Interaction between ellagic acid and calf thymus DNA studied with flow linear dichroism UV-VIS spectroscopy.

The interaction between ellagic acid and DNA has been characterized with respect to the geometry of the ellagic acid-DNA complex, and the active form of ellagic acid has been identified. Optical spectroscopic methods have been employed to examine the interaction between double-stranded calf thymus DNA and ellagic acid in low-ionic-strength aqueous solutions at pH values of 5.5, 7.0, and 8. 8. Based on normal absorption titration and flow linear dichroism experiments, it is confirmed that the neutral form of ellagic acid present at pH 5.5 binds to double-stranded DNA. It is found that the plane of the ellagic acid chromophore is positioned at an angle relative to the DNA helix axis, which is in accordance with intercalation of ellagic acid in DNA. It is concluded that at higher values of pH no or a very limited amount of ellagic acid binds to DNA. These results prove that the direct interaction between ellagic acid and DNA must be taken into account when evaluating the mechanism underlying the observed biological effects of this plant phenol.

Pharmacological characterization of positive inotropic derivatives of 4-amino-7-methyl-1,8-naphthyridine-3-carboxylic acid.

The positive inotropic effect of a series of 4-amino-7-methyl-1,8-naphthyridine-3-carboxylic acid derivatives was compared with the effects of known inotropic agents (ouabain, dihydroouabain, isoproterenol, adrenaline, histamine and isobutylmethylxanthine) in guinea-pig atrial and ventricular myocardial preparations. With respect to their functional effects, the 1,8-naphthyridine compounds are clearly different from drugs acting on the cAMP system, whereas several similarities with cardiac glycoside effects were found. Their ability to inhibit [3H]ouabain binding in guinea-pig cardiac membranes correlates well with their effects on myocardial contractile force. However, the latter effect was exerted by tenfold lower concentrations. The dissimilarities found between the 1,8-naphthyridines and digitalis may be due to a different type of interaction with the binding site on the (Na(+) + K+)-ATPase.

Psychosocial, neuropsychological and neurological status in a sample of heart transplant recipients.

The sample for this psychosocial follow-up study was formed using the 71 surviving patients from a total of 100 who underwent heart transplantation up until March 1990 at Kiel University Hospital. Forty of these could be investigated comprehensively. The neurological investigation comprised EEG and auditory and visually evoked potentials. The psychological investigation started with several neuropsychological tests; additionally all patients were interviewed and they completed questionnaires concerning anxiety, depression, ways of coping, personality characteristics and life satisfaction. Within the entire sample, there were few indications for specific psychological impairment. The psychosocial status of the patients was not significantly related to the time which had elapsed since they underwent transplantation. There were few associations between neuropsychological and psychosocial data, and several indicators of early postoperative complications which are described in the literature (e.g., length of stay in the intensive care unit). Clinically relevant subgroups (formed on the basis of neuropsychological test results, anxiety and depression) did not differ in terms of these indicators. Nevertheless, a considerable proportion of the patients (25%) were characterized by having a higher level of affective and neuropsychological impairment. Although based upon retrospective investigations, the results of this follow-up generally correlate with those gained from Anglo-American countries. In interpreting the results one needs to consider the possible influence of premorbid personality characteristics as well as denial which may be typical for patients undergoing heart transplantation.

[Generalized diabetic dermangiopathy]. / Generalisierte diabetische Dermangiopathie.

Report on a 37-years old male with infantile diabetic manifestations. He is suffering now from severe diabetic retinopathy, nephropathy, neuropathy and a fresh myocardiac infarction. The entire integument is spotted with single brownish-red patches, each one from 3 to 10 mm in diameter. The patches are partly topped by a slight scale. After healing an atrophic macule is left. They meet the pretibial "Atrophic circumscribed skin lesions" described formerly by Melin. The exanthema was therefore classified as a generalized diabetic dermangiopathy. It is suggested to subdivide the diabetic dermangiopathies in a pretibial type Melin and a generalized type Bauer-Levan. Histologically a severe vasculitis can be found with all types.

[Immunomorphological and ultrastructural findings on the musculature in progressive scleroderma]. / Immunmorphologische und ultrastrukturelle Befunde an der Muskulatur bei progressiver Sklerodermie.

Muscle biopsies taken from 30 patients with generalized scleroderma were studied immuno-histologically as well as by light and electron microscopy. The immunological investigations have demonstrated that an increase of IgM and/or complement depositions in capillaries and in the walls of small arteries have been involved in most cases. Similar alterations were found in the subsarcolemmal zone. Vascular Ig-G precipitates were observed in the later stage of the disease only, whereas a positive reaction of fibrinogen have been proved in the most cases. By light and electron microscopy a variety of pathologic alterations have usually been found, but the most prominent changes involved were thickening of the capillary basement membrane and interstitial fibrosis. Scattered cellular infiltrates consisting of lymphocytes, histiocytes and plasmocytes were also seen either perivascularly or throughout the interstice. Around fibroblasts and capillaries, fine protocollagen fibrils and glycosaminoglycan filaments have been observed. They may partly represent fibrogenesis. Filamentous structures could be seen within the cytoplasm of numerous fibroblasts.