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Biomedical subjects

S Sakuragi

Publications and source records attributed to S Sakuragi.

At least 55 records · Page 3Linked to original sources
PubMed1992

Infection of macaque monkeys with a chimeric human and simian immunodeficiency virus.

Two macaque monkeys were inoculated with a chimeric human and simian immunodeficiency virus carrying the tat, rev, vpu and env genes of human immunodeficiency virus type 1. Infectious virus was recovered from one of the monkeys at 2 and 6 weeks post-infection. The hybrid nature of the isolated viruses was verified by Southern and Western blotting analyses. Both of the monkeys infected with the chimera elicited a humoral antibody response against the virus.

Animals↗
PubMed1992

Sequences responsible for efficient replication of simian immunodeficiency virus SIVMND in cells of the monocyte/macrophage lineage.

We determined the susceptibility of monocytic cell lines to infection with viral strains derived from two infectious clones of simian immunodeficiency virus isolated from a mandrill. One of the strains, which replicates poorly in T cell lines, was found to grow more rapidly than the other in these cells. The viral determinant for this property was genetically mapped within the env gene encoding a surface protein. Six amino acid substitutions identified appeared to be located outside of the domains corresponding to human immunodeficiency virus type 1 env functional domains such as the CD4-binding and V3 loop regions.

Animals↗
PubMed1992

[Suppression of interphotoreceptor retinoid-binding protein (IRBP)-induced experimental autoimmune uveitis by pretreatment with anti-idiotypic monoclonal antibody].

In an experimental model of interphotoreceptor retinoid binding protein (IRBP)-induced experimental autoimmune uveitis (EAU) in Lewis rats, EAU onset was suppressed by pretreatment with anti-idiotypic antibody (TRD3). In the pretreated group, the titers of anti-IRBP antibody and idiotypic antibody were lower and the titer of anti-idiotypic antibody was higher than in the control group, and the skin test (DTH) against IRBP was also suppressed. Histopathological findings of the control group showed destruction of retinal outer granular layer, loss of the outer segment and lymphocytic infiltration, although no definite inflammatory signs appeared in the pretreated group. We suppose that the mechanism of idiotypic suppression is via induction of idiotype-specific or idiotype-related suppressor T cells.

Animals↗
PubMed1991

[Production of anti-33kDa protein monoclonal antibody and organ-specificity of 33kDa protein].

We produced monoclonal antibody TS-SC6 specific for 33kDa protein (33K) from bovine retina and studied the localization of 33K in mammalian retinas (rat, mouse, bovine, guinea pig and human) and pineal gland of rat. An immunohistochemical study showed that TS-SC6 reacted with the outer plexiform layer (OPL), outer nuclear layer (ONL) and rod inner segments (IS) in rat, ONL, IS and IS in mouse and guinea pig. It reacted with ONL and rod outer segments (OS) in bovine, ONL and OS in human. Immunoreactivity was seen in the pineal gland, but there was no immunoreactivity in the central nervous system surrounding the pineal gland. Immunoblot analysis was carried out with soluble fractions prepared from the retina, pineal gland, cerebrum, liver, kidney and intestine of rats. TS-SC6 reacted with 33K of the retina and pineal gland, respectively. However, it did not react with soluble fractions from the other tissues.

Aged↗
PubMed1990

Analysis of the human, bovine and rat 33-kDa proteins and cDNA in retina and pineal gland.

A monoclonal antibody (mAb) was produced against a bovine retinal 33-kDa protein. Several clones of 33-kDa protein were isolated from each library of cDNA from human, bovine and rat retinas and rat pineal gland by mAb screening and by hybridization with cDNA probes. Each of the four cDNA sequences was determined and amino acid (aa) sequences were deduced from the nucleotide sequences. The latter were nearly identical in rat retina and rat pineal gland (99.6%) and were similar in human, bovine and rat retina (more than 87%). Each of these cDNAs had one long ORF and encoded 245 or 246 aa. The deduced aa sequences in rat retina and rat pineal gland were virtually identical and the sequences in human, bovine and rat retina were highly homologous (more than 88%). The predicted Mr for each of these proteins was 28,246 in the human, 28,176 in bovine, 28,143 in rat retina, and 28,129 in rat pineal gland. Each of the sequences has a putative site for phosphorylation by A kinase; we have confirmed that the putative site is Ser73. These results show that the 33-kDa proteins in the retina and pineal gland have the same sequences and the same phosphorylation site and suggest that the functional role of this protein is the same in the retina and pineal gland.

Amino Acid Sequence↗
PubMed1990

Isolation and characterization of three distinct 34 kDa EDTA-extractable proteins from bovine lens.

EDTA-extractable protein (EEP) is known to be a major lens membrane protein with a molecular mass in the range 32 kDa to 38 kDa, and is also known to bind to the lens membrane and phospholipid-containing liposomes in a calcium-dependent manner. Recent results (Russell, P., Zelenka, P., Martensen, J., and Reid, T.W. (1977) Curr. Eye Res. 6, 533-538) on antibody cross-reactivity have demonstrated that a 34-35 kDa component of EEP is identical to calpactin I (lipocortin II). In this study, we have identified and purified three distinct 34 kDa components of EEP (designated as EEP-34A1, EEP-34A2 and EEP-34B) from bovine lens that inhibit phospholipase A2 activity. These proteins bind to phospholipid-containing liposome and F-actin in a calcium-dependent fashion. Two-dimensional electrophoresis demonstrates that the three proteins were distinct from one another. However, immunochemical studies and one-dimensional peptide mapping indicate that EEP-34A1 and EEP-34B are very similar. Our results also indicate that EEP-34A1 is very similar to calpactin II and that EEP-34A2 corresponds to calpactin I. The bovine lens 34-35 kDa component of EEP is a mixture of proteins rather than a single protein.

Actins↗
PubMed1990

Identification of the 32 kDa components of bovine lens EDTA-extractable protein as endonexins I and II.

EDTA-extractable protein (EEP) is a mixture of major lens membrane proteins with molecular masses ranging from 32 kDa to 40 kDa. These bind to the lens membrane in a Ca2(+)-dependent manner. In the present study we have identified and purified two distinct 32 kDa components of EEP (designated as EEP 32-1 and EEP 32-2) from bovine lens that inhibit phospholipase A2 activity. Both EEP 32-1 and EEP 32-2 bind to phospholipid-containing liposomes and actin filaments in a Ca2(+)-dependent fashion. Immunochemical studies and two-dimensional electrophoreses demonstrate that the two proteins are distinct from one another. Both EEP 32-1 and EEP 32-2 are clearly different from calpactin (lipocortin) or its proteolytic fragments because they did not react with anti-[human placenta calpactin (lipocortin)] antibody. Our results also indicate that EEP 32-1 is very similar to endonexin I and that EEP 32-2 corresponds to endonexin II.

Actins↗
PubMed1989

[Research in similarities between EEP34 and lipocortin].

EDTA-extractable protein (EEP) is a major extrinsic protein of lens fiber membrane. The EEP of calf lens separated three major bands by SDS-PAGE, and the molecular weights of these major bands were 34 kilodalton (kd.), 33 kd. and 32 kd. Combination of EEP with F-actin and some kinds of phospholipid containing liposomes depends on Ca2+. In two-dimensional gel electrophoresis, some spots of the calf-EEP partially overlapped with spots of lipocortin, which is a substrate for epidermal growth factor receptor/kinase and an inhibitor of phospholipase A2. The 34 kd. protein of the EEP cross-reacted to the antibody prepared against lipocortin of pig's aorta: These results suggest the important function of EEP in lens.

Animals↗
PubMed1989

[Biochemical and immunological properties of EEP 32 kd protein].

EDTA-extractable protein (EEP) is a major extrinsic protein of lens membrane. EEP is composed of two major polypeptides on SDS-PAGE with apparent molecular weights of 32 kilodaltons (kd) and 34 kd. Recently it has been reported that the 34 kd protein of the EEP cross-reacted with the antibody prepared against lipocortin, an inhibitor of phospholipase A2. We have purified and characterized the 32 kd protein of the EEP (EEP 32). Crude EEP of bovine lens was applied to a Q-Sepharose column and eluted with a linear gradient system composed of 0-0.7 M NaCl. The EEP 32 was discreted at salt concentrations of approximately 0.1-0.25 M (EEP 32-A) and 0.35-0.4 M (EEP 32-B). Both EEP 32-A and EEP 32-B interact with phospholipid and F-actin in a Ca2+-dependent manner as lipocortin. Furthermore, the EEP 32-A, a major component of the EEP 32 purified by hydroxyapatite chromatography and gel filtration, inhibited phospholipase A2 activity more than lipocortin. On Western blot analysis, the 32 kd lipocortin-like protein of human placenta showed cross-reactivity to EEP 32-B, but not EEP 32-A. These results suggest that EEP 32 contains two lipocortin-like proteins differing in antigenicity and isoelectric points.

Animals↗
PubMed1989

[Biochemical and immunological properties of 34kDa EDTA-extractable protein (EEP34k)].

It has been reported that the 34kDa protein of EDTA-extractable protein (EEP34k) cross-reacted with lipocortin antisera. The lipocortins are a family of proteins that have been reported to inhibit phospholipase A2. Previously, we purified two proteins from EEP34k by anion-exchange chromatography, and referred to them as 34k (A) and 34k (B). On Western-blot analysis, two proteins showed cross-reactivity to both lipocortin I and lipocortin II. In this study, four proteins (34k (A)1, 34k (A)2, 34k (B)1, 34k (B)2) were isolated from 34k (A) and 34k (B), on a cation-exchanged chromatography. By peptide mapping, immunological analysis and SDS/PAGE, we confirmed that 34k (A)1 and 34k (B)2 were identified proteins and these were called lipocortin I, and that 34k (A)2 was lipocortin II. It is concluded that at least two lipocortins, I and II are present in EEP34k. We also observed the presence of phospholipase A2 inhibitory activity in both 34k (A) and 34k (B).

Animals↗
PubMed1989

Establishment of anti-idiotypic monoclonal antibodies against anti-interphotoreceptor retinoid-binding protein monoclonal antibody.

Two monoclonal antibodies (MAbs) against interphotoreceptor retinoid-binding protein (IRBP) were previously established. One of the antibodies designated as MAb-TRA4 reacted with the IRBP of multiple species. Using this MAb-TRA4, 6 clonal anti-idiotypic monoclonal antibodies (MAb-TRDy; y = 1-6) against MAb-TRA4 were established. All of the MAb-TRDy were characterized by ELISA, immunoblotting and immunohistochemical studies. It was shown by ELISA that MAb-TRDy inhibited the specific binding between IRBP and MAb-TRA4 and did not cause nonspecific binding to rat polyclonal immunoglobulins (IgG and IgM). Immunoblotting assay demonstrated that MAb-TRDy inhibited the binding between IRBP and MAb-TRA4. Immunohistochemical examination also confirmed the immunological characterization of MAb-TRDy. Thus the present results indicate that the MAb-TRDy which have been established are the anti-idiotypic MAbs against anti-IRBP MAb-TRA4. MAb-TRDy can be used as a tool to study the pathogenesis of experimental autoimmune uveitis induced by IRBP.

Animals↗
PubMed1988

Wyburn-Mason syndrome: report of a rare case with computed tomography and angiographic evaluations.

A case of Wyburn-Mason syndrome comprising unilateral retinocephalic vascular malformations is reported in a 7-year-old girl presenting with proptosis of the left eye associated with injection of the bulbar conjunctiva. This rare congenital vascular disorder is reviewed in the literature, and in particular the neuroradiological findings are detailed in the presented case.

Cerebral Angiography↗
PubMed1987

Molecular cloning of the S-antigen cDNA from bovine retina.

S-antigen is the major component of the soluble proteins in the retina and the pineal, and is thought to play a regulatory role in the visual cycle. It induces experimental autoimmune uveitis (E.A.U.) in various species of laboratory animals. We have cloned the cDNA of S-antigen from bovine retina, containing the entire coding region, and determined its nucleotide sequence. The sequence consists of a 1212 nucleotide region that specific the amino acid sequence, a 368 nucleotide 5' untranslated region and a 80 nucleotide 3' untranslated region. The previously reported partial amino acid sequence defining the carboxy terminal moiety of the polypeptide, fits into our sequence. Homologies were found between the predicted amino acid sequence of S-antigen and that of alpha transducin.

Amino Acid Sequence↗
PubMed1982

Effects of conjunctival resection on the corneal immune response.

In order to evaluate the effect of perilimbal conjunctival resection on the corneal immune response, we immunized rabbits with either intravenous or topical administration of bovine gamma globulin. After unilateral perilimbal conjunctival resection, the corneas were challenged with intracorneal injections of bovine gamma globulin. Perilimbal conjunctival resection prevented the development of peripheral corneal infiltrates in the rabbits immunized intravenously (P less than .0016) but not in those immunized topically. All the animals developed antibody titers to bovine gamma globulin. Similarly, perilimbal conjunctival resection did not prevent corneal graft rejection in rabbits sensitized to their donors by previous skin grafting.

Administration, Topical↗
PubMed1982

Minocycline in the chemotherapy of murine toxoplasmosis.

The effects of minocycline alone or in combination with sulphadiazine were evaluated against acute murine toxoplasmosis and compared with the efficacy of pyrimethamine and sulphadiazine. The date presented show that mice could be protected from acute toxoplasmosis by minocycline, in spite of using a virulent strain of Toxoplasma gondii, a large inoculum, and a delay in the administration of the drug. Acute toxoplasmic infection in mice could be eradicated by aminocycline--sulphadiazine combination, which was found to be as effective as pyrimethamine--sulphadiazine combination therapy.

Animals↗