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Biomedical subjects

T Hamano

Publications and source records attributed to T Hamano.

At least 127 records · Page 7Linked to original sources
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↗
PubMed1988

Functional analysis of an Epstein-Barr virus-nontransformed human B cell line.

A human B cell line, IW.2, was established from the culture of peripheral blood lymphocytes of a patient with chronic lymphocytic leukemia. IW.2 was shown to express IgM, B1 (CD20), and 12 (a major histocompatibility complex class II antigen) molecules on the cell membrane by analysis of flow microfluorometry (FMF) as well as a receptor for the third component of complement (C3R), but not to express an Epstein-Barr virus nuclear antigen. The cell growth of IW.2 was markedly inhibited when treated with either B cell stimulatory factor from phytohemagglutinin-conditioned medium or 12-O-tetradecanoylphorbol-13-acetate. Interestingly, IW.2 cells were capable of generating a significant amount of both IgM and IgG at the same time when stimulated with these reagents, followed by a decrease in the expression of IgM, B1, and I2 molecules on the cell membrane as well as C3R. The results suggest that IW.2 cells may be a model for the study of the maturation of human B cells.

Antibody-Producing Cells↗
PubMed1988

Corneal endothelial changes associated with herpetic stromal keratitis.

Wide-field specular microscopy was performed on both eyes of 33 patients with unilateral herpetic stromal keratitis. Endothelial changes were quantitated by computerized morphometric analysis of individual cells. In the 16 patients with disciform keratitis, the corneal endothelium of the affected eyes showed no difference in cell density but demonstrated significant increases of variation in cell size (polymegathism) and shape (pleomorphism) when compared to the cells in the fellow unaffected eyes. The eyes with keratouveitis (17 patients), however, had marked polymegathism and pleomorphism of the endothelium and a distinctly lower endothelial cell density (mean, 19%) than the healthy fellow eyes.

Adolescent↗
PubMed1987

Determination of hydrogen peroxide in beverages by high-performance liquid chromatography with fluorescence detection.

A high-performance liquid chromatographic method is described for the determination of hydrogen peroxide in beverages. The method involves the enzymatic conversion of hydrogen peroxide into formaldehyde by catalase-methanol, followed by the derivatization of formaldehyde with 4-amino-3-penten-2-one. The reaction was carried out under the flow of nitrogen, which allows the detection of hydrogen peroxide without interference from reducing substances such as ascorbic acid. More than 90% of hydrogen peroxide spiked at the 2 ppm level was recovered from several beverages. The method exhibits good linearity, accuracy and precision, and the minimum detectable level was 0.05 ppm.

Ascorbic Acid↗
PubMed1987

Establishment of an antigen-specific B cell clone by somatic hybridization.

Splenic B cells of A/J mice immunized with 2,4,6-trinitrophenyl (TNP)-lipopolysaccharide were fused with 2.52M, a mutant of a B cell line, in the presence of polyethylene glycol and dimethyl sulfoxide. TP67.21, a subclone of a resulting hybridoma, expresses IAk, IEk, IgM, B220, P50, and receptors for C3 fragment of complement, the Fc portion of IgG, and interleukin 2 receptor on the cell membrane; it also possesses receptor molecules for TNP on its surface, derived from TNP-reactive B cells of A/J mice primed with TNP-lipopolysaccharide used for somatic hybridization, by a rosette-forming assay with TNP-sheep erythrocytes. In contrast, parental 2.52M lacks IAk and IEk on the cell membrane and does not bind to TNP-sheep erythrocytes under the same conditions. Thus, it is likely that TP67.21 is an antigen-specific B cell clone directed against TNP. The antigen binding of cells was markedly inhibited by the specific free hapten or anti-IgM antibodies. Interestingly, TP67.21 was induced to generate a significant amount of anti-TNP antibody when treated with TNP conjugates including T cell-independent and -dependent antigens, such as TNP-lipopolysaccharide, TNP-bovine serum albumin, TNP-ovalbumin, and TNP-keyhole limpet hemocyanine in the absence of T cell help, as well as polyclonal activators; this was followed by a marked decrease in the expression of B cell surface markers on the cell membrane. This suggests that the cross-linkage of receptor molecules on TP67.21 by antigen may directly provide a differentiative signal for maturation to a lineage of B cells, and consequently results in the generation of antigen-specific antibodies without T cell involvement.

Animals↗
PubMed1987

Herpetic keratitis therapy to reduce recurrence.

Since the herpes simplex virus locates latently in the ganglia and is reactivated by certain triggers, the important problem in treatment is to prevent or reduce recurrence. The present study investigates the role of mechanical debridement in lessening the recurrence of dendritic keratitis in patients with herpetic epithelial keratitis. Group A was treated with mechanical debridement plus IDU, Group B with IDU alone. Also studied was the effect of steroid subconjunctival injection on herpetic recurrence in patients with herpetic stromal keratitis: Group C was treated with intravenous infusion of pepsin-treated gamma-globulin (PTGG) and steroid subconjunctival injection, Group D with steroid subconjunctival injection alone and Group E with intravenous infusion of PTGG alone. The recurrence rates of dendritic keratitis were 19% in Group A and 40% in Group B (average follow-up periods: 24 and 25 months). The recurrence rates of stromal keratitis were 61% in Group C, 64% in Group D, and 36% in Group E (average follow-up periods: 20, 19 and 15 months). The difference between Groups D and E was statistically significant (chi 2 test, P less than 0.05). The recurrence rates of dendritic keratitis were 18% in Group C, 21% in Group D and 7% in Group E. In conclusion, mechanical debridement tended to reduce the recurrence of herpetic epithelial keratitis and steroid subconjunctival injection to increase the recurrence of epithelial or stromal keratitis.

Administration, Topical↗
PubMed1986

The kinetic study on cell surface antigens of a hybridoma between human B cells and a mouse B-cell line.

Human B cells obtained from tonsils were fused with a mutant clone of a murine B-cell line in the presence of polyethylene glycol and dimethyl sulfoxide. THT12.58, a subclone of the human-mouse B-cell hybridoma, was shown to express human B-cell surface antigens on the cell membrane, namely B1, B2, I2, human IgM and IgD derived from human B cells by analysis of flow microfluorometry (FMF), as well as murine B-cell markers; the amount of these human B-cell markers on THT12.58 did not change for more than 1 year after establishment. Interestingly, the expression of the human B-cell antigens significantly decreased after treatment of the cells with B-cell stimulatory factors (BSF) obtained from the supernatant of the culture of PHA-P activated T cells; this was followed by significant enlargement in cell size compared with the control. A marked decrease in the amount of each antigen on the hybrid was observed when treated with Staphylococcus aureus Cowan I strain (SAC) in addition to BSF. In contrast, the expression of these markers on the cells increased after exposure of the cells to recombinant human interferon-gamma (rINF-gamma). Additionally, the effect of BSF on the generation of IgM-secreting cells by human B cells markedly decreased after absorption of BSF with the hybrid cells. These results suggest that THT12.58 may possess a receptor for BSF on the cell surface, and be capable of differentiating into much more mature stage of B-cell lineage after exposure to BSF. Thus, this kind of a human-mouse B-cell hybridoma with human B-cell differentiation antigens can be a good model to investigate the kinetics of cell surface antigens and characterization of a receptor for BSF on human B cells.

Animals↗
PubMed1985

A new punctum plug.

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Equipment and Supplies↗