Functional analysis of the deficit in semantic context processes in schizophrenic patients: an event-related potentials study.

AIM: Schizophrenic patients exhibit a deficit in the semantic context processing strategies which might be responsible for the language and communication disorders that are characteristic of this condition. The aim of our study was to identify the nature of the contextualization processes which are lacking in schizophrenic patients, by distinguishing between processes for the generation of expectations and processes of semantic integration. PATIENTS AND METHOD: Thirteen schizophrenic patients and 12 healthy controls performed two tasks: (a) a lexical decision task (LDT) with a highly structured sentence context and whose experimental characteristics made it possible to call strongly on predictive strategies, and (b) a LDT with classic semantic priming (the context being reduced to a single word). In this latter task, the small number of related words did not prompt the generation of expectations but instead called on the postlexical integration process. The event-related potentials (ERP) were recorded during the administration of the task. RESULTS AND CONCLUSION: In the sentence task, we observed a modulation in the N400 amplitude due to the presence of expectations both in the schizophrenic and control participants: predictable words evoked a small N400 amplitude compared to the non-predictable words. In contrast, in the simple (priming) task, the semantic link evoked an N400 amplitude modulation in the control group exclusively. Our results indicate that schizophrenics could be able to use context to activate expectations for the most highly predictable item, and that their deficit appears when the processing strategy is based on the integration of the context stored in working memory.

[Working conditions and morbidity with temporary loss of work capacity among metallurgists from Mill 300 of the Predmet firm--in Debelt]. / Usloviia na trud i zaboliaemost s vremenna netrudosposobnost sred metalurzite ot Stan 300 na firma "Promet"--Debelt.

Occupational hygienic and medico-statistical study is carried out in shop LOOM-300 for rolling of steel. The rate of exposure to chemical and dust factor of the workers is determined by means of index of exposure after the formula [formula: see text] The personal analysis of morbidity with temporary disability shows an increase of the basic indices "frequency" and "gravity" during the three year period. The per cent of the sick is higher in men, in the workers with higher index of exposure and in the younger age groups (up to 40 years old) with short labour of service, which certifies, for insufficient adaptation to the new working conditions. A conclusion is made, that the progressive increase of the indices of morbidity are serious warning for future high rate of morbidity, if labour hygienic and medico-preventive measures are not taken.

Psoriasis and drugs: influence of tetracyclines on the course of psoriasis.

Patients with psoriasis vulgaris (462) were studied by questionnaire to find the effect on psoriasis of drug therapy for intercurrent diseases or focal infections. Of 462 patients with psoriasis, in 76 (16.45%) the disease became more severe during drug therapy. Of these, 19 worsened after administration of tetracyclines, and in five psoriasis was precipitated after therapy with drugs of the tetracycline family. We suggest that tetracyclines should be avoided in patients with psoriasis and in healthy persons with a genetic predisposition (positive family history, human leukocyte antigens B13, B17, B27).