Responses to irrelevant probes during task-induced negative and positive shifts.

The functional significance of task-induced negative and positive cortical shifts were tested with the probe-stimulus method. Both shifts were induced within the same experimental situation in three variants of a CNV paradigm, where a slow positive wave (a variant of P300) appeared following S2. In Experiment I and II, S2 called for making or withholding a motor response (go/no-go); in Experiment III, S2 informed the subject about the correctness of a previous guess. Irrelevant probe-stimuli were applied in conjunction with the task during the CNV, the post-S2 positivity and the intertrial interval (ITI). The probe-evoked vertex EPs were smaller during the post-S2 positivity as compared to the CNV and the ITI. This was true not only for the motor task but also for the guessing task, where the effect is unlikely to have been contaminated by motor potentials. This indicates that positive shifts have an inhibitory effect on the processing of irrelevant probe-stimuli and possibly on information-processing in general.

[Post-traumatic avascular necrosis of the tubereculum majus]. / A tuberculum majus posttraumás, avaszkuláris nekrózisa.

Posttraumatic avascular bone necrosis occurs rarely on the major tubercle. In the early stage it may cause diagnostical problem at the evaluation of the Roentgenogram. It can be confused with a tumor, metastasis and tuberculosis. Later it shows a characteristic picture and causes rarely diagnostic difficulties. Authors describe a case of their own and discuss briefly the supposed causes of the disease, the possibilities of early recognition and treatment.

[Value of angiography in hemangiopericytomas]. / Wert der Angiographie bei Hämangioperizytomen.

Haemangiopericytoma is a rare type of tumour which mostly develops in the soft parts. The article reports on the manifestations of one tumour each in the thigh and pelvis. The angiogram shows displacement of the major arteries, the tumour-supplying vessels penetrate into the growth by means of one or several peduncles, and intensive coloration takes place during the parenchyma phase. However, the "typical angiographic image" was seen in one of the two cases only.

[Case report of vertebral osteomyelitis following operation for herniated disk (author's transl)]. / Discus hernia mütét után fellépö csigolya osteomyelitis esete.

Authors describe a case of vertebral osteomyelitis as assessed with help of X-ray pictures and clinical signs, which developed following an operation for herniated disk, and healed on conservative treatment. This complication was only once encountered in a material of 1406 operated cases. It is pointed out that with increasing number of hemilaminectomies this complication might appear more often.

[Effect of direct current on bone regeneration]. / Wirkung von Gleichstrom auf die Knochenregeneration.

The data on bone biocurrent and on the bone regenerating effect of low intensity direct current are discussed. The stimulator constructed by the authors is described. With its help an improved callus formation could be achieved on the osteotanised femur of the rabbit.