Biomedical subjects

Ryuji Hayashi

Publications and source records attributed to Ryuji Hayashi.

10 recordsLinked to original sources

PubMed2026

Comprehensive Genomic Profiling Timeliness Beyond Laboratory Turnaround Time: A Patient-Facing Pathway Analysis.

AIM: We evaluated the timeliness of the patient-facing comprehensive genomic profiling (CGP) pathway by separating laboratory and post-laboratory intervals within an expert panel-mediated process, using direct disclosure of results to patients as the endpoint. METHODS: This single-center retrospective study included adult CGP test episodes performed under government-funded cancer genomic medicine at a Japanese university hospital between October 2019 and November 2025. The primary outcome was patient-centered turnaround time (TAT), defined as the interval from informed consent to direct disclosure of the CGP result to the patient. Laboratory TAT and pathway intervals were summarized descriptively, and laboratory TAT was compared across assays. RESULTS: Among 882 CGP test episodes, median laboratory TAT was 14 days (interquartile range [IQR], 12-16) among 871 evaluable episodes. Among 828 evaluable episodes, median patient-centered TAT was 41 days (IQR 35-45). The laboratory analysis retained observed long intervals, including a maximum of 72 days; no episode was excluded solely because laboratory TAT exceeded 56 days. These findings indicate that laboratory TAT was only one component of the longer consent-to-disclosure pathway. CONCLUSION: In this routine-care CGP pathway, patient-facing timeliness depended on the full process from consent to direct patient disclosure. Patient-centered TAT should be monitored alongside laboratory TAT as a care-delivery measure.

comprehensive genomic profiling↗

PubMed2006

Isoproterenol suppresses cytokine-induced RANTES secretion in human lung epithelial cells through the inhibition of c-jun N-terminal kinase pathway.

It has been reported that beta2-agonists may potentially exert some anti-inflammatory action in addition to bronchodilation that may contribute to their beneficial effects on asthma control. Bronchial epithelial cells are well known to respond to a range of stimuli by producing various biologically active mediators that can influence airway inflammation. RANTES (regulated on activation, normal T cells expressed and secreted) plays an important role in the pathophysiology of airway inflammation of asthmatics through its chemotactic activity for eosinophils. In this study, the authors investigated whether cytokine-induced RANTES release from BEAS-2B human bronchial epithelial cells could be modulated by beta-agonist isoproterenol (ISO). The possible involvement of c-jun N-terminal kinase (JNK) pathway was also studied. Combination of tumor necrosis factor-alpha and interleukin-1beta (cytokine mix) increased RANTES release from BEAS-2B cells and stimulated JNK activity. Similar to JNK inhibitor SP600125, ISO inhibited not only the production of RANTES but also the activation of JNK pathway in cytokine mix-stimulated BEAS-2B cells. The effect of ISO was mediated by the beta2-adrenoceptor, since it was blocked by ICI 118,551, a selective beta2-receptor antagonist, but not by atenolol, a selective beta1-receptor antagonist. Adenylyl cyclase activator forskolin reproduced the effects of ISO. Isoproterenol was found to inhibit the release of RANTES from the human bronchial epithelial cells, at least in part, through the inhibition of JNK signaling pathway.

Cell Line↗

PubMed2006

Ionizing radiation suppresses FAP-1 mRNA level in A549 cells via p53 activation.

Ionizing radiation (IR) is known to upregulate cell surface Fas through p53 activation in various cells. However, the signaling pathway intermediating between p53 activation and cell surface Fas upregulation remains to be elucidated. Recently, Fas-associated phosphatase-1 (FAP-1) has been reported to associate with Fas and inhibit cell surface Fas expression. We evaluated the expression of FAP-1 mRNA following IR in A549 cells. Ionizing radiation inhibited the expression of FAP-1 mRNA. Pretreatment with p53 inhibitor pifithrin alpha cancelled the IR-induced downregulation of FAP-1 mRNA. These results suggest that IR-induced p53 activation may upregulate cell surface Fas via the down-modulation of FAP-1.

Benzothiazoles↗

PubMed2006

Atom transfer cyclization catalyzed by InCl3 via halogen activation.

[reaction: see text] Indium trichloride was found to be an efficient catalyst for the cyclization of allylic halides and alkynes with atom transfer in methylene chloride. Mechanistic evidence supports a cationic reaction pathway with Lewis acid activation of the allylic halogen. Concomitant nucleophilic attack by the alkyne and trapping with halide led to atom transfer cyclization products. Depending on alkyne substitution, a bromine atom was transferred from the substrate or a chlorine atom was transferred from the solvent.

Alkynes↗

PubMed2006

NF-kappaB and activator protein 1 response elements and the role of histone modifications in IL-1beta-induced TGF-beta1 gene transcription.

Abnormal expression of TGF-beta1 is believed to play an important role in the pathogenesis of a number of chronic inflammatory and immune lung diseases, including asthma, chronic obstructive pulmonary disease, and pulmonary fibrosis. Gene activation in eukaryotes requires coordinated use of specific cell signals, chromatin modifications, and chromatin remodeling. We studied the roles of the ubiquitous inflammatory transcription factors, NF-kappaB and AP-1, in activation of the TGF-beta1 gene and histone acetylation at the TGF-beta1 promoter. IL-1beta-induced TGF-beta1 protein secretion and mRNA expression were prevented by actinomycin D and were attenuated by the inhibitor of kappaB kinase 2 inhibitor AS602868 and the JNK inhibitor SP600125, suggesting a degree of transcriptional regulation mediated by the NF-kappaB and AP-1 pathways. We demonstrated that IL-1beta activated the p65 subunit of NF-kappaB and the c-Jun subunit of AP-1. Using chromatin immunoprecipitation assays, we observed a sequential recruitment of p65 and c-Jun, accompanying ordered elevation of the levels of histone H4 and H3 acetylation and recruitment of RNA polymerase II at distinct regions in the native TGF-beta1 promoter. The specific NF-kappaB and AP-1 binding sites in the TGF-beta1 promoter were confirmed by an ELISA-based binding assay, and evidence for histone hyperacetylation in TGF-beta1 induction was supported by the observation that the histone deacetylase inhibitor trichostatin A enhanced basal and IL-1beta-induced TGF-beta1 mRNA expression. Our results suggest that IL-1beta-stimulated transcription of TGF-beta1 is temporally regulated by NF-kappaB and AP-1 and involves histone hyperacetylation at distinct promoter sites.

Acetylation↗

PubMed2005

Doxorubicin induces expression of multidrug resistance-associated protein 1 in human small cell lung cancer cell lines by the c-jun N-terminal kinase pathway.

Multidrug resistance (MDR) is a major impediment to successful chemotherapy for lung cancer. Overexpression of multidrug resistance-associated protein 1 (MRP1) appears to be involved in MDR development in lung cancer cells. A number of chemotherapeutic agents including doxorubicin (DOX) were reported to induce MRP1 expression in human lung cancer cells. In our study, we investigated the mechanism by which DOX induces MRP1 expression in human small cell lung cancer (SCLC) cell lines, GLC4 and NCI-H82. These cells expressed MRP1 protein at low levels and were sensitive to DOX. Doxorubicin at 50 nM induced a marked increase in MRP1 expression in 24 hr, and stimulated c-jun N-terminal kinase (JNK) activity. Treatment with a JNK inhibitor, SP600125, significantly inhibited MRP1 induction. Furthermore, transfection with JNK1 and JNK2 antisense oligonucleotides markedly inhibited DOX-induced MRP1 expression. Chromatin immunoprecipitation assays revealed an enhanced recruitment of phosphorylated c-jun to the MRP1 promoter containing the AP-1 site upon DOX stimulation, which was inhibited by pretreatment with SP600125. Surprisingly, GLC4 cells exposed to DOX for 24 hr maintained increased MRP1 expression and resistance to DOX for at least 3 weeks. Pretreatment with SP600125 before DOX stimulation blocked the appearance of the MDR phenotype as well as MRP1 induction in GLC4 cells. These findings suggest that JNK activation may play an essential role for the induction of MRP1 protein in human SCLC cells by chemotherapeutic agents and that combined treatment of a JNK inhibitor with anticancer drugs may prevent the development of MDR by the abrogation of MRP1 induction.

Antibiotics, Antineoplastic↗

PubMed2004

Effects of glucocorticoids on gene transcription.

Glucocorticoids bind to and activate a cytoplasmic glucocorticoid receptor. The activated glucocorticoid receptor translocates into the nucleus and binds to specific response elements in the promoter regions of anti-inflammatory genes such as lipocortin-1 and secretory leukocyte protease inhibitor (SLPI). However, the major anti-inflammatory effects of glucocorticoids appear to be due largely to interaction between the activated glucocorticoid receptor and transcription factors, notably nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1), that mediate the expression of inflammatory genes. NF-kappaB switches on inflammatory genes via a process involving recruitment of transcriptional co-activator proteins and changes in chromatin modifications such as histone acetylation. This process must occur in the correct temporal manner to allow for effective inflammatory gene expression to occur. The interactions between NF-kappaB and the glucocorticoid receptor result in differing effects on histone modifications and chromatin remodelling. Drugs that enhance glucocorticoid receptor nuclear translocation (long acting beta-agonists) and GR-associated histone deacetylases activity (theophylline) have been shown to be effective add-on therapies. In addition, dissociated glucocorticoids that target NF-kappaB preferentially have also been successful in the treatment of allergic disease.

Animals↗

PubMed2002

Ultrasonographically assessed carotid atherosclerosis in Japanese type 2 diabetic patients: Role of nonesterified fatty acids.

The aim of the present study was to evaluate the association of carotid atherosclerosis (intimal-medial thickness [IMT] in plaque-free segments and carotid stenosis in plaque segments) with serum nonesterified fatty acids (NEFA) in diabetic and nondiabetic patients. Fifty-one nonobese nonhypertensive Japanese type 2 diabetic patients aged 38 to 83 years (60.0 +/- 1.5 years, mean +/- SEM) and 23 age-matched (60.4 +/- 2.2 years, P =.439; range, 36 to 74 years) and sex-matched nondiabetic subjects were examined. The duration of diabetes was 9.6 +/- 1.0 years. Body mass index (BMI), blood pressure (systolic pressure, diastolic pressure), glycosylated hemoglobin (HbA(1c)), and fasting concentrations of plasma glucose, serum lipids (triglycerides, total, and high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol) and serum NEFA were measured. Using high-resolution B-mode ultrasound scan, we measured IMT in plaque-free segments of bilateral common carotid arteries, and the mean of IMT in 2 vessels was used for the analysis. Furthermore, we calculated the degree of stenosis in plaque segments of bilateral common carotid arteries. The degree of carotid stenosis was expressed as a percentage ratio between the area of plaque and that of the lumen using the formula (Lumen Area - Residual Lumen) x 100. Both the areas were automatically measured by the system on a frozen transverse scanning plane at the site of maximal narrowing. When 2 or more plaques were present in the vessel, only that causing the greatest degree of stenosis was considered for analysis. Univariate regression analyses showed that mean IMT in plaque-free segments was positively correlated with age (r =.498, P =.0004) and NEFA (r =.354, P =.0188) in type 2 diabetic patients. The degree of stenosis was positively correlated to age (r =.422, P =.0028), duration of diabetes (r =.313, P =.0268) and NEFA (r =.540, P =.0003) in diabetic patients. Other variables, including BMI and lipid profile, were not associated both with mean IMT in plaque-free segments and the degree of stenosis in plaque segments in our diabetic patients. Multiple regression analyses showed that mean IMT in plaque-free segments was independently associated with age (P =.0003, F = 15.2), which explained 26.1% of the variability of IMT in our diabetic patients. The degree of stenosis was independently predicted by NEFA (P =.0047, F = 8.9), which explained 17.2% of the variability of the carotid stenosis in our diabetic patients. In contrast, mean IMT in plaque-free segments was positively correlated to age in nondiabetic subjects (r =.450, P =.0347). There was, however, no relationship between the degree of stenosis and the variables, including age and NEFA, in nondiabetic subjects. These results indicate that the factors contributing to IMT in plaque-free segments and the degree of carotid stenosis in plaque segments are different in nonobese nonhypertensive Japanese type 2 diabetic patients. IMT in plaque-free segments was independently associated with age both in nondiabetic and diabetic subjects, whereas the serum NEFA level independently predicted the degree of stenosis in plaque segments in our diabetic patients, while not in nondiabetic subjects. Thus, NEFA is considered to be one of the new risk factors responsible for the progression of carotid atherosclerosis in nonobese nonhypertensive Japanese type 2 diabetic patients.

Adult↗

PubMed2002

Inhibition of proteasome activity is involved in cobalt-induced apoptosis of human alveolar macrophages.

Inhalation of particulate cobalt has been known to induce interstitial lung disease. There is growing evidence that apoptosis plays a crucial role in physiological and pathological settings and that the ubiquitin-proteasome system is involved in the regulation of apoptosis. Cadmium, the same transitional heavy metal as cobalt, has been reported to accumulate ubiquitinated proteins in neuronal cells. On the basis of these findings, we hypothesized that cobalt would induce apoptosis in the lung by disturbance of the ubiquitin-proteasome pathway. To evaluate this, we exposed U-937 cells and human alveolar macrophages (AMs) to cobalt chloride (CoCl(2)) and examined their apoptosis by DNA fragmentation assay, 4',6-diamidino-2'-phenylindol dihydrochloride staining, and Western blot analysis. CoCl(2) induced apoptosis and accumulated ubiquitinated proteins. Exposure to CoCl(2) inhibited proteasome activity in U-937 cells. Cobalt-induced apoptosis was mediated via mitochondrial pathway because CoCl(2) released cytochrome c from mitochondria. These results suggest that cobalt-induced apoptosis of AMs may be one of the mechanisms for cobalt-induced lung injury and that the accumulation of ubiquitinated proteins might be involved in this apoptotic process.

Antimutagenic Agents↗

PubMed2002

Hydrogen peroxide induces upregulation of Fas in human airway epithelial cells via the activation of PARP-p53 pathway.

Fas mediates apoptosis following binding with Fas ligand. Fas is expressed in human airway epithelial cells and has a critical role in the pathophysiology of various pulmonary disorders. Hydrogen peroxide (H(2)O(2)) is an important mediator of airway epithelial injury. In this context, we hypothesized that H(2)O(2) would increase the expression of cell surface Fas in human airway epithelial cells. To test this hypothesis, the modulation of Fas expression with H(2)O(2) was assessed in normal human bronchial epithelial cells and A549 cells. The majority of Fas was cytoplasmic in both cell types without any stimulation. Hydrogen peroxide significantly increased Fas in the plasma membrane fraction, while decreasing Fas in the cytoplasmic fraction. Incubation with an agonistic antibody for Fas induced apoptosis in H(2)O(2)-treated cells in proportion to the level of surface Fas expression on those cells. Inhibitors of poly(ADP-ribose) polymerase abrogated the H(2)O(2)-induced Fas translocation to the plasma membrane and p53 activation. Expression of dominant-negative p53 also inhibited the Fas translocation induced by H(2)O(2) in A549 cells. These results indicate that H(2)O(2) induces Fas upregulation by promoting cytoplasmic transport of Fas to the cell surface in human airway epithelial cells, and that the activation of the poly(ADP-ribose) polymerase-p53 pathway may be involved in this mechanism.

Apoptosis↗