Prediction of human core body temperature using non-invasive measurement methods

The measurement of core body temperature is an efficient method for monitoring heat stress amongst workers in hot conditions. However, invasive measurement of core body temperature (e.g. rectal, intestinal, oesophageal temperature) is impractical for such applications. Therefore, the aim of this study was to define relevant non-invasive measures to predict core body temperature under various conditions. We conducted two human subject studies with different experimental protocols, different environmental temperatures (10 °C, 30 °C) and different subjects. In both studies the same non-invasive measurement methods (skin temperature, skin heat flux, heart rate) were applied. A principle component analysis was conducted to extract independent factors, which were then used in a linear regression model. We identified six parameters (three skin temperatures, two skin heat fluxes and heart rate), which were included for the calculation of two factors. The predictive value of these factors for core body temperature was evaluated by a multiple regression analysis. The calculated root mean square deviation (rmsd) was in the range from 0.28 °C to 0.34 °C for all environmental conditions. These errors are similar to previous models using non-invasive measures to predict core body temperature. The results from this study illustrate that multiple physiological parameters (e.g. skin temperature and skin heat fluxes) are needed to predict core body temperature. In addition, the physiological measurements chosen in this study and the algorithm defined in this work are potentially applicable as real-time core body temperature monitoring to assess health risk in broad range of working conditions.     

Targeting NADPH Oxidase and Phospholipases A2 in Alzheimer’s Disease

Alzheimer’s disease (AD) is marked by an increase in the production of extracellular beta amyloid plaques and intracellular neurofibrillary tangles associated with a decline in brain function. Increases in oxidative stress are regarded as an early sign of AD pathophysiology, although the source of reactive oxygen species (ROS) and the mechanism(s) whereby beta amyloid peptides (Aβ) impact oxidative stress have not been adequately investigated. Recent studies provide strong evidence for the involvement of NADPH oxidase and its downstream oxidative signaling pathways in the toxic effects elicited by Aβ. ROS produced by NADPH oxidase activate multiple signaling pathways leading to neuronal excitotoxicity and glial cell-mediated inflammation. This review describes recent studies demonstrating the neurotoxic effects of Aβ in conjunction with ROS produced by NADPH oxidase and the downstream pathways leading to activation of cytosolic phospholipase A₂ (PLA₂) and secretory PLA₂. In addition, this review also describes recent studies using botanical antioxidants to protect against oxidative damage associated with AD. Investigating the metabolic and signaling pathways involving Aβ NADPH oxidase and PLA₂ can help understand the mechanisms underlying the neurodegenerative effects of oxidative stress in AD. This information should provide new therapeutic approaches for prevention of this debilitating disease.     

Synthesis and biological evaluation of retinoid-chalcones as inhibitors of colon cancer cell growth

Based on the observed anticancer activity of chalcones and retinoids, a novel class of retinoid-chalcone hybrids was designed and synthesized. As part of our ongoing studies to discover natural product based anticancer compounds, the retinoid-chalcone hybrids were tested against the colon cancer cell line HT-29. Retinoid like moiety was introduced through Friedel-Crafts alkylation of toluene. Among the synthesized compounds, the cyano derivative (E)-3-(3-oxo-3-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)prop-1-enyl)benzonitrile 8 showed submicromolar inhibitory activity with an IC(50) of 0.66 μM.     

Discovery of a novel series of potent S1P1 agonists

The discovery of a novel series of S1P1 agonists is described. Starting from a micromolar HTS positive, iterative optimization gave rise to several single-digit nanomolar S1P1 agonists. The compounds were able to induce internalization of the S1P1 receptor, and a selected compound was shown to be able to induce lymphopenia in mice after oral dosing.     

Phenology and roosting habits of the Central European grey long-eared bat Plecotus austriacus (Fischer 1829)

The authors monitored five maternity colonies of Plecotus austriacus to obtain data about phenology, roosting, and emergence behaviour. The bats occupied their roosts between April and October, with maximum colony sizes in August. Roosting sites in the attic’s roof ridge and temperatures of 20–25°C were favoured. Also considering the small colony (maximum 59) and cluster sizes (maximum 13 bats), P. austriacus behaved less thermophilic than other attic-dwelling species. During low temperatures, the bats chose small crevice-like roosting sites to compensate for that; during daytime, many bats remained hidden in crevices. Emergence began approximately 30 min after sunset; the bats used multiple, preferably crevice-like openings. P. austriacus left its summer roosts comparatively late; renovation works should, therefore, not start before November. For monitoring purposes, we recommend two to three emergence countings outside the attics in early August during warm weather, alongside two attic inspections 1–2 h before emergence for offspring monitoring.

     

Diversity of Glycosyl Hydrolases from Cellulose-Depleting Communities Enriched from Casts of Two Earthworm Species

The guts and casts of earthworms contain microbial assemblages that process large amounts of organic polymeric substrates from plant litter and soil; however, the enzymatic potential of these microbial communities remains largely unexplored. In the present work, we retrieved carbohydrate-modifying enzymes through the activity screening of metagenomic fosmid libraries from cellulose-depleting microbial communities established with the fresh casts of two earthworm species, Aporrectodea caliginosa and Lumbricus terrestris, as inocula. Eight glycosyl hydrolases (GHs) from the A. caliginosa-derived community were multidomain endo-β-glucanases, β-glucosidases, β-cellobiohydrolases, β-galactosidase, and β-xylosidases of known GH families. In contrast, two GHs derived from the L. terrestris microbiome had no similarity to any known GHs and represented two novel families of β-galactosidases/α-arabinopyranosidases. Members of these families were annotated in public databases as conserved hypothetical proteins, with one being structurally related to isomerases/dehydratases. This study provides insight into their biochemistry, domain structures, and active-site architecture. The two communities were similar in bacterial composition but significantly different with regard to their eukaryotic inhabitants. Further sequence analysis of fosmids and plasmids bearing the GH-encoding genes, along with oligonucleotide usage pattern analysis, suggested that those apparently originated from Gammaproteobacteria (pseudomonads and Cellvibrio-like organisms), Betaproteobacteria (Comamonadaceae), and Alphaproteobacteria (Rhizobiales).Microorganisms producing diverse glycosyl hydrolases (GHs) are widespread and typically thrive in environments where plant materials tend to accumulate and deteriorate (42, 73). The habitats of microorganisms with great GH diversity are the ruminant animal rumen, mouse bowel, and rabbit cecum (10, 24, 26, 28, 49, 74). Microorganisms associated with soil invertebrates in general and with soil earthworms in particular carry out metabolic processes that contribute to element cycling and are essential in sustaining processes which their hosts are unable to perform (20, 52, 72, 76). Although some species of earthworms produce cellulases (15, 55), they generally rely on microbes inhabiting their gastrointestinal (GI) tracts to perform cellulose utilization processes (31, 47, 77). Casts are of special interest in this respect. Considering that the overall numbers of cellulolytic microbes in earthworm casts are greater than those in soil (57), earthworm casts seem to play an important role in the decomposition of plant litter, serving as an inoculum for cellulosic substrates (9). It is important to note that microorganisms from preingested substratum (soil or plant litter) are predominant in the gut lumen (20); however, microbial populations in earthworm casts differ from those in soil in terms of diversity and the relative abundance of different taxa (29, 57, 63). It is anticipated that the enzymatic repertoire of such microbial communities must be especially broad toward diverse sugar-based polymeric, oligomeric, and monomeric substrates; however, among approximately 115 families of GHs with thousands of members known to date (12), none of the GHs have been derived from microorganisms of earthworm-associated microbial communities.The aim of the present work was therefore to examine the diversity of GHs in metagenome libraries derived from fresh casts of Aporrectodea caliginosa and Lumbricus terrestris earthworms via functional screening. Other important tasks of this work were to characterize individual enzymes and to gain insight into their structural-functional features. Finally, we performed sequence analysis of large contiguous DNA fragments of fosmids harboring the genes for GHs to associate them with the organism(s) that may produce them, which was complemented by conventional small-subunit (SSU) rRNA clone library sequencing analysis.     

Inter‐conversion of catalytic abilities in a bifunctional carboxyl/feruloyl‐esterase from earthworm gut metagenome

Carboxyl esterases (CE) exhibit various reaction specificities despite of their overall structural similarity. In present study we have exploited functional metagenomics, saturation mutagenesis and experimental protein evolution to explore residues that have a significant role in substrate discrimination. We used an enzyme, designated 3A6, derived from the earthworm gut metagenome that exhibits CE and feruloyl esterase (FAE) activities with p-nitrophenyl and cinnamate esters, respectively, with a [(k_cat/K_m)]_CE/[(k_cat/K_m)]_FAE factor of 17. Modelling-guided saturation mutagenesis at specific hotspots (Lys²⁸¹, Asp²⁸², Asn³¹⁶ and Lys³¹⁷) situated close to the catalytic core (Ser¹⁴³/Asp²⁷³/His³⁰⁵) and a deletion of a 34-AA–long peptide fragment yielded mutants with the highest CE activity, while cinnamate ester bond hydrolysis was effectively abolished. Although, single to triple mutants with both improved activities (up to 180-fold in k_cat/K_m values) and enzymes with inverted specificity ((k_cat/K_m)_CE/(k_cat/K_m)_FAE ratio of ∼0.4) were identified, no CE inactive variant was found. Screening of a large error-prone PCR-generated library yielded by far less mutants for substrate discrimination. We also found that no significant changes in CE activation energy occurs after any mutation (7.3 to −5.6 J mol⁻¹), whereas a direct correlation between loss/gain of FAE function and activation energies (from 33.05 to −13.7 J mol⁻¹) was found. Results suggest that the FAE activity in 3A6 may have evolved via introduction of a limited number of ‘hot spot’ mutations in a common CE ancestor, which may retain the original hydrolytic activity due to lower restrictive energy barriers but conveys a dynamic energetically favourable switch of a second hydrolytic reaction.     

Sorgoleone

Sorgoleone, a major component of the hydrophobic root exudate of sorghum [Sorghum bicolor (L.) Moench], is one of the most studied allelochemicals. The exudate also contains an equivalent amount of a lipid resorcinol analog as well as a number of minor sorgoleone congeners. Synthesis of sorgoleone is constitutive and compartmentalized within root hairs, which can accumulate up to 20 μg of exudate/mg root dry weight. The biosynthesis pathway involves unique fatty acid desaturases which produce an atypical 16:3 fatty acyl-CoA starter unit for an alkylresorcinol synthase that catalyzes the formation of a pentadecatrienylresorcinol intermediate. This intermediate is then methylated by SAM-dependent O-methyltransferases and dihydroxylated by cytochrome P450 monooxygenases. An EST data set derived from a S. bicolor root hair-specific cDNA library contained all the candidate sequences potentially encoding enzymes involved in the sorgoleone biosynthetic pathway. Sorgoleone interferes with several molecular target sites, including inhibition of photosynthesis in germinating seedlings. Sorgoleone is not translocated acropetally in older plants, but can be absorbed through the hypocotyl and cotyledonary tissues. Therefore, the mode of action of sorgoleone may be the result of inhibition of photosynthesis in young seedlings in concert with inhibition of its other molecular target sites in older plants. Due to its hydrophobic nature, sorgoleone is strongly sorbed in soil which increases its persistence, but experiments show that it is mineralized by microorganisms over time.