Saving Behavior under the Influence of Income Risk: An Experimental Study

Individual subjects are experimentally tested for precautionary saving. We use a simplified experimental framework and decision supporting tool to show that subject's consumption is consistent with precautionary saving. We find that subjects overact in changing current income. However, those over-reactions cancel each other, and subject's consumption behavior is close to the optimal solutions on average.Precautionary Saving,Experiment

日本古代の大土地経営と社会

学位の種別:課程博士University of Tokyo(東京大学

Transforming growth factor-β1 stimulates collagen matrix remodeling through increased adhesive and contractive potential by human renal fibroblasts

AbstractRenal tubulointerstitial fibrosis is the common final pathway leading to end-stage renal failure. Tubulointerstitial fibrosis is characterized by fibroblast proliferation and excessive matrix accumulation. Transforming growth factor-β1 (TGF-β1) has been implicated in the development of renal fibrosis accompanied by α-smooth muscle actin (α-SMA) expression in renal fibroblasts. To investigate the molecular and cellular mechanisms involved in tubulointerstitial fibrosis, we examined the effect of TGF-β1 on collagen type I (collagen) gel contraction, an in vitro model of scar collagen remodeling. TGF-β1 enhanced collagen gel contraction by human renal fibroblasts in a dose- and time-dependent manner. Function-blocking anti-α1 or anti-α2 integrin subunit antibodies significantly suppressed TGF-β1-stimulated collagen gel contraction. Scanning electron microscopy showed that TGF-β1 enhanced the formation of the collagen fibrils by cell attachment to collagen via α1β1 and α2β1 integrins. Flow cytometry and cell adhesion analyses revealed that the stimulation of renal fibroblasts with TGF-β1 enhanced cell adhesion to collagen via the increased expression of α1 and α2 integrin subunits within collagen gels. Fibroblast migration to collagen was not up-regulated by TGF-β1. Furthermore, TGF-β1 increased the expression of a putative contractile protein, α-SMA, by human renal fibroblasts in collagen gels. These results suggest that TGF-β1 stimulates fibroblast–collagen matrix remodeling by increasing both integrin-mediated cell attachment to collagen and α-SMA expression, thereby contributing to pathological tubulointerstitial collagen matrix reorganization in renal fibrosis

Possible Application of the Medicinal Plant Hyoscyamus albus in Phytoremediation: Excess Copper Compensates for Iron Deficiency, Depending on the Light Conditions

Seedlings of the medicinal plant Hyoscyamus albus were supplied with an excess of Cu to examine the possible application in phytoremediation. The seedlings were cultured in B5 medium supplied with basal 0.1 μM Cu and 200 μM Cu under various light conditions: short day (SD); long day (LD); and continuous light (CL). In addition, the effect of supplying 200 μM Cu under Fe deficiency was determined, in order to elucidate the interaction between Cu and Fe. Interestingly, Fe-deficiency symptoms that developed in plants grown with basic levels of Cu under LD almost disappeared when excess Cu was supplied. Plant growth mainly depended on the photo irradiation period (SD < LD~CL); and 200 μM Cu did not inhibit growth at all when Fe was available, whereas in the absence of Fe, CL caused damage to growth. Analysis of the Cu and Fe contents of the plants revealed that Cu was distributed equally in both the aerial parts and roots, whereas most of the Fe was found in the roots; under Fe deficiency, Cu accumulation in the roots apparently increased. Cu was mainly distributed in the soluble fraction, which included vacuoles and the cell-wall fraction. These results provide evidence indicating that H. albus seedlings are tolerant of Cu present in excess. Furthermore, excess Cu was able to compensate for Fe deficiency, depending on the light conditions. Continuous light inhibited this effect, probably as a result of the induction of Mn deficiency. The possible applications of this newly discovered cuprophyte are discussed

Gastric cancer with autoimmune gastritis

Background: Autoimmune gastritis is known to be associated with neoplastic lesions but the relationship between autoimmunity and tumorigenesis have not been sufficiently clarified. The aim of this study is to assess the clinicopathological characteristics of gastric cancer cases associated with autoimmune gastritis. Methods: A total of 24 patients diagnosed as early gastric cancer with autoimmune gastritis were registered. Chart reviews with the data including age, gender, state of Helicobacter pylori infection, comorbidity, and concomitant gastric diseases were conducted. As for the characteristics of gastric cancer, location, size, morphological type, histopathology, invasion depth, and the presence of metachronous or simultaneous lesion were assessed. These data from autoimmune gastritis group were compared with those from 301 patients of early gastric cancer as a control group. Results: The gastric cancer associated with autoimmune gastritis was located in the upper, middle, and lower parts in 28.1%, 53.1%, and 18.8%, respectively. The morphological types are as follows: 0-I, 9.4%; 0-IIa, 28.1%; 0-IIb, 15.6%; 0-IIc, 46.9%; and 0-III, 0.0%. The mean tumor size was 21.8 mm. While 90.6% were confined to the mucosa, 9.4% showed submucosal invasion. The histological classifications are as follows: tub1, 50.0%; tub2, 15.6%; pap, 21.9%; sig, 9.4%; and por, 3.1%. More numbers of female, protruded types, larger tumor size, papillary tumor, and that in the upper location were observed in autoimmune gastritis group compared to control group. Conclusion: Early gastric cancer associated with autoimmune gastritis demonstrated different characteristics from those without autoimmune gastritis including variety of tumor morphologies and histological types with female dominancy