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H Sippel

Publications and source records attributed to H Sippel.

25 records · Page 2Linked to original sources
PubMed1982

Acute solvent-ethanol interactions with special reference to xylene.

Acute ethanol ingestion inhibits the metabolism of the common industrial solvents trichloroethylene and dimethylformamide. The solvents in turn may interact with ethanol metabolism as shown by an accumulation of acetaldehyde and occasional symptoms of alcohol intolerance. It was recently found that mutual metabolic interaction occurs even in the context of ethanol ingestion (0.8 g/kg in single dose) combined with subsequent inhalation exposure to m-xylene (6.0 & 11.5 mmol/m3 (140 & 280 ppm), over 4 h). Ethanol impaired the metabolic clearance of m-xylene, raised the blood xylene concentration, and decreased the urinary excretion of methylhippuric acid. Thus, ingestion of ethanol is a noticeable source of error in the biological monitoring of xylene uptake. Some people appear to be susceptible to combined ethanol-xylene exposure and may develop nausea and dermal flush.

Alcohol Drinking↗
PubMed1978

Effect of ethanol on neuronal activity in the parietal association cortex of alert monkeys.

The effect of alcohol was studied in alert monkeys on the cellular mechanisms of the posterior parietal association cortex, a region that normally participates in visuo-spatial co-ordination of hand movements. In thirty-two experiments, the effects of intracardiac administration of ethanol were monitored by the intracortical multiple-unit recording technique. Alcohol produced rhythmic groupings of the spontaneous impulse activity; the rhythm was accentuated by closing the eyes. The dominant frequency of this rhythm (3.5 to 1 Hz) correlated inversely with the blood alcohol level. Three groups of response types were studied in Brodmann's area 7. At 8 of 12 recording sites, a close correlation was observed between the monkey's reaching accuracy and the magnitude of integrate multineuronal responses to reaching with the contralateral arm under visual guidance, or to grasping an object. Half of the 10 recording sites which were activated by complex visual stimulation also showed a close correlation with the behavioural action of alcohol. Least sensitive to alcohol were somatosensory responses; only 3 of 10 of such recording sites were influenced by moderate doses of alcohol. Larger doses producing coma increased the proportion of responses blocked by alcohol, whereas no effects were observed in the adjacent primary somatosensory cortex. Our results show that the posterior parietal association cortex is very sensitive to the action of alcohol. Moreover, these findings support the theory that the action of alcohol in various parts of the central nervous system depends on the complexity of synaptic contacts to the location under study.

Action Potentials↗
PubMedDate not supplied

A web-based data collection system for clinical studies using Java.

Data collection in multi-centre controlled clinical trials is a major problem. We describe a web-based documentation system for data collection via the Internet we have developed in Java. It keeps both the platform independent program (a Java applet) and the database on a single server to which the participating centres have access at any time. It is based on a three-tier model where client requests are handled and monitored by an application server (a Java application). We show the advantages such a system has over the HTML/CGI combination which is often used for database access, as well as possible extensions, e.g. connection to a data dictionary. Finally, we discuss the security problems which arise by the use of the Internet for data collection.

Data Collection↗