Novel 2,5-Diketopiperazines with In Vitro Activities against Protozoan Parasites of Tropical Diseases.

Malaria, Chagas disease, and leishmaniasis are tropical diseases caused by protozoan parasites of the genera Plasmodium, Trypanosoma and Leishmania, respectively. These diseases constitute a major burden on public health in several regions worldwide, mainly affecting low-income populations in economically poor countries. Severe side effects of currently available drug treatments and the emergence of resistant parasites need to be addressed by the development of novel drug candidates. Natural 2,5-Diketopiperazines (2,5-DKPs) constitute N-heterocyclic secondary metabolites with a wide range of biological activities of medicinal interest. Its structural and physicochemical properties make the 2,5-DKP ring a versatile, peptide-like, and stable pharmacophore attractive for synthetic drug design. In the present work, twenty-three novel synthetic 2,5-DKPs, previously synthesized through the versatile Ugi multicomponent reaction, were assayed for their anti-protozoal activities against P. falciparum, T. cruzi, and L. infantum. Some of the 2,5-DKPs have shown promising activities against the target protozoans, with inhibitory concentrations (IC50) ranging from 5.4 to 9.5 µg/mL. The most active compounds also show low cytotoxicity (CC50), affording selectivity indices ≥ 15. Results allowed for observing a clear relationship between the substitution pattern at the aromatic rings of the 2,5-DKPs and their corresponding anti-Plasmodium activity. Finally, calculated drug-like properties of the compounds revealed points for further structure optimization of promising drug candidates.

In vitro anti-Leishmania activity of new isomeric cobalt(II)complexes and in silico insights: Mitochondria impairment and apoptosis-like cell death of the parasite.

The synthesis, physico-chemical characterization and in vitro antiproliferative activity against the promastigote form of Leishmania amazonensis of two new cobalt(II) coordination compounds (i.e. [Co(HL1)Cl2]0.4,2H2O (1) and [Co(HL2)(Cl)(CH3OH)](ClO4).2H2O (2)) are reported, where HL1 = 4-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one and HL2 = 7-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one. X-ray diffraction studies were performed for complex (2) and the structure of complex (1) was built through Density Functional Theory (DFT) calculations. Complex (1) presented no cytotoxicity to LLC-MK2, but complex (2) was toxic. IC50 against promastigotes of L. amazonensis for complex (1) were 4.90 (24 h), 3.50 (48 h) and 3. 80 µmol L-1 (72 h), and for complex (2) were 2.09, 4.20 and 2.80 µmol L-1, respectively. Due to the high toxicity presented by complex (2) against LLC-MK2 host cells, mechanistic studies, to shed light on the probable mode of leishmanicidal activity, were carried out only for the non-cytotoxic complex. Complex (1) was able to elevate mitochondrial membrane potential of the parasites after treatment. Transmission electron microscopy revealed typical apoptotic condensation of chromatin, altered kinetoplast and mitochondria structures, suggesting that apoptosis-like cell death of the protozoa is probably mediated by an apoptotic mechanism associated with mitochondrial dysfunction (intrinsic pathway). Molecular docking studies with complex (1) upon protein tyrosine phosphatase (LmPRL-1) suggests a plausible positive complex anchoring mainly by hydrophobic and hydrogen bond forces close to the enzyme's catalytic site. These promising results for complex 1 will prompt future investigations against amastigote form of L. amazonensis.

Effect of water-soluble polymers, polyethylene glycol and poly(vinylpyrrolidone), on the gelation of aqueous micellar solutions of Pluronic copolymer F127.

The micellization of F127 (E(98)P(67)E(98)) in dilute aqueous solutions of polyethylene glycol (PEG6000 and PEG35000) and poly(vinylpyrrolidone) (PVP K30 and PVP K90) is studied. The average hydrodynamic radius (r(h,app)) obtained from the dynamic light scattering technique increased with increase in PEG concentration but decreased on addition of PVP, results which are consistent with interaction of the micelles with PEG and the formation of micelles clusters, but no such interaction occurs with PVP. Tube inversion was used to determine the onset of gelation. The critical concentration of F127 for gelation increased on addition of PEG and of PVP K30 but decreased on addition of PVP K90. Small-angle X-ray scattering (SAXS) was used to show that the 30 wt% F127 gel structure (fcc) was independent of polymer type and concentration, as was the d-spacing and so the micelle hard-sphere radius. The maximum elastic modulus (G(max)(')) of 30 wt% F127 decreased from its value for water alone as PEG was added, but was little changed by adding PVP. These results are consistent with the packed-micelles in the 30 wt% F127 gel being effectively isolated from the polymer solution on the microscale while, especially for the PEG, being mixed on the macroscale.

The effect of polymeric additives on the solubilisation of a poorly-soluble drug in micellar solutions of Pluronic F127.

The solubilisation of griseofulvin in 1wt% aqueous micellar solutions of Pluronic F127 at 37°C has been modified by adding polyethylene glycol PEG 35000 or poly(vinylpyrrolidone) PVP K30. The solubilisation capacity expressed in terms of unit weight of F127 is increased by the addition of 0.5wt% PEG 35000 to a value approaching double that of a 2.5wt% solution of F127 alone, but there is no advantage in adding 0.5wt% PVP K30.

The effect of n-, s- and t-butanol on the micellization and gelation of Pluronic P123 in aqueous solution.

In dilute aqueous solution unimers of copolymer P123 (E(21)P(67)E(21)) associate to form micelles, and in more concentrated solution micelles pack to form high-modulus gels. We are interested in the use of the system as a templating agent in the synthesis of mesoporous materials, and the possibility of determining gel structure, hence mesoporosity, by use of n-, s- or t-butanol. Dynamic light scattering from clear dilute solutions has been used to confirm micellization, visual observation of mobility (tube inversion) to detect gel formation in concentrated solutions, oscillatory rheometry to confirm gel formation and provide values of elastic moduli over a wide temperature range, and small-angle X-ray scattering to determine gel structure. As expected, clear cubic gels (fcc) formed at moderate concentrations and temperatures, e.g. 30 wt.% P123, 20°C, and clear hexagonal gels at higher concentrations and temperatures. The transition on heating from cubic to hexagonal gel involved an intermediate turbid phase in which cubic and hex structures coexisted. Considering cubic gels of 35 wt.% P123 in 5 wt.% butanol/water, those in n-butanol/water had the lowest critical temperatures for gel formation and the highest maximum values for the dynamic elastic modulus (G') of the gels, a result consistent with n-butanol/water being the poorest solvent for P123.

Effect of ethanol on the micellization and gelation of pluronic p123.

In certain applications copolymer P123 (E21P67E21) is dissolved in water-ethanol mixtures, initially to form micellar solutions and eventually to gel. For P123 in 10, 20, and 30 wt % aqueous ethanol we used dynamic light scattering from dilute solutions to confirm micellization, oscillatory rheometry, and visual observation of mobility (tube inversion) to determine gel formation in concentrated solutions and small-angle X-ray scattering (SAXS) to determine gel structure. Except for solutions in 30 wt % aqueous ethanol, a clear-turbid transition was encountered on heating dilute and concentrated micellar solutions alike, and as for solutions in water alone (Chaibundit et al. Langmuir 2007, 23, 9229) this could be ascribed to formation of wormlike micelles. Dense clouding, typical of phase separation, was observed at higher temperatures. Regions of isotropic and birefringent gel were defined for concentrated solutions and shown (by SAXS) to have cubic (fcc and hcp) and hexagonal structures, consistent with packed spherical and elongated micelles, respectively. The cubic gels (0, 10, and 20 wt % ethanol) were clear, while the hex gels were either turbid (0 and 10 wt % ethanol), turbid enclosing a clear region (20 wt % ethanol), or entirely clear (30 wt % ethanol). The SAXS profile was unchanged between turbid and clear regions of the 20 wt % ethanol gel. Temperature scans of dynamic moduli showed (as expected) a clear distinction between high-modulus cubic gels (G'max approximately 20-30 kPa) and lower modulus hex gels (G'max<10 kPa).

Micellization and gelation of mixed copolymers P123 and F127 in aqueous solution.

The micellization in dilute aqueous solution of Pluronic copolymers P123 (E21P67E21) and F127 (E98P67E98) and mixtures of the two was investigated using static and dynamic light scattering. Gelation of concentrated solutions of the two copolymers and their mixtures was studied using tube inversion and oscillatory rheometry. The two copolymers comicellized to give micelles with narrow size distributions. Clouding temperatures and critical micelle temperatures decreased as the proportion of P123 in the mixture was increased. Micelle association numbers of the mixed micelles lay between the values found for micelles of P123 and F127 alone, whereas micelle radii passed through maximum values in the range 0-50 wt % P123. As judged by the ratio of the thermodynamic to the hydrodynamic radius, the micelle interaction potential changes gradually from soft to hard as the proportion of P123 in the mixture is increased. Regions of cubic and hexagonal (birefringent) gel were defined for concentrated solutions. The high-temperature boundary of the 30 wt % cubic gel decreased monotonically from 90 to 43 degrees C as the proportion of P123 in the mixture was increased from 0 to 100 wt %, whereas the low-temperature boundary was essentially constant at 15 +/- 3 degrees C. Increasing the proportion of P123 in the mixture at 25 degrees C increased the concentration at which the cubic gel was first formed and decreased the concentration at which the hexagonal gel was first formed.

Mixtures of triblock copolymers E(62)P(39)E(62) and E(137)S(18)E(137) potential for drug delivery from in situ gelling micellar formulations.

The gelation behaviour of concentrated micellar solutions of mixtures of a block copolymer of ethylene oxide and styrene oxide (E(137)S(18)E(137)) with one of ethylene oxide and propylene oxide (E(62)P(39)E(62)) has been investigated. Over a wide range of compositions, up to 90 wt.% E(137)S(18)E(137) in the mixture, gelation resembled that of solutions of E(62)P(39)E(62) alone, i.e. they gelled on heating from ambient to body temperature. In related experiments, using the aromatic drug griseofulvin as a comparative standard, it was demonstrated that solubilisation efficiency of dilute micellar solutions of the mixtures with 80 wt.% or more E(137)S(18)E(137) approached that of solutions of E(137)S(18)E(137) alone. Thus it was shown that the mixed system could have both the satisfactory solubilisation capacity of micellar solutions of E(137)S(18)E(137) and the desirable gelation characteristics of E(62)P(39)E(62), and so have potential for use in drug release applications involving in situ gelation.

Computação na apresentação e análise do EEG digital e quantitativo / Digital and quantitative EEG computer presentation and analysis

A introdução do registro computadorizado do EEG (EEG digital) e evolução dos computadores, seus programas e aplicativos facilitam a análise sistemática dos dados (EEG quantitativo). As suas principais vantagens são: percepção de padrões não detectados na análise visual; economia de papel; modificações da sensibilidade, filtros, montagens, velocidade, número de canais após a realização do exame e análise estatística dos dados. O principal objetivo deste trabalho é demonstrar os princípios básicos para realização, análise, assim como a construção de modos de apresentação dos resultados (mapas cerebrais, histogramas tabelas numéricas) dos EEGs digital e quantitativo, permitindo seu emprego nas epilepsias, demências, doenças cerebrovasculares, traumatismos cranianos, doenças psiquiátricas e na monitorização dos pacientes comatosos e dos internados em centros de tratamento intensivo.

Evoluçäo da esquistossomose na Zona da Mata Sul de Pernambuco. Epidemiologia e situaçäo atual: controle ou descontrole? / Evolution of schistosomiasis endemicity in the Zona da Mata Sul, Pernambuco State, Brazil. Epidemiology and current situation: under control or out of control?

Em busca de compreender a situaçäo atual da esquistossomose na Zona da Mata Sul de Pernambuco, área de plantio e de produçäo de açúcar e álcool, contempla as seguintes fases: origem, evoluçäo e determinantes básicos deste processo de saúde e doença (historicidade e temporalidade), centrados na epidemiologia moderna e no conhecimento crítico dos abrangentes programas estatais de intervençäo realizados nesta área a partir de 1970, e, por último, a situaçäo atual, avaliada por meio de um estudo de caso, realizado em 17 municípios, compreendendo 1.424 localidades e populaçäo de 485.200 habitantes, com índices de prevalência que a tornam a segunda área endêmica do País. Com base na análise dos resultados dos programas, através de séries temporais, compreeendendo 14 anos, pode-se chegar às seguintes conclusöes: a) os índices atuais de positividade nos municípios/localidades säo mais elevados do que os observados no início da década de 80; b) a estratégia fundamental dos programas estava centrada, quase que exclusivamente, no tratamento em massa da populaçäo, determinando posterior reinfestaçäo e surgimento de novos casos; c) propostas como a de descentralizaçäo/municipalizaçäo contidas no PCDEN (Programa de Controle das Doenças Endêmicas no Nordeste), na década de 90, näo foram implantadas de forma efetiva, mantendo-se uma situaçäo de näo-controle dessa secular endemia.

A expansão e o desafio secular de controlar a endemia esquistossomótica em Pernambuco: centralização e verticalidade das ações / The Spreading of schstosomosis enodemic in the state of Pernambuco

Este estudo identifica determinantes hitóricos da expansão esquistossomótica em Pernambuco, centrando-se no último programa abrangente (PDCEN) implantado no Nordeste (iniciado em 1990 e concluído em 1996), apresentando e conentando suas principais diretrizes e objetivos. Realiza-se um estudo de caso em Amaraji, município da Zona da Mata Sul de Pernambuco, região de platio e produção de açúcar, comparando-se a sede do município e o distrito de Demarcação. Os resultados permitem as seguintes conclusões: A situação atual indica incremento da endemia esquistossomótica na Zona da Mata Sul de Pernambuco; O perfil epidemiológico verificado comprova as precárias condições de vida e trabalho existentes: O processo de implantação do PCDEN mantém as características fundamentais dos programas anteriores, ou seja, centralização e verticalidade das ações, privilegiando ações de tratamento em massa , afetando sua eficácia e comprometendo os objetivos e metas de redução da prevalência

1552 amniocentesis: indicaciones y resultados / 1522 amniocentesis: indications and results

Se presentan las indicaciones y resultados de 1552 amniocentesis realizadas entre 1987 y 1992 en nuestro servicio de fisiopatología fetal. La indicación más frecuente es la edad materna avanzada (35 años) que supone un 61.40 por ciento de los casos. La mayoría de las amniocentesis se realizaron entre 14-16 semanas de gestación. Se encontraron 41 anomalias cromosómicas (2.64 por ciento): 32 aneuploidías y nueve alteraciones estructurales. Entre las aneuploidías destacan por orden de frecuencia, 15 casos de trisomía 21 y nueve casos de trisomía 18. Los grupos con mayor riesgo de alteración cromosómica son los portadores de translocación cromosómicas (91,23 por ciento) y el grupo de sospecha ecográfica de malformación (10,75 por ciento). El análisis citogenético resultó posible en el 95,74 por ciento de los casos. La tasa de fracasos de cultivo en 1992 resultó ser del 2,50 por ciento (AU)

1552 amniocentesis: indicaciones y resultados / 1522 amniocentesis: indications and results

Se presentan las indicaciones y resultados de 1552 amniocentesis realizadas entre 1987 y 1992 en nuestro servicio de fisiopatología fetal. La indicación más frecuente es la edad materna avanzada (35 años) que supone un 61.40 por ciento de los casos. La mayoría de las amniocentesis se realizaron entre 14-16 semanas de gestación. Se encontraron 41 anomalias cromosómicas (2.64 por ciento): 32 aneuploidías y nueve alteraciones estructurales. Entre las aneuploidías destacan por orden de frecuencia, 15 casos de trisomía 21 y nueve casos de trisomía 18. Los grupos con mayor riesgo de alteración cromosómica son los portadores de translocación cromosómicas (91,23 por ciento) y el grupo de sospecha ecográfica de malformación (10,75 por ciento). El análisis citogenético resultó posible en el 95,74 por ciento de los casos. La tasa de fracasos de cultivo en 1992 resultó ser del 2,50 por ciento

Observations on the morphology of mycobacterium leprae by ordinary optics, phase microscopy, and electron microscopy

Mycobacterium leprae has been studied with the aid of the ordinary and phase microscopes, and the electron microscope. It has been found that treatment of M. leprae with distilled water or chloroform prior to examination produces artefacts. Fixation of material is the vapor of 2 per cent osmic acid solution gives the best results for the electron microscope study of the bacillus. The following forms representing the morphological variants of this mycobacterium have been established with certainty from this study: (a) a short, oval type of cells with one or two polar condensations; (b) elongate types with double polar condensations; (c) very long types with alternate light and dark zones; and (d) homogeneously dark, elongate types. The possible significance and relationships of these variants have been discussed.