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  1. Takahashi N, Bocak L, Ghani IA
    Zootaxa, 2016 Jul 26;4144(1):145-50.
    PMID: 27470845 DOI: 10.11646/zootaxa.4144.1.11
    The net-winged beetle genus Alyculus Kasantsev is reported from Peninsular Malaysia for the first time and a new species, A. malaypeninsularis sp. nov., is described and illustrated. An expanded identification key to Alyculus males is provided and the biology and distribution of the species are discussed.
  2. Ichie T, Inoue Y, Takahashi N, Kamiya K, Kenzo T
    J Plant Res, 2016 Jul;129(4):625-635.
    PMID: 26879931 DOI: 10.1007/s10265-016-0795-2
    The vertical structure of a tropical rain forest is complex and multilayered, with strong variation of micro-environment with height up to the canopy. We investigated the relation between morphological traits of leaf surfaces and tree ecological characteristics in a Malaysian tropical rain forest. The shapes and densities of stomata and trichomes on the abaxial leaf surfaces and their relation with leaf characteristics such as leaf area and leaf mass per area (LMA) were studied in 136 tree species in 35 families with different growth forms in the tropical moist forest. Leaf physiological properties were also measured in 50 canopy and emergent species. Most tree species had flat type (40.4 %) or mound type (39.7 %) stomata. In addition, 84 species (61.76 %) in 22 families had trichomes, including those with glandular (17.65 %) and non-glandular trichomes (44.11 %). Most leaf characteristics significantly varied among the growth form types: species in canopy and emergent layers and canopy gap conditions had higher stomatal density, stomatal pore index (SPI), trichome density and LMA than species in understory and subcanopy layers, though the relation of phylogenetically independent contrasts to each characteristic was not statistically significant, except for leaf stomatal density, SPI and LMA. Intrinsic water use efficiency in canopy and emergent tree species with higher trichome densities was greater than in species with lower trichome densities. These results suggest that tree species in tropical rain forests adapt to a spatial difference in their growth forms, which are considerably affected by phylogenetic context, by having different stomatal and trichome shapes and/or densities.
  3. Ng WM, Chan CK, Takahashi N, Kawai N, Teh KK, Saravana R, et al.
    Singapore Med J, 2017 Feb;58(2):103-106.
    PMID: 26976222 DOI: 10.11622/smedj.2016061
    INTRODUCTION: Injuries to the medial structures of the elbow due to overhead throwing games are well documented. However, variations of medial epicondyles are not well described, especially in athletes with fused medial epicondyles. In this study, we evaluated variations in the medial epicondyle of baseball players who were aged 15-17 years and had fused epicondyles.

    METHODS: In this cross-sectional observational study, 155 skeletally mature baseball players with unilateral medial elbow pain and 310 elbow radiographs were reviewed by two independent reviewers. The medial epicondyles were categorised into three groups: normal, elongated or separated.

    RESULTS: Among the 155 patients, 65 (41.9%) had normal epicondyles, 41 (26.5%) had elongated epicondyles and 49 (31.6%) had separated epicondyles. The medial epicondyle was larger on the dominant arm for 125 (80.6%) patients; the mean surface area on the dominant arm was 222.50 ± 45.77 mm2, while that of the non-dominant arm was 189.14 ± 39.56 mm2(p < 0.01). Among the three categories of medial epicondyles, separated epicondyles had the largest surface area, followed by elongated and normal epicondyles.

    CONCLUSION: Medial epicondyles in adolescent throwing athletes can be categorised into three different groups according to their shape (normal, elongated and separated). We observed a correlation between the shape and the surface area of the medial epicondyle in adolescent throwing athletes, with separated medial epicondyles having the largest surface area. Further studies and follow-up are needed to determine the prognostic value and clinical significance of these morphological variations.

    Study done in Japan
  4. Koike H, Harada M, Kusamoto A, Xu Z, Tanaka T, Sakaguchi N, et al.
    Front Endocrinol (Lausanne), 2023;14:1124405.
    PMID: 36875481 DOI: 10.3389/fendo.2023.1124405
    Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-age women, affecting up to 15% of women in this group, and the most common cause of anovulatory infertility. Although its etiology remains unclear, recent research has revealed the critical role of endoplasmic reticulum (ER) stress in the pathophysiology of PCOS. ER stress is defined as a condition in which unfolded or misfolded proteins accumulate in the ER because of an imbalance in the demand for protein folding and the protein-folding capacity of the ER. ER stress results in the activation of several signal transduction cascades, collectively termed the unfolded protein response (UPR), which regulates various cellular activities. In principle, the UPR restores homeostasis and keeps the cell alive. However, if the ER stress cannot be resolved, it induces programmed cell death. ER stress has recently been recognized to play diverse roles in both physiological and pathological conditions of the ovary. In this review, we summarize current knowledge of the roles of ER stress in the pathogenesis of PCOS. ER stress pathways are activated in the ovaries of both a mouse model of PCOS and in humans, and local hyperandrogenism in the follicular microenvironment associated with PCOS is responsible for activating these. The activation of ER stress contributes to the pathophysiology of PCOS through multiple effects in granulosa cells. Finally, we discuss the potential for ER stress to serve as a novel therapeutic target for PCOS.
  5. Kusamoto A, Harada M, Azhary JMK, Kunitomi C, Nose E, Koike H, et al.
    FASEB J, 2021 11;35(11):e21971.
    PMID: 34653284 DOI: 10.1096/fj.202101051R
    It has been recently recognized that prenatal androgen exposure is involved in the development of polycystic ovary syndrome (PCOS) in adulthood. In addition, the gut microbiome in adult patients and rodents with PCOS differs from that of healthy individuals. Moreover, recent studies have suggested that the gut microbiome may play a causative role in the pathogenesis of PCOS. We wondered whether prenatal androgen exposure induces gut microbial dysbiosis early in life and is associated with the development of PCOS in later life. To test this hypothesis, we studied the development of PCOS-like phenotypes in prenatally androgenized (PNA) female mice and compared the gut microbiome of PNA and control offspring from 4 to 16 weeks of age. PNA offspring showed a reproductive phenotype from 6 weeks and a metabolic phenotype from 12 weeks of age. The α-diversity of the gut microbiome of the PNA group was higher at 8 weeks and lower at 12 and 16 weeks of age, and the β-diversity differed from control at 8 weeks. However, a significant difference in the composition of gut microbiome between the PNA and control groups was already apparent at 4 weeks. Allobaculum and Roseburia were less abundant in PNA offspring, and may therefore be targets for future interventional studies. In conclusion, abnormalities in the gut microbiome appear as early as or even before PCOS-like phenotypes develop in PNA mice. Thus, the gut microbiome in early life is a potential target for the prevention of PCOS in later life.
  6. Kusamoto A, Harada M, Minemura A, Matsumoto A, Oka K, Takahashi M, et al.
    Front Cell Dev Biol, 2024;12:1365624.
    PMID: 38590777 DOI: 10.3389/fcell.2024.1365624
    The gut microbiome is implicated in the pathogenesis of polycystic ovary syndrome (PCOS), and prenatal androgen exposure is involved in the development of PCOS in later life. Our previous study of a mouse model of PCOS induced by prenatal dihydrotestosterone (DHT) exposure showed that the reproductive phenotype of PCOS appears from puberty, followed by the appearance of the metabolic phenotype after young adulthood, while changes in the gut microbiota was already apparent before puberty. To determine whether the prenatal or postnatal nurturing environment primarily contributes to these changes that characterize prenatally androgenized (PNA) offspring, we used a cross-fostering model to evaluate the effects of changes in the postnatal early-life environment of PNA offspring on the development of PCOS-like phenotypes and alterations in the gut microbiota in later life. Female PNA offspring fostered by normal dams (exposed to an abnormal prenatal environment only, fostered PNA) exhibited less marked PCOS-like phenotypes than PNA offspring, especially with respect to the metabolic phenotype. The gut microbiota of the fostered PNA offspring was similar to that of controls before adolescence, but differences between the fostered PNA and control groups became apparent after young adulthood. In conclusion, both prenatal androgen exposure and the postnatal early-life environment created by the DHT injection of mothers contribute to the development of PCOS-like phenotypes and the alterations in the gut microbiota that characterize PNA offspring. Thus, both the pre- and postnatal environments represent targets for the prevention of PCOS and the associated alteration in the gut microbiota in later life.
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