Biomedical subjects
Publications and source records attributed to K Robinson.
Before evaluation of the efficacy of voice therapy is possible it is necessary to define established practice. The aim of this study therefore was to assess the prevailing treatment strategies among UK voice therapists for commonly presenting causes of dysphonia.
BACKGROUND: A high level of total plasma homocysteine is a risk factor for atherosclerosis, which is an important cause of death in renal failure. We evaluated the role of this as a risk factor for vascular complications of end-stage renal disease. METHODS AND RESULTS: Total fasting plasma homocysteine and other risk factors were documented in 176 dialysis patients (97 men, 79 women; mean age, 56.3 +/- 14.8 years). Folate, vitamin B12, and pyridoxal phosphate concentrations were also determined. The prevalence of high total homocysteine values was determined by comparison with a normal reference population, and the risk of associated vascular complications was estimated by multiple logistic regression. Total homocysteine concentration was higher in patients than in the normal population (26.6 +/- 1.5 versus 10.1 +/- 1.7 mumol/L; P < .01). Abnormally high concentrations (> 95th percentile for control subjects, 16.3 mumol/L) were seen in 149 patients (85%) with end-stage renal disease (P < .001). Patients with a homocysteine concentration in the upper two quintiles (> 27.8 mumol/L) had an independent odds ratio of 2.9 (CI, 1.4 to 5.8; P = .007) of vascular complications. B vitamin levels were lower in patients with vascular complications than in those without. Vitamin B6 deficiency was more frequent in patients than in the normal reference population (18% versus 2%; P < .01). CONCLUSIONS: A high total plasma homocysteine concentration is an independent risk factor for atherosclerotic complications of end-stage renal disease. Such patients may benefit from higher doses of B vitamins than those currently recommended.
The purpose of this study was to determine the long-term outcome of patients with bundle branch block (BBB) who have no clinical evidence of cardiovascular disease. Among 110,000 participants in a screening program, 310 subjects with BBB without apparent of suspected heart disease were identified. Their outcome after a mean follow-up of 9.5 years was compared with that of 310 similarly screened age- and sex-matched controls. Among the screened population, isolated right BBB was more prevalent than isolated left BBB (0.18% vs 0.1%, respectively; p<0.001), and the prevalence of each abnormality increased with age (p<0.001). Total actuarial survival was no different for those with left BBB or right BBB and their respective controls. Cardiac mortality, however, was increased in the left BBB group when compared with their controls (p=0.01, log rank test). Left BBB, but not right BBB, was associated with an increased prevalence of cardiovascular disease at the follow-up (21% vs 11%; p=0.04). In the absence of clinically overt cardiac disease, the presence of left BBB or right BB is not associated with increased overall mortality. Isolated left BBB is associated with an increased risk of developing overt cardiovascular disease and increased cardiac mortality.
Homocysteine is increasingly recognized as a risk factor for coronary artery disease. An understanding of its metabolism and of the importance of vitamins B6 and B12 and folate as well as enzyme levels in its regulation will aid the development of therapeutic strategies that, by lowering circulating concentrations, may also lower risk. Possible mechanisms by which elevated homocysteine levels lead to the development and progression of vascular disease include effects on platelets, clotting factors and endothelium. This review presents the clinical and basic scientific evidence supporting the risk and mechanisms of vascular disease associated with elevated homocysteine concentrations as well as the results of preliminary therapeutic trials.
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Bilateral chylothorax following thoracic duct injury is a rare occurrence. Since 1907 there have been only six reports in the literature of this potentially serious complication. We report a case of bilateral chylothorax following ligation of the cervical thoracic duct during a left subclavian to carotid artery transposition.
Neurocognitive studies of multiple sclerosis (MS) have identified a robust long-term memory deficit. We hypothesized that this is due in part to the limited representation and use of serial order information. MS patients and controls were studied with a supraspan list learning procedure with post-encoding retrieval and recognition trials. MS patients demonstrated post-encoding negative recency with normal recognition, and word order recall was impaired. These findings appear to be in part to difficulty using temporal order cues in long-term memory. Two dissociable memory deficits were identified, suggesting that there are at least two neurocognitive mechanisms underlying memory impairment in MS.
OBJECTIVES: A new type of coated stent, consisting of a conventional stent covered by an autologous vein graft, was developed at our institution. BACKGROUND: Coated stents are under investigation to address stenting limitations. However, experimental implantation of coated stents covered by autologous tissue has not been reported. METHODS: An autologous vein graft was removed and carefully prepared. Subsequently, a Palmaz stent was covered by the vein graft both internally and externally. Twenty-seven stents were implanted in the normal iliac arteries of 27 pigs weighing 18 to 33 kg. In 15 of the pigs, 15 noncoated Palmaz stents were implanted in the contralateral artery; these animals served as the control group. The animals were followed up angiographically for a period ranging from 7 days to 6 months. At the time of death, the stented segments were removed, and histomorphometric analysis was performed. RESULTS: Autologous vein graft-coated stent preparation and implantation was feasible and uncomplicated. In both stents, angiographic follow-up revealed the absence of thrombosis, except for two cases of subacute thrombosis in the control group. The thickness of the intimal layer was greater in the coated stents and seems to be due to the existence of the internal vein layer ([mean +/- SD] 0.57 +/- 0.12 vs. 0.27 +/- 0.13 mm, p = 0.001). The arterial media of the coated stent segments was thinner than that in the control group (0.14 +/- 0.03 vs. 0.18 +/- 0.01 mm, p = 0.02). CONCLUSIONS: The autologous vein graft-coated stent seems to be nonthrombogenic, and only minimal hyperplasia was observed in the pigs. Further studies are needed to explore the efficacy of this technique in humans.
OBJECTIVE: Establish the test-retest reliability of loudness scaling using a bounded category rating method. DESIGN: The individual loudness functions were investigated in three groups of listeners: seven normal-hearing listeners age 18 to 35 yr, five normal-hearing listeners aged 57 to 84 yr, and five listeners aged 54 to 82 yr with bilateral sloping sensorineural hearing loss. Test-retest reliability was investigated by determining the intralistener, between-session standard deviation. RESULTS: The pattern of test-retest reliability was similar across all three groups. It improved as the intensity of the stimulus increased: 7 dB at the first quartile of the loudness function, and 3 dB at the third quartile. Two to four runs of the task appear to be sufficient to obtain a stable loudness function, and it was shown that an exponential function provided a better goodness of fit than a linear function (r2: 0.99 compared with 0.94). CONCLUSIONS: Loudness scaling is a longer test than most conventional suprathreshold measures and requires special equipment. However, it has good test-retest reliability and provides more information on the loudness function that might be useful in the fitting of nonlinear hearing aids. The data show that an exponential function provides a good fit to the loudness growth data, and should probably be incorporated into fitting algorithms associated with loudness scaling.
We describe a theoretical framework that distinguishes stimulus, procedural, and task aspects of learning, and we suggest that this framework may allow an improved understanding of acclimatization and late-onset auditory deprivation. We review the literature on learning after sensorineural hearing loss and after the provision of amplification. We then examine the possibility of using training to improve the speech-understanding skills of listeners with sensorineural hearing loss after provision of amplification. Here, we concentrate on techniques recently demonstrated to encourage the acquisition of non-native phonetic contrasts in second-language learners. We argue that there are three general principles associated with auditory learning and training: 1) the more complex the task, the longer the learning period required; 2) the greater the similarity between training and test tasks, the greater the transfer of training; and 3a) the more familiar the stimulus materials, the faster the subsequent learning. When training for speech identification in everyday life, maximizing the opportunity for the listener to cope with the acoustic variability found in natural speech, both within and between talkers, is important. We, therefore, argue that the third principle should be extended: 3b) the more the training set exemplifies the acoustic variability found within and between talkers, the greater the transfer to open-set speech identification in everyday life. Throughout the review, we show that individual differences in learning are observed in the rate of acquisition and in the level of asymptotic performance. We argue that it is possible to postulate modulators of learning that may account for some of these individual differences. Possible candidates for influential modulators are: 1) the history of hearing impairment--the longer the history, the longer the time taken to improve performance and, possibly, the lower the asymptotic level of performance; 2) the severity and pattern of hearing loss; 3) the degree of asymmetry in the hearing loss and its effect on the binaural organization of the hearing system; and 4) the level of patient adaptability and cognitive abilities, such as attentional control and short-term memory span.
The terminology used in studies documenting changes in auditory performance following fitting of hearing aids has been diverse. Definitions for the auditory deprivation effect and auditory acclimatization are offered as a first step in rationalization. Two statements summarize current knowledge concerning auditory deprivation effects and auditory acclimatization, as well as considering the potential implications for research, field trial and clinical practice applications. Potential areas for future research are identified.
Pyriform sinus cancer remains one of the most lethal of human diseases. Regardless of approach attempted significant enhancement of survival has not been realized. In this study a retrospective single institutional review of all patients diagnosed with pyriform sinus cancer during the 1980s was conducted. The results in 93 patients show an overall determinant 5-year survival of 14.3%. Of patients undergoing surgery, median determinant survival was 37 months and 5-year survival was 34.6%. In resectable patients treated with radiation with or without chemotherapy, median determinant survival was 13 months with 5-year survival of 7.1% (P < .01). Surgical salvage was attempted in 8 patients without success. In conclusion, due to the apparent survival advantage for surgical patients, the low rate of surgical salvage, and the relatively low rate of organ preservation in prospective trials, pyriform sinus cancer is a poor site for organ preservation. Surgery followed by radiation therapy should remain the standard of care for pyriform sinus cancer.
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The resistance or susceptibility of mice to infection with the intestinal nematode parasite Trichuris muris is closely correlated with polarization of T helper (Th) cell responses to the type 2 (Th2) or type 1 (Th1) subset. Comparison of infections with three isolates of T. muris (E/K, E/N, and S) in three inbred strains of mice (CBA, C57BL/10, and B10.BR) has shown that host Th response phenotype can be parasite determined. Although the mouse strains used show genetically determined variation in ability to respond to T. muris (CBA > C57BL/10 > B10.BR), the speed of worm expulsion in a given strain depended upon the isolate used for infection (E/K > E/N > S). The two isolates that induced the most effective resistance (E/K and E/N) elicited parasite-specific host antibody responses that were dominated by immunoglobulin G1 (IgG1), and antigen-stimulated T cells from infected mice released interleukin-5 in vitro. With the isolate that induced the least host resistance (S), the dominant antibody response was IgG2a, and T cells released gamma interferon in vitro. These data show clearly that parasite variant-specific factors play a major role in Th subset polarization during infection.
Standard treatment for the majority of malignant brain tumours consists of surgery and radiotherapy. This treatment has late morbidity which is accentuated in the very young child. As part of a strategy to improve quality of life and overall survival of young children with brain tumours, members of the United Kingdom Children's Cancer Study Group (UKCCSG) have piloted an intensive chemotherapy regimen which aims to avoid or delay radiotherapy following surgery. Twenty eight children with a variety of malignant brain tumours have received the regimen, which contains carboplatin, vincristine, cyclophosphamide, methotrexate, and cisplatin. The treatment is toxic, resulting in one death from infection. The bulk of the toxicity was associated with the administration of carboplatin. All but three children eventually required adjuvant radiotherapy and this was given between 1.5 and 27 months from diagnosis (median delay to radiotherapy, 12 months). Using this treatment regimen, overall survival at four years is 35% (confidence intervals 10% to 60%). While there is no evidence from this study that radiotherapy can be abandoned in the management of malignant brain tumours, its introduction may be delayed using suitable chemotherapy, thus allowing time for further CNS development. This treatment strategy has been taken forward as an international clinical trial run through the International Society for Paediatric Oncology, but using a smaller dose of carboplatin to reduce toxicity.
The Glasgow Benefit Inventory (GBI) is a measure of patient benefit developed especially for otorhinolaryngological (ORL) interventions. Patient benefit is the change in health status resulting from health care intervention. The GBI was developed to be patient-oriented, to be maximally sensitive to ORL interventions, and to provide a common metric to compare benefit across different interventions. The GBI is an 18-item, postintervention questionnaire intended to be given to patients to fill in at home or in the outpatient clinic. In the first part of the paper, five different ORL interventions were retrospectively studied: middle ear surgery to improve hearing, provision of a cochlear implant, middle ear surgery to eradicate ear activity, rhinoplasty, and tonsillectomy. A criterion that was specific to the intervention was selected for each study, so that the patient outcome could be classified as above and below criterion. In all five interventions, the GBI was found to discriminate between above- and below-criterion outcomes. The second part of the paper reports on the results and implications of a factor analysis of patient responses. The factor structure was robust across the study, and so led to the construction of subscales. These subscales yield a profile score that provides information on the different types of patient benefit resulting from ORL interventions. The GBI is sensitive to the different ORL interventions, yet is sufficiently general to enable comparison between each pair of interventions. It provides a profile score, which enables further breakdown of results. As it provides a patient-oriented common metric, it is anticipated that the GBI will assist audit, research, and health policy planning.
Expulsion of T. spiralis adult worms was accelerated in high-responder NIH mice vaccinated previously with complete Freund's adjuvant (CFA) emulsified in PBS, whereas the expulsion of this parasite from low-responder C57 BL/10 mice was unaffected. Incomplete Freund's adjuvant (IFA) did not induce protection and it was concluded that the mycobacterial component, present in CFA but absent from IFA, was responsible for inducing these non-specific protective effects. CFA did not induce T. spiralis-specific B- or T-cell responses, but high levels of IFN gamma from Con A-stimulated mesenteric lymph node cells of CFA-vaccinated NIH mice were detected. Such cytokine release was not produced by cells from the C57 BL/10 strain. It is therefore proposed that IFN gamma production is related to the mode of adjuvanticity and non-specific protective effects of CFA in this system.
It is standard practice for most rhinoplasty surgeons to assess what they perceive to be the cosmetic outcome of their surgery. There have, however, been few attempts to gauge the degree of success of rhinoplasty from the patient's perspective. The aim of this study was to measure the benefit of rhinoplasty in an unselected group of patients who had undergone this procedure under the National Health Service (NHS). Two hundred and twenty-four patients who had undergone rhinoplasty or septorhinoplasty in the Department of Otolaryngology at Glasgow Royal Infirmary from 1990 to 1994 were surveyed by post; two questionnaires were administered. The Glasgow Benefit Inventory has four subscales which assess the patient's perception of the success of surgery, and the influence of surgery on the patients physical health, psychosocial function and social interaction. The Nasal Symptom Questionnaire (Fairley et al., 1993)--previously validated as an outcome measure in the context of FESS--was used to assess nasal symptoms. Multivariate and factor analysis was used to analyse the results. Four factors were extracted from the 103 responses to the Glasgow Benefit Inventory. The major factor of the benefit score was perception of surgical success which explained 50% of the variance. Three other factors (improvements in psychosocial functioning, social interaction and physical health after surgery) accounted for 10%, 5%, and 6% of the variance, respectively. Analysis of the Nasal Symptom Questionnaire yielded one predominant factor which was inversely related to perceived benefit. The outcome of rhinoplasty is influenced by the presence of nasal symptoms. Greater attention to nasal function would increase the benefit of rhinoplasty.