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Biomedical subjects

G Naylor

Publications and source records attributed to G Naylor.

At least 19 recordsLinked to original sources
PubMed2005

Digit preference in Goldmann applanation tonometry: the hedgehog effect.

PURPOSE: Digit preference is a subconscious bias towards numbers that end in certain digits. We conducted a study to assess for digit preference in intraocular pressure measurement using the Goldmann applanation tonometer. DESIGN: Prospective study with masked and unmasked phases. METHODS: The study was conducted in general ophthalmic clinics in a District General Hospital in Blackpool, United Kingdom, by 6 clinical ophthalmologists. Consecutive right eye intraocular pressure measurements were collected for a 2-month period for the masked phase and were repeated for the unmasked phase. The proportion of even numbers was the main outcome measure. RESULTS: Six ophthalmologists completed both phases: 555 of 917 readings were even in the masked phase (P = .075), and 679 of 1056 readings were even in the unmasked phase (P = .022). CONCLUSIONS: Our results suggest that digit preference influences measurements from the Goldmann applanation tonometer and that this persists when observers are aware of digit preference. This bias may influence both clinical decision-making and trial results.

Bias↗
PubMed2003

Setting up a quality assurance program in endoscopy.

BACKGROUND: Both patients and government demand proof of quality of care and value for money. Our unit ist in a large teaching hospital, performing over 6000 procedures per year. We have designed and implemented a Quality Assurance (QA) program, the basis of which we believe could be a model for endoscopy QA. METHODS: A QA team was formed and a literature search undertaken. An initial 3 month audit was then performed into indications for, and complications of, all procedures. The results of this initial audit led us to concentrate on colonoscopy and ERCP. The specific items of data collected were based on the "Core Quality Indicators" developed by the American Society for Gastrointestinal Endoscopy (ASGE). We also analysed data relating to endoscope disinfection, equipment failure and carried out a patient satisfaction survey. The data were presented at 3-monthly QA meeting, and appropriate action taken. RESULT: We performed a detailed audit of ERCP (217 procedures) and colonoscopy (904 procedures). Patients risk was stratified using the American Society of Anaesthesiology (ASA) classification. Using these data we established our technical success and complication rates for colonoscopy and ERCP. Audit of equipment revealed that on average an endoscope was away for repair 9 % of the time. Contamination of endoscopes was frequent with glutaraldehyde disinfection; the rate of contamination fell dramatically when we changed our disinfection method. CONCLUSION: A QA program can be implemented in busy endoscopy units. There are significant problems, however, in ensuring that such a program is effective: these include inadequate funding/staffing, lack of suitable information technology and lack of clear guidelines for dealing with poor performance.

Endoscopy↗
PubMed2002

Evaluation of posturing in macular hole surgery.

AIM: To objectively evaluate the postoperative face down posturing in macular hole surgery. MATERIALS AND METHODS: An electronic device called 'Maculog' was developed consisting of three basic components, a mercury switch triggered by the angle of tilt placed inside an earpiece, a data-recording device connected to the earpiece with cables and a windows based software program, specially written to analyse the recorded data in the form of tables and graphs. Ten patients undergoing macular hole surgery were fitted with the device on the first postoperative day before discharge. They were also asked for a subjective record of their posturing times. Four patients were given a posturing chair to take home. The device was retrieved after the first week and the data were downloaded to a PC for analysis. The actual posturing times recorded on the device were compared to the patients' own recollections. Results In all ten patients the actual posturing time was less than the time they had recorded themselves. The average actual posturing time was 48% of the perceived posturing time. The worst time for posturing, as expected, was between midnight and early morning. The compliance was better in patients who used the posturing chair. CONCLUSIONS: It is feasible to quantify the time of posturing using an electronic device and computer analysis. The study has shown that the actual posturing time is significantly less than the perceived posturing time. A further large study using 'Maculog' is now planned to correlate actual posturing time to the results of macular hole surgery.

Aged↗
PubMed2002

Dietary antioxidants and DNA damage in patients on long-term acid-suppression therapy: a randomized controlled study.

Free radicals and reactive species produced in vivo can trigger cell damage and DNA modifications resulting in carcinogenesis. Dietary antioxidants trap these species limiting their damage. The present study evaluated the role of vitamins C and E in the prevention of potentially premalignant modifications to DNA in the human stomach by supplementing patients who, because of hypochlorhydria and possible depletion of gastric antioxidants, could be at increased risk of gastric cancer. Patients undergoing surveillance for Barrett's oesophagus (n 100), on long-term proton pump inhibitors were randomized into two groups: vitamin C (500 mg twice/d) and vitamin E (100 mg twice/d) for 12 weeks (the supplemented group) or placebo. Those attending for subsequent endoscopy had gastric juice, plasma and mucosal measurements of vitamin levels and markers of DNA damage. Seventy-two patients completed the study. Plasma ascorbic acid, total vitamin C and vitamin E were elevated in the supplemented group consistent with compliance. Gastric juice ascorbic acid and total vitamin C levels were raised significantly in the supplemented group (P=0.01) but supplementation had no effect on the mucosal level of this vitamin. However, gastric juice ascorbic acid and total vitamin C were within normal ranges in the unsupplemented group. Mucosal malondialdehyde, chemiluminescence and DNA damage levels in the comet assay were unaffected by vitamin supplementation. In conclusion, supplementation does not affect DNA damage in this group of patients. This is probably because long-term inhibition of the gastric proton pump alone does not affect gastric juice ascorbate and therefore does not increase the theoretical risk of gastric cancer because of antioxidant depletion.

Achlorhydria↗
PubMed1999

Using the business excellence model to develop a strategy for a healthcare organisation.

This article examines the appropriateness of the Business Excellence Model in developing a strategy for Bolton Hospitals NHS Trust to measure organisational performance. The need for a strategy to measure organisational performance and to improve organisational performance was highlighted with the production of the Government White Paper, The New NHS: Modern and Dependable. At the heart of recommendations there is emphasis on improving quality and driving efficiency. Greater emphasis will be placed on organisations measuring their performance. By utilising the conceptual framework, which consisted of The European Foundation for Quality Management (EFQM) Model, it became evident that, although tools were in existence within Bolton Hospitals to measure organisational performance, several critical areas needed addressing. By addressing these key areas, the organisation could begin to work towards its goal of business excellence. The conclusions drawn from this project demonstrated that there was scope for Bolton Hospitals to improve on organisational performance. It was highlighted that the Trust was functioning well in some areas of the EFQM Model, but not in others. For Bolton Hospitals NHS Trust to improve organisational performance, the EFQM Model should be adopted.

Commerce↗
PubMed1998

Carotid artery Doppler ultrasonography in retinal macroaneurysms.

It is postulated that retinal arterial macroaneurysms (RAMs) occur at the site of incomplete embolic occlusion of a branch retinal artery. Embolic events of the retinal vessels are related to the state of the carotid artery tree and therefore Doppler ultrasonography of the carotid arteries in these patients is of particular interest. We have examined 13 patients with retinal artery macroaneurysms with carotid artery Doppler ultrasonography (CADU). Eight of these patients (61.5%) exhibited atheromatous plaques on the same side as the RAM with a moderate degree of arterial narrowing. Although our group of patients did not show advanced carotid artery disease, alterations of the arterial wall found at the level of the carotid artery were higher than expected in a similar hypertensive population. To our knowledge this is the first study of the carotid arterial tree in these patients. Our results support the theory that RAMs may be of embolic origin. Furthermore they demonstrate that CADU is a useful investigation in patients with RAMs.

Aged↗
PubMed1997

Thymic regression and apoptosis in the rat after treatment with the Leydig cell cytotoxin ethylene dimethanesulphonate (EDS).

Ethylene dimethanesulphonate (EDS) is an alkylating agent which is widely assumed to specifically kill Leydig cells leaving other biological systems intact. However, after EDS treatment of the male rat the thymus reversibly involutes and the gonadal regional lymph nodes are activated. In the present experiments we have demonstrated that EDS has a direct action upon the thymus both in vivo and in vitro. EDS treatment of the intact and castrated male rat and the intact female rat caused regression of the thymus by up to 50% 3 days later. Total cellularity decreased while the proliferative index increased suggesting a compensatory mechanism. Thymocytes were exposed to EDS in vitro and the response compared to the glucocorticoid methylprednisolone (P), a well characterised thymic apoptotic stimulant. EDS and P increased apoptosis in the thymocyte as characterised by the appearance of cells containing nuclei with apoptotic morphology and with DNA fragmentation visualised by a characteristic ladder after agarose gel electrophoresis. The effects of both EDS and P were time and dose dependent but, in contrast to the effects in Leydig cells, P was the most effective apoptotic stimulus (for instance 100%-P compared to 30%-EDS or 7% control/DMSO after 24 h incubation). The immunological responses of the gonadal lymph nodes were not associated with testicular regression as it was seen in the castrated rat but may be related to a direct action upon the epididymis. In conclusion, tissue specificity of the Leydig cell cytotoxin needs to be extended to the thymus and epididymis. The mode of cell death in Leydig cells and thymocytes after both glucocorticoids and EDS is apoptosis which suggests that they possess some common mechanism(s) which is responsible for the toxicity of these diverse compounds.

Animals↗
PubMed1997

Technical and audiological factors in the implementation and use of digital signal processing hearing aids.

Fully digital hearing aids, to be worn behind or within the ear, are coming on to the market. The new possibilities and challenges of such aids are both technological and audiological in character. This paper describes some of the challenges, and one manufacturer's approach to them. The signal processing structure in one current digital hearing aid is presented, and justified in audiological terms, as a background to discussions of (i) the relative urgency of further advances in technology and audiological knowledge, and (ii) the challenges to the practice of hearing aid dispensing. It is concluded that further advances in rehabilitative audiology are more pressing than further major technological progress, and that the potential client benefits of the new generation of digital hearing aids will only be realized if the challenges they present to software design and dispensing practice are recognized and met.

Correction of Hearing Impairment↗
PubMed1996

Randomized trial of blunt-tipped versus cutting needles to reduce glove puncture during mass closure of the abdomen.

Eighty-five consecutive patients were randomized to undergo mass closure of the abdomen with no. 1 polydioxanone mounted on either a blunt-tipped (n = 46) or cutting (n = 39) needle. Gloves were changed before closure and tested for perforation afterwards using standard air or water techniques. Fourteen pairs of gloves were punctured when using a cutting needle, and three pairs when a blunt-tipped needle was used. The majority of punctures were to the non-dominant glove. The surgeon was aware of the puncture in eight of the 14 instances involving a sharp needle and in one of the three involving a blunt-tipped needle. Blunt-tipped needles, while not eliminating the risk, significantly reduced the incidence of surgical glove puncture (P < 0.001, Fisher's exact test). The use of cutting needles for abdominal closure should be abandoned.

Abdomen↗
PubMed1996

Comparison of two conservative methods of treating an isolated fracture of the lateral malleolus.

We compared two conservative methods of treating Weber B1 (Lauge-Hansen supination-eversion 2) isolated fractures of the lateral malleolus in 65 patients. Treatment by immediate weight-bearing and mobilisation resulted in earlier rehabilitation than immobilisation for four weeks in a plaster cast. There was no significant difference in the amount of pain experienced or in the requirement for analgesics and early mobilisation was not associated with any complications. We therefore advocate early mobilisation for these stable ankle fractures.

Adult↗
PubMed1993

The management of post-keratoplasty astigmatism by post-operative adjustment of a single continuous suture.

Penetrating keratoplasty was performed in 39 consecutive patients. A 16 bite 10-0 nylon continuous suture was used. Post-operatively, the suture was adjusted to reduce astigmatism, as determined by refraction, keratoscopy and keratometry. Suture adjustment was performed if astigmatism was over 4 dioptres (D). The suture was tightened in the flatter meridian and loosened in the steeper meridian. Twenty-one patients had suture adjustment performed. Prior to adjustment, mean (+/- standard deviation) astigmatism measured 6.33 +/- 1.38 D. Following adjustment, mean astigmatism was significantly reduced to 2.69 +/- 1.14 D (p < 0.0001). The average final astigmatism for the entire group was 2.66 +/- 1.12 D. The use of a continuous adjustable suture in penetrating keratoplasty significantly reduced the post-operative astigmatism in a group of patients undergoing penetrating keratoplasty.

Adolescent↗
PubMed1993

Comparison of the Keeler Pulsair 2000 non-contact tonometer with Goldmann applanation.

The Pulsair 2000 non-contact tonometer (Keeler Ltd, UK) is compared with the Goldmann applanation tonometer. Data from 80 eyes were acquired by four experienced observers. A linear regression analysis showed the relationship between the instruments to be: Pulsair = 0.66 + 0.95 Goldmann. Individual components of variation were analysed by analysis of variance which indicated a significant variation in the slope of the regression equation due to observers (p = 0.02) but not to the order in which topical anaesthesia was administered. Differences between two Pulsair instruments were of marginal significance (p = 0.07). The intercept of the regression equation was unaffected by any of the components of variation. Seventy-nine per cent of averaged intraocular pressure measurements obtained with the Pulsair 2000 fell on or within +/- 3 mmHg of those measured with the Goldmann tonometer. It is concluded that the Pulsair 2000 can provide clinically useful measurements of intraocular pressure.

Adolescent↗
PubMed1993

Iris prolapse; who? When? Why?

A 12-month period was reviewed to identify the incidence of iris prolapse following cataract surgery, and any predisposing factors. Of 1408 routine manual extracapsular cataract extractions, 29 eyes (2.06%) sustained an iris prolapse. Iris prolapse was commoner in Asian patients and when less experienced surgeons were operating. Twenty-five per cent of cases occurred in patients with obstructive airways disease or post-operative cough. Thirty-four per cent of iris prolapses were identified on the first post-operative day and 86% within 2 weeks. Prolapse probably occurs because of raised intraocular pressure in association with poor wound construction or closure. More emphasis should be given to wound construction and closure during surgical training, with extra diligence when operating on patients likely to cough postoperatively. Clinicians must ensure non-English speaking patients understand about ocular aftercare following cataract surgery.

Cataract Extraction↗
PubMed1990

Ophthalmic complications of amniocentesis.

Reports of ocular damage from amniocentesis needles are rare. We report four cases of ocular perforation in which an amniocentesis needle may have been the cause and a proven case of central nervous system perforation during amniocentesis which resulted in hemianopia and gaze palsy. Ocular damage during amniocentesis may be commoner than the paucity of reports would suggest, and should be considered in all cases of congenital ocular conditions.

Amniocentesis↗
PubMed1989

Intercapsular versus extracapsular cataract extraction.

Forty-five eyes that have undergone routine extracapsular cataract extraction with insertion of a posterior chamber intraocular lens were compared with a similar group of eyes that had undergone intercapsular extraction. Capsular fixation was more predictable following intercapsular (78%) than it was following extracapsular extraction (22%). Gonioscopy revealed prominence of the lens haptic in 22% of the intercapsular group, with peripheral anterior synechiae (PAS) in 18%; haptics were prominent in 78% of the extracapsular group, with synechiae in 55%. Lens eccentricity of 2 mm or more was seen in 2 patients (4%) following intercapsular and in 10 (22%) following extracapsular extraction. Pupil irregularities were noted in three of the intercapsular group (7%) and in eight of the extracapsular group, (13%) with peripheral iris tucking alone in three. These data strongly support the view that intercapsular is superior to extracapsular cataract surgery in terms of facilitating capsular fixation of posterior chamber intraocular lenses.

Aged↗