Insulin Reverses D-Glucose–Increased Nitric Oxide and Reactive Oxygen Species Generation in Human Umbilical Vein Endothelial Cells

Vascular tone is controlled by the L-arginine/nitric oxide (NO) pathway, and NO bioavailability is strongly affected by hyperglycaemia-induced oxidative stress. Insulin leads to high expression and activity of human cationic amino acid transporter 1 (hCAT-1), NO synthesis and vasodilation; thus, a protective role of insulin on high D-glucose–alterations in endothelial function is likely. Vascular reactivity to U46619 (thromboxane A₂ mimetic) and calcitonin gene related peptide (CGRP) was measured in KCl preconstricted human umbilical vein rings (wire myography) incubated in normal (5 mmol/L) or high (25 mmol/L) D-glucose. hCAT-1, endothelial NO synthase (eNOS), 42 and 44 kDa mitogen-activated protein kinases (p42/44^mapk), protein kinase B/Akt (Akt) expression and activity were determined by western blotting and qRT-PCR, tetrahydrobiopterin (BH₄) level was determined by HPLC, and L-arginine transport (0–1000 μmol/L) was measured in response to 5–25 mmol/L D-glucose (0–36 hours) in passage 2 human umbilical vein endothelial cells (HUVECs). Assays were in the absence or presence of insulin and/or apocynin (nicotinamide adenine dinucleotide phosphate-oxidase [NADPH oxidase] inhibitor), tempol or Mn(III)TMPyP (SOD mimetics). High D-glucose increased hCAT-1 expression and activity, which was biphasic (peaks: 6 and 24 hours of incubation). High D-glucose–increased maximal transport velocity was blocked by insulin and correlated with lower hCAT-1 expression and SLC7A1 gene promoter activity. High D-glucose–increased transport parallels higher reactive oxygen species (ROS) and superoxide anion (O₂ ^•–) generation, and increased U46619-contraction and reduced CGRP-dilation of vein rings. Insulin and apocynin attenuate ROS and O₂ ^•– generation, and restored vascular reactivity to U46619 and CGRP. Insulin, but not apocynin or tempol reversed high D-glucose–increased NO synthesis; however, tempol and Mn(III)TMPyP reversed the high D-glucose–reduced BH₄ level. Insulin and tempol blocked the high D-glucose–increased p42/44^mapk phosphorylation. Vascular dysfunction caused by high D-glucose is likely attenuated by insulin through the L-arginine/NO and O₂ ^•–/NADPH oxidase pathways. These findings are of interest for better understanding vascular dysfunction in states of foetal insulin resistance and hyperglycaemia.     

A new formulated stable papin-pectin aerosol spray for skin wound healing

A new spray-on topical wound debrider composition consisting of 0.1% w/v papain immobilized in 6% w/v pectin gel was formulated for skin wound healing. The stability of the enzyme activity of this new formulated spray was compared with the 0.1% w/v papain in water solution at the refrigerated temperature of 4 and 75°C. Two aerosol propellants, air and nitrogen, were evaluated for their efficacy. The new formulated spray was then evaluated for its thermal stability under air and N₂ at 75°C. All enzyme activity of papain was measured with a spectrophotometer using casein as a substrate at 37°C and in 0.1 M phosphate buffer at pH 6, as well as trichloral acetic acid to separate the product of casein hydrolysis. All the evaluations showed the new aerosol spray formulation to be far better than the liquid formulation in storage stability and thermal stability at 75°C under atmospheric or higher pressures. The new formulation was tested in a rabbit experiment to evaluate the effectiveness of wound healing. As compared to untreated wound, the formulated spray clearly was superior, yielding a 20% more healing progress in the first 4 days alone.     

Conformation and lytic activity of eumenine mastoparan: a new antimicrobial peptide from wasp venom.

Eumenine mastoparan-AF (EMP-AF) is a novel membrane active tetradecapeptide recently isolated from the venom of solitary wasp, Anterhynchium flavomarginatum micado. It was reported previously that EMP-AF peptide presented low cytolytic activities in human erythrocytes and in RBL-2H3 mast cells. In the present work, we observed that this peptide is able to permeate anionic liposomes, and in less extension also the neutral ones. We present evidences showing that the permeation ability is well correlated with the amount of helical conformation assumed by the peptides in these environments. This peptide also showed a broad-spectrum inhibitory activity against Gram-positive and Gram-negative bacteria. The permeability of liposomes and the antibiotic effect showed a significant reduction when C-terminus was deamidated (in acidic form). The removal of the three first amino acid residues from the N-terminus rendered the peptide inactive both in liposomes and in bacteria. The results suggest that the mechanism of action involves a threshold in the accumulation of the peptide at level of cell membrane.     

Antibiofilm effect of mono-rhamnolipids and di-rhamnolipids on carbon steel submitted to oil produced water

The objective of this study was to compare the potential of mono-rhamnolipids (mono-RML) and di-rhamnolipids (di-RML) against biofilm formation on carbon steel coupons submitted to oil produced water for 14 days. The antibiofilm effect of the RML on the coupons was analyzed by scanning electron microscopy (SEM) and by epifluorescence microscopy, and the contact angle was measured using a goniometer. SEM analysis results showed that all RML congeners had effective antibiofilm action, as well as preliminary anticorrosion evaluation confirmed that all RML congeners prevented the metal deterioration. In more detail, epifluorescence microscopy showed that mono-RML were the most efficient congeners in preventing microorganism's adherence on the carbon steel metal. Image analyses indicate the presence of 15.9%, 3.4%, and <0.1% of viable particles in di-RML, mono/di-RML and mono-RML pretreatments, respectively, in comparison to control samples. Contact angle results showed that the crude carbon steel coupon presented hydrophobic character favoring hydrophobic molecules adhesion. We calculated the theoretical polarity of the RML congeners and verified that mono-RML (log P = 3.63) presented the most hydrophobic character. This had perfect correspondence to contact angle results, since mono-RML conditioning (58.2°) more significantly changed the contact angle compared with the conditioning with one of the most common surfactants used on oil industry (29.4°). Based on the results, it was concluded that rhamnolipids are efficient molecules to be used to avoid biofilm on carbon steel metal when submitted to oil produced water and that a higher proportion of mono-rhamnolipids is more indicated for this application.     

Modeling the Dynamics of Paternal Influences on Children Over the Life Course

Modeling the Dynamics of Paternal Influences on Children over the Life Course Is a heuristic model, which identifies sets of variables that predict father involvement, variables that interact to predict involvement, and variables that influence father characteristics and thereby influence involvement. It also suggests moderators and mediators of pathways from predictors to father involvement and from father involvement to child outcomes. It is a dynamic model, assuming change over the life course, while retaining paternal influences from one developmental period to another. The model is rooted in the extant literature, although it is not circumscribed by that literature. As a heuristic model, it offers a framework from which measurement models can be derived to address research questions of interest.     

Genotoxicity of soil from farmland irrigated with wastewater using three plant bioassays.

Three well known plant bioassays, the Allium root chromosome aberration (AL-RAA) assay, the Tradescantia micronucleus (Trad-MCN) assay, and the Tradescantia stamen hair (Trad-SHM) mutation assay were validated in 1991 by the International Programme on Chemical Safety (IPCS) under the auspices of the World Health Organization, and the United Nations Environment Programme (UNEP). These plant bioassays have proven to be efficient tests for chemical screening and especially for in situ monitoring for genotoxicity of environmental pollutants. As a result of this validation study, standard protocols of these three plant bioassays were used by some of the 11 participating countries in the IPCS to carry on genotoxicity tests on air, water and soil as a follow up activity. In the city of Queretaro, Mexico, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the farm crops, polluting the soil. Potentially the pollutants could reach the food chain. For the above reason, soil irrigated with wastewater was sampled and monitored for the presence of genotoxic agents using the above three bioassays. Extracts from soil samples were made using distilled water and organic solvents by shaking the sample for about 12 h under a relatively low temperature (15-20 degrees C). Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the extracts. Three replicates of each sample were analyzed in each of the three bioassays. Extracts using DMSO, ethanol and distilled water tested positive in the three bioassays and there were no differences for the genotoxicity of the extracts with the different solvents.     

The Vallesian Mammal Turnover: A Late Miocene record of decoupled land-ocean evolution

In Western Europe, the change from the Middle Miocene forest-adapted mammalian faunas to the more open woodland faunas of the later Neogene, took place through an abrupt critical period known as the Vallesian Crisis. The Vallesian Crisis involved the disappearance of most of the forest-adapted elements characterizing the middle Miocene, such as tapirs, rhinoceroses, wet-adapted artiodactyls, hominoids, rodents, and the large carnivores of the families Nimravidae and Amphicyonidae. Detailed analysis in the well-calibrated and mostly complete sequence of the type area of the Vallesian Mammal stage, the Vallès-Penedès Basin (NE Spain), reveals that entries were always above the level of exits during the early Vallesian, reaching a diversity maximum at the end of this time. At 9.75 Ma, the Vallesian Crisis involved a sudden decrease of diversity, caused by high extinction levels, well above the number of entries. This event can be correlated with Mi7, a minor isotopic shift at about 9.6 Ma. The correlation of the Vallesian Crisis with such a minor isotopic shift is in contrast with previous, more significant isotopic shifts which had little ecological effects on the terrestrial ecosystems. This inconsistency between the global climate change inferred from the oceanic record and its effect on the structure of the late Miocene terrestrial ecosystems calls for some caution when inferring direct, linear relationships between climate change and mammalian turnover. In contrast with the Plio-Pleistocene glacial-interglacial dynamics, the effects of this climate forcing seem to have been more complex during Miocene times. An alternative pattern of change can be envisaged by proposing a “House of Cards” effect for the Vallesian Crisis. Increasing diversity levels after a prolonged period of stability enhanced terrestrial ecosystems to evolve into a self-organized critical state, which suddenly dropped after a critical threshold was surpassed. In contrast to other critical periods, the final decline of the Vallesian chronofauna was more dependent on the critical state of the system than on the magnitude of the agent which induced the crisis.     

Caste differences in feeding and trophallaxis in the western drywood termite, Incisitermes minor (Hagen) (Isoptera, Kalotermitidae)

Summary: Differences in feeding and trophallaxis among castes of the western drywood termite, Incisitermes minor (Hagen), were determined using rubidium (Rb) as a tracer. Both 5th- and 6th-instar nymphs and 3rd- and 4th-instar larvae fed directly on Rb-treated paper and acted as both donors and recipients in trophallactic exchanges with other larvae and nymphs, and as donors for soldiers and alates. Soldiers and alates did not feed on Rb-treated paper suggesting that they do not feed directly on wood and are completely dependent on nymphs for their nutritional needs. Larvae paired with Rb-fed nymphs received the greatest amount of Rb suggesting that there may be a hierarchy of trophallaxis in drywood termites. Transfer efficiency, the percentage of the total Rb intake of donors that is passed to the recipients, ranged from 1.1 % (nymphal donors to alate recipients) to 16.6 % (larval donors to nymphal recipients).