Wnt Signaling and Aging of the Gastrointestinal Tract

Aging is considered a risk factor for various diseases including cancers. In this aging society, there is an urgent need to clarify the molecular mechanisms involved in aging. Wnt signaling has been shown to play a crucial role in the maintenance and differentiation of tissue stem cells, and intensive studies have elucidated its pivotal role in the aging of neural and muscle stem cells. However, until recently, such studies on the gastrointestinal tract have been limited. In this review, we discuss recent advances in the study of the role of Wnt signaling in the aging of the gastrointestinal tract and aging-related carcinogenesis.     

Inductance-controlled electroabsorption Modulator modules using the flip-chip bonding technique

The wire-bonding technique is widely used for the connections between the electroabsorption (EA) modulator chips and the electrical signal transmission lines. However, the parasitic inductance of the bonding wire degrades the electrical characteristics of the EA modulator modules in a high-frequency region. In this paper, we theoretically analyze the influence of parasitic inductance on the base-band digital transmission and obtain the relationship between the EA modulator capacitance and the optimum lead inductance. For precise inductance control, we introduced the flip-chip bonding (FCB) technique and fabricated 40-Gb/s EA modulator modules.     

Thermal diffusivity measurements of thin films and multilayered composites

This review discusses the following methods for measuring thermal diffusivity of thin materials: ac calorimetric method, flash method, mirage-effect method, picosecond time-resolved thermoreflectance method, photoacoustic method, etc. The measurements are classified into the following three cases: (a) that yield thermal diffusivity parallel to the surface of a thin material, (b) that yield thermal diffusivity perpendicular to the surface, and (c) that yield thermal diffusivity perpendicular to the surface of a thin material but deposited on a solid substrate. The contribution of inhomogeneity in the spatial distribution of the imparted thermal energy and obscureness at the edge of the restricted region, to which uniform thermal energy is imparted, is considered in each case. The contribution of temporal distortion of the temperature pulse, waves, etc., is considered in each measurement. The proper thickness of samples required for the measurements is discussed. In some of the measurements, the applicable materials are restricted, for instance, thermoreflectance measurements are applicable to metallic samples only.Paper presented at the Second U.S.-Japan Joint Seminar on Thermophysical Properties, June 23, 1988, Gaithersburg, Maryland, U.S.A.     

Impacts of management styles on the relations between supervisor needs and leadership patterns.

The needs for both independence and benevolence of 60 supervisors were assessed with the Survey of Interpersonal Values. Supervisor Independence Need?×?Structure Correlation was significant when manager structure was low; Supervisor Benevolence Need?×?Consideration Correlation was significant when manager consideration was high. Manager structure exerted more influence on supervisor structure for supervisors low in need for independence than for supervisors high in that need. (7 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and anti-influenza virus-A activity of circular dumbbell RNA DNA chimeric oligonucleotides

We have designed a new type of antisense oligonucleotide, containing two hairpin loop structures with RNA/DNA base pairs (sense (RNA) and antisense (DNA)) in the double helical stem (nicked and circular dumbbell DNA/RNA chimeric oligonucleotides). The reaction of the nicked and circular dumbbell DNA/RNA chimeric oligonucleotides with RNase H gave the corresponding anti-DNA together with the sense RNA cleavage products. These oligonucleotides were more resistant to exonuclease attack. We also describe the anti-Fluv activities of circular dumbbell DNA/RNA chimeric oligonucleotides.     

Donor leukocyte transfusion as treatment for relapsed chronic myelogenous leukemia after allogeneic bone marrow transplantation

We reviewed 4 cases of high-grade transitional-cell carcinoma (TCC) of the urinary tract with solitary pulmonary metastases that were studied by transthoracic needle aspiration biopsy cytology. There were two grade II and two grade III TCCs. The two grade II tumors yielded, in needle aspirates, syncytial tumor-cell clusters showing ill-defined, granular cytoplasm and slightly pleomorphic nuclei with inconspicuous nucleoli. In one case the tumor-cell cluster showed a focal acinar arrangement, mimicking cells of an adenocarcinoma. In both cases the electron microscopy (EM) study of aspirated tumor cells revealed epithelial cells with well-formed cell junctions, intracytoplasmic vesicles, apical short microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial neoplasm. The two grade III TCCs yielded, in needle aspirates, pleomorphic malignant cells singly and in small clusters, showing well-defined, granular cytoplasm and pleomorphic nuclei containing prominent nucleoli, suggesting a poorly differentiated adenocarcinoma or an anaplastic large-cell carcinoma. By EM examination the aspirated tumor cells from one case revealed well-formed cell junctions, intracytoplasmic vesicles, poorly formed microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial differentiation. In the other case the tumor cells were pleomorphic cells with occasional cell junctions and no ultrastructural features as seen in the other 3 cases of TCC. The tumor cells from the two grade II TCCs showed strong immunopositive reaction with keratin 7 antibody and weakly positive reaction with carcinoembryonic antigen antibody (CEAA), while those of the two grade III TCCs displayed only a weak and focal immunopositive staining with keratin 7 antibody and strong reaction with CEAA.     

Extensive analysis of the retinoblastoma gene in adult T cell leukemia/lymphoma (ATL)

The retinoblastoma susceptibility gene (Rb) plays a key role in regulating the cell cycle in association with cyclins and cyclin-dependent kinases (CDKs). Alteration of the Rb gene as well as CDK inhibitors (CDKIs) leads to deregulated cellular growth which promotes cancer formation. We examined the genomic configuration of the entire Rb gene in 40 primary adult T cell leukemias/lymphomas (ATL) and two ATL cell lines by Southern blotting and also by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analyses. Homozygous loss of exon 1 was identified in one of 21 acute ATL, one of 15 chronic ATL, and none of four lymphomatous ATL samples. No point mutations were identified. Previously, we found that 10 of these same ATL samples had alterations of either p16(INK4A) (homozygous deletion) or p27(kip1) (homozygous deletion or point mutation). Although the numbers are very low, none of the samples with an aberrant Rb gene had an altered CDKI and vice versa, suggesting that both genes probably operate in a common pathway and alteration of either can provide these cells with a growth advantage.     

Lactate transport and lactate transporters in skeletal muscle

The study of lactate transport in skeletal muscle had until recently been hampered by the lack of suitable sarcolemmal vesicle preparations. Researchers are now at the threshold of developing some very new understandings about the movement of lactate into and out of skeletal muscle with (a) evidence for a lactate transport system in skeletal muscle, (b) the very recent cloning of several monocarboxylate transporter genes, (c) the expression of at least one monocarboxylate transporter protein that facilitates the transport of lactate in heart and skeletal muscle, and (d) the realization that lactate transport can be altered with changes in chronic muscle activity. The MCT1 expression patterns in metabolically heterogeneous skeletal suggests that a primary role of this lactate transporter is to take up lactate into the oxidative muscle fibers where it may be used as a fuel in mitochondrial oxidation. Increments in both MCT1 and lactate transport with training support this role.     

Finite element analysis of formability of a few kinds of special steel sheets

Deep drawing processes of various special steel sheets are simulated by the rigid-plastic finite element method. To predict the forming limit a criterion for ductile fracture is applied. From the histories of stress and strain in each element calculated by the finite element simulation, the fracture initiation site and the critical stroke are predicted by means of the ductile fracture criterion. The predictions so obtained are compared with experimental observations. The results show that the finite element analysis combined with the ductile fracture criterion is useful to predict the forming limit in a wide range of sheet steels.     

Effects of goals and feedback on performance in groups.

In the first study, 26 undergraduate pairs and 52 individuals worked on a perceptual speed task for 20 min to win prizes based on performance. The pairs set group goals and individual goals to be attained, whereas the individuals set only individual goals. Despite the equal levels of individual goals set, goal acceptance and performance were significantly higher for the pairs than for the individuals. A stepwise hierarchical regression analysis supported the contributions of goal acceptance and group goals to performance. In the second study, 50 undergraduate pairs were assigned a goal to be attained as teams on a perceptual speed task lasting 15 min. Group and individual task feedback, given after 7? min of work, significantly improved performance only for those subjects who were below target for either group or individual feedback, yielding interaction effects on performance. The implications of the findings for group goal setting, social loafing, and organizational effectiveness are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)