Skeletal muscle contractions emit a low frequency sound (<100Hz) that can be detected by vibromyography (VMG) or mechanomyography (MMG). The aim of this study was to determine the future application of the VMG signal as a clinical tool in reflecting the physiological state or function of muscle during rehabilifation and diagnosis. In order to achieve this aim, the following was investigated. A) The technical characteristics: Three different transducers (the capacitance and piezoelectric accelerometers and the contact sensor) and the transducer/ amplifier system. B) The repeatability of the VMG signal at different force levels. C) Physiological characteristics of the VMG signal comparing 'normal' and 'abnormal' muscle function. Past studies on VMG have revealed that these three areas have received little attention. The VMG signal was taken from the biceps brachii muscle at different contraction levels 10%, 50% and 80% maximum voluntary contraction (MVC) for within day (n=3) and between day (n=17) recordings. The signal from asymptomatic (n=29) and symptomatic (n=23) low back pain subjects was then compared. Recordings were taken from the erector spinae muscle at an incremental increase in voluntary contraction (10%-100%MVC). These recordings were repeated on the next day. Results from this study have revealed the following: A) Technical characteristics : the lower cut-off frequency is important and insufficient attention in past studies has been given to the transducer-amplifier system. Additionally, the capacitance accelerometer was the favoured transducer due to its greater sensitivity to low frequencies, simplicity of use and ease of stabilising and coupling techniques to the skin. B) Repeatability of the VMG signal: For successive recordings, compared with precision (%C.O.V and L.O.A) and reliability (I.C.C), correlation (r value) of the VMG signal appears a much stronger and a more consistent statistic in the time and frequency domains. C) Physiological Characteristics: Although having a high individual variation, the erector spinae demonstrated a strong curvilinear relationship with increasing submaximal voluntary contraction (%MVC) reflecting the recruitment and rate coding strategies for this muscle. The VMG RMS for symptomatic low back pain subjects was considerably less than asymptomatic subjects suggesting a deficiency in muscle function. In contrast, the PSD was less favourable in distinguishing between the two subject groups. Reasons for these findings are discussed. In future, the clinical application of the VMG RMS values may quantitatively assess paraspinal muscle force reflecting physiological changes in recruitment and rate coding strategies in 'normal' and 'abnormal' muscle function during rehabilitative care.

No description available.

Sammanfattning: Ljudlokalisering är en viktig hörselfunktion och fungerar bäst med en god binaural hörsel. För att kunna lokalisera ljud använder hörselsystemet ett antal faktorer. Vid en sensorineural hörselskada påverkas förmågan att uppfatta de här faktorerna. Syftet med studien var att förklara de faktorer som inverkar vid ljudlokalisering och hur riktningshörseln påverkas vid en sensorineural hörselskada. Det här utfördes genom att granska och sammanställa aktuell forskning i en forskningsöversikt. Resultatet visar att de viktigaste faktorerna vid ljudlokalisering i det horisontella och vertikala planet är interaural tidsskillnad, interaural styrkeskillnad och olika spektrala faktorer. Andra faktorer av vikt vid ljudlokalisering är ljudets amplitud, konkurrerande ljud, ljudkällans placering och avståndet till ljudkällan. Vid avståndsbedömning är den viktigaste akustiska faktorn ljudets amplitud, men de spektrala faktorerna har en viss inverkan även här. Resultatet visar att sensorineuralt hörselskadade personer överlag har en sämre förmåga att tillgodogöra sig de akustiska faktorer som påverkar lokalisering av ljud jämfört med normalhörande personer.

The joint between the arytenoid cartilage and the cricoid cartilage is one of the smallest in the body. Its existence has been known since, if not before, the time of Galen (130-201 A.D.). However, little anatomical study has been carried out on this synovial joint and publications based on research into its exact anatomy and function are few. The results of these studies have been rarely questioned or scientifically re-examined, with the consequence that authoritative anatomical texts have perpetuated unconfirmed ideas of the behaviour of the cricoarytenoid joint. The purpose of this thesis is to present in detail the results of research into the anatomy and the functions of the cricoarytenoid joint and of the muscles that act upon it. This research began in 1977 with the dissection of 45 cadaver larynges. In this initial study the most striking anatomical finding was the identification of the so-called "posterior" cricoarytenoid ligament, of which inadequate and often incorrect detail has been presented in standard anatomy texts. Another surprising finding of this work was the variability of the shape and positions of the two cricoid facets. In 1978 these findings were published in detail (Sellars and Keen). An attempt to understand the accepted muscular control of the cricoarytenoid joint led to further research. This was carried out by the dissection of a further 23 larynges, with special care to examine the exact origin, direction and insertion of each muscle concerned. Six of these larynges, which had been surgically excised, were also stimulated electrically immediately after excision and the resultant arytenoid cartilage movements were recorded and analysed. The findings of this study were published in 1978 (Sellars) and these articles (Sellars and Keen, 1978; Sellars, 1978) are referred to in "Gray's Anatomy" and in Grant's "Method of Anatomy" (Sellars and Keen, 1978). Further examination of the reactions of these intrinsic laryngeal muscles to electrical stimulation has since been done on three additional fresh operative specimens. This additional work on laryngeal muscle action suggests that the explanation of specific intrinsic laryngeal muscle actions made in the earlier publication (Sellars, 1978) had been oversimplified. The main experimental work, on which this thesis is based, attempts to clarify and interpret the highly complex synchronized muscle actions that occur at the cricoarytenoid joint. Relevant facts found in both recent and old publications relating to this subject are presented and discussed. Before the review of literature is presented the embryology and basic anatomy of the larynx are described.

<p>Radioimmunotherapy (RIT) has been shown to be a practicable way to treat head and neck squamous cell carcinoma. A specific antibody recognizes the charasteristic structure of tumour cells when loaded with cytotoxic agents (toxins, drugs, radionuclides, etc). But RIT kills not only tumour cells with attached radionuclides but also adjacent tumour cells due to the “cross fire effect”. To be efficacious, RIT depends closely on suitable monoclonal antibody, on the properties of the chosen radionuclides, and on a suitable labelling method for attaching radionuclide to antibody. </p><p>In this study we initially used radionuclide-labelled cMAB U36, via linker DABI in order to improve the retention of radio-conjugates in the tumour cells. Improved retention is important because the longer the radionuclide remains in tumour cells, the more effective will the tumour cells be eradicated. In the investigation, both normal mice and HNSCC-bearing nude mice were used to compare our form of treatment against other radio-iodination methods. In the biodistribution study, normal mice showed that radioactive uptake in organs diminished with time, irrespectively of whether the conjugate was directly or indirectly labelled. But in thyroid, there was a tenfold greater accumulation of direct-labelled than of indirectly labelled conjugate.</p><p>In tumour-bearing nude mice, by contrast, the results showed promising uptake of radioactivity, but little uptake in direct-labelled conjugate in thyroid. Significant differences were observed on comparing tumour: organ ratios between 131I-cMAb U36 vs. 125I-DABI-cMAb U36.</p><p>In the present study, cMAb U36 labelled with 211Astatine was initially used to treat HNSCC in nude mice. The biodistribution of 211At-cMAb U36 did not reveal any significant difference between an antibody-blocked group and a non-blocked group. But it did highlight the characteristics of a successful targeting conjugate in HNSCC-bearing nude mice.</p><p>In the subcutaneous therapy experiment, most of the treated tumours (n=18) had disappeared by the 26th day, in both U36-blocked and non-blocked groups. Treatment in the intravenous therapy experiment had also proved effective. In the antibody non-blocked group, the smallest tumour volume was 25 mm3 (average 111 mm3) vis-á-vis 65 mm3 (average 145 mm3) in the blocked group. None of tumours grew again following treatment.</p>

Radioimmunotherapy (RIT) has been shown to be a practicable way to treat head and neck squamous cell carcinoma. A specific antibody recognizes the charasteristic structure of tumour cells when loaded with cytotoxic agents (toxins, drugs, radionuclides, etc). But RIT kills not only tumour cells with attached radionuclides but also adjacent tumour cells due to the “cross fire effect”. To be efficacious, RIT depends closely on suitable monoclonal antibody, on the properties of the chosen radionuclides, and on a suitable labelling method for attaching radionuclide to antibody. In this study we initially used radionuclide-labelled cMAB U36, via linker DABI in order to improve the retention of radio-conjugates in the tumour cells. Improved retention is important because the longer the radionuclide remains in tumour cells, the more effective will the tumour cells be eradicated. In the investigation, both normal mice and HNSCC-bearing nude mice were used to compare our form of treatment against other radio-iodination methods. In the biodistribution study, normal mice showed that radioactive uptake in organs diminished with time, irrespectively of whether the conjugate was directly or indirectly labelled. But in thyroid, there was a tenfold greater accumulation of direct-labelled than of indirectly labelled conjugate. In tumour-bearing nude mice, by contrast, the results showed promising uptake of radioactivity, but little uptake in direct-labelled conjugate in thyroid. Significant differences were observed on comparing tumour: organ ratios between 131I-cMAb U36 vs. 125I-DABI-cMAb U36. In the present study, cMAb U36 labelled with 211Astatine was initially used to treat HNSCC in nude mice. The biodistribution of 211At-cMAb U36 did not reveal any significant difference between an antibody-blocked group and a non-blocked group. But it did highlight the characteristics of a successful targeting conjugate in HNSCC-bearing nude mice. In the subcutaneous therapy experiment, most of the treated tumours (n=18) had disappeared by the 26th day, in both U36-blocked and non-blocked groups. Treatment in the intravenous therapy experiment had also proved effective. In the antibody non-blocked group, the smallest tumour volume was 25 mm3 (average 111 mm3) vis-á-vis 65 mm3 (average 145 mm3) in the blocked group. None of tumours grew again following treatment.

This thesis describes the development of a novel game-like method, the AnimalSeek method, which can be used, along with motion tracking technology, to measure localisation ability of a child under five years of age. For the game-like task to be successful, a high number of responses (in particular correct head turn responses) was required. Previous studies, although not all looking at localisation ability, have used many different techniques to obtain the maximum number of responses from a child. The children were engaged inside a custom-built environment inside an anechoic chamber. Three large video screens onto which backgrounds and animated characters were projected and manipulated and used to engage the child in the game-like task. Behind the video screens were loudspeakers from which the auditory stimulus where presented. A correct response to the auditory stimulus i.e. a head, hand or eye movement towards the target speaker was rewarded with a animated character presented on the screens (incorrect responses were presented with a static character). The location of the reward in relation to the auditory stimulus was a point of interest and was investigated to see how it affected the number of responses. The method shows it was possible to engage the child with the visual environment and obtain responses, however, the results showed generally fewer head turn responses than expected, especially in the younger age groups. Motion tracking technology was used to measure the localisation ability of the children, as well as measuring the responses, the motion tracking data was used and programs developed which could automatically classify the responses the children made to the sounds. The thesis has shown that it is possible to devise a new method which can be used to engage the child in the task and extract and classify their responses to auditory stimuli in order to measure their localisation ability.

Experimental meningitis was induced in pigmented guinea pigs by subarachnoid inoculation of \(1 \times 10^9\) Escherichia coli K-12 or \(3 \times 10^7\) CFU Streptococcus pneumoniae serotype 2 D39 (NCTC 7466) or PLN-A, \(\Delta\)NA1 or \(\Delta\)HY1, defined isogenic derivatives of D39 deficient in pneumolysin, neuraminidase or hyaluronidase respectively. All animals developed a meningeal inflammatory response and a labyrinthitis. Hearing loss in pneumococcal meningitis was measured by recording the evoked auditory nerve compound action potential from the round window membrane. Animals infected with PLN-A sustained significantly less hearing loss than those infected with wild-type D39 (12 dB vs. 50 dB 12 h post inoculation; P<0.0001), Neuraminidase deficiency did not alter the course of the meningeal inflammatory response nor affect hearing loss. The \(\Delta\)HY1 mutant survived poorly in the cerebrospinal fluid and blood but still caused hearing loss. Both pneumococcal and E. coli meningitis induced specific ultrastructural lesions in the organ of Corti as judged by high-resolution scanning and transmission electron microscopy, and these lesions were most severe with pneumolysin-sufficient pneumococcal infection. Microperfusion of \(5\times10^6\) CFU S.pneumoniae D39 directly into the scala tympani of guinea pigs also resulted in electrophysiological and ultrastructural damage to the organ of Corti that could be diminished by pretreatment with antibiotics. The data confirm the cochlea as the site of meningogenic deafness. They suggest that pneumolysin expression is chiefly responsible for meningogenic deafness and that if pneumococci invade the inner ear during bacterial meningitis, cochlear deafhess will rapidly ensue.

The vestibular system provides vital information about head position and motion; which is used for the control of balance through vestibulospinal reflexes. Chapter 2 explores the process of transforming head position to body coordinates, with and without vision. The results show when vision is available, the evoked response is less precise. Chapter 3 explores the transformation process before and after 60 days of bedrest. After this period of inactivity, participants swayed more, and their EVS-evoked sway response was less precise. This decrement in precision appears to begin recovery 6 days postbedrest. Chapter 4 focuses on vestibulo-ocular reflexes rather than postural reflexes. Electrical vestibular stimulation is used to evoke measurable torsional eye-movements. The magnitude of the response is modulated by stimulus frequency. Results suggest that CNS interprets electrical vestibular stimulation as a velocity signal rather than a position or acceleration signal. This technique is an ideal measure of pure vestibular function, Chapter 5 utilised the technique in a clinical environment. Vestibular schwannoma patients, with known unilateral vestibular deficit, were tested to identify if the proposed technique can detect this deficit. Results showed that asymmetries could be detected, and, the test may be more sensitive than previously used measures of vestibular asymmetries.

Objective: To follow a cohort of children from age 4-6-12 with respect to sleep disordered breathing (SDB) and orofacial development. Questionnaires were completed about sleep, snoring, apneas, enuresis, sucking habits, and adenotonsillar surgery and, from age 12, about allergies, asthma, and general health. Children snoring regularly had an ENT- examinations including sleep studies (at ages 4 and 12) and an orthodontic evaluation. Development of biometric data in snoring children and not snoring controls was studied in relation to adenotonsillar surgery. Result: Of the original group of 615 children, 509 (83%) participated at age 6 and 393 (64%) at age 12. 27 snored regularly and 231 did not snore at age 12. Differences between groups were seen on all answers. From age 4–12 the prevalence of OSA decreased from 3.1% to 0.8%, and the minimum prevalence of snoring regularly from 5.3% to 4.2%. The odds for a child who snored regularly at four or six to be snoring regularly at age 12 was 3.7 times greater than for a not snoring child in spite of surgery (OR 3.7, 95% CI 2.4-5.7). 63 children were operated for snoring by age 12, of them 14 never snored and 17 snored regularly at age 12. Cross-bite was more common among snoring children at ages 4, 6 and 12 as was a narrower maxilla. In most cases, surgery cured the snoring temporarily, but the maxillar width was still smaller by age 12—even when nasal breathing was attained. Children snoring regularly at age 12, operated or not operated, showed long face anatomy and were oral breathers; the seven cases who were not operated and the five who were still snoring in spite of surgery, did not have reduced maxillary arch width. Conclusion: The prevalence of children snoring regularly is about the same from age four to twelve in a cohort where adenotonsillar surgery has been performed on obstructed cases, but the prevalence of OSA decreases considerably. The children snoring regularly have a more narrow maxilla compared to children not snoring—a condition that is not changed by adenotonsillar surgery regardless of symptom relief.