Tensor renormalization group for fermions.

We review the basic ideas of the tensor renormalization group method and show how they can be applied for lattice field theory models involving relativistic fermions and Grassmann variables in arbitrary dimensions. We discuss recent progress for entanglement filtering, loop optimization, bond-weighting techniques and matrix product decompositions for Grassmann tensor networks. The new methods are tested with two-dimensional Wilson-Majorana fermions and multi-flavor Gross-Neveu models. We show that the methods can also be applied to the fermionic Hubbard model in 1+1 and 2+1 dimensions.

White globe appearance is an endoscopic predictive factor for synchronous multiple gastric cancer.

BACKGROUND: White globe appearance (WGA) is a small white lesion with a globular shape identified during magnifying endoscopy with narrow-band imaging. However, the association between WGA and synchronous multiple gastric cancer (SMGC) remains unclear. METHODS: Consecutive patients who underwent endoscopic submucosal dissection for gastric cancer (GC) between July 2013 and April 2015 at our institution were eligible for this study. We excluded patients with a history of gastric tumor or gastrectomy. Patients who had more than 2 GCs in their postoperative pathological evaluation were classified as SMGC-positive, and patients who had at least 1 WGA-positive GC were classified as WGA-positive patients. The primary outcome was a comparison of the prevalence of WGA in patients classified as SMGC-positive and SMGC-negative. Univariate and multivariate analyses were performed using the following variables: WGA, age, sex, atrophy, and Helicobacter pylori (H. pylori) status. RESULTS: There were 26 and 181 patients classified as SMGC-positive and SMGC-negative, respectively. Univariate analysis revealed that WGA-positive classification (50% vs. 23%, P=0.008) and male sex (88% vs. 66%, P=0.02) were significant factors associated with SMGC classification, while age ≥65 years (81% vs. 81%, P>0.99), severe atrophy (46% vs. 46%, P>0.99), and H. pylori positivity (69% vs. 65%, P=0.8) were not. In the multivariate analysis, only WGA-positive classification (odds ratio 2.78, 95% confidence interval 1.16-6.67; P=0.02) was a significant independent risk factor for SMGC. CONCLUSIONS: Our exploratory study showed the possibility of WGA as a predictive factor for SMGC. In cases of WGA-positive gastric cancer, careful examination might be needed to diagnose SMGC.

Oral vitamin C supplementation in hemodialysis patients and its effect on the plasma level of oxidized ascorbic acid and Cu/Zn superoxide dismutase, an oxidative stress marker.

BACKGROUND/AIM: Oxidative stress is known to be enhanced in hemodialysis patients, and one of its useful markers is plasma copper/zinc superoxide dismutase (Cu/Zn-SOD). The increase in plasma Cu/Zn-SOD can be inhibited by orally administered lipid-soluble vitamin E. We examined the antioxidative effects of water-soluble vitamin C administered orally on Cu/Zn-SOD levels in hemodialysis patients. METHODS: Vitamin C was orally administered to 16 maintenance hemodialysis patients before each dialysis session. Doses were increased from 200 to 1,000 mg over 3 months. The levels of plasma vitamin C and Cu/Zn-SOD and its mRNA expression in leukocytes were determined 1, 2, and 3 months after the start of vitamin C administration. Furthermore, the levels of oxidized and reduced forms of plasma vitamin C were determined before the start of vitamin C administration and before and after dialysis at 1,000-mg vitamin C doses. RESULTS: Following oral administration, the plasma levels of vitamin C and its oxidized form were increased. However, significant changes in plasma Cu/Zn-SOD or its mRNA expression in leukocytes were not observed. CONCLUSION: In maintenance hemodialysis patients, vitamin C administration resulted in a significant increase in the postdialysis level of the oxidized form of vitamin C, which suggested an increase in antioxidant effect. However, water-soluble vitamin C did not significantly suppress Cu/Zn-SOD expression enhancement.

Pharmacodynamic study of the Saltz regimen for metastatic colorectal cancer in a hemodialyzed patient.

OBJECTIVE: Combination therapy with irinotecan (CPT-11), 5-fluorouracil (5-FU) and leucovorin is widely used for the treatment of metastatic colorectal cancer. However, little is known about the safety of chemotherapy of malignancies in hemodialysis (HD) patients. We encountered a patient with colorectal carcinoma on HD. We decided to administer combination chemotherapy while monitoring the pharmacodynamics of the patient. CASE REPORT: A 74-year-old male received regular HD 3 times a week because of type 1 diabetes mellitus. He was diagnosed with stage IV colorectal cancer in November 2004. After sigmoidectomy, the patient received chemotherapy: a weekly schedule of CPT-11 (50 mg/m(2)) was administered followed by l-leucovorin (10 mg/m(2)) and 5-FU (400 mg/m(2)) just after HD. During the course, the plasma concentrations of both SN-38, an active metabolite of CPT-11, and 5-FU were not increased compared with those of patients with normal renal function. Our patient presented with grade III hematological toxicity that was easily recovered by granulocyte colony-stimulating factor. CONCLUSION: These data suggest that the dose-reduced Saltz regimen can be feasible for colorectal cancer patients receiving dialysis as postoperative adjuvant chemotherapy.

Comparison of effect of vitamin E-coated dialyzer and oral vitamin E on hemodialysis-induced Cu/Zn-superoxide dismutase.

BACKGROUND: We reported earlier that production of Cu/Zn-superoxide dismutase (SOD) increases markedly in hemodialysis patients but not in non-dialyzed chronic renal failure (CRF) patients. In this study, we compared the antioxidant effects of oral vitamin E supplementation (VE-PO) and vitamin E coating of a dialyzer (VE-BMD) by measuring increased Cu/Zn-SOD in hemodialysis patients. METHODS: 31 hemodialysis patients were divided into two groups: 16 hemodialysis patients underwent usual dialysis with vitamin E supplementation 600 mg/day while 15 others were dialyzed using vitamin E-coated membrane for 6 months. Total plasma SOD activity was determined by NBT method, plasma Cu/Zn-SOD contents by ELISA and Cu/Zn-SOD mRNA in leukocytes by RT-PCR. RESULTS: VE-PO and VE-BMD showed almost comparable effects on Cu/Zn-SOD contents and its mRNA levels in hemodialysis patients. VE-PO resulted in a progressive decrease of Cu/Zn-SOD content (p < 0.001). A comparable progressive decrease was observed also in VE-BMD (p < 0.0001). Both VE-PO and VE-BMD resulted in a progressive decrease of Cu/Zn-SOD mRNA (p < 0.01), which reached the level of non-dialyzed CRF patients.

mRNA study on Cu/Zn superoxide dismutase induction by hemodialysis treatment.

BACKGROUND/AIMS: There is little or no controversy about the increased oxidative stress of hemodialysis (HD) patients. Several reports show that the activity of superoxide dismutase (SOD), one of the major endogenous antioxidant enzymes, in plasma is elevated among HD patients. It is still unclear, however, whether this elevation is due to the promotion of SOD production or a decrease in renal excretion of SOD. This study was designed to investigate the cause of the SOD activation in HD patients, and we examined the expression of SOD mRNA levels in leukocytes of patients with chronic renal failure. METHODS: The total plasma SOD activity was determined by the nitroblue tetrazolium method, plasma SOD contents by ELISA, and SOD mRNA levels in leukocytes by RT-PCR. RESULTS: Our results demonstrated that contents and mRNA levels of Cu/Zn SOD in HD patients are 4.4 times and 2.0 times, respectively, as large as those in healthy controls. Furthermore, in contrast to nondialyzed chronic renal failure patients, we observed higher concentrations of Cu/Zn SOD in plasma and a more enhanced mRNA expression of Cu/Zn SOD in leukocytes of HD patients. CONCLUSION: Increased Cu/Zn SOD mRNA reflects enhanced antioxidant capacity of leukocytes and can be a promising oxidative stress marker in HD patients.

Evaluation of superoxide dismutase activity in dialyzed patients by electron spin resonance spectroscopy.

BACKGROUND: The relationship between plasma SOD activity and remaining renal function in patients with renal insufficiency has been not elucidated. We attempted to investigate the degree of serum SOD activity among patients with various renal conditions. METHODS: Using electron spin resonance (ESR) spectroscopy, plasma SOD activities were evaluated in 28 patients who underwent HD before and after procedure and in 15 controls. The patients were classified according to the condition of renal function; group A (n = 15) included patients whose plasma creatinine clearance levels were less than 10 ml/min, and group B (n = 13) included those whose plasma creatinine clearance levels were 10 ml/min or more but less than 20 ml/min. RESULTS: The plasma SOD activities of group A were significantly higher than those of group B (p < 0.005) and controls (p < 0.001). Multivariate analysis showed that in group A, the SOD activities in plasma before HD were significantly higher than those after HD (p < 0.001). However, in group B, there were no significant differences in the level of plasma SOD activities before and after HD. CONCLUSION: Production of superoxide anion is considered almost the similar in both groups, which suggests the SOD activity would depend on the degree of the remaining renal function of each patient.