NMR screening of new carbocyanine dyes as ligands for affinity chromatography

Four new carbocyanines containing symmetric and asymmetric heterocyclic moieties and N‐carboxyalkyl groups have been synthesized and characterized. The binding mechanism established between these cyanines and several proteins was evaluated using saturation transfer difference (STD) NMR. The results obtained for the different dyes revealed a specific interaction to the standard proteins lysozyme, α‐chymotrypsin, ribonuclease (RNase), bovine serum albumin (BSA), and gamma globulin. For instance, the two un‐substituted symmetrical dyes (cyanines 1 and 3) interacted preferentially through its benzopyrrole and dibenzopyrrole units with lysozyme, α‐chymotrypsin, and RNase, whereas the symmetric disulfocyanine dye (cyanine 2) bound BSA and gamma globulin through its carboxyalkyl chains. On the other hand, the asymmetric dye (cyanine 4) interacts with lysozyme and α‐chymotrypsin through benzothiazole moiety and with RNase through dibenzopyrrole unit. Thus, STD‐NMR technique was successfully used to screen cyanine–protein interactions and determine potential binding sites of the cyanines for posterior use as ligands in affinity chromatography. Copyright © 2014 John Wiley & Sons, Ltd.     

Molecular cloning and characterization of two novel autophagy-related genes belonging to the ATG8 family from the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)

Rhipicephalus (Boophilus) microplus is an obligate haematophagous arthropod and the major problem for cattle industry due to economic losses it causes. The parasite shows a remarkable adaptability to changing environmental conditions as well as an exceptional ability to survive long-term starvation. This ability has been related to a process of intracellular protein degradation called autophagy. This process in ticks is still poorly understood and only few autophagy-related (ATG) genes have been characterized. The aim of the present study was to examine the ESTs database, BmiGI, of R. microplus searching for ATG homologues. We predicted five putative ATG genes, ATG3, ATG4, ATG6 and two ATG8s. Further characterization led to the identification of RmATG8a and RmATG8b, homologues of GABARAP and MAP1LC3, respectively, and both of them belonging to the ATG8 family. PCR analyses showed that the expression level of RmATG8a and RmATG8b was higher in egg and larval stages when compared to ovary and midgut from adult ticks. This up-regulation coincides with the period in which ticks are in a starvation state, suggesting that autophagy is active in R. microplus.     

Knowledge,Attitudes and Practices Related to Visceral Leishmaniasis in Rural Communities of Amhara State: A Longitudinal Study in Northwest Ethiopia

Background

In the northwest of Ethiopia, at the South Gondar region, there was a visceral leishmaniasis (VL) outbreak in 2005, making the disease a public health concern for the regional health authorities ever since. The knowledge on how the population perceives the disease is essential in order to propose successful control strategies.

Methodology/Principal findings

Two surveys on VL knowledge, attitudes and practices were conducted at the beginning (May 2009) and at the end (February 2011) of a VL longitudinal study carried out in rural communities of Libo Kemkem and Fogera, two districts of the Amhara Regional State. Results showed that VL global knowledge was very low in the area, and that it improved substantially in the period studied. Specifically, from 2009 to 2011, the frequency of proper knowledge regarding VL signs and symptoms increased from 47% to 71% (p<0.0001), knowledge of VL causes increased from 8% to 25% (p<0.0001), and knowledge on VL protection measures from 16% to 55% (p<0.0001). Moreover, the improvement observed in VL knowledge was more marked among the families with no previous history of VL case. Finally, in 2011 more than 90% of the households owned at least an impregnated bed net and had been sprayed, and attitudes towards these and other protective measures were very positive (over 94% acceptance for all of them).

Conclusions/Significance

In 2009 the level of knowledge regarding VL was very low among the rural population of this area, although it improved substantially in the study period, probably due to the contribution of many actors in the area. VL patients and relatives should be appropriately informed and trained as they may act as successful health community agents. VL risk behavioural patterns are subject to change as attitudes towards protective measures were very positive overall.     

In vitro formation of mineralized cartilagenous tissue by articular chondrocytes

Summary Study of the deep articular cartilage and adjacent calcified cartilage has been limited by the lack of an in vitro culture system which mimics this region of the cartilage. In this paper we describe a method to generate mineralized cartilagenous tissue in culture using chondrocytes obtained from the deep zone of bovine articular cartilage. The cells were plated on Millipore CM^R filters. The chondrocytes in culture accumulated extracellular matrix and formed cartilagenous tissue which calcified when β-glycerophosphate was added to the culture medium. The cartilagenous tissue generated in vitro contains both type II and type X collagens, large sulfated proteoglycans, and alkaline phosphatase activity. Ultrastructurally, matrix vesicles were seen in the extracellular matrix. Selected area electron diffraction confirmed that the calcification was composed of hydroxyapatite crystals. The chondrocytes, as characterized thus far, appear to maintain their phenotype under these culture conditions which suggests that these cultures could be used as a model to examine the metabolism of cells from the deep zone of cartilage and mineralization of cartilagenous tissue in culture.     

NUCEL (Cell and Molecular Therapy Center): A Multidisciplinary Center for Translational Research in Brazil

Social and economical development is closely associated with technological innovation and a well-developed biotechnological industry. In the last few years, Brazil’s scientific production has been steadily increasing; however, the number of patents is lagging behind, with technological and translational research requiring governmental incentive and reinforcement. The Cell and Molecular Therapy Center (NUCEL) was created to develop activities in the translational research field, addressing concrete problems found in biomedical and veterinary areas and actively searching for solutions by employing a genetic engineering approach to generate cell lines over-expressing recombinant proteins to be transferred to local biotech companies, aiming at furthering the development of a national competence for local production of biopharmaceuticals of widespread use and of life-saving importance. To this end, mammalian cell engineering technologies were used to generate cell lines over-expressing several different recombinant proteins of biomedical and biotechnological interest, namely, recombinant human Amylin/IAPP for diabetes treatment, human FVIII and FIX clotting factors for hemophilia, human and bovine FSH for fertility and reproduction, and human bone repair proteins (BMPs). Expression of some of these proteins is also being sought with the baculovirus/insect cell system (BEVS) which, in many cases, is able to deliver high-yield production of recombinant proteins with biological activity comparable to that of mammalian systems, but in a much more cost-effective manner. Transfer of some of these recombinant products to local Biotech companies has been pursued by taking advantage of the São Paulo State Foundation (FAPESP) and Federal Government (FINEP, CNPq) incentives for joint Research Development and Innovation partnership projects.     

Weight–length relationships of six batoids in the Ecuadorian Pacific

Weight–length relationships (WLR) were estimated for six batoids, namely: Urotrygon chilensis, Narcine entemedor, Rhinobatos leucorhynchus, Rhinobatos planiceps, Rhinobatos prahli and Urobatis tumbesensis captured in the Ecuadorian Pacific. Data were collected between October 2013 and August 2014 in two artisanal fishing ports. In addition, this represents the first WLR estimations for five of the species.     

Electrophysiological characterization of Tityus obscurus β toxin 1 (To1) on Na+-channel isoforms

To1, previously named Tc49b, is a peptide neurotoxin isolated from venom of the scorpion Tityus obscurus that is responsible for lethal human poisoning cases in the Brazilian Amazonian region. Previously, To1 was shown to be lethal to mice and to change Na⁺ permeation in cerebellum granular neurons from rat brain. In addition, To1 did not affect Shaker B K⁺ channels. Based on sequence similarities, To1 was described as a β-toxin. In the present work, To1 was purified from T. obscurus venom and submitted to an electrophysiological characterization in human and invertebrate Na_V channels. The analysis of the electrophysiological experiments reveal that To1 enhances the open probability at more negative potentials of human Na_V 1.3 and 1.6, of the insect channel BgNa_V1 and of arachnid VdNa_V1 channel. In addition, To1 reduces the peak of Na⁺ currents in some of the Na_Vs tested. These results support the classification of the To1 as a β-toxin. A structure and functional comparison to other β-toxins that share sequence similarity to To1 is also presented.     

Inbreeding alters a plant-predispersal seed predator interaction

The effect of inbreeding on genetic diversity is expected to decrease plant defences or vigour-related traits that, in turn, can modify the pattern of attack by herbivores. The selective damage caused by herbivores can produce variable fitness costs between inbred and outcrossed progenies influencing the evolution of a species’ plant mating system. By exposing inbred and outcrossed plants to natural conditions of seed predation, we assessed whether inbreeding increases weevil incidence and infestation, and how weevil seed predation affects the fitness of inbred and outcrossed progeny. To test if inbreeding affected the host’s plant quality, we weighed the biomass of weevils developed in inbred and outcrossed progenies. An additional experiment was carried out to examine whether weevils preferentially attack vigorous plants regardless from the level of inbreeding. The average value of leaf size was 21% larger in outcrossed plants than in inbred plants. Likewise, weevil incidence and infestation were 13 and 40%, respectively, higher on outcrossed plants relative to their inbred counterparts. However, the relative impact of seed predation was significantly lower in outcrossed progeny than in inbred progeny. In contrast, inbreeding did not alter host plant quality and weevils developed in inbred and outcrossed plants had a similar biomass. Variations in fruit number were consistently associated with the infestation level in both experiments, whereas leaf size only predicted the number of weevils in one experiment, suggesting that fruit number is the most influential vigour-related characteristic of a weevil attack. These findings indicate that the costs of inbreeding of the interaction D. stramonium-T. soror were higher for inbred plants than for outcrossed plants. The interaction between seed predation and inbreeding depression could prevent the fixation of selfing as a unique reproductive strategy in D. stramonium.