The Perception of a Changing Shape

Under specified conditions a pair of simple shapes are matched by a subject when almost all supplementary textural and space cues of depth vision have been removed. Under such conditions it is found that shape constancy is no longer present. However, the effect of regular rotatory motion of the shape is sufficient to restore constancy in the continued absence of other cues. Degree of perceptual constancy appears to be correlated with rate of change of shape. It is suggested that an explanation of the phenomenon is to be sought along the lines of Michotte's concept of “object creation” rather than in terms of gradient variables.

Further Studies in the Perception of a Changing Shape

Koffka's hypothesis of “invariant relation” holding between tilt and perceived shape of an object is discussed from the standpoints both of logical tenability and of experimental findings.

After discussion of certain shortcomings in the method of investigation devised by Stavrianos, two experiments are suggested, the first, of a simple character, intended to follow out in practice the hypothetical conclusions of Koffka's argument, the second to test the hypothesis under conditions which attempt to ensure the preservation of the perceptual object throughout the arc of tilt. For this purpose subjects attempt to match two shapes, one of which is stationary whilst the other revolves at a constant speed. The comparison shapes cover the range of the possible arc of tilt.

The results of the first experiment, whilst appearing to contradict the requirements of the hypothesis, are by no means conclusive. The second experiment, though not absolutely conclusive, gives little support to Koffka. The main conclusion drawn is that there occur non-systematic variations in perceptual constancy throughout the arc of tilt. These are of a phasic character and are qualitatively different from results obtained by matching stationary shapes. There appears to be no simple function which would result in exhibiting a uniform constancy value for the entire arc of orientation.

Marathon of eponyms: 26 Zinsser-Engman-Cole syndrome (Dyskeratosis congenita)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Zinsser-Engman-Cole syndrome.

Marathon of eponyms: 25 Yersiniosis

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Yersiniosis.

Marathon of eponyms: 24 Xmas (Christmas) disease

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Christmas disease.

Marathon of eponyms: 23 Wegener granulomatosis

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology and oral, oral and maxillofacial radiology and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Wegener granulomatosis.

Marathon of eponyms: 22 Virchow node

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Virchow node.

Marathon of eponyms: 21 Urbach-Wiethe disease (Lipoid proteinosis)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Urbach-Wiethe disease.

Marathon of eponyms: 19 Sjögren syndrome

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Sjögren syndrome.

Marathon of eponyms: 18 Robin sequence

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Robin sequence.

Marathon of eponyms: 17 Quincke oedema (Angioedema)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Quincke's oedema.

Marathon of eponyms: 16 Paget disease of bone

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Paget disease of bone.

Marathon of eponyms: 15 Osler-Rendu-Weber disease (Hereditary haemorrhagic telangiectasia)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Osler-Rendu-Weber disease.

Marathon of eponyms: 12 Ludwig angina

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Ludwig angina.

Marathon of eponyms: 7 Gorlin-Goltz syndrome (Naevoid basal-cell carcinoma syndrome)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Gorlin-Goltz syndrome.

Marathon of eponyms: 8 Hodgkin disease or lymphoma

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Hodgkin disease.

Marathon of eponyms: 9 Imerslund-Grasbeck syndrome (Juvenile pernicious anaemia)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Imerslund-Grasbeck syndrome.

Marathon of eponyms: 6 Frey syndrome (Gustatory sweating)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Frey' syndrome.

Marathon of eponyms: 5 Ehlers-Danlos syndrome

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarizes data about Ehlers-Danlos syndrome.

Marathon of eponyms: 4 Down syndrome

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in Diseases of the head and neck is mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognized relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This paper summarizes data about Down syndrome.

Marathon of eponyms: 3 Crouzon syndrome

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Crouzon syndrome.

Marathon of eponyms: 2 Bell palsy (idiopathic facial palsy)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009: 15; 185-186). The use of eponyms in diseases of the head and neck is found mainly in specialties dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This document summarises data about Bell paralysis.

Marathon of Eponyms: 1 Albers-Schönberg disease (osteopetrosis)

The use of eponyms has long been contentious, but many remain in common use, as discussed elsewhere (Editorial: Oral Diseases. 2009 in press). The use of eponyms in diseases of the head and neck is mainly in specialities dealing with medically compromised individuals (paediatric dentistry, special care dentistry, oral and maxillofacial medicine, oral and maxillofacial pathology, oral and maxillofacial radiology and oral and maxillofacial surgery) and particularly by hospital-centred practitioners. This series has selected some of the more recognised relevant eponymous conditions and presents them alphabetically. The information is based largely on data available from MEDLINE and a number of internet websites as noted below: the authors would welcome any corrections. This paper summarises data about Albers-Schönberg disease.

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Cost benefit with early operative fixation of unstable ankle fractures

INTRODUCTION

Ankle fractures are common and many require surgical intervention. It has been well documented that a delay in fracture fixation results in increased length of hospital stay and increased complication rate. Initial delay can also allow swelling or blistering to develop which may necessitate a further delay in operative fixation for up to 1 week. The aim of the current study was to review the length of hospital in-patient stay for operative ankle fractures over the previous 12-month period at our hospital and compare this to the length of hospital stay following the introduction of a fast-track system for the fixation of these fractures (all fractures fixed within 48 h).

PATIENTS AND METHODS

A retrospective review of all ankle fractures managed by open reduction and internal fixation over a 12-month period was undertaken. A protocol was then agreed to openly reduce and fix these fractures at the earliest possible opportunity over the next 6-month period. We then collected the data on all ankle fractures that needed open reduction and internal fixation over this 6-month period. The pre-protocol and post-protocol groups were then compared for total hospital length of stay and complication rate.

RESULTS

In the 12-month retrospective review, there were 83 ankle fractures that required surgical intervention. Sixty-two of these had surgery within 48 h (mean length of stay, 5.4 days), and 21 had surgery after 48 h (mean length of stay, 9.5 days). There were 39 ankle fractures in the post-protocol group who all had surgery within 48 h (mean length of stay, 5 days). There was no increase in complication rate after implementation of the fast-track system.

CONCLUSIONS

This study shows that early operative intervention for ankle fractures reduces the length of hospital stay. Intensive physiotherapy and co-ordinated discharge planning are also essential ingredients for early discharge. Early operative fixation for unstable ankle fractures has substantial cost-saving implications with no increase in complication rate.

Poland's Syndrome And Military Personnel

We describe three cases of undiagnosed Poland's syndrome in Army personnel and discuss their fitness according to the PULHHEEMS system. This syndrome has variable clinical features that include unilateral chest wall and upper limb abnormalities. The syndrome is not hereditary and is of unknown origin. If the syndrome was diagnosed prior to enlistment the potential recruit would normally be graded P8, and unfit to enlist. However, these individuals had managed to pass routine medical examination as well as successfully complete basic training. The suitability of continuation in the army of personnel with Poland's syndrome is discussed.

Profiling clonality and progression in multiple premalignant and malignant oral lesions identifies a subgroup of cases with a distinct presentation of squamous cell carcinoma

A cohort of head and neck cancer patients, without exposure to tobacco and alcohol, presented with multiple preneoplastic and neoplastic lesions, the natural history of which may span several decades. Examination of these cases provides an opportunity to study the relationship between genetic, morphological, and clonal progression in these fields and establish whether they represent a unique presentation of squamous cell carcinoma. The presence of a common novel microsatellite allele, a common breakpoint or concordant allelic imbalance at multiple loci, reveals that a high proportion of these serial lesions arise due to spread of a precursor. The tumors arising in these patients were typically nonaggressive, although metastases developed at a late stage, supporting the notion that the genotype results in a phenotype with a propensity for lateral spread, rather than invasion. Different genetic aberrations were detected in morphologically similar phenotypes such that no consistent early or late events were associated with development of premalignant lesions. Combining information about the clinicopathological features and histological examination of the margins with that derived from clonality analysis reveals that a subgroup of patients, without exposure to the traditional risk factors associated with this disease, developed multiple clonally related oral lesions and represents a unique presentation of head and neck squamous cell carcinoma. We suggest the term clonal cancerization to describe multiple premalignant and malignant lesions when there is conclusive evidence that they arise due to lateral spread from a common precursor.

The pattern of expression of the 5T4 oncofoetal antigen on normal, dysplastic and malignant oral mucosa

The human 5T4 oncofoetal antigen is expressed by all types of trophoblast in pregnancy but is not detected on most adult tissues, although low levels are found on some epithelia. However, this antigen is strongly expressed by many cancers and tumour-associated labelling correlates with metastatic spread and poor clinical outcome for patients with gastric and colon cancer. Over-expression of the gene influences cell adhesion, shape and motility, which may be related to changes in the cellular localisation of the 5T4 oncofoetal antigen as malignancy develops. To establish whether the 5T4 oncofoetal antigen can serve as a tumour-specific marker for oral cancer and precancer, we have evaluated the pattern of expression on biopsies of normal, inflamed and dysplastic oral mucosa using immunohistochemistry. Oral mucosa, taken from different sites in the mouth, expressed the 5T4 oncofoetal antigen with varying intensity and pattern. The majority of the immunoreactivity was detected in the basal and suprabasal layers, with expression extending into the spinous cells at fully keratinised sites and when inflammation was present. This antigen was also detected in the underlying connective tissue. Oral squamous cell carcinoma showed a variety of patterns and intensity of staining corresponding to those found for normal mucosa. However, 21 of 41 cases showed no stromal labelling, a finding also observed for dysplastic lesions. The alterations in the pattern and intensity of 5T4 oncofoetal antigen expression were not related to clinicopathological features of the tumours examined. These data show that the 5T4 oncofoetal antigen is expressed on normal oral mucosa, such that this target cannot be used for detection of neoplastic or preneoplastic cells, although altered expression may contribute to the pathogenesis of these lesions.

Location of candidate tumour suppressor gene loci at chromosomes 3p, 8p and 9p for oral squamous cell carcinomas

To help define the location of tumour suppressor genes implicated in the pathogenesis of oral squamous cell carcinoma (SCC), we have used microsatellite assay and restriction fragment length polymorphism (RFLP) analysis to screen 48 primary SCC for allelic imbalance (AI) with 32 polymorphic markers at chromosome 3p, and prepared a detailed deletion map. The finding of a high frequency of AI at specific regions, together with the presence of multiple small interstitial deletions involving these loci, identifies 5 areas at this chromosome arm that may harbour tumour suppressor genes. No sequence aberrations affecting the von Hippel Lindau (VHL) and fragile histidine triad (FHIT) genes, which reside within the candidate tumour suppressor gene areas at this chromosome arm, were identified. A more limited analysis of polymorphic sequences at 8p and 9p supports the existence of at least 2 areas that harbour tumour suppressor genes at 8p and evidence that additional targets for deletion reside centromeric and telomeric to the p16 gene at 9p21.

Patient-specific mutation databases for oral cancer

Development of databases, summarising the genetic events associated with oral squamous cell carcinoma (SCC), should increase our understanding of the molecular basis of these lesions. Additionally, databases will help establish whether different cancer subtypes show different growth characteristics, because the multistage carcinogenic process is different in the various tumour subtypes. This new knowledge may also provide new prognostic information, as these aberrations represent fundamental biological characteristics of each tumour. To assess the value of incorporating the results from loss of heterozygosity (LOH) analysis into patient-specific mutation databases, we have carried out microsatellite analysis with 52 polymorphic markers at 13 key chromosomal regions implicated in the pathogenesis of head and neck cancers. Altered expression of the Rb, p53 and DCC tumour suppressor genes has also been studied by immunohistology. Our results shed light on the different pathways that lead to cancer and reveal that a variety of different patterns of allelic imbalance (AI) were detected at all TNM stages, reflecting the different clinical behaviour that tumours classified as being of the same TNM stage may exhibit. Summarising the level of genetic damage as a fractional allelic loss (FAL) score and the presence of AI at 3p22-26, 3p14.3-12.1 and 9p21 was found to be a better predictor of outcome than the TNM system. This finding suggests that molecular data can be incorporated into conventional staging systems to provide more accurate prognostic information for this group of patients.

The prognostic significance of allelic imbalance at key chromosomal loci in oral cancer

Forty-eight primary oral squamous cell carcinomas (SCC) were screened for allelic imbalance (AI) at 3p24-26, 3p21, 3p13, 8p21-23, 9p21, 9q22 and within the Rb, p53 and DCC tumour suppressor genes. AI was detected at all TNM stages with stage 4 tumours showing significantly more aberrations than stage 1-3. A factional allelic loss (FAL) score was calculated for all tumours and a high score was associated with development of local recurrence (P = 0.033) and reduced survival (P = 0.0006). AI at one or more loci within the 3p24-26, 3p21, 3p13 and 9p21 regions or within the THRB and DCC genes was associated with reduced survival. The hazard ratios for survival analysis revealed that patients with AI at 3p24-26, 3p13 and 9p21 have an approximately 25 times increase in their mortality rate relative to a patient retaining heterozygosity at these loci. AI at specific pairs of loci, D3S686 and D9S171 and involving at least two of D3S1296, DCC and D9S43, was a better predictor of prognosis than the FAL score or TNM stage. These data suggest that it will be possible to develop a molecular staging system which will be a better predict of outcome than conventional clinicopathological features as the molecular events represent fundamental biological characteristics of each tumour.

Allelic imbalance at chromosomal loci implicated in the pathogenesis of oral precancer, cumulative loss and its relationship with progression to cancer

A microsatellite assay was used to screen 31 potentially malignant oral lesions presenting as leukoplakia and erythroplakia, with histological evidence of dysplasia, for genetic abnormalities at loci which frequently show allelic imbalance when oral squamous cell carcinomas (SCC) are examined. The microsatellite and restriction fragment length polymorphism (RFLP) markers selected were at 3p21, 8p21-23, 9p21 and included sequences within the Rb (13q14.2), p53 (17p13.1) and DCC (18q21.1) tumour suppressor genes. 8 patients subsequently developed an invasive tumour at the same site, or within 2 cm of the premalignant lesion. A further 8 patients developed SCC at a distant site. Seventy-seven per cent (24/31) of these potentially malignant lesions showed allelic imbalance (AI) and 55% (17/31) of cases showed microsatellite instability (msi). The probability of developing SCC was much greater for patients with lesions showing AI at two or more relevant loci (P = 0.008 by the logrank test) than the group with AI at fewer loci. The estimated probability of development of SCC in this group by 5 years was 73% (95% Cl: 50-92%). This suggests that determining the number of genetic abnormalities in a potentially malignant lesion can help identify patients with true precancers who should be followed closely to ensure that they receive chemoprevention and appropriate advice to limit risk factors, and to allow the early detection of invasive lesions.

Field cancerisation of the oral cavity: comparison of the spectrum of molecular alterations in cases presenting with both dysplastic and malignant lesions

Dysplastic lesions and invasive oral squamous cell carcinoma (SCC) from patients with field change were screened by restriction fragment length polymorphism (RFLP) and microsatellite assay. All tumours contained more genetic changes than the matched dysplasia which are likely to represent progression. Four of the 15 dysplastic lesions harboured the same abnormalities detected in the tumour and some paired lesions showed identical novel microsatellite alleles. The finding of identical 'genetic fingerprints' in dysplastic lesions and invasive carcinoma from the same patient provides strong evidence that these dysplasias are precursor lesions and that multiple lesions have probably arisen due to transfer of the progeny of an altered cell. Eight of the 15 dysplastic lesions showed alterations which were not present in the matched cancer, showing that evolution of subclones, or fusion of multiple clones also occurs. A further case showed loss of different alleles in the paired samples. These findings highlight the complexity of the genetic abnormalities present in the mucosa of patients with field change and suggests that the origin of these altered foci may be diverse.

Molecular identification of an IgE-dependent histamine-releasing factor

An immunoglobulin E (IgE)-dependent histamine-releasing factor (HRF) produced by lymphocytes of atopic children and present in biological fluids of allergic patients has been identified and purified. Amino-terminal sequencing revealed extensive homology to a mouse protein, p21, and its human homolog, p23. Both recombinant proteins caused histamine release from the human basophils of a subpopulation of donors, and this release was dependent on IgE. Polyclonal antibodies recognized and removed the biological activity of recombinant and native HRF. HRF identifies a heterogeneity of IgE and is believed to play a prominent role in chronic allergic disease processes.

Prehospital actions by health-care providers and physicians

Extensive worldwide experience and literature exist on the benefits of early intervention in patients with an acute myocardial infarction. To make these benefits available to as much of the population as possible a number of goals have to be accomplished. Patients and bystanders must be taught to recognize the significance of symptoms and call immediately for assistance. Local emergency medical service has to dispatch appropriate personnel and equipment to the scene expeditiously. Transport without unacceptable delays must occur to appropriate facilities along with rapid initiation of treatment. A program to achieve these goals would be expected to substantially reduce morbidity and mortality. Attention is directed to prehospital actions by health-care providers including dispatch of personnel and equipment to the scene, stabilization and treatment in the field, and triage and transport of the patient to the most appropriate medical facility.

Autologous keratinocyte grafting: a new technique for intra-oral reconstruction

Oral keratinocytes have been grown in sheets in the laboratory from small oral biopsies from four patients undergoing reconstructive oral surgery. These sheets have been successfully applied to mucosal surfaces and good clinical results obtained, with accelerated healing of mucosal defects. These results indicate that keratinocyte grafts can be used in mucosal sites, and may have applications as an alternative to skin grafts in the mouth.