Transport of amino acids in the splanchnic bed by blood plasma and blood in the preruminant calf]

Three preruminant calves were fitted with catheters in portal and hepatic veins and in a mesenteric artery. Two electromagnetic flowmeter probes were clipped around the portal vein and the hepatic artery. The calves were fed either a diet with a low (L) or a high (R) abomasal emptying rate for dietary proteins. Blood flow and free amino acid levels in plasma (P) and blood (S) were determined before the morning meal and during the following 7 h. In the portal vein, for most amino acids P/S ratios were correlated to the net amino acid balance of the digestive tract measured in plasma. By contrast in the hepatic vein, these ratios were mainly correlated to hepatic balance measured in whole blood. Correlations between digestive tract and hepatic balance calculated using either plasma or whole blood pool were different for some amino acids. This suggests that amino acid exchange between plasma and blood cells is low and absorbed amino acids are mainly transported to the liver by plasma, whereas whole blood rather than plasma is concerned in amino acid exchanges in the liver.     

First descriptions of Coelometopini pupae (Coleoptera: Tenebrionidae) from Australia,Southeast Asia and the Pacific region,with comments on phylogenetic relationships and antipredator adaptations

Abstract. The pupal stage of ten Coelometopini species occurring in Australia, New Guinea, Southeast Asia and the Pacific region are described and a key for their identification is provided. The species are Chrysopeplus expolitus Broun, Derosphaerus hirtipes Kaszab, Hypaulax crenata (Boisduval), Leprocaulus borneensis Kaszab, Metisopus purpureipennis Bates, Promethis carteri Kaszab, P. nigra (Blessig), P. quadraticollis (Gebien), P. quadricollis Pascoe and P. sulcigera (Boisduval). The gin trap structures of D. hirtipes and P. quadraticollis are described in detail using scanning electron micrographs. A summary of antipredator structures of all known Coelometopini pupae is given. The phylogenetic value of pupal characters is assessed at intra‐ and intergeneric levels within the tribe.     

Thermography as a predictive tool for laser treatment of port-wine stains

The argon laser, which has been proven both useful and safe for port-wine stain therapy, interacts with the hemoglobin of the vessels. In a percentage of cases, this treatment is still inefficient, and there is a lack of correlation between these bad results and clinical or histologic criteria. Thermography, which explores the vascularization of the port-wine stain, leads us to consider port-wine stains from a physical point of view. This very simple test shows no correlation with the clinical parameters of port-wine stain but is closely related to the results obtained with laser therapy. It seems to be a good criterion to estimate the argon laser treatment prognosis.     

Optimization of transverse alternating field electrophoresis for strain identification of Leuconostoc oenos

Genomic DNA of several strains oof oenological lactic bacteria belonging to the species Lactobacillus plantarum, Leuconostoc oenos and Pediococcus pentosaceus was digested by the rare-cutting endonucleases ApaI and SmaI. The restriction products were separated by transverse alternating field electrophoresis (TAFE). The size of the genome of L. oenos estimated by adding the molecular size of the ApaI fragments was on average 1320 kb. A strong polymorphism was observed between the strains, which could be easily differentiated except for two industrial strains of L. oenos. A simple modification of the TAFE apparatus is proposed to improve the separation of the DNA fragments. Correspondence to: J.-N. Hallet     

Primordial germ cell proliferation in the salamander Pleurodeles waltl: genetic control before gonadal differentiation

PGC counts were carried out on larvae of Pleurodeles waltl (urodele amphibia) issued from standard, monosexual male and monosexual female offspring while the genital ridges were settling. During this period, which is characterized by a zero mitotic index (and is therefore called the Po period), and which lasts from stage 35 to stage 41, no PGC proliferation occurs. A statistical analysis indicated that PGC counts per larva are sex genotype independent and that offspring may be divided into three groups with average PGC counts of 96.9, 51.0 and 31.1, respectively. A fourth group with an average of 18.3 PGCs has been identified using experimental larvae reared at 30 degrees C from stage 30. The PGC count of 96.9 would result from at least three mitotic cycles. Before the Po period, germ cells are not identifiable. A hypothesis concerning genetic control of PGC proliferation before Po was deduced from this analysis.     

A new approach for using cofactor dependent enzymes: example of alcohol dehydrogenase

The use of enzymes requiring a cofactor as substrate in organic synthesis is still a problem since the cofactors are expensive. This study deals with a new approach consisting of using fragments of NAD+. Three fragments of NAD(H) are examined. The activities of NMN+ and NMNH are greatly improved by the addition of adenosine in ethanol oxidation and in cyclohexanone reduction, respectively. Nicotinamide mononucleoside is not active in the ethanol oxidation but the addition of AMP promotes this reaction.