In silico models for predicting vector control chemicals targeting Aedes aegypti.

Human arboviral diseases have emerged or re-emerged in numerous countries worldwide due to a number of factors including the lack of progress in vaccine development, lack of drugs, insecticide resistance in mosquitoes, climate changes, societal behaviours, and economical constraints. Thus, Aedes aegypti is the main vector of the yellow fever and dengue fever flaviviruses and is also responsible for several recent outbreaks of the chikungunya alphavirus. As for the other mosquito species, the A. aegypti control relies heavily on the use of insecticides. However, because of increasing resistance to the different families of insecticides, reduction of Aedes populations is becoming increasingly difficult. Despite the unquestionable utility of insecticides in fighting mosquito populations, there are very few new insecticides developed and commercialized for vector control. This is because the high cost of the discovery of an insecticide is not counterbalanced by the 'low profitability' of the vector control market. Fortunately, the use of quantitative structure-activity relationship (QSAR) modelling allows the reduction of time and cost in the discovery of new chemical structures potentially active against mosquitoes. In this context, the goal of the present study was to review all the existing QSAR models on A. aegypti. The homology and pharmacophore models were also reviewed. Specific attention was paid to show the variety of targets investigated in Aedes in relation to the physiology and ecology of the mosquito as well as the diversity of the chemical structures which have been proposed, encompassing man-made and natural substances.

[Sex-hormone binding globulin (SHBG) levels during pregnancy as predictors for pre-eclampsia and fetal growth restriction]. / Evaluación de la globulina transportadora de hormonas esteroidales (SHBG) durante el embarazo como factor predictor de pre-eclampsia y restricción del crecimiento intrauterino.

BACKGROUND: Sex-Hormone Binding Globulin (SHBG) may be associated to Pre-eclampsia (PE) and Fetal Growth Restriction (RCIU). AIM: To determine if maternal serum SHBG concentrations during the first and second trimesters are predictive biomarkers of Pre-eclampsia and RCIU. PATIENTS AND METHODS: Prospective cohort study carried out in the Fetal Medicine Unit, Universidad de Chile Clinical Hospital between January, 2005 and December, 2006. Blood samples were obtained from unselected pregnant women during routine 11-14 week and 22-25 week ultrasound examinations, conforming two different study groups. Posteriorly, serum SHBG concentrations were determined in women who developed Pre-eclampsia, RCIU and their respective controls. RESULTS: Fifty five patients were included in the 11-14 weeks group. Nine women that developed PE, 10 that developed RCIU and 36 controls were selected from this group. There were no significant differences in SHBG levels between patients with PE, RCIU or controls (324.7 (26.6), 336.8 (33.9) and 377.5 (24.3) nmol/L, respectively). Fifty four women were included in the 22-25 weeks group. Eight women who developed Pre-eclampsia, 15 who developed RCIU and 31 controls were selected. Again, there were no significant differences in SHBG levels between patients with PE, RCIU or controls (345.5 (151.1), 383.8 (143.4) and 345.5 nmol/l (151.1), respectively). CONCLUSIONS: Maternal SHBG serum levels did not predict subsequent development of Pre-eclampsia and RCIU.

Evaluación de la globulina transportadora de hormonas esteroidales (SHBG) durante el embarazo como factor predictor de pre-eclampsia y restricción del crecimiento intrauterino / Sex-hormone binding globulin (SHBG) levels during pregnancy as predictors for pre-eclampsia and fetal growth restriction

Background: Sex-Hormone Binding Globulin (SHBG) may be associated to Pre-eclampsia (PE) and Fetal Growth Restriction (RCIU). Aim: To determine if maternal serum SHBG concentrations during the first and second trimesters are predictive biomarkers of Pre-eclampsia and RCIU. Patients and Methods: Prospective cohort study carried out in the Fetal Medicine Unit, Universidad de Chile Clinical Hospital between January, 2005 and December, 2006. Blood samples were obtained from unselectedpregnant women during routine 11-14 week and 22-25 week ultrasound examinations, conforming two different study groups. Posteriorly, serum SHBG concentrations were determined in women who developed Pre-eclampsia, RCIU and their respective controls. Results: Fifty five patients were included in the 11-14 weeks group. Nine women that developed PE, 10 that developed RCIU and 36 controls were selected from this group. There were no significant differences in SHBG levels between patients with PE, RCIU or controls (324.7 (26.6), 336.8 (33.9) and 377.5 (24.3) nmol/L, respectively). Fifty four women were included in the 22-25 weeks group. Eight women who developed Pre-eclampsia, 15 who developed RCIU and 31 controls were selected. Again, there were no significant differences in SHBG levels between patients with PE, RCIU or controls (345.5 (151.1), 383.8 (143.4) and 345.5 nmol/l (151.1), respectively). Conclusions: Maternal SHBG serum levels did not predict subsequent development of Pre-eclampsia and RCIU.

VIH/SIDA: comportamiento epidemiológico de la transmisión vertical en el contexto general de la infección en Chile / HIV/AIDS: epidemiological behavior of vertical transmission in the general context of infection in Chile

ANTECEDENTES: En embarazadas seropositivas sin profilaxis antirretroviral la transmisión vertical (TV) del VIH es de 30%, cifra que disminuye bajo al 2% con un manejo integral de prevención. OBJETIVO: Conocer el comportamiento epidemiológico de la TV en Chile desde la creación del programa nacional de prevención. MÉTODO: Datos aportados por el Departamento de Epidemiología del MINSAL y CONASIDA (1984-2006). Estudió de situación VIH/SIDA por año, regiones, grupo etario y sexo, con especial énfasis en TV. RESULTADOS: Se notificaron 9.317 casos de VIH y 7.886 casos de SIDA (1984-2006), prevalencia en aumento hasta el 2003 con tendencia descendente posteriormente. La razón actual de VIH entre hombres y mujeres es de 4:1, con clara tendencia al aumento de notificación en mujeres. La principal vía de exposición sigue siendo la vía sexual (93,4%). El grupo más afectado está entre los 20-39 años (73,1% para VIH y 63,1% para SIDA), cabe destacar que entre 0-9 años se encuentra el 1,1% de los afectados por VIH y el 1,4% por SIDA, todos infectados por TV. CONCLUSIONES: La transmisión vertical de VIH en Chile es responsable de un bajo porcentaje de las personas notificadas de VIH/SIDA, pero es la causa de la totalidad de los niños afectados por la infección en nuestro país. Se observa una importante reducción de la TV, llegando a niveles muy cercanos a los objetivos ministeriales.

BACKGROUND: The risk of transmitting HIV from mother to unborn child, without any antiretroviral prophylaxis, reaches 30%. It can be reduced to less than 2% by implementing integral preventive strategies. OBJECTIVE: To assess the epidemiological profile of HIV vertical transmission in Chile since the implementation of the national AIDS transmission prevention program. METHOD: Data from the Epidemiology Department of the Health Ministry and the National Commission for AIDS grouped by year, location, ageandgender. Withspecial emphasis on vertical transmission. RESULTS: 9317 cases of HIV infection and 7886 cases of AIDS have been reported in Chile (1984-2006), with a decreasing tendency since 2003. Sexual exposure continues to be the primary route with 93.4% of the cases. The male/female ratio for case notif¡cation is 4:1, with a rising tendency among women. The most affected is between 20-39 years old (73% HIV notification and 63.1% for AIDS). Among children between 0-9 years of age is 1.1% of the HIV and 1.4% of AIDS notifications, all of them for vertical transmission. CONCLUSIONS: HIV vertical transmission in Chile is responsible for a small percentage of HIV/AIDS notifications, but it accounts for all of the infected children. There's been an important reduction in this transmission route, reaching prevalence close to the aimed rates, which can explained by the expanding prevention programs of the health policies implemented by the Health Ministry.

Hepatitis aguda viral durante el embarazo / Acute viral hepatitis during pregnancy

Acute hepatitis has a very low incidence disease during pregnancy. However, it may be an important cause of jaundice during gestation which in cases of viral etiology can have a very high morbidity and mortality risk to the mother and the fetus. The purpose of this review is to update the available knowledge regarding viral hepatitis during pregnancy including description of the main etiologies, transmission route, maternal-fetal risk and possible management.

La hepatitis aguda es una enfermedad de baja incidencia durante el embarazo; sin embargo, es una causa importante de ictericia durante el desarrollo de éste y en algunos casos presenta un alto riesgo de morbi-mortalidad materno-fetal, siendo la etiología principalmente viral. El propósito de este artículo es actualizar los conocimientos disponibles en la literatura médica respecto a hepatitis viral durante el embarazo, conocer cuáles son los agentes más prevalentes, vía de transmisión, riesgo para el binomio madre- hijo y eventual manejo.

[Acute viral hepatitis during pregnancy]. / Hepatitis aguda viral durante el embarazo.

Acute hepatitis has a very low incidence disease during pregnancy. However, it may be an important cause of jaundice during gestation which in cases of viral etiology can have a very high morbidity and mortality risk to the mother and the fetus. The purpose of this review is to update the available knowledge regarding viral hepatitis during pregnancy including description of the main etiologies, transmission route, maternal-fetal risk and possible management.

Reactivity at the interface of chiral amphiphilic dendrimers. High asymmetric reduction by NaBH(4) of various prochiral ketones.

New amphiphilic dendrimers derived from PAMAM and D-gluconolactone were found to induce chirality in the reduction of prochiral ketones by NaBH(4), in heterogeneous (THF) and homogeneous (water) conditions. The third generation of these amphiphilic dendrimers, G(3)G, was found to be a good chiral ligand for the reduction of various prochiral ketones in heterogeneous conditions. Even with substrates well-known to give poor results (especially linear ketones), good enantioselectivities were obtained. It is also important to notice that under heterogeneous conditions (THF) the dendrimer could be recovered by filtration, regenerated, and recycled (up to 10 times), leading to reproducible results in asymmetric reduction of ketones. We have also discussed the reduction of acetophenone in water. Evidence is presented that the selectivity is dominated by the architecture of the dendrimer and some supramolecular ordering in the position of the ketone at the chiral solvating interface. The results obtained showed a correlation between stereoselectivity of the reduction and the compact character of the dendritic particles.

Aggregation Behavior in Aqueous Solutions of a New Class of Asymmetric Bipolar Amphiphiles Investigated by Surface Tension Measurements.

Two series of amphiphilic derivatives of lactose have been synthesized. Tensiometric investigations of the critical micellar concentration (CMC) and the area per molecule at interface (calculated by the Gibbs equation) of aqueous solutions were performed. The values measured depend on the number of methylene groups of the alkyl spacer n and that of the side chain m as well as on the ionic strength and temperature. The results show a behavior closely related to that of gemini surfactants: (1) self-assembly phenomena occur at concentrations below 1 mM, (2) at constant n log CMC increases linearly with higher m, and (3) the influence of the temperature on the aggregation phenomenon is comparable. Copyright 2001 Academic Press.

Chiral aggregates and asymmetric induction of the reduction of prochiral ketones.

The aim of this work was to establish structure-reactivity relationships between chiral aggregates (micelles, vesicles, and "pseudo-micelles" of amphiphilic dendrimers) and asymmetric induction. In water, micelles or vesicles formed with sugar-headed surfactants gave less than 10% ee in the reduction of prochiral ketones by NaBH(4), in contrast with dendrimers bearing the same types of sugar moieties, which gave more than 50% ee under the same reaction conditions. Moreover, in the presence of neoglycodendrimers in THF we have been able to improve reduction of prochiral ketones to give very high stereoselectivity, near 100% in many cases. Comparison of these results suggests that to improve high stereoselectivity it is necessary to work with rigid, well-organized colloidal objects. Copyright 2000 Wiley-Liss, Inc.

Synthetic neoglycolipids for biological applications: correlation between their structures and their interactions with membrane proteins.

Synthetic glycolipids are of interest for their biological applications requiring interactions with membrane proteins. Depending on their structures, new series of glycolipids have applications in extraction of membrane proteins or medical applications as mimics of natural ligands of proteins.

[Synthesis of multifunctional surfactants for elaboration of micellar model systems of enzymes]. / Synthèse de tensioactifs plurifonctionnels pour l'élaboration de systèmes micellaires modèles d'enzymes.

In order to provide a closer analogy between micelles and enzymes, the design of functionalized micellar systems have been undertaken. This paper presents the synthesis of surfactant cationic molecules which contains either a free or a protected aldehyde group. An ammonium quaternary surfactant with two functional groups, aldehyde dimethyl acetal and imidazole, has also been synthesized.

[Demographic dynamics, migrants from bordering countries and economic activity in Buenos Aires]. / Dinamica demografica, migracion limitrofe y actividad economica en Buenos Aires.

PIP: The growth and changes--by age, sex, and place of birth--in the structure of the total population of the Buenos Aires metropolitan area and of the subpopulation over 15 years of age and economically active are analyzed for the decade of the 1980s. Study of the economic participation of migrants and its possible influence on levels of employment or unemployment should be carried out within the framework of changes in the population's structure and economic participation. The 1981 and 1991 censuses and the Permanent Survey of Households were the sources of data. Immigration to Argentina has declined considerably in recent years, but it is still a factor in the population growth of metropolitan Buenos Aires. Between the 1981 and 1991 censuses, the population aged 15 and over grew by 10.9/1000, or a total of 827,806 people. Migrants from bordering countries increased in number (by 85,109, or 10.3%) and in proportion to the total population (from 3.9% to 4.6%). Migrant women increased at the highest rate (30.1/1000). The greatest growth occurred among men aged 40 and over and among women aged 35 and over. The growth of the economically active population over age 15 for different groups of national origin, sex, and age showed much greater heterogeneity. In 1991, women from bordering countries represented 3.8% of all women in metropolitan Buenos Aires but 5.7% of the total economically active female population and nearly 7% of the economically active female population aged 35 and over. Women from neighboring countries were responsible for 10.3% of the growth in the economically active female population aged 30-34 and 40-44 between 1981 and 1991. The absolute and relative increases in migrants from neighboring countries and their greater economic participation tend to increase the general level of economic activity.^ieng

Synthetic soluble analogs of galactosylceramide (GalCer) bind to the V3 domain of HIV-1 gp120 and inhibit HIV-1-induced fusion and entry.

Galactosylceramide (GalCer) is an alternative receptor allowing human immunodeficiency virus (HIV)-1 entry into CD4-negative cells of neural and colonic origin. Several lines of evidence suggest that this glycosphingolipid recognizes the V3 region of HIV-1 surface envelope glycoprotein gp120. Since the V3 loop plays a key role in the fusion process driven by HIV-1, we decided to synthesize soluble analogs of GalCer with the aim to develop a new class of anti-HIV-1 agents that could neutralize HIV-1 infection through masking of the V3 loop. We describe a short route, in three steps, for the synthesis of soluble analogs of GalCer, using unprotected lactose as the starting sugar. The analogs were prescreened in an assay based on the interaction between a V3 loop-derived synthetic peptide and [3H]suramin, a polysulfonyl compound displaying high affinity for the V3 loop. One of the soluble analogs, i.e. CA52(n15), strongly inhibited the binding of [3H]suramin to the V3 peptide, with an IC50 of 1.2 microM. This molecule was also able to inhibit [3H]suramin binding to recombinant gp120 with similar activity. Using a competition enzyme-linked immunosorbent assay with highly specific anti-gp120 monoclonal antibodies, the region recognized by CA52(n15) could be mapped to amino acids 318-323, which corresponds to the highly conserved consensus motif GPGRAF. Interestingly, the region recognized by suramin, i.e. IQRGP-R-F, was partially overlapping this motif. CA52(n15) was able to inhibit HIV-1-induced cell fusion as well as HIV-1 entry into both CD4(+) and CD4(-)/GalCer+ cells. A structure-activity relationship study showed that: (i) the antiviral activity of soluble analogs of GalCer correlates with V3 loop binding, and (ii) the hydrophobic moiety of the molecule plays an important role in this activity. Taken together, these data show that synthetic analogs of GalCer can inhibit HIV-1 entry into both CD4(-) and CD4(+) cells through masking of the V3 loop.

[Imidazole derivatives, platelet aggregation inhibitors]. / Dérivés imidazoliques inhibiteurs d'agrégation plaquettaire.

Study of the platelet aggregation inhibition has shown the efficiency of compounds with imidazole ring alone or fused. All the compounds resulting of the molecular design starting from these structures has an in vitro activity. We have been able to discuss the correlation existing between activities, toxicities and structures with a particular emphasis to the lipophilicity.

A study on macronuclear chromatin structure in Colpoda inflata (Protozoa, Ciliophora) by means of image analysis.

Resting encystment is a reversible cytodifferentiation phenomenon regularly taking place during the life cycle of Colpodidae. The encystment involves regulation of the macronuclear DNA content, accomplished via chromatin extrusion and DNA synthesis mechanisms. An analysis of macronuclear chromatin texture was carried out in Colpoda inflata logarithmically growing cells, pre-cystic cells, and increasingly aging resting cysts after Feulgen staining. Morphometric and densitometric parameters as well as Markovian chromatin texture variables were utilised for image analysis. Moreover, univariate and multivariate analyses were applied both to macronuclei and to their chromatin extrusion bodies. The results show that structural variations in chromatin appear under macronuclear functional activity conditions, suggesting a dynamic state of chromatin texture throughout a long-term resting encystment.

[Urbanization, urban growth, and migration in Latin America]. / Urbanizacion, crecimiento urbano y migraciones en America Latina.

PIP: The author investigates current patterns of rural-urban and intra-urban population movements in Latin America, and considers their relation to past trends and possible future movements. Sections are included on urbanization levels and trends by country; rural and urban dynamics by country; urban population structure and population dynamics in major cities; and the diversity of migratory movements.^ieng

Microemulsions of perfluorinated and semi-fluorinated compounds.

Perfluorocarbons combine high gas dissolving capacities with extreme chemical and biological inertness: they are good oxygen carriers in artificial blood and in liquid breathing. However fluorocarbons are highly hydrophobic molecules. To solve the problem of their transport, it is necessary to use the perfluorocarbons as an oil-in water emulsion (O/W). To avoid harsh treatment to form such emulsions and in order to have injectable "blood substitutes", microemulsions seem particularly attractive since they are fluid, transparent, thermodynamically stable microheterogeneous systems. Microemulsions, contrarily to classical emulsions, are formed spontaneously by adding suitable surfactants (or a surfactant+a cosurfactant) in appropriate proportions to a non miscible mixture of water and oil. Biocompatible O/W microemulsions are difficult to obtain because of: 1) the existing segregation between perfluorinated and hydrogenated chains, resulting, in some cases in heterogeneities or gelation phases; 2) the toxicity of some components; 3) the possible harmfulness of the dispersed system, etc... We'll discuss all the parameters involved of the microemulsification process, the nature of products, the phase diagrams, and the phase behaviors. This study will outline certain guidelines necessary for the formation of microemulsions of perfluorinated (or almost completely fluorinated) oils with perfluorinated (or partially fluorinated) surfactants.

Analysis of N-acyl aminonaphthalene sulphonic acid derivatives with potential anti-human immunodeficiency virus activity by thin-layer chromatography and flame ionization detection.

A method for checking the purity of N-acyl aminonaphthalene disulphonic acid derivatives was required for a systematic study of the anti-human immunodeficiency virus activity of these agents. We describe the use of thin-layer chromatography and flame ionization detection for the separation of these compounds, which are difficult to analyse by conventional methods. All the samples were prepared in methanol solutions (1 microliter) containing 5 micrograms of aminonaphthalene derivative. These samples were applied to each type SIII Chromarod by a single injection and developed with pure methanol or a methanol-chloroform-ammonium hydroxide (35:55:10, v/v/v) solvent system.

A new surfactant series, the N-alkylamino-1-deoxylactitols: application for extraction of 'op' opiate receptors from frog brain.

A new series of surfactants, the N-alkylamino-1-deoxylactitols, was prepared and employed to extract 'op' opiate receptors from frog brain. These surfactants are both cheap and convenient to prepare. Receptors were reproducibly extracted in a good yield using N-nonylamino-1-deoxylactitol. This derivative, which was not denaturing during the extraction process, could thus be used instead of the more costly digitonin, whose rather variable purity affects yield.