54 healthy volunteers (25-82 years) were studied in an "auditory oddball" event-related potential paradigm. The tones (80%, 800 Hz; 20%, 1,600 Hz) were presented via two earphones in an randomized form. The rare tones were counted by the volunteers. Each volunteer was tested with the conditions, "eyes open" and "eyes closed". We found: An increase of the P3-latency of 0.92 ms/year (280 ms in the age of 20 years), and a decrease of P3-amplitude of 0.14 microV/year (17.2 microV in the age of 20 years). In contrast to other studies, the amplitude of the P2-wave (12.8 ms in the age of 20 years) and the latency of the P2-wave (160 ms in the age of 20 years) was not influenced by age. Females showed greater amplitudes of the P2- and P3-components. Females showed a clearly smaller increase on P3-latency with age (0.25 ms/year, starting with 296 ms in the age of 20 years) than males (1.3 ms/year, starting with 272 ms in the age of 20 years). The condition "eyes open" or "eyes closed" did not influence the late auditory evoked potentials. The results were interpreted by taking into account the great sensitivity of the late evoked potentials for changes of the state, which can be defined as well on the neurophysiological level as on the behavioural level.

Acoustic Stimulation↗

PubMedDate not supplied

Intrauterine repair of gastroschisis in fetal rabbits.

OBJECTIVE: Infants with gastroschisis (GS) still face severe morbidity. Prenatal closure may prevent gastrointestinal organ damage, but intrauterine GS repair (GSR) has not been established yet. METHODS: In New Zealand White rabbits we developed and compared GS versus GSR: creation of GS was achieved by hysterotomy, right-sided laparotomy of the fetus and pressure on the abdominal wall to provoke evisceration. GSR was accomplished by careful reposition of eviscerated organs and a running suture of the fetal abdominal wall. For study purposes, 18 animals were divided equally into 3 groups: GS, GS with GSR after 2 h, and unmanipulated controls (C). Vitality was assessed by echocardiography. After 5 h all animals were sacrificed. RESULTS: GSR inflicted no increased mortality, because all fetuses survived GS or GS with GSR. All fetuses with GS demonstrated significant evisceration of abdominal organs. In contrast, the abdominal wall of the fetuses from GSR was intact. CONCLUSION: The present animal model demonstrated the technical feasibility and success of an intrauterine repair of GS for the first time. However, further long-term studies (leaving GS and GSR in utero for several days) will be necessary to compare survival rates and intestinal injury, motility or absorption. The clinical application of GSR in utero remains a vision so far.

Abdomen↗