Effects of Microgravity on Cerebral Hemodynamics

After centuries of wonder, human being finally realized the decisive possibility of going to the moon a little more than 50 years ago, and in 1969 this became a reality, no longer a dream. The human body, however, is designed to live under 1 g as on Earth. Thus, it is important to understand what happens in the human body under microgravity in order to make rapid progress in space development. One of the most serious problems produced by microgravity is a fluid shift from lower to upper body. This cephalad fluid shift may change the hemodynamics in the brain. In this review, effects of actual or simulated microgravity on cerebral blood flow, intracranial pressure, formation of brain edema, and orthostatic intolerance will be discussed. These studies provide us lots of information not only to maintain the health of astronauts but also to treat senile persons who, on rare occasions, sit or stand up

Estimation of above-ground biomass of a tropical forest in Northern Borneo using high-resolution satellite image

Estimating above-ground biomass is important in establishing an applicable methodology of Measurement, Reporting and Verification (MRV) System for Reducing Emissions from Deforestation and Forest Degradation-Plus (REDD+). We developed an estimation model of diameter at breast height (DBH) from IKONOS-2 image that led to above-ground biomass estimation (AGB). The IKONOS image was preprocessed with dark object subtraction and topographic effect correction prior to watershed segmentation for tree crown delineation. Compared to the field observation, the overall segmentation accuracy was 64%. Crown detection percent had a strong negative correlation to tree density. In addition, satellite-based crown area had the highest correlation with the field measured DBH. We then developed the DBH allometric model that explained 74% of the data variance. In average, the estimated DBH was very similar to the measured DBH as well as for AGB. Overall, this method can potentially be applied to estimate AGB over a relatively large and remote tropical forest in Northern Borneo

Cathepsin B in the Growth of Colorectal Cancer: Increased Activity of Cathepsin B in Human Colorectal Cancer

Cathepsin B, a thiol protease, is involved in cancer metastasis. To clarify the role of cathepsin B in tumor progression in human colorectal cancer, the relationship between its activity, immunohistochemical staining, and clinical tumor progression was investigated. Cathepsin B activity in adenocarcinomas was significantly elevated compared with that in the tumor-bearing tissue. Furthermore, the tumor/tumor-bearing tissue (T/Tb) ratio of the activity was significantly higher than that of colorectal adenoma. Immunohistochemical studies demonstrated intense staining in the cancerous tissue. With respect to the clinical stage of tumors, the activity tended to be higher in tumors that had invaded the serosa or subserosa than in those that invaded the proper muscle. The results suggest that cathepsin B participates in the progression of human colorectal cancer, and its increased expression is a sensitive marker of the differentiation between colorectal adenoma and adenocarcinoma.</p

Cathepsin B in the Growth of Colorectal Cancer: Suppressive Effect of Leupeptin on the Growth of DMH-Induced Rat Colon Neoplasm

Cathepsin B, a thiol protease, has been reported to be involved in cancer progression and metastasis. The suppressive effects of two kinds of protease inhibitors, leupeptin and dietary camostate (FOY-305), on tumorigenesis and progression in 1, 2-dimethylhydrazine (DMH)-induced rat colon neoplasm were examined in relation to tissue cathepsin B activity. Male Donryu rats were treated with leupeptin or FOY-305 during or after the administration of DMH. There were no significant differences in average tumor numbers among all DMH-treated groups. However, the percentage of small tumors was significantly higher in the group in which leupeptin was supplied during DMH administration. This trend was not recognized in the FOY-305-treated groups. The ratio of cathepsin B activity in the tumors to that in the tumor-bearing tissue (T/Tb) was significantly increased with increasing tumor size (P = 0.009). The cathepsin B activity levels in the tumor-bearing mucosa in the groups which received leupeptin or FOY-305 following DMH treatment were both significantly lower than that in the group which received neither protease inhibitor (P = 0.046 and P = 0.0067, respectively). The results obtained indicate that leupeptin may have suppressed tumor growth by lowering the tissue cathepsin B activity.</p

Neutralization of hepatitis B virus with vaccine-escape mutations by hepatitis B vaccine with large-HBs antigen

優れたB型肝炎予防ワクチン開発に成功 --既存ワクチンの弱点克服へ--. 京都大学プレスリリース. 2022-09-07.Although the current hepatitis B (HB) vaccine comprising small-HBs antigen (Ag) is potent and safe, attenuated prophylaxis against hepatitis B virus (HBV) with vaccine-escape mutations (VEMs) has been reported. We investigate an HB vaccine consisting of large-HBsAg that overcomes the shortcomings of the current HB vaccine. Yeast-derived large-HBsAg is immunized into rhesus macaques, and the neutralizing activities of the induced antibodies are compared with those of the current HB vaccine. Although the antibodies induced by the current HB vaccine cannot prevent HBV infection with VEMs, the large-HBsAg vaccine-induced antibodies neutralize those infections. The HBV genotypes that exhibited attenuated neutralization via these vaccines are different. Here, we show that the HB vaccine consisting of large-HBsAg is useful to compensate for the shortcomings of the current HB vaccine. The combined use of these HB vaccines may induce antibodies that can neutralize HBV strains with VEMs or multiple HBV genotypes

The Plasma Wave Experiment (PWE) on board the Arase (ERG) satellite

The Exploration of energization and Radiation in Geospace (ERG) project aims to study acceleration and loss mechanisms of relativistic electrons around the Earth. The Arase (ERG) satellite was launched on December 20, 2016, to explore in the heart of the Earth’s radiation belt. In the present paper, we introduce the specifications of the Plasma Wave Experiment (PWE) on board the Arase satellite. In the inner magnetosphere, plasma waves, such as the whistler-mode chorus, electromagnetic ion cyclotron wave, and magnetosonic wave, are expected to interact with particles over a wide energy range and contribute to high-energy particle loss and/or acceleration processes. Thermal plasma density is another key parameter because it controls the dispersion relation of plasma waves, which affects wave–particle interaction conditions and wave propagation characteristics. The DC electric field also plays an important role in controlling the global dynamics of the inner magnetosphere. The PWE, which consists of an orthogonal electric field sensor (WPT; wire probe antenna), a triaxial magnetic sensor (MSC; magnetic search coil), and receivers named electric field detector (EFD), waveform capture and onboard frequency analyzer (WFC/OFA), and high-frequency analyzer (HFA), was developed to measure the DC electric field and plasma waves in the inner magnetosphere. Using these sensors and receivers, the PWE covers a wide frequency range from DC to 10 MHz for electric fields and from a few Hz to 100 kHz for magnetic fields. We produce continuous ELF/VLF/HF range wave spectra and ELF range waveforms for 24 h each day. We also produce spectral matrices as continuous data for wave direction finding. In addition, we intermittently produce two types of waveform burst data, “chorus burst” and “EMIC burst.” We also input raw waveform data into the software-type wave–particle interaction analyzer (S-WPIA), which derives direct correlation between waves and particles. Finally, we introduce our PWE observation strategy and provide some initial results

Transarterial chemoembolization with miriplatin-lipiodol emulsion for neuroendocrine metastases of the liver

Miriplatin, a cisplatin derivative with a high affinity for iodized oil, is a novel chemotherapeutic agent designed for use in the transarterial treatment of hepatocellular carcinoma. This case report describes our experience with transarterial chemoembolization (TACE) using miriplatin in 2 patients with neuroendocrine liver metastases. A 38-year-old man with multiple neuroendocrine liver metastases was treated by whole liver chemoembolization, and a 35-year-old woman with a single hepatic lesion was treated by superselective chemoembolization. No serious adverse events were noted during the interventional procedures, or during the observation period of 3 mo in either patient. Sufficient iodized oil uptake was observed in the hypervascular lesions on the unenhanced computed tomography (CT) at 7 d after the procedure. Contrast-enhanced CT obtained at 3 mo after chemoembolization revealed that all hepatic lesions were substantially reduced in size irrespective of tumor vascularity or degree of cystic degeneration, although iodized oil accumulation was only marginal for lesions with cystic degeneration. Thus, TACE with miriplatin can be a safe and effective therapeutic option for the treatment of neuroendocrine metastases of the liver

A case of retroperitoneal liposarcoma after delivery with expression of estrogen receptor: Report of a case

Introduction: Liposarcoma is one of the most common soft tissue sarcomas; however, early diagnosis is rare as the tumor remains difficult and unpalpable for a prolonged period of time. Presentation of case: Here we report the first case of retroperitoneal liposarcoma associated with pregnancy and expression of estrogen receptor. A 34-year-old woman experienced persistent abdominal distension after her first delivery. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed a large (40 cm ×35 cm), solid, palpable abdominal mass with fat attenuation displacing the ascending colon and the right kidney to the left. Laparotomy and an en-bloc resection of the tumor were performed; further, right nephrectomy and adrenalectomy were required. Histopathology showed a well-differentiated liposarcoma; approximately 10–20% of the tumor cells were ER-positive. Discussion: Retroperitoneal liposarcoma associated with pregnancy is an extremely rare occurrence. Surgical resection is unquestionably the first choice of treatment, but complete resection is sometimes impossible due to the volume and depth of invasion of the tumor. In such cases, additional therapy for liposarcoma is important to improve prognosis. Thus, this report highlights the need for further research into hormone therapy. Conclusion: Retroperitoneal liposarcoma has a high local recurrence rate due to the difficulty in complete surgical resection; therefore, additional hormone therapy is important for improving the prognosis

Substrate Stiffness Influences Doxorubicin-Induced p53 Activation via ROCK2 Expression

The physical properties of the extracellular matrix (ECM), such as stiffness, are involved in the determination of the characteristics of cancer cells, including chemotherapy sensitivity. Resistance to chemotherapy is often linked to dysfunction of tumor suppressor p53; however, it remains elusive whether the ECM microenvironment interferes with p53 activation in cancer cells. Here, we show that, in MCF-7 breast cancer cells, extracellular stiffness influences p53 activation induced by the antitumor drug doxorubicin. Cell growth inhibition by doxorubicin was increased in response to ECM rigidity in a p53-dependent manner. The expression of Rho-associated coiled coil-containing protein kinase (ROCK) 2, which induces the activation of myosin II, was significantly higher when cells were cultured on stiffer ECM substrates. Knockdown of ROCK2 expression or pharmacological inhibition of ROCK decreased doxorubicin-induced p53 activation. Our results suggest that a soft ECM causes downregulation of ROCK2 expression, which drives resistance to chemotherapy by repressing p53 activation