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Biomedical subjects

Y Higuchi

Publications and source records attributed to Y Higuchi.

At least 271 records · Page 15Linked to original sources
PubMed1985

[Experience in local hyperthermia with using ThermaTech 2000--second report].

In the use of hyperthermia treatment, it is apparent from the work of other investigators that only a proportion of large clinical neoplastic tumors of substantial size and deep location can be heated to adequate temperatures (over 42 degrees c). It is therefore of major significance that we have tested the concept that OK-432 can be used as an immunoheat potentiator. A ThermaTech 2000 was used as the radio-frequency generator at 13.56 MHz, including an ancillary computer in the thermometry unit. Minor response in advanced and metastatic tumors was observed in 3 of 3 evaluable patients using OK-432. With other anticancer drugs, no change was observed in 11 of 16 patients, and progressive disease in 5 of 16. However, OK-432 has severe side effects including chills & fever, therefore improved immunoheat potentiators are desirable.

Biological Products↗
PubMed1984

Sensitive and insensitive states of cultured glioma cells to glutamate damage.

Cytotoxic effects of L-glutamate and related compounds were investigated on rat glioma C6 cells in vitro. Within 12-24 h, addition of glutamate to the culture medium, resulted in degeneration of the C6 cells. The ED50 for glutamate-induced damage was about 4 mM. Seventeen structural analogues of glutamate, including agonists and antagonists for glutamate receptors as well as glutamate-uptake inhibitor, were examined concerning their toxicity on C6 cells. Among them, L-aminoadipic acid, DL-aminopimelic acid, DL-homocysteic acid, L-cysteic acid, quisqualic acid, L-glutamic acid diethyl ester and 2-amino-4-phosphonobutyric acid elicited similar degeneration at comparable concentrations. The D-isomer of glutamate was not cytotoxic. Following differentiation of C6 cells with 1 mM dibutyryl cyclic AMP or 3 mM sodium butyrate, they were no longer susceptible to L-glutamate and L-aminoadipate. C6 cells treated with 10 microM hydrocortisone, which is known to induce glutamine synthetase activity, were also resistant to L-glutamate, but not to L-aminoadipate. The decomposition of cellular DNA in glutamate-treated cultures was confirmed by flow cytometer analysis. The results demonstrate that the sensitivity of C6 cells to glutamate-induced cytotoxicity was modified by cellular metabolic conditions. This indicates that cultured glioma C6 cells are a useful model system to investigate the molecular mechanism of glutamate gliotoxicity in vitro.

2-Aminoadipic Acid↗
PubMed1984

Refined structure of cytochrome c3 at 1.8 A resolution.

The structure of cytochrome c3 from the sulfate-reducing bacterium Desulfovibrio vulgaris Miyazaki has been successfully refined at 1.8 A resolution. The crystallographic R factor is 0.176 for 9907 significant reflections. The isotropic temperature factors of individual atoms were refined and a total of 47 water molecules located on the difference map were incorporated in the refinement. The four heme groups are closely packed, with adjacent pairs of heme planes being nearly perpendicular to each other. The fifth and the sixth ligands of the heme iron atoms are histidine residues with N epsilon 2-Fe distances ranging from 1.88 A to 2.12 A. The histidine co-ordination to the heme iron is different for each heme group. The heme groups are all highly exposed to solvent, although the actual regions exposed differ among the hemes. The four heme groups are located in different environments, and the heme planes are deformed from planarity. The differences in the heme structures and their environments indicate that the four heme groups are non-equivalent. The chemical as well as the physical properties of cytochrome c3 should be interpreted in terms of the structural non-equivalence of the heme groups. The characteristic secondary structural non-equivalence of the heme groups. The characteristic secondary structures of the polypeptide chain of this molecule are three short alpha-helices, two short beta-strands and ten reverse turns.

Binding Sites↗
PubMed1984

Time course study of H-2 and other antigen expression by hybrids of a myeloma cell line with inflammatory macrophages.

The hybrids (the CANS lines) between inflammatory macrophages from C57BL/6N (B6) mice (H-2b) and BALB/c mouse (H-2d)-derived myeloma cell line NS1 in the early period after cell fusion showed no macrophage functions. However, most of the hybrids expressed these functions after prolonged cultivation accompanied with chromosome loss. In contrast, the hybrids initially displaying myeloma functions (kappa light chain production) lost this function when they exhibited macrophage functions. We studied the expression of cell-surface antigens in these hybrids and found that hybrids in the early period after cell fusion codominantly expressed both parental cell H-2 antigens (H-2Kb, H-2Kd, and H-2Dd) but not the H-2Db antigen. On the other hand, aged hybrids strongly expressed the H-2d antigen but lacked the H-2Kb antigen. Alternatively, these aged hybrids with macrophage functions expressed antigen(s) as detected with antiaged CANS-196 cell sera and asialo GM1 antigen, both of which were thought to be found exclusively on macrophages. Thus, the expression of cell-surface antigens in these hybrids was greatly altered after cell fusion.

Animals↗
PubMed1984

Expression of macrophage functions in hybrids of a myeloma cell line with inflammatory macrophages: evidence for negative control mechanisms in the expression of macrophage functions.

Mouse inflammatory macrophages from C57BL/6N mice were fused with BALB/c mouse-derived myeloma cells (the CANS series). The hybrids in the early period after cell fusion (8 weeks) showed no macrophage functions (chemotaxis, EA and EAC rosette-forming abilities, phagocytosis or lysozyme production). EA rosette-forming ability was observed when these hybrids were treated with trypsin, whereas other macrophage functions were not. After prolonged culture, the hybrids (12 clones of 13 randomly selected) showed all the macrophage functions along with chromosome loss. Myeloma cell functions (kappa light chain production) were found in the young hybrids soon after cell fusion but were absent in the aged hybrids. These results indicated that reexpression of macrophage properties, except for EA rosette-forming abilities, takes place after the loss of chromosomes or genes repressing the expression of macrophage functions.

Animals↗
PubMed1984

Serous papillary cystadenocarcinoma associated with alpha-fetoprotein production.

A 74-year-old woman with a right ovarian tumor had a high level of the serum tumor marker alpha-fetoprotein (AFP). After combination chemotherapy, the serum AFP level decreased significantly. Histopathologic study of surgically excised tumor tissue revealed a serous papillary cystadenocarcinoma. By the indirect immunoperoxidase technique, the AFP was stained in the cytoplasm of the differentiated tumor cells, showing papillary or tubular structures. Serial sections showed that the cells containing PAS-positive substances did not correspond to those producing AFP.

Aged↗
PubMed1983

Correlation between extent of metastatic lesions in whole body bone scintigraphy of patients with prostatic cancer and prostatic acid phosphatase in serum with Eiken PAP RIA kit.

The whole body bone scintigraphy of 13 patients whose prostatic cancer were histologically confirmed, was processed in four colors, and the bone metastases were quantitatively estimated. On the basis of this estimation, the extent of bone metastases was classified into 4 divisions (grades 0, 1, 2 and 3). And then, the correlation between the extent of bone metastases and prostatic acid phosphatase, acid phosphatase, and alkali phosphatase levels in serum were investigated.

Acid Phosphatase↗