Bonding of flowable resin composite restorations to class 1 occlusal cavities with and without cyclic load stress.

To examine the bonding of flowable resin composite restorations (F-restoration) to class 1 occlusal cavities with and without cyclic load stress, compared with that of a universal resin composite restoration (U-restoration). Two flowable composites and one universal composite (control) were applied with an adhesive system to 42 standardized class 1 occlusal cavities. The restored specimens were subjected to cyclic load stress and no stress modes. The microtensile bond strength (µ-TBS) of the dentin floor was measured. The U-restoration did not show pretesting failure. The F-restorations exhibited pretesting failure, regardless of the stress mode. The µ-TBS was not significantly different among the three restorations, regardless of the stress mode. The cyclic load stress did not influence the µ-TBS of the F-restorations; however, it significantly reduced µ-TBS in the U-restoration. The bonding reliability of the F-restorations was inferior to that of the U-restoration, for both stress modes.

Conformational analyses and MO studies of f152A1 and its analogues as potent protein kinase inhibitors.

f152A1 was isolated from a fermentation broth of Curvularia verruculosa and characterized as a potent inhibitor of TNFalpha transcription, with anti-inflammatory activity. f152A1 and several analogues displayed inhibitory activity against the MAP kinases ERK2 and MEK1 in in vitro kinase assays. Through SAR studies on f152A1 and analogues prepared via total synthesis, we have identified structural features that contribute to inhibitory activity. To rationalize these results and to aid in the discovery process, a combination of high temperature molecular dynamics and MOPAC AM1 semiempirical molecular orbital method studies was used in studies that yielded a postulated active conformation, M1(8). This active conformation M1(8) reflects a high degree of conformational similarity among f152A1 and its more potent analogues. In view of the highly reactive cis-enone moiety in the flexible 14-membered resorcylic acid lactone ring of f152A1, the chemical reactivities of the enone moieties in various analogues were assessed by molecular orbital calculations. The enone reactivity analyses suggested that these inhibitors were prone to Michael addition at the alpha,beta-unsaturated ketone moiety and might chemically react with cysteine residues in the ATP-binding site of MAP kinases. Reactivity of the cis-enone moiety and the M1(8) conformation make important contributions to the inhibitory activity of MAP kinases.

Microarray-based transcriptional profiling of renieramycin M and jorunnamycin C, isolated from Thai marine organisms.

Renieramycin M and jorunnamycin C, two isoquinolinequinone compounds differing only at the C-22 ester side chain, were evaluated for their cytotoxic effects on human colon (HCT116) and breast (MDA-MB-435) cancer cell lines. These two compounds displayed potent cancer cell growth inhibition, their IC(50) values reaching nanomolar order. To examine their effects on transcription, we carried out oligonucleotide microarray analysis with focus on the similarities and differences between the two compounds in terms of transcriptional profiles. We found that the down-regulation of PTPRK (protein tyrosine phosphatase receptor type K) can be considered as a biomarker responsive to the cytotoxic effects of this class of antitumor marine natural products.

Characterization of mRNA species that are associated with postsynaptic density fraction by gene chip microarray analysis.

We previously reported the partial identification by random sequencing of mRNA species that are associated with the postsynaptic density (PSD) fraction prepared from the rat forebrain [Tian et al., 1999. Mol. Brain Res. 72, 147-157]. We report here further characterization by gene chip analysis of the PSD fraction-associated mRNAs, which were prepared in the presence of RNase inhibitor. We found that mRNAs encoding various postsynaptic proteins, such as channels, receptors for neurotransmitters and neuromodulators, proteins involved in signaling, scaffold and adaptor proteins and cytoskeletal proteins, were highly concentrated in the PSD fraction, whereas those encoding housekeeping proteins, such as enzymes in the glycolytic pathway, were not. We extracted approximately 1900 mRNA species that were highly concentrated in the PSD fraction. mRNAs related to certain neuronal diseases were also enriched in the PSD fraction. We also constructed a cDNA library using the PSD fraction-associated mRNAs as templates, and identified 1152 randomly selected clones by sequencing. Our data suggested that the PSD fraction-associated mRNAs are a very useful resource, in which a number of as yet uncharacterized mRNAs are concentrated. Identification and functional characterization of them are essential for complete understanding of synaptic function.

Chronic intracerebroventricular administration of relaxin-3 increases body weight in rats.

Bolus-administered intracerebroventricular (ICV) relaxin-3 has been reported to increase feeding. In this study, to examine the role of relaxin-3 signaling in energy homeostasis, we studied the effects of chronically administered ICV relaxin-3 on body weight gain and locomotor activity in rats. Two groups of animals received vehicle or relaxin-3 at 600 pmol/head/day, delivered with Alzet osmotic minipumps. In animals receiving relaxin-3, food consumption and weight gain were statistically significantly higher than those in the vehicle group during the 14-day infusion. During the light phase on days 2 and 7 and the dark phase on days 3 and 8, there was no difference in locomotor activity between the two groups. Plasma concentrations of leptin and insulin in rats chronically injected with relaxin-3 were significantly higher than in the vehicle-injected controls. These results indicate that relaxin-3 up-regulates food intake, leading to an increase of body weight and that relaxin-3 antagonists might be candidate antiobesity agents.

Profiling novel sulfonamide antitumor agents with cell-based phenotypic screens and array-based gene expression analysis.

A series of small molecules from sulfonamide-focused libraries have been evaluated in these laboratories to discover novel antitumor agents. Cell-based screens using flow cytometric analysis revealed the presence of two distinct classes of cell cycle inhibitors in this series; one (including E7010 and ER-67865) arrested mitosis by preventing tubulin polymerization; and the other (including E7070 and ER-68487) caused a decrease in the S-phase fraction along with cell cycle perturbation in G1 and/or G2 via an unknown mechanism(s). To further characterize both classes of antitumor sulfonamides with respect to their effects on gene expression, we used oligonucleotide microarray analysis for representative compounds. Consistent with the phenotypic observations, essentially the same transcription profiles were found between E7010 and ER-67865 and also between E7070 and ER-68487. However, there was very little overlap between genes affected by E7010 and E7070. As a characteristic expression change for microtubule-depolymerizing agents, the down-regulation of alpha-tubulin transcripts was evident in both E7010- and ER-67865-treated cells. On the other hand, E7070 and ER-68487 repressed significantly the expression of a variety of genes involved in metabolic processes, cell cycle progression, immune response, and signal transduction. Of the compounds examined, E7010 and E7070 have progressed to clinical trials, demonstrating some objective responses in the Phase I setting. Described herein is profiling of novel anticancer drug candidates from the sulfonamide class based on phenotypic screens and gene expression analysis. This includes a translational research that may suggest potentially useful markers for pharmacodynamic drug assessment in clinic.