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Biomedical subjects

M Birchall

Publications and source records attributed to M Birchall.

8 recordsLinked to original sources
PubMed2001

Comparative study of the laryngeal innervation in humans and animals employed in laryngeal transplantation research.

Laryngeal transplantation is receiving increased attention. Re-innervation of the transplanted larynx is critical for a successful functional outcome. Different anatomical models (dog, cat, rat, pig) have been employed for experimental purposes. Interspecies similarities and differences are important for extrapolating the experimental results to humans. We present a review of the anatomical course and regional branching patterns of the laryngeal nerves in both humans and animals currently being employed in laryngeal transplantation. The clinical and surgical implications are also discussed.

Animals↗
PubMed2000

Raman spectroscopy for early detection of laryngeal malignancy: preliminary results.

OBJECTIVE: Raman spectroscopy, the analysis of scattered photons after monochromatic laser excitation, is well established in nonbiological sciences. Recently this method has been used to differentiate premalignant and malignant lesions from normal tissue. Its application for early diagnosis has been explored in a variety of sites (e.g., esophagus, cervix), but not, to date, in laryngeal cancer. The objective of this study was to perform a feasibility study of the use of Raman spectroscopy for early diagnosis of laryngeal malignancy. METHODS: Biopsy specimens were snap-frozen, and top sections were sent for histopathological analysis. Only homogenous samples with clearly defined pathological findings were used in this study: seven histologically normal samples, four exhibiting dysplasia, and four with carcinoma. Samples were defrosted and placed under a Renishaw (Wotton-Under-Edge, UK) System 1000 Raman microspectrometer for analysis. Between 5 and 12 spectra were acquired from each sample, with an excitation wavelength of 830 nm. Average characteristic spectra for each disease or condition were compared. Further multivariate statistical analysis of the data was carried out to evaluate and maximize the differences in the spectra for each disease or condition. RESULTS: The most visible differences in the spectra occur between 850 and 950 cm(-1) and 1,200 and 1,350 cm(-1). The later peaks are directly related to protein conformation and C-H bond stretch in nucleic acid bases. The relative intensity of the nucleic acid peak increases with progression to malignancy. Use of linear discriminant analysis made it possible to separate the spectra with disease to a greater degree of accuracy than using empirical peak ratio methods alone. Classification results obtained from cross-validation of the discriminant model showed prediction sensitivities of 83%, 76%, and 92% and specificities of 94%, 91%, and 90% for normal, dysplastic, and squamous cell carcinoma of the larynx, respectively. CONCLUSIONS: There was strong evidence to support spectral identification of malignancy and earlier abnormal changes. More substantive studies of the spectral differences between malignant and non-neoplastic tissue are warranted. Raman spectroscopy may become a useful adjunct to pathological diagnosis allowing directed or guided biopsies and assessment of adequacy of resection margins.

Adolescent↗
PubMed1999

Medical students in ENT outpatient clinics: appointment times, patient satisfaction and student satisfaction.

OBJECTIVES: Outpatient clinics are increasingly important in medical education. The effect of students on clinic times and patient satisfaction, as well as their own satisfaction, were studied. DESIGN: A prospective, non-randomized, controlled study using adult patient questionnaires, medical student questionnaires and clinic time sheets. SETTING: Two teaching hospital ENT clinics. SUBJECTS: Medical students and adult patients. RESULTS: Three hundred and twenty-five patient questionnaires were collected (77% response), including 135 student encounters. Students did not affect appointment durations (19 min +/- 0.48 (standard error)) except at centre B (35 min +/- 1.1, P < 0.0001) where patient numbers were cut for teaching. Patient satisfaction, generally high, was not affected by students, appointment duration or gender of doctor or patient. It was slightly higher in the lower social classes (rs = 0.20, P = 0. 003) and older patients (rs = 0.17, P = 0.002). Student acceptability scores were not affected by student numbers (up to four), social class or time spent alone with students. They were higher if time was spent alone with the doctor (75.3% +/- 4.9) than not (63.0% +/- 1.8, P = 0.024). Thirty-six per cent of patients preferred to have a student present; only 9% preferred not. Student satisfaction was higher at centre B (73.7% +/- 2.3) where appointments were longer and students spent more time alone with patients than centre A (64.3% +/- 2.3, P = 0.0052). CONCLUSIONS: Clinic appointments are not necessarily longer in the presence of students. When students have the chance to see patients alone during longer consultations, student satisfaction is higher. Patient satisfaction, generally high, is not altered by the presence of students, but patients given time alone with their doctor are more accepting of students. These findings have resource implications for the planning of NHS clinics in teaching hospitals.

Education, Medical, Undergraduate↗
PubMed1999

Focus groups.

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England↗
PubMed1996

Local anaesthesia in flexible nasendoscopy. A comparison between cocaine and co-phenylcaine.

Flexible nasendoscopy is now an integral part of the diagnostic process in Otorhinolaryngology. Topical local anaesthesia is generally recommended and cocaine is usually the drug of choice in view of its concurrent vasoconstrictor action. However, it is expensive, a controlled drug and serious side effects have been reported. Co-phenylcaine forte is a new preparation which also has both local anaesthetic and vasoconstrictor properties. This study compares the efficacy of cocaine and Co-phenylcaine in flexible nasendoscopy and concludes that they provide similar local anaesthesia and vasoconstriction of the nasal mucosa. Co-phenylcaine forte can therefore be used as an alternative to cocaine in flexible nasendoscopy.

Adolescent↗
PubMed1996

Apoptosis and mitosis in oral and oropharyngeal epithelia: evidence for a topographical switch in premalignant lesions.

Apoptosis (programmed cell death) may play a part in carcinogenesis. The mucosa of the oral cavity, a common site for the development of dysplasia and squamous cell carcinoma, is ideal for the study of carcinogenesis in vivo. Earlier work suggested that apoptosis falls with the development of carcinoma, and that carcinogenesis is preceded by topographical changes in apoptosis. To explore these hypotheses, 72 paraffin sections were obtained: 15 normal (N), nine mild dysplasia (D), 15 severe dysplasia/carcinoma in situ (CIS), 30 squamous cell carcinoma (SCC: power analysis suggested 15 per group). Apoptotic (AI) and mitotic (MI) indices and AI/MI ratio were calculated (1000 cells/slide). These, with age, sex, alcohol and smoking habits, and anatomical subsite, were entered into a regression model with histological group as dependent. Vertical cell position (cp) was plotted, and resultant frequency curves were compared. MI significantly increased (mean N 0.39, 95% confidence interval 0-0.35; D 0.63, 0.23-0.98; SCC 0.86, 0.51-1.21, P < 0.0001) and AI/MI significantly decreased (D 0.54, 0.20-0.86; SCC 0.28, 0.05-0.61, P < 0.05) progressing from D, through CIS, to SCC. However, after inclusion of all variables, only MI remained significant (P < 0.0001). Peak incidence of mitosis shifted downwards in CIS relative to N and D, whilst peak apoptosis shifted upwards. Thus, programmed cell death remains static as mitosis increases in carcinogenesis of the oral cavity. However, there is an alteration in the topographical relationship of these events in CIS which may make homeostatic mechanisms involving apoptosis less efficient.

Adolescent↗
PubMed1992

Ingested foreign bodies: patient-guided localization is a useful clinical tool.

We prospectively studied the latest 60 patients who presented to the ENT Departments of St Mary's and St George's Hospitals with ingested foreign bodies. Localization of the foreign body by the patient was compared to the actual site of the foreign body at removal and graded accordingly. Localization was better the higher the object. When compared with objects above the cricopharyngeus muscle items impacted below this level were poorly localized (P < 0.0001) and lateralized (P < 0.0001). This suggests that for a patient who is able to lateralize a presumptive foreign body within the cervical region, then that object is likely to be above cricopharyngeus and on the side indicated. Further, it is likely to be visible on indirect laryngoscopy and amenable to removal in the casualty department. We hypothesize that the pharyngeal innervation by the vagus and glossopharyngeal nerves provides better sensation than in the oesophagus which is innervated less densely by the vagus and cervical sympathetic nerves.

Adolescent↗