Biomedical subjects
S Shaw
Publications and source records attributed to S Shaw.
Assessing attitudes in dental education.
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Insulin-injection-site reactions associated with type I latex allergy.
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Routine patch testing with frullanolide mix: an European Environmental and Contact Dermatitis Research Group multicentre study.
Contact sensitivity to plants containing 1 or more sesquiterpene lactones (SLs) is difficult to diagnose. The mixture of SLs (SL mix) has been shown to detect only about 60% of sensitized individuals. In order to improve the diagnosis of sensitization to plants containing SLs, we have tested a mixture of frullanolides contained in Frullania dilatata and Frullania tamarisci at 3 different concentrations (0.01%, 0.033% and 0.1% in petrolatum). 8605 consecutive eczema patients in 1 North American and 15 European dermatology departments were tested with this mix, and 0.35% of positive cases to the different concentrations were found. Routine use of this mix permitted detection of only a small percentage of extra cases and did not improve the SL mix score. The frullanolide mix should therefore be restricted to investigations in particular geographical zones and/or in particular occupations.
The British standard series of contact dermatitis allergens: validation in clinical practice and value for clinical governance.
BACKGROUND: All centres use an empirically determined set of 'standard' test allergens for patch testing that contain the commoner environmental sensitizers. Objectives To assess the validity of the British standard series of 12 allergens used in addition to the 23 already in the European standard series. PATIENTS AND METHODS: Results for 3062 consecutive patients patch tested in seven centres across the United Kingdom during the year 2000 were analysed. RESULTS: The additional allergens from the British series and positive rates were: methyl dibromoglutaronitrile 2.4%, carba mix 1.6%, tixocortol pivalate 1.5%, ethylenediamine 1.3%, cetearyl alcohol 0.8%, 2-bromo-2-nitropane-1,3-diol 0.8%, diazolidinyl urea 0.7%, chlorocresol 0.6%, budesonide 0.6%, fusidic acid 0.5%, imidazolidinyl urea 0.5%, and chloroxylenol 0.4%. The allergens with the lowest positive rate in the European standard series were primin at 0.6% and isopropyl-phenyl-para-phenylenediamine at 0.4%. CONCLUSIONS: The 12 allergens in the British series should continue being tested as a standard addition to the European series within the U.K. The collection of data in this manner to allow comparisons between centres shows differences that reflect selection criteria and interpretation of results, and offers a useful tool for audit and clinical governance. Testing fewer than 1 : 2150 population may indicate underprovision of service. Similarly, rates of sensitization for nickel contact allergy above 26% and for fragrance mix above 16% (the upper 95% confidence intervals) should stimulate inquiry into the reasons behind this.
Evidence for the involvement of endothelin-1 but not urotensin-II in chronic lower limb ischaemia in man.
BACKGROUND: endogenous vasoconstrictor peptides may play a role in the pathophysiology of critical limb ischaemia (CLI). This study investigated endothelin-1 (ET-1) and urotensin-II (U-II) mRNA expression, peptide distribution and ET receptor subtype binding in chronically ischaemic muscle. METHODS: open muscle biopsies were taken from patients undergoing amputations for CLI and from patients undergoing coronary artery bypass surgery (controls). ET-1 and U-II mRNA expression in muscle biopsies was studied using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). ET-1 and U-II immunohistochemistry was performed on muscle sections and ET receptor binding studied using in vitro autoradiography. RESULTS: ET-1 mRNA expression was significantly increased in CLI compared to controls (p<0.05) whilst no significant change in U-II expression occurred. ET-1 immunoreactivity was also increased in CLI with no difference in U-II immunostaining observed. ET(B) receptor binding was significantly increased in CLI (median 4, range 1-8 vs 2, range 1-3, dpm x 10(3)/mm(2), p=0.01, Mann-Whitney test) whilst ET(A) receptor binding was not significantly raised. Binding was associated with microvessels and macrophages. CONCLUSIONS: in CLI, the ET-1 pathway is upregulated but U-II is unaffected. ET-1 may vasoconstrict microvessels and mediate inflammation in chronically ischaemic muscle. ET-1 binding to ET(B) receptors in particular may play an important role in the pathophysiology of CLI underscoring the therapeutic potential of ET(B) receptor antagonists in the management of CLI.
Presbyopic phacovitrectomy.
AIM: To review the results and complications of combined phacoemulsification and vitrectomy in presbyopic patients. METHODS: Retrospective review of 90 consecutive presbyopic patients who underwent phacoemulsification and vitrectomy for primary rhegmatogenous retinal detachment (RRD) (21), redo-RRD (seven), stages 2 and 3 full thickness macular holes (FTMH) (38), stage 4 FTMH (six), idiopathic epiretinal membrane (ERM) (11), proliferative diabetic retinopathy (PDR) (three) and vitreous haemorrhage secondary to branch retinal vein occlusion (BVO) (four). RESULTS: Lens opacity was absent or mild in 84.5% of patients. Reattachment rates for primary RRD and redo-RRD after one procedure were 90.5% and 71.4% and final reattachment rates were 95.2% and 100%, respectively. Macular hole closure rate was 89.5% for stage 2 and 3 FTMH and 83.3% for stage 4 FTMH. There was significant improvement in the median logMAR visual acuity from 1.00 preoperatively to 0.48 postoperatively for the whole cohort (p<0.001, Wilcoxon test). Postoperative complications included fibrinous uveitis (13.3%), iris bombe (2.2%), IOL/iris capture secondary to gas overfill (1.1%), and posterior capsule opacification (51.1%). CONCLUSION: Combined phacoemulsification and vitrectomy is a safe and desirable option in the management of phakic, presbyopic patients with vitreoretinal pathologies that warrant vitreous surgery, even in the absence of significant lens opacity.
Diagnosis and eradication of Helicobacter pylori in patients with duodenal ulceration in the community.
OBJECTIVE: To determine the value of Helicobacter pylori (Hp) serology in diagnosis of active Hp infection in patients with documented duodenal ulcer (DU) and to directly compare the efficacy and side-effects profiles of metronidazole or tinidazole in a triple therapy regimen to eradicate active Hp infection. DESIGN OF STUDY: Prospective, single-blinded, randomised trial. METHODS: One hundred patients from General Practice with documented DU and Hp seropositivity had a C14 Urea Breath Test (UBT). Those who tested positive were randomised to receive one-week, twice daily omeprazole 20 mgs and clarithromycin 250 mgs in combination with metronidazole 400 mgs (OCM) or tinidazole 500 mgs (OCT). Eradication was confirmed by a repeat UBT. RESULTS: Eighty five sero-positive patients had a positive pre-treatment UBT. On intention to treat basis, OCT (100%) had a significantly better eradication rate than OCM (87.8%), p = 0.023. There was no difference in side effects. CONCLUSION: (1) Positive Hp serology in patients with DU does not always mean active infection and (2) for patients in the community with active Hp and DU disease OCT is significantly better than OCM for eradicating Hp.
Angiotensin-converting enzyme inhibitor therapy prevents upregulation of endothelin-converting enzyme-1 in failing human myocardium.
In this study, we investigated the role of the renin-angiotensin system in expression of the endothelin system in atrial myocardium of patients with congestive heart failure. Atrial myocardium of control patients without angiotensin-converting enzyme (ACE) inhibitor therapy and heart failure patients without or with ACE inhibitor therapy undergoing aorto-coronary bypass surgery was studied. Endothelin-converting enzyme-1 (ECE-1) expression and endothelin-1 peptide level was upregulated in myocardium of heart failure patients without ACE inhibition. ACE inhibitor therapy prevented upregulation of ECE-1 and endothelin-1 in failing myocardium. Prepro-endothelin-1 and endothelin receptor A expression were not affected by heart failure. Endothelin receptor B was downregulated in heart failure patients. Our data demonstrate an upregulation of ECE-1 mRNA expression in failing human myocardium. Inhibition of the renin-angiotensin system by ACE inhibitor treatment prevents upregulation of ECE-1, suggesting that angiotensin II regulates ECE-1 expression in vivo.
Use of ultramolecular potencies of allergen to treat asthmatic people allergic to house dust mite: double blind randomised controlled clinical trial.
OBJECTIVE: To evaluate the efficacy of homoeopathic immunotherapy on lung function and respiratory symptoms in asthmatic people allergic to house dust mite. DESIGN: Double blind randomised controlled trial. SETTING: 38 general practices in Hampshire and Dorset. PARTICIPANTS: 242 people with asthma and positive results to skin prick test for house dust mite; 202 completed clinic based assessments, and 186 completed diary based assessments. INTERVENTION: After a four week baseline assessment, participants were randomised to receive oral homoeopathic immunotherapy or placebo and then assessed over 16 weeks with three clinic visits and diary assessments every other week. OUTCOME MEASURE: Clinic based assessments: forced expiratory volume in one second (FEV(1)), quality of life, and mood. DIARY BASED ASSESSMENTS: morning and evening peak expiratory flow, visual analogue scale of severity of asthma, quality of life, and daily mood. RESULTS: There was no difference in most outcomes between placebo and homoeopathic immunotherapy. There was a different pattern of change over the trial for three of the diary assessments: morning peak expiratory flow (P=0.025), visual analogue scale (P=0.017), and mood (P=0.035). At week three there was significant deterioration for visual analogue scale (P=0.047) and mood (P=0.013) in the homoeopathic immunotherapy group compared with the placebo group. Any improvement in participants' asthma was independent of belief in complementary medicine. CONCLUSION: Homoeopathic immunotherapy is not effective in the treatment of patients with asthma. The different patterns of change between homoeopathic immunotherapy and placebo over the course of the study are unexplained.
Monitoring levels of preservative sensitivity in Europe. A 10-year overview (1991-2000).
A 10-year multicentre analysis of the frequency of sensitivity to common preservatives collected in 16 centres in 11 countries has shown stable but persisting high levels of sensitivity to formaldehyde and 5-chloro-2-methyl-4-isothiazolin-3-one + 2-methyl-4-isothiazolin-3-one (MCI/MI). It has also revealed a significant increase in the level of reactivity to methyldibromoglutaronitrile (MDBGN) from 0.7% in 1991 to 3.5% in 2000. The current high level of sensitivity to MDBGN requires an urgent safety re-evaluation and risk assessment update along with consideration of immediate lowering of use concentrations, especially in leave-on products.
Allergic contact otitis externa due to iodoform in BIPP cavity dressings.
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Type-IV hypersensitivity to betamethasone valerate and clobetasol propionate: results of a multicentre study.
BACKGROUND: Most studies investigating steroid allergy have been performed with tixocortol pivalate, hydrocortisone butyrate and budesonide. Betnovate and Dermovate are widely prescribed in the U.K. but little is known about the frequency of sensitization to them. OBJECTIVES: To determine the optimum method to detect contact allergy to betamethasone valerate (BV) and clobetasol propionate (CP). METHODS: Seven centres tested consecutive patients attending for investigation of suspected allergic contact dermatitis to these steroids at a range of concentrations in different vehicles. RESULTS: Of 1562 patients tested, 16 (1%) reacted to either BV or CP. Ten patients (0.7%) reacted to BV and 13 (0.8%) to CP. Two patients of a further centre were included in analysis of dilutions and vehicles. Sixteen of a total of 25 reactions (64%) were identified with a 1% dilution in ethanol. CONCLUSIONS: Consideration should be given to adding BV and CP to a standard allergy series, given that both are frequently used in the treatment of eczema and that most patients sensitized to them are not identified with currently used markers of steroid allergy. If patch tests to BV and CP are initially negative, but an allergy is suspected, the patient should be further investigated. Further studies are required to identify the ideal patch test material.
Potential role of endothelin 1 in ischaemia-induced angiogenesis in critical leg ischaemia.
BACKGROUND: Ischaemia-induced angiogenesis occurs in critical leg ischaemia (CLI) and endothelin (ET) 1 may be involved in this process. The aim of this study was to quantify microvessels and study ET receptor expression and distribution in critically ischaemic leg muscle. METHODS: Leg muscle biopsies were taken from 12 patients with CLI and 12 patients with no leg ischaemia. Microvessels were identified immunohistochemically on muscle sections, and the number of immunopositive cells was quantified. ETA and ETB receptor messenger RNA (mRNA) expression was studied using real-time quantitative reverse transcriptase-polymerase chain reaction, and receptor binding was localized and assessed by in vitro autoradiography. RESULTS: The number of microvessels in CLI muscle biopsies was 2.6 times higher than that in controls (P < 0.01). ETB receptor mRNA expression and binding were significantly increased in CLI tissue (P < 0.05), while ETA receptor levels were not significantly raised. High-resolution autoradiography showed that ET receptor binding was associated with microvessels. CONCLUSION: Angiogenesis occurs in CLI and raised ETB receptors within the muscle were associated with microvessels, suggesting that ET-1 may mediate angiogenesis via these receptors in critically ischaemic muscle.
Retinal detachment surgery in district general hospitals: an audit of changing practice.
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Equine granulocytic ehrlichiosis in the UK.
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Cutting edge: integration of human T lymphocyte cytoskeleton by the cytolinker plectin.
Chemokine-induced polarization of lymphocytes involves the rapid collapse of vimentin intermediate filaments (IFs) into an aggregate within the uropod. Little is known about the interactions of lymphocyte vimentin with other cytoskeletal elements. We demonstrate that human peripheral blood T lymphocytes express plectin, an IF-binding, cytoskeletal cross-linking protein. Plectin associates with a complex of structural proteins including vimentin, actin, fodrin, moesin, and lamin B in resting peripheral blood T lymphocytes. During chemokine-induced polarization, plectin redistributes to the uropod associated with vimentin and fodrin; their spatial distribution indicates that this vimentin-plectin-fodrin complex provides a continuous linkage from the nucleus (lamin B) to the cortical cytoskeleton. Overexpression of the plectin IF-binding domain in the T cell line Jurkat induces the perinuclear aggregation of vimentin IFs. Plectin is therefore likely to serve as an important organizer of the lymphocyte cytoskeleton and may regulate changes of lymphocyte cytoarchitecture during polarization and extravasation.