Unexpected multivalent display of proteins by temperature triggered self-assembly of elastin-like polypeptide block copolymers

We report herein the unexpected temperature triggered self-assembly of proteins fused to thermally responsive elastin-like polypeptides (ELPs) into spherical micelles. A set of six ELP block copolymers (ELP(BC)) differing in hydrophilic and hydrophobic block lengths were genetically fused to two single domain proteins, thioredoxin (Trx) and a fibronectin type III domain (Fn3) that binds the α(v)β(3) integrin. The self-assembly of these protein-ELP(BC) fusions as a function of temperature was investigated by UV spectroscopy, light scattering, and cryo-TEM. Self-assembly of the ELP(BC) was unexpectedly retained upon fusion to the two proteins, resulting in the formation of spherical micelles with a hydrodynamic radius that ranged from 24 to 37 nm, depending on the protein and ELP(BC). Cryo-TEM images confirmed the formation of spherical particles with a size that was consistent with that measured by light scattering. The bioactivity of Fn3 was retained when presented by the ELP(BC) micelles, as indicated by the enhanced uptake of the Fn3-decorated ELP(BC) micelles in comparison to the unimer by cells that overexpress the α(v)β(3) integrin. The fusion of single domain proteins to ELP(BC)s may provide a ubiquitous platform for the multivalent presentation of proteins.     

Efficacy of core stability training on upper extremity performance in collegiate athletes

Objective:To determine the efficacy of a five-week core stability training program for collegiate athletes on upper extremity performance measures.Methods:Seventy healthy collegiate athletes (age 21.6±1.7years; height 175±4.63 cm; body mass 65.31±5.63 kg) were randomly allocated to experimental (n=35) and control group (n=35). The experimental group has undergone a five-week core stabilisation protocol (three days /week) and regular training, whereas the control group maintained their regular training. The upper quarter Y balance test (UQ-YBT) and Functional throwing performance index (FTPI) were assessed pre and post-training.Results:The results of mixed ANOVA show that there was a significant interaction between time and group variables on YBT (p<0.001, η_p² =0.759) and FTPI (p<0.001, η_p² =0.411) after five weeks of core stability training. Statistically, significant improvement was shown in YBT (mean change=15.2, p<0.001) and FTPI (mean change=14.4, p<0.001) in the experimental group; however, there was no significant change observed in both outcomes in the control groups.Conclusion:After five weeks of core stabilisation training program, the measures of UQ-YBT and FTPI were improved, thus advocating the use of a core stabilisation training program among collegiate athletes to enhance their upper extremity performance.     

Noninvasive Digital Detection of Fetal DNA in Plasma of 4-Week-Pregnant Women following In Vitro Fertilization and Embryo Transfer

The discovery of cell-free fetal DNA (cfDNA) circulating in the maternal blood has provided new opportunities for noninvasive prenatal diagnosis (NIPD). However, the extremely low levels of cfDNA within a high background of the maternal DNA in maternal circulation necessitate highly sensitive molecular techniques for its reliable use in NIPD. In this proof of principle study, we evaluated the earliest possible detection of cfDNA in the maternal plasma by a bead-based emulsion PCR technology known as BEAMing (beads, emulsion, amplification, magnetics). Blood samples were collected from in vitro fertilization (IVF) patients at 2 to 6 weeks following embryo transfer (i.e., 4 to 8 week pregnancies) and plasma DNA was extracted. The genomic regions of both X and Y chromosome-specific sequences (AMELX and AMELY) were concurrently amplified in two sequential PCRs; first by conventional PCR then by BEAMing. The positive beads either for AMELX or AMELY gene sequences were counted by a flow cytometer. Our results showed that the pregnancies yielding boys had significantly higher plasma AMELY gene fractions (0.512 ± 0.221) than the ones yielding girls (0.028 ± 0.003) or non-pregnant women (0.020 ± 0.005, P= 0.0059). Here, we clearly demonstrated that the BEAMing technique is capable of reliably detecting cfDNA in the blood circulation of 4-week-pregnant women, which is only two weeks after the embryo transfer. BEAMing technique can also be used to early detect fetal DNA alterations in other pregnancy-associated disorders.     

Improvement of Photorhabdus temperata bioinsecticides production in low‐cost media through adequate fermentation technology

To develop a cost effective process for bioinsecticides production by Photorhabdus temperata, dissolved oxygen (DO) requirements were investigated in both the complex and the optimized media using diluted seawater as a source of micronutrients. By varying DO concentrations, tolerance to hydrogen peroxide was shown to be medium dependant. Indeed, P. temperata cells grown in the complex medium, exhibited higher tolerance than cells grown in the optimized medium (OM). Tolerance to H₂O₂ was shown to be related to intracellular reactive oxygen species (ROS) accumulation during soya bean meal or glucose assimilation, as shown by flow cytometry analysis. To avoid oxidative stress damages in P. temperata cells cultured in the OM, DO concentration should be constant 50% saturation throughout the fermentation. However, a DO‐shift control strategy was demonstrated to be beneficial for P. temperata bioinsecticide production in the complex medium. By using such a strategy biomass, culturability, and oral toxicity reached 16.5 × 10⁸, 1.15 × 10⁸ cells/mL and 64.2%, respectively, thus was 16.19, 26.37, and 12.2% more than in the cultures carried out at a constant 50% saturation. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012     

A new drug-release method using the Staudinger ligation

Many drugs induce severe side-effects caused by their lack of selectivity. One way to overcome this problem is to design a specific system which releases a free drug in a controlled manner. Herein we describe a new way to liberate a drug from a prodrug using the Staudinger ligation as the trigger.     

Taxonomy and distribution of fresh water Ostracoda from Socotra Island,Yemen

Eleven species belonging to ten genera of fresh water Ostracoda, have been identified from thirteen sediment samples collected from the bottom of permanent streams running along the N-NE part of Socotra Island. The fauna shows close affinity with the S-E African and S-E Asian assemblages, with interesting findings regarding the Palearctic Limnocythere stationis Vávra, 1891. The taxonomy and geographic distribution of the fauna are here discussed in detail.     

Buspirone attenuated methotrexate-induced hippocampal toxicity in rats by regulating Nrf2/HO-1, PPAR-γ, NF-κB/nNOS,and ROS/NLRP3/caspase-1 signaling pathways

Methotrexate (MTX) is a chemotherapeutic agent widely used to treat a variety of tumors. Nonetheless, MTX-induced hippocampal neurotoxicity is a well-defined dose-limiting adverse effect that limits clinical utility. Proinflammatory cytokine production and oxidative stress are possible mechanisms for MTX-induced neurotoxicity. Buspirone (BSP), a partial agonist of the 5-HT1a receptor (5-HT1aR), has emerged as an anxiolytic drug. BSP has been shown to possess antioxidant and anti-inflammatory effects. The current study investigated BSP's potential anti-inflammatory and antioxidant effects in attenuating MTX-induced hippocampal toxicity. Rats received either BSP (1.5 mg/kg) orally for 10 days and MTX (20 mg/kg) i.p. on Day 5. BSP administration markedly protected hippocampal neurons from drastic degenerated neuronal changes induced by MTX. BSP significantly attenuated oxidative injury by downregulating Kelch-like ECH-associated protein 1 expression while potently elevating hippocampal Nrf2, heme oxygenase-1, and peroxisome proliferator-activated receptor expression. BSP dampened inflammation by reducing NO₂⁻, tumor necrosis factor-alpha, IL-6, and interleukin 1 beta levels mediated by downregulating NF-κB and neuronal nitric oxides synthase expression. Moreover, BSP potently counteracted hippocampal pyroptosis by downregulating NLRP3, ASC, and cleaved-caspase-1 proteins. Therefore, BSP may represent a promising approach to attenuate neurotoxicity in patients receiving MTX.     

Fluorinated tranylcypromine analogues as inhibitors of lysine-specific demethylase 1 (LSD1, KDM1A)

We report a series of tranylcypromine analogues containing a fluorine in the cyclopropyl ring. A number of compounds with additional m- or p-substitution of the aryl ring were micromolar inhibitors of the LSD1 enzyme. In cellular assays, the compounds inhibited the proliferation of acute myeloid leukemia cell lines. Increased levels of the biomarkers H3K4me2 and CD86 were consistent with LSD1 target engagement.     

Chromosomal abnormalities: a potential quality issue for cloned cattle embryos

Nuclear transfer in cattle is associated with high levels of embryonic mortality and often with congenital malformation. Chromosomal abnormalities are a well-known cause of pregnancy failure and congenital malformation in humans, but their relative contribution to pregnancy failure and congenital malformation in cloned embryos and calves is largely unknown. This paper reviews existing literature on the chromosomal constitution of bovine embryos produced by fertilization in vivo and in vitro, parthenogenetic activation, and nuclear transfer. The published data suggest that chromosomally abnormal cells are common in embryos; however, the frequency reported varies with the method of embryo production. The most frequently observed deviation from the diploid karyotype was mixoploidy resulting from aberrant cell division causing polyploidy in a variable proportion of the embryo's cells.