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T Hamano

Publications and source records attributed to T Hamano.

At least 19 recordsLinked to original sources
PubMed1992

Yolk vitronectin. Purification and differences from its blood homologue in molecular size, heparin binding, collagen binding, and bound carbohydrate.

This is the first report on a unique vitronectin molecule, yolk vitronectin, which is similar to its blood homologue in cell spreading activity but different in molecular size, bound carbohydrate, and heparin and collagen binding activity. Yolk vitronectin was purified 2,500-fold from chick egg yolk by a combination of hydroxylapatite, DEAE-cellulose, and anti-vitronectin-Sepharose column chromatographies. In SDS-polyacrylamide gel electrophoresis under reducing conditions, yolk vitronectin was separated into 54- and 45-kDa bands, which are 16 and 25 kDa smaller, respectively, than the 70-kDa major band of chick blood vitronectin. The 54-kDa band shares the same NH2-terminal sequence as chick blood vitronectin. In contrast, the NH2-terminal sequence of the 45-kDa band is somewhat homologous with the internal sequences of mammalian vitronectins beginning at the 50th amino acid from the NH2 terminus. The bound carbohydrate of the 54- and 45-kDa species of yolk vitronectin is similar to, but distinct from, that of blood vitronectin. Unlike blood vitronectin, yolk vitronectin cannot bind to either heparin or collagen.

Amino Acid Sequence↗
PubMed1992

Heat and autoclave resistance of cell-spreading activity of vitronectin.

We have investigated the heat- and autoclave-resistant properties of the cell-spreading activity of vitronectin, a cell-spreading glycoprotein in animal blood plasma. Vitronectin heated at 100 degrees C for 10 min or autoclaved at 121 degrees C at 1.2 kg/cm2 for 20 min retained the same cell-spreading activity as native vitronectin. In contrast, fibronectin and type-I collagen treated in the same way lost their activity almost completely. GRGDSP remarkably inhibited the cell-spreading activity of native, heated and autoclaved vitronectins. GRGESP did not inhibit the activity of native vitronectin, but, unexpectedly, partially inhibited the activity of both heated and autoclaved vitronectins. In SDS-polyacrylamide gel analysis under reducing conditions, vitronectin heated at 100 degrees C migrated mainly as a monomer, but autoclaved vitronectin migrated at both the top and front of the gel instead of at the position of the monomer. The change in molecular size during the heat- and autoclave treatments was partially prevented by adding 10 mM dithiothreitol or 2% 2-mercaptoethanol to the protein solution.

Amino Acid Sequence↗
PubMed1992

Direct interaction between an antigen-specific B cell clone and an MHC class II-reactive helper T cell clone.

TP67.14 established by somatic hybridization is a 2,4,6-trinitrobenzenesulfonic acid (trinitrophenyl, TNP)-specific B cell clone with a receptor molecule for TNP on the cell membrane, and MS202 is an interleukin-2 (IL-2)-dependent T helper (Th) cell clone reactive to auto-MHC class II antigens (IAk and IEk) as previously reported. In the present study it was shown that MS202 considerably induced the maturation of TP67.14 into anti-TNP plaque-forming cells (PFCs), and this response was markedly augmented by the addition of TNP-keyhole limpet hemocyanin (KLH). Recombinant cytokines and the culture supernatant of MS202 with TP67.14 did not affect the generation of anti-TNP antibodies by TP67.14. Also, neither anti-IL-4 nor anti-IL-5 monoclonal antibody (mAb) inhibited the maturation of TP67.14 mediated by MS202. The differentiative effect of MS202 on TP67.14 was completely lost when each cell was separately cultured using a semipermeable membrane. Monoclonal antibodies against LFA-1 beta molecules significantly blocked the development of anti-TNP PFCs induced by MS202, as well as anti-IAk and anti-IEk mAbs. Interestingly, the plasma membrane-enriched fraction (PM) derived from MS202 exhibited much more differentiative effects on TP67.14 treated with TNP-KLH than PM from other T cell lines and concanavalin A-induced T lymphoblasts. In addition, TNP-conjugated PM from MS202 by itself induced a great number of anti-TNP PFCs. The present findings indicate that MS202 is capable of inducing the maturation of TP67.14, which is considered to represent a population of B cells with antigen specificity in a late lineage of B cell maturation, through direct cell contact but not soluble factors. This suggests that B cells with antigen specificity, in the presence of antigen, can be induced to mature into antibody-secreting cells through direct contact with Th cells; in this process surface major histocompatibility complex class II and lymphocyte function-associated antigen 1 (LFA-1) molecules are directly involved and the cell membrane derived from Th cells provides a transductional signal for maturation of B cells with antigen specificity in the presence of antigen.

Animals↗
PubMed1992

Functional role of self IA molecules in polyclonal B cell activation using an autoreactive B cell clone derived from (NZB X NZW) F1 mice.

The mechanism of polyclonal B cell activation in autoimmune diseases was investigated by using an autoreactive B cell clone established by somatic hybridization with B cells derived from NZB X NZW (B/W) F1 mice. Briefly, splenic B cells from B/W F1 mice were fused with M12.4.1, a mutant of a B cell line, in the presence of polyethylene glycol and DMSO. NW47.7, a subclone of a resulting hybridoma, expresses B cell surface antigens on the cell membrane, namely IAd, IgM, B220, the receptors for the C3 fragment of complement (C3R), and the Fc portion of IgG (Fc gamma R). It also possesses a receptor molecule for mouse red blood cells treated with bromelain (Br-MRBC) on its surface, by rosette-forming assay with Br-MRBC. In contrast, parental M12.4.1 does not express IAd and IgM on the cell membrane, and does not bind to Br-MRBC under the same conditions. Thus, it is likely that NW47.7 may be an autoreactive B cell clone specific for Br-MRBC. Interestingly, NW47.7 was induced to generate a significant number of IgM-secreting cells when treated with Br-MRBC and rIL-5. Furthermore, mAb against IAd molecules, but not IAk and KdDd, markedly inhibited the differentiative effect of polyclonal activators such as LPS and rIL-5. Also, when MHC identical irradiated B cells were added to the culture of NW47.7 as a stimulator, the induction of IgM-producing cells was greatly augmented, but this augmenting effect was lost by interfering with direct contact of NW47.7 cells with stimulator B cells using a semipermeable membrane, as well as by the addition of mAb against IAd molecules. In addition, irradiated NW47.7, but not M12.4.1, by itself could enhance the secretion of IgM by NW47.7 as a stimulator, but this enhancing effect markedly decreased in the presence of anti-IAd mAb. The present results suggest that surface IA molecules on B cells are involved during the differentiative response to polyclonal activators, and may directly provide a differentiative signal for maturation of B cells into IgM-secreting cells.

Animals↗
PubMed1992

Physarum vitronectin-like protein: an Arg-Gly-Asp-dependent cell-spreading protein with a distinct NH2-terminal sequence.

A 70-kDa protein cross-reacted with anti-bovine vitronectin was isolated from slime mold Physarum polycephalum. The NH2-terminal amino acid sequence of the protein, referred to as Physarum vitronectin-like protein, did not share any homology with those of animal vitronectins. It had cell-spreading activity, which was specifically inhibited by an Arg-Gly-Asp (RGD)-containing peptide.

Amino Acid Sequence↗
PubMed1992

Enzymic method for the spectrophotometric determination of choline in liquor.

A sensitive spectrophotometric method for the determination of choline in liquor is described. The method involves the conversion of choline into formaldehyde by sequential enzymic reactions (choline oxidase and catalase), followed by the formation of a chromophore with 4-aminopent-3-en-2-one. The calibration graph was linear in the range 0.4-15 micrograms cm-3 of choline. The relative standard deviation at 5 micrograms cm-3 of choline was 1.3%. There was no interference from most of the common ingredients of liquor. More than 95% of choline added at two levels was recovered from real samples. The method is simple, and the detection limit was 2 micrograms g-1 when 5 g of sample were assayed.

Alcohol Oxidoreductases↗
PubMed1992

[Migrant sensory neuritis--electrophysiological and pathological study].

Migrant sensory neuritis, which was first proposed by Wartenberg, is very uncommon and only a few case reports have ever been published. We described one case of migrant sensory neuritis and discussed the pathogenesis of this disease. A 44-year-old man noticed numbness in the lateral aspect of the dorsum of the left foot in February 1985. Physically, there was hypoesthesia in the region of left sural nerve with positive Tinel's sign. During the next 4 years, pain, tingling sensation or hypoesthesia appeared in the regions of the right superficial radial nerve, right axillary nerve, left intercostal nerve, left lateral plantar nerve, digital nerve of the right second digit, left saphenous nerve, right superficial peroneal nerve, left superficial radial nerve, bilateral ulnar nerves and bilateral median antebrachial cutaneous nerves one after another in a migrating fashion. Tinel's sign was also positive at the right superficial radial nerve. In some occasions, decreased deep tendon reflexes were observed, but there had been no muscle weakness. Some nerves showed complete recovery, but others showed persistent involvement. Some nerves were affected repeatedly. Laboratory examination failed to clarify underlying disease except for mild liver dysfunction. Electrophysiological study showed reduced amplitude of the sensory nerve action potential (SNAP) of right sural nerve, left ulnar nerve, right superficial radial nerve and digital branch of right median nerve with preserved sensory nerve conduction velocity. SNAP of left sural nerve was absent. These findings mean the cause of the sensory disturbance is axonal degeneration rather than segmental demyelination. There were no abnormalities in motor nerve conduction study.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1991

Membrane fluidity and lipid hapten structure of liposomes affect calcium signals in antigen-specific B cells.

Antigen-specific B-cell clones directed against a 2,4,6-trinitrophenyl (TNP) hapten have been established [Hamano et al. (1990) J. Immunol. 144, 811-815]. We measured here the cytosolic free calcium ion concentration ([CA2+]i) in these B-cell clones after antigen stimulation. Trinitrophenylated liposomes with different length spacers between TNP and phosphatidylethanolamine (TNP-Cn-PE) increased cytosolic free calcium concentration in TNP-specific B cells (clone TP67.21). The magnitude of calcium signals depended on the length of the spacer. TNP-C6-PE in dipalmitoylphosphatidylcholine (DPPC) liposomes triggered larger calcium signals in B cells than TNP-Cn-PE with n = 0, 4, 8, or 12. The magnitude of the calcium signals was strongly dependent on the fluidity of the liposome membranes. TNP-C6-PE in the solid DPPC liposomes triggered the calcium signals in B cells 50-100 times as efficiently as TNP-C6-PE in the fluid dimyristoylphosphatidylcholine liposomes. The difference between the solid liposomes and the fluid liposomes was more pronounced in triggering calcium signals in B cells than in antibody binding to these liposomes.

Animals↗
PubMed1991

Effects of dietary pantethine levels on contents of fatty acids and thiobarbituric acid reactive substances in the liver of rats orally administered varying amounts of autoxidized linoleate.

The effects of dietary pantethine levels on the contents and compositions of fatty acids and on the levels of lipid peroxides were investigated with rat liver and its S-9 fraction under administration of 0 (non), 0.2 (low dose), and 0.35 ml (high dose) of autoxidized linoleate (AL) per 100 g body weight of the rats per day for 5 days. AL having 800 meq/kg of peroxide value (PV) and 1,700 meq/kg of carbonyl value (CV) was dosed to the rats of each group given drinking water containing 0 mg% (deficient), 6.25 mg% (adequate), and 125 mg% pantethine (excess). In the pantethine-deficient and -adequate groups, the contents of fatty acids both in the liver homogenate and in the S-9 fraction were correspondingly decreased by increasing dose levels of AL, and the decrease was remarkable especially in the pantethine-deficient group, but was not significant in the pantethine-excess group even by a high dose of AL. Particularly, in the high dose of AL, the notable decreases of oleic acid (C18:1) contents in both the liver and the S-9 fraction were observed in rats of the pantethine-deficient and -adequate groups. The thiobarbituric acid (TBA) values in the liver homogenate and the S-9 fraction were increased correspondingly by increasing dose levels of AL, and the increases were repressed in the pantethine-excess group.

Administration, Oral↗
PubMed1991

[Treatment of focal dystonia with botulinum toxin].

We have studied the effect of botulinum toxin in patients with focal dystonia, not responding sufficiently to medical therapy. Injection of 5-100 units to the muscles, selected by EMG and clinical examination, invariably resulted in reduction of muscle tonus, although to a different degree depending on the dosage. The outcome after the first trial was best when dealing with small muscles in patients with blephalospasm or Meige's syndrome. In contrast, several attempts were required for the treatment of a large muscle as in torticollis, or multiple muscles as in writers' cramps. The effect lasted 1-3 months. With precise selection of the affected muscles and careful regulation of necessary dosages, this type of therapy may contribute to the treatment of focal dystonia.

Adult↗
PubMed1990

Direct involvement of surface IA/E molecules during B cell maturation using an antigen-specific B cell clone.

TP67.14 is a subclone of a resulting B cell hybridoma established by somatic hybridization between splenic B cells of A/J mice immunized with TNP-LPS and 2.52 M, a HAT medium-sensitive mutant of a B cell line; it expresses IgM, B220, IAk, and IEk on the cell membrane and also possesses a receptor molecule for TNP on its surface derived from TNP-reactive B cells of A/J mice used for cell fusion. As shown previously, TP67.14 could be induced to generate a significant amount of anti-TNP antibodies when treated with TNP-conjugated protein such as TNP-BSA and TNP-keyhole limpet hemocyanin without T cell help as well as LPS. Our study was undertaken to investigate direct involvement of surface MHC class II molecules on B cells during B cell maturation by analysis with this Ag-specific B cell clone. The data demonstrate that mAb against IAk and IEk molecules, but not IAd and H-2k, markedly inhibited the differentiative effects of LPS on TP67.14. In contrast, both antibodies specifically augmented the secretion of anti-TNP antibodies by TP67.14 treated with TNP-BSA, although these antibodies alone failed to induce the generation of anti-TNP antibodies. Interestingly, TP67.14 significantly differentiated into anti-TNP antibody secreting cells when incubated with TNP-conjugated monoclonal anti-IAk or anti-IEk antibodies alone; this differentiative effect was much greater than that of TNP-conjugated anti-IAd mAb or purified mouse IgG under the same conditions. Our result suggests that surface IA/E molecules on B cells may be directly involved in a transductional signal for B cell maturation mediated by the cross-linkage of receptor molecules on B cells with Ag.

Animals↗
PubMed1990

Distribution of lipid microspheres incorporating prostaglandin E1 to vascular lesions.

The intravascular distribution of 0.2 mu lipid microspheres (LM) containing prostaglandin E1 (lipo-PGE1) injected intravenously in spontaneously hypertensive rats (SHR) and arteriosclerotic rabbits was investigated by electron microscopic observation and quantification of radiolabelled compounds. LM were observed under an electron microscope to concentrate in subendothelial space of vascular walls, particularly in vascular lesions associated with hypertension or arteriosclerosis. Radiolabelled lipo-PGE1 accumulated more densely in the vascular walls than did free PGE1, and the difference was more conspicuous in vascular lesions. This indicates that lipo-PGE1 penetrates vascular endothelium and then accumulates in blood vessels to result in augmentation of the pharmacological action of prostaglandin. These findings suggest the usefulness of LM as a carrier of prostaglandin to vascular lesions.

Alprostadil↗
PubMed1990

Enzymic method for the spectrophotometric determination of aspartame in beverages.

A sensitive spectrophotometric method for the determination of aspartame in beverages is described. The method involves the enzymic conversion of aspartame into formaldehyde by the alpha-chymotrypsin-alcohol oxidase system, followed by the formation of a chromophore with 4-aminopent-3-en-2-one. The calibration graph was linear in the range 2.0-30.0 micrograms ml-1 of aspartame. Many common ingredients of beverages do not interfere with the proposed method. The method was applied to the determination of the aspartame content of various real samples, and the results obtained were compared with those given by high-performance liquid chromatography.

Aspartame↗
PubMed1990

[Multifocal demyelinating polyneuropathy with persistent conduction block (Lewis-Sumner syndrome)].

Multifocal demyelinating neuropathy with persistent conduction block (Lewis-Sumner syndrome) is a variant of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), which often clinically simulates a motor neuron disease (MND). We report here three patients initially suspected to have MND, who later were diagnosed as a Lewis-Sumner syndrome. One of them showed a remarkable clinical improvement after immunoglobulin therapy. The definitive diagnosis of this syndrome rests upon nerve conduction studies, uncovering multiple sites of persistent conduction block. Technically, it is important to exclude insufficient stimulus which may lead to an erroneous impression of conduction block. Magnetic stimulation, as compared to electric current, elicited larger responses possibly because of deeper current penetration. We found this mode of stimulation useful especially in testing focal demyelination requiring full activation of a diseased nerve at a most proximal segment.

Adult↗
PubMed1989

Establishment of a bromelain-treated isologous red blood cell reactive B cell clone by somatic hybridization.

Splenic B cells of BALB/c mice were fused with 2.52M, a mutant of a B cell line, in the presence of polyethylene glycol and dimethyl sulfoxide. AT73.14 a subclone of a resulting hybridoma, expresses B cell surface antigens on the cell membrane, namely IAd, IgM, B220, and receptors for C3 fragment of complement (C3R), the Fc portion of IgG (Fc gamma R), and interleukin 2 (IL-2R). It also possesses a receptor molecule for mouse red blood cells treated with bromelain (Br-MRBC) on its surface, by rosette-forming assay with Br-MRBC. In contrast, parental 2.52M does not express IAd on the cell membrane and does not bind to Br-MRBC on the same conditions. Thus, it is likely that AT73.14 may be an autoreactive B cell clone specific for Br-MRBC. Interestingly, AT73.14 could generate a significant number of IgM-secreting cells when treated with Br-MRBC; this was followed by a marked decrease in the expression of B cell surface markers on the cell membrane. In addition, this differentiative response of the cells greatly augmented in the presence of B151-TRF, a B cell differentiation factor, although B151-TRF alone showed only a marginal effect on the generation of IgM-secreting cells. The result suggests that this kind of an autoreactive B cell clone may provide a good model for the study on the mechanism of autoimmune responses.

Animals↗
PubMed1989

[Dynamics of atmospheric pressure under the maxillary complete denture. 1. Relations between the denture retention and the atmospheric pressure].

Dynamics of atmospheric pressure under the maxillary complete denture, and their relations with the denture retention influenced by the factors such as the denture seating force, the saliva viscosity and the postdamming, were investigated on the simulation models. The following results were obtained. 1. The atmospheric pressure under the denture became higher than the external one by the denture insertion, and increased during the denture seating, and decreased by the removing force of denture and furthermore became lower than external one by continuous application of its force, and at all became equal to the external one when the denture separated from the basal seat. 2. Greater seating force brought about greater positive pressure and less negative pressure. 3. Higher viscosity of saliva and the postdamming brought about greater positive and negative pressures. 4. Both of greater seating force and higher viscosity of saliva brought about greater retentive force. 5. The postdamming was useful for the maxillary posterior border seal. 6. The atmospheric pressure under the denture base seems not to relate directly to the maxillary denture retention in the static condition but to reveal the status of peripheral seal.

Atmospheric Pressure↗
PubMed1989

[Penetrating keratoplasty and cataract surgery].

Of 46 eyes undergoing simultaneous penetrating keratoplasty and cataract extraction, 25 grafts (54%) remained clear with an average follow-up of 37 months. This low success rate can be party explained by the fact that more than 50% of our patients had unfavourable ocular conditions preoperatively. In case of simultaneous procedures, methods of cataract extraction (ICCE or ECCE) did not have any significant affect on the rate of clear grafts. In eyes with favourable ocular conditions preoperatively, the rates of clear grafts were similar (approximately 75%) in cases of simultaneous operation (21 eyes) and separate operation (8 eyes).

Adult↗