No description available.

by P.J. Wormald. / Thesis (M.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 195-217). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Thesis (doctoral)--Freie Universität Berlin, 1979.

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 6 uppsatser.

No description available.

The purpose of this study was to investigate the central auditory processing of children who had sustained chronic middle ear problems during their early language-learning years. A 60% compressed recording of the NU-6 speech discrimination word lists was administered to twenty eight and nine year old normal hearing public school children, reported by their parents to have had repeated middle ear problems during their early years, and to twenty control subjects matched for age from the same public school classes. Differences in compressed and uncompressed word discrimination scores between the experimental and control groups were not found to be statistically significant. These results indicate that the experimental subjects' ability to process compressed speech was not impaired by early middle ear difficulties. The alternative was suggested that if these children actually sustained central damage due to distorted or degraded input during their hearing deficit episodes, then such effects may be neutralized by subsequent auditory experience and neurological maturity. A significant difference for both groups of children was noted between scores obtained with NU-6 lists 2A and 3A at 60% compression. While apparently equivalent in the uncompressed form, list 3 was found to be significantly more difficult than list 2 when compressed. Implications for further research are discussed.

People with sensorineural hearing loss historically have difficulties understanding speech. For this reason, speech- or word-recognition abilities typically are assessed in an audiologic evaluation. The Northwestern University Auditory Test No. 6 (NU-6) is often used to evaluate this ability. One of the main variables in understanding speech is the speaker of the materials. It is well established that different speakers produce speech that is differentially intelligible. Some speakers are easier to understand than other speakers. The purpose of this study was to determine the word–recognition difference between the Auditec and VA speaker versions of NU-6 by older listeners with sensorineural hearing loss (OHL). Young adults with normal hearing (YNH) exhibit slightly better recognition performance on the Auditec version than on the VA version. A direct comparison of these two versions of NU-6 using the same older listeners for both materials has not been made. This study was conducted in quiet using a simple factorial design. Thirty-six OHL listeners participated (M = 71.6 years). Pure-tone thresholds were obtained on the test ear using a computerized protocol, Automated Method for Testing Auditory Sensitivity (AMTAS). Each participant was presented randomly 1200 NU-6 words (2 speakers by 6 levels by 100 words) over three sessions. Presentation levels of -2- to 38-dB SL in 8-dB steps for the recorded materials were referenced to the three-frequency, pure-tone average. In each of 3, 1-hour sessions, 25-practice items were given followed by 400 of the 1200 test words. A questionnaire assessed the perceived level of difficulty of each speaker. Overall, recognition performance was better on the Auditec version (68.7%) than on the VA (58.2%) version. This better performance on the Auditec version was observed at each presentation level. Of the 200 NU-6 words, the Auditec version produced better overall performances on 84.3%. The differences were maximized at the 50% point: 5.9-dB SL (Auditec) and 11.7-dB SL (VA). Only at the two highest presentation levels (30- and 38-dB SL) were equivalent performances achieved. Considering the 6 presentation levels of the 200 words, 1200 recognition performances were available, of which better performances were obtained with the Auditec version on 64.3%, with the VA version on 19.5%, and with equal performances on 16.2%. The results are overwhelming that for the conditions used in this study the Auditec version of NU-6 was easier to understand than the VA version. The only similarities between the data from the two speakers were the slopes of the functions at the 50% points, 3.3%/dB (SD = 1.1%/dB) and 3.5%/dB (SD = 1.0%/dB) for the Auditec and VA versions, respectively. The results of the questionnaire revealed that 83.3% of the participants reported that the Auditec version was easier to understand. In a study of YNH listeners using the same experimental paradigm, similar, but smaller, differences were observed between the two versions of NU-6. Overall, the Auditec version of NU-6 was easier to understand than the VA version for reasons ranging from calibration issues to variables that are only speculative about auditory function.

The cochlea, or inner ear, is a space fully enclosed within the temporal bone of the skull, except for two membrane-covered portals connecting it to the middle ear space. One of these portals is the round window, which is covered by the Round Window Membrane (RWM). A longstanding clinical goal is to gain reliable and precise access to the cochlea with the purpose of delivering therapeutics to treat a plethora of auditory and vestibular disorders, or to aspirate fluids for diagnostic purposes. Standard of care for several difficult-to-treat diseases calls for injection of a therapeutic substance through the tympanic membrane into the middle ear space, after which a portion of the substance diffuses across the RWM into the cochlea. The efficacy of this technique is limited by an inconsistent rate of molecular transport across the RWM. Other solutions for delivery require either traumatic drilling through the bone of the cochlea, or perforating the delicate RWM, which is prone to rupturing with the use of regular surgical tools. For conducting precision diagnostics, even fewer options exist. In our research group, utilizing a newly available technology called Two-Photon Lithography, (2PP) we have developed a suite of ultra-sharp microneedles that are able to create repeatable and reliable perforations in the RWM without tearing. These holes were seen to spontaneously heal within 48 hours, and did not cause any audiological or functional consequences. Furthermore, we have designed needles that can, while inserted into the cochlea, inject or aspirate fluid of microliter quantities, to and from the inner ear, safely. In this thesis, I will discuss the development of these microneedles: their methods, design, use, and modeling. The results show that the microneedles hold great promise to diagnose and treat hearing and balance disorders.

Thesis (MSc)--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Strain ST4SA, isolated from soya beans, was identified as Enterococcus mundtii. BacST4SA, a bacteriocin produced by strain ST4SA inhibited the growth of Acinetobacter baumannii, Bacillus cereus, Clostridium tyrobutyricum, Enterococcus faecalis, Enterococcus faecium, Lactobacillus sakei, Propionibacterium spp., Streptococcus caprinus, Pediococcus sp., Listeria monocytogenes, Staphylococcus aureus, Streptococcus pneumoniae, and unidentified middle ear isolates A, BW, DW, F, G, and H. BacST4SA was active against Pseudomonas aeruginosa G, BG, I, J, B and E, although variable degrees of resistance were observed for some strains. BacST4SA is positively charged, hydrophobic, contains the YGNGV sequence in the N-terminal, a double-glycine processing site and a disulphide bridge, all of which is typical of a class IIa bacteriocin. The operon, which contains a structural-, ATP-dependent transporter- and immunity gene, is located on a 50-kb plasmid. The 58-amino acid prepeptide is homologous to mundticin KS, mundticin AT06 and bacteriocin QU 2, and differs from enterocin CRL35 by only two amino acids. The 674-amino acid ATP-dependent transporter, consisting of a peptidase C39B domain, an ABC-transporter and an ABC-DLP family domain, displayed 98.9% homology to mundticin KS and 99.25% to enterocin CRL35. The 98-amino acid immunity gene of bacST4SA is completely homologous to enterocin CRL35 and 96.9% to mundticin KS. BacST4SA is 3.950 kDa in size, based on electron spray mass spectrometry. The peptide was isolated from the cell-free supernatant, precipitated with 80% saturated ammonium sulphate, dialysed and freeze-dried to 1 638 400 AU (arbitrary units) per ml. No change in antimicrobial activity was recorded when bacST4SA was incubated in buffer ranging from pH 2 to 12, heated to 100 °C for 90 min and 121 °C for 20 min, and when incubated in the presence of Tween 20, Tween 80, Triton X-100, SDS, urea, EDTA, middle ear fluid and blood. Optimal levels of bacST4SA production (51 200 AU/ml) was recorded after 14 h of growth in MRS broth at 30°C. Maximum production (102 400 AU/ml) was recorded in modified MRS media supplemented with tryptone, yeast extract, a combination of tryptone and yeast extract, K2HPO4 (10.0 or 20.0 g/l), or with the addition of DL-6,8-thoictic acid, L-ascorbic acid, and thiamine, respectively. BacST4SA is bactericidal towards E. faecium HKLHS and bacteriostatic towards S. pneumoniae 40 and middle ear isolates F, BW and H. The peptide adsorbed maximal (94%) to S. pneumoniae 40, P. aeruginosa 25 and E. faecium HKLHS. BacST4SA forms pores in the cytoplasmic membrane of sensitive cells, leading to dissipation of the cell membrane and leakage of cytoplasmic material. BacST4SA was compared with various other antimicrobial treatment agents, and revealed similar to a higher activity towards a number of these agents. BacST4SA revealed a similar level of activity against E. faecium HKLHS and middle ear pathogens P. aeruginosa J and S. pneumoniae 27 when compared with tetracycline (30μg). However, bacST4SA revealed much higher activity when compared to nasal sprays, aminoglycosides, cephalosporins, fluoroquinolones, lincosamides, macrolides, nitroimidazole, penicillin, quinolones, sulfonamides, chloramphenicol, furanzolidone, fusidic acid, rifampicin, trimethoprim, trimethoprim-sulfamethoxazole and vancomycin when tested in vitro. / AFRIKAANSE OPSOMMING: Stam ST4SA, geïsoleer uit sojabone, is as Enterococcus mundtii geidentifiseer. BacST4SA, ‘n bakteriosien geproduseer deur stam ST4SA het die groei van Acinetobacter baumannii, Bacillus cereus, Clostridium tyrobutyricum, Enterococcus faecalis, Enterococcus faecium, Lactobacillus sakei, Propionibacterium spp., Streptococcus caprinus, Pediococcus sp., Listeria monocytogenes, Staphylococcus aureus, Streptococcus pneumoniae en ongeïdentifiseerde middeloor isolate A, BW, DW, F, G, en H geinhibeer. BacST4SA is aktief teen Pseudomonas aeruginosa stamme G, BG, I, J, B en E, alhoewel effense weerstand soms waargeneem is. BacST4SA het ‘n netto positiewe lading, is hidrofobies, bevat die YGNGV-volgorde in die N-terminaal, ‘n dubbel-glisien prosesserings setel en ‘n disulfied brug, kenmerkend van klas IIa bakteriosiene. Die operon, wat bestaan uit ‘n strukturele geen, ‘n ATP-afhanklike transport sisteem geen en ‘n immuniteits-geen, is op ‘n 50 kb plasmied gelokaliseer. Die voorloper peptied (58 aminosure lank), is homoloog aan mundticin KS, mundticin AT06 en bakteriosien QU 2 en verskil van enterocin CRL35 met slegs twee aminosure. Die ATP-afhanklike transporter (674 aminosure lank) bestaan uit ‘n peptidase C39B domein, ‘n ABC-transporter en ‘n ABC-DLP tipe domein en is 98.9% homoloog aan mundticin KS and 99.25% aan enterocin CRL35. Die immuniteits-geen (98 aminosure lank) van bacST4SA is ten volle homoloog aan enterocin CRL35 en 96.9% homoloog aan mundticin KS. BacST4SA is 3.950 kDa groot, gebaseer op elektrosproei-massa spektrometrie. Die peptied is uit selvrye supernatant geïsoleer, met 80% versadigde ammonium sulfaat gepresipiteer, gedialiseer en gevriesdroog tot ’n finale konsentrasie van 1 638 400 AE (arbitrêre eenhede) per ml. Geen verandering in antimikrobiese aktiwiteit is waargeneem tydens inkubasie van bacST4SA in buffer van pH 2 tot 12, tydens verhitting (100 °C vir 90 min en 121 °C vir 20 min) en tydens inkubasie in die teenwoordigheid van Tween 20, Tween 80, Triton X-100, SDS, ureum, EDTA, middeloor vloeistof en bloed. Optimale vlakke van bacST4SA produksie (51 200 AE/ml) is na 14 h groei in MRS media by 30°C waargeneem. Maksimale vlakke van die peptied (102 400 AE/ml) is geproduseer in gemodifiseerde MRS medium, aangevul met triptoon, gisekstrak, ‘n kombinasie van triptoon en gisekstrak, K2HPO4 (10.0 of 20.0 g/l), of met byvoeging van DL-6,8-thioktiensuur, L-askorbiensuur, en tiamien onderskeidelik. BacST4SA is bakteriosidies teenoor E. faecium HKLHS en bakteristaties teenoor S. pneumoniae 40 en middeloor isolate F, BW en H. Die peptied adsorbeer optimaal (94%) aan S. pneumoniae 40, P. aeruginosa 25 en E. faecium HKLHS. BacST4SA vorm porieë in die selmembraan van sensitiewe selle en lei tot vernietiging van die selmembraan en lekkasie van die sitoplasma inhoud. In vergelykende studies het bacST4SA ‘n soortgelyke en selfs hoër antimikrobiese aktiwiteit teenoor ‘n aantal bekende antimikrobiese middels getoon. Die aktiwiteit van bacST4SA is soortgelyk aan dié van tetrasiklien (30μg) in toetse teen E. faecium HKLHS en middeloor patogene P. aeruginosa J en S. pneumoniae 27. BacST4SA het egter in ’n in vitro vergelyking met neussproeie, aminoglisiedes, cephalosporiene, fluoroquinolone, lincosamides, makroliede, nitroimidazole, penisilien, quinolone, sulfonamide, chloramphenicol, furanzolidone, fusiensuur, rifampisien, trimethoprim, trimethoprim-sulfamethoxazool en vankomisien ‘n baie hoër aktiwiteit teen patogene getoon.

Made available in DSpace on 2014-08-20T14:37:54Z (GMT). No. of bitstreams: 1 dissertacao_eduardo_garcia_fontoura.pdf: 1413088 bytes, checksum: 273e6ae790ff7b3245afb5b091828f85 (MD5) Previous issue date: 2014-02-14 / External otitis is an inflammation of the outer ear and ear canal, which may or may not be of infectious cause. Negligence will lead to recurrence, hampering treatment and causing bacterial resistance to conventional methodologies. In this context, medicinal plants and plant extracts may be an alternative. Triticum aestivum (wheat) has been shown to act as an antioxidant, anti-inflammatory, pain-killer, as well as used in wound healing. Rosmarinus officinalis L. (rosemary) has antibacterial, anti-inflammatory, pain-killer, anti-mutagenic, diuretic, expectorant, and antioxidant effects. In this context, the objective of this study was to assess the use of wheat and rosemary aqueous extracts, and rosemary essential oil, in the treatment of infectious external otitis. Experimental otitis was induced in rats Wistar with croton oil at 5% in acetone, followed by the introduction of Staphylococcus aureus in the outer ear canal. Animals were separated according to the treatment group: GI 25% wheat aqueous extract in propylene glycol; GII 25% rosemary aqueous extract in propylene glycol; GIII 5% rosemary essential oil in propylene glycol; GIV propylene glycol; and GV saline. The animals were treated for up to seven days, and assessed regarding clinical (according to the Emgard & Hellström method) and hitopathological alterations, on days four, six and ten. Promising results were observed on animals treated with both aqueous extracts, primarily in GI (wheat), but also in GII (rosemary), both were able to reduce clinical and histopathological parameters beyond the effect of the control. This study shows that the aqueous extract of both T. aestivum and R. oficinallis promoted the hastening of the healing process of infectious external otitis. / A otite externa é a inflamação do conduto auditivo externo, com etiologia infecciosa ou não. Casos de negligência fazem com que ocorram recidivas, dificultando tratamento e elevando a resistência microbiana aos métodos convencionais, tornando assim as plantas medicinais uma alternativa. O Triticum aestivum (trigo), já demonstrou ação antioxidante, anti-inflamatório, antimicrobiano, hepatoprotetor e cicatrizante. O Rosmarinus officinalis L. (alecrim) possui propriedades medicinais como antimicrobiano, anti-inflamatório, analgésico, antimutagênico, diurético, expectorante e antioxidante. Neste contexto, objetivou-se avaliar a utilização dos extratos aquosos de trigo e alecrim e óleo essencial de alecrim no tratamento da otite externa infecciosa experimental. A otite externa foi induzida em 64 ratos Wistar através da instilação de óleo de cróton 5% em acetona em conjunto com Staphylococcus aureus no conduto auditivo dos animais. Os tratamentos foram divididos em extrato aquoso de trigo 25% em propilenoglicol (GI), extrato aquoso de alecrim 25% em propilenoglicol (GII), óleo essencial de alecrim 5% em propilenoglicol (GIII), propilenoglicol (GIV) e solução fisiológica (GV). Os animais foram tratados por até sete dias e realizadas análises macroscópicas aos quatro, seis e dez dias através do método de Emgård & Hellström para coloração, diâmetro, efusão, além da análise histopatológica, em quatro animais por grupo. Foram observados resultados promissores com o extrato aquoso de trigo (GI), e extrato aquoso de alecrim (GII), sendo capazes de reduzir os parâmetros clínicos macroscópicos, assim como os parâmetros histopatológicos. Nas condições experimentais deste trabalho, a concentração utilizada de óleo essencial não foi efetiva. Assim, demonstrou-se que os extratos aquosos de trigo e alecrim a 25% em propilenoglicol promovem a aceleração da resolução da otite externa infecciosa.