13C-ethanol and 13C-acetate breath tests in normal and aldehyde dehydrogenase deficient individuals

Four normal and five aldehyde dehydrogenase (ALDH) isozyme I deficient individuals were subsequently loaded with (1-13C)ethanol and (1-13C)sodium acetate and the conversion of the label to 13CO2 was determined in expired air by isotope ratio mass spectrometry. In the 13C-acetate breath test, both groups showed virtually identical recovery of the label in expired air, namely 48.5 +/- 2.3% (mean +/- S.D.) for normal and 46.8 +/- 5.7% for deficient individuals. However, in the 13C-ethanol breath test, both the groups performed differently. On average, although a certain overlap of the single data was observed, the recovery of the label after four hours was 43.4 +/- 3.8% for the normal and 35.6 +/- 6.8% for the ALDH deficient subjects. These findings suggest a slower conversion of ethanol to carbon dioxide in aldehyde dehydrogenase deficient individuals, which may be another consequence of this deficiency besides the higher plasma acetaldehyde levels observed after ethanol loading in comparison to individuals with normal aldehyde dehydrogenase activity.     

Hydroxyethyl starch does not improve pancreas preservation with HTK

The effect of hydroxyethyl starch on pancreas preservation with cardioplegic histidine-tryptophan-ketoglutarate solution (HTK) was investigated. The study was performed using an in vitro reperfusion system of the porcine pancreas. During organ preservation pancreatic weight, arterial pressure, volume flow, and washout of amylase and lactate were quantified. Addition of hydroxyethyl starch did not affect arteriovenous volume flow or washout of amylase and lactate during protective perfusion after pancreas preparation. However, hydroxyethyl starch in HTK prevented an increase in pancreatic weight at the end of the protective perfusion (102.2 ± 4.55% vs 127.8 ± 4.62% in controls; p < 0.005) and after 24 h cold ischemia (72.9 ± 3.91 % vs. 83.5 ± 3.49 % in controls; p < 0.05). Hydroxyethyl starch did not affect postischemic organ quality assessed during reperfusion in a perfusion chamber by pancreatic vascular resistance, amylase and lactate release, insulin secretion, and oxygen consumption. We conclude that hydroxyethyl starch does not bring about any further improvement in immediate postischemic organ quality assessed in an in vitro reperfusion system.

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Hydroxyäthylstärke bringt keine verbesserung der pankreaskonservierung mit HTK-Lösung

Zusammenfassung Der Effekt von Hydroxyäthylstärke auf die Pankreaskonservierung mit der kardioplegischen Histidin-Tryptophan-Ketoglutarat-Lösung (HTK) wurde untersucht. Die Studie wurde an einem Reperfusionssystem des in vitro perfundierten Pankreas vom Schwein durchgeführt. Während der Organprotektion wurden das Pankreasgewicht, der arterielle Perfusionsdruck, die Volumenstromstärke sowie Amylase und Laktat im Perfusat bestimmt. Der Zusatz von Hydroxyäthylstärke bewirkte keine Änderung der Volumenstromstärke oder der Amylase- und Laktatauswaschung aus dem Organ während der Protektion. Allerdings konnte eine Zunahme des Organgewichts am Ende der protektiven Perfusion (102,2 ± 4,55% vs. 127,8 ± 4,62%in Kontrollen; p < 0,005) und nach 24 h kalter Ischamie (72,9 ± 3,91 vs. 83,5 ± 3,49% in Kontrollen; p < 0,05) durch Hydroxyathylstärke in der HTK-Lösung verhindert werden. Hydroxyäthylstärke hatte keinen Einfluß auf die postischämische Organqualität, die während der Reperfusion in einer Perfusionskammer anhand von Gefäßwiderstand, Amylase- und Laktatfreisetzung, Insulinsekretion und Sauerstoffverbrauch abgeschätzt wurde. Wir schließen daraus, daß Hydroxyäthylstärke die sofort nach einer Ischämie in einem In-vitro-Reperfusionssystem bestimmte Pankreasfunktion nicht weiter verbessert.

     

Neoglycoprotein binding to colorectal tumour cells: Comparison between primary and secondary lesions

Summary Biotinylated neoglycoproteins are useful to determine the expression of sugar receptors (lectins) histochemically in routinely processed tissue sections. Assessment of the presence of distinct receptor classes with specificity to-galactosides and to- or-N-acetylgalactosamine, selected on the basis of their potential relevance for recognition processes within the metastatic cascade in murine model systems, was performed for a common human tumour type, colorectal cancer. The four different types of neoglycoproteins, derived from covalent attachment of commercially available derivatives of-N-acetylgalactosamine, differed only quantitatively in their capacity to detect specific binding on cultured cells and tissue sections, thus posing no major restriction on the choice of synthetic process for histochemical efficiency of the product. Glycocytological application revealed specific probe binding and a regulation of level of receptor expression for a human colon carcinoma cell line primarily forN-acetylgalactosamine-specific receptors upon retinoic acid-induced differentiation. Monitoring of sections of the 12 cases of primary and secondary colorectal lesions invariably disclosed the presence of the respective receptors, the extent of cell labelling in primary tumours and metastases being similar. Establishment of metastases, even in different target organs, is apparently not followed by a major phenotypic variation in this feature.     

Alteration of the LRP1B gene region is associated with high grade of urothelial cancer

We have delineated regions of interest at chromosome 2q21.2, 2q36.3, and 2q37.1 by deletion mapping of 114 urothelial cancers (UC). Altogether, 17%, 18%, and 63% of the G1, G2, and G3 tumors displayed loss of heterozygosity at chromosome 2q, respectively, The region at 2q21.2 was narrowed down to the LRP1B gene (NT_005129.6). Hemi- and homozygous deletion at the LRP1B gene region was seen in 31 of 114 UCs. Only 8% of the UCs with G1 and none with G2 tumors showed loss of heterozygosity at the LRP1B gene, whereas 49% of the G3 UCs had allelic loss at this region. RT-PCR analysis of the LRP1B gene showed the lack of expression of several exons in 2 of 9 cases analyzed. Our analysis suggests that the LRP1B gene is a candidate tumor suppressor gene in UCs.     

A novel isoform of the smooth muscle cell differentiation marker smoothelin

Studies on smooth muscle cell differentiation and those on vascular development in mouse and humans have long been hampered by the lack of suitable markers. Here we describe a novel, large isoform of smoothelin, a structural protein of differentiated, contractile smooth muscle cells. The protein, which is highly conserved in mouse and humans, shows homology with other cytoskeleton-associated smooth muscle cell proteins and contains an actinin-type actin-binding domain. Northern blot analysis from various mouse organs identified short and long smoothelin mRNA forms, which exhibit distinct tissue expression patterns. The short form is highly expressed in visceral muscle tissues such as intestine and stomach and is not detectable in brain, while the long mRNA form is expressed in all vascularized organs. These results may provide new tools and approaches to study both smooth muscle cell differentiation and proliferative vascular disease. Received: 25 August 1998 / Accepted: 19 October 1998     

Determination of Dissolved Oxygen in Heterogenous Systems Particularly in Emulsions and Oily Liquids

The content of dissolved oxygen was determined by four independent methods in a series of non-aqueous or heterogenous systems. The Lex-O₂-Content Analyzer represents a fast and simple apparatus that employs a coulometric oxygen assay with Hersch cell detection. A comparison of the results with different methods demonstrates the reliability of the Lex-O₂ in the determination of oxygen dissolved in heterogeneous or non-aqueous systems. Therefore, this apparatus can be recommended for the measurement of oxygen in oxygenator or perfusion fluids, as well as in blood substitutes or other oxygen transporting systems.