Urban parasitology: visceral leishmaniasis in Brazil

Since the early 1980s, visceral leishmaniasis (VL) which is, in general, a rural zoonotic disease, has spread to the urban centers of the north, and now the south and west of Brazil. The principal drivers differ between cities, though human migration, large urban canid populations (animal reservoir), and a decidedly peripatetic and adaptable sand fly vector are the primary forces. The exact number of urban cases remains unclear as a result of challenges with surveillance. However, the number of urban cases registered continues to increase annually. Most control initiatives (e.g. culling infected dogs and household spraying to kill the sand fly) could be effective, but have proven hard to maintain at large scales due to logistical, financial and other reasons. In this article, the urbanization of VL in Brazil is reviewed, touching on these and other topics related to controlling VL within and outside Brazil.     

Insight into the salivary transcriptome and proteome of Dipetalogaster maxima

Dipetalogaster maxima is a blood-sucking Hemiptera that inhabits sylvatic areas in Mexico. It usually takes its blood meal from lizards, but following human population growth, it invaded suburban areas, feeding also on humans and domestic animals. Hematophagous insect salivary glands produce potent pharmacologic compounds that counteract host hemostasis, including anticlotting, antiplatelet, and vasodilatory molecules. To obtain further insight into the salivary biochemical and pharmacologic complexity of this insect, a cDNA library from its salivary glands was randomly sequenced. Salivary proteins were also submitted to one- and two-dimensional gel electrophoresis (1DE and 2DE) followed by mass spectrometry analysis. We present the analysis of a set of 2728 cDNA sequences, 1375 of which coded for proteins of a putative secretory nature. The saliva 2DE proteome displayed approximately 150 spots. The mass spectrometry analysis revealed mainly lipocalins, pallidipins, antigen 5-like proteins, and apyrases. The redundancy of sequence identification of saliva-secreted proteins suggests that proteins are present in multiple isoforms or derive from gene duplications.     

How to Make a Dolphin: Molecular Signature of Positive Selection in Cetacean Genome

Cetaceans are unique in being the only mammals completely adapted to an aquatic environment. This adaptation has required complex changes and sometimes a complete restructuring of physiology, behavior and morphology. Identifying genes that have been subjected to selection pressure during cetacean evolution would greatly enhance our knowledge of the ways in which genetic variation in this mammalian order has been shaped by natural selection. Here, we performed a genome-wide scan for positive selection in the dolphin lineage. We employed models of codon substitution that account for variation of selective pressure over branches on the tree and across sites in a sequence. We analyzed 7,859 nuclear-coding ortholog genes and using a series of likelihood ratio tests (LRTs), we identified 376 genes (4.8%) with molecular signatures of positive selection in the dolphin lineage. We used the cow as the sister group and compared estimates of selection in the cetacean genome to this using the same methods. This allowed us to define which genes have been exclusively under positive selection in the dolphin lineage. The enrichment analysis found that the identified positively selected genes are significantly over-represented for three exclusive functional categories only in the dolphin lineage: segment specification, mesoderm development and system development. Of particular interest for cetacean adaptation to an aquatic life are the following GeneOntology targets under positive selection: genes related to kidney, heart, lung, eye, ear and nervous system development.     

Natriuretic peptide system: a link between fat mass and cardiac hypertrophy and hypertension in fat-fed female rats

The present study was designed to develop an animal model of hypertension and cardiac hypertrophy associated with obesity in female rats. Furthermore, we studied the involvement of the natriuretic peptide system in the mechanisms of these conditions. Obesity was induced in Wistar rats by a high fat diet and ovariectomy. The rats were divided into four groups: ovariectomized or sham-operated with high-fat diet and ovariectomized or sham-operated with control diet. After 24 weeks of diet, rats were killed, and their tissues were removed. Cardiac atrial natriuretic peptide (ANP), clearance receptor (NPr-C) gene expression was determined by PCR. ANP concentrations were measured in plasma. Ovariectomized fat-fed rats (OF) showed increased body weight, visceral fat depot and blood pressure and decreased sodium excretion compared to other groups. Also, these rats showed higher heart-to-body weight and cell diameters of ventricular cardiomyocytes and lower cardiac ANP mRNA and plasma ANP than the control group. The adipocyte and renal NPr-C mRNA of OF rats were higher than the control group. These data showed that combined ovariectomy and high fat diet elicited obesity, hypertension and cardiac hypertrophy. These results suggest that the impairment of the natriuretic peptide system may be one of the mechanisms involved not only in development of hypertension but also in cardiac hypertrophy associated with obesity in ovariectomized rats.     

A discontinuous DNA glycosylase domain in a family of enzymes that excise 5-methylcytosine

DNA cytosine methylation (5-meC) is a widespread epigenetic mark associated to gene silencing. In plants, DEMETER-LIKE (DML) proteins typified by Arabidopsis REPRESSOR OF SILENCING 1 (ROS1) initiate active DNA demethylation by catalyzing 5-meC excision. DML proteins belong to the HhH-GPD superfamily, the largest and most functionally diverse group of DNA glycosylases, but the molecular properties that underlie their capacity to specifically recognize and excise 5-meC are largely unknown. We have found that sequence similarity to HhH-GPD enzymes in DML proteins is actually distributed over two non-contiguous segments connected by a predicted disordered region. We used homology-based modeling to locate candidate residues important for ROS1 function in both segments, and tested our predictions by site-specific mutagenesis. We found that amino acids T606 and D611 are essential for ROS1 DNA glycosylase activity, whereas mutations in either of two aromatic residues (F589 and Y1028) reverse the characteristic ROS1 preference for 5-meC over T. We also found evidence suggesting that ROS1 uses Q607 to flip out 5-meC, while the contiguous N608 residue contributes to sequence-context specificity. In addition to providing novel insights into the molecular basis of 5-meC excision, our results reveal that ROS1 and its DML homologs possess a discontinuous catalytic domain that is unprecedented among known DNA glycosylases.     

Seasonal pattern of Alternaria airborne spores in Santiago de Chile,Chile (2005–2015 period): first Alternaria spore calendar

Since Alternaria is an important aeroallergen in temperate areas of the world, this study was undertaken in order to provide the first results obtained about the seasonal regimen of Alternaria airborne spores in the atmosphere of Santiago de Chile (Chile), for a period of 10 years (2005–2015), which has led to the construction of the first calendar for the city. Furthermore, the periods of maximum presence of these particles in the air were determined together with those days in which the threshold levels set up for the development of clinical symptoms were reached and/or surpassed. The annual spore integral varied between 4077 spores/m³ registered in 2013–2014 and 6824 spores/m³ in 2010–2011, with a main spore season from mid-winter (mid-July/mid-August) to the end of the autumn (June). Daily peaks were mainly detected in spring or autumn seasons but even in winter, although without surpassing 65 spores/m³ in any case.

     

Participation of Na+/K+-ATPase and aquaporins in the uptake of water during moult processes in the shrimp Palaemon argentinus (Nobili, 1901)

Journal of Comparative Physiology B - Due to the presence of the exoskeleton, the moult cycle is a required event in the life of crustaceans. In order for the exoskeleton to be replaced, it is...     

The Cost of Being Fijian in the United Kingdom

This paper is the first within Fijian migration studies to discuss why indigenous Fijians migrate to the United Kingdom (UK) and the socio-economic challenges they face. The majority of these Fijians form a well-organised community based on similar principles as in Fiji (kinship, church, and chieftainship) and do their utmost to live ‘in the Fijian way’ (na ivakarau ni bula vakaviti), a lifestyle also known as living ‘in the manner of the land’ (i tovo vakavanua). I argue this way of life is a central aspect of being a Fijian person, which is characterised, amongst other things, by supporting kin as part of one's kinship obligations in the form of exchange and tribute. The tributes Fijian migrants make are predominantly in the form of services, goods, and especially monetary contributions towards church, communal, and ritual events to both kin in Fiji and in the UK. These monetary contributions regularly interfere with payments, such as utility bills and car insurances. As a consequence, electricity and phone lines are cut or cars are towed away. In Fiji, migrated relatives and friends are thought of as being millionaires, but this article illustrates that the reality is very different. Living costs in the UK are high and prioritising which bills to pay, how much one should contribute to church, communal, and ceremonial events, and how much money to remit to kin in Fiji can be very stressful. I discuss the pressures and motivation for these decisions in this article.     

4-Phenylbutyrate Attenuates the ER Stress Response and Cyclic AMP Accumulation in DYT1 Dystonia Cell Models

Dystonia is a neurological disorder in which sustained muscle contractions induce twisting and repetitive movements or abnormal posturing. DYT1 early-onset primary dystonia is the most common form of hereditary dystonia and is caused by deletion of a glutamic acid residue (302/303) near the carboxyl-terminus of encoded torsinA. TorsinA is localized primarily within the contiguous lumen of the endoplasmic reticulum (ER) and nuclear envelope (NE), and is hypothesized to function as a molecular chaperone and an important regulator of the ER stress-signaling pathway, but how the mutation in torsinA causes disease remains unclear. Multiple lines of evidence suggest that the clinical symptoms of dystonia result from abnormalities in dopamine (DA) signaling, and possibly involving its down-stream effector adenylate cyclase that produces the second messenger cyclic adenosine-3′, 5′-monophosphate (cAMP). Here we find that mutation in torsinA induces ER stress, and inhibits the cyclic adenosine-3′, 5′-monophosphate (cAMP) response to the adenylate cyclase agonist forskolin. Both defective mechanins are corrected by the small molecule 4-phenylbutyrate (4-PBA) that alleviates ER stress. Our results link torsinA, the ER-stress-response, and cAMP-dependent signaling, and suggest 4-PBA could also be used in dystonia treatment. Other pharmacological agents known to modulate the cAMP cascade, and ER stress may also be therapeutic in dystonia patients and can be tested in the models described here, thus supplementing current efforts centered on the dopamine pathway.