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1

Failure of superoxide dismutase to alter equine arachidonic acid-induced platelet aggregation, in vitro or ex vivo.  

PubMed

Superoxide dismutase (SOD), a free radical scavenger with anti-inflammatory activity, was administered IM to horses. Ex vivo platelet aggregation in response to arachidonic acid was monitored to determine whether exogenous SOD altered equine platelet prostaglandin metabolism. Preparations of platelet-rich plasma obtained before SOD administration were incubated with different concentrations of SOD and were aggregated with arachidonic acid. Superoxide dismutase did not exert a demonstrable effect, either ex vivo or in vitro. Aspirin abolished arachidonic acid-induced platelet aggregation in vitro. This indicates that SOD (in the resting state) does not exert an effect on platelet-derived free radicals that could alter the arachidonic acid pathway of equine platelets, that equine platelets do not release free radicals, or that equine platelets are insensitive to the products formed from free radicals by SOD. PMID:3923876

Clemmons, R M; Lee, M R; Bliss, E L; Asbury, A C; Cook, D; Brown, V

1985-05-01

2

Prostaglandin and Leukotriene Synthesis in Mouse Ears Inflamed by Arachidonic Acid  

Microsoft Academic Search

Topical application of arachidonic acid on mouse ears induces the synthesis of prostaglandin E2 and leukotrienes C4 and D4. The increased tissue levels of these products are quantitated by radioimmunoassay. The identity of the leukotrienes was confirmed by immunoreactivity of reverse-phase high-performance liquid chromatography fractions corresponding to authentic standards. Synthesis of the arachidonic acid metabolites precedes or is coincident with

Evan E. Opas; Robert J. Bonney; John L. Humes

1985-01-01

3

Ligand-independent activation of EphA2 by arachidonic acid induces metastasis-like behaviour in prostate cancer cells  

PubMed Central

Background: High intake of omega-6 polyunsaturated fatty acids (PUFA) has been associated with clinical progression in prostate cancer (CaP). This study investigates the signalling mechanism by which the omega-6 PUFA arachidonic acid (AA) induces prostatic cellular migration to bone marrow stroma. Methods: Western blot analysis of the PC-3, PC3-GFP, DU 145 and LNCaP cells or their lipid raft (LR) components post AA stimulation was conducted in association with assays for adhesion and invasion through the bone marrow endothelial monolayers. Results: Arachidonic acid increased transendothelial migration of PC3-GFP cells (adhesion 37%±0.08, P=0.0124; transmigration 270%±0.145, P=0.0008). Akt, Src and focal adhesion kinase (FAK) pathways were induced by AA and integrally involved in transendothelial migration. LR were critical in AA uptake and induced Akt activity. Ephrin receptor A2 (EphA2), localised in LR, is expressed in DU 145 and PC-3 cells. Arachidonic acid induced a rapid increase of EphA2 Akt-dependent/ligand-independent activation, while knockdown of the EphrinA1 ligand decreased AA induced transendothelial migration, with an associated decrease in Src and FAK activity. Arachidonic acid activated Akt in EphA2? LNCaP cells but failed to induce BMEC transendothelial invasion. Conclusion: Arachidonic acid induced stimulation of EphA2 in vitro is associated fundamentally with CaP epithelial migration across the endothelial barrier. PMID:23037715

Tawadros, T; Brown, M D; Hart, C A; Clarke, N W

2012-01-01

4

Arachidonic acid, an omega-6 fatty acid, induces cytoplasmic phospholipase A2 in prostate carcinoma cells.  

PubMed

For the past 60 years, dietary intake of essential fatty acids has increased. Moreover, the omega-6 fatty acids have recently been found to play an important role in regulation of gene expression. Proliferation of human prostate cells was significantly increased 48 h after arachidonic acid (AA) addition. We have analyzed initial uptake using nile red fluorescence and we found that the albumin conjugated AA is endocytosed into the cells followed by the induction of RNA within minutes, protein and PGE2 synthesis within hours. Here we describe that AA induces expression of cytosolic phospholipase A2 (cPLA2) in a dose-dependent manner and that this upregulation is dependent upon downstream synthesis of PGE2. The upregulation of cox-2 and cPLA2 was inhibited by flurbiprofen, a cyclooxygenase (COX) inhibitor, making this a second feed-forward enzyme in the eicosanoid pathway. Cox-2 specific inhibitors are known to inhibit colon and prostate cancer growth in humans; however, recent findings show that some of these have cardiovascular complications. Since cPLA2 is upstream in the eicosanoid pathway, it may be a good alternative for a pharmaceutical target for the treatment of cancer. PMID:15878913

Hughes-Fulford, Millie; Tjandrawinata, Raymond R; Li, Chai-Fei; Sayyah, Sina

2005-09-01

5

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

PubMed Central

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

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

6

Effects of PAF-antagonists in mouse ear oedema induced by several inflammatory agents.  

PubMed Central

1. Several platelet activating factor (PAF)-antagonists of different chemical structures were tested in the arachidonic acid-, tetradecanoylphorbol acetate-, dithranol-, and benzoic acid-induced mouse ear oedema models. 2. Topical application of UR-10324, UR-11353, CV-6209 and WEB-2086 markedly inhibited ear oedema induced by the four irritants tested, mimicking the profile obtained with dexamethasone. YM-461 was highly effective only in the dithranol-induced ear oedema, while BN-52021 failed to inhibit ear oedema in all models tested. 3. Leukocyte recruitment into the inflamed ears was prevented by PAF-antagonists, as measured by myeloperoxidase activity in the supernatants of ear homogenates. 4. A relationship between PAF-antagonist and anti-inflammatory activities was found in some cases, but other mechanisms cannot be excluded to explain the topical anti-inflammatory effect of these compounds. 5. Our results suggest that topical formulations containing PAF-antagonists could be useful in the treatment of some inflammatory skin diseases and provide evidence on the involvement of PAF in these inflammatory processes. PMID:1810607

Merlos, M.; Gomez, L. A.; Giral, M.; Vericat, M. L.; Garcia-Rafanell, J.; Forn, J.

1991-01-01

7

Ear Problems  

MedlinePLUS

... outer ear and the surrounding skin? Yes Your ear canal, outer ear and the skin around your ear ... thick pus-filled or bloody drainage from the ear canal that started after a sharp, sudden pain? Yes ...

8

Lipid-derived signals that discriminate wound- and pathogen-responsive isoprenoid pathways in plants: methyl jasmonate and the fungal elicitor arachidonic acid induce different 3-hydroxy-3-methylglutaryl-coenzyme A reductase genes and antimicrobial isoprenoids in Solanum tuberosum L.  

PubMed Central

Induction of 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGR; EC 1.1.1.34) is essential for the synthesis of steroid derivatives and sesquiterpenoid phytoalexins in solanaceous plants following mechanical injury or pathogen infection. Gene-specific probes corresponding to different HMGR genes (hmg1 and hmg2) were used to study HMGR expression in potato tissue following treatment with methyl jasmonate, a lipoxygenase product of linolenic acid, or arachidonic acid, an elicitor present in the lipids of the potato late blight fungus Phytophthora infestans. Treatment of potato discs (2.2 cm in diameter) with low concentrations (0.45-45 nmol per disc surface) of methyl jasmonate nearly doubled the wound-induced accumulation of hmg1 transcripts and steroid-glycoalkaloid (SGA) accumulation, reduced the abundance of hmg2 transcripts, and did not induce phytoalexins. High concentrations of methyl jasmonate (2-4.5 mol per disc surface) suppressed hmg1 mRNA and SGA accumulation but did not affect hmg2 mRNA abundance or induce phytoalexins. In contrast, arachidonate treatment strongly suppressed hmg1 and strongly induced hmg2 mRNA in a concentration-dependent manner. There was a corresponding suppression of SGA accumulation and an induction of sesquiterpene phytoalexin accumulation by this elicitor. Lipoxygenase inhibitors reduced the wound-induced accumulation of hmg1 transcripts and suppressed SGA levels, effects that were overcome by exogenous methyl jasmonate (45 nmol per disc surface). The results (i) suggest that methyl jasmonate can function as a signal for hmg1 expression and SGA induction following wounding and (ii) indicate that the arachidonate- and jasmonate-response pathways are distinct in relation to HMGR gene expression and isoprenoid product accumulation. The results also are consistent with placement of the HMGR activities encoded by hmg1 and hmg2 within discrete steroid and sesquiterpenoid biosynthetic channels. Images PMID:11607466

Choi, D; Bostock, R M; Avdiushko, S; Hildebrand, D F

1994-01-01

9

Ear examination  

MedlinePLUS

... or forward on the ear to straighten the ear canal. Then, the tip of the otoscope will be ... light beam shines through the otoscope into the ear canal. The health care provider will carefully move the ...

10

Swimmer's Ear  

MedlinePLUS

... skin that's protected by a thin coating of earwax . Most of the time, water can run in ... an Ear Infection? Perforated Eardrum Your Ears What's Earwax? How Do Pain Relievers Work? Taking Care of ...

11

Ear wax  

MedlinePLUS

... in the ear: Baby oil Commercial drops Glycerin Mineral oil Water Another method is to wash out the ... cloth or paper tissue wrapped around your finger. Mineral oil can be used to moisturize the ear and ...

12

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 ...

13

Super Ears.  

ERIC Educational Resources Information Center

Presents an activity in which students design, construct, and test "super ears" to investigate sound and hearing. Students work in groups of three and explore how the outer ear funnels sound waves to the inner ear and how human hearing compares to that of other animals. (NB)

Thompson, Stan

1995-01-01

14

Ear emergencies  

MedlinePLUS

... a clean cloth and keep it on ice. DRAINAGE FROM INSIDE THE EAR Cover the outside of ... DO NOT block any drainage coming from the ear. DO NOT try to clean or wash the inside of the ear canal. DO NOT put ...

15

Magnesium and arachidonic acid metabolism.  

PubMed

The arachidonic acid content of plasma lipoproteins is altered during dietary magnesium deficiency, although the tissue arachidonic acid content seems to be unchanged. The primary event triggering these changes is probably the loss of extracellular Mg2+, as it is not clear whether dietary magnesium deficiency produces loss of intracellular Mg2+. In the isolated rabbit heart, in vitro perfusion conditions which produce loss of intracellular Mg2+ also result in disturbances of arachidonic acid metabolism. The metabolism of exogenous arachidonic acid to prostaglandins is increased without changing the Km or Vmax of cyclo-oxygenase. The incorporation of arachidonic acid into tissue phospholipids is significantly reduced, although the incorporation of oleate, stearate, and linolenate is either increased or unchanged. These data indicate that the activity of the enzymes (CoA synthetases and acyl transferases) which mediate arachidonate incorporation is reduced during Mg2+ depletion. Since protein-kinase-C-mediated phosphorylation of both CoA synthetase and acyl transferase reduces their activity, and since protein kinase C has an Mg2+ binding site, it is possible to speculate that loss of intracellular Mg2+ may lead to the activation of protein kinase C, with the consequent reduction of arachidonic acid reacylation enzyme activity. PMID:8274364

Weis, M T; Saunders, C

1993-06-01

16

Ear Tumors  

MedlinePLUS

... infections may have an increased risk of developing squamous cell carcinoma. When these cancers first appear, they can be successfully treated by removing them surgically or by applying radiation therapy. More advanced cancers may require surgical removal of a larger area of the external ear. ... Back to Top Previous: Dermatitis of the Ear ...

17

Your Ears  

MedlinePLUS

... fluid in the semicircular canals stops moving, your brain gets the right message and you regain your balance. Three Cheers for the Ears! Your ears take care of you, so take care of them. Protect your hearing by wearing earplugs at loud music concerts and around noisy machinery, like in wood ...

18

Animal Ears  

NSDL National Science Digital Library

This activity (page 2 of the PDF) is a full inquiry investigation into animal behavior and communication. Groups of learners will fashion a headband with fake ears, similar in shape to those of the animal they are going to observe. Then, they record observations of the animalâs reactions when a learner, wearing the ears in different positions, brings it a snack. Learners develop categories of behavior to organize and evaluate the results. Safety Note: an adult handler must be present if working with a horse or even a large dog. Relates to linked video, DragonflyTV: Horse Ears.

Twin Cities Public Television, Inc.

2006-01-01

19

Ear Tubes  

MedlinePLUS

... more below. Please direct any interview requests or policy questions to our media and public ... nearly every child has experienced at least one episode. Most ear infections either resolve on their ...

20

How the Ear Works  

MedlinePLUS

... the part you can see) opens into the ear canal. The eardrum (tympanic membrane) separates the ear canal from the middle ear. The middle ear contains ... funnel through the ear opening, down the external ear canal, and strike your eardrum, causing it to vibrate. ...

21

Ear Training  

NSDL National Science Digital Library

Using these websites, you can practice your ear training skills. There are links for intervals, chords, and short melodic segments. First, you should go to this website to practice intervals. Intervals Begin with the first option (simple intervals up). After mastering this, move to simple intervals down. As you become more advanced, continue down the line of interval options. They will become more difficult as you ...

2009-09-15

22

Travel Inside the Ear  

MedlinePLUS Videos and Cool Tools

... for Educators Videos Travel Inside the Ear Video Travel Inside the Ear Video When sound waves reach ... are smaller than an orange seed. It then travels into the inner ear, which is filled with ...

23

Angiotensin II stimulates fibronectin protein synthesis via a G??/arachidonic acid-dependent pathway.  

PubMed

In rabbit proximal tubular cells, ANG II type 2-receptor (AT2)-induced arachidonic acid release is PLA2 coupled and dependent of G protein ?? (G??) subunits. Moreover, ANG II activates ERK1/2 and transactivates EGFR via a c-Src-dependent mechanism. Arachidonic acid has been shown to mimic this effect, at least in part, by an undetermined mechanism. In this study, we determined the effects of ANG II on fibronectin expression in cultured rabbit proximal tubule cells and elucidated the signaling pathways associated with such expression. We found that ANG II and transfection of G?? subunits directly increased fibronectin protein expression, and this increase was inhibited by overexpression of ?-adrenergic receptor kinase (?ARK)-ct or DN-Src. Moreover, ANG II-induced fibronectin protein expression was significantly abrogated by the AT2 receptor antagonist PD123319. In addition, inhibition of cystolic PLA2 diminished ANG II-induced fibronectin expression. Endogenous arachidonic acid mimicked ANG II-induced fibronectin expression. We also found that overexpression of G?? subunits induced c-Src, ERK1/2, and EGFR tyrosine phosphorylation, which can be inhibited by overexpression of ?ARK-ct or DN-Src. G?? also induced c-Src SH2 domain association with the EGFR. Supporting these findings, in rabbit proximal tubular epithelium, immunoblot analysis indicated that ?? expression was significant. Interestingly, arachidonic acid- and eicosatetraenoic acid-induced responses were preserved in the presence of ?ARK-ct. This is the first report demonstrating the regulation of EGFR, ERK1/2, c-Src, and fibronectin by G?? subunits in renal epithelial cells. Moreover, this work demonstrates a role for G?? heterotrimeric proteins in ANG II, but not arachidonic acid, signaling in renal epithelial cells. PMID:24920755

Alexander, Larry D; Ding, Yaxian; Alagarsamy, Suganthi; Cui, Xiaolan

2014-08-01

24

Arachidonic acid metabolism in cultured mouse keratinocytes  

SciTech Connect

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.

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

1985-07-01

25

Ear Plastic Surgery  

MedlinePLUS

... receive light-weight earrings. Does Insurance Pay for Cosmetic Ear Surgery? Insurance usually does not cover surgery solely for ... you can expect. Updated 6/11/12 Ears Cosmetic Surgery, Facelift, Rhinoplasty, Blepharoplasty

26

Ears and Altitude  

MedlinePLUS

... variety of reasons. When that occurs, the middle ear pressure cannot be equalized. The air already there is ... as pilots, are taught how to equalize their ear pressure. Anybody can learn the trick too. How to ...

27

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 ...

28

Ear tube insertion  

MedlinePLUS

... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk of ear infections. ... do not have long-term damage to their hearing or speech, even when ... many months. Ear tube insertion may be done when fluid builds ...

29

Arachidonate metabolism in bovine gallbladder muscle  

SciTech Connect

Incubation of (1-/sup 14/C)arachidonic acid (AA) with homogenates of bovine gallbladder muscle generated a large amount of radioactive material having the chromatographic mobility of 6-keto-PGF1 alpha (stable product of PGI2) and smaller amounts of products that comigrated with PGF2 alpha PGE2. Formation of these products was inhibited by the cyclooxygenase inhibitor indomethacin. The major radioactive product identified by thin-layer chromatographic mobility and by gas chromatography - mass spectrometric analysis was found to be 6-keto-PGF1 alpha. The quantitative metabolic pattern of (1-/sup 14/C)PGH2 was virtually identical to that of (1-/sup 14/C)AA. Incubation of arachidonic acid with slices of bovine gallbladder muscle released labile anti-aggregatory material in the medium, which was inhibited by aspirin or 15-hydroperoxy-AA. These results indicate that bovine gallbladder muscle has a considerable enzymatic capacity to produce PGI2 from arachidonic acid.

Nakano, M.; Hidaka, T.; Ueta, T.; Ogura, R.

1983-04-01

30

The filamentous fungus mortierella alpina , high in arachidonic acid  

Microsoft Academic Search

Arachidonic acid is not available readily, although it is widely distributed in animal tissue. We found that in some strains\\u000a ofMortierella alpina, arachidonic acid accounted for 68.5–78.8% of the total fatty acids. This is more than twice the arachidonic acid content\\u000a of any organism previously reported. The content of arachidonic acid per dry cell weight was about 25%. Our findings

Nagao Totani; Kenkichi Oba

1987-01-01

31

Prostaglandin synthase 1 gene disruption in mice reduces arachidonic acid-induced inflammation and indomethacin-induced gastric ulceration  

Microsoft Academic Search

Cyclooxygenases 1 and 2 (COX-1 and COX-2) are key enzymes in prostaglandin biosynthesis and the target enzymes for the widely used nonsteroidal anti-inflammatory drugs. To study the physiological roles of the individual isoforms, we have disrupted the mouse Ptgs1 gene encoding COX-1. Homozygous Ptgs1 mutant mice survive well, have no gastric pathology, and show less indomethacin-induced gastric ulceration than wild-type

Robert Langenbach; Scott G. Morham; Howard F. Tiano; Charles D. Loftin; Burhan I. Ghanayem; Patricia C. Chulada; Joel F. Mahler; Christopher A. Lee; Eugenia H. Goulding; Kimberly D. Kluckman; H. S. Kim; Oliver Smithies

1995-01-01

32

Ear candling: a case report.  

PubMed

We describe a case of ear candling presenting as hearing loss, and review the literature. Ear candling is considered as an alternate medical therapy for dewaxing the ears, discomfort in ears and sinuses, rhinitis, sinusitis, glue ear, colds, flu, migraines, poor or "muffled" hearing, high stress, and ringing in the ear. There is no evidence of its effectiveness, and it can actually cause damage to the ears. PMID:19958263

Zackaria, Mohamed; Aymat, Antony

2009-01-01

33

Autoimmune Inner Ear Disease (AIED)  

MedlinePLUS

... debris in the ear can cause problems. Some autoimmune disorders that can affect the ear include Cogan’s syndrome, ... even indistinguishable, from other vestibular disorders. Diagnosing an autoimmune disorder as the cause of inner ear symptoms can ...

34

Free fatty acid-induced platelet aggregation: studies with solubilized and nonsolubilized fatty acids.  

PubMed

The aggregation response of washed porcine platelets to the sodium salts of stearic, oleic, palmitic, and myristic acids was analyzed turbidometrically. The fatty acids were prepared as aqueous suspensions and as taurocholate- or albumin-solubilized systems. The final concentration of fatty acid in the platelet preparation varied between 70 and 600 microM. This range was within or below the normal physiological limits of 300-1200 microM. Platelet aggregation was observed with both the suspended and taurocholate-solubilized fatty acids. The extent of platelet aggregate formation increased with the fatty acid concentration and chain length. With the exception of stearate, the taurocholate-solubilized fatty acids were more active than the suspensions. Albumin-solubilized fatty acids were devoid of platelet aggregating activity. Particle-size analysis of the solubilized fatty acids indicated that fatty acid precipitation had occurred subsequent to the addition of taurocholate-solubilized fatty acids to the platelets. This precipitation did not occur with the albumin-solubilized systems, suggesting that the fatty acids must assume a particulate physical state to induce aggregation. Platelet aggregation induced by fatty acids was not inhibited by 80 nM epoprostenol, 75 microM alprostadil, or 150 microM indomethacin. This finding indicated that the fatty acid-induced platelet aggregation was independent of cyclic AMP-related calcium shift, cyclooxygenase-arachidonate, or granular nucleotide release mechanisms. PMID:6101166

Zentner, G M; Cardinal, J R; Kim, S W

1981-09-01

35

Control of arachidonic acid release in chick muscle cultures  

NASA Technical Reports Server (NTRS)

Cultures from thigh muscles of 12 day old embryonic chicks are utilized to examine arachidonic release, prostaglandin (PG) biosynthesis, and protein synthesis. The preparation of the cultures is described. It is observed that exogenous arachidonic acid is formed into photsphatidylethanolamine and phosphatidylcholine, is released by a calcium ionosphere or phospholiphase simulator, and is the substrate for the biosynthesis of PG; the epidermal growth factor and PGF do not stimulate protein synthesis over the basal levels. The relationship between arachidonate release and melittin is studied. The data reveal that a change in intracellular calcium stimulates phospholiphase activity, arachidonate release, and PG synthesis in chick muscle culture.

Templeton, G. H.; Padalino, M.; Wright, W.

1985-01-01

36

Ear Injuries (For Parents)  

MedlinePLUS

... They also might need listening therapy with an audiologist (hearing specialist). Make sure to call your doctor ... ear, nose, and throat specialist and possibly an audiologist to figure out the next step to take. ...

37

Ear Infections in Children  

MedlinePLUS

... to the middle ear, drain fluid, and keep air pressure at a steady level between the nose and ... behind it. Tympanometry, which uses sound tones and air pressure, is a diagnostic test a doctor might use ...

38

Luteolin prevents uric acid-induced pancreatic ?-cell dysfunction  

PubMed Central

Abstract 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

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

2014-01-01

39

Arachidonic acid metabolites in pathogenic yeasts  

PubMed Central

Although most of what is known about the biology and function of arachidonic acid metabolites comes from the study of mammalian biology, these compounds can also be produced by lower eukaryotes, including yeasts and other fungi. It is also in this group of organisms that the least is known about the metabolic pathways leading to the production of these compounds as well as the functions of these compounds in the biology of fungi and yeasts. This review will deal with the discovery of oxylipins from polyunsaturated fatty acids, and more specifically the arachidonic acid derived eicosanoids, such as 3-hydroxy eicosatetraenoic acid, prostaglandin F2? and prostaglandin E2, in yeasts starting in the early 1990s. This review will also focus on what is known about the metabolic pathways and/or proteins involved in the production of these compounds in pathogenic yeasts. The possible roles of these compounds in the biology, including the pathology, of these organisms will be discussed. PMID:22873782

2012-01-01

40

Middle Ear Infections and Ear Tube Surgery (For Parents)  

MedlinePLUS

... the nose — called the eustachian tube — equalizes the air pressure between the middle ear and the outside world. ( ... or swallowing, the eustachian tubes are adjusting the air pressure in the middle ears.) Infection Bacteria or viruses ...

41

Digital ear scanner : measuring the compliance of the ear  

E-print Network

This paper seeks to resolve the biggest problem with hearing aids, their physical fit. By digitally scanning the ear canal and taking the dynamics of the ear into account the performance and comfort of a hearing aid can ...

Hernandez-Stewart, Daniel

2010-01-01

42

ORIGINAL ARTICLE Visualization of Oleic Acid-induced Transdermal Diusion  

E-print Network

£uores- cence and the transdermal £uorescent model drug spatial distributions were imaged simultaneously overORIGINAL ARTICLE Visualization of Oleic Acid-induced Transdermal Di¡usion Pathways Using Two-based model drug intensity emission at a di¡erent wavelength range of the £uorescence emission spectrum

So, Peter

43

Hearing, Ear Infections, and Deafness  

MedlinePLUS

... Health Info Hearing, Ear Infections, and Deafness DefaultPage Hearing, Ear Infections, and Deafness Diseases and Conditions Age- ... for parents Communication Methods & Devices for People With Hearing Loss American Sign Language Assistive Devices for People ...

44

From Ear to Brain  

ERIC Educational Resources Information Center

In this paper Doreen Kimura gives a personal history of the "right-ear effect" in dichotic listening. The focus is on the early ground-breaking papers, describing how she did the first dichotic listening studies relating the effects to brain asymmetry. The paper also gives a description of the visual half-field technique for lateralized stimulus…

Kimura, Doreen

2011-01-01

45

Middle Ear Infections (For Parents)  

MedlinePLUS

... the eardrum. There's no single best approach for treating all middle ear infections. In deciding how to manage your child's ear infection, ... to large groups of other kids, such as in child-care centers. Because multiple upper respiratory infections may also lead to frequent ear infections, ...

46

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...

47

Production of arachidonic acid by Mortierella alpina ATCC 32222  

Microsoft Academic Search

Summary WhenMortierella alpina ATCC 32222 was incubated in a glucose salts medium at 25°C the biomass (17.5 g\\/l) contained 9.62% arachidonic acid which amounted to 54% (w\\/w) of total biomass lipids. When the glucose concentration in the medium was varied from 0 to 150 g\\/l, the percentage of arachidonic acid in biomass and in lipids was highest at a glucose

Pramod K. Bajpai; Pratima Bajpai; Owen P. Ward

1991-01-01

48

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

SciTech Connect

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.

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

1989-09-01

49

Cyclic AMP and arachidonic acid: a tale of two pathways.  

PubMed

Increasing evidence in recent years has demonstrated the regulatory effects of arachidonic acid and its metabolites on steroid hormone production in various steroidogenic tissues. In trophic hormone-stimulated steroidogenesis, arachidonic acid is rapidly released from phospholipids. This release is dependent upon hormone-receptor interaction and inhibition of arachidonic acid release results in an inhibition of steroidogenesis. Several of the earlier studies indicated that arachidonic acid acts at the rate-limiting step of steroid biosynthesis, the transfer of substrate cholesterol to the inner mitochondrial membrane, but the manner in which this occurred was not clear. Recently it has been demonstrated that arachidonic acid release can participate in the regulation of gene expression of the steroidogenic acute regulatory (StAR) protein which mediates cholesterol transfer to the inner mitochondrial membrane. These studies suggest that this fatty acid may be instrumental in transducing a signal from trophic hormone/receptor interaction to the nucleus utilizing a pathway different from the reported cyclic AMP pathway. It is possible that these two pathways cooperate and serve to co-regulate transcription factors, resulting in StAR gene expression and subsequent steroid production. This hypothesis may serve to explain and co-ordinate previous observations on the roles of cyclic AMP (cAMP) and arachidonic acid in steroid hormone biosynthesis. PMID:10630400

Wang, X; Stocco, D M

1999-12-20

50

Save Your Ears  

NSDL National Science Digital Library

This game depicts a woman going through her day, faced with various loud sounds. In each situation, she has the choice of how to deal with the loud sound: Ear Plugs, Turn It Down, Move Away, or Do Nothing. You only have 3 of each choice available, symbolized by cards on screen. Your goal is to reach the end of the game with undamaged hearing and one set of earplugs, so you can enjoy an awesome rock concert. After each decision, you find out whether your hearing was damaged and if you made the best choice.

Omsi

2010-01-01

51

Otoscopic exam of the ear (image)  

MedlinePLUS

... intrument which is used to look into the ear canal. The ear speculum (a cone-shaped viewing piece of the otoscope) is slowly inserted into the ear canal while looking into the otoscope. The speculum is ...

52

Successful Bilateral Composite Ear Reattachment  

PubMed Central

Summary: A successful bilateral ear composite graft nonmicrosurgical reattachment is presented. In cases where suitable vessels are unavailable for microsurgical revascularization, the reconstructive challenge can be formidable for salvaging the unique anatomic and aesthetic structure of the ear. The case is presented of an 18-year-old woman who was a victim of an assault wherein both of her ears were intentionally amputated by her attacker. She underwent successful surgical reattachment followed by a postoperative regimen of hyperbaric oxygen, cooling, and meticulous wound care. The patient achieved 100% survival of her left ear graft and 95% survival of her right ear graft. Clinical photographs at 18 months are presented, along with a discussion of the possible implications for other reconstructive applications. PMID:25289367

2014-01-01

53

Arachidonic acid production by Mortierella alpina grown on solid substrates  

Microsoft Academic Search

Mortierella alpina grown in solid state fermentations on cereal substrates gave up to 16% lipid in the final biomass. Arachidonic was at 50% of total fatty acids, with a yield of 36 mg\\/g of original substrate. Microbial lipid production was successfully scaled up to use 5-kg dry substrate batches.

S. Stred'anská; D. Slugeti; M. Stred'anský; J. Grego

1993-01-01

54

[Progress in production of arachidonic acid by Mortierella alpina and genetic modification].  

PubMed

Arachidonic acid, as an important polyunsaturated fatty acid, is identified as potential food additives or pharmaceuticals for their biological activities. In recent years, arachidonic acid production by Mortierella alpina is becoming a research highlight. The prophase relevant researches focused on the mutagenic breeding and fermentation optimization. With the depth of investigation, the advancement concerning pathway for the biosynthesis of arachidonic acid in Mortierella alpina has been made. In this review, we summarized the prophase work briefly. Mainly, we discussed the biosynthesis pathway of arachidonic acid, the key enzymes, the construction of transformation system and the genetic modification. In addition, the prospect of microorganism arachidonic acid production is put forward. PMID:21141113

Cong, Leilei; Peng, Chao; Ji, Xiaojun; Li, Zhiyong; You, Jiangying; Lu, Jinmiao; Huang, He

2010-09-01

55

Optimization of arachidonic acid production by fed-batch culture of Mortierella alpina based on dynamic analysis  

Microsoft Academic Search

Arachidonic acid is an essential fatty acid in human nutrition. Improvement of arachidonic acid production by fungus Mortierella alpina was investigated. The time courses of fungal biomass, lipid and arachidonic acid production with different initial glucose concentrations were examined to study dynamic characteristics of arachidonic acid production on a shaker flask scale. Results showed that low initial concentrations of glucose

Min Zhu; Long-Jiang Yu; Wei Li; Peng-Peng Zhou; Chun-Yan Li

2006-01-01

56

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

PubMed Central

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

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

2012-01-01

57

Otoacoustic Emissions from a Nonvertebrate Ear  

Microsoft Academic Search

Otoacoustic emissions are produced by the inner ear of vertebrates and result from the active and nonlinear processing of input sound by sensory hair cells. We recorded pronounced distortion-product otoacoustic emissions from the ear of the grasshopper, and these emissions proved remarkably similar to those described for the mammalian ear. This is despite the fact that the grasshopper ear is

M. Kössl; G. S. Boyan

1998-01-01

58

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

of biological membranes, a presumed site at which these compounds inhibit lipid peroxidation. Bovine brain microvessel endothelial cells (BMECs) were labeled with diphenylhexatriene fluorophores and interactions with cell membranes characterized...,6- diphenyl-1,3,5-hexatriene (DPH) and 1-(4-trimethyammoniumphenyl)-6-diphenyl-1,3,5-hexatriene, p- toluenesulfonate (TMA-DPH) were purchased from Molecular Probes, Eugene, OR. Cholesterol, heparin sulfate, ascorbic acid, fluorescein sodium, 1,4-bis[4-methyl...

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

1995-09-01

59

What Is an Ear Infection?  

MedlinePLUS

... For Kids For Parents MORE ON THIS TOPIC Movie: Ears Your ... Nemours Web site. Note: All information on KidsHealth® is for educational purposes only. For specific medical advice, diagnoses, and ...

60

Ototoxicity (Ear Poisoning) (For Parents)  

MedlinePLUS

... may recommend that your child regularly see an audiologist (hearing specialist) or vestibular therapist (someone trained in ... or balance abilities, or refer you to an audiologist or otolaryngologist (ear, nose, and throat specialist) for ...

61

Inhibitors of the arachidonic acid cascade: interfering with multiple pathways.  

PubMed

Modulators of the arachidonic acid cascade have been in the focus of research for treatments of inflammation and pain for several decades. Targeting this complex pathway experiences a paradigm change towards the design and development of multi-target inhibitors, exhibiting improved efficacy and less undesired side effects. This minireview summarizes recent developments in the field of designed multi-target ligands of the arachidonic acid cascade. In addition to the well-known dual inhibitors of 5-lipoxygenase and cyclooxygenase-2 such as licofelone, very recent developments are discussed. Especially, multi-target inhibitors interfering with the cytochrome P450 pathway via inhibition of soluble epoxide hydrolase seem to offer a novel opportunity for development of novel anti-inflammatory drugs. PMID:24015667

Meirer, Karin; Steinhilber, Dieter; Proschak, Ewgenij

2014-01-01

62

Influence of arachidonic acid metabolism on cell proliferation and apoptosis  

Microsoft Academic Search

\\u000a Research over the past three decades has revealed that arachidonic acid (AA) and oxygen-containing derivatives of AA, termed\\u000a eicosanoids, play pivotal roles in controlling key cellular events that lead to acute and chronic inflammation (for review,\\u000a see [1]). While it has been suggested for more than 50 years that diets high in certain fatty acids stimulate tumor development\\u000a in animals,

Floyd H. Chilton; Carl E. Clay; Anthony Trimboli; Alfred N. Fonteh

63

The Productive Conformation of Arachidonic Acid Bound to Prostaglandin Synthase  

Microsoft Academic Search

Prostaglandin H synthase-1 and -2 (PGHS-1 and -2) catalyze the committed step in prostaglandin synthesis and are targets for nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin. We have determined the structure of PGHS-1 at 3 angstrom resolution with arachidonic acid (AA) bound in a chemically productive conformation. The fatty acid adopts an extended L-shaped conformation that positions the 13proS hydrogen of

M. G. Malkowski; S. L. Ginell; W. L. Smith; R. M. Garavito

2000-01-01

64

Arachidonic acid assimilation by thrombocytes from white carneau pigeons  

SciTech Connect

The metabolism of arachidonic acid was investigated using thrombocyte-enriched-plasma from RBWC and WC-II white carneau pigeons, which differ genetically in their susceptibility to atherosclerosis. Thrombocytes were incubated at 42 C with (/sup 14/C) arachidonate in Puck's solution. After a 1 hour labeling period the WC-II cells had taken up 69% and RBWC 77% of the (/sup 14/C)arachidonate from the medium. When 8,11,14-eicosatrienoic acid or 5,8,11,14,17-eicosapentaenoic acid were added to incubation media the (/sup 14/C) uptake was reduced in each type cell, with WC-II exhibiting the greatest effect. Release of (/sup 14/C)molecules from cells labeled with (/sup 14/)Carachidonate was studied using calcium ionophore and indomethacin. Indomethacin inhibited (/sup 14/C) molecule release similarly in both RBWC and WC-II cells. Calcium ionophore was twice as effective in stimulating (/sup 14/C)molecule release from WC-II than RBWC cells. Therefore, the WE-II cells (from pigeons greater in susceptibility to atherosclerosis) are more sensitive to calcium ionophore than the REWC cells.

Saxon, D.J.; Blankenship, T.

1986-03-01

65

Stereocontrol of Arachidonic Acid Oxygenation by Vertebrate Lipoxygenases  

PubMed Central

Animal lipoxygenases (LOXs) are classified according to their specificity of arachidonic acid oxygenation, and previous sequence alignments suggested that S-LOXs contain a conserved Ala at a critical position at the active site but R-LOXs carry a Gly instead. Here we cloned, expressed, and characterized a novel LOX isoform from the model vertebrate Danio rerio (zebrafish) that carries a Gly at this critical position, classifying this enzyme as putative arachidonic acid R-LOX. Surprisingly, the almost exclusive arachidonic acid oxygenation product was 12S-H(p)ETE (hydro(pero)xyeicosatetraenoic acid), and extensive mutation around Gly-410 failed to induce R-lipoxygenation. This finding prompted us to explore the importance of the corresponding amino acids in other vertebrate S-LOXs. We found that Ala-to-Gly exchange in human 15-LOX2 and human platelet 12-LOX induced major alterations in the reaction specificity with an increase of specific R-oxygenation products. For mouse 5-LOX and 12/15-LOX from rabbits, men, rhesus monkeys, orangutans, and mice, only minor alterations in the reaction specificity were observed. For these enzymes, S-HETE (hydroxyeicosatetraenoic acid) isomers remained the major oxygenation products, whereas chiral R-HETEs contributed only 10–30% to the total product mixture. Taken together these data indicate that the Ala-versus-Gly concept may not always predict the reaction specificity of vertebrate LOX isoforms. PMID:21880725

Jansen, Christian; Hofheinz, Katharina; Vogel, Robert; Roffeis, Jana; Anton, Monika; Reddanna, Pallu; Kuhn, Hartmut; Walther, Matthias

2011-01-01

66

Daily fluctuations of middle ear pressure in atelectatic ears.  

PubMed

The position of the drum of 84 atelectatic ears, of patients 5 to 79 years old, was examined with the help of the operating microscope at different times of the day. All ears were found to be atelectatic during the daytime, yet on the patients' awakening in the morning, 37.73% of the drums of the adolescents' and adults' ears were found to be inflated, usually even hyperinflated. None of the children showed an inflated eardrum in the morning. All eardrums that were inflated in the morning returned to their original atelectatic position within an average of 54.56 minutes after awakening. This observation illustrates another fluctuating aspect of the atelectatic condition. PMID:2310136

Luntz, M; Sadé, J

1990-03-01

67

Ear disorders in scuba divers.  

PubMed

History of underwater diving dates back to antiquity. Breath-hold technique in diving was known to the ancient nations. However, deep diving progressed only in the early decades of the 19th century as the result of advancements in efficient underwater technologies which subsequently led to invention of sophisticated sets of scuba diving in the 20th century. Currently, diving is performed for various purposes including commercial, recreational, military, underwater construction, oil industry, underwater archeology and scientific assessment of marine life. By increasing popularity of underwater diving, dive-related medical conditions gradually became more evident and created a new challenge for the health care professionals, so that eventually, a specialty the so-called "diving medicine" was established. Most of the diving-associated disorders appear in the head and neck. The most common of all occupational disorders associated with diving are otologic diseases. External otitis has been reported as the most common otolaryngologic problem in underwater divers. Exostosis of the external ear canal may be formed in divers as the result of prolonged diving in cold waters. Other disorders of the ear and paranasal sinuses in underwater divers are caused by barometric pressure change (i.e., barotraumas), and to a lesser extent by decompression sickness. Barotrauma of the middle ear is the most prevalent barotrauma in divers. The inner ear barotraumas, though important, is less common. The present paper is a brief overview of diving-related ear disorders particularly in scuba divers. PMID:23022815

Azizi, M H

2011-01-01

68

3D printed bionic ears.  

PubMed

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

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

69

3D Printed Bionic Ears  

PubMed Central

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

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

70

[Ear diseases and diabetes mellitus].  

PubMed

In the literature there is very little information about the importance of diabetes mellitus for ear diseases. Therefore, this article gives an overview about contact points between endocrinological and otological problems in patients with diseases of the ear and pre-existing diabetes mellitus. In particular the focus is on the impact of diabetes mellitus on patients with external otitis, malignant external otitis, otitis media, sudden sensorineural hearing loss and slowly progressive hearing loss. Diseases, such as osteomyelitis of the lateral skull base, sudden and slowly progressive hearing loss are also discussed in detail. PMID:25370360

Avetisyan, N; Lautermann, J

2014-11-01

71

Costs and benefits of jasmonic acid induced responses in soybean.  

PubMed

In response to herbivory, plants have evolved defense strategies to reduce herbivore preference and performance. A strategy whereby defenses are induced only upon herbivory can mitigate costs of defense when herbivores are scarce. Although costs and benefits of induced responses are generally assumed, empirical evidence for many species is lacking. Soybean (Glycine max L. Merr.) has emerged as a model species with which to address questions about induced responses. To our knowledge, this is the first study to examine the fitness costs and benefits of jasmonic acid-induced responses by soybean in the absence and presence of soybean loopers (Chrysodeix includens Walker) (Lepidoptera: Noctuidae). In a greenhouse experiment we demonstrated that soybean induction was costly. Induced plants produced 10.1% fewer seeds that were 9.0% lighter, and had 19.2% lower germination rates than noninduced plants. However, induction provided only modest benefits to soybeans. In a choice experiment, soybean loopers significantly preferred leaves from noninduced plants, consuming 62% more tissue than from induced plants. Soybean loopers that fed on plants that were previously subjected to treatment with jasmonic acid matured at the same rate and to the same size as those that fed on control plants. However, at high conspecific density, soybean looper survivorship was reduced by 44% on previously induced relative to control plants. Reduced soybean looper preference and survivorship did not translate into fitness benefits for soybeans. Our findings support theoretical predictions of costly induced defenses and highlight the importance of considering the environmental context in studies of plant defense. PMID:22732613

Accamando, A K; Cronin, J T

2012-06-01

72

Coffee May Keep Your Ears from Ringing  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Coffee May Keep Your Ears From Ringing Study found ... FRIDAY, Aug. 8, 2014 (HealthDay News) -- Being a coffee lover may be good for your ears, a ...

73

Neurosensory Development in the Zebrafish Inner Ear  

E-print Network

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...

Vemaraju, Shruti

2012-02-14

74

21 CFR 878.3590 - Ear prosthesis.  

Code of Federal Regulations, 2011 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis...

2011-04-01

75

21 CFR 878.3590 - Ear prosthesis.  

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis...

2014-04-01

76

21 CFR 878.3590 - Ear prosthesis.  

Code of Federal Regulations, 2013 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis...

2013-04-01

77

21 CFR 878.3590 - Ear prosthesis.  

Code of Federal Regulations, 2012 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3590 Ear prosthesis. (a) Identification. An ear prosthesis...

2012-04-01

78

Inner Ear Drug Delivery for Auditory Applications  

PubMed Central

Many inner ear disorders cannot be adequately treated by systemic drug delivery. A blood-cochlear barrier exists, similar physiologically to the blood-brain barrier, which limits the concentration and size of molecules able to leave the circulation and gain access to the cells of the inner ear. However, research in novel therapeutics and delivery systems has led to significant progress in the development of local methods of drug delivery to the inner ear. Intratympanic approaches, which deliver therapeutics to the middle ear, rely on permeation through tissue for access to the structures of the inner ear, whereas intracochlear methods are able to directly insert drugs into the inner ear. Innovative drug delivery systems to treat various inner ear ailments such as ototoxicity, sudden sensorineural hearing loss, autoimmune inner ear disease, and for preserving neurons and regenerating sensory cells are being explored. PMID:18848590

Swan, Erin E. Leary; Mescher, Mark J.; Sewell, William F.; Tao, Sarah L.; Borenstein, Jeffrey T.

2008-01-01

79

Division of Earth Sciences (EAR) -- Dear Colleague Letter  

NSF Publications Database

Title : NSF 93-61 EAR Dear Colleague Letter Type : Letter NSF Org: GEO / EAR Date : May 12, 1993 ... of Earth Sciences (EAR) is 1 June 1993. This will be the second EAR proposal deadline since the ...

80

Ultrastructure of the Insect Ear  

Microsoft Academic Search

LIGHT microscope studies1-4 have long established that the sensory unit (chordotonal sensillum or stiftführendes Organ) of the insect ear consists of three cells, namely, the bipolar neuron, the axon of which runs directly to the central nervous system, the sheath cell, which surrounds the dendrite of the neuron, and the attachment cell, which appears to anchor the whole assembly to

E. G. Gray

1958-01-01

81

Frog eye, ear, and nostril  

NSDL National Science Digital Library

You can clearly see the frog's eye. There is an air opening near a black spot on the frog's skin. The opening to the frog's ear is covered by the round, tan membrane to the left in the picture. This membrane is called the tympanum.

Ren West (None;)

2006-08-07

82

21 CFR 870.2710 - Ear oximeter.  

Code of Federal Regulations, 2010 CFR

...2710 Ear oximeter. (a) Identification. An ear oximeter is an extravascular device used to transmit light at a known wavelength(s) through blood in the ear. The amount of reflected or scattered light as indicated by this device is used to...

2010-04-01

83

21 CFR 870.2710 - Ear oximeter.  

Code of Federal Regulations, 2011 CFR

...2710 Ear oximeter. (a) Identification. An ear oximeter is an extravascular device used to transmit light at a known wavelength(s) through blood in the ear. The amount of reflected or scattered light as indicated by this device is used to...

2011-04-01

84

Can Loud Music Hurt My Ears?  

MedlinePLUS

... Main Page The Pink Locker Society Can Loud Music Hurt My Ears? KidsHealth > Kids > Q&A > Q & A > Can Loud Music Hurt My Ears? Print A A A Text ... up? Oh! You want to know if loud music can hurt your ears . Are you asking because ...

85

Immunologic Disorders of the Inner Ear.  

ERIC Educational Resources Information Center

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)

Kinney, William C.; Hughes, Gordon B.

1997-01-01

86

21 CFR 870.2710 - Ear oximeter.  

...2710 Ear oximeter. (a) Identification. An ear oximeter is an extravascular device used to transmit light at a known wavelength(s) through blood in the ear. The amount of reflected or scattered light as indicated by this device is used to...

2014-04-01

87

Designing Medical Devices for the Ear  

NSDL National Science Digital Library

Students are introduced to engineering, specifically to biomedical engineering and the engineering design process, through a short lecture and an associated hands-on activity in which they design their own medical devices for retrieving foreign bodies from the ear canal. Through the lesson, they learn the basics of ear anatomy and how ear infections occur and are treated. Besides antibiotic treatment, the most common treatment for chronic ear infections is the insertion of ear tubes to drain fluid from the middle ear space to relieve pressure on the ear drum. Medical devices for this procedure, a very common children's surgery, are limited, sometimes resulting in unnecessary complications from a simple procedure. Thus, biomedical engineers must think creatively to develop new solutions (that is, new and improved medical devices/instruments) for inserting ear tubes into the ear drum. The class learns the engineering design process from this ear tube example of a medical device design problem. In the associated activity, students explore biomedical engineering on their own by designing prototype medical devices to solve another ear problem commonly experienced by children: the lodging of a foreign body (such as a pebble, bead or popcorn kernel) in the ear canal. The activity concludes by teams sharing and verbally analyzing their devices.

Biomedical Engineering

88

Arachidonic Acid Is Preferentially Metabolized by Cyclooxygenase2 to Prostacyclin and Prostaglandin E2  

Microsoft Academic Search

The two cyclooxygenase isoforms, cyclooxygenase-1 and cyclooxygenase-2, both metabolize arachidonic acid to prostaglandin H2, which is subsequently processed by downstream enzymes to the various prostanoids. In the present study, we asked if the two isoforms differ in the profile of prostanoids that ultimately arise from their action on arachidonic acid. Resident peritoneal macro- phages contained only cyclooxygenase-1 and synthe- sized

Thomas G. Brock; Robert W. McNish; Marc Peters-Golden

1999-01-01

89

Polychlorinated biphenyls induce arachidonic acid release in human platelets in a tamoxifen sensitive manner via  

E-print Network

: PCB, polychlorinated biphenyls PLA2, phospholipase A2 cPLA2, cytosolic PLA 12-HETE, 12(S)-hydroxy-5, the effects of PCBs on eicosanoid formation, arachidonic acid release and cytosolic phospholipase A2-a (cPLA2. The release of arachidonic acid and the formation of 12-HETE was completely blocked by the cPLA2-a inhibitors

Gelb, Michael

90

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

PubMed Central

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

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

2014-01-01

91

Inner ear deficits after chronic otitis media.  

PubMed

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

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

2014-08-01

92

Modulation of arachidonic acid metabolism by bovine alveolar macrophages  

SciTech Connect

The purpose of this study were to identify the arachidonic acid (AA) metabolites produced by cultured bovine alveolar macrophages (AM), to investigate the effects of various stimuli on the production of those metabolites, and to study the effect of interferons and lipopolysaccharide on AA metabolism by AM. Initial studies were conducted to ascertain which AA metabolites are produced by bovine alveolar macrophages. Cultured macrophages were labeled with tritiated arachidonic acid and stimulated with calcium ionophore A23187. The radiolabeled AA metabolites released were identified using reverse-phase high-performance liquid chromatography. The production of LTB{sub 4}, TXB{sub 2}, and PGF{sub 2{alpha}} by AM stimulated with A23187 or opsonized zymosan (OPZ) was measured using radioimmunoassay. Finally, the effects of recombinant bovine interferon alpha{sub 1}-1 (IFN-{alpha}{sub 1}-1), recombinant bovine interferon gamma (IFN-{gamma}), and lipopolysaccharide (LPS) derived from Escherichia coli 0111:B4 on the AA metabolism of bovine AM were investigated. These studies indicate that appropriately stimulated bovine AM are the source of a number of AA metabolites. Furthermore, the production of these metabolites may be dramatically altered by exposure of the AM to IFNs or LPS. Such exposure could occur in vivo during gram negative bacterial pneumonias following viral infections. Because AA metabolites are intimately involved in the inflammatory process, it is possible that AM may contribute to the development of pulmonary inflammation in certain situations.

O'Sullivan, M.G.

1989-01-01

93

The War of Jenkins' Ear  

PubMed Central

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

Graboyes, Evan M.; Hullar, Timothy E.

2012-01-01

94

Local Inner Ear Drug Delivery and Pharmacokinetics  

PubMed Central

Summary A number of drugs are in widespread clinical use for the treatment of inner ear disorders by applying them directly to the inner ear. Many new substances and drug delivery systems specific to the inner ear are under development, and in some cases are undergoing evaluations in animal experiments and in clinical studies. The pharmacokinetics of drugs in the inner ear, however, is not well defined and the field is plagued by technical problems in obtaining pure samples of the inner ear fluids for analysis. Nevertheless, a basic understanding of the mechanisms of drug dispersal in the inner ear has emerged that facilitates the design and interpretation of future pharmacokinetic studies. PMID:16214674

Salt, Alec N.; Plontke, Stefan K.R.

2008-01-01

95

Sensory innervation of the ear drum and middle-ear mucosa: Retrograde tracing and immunocytochemistry  

Microsoft Academic Search

The distribution and origin of nerve fibers of presumed sensory nature in the ear drum and middle-ear mucosa of the rat were studied by a retrograde tracing technique in combination with immunocytochemistry.

R. Uddman; T. Grunditz; A. Larsson; F. Sundler

1988-01-01

96

[Hypopharyngeal carcinoma and red ear drum].  

PubMed

A 46-year-old male patient with an unresectable hypopharyngeal carcinoma was treated with primary radio-chemotherapy. At follow-up, the patient presented with a red ear drum and combined hearing loss. Because of radiotherapy-induced tubal dysfunction, paracentesis was performed. Biopsy of the polypoid middle ear mucosa revealed petrous bone infiltration of hypopharyngeal carcinoma. MRI studies revealed paracarotideal tumor infiltration to the petrous bone and the middle ear arising from a cervical retropharyngeal lymph node metastasis. PMID:20963385

Bender, B; Widmann, G; Riechelmann, H; Schmutzhard, J

2011-04-01

97

Arachidonic acid, 12- and 15-hydroxyeicosatetraenoic acids, eicosapentaenoic acid, and phospholipase A2 induce starfish oocyte maturation.  

PubMed

In starfish oocyte maturation (meiosis reinitiation) is induced by the natural hormone 1-methyladenine (1-Me-Ade). This paper shows that arachidonic acid (AA) induces oocyte maturation at concentrations above 0.5 microM. This maturation shares many characteristics with 1-MeAde-induced maturation: same kinetics, same required contact time, same stimulations of protein phosphorylation and sodium influx. Although calcium facilitates the AA-induced but not the 1-MeAde-induced maturation, AA, like 1-MeAde, does not stimulate the uptake of calcium. Calcium does not facilitate the uptake of AA by oocytes. Out of 36 different fatty acids (saturated and unsaturated), only eicosatetraenoic (AA) and eicosapentaenoic acids were found to mimic 1-MeAde. Calcium-dependent phospholipases A2 from bee venom and Naja venom also induce maturation (0.1-1 unit/ml) when added externally to the oocytes. Phospholipase A2 inhibitors (quinacrine, bromophenacylbromide) block maturation; inhibition is reversed by increasing the 1-MeAde concentration and only occurs during the hormone-dependent period. AA is usually metabolized through oxidation by cyclooxygenase or lipoxygenase. Cyclooxygenase inhibitors (acetylsalicylic acid, indomethacin, tolazoline) do not block maturation; prostaglandins E2, D2, F2 alpha, I2, and thromboxane B2 do not induce meiosis reinitiation. On the other hand, lipoxygenase inhibitors (quercetin, butylated hydroxytoluene, and eicosatetraynoic acid) block 1-MeAde-induced maturation; although leukotrienes (A4, B4, C4, D4, E4) have no effects on oocytes, two other lipoxygenase products, 12- and 15-hydroxyeicosatetraenoic acids (and their corresponding hydroperoxy-) induce oocyte maturation (around 1 microM). The possible mode of action of the fatty acids inducing oocyte maturation is discussed. PMID:6094288

Meijer, L; Guerrier, P; Maclouf, J

1984-12-01

98

Molecular Mechanisms of Inner Ear Development  

PubMed Central

The inner ear is a structurally complex vertebrate organ built to encode sound, motion, and orientation in space. Given its complexity, it is not surprising that inner ear dysfunction is a relatively common consequence of human genetic mutation. Studies in model organisms suggest that many genes currently known to be associated with human hearing impairment are active during embryogenesis. Hence, the study of inner ear development provides a rich context for understanding the functions of genes implicated in hearing loss. This chapter focuses on molecular mechanisms of inner ear development derived from studies of model organisms. PMID:22855724

Wu, Doris K.; Kelley, Matthew W.

2012-01-01

99

Real-Ear to Coupler Difference in Patients with Ear Drum Perforation  

Microsoft Academic Search

The aim of this study is to investigate the effects of ear drum perforation on real-ear to coupler difference (RECD) in adults. RECD was measured using a probe tube microphone system in 22 patients with ear drum perforations. Twenty-two normal subjects served as controls. For normal subjects, RECD was in good agreement with the values reported in the literature. For

Tien-Chen Liu; Kai-Nan Lin

1999-01-01

100

A middle ear microphone design based on the physiology of the ear  

Microsoft Academic Search

Contrary to present external microphones, the proposed middle ear microphone does not measure the sound pressure but the acoustic deflection of a middle ear bone caused by an incoming pressure wave at the ear drum. By means of a seismic inertial transducer, minute vibrations in the range from 0.1 to 10 kHz should be measured. The innovation of our new

M. Sachse; W. Hortschitz; F. Kohl; J. Schalko; F. Keplinger

2010-01-01

101

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

E-print Network

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. The PDEs also facilitates an alternative sound amplification method for hearing aid design. Department

Xin, Jack

102

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 ...

103

The NADPH-oxidase-associated H+ channel is opened by arachidonate.  

PubMed Central

The H+ channel associated with the generation of O2.- by NADPH oxidase and the oxidase itself must both be activated in response to stimuli (e.g. phorbol esters, chemotactic peptides, certain fatty acids). We have investigated the effects of membrane potential, an imposed pH gradient and a combination of the two (the protonmotive force) on the H+ conductivity of the cytoplast membrane. H+ conductivity was observed only in the presence of arachidonate and not in its absence. In the presence of arachidonate, H+ movement was determined by the protonmotive force. The effect of arachidonate was probably on a channel, since this fatty acid did not significantly increase the H+ permeability of artificial phospholipid membranes. It appears, therefore, that arachidonate is required both for the activation of O2.- production and the associated H(+)-channel-mediated efflux. PMID:1373602

Henderson, L M; Chappell, J B

1992-01-01

104

Value of Ear Endoscopy in Cholesteatoma Surgery  

Microsoft Academic Search

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

M. Badr-el-Dine

2002-01-01

105

INNER EAR EMBRYOGENESIS: GENETIC AND ENVIRONMENTAL DETERMINANTS  

EPA Science Inventory

The anatomy and developmental molecular genetics of the inner ear from establishment of the otic placode to formation of the definitive cochlea and vestibular apparatus will be reviewed and the complex 3-D structural changes that shape the developing inner ear will be illustrated...

106

Ear Biometrics in Human Identification A Dissertation  

E-print Network

Biometrics are physical or behavioral characteristics that can be used for hu- man identification. SecurityEar 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

Bowyer, Kevin W.

107

Genetic Requirement for Pneumococcal Ear Infection  

Microsoft Academic Search

BackgroundEar infection or otitis media (OM) accounts for most bacterial respiratory infections in children in both developed and developing nations. Streptococcus pneumoniae, nontypeable Haemophilus influenzae, and Moraxella catarrhalis are the major OM pathogens. However, little is known about the genetic basis of bacterial OM largely due to practical difficulties in conducting research in ear infection models and genetically manipulating clinical

Huaiqing Chen; Yueyun Ma; Jun Yang; Christopher J. O'Brien; Scott L. Lee; Joseph E. Mazurkiewicz; Sauli Haataja; Jing-Hua Yan; George F. Gao; Jing-Ren Zhang; Debbie Fox

2008-01-01

108

Ultrasound Characterization of Middle Ear Effusion  

PubMed Central

Purpose To further enhance and assess the ability to characterize middle ear effusion (MEE) using non-invasive ultrasound technology. Materials and Methods This is a prospective unblinded comparison study. Fifty-six children between the ages of 6 months and 17 years scheduled to undergo bilateral myringotomy with pressure equalization tube placement were enrolled. With the child anesthetized, the probe was placed into the external ear canal after sterile water was inserted. Ultrasound recordings of middle ear contents were analyzed by computer algorithm. Middle ear fluid was collected during myringotomy and analyzed for bacterial culture and viscosity. Results Ultrasound waveforms yielded a computer algorithm interpretation of middle ear contents in 66% of ears tested. When a result was obtained, the sensitivity and specificity for successfully characterizing middle ear fluid content as either void of fluid, thick fluid (mucoid), or thin fluid (serous or purulent) was at least 94%. Mucoid effusions had higher measured viscosity values (P=0.002). Viscosity measures were compared to culture result, and those with low viscosity (thin consistency) had a higher likelihood of having a positive culture (P=0.048). Conclusion The device sensitivity and specificity for fluid detection was 94% or greater among interpretable waveforms (66% of those tested). Although this technology provides important information of the middle ear effusion presence and characteristic, further technological improvements are needed. PMID:23084430

Seth, Rahul; Discolo, Christopher M; Palczewska, Grazyna M; Lewandowski, Jan J; Krakovitz, Paul R

2012-01-01

109

Playing by Ear: Foundation or Frill?  

ERIC Educational Resources Information Center

Many people divide musicians into two types: those who can read music and those who play by ear. Formal music education tends to place great emphasis on producing musically literate performers but devotes much less attention to teaching students to make music without notation. Some would suggest that playing by ear is a specialized skill that is…

Woody, Robert H.

2012-01-01

110

Stem Cell Therapy for the Inner Ear  

PubMed Central

In vertebrates, perception of sound, motion, and balance is mediated through mechanosensory hair cells located within the inner ear. In mammals, hair cells are only generated during a short period of embryonic development. As a result, loss of hair cells as a consequence of injury, disease, or genetic mutation, leads to permanent sensory deficits. At present, cochlear implantation is the only option for profound hearing loss. However, outcomes are still variable and even the best implant cannot provide the acuity of a biological ear. The recent emergence of stem cell technology has the potential to open new approaches for hair cell regeneration. The goal of this review is to summarize the current state of inner ear stem cell research from a viewpoint of its clinical application for inner ear disorders to illustrate how complementary studies have the potential to promote and refine stem cell therapies for inner ear diseases. The review initially discusses our current understanding of the genetic pathways that regulate hair cell formation from inner ear progenitors during normal development. Subsequent sections discuss the possible use of endogenous inner ear stem cells to induce repair as well as the initial studies aimed at transplanting stem cells into the ear. PMID:22514095

Okano, Takayuki

2012-01-01

111

Reading disability and middle ear disease.  

PubMed Central

The association between specific reading disability and middle ear disease was investigated in a longitudinal study of 962 children followed from age 5 to 11. No significant differences were found in the prevalence of middle ear abnormalities between the reading disabled group (n = 49) and the remainder. PMID:3707193

Share, D L; Chalmers, D; Silva, P A; Stewart, I A

1986-01-01

112

Cutaneous lesions of the external ear  

PubMed Central

Skin diseases on the external aspect of the ear are seen in a variety of medical disciplines. Dermatologists, othorhinolaryngologists, general practitioners, general and plastic surgeons are regularly consulted regarding cutaneous lesions on the ear. This article will focus on those diseases wherefore surgery or laser therapy is considered as a possible treatment option or which are potentially subject to surgical evaluation. PMID:18261212

Sand, Michael; Sand, Daniel; Brors, Dominik; Altmeyer, Peter; Mann, Benno; Bechara, Falk G

2008-01-01

113

Evidence for, and taxonomic value of, an arachidonic acid cascade in the lipomycetaceae  

Microsoft Academic Search

By using specific inhibitors of the lipoxygenase and cyclo-oxygenase pathways, arachidonic acid metabolites with similar sensitivities towards these inhibitors as in humans, were detected inDipodascopsis uninucleata. The taxonomic value of aspirin sensitive arachidonic acid metabolites in the Lipomycetaceae was next assessed. No metabolites of which the production is inhibited by aspirin were detected in strains representing the following species:Lipomyces starkeyi,

Johan L. F. Kock; Dennis J. Coetzee; Martie S. Dyk; Michelle Truscott; Alfred Botha; Ockert P. H. Augustyn

1992-01-01

114

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

Microsoft Academic Search

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

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

2000-01-01

115

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

E-print Network

IDENTIFICATION QF ARACHIDONIC ACID AND ITS METABOLISM IN GULF OF MEXICO SHRIMP A Thesis by MARTHA LAE LILLY Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement fcr the degree of MASTER QF... SCIENCE August 1980 Major Subject: Biochemistry IDENTIFICATION OF ARACHIDONIC ACID AND ITS METABOLISM IN GULF OF MEXICO SHRIMP A Thesis by MARTHA LAE LILLY Approved as to style and content by: airman of Committee) (M (Member) ead of Department...

Lilly, Martha Lae

2012-06-07

116

An inexpensive medium for production of arachidonic acid by Mortierella alpina  

Microsoft Academic Search

  \\u000a The production of arachidonic acid was studied in the fungus Mortierella alpina using an inexpensive medium. Glucose derived from maize starch hydrolysate was the sole carbon source and defatted soybean\\u000a meal and sodium nitrate were the nitrogen sources. Optimal arachidonic acid yield (1.47 g l-1) was observed at a glucose concentration of 100 g l-1. Various treatments of defatted soybean meal

M. Zhu; L.-J. Yu; Y.-X. Wu

2003-01-01

117

Ear asymmetries in middle-ear, cochlear, and brainstem responses in human infants  

PubMed Central

In 2004, Sininger and Cone-Wesson examined asymmetries in the signal-to-noise ratio (SNR) of otoacoustic emissions (OAE) in infants, reporting that distortion-product (DP)OAE SNR was larger in the left ear, whereas transient-evoked (TE)OAE SNR was larger in the right. They proposed that cochlear and brainstem asymmetries facilitate development of brain-hemispheric specialization for sound processing. Similarly, in 2006 Sininger and Cone-Wesson described ear asymmetries mainly favoring the right ear in infant auditory brainstem responses (ABRs). The present study analyzed 2640 infant responses to further explore these effects. Ear differences in OAE SNR, signal, and noise were evaluated separately and across frequencies (1.5, 2, 3, and 4 kHz), and ABR asymmetries were compared with cochlear asymmetries. Analyses of ear-canal reflectance and admittance showed that asymmetries in middle-ear functioning did not explain cochlear and brainstem asymmetries. Current results are consistent with earlier studies showing right-ear dominance for TEOAE and ABR. Noise levels were higher in the right ear for OAEs and ABRs, causing ear asymmetries in SNR to differ from those in signal level. No left-ear dominance for DPOAE signal was observed. These results do not support a theory that ear asymmetries in cochlear processing mimic hemispheric brain specialization for auditory processing. PMID:18345839

Keefe, Douglas H.; Gorga, Michael P.; Jesteadt, Walt; Smith, Lynette M.

2008-01-01

118

On the importance of plasmalogen status in stimulated arachidonic acid release in the macrophage cell line RAW 264.7.  

PubMed

We examined the dependence of stimulated arachidonic acid release on plasmalogens using the murine, macrophage cell line 264.7 and two plasmalogen-deficient variants, RAW.12 and RAW.108. All three strains responded to unopsinized zymosan to release arachidonic acid from phospholipid stores. Arachidonic acid release appeared to be dependent on calcium-independent phospholipase A(2) activation (iPLA(2)); bromoenol lactone, a specific inhibitor of calcium-independent iPLA(2), blocked arachidonic acid release with an IC(50) of approximately 2 x 10(-7)M. Propanolol, an inhibitor of phosphatidate phosphatase, and RHC-80267, an inhibitor of diglyceride lipase, had no effect on arachidonic acid release. Arachidonic acid release in the variants displayed similar magnitude, kinetics of response and sensitivity to the inhibitors when compared to the parent strain. Arachidonic acid was released from all major phospholipid head group classes with the exception of sphingomyelin. In wild-type cells, arachidonic acid released from the ethanolamine phospholipids was primarily from the plasmalogen form. However, in the plasmalogen-deficient cells release from the diacyl species, phosphatidylethanolamine, was increased to compensate. Restoration of plasmalogens by supplementation of the growth medium with the bypass compounds sn-1-hexadecylglycerol and sn-1-alkenylglycerol had no effect on arachidonic acid release. In summary, plasmalogen status appears to have no influence on the zymosan A stimulated release of arachidonic acid from the RAW 264.7 cell line. PMID:18328831

Gaposchkin, Daniel P; Farber, Harrison W; Zoeller, Raphael A

2008-04-01

119

Perspective methods of human identification: Ear biometrics  

NASA Astrophysics Data System (ADS)

Geometrical methods of feature extraction from ear images in order to perform human identification are presented. Geometrical approach is motivated by the actual procedures used by police and forensic experts (so-called ear otoscopy). In their work, geometrical features of ears such as size, height, width, and shapes of earlobe are useful and valid proofs of identity. The contribution of the article is development of the new and original methods of geometrical feature extraction from 2D ear images. Four novel algorithms of ear feature extraction from contour images are described in detail. Moreover, identification results obtained for each of the methods, based on the distance of feature vectors in the feature space, are presented.

Chora?, M.

2008-03-01

120

Gene therapy for the inner ear  

PubMed Central

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

Fukui, Hideto; Raphael, Yehoash

2012-01-01

121

Activation and regulation of arachidonic acid release in rabbit peritoneal neutrophils  

SciTech Connect

Arachidonic acid release in rabbit neutrophils can be enhanced by the addition of chemotactic fMet-Leu-Phe, platelet-activating factor, PAF, or the calcium ionophore A23187. Over 80% of the release ({sup 3}H)arachidonic acid comes from phosphatidylcholine and phosphatidylinositol. The release is dose-dependent and increases with increasing concentration of the stimulus. The A23187-induced release increases with increasing time of the stimulation. ({sup 3}H)arachidonic acid release, but not the rise in the concentration of intracellular calcium, is inhibited in pertussis toxin-treated neutrophils stimulated with PAF. The ({sup 3}H)arachidonic acid released by A23187 is potentiated while that release by fMET-Leu-Phe or PAF is inhibited in phorbol 12-myristate 13-acetate, PMA, treated rabbit neutrophils. The protein kinase C inhibitor 1-(5-isoquinoline sulfonyl)-2-methylpiperazine, H-7, has no effect on the potentiation by PMA of the A23187-induced release, it prevents the inhibition by PMA of the release produced by PAF or fMet-Leu-Phe. In addition, PMA increases arachidonic acid release in H-7-treated cells stimulated with fMet-Leu-Phe. The diacylglycerol kinase inhibitor R59022 increases the level of diacylglycerol in neutrophils stimulated with fMet-Leu-Phe. Furthermore, R59022 potentiates ({sup 3}H) arachidonic acid release produced by fMet-Leu-Phe. This potentiation is not inhibited by H-7, in fact, it is increased in H-7-treated neutrophils.

Tao, W.

1988-01-01

122

DOCOSAHEXAENOIC ACID AND ARACHIDONIC ACID PREVENT ESSENTIAL FATTY ACID DEFICIENCY AND HEPATIC STEATOSIS  

PubMed Central

Objectives Essential fatty acids are important for growth, development, and physiologic function. Alpha-linolenic acid and linoleic acid are the precursors of docosahexaenoic and arachidonic acid, respectively, and have traditionally been considered the essential fatty acids. However, we hypothesized that docosahexaenoic acid and arachidonic acid can function as the essential fatty acids. Methods Using a murine model of essential fatty acid deficiency and consequent hepatic steatosis, we provided mice with varying amounts of docosahexaenoic and arachidonic acids to determine whether exclusive supplementation of docosahexaenoic and arachidonic acids could prevent essential fatty acid deficiency and inhibit or attenuate hepatic steatosis. Results Mice supplemented with docosahexaenoic and arachidonic acids at 2.1% or 4.2% of their calories for 19 days had normal liver histology and no biochemical evidence of essential fatty acid deficiency, which persisted when observed after 9 weeks. Conclusion Supplementation of sufficient amounts of docosahexaenoic and arachidonic acids alone without alpha-linolenic and linoleic acids meets essential fatty acid requirements and prevents hepatic steatosis in a murine model. PMID:22038210

Le, Hau D.; Meisel, Jonathan A.; de Meijer, Vincent E.; Fallon, Erica M.; Gura, Kathleen M.; Nose, Vania; Bistrian, Bruce R.; Puder, Mark

2012-01-01

123

Bias-dependent amino-acid-induced conductance changes in short semi-metallic carbon nanotubes  

E-print Network

Bias-dependent amino-acid-induced conductance changes in short semi-metallic carbon nanotubes G-acid adsorption are bias-dependent. PACS number: 72.80.RJ Submitted to: Nanotechnology #12;Bias that is confirmed by calculations for armchair tubes that are not presented in this paper), or semiconducting tubes

Pulfrey, David L.

124

Abscisic Acid Induces Formation of Floating Leaves in the Heterophyllous Aquatic Angiosperm Potamogeton nodosus  

Microsoft Academic Search

Potamogeton nodosus tubers produce floating-type instead of submersed-type leaves when exposed to 10-5 molar synthetic abscisic acid. Abscisic acid-induced leaves have stomata on upper leaf surfaces and higher widthllength ratios than controls. These effects are wholly or partially overcome by simultaneous exposure to abscisic acid combined with gibberellic acid, kinetin, or benzyladenine.

Lars W. J. Anderson

1978-01-01

125

Abscisic Acid Induces Formation of Floating Leaves in the Heterophyllous Aquatic Angiosperm Potamogeton nodosus.  

PubMed

Potamogeton nodosus tubers produce floating-type instead of submersed-type leaves when exposed to 10(-5) molar synthetic abscisic acid. Abscisic acid-induced leaves have stomata on upper leaf surfaces and higher width/length ratios than controls. These effects are wholly or partially overcome by simultaneous exposure to abscisic acid combined with gibberellic acid, kinetin, or benzyladenine. PMID:17830317

Anderson, L W

1978-09-22

126

In Vitro Visualization and Quantication of Oleic Acid Induced Changes in Transdermal Transport Using  

E-print Network

of drug delivery, including oral and subcutaneous administration, transdermal drug de- livery offers the transdermal delivery of drugs such as scopolamine, clonidine, nitroglycerine, estradiol, fetanyl, and nicotineIn Vitro Visualization and Quanti®cation of Oleic Acid Induced Changes in Transdermal Transport

So, Peter

127

Tumor Cell-derived 12(S)-Hydroxyeicosatetraenoic Acid Induces Microvascular Endothelial Cell Retraction  

Microsoft Academic Search

Our previous work demonstrated that the 12-1ipoxygenase metabolite of arachidonic acid, 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE) in- duced a nondestructive and reversible retraction of cultured endothelial cells. In the current study we tested the hypothesis that tumor cells pro- duce 12(S)-HETE during their interactions with endothelial cells which in turn induces endothelial cell retraction. Coincubation of Lewis lung car- cinoma cells or

Kenneth V. Honn; Dean G. Tang; Irma Grossi; Zofia M. Duniec; Jozsef Timar; Colette Renaud; Marie Leithauser; Ian Blair; Carl R. Johnson; Clement A. Diglio; Victoria A. Kimler; John D. Taylor; Lawrence J. Marnett

128

Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.  

PubMed

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

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

2014-09-01

129

Arachidonic acid metabolism in heat-shock treated human leucocytes.  

PubMed Central

Human neutrophil granulocyte fractions (PMN) and lymphocytes/monocytes/basophils (LMB) were stimulated with A23187 (7.3 microM), opsonized zymosan (1 mg) or FMLP (10(-5) M) after heat-shock treatment. We observed a temperature- (pretreatment over 40 degrees) and time-dependent (incubation periods longer than 20 min) suppression in the generation of LTB4, LTB4 metabolites and isomers, as well as LTC4 and 5-HETE. These effects were not reversed after the addition of exogenous arachidonic acid (AA;50 microM). In contrast, heat-shock treatment alone triggered platelets to generate 12-HETE. After 1 hr at 42 degrees, 135 +/- 24 ng of 12-HETE were generated from 1 x 10(8) cells. The 12-HETE generation was not dependent on extracellular Ca2+. Conversion of 14C-AA (2 nmol) revealed an enhanced metabolism of AA to 12-HETE by platelets after heat-shock treatment without exogenous Ca2+. PMN and LMB labelled with 35S-methionine led to heat-shock protein (HSP; 65,000, 83,000 MW) expression after heat-shock treatment at 42 degrees or in the presence of NDGA (1 x 10(-5) M) at 37 degrees. These results suggest a regulatory interaction between the generation of lipo-oxygenase products, cellular stress responses and the expression of HSP. Images Figure 4 Figure 5 PMID:2118477

Koller, M; Konig, W

1990-01-01

130

Arachidonate lipoxygenases as essential regulators of cell survival and apoptosis.  

PubMed Central

Arachidonic acid (AA) metabolites derived from both cyclooxygenase (COX) and lipoxygenase (LOX) pathways transduce a variety of signals related to cell growth. Here, we report that the AA LOX pathway also functions as a critical regulator of cell survival and apoptosis. Rat Walker 256 (W256) carcinosarcoma cells express 12-LOX and synthesize 12(S)- and 15(S)-hydroxyeicosatetraenoic acids as their major LOX metabolites. W256 cells transfected with 12-LOX-specific antisense oligonucleotide or antisense oligonucleotides directed to conserved regions of LOXs underwent time- and dose-dependent apoptosis. Likewise, treatment of W256 cells with various LOX but not COX inhibitors induced apoptotic cell death, which could be partially inhibited by exogenous 12(S)- or 15(S)-hydroxyeicosatetraenoic acids. The W256 cell apoptosis induced by antisense oligos and LOX inhibitors was followed by a rapid downregulation of bcl-2 protein, a dramatic decrease in the bcl-2/bax ratio, and could be suppressed by bcl-2 overexpression. In contrast, p53, which is wild type in W256 cells, did not undergo alterations during apoptosis induction. The results suggest that the LOX pathway plays an important physiological role in regulating apoptosis. Images Fig. 1 Fig. 2 Fig. 4 PMID:8643560

Tang, D G; Chen, Y Q; Honn, K V

1996-01-01

131

Effects of middle-ear disorders on power reflectance measured in cadaveric ear canals  

PubMed Central

Objective Reflectance measured in the ear canal offers a noninvasive method to monitor the acoustic properties of the middle ear, and few systematic measurements exist on the effects of various middle-ear disorders on the reflectance. This work utilizes a human cadaver-ear preparation and a mathematical middle-ear model to both measure and predict how power reflectance ? is affected by the middle-ear disorders of static middle-ear pressures, middle-ear fluid, fixed stapes, disarticulated incudo-stapedial joint, and tympanic-membrane perforations. Design ? was calculated from ear-canal pressure measurements made on human-cadaver ears in the normal condition and five states: (1) positive and negative pressure in the middle-ear cavity, (2) fluid-filled middle ear, (3) stapes fixed with dental cement, (4) incudo-stapedial joint disarticulated, and (5) tympanic-membrane perforations. The middle-ear model of Kringlebotn (1988) was modified to represent the middle-ear disorders. Model predictions are compared to measurements. Results For a given disorder, the general trends of the measurements and model were similar. The changes from normal in ?, induced by the simulated disorder, generally depend on frequency and the extent of the disorder (except for the disarticulation). Systematic changes in middle-ear static pressure (up to ± 300 daPa) resulted in systematic increases in ?. These affects were most pronounced for frequencies up to 1000 to 2000 Hz. Above about 2000 Hz there were some asymmetries in behavior between negative and positive pressures. Results with fluid in the middle-ear air space were highly dependent on the percentage of the air space that was filled. Changes in ? were minimal when a smaller fraction of the air space was filled with fluid, and as the air space was filled with more saline, ? increased at most frequencies. Fixation of the stapes generally resulted in a relatively small low-frequency increase in ?. Disarticulation of the incus with the stapes led to a consistent low-frequency decreases in ? with a distinctive minimum below 1000 Hz. Perforations of the tympanic membrane resulted in a decrease in ? for frequencies up to about 2000 Hz; at these lower frequencies, smaller perforations led to larger changes from normal as compared to larger perforations. Conclusions These preliminary measurements help assess the utility of power reflectance as a diagnostic tool for middle-ear disorders. In particular, the measurements document (1) the frequency ranges for which the changes are largest and (2) the extent of the changes from normal for a spectrum of middle-ear disorders. PMID:22037477

Merchant, Gabrielle R.; Horton, Nicholas J.

2011-01-01

132

Human antimicrobial proteins in ear wax.  

PubMed

The external auditory canal is vulnerable to bacterial infections, but little is known about thechemical compositions of ear wax regarding antimicrobial peptides. We, therefore, studied the proteinconcentrations of ten well-known human antimicrobial peptides from ear wax.Twenty ear wax samples from healthy individuals were analysed using enzyme-linked immunosorbent assay (ELISA) to determine theprotein concentrations of the antimicrobial peptides hBD1-3, lactoferrin, LL-37, BPI, hSLPI and HNP1-3. All ten antimicrobial peptides are present in ear wax. Some of these proteins seem to be merelycell-bound in ear wax. Antimicrobial peptides in ear wax prevent bacteria and fungi from causing infections inthe external auditory canal. The role and importance of these proteins for the blind-ending ear externalcanal is discussed. If this local defence system fails, infections of the external auditory canal may result.The knowledge about the presence of antimicrobial peptides in cerumen may lead to new concepts ofthe local treatment of external auditory canal diseases in the future. PMID:21298458

Schwaab, M; Gurr, A; Neumann, A; Dazert, S; Minovi, A

2011-08-01

133

Production of high yields of arachidonic acid in a fed-batch system by Mortierella alpina ATCC 32222  

Microsoft Academic Search

Of six strains of Mortierella tested, Mortierella alpina ATCC 32222 produced the highest yields of arachidonic acid. Supplementation of soy flour (1% w\\/v) and vegetable oils (1%\\u000a v\\/v) significantly increased the biomass, lipid content and arachidonic acid level. Replacement of NaNO3 with corn steep liquor (1% w\\/v) also improved arachidonic acid production. A fed-batch culture system at 25?°C, producing\\u000a a

A. Singh; O. P. Ward

1997-01-01

134

Middle-ear dynamics before and after ossicular replacement  

Microsoft Academic Search

The mechanism of hearing involves conduction of mechanical vibrations along the ossicular chain to the inner ear. An acoustic wave is collected and transformed as it passes down the ear canal and impacts on the tympanic membrane (ear drum). The drum is connected to the inner-ear by three ossicle bones (malleus, incus, and stapes) in a complex arrangement, which serves

P. Ferris; P. J. Prendergast

2000-01-01

135

Middle-ear dynamics before and after ossicular replacementq  

Microsoft Academic Search

The mechanism of hearing involves conduction of mechanical vibrations along the ossicular chain to the inner ear. An acoustic wave is collected and transformed as it passes down the ear canal and impacts on the tympanic membrane (ear drum). The drum is connected to the inner-ear by three ossicle bones (malleus, incus, and stapes) in a complex arrangement, which serves

P. Ferris; P. J. Prendergast

2000-01-01

136

Ear Infections in Autistic and Normal Children. Brief Report.  

ERIC Educational Resources Information Center

Evaluation of the frequency of ear infections, ear tube drainage, and deafness for 51 autistic children (ages 2-18) indicated that autistic children had a greater incidence of ear infections than matched normal peers and lower functioning children had an earlier onset of ear infections than higher functioning autistic peers. (Author)

Konstantareas, M. Mary; Homatidis, Soula

1987-01-01

137

A new analytical theory for earing generated from anisotropic plasticity  

Microsoft Academic Search

Commercial canmaking processes include drawing, redrawing and several ironing operations. It is experimentally observed that during the drawing and redrawing processes earing develops, but during the ironing processes earing is reduced. It is essential to understand the earing mechanism during drawing and ironing for an advanced material modeling. A new analytical approach that relates the earing profile to r-value and

J. W. Yoon; R. E. Dick; F. Barlat

2011-01-01

138

Arachidonic acid metabolism in silica-stimulated bovine alveolar macrophages  

SciTech Connect

The in vitro production of arachidonic acid (AA) metabolites in adherent bovine alveolar macrophages (BAM) incubated with silica was investigated. BAM were pre-labelled with {sup 3}H-AA, and lipid metabolites released into the culture medium were analyzed by high performance liquid chromatography (HPLC). Lactate dehydrogenase (LDH) release was simultaneously assayed to provide an indication of cell injury. Increasing doses of silica selectively stimulated the 5-lipoxygenase pathway of AA metabolism, while cyclooxygenase metabolite output was suppressed. LDH release increased in a linear, dose-dependent fashion over the range of silica doses used. Moreover, within 15 min following addition of a high silica dose, a shift to the production of 5-lipoxygenase metabolites occurred, accompanied by a reduction in cyclooxygenase products. This rapid alteration in AA metabolism preceded cell injury. To examine the relationship between cytotoxicity and AA metabolite release by BAM exposed to silicas with different cytotoxic and fibrogenic activities, BAM were exposed to different doses of DQ-12, Minusil-5, and Sigma silicas, and carbonyl iron beads. The median effective dose (ED{sub 50}) of each particulate to stimulate the release of AA metabolites and LDH was calculated. The ED{sub 50} values for DQ-12, Minusil-5, and Sigma silica showed that the relative cytotoxicities of the different silicas for BAM corresponded to the relative potencies of the silicas to elicit 5-lipoxygenase metabolites from BAM. These results indicate that the cytotoxic, and presumed fibrogenic potential, of a silica is correlated with the potency to stimulate the release of leukotrienes from AM.

Englen, M.D.

1989-01-01

139

Tympanosclerosis of the ear drum in children.  

PubMed

Tympanosclerosis of the ear drum in children is associated with secretory otitis media. The tympanosclerotic changes affect the pars tensa and seem to be a dynamic process of new formation together with regress and restoration to normal tissue. Our study includes 90 cleft palate children followed for 7.8 years with a total of 2068 examinations. During the observation period 59% of the ear drums were affected by tympanosclerosis, while only 42% had tympanosclerosis at the last examination. The tympanosclerotic lesion of the ear drum disappeared completely in 30%, seemed stable in 40% and tended to grow steadily in 30% of the ear drums affected. The pathogenesis of tympanosclerosis is not clear, although the inflammation known to exist in secretory otitis media probably plays an important part. PMID:6541211

Møller, P

1984-07-01

140

Mozart ear: diagnosis, treatment, and literature review.  

PubMed

Mozart ear is a congenital auricular deformity, which is mainly characterized by a bulging appearance of the anterosuperior portion of the auricle, a convexly protruded cavum conchae, and a slit-like narrowing of the orifice of the external auditory meatus. It is said to be uncommon, and because no one has yet fully described neither the disease nor the treatment, the concept of Mozart ear has not been unified. This report describes a case of a 13-year-old girl presented with an unusual congenital deformity which showed the features of Mozart ear. It is an extremely rare deformity that only about 4 clinical cases have been reported in medical literature thereby a treatment method has not been fully discussed. For surgical correction of our cases, we excised deformed conchal cartilage, turned it over, regrafted, and maintained a cosmetically positive result. We also reviewed and described the origin, current concept, and treatment method of Mozart ear. PMID:21587051

Yamashita, Ken; Yotsuyanagi, Takatoshi; Saito, Tamotsu; Isogai, Noritaka; Mori, Hiromasa; Itani, Yoshihito

2011-11-01

141

Animal communication: flies' ears are tuned in.  

PubMed

Male fruit flies sing to females with quiet, close-range wing vibrations. A new study has found that the flies' antennal ears show active tuning to the species-specific frequencies of songs. PMID:21514508

Immonen, Elina; Ritchie, Michael G

2011-04-26

142

Middle Ear Surgery in Only Hearing Ears and Postoperative Hearing Rehabilitation  

PubMed Central

Background and Objectives The aim of this study was to evaluate surgical interventions and hearing rehabilitation in patients with chronic middle ear disease of only hearing ears. Subjects and Methods Thirty-one patients with chronic middle ear disease of only hearing ears were enrolled in this retrospective study. Patients were classified into three groups according to the hearing level: groups A [pure tone audiometry (PTA)<40], B (40?PTA<70), and C (PTA?70). We evaluated hearing results and patterns of auditory rehabilitation. Results The main consideration for a surgical procedure was the presence of recurrent otorrhea and structural destruction. The reasons for surgical intervention in only hearing ears were otorrhea caused by chronic otitis media (68%), cholesteatoma (29%), and cholesterol granuloma (3%). The causes of contralateral deaf ears were chronic otitis media (81%) and sensorineural hearing loss (19%). Although there was hearing deterioration in some patients with severe hearing loss (PTA?70), all patients achieved dry ears after surgery and functional hearing using auditory rehabilitation. Hearing aids were used in most patients with moderate to moderately severe hearing loss and cochlear implants were used for auditory rehabilitation in patients with severe to profound hearing loss. Conclusions Proper evaluation and indications for surgery in only hearing ears are important for successful eradication of inflammation and hearing preservation. Surgical interventions can achieve dry ear and enable further auditory rehabilitations using hearing aids and cochlear implantation. PMID:25279226

Yoo, Myung Hoon; Kang, Byung Chul; Park, Hong Ju

2014-01-01

143

Correcting for ear canal collapse during audiometry.  

PubMed

The hearing thresholds of 20 subjects with normal hearing and normal ear canals and two subjects with collapsible ear canals were measured at octave frequencies from 250 to 8000 Hz under standard transducers (TDH-39) fitted with standard cushions (MX-41/AR) and experimental cushions (Telephonics 266CIII). When correction factors based on normal threshold differences were applied, thresholds obtained under the experimental cushion reasonably approximated the actual hearing of individuals with collapsible canals. PMID:6628851

Rizzo, S R

1983-01-01

144

Sphingosine 1-phosphate induces arachidonic acid mobilization in A549 human lung adenocarcinoma cells.  

PubMed

In the present paper, the effect of sphingosine 1-phosphate (Sph-1-P) on arachidonic acid mobilization in A549 human lung adenocarcinoma cells was investigated. Sph-1-P provoked a rapid and relevant release of arachidonic acid which was similar to that elicited by bradykinin, well-known pro-inflammatory agonist. The Sph-1-P-induced release of arachidonic acid involved Ca(2+)-independent phospholipase A(2) (iPLA2) activity, as suggested by the dose-dependent inhibition exerted by the rather specific inhibitor bromoenol lactone. The Sph-1-P-induced release of arachidonic acid was pertussis toxin-sensitive, pointing at a receptor-mediated mechanism, which involves heterotrimeric Gi proteins. The action of Sph-1-P was totally dependent on protein kinase C (PKC) catalytic activity and seemed to involve agonist-stimulated phospholipase D (PLD) activity. This study represents the first evidence for Sph-1-P-induced release of arachidonic acid which occurs through a specific signaling pathway involving Gi protein-coupled receptor(s), PKC, PLD and iPLA2 activities. PMID:10601704

Vasta, V; Meacci, E; Catarzi, S; Donati, C; Farnararo, M; Bruni, P

2000-01-01

145

Effects of sodium bicarbonate on butyric acid-induced epithelial cell damage in vitro.  

PubMed

Butyric acid is detected in periodontal pockets and is thought to be involved in the initiation and progression of periodontal disease. We examined the effects of sodium bicarbonate on the butyric acid-induced epithelial cell damage. The human gingival carcinoma cell line Ca9-22 was cultured in medium that contained butyric acid with or without sodium bicarbonate. The viability of cells treated with sodium bicarbonate was significantly higher than that of cells treated with butyric acid alone. The effects of butyric acid on ICAM-1 expression were significantly improved by sodium bicarbonate. Within the limitations of this in vitro study, sodium bicarbonate was indicated to be a useful therapeutic agent to reduce the butyric acid-induced periodontal tissue damage. PMID:19106468

Takigawa, Satoko; Sugano, Naoyuki; Ochiai, Kuniyasu; Arai, Noriyuki; Ota, Noriko; Ito, Koichi

2008-12-01

146

Dermatologic diseases of the external ear.  

PubMed

The external ear is composed of the auricle (pinna) and the external auditory canal. Both of these structures contain elastic cartilage (except the earlobe) and a small amount of subcutaneous fat, which are covered by skin. The skin of the cartilaginous canal contains hair cells, sebaceous (lipid-producing) glands, and apocrine (ceruminous) glands; this is in contrast with the osseous canal, which contains neither glands nor hair follicles. The auricle is susceptible to environmental influences and trauma. Due to its exposed locale, the ear is particularly vulnerable to the effects of ultraviolet light and, consequently, to preneoplastic and neoplastic skin lesions. The ear also has a sound-receiving function and a location that is both visible and aesthetically obvious, thereby drawing considerable attention from the patient. Dermatologic diseases on the external ear are seen in a variety of medical disciplines. Dermatologists, otorhinolaryngologists, family practitioners, and general and plastic surgeons are regularly consulted about cutaneous lesions on the ear. These lesions can be grouped into three main categories: (1) infectious; (2) tumoral; and (3) noninfectious inflammatory. The purposes of this contribution are to review various dermatologic diseases of the external ear and to update current diagnosis and treatment information related to these conditions. PMID:24314388

Oztürkcan, Sedat; Oztürkcan, Serap

2014-01-01

147

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

Microsoft Academic Search

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

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

2009-01-01

148

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

SciTech Connect

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.

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

1986-02-01

149

The stimulation of arachidonic acid metabolism in human platelets by hydrodynamic stresses  

NASA Technical Reports Server (NTRS)

The effects of stimulating human platelets by thrombin and by hydrodynamic stresses on the platelets' arachidonic acid metabolism were investigated using (1-C-14)-arachidonic acid label and a specially designed viscometer that ensured laminar shear flow with a nearly uniform shear rate throughout the flow region. It was found that platelets activated by thrombin formed principally thromboxane A2, 12-hydroxy 5,8,10-heptadecatrienoic acid and 12-hydroxy 5,8,10,14-eicosatetraenoic acid (12-HETE). On the other hand, platelets activated by shear, formed only 12-HETE (although arachidonic acid metabolism was stimulated); no cyclooxygenase metabolites were detected. Results indicate that platelets may greatly increase their 12-HETE production when activated by passage through a high-stress region of the circulation, such as an atherosclerotic stenosis.

Rajagopalan, Sridhar; Mcintire, Larry V.; Hall, Elizabeth R.; Wu, Kenneth K.

1988-01-01

150

Evidence for, and taxonomic value of, an arachidonic acid cascade in the Lipomycetaceae.  

PubMed

By using specific inhibitors of the lipoxygenase and cyclo-oxygenase pathways, arachidonic acid metabolites with similar sensitivities towards these inhibitors as in humans, were detected in Dipodascopsis uninucleata. The taxonomic value of aspirin sensitive arachidonic acid metabolites in the Lipomycetaceae was next assessed. No metabolites of which the production is inhibited by aspirin were detected in strains representing the following species: Lipomyces starkeyi, Lipomyces kononenkoae, Lipomyces tetrasporus, Myxozyma melibiosi, Myxozyma mucilagina, Myxozyma kluyveri, Waltomyces lipofer, Zygozyma oligophaga and Zygozyma arxii. The detection of such aspirin sensitive arachidonic acid metabolites in representative strains of Lipomyces anomalus and the genus Dipodascopsis, emphasises the isolated position of these taxa in the genus Lipomyces and the family Lipomycetaceae, respectively. Finally using long chain fatty acid analyses, electrophoretic karyotyping and other phenotypic characters, a phylogenetic scheme is proposed for some genera in the Lipomycetaceae. PMID:1285641

Kock, J L; Coetzee, D J; van Dyk, M S; Truscott, M; Botha, A; Augustyn, O P

1992-11-01

151

[Effect of methyljasmononate on induction of late-blight resistance of potatoes using arachidonic acid].  

PubMed

Methyl ester of jasmonic acid (Me-JA) influences the induced resistance of potato tubers to late blight caused by Phytophthora infestans. Treatment of potato tuber disk surface with Me-JA solution or exposure to an atmosphere containing Me-JA vapors (10(-6)-10(-5) M) increased the rate of rishitin biosynthesis induced by arachidonic acid or P. infestans. Methyl jasmonate increased the sensitivity of potato tissue to arachidonic acid. As a result, in the presence of Me-JA, the protective properties of arachidonic acid were observed at lower concentrations than in the absence of Me-JA. In addition, Me-JA reduced the adverse effects of lipoxygenase inhibitors (salicylhydroxamic acid and esculetin) on the induced resistance of potato tubers to late blight. Therefore, the synergistic interaction of Me-JA and biogenic elicitors can be regarded as part of a mechanism of potato defense against diseases. PMID:10780012

Il'inskaia, L I; Chalenko, G I; Perekhod, E A; Gerasimova, N G; Ozeretskovskaia, O L

2000-01-01

152

Changes in arachidonic acid metabolism in UV-irradiated hairless mouse skin  

SciTech Connect

This study was conducted to investigate the metabolism of arachidonic acid in the skin of hairless mice exposed to UVA, PUVA, UVB, and UVC irradiation. The main products of arachidonic acid in the epidermis were hydroxyeicosatetraenoic acid (HETE), PGE2, and PGD2. Dermis displayed a lower lipoxygenase activity (expressed as HETE production) than the epidermis and showed no detectable cyclooxygenase activity, i.e., no prostaglandin production. The main changes observed in UV-induced inflammatory reactions were as follows. 1. A 5-fold increase in dermal HETE production in PUVA-treated animals and a 29% reduction in epidermal HETE formation after UVC treatment. 2. A marked decrease of PGD2 and a marked increase of PGE2 formation due to alterations of PGH2 metabolism in the UVB-treated group; however, cyclooxygenase activity was unchanged. These changes in arachidonic acid metabolism in the skin may be of pathophysiologic importance in UV-induced inflammatory reaction.

Ruzicka, T.; Walter, J.F.; Printz, M.P.

1983-10-01

153

An evaluation of tympanometric estimates of ear canal volume.  

PubMed

The accuracy of tympanometric estimates of ear canal volume was evaluated by testing the following two assumptions on which the procedure is based: (a) ear canal volume does not change when ear canal pressure is varied, and (b) an ear canal pressure of 200 daPa drives the impedance of the middle ear transmission system to infinity so the immittance measured at 200 daPa can be attributed to the ear canal volume alone. The first assumption was tested by measuring the changes in ear canal volume in eight normal subjects for ear canal pressures between +/- 400 daPa using a manometric procedure based on Boyle's gas law. The data did not support the first assumption. Ear canal volume changed by a mean of .113 ml over the +/- 400 daPa pressure range with slightly larger volume changes occurring for negative ear canal pressures than for positive ear canal pressures. Most of the volume change was attributed to movement of the probe and to movement of the cartilaginous walls of the ear canal. The second assumption was tested by comparing estimates of ear canal volume from susceptance tympanograms with a direct measurement of ear canal volume adjusted for changes in volume due to changes in ear canal pressure between +/- 400 daPa. These data failed to support the second assumption. All tympanometric estimates of ear canal volume were larger than the measured volumes. The largest error (39%) occurred for an ear canal pressure of 200 daPa at 220 Hz, whereas the smallest error (10%) occurred for an ear canal pressure of -400 daPa at 660 Hz. This latter susceptance value (-400 daPa at 660 Hz) divided by three is suggested to correct the 220-Hz tympanogram to the plane of the tympanic membrane. Finally, the effects of errors in estimating ear canal volume on static immittance and on tympanometry are discussed. PMID:7329051

Shanks, J E; Lilly, D J

1981-12-01

154

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

E-print Network

An Eye for an Ear and an Ear for an Eye: Bidirectional Control in Virtual Multimedia Instrument Design Christian Jacquemin LIMSI-CNRS and University Paris 11, BP 133, 91403 ORSAY, France Abstract is illustrated on two examples of systems that use bidirectional control, autonomous mapping and a high degree

Jacquemin, Christian

155

Ex vivo effects of nonsteroidal antiinflammatory drugs on arachidonic acid metabolism in neutrophils from a reverse passive Arthus reaction  

Microsoft Academic Search

Rat neutrophils isolated from 4-h reverse passive Arthus reaction (RPAR) pleural exudates actively metabolize arachidonic acid via cyclooxygenase and lipoxygenase. Utilizing this system, the effect of oral doses of nonsteroidal antiinflammatory drugs on the ability of these cells to produce HHT, 5-HETE, and LTB from exogenously added arachidonic acid has been investigated. In vitro and ex vivo, indomethacin and timegadine

Robin F. Myers; John C. Anthes; Charles J. Casmer; Marvin I. Siegel

1985-01-01

156

Arachidonic acid activation of a new family of K+ channels in cultured rat neuronal cells.  

PubMed Central

1. The presence and properties of K+ channels activated by arachidonic acid were studied in neuronal cells cultured from the mesencephalic and hypothalamic areas of rat brain. 2. Arachidonic acid produced a concentration-dependent (5-50 microM) and reversible activation of whole-cell currents. 3. In excised membrane patches, arachidonic acid applied to the cytoplasmic or extracellular side of the membrane caused opening of three types of channels whose current-voltage relationships were slightly outwardly rectifying, inwardly rectifying and linear, and whose single channel slope conductances at +60 mV were 143, 45 and 52 pS, respectively. 4. All three currents were K+ selective and blocked by 2 mM Ba2+ but not by other K+ channel blockers such as tetraethylammonium chloride, 4-aminopyridine and quinidine. The outwardly and inwardly rectifying currents were slightly voltage dependent with higher channel activity at more depolarized potentials. 5. Arachidonic acid activated the K+ channels in cells treated with cyclo-oxygenase and lipoxygenase inhibitors (indomethacin and nordihydroguaiaretic acid), indicating that arachidonic acid itself can directly activate the channels. Alcohol and methyl ester derivatives of arachidonic acid failed to activate the K+ channels, indicating that the charged carboxyl group is important for activation. 6. Certain unsaturated fatty acids (linoleic, linolenic and docosahexaenoic acids), but not saturated fatty acids (myristic, palmitic, stearic acids), also reversibly activated all three types of K+ channel. 7. All three K+ channels were activated by pressure applied to the membrane (i.e. channels were stretch sensitive) with a half-maximal pressure of approximately 18 mmHg. The K+ channels were not blocked by 100 microM GdCl3. 8. A decrease in intracellular pH (over the range 5.6-7.2) caused a reversible, pH-dependent increase in channel activity whether the channel was initially activated by arachidonic acid or stretch. 9. Glutamate, a neurotransmitter reported to generate arachidonic acid in striatal neurons, did not cause activation of the K+ channels when applied extracellularly in cell-attached patches. 10. It is suggested that the K+ channels described here belong to a distinct family of ion channels that are activated by either fatty acids or membrane stretch. Although the physiological roles of these K+ channels are not yet known, they may be involved in cellular processes such as cell volume regulation and ischaemia-induced elevation of K+ loss. Images Figure 1 PMID:7623282

Kim, D; Sladek, C D; Aguado-Velasco, C; Mathiasen, J R

1995-01-01

157

The dependence of human T-lymphocyte migration on the 5-lipoxygenation of endogenous arachidonic acid  

Microsoft Academic Search

Human T lymphocytes in modified Boyden migration chambers exhibited a chemokinetic response, but no detectable chemotaxis, to 5(S),12(R)-dihydroxyeicosa-6, 14-cis-8,10-trans-tetraenoic acid (leukotriene B4) and to 5(S)-hydroxyeicosatetraenoic acid (5-HETE), which are 5-lipoxygenase products of arachidonic acid, and failed to respond to either leukotriene C4 or 11-HETE. Concentrations of lymphocyte-derived 15-HETE and of 15-hydroperoxyeicosatetraenoic acid that inhibited the 5-lipoxygenation of endogenous arachidonic acid

Donald G. Payan; Edward J. Goetzl

1981-01-01

158

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...

159

Ear acupuncture in European traditional medicine.  

PubMed

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

Gori, Luigi; Firenzuoli, Fabio

2007-09-01

160

Assessment of Ear Disorders Using Power Reflectance  

PubMed Central

This paper describes the effect of various pathologies on power reflectance (PR) and absorbance measured in human adults. The pathologies studied include those affecting the tympanic membrane, the middle-ear ossicles, the middle-ear cavity, the inner ear, and intracranial pressure. Interesting pathology-induced changes in PR that are statistically significant have been reported. Nevertheless, because measurements of PR obtained from normal-hearing subjects have large variations and some pathology-induced changes are small, it can be difficult to use PR alone for differential diagnosis. There are, however, common clinical situations without reliable diagnostic methods that can benefit from PR measurements. These conditions include ears with a normal-appearing tympanic membrane, aerated middle-ear cavity and unknown etiology of conductive hearing loss. PR measurements in conjunction with audiometric measurements of air-bone gap have promise in differentiating among stapes fixation, ossicular discontinuity and superior semicircular canal dehiscence. Another possible application is to monitor an individual for possible changes in intracranial pressure. Descriptions of mechanisms affecting PR change and utilization of PR measurements in clinical scenarios are presented. PMID:23900180

Nakajima, Hideko Heidi; Rosowski, John J.; Shahnaz, Navid; Voss, Susan E.

2013-01-01

161

Evolution and development of the vertebrate ear  

NASA Technical Reports Server (NTRS)

This review outlines major aspects of development and evolution of the ear, specifically addressing issues of cell fate commitment and the emerging molecular governance of these decisions. Available data support the notion of homology of subsets of mechanosensors across phyla (proprioreceptive mechanosensory neurons in insects, hair cells in vertebrates). It is argued that this conservation is primarily related to the specific transducing environment needed to achieve mechanosensation. Achieving this requires highly conserved transcription factors that regulate the expression of the relevant structural genes for mechanosensory transduction. While conserved at the level of some cell fate assignment genes (atonal and its mammalian homologue), the ear has also radically reorganized its development by implementing genes used for cell fate assignment in other parts of the developing nervous systems (e.g., neurogenin 1) and by evolving novel sets of genes specifically associated with the novel formation of sensory neurons that contact hair cells (neurotrophins and their receptors). Numerous genes have been identified that regulate morphogenesis, but there is only one common feature that emerges at the moment: the ear appears to have co-opted genes from a large variety of other parts of the developing body (forebrain, limbs, kidneys) and establishes, in combination with existing transcription factors, an environment in which those genes govern novel, ear-related morphogenetic aspects. The ear thus represents a unique mix of highly conserved developmental elements combined with co-opted and newly evolved developmental elements.

Fritzsch, B.; Beisel, K. W.

2001-01-01

162

Mechanism of 12-O-tetradecanoylphorbol-13-acetate enhanced metabolism of arachidonic acid in dog urothelial cells.  

PubMed

The mechanism of 12-O-tetradecanoylphorbol-13-acetate (TPA) enhanced arachidonic acid metabolism was investigated in dog urothelial cells. Primary cultures of dog urothelial cells were grown to confluency and evaluated in the presence or absence of overnight prelabeling with [3H]arachidonic acid. High-performance liquid chromatography analysis of media from TPA stimulated cells indicated that prostaglandin E2 (PGE2) was the major eicosanoid produced. Lipoxygenase products were not detected. Control cell media contained only arachidonic acid. Effects of selected inhibitors on TPA and exogenous arachidonic acid mediated increases in radioimmunoassayable PGE2 were assessed. Prostaglandin H synthase inhibitors (indomethacin and aspirin) prevented both TPA and arachidonic acid increases in PGE2. By contrast, inhibitors of phospholipases (quinacrine, W-7, and trifluoropromazine), protein synthesis (cycloheximide), and protein kinase C (staurosporine) prevented TPA but not arachidonic acid increases in PGE2. The latter agents also reduced TPA mediated increases in the release of total radioactivity from cells labeled with [3H]arachidonic acid. However, aspirin reduced the amount of 3H-prostaglandins formed with TPA. A calcium requirement was demonstrated when increases in radioimmunoassayable PGE2 elicited by TPA and the calcium ionophore A23187 were reduced with calcium depleted media. When epidermal growth factor in combination with either TPA or bradykinin was used, at least additive effects were observed with respect to release of [3H]arachidonic acid, 3H-prostaglandins, and radioimmunoassayable PGE2. These experiments suggest that separate pathways may be involved in enhanced arachidonic acid metabolism demonstrated with different agonists. For TPA, increased arachidonic acid release occurs by a calcium dependent process involving phospholipase(s), protein synthesis, and protein kinase C. PMID:2114944

Zenser, T V; Eling, T E; Duniec, Z M; Wong, Y H; Davis, B B

1990-08-01

163

Opium addiction and cauliflower ears: a case report.  

PubMed

The case of an elderly Chinese male opium addict with cauliflower ears is discussed. He had no history of contact sports that could have led to auricular trauma resulting in deformed ears. Besides cauliflower ears, he had features of chronic bronchitis. The association between opium addiction and cauliflower ears was first described way back in 1932. It was attributed to the prolonged opium induced sleep on hard surface subjecting the ears to repeated pressure and trauma. With the changing pattern of drug abuse, opium abuse related cauliflower ears will become a vanishing sign. PMID:2017717

Muthusamy, E

1991-02-01

164

Correlation between morbid adenoid and atelectatic ear.  

PubMed

We observed the nasopharynx of 30 patients with atelectatic ears (AE), and 10 with healthy ear drums and mouth breathing by CT scan, to examine the relation between adenoid and otitis media. The adenoids of those with healthy ear drums were of the large posterior type with free space in the pharyngeal fossa, while those with AE were of the large anterior type in 18 patients and of the pendulous projection type over the choana in the other 12. The anatomical location of the adenoids should be considered when one discusses the relation between the adenoid and otitis media. The "Toynbee phenomenon", in the pendulous projection type and in the large anterior type of adenoid, was considered to be one of the etiological factors in AE. To understand the etiology of otitis media, it seems important to investigate the reason why the anterior projection of the adenoids occurs. PMID:3478943

Kowata, I; Awataguchi, T

1987-01-01

165

Precise individualized armature for ear reconstruction  

NASA Astrophysics Data System (ADS)

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.

Evenhouse, Raymond J.; Chen, Xiaoming

1991-04-01

166

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

Microsoft Academic Search

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

Anna Haug; Ingrid Olesen; Olav A Christophersen

2010-01-01

167

Safety evaluation of arachidonic acid rich Mortierella alpina biomass in albino rats—A subchronic study  

Microsoft Academic Search

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,

A. Nisha; S. P. Muthukumar; G. Venkateswaran

2009-01-01

168

Arachidonic acid metabolism as a reporter of skin irritancy and target of cancer chemoprevention  

Microsoft Academic Search

Keratinocytes respond to skin irritation and injury by cytokine release and a rapid but transient activation of arachidonic acid metabolism along both the cyclooxygenase and lipoxygenase pathways. In the first part of this article results are reviewed indicating that the release of pro-inflammatory mediators such as eicosanoids and interleukin-1 from keratinocytes provides a suitable in vitro parameter of irritancy. Based

F. Marks; G. Fürstenberger; K. Müller-Decker

1998-01-01

169

Equine tracheal epithelial membrane strips - An alternate method for examining epithelial cell arachidonic acid metabolism  

Microsoft Academic Search

Arachidonic acid metabolism by tracheal epithelium can be studied using enzymatically dispersed cell suspensions or cell cultures. Both techniques require considerable tissue disruption and manipulation and may not accurately represent in vivo activity. The authors have developed an alternate method for obtaining strips of equine tracheal epithelium without enzymatic digestion. In the horse, a prominent elastic lamina supports the tracheal

P. R. Gray; F. J. Derksen; N. E. Robinson; M. L. Peter-Golden

1990-01-01

170

Inhibition by arachidonic acid and other fatty acids of dopamine uptake at the human dopamine transporter  

Microsoft Academic Search

It is known that arachidonic acid, in addition to promoting release of dopamine, can inhibit its transport. The present study provides preliminary information on structure–activity relationships for uptake inhibition by rotating disk voltammetry in human embryonic kidney-293 cells expressing the human dopamine transporter. Except for anandamide, all other fatty acids studied at a pretreatment concentration of 80 ?M caused significant

Nianhang Chen; Michael Appell; Janet L. Berfield; Maarten E. A. Reith

2003-01-01

171

Extraction of lipids from Mortierella alpina and enrichment of arachidonic acid from the fungal lipids  

Microsoft Academic Search

Mortierella alpina is known as an arachidonic acid (AA) producing oleaginous fungus. Extraction of lipids from wet and dry M. alpina biomass was compared. Lipids yield of extraction from dry cells was higher than that of extraction from wet. Wet extraction mainly extracted lipid bodies and lipids in membranes did not extract effectively. Enrichment of AA from the fungal lipids

M. Zhu; P. P. Zhou; L. J. Yu

2002-01-01

172

Effect of nitrogen source on mycelial morphology and arachidonic acid production in cultures of mortierella alpina  

Microsoft Academic Search

The effects of nitrogen source on arachidonic acid (AA) production and morphological changes during the culture of Mortierella alpina were investigated using an image analysis system. When yeast extract, gluten meal, or corn steep liquor was used, a circular pellet morphology was obtained. However, when Pharmamedia, fish meal, or soybean meal was used, M. alpina formed radial filamentous mycelia. The

Enoch Y. Park; Yasuhisa Koike; Kenichi Higashiyama; Shigeaki Fujikawa; Mitsuyasu Okabe

1999-01-01

173

On the safety of Mortierella alpina for the production of food ingredients, such as arachidonic acid  

Microsoft Academic Search

Mortierella alpina is the most efficient production organism for arachidonic acid (AA) presently known. Since AA is being developed as a food ingredient, and since M. alpina has no history of use for such applications, we have undertaken this safety evaluation. M. alpina is a common soil fungus, to which humans are frequently exposed. The production strains are non-pathogenic and

Hugo Streekstra

1997-01-01

174

Growth-Coupled Lipid Synthesis in Mortierella alpina LPM 301, a Producer of Arachidonic Acid  

Microsoft Academic Search

Mortierella alpina LPM 301, a producer of arachidonic acid (ARA), was found to possess a unique property of intense lipid synthesis in the period of active mycelium growth. Under batch cultivation of this strain in glucose-containing media with potassium nitrate or urea, the bulk of lipids (28–35% of dry biomass) was produced at the end of the exponential growth phase

V. K. Eroshin; E. G. Dedyukhina; A. D. Satroutdinov; T. I. Chistyakova

2002-01-01

175

Red Algae of Peter the Great Bay as a Source of Arachidonic and Eicosapentaenoic Acids  

Microsoft Academic Search

In order to find new sources of arachidonic (AA) and eicosapentaenoic (EPA) acids, the composition of fatty acids was studied and lipid concentrations were determined in the thalluses of 32 species of red algae from Peter the Great Bay, Sea of Japan. The greatest level of EPA and a small concentration of AA were registered in the thalluses of Corallina

S. V. Khotimchenko; I. S. Gusarova

2004-01-01

176

Middle ear cholesteatoma in 11 dogs  

PubMed Central

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

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

2011-01-01

177

STAT pathway in the regulation of zoledronic acid-induced apoptosis in chronic myeloid leukemia cells.  

PubMed

In this study, we aimed to evaluate the cytotoxic and apoptotic effects of zoledronic acid on K562 chronic myeloid leukemia (CML) cells and to examine the roles of STAT genes on zoledronic acid-induced apoptosis. The results showed that zoledronic acid decreased proliferation, and induced apoptosis in K562 cells in a dose- and time-dependent manner. mRNA and protein levels of STAT3, -5A and -5B genes were significantly reduced in zoledronic acid-treated K562 cells. These data indicated that STAT inhibition by zoledronic acid may be therapeutic in CML patients following the confirmation with clinical studies. PMID:23725755

Kiper, Hatice Demet; Tezcanli Kaymaz, Burcin; Gokbulut, Aysun Adan; Selvi, Nur; Avci, Cigir Biray; Kosova, Buket; Iskender, Guniz; Yandim, Melis Kartal; Gunduz, Cumhur; Sahin, Fahri; Baran, Yusuf; Saydam, Guray

2013-07-01

178

Ozone-induced alterations in arachidonic acid metabolism in cultured lung cell types  

SciTech Connect

One of the most sensitive cells to ozone (O/sub 3/) damage is the pulmonary endothelial cell which may mediate the response of the lung to injury by productions of the autacoid prostacyclin (PGl/sub 2/), a metabolite of arachidonic acid. Exposure of endothelial cell cultures to ozone produced a concentration dependent decreases in the synthesis of PGl/sub 2/. Release of /sup 3/H-arachidonic acid from endothelial cells was increased after two hours of 0.3 and 1.0 ppm O/sub 3/ exposure while incubation of cells with 20 ..mu..M and arachidonate (4 min) after exposure resulted in a decreased PGl/sub 2/ synthesis. Cells exposed to 1.0 ppm O/sub 3/ did not have a decreased PGl/sub 2/ production when incubated with 5 ..mu..M PGH/sub 2/ immediately after exposure. These results are consistent with an O/sub 3/-induced inhibition of cyclooxygenase activity. O/sub 3/ exposure (1.0 ppm) produced a rapid decrease in endothelial PGl/sub 2/ synthesis. The data suggest that cyclooxygenase was not inactivated by increased autooxidation due to metabolism of increased free arachidonate. PGl/sub 2/ synthesis returned to control amounts within 12 hours after ozone exposure similar to the recovery time of irreversibly inhibited cyclooxygenase suggesting that recovery was due to de novo synthesis of enzyme. Lipid peroxides and/or hydrogen peroxide (H/sub 2/O/sub 2/) may have caused the inhibition of cyclooxygenase. Incubation of cells with catalase (5 U/ml) protected against the O/sub 3/-induced depression in PGl/sub 2/ synthesis. Exogenously added H/sub 2/O/sub 2/ (greater than or equal to 75 ..mu..M) caused a stimulation of basal PGl/sub 2/ production but depressed arachidonate-stimulated synthesis. O/sub 3/ exposure (2 hr, 1.0 ppm) produced altered metabolism of arachidonate in other important lung cell types, e.g., a decreased PGl/sub 2/ synthesis in smooth muscle cultures. Exposure of lung macrophages to O/sub 3/ caused an increase in almost all arachidonate metabolites produced.

Madden, M.C.

1986-01-01

179

38 CFR 4.87 - Schedule of ratings-ear.  

Code of Federal Regulations, 2013 CFR

...6208Malignant neoplasm of the ear (other than skin only) 100 Note: A rating of 100... 6209Benign neoplasms of the ear (other than skin only): Rate on impairment of function. 6210Chronic otitis externa:...

2013-07-01

180

38 CFR 4.87 - Schedule of ratings-ear.  

Code of Federal Regulations, 2012 CFR

...6208Malignant neoplasm of the ear (other than skin only) 100 Note: A rating of 100... 6209Benign neoplasms of the ear (other than skin only): Rate on impairment of function. 6210Chronic otitis externa:...

2012-07-01

181

38 CFR 4.87 - Schedule of ratings-ear.  

Code of Federal Regulations, 2011 CFR

...6208Malignant neoplasm of the ear (other than skin only) 100 Note: A rating of 100... 6209Benign neoplasms of the ear (other than skin only): Rate on impairment of function. 6210Chronic otitis externa:...

2011-07-01

182

38 CFR 4.87 - Schedule of ratings-ear.  

...87 Schedule of ratings—ear. Diseases of the Ear Rating 6200Chronic suppurative otitis media, mastoiditis, or cholesteatoma (or any combination): During suppuration, or with aural polyps 10 Note: Evaluate hearing impairment,...

2014-07-01

183

Middle Ear Infection (Chronic Otitis Media) and Hearing Loss  

MedlinePLUS

Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Middle Ear Infection (Chronic Otitis Media) and Hearing Loss Patient Health Information News media interested in covering the latest from AAO-HNS/ ...

184

14 CFR 67.105 - Ear, nose, throat, and equilibrium.  

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105 Ear, nose...equilibrium. Ear, nose, throat, and equilibrium standards for a first-class airman medical certificate are: (a) The...

2014-01-01

185

Tympanosclerosis of the ear drum. A scanning electronmicroscopic study.  

PubMed

15 specimens from tympanosclerotic ear drums were studied by scanning electron microscope. Comparative studies were made in 5 normal ear drums and 21 specimens from ear drums in secretory otitis media. Calcification of the ear drum affected mainly the fibrous layer. The submucosa seemed stiff with congested vessels. The degeneration and calcification in the fibrous layer started medially near the submucosa, involving the inner circular fibres first. Signs of regeneration were seen, with fibrocyte-like cells producing fibrils. PMID:7257755

Møller, P

1981-01-01

186

Acid mediates a prolonged antinociception via substance P signaling in acid-induced chronic widespread pain  

PubMed Central

Background Substance P is an important neuropeptide released from nociceptors to mediate pain signals. We recently revealed antinociceptive signaling by substance P in acid-sensing ion channel 3 (ASIC3)-expressing muscle nociceptors in a mouse model of acid-induced chronic widespread pain. However, methods to specifically trigger the substance P antinociception were still lacking. Results Here we show that acid could induce antinociceptive signaling via substance P release in muscle. We prevented the intramuscular acid-induced hyperalgesia by pharmacological inhibition of ASIC3 and transient receptor potential V1 (TRPV1). The antinociceptive effect of non-ASIC3, non-TRPV1 acid signaling lasted for 2 days. The non-ASIC3, non-TRPV1 acid antinociception was largely abolished in mice lacking substance P. Moreover, pretreatment with substance P in muscle mimicked the acid antinociceptive effect and prevented the hyperalgesia induced by next-day acid injection. Conclusions Acid could mediate a prolonged antinociceptive signaling via the release of substance P from muscle afferent neurons in a non-ASIC3, non-TRPV1 manner. PMID:24886508

2014-01-01

187

Getting Teens to Read with Their Ears  

ERIC Educational Resources Information Center

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…

Fues, Marianne Cole

2009-01-01

188

Diving injuries to the inner ear  

Microsoft Academic Search

Two skin divers and 7 SCUBA divers, all men, aged 21–33 years, are presented. The injury occurred at shallow depths and difficulties with pressure equilibration to the ears were a common complaint. Vertigo and hearing losses. When a perilymph fistula is suspected and decompression sickness can be in the round, the other in the oval window. The latter patient also

O. I. Molvær; E. Natrud; S. Eidsvik

1978-01-01

189

The Fine Structure of the Insect Ear  

Microsoft Academic Search

A brief account is given of observations of the fine structure of the insect ear by light microscopy. The observations generally confirm those of previous workers. The electron microscope has revealed many new structures in the ganglion. Problems of the structure of the neuron and its sensory hair, the scolopale, and the relationships of the membranes of the neuron and

E. G. Gray

1960-01-01

190

Ectopic muscle in the middle ear  

Microsoft Academic Search

An ectopic muscle was found in the hypotympanum of a 31-year-old Japanese male. The muscle produced symptoms quite similar to those seen in cases of glomus jugulare tumor: a red mass visible through the ear drum, conductive deafness, a compressed jugular bulb demonstrable by retrograde jugulography, and VIIth and IXth nerve paresis. However, the audible pulsating tinnitus of glomus jugulare

Kiyotaka Murata; Haruo Saito; Manabi Hinoki

1977-01-01

191

Ear Tracking: Visualizing Auditory Localization Strategies  

E-print Network

Ear Tracking: Visualizing Auditory Localization Strategies W. Joseph King Suzanne J. Weghorst Human further cluttering the visual channel. Auditory displays may be used to reinforce the information which,weghorst}@hitl.washington.edu ABSTRACT Auditory displays are an ongoing topic of human computer interaction researchandhave been shown

Washington at Seattle, University of

192

Do Your Ears Pop in Space?  

Microsoft Academic Search

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

Robert Lambourne

1997-01-01

193

Ear Acupuncture in European Traditional Medicine  

Microsoft Academic Search

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.

Luigi Gori; Fabio Firenzuoli

2007-01-01

194

Ca2+ Signaling in the Inner Ear  

NSDL National Science Digital Library

The inner ear contains delicate sensory receptors that have adapted to detect the minutest mechanical disturbances. Ca2+ ions are implicated in all steps of the transduction process, as well as in its regulation by an impressive ensemble of finely tuned feedback control mechanisms. Recent studies have unveiled some of the key players, but things do not sound quite right yet.

2007-04-01

195

Middle Ear Implantable Hearing Devices: An Overview  

PubMed Central

Hearing loss affects approximately 30 million people in the United States. It has been estimated that only approximately 20% of people with hearing loss significant enough to warrant amplification actually seek assistance for amplification. A significant interest in middle ear implants has emerged over the years to facilitate patients who are noncompliant with conventional hearing aides, do not receive significant benefit from conventional aides, or are not candidates for cochlear implants. From the initial studies in the 1930s, the technology has greatly evolved over the years with a wide array of devices and mechanisms employed in the development of implantable middle ear hearing devices. Currently, these devices are generally available in two broad categories: partially or totally implantable using either piezoelectric or electromagnetic systems. The authors present an up-to-date overview of the major implantable middle ear devices. Although the current devices are largely in their infancy, indications for middle ear implants are ever evolving as promising studies show good results. The totally implantable devices provide the user freedom from the social and practical difficulties of using conventional amplification. PMID:19762429

Haynes, David S.; Young, Jadrien A.; Wanna, George B.; Glasscock, Michael E.

2009-01-01

196

Carbon Dioxide Exchange via the Mucosa in Healthy Middle Ear  

Microsoft Academic Search

Background: Recent studies have shown that gas ex- change via the middle ear mucosa, which is performed be- tween the middle ear cleft and capillaries in the submu- cosal connective tissue, has an essential role in ventilation and pressure regulation in the middle ear cleft. We specu- lated that gas exchange via the mucosa is induced by the gas diffusion

Fumio Ikarashi; Sugata Takahashi; Yutaka Yamamoto

1999-01-01

197

Early Ear Problems and Developmental Problems at School Age  

Microsoft Academic Search

Retrospective history of middle ear disease was compared with developmental diagnosis in 507 consecutively referred school-age children. History of major ear problems was positively associated with discrepancies between the performance and verbal IQ on the WISC-R. History of major ear problems was positively associated with the presence of articulation disorders for children in the low social class, hyperactivity in the

Ronald L. Lindsay; Terry Tomazic; Barbara Y. Whitman; Pasquale J. Accairdo

1999-01-01

198

The ear and its malformations: strange beliefs and misconceptions  

Microsoft Academic Search

Objective. To explore the strange beliefs and misconceptions related to the ear and its malformations, and how these have changed from ancient times until today.Methods. Ancient documents, journal articles, and history books were studied to research ancient and current beliefs and misconceptions with regard to the ear and its malformations.Results. The ear has been the centre of various beliefs and

Irene E Gamatsi; Thomas P Nikolopoulos; Dimitra E Lioumi

2003-01-01

199

Sources of Variability in Reflectance Measurements on Normal Cadaver Ears  

E-print Network

-ear lesions for all ages, (2) determine the duration of fluid in the ears of children prone to otitis media closed off at the aditus ad antrum (small air space). Results: Measurement-location effects are generally systematically as the measurement location moves away from the tympanic membrane but in other ears the effects

Allen, Jont

200

Sources of Variability in Reflectance Measurements on Normal Cadaver Ears  

Microsoft Academic Search

Objectives: The development of acoustic reflectance measurements may lead to noninvasive tests that provide information currently unavailable from standard audiometric testing. One factor limiting the development of these tests is that normal-hear- ing human ears show substantial intersubject vari- ations. This work examines intersubject variability that results from measurement location within the ear canal, estimates of ear-canal area, and varia-

Susan E. Voss; Nicholas J. Horton; Rebecca R. Woodbury; Kathryn N. Sheffield

2008-01-01

201

Functional evaluation of iodoacetic acid induced photoreceptor degeneration in the cat.  

PubMed

Iodoacetic acid (IAA) has been applied to different species to acutely induce photoreceptor degeneration. The purpose of the present study was to use this toxin to thoroughly eliminate photoreceptors and induce complete blindness in the cat. IAA was delivered by single ear vein injection (20 mg kg(-1)). Six months after the IAA treatment, functional evaluations including pupillary light reflex (PLR), electroretinogram (ERG), visual behavior tests were performed. Morphological examinations were carried out after the functional evaluation. The present result shows that, six months after the IAA application, animals lost visual functions and became completely blind. High dose IAA application via ear vein delivery created an acute and reliable complete photoreceptor degeneration model in the cat. This model can be applied to genetic and cellular therapies for visual function restoration. PMID:23657794

Nan, Yan; Zhang, Qin; Ren, Chaoran; Huang, Xin; Gao, Jie; Li, Xiaoxin; Pu, Mingliang

2013-06-01

202

Mouse Middle Ear Ion Homeostasis Channels and Intercellular Junctions  

PubMed Central

Hypothesis The middle ear contains homeostatic mechanisms that control the movement of ions and fluids similar to those present in the inner ear, and are altered during inflammation. Background The normal middle ear cavity is fluid-free and air-filled to allow for effective sound transmission. Within the inner ear, the regulation of fluid and ion movement is essential for normal auditory and vestibular function. The same ion and fluid channels active in the inner ear may have similar roles with fluid regulation in the middle ear. Methods Middle and inner ears from BALB/c mice were processed for immunohistochemistry of 10 specific ion homeostasis factors to determine if similar transport and barrier mechanisms are present in the tympanic cavity. Examination also was made of BALB/c mice middle ears after transtympanic injection with heat-killed Haemophilus influenza to determine if these channels are impacted by inflammation. Results The most prominent ion channels in the middle ear included aquaporins 1, 4 and 5, claudin 3, ENaC and Na+,K+-ATPase. Moderate staining was found for GJB2, KCNJ10 and KCNQ1. The inflamed middle ear epithelium showed increased staining due to expected cellular hypertrophy. Localization of ion channels was preserved within the inflamed middle ear epithelium. Conclusions The middle ear epithelium is a dynamic environment with intrinsic mechanisms for the control of ion and water transport to keep the middle ear clear of fluids. Compromise of these processes during middle ear disease may underlie the accumulation of effusions and suggests they may be a therapeutic target for effusion control. PMID:22720014

Morris, Lisa M.; DeGagne, Jacqueline M.; Kempton, J. Beth; Hausman, Frances; Trune, Dennis R.

2012-01-01

203

Cystine glutamate exchanger upregulation by retinoic acid induces neuroprotection in neural stem cells.  

PubMed

Oxidative stress and excitotoxic injury are commonly associated with several neurodegenerative diseases, such as Parkinson's disease, Alzheimer's disease, and periventricular leukomalacia. As cystine is imported into the cell, it is used in the synthesis of intracellular glutathione, an important antioxidant necessary for the defense of brain cells from oxidative stress and glutamate-mediated excitotoxicity. Recent studies have shown that retinoic acid increases the activity of glutathione synthesis and exhibits neuroprotective properties in brain cells. Previously, we have shown that the regulation of the cystine glutamate exchanger (system Xc(-)) also leads to neuroprotection. Here, we examined the effects of retinoic acid on the regulation of system Xc(-). Our results suggest that retinoic acid-induced neuroprotection is mediated through system Xc(-) by regulating glutathione biosynthesis. PMID:21716153

Crockett, Stephanie; Clarke, Melinda; Reeves, Shari; Sims, Brian

2011-08-24

204

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

SciTech Connect

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.

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

1986-03-05

205

Expression analysis for genes involved in arachidonic acid biosynthesis in Mortierella alpina CBS 754.68  

PubMed Central

The time courses for production of fungal biomass, lipid, phenolic and arachidonic acid (ARA) as well as expression of the genes involved in biosynthesis of ARA and lipid were examined in Mortierella alpina CBS 754.68. A significant increase in the arachidonic acid content in lipids that coincided with reduced levels of lipid was obtained. Reduced gene expression occurred presumably due to the steady reduction of carbon and nitrogen resources. However, these energy resources were inefficiently compensated by the breakdown of the accumulated lipids that in turn, induced up-regulated expression of the candidate genes. The results further indicated that the expression of the GLELO encoding gene is a rate-limiting step in the biosynthesis of ARA in the early growth phase. PMID:25242926

Samadlouie, Hamid-Reza; Hamidi-Esfahani, Zohreh; Alavi, Seyed-Mehdi; Varastegani, Boshra

2014-01-01

206

Expression analysis for genes involved in arachidonic acid biosynthesis in Mortierella alpina CBS 754.68.  

PubMed

The time courses for production of fungal biomass, lipid, phenolic and arachidonic acid (ARA) as well as expression of the genes involved in biosynthesis of ARA and lipid were examined in Mortierella alpina CBS 754.68. A significant increase in the arachidonic acid content in lipids that coincided with reduced levels of lipid was obtained. Reduced gene expression occurred presumably due to the steady reduction of carbon and nitrogen resources. However, these energy resources were inefficiently compensated by the breakdown of the accumulated lipids that in turn, induced up-regulated expression of the candidate genes. The results further indicated that the expression of the GLELO encoding gene is a rate-limiting step in the biosynthesis of ARA in the early growth phase. PMID:25242926

Samadlouie, Hamid-Reza; Hamidi-Esfahani, Zohreh; Alavi, Seyed-Mehdi; Varastegani, Boshra

2014-01-01

207

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

PubMed Central

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

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

208

Theory of forward and reverse middle-ear transmission applied to otoacoustic emissions in infant and adult ears  

PubMed Central

The purpose of this study is to understand why otoacoustic emission (OAE) levels are higher in normal-hearing human infants relative to adults. In a previous study, distortion product (DP) OAE input/output (I/O) functions were shown to differ at f2=6 kHz in adults compared to infants through 6 months of age. These DPOAE I/O functions were used to noninvasively assess immaturities in forward/reverse transmission through the ear canal and middle ear [Abdala, C., and Keefe, D. H., (2006). J. Acoust Soc. Am. 120, 3832–3842]. In the present study, ear-canal reflectance and DPOAEs measured in the same ears were analyzed using a scattering-matrix model of forward and reverse transmission in the ear canal, middle ear, and cochlea. Reflectance measurements were sensitive to frequency-dependent effects of ear-canal and middle-ear transmission that differed across OAE type and subject age. Results indicated that DPOAE levels were larger in infants mainly because the reverse middle-ear transmittance level varied with ear-canal area, which differed by more than a factor of 7 between term infants and adults. The forward middle-ear transmittance level was ?16 dB less in infants, so that the conductive efficiency was poorer in infants than adults. PMID:17348521

Keefe, Douglas H.; Abdala, Carolina

2008-01-01

209

Analysis of OH Bolted Ear Connection  

SciTech Connect

The D0 endcap calorimeter outer hadronic (OH) modules play a major structural role in the calorimeter assembly. The disrete modules, once connected together, form a ring within which other massive calorimetry will reside. It has been proposed that the connection of the OH at the downstream end be accomplished by extending the downstream endplates in the radial direction to form 'ears', and then through-bolting between adjacent ears as shown in Fig. 1. A single 2 1/4 in. dia. bolt is used, and previous calculations have determined that the design load on this joint should be 130,000 lbs tension. The high load and serious consequences of failure make this a critical component in the calorimeter assembly. The purpose of this analysis is to investigate the stresses in the connection and other mechanical characteristics which determine joint performance.

Wands, Bob; /Fermilab

1987-12-30

210

?6Fatty acid desaturase from an arachidonic acid-producing Mortierella fungus  

Microsoft Academic Search

A DNA fragment was cloned from the fungal strain, Mortierella alpina 1S-4 (which is used industrially to produce arachidonic acid), after PCR amplification with oligonucleotide primers designed based on the sequence information for ?6-desaturase genes (from borage and Caenorhabditis elegans), which are involved in the desaturation of linoleic acid (?9, ?12–18:2) to ?-linolenic acid (?6, ?9, ?12–18:3). This fragment was

Eiji Sakuradani; Michihiko Kobayashi; Sakayu Shimizu

1999-01-01

211

Effects of synthetic sphingosine-1-phosphate analogs on arachidonic acid metabolism and cell death  

Microsoft Academic Search

Sphingolipid metabolites such as sphingosine regulate cell functions including cell death and arachidonic acid (AA) metabolism. d-erythro-C18-Sphingosine-1-phosphate (d-e-S1P), a sphingolipid metabolite, acts as an intracellular messenger in addition to being an endogenous ligand of some cell surface receptors. The development of S1P analogs may be useful for studying and\\/or regulating S1P-mediated cellular responses. In the present study, we found that

Hiroyuki Nakamura; Yuko Takashiro; Tetsuya Hirabayashi; Syunji Horie; Yuuki Koide; Atsushi Nishida; Toshihiko Murayama

2004-01-01

212

Calcium-dependent phospholipid catabolism and arachidonic acid mobilization in cerebral minces  

Microsoft Academic Search

Cerebral minces were used to investigate the role of calcium influx on trauma-induced alterations of brain lipid metabolism.\\u000a Cerebral phospholipids, nonpolar lipids, and free fatty acids were radiolabeled in vivo with [3H]arachidonic acid. Tissue incubation stimulated the time-dependent catabolism of choline and inositol glycerophospholipids,\\u000a and resulted in the accumulation of [3H]free fatty acids. These effects were attenuated in Ca2+-free incubations,

Derek S. Damron; Robert V. Dorman

1990-01-01

213

Brain arachidonic and docosahexaenoic acid cascades are selectively altered by drugs, diet and disease  

Microsoft Academic Search

Metabolic cascades involving arachidonic acid (AA) and docosahexaenoic acid (DHA) within brain can be independently targeted by drugs, diet and pathological conditions. Thus, AA turnover and brain expression of AA-selective cytosolic phospholipase A2 (cPLA2), but not DHA turnover or expression of DHA-selective Ca2+-independent iPLA2, are reduced in rats given agents effective against bipolar disorder mania, whereas experimental excitotoxicity and neuroinflammation

Stanley I. Rapoport

2008-01-01

214

Media optimization of Parietochloris incisa for arachidonic acid accumulation in an outdoor vertical tubular photobioreactor  

Microsoft Academic Search

The green alga Parietochloris incisa contains a significant amount of the nutritionally valuable polyunsaturated fatty acid and arachidonic acid (AA) and is being\\u000a considered for mass cultivation for commercial AA production. This study was primarily aimed to define a practical medium\\u000a formulation that can be used in commercial mass cultivation that will contribute to a substantial increase in the AA

Hazel Guevarra Tababa; Seishiro Hirabayashi; Kazuyuki Inubushi

215

Effects of thromboxane synthetase inhibition on arachidonate metabolism and platelet behaviour  

PubMed Central

1 The effects of the thromboxane synthetase inhibitor dazoxiben (UK 37248) on arachidonic acid and collagen-induced platelet aggregation and arachidonate acid metabolism were studied both in vitro and ex vivo in the presence and absence of sources of prostaglandin I2 synthetase. 2 In platelets activated by exogenous arachidonic acid, the anti-aggregatory activity of dazoxiben was weak compared with indomethacin, despite comparable inhibition of TXB2 production. This was due to the accumulation of pro-aggregatory metabolites, principally endoperoxides. 3 The anti-aggregatory activity of dazoxiben, both in vitro and ex vivo, was higher and more consistent when platelets were stimulated by collagen, threshold levels of which resulted in an endoperoxide accumulation only 2-3% of that achieved with exogenous arachidonic acid. 4 The anti-aggregatory activity of dazoxiben is enhanced if drug equilibration is facilitated by prolonging the preincubation time from 2 to 15 minutes. 5 Incubation of platelets with pig aortic microsomes, which act both as aggregant and a source of PGI2 synthetase, facilitates the conversion to PGI2 of some endoperoxides accumulated after dazoxiben, resulting in augmented anti-aggregatory activity. 6 Leukocytes as well as blood vessels have the capacity to generate PGI2 from platelet derived endoperoxides. This was demonstrated by the increases in 6-keto-PGF1? accompanying decreased TXB2 production in clotted whole blood from volunteers treated with dazoxiben. 7 It was concluded that a closer approach to in vivo conditions allowing a fuller expression of the mechanism of action of dazoxiben could be achieved in vitro by stimulating platelets with a pathophysiological activator such as collagen in the presence of a source of PGI2 synthetase. PMID:6401997

Parry, M. J.

1983-01-01

216

Molecular Dynamics Simulations of Arachidonic Acid Complexes with COX-1 and COX-2  

PubMed Central

The cyclooxygenase (COX) enzymes are responsible for the committed step in prostaglandin biosynthesis, the generation of prostaglandin H2. As a result, these enzymes are pharmacologically important targets for non-steroidal anti-inflammatory drugs, such as aspirin and newer COX-2 selective inhibitors. The cyclooxygenases are functional homodimers, and each subunit contains both a cyclooxygenase and a peroxidase active site. These enzymes are quite interesting mechanistically, as the conversion of arachidonic acid to prostaglandin H2 requires two oxygenation and two cyclization reactions, resulting in the formation of five new chiral centers with nearly absolute regio- and stereochemical fidelity. We have used molecular dynamics (MD) simulations to investigate the equilibrium behavior of both COX-1 and COX-2 enzyme isoforms with bound arachidonate. These simulations were compared with reference simulations of arachidonate in solution to explore the effect of enzyme on substrate conformation and positioning in the active site. The simulations suggest that the substrate has greater conformational freedom in the COX-2 active site, consistent with the larger COX-2 active site volume observed in X-ray crystal structures. The simulations reveal different conformational behavior for arachidonate in each subunit over the course of extended equilibrium MD simulations. The simulations also provide detailed information for several protein channels that might be important for oxygen and water transport to or from active sites, or for intermediate trafficking between the cyclooxygenase and peroxidase active sites. The detailed comparisons for COX-1 versus COX-2 active site structural fluctuations may also provide useful information for design of new isozyme-selective inhibitors. PMID:16519514

Furse, Kristina E.; Pratt, Derek A.; Porter, Ned A.; Lybrand, Terry P.

2008-01-01

217

Calcium Signals Activated by Arachidonic Acid in Embryonic Chick Ciliary Ganglion Neurons  

Microsoft Academic Search

Arachidonic acid (AA, 20:4) has been reported to modulate a variety of calcium-permeable ionic channels, both in the plasma membrane and in the endoplasmic reticulum. We have studied the effects of AA on calcium signaling in a well-characterized model of developing peripheral neurons, embryonic chick ciliary ganglion neurons in culture. When given at low non-micellar concentrations (5 ?M), in the

Jessica Erriquez; Alessandra Gilardino; Paolo Ariano; Luca Munaron; Davide Lovisolo; Carla Distasi

2005-01-01

218

A simple method for production of arachidonic acid by Mortierella alpina  

Microsoft Academic Search

A filamentous fungus,Mortierella alpina was incubated aerobically on a medium made from potato paste and dextrose at 20 °C for 20 days. The yield of arachidonic acid reached 11.8 g\\/kg medium, which is more than 10 times higher than that by any other method reported previously. The highest content of the acid was 67.4% of the total fatty acids.

Nagao Totani; Kenkichi Oba

1988-01-01

219

A novel two-step fermentation process for improved arachidonic acid production by Mortierella alpina  

Microsoft Academic Search

A novel two-step fermentation process was developed to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1 in a 5 l fermentor. Agitation speed and aeration rate were adjusted from 180 to 40 rpm and from 0.6 to1 vvm, respectively,\\u000a after 5 days cultivation, to decrease physical damage to the mycelia and to extend the stationary phase. Moreover, 3% (w\\/v)\\u000a and 2% (w\\/v) ethanol

Ming-Jie Jin; He Huang; Ai-Hua Xiao; Kun Zhang; Xin Liu; Shuang Li; Chao Peng

2008-01-01

220

Arachidonic acid production by Mortierella alpina with growth-coupled lipid synthesis  

Microsoft Academic Search

The fungus Mortierella alpina LPM 301, a producer of arachidonic acid (ARA), was found to possess a unique property of a growth-coupled lipid synthesis. An increase in specific growth rate (?) from 0.03 to 0.05 h?1 resulted in a two-fold increase in the specific rate of lipid synthesis (milligram lipid (gram per lipid-free biomass) per hour). Under batch cultivation in

V. K. Eroshin; A. D. Satroutdinov; E. G. Dedyukhina; T. I. Chistyakova

2000-01-01

221

Image analysis of morphological change during arachidonic acid production by Mortierella alpina 1S-4  

Microsoft Academic Search

The changes in mycelial morphology during arachidonic acid (AA) production by Mortierella alpina 1S-4 were investigated using an image analysis system. Cultivation was performed in a 10-kl fermentor, and the culture broth was separated into two fractions by sieving (0.5 mm aperture size): the filament fraction (F-fraction, 0.5 mm). The effect of the mycelial morphology in each fraction on AA

Kenichi Higashiyama; Shigeaki Fujikawa; Enoch Y. Park; Mitsuyasu Okabe

1999-01-01

222

Optimization of arachidonic acid production by Mortierella alpina Wuji-H4 isolate  

Microsoft Academic Search

A fungal isolate Wuji-H4 with a dense-lobe rosette growth pattern on malt extract agar was identified as Mortierella alpina Peyronel. It was capable of producing 504 mg\\/L of arachidonic acid (AA) in the screening medium. Its AA content accounted\\u000a for 42.4% of the total fatty acids. The AA yield was raised to 1,817 mg\\/L by a step-by-step approach, which uncovered

H. C. Chen; C. C. Chang; C. X. Chen

1997-01-01

223

Enhancing arachidonic acid production by Mortierella alpina ME1 using improved mycelium aging technology  

Microsoft Academic Search

Traditional mycelium aging technology was improved to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1. Filtration step was skipped and additional carbon and nitrogen sources were fed during aging. The levels of the significant\\u000a factors (time, temperature, ethanol, and KNO3) affecting ARA production during improved aging process were also optimized by applying response surface methodology (RSM),\\u000a and the maximum

Ming-Jie Jin; He Huang; Ai-Hua Xiao; Zhen Gao; Xin Liu; Chao Peng

2009-01-01

224

Enhancement of arachidonic acid production by Mortierella alpina 1S-4  

Microsoft Academic Search

The effect of mineral addition on arachidonic acid (AA) production by Mortierella alpina 1S-4 was evaluated. At first, the addition of minerals such as sodium, potassium, calcium, and magnesium was examined in\\u000a flask cultures, and then the addition of phosphorus with the optimal amounts of the minerals was investigated in a 10-L jar-fermenter.\\u000a As a result, 1.5% soy flour medium

Kenichi Higashiyama; Toshiaki Yaguchi; Kengo Akimoto; Shigeaki Fujikawa; Sakayu Shimizu

1998-01-01

225

Improved arachidonic acids production from the fungus Mortierella alpina by glutamate supplementation  

Microsoft Academic Search

The effect of various concentrations of glutamate on arachidonic acid (AA) production from Mortierella alpina in shaker flask culture was studied. Glutamate supplementation promoted Mortierella growth, accelerated substrate metabolism, and increased AA production, and a concentration of 0.8 g\\/l glutamate resulted in the greatest AA yield (1.41 g\\/l). In 10 l airlift stirred fermenter culture, AA yield in the cultures

L. J Yu; W. M Qin; W. Z Lan; P. P Zhou; M Zhu

2003-01-01

226

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

PubMed

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

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

2003-01-24

227

Tissue selectivity and variability of effects of acetaminophen on arachidonic acid metabolism.  

PubMed

Acetaminophen has variable effects on prostaglandin synthesis depending on the tissue preparation used. The present study was designed to determine the effects of acetaminophen on arachidonic acid metabolism in different tissues simultaneously removed from the same animals treated with the compound. The ex vivo conversion of 14C-arachidonic acid into 14C-prostaglandins was monitored in homogenates or slices of tissues to which no exogenous cofactors were supplied. Administered orally at doses of 100-300 mg/kg to guinea pigs, acetaminophen stimulated prostaglandin production by cell-free preparations of stomach, but had no effect in lung or kidney medulla. At doses ranging from 25-300 mg/kg, p.o., to rats, acetaminophen stimulated stomach, but inhibited cerebral cortex prostaglandin production. These same effects were mimicked qualitatively when acetaminophen was added in vitro at 10(-4)M to 10(-2)M to similar preparations. In addition, at these same high concentrations, acetaminophen inhibited 5-lipoxygenase activity in cultured RBL-1 cells. It is speculated that the multiple and tissue variable effects that acetaminophen had on arachidonic acid metabolism depend on the inherent cofactors associated with each tissue type. PMID:6422475

Tolman, E L; Fuller, B L; Marinan, B A; Capetola, R J; Levinson, S L; Rosenthale, M E

1983-12-01

228

Factors Affecting the Elicitation of Sesquiterpenoid Phytoalexin Accumulation by Eicosapentaenoic and Arachidonic Acids in Potato 1  

PubMed Central

Eicosapentaenoic and arachidonic acids in extracts of Phytophthora infestans mycelium were identified as the most active elicitors of sesquiterpenoid phytoalexin accumulation in potato tuber slices. These fatty acids were found free or esterified in all fractions with elicitor activity including cell wall preparations. Yeast lipase released a major portion of eicosapentaenoic and arachidonic acids from lyophilized mycelium. Concentration response curves comparing the elicitor activity of the polyunsaturated fatty acids to a cell-free sonicate of P. infestans mycelium indicated that the elicitor activity of the sonicated mycelium exceeded that which would be obtained by the amount of eicosapentaenoic and arachidonic acids (free and esterified) present in the mycelium. Upon acid hydrolysis of lyophilized mycelium, elicitor activity was obtained only from the fatty acid fraction. However, the fatty acids accounted for only 21% of the activity of the unhydrolyzed mycelium and the residue did not enhance their activity. Centrifugation of the hydrolysate, obtained from lyophilized mycelium treated with 2n NaOH, 1 molarity NaBH4 at 100°C, yielded a supernatant fraction with little or no elicitor activity. Addition of this material to the fatty acids restored the activity to that which was present in the unhydrolyzed mycelium. The results indicate that the elicitor activity of the unsaturated fatty acids is enhanced by heat and base-stable factors in the mycelium. PMID:16662691

Bostock, Richard M.; Laine, Roger A.; Kuc, Joseph A.

1982-01-01

229

Tumor cell-derived 12(S)-hydroxyeicosatetraenoic acid induces microvascular endothelial cell retraction.  

PubMed

Our previous work demonstrated that the 12-lipoxygenase metabolite of arachidonic acid, 12(S)-hydroxyeicosatetraenoic acid [12(S)-HETE] induced a nondestructive and reversible retraction of cultured endothelial cells. In the current study we tested the hypothesis that tumor cells produce 12(S)-HETE during their interactions with endothelial cells which in turn induces endothelial cell retraction. Coincubation of Lewis lung carcinoma cells or elutriated B16 amelanotic melanoma (B16a) cells but not 3T3 fibroblasts with microvascular endothelial cells (CD3) resulted in a time- and concentration-dependent retraction of the CD3 monolayers as revealed by quantitative binding assays and phase contrast microscopy. Lewis lung carcinoma cell-induced endothelial cell retraction was blocked by specific lipoxygenase inhibitors but not by cyclooxygenase inhibitors, suggesting the involvement of a lipoxygenase metabolite(s). Radioimmunoassay and high-performance liquid chromatography analysis of tumor cell extracts identified 12(S)-HETE as the major lipoxygenase metabolite of arachidonic acid and tumor cell generation of 12(S)-HETE was specifically blocked by a select 12-lipoxygenase inhibitor N-benzyl-N-hydroxy-5-phenyl-pentamide. The identity and stereochemistry of tumor cell-derived 12-HETE was substantiated by gas chromatography-mass spectrometry analysis and chiral phase high-performance liquid chromatography, respectively. Lewis lung carcinoma cell adhesion to CD3 monolayers was accompanied by an enhanced 12(S)-HETE biosynthesis by tumor cells, which paralleled the tumor cell-induced endothelial cell retraction in a cell number-dependent manner. Pretreatment of tumor cells with N-benzyl-N-hydroxy-5-phenylpentamide inhibited both increased 12(S)-HETE biosynthesis and tumor cell-induced endothelial cell retraction. Highly metastatic variants of elutriated B16a cells which had been shown to produce large quantities of 12(S)-HETE induced significant CD3 cell retraction, while low metastatic subpopulations of B16a cells which synthesized no or little 12(S)-HETE did not induce endothelial cell retraction. These results suggest that 12(S)-HETE synthesis during tumor cell-endothelial cell interactions may represent a key contributory factor in cancer metastasis. PMID:8275495

Honn, K V; Tang, D G; Grossi, I; Duniec, Z M; Timar, J; Renaud, C; Leithauser, M; Blair, I; Johnson, C R; Diglio, C A

1994-01-15

230

The glue ear 'epidemic': a historical perspective.  

PubMed

This paper explores the historical context of the dramatic rise in surgery for glue ear in the mid-20th century, and questions the published assertion that this represented a manufactured 'epidemic'. In examining historical sources, the reader's theoretical viewpoint greatly influences their conclusions: the sustained rise in treatment for glue ear may be seen as the advance of science in a golden age or the resistance of insular professionals to reason in the light of new scientific study methods. Current views on the practice of medicine, consumerism, science and standardisation, rationing and the nature of 'truth' all affect the way that we see this period. Technological advances clearly allowed better diagnosis and more effective treatment, but these did not appear to drive an 'epidemic', rather they were developed to meet the pre-existing challenges of otological practice. The proposition that an 'epidemic' was created does not appear to have any solid grounding. Society's perception of what constitutes disease and what needs treatment may have evolved, but the prevalence of other important diseases changed dramatically over this time period, and a real change in the epidemiology of glue ear cannot be dismissed. In defining the case for and against surgical treatment, a solely positivist, quantitative worldview cannot give us a complete picture of benefit and risk to individuals, families and society at large. PMID:21653931

Alderson, David

2011-12-01

231

An investigation of ear necrosis in pigs  

PubMed Central

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

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

2013-01-01

232

Involvement of different protein kinases and phospholipases A2 in phorbol ester (TPA)-induced arachidonic acid liberation in bovine platelets.  

PubMed

The effect of various phospholipase A2 and protein kinase inhibitors on the arachidonic acid liberation in bovine platelets induced by the protein kinase activator 12-O-tetradecanoylphorbol-13-acetate (TPA) was studied. TPA stimulates arachidonic acid release mainly by activating group IV cytosolic PLA2 (cPLA2), since inhibitors of this enzyme markedly inhibited arachidonic acid formation. However, group VI Ca2+-independent PLA2 (iPLA2) seems to contribute to the arachidonic acid liberation too, since the relatively specific iPLA2 inhibitor bromoenol lactone (BEL) decreased arachidonic acid generation in part. The pronounced inhibition of the TPA-induced arachidonic acid release by the protein kinase C (PKC) inhibitors GF 109203X and Ro 31-82220, respectively, and by the p38 MAP kinase inhibitor SB 202190 suggests that the activation of the PLA2s by TPA is mediated via PKC and p38 MAP kinase. PMID:10877452

Lehr, M; Griessbach, K

2000-01-01

233

Oxygenation Response to a Recruitment Maneuver during Supine and Prone Positions in an Oleic Acid-Induced Lung Injury Model  

Microsoft Academic Search

Prone position and recruitment maneuvers (RM) are proposed as adjuncts to mechanical ventilation to open up the lung and keep it open. We studied the oxygenation response to a RM (composed of a 30-s sustained inflation at 60 cm H 2 O airway pressure) per- formed in prone and supine positions in dogs after oleic acid- induced lung injury using

NAHIT CAKAR; THOMAS VAN der KLOOT; MELYNNE YOUNGBLOOD; ALEX ADAMS; AVI NAHUM

2000-01-01

234

Gas exchange function through the middle ear mucosa in piglets: comparative study of normal and inflamed ears.  

PubMed

The gas exchange function through the middle ear (ME) mucosa was investigated by comparing normal and inflamed ears in an animal model. Piglets were examined (n = 15) because their tympanic bulla closely resembles the human mastoid air cell system. Four untreated ears served as controls. Eleven ears were injected with glycerin into the tympanic bulla to induce inflammation and were studied as inflamed ears. Two respiratory conditions, spontaneous respiration and hyperventilation by a ventilator, were alternated repeatedly. ME pressure was measured intermittently by a tympanometer and blood gas was measured simultaneously. In all four normal ears, both ME pressure and carbon dioxide (CO2) partial pressure in the blood decreased in parallel following alternation of the respiratory conditions from spontaneous respiration to hyperventilation, while both pressure levels increased in parallel when respiration was changed from hyperventilation to spontaneous respiration. This result indicates that there is a gas exchange between the ME and the blood through the mucosa. However, ME pressure change in inflamed ears was limited, though the change in CO2 partial pressure in the blood was the same as that in normal ears. There was a significant difference in the degree of ME pressure change occurring in normal ears compared to that in inflamed ears, suggesting that inflammation of the mucosa reduced gas exchange function in the ME. PMID:10219389

Yamamoto, Y

1999-01-01

235

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

PubMed Central

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

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

2014-01-01

236

Ear morphology in Treacher Collins', Apert's, and Crouzon's syndromes.  

PubMed

Size, proportions, level, inclination and shape of the ears were assessed by anthrompometric methods in eight patients with Treacher Collins' syndrome, eleven with Apert's, and 25 with Crouzon's syndrome. The ears were most severely damaged in Treacher Collins' syndrome, in which they were microtic or disproportionally long; many were low-set and with great inclination. All patients with Apert's syndrome had low-set ears and a tendency to disproportion, with widening and small inclination of the longitudinal axis. The ears were least affected in Crouzon's syndrome; in two-thirds of the patients there were mild growth variations leading to disproportion in width (wide ears), or low-set ears, or both. PMID:580574

Farkas, L G

1978-03-01

237

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

PubMed Central

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

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

2014-01-01

238

Review of congenital inner ear abnormalities on CT temporal bone  

PubMed Central

The aetiology of profound hearing loss in children is complex and multifactorial. Congenital inner ear abnormality is a major cause of hearing loss in children. CT temporal bone imaging is the modality of choice in the investigation of hearing loss. Recognising the congenital abnormalities of the inner ear guides the clinician's management of the condition. This pictorial essay illustrates the congenital abnormalities of the inner ear on high resolution CT temporal bone images and correlation with developmental arrest during embryology. PMID:21849370

Yiin, R S Z; Tang, P H; Tan, T Y

2011-01-01

239

A case report of meningioma extending to the middle ear.  

PubMed

Extracranial meningioma with extension into a middle ear is very uncommon. A 74-year-old female was admitted to our hospital with right ear bleeding when removing earwax. In this case, magnetic resonance imaging, computed tomography, her past history and operative findings would consider as infiltrative growth from the right sphenoid ridge meningioma to the right middle ear via the right petrous pyramid and bilateral optic nerve. She underwent only partial extirpation with decompression for optic nerve, rather than total extirpation including middle ear and temporal bone, due to wide invasion of the middle cranial fossa and caversinus sinus. PMID:24765466

Kusunoki, Takeshi; Ikeda, Katsuhisa; Miyashita, Mie

2012-05-29

240

Earth Sciences Research at the National Science Foundation (EAR)  

NSF Publications Database

Earth Sciences Research at the National Science Foundation (EAR) Program Solicitation NSF 04-613 ... approaches. Support is available for research and research infrastructure through grants, contracts ...

241

Cochlear fistula in a noncholesteatomatous ear.  

PubMed

Bony destruction of the labyrinth is usually associated with long-standing cholesteatomatous otitis media. The promontory is not a common site for bone resorption because (1) it is not an area that is involved in accumulation of cholesteatoma perimatrix substances, (2) it is the densest bone of the human body, and (3) pressure necrosis from overlying tissue is uncommon. We report a case of cochlear erosion associated with noncholesteatomatous middle ear disease. As far as we know, this is only the second such case reported in the literature. We also review decision-making factors and techniques for the safe management of this condition. PMID:25255363

Hahn, Yoav; Bojrab, Dennis I

2014-09-01

242

Acid-induced changes in DOC quality in an experimental whole-lake manipulation  

SciTech Connect

Fluorescence analyses of archived water samples were used to typify dissolved organic carbon (DOC) quality in experimentally acidified lakes and reference lakes at the Experimental Lakes Area, in northwestern Ontario. Carbon-specific DOC fluorescence (CSF) during peak acidification was 40--50% of that for a high-DOC reference lake and similar to a low-DOC reference lake. Reference lakes showed similar but smaller decreases in CSF during several years of prolonged drought in the late 1980s. During the 1990s, recovery from acidification resulted in increased CSF, whereas reference lakes remained unchanged during the same time period. In addition to causing decreased [DOC], acidification causes changes in fluorescence-peak geometry that indicate a switch in DOC quality from allochthonous to autochthonous-like during acidification. The acid-induced change in DOC quality was likely due to increased chemical oxidation or precipitation of the UV-absorbent aromatic portions of allochthonous DOC molecules, leaving more UV-transparent aliphatic chains. The change in the nature of DOC following acidification and drought may have an important role in physical, biological, and chemical processes within these lakes. With recovery from acidification, DOC quality has also recovered.

Donahue, W.F.; Schindler, D.W. [Univ. of Alberta, Edmonton (Canada). Dept. of Biological Sciences] [Univ. of Alberta, Edmonton (Canada). Dept. of Biological Sciences; Page, S.J.; Stainton, M.P. [Freshwater Inst., Winnipeg, Manitoba (Canada)] [Freshwater Inst., Winnipeg, Manitoba (Canada)

1998-10-01

243

Cellular bicarbonate protects rat duodenal mucosa from acid-induced injury  

PubMed Central

Secretion of bicarbonate from epithelial cells is considered to be the primary mechanism by which the duodenal mucosa is protected from acid-related injury. Against this view is the finding that patients with cystic fibrosis, who have impaired duodenal bicarbonate secretion, are paradoxically protected from developing duodenal ulcers. Therefore, we hypothesized that epithelial cell intracellular pH regulation, rather than secreted extracellular bicarbonate, was the principal means by which duodenal epithelial cells are protected from acidification and injury. Using a novel in vivo microscopic method, we have measured bicarbonate secretion and epithelial cell intracellular pH (pHi), and we have followed cell injury in the presence of the anion transport inhibitor DIDS and the Cl– channel inhibitor, 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB). DIDS and NPPB abolished the increase of duodenal bicarbonate secretion following luminal acid perfusion. DIDS decreased basal pHi, whereas NPPB increased pHi; DIDS further decreased pHi during acid challenge and abolished the pHi overshoot over baseline observed after acid challenge, whereas NPPB attenuated the fall of pHi and exaggerated the overshoot. Finally, acid-induced epithelial injury was enhanced by DIDS and decreased by NPPB. The results support the role of intracellular bicarbonate in the protection of duodenal epithelial cells from luminal gastric acid. PMID:11748264

Akiba, Yasutada; Furukawa, Osamu; Guth, Paul H.; Engel, Eli; Nastaskin, Igor; Sassani, Pejvak; Dukkipatis, Ramanath; Pushkin, Alexander; Kurtz, Ira; Kaunitz, Jonathan D.

2001-01-01

244

Protective effect of Dillenia indica L. on acetic acid induced colitis in mice.  

PubMed

The inflammatory bowel disease (IBD) is an idiopathic, immune mediated and chronic inflammation of the intestine. The study aimed to elucidate the ameliorative effect of methanolic extract of Dillenia indica (DIME), hexane fraction (HFDI) and chloroform fraction (CFDI) of Dillenia indica in acetic acid induced experimental colitis in mice. Macroscopic score, colon weight, colonic catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), myeloperoxidase (MPO), malondialdehyde (MDA), tumor necrosis factor (TNF-alpha), and histological changes were recorded after the treatment regimen of 7 days. Intra-rectal instillation of acetic acid caused enhanced macroscopic score, colon weight, colonic MPO, MDA, and TNF-alpha level. It caused significant decreased level of CAT, SOD and GSH. DIME (800 mg/kg), HFDI (200 mg/kg) and CFDI (200 mg/kg) treatment exhibited significant effect in lowering macroscopic score, colon weight, MPO, MDA, TNF-alpha levels and elevation of CAT, GSH and SOD levels. The results suggest that D. indica has ameliorating effects on experimental colitis by inhibiting the proinflammatory mediators like TNF-alpha production. PMID:25241587

Somani, S J; Badgujar, L B; Sutariya, B K; Saraf, M N

2014-09-01

245

On the molecular mechanisms of the acid-induced dissociation of hydroxy-apatite in water.  

PubMed

The enamel/saliva interface is mimicked by the comparably much simpler model of (001) surfaces of hydroxy-apatite ( Ca(10)(PO(4))(6)(OH)(2) ) in contact with aqueous solution. At neutral pH, the dissociation of ions is penalized by more than 150 kJ mol(-1) giving rise to very stable apatite-water interfaces. This picture changes drastically with decreasing pH, as the protonation of phosphate and hydroxide ions lowers the free energy of calcium ions dissociation. Our simulations suggest the mechanism of acid-induced apatite decomposition to i) require a considerable degree of protonation of the apatite surface. The first ion dissociation step ii) involves calcium ions which electrostatic binding has been locally destabilized through phosphate and hydroxide protonation. The depletion of calcium ions embedding the anions then allows iii) the dissociation of the anionic species. Along this line, the protective role of fluoride in caries prevention is related to the stabilization of the calcium triangles embedding the OH(-)/F(-) ions. PMID:20886246

Hochrein, Oliver; Zahn, Dirk

2011-06-01

246

Function and Regulation of Retinoic Acid-Inducible Gene-I  

PubMed Central

Antiviral innate immunity is triggered by sensing viral nucleic acids. RIG-I (retinoic acid-inducible gene-I) is an intracellular molecule that responds to viral nucleic acids and activates downstream signaling, resulting in the induction of members of the type I interferon (IFN) family, which are regarded among the most important effectors of the innate immune system. Although RIG-I is expressed ubiquitously in the cytoplasm, its levels are subject to transcriptional and post-transcriptional regulation. RIG-I belongs to the IFN-stimulated gene (ISG) family, but certain cells regulate its expression through IFN-independent mechanisms. Several lines of evidence indicate that deregulated RIG-I signaling is associated with autoimmune disorders. Further studies suggest that RIG-I has functions in addition to those directly related to its role in RNA sensing and host defense. We have much to learn and discover regarding this interesting cytoplasmic sensor so that we can capitalize on its properties for the treatment of viral infections, immune disorders, cancer, and perhaps other conditions. PMID:21175414

Matsumiya, Tomoh; Stafforini, Diana M.

2011-01-01

247

Role of neurosteroids in experimental 3-nitropropionic acid induced neurotoxicity in rats.  

PubMed

Huntington's disease is an autosomal dominant, progressive, and fatal neurodegenerative disease characterized by motor and non-motor symptoms. Systemic administration of 3-nitropropionic acid, a complex II inhibitor of the electron transport chain induces selective striatal lesions in rodents. Neurosteroids are synthesized in central nervous system, able to modulate GABAA receptor function and has been reported to have neuroprotective action. The present study has been designed to investigate the role of neurosteroids such as progesterone and pregnenolone which are positive and negative modulators of GABA respectively against 3-nitropropionic acid induced experimental Huntington's disease. Systemic administration of 3-nitropropionic acid (10mg/kg i.p.) for 14 days significantly reduced body weight, locomotor activity, motor coordination, balance beam walk performance, antioxidant defense enzymes (reduced glutathione and catalase) and significantly increase oxidative stress markers (lipid peroxidation and nitrite level) in striatum and cortex. 3-Nitropropionic acid treatment also increases pro-inflammatory cytokines (TNF-? and IL-1?) level in striatum. Progesterone (10, 20mg/kg/day i.p.) treatments for 14 days significantly reversed the behavioral, antioxidant defense enzymes, oxidative stress marker and pro-inflammatory cytokines as compared to the 3-Nitropropionic acid treated group. Pregnenolone (1 and 2mg/kg i.p.), a negative modulator of GABAA pretreatment significantly reversed the protective effect of progesterone on behavioral and biochemical parameters. The results of the present study suggest that the positive GABAergic modulation may be beneficial for the treatment of motor disorder. PMID:24333475

Kumar, Pushpender; Kumar, Puneet; Khan, Aamir; Deshmukh, Rahul; Lal Sharma, Pyare

2014-01-15

248

Complete reversal of acid-induced acute lung injury by blocking of platelet-neutrophil aggregation  

PubMed Central

Acute lung injury (ALI) causes high mortality, but its molecular mechanisms are poorly understood. Acid aspiration is a frequent cause of ALI, leading to neutrophil sequestration, increased permeability, and deterioration of gas exchange. We investigated the role of platelet-neutrophil interactions in a murine model of acid-induced ALI. Acid aspiration induced P-selectin–dependent platelet-neutrophil interactions in blood and in lung capillaries. Reducing circulating platelets or blocking P-selectin halted the development of ALI. Bone marrow chimeras showed that platelet, not endothelial, P-selectin was responsible for the injury. The interaction of platelets with neutrophils and endothelia was associated with TXA2 formation, with detrimental effects on permeability and tissue function. Activated platelets induced endothelial expression of ICAM-1 and increased neutrophil adhesion. Inhibition of platelet-neutrophil aggregation improved gas exchange, reduced neutrophil recruitment and permeability, and prolonged survival. The key findings were confirmed in a sepsis-induced model of ALI. These findings may translate into improved clinical treatments for ALI. PMID:17143330

Zarbock, Alexander; Singbartl, Kai; Ley, Klaus

2006-01-01

249

Alveolar macrophage function in rats with severe protein calorie malnutrition. Arachidonic acid metabolism, cytokine release, and antimicrobial activity.  

PubMed

To investigate the effects of protein calorie malnutrition (PCM) on alveolar macrophage function, we measured antimicrobial activity, IL-1 and TNF production, and arachidonic acid metabolism in alveolar macrophages of infant rats with moderate and severe PCM. Groups of weanling male rats were fed a diet containing 0.8% protein (PCM) or 24% protein (control). A third group (pair fed) was fed limited amounts of the control diet that matched the mean daily dietary intake of the PCM group. After 4 wk on the diets, alveolar macrophages from all three groups functioned similarly with respect to surface adherence, phagocytosis and killing of Listeria monocytogenes, release of hydrogen peroxide and superoxide anion, and production of IL-1 and TNF. In contrast, Listeria-stimulated alveolar macrophages from the PCM group exhibited a marked shift in arachidonic acid metabolism, with impaired production of leukotriene B4 and enhanced release of thromboxane B2 and PGE2. The membrane arachidonic acid content and the uptake of [3H]arachidonate by alveolar macrophages did not differ among the three groups. The shift toward the cyclooxygenase pathway was not seen after 2 wk of dietary restriction and was reversed if PCM animals were fed the control diet for 1 wk. Thus, PCM does not affect the antimicrobial activity or cytokine production of alveolar macrophages, but causes alterations in arachidonic acid metabolism that may interfere with the modulatory functions of alveolar macrophages. PMID:2104909

Skerrett, S J; Henderson, W R; Martin, T R

1990-02-01

250

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

PubMed Central

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

1979-01-01

251

The distribution and metabolism of arachidonic acid in rabbit platelets during aggregation and its modification by drugs.  

PubMed Central

1 Gas chromatographic and radio-isotope labelling techniques have been used to establish the origin of the arachindonic acid used by the platelet cyclo-oxygenase for the synthesis of pro-aggregatory prostaglandin endoperoxide derivatives. 2 Measurements of total platelet arachidonate content indicated that more than 95% is esterified in the phosphatide fraction of the cells. 3 During aggregation by collagen or thrombin as much as 80% of the total platelet arachidonate may be liberated and transformed by the platelet enzymes into hydroxyacids and other more polar compounds. 4 The phosphatidylethanolamine, phosphatidylcholine and phosphatidylinositol fractions are major sources of the arachidonate thus used. 5 Indomethacin, which prevents platelet aggregation by inhibiting the cyclo-oxygenase, did not affect this release of arachidonate from the phosphatides but did prevent the transformation of arachidonate to endoperoxide derivatives. 6 Mepacrine, a drug which possesses weak anti-phospholipase activity in platelets, also prevents aggregation by collagen or thrombin, but seems to do so by preventing substrate release from the phosphatide fraction. 7 It is suggested that phospholipase A2 plays a key role in the initial events during platelet aggregation induced by collagen. PMID:837023

Blackwell, G J; Duncombe, W G; Flower, R J; Parsons, M F; Vane, J R

1977-01-01

252

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

PubMed

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

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

253

Enhanced visualization of inner ear structures  

NASA Astrophysics Data System (ADS)

Recently surgery requires extensive support from imaging technologies in order to increase effectiveness and safety of operations. One of important tasks is to enhance visualisation of quasi-phase (transparent) 3d structures. Those structures are characterized by very low contrast. It makes differentiation of tissues in field of view very difficult. For that reason the surgeon may be extremly uncertain during operation. This problem is connected with supporting operations of inner ear during which physician has to perform cuts at specific places of quasi-transparent velums. Conventionally during such operations medical doctor views the operating field through stereoscopic microscope. In the paper we propose a 3D visualisation system based on Helmet Mounted Display. Two CCD cameras placed at the output of microscope perform acquisition of stereo pairs of images. The images are processed in real-time with the goal of enhancement of quasi-phased structures. The main task is to create algorithm that is not sensitive to changes in intensity distribution. The disadvantages of existing algorithms is their lack of adaptation to occuring reflexes and shadows in field of view. The processed images from both left and right channels are overlaid on the actual images exported and displayed at LCD's of Helmet Mounted Display. A physician observes by HMD (Helmet Mounted Display) a stereoscopic operating scene with indication of the places of special interest. The authors present the hardware ,procedures applied and initial results of inner ear structure visualisation. Several problems connected with processing of stereo-pair images are discussed.

Niemczyk, Kazimierz; Kucharski, Tomasz; Kujawinska, Malgorzata; Bruzgielewicz, Antoni

2004-07-01

254

[Eustachian tube and middle ear mechanics].  

PubMed

Even the most sophisticated prostheses for reconstruction of the ossicular chain do not work in the presence of Eustachian tube dysfunction. This review gives an update on the mechanisms of middle ear pressure regulation and middle ear ventilation, as well as methods for measuring the opening and closing function of the Eustachian tube. So far, in most tube function tests pressures are applied far beyond the physiological range in order to open the tube or force it to open. New methods like sonotubometry with perfect sequences (PSEQ) or the application of pressure in the nasopharynx with the Estève technique seem very promising. However, these measurements only provide snapshots of tube function. Presently, new tests are being developed for long-term measurements even in cases with perforated tympanic membranes. Attempts to improve impaired tube function have recently included laser surgery and balloon tuboplasty, yielding positive long-term results requiring verification in larger controlled studies. Eustachian tube dysfunction does not only mean blockage but can also include abnormal patencies of the Eustachian tube, for which new approaches are discussed here. In the case of suspected tube dysfunction, cartilage should be used to avoid early tympanic retraction or recurrent perforation; external ventilation using ventilation tubes should be considered. PMID:21909770

Pau, H W

2011-10-01

255

Improved arachidonic acids production from the fungus Mortierella alpina by glutamate supplementation.  

PubMed

The effect of various concentrations of glutamate on arachidonic acid (AA) production from Mortierella alpina in shaker flask culture was studied. Glutamate supplementation promoted Mortierella growth, accelerated substrate metabolism, and increased AA production, and a concentration of 0.8 g/l glutamate resulted in the greatest AA yield (1.41 g/l). In 10 l airlift stirred fermenter culture, AA yield in the cultures exposed to 0.8 g/l glutamate was also greater than that in the control (0.56 g/l). PMID:12618051

Yu, L J; Qin, W M; Lan, W Z; Zhou, P P; Zhu, M

2003-07-01

256

21 CFR 874.3620 - Ear, nose, and throat synthetic polymer material.  

Code of Federal Regulations, 2011 CFR

... Ear, nose, and throat synthetic polymer material. 874.3620 Section 874... Ear, nose, and throat synthetic polymer material. (a) Identification. Ear, nose, and throat synthetic polymer material is a device...

2011-04-01

257

21 CFR 874.3620 - Ear, nose, and throat synthetic polymer material.  

Code of Federal Regulations, 2010 CFR

... Ear, nose, and throat synthetic polymer material. 874.3620 Section 874... Ear, nose, and throat synthetic polymer material. (a) Identification. Ear, nose, and throat synthetic polymer material is a device...

2010-04-01

258

21 CFR 874.4250 - Ear, nose, and throat electric or pneumatic surgical drill.  

Code of Federal Regulations, 2010 CFR

... Ear, nose, and throat electric or pneumatic surgical drill. 874.4250 Section... Ear, nose, and throat electric or pneumatic surgical drill. (a) Identification. An ear, nose, and throat electric or pneumatic surgical drill is a rotating...

2010-04-01

259

21 CFR 874.4250 - Ear, nose, and throat electric or pneumatic surgical drill.  

Code of Federal Regulations, 2013 CFR

... Ear, nose, and throat electric or pneumatic surgical drill. 874.4250 Section... Ear, nose, and throat electric or pneumatic surgical drill. (a) Identification. An ear, nose, and throat electric or pneumatic surgical drill is a rotating...

2013-04-01

260

21 CFR 874.4250 - Ear, nose, and throat electric or pneumatic surgical drill.  

... Ear, nose, and throat electric or pneumatic surgical drill. 874.4250 Section... Ear, nose, and throat electric or pneumatic surgical drill. (a) Identification. An ear, nose, and throat electric or pneumatic surgical drill is a rotating...

2014-04-01

261

21 CFR 874.4250 - Ear, nose, and throat electric or pneumatic surgical drill.  

Code of Federal Regulations, 2012 CFR

... Ear, nose, and throat electric or pneumatic surgical drill. 874.4250 Section... Ear, nose, and throat electric or pneumatic surgical drill. (a) Identification. An ear, nose, and throat electric or pneumatic surgical drill is a rotating...

2012-04-01

262

21 CFR 874.4250 - Ear, nose, and throat electric or pneumatic surgical drill.  

Code of Federal Regulations, 2011 CFR

... Ear, nose, and throat electric or pneumatic surgical drill. 874.4250 Section... Ear, nose, and throat electric or pneumatic surgical drill. (a) Identification. An ear, nose, and throat electric or pneumatic surgical drill is a rotating...

2011-04-01

263

Preterm labor and bacterial intra-amniotic infection: arachidonic acid liberation by phospholipase A2 of Prevotella bivia.  

PubMed

There is a strong association between preterm labor and infection, presumably through an increase in prostaglandin formation. The studies presented in this report were undertaken to evaluate whether Prevotella bivia, a common anaerobic isolate of intrauterine infection, stimulates arachidonic acid metabolism, as a rate-limiting step for prostaglandin synthesis in the human uterine endometrium. When human uterine endometrial cells prelabeled with [3H]arachidonic acid to an isotopically steady state were exposed to an extract of P. bivia, arachidonic acid liberation was stimulated, accompanied by lysophospholipid formation. Similar stimulatory effect on phospholipid degradation was also observed in the experiment with the bacterial conditioned media which was spent as culture media. These results suggests that P. bivia stimulates endometrial phospholipid metabolism, related with activity of phospholipase A2, which might induce the onset of labor associated with intra-amniotic infection. PMID:16887644

Mikamo, H; Kawazoe, K; Sato, Y; Imai, A; Tamaya, T

1998-10-01

264

Modeling of external ear acoustics for insert headphone usage  

Microsoft Academic Search

Although acoustics of the external ear has been studied extensively for auralization and hearing aids, the acoustic behavior with insert headphones is not as well known. Our research focused on the eects of outer ear physical dimensions, particularly to sound pressure at the eardrum. The main parameter was the length of the canal, but eardrum's damping of resonances was also

Marko Hiipakka; Miikka Tikander; Matti Karjalainen

265

The effects of pressure in the middle ear  

Microsoft Academic Search

The magnitude of cochlear responses in 14 ears (cat) was measured by a wave analyser while pressure in the middle ear was increased over a range of 50 mm. Hg. by means of an air system which included a sphygmomanometer gauge. Equal-response curves as a function of frequency depict decreased sensitivity occasioned by stepwise increase in pressure, the effect being

E. G. Wever; C. W. Bray; M. Lawrence

1942-01-01

266

21 CFR 344.12 - Ear drying aid active ingredient.  

...Drugs 5 2014-04-01 2014-04-01 false Ear drying aid active ingredient. 344.12 Section 344.12 Food and...OVER-THE-COUNTER HUMAN USE Active Ingredients § 344.12 Ear drying aid active ingredient. The active ingredient of the...

2014-04-01

267

Fgf19 expression patterns in the developing chick inner ear  

Microsoft Academic Search

The inner ear is a complex sensorial structure with hearing and balance functions. A key aim of developmental biology is to understand the molecular and cellular mechanisms involved in the induction, patterning and innervation of the vertebrate inner ear. These developmental events could be mediated by the expression of regulating genes, such as the members of the family of Fibroblast

Hortensia Sánchez-Calderón; Javier Francisco-Morcillo; Gervasio Martín-Partido; Matías Hidalgo-Sánchez

2007-01-01

268

CT of adenomas of the middle ear and mastoid cavity  

SciTech Connect

A case of mixed type adenoma of the middle ear and mastoid is presented in which CT showed complete opacification of the middle ear and mastoid air cells with bulging of the tympanic membrane but without ossicular or bony destruction. 7 refs., 1 figs.

Van Thong Ho [McGuire Veterans Affairs Medical Center, Richmond, VA (United States); Rao, V.J.; Mikaelian, D.O. [Thomas Jefferson Univ. Hospital and Jefferson Medical College, Philadelphia, PA (United States)

1996-03-01

269

Principles of Local Drug Delivery to the Inner Ear  

Microsoft Academic Search

As more and more substances have been shown in preclinical studies to be capable of preventing damage to the inner ear from exposure to noise, ototoxic drugs, ischemia, infection, inflammation, mechanical trauma and other insults, it is becoming very important to develop feasible and safe methods for the targeted delivery of drugs to specific regions in the inner ear. Recently

Alec N. Salt; Stefan K. Plontke

2009-01-01

270

Anthroposophic vs. conventional therapy of acute respiratory and ear infections  

Microsoft Academic Search

Summary CONTEXT: Acute respiratory and ear symptoms are frequently treated with antibiotics. Anthroposophic treatment of these symptoms relies primarily on anthroposophic medications. OBJECTIVE: To compare anthroposophic treatment to conventional treatment of acute respiratory and ear symptoms regarding clinical outcome, medication use and safety, and patient satisfaction. DESIGN: Prospective, non-randomised comparison of outcomes in patients self-selected to anthroposophic or conventional therapy

Harald J. Hamre; Michael Fischer; Marianne Heger; David Riley; Max Haidvogl; Erik Baars; Eileen Bristol; Michael Evans; Reinhard Schwarz; Helmut Kiene

2005-01-01

271

Medicament contact dermatitis in patients with chronic inflammatory ear disease.  

PubMed

Patch testing of 40 patients with chronic inflammatory ear disease demonstrated medicament allergic contact dermatitis in 35%. The most frequent sensitizers were neomycin, framycetin, clioquinol and gentamicin. Although allergic contact dermatitis to dewaxing ear drops was unusual, irritant reactions were common. PMID:6460100

Holmes, R C; Johns, A N; Wilkinson, J D; Black, M M; Rycroft, R J

1982-01-01

272

Purdue extensionGibberella Ear Rot Purdue extension  

E-print Network

for a pink to reddish mold that begins at the tip of the ear and develops toward the base (Figures 1 and 2 can affect the health of many monogastric animals, but swine are especially sensitive. If Gib ear rot is present, assume that the mycotoxins are also present. A test is needed to deter- mine the level

Holland, Jeffrey

273

[Homologous transplants in the middle ear (author's transl)].  

PubMed

The original concept of tympanoplasty included besides the closure of the middle ear, the removal of pathological middle ear components leaving intact the functional and healthy components. The special conditions that prevail in the middle ear (aeration, absence of intrinsic trauma) allow the reconstruction of the middle ear mechanics to a great extent. Animal experiments and clinical experience reveal good transplantation properties of denatured and preserved ear ossicles. They are partly replaced by the body's own true tissue, and preserve the original form over a period of years. Denatured dear drums with malleus, incus, and parts of the stapes give astounding acoustic results. The posterior bony canal wall in old radical cavities can be replaced by the posterior wall of the human temporal bone which has been preserved in Cialit. PMID:123985

Plester, D

1975-03-01

274

Audiometric Predictions Using SFOAE and Middle-Ear Measurements  

PubMed Central

Objective The goals of the study are to determine how well stimulus-frequency otoacoustic emissions (SFOAEs) identify hearing loss, classify hearing loss as mild 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 function (ATF) measurements in the ear canal account for the variability in normal thresholds, and if the inclusion of ATFs improves the ability of SFOAEs to identify hearing loss and predict pure-tone thresholds. Design The total suppressed SFOAE signal and its corresponding noise were recorded in 85 ears (22 normal ears and 63 ears with sensorineural hearing loss) at octave frequencies from 0.5 – 8 kHz using a nonlinear residual method. SFOAEs were recorded a second time in three impaired ears to assess repeatability. Ambient-pressure ATFs were obtained in all but one of these 85 ears, and were also obtained from an additional 31 normal-hearing subjects in whom SFOAE data were not obtained. Pure-tone air-and bone-conduction thresholds and 226-Hz tympanograms were obtained on all subjects. Normal tympanometry and the absence of air-bone gaps were used to screen subjects for normal middle-ear function. Clinical decision theory was used to assess the performance of SFOAE and ATF predictors in classifying ears as normal or impaired, and linear regression analysis was used to test the ability of SFOAE and ATF variables to predict the air-conduction audiogram. Results The ability of SFOAEs to classify ears as normal or hearing impaired was significant at all test frequencies. The ability of SFOAEs to classify impaired ears as either mild or moderate-severe was significant at test frequencies from 0.5 to 4 kHz. SFOAEs were present in cases of severe hearing loss. SFOAEs were also significantly correlated with air-conduction thresholds from 0.5 to 8 kHz. The best performance occurred using the SFOAE signal-to-noise ratio (S/N) as the predictor, and the overall best performance was at 2 kHz. The SFOAE S/N measures were repeatable to within 3.5 dB in impaired ears. The ATF measures explained up to 25% of the variance in the normal audiogram; however, ATF measures did not improve SFOAEs predictors of hearing loss except at 4 kHz. Conclusions In common with other OAE types, SFOAEs are capable of identifying the presence of hearing loss. In particular, SFOAEs performed better than distortion-product and click-evoked OAEs in predicting auditory status at 0.5 kHz; SFOAE performance was similar to that of other OAE types at higher frequencies except for a slight performance reduction at 4 kHz. Because SFOAEs were detected in ears with mild to severe cases of hearing loss they may also provide an estimate of the classification of hearing loss. Although SFOAEs were significantly correlated with hearing threshold, they do not appear to have clinical utility in predicting a specific behavioral threshold. Information on middle-ear status as assessed by ATF measures offered minimal improvement in SFOAE predictions of auditory status in a population of normal and impaired ears with normal middle-ear function. However, ATF variables did explain a significant fraction of the variability in the audiograms of normal ears, suggesting that audiometric thresholds in normal ears are partially constrained by middle-ear function as assessed by ATF tests. PMID:16230898

Ellison, John C.; Keefe, Douglas H.

2006-01-01

275

Segmentation algorithms for ear image data towards biomechanical studies.  

PubMed

In recent years, the segmentation, i.e. the identification, of ear structures in video-otoscopy, computerised tomography (CT) and magnetic resonance (MR) image data, has gained significant importance in the medical imaging area, particularly those in CT and MR imaging. Segmentation is the fundamental step of any automated technique for supporting the medical diagnosis and, in particular, in biomechanics studies, for building realistic geometric models of ear structures. In this paper, a review of the algorithms used in ear segmentation is presented. The review includes an introduction to the usually biomechanical modelling approaches and also to the common imaging modalities. Afterwards, several segmentation algorithms for ear image data are described, and their specificities and difficulties as well as their advantages and disadvantages are identified and analysed using experimental examples. Finally, the conclusions are presented as well as a discussion about possible trends for future research concerning the ear segmentation. PMID:22994296

Ferreira, Ana; Gentil, Fernanda; Tavares, João Manuel R S

2014-01-01

276

Inner ear symptoms and disease: Pathophysiological understanding and therapeutic options  

PubMed Central

In recent years, huge advances have taken place in understanding of inner ear pathophysiology causing sensorineural hearing loss, tinnitus, and vertigo. Advances in understanding comprise biochemical and physiological research of stimulus perception and conduction, inner ear homeostasis, and hereditary diseases with underlying genetics. This review describes and tabulates the various causes of inner ear disease and defines inner ear and non-inner ear causes of hearing loss, tinnitus, and vertigo. The aim of this review was to comprehensively breakdown this field of otorhinolaryngology for specialists and non-specialists and to discuss current therapeutic options in distinct diseases and promising research for future therapies, especially pharmaceutic, genetic, or stem cell therapy. PMID:24362017

Ciuman, Raphael R.

2013-01-01

277

Diets Rich in Saturated and Polyunsaturated Fatty Acids Induce Morphological Alterations in the Rat Ventral Prostate  

PubMed Central

Aim To evaluate the influence of dietary lipid quality on the body mass, carbohydrate metabolism and morphology of the rat ventral prostate. Materials and Methods Wistar rats were divided into four groups: SC (standard chow), HF-S (high-fat diet rich in saturated fatty acids), HF-P (high-fat diet rich in polyunsaturated fatty acids) and HF-SP (high-fat diet rich in saturated and polyunsaturated fatty acids). We analyzed body mass, fat mass deposits, plasma blood, insulin resistance and the ventral prostate structure. Results Groups that received high-fat diets were heavier and presented larger fat deposits than SC group. The HF-S and HF-SP groups had higher glucose, insulin and total cholesterol serum levels and insulin resistance compared with the SC. The acinar area, epithelium height and area density of the lumen were higher in the HF-SP than in the other groups. The epithelium area density and epithelial cell proliferation were greater in the HF-P and HF-SP than in the SC group. All of the groups that received high-fat diets had greater area density of the stroma, area density of smooth muscle cells and stromal cell proliferation compared with the SC group. Conclusion Diets rich in saturated and/or polyunsaturated fatty acids induced overweight. Independently of insulin resistance, polyunsaturated fatty acids increased prostate stromal and epithelial cell proliferation. Saturated fatty acids influenced only stromal cellular proliferation. These structural and morphometric alterations may be considered risk factors for the development of adverse remodeling process in the rat ventral prostate. PMID:25029463

Furriel, Angelica; Campos-Silva, Pamella; Silva, Paola Cariello Guedes Picarote; Costa, Waldemar Silva; Sampaio, Francisco Jose Barcellos; Gregorio, Bianca Martins

2014-01-01

278

Molecular transport machinery involved in orchestrating luminal acid-induced duodenal bicarbonate secretion in vivo  

PubMed Central

The duodenal villus brush border membrane expresses several ion transporters and/or channels, including the solute carrier 26 anion transporters Slc26a3 (DRA) and Slc26a6 (PAT-1), the Na+/H+ exchanger isoform 3 (NHE3), as well as the anion channels cystic fibrosis transmembrane conductance regulator (CFTR) and Slc26a9. Using genetically engineered mouse models lacking Scl26a3, Slc26a6, Slc26a9 or Slc9a3 (NHE3), the study was carried out to assess the role of these transporters in mediating the protective duodenal bicarbonate secretory response (DBS-R) to luminal acid; and to compare it to their role in DBS-R elicited by the adenylyl cyclase agonist forskolin. While basal DBS was reduced in the absence of any of the three Slc26 isoforms, the DBS-R to forskolin was not altered. In contrast, the DBS-R to a 5 min exposure to luminal acid (pH 2.5) was strongly reduced in the absence of Slc26a3 or Slc26a9, but not Slc26a6. CFTR inhibitor [CFTR(Inh)-172] reduced the first phase of the acid-induced DBS-R, while NHE3 inhibition (or knockout) abolished the sustained phase of the DBS-R. Luminal acid exposure resulted in the activation of multiple intracellular signalling pathways, including SPAK, AKT and p38 phosphorylation. It induced a biphasic trafficking of NHE3, first rapidly into the brush border membrane, followed by endocytosis in the later stage. We conclude that the long-lasting DBS-R to luminal acid exposure activates multiple duodenocyte signalling pathways and involves changes in trafficking and/or activity of CFTR, Slc26 isoforms Slc26a3 and Slc26a9, and NHE3. PMID:24018950

Singh, Anurag Kumar; Liu, Yongjian; Riederer, Brigitte; Engelhardt, Regina; Thakur, Basant Kumar; Soleimani, Manoocher; Seidler, Ursula

2013-01-01

279

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

Microsoft Academic Search

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

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

2008-01-01

280

Self-Ear-Cleaning Among Educated Young Adults in Nigeria  

PubMed Central

Context: Self-ear-cleaning has been reported to be common from several hospital-based studies and it has been associated with some diseases of the ear. Aims: To determine community-based prevalence of self-ear-cleaning and its sociodemographic correlates among educated young adults in Nigeria. Settings and Design: A cross-sectional survey conducted in a National Youth Service Corps camp in Nigeria. Subjects and Methods: Semistructured questionnaires were administered on a randomly selected sample of 1280 respondents. The outcome variable was self-ear-cleaning. Independent variables were sociodemographic variables, materials used and ear-cleaning habits. Statistical Analysis Used: Statistical Package for the Social Sciences (SPSS) version 15 was utilized for univariate, bivariate, and multiple logistic regression analysis. Results: There were 1012 respondents (M: F = 1.05:1). Mean age was 25.3 (standard deviation, 2.34). Prevalence of self-ear-cleaning was 93.4%. Mean age at first cleaning was 7.6 years. Cotton buds were the most frequently used objects (in 85.1%). Prevalence was high irrespective of sociodemographic class, significantly higher among females (?2 = 4.549, P = 0.033), those who believed the habit was beneficial (?2 = 114.185, P < 0.001) and those whose parents and siblings practiced the habit. Significant predictive factors were self-ear-cleaning in respondent's father [odds ratio (OR) P = 0.011) and owning cotton buds (OR = 0.192, P = 0.007). Conclusions: Self-ear-cleaning is almost universal. Most of the population is, therefore, at risk of possible harmful effects. Also, medical advice against self-ear-cleaning is not widely known. Rather, the erroneous perception that self-ear-cleaning is beneficial is common. Collaborative health education efforts targeted at families and schools and campaigns and advocacy for legislation regulating the sale of cotton buds are recommended. PMID:24791230

Olaosun, Adedayo Olugbenga

2014-01-01

281

Uric acid induces fat accumulation via generation of endoplasmic reticulum stress and SREBP-1c activation in hepatocytes.  

PubMed

Non-alcoholic fatty liver disease (NAFLD) is currently one of the most common types of chronic liver injury. Elevated serum uric acid is a strong predictor of the development of fatty liver as well as metabolic syndrome. Here we demonstrate that uric acid induces triglyceride accumulation by SREBP-1c activation via induction of endoplasmic reticulum (ER) stress in hepatocytes. Uric acid-induced ER stress resulted in an increase of glucose-regulated protein (GRP78/94), splicing of the X-box-binding protein-1 (XBP-1), the phosphorylation of protein kinase RNA-like ER kinase (PERK), and eukaryotic translation initiation factor-2? (eIF-2?) in cultured hepatocytes. Uric acid promoted hepatic lipogenesis through overexpression of the lipogenic enzyme, acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and stearoyl-CoA desaturase 1 (SCD1) via activation of SREBP-1c, which was blocked by probenecid, an organic anion transport blocker in HepG2 cells and primary hepatocytes. A blocker of ER stress, tauroursodeoxycholic acid (TUDCA), and an inhibitor of SREBP-1c, metformin, blocked hepatic fat accumulation, suggesting that uric acid promoted fat synthesis in hepatocytes via ER stress-induced activation of SREBP-1c. Uric acid-induced activation of NADPH oxidase preceded ER stress, which further induced mitochondrial ROS production in hepatocytes. These studies provide new insights into the mechanisms by which uric acid stimulates fat accumulation in the liver. PMID:25111690

Choi, Yea-Jin; Shin, Hyun-Soo; Choi, Hack Sun; Park, Joo-Won; Jo, Inho; Oh, Eok-Soo; Lee, Kang-Yo; Lee, Byung-Hoon; Johnson, Richard J; Kang, Duk-Hee

2014-10-01

282

Ear today gone tomorrow’: routine neonatal ear canal cultures are not useful predictors of early onset invasive bacterial sepsis  

Microsoft Academic Search

BackgroundCulture of body surfaces including the ear canal, throat and rectum are often routinely performed on new neonatal unit admissions. It has been postulated that in the early postnatal period the neonatal ear canal may still contain amniotic fluid and thus be superior to other sites for identifying maternally acquired bacteria responsible for early onset neonatal bacterial sepsis. However, the

A J Battersby; R Webster; T Neal; N Subhedar

2011-01-01

283

The prevalence of middle ear pathogens in the outer ear canal and the nasopharyngeal cavity of healthy young adults.  

PubMed

Culturing middle ear fluid samples from children with chronic otitis media with effusion (OME) using standard techniques results in the isolation of bacterial species in approximately 30-50% of the cases. Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, the classic middle ear pathogens of acute otitis media, are involved but, recently, several studies suggested Alloiococcus otitidis as an additional pathogen. In the present study, we used species-specific PCRs to establish the prevalence, in both the nasopharyngeal cavity and the outer ear, of H. influenzae, M. catarrhalis, S. pneumoniae and A. otitidis. The study group consisted of 70 healthy volunteers (aged 19-22 years). The results indicate a high prevalence (>80%) of A. otitidis in the outer ear in contrast to its absence in the nasopharynx. H. influenzae was found in both the outer ear and the nasopharynx (6% and 14%, respectively), whereas S. pneumoniae and M. catarrhalis were found only in the nasopharynx (9% and 34%, respectively).A. otitidis, described as a fastidious organism, were able to be cultured using an optimized culture protocol, with prolonged incubation, which allowed the isolation of A. otitidis in five of the nine PCR-positive samples out of the total of ten samples tested. Given the absence of the outer ear inhabitant A. otitidis from the nasopharynx, its role in the aetiology of OME remains ambiguous because middle ear infecting organisms are considered to invade the middle ear from the nasopharynx through the Eustachian tube. PMID:19895585

De Baere, T; Vaneechoutte, M; Deschaght, P; Huyghe, J; Dhooge, I

2010-07-01

284

Binaural Hearing Relies on the differences in information reaching ears Relies on the differences in information reaching ears  

E-print Network

Binaural Hearing · Relies on the differences in information reaching ears· Relies environments · Fusion: "Two ears but one world" #12;The Major Binaural Cues Interaural Temporal Disparities different nature of input to the binaural processor Frequency Ampl Frequency Ampl Binaural ProcessorBinaural

Oliver, Douglas L.

285

Arachidonic Acid Enhances Caffeine-Induced Cell Death via Caspase-Independent Cell Death  

PubMed Central

Caffeine is a globally consumed psychostimulant but can be fatal to cells at overdose exposures. Although caspase-dependent apoptosis plays a role in caffeine-induced cell death, the responsible intracellular signalling cascade remains incompletely understood. The cellular slime mould, Dictyostelium discoideum, does not possess caspase-dependent apoptotic machinery. Here, we observed that ablation of D. discoideum plaA, which encodes a phospholipase A2 (PLA2) homolog, leads to a decreased rate of cell death under high caffeine concentrations and to enhanced cell death with the addition of arachidonic acid. Moreover, the inhibition of PLA2 activity lead to a recovery of the survival rate in caspase-inhibited Hela cervical carcinoma cells under high caffeine concentrations, indicating that caffeine-induced cell death is enhanced via PLA2-dependent signalling. Our results indicate that arachidonic acid may be a general second messenger that negatively regulates caffeine tolerance via a caspase-independent cell death cascade, which leads to multiple effects in eukaryotic cells. PMID:22896810

Kuwayama, Hidekazu

2012-01-01

286

The target of arachidonic acid pathway is a new anticancer strategy for human prostate cancer  

PubMed Central

Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX) is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of carcinogenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX) is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR)-? is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-? plays a role in both adipocyte differentiation and carcinogenesis. PPAR-? is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-? in human prostate cancer tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-? ligand. PMID:19707453

Matsuyama, Masahide; Yoshimura, Rikio

2008-01-01

287

Percentage oleic acid is inversely related to percentage arachidonic acid in total lipids of rat serum  

PubMed Central

Background Since many health effects of oils rich in oleic acid (18:1, n-9) seem to be opposite those of arachidonic acid (20:4, n-6), i.e. concerning cardiovascular risk, we examined whether % 18:1 might be negatively associated with % 20:4. Methods Fatty acid separation by gas chromatography was performed in total serum lipids of 36 male rats. Using bivariate correlations and multiple linear regressions we studied the association between oleic acid and arachidonic acid. Results We found an inverse relationship (r?=?-0.885, p?

2013-01-01

288

Inhibitory effects of plant-derived flavonoids and phenolic acids on malonaldehyde formation from ethyl arachidonate.  

PubMed

The antioxidant activities of naturally occurring plant compounds were measured in a lipid peroxidation system consisting of ethyl arachidonate and Fenton's reagent. Inhibitory effects of 24 plant-derived flavonoids and 5 phenolic acids on malonaldehyde (MA) formation from ethyl arachidonate were examined using gas chromatography (GC) with a nitrogen-phosphorus detector (NPD). Luteolin, which showed the strongest antioxidant activity, inhibited MA formation by 94% and 97% at the levels of 0.5 and 1.0 mM, respectively. The antioxidant activities of the flavones and flavonols decreased in the following order: luteolin > rhamnetin > fisetin > kaempferol > morin > quercetin. Among the flavanones tested, hesperitin, taxifolin, and naringenin exhibited appreciable antioxidant activities (61-84%) at the 1.0 mM level. The inhibitory effect of epigallocatechin gallate (82.5% at the 1.0 mM level) was the strongest among the flavan-3-ols tested. Ferulic acid had the most potent antioxidant activity (74.6% at the 1.0 mM level) of the phenolic acids tested. PMID:14611194

Lee, Kwang-Geun; Shibamoto, Takayuki; Takeoka, Gary R; Lee, Sung-Eun; Kim, Jeong-Han; Park, Byeoung-Soo

2003-11-19

289

Hydrocortisone selectively inhibits IgE-dependent arachidonic acid release from rat peritoneal mast cells  

SciTech Connect

Purified rat mst cells were used to study the effects of antiinflammatory steroids on the release of (1-14C)-arachidonic acid ((1-14C)AA) and metabolites. Mast cell were incubated overnight with glucocorticoids, (1-14C)AA incorporated into cellular phospholipids and the release of (1-14C)AA, and metabolites determined using a variety of secretagogues. Release of (1-14C)AA and metabolites by concanavalin A, the antigen ovalbumin and anti-immunoglobulin E antibody was markedly reduced by glucocorticoid treatment. Neither the total incorporation of (1-14C)AA nor the distribution into phospholipids was altered by hydrocortisone pretreatment. Glucocorticoid pretreatment did not alter (1-14C)AA release stimulated by somatostatin, compound 48/80, or the calcium ionophore, A23187. These data indicate that antiinflammatory steroids selectively inhibit immunoglobulin dependent release of arachidonic acid from rat mast cells. These findings question the role of lipomodulin and macrocortin as general phospholipase inhibitors and suggest that they may be restricted to immunoglobulin stimuli.

Heiman, A.S.; Crews, F.T.

1984-02-01

290

Equine tracheal epithelial membrane strips - An alternate method for examining epithelial cell arachidonic acid metabolism  

SciTech Connect

Arachidonic acid metabolism by tracheal epithelium can be studied using enzymatically dispersed cell suspensions or cell cultures. Both techniques require considerable tissue disruption and manipulation and may not accurately represent in vivo activity. The authors have developed an alternate method for obtaining strips of equine tracheal epithelium without enzymatic digestion. In the horse, a prominent elastic lamina supports the tracheal epithelium. By physical splitting this lamina, they obtained strips ({le}12 x 1.5 cm) of pseudostratified columnar epithelium attached to a layer of elastic tissue 30-100 {mu}m thick. Epithelial strips (1.2 x 0.5 cm) were attached to plexiglass rods and incubated with ({sup 3}H)arachidonic acid in M199 medium (0.5 {mu}Ci/ml) for 24 hours at 37C. The strips incorporated 36{+-}4% (mean {+-} SEM) of the total radioactivity and released 8.0{+-}1.2% of incorporated radioactivity when stimulated by 5.0 {mu}M calcium ionophore A23187. The extracted supernatant was processed using HPLC, resulting in peaks of radioactivity that co-eluted with authentic PGE{sub 2}, PGF{sub 2}{alpha}, and 12-HETE standards. The greatest activity corresponded to the PGE{sub 2} and PGF{sub 2}{alpha} standards, which is a similar pattern to that reported for cultured human tracheal epithelium.

Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L. (Michigan State Univ., East Lansing (United States) Univ. of Michigan, Ann Arbor (United States))

1990-02-26

291

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

SciTech Connect

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.

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

1988-10-01

292

Squamous carcinoma of the external ear.  

PubMed

The medical records of 486 patients with pathologically proved squamous carcinoma of the skin of the external ear were analyzed. It is a disease of elderly white men, and the helix is the most common site of origin. Well-differentiated squamous carcinoma is the most frequent histologic variant. Ninety-five percent of our patients were treated surgically with above-clavical control in 87 percent and 28 percent survival. The low survival rate was related to the old age of the patients who frequently died of intercurrent disease and second cancers. A 12 percent incidence of nodal metastases is comparable with the incidence reported in other series. Aggressive surgical ablation and the selected use of adjunctive postoperative irradiation appear justified in those patients with locally invasive tumors, multiple nodal metastases, and extracapsular invasion. PMID:6625089

Byers, R; Kesler, K; Redmon, B; Medina, J; Schwarz, B

1983-10-01

293

Increasing dietary linoleic acid does not increase tissue arachidonic acid content in adults consuming Western-type diets: a systematic review  

PubMed Central

Background Linoleic acid, with a DRI of 12-17 g/d, is the most highly consumed polyunsaturated fatty acid in the Western diet and is found in virtually all commonly consumed foods. The concern with dietary linoleic acid, being the metabolic precursor of arachidonic acid, is its consumption may enrich tissues with arachidonic acid and contribute to chronic and overproduction of bioactive eicosanoids. However, no systematic review of human trials regarding linoleic acid consumption and subsequent changes in tissue levels of arachidonic acid has been undertaken. Objective In this study, we reviewed the human literature that reported changes in dietary linoleic acid and its subsequent impact on changing tissue arachidonic acid in erythrocytes and plasma/serum phospholipids. Design We identified, reviewed, and evaluated all peer-reviewed published literature presenting data outlining changes in dietary linoleic acid in adult human clinical trials that reported changes in phospholipid fatty acid composition (specifically arachidonic acid) in plasma/serum and erythrocytes within the parameters of our inclusion/exclusion criteria. Results Decreasing dietary linoleic acid by up to 90% was not significantly correlated with changes in arachidonic acid levels in the phospholipid pool of plasma/serum (p = 0.39). Similarly, when dietary linoleic acid levels were increased up to six fold, no significant correlations with arachidonic acid levels were observed (p = 0.72). However, there was a positive relationship between dietary gamma-linolenic acid and dietary arachidonic acid on changes in arachidonic levels in plasma/serum phospholipids. Conclusions Our results do not support the concept that modifying current intakes of dietary linoleic acid has an effect on changing levels of arachidonic acid in plasma/serum or erythrocytes in adults consuming Western-type diets. PMID:21663641

2011-01-01

294

The value of politzerization in the treatment of atelectatic ears.  

PubMed

The value of Politzerization as a method of treatment in atelectatic ears and secretory otitis media is controversial. In some places it has been used routinely for decades, in others it has been almost forgotten. A quantitative study of its therapeutic value has been difficult to find. The present study is an attempt to evaluate the therapeutic value of such an 'air douche' in atelectatic ears. Thirteen middle ears with atelectasis were Politzerized daily with air or N2 for up to five consecutive days. Once Politzerized, the atelectasis and retraction pockets disappeared in all the ears examined. However, continuous observation of the Politzerized ears with the surgical microscope revealed that all the ear drums returned swiftly to their retracted position. The time it took for a drum to return to its original place varied from 15 minutes up to a maximum of 335 minutes. Our observations show that even an increased number of Politzerizations did not alter the speed of reappearance of the atelectasis. It would therefore seem that the therapeutic value of Politzerization in atelectatic ears is doubtful. PMID:3171367

Luntz, M; Sadé, J

1988-09-01

295

Inverse solution of ear-canal area function from reflectance  

PubMed Central

A number of acoustical applications require the transformation of acoustical quantities, such as impedance and pressure that are measured at the entrance of the ear canal, to quantities at the eardrum. This transformation often requires knowledge of the shape of the ear canal. Previous attempts to measure ear-canal area functions were either invasive, non-reproducible, or could only measure the area function up to a point mid-way along the canal. A method to determine the area function of the ear canal from measurements of acoustic impedance at the entrance of the ear canal is described. The method is based on a solution to the inverse problem in which measurements of impedance are used to calculate reflectance, which is then used to determine the area function of the canal. The mean ear-canal area function determined using this method is similar to mean ear-canal area functions measured by other researchers using different techniques. The advantage of the proposed method over previous methods is that it is non- invasive, fast, and reproducible. PMID:22225043

Rasetshwane, Daniel M.; Neely, Stephen T.

2011-01-01

296

Prenatal Ultrasound Screening for External Ear Abnormality in the Fetuses  

PubMed Central

Objectives. To investigate the best time of examination and section chosen of routine prenatal ultrasound screening for external ear abnormalities and evaluate the feasibility of examining the fetal external ear with ultrasonography. Methods. From July 2010 until August 2011, 42118 pregnant women with single fetus during 16–40 weeks of pregnancy were enrolled in the study. Fetal auricles and external auditory canal in the second trimester of pregnancy were evaluated by routine color Doppler ultrasound screening and systematic screening. Ultrasound images of fetal external ears were obtained on transverse-incline view at cervical vertebra level and mandible level and on parasagittal view and coronal view at external ear level. Results. Five fetuses had anomalous ears including bilateral malformed auricles with malformed external auditory canal, unilateral deformed external ear, and unilateral microtia. The detection rate of both auricles was negatively correlated with gestational age. Of the 5843 fetuses undergoing a routine ultrasound screening, 5797 (99.21%) had bilateral auricles. Of the 4955 fetuses following systematic screening, all fetuses (100%) had bilateral auricles. The best time for fetal auricles observation with ultrasonography is 20–24 weeks of pregnancy. Conclusions. Detection of external ear abnormalities may assist in the diagnosis of chromosomal abnormalities. PMID:25050343

Wei, Jun; Ran, Suzhen; Yang, Zhengchun; Lin, Yun; Tang, Jing

2014-01-01

297

Combined Effect of Fluid and Pressure on Middle Ear Function  

PubMed Central

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

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

2008-01-01

298

Combined effect of fluid and pressure on middle ear function.  

PubMed

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

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

2008-02-01

299

Hydration-state change of horse heart cytochrome c corresponding to trifluoroacetic-acid-induced unfolding.  

PubMed

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 (U(A)) 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-U(A) 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 

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

2013-01-01

300

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

PubMed Central

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

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

2013-01-01

301

Selective antagonism of amino acid-induced and synaptic excitation in the cat spinal cord.  

PubMed

1. The effects of D-alpha-aminoadipate (DalphaAA), D-alpha-aminosuberate (DalphaAS) and other excitatory amino acid antagonists have been compared on the excitatory responses of neurones of the cat spinal cord to acetylcholine, a range of glutamate-related amino acids and stimulation of appropriate excitatory synaptic pathways. The ionophoretic technique was used for administration of excitants and antagonists. 2. DalphaAA and DalphaAS had little or no effect on acetylcholine-induced excitation of Renshaw cells. Responses of either Renshaw cells or dorsal horn neurones in the spinal cord to excitatory amino acids were depressed in the order: N-methyl-D-aspartate (NMDA), L-homocysteate, D-glutamate, ibotenate greater than D-homocysteate, L-aspartate, D-aspartate greater than L-glutamate, kainate and quisqualate. 3. These effects are consistent with the existence of different excitatory amino acid receptors, one type being sensitive to the actions of the antagonists, and activated predominantly by the NMDA group of excitants, with other receptors being relatively insensitive to DalphaAA and DalphaAS and activated predominantly by quisqualate and kainate. On this hypothesis, many amino acids are assumed to have mixed actions on DalphaAA-sensitive and -insensitive receptors. 4. 2-Amino-4-phosphonobutyrate (2APB) and L-glutamic acid diethyl ester (GDEE) produced different patterns of antagonism of excitatory amino acid-induced responses from those observed with DalphaAA and DalphaAS. Neither substance was as potent as DalphaAA or DalphaAS as an excitatory amino acid antagonist. 5. Both DalphaAA and DalphaAS selectively antagonized synaptic excitation of Renshaw cells evoked by dorsal root stimulation without affecting cholinergic excitation of these cells evoked by ventral root stimulation. These latter responses were selectively antagonized by dihydro-beta-erythroidine (DHbetaE). DalphaAA also antagonized synaptic excitation of unidentified dorsal horn neurones of the spinal cord evoked by dorsal root stimulation. Neither GDEE (particularly) nor 2APB were as effective as DalphaAA or DalphaAS as depressants of synaptic excitation. 6. Taken in conjunction with the results of in vitro studies on the specificity of action of Dalpha¿ and related substances, these observations suggest that certain synaptic excitations in the spinal cord are mediated by an excitatory amino acid transmitter, and that this transmitter interacts with receptors which are activated selectively by NMDA, less selectively by other amino acids, including L-aspartate, and probably only slightly by quisqualate, kainate and (exogenous) L-glutamate. PMID:536925

Davies, J; Watkins, J C

1979-12-01

302

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

PubMed Central

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

2010-01-01

303

3D ear identification based on sparse representation.  

PubMed

Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person's identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point)-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm. PMID:24740247

Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying

2014-01-01

304

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

PubMed Central

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

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

2014-01-01

305

Human fetal inner ear involvement in congenital cytomegalovirus infection  

PubMed Central

Background Congenital cytomegalovirus (CMV) infection is a leading cause of sensorineural hearing loss (SNHL). The mechanisms of pathogenesis of CMV-related SNHL are still unclear. The aim is to study congenital CMV-related damage in the fetal inner ear, in order to better understand the underlying pathophysiology behind CMV-SNHL. Results We studied inner ears and brains of 20 human fetuses, all at 21 week gestational age, with a high viral load in the amniotic fluid, with and without ultrasound (US) brain abnormalities. We evaluated histological brain damage, inner ear infection, local inflammatory response and tissue viral load. Immunohistochemistry revealed that CMV was positive in 14/20 brains (70%) and in the inner ears of 9/20 fetuses (45%). In the cases with inner ear infection, the marginal cell layer of the stria vascularis was always infected, followed by infection in the Reissner’s membrane. The highest tissue viral load was observed in the inner ear with infected Organ of Corti. Vestibular labyrinth showed CMV infection of sensory cells in the utricle and in the crista ampullaris. US cerebral anomalies were detected in 6 cases, and in all those cases, the inner ear was always involved. In the other 14 cases with normal brain scan, histological brain damage was present in 8 fetuses and 3 of them presented inner ear infection. Conclusions CMV-infection of the marginal cell layer of the stria vascularis may alter potassium and ion circulation, dissipating the endocochlear potential with consequent SNHL. Although abnormal cerebral US is highly predictive of brain and inner ear damage, normal US findings cannot exclude them either. PMID:24252374

2013-01-01

306

3D Ear Identification Based on Sparse Representation  

PubMed Central

Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person’s identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point)-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm. PMID:24740247

Zhang, Lin; Ding, Zhixuan; Li, Hongyu; Shen, Ying

2014-01-01

307

Shaping sound in space: the regulation of inner ear patterning  

PubMed Central

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

Groves, Andrew K.; Fekete, Donna M.

2012-01-01

308

Tympanosclerosis of the ear drum in secretory otitis media.  

PubMed

Tympanosclerosis of the ear drum in children with SOM differs from normal ear drums in children with SOM. In tympanosclerosis the numbers of fibroblasts, fibrocytes and macrophages are increased in lamina propria and in the submucosa. The collagen microfibrils and procollagen filaments have increased in numbers with a partly disorganized pattern. Fibrolysis of microfibrils is conspicuous and hyaline degeneration appears in areas. Calcareous deposits are found scattered to a limited extent in lamina propria and in the submucosa. Profound calcification could only be found in children with tympanosclerosis coexisting with chronic perforation of the ear drum. PMID:6598264

Møller, P

1984-01-01

309

[Functional examinations of the ear and auditory pathway].  

PubMed

Hearing is usually examined by means of pure tone and speech audiometry. Alternative examinations are required when the level of hearing defect needs to be more closely defined or hearing is being measured from a patient who is unable to give reliable feedback on a test sound. Neonatal hearing screening involves measuring of otoacoustic emissions generated in the cochlea of the inner ear or brain stem responses formed within the auditory pathway. Immittance measurements are used to evaluate the function of the middle ear. Most commonly used methods include tympanometry probing the mobility of the tympanic membrane and middle ear pressure, and acoustic reflex assessing the functionality of the ossicular chain. PMID:21568109

Laitakari, Jaakko; Kokkonen, Jukka

2011-01-01

310

Identification of synergistic signals initiating inner ear development.  

PubMed

Tissue manipulation experiments in amphibians more than 50 years ago showed that induction of the inner ear requires two signals: a mesodermal signal followed by a neural signal. However, the molecules mediating this process have remained elusive. We present evidence for mesodermal initiation of otic development in higher vertebrates and show that the mesoderm can direct terminal differentiation of the inner ear in rostral ectoderm. Furthermore, we demonstrate the synergistic interactions of the extracellular polypeptide ligands FGF-19 and Wnt-8c as mediators of mesodermal and neural signals, respectively, initiating inner ear development. PMID:11110663

Ladher, R K; Anakwe, K U; Gurney, A L; Schoenwolf, G C; Francis-West, P H

2000-12-01

311

Subgridding method for FDTD modeling in the inner ear  

NASA Astrophysics Data System (ADS)

A detailed dosimetry in the inner ear is performed using the FDTD algorithm with a subgridding method. A head model is exposed to a mobile phone radiation and the electromagnetic field in the region of the inner ear is computed with increased numerical resolution by factor of 3, 5 and 7. Results show that increase of the numerical resolution without increase of the geometrical resolution does not give more detailed SAR distribution in the inner ear. Therefore a new model of the cochlea with increasing the geometrical resolution from 1 mm to 1/7 mm and dosimetry in this model is presented.

Kopecky, Rudolf; Persson, Mikael

2004-04-01

312

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...

313

The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition  

Microsoft Academic Search

Numerous studies on perinatal long-chain polyunsaturated fatty acid nutrition have clarified the influence of dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) on central nervous system PUFA concentrations. In humans, omnivorous primates, and piglets, DHA and ARA plasma and red blood cells concentrations rise with dietary preformed DHA and ARA. Brain and retina DHA are responsive to diet while ARA

J. Thomas Brenna; Guan-Yeu Diau

2007-01-01

314

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

Microsoft Academic Search

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:

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

2005-01-01

315

Measurement of arachidonic acid release from human polymorphonuclear neutrophils and platelets: comparison between gas chromatographic and radiometric assays  

SciTech Connect

a simple gas chromatographic method for the assay of phospholipase A2 (PLA2) has been described in which arachidonic acid released from endogenous phospholipid pools is measured following its extraction and derivatization to pentafluorobenzyl esters. Using this assay, PLA2 activities in control and calcium ionophore-stimulated human neutrophils, as well as in control, thrombin, and calcium ionophore stimulated human platelets, have been measured. These values are compared with those obtained by monitoring the release of radioactivity from {sup 3}H- or {sup 14}Carachidonic acid prelabeled cells. While the radiometric assay measures only the release of exogenously incorporated radioactive arachidonic acid, the gas chromatographic assay measures arachidonic acid released from all the endogenous pools. Thus, the apparent increase in PLA2 activity in stimulated cells measured by the gas chromatographic assay is four- to fivefold higher than that by the radiometric assay. Inclusion of fatty acid free bovine serum albumin in the reaction buffer significantly increases the amount of arachidonic acid that is measured by gas chromatography. The gas chromatographic method has also been successfully utilized for measuring PLA2 activity in cell-free preparations derived from physically disrupted human neutrophils.

Ramesha, C.S.; Taylor, L.A. (Department of Inflammation Biology, Syntex Research, Palo Alto, California (USA))

1991-01-01

316

Arachidonic Acid Release from Mammalian Cells Transfected with Human Groups IIA and X Secreted Phospholipase A2 Occurs  

E-print Network

arachidonic acid from mamma- lian cells. Phospholipases A2 (PLA2s)1 are a class of enzymes that re- lease (prostaglandins, leukotrienes, and others) is mediated in mammalian cells by one or more PLA2s. Current evidence favors a role for cytosolic phospholipase A2- (cPLA2- , also known as group IVA PLA2) as a major compo

Gelb, Michael

317

Preliminary safety assessment of an arachidonic acid-enriched oil derived from Mortierella alpina: summary of toxicological data  

Microsoft Academic Search

An arachidonic acid-enriched oil (AA-oil), derived from Mortierella alpina was subjected to a programme of studies to establish its preliminary safety for use in infant nutrition. This was addressed at two levels: (1) HPLC analysis of metabolites produced by the production strains at various conditions, and (2) an evaluation of the toxicity of the final product. The following studies were

R. A. Hempenius; J. M. H. Van Delft; M. Prinsen; B. A. R. Lina

1997-01-01

318

Acute doxorubicin cardiotoxicity alters cardiac cytochrome P450 expression and arachidonic acid metabolism in rats  

SciTech Connect

Doxorubicin (DOX) is a potent anti-neoplastic antibiotic used to treat a variety of malignancies; however, its use is limited by dose-dependent cardiotoxicity. Moreover, there is a strong correlation between cytochrome P450 (CYP)-mediated arachidonic acid metabolites and the pathogenesis of many cardiovascular diseases. Therefore, in the current study, we have investigated the effect of acute DOX toxicity on the expression of several CYP enzymes and their associated arachidonic acid metabolites in the heart of male Sprague-Dawley rats. Acute DOX toxicity was induced by a single intraperitoneal injection of 15 mg/kg of the drug. Our results showed that DOX treatment for 24 h caused a significant induction of CYP1A1, CYP1B1, CYP2C11, CYP2J3, CYP4A1, CYP4A3, CYP4F1, CYP4F4, and EPHX2 gene expression in the heart of DOX-treated rats as compared to the control. Similarly, there was a significant induction of CYP1A1, CYP1B1, CYP2C11, CYP2J3, CYP4A, and sEH proteins after 24 h of DOX administration. In the heart microsomes, acute DOX toxicity significantly increased the formation of 20-HETE which is consistent with the induction of the major CYP omega-hydroxylases: CYP4A1, CYP4A3, CYP4F1, and CYP4F4. On the other hand, the formation of 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs) was significantly reduced, whereas the formation of their corresponding dihydroxyeicosatrienoic acids was significantly increased. The decrease in the cardioprotective EETs can be attributed to the increase of sEH activity parallel to the induction of the EPHX2 gene expression in the heart of DOX-treated rats. In conclusion, acute DOX toxicity alters the expression of several CYP and sEH enzymes with a consequent alteration in arachidonic acid metabolism. These results may represent a novel mechanism by which this drug causes progressive cardiotoxicity.

Zordoky, Beshay N.M.; Anwar-Mohamed, Anwar; Aboutabl, Mona E. [Faculty of Pharmacy and Pharmaceutical Sciences, 3126 Dentistry/Pharmacy Centre, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada); El-Kadi, Ayman O.S., E-mail: aelkadi@pharmacy.ualberta.c [Faculty of Pharmacy and Pharmaceutical Sciences, 3126 Dentistry/Pharmacy Centre, University of Alberta, Edmonton, Alberta, T6G 2N8 (Canada)

2010-01-01

319

Ear-canal standing waves and high-frequency sound calibration using otoacoustic emission probes  

E-print Network

-pressurelevels.The commonlyacceptedreferencefor the input to the middle ear is the sound-pressurelevel (re: 20 pPa) "at the ear- drum." Thisis(the ear- drum: Assumedto terminate the tube at a right angle) (Wiener and Ross, 1946; Gilman etal., 1981Ear-canal standing waves and high-frequency sound calibration using otoacoustic emission probes J

Allen, Jont

320

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

E-print Network

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

Paris-Sud XI, Université de

321

Ear-canal standing waves and high-frequency soundcalibration using otoacousticemissionprobes  

E-print Network

-pressurelevels.The commonlyacceptedreferencefor the input to the middle ear is the sound-pressurelevel (re: 20/zPa) "at the ear- drum canal:Analogousto a uni- formtube) terminatedby a compleximpedance(the ear- drum: Assumedto terminatetheEar-canal standing waves and high-frequency soundcalibration using otoacousticemissionprobes J. H

Allen, Jont

322

Non-acoustic Factors influencing Activity of Middle Ear Muscles in Waking Cats  

Microsoft Academic Search

THE intensity of sound transmitted from the ear drum to the inner ear can be attenuated by contraction of the middle ear muscles, the tensor tympani and stapedius. These muscles contract at the onset of sound, thereby reducing the size of cochlear microphonics as recorded at the round window. Previous explanations of middle ear muscle activity have only considered possible

Peter W. Carmel; Arnold Starr

1964-01-01

323

Laser interferometric vibration measurements of the middle ear in healthy humans  

Microsoft Academic Search

The use of spontaneous and evoked otacoustic emissions is now a standard clinical tool for diagnosis of the function of the inner ear. However, it is not possible to extract this information over the entire, functionally relevant frequency range because of imperfect coupling of: (1) stapedial to ear-drum vibrations through the ossicular chain of the middle ear and (2) ear-drum

J. Rodriguez Jorge; Werner Hemmert; C. Burkhardt; Hans-Peter Zenner; Anthony W. Gummer

1996-01-01

324

The contribution of ear photosynthesis to grain filling in bread wheat ( Triticum aestivum L.)  

Microsoft Academic Search

The contribution of ear photosynthesis to grain filling in wheat (Triticum aestivum L.) is not well known. The main objective of this work was to evaluate this contribution through three different experimental approaches: (1) ear photosynthesis was reduced by removing awns or shading the ears (in combination with a defoliation treatment), (2) grain weight per ear was compared in an

M. L. Maydup; M. Antonietta; J. J. Guiamet; C. Graciano; J. R. López; E. A. Tambussi

2010-01-01

325

Evolution of Gravity Receptors in the Ear  

NASA Technical Reports Server (NTRS)

The general status of a grant to investigate the origins and evolution of two hair cell types in the ears of a teleost fish, Astronotus ocellatus (the oscar), is presented. First, it was demonstrated that the cells in the rostral end of the saccule of the , Carassius auratus, are type 1-like, while those at the caudal end are type 2 cells. It was demonstrated that the dichotomy of hair cell types found in the utricle of the oscar is also found in the goldfish. Second, the lateral line system of the oscar was examined using gentamicin sulphate, an ototocix drug that destroys type 1- like hair cells but does not appear to damage type 2 hair cells. It was demonstrated that the hair cells found in neuromasts of lateral line canal organs were totally destroyed within 1 day of treatment, while the hair cells in free neuromasts were undamaged after 12 days of treatment. Third, it was demonstrated that the calyx, the specialized nerve ending, is not unique to amniotes and that it is present at least in the cristae of semicirular canals in goldfish. These results have demonstrated that: (1) there are multiple hair cell types in the vestibular endorgans of the ear of fishes, (2) these hair cell types are very similar to those found in the mammalian vestibular endorgans, (3) the nerve calyx is also present in fishes, and (4) multiple hair cell types and the calyx have evolved far earlier in the course of vertebrate evolution than heretofore thought. Understanding the structure of the vestibular endorgans has important implications for being able to understand how these organs respond to gravistatic, acceleration and acoustic input. The vestibular endorgans of fishes may provide an ideal system in which to analyze functional differences in hair cells. Not only are the two hair cell types similar to those found in mammals, they are located in very discrete regions in each endorgan. Thus, it is relatively easy to gain access to cells of one or the other type. The presence of two cell types in the lateral line have equally significant implications for studies of the vestibular system.

Popper, Arthur N. (Principal Investigator)

1996-01-01

326

Axonal Gradient of Arachidonic Acid-containing Phosphatidylcholine and Its Dependence on Actin Dynamics*  

PubMed Central

Phosphatidylcholine (PC) is the most abundant component of lipid bilayers and exists in various molecular forms, through combinations of two acylated fatty acids. Arachidonic acid (AA)-containing PC (AA-PC) can be a source of AA, which is a crucial mediator of synaptic transmission and intracellular signaling. However, the distribution of AA-PC within neurons has not been indicated. In the present study, we used imaging mass spectrometry to characterize the distribution of PC species in cultured neurons of superior cervical ganglia. Intriguingly, PC species exhibited a unique distribution that was dependent on the acyl chains at the sn-2 position. In particular, we found that AA-PC is enriched within the axon and is distributed across a proximal-to-distal gradient. Inhibitors of actin dynamics (cytochalasin D and phallacidin) disrupted this gradient. This is the first report of the gradual distribution of AA-PC along the axon and its association with actin dynamics. PMID:22207757

Yang, Hyun-Jeong; Sugiura, Yuki; Ikegami, Koji; Konishi, Yoshiyuki; Setou, Mitsutoshi

2012-01-01

327

The Arachidonic Acid Metabolome Serves as a Conserved Regulator of Cholesterol Metabolism  

PubMed Central

Summary 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 metabolome as conserved regulator of cholesterol metabolism, and identify AA derivatives as promising therapeutics to treat cardiovascular disease in humans.

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

2014-01-01

328

Inhibition of sheep platelet arachidonate metabolism by flavonoids from Spanish and Indian medicinal herbs.  

PubMed

The influence of 22 flavonoids was studied on the arachidonic acid metabolism in sonicated sheep platelets. Flavones and flavonols possessing catechol groups inhibited 12-lipoxygenase. Sideritoflavone and quercetagetin-7-O-beta-D-glucoside were more selective than quercetin. Cirsiliol, hypolaetin, hypolaetin-8-O-beta-D-glucoside, gossypetin, gossypin, hibifolin and leucocyanidol were also 12-lipoxygenase inhibitors with some differences in potency and selectivity. Xanthomicrol was a weak cyclooxygenase inhibitor. These results suggest that lipoxygenase inhibition can play a role in the anti-inflammatory activity of hypolaetin-8-O-beta-D-glucoside, sideritoflavone, gossypin and hibifolin. On the other hand, the presence of sideritoflavone, hypolaetin-8-O-beta-D-glucoside, cirsiliol and xanthomicrol in several species of Sideritis may provide a basis for the use of such plants as anti-inflammatory agents. PMID:2116628

Ferrándiz, M L; Nair, A G; Alcaraz, M J

1990-03-01

329

Enhancing arachidonic acid production by Mortierella alpina ME-1 using improved mycelium aging technology.  

PubMed

Traditional mycelium aging technology was improved to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1. Filtration step was skipped and additional carbon and nitrogen sources were fed during aging. The levels of the significant factors (time, temperature, ethanol, and KNO(3)) affecting ARA production during improved aging process were also optimized by applying response surface methodology (RSM), and the maximum ARA yield of 19.02 g/l was achieved in a 5 l fermentor at 5.6 days, temperature 13.7 degrees C, ethanol 42.44 g/l, and KNO(3) 2.62 g/l. This yield was 1.55 times higher than that of traditional aging technology. The improved mycelium aging technology is considered to be a useful strategy for enhancing ARA production. PMID:18481102

Jin, Ming-Jie; Huang, He; Xiao, Ai-Hua; Gao, Zhen; Liu, Xin; Peng, Chao

2009-01-01

330

Enzymatic hydrolysis and extraction of arachidonic acid rich lipids from Mortierella alpina.  

PubMed

A novel method for efficient arachidonic acid rich lipids extraction was investigated. Six different enzymes (papain, pectinase, snailase, neutrase, alcalase and cellulase) were used to extract lipids from Mortierella alpina. The effects of enzyme concentration, temperature and hydrolysis time on oil recovery were evaluated using factorial experimental design and polynomial regression for each enzyme. Hydrolysis time is found to be the most important parameter for all enzymes. The ratios of enzyme mixtures were also studied. It showed that the mixtures of pectinase and papain (5:3, v/v), pectinase and alcalase (5:1, v/v) were better combined effects on oil yields. The effects of hydrolysis time and temperature were then analyzed by response surface methodology, and oil recoveries were satisfactory (104.6% for pectinase and papain and 101.3% for pectinase and alcalase). In the whole process, the lipid composition was not affected by the enzyme treatments according to fatty acid profile. PMID:21377361

You, Jiang-Ying; Peng, Chao; Liu, Xin; Ji, Xiao-Jun; Lu, Jinmiao; Tong, Qianqian; Wei, Ping; Cong, Leilei; Li, Zhiyong; Huang, He

2011-05-01

331

Improving arachidonic acid accumulation in Mortierella alpina through B-group vitamin addition.  

PubMed

To improve the arachidonic acid (ARA) accumulation in Mortierella alpina, a mixed B-group vitamin addition strategy was developed. The ARA titer reached up to 10.0 g/L, 1.7-fold of the control. At the same time, the highest specific activities of key enzymes involved in ARA biosynthesis, including malic enzyme, glucose-6-phosphate dehydrogenase and ATP: citrate lyase, were 63.3, 38.6 and 53.7% higher than the control, respectively. The possible vitamin triggered improved ARA accumulation mechanism was thus elucidated that B-group vitamins could function as the cofactors of the key enzymes involved in ARA biosynthesis, or precursors for the formation of NADPH and acetyl-CoA which were crucial for ARA synthesis, and strengthened the related metabolic flux. PMID:22052233

Zeng, Yan; Ji, Xiao-Jun; Chang, Shu-Mei; Nie, Zhi-Kui; Huang, He

2012-06-01

332

A novel two-step fermentation process for improved arachidonic acid production by Mortierella alpina.  

PubMed

A novel two-step fermentation process was developed to enhance arachidonic acid (ARA) production by Mortierella alpina ME-1 in a 5 l fermentor. Agitation speed and aeration rate were adjusted from 180 to 40 rpm and from 0.6 to 1 vvm, respectively, after 5 days cultivation, to decrease physical damage to the mycelia and to extend the stationary phase. Moreover, 3% (w/v) and 2% (w/v) ethanol were fed after 5 and 7 days cultivation, respectively, to enhance ARA content of total lipid. Eventually, an ARA yield of 19.8 g/l was achieved, which was 1.7 times higher than that of a one-step fed-batch cultivation. PMID:18256790

Jin, Ming-Jie; Huang, He; Xiao, Ai-Hua; Zhang, Kun; Liu, Xin; Li, Shuang; Peng, Chao

2008-06-01

333

14 CFR 67.205 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205...a second-class airman medical certificate are: ...in one ear or in a sound field environment....

2012-01-01

334

14 CFR 67.205 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205...a second-class airman medical certificate are: ...in one ear or in a sound field environment....

2013-01-01

335

14 CFR 67.305 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305...for a third-class airman medical certificate are: ...in one ear or in a sound field environment....

2013-01-01

336

14 CFR 67.105 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105...for a first-class airman medical certificate are: ...in one ear or in a sound field environment....

2010-01-01

337

14 CFR 67.205 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205...a second-class airman medical certificate are: ...in one ear or in a sound field environment....

2011-01-01

338

14 CFR 67.105 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105...for a first-class airman medical certificate are: ...in one ear or in a sound field environment....

2011-01-01

339

14 CFR 67.305 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305...for a third-class airman medical certificate are: ...in one ear or in a sound field environment....

2011-01-01

340

14 CFR 67.205 - Ear, nose, throat, and equilibrium.  

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205...a second-class airman medical certificate are: ...in one ear or in a sound field environment....

2014-01-01

341

14 CFR 67.205 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Second-Class Airman Medical Certificate § 67.205...a second-class airman medical certificate are: ...in one ear or in a sound field environment....

2010-01-01

342

14 CFR 67.105 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105...for a first-class airman medical certificate are: ...in one ear or in a sound field environment....

2012-01-01

343

14 CFR 67.305 - Ear, nose, throat, and equilibrium.  

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305...for a third-class airman medical certificate are: ...in one ear or in a sound field environment....

2014-01-01

344

14 CFR 67.105 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION First-Class Airman Medical Certificate § 67.105...for a first-class airman medical certificate are: ...in one ear or in a sound field environment....

2013-01-01

345

14 CFR 67.305 - Ear, nose, throat, and equilibrium.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) AIRMEN MEDICAL STANDARDS AND CERTIFICATION Third-Class Airman Medical Certificate § 67.305...for a third-class airman medical certificate are: ...in one ear or in a sound field environment....

2012-01-01

346

Functional measurements of ear pathology in patients and cadaveric preparations  

E-print Network

This work investigated the utility of reflectance (R), a measure of middle-ear mobility, in the differential diagnosis of pathologies responsible for conductive hearing loss (CHL). Current clinical practice cannot distinguish ...

Merchant, Gabrielle Ryan

2014-01-01

347

Ear Problems Approved by the UHS Patient Education Committee  

E-print Network

Impaction occurs when earwax builds up in the canal. It can cause decreased hearing, ear pain, a plugged. Occasionally some individuals produce excess wax and OTC earwax softeners/removal products such as Debrox can

348

40 CFR 211.206-1 - Real ear method.  

Code of Federal Regulations, 2010 CFR

...PROGRAMS PRODUCT NOISE LABELING Hearing Protective Devices § 211...method. (a) The value of sound attenuation to be used in...Measurement of Real-Ear Protection of Hearing Protectors and Physical...in this section. (1) The sound field characteristics...

2010-07-01

349

40 CFR 211.206-1 - Real ear method.  

Code of Federal Regulations, 2011 CFR

...PROGRAMS PRODUCT NOISE LABELING Hearing Protective Devices § 211...method. (a) The value of sound attenuation to be used in...Measurement of Real-Ear Protection of Hearing Protectors and Physical...in this section. (1) The sound field characteristics...

2011-07-01

350

Barotrauma of the ears and sinuses after scuba diving.  

PubMed

The pathophysiology, differential diagnosis, and currently available management of barotrauma affecting the ears and sinuses after scuba diving are reviewed, along with medical standards for resuming scuba diving after barotrauma has resolved. PMID:11407445

Becker, G D; Parell, G J

2001-05-01

351

Forgotten T-tube in the middle ear.  

PubMed

Retention within the middle ear cleft is an unusual complication of T-tube insertion. A 40-year-old woman with Kartagener's Syndrome presented with hearing impairment in the right ear. She was found to have a previously inserted Goode T-tube lying within the middle ear behind an intact drum. She underwent successful removal of the T-tube via a myringotomy, and a new tube was re-inserted. Migration of a T-tube into the middle ear cleft should always be kept in mind in patients who present with otological symptoms and have a history of T-tube insertion, even in the presence of an intact drum. PMID:22538046

Shakeel, Muhammad; Trinidade, Aaron; Khan, Imran; Ah-See, Kim Wong

2012-05-01

352

Tympanostomy Tubes: A Rational Clinical Treatment for Middle Ear Disease.  

ERIC Educational Resources Information Center

The use of tympanostomy tubes to treat middle ear disease including otitis media is discussed with sections on the eustachian tube; acute otitis media; persistent effusion; changes in the tympanic membrane; special populations; and complications. (DB)

Roland, Peter S.; Brown, Orval

1990-01-01

353

In Vitro and In Vivo Activities of Arachidonic Acid against Schistosoma mansoni and Schistosoma haematobium?  

PubMed Central

The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl2 and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy. PMID:20479203

El Ridi, Rashika; Aboueldahab, Marwa; Tallima, Hatem; Salah, Mohamed; Mahana, Noha; Fawzi, Samia; Mohamed, Shadia H.; Fahmy, Omar M.

2010-01-01

354

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

PubMed Central

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

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

2012-01-01

355

Rapid Stimulation of 5-Lipoxygenase Activity in Potato by the Fungal Elicitor Arachidonic Acid 1  

PubMed Central

The activity of lipoxygenase (LOX) in aged potato tuber discs increased by almost 2-fold following treatment of the discs with the fungal elicitor arachidonic acid (AA). Enzyme activity increased above that in untreated discs within 30 min after AA treatment, peaked at 1 to 3 h, and returned to near control levels by 6 h. The majority of the activity was detected in a soluble fraction (105,000g supernatant), but a minor portion was also associated with a particulate fraction enriched in microsomal membranes (105,000g pellet); both activities were similarly induced. 5-Hydroperoxyeicosatetraenoic acid was the principal product following incubation of these extracts with AA. Antibodies to soybean LOX strongly reacted with a protein with a molecular mass of approximately 95-kD present in both soluble and particulate fractions whose abundance generally corresponded with LOX activity in extracts. LOX activity was not enhanced by treatment of the discs with nonelicitor fatty acids or by branched ?-glucans from the mycelium of Phytophthora infestans. Prior treatment of the discs with abscisic acid, salicylhydroxamic acid, or n-propyl gallate, all of which have been shown to suppress AA induction of the hypersensitive response, inhibited the AA-induced increment in LOX activity. Cycloheximide pretreatment, which abolishes AA elicitor activity for other responses such as phytoalexin induction, did not inhibit LOX activity in water- or elicitor-treated discs but enhanced activity similar to that observed by AA treatment. The elicitor-induced increase in 5-LOX activity preceded or temporally paralleled the induction of other studied responses to AA, including the accumulation of mRNAs for 3-hydroxy-3-methylglutaryl coenzyme A reductase and phenylalanine ammonia lyase reported here. The results are discussed in relation to the proposed role of the 5-LOX in signal-response coupling of arachidonate elicitation of the hypersensitive response. Images Figure 4 Figure 7 PMID:16653144

Bostock, Richard M.; Yamamoto, Hiroyuki; Choi, Doil; Ricker, Karin E.; Ward, Bernard L.

1992-01-01

356

Ear decomposition of 3-regular polyhedral links with applications.  

PubMed

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

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

2014-10-21

357

Blackbird and Starling Feeding Behavior on Ripening Corn Ears1  

Microsoft Academic Search

The behavior of red-winged blackbirds {Agelaius phoemcei\\/s), common grackles (Quiscalus quiscula), brown-headed cowbirds (Molothrus ater), and juvenile European starlings (Sturnus vulgaris) feeding on ears of corn was studied in an aviary. The species differed significantly in their propensity to attack (penetrate the husk and feed on kernels) ears of corn. Redwings and starlings were more active attackers than grackles and

GLEN E. BERNHARDT; LYNDA VAN ALLSBURG; RICHARD A. DOLBEER

358

Efficiency of ear protectors in laboratory and real life tests  

Microsoft Academic Search

The effectiveness of ten different ear-protectors (6 types of earmuffs and 4 types of earplugs) has been tested under laboratory conditions and in the real occupational environment. Three methods were used: (1) physical, utilizing a dummy head; (2) subjective, real-ear, executed on trained human subjects; (3) subjective, measuring TTS2 resulting from occupational, one-workday exposure. It could be shown that the

K. Pawlas; J. Grzesik

1990-01-01

359

Melanoacanthoma of External Ear: Report of Two Cases  

PubMed Central

Melanoacanthoma is a rare lesion. Melanoacanthoma of external ear is still rarer. We present two cases of melanoacanthoma of external ear in adults which presented as pigmented growths and clinically were suspected as malignant lesions. Histopathology was diagnostic as it demonstrated the characteristic elevated lesion with abundant melanin pigment. No recurrence of the lesion was reported after four years of initial diagnosis. These cases have been presented because of their uncommon location, highlighting the differential diagnoses. PMID:24014974

Patnayak, Rashmi; Jena, Amitabh; Chowhan, Amit Kumar; Rukmangadha, Nandyala; Reddy, Mandyam Kumaraswamy

2013-01-01

360

Intratympanic Steroids for Inner Ear Disorders: A Review  

Microsoft Academic Search

Background\\/Aim: The use of intratympanic steroids (ITS) has proliferated over the past 10–15 years to include treatments for inner ear disorders, like Ménière’s Disease (MD) and sudden sensorineural hearing loss (SSNHL). The aim of this study was to review the clinical trials of ITS for inner ear disorders. Methods: PubMed and Ovid Medline databases were searched from 1966 to present

Amanda Hu; Lorne S. Parnes

2009-01-01

361

Scalp-Ear-Nipple Syndrome: A Case Report  

PubMed Central

The scalp-ear-nipple (SEN) syndrome is an infrequent congenital disease. Its main features are scalp defects, malformed ears, and absence of nipples. Most of the reported cases are autosomal dominant. We report on a patient suffering SEN syndrome with possible autosomal recessive inheritance. It is concluded that SEN syndrome should be recognized as an entity with genetic heterogeneity once there is evidence of different genetic manner of inheritance described in this disease. PMID:24660003

Morales-Peralta, Estela; Andres, Vivian; Campillo Betancourt, Daine

2014-01-01

362

Mechanics and materials in middle ear reconstruction.  

PubMed

The normal anatomy and physiology of the middle ear is not reproduced in ossiculoplasty and an artificial mechanism for the transmission of sound results. This is true for all types of graft, be they of natural or man-made material. There are, therefore, 2 areas for consideration when looking at the problems encountered in such reconstructions: first, the materials' biocompatability and, secondly, the mechanical effects of the positioning of the graft in the reconstructed ossicular chain. The present work examines these mechanical effects using the finite element method to determine stress and displacement levels in the reconstructed ossicular chain. It is found that the stress levels at the implant-stapedial joint increases as the implant is gradually moved down the malleus. In contrast there is thought to be an increase in sound transmission as the implant is moved down the malleus. Changes in rigidity and hardness of the implant appear to make only modest stress attenuations at the implant-stapes interface. PMID:2032354

Lesser, T H; Williams, K R; Blayney, A W

1991-02-01

363

Experimental evidence against middle ear oxygen absorption.  

PubMed

The present theory of eustachian tube (ET) function and middle ear (ME) ventilation posits that oxygen absorbed by the ME mucosa causes negative ME pressure which is relieved by periodic opening of the ET during swallowing and yawning. After developing a method to cannulate the ET of mongrel dogs we connected the cannulas hermetically to manometers. This system excluded ET function and tested the oxygen absorption capacity of the ME. When we controlled respiration and maintained blood gas PO2 and PCO2 at normal levels, we were unable to find any manometric evidence of negative pressure of gas absorption in the dog ME. Lowering the PCO2 and raising the PO2 of the blood by hyperventilation caused negative ME pressure which could be measured manometrically. We confirmed these findings with the tympanometer. Raising the PCO2 and lowering the PO2 by hypoventilation caused positive pressure in the ME. There is no evidence in these experiments that O2 absorption occurs or causes negative ME pressure in the dog. To the contrary there is evidence that elevated blood levels of the more diffusible CO2 cause an increase in the ME pressure and lowered CO2 level causes a negative ME pressure. PMID:3920459

Buckingham, R A; Stuart, D R; Geick, M R; Girgis, S J; McGee, T J

1985-04-01

364

Genetic parameters for rennet- and acid-induced coagulation properties in milk from Swedish Red dairy cows.  

PubMed

Milk coagulation is an important processing trait, being the basis for production of both cheese and fermented products. There is interest in including technological properties of these products in the breeding goal for dairy cattle. The aim of the present study was therefore to estimate genetic parameters for milk coagulation properties, including both rennet- and acid-induced coagulation, in Swedish Red dairy cattle using genomic relationships. Morning milk samples and blood samples were collected from 395 Swedish Red cows that were selected to be as genetically unrelated as possible. Using a rheometer, milk samples were analyzed for rennet- and acid-induced coagulation properties, including gel strength (G'), coagulation time, and yield stress (YS). In addition to the technological traits, milk composition was analyzed. A binary trait was created to reflect that milk samples that had not coagulated 40min after rennet addition were considered noncoagulating milk. The cows were genotyped by using the Illumina BovineHD BeadChip (Illumina Inc., San Diego, CA). Almost 600,000 markers remained after quality control and were used to construct a matrix of genomic relationships among the cows. Multivariate models including fixed effects of herd, lactation stage, and parity were fitted using the ASReml software to obtain estimates of heritabilities and genetic and phenotypic correlations. Heritability estimates (h(2)) for G' and YS in rennet and acid gels were found to be high (h(2)=0.38-0.62) and the genetic correlations between rennet-induced and acid-induced coagulation properties were weak but favorable, with the exception of YSrennet with G'acid and YSacid, both of which were strong. The high heritability (h(2)=0.45) for milk coagulating ability expressed as a binary trait suggests that noncoagulation could be eliminated through breeding. Additionally, the results indicated that the current breeding objective could increase the frequency of noncoagulating milk and lead to deterioration of acid-induced coagulation through unfavorable genetic associations with protein content (0.38) and milk yield (-0.61 to -0.71), respectively. The outcome of this study suggests that by including more detailed compositional traits genetically associated with milk coagulation or by including milk coagulation properties directly within the breeding goal, it appears possible to breed cows that produce milk better suited for production of cheese and fermented products. PMID:24913648

Gustavsson, F; Glantz, M; Poulsen, N A; Wadsö, L; Stålhammar, H; Andrén, A; Lindmark Månsson, H; Larsen, L B; Paulsson, M; Fikse, W F

2014-08-01

365

Effect of crystal form on in vivo topical anti-inflammatory activity of corticosteroids  

Microsoft Academic Search

The aim of this study was to gain information on the effects of the crystal form of corticosteroids on the topical anti-inflammatory\\u000a activity. Two different crystal forms, Form A and Form B, of the drugs of prednicarbate, hydrocortisone, betamethasone 17-valerate,\\u000a prednisolone, and methyl prednisolone were prepared and their topical anti-inflammatory activities were measured using arachidonic\\u000a acid induced ear edema assay

Young-Taek Sohn; Sun-Young Kim

2002-01-01

366

Lumped parametric model of the human ear for sound transmission.  

PubMed

A lumped parametric model of the human auditoria peripherals consisting of six masses suspended with six springs and ten dashpots was proposed. This model will provide the quantitative basis for the construction of a physical model of the human middle ear. The lumped model parameters were first identified using published anatomical data, and then determined through a parameter optimization process. The transfer function of the middle ear obtained from human temporal bone experiments with laser Doppler interferometers was used for creating the target function during the optimization process. It was found that, among 14 spring and dashpot parameters, there were five parameters which had pronounced effects on the dynamic behaviors of the model. The detailed discussion on the sensitivity of those parameters was provided with appropriate applications for sound transmission in the ear. We expect that the methods for characterizing the lumped model of the human ear and the model parameters will be useful for theoretical modeling of the ear function and construction of the ear physical model. PMID:15300453

Feng, Bin; Gan, Rong Z

2004-09-01

367

Evidence of Inner Ear Contribution in Bone Conduction in Chinchilla  

PubMed Central

We investigated the contribution of the middle ear to the physiological response to bone conduction stimuli in chinchilla. We measured intracochlear sound pressure in response to air conduction (AC) and bone conduction (BC) stimuli before and after interruption of the ossicular chain at the incudo-stapedial joint. Interruption of the chain effectively decouples the external and middle ear from the inner ear and significantly reduces the contributions of the outer ear and middle ear to the bone conduction response. With AC stimulation, both the scala vestibuli Psv and scala tympani Pst sound pressures drop by 30 to 40 dB after the interruption. In BC stimulation, Psv decreases after interruption by about 10 to 20 dB, but Pst is little affected. This difference in the sensitivity of the BC induced Psv and Pst to ossicular interruption is not consistent with a BC response to ossicular motion, but instead suggests a significant contribution of an inner-ear drive (e.g. cochlear fluid inertia or compressibility) to the BC response. PMID:23211609

Chhan, David; Roosli, Christof; McKinnon, Melissa L.; Rosowski, John J.

2013-01-01

368

Minnesota wolf ear lengths as possible indicators of taxonomic differences  

USGS Publications Warehouse

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.

Mech, L. David

2011-01-01

369

Developmental origin and fate of middle ear structures.  

PubMed

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

Sienknecht, Ulrike J

2013-07-01

370

Erythema associated with pain and warmth on face and ears: a variant of erythermalgia or red ear syndrome?  

PubMed Central

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

2014-01-01

371

The evaluation of ear canal, middle ear, temporal bone, and cerebellopontine angle masses in infants, children, and adolescents.  

PubMed

Ear canal, middle ear, temporal bone, and CPA angle masses (except for cholesteatomas) are rare in the pediatric population. The physician needs to have a high degree of suspicion for such lesions if a child presents with ear pain unrelated to infection or otorrhea that fails to improve after treatment. A precise diagnosis needs to be made in these children and also in those with hearing loss, vertigo, and facial paralysis. The most useful imaging procedures for ear, temporal bone, and CPA masses are CT and MR imaging. With a suspected vascular lesion, a definitive diagnosis usually can be made by an imaging procedure or angiography. In all cases of mass lesions, except for some aneurysms and infections, a tissue diagnosis must be secured. PMID:1442313

Bellet, P S; Benton, C; Matt, B H; Myer, C M

1992-01-01

372

TRPM5 is critical for linoleic acid-induced CCK secretion from the enteroendocrine cell line, STC-1  

PubMed Central

Fatty acid-induced stimulation of enteroendocrine cells leads to release of the hormones such as cholecystokinin (CCK) that contribute to satiety. Recently, the fatty acid activated G protein-coupled receptor GPR120 has been shown to mediate long-chain unsaturated free fatty acid-induced CCK release from the enteroendocrine cell line, STC-1, yet the downstream signaling pathway remains unclear. Here we show that linoleic acid (LA) elicits membrane depolarization and an intracellular calcium rise in STC-1 cells and that these responses are significantly reduced when activity of G proteins or phospholipase C is blocked. LA leads to activation of monovalent cation-specific transient receptor potential channel type M5 (TRPM5) in STC-1 cells. LA-induced TRPM5 currents are significantly reduced when expression of TRPM5 or GPR120 is reduced using RNA interference. Furthermore, the LA-induced rise in intracellular calcium and CCK secretion is greatly diminished when expression of TRPM5 channels is reduced using RNA interference, consistent with a role of TRPM5 in LA-induced CCK secretion in STC-1 cells. PMID:21998136

Shah, Bhavik P.; Liu, Pin; Yu, Tian; Hansen, Dane R.

2012-01-01

373

What is otitis media? Otitis media is an inflammation of the middle ear that usually occurs as the result of a middle ear  

E-print Network

into the tympanic membrane (ear drum). The tube allows any fluid to drain out and helps keeps the air pressure· What is otitis media? Otitis media is an inflammation of the middle ear that usually occurs as the result of a middle ear infection. Common symptoms can include fever, pain, hearing problems, ruptured

O'Toole, Alice J.

374

Conserved valproic-acid-induced lipid droplet formation in Dictyostelium and human hepatocytes identifies structurally active compounds  

PubMed Central

SUMMARY Lipid droplet formation and subsequent steatosis (the abnormal retention of lipids within a cell) has been reported to contribute to hepatotoxicity and is an adverse effect of many pharmacological agents including the antiepileptic drug valproic acid (VPA). In this study, we have developed a simple model system (Dictyostelium discoideum) to investigate the effects of VPA and related compounds in lipid droplet formation. In mammalian hepatocytes, VPA increases lipid droplet accumulation over a 24-hour period, giving rise to liver cell damage, and we show a similar effect in Dictyostelium following 30 minutes of VPA treatment. Using 3H-labelled polyunsaturated (arachidonic) or saturated (palmitic) fatty acids, we shown that VPA treatment of Dictyostelium gives rise to an increased accumulation of both types of fatty acids in phosphatidylcholine, phosphatidylethanolamine and non-polar lipids in this time period, with a similar trend observed in human hepatocytes (Huh7 cells) labelled with [3H]arachidonic acid. In addition, pharmacological inhibition of ?-oxidation in Dictyostelium phenocopies fatty acid accumulation, in agreement with data reported in mammalian systems. Using Dictyostelium, we then screened a range of VPA-related compounds to identify those with high and low lipid-accumulation potential, and validated these activities for effects on lipid droplet formation by using human hepatocytes. Structure-activity relationships for these VPA-related compounds suggest that lipid accumulation is independent of VPA-catalysed teratogenicity and inositol depletion. These results suggest that Dictyostelium could provide both a novel model system for the analysis of lipid droplet formation in human hepatocytes and a rapid method for identifying VPA-related compounds that show liver toxicology. PMID:22003123

Elphick, Lucy M.; Pawolleck, Nadine; Guschina, Irina A.; Chaieb, Leila; Eikel, Daniel; Nau, Heinz; Harwood, John L.; Plant, Nick J.; Williams, Robin S. B.

2012-01-01

375

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

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

WANG, YUXIA; JI, MINGLI; WANG, LEI; CHEN, LIPING; LI, JING

2014-01-01

376

The ear converts the pressure amplitude variations of sound waves into sensations that we can perceive. The central point to be gleaned from this description is that the ear  

E-print Network

push on the eardrum. Because the other side of the ear drum (known as the middle ear) is held at a fairly constant pressure the sound causes the eardrum to vibrate. 2. The vibrations of the ear drumThe Ear The ear converts the pressure amplitude variations of sound waves into sensations that we

Robertson, William

377

MODULATION OF COX I AND COX II-MEDIATED FORMATION OF VARIOUS ARACHIDONIC ACID METABOLITES IN VITRO AND IN VIVO BY DIETARY POLYPHENOLS  

E-print Network

Cyclooxygenase (COX) is a key enzyme required for the conversion of arachidonic acid (AA) to various prostaglandins (PGs), thromboxanes (TXs), and hydroxyeicosatetraenoic acids (HETEs), by which AA exert numerous biological actions in the body...

Bai, Hyoungwoo

2009-12-03

378

In vitro release of arachidonic acid metabolites, glutathione peroxidase, and oxygen-free radicals from platelets of asthmatic patients with and without aspirin intolerance  

Microsoft Academic Search

BACKGROUND--An abnormal platelet release of oxygen-free radicals has been described in acetylsalicylic acid (aspirin)-induced asthma, a finding which might suggest the existence of an intrinsic, specific platelet abnormality of arachidonic acid metabolism in these patients. The objective of this study was to evaluate platelet arachidonic acid metabolism in asthmatic patients with or without intolerance to aspirin. METHODS--Thirty subjects distributed into

V Plaza; J Prat; J Rosellò; E Ballester; I Ramis; J Mullol; E Gelpí; J L Vives-Corrons; C Picado

1995-01-01

379

Purification by silica gel chromatography using dialysis tubing and characterization of sophorolipids produced from Candida bombicola grown on glucose and arachidonic acid  

Microsoft Academic Search

The yeast Candida bombicola (ATCC 22214) grown on primary carbon source glucose (100 g l?1) and secondary carbon, arachidonic acid (2 g l?1) produced mixture of sophorolipids up to 1.44 g l?1. The crude product was a heterogeneous mixture of sophorolipids, which are glycolipids of sophorose linked to the fatty acid\\u000a through glycosidic bond between ? and ??1 carbon of arachidonic acid. The

Sachin Shah; Asmita Prabhune

2007-01-01

380

Arachidonic acid metabolism in normal and transformed rat tracheal epithelial cells and its possible role in the regulation of cell proliferation.  

PubMed

The objectives of our investigations were to characterize the profile of arachidonic acid metabolites produced by cultured rat tracheal epithelial cells, and to determine whether or not transformation of these cells causes major qualitative or quantitative changes in arachidonic acid metabolism and whether arachidonic acid metabolites play an important role in the regulation of proliferation of rat tracheal cells. Our studies showed that prostaglandin E2 was the only major prostanoid produced by normal and transformed rat tracheal epithelial cells. When stimulated with calcium ionophore A23187, 12-O-tetradecanoylphorbol 13-acetate, arachidonic acid, or serum, the cultures produced small amounts of thromboxane B2, prostaglandin F2 alpha, and hydroxyeicosatetraenoic acid(s) in addition to prostaglandin E2. Mitogenesis studies showed that none of the peptide growth factors tested stimulated either prostaglandin E2 production or DNA synthesis. Fetal bovine serum, on the other hand, stimulated both. 12-O-Tetradecanoylphorbol 13-acetate and arachidonic acid stimulated prostaglandin E2 production but caused no increase in DNA synthesis. Dexamethasone and indomethacin, inhibitors of phospholipase A2 and cyclooxygenase, respectively, significantly inhibited prostaglandin E2 production at concentrations as low as 10(-8) and 10(-9) M but did not inhibit DNA synthesis. It is concluded (1) that prostaglandin E2 is the major arachidonic acid metabolite of rat tracheal epithelial cells, (2) that transformation does not significantly alter arachidonic acid metabolism in these cells, and (3) that neither prostaglandin E2 nor other arachidonic acid metabolites play a significant role in mitogenic stimulation of rat tracheal epithelial cells. PMID:2501081

Duniec, Z M; Eling, T E; Jetten, A M; Gray, T E; Nettesheim, P

1989-05-01

381

Finite element modeling of energy absorbance in normal and disordered human ears.  

PubMed

The finite element (FE) model of the human ear has been developed to analyze the middle ear and cochlea function in relation to the ear structures. However, the energy absorbance or energy reflectance used in the research and clinical audiology test has not been reported in the FE model. The relationship between the middle ear structure and the energy absorbance (EA) needs to be identified using the FE model. In this study, a FE model of the human ear, including the ear canal, the middle ear and the spiral cochlea constructed from the histological sections of a human temporal bone, was used to calculate EA. The viscoelastic material properties were applied to the middle ear soft tissues. Three middle ear disorders were simulated in the FE model: otitis media, otosclerosis, and ossicular chain disarticulation. Multi-physics (acoustic, structure, and fluid) coupled analysis was conducted in the model. The FE model was first validated with the published experimental data on the middle ear input impedance and EA of the normal ear. The EA in three disordered ears was obtained from the model and compared with the published results measured in the clinics and the temporal bone experiments. The consistence of the model-derived EA with the published data demonstrates that the FE model is feasible to analyze EA. The effects of middle ear pressure, middle ear effusion, and mechanical properties of soft tissues on EA were estimated and discussed. This article is part of a special issue entitled "MEMRO 2012". PMID:23274858

Zhang, Xiangming; Gan, Rong Z

2013-07-01

382

Human ear detection in the thermal infrared spectrum  

NASA Astrophysics Data System (ADS)

In this paper the problem of human ear detection in the thermal infrared (IR) spectrum is studied in order to illustrate the advantages and limitations of the most important steps of ear-based biometrics that can operate in day and night time environments. The main contributions of this work are two-fold: First, a dual-band database is assembled that consists of visible and thermal profile face images. The thermal data was collected using a high definition middle-wave infrared (3-5 microns) camera that is capable of acquiring thermal imprints of human skin. Second, a fully automated, thermal imaging based ear detection method is developed for real-time segmentation of human ears in either day or night time environments. The proposed method is based on Haar features forming a cascaded AdaBoost classifier (our modified version of the original Viola-Jones approach1 that was designed to be applied mainly in visible band images). The main advantage of the proposed method, applied on our profile face image data set collected in the thermal-band, is that it is designed to reduce the learning time required by the original Viola-Jones method from several weeks to several hours. Unlike other approaches reported in the literature, which have been tested but not designed to operate in the thermal band, our method yields a high detection accuracy that reaches ~ 91.5%. Further analysis on our data set yielded that: (a) photometric normalization techniques do not directly improve ear detection performance. However, when using a certain photometric normalization technique (CLAHE) on falsely detected images, the detection rate improved by ~ 4%; (b) the high detection accuracy of our method did not degrade when we lowered down the original spatial resolution of thermal ear images. For example, even after using one third of the original spatial resolution (i.e. ~ 20% of the original computational time) of the thermal profile face images, the high ear detection accuracy of our method remained unaffected. This resulted also in speeding up the detection time of an ear image from 265 to 17 milliseconds per image. To the best of our knowledge this is the first time that the problem of human ear detection in the thermal band is being investigated in the open literature.

Abaza, Ayman; Bourlai, Thirimachos

2012-06-01

383

Effect of ibudilast on microcirculation thrombosis in rat inner ear.  

PubMed

The effect of ibudilast (0.1, 0.3 mg/kg), which has cerebral vasodilating and antiplatelet effects, was evaluated in two models of rat inner ear microcirculation thrombosis by using the photochemical reaction between green light (wave length: 540 nm) and intravenous injection of rose bengal. Furthermore, the inner ear blood flow was measured by a laser-Doppler flowmeter. In the hearing disturbance model, under anesthesia, the compound action potential of the cochlear nerve (AP) was measured by an electrocochleogram. The sound stimulus was an 8-kHz sine wave at 80 dB SPL. The AP was calculated 128 times. In the controls, the AP disappeared about 4 min after the intravenous injection of rose bengal (20 mg/kg). The time required to completely suppress the AP in the animals treated with ibudilast (0.1, 0.3 mg/kg) was significantly prolonged as compared with that in the controls. In the equilibrium dysfunction model, ibudilast (0.1, 0.3 mg/kg) reduced the time of abnormal swimming in the swimming test 24 hr after the completion of photo-illumination. Ibudilast (0.3 mg/kg) increased the inner ear blood flow during the 10-min observation period as compared with the controls, while it did not affect the mean blood pressure. In conclusion, ibudilast increased the inner ear blood flow and was effective in two models of rat inner ear microcirculation thrombosis. PMID:8459653

Umemura, K; Asai, Y; Hirata, Y; Uematsu, T; Nakashima, M

1993-02-01

384

Anisotropic yield function capable of predicting eight ears  

NASA Astrophysics Data System (ADS)

Deep drawing of a cylindrical cup from a rolled sheet is one of the typical forming operations where the effect of this anisotropy is most evident. Indeed, it is well documented in the literature that the number of ears and the shape of the earing pattern correlate with the r-values profile. For the strongly textured aluminum alloy AA 5042 (Numisheet Benchmark 2011), the experimental r-value distribution has two minima between the rolling and transverse direction data provided for this show that the r-value along the transverse direction (TD) is five times larger than the value corresponding to the rolling direction. Therefore, it is expected that there are more that the earing profile has more than four ears. The main objective of this paper is to assess whether a new form of CPB06ex2 yield function (Plunkett et al. (2008)) tailored for metals with no tension-compression asymmetry is capable of predicting more than four ears for this material.

Yoon, J. H.; Cazacu, O.

2011-08-01

385

Manganese Accumulation in the Mouse Ear Following Systemic Exposure  

PubMed Central

There is evidence in human populations that exposure to manganese (Mn), or Mn in combination with excessive noise exposure, results in hearing loss. Quantitative reverse-transcriptase polymerase chain reaction revealed expression of the metal transporters DMT1, ZIP8, and ZIP14 in control mouse ears. ZIP8 is known to have a high affinity (Km = 2.2 ?M) for Mn transport, and ZIP8 protein was localized to the blood vessels of the ear by immunohistochemistry. We treated mice (strains C57BL/6J and DBA/2J) with Mn (100 mg/kg MnCl2, by subcutaneous injection, on three alternating days), and Mn was significantly elevated in the ears of the treated mice. Mn concentrations remained elevated over controls for at least 2 weeks after treatment. These studies demonstrate that metal transporters are present in the mouse ear and that Mn can accumulate in the ear following systemic exposure. Future studies should focus on whether Mn exposure is associated with hearing deficits. PMID:18972394

Ma, Ci; Schneider, Scott N.; Miller, Marian; Nebert, Daniel W.; Lind, Caroline; Roda, Sandy M.; Afton, Scott E.; Caruso, Joseph A.; Genter, Mary Beth

2009-01-01

386

Tissue concentrations of ofloxacin in the middle ear.  

PubMed

Twenty patients with chronic otitis media underwent tympanoplasty and were given an oral dose (two 200-mg tablets) of a new antibiotic, ofloxacin, three to seven hours before surgery. The study aimed to demonstrate satisfactory concentrations of ofloxacin in the middle ear as the basis for that agent's well-known clinical efficacy. The main pathogens responsible for bacterial infections in the ear, nose, and throat, especially those in the ear, are Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and alpha-streptococci. The chemotherapeutic agent used must reach adequate concentrations in the bone, mucous membrane, and serum. Mucous membrane, bone, and serum samples were obtained from the middle ear and examined for ofloxacin levels. The medication was also administered for a minimum of five days postoperatively. The average serum level of ofloxacin was 2.1 micrograms/ml, and the concentrations in both the mucous membrane and bone (2.2 micrograms/gm) were above the serum levels. The extent to which the concentrations at the possible site of infection exceeded the minimal inhibitory concentrations (MICs) for the pathogens was investigated at our clinic in 190 isolates. The study showed that, with the leading pathogens such as staphylococci, tissue concentrations were about four times higher than the MICs and that even Pseudomonas organisms were effectively inhibited. All patients had a satisfactory clinical response to therapy. The authors thus recommend a dosage of 400 mg of ofloxacin three to five hours prior to surgery for middle ear infection. PMID:3478138

Thorn, V

1987-01-01

387

Beta-adrenergic and arachidonic acid-mediated growth regulation of human breast cancer cell lines.  

PubMed

Adenocarcinoma of the mammary gland is the leading type of cancer in women. Among these breast cancers those that are estrogen-responsive respond well to existing therapeutic regimens while estrogen non-responsive cancers metastasize widely, demonstrate a high relapse rate, and respond poorly to therapy. Over-expression of the arachidonic acid-metabolizing enzymes cyclooxygenase-2 and lypoxygenases is frequently observed in breast cancer, particularly the non-estrogen-responsive type, suggesting a role of the arachidonic acid (AA) cascade in the growth regulation of these malignancies. Adenocarcinomas of the lungs, pancreas and colon also frequently over-express AA-metabolizing enzymes, and recent evidence suggests that the growth-regulating AA-cascade in these malignancies is under beta-adrenergic control. Our current experiments have therefore tested the hypothesis that in analogy to these findings adenocarcinomas of the breast are also regulated by beta-adrenergic receptors via stimulation of the AA-cascade. Analysis of DNA synthesis by [3H]-thymidine incorporation assays in three estrogen-responsive and three estrogen non-responsive cell lines derived from human breast cancers demonstrated a significant reduction in DNA synthesis by beta-blockers and inhibitors of cyclooxygenase or lipoxygenases in all cell lines. Analysis of AA-release in one of the most responsive cell lines demonstrated a time-dependent increase in AA-release in response to the beta-adrenergic agonist isoproterenol. Analysis by RT-PCR revealed expression of beta2-adrenergic receptors in all cell lines whereas beta1-adrenergic receptors were not found in two of the estrogen non-responsive cell lines. Our data suggest that a significant subset of human breast cancers is under control of beta-adrenergic receptors via stimulation of the AA-cascade. These findings open up novel avenues for the prevention and clinical management of breast cancer, particularly the non-estrogen-responsive types. Moreover, our findings suggest that cardiovascular disease and adenocarcinomas in a variety of organ systems, including the breast may share common risk factors and benefit from similar preventive and treatment strategies. PMID:12063562

Cakir, Y; Plummer, H K; Tithof, P K; Schuller, H M

2002-07-01

388

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

PubMed Central

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

Lopez, Daniel H.; Fiol-deRoque, Maria A.; Noguera-Salva, Maria A.; Teres, Silvia; Campana, Federica; Piotto, Stefano; Castro, Jose A.; Mohaibes, Raheem J.; Escriba, Pablo V.; Busquets, Xavier

2013-01-01

389

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

Microsoft Academic Search

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

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

2008-01-01

390

Prostaglandin production from arachidonic acid and evidence for a 9,11-endoperoxide prostaglandin H 2 reductase in Leishmania  

Microsoft Academic Search

Lysates of Leishmania promastigotes can metabolise arachidonic acid to prostaglandins. Prostaglandin production was heat sensitive and not inhibited by aspirin or indomethacin. We cloned and sequenced the cDNA of Leishmania major, Leishmania donovani, and Leishmania tropica prostaglandin F2? synthase, and overexpressed their respective 34-kDa recombinant proteins that catalyse the reduction of 9,11-endoperoxide PGH2 to PGF2?. Database search and sequence alignment

Zakayi Kabututu; Samuel K Martin; Tomoyoshi Nozaki; Shin-ichiro Kawazu; Tetsuya Okada; Craig Joe Munday; Michael Duszenko; Michael Lazarus; Lucy W Thuita; Yoshihiro Urade; Bruno Kilunga Kubata

2002-01-01

391

Products of arachidonic acid metabolism and the effects of cyclooxygenase inhibition on ongoing cutaneous allergic reactions in human beings  

Microsoft Academic Search

Background: There have been conflicting reports about the effects of inhibition of arachidonic acid metabolism on early- and late-phase cutaneous reactions. We re-examined this question with a unique nonsteroidal antiinflammatory drug, tenidap sodium. Tenidap sodium has been demonstrated in in vitro studies to inhibit cyclooxygenase, lipoxygenase, and cytokine production (interleukin-1, interleukin-6, tumor necrosis factor-?). Methods: In a double-blind, randomized, crossover

Paul C. Atkins; Burton Zweiman; Bruce Littman; Charles Presti; Carolyn von Allmen; Anne Moskovitz; J. D. Eskra

1995-01-01

392

Dietary supplementation with arachidonic and docosahexaenoic acids has no effect on pulmonary surfactant in artificially reared infant rats  

Microsoft Academic Search

Despite the potential use of long-chain polyunsaturated fatty acid (LCPUFA) supplementation to promote growth and neural development\\u000a of the infant, little is known about potential harmful effects of the supplementation. The present study determined whether\\u000a supplementation with arachidonic acid (AA) and\\/or docosahexaenoic acid (DHA) in rat milk formula (RMF) affects saturation\\u000a of pulmonary surfactant phospholipids (PL). Beginning at 7 d

Yu-Yan Yeh; Kerry Anne Whitelock; Shaw-Mei Yeh; Eric L. Lien

1999-01-01

393

Preclinical evaluation of single-cell oils that are highly enriched with arachidonic acid and docosahexaenoic acid  

Microsoft Academic Search

Arachidonic acid (ARA) and docosahexaenoic acid (DHA) are important in human brain and retina development, and there is growing evidence showing the importance of these fatty acids in infant nutrition. Triglyceride oils, highly enriched in ARA (ARASCO®) and DHA (DHASCO®), were evaluated using very high dose acute (20 g\\/kg) and 4-wk subchronic gavage feedings in weanling Sprague-Dawley rats. The combination

K. Boswell; E.-K. Koskelo; L. Carl; S. Glaza; D. J. Hensen; K. D. Williams; D. J. Kyle

1996-01-01

394

Modulation of arachidonate and docosahexaenoate in Morone chrysops larval tissues and the effect on growth and survival  

Microsoft Academic Search

The extent to which extreme dietary levels of arachidonate (AA) and\\/pr docosahexaenoate (DHA) modulate lipid composition in\\u000a the body tissues and consequently affect growth and survival in freshwater Morone larvae species was examined. White bass, M. chrysops, larvae (day 24–46) were fed Artemia nauplii enriched with algal oils containing varying proportions of AA and DHA (from 0 to over 20%

Moti Harel; Eric Lund; Sonja Gavasso; Ryan Herbert

2000-01-01

395

Inhibition of phytoalexin synthesis in arachidonic Acid-stressed potato tissue by inhibitors of lipoxygenase and cyanide-resistant respiration.  

PubMed

Arachidonic acid-stressed potato tuber discs synthesized the phytoalexin rishitin. This synthesis was inhibited by salicylhydroxamic acid (SHAM), and to a lesser extent by tetraethylthiuram disulfide (disulfiram). Disulfiram was less effective apparently because it was inactivated in the tuber discs. Disulfiram and SHAM both inhibited cyanide-resistant respiration of whole potato discs and lipoxygenase extracted from these discs. When low disulfiram concentrations were used, the lipoxygenase inhibition was quickly overcome, again because the disulfiram apparently was inactivated by oxidation. PMID:16663078

Stelzig, D A; Allen, R D; Bhatia, S K

1983-07-01

396

Acute doxorubicin toxicity differentially alters cytochrome P450 expression and arachidonic acid metabolism in rat kidney and liver.  

PubMed

The use of doxorubicin (DOX) is limited by significant cardiotoxicity, nephrotoxicity, and hepatotoxicity. We have previously shown that DOX cardiotoxicity induces several cardiac cytochrome P450 (P450) enzymes with subsequent alteration in P450-mediated arachidonic acid metabolism. Therefore, in the current study, we investigated the effect of acute DOX toxicity on P450 expression and arachidonic acid metabolism in the kidney and liver of male Sprague-Dawley rats. Acute DOX toxicity was induced by a single intraperitoneal injection (15 mg/kg) of the drug. After 6 and 24 h, the kidneys and livers were harvested, and several P450 gene and protein expressions were determined by real-time polymerase chain reaction and Western blot analyses, respectively. Kidney and liver microsomal protein from control or DOX-treated rats was incubated with arachidonic acid, and its metabolites were determined by liquid chromatography-electron spray ionization-mass spectrometry. Our results showed that acute DOX toxicity caused an induction of CYP1B1 and CYP4A enzymes and an inhibition of CYP2B1 and CYP2C11 in both the kidney and liver. CYP2E1 was induced and soluble epoxide hydrolase (sEH) was inhibited in the kidney only. In addition, DOX toxicity caused a significant increase in epoxyeicosatrienoic acids formation in the kidney and a significant increase in 20-hydroxyeicosatetraenoic acid formation in both the kidney and the liver. In conclusion, acute DOX toxicity alters the expression of several P450 and sEH enzymes in an organ-specific manner. These changes can be attributed to DOX-induced inflammation and resulted in altered P450-mediated arachidonic acid metabolism. PMID:21571947

Zordoky, Beshay N M; Anwar-Mohamed, Anwar; Aboutabl, Mona E; El-Kadi, Ayman O S

2011-08-01

397

Kinetic analysis of oil biosynthesis by an arachidonic acid-producing fungus, Mortierella alpina 1S-4  

Microsoft Academic Search

Kinetic analysis of arachidonic acid (AA)-oil biosynthesis by Mortierella alpina 1S-4 growing under lipid-accumulating (LN medium) and non-lipid-accumulating (HN medium) conditions was investigated and\\u000a compared with industrial AA fermentation. Various kinetic parameters of these cultivation processes demonstrate a characteristic\\u000a pattern of the lipogenesis in this fungus, where growth phase, phase of oil accumulation and phase of AA synthesis are distinct

M. Certik; S. Shimizu

2000-01-01

398

Improvement of arachidonic acid production by mutants with lower n-3 desaturation activity derived from Mortierella alpina 1S-4  

Microsoft Academic Search

Five mutants were obtained, Y11, Y135, Y164, Y180 and Y61, capable of accumulating higher amounts of arachidonic acid (AA) than Mortierella alpina 1S-4, an industrial strain for the production of AA-rich triacylglycerol (TG). This is thought to be due to low or no activity of n-3 desaturation with conversion of AA to eicosapentaenoic acid, which functions at a cultural temperature

Eiji Sakuradani; Yuriko Hirano; Nozomu Kamada; Masutoshi Nojiri; Jun Ogawa; Sakayu Shimizu

2004-01-01

399

A novel fungal ?3-desaturase with wide substrate specificity from arachidonic acid-producing Mortierella alpina 1S-4  

Microsoft Academic Search

A filamentous fungus, Mortierella alpina 1S-4, is capable of producing not only arachidonic acid (AA; 20:4 n-6) but also eicosapentaenoic acid (EPA; 20:5 n-3) below a cultural temperature of 20°C. Here, we describe the isolation and characterization of a gene ( maw3) that encodes a novel ?3-desaturase from M. alpina 1S-4. Based on the conserved sequence information for M. alpina

Eiji Sakuradani; Takahiro Abe; Keita Iguchi; Sakayu Shimizu

2005-01-01

400

Functional analysis of a fatty acid elongase from arachidonic acid-producing Mortierella alpina 1S-4  

Microsoft Academic Search

We describe the isolation and characterization of a gene (MAELO) that encodes a fatty acid elongase from arachidonic acid-producing fungus Mortierella alpina 1S-4. Although the homologous MAELO gene had already been isolated from M. alpina ATCC 32221, its function had not yet been identified. The MAELO gene from M. alpina 1S-4 was confirmed to encode a fatty acid elongase by

Eiji Sakuradani; Shoichi Murata; Hiroyuki Kanamaru; Sakayu Shimizu

2008-01-01

401

Arachidonic acid signaling is involved in the mechanism of imidazoline-induced KATP channel-independent stimulation of insulin secretion.  

PubMed

The mechanism by which the novel, pure glucose-dependent insulinotropic, imidazoline derivative BL11282 promotes insulin secretion in pancreatic islets has been investigated. The roles of KATP channels, alpha2-adrenoreceptors, the I1-receptor-phosphatidylcholine-specific phospholipase (PC-PLC) pathway and arachidonic acid signaling in BL11282 potentiation of insulin secretion in pancreatic islets were studied. Using SUR1(-/-) deficient mice, the previous notion that the insulinotropic activity of BL11282 is not related to its interaction with KATP channels was confirmed. Insulinotropic activity of BL11282 was not related to its effect on alpha2-adrenoreceptors, I1-imidazoline receptors or PC-PLC. BL11282 significantly increased [3H]arachidonic acid production. This effect was abolished in the presence of the iPLA2 inhibitor, bromoenol lactone. The data suggest that potentiation of glucose-induced insulin release by BL11282, which is independent of concomitant changes in cytoplasmic free Ca2+ concentration, involves release of arachidonic acid by iPLA2 and its metabolism to epoxyeicosatrienoic acids through the cytochrome P-450 pathway. PMID:17922229

Sharoyko, V V; Zaitseva, I I; Leibiger, B; Efendi?, S; Berggren, P O; Zaitsev, S V

2007-11-01

402

Chronic cigarette smoke exposure adversely alters /sup 14/C-arachidonic acid metabolism in rat lungs, aortas and platelets  

SciTech Connect

Male rats were exposed to freshly generated cigarette smoke once daily, 5 times a week for 10 weeks. Inhalation of smoke was verified by elevated carboxyhemoglobin in blood sampled immediately after smoke exposure and by increased lung aryl hydrocarbon hydroxylase activity 24 hours after the last smoke exposure. Aortic rings isolated from smoke-exposed rats synthesized less prostacyclin (PGI2) from /sup 14/C-arachidonic acid than rings from sham rats. Platelets from smoke-exposed rats synthesized more thromboxane (TXA2) from /sup 14/C-arachidonic acid than platelets from room controls but not those from sham rats. Lung microsomes from smoke-exposed rats synthesized more TXA2 and had a lower PGI2/TXA2 ratio than lung microsomes from room controls and shams. It is concluded that chronic cigarette smoke exposure alters arachidonic acid metabolism in aortas, platelets and lungs in a manner resulting in decreased PGI2 and increased TXA2, thereby creating a condition favoring platelet aggregation and a variety of cardiovascular diseases.

Lubawy, W.C.; Valentovic, M.A.; Atkinson, J.E.; Gairola, G.C.

1983-08-08

403

Arachidonic acid and prostaglandin endoperoxide metabolism in isolated rabbit and coronary microvessels and isolated and cultivated coronary microvessel endothelial cells.  

PubMed Central

Isolated microvessels and isolated and cultured microvessel endothelial cells were prepared from rabbit cardiac muscle. Pathways of arachidonic acid metabolism were determined by measurement of exogenous substrate utilization [( 1-14C]arachidonic acid incorporation and release from intact tissue and cells; [1-14C]prostaglandin H2 (PGH2) metabolism by broken cell preparations) and by quantification of endogenous products (immunoreactive 6-keto-prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E (PGE) release) by selective radioimmunoassay. Rabbit coronary microvessels and derived microvascular endothelial cells (RCME cells) synthesized two major products of the cyclooxygenase pathway: 6-keto-PGF1 alpha (hydrolytic product of prostaglandin I2) and PGE2. A reduced glutathione requiring PGH-E isomerase was demonstrated in coronary microvessels and RCME cells, but not in rabbit circumflex coronary artery or aorta. In addition, a minor amount of a compound exhibiting similar characteristics to 6-keto-PGE1 was found to be produced by microvessels and RCME cells. Measurement of endogenously released prostaglandins indicated that under basal and stimulated conditions, PGE release exceeded that of 6-keto-PGF1 alpha. Microvessels and microvessel endothelial cells derived from cardiac muscle of rabbit exhibit pathways of arachidonate metabolism that are different from those of many large blood vessels and derived endothelial cells. Images PMID:6415116

Gerritsen, M E; Cheli, C D

1983-01-01

404

Transformation of oil-producing fungus, Mortierella alpina 1S-4, using Zeocin, and application to arachidonic acid production.  

PubMed

The arachidonic acid-producing fungus Mortierella alpina 1S-4, an industrial strain, was endowed with Zeocin resistance by integration of the Zeocin-resistance gene at the rDNA locus of genomic DNA. Plasmid DNA was introduced into spores by microprojectile bombardment. Twenty mg/ml Zeocin completely inhibited the germination of M. alpina 1S-4 spores, and decreased the growth rate of fungal filaments to some extent. It was suggested that preincubation period and temperature had a great influence on transformation efficiency. Four out of 26 isolated transformants were selected. Molecular analysis of these stable transformants showed that the plasmid DNA was integrated into the rDNA locus of the genomic DNA. We expect that this system will be applied for useful oil production by gene manipulation of M. alpina 1S-4 and its derivative mutants. On the basis of the fundamental transformation system, we also tried to overexpress a homologous polyunsaturated fatty acid elongase gene, which has been reported to be included in the rate-limiting step for arachidonic acid production, thereby leading to increased arachidonic acid production. PMID:16473770

Takeno, Seiki; Sakuradani, Eiji; Tomi, Akiko; Inohara-Ochiai, Misa; Kawashima, Hiroshi; Shimizu, Sakayu

2005-12-01

405

Human Action Recognition Using Wireless Wearable In-Ear Microphone  

NASA Astrophysics Data System (ADS)

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.

Nishimura, Jun; Kuroda, Tadahiro

406

Influences on clinical practice: the case of glue ear  

PubMed Central

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

Dopson, S.; Miller, R.; Dawson, S.; Sutherland, K.

1999-01-01

407

A Ubiquitous Blood Pressure Sensor Worn at the Ear  

NASA Astrophysics Data System (ADS)

Blood pressure (BP) measurement and BP control are important for the prevention of lifestyle diseases, especially hypertension, which can lead to more serious conditions, such as cardiac infarction and cerebral apoplexy. The purpose of our study is to develop a ubiquitous blood pressure sensor that is more comfortable and less disruptive of users' daily activities than conventional blood pressure sensors. Our developed sensor is worn at an ear orifice and measures blood pressure at the tragus. This paper describes the concept, configuration, and the optical and electronic details of the developed ear-worn blood pressure sensor and presents preliminary evaluation results. The developed sensor causes almost no discomfort and produces signals whose quality is high enough for detecting BP at an ear, making it suitable for ubiquitous usage.

Koizumi, Hiroshi; Shimada, Junichi; Uenishi, Yuji; Tochikubo, Osamu

2009-12-01

408

Sensory Cells of the Fish Ear: A Hairy Enigma  

NASA Technical Reports Server (NTRS)

Analysis of the structure of the ears in teleost fishes has led to the tentative suggestion that otolithic endorgans may function differently, in different species. Recently, evidence has demonstrated different 'types' of sensory hair cells can be found in the ears of teleost fishes, and individual hair cell types are found in discrete regions of individual sensory, epithelia. The presence of multiple hair cell types in fishes provides strong support to the hypothesis of regional differences in the responses of individual otolithic sensory epithelia. The finding of hair cell types in fishes that closely resemble those found in amniote vestibular endorgans also suggests that hair cell heterogeneity arose earlier in the evolution of the vertebrate ear than previously thought.

Popper, A. N.; Saidel, W. M.

1995-01-01

409

Characterization of an arachidonic acid-deficient (Fads1 knockout) mouse model.  

PubMed

Arachidonic acid (20:4(?5,8,11,14), AA)-derived eicosanoids regulate inflammation and promote cancer development. Previous studies have targeted prostaglandin enzymes in an attempt to modulate AA metabolism. However, due to safety concerns surrounding the use of pharmaceutical agents designed to target Ptgs2 (cyclooxygenase 2) and its downstream targets, it is important to identify new targets upstream of Ptgs2. Therefore, we determined the utility of antagonizing tissue AA levels as a novel approach to suppressing AA-derived eicosanoids. Systemic disruption of the Fads1 (?5 desaturase) gene reciprocally altered the levels of dihomo-?-linolenic acid (20:3(?8,11,14), DGLA) and AA in mouse tissues, resulting in a profound increase in 1-series-derived and a concurrent decrease in 2-series-derived prostaglandins. The lack of AA-derived eicosanoids, e.g., PGE? was associated with perturbed intestinal crypt proliferation, immune cell homeostasis, and a heightened sensitivity to acute inflammatory challenge. In addition, null mice failed to thrive, dying off by 12 weeks of age. Dietary supplementation with AA extended the longevity of null mice to levels comparable to wild-type mice. We propose that this new mouse model will expand our understanding of how AA and its metabolites mediate inflammation and promote malignant transformation, with the eventual goal of identifying new drug targets upstream of Ptgs2. PMID:22534642

Fan, Yang-Yi; Monk, Jennifer M; Hou, Tim Y; Callway, Evelyn; Vincent, Logan; Weeks, Brad; Yang, Peiying; Chapkin, Robert S

2012-07-01

410

IMAGING BRAIN SIGNAL TRANSDUCTION AND METABOLISM VIA ARACHIDONIC AND DOCOSAHEXAENOIC ACID IN ANIMALS AND HUMANS  

PubMed Central

The polyunsaturated fatty acids (PUFAs), arachidonic acid (AA, 20:4n-6) and docosahexaenoic acid (DHA, 22:6n-3), important second messengers in brain, are released from membrane phospholipid following receptor-mediated activation of specific phospholipase A2 (PLA2) enzymes. We developed an in vivo method in rodents using quantitative autoradiography to image PUFA incorporation into brain from plasma, and showed that their incorporation rates equal their rates of metabolic consumption by brain. Thus, quantitative imaging of unesterified plasma AA or DHA incorporation into brain can be used as a biomarker of brain PUFA metabolism and neurotransmission. We have employed our method to image and quantify effects of mood stabilizers on brain AA/DHA incorporation during neurotransmission by muscarinic M1,3,5, serotonergic 5-HT2A/2C, dopaminergic D2-like (D2, D3, D4) or glutamatergic N-methyl-D-aspartic acid (NMDA) receptors, and effects of inhibition of acetylcholinesterase, of selective serotonin and dopamine reuptake transporter inhibitors, of neuroinflammation (HIV-1 and lipopolysaccharide) and excitotoxicity, and in genetically modified rodents. The method has been extended for the use with positron emission tomography (PET), and can be employed to determine how human brain AA/DHA signaling and consumption are influenced by diet, aging, disease and genetics. PMID:22178644

Basselin, Mireille; Ramadan, Epolia; Rapoport, Stanley I.

2012-01-01

411

Chronic olanzapine treatment decreases arachidonic acid turnover and prostaglandin E2 concentration in rat brain  

PubMed Central

Olanzapine (OLZ) is used to treat bipolar disorder, but its therapeutic mechanism of action is not clear. Arachidonic acid (AA, 20:4n-6) plays a critical role in brain signaling and an upregulated AA metabolic cascade was reported in postmortem brains from bipolar disorder patients. Here we tested whether, similar to the action of the mood stabilizers lithium, carbamazepine and valproate, chronic OLZ treatment would reduce AA turnover in rat brain. We administered OLZ (6 mg/kg/day) or vehicle i.p. to male rats once daily for 21 days. A washout group received 21 days of OLZ followed by vehicle on day 22. Two hours after the last injection, [1-14C]AA (170 µCi/kg) was infused intravenously for 5 min, and timed arterial blood samples were taken. After the rat was euthanized at 5 min, its brain was microwaved, removed and analyzed. Chronic OLZ decreased plasma unesterified AA concentration, AA incorporation rates and AA turnover in brain phospholipids. These effects were absent after washout. Consistent with reduced AA turnover, OLZ decreased brain cyclooxygenase activity and the brain concentration of the proinflammatory AA-derived metabolite, prostaglandin E2. In view of upregulated brain AA metabolic markers in bipolar disorder, the abilities of OLZ and the mood stabilizers to commonly decrease prostaglandin E2 and AA turnover in rat brain phospholipids, albeit by different mechanisms, may be related to their efficacy against the disease. PMID:21812779

Cheon, Yewon; Park, Jee-Young; Modi, Hiren R.; Kim, Hyung-Wook; Lee, Ho-Joo; Chang, Lisa; Rao, Jagadeesh S.; Rapoport, Stanley I.

2011-01-01

412

Phospholipase activation and arachidonic acid release in cultured intestinal epithelial cells (INT 407).  

PubMed

The release of free arachidonic acid (AA) in cultured intestinal epithelial cells (INT 407) was investigated. INT-407 cells were first incubated overnight with radiolabeled 14C-AA, and most of the incorporated 14C-AA esterified into phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol. Labeled cells were then exposed to different stimulating agents and the release of free 14C-AA determined. The calcium ionophore A23187 caused a dose-dependent AA release that was preceded by a rapid uptake and a subsequent efflux of 45Ca2+. By contrast, phospholipase C from Clostridium perfringens caused a great AA release that was accompanied by an apparent uptake and a sustained intracellular accumulation of 45Ca2+. The cells alos released AA when exposed to the protein kinase C activator, 4 beta-phorbol-12-myristate-13-acetate (PMA), and this agent, like the diacylglycerol 1-oleoyl-2-acetyl-rac-glycerol, significantly potentiated the AA release caused by A23187. Not only A23187-mediated but also phospholipase C- and PMA-mediated AA release was inhibited by 4-bromophenacyl bromide, a known phospholipase A2 inhibitor. These findings, taken together, indicate that AA release in intestinal epithelial cells can be caused by (i) Ca2+-mediated phospholipase activation, (ii) products of phospholipase C activity, and (iii) stimulation of protein kinase C. It is suggested, therefore, that AA release in intestinal epithelial cells is governed by intracellular Ca2+, protein kinase C-mediated protein phosphorylation, and activation of phospholipase A2. PMID:2506636

Gustafson, C; Tagesson, C

1989-05-01

413

Brain arachidonic and docosahexaenoic acid cascades are selectively altered by drugs, diet and disease.  

PubMed

Metabolic cascades involving arachidonic acid (AA) and docosahexaenoic acid (DHA) within brain can be independently targeted by drugs, diet and pathological conditions. Thus, AA turnover and brain expression of AA-selective cytosolic phospholipase A(2) (cPLA(2)), but not DHA turnover or expression of DHA-selective Ca(2+)-independent iPLA(2), are reduced in rats given agents effective against bipolar disorder mania, whereas experimental excitotoxicity and neuroinflammation selectively increase brain AA metabolism. Furthermore, the brain AA and DHA cascades are altered reciprocally by dietary n-3 polyunsaturated fatty acid (PUFA) deprivation in rats. DHA loss from brain is slowed and iPLA(2) expression is decreased, whereas cPLA(2) and COX-2 are upregulated, as are brain concentrations of AA and its elongation product, docosapentaenoic acid (DPA). Positron emission tomography (PET) has shown that the normal human brain consumes 17.8 and 4.6 mg/day, respectively, of AA and DHA, and that brain AA consumption is increased in Alzheimer disease patients. In the future, PET could help to determine how human brain AA or DHA consumption is influenced by diet, aging or disease. PMID:18973997

Rapoport, Stanley I

2008-01-01

414

Anti-inflammatory activity and inhibition of arachidonic acid metabolism by flavonoids.  

PubMed

A group of flavonoids isolated from medicinal plants and which are selective inhibitors of lipoxygenase activity in vitro: sideritoflavone, cirsiliol, hypolaetin-8-O-beta-D-glucoside, hypolaetin, oroxindin, quercetagetin-7-O-beta-D-glucoside, gossypin, hibifolin and gossypetin, besides leucocyanidol, have been studied for their effects on acute responses induced by carrageenin in mice. The oral administration of flavonoids to mice inhibited dose-dependently the development of paw oedema at 1, 3 and 5 h after carrageenin injection. A similar administration of flavonoids induced a dose-dependent inhibition of leukocyte accumulation in inflammatory exudates following intraperitoneal injection of carrageenin into mice. Some of the flavonoids exhibited a potency against leukocyte infiltration similar to that seen for inhibition of carrageenin oedema at 3 h of induction. In agreement with data reported in rats, indomethacin was much more effective on inhibition of prostaglandin E2 (PGE2) formation than on leukocyte infiltration in mice. The selectivity of flavonoids towards lipoxygenase is not retained in vivo since they behave as dual inhibitors of PGE2 and leukotriene B4 (LTB4) formation in peritoneal exudates. Our data support the inhibition of arachidonic acid metabolism as one of the mechanisms by which flavonoids exert their anti-inflammatory effects. PMID:1650522

Ferrándiz, M L; Alcaraz, M J

1991-03-01

415

Chronic carbamazepine administration reduces NMDA receptor-initiated signaling via arachidonic acid in rat brain  

PubMed Central

Background Lithium and carbamazepine (CBZ) are used to treat mania in bipolar disorder. When given chronically to rats, both agents reduce brain arachidonic acid (AA) turnover in brain phospholipids and downstream AA metabolism. Lithium administration to rats also attenuates N-methyl-D-aspartic acid receptor (NMDAR) signaling via AA. Hypothesis Chronic CBZ administration to rats, like chronic lithium, will reduce NMDAR-mediated signaling via AA. Methods We used our fatty acid method with quantitative autoradiography to image the regional brain incorporation coefficient k* of AA, a marker of AA signaling, in unanesthetized rats that had been given 25 mg/kg/day i.p. CBZ or vehicle for 30 days, then injected with NMDA (25 mg/kg i.p.) or saline. We also measured brain concentration of two AA metabolites, prostaglandin E2 (PGE2) and thromboxane B2 (TXB2). Results In chronic vehicle-treated rats, NMDA compared with saline increased k* significantly in 69 of 82 brain regions examined, but did not change k* significantly in any region in the CBZ-treated rats. In vehicle- but not CBZ-treated rats, NMDA also increased brain concentration of PGE2 and TXB2. Conclusions Chronic CBZ administration to rats blocks the brain NMDAR-mediated AA signal k* and the increments in PGE2 and TXB2 that are seen in vehicle-treated rats. The clinical action of antimanic drugs may involve inhibition of brain NMDAR-mediated signaling involving AA and its metabolites. PMID:17628508

Basselin, Mireille; Villacreses, Nelly E.; Chen, Mei; Bell, Jane M.; Rapoport, Stanley I.

2007-01-01

416

Chronic administration of valproic acid reduces brain NMDA signaling via arachidonic acid in unanesthetized rats  

PubMed Central

Evidence that brain glutamatergic activity is pathologically elevated in bipolar disorder suggests that mood stabilizers are therapeutic in the disease in part by downregulating glutamatergic activity. Such activity can involve the second messenger, arachidonic acid (AA, 20:4n-6). We tested this hypothesis with regard to valproic acid (VPA), when stimulating glutamatergic N-methyl-D-aspartate (NMDA) receptors in rat brain and measuring AA and related responses. An acute subconvulsant dose of NMDA (25 mg/kg i.p.) or saline was administered to unanesthetized rats that had been treated i.p. daily with VPA (200 mg/kg) or vehicle for 30 days. Quantitative autoradiography following intravenous [1-14C]AA infusion was used to image regional brain AA incorporation coefficients k*, markers of AA signaling. In chronic vehicle-pretreated rats, NMDA compared with saline significantly increased k* in 41 of 82 examined brain regions, many of which have high NMDA receptor densities, and also increased brain concentrations of the AA metabolites, prostaglandin E2 (PGE2) and thromboxane B2 (TXB2). VPA pretreatment reduced baseline concentrations of PGE2 and TXB2, and blocked the NMDA induced increases in k* and in eicosanoid concentrations. These results, taken with evidence that carbamazepine and lithium also block k* responses to NMDA in rat brain, suggest that mood stabilizers act in bipolar disorder in part by downregulating glutamatergic signaling involving AA. PMID:18461450

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

2008-01-01

417

Calcium influx is required for tannin-mediated arachidonic acid release from alveolar macrophages.  

PubMed

The role of Ca2+ was investigated in the response of alveolar macrophages to cotton tannin, an agent implicated in the lung disease byssinosis in textile mill workers. A physiological concentration of extracellular Ca2+ was found to be required for tannin-mediated release of radiolabeled arachidonic acid (AA). Flow cytometry using indo 1 indicated that tannin caused a rapid and dose-dependent Ca2+ increase in macrophages that also required extracellular Ca2+. Ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid virtually abolished the Ca2+ influx mediated by tannin but had little effect on intracellular Ca2+ release induced by thapsigargin, N-formylmethionyl-leucylphenylalanine, or thimerosal. A mechanism for extracellular Ca2+ influx was demonstrated by rapid Mn2+ quenching of indo 1 by tannin. Verapamil inhibited tannin-mediated Ca2+ influx and AA release, but the effective concentration was 100 microM. 1,2-Bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid chelated all Ca2+ in the cells and effectively abolished the tannin response. Exposure to tannin was not associated with cytotoxicity, as judged by 51Cr release. The data suggest that tannin induces Ca2+ influx in alveolar macrophages, which represents an important prerequisite for a cell-signaling pathway resulting in the accumulation of free AA. PMID:7840226

Bates, P J; Ralston, N V; Vuk-Pavlovi?, Z; Rohrbach, M S

1995-01-01

418

The utility of 11C-arachidonate PET to study in vivo dopaminergic neurotransmission in humans  

PubMed Central

We developed a novel method to study dopaminergic neurotransmission using positron emission tomography (PET) with [1-11C]arachidonic acid ([1-11C]AA). Previous preclinical studies have shown the utility of [1-11C]AA as a marker of signal transduction coupled to cytosolic phospholipase A2 (cPLA2). Using [1-11C]AA and [15O]water PET, we measured regional incorporation coefficients K* for AA and regional cerebral blood flow (rCBF), respectively, in healthy male volunteers given the D1/D2 agonist (10 or 20??g/kg subcutaneous) apomorphine. We confirmed a robust central dopaminergic response to apomorphine by observing significant increases in the serum concentration of growth hormone. We observed significant increases, as well as decreases in K* and increases in rCBF in response to apomorphine. These changes remained significant after covarying for handedness and apomorphine dosage. The magnitude of increases in K* was lower than those in our previous animal experiments, likely reflecting the smaller dose of apomorphine used in the current human study. Changes in K* may reflect neuronal signaling downstream of activated D2-like receptors coupled to cPLA2. Changes in rCBF are consistent with previous studies showing net functional effects of D1/D2 activation. [1-11C]AA PET may be useful for studying disturbances of dopaminergic neurotransmission in conditions such as Parkinson's disease and schizophrenia. PMID:22167235

Thambisetty, Madhav; Gallardo, Kathy A; Liow, Jeih-San; Beason-Held, Lori L; Umhau, John C; Bhattacharjee, Abesh K; Der, Margaret; Herscovitch, Peter; Rapoport, Judith L; Rapoport, Stanley I

2012-01-01

419

Intestinal zinc transport: influence of streptozotocin-induced diabetes, insulin and arachidonic acid  

SciTech Connect

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.

Song, M.K.; Mooradian, A.D.

1988-01-01

420

LPIAT1 regulates arachidonic acid content in phosphatidylinositol and is required for cortical lamination in mice  

PubMed Central

Dietary arachidonic acid (AA) has roles in growth, neuronal development, and cognitive function in infants. AA is remarkably enriched in phosphatidylinositol (PI), an important constituent of biological membranes in mammals; however, the physiological significance of AA-containing PI remains unknown. In an RNA interference–based genetic screen using Caenorhabditis elegans, we recently cloned mboa-7 as an acyltransferase that selectively incorporates AA into PI. Here we show that lysophosphatidylinositol acyltransferase 1 (LPIAT1, also known as MBOAT7), the closest mammalian homologue, plays a crucial role in brain development in mice. Lpiat1?/? mice show almost no LPIAT activity with arachidonoyl-CoA as an acyl donor and show reduced AA contents in PI and PI phosphates. Lpiat1?/? mice die within a month and show atrophy of the cerebral cortex and hippocampus. Immunohistochemical analysis reveals disordered cortical lamination and delayed neuronal migration in the cortex of E18.5 Lpiat1?/? mice. LPIAT1 deficiency also causes disordered neuronal processes in the cortex and reduced neurite outgrowth in vitro. Taken together, these results demonstrate that AA-containing PI/PI phosphates play an important role in normal cortical lamination during brain development in mice. PMID:23097495

Lee, Hyeon-Cheol; Inoue, Takao; Sasaki, Junko; Kubo, Takuya; Matsuda, Shinji; Nakasaki, Yasuko; Hattori, Mitsuharu; Tanaka, Fumiharu; Udagawa, Osamu; Kono, Nozomu; Itoh, Toshiki; Ogiso, Hideo; Taguchi, Ryo; Arita, Makoto; Sasaki, Takehiko; Arai, Hiroyuki

2012-01-01

421

Changes in cardiovascular sensitivity of alloxan-treated diabetic rats to arachidonic acid.  

PubMed Central

Arachidonic acid (AA, 0.125-2.0 mg kg-1) administered intravenously to male Wistar rats produced a dose-dependent fall in diastolic blood pressure. However AA (0.125-1.0 mg kg-1) injected into the autoperfused hindquarters via the aorta produced a dose-dependent increase in perfusion pressure. Both these responses to AA were inhibited by indomethacin (5 mg kg-1). The thromboxane A2 receptor antagonist AH23848 (5 mg kg-1, i.v.) inhibited pressor responses to AA in the autoperfused hindquarters, but potentiated depressor responses to AA (0.125-0.5 mg kg-1) in the whole animal. Alloxan-treated diabetic rats (14 days after a single s.c. injection of alloxan, 175 mg kg-1) displayed reduced sensitivity to the depressor effects of AA (1-2 mg kg-1) in the whole animal, increased sensitivity to the pressor effects of AA (0.5-1.0 mg kg-1) in the perfused hindquarters, and reduced sensitivity to the pressor effects of the thromboxane A2 mimetic U46619 (0.5-8.0 micrograms kg-1, i.a.) in the perfused hindquarters. These results suggest that AA can be predominantly converted to either pressor or depressor metabolites depending on the vasculature. In the diabetic state the ratio of the metabolites formed appears to change favouring a major pressor metabolite, which is probably thromboxane A2. PMID:3099877

Boura, A. L.; Hodgson, W. C.; King, R. G.

1986-01-01

422

Role of arachidonic acid, lipoxygenase, and mitochondrial depolarization in reperfusion arrhythmias.  

PubMed

We have sought evidence that arachidonic acid (AA) induces mitochondrial depolarization in isolated myocytes by a lipoxygenase (LOX)-dependent mechanism and that such depolarization might contribute to arrhythmogenesis following ischemia-reperfusion injury. A method was developed for measuring mitochondrial depolarization in isolated adult rat myocytes in suspension, using tetramethylrhodamine ethyl ester. The addition of AA to myocytes resulted in mitochondrial depolarization that was inhibited by the LOX inhibitor baicalein, by the reactive oxygen species (ROS) scavenger mercaptoproprionylglycine, and by the anion channel inhibitor diisothiocyanatostilbene-disulfonic acid (DIDS). AA induced mitochondrial uncoupling and mitochondrial ATPase activity in myocytes, but both were insensitive to baicalein. We conclude that the metabolic effect of AA in myocytes puts mitochondria into an energetically compromised state where membrane potential is easily changed by the DIDS-sensitive LOX/ROS-mediated opening of an inner membrane anion channel. In an in vivo anesthetized rat model of coronary artery occlusion, baicalein was found to strongly inhibit arrhythmias induced by ischemia-reperfusion injury. Arrhythmias following ischemia-reperfusion injury have been previously associated with DIDS-sensitive ROS-mediated mitochondrial depolarization, and free fatty acids including AA were previously found to accumulate during such injury. We therefore conclude that arrhythmias following ischemia-reperfusion injury might originate from mitochondrial depolarization mediated by LOX and AA. PMID:20435853

Haworth, Robert A; Potter, Katherine T; Russell, Douglas C

2010-07-01

423

Characterization of Novel Radicals from COX-Catalyzed Arachidonic Acid Peroxidation  

PubMed Central

The peroxidation of arachidonic acid (AA) catalyzed by cyclooxygenase (COX) is a well known free radical-mediated process that forms many bioactive products. Due to a lack of appropriate methodologies, however, no comprehensive structural evidence has been found previously for the formation of COX-mediated and AA-derived free radicals. Here we have used a combination of LC/ESR and LC/MS with a spin trap, ?-[4-pyridyl-1-oxide]-N-tert-butyl nitrone (POBN), to characterize the carbon-centered radicals formed from COX-catalyzed AA peroxidation in vitro, including cellular peroxidation in human prostate cancer cells (PC-3). Three types of radicals with numerous isomers were trapped by POBN as ESR-active peaks and MS-active ions of m/z 296, m/z 448, and m/z 548, all stemming from PGF2-type alkoxyl radicals. One of these was a novel radical centered on the carbon-carbon double bond nearest the PGF ring, caused by an unusual ?-scission of PGF2-type alkoxyl radicals. The complementary non-radical product was 1-hexanol, another novel ?-scission product, instead of the more common aldehyde. The characterization of these novel products formed from in vitro peroxidation provides a new mechanistic insight into COX-catalyzed AA peroxidation in cancer biology. PMID:19482075

Yu, Qingfeng; Purwaha, Preeti; Ni, Kunyi; Sun, Chengwen; Mallik, Sanku; Qian, Steven Y.

2009-01-01

424

Arachidonic acid-dependent gene regulation during preadipocyte differentiation controls adipocyte potential[S  

PubMed Central

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

Nikolopoulou, Evanthia; Papacleovoulou, Georgia; Jean-Alphonse, Frederic; Grimaldi, Giulia; Parker, Malcolm G.; Hanyaloglu, Aylin C.; Christian, Mark

2014-01-01

425

Cell survival signalling through PPAR? and arachidonic acid metabolites in neuroblastoma.  

PubMed

Retinoic acid (RA) has paradoxical effects on cancer cells: promoting cell death, differentiation and cell cycle arrest, or cell survival and proliferation. Arachidonic acid (AA) release occurs in response to RA treatment and, therefore, AA and its downstream metabolites may be involved in cell survival signalling. To test this, we inhibited phospholipase A2-mediated AA release, cyclooxygenases and lipoxygenases with small-molecule inhibitors to determine if this would sensitise cells to cell death after RA treatment. The data suggest that, in response to RA, phospholipase A2-mediated release of AA and subsequent metabolism by lipoxygenases is important for cell survival. Evidence from gene expression reporter assays and PPAR? knockdown suggests that lipoxygenase metabolites activate PPAR?. The involvement of PPAR? in cell survival is supported by results of experiments with the PPAR? inhibitor GSK0660 and siRNA-mediated knockdown. Quantitative reverse transcriptase PCR studies demonstrated that inhibition of 5-lipoxygenase after RA treatment resulted in a strong up-regulation of mRNA for PPAR?2, a putative inhibitory PPAR? isoform. Over-expression of PPAR?2 using a tetracycline-inducible system in neuroblastoma cells reduced proliferation and induced cell death. These data provide evidence linking lipoxygenases and PPAR? in a cell survival-signalling mechanism and suggest new drug-development targets for malignant and hyper-proliferative diseases. PMID:23874790

Bell, Emma; Ponthan, Frida; Whitworth, Claire; Westermann, Frank; Thomas, Huw; Redfern, Christopher P F

2013-01-01

426

Pharmacological manipulation of arachidonic acid-epoxygenase results in divergent effects on renal damage  

PubMed Central

Kidney damage is markedly accelerated by high-salt (HS) intake in stroke-prone spontaneously hypertensive rats (SHRSP). Epoxyeicosatrienoic acids (EETs) are epoxygenase products of arachidonic acid which possess vasodepressor, natriuretic, and anti-inflammatory activities. We examined whether up-regulation (clofibrate) or inhibition [N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide (MS-PPOH)] of epoxygenase would alter systolic blood pressure (SBP) and/or renal pathology in SHRSP on HS intake (1% NaCl drinking solution). Three weeks of treatment with clofibrate induced renal cortical protein expression of CYP2C23 and increased urinary excretion of EETs compared with vehicle-treated SHRSP. SBP and urinary protein excretion (UPE) were significantly lowered with clofibrate treatment. Kidneys from vehicle-treated SHRSP, which were on HS intake for 3 weeks, demonstrated focal lesions of vascular fibrinoid degeneration, which were markedly attenuated with clofibrate treatment. In contrast, 2 weeks of treatment with the selective epoxygenase inhibitor, MS-PPOH, increased UPE without significantly altering neither urinary EET levels nor SBP. Kidneys from vehicle-treated SHRSP, which were on HS intake for 11 days, demonstrated occasional mild damage whereas kidneys from MS-PPOH-treated rats exhibited widespread malignant nephrosclerosis. These results suggest that pharmacological manipulation of epoxygenase results in divergent effects on renal damage and that interventions to increase EET levels may provide therapeutic strategies for treating salt-sensitive hypertension and renal damage.

Li, Jing; Stier, Charles T.; Chander, Praveen N.; Manthati, Vijay L.; Falck, John R.; Carroll, Mairead A.

2014-01-01

427

Arachidonic acid-rich oil production by Mortierella alpina with different gas distributors.  

PubMed

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

Nie, Zhi-Kui; Ji, Xiao-Jun; Shang, Jing-Sheng; Zhang, Ai-Hui; Ren, Lu-Jing; Huang, He

2014-06-01

428

Development of a defined medium for arachidonic acid production by Mortierella alpina using a visualization method.  

PubMed

Defined medium for arachidonic acid (ARA) production by Mortierella alpina was optimized for its metabolomics study. For this purpose, a visualization method (VM) was applied for the first time. Experiments were designed according to the uniform design with four factors (concentrations of glucose, NaNO(3), KH(2)PO(4) and MgSO(4)·7H(2)O) for each at nine levels. Dry cell weight (DCW), ARA yield in DCW [percent (w/w)] and ARA content in total fatty acids [percent (w/w)] were considered as the three objectives. Optimization of single-objective function and multi-objective function of two objectives and three objectives was attempted. Optimal DCW, ARA yield and ARA content were predicted to occur in a medium that contained (grams per litre): glucose 35, NaNO(3) 1, KH(2)PO(4) 7.5 and MgSO(4)·7H(2)O 2.6. Upon verification, the average tested DCW (12.95 g/l), ARA yield (18.89 %) and ARA content (42.36 %) were fairly close to the predicted values (12.88 g/l, 9.68 % and 35.57 %, respectively). Moreover, DCW, ARA yield and ARA content from the optimum medium increased by 35.68, 47.23 and 30.90 % compared with control, respectively, indicating that VM had succeeded in exploiting the biomass growth and ARA production by M. alpina. PMID:23054814

Liu, Xin; Ji, Xiaojun; Zhang, Hongman; Fu, Ninghua; Yan, Liexiang; Deng, Zhongtao; Huang, He

2012-11-01

429

Safety evaluation of arachidonic acid rich Mortierella alpina biomass in albino rats--a subchronic study.  

PubMed

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

Nisha, A; Muthukumar, S P; Venkateswaran, G

2009-04-01

430

Regulation of arachidonic acid in esophageal adenocarcinoma cells and tumor-infiltrating lymphocytes  

PubMed Central

The generation and development of esophageal adenocarcinoma (EAC) are correlated with neuroimmunological factors. The aim of this study was to observe the effectiveness of the neurotransmitter arachidonic acid (AA) on two EAC cell lines, OE19 and SK-GT-4, as well as three isolated tumor-infiltrating lymphocytes (TIL1, 2 and 3). C-X-C chemokine receptor type 4 (CXCR-4) and tumor necrosis factor receptor 1 (TNFR1) expression, cell migration, necrosis, cytokine secretion and cytotoxicity of TILs were investigated. AA dose-dependently increased the migration of all cells. However, AA did not increase the percentage of cell death of the three TILs in the presence of a necrosis-inducing agent. AA dose-dependently increased the cytotoxicity of the three ??T cell-enriched TILs compared with the OE19 and SK-GT-4 cell lines. AA also dose-dependently increased the secretion of interferon-? (IFN-?) and TNF-? in TIL1 and 2. However, the cytokine secretion and cytotoxicity activity of TIL3 and ??T cell-enriched TIL3 were the lowest. Furthermore, the percentage of CD4+forkhead box p3 (Foxp3)+ regulatory T cells in TIL3 was the highest. The effect of AA on tumor cells and TILs is different. The degree of malignancy of the tumor and the ratio of regulatory T cells may be the main factors determining the function of AA. PMID:23833663

SONG, WEI; JIANG, RUI; ZHAO, CHUNMING

2013-01-01

431

Arachidonic Acid: An Evolutionarily Conserved Signaling Molecule Modulates Plant Stress Signaling Networks[C][W  

PubMed Central

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

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

432

Altered macrophage arachidonic acid metabolism induced by endotoxin tolerance: characterization and mechanisms  

SciTech Connect

Altered macrophage arachidonic acid (AA) metabolism may play a role in endotoxic shock and the phenomenon of endotoxin tolerance induced by repeated injections of endotoxin. Studies were initiated to characterize both lipoxygenase and cyclooxygenase metabolite formation by endotoxin tolerant and non-tolerant macrophages in response to 4 different stimuli, i.e., endotoxin, glucan, zymosan, and the calcium ionophore A23187. In contrast to previous reports of decreased prostaglandin synthesis by tolerant macrophages, A23187-stimulated immunoreactive (i) leukotriene (LT) C/sub 4/D/sub 4/ and prostaglandin (PG) E/sub 2/ production by tolerant cells was greater than that by non-tolerant controls (p <0.001). However, A23187-stimulated i6-keto PGF/sub 1a/ levels were lower in tolerant macrophages compared to controls (P < 0.05). iL TC/sub 4/D/sub 4/ production was not significantly stimulated by endotoxin or glucan, but was stimulated by zymosan in non-tolerant cells. Synthesis of iLTB/sub 4/ by control macrophages was stimulated by endotoxin (p <0.01). The effect of tolerance on factors that affect AA release was investigated by measuring /sup 14/C-AA incorporation and release and phospholipase A/sub 2/ activity

Rogers, T.S.

1986-01-01

433

Murine middle ear inflammation and ion homeostasis gene expression  

PubMed Central

Hypothesis Ion homeostasis genes are responsible for movement of ions and water in the epithelium of the middle ear. Background It is not well known to what extent disruption of ion homeostasis is a factor in the accumulation of middle ear fluid during otitis media. Methods Balb/c mice were transtympanically injected with heat-killed Hemophilus influenza bacteria. Untreated and saline injected mice were used as controls. Mice were euthanized at 6, 24, 72 hours and one week after injection, the bullae harvested, and total RNA isolated from the middle ear tissues. Ion homeostasis genes were analyzed with real-time qRT-PCR from the following gene families: Na+,K+-ATPase, claudins, K+ transport channels, epithelial Na+ channels, gap junctions, and aquaporins. Inflammatory genes were also analyzed to document inflammation. Results All inflammatory genes analyzed were significantly upregulated, more at 6 hours than at 24 hours, with the exception of VEGF and Mapk8. Most middle ear ion homeostasis genes experienced downregulation due to inflammation. This was most prominent in the aquaporin and Na+, K+-ATPase genes. Significant upregulation was seen in several genes in response to inflammation and saline independently. Conclusion The innate immune response to bacteria in the middle ear induces expression of several inflammatory genes. Coinciding with this inflammation is the downregulation of numerous ion homeostasis genes that are involved in ion and water transport and maintenance of tight junctions. This may explain the fluid accumulation within the middle ear seen with both acute and chronic otitis media. PMID:21307808

MacArthur, Carol J.; Hausman, Frances; Kempton, J Beth; Trune, Dennis R

2011-01-01

434

The thermally injured ear: a systematic approach to reconstruction.  

PubMed

The ears are special and unique structures that ordinarily are ignored during our daily routines. A thermal injury of relatively moderate proportions can irreparably alter their shape and appearance. Many reconstructive techniques have been garnered to restore these delicate structures. Herculean efforts will consistently fall short of these goals if tissue preservation is not in the forefront of our treatment protocol. Iontophoresis coupled with topical antimicrobial agents have been shown to ameliorate cartilage loss, allowing for delayed operative intervention, when more consistent results may be obtained. Early radical resection of ear soft tissue or structural cartilage should be an endeavor of last resort in all but a few instances, such as unresponsive suppurative chondritis. Segmental restoration of the injured ear allows for dismantling of the various parts to recreate the whole. A facsimile of the original is possible if the major visible distinguishing landmarks are salvaged. Flap resurfacing of exposed cartilage yields closer tissue match, color, and texture, and it affords a greater proclivity for survival than does graft closure. Sacrifice of the helical lip relegates the ear to that of a flat, less-than-optimal appearance. Tissue expansion coupled with cutaneous flap closure will usually preclude this situation. Skin grafting is a valuable tool in our armamentarium but should be used judiciously in situations where graft coverage is either necessary or desired to produce enhanced results. In such instances, the thickness of the graft must be considered, ranging from an almost translucent quality for the antihelix to that of a much thicker graft for the helix. Application and direction of the graft will be determined by the underlying surface contours. Until the reconstruction has been completed, burn patients and their families usually do not view the injured ear that has been snatched from the fires of adversity. The unveiling frequently effects a felicitous atmosphere, because they perceive a relatively normal-looking ear. The final result is all that matters. PMID:1633672

Rosenthal, J S

1992-07-01

435

Formal syntheses of (±)-platensimycin and (±)-platencin via a dual-mode Lewis acid induced cascade cyclization approach.  

PubMed

A mild and efficient dual-mode Lewis acid induced Diels-Alder (DA)/carbocyclization cascade cyclization reaction has been developed for construction of the tricyclic core of ent-kaurenoids in one pot with the aid of a theoretical study on the ?,?-Lewis acidities of a variety of Lewis acids. With ZnBr2 as the dual-mode Lewis acid, a series of substituted enones and dienes underwent DA/carbocyclization cascade cyclization reaction smoothly at room temperature and provided the tricyclic cyclized products in one pot with good yields and high diastereoselectivity. The tricyclic cyclized product has been successfully utilized as a common intermediate for formal syntheses of (±)-platensimycin and (±)-platencin. PMID:23859063

Zhu, Lizhi; Zhou, Congshan; Yang, Wei; He, Shuzhong; Cheng, Gui-Juan; Zhang, Xinhao; Lee, Chi-Sing

2013-08-16

436

Antitussive Activity of the Water-Extracted Carbohydrate Polymer from Terminalia chebula on Citric Acid-Induced Cough  

PubMed Central

Terminalia chebula, a medicinal plant, is widely used in the management of various diseases. As the water extract of its dried ripe fruit is a frequently used preparation, we decided to look for bioactive polysaccharide in this extract. We demonstrate that the obtained polysaccharide fraction, CP, contained a highly branched arabinogalactan protein having a (1 ? 3)-, (1 ? 6)- and (1 ? 3, 6)-linked ?-D-Galp together with (1 ? 5)- and (1 ? 3)-linked ?-L-Araf and nonreducing end units of ?-L-Araf. This polymer possesses strong antitussive property. Our results showed that the number of citric acid-induced cough efforts decreased significantly after the oral application of polysaccharide fraction in a dose of 50?mg?kg?1 body weight. Its antitussive efficacy was higher than cough suppressive effect of standard drug codeine. Therefore, traditional aqueous extraction method provides a major polysaccharide, which induces a pharmacological effect: this could represent an attractive approach in phytotherapeutic managements. PMID:23878602

Chatterjee, Udipta Ranjan; Majee, Sujay Kumar; Ray, Bimalendu

2013-01-01

437

Acid-induced Molten Globule State of a Prion Protein: CRUCIAL ROLE OF STRAND 1-HELIX 1-STRAND 2 SEGMENT.  

PubMed

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

Honda, Ryo P; Yamaguchi, Kei-Ichi; Kuwata, Kazuo

2014-10-31

438

Optoacoustic monitoring of laser correction of the ear shape  

SciTech Connect

Acoustic monitoring of a plastic operation for reshaping the porcine ear using radiation from a Ho:YAG laser was performed to control a change in the elasticity of the ear cartilage. Variations in the cartilage elasticity were controlled by changes in the amplitude and shape of an acoustic wave during the laser action. It is shown that the optoacoustic signal amplitude exponentially decreases at least by a factor of 2-2.5 at the moment of the cartilage reshaping caused by the action of radiation pulses from a Ho:YAG laser. (laser applications and other topics in quantum electronics)

Omel'chenko, A I; Sobol', E N; Sviridov, A P [Institute of Laser and Information Technologies, Russian Academy of Sciences, Troitsk, Moscow Region (Russian Federation); Harding, S; Jumel, K; Walker, R [University of Nottingham, National Centre for Macromolecular Hydrodynamics, Sutton Bonington, Leics (United Kingdom); Jones, N [University of Nottingham, Division of Otorhinolaryngology, Queens Medical Centre, Nottingham (United Kingdom)

2000-11-30

439

The Association of Middle Ear Effusion and Auditory Learning Disabilities in Children.  

ERIC Educational Resources Information Center

The study investigated the prevalence of middle ear effusion (conductive hearing loss) in 32 school aged children found to have auditory learning disabilities. Results indicated a systematic relationship between auditory learning disability and middle ear effusion. (DB)

Glass, Rita

1981-01-01

440

77 FR 35310 - Revisions to the Export Administration Regulations (EAR): Control of Military Training Equipment...  

Federal Register 2010, 2011, 2012, 2013

...Administration Regulations (EAR): Control of Military Training Equipment and Related Items...longer warrant control under Category IX (Military Training Equipment and Training) of...controlling under the EAR and its CCL military training equipment and related...

2012-06-13

441

Atmospheric air vs. normal middle ear gas: Effects on in vitro growth and collagen synthesis in normal middle ear fibroblasts  

Microsoft Academic Search

Summary  The present study was undertaken to quantitate the effects of atmospheric air and normal middle ear gas on cultured fibroblasts\\u000a obtained from normal rabbit middle ear mucosa. The cells were exposed to three different gas compositions: 7% O2:5% CO2:88% N2, 21% O2:5% CO2:74% N2, and 75% O2:5% CO2:20% N2. The growth was monitored by measuring the total content of cell

T. Ovesen; M. Gaihede; P. Scousboe; T. Ledet

1994-01-01

442

Microendoscopy of the eustachian tube and the middle ear  

Microsoft Academic Search

Progressive miniaturization of flexible fiberoptic instruments has made it possible to perform atraumatic endoscopy of the Eustachian tube and tympanic cavity with an intact ear drum. By means of a special set of carrier- and balloon-catheters which are partly actively steerable, flexible microendoscopes with outside diameters of 290 - 700 micrometers are inserted through the nasal cavity into the nasopharyngeal

Juergen U. Hopf; Marietta Linnarz; Peter Gundlach; Hans H. Scherer; C. Lutze-Koffroth; S. Loerke; Karl H. Voege; Johannes Tschepe; Gerhard J. Mueller

1992-01-01

443

MicroRNAs in sensorineural diseases of the ear  

PubMed Central

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

Ushakov, Kathy; Rudnicki, Anya; Avraham, Karen B.

2013-01-01

444

Music to our ears During a visit to Santa  

E-print Network

#12;Music to our ears During a visit to Santa Cruz coordinated by UCSC's Arts & Lectures, Wynton Marsalis helped the young--and young at heart--celebrate the timeless music of Duke Ellington. Features- electronics and other areas of research that will be key to the growth of the high-tech industry. A sleuth

California at Santa Cruz, University of

445

AN EXPERIMENTAL STUDY OF MIDDLE-EAR VIBRATIONS IN RATS  

E-print Network

. Funnell1, 2 1 Department of BioMedical Engineering, McGill University 2 Department of Otolaryngology, Mc-ear mechanics. Rats are potentially very useful for this purpose. They are low in cost, they are genetically. It is also one of the most common birth defects, affecting 3 in 1 000 babies. Hearing loss is the third

Funnell, W. Robert J.

446

FOOD HABITS AND HUNTING RANGES OF SHORT-EARED OWLS  

Microsoft Academic Search

ABSTRCT.--The diet of the Short-eared Owl (Asio flammeus) was quantified by analyzing 400 pellets collected in two agricultural landscapes of southern Chile (Osorno and Chahuilco). Diet composition fluctuated seasonally and included several species of small mammals, birds, and insects. Almost 80% of the annual biomass consumed was from two rodent species (Akodon olivaceus and Rattus norvegicus) and of a bird

DAVID R. MARTINEZ; RICARDO A. FIGUEROA; CARMEN L. OCAMPO; FABIAN M. JAKSIC

447

Speech perception in impaired ears Jont B. Allen, Andrea Trevino  

E-print Network

-normally articulated utterances of the same consonant can result in totally different responses. That is, one (i.e., /k for diagnosing speech disorders in individuals with damaged inner ears seem fundamentally broken. Today, when children can temporary loose their hearing, and this can interfere with learning. It is not until the first

Allen, Jont

448

Baby corn, green ear, and grain yield of corn cultivars  

Microsoft Academic Search

Most maize cultivars have been developed for grain production. Because superior cultivars may differ in their exploiting purposes, interest has been demonstrated for the evaluation of corn cultivars with regard to their baby corn, green ear, and grain yields production ability. In the present work ten corn cultivars (AG 405, AG 1051, AG 2060, AG 6690, AG 7575, AG 8080,

Itala Paula de C. Almeida; Paulo Sérgio L. e Silva; Maria Z. de Negreiros; Zenaide Barbosa

2005-01-01

449

Efficiency of ear protectors in laboratory and real life tests.  

PubMed

The effectiveness of ten different ear-protectors (6 types of earmuffs and 4 types of earplugs) has been tested under laboratory conditions and in the real occupational environment. Three methods were used: (1) physical, utilizing a dummy head; (2) subjective, real-ear, executed on trained human subjects; (3) subjective, measuring TTS2 resulting from occupational, one-workday exposure. It could be shown that the ear protection efficiency ascertained on the basis of TTS2 measurements on workers exposed to noise in their occupational environment is, in nearly all cases, smaller than the efficiency expected, taking into account the sound damping of the same protectors, tested under laboratory conditions, using the physical or real-ear method. Measurements of TTS2 were found to give the best data needed to define the protectors' efficiency, since they include, simultaneously, the impact of various environmental factors, the subjective reactiveness, the nature of the professional task and the acoustical features of the protector used. Therefore this method enables the estimation of the real protection given to workers with a risk of noise-induced hearing loss. PMID:2379964

Pawlas, K; Grzesik, J

1990-01-01

450

Biology and migration of Eared Grebes at the Salton Sea  

Microsoft Academic Search

The Eared Grebe (Podiceps nigricollis Brehm) is the North American bird species most closely associated with highly saline habitats, and in winter and early spring it is the most abundant waterbird at the Salton Sea. During the fall, the great majority of the North American population stages at hypersaline lakes in the Great Basin, departing in early winter for wintering

Joseph R. Jehl; Robert L. McKernan

2002-01-01

451

An outbreak of erysipelas in eared grebes (Podiceps nigricollis).  

PubMed

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. PMID:16502704

Jensen, W I; Cotter, S E

1976-10-01

452

Analysis of chick (Gallus gallus) middle ear columella formation  

Microsoft Academic Search

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

Jamie L Wood; Ami J Hughes; Kathryn J Mercer; Susan C Chapman

2010-01-01

453

Middle Ear Disorders and Hearing Loss in Native Hawaiian Preschoolers.  

ERIC Educational Resources Information Center

Native Hawaiian preschoolers (n=172) received a battery of tests that included pure-tone audiometry, tympanometry, acoustic reflectometry, and pneumatic otoscopy. Approximately 15% of children failed a majority of the tests. Results are discussed in comparison to other indigenous groups at risk for middle ear disorders and hearing loss.…

Pang-Ching, Glenn; And Others

1995-01-01

454

The South Africa bionic ear-description and preliminary results  

Microsoft Academic Search

Bionic ear is the popular name given to the cochlear implant, a system for the functional electrical stimulation of the cochlea of a profoundly deaf person. The object of this electrical stimulation is to imitate the function of a normally functioning cochlea so that the neural code conducted to the brain is as close as possible to the neural code

J. J. Hanekom; J. J. D. Van Schalkwyk

1989-01-01

455

Early middle ear effusion and language at age seven  

Microsoft Academic Search

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

Dale L. Johnson; David P. McCormick; Constance D. Baldwin

2008-01-01

456

Personal verification using ear and palm-print biometrics  

Microsoft Academic Search

This paper presents a multimodal biometric identification system based on new features extraction of palm and ear. We describe a new biometric approach to personal identification using robust pattern recognition Each element of this set is a complex feature obtained by combining position- and scale-tolerant edge detectors over neighboring positions and multiple orientations. Our system¿s architecture is motivated by a

Karim Faez; Sara Motamed; Mahboubeh Yaqubi

2008-01-01

457

Ear's electrical missing link found BY BRYN NELSON  

E-print Network

to hearing loss, and the discovery may aid the search for treatments for some of the more than 300 known in and create an electrical voltage, creating a signal that zips from connected neurons to the brain, which discovery." Although researchers suspected that the inner ear's hair cells contained such a channel, Oghalai

Allen, Jont

458

Ear recognition based on 3D keypoint matching  

Microsoft Academic Search

This paper proposes a novel ear recognition approach based on 3D keypoint matching. At first, the 3D keypoints are detected using the shape index image and the scale space theory. Then two principal orientations are assigned and the normalized local range image is obtained, which can provide invariance to 3D rotation and transformation for the following local descriptor construction. Finally,

Hui Zeng; Ji-Yuan Dong; Zhi-Chun Mu; Yin Guo

2010-01-01

459

Mechanics of a 'simple' ear: tympanal vibrations in noctuid moths.  

PubMed

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

Windmill, J F C; Fullard, J H; Robert, D

2007-08-01

460

Sound fields in generally shaped curved ear canals.  

PubMed

The sound field in the external ear can be subdivided into a distinctly three-dimensional part in front of pinna and concha, a fairly regular part in the core region of ear canals, and a less regular part in the drum coupling region near the tympanic membrane. The different parts of the sound field and their interaction have been studied using finite elements. A "pinna box" enclosing the pinna provides both a realistic coupling of the external space to the ear canal and the generation of sound. The sound field in the core region turns out to be not that regular as mostly assumed: near pressure minima and maxima "one-sided" isosurfaces (surfaces of equal pressure magnitude) occur, which are inconsistent with the notion of a middle axis, in principle. Nevertheless such isosurfaces can be seen as part of a "fundamental sound field," which is governed by the principle of minimum energy. Actually, the sound transformation through narrow ducts is little affected by one-sided isosurfaces in between. As expected, the beginning of the core region depends on frequency. If the full audio range up to 20 kHz is to be covered, a location in the first bend of the ear canal is found. PMID:19425657

Hudde, H; Schmidt, S

2009-05-01