Measurement of Ensemble TRPV1 Ion Channel Currents Using Droplet Bilayers

Electrophysiological characterization of ion channels is useful for elucidation of channel function as well as quantitative assessment of pharmaceutical effects on ion channel conductance. We used droplet bilayers to measure ensemble ion channel currents from membrane preparations made from TRPV1-expressing HEK cells. Conductance measurements showed rectification, activation by acid and capsaicin, and inhibition by capsazepine, SB 452533, and JNJ 17293212. We also quantitatively measured concentration-dependent inhibition of channel conductance through determination of capsazepine IC₅₀ in agreement with previously published studies using patch clamp. These results, combined with the reduced apparatus and material requirements of droplet bilayers, indicate that this platform could be used for study of other physiologically relevant ion channels.     

Persistence and efficacy of a Beauveria bassiana biopesticide against the house fly,Musca domestica,on typical structural substrates of poultry houses

Entomopathogenic fungi, such as Beauveria bassiana, offer potential for use as biopesticides for control of house flies in poultry production facilities. This study evaluates persistence and efficacy of oil-formulated B. bassiana conidia against adult house flies on a range of structural substrates commonly found in poultry houses. Exposure of flies to fungal-treated surfaces produced high levels of infection leading up to 100% mortality in 6–10 days. However, the infectivity of the spray residues declined rapidly within 1 or 2 weeks following repeated fly exposures. Investigations showed that, in the absence of flies, conidia remained viable on test surfaces for up to 3 months regardless of substrate type, application method or fungal production batch. Rather, it was the presence of flies themselves that was responsible for reducing persistence. The exact mechanisms remain unclear but involve a combination of physical removal and chemical deactivation, with decay rates increasing at higher fly densities. While the rapid decay could pose a challenge for operational use, the results suggest it might be possible to tailor treatment frequencies to fly densities with, for example, weekly applications at high fly densities and longer intervals when populations decline. Further research is needed to determine persistence in semifield and field settings and to quantify the influence of fly densities under natural exposure conditions.     

Comparison of walking parameters obtained from the young,elderly and adults with support

Data mining techniques are highly useful in the study of various medical signals and images in order to obtain useful information to better predict the diagnosis or prognosis or treatment options for the patient. Study of the human walking pattern helps us understand the variability of motion during activities such as high performance walking and normal walking. A comparison of the parameters quantifying this variability in motion in normal young and elderly subjects and the subjects who need support will aid in better understanding of the relationship among walking patterns, age and disabilities. In this study, we measured the tri-axial acceleration along three directions: anteroposterior, lateral and vertical. We also measured gyrational pitch, roll and yaw. These parameters were obtained using sensors attached to the back, left thigh and right thigh of the three classes of subjects (normal, elderly and adults with support) during the three types of exercises: 10-m normal walk, 10-m high performance walk and stepping. These recorded signals were then subjected to wavelet packet decomposition, and three entropies, namely approximate entropy and two bispectral entropies, were obtained from the resultant wavelet coefficients. On analysing these entropies, we could observe the following: (1) the entropy steadily decreases with the increase in age and with the presence of impairments, and (2) the entropy decreases among all the three types of exercises, namely normal walking and high performance walking. We feel that the results of this work can help in the design of supporting devices for elderly subjects.     

Human amnion epithelial cells modulate hyperoxia-induced neonatal lung injury in mice

Background aimsHuman amnion epithelial cells (hAECs) prevent pulmonary inflammation and injury in fetal sheep exposed to intrauterine lipopolysaccharide. We hypothesized that hAECs would similarly mitigate hyperoxia-induced neonatal lung injury.MethodsNewborn mouse pups were randomized to either normoxia (inspired O₂ content (FiO₂) = 0.21, n = 60) or hyperoxia (FiO₂ = 0.85, n = 57). On postnatal days (PND) 5, 6 and 7, hAECs or sterile saline (control) was administered intraperitoneally. All animals were assessed at PND 14.ResultsHyperoxia was associated with lung inflammation, alveolar simplification and reduced postnatal growth. Administration of hAECs to hyperoxia-exposed mice normalized body weight and significantly attenuated some aspects of hyperoxia-induced lung injury (mean linear intercept and septal crest density) and inflammation (interleukin-1α, interleukin-6, transforming growth factor-β and platelet-derived growth factor-β). However, hAECs did not significantly alter changes to alveolar airspace volume, septal tissue volume, tissue-to-airspace ratio, collagen content or leukocyte infiltration induced by hyperoxia.ConclusionsIntraperitoneal administration of hAECs to neonatal mice partially reduced hyperoxia-induced lung inflammation and structural lung damage. These observations suggest that hAECs may be a potential therapy for neonatal lung disease.     

The microtubule depolymerizing agent naphthazarin induces both apoptosis and autophagy in A549 lung cancer cells

Naphthazarin (DHNQ, 5,8-dihydroxy-l,4-naphthoquinone) is a naturally available 1,4-naphthoquinone derivatives. In this study, we focused on elucidating the cytotoxic mechanism of naphthazarin in A549 non-small cell lung carcinoma cells. Naphthazarin reduced the A549 cell viability considerably with an IC₅₀ of 16.4 ± 1.6 μM. Naphthazarin induced cell death in a dose- and time-dependent manner by activating apoptosis and autophagy pathways. Specifically, we found naphthazarin inhibited the PI3K/Akt cell survival signalling pathway, measured by p53 and caspase-3 activation, and PARP cleavage. It also resulted in an increase in the ratio of Bax/Bcl2 protein levels, indicating activation of the mitochondrial apoptotic pathway. Similarly naphthazarin triggered LC3II expression and induced autophagic flux in A549 cells. We demonstrated further that naphthazarin is a microtubule inhibitor in cell-free system and in A549 cells. Naphthazarin treatment depolymerized interphase microtubules and disorganised spindle microtubules and the majority of cells arrested at the G₂/M transition. Together, these data suggest that naphthazarin, a microtubule depolymerizer which activates dual cell death machineries, could be a potential novel chemotherapeutic agent.     

Novel oxazine skeletons as potential antiplasmodial active ingredients: Synthesis, in vitro and in vivo biology of some oxazine entities produced via cyclization of novel chalcone intermediates

A novel series of 6-(2-chloroquinolin-3-yl)-4-substituted-phenyl-6H-1,3-oxazin-2-amines were synthesized and evaluated for in vitro antimalarial efficacy against chloroquine sensitive (MRC-02) as well as chloroquine resistant (RKL9) strains of Plasmodium falciparum. The activity tested was at nanomolar concentration. β-Hematin formation inhibition activity (BHIA(50)) of oxazines were determined and correlated with antimalarial activity. A reasonably good correlation (r?=?0.49 and 0.51, respectively) was observed between antimalarial activity (IC(50)) and BHIA(50). This suggests that antimalarial mode of action of these compounds seems to be similar to that of chloroquine and involves the inhibition of hemozoin formation. Some of the compounds were showing better antimalarial activity than chloroquine against resistant strain of P. falciparum and were also found to be active in the in vivo experiment.     

Special issue: engineering toxins for 21st-century therapies: introduction

This special issue on 'Engineering toxins for 21st century therapies' provides a critical review of the current state of multifaceted aspects of toxin research by some of the leading researchers in the field. It also highlights the clinical potential and challenges for development of novel biologics based on engineered toxin derived products.