Modification of primary and secondary metabolism of potato plants by nitrogen application differentially affects resistance to Phytophthora infestans and Alternaria solani.

Potato plants ( SOLANUM TUBEROSUM L. cv. Indira) were grown at two levels of N supply in the greenhouse. Plants supplied with 0.8 g N per plant (high N variant) showed significantly increased biomass as compared to plants without additional N fertilisation (low N variant). C/N ratio was lower and protein content was higher in leaves of the high N variant. The concentration of chlorogenic acids and flavonols was significantly lower in leaves from the high N variant. Whereas resistance to ALTERNARIA SOLANI increased when plants were supplied with additional nitrogen, these plants were more susceptible to PHYTOPHTHORA INFESTANS. After infection with both pathogens, we found a strong induction of p-coumaroylnoradrenaline and p-coumaroyloctopamine, which are identified for the first time in potato leaves and are discussed as resistance factors of other solanaceous plants.

The quality of autotransfused chest-drainage blood after cardiac surgery: a study of coagulation factors.

A wide range of experience, dating back as far as 1978, has been gained with both the hard-shell cardiotomy reservoir of the heart-lung machine and the Sorensen autotransfusion system as retransfusion systems. Three remains, however, a lack of knowledge regarding the quality of retransfused blood in systems of less complex construction which are already available on the market and involve the use of a pouch (Sentinel-Seal autotransfusion system and Pleur-evac collecting system). The present study entailed the investigation of blood from the chest drainages of twenty patients after cardiac surgery by using a simple retransfusion system (Sentinel-Seal autotransfusion system). In two postoperative groups of patients with low and high blood loss from chest drainage, we determined, in addition to free plasma hemoglobin, the following: factor XII, kallikrein-like activity, thrombin-antithrombin III complex, tissue-plasminogen and d-dimers. In the collective with a low blood loss, we found remarkable cell alterations as well as highly activated and advanced coagulation and an extraordinary fibrinolytic activity. If done at all, retransfusion by the Sentinel-Seal autotransfusion system should be restricted to the first four postoperative hours in cases of high blood loss.

[Autotransfusion and plasmapheresis in preparation for surgery. Behavior of coagulation]. / Autotransfusion und operationsvorbereitende Plasmapherese.

With the current day implementation of methods of autotransfusion one retransfuses if possible only washed red cell concentrates and eliminates the plasma. In the case of operations where patients undergo large blood loss, one must effect a substitution for the lost plasma volume and the lost clotting factors. In addition to electrolyte and colloidal solutions one can use a substitution of homologous and also autologous fresh frozen plasma (FFP). The effects of different substitutes on the clotting reaction has been investigated in 47 patients on whom extensive orthopaedic and also traumatologic surgical operations have been performed. By the combination of homologous blood and homologous FFP as also with autologous red cells and homologous FFP the clotting reactions remain the same. This determines the advantages of autotransfusion as compared with conventional techniques but, in addition, there is a saving in the usage of homologous blood. Where an operation can be planned in advance, the necessary FFP can be obtained from the patient. By utilisation of autologous FFP the operative and post- operative blood losses are reduced. As a result it is possible e.g. in total hip prosthesis, in approximately 90% of all cases, to operate without using homologous blood or plasma. The determined stability of AT III in autologous plasma--without AT III prophylaxis of thrombosis by Heparin is ineffective--and all other clotting factors leads to an expectancy of a not activated clotting mechanism and at the same time to low thrombosis risks.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of phytoalexin synthesis in soybean. Stereospecific 3,9-dihydroxypterocarpan 6a-hydroxylase from elicitor-induced soybean cell cultures.

A microsomal preparation from elicitor-challenged soybean cell suspension cultures catalyzes an NADPH-dependent and dioxygen-dependent 6a-hydroxylation of 3,9-dihydroxypterocarpan to 3,6a,9-trihydroxypterocarpan. The latter is a precursor for the soybean phytoalexin glyceollin. No reaction is observed with NADH. The 6a-hydroxylase is inhibited by cytochrome c. Optical rotatory dispersion spectra of the enzymatic product formed from racemic dihydroxypterocarpan and of the remaining unreacted substrate proved that the product has the natural (6aS, 11aS)-configuration and that hydroxylation proceeds with retention of configuration. The 6a-hydroxylase was also found in elicitor-challenged soybean seedlings. The results indicate that the 6a-hydroxylase is specifically involved in the biosynthesis of glyceollin.

[Selenium concentration and activity of glutathione peroxidase in lysate of human erythrocytes]. / Selenkonzentration und Aktivität der Glutathion-peroxydase im Lysat menschlicher Erythrozyten

The concentration of selenium in human red cells was measured by a fluorometric determination method after wet digestion of the biological material. In the red cells from the same blood samples the activity of the selenoenzyem glutathione peroxidase (EC 1.11.1.9) was determined with tertiary butyl hydroperoxide as acceptor substrate. The results show that only 10% of the total selenium content of human red cells is fixed to the enzyme. No correlation between the enzyme activity and the selenium concentration could be found. On the basis of these results can be presumed that the protective effect of selenium in glutathione peroxidase against oxidant damage of cells is not the only biological function of this element.