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Biomedical subjects

Y Bando

Publications and source records attributed to Y Bando.

At least 55 records · Page 3Linked to original sources
PubMed1991

Characterization of specific T helper cell activity in mice bearing alloantigenic tumors in the anterior chamber of the eye.

P815 tumor cells injected in the anterior chamber (AC) of eyes of BALB/c mice elicit anterior chamber-associated immune deviation (ACAID) whereby delayed-type hypersensitivity (DTH) responses to the tumor-associated antigens are suppressed, precursors of cytotoxic T cells are clonally expanded but not terminally differentiated, and levels of tumor-specific serum antibodies are elevated. These results imply the presence of unique helper T (Th) cell functions in these animals. To identify and describe these cells, we first determined the presence of antigen-activated lymphocytes in AC tumor-bearing mice, as well as mice that received tumor cells subconjunctivally (SC), as measured by proliferative responses of lymphocytes from draining lymph nodes and spleens. In addition, we examined the lymphokine secretion profiles [interleukin (IL) 2, IL 4] of antigen-responsive lymph node and spleen cells in limiting dilution analysis. We found that lymphoid organs of mice primed by the SC route contained high frequencies of antigen-reactive CD4+ cells that secreted IL 2 only, or IL 2 plus IL 4. In addition, IL 2-secreting CD8+ cells were found. Alternatively, the lymphoid organs of mice receiving AC inoculations of P815 cells contained CD4+ as well as CD8+ cells that secreted IL 2 after antigen stimulation. However, no IL 4-secreting cells were found. According to a recent model of differentiation of CD4+ T cells, precursors of Th cells (that secrete IL 2 alone) differentiate into Th0 cells that can secrete IL 2, IL 4 and IFN-gamma. These cells further differentiate into Th1 cells and Th2 cells that secrete IL 2 or IL 4, respectively. We interpret the absence of IL 4-secreting CD4+ cells in AC tumor bearing mice to mean that in these mice precursor Th cells are unable/prevented from differentiating into Th0 cells.

Animals↗
PubMed1991

Recurrent perforations of viscus due to ventriculoperitoneal shunt in a hydrocephalic child.

In this report, we describe the first case of recurrent perforations of viscus due to ventriculoperitoneal shunt for the treatment of hydrocephalus. Based on our own experience and a survey of literature, we suggest that perforation of the gastrointestinal tract should be suspected in patients with ventriculoperitoneal shunt, particularly when abdominal symptoms or ventriculitis are presented. To manage this complication, at the first perforation in the present case, a fibrin sealant was effective for closure of the perforated stomach wall. At the second perforation, when laparotomy was performed, we could not find any abnormality in the abdominal cavity except for a sheath and slight omental adhesions near it.

Cerebrospinal Fluid Shunts↗
PubMed1991

Mechanisms of generation of oxygen radicals and reductive mobilization of ferritin iron by lipoamide dehydrogenase.

The oxidase reaction of lipoamide dehydrogenase with NADH generates superoxide radicals and hydrogen peroxide under aerobic conditions. ESR spin trapping using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to characterize the oxygen radical species generated by lipoamide dehydrogenase and the mechanism of their generation. During the oxidase reaction of lipoamide dehydrogenase, DMPO-OOH and DMPO-OH signals were observed. The DMPO-OOH signal disappeared on addition of superoxide dismutase. These results demonstrate that the DMPO-OOH adduct was produced from the superoxide radical generated by lipoamide dehydrogenase. In the presence of dimethyl sulfoxide, a DMPO-CH3 signal appeared at the expense of the DMPO-OH signal, indicating that the DMPO-OH adduct was produced directly from the hydroxyl radical rather than by decomposition of the DMPO-OOH adduct. The DMPO-OH signal decreased on addition of superoxide dismutase, catalase, or diethylenetriaminepentaacetic acid, indicating that the hydroxyl radical was generated via the metal-catalyzed Haber-Weiss reaction from the superoxide radical and hydrogen peroxide. Addition of ferritin to the NADH-lipoamide dehydrogenase system resulted in a decrease of the DMPO-OOH signal, indicating that the superoxide radical interacted with ferritin iron.

Catalase↗
PubMed1991

Hepatocytes enhance neurite regeneration and survival from transected nerve terminals.

The culture of hepatocytes dissociated from adult mice by the collagenase perfusion method enables neurons or neuronal tissues to be cultured with hepatocytes or in hepatocyte-conditioned media. Co-culture with hepatocytes or hepatocyte-conditioned media enhances neurite regeneration and their survival from nerve-transected terminals of dorsal root ganglia with nerve fibers dissected from adult and aged mice. Hepatocytes secrete a factor which enhances not only neurite regeneration but also neurite survival. Activities of other known neurotrophic factors were not as crucial as those of the hepatocyte-conditioned medium, suggesting that this factor may differ from other trophic ones.

Age Factors↗
PubMed1991

Anticarbamazepine antibody induced by carbamazepine in a patient with severe serum sickness.

Anticarbamazepine antibody was detected in a patient who had clinical signs of serum sickness induced by carbamazepine. Skin rash, fever, oedema, and lymphadenopathy are classic signs of severe adverse reaction, but although immunological hypersensitivity is thought to be a contributory factor, the presence of anticarbamazepine antibody has not previously been reported to our knowledge.

Animals↗
PubMed1990

Enhanced efficiency of cell hybridization by neuraminidase treatment.

Cell hybridization techniques have already been utilized, but the outcome is usually not very stable. In order to achieve high stability we tried to achieve closer intercellular contact. Neuraminidase treatment was used to remove sialic acid from the cell membrane, since sialic acid usually prevents close contact between B cells and myeloma cells. After neuraminidase treatment, not only mouse-mouse hybridization but also human-mouse hybridization produced significantly more clones. Our results indicate that neuraminidase treatment is a useful method for generating hybridomas efficiently.

Animals↗
PubMed1990

Superoxide-mediated release of iron from ferritin by some flavoenzymes.

NADH-lipoamide dehydrogenase mobilized iron from ferritin under aerobic conditions. Superoxide dismutase strongly inhibited this mobilization, indicating that the superoxide radical is generated by the enzymatic reaction and release iron from ferritin. Addition of lipoamide as an electron acceptor to NADH-lipoamide dehydrogenase increased the release of iron from ferritin and this release was partially inhibited by superoxide dismutase. Similarly, addition of menadione (2-methyl-1, 4-naphthoquinone) as an electron acceptor to xanthine-xanthine oxidase promoted the release of iron from ferritin and this release was strongly inhibited by superoxide dismutase. These results suggest that dihydrolipoamide and semiquinone of menadione can react with oxygen to form the superoxide radical that mediates release of iron from ferritin.

Animals↗
PubMed1989

Lens protein glycation and the subsequent degree of opacity in streptozotocin-diabetic rats.

We measured how much glycated protein there was in rat eye lenses with different degrees of cataract, using an antibody against glucitol-lysine. Streptozotocin-diabetic (STZ) rats were in some cases treated with insulin (STZ + INS); control rats were normal. We graded the cataracts from 0 (transparent) to 3 (entirely opaque). STZ rats had significantly more grade 3 cataracts, and STZ + INS rats more grade 1 cataracts, than other groups. Grade 3 lenses had significantly more glycated protein than those of grade 0 (10.8 +/- 2.7 vs. 1.0 +/- 0.4 nmol/mg protein), grades 1 and 2 being intermediate. Glycosylated hemoglobin levels correlated similarly with severity of cataract. These data are consistent with the greater incidence of cataract among diabetics than among non-diabetics, and suggest that lens protein glycation contributes to the development of cataract.

Animals↗
PubMed1989

[Analysis of P-glycoprotein in patients with acute leukemias by flow cytometry].

The identification of a P-glycoprotein product of multidrug-resistant gene (mdr 1) was reported recently. To examine the expression of the P-glycoprotein in acute leukemias of various types, we have prepared leukemic blast cells from patients and measured their positivity of P-glycoprotein using monoclonal anti-P-glycoprotein antibody (C219) by flow cytometry. P-glycoprotein is expressed in 8 out of 44 cases including leukemic blast cells but not lymphocytes and monocytes. In these cases showed drug resistance was shown clinically. In addition, the expression of the P-glycoprotein was not observed in the drug-sensitive cases and at the time of initial chemotherapy. Our results suggest that measurement of P-glycoprotein in acute leukemias by flow cytometry may prove to be a valuable tool for the design of chemotherapy protocols.

ATP Binding Cassette Transporter, Subfamily B, Mem↗