Evaluation of the beta-Neocept test for early pregnancy.

We tested the validity of the beta-Neocept test for early pregnancy against that of the plasma human chorionic gonadotropin beta-subunit radioimmunoassay (beta-HCG RIA). The beta-Neocept test had a sensitivity of 88%, a specificity of 93%, a positive predictive value of 95%, a negative predictive value of 84% and an accuracy of 90%. In view of these performance characteristics, its low cost and its ease of use, the beta-Neocept test could be used as the initial pregnancy test when there is a high probability of pregnancy, as there was in this study population, which consisted of 111 women attending endocrine infertility clinics. The more expensive beta-HCG RIA could be reserved for special indications and for patients in whom the results of the urinary hemagglutination inhibition tests are inconsistent with the clinical signs and symptoms.     

Abnormal ventilation scans in middle-aged smokers. Comparison with tests of overall lung function

We have assessed the uniformity of regional ventilation during tidal breathing using continuous inhalation of krypton-81m in 43 male, lifelong nonsmokers and 46 male, current cigarette smokers (mean daily consumption 24.1 cigarettes/day) between 44 and 61 yr of age and with mild or no respiratory symptoms. All subjects had normal chest radiographs. The results of the ventilation scans were compared with tests of overall lung function (spirometry, maximal expiratory flow-volume curves, and single-breath N2 test). Diffuse abnormalities of the ventilation scan were found in 19 (41%) of the 46 smokers but in none of the nonsmokers. Focal abnormalities were found in 7 smokers and 3 nonsmokers. Smokers showed the expected abnormalities in overall lung function (reduced FEV1 and VC, increased single-breath N2 slope, and closing volume), but in individual smokers there was only a weak relation between the severity of abnormality of overall lung function and an abnormal ventilation scan. Abnormal scans could be found when overall lung function was normal and were not invariably found when significant abnormalities in FEV1/VC or N2 slope were present. There was no relation between the presence of chronic expectoration and an abnormal scan. The prognostic significance of an abnormal ventilation scan in such smokers remains to be established.