The application of rigid internal fixation to the treatment of non-union and delayed union using the AO technique

This paper describes our experience over a period of 10 years (1966-76) with fractures showing non-union and delayed union. All were treated by the AO technique. The source of our patients, the management of their fractures and the results are described. From this experience we have drawn conclusions on which future policy will be based.     

Cholesterol-dependent human complement activation resulting in damage to liposomal model membranes

Human (but not guinea pig) complement-mediated damage. It was concluded that human complement was activated spontaneously by liposomes containing a high concentration (71 mol %) of cholesterol. This occurred in the absence of any recognizable antigen or antibody, and did not occur at a low concentration (43 mol %) of cholesterol. Activation of complement resulted in membrane damage and release of trapped liposomal glucose. The complement activity was inhibited by preheating (56 degrees C, 30 min), 10 mM Mg2EDTA3 or EGTA, and by prior adsorption with insoluble immune complexes. Almost all human sera had some reactivity, but it ranged from very low levels (less than 7% liposomal glucose release) to very high levels (greater than 50% glucose release). Complement activation appeared to be mediated by a serum factor which could be removed by adsorption and which was partially heat labile. The factor was transferred by adding heated high reacting human serum to unheated low reacting human serum, or to guinea pig serum. The serum factor, although quantitatively diminished in potency due to heat lability, caused equal activation of each of these two latter complement sources in the presence of high cholesterol liposomes. It did not cause activation of C4-deficient guinea pig complement. These data suggested that the classical complement pathway was activated. The liposomal membrane composition had an influence on this phenomenon. Activities of about half of the human sera were enhanced when galactosyl ceramide, or ceramide alone, was present in the liposomes. Activity was enhanced by longer fatty acyl chain lengths of lecithin when dimyristoyl-, dipalmitoyl-, or distearoyllecithin was employed in the liposomes. Liposomes containing sphingomyelin as the only phospholipid were not sensitive to cholesterol-dependent complement-mediated damage. It was concluded that human complement was activated in the presence of high concentrations of membrane cholesterol and that this was caused by an uncharacterized serum factor and was influenced by the lipid composition of the membrane.     

Ulnar nerve palsy in Paget's disease

A 73-year-old housewife with enlargement of her distal right humerus and especially the medial epicondyle due to Paget's disease developed an ulnar nerve palsy. Transposition of her ulnar nerve anterior to her elbow completely relieved her symptoms. A similar case of ulnar nerve palsy associated with expansion of the distal humerus due to Paget's disease seems not to have been previously reported.     

Color-luminance interaction: data produced by oblique cross masking

Threshold-elevation (TE-) versus-mask-spatial-frequency (SF) curves and TE-versus-mask-contrast curves, produced by the oblique-masking technique, were reported for uncrossed stimuli (color-test-on-color-mask and luminance-test-on-luminance-mask) [Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993) and Vision. Res. 23, 873 (1983)]. The technique minimizes the artifacts that are due to spatial phase effects, spatial beats, spatial probability summation, and local cues. My goal was to measure these curves for crossed stimuli (color-test-on-luminance-mask and luminance-test-on-color-mask) by this oblique-masking technique and to compare the curves with those reported in previous studies. For this purpose threshold contrasts were measured by a yes-no procedure with randomized double staircases. Test targets were vertical spatially localized (D6) patterns, and masks were oblique sinusoidal patterns; both the test and the mask were presented simultaneously, for 2 s (Gaussian window), on a color monitor interfaced with an ATVista system and a Powell achromatizing lens. The test SF's were 0.125, 0.5, 2, 4, and 8 cycles per degree (cpd); mask SF's were 0.031-16 cpd; and mask contrasts were 6.25%-50%. Furthermore, the Red-Green channel was defined by the minimum flicker and the hue cancellation techniques. Results show mostly masking effect (TE > 1) at contrasts above threshold; sometimes, separability (TE = 1) and above-threshold facilitation (TE < 1) effects were also observed, depending on the test SF, the mask SF, the mask contrast, and the subject. In general, the magnitudes of TE's are smaller and the TE-versus-mask-SF curves are slightly narrower for the oblique-cross-masking conditions than those for the respective oblique uncross masking. In addition, the TE-versus-mask-contrast curves for the crossed conditions are mostly shallower than those for the respective uncrossed conditions. Furthermore, mostly the color-luminance asymmetry (color masks luminance more than luminance masks color) is found, in mild form, for SF's > or = 0.5 cpd. For the lower SF of 0.125 cpd, there is either a lack of asymmetry or a very mild asymmetry of the opposite kind (luminance masks color slightly more than color masks luminance) seems to prevail. In general, the oblique-masking data shows mild asymmetry and reduced facilitation; both are consistent with reduced local cues, similar to those shown by randomized phase data, thus making the data suitable for SF analysis; moreover, at high contrast, the masking data are consistent with those reported in previous studies.     

Relative sensitivity of Loran-C phase tracking and cycle selection to CWI

Carrier-wave interference (CWI) is the most significant source of disturbance affecting the operation of the Loran-C radionavigation systems now being introduced into Europe. The article presents novel results of a study into the relative sensitivity to CWI of the phase-tracking and cycle-selection operations of Loran-C receivers.<>     

Association between human immunodeficiency virus and herpes simplex virus type 2 seropositivity among male factory workers in Zimbabwe

To determine the seroprevalence of herpes simplex virus type 2 (HSV-2), to identify correlates of infection, and to describe the correlation with human immunodeficiency virus (HIV) seropositivity, 224 HIV-negative and 191 HIV-positive male factory workers in Zimbabwe were screened for HSV-2-specific antibodies. HSV-2 seroprevalence was 35.7% among HIV-negative subjects and 82.7% among HIV-positive subjects. The weighted estimate of HSV-2 seroprevalence in this population is 44.6%. The correlation between HIV and HSV-2 remained significant after controlling for multiple sex partners, paying for sex, and history of sexually transmitted disease (adjusted odds ratio, 8.0; 95% confidence interval, 4.8-13.1). If the association between HSV-2 and HIV is causal, then the high seroprevalence of HIV and HSV-2 suggests that suppressive HSV-2 treatment should be considered as a strategy to reduce HIV transmission in this population. HSV-2 seroconversion may be a suitable surrogate end point to evaluate HIV prevention interventions.