Laser Doppler flux-metry as an experimental tool in laryngology

Angiogenesis is a cascade-like mechanism, essential for the progression of solid tumours. Quantifying microvessel density is considered the gold standard for measuring baseline angiogenesis and indeed "the response to intervention". Applying immunohistochemical techniques to biopsies conventionally does this; however, it would be very helpful to have a less invasive, reliable method of quantifying blood flux, and hence angiogenesis. The aim of the study was to validate the use of a laser Doppler flux meter as an experimental tool in laryngology. The principle and technique of laser Doppler flux-metry is described. A validation study designed to estimate the reproducibility and ability to measure change was performed in the human larynx and in an animal model. Statistical advice was sought and analysis was performed using SPSS software. Our experiments show good reproducibility of laser Doppler measurements in the human and animal model (correlation coefficient 0.956 and 0.947, respectively, P=0.01). We have also shown that the laser Doppler flux meter is capable of detecting change when it is expected ( P<0.01). Utilising a standardised technique, laser Doppler flux-metry appears to be a reliable and reproducible method of estimating blood flux in the larynx.

Laser Doppler flux-metry in laryngeal squamous cell carcinoma

Tumour angiogenesis has recently attracted a great deal of attention as a critical part of oncogenesis and a necessary prerequisite for a malignant phenotype. Novel antiangiogenic therapy for solid tumours including laryngeal cancer is entering clinical trials. Quantifying microvessel density is considered the gold standard for measuring baseline angiogenesis and indeed 'the response to intervention'. We hypothesize that laser Doppler flux-metry could provide a non-invasive reliable method of quantifying blood flux within tumours. The aims were to determine whether a laser Doppler flux meter could be used as a reliable and reproducible method of estimating blood flux in the human larynx and to establish baseline Doppler flux recordings for the human larynx. The method used was a validation study in patients with laryngeal squamous cell cancer and normal controls. Statistical analysis was performed using SPSS software. We have demonstrated good reproducibility of laser Doppler measurements in human laryngeal mucosa (correlation coefficient 0.956 @P = 0.01). We have also derived arbitrary means of laser Doppler flux-metry in normal laryngeal mucosa and in squamous cell carcinoma of the larynx. Comparisons between normal and tumour laser Doppler flux-metry (LDF) readings showed no significant difference. We suggest that Laser Doppler flux-metry is a potentially useful tool with which to study blood flow in the larynx and propose arbitrary LDF levels for the normal and diseased human larynx.

Model for experimental revascularized laryngeal allotransplantation

BACKGROUND

Although a human laryngeal transplant has been undertaken successfully, important questions remain that require a suitable animal model.

METHODS

A pig model for allotransplantation has been developed. Organ perfusion was studied in nine animals before four transplants were performed in congenic (unrecovered) animals and eight in unmatched (recovered) animals. Larynges were regularly examined endoscopically until death at 14 days. Immunosuppression included the use of tacrolimus. Revascularization was achieved by anastomosing the donor right cervical vascular tree to the recipient common carotid. In recovered animals, four allografts were placed orthotopically and four heterotopically.

RESULTS

The pig larynx was perfused adequately via the right cervical vascular tree and congenic grafts were well tolerated. Of eight allografts, seven were well tolerated and remained healthy for the duration of the study (14 days). One allograft became infected between days 4 and 7 after operation. Median operating time was 6 h, with a median cold ischaemia time of 3 h.

CONCLUSION

Revascularized allotransplants of the larynx can be undertaken reliably in pigs and this provides a preclinical model for studies of laryngeal transplantation.

Critical path analysis in head and neck cancer: a management technique for surgical oncology

This paper describes a study of critical path analysis (CPA) as applied to the process of care for patients with head and neck cancer. CPA is a management technique, which has been developed in both the Armed Forces and a wide range of industries. It identifies the parts of a process where improvements are most likely to make an impact on the overall time for that process. There is evidence that reducing the overall times for an oncology care process has a major impact on outcome for patients. This paper describes an appraisal of a formal application of CPA in the setting of oncology. The technique was applied to a single head and neck unit. The results were compared with published standards for times in the care process and with the comparable times for the whole of the South and West of England. The critical path (the combination of processes that limits the total time taken for the whole process) at this unit ran through the combined oncology clinic, leading to a decision to increase the frequency of these clinics, which lead to a reduction in overall process time for patients. A randomised controlled trial in five centres in the South and West region will follow which includes patient quality of life outcomes and collaborative practice to assess the impact of CPA on the patient care process.

Interleukins 7 and 12 are expressed in head and neck squamous cancer

Interleukin 7 (IL-7) and IL-12 have major roles in cell-mediated tumour immunity. In head and neck squamous cell cancer, depressed cell-mediated immunity is well documented and may account for the poor prognosis. This is the first study to assess intratumour expression of IL-7 and IL-12 in head and neck squamous cell cancer (HNSCC). Immunohistochemistry was used to identify IL-7 and IL-12 expression in snap-frozen tumour specimens from 25 patients with HNSCC and the results of immunohistochemical staining were semiquantitatively graded. Both IL-7 and IL-12 were expressed in all tumour samples and expression was not related to tumour stage or site. A trend towards better survival was associated with high expression of IL-7 and IL-12, this being more pronounced with IL 7. The universal expression suggests that the depressed cell-mediated immunity in HNSCC is not caused by reduced production of IL-7 and IL-12. Further studies with larger cohorts, especially of IL-7, are certainly warranted.

Assessment of hearing in persons with learning disabilities: the Phoenix NHS Trust, January 1997 to September 1998

People with learning disabilities are at increased risk of impaired hearing. The aims of this study were to assess the prevalence of hearing impairment and ear disease in people attending the specialist Otolaryngology/Hearing Therapy clinic at the Phoenix NHS Trust, Bristol. The present and future process of such a service was explored. Data were obtained from the referral form and notes made by the consultant otolaryngologist. In 20 months, there were 226 consultations, 188 of which were new referrals. The majority of patients had verbal communication to some extent. Suspected infection/inflammation and unobtainable/abnormal tympanograms, each accounted for 43 per cent of reasons for referral. Twenty per cent of patients were normal otologically. Eighteen per cent were provided with hearing aids and nine per cent required surgery. Ten patients underwent brainstem evoked response testing, half of whom had aidable hearing. Our results are comparable to published data of similar units. It is recommended that combined otolaryngology/specialist hearing therapy services are continued and further developed.

Reduced production of interleukin 12 by interferon gamma primed alveolar macrophages from atopic asthmatic subjects

BACKGROUND

Asthma is characterised pathologically by an inflammatory pulmonary infiltrate rich in T helper (Th) 2 cells and eosinophils. Interleukin (IL)-12 is a heterodimeric cytokine critical for driving the development of uncommitted Th cells to express a Th 1 phenotype. Reduced pulmonary production of IL-12 may therefore play a role in the pathogenesis of asthma by contributing to the pulmonary cytokine imbalance seen in asthma.

METHODS

IL-12 p70 protein levels in bronchoalveolar lavage fluid and p70 protein levels and IL-12 messenger RNA in alveolar macrophage cultures from normal and atopic asthmatic subjects were measured.

RESULTS

There was a significant difference between the mean IL-12 p70 protein level in the bronchoalveolar lavage fluid from asthmatic subjects (37.5 pg/ml) and from normal subjects (131 pg/ml, p = 0.04). Alveolar macrophages from asthmatic subjects produced significantly less IL-12 protein (30 pg/ml) and messenger RNA than those from normal subjects (69.5 pg/ml, p<0.005). These differences were not caused by inhibition of IL-12 production by IL-10 nor to generalised hyporesponsiveness of asthmatic alveolar macrophages from subjects to the effects of interferon (IFN)-gamma.

CONCLUSIONS

Pulmonary IL-12 production is lower in asthmatic subjects. This reduction is not the result of generalised hyporesponsiveness to IFN-gamma. Reduced IL-12 levels may contribute to the development of asthmatic pulmonary inflammation through dysregulation of Th cell development.

Recurrence and malignant degeneration of 89 cases of inverted papilloma diagnosed in a non-tertiary referral population between 1975 and 1995: clinical predictors and p53 studies

Eighty-nine patients with sinonasal inverted papilloma presenting between 1975 and 1995 were reviewed with the aims of studying predictors of tumour behaviour and correlating outcome with p53 expression. Correlation of clinical, radiological features and p53 status was made using chi2 and multiple logistic regression analysis with recurrence and malignant degeneration as the main outcome measures. Two patients had synchronous malignancy but no malignant degeneration was seen. There was no significant difference in recurrence between minor intranasal procedures and more extensive surgery for the first event. Younger patients were more likely to recur. (P = 0.0493, odds ratio 0.43). Those who smoked showed a trend towards multiple recurrence. p53 was expressed in 41% but did not predict recurrence. Morbidity was related to the extent of surgery. Inverted papilloma presenting to a non-tertiary centre is more benign than previously reported. Initial management by less extensive endoscopic surgery may reduce morbidity.

Performance and standards for the process of head and neck cancer care: South and West audit of head and neck cancer 1996-1997 (SWAHN I). South and West Regional Cancer Organisation Tumour Panel for Head and Neck Cancer

Evidence suggests wide variation in cancer care between different hospitals in the UK. To establish bench-marking data, we designed a prospective, 1 year regional study comparing key performance measures with established standards for the 28 hospital Trusts in the South and West of England involved in head and neck cancer care. 566 sequential patients with a newly-diagnosed head and neck cancer were included. Numbers referred and treated per hospital Trust were 1-58 and 1-65 respectively. 59% of patients received a pretreatment chest X-ray (standard 95%). 45% of patients were seen in a multidisciplinary clinic pretreatment (standard 95%), and this was proportional to the frequency of clinics held (P<0.0001). Median number of cases treated per surgeon was 4 (1-26), and by radiotherapist was 10 (1-51). Times between parts of the process of oral cancer care were closer to the standards than those for laryngeal cancer. Two patients were entered into a clinical trial. One had a quality-of-life score. Thus, in 1996-1997, in the South and West of England, there were major discrepancies between actual performance and established standards in many fundamental aspects of head and neck cancer care. Re-audit is essential to determine if the implementation of the Calman-Hine report has resulted in improvements.

A preclinical model for laryngeal transplantation: anatomy and mucosal immunology of the porcine larynx

BACKGROUND

A major step in translating work on laryngeal transplantation into clinical practice is the establishment of a preclinical model. We have investigated the anatomy and mucosal immunology of the porcine larynx in eight Minnesota Minipigs (12-37 weeks).

METHODS

Neck dissections were carried out and the vascular tree was mapped. Snap-frozen biopsies from epiglottis, supraglottis, glottis, and subglottis were prepared for conventional histology, immunohistochemistry (CD45), and single and two-color immunofluorescence (CD3, MHC-II, CD45).

RESULTS

The anatomy of the laryngeal skeleton was broadly similar to that of the human larynx. The blood supply is predominantly via the caudal thyroid vessels, with assistance from the cranial laryngeal artery. The porcine larynx is clearly highly immunologically active. Structured collections of leukocytes were found in the mucosal epithelium, around tubuloacinar glands, and occasionally in the submucosa. MHC-II and CD 3 cells were predominantly found within the epithelium. The highest densities of all cell types were observed in the epiglottis, tailing off caudally. The lowest densities were seen in the vocal cords.

CONCLUSIONS

The porcine larynx is both anatomically and immunologically similar to the human larynx and contains a high level of immunological organization. It presents an ideal preclinical model for laryngeal transplantation.

Do corticosteroids induce apoptosis in nasal polyp inflammatory cells? In vivo and in vitro studies

OBJECTIVE/HYPOTHESIS

Corticosteroids are an effective treatment for nasal polyposis. The exact mechanism of action is not certain. Recent research demonstrates that apoptosis (programmed cell death) in inflammatory cells is an important factor in the resolution of inflammation, and apoptosis is induced in eosinophils in cell culture with steroids. We hypothesized that inflammatory cell apoptosis is a key feature of regression of nasal polyps on exposure to steroids and examined this hypothesis in vivo and in vitro.

METHODS

A double-blind, placebo-controlled pilot study of fluticasone propionate aqueous nasal spray (FPANS) in nasal polyposis in humans in vivo was undertaken, and the effect of treatment on indices of cell death and proliferation measured. In addition, explants of nasal polyp tissue were maintained in vitro in short-term tissue culture with dexamethasone at increasing doses (0.1-50 micromol) over varying time intervals and then analyzed for similar indices of proliferation and cell death.

RESULTS

Apart from a marginal increase in apoptotic:mitotic ratio in epithelium, little difference between the effect of FPANS and placebo was demonstrated in vivo. However, in vitro, apoptotic index was significantly increased in the stromal layers in relation to time of incubation (P = .0169), and a significant dose-response relationship was demonstrated at 24 hours between stromal cell apoptosis and dexamethasone concentration (P = .001). Eosinophil apoptosis was confirmed by in situ end labeling and transmission electron microscopy. No steroid or time effect on epithelial cells was demonstrated in vitro.

CONCLUSION

Corticosteroids induce apoptosis in inflammatory cells in human nasal polyps in vitro. This is not reflected by a similar response to FPANS at 14 days in vivo, but may still play a part in regression of polyps with other forms of administration or at other time points.

A comparison of the anti-histone and Apop-Tag technique for demonstrating apoptosis with option for silver enhancement

A novel immunocytochemical method is presented for the qualitative detection of DNA fragmentation in apoptosis. Anti-histone antibody is employed to localize exposed nucleosomal histones (H1, H2a, H2b, H3 and H4) rather than tagging the cut ends of fragmenting DNA as in conventional technique. The method was tested on squamous cell carcinoma of the larynx routinely fixed in formaldehyde and embedded in paraffin wax and compared with results obtained employing Apop-Tag kit (Oncor).

Laryngectomees' views on laryngeal transplantation

Loss of a functional larynx has marked implications for quality of life that remain after both laryngectomy and its alternatives. One solution is laryngeal transplantation. We hypothesised that laryngeal transplantation would be unacceptable to a population of laryngectomees, and that such a lack of acceptability would not be affected by age, sex or time elapsed since operation. In addition, we sought the views of laryngectomees on priorities for research. A questionnaire was developed and mailed to 1000 members of laryngectomee clubs. A total of 372 of 404 responses were suitable for analysis. Seventy-five percent of the respondents said they would accept a transplant under ideal conditions; the number dropped to 58.9% when a stoma was to be retained. Fifty percent would accept a graft even if it did not result in a normal voice. A positive response was more likely in younger respondents (P < 0.001 all questions; linear regression). Some 47.3% of respondents thought research money could be better spent on other projects, and this response was commoner in older respondents (P = 0.0001). Highest priorities for research into laryngeal cancer were development of new treatments (63.2%), prevention (60.2%) and optimisation of quality of life (57%). In short, there appears to be a surprisingly high level of support for laryngeal transplantation amongst those who have had a laryngectomy.

Consensus standards for the process of cancer care: a modified expert panel method applied to head and neck cancer. South and West Expert Tumour Panel for Head and Neck Cancer

There are many pressures to improve the standard of care delivered to cancer patients, including the reforms subsequent to the Calman-Hine report. The establishment of standards is a prerequisite for audit, benchmarking and certification of cancer centres and units. Randomized trials of head and neck cancer are uncommon, and other forms of evidence often conflicting. In the south and west of England, a multidisciplinary expert panel consensus method has been applied to the development of standards. A panel representative of specialties involved in the process of care at all three levels, plus social medicine and lay members, was constructed. A model for the process of care was developed consisting of activity areas. For each activity, a near exhaustive list of tasks and standards was established. A three-iteration method with statistical group response was then used to refine the standards. The same method was also applied to the production of a minimum data set for registration, recording and audit. The resulting standards will be regularly reviewed. We have developed a model of the care process, and an expert panel methodology that is applicable to a wide range of problems in clinical oncology.

Morphometry of paranasal sinus anatomy in chronic rhinosinusitis: a pilot study

OBJECTIVES

To test the null hypothesis that there is no relationship between anatomical variations around the ostiomeatal complex and a predisposition to chronic rhinosinusitis and to define such variations with increased precision.

DESIGN

Case-control study of anatomical variations in diseased and normal sinuses. Eight homologous landmarks defining the ostiomeatal complex were located on coronal computed tomographic scans, and their x and y coordinates were digitized using image analysis.

SUBJECTS

Ten patients with unilateral sinus disease and 10 subjects without sinus disease (scanned for facial pain) who were selected retrospectively by case-note analysis.

RESULTS

Logistic regression showed that the only significant spatial change predictive of a person with rhinosinusitis was the vertical position of the middle turbinate (P=.04), although this was not confirmed by Wilcoxon testing (P>.10). When examined by sinus, however, the horizontal position of the uncinate process was more laterally placed in persons with rhinosinusitis (P=.01), confirmed on Wilcoxon testing (P=.04), but there was no significant difference when compared with sinuses in persons without rhinosinusitis.

CONCLUSIONS

Our findings suggest that there are no anatomical differences within the ostiomeatal complex between patients with and without rhinosinusitis. Patients with rhinosinusitis, however, are more likely to develop it in the side with a more laterally positioned uncinate process. Further studies, with more patients and more advanced techniques, including thin-plate spline analysis, are indicated.

Head and neck cancer in the South West of England: influence of socio-economic status on incidence and second primary tumours

This study examined possible links between the incidence of head and neck squamous cell carcinoma (HNSCC) and social deprivation. Data on all HNSCC registered between 1985 and 1991 in the South West of England were collected. Excluding tumours of the lip and skin there were 1570 cases, 72% in males. Of these, 1467 were identified as first primary tumours. Corrected chi-squared tests, accepting significance at the 5% level, were used to examine the association of socio-economic status (Carstairs index) with incidence at different sites. Overall, the incidence of HNSCC was higher in the socially deprived group. In males, the most deprived group had a significantly higher incidence of oral carcinoma than all other groups (P<0.05), whereas the incidence of laryngeal carcinoma showed a gradual rise with increasing deprivation. In females, where numbers were relatively low, the trend remained, but was less clear. In total, seventy-two (4.9%) cases went on to develop a second primary, of which 35% were in the lung and 13% in the bladder. Socio-economic status did not affect the development of a second primary tumour. The association of HNSCC with carcinoma of the bladder is a new finding.

Apoptosis, mitosis, PCNA and bcl-2 in normal, leukoplakic and malignant epithelia of the human oral cavity: prospective, in vivo study

Disordered balance between proliferation and apoptosis may contribute to carcinogenesis. Thirty-two oral biopsies were collected prospectively: 10 normal (N), 10 leukoplakia (dysplasia, D = 5; hyperplasia, H = 5) and 12 squamous cell carcinoma (C: 11). Distant normal tissue was also collected (HN, DN, CN). Based on counts of 1000 cells/slide, mitotic (MI), apoptotic (AI) and proliferating cell nuclear antigen (PCNA: PI) indices were calculated and bcl-2 expression recorded. AI correlated with MI (P < 0.001), but not PI or bcl-2 expression. PCNA was higher in H and HN than other groups (P < 0.0001). bcl-2 was reduced in C and CN (P < 0.001). Peak mitosis shifted basally in dysplasia, whilst peak apoptosis remained unaltered. These data confirm topographical alterations in proliferation relative to apoptosis in dysplasia of the oral cavity. Reduced bcl-2 in carcinoma and related 'normal' epithelium was unexpected, and may contribute to the high incidence of metachronous carcinomas in these patients.