• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 82
  • 40
  • 9
  • 6
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 185
  • 32
  • 28
  • 27
  • 24
  • 24
  • 22
  • 22
  • 21
  • 21
  • 19
  • 17
  • 17
  • 17
  • 16
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Apoptotic mechanism of anti-tumor treatment in human laryngeal squamous cell cancer infected with human papillomavirus type 16 (HPV16). / CUHK electronic theses & dissertations collection

January 2006 (has links)
In addition, we investigated the cytotoxic effect of a widely used chemotherapeutic agent 5Fu on laryngeal squamous cell cancer cell lines and evaluated the role of p53 in 5Fu treatment. We found that the apoptosis and G1/S cell arrest mediated by 5Fu in laryngeal cancers is p53-independent but p21 WAF1/CIP1-dependent. We further demonstrated the effect of 5Fu on HPV16-associated laryngeal cancer cells. Using cytotoxicity assay and Annexin V staining, we proved that 5Fu induces apoptosis in all of the transfected cells in a dose- and time-dependent manner, suggesting that the process was not prevented by HPV16 E6 or E7. 5Fu induced the accumulation of active pRb and cyclin dependent kinase inhibitor p21WAF1/CIP1 together with an increase in Bak and Bax expression and a decrease in Bcl-2 levels in all the transfected cells. In addition, G1/S phase cell cycle arrest was associated with the antiproliferation activity of 5Fu in all cell lines. Through RT-PCR, 5Fu also presented some effects on the E6 and E7 oncoproteins of HPV16 in transfected UMSCC 12 cells. / Our results suggest that HPV16 E6 and E7 oncoproteins do not prevent 5Fu medicated apoptosis and G1/S cell arrest in laryngeal cancers. The anti-cancer effect of 5Fu is probably decided by the level of p21 WAF1/CIP1 while the sensitivity of laryngeal cancer cells responded to 5Fu treatment is associated with the increase of Bak or/and the decrease in Bcl-2, not with the HPV16 viral proteins and p53 status. 5Fu also presented some effects on the E6 and E7 oncoproteins of HPV16 in laryngeal cancer. However, the anti-viral effect of 5Fu still needs further investigation. / Our study indicated that (1) the evasion of apoptosis mediated by HPV16 E6 and E7 plays a critical role in laryngeal carcinogenesis; (2) HPV16 E6 or E7 plays an important role in regulating the expression of Bak, Bax and Bcl-2; (3) The degradation of Bak by HPV16 E6 is not caused by interacting with the promoter of Bak; (4) The induction of Bcl-2 is mediated through HPV16 E7; (5) HPV16 transfection does not interfere with the apoptosis and cell cycle arrest mediated by 5Fu in human laryngeal squamous cancer cells. / There is a growing body of evidence that human papillomavirus type 16 (HPV16) is involved in the development of human laryngeal cancer, especially in Chinese population. The two oncoproteins, HPV16 E6 and E7 that target host cell tumor suppressor proteins p53 and Rb respectively, may generate antiapoptotic effects and induce cell immortalization. However, the effect of both oncoproteins on apoptosis in laryngeal cancers is not completely clear. In this study, we demonstrated the possible mechanism of high risk HPV16 in laryngeal carcinogenesis and evaluated the effect of 5Fu on HPV16-positive laryngeal cancer cells. / We employed two human laryngeal cancer cell lines---UMSCC12 (with truncated p53) and UMSCC11A (with mutant but functional p53) in this study. These two cell lines were stably transfected with HPV16 E6, E7 or empty vector, pcDNA3.1, which provided a good foundation for further study on the carcinogenic mechanism of HPV16 E6 or E7 in human laryngeal cancers. Through Annexin V staining and protein stability assay, we found that the transfection of HPV16 E6 and E7 induced fewer spontaneous apoptosis in both UMSCC11A and UMSCC12 cells accompanied with enhanced protein stability of Bcl-2 and increased protein degradation of Bak. Similar results were obtained when E6- and E7-transfected cells exposed to apoptosis stimuli---TNF-alpha/CHX. These results indicate that stable transfection of E6 and E7 in human laryngeal cancer cells on one hand shortened the half-life of Bak protein, and on the other hand, enhanced the steady-state levels of Bcl-2 protein. In order to gain insight into the role of Bak and Bcl-2 in regulating apoptosis in HPV-associated laryngeal cancer cells, we performed transient transfection of Bcl-2 into E6- and E7-transfected cells. It is found that HPV16 E7 statistically enhanced the expression of Bcl-2 in laryngeal cancer, indicating that the induction of Bcl-2 require the transfection of HPV16 E7. Furthermore, Luciferase assay was performed to investigate whether the viral proteins E6 and E7 altered the stability of Bak through interaction with the promoter of Bak. Negative results were obtained, suggesting that E6 or E7 do not alter the transcription activity of Bak, indicating the degradation of Bak by E6 or E7 may be mediated through other mechanisms. / Liu Han-ching. / "August 2006." / Advisers: C. A. van Hasselt; George G. Chen. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1569. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 245-274). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
52

Laryngeal sensory testing using flexible endoscopy

Satoh, Asako Kaneoka 07 November 2016 (has links)
Sensory input from the laryngeal mucosa is vital for triggering protective airway reflexes. The laryngeal adductor reflex (LAR) is a brief vocal fold adductor reflex in response to stimulation of the laryngeal mucosa. Depressed LAR may lead to aspiration of foreign substances into the airway. Loss of laryngeal sensation has thus been considered as one of the risk factors associated with aspiration and airway complications in patients with dysphagia. Laryngeal sensation can be endoscopically tested by lightly and briefly touching a patient’s arytenoids or epiglottis with the tip of a flexible laryngoscope (the touch method). In a preliminary study, we endoscopically investigated the laryngeal sensation and swallowing ability of healthy adults and patients with dysphagia. The results indicated an association between sensory deficits as determined by the touch method and penetration/aspiration of trial boluses in both healthy adults and patients with dysphagia. However, the pressure applied to the larynx using this touch method might not be consistent, and the expected responses elicited by this method were uncertain. Study 1 of this dissertation investigated the variability in the pressure delivered by clinicians using the touch method. The study also reported on the types of various subject responses to the touches. The results revealed that there was a wide range of pressure levels exerted by examiners. This suggested the need for further research to establish the validity of this diagnostic tool. The study also showed that the LAR always occurred in response to touch in normal volunteers, suggesting that this technique may be quite sensitive at detecting sensory deficits in a person who does not exhibit an LAR in response to touch. Study 2 examined hospitalized patients with symptoms of dysphagia. The question of interest was whether an absent LAR in response to touch was associated with aspiration or pneumonia. No significant association was found between absent LAR and aspiration of food or liquid; however, a significant association was observed between absent LAR and the occurrence of pneumonia. The study indicated that the touch method has potential for predicting pneumonia in patients with swallowing problems. / 2017-11-07T00:00:00Z
53

Effects of HPV16 E6 and E7 on apoptosis in human laryngeal squamous carinoma cells.

January 2003 (has links)
Du Jing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 70-89). / Abstracts in English and Chinese. / ABSTRACT --- p.I / ACKNOWLEDGMENTS --- p.IV / PUBLICATIONS --- p.V / LIST OF FIGURES --- p.VI / LIST OF TABLES --- p.VII / ABBREVIATIONS --- p.VIII / CONTENTS --- p.X / Chapter CHAPTER ONE: --- INTRODUCTION AND LITERATURE / Chapter 1.1 --- Laryngeal carcinoma and HPV --- p.1 / Chapter 1.2 --- HPV --- p.2 / Chapter 1.3 --- Human papillomavirus E6 protein --- p.6 / Chapter 1.3.1 --- Transformation by HPV E6 --- p.7 / Chapter 1.3.2 --- Inhibition of apoptosis by E6 --- p.8 / Chapter 1.3.3 --- Alteration of gene transcription --- p.11 / Chapter 1.3.4 --- E6 interation with other proteins --- p.12 / Chapter 1.3.5 --- E6 as a therapeutic target --- p.14 / Chapter 1.4 --- HPV E7 protein --- p.15 / Chapter 1.4.1 --- Regulation of viral life cycle by HPV E7 --- p.16 / Chapter 1.4.2 --- Degradation of retinoblastoma tumor suppressor by HPV E7 --- p.18 / Chapter 1.4.3 --- Inhibition of p53 by HPV E7 --- p.22 / Chapter 1.4.4 --- Interaction with other proteins by HPV E7 --- p.24 / Chapter 1.5 --- Objective --- p.26 / Chapter CHAPTER TWO: --- GENERAL MATERIALS AND METHODS --- p.28 / Chapter 2.1 --- Materials --- p.28 / Chapter 2.1.1 --- Materials for cDNA and RNA manipulation --- p.28 / Chapter 2.1.2 --- Culture media and transfection reagents --- p.28 / Chapter 2.1.3 --- Antibodies --- p.29 / Chapter 2.1.4 --- Materials for protein manipulation --- p.29 / Chapter 2.1.5 --- Kits --- p.30 / Chapter 2.1.6 --- Instrumentation --- p.31 / Chapter 2.2 --- Methods --- p.32 / Chapter 2.2.1 --- Plasmid construction --- p.32 / Chapter 2.2.1.1 --- DNA preparation --- p.34 / Chapter 2.2.1.2 --- DNA ligation --- p.34 / Chapter 2.2.1.3 --- Transformation of competent E. coli --- p.35 / Chapter 2.2.2 --- Mini preparation --- p.35 / Chapter 2.2.3 --- Clone selection and confirmation --- p.37 / Chapter 2.2.4 --- Sequencing gel electrophoresis --- p.37 / Chapter 2.2.5 --- Cell culture and cytokine treatment --- p.39 / Chapter 2.2.6 --- Plasmid transfection --- p.39 / Chapter 2.2.7 --- Confirming construction of stable cell lines by RT-PCR --- p.40 / Chapter 2.2.7.1 --- Total cellular RNA extraction --- p.40 / Chapter 2.2.7.2 --- First strand cDNA synthesis --- p.41 / Chapter 2.2.7.3 --- Polymerase chain reaction (PCR) --- p.41 / Chapter 2.2.8 --- Fluorescence microscopy and imaging --- p.43 / Chapter 2.2.9 --- DNA fragmentation assay --- p.44 / Chapter 2.2.10 --- Protein detection --- p.46 / Chapter 2.2.10.1 --- Preparation of protein extract --- p.46 / Chapter 2.2.10.2 --- SDS-PAGE electrophoresis and protein transfer --- p.47 / Chapter 2.2.10.3 --- Immunoblotting analysis --- p.47 / Chapter 2.2.11 --- Statistical analysis --- p.48 / Chapter CHAPTER THREE: --- RESULTS --- p.49 / Chapter 3.1 --- Plasmid construction --- p.49 / Chapter 3.2 --- Expression of HPV16 viral oncogenes in transfected UMSCC12 --- p.51 / Chapter 3.3 --- HPV16 E6 and E7 protect apoptosis induced by TNF-alpha and CHX --- p.53 / Chapter 3.4 --- Detection of apoptosis with fluorescence staining --- p.55 / Chapter 3.5 --- Regulation of the expression of apoptosis-associated proteins by E6 and E7 oncoproteins --- p.57 / Chapter CHAPTER FOUR: --- DISCUSSION --- p.59 / Chapter CHAPTER FIVE: --- CONCLUSION AND FUTURE PERSPECTIVE --- p.68 / REFERENCES --- p.70 / APPENDIX DNA SEQUENCING RESULTS --- p.90
54

Estudo da deglutição em pacientes com distonia laríngea antes e após o tratamento com toxina botulínica / Study of swallowing in patients with laryngeal dystonia before and after treatment with botulinum toxin.

Alves, Leda Maria Tavares 18 November 2013 (has links)
A distonia é uma síndrome que consiste de contrações musculares involuntárias que resultam em movimentos distorcidos e repetitivos e/ou posturas anormais. O tratamento pode ser por farmacoterapia, com drogas anticolinérgicas ou com a injeção de toxina botulínica no grupo de músculos afetados. O objetivo do trabalho foi avaliar a deglutição nos pacientes com distonia laríngea, antes e após o tratamento com a toxina botulínica. Nossa hipótese foi que a toxina botulínica modificaria a deglutição dos pacientes com distonia laríngea. Foram avaliados 17 indivíduos adultos, acima de 18 anos de idade, com diagnóstico clínico de distonia laríngea antes e após o tratamento com o uso de toxina botulínica do tipo A, e 20 indivíduos adultos saudáveis como controles. Os participantes foram submetidos à anamnese fonoaudiológica e avaliação videofluoroscópica da deglutição. Os pacientes com distonia foram avaliados antes e 30 dias após a injeção de toxina botulínica, guiada por eletromiografia. Na videofluoroscopia foram avaliadas 6 deglutições de 5mL, sendo 3 na consistência líquida (sulfato de bário 100%, e 3 na consistência pastosa (3g do espessante alimentar ThickenUp Clear, em 50 mL de sulfato de bário (100%) oferecidas em uma colher. A ordem das deglutições foi aleatória. Foram estudadas as fases oral e faríngea da deglutição, com registro de 30 quadros por segundo. Os pacientes com distonia laríngea apresentaram aumento de resíduos na região oral e em valécula e maior número de deglutições. Os pacientes apresentaram tempo de trânsito faríngeo (TTF) menor do que os controles (p<0,01), para os bolos nas consistências líquida e pastosa. O TTF foi menor após aplicação do que antes da aplicação da toxina botulínica, quando da deglutição do bolo pastoso. Portanto, concluiu-se que os pacientes com distonia laríngea, comparado a controles, têm trânsito mais rápido pela faringe, aumento de resíduos na região oral e em valécula e maior número de deglutições para o mesmo volume.Trinta dias após a aplicação da toxina botulínica foi observado diminuição da duração do trânsito pela faringe, com o bolo pastoso, e resposta tardia do movimento do osso hióide em relação à chegada do bolo na faringe. / Dystonia is a syndrome consisting of involuntary muscle contractions that result in distorted and repetitive movements and/or abnormal postures. Treatment may be by pharmacotherapy with anticholinergic drugs or with the injection of botulinum toxin in the affected muscle group. The aim of this study was to evaluate swallowing in patients with dystonia before and after treatment with botulinum toxin. Our hypothesis was that botulinum toxin modify the swallowing of patients with spastic dystonia. Seventeen adult subjects over the age of 18 years with clinically diagnosed dystonia were evaluated before and after treatment with botulinum toxin type A and compared to 20 healthy adults as controls. Participants underwent phonologic anamnesis and videofluoroscopy assessment of swallowing. Patients with dystonia were assessed before and 30 days after injection of botulinum toxin, guided by electromyography. In fluoroscopy, 6 swallows were evaluated of 5ml: 3 in a liquid consistency (100% barium sulfate) and 3 in a pasty consistency (3g of food thickener, ThickenUp Clear) in 50 mL of 100% barium sulfate, offered on a spoon. The oral and pharyngeal phases of swallowing were studied from swallows of random order, with registration of 30 frames per second. Patients with dystonia showed an increase of residue in the oral region and vallecula and greater number of multiple swallows. Patients had less pharyngeal transit time (PTT) than controls (p<0.01) for boluses of liquid and pasty consistencies. PTT was lower after the application of botulinum toxin than before with the swallowing of a pasty bolus. It was concluded that patients with dystonia, compared to controls, have more rapid transit through the pharynx, increased residues in the oral region and vallecula and a greater number of swallows for the same volume. Thirty days after the botulinum toxin, it was observed a shorter pharyngeal transit time with paste bolus, and delayed hyoid movement response to bolus presence in pharynx.
55

The Anatomy of Porcine and Human Larynges: Structural Analysis and High Resolution Magnetic Resonance Imaging of the Recurrent Laryngeal Nerve

Mason, Nena Lundgreen 01 November 2015 (has links)
The recurrent laryngeal nerve (RLN) innervates all the intrinsic muscles of the larynx that are responsible for human vocalization and language. The RLN runs along the tracheoesophageal groove bilaterally and is often accidentally damaged or transected during head and neck surgical procedures. RLN palsy and vocal cord paralysis are the most common and serious post op complications of thyroid surgeries. Patients who suffer from RLN injury can develop unilateral or bilateral vocal fold paralysis (BVFP). Theoretically, selective reinnervation of the posterior cricoarytenoid muscle would be the best treatment for BVFP. The phrenic nerve has been shown in several studies to be the best candidate to anastomose to the distal end of a severed RLN to restore glottal abduction. Successful PCA reinnervation has been sporadically achieved in both human patients and in animal models. Another notable ramification of recurrent laryngeal nerve injury is vocal instability caused by the alteration of mechanical properties within the larynx. In phonosurgery, alterations to the position and framework of the laryngeal apparatus are made to improve voice quality. Accurate and realistic synthetic models are greatly needed to predict the outcome of various adjustments to vocal cord tension and position that could be made surgically. Despite the sporadically successful attempts at PCA reinnervation, thus far, there are still several deficits in our anatomical familiarity and technological capability, which hinder the regularity of successful PCA reinnervation surgeries and our capacity to generate synthetic models of the human larynx that are both realistic and functional. We will address three of these deficits in this project using the porcine larynx as a model. Firstly, we will identify the anatomical variations of the porcine recurrent laryngeal nerve branches. A microscribe digitizer will be used to create three-dimensional mapping of the recurrent laryngeal nerve branches that are relevant to the posterior cricoarytenoid muscle and the abduction of the vocal folds. Secondly, we will develop a magnetic resonance imaging technique to correlate recurrent laryngeal nerve branching patterns with high-resolution MR images that can be used to determine the branching patterns present in a given specimen without surgery. Lastly, we will determine the distribution and composition of different tissue types found within human vocal folds. High resolution MRI, and Mallory's trichrome and H&E histological staining will be used to distinguish and identify the tissue composition of the vocal folds and surrounding laryngeal structures. Detailed information regarding vocal fold tissue composition and histological geometry will enable laryngeal modelers to select more sophisticated and life-like materials with which to construct synthetic vocal fold models.
56

Cricothyroid muscle activity at voicing transitions

Jaiswal, Sanyukta 01 May 2011 (has links)
Alteration in the tension or stiffness of the vocal folds, mediated by the cricothyroid (CT) muscle activation, is one of the laryngeal strategies attributed to devoicing during speech production. While some studies have reported a consistent increase in CT activity associated with voiceless sounds in comparison to their voiced cognates during speech (Kagaya & Hirose, 1975; Dixit & MacNeilage,1981; Lofqvist, McGarr & Honda, 1984; Löfqvist et al., 1989; Hoole et al., 2004), other studies have suggested that closer relation of CT activity to supra-segmental characteristics of the utterance rather than voicing contrasts (Hirose & Gay, 1972; Hirose and Ushijima,1978; Collier, Lisker, Hirose & Ushijima, 1979). The purpose of this study was to test the hypothesis that during intervocalic syllable production, CT muscle activity was consistently higher for voiceless sounds than their voiced cognates, to assist in vowel devoicing, when pitch, intensity, stress and aspiration were kept controlled. Simultaneous recordings of thyroarytenoid and cricothyroid muscle activity, video-nasendoscopy, and audio signals were obtained from eight, gender-matched adult speakers during intervocalic (VCV) syllable production. The speech sounds represented contrasts in manner of production including, plosives, affricates and fricatives with their voiced-voiceless and aspirated-unaspirated cognates Two voicing transition events were identified and marked on the EMG signals: Vowel-Consonant Transition (VC) and Consonant-Vowel Transition (CV).The mean amplitude of CT muscle activity during voicing transitions (VC, CV) was calculated over a 60 ms time window preceding the acoustic event. CT muscle activity was normalized to a percent of mean maximum activity and compared between voiced/voiceless and aspirated/unaspirated cognates across different categories of speech sounds, subjects and, VC and CV transitions. During the VC transition of intervocalic syllable production of voiceless and voiced speech sounds, a consistent increase in CT muscle activation was not observed across all subjects suggesting that CT activity is not essential for devoicing. Four of the eight subjects (M1, M4, F2, F3) showed consistently higher CT activity for voiceless than voiced sounds while, four of the eight subjects (M2, M3, F1, F4) either did not show any increase in CT muscle activity or showed an inconsistent pattern of increase. The magnitude of difference in CT activity between voiceless and voiced sounds ranged from 3-24% with the highest difference for voiceless fricatives, followed by voiceless aspirated stop plosives and voiceless affricates, and with least difference for unaspirated stop plosives. During consonant vowel (CV) transition of intervocalic syllable production seven of the eight subjects showed lower or comparable levels of CT EMG activity for voiceless speech sounds in comparison to their voiced cognates. Results of one-tailed unpaired t-test revealed that four of the eight participants, M1 [t (60.69) = 10.17, p < .001], M4 [t (8.88) = 57.03, p < .001], F2 [t (5.88) = 35.20, p < .001] and F3 [t (8.91) = 51.00, p < .001], showed significantly higher CT activity for the voiceless than voiced sounds during the VC transition of intervocalic syllable production but the results were not significant for subjects M2, M3, F1 and F4. No statistically significant difference was found between aspirated and unaspirated cognates for all the eight subjects on a two-tailed, unpaired t-test. No gender differences were observed in the findings.
57

Incomplete Neutralization and Task Effects in Experimentally-elicited Speech: Evidence from the Production and Perception of Word-final Devoicing in Russian

Kharlamov, Viktor 30 April 2012 (has links)
This dissertation investigates the role of grammatical versus methodological influences in the production and perception of final devoicing in experimentally-elicited speech from Russian. It addresses the question of how the partial preservation of the phonological voicing contrast in word-final obstruents is affected by (i) task-independent factors that reflect phonological and lexical properties of stimuli words (underlying voicing, word length, lexical competition) and (ii) task-dependent biases that arise due to the nature of the experimental task performed by the speaker (availability of orthographic inputs, presence of minimal pairs among the stimuli). Results of a series of acoustic production and perceptual identification tasks reveal that task-dependent factors account for the presence of robust and perceptually salient differences in the parameter of phonetic voicing. Several types of stimuli items also show limited but statistically significant differences in closure/frication duration and release duration that are independent of the presence of orthography or inclusion of full minimal pairs among test items. Taken together, these findings indicate that non-grammatical factors can play a prominent biasing role in both production and perception of the voicing contrast in experimentally-elicited speech, such that certain voicing-dependent cues are maintained only in the presence of task-dependent pressures. However, not all incompletely neutralized differences between phonologically voiced versus voiceless final obstruents can be attributed to the effects of orthography or inclusion of minimal pairs among the stimuli. In the theoretical domain, these results are argued to favour a less restrictive definition of neutralization and a model of phonology that views devoicing as a loss of the primary acoustic cue to the underlying voicing contrast rather than complete identity of the [voiced] feature.
58

Larynxmask : - en metod för att möjliggöra fri luftväg och adekvat ventilation / Laryngeal mask airway : - a method to secure the airway management and adequate ventilation

Björnstad, Maria, Karlsson, Linda January 2012 (has links)
Ofri luftväg kan uppstå på grund av bakåtfallen tunga hos den medvetslösa patienten eller om luftvägen blir tilltäppt av sekret, blod, maginnehåll eller främmande kropp. Att kunna säkerställa fri luftväg hos den medvetandesänkta patienten är en kompetens som varje anestesisjuksköterska måste behärska för att kunna säkerställa adekvat ventilation. Syftet med studien var att beskriva om larynxmask (LMA) är en patientsäker metod för att skapa fri luftväg och upprätthålla adekvat ventilation. Studien genomfördes som en litteraturstudie där 19 vetenskapliga artiklar analyserades. Resultatet av de granskade artiklarna gav följande fem teman; LMA är en säker metod för att skapa fri luftväg, LMA är en säker metod för att upprätthålla adekvat ventilation, personalens kompetens vid användning av LMA, aspirationsrisk vid användning av LMA med undertema LMA vid övervikt samt LMA vid elektiva- och akuta situationer. Litteraturstudiens resultat visar att LMA är en säker metod för att skapa fri luftväg och upprätthålla adekvat ventilation. Framtida studier skulle kunna belysa om LMA kan användas vid kirurgi till patienter med ökad aspirationsrisk, till exempel vid sectio och obesitaskirurgi. Studier skulle också kunna fokuseras på patienternas postoperativa upplevelser av att ha haft LMA jämfört med trakeal intubation. / Airway obstruction can in the case of an unconsciousness patient be caused by the tounge that falls back in the throat or by secretion, blood, stomach fluid or foreign body. The knowledge of airway management of the unconsciousness patient is a necessary qualification in every nurse anesthetist. The purpose of this study was to describe if laryngeal mask airway is a safe method to establish a secure airway and adequate ventilation. The study was performed as a literature study in which 19 articles were analysed. During the analyse five themes occurred: LMA is a secure way for airway management, LMA is a secure way to maintain adequate ventilation, the staff competence when using LMA, the risk of aspiration when using LMA with subtheme LMA in overweight and LMA in elective and acute situations. The result of the study shows that LMA is a secure way to establish a safe airway and adequate ventilation. Further studies could study if LMA can be used to elective patients with increased risk of aspiration, for example in cesarean and obesity surgery. Studies could also focuse on the patients´ postoperative experiences between LMA and tracheal intubation.
59

Role of Thoracic Vagal Branches in Regulation of Neurogenic Plasma Leakage in Rat Lower Airway

Lee, Yi-Chung 22 June 2001 (has links)
Vagal sensory afferent innervation corresponds to regulation of neurogenic inflammation in the airways. Capsaicin is mostly used for stimulation of sensory nerves that induce pain and inflammatory responses. It can specifically stimulate sensory afferent nerves, inducing neurogenic inflammation in the airways. According the past studies, we have found the right thoracic vagus nerve (RTVN) and right recurrent laryngeal nerve (RRLN); branches of right thoracic vagus trunk (RTVT) mediate different degree of neurogenic inflammation by intraenous injection of capsaicin (300 nmol/ml/kg). In order to investigate the innervation from the RTVN and RRLN of rat tracheobronchi and their involvement in plasma exudation, we injected 3 £gl of capsaicin (10 mg/ml) into RTVT and denervated the RRLN or RTVN and used India ink as tracer dye to label the leaky microvessels. Our observation indicated that injection of capsaicin into the RTVT coud induce obvious plasma exudation in trachea (area density of leaky blood vessels was about 22%), but plasma exudation was significantly decreased after denervation of RRLN. The left upper side of trachea was decreased by 77.6% and the right upper side decreased by 84.5%. This phenomenon was not caused by denervation of RTVN. The results suggest that vagal nerve innervation of upper trachea mostly came from the RLN. Otherwise, capsaicin injection into the RTVT also induced neurogenic inflammation in the larynx. Experimental denervation of both superior and recurrent laryngeal nerves resulted in a decrease of plasma extravasation by 84.98%. Denervation of either RTVN or RRLN also decreased the plasma extravasation in the larynx. The evidence suggest that sensory fibers in the superior laryngeal nerve, recurrent laryngeal nerve, and thoracic vagus nerve might come from the same population of vagal ganglion sensory neurons.
60

Are Respiratory Behaviors Affected in Individuals With Adductor Spasmodic Dysphonia?

Biedess, Katie 01 June 2006 (has links)
Adductor spasmodic dysphonia (ADSD) is a focal dystonia that is characterized by voice breaks due to involuntary contractions of the adductor muscles of the vocal folds. These spasms can interfere with the coordination and balance of the respiratory and phonatory systems interfering with normal voice production. Disruptions in normal respiratory behaviors are well documented in inviduals with laryngeal disorders, including ADSD. Previous research regarding respiratory processes in ADSD has focused on airflow and pressure; however, there are many other parameters that have not been considered and may shed new light on the respiratory behaviors of individuals with ADSD. Therefore, the current pilot study attempted to determine if individuals with ADSD differed from controls in various breathing parameters while engaged in conversational and reading tasks.Thirty individuals were tested; fifteen in the ADSD group and fifteen in the age- and gender-matched control group. Respitrace, an inductive plethysmography device, calculated 14 different respiratory measures related to volume, timing, thoracic displacement and respiratory efficiency. The results of the study indicated that various significant differences existed between groups. Those with ADSD were found to have statistically higher ventilation rates, a greater frequency of breaths per minute, a higher degree of muscular inefficiency/breathlessness and labored breathing. These results indicated that individuals with ADSD suffered from disordered breathing due to the neurologically related obstruction at the level of the larynx. Differences according to task were also found. Specifically, the rib cage contributed to a lesser extent in voice production and the participants utilized longer inspiratory times, exhaled a larger volume of air and took longer to reach peak expiratory flow during conversational tasks when compared to reading tasks. These differences were attributed to a higher cognitive-linguistic demand required during conversational speech. Overall, the results of this study have many clinical implications. Most importantly, these findings support the idea that individuals with ADSD may experience difficulties with respiration as the effects of their Botox injection begin to wear off. Further research is needed with regards to the effects laryngeal spasms have on other respiratory behaviors.

Page generated in 0.0569 seconds