Comparative analyses of Stvb-allelic genes reveal japonica specificity of rice stripe resistance in Oryza sativa.

Rice stripe, a viral disease, causes widespread damage to japonica rice (Oryza sativa ssp. japonica). A rice stripe virus (RSV) bioassay revealed that many indica and japonica upland varieties exhibit resistance, whereas japonica paddy varieties are susceptible. However, the genetic background for this subspecies-dependent resistance is unclear. Herein, we focused on rice stripe resistance genes located at the Stvb locus. Three resistant alleles, Stvb-i (indica), Stvb (japonica upland), and Stvb-o (Oryza officinalis) were compared with the susceptible allele, stvb-j (japonica paddy). The expression of the resistance genes was higher than that of stvb-j. Sequence comparison revealed that the resistant and susceptible alleles had different 5'-end sequences and 61-bp element(s) in the fourth intron. The insertion of an LTR-retrotransposon modified the exon 1 sequence of stvb-j. We then developed four DNA markers based on gene structure information and genotyped resistant and susceptible varieties. The LTR-retrotransposon insertion was detected only in susceptible varieties. Resistant genotypes were primarily found in indica and upland japonica, whereas paddy japonica carried the susceptible genotype. Our results characterize the genetic differences associated with RSV resistance and susceptibility in O. sativa and provide insights on the application of DNA markers in rice stripe disease management.

Validation of prognostic impact of number of extrathoracic metastases according to the eighth TNM classification: a single-institution retrospective study in Japan.

BACKGROUND: In the eighth edition of the TNM classification of lung cancer, the M1b and M1c descriptors are newly defined by the number of extrathoracic metastases. To verify the prognostic value of these descriptors in Japan, we reclassified our cases and re-evaluated prognosis in M1b and M1c patients. METHODS: All non-small cell lung cancer (NSCLC) patients with extrathoracic metastases who visited Saitama Medical Center from 2010 to 2016 were evaluated, divided according to the eighth edition of the TNM classification criteria into two groups (M1b, patients with single extrathoracic metastasis, and M1c, patients with multiple extrathoracic metastases), and followed up until December 31, 2017. Survival time analysis was performed using the Kaplan-Meier method, and between-group differences in overall survival time (OS) were evaluated by the log-rank test. RESULTS: A total of 231 NSCLC patients were divided into 57 patients with M1b and 174 with M1c. Median OS was 15.2 months (95% confidence interval [CI]: 9.3-19.9) and 7.3 months (95% CI 5.7-10.7) for M1b and M1c, respectively, with no significant between-group difference (P = 0.239). However, after excluding patients with epidermal growth factor receptor (EGFR) mutation or echinoderm microtubule-associated protein-like 4 and anaplastic lymphoma kinase (EML4-ALK) fusion gene, median OS was 12.9 months (95% CI 7.2-19.9) for M1b and 5.4 months (95% CI 3.8-6.3) for M1c, respectively, showing a significant difference (P = 0.029). CONCLUSIONS: The effect of therapy directed toward EGFR mutation or EML4-ALK fusion gene might obscure the significant prognostic difference between M1b and M1c.

The necessity of TEAD4 for early development and gene expression involved in differentiation in porcine embryos.

TEA domain family transcription factor 4 (Tead4) is known to be important for the trophectoderm (TE) segregation in murine embryos. However, the role of TEAD4 in early development of porcine embryos is still unknown. We examined TEAD4 expression patterns and attempted to determine the functions of TEAD4 during porcine preimplantation development using RNA interference. TEAD4 mRNA was upregulated from the 2-4-cell to 8-16-cell stages and then decreased to the blastocyst stage. Nuclear localization of TEAD4 protein was detected at the 16-cell stage, as well as at subsequent developmental stages. In porcine embryos injected with TEAD4 siRNA, transformation from morula to blastocyst was inhibited. Although TEAD4 downregulation did not affect the expression levels of POU class 5 homeobox 1 (OCT-4), transcription of SRY-related HMG-box gene 2 (SOX2) was detected at high level in TEAD4-downregulated embryos. It is possible that TEAD4 contributes to blastocyst formation in porcine embryos through downregulation of SOX2 expression. Collectively, our results indicate that TEAD4 is an important factor for the preimplantation development of porcine embryos.

Serotonin attenuates biotic stress and leads to lesion browning caused by a hypersensitive response to Magnaporthe oryzae penetration in rice.

The hypersensitive response (HR) of plants is one of the earliest responses to prevent pathogen invasion. A brown dot lesion on a leaf is visual evidence of the HR against the blast fungus Magnaporthe oryzae in rice, but tracking the browning process has been difficult. In this study, we induced the HR in rice cultivars harboring the blast resistance gene Pit by inoculation of an incompatible M. oryzae strain, which generated a unique resistance lesion with a brown ring (halo) around the brown fungal penetration site. Inoculation analysis using a plant harboring Pit but lacking an enzyme that catalyzes tryptamine to serotonin showed that high accumulation of the oxidized form of serotonin was the cause of the browning at the halo and penetration site. Our analysis of the halo browning process in the rice leaf revealed that abscisic acid enhanced biosynthesis of serotonin under light conditions, and serotonin changed to the oxidized form via hydrogen peroxide produced by light. The dramatic increase in serotonin, which has a high antioxidant activity, suppressed leaf damage outside the halo, blocked expansion of the browning area and attenuated inhibition of plant growth. These results suggest that serotonin helps to reduce biotic stress in the plant by acting as a scavenger of oxygen radicals to protect uninfected tissues from oxidative damage caused by the HR. The deposition of its oxide at the HR lesion is observed as lesion browning.

Alterations in α4ß2 nicotinic receptors in cognitive decline in Alzheimer's aetiopathology.

Nicotinic acetylcholine receptor subtype α4ß2 is considered important in the regulation of attention and memory, and cholinergic degeneration is known as one pathophysiology of Alzheimer's disease. Brain amyloid-ß protein deposition is also a key pathological marker of Alzheimer's disease. Recent amyloid-ß imaging has shown many cognitively normal subjects with amyloid-ß deposits, indicating a missing link between amyloid-ß deposition and cognitive decline. To date, the relationship between the α4ß2 nicotinic acetylcholine receptor and amyloid-ß burden has not been elucidated in vivo. In this study we investigated the relation between α4ß2 nicotinic acetylcholine receptor availability in the brain, cognitive functions and amyloid-ß burden in 20 non-smoking patients with Alzheimer's disease at an early stage and 25 age-matched non-smoking healthy elderly adults by measuring levels of α4ß2 nicotinic acetylcholine receptor binding estimated from a simplified ratio method (BPRI) and Logan plot-based amyloid-ß accumulation (BPND) using positron emission tomography with α4ß2 nicotinic acetylcholine receptor tracer (18)F-2FA-85380 and (11)C-Pittsburgh compound B. The levels of tracer binding were compared with clinical measures for various brain functions (general cognition, episodic and spatial memory, execution, judgement, emotion) using regions of interest and statistical parametric mapping analyses. Between-group statistical parametric mapping analysis showed a significant reduction in (18)F-2FA-85380 BPRI in the cholinergic projection region in patients with Alzheimer's disease with a variety of (11)C-Pittsburgh compound B accumulation. Spearman rank correlation analyses showed positive correlations of (18)F-2FA-85380 BPRI values in the medial frontal cortex and nucleus basalis magnocellularis region with scores of the Frontal Assessment Battery (a test battery for executive functions and judgement) in the Alzheimer's disease group (P < 0.05 corrected for multiple comparison), and also positive correlations of the prefrontal and superior parietal (18)F-2FA-85380 BPRI values with the Frontal Assessment Battery score in the normal group (P < 0.05 corrected for multiple comparison). These positive correlations indicated an in vivo α4ß2 nicotinic acetylcholine receptor role in those specific functions that may be different from memory. Both region of interest-based and voxelwise regression analyses showed a negative correlation between frontal (11)C-Pittsburgh compound B BPND and (18)F-2FA-85380 BPRI values in the medial frontal cortex and nucleus basalis magnocellularis region in patients with Alzheimer's disease (P < 0.05 corrected for multiple comparison). These findings suggest that an impairment of the cholinergic α4ß2 nicotinic acetylcholine receptor system with the greater amount of amyloid deposition in the system plays an important role in the pathophysiology of Alzheimer's disease.

Genetic relationship of energy balance predicted from milk traits with fertility in Japanese Holsteins.

We predicted the energy balance of cows from milk traits and estimated the genetic correlations of predicted energy balance (PEB) with fertility traits for the first three lactations. Data included 9,646,606 test-day records of 576,555 Holstein cows in Japan from 2015 to 2019. Genetic parameters were estimated with a multiple-trait model in which the records among lactation stages and parities were treated as separate traits. Fertility traits were conception rate at first insemination (CR), number of inseminations (NI), and days open (DO). Heritability estimates of PEB were 0.28-0.35 (first lactation), 0.15-0.29 (second), and 0.09-0.23 (third). Estimated genetic correlations among lactation stages were 0.85-1.00 (first lactation), 0.73-1.00 (second), and 0.64-1.00 (third). Estimated genetic correlations among parities were 0.82-0.96 (between first and second), 0.97-0.99 (second and third), and 0.69-0.92 (first and third). Estimated genetic correlations of PEB in early lactation with fertility were 0.04 to 0.19 for CR, -0.03 to -0.19 for NI, and -0.01 to -0.24 for DO. Genetic improvement of PEB is possible. Lower PEB in early lactation was associated with worse fertility, suggesting that improving PEB in early lactation may improve reproductive performance.

Molecular imaging of aquaglycero-aquaporins: its potential for cancer characterization.

Aquaglycero-aquaporins (agAQPs) are one of the water channel proteins located in the cell membrane that transport not only water but also some small solutes such as glycerol. Since agAQPs are involved in cancer proliferation and malignancy, it might be possible to utilize them as new targets for cancer molecular imaging. In this study, we investigated whether agAQPs can be specifically targeted by using [(14)C]-labeled glycerol ([(14)C]glycerol), which passes through agAQPs. In the in vitro experiments, comparing the cancer cell lines with different expression levels of AQP3 and AQP9, major agAQPs known to be expressed in cancers, and examining the effect of their inhibitors on these cells, the expression of AQP3 and AQP9 in cell lines was shown to be closely related to [(14)C]glycerol uptake. When [(14)C]glycerol was injected into tumor-bearing mice, Spearman's rank coefficient analysis revealed that radioactivity levels in tumor and in plasma were mutually correlated only in tumors expressing agAQPs at a high level. These results indicate the possibility of using agAQPs as new targets to characterize cancer using radiolabeled glycerol as a molecular probe.

The influence of blood glucose on neutrophil function in individuals without diabetes.

We assessed the association of neutrophil function with glycated hemoglobin (HbA1c) levels in a Japanese general population. Participants were 809 males and females who were over 20 years old living in the Iwaki region in Aomori Prefecture located in northern Japan. Lifestyle parameters (smoking, alcohol consumption, and exercise habits), HbA1c and neutrophil function such as reactive oxygen species (ROS) production capability and phagocytic activity (PA) were measured. ROS production capability was measured before and after phagocytic stimulus to obtain basal ROS production and stimulated ROS production. Level of HbA1c had a positive correlation with basal ROS production (p=0.053), a negative correlation with stimulated ROS production (p=0.072) and PA (p=0.059) only in post-menopausal groups, and not in pre-menopausal groups. However, there were no correlations between levels of HbA1c and neutrophil functions in male. In conclusion, in the present study, despite the presence of diabetes, chronic hyperglycemia was found to cause an increase in daily basal ROS production of neutrophils, and increased susceptibility to infection caused by reduced neutrophilic reaction in females in their menopause. Therefore, from the oxidative point of view, strict glycemic control is necessary to prevent post-menopausal females from developing diabetic complications in spite of the presence of diabetes.

Impact of Locoregional Therapies for Brain Lesions on Survival in Patients With Non-small Cell Lung Cancer With Multiple Extrathoracic Metastases.

BACKGROUND/AIM: The treatment of brain metastases in patients with non-small cell lung cancer (NSCLC) typically involves surgery, irradiation, and chemotherapy (single or combination therapy). However, the impact of these therapies on the survival of patients with NSCLC with multiple extrathoracic metastases has not yet been determined. Therefore, in the present study, we examined the prognostic effect of multimodal treatment for brain metastases in patients with NSCLC with multiple extrathoracic metastases in the absence of driver mutations. PATIENTS AND METHODS: Patients with NSCLC with multiple extrathoracic metastases (including at least one brain metastasis), who visited Saitama Medical Center, Saitama Medical University from January 1, 2010 to December 31, 2016, were enrolled in this study; follow-up was conducted until December 31, 2021. RESULTS: A total of 56 patients were enrolled, including 12 and 44 patients with single and multiple brain metastases, respectively. The median overall survival (OS) for all patients was 4.9 months, and did not differ significantly between patients with single and multiple brain metastases (3.0 vs. 4.9 months, respectively). The selection of locoregional treatment for brain metastases did not depend on Karnofsky performance status (p=0.0862). Among patients with multiple brain metastases, the OS for those who underwent craniotomy followed by whole brain radiation therapy (WBRT), those who received only WBRT, and those treated without locoregional therapy was 47.7, 3.9, and 15.9 months, respectively (p=0.00382). CONCLUSION: Surgical resection followed by radiation therapy is an effective treatment option for brain metastases in patients with multiple metastases. However, WBRT alone did not improve prognosis.

Basic studies on radioimmunotargeting of CD133-positive HCT116 cancer stem cells.

As cancer stem cells (CSCs) are postulated to play critical roles in cancer development, including metastasis and recurrence, CSC imaging would provide valuable information for cancer treatment and lead to CSC-targeted therapy. To assess the possibility of in vivo CSC targeting, we conducted basic studies on radioimmunotargeting of cancer cells positive for CD133, a CSC marker recognized in various cancers. Antibodies against CD133 were labeled with ¹²5I, and their in vitro cell binding properties were tested. Using the same isotype IgG as a control, in vivo biodistribution of the labeled antibody retaining immunoreactivity was examined in mice bearing an HCT116 xenograft in which a population of the cancer cells expressed CD133. Intratumoral distribution of the labeled antibody was examined and compared to the CD133 expression pattern. The ¹²5I-labeled anti-CD133 antibody showed a modest but significantly higher accumulation in the HCT116 xenograft compared to the control IgG. The intratumoral distribution of the labeled antibody mostly overlapped with the CD133 expression, whereas the control IgG was found in the area close to the necrotic tumor center. Our results indicate that noninvasive in vivo targeting of CSCs could be possible with radiolabeled antibodies against cell membrane markers.

Prediction of energy balance from milk traits of Holsteins in Japan.

We predicted the energy balance (EB) of Holstein cows in Japan from milk traits obtained by herd testing. Records covered 156 lactations of 102 cows. The number of artificial inseminations was highest, and the first conception rate was lowest in the low-EB group. Four prediction models were developed-for the whole lactation and for the early, middle, and late stages of lactation-with 20 variables, covering days in milk (DIM), milk yield, and milk composition traits. The actual and predicted EB means agreed well within DIM classes; the means of the residuals were smaller in the lactation stage models than in the all-lactation model, but the standard deviations (SDs) of the residuals were similar among models. After data reduction, the SDs of the residuals for 100 iterations were <1 throughout lactation in both types of models when n = 100. After model reduction, including the daily change of milk yield as a variable minimized the SDs of the residuals. Our equations for herd-level EB prediction have potential for use in genetic evaluation.

Durable panicle blast-resistance gene Pb1 encodes an atypical CC-NBS-LRR protein and was generated by acquiring a promoter through local genome duplication.

Rice blast is one of the most widespread and destructive plant diseases worldwide. Breeders have used disease resistance (R) genes that mediate fungal race-specific 'gene-for-gene' resistance to manage rice blast, but the resistance is prone to breakdown due to high pathogenic variability of blast fungus. Panicle blast 1 (Pb1) is a blast-resistance gene derived from the indica cultivar 'Modan'. Pb1-mediated resistance, which is characterized by durability of resistance and adult/panicle blast resistance, has been introduced into elite varieties for commercial cultivation. We isolated the Pb1 gene by map-based cloning. It encoded a coiled-coil-nucleotide-binding-site-leucine-rich repeat (CC-NBS-LRR) protein. The Pb1 protein sequence differed from previously reported R-proteins, particularly in the NBS domain, in which the P-loop was apparently absent and some other motifs were degenerated. Pb1 was located within one of tandemly repeated 60-kb units, which presumably arose through local genome duplication. Pb1 transcript levels increased during the development of Pb1+ cultivars; this expression pattern accounts for their adult/panicle resistance. Promoter:GUS analysis indicated that genome duplication played a crucial role in the generation of Pb1 by placing a promoter sequence upstream of its coding sequence, thereby conferring a Pb1-characteristic expression pattern to a transcriptionally inactive 'sleeping' resistance gene. We discuss possible determinants for the durability of Pb1-mediated blast resistance.

Initial rapidity of tumor growth as a prognostic factor for the therapeutic effect of immune-checkpoint inhibitors in patients with non-small cell lung cancer: evaluation for linear and non-linear correlation.

BACKGROUND: Immune-checkpoint inhibitors (ICIs) have been increasingly used for non-small cell lung cancer (NSCLC) treatment in recent years. Although insufficient, the rate of programmed death-ligand 1 expression has been adopted as a predictor of ICI efficacy. We evaluated tumor growth rate as a clinically easy-to-use predictor of the therapeutic effect of ICIs. METHODS: This study is a single-institution retrospective study in Japan. NSCLC patients treated with nivolumab, pembrolizumab, or atezolizumab at Saitama Medical Center from January 1, 2016 to December 31, 2018 were enrolled, and followed until December 31, 2020. We defined and calculated the initial rapidity of tumor progression (IRP) as: the increase in the sum of the diameters of intrathoracic tumors and lymph nodes on two series of chest computed tomography (CT) scans (one obtained at an initial checkup and the other obtained immediately before the first treatment) divided by the number of days between these CT scans. Two coefficients were calculated: the maximal information coefficient (MIC) between IRP and time to treatment failure (TTF) using the Python package with minepy library, and the Spearman's rank correlation coefficient. RESULTS: A total of 55 patients (median age, 70 years; 47 men) were enrolled. The median TTF with ICIs was 126 days, and four patients continued to receive ICI treatment at the end of the follow-up. The MIC between IRP and TTF was 0.302 with weak correlation, and the Spearman's rank correlation coefficient was -0.347 (P=0.00938). CONCLUSIONS: The initial tumor growth rate had a negative linear correlation with the therapeutic effect of ICIs.

Functional inhibition of heat shock protein 70 by VER-155008 suppresses pleural mesothelioma cell proliferation via an autophagy mechanism.

BACKGROUND: Pleural mesothelioma, a devastating asbestos-associated malignancy, urgently requires a novel effective therapy. Heat shock protein 70 (HSP70), which is synthesized in the cell response to protein damage, is expected to be a new target for antitumor treatment. In addition to its well-known protein refolding function, HSP70 regulates cell proliferation through different pathways, including PI3K/AKT/mTOR, and autophagy in malignant cells. In this study, we attempted to clarify the effects of VER-155008, an HSP70 inhibitor, on pleural mesothelioma. METHODS: Human pleural mesothelioma cell lines 211H, H2452 and H28 were cultured with VER-155008, and protein expression, cell proliferation, colony formation, cell cycle, synergistic effect with cisplatin, and autophagy induction were analyzed. RESULTS: In mesothelioma cell lines, VER-155008 (5.0 µM or more) inhibited cell growth and colony formation, accompanied by G1 cell cycle arrest. According to western blot analysis, VER-155008 reduced p-AKT expression. However, VER-155008 failed to show a synergistic effect with cisplatin on cell growth. Mesothelioma cells transfected with the novel plasmid pMRX-IP-GFP-LC3-RFP-LC3ΔG, which was developed for the quantitative and statistical estimation of macroautophagy, showed enhanced macroautophagy upon treatment with VER-155008 and gefitinib which is an EGFR-tyrosine kinase inhibitor. In addition, fetal bovine serum deprivation induced macroautophagy was further enhanced by VER-155008. CONCLUSIONS: On the basis of these results, functional HSP70 inhibition by VER-155008 suppressed cell growth in pleural mesothelioma cells, accompanied by enhanced macroautophagy. HSP70 inhibition is thus expected to become a new strategy for treating mesothelioma. KEY POINTS: Significant findings of the study In pleural mesothelioma cells, inhibition of HSP70 function by VER-155008 suppressed cell proliferation accompanied by induction of autophagy which was synergistically enhanced under the starvation condition, whereas gefitinib, an EGFR-TKI, did not show the same synergistic effect in autophagy. What this study adds The inhibition of HSP70 induced autophagy and suppressed cell proliferation in mesothelioma cells.

Fusion protein based on Grb2-SH2 domain for cancer therapy.

Epidermal growth factor receptor (EGFR) is one of the very attractive targets for cancer therapy. In this study, we generated fusion proteins containing one or two Src-homology 2 (SH2) domains of growth factor receptor bound protein 2 (Grb2), which bind to phosphorylated EGFR, added with HIV-1 transactivating transcription for cell membrane penetration (termed TSF and TSSF, respectively). We examined if they can interfere Grb2-mediated signaling pathway and suppress tumor growth as expected from the lack of SH3 domain, which is necessary to intermediate EGFR-Grb2 cell signaling, in the fusion proteins. The transduction efficiency of TSSF was similar to that of TSF, but the binding activity of TSSF to EGFR was higher than that of TSF. Treatment of EGFR-overexpressing cells showed that TSSF decreased p42-ERK phosphorylation, while TSF did not. Both the proteins delayed cell growth but did not induce cell death in culture. TSSF also significantly suppressed tumor growth in vivo under consecutive administration. In conclusion, TSSF showed an ability to inhibit EGFR-Grb2 signaling and could have a potential to treat EGFR-activated cancer.

[Acute-onset eosinophilic leukemia associated with tumor lysis syndrome after imatinib and steroid pulse therapy].

An 83-year-old woman had been suffering from palpitations and fatigue for a month. An annual screening test revealed an increased WBC count so she was referred to our hospital. CBC showed extremely elevated WBC count (186,300/microl), in which the population of blastic eosinophils was over 90%. The eosinophils expressed CD7/13/33/34/DR, and the karyotype demonstrated 47,XX,+8. The fusion gene of FIP1-LP/PDGFRalpha in peripheral blood was negative. As plural effusion due to the underlying disease progressively worsened, she was given prednisolone and hydroxyurea, but the effect was limited. Steroid pulse therapy and imatinib (100 mg/day) were administrated. As a result, a prompt response was observed. The WBC count rapidly decreased, but tumor lysis syndrome led to acute renal failure and disseminated intravasucular coagulation appeared. Supportive therapies such as artificial dialysis and transfusions were conducted, but unfortunately she died because of alveolar hemorrhage.

Effect of Downregulating the Hippo Pathway Members YAP1 and LATS2 Transcripts on Early Development and Gene Expression Involved in Differentiation in Porcine Embryos.

In mouse development, differentiation of the inner cell mass (ICM) and trophectoderm (TE) during the transition from the morula to blastocyst stage is regulated by the Hippo pathway; however, the functions of the Hippo pathway in porcine embryogenesis have not been investigated. In the present study, we examined the gene expression patterns of the Hippo pathway members yes-associated protein 1 (YAP1) and large tumor suppressor 2 (LATS2) and the functions of these genes during porcine preimplantation development using RNA interference. Both YAP1 and LATS2 mRNA levels were shown high in the in vitro matured oocytes and 1-cell stage embryos and fell progressively with development. YAP1 nuclear localization was detected at the morula and blastocyst stages. Downregulation of either YAP1 or LATS2 inhibited porcine preimplantation development and affected the expression levels of POU class 5 homeobox 1 (OCT-4) and SRY-related HMG-box gene 2 (SOX2), transcription factors necessary for the ICM/TE differentiation. Taken together, YAP1 and LATS2 are essential for porcine preimplantation development, and it is possible that the Hippo pathway has important roles in porcine ICM/TE segregation.

Stvb-i, a Rice Gene Conferring Durable Resistance to Rice stripe virus, Protects Plant Growth From Heat Stress.

Disease resistance is affected by temperature. A rice gene, Stvb-i, is known to have conferred sustained resistance to Rice stripe virus (RSV) despite global warming. Stvb-i protects plants from growth stunting caused by RSV. The underlying resistance mechanism is unclear. Here, Stvb-i showed stable RSV resistance for 20 years in laboratory experiments. This gene encodes a protein distinct from well-studied plant disease-resistance proteins. It has a domain homologous to the histidine kinase/heat-shock protein 90-like ATPase superfamily. Rice has three paralogous genes including Stvb-i. The genes are expressed mainly in meristematic tissues. In the initial period after viral inoculation, RSV multiplication enhanced Stvb-i, whereas Stvb-i suppressed RSV multiplication. Stvb-i silencing inhibited plant growth regardless of viral infection, and silencing of the other paralogous gene that located closely to Stvb-i caused morphological abnormalities. The results suggested that the Stvb-i and its paralogs are related to plant development; especially, Stvb-i supports meristem growth, resulting in plant growth stabilizing. Growth stunting in the Stvb-i-silenced plants was more severe under repetitive heat stress, suggesting that Stvb-i contributed to the attenuation of heat damage in plant development. The symptoms of RSV infection (chlorosis, wilting, stunting, fewer tillers, and defective panicles) were similar to those of heat damage, suggesting that RSV multiplication induces heat-like stress in meristematic cells. Our findings suggest that the mechanism of meristem growth protection conferred by Stvb-i allows plants to withstand both heat stress and RSV multiplication. The suppression of RSV multiplication by the Stvb-i function in meristems results in durable resistance.

Detection of white head symptoms of panicle blast caused by Pyricularia oryzae using cut-flower dye.

BACKGROUND: Breeding of rice with panicle resistance to rice blast disease caused by Pyricularia oryzae is a challenge towards sustainable rice production. Methods for accurate estimation of disease severity can support breeding. White head symptoms are a commonly used index of panicle blast in the field. As the development mechanism of this symptom remains unclear, we used cut-flower dye (CFD) solution to visualize the infected panicle tissues. RESULTS: CFD delineated the edge of white head symptoms in rice panicles artificially infected with P. oryzae. Hyphae within the tissues were confirmed through staining with a fluorescent wheat germ agglutinin conjugate. Hyphal density was obviously diminished at the dye edge. Growing hyphae preferred to move along the vascular bundles; infected tissues lost the ability to transport water, leading to white head formation. By marking the edge of the white heads, this simple dyeing technique precisely reveals the extent of infection. Further, digital imaging allowed dried samples to be stored and reassessed later. CONCLUSIONS: The CFD detection technique served as a powerful tool for estimating disease severity by color, as it clearly revealed lesions in both the panicles and leaves. Combined with reliable methods for artificial inoculation and observation of infecting hyphae, this technique will advance the research and breeding of panicle blast-resistant rice.

Comparison of semiquantitative fluorescence imaging and PET tracer uptake in mesothelioma models as a monitoring system for growth and therapeutic effects.

INTRODUCTION: Various techniques are available for in vivo imaging, and precise understanding of their characteristics is essential for effective use of the imaging results. We established human mesothelioma cell lines expressing red fluorescent protein (RFP) and examined their fluorescence intensity and uptake of positron emission tomography (PET) tracer analogs to compare their characteristics and assess their usefulness in the evaluation of therapeutics. METHOD: A human mesothelioma cell line was stably transfected to express RFP. Fluorescence, cell number and protein amount were measured during cell growth and treatment with cytotoxic reagents. In in vivo experiments, RFP-expressing cells were injected subcutaneously or into the pleural cavity of nude mice, and fluorescence images were taken with or without pemetrexed treatment. The uptake of [(3)H]3'-deoxy-3'-fluorothymidine ([(3)H]FLT) and [(14)C]2-fluoro-2-deoxy-d-glucose ([(14)C]FDG) under treatment with the above reagents in vitro and in vivo were examined. RESULTS: Strong correlation was observed between fluorescence intensity and total cell number with or without cytotoxic treatment. The uptake of [(3)H]FLT and [(14)C]FDG decreased rapidly after the initiation of treatment with actinomycin D or cycloheximide. When treated with pemetrexed, the uptake of [(3)H]FLT temporarily increased. The cells formed subcutaneous and orthotopic tumors, with fluorescence intensity correlating with tumor volume. The correlation was sustained under pemetrexed treatment. The uptake of [(3)H]FLT in vivo increased significantly early after pemetrexed treatment. CONCLUSION: Fluorescence imaging could be used to semiquantitatively monitor tumor size, whereas PET could be used to monitor tumor response to therapeutic treatments, and especially, FLT might be a good marker of the response to anti-folate chemotherapeutics.