124 research outputs found
Ultra-high temperature Soret effect in a silicate melt: SiO2 migration to cold side
The Soret effect, temperature gradient driven diffusion, in silicate melts
has been investigated intensively in the earth sciences from the 1980s. The
SiO2 component is generally concentrated in the hotter region of silicate melts
under a temperature gradient. Here, we report that at ultra-high temperatures
above approximately 3000 K, SiO2 becomes concentrated in the colder region of
the silicate melts under a temperature gradient. The interior of an
aluminosilicate glass (63.3SiO2-16.3Al2O3-20.4CaO(mol%)) was irradiated with a
250 kHz femtosecond laser pulse for local heating. SiO2 migrated to the colder
region during irradiation with an 800 pulse (3.2 ms irradiation). The
temperature analysis indicated that migration to the colder region occurred
above 3060 K. In the non-equilibrium molecular dynamics (NEMD) simulation, SiO2
migrated to the colder region under a temperature gradient, which had an
average temperature of 4000 K; this result supports the experimental result.
SiO2 exhibited a tendency to migrate to the colder region at 2400 K in both the
NEMD and experimental study. The second-order like phase transition was
observed at ~ 2000-3400 K when calculated using MD without a temperature
gradient. Therefore, the second-order phase transition could be related to the
migration of SiO2 to colder region. However, the detailed mechanism has not
been elucidated
Roles of Phosphatidic Acid in Virus RNA Replication
Eukaryotic positive-strand RNA [(+)RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+)RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+)RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate
TNFRSF1B A1466G genotype is predictive of clinical efficacy after treatment with a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Currently definitive 5-fluorouracil (5-FU)/cisplatin (CDDP) -based chemotherapy is recognized as one of the most promising treatments for esophageal cancer. A series of studies performed found genetic polymorphisms and the plasma concentration of 5-FU to be predictive of acute severe toxicities and clinical response. Genetic polymorphisms of <it>tumor necrosis factor (TNF) -α </it>and its surface receptors, <it>TNFRSF1A </it>and <it>TNFRSF1B </it>have been examined in terms of susceptibility to various cancers. In this study, genetic polymorphisms of <it>TNFRSF1B </it>gene were evaluated Japanese esophageal squamous cell carcinoma (ESCC) patients treated with the definitive 5-FU/CDDP-based chemoradiotherapy and their predictive values of prognosis or severe acute toxicities were assessed.</p> <p>Methods</p> <p>Forty-six patients with ESCC were treated with the definitive 5-FU/CDDP-based chemoradiotherapy, one course of which consisted of the continuous infusion of 5-FU for days 1-5 and 8-12, the infusion of CDDP on days 1 and 8, and the radiation at 2 Gy/day on days 1-5, 8-12, and 15-19, with a second course repeated after 2-week interval. Genetic polymorphisms of a TNF-α receptor <it>TNFRSF1B </it>gene were determined by a TaqMan<sup>® </sup>MGB probe-based polymerase chain reaction.</p> <p>Results</p> <p>The genotype of <it>TNFSR1B </it>A1466G, but not M196R/T587G or C1493T, was found to be predictive of clinical response, i.e., a complete response or not (p = 0.040). Clinical response was predicted by tumor size (p = 0,002), lymph node metastasis (p = 0.007), distant metastasis (p = 0.001) and disease stage (p < 0.001), but <it>TNFRSF1B </it>A1466G genotype was independent of these factors.</p> <p>Conclusions</p> <p>Genetic polymorphism of <it>TNFRSF1B </it>A1466G was found to be predictive response in Japanese ESCC patients with a definitive 5-FU/CDDP-based chemoradiotherapy. Further clinical investigation with a large number of patients or experiments in vitro should be performed to assess the predictive value of <it>TNFRSF1B </it>A1466G genotype after chemoradiotherapy.</p
Effects of plasma concentrations of 5-fluorouracil on long-term survival after treatment with a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma
<p>Abstract</p> <p>Background</p> <p>A substantial body of literature has accumulated during the past 20 years showing the plasma concentrations of 5-fluorouracil (5-FU) to correlate with clinical response and/or toxicity in colorectal cancer, and head and neck cancer, but little information is available concerning effects on long-term survival. Here, Japanese patients with esophageal squamous cell carcinoma (ESCC) were followed up for 5 years after treatment with a definitive 5-FU/cisplatin (CDDP)-based chemoradiotherapy (CRT), and the association between prognosis and the plasma concentration of 5-FU was evaluated.</p> <p>Methods</p> <p>Forty-nine patients with ESCC, who were treated with a definitive 5-FU/CDDP-based CRT, were enrolled. A course consisted of the continuous infusion of 5-FU at 400 mg/m<sup>2</sup>/day for days 1-5 and 8-12, the infusion of CDDP at 40 mg/m<sup>2</sup>/day on days 1 and 8, and the radiation at 2 Gy/day on days 1 to 5, 8 to 12, and 15 to 19, with a second course repeated after a 2-week interval. Plasma concentrations of 5-FU were determined by high performance liquid chromatography at 5:00 PM on days 3, 10, 38 and 45, and at 5:00 AM on days 4, 11, 39 and 46.</p> <p>Results</p> <p>The overall 5-year survival rate was 42.9%. Age (P = 0.020), body weight (P = 0.019), and disease stage (P = 0.048) affected the survival, and the survival depended on the clinical response assessed at 1 month after the treatment (P = 0.001). Higher plasma concentrations of 5-FU resulted in a better clinical response (P = 0.043), and trended to prolong survival (P = 0.321).</p> <p>Conclusions</p> <p>The long-term survival after treatment with a definitive 5-FU/CDDP-based CRT possibly depends on the plasma concentrations of 5-FU, and further clinical studies with a larger number of cases are needed to clarify the relationship between them.</p
Replacement of cisplatin with nedaplatin in a definitive 5-fluorouracil/cisplatin-based chemoradiotherapy in Japanese patients with esophageal squamous cell carcinoma
Objective: The effects of replacing cisplatin (CDDP) with cis-diammineglycolatoplatinum (nedaplatin, NDP), a second-generation platinum complex, on the pharmacokinetics of 5-fluorouracil (5-FU) were investigated in Japanese patients with esophageal squamous cell carcinoma, who were treated with a definitive 5-FU/CDDP-based chemoradiotherapy
- …