Settling behavior of fillers in thermosetting epoxy casting resins during cure

Using a theory based on a modified Stokes' law equation, the settling behavior of fillers was investigated (glass beads and silica powder) in thermosetting epoxy casting resins during cure. In this study a suspension (a thermosetting epoxy casting resin) containing a large amount of filler particles is assumed to be a homogeneous fluid, and the settling phenomena are treated such that one or more particles of the filler settle into the homogeneous fluid under gravity without interference from other particles. The viscosity increase of the fluid during cure is taken into consideration. The experimental results agree well with the theoretical predictions when the settling distances are small and the particle size distribution is narrow. When these conditions are not satisfied, various effects are observed such as convection, filtering, combination, bottom effect, and a broad particle size distribution. In addition, the formation of a compression zone and of a compaction zone are clearly observed.     

Investigation of genetic alterations associated with the grade of astrocytic tumor by comparative genomic hybridization

A method of induction of multiple DNA-protein and protein-protein cross-links in chromatin of isolated nuclei has been developed. The cross-linking is brought about by mutual effect of fluorochrome ethidium bromide (EtBr) and irradiation with blue light. Electron microscopic analysis of nuclei isolated in solutions with various concentrations of divalent cations, stained with EtBr and irradiated with blue light, has demonstrated that the method leads to a selective stabilization of macromolecular complexes of chromatin against various treatments causing decompactization of native chromatin. Besides that, the stabilization of nucleoli and clusters of interchromatin granules takes place. On the other hand, the same treatment does not stabilize elementary chromatin fibers (about 30 nm thick), and the transition to the nucleosomal fiber occurs after extraction of histone H1 with 0.6 M NaCl. Electrophoretic analysis of proteins from control and irradiated nuclei shows the basic role of non-histone proteins in the stabilization. The data are discussed based on the assumption on the availability of some "intermediate" levels of chromatin compaction between 30 nm chromatin fiber and mitotic chromosome.     

Regulation of GluA1 AMPA Receptor Through PKC Phosphorylation Induced by Free Fatty Acid Derivative HUHS2002

The present study investigated the effect of 4-[4-(Z)-hept-1-enyl-phenoxy] butyric acid (HUHS2002), a newly synthesized free fatty acid derivative, on α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor responses. HUHS2002 potentiated currents through GluA1 AMPA receptors expressed in Xenopus oocytes in a bell-shaped concentration (1 nM–1 μM)-dependent manner, the maximum reaching nearly 140 % of original amplitude at 100 nM. The potentiation was significantly inhibited by GF109203X, an inhibitor of protein kinase C (PKC), but not KN-93, an inhibitor of Ca²⁺/calmodulin-dependent protein kinase II (CaMKII). HUHS2002 had no potentiating effect on currents through mutant GluA1 AMPA receptors with replacement of Ser831, a PKC/CaMKII phosphorylation site, by Ala. In the in situ PKC assay using rat PC-12 cells, HUHS2002 significantly enhanced PKC activity, that is suppressed by GF109203X. Overall, the results of the present study show that HUHS2002 potentiates GluA1 AMPA receptor responses by activating PKC and phosphorylating the receptors at Ser831, regardless of CaMKII activation and phosphorylation.     

Differential expression of multidrug resistance (mdr) and canalicular multispecific organic anion transporter (cMOAT) genes following extrahepatic biliary obstruction in rats

CD4+ TCRalphabeta+ T cells from the colonic lamina propria of athymic (nude) mice were adoptively transferred into histocompatible (SCID) mice homozygous for the autosomal recessive mutation scid (severe combined immunodeficiency). Transfer of these extrathymic CD4+ T cells into SCID mice induced a pancolitis in the adoptive host. The histopathology of this inflammatory response was restricted to the colon and closely resembled human UC. CD4+ T cells infiltrating the colonic lamina propria of diseased SCID mice displayed the surface phenotype of mucosa-seeking memory/effector cells, expressed interferon-gamma (IFN-gamma), and lysed targets in a Fas (CD95)/FasL-dependent pathway. Massive accumulation of oligoclonal CD4+ T cells of athymic origin with the phenotype of Th1 memory/effector T cells in the colonic lamina propria of a histocompatible, immunodeficient host elicits a pancolitis that morphologically mimics human UC.     

Methamphetamine modulates ACh-evoked currents in Xenopus occytes expressing the rat alpha7 receptors

Growth/differentiation factor 5 (GDF5), a novel member of the transforming growth factor beta superfamily, promotes the survival of dopaminergic neurones in vitro. We present here the first evidence for a neuroprotective action of GDF5 in vivo. We investigated the effects of intracerebral administration of GDF5 on a rat model of Parkinson's disease. GDF5 was administered just above the substantia nigra and into the lateral ventricle immediately before ipsilateral injection of 6-hydroxydopamine into the medial forebrain bundle. GDF5 prevented the development of amphetamine-induced rotations and preserved the integrity of striatal dopaminergic nerve terminals, as measured by positron emission tomography. Post-mortem studies showed that GDF5 spared dopamine levels in the striatum and tyrosine hydroxylase positive neurones in the midbrain. This study suggests that GDF5 has potential for the treatment of Parkinson's disease.     

Simulation Analysis Using Multi-Agent Systems for Social Norms

With the existence of the social customs or norms, Naylor demonstrates a possibility of stable long-run equilibria of support for a strike in a labor market, and this implies that at least some individuals will behave cooperatively and hence the prisoners’ dilemma could be escaped. In this paper, using an agent-based simulation model in which artificial adaptive agents have mechanisms of decision making and learning based on neural networks and genetic algorithms, we compare the results of our simulation analysis with that of the mathematical model by Naylor. In particular, while Naylor’s model is based on rationality as it relates to individual utility maximization, agents behave adaptively in our agent-based simulation model; agents make decisions by trial and error, and they learn from experiences to make better decisions.      

A novel ALL-L3 cell line, BALM-16, lacking expression of immunoglobulin chains derived from a patient with hypercalcemia

OBJECTIVE: The purpose of the study is to evaluate whether a posterior capsulectomy combined with anterior vitrectomy is a necessity in pediatric cataract. DESIGN: The incidence of posterior capsule opacification, the need for additional surgical interventions, and the influence of a primary posterior capsulectomy after cataract surgery in children were evaluated. The analysis was carried out by studying patients' records retrospectively or after prospective follow-up. PARTICIPANTS: In 94 eyes (69 aphakic and 25 pseudophakic), the medical records were studied retrospectively. Twenty-eight eyes (18 aphakic and 10 pseudophakic) were observed prospectively during 1 year after surgery. In 20 eyes (6 aphakic and 14 pseudophakic) of 10 patients with bilateral cataract, a prospective comparison between the 2 eyes of the same patient also was carried out. INTERVENTION: Cataract surgery through the limbus with or without a primary posterior capsulectomy was performed in 114 eyes (43 of these received a posterior chamber intraocular lens [IOL] and 71 remained aphakic). In 28 eyes, the surgery was carried out by way of the pars plana (6 eyes received an anterior chamber IOL and 22 remained aphakic). MAIN OUTCOME MEASURES: Incidence of posterior capsule opacification, the need for secondary surgical intervention, and visual acuity were measured. RESULTS: Opacification of the posterior capsule is observed in all children's eyes when a primary posterior capsulectomy (combined with an anterior vitrectomy) was not carried out. Earlier secondary cataract formation is associated with a younger age and with implantation of an IOL. Eyes undergoing a primary opening of the posterior capsule during the initial surgery of children with bilateral cataract achieved, in most cases, a better visual acuity than did their fellow eyes. CONCLUSION: Although possibly a choice in older children, a primary posterior capsulectomy combined with anterior vitrectomy is a must in younger children and particularly when implantation of an IOL is planned.