Close Relationships Between the PSII Repair Cycle and Thylakoid Membrane Dynamics.

In chloroplasts, a three-dimensional network of thylakoid membranes is formed by stacked grana and interconnecting stroma thylakoids. The grana are crowded with photosynthetic proteins, where PSII-light harvesting complex II (LHCII) supercomplexes often show semi-crystalline arrays for efficient energy trapping, transfer and use. Although light is essential for photosynthesis, PSII is damaged by reactive oxygen species that are generated from primary photochemical reactions when plants are exposed to excess light. Because PSII complexes are embedded in the lipid bilayers of thylakoid membranes, their functions are affected by the conditions of the lipids. Electron paramagnetic resonance (EPR) spin trapping measurements showed that singlet oxygen was formed through peroxidation of thylakoid lipids, suggesting that lipid peroxidation can damage proteins, including the D1 protein. After photodamage, PSII is restored by a specific repair system in thylakoid membranes. In the PSII repair cycle, phosphorylation and dephosphorylation of the PSII proteins control the timing of PSII disassembly and subsequent degradation of the D1 protein. Under light stress, stacked grana turn into unstacked thylakoids with bent grana margins. These structural changes may be closely linked to the mechanisms of the PSII repair cycle because PSII can move more easily from the grana core to the stroma thylakoids through an expanded stromal gap between each thylakoid. Thus, plants modulate the structure of thylakoid membranes under high light to carry out efficient PSII repair. This review focuses on the behavior of the PSII complex and the active role of structural changes to thylakoid membranes under light stress.

The entry of cucumber mosaic virus into cucumber xylem is facilitated by co-infection with zucchini yellow mosaic virus.

We investigated the synergistic effects of co-infection by zucchini yellow mosaic virus (ZYMV) and cucumber mosaic virus (CMV) on viral distribution in the vascular tissues of cucumber. Immunohistochemical observations indicated that ZYMV was present in both the phloem and xylem tissues. ZYMV-RNA was detected in both the xylem wash and guttation fluid of ZYMV-inoculated cucumber. Steam treatment at a stem internode indicated that ZYMV enters the xylem vessels and moves through them but does not cause systemic infection in the plant. CMV distribution in singly infected cucumbers was restricted to phloem tissue. By contrast, CMV was detected in the xylem tissue of cotyledons in plants co-infected with CMV and ZYMV. Although both ZYMV-RNA and CMV-RNA were detected in the xylem wash and upper internodes of steam-treated, co-infected cucumbers grown at 24 °C, neither virus was detected in the upper leaves using an ELISA assay. Genetically modified CMV harboring the ZYMV HC-Pro gene was distributed in the xylem and phloem tissues of singly inoculated cucumber cotyledons. These results indicate that the ZYMV HC-Pro gene facilitates CMV entry into the xylem vessels of co-infected cucumbers.

Central nervous system EBV lymphoproliferative disorder in a patient with rhabdomyosarcoma.

Epstein-Barr virus associated lymphoproliferative disorder (EBV-LPD) occurs in patients with immunodeficiency, but it has not been well described in patients who have received chemotherapy for solid tumors. We describe a child with rhabdomyosarcoma who developed isolated central nervous system (CNS) EBV-LPD during combination chemotherapy with vincristine, actinomycin D and cyclophosphamide. The patient was treated with high-dose methotrexate (HD-MTX) for CNS EBV-LPD and then treated with rituximab in addition to HD-MTX because of the emergence of LPD in the liver. I.v. rituximab combined with HD-MTX might be effective therapy for CNS EBV-LPD.

Palmitate-stimulated monocytes induce adhesion molecule expression in endothelial cells via IL-1 signaling pathway.

Increased intake of saturated fatty acids (SFAs), such as palmitate (Pal), is linked to a higher risk of type 2 diabetes and cardiovascular disease. Although recent studies have investigated the direct effects of SFAs on inflammatory responses in vascular endothelial cells, it remains unknown whether SFAs also induce these responses mediated by circulating cells. In this study, especially focused on adhesion molecules and monocytes, we investigated the indirect effects of Pal on expression and release of ICAM-1 and E-selectin in vascular endothelial cells. Phorbol 12-myristate 13-acetate (PMA)-treated THP-1 (pTHP-1) cells and human monocytes were stimulated with various free fatty acids (FFAs). SFAs, but not unsaturated fatty acids (UFAs), increased interleukin (IL)-1ß secretion and decreased IL-1 receptor antagonist (IL-1Ra) secretion, resulting in an increase in the IL-1ß/IL-1Ra secretion ratio. UFAs dose-dependently inhibited the increase in IL-1ß secretion and decrease in IL-1Ra secretion induced by Pal. Moreover, in human aortic and vein endothelial cells, expression and release of ICAM-1 and E-selectin were induced by treatment with conditioned medium collected from Pal-stimulated pTHP-1 cells and human monocytes, but not by Pal itself. The up-regulated expression and release of adhesion molecules by the conditioned medium were mostly abolished by recombinant human IL-1Ra supplementation. These results suggest that the Pal-induced increase in the ratio of IL-1ß/IL-1Ra secretion in monocytes up-regulates endothelial adhesion molecules, which could enhance leukocyte adhesion to endothelium. This study provides further evidence that IL-1ß neutralization through receptor antagonism may be useful for preventing the onset and development of cardiovascular disease.

Meralgia Paresthetica as a Presentation of Acute Appendicitis in a Girl With Acute Lymphoblastic Leukemia.

A 7-year-old girl with Philadelphia chromosome-positive acute lymphoblastic leukemia developed recurrent fever and meralgia paresthetica (MP) during chemotherapy, which resolved after administration of antibiotics. Five months after the onset of these symptoms, enhanced computed tomography showed a periappendiceal abscess extending into the psoas muscle. The cause of her fever and MP was thought to be appendicitis, which probably developed during induction chemotherapy but did not result in typical abdominal pain. Patients with recurrent fever and MP should be evaluated by imaging examinations including computed tomography to search for appendicitis.

Quality control of photosystem II: direct imaging of the changes in the thylakoid structure and distribution of FtsH proteases in spinach chloroplasts under light stress.

Under light stress, the reaction center-binding protein D1 of PSII is photo-oxidatively damaged and removed from PSII complexes by proteases located in the chloroplast. A protease considered to be responsible for degradation of the damaged D1 protein is the metalloprotease FtsH. We showed previously that the active hexameric FtsH protease is abundant at the grana margin and the grana end membranes, and this homo-complex removes the photodamaged D1 protein in the grana. Here, we showed a change in the distribution of FtsH in spinach thylakoids during excessive illumination by transmission electron microscopy (TEM) and immunogold labeling of FtsH. The change in distribution of the protease was accompanied by structural changes to the thylakoids, which we detected using spinach leaves by TEM after chemical fixation of the samples. Quantitative analyses showed several characteristic changes in the structure of the thylakoids, including shrinkage of the grana, outward bending of the marginal portions of the thylakoids and an increase in the height of the grana stacks under excessive illumination. The increase in the height of the grana stacks may include swelling of the thylakoids and an increase in the partition gaps between the thylakoids. These data strongly suggest that excessive illumination induces partial unstacking of the thylakoids, which enables FtsH to access easily the photodamaged D1 protein. Finally three-dimensional tomography of the grana was recorded to observe the effect of light stress on the overall structure of the thylakoids.

Thermal acclimation of the symbiotic alga Symbiodinium spp. alleviates photobleaching under heat stress.

A moderate increase in seawater temperature causes coral bleaching, at least partially through photobleaching of the symbiotic algae Symbiodinium spp. Photobleaching of Symbiodinium spp. is primarily associated with the loss of light-harvesting proteins of photosystem II (PSII) and follows the inactivation of PSII under heat stress. Here, we examined the effect of increased growth temperature on the change in sensitivity of Symbiodinium spp. PSII inactivation and photobleaching under heat stress. When Symbiodinium spp. cells were grown at 25°C and 30°C, the thermal tolerance of PSII, measured by the thermal stability of the maximum quantum yield of PSII in darkness, was commonly enhanced in all six Symbiodinium spp. tested. In Symbiodinium sp. CCMP827, it took 6 h to acquire the maximum PSII thermal tolerance after transfer from 25°C to 30°C. The effect of increased growth temperature on the thermal tolerance of PSII was completely abolished by chloramphenicol, indicating that the acclimation mechanism of PSII is associated with the de novo synthesis of proteins. When CCMP827 cells were exposed to light at temperature ranging from 25°C to 35°C, the sensitivity of cells to both high temperature-induced photoinhibition and photobleaching was ameliorated by increased growth temperatures. These results demonstrate that thermal acclimation of Symbiodinium spp. helps to improve the thermal tolerance of PSII, resulting in reduced inactivation of PSII and algal photobleaching. These results suggest that whole-organism coral bleaching associated with algal photobleaching can be at least partially suppressed by the thermal acclimation of Symbiodinium spp. at higher growth temperatures.

Safety and efficacy of low-dose methotrexate for pediatric patients with steroid-refractory acute graft-versus-host disease after hematopoietic stem cell transplantation.

Low-dose methotrexate (LD-MTX) has long been included in prophylaxis regimens for acute graft-versus-host disease (aGVHD). In addition, LD-MTX is expected as a treatment option to control aGVHD by regulating the cytokine network. In this study, we retrospectively evaluated 35 patients with steroid-refractory acute GVHD to evaluate the safety and efficacy of LD-MTX as a salvage treatment. LD-MTX was administered weekly at a dose of 10 mg/m(2). Overall, 13 patients (37 %) achieved complete response and three (9 %) achieved partial response within 4 weeks after LD-MTX was initiated without any additional agents. Resolution of manifestations of aGVHD in each evaluable organ was observed in 12 of the 23 cases (52 %) with skin aGVHD and in eight of the 23 cases (35 %) with GI aGVHD. Neutropenia and thrombocytopenia (grades III and IV) were observed in nine (26 %) and 17 patients (49 %), respectively. Fatal infectious complications occurred in only three patients (9 %) after LD-MTX treatment. Of the 35 patients studied, 22 were alive with a median follow-up of 60 months and an overall survival rate (Kaplan-Meier estimate) was 62 %. LD-MTX seems suitable for salvage therapy and will not increase risk of infection. Further evaluation of the use of LD-MTX as salvage therapy for steroid-refractory acute GVHD is warranted.

Efficacy of prophylactic additional cranial irradiation and intrathecal chemotherapy for the prevention of CNS relapse after allogeneic hematopoietic SCT for childhood ALL.

We evaluated the efficacy of CRT and IT chemotherapy, in addition to conditioning including TBI, for the prevention of CNS relapse, in allogeneic HSCT for childhood ALL. From January 1999 to December 2009, a total of 48 patients, without previous or presenting CNS involvement, underwent HSCT for ALL. All patients received myeloablative conditioning including TBI of 12 or 13.2 Gy and IT chemotherapy twice between days -10 and -2 prior to HSCT. Twenty-five patients received CRT prior to TBI (CRT+), and 23 patients did not (CRT-). CRT+ and CRT- patients had a seven-yr EFS rate of 40.0 ± 9.8% and 41.7 ± 10.6%, respectively (p = 0.8252). The seven-yr relapse rates for CRT+ and CRT- patients were 45.0 ± 11.2% and 38.4 ± 11.6%, respectively (p = 0.7460). CNS relapses were evident in 1 (4.0%) CRT+ patient and 1 (4.4%) CRT- patient (p = 1.000). There were no significant differences in EFS and the probability of CNS relapse between CRT+ and CRT- patients. These results demonstrate that CRT and IT chemotherapy, in addition to conditioning chemotherapy, may not be necessary in childhood ALL patients without previous or presenting CNS involvement.

Clinical evaluation of direct composite versus zirconia resin-bonded fixed dental prostheses for a single missing anterior tooth: a short-term multicenter retrospective study.

OBJECTIVES: This study aimed to compare the outcome of a simplified direct composite resin-bonded fixed dental prostheses without reinforcing fibers (CR-RBFDP) and resin-bonded fixed dental prostheses using zirconia (Zr-RBFDP). METHODS: The clinical records of five private practice dental clinics and one university hospital were analyzed. Failure was defined as a RBFDP that was removed or remade for any reason. Survival analyses were performed using log-rank tests. RESULTS: A total of 45 patients (CR-RBFDP, n = 17; Zr-RBFDP, n = 28) were followed up for 3 years. Among the CR-RBFDP cases, 1 case of framework fracture and 2 cases of discoloration occurred, whereas among the Zr-RBFDP cases, 1 case of debonding occurred. The mean duration of observation was 21.9 months. The 3-year survival rate was 92.3% for CR-RBFDP and 91.7% for Zr-RBFDP. Log-rank test showed no significant difference (p = 0.78). CONCLUSIONS: Within the limitations of this short-term retrospective study, the survival rate of CR-RBFDP was not significantly different from that of Zr-RBFDP. Contrary to concerns regarding material strength, CR-RBFDP showed reliable results. This direct composite restoration has the advantages of being less invasive and being completed in a single visit. CLINICAL SIGNIFICANCE: Despite differences in material strength, CR-RBFDPs without fiber reinforcement showed reliable short-term clinical results. This direct composite restoration has the advantage of being less invasive and can be restored in a single visit.

[Central intravenous catheter-related bacteremia due to Chryseobacterium indologenes after cord blood transplantation].

A 3-year-old girl with acute myeloid leukemia underwent unrelated cord blood stem cell transplantation (UCBT) due to primary induction failure. Fourteen days after UCBT, she developed central venous catheter (CVC)-related bloodstream infection due to Chryseobacterium indologenes. Despite ciprofloxacin and minocycline being administered according to the results of susceptibility, a high grade fever recurred. Therefore, the CVC was removed 21 days after UCBT and symptoms related to CVC infection improved. Although C. indologenes is widely distributed in nature, it is a rare pathogen in humans. Most cases of C. indologenes bacteremia have been found in immunocompromised patients with malignancies and diabetes mellitus. C. indologenes exhibits specific characteristics, including the progression of resistance to antibiotics and the formation of a biofilm. Therefore, removal of the CVC appears to be the most reasonable treatment for CVC infection due to C. indologenes in patients undergoing hematopoietic stem cell transplantation if clinical symptoms do not improve after appropriate antibiotic therapy.

A novel sapelovirus-like virus isolation from wild boar.

A novel sapelovirus-like virus was isolated from a wild boar (Sus scrofa). In this study, partial viral genomic nucleotide sequences were determined using the rapid determination system of viral nucleic acid sequences (RDV) ver. 3.1, which we recently developed for discovering novel viruses. Phylogenetic analysis of VP1 and 3A proteins and their encoding nucleotide sequences of enteroviruses and sapeloviruses indicated that the isolated virus was closely related to porcine sapelovirus. RT-PCR detected viral sequences in six of 48 wild boar fecal samples.

Novel virus discovery in field-collected mosquito larvae using an improved system for rapid determination of viral RNA sequences (RDV ver4.0).

In this study, we improved a method for rapid determination of viral RNA sequences (RDV) to overcome the limitations of previous versions. The RDV ver4.0 method can detect RNA sequences with at least 1,000 copies as starting material. A novel virus, which was isolated from field-collected Aedes aegypti larvae in the Phasi Charoen district of Thailand using C6/36 cells, was identified using the RDV ver4.0 protocol. The virus was named Phasi Charoen virus (PhaV). We used a high-throughput pyrosequencing approach to obtain more information about the genome sequence of PhaV. Analysis of a phylogenic tree based on amino acid sequences strongly suggested that PhaV belongs to the family Bunyaviridae.

Prevalence of Frailty Assessed by Fried and Kihon Checklist Indexes in a Prospective Cohort Study: Design and Demographics of the Kyoto-Kameoka Longitudinal Study.

OBJECTIVE: The Kyoto-Kameoka Study was launched in 2011-2012 to identify the associations among food intake, nutritional status, physical activity, oral function, quality of life or social capital, the use of long-term care insurance (LTCI) system, and healthy lifespan in community-dwelling older people as a part of the World Health Organization Safe Community program. DESIGN: A prospective cohort study, reporting baseline demographics (cross-sectional data). SETTING AND PARTICIPANTS: We conducted 2 mailed self-administered questionnaire surveys; one is a complete population survey with a comprehensive survey of needs in the sphere of daily life (NSDL) that included 2 different frailty indexes, the Kihon Checklist (KCL) and the Fried phenotype, socioeconomic status, general and psychological health, and social relationships; followed by the more detailed Health and Nutrition Survey. A slightly modified NSDL survey was conducted again in 2013. Survival time, LTCI certification, and medical and long-term care costs after the baseline survey will be followed. RESULTS: Of 18,231 NSDL questionnaires distributed, 13,294 people responded (response rate: 72.92%; mean age 73.7 ± 6.4 and 75.1 ± 7.2 years for men and women, respectively; 12,054 people without and 1240 with LTCI certification). In people without LTCI, the proportion of robust, prefrail, and frail were 30.3%, 59.8%, and 9.9% in men and 25.3%, 64.7%, and 10.0% in women, according to the Fried index. The proportion of frail people as defined by KCL ≥7 was 30.8% in men and 33.3% in women. CONCLUSIONS: The study is the first to document frailty prevalence using both Fried and KCL measures with a complete city population survey among older Japanese in the community as a part of World Health Organization Safe Community program. The study is expected to provide valuable evidence of the effects of lifestyle habits on long-term care prevention and healthy life span.

Quality control of Photosystem II: the molecular basis for the action of FtsH protease and the dynamics of the thylakoid membranes.

The reaction center-binding D1 protein of Photosystem II is damaged by excessive light, which leads to photoinhibition of Photosystem II. The damaged D1 protein is removed immediately by specific proteases, and a metalloprotease FtsH located in the thylakoid membranes is involved in the proteolytic process. According to recent studies on the distribution and organization of the protein complexes/supercomplexes in the thylakoid membranes, the grana of higher plant chloroplasts are crowded with Photosystem II complexes and light-harvesting complexes. For the repair of the photodamaged D1 protein, the majority of the active hexameric FtsH proteases should be localized in close proximity to the Photosystem II complexes. The unstacking of the grana may increase the area of the grana margin and facilitate easier access of the FtsH proteases to the damaged D1 protein. These results suggest that the structural changes of the thylakoid membranes by light stress increase the mobility of the membrane proteins and support the quality control of Photosystem II.

Quality control of photosystem II: lipid peroxidation accelerates photoinhibition under excessive illumination.

Environmental stresses lower the efficiency of photosynthesis and sometimes cause irreversible damage to plant functions. When spinach thylakoids and Photosystem II membranes were illuminated with excessive visible light (100-1,000 µmol photons m(-1) s(-1)) for 10 min at either 20°C or 30°C, the optimum quantum yield of Photosystem II decreased as the light intensity and temperature increased. Reactive oxygen species and endogenous cationic radicals produced through a photochemical reaction at and/or near the reaction center have been implicated in the damage to the D1 protein. Here we present evidence that lipid peroxidation induced by the illumination is involved in the damage to the D1 protein and the subunits of the light-harvesting complex of Photosystem II. This is reasoned from the results that considerable lipid peroxidation occurred in the thylakoids in the light, and that lipoxygenase externally added in the dark induced inhibition of Photosystem II activity in the thylakoids, production of singlet oxygen, which was monitored by electron paramagnetic resonance spin trapping, and damage to the D1 protein, in parallel with lipid peroxidation. Modification of the subunits of the light-harvesting complex of Photosystem II by malondialdehyde as well as oxidation of the subunits was also observed. We suggest that mainly singlet oxygen formed through lipid peroxidation under light stress participates in damaging the Photosystem II subunits.

Identification and molecular characterization of a new nonsegmented double-stranded RNA virus isolated from Culex mosquitoes in Japan.

Two infectious agents were isolated from Culex species mosquitoes in Japan and were identified as distinct strains of a new RNA virus by a method for sequence-independent amplification of viral nucleic acids. The virus designated Omono River virus (OMRV) replicated in mosquito cells in which it produced a severe cytopathic effect. Icosahedral virus particles of approximately 40 nm in diameter were detected in the cytoplasm of infected cells. The OMRV genome was observed to consist of a nonsegmented, 7.6-kb double-stranded RNA (dsRNA) and contain two overlapping open reading frames (ORFs), namely ORF1 and ORF2. ORF1 was found to encode a putative dsRNA-binding protein, a major capsid protein, and other putative proteins, which might be generated by co- and/or post-translational processing of the ORF1 polyprotein precursor, and ORF2 was found to encode a putative RNA-dependent RNA polymerase (RdRp), which could be translated as a fusion with the ORF1 product by a -1 ribosomal frameshift. Phylogenetic analysis based on RdRp revealed that OMRV is closely related to penaeid shrimp infectious myonecrosis virus and Drosophila totivirus, which are tentatively assigned to the family Totiviridae. These results indicated that OMRV is a new member of the family of nonsegmented dsRNA viruses infecting arthropod hosts, but not fungal or protozoan hosts.

Investigation of risk factors for prostate cancer patients with bone metastasis based on clinical data.

It has not yet been determined whether certain types of prostate cancer with bone metastasis (M1b PC) are associated with a poor outcome. The present study retrospectively assessed the potential significance of various clinical data in predicting the outcome of M1b PC. The subjects were 104 patients who attended our hospital and received a diagnosis of M1b PC between January 1998 and December 2006. The age of the subjects ranged from 51 to 91 years (median 74). The observation period ranged from 4 to 122 months (median 43). The parameters investigated were T classification, N classification, Gleason score (GS), pre-treatment prostate-specific antigen (PSA) level, extent of disease (EOD) grade, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), calcium and hemoglobin (Hb) levels and platelet count. The 5-year cause-specific survival rate was 56.6% and the 10-year cause-specific survival rate was 34.9%. Log-rank test and Cox univariate analysis identified the following factors with statistically significant differences: pre-treatment PSA level ≥192, N1, GS ≥8, EOD grade 3+4, high LDH, high ALP and low Hb. Multivariate Cox proportional hazard analysis identified the factors GS ≥8 and high LDH with significant differences. The hazard ratio was 4.967 and 2.728, respectively, and the probability value (P) was 0.029 and 0.004, respectively. When the subjects with GS ≥8 and high LDH were classified as the high-risk group, the 5-year cause-specific survival rate was 24.6%. The outcome was significantly poorer in this group (P<0.0001) than in the other group, which had a 5-year cause-specific survival rate of 67.7%. The present study showed that patients with M1b PC with GS ≥8 and high LDH have a very poor outcome and thus should be treated as a high-risk group requiring close follow-up.