Quantifying the solid-fluid interfacial tensions depending on the substrate curvature: Young's equation holds for wetting around nanoscale cylinder.

By extending the theoretical framework derived in our previous study [Imaizumi et al., J. Chem. Phys. 153, 034701 (2020)], we successfully calculated the solid-liquid (SL) and solid-vapor (SV) interfacial tensions of a simple Lennard-Jones fluid around solid cylinders with nanometer-scale diameters from single equilibrium molecular dynamics systems in which a solid cylinder was vertically immersed into a liquid pool. The SL and SV interfacial tensions γSL - γS0 and γSV - γS0 relative to that for bare solid surface γS0, respectively, were obtained by simple force balance relations on fluid-containing control volumes set around the bottom and top ends of the solid cylinder, which are subject to the fluid stress and the force from the solid. The theoretical contact angle calculated by Young's equation using these interfacial tensions agreed well with the apparent contact angle estimated by the analytical solution to fit the meniscus shape, showing that Young's equation holds even for the menisci around solids with nanoscale curvature. We have also found that the curvature effect on the contact angle was surprisingly small while it was indeed large on the local forces exerted on the solid cylinder near the contact line. In addition, the present results showed that the curvature dependence of the SL and SV interfacial free energies, which are the interfacial tensions, is different from that of the corresponding interfacial potential energies.

Site-specific differences in survival among upper and lower tract urothelial carcinoma patients treated with radical surgery.

BACKGROUND: It currently remains unclear whether the location of primary tumours affects the clinical outcomes of patients with locally advanced urothelial carcinoma in the urinary tract. The aim of the present study was to compare prognostic differences between bladder urothelial carcinoma and upper tract urothelial carcinoma, particularly pT3 or higher tumours. METHODS: In total, 307 patients with pT3 or higher urothelial carcinoma without distant metastasis who underwent radical cystectomy for bladder urothelial carcinoma (N = 127, 41.4%) or radical nephroureterectomy for upper tract urothelial carcinoma (N = 180, 58.6%) at Keio University Hospital and three affiliated hospitals between 1994 and 2017 were enrolled. Oncological outcomes were compared between bladder urothelial carcinoma and upper tract urothelial carcinoma using Cox regression analysis. RESULTS: Significantly higher rates of male patients, smokers, neoadjuvant chemotherapy, lymph node involvement and lymphovascular invasion were observed in the bladder urothelial carcinoma group. The incidence of regional lymph node or local recurrence was higher in patients with bladder urothelial carcinoma than in those with upper tract urothelial carcinoma, while that of lung metastasis was lower. In all patients, bladder urothelial carcinoma was independently associated with disease recurrence (hazard ratio (HR) 1.504, P = 0.035) in addition to neoadjuvant chemotherapy and lymphovascular invasion. Bladder urothelial carcinoma was also independently associated with cancer death (HR = 1.998, P = 0.002) as well as lymphovascular invasion. Following the exclusion of patients who received neoadjuvant chemotherapy, bladder urothelial carcinoma remained an independent risk factor for disease recurrence and cancer death (HR = 1.702, P = 0.010 and HR = 1.888, P = 0.013, respectively). CONCLUSIONS: Bladder urothelial carcinoma may follow worse prognosis compared to upper tract urothelial carcinoma, particularly that with a high pathological stage.

Tetraalkoxyphenanthrene-Fused Thiadiazoloquinoxalines: Synthesis, Electronic, Optical, and Electrochemical Properties, and Self-Assembly.

π-Extended thiadiazoloquinoxaline (TQ) derivatives 1a,b-3a,b, in which a tetraalkoxyphenanthrene moiety is annulated with the TQ core and benzene rings are incorporated via the ethynylene spacer, were synthesized. They display absorption bands reaching into 750 nm and possess the electron-affinity comparable to [60]fullerene. The CF3- and OMe-substituents on the benzene rings have moderate effects on modulation of the HOMO and LUMO levels. Tetraalkoxyphenanthrene-fused TQs 1a,b-3a,b aggregate in the solid state and assemble in solution through π-π stacking interactions. The self-assembly of 1a,b-3a,b into 1D superstructures was confirmed, and the difference in the alkoxy groups and the solvents for self-assembly proved to change their morphology. Comparison of the properties of 1a and those of reference compounds 4 and 5 clarified the effects of both the fusion of the phenanthrene moiety and the introduction of ethynylene spacers on the properties.

Soybean DREB1/CBF-type transcription factors function in heat and drought as well as cold stress-responsive gene expression.

Soybean (Glycine max) is a globally important crop, and its growth and yield are severely reduced by abiotic stresses, such as drought, heat, and cold. The cis-acting element DRE (dehydration-responsive element)/CRT plays an important role in activating gene expression in response to these stresses. The Arabidopsis DREB1/CBF genes that encode DRE-binding proteins function as transcriptional activators in the cold stress responsive gene expression. In this study, we identified 14 DREB1-type transcription factors (GmDREB1s) from a soybean genome database. The expression of most GmDREB1 genes in soybean was strongly induced by a variety of abiotic stresses, such as cold, drought, high salt, and heat. The GmDREB1 proteins activated transcription via DREs (dehydration-responsive element) in Arabidopsis and soybean protoplasts. Transcriptome analyses using transgenic Arabidopsis plants overexpressing GmDREB1s indicated that many of the downstream genes are cold-inducible and overlap with those of Arabidopsis DREB1A. We then comprehensively analyzed the downstream genes of GmDREB1B;1, which is closely related to DREB1A, using a transient expression system in soybean protoplasts. The expression of numerous genes induced by various abiotic stresses were increased by overexpressing GmDREB1B;1 in soybean, and DREs were the most conserved element in the promoters of these genes. The downstream genes of GmDREB1B;1 included numerous soybean-specific stress-inducible genes that encode an ABA receptor family protein, GmPYL21, and translation-related genes, such as ribosomal proteins. We confirmed that GmDREB1B;1 directly activates GmPYL21 expression and enhances ABRE-mediated gene expression in an ABA-independent manner. These results suggest that GmDREB1 proteins activate the expression of numerous soybean-specific stress-responsive genes under diverse abiotic stress conditions.

Environmental Transmission Electron Microscopy Study of Diesel Carbon Soot Combustion under Simulated Catalytic-Reaction Conditions.

Environmental transmission electron microscopy (ETEM) is used to monitor the catalytic combustion of diesel carbon soot upon exposure to molecular oxygen at elevated temperatures by using a gas-injection specimen heating holder. The reaction conditions simulated in the ETEM experiments reconstruct real conditions effectively. This study demonstrated for the first time that soot combustion occurs at the soot-catalyst interface for both Ag/CeO2 and Cu/BaO/La2 O3 catalysts.

Locally recurrent prostate cancer with RB1/TP53 alterations successfully treated by salvage focal brachytherapy: a case report.

Retinoblastoma transcriptional corepressor 1 (RB1) and tumor protein p53 (TP53) are well-known tumor suppressor genes; their alterations are associated with poor prognosis in human malignancies and quite rare in locally recurrent cases. The patient was a 58-year-old man who was diagnosed with cT1cN0M0 prostate cancer with Gleason score of 3+3=6 and underwent brachytherapy as the initial treatment. Local recurrence was detected in the left lobe of the prostate 154 months later and whole-exome sequencing that was performed at the request of the patient revealed RB1 loss-of-heterozygosity and TP53 p.I162Rfs*27 mutations. He underwent salvage focal brachytherapy with 125I seeds and serum prostate-specific antigen levels has been stabilized without any genitourinary or gastrointestinal toxicity.

Salvage focal brachytherapy in castration-resistant prostate cancer with neuroendocrine differentiation after radiation therapy.

Introduction: Treatment strategy for castration-resistant prostate cancer with neuroendocrine differentiation after radiation therapy has not been established. Case presentation: We described a case of castration-resistant prostate cancer with neuroendocrine differentiation after initial external beam radiotherapy followed by salvage androgen deprivation therapy. Magnetic resonance imaging detected recurrence of a suspicious lesion in the left lobe of the prostate, although the prostate-specific antigen level was <0.2 ng/mL. Transperineal prostate saturation needle biopsy detected adenocarcinoma with neuroendocrine differentiation. The patient underwent salvage focal brachytherapy and had a prostate-specific antigen progression-free survival of 20 months with no obvious adverse events. No recurrence has been detected on magnetic resonance imaging for 18 months. Conclusion: Salvage focal brachytherapy for prostate cancer after external beam radiotherapy can be one of the treatment strategies for local recurrence of castration-resistant prostate cancer with neuroendocrine differentiation.

Utility of prophylactic antibiotics for preventing febrile neutropenia during cabazitaxel therapy for castration-resistant prostate cancer.

The aim was to investigate the efficacy of prophylactic antibiotics for the prevention of febrile neutropenia (FN) during cabazitaxel therapy for castration-resistant prostate cancer (CRPC) with G-CSF. We retrospectively studied 443 cycles of cabazitaxel therapy given to 56 patients with CRPC at Keio University Hospital between May 2012 and August 2018. Statistical analysis was conducted to determine whether the combination of prophylactic G-CSF and antibiotics was more effective in preventing FN, compared with prophylactic G-CSF alone. Prophylactic PEG-G-CSF or G-CSF was administered in all 443 cycles. Only fluoroquinolones were used as prophylactic antibiotics and were administered in 328 cycles (74.0%). FN occurred in 5 cycles (1.1%). Prophylactic antibiotics were administered in 327 cycles (74.6%) in the FN-negative group and in only 1 cycle (20.0%) in the FN-positive group. Chi-square test indicated the incidence of FN was significantly lower in the group that received prophylactic antibiotics compared with the group that did not receive prophylactic antibiotics (P = 0.017). Compared with prophylactic G-CSF alone, prophylactic G-CSF and antibiotics significantly suppressed the occurrence of FN.

Recurrent hepatogastric fistula during lenvatinib therapy for advanced hepatocellular carcinoma managed by over-the-scope clip closure: a case report.

Objective: Lenvatinib is an oral multitarget tyrosine kinase inhibitor (mTKI) and is recommended for patients with advanced hepatocellular carcinoma (HCC) with Child-Pugh A liver function, who are not amenable to surgical resection, locoregional treatment, or transcatheter arterial chemoembolization. Hepatogastric fistula is a rare complication with a poor prognosis in patients with HCC. Previous reports on fistula formation during mTKI therapy for HCC were all associated with sorafenib. Here, we report the first case of recurrent hepatogastric fistula during lenvatinib therapy for advanced HCC managed using an over-the-scope clip (OTSC). Patient: We present the case of a 73-year-old man with alcoholic liver cirrhosis who was treated for multiple HCC for 7 years. HCC was treated using repetitive transcatheter arterial chemoembolization, radiofrequency ablation, and sorafenib. Owing to disease progression, lenvatinib treatment was started. During lenvatinib treatment, recurrent hepatogastric fistulas developed. An OTSC was useful for fistula closure and prevention of recurrence. Results: The major cause of fistula formation is considered to be the direct invasion of HCC; however, HCC treatment might also be a contributing factor in our case. In addition, OTSC was useful for fistula closure. Conclusion: Clinicians should be aware of the fatal complications during HCC treatment.

A case in which bladder cancer invaded the ureteral orifice and was resected via photodynamic diagnosis-assisted transurethral resection involving orally administered 5-aminolevulinic acid.

INTRODUCTION: Transurethral resection of bladder tumor is widely used in combination with photodynamic diagnosis to treat non-muscle invasive bladder cancer. We experienced an intriguing case, in which bladder cancer infiltrated into the right ureteral orifice and was resected via photodynamic diagnosis-assisted transurethral resection involving the oral administration of 5-aminolevulinic acid. CASE PRESENTATION: This case was a 71-year-old Japanese man. He was diagnosed with bladder carcinoma, which had infiltrated into the right ureter (clinical classification: T1, N0, M0). He underwent transurethral resection involving the oral administration of 5-aminolevulinic acid. We successfully resected the tumor in the ureteral orifice, which was accomplished by resecting the ureteral orifice until the non-luminescent lumen was exposed. After the surgery, to prevent recurrence, Bacillus Calmette-Guérin was administered intravesically after right ureteral stent placement. CONCLUSION: Photodynamic diagnosis-assisted transurethral resection involving the oral administration of 5-aminolevulinic acid has the potential to treat ureteral tumors derived from bladder tumors.

Abscess formation of the round ligament of the liver: report of a case.

Abscess formation of the round ligament of the liver is very rare. We report a case of a 70-year-old female with abscess of the round ligament after an endoscopic papillotomy for choledocholithiasis. On the 21st day following papillotomy, abscess formation of the round ligament was found by ultrasonographic examination. Surgical treatment was performed because conservative therapy was not effective. The purulent fluid and necrotic tissue at the round ligament were completely removed. Cultures obtained from the abscess grew Staphylococcus epidermidis, but the mechanism of abscess formation in this case remains unclear.

No significant impact of patient age and prior treatment profile with docetaxel on the efficacy of cabazitaxel in patient with castration-resistant prostate cancer.

BACKGROUND: The correlation of the oncological outcomes of docetaxel and cabazitaxel in Japanese metastatic castration-resistant prostate cancer (mCRPC) patients has not been unclear. MATERIALS AND METHODS: This study included a total of 47 consecutive Japanese mCRPC patients treated with cabazitaxel and assessed the prognostic significance of cabazitaxel, focusing on patient age and the correlation of efficacy between docetaxel and cabazitaxel. RESULTS: Prostate-specific antigen (PSA) decline was observed in 27 patients (57.4%), including 19 (40.0%) achieving the response defined by PSA decline ≥ 30%. The median overall survival (OS) periods after the introduction of cabazitaxel was 16.1 months. Twenty (42.6%) were judged to have responded to cabazitaxel with a PSA decrease ≥ 30% from the baseline. A 30% PSA response to cabazitaxel was achieved in 4 (50.0%) patients with ≧ 75 years (n = 8) and 16 (41.0%) patients with less than 75 years (n = 39). There was no significant correlation between the PSA response and patients' age (p = 0.707). A 30% PSA response to cabazitaxel was achieved in 13 (46.4%) and 7 (36.8%) patients with and without that to docetaxel, respectively. A 30% PSA response to cabazitaxel was achieved in 5 (16.6%) and 7 (41.2%) patients who had treated with less than 10 cycles docetaxel or 10 â‰¦ cycles, respectively. Univariate and multivariate analyses revealed that there were no significant correlation of patient age (p = 0.537), the response to prior docetaxel therapy (p = 0.339) or cycles of docetaxel therapy (p = 0.379) with shorter OS. CONCLUSION: These results indicate that the introduction of cabazitaxel for Japanese mCRPC patients could result in oncological outcomes without any association with patient's age and the profiles of previous docetaxel therapy.

[ACUTE SCROTUM IN THE PEDIATRIC EMERGENCY ROOM: A SINGLE CENTER RETROSPECTIVE STUDY].

(Objective) The objective of this study was to survey cases of acute scrotum examined at the pediatric emergency room (ER). (Subjects and methods) All patients examined for acute scrotum at the emergency outpatient unit between March 2010 and March 2014 were designated subjects of the study. Medical records were used to retrospectively investigate the final diagnoses including testicular torsion (TT), torsion of the testicular appendage, epididymitis, orchitis, incarcerated inguinal hernia, idiopathic scrotal edema, Schönlein-Henoch purpura, hydrocele, external trauma, as well as those with no confirmed diagnosis. (Results) A total of 257 patients presented with acute scrotum at the emergency outpatient unit. The patients had an average age of 6.7 years, with symptoms present on the right side in 120 cases (47%), left side in 108 cases (42%), and both sides in 29 cases (11%). Observing the frequency of each condition, TT was present in 33 cases (13%), torsion of the testicular appendage in eight cases (3%), epididymitis in 85 cases (33%), orchitis in four cases (2%), incarcerated inguinal hernia in 59 cases (23%), idiopathic scrotal edema in six cases (2%), Schönlein-Henoch purpura in nine cases (4%), hydrocele in 10 patients (4%), external trauma in 12 patients (5%), and unconfirmed diagnosis in 31 cases (12%). Average time between onset and presentation at the ER was 0.6 days for TT, with patients having previously been examined at other hospitals before coming to this institution in 12 cases (36%). Emergency urological surgery was performed in 31 cases (12%), with TT comprising 28 cases (90%), and orchiectomy performed in six cases (21%). (Conclusion) Of all patients examined for acute scrotum, epididymitis were high and TT in 13% at the pediatric ER. Average time for TT patients from symptom onset to ER presentation were longer, we must ensure that patients present at earliest possible opportunity requires educating the general population.

Multiple gastrointestinal stromal tumors in neurofibromatosis type 1 treated with laparoscopic surgery.

Gastrointestinal stromal tumors (GISTs) have been reported to occasionally occur in patients with neurofibromatosis type 1 (NF-1), and many cases have had multiple lesions predominantly involving the small intestine. We report herein a case of multiple GISTs associated with NF-1 from whom laparoscopic surgery was beneficial. In a 79-year-old female admitted with anemia and melena, the abdominal computed tomography revealed a tumor arising from the small intestine. Laparoscopic surgery was performed, and another small tumor was revealed during laparoscopic observation. Extracorporeal partial and wedge resection of the small intestine were undertaken. Both lesions were diagnosed as typical GISTs of low risk. Laparoscopic surgery would be useful for examination and a minimally invasive approach to tumors of the small intestine, especially on cases with the possibility of multiple tumors.

Headache Caused by Brain Metastases of Castration-resistant Prostate Cancer during Cabazitaxel Therapy.

We describe the case of a 55-year-old man who underwent four cycles of cabazitaxel therapy for castration-resistant prostate cancer (CRPC). After the fourth cycle of cabazitaxel, the patient experienced severe headaches. Brain gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) revealed multiple brain metastases. A few days later, the patient suffered impaired consciousness that progressed rapidly. The patient was treated for the symptoms of increased intracranial pressure and underwent whole-brain radiation. One month later, the patient's consciousness level and headache had improved. Although brain metastases of prostate cancer are rare, the possibility of brain metastases should be considered for prostate cancer patients, especially when a CRPC patient complains of headache. Additionally, even if major conditions such as cerebral hemorrhage are excluded by the use of non-contrast-enhanced computed tomography, brain Gd contrast-enhanced MRI should be performed in consideration of the possibility of brain metastases of prostate cancer.

Can urologists introduce the concept of "oligometastasis" for metastatic bladder cancer after total cystectomy?

We investigated whether the concept of oligometastasis may be introduced to the clinical management of metastatic bladder cancer patients. Our study population comprised 128 patients diagnosed with metastatic bladder cancer after total cystectomy at our 6 institutions between 2004 and 2014. We extracted independent predictors for identifying a favorable. Occurrence that fulfilled all 4 criteria which were independently associated with cancer-specific death was defined as oligometastasis: a solitary metastatic organ; number of metastatic lesions of 3 or less; the largest diameter of metastatic foci of 5cm or less; and no liver metastasis. We evaluated differences in clinical outcomes between patients with oligometastasis (oligometastasis group) and those without oligometastasis (non-oligometastasis group). Overall, there were 43 patients in the oligometastasis group. The 2-year cancer-specific survival rate in the oligometastasis group was 53.3%, which was significantly higher than that in the non-oligometastasis group (16.1%, p<0.001). A multivariate analysis revealed that non-oligometastasis (p<0.001), not performing salvage chemotherapy (p<0.001), and not performing metastatectomy (p=0.028) were independent risk factors for cancer-specific death. In the subgroup of 83 patients who received salvage chemotherapy, 30 were in the oligometastasis group. The 2-year cancer-specific survival rate in the oligometastasis group was 55.0%, which was significantly higher than that in the non-oligometastasis group (22.0%, p=0.005). Non-oligometastasis (p=0.009) was the only independent risk factor for cancer-specific death. We presented that urothelial carcinoma with oligometastasis had a favorable prognosis and responded to systemic chemotherapy. Oligometastasis may be treated as a separate entity in the field of metastatic urothelial carcinoma.

Gefitinib decreases the synthesis of matrix metalloproteinase and the adhesion to extracellular matrix proteins of colon cancer cells.

BACKGROUND: Adhesion to extracellular matrix (ECM) proteins and degradation of basement membranes by matrix metalloproteinase (MMP) play important roles in cancer metastasis. In this study, the effects of gefitinib on the enzymatic activity of MMP and adhesion to ECM proteins in the HT29 colon cancer cell line were investigated. MATERIALS AND METHODS: Microtiter plates, coated with ECM proteins, were used to investigate the adhesion of cancer cells to ECM proteins. The expression of MMPs was examined by zymography and semiquantitative RT-PCR. RESULTS: Gefitinib inhibited MMP-9 and MMP-2 secretion and mRNA expression in HT29 cells. Gefitinib also reduced the ability to adhere to laminin and type IV collagen. These effects were observed at such low doses that gefitinib had neither an antiproliferative effect nor the ability to induce apoptosis. CONCLUSION: Gefitinib decreased the production of MMPs and the adhesion to ECM proteins, important steps associated with cancer metastasis. These results suggest that gefitinib may have antimetastatic activity in colon cancer.

Possible Inhibitory Effect of Erythropoiesis-Stimulating Agents at the Predialysis Stage on Early-Phase Coronary Events after Hemodialysis Initiation.

BACKGROUND: We examined whether the use of erythropoiesis-stimulating agents (ESAs) to correct anemia at the predialysis stage could inhibit early-phase coronary events after hemodialysis initiation. METHODS: We enrolled 242 patients with chronic kidney disease who had received continued medical treatments and initiated maintenance hemodialysis from 1 September 2000 to 31 December 2014 at Toujinkai Hospital. Patients with a previous history of blood transfusion or any cardiovascular events or interventions were excluded. The coronary events were followed for 1 year after initiation of hemodialysis. RESULTS: Coronary events occurred in 51 of 242 patients: 10 patients had acute coronary syndrome [9 with percutaneous coronary intervention (PCI), 1 without intervention], and 41 had elective coronary revascularization (38 PCI and 3 coronary artery bypass graft). ESA was administered in 118 of 242 patients (48.8%). In stepwise logistic analysis, coronary events were positively associated with nonuse of ESA at the predialysis stage (odds ratio 2.66, p = 0.005) and diabetes mellitus (odds ratio 5.33, p < 0.001). When dividing the patients into 4 subgroups by blood hemoglobin (Hb) level (8.5 g/dl) and the use/nonuse of ESA, coronary event-free survival rates were higher (p = 0.005) in those with Hb ≥8.5 g/dl, ESA+ (86.6%, n = 82) and tended to be higher (p = 0.055) in those with Hb <8.5 g/dl, ESA+ (86.1%, n = 36) than in patients with Hb <8.5 g/dl, ESA- (68.6%, n = 86) in a Kaplan-Meier analysis. CONCLUSIONS: The use of ESA to correct anemia at the predialysis stage may inhibit early-phase coronary events after hemodialysis initiation.

The transfection of thymidylate synthase antisense suppresses oncogenic properties of a human colon cancer cell line and augments the antitumor effect of fluorouracil.

5-Fluorouracil (5-FU), a fluoropyrimidine analogue, is one of the most commonly used anticancer drugs for the treatment of gastrointestinal malignancies. Some studies reported that the cytotoxicity of fluoropyrimidines is mediated, in large part, by inhibition of the thymidylate synthase (TS), an essential DNA synthetic enzyme. The aim of this study was to determine if antisense TS technology could augment the chemosensitivity of human cancer cells to 5-FU. The full length coding region of TS cDNA was inversely cloned into the eukaryotic expression vector pCDL81 and transfected into DLD-1 cells. The expression and activity of TS were significantly suppressed in the antisense TS transfected cells. Interestingly, the transfection of antisense TS alone inhibited the cellular growth in vitro. The chemosensitivity to 5-FU was significantly increased in the transfected cells. The 50% inhibition values of 5-FU on DLD-1/anti-TS were approximately one forth that on parental cells. The augmentation of chemosensitivity to 5-FU was also confirmed in a nude mice model. The tumor growth of DLD-1/anti-TS cells was suppressed significantly more than that of DLD-1 cells by the 5-FU. The expression and activity of TS in human colon cancer cells were effectively inhibited by TS antisense treatment and the effect of 5-FU to cancer cells can be augmented. The antisense TS technology could be promising for treatments of gastrointestinal cancers.

Role of 5-aminolevulinic acid (ALA) on active oxygen-scavenging system in NaCl-treated spinach (Spinacia oleracea).

ALA is a key precursor in the biosynthesis of porphyrins such as chlorophyll and heme, and was found to induce temporary elevations in the photosynthesis rate, APX, and CAT; furthermore, treatment with ALA at a low concentration might be correlated to the increase of NaCl tolerance of spinach plants. The photosynthetic rate and the levels of active oxygen-scavenging system in the 3rd leaf of spinach (Spinacia oleracea) plants grown by foliar treatment with 0, 0.18, 0.60 and 1.80 mmol/L 5-aminolevulinic acid under 50 and 100 mmol/L NaCl were analyzed. Plants treated with 0.60 and 1.80 mmol/L ALA showed significant increases in the photosynthetic rate at 50 and 100 mmol/L NaCl, while that of 0.18 mmol/L ALA did not show any changes at 50 mmol/L NaCl and a gradual decrease at 100 mmol/L NaCl. In contrast, the rate with 0 mmol/L ALA showed reduction at both concentrations of NaCl. The increase of hydrogen peroxide content by treatment with 0.60 and 1.80 mmol/L ALA were more controlled than that of 0 mmol/L ALA under both NaCl conditions. These ALA-treated spinach leaves also exhibited a lower oxidized/reduced ascorbate acid ratio and a higher reduced/oxidized glutathione ratio than the 0 mmol/L-treated spinach leaves when grown at both NaCl conditions. With regard to the antioxidant enzyme activities in the leaves, ascorbate peroxidase, catalase, and glutathione reductase activities were enhanced remarkably, most notably at day 3, by treatment with 0.60 and 1.80 mmol/L ALA under both NaCl conditions in comparison to that of 0 and 0.18 mmol/L ALA. These data indicate that the protection against oxidative damage by higher levels of antioxidants and enzyme activities, and by a more active ascorbate-glutathione cycle related to the increase of the photosynthesis rate, could be involved in the increased salt tolerance observed in spinach by treatment with 0.60 to 1.80 mmol/L ALA with NaCl.