Resumo Persea lingue Ness é uma árvore que vive principalmente na floresta temperada do centro-sul do Chile. As folhas são usadas na etnomedicina. O fruto é uma drupa similar ao abacate e que nunca foi pesquisada anteriormente. O objetivo deste estudo foi o de avaliar a citotoxicidade em células leucêmicas e as atividades antibacterianas, assim como algumas características químicas do extrato de fruto e da folha do P. lingue. As atividades antibacterianas foram determinadas pelo método da inibição do crescimento bacteriano em meio líquido empregando-se bactérias Gram-positivas e Gram-negativas. As linhagens celulares leucêmicas, Kasumi-1 e Jurkat foram usadas para avaliar a atividade citotóxica em ensaios empregando-se iodeto de propídio e AlamarBlue. Foram avaliados os teores totais de fenóis, flavonóides, taninos condensados, alcalóides e lipídeos presentes nos extratos das folhas e dos frutos. As atividades antioxidantes de ambos os extratos também foram avaliadas. O extrato das folhas foi o que apresentou o maior conteúdo de fenóis, taninos condensados e flavonóides totais e a maior atividade antioxidante. Já o extrato de fruto apresentou a maior quantidade de lipídios e alcaloides e a melhor atividade antibacteriana contra Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium e Micrococcus luteus. Já o extrato das folhas apresentou apenas atividade contra M. luteus. Em relação à atividade citotóxica, apenas o extrato do fruto apresentou citotoxicidade contra as linhagens celulares Jurkat e Kasumi-1. Em resumo, o extrato do fruto de P. lingue é uma potencial fonte de moléculas com atividade biológica para o desenvolvimento de novos fármacos a serem utilizados em alguns tipos de leucemia, bem como agente antibacteriano.

Abstract Persea lingue Ness is a tree species that lives mainly in temperate forests of south-central Chile. Its leaves are used in ethnomedicine, the fruit is a drupe similar to that of the avocado and has not been studied. The aim of this study was to determine the cytotoxicity in leukemia cell and antibacterial activity, along with some chemical content characteristics of P. lingue fruit and leaf extracts. The antibacterial activity was determined by the inhibition of bacterial growth in liquid medium assay against Gram-positive and Gram-negative bacteria. The leukemia cell lines Kasumi-1 and Jurkat were used to evaluate the cytotoxic activity by using propidium iodide and AlamarBlue assays. Total phenolic, flavonoid, condensed tannin, alkaloid and lipid contents were evaluated in the fruit and in the leaf extracts. The antioxidant activity of both extracts were also elavaluated. Leaf extract presented the highest content of total phenols, condensed tannins and flavonoids, and also the highest antioxidant activity. While the fruit extract has a higher amount of lipids and alkaloids and the high antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus megaterium and Micrococcus luteus. The leaf extract only showed activity against M. luteus. Concerning the cytotoxic activity, only the fruit extract showed cytotoxicity against the cell lines Jurkat and Kasumi-1. P. lingue fruit extract is a potential source of biologically active molecules for the development of new drugs to be used in some types of leukemia, as well as antibacterial agent.

The aim of this study was to compare P bioavailability in a Nothofagus rainforest Andisol (FS) and an adjacent clear-cut grassland soil (GS) in southern Chile to evaluate the effects of land use change on P chemical forms determined by chemical fractionation and 31P-NMR spectroscopy. Total phosphorus (P), Olsen P, microbial P, different soil P fractions (determined using a modified Hedley procedure), 31P-NMR spectroscopy results, acid phosphatase (P-ase) activity, pH and organic C were analyzed and compared. Forest samples were collected from the mineral soil at a depth of 2-20 cm and were compared with those collected from grassland soil at the same depth. Total P ranged from 2028 mg kg-1 (FS) to 2157 mg kg-1 (GL)and total organic P ranged from 829 mg kg-1 (FS) to 1176 mg kg-1 (GL). On the contrary, Olsen P, microbial P, labile P and P-ase activity were higher in the evergreen forest soil than in the grassland, with the predominance of the moderately labile (NaOH-Po) fraction, which ranged from 668 to 720 mg kg-1 in both soils. Phosphorus was mainly present in monoester-P form in the NMR extract in both soils (67 % on average). Other 31P-NMR signals were identified as C2-myo-inositol phosphate and scyllo-inositol hexakisphosphate. The results suggest that land use change from forest to grassland will reduce P bioavailability and P-ase activity.

An important issue for soil conservation and waste disposal is the use of biosolids in agriculture and for land reclamation. Most biosolids contain valuable nutrients that could be used to improve soil fertility. The aim of this work was to establish the effects of the application of biosolids on some chemical, biological and physical properties in an Andisol from southern Chile. This study was carried out under farm conditions during the wheat (Triticum aestivum) growing cycle. Five land plots of 10 x 4 m each were prepared: control soil (TAT), chemical fertilisation (TAF) and applications equivalent to 30 ton biosolids/ha (TA30), 60 ton biosolids/ ha (TA60) and 90 ton biosolids ha-1 (TA90). The soil samples of both treatment and non-treatment groups were collected after the application of biosolids, after sowing and before the wheat harvest. The evaluated chemical soil parameters were modified by the application of biosolids. Base levels of organic carbon, pH and P increased. Biological activity measured by the evolution of C-CO2 followed the sequence TA90>TA60>TA30>TAF>TAT. The physical properties evaluated, namely water infiltration rate, accumulated infiltration and water retention capacity, all increased with the increasing dose of biosolids. The results show a strong correlation between the biosolids dose applied and the change in the soil properties studied.

Phosphate-solubilising saprophytic fungi have a potential application in plant nutrition; therefore, the aim of this study was 1) to perform a screening and isolation of native phosphofungi from volcanic soils of southern Chile, 2) to select a liquid medium for the evaluation of these phosphofungi and 3) to test a selected phospho fungus as a biofertiliser in a volcanic soil. The phosphofungi were screened using Martin medium (rose bengal-streptomycin agar) with calcium phosphate (Ca3(PO4)2) or calcium phytate as the phosphorus source. Six promising strains (Penicillium sp., Penicillium albidum, Penicillium thomii, Penicillium restrictum, Penicillium frequentans and Gliocladium roseum) were evaluated in the liquid media of Agnihotri, Asea-Wakelin, Pikovskaya and Nahas. The soluble phosphorus, acid phosphatase activity, pH and fungal biomass were determined. In most soils, the greatest proportion of phosphofungi solubilised organic P. The Asea-Wakelin medium appears to be the medium of choice for the quantitative evaluation of phosphofungi isolated from the volcanic soils tested. Penicillium albidum was selected as a potential biofertiliser due to its capacity to solubilise both inorganic and organic P via its specific solubilising activity (64 mg P/g fungus), phosphatase secretion and enhancement of the growth and mineral nutrition of lettuce plants growing in a volcanic soil.

Background: There is a paucity of information about the epidemiology of acute renal failure in Chile. Aim: To perform a prospective multicentric survey of severe acute renal failure in Chile. Material and methods: All patients admitted to ten hospitals in Metropolitan Santiago, during a period of six months with severe acute renal failure, were studied. The criteria for severity was the requirement of renal replacement therapy. All patients information was gathered in special forms and the type of renal replacement therapy and evolution was registeres. Results: One hundred fourteen patients were studied (65 males, age range 18 to 87 years). The calculated incidence of acute renal failure was 1.03 cases per 1000 hospital discharges. The onset was nosocomial in 79 subjects (69%) and community acquired in the rest. Renal failure was oliguric in 64 cases (56%) and in 60% of patients it had two or more causative factors. Sepsis, isolated or combined with other causes, was present in 51 of patients. Other causes included ischemia in 47%, surgery in 26%, exogenous toxicity in 25%, endocenous toxicity in 11%, acute glomerular damage in 6% and obstructive uropathy in 6%. Cardiac surgery was responsible for 47% of post operative cases of acute renal failure. Intermittent conventional hemodialysis, continuous renal replacement techniques and daily prolonged hemodialysis were used in 66%, 29% and 2% of patients, respectively. Overall mortality was 45% and it was higher in oliguric patients. Gender, age, cause or the type of therapy did not influence survival. Nine percent of surviving patients had some degree of kidney dysfunction at discharge. Conclusions: There is still a great space for prevention of severe acute renal failure in Chile, considering the main etiologies found in this study