Adsorptive features of acid-treated olive stones for drin pesticides: Equilibrium,kinetic and thermodynamic modeling studies

The adsorption behavior of drin pesticides from aqueous solution onto acid treated olive stones (ATOS) was investigated using stir bar sorptive extraction and gas chromatography coupled with mass spectroscopy. The effects of sorbent particle size, adsorbent dose, contact time, concentration of pesticide solution and temperature on the adsorption processes were systematically studied in batch shaking sorption experiments. Maximum removal efficiency (94.8%) was reached for aldrin (0.5 mg L⁻¹) using the fraction 63–100 μm of ATOS (solid/liquid ratio: 1 g L⁻¹). Experimental data were modeled by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. The Freundlich isotherm model (R² = 0.98–0.99) fitted the equilibrium data better than the Langmuir and D–R isotherm models, with low sum of error values (SE = 1.4–9.2%). The mean adsorption free energy derived from the D–R isotherm model (R² = 0.95–0.99) showed that the adsorption of drin pesticides was taken place by weak physical forces, such as van der Waals forces and hydrogen bonding. The calculated thermodynamic parameters, ΔH, ΔS and ΔG prove that drin pesticides adsorption on ATOS was feasible, spontaneous and exothermic under examined conditions. The pseudo first order, pseudo second order kinetic and the intra-particle diffusion models were used to describe the kinetic data and rate constants were evaluated.     

Etude entomologique de cinq foyers de leishmaniose cutanée dans la province de Sidi Kacem au nord du Maroc

Résumé. La leishmaniose cutanée est un important problème de santé publique dans la province de Sidi Kacem au nord-ouest du Maroc. L'incidence de cette affetion, due aussi bien à Leishmania tropica qu'à L. infantum est en augmentation progressive depuis 1997. La présente étude a été menée dans le but d'étudier l'écologie et la dynamique des populations des vecteurs de cette maladie dans les principaux foyers de cette province. Un total de 4504 spécimens appartenant à deux genres et six espèces a été capturé à l'aide de pièges adhésifs et lumineux, dans cinq foyers. Les espèces dominantes sont Phlebotomus sergenti représentant 42,6% du total des phlébotomes capturés et P. longicuspis avec 27,2% des captures. Ces deux espèces sont présentes de mai à novembre et évoluent en deux générations avec deux pics de densité, le premier en juin et le second en septembre. En considérant la grande spécificité vecteur-parasite connue en épidémiologie des leishmanioses ainsi que l'abondance des espèces capturées pendant la saison favorable à la transmission, P. sergenti et P. longicuspis seraient respectivement les vecteurs les plus probables des leishmanioses à L. tropica et à L. infantum dans la région étudiée. Le risque de transmission de la maladie serait plus grand durant le deuxième pic de densité en fin été- début automne.     

Smartphone and a freely available application as a new tool to record locomotor activity rhythm in large mammals and humans

ABSTRACT

Daily pattern of locomotor activity (LA), one of the most studied rhythms in humans and rodents, has not been widely investigated in large mammals. This is partly due to the high cost and breakability of used automatic devices. Since last decade, smartphones are becoming ubiquitous. Meanwhile, several applications detecting activity by using internal sensors were made available. In this study, we assumed that this device could be a cheaper and easier way to measure the LA rhythm in humans and large mammals, like camel and goat. A smartphone application (Nokia Mate Health), normally used to quantify physical activities in humans, was chosen for the study. To validate the rhythm data obtained from the smartphone, LA rhythm was simultaneously recorded using an automatic device, the Actiwatch-Mini®. Results showed that the smartphone provided a clear and significant daily rhythm of LA. The visual assessment of the superimposed LA rhythm’s curves in all three species showed that the smartphone application displayed similar rhythms as those recorded by the Actiwatch-Mini. Highly significant positive correlation (p≤ 0.0001) exists between the two recording rhythms. The daily periods were both the same at 24.0 h. Acrophases were also significantly similar and occurring around mid-day: 11:40 ± 0.35 h vs 11:41 ± 0.35 h for the camel, 11:25 ± 0.19 h vs 11:37 ± 0.25 h for the goat and 13:04 ± 0.11 h vs 13:51 ± 0.28 h for humans using smartphone and Actiwatch, respectively. The related mesor and amplitude were also close between the two recording devices. Results indicate clearly that using smartphones constitutes a reliable cheap tool to study LA rhythm for chronobiology studies, especially in laboratories facing lack of funding.     

Genetic structure and core collection of the World Olive Germplasm Bank of Marrakech: towards the optimised management and use of Mediterranean olive genetic resources

The conservation of cultivated plants in ex-situ collections is essential for the optimal management and use of their genetic resources. For the olive tree, two world germplasm banks (OWGB) are presently established, in Córdoba (Spain) and Marrakech (Morocco). This latter was recently founded and includes 561 accessions from 14 Mediterranean countries. Using 12 nuclear microsatellites (SSRs) and three chloroplast DNA markers, this collection was characterised to examine the structure of the genetic diversity and propose a set of olive accessions encompassing the whole Mediterranean allelic diversity range. We identified 505 SSR profiles based on a total of 210 alleles. Based on these markers, the genetic diversity was similar to that of cultivars and wild olives which were previously characterised in another study indicating that OWGB Marrakech is representative of Mediterranean olive germplasm. Using a model-based Bayesian clustering method and principal components analysis, this OWGB was structured into three main gene pools corresponding to eastern, central and western parts of the Mediterranean Basin. We proposed 10 cores of 67 accessions capturing all detected alleles and 10 cores of 58 accessions capturing the 186 alleles observed more than once. In each of the 10 cores, a set of 40 accessions was identical, whereas the remaining accessions were different, indicating the need to include complementary criteria such as phenotypic adaptive and agronomic traits. Our study generated a molecular database for the entire OWGB Marrakech that may be used to optimise a strategy for the management of olive genetic resources and their use for subsequent genetic and genomic olive breeding.     

Opsonization of HIV with complement enhances infection of dendritic cells and viral transfer to CD4 T cells in a CR3 and DC-SIGN-dependent manner

In the present study, we demonstrated that opsonization of primary HIV-1 with human complement enhances infection of immature monocyte-derived dendritic cells (iDC) and transmission in trans of HIV to autologous CD4(+) T lymphocytes. Infection of iDC by opsonized primary R5- and X4-tropic HIV was increased 3- to 5-fold as compared with infection by the corresponding unopsonized HIV. Enhancement of infection was dependent on CR3 as demonstrated by inhibition induced by blocking Abs. The interaction of HIV with CCR5 and CXCR4 on iDC was affected by opsonization. Indeed, stromal-derived factor-1 was more efficient in inhibiting infection of iDC with opsonized R5-tropic HIV-1(BaL) (45%) than with heat-inactivated complement opsonized virus and similarly RANTES inhibited more efficiently infection of iDC with opsonized X4-tropic HIV-1(NDK) (42%) than with heat-inactivated complement opsonized virus. We also showed that attachment of complement-opsonized virus to DC-specific ICAM-grabbing nonintegrin (DC-SIGN) molecule on iDC and HeLa DC-SIGN(+) CR3(-) cells was 46% and 50% higher compared with heat-inactivated complement opsonized virus, respectively. Hence, Abs to DC-SIGN suppressed up to 80% and 60% the binding of opsonized virus to HeLa cells and iDC, respectively. Furthermore, Abs to DC-SIGN inhibited up to 70% of the infection of iDC and up to 65% of infection in trans of autologous lymphocytes with opsonized virus. These results further demonstrated the role of DC-SIGN in complement opsonized virus uptake and infection. Thus, the virus uses complement to its advantage to facilitate early steps leading to infection following mucosal transmission of HIV.     

Increased radiation-induced apoptosis of Saos2 cells via inhibition of NFkappaB: a role for c-Jun N-terminal kinase

To elucidate the possible effect of NFkappaB on radioresistance, we used the osteosarcoma cell line Saos2, stably expressing the NFkappaB constitutive inhibitor, mIkappaB (Saos2-mIkappaB) or stably transfected with the empty vector (Saos2-EV). Ionizing radiation induced "intrinsic" apoptosis in Saos2-mIkappaB cells but not in Saos2-EV control cells, with intact NFkappaB activity. We find as expected, that this NFkappaB activity was enhanced following irradiation in the Saos2-EV control cells. On the other hand, inhibition of NFkappaB signaling in Saos2-mIkappaB cells led to the upregulation of the pro-apoptotic systems, such as Bax protein and c-Jun N-terminal Kinase (JNK)/c-Jun/AP1 signaling. Inhibition of NFkappaB resulted in decreased expression of the DNA damage protein GADD45beta, a known inhibitor of JNK. Subsequently, JNK activation of c-Jun/AP-1 proteins increased radiation-induced apoptosis in these mutants. Radiation-induced apoptosis in Saos2-mIkappaB cells was inhibited by the JNK specific inhibitor SP600125 as well as by Bcl-2 over-expression. Furthermore, release of cytochrome-c from mitochondria was increased and caspase-9 and -3 were activated following irradiation in Saos2-mIkappaB cells. Antisense inhibition of GADD45beta in Saos2-EV cells significantly enhanced apoptosis following irradiation. Our results demonstrate that radioresistance of Saos2 osteosarcoma cells is due to NFkappaB-mediated inhibition of JNK. Our study brings new insight into the mechanisms underlying radiation-induced apoptosis of osteosarcoma, and may lead to development of new therapeutic strategies against osteosarcoma.     

Validation of microsatellite multiplexes for parentage analysis and species discrimination in two hybridizing species of coral reef fish (Plectropomus spp., Serranidae)

Microsatellites are often considered ideal markers to investigate ecological processes in animal populations. They are regularly used as genetic barcodes to identify species, individuals, and infer familial relationships. However, such applications are highly sensitive the number and diversity of microsatellite markers, which are also prone to error. Here, we propose a novel framework to assess the suitability of microsatellite datasets for parentage analysis and species discrimination in two closely related species of coral reef fish, Plectropomus leopardus and P. maculatus (Serranidae). Coral trout are important fisheries species throughout the Indo‐Pacific region and have been shown to hybridize in parts of the Great Barrier Reef, Australia. We first describe the development of 25 microsatellite loci and their integration to three multiplex PCRs that co‐amplify in both species. Using simulations, we demonstrate that the complete suite of markers provides appropriate power to discriminate between species, detect hybrid individuals, and resolve parent–offspring relationships in natural populations, with over 99.6% accuracy in parent–offspring assignments. The markers were also tested on seven additional species within the Plectropomus genus with polymorphism in 28–96% of loci. The multiplex PCRs developed here provide a reliable and cost‐effective strategy to investigate evolutionary and ecological dynamics and will be broadly applicable in studies of wild populations and aquaculture brood stocks for these closely related fish species.     

Ultrasmall gold-doxorubicin conjugates rapidly kill apoptosis-resistant cancer cells

Ultrasmall (mean diameter, 2.7 nm) gold nanoparticles conjugated to doxorubicin (Au-Dox) are up to 20-fold more cytotoxic to B16 melanoma cells than the equivalent concentration of doxorubicin alone, and act up to six times more quickly. Ultrasmall Au-Dox enters the cell endocytic vesicles and is also seen free in the cytoplasm and nuclei. This is in distinct contrast to larger particles reported in previous studies, which are excluded from the nucleus and which show no increased toxicity over Dox alone. Cell death with Au-Dox is confirmed to be apoptotic by TUNEL staining and ultrastructural examination using transmission electron microscopy. To further explore the mechanism of action, two other cell lines were examined: HeLa cells which are highly sensitive to Dox, and HeLa cells overexpressing Bcl-2 which show impaired apoptosis and Dox resistance. Interestingly, the Dox-sensitive cells show a slightly decreased sensitivity to Au-Dox relative to Dox alone, whereas the Dox-resistant cells are not resistant to Au-Dox. These results have implications for the design of chemotherapeutic nanoparticles, suggesting that it is possible to selectively target apoptosis-resistant cancer cells while at the same time reducing cytotoxicity to normal cells.