Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.     

Ongoing prospective study of segmentectomy for small lung tumors. Study Group of Extended Segmentectomy for Small Lung Tumor

BACKGROUND: Lesser resection for small lung tumors remains an unresolved problem. This study was conducted to see whether this type of operation is acceptable or not. METHODS: From 1992 to 1994, 55 patients were enrolled in a multicenter trial of limited surgical resection for peripheral tumors of less than 2 cm diameter. The procedure consisted of segmentectomy with exploration of lymph nodes by examining frozen sections. The operation was modified if the report was positive. The intersegmental plane was identified by keeping the resected segments inflated and the preserved segments collapsed. To divide the plane, stapling or electrocauterization on the edge of the collapsed area was used. In this way the resection line was delivered beyond the burdened segment; this was called extended segmentectomy. RESULTS: There were no perioperative deaths, but there were eight postoperative deaths. In 1 patient who died because of local recurrence, it had been known that the margin to the lesion had been narrow (15 mm); 1 had bilateral intrapulmonary nodules, 1 had nodules in the side that was not operated on, and another succumbed to a second neoplasm of small cell lung cancer 4 years after the first operation. The remaining 4 died of nonpulmonary diseases. Almost all other patients are alive and free from recurrence, except for 1 in whom N2 disease was not detected intraoperatively but was confirmed after the operation. CONCLUSIONS: The interim results suggest that extended segmentectomy is applicable in patients with a small peripheral lung cancer. However, a wide margin and aggressive intraoperative pathologic examinations are mandatory.     

A new spontaneous animal model of NIDDM without obesity in the musk shrew

The EDS (early-onset diabetes in suncus) colony has been developed as a new closed breeding colony of the musk shrew (Suncus murinus, Insectivora) exhibiting a high incidence of spontaneous diabetes mellitus. We investigated the characteristic features of diabetic shrews in this colony. All diabetic shrews are characterized by glycosuria (Tes-tape value > or = 3+), hyperglycemia (23.3 +/- 0.8 mmol/l) and polyuria, and they were affected by the age of 3 months. Cumulative incidence (64.1% in males and 27.8% in females) was kept intact after the age of 3 months. The growth pattern of diabetic shrews was similar to that of non-diabetic shrews, and obesity was not consistent in diabetic shrews. The intraperioneal glucose tolerance test revealed both impaired glucose tolerance and impaired insulin secretion in diabetic shrews. Insulin sensitivity of diabetic shrews decreased in the intraperioneal insulin tolerance test. Neither severe hypertrophy nor lymphocytic infiltration was observed in pancreatic islets of diabetic shrews. These facts suggested that diabetic shrews in the EDS colony should be classified as early-onset non-insulin dependent diabetes mellitus (NIDDM) without obesity. Early-onset of severe hyperglycemia with impaired glucose tolerance is a distinctive character compared with other non-obese NIDDM models in rodents. We concluded that the diabetic shrews in the EDS colony are a new animal model of human NIDDM without obesity.     

Serotonergic neurons are present and innervate blood vessels in the olfactory bulb of the laboratory shrew, Suncus murinus

The distribution and characteristics of serotonin-immunoreactivity in the olfactory bulb of the laboratory shrew (Suncus murinus, insectivore) was studied immunohistochemically. Serotonergic neurons were found only in the subependymal layer of the main olfactory bulb. These neurons were 8-12 microm in size and bipolar in shape. These serotonergic neurons had smooth nerve fibers which innervate blood vessels located mainly in the subependymal layer of the main olfactory bulb. On the other hand, other serotonergic nerve fibers with varicosities, which must be extrinsic, were detected in most olfactory layers except the olfactory nerve layer. This result suggests that intrinsic serotonergic neurons may control blood vessels and varicose serotonergic nerve fibers may act to modulate the olfactory transmission.     

Development of field‐emission displays

Abstract— FEDs are one of the attractive flat‐panel displays that realize high‐quality motion images and low power consumption. FEDs are constructed by using three elemental technologies: micro‐ or nano‐fabrication technology of emitters, opto‐electronic semiconductor technology of anode patterns, and vacuum packaging technology. Each of the three elemental technologies is essential to realize FEDs. The present status of each three technologies, especially the improvement of Spindt‐type field emitters, the trend of flat vacuum packages, and development of phosphors for FEDs is described in this paper.     

Evolution of iterated prisoner's dilemma game strategies in structured demes under random pairing in game playing

We discuss the evolution of strategies in a spatial iterated prisoner's dilemma (IPD) game in which each player is located in a cell of a two-dimensional grid-world. Following the concept of structured demes, two neighborhood structures are used. One is for the interaction among players through the IPD game. A player in each cell plays against its neighbors defined by this neighborhood structure. The other is for mating strategies by genetic operations. A new strategy for a player is generated by genetic operations from a pair of parent strings, which are selected from its neighboring cells defined by the second neighborhood structure. After examining the effect of the two neighborhood structures on the evolution of cooperative behavior with standard pairing in game-playing, we introduce a random pairing scheme in which each player plays against a different randomly chosen neighbor at every round (i.e., every iteration) of the game. Through computer simulations, we demonstrate that small neighborhood structures facilitate the evolution of cooperative behavior under random pairing in game-playing.     

Evaluation of statistical uncertainty of cement-treated soil strength using Bayesian approach

The statistical parameters for the strength of cement-treated soil are evaluated by the strength of cored samples retrieved from cement-treated columns for a quality assurance procedure in the deep mixing method. The sample parameters include the statistical uncertainty associated with the statistical sample size and other factors. Therefore, a probabilistic characterization of the statistical parameters of strength is required to quantify the statistical uncertainty in the quality assurance process. This paper presents a quantitative analysis of the statistical uncertainty for the estimation of the strength of cement-treated columns. The Bayesian approach is adopted to evaluate the statistical uncertainty occurring in the determination of the statistical parameters of the strength from observed data. The inference is performed via a Markov chain Monte Carlo method, in which samples of the parameters are sequentially drawn from a joint posterior probability distribution. An example analysis is performed to illustrate the statistical uncertainty of the unconfined compressive strength of cored samples retrieved from cement-treated columns. The results show that the statistical parameters, inferred from the data with the sample size of approximately 40, include considerable uncertainty. The variability of the estimated statistical parameters is found to depend on both the sample size and the spatial correlation. The influence of the statistical uncertainty, caused in the estimation of the mean and standard deviations in strength, is examined within the framework of quality assurance in the deep mixing method.     

Magnetization Mechanism of Si‐Gradient Steel Sheet Manufactured by CVD Siliconizing Process

Si‐gradient steel sheet, which has a silicon concentration gradient in the sheet thickness direction, manufactured by the chemical vapor deposition siliconizing process, possesses unique magnetic properties. In this paper, the magnetization behaviors of single crystals of Si‐gradient steel sheet are investigated in the <100> and <110> directions, comparing with Si‐homogeneous steel sheet, in order to clarify the magnetization mechanism. The internal stress of Si‐gradient steel sheet was evaluated. The induced magnetic anisotropy which arising according to the magnetoelastic effect is considered to play an important role in the magnetization process of Si‐gradient steel sheet. The reduction of eddy current loss can be explained by the effect of the magnetic flux concentration at the sheet surface resulting from the internal stress.     

Catalytic azide reduction in biological environments

In the quest for the identification of catalytic transformations to be used in chemical biology and medicinal chemistry, we identified iron(III) meso-tetraarylporphines as efficient catalysts for the reduction of aromatic azides to their amines. The reaction uses thiols as reducing agents and tolerates water, air, and other biological components. A caged fluorophore was employed to demonstrate that the reduction can be performed even in living mammalian cells. However, in vivo experiments in nematodes (Caenorhabditis elegans) and zebrafish (Danio rerio) revealed a limitation to this method: the metabolic reduction of aromatic azides.     

Successful reconstitution of human hematopoiesis in the SCID-hu mouse by genetically modified, highly enriched progenitors isolated from fetal liver

Highly purified CD34++CD38-Lin- hematopoietic progenitors isolated from human fetal liver were infected with the murine retroviral vector, MFG nls-LacZ, which encodes a modified version of the Escherichia coli beta-galactosidase gene. Progenitors that were cocultured with the packaging cell line could reconstitute human bone marrow or thymus implanted in SCID-hu mice. Expression of the beta-galactosidase gene was observed in primitive and committed clonogenic progenitors, mature myeloid, B-lineage cells, and T-lineage cells for up to 4 months after injection into SCID-hu mice. Furthermore, hematopoietic reconstitution by genetically modified progenitor cells could be achieved by the injection of the cells generated from as few as 500 CD34++CD38-Lin- cells, suggesting efficient retroviral gene transfer into fetal liver progenitors.