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Biomedical subjects

H Burns

Publications and source records attributed to H Burns.

At least 19 recordsLinked to original sources
PubMed2006

Neglected keratosis obturans causing facial nerve palsy.

Keratosis obturans is characterized by the accumulation of desquamated keratinous material in the bony portion of the external auditory canal. Classically, it is reported to present with severe otalgia, conductive hearing loss and global widening of the external auditory canal. Extensive erosion of the bony meatus, with exposure of the facial nerve, has been previously reported, but no case of facial nerve palsy has as yet been published. We report the first published case, to our knowledge, of a unilateral facial nerve palsy secondary to neglected keratosis obturans.

Cerumen↗
PubMed2006

Delayed facial nerve palsy following tympano-mastoid surgery: incidence, aetiology and prognosis.

OBJECTIVE: To establish the frequency of occurrence of delayed facial nerve paralysis following tympano-mastoid surgery in our department and to determine the aetiological factors and long term prognosis. SETTING: Tertiary care academic centre. MATERIALS AND METHODS: A retrospective review of all patients who had undergone tympano-mastoid surgery in our department over the previous five years was carried out. A total of 219 patients were included in the study. Only two patients were identified as having delayed onset facial nerve palsy over this period of time. The patients' medical records were reviewed and the patients clinically assessed. RESULTS: The frequency of delayed onset facial nerve palsy following tympano-mastoid surgery in our series was 0.91 per cent. Facial weakness set in on day eight and day 14 in the two patients. Serological investigations in both patients revealed raised titres of immunoglobulin (Ig) M and IgG to varicella-zoster virus, confirming the presence of varicella-zoster infection. In our experience, the combined use of prednisone and acyclovir was an effective form of treatment for both patients, whose facial nerve function fully recovered within six months of onset. CONCLUSION: The incidence of delayed facial nerve palsy following tympano-mastoid surgery is low. It can occur up to two weeks after the surgery. Our two cases confirm viral reactivation to be an important aetiological factor in the development of delayed onset facial nerve palsy. The overall prognosis for delayed facial nerve palsy following tympano-mastoid surgery appears to be good.

Acyclovir↗
PubMed2001

Treatment of oral cancer: the need for defined protocols and specialist centres. variations in the treatment of oral cancer.

The authors of this study aimed to identify treatment philosophies for oral cancer within the west of Scotland and to investigate any survival differences associated with the various treatment options by means of a retrospective review of case notes and cancer registry data. All patients with squamous cancer of the tongue or floor of the mouth were identified from the West of Scotland Cancer Registry for the period 1984-1990. A total of 206 patients were available for study. Five different treatment protocols were identified: 5% of patients underwent biopsy only, 16% biopsy plus radiotherapy, 11% excisional biopsy, 25% radical surgery, and 42% radical surgery plus radiotherapy. Tumour staging by the TNM classification was an important factor that determined outcome. When adjusting for T stage and nodal involvement, there was a significant effect of treatment protocol on both the disease-free period (P < 0.001) and on survival (P < 0.001). The treatment options were used differently by individual clinicians and were related to stage of the disease. One hundred and forty-four (70%) of the patients were treated by a single combined head and neck unit based within the plastic surgery unit at Canniesburn Hospital. The remaining 62 were treated in 13 different units throughout the west of Scotland. For those not treated in the combined head and neck unit, the increased hazard for recurrence was 1.43 (95% confidence interval (CI) 1.01-2.02), and the increased hazard ratio for death was 1.48 (95% CI 1.06-2.06) when adjusting for tumour stage, and nodal involvement. Treatment philosophies for oral cancer have a significant effect on outcome. There is a need to develop clearly defined protocols based on staging and site of disease. We believe that treatment should be carried out within a multidisciplinary setting in a combined head and neck cancer unit.

Adult↗
PubMed1996

Three's a crowd.

Where do patients' rising expectations fit into the purchaser/provider relationship? John Spiers, Harry Burns and Michael Richards look at this question from a patient, purchase, and provider perspective.

Health Care Rationing↗
PubMed1996

Effects of L-canavanine, an inhibitor of inducible nitric oxide synthase, on endotoxin mediated shock in rats.

The effects of L-canavanine, an inhibitor of nitric oxide synthase, on endotoxin-induced shock was investigated in the pentobarbitone anesthetized rat. Endotoxin infusion (2.5 mg kg-1 h-1 over 6 h) produced progressive and marked hypotension and hypoglycemia. Electron microscopy showed marked changes in the kidney, comprising severe endothelial cell disruption and the accumulation of platelets in the blood vessels. In the lung, there was marked accumulation of polymorphonuclear leukocytes in small blood vessels and endothelial disruption. Treatment with L-canavanine (10 mg kg-1 by bolus injection each hour starting 70 min after endotoxin or saline infusion) significantly reduced endotoxin-induced hypotension, without any effect on the hypoglycemia. This treatment markedly reduced the endotoxin-induced electron microscopical changes in the kidneys and lungs. Although L-canavanine, like L-NAME, inhibited both cerebellar constitute and splenic inducible nitric oxide synthase in vitro, in contrast to L-NAME it did not modify either arterial blood pressure or carotid artery blood flow in control rats. The data are consistent with L-canavanine being a selective inhibitor of inducible nitric oxide synthase, at least in vivo, and suggest that inhibitors of this enzyme may be beneficial in endotoxin-induced shock.

Animals↗
PubMed1994

Thermal energy requirement for strand separation during transcription initiation: the effect of supercoiling and extended protein DNA contacts.

We have studied the role of extended protein DNA contacts and DNA topology on the ability of Escherichia coli RNA polymerase to form open complexes at several related promoters. The -35 region of several Escherichia coli promoters do not have homology with the consensus sequence, but still drive activator independent transcription initiation. This is due to the presence of a TG motif upstream from the -10 hexamer creating an 'extended -10' promoter. We have previously shown that two 'extended -10' promoters, galP1 and pBla, can form open complexes at lower temperatures than the galP1 derivative, galPcon6, which has a consensus -35 hexamer. Here we report further investigations into the mechanism of open complex formation by RNA polymerase, in particular the thermal energy requirement. A single base pair change in galPcon6 creating an 'extended -10' sequence, results in a 20 degrees C reduction in the temperature requirement for open complex formation. The DNA topology has also been shown to effect the thermal energy requirement for strand separation. Promoters carried on supercoiled plasmids form open complexes at lower temperatures than when present on linear DNA templates. We have also shown that in vivo, RNA polymerase can form open complexes at lower temperatures than those observed for linear templates in vitro, but requires slightly higher temperatures than supercoiled templates in vitro, however the promoter hierachy remains the same.

Base Composition↗
PubMed1994

Monostotic fibrous dysplasia of the temporal bone with associated lymphadenopathy.

Fibrous dysplasia of the temporal bone is a very unusual condition and its association with an abnormal lymph node has not been previously reported. Although it is benign condition causing conductive deafness, cholesteatoma may develop insidiously as illustrated by this case. We recommend regular long term follow up and surgical exploration if a changing clinical picture suggests the possibility of complications.

Child↗
PubMed1993

An audit of the E.N.T. casualty service at the Royal Victoria Eye and Ear Hospital.

The only specialised Accident and Emergency unit for ENT in Ireland is at The Royal Victoria Eye and Ear Hospital, Dublin. This provides a service for the entire Republic, operating on a 9 am to 5 pm, Monday to Friday, basis. The aim of the present study was to define the role of this specialised unit. A prospective study of the service over a one month period was conducted. During this time 779 patients were seen of which 350 (45%) were new patients and 429 (55%) were return patients. Fifty two per cent were self referred, 35% were referred by their General Practitioners, 8% by other hospitals and 5% from other sources. The most common diagnosis was otitis externa (21% of new patients and 63% of returns), followed by ear wax (15% of new patients), and epistaxis (9% of new patients). Five per cent of patients required removal of foreign bodies from their ear, nose or oesophagus, and 3% received treatment for trauma to these regions. Of note during this period six new cases of head and neck cancer were detected. From these figures it is the authors' opinion that many of the problems seen could have been dealt with by General Practitioners or as non-emergency referrals to the out-patient department. This indicates the need for further training for primary care physicians and expansion of the present outpatients services. The specialised casualty service should continue to exist to provide a genuine emergency service and valuable training in the speciality.

Accidents↗
PubMed1992

Catalase/peroxidase activity in dental pulp.

Extrinsic stains on vital teeth are bleached with 30% hydrogen peroxide (H2O2) or carbamide peroxide, H2O2 greatly inhibits the activity of several enzymes. Free H2O2 and carbamide peroxide readily enter the pulp through the coronal wall of the tooth. Nevertheless, adverse effects have been remarkably rare. This study was undertaken to determine whether dental pulp exhibits any catalase or peroxidase activity that might protect it from damage during vital bleaching procedures. Pulpal tissue from healthy human teeth was assayed for catalase and glutathione peroxidase activity. A phosphate buffer extract of the tissue served as the source of the enzymes. The rate of breakdown of H2O2 by the tissue extract was measured and the rate constant for catalase was determined. The catalase activity, defined as microM H2O2 broken down/min/mg wet tissue, was determined and found to be only 2 x 10(-2), which is very low. The fibrous pulpal tissue was found to exhibit virtually no glutathione peroxidase activity.

Catalase↗