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It is well-known that the azido bridge gives rise antiferromagnetic (AF) or ferromagnetic (F) coupling depending on its coordination mode, namely end-to-end or end-on, respectively. The aim of the present work is to analyse the factors contributing to this different magnetic behaviour. The difference dedicated configuration interaction (DDCI) method is applied to several binuclear Cu(II) azido-bridged models with both types of coordination. In end-on complexes, the direct exchange and the spin polarisation contributions are found to be responsible for the ferromagnetic coupling. In end-to-end complexes, both the direct exchange and the spin polarisation are small and the leading term is the antiferromagnetic dynamical polarisation contribution. The most relevant physical effects are included in the DDCI calculations so that good quantitative agreement is reached for the coupling constant as well as the spin densities.

The effect of Cuprofilin, a newly synthesized C.(II)-chlorophyll complex, was assessed in rats with experimental atherosclerosis. The study was focused on changes in serum cholesterol, lipids, and triglycerides concentration as well as on serum and abdominal aorta Cu and Zn values. It has been ascertained that after 90 d in animals fed a rich lipid diet there was a statistically significant increase in serum cholesterol, triglycerides, and lipid concentration (p < 0.01). A significant augmentation of serum Cu values (p < 0.01) accompanied by a marked lowering of the same element in abdominal aorta (p < 0.01) was also found, as compared to the results registered in the control group. However, Cuprofilin, administered for 90 d in the group of animals with experimental atherosclerosis, significantly decreased the serum cholesterol, triglycerides, and serum lipid values (p < 0.01), increased copper content in aortic tissue (p < 0.01) and lowered serum copper concentration (p < 0.01) as compared to the untreated group. Moreover, in the aorta of administered animals the lipid infiltration has been demonstrated to be significantly diminished vs the untreated group.

Serum copper concentration increases significantly (p < 0.01) in rats with experimental atherosclerosis compared to a control group. The serum zinc, the zinc, and copper concentration in abdominal aorta and in liver decreases significantly (p < 0.05) compared to the control group. Administration of copper sulfate for 100 d in these animals induces a significant increase of serum copper (p < 0.01), decrease of serum cholesterol (p < 0.05) and increase of liver copper concentration as compared with the group fed only a high cholesterol diet. In the aorta of these animals the copper concentration increases and edema and lipid infiltration are considerably less than in the group of animals fed only a high lipid diet.

The authors followed up certain changes occurring at the level of the hypophysis-adrenal axis, during the development of experimental ulcers induced by pylorus ligature in rats treated with negative air ions. Previous experiments have shown that negative aeroionotherapy had a favourable influence on the prevention and evolution of gastric ulcers. The results of the present experiment showed that, under the influence of aeroionotherapy, the number of gastric ulcers/animal, and the relative weight of the adenohypophysis and of the adrenals glands decreased; the width of the fascicular zone of the adrenal cortex, and the volume of the cell nuclei in this fascicular zone also decreased.

A survey of the Compositae used in traditional medicine and as economic plants by Paraguayan country people was undertaken to identify the components of crude drugs traded by herbalists. Forty-five medicinal and economic species have been identified through field work in the rural areas and enquiries in the markets, as well as by examination of the literature in the Spanish language. Some crude drugs are shown to be mixtures of several closely-related species. The role of indigenous plant remedies within the local health care system is also discussed.

Samples of the sweet-tasting species Acanthospermum hispidum DC. (Compositae) (aerial parts), Boscia salicifolia Oliv. (Capparidaceae) (stem bark), Hovenia dulcis Thunb. (Rhamnaceae) (peduncles) and Inga spectabilis Willd. (Leguminosae) (arils) were acquired as part of a continuing search for high-intensity natural sweeteners of plant origin. Following their preliminary safety evaluation, the sweetness of these plants was traced to large amounts of sugars and polyols by taste-guided fractionation, which were identified and quantified using gas chromatography/mass spectrometry. The combined yields of sugars and polyols in the A. hispidum, B. salicifolia, H. dulcis, and I. spectabilis samples investigated were 6.9, 10.1, 18.4 and 12.1% w/w, respectively. These yields are much higher than the total saccharide and polyol content (2.4% w/w) of the sweet dried fruits of Thladiantha grosvenorii (Swingle) C. Jeffrey (Cucurbitaceae), a species which has previously been reported to contain more than 1% w/w of the intensely sweet triterpene, mogroside V. The dried leaves of Symplocos tinctoria (L.) L'Hérit. (Symplocaceae), which were not appreciably sweet, were found to contain only 2.0% w/w of sugars. The results of this investigation, therefore, suggest that unless the saccharide and/or polyol content of a plant part is well over 5% w/w, then it is unlikely to exhibit an overtly sweet taste, unless an intense sweetener is present.

Thirty-six healthy albino rats were divided into three groups and the histologic structure of the testes was examined after treatment: group 'C'--10 healthy control rats were untreated; group 'Pb'--eight rats received intraperitoneal injections of 8.5 mg per kg body weight lead acetate for 154 days (15 doses in all); group 'PbA'--eight rats intoxicated with lead, like group 'Pb' but which, during the last 21 days before killing, were treated with 5 ml per kg body weight per day of a 2% injectable solution of sodium aspartate. As compared with the controls, group 'Pb' showed alteration of the histopathologic pattern and reduction in the size of seminiferous tubules, basal membrane separation and a decrease in the cell content of the germinal layer, lesions of the spermatocytes and spermatids, and slight oedematous dissociation in the interstice. In 75% of the group 'PbA' animals, normal aspects similar to those of group 'C' were found.

The authors studied the influence of negative aeroionotherapy (AIT) on the gastric ulcer induced by pylorus ligature. After 24 hours the ligature was removed and the stomach was studied with respect to number and aspect of ulcers (hemorrhagic or not), periulcerous mucosa (edema, folds), acidity and microhemorrhage of gastric secretion. The animals were divided into 4 groups: C1 and C2 (controls)--not treated with air ions; P--prophylactically exposed 10 days before the operation to AIT; T--submitted to AIT prophylactically 10 days before the operation--therapeutically 5 days after operation. The results showed a favourable influence of AIT: the number of gastric ulcers was smaller; the regeneration processes in the mucosa were ameliorated; the gastric acid secretion and microhemorrhage diminished.

The problem of the inactivation of DDT deposits on dry mud surfaces is presented and its causes outlined. The phenomenon is found to be due to adsorption of the DDT crystals present on the surface; this adsorption appears to be the initial step in the catalytic decomposition of DDT by the iron oxides present in soils, since there is a direct relation between the amount of oxides present and their capacity to inactivate DDT deposits.The DDT-inactivating capacity of soils can be determined by testing them for catalytic activity in the thermal decomposition of DDT.The adsorption of DDT by soil is influenced by environmental relative humidity. Inactivated deposits may be reactivated by increase of the atmospheric humidity.Several substances proposed for the protection of the DDT deposit from inactivation were tested without success. Reference is made, however, to the encouraging findings of some other workers. Limewashing is recommended for the protection of DDT deposits.