496 research outputs found
Verified and potential pathogens of predatory mites (Acari: Phytoseiidae)
Several species of phytoseiid mites (Acari: Phytoseiidae), including species of the genera Amblyseius, Galendromus, Metaseiulus, Neoseiulus, Phytoseiulus and Typhlodromus, are currently reared for biological control of various crop pests and/or as model organisms for the study of predator¿prey interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their host or alter their reproduction and behaviour. Potential and verified pathogens have been reported for phytoseiid mites during the past 25 years. The present review provides an overview, including potential pathogens with unknown host effects (17 reports), endosymbiotic Wolbachia (seven reports), other bacteria (including Cardinium and Spiroplasma) (four reports), cases of unidentified diseases (three reports) and cases of verified pathogens (six reports). From the latter group four reports refer to Microsporidia, one to a fungus and one to a bacterium. Only five entities have been studied in detail, including Wolbachia infecting seven predatory mite species, other endosymbiotic bacteria infecting Metaseiulus (Galendromus, Typhlodromus) occidentalis (Nesbitt), the bacterium Acaricomes phytoseiuli infecting Phytoseiulus persimilis Athias-Henriot, the microsporidium Microsporidium phytoseiuli infecting P. persimilis and the microsporidium Oligosproridium occidentalis infecting M. occidentalis. In four cases (Wolbachia, A. phytoseiuli, M. phytoseiuli and O. occidentalis) an infection may be connected with fitness costs of the host. Moreover, infection is not always readily visible as no obvious gross symptoms are present. Monitoring of these entities on a routine and continuous basis should therefore get more attention, especially in commercial mass-production. Special attention should be paid to field-collected mites before introduction into the laboratory or mass rearing, and to mites that are exchanged among rearing facilities. However, at present general pathogen monitoring is not yet practical as effects of many entities are unknown. More research effort is needed concerning verified and potential pathogens of commercially reared arthropods and those used as model organisms in research
Prognostic Threshold for Circulating Tumor Cells in Patients With Pancreatic and Midgut Neuroendocrine Tumors
BACKGROUND: Circulating tumour cells (CTCs) are detectable in patients with NET and are accurate prognostic markers although the optimum threshold has not been defined. OBJECTIVE: To define optimal prognostic CTC threshold in pancreatic and midgut NET. PATIENTS AND METHODS: CellSearch was used to enumerate CTCs in 199 patients with metastatic pancreatic (PanNET) (90) or midgut NET (109). Patients were followed for progression free survival (PFS) and overall survival (OS) for a minimum of 3 years or until death. RESULTS: AUROC for progression at 12 months in PanNET and midgut NET identified the optimal CTC threshold as ≥1 and ≥2 respectively. In multivariate logistic regression analysis, these thresholds were predictive for 12 month progression with OR of 6.69 (p< 0.01) for PanNET and 5.88 (p<0.003) for midgut. The same thresholds were found to be optimal for predicting death at 36 months with an OR of 2.87 (p< 0.03) and 5.09 (p<0.005) for PanNET and midgut NET respectively. In multivariate Cox hazard regression analysis for PFS in PanNET, ≥ 1 CTC had HR 2.6 (p <0.01) whilst ≥ 2 CTCs had HR 2.25 (p < 0.01) in midgut NET. In multivariate analysis OS in PanNET, ≥ 1 CTC had HR 3.16 (p < 0.01) and in midgut NET, ≥ 2 CTCs had HR of 1.73 (p < 0.06). CONCLUSIONS: The optimal CTC threshold to predict PFS and OS in metastatic PanNET and midgut NET is 1 and 2, respectively. These thresholds can be used to stratify patients in clinical practice and clinical trials
Comparative genomics of the major parasitic worms
Parasitic nematodes (roundworms) and platyhelminths (flatworms) cause debilitating chronic infections of humans and animals, decimate crop production and are a major impediment to socioeconomic development. Here we report a broad comparative study of 81 genomes of parasitic and non-parasitic worms. We have identified gene family births and hundreds of expanded gene families at key nodes in the phylogeny that are relevant to parasitism. Examples include gene families that modulate host immune responses, enable parasite migration though host tissues or allow the parasite to feed. We reveal extensive lineage-specific differences in core metabolism and protein families historically targeted for drug development. From an in silico screen, we have identified and prioritized new potential drug targets and compounds for testing. This comparative genomics resource provides a much-needed boost for the research community to understand and combat parasitic worms
Safety and efficacy of maraviroc (MVC) combined with multiple different therapeutic agents in highly treatment-experienced (TE) patients in Brazil
Potent and Broad-Spectrum Antimicrobial Activity of Analogs from the Scorpion Peptide Stigmurin
Scorpion venom constitutes a rich source of biologically active compounds with high potential for therapeutic and biotechnological applications that can be used as prototypes for the design of new drugs. The aim of this study was to characterize the structural conformation, evaluate the antimicrobial activity, and gain insight into the possible action mechanism underlying it, for two new analog peptides of the scorpion peptide Stigmurin, named StigA25 and StigA31. The amino acid substitutions in the native sequence for lysine residues resulted in peptides with higher positive net charge and hydrophobicity, with an increase in the theoretical helical content. StigA25 and StigA31 showed the capacity to modify their structural conformation according to the environment, and were stable to pH and temperature variation-results similar to the native peptide. Both analog peptides demonstrated broad-spectrum antimicrobial activity in vitro, showing an effect superior to that of the native peptide, being non-hemolytic at the biologically active concentrations. Therefore, this study demonstrates the therapeutic potential of the analog peptides from Stigmurin and the promising approach of rational drug design based on scorpion venom peptide to obtain new anti-infective agents.publishersversionpublishe
Structural assessment, toxicity, and increased antimicrobial activity
Scorpion venom is a rich source of biologically active components and various peptides with high-potential therapeutic use that have been characterized for their antimicrobial and antiproliferative activities. Stigmurin is a peptide identified from the Tityus stigmurus venom gland with high antibacterial and antiproliferative activities and low toxicity. Amino acid substitutions in peptides without a disulfide bridge sequence have been made with the aim of reducing their toxicity and increasing their biological activities. The purpose of this study was to evaluate the structural conformation and structural stability, as well as antimicrobial, antiproliferative, and hemolytic activities of two peptide analogs to Stigmurin, denominated StigA6 and StigA16. In silico analysis revealed the α-helix structure for both analog peptides, which was confirmed by circular dichroism. Data showed that the net charge and hydrophobic moment of the analog peptides were higher than those for Stigmurin, which can explain the increase in antimicrobial activity presented by them. Both analog peptides exhibited activity on cancerous cells similar to the native peptide; however, they were less toxic when tested on the normal cell line. These results reveal a potential biotechnological application of the analog peptides StigA6 and StigA16 as prototypes to new therapeutic agents.publishersversionpublishe
Effects of Rio de Janeiro Ar Livre program on the autonomy of octogenarian elderly women
With the increase in life expectancy, it is important to acknowledge the impact of health promotion programs on the elderly. The aimed of this study was to evaluate the influence of the Rio de Janeiro Ar Livre physical program on the functional autonomy of octogenarian elderly women´s. To this end, elderly women´s from 19 Rio de Janeiro Ar Livre program gyms were selected for the experimental group (EG) (n=23; 82.57±3.78 years), and for the Control Group (CG) (n=17; 82.88±2.23 years) from the attending cohabitation houses of the City of Rio de Janeiro. To access the functional autonomy was used Rikli and Jones (1999) protocol in two times separated by (28 weeks). It was observed in the EG a significant (p=0.010) increase in Upper limbs' strength test (13.00±3.41 to 15.09±3.60 times, pre and post innervation, respectively) and a significant (p=0.002) increase in 2 minutes Step test in the CG (36.59±15.00 to 47.24±10.96 times, pre and post, respectively). However, any significant differences between groups were observed in all variables analysed. Based in the present data we can conclude that the training program was only effective in the promotions of the functional strength of the upper limbs and to maintain the functional autonomy of octogenarian elderly women
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