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Biomedical subjects

R Fujisawa

Publications and source records attributed to R Fujisawa.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Graft-versus-host disease-like syndrome following blood transfusion in a patient with duodenal ulcer].

Graft-versus-host disease (GVDH)-like syndrome occurred in a 45 year-old man with duodenal ulcer who had received a transfusion of 8 units of packed red blood cells. Clinical features included high fever, macropapular rash, hepatic dysfunction, pancytopenia and, finally, fatal septicemia. A skin biopsy obtained from the chest revealed satellite cell necrosis of epidermal cells, mononuclear cell infiltrate of the upper dermis and epidermis, and vacuolar degeneration of basal cells. Autopsy bone marrow was aplastic. The occurrence of GVHD in immunologically normal individuals following blood transfusion is extremely rare.

Bone Marrow↗
PubMed1988

One- and two-dimensional NMR studies on the conformation of DNA containing the oligo(dA)oligo(dT) tract.

The resonances of the imino protons and all of the non-exchangeable protons (except for H5'/H5'') of d(CGCAAAAAAGCG)d(CGCTTTTTTGCG) have been assigned by means of one- and two-dimensional NMR spectroscopies. Qualitative analyses showed that the overall structure is of the B-form, but local conformational deviations exist. The NOEs between the imino protons of thymines and H2 of adenines suggest that the A-T base pairs are propeller-twisted to almost the same degree as in crystals. A remarkable chemical shift of H1' was observed for the residue located just before the oligo(dA)oligo(dT) tract, suggesting the presence of conformational discontinuity at the junctions between the oligo(dA)oligo(dT) tract and the other portions. Analyses of cross peaks in NOESY spectra between H2 of adenines and H1' of the 3'-neighbouring residues on the complementary strand revealed that the minor groove of the oligo(dA)oligo(dT) tract is narrow and compressed gradually, from 5' to 3', along the tract.

Base Sequence↗
PubMed1988

Increase of dentin phosphophoryn with dentin formation.

Dentin phosphophoryn was quantified on bovine and rabbit dentin at three developmental stages. Phosphophoryn was extracted from teeth with 0.6M HCl, and quantified as optical density on DEAE-cellulose chromatogram or as phosphoserine content. Bovine phosphophoryn showed progressive increase with formation of dentin. Matrix-associated phosphophoryn was also quantified as phosphoserine content in insoluble dentin residue which was extracted with 6 M urea after decalcification. This fraction increased with formation of dentin both in bovine and rabbit dentin. Phosphophoryn is thought to be related to the later stage of dentin formation.

Animals↗
PubMed1987

Effects of dentin phosphophoryn on precipitation of calcium phosphate in gel in vitro.

In vitro precipitation of calcium phosphate was carried out using a one-dimensional double diffusion system in agar gel. Bovine dentin phosphophoryn enhanced the sharpness of the precipitation bands, although it reduced the total amount of the precipitates. Dephosphorylated phosphophoryn had no effect on the pattern of precipitates. Therefore, phosphophoryn is thought to raise the local density of nucleation in spite of its inhibitory activity on apatite formation.

Animals↗
PubMed1986

Changes in interaction of bovine dentin phosphophoryn with calcium and hydroxyapatite by chemical modifications.

Dentin phosphophoryn was found to lose its precipitability with calcium ion when dephosphorylated or carboxylate-blocked, whereas precipitation of the intact protein was induced at calcium concentration as low as 2 mM. On the other hand, the adsorption capacity of phosphophoryn onto the hydroxyapatite surface increased when acidic groups were diminished by the above modifications.

Adsorption↗
PubMed1986

Ultrastructural study of the histogenesis of membranocystic lesions (Nasu) in diabetics.

In order to clarify the histogenesis of membranocystic lesion (MCL) of the skin, 14 biopsies obtained from the shins and feet of diabetics were examined by light and electron microscopy. MCL was observed in 10 of 14 cases, including 7 pigmented pretibial patches (PPP), each a case of diabetic bulla, callus of the knee, and ordinary psoriasis. Ultrastructurally, MCL was characterized by 3 fundamental types of structure: tortuous thick bands composed of well-developed minute tubular structures; shrubbery-like structures in sectional profile consisting of accumulated tiny cysts and microprojections; and thin membranes without minute tubular structures. The small vessels in the dermis and subcutaneous tissue indicated the changes of microangiopathy. Present observations suggested that MCL was derived from subcutaneous fat cells and was displaced into the dermis to be disposed by histiocytes. Circulatory disturbance due to diabetic microangiopathy in the subcutaneous tissue could be one of the contributory factors in the formation of MCL.

Aged↗
PubMed1986

Identification of dentin phosphophoryn localization by histochemical stainings.

Phosphophoryn, the most abundant of the dentin non-collagenous proteins, has been considered to be related in function to the mineralization process. In the present study, identification of dentin phosphophoryn localization was attempted using newly developed, precautionary histological methods by which phosphophoryn was retained in the sections during the specimen preparation and stained selectively in situ. Phosphophoryn was found to be present widely in all of the calcified dentin except the mantle dentin, the external, first-formed portion of dentin, but was not found in the predentin, the inner, uncalcified layer of dentin. These results indicate that phosphophoryn is apparently related to the mineral phase of calcified dentin and that the mineralization process of mantle dentin, which is formed before the odontoblasts are fully differentiated, may be different from that of circumpulpal dentin.

Acetates↗
PubMed1985

In vivo cleavage of dentin phosphophoryn following beta elimination of its phosphoserine residues.

Phosphophoryn, a unique phosphoprotein in dentin, has a polydisperse character. Keto acid was found to be present in this protein by condensation reaction with dinitrophenyl (DNP)-hydrazine and was identified to be pyruvate from the result that [3H]lactate was formed by the reduction of phosphophoryn with [3H]NaBH4. In the case of phosvitin, incorporation of DNP-hydrazine was much less than in phosphophoryn, even after the same treatment as the extraction procedure of phosphophoryn. DNP-hydrazine incorporation was much higher in the phosphophoryn of mature dentin than in dentin of unerupted teeth. From these results, pyruvate was though to be formed time dependently in vivo by beta elimination of phosphoserine residues and subsequent cleavage of the peptide chain, which may contribute to the polydispersity of phosphophoryn.

Animals↗
PubMed1984

Presence of lysinoalanine and histidinoalanine in bovine dentin phosphoprotein.

Trypsin digestion and successive calcium-induced precipitation of the insoluble bovine dentin matrix effectively separated the collagen and phosphoprotein fractions which were firmly associated together in this material. Amino acid analysis by four different systems revealed that the lysinoalanine and histidinoalanine, which had been previously reported to occur in the human dentin collagen, were concentrated in the phosphoprotein fraction but were not present in the collagen fraction. Furthermore, it was found that the free-type phosphoprotein which was isolated from EDTA extract of dentin powder also contained both "cross-linking" amino acids. The results indicated the both "cross-links" distributed within the dentin phosphoprotein and were not likely to contribute the unique stability of dentin collagen.

Animals↗
PubMed1984

Systematic purification of free and matrix-bound phosphophoryns of bovine dentin: presence of matrix-bound phosphophoryn as a distinct molecular entity.

Free and matrix-bound phosphophoryns, both highly phosphorylated proteins in dentin, were prepared from EDTA extract and CNBr-digests of bovine dentin. The two components were purified by DEAE-cellulose, SP-Sephadex, and gel filtration chromatography. The matrix-bound component was eluted as a distinct peak from the free component in the above chromatographic systems. Amino acid composition of the purified matrix-bound component indicated that this component consisted of phosphophoryn and collagen in the ratio of 2:3 based on the number of the residues. The matrix-bound component could not be reconstituted by mixing phosphophoryn with collagen CNBr peptides. Artificial crosslink products of free phosphophoryn and collagen CNBr-peptides by the carbodiimide method showed similar properties to the physiological matrix-bound phosphophoryn. The bond between phosphophoryn and collagen of the matrix-bound component is assumed to be a covalent crosslink.

Amino Acids↗