Effect of chemotherapy exposure prior to pregnancy on fetal brain tissue and the potential protective role of quercetin

Cyclophosphamide (CYC) and doxorubicin (DOX) are among the most effective and widely used anticancer chemotherapeutic drugs. Potential chemopreventive and chemotherapeutic functions have recently been attributed to flavonoids. We hypothesized that Quercetin (QR) would protect against the toxic effects of chemotherapeutic agents applied prior to pregnancy. Rats were treated with the chemotherapeutic drugs CYC (27 mg/kg) and DOX (1.8 mg/kg) applied in a single intraperitoneal dose once every 3 weeks for 10 weeks. QR was administered at a dose of 10 mg/kg/day by oral gavage. 48 h following the experimental chemotherapy exposure, female rats were transferred to cages containing male rat for mating. Fetal brain tissues were removed from fetuses extracted by cesarean section on the 20th day of gestation for evaluation of antioxidant parameters. A significant increase in superoxide dismutase and malondialdehyde activity was observed in CYC and DOX treatment groups relative to the control group (p < 0.05). Similarly, carnitine acylcarnitine translocase and Glutathione activity was significantly reduced in the CYC and DOX groups relative to the control group (p < 0.05). Our results indicate that the use of chemotherapeutic drugs before pregnancy can result in oxidative damage to fetal brain tissue. Therefore, women who have been exposed to chemotherapy and may become pregnant should be treated with antioxidant compounds such as QR to reduce the risk of damage to fetal brain tissues.     

Therapeutic Use of 3β-[N-(N′,N′-Dimethylaminoethane) Carbamoyl] Cholesterol-Modified PLGA Nanospheres as Gene Delivery Vehicles for Spinal Cord Injury

Gene delivery holds therapeutic promise for the treatment of neurological diseases and spinal cord injury. Although several studies have investigated the use of non-viral vectors, such as polyethylenimine (PEI), their clinical value is limited by their cytotoxicity. Recently, biodegradable poly (lactide-co-glycolide) (PLGA) nanospheres have been explored as non-viral vectors. Here, we show that modification of PLGA nanospheres with 3β-[N-(N′,N′-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) enhances gene transfection efficiency. PLGA/DC-Chol nanospheres encapsulating DNA were prepared using a double emulsion-solvent evaporation method. PLGA/DC-Chol nanospheres were less cytotoxic than PEI both in vitro and in vivo. DC-Chol modification improved the uptake of nanospheres, thereby increasing their transfection efficiency in mouse neural stem cells in vitro and rat spinal cord in vivo. Also, transgene expression induced by PLGA nanospheres was higher and longer-lasting than that induced by PEI. In a rat model of spinal cord injury, PLGA/DC-Chol nanospheres loaded with vascular endothelial growth factor gene increased angiogenesis at the injury site, improved tissue regeneration, and resulted in better recovery of locomotor function. These results suggest that DC-Chol-modified PLGA nanospheres could serve as therapeutic gene delivery vehicles for spinal cord injury.     

Distinct Pools of Non-Glycolytic Substrates Differentiate Brain Regions and Prime Region-Specific Responses of Mitochondria

Many hereditary diseases are characterized by region-specific toxicity, despite the fact that disease-linked proteins are generally ubiquitously expressed. The underlying basis of the region-specific vulnerability remains enigmatic. Here, we evaluate the fundamental features of mitochondrial and glucose metabolism in synaptosomes from four brain regions in basal and stressed states. Although the brain has an absolute need for glucose in vivo, we find that synaptosomes prefer to respire on non-glycolytic substrates, even when glucose is present. Moreover, glucose is metabolized differently in each brain region, resulting in region-specific “signature” pools of non-glycolytic substrates. The use of non-glycolytic resources increases and dominates during energy crisis, and triggers a marked region-specific metabolic response. We envision that disease-linked proteins confer stress on all relevant brain cells, but region-specific susceptibility stems from metabolism of non-glycolytic substrates, which limits how and to what extent neurons respond to the stress.     

Enhancing nicotine vaccine immunogenicity with liposomes

A major liability of existing nicotine vaccine candidates is the wide variation in anti-nicotine immune responses among clinical trial participants. In order to address this liability, significant emphasis has been directed at evaluating adjuvants and delivery systems that confer more robust potentiation of the anti-nicotine immune response. Toward that end, we have initiated work that seeks to exploit the adjuvant effect of liposomes, with or without Toll-like receptor agonist(s). The results of the murine immunization study described herein support the hypothesis that a liposomal nicotine vaccine formulation may provide a means for addressing the immunogenicity challenge.     

Overexpression of AtABCG36 improves drought and salt stress resistance in Arabidopsis

Drought and salt are major abiotic stresses that adversely affect crop productivity. Thus, identification of factors that confer resistance to these stresses would pave way to increasing agricultural productivity. When grown on soil in green house longer than 5 weeks, transgenic Arabidopsis plants that overexpress an ATP‐binding cassette (ABC) transporter, AtABCG36/AtPDR8, produced higher shoot biomass and less chlorotic leaves than the wild‐type. We investigated whether the improved growth of AtABCG36‐overexpressing plants was due to their improved resistance to abiotic stresses, and found that AtABCG36‐overexpressing plants were more resistant to drought and salt stress and grew to higher shoot fresh weight (FW) than the wild‐type. On the contrary, T‐DNA insertional knockout lines were more sensitive to drought stress than wild‐type and were reduced in shoot FW. To understand the mechanism of enhanced salt and drought resistance of the AtABCG36 overexpressing plants, we measured sodium contents and found that AtABCG36 overexpressing plants were lower in sodium content than the wild‐type. Our data suggest that AtABCG36 contributes to drought and salt resistance in Arabidopsis by a mechanism that includes reduction of sodium content in plants.     

Measuring the adhesion limit of fibronectin for fibroblasts with a narrow-gap rotational rheometer

Bioprocess and Biosystems Engineering - We study the adhesion limit of 3T6 fibroblasts, cultured in Dulbecco’s modified Eagle’s medium with 10% fetal bovine serum at 37&nbsp;°C...     

Contribution of interfacial tension changes during cellular interaction to the energy balance

The energetics of cell-cell and cell-substrate interactions has been analyzed in terms of the lyophobic colloid stability theory adapted to biological conditions. Some important differences that exist between lyophobic particles and living cells are recognized and taken into account. The protein-aceous coat exterior to the lipid cell membrane (glycocalyx) is treated as a very thick Stern layer which has a constant electric capacitance. The cell itself is viewed as a fluid droplet due to the semi-fluid state of the cell membrane, and its outer boundary is assumed to have a constant electric charge density. When particles with constant surface charge density interact, their surface potential increases. Then the potential at the lipid-protein interface will also increase, hence the interfacial tension should decrease. The magnitude of the interfacial tension change at the lipid-protein interface occurring during the interaction of cells has been calculated for various thicknesses of the glycocalyx. This term, obtained for cells with a relatively thin proteinaceous coat, was found to dominate the energy balance, making the total energy of interaction negative.     

A multigene molecular phylogenetic assessment of true morels (Morchella) in Turkey

A collection of 247 true morels (Morchella spp.) primarily from the Mediterranean and Aegean Regions of Southern Turkey, were analyzed for species diversity using partial RNA polymerase I (RPB1) and nuclear ribosomal large subunit (LSU) rDNA gene sequences. Based on the result of this initial screen, 62 collections representing the full range of genetic diversity sampled were subjected to multigene phylogenetic species recognition based on genealogical concordance (GCPSR). The 62-taxon dataset consisted of partial sequences from three nuclear protein-coding genes, RNA polymerase I (RPB1), RNA polymerase II (RPB2), translation elongation factor (EF1-α), and partial LSU rDNA gene sequences. Phylogenetic analyses of the individual and combined datasets, using maximum parsimony (MP) and maximum likelihood (ML), yielded nearly fully resolved phylogenies that were highly concordant topologically. GCPSR analysis of the 62-taxon dataset resolved 15 putative phylogenetically distinct species. The early diverging Elata (black morels) and Esculenta Clades (yellow morels) were represented, respectively, by 13 and two species. Because a Latin binomial can be applied with confidence to only one of the 15 species (Morchella semilibera), species were identified by clade (Mel for Elata and Mes for Esculenta) followed by a unique Arabic number for each species within these two clades. Eight of the species within the Elata Clade appear to be novel, including all seven species within the Mel-20-to-31 subclade and its sister designated Mel-25. Results of the present study provide essential data for ensuring the sustainability of morel harvests through the formulation of sound conservation policies.     

In vitro cell-based assay for activity analysis of staphylococcal enterotoxin A in food

Staphylococcal enterotoxins (SEs) are a leading cause of food poisoning and have two separate biological activities; it causes gastroenteritis and functions as a superantigen that activates large numbers of T cells. In vivo monkey or kitten bioassays were developed for analysis of SEs emetic activity. To overcome the inherent limitations of such bioassays, this study describes an in vitro splenocyte proliferation assay based on SEs superantigen activity as an alternative method for measuring the activity of staphylococcal enterotoxin A (SEA). After incubation of splenocytes with SEA, cell proliferation was measured by labeling the proliferating cells' DNA with bromodeoxyuridine (5-bromo-2-deoxyuridine, BrdU) and quantifying the incorporated BrdU by immunohistochemistry. BrdU labeling is shown to be highly correlated with SEA concentration ( R ²=0.99) and can detect 20 pg mL⁻¹ of SEA, which is far more sensitive than most enzyme-linked immunosorbent assays. Our assay can also distinguish between active toxin and inactive forms of the toxin in milk. By applying immunomagnetic beads that capture and concentrate the toxin, our assay was able to overcome matrix interference. These results suggest that our in vitro cell-based assay is an advantageous practical alternative to the in vivo monkey or kitten bioassays for measuring SEA and possibly other SEs activity in food.