HPF1-dependent PARP activation promotes LIG3-XRCC1-mediated backup pathway of Okazaki fragment ligation

DNA ligase 1 (LIG1) is known as the major DNA ligase responsible for Okazaki fragment joining. Recent studies have implicated LIG3 complexed with XRCC1 as an alternative player in Okazaki fragment joining in cases where LIG1 is not functional, although the underlying mechanisms are largely unknown. Here, using a cell-free system derived from Xenopus egg extracts, we demonstrated the essential role of PARP1-HPF1 in LIG3-dependent Okazaki fragment joining. We found that Okazaki fragments were eventually ligated even in the absence of LIG1, employing in its place LIG3-XRCC1, which was recruited onto chromatin. Concomitantly, LIG1 deficiency induces ADP-ribosylation of histone H3 in a PARP1-HPF1-dependent manner. The depletion of PARP1 or HPF1 resulted in a failure to recruit LIG3 onto chromatin and a subsequent failure in Okazaki fragment joining in LIG1-depleted extracts. Importantly, Okazaki fragments were not ligated at all when LIG1 and XRCC1 were co-depleted. Our results suggest that a unique form of ADP-ribosylation signaling promotes the recruitment of LIG3 on chromatin and its mediation of Okazaki fragment joining as a backup system for LIG1 perturbation

The research on the problems of health care and living of the aged (Pursuing the cases of home treatment given to the elderly patients for one year after their discharge)

退院後の生活に目を向けた適切な退院指導がなされることは、高齢患者が安心して在宅療養を送る上で、重要な意味を持つ。そこで病院から在宅療養に移行した70歳以上の高齢者の抱える問題を4回に渡って1年間調査し、これまでに退院時、3ヵ月後、6ヵ月後の調査結果を報告した。本稿では1年を通じて回答のあった53名について健康と生活上の問題の変化を分析し、考察した。在宅療養に移行した高齢者の健康状態と生活上の問題は、ほぼ一致して退院後6ヵ月から1年後までに変化を認め、特に日常生活上の問題は著しく増加した。その原因として病状の悪化との関連が考えられた。また、高齢者の問題についての意識は、研究者の専門的な問題意識に比べて低かった。従って入院中に退院後の生活を予測することには限界があり、今後は退院指導の充実と伴に在宅サービスとの連携が重要であることを認めた。We planned to make emerge the problems felt by the elderly patients of 70 years and over given home treatment. As a means of our research, four times a year we sent a questinnaire to the aged who had been discharged. After collecting the answers of the questionnaires, we decided to focus on the 53 elderly patients who answered all four questionnaires, and then tried to make their problems emerge. The contents of the questionnaires were about their health care in a year and how their daily life changed. We can see that the condition of the elderly patients under home treatment and their living problems have changed almost without exceptions six months to a year after their discharge. Especially the number of the problems in their daily life increased remarkably. These results might be considered to be caused by the aggravation of their diseases. In addition, the elderly patients are not as conscious of their own problems as a specialist with a critical mind. Therefore, there is a limit to estimating the change in lifestyle of a discharged patient while they remain hospitalized. We consider it essential to get full discharge-care closely connected with home service for elderly patients

The effective nursing educational plan for the elderly at hospital discharge. - through the questionnaires for the nurses and the elderly patients -

近年の急速な高齢化社会にともない複数の疾病や種々の障害をもちながら自宅で療養する高齢者が増加してきている。このような状況でいったん入院療養した高齢者が自宅へ帰り生活をしていくにはかなりの困難が予測される。高齢者が退院し自宅での生活にスムーズに適応できるか否かは看護婦の退院指導の良否に関わってくる。そこで指導側の看護婦の指導計画や指導方法、内容について調査すると共に受け手の患者の指導希望内容との比較を行い有効な退院指導のあり方を検討した。患者の心配事や援助や相談の希望内容と看護婦の重要とする指導内容はほぼ同様の内容であった。その内容は日常生活に関すること、病気や健康に関することが多かった。看護婦の退院指導の計画でカンファレンスをしている看護婦はしていない看護婦に比べ指導内容の経済的なこと、趣味や生きがいに関する事、生活環境、家族の協力に関することを重要とすると回答したものが有意に多かった。The elderly with chronic disease or handicaps who receive nursing home care is currently increasing. They may have some difficulties in their daily life after hospital discharge. The proper nursing educational plan may determine their post-hospital life without anxiety. The purpose of this study is to find out the effective nursing educational plan for them. Therefore, we investigated the contents of the nursing educational plan for their hospital discharge and what elderly patients need in their post-hospital life. As a result, both contents were similar. Those were about their daily life, disease, health. And there were significantly defferences between well-discussed plan and no discussed plan in the items of economy, hobbies, purpose of life, home environment, family cooperation. Results from this study suggest that more detailed discussion among nurses at hospital discharge is necessary to determine the individual nursing educational plan of elderly patients in their post-hospital life

Local Control of Squamous Cell Carcinoma of the Cervix Treated with CT-based Three-dimensional Image-Guided Brachytherapy with or without Central Shielding

The purposes of this retrospective study were to analyze local control of squamous cell carcinoma of the cervix treated with computed tomography (CT)-based image-guided brachytherapy (IGBT), as well as the factors affecting local control. A total of 39 patients were analyzed. The prescribed dose to the pelvis was 45-50 Gy with or without central shielding (CS). IGBT was delivered in 1-5 fractions. The total dose for high-risk clinical target volume (HR-CTV) was calculated as the biologically equivalent dose in 2-Gy fractions. The median follow-up period was 29.3 months. The 2-year overall survival and local control rates were 97% and 91%, respectively. In univariate analysis, the dose covering 90% of the HR-CTV (D90) and tumor size were found to be significant factors for local control. The cutoff values of tumor size and D90 for local control were 4.3 cm (area under the curve [AUC] 0.75) and 67.7 Gy (AUC 0.84) in the CS group and 5.3 cm (AUC 0.75) and 73.7 Gy (AUC 0.78) in the group without CS, respectively. However, though the local control of CT-based IGBT was favorable, the results suggested that the dose required for tumor control may differ depending on the presence of CS

Detection of Trypanosoma cruzi DTUs TcI and TcIV in two outbreaks of orally-transmitted Chagas disease in the Northern region of Brazi

This study describes the laboratory investigation of two acute Chagas disease outbreaks that occurred in the riverside communities of Marimarituba and Cachoeira do Arua, in the Santarem municipality, Para State, located in the Northern region of Brazil, and occurred in March 2016 and August 2017, respectively. The generation of data regarding the diversity of Trypanosoma cruzi parasites circulating in the Amazon region is key for understanding the emergence and expansion of Chagas disease. This study aimed to identify T. cruzi Discrete Typing Units (DTUs) involved in two outbreaks of acute Chagas disease (ACD) directly from the patient’s biological sample. Nested and multiplex PCR targeting the 24Sα (rRNA) and mini-exon genes, respectively, were used to identify T. cruzi DTU in blood samples from patients diagnosed with ACD. The samples with positive cPCR were submitted for analysis for T. cruzi DTUs, which included 13 samples from the patients with ACD by oral transmission and two samples collected from two newborns of two women with ACD, from Marimarituba and Cachoeira do Arua. The samples were classified as T. cruzi TcIV, from Marimarituba’s outbreak, and T. cruzi TcI, from Cachoeira do Arua’s outbreak. The molecular identification of T. cruzi may increase understanding of the role of this parasite in Chagas disease’s emergence within the Amazon region, contributing to the improvement of the management of this important, but also neglected, diseas

Two distinct modes of DNMT1 recruitment ensure stable maintenance DNA methylation

Stable inheritance of DNA methylation is critical for maintaining differentiated phenotypes in multicellular organisms. We have recently identified dual mono-ubiquitylation of histone H3 (H3Ub2) by UHRF1 as an essential mechanism to recruit DNMT1 to chromatin. Here, we show that PCNA-associated factor 15 (PAF15) undergoes UHRF1-dependent dual mono-ubiquitylation (PAF15Ub2) on chromatin in a DNA replication-coupled manner. This event will, in turn, recruit DNMT1. During early S-phase, UHRF1 preferentially ubiquitylates PAF15, whereas H3Ub2 predominates during late S-phase. H3Ub2 is enhanced under PAF15 compromised conditions, suggesting that H3Ub2 serves as a backup for PAF15Ub2. In mouse ES cells, loss of PAF15Ub2 results in DNA hypomethylation at early replicating domains. Together, our results suggest that there are two distinct mechanisms underlying replication timing-dependent recruitment of DNMT1 through PAF15Ub2 and H3Ub2, both of which are prerequisite for high fidelity DNA methylation inheritance

Cdk1-mediated DIAPH1 phosphorylation maintains metaphase cortical tension and inactivates the spindle assembly checkpoint at anaphase

Animal cells undergo rapid rounding during mitosis, ensuring proper chromosome segregation, during which an outward rounding force abruptly increases upon prometaphase entry and is maintained at a constant level during metaphase. Initial cortical tension is generated by the actomyosin system to which both myosin motors and actin network architecture contribute. However, how cortical tension is maintained and its physiological significance remain unknown. We demonstrate here that Cdk1-mediated phosphorylation of DIAPH1 stably maintains cortical tension after rounding and inactivates the spindle assembly checkpoint (SAC). Cdk1 phosphorylates DIAPH1, preventing profilin1 binding to maintain cortical tension. Mutation of DIAPH1 phosphorylation sites promotes cortical F-actin accumulation, increases cortical tension, and delays anaphase onset due to SAC activation. Measurement of the intra-kinetochore length suggests that Cdk1-mediated cortex relaxation is indispensable for kinetochore stretching. We thus uncovered a previously unknown mechanism by which Cdk1 coordinates cortical tension maintenance and SAC inactivation at anaphase onset

Tachykinins Stimulate a Subset of Mouse Taste Cells

The tachykinins substance P (SP) and neurokinin A (NKA) are present in nociceptive sensory fibers expressing transient receptor potential cation channel, subfamily V, member 1 (TRPV1). These fibers are found extensively in and around the taste buds of several species. Tachykinins are released from nociceptive fibers by irritants such as capsaicin, the active compound found in chili peppers commonly associated with the sensation of spiciness. Using real-time Ca2+-imaging on isolated taste cells, it was observed that SP induces Ca2+ -responses in a subset of taste cells at concentrations in the low nanomolar range. These responses were reversibly inhibited by blocking the SP receptor NK-1R. NKA also induced Ca2+-responses in a subset of taste cells, but only at concentrations in the high nanomolar range. These responses were only partially inhibited by blocking the NKA receptor NK-2R, and were also inhibited by blocking NK-1R indicating that NKA is only active in taste cells at concentrations that activate both receptors. In addition, it was determined that tachykinin signaling in taste cells requires Ca2+-release from endoplasmic reticulum stores. RT-PCR analysis further confirmed that mouse taste buds express NK-1R and NK-2R. Using Ca2+-imaging and single cell RT-PCR, it was determined that the majority of tachykinin-responsive taste cells were Type I (Glial-like) and umami-responsive Type II (Receptor) cells. Importantly, stimulating NK-1R had an additive effect on Ca2+ responses evoked by umami stimuli in Type II (Receptor) cells. This data indicates that tachykinin release from nociceptive sensory fibers in and around taste buds may enhance umami and other taste modalities, providing a possible mechanism for the increased palatability of spicy foods