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H Hojo

Publications and source records attributed to H Hojo.

At least 91 records · Page 5Linked to original sources
PubMed1992

Immunohistochemical evaluation with Ki-67: an application to salivary gland tumours.

Using Ki-67, a monoclonal antibody, the proliferating capacity of 15 salivary gland tumours, including nine pleomorphic adenomas, four adenoid cystic carcinomas, one mucoepidermoid carcinoma and one acinic cell carcinoma was determined immunohistochemically, using normal salivary gland tissue as a control. The frequency of Ki-67 positive cells was 4.7 percent in the normal salivary gland and one percent in pleomorphic adenomas, whereas the average frequency in malignant tumours was 18.3 percent. Among adenoid cystic carcinomas, the frequency was related to the morphological type; the solid sub-type had the highest frequency of Ki-67-positive cells. As this sub-type is recognized as the most aggressive of these tumours, this technique has the potential of providing an early indication of the clinical behaviour of a tumour.

Carcinoma, Adenoid Cystic↗
PubMed1992

An enzyme immunoassay for cell proliferation using monoclonal antibodies directed against a cell proliferation-associated antigen.

An enzyme immunoassay (EIA) for assessment of cell activation and proliferation was developed by the use of monoclonal antibodies (MoAb) directed against a ubiquitous growth-associated antigen, gp125. Test cells distributed in a microtest plate were labeled with anti-rat gp125 MoAb, B3, for rat cells or anti-human gp125 MoAb, HBJ127, for human cells and subsequently with rabbit anti-mouse immunoglobulins. The cell-bound antibody was assessed by a colorimetric enzyme assay using horse-radish peroxidase-modified protein A and 2,2'-azinobis(3-ethylbenzthiazoline sulfonic acid). To terminate the reaction and to make the reaction mixture transparent, sodium dodecyl sulfate (SDS) was added to the mixture. The intensity of the developed color was measured by use of a multiwell scanning spectrometer. The titration curves obtained by the EIA for cells were practically similar to those obtained by the conventional 3H-thymidine (Tdr) uptake method, and the appropriate cell number to be used for the assay was indicated to be 3 to 50 x 10(3) cells per well. This method was applicable not only for quantitation of cell number of growing cells but also for measuring mitogenic responses of lymphocytes as revealed by the data obtained from Con A stimulation of lymphocytes. These results indicate that this new EIA method using anti-gp125 antibodies is useful for quantitative assays of cell growth and cell activation in the research fields of oncology and immunology.

Animals↗
PubMed1992

Cytokine-related immunopotentiating activities of paramylon, a beta-(1-->3)-D-glucan from Euglena gracilis.

Paramylon, a beta-(1-->3)-D-glucan, isolated from Euglena gracilis, was tested for its adjuvant activity on the antibody response to sheep red blood cell (SRBC) in mice. Paramylon markedly enhanced anti-SRBC plaque-forming cell production at a dose of 10 mg/kg. It was also found that in vitro addition of lipopolysaccharide in culture to macrophages from paramylon-treated mice produced a large amount of interleukin 1 (IL-1) and there was a significant level of interleukin 6 (IL-6) induced transiently in the blood of these mice. As IL-1 and IL-6 play crucial roles in the immune response to T cell-dependent antigens like SRBC, the immunopotentiating effect of paramylon might be expressed through the action of these cytokines.

Adjuvants, Immunologic↗
PubMed1992

Tissue specific induction of metallothionein synthesis by tumor necrosis factor-alpha.

Effect of tumor necrosis factor-alpha (TNF), which is supposed to be one of the mediators responsible for endotoxin, on metallothionein (MT) synthesis was determined in various tissues of rats. At 18 hr after the injection of TNF, MT-I concentrations significantly increased in the liver, lung and heart, but not in the kidney and thymus. In the spleen of TNF-treated rats, MT-I concentrations decreased. Thus, synthesis of MT-I was tissue specific and dose-dependent. In the liver, the synthesis of both metallothionein-I and metallothionein-II was observed and the rate of the induction was greater in the latter. Antioxidative role of the MT synthesized by TNF was discussed.

Animals↗
PubMed1991

Reversal of immune dysfunction in osteopetrotic rats by interferon-gamma: augmentation of macrophage Ia expression and lymphocyte interleukin-2 production and proliferation.

Lymphocytes from osteopetrotic (op) rats, compared to their normal (n) littermates, exhibit defective immune functions associated with their inability to resorb bone. Among these immune defects are the failure of their spleen cells to proliferate normally to mitogens and to generate IL-2. Addition of exogenous IL-2 failed to reverse the suppressed proliferation in the op spleen cells, indicating that additional defects were involved in the suppression. Phenotypic analysis of cellular constituents of op and n spleens revealed that the percentages of T cells, macrophages, and IL-2 receptor positive cells were not different. Furthermore, there was no difference in CD4 (W3/25) and CD8 (OX8) cells. However, the Ia+ (OX3) cells in the op spleen represented less than 50% of those found in the n spleen, but the op had higher levels of transferrin receptor (OX26). On the basis of the ability of interferon-gamma (IFN-gamma) to increase Ia expression, this cytokine was added to op spleen cells (10-50 U/ml) and found to increase the number of Ia+ cells to the level found in n spleen cells. Moreover, pretreatment of op spleen cells with IFN-gamma restored their ability to proliferate to mitogens and their responsiveness to IL-2. Not only did IFN-gamma reverse the defective response to IL-2, but it also augmented the defective IL-2 production by op spleen cells. Taken together, these findings demonstrate that IFN-gamma can reverse many of the impaired immune functions characteristic of op spleen cells in vitro. Furthermore, these data suggest that IFN-gamma may provide an important avenue of treatment in these animals that may contribute to restoration of normal bone resorption.

Animals↗
PubMed1991

Cytotoxicity of bacteriohopane-32-ol against mouse leukemia L1210 and P388 cells in vitro.

To investigate the biological activities of the hopane group of pentacyclic triterpenoids, we isolated one hopanoid, bacteriohopane-32-ol from Rhodopseudomonas palustris and tested its cytotoxicity against mouse leukemia cells in vitro. The IC50 of the hopanoid for L1210 and P388 was 22 and 19 microM respectively. This activity was slightly reduced by co-incubation with cholesterol. As the mechanism of cytotoxic action, disturbances of membrane function and metabolism are discussed.

Animals↗
PubMed1991

Adhesion molecules on murine lymphokine-activated killer cells responsible for target cell killing: a role of CD2.

Lymphokine-activated killer (LAK) cells were induced from C57BL/6 mouse spleen cells and the effects of culture time on the expression of cell surface phenotypes and cytotoxic activity of LAK cells were determined. The expression of CD2 remarkably decreased after culture of LAK cells for 30 days, while LFA-1, a principal adhesion molecule in LAK cells, and CD3 were not changed by the culture. LAK cells cultured for 90 days completely lost CD2. In accordance with the decrease of CD2, the cytotoxic activity of LAK cells declined but a certain leven was retained even after the complete loss of CD2. The established LAK cell clones were also strongly positive for the expression of LFA-1 but negative for CD2. When the LAK cell clones were transfected with the CD2 cDNA, they started to express CD2 on their cell surface and to show greater binding ability and stronger cytotoxicity to target tumor cells. These results indicated that CD2 plays a role as an adhesion molecule responsible for target cell killing in murine LAK cells.

Animals↗
PubMed1991

Pro-peptide as an intramolecular chaperone: renaturation of denatured subtilisin E with a synthetic pro-peptide [corrected].

The amino-terminal pro-sequence consisting of 77 amino acid residues is required to guide the folding of secreted subtilisin E, a serine protease, into active, mature enzyme (ikemura et al., 1987). Furthermore, denatured subtilisin E can be folded to active enzyme in an intermolecular process with the aid of an exogenously added pro-subtilisin E, the active site of which was mutated (Zhu et al., 1989). In this report, we have synthesized the pro-peptide of 77 residues (corresponding to -1 to -77 in the sequence, where residue +1 is the N-terminal amino acid residue of the mature protein), and have found that it could intermolecularly complement the folding of denatured subtilisin E to active enzyme. Furthermore, we have found that the synthetic pro-peptide exhibits specific strong binding to the active mature enzyme by inhibiting it competitively at its active centre with an upper limit to a Ki of 5.4 x 10(-7). In contrast, synthetic pro-peptides corresponding to -44 to -77, -1 to -64 and -1 to -43 inhibited the enzyme with Ki values weaker by two orders of magnitude. The results indicate that the sequence extending from -1 to -77 is essential for specificity of interaction, perhaps generating a conformation that accounts for both roles found hitherto, i.e. specific binding to the active centre, and guiding of the refolding to active enzyme. Thus these results suggest that the pro-peptide functions as an intramolecular chaperone [corrected].

Chaperonins↗
PubMed1991

[Aortic arch replacement by simple hypothermic retrograde cerebral perfusion for long cerebral circulatory arrest--a successful case report].

We have recently discovered that hypothermic cerebral retrograde perfusion can be performed by simply elevating the central venous pressure in Trendelenburg's position during aortic arch surgery. During deep hypothermic perfusion of the lower half of the body with an occlusion balloon in the descending aorta, oxygen saturated venous blood supplied the brain with oxygen. A successful case is reported. A case was 53 y.o. woman of dissecting aortic aneurysm DeBakey type II, with a true aortic arch aneurysm. Under median sternotomy the right atrium and the femoral artery were cannulated for cardiopulmonary bypass. With the brain under retrograde perfusion at a rectal temperature of 16 degrees C and a central venous pressure of 10-15 mmHg, the ascending to the descending aorta was replaced. Blood flowed into the aortic arch from the arch vessels was blackish in color. Brain circulatory arrest time was 81 min. Postoperative course was uneventful. It is suggested that this simple retrograde cerebral perfusion during hypothermic aortic arch surgery protected the brain for an extended brain circulatory arrest time, and eliminated the need for clamping at the aortic arch and the arch vessels, and simplified the operative procedure.

Aortic Dissection↗
PubMed1991

Rossette formation between stromal and hemopoietic cells: a simple assay for the supportive activity of stromal cells.

Hemopoietic stromal cells play an important role in the proliferation and differentiation of hemopoietic cells in vitro. Recently, it has been emphasized that the attachment of hemopoietic cells to stromal cells is the first step in this process and that this is necessary in hemopoiesis in vitro. A rosette formation technique was developed to quantitatively measure this attachment. The murine leukemic cell line ELM-D, which grows only in close contact with stromal cells, was used to represent hemopoietic cells. Rosettes were formed with about 75% of the normal murine bone marrow derived hemopoietic supportive stromal cells (MS-1). However, ELM-D formed rosettes with only 15% of the hemopoietic non-supportive stromal cells (MS-K). The maximum rosette formation was obtained at an ELM-D to MS-1 ratio of 20:1. When MS-1 and MS-K were mixed and seeded as stromal cells, MS-K did not alter the attachments of ELM-D to MS-1; the percentage of rosette formation increased in parallel with the increase in the number of MS-1 cells in the stromal layer. These findings suggest that MS-K does not have an inhibitory effect. Rosette formation is a simple, quantitative technique for assaying the hemopoietic supportive activity of stromal cells in vitro.

Animals↗
PubMed1991

Treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia: a pilot study which raises important questions.

Acute lymphoblastic leukemia (ALL) patients with a Philadelphia chromosome (Ph+ ALL) were treated with a combination of antineoplastic drugs recommended for both myeloid and lymphoid leukemia (BHAC-DMPV: behenoylcytosine arabinoside, daunorubicin, 6-mercaptopurine, prednisolone, and vincristine). Ph+ ALL patients with chromosome breaks which occur within the major breakpoint cluster region (M-BCR rearranged Ph+ ALL) were treated with natural interferon-alpha (IFN-alpha) after entering complete remission. In this study, four of seven patients with Ph+ ALL had M-BCR rearrangement, and all achieved complete remission with karyotypic normalization. Subsequent cytogenetic analysis during complete remission in two ALL patients with M-BCR rearrangement revealed that the percentage of bone marrow cells with the Ph chromosome increased, while the bone marrow maintained remission status. This cytogenetic-hematological discrepancy led us to consider that M-BCR rearranged Ph+ ALL might be a variant of chronic myelogenous leukemia, therefore, three Ph+ ALL patients with M-BCR rearrangement were treated with IFN-alpha after achieving complete remission. In contrast, only one of three patients with M-BCR non-rearranged Ph+ ALL obtained complete remission.

Adult↗
PubMed1990

Cytogenetic findings in adult acute leukemia and myeloproliferative disorders with an involvement of megakaryocyte lineage.

Cytogenetic analyses were performed on 12 adult patients with abnormal megakaryoblastic proliferation which was detected by ultrastructural cytochemical study (platelet peroxidase) and platelet-megakaryocytes-specific monoclonal antibodies (TP-80, Plt1, AN51, and KOR-77). The patients consisted of two patients with myelodysplastic syndromes (MDS), three with acute megakaryoblastic leukemia (AMKL), six with megakaryoblastic transformation in Philadelphia-positive chronic myelogenous leukemia (CML-meg-BC), and one case of chronic myeloproliferative disorder (CMPD). Among them, an inversion of the long arm of chromosome 3 [inv(3)(q21q26)] was found in one AMKL patient with a normal platelet count. Chromosome change at band 3q26 was also found in one MDS patient without thrombocythemia. Furthermore, the long arm of chromosome 13, where rearrangements in myelofibrosis are clustered (13q12----q22) was seen in one MDS patient. Trisomoy of chromosome 19 was found in one AMKL patient and three CML-meg-BC patients. These findings indicate that cytogenetic abnormalities involving 3q26, 13q, and trisomy 19 are associated with hematologic neoplasia with megakaryocytic lineage in adult patients, although these abnormalities were not related to the survival of the patients. During the period of this study, two acute myelogenous leukemia patients (AML-M2 and AML-M5b) with chromosome rearrangements at band 3q21 and thrombocythemia were found, indicating that chromosome abnormality at band 3q21 is related to quantitative platelet dysfunction, whereas that at 3q26 is related to hematologic malignancies with a proliferation of megakaryocytic lineage.

Adolescent↗
PubMed1990

Long-term enhancement of synaptic transmission by synthetic mast cell degranulating peptide and its localization of binding sites in hippocampus.

A bee venom, mast-cell-degranulating (MCD) peptide, was synthesized by stepwise formation of the two disulfide bridges. This synthetic MCD peptide induced long-term potentiation (LTP) in the CA1 region of a hippocampus slice at concentrations ranging from 10(-7) to 10(-5) M. The potentiating effect of MCD was not lost by biotinylation of its N-terminus, and thus it became possible to investigate localization of its binding site at a cellular level in the hippocampus slice at a LTP-inducible concentration (1 microM). We found that even after brief application of N-biotinyl-MCD (1 microM) to perfusate, its presence was observed in pyramidal cell bodies in the CA1 and CA3 regions, but not in granule cells in the dentate gyrus of the hippocampus slice. This observation does not coincide with the localization of its high-affinity binding sites revealed by 125I-MCD binding, suggestive that another type(s) of MCD binding site, such as low-affinity binding sites, are present in the hippocampus.

Animals↗
PubMed1990

The antigenic structure of the human glycoprotein hormone alpha-subunit. I. Characterization of anti-alpha monoclonal antibodies.

The glycoprotein hormones CG, LH, FSH, and TSH are composed of two noncovalently linked subunits, alpha and beta. The beta-subunit confers hormone specificity, while the alpha-subunit is homologous within a species. To help in determining the antigenic structure of the common alpha-subunit, six monoclonal antibodies (mAbs) to the free or heterodimeric alpha-subunit of human (h) gonadotropic hormones have been prepared and, along with two previously isolated mAbs, have been characterized for binding specificity to alpha- and beta-subunits and the human glycoprotein hormones, CG, LH, FSH, and TSH. Each mAb was derived from hybidomas of FO myeloma cells fused with spleen cells from mice immunized with free alpha-subunit, hCG or hFSH. mAbs A101, A102, and E512 were specific for the alpha-subunit but showed the highest affinity for the intact hormone; K2.18, K94.6, E501, E502, and E511 were specific for free alpha. All of the antibodies inhibited binding of 125I-hCG to luteal membrane receptor, and 125I-labeled mAbs did not recognize hCG/receptor complex. Characterization by two-site binding assays using alpha, hCG, or hFSH as antigen revealed that all the mAbs bind to unique sites on alpha which may be overlapping, and which are modified in the intact hormone. The antigenic sites for mAbs E502, E511, and K2.18 are at least partially linear because they bind to reduced, carboxymethylated alpha.

Animals↗
PubMed1990

Suppression of tumor cell growth and mitogen response by aporphine alkaloids, dicentrine, glaucine, corydine, and apomorphine.

The aporphine alkaloids, dicentrine, glaucine, corydine, and apomorphine were shown to have inhibitory activity against several mouse tumor cell lines, leukemia P388 and L1210, melanoma B16, bladder cancer MBC2, and colon cancer Colon 26 in culture. These aporphine alkaloids also inhibited the mitogen-induced lymphocyte proliferation as well as the growth of IL-2 dependent CTLL2 line in a dose-dependent way. Of the four alkaloids apomorphine proved to be most potent in the inhibitory action. Apomorphine treatment resulted in some prolongation of survival time of the mice inoculated i.p. with P388, although its activity was not enough to meet the standard criterion for antitumor activity.

Adenocarcinoma↗
PubMed1990

Inhibitory effect of bisbenzylisoquinoline alkaloids on the quick death of mice treated with BCG/LPS.

Three bisbenzylisoqinoline alkaloids, chondocurine (Chon), berbamine (Ber), and cycleanine (Cyc) were tested for their protective effect on the quick death of mice primed with bacillus Calmette Guerin (BCG) and elicited with lipopolysaccharide (LPS). Seven-consecutive treatments with Chon or Cyc at a dose of 10 mg/kg following BCG priming resulted in significant improvement in the survival rate. A single dose of Chon also protected the BCG/LPS-treated mice from death if it was given immediately after, not 4 h after, LPS elicitation. These data show that bisbenzylisoquinoline alkaloids can protect mice from the lethal toxicity induced by the BCG/LPS combination treatment by inhibiting the priming with BCG or the elicitation with LPS.

Alkaloids↗