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Biomedical subjects

A S Jones

Publications and source records attributed to A S Jones.

At least 19 recordsLinked to original sources
PubMed2006

Airway dimensions measured from micro-computed tomography and high-resolution computed tomography.

Volume averaging results in both over- and underestimation of airway dimensions when they are measured by high-resolution computed tomography (HRCT). The current authors calibrated computerised measurements of airway dimensions from HRCT against a novel three-dimensional micro-computed tomography (CT) standard, which has a 50-fold greater resolution, as well as against traditional morphometry. Inflation-fixed porcine lung cubes were scanned by HRCT and micro-CT. A total of 59 lumen area (Ai), 30 wall area (A(aw)) and 11 lumen volume (Vi) measurements were made. Ai was measured from the cut surface of 11 airways by morphometry. Airways in scanned images were matched using branching points. After calibration, the errors of Ai, A(aw) and Vi HRCT measurements were determined. The current authors found a systematic, size-dependent underestimation of Ai and overestimation of A(aw) from HRCT measurements. This was used to calibrate an HRCT measurement algorithm. The 95% limits of agreement of subsequent measurements were +/-3.2 mm2 for Ai, +/-4.3 mm2 for A(aw), and +/-11.2 mm3 for Vi with no systematic error. Morphometric measurements agreed with micro-CT (+/-2.5 mm2) without systematic error. In conclusion, micro-computed tomography image data from inflation-fixed airways can be used as calibration standards for three-dimensional lumen volume measurements from high-resolution computed tomography, while morphometry is acceptable for two-dimensional measurements. The image dataset could be used to validate other developmental three-dimensional segmentation algorithms.

Animals↗
PubMed2005

How we do it: a series of 114 primary pharyngeal space neoplasms.

Primary parapharyngeal space tumours are exceedingly rare. We present a series of 114 parapharyngeal space tumours, the second largest in the literature. The most frequent benign tumours were pleomorphic adenoma (34) and paraganglioma (33); the commonest malignancies were of salivary gland origin (12). The 5- and 10-year survival for benign tumours was 100%. The 5- and 10-year survival for malignancies was 93% and 57% respectively. The importance of long-term follow-up is evidently crucial.

Adenoma, Pleomorphic↗
PubMed2005

Matrix metalloproteinases and their inhibitors in non-neoplastic otorhinolaryngological disease.

Matrix metalloproteinases (MMPs) are a family of zinc and calcium-dependent endopeptidases that play a key role in extracellular matrix (ECM) degradation. MMPs are known to be important in normal remodelling processes. Overexpression and activation of MMPs or an imbalance of active MMPs and tissue inhibitors of metalloproteinases (TIMPs) has been linked with a number of specific disease states associated with the breakdown and remodelling of the extracellular matrix. MMPs and TIMPs play a role in the development and progression of conditions such as acute and chronic otitis media, nasal polyposis and Sjogren's disease of salivary glands. Their role in allergic rhinitis has not been proven although they do appear to have a role in asthma, a condition closely linked to rhinitis. The use of a broad spectrum MMP inhibitor has been shown to alter the outcome of acute otitis media and otitis media with effusion. Therapeutic strategies with anti-MMP molecules are currently being developed and may play a role in modulating the course of non-neoplastic otorhinolaryngological disease in the future.

Ear Diseases↗
PubMed2005

Passive smoking, allergic rhinitis and nasal obstruction in children.

Allergic rhinitis is a common cause of nasal obstruction in childhood. This prospective study looked at the effect of passive smoking on nasal obstruction in children with and without allergic rhinitis. Eighty-one children took part. Each child was asked to score his or her degree of nasal obstruction on a visual analogue scale. Exposure to passive smoking was determined subjectively using a parental questionnaire, and objectively by measuring the urinary cotinine/creatinine ratio. Results were tabulated using Microsoft Excel and analysed with SPSS statistical software. Nasal obstruction was significantly worse in children with a positive history of allergic rhinitis (p < 0.05). There was also a trend towards a higher nasal obstruction score in children without allergic rhinitis exposed to passive smoking compared to those who were not so exposed. As would be expected, nasal obstruction is worse in children with allergic rhinitis than in those without. Passive smoking tends to increase the symptom of nasal obstruction in children without allergic rhinitis.

Adolescent↗
PubMed2004

Root resorption and its association with alterations in physical properties, mineral contents and resorption craters in human premolars following application of light and heavy controlled orthodontic forces.

OBJECTIVES: To study the effect of different orthodontic force levels on cementum, investigating from the point of view of its physical properties, alterations in the mineral components, type and location of the resorption craters and the exploration in 3D of space. DESIGN: In vivo human premolars subjected to heavy and light forces were employed for this study. After a period of movement they were analyzed for hardness and elasticity. Also, the mineral composition measuring Ca, P and F of the cementum root surface was investigated. A new method for volumetric analysis of resorption craters was developed. RESULTS: There were no significant differences for hardness and elastic modulus between the light and heavy force groups and no significant effects for different tooth positions. Significant inter-individual variation in the Ca, P and F concentrations was noted. Force-related data showed that mean volume of the resorption crater in light-force group was 3.49-fold greater than the control group, and the heavy-force group 11.59-fold more than control group. The heavy force group had 3.31-fold greater total resorption volume then light force group. Buccal cervical and lingual apical regions demonstrated significantly more resorption craters than the other regions. The 2D measurements were strongly correlated to 3D measurements. CONCLUSION: The application of light and heavy forces did not show any statistically significant differences in hardness and elastic modulus when compared with untreated teeth. The inconsistent increase or decrease of Ca, P and F contents between control and experimental teeth at sites of compression and tension were difficult to explain. There was more resorption by volume in the heavy force group as compared with the light group and controls. Our data also suggested that the high-pressure zones might be more susceptible to resorption after 28 days of force application.

Adolescent↗
PubMed2003

Allelic imbalance at the DNA mismatch repair loci, hMSH2, hMLH1, hPMS1, hPMS2 and hMSH3, in squamous cell carcinoma of the head and neck.

BACKGROUND: Squamous cell carcinoma of the head and neck (SCCHN) is one of the 10 most frequently occurring cancers in the world. Defective mismatch repair, as exhibited by the phenomenon of microsatellite instability, has been observed in SCCHN although no reports of mismatch repair gene mutations or altered protein expression have been published. In a variety of microsatellite instability (MSI) positive cancers where mutations in the mismatch repair (MMR) genes were not observed, allelic imbalance at the loci of the MMR genes was prevalent. OBJECTIVE: To investigate whether allelic imbalance at the MMR genetic loci contributes to the development of SCCHN. MATERIALS AND METHODS: 35 matched normal/tumour SCCHN pairs were studied using 29 microsatellite markers located within and adjacent to six known DNA mismatch repair genes. In addition, mutational analysis and protein expression of hMSH2 and hMLH1 were investigated. RESULTS AND CONCLUSIONS: We demonstrated that 36 and 17% of the analysed SCCHN specimens exhibited allele imbalance at the hMLH1 and hMSH3 genetic loci, respectively. Allelic instability at these two loci was found to be correlated with the MSI status of the SCCHN tumours. Allelic instability was found to be uncommon at the other MMR gene loci analysed. One mutation was found in hMSH2 and none in hMLH1 in this series of tumours. 23 of 24 (96%) of the examined SCCHN tumours showed reduced expression of either hMSH2 or hMCH1 genes. Allelic instability in the MMR genes, hMLH1 and hMSH3, is proposed to be involved in the aetiology of SCCHN tumours.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Lymph node metastases in the lower neck.

Current knowledge suggests that lymph node metastases in the lower neck (supraclavicular fossa and posterior triangle) are associated with a poor survival. Very little systematic work has been published on this subject. This was a retrospective study carried out on a database where all patients were entered in a prospective manner over a 35-year period using a standard pro-forma. Data on 168 patients presenting with a lower neck node metastasis were retrieved. The main outcome measures were: association between variables and tumour-specific survival. Data were displayed in contingency tables and analysed by chi-square and categorical modelling. Recurrence and survival were plotted in a cause-specific manner using the Kaplan Meir method. Differences in curves were analysed using the log rank test. Multivariate analysis was carried out using Cox's proportional hazard model. The only association was between site and node level and histology. Head and neck tumours were associated with squamous histology (P = 0.0004) and supraclavicular nodes (P = 0.0047). Survival time was not significantly different when lower-neck lymph node metastasis from the head and neck was compared to non-head and neck metastasis: 5-year survival 30% and 10% respectively (P = 0.1363). Survival with posterior triangle metastases was significantly better than supraclavicular metastases (P = 0. 0059), confirmed on multivariate analysis. Laterality of metastasis had no effect on survival (P < 0.0001). There was no significant difference in survival between squamous and non-squamous metastases on Cox regression (P = not significant). There were 85 head and neck primaries including lymphomas, 53 infraclavicular primaries and 30 unknown primaries. There were 73 squamous cell carcinomas, 27 adenocarcinomas, 34 lymphomas, 28 undifferentiated tumours and six other tumours. Nearly half the primary tumours were below the clavicle. Survival was unaffected by laterality, primary site or histology, but was better for posterior triangle nodes.

Adenocarcinoma↗
PubMed2002

Oropharyngeal carriage and lower airway colonisation/infection in 45 tracheotomised children.

BACKGROUND: A study was undertaken to determine the oropharyngeal carrier state of potentially pathogenic microorganisms (PPM) and the magnitude of colonisation and infection rates of the lower airways with these PPM in children requiring long term ventilation first transtracheally and afterwards via a tracheotomy. METHODS: A 5 year, prospective, observational cohort study was undertaken in 45 children (33 boys) of median age 6.4 months (range 0-180) over a 5 year period at the Royal Liverpool Children's NHS Trust of Alder Hey, a university affiliated tertiary referral centre. The children were first admitted to the 20-bed paediatric intensive care unit (PICU) and, following placement of a tracheotomy, they were transferred to a four bedded respiratory ward. The two main indications were neurological disorders and airway obstruction. All children were ventilated transtracheally for a median period of 12 days (range 0-103) and, after placement of the tracheotomy, for a similar period of 12 days (range 1-281). Surveillance cultures of the oropharynx were taken on admission to the PICU and on the day of placement of the tracheotomy. Throat swabs were taken twice weekly during ventilation, both transtracheal and via the tracheotomy. Tracheal aspirates were taken once weekly and when clinically indicated (in cases where the lower airway secretions were turbid). RESULTS: Twenty five patients (55%) had abnormal flora, mainly aerobic Gram negative bacilli (AGNB), particularly Pseudomonas aeruginosa, while the community PPM Staphylococcus aureus was present in the oropharynx of 37% (17/45) of the study population. The lower airways were sterile in six children; the other 39 patients (87%) had a total of 82 episodes of colonisation. "Community" PPM significantly increased once the patients received a tracheotomy, independent of the number of patients enrolled, episodes of colonisation/infection, and the number of colonised/infected patients. "Hospital" PPM significantly decreased after tracheotomy only when episodes were compared. CONCLUSIONS: While P aeruginosa present in the admission flora caused primary endogenous colonisation/infection during mechanical ventilation on the PICU, S aureus not carried in the throat was responsible for the exogenous colonisation/infection once the patients had a tracheotomy. This is in sharp contrast to adult studies where exogenous infections are invariably caused by AGNB. This discrepancy may be explained by chronic underlying conditions such as diabetes, alcoholism, and chronic obstructive pulmonary disease which promote AGNB, whereas the children were recovering following tracheotomy.

Adolescent↗
PubMed2002

Citation analysis of otorhinolaryngology journals.

Bibliometric analysis is used to assess the 'impact' of scientific journals. The commonest method of evaluation is impact factor. The aim of this study was to analyse the citation data for otorhinolaryngology journals of the years 1994 to 1998. Data on the total number of citations and impact factor of journals was obtained from the CD-ROM editions 1994-98 of the Journal Citation Reports and 'Web of Science' database. The adjusted impact factor and five-year impact factor has been calculated. Fifteen otorhinolaryngology journals have been identified and ranked according to the impact factor. Head and Neck has the highest adjusted impact factor. Archives of Otolaryngology - Head and Neck Surgery has the highest five-year impact factor. There is considerable variation in the ranking of journals calculated by the five-year impact factor. Impact factors of otolaryngology journals can help to direct readers to those journals that have a track record of publishing data that are frequently cited. Although there are several limitations to the use of citation data to rank journals, the authors recommend the use of the five-year period for calculation of the impact factor for ranking of otolaryngology journals.

Bibliometrics↗
PubMed2002

A century of citation classics in otolaryngology-head and neck Surgery journals.

The Science Citation Index (SCI) was introduced primarily as a method of information retrieval but has also been used an objective measure of the quality of an article. Citation classics have been described as papers that have been cited 100 times or more. The aim of this study was to identify the articles published during the 20th century in otolaryngology-head and neck surgery journals that have achieved classic citation status and to present an analysis of this data. Using a database provided by the Institute of Scientific Information (Philadelphia, PA), an assessment was performed of all articles cited 100 or more times in one of the 28 clinical otolaryngology-head and neck journals indexed by the annual Journal Citation Reports. The data were based on citation counts using the 1900 through 1999 Science Citation Index. Institutions located in 10 different countries produced 80 noteworthy articles. The most-cited paper achieved a citation score of 406 and there were 11 articles cited on more than 200 occasions. All of the articles were published in eight journals. The earliest identified publication was in 1933 and the most recent was published in 1993. Twenty authors were involved in two articles and four authors were associated with three classic citations. This paper confirms that analysing citation classics reveals a partial insight into advances and historical developments in the specialty during the last century.

Bibliometrics↗
PubMed2001

Applying cost analysis methods to school-based prevention programs.

In order to efficiently allocate scarce prevention resources, policymakers need information about the economic costs of school-based substance use prevention programs. The objective of this paper is to outline economic cost analysis methods and demonstrate their applicability to school-based prevention programs. As an example, the paper focuses on estimating the economic cost of ALPHA, an intensive school-based substance use prevention program. The cost of ALPHA is compared to the costs of 3 elementary school programs that were alternatives to ALPHA. We collected cost information for 3 years, using a cost questionnaire that was completed by program and school budget officers and school principals. The program costs obtained from these sources were modified to conform to well-established economic cost analysis principles.

Child↗
PubMed2001

The accuracy of MEDLINE and Journal contents pages for papers published in Clinical Otolaryngology.

MEDLINE is widely used as a source for identifying and reviewing medical journal literature. Its accuracy is generally taken for granted, as is that of the contents pages published by the journals themselves. In this study of citation accuracy we examined the articles published in Clinical Otolaryngology and Allied Sciences from 1976 to 1998. The entries in MEDLINE were compared with the entries in the Journal's contents pages, and with the actual articles. Of 1651 articles published in the journal, one was omitted from MEDLINE and 25 (1.5%) were incorrectly cited, while 88 (5.3%) were incorrectly cited in the contents pages. Twenty-one (84%) of the errors in MEDLINE involved names of authors. Apart from incomplete retrieval of information for practice and research, errors could result in an author not getting credit for publications.

Abstracting and Indexing↗
PubMed2001

An overview of the role and inter-relationship of epidermal growth factor receptor, cyclin D and retinoblastoma protein on the carcinogenesis of squamous cell carcinoma of the larynx.

Recent developments in both molecular and cellular biology have improved the understanding of the tumorigenesis of laryngeal squamous cell carcinoma. Loco-regional recurrence of this condition still poses a significant oncological management dilemma for a subset of these tumours. Therefore, the possibility that specific tumour characteristics (demonstrable by immunohistochemical and molecular biological study) may aid the clinician in choosing the optimal treatment for a specific tumour holds great promise. This article concentrates on the role and inter-relationship of epidermal growth factor receptor status on the function of cyclin D, and how this is related to the presence of retinoblastoma protein. A review of recent studies evaluating these markers, the potential clinical utility of these findings and the possible directions for further study are discussed.

Carcinoma, Squamous Cell↗
PubMed2001

A report of 50 patients with carcinoma of the hypopharynx treated by total pharyngolaryngo-oesophagectomy repaired by gastric transposition.

Extensive carcinoma of the hypopharynx requires aggressive surgery, which can lead to loss of function and a high morbidity and mortality. This paper reports 50 patients with carcinoma of the hypopharynx treated with total pharyngolaryngo-oesophagectomy and gastric transposition. Thirty-two patients had primary surgery and 18 had salvage surgery for recurrence following radiotherapy. Two technical modifications to the standard procedure that have evolved during this period are the use of a diverticuloscope for dissection of the middle third of the oesophagus and the routine insertion of chest drains peroperatively. Complications were relatively unusual in the primary surgery group, but were a problem in those patients undergoing salvage surgery. Stenosis did not tend to occur with gastric transposition repair, but three patients had delayed gastric emptying with prolonged hospital stays. The tumour-specific actuarial survival at 4 years was 39% and the observed survival was 25%. Pharyngolaryngo-oesophagectomy and gastric transposition is becoming safer owing to increased multidisciplinary experience in this form of surgery. Survival is improved with the use of postoperative radiotherapy in patients undergoing primary surgery.

Carcinoma, Squamous Cell↗
PubMed2001

The program effect of batterer programs in three cities.

Recent meta-analyses and experimental designs of batterer program evaluations suggest little or no program effect. This finding may be compromised by a variety of analytical issues. Instrumental variable analysis addresses some of these issues, especially the relationship of program dropout to batterer reassault. This method of analysis was, therefore, used to test for program effect in a multi-site evaluation. The sites were three well-established batterer programs using a gender-based, cognitive-behavioral approach (n = 640). Completing a batterer program reduced the likelihood of reassault by 44% to 64%, depending on the specification used. Completing a 3-month program appeared to be as effective as completing a 5 1/2- or 9-month program. This moderate effect is an accomplishment considering the problems associated with the program participants and the inconsistency in the criminal justice system at the research sites. The findings remain tentative because of weak instrumental variables for reassault, but do confirm the need for more complex analyses of program effect.

Colorado↗