NORMALIZATION OF THYROID BLOOD FLOW IN Graves''HYPERTHYROIDISM FOLLOWING RADIOACTIVE IODINE THERAPY

In a group of 12 patients with Graves' hyperthyroidism, administration of 514 +/- 43 (mean +/- SD) MBq iodine-131 was associated with a fall of superior thyroid artery (STA) blood flow in two at 6 months and in eight at 11 months. The reduction in time-averaged velocity at 11 months correlated with the reduction in FT4 (r = 0.72, P less than 0.01) and in FT3 (r = 0.64, P less than 0.025) at this time. In four patients who had persistent elevated STA blood flow, two were still hyperthyroid. The diameter of the STA was unchanged at 6 months and only half the patients had reduction of their STA size at 11 months after radioiodine (RAI) therapy. These data indicate that normalization of STA blood flow precedes normalization of STA size in patients treated with RAI. Further work is required to determine whether STA blood flow measurements are of predictive value in treatment outcome.     

Differential diagnosis of ischaemic ulceration of the leg using ultrasound

Whilst most ulcers on the leg can be confidently and easily separated into those due to venous insufficiency and those due to arterial obstruction, some may present problems of differential diagnosis. Further investigation then becomes necessary. In order to avoid arteriography a new, quick, transcutaneous method has been evolved, which is painless, repeatable and can be carried out in an outpatient clinic. This technique uses two ultrasonic fiowmeters. The propagation time of the pulse wave between two measuring sites along the arterial system of the leg and the change in waveform shape between these two sites are measured.     

Continuing Education: A Survey Among General Practitioners

A survey of perceptions of continuing education—content,methods and current provision—was undertaken among allestablished general practitioners in one health region of theUK using a postal questionnaire. Interviews were conducted witha small random sample of respondents and with a larger sampleof non-respondents to the questionnaire. Data from the questionnaireand interviews demonstrated overall a wide diversity of contentand methods of continuing education perceived as appropriate,with duration of experience and involvement in undergraduateteaching or postgraduate training as significant determinants.The findings are used to review, critically, current provisionof continuing education for general practice and to suggestways in which future provision might reflect the range of educationalneed perceived by doctors.     

Domestic allergens in public places II: dog (Can f 1) and cockroach (Bla g 2) allergens in dust and mite, cat, dog and cockroach allergens in the air in public buildings

Background Sensitization and exposure to indoor allergens are the major risk factors for asthma. It is possible that significant exposure to domestic allergens occurs outside the home. Objectives To investigate the levels of Can f 1 and Bla g 2 in the dust from carpeted floors and upholstered seats in public buildings and public transport and the airborne concentrations of Der p 1, Fel d 1, Can f 1 and Bla g 2 in schools and offices. Methods Can f 1 and Bla g 2 were measured in the dust collected by vacuuming a I m² area of carpet, as well as upholstered seats in five schools, six hotels, four cinemas, six pubs, three buses and two trains. Dust was also collected from the bedroom carpet, living room carpet, mattress and sofa in 20 homes with and 20 homes without a dog in the same area. Personal airborne sampling (2 L/min) was conducted for 8 h in offices (n= 16) and classrooms (n= 9). In addition, airborne samples in schools were collected using a high volume pump (60 L/min) for 1 h in three classrooms immediately after the children vacated the school. Can f 1, Bla g 2, Der p 1 and Fel d 1 were assayed using a two–site monoclonal antibody–based ELISA. Results Can f 1 was detected in all dust samples from public places, ranging from 0.2 to 52.5 μg/g, Significantly higher levels were found in upholstered scats (geometric mean – GM 9.4 μg/g) than in carpets (GM 1.5 μg/g; P < 0.001), and levels of Can f 1 > 10 μg/g were found in 40% of upholstered seats in public places. Can f 1 was significantly higher in upholstered seats in public places than in sofas in homes without a dog (GM 1.8 μg/g; P < 0.001). Detectable levels of Bla g 2 were found in all of the schools (GM 2.4 U/g, range 0.8–4.4 U/g). Bla g 2 concentration greater than 2U/g (provisional threshold level representing risk of sensitization) was measured in 65% of the classrooms sampled. Der p 1 and Bla g 2 were below the detection limit in all airborne samples. However, airborne Fel d 1 and Can f 1 were detected in schools and offices, albeit in low concentrations. Conclusions Upholstered seats from public places constitute a reservoir for the accumulation of dog allergen, and a source of exposure to Can f 1 inside public buildings or on public transport. Exposure to cockroach allergens in schools may be important for cockroach sensitized asthmatic children.     

A comparison of the binding constant (Kd) of 125I-labelled 3-(4-iodophenoxy)-1-isopropylamino-propan-2-ol obtained on β-adrenoceptors in guinea-pig myocardial membranes,with its dissociation constants (Kb) obtained on guinea-pig isolated atria and trachea

The dissociation constant of binding (K_D) of ¹²⁵I-labelled 3-(4-iodophenoxy)-1-isopropyl-aminopropan-2-ol (IIP) to guinea-pig myocardial membrane preparations was 2·2 × 10^?8m. In pharmacological experiments with the non-labelled material and 60 min contact time, IIP produced a parallel shift in the orciprenaline concentration-response line on guinea-pig isolated tracheal and atrial preparations. The dissociation constant (Kb ) of IIP was 2·9 × 10^?8m on atria (pA₂ 7·54) and 3·3 × 10^?8m on trachea (pA₂ 7·48). These values indicate that IIP is not a selective β-adrenoceptor blocking drug. In addition, agreement was found between the affinity constant of this antagonist for β-adrenoceptors as determined by a direct binding study and an indirect pharmacological study.