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J C H Miles G M Kendall Z-F Ibrahimi C B Howarth 《Journal of radiological protection》2004,24(2):165-171
Etched track detectors are widely used for the detection of radon and its decay products. They have many desirable attributes: they are small, cheap, simple, non-toxic and non-hazardous. Etched track detectors provide adequate accuracy for most radiological protection purposes provided stringent quality assurance is maintained. The UK validation scheme provides an important component of QA but continuous monitoring of conditions and results is also needed. If these conditions are observed, these detectors provide an entirely adequate tool for large-scale use in assessing levels of radon in houses. Accurate estimates of long-term average radon levels require a measurement over several months because of the short-term fluctuations in radon concentrations. 相似文献
4.
Douglas M. Howarth Martin T. Epstein Paul A. Thomas Leonard W. Allen Rachel Akerman Linda Lan 《European journal of nuclear medicine and molecular imaging》1997,24(12):1465-1469
The efficacy of fractionated out-patient radioiodine therapy in 38 patients with compressive symptoms due to long-standing
large multinodular goitres was assessed. The diagnosis was established by clinical assessment in addition to technetium-99m
pertechnetate thyroid scan or computed tomography scan of the thyroid and mediastinum. Oral iodine-131 therapy was administered
as a 2.22 GBq (60 mCi) cumulative dose over 4 months (555 MBq per month). All patients were monitored with serum thyroid-stimulating
hormone and free thyroxine (± free tri-iodothyronine) assays before the treatment and after each dose fraction. Clinical and
biochemical follow-up was performed on all patients and ranged from 6 to 45 months after therapy. The patients consisted of
35 female and three male patients with a median age of 59 years (range 37–87 years). Prior to treatment 20 patients were biochemically
hyperthyroid and 18 were euthyroid. Overall, 71% of patients reported a subjective improvement in compressive symptoms and
29% reported no change. Clinically assessed reduction in goitre size occurred in 92% of patients while there was no change
in 8%. At 3 months of follow-up, 31% of patients had become hypothyroid and at 18 months 66% were hypothyroid. Seven hyperthyroid
patients (35%) became euthyroid and 13 hyperthyroid patients (65%) became hypothyroid. Three patients who became hypothyroid
experienced neck soreness (transient in one patient, persistent in two patients). There were no differences in outcome between
patients who were hyperthyroid and those who were euthyroid prior to treatment. Fractionated out-patient radioiodine therapy
showed excellent short- and medium-term safety, was very well tolerated and offered a satisfactory alternative treatment to
surgery.
Received 23 May and in revised form 11 August 1997 相似文献
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The processing of antigens delivered as DNA vaccines 总被引:2,自引:0,他引:2
Summary: The ability of DNA vaccines to provide effective immunological protection against infection and tumors depends on their ability to generate good CD4+ and CD8+ T‐cell responses. Priming of these responses is a property of dendritic cells (DCs), and so the efficacy of DNA‐encoded vaccines is likely to depend on the way in which the antigens they encode are processed by DCs. This processing could either be via the synthesis of the vaccine‐encoded antigen by the DCs themselves or via its uptake by DCs following its synthesis in bystander cells that are unable to prime T cells. These different sources of antigen are likely to engage different antigen‐processing pathways, which are the subject of this review. Understanding how to access different processing pathways in DCs may ultimately aid the rational development of plasmid‐based vaccines to pathogens and to cancer. 相似文献
7.
Effect of inhaled frusemide on responses of airways to bradykinin and adenosine 5'-monophosphate in asthma. 总被引:3,自引:3,他引:0 下载免费PDF全文
BACKGROUND--Inhaled frusemide exerts a protective effect against bronchoconstriction induced by several indirect stimuli in asthma. This effect could be caused by interference with neural pathways. The effect of inhaled frusemide on bronchoconstriction induced by inhaled bradykinin, which is thought to cause bronchoconstriction via neural mechanisms, was studied and compared with the effects of adenosine 5'-monophosphate (AMP) which probably produces its airway effects by augmenting mast cell mediator release and interfering with neural pathways. METHODS--Patients first underwent AMP and bradykinin challenges. They were then studied in a randomised, placebo controlled, double blind fashion. Ten atopic asthmatic subjects, studied on four days, were pretreated with inhaled frusemide (40 mg) or placebo for 10 minutes, five minutes before challenge with increasing concentrations of nebulised AMP or bradykinin. RESULTS--On the open visit days the provocative concentrations required to reduce forced expiratory volume in one second (FEV1) by 20% from baseline (PC20) for AMP and bradykinin were 16.23 (1.42-67.16) and 2.75 (0.81-6.6) mg/ml. There was a significant correlation between baseline AMP and bradykinin PC20 values. For AMP the geometric mean PC20 values following pretreatment with inhaled frusemide and matched placebo were 80.97 (9.97- > 400.0) and 14.86 (2.6-104.6) mg/ml respectively (95% CI 0.49 to 0.98). For bradykinin the geometric mean PC20 values following pretreatment with inhaled frusemide and matched placebo were 13.22 (2.53- > 16.0) and 2.52 (0.45-5.61) mg/ml respectively (95% CI 0.43 to 1.01). Frusemide afforded 5.45 and 5.24 fold protection against AMP and bradykinin-induced bronchoconstriction respectively. Furthermore, there was a significant correlation between protection afforded to the airways against AMP and bradykinin. CONCLUSIONS--These data suggest that inhaled frusemide affords protection against bradykinin-induced bronchoconstriction which is comparable to that against AMP, supporting a common mechanism of action for frusemide. 相似文献
8.
Mahmoud I. Abdel-Aziz Paul Brinkman Susanne J.H. Vijverberg Anne H. Neerincx John H. Riley Stewart Bates Simone Hashimoto Nazanin Zounemat Kermani Kian Fan Chung Ratko Djukanovic Sven-Erik Dahlén Ian M. Adcock Peter H. Howarth Peter J. Sterk Aletta D. Kraneveld Anke H. Maitland-van der Zee 《The Journal of allergy and clinical immunology》2021,147(1):123-134
9.
Consensus statement on the treatment of allergic rhinitis. European Academy of Allergology and Clinical Immunology 总被引:14,自引:0,他引:14
10.
F. C. Howarth Allan J. Levi Jules C. Hancox 《Pflügers Archiv : European journal of physiology》1996,431(5):713-722
The delayed rectifier potassium current (I
K) is known to be important in action potential repolarisation and may contribute to the diastolic pacemaker depolarisation
in pacemaker cells from the heart. In this study, using whole-cell patch clamp, we investigated the characteristics of I
K in morphologically normal cells from the atrioventricular node (AVN) and ventricle of the rabbit heart. Cells were held at
−40 mV and 5 μM external nifedipine was used to block L-type calcium current (I
Ca,L). Significant I
K was observed with pulses to potentials more positive than −30 mV. The steady-state activation curve in both cell types showed
maximal activation at between + 10 and + 20 mV. Half-maximal activation of I
K occurred at −4.9 and −4.1 mV with slope factors of 8.3 and 12.4 mV in ventricular and AVN cells, respectively. Using pulses
of increasing duration, significant I
K tails after repolarisation from + 40 mV were observed with pulses of 20 ms and increased with pulses up to 100–120 ms in
both cell types. Pulses of longer duration did not activate further I
K and this suggested that only the rapid component of I
K, called I
Kr, was present in either cell type. Moreover, I
K tails after pulses to all potentials were blocked completely by E-4031, a selective blocker of I
Kr. The reversal potential of I
K varied with the concentration of external K. Superfusion of AVN cells with medium containing 4, 15 and 40 mM [K+]o resulted in reversal potentials of −81, −56 and −32 mV, respectively, which are close to values predicted if the I
K channel were highly selective for K. The time constants for deactivation of I
K in ventricle and AVN on return to −40 mV after a 500-ms activating pulse to + 60 mV were 480 ms and 230 ms, respectively.
The faster deactivation of I
K in AVN cells was a distinguishing feature and suggests that there may be differences in the I
Kr channel protein between ventricular and AVN cells.
Received: 24 July 1995 /Received after revision: 20 October 1995 /Accepted: 23 October 1995 相似文献