Contour suppression during stroboscopic motion and metacontrast

Findings of visual contour masking obtained when two stationary and spatially separated stimuli are presented briefly and successively in time indicate that the contour masking typically observed while viewing a stimulus in real movement also occurs while viewing a stimulus in stroboscopic movement. Additional results indicate that the loss of detailed contour information attending stroboscopic movement may contribute to. though not constitute, the contour suppression effects observed in metacontrast.     

The sonographic appearance of metastatic malignant melanoma

The sonographic findings in the abdomen in 42 patients with intra-abdominal metastases from malignant melanoma are described. Multiple metastatic sites were seen in 10 of the 42, with the liver being the organ most often involved. Liver metastases were predominantly of low echo amplitude, and fluid was visible within 30 per cent of all metastases, probably being an indicator of the frequency of hemorrhage into these lesions. Bulky disease, especially in the retroperitoneum, was unusual in the patients examined, which probably accounts for the absence of hydronephrosis as a complication.     

Post-traumatic abnormalities of the pubic bone simulating malignancy

Three cases are presented in which unusual healing patterns of pubic features simulated malignant processes. Consideration of trauma as an etiologic factor in such cases may obviate the need for extensive clinical and histologic evaluation.     

Isonucleolinosis in cell cultures of human meningiomas.

In cell cultures of 13 human meningiomas the internal structure of the nucleolus was stained by the toluidine blue-molybdate method and compared with the karyotype of the tumors. Although some of the meningiomas had lost or gained one or more chromosomes and had undergone structural aberrations, all of them showed isonucleolinosis, which is normally found only in cells with normal karotype. It seems possible that the occurrence of iso- or anisonucleolinosis is not a specific sign of euploidy or aneuploidy, but of benignity or malignancy of the examined tissue.