Diffusion of Water in Bentonite

Because of the low permeability and the high sorption coefficient, compacted sodium bentonite has been proposed as an effective backfill material in the repository of high-level radioactive waste. The only possible mechanism of nuclide transport in bentonite must be the diffusion. The diffusivity has been considered to have a close relationship with the retardation factor and the self-diffusivity of water. Then, we performed the experiments to determine the self-diffusivity of water in bentonite by using tritiated water as a tracer. The obtained self-diffusivity can be written as Da= (3.4 ± 0.2) × 10-6 [cm²/s] under the condition of temperature T= 25°C and compacted density of bentonite ρ= 2.7 [g/cm³]. It was revealed quantitatively that the self-diffusivity of water in bentonite is much smaller than that of free water (2.13 × 10-5 [cm²/s] at T= 25°C). Also discussed is the analysis of experimental results on the basis of a new solution derived for the diffusion in one dimensional finite zone

Large gastrointestinal stromal tumor and advanced adenocarcinoma in the rectum coexistent with an incidental prostate carcinoma: A case report

AbstractINTRODUCTIONGastrointestinal stromal tumors (GISTs) are the leading mesenchymal neoplasia in the gastrointestinal tract, but GIST arising from the rectum is rare. When a secondary neoplasia coexists in the vicinity of a rectal GIST, more aggressive treatment strategies may be needed to cure the diseases.PRESENTATION OF CASEWe herein describe a 76-year-old man with a large gastrointestinal stromal tumor along with an advanced adenocarcinoma in the rectum that coexisted with prostate carcinoma. Preoperative examination revealed an advanced adenocarcinoma of the upper rectum and a large pelvic mass suggestive of a GIST or a neuroendocrine tumor arising from the anterior wall of the lower rectum. To eradicate the tumor, total pelvic exenteration with ureterocutaneous fistula was carried out after obtaining written informed consent. Immuhistochemical studies revealed the concurrence of an advanced rectal cancer (T3, N1, M0) and a malignant GIST (c-kit-positive, CD34-positive, vimentin-positive, and CAM5.2-negative), and an incidental prostatic acinar adenocarcinoma. The patient was given adjuvant chemotherapy with imatinib and remains disease-free as of 12 months after surgery.DISCUSSIONA PubMed search for the case of coexistence of GIST with two other malignancies revealed only four cases, making this very rare condition.CONCLUSIONRadical surgery with perioperative adjuvant chemotherapy using tyrosine kinase inhibitors is the choice for treatment of large GISTs with a malignant potential. Our report suggests that aggressive surgical approach would be feasible, when a secondary tumor is present near the GIST

Perioperative Clinical Course Variables Associated with Length of Hospital Stay after Primary Intracranial Meningioma Resection

The relationship between perioperative clinical course variables and postoperative length of hospital stay (LOS) in patients undergoing primary intracranial meningioma resection has not been fully elucidated. We therefore aimed to identify the perioperative clinical course variables that predict postoperative LOS in such patients. We retrospectively collected data concerning demographics, tumor characteristics, and perioperative clinical course variables in 76 patients who underwent primary intracranial meningioma resection between January 2010 and December 2019, and tested for associations with postoperative LOS. Univariate analyses showed that younger age, fewer days to postoperative initiation of standing/walking, preoperative independence in activities of daily living (ADL), and ADL independence one week after surgery were associated with shorter postoperative LOS. Multiple regression analyses with these factors identified that days to stand/walk initiation and ADL independence one week after surgery were associated with postoperative LOS. Based on these results, we conclude that rehabilitation programs that promote early mobilization and the early acquisition of independence may reduce postoperative LOS in patients who undergo primary intracranial meningioma resection

Gene Expression and Protein Synthesis in Mitochondria Enhance the Duration of High-Speed Linear Motility in Boar Sperm

Sperm motility patterns are continuously changed after ejaculation to fertilization in the female tract. Hyperactivated motility is induced with high glucose medium in vitro or the oviduct fluids in vivo, whereas sperm maintain linear motility in the seminal plasma or the uterine fluids containing low glucose. Therefore, it is estimated that sperm motility patterns are dependent on the energy sources, and the mitochondrial oxidative phosphorylation is activated to produce ATP in low glucose condition. To elucidate these hypotheses, boar sperm was incubated in different energy conditions with the transcription and translation inhibitors in vitro. Sperm motility parameters, mitochondrial activity, ATP level, gene expression and protein synthesis were analyzed. Sperm progressive motility and straight-line velocity were significantly increased with decreasing glucose level in the incubation medium. Moreover, the mitochondrial protein turnover meaning transcription and translation from mitochondrial genome in sperm is activated during incubation. Incubation of sperm with mitochondrial translation inhibitor (D-chloramphenicol) suppressed mitochondrial protein synthesis, mitochondrial activity and ATP level in sperm and consequently reduced the linear motility speed, but not the motility. Thus, it is revealed that the mitochondrial central dogma is active in sperm, and the high-speed linear motility is induced in low glucose condition via activating the mitochondrial activity for ATP generation.This work was supported in part by Livestock Promotional Funds of Japan Racing Association (JRA) grant no. H30-279 and by Hiroshima Cryopreservation Service Co., grant no. H30-1 (to MS). ZZ was supported by China Scholarship Council during a visit of “Zhendong Zhu” to Hiroshima University (#CSC201706300110).The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fphys.2019.00252/full#supplementary-materia

Importin Alpha Subtypes Determine Differential Transcription Factor Localization in Embryonic Stem Cells Maintenance

SummaryWe recently demonstrated that the expression of the importin α subtype is switched from α2 to α1 during neural differentiation in mouse embryonic stem cells (ESCs) and that this switching has a major impact on cell differentiation. In this study, we report a cell-fate determination mechanism in which importin α2 negatively regulates the nuclear import of certain transcription factors to maintain ESC properties. The nuclear import of Oct6 and Brn2 was inhibited via the formation of a transport-incompetent complex of the cargo bound to a nuclear localization signal binding site in importin α2. Unless this dominant-negative effect was downregulated upon ESC differentiation, inappropriate cell death was induced. We propose that although certain transcription factors are necessary for differentiation in ESCs, these factors are retained in the cytoplasm by importin α2, thereby preventing transcription factor activity in the nucleus until the cells undergo differentiation

An Up-to-Date Anti-Cancer Treatment Strategy Focusing on HIF-1α Suppression: Its Application for Refractory Ovarian Cancer

Hypoxia inducible factor-1α (HIF-1α) predominantly determines the transcriptional activity of HIF-1, which induces the certain genetic expressions to participate in the proliferation and progression of the tumor. It is supposed that HIF-1α is also an extremely important factor in cancer treatment. Based on the results of our recent analyses using ovarian tumors, which indicated the close association of HIF-1α expression with the acquisition of malignancy and the characterization of histology, we further investigated the possibility of a new strategy of cancer therapy that targeted HIF-1α inhibition in the ovarian carcinoma. The cell line HUOCA-II, which originates from the refractory ovarian clear cell adenocarcinoma, was treated with rapamycin. The inhibitory effect of HIF-1α was analyzed by immunohistochemistry and western blotting. It was demonstrated that inhibition of HIF-1α and vascular endothelial growth factor (VEGF) expressions would lead to the down-regulation of tumor cell proliferation. Interestingly, there was little or no change in GLUT-1 expression by rapamycin administration. Thus, the inhibition of GLUT-1 may also be a key for the new strategy of cancer therapy as well as HIF-1α and VEGF

Transoral surgery for superficial head and neck cancer: National Multi‐Center Survey in Japan

Head and neck cancers, especially in hypopharynx and oropharynx, are often detected at advanced stage with poor prognosis. Narrow band imaging enables detection of superficial cancers and transoral surgery is performed with curative intent. However, pathological evaluation and real-world safety and clinical outcomes have not been clearly understood. The aim of this nationwide multicenter study was to investigate the safety and efficacy of transoral surgery for superficial head and neck cancer. We collected the patients with superficial head and neck squamous cell carcinoma who were treated by transoral surgery from 27 hospitals in Japan. Central pathology review was undertaken on all of the resected specimens. The primary objective was effectiveness of transoral surgery, and the secondary objective was safety including incidence and severity of adverse events. Among the 568 patients, a total of 662 lesions were primarily treated by 575 sessions of transoral surgery. The median tumor diameter was 12 mm (range 1–75) endoscopically. Among the lesions, 57.4% were diagnosed as squamous cell carcinoma in situ. The median procedure time was 48 minutes (range 2–357). Adverse events occurred in 12.7%. Life-threatening complications occurred in 0.5%, but there were no treatment-related deaths. During a median follow-up period of 46.1 months (range 1–113), the 3-year overall survival rate, relapse-free survival rate, cause-specific survival rate, and larynx-preservation survival rate were 88.1%, 84.4%, 99.6%, and 87.5%, respectively. Transoral surgery for superficial head and neck cancer offers effective minimally invasive treatment

Better Sleep in the ICU for Preventing Postoperative Delirium

In their interesting review, Dr Flinn and colleagues show the prophylactic strategy, diagnosis, and practical management of postoperative delirium, which has been reported to be independently associat..