A Safe, Simple, and Facile Staining Method Using Polysiloxanes for High-Contrast Visualization of Gelator Aggregates by Transmission Electron Microscopy

The staining of TEM samples using Si atoms was investigated using aggregates of loose gels formed by twelve structurally different gelators in several solvents. Thirteen commercially available siloxanes were used as stains. TEM images of non-stained and OsO4-stained samples of molecular aggregates formed by the dodecamethylenediamide of N-methacryloyl-oxyethylaminocarbonyl-L-isoleucine in 1-propanol were poorly defined and low-contrast. However, the image of a methacryloyloxypropyl-terminated polydimethylsiloxane (S1)-stained sample was characterized by very clear bundles of fine fibers. The staining effect was explained by the wrapping of fibers, the stabilizing of the individual fibers, and reinforcing by S1. An S1 concentration of more than 5 mgmL(-1) was found to be necessary for satisfactory contrast. S1 was successfully applied to the observation of aggregates of eleven other gelators. S1 worked universally as an aggregate stain regardless of the gelator or solvent polarity. The staining effect was observed for other siloxanes. This effect was found to depend on the molecular weight of the siloxane (>1,000) rather than the kind of siloxane employed. Energy-dispersive X-ray spectroscopy indicated that the molecules of S1 gather on the surface of the fibers during drying, wrapping them. The results indicate that the present staining method guarantees reproducibility and universality.ArticleBULLETIN OF THE CHEMICAL SOCIETY OF JAPAN.91(7):1176-1185(2018)journal articl

Increase of Pro-opiomelanocortin mRNA Prior to Tyrosinase, Tyrosinase-Related Protein 1, Dopachrome Tautomerase, Pmel-17/gp100, and P-Protein mRNA in Human Skin After Ultraviolet B Irradiation

In ultraviolet-induced tanning, the protein levels of various gene products critical for pigmentation (including tyrosinase and tyrosinase-related protein-1) are increased in response to ultraviolet B irradiation, but changes in mRNA levels of these factors have not been investigated in vivo. We have established an in situ hybridization technique to investigate mRNA levels of pro-opiomelanocortin, tyrosinase, tyrosinase-related protein-1, dopachrome tautomerase, P-protein, Pmel-17/gp100, and microphthalmia-associated transcription factor, and have analyzed the changes in mRNA levels in the ultraviolet B-exposed skin in vivo. The right or left forearm of each volunteer was irradiated with ultraviolet B, and skin biopsies were obtained at 2 and 5 d postirradiation. mRNA level of pro- opiomelanocortin was increased 2 d after ultraviolet B irradiation, and returned to a near-basal level after 5 d, whereas the mRNA levels of tyrosinase, tyrosinase-related protein-1, dopachrome tautomerase, P-protein, and Pmel-17/gp100 showed some or no increase at 2 d, but were significantly increased 5 d after ultraviolet B irradiation. Microphthalmia-associated transcription factor mRNA was slightly increased on days 2 and 5 after ultraviolet B irradiation. Our results suggest that the mechanism of the tanning response of human skin may involve the transcriptional regulation of certain pigmentary genes, and that pro-opiomelanocortin-derived melanocortins such as α-melanocyte-stimulating hormone and adrenocorticotropic hormone may play a part in regulating these genes in vivo

Interaction between caesium iodide particles and gaseous boric acid in a flowing system through a thermal gradient tube (1030 K–450 K) and analysis with ASTEC/SOPHAEROS

International audienceThe present work aimed at studying the interaction between caesium iodide particles and gaseous boric acidthrough a Thermal Gradient Tube (TGT) from 1023 K to 453 K under Ar/H2O. Particles size range of transportedparticles was measured by ELPI and the fraction of gaseous compounds by ICP-MS and UV–visible spectroscopy.Reaction between the two compounds was deduced by measuring a significant fraction of gaseous iodine at theoutlet of the facility, representing more than 80% of the total iodine sampled at the outlet. The reaction rate wasshown to be lower when the flow rate inside the facility was increased. Analysis with SOPHAEROS module ofASTEC code was performed. The ASTEC fission products models allowed performing the evaluation of theexperimentally observed results for the analysis of the transport of pure compounds. However, the heterogeneousinteraction between the caesium iodide particles and the gaseous boric acid was not reproduced, as the modelsare not taken into account in the version v2.1_1_6 of the ASTEC/SOPHAEROS module. The next step would be toidentify the mechanism of the reaction by comparing the results with other studies and to determine the reactionrates. Then, a first development in SOPHAEROS would be to implement such phenomena

Inhibition of NF-κB and Akt pathways by an antibody-avidin fusion protein sensitizes malignant B-cells to cisplatin-induced apoptosis

Multiple myeloma (MM) is an incurable disease of malignant plasma cells. Recent therapeutic advancements have resulted in improved response rates, however, there is no improvement in overall survival, therefore, new therapeutics are needed. Since the transferrin receptor is upregulated on the surface of MM cells, we previously developed an antibody fusion protein consisting of an IgG3 specific for the human transferrin receptor 1 (TfR1, CD71) genetically fused to avidin at its carboxy-terminus (ch128.1Av). We have previously shown that ch128.1Av exhibits intrinsic cytotoxicity against certain malignant B-cells by disrupting the cycling of the TfR and decreasing TfR cell surface expression resulting in lethal iron starvation. In addition, ch128.1Av can sensitize malignant cells to apoptosis induced by gambogic acid, a herbal drug used in Chinese medicine. In this study, we hypothesized that ch128.1Av may also sensitize drug-resistant malignant B-cells to chemotherapeutic agents by inhibiting key survival pathways. In this study we show that ch128.1Av sensitizes malignant B-cells to apoptosis induced by cisplatin (CDDP). The sensitization by ch128.1Av resulted in the inhibition of the constitutively activated Akt and NF-κB survival/antiapoptotic pathways and downstream decreased expression of antiapoptotic gene products such as BclxL and survivin. The direct role of the inhibition of the Akt and NF-κB pathways by ch128.1Av in CDDP-mediated cytotoxicity was demonstrated by the use of specific chemical inhibitors and siRNA which mimicked the effects of ch128.1Av. Overall, this study provides evidence of the therapeutic potential of ch128.1Av as a chemo-sensitizing agent in drug-resistant tumor cells.Fil: Suzuki, Eriko. Keio University; JapónFil: Daniels, Tracy R.. University of California at Los Angeles; Estados UnidosFil: Helguera, Gustavo Fernando. University of California at Los Angeles; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Penichet, Manuel L.. University of California at Los Angeles; Estados UnidosFil: Umezawa, Kazuo. Keio University; JapónFil: Bonavida, Benjamín. University of California at Los Angeles; Estados Unido

A Case of Focal Choroidal Excavation Development Associated with Multiple Evanescent White Dot Syndrome

Focal choroidal excavation (FCE) is described as an excavated lesion of the choroid that can be detected by optical coherence tomography (OCT). While the exact pathogenesis of FCE remains unclear, it has been proposed in some cases that there is an association with the inflammation in the outer retina. We present a case of FCE development that was detected by spectral domain OCT (SD-OCT) and found to be associated with multiple evanescent white dot syndrome (MEWDS). A 40-year-old Japanese woman was diagnosed with MEWDS based on multiple white dots observed from the posterior pole to the midperiphery, along with yellow granularity in the fovea. SD-OCT revealed separation between the retinal pigment epithelium (RPE) and Bruch’s membrane (BM) and discontinuations of the ellipsoid zone, RPE, and BM. At 4 weeks after onset, several of the white dots disappeared, the yellow granularity in the fovea became small, and we detected nonconforming choroidal excavation under the central fovea. The choroidal excavation gradually deepened and changed to a conforming pattern. These findings suggest that the degree of the impairment caused by inflammation and the plasticity of the BM and RPE complex may be associated with different types of acquired FCE

Impact of renal dysfunction on the choice of diagnostic imaging, treatment strategy, and outcomes in patients with stable angina

We investigated the interaction between the prognostic impact of a decrease in eGFR and the choice of initial diagnostic imaging modality for coronary artery disease. Out of 2878 patients who enrolled in the J-COMPASS study, 2780 patients underwent single photon emission computed tomography (SPECT), coronary computed tomography (CT) angiography, or coronary angiography (CAG) as an initial diagnostic test. After excluding patients with routine hemodialysis or lacked serum creatinine levels, 2096 patients in the non-decreased eGFR group (eGFR ≥ 60 ml/min/1.73 m²) and 557 patients in the decreased eGFR group (eGFR < 60 ml/min/1.73 m²) were analyzed in this study. Major adverse cardiac events, including death, myocardial infarction, heart failure hospitalization, and late revascularization, were followed, with a median follow-up duration of 472 days. SPECT or CAG was preferable to CT in patients in the decreased eGFR group (p < 0.0001 and p = 0.0024, respectively). There was a marginally significant interaction between the prognostic impact of a decrease in eGFR and the choice of diagnostic imaging modality (interaction-p = 0.056). A decrease in eGFR was not associated with a poor outcome in patients who underwent CT, while a decrease in eGFR was associated with poor outcomes in patients who underwent SPECT or CAG. In conclusion, the prognostic impact of a decrease in eGFR tended to be different among the initial imaging modalities

Association of coronary revascularisation after physician-referred non-invasive diagnostic imaging tests with outcomes in patients with suspected coronary artery disease: a post hoc subgroup analysis

Objective: We aimed to evaluate the association of the prognostic impact of coronary revascularisation with physician-referred non-invasive diagnostic imaging tests (single photon emission CT (SPECT) vs coronary CT angiography) for coronary artery disease. Design: A post hoc analysis of a subgroup from the patient cohort recruited for the Japanese Coronary-Angiography or Myocardial Imaging for Angina Pectoris Study. Setting: Multiple centres in Japan. Participants: From the data of 2780 patients with stable angina, enrolled prospectively between January 2006 and March 2008 in Japan, who had undergone physician-referred non-invasive imaging tests, 1205 patients with SPECT as an initial strategy and 625 with CT as an initial strategy were analysed. We assessed the effect of revascularisation (within 90 days) in each diagnostic imaging stratum and the interaction between the two strata. Primary and secondary outcome measures: Major adverse cardiac events (MACEs), including death, myocardial infarction, hospitalisation for heart failure and late revascularisation, were followed up for 1 year. The χ2 test, Student’s t-test, Kaplan-Meier analysis, log-rank test and multivariable Cox proportional hazard model were used in data analysis. Results: A total of 210 (17.4%) patients in the SPECT stratum and 149 (23.8%) in the CT stratum underwent revascularisation. Although in each stratum, the cumulative 1 year incidence of MACEs was significantly higher in patients who underwent revascularisation than in those who did not (SPECT stratum: 9.1 vs 1.2%, log-rank p<0.0001; CT stratum: 6.1 vs 0.8%, log-rank p=0.0001), there was no interaction between the risk of revascularisation and the imaging strata (SPECT stratum: adjusted HR (95% CI), 4.25 (1.86–9.72); CT stratum: 4.13 (1.16–14.73); interaction: p=0.97). Conclusion: The association of revascularisation with the outcomes of patients with suspected coronary artery disease was not different between SPECT-first and CT-first strategies in a physician-referred fashion