Neuropeptide control of rat gastric mucosal blood flow. Increase by calcitonin gene-related peptide and vasoactive intestinal polypeptide, but not substance P and neurokinin A.

Submucosal blood vessels of the mammalian stomach are densely innervated by neurons containing calcitonin gene-related peptide (CGRP), substance P, neurokinin A, and vasoactive intestinal polypeptide (VIP). Because all these peptides are vasodilators in certain vascular beds, we tested the hypothesis that rat alpha-CGRP, rat VIP, substance P, and neurokinin A are candidate mediators of noncholinergic vasodilator neurons in the gastric mucosa and submucosa. The experiments were performed on urethane-anesthetized Sprague-Dawley rats. Gastric mucosal blood flow (GMBF) was measured by the hydrogen gas clearance technique, and the peptides were infused close arterially to the stomach via a catheter inserted retrogradely in the splenic artery. Basal GMBF was in the range of 35-50 ml/min/100 g. Infusion of rat alpha-CGRP (15 and 75 pmol/min) significantly increased GMBF in a dose-dependent manner, whereas mean arterial blood pressure was significantly lowered only by the higher dose of CGRP. Substance P (125 and 625 pmol/min) and neurokinin A (50 and 250 pmol/min) failed to alter GMBF, although the higher dose of each peptide led to a significant decrease in mean arterial blood pressure. Infusion of rat VIP (25 pmol/min) failed to affect GMBF and mean arterial blood pressure, whereas a fivefold higher dose of VIP (125 pmol/min) led to a significant rise of GMBF and to significant hypotension. These findings indicate that substance P and neurokinin A are unlikely to be of physiological significance for the regulation of GMBF. CGRP and VIP, however, can be considered as candidate mediators of submucosal nerve endings involved in the neural control of GMBF.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of aldosterone antagonists in juvenile heart surgery

In children with congenital heart disease duration and extent of hyperaldosteronism and the influence of spironolactone after surgery with a heart-lung-machine, were evaluated by direct measurement of plasma aldosterone levels. Secondary hyperaldosteronism as seen in 11 patients without spironolactone-therapy after surgery did not persist very long. 14 children receiving spironolactone immediately after surgery showed an onset of drug efficacy at a period when plasma aldosterone in the group without spironolactone had begun to fall. As a practical consequence, spironolactone treatment should be initiated a few days prior to surgery in order to achieve full efficacy on the day of surgery.     

Die Anwendung der Biegeschwingermethode zur Messung von Blutdichte und Hämatokrit

Zusammenfassung Dichtemessungen der Genauigkeit von 0,01 g/l wurden an menschlichen Blutproben sowie an Plasma und Erythrozytenkonzentrat mit Hilfe eines Dichtemeßgerätes nach der Biegeschwingermethode vorgenommen.Zwischen Blutdichte und Hämatokrit wurde eine hochsignifikante lineare Beziehung gefunden. Bei Kenntnis der Plasma- und Blutzelldichte einer Blutprobe kann der Hämatokrit aus der Blutdichte genauer ermittelt werden als mit der Zentrifugationsmethode, was insbesondere für den Nachweis geringgradiger Änderungen, etwa durch Verschiebung des transkapillären Filtrationsgleichgewichtes, von Interesse ist.Aus der statistischen Verteilung der Plasma- und Erythrozytendichtewerte ergibt sich ferner der Schwankungsbereich der Blutdichte für bestimmte Hämatokritwerte und umgekehrt.Diese Arbeit wurde vom Fonds zur Förderung der Wissenschaftlichen Forschung unterstützt (Projekt-Nr. 3447)     

Adolescent substance-use assessment: methodological issues in the use of the ADAD (Adolescent Drug Abuse Diagnosis)

During the past twenty years, various instruments have been developed for the assessment of substance use in adolescents, mainly in the United States. However, few of them have been adapted to, and validated in, French-speaking populations. Consequently, although increasing alcohol and drug use among teenagers has become a major concern, the various health and social programs developed in response to this specific problem have received little attention with regard to follow-up and outcome assessment. A standardized multidimensional assessment instrument adapted for adolescents is needed to assess the individual needs of adolescents and assign them to the most appropriate treatment setting, to provide a single measurement within and across health and social systems, and to conduct treatment outcome evaluations. Moreover, having an available instrument makes it possible to develop longitudinal and trans-cultural research studies. For this reason, a French version of the Adolescent Drug Abuse Diagnosis (ADAD) was developed and validated at the University Child and Adolescent Psychiatric Clinic in Lausanne, Switzerland. This paper aims to discuss the methodological issues that we faced when using the ADAD instrument in a 4-year longitudinal study including adolescent substance users. Methodological aspects relating to the content and format of the instrument, the assessment administration and the statistical analyses are discussed.