Stabilizing High-Temperature α-Li3PS4 by Rapidly Heating the Glass.

High-temperature metastable phases exhibit superior characteristics compared to those of thermodynamically stable phases at room temperature. Although optimization of the compositions and crystallizations from glasses contribute to the stabilization of metastable phases at room temperature, the stabilization of the high-temperature α-Li3PS4 phase is not yet reported. α-Li3PS4 was successfully stabilized at room temperature, instead of the middle-temperature ß-Li3PS4 phase, via rapid heating to crystallize the Li3PS4 glass. The obtained electrolyte exhibited a high ionic conductivity of >10-3 S cm-1 at room temperature. The crystallization of the glass via rapid heating overcame the thermodynamic limitations in the preparation of the metastable crystals. Further development of materials via nonequilibrium states should contribute to the design of high-performance materials.

Applicability Domain of Active Learning in Chemical Probe Identification: Convergence in Learning from Non-Specific Compounds and Decision Rule Clarification.

Efficient identification of chemical probes for the manipulation and understanding of biological systems demands specificity for target proteins. Computational means to optimize candidate compound selection for experimental selectivity evaluation are being sought. The active learning virtual screening method has demonstrated the ability to efficiently converge on predictive models with reduced datasets, though its applicability domain to probe identification has yet to be determined. In this article, we challenge active learning's ability to predict inhibitory bioactivity profiles of selective compounds when learning from chemogenomic features found in non-selective ligand-target pairs. Comparison of controls versus multiple molecule representations de-convolutes factors contributing to predictive capability. Experiments using the matrix metalloproteinase family demonstrate maximum probe bioactivity prediction achieved from only approximately 20% of non-probe bioactivity; this data volume is consistent with prior chemogenomic active learning studies despite the increased difficulty from chemical biology experimental settings used here. Feature weight analyses are combined with a custom visualization to unambiguously detail how active learning arrives at classification decisions, yielding clarified expectations for chemogenomic modeling. The results influence tactical decisions for computational probe design and discovery.

A Well-Defined Osmium-Cupin Complex: Hyperstable Artificial Osmium Peroxygenase.

Thermally stable TM1459 cupin superfamily protein from Thermotoga maritima was repurposed as an osmium (Os) peroxygenase by metal-substitution strategy employing the metal-binding promiscuity. This novel artificial metalloenzyme bears a datively bound Os ion supported by the 4-histidine motif. The well-defined Os center is responsible for not only the catalytic activity but also the thermodynamic stability of the protein folding, leading to the robust biocatalyst (Tm ≈ 120 °C). The spectroscopic analysis and atomic resolution X-ray crystal structures of Os-bound TM1459 revealed two types of donor sets to Os center with octahedral coordination geometry. One includes trans-dioxide, OH, and mer-three histidine imidazoles (O3N3 donor set), whereas another one has four histidine imidazoles plus OH and water molecule in a cis position (O2N4 donor set). The Os-bound TM1459 having the latter donor set (O2N4 donor set) was evaluated as a peroxygenase, which was able to catalyze cis-dihydroxylation of several alkenes efficiently. With the low catalyst loading (0.01% mol), up to 9100 turnover number was achieved for the dihydroxylation of 2-methoxy-6-vinyl-naphthalene (50 mM) using an equivalent of H2O2 as oxidant at 70 °C for 12 h. When octene isomers were dihydroxylated in a preparative scale for 5 h (2% mol cat.), the terminal alkene octene isomers was converted to the corresponding diols in a higher yield as compared with the internal alkenes. The result indicates that the protein scaffold can control the regioselectivity by the steric hindrance. This protein scaffold enhances the efficiency of the reaction by suppressing disproportionation of H2O2 on Os reaction center. Moreover, upon a simple site-directed mutagenesis, the catalytic activity was enhanced by about 3-fold, indicating that Os-TM1459 is evolvable nascent osmium peroxygenase.

Luminescence color change of [3,4-difluoro-2,6-bis(5-methyl-2-pyridyl)phenyl-κ3N,C1,N']cyanidoplatinum(II) by aggregation.

We have investigated the color and luminescence color changes of novel Pt(L)CN (L = 4,6-difluoro-1,3-di(2-(4-methyl)pyridyl)benzene) in solution and crystalline states that resulted from aggregation-induced emission (AIE). In the solution state, the AIE results from excimer and trimer formation in the excited states at high concentrations. We determined the emission lifetimes of the excimer and trimer to be τE = 1.72 µs and τT = 0.43 µs, respectively, and the emission quantum yields to be ϕE = 20% and ϕT = 12%, respectively, which are slightly smaller yet comparable to τM = 8.85 µs and ϕM = 67% of the monomeric species. In the crystalline state, the purple color of Pt(L)CN with no solvent of crystallization changes to red upon exposure to chloroform vapor, and the invisible emission turns to bright red emission. This phenomenon can be applied to inexpensive devices for the fast chloroform detection. The exposure of purple crystals to dichloromethane vapor causes a further redshift of the invisible emission and blue coloration, which suggests the capability of the discrimination of chloroform from dichloromethane.

Active learning effectively identifies a minimal set of maximally informative and asymptotically performant cytotoxic structure-activity patterns in NCI-60 cell lines.

The NCI-60 cancer cell line screening panel has provided insights for development of subtype-specific chemical therapies and repurposing. By extracting chemical structure and cytotoxicity patterns, virtual screening potentially complements the availability of high-throughput assay platforms and improves bioactive compound discovery rates by computational prefiltering of candidate compound libraries. Many groups report high prediction performances in computational models of NCI-60 data when using cross-validation or similar techniques, yet prospective therapy development in novel cancers may have little to no such data and further may not have the resources to perform hit identification using large compound libraries. In contrast to bulk screening and analysis, the active learning methodology has demonstrated how to identify compounds for screening in small batches and update computational models iteratively, leading to predictive models with a minimum number of compounds, and importantly clarifying data volumes at which limits in predictive ability are achieved. Here, in replicate per-cell line experiments using 50% of data (∼20 000 compounds) as the external prediction target, predictive limits are reproducibly demonstrated at the stage of systematic selection of 10-30% of the incorporable half. The pattern was consistent across all 60 cell lines. Limits of predictability are found to be correlated to the doubling times of cell lines and the number of cellular response discontinuities (activity cliffs) present per cell line. Organization into chemical scaffolds delineated degrees of predictive challenge. These results provide key insights for strategies in developing new inhibitors in existing cell lines or for future automated therapy selection in personalized oncotherapy.

Immunohistochemistry and K-ras sequence of pancreatic carcinosarcoma.

Herein is presented a case of carcinosarcoma of the pancreas in an 82-year-old woman, analyzed on immunohistochemistry and K-ras sequence. The tumor, which arose in the pancreas head, was removed on pancreaticoduodenectomy. The patient died, however, of disseminated intravascular coagulation syndrome from postoperative sepsis 13 days later. Microscopically, the tumor consisted of malignant epithelial (well-differentiated adenocarcinoma cells) and mesenchymal (spindle-shaped tumor cells) components. The adenocarcinoma cells had positive immunostaining for cytokeratin AE1/AE3, cytokeratin 7, epithelial membrane antigen (EMA), CEA and carbohydrate antigen 19-9 (CA 19-9), while focal staining of these proteins was observed in the sarcomatous cells. In contrast, the sarcomatous cells had diffuse immunostaining for vimentin, CD10 and p53, while these proteins were not expressed in the ductal adenocarcinoma cells. These findings support the dual characteristics of a carcinosarcoma. DNA sequencing of the present case indicated point mutations of K-ras in both codons 12 and 34 on exon 2. The latter mutation is likely to correlate with the sarcomatous characteristics of this tumor. The tumor cells had specific and diffuse positive staining for CD10 and p53, with features characteristic of rapid growth.

Effects of geldanamycin and thalidomide on the Th1/Th2 cytokine balance in mice subjected to operative trauma.

BACKGROUND: Persistence of postoperative immune dysfunction is a critical problem because it increases the risk of serious infectious complications. The mechanisms of the immune dysfunction that occur initially after non-thermal operative injury remain to be fully elucidated. METHODS: Two mouse models of operative trauma (simple laparotomy to represent minor operative injury and ileocecal resection to represent major operative injury) were used to define the characteristics of initial cytokine synthesis. Geldanamycin and thalidomide were independently added intraperitoneally before and after operative injury to examine the effect on postoperative immune dysfunction. Mice were sacrificed at scheduled times (3, 6, 12, and 24 h after operative injury) and TNF-alpha, IL-2, IL-4, and IL-10 were analyzed. Spleen was used for intracellular cytokines and RT-PCR. Sera were used for ELISA. RESULTS: Major operative injury caused an initial upregulation of IL-10 synthesis with delayed synthesis of TNF-alpha and IL-2. Minor operative injury caused an early induction of IL-2 synthesis preceded by an initial induction of IL-4 synthesis. GA caused a specific early upregulation of TNF-alpha mRNA expression and intracellular TNF-alpha synthesis. The GA and THD groups showed early serum IL-2 production with reduction of IL-10 mRNA expression and intracellular IL-10 synthesis in the early post-operative phase. CONCLUSIONS: Major and minor operative injury showed different Th1/Th2 cytokine patterns in the initial post-operative period. Geldanamycin and thalidomide improved the Th1/Th2 imbalance independently after major operative injury.

Omental pseudocyst.

Diagnostic image features of the omental cyst remain to be fully understood because of its rarity. We present here a case of omental cyst in a 29-year-old man involving several diagnostic image features. Contrasted computed tomography showed thin ring-like enhancement, and angiography revealed the feeding arteries that branched from the right gastroepiploic artery. The cyst was excised surgically, and the final pathological diagnosis was an omental pseudocyst.

STI571 (Glivec) induces cell death in the gastrointestinal stromal tumor cell line, GIST-T1, via endoplasmic reticulum stress response.

STI571 is a specific inhibitor of tyrosine kinases, such as BCR-ABL, platelet-derived growth factor receptor, and c-KIT, and has recently been approved for the treatment of chronic myeloid leukemia and gastrointestinal stromal tumors (GISTs). This study demonstrated that STI571 induces cell death in the gastrointestinal stromal tumor cell line, GIST-T1. In these cells, STI571 induced pro-caspase-12 or pro-caspase-7 cleavage and it affected caspase-3 activity and induced the endoplasmic reticulum (ER)-resident chaperone, glucose-regulated protein 78. The STI571-induced cell death was blocked by the protein synthesis inhibitor, cycloheximide. Together, these results suggest that STI571 induces cell death in GIST-T1 cells, at least in part, via the ER stress response.

STI571 (Glivec) suppresses the expression of vascular endothelial growth factor in the gastrointestinal stromal tumor cell line, GIST-T1.

AIM: To estimate whether STI571 inhibits the expression of vascular endothelial growth factor (VEGF) in the gastrointestinal stromal tumor (GIST) cells. METHODS: We used GIST cell line, GIST-T1. It has a heterogenic 57-bp deletion in exon 11 to produce a mutated c-KIT, which results in constitutive activation of c-KIT. Cells were treated with/without STI571 or stem cell factor (SCF). Transcription and expression of VEGF were determined by RT-PCR and flow cytometry or Western blotting, respectively. Activated c-KIT was estimated by immunoprecipitation analysis. Cell viability was determined by MTT assay. RESULTS: Activation of c-KIT was inhibited by STI571 treatment. VEGF was suppressed at both the transcriptional and translational levels in a temporal and dose-dependent manner by STI571. SCF upregulated the expression of VEGF and it was inhibited by STI571. STI571 also reduced the cell viability of the GIST-T1 cells, as determined by MTT assay. CONCLUSION: Activation of c-KIT in the GIST-T1 regulated the expression of VEGF and it was inhibited by STI571. STI571 has antitumor effects on the GIST cells with respect to not only the inhibition of cell growth, but also the suppression of VEGF expression.

A morphological study of the pacemaker cells of the aganglionic intestine in Hirschsprung's disease utilizing ls/ls model mice.

Hirschsprung's disease is a congenital aganglionic neural disorder of the segmental distal intestine characterized by unsettled pathogenesis. The relationship between Hirschsprung's disease and pacemaker cells (PMC), which almost corresponds to that of the interstitial cells of Cajal (ICC), was morphologically observed at the level of the intermuscular layer corresponding to Auerbach's plexus using ls/ls mice. These mice are an ideal model because of their large intestinal aganglionosis and gene abnormalities, which are similar to the human form of the disease. Immunostaining using anti-c-kit receptor antibody (ACK2), a marker of PMC, applied to whole-mount muscle-layer specimens, revealed the presence of c-kit immunopositive multipolar cells with many cytoplasmic processes in normal mice. For ls/ls mice, however, there were significantly fewer processes. The average number of processes per positive cell of 2.5 for the aganglionic large intestine was fewer than 3.5 for the large and small intestine of normal mice, indicating the inability to form connections between nerves and PMC in the aganglionic intestine. For normal mice with an Auerbach's plexus, the process attachment of ICC to the Auerbach's plexus was observed by scanning electron microscopy. However, for ls/ls mice no attachment to the intermuscular nerve without Auerbach's plexus was found, although transmission electron microscopy showed no difference in the cell structure and organelles of the c-kit immunopositive cells between the normal and ls/ls mice. These findings suggest that in the aganglionic intestine of Hirschsprung's disease, aplasia of enteric ganglia induces secondary disturbances during the normal development of intestinal PMC.

STI571 (Glivec) inhibits the interaction between c-KIT and heat shock protein 90 of the gastrointestinal stromal tumor cell line, GIST-T1.

The gastrointestinal stromal tumor cell line, GIST-T1, has a heterogenic 57-base pair deletion in exon 11 of the c-kit mutation, and the c-KIT protein in the GIST-T1 cells constitutively activated. We report that STI571 (Glivec; Novartis, Basel, Switzerland), a specific inhibitor of c-KIT, inhibits the clustering of c-KIT at the cell membrane of the GIST-T1 cells. Furthermore, STI571 prevents the interaction between c-KIT and the molecular chaperone, heat shock protein 90 (Hsp90). Geldanamycin, an inhibitor of Hsp90, also prevents interaction between c-KIT and Hsp90, and inhibits tyrosine phosphorylation of c-KIT. Our results indicate that c-KIT molecules are assembled on the cell surface of the GIST-T1 cells, and that the interaction between c-KIT and Hsp90 plays an important role in c-KIT activation.