Selective elimination of a large proportion of cortical synapses constitutes the last major stage in brain development which is linked to sexual maturation. Various neurodevelopmental theories have proposed an association between schizophrenia and late brain maturational events. Based on epidemiological and psychopharmacological data, Saugstad hypothesised a relationship between timing of puberty, synaptic density and psychosis proneness. Early puberty should result in an earlier end to synaptic pruning, a larger number of surviving connections and an increased risk for affective psychosis. In contrast, in late maturers prolonged synapse elimination should lead to lower synaptic density which constitutes a diathesis for schizophrenia. We used EEG coherence as a neurophysiological measure of cortico-cortical connectivity. Late maturers were expected to show higher coherence, especially for short-distance connections where lower synaptic density should lead to decreased local differentiation. EEG was recorded from 12 bipolar derivations in 19 early and 19 late maturing subjects of both sexes under conditions of rest and photic stimulation at different flicker frequencies. Whereas there were no coherence differences between early and late maturers during rest, both groups differed during flicker stimulation. As hypothesised, late maturers were found to have higher short-distance coherence. Late maturers were also found to have higher intrahemispheric long-distance coherence. These findings were restricted to delta, alpha and beta 2 bands and were more pronounced in males. Our findings are interpreted in terms of a structural difference in neuronal connectivity between extreme early and late maturers.

Adult↗

PubMedDate not supplied

[Josamycin in the treatment of acute maxillary sinusitis].

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Acute Disease↗

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Endoscopic microsurgical dissection of the esophagus (EMDE).

This paper presents endoscopic microsurgical dissection of the esophagus (EMDE), a surgical technique for the therapy of esophageal cancer which improves blunt esophageal dissection with the aim of reducing postoperative morbidity and mortality. A mediastinoscope with integrated operative instrument channel, fibre bundles, optic and rinsing channel has been developed whereby precise and atraumatic esophageal dissection is possible via a cervical access incision. Between 1989 and 1993, 37 patients were operated on using the EMDE technique and are compared with 48 patients operated on during the same period by the thoraco-abdominal route. The operative duration was reduced by the new technique, and although the number of severe complications was not significantly different between both groups, the rate of pulmonary and cardiac complications was reduced. The mortality rate was 10% for EMDE patients and 14% for the thoraco-abdominal procedure, and there was no difference in the long-term survival rate. As distinct from procedures requiring a thoracotomy for esophageal dissection, EMDE permits ventilation of both lungs throughout the entire operation and reduces the total operative trauma.

Dissection↗