Macroglobulinemia. III. The effect of mercaptoethanol on the antigenic structure of macroglobulins

Each of several antigen-antibody systems studied has been found to affect the coagulation mechanism in the rabbit, causing a marked shortening of the coagulation time in vitro of samples of whole blood maintained in siliconized glassware. Addition of specific antigen to the blood of actively immunized animals or addition of antigen-antibody mixtures to the blood of normal animals produced the effect. The coagulation time of plasma was not affected, indicating that the phenomenon may be mediated by an effect on platelets. This effect of antigen-antibody interaction may be involved in the production of tissue damage in vivo.     

Spatial Distribution of QT Intervals: An Alternative Approach to QT Dispersion

QT dispersion (QTd) describes the heterogeneity of ventricular repolarization on the basis of the temporal range of QT intervals as measured in the 12-lead ECG. We examined the spatial distribution of QTd using multichannel magnetocardiograms (MCGs), which noninvasivety register changes in magnetic field strength at 37 sites over the heart. As in ECG, the MCG signal in each channel may be used to measure QT interval. By calculating QT deviation from QT_min at each site, one can reconstruct the spatial distribution of QTd. Analysis of spatial QTd in ten healthy subjects and ten patients after acute myocardial infarction (MI) showed clear differences in spatial distribution. The healthy subjects generally displayed shorter QT intervals along a line corresponding to the approximate position of the septum with longer intervals in plateaus in the upper right and lower left. Spatial QTd of the post-MI patients deviated from this pattern, often displaying a sharp rise in QT duration over specific areas, which could be related to functional and morphological disturbances. The quantification of local irregularities as well as the overall pattern on the basis of a smoothness index allowed better discrimination between healthy subjects and post- MI patients than QTd. Distribution patterns of QTd which reflect local repolarization alterations may thus represent a more differentiated marker for pathology and risk.     

Multidimensionality of psychological recovery from anaesthesia

Six recovery tests, choice reaction time (CRT), CRT doubletask, finger tapping test (FTT), critical flicker fusion frequency (CFF), Maddox wing, and p-deletion test, which cover basic cognitive, motor and perceptive functions as well as concentration, were analysed and compared with each other. Correlation between these tests after recovery from standardised general anaesthesia was calculated in 22 patients. Moderate to high correlation was found between CRT and CRT doubletask (r = 0.62 to r = 0.73), when parameters of six different tests were compared. Finger tapping correlated moderately with the movement time of both the CRT and the CRT doubletask (r = 0.46 and r = 0.47 respectively). We concluded that the CRT test, which measures initiation and movement time, might replace the CRT doubletask and the FTT. The CFF correlated moderately with the initiation time of the CRT doubletask, but because a slightly different function seems to be involved, further research is needed. Maddox wing and the p-deletion test correlated with no other test. Results indicated that recovery is differentiated in at least four distinct psychomotor functions, which should be tested by CRT (to measure initiation and movement time), Maddox wing and p-deletion.     

Silverfish protein in house dust in relation to mite and total arthropod level

Two assays have been developed to measure arthropod levels in house dust. The first assay measures silverfish antigens. The second assay measures invertebrate tropo-myosin and gives a global assessment of the level of atthropod-derived material. These assays and a Der p 1 and Der p 2 assay were used to analyse 53 dust samples. In most dust samples the ratio of tropomyosin/Der p 2 was higher than in mite body extract, indicating that the assay measures other arthropods besides mites. Silverfish antigen was detectable in most of the dust samples. In many homes in which the inhabitants were unaware of the presence of silverfish, silverfish antigen was detectable. Therefore for information on exposure an immunochemical analysis is superior to a questionnaire.