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Biomedical subjects

R Fujisawa

Publications and source records attributed to R Fujisawa.

At least 55 records · Page 3Linked to original sources
PubMed1995

A single retroviral gag precursor signal peptide recognized by FBL-3 tumor-specific cytotoxic T lymphocytes.

Several dominant T-cell receptors of cytotoxic T-lymphocyte (CTL) clones specific for FBL-3 tumor antigen were clonally amplified in mixed lymphocyte tumor cell cultures derived from an individual immune mouse. Every CTL clone analyzed had a common specificity for a single epitope in the precursor to cell membrane-associated nonstructural gag-encoded protein, Pr75gag, which can be minimally identified by nine amino acid residues, SIVLCCLCL. This epitope is located within the hydrophobic signal sequence motif that mediates translocation of the protein into the endoplasmic reticulum. These novel observations suggest that expression of Pr75gag in FBL-3 tumor cells led to the amplification of CTLs which recognize the signal sequence of the nonstructural gag-encoded glycoprotein precursor.

Amino Acid Sequence↗
PubMed1995

Protective efficacy of nonneutralizing monoclonal antibodies in acute infection with murine leukemia virus.

We have used an experimental retrovirus infection to study the roles played by different antibodies in resistance to both infection and disease. A molecularly cloned chimeric murine leukemia virus was used to induce acute lethal neurological disease in neonatal mice. A panel of monoclonal antibodies directed against the Gag and Env proteins was tested for protective efficacy. In vitro neutralization assays demonstrated that anti-Env antibodies gave different degrees of neutralization, while no anti-Gag neutralized the virus. In vivo experimental endpoints were onset of clinical signs and premoribund condition. As expected, different anti-Env antibodies demonstrated different degrees of protection which correlated with their neutralizing abilities. Surprisingly, anti-Gag antibodies directed against both p15 (MA protein) and p30 (CA protein) were also protective, significantly delaying the onset of disease. No protection was seen with either of two control antibodies. The protection with anti-Gag was dose related and time dependent and was also produced with Fab fragments. Treatment with anti-Gag did not prevent viremia but resulted in a slight slowing in viremia kinetics and decreased levels of virus in the central nervous systems of mice protected from disease. These data indicate that nonneutralizing antiretroviral antibodies can influence the outcome of retroviral disease. The data also suggest a functional role for cell surface expression of Gag proteins on murine leukemia virus-infected cells.

Animals↗
PubMed1994

Physiology and pathology of host immune responses to exogenous and endogenous murine retroviruses--from gene fragments to epitopes.

Spontaneous and induced immunity against exogenous Friend murine leukemia retrovirus infection is controlled by four H-2-linked host genes and a single non-H-2 gene. Recognition of the envelope glycoprotein gp70 of Friend virus by helper T cells is restricted by Ab and hybrid Eb/k(d) class II MHC molecules. By expressing portions of the env gene and by utilizing synthetic oligopeptides, an Ab-restricted and a hybrid Eb/d-restricted helper T cell epitopes were identified in the N-and C-terminal portions of gp70, respectively. These epitopes differ in their amino acid sequences from the previously reported endogenous retroviral peptides naturally presented by mouse MHC class II molecules. Possible roles of recombinant polytropic viruses in the induction of autoimmune responses against endogenous retroviral antigens are also discussed.

Amino Acid Sequence↗
PubMed1994

In vitro and in vivo association of dentin phosphophoryn with alpha1CB6 peptide of type I collagen.

A small number of molecules of phosphophoryns, dentin phosphoproteins, are associated to collagen tightly with the maturation of dentin. As an in vitro model of the process, we examined non-covalent association of phosphophoryns and collagen CNBr peptides. Cyanogen bromide peptides of type I collagen were separated with electrophoresis and transferred to a membrane, which was probed with labeled phosphophoryns. Phosphophoryns were bound preferentially to alpha1CB6 peptide. Another experiment using a cleavable crosslinking agent also demonstrated the affinity between phosphophoryns and the alpha1CB6 region of collagen. The matrix-bound fraction of phosphophoryns was solubilized by CNBr digestion of bovine dentin, and was partially purified. Compositional analysis revealed that the fraction was composed of association products of phosphophoryns and collagen at the ratio of 2:3. Considering the high molecular weight of the fraction, one phosphophoryn molecule should be associated with several collagen peptides. The fraction reacted with the antibody against alphalCB6 peptide. When the fraction was digested with lysyl endopeptidase, several peptides that coincided with peptides from alpha1CB6 were released. One of the peptides was sequenced and identified to be a peptide with Asp 975 of the alpha1(I) chain as an amino terminal residue. The alpha1CB6 peptide may be involved in the matrix-bound fraction, although involvement of other collagen peptides cannot be ruled out. Phosphophoryns may associate with collagen at the alpha1CB6 region at first, and then be immobilized on it, possibly by covalent crosslinking, with maturation of dentin. Binding of several alpha1CB6 peptides to a single phosphophoryn molecule is possible in current 3-dimensional models of collagen packing in mineralized tissue, which allows alignment of several hole zones in register.

Amino Acid Sequence↗
PubMed1993

Differences in composition of cell-attachment sialoproteins between dentin and bone.

Matrices of dentin and bone were compared with respect to the content of cell-attachment sialoproteins. The levels of two sialoproteins, osteopontin (OPN) and bone sialoprotein (BSP), were determined in dentin and bone by immunochemical procedures. Polyclonal antibodies against bovine BSP and an antibody against the amino-terminal decapeptide of rat OPN were used. The relative levels of OPN and BSP in dentin were less than one-tenth of the levels in bone. The differences between dentin and bone levels of OPN and BSP were thus larger than those for osteonectin or bone Gla protein in the two tissues. The scarcity of the cell-attachment proteins in dentin may reflect the metabolic inactivity of dentin.

Animals↗
PubMed1993

[Parapsoriasis en plaque suspected of progression to mycosis fungoides associated with extranodal malignant B cell lymphoma of the cheek].

A 59-year-old female, clinically diagnosed as having parapsoriasis en plaque for ten years, was referred on June 1991 to the Department of Oral Surgery in the Dental School of showa University with a complaint of painless swelling of the left malar area. The swelling was found to have been caused by a tumor. Since the excised tumor was suspected to be a malignant lymphoma, she was admitted to our hospital. The specimen was subsequently confirmed to be a malignant lymphoma of the diffuse large cell type according to the LSG classification, and was immunologically confirmed to be a B cell lymphoma. In addition, the excised skin was suspected of incipient mycosis fungoides. She was classified as having stage IE disease according to her bone marrow biopsy and other examinations. she was treated with combination of chemotherapy (CHOP) and radiation therapy. This subject was interesting because her tumor probably resulted from a parapsoriasis en plaque skin lesion.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Effects of a bone lysine-rich 18 kDa protein on osteoblast-like MC3T3-E1 cells.

A lysine-rich 18 kDa protein was isolated from bovine bone and examined for its effects on osteoblast-like MC3T3-E1 cells. This protein is homologous to a heparin-binding protein in brain and uterus. This protein enhanced cell attachment independent of the Arg-Gly-Asp cell-binding sequence and stimulated proliferation during the growth phase. Addition of this protein to cell cultures on days 11, 12, and 13 after confluency resulted in a 1.6-2.0-fold increase in the alkaline phosphatase activity and little increase in the DNA content. These findings suggest that the 18 kDa protein may be functional in promoting the proliferation and differentiation of osteoblasts.

3T3 Cells↗
PubMed1992

Affinity of bone sialoprotein and several other bone and dentin acidic proteins to collagen fibrils.

Bone and dentin contain several kinds of mineral-binding proteins and cell-attachment proteins. The authors examined the affinity of these proteins to type I collagen, a major matrix protein of the tissue. Bone sialoprotein (BSP), bone Gla protein (BGP), bone small proteoglycan II (PG II), osteonectin (ON), and dentin phosphophoryn (DPP) were labeled with fluorescein isothiocyanate and incubated with reconstituted type I collagen fibril. DPP, BGP, BSP, and PG II were absorbed significantly to the collagen fibril at physiological ionic strength with dissociation constants of 10(-6)-10(-7) M. BSP and PG II enhanced the fibrillogenesis of collagen. These acidic proteins can affect the surface properties of collagen fibril, and BSP, having the cell-attachment sequence Arg-Gly-Asp, possibly mediates interaction between collagen fibril and cells.

Amino Acid Sequence↗
PubMed1991

Preferential adsorption of dentin and bone acidic proteins on the (100) face of hydroxyapatite crystals.

Interaction of bone and dentin proteins with minerals is an elementary step in the regulation of mineralization in these tissues. Adsorption of acidic non-collagenous proteins on hydroxyapatite was examined using fluorescence-labeled protein and synthetic hydroxyapatite. Phosphophoryn, bone Gla protein, osteonectin and bone small proteoglycan II were prepared and labeled with fluorescein. All of these proteins were adsorbed on hydroxyapatite with a dissociation constant on the order of 10(-7) M. The more acidic proteins had lesser binding capacities. Hydroxyapatite single crystals were incubated with labeled proteins and observed with a fluorescence microscope. Phosphophoryn and other acidic proteins were adsorbed preferentially on the (100) face of the crystal. This preferential adsorption of the acidic proteins may be responsible for the morphogenesis of biological hydroxyapatite.

Animals↗
PubMed1991

Identification of the rat bone 60K acidic glycoprotein as alpha 2HS-glycoprotein.

Previous reports have described an Mr 60,000-64,000 glycoprotein present in guanidium chloride (GdmCl)/EDTA extracts of bovine and rat bone. We have purified this protein from the long bones of rats and have raised polyclonal antibodies to the purified protein. The 60K glycoprotein has amino acid and carbohydrate compositions that are similar to those reported for the 60-64K protein(s). Several lines of evidence indicate that the 60K bone glycoprotein is the rat homologue of human alpha 2HS-glycoprotein. First, immunochemical data demonstrated that the 60K bone glycoprotein was present in serum as well as in EDTA/GdmCl extracts of bone. Second, immunolocalization and metabolic labelling experiments showed that the 60K protein is synthesized in liver and not in bone cells, although it is sequestered in vascularized regions of bone matrix. Finally, the NH2-terminal sequence for the rat 60K bone glycoprotein was highly similar to that of the human alpha 2HS-glycoprotein A chain. A surprising finding was that small amounts of contaminating 60K/alpha 2HS-glycoprotein were found in several protein fractions purified by ion-exchange chromatography of bone EDTA/GdmCl extracts. Because this protein was found to be highly immunogenic, the presence of anti-60K antibodies in anti-sera prepared against purified bone proteins should be considered as a potential problem.

Amino Acid Sequence↗
PubMed1991

Effect of non-enzymatic glycosylation and heating on browning of human stratum corneum and nail.

The purpose of the present study was to examine the effect of non-enzymatic glycosylation and subsequent heating on the browning of the plantar stratum corneum and the finger-nail, and to elucidate the pathogenesis of the yellow skin and the yellow nail seen in diabetic subjects. We incubated stratum corneum and nail from non-diabetics in 0 (control), 10 (only nail), 20 (only nail), 100 and 250 mM glucose buffer at 37 degrees C for 5 days. These glycosylated samples were dialysed against distilled water for 96 h. Distilled water was changed every 24 h. Then samples were dried for 24 h. The extent of non-enzymatic glycosylation was measured by furosine content. Each 5 mg of sample was hydrolysed by 6 N HCl and processed for measurement of furosine by high-performance liquid chromatography. The rest of each sample was stored at 37, 42 (only nail), 47 and 52 degrees C for 14 days. Browning of the stratum corneum was assessed macroscopically, and that of the nail by spectrophotometry. Based on their spectrophotometric reflectances. Munsell's scores (H = hue score, V = lightness score, C = saturation score) and (H + C)/V were calculated for objective evaluation of browning. Incubation of the stratum corneum and nail with glucose buffer increased their non-enzymatic glycosylation (furosine) dose dependently. Macroscopically, the browning of the stratum corneum was enhanced in proportion to the glucose concentration and storage temperature. However, samples incubated in 10 and 20 mM glucose and stored at 42 degrees C did not show visible browning. Munsell's score of the nail samples treated by glycosylation and heating showed increased hue and saturation but reduced lightness. (H + C)/V values of these nail samples were significantly higher than those of the control. We could not detect any fluorescence with Wood light in the browned samples. The present in vitro study demonstrated that the browning of the stratum corneum and the nail depended on the extent of both non-enzymatic glycosylation and storage temperature. We suggested a hypothesis that the non-enzymatic glycosylation and the storage temperature of the stratum corneum and the nail might be a contributory factor in the development of yellow skin and yellow nail in diabetic patients.

Adult↗
PubMed1991

[Increased corneocyte surface area in the diabetic skin].

In attempt to prove the hypothesis that corneocyte surface area in diabetics is larger than that in age-matched non-diabetics, we collected corneocytes from 50 diabetics and 43 non-diabetics in different decades of life. We measured surface areas of 27 +/- 3 corneocytes in each subject, utilizing an image analyser (Kontron MOP-10), then we counted mean number of corneocytes collected in 7 diabetics and 7 non-diabetics. There was a significant correlation between corneocyte surface area and chronological age in non-diabetics, whereas there was no significant correlation in diabetics. Corneocyte surface area of diabetics was larger than that of non-diabetics in every decades of life. The differences were statistically significant in 4th, 7th and 8th decades of life. Mean number of corneocytes collected in non-diabetics was 2.21 +/- 0.47 (X 10(5)), whereas that in diabetics was 2.49 +/- 0.55 (X 10(5)). The present study suggested that turnover time of corneal layer of the skin might be delayed in diabetics.

Adult↗
PubMed1990

High-resolution solid-state nuclear magnetic resonance spectra of dentin collagen.

Insoluble collagen of bovine dentin was characterized by high-resolution solid-state 13C nuclear magnetic resonance (NMR) spectroscopy using a cross-polarization magic angle spinning procedure. A downfield shift was observed in the signal of hydroxyproline C beta compared with that in skin collagen, indicating a distortion in the hydroxyproline structure. A signal of 31P NMR was detected in dentin collagen that was compatible with the presence of matrix-associated phosphoprotein.

Animals↗
PubMed1990

[Clinical analysis of drug eruption due to iohexol (Omnipaque)].

We reported 7 cases of drug eruption due to Iohexol (Omnipaque) which was nonionic X-ray contrast agent without severe adverse reaction. They showed generalized edematous and erythematous plaques. The eruption appeared from 5 to 6 days after the examination when a patient had not been sensitized, or several hours after that when he/she had been already sensitized. No case showed any cross-sensitization with ionic contrast media, but some cases suggested the possibility of cross-sensitization among the nonionic contrast agents.

Adult↗
PubMed1989

Changes in levels of osteonectin in bovine dentine during tooth development.

Bovine incisors were classified into three developmental stages and non-collagenous proteins extracted from them. Sodium dodecyl sulphate gel electrophoresis of the extracts showed a reduction in osteonectin with the various stages. The reduction was confirmed by enzyme immunoassay using antiserum against bone osteonectin. This change is in contrast to dentine phosphoprotein, indicating functional differences between these two proteins.

Animals↗
PubMed1989

Glycosylated proteins of skin, nail and hair: application as an index for long-term control of diabetes mellitus.

The purpose of the present study was to compare the degrees of nonenzymatically glycosylated proteins in the skin (stratum corneum), the nail, the hair, and hemoglobin obtained simultaneously from the same subject and to evaluate the most useful sample for management of diabetic complications. Fifty-one diabetic patients and 20 control patients were examined, utilizing furosine determination. Furosine value of the skin in diabetics was 2.14 +/- 1.70%, whereas that in controls was 1.65 +/- 0.47%. Furosine value of the nail in diabetics was 6.67 +/- 3.30%, whereas that in controls was 4.16 +/- 1.62%. Furosine value of the hair in diabetics was 1.30 +/- 1.11%, whereas that in controls was 1.29 +/- 1.71%. Close correlations were detected between HbA1 (glycosylated hemoglobin) and furosine of the nail (r = 0.58, p less than 0.001), HbA1 and furosine of the skin (r = 0.48, p less than 0.001), and HbA1 and furosine of the hair (r = 0.43, p less than 0.01); however, poor correlations were found between furosine of the hair and the skin (r = 0.35, p less than 0.05) and furosine of the nail and the hair (r = 0.33, p less than 0.05). Furosine of the nail was significantly correlated with the FBS (fasting blood sugar) of the same time, previous 6, and previous 12 months. Furosine value of the nail, we believe, is the most useful indicator for evaluating long term control of diabetics and may provide useful information for management of diabetic complications.

Adult↗
PubMed1989

[Clinical signification of localization of S protein and late components in the skin from lupus patients].

We studied frozen tissue of lesional skin and normal-appearing skin from SLE patients and DLE patients by immunofluorescence. S-protein and late components (C5, C7, C9) were localized at the dermal-epidermal junction of the lesional skin from SLE and DLE patients. All specimens of normal-appearing skin from patients with SLE were free of deposits of S-protein and late components. These results suggest that late components may play a role in the development of skin lesions of SLE and DLE.

Adult↗