Effort for solving difficult problems among university students: Why can they keep making efforts?

University students experience many difficult problems that can lead to mental illness. However, many students can solve these problems by making efforts to confront them. Previous research has showed that social support, generalized self-efficacy, future time perspective, task motivation, and difficulty of the problem are related to solving difficult problems; moreover, some of these factors are connected to each other. In this research, the primary aim was to identify the process of making an effort to confront problems, for which I have developed a hypothetical model. Additionally, students grow up in the four years of their university life. The second aim was to identify the difference between grades in the hypothesized process model. The questionnaire was completed by 399 students (96 freshmen, 95 sophomores, 89 juniors, 69 seniors, and 50 graduates). Covariance structure analysis was performed for the entire sample. The result supported the hypothetical model of making efforts, but some new connections were found. In other words, all psychological factors were complexly connected to each other. Then, I performed covariance structure analysis for my hypothetical model for each grade and compared the models. The results of this comparison showed that the strength of correlation of all factors were different across the grades. Although the factor of future time perspective had no effect on the model for the 1st grade, the effect increased with subsequent grades. Additionally, the effect of the factor of generalized self-efficacy increased with each grade

Total syntheses of disulphated glycosphingolipid SB1a and the related monosulphated SM1a

Total syntheses of two natural sulphoglycolipids, disulphated glycosphingolipid SB1a and the structurally related monosulphated SM1a, are described. They have common glycan sequences and ceramide moieties and are associated with human epithelial carcinomas. The syntheses featured efficient glycan assembly and the glucosyl ceramide cassette as a versatile building block. The binding of the synthetic sulphoglycolipids by the carcinoma-specific monoclonal antibody AE3 was investigated using carbohydrate microarray technology

Synthetic and biochemical studies on the effect of persulfidation on disulfide dimer models of amyloid β42 at position 35 in Alzheimer's etiology

Protein persulfidation plays a role in redox signaling as an anti-oxidant. Dimers of amyloid β42 (Aβ42), which induces oxidative stress-associated neurotoxicity as a causative agent of Alzheimer's disease (AD), are minimum units of oligomers in AD pathology. Met35 can be susceptible to persulfidation through its substitution to homoCys residue under the condition of oxidative stress. In order to verify whether persulfidation has an effect in AD, herein we report a chemical approach by synthesizing disulfide dimers of Aβ42 and their evaluation of biochemical properties. A homoCys-disulfide dimer model at position 35 of Aβ42 formed a partial β-sheet structure, but its neurotoxicity was much weaker than that of the corresponding monomer. In contrast, the congener with an alkyl linker generated β-sheet-rich 8–16-mer oligomers with potent neurotoxicity. The length of protofibrils generated from the homoCys-disulfide dimer model was shorter than that of its congener with an alkyl linker. Therefore, the current data do not support the involvement of Aβ42 persulfidation in Alzheimer's disease

Lipocalin function of E.coli zinT (yodA) protein.

重金属やアミトロール(AT)で発現誘導され、大腸菌ストレス応答タンパク質の一種であるzinT (yodA)は、一次構造比較やX線結晶構造解析による三次元立体構造などから、C末端領域に金属結合部位を持つこと、ABC transporter やlipocalinファミリーと一部相同なアミノ酸配列を持つことが明らかとなっているが、zinTの金属以外の低分子結合能については報告がない。そこで本研究では、大腸菌zinTタンパク質の種々の物質との結合能を、野生型zinTおよびN末端22残基欠損体(ΔN22)を用いて検討した。 まず、zinTの分子内TyrまたはTrp蛍光を指標として、種々の物質を添加に伴う蛍光強度の減少を測定した。低分子化合物としては、(1)ATおよびdNTP(2) 脂肪酸および脂質5種、(3) 複素式化合物3種、(4)芳香族化合物3種を検討し、zinTに対しそれぞれ添加し、30℃、10分間保温後、蛍光スペクトルを測定した。その結果、化合物添加によりzinTの最大蛍光強度は濃度依存的に減少し、特にdNTP, Qurcetinおよび8-ANSで顕著に見られた。また、野生型とΔN22において、蛍光減少の濃度依存性に顕著な差異は見られなかった。以上より、zinTは疎水性低分子化合物結合能(lipocalin活性)を有し、N末端領域のlipocalin活性に対する寄与は少ないことが明らかとなった

The downstream atpE cistron is efficiently translated via its own cis-element in partially overlapping atpB–atpE dicistronic mRNAs in chloroplasts

The chloroplast atpB and atpE genes encode subunits β and ε of the ATP synthase, respectively. They are co-transcribed as dicistronic mRNAs in flowering plants. An unusual feature is an overlap (AUGA) of the atpB stop codon (UGA) with the atpE start codon (AUG). Hence, atpE translation has been believed to depend on atpB translation (i.e. translational coupling). Using an in vitro translation system from tobacco chloroplasts, we showed that both atpB and atpE cistrons are translated from the tobacco dicistronic mRNA, and that the efficiency of atpB translation is higher than that of atpE translation. When the atpB 5′-UTR was replaced with lower efficiency 5′-UTRs, atpE translation was higher than atpB translation. Removal of the entire atpB 5′-UTR arrested atpB translation but atpE translation still proceeded. Introduction of a premature stop codon in the atpB cistron did not abolish atpE translation. These results indicate that atpE translation is independent of atpB translation. Mutation analysis showed that the atpE cistron possesses its own cis-element(s) for translation, located ~25 nt upstream from the start codon

Analysis of T-cell alloantigen response via a direct pathway in kidney transplant recipients with donor-specific antibodies

Donor-specific antibodies (DSAs) are the main cause of graft loss over time. The direct pathway of alloantigen recognition is important in the pathogenesis of acute rejection. Recent studies have suggested that the direct pathway also contributes to the pathogenesis of chronic injury. Nevertheless, there are no reports on T-cell alloantigen response via the direct pathway in kidney recipients with DSAs. We analyzed the T-cell alloantigen response via the direct pathway in kidney recipients with DSAs (DSA+) or without DSAs (DSA−). A mixed lymphocyte reaction assay was implemented to assess the direct pathway response. DSA+ patients showed significantly higher CD8+ and CD4+ T cell responses to donor cells than DSA− patients. Furthermore, proliferating CD4+ T cells showed a marked increase in Th1 and Th17 responses in DSA+ patients than in DSA− patients. In a comparison between anti-donor and third-party responses, the anti-donor CD8+ and CD4+ T cell response was significantly lower than the anti-third-party response. In contrast, the donor-specific hyporesponsiveness was absent in DSA+ patients. Our study demonstrated that DSA+ recipients have a greater potential for developing immune responses against the donor tissues via the direct alloantigen recognition pathway. These data contribute to an understanding of DSAs pathogenicity during kidney transplantation

FXYD3 functionally demarcates an ancestral breast cancer stem cell subpopulation with features of drug-tolerant persisters

乳がんの再発を起こす原因細胞を解明. 京都大学プレスリリース. 2023-11-16.The heterogeneity of cancer stem cells (CSCs) within tumors presents a challenge in therapeutic targeting. To decipher the cellular plasticity that fuels phenotypic heterogeneity, we undertook single-cell transcriptomics analysis in triple-negative breast cancer (TNBC) to identify subpopulations in CSCs. We found a subpopulation of CSCs with ancestral features that is marked by FXYD domain–containing ion transport regulator 3 (FXYD3), a component of the Na⁺/K⁺ pump. Accordingly, FXYD3⁺ CSCs evolve and proliferate, while displaying traits of alveolar progenitors that are normally induced during pregnancy. Clinically, FXYD3⁺ CSCs were persistent during neoadjuvant chemotherapy, hence linking them to drug-tolerant persisters (DTPs) and identifying them as crucial therapeutic targets. Importantly, FXYD3⁺ CSCs were sensitive to senolytic Na⁺/K⁺ pump inhibitors, such as cardiac glycosides. Together, our data indicate that FXYD3⁺ CSCs with ancestral features are drivers of plasticity and chemoresistance in TNBC. Targeting the Na⁺/K⁺ pump could be an effective strategy to eliminate CSCs with ancestral and DTP features that could improve TNBC prognosis

Clinical Evaluation of TRCRapid M.TB for Detection of Mycobacterium tuberculosis Complex in Respiratory and Nonrespiratory Specimens▿

The rapid and accurate diagnosis of tuberculosis is crucial to providing optimal treatment and reducing the spread of infection. We evaluated respiratory and nonrespiratory clinical specimens using a new automated Mycobacterium tuberculosis complex (MTBC) rRNA detection kit (TRCRapid M.TB; Tosoh Bioscience, Tokyo, Japan), which is based on the transcription-reverse transcription concerted reaction (TRC). TRC enables the rapid and completely homogeneous real-time monitoring of isothermal RNA sequence amplification without any postamplification procedures. The results were compared with those obtained by M. tuberculosis culture. A total of 1,155 respiratory specimens and 420 nonrespiratory specimens collected from 1,282 patients were investigated. Of the 45 specimens culture positive for MTBC, 42 were TRC positive, and of the 1,530 specimens culture negative for MTBC, 1,523 were TRC negative. Compared to the results of culture, the overall sensitivity and specificity of TRC were 96.6% and 99.9%, respectively, for respiratory specimens and 87.5% and 98.5%, respectively, for nonrespiratory specimens. The sensitivities of TRC were 100% for smear-positive respiratory and nonrespiratory specimens, 88.9% for smear-negative respiratory specimens, and 80% for smear-negative nonrespiratory specimens. No significant differences in test performance between respiratory and nonrespiratory specimens were observed. The TRC method proved to be clinically useful for the rapid identification of MTBC in respiratory and nonrespiratory specimens and in both smear-positive and smear-negative samples