10 research outputs found
Allorecognition behavior of slime mold plasmodium—Physarum rigidum slime sheath-mediated self-extension model
When allogeneic plasmodia of Myxomycetes encounter each other, they fuse or avoid each other depending on the combination, indicating that plasmodia can recognize self and non-self. The mechanisms of allorecognition are not fully understood from the perspective of behavior. In the present study design, Physarum rigidum geographical strains naturally encountered each other with the aim of formulating a model of allorecognition behavior. The plasmodia of P. rigidum can recognize each other by touching the cell membrane surface. However, contact is not necessary. Cases involving the absence of contact occur by the slime sheath of hyaline mucus that covers plasmodium. This so-called non-contact allorecognition has distinct characteristics regardless of distance and is faster compared to that involving contact. These facts suggest that the plasmodia of one P. rigidum can recognize others and can rapidly and safely decide whether to avoid or fuse with other plasmodia, using the non-contact allorecognition. Previous studies on P. polycephalum have regarded the slime sheath as a repellent or as an external memory for self. These studies advocated that the principle of the plasmodium is basically avoidance of other individuals. In this study, we propose the self-extension model based on data of the allorecognition behavior of P. rigidum. According to the model, the slime sheath functions as a signal that disperses information about self into the environment. Self-extension by the slime sheath enables non-contact allorecognition
Spectral evolution of GRB 060904A observed with Swift and Suzaku -- Possibility of Inefficient Electron Acceleration
We observed an X-ray afterglow of GRB 060904A with the Swift and Suzaku
satellites. We found rapid spectral softening during both the prompt tail phase
and the decline phase of an X-ray flare in the BAT and XRT data. The observed
spectra were fit by power-law photon indices which rapidly changed from to within a few hundred
seconds in the prompt tail. This is one of the steepest X-ray spectra ever
observed, making it quite difficult to explain by simple electron acceleration
and synchrotron radiation. Then, we applied an alternative spectral fitting
using a broken power-law with exponential cutoff (BPEC) model. It is valid to
consider the situation that the cutoff energy is equivalent to the synchrotron
frequency of the maximum energy electrons in their energy distribution. Since
the spectral cutoff appears in the soft X-ray band, we conclude the electron
acceleration has been inefficient in the internal shocks of GRB 060904A. These
cutoff spectra suddenly disappeared at the transition time from the prompt tail
phase to the shallow decay one. After that, typical afterglow spectra with the
photon indices of 2.0 are continuously and preciously monitored by both XRT and
Suzaku/XIS up to 1 day since the burst trigger time. We could successfully
trace the temporal history of two characteristic break energies (peak energy
and cutoff energy) and they show the time dependence of while the following afterglow spectra are quite stable. This fact
indicates that the emitting material of prompt tail is due to completely
different dynamics from the shallow decay component. Therefore we conclude the
emission sites of two distinct phenomena obviously differ from each other.Comment: 19 pages, 9 figures, accepted for publication in PASJ (Suzaku 2nd
Special Issue
Prescription of anti-influenza drugs in Japan, 2014-2020: A retrospective study using open data from the national claims database.
BackgroundBoth physicians and patients are proactive towards managing seasonal influenza in Japan and six drugs are approved. Although many countries have national influenza surveillance systems, data on nationwide prescription practices of anti-influenza drugs are lacking. Therefore, we aimed to clarify the status of anti-influenza drug use in Japan by analyzing real-world data.MethodsThis retrospective study analyzed open data from the National Database of Health Insurance Claims and Specific Health Checkups, which covers most claims data from national health insurance. We estimated the annual number of patients prescribed anti-influenza drugs, which drugs they were prescribed, the patients' age and sex distribution, drug costs, and regional disparities for the period 2014-2020.ResultsFor 2014-2019, an estimated 6.7-13.4 million patients per year were prescribed anti-influenza drugs, with an annual cost of 22.3-48.0 billion JPY (Japanese Yen). In addition, 21.1-32.0 million rapid antigen tests were performed at a cost of 30.1-47.1 billion JPY. In 2017, laninamivir was the most frequently prescribed anti-influenza drug (48%), followed by oseltamivir (36%), while in 2018, the newly introduced baloxavir accounted for 40.8% of prescriptions. After the emergence of COVID-19, the estimated number of patients prescribed anti-influenza drugs in 2020 dropped to just 14,000. In 2018, 37.6% of prescriptions were for patients aged ConclusionsBased on our clarification of how influenza is clinically managed in Japan, future work should evaluate the clinical and economic aspects of proactively prescribing anti-influenza drugs
Intestinal perforation after nivolumab immunotherapy for a malignant melanoma: a case report
Abstract Background Nivolumab is a monoclonal antibody against programmed death 1 and has become a standard treatment of advanced melanoma because of its durable response and survival benefits. In this report, we present a case of severe intestinal perforation after nivolumab immunotherapy for malignant melanoma. Case presentation A 73-year-old man with stage IV malignant melanoma underwent nivolumab therapy. The patient presented to our hospital because of a progressing abdominal pain. Radiological evaluation revealed evidence of free intraperitoneal air. Therefore, we diagnosed the patient as having an intestinal perforation, which was successfully resolved after surgical treatment. Conclusion Although intestinal perforation after nivolumab immunotherapy is rare, it can be severe and requires early diagnosis and emergency surgery to ensure a favorable prognosis
Mixed epithelial and stromal tumor of the kidney with long-term imaging follow-up
Mixed epithelial and stromal tumor (MEST) of the kidney is a rare benign tumor with malignant potential, and is characterized by epithelial and stromal proliferation with a variety of cellularity and growth pattern. MEST of the kidney is often depicted as a well-defined, solid mass with a cystic component. However, due to the rarity of the disease, there are no reports of its progression in serial imaging examinations. This report presents the case of a 68-year-old woman with MEST who was followed for 13 years by computed tomography (CT). To the best of our knowledge, this is the first report of image findings of MEST of the kidney over a follow-up period longer than 10 years