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Background: Heat acclimatization studies have reported that tropical natives have better physiological function to tolerate heat exposure compared to those from temperate natives, in which may result in a better ability to show a better resistance to performance losses during heat stress. In this study, we investigate whether the degree of heat acclimatization affects cognitive abilities during heat exposure by comparing heat acclimatization level of subjects from Southeast Asia and temperate natives from Japan. Methods: Eleven tropical males from Southeast Asia and ten temperate males from Japan participated in this study and performed two types of cognitive task: short-term memory test and mental arithmetic test, under control and passive heat exposure conditions. Passive heat condition was stimulated through leg immersion protocol by immersing subjects’ lower legs into a hot water maintained at 42 °C in a chamber controlled at 28 °C air temperature and 50% relative humidity. Results: The results show that the subjects in tropical group, who had smaller increase of rectal temperature, did not show any performance losses in both cognitive tests during heat exposure, while for Japanese group, there was performance decrement in mental arithmetic test during heat exposure (P < 0.05). We also found that the subjects in both tropical and Japanese groups tried to maintain their performance by increasing oxyhemoglobin in their prefrontal cortex area during performing the tasks during heat exposure. In addition, the subjects in the Japanese group showed higher increase of oxyhemoglobin when they performed the tasks during heat exposure than those when they performed the tasks in control condition (P < 0.05), while the subjects in tropical group did not show any differences in oxyhemoglobin during task performance between control and heating conditions. Conclusions: In addition to a better ability to maintain their homeostasis during heat exposure, tropical natives from Southeast Asia showed better resistance to performance loss during heat exposure in comparison with temperate natives from Japan. The tropical natives also showed smaller increase of oxyhemoglobin indicating less cognitive effort to maintain performance. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate smart features required for the next generation of personal protective equipment (PPE) for firefighters in Australia, Korea, Japan, and the USA. Questionnaire responses were obtained from 167 Australian, 351 Japanese, 413 Korean, and 763 U.S. firefighters (1,611 males and 61 females). Preferences concerning smart features varied among countries, with 27% of Korean and 30% of U.S. firefighters identifying 'a location monitoring system' as the most important element. On the other hand, 43% of Japanese firefighters preferred 'an automatic body cooling system' while 21% of the Australian firefighters selected equally 'an automatic body cooling system' and 'a wireless communication system'. When asked to rank these elements in descending priority, responses across these countries were very similar with the following items ranked highest: 'a location monitoring system', 'an automatic body cooling system', 'a wireless communication system', and 'a vision support system'. The least preferred elements were 'an automatic body warming system' and 'a voice recording system'. No preferential relationship was apparent for age, work experience, gender or anthropometric characteristics. These results have implications for the development of the next generation of PPE along with the international standardisation of the smart PPE. [ABSTRACT FROM AUTHOR]

Mycobacterium vaccae is a species of nonpathogenic bacterium that lives naturally in soil. This study compared the physiological effects at a metabolomic level with autonomic nervous system responses in adults during soil-mixing activities, based on the presence or absence of M. vaccae in the soil. Twenty-nine adult participants performed soil-mixing activities for 5 minutes using sterilized soil with culture media and M. vaccae, respectively. Blood samples were drawn twice from each participant after each activity. Electroencephalograms and electrocardiograms were measured during the activity. Serum metabolites underwent metabolite profiling by gas chromatography, followed by multivariate analyses. Soil-emitted volatile organic compounds were identified using the solid-phase microextraction and gas chromatography-mass spectroscopy, followed by multivariate analyses. The volatile compound analysis revealed that the metabolites related to esters and sulfur-containing compounds are greater in soil with M. vaccae. Serum metabolomics revealed that the treatment group (soil inoculated by M. vaccae) possesses relatively higher levels of inter-alia organic and amino acids compared with the control group (soil mixed with culture media). In the treatment group, the electroencephalogram and electrocardiogram revealed that alpha band activity of the occipital lobe increases, while heart rate decreases. This study concludes that M. vaccae soil contact can affect human metabolic and autonomic reactions.

Cellular metabolic changes reflect the characteristics of patients with acute myeloid leukemia (AML) caused by genetic variations, which are important in establishing AML treatment. However, little is known about the metabolic profile of patients with genetic variation-induced AML. Furthermore, the metabolites differ with disease progression. Here, metabolites in the bone marrow serum of ten patients with AML and healthy individuals were analyzed using gas chromatography–mass spectrometry. Compared with that in healthy individuals, expression of most metabolites decreased in patients with AML; hydroxylamine, 2-hydroxybutyric acid, monomethylphosphate, and ethylphosphate expression was unusually increased in the patients. We further examined serial metabolite changes across the initial diagnosis, postremission, and relapse phases. Patients with relapse showed increased metabolite expression compared with those in the diagnostic phase, confirming that patients with AML had aggressively modified leukemic cells. However, a clear difference in metabolite distribution was not observed between the diagnosis and complete remission phases, suggesting that the metabolic microenvironment did not change significantly despite complete remission. Interestingly, metabolite profiles differed with genetic variations in leukemic cells. Our results, which were obtained using paired samples collected during AML progression, provide valuable insights for identifying vulnerable targets in the AML metabolome and developing new treatment strategies.

Although many studies have been conducted on leukemia, only a few have analyzed the metabolomic profiles of various leukemic cells. In this study, the metabolomes of THP-1, U937, KG-1 (acute myelogenous leukemia, AML), K562 (chronic myelogenous leukemia, CML), and cord blood-derived CD34-positive hematopoietic stem cells (HSC) were analyzed using gas chromatography-mass spectrometry, and specific metabolic alterations were found using multivariate statistical analysis. Compared to HSCs, leukemia cell metabolomes were found to have significant alterations, among which three were related to amino acids, three to sugars, and five to fatty acids. Compared to CML, four metabolomes were observed specifically in AML. Given that overall more metabolites are present in leukemia cells than in HSCs, we observed that the activation of glycolysis and oxidative phosphorylation (OXPHOS) metabolism facilitated the incidence of leukemia and the proliferation of leukemic cells. Analysis of metabolome profiles specifically present in HSCs and leukemia cells greatly increases our basic understanding of cellular metabolic characteristics, which is valuable fundamental knowledge for developing novel anticancer drugs targeting leukemia metabolism.

Caffeine intake is strongly linked to lipid metabolism. We previously reported the age-dependent physiological effects of caffeine intake in a Caenorhabditis elegans model. Since nutritional status can actively influence metabolism and overall health, in this study, we evaluated the effect of caffeine intake on lipid metabolism in adult-stage C. elegans. We found that, in C. elegans, fat storage and the level of phosphoethanolamine (PE) were significantly reduced with caffeine intake. In addition, mitochondrial activity decreased and mitochondrial morphology was disrupted, and the expression of oxidative stress response genes, hsp-6, gst-4, and daf-16, was induced by caffeine intake. Furthermore, the level of an energy metabolism sensor, phospho-AMP-activated protein kinase, was increased, whereas the expression of the sterol regulatory element binding protein gene and its target stearoyl-CoA desaturase genes, fat-5, -6, and -7, was decreased with caffeine intake. These findings suggest that caffeine intake causes mitochondrial dysfunction and reduces lipogenesis. Interestingly, these changes induced by caffeine intake were partially alleviated by PE supplementation, suggesting that the reduction in mitochondrial activity and lipogenesis is in part because of the low PE level, and proper dietary supplementation can improve organelle integrity.

The trophic interactions of entomopathogenic fungi in different ecological niches viz., soil, plants, or insect themselves are effectively regulated by their maneuvered metabolomes and the plethora of metabotypes. In this article, we discuss a holistic framework of co-evolutionary metabolomes and metabotypes to model the interactions of biocontrol fungi especially with mycosed insects. Conventionally, the studies involving fungal biocontrol mechanisms are reported in the context of much aggrandized fungal entomotoxins while the adaptive response mechanisms of host insects are relatively overlooked. The present review asserts that the selective pressure exerted among the competing or interacting species drives alterations in their overall metabolomes which ultimately implicates in corresponding metabotypes. Quintessentially, metabolomics offers a most generic and tractable model to assess the fungal-insect antagonism in terms of interaction biomarkers, biosynthetic pathway plasticity, and their co-evolutionary defense. The fungi chiefly rely on a battery of entomotoxins viz., secondary metabolites falling in the categories of NRP's (non-ribosomal peptides), PK's (polyketides), lysine derive alkaloids, and terpenoids. On the contrary, insects overcome mycosis through employing different layers of immunity manifested as altered metabotypes (phenoloxidase activity) and overall metabolomes viz., carbohydrates, lipids, fatty acids, amino acids, and eicosanoids. Here, we discuss the recent findings within conventional premise of fungal entomotoxicity and the evolution of truculent immune response among host insect. The metabolomic frameworks for fungal-insect interaction can potentially transmogrify our current comprehensions of biocontrol mechanisms to develop the hypervirulent biocontrol strains with least environmental concerns. Moreover, the interaction metabolomics (interactome) in complementation with other -omics cascades could further be applied to address the fundamental bottlenecks of adaptive co-evolution among biological species.

Liquid chromatography-mass spectrometry (LC-MS)-based untargeted metabolomics implies that annotated metabolites can serve as potential markers of the associated bioactivities of plant extracts. Firstly, we selected Aphananthe aspera and Zelkova serrata (Family: Ulmaceae) from 16 Korean plant species based on their distinct principal component analysis (PCA) patterns in LC-MS datasets and antioxidant activity assays. Further, we chose 40% solid-phase extraction (SPE) extracts of the two species displaying the highest antioxidant activities coupled with distinct PCA patterns. Examining the metabolite compositions of the 40% SPE extracts, we observed relatively higher abundances of quercetin, kaempferol, and isorhamnetin O-glucosides for A. aspera, whereas quercetin, isorhamnetin O-glucuronides, and procyanidin dimer were relatively higher in Z. serrata. These metabolites were clearly distinguished in pathway map and displayed strong positive correlations with antioxidant activity. Further, we performed preparative high-performance liquid chromatography (prep-HPLC) analysis coupled with the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assay to validate their functional correlations. As a result, quercetin O-sophoroside was determined as the main antioxidant in A. aspera, while isorhamnetin O-glucuronide and procyanidin dimer were the primary antioxidants in Z. serrata. The current study suggests that the LC-MS-based untargeted metabolomics strategy can be used to illuminate subtle metabolic disparities as well as compounds associated with bioactivities.