Lipid-based nanoformulations of trifluralin analogs in the management of Leishmania infantum infections

Aim: To improve the potential of trifluralin (TFL) in the management of Leishmania infantum infections through the synthesis of analogs (TFLA) and incorporation in nanoparticulate drug delivery systems (NanoDDS), liposomes and solid lipid nanoparticles, for selective targeting to leishmania infection sites. Material & methods: In vitro screening of 18 TFLA was performed by flow cytometry. NanoDDS were loaded with active TFLA and evaluated for antileishmanial efficacy in mice through determination of parasite burden in liver and spleen. Results: The in vitro testing revealed the most active and nontoxic TFLAs, which were selected for the in vivo studies based on high incorporation in liposomes and lipid nanoparticles (>90%). Selected TFLA nanoformulations showed superior antileishmanial activity in mice (parasite burden >80%), over free TFLA and Glucantime. Conclusion: The modification of TFL structure to obtain active TFLA, together with their incorporation in NanoDDS, improved their in vivo performance against L. infantum infection.

Evaluation of the growth-inhibitory effect of trifluralin analogues on in vitro cultured Babesia bovis parasites

Bovine babesiosis, caused by Babesia bovis, is a global tick borne hemoprotozoan parasite disease characterized by fever, anemia, weight losses and ultimately death. Several babesicidal drugs that have been in use in cattle for years have proven to be only partially effective and the development of alternative chemotherapeutics that are highly specific and have low toxicity against babesiosis is needed. Trifluralin derivatives specifically bind alpha-tubulin in plants and protozoa parasites causing growth inhibition. A set of 12 trifluralin analogues (TFLA) has previously been shown to be inhibitory for the growth of Leishmania species. The conservation of several key amino acids involved in the trifluralin binding site of alpha-tubulin among Leishmania sp. and B. bovis provides rationale for testing these compounds also as babesiacides. The previously tested Leishmania inhibitory, TFLA 1-12 minus TFLA 5, in addition to three novel TFLA (termed TFLA 13-15), were tested against in vitro cultured B. bovis parasites. While all of the TFLA tested in the study showed inhibition of B. bovis growth in vitro TFLA 7, TFLA 10 and TFLA 13, were the most effective inhibitors with estimated IC50 (μM) at 72 h of 8.5 ± 0.3; 9.2 ± 0.2; 8.9 ± 0.7, respectively for the biologically attenuated cloned B. bovis Mo7 strain, and 13.6 ± 1.5; 18.7 ± 1.6; 10.6 ± 1.9, respectively for the virulent B. bovis T3Bo strain. The differences found between the two strains were not statistically significant. Importantly, these drugs displayed low levels of toxicity for the host erythrocytes and bovine renal arterial endothelial cells at the doses tested. The demonstrated ability of trifluralin analogues to inhibit in vitro growth of B. bovis parasites combined with their low toxicity for host cells suggests that these compounds may be further developed as novel alternatives for the treatment of bovine babesiosis.

Fluorescence Characteristics of Some Dehydroabietic Acid-Based Arylamines

Absorption spectra and fluorescence data in nonpolar solvents are reported for seven novel dehydroabietic acid-based diarylamines, which have potential as components of hole transport layers for molecular electronic devices. This bulky group has been found to improve the possibilities for film formation of these compounds, and in this study we show that this does not significantly affect their fluorescence characteristics, which are similar to diphenylamine.

Fluorescence Study of Dehydroabietic Acid-Based Bipolar Arylamine-Quinoxalines

The absorption and fluorescence spectra, lifetimes and quantum yields of a series of triarylaminequinoxaline bipolar compounds, with and without the bulky dehydroabietic acid group, have been studied in toluene solution. This bulky group is introduced to improve solubility and thermal properties of these systems. It is shown that this does not affect their spectral or photophysical behavior. The compounds show relatively strong fluorescence, with the emission maximum strongly dependent upon the substituents present. Oxidation potentials have also been determined in acetonitrile solution, and again indicate that introduction of the resin acid moiety has no effect on these properties.

New silica-immobilized hydroxypyrimidinone as sorbent of hard metal ions from aqueous fluids

The chemical modification of solid supports with chelators for the sorption of residual amounts of specific metal ions is of environmental and biological current interest. The present work describes the preparation and chelating properties of a new hydroxypyrimidinone-functionalized silica, (HOPY-PrN)-Si, with high affinity for hard metal ions. The new chelating matrix was obtained by coupling a 1-hydroxy-2-(1H)-pyrimidinone derivative, HOPY-PrN, to an epoxy-activated silica. It showed good stability at neutral and acidic conditions and high sequestering capacity for hard metal ions, namely Fe3+ and Al3+, as previously found for the corresponding sepharosic derivative. However, the fact that the present silica-gel derivative is considerably less expensive gives support to its potential interest as a sorbent of traces of toxic hard metal ions from water streams or even from physiological fluids, aided by extracorporeal devices containing the immobilized chelator.

[AIDS epidemic dynamics in the municipality of Rio de Janeiro, Brazil, 1988-1996: Spatial-temporal statistic modeling]

This study uses a spatial-temporal model to analyze the spatial spread of the AIDS epidemic (adult cases) in the municipality of Rio de Janeiro, Brazil, during three periods: 1988-1990, 1991-1993, and 1994-1996. City districts were used as the geographic units of analysis. A spatial analysis was also performed for pediatric AIDS cases due to vertical HIV transmission, according to period of birth, 1985-90 and 1991-96. For total adult AIDS cases, the initial period was characterized by a polygonal cluster located around the harbor area, which expanded from west to east. Among homosexual cases, in situ growth predominated, and a decrease in the intensity of the diffusion process was observed from the second to the final period. Among heterosexual cases, the epidemic displayed a relevant geographic spread, mainly from 1988-1990 to 1991-1993. Among female cases in the final time period, a cluster of high incidence rates was found towards the northwest, including very poor areas. Among pediatric cases in 1991-1996, a significant correlation was found between AIDS incidence rates and poverty levels in the respective municipal districts. The results suggest that a more complete understanding of AIDS spatial-temporal dynamics can make a major contribution to preventive measures.

Synthetic derivatives of abietic acid with radical scavenging activity

In this work, studies on the arylation of anilines derived from dehydroabietic acid, the main component of disproportionated rosin, are presented. The redox properties of the new diarylamines were investigated by cyclic voltammetry, and their free radical scavenging activity was tested by reduction of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Three of the diarylamines with lower oxidation potential proved to be as active as isopropyldiphenylamine (IPPD) and superior to tert-butylhydroxytoluene (BHT), both commercially available synthetic antioxidants.

The influence of climatic variability on the quality of wine

In this paper, the quality of the wine from the Dão (Viseu) region of Portugal is examined and relationships between wine quality and climatic variability are obtained using spectral and correlation analysis to determine the structure of the temporal variations. The spectra of the series of quality of wine values show statistically significant oscillations coherent with those found in the series of teleconnection indices. The series cover a period of 33 years. A significant correlation was obtained between wine quality and minimum air temperature in May, December and total precipitation in April. The teleconnection circulation indices are used to provide some physical insight into the most significant oscillating components of the climatic and the wine quality series. We found significant and positive correlations between the quality of the wine and the Southern Oscillation Index (SOI) of August and negative with the SOI of January and with the North Atlantic Oscillation of April. Wine quality and climatic series can be predicted using statistical models depending on significant oscillations.

[The spread of the AIDS epidemic in Brazil from 1987 to 1996: a spatial analysis]

Mean AIDS incidence rates were calculated for three time periods, 1987-89, 1990-92, and 1993-96, using reported adult AIDS cases by county. The analysis included the following variables: "population of counties for resident AIDS cases"; "proportion of population residing in urban areas", and "concentration of poverty", stratifying by gender and exposure categories. The Southeast region has experienced the lowest increase, contrasting with the steep rise observed in the North and South between the second and third study periods. Comparing variations in incidence rates from 1990-92 and 1993-96 by region or population, the greatest increase was among women. In the larger cities, AIDS cases among "homo/bisexual men" predominate, although the proportion of cases among men who have sex with men has decreased as heterosexual cases have undergone a continuous increase. IDUs have been the core stratum in medium-sized counties. For the smallest counties, heterosexual transmission has been the basic element in local dynamics. Even though AIDS is still an urban phenomenon in Brazil, the epidemic is spreading to rural counties. Until recently it has mainly affecting relatively more affluent areas, but there is now an evident spread of the epidemic to poorer areas.

Health conditions and residential concentration of poverty: a study in Rio de Janeiro, Brazil

STUDY OBJECTIVES

To establish the geographical relation of health conditions to socioeconomic status in the city of Rio de Janeiro, Brazil.

DESIGN

All reported deaths in the municipality of Rio de Janeiro, from 1987 to 1995, obtained from the Mortality Information System, were considered in the study. The 24 "administrative regions" that compose the city were used as the geographical units. A geographical information system (GIS) was used to link mortality data and population census data, and allowed the authors to establish the geographical pattern of the health indicators considered in this study: "infant mortality rate"; "standardised mortality rate"; "life expectancy" and "homicide rate". Information on location of low income communities (slums) was also provided by the GIS. A varimax rotation principal component analysis combined information on socioeconomic conditions and provided a two dimension basis to assess contextual variation.

MAIN RESULTS

The 24 administrative regions were aggregated into three different clusters, identified as relevant to reflect the socioeconomic variation. Almost all health indicator thematic maps showed the same socioeconomic stratification pattern. The worst health situation was found in the cluster composed of the harbour area and northern vicinity, precisely in the sector where the highest concentration of slum residents are present. This sector of the city exhibited an extremely high homicide rate and a seven year lower life expectancy than the remainder of the city. The sector that concentrates affluence, composed of the geographical units located along the coast, showed the best health situation. Intermediate health conditions were found in the west area, which also has poor living standards but low concentration of slums.

CONCLUSIONS

The findings suggest that social and organisation characteristics of low income communities may have a relevant role in understanding health variations. Local health and other social programmes specifically targeting these communities are recommended.

[Income inequality and health: the case of Rio de Janeiro]

This ecological analysis addresses the association between income inequality and health status in the municipality of Rio de Janeiro. Data were analyzed using geo-processing and multiple regression techniques. The following health indicators were used: infant mortality rate; standardized mortality rate; life expectancy at birth; and homicide rate among 15-29-year-old males. Patterns of income inequality were assessed through income distribution indicators: Gini index, Robin Hood index, and top 10 %/bottom 40% average income ratio. The results indicate significant correlations between income distribution indicators and health indicators, providing additional empirical evidence of the association between health status and income inequality. For the homicide rate, the effect of the indicator "density of slum residents" was also relevant, suggesting that further deterioration in health standards may be due to social disruption of deprived communities and the resultant increase in criminal activity. The geo-epidemiological analysis presented here highlights the association between adverse health outcomes and residential concentration of poverty. Social policies focused on slum residents are needed to reduce the harmful effects of relative deprivation.