhibiting the lipoxygenase or cyclo-oxygenase pathways of arachidonic acid metabolism. Although such compounds are able to reduce the oedema substantially, pharmacological agents such as histamine antagonists, phosphodiesterase inhibitors, free radical scavengers, and also various compounds not normally considered

  2. Intravenous anesthetic propofol suppresses prostaglandin E2 and cysteinyl leukotriene production and reduces edema formation in arachidonic acid-induced ear inflammation.

    PubMed

    Inada, Takefumi; Hirota, Kiichi; Shingu, Koh

    2015-07-01

    Propofol is an intravenous drug widely used for anesthesia and sedation. Previously, propofol was shown to inhibit cyclo-oxygenase (COX) and 5-lipoxygenase (5-LOX) activities. Because these enzyme-inhibiting effects have only been demonstrated in vitro, this study sought to ascertain whether similar effects might also be observed in vivo. In the current studies, effects of propofol were tested in a murine model of arachidonic acid-induced ear inflammation. Specifically, propofol - as a pre-treatment -- was intraperitoneally and then topical application of arachidonic acid was performed. After 1?h, tissue biopsies were collected and tested for the presence of edema and for levels of inflammatory mediators. The results indicated that the administration of propofol significantly suppressed ear edema formation, tissue myeloperoxidase activity, and tissue production of both prostaglandin E2 and cysteinyl leukotrienes. From the data, it can be concluded that propofol could exert anti-COX and anti-5-LOX activities in an in vivo model and that these activities in turn could have, at least in part, suppressed arachidonic acid-induced edema formation in the ear. PMID:25046027

  3. Effect of Desmodium adscendens fractions on antigen- and arachidonic acid-induced contractions of guinea pig airways.

    PubMed

    Addy, M E; Burka, J F

    1988-06-01

    Three fractions (n-butanol, F2, and L5), isolated from an aqueous extract of Desmodium adscendens, a plant used in Ghana for the management of asthma, were evaluated for their pharmacological activity using ovalbumin and arachidonic acid-induced contractions of guinea pig airways. All three fractions inhibited the ovalbumin-induced contractions of indomethacin-pretreated tracheal spirals from sensitized animals dose dependently, but only L5 and n-butanol inhibited such contractions in the absence of indomethacin. The concentrations required to inhibit ovalbumin-induced contractions of lung parenchymal strips were threefold higher than with trachea. The contractile response over a 60-min period was divided into three phases. F2 and n-butanol inhibited all phases, whereas L5 inhibited only the late phase. n-Butanol and L5 inhibited arachidonic acid-induced contractions on indomethacin-pretreated tracheal spirals, a leukotriene-dependent reaction. There was no inhibition of arachidonic acid-induced contractions of lung parenchymal strips, which is largely a thromboxane-dependent reaction. The results suggest that D. adscendens contains several pharmacologically active substances that can inhibit allergic airway smooth muscle contraction at multiple sites, including the synthesis and (or) activity of the bronchoconstrictor leukotrienes. PMID:3139272

  4. MAP2c prevents arachidonic acid-induced fibril formation of tau: Role of chaperone activity and phosphorylation.

    PubMed

    Mitra, Gopa; Gupta, Suvroma; Poddar, Asim; Bhattacharyya, Bhabatarak

    2015-10-01

    Tau has long been associated with Alzheimer's disease, where it forms neurofibrillary tangles. Here we show for the first time by electron microscopy that MAP2c prevents arachidonic acid-induced in vitro aggregation of tau. However, phosphorylated MAP2c failed to prevent the same. Previously we reported that MAP2c possesses chaperone-like activity while tau does not (Sarkar et al., 2004, Eur J Biochem., 271(8), 1488-96). Here we demonstrate that phosphorylation severely impaired the chaperone activity of MAP2c, implying a crucial role of chaperone in preventing tau fibrillation. Additionally, the ability of MAP2c to induce microtubule polymerization was abolished completely upon phosphorylation. As tau and MAP2c possess highly homologous C-termini, we speculated that the N-terminus of MAP2c might account for its chaperone activity. Nevertheless, experiments showed that N-terminus of MAP2c alone is inactive as a chaperone. Our preliminary findings suggest that MAP2c/MAP2 could be one of the regulators maintaining tau homeostasis in the cell. PMID:26071842

  5. 21-aminosteroid and 2-(aminomethyl)chromans inhibition of arachidonic acid-induced lipid peroxidation and permeability enhancement in bovine brain microvessel endothelial cell monolayers

    E-print Network

    Shi, Fenglin; Cavitt, Jennifer; Audus, Kenneth L.

    1995-09-01

    Selected 21-aminosteroids (U74500A, U74006F, and U74389G) and a 2-(aminomethyl)chromans (U78517F) were tested for their efficacy in preventing arachidonate-induced lipid peroxidation and permeability alterations in brain microvessel endothelial...

  6. Electroacupuncture at ST36-ST37 and at ear ameliorates hippocampal mossy fiber sprouting in kainic acid-induced epileptic seizure rats.

    PubMed

    Liu, Chung-Hsiang; Lin, Yi-Wen; Hsu, Hsin-Cheng; Liu, Hsu-Jan; Lin, Wan-Jung; Hsieh, Ching-Liang

    2014-01-01

    Our previous study showed that mossy fiber sprouting can occur in the hippocampus region in rats 6 wk after kainic acid-induced epileptic seizure, and this mossy fiber sprouting can facilitate epileptogenesis. Transcutaneous auricular vagal nerve stimulation (VNS), which is similar to cervical VNS, can reduce the occurrence of epileptic seizure in intractable epilepsy patients. Greater parasympathetic nerve activity can be caused by 2 Hz electroacupuncture (EA). Therefore, we investigated the effect of 2 Hz EA at ST-36-ST37 and at the ear on mossy fiber sprouting in kainic-treated Sprague-Dawley rats. The results indicated that applying 2 Hz EA at ST36-ST37 and at the ear for 3 d per week over 6 consecutive weeks can ameliorate mossy fiber sprouting in the hippocampus region of rats. These results indicated that applying 2 Hz EA at ST36-ST37 and at the ear might be beneficial for the treatment and prevention of epilepsy in humans. PMID:25045697

  7. Electroacupuncture at ST36-ST37 and at Ear Ameliorates Hippocampal Mossy Fiber Sprouting in Kainic Acid-Induced Epileptic Seizure Rats

    PubMed Central

    Lin, Yi-Wen; Liu, Hsu-Jan; Lin, Wan-Jung

    2014-01-01

    Our previous study showed that mossy fiber sprouting can occur in the hippocampus region in rats 6?wk after kainic acid-induced epileptic seizure, and this mossy fiber sprouting can facilitate epileptogenesis. Transcutaneous auricular vagal nerve stimulation (VNS), which is similar to cervical VNS, can reduce the occurrence of epileptic seizure in intractable epilepsy patients. Greater parasympathetic nerve activity can be caused by 2?Hz electroacupuncture (EA). Therefore, we investigated the effect of 2?Hz EA at ST-36-ST37 and at the ear on mossy fiber sprouting in kainic-treated Sprague-Dawley rats. The results indicated that applying 2?Hz EA at ST36-ST37 and at the ear for 3?d per week over 6 consecutive weeks can ameliorate mossy fiber sprouting in the hippocampus region of rats. These results indicated that applying 2?Hz EA at ST36-ST37 and at the ear might be beneficial for the treatment and prevention of epilepsy in humans. PMID:25045697

  8. Arachidonic Acid–Induced Dilation in Human Coronary Arterioles: Convergence of Signaling Mechanisms on Endothelial TRPV4?Mediated Ca2+ Entry

    PubMed Central

    Zheng, Xiaodong; Zinkevich, Natalya S.; Gebremedhin, Debebe; Gauthier, Kathryn M.; Nishijima, Yoshinori; Fang, Juan; Wilcox, David A.; Campbell, William B.; Gutterman, David D.; Zhang, David X.

    2013-01-01

    Background Arachidonic acid (AA) and/or its enzymatic metabolites are important lipid mediators contributing to endothelium?derived hyperpolarizing factor (EDHF)–mediated dilation in multiple vascular beds, including human coronary arterioles (HCAs). However, the mechanisms of action of these lipid mediators in endothelial cells (ECs) remain incompletely defined. In this study, we investigated the role of the transient receptor potential vanilloid 4 (TRPV4) channel in AA?induced endothelial Ca2+ response and dilation of HCAs. Methods and Results AA induced concentration?dependent dilation in isolated HCAs. The dilation was largely abolished by the TRPV4 antagonist RN?1734 and by inhibition of endothelial Ca2+?activated K+ channels. In native and TRPV4?overexpressing human coronary artery ECs (HCAECs), AA increased intracellular Ca2+ concentration ([Ca2+]i), which was mediated by TRPV4?dependent Ca2+ entry. The AA?induced [Ca2+]i increase was inhibited by cytochrome P450 (CYP) inhibitors. Surprisingly, the CYP metabolites of AA, epoxyeicosatrienoic acids (EETs), were much less potent activators of TRPV4, and CYP inhibitors did not affect EET production in HCAECs. Apart from its effect on [Ca2+]i, AA induced endothelial hyperpolarization, and this effect was required for Ca2+ entry through TRPV4. AA?induced and TRPV4?mediated Ca2+ entry was also inhibited by the protein kinase A inhibitor PKI. TRPV4 exhibited a basal level of phosphorylation, which was inhibited by PKI. Patch?clamp studies indicated that AA activated TRPV4 single?channel currents in cell?attached and inside?out patches of HCAECs. Conclusions AA dilates HCAs through a novel mechanism involving endothelial TRPV4 channel?dependent Ca2+ entry that requires endothelial hyperpolarization, PKA?mediated basal phosphorylation of TRPV4, and direct activation of TRPV4 channels by AA. PMID:23619744

  9. Arachidonic Acid Causes Sudden Death in Rabbits

    Microsoft Academic Search

    Melvin J. Silver; Willis Hoch; James J. Kocsis; Carol M. Ingerman; J. Bryan Smith

    1974-01-01

    Injection of sodium arachidonate (1.4 milligrams per kilogram) into the marginal ear veins of rabbits caused death within 3 minutes. Histological examination showed platelet thrombi in the microvasculature of the lungs. Rabbits were protected from the lethal effects of arachidonic acid by pretreatment with aspirin. Fatty acids closely related to arachidonic acid did not cause death.

  10. Ear Disorders

    MedlinePLUS

    ... most common illness in infants and young children. Tinnitus, a roaring in your ears, can be the ... problems in your inner ear; its symptoms include tinnitus and dizziness. Ear barotrauma is an injury to ...

  11. Ear wax

    MedlinePLUS

    ... water to drain. You may need to repeat irrigation several times. To avoid damaging your ear or ... who may remove the wax by: Repeating the irrigation attempts Suctioning the ear canal Using a small ...

  12. Elephant ear

    MedlinePLUS

    Elephant ear plants are indoor or outdoor plants with very large, arrow-shaped leaves. Poisoning may occur ... Elephant ear grows naturally in tropical and subtropical areas, but is easily found in northern climates as ...

  13. Ear Infections

    MedlinePLUS

    ... affects the middle ear and is called otitis media. The tubes inside the ears become clogged with fluid and mucus. This can affect hearing, because sound cannot get through all that fluid. If your child isn't old enough to say "My ear ...

  14. Ear wax

    PubMed Central

    2008-01-01

    Introduction Ear wax only becomes a problem if it causes a hearing impairment or other ear-related symptoms. Ear wax is more likely to accumulate and cause a hearing impairment when normal extrusion is prevented — for example, by the use of hearing aids, or by the use of cotton buds to clean the ears. Ear wax can visually obscure the ear drum, and may need to be removed for diagnostic purposes. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical question: What are the effects of methods to remove ear wax? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2007 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found nine systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: ear syringing; manual removal (other than ear syringing); and wax softeners (alone or prior to syringing). PMID:19450340

  15. Role of arachidonic acid cascade in Rhinella arenarum oocyte maturation.

    PubMed

    Ortiz, Maria Eugenia; Arias-Torres, Ana Josefina; Zelarayán, Liliana Isabel

    2015-08-01

    There are no studies that document the production of prostaglandins (PGs) or their role in Rhinella arenarum oocyte maturation. In this study, we analysed the effect of arachidonic acid (AA) and prostaglandins (PGs) on maturation, activation and pronuclear formation in R. arenarum oocytes. Our results demonstrated that AA was capable of inducing maturation in time-dependent and dose-dependent manner. Arachidonic acid-induced maturation was inhibited by indomethacin. PGs from AA hydrolysis, such as prostaglandin F2? (PGF2?) and, to a lesser extent, PGE2, induced meiosis resumption. Oocyte maturation in response to PGF2? was similar to that produced by progesterone (P4). Oocyte response to PGE1 was scarce. Rhinella arenarum oocyte PGF2?-induced maturation showed seasonal variation. From February to June, oocytes presented low sensitivity to PGF2?. In following periods, this response increased until a maximum was reached during October to January, a close temporal correlation with oocyte response to P4 being observed. The effect of PGF2? on maturation was verified by analysing the capacity of oocytes to activate and form pronuclei after being injected with homologous sperm. The cytological analysis of activated oocytes demonstrated the absence of cortical granules in oocytes, suggesting that PGF2? induces germinal vesicle breakdown (GVBD) and meiosis resumption up to metaphase II. In turn, oocytes matured by the action of PGF2? were able to form pronuclei after fertilization in a similar way to oocyte maturated by P4. In microinjection of mature cytoplasm experiments, the transformation of pre-maturation promoting factor (pre-MPF) to MPF was observed when oocytes were treated with PGF2?. In summary, our results illustrated the participation of the AA cascade and its metabolites in maturation, activation and pronuclei formation in R. arenarum. PMID:24964276

  16. Inhibition of arachidonic acid metabolism in colonic inflammation

    SciTech Connect

    Phyall, W.B.; Rush, J.A.; Fondacaro, J.D.

    1986-03-01

    The authors have previously identified a lipoxygenase product profile in the acetic acid-induced model of colonic inflammation in the rat and have demonstrated utility of this model in evaluating inhibitors of arachidonic acid (AA) metabolism under in vitro conditions. They now demonstrate efficacy of an inhibitor of AA metabolism in this model under in vivo conditions. Male rats were pretreated with either nordihydroguaiaretic acid (NDGA) (50 mg/kg, p.o.) or vehicle for 3 consecutive days prior to induction of colonic inflammation with intraluminal administration of 2 mls of 5% acetic acid. After sacrifice, colonic mucosa was removed and incubated in the presence and absence of Ca/sup 2 +/ ionophore, A23187 (2 ..mu..M) for 5 min at 37/sup 0/C. Production of AA metabolites (LTB/sub 4/, 5-HETE, PGE/sub 2/, TxB/sub 2/) was determined by high pressure liquid chromatography and radioimmunoassay. NDGA treatment caused a significant inhibition of metabolite production (LTB/sub 4/, 5-HETE, PGE/sub 2/, TxB/sub 2/) compared to vehicle controls. This inhibition was evident in both ionophore-stimulated and non-stimulated samples. These results show that intestinal AA metabolism can be inhibited by in vivo drug administration and further suggest that this animal model may provide a simple means for evaluating potential therapies for inflammatory bowel disease.

  17. Fusidic acid induced acute immunologic thrombocytopenia.

    PubMed

    El-Kassar, N; Kalfon, P; Fromont, P; Vezinet, C; Godeau, B; Duedari, N; Bierling, P

    1996-05-01

    Fusidic acid is used in hospitals as second-line therapy for multidrug-resistant staphylococcal infections. We report the first fully documented case of fusidic acid induced thrombocytopenia, in a 48-year-old patient. The thrombocytopenia was abrupt and severe but resolved spontaneously 7 d after drug withdrawal. The thrombocytopenia transiently relapsed 6 d later, when fusidic acid was reintroduced. Haemorrhagic signs were observed, but no severe bleeding occurred. Platelet transfusions failed to increase the platelet count. We detected an IgG platelet antibody in the patient's serum, that specifically recognized platelet glycoprotein IIb/IIIa only in the presence of fusidic acid. Fusidic acid induced thrombocytopenia should be considered as a possible cause for the thrombocytopenia frequently seen in the intensive care setting. PMID:8639443

  18. Acid induced unfolding of anthrax protective antigen

    Microsoft Academic Search

    Pradeep K Gupta; Raj K Kurupati; Harish Chandra; Reetika Gaur; Vibha Tandon; Yogendra Singh; Kapil Maithal

    2003-01-01

    Acidic pH plays an important role in the membrane insertion of protective antigen (PA) of anthrax toxin leading to the translocation of the catalytic moieties. The structural transitions occurring in PA as a consequence of change in pH were investigated by fluorescence and circular dichroism measurements. Our studies revealed the presence of two intermediates on-pathway of acid induced unfolding; one

  19. Arachidonic acid metabolism in cultured mouse keratinocytes

    SciTech Connect

    Kondoh, H.; Sato, Y.; Kanoh, H.

    1985-07-01

    The authors attempted to characterize the general features of arachidonate metabolism in cultured mouse keratinocytes. The cells labeled with (/sup 3/H)arachidonate were stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA), ionophore A23187, and fetal bovine serum (FBS). Common to the three substances, phosphatidylinositol, phosphatidylethanolamine, and phosphatidylcholine almost equally served as sources of arachidonate liberated by the action of phospholipase A2. The stimulation of phospholipase A2 action was observed in the order of A23187 greater than FBS greater than TPA. When stimulated by TPA or A23187, the radioactivity released into the extracellular medium was mostly found in prostaglandin (PG) E2. Formation of other PGs and hydroxyeicosatetraenoate (HETE) was extremely limited. In the case of stimulation by FBS, however, the released radioactivity was mainly associated with non-converted arachidonate. FBS also inhibited the TPA- and A23187-induced conversion of arachidonate to PGE2. Phospholipid degradation induced by the three stimulators was similarly dependent on extracellular Ca/sup 2 +/. The stimulation by FBS and A23187 was suppressed by calmodulin antagonists, though the effect of A23187 was much more sensitive to the antagonists when compared to that of FBS. The authors observed more than additive effects of the three stimulators when tested together.

  20. A study of the novel anti-inflammatory agent florifenine topical anti-inflammatory activity and influence on arachidonic acid metabolism and neutrophil functions

    Microsoft Academic Search

    Gloria Bustos; Maria Luisa Ferrándiz; Maria Jesús Sanz; Miguel Payá; Maria José Alcaraz

    1995-01-01

    We have evaluated the effects of the novel anti-inflammatory agent florifenine, 2-(1-Pyrrolidinyl)ethyl N-[7-(trifluoromethyl)-4-quinolyl]anthranilate, on topical inflammation in mice, free radical-mediated reactions, arachidonic acid metabolism and some neutrophil functions. Topical administration of florifenine produced dose-related anti-inflammatory activity in 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear oedema and with a lower potency, in the response induced by arachidonic acid (AA). Florifenine also inhibited neutrophil migration

  1. Arachidonic acid and male genital differentiation

    Microsoft Academic Search

    A. S. Goldman

    1987-01-01

    Arachidonic acid (AA) prevents neural tube defects, cleft palate, and micrognathia in the rat models of diabetic embryopathy and neural tube defects in the mouse embryo culture model. In this study, the involvement of AA in the male genital differentiation was described. These observations raise the complementary possibility that the AA-prostaglandin biochemical pathway may be a major mechanism mediating many

  2. Ear infection - chronic

    MedlinePLUS

    Middle ear infection - chronic; Otitis media - chronic; Chronic otitis media; Chronic ear infection ... Kerschner JE. Otitis media. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Saunders ...

  3. Ear drainage culture

    MedlinePLUS

    ... needed. Your health care provider will use a cotton swab to collect the sample from inside the ... Using a cotton swab to take a sample of drainage from the outer ear is not painful. However, ear pain may ...

  4. ?-Hydroxybutyric Acid-Induced Electrographic Seizures

    PubMed Central

    Cheung, Joseph; Lucey, Brendan P.; Duntley, Stephen P.; Darken, Rachel S.

    2014-01-01

    We describe a case of absence-like electrographic seizures during NREM sleep in a patient who was taking sodium oxybate, a sodium salt of ?-hydroxybutyric acid (GHB). An overnight full montage electroencephalography (EEG) study revealed numerous frontally predominant rhythmic 1.5-2 Hz sharp waves and spike-wave activity during stage N2 and N3 sleep at the peak dose time for sodium oxybate, resembling atypical absence-like electrographic seizures. The patient was later weaned off sodium oxybate, and a repeat study did not show any such electrographic seizures. Absence-like seizures induced by GHB had previously been described in experimental animal models. We present the first reported human case of absence-like electrographic seizure associated with sodium oxybate. Citation: Cheung J, Lucey BP, Duntley SP, Darken RS. ?-hydroxybutyric acid-induced electrographic seizures. J Clin Sleep Med 2014;10(7):811-812. PMID:25024661

  5. [Middle ear physiology].

    PubMed

    Ayerbe, I; Négrevergne, M; Ucelay, R; Sanchez Fernandez, J M

    1999-01-01

    The middle ear forms part of the sound transformer mechanism, together with the outer ear and the conducting system of the inner ear. An intermediate sensory organ, sensitive to acoustic vibration, and linked to the inner ear, the middle ear made its appearance during the period of adaptation of marine creatures to a terrestrial habitat; its presence is therefore a phylogenetic requirement. It is classical to ascribe three functions to the middle ear: the transmission of acoustic vibrations from the tympanic membrane to the cochlea, impedance matching between the air in the external auditary meatus and the labyrinthine fluids, and protection of the inner ear by means of the acoustic reflex. If the classical mechanical explanation has been able to explain its function, the conceptualization of its physiology in terms of energy allows an even better understanding, as well as providing and explanation for the paradoxes which arise in clinical practice when the classical model is used. PMID:10769562

  6. Production of arachidonic acid by Mortierella fungi

    Microsoft Academic Search

    Yoshifumi Shinmen; Sakayu Shimizu; Kengo Akimoto; Hiroshi Kawashima; Hideaki Yamada

    1989-01-01

    Various Mortierella fungi were assayed for their productivity of arachidonic acid (ARA). Only strains belonging to the subgenus Mortierella accumulated detectable amounts of ARA together with dihomo-?-linolenic acid. None of the strains belonging to the subgenus Micromucor tested accumulated these C-20 fatty acids, although they produced a C-18 fatty acid, ?-linolenic enic acid. A soil isolate, M. alpina 1S-4, was

  7. Mechanisms of nordihydroguaiaretic acid-induced growth inhibition and apoptosis in human cancer cells

    PubMed Central

    Seufferlein, T; Seckl, M J; Schwarz, E; Beil, M; v Wichert, G; Baust, H; Lührs, H; Schmid, R M; Adler, G

    2002-01-01

    Lipoxygenase metabolites of arachidonic acid can act as growth promoting factors for various cancer cell lines. Here we demonstrate that the 5-lipoxygenase inhibitor nordihydroguaiaretic acid potently inhibits anchorage-independent growth of human pancreatic and cervical cancer cells in soft agar and delays growth of pancreatic and cervical tumours established in athymic mice. Furthermore, nordihydroguaiaretic acid induces apoptosis of these cancer cells in vitro and in vivo. Potential mechanisms mediating these effects of nordihydroguaiaretic acid were examined. Nordihydroguaiaretic acid had no inhibitory effect on growth and survival signals such as tyrosine phosphorylation of the epidermal growth factor receptor or basal and growth factor-stimulated activities of extracellular signal-regulated kinase 1/2, p70s6k and AKT but selectively inhibited expression of cyclin D1 in the cancer cells. In addition, treatment with nordihydroguaiaretic acid lead to a disruption of the filamentous actin cytoskeleton in human pancreatic and cervical cancer cells which was accompanied by the activation of Jun-NH2-terminal kinase and p38mapk. Similar effects were obtained by treatment of the cancer cells with cytochalasin D. These results suggest that nordihydroguaiaretic acid induces anoikis-like apoptosis as a result of disruption of the actin cytoskeleton in association with the activation of stress activated protein kinases. In conclusion, nordihydroguaiaretic acid could constitute a lead compound in the development of novel therapeutic agents for various types of cancer. British Journal of Cancer (2002) 86, 1188–1196. DOI: 10.1038/sj/bjc/6600186 www.bjcancer.com © 2002 Cancer Research UK PMID:11953870

  8. [Tumor promotion and arachidonic acid cascades].

    PubMed

    Yamamoto, S

    1993-06-01

    Chemical carcinogenesis can be subdivided at least into two stages, i.e., initiation and promotion, in the mouse skin carcinogenesis model. There is considerable evidence supporting the relevance of the above concept to chemical carcinogenesis of other organs. Initiation represents the stage in which a carcinogen interacts with DNA and causes irreversible damage on the genome. Subsequent repeated exposure to a tumor promoter leads to a phenotypic expression of the initiated cells to tumor cells. In our living environment, a larger number of carcinogens may exist and exposure to a minute amount of carcinogen even once may be sufficient to generate initiated cells; therefore, prevention of carcinogenesis at the stage of initiation is not an easy task. In contrast to the initiation stage, the promotion stage is essentially reversible, and a relatively long period is required to accomplish this process. Therefore, prevention of chemical carcinogenesis in the promotion stage seems more practical than preventing carcinogenesis in the initiation stage. There is much evidence suggesting that arachidonic acid cascades play important roles both in the initiation stages. There is much evidence suggesting that arachidonic acid cascades play important roles both in the initiation and promotion stages. In the two-stage skin carcinogenesis, inhibitors of arachidonic acid cascades, especially lipoxygenase inhibitors, effectively prevent tumor formation by inhibiting the stage of tumor promotion caused by different types of tumor promoters. Although at present, the role(s) of lipoxygenase pathways in the mechanism of tumor promotion is not fully understood, the potential use of lipoxygenase inhibitors for the prevention of chemical carcinogenesis is anticipated. PMID:8340020

  9. Polyunsaturated fatty acids induce polarized submembranous F-actin aggregates and kill Entamoeba histolytica.

    PubMed

    Manna, Dipak; Grewal, Jaspreet Singh; Sarkar, Bidyut; Maiti, Sudipta; Lohia, Anuradha

    2013-05-01

    We have recently identified a novel galacto-glycerolipid (GGL) from the plant Oxalis corniculata that killed the human pathogen Entamoeba histolytica. In this study, we show that the anti-amoebic activity of GGL was due to the polyunsaturated fatty acid ?-linolenic acid (C18:3 ) side chain. Treatment of ?-linolenic acid to E. histolytica trophozoites disrupted the cytoskeletal network and led to polarization of F-actin at one end of the cells with prominent filopodial extensions. In addition, clustering of surface receptors and signaling molecules was also observed adjacent to the polarized actin similar to concanavalin-A-(Con-A) induced capping. But, in contrast to Con-A-induced capping, ?-linolenic acid induced caps were not shed and showed accumulation of long and numerous filopodia at the cap site. We found that ?-linolenic acid disrupts the actin cytoskeletal network, which led to the detachment of plasma membrane from the underlying cytoskeleton. A similar effect was observed with other dietary fatty acids such as linoleic acid (C18:2 ), arachidonic acid (C20:4 ), eicosapentaenoic acid (C20:5 ), and docosahexaenoic acid (C22:6 ). Our findings showed that dietary polyunsaturated fatty acids are powerful anti-amoebic agents that lead to disruption of the actin cytoskeleton. PMID:23568815

  10. Middle ear promontory osteoma.

    PubMed

    Toro, Paula Cruz; Castillo, Angela Callejo; Moya Martínez, Rafael; Domènech Juan, Iván

    2014-01-01

    Osteomas are benign lesions of the lamellar bone that within the temporal region are common in the external ear canal. Osteomas of the middle ear are extremely rare and until now there are only 14 reported cases. They usually present with conductive hearing loss while others are asymptomatic and diagnosed incidentally. PMID:25087466

  11. Natural ear rings.

    PubMed

    Sabaretnam, Mayilvaganan; Virupakshaiah, Akash; Baruah, Rishiraj

    2015-05-01

    Ear lobe keloids are common following ear piercing and these lesions are conspicuous and cosmetically unappealing. Multiple methods including surgery, radiotherapy, anti mitotic agents, silicone sheet, pressure clips, and cryotherapy have been used. The Challenge is to have a good cosmetic outcome with minimal recurrence. PMID:25984317

  12. Natural ear rings

    PubMed Central

    Sabaretnam, Mayilvaganan; Virupakshaiah, Akash; Baruah, Rishiraj

    2015-01-01

    Key Clinical Message Ear lobe keloids are common following ear piercing and these lesions are conspicuous and cosmetically unappealing. Multiple methods including surgery, radiotherapy, anti mitotic agents, silicone sheet, pressure clips, and cryotherapy have been used. The Challenge is to have a good cosmetic outcome with minimal recurrence. PMID:25984317

  13. Ear tube insertion - series (image)

    MedlinePLUS

    Ear tube insertion is recommended for: fluid in the middle ear (present for more than 12 weeks) recurrent ear ... the accumulated fluid is suctioned out. A small tube is inserted through the incised eardrum in order ...

  14. Ear - blocked at high altitudes

    MedlinePLUS

    ... ears; Flying and blocked ears; Eustachian tube dysfunction - high altitude ... the middle ear and the back of the nose and upper throat. ... down from high altitudes. Chewing gum the entire time you are ...

  15. Luteolin prevents uric acid-induced pancreatic ?-cell dysfunction.

    PubMed

    Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

    2014-07-01

    Elevated uric acid causes direct injury to pancreatic ?-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced ?-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-?B. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase (iNOS) in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acid-induced inhibition of glucose-stimulated insulin secretion (GSIS) in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-?B was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acid-induced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic ?-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic ?-cells in hyperuricemia-associated diabetes. PMID:25050113

  16. Ear infection - acute

    MedlinePLUS

    ... Risk factors for acute ear infections include: Attending day care (especially those with more than 6 children) Changes ... hands and toys often. If possible, choose a day care that has 6 or fewer children. This can ...

  17. EARS STT Overview Phil Woodland

    E-print Network

    Hain, Thomas

    EARS STT Overview Phil Woodland February 4th 2004 Cambridge University Engineering Department EARS PI Meeting: Feb 4th 2004 #12;Woodland: STT Overview Outline · STT in EARS ­ Teams & the Super Team University Engineering Department EARS PI Meeting: Feb 4th 2004 1 #12;Woodland: STT Overview ­ Martigny

  18. EARS STT Overview Phil Woodland

    E-print Network

    Hain, Thomas

    EARS STT Overview Phil Woodland February 4th 2004 Cambridge University Engineering Department EARS PI Meeting: Feb 4th 2004 Woodland: STT Overview Outline . STT in EARS -- Teams & the Super Team University Engineering Department EARS PI Meeting: Feb 4th 2004 1 #12; Woodland: STT Overview -- Martigny

  19. ANALYSIS OF ARACHIDONIC ACID METABOLITE AND PLATELET ACTIVATING FACTOR PRODUCTION

    EPA Science Inventory

    Metabolites of arachidonic acid ("eicosanoids") and platelet activating factor are important bioactive lipids that may be involved in the pathobiological alterations in animals induced by pollutant exposure. nalysis of these substances in biological tissue and fluids is important...

  20. D-2 dopamine receptor activation reduces free ( sup 3 H)arachidonate release induced by hypophysiotropic peptides in anterior pituitary cells

    SciTech Connect

    Canonico, P.L. (Univ. of Catania School of Medicine (Italy))

    1989-09-01

    Dopamine reduces the stimulation of intracellular ({sup 3}H)arachidonate release produced by the two PRL-stimulating peptides angiotensin-II and TRH. This effect is concentration dependent and is mediated by stimulation of D-2 dopamine receptors. D-2 receptor agonists (bromocriptine, dihydroergocryptine, and dihydroergocristine) inhibit the release of fatty acid induced by angiotensin-II with a potency that parallels their ability to inhibit PRL release in vitro. Conversely, the selective D-2 receptor antagonist L-sulpiride completely prevents dopamine's effect, whereas SCH 23390 (a D-1 receptor antagonist) is ineffective. The inhibitory action of dopamine does not seem to be consequent to an action on the adenylate cyclase-cAMP system, as 8-bromo-cAMP (1 mM) does not affect either basal or dopamine-inhibited ({sup 3}H)arachidonate release. However, a 24-h pertussis toxin pretreatment significantly reduces the action of dopamine on fatty acid release. Collectively, these results suggest that D-2 dopamine receptor-mediated inhibition of intracellular ({sup 3}H)arachidonate release requires the action of a GTP-binding protein, but is not a consequence of an inhibitory action on cAMP levels.

  1. Acid-Induced Gelation of Enzymatically Modified, Preheated Whey Proteins

    E-print Network

    Khan, Saad A.

    Acid-Induced Gelation of Enzymatically Modified, Preheated Whey Proteins AHMED S. EISSA AND SAAD A, and gelation (1-3). The ability of whey proteins to form gels is particularly desirable as gelation plays an essential part in dictating the texture of the final food products (4-7). Typically, gelation, which

  2. Prostaglandins regulate acid-induced cell-mediated bone resorption.

    PubMed

    Krieger, N S; Parker, W R; Alexander, K M; Bushinsky, D A

    2000-12-01

    Metabolic acidosis induces bone calcium efflux initially by physicochemical dissolution and subsequently by cell-mediated mechanisms involving inhibition of osteoblasts and stimulation of osteoclasts. In rat kidney, acidosis increases endogenous prostaglandin synthesis, and in bone, prostaglandins are important mediators of resorption. To test the hypothesis that acid-induced bone resorption is mediated by prostaglandins, we cultured neonatal mouse calvariae in neutral or physiologically acidic medium with or without 0.56 microM indomethacin to inhibit prostaglandin synthesis. We measured net calcium efflux and medium PGE(2) levels. Compared with neutral pH medium, acid medium led to an increase in net calcium flux and PGE(2) levels after both 48 h and 51 h, a time at which acid-induced net calcium flux is predominantly cell mediated. Indomethacin inhibited the acid-induced increase in both net calcium flux and PGE(2). Net calcium flux was correlated directly with medium PGE(2) (r = 0.879, n = 29, P < 0.001). Exogenous PGE(2), at a level similar to that found after acid incubation, induced net calcium flux in bones cultured in neutral medium. Acid medium also stimulated an increase in PGE(2) levels in isolated bone cells (principally osteoblasts), which was again inhibited by indomethacin. Thus acid-induced stimulation of cell-mediated bone resorption appears to be mediated by endogenous osteoblastic PGE(2) synthesis. PMID:11097626

  3. The red ear syndrome

    PubMed Central

    2013-01-01

    Red Ear Syndrome (RES) is a very rare disorder, with approximately 100 published cases in the medical literature. Red ear (RE) episodes are characterised by unilateral or bilateral attacks of paroxysmal burning sensations and reddening of the external ear. The duration of these episodes ranges from a few seconds to several hours. The attacks occur with a frequency ranging from several a day to a few per year. Episodes can occur spontaneously or be triggered, most frequently by rubbing or touching the ear, heat or cold, chewing, brushing of the hair, neck movements or exertion. Early-onset idiopathic RES seems to be associated with migraine, whereas late-onset idiopathic forms have been reported in association with trigeminal autonomic cephalalgias (TACs). Secondary forms of RES occur with upper cervical spine disorders or temporo-mandibular joint dysfunction. RES is regarded refractory to medical treatments, although some migraine preventative treatments have shown moderate benefit mainly in patients with migraine-related attacks. The pathophysiology of RES is still unclear but several hypotheses involving peripheral or central nervous system mechanisms have been proposed. PMID:24093332

  4. Ear preference in auditory perception

    Microsoft Academic Search

    M. P. Bryden

    1963-01-01

    In a dichotic listening experiment, normal adult Ss identified numbers presented to the right ear more accurately than numbers presented to the left ear and preferred to report the material from the right ear first. To evaluate the effect of order of report a further experiment was performed (N = 32) in which Ss were instructed to report each channel

  5. Ear Infections and Language Development.

    ERIC Educational Resources Information Center

    Roberts, Joanne E.; Zeisel, Susan A.

    Ear infections in infants and preschoolers can cause mild or moderate temporary hearing loss, which may in turn affect a child's ability to understand and learn language. Noting that providing children with proper medical treatment for ear infections or middle ear fluid is important in preventing possible problems with language development, this…

  6. Prostaglandin Endoperoxides. Novel Transformations of Arachidonic Acid in Human Platelets

    Microsoft Academic Search

    Mats Hamberg; Bengt Samuelsson

    1974-01-01

    Arachidonic acid incubated with human platelets was converted into three compounds, 12L-hydroxy-5,8,10,14-eicosatetraenoic acid, 12L-hydroxy-5,8,-10-heptadecatrienoic acid, and the hemiacetal derivative of 8-(1-hydroxy-3-oxopropyl)-9,12L-dihydroxy-5,10-heptadecadienoic acid. The formation of the two latter compounds from arachidonic acid proceeded by pathways involving the enzyme, fatty acid cyclo-oxygenase, in the initial step and with the prostaglandin endoperoxide, PGG2, as an intermediate. The first mentioned compound was formed

  7. Stress stimuli increase calcium-induced arachidonic acid release through phosphorylation of cytosolic phospholipase A2.

    PubMed Central

    Buschbeck, M; Ghomashchi, F; Gelb, M H; Watson, S P; Börsch-Haubold, A G

    1999-01-01

    Stress stimuli such as free radicals, high osmolarity or arsenite activate stress-activated protein kinases (SAPKs) in a wide variety of cells. In the present study, we have investigated the ability of several stress stimuli to activate SAPKs in platelets and to induce phosphorylation of their substrates. Treatment of human platelets with H(2)O(2) stimulated SAPK2a and its downstream target mitogen-activated protein kinase-activated protein kinase-2 (MAPKAP-K2). Kinase activity reached a maximum after 2-5 min and declined towards basal levels after 15 min. Arsenite caused a steady increase of MAPKAP-K2 activity up to 15 min. The level of maximal kinase activation by H(2)O(2) and arsenite was comparable with the effect caused by the physiological platelet stimulus thrombin. A high osmolarity solution of sorbitol induced comparatively small activation of SAPK2a and MAPKAP-K2. The 42-kDa extracellular signal-regulated kinase (ERK) 2 was not activated by H(2)O(2), sorbitol or arsenite. None of these stimuli triggered significant arachidonic acid release on their own. However, H(2)O(2) and sorbitol enhanced the release of arachidonic acid induced by the calcium ionophore A23187. This effect was reversed by the inhibitor of SAPK2a, 4-(4-fluorophenyl)-2-(4-methylsulphinylphenyl)-5-(4-pyridyl) imidazole (SB 203580), but not by the inhibitor of the ERK2-activating pathway, 2-(2-amino-3-methoxyphenyl)-oxanaphthalen-4-one (PD 98059). Both H(2)O(2) and sorbitol increased phosphorylation of cytosolic phospholipase A(2) (cPLA(2)) and its intrinsic activity; both responses were blocked by SB 203580. Phosphorylation of cPLA(2) by H(2)O(2) occurred on Ser-505, a reaction that is known to increase the intrinsic lipase activity of the enzyme. Our results demonstrate that activation of SAPKs by stress stimuli primes cPLA(2) activation through phosphorylation. In vivo, this mechanism would lead to the sensitization of platelet activation and may be an important risk factor in thrombotic disease. PMID:10567216

  8. Ear recognition: a complete system

    NASA Astrophysics Data System (ADS)

    Abaza, Ayman; Harrison, Mary Ann F.

    2013-05-01

    Ear Recognition has recently received significant attention in the literature. Even though current ear recognition systems have reached a certain level of maturity, their success is still limited. This paper presents an efficient complete ear-based biometric system that can process five frames/sec; Hence it can be used for surveillance applications. The ear detection is achieved using Haar features arranged in a cascaded Adaboost classifier. The feature extraction is based on dividing the ear image into several blocks from which Local Binary Pattern feature distributions are extracted. These feature distributions are then fused at the feature level to represent the original ear texture in the classification stage. The contribution of this paper is three fold: (i) Applying a new technique for ear feature extraction, and studying various optimization parameters for that technique; (ii) Presenting a practical ear recognition system and a detailed analysis about error propagation in that system; (iii) Studying the occlusion effect of several ear parts. Detailed experiments show that the proposed ear recognition system achieved better performance (94:34%) compared to other shape-based systems as Scale-invariant feature transform (67:92%). The proposed approach can also handle efficiently hair occlusion. Experimental results show that the proposed system can achieve about (78%) rank-1 identification, even in presence of 60% occlusion.

  9. Bells in Your Ears

    NSDL National Science Digital Library

    Mid-continent Research for Education and Learning (McREL)

    2004-01-01

    Does sound travel better through solids or gases? This material is part of a series of hands-on science activities designed to arouse student interest. Here the student hangs a metal fork from a pencil using string, and then strikes the fork while the eraser end of the pencil is in his or her ear. The activity includes a description, a list of science process skills and complex reasoning strategies being used, and a compilation of applicable national science standards for grades K-12. Also provided are content topics, a list of necessary supplies, instructions to perform the activity, and presentation techniques. The activity's content is explained, and assessment suggestions are provided.

  10. Bionic ear imaging

    Microsoft Academic Search

    R. Cerini; N. Faccioli; M. Barillari; M. De Iorio; M. Carner; V. Colletti; R. Pozzi Mucelli

    2008-01-01

    Purpose  The aim of this study was to illustrate the different imaging features of middle and inner ear implants, brainstem implants\\u000a and inferior colliculus implants.\\u000a \\u000a \\u000a \\u000a Materials and methods  We retrospectively reviewed the computed tomography (CT) images of 468 patients with congenital or acquired transmissive or\\u000a neurosensory hearing loss who underwent surgery. The implants examined were: 22 Vibrant Soundbridge implants, 5 at the

  11. Chronic clozapine reduces rat brain arachidonic acid metabolism by reducing plasma arachidonic acid availability

    PubMed Central

    Modi, Hiren R.; Taha, Ameer Y.; Kim, Hyung-Wook; Chang, Lisa; Rapoport, Stanley I.; Cheon, Yewon

    2012-01-01

    Chronic administration of mood stabilizers to rats downregulates the brain arachidonic acid (AA) cascade. This downregulation may explain their efficacy against bipolar disorder (BD), in which brain AA cascade markers are elevated. The atypical antipsychotics, olanzapine (OLZ) and clozapine (CLZ), also act against BD. When given to rats, both reduce brain cyclooxygenase activity and prostaglandin E2 concentration; OLZ also reduces rat plasma unesterified and esterified AA concentrations, and AA incorporation and turnover in brain phospholipid. To test whether CLZ produces similar changes, we used our in vivo fatty acid method in rats given 10 mg/kg/day i.p. CLZ, or vehicle, for 30 days; or 1 day after CLZ washout. [1-14C]AA was infused intravenously for 5 min, arterial plasma was collected and microwaved brain was analyzed. CLZ increased incorporation coefficients ki? and rates Jin,i of plasma unesterified AA into brain phospholipids i, while decreasing plasma unesterified but not esterified AA. These effects disappeared after washout. Thus, CLZ and OLZ similarly downregulated kinetics and cyclooxygenase expression of the brain AA cascade, likely by reducing plasma unesterified AA availability. Atypical antipsychotics and mood stabilizers may be therapeutic in BD by downregulating, indirectly or directly respectively, the elevated brain AA cascade of that disease. PMID:23121637

  12. Beware of dogs licking ears.

    PubMed

    Godey, B; Morandi, X; Bourdinière, J; Heurtin, C

    1999-10-01

    A patient with right-sided chronic purulent otorrhoea developed meningitis due to Pasteurella multocida transmitted by a dog that frequently licked his ear. We suggest that patients with a perforated tympanic membrane should avoid being licked on their ears by animals. PMID:10520644

  13. Shape and Structural Feature Based Ear Recognition

    Microsoft Academic Search

    Zhichun Mu; Li Yuan; Zhengguang Xu; Dechun Xi; Shuai Qi

    2004-01-01

    \\u000a Application and research of ear recognition technology is a new subject in the field of biometric recognition. The earlier\\u000a research has shown that human ear is one of the representative human biometrics with uniqueness and stability. The paper discusses\\u000a the edge-based ear recognition method including ear edge detection, ear description and feature extraction, recognition method\\u000a and ear database construction. The

  14. Surgical correction of constricted ear combined with Stahl's ear.

    PubMed

    Bi, Ye; Lin, Lin; Yang, Qinhua; Pan, Bo; Zhao, Yanyong; He, Leren; Jiang, Haiyue

    2015-07-01

    Constricted ear combined with Stahl's ear is a rare ear deformity, which is a kind of complex congenital auricular deformity. From 1 January 2007 to 1 January 2014, 19 patients with constricted ear combined with Stahl's ear (Spock ear) were enrolled in this study, most of which were unilaterally deformed. To correct the deformity, a double Z-shaped skin incision was made on the posterior side of the auricle, with the entire layer of cartilage cut parallel to the helix traversing the third crus to form a fan-shaped cartilage flap. The superior crura of the antihelix were shaped by the folding cartilage rim. The cartilage of the abnormal third crus was made part of the new superior crura of antihelix, and the third crus was eliminated. The postoperative aesthetic assessment of the reshaped auricle was graded by both doctors and patients (or their parents). Out of the 19 patients, the number of satisfying cases of the symmetry, helix stretch, elimination of the third crus, the cranioauricular angle, and the substructure of the reshaped ears was 14 (nine excellent and five good), 16 (six excellent and 10 good), 17 (eight excellent and nine good), 15 (five excellent and 10 good), and 13 (two excellent and 11 good), respectively. With a maximum of a 90-month follow-up, no complication was observed. The results of the study suggested that this rare deformity could be corrected by appropriate surgical treatment, with a satisfied postoperative appearance. PMID:25921912

  15. Arachidonic acid in aquaculture feeds: current status and future opportunities

    Microsoft Academic Search

    J. Gordon Bell; John R. Sargent

    2003-01-01

    The importance of arachidonic acid (20:4n?6, ARA) in fish nutrition has tended to be overlooked in preference to eicosapentaenoic (20:5n?3, EPA) and docosahexaenoic acids (22:6n?3, DHA), probably due to the predominance of the latter two HUFA in fish tissues. However, despite the abundance of EPA and DHA in fish tissues, the importance of ARA as the primary eicosanoid precursor has

  16. Isolation of natural arachidonic acid as its methyl ester

    Microsoft Academic Search

    S. F. Herb; R. W. Riemenschneider; Jeanette Donaldson

    1951-01-01

    Summary  Fresh beef suprarenal glands were ground and extracted thoroughly with alcohol and then with ethyl ether. After removal of\\u000a solvent the total lipid residue was saponified, and the fatty acids were recovered by extraction. The less unsaturated acids\\u000a were removed by crystallization from acetone at ?40C. At this stage the filtrate contained essentially all the arachidonic\\u000a acid originally present in

  17. Increased isoprostane levels in oleic acid-induced lung injury

    SciTech Connect

    Ono, Koichi [Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, Matsumoto (Japan)] [Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, Matsumoto (Japan); Koizumi, Tomonobu, E-mail: tomonobu@shinshu-u.ac.jp [First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto (Japan)] [First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto (Japan); Tsushima, Kenji; Yoshikawa, Sumiko; Yokoyama, Toshiki [First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto (Japan)] [First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto (Japan); Nakagawa, Rikimaru [Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, Matsumoto (Japan)] [Department of Anesthesiology and Resuscitation, Shinshu University School of Medicine, Matsumoto (Japan); Obata, Toru [Department of Molecular Cell Biology, Institute of DNA Medicine, Jikei University School of Medicine, Tokyo (Japan)] [Department of Molecular Cell Biology, Institute of DNA Medicine, Jikei University School of Medicine, Tokyo (Japan)

    2009-10-16

    The present study was performed to examine a role of oxidative stress in oleic acid-induced lung injury model. Fifteen anesthetized sheep were ventilated and instrumented with a lung lymph fistula and vascular catheters for blood gas analysis and measurement of isoprostanes (8-epi prostaglandin F2{alpha}). Following stable baseline measurements, oleic acid (0.08 ml/kg) was administered and observed 4 h. Isoprostane was measured by gas chromatography mass spectrometry with the isotope dilution method. Isoprostane levels in plasma and lung lymph were significantly increased 2 h after oleic acid administration and then decreased at 4 h. The percent increases in isoprostane levels in plasma and lung lymph at 2 h were significantly correlated with deteriorated oxygenation at the same time point, respectively. These findings suggest that oxidative stress is involved in the pathogenesis of the pulmonary fat embolism-induced acute lung injury model in sheep and that the increase relates with the deteriorated oxygenation.

  18. Valproic acid induces caspase 3-mediated apoptosis in microglial cells.

    PubMed

    Dragunow, M; Greenwood, J M; Cameron, R E; Narayan, P J; O'Carroll, S J; Pearson, A G; Gibbons, H M

    2006-07-21

    Valproic acid is widely used for the treatment of epilepsy and mood disorders, but its mode of action is unclear. Treatment of neuronal cells with valproic acid promotes neurite sprouting, is neuroprotective and drives neurogenesis; however its effects on non-neuronal brain cells are less clear. We report that valproic acid induces apoptosis in the mouse microglial cell line, BV-2, at concentrations within the therapeutic range. When BV-2 cells were incubated for 24 h with 500-1000 microM valproic acid we observed a reduction in cell number, the appearance of apoptotic morphology and increased caspase 3 cleavage. Exposure of a macrophage cell line (RAW 264.7) to similar concentrations of valproic acid also led to reduced cell number but no caspase 3 cleavage, suggesting these cells responded to valproic acid with reduced proliferation rather than apoptosis. This was confirmed using bromodeoxyuridine incorporation studies. Similar concentrations of valproic acid added to Neuro-2a, SK-N-SH and C6 cell lines as well as human NTera-2 astrocytes did not evoke cell death. The caspase 3 inhibitor DEVD-CHO inhibited valproic acid-induced apoptosis in BV-2 cells whereas the MEK inhibitor U0126 potentiated valproic acid-mediated apoptosis. These results demonstrate that valproic acid selectively induces apoptosis in BV-2 cells by way of a caspase 3-mediated action. As activated microglia secrete neurotoxins in neurodegenerative diseases such as Alzheimer's, Parkinson's, and HIV dementia, valproic acid may alleviate these diseases by selectively killing microglia. PMID:16600518

  19. Hearing, Ear Infections, and Deafness

    MedlinePLUS

    ... with hearing loss Ear Infections — facts for parents Communication Methods & Devices for People With Hearing Loss American ... Into Health ® National Institute on Deafness and Other Communication Disorders 31 Center Drive, MSC 2320, Bethesda, MD ...

  20. Middle-Ear Pressure Under Basal Conditions

    E-print Network

    Allen, Jont

    Middle-Ear Pressure Under Basal Conditions Leif Hergils, MD, Bengt Magnuson, MD, PhD \\s=b\\Spontaneous pressure changes in the middle ear were measured under bas- al conditions in ten subjects with healthy ears. Results showed that the pressure in the majority of ears remained slightly above the atmo- spheric

  1. Wonder Ears: Identification of Identical Twins from Ear Images Hossein Nejati

    E-print Network

    Sim, Terence

    system [14] including automated segmentation of the ear in a pro- file view image and 3D shape matchingWonder Ears: Identification of Identical Twins from Ear Images Hossein Nejati , Li Zhang ,Terence explored automatic ear recognition for identical twin identification. Ear image recognition has been stud

  2. Cortisol inhibits acid-induced bone resorption in vitro.

    PubMed

    Krieger, Nancy S; Frick, Kevin K; Bushinsky, David A

    2002-10-01

    Metabolic acidosis increases urine calcium excretion without an increase in intestinal calcium absorption, resulting in a net loss of bone mineral. In vitro, metabolic acidosis has been shown to initially induce physicochemical mineral dissolution and then enhance cell-mediated bone resorption. Acidic medium stimulates osteoblastic prostaglandin E(2) production, which mediates the subsequent stimulation of osteoclastic bone resorption. Glucocorticoids are also known to decrease bone mineral density, and metabolic acidosis has been shown to increase glucocorticoid production. This study tested the hypothesis that glucocorticoids would exacerbate acid-induced net calcium efflux from bone. Neonatal mouse calvariae were cultured in acid (Acid; pH = 7.06 +/- 0.01; [HCO(3)(-)] = 10.6 +/- 0.3 mM) or neutral (Ntl; pH = 7.43 +/- 0.01; [HCO(3)(-)] = 26.2 +/- 0.5 mM) medium, with or without 1 microM cortisol (Cort), and net calcium efflux and medium prostaglandin E(2) (PGE(2)) levels and osteoclastic beta-glucuronidase activity were determined. Compared with Ntl, Cort alone decreased calcium efflux, medium PGE(2), and osteoclast activity; Acid led to an increase in all three parameters. The addition of Cort to Acid led to a reduction of calcium efflux, medium PGE(2) levels and beta-glucuronidase activity compared with Acid alone. There was a significant direct correlation between medium PGE(2) concentration and net calcium efflux (r = 0.944; n = 23; P < 0.0001), between osteoclastic beta-glucuronidase activity and net calcium efflux (r = 0.663; n = 40; P < 0.001), and between medium PGE(2) concentration and beta-glucuronidase activity (r = 0.976; n = 4; P < 0.01). Thus, in vitro cortisol inhibits acid-induced, cell-mediated osteoclastic bone resorption through a decrease in osteoblastic PGE(2) production. These results suggest that the osteopenia observed in response to metabolic acidosis in vivo is not due to an increase in endogenous cortisol production. PMID:12239242

  3. Arachidonic acid enhances reproduction in Daphnia magna and mitigates changes in sex ratios induced by pyriproxyfen.

    PubMed

    Ginjupalli, Gautam K; Gerard, Patrick D; Baldwin, William S

    2015-03-01

    Arachidonic acid is 1 of only 2 unsaturated fatty acids retained in the ovaries of crustaceans and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. The authors hypothesized that, as a key fatty acid, arachidonic acid may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with arachidonic acid indicate that it alters female:male sex ratios by increasing female production. This reproductive effect only occurred during a restricted Pseudokirchneriella subcapitata diet. Next, the authors tested whether enriching a poorer algal diet (Chlorella vulgaris) with arachidonic acid enhances overall reproduction and sex ratios. Arachidonic acid enrichment of a C. vulgaris diet also enhances fecundity at 1.0?µM and 4.0?µM by 30% to 40% in the presence and absence of pyriproxyfen. This indicates that arachidonic acid is crucial in reproduction regardless of environmental sex determination. Furthermore, the data indicate that P. subcapitata may provide a threshold concentration of arachidonic acid needed for reproduction. Diet-switch experiments from P. subcapitata to C. vulgaris mitigate some, but not all, of arachidonic acid's effects when compared with a C. vulgaris-only diet, suggesting that some arachidonic acid provided by P. subcapitata is retained. In summary, arachidonic acid supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in arachidonic acid may provide protection from some reproductive toxicants such as the juvenile hormone agonist pyriproxyfen. Environ Toxicol Chem 2015;34:527-535. © 2014 SETAC. PMID:25393616

  4. Computerized image analysis for acetic acid induced intraepithelial lesions

    NASA Astrophysics Data System (ADS)

    Li, Wenjing; Ferris, Daron G.; Lieberman, Rich W.

    2008-03-01

    Cervical Intraepithelial Neoplasia (CIN) exhibits certain morphologic features that can be identified during a visual inspection exam. Immature and dysphasic cervical squamous epithelium turns white after application of acetic acid during the exam. The whitening process occurs visually over several minutes and subjectively discriminates between dysphasic and normal tissue. Digital imaging technologies allow us to assist the physician analyzing the acetic acid induced lesions (acetowhite region) in a fully automatic way. This paper reports a study designed to measure multiple parameters of the acetowhitening process from two images captured with a digital colposcope. One image is captured before the acetic acid application, and the other is captured after the acetic acid application. The spatial change of the acetowhitening is extracted using color and texture information in the post acetic acid image; the temporal change is extracted from the intensity and color changes between the post acetic acid and pre acetic acid images with an automatic alignment. The imaging and data analysis system has been evaluated with a total of 99 human subjects and demonstrate its potential to screening underserved women where access to skilled colposcopists is limited.

  5. Nucleic acid-induced antiviral immunity in shrimp.

    PubMed

    Wang, Pei-Hui; Yang, Li-Shi; Gu, Zhi-Hua; Weng, Shao-Ping; Yu, Xiao-Qiang; He, Jian-Guo

    2013-09-01

    Vertebrates detect viral infection predominantly by sensing viral nucleic acids to produce type I interferon (IFN). In invertebrates, it has been believed that the IFN system is absent and RNA interference is a sequence-specific antiviral pathway. In this study, we found that injection of nucleic acid mimics poly(I:C), poly(C:G), CL097, poly C and CpG-DNA, afforded shrimp antiviral immunity, which is similar to the vertebrate IFN system. Using suppression subtractive hybridization (SSH) method, 480 expression sequence tags were identified to be involved in the poly(I:C)-induced antiviral immunity of the model crustacean Litopenaeus vannamei, and 41% of them were new genes. In the SSH libraries, several IFN system-related genes such as dsRNA-dependent protein kinase PKR, Toll-like receptor 3 (TLR3) and IFN?-inducible protein 30 were identified. L. vannamei IKK?, whose vertebrate homologs are central regulators of the IFN-producing pathway, could significantly activate IFN reporter genes in HEK293T cells. In crustacean databases, many genes homologous to genes of the vertebrate IFN response, such as IRFs, PKR, ADAR (adenosine deaminase, RNA-specific) and other interferon-stimulated genes (ISGs) were discovered. These results suggest that shrimp may possess nucleic acid-induced antiviral immunity. PMID:23773856

  6. Epidemiology of Fusarium Diseases and their Mycotoxins in Maize Ears

    Microsoft Academic Search

    Gary P. Munkvold

    2003-01-01

    Fusarium species cause two distinct diseases on ears of maize, Fusarium ear rot (or pink ear rot) and Gibberella ear rot (or red ear rot), both of which can result in mycotoxin contamination of maize grain. The primary causal agent for Fusarium ear rot is Fusarium verticillioides, but F. subglutinans and F. proliferatum are also important. Gibberella ear rot is

  7. 3D Printed Bionic Ears

    PubMed Central

    Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C.

    2013-01-01

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  8. 3D printed bionic ears.

    PubMed

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

    2013-06-12

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  9. Hyperglycemia-Induced Teratogenesis is Mediated by a Functional Deficiency of Arachidonic Acid

    Microsoft Academic Search

    Allen S. Goldman; Lester Baker; Ronald Piddington; Barry Marx; Richard Herold; Joseph Egler

    1985-01-01

    Congenital malformations now represent the largest single cause of mortality in the infant of the diabetic mother. The mechanism by which diabetes exerts its teratogenic effects is not known. This study evaluated whether arachidonic acid might be involved, a possibility raised by the role of arachidonic acid in palatal elevation and fusion, processes analogous to neural tube folding and fusion.

  10. Arachidonic Acid Enhances Turnover of the Dermal Skeleton: Studies on Zebrafish Scales

    PubMed Central

    de Vrieze, Erik; Moren, Mari; Metz, Juriaan R.; Flik, Gert; Lie, Kai Kristoffer

    2014-01-01

    In fish nutrition, the ratio between omega-3 and omega-6 poly-unsaturated fatty acids influences skeletal development. Supplementation of fish oils with vegetable oils increases the content of omega-6 fatty acids, such as arachidonic acid in the diet. Arachidonic acid is metabolized by cyclooxygenases to prostaglandin E2, an eicosanoid with effects on bone formation and remodeling. To elucidate effects of poly-unsaturated fatty acids on developing and existing skeletal tissues, zebrafish (Danio rerio) were fed (micro-) diets low and high in arachidonic acid content. Elasmoid scales, dermal skeletal plates, are ideal to study skeletal metabolism in zebrafish and were exploited in the present study. The fatty acid profile resulting from a high arachidonic acid diet induced mild but significant increase in matrix resorption in ontogenetic scales of adult zebrafish. Arachidonic acid affected scale regeneration (following removal of ontogenetic scales): mineral deposition was altered and both gene expression and enzymatic matrix metalloproteinase activity changed towards enhanced osteoclastic activity. Arachidonic acid also clearly stimulates matrix metalloproteinase activity in vitro, which implies that resorptive effects of arachidonic acid are mediated by matrix metalloproteinases. The gene expression profile further suggests that arachidonic acid increases maturation rate of the regenerating scale; in other words, enhances turnover. The zebrafish scale is an excellent model to study how and which fatty acids affect skeletal formation. PMID:24586706

  11. Arachidonic acid enhances turnover of the dermal skeleton: studies on zebrafish scales.

    PubMed

    de Vrieze, Erik; Moren, Mari; Metz, Juriaan R; Flik, Gert; Lie, Kai Kristoffer

    2014-01-01

    In fish nutrition, the ratio between omega-3 and omega-6 poly-unsaturated fatty acids influences skeletal development. Supplementation of fish oils with vegetable oils increases the content of omega-6 fatty acids, such as arachidonic acid in the diet. Arachidonic acid is metabolized by cyclooxygenases to prostaglandin E2, an eicosanoid with effects on bone formation and remodeling. To elucidate effects of poly-unsaturated fatty acids on developing and existing skeletal tissues, zebrafish (Danio rerio) were fed (micro-) diets low and high in arachidonic acid content. Elasmoid scales, dermal skeletal plates, are ideal to study skeletal metabolism in zebrafish and were exploited in the present study. The fatty acid profile resulting from a high arachidonic acid diet induced mild but significant increase in matrix resorption in ontogenetic scales of adult zebrafish. Arachidonic acid affected scale regeneration (following removal of ontogenetic scales): mineral deposition was altered and both gene expression and enzymatic matrix metalloproteinase activity changed towards enhanced osteoclastic activity. Arachidonic acid also clearly stimulates matrix metalloproteinase activity in vitro, which implies that resorptive effects of arachidonic acid are mediated by matrix metalloproteinases. The gene expression profile further suggests that arachidonic acid increases maturation rate of the regenerating scale; in other words, enhances turnover. The zebrafish scale is an excellent model to study how and which fatty acids affect skeletal formation. PMID:24586706

  12. Source of the arachidonic acid released on stimulation of rat basophilic leukemia cells

    SciTech Connect

    Garcia-Gil, M.; Siraganian, R.P.

    1986-05-15

    Triggering of rat basophilic leukemia cells for histamine secretion is accompanied by arachidonic acid release. The source of this arachidonic acid released after IgE or calcium ionophore A23187 stimulation was studied. The 48-hr culture of the cells with (/sup 14/C)arachidonic acid resulted in labeling of the phospholipids to constant specific activity. After IgE stimulation, 8.8% of the cellular (/sup 14/C)arachidonate was released; this was predominantly from phosphatidylinositol (PI)/phosphatidylserine (PS) (66.3%), less from phosphatidylethanolamine (PE) (25.9%), and minimally from phosphatidylcholine (PC). In contrast, after ionophore stimulation the cells released 16.4% of cellular (/sup 14/C)arachidonate, most of this was from PE (55.4%) followed by about equal amounts from PS/PI and PC (24% and 20%, respectively). Therefore, the source of the released arachidonic acid depends on the stimulus. In contrast, the results are different when the cells are cultured for only 2 hr with (/sup 14/C)arachidonic acid. The label in phospholipids was in PC (44%), PE (38%), and PI/PS (20%); the stimulation of the cells with IgE or ionophore resulted in the release of the (/sup 14/C)arachidonate from PC (81% and 96%, respectively). This suggests the presence of several pools of phospholipids that are labeled at different rates and have variable proximity and/or accessibility to the phospholipase(s) enzyme(s) activated during cell secretion.

  13. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate

    Microsoft Academic Search

    Patrick Hannaert; Miriam Alvarez-Guerra; Hamida Hider; Carlo Chiavaroli; Ricardo P Garay

    2003-01-01

    The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into

  14. Oxidation of esterified arachidonate by rat liver microsomes

    SciTech Connect

    Davis, H.W.; Suzuki, T.; Schenkman, J.B.

    1986-03-05

    The authors have previously demonstrated a relationship between phospholipid arachidonate in liver microsomes and malondialdehyde (MDA) formation during lipid peroxidation. In this study arachidonic acid (U-/sup 14/C) was incorporated into rat liver microsomes and NADPH-supported peroxidation was carried out at 37/sup 0/C for 15 minutes. The microsomes were pelleted by centrifugation and the labeled products in the supernatant were isolated by a solid phase method. Pellets were hydrolyzed with phospholipase A/sub 2/ and extracted with diethyl ether and the products from both fractions were separated by reverse phase HPLC. The results show that (1) oxidation occurs in all of the major phospholipids but that phosphatidylethanolamine is the most susceptible; (2) a linear correlation exists between MDA formation and supernatant radioactivity; (3) several different polar products are found in both the supernatant and the hydrolyzed pellet but that the ratios of product peaks in HPLC do not change during the peroxidation, indicating no secondary metabolism or propagation; and (4) cytochrome P-450 is not involved in the peroxidative reactions since no oxidation occurs in the absence of Fe/sup 3 +/ and since product formation is unaffected in the presence of carbon monoxide.

  15. A biomechanical ear model to evaluate middle-ear reconstruction.

    PubMed

    Mojallal, Hamidreza; Stieve, Martin; Krueger, Ilka; Behrens, Peter; Mueller, Peter P; Lenarz, Thomas

    2009-12-01

    In order to evaluate the efficiency of middle-ear prostheses in near-real conditions, an artificial model was developed that approximately simulates the actual geometrical and biomechanical properties of the ear system (excluding the ossicular chain). The sound transmission characteristics of selected commercial middle-ear prostheses and of a synthetic test material were measured using laser Doppler vibrometry (LDV) in this model. The model's realistic properties enabled clinical tympanometry to be used to control the stiffness. In addition the influences of the implant mass on transmission characteristics were investigated. With an averaged displacement between 10 and 100 nm/Pa up to 2000 Hz, the transmission characteristic of the model was comparable with data obtained from the intact middle ear in temporal bone experiments. From the acoustical point of view, no significant material-specific differences could be found. Increasing the mass of the implants to more than 50 mg results in poorer acoustic transmission. In general, changes to the stiffness involving compliance values greater than 3.5 ml and smaller than 0.2 ml led to poorer acoustic transmission. PMID:20017684

  16. MICROARRAY ANALYSIS OF DICHLOROACETIC ACID-INDUCED CHANGES IN GENE EXPRESSION

    EPA Science Inventory

    MICROARRAY ANALYSIS OF DICHLOROACETIC ACID-INDUCED CHANGES IN GENE EXPRESSION Dichloroacetic acid (DCA) is a major by-product of water disinfection by chlorination. Several studies have demonstrated the hepatocarcinogenicity of DCA in rodents when administered in dri...

  17. Structure and rheological properties of acid-induced egg white protein gels

    Microsoft Academic Search

    Mireille Weijers; Fred van de Velde; Ann Stijnman; Anne van de Pijpekamp; Ronald W. Visschers

    2006-01-01

    This study compares the rheological properties of acid-induced gels prepared of industrial spray-dried egg white proteins (EWP) with the acid-induced gels prepared of ovalbumin (OA) and whey protein isolate (WPI). Also we aimed to form transparent gels of EWP by means of the cold-gelation process. We showed that it was not possible to prepare cold-set gels because ovotransferrin (OT), present

  18. Sulfasalazine reduces bile acid induced apoptosis in human hepatoma cells and perfused rat livers

    Microsoft Academic Search

    C Rust; K Bauchmuller; C Bernt; T Vennegeerts; P Fickert; A Fuchsbichler; U Beuers

    2006-01-01

    Background: Bile acid induced apoptosis in hepatocytes can be antagonised by nuclear factor ?B (NF?B) dependent survival pathways. Sulfasalazine modulates NF?B in different cell types. We aimed to determine the effects of sulfasalazine and its metabolites sulfapyridine and 5-aminosalicylic acid (5-ASA) on bile acid induced apoptosis in hepatocytes.Methods: Apoptosis was determined by caspase assays and immunoblotting, NF?B activation by electrophoretic

  19. Neurosensory Development in the Zebrafish Inner Ear 

    E-print Network

    Vemaraju, Shruti

    2012-02-14

    The vertebrate inner ear is a complex structure responsible for hearing and balance. The inner ear houses sensory epithelia composed of mechanosensory hair cells and non-sensory support cells. Hair cells synapse with neurons of the VIIIth cranial...

  20. Neurosensory Development in the Zebrafish Inner Ear

    E-print Network

    Vemaraju, Shruti

    2012-02-14

    The vertebrate inner ear is a complex structure responsible for hearing and balance. The inner ear houses sensory epithelia composed of mechanosensory hair cells and non-sensory support cells. Hair cells synapse with neurons of the VIIIth cranial...

  1. The caecilian ear: further observations.

    PubMed

    Wever, E G; Gans, C

    1976-10-01

    The structure of the ear is examined in two species of caecilians, Ichthyophis glutinosus and I. orthoplicatus, and the sensitivity to aerial sounds is assessed in terms of the electrical potentials of the cochlea. The results are in general agreement with previous reports on other caecilian species. PMID:1068485

  2. Tumors of the ear canal.

    PubMed

    Rogers, K S

    1988-07-01

    This discussion will focus on the clinical presentation, diagnostic evaluation, expected biologic behavior, and therapeutic options for tumours of the ear canal in the dog and cat. Particular emphasis will be placed on neoplasia of the ceruminous glands, squamous cell carcinoma, and non-neoplastic mass lesions. PMID:3264960

  3. Surgery of the ear and pinna.

    PubMed

    Lanz, Otto I; Wood, Brett C

    2004-03-01

    There are several disease processes of the ear and pinna that warrant surgical intervention. This article reviews surgical anatomy and common surgical procedures of the ear and pinna, including aural hematomas, lateral wall resection, vertical ear canal resection, total ear canal ablation and lateral bulla osteotomy, partial pinna resection, and feline inflammatory polyps. The clinical signs, diagnosis, and surgical treatment along with potential complications for each disease process are discussed. PMID:15062625

  4. Ear Recognition Based on Gabor Features and KFDA

    PubMed Central

    Mu, Zhichun

    2014-01-01

    We propose an ear recognition system based on 2D ear images which includes three stages: ear enrollment, feature extraction, and ear recognition. Ear enrollment includes ear detection and ear normalization. The ear detection approach based on improved Adaboost algorithm detects the ear part under complex background using two steps: offline cascaded classifier training and online ear detection. Then Active Shape Model is applied to segment the ear part and normalize all the ear images to the same size. For its eminent characteristics in spatial local feature extraction and orientation selection, Gabor filter based ear feature extraction is presented in this paper. Kernel Fisher Discriminant Analysis (KFDA) is then applied for dimension reduction of the high-dimensional Gabor features. Finally distance based classifier is applied for ear recognition. Experimental results of ear recognition on two datasets (USTB and UND datasets) and the performance of the ear authentication system show the feasibility and effectiveness of the proposed approach. PMID:24778595

  5. Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals

    E-print Network

    Allen, Jont

    Effects of Middle-Ear Disorders on Power Reflectance Measured in Cadaveric Ear Canals Susan E. Voss,1 Gabrielle R. Merchant,2 and Nicholas J. Horton3 Objective: Reflectance measured in the ear canal offers a noninvasive method to monitor the acoustic properties of the middle ear, and few systematic

  6. Ear Modeling and Sound Signal Processing Ear modeling can significantly improve sound signal processing and

    E-print Network

    Xin, Jack

    Ear Modeling and Sound Signal Processing Jack Xin Abstract Ear modeling can significantly improve sound signal processing and the design of hearing devices. Ear models based on mechanics and neu- ral phenomenology of the inner ear (cochlea) form a class of nonlinear nonlocal dispersive partial differential

  7. Immunologic Disorders of the Inner Ear.

    ERIC Educational Resources Information Center

    Kinney, William C.; Hughes, Gordon B.

    1997-01-01

    Immune inner ear disease represents a series of immune system mediated problems that can present with hearing loss, dizziness, or both. The etiology, presentation, testing, and treatment of primary immune inner ear disease is discussed. A review of secondary immune inner ear disease is presented for comparison. (Contains references.) (Author/CR)

  8. Ear Biometrics in Human Identification A Dissertation

    E-print Network

    Bowyer, Kevin W.

    Ear Biometrics in Human Identification A Dissertation Submitted to the Graduate School and Engineering Notre Dame, Indiana June 2006 #12;Ear Biometrics in Human Identification Abstract by Ping Yan the ear as a biometric and investigate its potential with both 2D and 3D data. Our work is the largest

  9. EAR TO THE GROUND IN THIS ISSUE

    E-print Network

    EAR TO THE GROUND IN THIS ISSUE Update from the Division Director 1 New Program Officer Dr. Jonathan Wynn 2 Meet the EAR Staff 3 Broader Impacts ­ Examples from the Ground 3 The Division of Earth Sciences (EAR) is part of the Geosciences Directorate at the National Science Foundation. News from

  10. Significance of arachidonic acid in ocular infections and inflammation

    PubMed Central

    Tripathi, Trivendra

    2015-01-01

    Innate immune responses in the cornea mainly play an important role to mobilize multiple interrelated pathways of corneal lipid, which involve in inflammatory corneal diseases. Signaling lipid mediators derived from arachidonic acid (AA) control cell proliferation, apoptosis, metabolism, and migration, are known as eicosanoids, phosphoinositides, sphingolipids, and fatty acids. Emerging evidences have highlighted the implication of lipid mediators in both injury and repair mechanisms in the cornea. Recently, the role of AA and its metabolites to induce proinflammatory mediators and inflammatory cell infiltration in the pathogen-infected cornea and to cause severe keratitis have been revealed. In this review, we focus on the novel roles of AA downstream signaling in the corneal inflammatory diseases and also the biological relevance of AA signaling in the therapeutic strategies for targeting sight-threatening diseases.

  11. The Effect of Ear Canal Pressure on Spontaneous Otoacoustic Emissions:. Comparison Between Human and Lizard Ears

    NASA Astrophysics Data System (ADS)

    van Dijk, P.; Manley, G. A.

    2009-02-01

    The center frequency, height and width of peaks in SOAE spectra depend on ear canal pressure. The width is interpreted as a measure of the inner ear source-signal-to-(e.g. thermal)-noise ratio. In humans, width increases with decreasing height. Apparently, ear canal pressure modifies the amplitude of the inner ear emission source signal. In lizards, the relation between peak width and height is not consistent. Here, middle ear transmission changes may account for many the observed amplitude effects.

  12. A simple ear splint for microtia patients.

    PubMed

    Venkata Krishnan, C J; Balaji, S M; Jain, Ashish R

    2015-01-01

    Microtia is a congenital anomaly of the ear can occur as an isolated birth defect or as part of a spectrum of anomalies or as a syndrome. Microtia is often associated with impaired hearing and or total loss of hearing. Such patients typically require treatment for surgical ear reconstruction and for hearing impairment. Maintenance of ear projection and post auricular sulcus in staged ear reconstruction in microtia is a trying problem. So also is the maintenance of the patency of the external auditory meatus following recanalization and meatoplasty.This case report describes a simple effective way of fabrication of ear splint prosthesis. PMID:26096122

  13. Tranexamic acid induces kaolin intake stimulating a pathway involving tachykinin neurokinin 1 receptors in rats.

    PubMed

    Kakiuchi, Hitoshi; Kawarai-Shimamura, Asako; Kuwagata, Makiko; Orito, Kensuke

    2014-01-15

    Tranexamic acid suppresses post-partum haemorrhage and idiopathic menorrhagia through its anti-fibrinolytic action. Although it is clinically useful, it is associated with high risks of side effects such as emesis. Understanding the mechanisms underlying tranexamic acid-induced emesis is very important to explore appropriate anti-emetic drugs for the prevention and/or suppression of emesis. In this study, we examined the receptors involved in tranexamic acid-induced kaolin intake in rats, which reflects the drug's clinical emetogenic potential in humans. Further, we examined the brain regions activated by administration of tranexamic acid and elucidated pivotal pathways of tranexamic acid-induced kaolin intake. We examined the effects of ondansetron, a 5-hydroxytryptamine 3 receptor antagonist, domperidone, a dopamine 2 receptor antagonist, and aprepitant, a tachykinin neurokinin 1 (NK1) receptor antagonist, on tranexamic acid-induced kaolin intake in rats. Then, we determined the brain regions that showed increased numbers of c-Fos immunoreactive cells. Finally, we examined the effects of an antagonist(s) that reduced tranexamic acid-induced kaolin intake on the increase in c-Fos immunoreactive cells. Aprepitant significantly decreased tranexamic acid-induced kaolin intake. However, neither ondansetron nor domperidone decreased kaolin intake. Tranexamic acid significantly increased c-Fos immunoreactive cells by approximately 5.5-fold and 22-fold in the area postrema and nucleus of solitary tract, respectively. Aprepitant decreased the number of c-Fos immunoreactive cells in both areas. Tranexamic acid induced kaolin intake possibly via stimulation of tachykinin NK1 receptors in rats. The tachykinin NK1 receptor could be targeted to prevent and/or suppress emesis in patients receiving tranexamic acid. PMID:24333477

  14. Inner ear deficits after chronic otitis media.

    PubMed

    Chang, Chun-Wei; Cheng, Po-Wen; Young, Yi-Ho

    2014-08-01

    Investigation of the causes of vestibular symptoms in patients with chronic otitis media (COM) faces frustration, mainly because the bithermal caloric test using tap water is generally contraindicated in perforated ears. This study utilized audiometry, ocular vestibular-evoked myogenic potential (oVEMP) test, and cervical VEMP (cVEMP) test to evaluate inner ear deficits after COM. A total of 85 COM patients (117 ears) underwent otoscopy, image study, audiometry, oVEMP test, and cVEMP test. Mean bone-conducted (BC) hearing threshold ?25 dB was observed in 74 ears, 26-40 dB in 30 ears, and >40 dB in 13 ears. Restated, abnormal BC hearing threshold was identified in 43 ears (37 %). Percentages of abnormal cVEMP test, oVEMP test, and BC hearing threshold in 117 COM ears were 65, 62, and 37 %, respectively, exhibiting a significantly declining sequence in inner ear function. Furthermore, cVEMP/oVEMP test results were significantly correlated with BC hearing threshold, whereas no correlation existed between the cVEMP and oVEMP test results. In conclusion, the sequence of inner ear deficits after COM runs from the saccule/utricle to the cochlea and semicircular canals. Restated, in addition to BC hearing test, the cVEMP/oVEMP test may serve as a supplementary tool for early detection of inner ear involvement in COM patients. PMID:24061573

  15. The War of Jenkins’ Ear

    PubMed Central

    Graboyes, Evan M.; Hullar, Timothy E.

    2012-01-01

    Objective In 1731, Spanish sailors boarded the British brig Rebecca off the coast of Cuba and sliced off the left ear of its captain, Robert Jenkins. This traumatic auriculectomy was used as a pretext by the British to declare war on Spain in 1739, a conflict that is now known as the War of Jenkins’ Ear. Here, we examine the techniques available for auricular repair at the time of Jenkins’ injury and relate them to the historical events surrounding the incident. Methods Review of relevant original published manuscripts and monographs. Results Surgeons in the mid-18th century did not have experience with repair of traumatic total auriculectomies. Some contemporary surgeons favored auricular prostheses over surgical treatment. Methods for the reconstruction of partial defects were available, and most authors advocated a local post-auricular flap instead of a free tissue transfer. Techniques for repair of defects of the auricle lagged behind those for repair of the nose. Conclusion Limitations in care of traumatic auricular defects may have intensified the significance of Jenkins’ injury and helped lead to the War of Jenkins’ Ear, but conflict between Britain and Spain was probably unavoidable due to their conflicting commercial interests in the Caribbean. PMID:23444484

  16. Docosahexaenoic acid induces apoptosis in Jurkat cells by a protein phosphatase-mediated process

    Microsoft Academic Search

    Rafat A. Siddiqui; Laura J. Jenski; Kristiana Neff; Kevin Harvey; Richard J. Kovacs; William Stillwell

    2001-01-01

    Docosahexaenoic acid (DHA) is an omega-3 fatty acid under intense investigation for its ability to modulate cancer cell growth and survival. This research was performed to study the cellular and molecular effects of DHA. Our experiments indicated that the treatment of Jurkat cells with DHA inhibited their survival, whereas similar concentrations (60 and 90 ?M) of arachidonic acid and oleic

  17. An efficient method for the purification of arachidonic acid from fungal single-cell oil (ARASCO)

    Microsoft Academic Search

    Shaik Ramjan Vali; Huei Ya Sheng; Yi-Hsu Ju

    2003-01-01

    PUFA, such as arachidonic acid (AA), have several pharmaceutical applications. An efficient method was developed to obtain\\u000a high-purity arachidonic acid (AA) from ARASCO, a single-cell oil from Martek (Columbia, MD). The method comprises three steps.\\u000a In the first step, AA was enriched from saponified ARASCO oil by low-temperature solvent crystallization using a polar, aprotic\\u000a solvent, which gave a FA fraction

  18. Influence of fatty acid ethanolamides and ? 9-tetrahydrocannabinol on cytokine and arachidonate release by mononuclear cells

    Microsoft Academic Search

    Evguenii V Berdyshev; Elisabeth Boichot; Noëlla Germain; Nathalie Allain; Jean-Pierre Anger; Vincent Lagente

    1997-01-01

    The effects of arachidonic acid ethanolamide (anandamide), palmitoylethanolamide and ?9-tetrahydrocannabinol on the production of tumor necrosis factor-? (TNF-?), interleukin-4, interleukin-6, interleukin-8, interleukin-10, interferon-?, p55 and p75 TNF-? soluble receptors by stimulated human peripheral blood mononuclear cells as well as [3H]arachidonic acid release by non-stimulated and N-formyl-Met–Leu–Phe (fMLP)-stimulated human monocytes were investigated. Anandamide was shown to diminish interleukin-6 and interleukin-8 production

  19. Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis

    Microsoft Academic Search

    Bruno Baggio; Alessandro Budakovic; Maria Angela Nassuato; Giuseppe Vezzoli; Enzo Manzato; Giovanni Luisetto; Martina Zaninotto

    2000-01-01

    Plasma phospholipid arachidonic acid content and calcium metabolism in idiopathic calcium nephrolithiasis.BackgroundReports of an increase in plasma and erythrocyte phospholipid arachidonic acid content and in urinary prostaglandin E2 (PGE2) excretion in patients with idiopathic calcium nephrolithiasis suggested their crucial role in the pathogenesis of hypercalciuria, a well-known risk factor for lithogenesis.MethodsTo confirm this hypothesis, 15 healthy subjects and 20 nephrolithiasis

  20. Depression of macrophage respiratory burst capacity and arachidonic acid release after Fc receptor-mediated phagocytosis.

    PubMed

    Schwacha, M G; Gudewicz, P W; Snyder, J A; Loegering, D J

    1993-01-01

    The phagocytosis of IgG-coated erythrocytes (ElgG) by macrophages results in a subsequent depression of macrophage phagocytic function, respiratory burst capacity, and bactericidal activity. Our study was carried out to determine the importance of impaired arachidonic acid release in the depression of the respiratory burst after ElgG phagocytosis. The depression of triggered H2O2 production after ElgG phagocytosis was not due to cyclooxygenase products because indomethacin or aspirin did not modify the depression. Further studies revealed that the depression of triggered H2O2 production after ElgG phagocytosis was associated with a depression in the ability of macrophages to release arachidonic acid in response to PMA, zymosan, or calcium ionophore. The addition of exogenous arachidonic acid partially prevented the depression of triggered H2O2 production after ElgG phagocytosis. Unlike phagocytosis mediated by FcR, complement receptor-mediated phagocytosis did not alter H2O2 production or arachidonic acid release. Ligation of FcR was not sufficient to depress triggered H2O2 production and arachidonic acid release because these functions were not depressed when phagocytosis was inhibited with cytochalasin D. Thus, it was found that the depression of triggered H2O2 production by macrophages after FcR-mediated phagocytosis was associated with impaired release of arachidonic acid and that H2O2 production could be partially restored by the addition of arachidonic acid. These results suggest that the impairment of arachidonic acid release after FcR-mediated phagocytosis contributes to the depression of macrophage respiratory burst capacity after FcR-mediated phagocytosis. PMID:8417125

  1. Cytochrome P450/NADPH-dependent formation of trans epoxides from trans-arachidonic acids.

    PubMed

    Roy, Uzzal; Loreau, Olivier; Balazy, Michael

    2004-02-23

    Trans-arachidonic acids (trans-AA) are products of cis-trans isomerization of arachidonic acid by nitrogen dioxide radical (NO(2)), and occur in vivo, but their metabolism is unknown. We found that hepatic microsomes oxidized trans-AA via cytochrome P450/NADPH system to epoxides, which were hydrolyzed by epoxide hydrolase to diols (DiHETEs). 14,15-trans-AA produced one erythro diol and three threo diols each having one trans double bond. PMID:15013014

  2. Ear canal dynamic motion as a source of power for in-ear devices

    NASA Astrophysics Data System (ADS)

    Delnavaz, Aidin; Voix, Jérémie

    2013-02-01

    Ear canal deformation caused by temporomandibular joint (jaw joint) activity, also known as "ear canal dynamic motion," is introduced in this paper as a candidate source of power to possibly recharge hearing aid batteries. The geometrical deformation of the ear canal is quantified in 3D by laser scanning of different custom ear moulds. An experimental setup is proposed to measure the amount of power potentially available from this source. The results show that 9 mW of power is available from a 15 mm3 dynamic change in the ear canal volume. Finally, the dynamic motion and power capability of the ear canal are investigated in a group of 12 subjects.

  3. Human ear recognition in 3D.

    PubMed

    Chen, Hui; Bhanu, Bir

    2007-04-01

    Human ear is a new class of relatively stable biometrics that has drawn researchers' attention recently. In this paper, we propose a complete human recognition system using 3D ear biometrics. The system consists of 3D ear detection, 3D ear identification, and 3D ear verification. For ear detection, we propose a new approach which uses a single reference 3D ear shape model and locates the ear helix and the antihelix parts in registered 2D color and 3D range images. For ear identification and verification using range images, two new representations are proposed. These include the ear helix/antihelix representation obtained from the detection algorithm and the local surface patch (LSP) representation computed at feature points. A local surface descriptor is characterized by a centroid, a local surface type, and a 2D histogram. The 2D histogram shows the frequency of occurrence of shape index values versus the angles between the normal of reference feature point and that of its neighbors. Both shape representations are used to estimate the initial rigid transformation between a gallery-probe pair. This transformation is applied to selected locations of ears in the gallery set and a modified Iterative Closest Point (ICP) algorithm is used to iteratively refine the transformation to bring the gallery ear and probe ear into the best alignment in the sense of the least root mean square error. The experimental results on the UCR data set of 155 subjects with 902 images under pose variations and the University of Notre Dame data set of 302 subjects with time-lapse gallery-probe pairs are presented to compare and demonstrate the effectiveness of the proposed algorithms and the system. PMID:17299227

  4. In vitro release of arachidonic acid and in vivo responses to respirable fractions of cotton dust

    SciTech Connect

    Thomson, T.A.; Edwards, J.H.; Al-Zubaidy, T.S.; Brown, R.C.; Poole, A.; Nicholls, P.J.

    1986-04-01

    It was considered that the fall in lung function seen after exposure to cotton dust may be attributable in part to the activity of arachidonic acid metabolites, such as leucotrienes as well as to the more established release of histamine by cotton dust. However, we found that cotton and barley dusts elicited poor release of arachidonic acid from an established macrophage like cell line compared with that observed with other organic dusts. In the experimental animal, pulmonary cellular responses to both cotton and barley dust were similar to those evoked by moldy hay and pigeon dropping dusts, although after multiple doses a more severe response was seen to cotton and barley. Since both moldy hay and pigeon droppings elicit a greater arachidonic acid release than cotton or barley, a role for arachidonic acid in inducing the cellular response is less likely than other factors. There are limitations to our conclusions using this system, i.e., the arachidonic acid may be released in a nonmetabolized form, although it is noted that the two dusts with the greatest arachidonic acid release produce their clinical responses in humans largely by hypersensitivity mechanisms.

  5. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants.

    PubMed

    Alvarez-Guerra, Miriam; Hannaert, Patrick; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

    2003-04-11

    Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity. Baseline permeability was linear up to 2 h, with a rate constant (k) of 0.0031+/-0.0007 h(-1). Intravenous arachidonate (from 30 microg/kg to 3 mg/kg) induced an immediate, dose-related and significant increase in permeability (ranging from 80% to 150%), which was comparable to the effect induced by similar doses of serotonin. Aspirin (10 mg/kg) reduced the arachidonate-induced permeability by 75%, but interestingly neither the stable thromboxane A(2) receptor agonist U46619 (prostaglandin H(2) endoperoxide epoxymethane) nor prostacyclin was able to increase peritoneal vascular permeability. In contrast, the permeabilizing action of arachidonic acid was very sensitive to antioxidant agents. Thus, vitamin C and the flavonoid compound troxerutin (100 mg/kg) fully abolished arachidonate-induced permeability, whereas vitamin E had only a partial effect (40-100% inhibition). In conclusion, intravenous administration of arachidonic acid strongly enhanced peritoneal vascular permeability in the rat, apparently via free radical generation. This rat peritoneal model can be used to evaluate the in vivo antinflammatory potential of antioxidant drugs. PMID:12679157

  6. Cloning and sequencing of a bile acid-inducible operon from Eubacterium sp. strain VPI 12708.

    PubMed Central

    Mallonee, D H; White, W B; Hylemon, P B

    1990-01-01

    Two bile acid-inducible polypeptides from Eubacterium sp. strain VPI 12708 with molecular weights of 27,000 and approximately 45,000 have previously been shown to be encoded by genes residing on a 2.9-kb EcoRI fragment. We now report the cloning and sequencing of three additional overlapping DNA fragments upstream from this EcoRI fragment. Together, these four fragments contain a large segment of a bile acid-inducible operon which encodes the 27,000- and 45,000-Mr (now shown to be 47,500-Mr) polypeptides and open reading frames potentially coding for four additional polypeptides with molecular weights of 59,500, 58,000, 19,500, and 9,000 to 11,500. A bile acid-inducible polypeptide with an apparent Mr of 23,500, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was purified to homogeneity, and the N-terminal amino acid sequence that was obtained matched the sequence deduced from the open reading frame coding for the 19,500-Mr polypeptide. A short DNA segment containing the 3' downstream end of the gene coding for the 47,500-Mr polypeptide was not successfully cloned but was directly sequenced from DNA fragments synthesized by polymerase chain reaction. The mRNA initiation site for the bile acid-inducible operon was shown by primer extension to be immediately upstream from the gene encoding the 58,000-Mr polypeptide. A potential promoter region upstream from the mRNA initiation site displayed significant homology with the promoter regions of previously identified bile acid-inducible genes from Eubacterium sp. strain VPI 12708. We hypothesize that this bile acid-inducible operon codes for most of the enzymes involved in the bile acid 7 alpha-dehydroxylation pathway in this bacterium. Images PMID:2254270

  7. Numerical simulation of the human ear and the dynamic analysis of the middle ear sound transmission

    NASA Astrophysics Data System (ADS)

    Yao, W.; Ma, J.; Huang, X.

    2013-06-01

    Based on the clinical CT of normal right ear, a 3-D ?nite element (FE) model of the human ear consisting of the external ear canal, middle ear(tympanic membrane, ossicular chain, ligaments, tendons), and inner ear (including semicircular canals, vestibular, spiral cochlear)was constructed in this paper. The complicated structures and inner boundary conditions of middle ear were described in this model. Model analysis and acoustic-structure-?uid coupled dynamic frequency response analysis were conducted on the model. The validity of this model was confirmed by comparing the results with published experimental data. The amplitudes and velocities of tympanic membrane and stapes footplate, sound pressure gain across the middle ear, and the cochlear input impedance were derived. Besides, it was concluded that the ear canal can amplify the sound signal in low frequencies.The modes of vibration of middle ear auditory ossicles, oval window and round window have been analysed. This model can well simulate the acoustic behavior with the interaction of external ear, middle ear and inner ear, which can supply more valuable theoretical support for development and improvement of hearing-aid and artificial inner ear.

  8. Arachidonate 12-lipoxygenases with reference to their selective inhibitors

    SciTech Connect

    Yamamoto, Shozo [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan)]. E-mail: yamamosh@kyoto-wu.ac.jp; Katsukawa, Michiko [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Nakano, Ayumi [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Hiraki, Emi [Department of Food and Nutrition, Faculty of Home Economics, Kyoto Women's University, Imakumano, Higashiyama-ku, Kyoto 605-8501 (Japan); Nishimura, Kohji [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Jisaka, Mitsuo [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Yokota, Kazushige [Faculty of Life and Environmental Science, Shimane University, Matsue, Shimane 690-8504 (Japan); Ueda, Natsuo [Department of Biochemistry, School of Medicine, Kagawa University, Miki-cho, Kita-gun, Kagawa 761-0793 (Japan)

    2005-12-09

    Lipoxygenase is a dioxygenase recognizing a 1-cis,4-cis-pentadiene of polyunsaturated fatty acids. The enzyme oxygenates various carbon atoms of arachidonic acid as a substrate and produces 5-, 8-, 12- or 15-hydroperoxy eicosatetraenoic acid with a conjugated diene chromophore. The enzyme is referred to as 5-, 8-, 12- or 15-lipoxygenase, respectively. Earlier we found two isoforms of 12-lipoxygenase, leukocyte- and platelet-type enzymes, which were distinguished by substrate specificity, catalytic activity, primary structure, gene intron size, and antigenicity. Recently, the epidermis-type enzyme was found as the third isoform. Attempts have been made to find isozyme-specific inhibitors of 12-lipoxygenase, and earlier we found hinokitol, a tropolone, as a potent inhibitor selective for the platelet-type 12-lipoxygenase. More recently, we tested various catechins of tea leaves and found that (-)-geotechnical gallate was a potent and selective inhibitor of human platelet 12-lipoxygenase with an IC{sub 5} of 0.14 {mu}M. The compound was much less active with 12-lipoxygenase of leukocyte-type, 15-, 8-, and 5-lipoxygenases, and cyclo oxygenases-1 and -2.

  9. Cytochrome P450 arachidonic acid metabolism in bovine corneal epithelium

    SciTech Connect

    Masferrer, J.; Schwartzman, M.L.; Abraham, N.G.; Dunn, M.W.; McGiff, J.C.

    1986-03-01

    The presence of the cytochrom P450 system and its involvement in the metabolism of AA was studied in the corneal epithelium. This tissue contains cytochrome P450 as assessed directly by measurement of the carbon monoxide reduced spectrum (specific activity of 161 pmol/10 mg protein) and indirectly by measuring the activity of aryl hydrocarbon hydroxylase (AHH) - a cytochrome P450-dependent enzyme (11-39 pmol 3-OH benzopyrene/mg protein/10 min). When corneal epithelial microsomes were incubated with /sup 14/C-arachidonic acid, 30-50% of the total radioactivity was converted to two peaks, I and II. Further separation using high performance liquid chromatography has shown that each peak contains two metabolites, A,B and C,D. Metabolite formation was dependent on the addition of NADPH (1 mM) and inhibited by carbon monoxide and SKF-525A (100 ..mu..M) suggesting a cytochrome P450-dependent mechanism. Compound C (5-10 ..mu..M) inhibited the activity of corneal epithelial Na-K-ATPase by 30-60%, being 100-fold more potent than ouabain. Compound D (10-100 ng) induced a dose dependent relaxation of the rat caudal artery. Compound D also inhibited corneal Na-K-ATPase activity but less potently than compound C. These compounds may be important to transport processes of ocular epithelia and participate in the control of the ocular circulation and aqueous humor dynamics.

  10. Dietary arachidonic acid in perinatal nutrition: a commentary.

    PubMed

    Lauritzen, Lotte; Fewtrell, Mary; Agostoni, Carlo

    2015-01-01

    Arachidonic acid (AA) is supplied together with docosahexaenoic acid (DHA) in infant formulas, but we have limited knowledge about the effects of supplementation with either of these long-chain polyunsaturated fatty acids (LCPUFA) on growth and developmental outcomes. AA is present in similar levels in breast milk throughout the world, whereas the level of DHA is highly diet dependent. Autopsy studies show similar diet-dependent variation in brain DHA, whereas AA is little affected by intake. Early intake of DHA has been shown to affect visual development, but the effect of LCPUFA on neurodevelopment remains to be established. Few studies have found any functional difference between infants supplemented with DHA alone compared to DHA+AA, but some studies show neurodevelopmental advantages in breast-fed infants of mothers supplemented with n-3 LCPUFA alone. It also remains to be established whether the AA/DHA balance could affect allergic and inflammatory outcomes later in life. Disentangling effects of genetic variability and dietary intake on AA and DHA-status and on functional outcomes may be an important step in the process of determining whether AA-intake is of any physiological or clinical importance. However, based on the current evidence we hypothesize that dietary AA plays a minor role on growth and development relative to the impact of dietary DHA. PMID:25314584

  11. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.

    PubMed

    Yuan, Dongjuan; Zou, Qiuqiong; Yu, Ting; Song, Cuikai; Huang, Shengfeng; Chen, Shangwu; Ren, Zhenghua; Xu, Anlong

    2014-09-01

    Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus. PMID:24801744

  12. An Effective 3D Ear Acquisition System

    PubMed Central

    Liu, Yahui; Lu, Guangming; Zhang, David

    2015-01-01

    The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition. PMID:26061553

  13. An Effective 3D Ear Acquisition System.

    PubMed

    Liu, Yahui; Lu, Guangming; Zhang, David

    2015-01-01

    The human ear is a new feature in biometrics that has several merits over the more common face, fingerprint and iris biometrics. It can be easily captured from a distance without a fully cooperative subject. Also, the ear has a relatively stable structure that does not change much with the age and facial expressions. In this paper, we present a novel method of 3D ear acquisition system by using triangulation imaging principle, and the experiment results show that this design is efficient and can be used for ear recognition. PMID:26061553

  14. Adenomatous tumors of the middle ear.

    PubMed

    Pelosi, Stanley; Koss, Shira

    2015-04-01

    Adenomatous tumors are an uncommon cause of a middle ear mass. Clinical findings may be nonspecific, leading to difficulties in differentiation from other middle ear tumors. Controversy also exists whether to classify middle ear adenoma and carcinoid as separate neoplasms, or alternatively within a spectrum of the same pathologic entity. Most adenomatous middle ear tumors are indolent in behavior, with a benign histologic appearance and slowly progressive growth. The mainstay of treatment is complete surgical resection, which affords the greatest likelihood of cure. PMID:25769353

  15. Welfare implications of sheep ear tags.

    PubMed

    Edwards, D S; Johnston, A M

    1999-05-29

    The damaging effects of ear tags used to identify sheep were studied by examining the ears of sheep after slaughter in three different abattoirs and the ears of sheep on a farm. In total, 1040 ears with tags were examined. There were six types of ear tag: metal 'Ketchum' style loop tags; two-piece rigid plastic tags; 'Allflex' style flexible plastic tags with a male and female part; golf tee-shaped plastic ear tags; one-piece rigid plastic loop tags; and one-piece flexible plastic tags with a flap. The metal loop tags and plastic loop tags caused the most lesions, and the majority of the severe lesions. Ear tags placed near to the tip of the ear appeared to cause more damage. Some of the Ketchum style metal tags and two-piece rigid plastic tags appeared to be relatively new, as if recently fitted. These tags were more often associated with ear lesions, particularly moderate or severe lesions. The Allflex style flexible plastic tags caused the fewest problems, and the golf tee-shaped plastic tags also caused significantly fewer problems than the other tags. PMID:10390799

  16. Fear the EAR: Discovering and Mitigating Execution After Redirect Vulnerabilities

    E-print Network

    California at Santa Barbara, University of

    Fear the EAR: Discovering and Mitigating Execution After Redirect Vulnerabilities Adam Doupé, Bryce Execution After Redirect, or EAR. A web application de- veloper can introduce an EAR by calling a redirect web frameworks are to EAR vulnerabilities. We then discuss the results from the EAR challenge

  17. Arachidonic acid-enriched triacylglycerol improves cognitive function in elderly with low serum levels of arachidonic acid.

    PubMed

    Tokuda, Hisanori; Kontani, Masanori; Kawashima, Hiroshi; Akimoto, Kengo; Kusumoto, Aki; Kiso, Yoshinobu; Koga, Yoshihiko; Shibata, Hiroshi

    2014-01-01

    Arachidonic acid (ARA) is an n-6 PUFA and is thought to have an important role in various physiological and psychological functions. Recently, supplementation with ARA-enriched TAG was shown to improve age-related decreases in cognitive function in healthy elderly men. To investigate the influence of baseline serum ARA status on cognitive function and its improvement, we analyzed cognitive function stratified by serum ARA level. The stratified analysis was also conducted for the effects of ARA-enriched TAG supplementation on cognitive improvement. Cognitive function was evaluated by measuring event-related potentials (ERPs), including P300 latency and amplitude. When participants were stratified by baseline serum ARA level, P300 latency was significantly longer and P300 amplitude was generally lower in the low-ARA group than in the high-ARA group. No significant difference in P300 components was observed when participants were stratified by serum levels of any other fatty acid. ARA-enriched TAG supplementation significantly shortened P300 latency and increased P300 amplitude in the low-ARA group, although no significant differences were observed in the high-ARA group. These findings suggest that lower serum ARA levels were associated with cognitive function in elderly men and that ARA-enriched TAG supplementation is more effective in improving cognitive function in healthy elderly men with low serum ARA levels than in those with high serum ARA levels. PMID:24521845

  18. Transfer of arachidonate from phosphatidylcholine to phosphatidylethanolamine and triacylglycerol in guinea pig alveolar macrophages

    SciTech Connect

    Nijssen, J.G.; Oosting, R.S.; Nkamp, F.Pv.; van den Bosch, H.

    1986-10-01

    Guinea pig alveolar macrophages were labeled by incubation with either arachidonate or linoleate. Arachidonate labeled phosphatidylcholine (PC), phosphatidylethanolamine (PE) and triglycerides (TG) equally well, with each lipid containing about 30% of total cellular radioactivity. In comparison to arachidonate, linoleate was recovered significantly less in PE (7%) and more in TG (47%). To investigate whether redistributions of acyl chains among lipid classes took place, the macrophages were incubated with 1-acyl-2-(1-/sup 14/C)arachidonoyl PC or 1-acyl-2-(1-/sup 14/C)linoleoyl PC. After harvesting, the cells incubated with 1-acyl-2-(1-/sup 14/C)linoleoyl PC contained 86% of the recovered cellular radioactivity in PC, with only small amounts of label being transferred to PE and TG (3 and 6%, respectively). More extensive redistributions were observed with arachidonate-labeled PC. In this case, only 60% of cellular radioactivity was still associated with PC, while 22 and 12%, respectively, had been transferred to PE and TG. Arachidonate transfer from PC to PE was unaffected by an excess of free arachidonate which inhibited this transfer to TG for over 90%, indicating that different mechanisms or arachidonoyl CoA pools were involved in the transfer of arachidonate from PC to PE and TG. Cells prelabeled with 1-acyl-2-(1-/sup 14/C)arachidonoyl PC released /sup 14/C-label into the medium upon further incubation. This release was slightly stimulated by zymosan and threefold higher in the presence of the Ca2+-ionophore A23187. Labeling of macrophages with intact phospholipid molecules appears to be a suitable method for studying acyl chain redistribution and release reactions.

  19. Inhibition of Acid-induced Lung Injury by Hyperosmolar Sucrose in Rats

    Microsoft Academic Search

    Zeenat Safdar; Maimiti Yiming; Gabriele Grunig; Jahar Bhattacharya

    2005-01-01

    Rationale: Acid aspiration causes acute lung injury (ALI). Recently, we showed that a brief intravascular infusion of hyperosmolar su- crose, given concurrently with airway acid instillation, effectively blocks the ensuing ALI. Objectives: The objective of the present study was to determine the extent to which intravascular infusion of hyperosmolar sucrose might protect against acid-induced ALI when given either before or

  20. Role of substance P and tachykinin receptor antagonists in citric acid-induced cough in pigs.

    PubMed

    Moreaux, B; Nemmar, A; Vincke, G; Halloy, D; Beerens, D; Advenier, C; Gustin, P

    2000-11-24

    The purpose of this work was to investigate the role of tachykinins in cough induced by citric acid (0.8 M) in pigs. With this object, we have studied the effect of citric acid on substance P content in the tracheo-bronchial tree and the effects of substance P and of tachykinin receptor antagonists on citric acid-induced cough. Citric acid exposure significantly increased substance P concentration in both broncho-alveolar and tracheal lavage fluids, while it decreased significantly the substance P content in tracheal mucosa. Substance P did not elicit cough, but significantly potentiated the citric acid-induced cough frequency. Tachykinin NK(1), NK(2) or NK(3) receptor antagonists, SR 140333 (nolpitantium), SR 48968 (saredutant) and SR 142801 (osanetant), respectively, significantly inhibited citric acid-induced cough. The same inhibitory effect of tachykinin receptor antagonists was observed, when substance P was nebulised before citric acid challenge. We conclude that citric acid induces in pigs a release of substance P in the tracheo-bronchial tree, which plays a sensitising role on the cough reflex. The involvement of tachykinin NK(1), NK(2), NK(3) receptors are also demonstrated in this reflex. PMID:11090648

  1. Glutathione Levels Modulate Domoic Acid Induced Apoptosis in Mouse Cerebellar Granule Cells

    Microsoft Academic Search

    Gennaro Giordano; Collin C. White; Isaac Mohar; Terrance J. Kavanagh; Lucio G. Costa

    2007-01-01

    Exposure of mouse cerebellar granule neurons (CGNs) to domoic acid induced cell death, either by apoptosis or by necrosis, depending on its concentration. Necrotic damage predominated in response to domoic acid above 0.1mM. In contrast, cell injury with apoptotic features (assessed by Hoechst staining and DNA laddering assay) was evident after exposure to lower concen- trations of domoic acid (£

  2. Impaired Cell Function in Human Aging: Response to Nicotinic Acid-Induced Insulin Resistance

    Microsoft Academic Search

    Annette M. Chang; Marla J. Smith; Andrzej T. Galecki; Cathie J. Bloem; Jeffrey B. Halter

    Context: Glucose tolerance declines with age and may involve im- paired -cell sensitivity to glucose and -cell compensation for insulin resistance. Objective: We investigated -cell sensitivity to glucose and -cell compensation for nicotinic acid-induced insulin resistance in young (age 35 yr) people with normal glucose tolerance (NGT) and old (age 60 yr) people with NGT and impaired glucose tolerance (IGT).

  3. Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

    SciTech Connect

    Schick, P.K.; Webster, P.

    1987-05-01

    Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with (/sup 14/C)-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of (/sup 14/C)-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of (/sup 14/C)-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of (/sup 14/C)-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA.

  4. Niacin Sensitivity and the Arachidonic Acid Pathway in Schizophrenia

    PubMed Central

    Messamore, Erik; Hoffman, William F.; Yao, Jeffrey K.

    2010-01-01

    Objective Schizophrenia is associated with a blunted flush response to niacin. Since niacin-induced skin flushing is mediated by vasodilators derived from arachidonic acid (AA), we tested whether the blunted flush response to niacin is a marker of AA deficiency. Methods Eight concentrations of methylnicotinate were applied to the forearms of 20 adults with schizophrenia and 20 controls. Laser Doppler measurement of blood flow responses was used to derive values for niacin sensitivity (defined as the concentration eliciting half-maximal response, i.e., EC50 value) and efficacy (defined as the maximal evoked blood flow response). RBC membrane fatty acids were analyzed by gas chromatography. Results Niacin sensitivity and efficacy were reduced in schizophrenia. In the control group, there was significant correlation between AA levels and niacin sensitivity as well as a trend toward correlation between AA levels and niacin efficacy. In contrast, neither sensitivity nor efficacy of niacin correlated with AA levels in schizophrenia. An expected correlation between the levels of AA and its elongation product (adrenic acid) was absent in schizophrenia. Adrenic acid levels correlated with niacin efficacy in schizophrenia. Conclusions The schizophrenia-associated niacin response abnormality involves both diminished sensitivity and reduced efficacy. The lack of expected correlation between levels of AA and adrenic acid suggests homeostatic imbalance within the n-6 polyunsaturated fatty acid (PUFA) pathway in schizophrenia. Though AA levels were unrelated to measures of niacin response in schizophrenia, the correlation between adrenic acid and niacin efficacy in schizophrenia suggests relevance of the n-6 PUFA pathway to the blunted niacin response. PMID:20417059

  5. Value of Ear Endoscopy in Cholesteatoma Surgery

    Microsoft Academic Search

    M. Badr-el-Dine

    2002-01-01

    Objective: The purpose of this study was to assess the value of ear endoscopy in cholesteatoma surgery and to demonstrate its consequence in improving surgical outcome. Materials and Methods: A total of 92 ears with acquired cholesteatoma (primary or secondary) were operated on. In this prospective study, 82 cases were operated on by using canal wall up (CWU) technique, and

  6. Primary carcinoid tumor of the ear

    Microsoft Academic Search

    S. Inoue; K. Tanaka; S. Kannae

    1982-01-01

    A very rare case of primary carcinoid tumor in the left ear of a 35-year-old woman is described. The argyrophilic property and uniformity of the size and shape of neurosecretory granules in the cytoplasm of tumor cells, correspond to the characteristics of carcinoid tumors derived from foregut endoderm. Clinical and light microscopic observations suggest this tumor originated from middle ear

  7. Review Article Mechanics of the frog ear

    E-print Network

    Allen, Jont

    Review Article Mechanics of the frog ear Pim Van Dijk a,b,*, Matthew J. Mason c , Richard L s t r a c t The frog inner ear contains three regions that are sensitive to airborne sound and which of the frog's auditory range. It shares the ability to generate both evoked and spontaneous otoacoustic

  8. "Hot Tub Rash" and "Swimmer's Ear" (Pseudomonas)

    MedlinePLUS

    Facts About “Hot Tub Rash” and “Swimmer’s Ear” (Pseudomonas) What is Pseudomonas and how can it affect me? Pseudomonas (sue-doh- ... a major cause of infections commonly known as “hot tub rash” and “swimmer’s ear.” This germ is ...

  9. Orf infection following ear tagging in goats.

    PubMed

    Housawi, F M; Abu Elzein, E M

    1991-01-01

    This communication describes the first record of orf infection in goats following ear-tagging. Typical orf lesions were observed in the affected goats, and the virus was reisolated and identified from them. The threat of orf infection following ear-tagging should be kept in mind in orf-endemic regions. PMID:1824135

  10. Pediatric Obesity and Ear, Nose, and Throat Disorders

    MedlinePLUS

    Pediatric Obesity and Ear, Nose, and Throat Disorders Pediatric Obesity and Ear, Nose, and Throat Disorders Patient Health Information ... self-esteem, and isolation from their peers. Pediatric obesity and otolaryngic problems Otolaryngologists, or ear, nose, and ...

  11. Metabolism of arachidonic and adrenic acids in molecular species of gycerophospholipids in mouse brain

    SciTech Connect

    Harder, H.W.

    1986-01-01

    Arachidonic acid, the precursor of prostaglandins and other eicosanoids, is very important for normal function and pathophysiology in nearly all tissues. The content of arachidonic acid is particularly large in the brain which also contains relatively large amounts of adrenic acid, the elongation product of arachidonic acid. These fatty acids are found in the glycerophospholipids. Unesterified (/sup 3/H)arachidoninc acid (20:4) and (/sup 14/C)adrenic acid (22:4) complexed to bovine serum albumin, were simultaneously injected into the left lateral ventricles of C3H mice. A 400-fold larger mass of 22:4 relative to 20:4 was used. At selected times following injection, brains were frozen and lipids were extracted for analysis of incorporation of radioactivity into diacylglycerols, tricyglycerols, total phospholipids, and the molecular species ethanolamine, choline and inositol glycerophospholipids. The greatest uptake of arachidonic acid was found in some molecular species of the choline plasmalogens. This suggests an important function for such molecules. The suggested function is in signal transduction across cell membranes following activation of receptors. This process may stimulate the hydrolysis of choline plasmalogens with the release of arachidonic acid which can then be metabolized to prostaglandins, leukotrienes, or other biologically potent compounds.

  12. [Cochlear damage caused by middle ear surgeries].

    PubMed

    Hüttenbrink, K B

    1991-02-01

    A prospective study was set up to study the reaction of the cochlea after the trauma of middle-ear surgery. For this purpose, the bone conduction of 50 patients was tested every day, beginning on the first post-operative day. To collect information on possible damaging mechanisms, three surgical techniques were studied: Stapes surgery with the opening of the inner ear; mastoidectomy with drill-generated noise; tympanoplasty with manipulations at the stapes. The comparison of the bone conduction thresholds with audiometry results after completed healing of the ear, disclosed that even under the ear-packing, bone conduction can give reliable information on cochlea function, if a 10-15 dB variance due to methodological causes is taken into account. Excessive drilling may result in a temporary threshold shift, which has already resolved at the time of unpacking the ear. No signs of hydraulic damage after manipulation at the stapes could be discovered. PMID:2029305

  13. Gene therapy for the inner ear

    PubMed Central

    Fukui, Hideto; Raphael, Yehoash

    2012-01-01

    Animal studies on inner ear development, repair and regeneration provide understanding of molecular pathways that can be harnessed for treating inner ear disease. Use of transgenic mouse technology, in particular, has contributed knowledge of genes that regulate development of hair cells and innervation, and of molecular players that can induce regeneration, but this technology is not applicable for human treatment, for practical and ethical reasons. Therefore other means for influencing gene expression in the inner ear are needed. We describe several gene vectors useful for inner ear gene therapy and the practical aspects of introducing these vectors into the ear. We then review the progress toward using gene transfer for therapies in both auditory and balance systems, and discuss the technological milestones needed to advance to clinical application of these methods. PMID:23265411

  14. The alpha 1-adrenergic transduction system in hamster brown adipocytes. Release of arachidonic acid accompanies activation of phospholipase C.

    PubMed Central

    Schimmel, R J

    1988-01-01

    Previous studies of brown adipocytes identified an increased breakdown of phosphoinositides after selective alpha 1-adrenergic-receptor activation. The present paper reports that this response, elicited with phenylephrine in the presence of propranolol and measured as the accumulation of [3H]inositol phosphates, is accompanied by increased release of [3H]arachidonic acid from cells prelabelled with [3H]arachidonic acid. Differences between stimulated arachidonic acid release and formation of inositol phosphates included a requirement for extracellular Ca2+ for stimulated release of arachidonic acid but not for the formation of inositol phosphates and the preferential inhibition of inositol phosphate formation by phorbol 12-myristate 13-acetate. The release of arachidonic acid in response to phenylephrine was associated with an accumulation of [3H]arachidonic acid-labelled diacylglycerol, and this response was not dependent on extracellular Ca2+ but was partially prevented by treatment with the phorbol ester. The release of arachidonic acid was also stimulated by melittin, which increases the activity of phospholipase A2, by ionophore A23187, by lipolytic stimulation with forskolin and by exogenous phospholipase C. The arachidonic acid response to phospholipase C was completely blocked by RHC 80267, an inhibitor of diacylglycerol lipase, but this inhibitor had no effect on release stimulated with melittin or A23187 and inhibited phenylephrine-stimulated release by only 40%. The arachidonate response to forskolin was additive with the responses to either phenylephrine or exogenous phospholipase C. These data indicate that brown adipocytes are capable of releasing arachidonic acid from neutral lipids via triacylglycerol lipolysis, and from phospholipids via phospholipase A2 or by the sequential activities of phospholipase C and diacylglycerol lipase. Our findings also suggest that the action of phenylephrine to promote the liberation of arachidonic acid utilizes both of these reactions. PMID:3138988

  15. Effect of progesterone on the release of arachidonic acid from human endometrial cells stimulated by histamine

    SciTech Connect

    Wilson, T.; Liggins, G.C.; Aimer, G.P.; Watkins, E.J.

    1986-02-01

    Progesterone at concentrations of 10(-7)M and 10(-8)M inhibits release of (/sup 3/H)-arachidonic acid from stimulated, perfused, endometrial cells. The effect is independent of the mechanism of stimulation. Cortisol (10(-5)M but not 10(-7)M) has a similar effect in this system but estradiol (10(-7)M) is without effect. There was a positive correlation (p less than 0.05) between the magnitude of inhibition by progesterone and the day of cycle. The inhibitory action of progesterone on the release of arachidonic acid was greater in endometrial cells than in decidual cells and was apparent after fifteen minutes. The activities of commercial and endometrial cell-free preparations of phospholipase A2 and phospholipase C were unaffected by the presence of progesterone. We conclude that progesterone modulates release of (/sup 3/H)-arachidonic acid from endometrial cells by a rapid, indirect action on phospholipase activity.

  16. Arachidonic acid turnover in response to lipopolysaccharide and opsonized zymosan in human monocyte-derived macrophages.

    PubMed Central

    Leslie, C C; Detty, D M

    1986-01-01

    Macrophages are an important source of the lipid mediators, arachidonic acid metabolites and platelet-activating factor (PAF), produced during inflammation. Studies were undertaken to identify the phospholipid substrates that can serve as a source of arachidonic acid in human monocyte-derived macrophages exposed to the inflammatory stimuli bacterial lipopolysaccharide (LPS) and opsonized zymosan (OpZ). Since PAF is derived from 1-alkyl-2-acyl-glycerophosphocholine, it was of interest to determine if this phospholipid precursor could also serve as a source of arachidonic acid. The day-5 macrophages incorporated 38% of the available [3H]arachidonic acid into lipid by 4 h, 54% of which was in phospholipid [phosphatidylcholine (PC) greater than phosphatidylethanolamine (PE) greater than phosphatidylinositol (PI)]. The proportion of label incorporated into ether-linked PC and PE increased with time. After prelabelling with [3H]arachidonic acid, the effect of stimuli on the redistribution of label within phospholipids was followed. Without stimulus there was a loss of label from PC, PI and phosphatidic acid by 3 h, but an increase of label in PE. The [3H]arachidonic acid that was lost from PC in the absence of stimulus was derived solely from the 1-acyl-linked species of PC, whereas an increase in label occurred in the 1-alkyl-linked species of PC. By contrast, LPS stimulation resulted in a preferential, dose-dependent loss of label from PC and PI, which was maximal between 1 and 3 h after adding the LPS. In addition, LPS induced a 35% decrease in the molar quantity of PI in the macrophages but had no effect on the quantity of PC, PE or phosphatidylserine. Stimulation with OpZ also resulted in a loss of label, mainly from PC and PI. Of the total label lost from PC in response to LPS or OpZ, approx. 50% was derived from the 1-alkyl-linked species. The results suggest that phospholipase C- and phospholipase A2-mediated mechanisms for arachidonic acid release are activated in human macrophages exposed to the inflammatory stimuli LPS and OpZ. In addition, 1-alkyl-linked PC can serve as a source of arachidonic acid and as a precursor for PAF production in the stimulated macrophages. PMID:3098232

  17. Cinnamtannin D-1 protects pancreatic ?-cells from palmitic acid-induced apoptosis by attenuating oxidative stress.

    PubMed

    Wang, Ting; Sun, Peng; Chen, Liang; Huang, Qi; Chen, Kaixian; Jia, Qi; Li, Yiming; Wang, Heyao

    2014-06-01

    In previous studies, A-type procyanidin oligomers isolated from Cinnamomum tamala were proved to possess antidiabetic effect and protect pancreatic ?-cells in vivo. The aim of this study was to unveil the mechanisms of protecting pancreatic ?-cells from palmitic acid-induced apoptosis by cinnamtannin D-1 (CD1), one of the main A-type procyanidin oligomers in C. tamala. CD1 was discovered to dose-dependently reduce palmitic acid- or H2O2-induced apoptosis and oxidative stress in INS-1 cells, MIN6 cells, and primary cultured murine islets. Moreover, CD1 could reverse palmitic acid-induced dysfunction of glucose-stimulated insulin secretion in primary cultured islets. These results indicate that reduction of apoptosis and oxidative stress might account for the protection effect of CD1, which provided a better understanding of the mechanisms of the antidiabetic effects of procyanidin oligomers. PMID:24815044

  18. Heterologous expression of a tannic acid-inducible laccase3 of Cryphonectria parasitica in Saccharomyces cerevisiae

    Microsoft Academic Search

    Jung-Mi Kim; Seung-Moon Park; Dae-Hyuk Kim

    2010-01-01

    BACKGROUND: A tannic acid-inducible and mycoviral-regulated laccase3 (lac3) from the chestnut blight fungus Cryphonectria parasitica has recently been identified, but further characterization was hampered because of the precipitation of protein products by tannic acid supplementation. The present study investigated the heterologous expression of the functional laccase3 using a yeast Saccharomyces cerevisiae. RESULTS: Laccase activity in the culture broth of transformants

  19. Acid-induced gelation of natural actomyosin from Atlantic cod ( Gadus morhua) and burbot ( Lota lota)

    Microsoft Academic Search

    Siriporn Riebroy; Soottawat Benjakul; Wonnop Visessanguan; Ulf Erikson; Turid Rustad

    2009-01-01

    The acid-induced gelation of natural actomyosin (NAM) from burbot (Lota lota) and Atlantic cod (Gardus morhua) added with d-gluconic acid-?-lactone (GDL) during incubation at room temperature (22–23°C) for 48h was investigated. During acidification, pH values of both NAMs reached 4.6 within 48h. Both NAMs underwent aggregation during acidification as evidenced by increases in turbidity and particle size, especially after 6h

  20. Retinoic acid inducible gene-I, more than a virus sensor

    Microsoft Academic Search

    Feng Liu; Jun Gu

    2011-01-01

    Retinoic acid inducible gene-I (RIG-I) is a caspase recruitment domain (CARD) containing protein that acts as an intracellular\\u000a RNA receptor and senses virus infection. After binding to double stranded RNA (dsRNA) or 5?-triphosphate single stranded RNA\\u000a (ssRNA), RIG-I transforms into an open conformation, translocates onto mitochondria, and interacts with the downstream adaptor\\u000a mitochondrial antiviral signaling (MAVS) to induce the production

  1. Boron-free fibers for prevention of acid induced brittle fracture of composite insulator GRP rods

    Microsoft Academic Search

    Daniel L. Armentrout; Maciej Kumosa; Terry S. McQuarrie

    2003-01-01

    An investigation was performed to determine whether corrosion resistant boron-free E-glass fibers could adequately prevent acid induced brittle fracture failures of high voltage composite insulator rods. Nine different rod compositions were tested at 45% of mechanical failure load in contact with 1 N nitric acid. Rods made out of commonly used E-glass fibers failed mechanically in less than 2 h

  2. Fatty acid protection from palmitic acid-induced apoptosis is lost following PI3-kinase inhibition

    Microsoft Academic Search

    N. Beeharry; J. A. Chambers; I. C. Green

    2004-01-01

    We have previously shown that saturated fatty acids induce DNA damage and cause apoptotic cell death in insulin-producing ß-cells. Here we examine further the effects of single or combined dietary fatty acids on RINm5F survival or cell death signalling. Palmitate and stearate, but not linoleate, oleate or palmitoylmethyl ester, induced growth inhibition and increased apoptosis in RINm5F cells following 24

  3. Pinna abnormalities and low-set ears

    MedlinePLUS

    ... Common abnormalities include cysts in the pinna or skin tags . Many children are born with ears that stick ... affect hearing. However, sometimes cosmetic surgery is recommended. Skin tags may be tied off, unless there is cartilage ...

  4. An analysis of the acoustic input impedance of the ear.

    PubMed

    Withnell, Robert H; Gowdy, Lauren E

    2013-10-01

    Ear canal acoustics was examined using a one-dimensional lossy transmission line with a distributed load impedance to model the ear. The acoustic input impedance of the ear was derived from sound pressure measurements in the ear canal of healthy human ears. A nonlinear least squares fit of the model to data generated estimates for ear canal radius, ear canal length, and quantified the resistance that would produce transmission losses. Derivation of ear canal radius has application to quantifying the impedance mismatch at the eardrum between the ear canal and the middle ear. The length of the ear canal was found, in general, to be longer than the length derived from the one-quarter wavelength standing wave frequency, consistent with the middle ear being mass-controlled at the standing wave frequency. Viscothermal losses in the ear canal, in some cases, may exceed that attributable to a smooth rigid wall. Resistance in the middle ear was found to contribute significantly to the total resistance. In effect, this analysis "reverse engineers" physical parameters of the ear from sound pressure measurements in the ear canal. PMID:23917695

  5. Purdue extensionDiplodia Ear Rot Purdue extension

    E-print Network

    Holland, Jeffrey

    1 Purdue extensionDiplodia Ear Rot BP-75-W Purdue extension d i s e a s e s o f c o r n Diplodia Ear Rot Authors: Charles Woloshuk Kiersten Wise www.btny.purdue.edu Diplodia ear rot, caused Diplodia ear rot. Hybrid susceptibility and weather also contribute to disease development. This bulletin

  6. PURDUE EXTENSIONArrested Ear Development in Hybrid Corn PURDUE EXTENSION

    E-print Network

    Holland, Jeffrey

    1 PURDUE EXTENSIONArrested Ear Development in Hybrid Corn BP-85-W PURDUE EXTENSION D I S E A S E S O F C O R N Arrested Ear Development in Hybrid Corn www.btny.purdue.edu Arrested ear develop- ment to the abnormal corn ear development caused by a number of stress factors, including the application of nonionic

  7. Short Papers___________________________________________________________________________________________________ Comparison and Combination of Ear and Face

    E-print Network

    Bowyer, Kevin W.

    ___________________________________________________________________________________________________ Comparison and Combination of Ear and Face Images in Appearance-Based Biometrics Kyong Chang, Kevin W. Bowyer that the ear may have advantages over the face for biometric recognition. Our previous experiments with ear performance using ear images. We report results of similar experiments on larger data sets that are more

  8. A Pain in the Ear: The Radiology of Otalgia

    Microsoft Academic Search

    Jane L. Weissman

    Otalgia is ear pain. Ear disease causes pri- mary otalgia. Secondary (referred) otalgia is referred to the ear from disease in structures remote from the ear. Otalgia, especially referred otalgia, can be a diagnostic challenge. The radiologic approach to a patient with otalgia relies on the physical examination. If the otoscopic findings are abnormal, the computed tomographic (CT) or magnetic

  9. Purdue extensionGibberella Ear Rot Purdue extension

    E-print Network

    Holland, Jeffrey

    1 Purdue extensionGibberella Ear Rot BP-77-W Purdue extension d i s e a s e s o f c o r n Gibberella Ear Rot Authors: Charles Woloshuk Kiersten Wise www.btny.purdue.edu Photos by Charles Woloshuk Gibberella ear rot, or Gib ear rot, is caused by the fungus, Gibberella zeae (Fusarium graminearum

  10. Study of the ear in anencephaly

    Microsoft Academic Search

    D. K. Banerjee; S. K. Basu; Asok Dandapath; B. M. Choddhury

    1980-01-01

    The ears of 8 anencephalics were studied. No gross macroscopic abnormality in the development of the external, middle and\\u000a internal ears were detected except that the internal auditory canals appeared more of a furrow with a bony ledge at its base.\\u000a There was a malformed long process of incus with abnormal disposition of the round and oval windows below and

  11. CHRONIC ADMINISTRATION OF DOCOSAHEXAENOIC ACID OR EICOSAPENTAENOIC ACID, BUT NOT ARACHIDONIC ACID,

    E-print Network

    Wurtman, Richard

    CHRONIC ADMINISTRATION OF DOCOSAHEXAENOIC ACID OR EICOSAPENTAENOIC ACID, BUT NOT ARACHIDONIC ACID circulating precursors: choline; a pyrimidine (e.g. uridine); and a poly- unsaturated fatty acid, with UMP plus the omega-3 fatty acid docosa- hexaenoic acid (given by gavage), produces substantial in

  12. Effect of oxygen-derived free radicals on arachidonic acid turnover in isolated perfused rat lung

    SciTech Connect

    Jones, R.; Otani, H.; Das, D.K.

    1986-05-01

    Turnover of arachidonic acid in lung was studied by perfusing an isolated and ventilated rat lung in the presence of (/sup 14/C)-arachidonic acid for 30 min. Oxygen-derived free radicals were generated within the pulmonary circulation by the action of xanthine oxidase (XO) (0.1 ..mu../ml) on hypoxanthine (0.1 ..mu..mol/ml). Lung was also preperfused in the presence or absence of superoxide dismutase (SOD) (5 ..mu..g/ml) and catalase (5 ..mu..g/ml) prior to the addition of radiolabeled arachidonic acid and free radical generating system. After the perfusion was over, several biopsies were obtained and phospholipids were extracted and separated from one of the biopsies. Individual phospholipids were compared with known standards and counted for radioactivity. An appreciable amount of radioactivity was found in total phospholipids and in phosphatidyl choline and phosphatidyl inositol fractions in control lungs. Some radioactivity was also noticed in phosphatidyl ethanolamine fraction. The isotopic incorporation was significantly inhibited when lung was perfused in the presence of hypoxanthine and XO. The incorporation of (/sup 14/C)-radioactivity was restored to the control levels when lung was preperfused with SOD and catalase. These results suggest that oxygen radicals inhibit the arachidonic acid turnover in isolated and perfused rat lung.

  13. Individual variation and intraclass correlation in arachidonic acid and eicosapentaenoic acid in chicken muscle

    Microsoft Academic Search

    Anna Haug; Ingrid Olesen; Olav A Christophersen

    2010-01-01

    Chicken meat with reduced concentration of arachidonic acid (AA) and reduced ratio between omega-6 and omega-3 fatty acids has potential health benefits because a reduction in AA intake dampens prostanoid signaling, and the proportion between omega-6 and omega-3 fatty acids is too high in our diet. Analyses for fatty acid determination are expensive, and finding the optimal number of analyses

  14. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by antioxidants

    Microsoft Academic Search

    Miriam Alvarez-Guerra; Patrick Hannaert; Hamida Hider; Carlo Chiavaroli; Ricardo P Garay

    2003-01-01

    Arachidonic acid was investigated for its vascular permeabilizing potential in the rat peritoneal cavity and for its mechanism of action. The antagonistic potential of antioxidants (vitamin E, vitamin C and troxerutin) was also evaluated. Vascular permeability was equated to the rate of extravasation of Evans blue dye from plasma into the peritoneal cavity. Baseline permeability was linear up to 2

  15. Arachidonic acid metabolism in the platelets and neutrophils of diabetic rabbit and human subjects

    Microsoft Academic Search

    Greco

    1985-01-01

    An alteration of arachidonic acid metabolism to prostaglandins and leukotrienes from platelets and polymorphonuclear leukocytes respectively is evident in subjects with diabetes mellitus. There is evidence of altered platelet\\/vascular wall interactions in diabetes mellitus and evidence that polymorphonuclear leukocytes influence the vascular walls. Theories on the pathogenesis of atherosclerosis include both blood cells. Platelet hypersensitivity is evident in those platelets

  16. Effect of arachidonic and eicosapentaenoic acids on acute lung injury induced by hypochlorous acid

    Microsoft Academic Search

    H Wahn; N Ru?enauver; S Hammerschmidt

    2002-01-01

    Background: Hypochlorous acid (HOCl) is the main oxidant of activated polymorphonuclear neutrophil granulocytes (PMN) and generated by myeloperoxidase during respiratory burst. This study investigates the effects of HOCl on pulmonary artery pressure (PAP) and vascular permeability and characterises the influence of arachidonic acid (AA) and eicosapentaenoic acid (EPA) on the observed effects.Methods: HOCl (500, 1000, 2000 nmol\\/min) was continuously infused

  17. Development of the vertebrate inner ear.

    PubMed

    Rinkwitz, S; Bober, E; Baker, R

    2001-10-01

    The inner ear, also called the membranous labyrinth, contains the cochlea, which is responsible for the sense of hearing, and the vestibular apparatus, which is necessary for the sense of balance and gravity. The inner ear arises in the embryo from placodes, which are epithelial thickenings of the cranial ectoderm symmetrically located on either side of hindbrain rhombomeres 5 and 6. Placode formation in mice is first visible at the 12-somite stage and is controlled by surrounding tissues, the paraxial mesoderm and neural ectoderm. Diffusible molecules such as growth factors play an important role in this process. The activity of several genes confers the identity to the placodal cells. Subsequent cellular proliferation processes under influences from the adjacent hindbrain cause the inner ear epithelium to invaginate and form a vesicle called the otocyst. Combinatorial expression of several genes and diffusible factors secreted from the vesicle epithelium and hindbrain control specification of distinct inner ear compartments. Transplantation studies and inner ear in vitro cultures show that each of these compartments is already committed to develop unique inner ear structures. Later developmental periods are principally characterized by intrinsic differentiation processes. In particular, sensory patches differentiate into fully functional sensory epithelia, and the semicircular canals along with the cochlear duct are elaborated and ossified. PMID:11710453

  18. DIBROMOACETIC ACID-INDUCED ELEVATIONS IN CIRCULATING ESTRADIOL: EFFECTS IN BOTH CYCLING AND OVARIECTOMIZED/STEROID-PRIMED FEMALE RATS

    EPA Science Inventory

    RTD-03-031 Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations in Circulating Estradiol: Effects in Both Cycling and Ovariectomized/Steroid-primed Female Rats. Reproductive Toxicology (in press). Abstract Oral exposures to high concentrations of th...

  19. Nicotinic acid induces secretion of prostaglandin D 2 in human macrophages: An in vitro model of the niacin flush

    Microsoft Academic Search

    C. Daniel Meyers; Paul Liu; Vaijinath S. Kamanna; Moti L. Kashyap

    2007-01-01

    Nicotinic acid is a safe, broad-spectrum lipid agent shown to prevent cardiovascular disease, yet its widespread use is limited by the prostaglandin D2 (PGD2) mediated niacin flush. Previous research suggests that nicotinic acid-induced PGD2 secretion is mediated by the skin, but the exact cell type remains unclear. We hypothesized that macrophages are a source of nicotinic acid-induced PGD2 secretion and

  20. Vascular permeabilization by intravenous arachidonate in the rat peritoneal cavity: antagonism by ethamsylate.

    PubMed

    Hannaert, Patrick; Alvarez-Guerra, Miriam; Hider, Hamida; Chiavaroli, Carlo; Garay, Ricardo P

    2003-04-11

    The hemostatic agent, ethamsylate, inhibits arachidonic acid metabolism by a mechanism independent of cyclooxygenase activity and blocks carrageenan-induced rat paw edema. Here, ethamsylate was investigated for (i) in vivo actions on the free radical-dependent, permeabilizing responses to arachidonic acid and (ii) its antioxidant potential in vitro. Vascular permeability was equated to the extravasation rate of Evans blue from plasma into the rat peritoneal cavity. Antioxidant potential was investigated by classical in vitro tests for superoxide radicals, hydroxyl radicals (OH(.)), and nitric oxide. Intravenous ethamsylate induced a very important and significant reduction of permeability responses to arachidonate, both when given preventively and cumulatively. Thus, (i) ethamsylate significantly reversed arachidonate-induced permeabilization, even at the lowest dose tested (44+/-5% at 10 mg/kg) and (ii) a maximal reversal (about 70%) was reached between 50 and 200 mg/kg ethamsylate. In contrast, ethamsylate (100 mg/kg) was unable to antagonize the vascular permeabilization induced by serotonin (5-HT). In antioxidant assays, ethamsylate showed scavenging properties against hydroxyl radicals generated by the Fenton reaction (H(2)O(2)/Fe(2+)) even at 0.1 microM (-20+/-3%). OH(.) scavenging by ethamsylate reached 42+/-8% at 10 microM and 57+/-7% at 1 mM and was comparable to that of reference compounds (vitamin E, troxerutin, and mannitol). Conversely, ethamsylate was a poor scavenger of superoxide and nitric oxide radicals. In conclusion, intravenous ethamsylate potently antagonized the peritoneal vascular permeabilization induced by arachidonate, an action likely due to its antioxidant properties, particularly against hydroxyl radical. Such a mechanism can explain previous observations that ethamsylate inhibits carrageenan-induced rat paw edema. Whether it also participates in the hemostatic action of ethamsylate deserves further investigation. PMID:12679158

  1. An Eye for an Ear and an Ear for an Eye: Bidirectional Control in Virtual Multimedia

    E-print Network

    Jacquemin, Christian

    An Eye for an Ear and an Ear for an Eye: Bidirectional Control in Virtual Multimedia Instrument. 1. Control, Mapping, and Interaction in Virtual Multimedia Instruments Recent trends in Human and Virtual Reality. It gives birth to new instruments applied to a wide range of human activities

  2. Prolonged Radiant Exposure of the Middle Ear during Transcanal Endoscopic Ear Surgery.

    PubMed

    Shah, Parth V; Kozin, Elliott D; Remenschneider, Aaron K; Dedmon, Matthew M; Nakajima, Hideko Heidi; Cohen, Michael S; Lee, Daniel J

    2015-07-01

    Transcanal endoscopic ear surgery (EES) provides a high-resolution, wide-field view of the middle ear compared with the conventional operating microscope, reducing the need for a postauricular incision or mastoidectomy. Our group has shown in cadaveric human temporal bone studies that radiant energy from the endoscope tip can quickly elevate temperatures of the tympanic cavity. Elevated temperatures of the middle ear are associated with acute auditory brainstem response shifts in animal models. In EES, proposed methods to decrease middle ear temperature include frequent removal of the endoscope and the use of suction to rapidly dissipate heat; however, the routine application of such cooling techniques remains unknown. Herein, we aim to quantify the duration that the tympanic cavity is typically exposed to the endoscope during routine endoscopic middle ear surgery. We find that the tympanic cavity is exposed to the endoscope without a cooling mechanism for a prolonged period of time. PMID:25779471

  3. Passive and active middle ear implants

    PubMed Central

    Beutner, Dirk; Hüttenbrink, Karl-Bernd

    2011-01-01

    Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants. PMID:22073102

  4. Extracellular Melanin in Inflammatory Middle Ear Disease

    PubMed Central

    Fritz, Mark; Roehm, Pamela C.; Bannan, Michael A.; Lalwani, Anil K.

    2015-01-01

    Objective Melanin is a pigmented polymer with a known role in dermal solar protection. In vertebrates, melanogenesis has been reported in leukocyte population suggesting a potential role in innate immunity. In this study, we report the novel finding of melanin associated with chronic inflammation and speculate on its potential role in the middle ear and mastoid. Study Design Retrospective review of case series Methods Medical records of 6 patients who demonstrated melanin in the ear were reviewed. Results Six patients, ages from 1 to 63 were identified with extracellular melanin within middle ear and/or mastoid air cells at time of surgery. Intraoperative findings included cholesteatoma (n=3), chronic suppurative OM (n=2), and coalescent mastoiditis (n=1). Histologically, extracellular melanin was identified by Fontana-Masson stain; absence of melanocytes was confirmed by the absence of Melan-A and Prussian Blue stain. One patient had a positive stain for CD163 (a marker for macrophages). Conclusion This case series is the first demonstration of extracellular melanin within middle ear mucosa not associated with melanocytes or metastatic melanocytic lesions. The presence of melanin is either a variant of normal anatomy, a pathway of cholesteatoma formation, or a marker of the inflammatory immune response. Melanin's presence in the setting of inflammation suggests that there may be a heretofore unreported link between the pigmentary and immune systems in the ear. PMID:24999501

  5. Ear Acupuncture in European Traditional Medicine

    PubMed Central

    Firenzuoli, Fabio

    2007-01-01

    Auricular acupuncture is a diagnostic and treatment system based on normalizing the body's dysfunction through stimulation of definite points on the ear. Rudimentary forms of acupuncture which probably arose during the Stone Age have survived in many parts of the world right down to present day. It was used in the ancient Egypt, Rome, Greece and all the Mediterranean area. It is a microacupuncture technique similar to reflexology, and was first described in France in 1950 by Paul Nogier who is considered the Father of modern ear acupuncture. It was speculated that the technique works because groups of pluripotent cells contain information from the whole organism and create regional organization centers representing different parts of the body. Nevertheless stimulation of a reflex point in the ear seems relieve symptoms of distant pathologies. Modern research is confirming the efficacy of ear acupuncture for analgesia and anxiety related disease, while tobacco dependence and other substance abuse still need confirmation. Actually main methodological problems with auricular acupuncture are that exist too many maps with little agreement regarding point location in the ear, and that the correspondence or reflex systems does not correlated with modern knowledge of anatomy and physiology. PMID:18227925

  6. The acid-induced folded state of Sac7d is the native state.

    PubMed Central

    Bedell, J. L.; McCrary, B. S.; Edmondson, S. P.; Shriver, J. W.

    2000-01-01

    Sac7d unfolds at low pH in the absence of salt, with the greatest extent of unfolding obtained at pH 2. We have previously shown that the acid unfolded protein is induced to refold by decreasing the pH to 0 or by addition of salt (McCrary BS, Bedell J. Edmondson SP, Shriver JW, 1998, J Mol Biol 276:203-224). Both near-ultraviolet circular dichroism spectra and ANS fluorescence enhancements indicate that the acid- and salt-induced folded states have a native fold and are not molten globular. 1H,15N heteronuclear single quantum coherence NMR spectra confirm that the native, acid-, and salt-induced folded states are essentially identical. The most significant differences in amide 1H and 15N chemical shifts are attributed to hydrogen bonding to titrating carboxyl side chains and through-bond inductive effects. The 1H NMR chemical shifts of protons affected by ring currents in the hydrophobic core of the acid- and salt-induced folded states are identical to those observed in the native. The radius of gyration of the acid-induced folded state at pH 0 is shown to be identical to that of the native state at pH 7 by small angle X-ray scattering. We conclude that acid-induced collapse of Sac7d does not lead to a molten globule but proceeds directly to the native state. The folding of Sac7d as a function of pH and anion concentration is summarized with a phase diagram that is similar to those observed for other proteins that undergo acid-induced folding except that the A-state is encompassed by the native state. These results demonstrate that formation of a molten globule is not a general property of proteins that are refolded by acid. PMID:11106160

  7. Clavulanic acid induces penile erection and yawning in male rats: comparison with apomorphine.

    PubMed

    Sanna, Fabrizio; Melis, Maria Rosaria; Angioni, Laura; Argiolas, Antonio

    2013-02-01

    The beta-lactamase inhibitor clavulanic acid induced penile erection and yawning in a dose dependent manner when given intraperitoneally (IP, 0.05-5mg/kg), perorally (OS, 0.1-5mg/kg) and intracereboventricularly (ICV, 0.01-5 ?g/rat) to male rats. The effect resembles that of the dopamine receptor agonist apomorphine given subcutaneously (SC) (0.02-0.25mg/kg), although the responses of the latter followed a U inverted dose-response curve, disappearing at doses higher than 0.1mg/kg. Clavulanic acid responses were reduced by about 55% by haloperidol, a dopamine D2 receptor antagonist (0.1mg/kg IP), and by d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin, an oxytocin receptor antagonist (2 ?g/rat ICV), both given 15 min before clavulanic acid. A higher reduction of clavulanic acid responses (more than 80%) was also found with morphine, an opioid receptor agonist (5mg/kg IP), and with mianserin, a serotonin 5HT(2c) receptor antagonist (0.2mg/kg SC). In contrast, no reduction was found with naloxone, an opioid receptor antagonist (1mg/kg IP). The ability of haloperidol, d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin and morphine to reduce clavulanic acid induced penile erection and yawning suggests that clavulanic acid induces these responses, at least in part, by increasing central dopaminergic neurotransmission. Dopamine in turn activates oxytocinergic neurotransmission and centrally released oxytocin induces penile erection and yawning. However, since both penile erection and yawning episodes were reduced not only by the blockade of central dopamine and oxytocin receptors and by the stimulation of opioid receptors, which inhibits oxytocinergic neurotransmission, but also by mianserin, an increase of central serotonin neurotransmission is also likely to participate in these clavulanic acid responses. PMID:23234836

  8. Aberrant Carotid Artery in the Middle Ear

    PubMed Central

    Yeti?er, Sertaç

    2015-01-01

    Background: Carotid artery abnormality in the middle ear is a rare clinical condition. Recognition of the problems related with this abnormality is important since it may mimic vascular tumors. Any intervention with incomplete evaluation can be fatal. Case Report: A 23-year-old girl with carotid abnormality and sensorineural hearing loss, unsteadiness and tinnitus is presented. She was followed for 2 months elsewhere assuming that she had Meniere’s disease and had previously received some medication for otitis media with effusion. Conclusion: Tomography and magnetic resonance imaging of the temporal bone are very helpful for visualization of an aberrant carotid in the middle ear. Radiological presentations are the reduced caliber of the aberrant carotid, an absence of cranial opening of carotid canal, tubular coursing along the medial wall of the middle ear in continuity with the horizontal carotid canal, dehiscence of the lateral carotid plate and enlargement of the tympanic canalicus. PMID:25759782

  9. Ear damage caused by leisure noise.

    PubMed

    Maassen, M.; Babisch, W.; Bachmann, K. D.; Ising, H.; Lehnert, G.; Plath, P.; Plinkert, P.; Rebentisch, E.; Schuschke, G.; Spreng, M.; Stange, G.; Struwe, V.; Zenner, H. P.

    2001-01-01

    Noise is a health risk. Recent findings suggest that leisure noise is a substantial danger especially to children, teenagers and young adults. Epidemiological studies of teenagers with no occupational noise exposure show an increasing number with a substantial and measurable irreversible inner ear damage. This is basically due to the wide spread exposition to very loud toys (pistols and squibs), crackers and exposure to electronically amplified music, e.g. from personal cassette players (PCP), at discos or concerts etc. Protection against irreversible ear damage by leisure noise has an important impact in preventive medical care. Therefore the general public must be informed that loud leisure activities may cause damage to the ear. In order to protect children, young people and adults, the legislature ought to set limits for sound levels in discos, concert halls and for music equipment and toys by establishing the necessary standards and regulations. PMID:12678931

  10. Precise individualized armature for ear reconstruction

    NASA Astrophysics Data System (ADS)

    Evenhouse, Raymond J.; Chen, Xiaoming

    1991-04-01

    The cosmetic result of an ear restored surgically or via prosthetics is dependent on the surgeon''s ability to carve a precise cartilage armature at the time of surgery or the prosthetist''s ability to sculpt in wax an exact duplicate of the patient''s " missing" ear. Introducing CAD/CAM technology into the process benefits the esthetic outcome of these procedures. By utilizing serial section information derived from CAT MRI or moulage techniques a mirrorimage of the patient''s " donor" ear is generated. The resulting earform data is then used for the design of a cartilage armature produced by multi-axis milling or to produce by stereolithography a model which serves as the basis for a prosthesis.

  11. Endoscopic anatomy of the pediatric middle ear.

    PubMed

    Isaacson, Glenn

    2014-01-01

    Traditionally, otologists have aimed to produce a clean, dry, safe ear with the best possible hearing result. More recently, "less invasively" has been added to this list of goals. The development of small-diameter, high-quality rigid endoscopes and high-definition video systems has made totally endoscopic, transcanal surgery a reality in adult otology and a possibility in pediatric otology. This article reviews the anatomy of the pediatric middle ear and its surrounding airspaces and structures based on the work of dozens of researchers over the past 50 years. It will focus on the developmental changes in ear anatomy from birth through the first decade, when structure and function change most rapidly. Understanding the limits and possibilities afforded by new endoscopic technologies, the pediatric otologist can strive for results matching or exceeding those achieved by more invasive surgical approaches. PMID:24154745

  12. Middle ear cholesteatoma in 11 dogs

    PubMed Central

    Greci, Valentina; Travetti, Olga; Di Giancamillo, Mauro; Lombardo, Rocco; Giudice, Chiara; Banco, Barbara; Mortellaro, Carlo M.

    2011-01-01

    Middle ear cholesteatoma is a rare condition in dogs with chronic otitis. Otorrhea, otodinia, and pain on temporomandibular joint palpation are the most common clinical signs. Neurological abnormalities are often detectable. Computed tomography reveals the presence of an expansive and invasive unvascularized lesion involving the tympanic cavity and the bulla, with little or no contrast enhancement after administration of contrast mediu. Video-otoscopy may detect pearly growth or white/yellowish scales in the middle ear cavity. Surgery is the only therapy but is associated with a high risk of recurrence. PMID:22131579

  13. Middle ear cholesteatoma in 11 dogs.

    PubMed

    Greci, Valentina; Travetti, Olga; Di Giancamillo, Mauro; Lombardo, Rocco; Giudice, Chiara; Banco, Barbara; Mortellaro, Carlo M

    2011-06-01

    Middle ear cholesteatoma is a rare condition in dogs with chronic otitis. Otorrhea, otodinia, and pain on temporomandibular joint palpation are the most common clinical signs. Neurological abnormalities are often detectable. Computed tomography reveals the presence of an expansive and invasive unvascularized lesion involving the tympanic cavity and the bulla, with little or no contrast enhancement after administration of contrast mediu. Video-otoscopy may detect pearly growth or white/yellowish scales in the middle ear cavity. Surgery is the only therapy but is associated with a high risk of recurrence. PMID:22131579

  14. Arachidonic acid-dependent inhibition of adipocyte differentiation requires PKA activity and is associated with sustained expression of cyclooxygenases

    Microsoft Academic Search

    Rasmus K. Petersen; Claus Jørgensen; Arild C. Rustan; Livar Frøyland; Karin Muller-Decker; Gerhard Furstenberger; Rolf K. Berge; Karsten Kristiansen; Lise Madsen

    2003-01-01

    Arachidonic acid inhibits adipocyte differentia- tion of 3T3-L1 cells via a prostaglandin synthesis-dependent pathway. Here we show that this inhibition requires the presence of a cAMP-elevating agent during the first two days of treatment. Suppression of protein kinase A activity by H-89 restored differentiation in the presence of arachi- donic acid. Arachidonic acid treatment led to a prolonged activation of

  15. Effects of omega-3 fatty acids on vascular smooth muscle cells: Reduction in arachidonic acid incorporation into inositol phospholipids

    Microsoft Academic Search

    Nagender R. Yerram; Arthur A. Spector

    1989-01-01

    A rapid increase in arachidonic acid incorporation into phosphatidylinositol (PI) occurred following exposure of cultured\\u000a porcine pulmonary artery smooth muscle cells to calcium ionophore A23187. This response was specific for PI and phosphatidic\\u000a acid; none of the other phosphoglycerides showed any increase in arachidonic acid incorporation. The incorporation of [3H]inositol also was increased, indicating that complete synthesis of PI rather

  16. Metabolism of arachidonic acid in phorbol ester, interferon and dimethyl sulfoxide differentiation induced U937 cells

    SciTech Connect

    Ou, D.W.; Wiederhold, M.D.

    1986-03-05

    U937, a human macrophage cell line can metabolize arachidonic acid to a prostaglandin E2-like substance, and an unidentified lipoxygenase product. This metabolism occurs at very low levels however since these cells have low lipase and fatty acid oxygenase activities. The investigated the appearance of these enzyme activities during differentiation induced by phorbol-12-myristate-13-acetate (PMA), human gamma interferon (INF), and dimethyl sulfoxide (DMSO) on days 1,3 and 5 of stimulation using /sup 3/H-arachidonic acid (/sup 3/H-AA). Culture supernatants were analyzed for free /sup 3/H-AA and /sup 3/H metabolites by radio-thin layer chromatography (/sup 3/H-MET). The increasing percentage of /sup 3/H-AA release suggests the appearance of phospholipase activity during differentiation.

  17. Diversity of endothelium-derived vasocontracting factors--arachidonic acid metabolites.

    PubMed

    Kurahashi, Kazuyoshi; Nishihashi, Tsuyoshi; Trandafir, Cristina Corina; Wang, Ai-Min; Murakami, Shizuka; Ji, Xu

    2003-11-01

    Vascular endothelium releases vasocontracting and/or vasorelaxing substances. Here, we report the diversity of endothelium-derived vasocontracting factors (EDCFs), arachidonic acid metabolites, and discuss the pathophysiological significance. In the canine basilar artery and the rabbit intrapulmonary artery, acetylcholine-induced contractions (ACh-induced EDC) are due to endothelial thromboxane A2 (TXA2) (TXA2-type). The ACh-induced EDC in the rabbit coronary artery is due to endothelial leukotrienes (LTs) (LTs-type). In addition, in the rat coronary artery, nicotine and noradrenaline (NAd)-induced EDCs are due to endothelial COX-metabolites (COX metabolite-type). These arachidonic acid metabolites derived from endothelium (activation by vasoactive substances including ACh, NAd and nicotine) cause a contraction of vascular smooth muscle cells and may disturb the local circulation. These EDCFs (TXA2, LTs and COX-metabolites) may be involved in the pathophysiology of cardiovascular immuno-inflammatory diseases. PMID:14627486

  18. Distribution of arachidonic and eicosapentaenoic acids in the lipids of mosses.

    PubMed

    Gellerman, J L; Anderson, W H; Richardson, D G; Schlenk, H

    1975-05-22

    Lipid classes from four species of mosses, Mnium cuspidatum, and Mnium medium from Minnesota, and Hylocomium splendens and Pleurozium schreberi from Alaska, were analyzed. The total lipids of all species contained 30-40% arachidonic and eicosapentaenoic acids. However, the lipids from the Alaskan mosses contained about 75% neutral lipids (triacylglycerols, steryl esters and wax esters) whereas the lipids of the other species contained only 20% or less of these neutral lipids. Consistently, monogalactosyldiacylglycerols and phosphatidylethanol-amines were enriched in arachidonic acid and the galactolipids in eicosapentaenoic acid. The distribution of these acids in the phospholipids shows some preference for position 2. Together, the highly unsaturated C20 acids represented 80% of acyl groups in steryl esters. In triacylglycerols they were at average levels, while they were much less in sulfolipids and phosphatidylglycerols. Wax esters contained very little of the highly unsaturated acids but appreciable amounts of phytol and phytenic acid were found as wax constituents. PMID:1138900

  19. The involvement of endoplasmic reticulum stress in bile acid-induced hepatocellular injury

    PubMed Central

    Adachi, Tetsuo; Kaminaga, Tomoyuki; Yasuda, Hiroyuki; Kamiya, Tetsuro; Hara, Hirokazu

    2014-01-01

    Secondary bile acids produced by enteric bacteria accumulate to high levels in the enterohepatic circulation and may contribute to the pathogenesis of hepatocellular injury. Relative hydrophobicity has been suggested to be an important determinant of the biological properties of these compounds, although the mechanism by which bile acids induce pathogenesis is not fully understood. On the other hand, endoplasmic reticulum stress has been shown to be involved in the induction and development of various pathogenic conditions. In this report, we demonstrated that the intensities of cytotoxicity and endoplasmic reticulum stress in HepG2 cells triggered by the bile acids tested were largely dependent on their hydrophobicity. The activation of caspase-3 and DNA fragmentation by treatment with chenodeoxycholic acid showed the contribution of apoptosis to cytotoxicity. Increases in intracellular calcium levels and the generation of reactive oxygen species stimulated by treatment with chenodeoxycholic acid contributed to endoplasmic reticulum stress. Bile acids also induced transforming growth factor-?, a potent profibrogenic factor, which is known to induce hepatocyte apoptosis and ultimately liver fibrosis. In conclusion, our study demonstrated that bile acids induced endoplasmic reticulum stress, which in turn stimulated apoptosis in HepG2 cells, in a hydrophobicity-dependent manner. PMID:24688223

  20. Nucleic acid-induced antiviral immunity in invertebrates: an evolutionary perspective.

    PubMed

    Wang, Pei-Hui; Weng, Shao-Ping; He, Jian-Guo

    2015-02-01

    Nucleic acids derived from viral pathogens are typical pathogen associated molecular patterns (PAMPs). In mammals, the recognition of viral nucleic acids by pattern recognition receptors (PRRs), which include Toll-like receptors (TLRs) and retinoic acid-inducible gene (RIG)-I-like receptors (RLRs), induces the release of inflammatory cytokines and type I interferons (IFNs) through the activation of nuclear factor ?B (NF-?B) and interferon regulatory factor (IRF) 3/7 pathways, triggering the host antiviral state. However, whether nucleic acids can induce similar antiviral immunity in invertebrates remains ambiguous. Several studies have reported that nucleic acid mimics, especially dsRNA mimic poly(I:C), can strongly induce non-specific antiviral immune responses in insects, shrimp, and oyster. This behavior shows multiple similarities to the hallmarks of mammalian IFN responses. In this review, we highlight the current understanding of nucleic acid-induced antiviral immunity in invertebrates. We also discuss the potential recognition and regulatory mechanisms that confer non-specific antiviral immunity on invertebrate hosts. PMID:24685509

  1. Polyunsaturated Branched-Chain Fatty Acid Geranylgeranoic Acid Induces Unfolded Protein Response in Human Hepatoma Cells

    PubMed Central

    Iwao, Chieko; Shidoji, Yoshihiro

    2015-01-01

    The acyclic diterpenoid acid geranylgeranoic acid (GGA) has been reported to induce autophagic cell death in several human hepatoma-derived cell lines; however, the molecular mechanism for this remains unknown. In the present study, several diterpenoids were examined for ability to induce XBP1 splicing and/or lipotoxicity for human hepatoma cell lines. Here we show that three groups of diterpenoids emerged: 1) GGA, 2,3-dihydro GGA and 9-cis retinoic acid induce cell death and XBP1 splicing; 2) all-trans retinoic acid induces XBP1 splicing but little cell death; and 3) phytanic acid, phytenic acid and geranylgeraniol induce neither cell death nor XBP1 splicing. GGA-induced ER stress/ unfolded protein response (UPR) and its lipotoxicity were both blocked by co-treatment with oleic acid. The blocking activity of oleic acid for GGA-induced XBP1 splicing was not attenuated by methylation of oleic acid. These findings strongly suggest that GGA at micromolar concentrations induces the so-called lipid-induced ER stress response/UPR, which is oleate-suppressive, and shows its lipotoxicity in human hepatoma cells. PMID:26186544

  2. The timing of acid-induced increase in saliva secretion in transplanted submandibular glands.

    PubMed

    Liu, X J; Li, M; Su, J Z; Xie, Z; Yu, G Y

    2015-08-01

    The purpose of this study was to determine the timing of acid-induced increase in saliva secretion and to investigate the possibility of parasympathetic reinnervation of transplanted submandibular glands (SMGs). Citric acid stimulation-induced changes in secretion of transplanted SMGs were evaluated in 27 patients who underwent SMG transplantation for keratoconjunctivitis sicca (KCS); (99m)Tc scintigraphy and Schirmer tests were done at 1, 3, 6, and 9 months after transplantation. Acetylcholinesterase staining was conducted to confirm the presence of parasympathetic reinnervation in three SMGs at 6 and 9 months after transplantation. Schirmer tests showed significantly increased secretion of the transplanted SMGs after acid stimulation at 6 and 9 months, but not at 1 and 3 months. On (99m)Tc scintigraphy, no decline was detected on the dynamic time-activity curve after acid stimulation at 1 and 3 months, but a decline was detected in nine glands at 6 months and in 19 glands at 9 months. No decline was observed in the remaining eight glands at 9 months after transplantation. The histology findings were consistent with scintigraphy results. In conclusion, acid-induced increase in saliva secretion occurs at ?6 months after SMG transplantation, and parasympathetic reinnervation of the transplanted SMG might occur. PMID:25697065

  3. Arachidonic acid supplementation dose-dependently reverses the effects of a butter-enriched diet in rats.

    PubMed

    Steel, M S; Naughton, J M; Hopkins, G W; Sinclair, A J; O'Dea, K

    1993-03-01

    Male Sprague Dawley rats were fed a butter-enriched diet (50% fat) for 2 weeks which was supplemented orally with 9, 18, 36, or 72 mg/day of ethyl arachidonate for a further 2 weeks. The control group of animals were fed a 5% fat diet for 4 weeks. Aortic prostacyclin (PGI2) production, platelet aggregation and thromboxane A2 (TXA2) production and plasma and aortic phospholipid (PL) fatty acids were measured. 50% butter-feeding resulted in a significant reduction in aortic PGI2 production and collagen-induced platelet aggregation and TXA2 production. These changes were accompanied by a reduction in plasma and aortic PL arachidonic acid levels and an increase in eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), 5,8,11-eicosatrienoic acid (ETA) and dihomo-gamma-linolenic acid (DGLA). These changes in prostanoid production, platelet aggregation and PL fatty acid composition were dose-dependently reversed by the daily oral administration of ethyl arachidonate (9, 18, 36, or 72 mg). The threshold dose being as little as 9 mg of ethyl arachidonate/rat/day for reversal of PL fatty acid composition, collagen-induced platelet aggregation and TXA2 production, and 18 mg of ethyl arachidonate/rat/day for reversal of aortic PGI2 production. Full reversal was seen generally with 36 or 72 mg of ethyl arachidonate/rat/day. The data highlight the responsiveness of tissue eicosanoid production to small quantities (ppm) of dietary eicosanoid precursors. PMID:8469684

  4. Arachidonic acid stimulates extracellular Ca(2+) entry in rat pancreatic beta cells via activation of the noncapacitative arachidonate-regulated Ca(2+) (ARC) channels.

    PubMed

    Yeung-Yam-Wah, Valerie; Lee, Andy K; Tse, Frederick W; Tse, Amy

    2010-01-01

    Arachidonic acid (AA) is generated in the pancreatic islets during glucose stimulation. We investigated whether AA activated extracellular Ca(2+) entry in rat pancreatic beta cells via a pathway that was independent of the activation of voltage-gated Ca(2+) channels. The AA triggered [Ca(2+)](i) rise did not involve activation of GPR40 receptors or AA metabolism. When cells were voltage clamped at -70mV, the AA-mediated intracellular Ca(2+) release was accompanied by extracellular Ca(2+) entry. AA accelerated the rate of Mn(2+) quench of indo-1 fluorescence (near the Ca(2+)-independent wavelength of indo-1), reflecting the activation of a Ca(2+)-permeable pathway. The AA-mediated acceleration of Mn(2+) quench was inhibited by La(3+) but not by 2-APB (a blocker of capacitative Ca(2+) entry), suggesting the involvement of arachidonate-regulated Ca(2+) (ARC) channels. Consistent with this, intracellular application of the charged membrane-impermeant analog of AA, arachidonyl-coenzyme A (ACoA) triggered extracellular Ca(2+) entry, as well as the activation of a La(3+)-sensitive small inward current (1.7pA/pF) at -70mV. Our results indicate that the activation of ARC channels by intracellular AA triggers extracellular Ca(2+) entry. This action may contribute to the effects of AA on Ca(2+) signals and insulin secretion in rat beta cells. PMID:20018371

  5. Assessment of the arachidonic acid content in foods commonly consumed in the American diet

    Microsoft Academic Search

    Laura Taber; Chun-Hung Chiu; Jay Whelan

    1998-01-01

    Arachidonic acid (AA) is an extremely important fatty acid involved in cell regulation. When provided in the diet, it is cogently\\u000a incorporated in membrane phospholipids and enhances eicosanoid biosynthesis in vivo and in vitro; however, controversy exists as to the levels of AA in food and in the diet. This study determined the amount of AA in cooked\\u000a and raw

  6. Differential stimulation of luminol-enhanced chemiluminescence (CL) and arachidonic acid metabolism in rat peritoneal neutrophils

    SciTech Connect

    Sturm, R.J.; Adams, L.M.; Cullinan, C.A.; Berkenkopf, J.W.; Weichman, B.M.

    1986-03-05

    Phorbol 12-myristate, 13-acetate (PMA) induced the production of radical oxygen species (ROS) from rat peritoneal neutrophils as assessed by CL. ROS generation occurred in a time- (maximum at 13.5 min) and dose- (concentration range of 1.7-498 nM) related fashion. However, 166 nM PMA did not induce either cyclooxygenase (CO) or lipoxygenase (LPO) product formation by 20 min post-stimulation. Conversely, A23187, at concentrations between 0.1 and 10 ..mu..M, stimulated both pathways of arachidonic acid metabolism, but had little or no effect upon ROS production. When suboptimal concentrations of PMA (5.5 nM) and A23187 (0.1-1 ..mu..M) were coincubated with the neutrophils, a synergistic ROS response was elicited. However, arachidonic acid metabolism in the presence of PMA was unchanged relative to A12187 alone. Nordihydroguaiaretic acid (NDGA) inhibited both PMA-induced CL (IC/sub 50/ = 0.9 ..mu..M) and A23187-induced arachidonic acid metabolism (IC/sub 50/ = 1.7 ..mu..M and 6.0 ..mu..M for LPO and CO, respectively). The mixed LPO-CO inhibitor, BW755C, behaved in a qualitatively similar manner to NDGA, whereas the CO inhibitors, indomethacin, piroxicam and naproxen had no inhibitory effect on ROS generation at concentrations as high as 100 ..mu..M. These results suggest that NDGA and BW755C may inhibit CL and arachidonic acid metabolism by distinct mechanisms in rat neutrophils.

  7. Mechanisms of coronary vasoconstriction induced by Na arachidonate in experimentally diabetic dogs

    Microsoft Academic Search

    L. Sterin-Borda; E. Borda; E. J. del Castillo; M. F. Gimeno; A. L. Gimeno

    1982-01-01

    Summary Na arachidonate (NaA) enhanced the resting basal tone of isolated coronary arteries from diabetic dogs and depressed it in coronary arteries from normal controls. Inhibitors of thromboxane A2 biosynthesis and of lipoxygenases abolished the vasoconstrictor effect of NaA on diabetic arteries, whereas inhibitors of cyclooxygenase activity and PGI2 biosynthesis blocked the vasodilating action of NaA on normal arteries.

  8. Topiramate does not alter expression in rat brain of enzymes of arachidonic acid metabolism

    Microsoft Academic Search

    Sandra Ghelardoni; Richard P. Bazinet; Stanley I. Rapoport; Francesca Bosetti

    2005-01-01

    Rationale: When administered chronically to rats, drugs that are effective in bipolar disorder—lithium and the anticonvulsants, valproic acid and carbamazepine —have been shown to downregulate the expression of certain enzymes involved in brain arachidonic acid (AA) release and cyclooxygenase (COX)-mediated metabolism. Phase II clinical trials with the anticonvulsant topiramate (2,3:4,5-bis-O-(1-methylethylidene)-beta-D-fructopyranose sulfamate) suggest that this drug may also be effective for

  9. The production potential of eicosapentaenoic and arachidonic acids by the red alga Porphyridium cruentum

    Microsoft Academic Search

    Zvi Cohen

    1990-01-01

    The red microalgaPorphyridium cruentum is a new source for eicosapentanoic acid (EPA) and arachidonic acid (AA) fatty acids of potential pharmaceutical value. The\\u000a conditions leading to a high content of either fatty acid were investigated. The highest EPA content was obtained under conditions\\u000a resulting in high growth rate (2.4% of ash free dry weight in Strain 1380-1d). High AA content

  10. The role of antioxidants in models of inflammation: Emphasis on l -arginine and arachidonic acid metabolism

    Microsoft Academic Search

    M. Kapoor; A. N. Clarkson; B. A. Sutherland; I. Appleton

    2005-01-01

    Inflammatory processes are made up of a multitude of complex cascades. Under physiological conditions these processes aid\\u000a in tissue repair. However, under pathophysiological environments, such as wound healing and hypoxia-ischaemia (HI), inflammatory\\u000a mediators become imbalanced, resulting in tissue destruction. This review addresses the changes in reactive oxygen species\\u000a (ROS), l-arginine and arachidonic acid metabolism in wound healing and HI and

  11. Effects of two different inhibitors of the arachidonic acid metabolism on platelet sequestration in endotoxic shock

    Microsoft Academic Search

    Gisli H. Sigurdsson; Hussein A. F. Youssef; Azu Owunnwanne

    1994-01-01

    Metabolites of arachidonic acid are known to play an important part in the pathogenesis of organ injury in endotoxic shock.\\u000a We compared the effects of the classical cyclooxygenase inhibitor aspirin with that of the dual cyclooxygenase and lipoxygenase\\u000a inhibitor ketoprofen on the behavior of platelets tagged with111In-labeled oxine in multiple organs during endotoxin shock. Three groups of sheep (n=7 in

  12. A new dual inhibitor of arachidonate metabolism isolated from Helichrysum italicum.

    PubMed

    Sala, Araceli; Recio, M Carmen; Schinella, Guillermo R; Máñez, Salvador; Giner, Rosa M; Ríos, José-Luis

    2003-01-24

    Six acetophenones (1-6) and one gamma-pyrone (7), previously isolated from Helichrysum italicum, were tested for their ability to inhibit enzymatic and non-enzymatic lipid peroxidation, the stable 1,1-diphenyl-2-pycryl-hydrazyl free radical, superoxide scavenging and arachidonic acid metabolism. In addition, they were studied in different experimental models such as the chronic inflammation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA), the phospholipase A(2)-induced mouse paw oedema test, the carrageenan-induced mouse paw oedema test, and the writhing induced by acetic acid in the mouse. Of the assayed compounds, only 1 inhibited enzymatic lipid peroxidation but had no effect on non-enzymatic lipid peroxidation. None of them scavenged the superoxide radical. Study of the inhibition of arachidonic acid metabolism demonstrated that 1 was an inhibitor of both cyclooxygenase and 5-lipoxygenase, whereas 2 was a selective inhibitor of 5-lipoxygenase. In the assay of phospholipase A(2)-induced mouse paw oedema, the gamma-pyrone derivative inhibited oedema formation, showing a similar profile to that obtained with cyproheptadine. The acetophenones were effective at 30 and 60 min. In the carrageenan test, acetophenone 1 gave the best results and had analgesic effects in the acetic acid writhing test. In conclusion acetophenone 1 (4-hydroxy-3-(3-methyl-2-butenyl)acetophenone) is a new dual inhibitor of arachidonate metabolism, and could be a useful tool for obtaining anti-inflammatory and analgesic drugs. PMID:12559384

  13. 21 CFR 874.4140 - Ear, nose, and throat bur.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...and throat bur. (a) Identification. An ear, nose, and throat bur is a device consisting of an interchangeable drill bit that is intended for use in an ear, nose, and throat electric or pneumatic surgical drill (§ 874.4250) for...

  14. 21 CFR 874.4140 - Ear, nose, and throat bur.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...and throat bur. (a) Identification. An ear, nose, and throat bur is a device consisting of an interchangeable drill bit that is intended for use in an ear, nose, and throat electric or pneumatic surgical drill (§ 874.4250) for...

  15. 21 CFR 874.4140 - Ear, nose, and throat bur.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...and throat bur. (a) Identification. An ear, nose, and throat bur is a device consisting of an interchangeable drill bit that is intended for use in an ear, nose, and throat electric or pneumatic surgical drill (§ 874.4250) for...

  16. Getting Teens to Read with Their Ears

    ERIC Educational Resources Information Center

    Fues, Marianne Cole

    2009-01-01

    Audiobooks have been around for years in various formats, like cassette tapes and CDs. This article describes a new type of audiobook on the market which is generating an interest in "reading." The device, called Playaway, is the size of a MP3 player and comes with a lanyard and ear buds. Buttons on the back of the player control the speed and…

  17. Mule Ear Drapery in Jewel Cave

    USGS Multimedia Gallery

    Jewel Cave is currently the 3rd most extensive cave network in the world. It is believed to have formed completely underwater, thus leading to the extensive coating of calcite crystals. In the center of this image, a cave formation known as mule-ear drapery can be seen....

  18. Do Your Ears Pop in Space?

    Microsoft Academic Search

    Robert Lambourne

    1997-01-01

    R Mike Mullane is a US astronaut who has flown into space three times on the Space Shuttle. He resigned from NASA in 1990 and has since pursued a career as a professional speaker and author. Do Your Ears Pop in Space? is his third book, and is based on the simple idea of writing down the 500 questions he

  19. Magnetic Nanoparticles: Inner Ear Targeted Molecule Delivery and Middle Ear Implant

    Microsoft Academic Search

    Richard D. Kopke; Ronald A. Wassel; Fadee Mondalek; Brian Grady; Kejian Chen; Jianzhong Liu; Don Gibson; Kenneth J. Dormer

    2006-01-01

    Superparamagnetic iron oxide nanoparticles (SNP) composed of magnetite (Fe3O4) were studied preliminarily as vehicles for therapeutic molecule delivery to the inner ear and as a middle ear implant capable of producing biomechanically relevant forces for auditory function. Magnetite SNP were synthesized, then encapsulated in either silica or poly (D,L,-Lactide-co-glycolide) or obtained commercially with coatings of oleic acid or dextran. Permanent

  20. Ear and kidney syndromes: Molecular versus clinical approach

    Microsoft Academic Search

    HASSANE IZZEDINE; FREDERIC TANKERE; VINCENT LAUNAY-VACHER; GILBERT DERAY

    2004-01-01

    Ear and kidney syndromes: Molecular versus clinical approach.The association between ear and kidney anomalies is not usually due to an insult to the embryo. In recent years, many essential development control genes that coordinate the assembly and function of kidney and ear have been discovered through the generation of animal mutants and have increased our understanding of the mechanisms of

  1. Understanding Inner Ear Development with Gene Expression Profiling

    E-print Network

    Corey, David P.

    Understanding Inner Ear Development with Gene Expression Profiling Zheng-Yi Chen,1,2 David P. Corey, Maryland 20815 ABSTRACT: Understanding the development of the inner ear requires knowing the spatial-tissue comparisons will identify genes unique to the inner ear, which will expe- dite the identification of new

  2. Ear growth, developmental stages and yield in winter wheat

    E-print Network

    Paris-Sud XI, Université de

    Ear growth, developmental stages and yield in winter wheat Jean-François LEDENT Volkmar STOY Helena in length (R,) of ear primordia was measured in collections of winter wheats (Triticum aestivum (L.) em or morphological characters. However, genotypes with faster growing ear primordia tended to have smaller cars

  3. A Survey on Ear Biometrics AYMAN ABAZA, WVHTC Foundation

    E-print Network

    Ross, Arun Abraham

    22 A Survey on Ear Biometrics AYMAN ABAZA, WVHTC Foundation ARUN ROSS, West Virginia University Recognizing people by their ear has recently received significant attention in the literature. Several reasons account for this trend: first, ear recognition does not suffer from some problems associated with other

  4. History of Studies on Mammalian Middle Ear Evolution: A

    E-print Network

    Sullivan, Jack

    History of Studies on Mammalian Middle Ear Evolution: A Comparative Morphological and Developmental for Developmental Biology, RIKEN, Kobe, Japan The mammalian middle ear represents one of the most fundamental middle ear was derived from elements of the jaw joint of nonmammalian amniotes. Fossils of mammalian

  5. Purdue extensionAspergillus Ear Rot Purdue extension

    E-print Network

    Holland, Jeffrey

    1 Purdue extensionAspergillus Ear Rot BP-83-W Purdue extension d i s e a s e s o f c o r n Aspergillus Ear Rot Authors: Charles Woloshuk Kiersten Wise www.btny.purdue.edu The fungus Aspergillus flavus causes Aspergillus ear rot, one of the most important diseases in corn. The fungus pro- duces a mycotoxin

  6. COCHLEAR IMPLANTATION IN PATIENTS WITH INNER EAR MALFORMATIONS

    Microsoft Academic Search

    M. H. Khalessi; M. Motesaddi Zarandi; P. Borghei; S. Abdi

    Performing cochlear implantation in patients with inner ear malformation has always been a matter of dispute. This study was designed to analyze the operative findings, complications, and post- operative performance of patients with inner ear anomalies who underwent cochlear implantation. Six patients with inner ear malformations underwent implantation in our academic tertiary referral center from 1997 to 2002. The average

  7. Performance analysis of the Ormia ochracea's coupled ears Murat Akcakayaa

    E-print Network

    Nehorai, Arye

    Performance analysis of the Ormia ochracea's coupled ears Murat Akcakayaa and Arye Nehoraib. This phenomenon has been explained by the mechanical coupling between the ears. In this paper, it is first shown that the coupling enhances the differences in times of arrival and frequency responses of the ears to the incoming

  8. Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells

    PubMed Central

    Qin, Ying; Naito, Yuji; Handa, Osamu; Hayashi, Natsuko; Kuki, Aiko; Mizushima, Katsura; Omatsu, Tatsushi; Tanimura, Yuko; Morita, Mayuko; Adachi, Satoko; Fukui, Akifumi; Hirata, Ikuhiro; Kishimoto, Etsuko; Nishikawa, Taichiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Yagi, Nobuaki; Kokura, Satoshi; Yoshikawa, Toshikazu

    2011-01-01

    Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic acid-induced small intestinal apoptosis, a hallmark of acetylsalicylic acid-induced enteropathy. PMID:22128216

  9. Heat shock protein 70-dependent protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells.

    PubMed

    Qin, Ying; Naito, Yuji; Handa, Osamu; Hayashi, Natsuko; Kuki, Aiko; Mizushima, Katsura; Omatsu, Tatsushi; Tanimura, Yuko; Morita, Mayuko; Adachi, Satoko; Fukui, Akifumi; Hirata, Ikuhiro; Kishimoto, Etsuko; Nishikawa, Taichiro; Uchiyama, Kazuhiko; Ishikawa, Takeshi; Takagi, Tomohisa; Yagi, Nobuaki; Kokura, Satoshi; Yoshikawa, Toshikazu

    2011-11-01

    Protection of the small intestine from mucosal injury induced by nonsteroidal anti-inflammatory drugs including acetylsalicylic acid is a critical issue in the field of gastroenterology. Polaprezinc an anti-ulcer drug, consisting of zinc and L-carnosine, provides gastric mucosal protection against various irritants. In this study, we investigated the protective effect of polaprezinc on acetylsalicylic acid-induced apoptosis of the RIE1 rat intestinal epithelial cell line. Confluent rat intestinal epithelial cells were incubated with 70 µM polaprezinc for 24 h, and then stimulated with or without 15 mM acetylsalicylic acid for a further 15 h. Subsequent cellular viability was quantified by fluorometric assay based on cell lysis and staining. Acetylsalicylic acid-induced cell death was also qualified by fluorescent microscopy of Hoechst33342 and propidium iodide. Heat shock proteins 70 protein expression after adding polaprezinc or acetylsalicylic acid was assessed by western blotting. To investigate the role of Heat shock protein 70, Heat shock protein 70-specific small interfering RNA was applied. Cell viability was quantified by fluorometric assay based on cell lysis and staining and apoptosis was analyzed by fluorescence-activated cell sorting. We found that acetylsalicylic acid significantly induced apoptosis of rat intestinal epithelial cells in a dose- and time-dependent manner. Polaprezinc significantly suppressed acetylsalicylic acid-induced apoptosis of rat intestinal epithelial cells at its late phase. At the same time, polaprezinc increased Heat shock protein 70 expressions of rat intestinal epithelial cells in a time-dependent manner. However, in Heat shock protein 70-silenced rat intestinal epithelial cells, polaprezinc could not suppress acetylsalicylic acid -induced apoptosis at its late phase. We conclude that polaprezinc-increased Heat shock protein 70 expression might be an important mechanism by which polaprezinc suppresses acetylsalicylic acid-induced small intestinal apoptosis, a hallmark of acetylsalicylic acid-induced enteropathy. PMID:22128216

  10. Bovine chromosomal regions affecting rheological traits in acid-induced skim milk gels.

    PubMed

    Glantz, M; Gustavsson, F; Bertelsen, H P; Stålhammar, H; Lindmark-Månsson, H; Paulsson, M; Bendixen, C; Gregersen, V R

    2015-02-01

    The production of fermented milk products has increased worldwide during the last decade and is expected to continue to increase during the coming decade. The quality of these products may be optimized through breeding practices; however, the relations between cow genetics and technological properties of acid milk gels are not fully known. Therefore, the aim of this study was to identify chromosomal regions affecting acid-induced coagulation properties and possible candidate genes. Skim milk samples from 377 Swedish Red cows were rheologically analyzed for acid-induced coagulation properties using low-amplitude oscillation measurements. The resulting traits, including gel strength, coagulation time, and yield stress, were used to conduct a genome-wide association study. Single nucleotide polymorphisms (SNP) were identified using the BovineHD SNPChip (Illumina Inc., San Diego, CA), resulting in almost 621,000 segregating markers. The genome was scanned for putative quantitative trait loci (QTL) regions, haplotypes based on highly associated SNP were inferred, and the additive genetic effects of haplotypes within each QTL region were analyzed using mixed models. A total of 8 genomic regions were identified, with large effects of the significant haplotype explaining between 4.8 and 9.8% of the phenotypic variance of the studied traits. One major QTL was identified to overlap between gel strength and yield stress, the QTL identified with the most significant SNP closest to the gene coding for ?-casein (CSN3). In addition, a chromosome-wide significant region affecting yield stress on BTA 11 was identified to be colocated with PAEP, coding for ?-lactoglobulin. Furthermore, the coagulation properties of the genetic variants within the 2 genes were compared with the coagulation properties identified by the patterns of the haplotypes within the regions, and it was discovered that the haplotypes were more diverse and in one case slightly better at explaining the phenotypic variance. Besides these significant QTL comprising the 2 milk proteins, 3 additional genes are proposed as possible candidates, namely RAB22A, CDH13, and STAT1, and all have previously been found to be expressed in the mammary gland. To our knowledge, this is the first attempt to map QTL regions for acid-induced coagulation properties. PMID:25529417

  11. Proteomic Investigation into Betulinic Acid-Induced Apoptosis of Human Cervical Cancer HeLa Cells

    PubMed Central

    Xu, Tao; Pang, Qiuying; Zhou, Dong; Zhang, Aiqin; Luo, Shaman; Wang, Yang; Yan, Xiufeng

    2014-01-01

    Betulinic acid is a pentacyclic triterpenoid that exhibits anticancer functions in human cancer cells. This study provides evidence that betulinic acid is highly effective against the human cervical cancer cell line HeLa by inducing dose- and time-dependent apoptosis. The apoptotic process was further investigated using a proteomics approach to reveal protein expression changes in HeLa cells following betulinic acid treatment. Proteomic analysis revealed that there were six up- and thirty down-regulated proteins in betulinic acid-induced HeLa cells, and these proteins were then subjected to functional pathway analysis using multiple analysis software. UDP-glucose 6-dehydrogenase, 6-phosphogluconate dehydrogenase decarboxylating, chain A Horf6-a novel human peroxidase enzyme that involved in redox process, was found to be down-regulated during the apoptosis process of the oxidative stress response pathway. Consistent with our results at the protein level, an increase in intracellular reactive oxygen species was observed in betulinic acid-treated cells. The proteins glucose-regulated protein and cargo-selection protein TIP47, which are involved in the endoplasmic reticulum pathway, were up-regulated by betulinic acid treatment. Meanwhile, 14-3-3 family proteins, including 14-3-3? and 14-3-3?, were down-regulated in response to betulinic acid treatment, which is consistent with the decrease in expression of the target genes 14-3-3? and 14-3-3?. Furthermore, it was found that the antiapoptotic bcl-2 gene was down-regulated while the proapoptotic bax gene was up-regulated after betulinic acid treatment in HeLa cells. These results suggest that betulinic acid induces apoptosis of HeLa cells by triggering both the endoplasmic reticulum pathway and the ROS-mediated mitochondrial pathway. PMID:25148076

  12. Bile Acids Induce Pancreatic Acinar Cell Injury and Pancreatitis by Activating Calcineurin*

    PubMed Central

    Muili, Kamaldeen A.; Wang, Dong; Orabi, Abrahim I.; Sarwar, Sheharyar; Luo, Yuhuan; Javed, Tanveer A.; Eisses, John F.; Mahmood, Syeda M.; Jin, Shunqian; Singh, Vijay P.; Ananthanaravanan, Meena; Perides, George; Williams, John A.; Molkentin, Jeffery D.; Husain, Sohail Z.

    2013-01-01

    Biliary pancreatitis is the leading cause of acute pancreatitis in both children and adults. A proposed mechanism is the reflux of bile into the pancreatic duct. Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca2+. Thus, it would be clinically relevant to know the targets of this aberrant Ca2+ signal. We hypothesized that the Ca2+-activated phosphatase calcineurin is such a Ca2+ target. To examine calcineurin activation, we infected primary acinar cells from mice with an adenovirus expressing the promoter for a downstream calcineurin effector, nuclear factor of activated T-cells (NFAT). The bile acid taurolithocholic acid-3-sulfate (TLCS) was primarily used to examine bile acid responses. TLCS caused calcineurin activation only at concentrations that cause acinar cell injury. The activation of calcineurin by TLCS was abolished by chelating intracellular Ca2+. Pretreatment with 1,2-bis(o-aminophenoxy)ethane-N,N,N?,N?-tetraacetic acid (acetoxymethyl ester) (BAPTA-AM) or the three specific calcineurin inhibitors FK506, cyclosporine A, or calcineurin inhibitory peptide prevented bile acid-induced acinar cell injury as measured by lactate dehydrogenase leakage and propidium iodide uptake. The calcineurin inhibitors reduced the intra-acinar activation of chymotrypsinogen within 30 min of TLCS administration, and they also prevented NF-?B activation. In vivo, mice that received FK506 or were deficient in the calcineurin isoform A? (CnA?) subunit had reduced pancreatitis severity after infusion of TLCS or taurocholic acid into the pancreatic duct. In summary, we demonstrate that acinar cell calcineurin is activated in response to Ca2+ generated by bile acid exposure, bile acid-induced pancreatic injury is dependent on calcineurin activation, and calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis. PMID:23148215

  13. Better-ear glimpsing in hearing-impaired listeners.

    PubMed

    Best, Virginia; Mason, Christine R; Kidd, Gerald; Iyer, Nandini; Brungart, Douglas S

    2015-02-01

    When competing speech sounds are spatially separated, listeners can make use of the ear with the better target-to-masker ratio. Recent studies showed that listeners with normal hearing are able to efficiently make use of this "better-ear," even when it alternates between left and right ears at different times in different frequency bands, which may contribute to the ability to listen in spatialized speech mixtures. In the present study, better-ear glimpsing in listeners with bilateral sensorineural hearing impairment, who perform poorly in spatialized speech mixtures, was investigated. The results suggest that this deficit is not related to better-ear glimpsing. PMID:25698053

  14. [Diseases of the middle ear in childhood].

    PubMed

    Minovi, A; Dazert, S

    2014-03-01

    Middle ear diseases in childhood play an important role in daily ENT practice due to their high incidence. Some of these like acute otitis media or otitis media with effusion have been studied extensively within the last decades. In this article, we present a selection of important childhood middle ear diseases and discuss the actual literature concerning their treatment, management of complications and outcome. Another main topic of this paper deals with the possibilities of surgical hearing rehabilitation in childhood. The bone-anchored hearing aid BAHA® and the active partially implantable device Vibrant Soundbridge® could successfully be applied for children. In this manuscript, we discuss the actual literature concerning clinical outcomes of -these implantable hearing aids. PMID:24710778

  15. Diseases of the middle ear in childhood.

    PubMed

    Minovi, Amir; Dazert, Stefan

    2014-01-01

    Middle ear diseases in childhood play an important role in daily ENT practice due to their high incidence. Some of these like acute otitis media or otitis media with effusion have been studied extensively within the last decades. In this article, we present a selection of important childhood middle ear diseases and discuss the actual literature concerning their treatment, management of complications and outcome. Another main topic of this paper deals with the possibilities of surgical hearing rehabilitation in childhood. The bone-anchored hearing aid BAHA(®) and the active partially implantable device Vibrant Soundbridge(®) could successfully be applied for children. In this manuscript, we discuss the actual literature concerning clinical outcomes of these implantable hearing aids. PMID:25587371

  16. Diseases of the middle ear in childhood

    PubMed Central

    Minovi, Amir; Dazert, Stefan

    2014-01-01

    Middle ear diseases in childhood play an important role in daily ENT practice due to their high incidence. Some of these like acute otitis media or otitis media with effusion have been studied extensively within the last decades. In this article, we present a selection of important childhood middle ear diseases and discuss the actual literature concerning their treatment, management of complications and outcome. Another main topic of this paper deals with the possibilities of surgical hearing rehabilitation in childhood. The bone-anchored hearing aid BAHA® and the active partially implantable device Vibrant Soundbridge® could successfully be applied for children. In this manuscript, we discuss the actual literature concerning clinical outcomes of these implantable hearing aids. PMID:25587371

  17. Ear tag induced Staphylococcus infection in mice.

    PubMed

    Cover, C E; Keenan, C M; Bettinger, G E

    1989-07-01

    Mice used in a 2-year oral toxicity study developed a progressive, moist dermatitis. The initial lesions were seen around the ears in which metal identification tags had been placed and usually progressed to include the skin of the neck and shoulder. Clinically, the mice were pruritic, lost weight, had rough coats, and became moribund. The predominant finding at necropsy was pale brown kidneys with irregular granular surfaces. Histologically, there was inflammation and focal-to-diffuse necrosis in the visceral organs and affected skin. The predominant organism isolated from the skin, kidneys and heart blood was Staphylococcus aureus. This bacterium is a common inhabitant of the skin of conventionally housed mice and its isolation from the kidneys and blood suggested that the portal of entry was the wound caused by the insertion of the metal ear tag. PMID:2761227

  18. Restriction of patching of bound concanavalin A after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts

    PubMed Central

    1979-01-01

    Topographical distribution of concanavalin A binding sites (CABS) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. Fatty acid composition was manipulated by incubating cells in fatty acid, ATP, CoA, and delipidated fetal calf serum (FCS). VLM cells grown in medium containing 5% FCS have a clustered CABS distribution. Plasma membrane vesicles (PMVs) derived from these cells have an arachidonate content of 1.7%. Elevation of PMV arachidonate to 15.8% results in a marked restriction of CABS patching, while elevation to 6.8% is associated with intermediate restriction of patching. Restriction of patching is associated with increased microviscosity. CABS of Rous sarcoma virus-transformed chicken embryo fibroblasts (RSV-CEF) are also responsive to arachidonate enrichment medium. Whereas untreated cells have a clustered CABS distribution, cells incubated for 24 h in arachidonate enrichment medium have predominantly a dispersed CABS distribution. In both VLM cells and RSV- CEF, ATP, CoA, and delipidated FCS alone have no effect upon CABS mobility. Inhibition of CABS patching is also observed when aspirin is included in the arachidonate enrichment medium but not when the cells are incubated in prostaglandins, thus suggesting that the restriction of CABS mobility is not mediated by prostaglandins. Other fatty acids (palmitate, oleate, nonadecanoate) failed to restrict CABS movement. The inhibition of CABS mobility is independent of cell shape change. PMID:229111

  19. Co-compartmentalization of MAP kinases and cytosolic phospholipase A2 at cytoplasmic arachidonate-rich lipid bodies.

    PubMed

    Yu, W; Bozza, P T; Tzizik, D M; Gray, J P; Cassara, J; Dvorak, A M; Weller, P F

    1998-03-01

    Lipid bodies are inducible lipid domains abundantly present in leukocytes engaged in inflammation. They are rich in esterified arachidonate and are also potential sites for eicosanoid-forming enzyme localization. It is therefore of interest to know whether arachidonate-releasing cytosolic phospholipase A2 (cPLA2) localizes at lipid bodies. Here, we present evidence that cPLA2 and its activating protein kinases, mitogen-activated protein (MAP) kinases, co-localize at lipid bodies. U937 cells express high levels of cPLA2 and contain numerous cytoplasmic lipid bodies. Using double-labeling immunocytochemistry we demonstrated punctate cytoplasmic localizations of both cPLA2 and MAP kinases in U937 cells that were perfectly concordant with fluorescent fatty-acid-labeled lipid bodies. The co-localization of cPLA2 and MAP kinases at lipid bodies was confirmed by subcellular fractionation and immunoblot. Lipid body fractions free of cytosol and other organelles contained significant amounts of [14C]arachidonate-labeled phosphatidylcholine and cPLA2 enzymatic activities. Immunoblotting with specific antibodies identified cPLA2 as well as MAP kinases, including ERK1, ERK2, p85, and p38, in lipid bodies. The co-compartmentalization within arachidonate-rich lipid bodies of cPLA2 and its potentially activating protein kinases suggests that lipid bodies may be structurally distinct intracellular sites active in extracellular ligand-induced arachidonate release and eicosanoid formation. PMID:9502418

  20. DIBROMOACETIC ACID-INDUCED ELEVATIONS OF ESTRADIOL IN THE CYCLING AND OVARIECTOMOZED/ESTRADIOL-IMPLANTED FEMALE RAT

    EPA Science Inventory

    Goldman, JM and Murr, AS. Dibromoacetic Acid-induced Elevations of Estradiol in Both Cycling and Ovariectomized / Estradiol-implanted Female Rats ABSTRACT Haloacetic acids are one of the principal classes of disinfection by-products generated by the chlorination of mun...

  1. F-Box Protein DOR Functions As a Novel Inhibitory Factor for Abscisic Acid-Induced Stomatal Closure

    E-print Network

    Deng, Xing-Wang

    F-Box Protein DOR Functions As a Novel Inhibitory Factor for Abscisic Acid-Induced Stomatal Closure drought stress, plants synthesize abscisic acid (ABA), which in turn induces a rapid closing of stoma- enous level of abscisic acid (ABA) increases and, through its complex signaling cascade, results in sto

  2. The aspirin metabolite sodium salicylate causes focal cerebral hemorrhage and cell death in rats with kainic acid-induced seizures

    Microsoft Academic Search

    J. Najbauer; E. M. Schuman; A. N. Mamelak

    2000-01-01

    Aspirin (acetylsalicylic acid), and its main metabolite sodium salicylate, have been shown to protect neurons from excitotoxic cell death in vitro. The objective of our study was to investigate the possible neuroprotective effects of sodium salicylate in vivo in rats with kainic acid-induced seizures, a model for temporal lobe epilepsy in human patients. Male Sprague–Dawley rats received intraperitoneal injections of

  3. Wide band bunny-ear radiating element

    Microsoft Academic Search

    J. J. Lee; S. Livingston

    1993-01-01

    A low-cost wideband radiating element for EW (electronic warfare) and radar array antenna applications is reported. This printed end-fire bunny-ear element is fed by a balanced slot line, and it can operate over 0.5 to 18 GHz with very low loss in an isolated environment. The input transition, the feed line, and the launching section of this element are essentially

  4. An investigation of ear necrosis in pigs

    PubMed Central

    Park, Jeonghwa; Friendship, Robert M.; Poljak, Zvonimir; DeLay, Josepha; Slavic, Durda; Dewey, Catherine E.

    2013-01-01

    Porcine ear necrosis was investigated in 23 conveniently chosen farms, consisting of 14 case farms and 9 control farms. Biopsies of lesions and oral swabs from pigs on 11 case farms were examined by histology and bacterial culture. All farms were visited for observations and a survey on management, housing, and the presence of other clinical signs or behavioral vices. Histological examination revealed that the lesions began on the surface and progressed to deeper layers, and that vascular damage did not appear to be the initiating cause. Spirochetes were only rarely observed in histological examination and were not cultured from biopsies and oral swabs. Staphylococcus aureus and Staphylococcus hyicus were cultured from 91% and 66% of samples, respectively. Ear biting and a humid environment were associated with ear necrosis. On some farms large numbers of pigs were affected and lesions were sometimes extensive. The condition appears to be an infectious disease beginning on the surface of the skin; contributing environmental and management factors are likely. PMID:24155434

  5. Ear Recognition from One Sample Per Person

    PubMed Central

    Chen, Long; Mu, Zhichun; Zhang, Baoqing; Zhang, Yi

    2015-01-01

    Biometrics has the advantages of efficiency and convenience in identity authentication. As one of the most promising biometric-based methods, ear recognition has received broad attention and research. Previous studies have achieved remarkable performance with multiple samples per person (MSPP) in the gallery. However, most conventional methods are insufficient when there is only one sample per person (OSPP) available in the gallery. To solve the OSPP problem by maximizing the use of a single sample, this paper proposes a hybrid multi-keypoint descriptor sparse representation-based classification (MKD-SRC) ear recognition approach based on 2D and 3D information. Because most 3D sensors capture 3D data accessorizing the corresponding 2D data, it is sensible to use both types of information. First, the ear region is extracted from the profile. Second, keypoints are detected and described for both the 2D texture image and 3D range image. Then, the hybrid MKD-SRC algorithm is used to complete the recognition with only OSPP in the gallery. Experimental results on a benchmark dataset have demonstrated the feasibility and effectiveness of the proposed method in resolving the OSPP problem. A Rank-one recognition rate of 96.4% is achieved for a gallery of 415 subjects, and the time involved in the computation is satisfactory compared to conventional methods. PMID:26024226

  6. Middle-ear velocity transfer function, cochlear input immittance, and middle-ear efficiency in chinchilla

    PubMed Central

    Ravicz, Michael E.; Rosowski, John J.

    2013-01-01

    The transfer function HV between stapes velocity VS and sound pressure near the tympanic membrane PTM is a descriptor of sound transmission through the middle ear (ME). The ME power transmission efficiency (MEE), the ratio of sound power entering the cochlea to power entering the middle ear, was computed from HV measured in seven chinchilla ears and previously reported measurements of ME input admittance YTM and ME pressure gain GMEP [Ravicz and Rosowski, J. Acoust. Soc. Am. 132, 2437–2454 (2012); J. Acoust. Soc. Am. 133, 2208–2223 (2013)] in the same ears. The ME was open, and a pressure sensor was inserted into the cochlear vestibule for most measurements. The cochlear input admittance YC computed from HV and GMEP is controlled by a combination of mass and resistance and is consistent with a minimum-phase system up to 27?kHz. The real part Re{YC}, which relates cochlear sound power to inner-ear sound pressure, decreased gradually with frequency up to 25 kHz and more rapidly above that. MEE was about 0.5 between 0.1 and 8?kHz, higher than previous estimates in this species, and decreased sharply at higher frequencies. PMID:24116422

  7. Arachidonic acid-dependent carbon-eight volatile synthesis from wounded liverwort (Marchantia polymorpha).

    PubMed

    Kihara, Hirotomo; Tanaka, Maya; Yamato, Katsuyuki T; Horibata, Akira; Yamada, Atsushi; Kita, Sayaka; Ishizaki, Kimitsune; Kajikawa, Masataka; Fukuzawa, Hideya; Kohchi, Takayuki; Akakabe, Yoshihiko; Matsui, Kenji

    2014-11-01

    Eight-carbon (C8) volatiles, such as 1-octen-3-ol, octan-3-one, and octan-3-ol, are ubiquitously found among fungi and bryophytes. In this study, it was found that the thalli of the common liverwort Marchantia polymorpha, a model plant species, emitted high amounts of C8 volatiles mainly consisting of (R)-1-octen-3-ol and octan-3-one upon mechanical wounding. The induction of emission took place within 40min. In intact thalli, 1-octen-3-yl acetate was the predominant C8 volatile while tissue disruption resulted in conversion of the acetate to 1-octen-3-ol. This conversion was carried out by an esterase showing stereospecificity to (R)-1-octen-3-yl acetate. From the transgenic line of M. polymorpha (des6(KO)) lacking arachidonic acid and eicosapentaenoic acid, formation of C8 volatiles was only minimally observed, which indicated that arachidonic and/or eicosapentaenoic acids were essential to form C8 volatiles in M. polymorpha. When des6(KO) thalli were exposed to the vapor of 1-octen-3-ol, they absorbed the alcohol and converted it into 1-octen-3-yl acetate and octan-3-one. Therefore, this implied that 1-octen-3-ol was the primary C8 product formed from arachidonic acid, and further metabolism involving acetylation and oxidoreduction occurred to diversify the C8 products. Octan-3-one was only minimally formed from completely disrupted thalli, while it was formed as the most abundant product in partially disrupted thalli. Therefore, it is assumed that the remaining intact tissues were involved in the conversion of 1-octen-3-ol to octan-3-one in the partially disrupted thalli. The conversion was partly promoted by addition of NAD(P)H into the completely disrupted tissues, suggesting an NAD(P)H-dependent oxidoreductase was involved in the conversion. PMID:25174554

  8. Proteolytic enzymes and arachidonic acid metabolites produced by MRC5 cells on various microcarrier substrates

    Microsoft Academic Search

    James Varani; Jefferey D. Hasday; Robert G. Sitrin; Pamela G. Brubaker; William A. hillegas

    1986-01-01

    Summary  Human diploid fibroblasts were cultured on microcarriers made from DEAE-dextran, denatured collagen, DEAE-dextran linked to\\u000a denatured collagen, and glass. Cells grown on these four substrates were examined for the production of proteolytic enzymes\\u000a and arachidonic acid metabolites. Culture fluids from cells grown on the DEAE-dextran microcarriers contained the highest\\u000a amounts of proteolytic enzyme activity. Both plasminogen-independent and plasminogen-dependent fibrinolytic activities

  9. Identification of arachidonic acid and its metabolism in Gulf of Mexico shrimp 

    E-print Network

    Lilly, Martha Lae

    1980-01-01

    results, the existence of a pathway for the conversion of linoleic acid to arachidonic acid via 18:3w6 and 20:3w6. An alternate pathway via 20:2w6 was demonstrated by Klenk and iMohrhauer (13), but it was later shown by Marcel (2) that the o iginal... Inte- gzator (Columbia Scientific Industries, Austin, TX) and an Addmaster Model 35 serial entry printer (Addmaster, San Gabriel, CA) . The weight per cent and retention times of the FANE were calculated on a Hewlett-Packard Desk Programmable...

  10. In vitro inhibition of arachidonic acid metabolism by two novel retinoid analogs

    Microsoft Academic Search

    C. Fiedler-Nagy; B. H. Wittreich; M. A. Carey

    1989-01-01

    Ro 23-6457, (all-E)-3,7-dimethyl-9-[2-(trifluoromethyl)-6-(nonyloxy) phenyl]-2,4,6,8-nonatetraenoic acid, and Ro 23-2895, (all-E)-9-[2-(nonyloxy)phenyl]-3,7-dimethyl-2,4,6,8-nonatetraenoic acid, are two novel retinoid analogs which exhibit antiinflammatory activity in both the developing and the established rat adjuvant arthritis models [8]. Here we investigated the effect of these two compounds on the production of arachidonic acid (AA) metabolites in twoin vitro test systems [i.e., Ca2+ ionophore A23187 (I)-stimulated resident rat

  11. Arachidonic acid metabolism in the human placenta: identification of a putative lipoxygenase.

    PubMed

    Jadoon, A; Cunningham, P; McDermott, L C

    2014-06-01

    Arachidonic acid (ARA) metabolites maintain pregnancy and control parturition. We generated a network of 77 proteins involved in placental ARA metabolism to identify novel proteins in this pathway. We identified a long pathway within this network which showed that secretory and cytosolic phospholipase A2 proteins act in concert. The functions of all network proteins expressed in the placental decidua were determined by database searches. Thus ARA metabolism was linked to carbohydrate metabolism. One protein, transmembrane protein 62 (TMEM62), expressed in decidua was previously uncharacterized, and was identified as a putative lipoxygenase. TMEM62 may play a role in pregnancy and/or parturition. PMID:24767823

  12. Retinal fatty acids of piglets fed docosahexaenoic and arachidonic acids from microbial sources

    Microsoft Academic Search

    Margaret C. Craig-Schmidt; Kathryn E. Stieh; Eric L. Lien

    1996-01-01

    Docosahexaenoic acid (DHA, 22?6n-3) and arachidonic acid (AA, 20?4n-6) serve important roles in perinatal visual and neural\\u000a development. A neonatal pig model was used to determine if dietary supplementation with DHA and AA at slightly greater concentrations\\u000a than normally found in human milk would influence fatty acid accretion in retina. One-day-old piglets were assigned to one\\u000a of four diets (n=5\\/group):

  13. Transformation of arachidonic acid to 19-hydroxy- and 20-hydroxy-eicosatetraenoic acids using Candida bombicola

    Microsoft Academic Search

    Asmita Prabhune; Simon R. Fox; Colin Ratledge

    2002-01-01

    Candida bombicola (ATCC 22214) and C. apicola (ATCC 96134), grown on glucose (100 g l-1) and arachidonic acid (5Z, 8Z, 11Z, 14Z-eicosatetraenoic acid; AA), 1.25 g l-1, synthesized sophorolipid up to 0.93 g l-1. Acid hydrolysis of sophorolipid yielded 19-hydroxy-5Z, 8Z, 11Z, 14Z-eicosatetraenoic acid (19-HETE) and 20-hydroxy-5Z, 8Z, 11Z, 14Z-eicosatetraenoic acid (20-HETE) which were identified by TLC and GC-MS; the

  14. Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred

    2010-02-01

    The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.

  15. Synthesis of site-specifically deuterated arachidonic acid derivatives containing a remote tritium radiolabel

    PubMed Central

    McGinley, Chris M.; van der Donk, Wilfred A.

    2010-01-01

    Summary The synthesis of arachidonic acid derivatives containing site-specifically incorporated deuterium atoms and also a remote tritium label are described. Deuterium incorporation at the C11 and/or C15 position was achieved using Wittig chemistry, while the radiolabel was introduced at a remote position using [3H]NaBH4 as the radiolabel source. These compounds can be used to measure secondary kinetic isotope effects for both cyclooxygenase and lipoxygenase enzymes under aerobic turnover with high precision. PMID:20414469

  16. Identification of a novel type of polyunsaturated fatty acid synthase involved in arachidonic acid biosynthesis.

    PubMed

    Ujihara, Tetsuro; Nagano, Megumi; Wada, Hajime; Mitsuhashi, Satoshi

    2014-11-01

    Arachidonic acid (ARA) is a polyunsaturated fatty acid (PUFA) and an essential component of membrane lipids. However, the PUFA synthase required for ARA biosynthesis has not been identified in any organism. To identify the PUFA synthase producing ARA, we determined the draft genome sequence of the marine bacterium Aureispira marina, which produces a high level of ARA, and found a gene cluster encoding a putative PUFA synthase for ARA production. Expression of the gene cluster in Escherichia coli induced production of ARA, demonstrating that the gene cluster encodes a PUFA synthase required for ARA biosynthesis. PMID:25263707

  17. Carnosic Acid Induces Apoptosis Through Reactive Oxygen Species-mediated Endoplasmic Reticulum Stress Induction in Human Renal Carcinoma Caki Cells

    PubMed Central

    Min, Kyoung-jin; Jung, Kyong-Jin; Kwon, Taeg Kyu

    2014-01-01

    Background: Carnosic acid, which is one of extract components of rosemary, has anti-inflammatory, anti-oxidant, and anti-cancer effects. However, the anti-cancer effect of carnosic acid in human renal carcinoma cells is unknown. Methods: Flow cytometry analysis was used to examine the effects of carnosic acid on apoptosis, and Asp-Glu-Val-Asp-ase activity assay kit was used to investigate the involvement of caspase activation. To determine protein expression of apoptotic and endoplasmic reticulum (ER) stress-related proteins, we used Western blotting. Intracellular accumulation of reactive oxygen species (ROS) was determined using the fluorescent probes 2’, 7’-dichlorodihydrofluorescein diacetate (H2DCFDA). Results: Carnosic acid induced sub-diploid DNA content, sub-G1, population and poly (ADP-ribose) polymerase (PARP) cleavage and activated caspase-3. A pan-caspase inhibitor, a benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone, markedly reduced apoptosis in carnosic acid-treated cells. Carnosic acid promoted intracellular ROS production, and pretreatment with the ROS scavengers (N-acetyl-L-cysteine and glutathione ethyl ester) inhibited carnosic acid-induced apoptosis. Furthermore, carnosic acid also induced expression of ER stress marker proteins, including activating transcription factor 4 (ATF4) and CCAAT/enhancer-binding protein-homologous protein (CHOP), in a dose- and time-dependent manner. Down-regulation of ATF4 and CHOP by small interfering RNA (siRNA) markedly reduced carnosic acid-induced sub-G1 population and PARP cleavage. In addition, carnosic acid induced apoptosis in human breast carcinoma MDA-MB-361 and human hepatocellular carcinoma SK-HEP1 cells, but not in normal human skin fibroblast cells and normal mouse kidney epithelial TMCK-1 cells. Conclusion: Carnosic acid induced apoptosis through production of ROS and induction of ER stress in human renal carcinoma Caki cells. PMID:25337586

  18. Epoxyeicosatrienoic acids induce growth inhibition and calpain\\/caspase-12 dependent apoptosis in PDGF cultured 3T6 fibroblast

    Microsoft Academic Search

    Diana Nieves; Juan J. Moreno

    2007-01-01

    Previous studies have demonstrated that arachidonic acid (AA) metabolites released by the cyclooxygenase pathway is involved\\u000a in serum-induced 3T6 fibroblast cycle progression and proliferation. However, these results also suggest that other AA cascade\\u000a pathways might be involved. Recently, we also described the role of hydroxyeicosatetraenoic acids, which are produced by cytochrome\\u000a P450 monooxygenases (CYP), in 3T6 fibroblast growth. AA can

  19. Effects of ear-canal pressurization on middle-ear bone- and air-conduction responses

    PubMed Central

    Homma, Kenji; Shimizu, Yoshitaka; Kim, Namkeun; Du, Yu; Puria, Sunil

    2014-01-01

    In extremely loud noise environments, it is important to not only protect one’s hearing against noise transmitted through the air-conduction (AC) pathway, but also through the bone-conduction (BC) pathways. Much of the energy transmitted through the BC pathways is concentrated in the mid-frequency range around 1.5–2 kHz, which is likely due to the structural resonance of the middle ear. One potential approach for mitigating this mid-frequency BC noise transmission is to introduce a positive or negative static pressure in the ear canal, which is known to reduce BC as well as AC hearing sensitivity. In the present study, middle-ear ossicular velocities at the umbo and stapes were measured using human cadaver temporal bones in response to both BC and AC excitations, while static air pressures of ±400 mm H2O were applied in the ear canal. For the maximum negative pressure of ?400 mm H2O, mean BC stapes-velocity reductions of about 5–8 dB were observed in the frequency range from 0.8 to 2.5 kHz, with a peak reduction of 8.6(± 4.7) dB at 1.6 kHz. Finite-element analysis indicates that the peak BC-response reduction tends to be in the mid-frequency range because the middle-ear BC resonance, which is typically around 1.5–2 kHz, is suppressed by the pressure-induced stiffening of the middle-ear structure. The measured data also show that the BC responses are reduced more for negative static pressures than for positive static pressures. This may be attributable to a difference in the distribution of the stiffening among the middle-ear components depending on the polarity of the static pressure. The characteristics of the BC-response reductions are found to be largely consistent with the available psychoacoustic data, and are therefore indicative of the relative importance of the middle-ear mechanism in BC hearing. PMID:19944139

  20. Increase of [Ca 2+]i and release of arachidonic acid via activation of M2 receptor coupled to Gi and Rho proteins in oesophageal muscle

    Microsoft Academic Search

    Uy Dong Sohn; Yong Woo Hong; Hyoung Chul Choi; Jeoung Hee Ha; Kwang Youn Lee; Won Joon Kim; Piero Biancani; Ji Hoon Jeong; In Hoi Huh

    2000-01-01

    We have previously shown that acetylcholine-induced contraction of oesophageal circular muscle depends on activation of phosphatidylcholine selective phospholipase C and D, which result in formation of diacylglycerol, and of phospholipase 2 which produces arachidonic acid. Diacylglycerol and arachidonic acid interact synergistically to activate protein kinase C. We have therefore investigated the relationship between cytosolic Ca2+ and activation of phospholipase A2

  1. Expression of phospholipases A2 in primary human lung macrophages Role of cytosolic phospholipase A2-in arachidonic acid release and platelet

    E-print Network

    Gelb, Michael

    2- in arachidonic acid release and platelet activating factor synthesis Giorgio Giannattasio: Arachidonic acid Platelet activating factor Phospholipase A2 Lung macrophage Eicosanoid Inflammation). These inhibitors also reduce by 70% the synthesis of platelet-activating factor by activated macrophages. Among

  2. Effect of inhibitors of proteolysis and arachidonic acid metabolism on burn-induced protein breakdown.

    PubMed

    Odessey, R

    1985-07-01

    A rat model has been developed to study the local effects of burn injury on the underlying muscle tissue. Protein turnover was measured in soleus muscle incubated in vitro in which both tyrosine release and protein synthesis was measured. A scald injury (3 seconds) to a small area of one hindlimb produces an increase in muscle proteolysis and is without effect on the soleus muscle of the contralateral leg. A very high concentration of indomethacin (40 mumol/L) had no effect on proteolysis in the control muscle but specifically inhibited burn-induced protein breakdown. However, since other cyclooxygenase inhibitors (aspirin and ibuprofen), lipoxygenase inhibitors (ETYA, NDGA, and esculetin), and mepacrine (a phospholipase inhibitor) had no effect on protein breakdown, it is unlikely that a product of arachidonic acid metabolism maintains the increased proteolysis in vitro. In addition, endogenous production of prostaglandin E2 (PGE2) was not different in muscles from burned and control legs. Probes of the proteolytic pathway using inhibitors show that the burn-induced stimulation of proteolysis is consistent with the stimulation of lysosomal protease activity. These results are supported by the observation of increased acid protease activity in muscle homogenates from the burned leg. The best hypothesis that explains these data is that a lysosomal pathway of protein degradation may be enhanced by burn. Products of arachidonic acid metabolism do not appear to maintain burn-induced proteolysis in muscle, although their role in initiating the pathological changes in vivo cannot be excluded. PMID:3925289

  3. Endogenous biosynthesis of arachidonic acid epoxides in humans: Increased formation in pregnancy-induced hypertension

    SciTech Connect

    Catella, F.; Lawson, J.A.; Fitzgerald, D.J.; FitzGerald, G.A. (Vanderbilt Univ., Nashville, TN (USA))

    1990-08-01

    Arachidonic acid is metabolized by means of P450 isoenzyme(s) to form epoxyeicosatrienoic acids (EETs) and their corresponding dihydroxy derivatives (DHETs). In the present study, we established the presence in human urine of 8,9-, 11,12-, and 14,15-EETs and their corresponding DHETs by developing quantitative assays and using negative ion, chemical ionization GC/MS and octadeuterated internal standards. Urinary excretion of 8,9- and 11,12-DHET increased in healthy pregnant women compared with nonpregnant female volunteers. By contrast, excretion of 11,12-DHET and 14,15-DHET, but not the 8,9-DHET regioisomer, increased even further in patients with pregnancy-induced hypertension. Intravenous administration of (3H)14,15-EET to three dogs markedly increased its DHET in plasma. The terminal half-life ranged from 7.9-12.3 min and the volume of distribution (3.5-5.3 liters) suggested limited distribution outside the plasma compartment. Negligible radioactivity was detected in urine; this fact infers that under physiological circumstances, urinary DHETs largely derive from the kidney. That P450 metabolites of arachidonic acid are formed in humans supports the hypothesis that these metabolites contribute to the physiological response to normal pregnancy and the pathophysiology of pregnancy-induced hypertension.

  4. Some secondary plant metabolites in Desmodium adscendens and their effects on arachidonic acid metabolism.

    PubMed

    Addy, M E

    1992-09-01

    The effects of three chemically different groups of compounds, (triterpenoid saponins, beta-phenylethylamines and tetrahydroisoquinolines), known to be present in Desmodium adscendens, on plasma membrane ion channel, cytochrome P450 NADPH-dependent oxygenation of arachidonic acid, and production of prostaglandins by the cyclooxygenase enzyme system, are described. The very high-conductance calcium-activated potassium ion channel, which is responsible for the maintenance of tone in smooth muscles, was activated by the saponins. The cytochrome P450 NADPH-dependent monooxygenase reaction, which produces epoxy- and hydroxylated eicosanoids from arachidonic acid metabolism, was inhibited by an analogue of the tetrahydroisoquinoline present in the plant. This analogue also acted as a reductant in the prostaglandin synthesizing system using microsomes from ram seminal vesicles. The same system was activated by the beta-phenylethylamines found in the plant material, with the formation of more prostaglandins, the type being dependent on the amount of cyclooxygenase enzyme used and the presence or absence of coenzyme. PMID:1438471

  5. Kinetics of uptake and distribution of arachidonic acid by rat alveolar macrophages

    SciTech Connect

    Robison, T.W.; Duncan, D.P.; Forman, H.J.

    1988-10-01

    The time course of uptake and distribution of /sup 3/H-arachidonic acid (/sup 3/H-AA) into rat alveolar macrophage phospholipid pools was examined. Macrophages incubated with exogenous /sup 3/H-AA in RPMI-1640 containing 0.1% bovine serum albumin (BSA), incorporated this radiolabel into phosphatidylcholine and phosphatidylinositol (PI) with plateaus reached within 2 to 4 hours, which remained relatively constant for up to 18 hours. Incorporation of /sup 3/H-AA into phosphatidylethanolamine was small, but continued to increase for 14 hours. Analysis of phosphate content in phospholipid pools revealed that treatment with exogenous 5 nM arachidonic acid had no effect upon pool sizes, but there was a selective incorporation of /sup 3/H-AA into PI. Cells were incubated with /sup 3/H-AA in RPMI alone or medium containing either 0.2% lactalbumin, fetal calf serum at variable concentrations, 10% Nu Serum, or 0.1% BSA. Incubation of macrophages with /sup 3/H-AA in RPMI alone or containing 0.2% lactalbumin, resulted in approximately 70% of the radiolabel taken up by the cells being incorporated into triglyceride. The addition of BSA to RPMI-1640 medium was found to facilitate selective uptake of /sup 3/H-AA into phospholipids. Approximately 70% of incorporated /sup 3/H-AA was releasable through the action of exogenous phospholipase A2.

  6. Microsurgical replantation of a partial ear, with leech therapy.

    PubMed

    Cho, B H; Ahn, H B

    1999-10-01

    Ear reconstruction is very difficult to perform and often results in a devastating deformity. The use of microsurgical replantation techniques has allowed very favorable aesthetic results. The authors report a case of partial ear replantation without venous repair with the use of medicinal leeches to decompress the acute venous congestion that occurred during postoperative care. Medicinal leech therapy can be very useful in partial ear replantation in cases with no venous repair. PMID:10517472

  7. The middle ear mass: a rare but important diagnosis

    PubMed Central

    Pankhania, Miran; Rourke, Thomas; Draper, Mark R

    2011-01-01

    The authors report a rare case of primary intracranial meningioma presenting as a middle ear mass with conductive hearing loss. The authors aim to highlight the importance of diagnosing a middle ear mass, which although rare, may have a substantial impact on ongoing patient management. A discussion of other middle ear pathologies is made in order to demonstrate the subtle differences in presentation. PMID:22669530

  8. Image of the ear auricle in brain scintigrams

    Microsoft Academic Search

    Dag M. Solheim; Jens O. Andersen

    1977-01-01

    In a prospective study covering a 2-year period, the ear auricle was distinctly imaged in lateral 99mTc-pertechnetate brain scintiphotos\\/scintiscans in 25 of 2500 patients submitted to routine brain scintigraphy. In 6 patients with initially unremarkable scintiphotos, ear rubbing resulted in scintigraphic ear imaging in the lateral projection, indicating auricular hyperemia as a significant cause of the phenomenon. The evaluation of

  9. On hearing with more than one ear: lessons from evolution

    PubMed Central

    Schnupp, Jan W H; Carr, Catherine E

    2011-01-01

    Although ears capable of detecting airborne sound have arisen repeatedly and independently in different species, most animals that are capable of hearing have a pair of ears. We review the advantages that arise from having two ears and discuss recent research on the similarities and differences in the binaural processing strategies adopted by birds and mammals. We also ask how these different adaptations for binaural and spatial hearing might inform and inspire the development of techniques for future auditory prosthetic devices. PMID:19471267

  10. Palmitoleic acid induces the cardiac mitochondrial membrane permeability transition despite the presence of l-carnitine.

    PubMed

    Oyanagi, Eri; Uchida, Masataka; Miyakawa, Takeshi; Miyachi, Motohiko; Yamaguchi, Hidetaka; Nagami, Kuniatsu; Utsumi, Kozo; Yano, Hiromi

    2015-07-17

    Although palmitoleic acid (C16:1) is associated with arrhythmias, and increases in an age-dependent matter, the effects of l-carnitine, which is essential for the transport of long-chain fatty acids into the mitochondria, are unclear. It has been postulated that l-carnitine may attenuate palmitate (C16:0)-induced mitochondrial dysfunction and the apoptosis of cardiomyocytes. The aim of this study was to elucidate the activity of l-carnitine in the prevention of the palmitoleic acid-induced mitochondrial membrane permeability transition and cytochrome c release using isolated cardiac mitochondria from rats. Palmitoleoyl-CoA-induced mitochondrial respiration was not accelerated by l-carnitine treatment, and this respiration was slightly inhibited by oligomycin, which is an inhibitor of ATP synthase. Despite pretreatment with l-carnitine, the mitochondrial membrane potential decreased and mitochondrial swelling was induced by palmitoleoyl-CoA. In the presence of a combination of l-carnitine and tiron, a free radical scavenger, there was attenuated mitochondrial swelling and cytochrome c release following palmitoleoyl-CoA treatment. We concluded that palmitoleic acid, but not palmitate, induces the cardiac mitochondrial membrane permeability transition despite the presence of l-carnitine. PMID:25983324

  11. Ulcer healing activity of Mumijo aqueous extract against acetic acid induced gastric ulcer in rats

    PubMed Central

    Shahrokhi, Nader; Keshavarzi, Zakieh; Khaksari, Mohammad

    2015-01-01

    Objective: Gastric ulcer is an important clinical problem, chiefly due to extensive use of some drugs. The aim was to assess the activity of Mumijo extract (which is used in traditional medicine) against acetic acid induced gastric ulcer in rats. Materials and Methods: The aqueous extract of Mumijo was prepared. Animals were randomly (n = 10) divided into four groups: Control, sham-operated group (received 0.2 ml of acetic acid to induce gastric ulcer), Mumijo (100 mg/kg/daily) were given for 4 days postacetic acid administration, and ranitidine group (20 mg/kg). The assessed parameters were pH and pepsin levels (by Anson method) of gastric contents and gastric histopathology. Ranitidine was used as reference anti-ulcer drug. Results: The extract (100 mg/kg/daily, p.o.) inhibited acid acetic-induced gastric ulceration by elevating its pH versus sham group (P < 0.01) and decreasing the pepsin levels compared to standard drug, ranitidine (P < 0.05). The histopathology data showed that the treatment with Mumijo extract had a significant protection against all mucosal damages. Conclusion: Mumijo extract has potent antiulcer activity. Its anti-ulcer property probably acts via a reduction in gastric acid secretion and pepsin levels. The obtained results support the use of this herbal material in folk medicine. PMID:25709338

  12. Acid-induced gelation behavior of casein/whey protein solutions assessed by oscillatory rheology.

    PubMed

    Sadeghi, Mahboubeh; Madadlou, Ashkan; Khosrowshahi, Asghar; Mohammadifar, Mohammadamin

    2014-09-01

    Gelation process of acid-induced casein gels was studied using response surface method (RSM). Ratio of casein to whey proteins, incubation and heating temperatures were independent variables. Final storage modulus (G') measured 200 min after the addition of glucono-?-lactone and the gelation time i.e. the time at which G' of gels became greater than 1 Pa were the parameters studied. Incubation temperature strongly affected both parameters. The higher the incubation temperature, the lower was the G' and the shorter the gelation time. Increased heating temperature however, increased the G' but again shortened the gelation time. Increase in G' was attributed to the formation of disulphide cross-linkages between denatured whey proteins and casein chains; whilst the latter was legitimized by considering the higher isoelectric pH of whey proteins. Maximum response (G'?=?268.93 Pa) was obtained at 2.7 % w/w, 25 °C and 90 °C for casein content, incubation and heating temperatures, respectively. PMID:25190871

  13. Catalase Overexpression Reduces Lactic Acid-Induced Oxidative Stress in Saccharomyces cerevisiae?

    PubMed Central

    Abbott, Derek A.; Suir, Erwin; Duong, Giang-Huong; de Hulster, Erik; Pronk, Jack T.; van Maris, Antonius J. A.

    2009-01-01

    Industrial production of lactic acid with the current pyruvate decarboxylase-negative Saccharomyces cerevisiae strains requires aeration to allow for respiratory generation of ATP to facilitate growth and, even under nongrowing conditions, cellular maintenance. In the current study, we observed an inhibition of aerobic growth in the presence of lactic acid. Unexpectedly, the cyb2? reference strain, used to avoid aerobic consumption of lactic acid, had a specific growth rate of 0.25 h?1 in anaerobic batch cultures containing lactic acid but only 0.16 h?1 in identical aerobic cultures. Measurements of aerobic cultures of S. cerevisiae showed that the addition of lactic acid to the growth medium resulted in elevated levels of reactive oxygen species (ROS). To reduce the accumulation of lactic acid-induced ROS, cytosolic catalase (CTT1) was overexpressed by replacing the native promoter with the strong constitutive TPI1 promoter. Increased activity of catalase was confirmed and later correlated with decreased levels of ROS and increased specific growth rates in the presence of high lactic acid concentrations. The increased fitness of this genetically modified strain demonstrates the successful attenuation of additional stress that is derived from aerobic metabolism and may provide the basis for enhanced (micro)aerobic production of organic acids in S. cerevisiae. PMID:19251894

  14. Butyric acid-induced apoptosis of murine thymocytes, splenic T cells, and human Jurkat T cells.

    PubMed Central

    Kurita-Ochiai, T; Fukushima, K; Ochiai, K

    1997-01-01

    The purpose of this study was to examine the effect of butyric acid, an extracellular metabolite from periodontopathic bacteria, on apoptosis induction in murine thymocytes, splenic T cells, and human Jurkat T cells. Butyric acid significantly suppressed T-cell viability in both a concentration- and time-dependent fashion. The results of DNA fragmentation assay indicated that butyric acid rapidly induced apoptosis in thymocytes (with 1.25 mM butyric acid and 6 h after treatment) and in splenic T cells and Jurkat cells (with 2.5 mM butyric acid and 16 h after treatment). Incubation of thymocytes or Jurkat cells with 5 mM butyric acid for 21 h resulted in the typical ladder pattern of DNA fragmentation. Furthermore, Jurkat cells treated with 5 mM butyric acid showed the characteristic pattern of apoptotic cells such as chromatin condensation and hypodiploid nuclei. Experiments with fractionated subpopulations of splenic T cells revealed that DNA fragmentation was predominantly observed in CD4+ T cells. Butyric acid-induced apoptosis of thymocytes was decreased by the protein kinase inhibitors H7 and staurosporine. These inhibitors were less effective with similarly treated splenic T cells and Jurkat cells. These data suggest that butyric acid, one of the volatile fatty acids produced by periodontopathic bacteria and one that easily penetrates the oral mucosa, can modulate the immunoregulatory cell population in periodontal tissue by inducing T-cell death through apoptosis. PMID:8975889

  15. Effects of ionizing radiation on retinoic acid-inducible gene-I-like receptors

    PubMed Central

    YOSHINO, HIRONORI; SAITOH, TAKAHIRO; KOZAKAI, MASATAKA; KASHIWAKURA, IKUO

    2015-01-01

    Retinoic acid-inducible gene-I (RIG-I)-like receptors [RLRs; RIG-I and melanoma differentiation-associated gene 5 (MDA5)] sense virus-derived RNA or a synthetic analog of double-stranded RNA polyinosinic-polycytidylic acid [poly(I:C)] and are responsible for host defense against viruses. However, it remains unclear whether radiation affects RLRs. Therefore, the present study investigated the effects of ionizing radiation on RIG-I and MDA5 expression and the response to poly(I:C) using THP1 (human monocytic cell line)-derived macrophages. Non- and X-irradiated (1–10 Gy) macrophages expressed RIG-I and MDA5 at mRNA and protein levels and there was no significant difference in the expression levels. Non- and X-irradiated macrophages expressed antiviral cytokine interferon (IFN)-? mRNA following poly(I:C)-low molecular weight/LyoVec™ and poly(I:C)-high molecular weight/LyoVec™ stimulation, the agonist of RIG-I and MDA5, respectively. In line with the results of the expression of RIG-I and MDA5, no significant difference in the expression of IFN-? mRNA was observed between non- and X-irradiation. These results indicate that ionizing radiation hardly affects RLR expression and the response to their agonist poly(I:C) in THP1-derived macrophages. PMID:25469248

  16. Effects of ionizing radiation on retinoic acid-inducible gene-I-like receptors.

    PubMed

    Yoshino, Hironori; Saitoh, Takahiro; Kozakai, Masataka; Kashiwakura, Ikuo

    2015-01-01

    Retinoic acid-inducible gene-I (RIG-I)-like receptors [RLRs; RIG-I and melanoma differentiation-associated gene 5 (MDA5)] sense virus-derived RNA or a synthetic analog of double-stranded RNA polyinosinic-polycytidylic acid [poly(I:C)] and are responsible for host defense against viruses. However, it remains unclear whether radiation affects RLRs. Therefore, the present study investigated the effects of ionizing radiation on RIG-I and MDA5 expression and the response to poly(I:C) using THP1 (human monocytic cell line)-derived macrophages. Non- and X-irradiated (1-10 Gy) macrophages expressed RIG-I and MDA5 at mRNA and protein levels and there was no significant difference in the expression levels. Non- and X-irradiated macrophages expressed antiviral cytokine interferon (IFN)-? mRNA following poly(I:C)-low molecular weight/LyoVec™ and poly(I:C)-high molecular weight/LyoVec™ stimulation, the agonist of RIG-I and MDA5, respectively. In line with the results of the expression of RIG-I and MDA5, no significant difference in the expression of IFN-? mRNA was observed between non- and X-irradiation. These results indicate that ionizing radiation hardly affects RLR expression and the response to their agonist poly(I:C) in THP1-derived macrophages. PMID:25469248

  17. Retinoic acid induced-1 (Rai1) regulates craniofacial and brain development in Xenopus.

    PubMed

    Tahir, Raiha; Kennedy, Allyson; Elsea, Sarah H; Dickinson, Amanda J

    2014-08-01

    Retinoic acid induced-1 (RAI1) is an important yet understudied histone code reader that when mutated in humans results in Smith-Magenis syndrome (SMS), a neurobehavioral disorder accompanied by signature craniofacial abnormalities. Despite previous studies in mouse and human cell models, very little is known about the function of RAI1 during embryonic development. In the present study, we have turned to the model vertebrates Xenopus laevis and Xenopus tropicalis to better understand the developmental roles of Rai1. First we demonstrate that the Rai1 protein sequence is conserved in frogs, especially in known functional domains. By in situ hybridization we revealed expression of rai1 in the developing craniofacial tissues and the nervous system. Knockdown of Rai1 using antisense morpholinos resulted in defects in the developing brain and face. In particular, Rai1 morphants display midface hypoplasia and malformed mouth shape analogous to defects in humans with SMS. These craniofacial defects were accompanied with aberrant neural crest migration and reduction in the size of facial cartilage elements. Rai1 morphants also had defects in axon patterns and decreased forebrain ventricle size. Such brain defects correlated with a decrease in the neurotrophic factor, bdnf, and increased forebrain apoptosis. Our results emphasize a critical role of Rai1 for normal neural and craniofacial development, and further the current understanding of potential mechanisms that cause SMS. PMID:24878353

  18. Phosphatidate Phosphatase Activity Plays Key Role in Protection against Fatty Acid-induced Toxicity in Yeast*

    PubMed Central

    Fakas, Stylianos; Qiu, Yixuan; Dixon, Joseph L.; Han, Gil-Soo; Ruggles, Kelly V.; Garbarino, Jeanne; Sturley, Stephen L.; Carman, George M.

    2011-01-01

    The PAH1-encoded phosphatidate (PA) phosphatase in Saccharomyces cerevisiae is a pivotal enzyme that produces diacylglycerol for the synthesis of triacylglycerol (TAG) and simultaneously controls the level of PA used for phospholipid synthesis. Quantitative lipid analysis showed that the pah1? mutation caused a reduction in TAG mass and an elevation in the mass of phospholipids and free fatty acids, changes that were more pronounced in the stationary phase. The levels of unsaturated fatty acids in the pah1? mutant were unaltered, although the ratio of palmitoleic acid to oleic acid was increased with a similar change in the fatty acid composition of phospholipids. The pah1? mutant exhibited classic hallmarks of apoptosis in stationary phase and a marked reduction in the quantity of cytoplasmic lipid droplets. Cells lacking PA phosphatase were sensitive to exogenous fatty acids in the order of toxicity palmitoleic acid > oleic acid > palmitic acid. In contrast, the growth of wild type cells was not inhibited by fatty acid supplementation. In addition, wild type cells supplemented with palmitoleic acid exhibited an induction in PA phosphatase activity and an increase in TAG synthesis. Deletion of the DGK1-encoded diacylglycerol kinase, which counteracts PA phosphatase in controlling PA content, suppressed the defect in lipid droplet formation in the pah1? mutant. However, the sensitivity of the pah1? mutant to palmitoleic acid was not rescued by the dgk1? mutation. Overall, these findings indicate a key role of PA phosphatase in TAG synthesis for protection against fatty acid-induced toxicity. PMID:21708942

  19. Computed Tomography Staging of Middle Ear Cholesteatoma

    PubMed Central

    Razek, Ahmed Abdel Khalek Abdel; Ghonim, Mohamed Rashad; Ashraf, Bassem

    2015-01-01

    Summary Background To establish computed tomography (CT) staging of middle ear cholesteatoma and assess its impact on the selection of the surgical procedure. Material/Methods Prospective study was conducted on 61 consecutive patients (mean age 26.8 years) with middle ear cholesteatoma. CT scan of the temporal bone and surgery were performed in all patients. CT staging classified cholesteatoma according to its location in the tympanic cavity (T); extension into the mastoid (M); and associated complications (C). Cholesteatoma was staged as stage I (T1, T2), stage II (T3, M1, M2, C1), and stage III (C2). Results The overall sensitivity of CT staging of cholesteatoma compared to surgery was 88% with excellent agreement and correlation between CT findings and intra-operative findings (K=0.863, r=0.86, P=0.001). There was excellent agreement and correlation of CT staging with surgical findings for T location (K=0.811, r=0.89, P=0.001), good for M extension (K=0.734, r=0.88, P=0.001), and excellent for associated C complications (K=1.00, r=1.0, P=0.001). Atticotympanotomy was carried out in stage I (n=14), intact canal wall surgery was performed in stage II (n=38), and canal wall down surgery was done in stage III (n=5) and stage II (n=4). Conclusions We established CT staging of middle ear cholesteatoma that helps surgeons to select an appropriate surgery.

  20. Immunosuppressive therapy for autoimmune inner ear disease

    PubMed Central

    Buniel, Maria C; Geelan-Hansen, Katie; Weber, Peter C

    2009-01-01

    Autoimmune inner ear disease (AIED) is a rare disease that is diagnosed after clinical suspicion and response to corticosteroids. AIED manifests as progressive, bilateral, although often asynchronous, sensorineural hearing loss and can be associated with vestibular symptoms. Since its description as a defined disease entity in 1979, the initial mainstay of treatment remains high-dose corticosteroids. Several animal models have been developed to assist in determining efficacy of immunosuppression in AIED, and several clinical studies have also investigated the role of both steroid and steroid-sparing treatments. Here we discuss the basic science and clinical research surrounding the history of immunosuppressive therapy in AIED. PMID:19885385

  1. The windows of the inner ear.

    PubMed

    Thomson, S; Madani, G

    2014-03-01

    The oval and round windows of the inner ear are important structures for the transmission of sound and may be affected by a variety of disease entities. The anatomy of this small area is one that often causes the radiology trainee some difficulty, but there are certain disease states that can be easily diagnosed when knowing where and how to look. As this area is very important to the otologist in a variety of preoperative settings, accurate assessment of the windows and recognition of important and potentially complex intra-operative anomalies, will greatly aid our surgical colleagues. PMID:24365668

  2. Fly-ear inspired acoustic sensors for gunshot localization

    NASA Astrophysics Data System (ADS)

    Liu, Haijun; Currano, Luke; Gee, Danny; Yang, Benjamin; Yu, Miao

    2009-05-01

    The supersensitive ears of the parasitoid fly Ormia ochracea have inspired researchers to develop bio-inspired directional microphone for sound localization. Although the fly ear is optimized for localizing the narrow-band calling song of crickets at 5 kHz, experiments and simulation have shown that it can amplify directional cues for a wide frequency range. In this article, a theoretical investigation is presented to study the use of fly-ear inspired directional microphones for gunshot localization. Using an equivalent 2-DOF model of the fly ear, the time responses of the fly ear structure to a typical shock wave are obtained and the associated time delay is estimated by using cross-correlation. Both near-field and far-field scenarios are considered. The simulation shows that the fly ear can greatly amplify the time delay by ~20 times, which indicates that with an interaural distance of only 1.2 mm the fly ear is able to generate a time delay comparable to that obtained by a conventional microphone pair with a separation as large as 24 mm. Since the parameters of the fly ear structure can also be tuned for muzzle blast and other impulse stimulus, fly-ear inspired acoustic sensors offers great potential for developing portable gunshot localization systems.

  3. Magnetically driven middle ear ossicles for optical measurement of vibrations in an ear with opened eardrum

    NASA Astrophysics Data System (ADS)

    Peacock, John; Von Unge, Magnus; Dirckx, Joris

    2012-06-01

    Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, exposing the ossicles requires the removal of the eardrum, with the result that the ossicles can no longer be stimulated acoustically. To overcome this we devised a new set up in which the ossicles can be driven magnetically. After measuring the response of the eardrum to an acoustic signal, we then remove the eardrum and attach a small magnet to the exposed manubrium (the part of the first auditory ossicle, the malleus, which is normally attached to the eardrum). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a set-up has uses in research on middle ear mechanics, such as the measurement of non-linearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis, or in chronic otitis media. We describe our set up in which the vibrometer unit is attached to a surgical microscope, offering accurate positioning of the laser beam. We discuss the viability of our method and its future potential by presenting some measurements on artificially fixated ears.

  4. Empirical Evaluation of Advanced Ear Biometrics Ping Yan Kevin W. Bowyer

    E-print Network

    Bowyer, Kevin W.

    Empirical Evaluation of Advanced Ear Biometrics Ping Yan Kevin W. Bowyer Department of Computer experimental inves- tigation of ear biometrics to date. Approaches consid- ered include a PCA ("eigen-ear the robustness and variability of ear biometrics, ear symmetry is also in- vestigated. In our experiments around

  5. Vibrations in the human middle ear

    PubMed Central

    Rusinek, Rafa?; Szyma?ski, Marcin; Warmi?ski, Jerzy; Zadrozniak, Marek; Morshed, Kamal

    2011-01-01

    Summary Background Middle ear surgery techniques can improve hearing destroyed by disease, but results of treatment are difficult to predict. Therefore, researchers use a Laser Doppler Vibrometer to measure vibrations of human middle ear ossicles. Material/Methods Measurements of ossicular chain vibrations are performed on fresh human temporal bone specimens using Laser Doppler Vibrometer. Vibrations of stapes are recorded in 3 cases: 1) for intact ossicular chain, 2) when incus long process is removed, and 3) after long process reconstruction with bone cement. A typical analysis of transfer function is completed by other methods applied in dynamics. Results Measurements and analysis of stapes vibrations in case of intact and damaged ossicular chain show regular and irregular behavior which can be recognize with the help of phase portraits, recurrence plots, correlation dimension, and Hurst and Lyapunov exponents. The long process reconstruction with bone cement gives good results in improving hearing. Conclusions Recurrence plots, and Lyapunov and Hurst exponents used in the study complete information obtained from transfer function and can be employed to enrich the classical approach to ossicular chain vibrations. PMID:22129895

  6. Control of antiviral defenses through hepatitis C virus disruption of retinoic acid-inducible gene-I signaling

    Microsoft Academic Search

    Eileen Foy; Kui Li; Rhea Sumpter Jr.; Yueh-Ming Loo; Cynthia L. Johnson; Chunfu Wang; Penny Mar Fish; Mitsutoshi Yoneyama; Takashi Fujita; Stanley M. Lemon; Michael Gale Jr.

    2005-01-01

    Hepatitis C virus (HCV) is a major human pathogen that infects 170 million people. A hallmark of HCV is its ability to establish persistent infections reflecting the evasion of host immunity and interference with \\/-IFN innate immune defenses. We demonstrate that disruption of retinoic acid-inducible gene I (RIG-I) signaling by the viral NS3\\/4A protease contributes to the ability of HCV

  7. Acid-induced gelation of whey protein polymers: effects of pH and calcium concentration during polymerization

    Microsoft Academic Search

    Michel Britten; Hélène J Giroux

    2001-01-01

    Heating whey protein dispersions (90°C for 15 min) at low ionic strength and pH values far from isoelectric point (pH>6.5) induced the formation of soluble polymers. The effect of mineral environment during heating on the hydrodynamic characteristics and acid-induced gelation properties of polymers was studied. Whey protein dispersions (80g\\/l) were denatured at different pH (6.5–8.5) and calcium concentrations (0–4mm) according

  8. A case of valproic acid-induced acute pancreatitis in tuberous sclerosis coexisting with end-stage renal disease.

    PubMed

    Capolongo, Giovanna; Zacchia, Miriam; Pollastro, Rosa Maria; Radice, Leonardo; Anastasio, Pietro

    2013-01-01

    Tuberous sclerosis complex (TCS) is a genetic disorder with a variable clinical presentation. It is commonly characterized by seizures, mental retardation and cutaneous angiofibromas. Renal manifestations frequently include angiomyolipomas and cysts which lead to chronic kidney disease. We report a case of valproic acid-induced acute pancreatitis in a dialysis patient affected by TCS. The case demonstrates the importance of assessing antiepileptic drug treatment in dialysis patients. PMID:22322816

  9. Comparative study on acid-induced gelation of myosin from Atlantic cod ( Gardus morhua) and burbot ( Lota lota)

    Microsoft Academic Search

    Siriporn Riebroy; Soottawat Benjakul; Wonnop Visessanguan; Ulf Erikson; Turid Rustad

    2008-01-01

    Physicochemical and rheological properties of myosin from Atlantic cod and burbot during acid-induced gelation at room temperature (22–23°C) by d-gluconic acid-?-lactone (GDL) were monitored. Turbidity and particle size of both myosins increased and salt soluble content decreased when pH decreased, suggesting the formation of protein aggregates caused by acidification. The formation of disulphide bonds in myosin gelation was induced by

  10. Endoplasmic Reticulum Stress and Store-Operated Calcium Entry Contribute to Usnic Acid-Induced Toxicity in Hepatic Cells.

    PubMed

    Chen, Si; Zhang, Zhuhong; Wu, Yuanfeng; Shi, Qiang; Yan, Hua; Mei, Nan; Tolleson, William H; Guo, Lei

    2015-07-01

    The use of usnic acid as a weight loss agent is a safety concern due to reports of acute liver failure in humans. Previously we demonstrated that usnic acid induces apoptosis and cytotoxicity in hepatic HepG2 cells. We also demonstrated that usnic acid induces autophagy as a survival mechanism against its cytotoxicity. In this study, we investigated and characterized further molecular mechanisms underlying the toxicity of usnic acid in HepG2 cells. We found that usnic acid causes endoplasmic reticulum (ER) stress demonstrated by the increased expression of typical ER stress markers, including CHOP, ATF-4, p-eIF2?, and spliced XBP1. Usnic acid inhibited the secretion of Gaussia luciferase measured by an ER stress reporter assay. An ER stress inhibitor 4-phenylbutyrate attenuated usnic acid-induced apoptosis. Moreover, usnic acid significantly increased the cytosolic free Ca(2+) concentration. Usnic acid increased the expression of calcium release-activated calcium channel protein 1 (CRAM1 or ORAI1) and stromal interaction molecule 1, two key components of store-operated calcium entry (SOCE), which is the major Ca(2+) influx pathway in non-excitable cells, this finding was also confirmed in primary rat hepatocytes. Furthermore, knockdown of ORAI1 prevented ER stress and ATP depletion in response to usnic acid. In contrast, overexpression of ORAI1 increased ER stress and ATP depletion caused by usnic acid. Taken together, our results suggest that usnic acid disturbs calcium homeostasis, induces ER stress, and that usnic acid-induced cellular damage occurs at least partially via activation of the Ca(2+) channel of SOCE. PMID:25870318

  11. Arachidonic acid- and docosahexaenoic acid-enriched formulas modulate antigen-specific T cell responses to influenza virus in

    Microsoft Academic Search

    Josep Bassaganya-Riera; Amir J Guri; Alexis M Noble; Kathryn A Reynolds; Jennifer King; Cynthia M Wood; Michael Ashby; Deshanie Rai; Raquel Hontecillas

    Background: Whereas the immunomodulatory effects of feeding either arachidonic acid (AA) or docosahexaenoic acid (DHA) sep- arately have been previously investigated, little is known about the immunomodulatory efficacy of AA or DHA when they are fed in combination as infant formula ingredients. Objective: The objective of this study was to investigate the ability of AA- and DHA(AA\\/DHA)-enriched infant formula to

  12. CO-EXPOSURE OF HUMAN AIRWAY EPITHELIAL CELLS TO OZONE AND PARTICULATE MATTER: EFFECTS ON ARACHIDONIC ACID METABOLISM

    EPA Science Inventory

    Co-exposure of human airway epithelial cells to ozone and particulate matter: effects on arachidonic acid metabolism. D. Stamm1, L. Dailey2, M.C. Madden2 1 University of North Carolina-Chapel Hill, School of Medicine 2 U.S. EPA, ORD, NHEERL, HSD, Chapel Hill, NC, USA...

  13. The influence of long chain polyunsaturate supplementation on docosahexaenoic acid and arachidonic acid in baboon neonate central nervous system

    Microsoft Academic Search

    Guan-Yeu Diau; Andrea T Hsieh; Eszter A Sarkadi-Nagy; Vasuki Wijendran; Peter W Nathanielsz; J Thomas Brenna

    2005-01-01

    BACKGROUND: Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are major components of the cerebral cortex and visual system, where they play a critical role in neural development. We quantitatively mapped fatty acids in 26 regions of the four-week-old breastfed baboon CNS, and studied the influence of dietary DHA and ARA supplementation and prematurity on CNS DHA and ARA concentrations. METHODS:

  14. Arachidonic acid (AA) is thought to serve as an intercellular messenger in many parts of the nervous system (Attwell et

    E-print Network

    Huettner, James E.

    Arachidonic acid (AA) is thought to serve as an intercellular messenger in many parts glutamate receptors (Dumuis et al. 1990). Exposure to cis-unsaturated fatty acids, including AA and docosahexaenoic acid (DHA), has been shown to modulate ionic currents in neurons as well as in other cell types

  15. Arachidonic Acid Accumulation and Delta-5 Desaturation in Felines After Feeding a Gamma-Linolenic Acid Enriched Diet 

    E-print Network

    Chamberlin, Amy Jo

    2011-02-22

    Feline lipid metabolism is a topic for greater exploration due to this specie?s unique characteristics. Cats express limited Delta 6-desaturase activity necessary for conversion of linoleic acid (LA, 18:2n-6) to arachidonic acid (AA, 20:4n-6...

  16. Arachidonic acid and linoleic acid supplementation increase prostanoid production in rats fed a butter-enriched diet.

    PubMed

    Steel, M S; Naughton, J M; Hopkins, G W; Sinclair, A J; O'Dea, K

    1990-08-01

    Male Sprague Dawley rats were fed a butter-enriched diet (50% fat) for 2 weeks and then supplemented orally with either 90 mg of ethyl arachidonate or ethyl linoleate daily for 2 weeks. For comparative reasons, one group of animals was fed standard laboratory rat chow for 4 weeks. Aortic prostacyclin (PGI2) production, platelet aggregation and thromboxane A2 (TXA2) production and plasma and aortic phospholipid (PL) fatty acids were measured. When compared to butter-fed rats, aortic PGI2 production, collagen-induced platelet aggregation and TXA2 production were significantly increased in rats supplemented with ethyl arachidonate to levels similar to those seen in chow-fed rats. Ethyl linoleate supplementation also tended to increase aortic PGI2 production, collagen-induced platelet aggregation and TXA2, but not to the same extent. These changes were accompanied by increases in the level of arachidonic acid and linoleic acid in aortic and plasma PL and a decrease in the level of eicosapentaenoic acid (EPA) and docsahexaenoic acid (DHA). These data indicate that supplementation with small doses of preformed arachidonic acid was more effective than supplementation with its precursor, linoleic acid, in reversing the effects on prostanoid production and phospholipid fatty acid composition in rats fed diets enriched with butter. PMID:2125728

  17. Mechanism for release of arachidonic acid during guinea pig platelet aggregation: a role for the diacylglycerol lipase inhibitor RHC 80267

    SciTech Connect

    Amin, D.

    1986-01-01

    The mechanism of the release of arachidonic acid from phospholipids after the stimulation of guinea pig platelets with collagen, thrombin and platelet activating factor (PAF) was studied. RHC 80267, a diacylglycerol lipase inhibitor, and indomethacin, a cyclooxygenase inhibitor, were used. Various in vitro assays for enzymes involved in arachidonic acid release and metabolism were conducted. Platelet aggregation and simultaneous release of ADP from platelets were monitored using a Chrono-log Lumiaggregometer. Platelets were labeled with (/sup 14/C)arachidonic acid to facilitate sensitive determination of small changes in platelet phospholipids during platelet aggregation. In the present investigation it is shown that collagen, thrombin and PAF increased phospholipase C activity. It was also discovered that cyclooxygenase products were responsible for further stimulation (a positive feed-back) of phospholipase C activity, while diacylglycerol provided a negative feed-back control over receptor-stimulated phospholipase C activity and inhibited ADP release. The guinea pig platelet is an ideal model to study phospholipase C-diacylglycerol lipase pathway for the release of arachidonic acid from platelet phospholipids because it does not have any phospholipase A/sub 2/ activity. It was observed that cyclooxygenase products were responsible for collagen-induced guinea pig platelet aggregation. Indomethacin completely inhibited collagen-induced platelet aggregation, was less effective against thrombin, and had no effect on PAF-induced platelet aggregation. On the other hand, RHC 80267 was a powerful inhibitor of aggregation and ADP release induced by all three of these potent aggregating agents.

  18. Vitamin E and vitamin C inhibit arachidonate-induced aggregation of human peripheral blood leukocytes in vitro

    Microsoft Academic Search

    S. Villa; A. Lorico; G. Morazzoni; G. de Gaetano; N. Semeraro

    1986-01-01

    Summary Arachidonate induces aggregation of human polymorphonuclear (PMN) and mononuclear (MNL) blood leukocytes. This is mediated by the lipoxygenase pathway, as it is prevented by lipoxygenase inhibitors and can also be induced by leukotriene B4 (LTB4). Vitamin E and vitamin C have profound effects on the functional state of leukocytes, some of which may involve the lipoxygenase pathway. This study

  19. The biosynthesis of N-arachidonoyl dopamine (NADA), a putative endocannabinoid and endovanilloid, via conjugation of arachidonic acid with dopamine

    Microsoft Academic Search

    Sherry Shu-Jung Hu; Heather B. Bradshaw; Valery M. Benton; Jay Shih-Chieh Chen; Susan M. Huang; Alberto Minassi; Tiziana Bisogno; Kim Masuda; Bo Tan; Robert Roskoski Jr.; Benjamin F. Cravatt; Vincenzo Di Marzo; J. Michael Walker

    2009-01-01

    N-arachidonoyl dopamine (NADA) is an endogenous ligand that activates the cannabinoid type 1 receptor and the transient receptor potential vanilloid type 1 channel. Two potential biosynthetic pathways for NADA have been proposed, though no conclusive evidence exists for either. The first is the direct conjugation of arachidonic acid with dopamine and the other is via metabolism of a putative N-arachidonoyl

  20. Retinoic acid-induced blr1 expression promotes ERK2 activation and cell differentiation in HL-60 cells.

    PubMed

    Battle, T E; Levine, R A; Yen, A

    2000-02-01

    Retinoids are known to induce the differentiation and cell cycle arrest of human myeloid leukemia cells in vitro. Differential display was used to identify putative early regulatory genes that are differentially expressed in HL-60 human promyelocytic leukemia cells treated with retinoic acid. One of the cDNAs cloned encodes sequences identifying Burkitt's lymphoma receptor 1 (BLR1), a recently described chemokine receptor. Northern blot analysis demonstrates that blr1 mRNA expression increases within 9 h of retinoic acid treatment, well before functional differentiation or G(1)/G(0) growth arrest at 48 h or onset of morphological changes, suggesting a possible regulatory function. The expression of blr1 mRNA is transient, peaking at 72 h when cells are differentiated. blr1 mRNA also is induced by other differentiation-inducing agents, 1alpha,25-dihydroxyvitamin D(3) and DMSO. Induction of blr1 mRNA by retinoic acid is not blocked by the protein synthesis inhibitor cycloheximide. In HL-60 cells stably transfected with blr1 cDNA, ectopic expression of blr1 causes an increase in ERK2 MAPK activation and promotes retinoic acid-induced G(1)/G(0) growth arrest and cell differentiation. The early expression of blr1 mRNA during differentiation, its ability to increase ERK2 activation, and its enhancement of retinoic acid-induced differentiation suggest that blr1 expression may be involved in retinoic acid-induced HL-60 differentiation. PMID:10640427

  1. Within-ear and across-ear interference in a cocktail-party listening task Douglas S. Brungart1 and Brian D. Simpson2

    E-print Network

    Allen, Jont

    Within-ear and across-ear interference in a cocktail-party listening task Douglas S. Brungart1 talker is present in the same ear as the target speech or when a masking talker is present in a different ear than the target speech, little is known about selective auditory attention in tasks with a target

  2. 496. Phys. Lett A., (2006) A.G.Ramm, The shape of the ear canal The shape of the ear canal #+

    E-print Network

    2006-01-01

    496. Phys. Lett A., (2006) A.G.Ramm, The shape of the ear canal 1 #12; The shape of the ear canal@math.ksu.edu Abstract It is proved that the measurement of the acoustic pressure on the ear membrane allows one to determine the shape of the ear canal uniquely. 1 Introduction Consider a bounded domain D # R n , n = 3

  3. Distinct roles for Wnt-4 and Wnt-11 during retinoic acid-induced neuronal differentiation.

    PubMed

    Elizalde, Carina; Campa, Victor M; Caro, Mercedes; Schlangen, Karin; Aransay, Ana María; Vivanco, Maria dM; Kypta, Robert M

    2011-01-01

    Retinoic acid and Wnt/?-catenin signals play important roles during neuronal differentiation but less is known about noncanonical Wnt signals in this context. We examined retinoic acid and Wnt signaling in two human embryonal carcinoma cell lines, NTERA-2 (clone D1), which undergoes neuronal differentiation in response to retinoic acid, and 2102Ep, which does not. Retinoic acid treatment inhibited ?-catenin/Tcf activity in NTERA-2 cells but not in 2102Ep cells. Inhibition occurred downstream of ?-catenin but did not involve competition between retinoic acid receptors and ?-catenin for binding to p300 or Tcf-4. Ectopic expression of FZD1 partially restored inhibition in 2102Ep cells, suggesting the involvement of Wnt ligands. Retinoic acid treatment of NTERA-2 cells induced the expression of Wnt-4 and Wnt-11, both of which were able to inhibit ?-catenin/Tcf activity. Wnt-4 and Wnt-11 were found at cell borders in islands of cells that expressed OCT4 and GFAP and were predominantly negative for Nestin, PAX6, and GATA6. Gene silencing of Wnt-4, but not Wnt-11, reduced retinoic acid downregulation of OCT4 and Nanog and upregulation of PAX6, ASCL1, HOXC5, and NEUROD1, suggesting that Wnt-4 promotes early neuronal differentiation. Gene expression analysis of NTERA-2 cells stably overexpressing Wnt-11 suggested that Wnt-11 potentiates retinoic acid induction of early neurogenesis. Consistent with this, overexpression of Wnt-11 maintained a population of proliferating progenitor cells in cultures treated with retinoic acid for several weeks. These observations highlight the distinct roles of two noncanonical Wnts during the early stages of retinoic acid-induced neuronal differentiation. PMID:21280163

  4. Human sweet taste receptor mediates acid-induced sweetness of miraculin.

    PubMed

    Koizumi, Ayako; Tsuchiya, Asami; Nakajima, Ken-ichiro; Ito, Keisuke; Terada, Tohru; Shimizu-Ibuka, Akiko; Briand, Loïc; Asakura, Tomiko; Misaka, Takumi; Abe, Keiko

    2011-10-01

    Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Nevertheless, no molecular mechanism underlying the taste-modifying activity has been clarified. In this study, we succeeded in quantitatively evaluating the acid-induced sweetness of MCL using a cell-based assay system and found that MCL activated hT1R2-hT1R3 pH-dependently as the pH decreased from 6.5 to 4.8, and that the receptor activation occurred every time an acid solution was applied. Although MCL per se is sensory-inactive at pH 6.7 or higher, it suppressed the response of hT1R2-hT1R3 to other sweeteners at neutral pH and enhanced the response at weakly acidic pH. Using human/mouse chimeric receptors and molecular modeling, we revealed that the amino-terminal domain of hT1R2 is required for the response to MCL. Our data suggest that MCL binds hT1R2-hT1R3 as an antagonist at neutral pH and functionally changes into an agonist at acidic pH, and we conclude this may cause its taste-modifying activity. PMID:21949380

  5. Pistacia lentiscus resin regulates intestinal damage and inflammation in trinitrobenzene sulfonic acid-induced colitis.

    PubMed

    Gioxari, Aristea; Kaliora, Andriana C; Papalois, Apostolos; Agrogiannis, George; Triantafillidis, John K; Andrikopoulos, Nikolaos K

    2011-11-01

    Mastic (Pistacia lentiscus) of the Anacardiaceae family has exhibited anti-inflammatory and antioxidant properties in patients with Crohn's disease. This study was based on the hypothesis that mastic inhibits intestinal damage in inflammatory bowel disease, regulating inflammation and oxidative stress in intestinal epithelium. Four different dosages of P. lentiscus powder in the form of powder were administered orally to trinitrobenzene sulfonic acid-induced colitic rats. Eighty-four male Wistar rats were randomly assigned to seven groups: A, control; B, colitic; C-F, colitic rats daily supplemented with P. lentiscus powder at (C) 50 mg/kg, (D) 100 mg/kg, (E) 200 mg/kg, and (F) 300 mg/kg of body weight; and G, colitic rats treated daily with cortisone (25 ?g/kg of body weight). Colonic damage was assessed microscopically. The cytokines tumor necrosis factor-?, intercellular adhesion molecule-1 (ICAM-1), interleukin (IL)-6, IL-8, and IL-10 and malonaldehyde were measured in colonic specimens. Results were expressed as mean ± SE values. Histological amelioration of colitis (P?.001) and significant differences in colonic indices occurred after 3 days of treatment. Daily administration of 100 mg of P. lentiscus powder/kg of body weight decreased all inflammatory cytokines (P?.05), whereas 50 mg of P. lentiscus powder/kg of body weight and cortisone treatment reduced only ICAM-1 (P?.05 and P?.01, respectively). Malonaldehyde was significantly suppressed in all treated groups (P?.01). IL-10 remained unchanged. Cytokines and malonaldehyde remained unaltered after 6 days of treatment. Thus P. lentiscus powder could possibly have a therapeutic role in Crohn's disease, regulating oxidant/antioxidant balance and modulating inflammation. PMID:21612460

  6. Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis.

    PubMed

    Woolbright, Benjamin L; Dorko, Kenneth; Antoine, Daniel J; Clarke, Joanna I; Gholami, Parviz; Li, Feng; Kumer, Sean C; Schmitt, Timothy M; Forster, Jameson; Fan, Fang; Jenkins, Rosalind E; Park, B Kevin; Hagenbuch, Bruno; Olyaee, Mojtaba; Jaeschke, Hartmut

    2015-03-15

    Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. PMID:25636263

  7. Human sweet taste receptor mediates acid-induced sweetness of miraculin

    PubMed Central

    Koizumi, Ayako; Tsuchiya, Asami; Nakajima, Ken-ichiro; Ito, Keisuke; Terada, Tohru; Shimizu-Ibuka, Akiko; Briand, Loïc; Asakura, Tomiko; Misaka, Takumi; Abe, Keiko

    2011-01-01

    Miraculin (MCL) is a homodimeric protein isolated from the red berries of Richadella dulcifica. MCL, although flat in taste at neutral pH, has taste-modifying activity to convert sour stimuli to sweetness. Once MCL is held on the tongue, strong sweetness is sensed over 1 h each time we taste a sour solution. Nevertheless, no molecular mechanism underlying the taste-modifying activity has been clarified. In this study, we succeeded in quantitatively evaluating the acid-induced sweetness of MCL using a cell-based assay system and found that MCL activated hT1R2-hT1R3 pH-dependently as the pH decreased from 6.5 to 4.8, and that the receptor activation occurred every time an acid solution was applied. Although MCL per se is sensory-inactive at pH 6.7 or higher, it suppressed the response of hT1R2-hT1R3 to other sweeteners at neutral pH and enhanced the response at weakly acidic pH. Using human/mouse chimeric receptors and molecular modeling, we revealed that the amino-terminal domain of hT1R2 is required for the response to MCL. Our data suggest that MCL binds hT1R2-hT1R3 as an antagonist at neutral pH and functionally changes into an agonist at acidic pH, and we conclude this may cause its taste-modifying activity. PMID:21949380

  8. Protective effects of mossy fiber lesions against kainic acid-induced seizures and neuronal degeneration.

    PubMed

    Okazaki, M M; Nadler, J V

    1988-09-01

    The effects of a hippocampal mossy fiber lesion have been determined on neuronal degeneration and limbic seizures provoked by the subsequent intracerebroventricular administration of kainic acid to unanesthetized rats. Mossy fiber lesions were made either by transecting this pathway unilaterally or by destroying the dentate granule cells unilaterally or bilaterally with colchicine. All control rats eventually developed status epilepticus and each temporally discrete seizure that preceded status epilepticus was recorded from the hippocampus ipsilateral to the kainic acid infusion before the contralateral hippocampus. A mossy fiber lesion of the ipsilateral hippocampus prevented the development of status epilepticus in 26% of subjects and in 52% of subjects seizures were recorded from the contralateral hippocampus before the ipsilateral hippocampus. Unlike electrographic records from other treatment groups, those from rats which had received a bilateral colchicine lesion exhibited no consistent pattern indicative of seizure propagation from one limbic region to another. A bilateral, but not a unilateral, mossy fiber lesion also dramatically attenuated the behavioral expression of the seizures. Regardless of its effects on kainic acid-induced electrographic and behavioral seizures, a mossy fiber lesion always substantially reduced or completely prevented the degeneration of ipsilateral hippocampal CA3-CA4 neurons. This protective effect was specific for those hippocampal neurons deprived of mossy fiber innervation. Neurons in other regions of the brain were protected from degeneration only when the mossy fiber lesion also prevented the development of electrographic status epilepticus. These results suggest that the hippocampal mossy fibers constitute an important, though probably not an obligatory, link in the circuit responsible for the spread of kainic acid seizures. Degeneration of CA3-CA4 neurons appears to depend upon (1) the duration of hippocampal seizure activity and (2) an as yet undefined influence of or interaction with the mossy fiber projection which enhances the neurodegenerative effect of the seizures. PMID:3200428

  9. The maize rachis affects Aspergillus flavus movement during ear development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus expressing green fluorescent protein (GFP) was used to follow infection in ears of maize hybrids resistant and susceptible to the fungus. Developing ears were needle-inoculated with GFP-transformed A. flavus 20 days after silk emergence, and GFP fluorescence in the pith was evalu...

  10. Replantation of an avulsed ear, using a single arterial anastamosis.

    PubMed

    O'Toole, G; Bhatti, K; Masood, S

    2008-01-01

    Avulsion of the ear is relatively uncommon and replantation a technical challenge. A case in which an avulsed ear was successfully replanted using a single arterial anastamosis is described. The surgical difficulties encountered, the pharmaceutical approach to postoperative care and the problems which resulted from the lack of venous drainage are discussed. PMID:18061545

  11. Sound direction estimation using an artificial ear for robots

    Microsoft Academic Search

    Sungmok Hwang; Youngjin Park; Youn-sik Park

    2011-01-01

    We propose a novel design of an artificial robot ear for sound direction estimation using two measured outputs only. The spectral features in the interaural transfer functions (ITFs) of the proposed artificial ears are distinctive and move monotonically according to the sound direction. Thus, these features provide effective sound cues to estimate sound direction using the measured two output signals.

  12. Artificial Robot Ear Design for Sound Direction Estimation

    Microsoft Academic Search

    Youngjin Park; Sungmok Hwang

    2007-01-01

    We propose a novel design of artificial robot ear for sound direction estimation using measured two outputs only. The spectral features in head-related transfer functions and in interaural transfer functions (ITFs) are distinctive in the voice frequency band. Thus, these features provide effective sound cues to estimate the sound direction using two measured ear outputs only without input information. Especially,

  13. Mechanism and Rate of Middle Ear Fluid Absorption

    Microsoft Academic Search

    Petia Petrova; Sharon Freeman; Haim Sohmer

    2007-01-01

    Several mechanisms have been suggested to explain the clearance of fluids from the middle ear. These include a pumping action through the eustachian tube, mucociliary beating through the tube, outflow of water to the blood due to osmotic gradients and an active Na+ transport driving water absorption. In order to assess these mechanisms, the middle ear cavity of paralyzed, ventilated

  14. Can you hear me now? Understanding vertebrate middle ear development

    PubMed Central

    Chapman, Susan Caroline

    2010-01-01

    The middle ear is a composite organ formed from all three germ layers and the neural crest. It provides the link between the outside world and the inner ear, where sound is transduced and routed to the brain for processing. Extensive classical and modern studies have described the complex morphology and origin of the middle ear. Non-mammalian vertebrates have a single ossicle, the columella. Mammals have three functionally equivalent ossicles, designated the malleus, incus and stapes. In this review, I focus on the role of genes known to function in the middle ear. Genetic studies are beginning to unravel the induction and patterning of the multiple middle ear elements including the tympanum, skeletal elements, the air-filled cavity, and the insertion point into the inner ear oval window. Future studies that elucidate the integrated spatio-temporal signaling mechanisms required to pattern the middle ear organ system are needed. The longer-term translational benefits of understanding normal and abnormal ear development will have a direct impact on human health outcomes. PMID:21196256

  15. Rhabdomyosarcoma in middle ear of an adult: a rare presentation.

    PubMed

    Bhargava, S; Grover, M; Mehta, J; Maheshwari, V

    2012-01-01

    Rhabdomyosarcoma of the middle ear is a rare tumor, even rarer in adults and has a very poor prognosis. We report here an unusual case of rhabdomyosarcoma in middle ear of an adult, mimicking chronic suppurative otitis media and facial nerve palsy. PMID:24960749

  16. The correlation of middle ear aeration with mastoid pneumatization

    Microsoft Academic Search

    J. Sadé

    1992-01-01

    Atelectatic ears, which by definition are poorly aerated, are also usually associated with poor mastoid pneumatization. On the other hand, otosclerotic patients, whose middle ears are usually exceptionally well aerated, also have excellent mastoid pneumatization. Three unusual cases are presented, in which partial atelectasis developed in stapedectomized patients. In each case the mastoid was later found to be nonpneumatized, and

  17. [Significance of the ear in the determination of age].

    PubMed

    Röhm, E; Adam, E

    1986-01-01

    The morphology of human ear conch is said to be rather individual, but a perfect person-identification by this mean is not possible. It is demonstrated by photographs-made in a 15 years' interval-that ear conch and auricular area can be typically marked by proceeding age and specific diseases. PMID:3741048

  18. Alternative Ear-Canal Measures Related to Absorbance

    PubMed Central

    Neely, Stephen T.; Stenfelt, Stefan; Schairer, Kim S.

    2013-01-01

    Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1) sound intensity level (SIL), (2) forward-pressure level (FPL), (3) time-domain ear-canal reflectance (TDR), and (4) cochlear reflectance (CR). These four related measures are similar to absorbance in their utilization of wide-band stimuli and their focus on recording ear-canal sound pressure. The related measures differ from absorbance in how the ear-canal pressure is analyzed and in the type of information that is extracted from the recorded response. SIL and FPL have both been shown to be better as measures of sound level in the ear canal compared to sound pressure level (SPL) because they reduced calibration errors due to standing waves in studies of behavioral thresholds and otoacoustic emissions. TDR may be used to estimate ear-canal geometry and may have the potential to assess middle-ear pathology. CR reveals information about the inner ear that is similar to what is provided by other types of otoacoustic emissions and may have theoretical advantages that strengthen its interpretation. PMID:23900185

  19. Pedigree selection for Gibberella ear rot resistance in maize

    Microsoft Academic Search

    Daniel A. Presello; Lana M. Reid; Gail Butler; Diane E. Mather

    2005-01-01

    The pedigree method is often used for developing inbred lines in maize (Zea mays L.). This study was conducted to assess the effectiveness of pedigree selection for improving resistance to Gibberella ear rot in four maize populations. Selection was based on the severity of ear rot symptoms after inoculation with macroconidial suspensions of Fusarium graminearum (Schwabe) into the silk channel

  20. Middle Ear Resonance and Acoustic Immittance Measures in Children.

    ERIC Educational Resources Information Center

    Hanks, Wendy D.; Rose, Katie J.

    1993-01-01

    This study established a normal middle ear resonance estimated from sweep frequency tympanometry, established normal equivalent ear canal volume, static acoustic admittance, and tympanometric peak pressure at 226 hertz in 90 children with normal hearing and 68 children with deafness, ages 6-15. No significant intergroup or age differences were…

  1. Preventing Cauliflower Ear with a Modified Tie-Through Technique.

    ERIC Educational Resources Information Center

    Dimeff, Robert J.; Hough, David O.

    1989-01-01

    Describes a quick, simple tie-through suture technique (in which a collodion packing is secured to the auricle with two buttons) for preventing cauliflower ear following external ear trauma in wrestlers and boxers. The technique ensures constant compression; multiple treatments for fluid reaccumulation are rarely necessary. (SM)

  2. The arachidonic acid metabolome serves as a conserved regulator of cholesterol metabolism.

    PubMed

    Demetz, Egon; Schroll, Andrea; Auer, Kristina; Heim, Christiane; Patsch, Josef R; Eller, Philipp; Theurl, Markus; Theurl, Igor; Theurl, Milan; Seifert, Markus; Lener, Daniela; Stanzl, Ursula; Haschka, David; Asshoff, Malte; Dichtl, Stefanie; Nairz, Manfred; Huber, Eva; Stadlinger, Martin; Moschen, Alexander R; Li, Xiaorong; Pallweber, Petra; Scharnagl, Hubert; Stojakovic, Tatjana; März, Winfried; Kleber, Marcus E; Garlaschelli, Katia; Uboldi, Patrizia; Catapano, Alberico L; Stellaard, Frans; Rudling, Mats; Kuba, Keiji; Imai, Yumiko; Arita, Makoto; Schuetz, John D; Pramstaller, Peter P; Tietge, Uwe J F; Trauner, Michael; Norata, Giuseppe D; Claudel, Thierry; Hicks, Andrew A; Weiss, Guenter; Tancevski, Ivan

    2014-11-01

    Cholesterol metabolism is closely interrelated with cardiovascular disease in humans. Dietary supplementation with omega-6 polyunsaturated fatty acids including arachidonic acid (AA) was shown to favorably affect plasma LDL-C and HDL-C. However, the underlying mechanisms are poorly understood. By combining data from a GWAS screening in >100,000 individuals of European ancestry, mediator lipidomics, and functional validation studies in mice, we identify the AA metabolome as an important regulator of cholesterol homeostasis. Pharmacological modulation of AA metabolism by aspirin induced hepatic generation of leukotrienes (LTs) and lipoxins (LXs), thereby increasing hepatic expression of the bile salt export pump Abcb11. Induction of Abcb11 translated in enhanced reverse cholesterol transport, one key function of HDL. Further characterization of the bioactive AA-derivatives identified LX mimetics to lower plasma LDL-C. Our results define the AA metabolomeasconserved regulator of cholesterol metabolism, and identify AA derivatives as promising therapeutics to treat cardiovascular disease in humans. PMID:25444678

  3. Arachidonic acid diet attenuates brain A? deposition in Tg2576 mice.

    PubMed

    Hosono, Takashi; Nishitsuji, Kazuchika; Nakamura, Toshiyuki; Jung, Cha-Gyun; Kontani, Masanori; Tokuda, Hisanori; Kawashima, Hiroshi; Kiso, Yoshinobu; Suzuki, Toshiharu; Michikawa, Makoto

    2015-07-10

    The amyloid ?-protein (A?) is believed to play a causative role in the development of Alzheimer?s disease (AD). Because the amyloid precursor protein (APP), a substrate of A?, and ?-secretase and ?-secretase complex proteins, which process APP to generate A?, are all membrane proteins, it is possible to assume that alterations in brain lipid metabolism modulate APP and/or A? metabolism. However, the role of polyunsaturated fatty acids in A? metabolism remains unknown. We report here that 9 months-treatment of Tg2576 mice with arachidonic acid (ARA)-containing (ARA+) diet prevented brain A? deposition in 17-month-old Tg2576 mice. APP processing to generate soluble APP?, CTF-?, and A? synthesis was attenuated in Tg2576 mice fed with the ARA+ diet. These findings suggest that ARA+ diet could prevent A? deposition through the alteration of APP processing in Tg2576 mice. PMID:25881896

  4. Arachidonic Acid Derivatives and Their Role in Peripheral Nerve Degeneration and Regeneration

    PubMed Central

    Camara-Lemarroy, Carlos Rodrigo; Gonzalez-Moreno, Emmanuel Irineo; Guzman-de la Garza, Francisco Javier; Fernandez-Garza, Nancy Esthela

    2012-01-01

    After peripheral nerve injury, a process of axonal degradation, debris clearance, and subsequent regeneration is initiated by complex local signaling, called Wallerian degeneration (WD). This process is in part mediated by neuroglia as well as infiltrating inflammatory cells and regulated by inflammatory mediators such as cytokines, chemokines, and the activation of transcription factors also related to the inflammatory response. Part of this neuroimmune signaling is mediated by the innate immune system, including arachidonic acid (AA) derivatives such as prostaglandins and leukotrienes. The enzymes responsible for their production, cyclooxygenases and lipooxygenases, also participate in nerve degeneration and regeneration. The interactions between signals for nerve regeneration and neuroinflammation go all the way down to the molecular level. In this paper, we discuss the role that AA derivatives might play during WD and nerve regeneration, and the therapeutic possibilities that arise. PMID:22997489

  5. Identification of arachidonic acid and its metabolism in Gulf of Mexico shrimp

    E-print Network

    Lilly, Martha Lae

    1980-01-01

    these precur- sors by elongation and desaturation. When shrimp were fed high levels of 18:2w6 or 18:3w3, the results were quite differ nt (4, 5, 6) . The tissue levels of these C18 acids increased markedly, while the levels of the C2p and C2 2 pclyenes... results, the existence of a pathway for the conversion of linoleic acid to arachidonic acid via 18:3w6 and 20:3w6. An alternate pathway via 20:2w6 was demonstrated by Klenk and iMohrhauer (13), but it was later shown by Marcel (2) that the o iginal...

  6. The Synthesis and In Vivo Pharmacokinetics of Fluorinated Arachidonic Acid: Implications for Imaging Neuroinflammation

    PubMed Central

    Pichika, Rama; Taha, Ameer Y.; Gao, Fei; Kotta, Kishore; Cheon, Yewon; Chang, Lisa; Kiesewetter, Dale; Rapoport, Stanley I.; Eckelman, William C.

    2012-01-01

    Arachidonic acid (AA) is found in high concentrations in brain phospholipids and is released as a second messenger during neurotransmission and much more so during neuroinflammation and excitotoxicity. Upregulated brain AA metabolism associated with neuroinflammation has been imaged in rodents using [1-14C]AA and with PET in Alzheimer disease patients using [1-11C]AA. Radiotracer brain AA uptake is independent of cerebral blood flow, making it an ideal tracer despite altered brain functional activity. However, the 20.4-min radioactive half-life of 11C-AA and challenges of routinely synthesizing 11C fatty acids limit their translational utility as PET biomarkers. Methods As a first step to develop a clinically useful 18F-fluoroarachidonic acid (18F-FAA) with a long radioactive half-life of 109.8 min, we report here a high-yield stereoselective synthetic method of non-radioactive 20-19F-FAA. We tested its in vivo pharmacokinetics by infusing purified nonradioactive 19F-FAA intravenously for 5 min at 2 doses in unanesthetized mice and measured its plasma and brain distribution using gas chromatography–mass spectrometry. Results Incorporation coefficients of injected 19F-FAA into brain phospholipids (ratio of brain 19F-FAA concentration to plasma input function) were 3- to 29-fold higher for choline glycerophospholipid and phosphatidylinositol than for ethanolamine glycerophospholipid and phosphatidylserine at each of the 2 tested doses. The selectivities and values of incorporation coefficients were comparable to those reported after [1-14C]AA (the natural arachidonate) infusion in mice. Conclusion These results suggest that it would be worthwhile to translate our stereoselective synthetic method for 19F-FAA to synthesize positron-emitting 18F-FAA for human brain AA metabolism in neuroinflammatory disorders such as Alzheimer disease. PMID:22851635

  7. Arachidonic acid as a retrograde signal controlling growth and dynamics of retinotectal arbors.

    PubMed

    Leu, B H; Schmidt, J T

    2008-01-01

    In the developing visual system, correlated presynaptic activity between neighboring retinal ganglion cells (RGC) stabilizes retinotopic synapses via a postsynaptic NMDAR (N-methyl-D-aspartate receptor)-dependent mechanism. Blocking NMDARs makes individual axonal arbors larger, which underlies an unsharpened map, and also increases branch turnover, as if a stabilizing factor from the postsynaptic partner is no longer released. Arachidonic acid (AA), a candidate retrograde stabilizing factor, is released by cytoplasmic phospholipase A2 (cPLA2) after Ca(2+) entry through activated NMDARs, and can activate presynaptic protein kinase C to phosphorylate various substrates such as GAP43 to regulate cytoskeletal dynamics. To test the role of cPLA2 in the retinotectal system of developing zebrafish, we first used PED6, a fluorescent reporter of cPLA2 activity, to show that 1-3 min of strobe flashes activated tectal cPLA2 by an NMDAR-dependent mechanism. Second, we imaged the dynamic growth of retinal arbors during both local inhibition of tectal cPLA2 by a pharmacological inhibitor, arachidonic tri-fluoromethylketone, and its suppression by antisense oligonucleotides (both injected intraventricularly). Both methods produced larger arbors and faster branch dynamics as occurs with blocking NMDARs. In contrast, intraocular suppression of retinal cPLA2 with large doses of antisense oligos produced none of the effects of tectal cPLA2 inhibition. Finally, if AA is the retrograde messenger, the application of exogenous AA to the tectum should reverse the increased branch turnover caused by blocking either NMDARs or cPLA2. In both cases, intraventricular injection of AA stabilized the overall branch dynamics, bringing rates down below the normal values. The results suggest that AA generated postsynaptically by cPLA2 downstream of Ca(2+) entry through NMDARs acts as a retrograde signal to regulate the dynamic growth of retinal arbors. PMID:17918241

  8. Absorption and lymphatic transport of exogenous and endogenous arachidonic and linoleic acid in the rat

    SciTech Connect

    Nilsson, A.; Landin, B.; Jensen, E.; Akesson, B.

    1987-06-01

    (/sup 3/H)Arachidonic (20:4) and (/sup 14/C)linoleic acid (18:2) were fed to thoracic duct-cannulated rats in test meals of either tracers alone, cream, Intralipid, pure arachidonic acid, or pure linoleic acid. Less (/sup 3/H)20:4 than (/sup 14/C)18:2 was recovered in chyle during the first 5 h. After cream feeding, the proportion of radioactivity found in phospholipids was high and increased during the first 3 h. After the meal 61 +/- 6% of the /sup 3/H and 57 +/- 10% of the /sup 14/C was in phosphatidylcholine, and 11 +/- 3% of the /sup 3/H and 3.0 +/- 4% of the /sup 14/C was in phosphatidylethanolamine. Changing the fat vehicle to Intralipid or pure 18:2 decreased the proportion of label in the phospholipds and increased the /sup 3/H and /sup 14/C radioactivity in the triacylglycerol fraction, the distribution of /sup 14/C radioactivity in the triacylglycerol fraction, the distribution of /sup 14/C being influenced more than that of /sup 3/H. After feeding the tracers in 200 ..mu..l of pure 20:4, >90% of both isotopes was in triacylglycerol. During fasting, triacylglycerol transported 56% (0.7 ..mu..mol/h), phosphatidylethanolamine transported 10% (0.1 ..mu..mol/h) of the 20:4 mass. After cream or Intralipid feeding, the output of 20:4-containing phosphatidylcholine and phosphatidylethanolamine increased 2.1- to 2.8-fold, whereas the transport of 20:4 with triacylglycerol remained constant. Phospholipids thus became the predominant transport form for 20:4. After feeding 200 ..mu..l of 20:4, the intestine produced, however, 20:4-rich triacylglycerols that transported 80% of the chyle 20:4.

  9. Labelling of lipids and phospholipids with [3H]arachidonic acid and the biosynthesis of eicosanoids in U937 cells differentiated by phorbol ester.

    PubMed

    Wiederhold, M D; Anderson, K M; Harris, J E

    1988-04-15

    Phorbol esters induce morphologic and biochemical differentiation in U937 cells, a monocyte/macrophage-like line derived from a human histiocytic lymphoma. We are interested in the phorbol ester-stimulated release of arachidonic acid from cellular membranes and the subsequent synthesis of eicosanoids, as it may prove to correlate with the induced cellular differentiation. Undifferentiated log-phase U937 cells released little recently incorporated [3H]arachidonic acid, but phorbol 12-myristate 13-acetate increased its apparent rate of release to that of cells differentiated by exposure to phorbol myristate acetate for 3 days. Exposure of washed differentiated cells immediately prelabelled with [3H]arachidonic acid to additional phorbol myristate acetate did not augment the release of [3H]arachidonic acid. The basal release of nonradioactive fatty acids from differentiated cells was 5-10 times that of undifferentiated cells, and phorbol myristate acetate increased their release from both types of cell 2- to 3-fold. Differentiated cells immediately prelabelled with [3H]arachidonic acid exhibited greater incorporation into phosphatidylinositol and phosphatidylcholine, and contained more radioactive free arachidonic acid, compared with undifferentiated cells. Undifferentiated cells contained more radioactivity in phosphatidylserine, phosphatidylethanolamine and neutral lipids. Phorbol myristate acetate caused differentiated cells to release [3H]arachidonic acid from phosphatidylinositol, phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine, but release from neutral lipids was reduced, and the content of [3H]arachidonic acid increased. In undifferentiated cells incubated with phorbol myristate acetate, radioactivity associated with phosphatidylserine, phosphatidylethanolamine and neutral lipid was reduced and [3H]arachidonic acid was unchanged. Synthesis of cyclooxygenase products exceeded that of lipoxygenase products in both differentiated and undifferentiated cells. Phorbol myristate acetate increased the synthesis of both types of product, cyclooxygenase-dependent more than lipoxygenase-dependent, especially in differentiated cells. The biological significance of these changes in lipid metabolism that accompany phorbol myristate acetate-induced differentiation are yet to be established. PMID:3128336

  10. Ear Infection and Hearing Loss Amongst Headphone Users

    PubMed Central

    Mazlan, R.; Saim, L.; Thomas, A.; Said, R.; Liyab, B.

    2002-01-01

    The use of headphone has been thought to cause infection in the ear canal and contribute to hearing loss. In this study, we examined 136 Customer Service Representative from Celcom (Malaysia) Sdn. Bhd. who use headphone throughout their working hours. The purpose of this study was to determine the prevalence of ear canal infection and other related diseases of the ear, nose and throat. Their hearing thresholds were also determined using the Amplaid 309 Clinical Audiometer. We found no incidence of infection of the external ear canal amongst the subjects. There were 4 cases of chronic middle ear infection and 4 cases of impacted wax. Hearing impairment was found in 25 subjects (21.2%). However, there was no significant association between hearing loss and the exposure to sound from headphone usage because the high frequencies were not predominantly affected. There was also no association between hearing loss and duration of service. PMID:22844220

  11. Recurrent syncope and chronic ear pain.

    PubMed

    Clegg, Andrew; Daverede, Luis; Wong, Winson; Loney, Elizabeth; Young, John

    2010-01-01

    An elderly gentleman presented to hospital with recurrent blackout episodes consistent with syncope and a 3-month history of right ear pain. Significant postural hypotension was recorded. White cell count and C reactive protein were elevated. MRI of the head and neck revealed a soft tissue abnormality in the right nasopharynx and base of skull. Tissue biopsies were obtained and microbiology specimens revealed a mixed growth of pseudomonas and diphtheroids. There was no histological evidence of malignancy. A diagnosis of skull base infection was made. Infective involvement of the carotid sinus was considered to be the cause of the recurrent syncope and postural hypotension. The patient responded well to a 12-week course of intravenous meropenem. Inflammatory markers returned to normal and a repeat MRI after 3 months of treatment showed significant resolution of infection. The syncopal episodes and orthostatic hypotension resolved in parallel with treatment of infection. PMID:22791782

  12. Clinical treatment of vascular inner ear diseases.

    PubMed

    Hultcrantz, E

    1988-01-01

    A multitude of general disorders of the vascular system may also affect the blood circulation of the cochlea and cause symptoms such as fluctuating or permanent hearing loss. Such is the case for arteriosclerosis combined with hypertension or hypotension, collagenosis, and diabetes. Blood disorders, like leukemia, sickle cell anemia, and polycythemia, and infectious diseases involving the blood vessels, such as lues, may also present their primary symptoms in the ear. The otorhinolaryngologist must be able to establish the correct diagnosis and refer patients requiring more general treatment to other specialists. The use of specific vasoactive treatment should be continued to those patients with symptoms of acute or fluctuating hearing loss, vertigo, or tinnitus who exhibit no other signs. Modern techniques for cochlear blood flow measurements have verified that several of the treatment protocols in use, which have a sound theoretical background, do indeed increase cochlear blood flow. PMID:3067594

  13. Analysis of Earing in Deep Drawn Cups

    SciTech Connect

    Aretz, Holger; Aegerter, Johannes; Engler, Olaf [Hydro Aluminium Deutschland GmbH, Research and Development, Georg-von-Boeselager-Str. 21, D-53117 Bonn (Germany)

    2010-06-15

    The cup-drawing of a strongly anisotropic sheet metal is simulated using a commercial finite element software along with a user material subroutine. In order to accurately describe the plastic anisotropy of the material the well-known recent yield function 'Yld2004-18p' is extended. Regarding the experimental characterization of the considered material the occurrence of dynamic strain aging lead to an oscillating signal of the width change of the tensile samples, which prevented a reliable determination of plastic strain ratios (r-values). Thus, an improved measurement concept was developed that leads to a very robust and reproducible determination of r-values. Furthermore, a novel plane-strain tensile test sample is presented which is used for the characterization of the plastic anisotropy in biaxial loading states. A quantitative comparison with measured earing profiles of deep drawn cups illustrates the predictive capabilities of the numerical simulation.

  14. Relapsing Polychondritis: Inflamed Joints and Ears

    PubMed Central

    Meliko?lu, Meltem Alkan; ?enel, Kaz?m

    2015-01-01

    Background: Relapsing polychondritis (RP) is an episodic and progressive inflammatory disease of the cartilaginous structures, including elastic cartilage of the ear and nose, hyaline cartilage of the peripheral joints, fibrocartilage at axial sites, and cartilage of the tracheo-bronchial tree. The spectrum of its presentations may vary from intermittent mild episodes of chondritis to occasional organ involvement or even life-threatening manifestations. Case Report: We presented a 64 year-old male patient with bilaterally knee arthritis and discoloration of pinna. Conclusion: There is lack of awareness about this disease due to its rarity. With this case presentation, our goal was to draw attention to this disease, which could be delayed for the diagnosis. PMID:25759785

  15. Tuberculosis of the ear, a professional disease?

    PubMed

    Sens, Patrícia Maria; Almeida, Clemente I R; Valle, Lupércio O do; Costa, Luís H C; Angeli, Miguel L S

    2008-01-01

    Tuberculosis is a rare cause of chronic suppurative otitis media and mastoiditis; the predisposing factors of this association, however, are not commonly described. There has been an alarming increase in the incidence of tuberculosis in Brazil, including tuberculous otitis media. These patients typically present multiple perforations of the tympanic membrane, an ear discharge, and progressive hearing loss. This diagnosis should be taken into account in patients that do not respond to routine therapy for fungal external otitis or bacterial otitis media. In this retrospective study, the authors describe four cases of patients with tuberculous otitis media. This sample consisted of two physicians, a chemical engineer and an underage child in whose family there were cases of active tuberculosis. Predisposing factors for tuberculous otitis were contact with family members that had tuberculosis, professional contact with patients and exposure to pathogenic microorganisms in airways. PMID:18852993

  16. Investigations of anti-inflammatory and antinociceptive activities of Piper cubeba, Physalis angulata and Rosa hybrida

    Microsoft Academic Search

    Eun-Mi Choi; Jae-Kwan Hwang

    2003-01-01

    The anti-inflammatory activities of Piper cubeba (fruit), Physalis angulata (flower) and Rosa hybrida (flower) were determined by carrageenan-induced paw edema, arachidonic acid-induced ear edema and formaldehyde-induced arthritis in mice. The anti-allergic and analgesic activities of these plants were also studied by using 2,4-dinitrofluorobenzene (DNFB)-induced contact hypersensitivity reaction (type IV) and hot plate test in mice, respectively. These plant extracts clearly

  17. Hydration-State Change of Horse Heart Cytochrome c Corresponding to Trifluoroacetic-Acid-Induced Unfolding

    PubMed Central

    Miyashita, Yusuke; Wazawa, Tetsuichi; Mogami, George; Takahashi, Satoshi; Sambongi, Yoshihiro; Suzuki, Makoto

    2013-01-01

    We investigate the hydration state of horse-heart cytochrome c (hh cyt c) in the unfolding process induced by trifluoroacetic acid (TFA). The conformation of hh cyt c changes from the native (N) state (2.9 < pH < 6.0) to the acid-unfolded (UA) state (1.7 < pH < 2.0) to the acid-induced molten globule (A) state (pH ?1.2). Hydration properties of hh cyt c during this process are measured at 20°C by high-resolution dielectric relaxation (DR) spectroscopy, UV-vis absorbance, and circular dichroism spectroscopy. Constrained water of hh cyt c is observed at every pH as an ?5-GHz Debye component (DC) (DR time, ?D ?30 ps) and its DR amplitude (DRA) is increased by 77% upon N-to-UA transition, when pH changes from 6.0 to 2.0. Even in the N state, the DRA of the constrained-water component is found to be increased by 22% with decreasing pH from 6.0 to 2.9, suggesting an increase in the accessible surface area of native hh cyt c. Moreover, hypermobile water around native hh cyt c is detected at pH 6.0 as a 19-GHz DC (?D ? 8.4 ps < ?DW = 9.4 ps), but is not found at other pH values. The DRA signal of constrained water is found to return to the pH 2.9 (N-state) level upon UA-to-A transition. Fast-response water (slightly slower than bulk) around A-state hh cyt c is detected at pH 1.2, and this suggests some accumulation of TFA? ions around the peptide chain. Thus, this high-resolution DR spectroscopy study reveals that hh cyt c exhibits significant hydration-state change in the TFA-unfolding process. PMID:23332069

  18. Characterization of retinoic acid-induced neurobehavioral effects in developing zebrafish.

    PubMed

    Wang, Yujiang; Chen, Jiangfei; Du, Changchun; Li, Chunqi; Huang, Changjiang; Dong, Qiaoxiang

    2014-02-01

    Retinoic signaling plays an important role in cell proliferation and differentiation. Disruption of retinoic signaling via excessive or deficient retinoic acid can cause teratogenic effects on developing embryos. Similar to retinoic acid, many xenobiotic environmental pollutants have been found to disrupt retinoic signaling through binding and eliciting agonistic activity on retinoic acid receptors. Currently, studies of retinoic acid or retinoic acid-like compounds in aquatic organisms have mainly focused on teratogenicity and few studies have explored their neurobehavioral toxicity. In the present study, the authors used retinoic acid as an example to explore the neurobehavioral toxicity associated with developmental exposure of retinoic acid-like compounds in zebrafish. The findings confirmed retinoic acid's teratogenic effects such as bent spine, malformed tail, and pericardial edema in developing zebrafish with a median effective concentration of 2.47 nM. Retinoic acid-induced cell apoptosis at 24?h postfertilization was consistently found in the eye and tail regions of embryos. Spontaneous movement as characterized by tail bend frequency was significantly increased in zebrafish embryos following exposure to 2 nM and 8 nM retinoic acid. Relatively low-dose retinoic acid exposure of 2 nM led to fast locomotion behavior in the dark period and hyperactivity during light-dark photoperiod stimulation. The 2-nM retinoic acid exposure also led to alterations of neurobehavior- and optic nerve-related genes, with the transforming growth factor-? signal transduction inhibitor noggin (nog) and the spinal cord marker homeobox c3a (hox) being underexpressed and the retinal G protein-coupled receptor a (rgr), the photoreceptor cell marker rhodopsin (rho), and the short wave-sensitive cone pigment opsin 1 (opn1sw1) being overexpressed. Increased expression of opn1sw1 and rho was confirmed by whole-mount in situ hybridization. Whether the misexpression of these genes leads to the neurobehavioral changes merits further study. The findings demonstrated that low-dose retinoic acid exposure perturbed the visual system and optic nerve development and caused hyperactivity in developing zebrafish. PMID:24395056

  19. Heterologous expression of a tannic acid-inducible laccase3 of Cryphonectria parasitica in Saccharomyces cerevisiae

    PubMed Central

    2010-01-01

    Background A tannic acid-inducible and mycoviral-regulated laccase3 (lac3) from the chestnut blight fungus Cryphonectria parasitica has recently been identified, but further characterization was hampered because of the precipitation of protein products by tannic acid supplementation. The present study investigated the heterologous expression of the functional laccase3 using a yeast Saccharomyces cerevisiae. Results Laccase activity in the culture broth of transformants measured using a laccase-specific substrate suggested that the lac3 gene was successfully expressed and the corresponding protein product secreted into the culture media. In addition, activity staining and Western blot analysis of a native gel revealed that the enzyme activity co-existed with the protein product specific to anti-laccase3 antibody, confirming that the cloned lac3 gene is responsible for the laccase activity. When transformants were grown on plates containing tannic acid-supplemented media, brown coloration was observed around transformed cells, indicating the oxidation of tannic acid. However, the enzymatic activity was measurable only in the selective ura- media and was negligible in nonselective nutrient-rich culture conditions. This was in part because of the increased plasmid instability in the nonselective media. Moreover, the protein product of lac3 appears to be sensitive to the cultured nonselective nutrient-rich broth, because a rapid decline in enzymatic activity was observed when the cultured broth of ura- media was mixed with that of nonselective nutrient-rich broth. In addition, constitutive expression of the lac3 gene resulted in a reduced cell number of the lac3 transformants compared to that of vector-only transformed control. However, the presence of recombinant vector without lac3 induction did not affect the growth of transformants. Conclusions The results suggest that expression of the lac3 gene has an inhibitory effect on the growth of transformed S. cerevisiae and that the controlled expression of lac3 is appropriate for the possible application of recombinant yeast to the treatment of phenolic compounds. PMID:20178646

  20. Combined Effect of Fluid and Pressure on Middle Ear Function

    PubMed Central

    Dai, Chenkai; Wood, Mark W.; Gan, Rong Z.

    2008-01-01

    In our previous studies, the effects of effusion and pressure on sound transmission were investigated separately. The aim of this study is to investigate the combined effect of fluid and pressure on middle ear function. An otitis media with effusion model was created by injecting saline solution and air pressure simultaneously into the middle ear of human temporal bones. Tympanic membrane displacement in response to 90 dB SPL sound input was measured by a laser vibrometer and the compliance of the middle ear was measured by a tympanometer. The movement of the tympanic membrane at the umbo was reduced up to 17 dB by the combination of fluid and pressure in the middle ear over the auditory frequency range. The fluid and pressure effects on the umbo movement in the fluid-pressure combination are not additive. The combined effect of fluid and pressure on the umbo movement is different compared with that of only fluid or pressure change in the middle ear. Negative pressure in fluid-pressure combination had more effect on middle ear function than positive pressure. Tympanometry can detect the middle ear pressure of the fluid-pressure combination. This study provides quantitative information for analysis of the combined effect of fluid and pressure on tympanic membrane movement. PMID:18162348

  1. Middle ear transmission in the grass frog, Rana temporaria.

    PubMed

    Jørgensen, M B; Kanneworff, M

    1998-01-01

    The anuran middle ear serves to transmit eardrum vibrations to the inner ear. In order to do this efficiently, the eardrum and middle ear must operate as an impedance transformer matching the low impedance of air to the higher impedance of the fluid-filled inner ear. In amniotes, one of the mechanisms used to achieve impedance transformation is to have the middle ear work as a force-amplifying lever system. Here, we present evidence that the grass frog middle ear also implements a lever system. The columellar footplate, which sits in the oval window, is firmly connected to the otic capsule along its ventral edge. Therefore, simple in-out movement of the columella is prevented while a rotational movement around the footplate's ventral edge is possible. The latter movement pattern was confirmed by laser vibrometry measurements of eardrum and footplate vibrations. The results showed that the footplate vibrations were 20-30 dB weaker than those of the eardrum and that the two structures vibrated 180 degrees out of phase (at low frequencies). The lever ratio was approximately 6, i.e. somewhat higher than lever ratios reported for amniotes. Hence, the middle ear lever probably makes a significant contribution to impedance matching in frogs. PMID:9447714

  2. Cells, molecules and morphogenesis: The making of the vertebrate ear

    PubMed Central

    Fritzsch, Bernd; Pauley, Sarah; Beisel, Kirk W.

    2014-01-01

    The development and evolution of mechanosensory cells and the vertebrate ear is reviewed with an emphasis on delineating the cellular, molecular and developmental basis of these changes. Outgroup comparisons suggests that mechanosensory cells are ancient features of multicellular organisms. Molecular evidence suggests that key genes involved in mechanosensory cell function and development are also conserved among metazoans. The divergent morphology of mechanosensory cells across phyla is interpreted here as ‘deep molecular homology’ that was in parallel shaped into different forms in each lineage. The vertebrate mechanosensory hair cell and its associated neuron are interpreted as uniquely derived features of vertebrates. It is proposed that the vertebrate otic placode presents a unique embryonic adaptation in which the diffusely distributed ancestral mechanosensory cells became concentrated to generate a large neurosensory precursor population. Morphogenesis of the inner ear is reviewed and shown to depend on genes expressed in and around the hindbrain that interact with the otic placode to define boundaries and polarities. These patterning genes affect downstream genes needed to maintain proliferation and to execute ear morphogenesis. We propose that fibroblast growth factors (FGFs) and their receptors (FGFRs) are a crucial central node to translate patterning into the complex morphology of the vertebrate ear. Unfortunately, the FGF and FGFR genes have not been fully analyzed in the many mutants with morphogenetic ear defects described thus far. Likewise, little information exists on the ear histogenesis and neurogenesis in many mutants. Nevertheless, a molecular mechanism is now emerging for the formation of the horizontal canal, an evolutionary novelty of the gnathostome ear. The existing general module mediating vertical canal growth and morphogenesis was modified by two sets of new genes: one set responsible for horizontal canal morphogenesis and another set for neurosensory formation of the horizontal crista and associated sensory neurons. The dramatic progress in deciphering the molecular basis of ear morphogenesis offers grounds for optimism for translational research toward intervention in human morphogenetic defects of the ear. PMID:16643865

  3. Microsurgical replantation of a partial helix of the ear.

    PubMed

    Kim, Kwang Seog; Kim, Eui Sik; Hwang, Jae Ha; Lee, Sam Yong

    2009-01-01

    Microsurgical ear replantation is a significant challenge because vessel sizes are diminutive. Furthermore, as ear vessels are larger in the medial portion than in the lateral portion, microsurgical replantation of a replant including only the helix is extremely difficult. The authors replanted a partial helix of the ear using a single arterial anastomosis. As no suitable veins could be identified, medicinal leech therapy and systemic heparinization were used to achieve venous drainage. The replanted helix survived completely and the cosmetic result was excellent. Microsurgical replantation should be considered the treatment of choice in helix amputation cases, even though amount of replant is small. (c) 2009 Wiley-Liss, Inc. Microsurgery 2009. PMID:19306389

  4. Shaping sound in space: the regulation of inner ear patterning

    PubMed Central

    Groves, Andrew K.; Fekete, Donna M.

    2012-01-01

    The inner ear is one of the most morphologically elaborate tissues in vertebrates, containing a group of mechanosensitive sensory organs that mediate hearing and balance. These organs are arranged precisely in space and contain intricately patterned sensory epithelia. Here, we review recent studies of inner ear development and patterning which reveal that multiple stages of ear development – ranging from its early induction from the embryonic ectoderm to the establishment of the three cardinal axes and the fine-grained arrangement of sensory cells – are orchestrated by gradients of signaling molecules. PMID:22186725

  5. Increase of [Ca(2+)]i and release of arachidonic acid via activation of M2 receptor coupled to Gi and rho proteins in oesophageal muscle.

    PubMed

    Sohn, U D; Hong, Y W; Choi, H C; Ha, J H; Lee, K Y; Kim, W J; Biancani, P; Jeong, J H; Huh, I H

    2000-04-01

    We have previously shown that acetylcholine-induced contraction of oesophageal circular muscle depends on activation of phosphatidylcholine selective phospholipase C and D, which result in formation of diacylglycerol, and of phospholipase 2 which produces arachidonic acid. Diacylglycerol and arachidonic acid interact synergistically to activate protein kinase C. We have therefore investigated the relationship between cytosolic Ca(2+) and activation of phospholipase A(2) in response to acetylcholine-induced stimulation, by measuring the intracellular free Ca(2+) ([Ca(2+)]i), muscle tension, and [3H] arachidonic acid release. Acetylcholine-induced contraction was associated with increased [Ca(2+)]i and arachidonic acid release in a dose-dependent manner. In Ca(2+)-free medium, acetylcholine did not produce contraction, [Ca(2+)]i increase, and arachidonic acid release. In contrast, after depletion of Ca(2+) stores by thapsigargin (3 microM), acetylcholine caused a normal contraction, [Ca(2+)]i increase and arachidonic acid release. The increase in [Ca(2+)]i and arachidonic acid release were attenuated by the M2 receptor antagonist methoctramine, but not by the M3 receptor antagonist p-fluoro-hexahydro siladifenidol. Increase in [Ca(2+)]i and arachidonic acid release by acetylcholine were inhibited by pertussis toxin and C3 toxin. These findings indicate that contraction and arachidonic acid release are mediated through muscarinic M2 coupled to Gi or rho protein activation and Ca(2+) influx. Acetylcholine-induced contraction and the associated increase in [Ca(2+)]i and release of arachidonic acid were completely reduced by the combination treatment with a phospholipase A(2) inhibitor dimethyleicosadienoic acid and a phospholipase D inhibitor pCMB. They increased by the action of the inhibitor of diacylglycerol kinase R59949, whereas they decreased by a protein kinase C inhibitor chelerythrine. These data suggest that in oesophageal circular muscle acetylcholine-induced [Ca(2+)]i increase and arachidonic acid release are mediated through activation of M2 receptor coupled to Gi or rho protein, resulting in the activation of phospholipase A(2) and phospholipase D to activate protein kinase C. PMID:10781928

  6. Group IV cytosolic phospholipase A 2 mediates arachidonic acid release in H9c2 rat cardiomyocyte cells in response to hydrogen peroxide

    Microsoft Academic Search

    Michelle V. Winstead; Karin Killermann Lucas; Edward A. Dennis

    2005-01-01

    Damaging reactive oxygen species are released during episodes of ischemia and reperfusion. Some cellular adaptive responses are triggered to protect the injured organ, while other cascades are triggered which potentiate the damage. In these studies, we demonstrate that rat cardiomyocte H9c2 cells release arachidonic acid in response to hydrogen peroxide. In H9c2 cells, arachidonic acid release is attenuated by methyl

  7. Expression of the bile acid-inducible NADH:flavin oxidoreductase gene of Eubacterium sp. VPI 12708 in Escherichia coli

    Microsoft Academic Search

    Stephen F. Baron; Phillip B. Hylemon

    1995-01-01

    The intestinal microorganism Eubacterium sp. VPI 12708 synthesizes a bile acid-inducible NADH:flavin oxidoreductase (NADH:FOR) which presumably functions in the 7?-dehydroxylation of cholic acid to deoxycholic acid. The baiH gene encoding NADH:FOR was subcloned into an IPTG-inducible expression vector, pBaiH2.2. Escherichia coli DH5? cells transformed with pBaiH2.2 expressed 10-fold higher levels of NADH:.FOR upon induction with IPTG than did Eubacterium sp.

  8. Comparison of acid-induced inflammatory responses in the rat lung during high frequency oscillatory and conventional mechanical ventilation

    Microsoft Academic Search

    Ming-Yuan Jian; Tomonobu Koizumi; Toshiki Yokoyama; Kenji Tsushima; Keishi Kubo

    2010-01-01

    Background  The present study was performed to compare the effects of high frequency oscillatory ventilation (HFOV) with conventional\\u000a mechanical ventilation (CMV) on pulmonary inflammatory responses in a rat acid-induced lung injury model.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Anesthetized rats were instilled intratracheally with HCl (0.1 N, 2 mL\\/kg) and then randomly divided into three mechanical\\u000a ventilation settings: HFOV (an oscillatory frequency of 15 Hz, mean airway pressure (MAP) of

  9. 2-Hydroxy Arachidonic Acid: A New Non-Steroidal Anti-Inflammatory Drug

    PubMed Central

    Lopez, Daniel H.; Fiol-deRoque, Maria A.; Noguera-Salvà, Maria A.; Terés, Silvia; Campana, Federica; Piotto, Stefano; Castro, José A.; Mohaibes, Raheem J.; Escribá, Pablo V.; Busquets, Xavier

    2013-01-01

    Background Nonsteroidal anti-inflammatory drugs (NSAIDs) are a family of COX1 and COX2 inhibitors used to reduce the synthesis of pro-inflammatory mediators. In addition, inflammation often leads to a harmful generation of nitric oxide. Efforts are being done in discovering safer NSAIDs molecules capable of inhibiting the synthesis of pro-inflammatory lipid mediators and nitric oxide to reduce the side effects associated with long term therapies. Methodology/Principal Findings The analogue of arachidonic acid (AA), 2-hydroxy-arachidonic acid (2OAA), was designed to inhibit the activities of COX1 and COX2 and it was predicted to have similar binding energies as AA for the catalytic sites of COX1 and COX2. The interaction of AA and 2OAA with COX1 and COX2 was investigated calculating the free energy of binding and the Fukui function. Toxicity was determined in mouse microglial BV-2 cells. COX1 and COX2 (PGH2 production) activities were measured in vitro. COX1 and COX2 expression in human macrophage-like U937 cells were carried out by Western blot, immunocytochemistry and RT-PCR analysis. NO production (Griess method) and iNOS (Western blot) were determined in mouse microglial BV-2 cells. The comparative efficacy of 2OAA, ibuprofen and cortisone in lowering TNF-? serum levels was determined in C57BL6/J mice challenged with LPS. We show that the presence of the –OH group reduces the likelihood of 2OAA being subjected to H* abstraction in COX, without altering significantly the free energy of binding. The 2OAA inhibited COX1 and COX2 activities and the expression of COX2 in human U937 derived macrophages challenged with LPS. In addition, 2OAA inhibited iNOS expression and the production of NO in BV-2 microglial cells. Finally, oral administration of 2OAA decreased the plasma TNF-? levels in vivo. Conclusion/Significance These findings demonstrate the potential of 2OAA as a NSAID. PMID:24015204

  10. Secular trend of serum docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid concentrations among Japanese-a 4- and 13-year descriptive epidemiologic study.

    PubMed

    Otsuka, Rei; Kato, Yuki; Imai, Tomoko; Ando, Fujiko; Shimokata, Hiroshi

    2015-03-01

    Cross-sectional studies have shown age-related increases in blood docosahexaenoic and eicosapentaenoic acid and decreases in arachidonic acid. We describe serum docosahexaenoic, eicosapentaenoic, and arachidonic acid concentrations over 13 years (1997-2012) across four study waves and serum fatty acid composition over 4 years (2006-2012) between two study waves according to age groups by sex in the same subjects. We included 443 men and 435 women aged 40-79 years at baseline. Serum arachidonic acid concentrations increased in all sex and age groups over 13 years, and eicosapentaenoic or docosahexaenoic acid concentrations increased in males and females who were younger and middle-aged at baseline. Only serum arachidonic acid composition increased over 4 years in men and women who were 40-69 years at baseline, even after adjustment for arachidonic acid intake. These findings suggest a secular increase trend in serum arachidonic acid levels over 13 years among randomly selected community-dwelling middle-aged and elderly Japanese. PMID:25441967

  11. Ceramide-Activated Phosphatase Mediates Fatty Acid–Induced Endothelial VEGF Resistance and Impaired Angiogenesis

    PubMed Central

    Mehra, Vishal C.; Jackson, Elias; Zhang, Xian M.; Jiang, Xian-Cheng; Dobrucki, Lawrence W.; Yu, Jun; Bernatchez, Pascal; Sinusas, Albert J.; Shulman, Gerald I.; Sessa, William C.; Yarovinsky, Timur O.; Bender, Jeffrey R.

    2014-01-01

    Endothelial dysfunction, including endothelial hyporesponsiveness to prototypical angiogenic growth factors and eNOS agonists, underlies vascular pathology in many dysmetabolic states. We investigated effects of a saturated free fatty acid, palmitic acid (PA), on endothelial cell responses to VEGF. PA-pretreated endothelial cells had markedly diminished Akt, eNOS, and ERK activation responses to VEGF, despite normal VEGFR2 phosphorylation. PA inhibited VEGF-induced angiogenic cord formation in Matrigel, and PA-treated endothelial cells accumulated early species (C16) ceramide. The serine palmitoyltransferase inhibitor myriocin reversed these defects. Protein phosphatase 2A (PP2A) became more eNOS-associated in PA-treated cells; the PP2A inhibitor okadaic acid reversed PA-induced signaling defects. Mice fed a diet high in saturated fat for 2 to 3 weeks had impaired i) aortic Akt and eNOS phosphorylation to infused VEGF, ii) ear angiogenic responses to intradermal adenoviral-VEGF injection, and iii) vascular flow recovery to hindlimb ischemia as indicated by laser Doppler and ?V?3 SPECT imaging. High-fat feeding did not impair VEGF-induced signaling or angiogenic responses in mice with reduced serine palmitoyltransferase expression. Thus, de novo ceramide synthesis is required for these detrimental PA effects. The findings demonstrate an endothelial VEGF resistance mechanism conferred by PA, which comprises ceramide-induced, PP2A-mediated dephosphorylation of critical activation sites on enzymes central to vascular homeostasis and angiogenesis. This study defines potential molecular targets for preservation of endothelial function in metabolic syndrome. PMID:24606881

  12. Kinetic Modulation of Kv4-Mediated A-Current by Arachidonic Acid Is Dependent on Potassium Channel Interacting Proteins

    Microsoft Academic Search

    Mats H. Holmqvist; Jie Cao; Maria H. Knoppers; Mark E. Jurman; Peter S. Distefano; Kenneth J. Rhodes; Yu Xie; W. Frank An

    2001-01-01

    The Kv4 subfamily of voltage-gated potassium channels is responsible for the transient A-type potassium current that operates at subthreshold membrane potentials to control mem- brane excitability. Arachidonic acid was shown recently to modulate both the peak amplitude and kinetics of the hip- pocampal A-current. However, in Xenopus oocytes, arachi- donic acid only inhibited the peak amplitude of Kv4 current without

  13. Chronic Carbamazepine Administration Attenuates Dopamine D 2 -like Receptor-Initiated Signaling via Arachidonic Acid in Rat Brain

    Microsoft Academic Search

    Mireille Basselin; Lisa Chang; Mei Chen; Jane M. Bell; Stanley I. Rapoport

    2008-01-01

    Observations that dopaminergic antagonists are beneficial in bipolar disorder and that dopaminergic agonists can produce mania\\u000a suggest that bipolar disorder involves excessive dopaminergic transmission. Thus, mood stabilizers used to treat the disease\\u000a might act in part by downregulating dopaminergic transmission. In agreement, we reported that dopamine D2-like receptor mediated signaling involving arachidonic acid (AA, 20:4n?6) was downregulated in rats chronically

  14. The effect of dietary arachidonic acid on platelet function, platelet fatty acid composition, and blood coagulation in humans

    Microsoft Academic Search

    G. J. Nelson; P. C. Schmidt; G. Bartolini; D. S. Kelley; David Kyle

    1997-01-01

    Arachidonic acid (AA) is the precursor of thromboxane and prostacyclin, two of the most active compounds related to platelet\\u000a function. The effect of dietary AA on platelet function in humans is not understood although a previous study suggested dietary\\u000a AA might have adverse physiological consequences on platelet function. Here normal healthy male volunteers (n=10) were fed diets containing 1.7 g\\/d

  15. Arachidonic acid inhibits lipogenic gene expression in 3T3-L1 adipocytes through a prostanoid pathway

    Microsoft Academic Search

    Michelle K. Mater; David Pan; W. G. Bergen; Donald B. Jump

    This report examines the effect of polyunsatu- rated fatty acids (PUFA) on lipogenic gene expression in cultured 3T3-L1 adipocytes. Arachidonic acid (20:4, n-6) and eicosapentaenoic acid (20:5, n-3) suppressed mRNAs encoding fatty acid synthase (FAS) and S14, but had no ef- fect on b -actin. Using a clonal adipocyte cell line containing a stably integrated S14CAT fusion gene, oleic acid

  16. Modulation of the activity and arachidonic acid selectivity of group X secretory phospholipase A2 by sphingolipids

    Microsoft Academic Search

    Dev K. Singh; Papasani V. Subbaiah

    2006-01-01

    To investigate the role of sphingomyelin (SM) in the regulation of inflammatory reactions, we studied its effect on the activity and fatty acid specificity of group X secretory phospholipase A2 (sPLA2X). Compared with other phospholipases, recombinant sPLA2X released more ara- chidonate from HDL. Pretreatment of HDL with sphin- gomyelinase (SMase) C activated the sPLA2X activity, but the release of arachidonate

  17. Diets rich in lean beef increase arachidonic acid and long-chain ?3 polyunsaturated fatty acid levels in plasma phospholipids

    Microsoft Academic Search

    Andrew J. Sinclair; Leeann Johnson; Kerin O'Dea; Ralph T. Holman

    1994-01-01

    Diets rich in meat are claimed to contribute to the high tissue arachidonic acid (20?4?6) content in people in Westernized\\u000a societies, but there are very few direct data to substantiate this assertion. Because meat contains a variety of long-chain\\u000a polyunsaturated fatty acids (PUFA) that are susceptible to oxidation, we initially examined the effect of cooking on the long-chain\\u000a PUFA content

  18. Partial purification from macrophages of a phospholipase A/sub 2/ that hydrolyzes arachidonic acid from phosphatidylcholine

    SciTech Connect

    Leslie, C.; Wall, M.; Zelarney, P.; Voelker, D.

    1987-05-01

    The first step in platelet-activating factor production and arachidonic acid release from stimulated inflammatory cells is thought to be the activation of a phospholipase A/sub 2/ (PLA/sub 2/). The mouse macrophage cell line, RAW 264, was found to contain PLA/sub 2/ activity that hydrolyzed /sup 3/H-arachidonic acid from sonicated dispersions of 1-0-alkyl-linked phosphatidylcholine (PC). The PLA/sub 2/ was cytosolic, required calcium, and exhibited a broad pH optimum between 6 and 10. When the hydrolysis of /sup 3/H-arachidonic acid from 1-palmitoyl- and 1-hexadecyl-linked PC (15 ..mu..M) was compared, slightly higher activity against 1-acyl-linked PC was found. However, the activity against 1-palmitoyl-linked PC substrates containing oleic or linoleic acids (sn-2) was considerably lower. To understand the properties of the PLA/sub 2/ in more detail, purification was undertaken. After ammonium sulfate precipitation the PLA/sub 2/ was fractionated over G150, on which it eluted slightly before an albumin marker. The enzyme bound to DEAE cellulose at pH 8.0 and was eluted in 0.3M NaCl. Further purification was achieved by hydrophobic chromatography over phenyl Sepharose followed by ion-exchange chromatography using Q-Sepharose resulting in 200-700-fold increases in specific activity. These results demonstrate the presence of a cytosolic PLA/sub 2/ in macrophages that shows specificity for arachidonic acid at the sn-2 position of PC, has an apparent molecular weight greater than or equal to albumin, is anionic at pH 8.0 and is relatively hydrophobic.

  19. Improved Cognitive Development Among Preterm Infants Attributable to Early Supplementation of Human Milk With Docosahexaenoic Acid and Arachidonic Acid

    Microsoft Academic Search

    Christine Henriksen; Kristin Haugholt; Magnus Lindgren; Anne Karin; Morten Grønn; Atle Moen; Britt Nakstad; Rolf Kristian Berge; Lars Smith; Ole Iversen; Christian AndreDrevon

    OBJECTIVE.The objective of our study was to evaluate the effect of supplementation with docosahexaenoic acid and arachidonic acid for human milk-fed preterm infants. The primary end point was cognitive development at 6 months of age. METHODS.The study was a randomized, double-blind, placebo-controlled study among 141 infants with birth weights of 1500 g. The intervention with 32 mg of docosa- hexaenoic

  20. Green laser light activates the inner ear.

    PubMed

    Wenzel, Gentiana I; Balster, Sven; Zhang, Kaiyin; Lim, Hubert H; Reich, Uta; Massow, Ole; Lubatschowski, Holger; Ertmer, Wolfgang; Lenarz, Thomas; Reuter, Guenter

    2009-01-01

    The hearing performance with conventional hearing aids and cochlear implants is dramatically reduced in noisy environments and for sounds more complex than speech (e. g. music), partially due to the lack of localized sensorineural activation across different frequency regions with these devices. Laser light can be focused in a controlled manner and may provide more localized activation of the inner ear, the cochlea. We sought to assess whether visible light with parameters that could induce an optoacoustic effect (532 nm, 10-ns pulses) would activate the cochlea. Auditory brainstem responses (ABRs) were recorded preoperatively in anesthetized guinea pigs to confirm normal hearing. After opening the bulla, a 50-microm core-diameter optical fiber was positioned in the round window niche and directed toward the basilar membrane. Optically induced ABRs (OABRs), similar in shape to those of acoustic stimulation, were elicited with single pulses. The OABR peaks increased with energy level (0.6 to 23 microJ/pulse) and remained consistent even after 30 minutes of continuous stimulation at 13 microJ, indicating minimal or no stimulation-induced damage within the cochlea. Our findings demonstrate that visible light can effectively and reliably activate the cochlea without any apparent damage. Further studies are in progress to investigate the frequency-specific nature and mechanism of green light cochlear activation. PMID:19725719

  1. Why Internally Coupled Ears (ICE) Work Well

    NASA Astrophysics Data System (ADS)

    van Hemmen, J. Leo

    2014-03-01

    Many vertebrates, such as frogs and lizards, have an air-filled cavity between left and right eardrum, i.e., internally coupled ears (ICE). Depending on source direction, internal time (iTD) and level (iLD) difference as experienced by the animal's auditory system may greatly exceed [C. Vossen et al., JASA 128 (2010) 909-918] the external, or interaural, time and level difference (ITD and ILD). Sensory processing only encodes iTD and iLD. We present an extension of ICE theory so as to elucidate the underlying physics. First, the membrane properties of the eardrum explain why for low frequencies iTD dominates whereas iLD does so for higher frequencies. Second, the plateau of iTD = ? ITD for constant 1 < ? < 5 and variable input frequency

  2. Image analysis of the human inner ear.

    PubMed

    Kubo, T; Anniko, M; Hsu, W J

    1998-01-01

    The KS 300 is a multifunctional software image analysis system using an object-oriented programming environment. The possibility of its application for the inner ear was studied by using specimens from humans and squirrel monkeys, immunostained for the brain-derived calcium-binding protein, S-100 protein. Grey images were used for measurements. The cell borders were outlined by hand, using a digitizer. The absolute grey values of the pixels changed when the brightness of the images or other conditions changed. By contrast, the relative grey values, i.e. the absolute grey values correlated to the mean grey values of the histoimage, remained constant. By utilizing these relative grey values, it was possible to compare cells both between different specimens and between different areas within the same specimen. The different grey values of spiral ganglion cells stained for S-100 protein are objective quantitative measurements and are believed to reflect differences in their function. In some regions of both human and squirrel monkey specimens, relatively intensely stained cells predominated, whereas in other regions, relatively weakly stained cells were mainly observed. Thus, our image analysis system using the relative grey values has proved suitable for quantitative analysis of immunostained specimens in order to compare them and to assess cell function. PMID:9504164

  3. How minute sooglossid frogs hear without a middle ear.

    PubMed

    Boistel, Renaud; Aubin, Thierry; Cloetens, Peter; Peyrin, Françoise; Scotti, Thierry; Herzog, Philippe; Gerlach, Justin; Pollet, Nicolas; Aubry, Jean-François

    2013-09-17

    Acoustic communication is widespread in animals. According to the sensory drive hypothesis [Endler JA (1993) Philos Trans R Soc Lond B Biol Sci 340(1292):215-225], communication signals and perceptual systems have coevolved. A clear illustration of this is the evolution of the tetrapod middle ear, adapted to life on land. Here we report the discovery of a bone conduction-mediated stimulation of the ear by wave propagation in Sechellophryne gardineri, one of the world's smallest terrestrial tetrapods, which lacks a middle ear yet produces acoustic signals. Based on X-ray synchrotron holotomography, we measured the biomechanical properties of the otic tissues and modeled the acoustic propagation. Our models show how bone conduction enhanced by the resonating role of the mouth allows these seemingly deaf frogs to communicate effectively without a middle ear. PMID:24003145

  4. Making an Effort to Listen: Mechanical Amplification in the Ear

    PubMed Central

    Hudspeth, A. J.

    2009-01-01

    The inner ear’s performance is greatly enhanced by an active process defined by four features: amplification, frequency selectivity, compressive nonlinearity, and spontaneous otoacoustic emission. These characteristics emerge naturally if the mechanoelectrical transduction process operates near a dynamical instability, the Hopf bifurcation, whose mathematical properties account for specific aspects of our hearing. The active process of non-mammalian tetrapods depends upon active hair-bundle motility, which emerges from the interaction of negative hair-bundle stiffness and myosin-based adaptation motors. Taken together, these phenomena explain the four characteristics of the ear’s active process. In the high-frequency region of the mammalian cochlea, the active process is dominated instead by the phenomenon of electromotility, in which the cell bodies of outer hair cells extend and contract as the protein prestin alters its membrane surface area in response to changes in membrane potential. PMID:18760690

  5. What have lizard ears taught us about auditory physiology?

    PubMed

    Manley, Geoffrey A; Köppl, Christine

    2008-04-01

    The structure of the basilar papilla of the inner ear of lizards is the most diverse among all vertebrates. Research on a variety of lizard ears, animals that are remarkably robust under laboratory conditions, has provided the field of auditory research with valuable information, particularly on the minimum structural requirements for sensitive, selective hearing and on the importance of the tectorial membrane and active processes in this regard. Despite the absence of a tuned basilar membrane, lizard ears produce highly frequency selective hearing through micromechanical tuning of small, resonant hair-cell-tectorial units or of free-standing hair bundles. These units are driven by an active process that also underlies spontaneous and other otoacoustic emissions. Lizard ears provided the first in vivo evidence that the active process is calcium-sensitive and lies within the stereovillar bundles of the hair cells. PMID:17983712

  6. Arachidonic acid metabolites do not mediate modulation of neurotransmitter release by adenosine in rat hippocampus or striatum.

    PubMed

    Dunwiddie, T V; Taylor, M; Cass, W A; Fitzpatrick, F A; Zahniser, N R

    1990-09-10

    The possible involvement of arachidonic acid metabolites as mediators of the modulation of neurotransmitter release by adenosine, acetylcholine, and GABA was examined in brain slices of rat hippocampus and striatum. The synaptic modulatory effects of these 3 agents on excitatory transmission in the CA1 region of hippocampus were completely unaffected by a phospholipase inhibitor (p-bromophenacyl bromide, BPB; 10-50 microM), a lipoxygenase inhibitor (nordihydroguaiaretic acid; 5-50 microM), the cyclooxygenase inhibitor indomethacin (10-20 microM), and a cyclooxygenase/lipoxygenase inhibitor (U53059; 5-10 microM). BPB was also found to be ineffective in altering the modulation of transmission by adenosine in the perforant path, and the adenosine inhibition of electrically stimulated release of endogenous dopamine from striatal slices. Arachidonic acid itself also had no effect on synaptic transmission. While these experiments do not rule out such a role for arachidonic acid or its metabolites in mammalian brain, they suggest that in a number of systems the inhibition of transmitter release must occur through an entirely independent mechanism. PMID:1980842

  7. Wideband Power Reflectance and Power Transmittance as Tools for Assessing Middle-Ear Function

    E-print Network

    Allen, Jont

    44 Wideband Power Reflectance and Power Transmittance as Tools for Assessing Middle-Ear Function using otoacoustic emissions can have high false positive rates, due to temporary middle-ear and outer-ear is limited, uncomfortable, and unreliable in young ears. By incorporating wideband acoustic power flow

  8. Plant physiology Role of awns in ear water-use efficiency

    E-print Network

    Paris-Sud XI, Université de

    Plant physiology Role of awns in ear water-use efficiency and grain weight in barley J Bort net photosynthesis and water-use efficiency (WUE: net photosynthesis/transpiration) of ears and flag photosynthesis of awned ears was markedly higher than that of awnless ears, until 3 weeks after anthesis

  9. Prediction of the sound pressure at the ear drum for open fittings

    E-print Network

    Paris-Sud XI, Université de

    Prediction of the sound pressure at the ear drum for open fittings T. Sankowsky-Rothea , M. Blaua of hearing aids requires knowledge of the sound pressure generated at the ear drum. Traditionally, the sound pressure at the ear drum is estimated by the use of a model of an average ear canal (e.g. a coupler

  10. Reflectance in ME disorders 1 Running head: REFLECTANCE IN MIDDLE-EAR DISORDERS

    E-print Network

    Allen, Jont

    Reflectance in ME disorders 1 Running head: REFLECTANCE IN MIDDLE-EAR DISORDERS Wideband energy reflectance measurements in adults with middle-ear disorders M. Patrick Feeney University of Washington with a variety of middle-ear disorders. The ER results from nine participants with middle-ear disorders and one

  11. ON A MATROID DEFINED BY EAR-DECOMPOSITIONS OF GRAPHS ZOLTAN SZIGETI *

    E-print Network

    Szigeti, Zoltán

    ON A MATROID DEFINED BY EAR-DECOMPOSITIONS OF GRAPHS ZOLT´AN SZIGETI * December 1, 1995 A-edge­connected graphs this value equals the minimum number (G) of even ears in ear­decompositions of G that G is 2-edge­ connected. Let G = (V, E) be an undirected, 2-edge­connected graph. An ear

  12. Q What is a unilateral hearing loss? What causes a hearing loss in only one ear?

    E-print Network

    O'Toole, Alice J.

    Q· What is a unilateral hearing loss? · What causes a hearing loss in only one ear? · Will the hearing in my child's better ear get worse? · Why would my child have trouble hearing if one ear has normal hearing? · Will my child benefit from wearing a hearing aid in the ear with the hearing loss

  13. Wideband energy reflectance measurements: Effects of negative middle ear pressure and application of a pressure compensation

    E-print Network

    Allen, Jont

    Wideband energy reflectance measurements: Effects of negative middle ear pressure and application become popular as a tool for evaluating mid- dle ear function. Negative middle ear pressure (MEP) is a prevalent form of middle ear dysfunction, which may impact application of ER measurements in differential

  14. Sonographic Measurement of Fetal Ear Length in Turkish Women with a Normal Pregnancy

    PubMed Central

    Özdemir, Mucize Eriç; Uzun, I??l; Karahasano?lu, Ay?e; Aygün, Mehmet; Ak?n, Hale; Yaz?c?o?lu, Fehmi

    2014-01-01

    Background: Abnormal fetal ear length is a feature of chromosomal disorders. Fetal ear length measurement is a simple measurement that can be obtained during ultrasonographic examinations. Aims: To develop a nomogram for fetal ear length measurements in our population and investigate the correlation between fetal ear length, gestational age, and other standard fetal biometric measurements. Study Design: Cohort study. Methods: Ear lengths of the fetuses were measured in normal singleton pregnancies. The relationship between gestational age and fetal ear length in millimetres was analysed by simple linear regression. In addition, the correlation of fetal ear length measurements with biparietal diameter, head circumference, abdominal circumference, and femur length were evaluated.Ear length measurements were obtained from fetuses in 389 normal singleton pregnancies ranging between 16 and 28 weeks of gestation. Results: A nomogram was developed by linear regression analysis of the parameters ear length and gestational age. Fetal ear length (mm) = y = (1.348 X gestational age)?12.265), where gestational ages is in weeks. A high correlation was found between fetal ear length and gestational age, and a significant correlation was also found between fetal ear length and the biparietal diameter (r=0.962; p<0.001). Similar correlations were found between fetal ear length and head circumference, and fetal ear length and femur length. Conclusion: The results of this study provide a nomogram for fetal ear length. The study also demonstrates the relationship between ear length and other biometric measurements. PMID:25667783

  15. Ear decomposition of 3-regular polyhedral links with applications.

    PubMed

    Cheng, Xiao-Sheng; Zhang, Heping; Jin, Xian'an; Qiu, Wen-Yuan

    2014-10-21

    In this paper, we introduce a notion of ear decomposition of 3-regular polyhedral links based on the ear decomposition of the 3-regular polyhedral graphs. As a result, we obtain an upper bound for the braid index of 3-regular polyhedral links. Our results may be used to characterize and analyze the structure and complexity of protein polyhedra and entanglement in biopolymers. PMID:24952099

  16. Allicin alleviates inflammation of trinitrobenzenesulfonic acid-induced rats and suppresses P38 and JNK pathways in Caco-2 cells.

    PubMed

    Li, Chen; Lun, Weijian; Zhao, Xinmei; Lei, Shan; Guo, Yandong; Ma, Jiayi; Zhi, Fachao

    2015-01-01

    Background. Allicin has anti-inflammatory, antioxidative and proapoptotic properties. Aims. To evaluate the effects and investigate the mechanism of allicin on trinitrobenzenesulfonic acid-induced colitis, specifically with mesalazine or sulfasalazine. Methods. 80 rats were divided equally into 8 groups: control; trinitrobenzenesulfonic acid; allicin prevention; allicin; mesalazine; sulfasalazine; allicin + sulfasalazine, and mesalazine + allicin. Systemic and colonic inflammation parameters were analysed. In addition, protein and culture medium of Caco-2 cells treated with various concentrations of IL-1? or allicin were collected for investigation of IL-8, NF-?B p65 P38, ERK, and JNK. One-way ANOVA and Kruskal-Wallis H test were used for parametric and nonparametric tests, respectively. Results. Allicin reduced the body weight loss of trinitrobenzenesulfonic acid-induced rats, histological score, serum TNF-? and IL-1? levels, and colon IL-1? mRNA level and induced serum IL-4 level, particularly in combination with mesalazine. In addition, 1?ng/mL IL-1? stimulated the P38, ERK, and JNK pathways, whereas pretreatment with allicin depressed this phenomenon, except for the ERK pathway. Conclusions. The inflammation induced by trinitrobenzenesulfonic acid is mitigated significantly by allicin treatment, particularly combined with mesalazine. Allicin inhibits the P38 and JNK pathways and the expression of NF-?B which explained the potential anti-inflammatory mechanisms of allicin. PMID:25729217

  17. Allicin Alleviates Inflammation of Trinitrobenzenesulfonic Acid-Induced Rats and Suppresses P38 and JNK Pathways in Caco-2 Cells

    PubMed Central

    Li, Chen; Lun, Weijian; Zhao, Xinmei; Lei, Shan; Guo, Yandong; Ma, Jiayi

    2015-01-01

    Background. Allicin has anti-inflammatory, antioxidative and proapoptotic properties. Aims. To evaluate the effects and investigate the mechanism of allicin on trinitrobenzenesulfonic acid-induced colitis, specifically with mesalazine or sulfasalazine. Methods. 80 rats were divided equally into 8 groups: control; trinitrobenzenesulfonic acid; allicin prevention; allicin; mesalazine; sulfasalazine; allicin + sulfasalazine, and mesalazine + allicin. Systemic and colonic inflammation parameters were analysed. In addition, protein and culture medium of Caco-2 cells treated with various concentrations of IL-1? or allicin were collected for investigation of IL-8, NF-?B p65 P38, ERK, and JNK. One-way ANOVA and Kruskal-Wallis H test were used for parametric and nonparametric tests, respectively. Results. Allicin reduced the body weight loss of trinitrobenzenesulfonic acid-induced rats, histological score, serum TNF-? and IL-1? levels, and colon IL-1? mRNA level and induced serum IL-4 level, particularly in combination with mesalazine. In addition, 1?ng/mL IL-1? stimulated the P38, ERK, and JNK pathways, whereas pretreatment with allicin depressed this phenomenon, except for the ERK pathway. Conclusions. The inflammation induced by trinitrobenzenesulfonic acid is mitigated significantly by allicin treatment, particularly combined with mesalazine. Allicin inhibits the P38 and JNK pathways and the expression of NF-?B which explained the potential anti-inflammatory mechanisms of allicin. PMID:25729217

  18. Minnesota wolf ear lengths as possible indicators of taxonomic differences

    USGS Publications Warehouse

    Mech, L. David

    2011-01-01

    Genetic findings suggest that 2 types of wolves, Canis lupus (Gray Wolf) and C. lycaon (Eastern Wolf), and/or their hybrids occupy Minnesota (MN), and this study examines adult wolf ear lengths as a possible distinguisher between these two. Photographic evidence suggested that the Eastern Wolf possesses proportionately longer ears than Gray Wolves. Ear lengths from 22 northwestern MN wolves from the early 1970s and 22 Alaskan wolves were used to represent Gray Wolves, and the greatest length of the sample (12.8 cm) was used as the least length to demarcate Eastern Wolf from Gray Wolf influence in the samples. Twenty-three percent of 112 adult wolves from Algonquin Park in eastern Ontario and 30% of 106 recent adult wolves in northeastern MN possessed ears >12.8 cm. The northeastern MN sample differed significantly from that of current and past northwestern MN wolves. Ear-lengths of wolves in the eastern half of the northeastern MN wolf population were significantly longer than those in the western half of that study area, even though the mean distance between the 2 areas was only 40 km, and the mean length of my 2004–2009 sample was significantly longer than that of 1999–2003. These findings support the hypothesis that Eastern Wolves tend to possess longer ears than do Gray Wolves and suggest a dynamic hybridization process is still underway in MN.

  19. Inner ear morphological correlates of ultrasonic hearing in frogs.

    PubMed

    Arch, Victoria S; Simmons, Dwayne D; Quiñones, Patricia M; Feng, Albert S; Jiang, Jianping; Stuart, Bryan L; Shen, Jun-Xian; Blair, Chris; Narins, Peter M

    2012-01-01

    Three species of anuran amphibians (Odorrana tormota, Odorrana livida and Huia cavitympanum) have recently been found to detect ultrasounds. We employed immunohistochemistry and confocal microscopy to examine several morphometrics of the inner ear of these ultrasonically sensitive species. We compared morphological data collected from the ultrasound-detecting species with data from Rana pipiens, a frog with a typical anuran upper cut-off frequency of ?3 kHz. In addition, we examined the ears of two species of Lao torrent frogs, Odorrana chloronota and Amolops daorum, that live in an acoustic environment approximating those of ultrasonically sensitive frogs. Our results suggest that the three ultrasound-detecting species have converged on small-scale functional modifications of the basilar papilla (BP), the high-frequency hearing organ in the frog inner ear. These modifications include: 1. reduced BP chamber volume, 2. reduced tectorial membrane mass, 3. reduced hair bundle length, and 4. reduced hair cell soma length. While none of these factors on its own could account for the US sensitivity of the inner ears of these species, the combination of these factors appears to extend their hearing bandwidth, and facilitate high-frequency/ultrasound detection. These modifications are also seen in the ears of O. chloronota, suggesting that this species is a candidate for high-frequency hearing sensitivity. These data form the foundation for future functional work probing the physiological bases of ultrasound detection by a non-mammalian ear. PMID:22146424

  20. Computed tomography features of middle ear cholesteatoma in dogs.

    PubMed

    Travetti, Olga; Giudice, Chiara; Greci, Valentina; Lombardo, Rocco; Mortellaro, Carlo Maria; Di Giancamillo, Mauro

    2010-01-01

    We describe the computed tomography (CT) findings in 11 dogs with middle ear cholesteatoma. The cholesteatoma appeared as an expansile tympanic cavity mass with a mean attenuation value of 55.8 +/- 4.2 Hounsfield units. There was no appreciable contrast enhancement of the tympanic bulla contense but ring enhancement was seen in four dogs. Due to the slow progressive growth, the lesion causes severe bone changes at the contour of the tympanic bulla, including osteolysis, osteoproliferation and osteosclerosis, expansion of the tympanic cavity, and sclerosis or osteoproliferation of the ipsilateral temporomandibular joint and paracondylar process. Cholesteatoma can cause lysis of the petrosal part of the temporal bone, leading to intracranial complications. Although not definitive, CT provides useful information for distinguishing a middle ear cholesteatoma from otitis media and neoplasia. In otitis media, enlargement of the tympanic cavity is not routinely observed. In tumors that primarily affect the middle or inner ear, the predominant signs are lysis of the contour of the tympanic bulla or the petrosal part of the temporal bone, soft tissue swelling around the middle ear and marked contrast enhancement. In tumors that arise from the external ear, a soft tissue mass is visible within the external acusticus meatus, and the middle ear is only involved secondarily. PMID:20806867

  1. Retinoid Signaling in Inner Ear Development: a “Goldilocks” Phenomenon

    PubMed Central

    Frenz, Dorothy A.; Liu, Wei; Cvekl, Ales; Xie, Qing; Wassef, Lesley; Quadro, Loredana; Niederreither, Karen; Maconochie, Mark; Shanske, Alan

    2010-01-01

    Retinoic acid is a biologically active derivative of vitamin A that is indispensable for inner ear development. The normal function of retinoic acid is achieved only at optimal homeostatic concentrations, with an excess or deficiency in retinoic acid leading to inner ear dysmorphogenesis. We present an overview of the role of retinoic acid in the developing mammalian inner ear, discussing both how and when retinoic acid may act to critically control a program of inner ear development. Molecular mechanisms of otic teratogenicity involving two members of the fibroblast growth factor family, FGF3 and FGF10, and their downstream targets, Dlx5 and Dlx6, are examined under conditions of both retinoic acid excess and deficiency. We term the effect of too little or too much retinoic acid on FGF/Dlx signaling a Goldilocks phenomenon. We demonstrate that in each case (retinoic acid excess, retinoic acid deficiency), retinoic acid can directly affect FGF3/FGF10 signaling within the otic epithelium, leading to downregulated expression of these essential signaling molecules, which in turn, leads to diminution in Dlx5/Dlx6 expression. Non-cell autonomous affects of the otic epithelium subsequently occur, altering transforming growth factor beta (TGF?) expression in the neighboring periotic mesenchyme and serving as a putative explanation for retinoic acid-mediated otic capsule defects. We conclude that retinoic acid coordinates inner ear morphogenesis by controlling an FGF/Dlx signaling cascade, whose perturbation by deviations in local retinoid concentrations can lead to inner ear dysmorphogenesis. PMID:21108385

  2. Developmental origin and fate of middle ear structures.

    PubMed

    Sienknecht, Ulrike J

    2013-07-01

    Results from developmental and phylogenetic studies have converged to facilitate insight into two important steps in vertebrate evolution: (1) the ontogenetic origin of articulating elements of the buccal skeleton, i.e., jaws, and (2) the later origins of middle ear impedance-matching systems that convey air-borne sound to the inner ear fluids. Middle ear ossicles and other skeletal elements of the viscerocranium (i.e., gill suspensory arches and jaw bones) share a common origin both phylogenetically and ontogenetically. The intention of this brief overview of middle-ear development is to emphasize the intimate connection between evolution and embryogenesis. Examples of developmental situations are discussed in which cells of different provenance, such as neural crest, mesoderm or endoderm, gather together and reciprocal interactions finally determine cell fate. Effects of targeted mutagenesis on middle ear development are described to illustrate how the alteration of molecularly-controlled morphogenetic programs led to phylogenetic modifications of skeletal development. Ontogenetic plasticity has enabled the diversification of jaw elements as well as middle ear structures during evolution. This article is part of a special issue entitled "MEMRO 2012". PMID:23396272

  3. Modulation of arachidonic and linoleic acid metabolites in myeloperoxidase-deficient mice during acute inflammation.

    PubMed

    Kubala, Lukas; Schmelzer, Kara R; Klinke, Anna; Kolarova, Hana; Baldus, Stephan; Hammock, Bruce D; Eiserich, Jason P

    2010-05-15

    Acute inflammation is a common feature of many life-threatening pathologies, including septic shock. One hallmark of acute inflammation is the peroxidation of polyunsaturated fatty acids forming bioactive products that regulate inflammation. Myeloperoxidase (MPO) is an abundant phagocyte-derived hemoprotein released during phagocyte activation. Here, we investigated the role of MPO in modulating biologically active arachidonic acid (AA) and linoleic acid (LA) metabolites during acute inflammation. Wild-type and MPO-knockout (KO) mice were exposed to intraperitoneally injected endotoxin for 24 h, and plasma LA and AA oxidation products were comprehensively analyzed using a liquid chromatography-mass spectrometry method. Compared to wild-type mice, MPO-KO mice had significantly lower plasma levels of LA epoxides and corresponding LA- and AA-derived fatty acid diols. AA and LA hydroxy intermediates (hydroxyeicosatetraenoic and hydroxyoctadecadienoic acids) were also significantly lower in MPO-KO mice. Conversely, MPO-deficient mice had significantly higher plasma levels of cysteinyl-leukotrienes with well-known proinflammatory properties. In vitro experiments revealed significantly lower amounts of AA and LA epoxides, LA- and AA-derived fatty acid diols, and AA and LA hydroxy intermediates in stimulated polymorphonuclear neutrophils isolated from MPO-KO mice. Our results demonstrate that MPO modulates the balance of pro- and anti-inflammatory lipid mediators during acute inflammation and, in this way, may control acute inflammatory diseases. PMID:20156554

  4. Anti-inflammatory Activity of Magnesium Isoglycyrrhizinate Through Inhibition of Phospholipase A2/Arachidonic Acid Pathway.

    PubMed

    Xie, Chunfeng; Li, Xiaoting; Wu, Jieshu; Liang, Zhaofeng; Deng, Feifei; Xie, Wei; Zhu, Mingming; Zhu, Jianyun; Zhu, Weiwei; Geng, Shanshan; Zhong, Caiyun

    2015-08-01

    Glycyrrhiza glabra (licorice) has been known to possess various pharmacological properties including anti-inflammatory, antioxidants, antiviral, and hepatoprotective activities. Magnesium isoglycyrrhizinate (MgIG), a magnesium salt of 18-? glycyrrhizic acid stereoisomer, is clinically used for the treatment of inflammatory liver diseases. However, the mechanism by which MgIG exerts its anti-inflammatory effects remains unknown. In the present study, we investigated the inhibitory potential of MgIG in phospholipase A2 (PLA2)/arachidonic acid (AA) pathway and release of the pathway-generated inflammatory lipid mediators in RAW264.7 macrophages. Results revealed that MgIG suppressed LPS-induced activation of PLA2 and production of AA metabolites such as prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane 2 (TXB2), and leukotrienes (LTB4) in macrophages. Furthermore, LPS-induced AA-metabolizing enzymes including COX-2, COX-1, 5-LOX, TXB synthase, and PGI2 synthase were significantly inhibited by MgIG. Taken together, our data suggest that modulation of cyclooxygenase (COXs) and 5-lipoxygenase (LOX) pathways in AA metabolism could be a novel mechanism for the anti-inflammatory effects of MgIG. PMID:25691139

  5. Epoxygenase metabolites of arachidonic acid inhibit vasopressin response in toad bladder

    SciTech Connect

    Schlondorff, D.; Petty, E.; Oates, J.A.; Jacoby, M.; Levine, S.D. (Albert Einstein College of Medicine, Bronx, NY (USA) Vanderbilt Univ., Nashville, TN (USA))

    1987-09-01

    In addition to cyclooxygenase and lipoxygenase pathways, the kidney can also metabolize arachidonic acid by a NADPH-dependent cytochrome P-450 enzyme to epoxyeicosatrienoic acids (EETs); furthermore, 5,6-EET has been shown to alter electrolyte transport across isolated renal tubules. The authors examined the effects of three ({sup 14}C-labeled)-EETs (5,6-, 11,12-, and 14,15-EET) on osmotic water flow across toad urinary bladder. All three EETs reversibly inhibited vasopressin-stimulated osmotic water flow with 5,6- and 11,12-EET being the most potent. The effects appeared to be independent of prostaglandins EETs inhibited the water flow response to forskolin but not the response to adenosine 3{prime},5{prime}-cyclic monophosphate (cAMP) or 8-BrcAMP, consistent with an effect on cAMP generation. To determine whether these effects were due to the EETs or to products of their metabolism, they examined the effects of their vicinal diol hydrolysis products, the dihydroxyeicosatrienoic acids. Nonenzymatic conversion of labeled 5,6-EET to its vicinal diol occurred rapidly in the buffer, whereas 11,12-EET was hydrolyzed in a saturable manner only when incubated in the presence of bladder tissue. The dihydroxyeicosatrienoic acids formed inhibited water flow in a manner paralleling that of the EETs. The data support the hypothesis that EETs and their physiologically active dihydroxyeicosatrienoic acid metabolites inhibit vasopressin-stimulated water flow predominantly via inhibition of adenylate cyclase.

  6. Intestinal zinc transport: influence of streptozotocin-induced diabetes, insulin and arachidonic acid

    SciTech Connect

    Song, M.K.; Mooradian, A.D.

    1988-01-01

    The influence of arachidonic acid (AA) on the zinc flux rates of jejunal segments, isolated from streptozotocin-induced diabetic rats injected with saline or with insulin, was investigated using an Ussing chamber technique. Although the zinc flux rates from mucose-to-serosa (J/sub ms/) of normal rats were inhibited by addition of 5 ..mu..M AA to the jejunal segment bathing medium, AA had no effect on the J/sub ms/ of diabetic rats either with or without insulin treatment. Induction of diabetes also significantly reduces J/sub ms/, but 3 day insulin treatment did not reverse this effect. Addition of AA to the serosal side did not significantly alter the zinc flux rate from serosa-to-mucosa (J/sub sm/) in either control, diabetic or diabetic rats treated with insulin. The net zinc absorption rate (J/sub net/) of jejunal segments was decreased in diabetic rats compared to controls, but normalization of blood glucose with 3 day insulin treatment did not increase J/sub net/. Addition of AA was associated with a tendency to increase zinc uptake capacity. This change reached statistical significance in insulin treated diabetic rats. Short-circuit current (I/sub sc/) for diabetic rats was increased compared to controls but addition of AA to the mucosal side bathing medium decreased I/sub sc/ in all groups. 32 references, 3 figures, 1 table.

  7. Arachidonate 15-lipoxygenase is required for chronic myeloid leukemia stem cell survival

    PubMed Central

    Chen, Yaoyu; Peng, Cong; Abraham, Sheela A.; Shan, Yi; Guo, Zhiru; Desouza, Ngoc; Cheloni, Giulia; Li, Dongguang; Holyoake, Tessa L.; Li, Shaoguang

    2014-01-01

    Cancer stem cells (CSCs) are responsible for the initiation and maintenance of some types of cancer, suggesting that inhibition of these cells may limit disease progression and relapse. Unfortunately, few CSC-specific genes have been identified. Here, we determined that the gene encoding arachidonate 15-lipoxygenase (Alox15/15-LO) is essential for the survival of leukemia stem cells (LSCs) in a murine model of BCR-ABL–induced chronic myeloid leukemia (CML). In the absence of Alox15, BCR-ABL was unable to induce CML in mice. Furthermore, Alox15 deletion impaired LSC function by affecting cell division and apoptosis, leading to an eventual depletion of LSCs. Moreover, chemical inhibition of 15-LO function impaired LSC function and attenuated CML in mice. The defective CML phenotype in Alox15-deficient animals was rescued by depleting the gene encoding P-selectin, which is upregulated in Alox15-deficient animals. Both deletion and overexpression of P-selectin affected the survival of LSCs. In human CML cell lines and CD34+ cells, knockdown of Alox15 or inhibition of 15-LO dramatically reduced survival. Loss of Alox15 altered expression of PTEN, PI3K/AKT, and the transcription factor ICSBP, which are known mediators of cancer pathogenesis. These results suggest that ALOX15 has potential as a therapeutic target for eradicating LSCs in CML. PMID:25105362

  8. Effects of dietary trans acids on the biosynthesis of arachidonic acid in rat liver microsomes.

    PubMed

    Kurata, N; Privett, O S

    1980-12-01

    Effects of dietary trans acids on the interconversion of linoleic acid was studied using the liver microsomal fraction of rats fed a semipurified diet containing fat supplements of safflower oil (SAFF), hydrogenated coconut oil (HCO) at 5 and 20 at and 20% levels or a 5% level of a supplement containing 50.3% linolelaidic and 24.3% elaidic acids devoid of cis,cis-linoleic acid (TRANS). Growth rate was suppressed to greater extent with the animals fed the 20% than the 5% level of the HCO-supplemented diets and still further by the TRANS diet compared to the groups fed the SAFF diets. Food intake was greater in the groups fed the HCO than the SAFF-supplemented diets, demonstrating the marked effect of an essential fatty acid (EFA) deficiency on feed efficiency. In contrast to an EFA deficiency produced by the HCO supplement, which stimulated the in vitro liver microsomal biosynthesis of arachidonic acid, diets containing the TRANS supplement exacerabated the EFA deficiency and depressed 6-desaturase activity of the liver microsomal fraction. The liver microsomal fraction of the animals receiving this supplement also was more sensitive to fatty acid inhibition of the desaturation of linoleic acid than those obtained from animals fed either the SAFF or HCO diets. It is suggested that dietary trans acids alter the physical properties of the 6-desaturase enzyme system, suppressing its activity, which increases the saturation of the tissue lipids and, in turn, the requirement for EFA or polyunsaturated fatty acids. PMID:7219072

  9. The effect of trinitrobenzene sulfonic acid (TNB) on colonocyte arachidonic acid metabolism.

    PubMed

    Stratton, M D; Sexe, R; Peterson, B; Kaminski, D L; Li, A P; Longo, W E

    1996-02-01

    In previous studies we found that luminal perfusion of the isolated left colon of the rabbit with the hapten, trinitrobenzene, resulted in the production of an acute inflammatory process associated with alterations in eicosanoid metabolism. As the colitis was attenuated by cyclooxygenase inhibitors it is possible that the inflammation was mediated by arachidonic acid metabolites. In the present study it was intended to evaluate the effect of trinitrobenzene on eicosanoid metabolism in transformed human colonic cells by exposing Caco-2++ cells to various doses of trinitrobenzene. Cell injury was evaluated by measuring lactate dehydrogenase levels and cyclooxygenase and lipoxygenase activity was evaluated by measuring prostanoid and leukotriene production. In separate experiments resting and trinitrobenzene stimulated cells were treated with indomethacin and dexamethasone. Trinitrobenzene produced increased prostaglandin E2 and 6-keto prostaglandin F1alpha++ and increased lactate dehydrogenase levels. Leukotriene B4 was significantly increased compared to control values at the highest TNB concentration administered. Indomethacin inhibited the lactate dehydrogenase and prostanoid changes, suggesting that the inflammatory changes produced were mediated by the prostanoids. Dexamethasone administered for 1 hr prior to trinitrobenzene decreased the 6-keto prostaglandin F1alpha but did not alter trinitrobenzene produced changes in lactate dehydrogenase concentrations. Exposure of Caco-2 cells to dexamethasone for 24 hr decreased the trinitrobenzene produced lactate dehydrogenase and eicosanoid changes. The results suggest that trinitrobenzene produces an acute injury to Caco-2 cells that may be mediated by the cyclooxygenase enzymes. PMID:8598672

  10. Incorporation and effect of arachidonic acid on the growth of human myeloma cell lines.

    PubMed Central

    Desplat, V; Dulery, C; Praloran, V; Denizot, Y

    1999-01-01

    The objectives of this work are to investigate the incorporation of arachidonic acid (AA) in the human myeloma cell lines OPM2, U266 and IM9, and to assess the effect of AA and lipoxygenase products of AA on their growth. The kinetics of acylation of [3H]AA indicates that myeloma cells incorporate AA into their membrane phospholipids and triglycerides. PLA2-treatment and base hydrolysis experiments confirm that [3H]AA is incorporated unmodified in U266, IM9 and OPM2 phospholipids, and is linked by an ester bond. Prelabeling-chase experiments indicate no trafficking of labeled AA among the various phospholipid species. Addition of AA and lipoxygenase products of AA (leukotriene B4 and C4, lipoxin A4 and B4, 12- and 15-hydroxyeicosatetraenoic acid) have no effect on U266, IM9 and OPM2 proliferation assessed by [3H]thymidine incorporation into DNA. In conclusion, while human myeloma cells readily incorporate AA in their membrane phospholipids and triglycerides, AA and lipoxygenase products are not important modulators of their proliferation. PMID:10704149

  11. Calcium ionophore synergizes with bacterial lipopolysaccharides in activating macrophage arachidonic acid metabolism

    PubMed Central

    1988-01-01

    LPS, a major component of Gram-negative bacterial cell walls, prime macrophages for greatly enhanced arachidonic acid [20:4] metabolism when the cells are subsequently stimulated. The LPS-primed macrophage has been used as a model system in which to study the role of Ca2+ in the regulation of 20:4 metabolism. The Ca2+ ionophore A23187 (0.1 microM) triggered the rapid release of 20:4 metabolites from LPS-primed macrophages but not from cells not previously exposed to LPS. Macrophages required exposure to LPS for at least 40 min before A23187 became effective as a trigger. A23187 (0.1 microM) also synergized with PMA in activating macrophage 20:4 metabolism. The PMA effect could be distinguished from that of LPS since no preincubation with PMA was required. A23187 greatly increased the amount of lipoxygenase products secreted from LPS-primed macrophages, leukotriene C4 synthesis being increased 150-fold. LPS-primed macrophages, partially permeabilized to Ca2+ with A23187, were used to titrate the Ca2+ concentration dependence of the cyclooxygenase and lipoxygenase pathways. Cyclooxygenase metabolites were detected at an order of magnitude lower Ca2+ concentration than were lipoxygenase products. The data suggest that Ca2+ regulates macrophage 20:4 metabolism at two distinct steps: an increase in intracellular Ca2+ regulates the triggering signal and relatively higher Ca2+ concentrations are required for 5-lipoxygenase activity. PMID:3126256

  12. Relative incorporation of arachidonic and eicosapentaenoic acids into human platelet phospholipids

    SciTech Connect

    Weaver, B.J.; Holub, B.J.

    1985-11-01

    The incorporation of arachidonic acid (AA) as compared to eicosapentaenoic acid (EPA) into human platelet phospholipids was tested by incubating washed platelets with a known mixture of (3H)AA and (14C)EPA. Following incubation, the platelet lipids were extracted, the individual phospholipids--phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI) and phosphatidylethanolamine (PE)- were separated by thin layer chromatography, and their corresponding (3H)/(14C) ratios were determined. Based on a (3H)/(14C) ratio of unity for the substrate mixture, the PC, PS, PI and PE exhibited ratios of 0.55, 0.93, 1.12 and 0.74, respectively, which were significantly different from 1.00 in all instances except in the case of PS. These results indicate that PC and PE selectively incorporated EPA, while PI showed preference toward AA. These selectivities may account partly for the differing AA/EPA mass ratios that have been observed among the individual phospholipids of human subjects consuming fish oils.

  13. Calcium-dependent phospholipid catabolism and arachidonic acid mobilization in cerebral minces

    SciTech Connect

    Damron, D.S.; Dorman, R.V. (Kent State Univ., OH (USA))

    1990-06-01

    Cerebral minces were used to investigate the role of calcium influx on trauma-induced alterations of brain lipid metabolism. Cerebral phospholipids, nonpolar lipids, and free fatty acids were radiolabeled in vivo with ({sup 3}H)arachidonic acid. Tissue incubation stimulated the time-dependent catabolism of choline and inositol glycerophospholipids, and resulted in the accumulation of ({sup 3}H)free fatty acids. These effects were attenuated in Ca{sup 2}{sup +}-free incubations, and when EGTA or verapamil were present. The inhibition of calcium influx also reduced the labeling of diglycerides, whereas ethanolamine and serine glycerophospholipids were not affected by incubation or treatments. Replacing Ca{sup 2}{sup +} with other cations also attenuated the incubation-dependent alterations in lipid metabolism. However, only cadmium was able to compete with calcium and reduce the accumulation of ({sup 3}H)free fatty acids. It appeared that about half of the observed phospholipid catabolism was dependent on Ca{sup 2}{sup +} influx and that at least 80% of the ({sup 3}H)free fatty acid accumulation required calcium.

  14. Safety evaluation of arachidonic acid rich Mortierella alpina biomass in albino rats--a subchronic study.

    PubMed

    Nisha, A; Muthukumar, S P; Venkateswaran, G

    2009-04-01

    Safety evaluation of arachidonic acid rich Mortierella alpina biomass was carried out in Wistar rats by acute and subchronic oral toxicity studies. A preliminary acute toxicity study revealed that the biomass was safe at acute doses and that the LD50 exceeded 5000mg/kg BW, the highest dose used in the study. In subchronic study, rats were fed diet containing 0, 2500, 5000, 10,000, 20,000 and 30,000mg/kg, M. alpina biomass for a period of 13 weeks. Results indicated that biomass fortification had a positive influence on growth with no overt toxic effects on the survival, food consumption and body weight gain throughout the treatment interlude. The statistically significant changes in relative organ weights, serum biochemical and hematological indices in M. alpina fed groups' viz., higher relative weights of spleen, liver, brain and ovary in females, reduced hemoglobin concentration in males, elevated WBC counts at highest dose, reduction in serum triglycerides and increased alkaline phosphatase activity were not concomitant with pertinent histopathological changes and hence toxicologically inconsequential. No microscopic or macroscopic lesions attributable to the treatment were manifested in the experimental groups. The results of the present study strongly advocate the safety of M. alpina biomass in rats at levels used in the study. PMID:19545514

  15. CYP4A metabolites of arachidonic acid and VEGF are mediators of skeletal muscle angiogenesis.

    PubMed

    Amaral, Sandra L; Maier, Kristopher G; Schippers, Daniela N; Roman, Richard J; Greene, Andrew S

    2003-05-01

    Vascular endothelial growth factor (VEGF) has been implicated in angiogenesis induced by electrical stimulation in skeletal muscle. Less is known about the role of arachidonic acid metabolites in the control of growth of blood vessels in vivo. The present study examined the role of 20-hydroxyeicosatetraenoic acid (20-HETE) on the angiogenesis induced by electrical stimulation in skeletal muscle. The tibialis anterior and extensor digitorum longus muscles of rats were stimulated for 7 days. Electrical stimulation significantly increased the 20-HETE formation and angiogenesis in the muscles, which was blocked by chronic treatment with N-hydroxy-N'-(4-butyl-2-methylphenol)formamidine (HET0016) or 1-aminobenzotriazole (ABT). Chronic treatment with either HET0016 or ABT did not block the increases in VEGF protein expression in both muscles. To analyze the role of VEGF on 20-HETE formation, additional rats were treated with VEGF-neutralizing antibody (VEGF Ab). VEGF Ab blocked the increases of 20-HETE formation induced by stimulation. These results place 20-HETE in the downstream signaling pathway for angiogenesis and show that both VEGF and 20-HETE are involved in the angiogenesis induced by electrical stimulation in skeletal muscle. PMID:12521947

  16. Arachidonic acid-dependent gene regulation during preadipocyte differentiation controls adipocyte potential[S

    PubMed Central

    Nikolopoulou, Evanthia; Papacleovoulou, Georgia; Jean-Alphonse, Frederic; Grimaldi, Giulia; Parker, Malcolm G.; Hanyaloglu, Aylin C.; Christian, Mark

    2014-01-01

    Arachidonic acid (AA) is a major PUFA that has been implicated in the regulation of adipogenesis. We examined the effect of a short exposure to AA at different stages of 3T3-L1 adipocyte differentiation. AA caused the upregulation of fatty acid binding protein 4 (FABP4/aP2) following 24 h of differentiation. This was mediated by the prostaglandin F2? (PGF2?), as inhibition of cyclooxygenases or PGF2? receptor signaling counteracted the AA-mediated aP2 induction. In addition, calcium, protein kinase C, and ERK are all key elements of the pathway through which AA induces the expression of aP2. We also show that treatment with AA during the first 24 h of differentiation upregulates the expression of the transcription factor Fos-related antigen 1 (Fra-1) via the same pathway. Finally, treatment with AA for 24 h at the beginning of the adipocyte differentiation is sufficient to inhibit the late stages of adipogenesis through a Fra-1-dependent pathway, as Fra-1 knockdown rescued adipogenesis. Our data show that AA is able to program the differentiation potential of preadipocytes by regulating gene expression at the early stages of adipogenesis. PMID:25325755

  17. Modulation of arachidonic and linoleic acid metabolites in myeloperoxidase deficient mice during acute inflammation

    PubMed Central

    Kubala, Lukas; Schmelzer, Kara R.; Klinke, Anna; Kolarova, Hana; Baldus, Stephan; Hammock, Bruce D.; Eiserich, Jason P.

    2010-01-01

    Acute inflammation is a common feature of many life-threatening pathologies, including septic shock. One hallmark of acute inflammation is the peroxidation of polyunsaturated fatty acids forming bioactive products, which regulate inflammation. Myeloperoxidase (MPO) is an abundant phagocyte-derived hemoprotein released during phagocyte activation. Here, we investigated the role of MPO in modulating biologically active arachidonic acid (AA) and linoleic acid (LA) metabolites during acute inflammation. Wild-type and MPO-knockout (KO) mice were exposed to intraperitoneally injected endotoxin for 24 h, and plasma LA and AA oxidation products were comprehensively analyzed using a liquid chromatography-mass spectrometry method. Compared to wild-type mice, MPO-KO mice had significantly lower plasma levels of LA epoxides and corresponding LA- and AA-derived fatty acid diols. AA and LA hydroxy intermediates (hydroxyeicosatetraenoic and hydroxyoctadecadienoic acids) were also significantly lower in MPO-KO mice. Conversely, MPO-deficient mice had significantly higher plasma levels of cysteinyl-leukotrienes with well-known pro-inflammatory properties. In vitro experiments revealed significantly lower amounts of AA and LA epoxides, LA- and AA-derived fatty acid diols, and AA and LA hydroxy intermediates in stimulated polymorphonuclear neutrophils isolated from MPO-KO mice. Our results demonstrate that MPO modulates the balance of pro- and anti-inflammatory lipid mediators during acute inflammation. In this way, may control acute inflammatory diseases. PMID:20156554

  18. Dietary arachidonic acid-mediated effects on colon inflammation using transcriptome analysis.

    PubMed

    Knoch, Bianca; Barnett, Matthew P G; McNabb, Warren C; Zhu, Shuotun; Park, Zaneta A; Khan, Anar; Roy, Nicole C

    2010-05-01

    Increased levels of n-6 arachidonic acid (AA), a precursor of pro-inflammatory eicosanoids, have been found in the colon mucosa of inflammatory bowel disease patients when compared with healthy subjects. The hypothesis was that dietary AA would aggravate colon inflammation by changing expression of genes in inflammatory signaling pathways. AA-enriched diet was fed to IL10 gene-deficient (Il10-/-) mice, model of a inflammatory bowel disease, and compared with Il10-/- mice fed an oleic acid control diet. Effects of AA on gene expression profiles during colitis were examined using whole genome microarray analysis. Dietary AA decreased the expression levels of some colonic genes in ER stress, complement system, nuclear respiratory factor 2-mediated oxidative stress and positive acute phase response pathways compared with Il10-/- mice fed an oleic acid diet. AA increased the expression levels of fatty acid catabolism genes, but decreased that of lipid synthesis genes during colitis, likely by sterol regulatory element binding transcription factor 1 and target gene regulation. A link has been suggested between AA and reduction of intestinal fibrosis by down-regulating the expression levels of pro-inflammatory and fibrotic marker genes. Contrary to the hypothesis, these findings suggest that dietary AA, in the present experimental conditions, is not pro-inflammatory, reduces ER stress and protects colonocytes from oxidative stress in Il10-/- mice. PMID:20440721

  19. Arachidonic acid-rich oil production by Mortierella alpina with different gas distributors.

    PubMed

    Nie, Zhi-Kui; Ji, Xiao-Jun; Shang, Jing-Sheng; Zhang, Ai-Hui; Ren, Lu-Jing; Huang, He

    2014-06-01

    Arachidonic acid (ARA)-rich oil production by Mortierella alpina is a high oxygen demand and shear-sensitive process. In the aerobic fermentation process, oxygen supply is usually a limiting factor owing to the low solubility of oxygen in the fermentation broth. Two kinds of perforated ring gas distributors and a novel microporous ceramic membrane gas distributor were designed and applied to improve oxygen supply. With the decrease of the orifice diameter of perforated ring gas distributors, dry cell weight (DCW), lipids concentration, and ARA content in total fatty acid increased from 17.86 g/L, 7.08 g/L, and 28.08 % to 25.67 g/L, 11.94 g/L, and 36.99 %, respectively. Furthermore, the effect of different dissolved oxygen (DO) on ARA-rich oil production with membrane gas distributor was also studied. The maximum DCW, lipid concentration, and ARA content using membrane gas distributor with DO controlled at 40 % reached 29.67 g/L, 16.74 g/L, and 49.53 %, respectively. The ARA titer increased from 1.99 to 8.29 g/L using the membrane gas distributor to substitute the perforated ring gas distributor. In the further experiment, a novel tubular titanium metal membrane gas distributor was successfully applied in a 7,000 L bioreactor and the results demonstrated that membrane gas distributor was industrially practical. PMID:24374968

  20. Breast milk from women living near Lake Malawi is high in docosahexaenoic acid and arachidonic acid.

    PubMed

    Jimenez, E Yakes; Mangani, C; Ashorn, P; Harris, W S; Maleta, K; Dewey, K G

    2015-04-01

    Adequate long-chain polyunsaturated fatty acid (LCPUFA) intake is critical during the fetal and infant periods. We quantified fatty acid content of breast milk (n=718) and plasma from six month old infants (n=412) in southern Malawi, and in usipa (n=3), a small dried fish from Lake Malawi. Compared to global norms, Malawian breast milk fatty acid content (% of total fatty acids) was well above average levels of arachidonic acid [ARA] (0.69% vs. 0.47%) and docosahexaenoic acid [DHA] (0.73% vs. 0.32%). Average Malawian infant plasma ARA (7.5%) and DHA (3.8%) levels were comparable to those reported in infants consuming breast milk with similar fatty acid content. The amounts (mg) of DHA, EPA and ARA provided by a 3 oz (85 g) portion of dried usipa (1439, 659 and 360, respectively) are considerably higher than those for dried salmon. Usipa may be an important source of LCPUFA for populations in this region. PMID:25601798

  1. Arachidonic Acid: An Evolutionarily Conserved Signaling Molecule Modulates Plant Stress Signaling Networks[C][W

    PubMed Central

    Savchenko, Tatyana; Walley, Justin W.; Chehab, E. Wassim; Xiao, Yanmei; Kaspi, Roy; Pye, Matthew F.; Mohamed, Maged E.; Lazarus, Colin M.; Bostock, Richard M.; Dehesh, Katayoon

    2010-01-01

    Fatty acid structure affects cellular activities through changes in membrane lipid composition and the generation of a diversity of bioactive derivatives. Eicosapolyenoic acids are released into plants upon infection by oomycete pathogens, suggesting they may elicit plant defenses. We exploited transgenic Arabidopsis thaliana plants (designated EP) producing eicosadienoic, eicosatrienoic, and arachidonic acid (AA), aimed at mimicking pathogen release of these compounds. We also examined their effect on biotic stress resistance by challenging EP plants with fungal, oomycete, and bacterial pathogens and an insect pest. EP plants exhibited enhanced resistance to all biotic challenges, except they were more susceptible to bacteria than the wild type. Levels of jasmonic acid (JA) were elevated and levels of salicylic acid (SA) were reduced in EP plants. Altered expression of JA and SA pathway genes in EP plants shows that eicosapolyenoic acids effectively modulate stress-responsive transcriptional networks. Exogenous application of various fatty acids to wild-type and JA-deficient mutants confirmed AA as the signaling molecule. Moreover, AA treatment elicited heightened expression of general stress-responsive genes. Importantly, tomato (Solanum lycopersicum) leaves treated with AA exhibited reduced susceptibility to Botrytis cinerea infection, confirming AA signaling in other plants. These studies support the role of AA, an ancient metazoan signaling molecule, in eliciting plant stress and defense signaling networks. PMID:20935246

  2. Erythema associated with pain and warmth on face and ears: a variant of erythermalgia or red ear syndrome?

    PubMed Central

    2014-01-01

    Erythermalgia is a rare cutaneous disorder characterized by attacking of erythema, pain and increased temperature, which primarily involves the extremities and may infrequently extend to the neck, face, ears and even the scrotum. We reported an 18-year-old woman who presented with 3 years history of sole involvement of attacking erythema, pain and warmth over her face and ears without any other associations. The frequency and severity of the flares progressed gradually during the course. Cutaneous examination revealed erythema, increased temperature and tenderness on the face and ears during the flare. The symptoms could be relieved rapidly by cooling. Dermatoscope showed that vessels inside the erythema were more dilated during the episode than after application of ice. The lesion is considered a rare variant of erythermalgia with sole involvement of face and ears. The symptoms had mild response to oral antihistamines, topical steroids and tacrolimus, but had excellent response to the combinative therapy of aspirin and paroxetins. PMID:24670221

  3. Mastoid obliteration combined with soft-wall reconstruction of posterior ear canal

    Microsoft Academic Search

    Haruo Takahashi; Tetsu Iwanaga; Satoru Kaieda; Tomomi Fukuda; Hidetaka Kumagami; Kenji Takasaki; Seishi Hasebe; Kazuo Funabiki

    2007-01-01

    To clarify the usefulness of modified soft-wall reconstruction method by combing with mastoid obliteration, 96 patients (98\\u000a ears) with their age ranging from 5 to 82 (average 51.3), including 62 ears with chronic otitis media (COM) with cholesteatoma,\\u000a 18 ears with non-cholesteatomatous COM, 14 ears with postoperative cavity problem, and 4 ears with adhesive-type COM, who\\u000a had soft-wall reconstruction of

  4. Acoustic–structural coupled finite element analysis for sound transmission in human ear—Pressure distributions

    Microsoft Academic Search

    Rong Z. Gan; Qunli Sun; Bin Feng; Mark W. Wood

    2006-01-01

    A three-dimensional (3D) finite element (FE) model of human ear with accurate structural geometry of the external ear canal, tympanic membrane (TM), ossicles, middle ear suspensory ligaments, and middle ear cavity has been recently reported by our group. In present study, this 3D FE model was modified to include acoustic–structural interfaces for coupled analysis from the ear canal through the

  5. Bacterial isolates and drug susceptibility patterns of ear discharge from patients with ear infection at Gondar University Hospital, Northwest Ethiopia

    PubMed Central

    2013-01-01

    Background Ear infection is a common problem for both children and adults especially in developing countries. However in Ethiopia particularly in the study area, there is no recent data that shows the magnitude of the problem. The aim of this study was to determine the bacterial isolates and their drug susceptibility patterns from patients who had ear infection. Method A retrospective study was conducted from September, 2009 to August, 2012 at Gondar University Hospital, Northwest Ethiopia. Ear discharge samples were cultured on MacConkey agar, blood agar and chocolate agar plates. A standard biochemical procedure was used for full identification of bacterial isolates. Antimicrobial susceptibility tests were done on Mueller-Hinton agar by using disk diffusion method. Data were entered and analyzed by using SPSS version 20 software and P-value of?ear discharge samples were tested for bacterial isolation and 204 (89.5%) cases were found to have bacterial isolates. From the total bacterial isolates, 115 (56.4%) were gram negative bacteria and the predominant isolate was proteus species (27.5%). Of individuals who had ear infection, 185 (90.7%) had single bacterial infection while 19 (9.3%) had mixed infections. Under five children were more affected by ear infection. The prevalence of ear infection was significantly high in males (63.7 vs 36.3%) (P?=?0.017). Of all bacterial isolates, 192 (94.1%) had multiple antibiotic resistant pattern. Non Lactose Fermenter Gram Negative Rods (46.0%), Klebsella species (47.7%) and Pseudomonas species (48.5%) were resistant against the commonly used antibiotics. Conclusion The prevalence of ear infection was very high in the study area. Majority of the bacterial isolates were resistant to multiple antibiotics. Hence antibiotics susceptibility test is mandatory before prescribing any antibiotics. PMID:23914777

  6. Palmitic acid-induced activation of human T-lymphocytes and aortic endothelial cells with production of insulin receptors, reactive oxygen species, cytokines, and lipid peroxidation

    Microsoft Academic Search

    Frankie B. Stentz; Abbas E. Kitabchi

    2006-01-01

    Diabetic conditions are associated with hyperglycemia and hyperlipidemia, but the role of saturated fatty acids (SFA) vs. unsaturated fatty acids (UFA) in activation of T-lymphocytes and human aortic endothelial cells (HAEC) is not known. We investigated in vitro effects of various concentrations of SFA (palmitate) and UFA (oleic, linoleic, linolenic, and arachidonic) acids in activation of these cells. These cells

  7. Xuebijing injection improves the respiratory function in rabbits with oleic acid-induced acute lung injury by inhibiting IL-6 expression and promoting IL-10 expression at the protein and mRNA levels.

    PubMed

    Wang, Yuxia; Ji, Mingli; Wang, Lei; Chen, Liping; Li, Jing

    2014-11-01

    Xuebijing injection is a complex herbal medicine, and clinical and experimental studies have shown that it has a significant effect on acute respiratory distress syndrome and multiple organ dysfunction syndrome. However, the majority of studies regarding Xuebijing injection have focused on serum inflammatory factors, and few studies have been carried out from the perspective of the protein and mRNA expression of inflammatory cytokines. In this study, 60 healthy rabbits of mixed gender were randomly assigned to a normal control group (CG), oleic acid group (model group; MG) and oleic acid + Xuebijing injection group (treatment group; TG). Rabbits of the CG were treated with normal saline through the ear vein, rabbits of the MG were injected with oleic acid (0.4 ml/kg) and rabbits of the TG received 0.4 ml/kg oleic acid + 10 ml/kg Xuebijing injection. Blood samples were collected from the common carotid artery of all rabbits of all groups 1 h after the ear vein was injected with the corresponding reagent, and was used to measure the arterial partial pressure of oxygen (PaO2) and of carbon dioxide (PaCO2). The activity of myeloperoxidase (MPO) was tested, and the protein and mRNA expression levels of interleukin (IL)-6 and IL-10 were determined. Rabbits of the MG exhibited evident respiratory dysfunction (PaO2 and PaCO2 were low), histopathological lung damage and overactive inflammatory responses (the expression of the proinflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10 was increased at the protein and mRNA levels). Following the administration of the Xuebijing injection, the inflammatory response of the rabbits was significantly reduced. Xuebijing injection raised PaO2 and PaCO2, weakened the activity of MPO in the lung tissue, downregulated the expression of the proinflammatory cytokine IL-6 and further increased the expression of the anti-inflammatory cytokine IL-10. These results demonstrated that Xuebijing injection improved the respiratory function of rabbits with acute oleic acid-induced lung injury by inhibiting IL-6 expression and promoting IL-10 expression. PMID:25289065

  8. Xuebijing injection improves the respiratory function in rabbits with oleic acid-induced acute lung injury by inhibiting IL-6 expression and promoting IL-10 expression at the protein and mRNA levels

    PubMed Central

    WANG, YUXIA; JI, MINGLI; WANG, LEI; CHEN, LIPING; LI, JING

    2014-01-01

    Xuebijing injection is a complex herbal medicine, and clinical and experimental studies have shown that it has a significant effect on acute respiratory distress syndrome and multiple organ dysfunction syndrome. However, the majority of studies regarding Xuebijing injection have focused on serum inflammatory factors, and few studies have been carried out from the perspective of the protein and mRNA expression of inflammatory cytokines. In this study, 60 healthy rabbits of mixed gender were randomly assigned to a normal control group (CG), oleic acid group (model group; MG) and oleic acid + Xuebijing injection group (treatment group; TG). Rabbits of the CG were treated with normal saline through the ear vein, rabbits of the MG were injected with oleic acid (0.4 ml/kg) and rabbits of the TG received 0.4 ml/kg oleic acid + 10 ml/kg Xuebijing injection. Blood samples were collected from the common carotid artery of all rabbits of all groups 1 h after the ear vein was injected with the corresponding reagent, and was used to measure the arterial partial pressure of oxygen (PaO2) and of carbon dioxide (PaCO2). The activity of myeloperoxidase (MPO) was tested, and the protein and mRNA expression levels of interleukin (IL)-6 and IL-10 were determined. Rabbits of the MG exhibited evident respiratory dysfunction (PaO2 and PaCO2 were low), histopathological lung damage and overactive inflammatory responses (the expression of the proinflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10 was increased at the protein and mRNA levels). Following the administration of the Xuebijing injection, the inflammatory response of the rabbits was significantly reduced. Xuebijing injection raised PaO2 and PaCO2, weakened the activity of MPO in the lung tissue, downregulated the expression of the proinflammatory cytokine IL-6 and further increased the expression of the anti-inflammatory cytokine IL-10. These results demonstrated that Xuebijing injection improved the respiratory function of rabbits with acute oleic acid-induced lung injury by inhibiting IL-6 expression and promoting IL-10 expression. PMID:25289065

  9. Complex Stapes Motions in Human Ears

    PubMed Central

    Chatzimichalis, Michail; Lauxmann, Michael; Röösli, Christof; Eiber, Albrecht; Huber, Alexander M.

    2010-01-01

    It has been reported that the physiological motion of the stapes in human and several animals in response to acoustic stimulation is mainly piston-like at low frequencies. At higher frequencies, the pattern includes rocking motions around the long and short axes of the footplate in human and animal ears. Measurements of such extended stapes motions are highly sensitive to the exact angulation of the stapes in relation to the measurement devices and to measurement errors. In this study, velocity in a specific direction was measured at multiple points on the footplates of human temporal bones using a Scanning Laser Doppler Vibrometer (SLDV) system, and the elementary components of the stapes motions, which were the piston-like motion and the rocking motions about the short and long axes of the footplate, were calculated from the measurements. The angular position of a laser beam with respect to the stapes and coordinates of the measurement points on the footplate plane were calculated by correlation between the SLDV measurement frame and the footplate-fixed frame, which was obtained from micro-CT images. The ratios of the rocking motions relative to the piston-like motion increased with frequency and reached a maximum around 7 kHz. A novel method for quantitatively assessing measurements of complex stapes motions and error boundaries of the motion components is presented. In the frequency range of 0.5 to 8 kHz, the magnitudes of the piston-like and two rocking motions were larger than estimated values of the corresponding upper error bounds. PMID:20165895

  10. 496. Phys. Lett A., 355, N4-5,(2006),247-249. A.G.Ramm, The shape of the ear The shape of the ear canal

    E-print Network

    2006-01-01

    496. Phys. Lett A., 355, N4-5,(2006),247-249. A.G.Ramm, The shape of the ear canal 1 #12;The shape of the ear canal A.G. Ramm Mathematics Department, Kansas State University, Manhattan, KS 66506-2602, USA ramm@math.ksu.edu Abstract It is proved that the measurement of the acoustic pressure on the ear

  11. Role of NADPH oxidase NOX5-S, NF-?B, and DNMT1 in acid-induced p16 hypermethylation in Barrett's cells

    PubMed Central

    Hong, Jie; Li, Dan; Wands, Jack; Souza, Rhonda

    2013-01-01

    Inactivation of tumor suppressor genes via promoter hypermethylation may play an important role in the progression from Barrett's esophagus (BE) to esophageal adenocarcinoma (EA). We have previously shown that acid-induced p16 gene promoter hypermethylation may depend on activation of NADPH oxidase NOX5-S in BAR-T cells and OE33 EA cells. DNA methyltransferase 1 (DNMT1) is known to participate in maintaining established patterns of DNA methylation in dividing cells and may play an important role in the development of cancer. Therefore, we examined whether DNMT1 is involved in acid-induced p16 gene promoter hypermethylation in BAR-T cells. We found that the acid significantly increased p16 gene promoter methylation, decreased p16 mRNA, and increased cell proliferation, effects that may depend on activation of DNMT1 in BAR-T cells. DNMT1 is overexpressed in EA cells FLO and OE33 and EA tissues. Acid treatment upregulated DNMT1 mRNA expression and increased DNMT1 promoter activity. Acid-induced increases in DNMT1 mRNA expression and promoter activity were significantly decreased by knockdown of NOX5-S and NF-?B1 p50. Conversely, overexpression of NOX5-S, p50, or p65 significantly increased DNMT1 promoter activity. Knockdown of NOX5-S significantly decreased the acid-induced increase in luciferase activity in cells transfected with pNF?B-Luc. An NF-?B binding element GGGGTATCCC was identified in the DNMT1 gene promoter. We conclude that the acid-induced increase in p16 gene promoter methylation, downregulation of p16 mRNA, and increase in cell proliferation may depend on activation of DNMT1 in BAR-T cells. Acid-induced DNMT1 expression may depend on sequential activation of NOX5-S and NF-?B1 p50. PMID:24025864

  12. Auditory Location in the Irrelevant Sound Effect: The Effects of Presenting Auditory Stimuli to Either the Left Ear, Right Ear or Both Ears

    ERIC Educational Resources Information Center

    Hadlington, Lee; Bridges, Andrew M.; Darby, Richard J.

    2004-01-01

    Two experiments used both irrelevant speech and tones in order to assess the effect of manipulating the spatial location of irrelevant sound. Previous research in this area had produced inconclusive results (e.g., Colle, 1980). The current study demonstrated a novel finding, that sound presented to the left ear produces the greatest level of…

  13. The aspirin metabolite sodium salicylate causes focal cerebral hemorrhage and cell death in rats with kainic acid-induced seizures.

    PubMed

    Najbauer, J; Schuman, E M; Mamelak, A N

    2000-01-01

    Aspirin (acetylsalicylic acid), and its main metabolite sodium salicylate, have been shown to protect neurons from excitotoxic cell death in vitro. The objective of our study was to investigate the possible neuroprotective effects of sodium salicylate in vivo in rats with kainic acid-induced seizures, a model for temporal lobe epilepsy in human patients. Male Sprague-Dawley rats received intraperitoneal injections of kainic acid either alone, or with sodium salicylate given before and for 40h after kainic acid injections. The control group received either phosphate-buffered saline or sodium salicylate without co-administration of kainic acid. Animals developed status epilepticus, which was aborted 1.5-2h later with diazepam. On day 3 following kainic acid-induced seizures, animals received bromodeoxyuridine to measure cellular proliferation, and were killed under anesthesia 24h later. Brains were removed, sectioned, and analysed for gross histological changes, evidence of hemorrhage, DNA fragmentation, cellular proliferation, and microglial immunohistochemistry. We report that sodium salicylate did not protect neurons from seizure-induced cell death, and to the contrary, it caused focal hemorrhage and cell death in the hippocampal formation and the entorhinal/piriform cortex of rats with kainic acid-induced seizures. Hemorrhage was never observed in animals that received vehicle, kainic acid or sodium salicylate only, which indicated that sodium salicylate exerted its effect only in animals with seizures, and was confined to select regions of the brain that undergo seizure activity. Large numbers of cells displaying DNA fragmentation were detected in the hippocampal formation, entorhinal/piriform cortex and the dorsomedial thalamic nucleus of rats that received kainic acid or kainic acid in combination with sodium salicylate. Bromodeoxyuridine immunohistochemistry revealed large numbers of proliferating cells in and around the areas with most severe neural injury induced by kainic acid or kainic acid co-administered with sodium salicylate. These same brain regions displayed intense staining with a microglia-specific marker, an indication of microglial activation in response to brain damage. In all cases, the degree of cell death, cell proliferation and microglia staining was more severe in animals that received the combination of kainic acid and sodium salicylate when compared to animals that received kainic acid alone. We hypothesize that our findings are attributable to sodium salicylate-induced blockade of cellular mechanisms that protect cells from calcium-mediated injury. These initial observations may have important clinical implications for patients with epilepsy who take aspirin while affected by these conditions, and should promote further investigation of this relationship. PMID:10924956

  14. Arachidonic acid induction of Rho-mediated transendothelial migration in prostate cancer

    PubMed Central

    Brown, M; Roulson, J-A; Hart, C A; Tawadros, T; Clarke, N W

    2014-01-01

    Background: Bone metastases in prostate cancer (CaP) result in CaP-related morbidity/mortality. The omega-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA) and lipophilic statins affect metastasis-like behaviour in CaP cells, regulating the critical metastatic step of CaP migration to the bone marrow stroma. Methods: Microscopic analysis and measurement of adhesion and invasion of CaP cells through bone marrow endothelial cells (BMEC) was undertaken with AA stimulation and/or simvastatin (SIM) treatment. Amoeboid characteristics of PC-3, PC3-GFP and DU-145 were analysed by western blotting and Rho assays. Results: The CaP cell lines PC-3, PC3-GFP and DU-145 share the ability to migrate across a BMEC layer. Specific amoeboid inhibition decreased transendothelial migration (TEM). AA stimulates amoeboid characteristics, driven by Rho signalling. Selective knock-down of components of the Rho pathway (RhoA, RhoC, Rho-associated protein kinase 1 (ROCK1) and ROCK2) showed that Rho signalling is crucial to TEM. Functions of these components were analysed, regarding adhesion to BMEC, migration in 2D and the induction of the amoeboid phenotype by AA. TEM was reduced by SIM treatment of PC3-GFP and DU-145, which inhibited Rho pathway signalling. Conclusions: AA-induced TEM is mediated by the induction of a Rho-driven amoeboid phenotype. Inhibition of this cell migratory process may be an important therapeutic target in high-risk CaP. PMID:24595005

  15. In vitro inhibition of arachidonic acid metabolism by two novel retinoid analogs.

    PubMed

    Fiedler-Nagy, C; Wittreich, B H; Carey, M A

    1989-06-01

    Ro 23-6457, (all-E)-3,7-dimethyl-9-[2-(trifluoromethyl)-6-(nonyloxy)phenyl]-2, 4,6,8- nonatetraenoic acid, and Ro 23-2895, (all-E)-9-[2-(nonyloxy)phenyl]-3,7-dimethyl-2,4,6,8-nonatetraen oic acid, are two novel retinoid analogs which exhibit antiinflammatory activity in both the developing and the established rat adjuvant arthritis models [8]. Here we investigated the effect of these two compounds on the production of arachidonic acid (AA) metabolites in two in vitro test systems [i.e., Ca2+ ionophore A23187 (I)-stimulated resident rat peritoneal macrophages (MO) and cytokine-stimulated human dermal fibroblasts (HDF)]. Both compounds, Ro 23-6457 and Ro 23-2895, significantly inhibited the release of 14C-AA metabolites and the production of LTB4, PGE2, and 6-keto-PGF1 alpha in I-stimulated MO, at concentrations of 1-33 microM. Both compounds also inhibited the production of PGE2 in HDF stimulated by either rhuIL-1 alpha or huTNF alpha at concentrations of 1 x 10(-5) to 1 x 10(-7) M. Ro 23-2895 was also a potent inhibitor of IL-1-induced collagenase production in rheumatoid synovial cells (IC50 approximately 1 to 2.5 x 10(-8) M). The inhibitory profile of these novel compounds in these cell systems is therefore similar to that of other known antiinflammatory retinoids (e.g., all-trans- and 13-cis-retinoic acid). Inhibitory effects such as those described here might in part contribute to the antiinflammatory activity of these compounds in vivo. PMID:2552763

  16. Stimulus-specific induction of phospholipid and arachidonic acid metabolism in human neutrophils

    PubMed Central

    1987-01-01

    Phospholipid remodeling resulting in arachidonic acid (AA) release and metabolism in human neutrophils stimulated by calcium ionophore A23187 has been extensively studied, while data obtained using physiologically relevant stimuli is limited. Opsonized zymosan and immune complexes induced stimulus-specific alterations in lipid metabolism that were different from those induced by A23187. [3H]AA release correlated with activation of phospholipase A2 (PLA2) but not with cellular activation as indicated by superoxide generation. The latter correlated more with calcium-dependent phospholipase C (PLC) activation and elevation of cellular diacylglycerol (DAG) levels. When cells that had been allowed to incorporate [3H]AA were stimulated with A23187, large amounts of labeled AA was released, most of which was metabolized to 5-HETE and leukotriene B4. Stimulation with immune complexes also resulted in the release of [3H]AA but this released radiolabeled AA was not metabolized. In contrast, stimulation with opsonized zymosan induced no detectable release of [3H]AA. Analysis of [3H]AA-labeled lipids in resting cells indicated that the greatest amount of label was incorporated into the phosphatidylinositol (PI) pool, followed closely by phosphatidylcholine and phosphatidylserine, while little [3H]AA was detected in the phosphatidylethanolamine pool. During stimulation with A23187, a significant decrease in labeled PI occurred and labeled free fatty acid in the pellet increased. With immune complexes, only a small decrease was seen in labeled PI while the free fatty acid in the pellets was unchanged. In contrast, opsonized zymosan decreased labeled PI, and increased labeled DAG. Phospholipase activity in homogenates from human neutrophils was also assayed. A23187 and immune complexes, but not zymosan, significantly enhanced PLA2 activity in the cell homogenates. On the other hand, PLC activity was enhanced by zymosan and immune complexes. Stimulated increases in PLC activity correlated with enhanced superoxide generation induced by the stimulus. PMID:3104352

  17. Inability of murine peritoneal macrophages to convert linoleic acid into arachidonic acid. Evidence of chain elongation

    SciTech Connect

    Chapkin, R.S.; Somers, S.D.; Erickson, K.L.

    1988-04-01

    Various murine macrophage populations synthesize and secrete large amounts of arachidonic acid (20:4n-6) derived eicosanoids (cyclo-oxygenase and lipoxygenase products). These metabolites are known to possess a wide variety of functions with regard to the initiation and regulation of inflammation and tumorigenesis. Because the dietary intake of 20:4n-6 is usually low, tissues are largely dependent upon dietary linoleic acid (18:2n-6) as an initial unsaturated precursor for the biosynthesis of 20:4n-6. The purpose of these experiments was to determine whether resident or responsive murine macrophages possess desaturase and elongase activities capable of in vitro conversion of 18:2n-6 into 20:4n-6. Peritoneal exudate macrophages were purified by adherence and incubated in serum-free medium containing fatty acid-free BSA with (1-14C) 18:2n-6. Approximately 90 to 98% of the (14C)18:2n-6 at 4 and 16 h was recovered in phosphatidylcholine and phosphatidylethanolamine. The metabolism of (14C)18:2n-6 was determined after transesterification and separation of the 14C-fatty acid methyl esters by argentation TLC, reverse phase HPLC, and electron impact gas chromatography/mass spectrometry. Resident and responsive macrophages lacked the capacity to transform (14C)18:2n-6 into 20:4n-6. In addition, prelabeled macrophages incubated with soluble, calcium ionophore A23187 or phorbol myristate, or particulate, zymosan, membrane perturbing agents also lacked delta 6 desaturase activity. All macrophages tested were capable of elongating (14C)18:2n-6 into (14C)20:2n-6. These observations suggest that 20:4n-6, present in macrophage phospholipids, is biosynthesized elsewhere and transported to the macrophage for esterification into the phospholipids. In addition, these findings demonstrate that elongase activity is present in both the resident and responsive peritoneal macrophage.

  18. Stimulus-specific induction of phospholipid and arachidonic acid metabolism in human neutrophils

    SciTech Connect

    Godfrey, R.W.; Manzi, R.M.; Clark, M.A.; Hoffstein, S.T.

    1987-04-01

    Phospholipid remodeling resulting in arachidonic acid (AA) release and metabolism in human neutrophils stimulated by calcium ionophore A23187 has been extensively studied, while data obtained using physiologically relevant stimuli is limited. Opsonized zymosan and immune complexes induced stimulus-specific alterations in lipid metabolism that were different from those induced by A23187. (/sup 3/H)AA release correlated with activation of phospholipase A2 (PLA2) but not with cellular activation as indicated by superoxide generation. The latter correlated more with calcium-dependent phospholipase C (PLC) activation and elevation of cellular diacylglycerol (DAG) levels. When cells that had been allowed to incorporate (/sup 3/H)AA were stimulated with A23187, large amounts of labeled AA was released, most of which was metabolized to 5-HETE and leukotriene B4. Stimulation with immune complexes also resulted in the release of (/sup 3/H)AA but this released radiolabeled AA was not metabolized. In contrast, stimulation with opsonized zymosan induced no detectable release of (/sup 3/H)AA. Analysis of (/sup 3/H)AA-labeled lipids in resting cells indicated that the greatest amount of label was incorporated into the phosphatidylinositol (PI) pool, followed closely by phosphatidylcholine and phosphatidylserine, while little (/sup 3/H)AA was detected in the phosphatidylethanolamine pool. During stimulation with A23187, a significant decrease in labeled PI occurred and labeled free fatty acid in the pellet increased. With immune complexes, only a small decrease was seen in labeled PI while the free fatty acid in the pellets was unchanged. In contrast, opsonized zymosan decreased labeled PI, and increased labeled DAG. Phospholipase activity in homogenates from human neutrophils was also assayed. A23187 and immune complexes, but not zymosan, significantly enhanced PLA2 activity in the cell homogenates. On the other hand, PLC activity was enhanced by zymosan and immune complexes. (Abstract Truncated)

  19. Absorption and metabolism of orally fed arachidonic and linoleic acid in the rat

    SciTech Connect

    Nilsson, A.; Melin, T. (Univ. of Lund (Sweden))

    1988-11-01

    ({sup 3}H)arachidonic (({sup 3}H)20:4) and ({sup 14}C)linoleic acid ({sup 14}C)18:2 were fed to rats in Intralipid or cream. Later (30-240 min) the stomach, small intestine, plasma, and liver were analyzed for radioactivity in different lipid classes. ({sup 3}H)20:4 and ({sup 14}C)18:2 were emptied from the stomach and absorbed by the intestine at similar rates. The ({sup 3}H)20:4:({sup 14}C)18:2 ratio of the lipids in the small intestinal wall increased, however, with time. This was due to a higher retention of ({sup 3}H)20:4 than ({sup 14}C)18:2 in intestinal phospholipids. In contrast, more of the ({sup 14}C)18:2 was in triacylglycerol of the small intestine and plasma. The highest {sup 3}H:{sup 14}C ratios were found in phosphatidylethanolamine and phosphatidylinositol. The {sup 3}H:{sup 14}C ratio of intestinal phosphatidylcholine varied with the type of fat vehicle used, being highest in the Intralipid experiments. After feeding Intralipid (30-60 min), significantly more of the plasma ({sup 3}H)20:4 than plasma ({sup 14}C)18:2 was in diacylglycerol, the {sup 3}H:{sup 14}C ratio of which was much higher than that of plasma free fatty acids. ({sup 3}H)20:4 and ({sup 14}C)18:2 of chyle triacylglycerol are thus metabolized differently.

  20. /sup 3/H arachidonic acid incorporation and metabolism in purified human basophils

    SciTech Connect

    Warner, J.A.; Peters, S.P.; Lichtenstein, L.M.; MacGlashan, D.W. Jr.

    1986-03-01

    A central feature of the allergic response is the generation of arachidonic acid (AA) metabolites by basophils and mast cells. In addition, AA metabolism may play a role in regulating the anti-IgE mediated degranulation of human basophils. To study this biochemistry, purified human basophils (>80%) were labeled with /sup 3/H-AA (0.3 ..mu..M, 25 ..mu..Ci/ml, 2 hours at 37/sup 0/C) and subsequently challenged with anti-IgE. Basophils were found to incorporate 45 +/- 3% of the exogenous AA which distributed into phospholipids (PL) (77.1 +/- 3.5%) and neutral lipids (19.7 +/- 3.3%) with only 5.3 +/- 2.7% remaining as the free acid (n = 7). Phosphatidylcholine (23.9 +/- 1.7%), phosphatidylinositol (22.0 +/- 1.4%) and phosphatidylethanolamine (14.5 +/- 2.7%) accounted for the majority of the AA with the remaining PL containing <3%. Anti-IgE (0.1 ..mu..g/ml) challenge led to the release of histamine (23.8 +/- 4.7%) and /sup 3/H-AA (8.1 +/- 1.7%) (n = 5). HPLC analysis revealed unmetabolized /sup 3/H-AA, /sup 3/H-LTC/sub 4/, /sup 3/H-HETE and an unidentified peak which migrated in the prostaglandin region of the elution profile. The same metabolites were released when the basophils were challenged with antigen. The calcium ionophore A23187 (1..mu..g/ml) also caused the release of histamine (37.4 +/- 4.1%) and /sup 3/H-AA (17.0 +/- 2.9%), while the phorbol ester, TPA caused HR (19.7 +/- 5.8%) but no increase in /sup 3/H AA turnover. Because of limited cell numbers this is the first time the authors have been able to study AA metabolism in human basophils.

  1. Arachidonic acid metabolism by bovine placental tissue during the last month of pregnancy

    SciTech Connect

    Hoedemaker, M.; Weston, P.G.; Wagner, W.C. (Univ. of Illinois, Urbana (USA))

    1991-01-01

    Conversion of tritiated arachidonic acid (AA) into metabolites of the cyclo- and lipoxygenase pathways by bovine fetal placental tissue (200 mg) and fetal plus maternal placental tissue (400 mg) of Days 255, 265, 275 of gestation and at parturition (n = 5) during a 30 min incubation was measured using reverse-phase high pressure liquid chromatography. Fetal placental tissue produced 13,14-dihydro-15-keto-prostaglandin E2 (PGEM) as the major metabolite, the synthesis of which increased from Day 265 to Day 275 and parturition by 150% and 475%, respectively. In tissues collected at parturition, PGE2 synthesis was also detected. On Day 275 and at parturition fetal placental tissue synthesized the metabolite 12-hydroxyheptadecatrienoic acid (HHT), and throughout the experimental period the lipoxygenase product 15-HETE was detected with synthesis rates increasing over time of gestation. In addition, an unidentified metabolite was regularly found in the radiochromatograms which eluted at 1 h and 1 min (U101), between HHT and 15-HETE. The synthesis of this metabolite decreased as pregnancy progressed. Furthermore, various other polar and nonpolar metabolites pooled under the heading UNID were eluted, the production of which increased over time of gestation. The presence of maternal placental tissue did not influence the synthesis of PGEM, 15-HETE and U101, but the production of HHT was decreased when maternal tissue was present. Also, as pregnancy progressed, maternal placental tissue seemed to contribute to the pool of unidentified metabolites. In conclusion, fetal placental tissue seems to be the major source of the AA metabolites when compared with maternal placental tissue, and AA metabolism by bovine placental tissue is markedly increased throughout the last month of pregnancy, suggesting a role for AA metabolites in mechanisms controlling parturition.

  2. Cannabinoid receptor binding and agonist activity of amides and esters of arachidonic acid.

    PubMed

    Pinto, J C; Potié, F; Rice, K C; Boring, D; Johnson, M R; Evans, D M; Wilken, G H; Cantrell, C H; Howlett, A C

    1994-09-01

    The cannabinoid receptor in brain (CB1) specifically binds delta 9-tetrahydrocannabinol, the predominant central nervous system-active component of marijuana. An eicosanoid found in brain, N-(2-hydroxyethyl)arachidonylamide (anandamide), binds to CB1 with similar affinity. This report considers structure-activity requirements for a series of novel amides and rigid hairpin conformations typified by N-(2-hydroxyethyl)prostaglandin amides, assayed with phenylmethylsulfonyl fluoride inactivation of esterases/amidases. Arachidonyl esters were 30-fold less potent than N-(2-hydroxyethyl)arachidonylamide, showing a rank order of potency of methyl = ethyl > propyl = isopropyl. Within the N-(hydroxyalkyl)arachidonylamide series, a one-carbon increase in chain length increased the potency 2-fold, but continued extension decreased affinity. Substituting the amide for the N-(2-hydroxyethyl)amide function produced a 4-fold loss of affinity. The N-(propyl)-, N-(butyl)-, and N-(benzyl)arachidonylamide derivatives exhibited a 3-fold increase, no change, and a 5-fold decrease, respectively, in affinity, compared with N-(2-hydroxyethyl)arachidonylamide. Both the methoxy ether and the formamide derivatives suffered > 20-fold loss of potency, compared with N-(2-hydroxyethyl)arachidonylamide. N-(2-Aminoethyl)arachidonylamide interacted poorly with CB1. At 100 microM, N-(2-hydroxyethyl)amide analogs of prostaglandin E2, A2, B2, and B1 failed to alter [3H]CP55940 binding to CB1. N-(2-Hydroxyethyl)arachidonylamide inhibited adenylate cyclase with lesser potency but with similar efficacy, compared with desacetyllevonantradol. Extending the length of the hydroxyalkyl moiety by one carbon increased the apparent potency by 1 order of magnitude. The N-(propyl) derivative exhibited a 5-fold greater potency than did the N-(2-hydroxyethyl) analog. It appears that the bulk and length of the moiety appended to arachidonic acid are more important determinants of affinity for CB1 than is hydrogen-bonding capability. PMID:7935333

  3. Enhancement of arachidonic acid signaling pathway by nicotinic acid receptor HM74A

    SciTech Connect

    Tang, Yuting [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States)]. E-mail: ytang@prdus.jnj.com; Zhou, Lubing [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Gunnet, Joseph W. [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Wines, Pamela G. [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Cryan, Ellen V. [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States); Demarest, Keith T. [Endocrine Therapeutics and Metabolic Disorders, Johnson and Johnson Pharmaceutical Research and Development, L.L.C., 1000 Rt. 202, Raritan, NJ 08869 (United States)

    2006-06-23

    HM74A is a G protein-coupled receptor for nicotinic acid (niacin), which has been used clinically to treat dyslipidemia for decades. The molecular mechanisms whereby niacin exerts its pleiotropic effects on lipid metabolism remain largely unknown. In addition, the most common side effect in niacin therapy is skin flushing that is caused by prostaglandin release, suggesting that the phospholipase A{sub 2} (PLA{sub 2})/arachidonic acid (AA) pathway is involved. Various eicosanoids have been shown to activate peroxisome-proliferator activated receptors (PPAR) that play a diverse array of roles in lipid metabolism. To further elucidate the potential roles of HM74A in mediating the therapeutic effects and/or side effects of niacin, we sought to explore the signaling events upon HM74A activation. Here we demonstrated that HM74A synergistically enhanced UTP- and bradykinin-mediated AA release in a pertussis toxin-sensitive manner in A431 cells. Activation of HM74A also led to Ca{sup 2+}-mobilization and enhanced bradykinin-promoted Ca{sup 2+}-mobilization through Gi protein. While HM74A increased ERK1/2 activation by the bradykinin receptor, it had no effects on UTP-promoted ERK1/2 activation.Furthermore, UTP- and bradykinin-mediated AA release was significantly decreased in the presence of both MAPK kinase inhibitor PD 098059 and PKC inhibitor GF 109203X. However, the synergistic effects of HM74A were not dramatically affected by co-treatment with both inhibitors, indicating the cross-talk occurred at the receptor level. Finally, stimulation of A431 cells transiently transfected with PPRE-luciferase with AA significantly induced luciferase activity, mimicking the effects of PPAR{gamma} agonist rosiglitazone, suggesting that alteration of AA signaling pathway can regulate gene expression via endogenous PPARs.

  4. Analysis of environmental-stress-related impairments of inner ear.

    PubMed

    Ohgami, Nobutaka; Iida, Machiko; Omata, Yasuhiro; Nakano, Chihiro; Wenting, Wu; Li, Xiang; Kato, Masashi

    2015-01-01

    Noise stress generated in industry is one of the environmental factors that physically affects the functions of the inner ear. Exposure to noise can cause hearing loss, resulting in serious problems in occupational and daily life. At present, however, there are very limited ways to prevent hearing impairments. The inner ear consists of the organ of Corti, vestibule and semicircular canal. Functional or morphological damage of these tissues in the inner ear caused by genetic factors, aging or environmental factors can result in hearing or balance impairments. In this review, we first introduce a deafness-related molecule found by our clinical research. Our experimental research using genetically engineered mice further demonstrated that impaired activity of the target molecule caused congenital and age-related hearing loss with neurodegeneration of spiral ganglion neurons in the inner ears. We also describe impaired balance in mice caused by exposure to low-frequency noise under experimental conditions with indoor environmental monitoring. We believe that our approaches to pursue both experimental research and fieldwork research complementarily are crucial for the development of a method for prevention of impairments of the inner ear. PMID:25994339

  5. An abbreviated history of the ear: from Renaissance to present.

    PubMed Central

    Hachmeister, Jorge E.

    2003-01-01

    In this article we discuss important discoveries in relation to the anatomy and physiology of the ear from Renaissance to present. Before the Renaissance, there was a paucity of knowledge of the anatomy of the ear, because of the relative inaccessibility of the temporal bone and the general perception that human dissections should not be conducted. It was not until the sixteenth century that the middle ear was described with detail. Further progress would be made between the sixteenth and eighteenth century in describing the inner ear. In the nineteenth century, technological advancement permitted a description of the cells and structures that constitute the cochlea. Von Helmholtz made further progress in hearing physiology when he postulated his resonance theory and later von Békésy when he observed a traveling wave in human cadavers within the cochlea. Brownell later made a major advance when he discovered that the ear has a mechanism for sound amplification, via outer hair cell electromotility. Images Figure 1 Figure 2 PMID:15369636

  6. Inner ear lesions in congenital cytomegalovirus infection of human fetuses.

    PubMed

    Teissier, Natacha; Delezoide, Anne-Lise; Mas, Anne-Elisabeth; Khung-Savatovsky, Suonavy; Bessières, Bettina; Nardelli, Jeannette; Vauloup-Fellous, Christelle; Picone, Olivier; Houhou, Nadira; Oury, Jean-François; Van Den Abbeele, Thierry; Gressens, Pierre; Adle-Biassette, Homa

    2011-12-01

    Congenital cytomegalovirus (CMV) infection is the leading cause of non-hereditary congenital sensorineural hearing loss (SNHL). The natural course and the pathophysiology of inner ear lesions during human fetal CMV infection have not yet been reported. Inner ear lesions were investigated in six CMV-infected fetuses aged 19-35 postconceptional weeks and correlated with central nervous system (CNS) lesions. All the fetuses had high viral loads in the amniotic fluid and severe visceral and CNS lesions visible by ultrasound. Diffuse lesions consisting of both cytomegalic cells containing inclusion bodies and inflammation were found within all studied structures including the inner ear, brain, other organs, and placenta, suggesting hematogenous dissemination. Cochlear infection was consistently present and predominated in the stria vascularis (5/6), whereas the supporting cells in the organ of Corti were less often involved (2/6). Vestibular infection, found in 4/6 cases, was florid; the non-sensory epithelia, including the dark cells, were extensively infected. The endolymphatic sac was infected in 1 of 3 cases. The severity of inner ear infection was correlated with the CNS lesions, confirming the neurotropism of CMV. This study documenting infection of the structures involved in endolymph secretion and potassium homeostasis in fetuses with high amniotic fluid viral loads suggests that potassium dysregulation in the endolymphatic compartment of the inner ear may lead to secondary degeneration of the sensory structures. In addition, the occurrence of SNHL depends on the intensity and duration of the viral infection and inflammation. PMID:22033878

  7. Acid-induced molten globule state of a prion protein: crucial role of Strand 1-Helix 1-Strand 2 segment.

    PubMed

    Honda, Ryo P; Yamaguchi, Kei-ichi; Kuwata, Kazuo

    2014-10-31

    The conversion of a cellular prion protein (PrP(C)) to its pathogenic isoform (PrP(Sc)) is a critical event in the pathogenesis of prion diseases. Pathogenic conversion is usually associated with the oligomerization process; therefore, the conformational characteristics of the pre-oligomer state may provide insights into the conversion process. Previous studies indicate that PrP(C) is prone to oligomer formation at low pH, but the conformation of the pre-oligomer state remains unknown. In this study, we systematically analyzed the acid-induced conformational changes of PrP(C) and discovered a unique acid-induced molten globule state at pH 2.0 termed the "A-state." We characterized the structure of the A-state using far/near-UV CD, 1-anilino-8-naphthalene sulfonate fluorescence, size exclusion chromatography, and NMR. Deuterium exchange experiments with NMR detection revealed its first unique structure ever reported thus far; i.e. the Strand 1-Helix 1-Strand 2 segment at the N terminus was preferentially unfolded, whereas the Helix 2-Helix 3 segment at the C terminus remained marginally stable. This conformational change could be triggered by the protonation of Asp(144), Asp(147), and Glu(196), followed by disruption of key salt bridges in PrP(C). Moreover, the initial population of the A-state at low pH (pH 2.0-5.0) was well correlated with the rate of the ?-rich oligomer formation, suggesting that the A-state is the pre-oligomer state. Thus, the specific conformation of the A-state would provide crucial insights into the mechanisms of oligomerization and further pathogenic conversion as well as facilitating the design of novel medical chaperones for treating prion diseases. PMID:25217639

  8. Plasmenylethanolamine is the major storage depot for arachidonic acid in rabbit vascular smooth muscle and is rapidly hydrolyzed after angiotensin II stimulation

    SciTech Connect

    Ford, D.A.; Gross, R.W. (Washington Univ., St. Louis, MO (USA))

    1989-05-01

    The present study demonstrates that rabbit aortic intimal smooth muscle cells contain the majority of their endogenous arachidonic acid mass in plasmenylethanolamine molecular species. To demonstrate the potential significance of these plasmenylethanolamines as substrates for the smooth muscle cell phospholipases that are activated during agonist stimulation, aortic rings were prelabeled with ({sup 3}H)arachidonic acid and stimulated with angiotensin II. Although the specific activities of the choline and inositol glycerophospholipid pools were similar after the labeling interval, ethanolamine glycerophospholipids had a specific activity of only 20% of the specific activity of choline and inositol glycerophospholipids. Despite the marked disparity in the specific activities of these three phospholipid classes, angiotensin II stimulation resulted in similar fractional losses (35-41%) of ({sup 3}H)arachidonic acid from vascular smooth muscle choline, ethanolamine, and inositol glycerophospholipid classes. Reverse-phase HPLC demonstrated that >60% of the ({sup 3}H)arachidonic acid released from ethanolamine glycerophospholipids after angiotensin II stimulation originated from plasmenylethanolamine molecular species. Taken together, the results demonstrate that the major phospholipid storage depot for arachidonic acid in vascular smooth muscle cells are plasmenylethanolamine molecular species which are important substrates for the phospholipase(s) that are activated during agonist stimulation.

  9. Release of arachidonate from membrane phospholipids in cultured neonatal rat myocardial cells during adenosine triphosphate depletion. Correlation with the progression of cell injury.

    PubMed Central

    Chien, K R; Sen, A; Reynolds, R; Chang, A; Kim, Y; Gunn, M D; Buja, L M; Willerson, J T

    1985-01-01

    The present study utilized a cultured myocardial cell model to evaluate the relationship between the release of arachidonate from membrane phospholipids, and the progression of cell injury during ATP depletion. High-energy phosphate depletion was induced by incubating cultured neonatal rat myocardial cells with various combinations of metabolic inhibitors (deoxyglucose, oligomycin, cyanide, and iodoacetate). Phospholipid degradation was assessed by the release of radiolabeled arachidonate from membrane phospholipids. In this model, the current study demonstrates that (a) cultured myocardial cells display a time-dependent progression of cell injury during ATP depletion; (b) the morphologic patterns of mild and severe cell injury in the cultured cells are similar to those found in intact ischemic canine myocardial models; (c) cultured myocardial cells release arachidonate from membrane phospholipids during ATP depletion; and (d) using two separate combinations of metabolic inhibitors, there is a correlation between the release of arachidonate, the development of severe cellular and sarcolemmal damage, the release of creatine kinase into the extracellular medium, and the loss of the ability of the myocardial cells to regenerate ATP when the metabolic inhibitors are removed. Thus, the present results suggest that during ATP depletion, in cultured neonatal rat myocardial cells, the release of arachidonate from myocardial membrane phospholipids is linked to the development of membrane defects and the associated loss of cell viability. Images PMID:3924955

  10. Soft tissue attenuation in middle ear on HRCT: Pictorial review

    PubMed Central

    Anbarasu, Arangasamy; Chandrasekaran, Kiruthika; Balakrishnan, Sivasubramanian

    2012-01-01

    Middle ear disease is a common clinical entity; imaging, especially High resolution Computed Tomography (HRCT), plays a crucial role in diagnosis and assessing the disease extent, helping to decide appropriate management. Temporal bone imaging is challenging and involves thorough understanding of the anatomy, especially in relation to HRCT imaging. Most of the middle ear pathologies appear as “soft tissue” on imaging. Careful analysis of the soft tissue on the HRCT is crucial in achieving the right diagnosis; clinical information is essential and the imaging findings need correlation with clinical presentation and otoscopic findings. The purpose of this pictorial essay is to enlist the pathologies that present as soft tissue in middle ear and to provide a structured and practical imaging approach that will serve as a guide for confident reporting in daily practice. PMID:23833422

  11. MicroRNA expression in the embryonic mouse inner ear.

    PubMed

    Wang, Xian-Ren; Zhang, Xue-Mei; Zhen, Jing; Zhang, Pen-Xing; Xu, Geng; Jiang, Hongyan

    2010-06-23

    Although microRNA (miRNA) is expressed extensively in the postnatal mouse inner ear, its expression in the sensory epithelium during embryogenesis has not been well characterized. We investigated miRNA expression at E13.5 and E16.5 by microarray analysis, quantitative real-time-PCR, and in-situ hybridization. MiRNA-182, miRNA-140, miRNA-200c, and others showed distinct temporal and spatial expression patterns. MiRNA-194, whose expression in zebrafish seems to play an important role in the differentiation of the intestinal epithelium, was also expressed in the spiral ganglia of the mouse inner ear, where it may play a similar role in neuronal differentiation. Our results indicate that miRNAs are widely expressed in the developing inner ear, with more species recruited as hair cells differentiate, suggesting an important developmental role. PMID:20467336

  12. Performance analysis of the Ormia ochracea's coupled ears.

    PubMed

    Akcakaya, Murat; Nehorai, Arye

    2008-10-01

    The Ormia ochracea is able to locate a cricket's mating call despite the small distance between its ears compared with the wavelength. This phenomenon has been explained by the mechanical coupling between the ears. In this paper, it is first shown that the coupling enhances the differences in times of arrival and frequency responses of the ears to the incoming source signals. Then, the accuracy of estimating directions of arrival (DOAs) by the O. ochracea is analyzed by computing the Cramér-Rao bound (CRB). The differential equations of the mechanical model are rewritten in state space and its frequency response is calculated. Using the spectral properties of the system, the CRB for multiple stochastic sources with unknown directions and spectra is asymptotically computed. Numerical examples compare the CRB for the coupled and the uncoupled cases, illustrating the effect of the coupling on reducing the errors in estimating the DOAs. PMID:19062851

  13. Human Action Recognition Using Wireless Wearable In-Ear Microphone

    NASA Astrophysics Data System (ADS)

    Nishimura, Jun; Kuroda, Tadahiro

    To realize the ubiquitous eating habits monitoring, we proposed the use of sounds sensed by an in-ear placed wireless wearable microphone. A prototype of wireless wearable in-ear microphone was developed by utilizing a common Bluetooth headset. We proposed a robust chewing action recognition algorithm which consists of two recognition stages: “chew-like” signal detection and chewing sound verification stages. We also provide empirical results on other action recognition using in-ear sound including swallowing, cough, belch, and etc. The average chewing number counting error rate of 1.93% is achieved. Lastly, chewing sound mapping is proposed as a new prototypical approach to provide an additional intuitive feedback on food groups to be able to infer the eating habits in their daily life context.

  14. Influences on clinical practice: the case of glue ear

    PubMed Central

    Dopson, S.; Miller, R.; Dawson, S.; Sutherland, K.

    1999-01-01

    A case study of clinical practice in children with glue ear is presented. The case is part of a larger project, funded by the North Thames Research and Development Programme, that sought to explore the part played by clinicians in the implementation of research and development into practice in two areas: adult asthma and glue ear in children. What is striking about this case is the differences found in every area of the analysis. That is, diversity was found in views about diagnosis and treatment of glue ear; the organisation of related services; and in the reported practice of our interviewees, both between particular groupings of clinical staff and within these groupings. The challenge inherent in the case is to go beyond describing the complexity and differences that were found, and look for patterns in the accounts of practice and tease out why such patterns may occur. PMID:10557674

  15. Regeneration of the mammalian inner ear sensory epithelium

    PubMed Central

    Wei, Dongguang; Yamoah, Ebenezer N.

    2010-01-01

    Purpose of Review This review will focus on “self-repair” of mammalian inner ear sensory epithelium including (1) recruiting the in situ proliferation and differentiation of endogenous cells at the damaged site and (2) the autologous transplantation Recent findings Self-repair refers to a favorable structural and functional outcome of damaged inner ear sensory epithelium. Our advanced ability of manipulating the fate of inner ear sensory cells makes in situ proliferation a possible candidate of hearing restoration. A practical alternative of the unavoidable immune rejection is to introduce autologous cells. Ependymal cells, induced pluripotent stem (iPS) cells, and olfactory sheath cells have been recognized as promising sources, which will spur ongoing efforts to evaluate the new cell sources for cell replacement therapy. Summary Further exploration of the innate advantages of in situ proliferation and using novel cell sources for autologous transplantation may serve as rehearsals for clinical trials in the near future. PMID:19617827

  16. Magnetically driven middle ear ossicles for optical measurement of vibrations in an ear with opened tympanic membrane.

    PubMed

    Peacock, J; von Unge, M; Dirckx, J

    2013-12-01

    Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, laser vibrometry requires free visual access to the object under investigation, and acquiring free visual access to the ossicles through the ear canal requires the removal of the tympanic membrane (TM), with the result that the ossicles can no longer be stimulated acoustically. To overcome this, we devised a new setup in which the ossicles can be driven magnetically. After measuring the response of the TM to an acoustic signal, we then remove it and attach a small magnet to the exposed manubrium (a part of the most lateral auditory ossicle, the malleus, which is normally attached to the TM). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a setup may have uses in research on middle ear mechanics, such as the measurement of nonlinearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis or in chronic otitis media. We describe our setup and discuss the viability of our method and its future clinical potential by presenting some measurements on an artificially fixated ear. PMID:24387412

  17. Magnetically driven middle ear ossicles for optical measurement of vibrations in an ear with opened tympanic membrane

    NASA Astrophysics Data System (ADS)

    Peacock, J.; von Unge, M.; Dirckx, J.

    2013-12-01

    Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, laser vibrometry requires free visual access to the object under investigation, and acquiring free visual access to the ossicles through the ear canal requires the removal of the tympanic membrane (TM), with the result that the ossicles can no longer be stimulated acoustically. To overcome this, we devised a new setup in which the ossicles can be driven magnetically. After measuring the response of the TM to an acoustic signal, we then remove it and attach a small magnet to the exposed manubrium (a part of the most lateral auditory ossicle, the malleus, which is normally attached to the TM). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a setup may have uses in research on middle ear mechanics, such as the measurement of nonlinearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis or in chronic otitis media. We describe our setup and discuss the viability of our method and its future clinical potential by presenting some measurements on an artificially fixated ear.

  18. Liquid Chromatographic–Electrospray Ionization–Mass Spectrometric Analysis of Cytochrome P450 Metabolites of Arachidonic Acid

    Microsoft Academic Search

    Kasem Nithipatikom; Andrew J. Grall; Blythe B. Holmes; David R. Harder; John R. Falck; William B. Campbell

    2001-01-01

    Arachidonic acid (AA) can be metabolized by cytochrome P450 (CYP) enzymes to many biologically active compounds including 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs), their corresponding dihydroxyeicosatrienoic acids (DHETs), and 20-hydroxyeicosatetraenoic acid (20-HETE). These eicosanoids are potent regulators of vascular tone. We developed a liquid chromatography–electrospray ionization–mass spectrometry method to simultaneously determine 5,6-, 8,9-, 11,12-, and 14,15-EETs; 5,6-, 8,9-, 11,12-,

  19. Ion Channel Gene Expression in the Inner Ear

    PubMed Central

    Sokolowski, Bernd H.A.; Morton, Cynthia C.; Giersch, Anne B.S.

    2007-01-01

    The ion channel genome is still being defined despite numerous publications on the subject. The ion channel transcriptome is even more difficult to assess. Using high-throughput computational tools, we surveyed all available inner ear cDNA libraries to identify genes coding for ion channels. We mapped over 100,000 expressed sequence tags (ESTs) derived from human cochlea, mouse organ of Corti, mouse and zebrafish inner ear, and rat vestibular end organs to Homo sapiens, Mus musculus, Danio rerio, and Rattus norvegicus genomes. A survey of EST data alone reveals that at least a third of the ion channel genome is expressed in the inner ear, with highest expression occurring in hair cell-enriched mouse organ of Corti and rat vestibule. Our data and comparisons with other experimental techniques that measure gene expression show that every method has its limitations and does not per se provide a complete coverage of the inner ear ion channelome. In addition, the data show that most genes produce alternative transcripts with the same spectrum across multiple organisms, no ion channel gene variants are unique to the inner ear, and many splice variants have yet to be annotated. Our high-throughput approach offers a qualitative computational and experimental analysis of ion channel genes in inner ear cDNA collections. A lack of data and incomplete gene annotations prevent both rigorous statistical analyses and comparisons of entire ion channelomes derived from different tissues and organisms. Electronic supplementary material The online version of this article (doi:10.1007/s10162-007-0082-y) contains supplementary material, which is available to authorized users. PMID:17541769

  20. Eustachian tube function in patients with inner ear disorders.

    PubMed

    Park, Jonas J-H; Luedeke, Inger; Luecke, Kerstin; Emmerling, Oliver; Westhofen, Martin

    2013-05-01

    The influence of Eustachian tube (ET) dysfunction on the inner ear fluid pressure and thus on the inner ear function in Meniere's disease has been discussed controversially. So far, most of the studies examining ET function in inner ear disorders indirectly analyzed ET function by tympanometric methods. The present study directly studied ET function in inner ear disorders by sonotubometry. Healthy subjects and patients with Meniere's disease, sudden sensorineural hearing loss, cholesteatoma and chronic suppurative otitis media were examined by sonotubometry. Mean increase of sound pressure intensity (dB) and mean duration of sound pressure increase (s) were analyzed. Highest mean increase of sound pressure intensity was seen in healthy subjects when using >5 dB peaks (11.6 ± 0.7 dB) and >0 dB peaks (9.6 ± 0.6 dB). Comparative analysis including bilateral ears showed decreased ET function in patients with cholesteatoma (p = 0.002) and in patients with Meniere's disease (p = 0.003) when using >0 dB peaks. Examination of each specific ET opening maneuver showed impaired ET function in pathological ears of patients with cholesteatoma and with Meniere's disease, during yawning (p = 0.001; p < 0.001), dry swallowing (p = 0.010; p = 0.049), Toynbee maneuver (p = 0.033; p = 0.032) and drinking (p = 0.044; p = 0.027). Mild ET dysfunction is detected in patients with Meniere's disease by direct sonotubometric assessment of ET function. PMID:22941437

  1. [Clinical experience with silastic middle-ear prostheses].

    PubMed

    Zelený, M; Voldrich, Z

    1989-01-01

    The authors made clinical tests of silastic prostheses of the middle ear, type PORP, TORP and piston. They used 29 X PORP, 26 X TORP and 21 pistons. They did not reveal any signs of tissue intolerance to Silastic MDX 44-516, which is used for making prostheses. They achieved satisfactory anatomical and functional results. They recorded an auditory gain in more than half the patients (early: PORP 97%, TORP 73%, piston 52%; plasty transplants of ossicles obtained from subjects who died accidentally? For preserfic Council of the Ministry of Health, Czech Socialist Republic, recommended, based on the clinical tests, the manufacture of silastic prostheses of the middle ear. PMID:2540918

  2. Inner ear supporting cells: Rethinking the silent majority

    PubMed Central

    Wan, Guoqiang; Corfas, Gabriel; Stone, Jennifer S

    2014-01-01

    Sensory epithelia of the inner ear contain two major cell types: hair cells and supporting cells. It has been clear for a long time that hair cells play critical roles in mechanoreception and synaptic transmission. In contrast, until recently the more abundant supporting cells were viewed primarily as serving primarily structural and homeostatic functions. In this review we discuss the growing information about the roles that supporting cells play in the development, function and maintenance of the inner ear, their activities in pathological states, their potential for hair cell regeneration, and the mechanisms underlying these processes. PMID:23545368

  3. Energy localization and frequency analysis in the locust ear.

    PubMed

    Malkin, Robert; McDonagh, Thomas R; Mhatre, Natasha; Scott, Thomas S; Robert, Daniel

    2014-01-01

    Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami-like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization. PMID:24196693

  4. Pathologic conditions of the external ear and auditory canal.

    PubMed

    Ostrowski, V B; Wiet, R J

    1996-09-01

    Primary care physicians are influential in diagnosing and initiating treatment of most pathologic conditions in patients with a history of hearing loss, chronic ear infection, diabetes, immunosuppression, or otologic symptoms with excessive exposure to sunlight. Lesions of the external ear and the external auditory canal (external acoustic meatus) are significant and common. Patients with such a history should have a thorough basic examination, which can be done with simple tools. Symptoms of hearing loss, otalgia, otorrhea, tinnitus, aural fullness, vertigo, and facial weakness may warrant referral of the patient to an otolaryngologist. The crux of preventing worsening otologic sequelae is early detection and treatment. PMID:8795656

  5. Energy localization and frequency analysis in the locust ear

    PubMed Central

    Malkin, Robert; McDonagh, Thomas R.; Mhatre, Natasha; Scott, Thomas S.; Robert, Daniel

    2014-01-01

    Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami-like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization. PMID:24196693

  6. Temporomandibular joint disorder and inner ear pruritus: resolution by eminectomy.

    PubMed

    Pentyala, Sahana; Mysore, Pooja; Moller, Daryn; Pentyala, Srinivas; Kardovich, Richard; Martino, Andrew; Proothi, Michael

    2014-09-01

    Recurrent dislocation of the temporomandibular joint (TMJ) disk is caused by many factors. Dislocation can result in an acute or chronic closed lock condition. Temporomandibular joint dysfunction is often presented with otalgia symptoms. Other aural symptoms such as deafness, tinnitus, pressure/blockage, and vertigo are also commonly presented together with TMJ dysfunction (Clin Otolaryngol Allied Sci. 1980;5:23-36). However, pruritus associated with TMJ dysfunction in the inner ear has never been reported in the literature. We report a case history of TMJ dysfunction and associated inner ear pruritus, which are both resolved by eminectomy. PMID:25072971

  7. The bile acid-inducible baiF gene from Eubacterium sp. strain VPI 12708 encodes a bile acid-coenzyme

    Microsoft Academic Search

    Darrell H. Mallonee; James E. Wells; Ingemar Björkhem; Phillip B. Hylemon

    The human intestinal Eubacterium sp. strain VPI 12708 has been shown to have a multistep biochemical path- way for bile acid 7 a -dehydroxylation. A bile acid-inducible operon encoding 9 open reading frames has been cloned and sequenced from this organism. Several of the genes in this operon have been shown to catalyze specific reactions in the 7 a -dehydroxylation

  8. Regulation of macrophage-derived fibroblast growth factor release by arachidonate metabolites.

    PubMed

    Phan, S H; McGarry, B M; Loeffler, K M; Kunkel, S L

    1987-08-01

    The macrophage is a source of many mediators with direct and indirect fibrogenic potential. In this study, release of macrophage-derived fibroblast growth factor (MDGF) activity by murine peritoneal macrophages is examined with regard to its regulation by arachidonate metabolites. Upon stimulation with 10 micrograms/ml lipopolysaccharide (LPS), resident peritoneal macrophages from CBA/J mice released MDGF activity into media rapidly, reaching maximal levels in approximately 1 h. Lysates of these stimulated cells also revealed significantly increased cell-associated MDGF activity, composing 45% of the total assayable activity. This activity, as assayed by radioactive thymidine incorporation by primary cultures of rat lung fibroblasts, was separable from interleukin-1 (IL-1) activity by reverse phase high performance liquid chromatography (HPLC). Furthermore, purified murine IL-1 had no MDGF activity in this assay system. This stimulated MDGF release was enhanced by the cyclooxygenase inhibitors indomethacin, ibuprofen, and aspirin at micromolar concentrations, but inhibited in a dose-dependent manner by prostaglandin E2 (PGE2). On the other hand, nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor was inhibitory at 0.1 and 0.4 microM but not at 2.5 microM. Zymosan-stimulated macrophages also markedly increased MDGF release, albeit with a different time course which was characterized by a delay of approximately 7 h before peak levels were attained. Such stimulation, which is known to cause increased lipoxygenase activity, was also inhibited by 0.5 microM NDGA. In contrast, the lipoxygenase pathway products leukotrienes B4 (LTB4) and C4 (LTC4) stimulated MDGF release in a dose-dependent (10(-10)-10(-8) M) manner, with LTC4 being more potent on a per unit dose basis. Stimulation by LTC4 was inhibited by the putative leukotriene receptor antagonist, FPL55712, while LTD4 and LTE4 did not stimulate MDGF release, thus suggesting the mediation of this effect by specific LTC4 receptors. These data suggest also that products of the cyclooxygenase and lipoxygenase pathways are potentially important both as exogenous (ie, derived from cells other than the macrophage itself) and auto- or self-regulators of macrophage MDGF release. This, in turn, implies that cyclooxygenase products are antifibrogenic and important in maintaining or returning to the quiescent or normal state, whereas the lipoxygenase products are profibrogenic and important in induction of fibrosis or wound-healing and tissue repair. Any alteration in the balance between these two pathways may result in either a desirable or a harmful outcome. PMID:3036988

  9. Regulation of the arachidonic acid mobilization in macrophages by combustion-derived particles

    PubMed Central

    2011-01-01

    Background Acute exposure to elevated levels of environmental particulate matter (PM) is associated with increasing morbidity and mortality rates. These adverse health effects, e.g. culminating in respiratory and cardiovascular diseases, have been demonstrated by a multitude of epidemiological studies. However, the underlying mechanisms relevant for toxicity are not completely understood. Especially the role of particle-induced reactive oxygen species (ROS), oxidative stress and inflammatory responses is of particular interest. In this in vitro study we examined the influence of particle-generated ROS on signalling pathways leading to activation of the arachidonic acid (AA) cascade. Incinerator fly ash particles (MAF02) were used as a model for real-life combustion-derived particulate matter. As macrophages, besides epithelial cells, are the major targets of particle actions in the lung murine RAW264.7 macrophages and primary human macrophages were investigated. Results The interaction of fly ash particles with macrophages induced both the generation of ROS and as part of the cellular inflammatory responses a dose- and time-dependent increase of free AA, prostaglandin E2/thromboxane B2 (PGE2/TXB2), and 8-isoprostane, a non-enzymatically formed oxidation product of AA. Additionally, increased phosphorylation of the mitogen-activated protein kinases (MAPK) JNK1/2, p38 and ERK1/2 was observed, the latter of which was shown to be involved in MAF02-generated AA mobilization and phosphorylation of the cytosolic phospolipase A2. Using specific inhibitors for the different phospolipase A2 isoforms the MAF02-induced AA liberation was shown to be dependent on the cytosolic phospholipase A2, but not on the secretory and calcium-independent phospholipase A2. The initiation of the AA pathway due to MAF02 particle exposure was demonstrated to depend on the formation of ROS since the presence of the antioxidant N-acetyl-cysteine (NAC) prevented the MAF02-mediated enhancement of free AA, the subsequent conversion to PGE2/TXB2 via the induction of COX-2 and the ERK1/2 and JNK1/2 phosphorylation. Finally we showed that the particle-induced formation of ROS, liberation of AA and PGE2/TXB2 together with the phosphorylation of ERK1/2 and JNK1/2 proteins was decreased after pre-treatment of macrophages with the metal chelator deferoxamine mesylate (DFO). Conclusions These results indicate that one of the primary mechanism initiating inflammatory processes by incinerator fly ash particles seems to be the metal-mediated generation of ROS, which triggers via the MAPK cascade the activation of AA signalling pathway. PMID:21810225

  10. Interaction of dimethylsulfoxide and arachidonic acid with the teratogenic effects of caffeine in mice.

    PubMed

    Reddy, R V; Reddy, C S; Frappier, B L; Brimer, G E; Fraipier, B L

    1994-01-01

    Dose-response of the teratogenic effect of caffeine (CA) and the potential role of facial hematomas in the pathogenesis of caffeine-induced cleft palate were investigated using CD1 mice treated with 150, 200, or 250 mg CA/kg i.p. on gestational day (GD) 12. Dimethylsulfoxide (DMSO; 20%) and arachidonic acid (AA, 200 mg/kg) were administered along with CA (200 mg/kg) to study their interaction with CA-induced teratogenesis and elevation in maternal glucocorticoids (MGC, measured by RIA) on GD 13 and 14. Dose-dependent increase in the incidence of cleft palate (CP) was noted in CA-exposed mice. High maternal deaths, an increased number of resorptions, gross facial hematomas (GFH), and club foot (CF) were produced only by the highest (250 mg/kg) dose of CA. Palates from all offspring with GFH were clefted at this dose level. None of the control or CA-treated nonclefted offspring had GFH or microscopic hematomas (MH). At 200 mg/kg of CA, DMSO in combination with CA actually increased CA-induced CP from 30% to 100% and also produced 100% GFH as compared to 0% by CA alone at this dose. Greater than 50% of clefted offspring without GFH, given either dose (200 or 250 mg/kg) of CA, had MH. Very high levels of MGC were present in CA-treated mice on GD 13 and 14. Although simultaneous administration of DMSO reduced the magnitude of CA-induced MGC elevations on GD 14, the MGC levels remained high for greater than 24 hours following CA exposure. Increase in maternal mortality and fetal resorptions, a decrease in the number of live pups and their body weights, and no change in the incidence of CP were seen when CA-treated mice were simultaneously exposed to AA. These results suggest a correlation between caffeine-induced FH and CP; a role for increased hematomagenic effects of DMSO in its potentiation of the cleft-palatogenic effect of caffeine; and absence of a role for AA-mediated effects of MGC in the causation of CA-induced CP and other malformations. PMID:8032692

  11. Arachidonic acid-activated Na+-dependent Mg2+ efflux in rat renal epithelial cells.

    PubMed

    Ikari, Akira; Nakajima, Kumiko; Suketa, Yasunobu; Harada, Hitoshi; Takagi, Kuniaki

    2003-12-01

    Arachidonic acid (AA), a metabolite of membrane phospholipids, and its metabolites are increased in Mg2+ deficiency. We examined whether the extracellular Mg2+ concentration affects AA production and whether AA regulates a putative Na+-dependent Mg2+ efflux pathway in renal epithelial NRK-52E cells. We used the cells cultured in 5 mM Mg2+-containing medium for 2 days because they enable us to detect Na+-stimulated Mg2+ efflux that was not observed in normal culture medium. Removal of extracellular Mg2+ increased AA release both in the absence and presence of extracellular Na+. This was inhibited by methyl arachidonyl fluorophosphonate (MAFP, 10 microM), an inhibitor of cytosolic phospholipase A) (cPLA2) and Ca2+-independent phospholipase A2 (iPLA2), and bromoenol lactone (BEL, 10 microM), an inhibitor of iPLA2. However, LY-311727 (10 microM), a secretory phospholipase A2 (sPLA2) inhibitor, had no inhibitory effect. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed that NRK-52E cells express cPLA2 and iPLA2 mRNAs, but not sPLA2. In the mag-fura 2 fluorescence measurements, extracellular Mg2+ removal caused slight decrease in the intracellular free Mg2+ concentration ([Mg2+]i) in the Na+-free condition. The addition of Na+ caused a rapid decrease in [Mg2+]i, indicating the presence of a Na+-dependent Mg2+ efflux pathway. The Na+-dependent [Mg2+]i decrease was suppressed by MAFP and BEL. On the other hand, AA metabolite inhibitors, nordihydroguaiaretic acid (NDGA) (50 microM), indomethacin (10 microM) and 17-octadecynoic acid (ODYA) (10 microM), enhanced the Na+-dependent [Mg2+]i decrease. Furthermore, the addition of exogenous AA (30 microM) enhanced the Na+-dependent [Mg2+]i decrease, which was significantly inhibited by imipramine (0.1 mM), a putative Na+/Mg2+-exchanger inhibitor. These results suggest that extracellular Mg2+ removal elevates AA release mediated mainly by iPLA2 and that AA upregulates the Na+-dependent Mg2+ efflux in NRK-52E cells. PMID:14643927

  12. Dietary coconut oil increases conjugated linoleic acid-induced body fat loss in mice independent of essential fatty acid deficiency.

    PubMed

    Hargrave, Kimberly M; Azain, Michael J; Miner, Jess L

    2005-10-15

    Conjugated linoleic acid (CLA) induces a body fat loss that is enhanced in mice fed coconut oil (CO), which lacks essential fatty acids (EFA). Our objective was to determine if CO enhancement of CLA-induced body fat loss is due to the lack of EFA. The CLA-EFA interaction was tested by feeding CO and fat free (FF) diets for varying times with and without replenishment of individual EFA. Mice fed CO during only the 2-week CLA-feeding period did not differ from control mice in their adipose EFA content but still tended (P=0.06) to be leaner than mice fed soy oil (SO). Mice raised on CO or FF diets and fed CLA were leaner than the SO+CLA-fed mice (P<0.01). Mice raised on CO and then replenished with linoleic, linolenic, or arachidonic acid were leaner when fed CLA than mice raised on SO (P<0.001). Body fat of CO+CLA-fed mice was not affected by EFA addition. In summary, CO-fed mice not lacking in tissue EFA responded more to CLA than SO-fed mice. Also, EFA addition to CO diets did not alter the enhanced response to CLA. Therefore, the increased response to CLA in mice raised on CO or FF diets appears to be independent of a dietary EFA deficiency. PMID:16216548

  13. Docosahexaenoic acid induces proteasome-dependent degradation of estrogen receptor ? and inhibits the downstream signaling target in MCF7 breast cancer cells

    Microsoft Academic Search

    I-Fen Lu; Ann-Che Hasio; Meng-Chun Hu; Feng-Ming Yang; Hui-Min Su

    2010-01-01

    About two thirds of breast cancers in women are hormone-dependent and require estrogen for growth, its effects being mainly mediated through estrogen receptor ? (ER?). Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) have opposite effects on carcinogenesis, with DHA suppressing and AA promoting tumor growth both in vitro and in vivo. However, the mechanism is not clear. Here,

  14. Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes

    SciTech Connect

    Punnonen, K.; Puustinen, T.; Jansen, C.T.

    1986-02-01

    Human keratinocytes in culture were labelled with /sup 14/C-dihomo-gamma-linolenic acid, /sup 14/C-arachidonic acid or /sup 14/C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.

  15. A phospholipase A2 isoenzyme provokes lipoxin B formation from endogenous sources of arachidonic acid in porcine leukocytes.

    PubMed

    Lam, B K; Serhan, C N; Samuelsson, B; Wong, P Y

    1987-04-14

    Porcine leukocytes incubated with an isoenzyme of phospholipase A2 (PLA2) (isolated from snake venom) produced several trihydroxytetraene- containing compounds which were derived from endogenous sources of arachidonic acid. The formation of these compounds was dose-dependent with an EC50 of approximately 1.25 X 10(-8) M. At this concentration of the isoenzyme and time of exposure the cells remained viable as determined by the exclusion of trypan blue. The compounds were purified by HPLC and their identities were determined by physical criteria which included U.V. spectrometry, GC/MS and by comparison with both synthetic and authentic materials. The biologically derived compounds proved to be lipoxin B (5S, 14R, 15S-trihydroxy-6, 10, 12-trans-8-cis-eicosatetraenoic acid) and its two structural isomers (8-trans-LXB and 14S-8-trans-LXB). Of interest, only small amounts of lipoxin A and its isomers were found in these incubations. Results of the present study indicate that porcine leukocytes can generate lipoxin B and its isomers from endogenous sources of arachidonic acid. Moreover, they suggest that certain PLA2 isoenzymes may initiate the formation of lipoxins and related compounds. PMID:3107549

  16. Phospholipase A2 stimulated release of lipoxin B4 formation from endogenous sources of arachidonic acid in porcine leukocytes.

    PubMed

    Wong, P Y

    1988-01-01

    Incubation of an isoenzyme of phospholipase A2 (PLA2, isolated from snake venom) with porcine leukocytes resulted in the formation of several trihydroxytetraene- containing compounds which were derived from endogenous sources of arachidonic acid. The formation of these endogenous compounds was dose-dependent with an EC50 of approximately 1.25 x 10(-8) M. At this concentration of the isoenzyme and time (10 min) of explosure the cells remained viable as determined by the exclusion of trypan blue. The trihydroxytetraene compounds were purified by RP-HPLC and their identities were analyzed by U.V. spectrometry, GC/MS and by comparison with synthetic materials. The biologically derived compounds proved to be lipoxin B4 (5S, 14R, 15S-trihydroxy-6,10,12-trans-8-cis-eicosatetraenoic acid) and its two structural isomers (8-trans-LXB4 and 14S-8-trans-LXB4). Results of the present study indicate that porcine leukocytes can generate lipoxin B4 and its isomers from endogenous sources of arachidonic acid. Moreover, they suggest that certain PLA2 isoenzymes may stimulate the formation of lipoxins and related compounds. PMID:3138901

  17. Auditory brain-stem evoked potentials in cat after kainic acid induced neuronal loss. II. Cochlear nucleus.

    PubMed

    Zaaroor, M; Starr, A

    1991-01-01

    Auditory brain-stem potentials (ABRs) were studied in cats for up to 6 weeks after kainic acid had been injected unilaterally into the cochlear nucleus (CN) producing extensive neuronal destruction. The ABR components were labeled by the polarity at the vertex (P, for positive) and their order of appearance (the arabic numerals 1, 2, etc.). Component P1 can be further subdivided into 2 subcomponents, P1a and P1b. The assumed correspondence between the ABR components in cat and man is indicated by providing human Roman numeral designations in parentheses following the feline notation, e.g., P2 (III). To stimulation of the ear ipsilateral to the injection, the ABR changes consisted of a loss of components P2 (III) and P3 (IV), and an attenuation and prolongation of latency of components P4 (V) and P5 (VI). The sustained potential shift from which the components arose was not affected. Wave P1a (I) was also slightly but significantly attenuated compatible with changes of excitability of nerve VIII in the cochlea secondary to cochlear nucleus destruction. Unexpectedly, to stimulation of the ear contralateral to the injection side, waves P2 (III), P3 (IV), and P4 (V) were also attenuated and delayed in latency but to a lesser degree than to stimulation of the ear ipsilateral to the injection. Changes in binaural interaction of the ABR following cochlear nucleus lesions were similar to those produced in normal animals by introducing a temporal delay of the input to one ear. The results of the present set of studies using kainic acid to induce neuronal loss in auditory pathway when combined with prior lesion and recording experiments suggest that each of the components of the ABR requires the integrity of an anatomically diffuse system comprising a set of neurons, their axons, and the neurons on which they terminate. Disruption of any portion of the system will alter the amplitude and/or the latency of that component. PMID:1716569

  18. A symphony of inner ear developmental control genes

    PubMed Central

    2010-01-01

    The inner ear is one of the most complex and detailed organs in the vertebrate body and provides us with the priceless ability to hear and perceive linear and angular acceleration (hence maintain balance). The development and morphogenesis of the inner ear from an ectodermal thickening into distinct auditory and vestibular components depends upon precise temporally and spatially coordinated gene expression patterns and well orchestrated signaling cascades within the otic vesicle and upon cellular movements and interactions with surrounding tissues. Gene loss of function analysis in mice has identified homeobox genes along with other transcription and secreted factors as crucial regulators of inner ear morphogenesis and development. While otic induction seems dependent upon fibroblast growth factors, morphogenesis of the otic vesicle into the distinct vestibular and auditory components appears to be clearly dependent upon the activities of a number of homeobox transcription factors. The Pax2 paired-homeobox gene is crucial for the specification of the ventral otic vesicle derived auditory structures and the Dlx5 and Dlx6 homeobox genes play a major role in specification of the dorsally derived vestibular structures. Some Micro RNAs have also been recently identified which play a crucial role in the inner ear formation. PMID:20637105

  19. Characterization of bunny-ear antennas for wireless basestation applications

    Microsoft Academic Search

    Marc C. Greenberg; Kathleen L. Virga

    1998-01-01

    The bunny-ear antenna (BEA) which has use for wireless basestation applications, mobile satellite communications, and radar imaging is characterized in detail. Whether the BEA is used as an isolated antenna or in an array, it needs to be well understood. A design methodology for the BEA and examples are presented. To discuss the effects from removing metalization near the feed,

  20. A symphony of inner ear developmental control genes.

    PubMed

    Chatterjee, Sumantra; Kraus, Petra; Lufkin, Thomas

    2010-01-01

    The inner ear is one of the most complex and detailed organs in the vertebrate body and provides us with the priceless ability to hear and perceive linear and angular acceleration (hence maintain balance). The development and morphogenesis of the inner ear from an ectodermal thickening into distinct auditory and vestibular components depends upon precise temporally and spatially coordinated gene expression patterns and well orchestrated signaling cascades within the otic vesicle and upon cellular movements and interactions with surrounding tissues. Gene loss of function analysis in mice has identified homeobox genes along with other transcription and secreted factors as crucial regulators of inner ear morphogenesis and development. While otic induction seems dependent upon fibroblast growth factors, morphogenesis of the otic vesicle into the distinct vestibular and auditory components appears to be clearly dependent upon the activities of a number of homeobox transcription factors. The Pax2 paired-homeobox gene is crucial for the specification of the ventral otic vesicle derived auditory structures and the Dlx5 and Dlx6 homeobox genes play a major role in specification of the dorsally derived vestibular structures. Some Micro RNAs have also been recently identified which play a crucial role in the inner ear formation. PMID:20637105

  1. EARS: Toward Fast Analysis of 3D Human

    E-print Network

    Anthropometric Rating System (EARS), an integrated collection of tunable semi-automatic procedures to compute during the upcoming large scan anthropometric survey. Keywords: 3D Human Body Scan, Mesh Segmentation in Anthropometric research and studies. 3D scans fully preserve the body shape measurements, and are the data

  2. Research Project on Ear Infections Dramatizes Challenge of Conflicts.

    ERIC Educational Resources Information Center

    Cordes, Colleen

    1993-01-01

    An unusual conflict-of-interest case involving the federal government, a university researcher on ear infections, and the pharmaceutical industry has renewed the debate over what constitutes unacceptable conflict of interest, federal review of medical treatment, government protection against research bias, and disclosure of research project…

  3. Auditory Responses in Normal-Hearing, Noise-Exposed Ears

    E-print Network

    Stamper, Greta

    2013-12-31

    and a click stimulus. DPOAEs were assessed at 1, 2 and 4 kHz. Significantly smaller amplitudes were seen in wave I of the ABR in response to high-level (e.g., 70 to 90 dB nHL) click and 4 kHz tone bursts in ears with greater noise-exposure backgrounds...

  4. Acoustic Reflectometry versus Tympanometry in Pediatric Middle Ear Screenings.

    ERIC Educational Resources Information Center

    Holmes, Alice E.; And Others

    1989-01-01

    Use of acoustic reflectometry was compared with tympanometry in middle ear screenings for 357 children, aged 5 months to 19 years. Results were analyzed according to sex, age, and sensorineural hearing status. Intratest reliability was highly significant and positive predictive accuracy and specificity rates were excellent, but sensitivity rates…

  5. 3D Ear Print Authentication using 3D Radon Transform

    Microsoft Academic Search

    W. A. Mahmoud; M. R. Shaker

    2006-01-01

    This paper introduces a proposed method authentication based upon 3D Radon transform. It considers the three dimensional ear of human as a personal identification number. Next, it produces the required features using the 3D Radon transform. This transform is adapted from its 2D form to adequate this application. The neural network was used in the identification phase, the evaluation test

  6. Atlas of the developing inner ear in zebrafish.

    PubMed

    Bever, Michele Miller; Fekete, Donna M

    2002-04-01

    This report provides a description of the normal developing inner ear of the zebrafish, Danio rerio, with special focus on the pars inferior. Zebrafish specimens, ranging in age from 3 to 30 days postfertilization (dpf), were processed for standard histologic sections or with a paint-fill method to show three-dimensional morphogenesis of the membranous labyrinth. Adult zebrafish (age 2 years) were also processed for inner ear paint-fills. Although development of the semicircular canals occurs rapidly (by 3 dpf), the pars inferior develops more gradually during days 5-20 postfertilization. A rudimentary endolymphatic duct emerges by 8 dpf. Differentiated hair cells of the lagenar macula are evident by 15 dpf, in a chamber located lateral and posterior to the saccule. By 20 dpf, the saccule itself is separated from the utricle, but remains connected by means of the utriculosaccular foramen. The maculae neglectae, each with differentiated hair cells, lie on the floor of the utricle near this foramen. A medial connection between the sacculi of right and left ears, the transverse canal, is also complete by 20 dpf. A ridge of mesenchyme, previously undescribed, bisects the saccule in zebrafish fry at 20-30 dpf. The images in the paint-fill atlas should provide a baseline for future studies of mutant zebrafish ears. PMID:11921341

  7. Behaviour and cognitive outcomes from middle ear disease

    PubMed Central

    Bennett, K.; Haggard, M.

    1999-01-01

    OBJECTIVES—To resolve controversies over associations between a history of middle ear disease and psychosocial or cognitive/educational outcomes?DESIGN—Multipurpose longitudinal birth cohort study. Original cohort comprised all UK births between 5 and 11 April 1970; data were available for approximately 12 000 children at 5 years old and 9000 children at 10 years old.?METHODS—For 5 year old children, parent reported data were available on health, social, and behavioural factors, including data on two validated markers of middle ear disease. Cognitive tests were administered at 5 and 10 years of age, and behavioural problems rated at 10 years by the child's teacher.?RESULTS—After adjustment for social background and maternal malaise, the developmental sequelae of middle ear disease remained significant even at 10 years. The largest effects were observed in behaviour problems and language test data at age 5, but effect sizes were modest overall.?IMPLICATIONS—These results provide an epidemiological basis for policies that aim to minimise the sequelae of middle ear disease by awareness in parents and preschool teachers, early referral, and intervention for more serious or persistent cases.?? PMID:10325755

  8. MOUSE-EAR OF PECAN: II. INFLUENCE OF NUTRIENT APPLICATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mouse-ear(ME) is a severe growth disorder affecting pecan [Carya illinoinensis (Wangenh.) K. Koch] trees in orchards within the Gulf Coast Coastal Plain of the southeastern U.S. Slight to moderate ME was corrected by foliar sprays of either Cu, Mn, or GA3 shortly after budbreak, but sprays were ine...

  9. MOUSE-EAR OF PECAN: I. SYMPTOMOLOGY AND OCCURRENCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mouse-ear is a potentially severe anomalous growth disorder affecting young pecan [Carya illinoinensis (Wangenh.) K. Koch] trees in portions of the Gulf Coast Coastal Plain of the southeastern U.S. A survey of its incidence and severity found it to be commonly exhibited by replants on second-genera...

  10. Mechanics of a 'simple' ear: tympanal vibrations in noctuid moths.

    PubMed

    Windmill, J F C; Fullard, J H; Robert, D

    2007-08-01

    Anatomically, the ears of moths are considered to be among the simplest ears found in animals. Microscanning laser vibrometry was used to examine the surface vibrations of the entire tympanal region of the ears of the noctuid moths Agrotis exclamationis, Noctua pronuba, Xestia c-nigrum and Xestia triangulum. During stimulation with ultrasound at intensities known to activate receptor neurones, the tympanum vibrates with maximum deflection amplitudes at the location where the receptor cells attach. In the reportedly heterogeneous tympana of noctuid moths, this attachment site is an opaque zone that is surrounded by a transparent, thinner cuticular region. In response to sound pressure, this region moves relatively little compared with the opaque zone. Thus, the deflections of the moth tympanic membrane are not those of a simple circular drum. The acoustic sensitivity of the ear of N. pronuba, as measured on the attachment site, is 100+/-14 nm Pa(-1) (N=10), corresponding to tympanal motion of a mere 200 pm at sound pressure levels near the neural threshold. PMID:17644678

  11. An outbreak of erysipelas in eared grebes (Podiceps nigricollis)

    USGS Publications Warehouse

    Jensen, W.I.; Cotter, S.E.

    1976-01-01

    An outbreak of erysipelas killed an estimated 5,000 aquatic birds on Great Salt Lake (Utah) in late November, 1975. Although several thousand ducks and gulls were using the lake, at least 99 percent of the victims were eared grebes. A hypothetical explanation for the selective mortality is offered.

  12. Early Middle Ear Effusion and Language at Age Seven

    ERIC Educational Resources Information Center

    Johnson, Dale L.; McCormick, David P.; Baldwin, Constance D.

    2008-01-01

    This study examined the relation of middle ear effusion (MEE) in the first 3 years of life to language outcomes at age seven. It was hypothesized, on the basis of a literature review, that (1) a low, but positive relation between early MEE and language measures in general will be observed at age seven, and (2) major effects will be demonstrated…

  13. MicroRNAs in sensorineural diseases of the ear

    PubMed Central

    Ushakov, Kathy; Rudnicki, Anya; Avraham, Karen B.

    2013-01-01

    Non-coding microRNAs (miRNAs) have a fundamental role in gene regulation and expression in almost every multicellular organism. Only discovered in the last decade, miRNAs are already known to play a leading role in many aspects of disease. In the vertebrate inner ear, miRNAs are essential for controlling development and survival of hair cells. Moreover, dysregulation of miRNAs has been implicated in sensorineural hearing impairment, as well as in other ear diseases such as cholesteatomas, vestibular schwannomas, and otitis media. Due to the inaccessibility of the ear in humans, animal models have provided the optimal tools to study miRNA expression and function, in particular mice and zebrafish. A major focus of current research has been to discover the targets of the miRNAs expressed in the inner ear, in order to determine the regulatory pathways of the auditory and vestibular systems. The potential for miRNAs manipulation in development of therapeutic tools for hearing impairment is as yet unexplored, paving the way for future work in the field. PMID:24391537

  14. A refractory case of erythromelalgia involving the ears

    Microsoft Academic Search

    Claudia C. Ramirez; Robert S. Kirsner

    2004-01-01

    Erythromelalgia is a rare syndrome that is characterized by episodic attacks of burning pain, erythema, and increased temperature usually affecting the extremities, which is aggravated by warmth or exercise. We describe a patient with a 3-year history of refractory burning pain and red ears. A review of clinical features, disease classification, associated diseases, and treatment of this disease is presented.

  15. Analysis of chick (Gallus gallus) middle ear columella formation

    Microsoft Academic Search

    Jamie L Wood; Ami J Hughes; Kathryn J Mercer; Susan C Chapman

    2010-01-01

    BACKGROUND: The chick middle ear bone, the columella, provides an accessible model in which to study the tissue and molecular interactions necessary for induction and patterning of the columella, as well as associated multiple aspects of endochondral ossification. These include mesenchymal condensation, chondrogenesis, ossification of the medial footplate and shaft, and joint formation between the persistent cartilage of the extracolumella

  16. ACOUSTIC STIMULATION OF THE EAR OF THE GOLDFISH (CARASSIUS AURATUS)

    Microsoft Academic Search

    RICHARD R. FAY; ARTHUR N. POPPER

    1974-01-01

    SUMMARY Microphonic potentials were recorded from the ears of the goldfish during acoustic stimulation in a situation where sound pressure and particle dis- placement could be varied. Microphonic potentials from fishes with the swim bladder intact were proportional to sound pressure. After removal of the swim bladder, sound pressure sensitivity declined by 20-35 dB and the response was generated in

  17. Maize resistance to gibberella ear rot: symptoms, deoxynivalenol, and yield

    Microsoft Academic Search

    B. Vigier; L. M. Reid; L. M. Dwyer; D. W. Stewart; R. C. Sinha; J. T. Arnason; G. Butler

    2001-01-01

    To investigate the effect of different environments on maize resistance to gibberella ear rot, disease symptoms, deoxynivalenol (DON) concentration, and grain yield were measured in three maize (Zea mays L.) inbred lines and five hybrids, from 1994 to1996, at six locations in eastern Canada. At each location, all genotypes were inoculated with a three-isolate macroconidial mix of Fusarium graminearum Schwabe

  18. Evaluating commercial maize hybrids for resistance to gibberella ear rot

    Microsoft Academic Search

    A. W. Schaafsma; R. W. Nicol; L. M. Reid

    1997-01-01

    An integral component of breeding maize for resistance to Fusarium graminearum ear rot is the identification of resistant genotypes. Since natural infection is not consistent from year to year, maize researchers must use manual techniques to inoculate the plant material with fungal spores. Information is presented here on site resistance of commercial maize hybrids to F. graminearum over three years

  19. Relating middle-ear acoustic performance to body size in the cat family: measurements and models

    Microsoft Academic Search

    G. T. Huang; J. J. Rosowski; W. T. Peake

    2000-01-01

    Is the acoustic performance of the mammalian middle ear dependent on body size? We focus on the cat family, because of its\\u000a qualitatively uniform (and distinctive) middle-ear structure, large size range, and the extensive data available from domestic\\u000a cats which provide a framework for relating middle-ear acoustics to structure. We report measurements of acoustic admittance\\u000a in 17 live adult ears

  20. Olodaterol Attenuates Citric Acid-Induced Cough in Naïve and Ovalbumin-Sensitized and Challenged Guinea Pigs

    PubMed Central

    Wex, Eva; Bouyssou, Thierry

    2015-01-01

    Excessive coughing is a common feature of airway diseases. Different G-protein coupled receptors, including ?2-adrenergic receptors (?2-AR), have been implicated in the molecular mechanisms underlying the cough reflex. However, the potential antitussive property of ?2-AR agonists in patients with respiratory disease is a matter of ongoing debate. The aim of our study was to test the efficacy of the long-acting ?2-AR agonist olodaterol with regard to its antitussive property in a pre-clinical model of citric acid-induced cough in guinea pigs and to compare the results to different clinically relevant ?2-AR agonists. In our study ?2-AR agonists were intratracheally administered, as dry powder, into the lungs of naïve or ovalbumin-sensitized guinea pigs 15 minutes prior to induction of cough by exposure to citric acid. Cough events were counted over 15 minutes during the citric acid exposure. Olodaterol dose-dependently inhibited the number of cough events in naïve and even more potently and with a greater maximal efficacy in ovalbumin-sensitized guinea pigs (p < 0.01). Formoterol and salmeterol showed a trend towards reducing cough. On the contrary, indacaterol demonstrated pro-tussive properties as it significantly increased the number of coughs, both in naïve and ovalbumin-sensitized animals (p < 0.001). In conclusion, olodaterol, at doses eliciting bronchodilation, showed antitussive properties in a model of citric acid-induced cough in naïve and ovalbumin-sensitized guinea pigs. This is in agreement with pre-clinical and clinical studies showing antitussive efficacy of ?2-AR agonists. Indacaterol increased the number of coughs in this model, which concurs with clinical data where a transient cough has been observed after indacaterol inhalation. While the antitussive properties of ?2-AR agonists can be explained by their ability to lead to the cAMP-induced hyperpolarization of the neuron membrane thereby inhibiting sensory nerve activation and the cough reflex, the mechanism underlying the pro-tussive property of indacaterol is not known. PMID:25781609

  1. [Correlation between inner ear disorders and temporomandibular joint diseases].

    PubMed

    Kempf, H G; Roller, R; Mühlbradt, L

    1993-01-01

    Acute and chronic inner ear diseases involve many etiological factors, some as yet unknown. ENT-specific, orthopedic, hemorrheological, immunological and neurological disorders can affect the cochleovestibular system and induce hearing loss, vertigo and/ortinnitus. We performed a prospective study to analyze factors of the dentognathological system and of the temporomandibular joint that can influence acute and chronic inner ear dysfunctions. A total of 138 patients (49.3% female, 50.9% male) receiving clinical treatment for inner ear dysfunctions (12.3% chronic sensorineural hearing loss, 15.2% Ménière's disease, 52.2% sudden hearing loss, 13.8% isolated tinnitus, 6.5% recurrent hearing loss) underwent a prospective dental and gnathological examination. In particular, the patient's dental status and a functional investigation of the masticatory muscles and the temporomandibular joint were analyzed. In 20.3% patients the examination showed no pathology of the dentognathological system. In contrast, there were pathological findings in 110 patients (79.7%): in 43.5% a temporomandibular joint syndrome was diagnosed, in 29% parafunction of the occlusion, and in 35% a myopathy of the masticatory muscles. Additionally 32.6% patients showed dental disorders that required treatment; 11.65% had problems with dentures and 20.3% malpositioned wisdom teeth. In 16 patients the recommended dental treatment was followed up and improvement of otological symptoms was found in 56.6%. The present investigation shows that many patients with inner ear dysfunction suffer from dentognathological disorders. For a subgroup of patients there exists the possibility of improving otological symptoms by dental treatment. Therefore we recommend a dentognathological examination in patients with inner ear dysfunctions of unknown etiology. PMID:8449789

  2. Middle-ear function with tympanic-membrane perforations. II. A simple model

    E-print Network

    Allen, Jont

    Middle-ear function with tympanic-membrane perforations. II. A simple model Susan E. Vossa) Picker-Peabody Laboratory of Auditory Physiology and Department of Otolaryngology, Massachusetts Eye and Ear Infirmary and Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114; Speech

  3. Building and Testing a Statistical Shape Model of the Human Ear Canal

    E-print Network

    Building and Testing a Statistical Shape Model of the Human Ear Canal Rasmus Paulsen1 , Rasmus Snekkersten, Denmark {cni, slu}@oticon.dk, http://www.oticon.com/ Abstract. Today the design of custom in-the-ear of the variation of the shape of the ear canal. In this paper it is described how a dense surface point

  4. Middle Ear Cavity Morphology Is Consistent with an Aquatic Origin for Testudines

    E-print Network

    Middle Ear Cavity Morphology Is Consistent with an Aquatic Origin for Testudines Katie L. Willis1 environments, we examined middle ear morphology and scaling in most extant families, as well as some extinct of the middle ear cavity, with the tympanic disk located on the rostrolateral edge of the cavity. Sea Turtles

  5. Identification with a recombinant antibody of an inner-ear cytokeratin, a marker for

    E-print Network

    Hudspeth, A. James

    Identification with a recombinant antibody of an inner-ear cytokeratin, a marker for hair by A. James Hudspeth, February 4, 2000 Extensive biochemical characterization of cells in the inner ear has been hampered by a lack of tools with which to identify inner-ear proteins. By using a single

  6. Interactive Direct Volume Rendering of the Inner Ear for the Planning of Neurosurgery

    E-print Network

    Blanz, Volker

    Interactive Direct Volume Rendering of the Inner Ear for the Planning of Neurosurgery P. Hastreiter and inner ear is presented. The segmen- tation of the spiral CT­data and the reconstruction was performed considerably diffi- cult with the small and complex structures of the middle and the inner ear which requires

  7. Connecting the ear to the brain: Molecular mechanisms of auditory circuit assembly

    E-print Network

    Goodrich, Lisa V.

    Connecting the ear to the brain: Molecular mechanisms of auditory circuit assembly Jessica M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 3.2.1. Sox2 and the maintenance of precursors in the inner ear 2011 Keywords: Auditory system Inner ear Neural development Circuit assembly Spiral ganglion neuron A B

  8. Ontogenetic and Phylogenetic Transformations of the Ear Ossicles in Marsupial Mammals

    E-print Network

    Smith, Kathleen K.

    Ontogenetic and Phylogenetic Transformations of the Ear Ossicles in Marsupial Mammals Marcelo R. Sa a wide range of taxa and aims at addressing several issues con- cerning the evolution of the ear ossicles in marsupials. Three-dimensional reconstructions of the ear ossicles based on histological series were done

  9. In Vivo Analysis of Lrig Genes Reveals Redundant and Independent Functions in the Inner Ear

    E-print Network

    Goodrich, Lisa V.

    In Vivo Analysis of Lrig Genes Reveals Redundant and Independent Functions in the Inner Ear Tony compared the expression and function of the Lrigs in the inner ear, which offers a sensitive system in the inner ear throughout development, with Lrig1 and Lrig3 restricted to subsets of cells and Lrig2

  10. ARTICLE doi:10.1038/nature09921 Transitional mammalian middle ear from

    E-print Network

    Sullivan, Jack

    ARTICLE doi:10.1038/nature09921 Transitional mammalian middle ear from a new Cretaceous Jehol the dentary and the detached ossicles during mammalian evolution. This transitional mammalian middle ear narrows the morphological gap between the mandibular middle ear in basal mammaliaforms and the definitive

  11. Connecting the ear to the brain: Molecular mechanisms of auditory circuit assembly

    E-print Network

    Goodrich, Lisa V.

    Connecting the ear to the brain: Molecular mechanisms of auditory circuit assembly Jessica M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 000 3.2.1. Sox2 and the maintenance of precursors in the inner ear 9 December 2010 Accepted 3 January 2011 Keywords: Auditory system Inner ear Neural development

  12. Measurements of Forward and Reverse Acoustics of the Human Middle Ear: Implications for Otoacoustic Emissions

    E-print Network

    Allen, Jont

    Measurements of Forward and Reverse Acoustics of the Human Middle Ear: Implications for Otoacoustic and California Ear Institute at Stanford, 801 Welch Road, Palo Alto, CA 94304 Email: puria@stanford.edu Running/Abbreviated Title: Forward and reverse middle-ear acoustics Corresponding Author: Sunil Puria, PhD Dept

  13. Session 1pPPa --1 --Evaluation of a physiological ear model for the simulation of

    E-print Network

    Session 1pPPa -- 1 -- Evaluation of a physiological ear model for the simulation of nonlinear] it was shown that the ear model is able to rebuild the level­dependency of spectral and temporal masking by the physiological ear model. Since the model represents a unified approach comprising the most important masking

  14. Multi-Modal Biometrics Involving the Human Ear Christopher Middendorff, Kevin W. Bowyer, Ping Yan

    E-print Network

    Zhu, Zhigang

    Multi-Modal Biometrics Involving the Human Ear Christopher Middendorff, Kevin W. Bowyer, Ping Yan and robustness against change over time, the ear has become an increasingly pop- ular biometric feature. It has of combi- nation and the recognition rates of each. 1. Introduction Ears have gained attention

  15. Analysis of Gentamicin Kinetics in Fluids of the Inner Ear with Round Window Administration

    E-print Network

    Salt, Alec N.

    Analysis of Gentamicin Kinetics in Fluids of the Inner Ear with Round Window Administration *Stefan for quantifying drug distri- bution in the inner ear with local applications can be established. Background: As methods of local drug delivery to the inner ear gain wider clinical acceptance it becomes important to es

  16. Does the infrasound from wind turbines affect the inner ear? Alec N. Salt1

    E-print Network

    Salt, Alec N.

    Does the infrasound from wind turbines affect the inner ear? Alec N. Salt1 1 Washington University that the response of the inner ear to infrasound is complex and needs to be understood in more detail before it can be concluded that the ear cannot be affected by wind turbine noise. This work was supported by research grant

  17. INTRODUCTION The mammalian inner ear consists of two sensory organs: the

    E-print Network

    Ryugo, David K.

    INTRODUCTION The mammalian inner ear consists of two sensory organs: the cochlea and vestibular of the inner ear is composed of saccule, utricle and semicircular canals, which together determine head-dating analyses have provided evidence that all inner ear hair cells are produced in a period spanning from

  18. Prediction of a Mysticete Audiogram via Finite Element Analysis of the Middle Ear

    E-print Network

    Prediction of a Mysticete Audiogram via Finite Element Analysis of the Middle Ear Andrew Tubelli published audiograms. Both the middle ear and the cochlea play an important role in shaping the audiogram of any mammal. The transfer function of the middle ear shapes the low-frequency portions of an audiogram

  19. Percutaneous inner-ear access via an image-guided industrial robot system

    E-print Network

    Webster III, Robert James

    Percutaneous inner-ear access via an image-guided industrial robot system S Baron1 , H Eilers1 , B-accuracy requirements and proximity to sensitive nerves and brain tissues, the adoption of robots in inner-ear surgery-guided industrial robot systems for accessing challenging inner-ear targets. Features of the systems include optical

  20. Measurements of human middle ear forward and reverse acoustics: Implications for otoacoustic emissions

    E-print Network

    Allen, Jont

    Measurements of human middle ear forward and reverse acoustics: Implications for otoacoustic and California Ear Institute at Stanford, 801 Welch Road, Palo Alto, California 94304 Received 11 July 2002; revised 1 February 2003; accepted 4 February 2003 Middle and inner ears from human cadaver temporal bones

  1. STRUCTURE AND FUNCTIONS OF THE EAR OF THE By G. H. Parker, Ph. D.

    E-print Network

    STRUCTURE AND FUNCTIONS OF THE EAR OF THE SQUETEAGUE By G. H. Parker, Ph. D. Professor of. S. A., September 22 to 26, 1908 I2II #12;Blank page retained for pagination #12;ANATOMY OF THE EAR. STRUCTURE AND FUNCTIONS OF THE EAR OF THE SQUETEAGUE. ..,c By G. H. PARKER, Ph. D., Professor of Zoology

  2. Short Communication Functional ear (a)symmetry in brainstem neural activity relevant to encoding

    E-print Network

    Dasgupta, Dipankar

    Short Communication Functional ear (a)symmetry in brainstem neural activity relevant to encoding (FFR) Functional ear asymmetry Experience-dependent plasticity Subcortical a b s t r a c t Pitch areas. This experiment investigates whether ear asymmetries vary in brainstem representation of pitch

  3. Steps for Using the EAR Part 732-page 1 Export Administration Regulations

    E-print Network

    Bernstein, Daniel

    Steps for Using the EAR Part 732-page 1 Export Administration Regulations §732.1 STEPS OVERVIEW (a)(1) Introduction In this part, references to the EAR are references to 15 CFR chapter VII, subchapter C. This part is intended to help you determine your obligations under the EAR by listing logical

  4. Laminin and Fibronectin Modulate Inner Ear Spiral Ganglion Neurite Outgrowth in an In Vitro Alternate

    E-print Network

    Bhatia, Sangeeta

    Laminin and Fibronectin Modulate Inner Ear Spiral Ganglion Neurite Outgrowth in an In Vitro) and fibronectin (FN) presented in stripe micro-patterns can provide guidance cues to neonatal (P5) inner ear model for neurite guidance in the developing inner ear in vivo. LN, in the SG and osseus spiral lamina

  5. MicroRNAs and epigenetic regulation in the mammalian inner ear: implications for deafness

    E-print Network

    Avraham, Karen

    MicroRNAs and epigenetic regulation in the mammalian inner ear: implications for deafness Lilach M common sensory disorder in humans and derives, in most cases, from inner-ear defects or degeneration is expressed specifically in the inner-ear hair cells, were linked with progressive hearing loss in humans

  6. The two ear theorem on matching-covered graphs Zoltan Szigeti

    E-print Network

    Szigeti, Zoltán

    The two ear theorem on matching-covered graphs Zolt´an Szigeti Abstract We give a simple and short proof for the two ear theorem on matching- covered graphs which is a well-known result of Lov) has a perfect matching. A sequence of subgraphs of G, (G0, G1, ..., Gm) is a graded ear

  7. Effect of Negative Middle-Ear Pressure on Transient-Evoked Otoacoustic Emissions

    E-print Network

    Allen, Jont

    Effect of Negative Middle-Ear Pressure on Transient- Evoked Otoacoustic Emissions Lynne Marshall of negative middle-ear pressure (MEP) on both the stimulus and response of transient-evoked otoacoustic emissions (TEOAEs) and the effect of compensating for negative pressure in the middle ear by pneumatically

  8. Specification of absorbed-sound power in the ear canal: Application to suppression of stimulus frequency

    E-print Network

    Allen, Jont

    Specification of absorbed-sound power in the ear canal: Application to suppression of stimulus; accepted 12 November 2010) An insert ear-canal probe including sound source and microphone can deliver a calibrated sound power level to the ear. The aural power absorbed is proportional to the product of mean

  9. SHORT SCIENTIFIC COMMUNICATION Acoustic recordings in human ear canals to sounds

    E-print Network

    Oliver, Douglas L.

    SHORT SCIENTIFIC COMMUNICATION Acoustic recordings in human ear canals to sounds at different for different sound locations in an anechoic chamber. For humans, we embedded microphones in ear molds that were custom fitted to the subject's ear canal. For the ball, the microphones were flush with the surface at 90

  10. Reflectance in ME disorders 1 Running head: REFLECTANCE IN MIDDLE-EAR DISORDERS

    E-print Network

    Allen, Jont

    Reflectance in ME disorders 1 Running head: REFLECTANCE IN MIDDLE-EAR DISORDERS Wideband energy reflectance measurements in adults with middle-ear disorders M. Patrick Feeney University of Washington pressure in adults with a variety of middle-ear disorders. The ER results from nine participants

  11. RNA Isolation from Xenopus Inner Ear Sensory Endorgans for Transcriptional Profiling and Molecular Cloning

    E-print Network

    Chapter 1 RNA Isolation from Xenopus Inner Ear Sensory Endorgans for Transcriptional Profiling systems mandate the ability to isolate intact RNA from inner ear tissue. Methods presented here facilitate preparation of high quality inner ear RNA from larval and post-metamorphic Xenopus spec- imens that can

  12. Mouse Models for Deafness: Lessons for the Human Inner Ear and Hearing Loss

    E-print Network

    Avraham, Karen

    Mouse Models for Deafness: Lessons for the Human Inner Ear and Hearing Loss Karen B. Avraham high-resolution com- puted tomography (CT) scanning or invasive sur- gery, most studies on the ear interventions can be developed that can treat the diseased inner ear before permanent damage has occurred

  13. Audiometric Predictions Using Stimulus-Frequency Otoacoustic Emissions and Middle Ear

    E-print Network

    Allen, Jont

    Audiometric Predictions Using Stimulus-Frequency Otoacoustic Emissions and Middle Ear Measurements or moderate-severe, and correlate with pure-tone thresholds in a population of adults with normal middle ear function. Other goals are to determine if middle ear function as assessed by wideband acoustic transfer

  14. Ear-Canal Reflectance, Umbo Velocity, and Tympanometry in Normal-Hearing Adults

    E-print Network

    Allen, Jont

    Ear-Canal Reflectance, Umbo Velocity, and Tympanometry in Normal-Hearing Adults John J. Rosowski,1. Halpin,4 and Saumil N. Merchant1,2,3 Objective: This study compares measurements of ear-canal reflectance (ECR) to other objective measurements of middle ear function including audiometry, umbo velocity (VU

  15. Biometric Recognition Using 3D Ear Shape Ping Yan and Kevin W. Bowyer, Fellow, IEEE

    E-print Network

    Bowyer, Kevin W.

    Biometric Recognition Using 3D Ear Shape Ping Yan and Kevin W. Bowyer, Fellow, IEEE Abstract--Previous works have shown that the ear is a promising candidate for biometric identification. However, in prior work, the preprocessing of ear images has had manual steps and algorithms have not necessarily handled

  16. MicroRNAs are essential for development and function of inner ear hair cells in vertebrates

    E-print Network

    Hornstein, Eran

    MicroRNAs are essential for development and function of inner ear hair cells in vertebrates Lilach, the 2 inner ear compart- ments. A conditional knock-out mouse for Dicer1 demonstrated that miRNAs are crucial for postnatal survival of functional hair cells of the inner ear. We identified miRNAs that have

  17. EARs in the Wild: Large-Scale Analysis of Execution After Redirect Vulnerabilities

    E-print Network

    Kruegel, Christopher

    EARs in the Wild: Large-Scale Analysis of Execution After Redirect Vulnerabilities Pierre Payet a research paper that incorrectly modeled the redirect seman- tics, causing their static analysis to miss EAR vulnerabilities. To understand the breadth and scope of EARs in the real world, we performed a large

  18. Brain power - borrowing from biology makes for low power computing [bionic ear

    Microsoft Academic Search

    R. Sarpeshkar

    2006-01-01

    This paper describes the recent advances in the field of neuromorphic engineering, more generally, biologically inspired electronics. This paper focuses on the work being done to develop bionic ears. A key area of interest is understanding the scheme that allows low-power analog processing in the ear followed by digitization. Researchers at MIT have developed a bionic ear processor that does

  19. Renal ultrasonography not required in babies with isolated minor ear anomalies

    Microsoft Academic Search

    S A Deshpande; H Watson

    2006-01-01

    Aim: To determine whether infants with isolated minor anomalies of the external ear are at increased risk of renal malformations.Methods: Consecutive infants with isolated minor anomalies of the external ear (preauricular skin tags, preauricular sinuses, ear pits, and misshapen pinnae) were offered renal ultrasonography by experienced sonographers over a 41 month period. The prevalence of renal anomalies in such infants

  20. Noninvasive in vivo optical detection of biofilm in the human middle ear

    E-print Network

    Boppart, Stephen

    Noninvasive in vivo optical detection of biofilm in the human middle ear Cac T. Nguyena and the presence of a bacterial biofilm within the middle ear. Biofilms are typically very thin and cannot to noninvasively assess the middle ear to detect and quantify biofilm microstructure. This study involves adults