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Jessica Perez, Javier Cifuentes, Monica Cuellar, Alejandra Suarez-Arnedo, Juan C Cruz, Carolina Muñoz-Camargo GINIB Research Group, Department of Biomedical Engineering, Universidad de los Andes, Bogotá, ColombiaCorrespondence: Carolina Muñoz-Camargo; Juan C Cruz Tel +57-1 3394949 Ext. 1789, 1853Email c.munoz2016@uniandes.edu.co; jc.cruz@uniandes.edu.coIntroduction: Controlled delivery of therapeutic molecules in a localized manner has become an area of interest due to its potential to reduce drug exposure to healthy tissues and consequently to minimize undesirable side effects. We have recently introduced novel cell-penetrating vehicles by immobilizing the antimicrobial peptide Buforin II (BUF-II) on magnetite nanoparticles (MPNPs). Despite the potent translocating abilities of such nanobioconjugates, they failed to preserve the antimicrobial activity of native BUF-II. In this work, we explored immobilization on MNPs with the aid of polymer surface spacers, which has been considered as an attractive alternative for the highly efficient conjugation of various biomolecules.Methods: Here, we immobilized BUF-II on polyetheramine-modified magnetite nanoparticles to preserve its structural integrity. As a result, for the obtained nanobioconjugates the lost antimicrobial activity against gram-positive and gram-negative bacteria was only 50% with respect to the native BUF-II. The nanobioconjugates were also characterized via FTIR, DLS, TEM, and TGA. Delivery on THP-1, HaCaT, HFF, and Escherichia coli cells was conducted to confirm capability for cell membrane translocation.Results: Colocalization with Lysotracker showed an endosomal escape efficiency of about 73∓12% in THP-1 cells. Avoidance of endocytic pathways of internalization was qualitatively confirmed by a delivery assay at low temperature. Nuclear penetration of the nanobioconjugates was corroborated via confocal microscopy and showed high biocompatibility as demonstrated by hemolysis levels below 5% and acute cytotoxicity of around 15%.Conclusion: The obtained nanobioconjugates were capable of translocating the cell membrane and nuclei of different normal and cancerous cell lines without significantly decreasing viability. This makes the vehicle addressable for a number of applications ranging from antimicrobial topical treatments to the delivery of nucleotides and therapeutic molecules with difficulties to bypass cell membranes.Keywords: Buforin-II conjugates, drug delivery, translocation, cell-penetrating peptides, nanomaterials

Monica Cuellar,1 Javier Cifuentes,1 Jessica Perez,1 Alejandra Suarez-Arnedo,1 Julian A Serna,1 Helena Groot,2 Carolina Muñoz-Camargo,1 Juan C Cruz1 1Department of Biomedical Engineering, Universidad de los Andes, Bogotá, Colombia; 2Human Genetics Laboratory, Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia Introduction: One of the major challenges of modern pharmacology is the development of systems for the delivery of therapeutic molecules in a controlled and localized manner. One strategy is to use nanostructured supports, which are well suited to carry a large number of molecules on a per mass basis. A major challenge for these supports is, however, their limited ability to bypass the cell membrane. Recent studies propose that to overcome this issue, potent translocating cell-penetrating peptides (CPPs) can be conjugated to their surfaces. Methods: Here, we conjugated the antimicrobial CPP buforin II (BUF2) to the surface of magnetite nanoparticles to enhance their cell penetration. Conjugates were characterized via Fourier transform infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis, and their biocompatibility was corroborated. The conjugates were delivered in both bacterial and mammalian cells demonstrating the intracellular inclusion in THP-1 cells for the first time. Results: Despite the promising outcome, our studies showed that the obtained conjugates failed to maintain the native antimicrobial activity of BUF2. We hypothesize that to overcome this issue, a flexible linker can be inserted prior to conjugation. Conclusion: Our study highlights the potential of BUF2-magnetite conjugates as cell-penetrating vehicles for the targeted delivery of pharmacological agents. This provides support for the idea of a promising combined drug delivery and antimicrobial peptide therapy. Keywords: BUF2-magnetite, antimicrobial activity, cell-penetrating peptides, nanomaterials, drug delivery

Des recherches ont été effectuées concernant la zooépibiose de l’écrevisse signal (Pacifastacus leniusculus, D.), provenant d’un centre d’astaciculture espagnol, au cours de la période 1997-1998. Les organismes épibiotiques dominants trouvés sur l’exosquelette appartiennent aux groupes zoologiques d’Invertébrés suivants : Mastigophora (Bodo), Cilliophora (Stentor, Epistylis, Zoothamnium, Acineta), Turbelaria (Temnocephala), Rotifera (Brachionus), Annelida (Branchiobdella), Acarina (Hygrobates) et Ostracode (Eucypris ou Enthocytera), on souligne le nombre élevé de Branchiobdellides de l’espèce Branchiobdella instabilia M., dont les quantités minimum et maximum, en mâles et femelles, oscillent de 12 à 139 et de 7 à 130, respectivement. Les hyperbranchiobdelloses provoquent des automutilations, des décollements des pinces et autres appendices, des mues anormales, des lésions cuticulaires, de l’hémocytopénie et des changements éthologiques. Les colonisations maximales d’Ostracodes de l’espèce Eucypris virens, J.O., Enthocytera heterodonta, R., dans les poches d’incubation des femelles donnent lieu à une coloration rougeâtre des oeufs et à leur perte postérieure. Compte tenu de leur nombre limité et de la période d’épibiose, les genres des sous-types Mastigophora, Ciliophora, Turbelaria, Rotifera et Arachnida ne représentent aucun danger pour les écrevisses. En ce qui concerne la zooépibiose associée aux appendices et aux régions du corps des écrevisses du Pacifique, les chélipèdes ou pinces constituent le substrat où se place de préférence le genre Branchiobdella ; le céphalothorax sert de support à tous les groupes taxonomiques d’épibiontes identifiés.

Land supplies multiple goods and services vital to humans and the environment. In the last decades, increasing evidence of growing land degradation are made apparent. A limited and depleting resource base, the reliance on climate-sensitive sectors and its large population, make South Asia highly vulnerable to climate change. Observed changes in climate include increases in temperature and increased monsoon variability and rainfall pattern leading to drought and flooding. Projected changes include increasing temperatures, rising sea levels, increasing cyclonic activity and higher variability of rainfall, all having enormous impacts on farming communities. At the same time, the region is rich in traditional agricultural knowledge (TAK), specialized in managing local agroecosystems to ensure food availability, tackling climatic risks and other ecological uncertainties. Particularly relevant is TAK related to land management to preserve soil fertility and avoid soil erosion. Ethnographic research is a valuable source of TAK, although this is rarely analysed with a climate change perspective. Based on a qualitative systematic review, and an expert's on-line survey, in this paper we review land management TAK and assess its potential for climate change adaptation. The review shows there is a vast amount of untapped TAK ethnographic research with potential for climate change adaptation. [ABSTRACT FROM AUTHOR]

Background: The Rio Grande Valley (RGV) and Laredo regions located along the Texas-Mexico border consist of seven counties with a population of approximately 1.5 million people and a high uninsured rate (33.5%). Cervical cancer mortality in these border counties is approximately 30% higher than the rest of Texas. The RGV and Laredo areas were studied to better understand the state of access to cervical cancer prevention services along the Texas-Mexico border.Methods: Data on the population served and the services provided were analyzed to determine the gap between cervical cancer screenings recommended versus those received. Through interviews, we gathered the perspectives of 16 local stakeholders regarding cervical cancer screening for underserved individuals in the region.Findings: It is estimated that 69,139 uninsured women aged 21-64 years in the RGV/Laredo per year are recommended to undergo cervical cancer screening with Papanicolaou (Pap) and/or human papillomavirus (HPV) testing, but only 8941 (12.9%) Pap tests are being performed by the Federally Qualified Health Center (FQHC) serving uninsured women in these regions. Systemic barriers identified include insufficient provider clinical capacity, the high cost of healthcare, and uncertainty about government funding sources. Patient barriers identified include inadequate knowledge on navigating the local healthcare system, low health literacy, lack of money and childcare, an inability to miss work, limited transportation, and fear of deportation.Conclusion: Decreasing the disparity between cervical cancer screening services provided and those recommended requires addressing the barriers, identified by local experts, which prevent uninsured women from accessing care. These challenges are being addressed through ongoing programs and collaborations. [ABSTRACT FROM AUTHOR]

Climate variations are considered one of several interacting factors affecting food security. Specifically, in the Indo-Gangetic Plains, increased exposure to droughts and floods are expected. Local traditional knowledge in agriculture (LTKA) is proposed in this article as valid knowledge to ensure food availability under climate change, given its long experience in dealing with climate variability. Focused on water strategies, we have conducted a literature review on LTKA practices in the Indo-Gangetic Plains complemented with a questionnaire of experts to identify LTKA-based practices that might be useful in climate-change driven water scenarios. The practices identified are categorized as a) water harvesting and recycling; b) local irrigation systems; and c) and maintenance, conservation, and water allocation. We found that a) despite acknowledging the potential of LTKA to face floods and droughts, very few studies explicitly make the link between LTKA and climate change; and b) LTKA in water management heavily relays on social norms and local institutions and, thus, any attempts to replicate it need to consider this. We conclude that agroecology can help to promote these practices since it emphasizes the collective management from below as the main approach for the design of sustainable agroecosystems and, thus, include local institutions as an essential strategy for adaptation. [ABSTRACT FROM AUTHOR]

Biosurfactants are produced by hydrocarbon-degrading marine bacteria in response to the presence of water-insoluble hydrocarbons. This is believed to facilitate the uptake of hydrocarbons by bacteria. However, these diffusible amphiphilic surface-active molecules are involved in several other biological functions such as microbial competition and intra- or inter-species communication. We report the isolation and characterization of a marine bacterial strain identified as Cobetia sp. MM1IDA2H-1, which can grow using the sulfur-containing heterocyclic aromatic hydrocarbon dibenzothiophene ( DBT). As with DBT, when the isolated strain is grown in the presence of a microbial competitor, it produces a biosurfactant. Because the obtained biosurfactant was formed by hydroxy fatty acids and extracellular lipidic structures were observed during bacterial growth, we investigated whether the biosurfactant at its critical micelle concentration can interfere with bacterial communication systems such as quorum sensing. We focused on Aeromonas salmonicida subsp. salmonicida, a fish pathogen whose virulence relies on quorum sensing signals. Using biosensors for quorum sensing based on Chromobacterium violaceum and Vibrio anguillarum, we showed that when the purified biosurfactant was mixed with N-acyl homoserine lactones produced by A. salmonicida, quorum sensing was inhibited, although bacterial growth was not affected. In addition, the transcriptional activities of A. salmonicida virulence genes that are controlled by quorum sensing were repressed by both the purified biosurfactant and the growth in the presence of Cobetia sp. MM1IDA2H-1. We propose that the biosurfactant, or the lipid structures interact with the N-acyl homoserine lactones, inhibiting their function. This could be used as a strategy to interfere with the quorum sensing systems of bacterial fish pathogens, which represents an attractive alternative to classical antimicrobial therapies in fish aquaculture. [ABSTRACT FROM AUTHOR]

The design of optical sensor arrays encompasses tasks such as the acquisition of sensor optical parameters, as for example color features, and the calibration of a multivariate method to model the array global behavior. Different techniques have been used to model the sensor array responses, such as multivariate regression or neural networks, although they show certain limitations. The former methods require either high amount of computer memory or speed so therefore they are not suitable for implementation in portable electronic devices with low resources, while the later is a black box whose operation cannot be easily modeled and explained for industrial development validation. This work addresses these problems and proposes an expert system to overcome the previous drawbacks. The approach makes an accurate pH prediction, and it comprises a balance between memory and microprocessor speed for its integration within embedded systems with low memory and chip resources. In addition, it is also able to provide a high expressive explanation of why such prediction was made, so that the industrial validation is easier than using other proposals such as neural networks. [ABSTRACT FROM PUBLISHER]

Mixed-lineage leukemia (MLL) fusion proteins are associated with a unique class of leukemia that is characterized by the simultaneous expression of lymphoid-specific as well as myeloid-specific genes. Here we report the first experimental model of MLL. Murine bone marrow cells were retrovirally transduced to express the MLL-eleven nineteen leukemia (MLL-ENL) fusion protein. When cultivated in flt-3 ligand, stem cell factor and interleukin-7 (IL-7) in a stroma-free culture system MLL-ENL-transduced as well as control cells showed a wave of B-lymphopoiesis. Whereas the controls exhausted their proliferative capacity in a CD19+/B220+ state, a continuously proliferating CD19-/B220+ cell population emerged in the MLL-ENL-transduced cultures. Despite the lymphoid surface marker, these cells were of monocytoid morphology. The immortalized cells contained unrearranged retrovirus, expressed MLL-ENL mRNA and were able to grow in syngenic recipients. From the diseased animals an MLL-ENL positive, B220+/CD19- cell type could be reisolated and cultivated in vitro. In analogy to human MLL, MLL-ENL-transformed cells not only coexpressed lymphocyte-specific (rag1, rag2, pax5, Tdt) and monocyte-specific genes (lysozyme, c-fms), but also showed rearrangements of the genomic immunoglobulin locus. This model shows that MLL-ENL influences events of early lineage determination and it will enable the investigation of the underlying molecular processes.Oncogene (2003) 22, 1629-1637. doi:10.1038/sj.onc.1206104 [ABSTRACT FROM AUTHOR]

Antiphospholipid antibodies (aPL) are associated with thrombosis, thrombocytopenia and recurrent fetal loss in humans and in some animal models. Immunization with β2 glycoprotein I (β2GPI) induced aPL production in normal rabbits and mice. However, the association of these antibodies with disease manifestations remains controversial. To determine whether induction of aPL by β2GPI immunization in an autoimmune strain of mice (MRL/++) would result in acceleration of clinical and serological autoimmune disease manifestations, three groups of 8-week- old female mice were studied. One group was immunized with β2GPI, and one with ovalbumin (OVA); the third was not immunized. After two booster injections, sera were analysed for the presence of anticardiolipin (aCL) and anti-DNA by ELISA and anti-nuclear antibody (ANA) by immunofluorescence. Mice were studied for thrombocytopenia, proteinuria, fecundity rates, litter sizes and the development of central nervous system dysfunction. Elevated levels of aCL, anti-DNA and ANA were detected in all β2GPI-immunized, in three OVA-immunized, and in none of the unimmunized mice. The anti-DNA antibodies were inhibited by CL micelles, suggesting cross- reactivity between aCL and anti-DNA. Platelet counts, fecundity rates and litter size were reduced in β2GPI-immunized but not in OVA-immunized or unimmunized mice. None of the mice developed neurological dysfunction or significant proteinuria over a 10-week period post-immunization. These findings suggest that β2GPI immunization induces aPL in MRL/++ mice associated with accelerated autoimmune manifestations resembling the antiphospholipid syndrome. [ABSTRACT FROM AUTHOR]