Showing papers by "University of Nottingham published in 1991"

Pathological prognostic factors in breast cancer. I. The value of histological grade in breast cancer: experience from a large study with long-term follow-up.

Abstract: Morphological assessment of the degree of differentiation has been shown in numerous studies to provide useful prognostic information in breast cancer, but until recently histological grading has not been accepted as a routine procedure, mainly because of perceived problems with reproducibility and consistency. In the Nottingham/Tenovus Primary Breast Cancer Study the most commonly used method, described by Bloom & Richardson, has been modified in order to make the criteria more objective. The revised technique involves semiquantitative evaluation of three morphological features--the percentage of tubule formation, the degree of nuclear pleomorphism and an accurate mitotic count using a defined field area. A numerical scoring system is used and the overall grade is derived from a summation of individual scores for the three variables: three grades of differentiation are used. Since 1973, over 2200 patients with primary operable breast cancer have been entered into a study of multiple prognostic factors. Histological grade, assessed in 1831 patients, shows a very strong correlation with prognosis; patients with grade I tumours have a significantly better survival than those with grade II and III tumours (P less than 0.0001). These results demonstrate that this method for histological grading provides important prognostic information and, if the grading protocol is followed consistently, reproducible results can be obtained. Histological grade forms part of the multifactorial Nottingham prognostic index, together with tumour size and lymph node stage, which is used to stratify individual patients for appropriate therapy.

Analysing Service Quality in the Hospitality Industry Using the SERVQUAL Model

Abstract: This study reports an application in the hospitality industry of the SERVQUAL model developed by Parasuraman, Zeithaml and Berry. Although originally developed for application within the financial services sector, the model is designed to measure those components of service that generate satisfaction within five dimensions. This study identified the existence of gaps between clients' and management perceptions of attributes of the hotel, and between client expectation and perception of the services offered. It is argued that the existence of these gaps is a source of dissatisfaction with services provided. Factor analysis identified five dimensions explaining 78 per cent of variance, but these differed from the SERVQUA L model.

The structure of employee attitudes to safety: A European example

Abstract: This paper concerns organizational safety culture and the structure or architecture of employee attitudes to safety as part of that culture. It begins by reviewing the somewhat scant literature relevant to this area, and then reports a study, conducted in a European company, which collected and factor analysed data on employee attitudes to safety. The framework provided for the study was that offered by Purdham (1984), and the results suggested that employees' attitudes to safety, within this company (across occupation/occupational level and country), could be mapped By five orthogonal factors: personal scepticism, individual responsibility, the safeness of the work environment, the effectiveness of arrangements for safety, and personal immunity. The theoretical and practical implications of these findings are discussed, and attention is drawn to their subsequent use in an intervention to enhance safety culture within the organization by attacking supervisors' attitudes to safety.

Clinicopathological staging for colorectal cancer: an International Documentation System (IDS) and an International Comprehensive Anatomical Terminology (ICAT).

Abstract: The purpose of tumour staging for colorectal cancer (CRC) is to help define clinical management, facilitate communication between physicians, provide a basis for stratification and analysis of treatment results in prospective studies, and provide some prognostic information for patients and their families. The World Congresses of Gastroenterology, Digestive Endoscopy, and Coloproctology, Working Party on staging for CRC studied six commonly used systems to review their strengths and weaknesses. Although it was concluded that defining a new staging system was unnecessary, it was recognized that there is a need to define a terminology to describe the full anatomic extent of spread of CRC. Furthermore, we note that there are several additional features, derived from both clinical and pathology information, which have had prognostic significance shown by appropriately constructed multivariate analyses and which can be used to formulate a more accurate prognostic index than that provided by a description of anatomical tumour spread. Thus the Working Party came to two principal conclusions. First, a standard format should be adopted for the collection of the essential data required for prospective studies, and we recommend the 'International Documentation System (IDS) for CRC' for this purpose. Second, a nomenclature which describes the full anatomical extent of tumour spread and residual tumour status in CRC has been defined and should be adopted, from which all currently used staging systems can be derived. We have called this nomenclature the 'International Comprehensive Anatomical Terminology (ICAT) for CRC'. In the event that these recommendations are adopted, we envision that there will be improved clarity in the documentation of treatment outcome for patients with CRC and improved communication of results derived from prospective studies. Furthermore, an acceptance of IDS and ICAT would set the scene to develop a prognostic index for individual patients with CRC by the expansion of anatomical clinicopathology staging information to include additional factors which have independent prognostic significance.

Cystic fibrosis: current survival and population estimates to the year 2000.

Abstract: BACKGROUND: Survival from cystic fibrosis is increasing rapidly. Estimates of the extent of this improvement should allow health care facilities to be planned to deal with the expanding population of patients with cystic fibrosis. Estimates of life expectancy are also essential if accurate information on current prognosis is to be given to parents of an affected child, or to prospective parents deciding whether to proceed with a pregnancy where the fetus may be affected. METHODS: Survival trends in the national data on cystic fibrosis have been analysed to produce estimates of the likely size of the cystic fibrosis population over the next decade and to predict the life expectancy of children born with cystic fibrosis in the years up to 1990. RESULTS: In England and Wales the estimated number of patients with cystic fibrosis is at present about 5200, of whom 3300 (63%) are aged under 16 years. By the year 2000 the total population will increase to 6000, with 3400 (57%) aged under 16. Thus the number of children with cystic fibrosis will remain fairly constant over the next 10 years, whereas adult numbers will increase by about 36% (from 1901 to 2577). The median life expectancy of children with cystic fibrosis born in 1990 is estimated to be 40 years, double that of 20 years ago. CONCLUSION: This study suggests that health service provision for children will not need to change substantially over the next 10 years whereas services for adults will need to increase by about a third. Parents can be counselled that the median life expectancy of a newborn child with cystic fibrosis is currently likely to be of the order of 40 years.

Democracy, Bureaucracy and Public Choice: Economic Explanations in Political Science

Abstract: * Introduction: Institutional Public Choice Theory and Political Analysis DEMOCRACY * Interest Groups and Collective Action * Reconstructing the Theory of Groups * Economic Explanations of Voting Behaviour * Party Competition - The Preference-Shaping Model BUREAUCRACY * Existing Public Choice Models of Bureaucracy * The Bureau-Shaping Model * Comparing Budget - Maximizing and Bureau-Shaping Models * Conclusion - Economic Explanations in Political Science

Biodegradable microparticles as controlled release antigen delivery systems.

Abstract: A model but poor immunogen, ovalbumin (OVA), was entrapped in a novel antigen delivery system comprising poly (D,L-lactide-co-glycolide) (PLGA) microparticles Both the primary and the secondary IgG antibody responses obtained with OVA in microparticles were compared to those obtained with OVA emulsified in Freunds' adjuvants by two routes of immunization, intraperitoneal (ip) and subcutaneous (sc) injection Following single ip or sc injections, the IgG serum antibody responses to OVA in microparticles were significantly greater than the responses to OVA in Freunds' complete adjuvant (FCA) for up to 10 weeks After sc booster doses of OVA, the secondary IgG antibody responses to OVA in microparticles remained greater than the secondary responses to OVA in Freunds', but not significantly so Furthermore, the primary IgG responses to OVA in microparticles obtained 8-12 weeks after a single ip injection were greater than the secondary responses to OVA in Freunds' obtained by repeat sc injections at Weeks 0 and 6 These results demonstrate that microparticles can function as potent antigen delivery systems for an entrapped antigen Due to their ability to degrade slowly in vivo and to release entrapped antigens, microparticles have considerable potential as controlled release antigen delivery systems for the induction of long-term immune responses

Variation in Gastrointestinal Transit of Pharmaceutical Dosage Forms in Healthy Subjects

Abstract: The variability in the gastrointestinal transit of a multiple-unit and single-unit dosage form was investigated following a light breakfast in six, healthy, male volunteers after repeated weekly administration. The dosage forms were labeled with gamma-emitting radionuclides and the transit of the formulations was monitored on 4 separate study days using the technique of dual-isotope gamma scintigraphy. Gastric emptying times and small intestinal transit times were calculated and compared statistically within and between subjects using the standard deviation and coefficient of variance. The variability in gastric emptying of single- and multiple-unit systems was large; the intrasubject variation being less than the intersubject. There was less variation in small intestinal transit times for the single- and multiple-unit formulations than in gastric emptying, intrasubject variation again being less than intersubject variation.

Combining archaeological and radiocarbon information: a Bayesian approach to calibration

Abstract: A recent and significant improvement in radiocarbon dating has been the increased ability of the radiocarbon laboratories to provide results combining precision with accuracy. This improvement has been accompanied by increasing recognition that the information must be expressed on the calendar, rather than on the radiocarbon, time-scale. Despite the attempts of Ottaway (1987) and Pearson (1987), archaeologists are not sufficiently aware of the statistical problems involved in the transformation from one scale to the other: ‘Some of the trouble lies in the ignorance of radiocarbon consumers; the many attempts to educate them can have only limited success when radiocarbon study depends on statistical concepts and methods far beyond the average archaeologist’s innumerate grasp’ (Chippindale 1990: 203).

Identification of a tomato gene for the ethylene-forming enzyme by expression in yeast

Abstract: The ethylene-forming enzyme (EFE), which catalyzes the last step in the biosynthesis of the plant hormone ethylene, has never been purified and no molecular probes are available. Recently, a putative cDNA clone for tomato EFE (pTOM13) has been identified by inhibiting ethylene synthesis with an antisense gene expressed in transgenic plants. A direct test of its function has been made by expression of a pTOM13 gene in Saccharomyces cerevisiae. After cloning artefacts were discovered in the 5' region of the cDNA, a corrected cDNA (pRC13) was created by the fusion of the 5' end of a genomic clone to the 3' end of the cDNA and expressed in S. cerevisiae. Cultures of transformed yeast converted 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, whereas control cells did not. This EFE activity displays similar characteristics to EFE found in plant tissue: it converts the trans isomer of the ACC analogue 1-amino-2-ethylcyclopropane-1-carboxylic acid to 1-butene in preference to the cis isomer, and it is strongly inhibited by cobaltous ions and 1,10-phenanthroline. Furthermore, information gained from the activity of effectors on yeast EFE activity supports the hypothesis that EFE is one of a group of hydroxylase enzymes.

Sedation for upper gastrointestinal endoscopy: results of a nationwide survey.

Abstract: A postal questionnaire inquiring about routine sedation and premedication practice for upper gastrointestinal endoscopy was sent to 1048 doctors. Of 665 appropriate returns, 81% were from consultant physicians and surgeons. Most endoscopists (90%) reported using an intravenous benzodiazepine for at least three quarters of endoscopies and 54% of physicians and 69% of surgeons always did so. Midazolam was the intravenous sedative used by a third of all respondents and 13% also used an additional intravenous agent, usually pethidine. Over the previous two years a total of 119 respiratory arrests, 37 cardiac arrests, and 52 deaths were identified. Adverse outcomes were reported more frequently by consultant physicians, by those who 'titrated' the intravenous sedative, and by those who used an additional intravenous agent, but were reported equally frequently by endoscopists using midazolam and endoscopists using diazepam. There is an urgent need for a prospective study to identify the circumstances and risk factors associated with adverse outcomes related to endoscopy.

c-erbB-2 oncoprotein expression in primary and advanced breast cancer

Abstract: Immunoreactivity for c-erbB-2 oncogene product expression has been investigated in patients with breast cancer using the polyclonal antibody 21N. Three series of patients were studied, 602 presenting with primary operable cancer, 57 with stage 3 and 123 with stage 4 disease. Representative tissue sections of each primary tumour were stained using a standard immunoperoxidase technique. Invasive tumour membrane immunoreactivity was assessed and identified in 15% of patients with primary operable cancer and 20% in the advanced breast cancer group. The results demonstrate a relationship between poorer survival and oncogene expression in all three patient groups. Patients in the primary operable cancer group with membrane oncoprotein expression had a poorer outcome, 35% 10-year survival, compared with those in which membrane expression was absent, 55% 10-year survival. The median survival of patients with stage 3 disease with c-erbB-2 membrane positivity was 17 months compared to 24 months with membrane negativity. In stage 4 disease median survival with membrane expression was 8.8 months compared to 19.7 months with no membrane expression. In addition in the series of primary cancers a correlation existed between histological grade and membrane immunoreactivity. Multivariate analysis showed histological grade to be a more powerful prognostic factor than c-erbB-2 protein expression. In conclusion, this study demonstrates, in a large series of patients presenting to one centre, that c-erbB-2 protein expression is a prognostic indicator in patients with primary operable and advanced breast disease.

An Association between Fertility and Cuckoldry in the House Sparrow, Passer domesticus

Abstract: DNA fingerprinting of 183 broods of house sparrows and their attendant adults revealed that 136% of nestlings were unrelated to the attendant male The occurrence of cuckoldry was unaffected by male age and experience, pair bond duration or time within a breeding season However, cuckoldry was significantly more frequent in broods that included some infertile eggs This study suggests that sperm competition can be strongly influenced by the fertility of the cuckolded male, and that females may benefit from extra-pair copulation as an insurance against their mate9s infertility

Conjugational recombination in resolvase-deficient ruvC mutants of Escherichia coli K-12 depends on recG

Abstract: ruvC mutants of Escherichia coli appear to lack an activity that resolves Holliday intermediates into recombinant products. Yet, these strains produce close to normal numbers of recombinants in genetic crosses. This recombination proficiency was found to be a function of recG. A "mini-kan" insertion in recG was introduced into ruvA, ruvB, and ruvC strains. Conjugational recombination was reduced by more than 100-fold in recG ruvA::Tn10, recG ruvB, and recG ruvC strains and by about 30-fold in a recG ruvA strain carrying a ruvA mutation that is not polar on ruvB. The double mutants also proved very deficient in P1 transduction and are much more sensitive to UV light than ruv single mutants. Since mutation of recG alone has very modest effects on recombination and sensitivity to UV, it is concluded that there is a functional overlap between the RecG and Ruv proteins. However, this overlap does not extend to circular plasmid recombination. The possibility that RecG provides a second resolvase that can substitute for Ruv is discussed in light of these findings.

Physicochemical properties of sweet potato starch

Abstract: Tropical root crops, of which the sweet potato is an important representative, constitute an under exploited resource of developing countries They can be used as food for both human and animal consumption and their starch is a source of industrial raw material This review will consider recent reports on sweet potatoes, the physicochemical properties of their starches in comparison with other starches, and the possible causes of variation in these characteristics

Geodetic determination of tectonic deformation in central Greece from 1900 to 1988

Abstract: The Global Positioning System has been used to measure the relative displacements of fifteen monuments in a hundred-year-old triangulation network spanning part of the Aegean extensional basin. These displacements reflect the tectonic deformation of the region over the past century, showing more than one metre of north-south extension across the network. The crust in this region appears to contain a few slowly deforming blocks separated by more rapidly deforming zones.

The costs and benefits of ‘computer addiction’

Abstract: The research was inspired by comments from the press and concerned academics who suggested that computer use could convert 'normal' people into antisocial, machine-code junkies. Contrary to such opinions, the computer-dependent individuals who took part in the study were intelligent, interesting, hospitable, but misunderstood people, who from experience had learned to mistrust humans. Instead from an early age, they had turned to the safe and predictable world of the inanimate, and by exploring their environments had become true scientists and philosophers. Their responses were far from neurotic, instead they were logical coping strategies which allowed them to make sense of the world within which they lived. They were pursuing an interest which not only provided intellectual challenge and excitement in infinite variety, but for most also enabled them to turn a fascinating hobby into a successful means of earning a living; an ideal to which most would aspire.

Distribution of collagenase and tissue inhibitor of metalloproteinases (TIMP) in colorectal tumours.

Abstract: Increased collagenase activity in colorectal carcinomas has recently been shown to be associated with increased malignant potential. To determine the tissue distribution of collagenase and its specific inhibitor, tissue inhibitor of metalloproteinases (TIMP), we carried out an immunohistochemical study on colorectal carcinomas (n = 20), adenomas (n = 7) and normal mucosa (n = 6). We found increased staining for collagenase in the connective tissue stroma of carcinomas, as compared with adenomas and normal mucosa. Little evidence of epithelial cell staining for collagenase was seen in any tissue. In carcinomas, both stromal fibroblasts and collagen fibres stained strongly and stromal staining was strongest close to neoplastic glands. Vascular staining was more prominent in neoplastic than normal tissues, perhaps reflecting the increased proteolytic activity during tumour angiogenesis. The pattern of TIMP immunostaining was similar to that of collagenase, although basement membrane staining for TIMP was generally more intense. Another difference was that, unlike TIMP, staining for collagenase was often increased at the invasive edge of carcinomas, perhaps reflecting increased collagenase activity at this location.

Industrialisation, catching up and economic growth: a comparative study across the world's capitalist economies*

Abstract: Various hypotheses are examined seeking to explain inter-country convergence at the upper end, but divergence at the lower end, of the world income rankings. A model of disequilibrium growth with sector-specific technological progress and spillover is developed and then estimated on two samples of capitalist economies 1960-85. It is found that the degree of disequilibrium between agriculture and industry is greatest in the least developed economies, but their rate of labor transfer has been slow. Technological spillover has stimulated productivity growth in less developed agricultural sectors, but not in the industrial sectors of the least developed economies. Copyright 1991 by Royal Economic Society.

Magnetic resonance imaging (MRI) and model-free estimates of brain volume determined using the Cavalieri principle.

Abstract: A complete set of parallel (coronal) slices through a fixed human forebrain was generated by magnetic resonance imaging (MRI) and the Cavalieri principle, combined with point counting, was used to estimate brain volume. Alternative sampling schemes for estimating volume were then assessed by taking systematic and simple random selections of slices. Later, the brain was weighed and its fixed volume determined by fluid displacement. For the complete set of n = 28 MRI slices, the volume (1025 ml) was estimated with a coefficient of error (CE) of less than 1%. Decreasing the number of slices by systematic sampling increased the CE but this was still only 5% when just 5-6 slices were analysed. Estimated volumes varied from 947 ml to 1098 ml. Simple random sampling was less efficient (estimated volumes for 5-6 slices were 644-1187 ml). The forebrain actually weighed 1090 g and displaced 1060 ml of fluid. A set of 14 other brains was physically sliced in order to assess sampling errors in the context of observed brain-to-brain variation. It was found that 5-6 slices per brain is enough to yield efficient estimates of mean brain volume. The findings demonstrate the practicability of using MRI to estimate brain volumes unbiasedly and efficiently. The methods have great potential for noninvasive, longitudinal studies on in vivo brains and other organs.