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E-cadherin is a Ca2+-dependent intracellular adhesion molecule in the epithelial tissue. The urothelium also expresses E-cadherin molecules. We determined E-cadherin expression in bladder carcinoma immunohistochemically and investigated its relationship with pathological and clinical data. The percentage of cases showing pattern B, less than 50% of which cancer cells expressed the same intensity of E-cadherin as did the normal epithelium, was higher in cases of high-grade or high-stage tumors as compared with those of low grade or low stage. Heterogeneous staining was observed in the same specimens, which suggested changes in the cell phenotype. Immunoblotting demonstrated no evidence of gross alteration of E-cadherin molecules. The decrease in E-cadherin expression was associated with the invasiveness of bladder carcinoma, as has been reported in other carcinomas.

In preparation for biosynthetic studies on the 3,4-dihydroxy-2,6-dimethyl-5-phenylvaleric acid portion of neoantimycin (1), the ¹H and ¹³C NMR signals of 1 were assigned unambiguously by means of 2D correlation spectroscopy and NOE experiments. The previously undetermined absolute stereochemistry at C-15 and C-16 was deduced as (S) and (S). The structure of isoneoantimycin (2) was also elucidated. The methyl groups of methionine and propionate were incorporated stereospecifically into C-13 and C-12 of 1, respectively, and the configuration of the methyl group of methionine is inverted in the process. The results also suggest the intervention of phenylpyruvate as an actual precursor.

The immune system can recognize differentiation antigens that are selectively expressed on malignant cells and their normal cell counterparts. However, it is uncertain whether immunity to differentiation antigens can effectively lead to tumor rejection. The mouse brown locus protein, gp75 or tyrosinase-related protein 1, is a melanocyte differentiation antigen expressed by melanomas and normal melanocytes. The gp75 antigen is recognized by autoantibodies and autoreactive T cells in persons with melanoma. To model autoimmunity against a melanocyte differentiation antigen, mouse antibodies against gp75 were passively transferred into tumor-bearing mice. Passive immunization with a mouse monoclonal antibody against gp75 induced protection and rejection of both subcutaneous tumors and lung metastases in syngeneic C57BL/6 mice, including established tumors. Passive immunity produced coat color alterations but only in regenerating hairs. This system provides a model for autoimmune vitiligo and shows that immune responses to melanocyte differentiation antigens can influence mouse coat color. Immune recognition of a melanocyte differentiation antigen can reject tumors, providing a basis for targeting tissue autoantigens expressed on cancer.

AbstractParasibirskite, with the ideal formula Ca2B2O5·H2O, is a new mineral species found at Fuka, Okayama Prefecture, Japan. It is a polymorph of sibirskite, CaHBO3, and occurs as subparallel aggregates of tabular crystals up to 40 × 20 × 3 µm in size. Associated minerals are takedaite, olshanskyite, sibirskite, frolovite and calcite. The mineral is white, and has a weak pearly luster. Optically, the mineral is biaxial positive, a 1.556(2), ß 1.593(2), ? 1.663(2) (? 589 nm). The Vickers microhardness of aggregates is 121 kg mm-2. The mineral is monoclinic with space group of P21/m, a6.722(4), b5.437(2), c3.555(2) Å, ß 93.00(5)°, V 129.8(2), Å3. The strongest lines in the X-ray powder pattern [din Å (I)(hkl)] are 2.237(100)(300), 6.73(70)(100), 2.975(60)(011), 3.354(30)(200), 2.855(20)(210) and 1.776(20) (002). Wet chemical analysis, electron-microprobe analysis and ICP emission spectrometry give the values CaO 56.06 %, B2O334.10 %, H2O 9.97 % and total 100.13%. The empirical formula calculated on the basis of O = 6 is Ca1.985B1.945O4.901·1.099H2O, for Z = 1, Dcalc2.54 and Dmeas2.50(1) g cm-3. Parasibirskite is formed by hydrothermal alteration of takedaite.