Safety, Formulation and In Vitro Antiviral Activity of the Antimicrobial Peptide Subtilosin Against Herpes Simplex Virus Type 1

In the present study, the antiviral properties of the bacteriocin subtilosin against Herpes simplex virus type 1 (HSV-1) and the safety and efficacy of a subtilosin-based nanofiber formulation were determined. High concentrations of subtilosin, the cyclical antimicrobial peptide produced by Bacillus amyloliquefaciens, were virucidal against HSV-1. Interestingly, at non-virucidal concentrations, subtilosin inhibited wild type HSV-1 and aciclovir-resistant mutants in a dose-dependent manner. Although the exact antiviral mechanism is not fully understood, time of addition experiments and western blot analysis suggest that subtilosin does not affect viral multiplication steps prior to protein synthesis. Poly(vinyl alcohol)-based subtilosin nanofibers with a width of 278 nm were produced by the electrospinning process. The retained antimicrobial activity of the subtilosin-based fibers was determined via an agar well diffusion assay. The loading capacity of the fibers was 2.4 mg subtilosin/g fiber, and loading efficiency was 31.6 %. Furthermore, the nanofibers with and without incorporated subtilosin were shown to be non-toxic to human epidermal tissues using an in vitro human tissue model. Taking together these results, subtilosin-based nanofibers should be further studied as a novel alternative method for treatment and/or control of HSV-1 infection.     

Spatial-Orientation Priming Impedes Rather than Facilitates the Spontaneous Control of Hand-Retraction Speeds in Patients with Parkinson’s Disease

Background

Often in Parkinson’s disease (PD) motor-related problems overshadow latent non-motor deficits as it is difficult to dissociate one from the other with commonly used observational inventories. Here we ask if the variability patterns of hand speed and acceleration would be revealing of deficits in spatial-orientation related decisions as patients performed a familiar reach-to-grasp task. To this end we use spatial-orientation priming which normally facilitates motor-program selection and asked whether in PD spatial-orientation priming helps or hinders performance.

Methods

To dissociate spatial-orientation- and motor-related deficits participants performed two versions of the task. The biomechanical version (DEFAULT) required the same postural- and hand-paths as the orientation-priming version (primed-UP). Any differences in the patients here could not be due to motor issues as the tasks were biomechanically identical. The other priming version (primed-DOWN) however required additional spatial and postural processing. We assessed in all three cases both the forward segment deliberately aimed towards the spatial-target and the retracting segment, spontaneously bringing the hand to rest without an instructed goal.

Results and Conclusions

We found that forward and retracting segments belonged in two different statistical classes according to the fluctuations of speed and acceleration maxima. Further inspection revealed conservation of the forward (voluntary) control of speed but in PD a discontinuity of this control emerged during the uninstructed retractions which was absent in NC. Two PD groups self-emerged: one group in which priming always affected the retractions and the other in which only the more challenging primed-DOWN condition was affected. These PD-groups self-formed according to the speed variability patterns, which systematically changed along a gradient that depended on the priming, thus dissociating motor from spatial-orientation issues. Priming did not facilitate the motor task in PD but it did reveal a breakdown in the spatial-orientation decision that was independent of the motor-postural path.     

Pancreatic ductal adenocarcinomas from Mexican patients present a distinct genomic mutational pattern

Molecular Biology Reports - Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in humans, with less than 5% 5-year survival rate. PDAC is characterized by a small number of...     

Organic Codes: A Unifying Concept for Life

Although the knowledge about biological systems has advanced exponentially in recent decades, it is surprising to realize that the very definition of Life keeps presenting theoretical challenges. Even if several lines of reasoning seek to identify the essence of life phenomenon, most of these thoughts contain fundamental problem in their basic conceptual structure. Most concepts fail to identify either necessary or sufficient features to define life. Here, we analyzed the main conceptual frameworks regarding theoretical aspects that have been supporting the most accepted concepts of life, such as (i) the physical, (ii) the cellular and (iii) the molecular approaches. Based on an ontological analysis, we propose that Life should not be positioned under the ontological category of Matter. Yet, life should be better understood under the top-level ontology of “Process”. Exercising an epistemological approach, we propose that the essential characteristic that pervades each and every living being is the presence of organic codes. Therefore, we explore theories in biosemiotics and code biology in order to propose a clear concept of life as a macrocode composed by multiple inter-related coding layers. This way, as life is a sort of metaphysical process of encoding, the living beings became the molecular materialization of that process. From the proposed concept, we show that the evolutionary process is a fundamental characteristic for life’s maintenance but it is not necessary to define life, as many organisms are clearly alive but they do not participate in the evolutionary process (such as infertile hybrids). The current proposition opens a fertile field of debate in astrobiology, epistemology, biosemiotics, code biology and robotics.

     

Colonization of Madagascar periwinkle (Catharanthus roseus), by endophytes encoding gfp marker

This study reports the introduction of gfp marker in two endophytic bacterial strains (Pantoea agglomerans C33.1, isolated from cocoa, and Enterobacter cloacae PR2/7, isolated from citrus) to monitor the colonization in Madagascar perinwinkle (Catharanthus roseus). Stability of the plasmid encoding gfp was confirmed in vitro for at least 72 h of bacterial growth and after the colonization of tissues, under non-selective conditions. The colonization was observed using fluorescence microscopy and enumeration of culturable endophytes in inoculated perinwinkle plants that grew for 10 and 20 days. Gfp-expressing strains were re-isolated from the inner tissues of surface-sterilized roots and stems of inoculated plants, and the survival of the P. agglomerans C33:1gfp in plants 20 days after inoculation, even in the absence of selective pressure, suggests that is good colonizer. These results indicated that both gfp-tagged strains, especially P. agglomerans C33.1, may be useful tools to deliver enzymes or other proteins in plant.     

Neonatal Morphine Administration Leads to Changes in Hippocampal BDNF Levels and Antioxidant Enzyme Activity in the Adult Life of Rats

It is know that repeated exposure to opiates impairs spatial learning and memory and that the hippocampus has important neuromodulatory effects after drug exposure and withdrawal symptoms. Thus, the aim of this investigation was to assess hippocampal levels of BDNF, oxidative stress markers associated with cell viability, and TNF-α in the short, medium and long term after repeated morphine treatment in early life. Newborn male Wistar rats received subcutaneous injections of morphine (morphine group) or saline (control group), 5 μg in the mid-scapular area, starting on postnatal day 8 (P8), once daily for 7 days, and neurochemical parameters were assessed in the hippocampus on postnatal days 16 (P16), 30 (P30), and 60 (P60). For the first time, we observed that morphine treatment in early life modulates BDNF levels in the medium and long term and also modulates superoxide dismutase activity in the long term. In addition, it was observed effect of treatment and age in TNF-α levels, and no effects in lactate dehydrogenase levels, or cell viability. These findings show that repeated morphine treatment in the neonatal period can lead to long-lasting neurochemical changes in the hippocampus of male rats, and indicate the importance of cellular and intracellular adaptations in the hippocampus after early-life opioid exposure to tolerance, withdrawal and addiction.     

Pollination and self-interference in Nothofagus

Interference between male and female functions within a monoecious plant may hinder crossing and decrease seed set. We assessed the probability of self-pollination and the effect of self-pollination on cross-pollination for two self-incompatible species: Nothofagus obliqua and N. nervosa. The probability of self-pollination was studied by tracking the phenologies of staminate and pistillate flowers, including an analysis of stigmatic receptivity. Pure and mixed pollinations were performed in order to evaluate the effect of self-pollination upon cross-pollination. Phenological observations suggest that self-pollination is highly likely in both species. Compared to pure cross-pollination, the application of self-pollination prior to cross-pollination resulted in lower numbers of germinated pollen grains for both species, and also in a lower production of viable seeds in N. nervosa. The low proportion of viable seeds often observed in natural populations of N. obliqua and N. nervosa may be related to self-pollination.     

Biochemical markers of vascular calcification in elderly hemodialysis patients

The increased vascular calcification, cardiovascular morbidity, and mortality in chronic kidney disease (CKD) patients has been associated with disturbances in mineral-bone metabolism. In order to determine markers of the vascular calcification frequently observed in these patients, blood samples of elderly male and female hemodialysis CKD patients were used to measure serum levels of: osteoprotegerin (OPG), total soluble receptor activator of nuclear factor-κB ligand (sRANKL), and fetuin-A by enzyme immunoassay; tartrate-resistant acid phosphatase (TRACP-5b), and bone-specific alkaline phosphatase (BAP) by immunoenzymometric assay; osteocalcin (OC) by ELISA; iPTH by immunoradiometric assay; 25(OH)D₃ and 1,25(OH)₂D₃, by I¹²⁵ radioimmunoassay; and calcium and phosphorus by photometric assay. Serum OPG, BAP, iPTH, phosphorus, and OC levels were higher and serum 25(OH)D₃, 1,25(OH)₂D₃, and fetuin-A levels lower in both male and female CKD patients than in their respective controls. Our results indicate that the bone formation and resorption parameters are altered in elderly male and female hemodialysis CKD patients. These changes may lead to vascular calcifications and cardiovascular complications, given that elevated OPG and OC levels and reduced fetuin-A levels are associated with cardiovascular events.     

Nectar ecology of Datura ferox (Solanaceae): an invasive weed with nocturnal flowers in agro-ecosystems from central Argentina

Plant–pollinator interactions provide highly important ecological functions, and are influenced by floral nectar characteristics. The night blooming Datura ferox is an excellent model to test general hypotheses on the relationship between nectar traits (e.g., nectar secretion patterns, nectar chemical composition), pollinators and reproductive success for invasive, weedy species in highly modified ecosystems as crop fields. We hypothesized an adjustment between nectar composition and secretion dynamics through flower anthesis and the activity and requirements of nocturnal pollinators. Nectar chemical analyses showed low quantities of amino acids and lipids, phenolics, and alkaloids were not detected. D. ferox showed sucrose-dominant nectar with comparable amount of hexoses. Sugar proportions did not vary between populations or during flowering season. Most nectar is secreted before flower opening. Nectar resorption was detected at the end of anthesis. Experimentally drained flowers of both populations increased nectar production up to 50 % in the total amount of sugar per flower compared to control flowers. Nectar standing crop was relatively constant during the flowering season, but differences were detected between populations. Nectar traits of D. ferox would be favoring cross-pollination and maintaining seed production of this weed, since recently open flowers display a higher amount of nectar and they can renew nectar after a pollinator visit or reabsorb it at the end of anthesis. This nectar source may be important for native pollinators considering that human-induced forest fragmentation is related with the impoverishment of native flora from agro-ecosystems.