A simple quantitative estimate of the function of radiolabelled platelets

The function ex vivo of autologous platelets, labelled with 111In, was evaluated at various times following injection by comparing the retention on foreign surfaces of radioactivity with the retention of total platelets (represented almost entirely by unlabelled and therefore unmanipulated platelets) after the application of fresh un-anticoagulated whole blood to (a) filter paper and (b) glass bead columns. Relative retentions were similar for the two materials, with labelled platelet retention being about 80% that of native platelet retention. Prior to injection, when labelled platelets were returned to an excess of freshly drawn whole blood, retention of radioactivity was greater than that of native platelets with a ratio significantly greater than that seen with labelled platelets tested ex vivo. Filter paper retention provides a simple technique which may be useful for the evaluation of labelled platelet function as a function of platelet age and also, with further standardisation, as an inexpensive rapid test of unlabelled platelet function.

Psychological management of anxiety and pain during dental treatment

Sensation information, perceived control and distraction were compared with routine dentistry in a study of the effect of psychological context on pain and anxiety during dental treatment. The results indicated that the provision of sensation information was the most effective treatment.

Fear of dentistry

Patients attending the primary care department of a London dental hospital and a suburban general practice were interviewed to explore their experience of and reasons for anxiety about dental treatment. Results showed that anxiety was at a high level, particularly concerning certain treatment procedures. The most common reason given for fear was anticipated pain, and this was borne out by a comparison between anxiety and expected pain for a number of dental procedures. The possibility of mitigating dental fear by procedures which focus on minimizing pain expectations and pain experience is discussed.

Binge eating: a theoretical review

An eating pattern consisting of gorging, alternating with dieting and purging is identified as a clinical problem in patients of normal weight, in the obese, and in patients with anorexia nervosa. The clinical reports have used a variety of names for this problem, and this has obscured the similarity between the various descriptions. Another perspective on the problem is offered by the experimental research on dietary restraint and counter-regulation. Counter-regulation, found in subjects from all weight groups who are restricting their food intake, is construed as a laboratory version of an eating binge. The clinical and experimental reports are combined to provide suggestions for the aetiology and treatment of the problem of binge eating.

Cell volume studies in B-cell leukaemia

Leucocyte volume histograms were obtained in 12 cases of B-chronic lymphocytic leukaemia (B-CLL), two cases of B-prolymphocytic leukaemia (B-PLL) and two cases of hairy-cell leukaemia (HCL) by means of a Coulter model ZBl linked to a channelyser. Visual examination of the histograms showed differences between the cases which were confirmed by measurement of the modal volume (MV) and the sigma value (SD of log-volume). The MV of the cells in B-CLL ranged from 153.8 to 244.2 fl (mean 198.24 fl) and was lower than the MV in the cases of HCL (427.5 and 465.6 fl). One case of B-PLL had cells with an MV within the B-CLL range while in the other the MV was greater (317.9 fl). The histogram in one of two cases of B-CLL in 'prolymphocytoid' transformation showed a relatively high sigma value, thus suggesting heterogeneity in cell size. The volume histogram is a simple method of sizing the predominant cell in the peripheral blood in lympho-proliferative disorders and permits an objective comparison between cell sizes in different diseases.

Glucose-6-phosphate dehydrogenase deficiency and homozygous sickle cell disease in Jamaica

The relationship between D-glucose-6-phosphate: NADP oxido-reductase (E.C.1.1.1.49; glucose-6-phosphate dehydrogenase; G6PD) deficiency and homozygous sickle cell (SS) disease was examined in 120 patients. The proportions of hemizygotes (22.6%) was slightly more than that observed, and the combined proportions of heterozygotes and homozygotes (28.3%) were slightly less than would be expected, in the general population, but the differences were not significant. However, the proportion of patients of abnormal G6PD status in the 10-19 years age group was 41.7%, significantly more than that found in the 20-29 years age group (0.02 less than P less than 0.05), or expected in the general population (P=0.05). Possible reasons for this are discussed. Difference in G6PD status did not affect the total haemoglobin concentration, reticulocyte count, unconjugated serum bilirubin or Hb F concentration, irreversibly sickled cell counts or plasma haemoglobin concentration, and there was no demonstrable correlation between clinical severity or leg ulceration and abnormal G6PD status.

Beta-thalassaemia of clinical significance in adult Jamaican Negroes

Over a 9-year period, three adult Negro patients with beta-thalassaemia of clinical significance were recognized out of approximately 185 000 new adult patients attending the University Hospital. These patients, aged 15-58 years, have clinical and haematological characteristics within the spectrum of beta-thalassaemia intermedia; which in this paper refers to phenotypes resulting from defects in beta-chain synthesis clinically intermediate between classical Cooley's anaemia and beta-thalassaemia trait, genetic classification being dependent on family study. Family studies established the presence of two beta-thalassaemia genes conclusively in one case (proposita, family A); presumptively in another (propositus, family C); while in the remaining subject (proposita, family B), who has two similarly affected siblings, homozygosity is suspected, but not proven by family study. In simultaneous 59Fe and 51 Cr studies, estimates of effective erythropoiesis are in reasonable agreement with measurements of red cell destruction.