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1.
Front Psychol ; 15: 1276585, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38725954

RESUMO

Workplace diversity has recently gained increasing significance and urgency in business organizations. This promotion may stem from information processing, and specifically from information elaboration. Information elaboration leverages diverse task-related information and skills possessed by members, fostering the exchange of diverse perspectives, elaborate discussions, and achieving high team performance. In this context, cognitive diversity, encompassing members' knowledge, skills, and perspectives, may have a positive impact. However, some previous studies suggest that cognitive diversity can lead to affective conflict and impede information processing. In organizations with highly homogeneous social and cultural backgrounds, cognitive diversity may not be effectively utilized in the information elaboration process, potentially yielding negative effects. Authentic leadership is recognized as a significant contributor to facilitating team processes including information processing, with various studies demonstrating its effectiveness. This study hypothesized that cognitive diversity negatively affects the information elaboration process, while authentic leadership has a positive effect. To test these hypotheses, we employed multilevel structural equation modeling analysis based on data collected from 375 respondents in 90 teams across various industries in Japan. The results showed that cognitive diversity negatively affects information elaboration at the individual level. By contrast, authentic leadership positively affects information elaboration at both individual and team levels. These findings suggest that the effect of cognitive diversity on information processing in the workplace may not always be positive, particularly in a sociocultural context that values homogeneity, as observed in Japanese organizations. This study advances the literature on authentic leadership by validating its effect on information elaboration and provides practical implications for diversity management. Additionally, it underscores the effectiveness of authentic leadership in leveraging team members' cognitive diversity to facilitate information elaboration.

2.
Int J Dev Disabil ; 70(2): 296-305, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38481451

RESUMO

Introduction: Children with autism spectrum disorder (ASD) face numerous challenges in transitioning to elementary school, which can cause confusion for the children and concern among their parents. Aims: This study aimed to identify the process of school transition from kindergarten to elementary school for children with autism spectrum disorder in Japan, by evaluating the effectiveness of a school transition program. Methods: A focus group interview was conducted with seven parents who participated in a transition program. They were asked about communication with the teachers, support obtained from the school, and their experiences after their children entered elementary school. After the group interview was recorded and transcribed, the data were analyzed using inductive content analysis to determine the parents' experiences of the school transition process. Findings: Six main themes emerged from the focus group interview: acquisition of prerequisite skills, adjustment in dealing with children with ASD, communication between school and home, communication between peers and children with autism spectrum disorder, collaboration with special needs education teachers, and the principal's understanding of special needs education. Conclusion: These findings provide an overview of the challenges and possible solutions to support school transitions for children with autism spectrum disorder in inclusive educational environments.

3.
Sci Rep ; 13(1): 18549, 2023 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-37899460

RESUMO

4-hydroxytamoxifen (OHT) is an anti-cancer drug that induces apoptosis in breast cancer cells. Although changes in lipid levels and mitochondrial respiration have been observed in OHT-treated cells, the overall mechanisms underlying these metabolic alterations are poorly understood. In this study, time-series metabolomics and lipidomics were used to analyze the changes in metabolic profiles induced by OHT treatment in the MCF-7 human breast cancer cell line. Lipidomic and metabolomic analyses revealed increases in ceramide, diacylglycerol and triacylglycerol, and decreases in citrate, respectively. Gene expression analyses revealed increased expression of ATP-dependent citrate lyase (ACLY) and subsequent fatty acid biosynthetic enzymes, suggesting that OHT-treated MCF-7 cells activate citrate-to-lipid metabolism. The significance of the observed metabolic changes was evaluated by co-treating MCF-7 cells with OHT and ACLY or a diacylglycerol O-acyltransferase 1 (DGAT1) inhibitor. Co-treatment ameliorated cell death and reduced mitochondrial membrane potential compared to that in OHT treatment alone. The inhibition of cell death by co-treatment with an ACLY inhibitor has been observed in other breast cancer cell lines. These results suggest that citrate-to-lipid metabolism is critical for OHT-induced cell death in breast cancer cell lines.


Assuntos
Neoplasias da Mama , Lipidômica , Humanos , Feminino , Células MCF-7 , Tamoxifeno/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Apoptose , Metaboloma , Citratos
4.
PLoS One ; 18(3): e0281195, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36996253

RESUMO

Small regulatory RNAs (sRNAs) are involved in antiviral defense and gene regulation. Although roles of RNA-dependent RNA Polymerases (RdRPs) in sRNA biology are extensively studied in nematodes, plants and fungi, understanding of RdRP homologs in other animals is still lacking. Here, we study sRNAs in the ISE6 cell line, which is derived from the black-legged tick, an important vector of human and animal pathogens. We find abundant classes of ~22nt sRNAs that require specific combinations of RdRPs and sRNA effector proteins (Argonautes or AGOs). RdRP1-dependent sRNAs possess 5'-monophosphates and are mainly derived from RNA polymerase III-transcribed genes and repetitive elements. Knockdown of some RdRP homologs misregulates genes including RNAi-related genes and the regulator of immune response Dsor1. Sensor assays demonstrate that Dsor1 is downregulated by RdRP1 through the 3'UTR that contains a target site of RdRP1-dependent repeat-derived sRNAs. Consistent with viral gene repression by the RNAi mechanism using virus-derived small interfering RNAs, viral transcripts are upregulated by AGO knockdown. On the other hand, RdRP1 knockdown unexpectedly results in downregulation of viral transcripts. This effect is dependent on Dsor1, suggesting that antiviral immunity is enhanced by RdRP1 knockdown through Dsor1 upregulation. We propose that tick sRNA pathways control multiple aspects of immune response via RNAi and regulation of signaling pathways.


Assuntos
Ixodes , Pequeno RNA não Traduzido , Animais , Humanos , Ixodes/genética , Ixodes/metabolismo , Eucariotos/genética , Sistema de Sinalização das MAP Quinases , Antivirais , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Interferência de RNA , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Pequeno RNA não Traduzido/genética , Pequeno RNA não Traduzido/metabolismo
5.
Adv Health Sci Educ Theory Pract ; 28(1): 87-106, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35951128

RESUMO

The ability of doctors to empathise with patients is a crucial concern in establishing humanistic medicine. Therefore, the cultivation of this ability has been discussed extensively in medical education. One theory suggests that the experience of patienthood can increase empathy among doctors. This theory is supported by previous research that published doctors' illness narratives. However, the concept of empathy has been ambiguously defined in academic fields, including medicine; therefore, analysing how doctors experience 'empathy' in their interactions with patients is difficult. Our research question is how doctors who became patients describe the relationship between their illness experiences and the interactions with patients after their illness. To this end, this paper initially tracks the debates on 'empathy' in medicine and other disciplines, to develop a lens for analysing doctors' illness narratives. Next, we conduct a narrative analysis of illness stories from 18 Japanese medical doctors who became patients. Our analysis supports the traditional idea that an illness can enable a doctor to become more empathetic. However, this is overly simplistic; how doctors experience and subsequently process their illness is more complex. Moreover, this notion can disregard doctors' suffering in these circumstances, and fail to represent the often-lengthy process of mastering 'empathy' based on their experiences. Therefore, our analysis deconstructed the concept of 'empathy', showing that it can appear in various ways. Further research is required to elucidate how empathy is cultivated during the process of transformation of doctors' illnesses, focusing on their communities and practices.


Assuntos
Relações Médico-Paciente , Médicos , Humanos , População do Leste Asiático , Empatia , Narração
6.
J Biosci Bioeng ; 135(2): 102-108, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36494248

RESUMO

Although various yeast strains used in the food industry have been characterized by multilayer analysis, knowledge of the variation of lipid profiles involved in fermentation characteristics and stress tolerance remains in its infancy. In this study, untargeted lipidomics was applied to 10 yeast strains, including laboratory, baker's, wine, and sake yeasts, which exhibit distinct fermentation phenotypes, to obtain a comprehensive overview of the yeast lipidome. The relative standard deviation (RSD) in the abundance of the 352 identified lipid molecular species was investigated to reveal the specific and common lipids. Lipids containing very long-chain fatty acids and hydroxy long-chain fatty acids showed relatively large RSD, whereas lipids containing acyl chains, which are commonly found in yeast, such as C16-C18, showed less RSD among the 10 strains. Furthermore, principal component analysis of lipid profiles showed similar trends among industrial yeast strains. As lipids are involved in yeast phenotypes, including stress tolerance and fermentation characteristics, correlation analysis was performed with lipid abundance and phenotypes. The results revealed that molecular species with a high RSD in abundance among the 10 strains were correlated with specific stress tolerance and fermentation phenotypes.


Assuntos
Proteínas de Saccharomyces cerevisiae , Vinho , Saccharomyces cerevisiae/metabolismo , Lipidômica , Proteínas de Saccharomyces cerevisiae/genética , Vinho/análise , Ácidos Graxos , Fermentação
7.
Metabolites ; 12(7)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35888770

RESUMO

Isotope tracing is a powerful technique for elucidating intracellular metabolism. Experiments utilizing this technique involve various processes, such as the correction of natural isotopes. Although some previously developed software are available for these procedures, there are still time-consuming steps in isotope tracing including the creation of an isotope measurement method in mass spectrometry (MS) and the interpretation of obtained labeling data. Additionally, these multi-step tasks often require data format conversion, which is also time-consuming. In this study, the Isotope Calculation Gadgets, a series of software that supports an entire workflow of isotope-tracing experiments, was developed in the Garuda platform, an open community. Garuda is a graphical user interface-based platform that allows individual operations to be sequentially performed, without data format conversion, which significantly reduces the required time and effort. The developed software includes new features that construct channels for isotopomer measurements, as well as conventional functions such as natural isotope correction, the calculation of fractional labeling and split ratio, and data mapping, thus facilitating an overall workflow of isotope-tracing experiments through smooth functional integration.

8.
BMC Med Educ ; 22(1): 196, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35317790

RESUMO

BACKGROUND: In faculty development, understanding each participant's cultural context is important. However, there is scarce evidence on how to improve cultural understanding in faculty development. Cultural anthropology is a discipline that focuses on developing cultural self-awareness by understanding different cultures. Professionals from this field can be crucial to the goal of cultivating cultural awareness among medical educators. The aims of this study are to 1) develop and modify cultural anthropology sessions in faculty development and 2) evaluate the effectiveness of these sessions, including their long-term impacts. METHODS: The cultural anthropology sessions were organized as part of a longitudinal faculty development program-Foundation Course for Medical Education-at Kyoto University in Japan. The study included 47 medical educators participating in faculty development and three lecturers: two cultural anthropologists and a medical educator. We developed the cultural anthropology sessions and implemented them in the longitudinal faculty development program. In these sessions, cultural anthropologists used inquiry-guided reflection. An action research methodology was employed and repeated in four cycles from 2015 to 2018. Qualitative and quantitative data were collected during the action research cycles. The qualitative data were thematically analyzed. RESULTS: The cultural anthropologists' inquiries fostered learning during the sessions, and three themes-cultural relativism, attention to context, and reframing-were synthesized. As a long-term impact of the sessions, the learners reported becoming more aware of the cultural contexts in their daily educational and clinical activities. CONCLUSIONS: The cultural anthropology sessions in the faculty development program were shown to have enhanced the participants' awareness of cultural contexts. The concept and format of these sessions may be used more widely in faculty development programs.


Assuntos
Educação Médica , Docentes de Medicina , Antropologia Cultural , Pesquisa sobre Serviços de Saúde , Humanos , Universidades
9.
Metabolites ; 12(2)2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-35208208

RESUMO

Metabolomics can help identify candidate biomarker metabolites whose levels are altered in response to disease development or drug administration. However, assessment of the underlying molecular mechanism is challenging considering it depends on the researcher's knowledge. This study reports a novel method for the automated recommendation of keywords known in the literature that may be overlooked by researchers. The proposed method aided in the identification of Medical Subject Headings (MeSH) terms in PubMed using MeSH co-occurrence data. The intended users are biocurators who have identified specific biomarker metabolites from a metabolomics study and would like to identify literature-reported molecular mechanisms that are associated with both the metabolite and their research area of interest. The proposed method finds MeSH terms that co-occur with a MeSH term of the candidate biomarker metabolite as well as a MeSH term of a researcher's known keyword, such as the name of a disease. The connectivity score S was determined using association analysis. Pilot analyses demonstrated that, while the biological significance of the obtained MeSH terms could not be guaranteed, the developed method can be useful for finding keywords to further investigate molecular mechanisms in association with candidate biomarker molecules.

11.
F1000Res ; 11: 1268, 2022.
Artigo em Japonês | MEDLINE | ID: mdl-37638132

RESUMO

Vaccine rollouts have been underway to combat the COVID-19 pandemic globally. Based on ongoing interviews with ten primary care physicians 'in the field', this paper elucidates how in practice the vaccinations were carried out in Japan in 2021 from a cultural anthropological perspective. We examine what the primary care physicians did to prepare for the rollouts, what problems they faced, and how they responded to these problems. Large-scale vaccination projects are supposed to proceed smoothly and quickly, or to have what Anna Tsing calls 'scalability'. In practice, however, they required a variety of tasks for coordination, information sharing, and promotion. Despite feeling stressed by the lack of information and exhausted by the work overload, the primary care physicians carried out the vaccinations as an important service to their patients and communities. The findings of this paper will provide valuable materials for improving future vaccine rollouts.


Assuntos
COVID-19 , Médicos de Atenção Primária , Vacinação , Humanos , COVID-19/prevenção & controle , População do Leste Asiático , Pandemias , Vacinação/métodos
12.
BMC Med Educ ; 21(1): 574, 2021 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-34772406

RESUMO

BACKGROUND: Effective social and behavioral sciences teaching in medical education requires integration with clinical experience, as well as collaboration between social and behavioral sciences experts and clinical faculty. However, teaching models for achieving this integration have not been adequately established, nor has the collaboration process been described. This study aims to propose a collaborative clinical case conference model to integrate social and behavioral sciences and clinical experience. Additionally, we describe how social and behavioral science experts and clinical faculty collaborate during the development of the teaching method. METHODS: A team of medical teachers and medical anthropologists planned for the development of a case conference based on action research methodology. The initial model was planned for a 3-h session, similar to a Clinicopathological Conference (CPC) structure. We evaluated each session based on field notes taken by medical anthropologists and post-session questionnaires that surveyed participants' reactions and points of improvement. Based on the evaluation, a reflective meeting was held to discuss revisions for the next trial. We incorporated the development process into undergraduate medical curricula in clinical years and in a postgraduate and continuous professional development session for residents and certified family physicians in Japan. We repeated the plan-act-observe-reflection process more than 15 times between 2015 and 2018. RESULTS: The development of the collaborative clinical case conference model is summarized in three phases: Quasi-CPC, Interactive, and Co-constructive with unique structures and underlying paradigms. The model successfully contributed to promoting the participants' recognition of the clinical significance of social and behavioral sciences. The case preparation entailed unique and significant learning of how social and behavioral sciences inform clinical practice. The model development process promoted the mutual understanding between clinical faculty and anthropologists, which might function as faculty development for teachers involved in social and behavioral sciences teaching in medical education. CONCLUSIONS: The application of appropriate conference models and awareness of their underlying paradigms according to educational situations promotes the integration of social and behavioral sciences with clinical medicine education. Faculty development regarding social and behavioral sciences in medical education should focus on collaboration with scholars with different paradigmatic orientations.


Assuntos
Ciências do Comportamento , Educação Médica , Currículo , Docentes , Docentes de Medicina , Pesquisa sobre Serviços de Saúde , Humanos , Ensino
13.
J Gen Fam Med ; 22(6): 316-326, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34226858

RESUMO

Background: Within the vague system of primary care and COVID-19 infection control in Japan, we explored how primary care (PC) physicians exhibited adaptive performance in their institutions and communities to cope with the COVID-19 pandemic from January to May 2020. Methods: Narrative analysis conducted by a team of medical professionals and anthropologists. We purposefully selected 10 PC physicians in community-based hospitals and clinics and conducted a total of 17 individual and group interviews. The verbatim transcript data were analyzed using the conceptual framework of adaptive performance. Results: We identified three "phases" of the time period (January-May 2020). In Phase 1, PC physicians initially perceived the disease as a problem unrelated to them. In Phase 2, the Diamond Princess outbreak triggered adaptive performance of the physicians, who began to deal with medical issues related to COVID-19 by using social networking services and applying the collected information to their organization and/or communities. Following this, in Phase 3, the PC physicians' adaptive performance in their own communities and institutions emerged in the face of the pandemic. Reflecting their sensitivity to local context, the PC physicians were seen to exhibit adaptive performance through dealing with context-dependent problems and relationships. Conclusions: PC physicians exhibited adaptive performance in the course of coping with the realities of COVID-19 in shifting phases and in differing localities in the early stages of the pandemic. The trajectories of adaptive performance in later stages of the pandemic remain to be seen.

14.
J Diabetes Investig ; 12(12): 2232-2241, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34032389

RESUMO

AIMS/INTRODUCTION: Diabetes patients develop a variety of metabolic abnormalities in addition to hyperglycemia. However, details regarding change in various metabolites after comprehensive diabetes treatment remain unknown. This study aimed to identify the short-term change in metabolome in inpatients who were subject to comprehensive diabetes treatment, using gas chromatography/mass spectrometry-based non-target metabolomics techniques. MATERIALS AND METHODS: Participants of the present study were randomly recruited from the patients with type 2 diabetes hospitalized due to problems with glycemic control (n = 31) and volunteers without diabetes (n = 30), both of whom were aged between 20 and 75 years. A metabolomic analysis of fasting plasma samples on the 2nd (pre-treatment) and 16th hospital (post-treatment) day with gas chromatography/mass spectrometry using a multiple reaction monitoring mode was carried out. RESULTS: A principal component analysis showed that metabolome of fasting plasma was different between individuals with and without diabetes. The metabolome of fasting plasma in diabetes patients after treatment was different from that of pre-treatment, as well as individuals without diabetes. Many amino acids (proline, glycine, serine, threonine, methionine, pyroglutamic acid, glutamine and lysine) were significantly increased by >10% after administering the inpatient diabetes treatment. A hierarchical clustering analysis showed that in the case of patients with markedly decreased monosaccharide levels and increased 1,5-anhydroglucitol, the levels of amino acids increased more significantly. CONCLUSIONS: After a 2-week comprehensive treatment, the plasma levels of various amino acids increased in conjunction with the reduction in monosaccharide levels in poorly controlled type 2 diabetes patients.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Cromatografia Gasosa-Espectrometria de Massas , Controle Glicêmico/estatística & dados numéricos , Metaboloma , Metabolômica/métodos , Adulto , Idoso , Aminoácidos/sangue , Estudos de Casos e Controles , Análise por Conglomerados , Diabetes Mellitus Tipo 2/tratamento farmacológico , Jejum/sangue , Feminino , Controle Glicêmico/métodos , Humanos , Pacientes Internados/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Monossacarídeos/sangue , Análise de Componente Principal , Estudos Prospectivos , Adulto Jovem
15.
J Biosci Bioeng ; 131(2): 207-212, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33051155

RESUMO

Finding peaks in chromatograms and determining their start and end points (peak picking) is a core task in chromatography based biotechnology. Construction of peak-picking neural networks by deep learning was, however, hampered from the preparation of exact peak-picked or "labeled" chromatograms since the exact start and end points were often unclear in overlapping peaks in real chromatograms. We present a design of a fake chromatogram generator, along with a method for deep learning of peak-picking neural networks. Fake chromatograms were generated by generation of fake peaks, random sampling of peak positions from feature distributions, and merging with real blank sample chromatograms. Information on the exact start and end points, as labeled on the fake chromatograms, were effective for training and evaluating peak-picking neural networks. The peak-picking neural networks constructed herein outperformed conventional peak-picking software and showed comparable performance with that of experienced operators for processing the widely targeted metabolome data. Results of this study indicate that generation of fake chromatograms would be crucial for developing peak-picking neural networks and a key technology for further improvement of peak picking neural networks.


Assuntos
Aprendizado Profundo , Metabolômica/métodos , Cromatografia , Software
16.
Explore (NY) ; 16(3): 145-151, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31843394

RESUMO

PURPOSE: Doctors' illness experiences can deeply influence not only their perceptions of illness and roles but also their medical practice. Researchers and doctors have sought to understand what happens when doctors become patients. However, currently, literature reviews focused exclusively on their illness experiences are lacking. This review examines academic literature and combines it with illness narratives (i.e., pathographies) written by doctors to elucidate the unknown about doctors' experiences and its subsequent influence on medical practice. METHODS: An electronic search of the databases Academic Search Complete, Google Scholar, PubMed, ProQuest, and Ichushi-Web was conducted using relevant keywords. The literature reviewed included studies that described doctors' illness experiences or doctors' perspectives on their experiences of being patients. RESULTS: Previous studies showed that doctors' disease prognoses are generally better than or similar to those of patients belonging to the general population. However, doctors' documented illness experiences are multi-dimensional and have several common themes. These include the concept of the 'medical self' (behaving as a doctor despite being a patient) and 'role reversal' (the doctor adjusting to the patient role). The other elements of their experiences include barriers to health care, self-treatment and self-doctoring, presenteeism, and 'wounded healers' (those who can heal others using the wisdom from their illness experiences). Most previous literature has omitted the sociocultural and historical dispositions of doctors and their biomedical perspectives of their own afflictions, even though these strongly impact their illness experiences. CONCLUSION: Further research that re-contextualises the meaning of illness for doctors is necessary.


Assuntos
Atitude do Pessoal de Saúde , Papel do Médico/psicologia , Médicos/psicologia , Empatia , Humanos , Comportamento de Doença , Presenteísmo , Autocuidado
17.
Metab Eng ; 51: 43-49, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30176394

RESUMO

Precise measurement of sugar phosphates in glycolysis and the pentose phosphate (PP) pathway for 13C-metabolic flux analysis (13C-MFA) is needed to understand cancer-specific metabolism. Although various analytical methods have been proposed, analysis of sugar phosphates is challenging because of the structural similarity of various isomers and low intracellular abundance. In this study, gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS) is applied to sugar phosphate analysis with o-(2,3,4,5,6-pentafluorobenzyl) oxime (PFBO) and trimethylsilyl (TMS) derivatization. Optimization of the GC temperature gradient achieved baseline separation of sugar phosphates in 31 min. Mass spectra showed the predominant generation of fragment ions containing all carbon atoms in the sugar phosphate backbone. The limit of detection of pentose 5-phosphates and hexose 6-phosphates was 10 nM. The method was applied to 13C-labeling measurement of sugar phosphates for 13C-MFA of the MCF-7 human breast cancer cell line. 13C-labeling of sugar phosphates for 13C-MFA improved the estimation of the net flux and reversible flux of bidirectional reactions in glycolysis and the PP pathway.


Assuntos
Linhagem Celular Tumoral , Análise do Fluxo Metabólico/métodos , Fosfatos Açúcares/análise , Metabolismo Energético , Feminino , Fluorbenzenos , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Isomerismo , Células MCF-7 , Oximas , Espectrometria de Massas por Ionização por Electrospray , Compostos de Trimetilsilil/metabolismo
18.
Mass Spectrom (Tokyo) ; 8(1): A0073, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32010541

RESUMO

Isotope labeling measurements using mass spectrometry can provide informative insights on the metabolic systems of various organisms. The detailed identification of carbon positions included in the fragment ions of dicarboxylic and tricarboxylic acids in central carbon metabolism is needed for precise interpretation of the metabolic states. In this study, fragment ions containing the carbon backbone cleavage of dicarboxylic and tricarboxylic in the Krebs cycle were investigated by using gas chromatography (GC)-electron ionization (EI)-MS and GC-EI-MS/MS. The positions of decarboxylation in the dicarboxylic and tricarboxylic acids were successfully identified by analyses using position-specific 13C-labeled standards prepared by in vitro enzymatic reactions. For example, carboxyl groups of C1 and C6 of trimethylsilyl (TMS)- and tert-butyldimethylsilyl (TBDMS)-derivatized malic and citric acids were primarily cleaved by EI. MS/MS analyses were also performed, and fragment ions of TBDMS-citric and α-ketoglutaric acids (αKG) with the loss of two carboxyl groups in collision-induced dissociation (CID) were observed.

19.
Sci Rep ; 8(1): 17915, 2018 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30559391

RESUMO

D-amino acids (D-AAs) have various biological activities, such as activation of N-methyl-D-aspartic acid (NMDA) receptor as a co-agonist by D-Ser. Since several free D-AAs are released in the broth monocultured with bacterium and D-AAs are probably utilized for bacterial communication, we presume that intestinal microbiota releases several kinds of free D-AAs, which may be involved in the hosts' health. However, presently, only four free D-AAs have been found in the ceacal lumen, but not in the colonic lumen. Here, we showed, by simultaneous analysis of chiral AAs using high-sensitivity liquid chromatography-tandem mass spectrometry (LC-MS/MS), that 12 free D-AAs (D-Ala, D-Arg, D-Asp, D-Gln, D-Glu, D-allo-Ile, D-Leu, D-Lys, D-Met, D-Phe, D-Ser, and D-Trp) are produced by intestinal microbiota and identified bacterial groups belonging to Firmicutes as the relevant bacterial candidates.


Assuntos
Aminoácidos/metabolismo , Bactérias/metabolismo , Microbioma Gastrointestinal/fisiologia , Intestinos/microbiologia , Animais , Cromatografia Líquida/métodos , Camundongos , Camundongos Endogâmicos ICR , Espectrometria de Massas em Tandem/métodos
20.
Anal Bioanal Chem ; 408(22): 6133-40, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27342798

RESUMO

Stable isotope labeling experiments using mass spectrometry have been employed to investigate carbon flow levels (metabolic flux) in mammalian, plant, and microbial cells. To achieve a more precise (13)C-metabolic flux analysis ((13)C-MFA), novel fragmentations of tert-butyldimethylsilyl (TBDMS)-amino acids were investigated by gas chromatography-tandem mass spectrometry (GC-MS/MS). The product ion scan analyses of 15 TBDMS-amino acids revealed 24 novel fragment ions. The amino acid-derived carbons included in the five fragment ions were identified by the analyses of (13)C-labeled authentic standards. The identification of the fragment ion at m/z 170 indicated that the isotopic abundance of S-methyl carbon in methionine could be determined from the cleavage of C5 in the precursor of [M-159](+) (m/z 218). It was also confirmed that the precision of (13)C-MFA in Escherichia coli central carbon metabolism could be improved by introducing (13)C-labeling data derived from novel fragmentations. Graphical Abstract Novel collision-induced dissociation fragmentations of tert-butyldimethylsilyl amino acids were investigated and identified by GC-MS/MS.


Assuntos
Aminoácidos/metabolismo , Escherichia coli/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Análise do Fluxo Metabólico/métodos , Aminoácidos/análise , Carbono/análise , Carbono/metabolismo , Escherichia coli/química , Compostos de Organossilício/análise , Compostos de Organossilício/metabolismo , Espectrometria de Massas em Tandem
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