S-1 and oxaliplatin versus tegafur-uracil and leucovorin as post-operative adjuvant chemotherapy in patients with high-risk stage III colon cancer: updated 5-year survival of the phase III ACTS-CC 02 trial.

BACKGROUND: The ACTS-CC 02 trial demonstrated that S-1 plus oxaliplatin (SOX) was not superior to tegafur-uracil and leucovorin (UFT/LV) in terms of disease-free survival (DFS) as adjuvant chemotherapy for high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries). We now report the final overall survival (OS) and subgroup analysis according to the pathological stage (TNM 7th edition) for treatment efficacy. PATIENTS AND METHODS: Patients who underwent curative resection for pathologically confirmed high-risk stage III colon cancer were randomly assigned to receive either UFT/LV (300 mg/m2 of UFT and 75 mg/day of LV on days 1-28, every 35 days, five cycles) or SOX (100 mg/m2 of oxaliplatin on day 1 and 80 mg/m2/day of S-1 on days 1-14, every 21 days, eight cycles). The primary endpoint was DFS and the patients' data were updated in February 2020. RESULTS: A total of 478 patients in the UFT/LV group and 477 patients in the SOX group were included in the final analysis. With a median follow-up time of 74.3 months, the 5-year DFS rate was 55.2% in the UFT/LV group and 58.1% in the SOX group [stratified hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.76-1.11; P = 0.3973], and the 5-year OS rates were 78.3% and 79.1%, respectively (stratified HR 0.97; 95% CI 0.76-1.24; P = 0.8175). In the subgroup analysis, the 5-year OS rates in patients with T4N2b disease were 51.0% and 64.1% in the UFT/LV and SOX groups, respectively (HR 0.72; 95% CI 0.40-1.31). CONCLUSION: Our final analysis reconfirmed that SOX as adjuvant chemotherapy is not superior to UFT/LV in terms of DFS in patients with high-risk stage III colon cancer. The 5-year OS rate was similar in the UFT/LV and SOX groups.

Surgery versus stereotactic body radiotherapy for clinical stage I non-small-cell lung cancer: propensity score-matching analysis including the ratio of ground glass nodules.

PURPOSE: To investigate whether surgery and stereotactic body radiotherapy (SBRT) yield comparable outcomes for clinical stage (c-stage) I non-small-cell lung cancer (NSCLC), propensity score-matching (PSM) analysis was conducted. METHODS: This single-institutional retrospective study included patients who underwent surgery (n = 574) or SBRT (n = 182) between 2004 and 2014. PSM was performed based on tumor diameter, age, sex, performance status, forced expiratory volume, Charlson comorbidity index, and ground glass nodules (GGN) defined as cTis or cT1mi according to the 8th TNM classification. RESULTS: The median follow-up durations for the surgery and SBRT groups were 66 and 69 months, respectively. The multivariate analysis revealed that non-GGN was a significant factor for poorer overall survival (OS) and disease-free survival (DFS): hazard ratio (HR) 19.95% confidence interval (CI) 4.7-79, P < 0.001; and HR 28, 95% CI 6.9-110, P < 0.001, respectively. PSM identified 120 patients from each group. The 5-year OS and DFS rates of the surgery vs SBRT groups were 71% (95% CI 61-79) vs 64% (95% CI 54-72) (P = 0.41) and 63% (95% CI 53-72) vs 55% (95% CI 45-63) (P = 0.23) after PSM, respectively. CONCLUSION: The PSM analyses including the ratio of GGN demonstrated that the OS and DFS for patients with c-stage I NSCLC in the surgery group were slightly superior to those for those in the SBRT group, although both survivals were not significantly different between the two therapeutic approaches.

Colorectal cancer treated by resection and extended lymphadenectomy: patterns of spread in left- and right-sided tumours.

BACKGROUND: Whether tumour side affects the anatomical extent and distribution of lymph node metastasis in colon cancer is unknown. The impact of tumour side on the anatomical pattern of lymphatic spread in colon cancer was assessed. METHODS: Patients with stage III colon cancer from a Japanese multi-institutional database who underwent extensive (D3) lymphadenectomy, which is similar in concept to complete mesocolic excision with central venous ligation, were divided into groups with right- and left-sided tumours. Based on location, mesenteric lymph nodes were categorized as paracolic (L1), intermediate (L2) or central (L3). The Kaplan-Meier method was used to evaluate disease-free survival (DFS) and overall survival (OS), and multivariable Cox models were used to evaluate the association between anatomical lymph node level, metastatic pattern and outcome. RESULTS: A total of 4034 patients with stage III colon cancer (right 1618, left 2416) were included. Unadjusted OS was worse in patients with right colon cancer (hazard ratio 1·23, 95 per cent c.i. 1·08 to 1·40; P = 0·002), but DFS was similar. Right-sided tumours more frequently invaded L3 nodes than left-sided lesions (8·5 versus 3·7 per cent; P < 0·001). The proportion of patients with a skipped pattern of lymphatic spread was higher in right than in left colon cancer (13·7 versus 9·0 per cent; P < 0·001). In multivariable analysis, invasion of L3 nodes was associated with worse OS in left but not in right colon cancer. The presence of skipped metastasis was associated with worse DFS in left, but not right, colon cancer. CONCLUSION: There are significant differences in the pattern of lymph node invasion between right- and left-sided stage III colon cancer, and in their prognostic significance, suggesting that tumour side may dictate the operative approach.

ANTECEDENTES: Se desconoce si la lateralidad del tumor influye en la extensión anatómica y en la distribución de las metástasis en los ganglios linfáticos (lymph node metastasis, LN) en el cáncer de colon. Se evaluó el impacto de la lateralidad del tumor en el patrón anatómico de diseminación linfática en el cáncer de colon. MÉTODOS: Los pacientes con cáncer de colon en estadio III recogidos en una base de datos japonesa multicéntrica, que se sometieron a una linfadenectomía ampliada (D3), conceptualmente similar a la escisión completa del mesocolon con ligadura venosa central, se dividieron en cáncer de colon del lado derecho y cáncer de colon del lado izquierdo. Según la ubicación, las LN mesentéricas se clasificaron como paracólicas (L1), intermedias (L2) o centrales (L3). Se utilizó el método de Kaplan-Meier para evaluar la supervivencia libre de enfermedad (disease-free survival, DFS) y la supervivencia global (overall-survival, OS), y se utilizaron modelos de Cox multivariados para evaluar la asociación entre el nivel L y el patrón metastásico con el resultado. RESULTADOS: Se incluyeron 4.034 pacientes con cáncer de colon en estadio III (cáncer de colon derecho: n = 1.618, cáncer de colon izquierdo: n = 2.416). La OS no ajustada fue peor en el cáncer de colon derecho (cociente de riesgos instantáneos, hazard ratio, HR 1,23, i.c. del 95%: 1,08-1,4; P = 0,002), pero la DFS fue similar. La afectación de los ganglios L3 fue más frecuente en pacientes con cáncer de colon derecho que izquierdo (8,5% versus 3,7%, P < 0,001). En el cáncer de colon derecho, la proporción de pacientes con patrón de diseminación linfática discontinuo, con salto entre niveles, fue mayor en comparación con el cáncer de colon izquierdo (13,7% versus 9%; P < 0,001). En el análisis multivariante, la invasión de los ganglios L3 se asoció con una peor OS en el cáncer de colon izquierdo, pero no en el cáncer de colon derecho. La presencia de metástasis discontinuas se asoció con una peor DFS en el cáncer de colon izquierdo, pero no en el cáncer de colon derecho. CONCLUSIÓN: Existen diferencias significativas en el patrón de invasión de los LN entre el cáncer de colon derecho e izquierdo en estadio III, así como en su importancia pronóstica, lo que sugiere que la lateralidad del tumor puede determinar el abordaje quirúrgico.

Bendamustine-120 plus rituximab therapy for relapsed or refractory follicular lymphoma: a multicenter phase II study.

The optimal dose, schedule, and other aspects of bendamustine plus rituximab treatment remain unclear for patients with relapsed or refractory follicular lymphoma (FL). Herein, we analyzed the efficacy of bendamustine combined with rituximab (RB-120) treatment for Japanese patients with relapsed or refractory FL. This phase II clinical trial included patients with relapsed or refractory FL who received 375 mg/m2 rituximab on day 1 and 120 mg/m2 bendamustine on days 2 and 3 every 28 days for up to 6 cycles. The primary endpoint was the overall response rate (ORR), and the secondary endpoints included the complete response (CR) rate, progression-free survival (PFS), overall survival (OS), and safety. Thirty-seven patients were enrolled in the trial (median age 62 years, range 42-75 years). All patients were previously treated with rituximab-containing chemotherapy, and 83.8% were previously treated with the R-CHOP regimen. A median of 5 cycles (range 1-6) and 48.6% of patients completed 6 cycles. The ORR was 91.9% (95% confidence interval [CI] 78.1-98.3%), with a CR rate of 86.5% (95% CI 71.2-95.5%). The 3-year PFS and OS were 70.9% (95% CI 52.3-83.3%) and 88.9% (95% CI 73.1-95.7%), respectively, with the median 39.5 months follow-up duration. The most-frequently observed grade 3/4 adverse events were hematologic: lymphopenia (95%) and neutropenia (70%). No treatment-related deaths were observed. RB-120 showed a good efficacy with equivalent toxicities, compared with the bendamustine 120 mg/m2 monotherapy. However, the problem of high drop-out incidences cannot be ignored.

Tau imaging with [18 F]THK-5351 in progressive supranuclear palsy.

BACKGROUND AND PURPOSE: Visualization of pathogenic protein aggregates is crucial to elucidate pathomechanisms and to make an accurate diagnosis in many neurodegenerative conditions. Aggregates of the microtubule-binding protein, tau, are one of the most important pathogenic molecules in neurodegenerative disorders. Progressive supranuclear palsy (PSP) is characterized by the deposition of tau proteins in some specific area such as the basal ganglia and brainstem. We tried to detect tau lesions in the brains of living patients with PSP with a novel positron emission tomography (PET) tracer, [18 F]THK-5351, which we have recently developed. METHODS: Paraffin-embedded brain sections of the patients with PSP were used for autoradiography with [3 H]THK-5351 and immunohistochemistry. Nine healthy controls, 13 patients with Alzheimer's disease and three patients with PSP participated in this PET study with [18 F]THK-5351. To detect amyloid-ß deposition, PET imaging with Pittsburgh compound B was also performed. RESULTS: Autoradiography in the brain sections of patients with PSP demonstrated [3 H]THK-5351 binding to tau deposits with a high selectivity. Although patients with PSP exhibited no remarkable [18 F]THK-5351 retention in the temporal cortex, significantly higher tracer retention was observed in the globus pallidus and midbrain. In contrast, amyloid imaging with Pittsburgh compound B showed no remarkable accumulation in the cerebral cortex of PSP. CONCLUSIONS: We conclude that [18 F]THK-5351 PET can potentially be used to detect the regional brain distribution of tau lesions in PSP, thereby facilitating the differential diagnosis of neurodegenerative disorders associated with tau protein.

Serum ferritin level is a prognostic marker in patients with peripheral T-cell lymphoma.

INTRODUCTION: The prognostic value of serum ferritin level in patients with peripheral T-cell lymphoma (PTCL) remains unknown. METHODS: We retrospectively analyzed clinical data from 78 consecutive patients with newly diagnosed PTCL that were treated with anthracycline-containing regimens between 1998 and 2011. RESULTS: The patients consisted of 50 males and 28 females with a median age of 64 years (range, 16-83 years). The subtypes of PTCL were 39 PTCL, not otherwise specified and 39 angioimmunoblastic T-cell lymphoma (AITL). The median observation period for the surviving patients was 50 months. The overall survival (OS) was poorer in patients with serum ferritin level above the upper normal limit (n = 28), compared with patients with serum ferritin level within normal range (n = 50; 4-year OS: 23% vs. 72%; P < 0.001). In the multivariate analysis, poor performance status (P = 0.006) and elevated serum ferritin level (P = 0.018) were independent risk factors for poor OS. CONCLUSION: Serum ferritin level is a useful prognostic marker for PTCL.

Favorable survival after allogeneic stem cell transplantation with reduced-intensity conditioning regimens for relapsed/refractory follicular lymphoma.

Allogeneic stem cell transplantation (allo-SCT) is a curative option for patients with relapsed follicular lymphoma (FL). Prospective studies of reduced-intensity conditioning (RIC) have revealed that chemosensitivity at allo-SCT is the most reliable predictor of outcome; however, limited data are available for progressive/refractory disease. We report here a retrospective analysis of RIC allo-SCT for patients with FL. The purpose of this study was to elucidate the role of allo-SCT for patients with relapsed/refractory FL. We analyzed 46 patients-11 (24%) transplanted in CR, 6 (13%) transplanted in PR and 29 (63%) with progressive/refractory disease. The estimated 5-year overall survival rate was 71.6% (95% confidence interval (CI), 51.5-84.5%). According to the disease status at transplantation, the 5-year survival rate was 80.7% (95% CI, 37.7-95.4%) in the patients with CR or PR and 66.1% (95% CI, 41.5-82.3%) in those with progressive/refractory disease (P=0.29). There were no differences in relapse/progression and non-relapse mortality between the patients with chemosensitive disease and progressive/refractory disease. Allo-SCT may be a valuable treatment option, even for patients with progressive/refractory FL.

Acute leukemia during pregnancy: an investigative survey of the past 11 years.

INTRODUCTION: The management of pregnant women with acute leukemia is usually challenging. We collected data concerning pregnant women with acute leukemia in the Kanagawa area in Japan. METHODS: A questionnaire was sent to 24 institutions in the Kanagawa area. RESULTS: Data were obtained for 11 patients, median age of 31 years (range, 20-36). Eight patients had acute myeloid leukemia and three had acute lymphoblastic leukemia. Six patients were diagnosed in the first trimester of pregnancy, one in the second trimester, and four in the third trimester. Five of six patients diagnosed in the first trimester had abortions before chemotherapy, and one had an elective abortion after receiving chemotherapy. All patients diagnosed in the second or third trimester delivered live infants. Of the six patients diagnosed in the first trimester, two died of recurrent leukemia, and four remained in remission. Of the five patients diagnosed in the second or third trimester, four achieved complete remission and remained in remission. One patient died of sepsis 4 days after cesarean section. CONCLUSIONS: Careful surveillance and monitoring of the fetus and close co-operation among hematologists, gynecologists, and pediatricians are essential to successfully treat pregnant women with acute leukemia.

S-1 as adjuvant chemotherapy for stage III colon cancer: a randomized phase III study (ACTS-CC trial).

BACKGROUND: S-1 is an oral fluoropyrimidine whose antitumor effects have been demonstrated in treating various gastrointestinal cancers, including metastatic colon cancer, when administered as monotherapy or in combination chemotherapy. We conducted a randomized phase III study investigating the efficacy of S-1 as adjuvant chemotherapy for colon cancer by evaluating its noninferiority to tegafur-uracil plus leucovorin (UFT/LV). PATIENTS AND METHODS: Patients aged 20-80 years with curatively resected stage III colon cancer were randomly assigned to receive S-1 (80-120 mg/day on days 1-28 every 42 days; four courses) or UFT/LV (UFT: 300-600 mg/day and LV: 75 mg/day on days 1-28 every 35 days; five courses). The primary end point was disease-free survival (DFS) at 3 years. RESULTS: A total of 1518 patients (758 and 760 in the S-1 and UFT/LV group, respectively) were included in the full analysis set. The 3-year DFS rate was 75.5% and 72.5% in the S-1 and UFT/LV group, respectively. The stratified hazard ratio for DFS in the S-1 group compared with the UFT/LV group was 0.85 (95% confidence interval: 0.70-1.03), demonstrating the noninferiority of S-1 (noninferiority stratified log-rank test, P < 0.001). In the subgroup analysis, no significant interactions were identified between the major baseline characteristics and the treatment groups. CONCLUSION: Adjuvant chemotherapy using S-1 for stage III colon cancer was confirmed to be noninferior in DFS compared with UFT/LV. S-1 could be a new treatment option as adjuvant chemotherapy for colon cancer. CLINICALTRIALSGOV: NCT00660894.

Value of pre- and postoperative meticillin-resistant Staphylococcus aureus screening in patients undergoing gastroenterological surgery.

BACKGROUND: Data supporting active surveillance of meticillin-resistant Staphylococcus aureus (MRSA) for the prevention of postoperative infection remain controversial. AIM: To investigate the efficacy of MRSA screening in patients undergoing gastroenterological surgery. METHOD: Nasal carriage of MRSA was screened using a polymerase chain reaction (PCR) assay on two gastroenterological surgery wards (A and B). Occurrence of postoperative MRSA infection was analysed according to nasal MRSA carriage status (pre-operative carriage and postoperative acquisition). FINDINGS: The incidence of pre-operative MRSA carriage was 9.7% on Ward A and 4.3% on Ward B (P = 0.009). Postoperative nasal MRSA acquisition was confirmed in 16.2% and 6.0% of patients, respectively (P < 0.001). There was no significant difference in the incidence of MRSA surgical site infections (SSIs) between patients with and without pre-operative nasal colonization on either ward. On Ward A, where MRSA nasal acquisition was more common, the MRSA infection rate in patients with postoperative nasal acquisition was 26.8%, which was significantly higher than the rates in patients with pre-operative MRSA colonization and patients without colonization during hospitalization. Postoperative nasal MRSA acquisition was an independent factor associated with MRSA infection on both wards [Ward A: odds ratio (OR) 7.192, 95% confidence interval (CI) 2.981-17.352; Ward B: OR 5.761, 95% CI 1.429-23.220]. CONCLUSION: MRSA SSIs were prevented by a screening-based strategy in pre-operative MRSA carriers. Postoperative nasal acquisition was a significant factor affecting MRSA infection, and the effect of screening varied according to the incidence of postoperative MRSA acquisition on the ward.

Utility of weekly docetaxel combined with preoperative radiotherapy for locally advanced esophageal cancer from pathological analysis.

Esophageal squamous cell cancer (ESCC) is a high-grade carcinoma that is treated with multidisciplinary approaches, including chemoradiotherapy (CRT) followed by surgery. Despite some success with these therapies, overall survival remains poor. In order to investigate a newer CRT regimen, we designed a comparative study to evaluate preoperative CRT using docetaxel (DOC) or 5-Fluorouracil and cisplatin (FU+CDDP [FP] therapy) for treatment of resectable ESCC. In a retrospective review of patients with resectable, locally advanced ESCC, 95 patients received preoperative CRT between 2001 and 2007. CRT was administered using either FP (n = 40) or DOC (n = 55). Pathological response and clinical outcomes were compared between the two groups. Hazard ratios and time-to-event analyses were used to assess outcomes; the ratios were controlled by multivariate logistic regression analysis of potential prognostic factors, and survival was presented with Kaplan-Meier curves. In the FP group, a significant curative effect was observed on the basis of pathological examination of postoperative lesions. However, the DOC group presented a significantly better prognosis on the basis of cumulative survival rates. Logistic regression analysis revealed that the presence of five or more lymph node metastases was an independent predictor of reduced survival. Patients with lymph node metastasis exhibited a better prognosis in the DOC group than those in the FP group. Preoperative CRT for locally advanced esophageal cancer using DOC results in similar or better long-term outcomes compared with FP-based CRT. Therefore, CRT using DOC is a promising therapy option for esophageal cancer.

Analysis of wear, wear particles, and reduced inflammatory potential of vitamin E ultrahigh-molecular-weight polyethylene for use in total joint replacement.

Vitamin E (VE) has been added to ultrahigh-molecular-weight polyethylene (UHMWPE) acetabular cups and tibial trays primarily to reduce oxidative damage to the polymer. The aim of this study was to investigate the relative wear rates of UHMWPE-containing VE compared with virgin UHMWPE. The ability of VE to reduce the amount of inflammatory cytokines produced from stimulated peripheral blood mononuclear cells (PBMNCs) was also investigated. Stimulation was achieved by exposure of PBMNCs to either lipoplysaccharide (LPS) or VE-containing UHMWPE (VE-UHMWPE). In the present study, results showed that the wear rates of UHMWPE with or without VE were not significantly different. Particles generated by UHMWPE with and without VE were not significantly different in size distribution. The production of osteolytic mediators, tumor necrosis factor-alpha, interleukin 1ß (IL-ß), IL-6, and IL-8 were significantly reduced in (PBMNCs) stimulated with either LPS + VE compared with LPS or VE-UHMWPE particles compared to virgin UHMWPE particles. This trend was also observed when VE was added as a liquid to UHMWPE wear particle-stimulated PBMNCs. The exact mechanism of how VE affects the release of inflammatory mediators from particle-stimulated macrophages is not yet understood. It is likely to involve the anti-inflammatory and/or antioxidant effects of VE.

Circulating tumor cells as a potential biomarker in selecting patients for pulmonary metastasectomy from colorectal cancer: report of a case.

Pulmonary metastasectomy is indicated for selected patients with metastatic colorectal cancer. A 43-year-old woman presented with solitary pulmonary metastasis from descending colon cancer and pulmonary metastasectomy was performed because of absence of any other active metastasis as well as normal serum carcinoembryonic antigen value. However, she died due to early development of nodal and bone metastases within 6 months after thoracotomy. The presence of circulating tumor cells (CTCs) in the peripheral blood (6 CTCs/7.5 ml) was the only factor to predict such a poor prognosis, suggesting that the CTC test is useful in selecting patients for pulmonary metastasectomy.

Safety of UFT/LV and S-1 as adjuvant therapy for stage III colon cancer in phase III trial: ACTS-CC trial.

BACKGROUND: The Adjuvant Chemotherapy Trial of TS-1 for Colon Cancer (ACTS-CC) is a phase III trial designed to validate the non-inferiority of S-1 to UFT/leucovorin (LV) as postoperative adjuvant chemotherapy for stage III colon cancer. We report the results of a planned safety analysis. METHODS: Patients aged 20-80 years with curatively resected stage III colon cancer were randomly assigned to receive UFT/LV (UFT, 300 mg m(-2) per day as tegafur; LV, 75 mg per day on days 1-28, every 35 days, 5 courses) or S-1 (80, 100, or 120 mg per day on days 1-28, every 42 days, 4 courses). Treatment status and safety were evaluated. RESULTS: Of 1535 enrolled patients, a total of 1504 (756 allocated to S-1 and 748 to UFT/LV) were analysed. The completion rate of protocol treatment was 77% in the S-1 group and 73% in the UFT/LV group. The overall incidence of adverse events (AEs) were 80% in S-1 and 74% in UFT/LV. Stomatitis, anorexia, hyperpigmentation, and haematological toxicities were common in S-1, whereas increased alanine aminotransferase and aspartate aminotransferase were common in UFT/LV. The incidences of grade 3 AEs were 16% and 14%, respectively. CONCLUSION: Although AE profiles differed between the groups, feasibility of the protocol treatment was good. Both S-1 and UFT/LV could be safely used as adjuvant chemotherapy.

Adiponectin in plasma and cerebrospinal fluid in MCI and Alzheimer's disease.

BACKGROUND AND PURPOSE: Life style-related disorders such as hypertension, diabetes, dyslipidemia, and obesity are reported to be a great risk of dementia. Adipocytokines released from adipose tissue are thought to modulate some brain functions including memory and cognition. We here analysed adiponectin, one of the most important adipocytokines, in plasma and cerebrospinal fluid (CSF) from cognitive normal controls (NC), mild cognitive impairment (MCI) subjects, and patients with Alzheimer's disease (AD) and discussed if/how adiponectin could relate to the pathogenesis of AD. METHODS: Normal controls (n = 28), MCI (n = 18), and AD (n = 27) subjects were recruited at Tohoku University Hospital. The diagnosis of AD was based on NINCDS-ADRDA criteria. All the blood and CSF samples were obtained from each fasted subject. Adiponectin was assayed using a sandwich ELISA system. RESULTS: The levels of adiponectin between in plasma and in CSF showed a positive correlation. Plasma adiponectin was significantly higher in MCI and AD compared to NC, whereas CSF adiponectin was significantly higher in MCI compared to NC. CONCLUSION: It is possible that the level of adiponectin in plasma reflects its level in CSF. The tendency to have higher adiponectin in plasma and CSF from MCI and AD suggests that this molecule plays a critical role in the onset of AD.

Effect of pH on anisotropic gelation of DNA induced by aluminum cations.

To investigate the effects of pH on the structure and the properties of DNA anisotropic gels and their growth process, we have observed the morphology of DNA anisotropic gel films prepared from DNA solutions with various initial pH, and measured the pH dependences of the shrinking ratio, the birefringence, and the relaxation modulus of the gel as well as the time courses of the gel front and pH-change front lines. The gel films prepared from DNA solutions with high pH have inhomogeneous macroscopic structure, large shrinking ratio, and high optical anisotropy whereas those prepared from DNA solutions with low pH have homogeneous macroscopic structure, small shrinking ratio, and low optical anisotropy. The difference observed at different pH is attributed to the difference in the interaction between DNA molecules and aluminum cations. The time courses of the gel front and pH-change front lines were analyzed with theories based on assumptions for each condition. Both two-stage dynamics observed under high initial pH and one-stage dynamics under low initial pH were explained consistently with the theories.