Effects of Citric Acid and l-Carnitine on Physical Fatigue

We examined the effects of citric acid and l-carnitine administration on physical fatigue. In a double-blind, placebo-controlled, 3-way crossover study, 18 healthy volunteers were randomized to oral citric acid (2,700 mg/day), l-carnitine (1,000 mg/day), or placebo for 8 days. The fatigue-inducing physical task consisted of workload trials on a cycle ergometer at fixed workloads for 2 h on 2 occasions. Before the physical load, salivary chromogranin A, measured as a physiological stress marker, was lower in the group given citric acid than in the group given placebo. Also, after the physical load, the subjective feeling of fatigue assessed with a visual analogue scale was lower in the citric acid group than in the placebo group. In contrast, l-carnitine had no effect on chromogranin A or subjective fatigue. These results suggest that citric acid reduces physiological stress and attenuates physical fatigue, whereas l-carnitine does not

Essential Insight of Direct Electron Transfer-Type Bioelectrocatalysis by Membrane-Bound d-Fructose Dehydrogenase with Structural Bioelectrochemistry

電極を基質認識できる酵素の反応メカニズムを解明 --次世代バイオセンシングにつながる基盤技術--. 京都大学プレスリリース. 2023-10-16.Flavin adenine dinucleotide-dependent d-fructose dehydrogenase (FDH) from Gluconobacter japonicus NBRC3260, a membrane-bound heterotrimeric flavohemoprotein capable of direct electron transfer (DET)-type bioelectrocatalysis, was investigated from the perspective of structural biology, bioelectrochemistry, and protein engineering. DET-type reactions offer several benefits in biomimetics (e.g., biofuel cells, bioreactors, and biosensors) owing to their mediator-less configuration. FDH provides an intense DET-type catalytic signal; therefore, extensive research has been conducted on the fundamental principles and applications of biosensors. Structural analysis using cryo-electron microscopy and single-particle analysis has revealed the entire FDH structures with resolutions of 2.5 and 2.7 Å for the reduced and oxidized forms, respectively. The electron transfer (ET) pathway during the catalytic oxidation of d-fructose was investigated by using both thermodynamic and kinetic approaches. Structural analysis has shown the localization of the electrostatic surface charges around heme 2c in subunit II, and experiments using functionalized electrodes with a controlled surface charge support the notion that heme 2c is the electrode-active site. Furthermore, two aromatic amino acid residues (Trp427 and Phe489) were located in a possible long-range ET pathway between heme 2c and the electrode. Two variants (W427A and F489A) were obtained by site-directed mutagenesis, and their effects on DET-type activity were elucidated. The results have shown that Trp427 plays an essential role in accelerating long-range ET and triples the standard rate constant of heterogeneous ET according to bioelectrochemical analysis

Survey of whole air data from the second airborne Biomass Burning and Lightning Experiment using principal component analysis

Hydrocarbon and halocarbon measurements collected during the second airborne Biomass Burning and Lightning Experiment (BIBLE-B) were subjected to a principal component analysis (PCA), to test the capability for identifying intercorrelated compounds within a large whole air data set. The BIBLE expeditions have sought to quantify and understand the products of burning, electrical discharge, and general atmospheric chemical processes during flights arrayed along the western edge of the Pacific. Principal component analysis was found to offer a compact method for identifying the major modes of composition encountered in the regional whole air data set. Transecting the continental monsoon, urban and industrial tracers (e.g., combustion byproducts, chlorinated methanes and ethanes, xylenes, and longer chain alkanes) dominated the observed variability. Pentane enhancements reflected vehicular emissions. In general, ethyl and propyl nitrate groupings indicated oxidation under nitrogen oxide (NOx) rich conditions and hence city or lightning influences. Over the tropical ocean, methyl nitrate grouped with brominated compounds and sometimes with dimethyl sulfide and methyl iodide. Biomass burning signatures were observed during flights over the Australian continent. Strong indications of wetland anaerobics (methane) or liquefied petroleum gas leakage (propane) were conspicuous by their absence. When all flights were considered together, sources attributable to human activity emerged as the most important. We suggest that factor reductions in general and PCA in particular may soon play a vital role in the analysis of regional whole air data sets, as a complement to more familiar methods

In Situ Hybridization Analysis of the Expression of Futsch, Tau, and MESK2 Homologues in the Brain of the European Honeybee (Apis mellifera L.)

BACKGROUND: The importance of visual sense in Hymenopteran social behavior is suggested by the existence of a Hymenopteran insect-specific neural circuit related to visual processing and the fact that worker honeybee brain changes morphologically according to its foraging experience. To analyze molecular and neural bases that underlie the visual abilities of the honeybees, we used a cDNA microarray to search for gene(s) expressed in a neural cell-type preferential manner in a visual center of the honeybee brain, the optic lobes (OLs). METHODOLOGY/PRINCIPAL FINDINGS: Expression analysis of candidate genes using in situ hybridization revealed two genes expressed in a neural cell-type preferential manner in the OLs. One is a homologue of Drosophila futsch, which encodes a microtubule-associated protein and is preferentially expressed in the monopolar cells in the lamina of the OLs. The gene for another microtubule-associated protein, tau, which functionally overlaps with futsch, was also preferentially expressed in the monopolar cells, strongly suggesting the functional importance of these two microtubule-associated proteins in monopolar cells. The other gene encoded a homologue of Misexpression Suppressor of Dominant-negative Kinase Suppressor of Ras 2 (MESK2), which might activate Ras/MAPK-signaling in Drosophila. MESK2 was expressed preferentially in a subclass of neurons located in the ventral region between the lamina and medulla neuropil in the OLs, suggesting that this subclass is a novel OL neuron type characterized by MESK2-expression. These three genes exhibited similar expression patterns in the worker, drone, and queen brains, suggesting that they function similarly irrespective of the honeybee sex or caste. CONCLUSIONS: Here we identified genes that are expressed in a monopolar cell (Amfutsch and Amtau) or ventral medulla-preferential manner (AmMESK2) in insect OLs. These genes may aid in visualizing neurites of monopolar cells and ventral medulla cells, as well as in analyzing the function of these neurons

食生活の多様性とうつ病および自殺の有病率との関連 ―26年間の国際比較研究―

Purpose: This study aimed to determine the associations of dietary diversity with depression and suicide rates by an ecological analysis using 26-years worldwide statistics.Methods: Average food supply and energy supply by country, excluding loss between production and household, were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database (FAOSTAT). Dietary diversity scores were calculated from food group classifications. Age-standardized depression prevalence and suicide rates per 100,000 people by country were obtained from the Global Burden of Disease (GBD) 2017 database. The association between food diversity scores and depression prevalence and suicide rates was analyzed by a mixed effects model controlling for covariates in 137 countries with populations of 1 million or greater.Results: A significant negative association was found in the analysis of the relationship between dietary diversity and the prevalence of major depression in the model controlled for all covariates [β (se) = –225.6 (61.9), p < 0.001]. In addition, a significant negative association between dietary diversity and the suicide rate was also found in the model controlled for all covariates [β (se) = –3.08 (1.50), p < 0.05].Conclusion: Dietary diversity was significantly negatively associated with the rates of major depression and suicide. Diets rich in foods may reduce the prevalence of depression and suicide rate.【目的】本研究は、26年間の世界的な統計を用いた生態学的分析により、食生活の多様性とうつ病や自殺率との関連を明らかにすることを目的とした。【方法】生産と家庭間の喪失を除く国別平均食料供給量とエネルギー供給量を国連食糧農業機関統計局データベース（FAOSTAT）から入手した。食物群分類から食事多様性スコアを算出した。年齢標準化された国別の人口10万人当たりのうつ病有病率と自殺率は、Global Burden of Disease（GBD）2017データベースから取得した。人口100万人以上の137カ国を対象に、食品多様性スコアとうつ病有病率および自殺率との関連を、共変量を制御した混合効果モデルで解析した。【結果】食生活の多様性とうつ病の有病率との関係を分析したところ、すべての共変量を調整したモデルにおいて、有意な負の関連が認められた［β（se）＝－225.6（61.9）、p < 0.001］。さらに、食生活の多様性と自殺率との間の有意な負の関連も、すべての共変量を調整したモデルで認められた［β（se）= －3.08（1.50）、p < 0.05］。【結論】食生活の多様性は、うつ病および自殺の発生率と有意に負の関連があった。食物を豊富に含む食事は、うつ病や自殺を減少させる可能性がある

Latitudinal cline in the foraging dichotomy of loggerhead sea turtles reveals the importance of East China Sea for priority conservation

Special Issue: Biological traits, geographic distributions and species conservation in aquatic ecosystems[Aim]Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. [Location]North Pacific Ocean. [Methods]We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). [Results]Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. [Main conclusions]The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection

マウスリンパ組織におけるレプチンレセプターの発現

The mammalian thymus involutes with age. Both the decrease of lymphocyte-accumulated region and the replacement by fat tissue begin at puberty and continue throughout life. In the mouse thymus, though no typical fat cells are found at birth, fat cells appeared at the latest 3 weeks old preceding to the atrophy of cortical and medullary regions. Physiological functions of fat cells proliferated and differentiated in the thymus after birth are unknown. As fat cells appeared in the 3-week-old mouse thymus have shown to express leptin mRNA, we examined whether leptin receptor type b (OBRL) is expressed or not in the thymus and, in comparison, in the secondary lymphoid tissues, spleen, mesenteric lymph node and Peyer' s patch. OBRL mRNA was detected in both thymus and all secondary lymphoid tissues examined by RTPCR method. Furthermore, OBRL mRNA was also detected in the isolated cells with mouse-lymphocyte separation medium from both thymus and spleen free cells washed out in saline from dissected tissues. It is suggested that fat cells differenciated as early as 3 weeks old in the thymus produce leptin and affect other thymus cells, lymphocytes probably, through OBRL. It remains to be clarified whether the leptin-OBRL interaction influences age involution in the thymus

An Autopsy Case of Anaplastic Pancreatic Ductal Carcinoma (Spindle Cell Type) Multiple Onset in the Pancreas

This is a case of a 75-year-old man who was diagnosed with anaplastic pancreatic ductal carcinoma (spindle cell type). His image findings showed pancreatic head cysts and pancreatic head, body, and tail tumors respectively. EUS-FNA was performed to the pancreatic head and pancreatic body tumors, and the same high atypical type cells suspected of cancer were obtained from either specimen, and finally total pancreatectomy was performed. On the specimen, there were 4 lesions in the pancreas; histology showed that the same anaplastic pancreatic ductal carcinoma (spindle cell type) was obtained from the pancreatic head cyst and the pancreatic tumors