Regulation of L-aspartate oxidase contributes to NADP+ biosynthesis in Synechocystis sp. PCC 6803.

Cyanobacteria have been promoted as a biomass resource that can contribute to carbon neutrality. Synechocystis sp. PCC 6803 is a model cyanobacterium that is widely used in various studies. NADP+ and NAD+ are electron receptors involved in energy metabolism. The NADP+/NAD+ ratio in Synechocystis sp. PCC 6803 is markedly higher than that in the heterotrophic bacterium Escherichia coli. In Synechocystis sp. PCC 6803, NADP+ primarily functions as an electron receptor during the light reaction of photosynthesis, and NADP+ biosynthesis is essential for photoautotrophic growth. Generally, the regulatory enzyme of NADP+ biosynthesis is NAD kinase, which catalyzes the phosphorylation of NAD+. However, a previous study suggested that the regulation of another enzyme contributes to NADP+ biosynthesis in Synechocystis sp. PCC 6803 under photoautotrophic conditions. L-Aspartate oxidase is the first enzyme in NAD(P)+ biosynthesis. In this study, we biochemically characterized Synechocystis sp. PCC 6803 L-aspartate oxidase and determined the phenotype of a Synechocystis sp. PCC 6803 mutant overexpressing L-aspartate oxidase. The catalytic efficiency of L-aspartate oxidase from Synechocystis sp. PCC 6803 was lower than that of L-aspartate oxidases and NAD kinases from other organisms. L-Aspartate oxidase activity was affected by different metabolites such as NADP+ and ATP. The L-aspartate oxidase-overexpressing strain grew faster than the wild-type strain under photoautotrophic conditions. The L-aspartate oxidase-overexpressing strain accumulated NADP+ under photoautotrophic conditions. These results indicate that the regulation of L-aspartate oxidase contributes to NADP+ biosynthesis in Synechocystis sp. PCC 6803 under photoautotrophic conditions. These findings provide insight into the regulatory mechanism of cyanobacterial NADP+ biosynthesis.

Smartphone-based distress screening, information provision, and psychotherapy for reducing psychological distress among AYA cancer survivors: protocol for a fully decentralized multicenter randomized controlled clinical trial.

Fear of cancer recurrence (FCR) is a common and distressing condition among adolescents and young adults (AYAs). This study aims to investigate the efficacy of digital interventions, including distress screening-based information provision and smartphone problem-solving therapy, on common psychological distress, especially FCR, in AYA patients with cancer. Participants will be 224 AYA outpatients with cancer aged 15-39 years who will be randomly assigned to either an 8-week smartphone-based intervention or a waitlist control group. This intervention includes smartphone-based distress screening, information provision, and psychotherapy (problem-solving therapy). The primary endpoint will be the Fear of Cancer Recurrence Inventory-Short Form score at week 8. This study will be conducted as a fully decentralized, randomized, and multicenter trial. The study protocol was approved by the Institutional Review Board of Nagoya City University on 19 April 2024 (ID: 46-23-0005). Trial registration: UMIN-CTR: UMIN000054583.

Depletion of tumor-associated macrophages inhibits lung cancer growth and enhances the antitumor effect of cisplatin.

In lung cancer, tumor-associated macrophages (TAMs), especially M2-like TAMs, represent the main tumor progression components in the tumor microenvironment (TME). Therefore, M2-like TAMs may serve as a therapeutic target. The purpose of this study was to investigate the effect of M2-like TAM depletion in the TME on tumor growth and chemotherapy response in lung cancer. The levels of secreted monocyte chemoattractant protein (MCP-1) and prostaglandin E2 (PGE2) in the supernatants of lung cancer cell lines A549 and LLC were evaluated via ELISA. Cell migration assays were performed to assess the recruitment ability of macrophage cell lines THP-1 and J774-1 cells. Differentiation of macrophages was assessed via flow cytometry. Immunohistochemical staining was performed to visualize M2-like TAMs in transplanted lung cancer in mouse. We used the COX-2 inhibitor nimesulide to inhibit the secretion of MCP-1 and PGE2, which promotes macrophage migration and M2-like differentiation. Nimesulide treatment decreased the secretion of MCP-1 and PGE2 from lung cancer cells. Nimesulide treatment suppressed the migration of macrophages by blocking MCP-1. Lung cancer supernatant induced the differentiation of macrophages toward the M2-like phenotype, and nimesulide treatment inhibited M2-like differentiation by blocking MCP-1 and PGE2. In the lung cancer mouse model, treatment with nimesulide depleted M2-like TAMs in the TME and enhanced the tumor inhibitory effect of cisplatin. Our results indicated that blocking the secretion of MCP-1 and PGE2 from tumor cells depleted M2-like TAMs in the TME and the combination therapy with cisplatin considerably suppressed tumor growth in the LLC mouse model.

Gastrointestinal bleeding/ulcer among paediatric cancer patients after proton beam therapy.

BACKGROUND: The details of gastrointestinal bleeding/ulcer in paediatric cancer patients treated with proton beam therapy have not been reported previously. METHODS: Patients aged 15 years or younger at the time of proton beam therapy and whose gastrointestinal tract was included in the irradiated field participated. RESULTS: A total of 124 patients participated in the study; their median age at irradiation was 5.4 years. Concurrent chemotherapies were vincristine-cyclophosphamide (16 patients), irinotecan-based treatment (16 patients), vincristine-cyclophosphamide-ifosfamide-etoposide (14 patients), other chemotherapy (27 patients) and no chemotherapy (51 patients). Gastrointestinal bleeding/ulcer occurred in four patients (3.2%), with no death due to the bleeding/ulcer. The sites of the gastrointestinal bleeding/ulcer were the stomach (two patients) and the duodenum (two patients). The ages of the four patients at PBT were 5.3, 13.8, 14.2 and 14.8 years, which were significantly older than those of patients without GI bleeding/ulcer (p = 0.017). The maximum irradiated doses to the GI tract in the four patients were 43.2, 45, 50.4 and 50.4 gray equivalent, respectively. The concomitant chemotherapy was vincristine-cyclophosphamide-ifosfamide-etoposide 3 and vincristine-cyclophosphamide 1. Weeks from proton beam therapy to bleeding/ulcer were 15, 20, 22 and 264. DISCUSSION AND CONCLUSIONS: Patients who developed gastrointestinal bleeding/ulcer were treated concurrently with vincristine-cyclophosphamide-ifosfamide-etoposide or vincristine-cyclophosphamide, and their ages were older than those of patients without gastrointestinal bleeding/ulcer. Bleeding occurred in the upper gastrointestinal tract in all the cases, and most cases occurred early and during chemotherapy. Upper gastrointestinal irradiation in older children undergoing intensive chemotherapy may increase the risk of developing gastrointestinal complications.

Four-carbon dicarboxylic acid production through the reductive branch of the open cyanobacterial tricarboxylic acid cycle in Synechocystis sp. PCC 6803.

Succinate, fumarate, and malate are valuable four-carbon (C4) dicarboxylic acids used for producing plastics and food additives. C4 dicarboxylic acid is biologically produced by heterotrophic organisms. However, current biological production requires organic carbon sources that compete with food uses. Herein, we report C4 dicarboxylic acid production from CO2 using metabolically engineered Synechocystis sp. PCC 6803. Overexpression of citH, encoding malate dehydrogenase (MDH), resulted in the enhanced production of succinate, fumarate, and malate. citH overexpression increased the reductive branch of the open cyanobacterial tricarboxylic acid (TCA) cycle flux. Furthermore, product stripping by medium exchanges increased the C4 dicarboxylic acid levels; product inhibition and acidification of the media were the limiting factors for succinate production. Our results demonstrate that MDH is a key regulator that activates the reductive branch of the open cyanobacterial TCA cycle. The study findings suggest that cyanobacteria can act as a biocatalyst for converting CO2 to carboxylic acids.

Prognostic and therapeutic factors influencing the clinical outcome of metastatic Ewing sarcoma family of tumors: A retrospective report from the Japan Ewing Sarcoma Study Group.

BACKGROUND: The prognosis of patients with metastatic Ewing sarcoma family of tumors (ESFT) remains poor. PROCEDURE: We retrospectively analyzed 57 patients diagnosed with metastatic ESFT between 2000 and 2018 to identify prognostic and therapeutic factors affecting the clinical outcome. RESULTS: The 3-year overall survival (OS) rate of the entire cohort was 46.8% (95% confidence interval [CI], 33.0-59.4%). Treatment-related death was not observed. Multivariate analysis identified stem cell transplantation (SCT), response to first-line chemotherapy, and bone metastasis as independent risk factors for OS. Objective response rate to first-line chemotherapy was 65.1% in the 43 evaluable patients. There was no significant difference in the response to different types of first-line chemotherapy. Among patients with lung metastasis alone, the 3-year OS rate was higher in 13 patients who received local treatment than in four who did not, although the difference was not significant. CONCLUSIONS: One possible reason for the high OS rates was the absence of treatment-related mortality even in patients receiving SCT, which could be attributed to advances in the management of post-SCT complications. Novel first-line chemotherapy strategies need to be established to improve the disease status prior to SCT in a higher proportion of patients.

Staphylococcus aureus Virulence Affected by an Alternative Nisin A Resistance Mechanism.

Nisin A is a bacteriocin produced by Lactococcus lactis and is widely used as a food preservative. Staphylococcus aureus has the BraRS-VraDE system that provides resistance against low concentrations of nisin A. BraRS is a two-component system that induces the expression of the ABC transporter VraDE. Previously, we isolated a highly nisin A-resistant strain with increased VraDE expression due to a mutation in braRS In this study, we isolated S. aureus MW2 mutants with BraRS-VraDE-independent nisin A resistance. These mutants, designated SAN2 ( S.aureusnisin resistant) and SAN469, had a mutation in pmtR, which encodes a transcriptional regulator responsible for the expression of the pmtABCD operon. As a result, these mutants exhibited increased expression of PmtABCD, a transporter responsible for the export of phenol-soluble modulin (PSM). Characterization of the mutants revealed that they have decreased susceptibility to human ß-defensin-3 (hBD3) and LL37, which are innate immune factors. Additionally, these mutants showed higher hemolytic activity than the original MW2 strain. Furthermore, in a mouse bacteremia model, the SAN2 strain exhibited a lower survival rate than the original MW2 strain. These results indicate that the increased expression of pmtABCD due to a pmtR mutation is an alternative nisin A resistance mechanism that also affects virulence in S. aureusIMPORTANCE Recently, the emergence of antibiotic-resistant bacteria has resulted in serious problems for chemotherapy. In addition, many antibacterial agents, such as disinfectants and food additives, are widely used. Therefore, there is a possibility that bacteria are becoming resistant to some antibacterial agents. In this study, we investigated whether Staphylococcus aureus can become resistant to nisin A, one of the bacteriocins applied as a food additive. We isolated a highly nisin A-resistant strain designated SAN2 that displayed increased expression of Pmt proteins, which are involved in the secretion of virulence factors called phenol-soluble modulins (PSMs). This strain also showed decreased susceptibility to human antimicrobial peptides and increased hemolytic activity. In addition, SAN2 showed increased lethal activity in a mouse bacteremia model. Our study provides new insights into the possibility that the acquisition of resistance against food preservatives may modulate virulence in S. aureus, suggesting that we need to pay more attention to the use of food preservatives together with antibiotics.

Simultaneous increases in the levels of compatible solutes by cost-effective cultivation of Synechocystis sp. PCC 6803.

Synechocystis sp. PCC 6803, a cyanobacterium widely used for basic research, is often cultivated in a synthetic medium, BG-11, in the presence of 4-(2-hydroxyethyl)-1-piperazine ethanesulfonic acid (HEPES) or 2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid buffer. Owing to the high cost of HEPES buffer (96.9% of the total cost of BG-11 medium), the biotechnological application of BG-11 is limited. In this study, we cultured Synechocystis sp. PCC 6803 cells in BG-11 medium without HEPES buffer and examined the effects on the primary metabolism. Synechocystis sp. PCC 6803 cells could grow in BG-11 medium without HEPES buffer after adjusting for nitrogen sources and light intensity; the production rate reached 0.54 g cell dry weight·L-1 ·day-1 , exceeding that of commercial cyanobacteria and Synechocystis sp. PCC 6803 cells cultivated under other conditions. The exclusion of HEPES buffer markedly altered the metabolites in the central carbon metabolism; particularly, the levels of compatible solutes, such as sucrose, glucosylglycerol, and glutamate were increased. Although the accumulation of sucrose and glucosylglycerol under high salt conditions is antagonistic to each other, these metabolites accumulated simultaneously in cells grown in the cost-effective medium. Because these metabolites are used in industrial feedstocks, our results reveal the importance of medium composition for the production of metabolites using cyanobacteria.

Temporal hemiarthroplasty for distal femoral osteosarcoma in early childhood: a case report.

BACKGROUND: Prosthetic reconstruction for distal femoral osteosarcoma is challenging for younger children. We herein report a successful case of limb-sparing surgery for a younger patient with distal femoral osteosarcoma requiring osteo-articular resection. CASE PRESENTATION: A 5-year-old girl with high-grade conventional osteosarcoma in the left distal femur underwent a series of surgeries. After three cycles of neoadjuvant chemotherapy, limb-salvage surgery was planned because femoral rotationplasty had been refused. At 6 years and 2 months old, distal femoral resection and temporary spacer insertion using a 7-mm-diameter intramedullary nail and molded polymethylmethacrylate was performed. At 7 years and 8 months old, secondary surgery was performed because the first spacer had been dislocated and the residual femur became atrophic. The distal end of the residual femur was removed by 1 cm, but the periosteum and induced membrane around polymethylmethacrylate was preserved. In order to stabilize the spacer against the tibia, a custom-made ceramic spacer with a smooth straight 8-mm-diameter stem was utilized. The bone-spacer junction was fixed with polymethylmethacrylate and then covered with the preserved periosteum and induced membrane. After surgery, the bone atrophy improved. At 9 years and 7 months old, the second spacer was removed because it had loosened, and the knee joint was reconstructed using a custom-made growing femoral prosthesis with a curved porous 8.5-mm-diameter stem. Cancellous bone tips from the proximal tibia were grafted around the bone-prosthesis junction underneath the induced membrane. At 10 years and 5 months old, the patient was able to walk unsupported and a radiograph showed further thickening of the cortex of the residual femur without any stress shielding. Although having 5 cm of limb length discrepancy, the patient and her mother were satisfied with the function. The MSTS score was 24 out of 30 points. Repeated limb length extensions are planned. CONCLUSIONS: This case report provides an example of limb-salvage surgery after distal femoral resection in a small child. The use of a temporary spacer utilizing partial cementation and preservation of the periosteum and induced membrane appears to afford a viable limb-salvage option after distal femoral resection for younger children.

Acute Myocardial Infarction in an Adolescent Receiving Anagrelide for Essential Thrombocythemia with Underlying Persistent Coronary Endothelial Dysfunction.

Essential thrombocythemia (ET) is a Philadelphia chromosome-negative myeloproliferative disorder that is characterized by the overproduction of platelets and a marked increase in the numbers of mature megakaryocytes present in the bone marrow. Thrombohemorrhagic disorders are major morbidities of ET, especially those with mutations in the gene encoding Janus kinase 2 (JAK2). In this study, we report the case of an 18-year-old patient with ET carrying JAK2 mutation who developed acute ST-elevation myocardial infarction (STEMI) 5 months after a commencement of anagrelide. Coronary endothelial dysfunction confirmed by positive acetylcholine provocation test lasted a year after the occurrence of STEMI. Furthermore, intracoronary imaging using optical coherence tomography demonstrated non-atheromatous intimal fibrosis possibly due to chronic endothelial damage. The coronary pathologies reflected chronic change potentially associated with properties of ET and JAK2 mutation in addition to hyperviscosity. These observations suggest that the side effect of anagrelide in our patient was considered causative, while underlying chronic endothelial dysfunction and adverse endothelial remodeling may be predisposing factors to his fatal cardiovascular events.

[Pathological Findings of Chronic Effects Observed in the Kidneys Exposed to Antineoplastic Agents in Two Adolescent Patients].

Cisplatin and ifosfamide are well-known nephrotoxic agents that can cause acute and chronic glomerular and/or tubular toxicity. We examined 2 adolescent patients who were receiving cisplatin and ifosfamide treatments. Pathological findings of patient 1 showed acute tubular necrosis-like patchy injury. Tubulointerstitial nephrosis and glomerular sclerosing were revealed in patient 2. These findings were consistent with the known damages induced by cisplatin and ifosfamide. Proteinuria and mild decline of eGFR were noticed after more than 10 months after the completion of the treatment. It is important to monitor such consequences in long-term follow up. Adult based medical services are required for childhood and adolescent cancer survivors.

Antibacterial activity of disodium succinoyl glycyrrhetinate, a derivative of glycyrrhetinic acid against Streptococcus mutans.

Streptococcus mutans is a cariogenic bacterium that localizes in the oral cavity. Glycyrrhetinic acid (GRA) is a major component of licorice extract. GRA and several derivatives, including disodium succinoyl glycyrrhetinate (GR-SU), are known to have anti-inflammatory effects in humans. In this study, the antimicrobial effect of GRA and its derivatives against the S. mutans UA159 strain were investigated. Minimum inhibitory concentrations (MICs) of GRA and GR-SU showed antibacterial activity against the S. mutans strain, whereas other tested derivatives did not. Because GR-SU is more soluble than GRA, GR-SU was used for further experiments. The antibacterial activity of GR-SU against 100 S. mutans strains was evaluated and it was found that all strains are susceptible to GR-SU, with MIC values below 256 µg/mL. A cell viability assay showed that GR-SU has a bacteriostatic effect on S. mutans cells. As to growth kinetics, sub-MICs of GR-SU inhibited growth. The effect of GR-SU on S. mutans virulence was then investigated. GR-SU at sub-MICs suppresses biofilm formation. Additionally, GR-SU greatly suppresses the pH drop caused by the addition of glucose and glucose-induced expression of the genes responsible for acid production (ldh and pykF) and tolerance (aguD and atpD). Additionally, expression of enolase, which is responsible for the carbohydrate phosphotransferase system, was not increased in the presence of GR-SU, indicating that GR-SU suppresses incorporation of sugars into S. mutans. In conclusion, GR-SU has antibacterial activity against S. mutans and also decreases S. mutans virulence.

Homogeneous Photocatalytic Water Oxidation with a Dinuclear Co(III)-Pyridylmethylamine Complex.

A bis-hydroxo-bridged dinuclear Co(III)-pyridylmethylamine complex (1) was synthesized and the crystal structure was determined by X-ray crystallography. Complex 1 acts as a homogeneous catalyst for visible-light-driven water oxidation by persulfate (S2O8(2-)) as an oxidant with [Ru(II)(bpy)3](2+) (bpy = 2,2'-bipyridine) as a photosensitizer affording a high quantum yield (44%) with a large turnover number (TON = 742) for O2 formation without forming catalytically active Co-oxide (CoO(x)) nanoparticles. In the water-oxidation process, complex 1 undergoes proton-coupled electron-transfer (PCET) oxidation as a rate-determining step to form a putative dinuclear bis-µ-oxyl Co(III) complex (2), which has been suggested by DFT calculations. Catalytic water oxidation by 1 using [Ru(III)(bpy)3](3+) as an oxidant in a H2(16)O and H2(18)O mixture was examined to reveal an intramolecular O-O bond formation in the two-electron-oxidized bis-µ-oxyl intermediate, prior to the O2 evolution.

[Use of Transdermal Fentanyl in a Hospital].

Recently, the use of transdermal fentanyl (TDF) has been increasing at our hospital owing to its convenience. Furthermore, TDF tends to be increasingly used for patients who have never used opioids. However, the appropriate criteria for indicating TDF have not been established yet. Therefore, we examined how TDF was prescribed in practice and determined its effective dosage. In 43 cases, the reasons, effects, and side effects of TDF were investigated retrospectively. Of the patients, 60% continued using TDF for 30 days. Meanwhile, approximately 25% of them terminated TDF therapy within 8 days. Of those who discontinued TDF therapy, some entirely stopped taking TDF and others chose other opioids instead because of poor pain control. Before receiving TDF therapy, 17 patients (45%) used oxycodone and 14 (37%) never used opioids. In addition, the main reason for starting TDF in opioid-naive patients was gastrointestinal condition. Between opioid-naive and opioid-using groups, no significant differences were observed in usage duration and incidence of side effects. The side effects included somnolence in 6 patients, delirium in 2 patients, and nausea and vomiting, constipation, and breathing restraint in 1 patient each. TDF was considered as an effective treatment regardless of the previous use of opioids. Nonetheless, careful deliberation is necessary because of the slow effects and difficulty with dosage adjustment.

rre37 Overexpression alters gene expression related to the tricarboxylic acid cycle and pyruvate metabolism in Synechocystis sp. PCC 6803.

The tricarboxylic acid (TCA) cycle and pyruvate metabolism of cyanobacteria are unique and important from the perspectives of biology and biotechnology research. Rre37, a response regulator induced by nitrogen depletion, activates gene expression related to sugar catabolism. Our previous microarray analysis has suggested that Rre37 controls the transcription of genes involved in sugar catabolism, pyruvate metabolism, and the TCA cycle. In this study, quantitative real-time PCR was used to measure the transcript levels of 12 TCA cycle genes and 13 pyruvate metabolism genes. The transcripts of 6 genes (acnB, icd, ppc, pyk1, me, and pta) increased after 4 h of nitrogen depletion in the wild-type GT strain but the induction was abolished by rre37 overexpression. The repression of gene expression of fumC, ddh, and ackA caused by nitrogen depletion was abolished by rre37 overexpression. The expression of me was differently affected by rre37 overexpression, compared to the other 24 genes. These results indicate that Rre37 differently controls the genes of the TCA cycle and pyruvate metabolism, implying the key reaction of the primary in this unicellular cyanobacterium.

Myostatin expression in lung cancer induces sarcopenia and promotes cancer progression.

OBJECTIVES: Many studies have demonstrated that sarcopenia among lung cancer predicts poor prognosis due to cancer progression. However, the cytokines that link sarcopenia and lung cancer progression remain unidentified. This study aimed to investigate whether lung cancer producing myostatin, which induces skeletal muscle atrophy, leads to sarcopenia and promotes cancer progression in patients with resected lung cancer. METHODS: Tumor tissues were obtained from 148 patients who underwent curative resection for lung cancer. Tumor cells were stained with myostatin and tumor-associated macrophages (TAM) in the tumor microenvironment were stained with CD68. We assessed the association between myostatin expression and the clinicopathological features. RESULTS: High myostatin expression in lung cancer was significantly associated with low skeletal muscle mass. The 5-year overall survival and relapse-free survival were significantly worse among patients with high myostatin expression than those with low expression. A multivariate analysis showed that TAM count was positively correlated with high myostatin expression. CONCLUSION: Sarcopenia may be induced by myostatin secreted by lung cancer cells. Moreover, myostatin may promote TAM migration into the tumor microenvironment, leading to advance lung cancer. As a result, patients with high myostatin expression had poor prognosis.

Evaluation of repositioning care provided by non-professionals using a caregiver-assistive device: an experimental study.

As the population ages in Japan and worldwide, the number of informal caregivers, such as family members, providing nursing care to older individuals is increasing. Among caregiving tasks, repositioning care, which causes lower back pain, is frequent and burdensome for caregivers. Therefore, we developed a position-changing device that can adjust and support the care recipient's body in the lateral position. This was a feasibility study of the device-assisted care provided by non-professionals using the device we developed. Of the 40 healthy volunteers enrolled, 17 simulated caregivers and 17 simulated care recipients finally participated in the study. One caregiver and one care recipient were paired to engage in two types of care: device-assisted care and manual care. Furthermore, the care provided by the caregiver and received by the care recipient were evaluated. Non-professionals were able to use the device successfully and safely after a short period of practice, and both caregivers and care recipients rated the device-assisted care positively. The study results suggest that informal caregivers can also provide safe and comfortable care that is less burdensome than manual care by using a caregiver-assistive device.