Direct Numerical Simulations of Electrophoresis of Charged Colloids

We propose a numerical method to simulate electrohydrodynamic phenomena in charged colloidal dispersions. This method enables us to compute the time evolutions of colloidal particles, ions, and host fluids simultaneously by solving Newton, advection-diffusion, and Navier--Stokes equations so that the electrohydrodynamic couplings can be fully taken into account. The electrophoretic mobilities of charged spherical particles are calculated in several situations. The comparisons with approximation theories show quantitative agreements for dilute dispersions without any empirical parameters, however, our simulation predicts notable deviations in the case of dense dispersions.Comment: 4pages, 3figures, to appear in Phys. Rev. Let

Generation of cytotoxic T cell responses to an HLA-A24 restricted epitope peptide derived from wild-type p53

Mutations in the p53 gene are the most common genetic alterations found in human tumours, and these mutations result in high levels of p53 protein in the tumour cells. Since the expression levels of wild-type p53 in nonmalignant tissue are usually much lower in contrast, the p53 protein is an attractive target for cancer immunotherapy. We tested p53 encoded HLA-A24 binding peptides for their capacity to elicit anti-tumour cytotoxic T lymphocytes (CTL) in vitro. These peptides were in murine p53-derived cytotoxic peptides, which were being presented to CTL by H-2K d and H-2K b molecules, because the HLA-A24 peptide binding motifs were similar to the H-2K d and H-2K b. For CTL induction, we used CD8+T lymphocytes from the peripheral blood mononuclear cells (PBMC) of healthy donors and the peptides from pulsed dendritic cells as antigen-presenting cells. We identified the peptide, p53-161 (AIYKQSQHM), which was capable of eliciting CTL lines that lysed tumour cells expressing HLA-A24 and p53. The effectors lysed C1RA24 cells (p53+, HLA-A*2402 transfectant), but not their parental cell lines C1R (p53+, HLA-A,B null cell). These results strongly indicate that the CTL exerts cytotoxic activity in HLA-A24's restricted manner. The identification of this novel p53 epitope for CTL offers the possibility to design and develop specific immunotherapeutic approaches for treating tumours with p53 mutation in HLA-A24-positive patients. © 2001 Cancer Research Campaign http://www.bjcancer.co

Fracture of a biopolymer gel as a viscoplastic disentanglement process

We present an extensive experimental study of mode-I, steady, slow crack dynamics in gelatin gels. Taking advantage of the sensitivity of the elastic stiffness to gel composition and history we confirm and extend the model for fracture of physical hydrogels which we proposed in a previous paper (Nature Materials, doi:10.1038/nmat1666 (2006)), which attributes decohesion to the viscoplastic pull-out of the network-constituting chains. So, we propose that, in contrast with chemically cross-linked ones, reversible gels fracture without chain scission

Kinetics of water flow through polymer gel

The water flow through the poly(acrylamide) gel under a constant water pressure is measured by newly designed apparatus. The time evolution of the water flow in the gel, is calculated based on the collective diffusion model of the polymer network coupled with the friction between the polymer network and the water. The friction coefficient are determined from the equilibrium velocity of water flow. The Young modulus and the Poisson's ratio of the rod shape gels are measured by the uni-axial elongation experiments, which determine the longitudinal modulus independently from the water flow experiments. With the values of the longitudinal modulus and of the friction determined by the experiments, the calculated results are compared with the time evolution of the flow experiments. We find that the time evolution of the water flow is well described by a single characteristic relaxation time predicted by the collective diffusion model coupled with the water friction.Comment: 7 pages, 5 figures, 27 references, Eqs adde

Adenosquamous carcinoma of the pancreas: a case report

Adenosquamous carcinoma of the pancreas is a rare variant of pancreatic exocrine carcinoma. We report a case of 70 year old man who came to our hospital with abdominal pain, anorexia and jaundice. Imaging of the abdomen showed a mass in the region of the head of the pancreas. Histological evaluation of the pancreatic tumor showed an adenosquamous carcinoma which was extensively infiltrative with perineural invasion, involvement of peripancreatic lymph nodes and all the thickness of the duodenum wall. The tumor exhibited a biphasic malignant growth identified as well to moderate differentiated adenocarcinoma and well to poorly differentiated squamous cell carcinoma

Outcomes and Risk Score for Distal Pancreatectomy with Celiac Axis Resection (DP-CAR): An International Multicenter Analysis

Background: Distal pancreatectomy with celiac axis resection (DP-CAR) is a treatment option for selected patients with pancreatic cancer involving the celiac axis. A recent multicenter European study reported a 90-day mortality rate of 16%, highlighting the importance of patient selection. The authors constructed a risk score to predict 90-day mortality and assessed oncologic outcomes. Methods: This multicenter retrospective cohort study investigated patients undergoing DP-CAR at 20 European centers from 12 countries (model design 2000–2016) and three very-high-volume international centers in the United States and Japan (model validation 2004–2017). The area under receiver operator curve (AUC) and calibration plots were used for validation of the 90-day mortality risk model. Secondary outcomes included resection margin status, adjuvant therapy, and survival. Results: For 191 DP-CAR patients, the 90-day mortality rate was 5.5% (95 confidence interval [CI], 2.2–11%) at 5 high-volume (≥ 1 DP-CAR/year) and 18% (95 CI, 9–30%) at 18 low-volume DP-CAR centers (P = 0.015). A risk score with age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) score, multivisceral resection, open versus minimally invasive surgery, and low- versus high-volume center performed well in both the design and validation cohorts (AUC, 0.79 vs 0.74; P = 0.642). For 174 patients with pancreatic ductal adenocarcinoma, the R0 resection rate was 60%, neoadjuvant and adjuvant therapies were applied for respectively 69% and 67% of the patients, and the median overall survival period was 19 months (95 CI, 15–25 months). Conclusions: When performed for selected patients at high-volume centers, DP-CAR is associated with acceptable 90-day mortality and overall survival. The authors propose a 90-day mortality risk score to improve patient selection and outcomes, with DP-CAR volume as the dominant predictor