Erratum to: Exogenous Adipokine Peptide Resistin Protects Against Focal Cerebral Ischemia/Reperfusion Injury in Mice

Neurochemical Research -     

Developing a Novel Gene-Delivery Vector System Using the Recombinant Fusion Protein of Pseudomonas Exotoxin A and Hyperthermophilic Archaeal Histone HPhA

Non-viral gene delivery system with many advantages has a great potential for the future of gene therapy. One inherent obstacle of such approach is the uptake by endocytosis into vesicular compartments. Receptor-mediated gene delivery method holds promise to overcome this obstacle. In this study, we developed a receptor-mediated gene delivery system based on a combination of the Pseudomonas exotoxin A (PE), which has a receptor binding and membrane translocation domain, and the hyperthermophilic archaeal histone (HPhA), which has the DNA binding ability. First, we constructed and expressed the rPE-HPhA fusion protein. We then examined the cytotoxicity and the DNA binding ability of rPE-HPhA. We further assessed the efficiency of transfection of the pEGF-C1 plasmid DNA to CHO cells by the rPE-HPhA system, in comparison to the cationic liposome method. The results showed that the transfection efficiency of rPE-HPhA was higher than that of cationic liposomes. In addition, the rPE-HPhA gene delivery system is non-specific to DNA sequence, topology or targeted cell type. Thus, the rPE-HPhA system can be used for delivering genes of interest into mammalian cells and has great potential to be applied for gene therapy.     

Sequence of an operon containing a novel δ-endotoxin gene from Bacillus thuringiensis

An insect larval toxin designated CryII is produced by several subspecies of Bacillus thuringiensis and differs from the other major delta-endotoxins in these bacteria in its size, toxicity profile and presence as part of an operon with three open reading frames (ORF). Such an operon from a novel B. thuringiensis isolate has been cloned and differs from one previously characterized in the following ways: (a) the size and number of amino acid repeats in one of the ORFs; (b) the smaller size of the CryII protoxin and the presence of a unique 110-kDa CryII-related antigen; and (c) high larvicidal activity for a particular Lepidopteran but low activity for a Dipteran. Various subclones of this operon were introduced into a plasmid-free B. thuringiensis strain and only the cryII gene was found to be necessary for protoxin accumulation.     

Cancer risk from chronic exposures to chemicals and radiation: a comparison of the toxicological reference value with the radiation detriment

This article aims at comparing reference methods for the assessment of cancer risk from exposure to genotoxic carcinogen chemical substances and to ionizing radiation. For chemicals, cancer potency is expressed as a toxicological reference value (TRV) based on the most sensitive type of cancer generally observed in animal experiments of oral or inhalation exposure. A dose–response curve is established by modelling experimental data adjusted to apply to human exposure. This leads to a point of departure from which the TRV is derived as the slope of a linear extrapolation to zero dose. Human lifetime cancer risk can then be assessed as the product of dose by TRV and it is generally considered to be tolerable in a 10^–6–10^–4 range for the public in a normal situation. Radiation exposure is assessed as an effective dose corresponding to a weighted average of energy deposition in body organs. Cancer risk models were derived from the epidemiological follow-up of atomic bombing survivors. Considering a linear-no-threshold dose-risk relationship and average baseline risks, lifetime nominal risk coefficients were established for 13 types of cancers. Those are adjusted according to the severity of each cancer type and combined into an overall indicator denominated radiation detriment. Exposure to radiation is subject to dose limits proscribing unacceptable health detriment. The differences between chemical and radiological cancer risk assessments are discussed and concern data sources, extrapolation to low doses, definition of dose, considered health effects and level of conservatism. These differences should not be an insuperable impediment to the comparison of TRVs with radiation risk, thus opportunities exist to bring closer the two types of risk assessment.

     

Microbial Symbionts Accelerate Wound Healing via the Neuropeptide Hormone Oxytocin

Wound healing capability is inextricably linked with diverse aspects of physical fitness ranging from recovery after minor injuries and surgery to diabetes and some types of cancer. Impact of the microbiome upon the mammalian wound healing process is poorly understood. We discover that supplementing the gut microbiome with lactic acid microbes in drinking water accelerates the wound-healing process to occur in half the time required for matched control animals. Further, we find that Lactobacillus reuteri enhances wound-healing properties through up-regulation of the neuropeptide hormone oxytocin, a factor integral in social bonding and reproduction, by a vagus nerve-mediated pathway. Bacteria-triggered oxytocin serves to activate host CD4+Foxp3+CD25+ immune T regulatory cells conveying transplantable wound healing capacity to naive Rag2-deficient animals. This study determined oxytocin to be a novel component of a multi-directional gut microbe-brain-immune axis, with wound-healing capability as a previously unrecognized output of this axis. We also provide experimental evidence to support long-standing medical traditions associating diet, social practices, and the immune system with efficient recovery after injury, sustained good health, and longevity.     

Cephalidiosus: A replacement name for Stenotrachelus (Hemiptera: Tingidae)

Cephalidiosus is proposed as a replacement name for Stenotrachelus Guilbert, a genus of Tingidae from New Caledonia. New combinations are Cephalidiosus megapharsus (Guilbert) and Cephalidiosus mesopharsus (Guilbert).     

Comparing models and observations of shelf plankton

In a previous paper (Solow and Steele, J. Plankton Res., 17,1995), the differences between variability in zooplankton biomassand in copepod stage structure were demonstrated using datafrom the northern North Sea. Here, a model is used to describethe underlying demographic processes and the effects of interannualphysical variability. Comparison of output with observationscan test the theory and so help to reconcile the apparent contradictionbetween great variability and persistence in these populations.     

Insights into protective effects of medium additives on animal cells under fluid stresses: the hydrophobic interactions

Animal cells in suspension culture can suffer severe mechanical damage from bursting gas bubbles or other hydrodynamic force sources. Certain chemical additives in the culture media, particularly some surface-active chemicals, can effectively protect animal cells against such damage. Previously we proposed that the protective effect is associated with the adsorption of the additives in the cell membrane through hydrophobic binding of the surface-active molecules to the membrane. Adsorption of the additives to the cell membrane may lead to decreased hydrophobicity of the cell surface, thus eliminating cell adhesion to bubbles and reducing cell damage from bursting bubbles. In this study, we measured the hydrophobicity of two insect cell lines based on cell adhesion to hydrocarbon phase and its influence by surface-active chemicals, Pluronic F68, a methylcellulose and a polyethylene glycol. The experimental results showed strong support for the aforecited cell protection mechanism.