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Biomedical subjects

T Hongo

Publications and source records attributed to T Hongo.

At least 109 records · Page 6Linked to original sources

Antibody to platelet activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine; PAF).

Specific antibodies to platelet activating factor (PAF) were prepared by immunizing rabbits with a hapten-bovine serum albumin (BSA) conjugate. As the hapten we used the synthetic PAF derivative which is resistant against enzymatic inactivation by plasma or tissues and which can bind to BSA through covalent bonding. Antibody activity was determined by an enzyme-linked immunosorbent assay (ELISA). Anti-PAF IgG reacted strongly with PAF. By means of the ELISA inhibition assay, we found that the antibody did not cross-react with phosphocholine, glycerophosphocholine, dilaurylglycerophosphocholine or PAF analogues which have ethanolamine-type polar head groups instead of choline group.

Animals↗

Low molecular weight factors displaying augmenting activity for human antibody production in vitro.

Dialyzable low molecular weight antibody-augmenting factors (LMAAF) were found in the culture supernatant of human tonsillar lymphocytes which were not stimulated by antigen and/or mitogen in vitro. Phagocyte-depleted nylon wool-adherent lymphocytes (M-Ny+ cells) were responsible for the release of the LMAAF. Marbrook's culture system was adopted to assay for the LMAAF. The M-Ny+ cells, which were cultured without antigen and/or without mitogen in the reservoir of Marbrook's diffusion culture vessel, released the LMAAF, which diffused across a dialysis membrane and significantly augmented the pokeweed mitogen (PWM)-induced plaque-forming cell (PFC) response of phagocyte-depleted lymphocytes (M-cells) cultured in the inner vessel. Phagocyte-depleted nylon wool-passed lymphocytes (M-Ny- cells) cultured in the reservoir could not augment the PWM-induced PFC response of the M- cells cultured in the inner vessel. The exuded fluid, which was the dialysate of the culture supernatant of the M-Ny+ cells ultrafiltrated with dialysis tubing, also enhanced the PFC response of M- cells cultured in 24-well multi plates. The exuded fluid also augmented the total IgM and IgG production of human tonsillar and peripheral blood lymphocytes measured by enzyme-linked immunosorbent assay (ELISA) systems. Gel filtration chromatography on Sephadex G-25 Superfine column showed that the LMAAF activity was demonstrated in the fractions corresponding to a molecular weight (m.w.) of 362 to 1,355 and a m.w. of 3,560 to 5,700, with a peak activity at about 4,500 dalton. The LMAAF were inactivated by treatment with proteinase K, but not by trypsin, alpha-chymotrypsin, RNase, and DNase, and were stable when treated at 56 C for 60 min. The dialysates of culture supernatants from two out of seven Epstein-Barr virus (EBV)-transformed M-Ny+ cell lines showed LMAAF-like activity. These results indicate that phagocyte-depleted nylon wool-adherent lymphocytes, possibly B cells, release low molecular weight factors displaying augmenting activity for human antibody production in vitro.

Antibody Formation↗

Minerals in plasma and urine and gustatory function tests for salt in a group of healthy young men.

Detection threshold for salt (NaCl) and discrimination between two levels of NaCl concentration (0.6 and 0.7%) in foods, and their relation to some selected biochemical parameters in plasma and urine (Zn, Na, K, Mg, Ca, Se for plasma and urine, Cu and retinol binding protein for plasma) were investigated in 15 healthy male college students. No subject failed to discriminate the NaCl concentrations in more than 50% of the tests. The rate of correct discrimination (RCD) was not associated with plasma Zn (P-Zn), plasma retinol binding protein (P-RBP), urinary potassium (U-K) or urinary sodium (U-Na), which significantly correlated with RCD in our previous study, while the detection threshold was significantly correlated with urinary Ca-Mg ratio (U-Ca/Mg), urinary Ca (U-Ca), U-Na, and urinary Mg. In the stepwise multiple regression analysis, U-Ca/Mg, plasma Ca, plasma Na, and RCD were selected as significant independent variables. These indicate that the status of minerals such as Na, Ca, and Mg is related to the gustatory function. One possible explanation for the discrepancy between the present and previous results is the elevated P-Zn and P-RBP levels in the present subjects.

Adult↗

[Anticancer drug sensitivity test using the short-term microplate culture and MTT dye reduction assay].

We have applied the MTT dye reduction assay to the anticancer drugs sensitivity test using short-term microplate cultures. The tumor cells were cultured with the anticancer drugs for 2 and 4 days. After culture, MTT dye was placed in each microwell and culture was carried out again for 4 more hours. The formazans generated by living cells were dissolved in acidified isopropyl alcohol and the absorbances of each well were measured at a wavelength of 540 nm. When tables of cytotoxicity indices classified into anticancer drugs, concentrations and durations of culture for each type of leukemic cell were made, it became possible to compare each drug and to select the effective ones. This assay is simple, precise, rapid, has no washing steps and is convenient for handling a large volume of material. We apply this assay in clinical practice.

Antineoplastic Agents↗

[Spectral EEG analysis in children treated with high-dose methotrexate].

During the use of a therapeutic regimen of high-dose methotrexate (HD-MTX) with leucovorin rescue in two cases of osteogenic sarcoma and malignant lymphoma without central nervous system (CNS) involvement, serial EEG monitoring before and after MTX infusion was performed with special reference to occipital basic activity. The EEGs were analyzed as to the power average spectrum using an ATAC-450 (NIHON KOHDEN). At 48 hours after the initiation of MTX, there was a transient but statistically significant slowing, such as a drop in the dominant frequency and a decrease in the alpha/theta ratio. Complete recovery of EEG changes occurred within one week. No clinical symptoms suggestive of CNS impairment were noted in either case. These data suggest that EEG alterations might be a reflection of subclinical CNS impairment. Therefore, serial EEGs might be a good early indicator for the detection of leukoencephalopathy in high-risk patients.

Bone Neoplasms↗

[Anticancer drug sensitivity test and its clinical evaluation in 15 cases of acute leukemia and lymphoma].

We carried out in vitro anticancer drug sensitivity tests a total of 24 times in 15 cases of childhood leukemias and lymphomas using the microplate culture and crystal violet staining method. We then compared them with the clinical effects. As a result, the in vitro efficacy rate at onset of cases was 40%, which was less than that for relapsed cases, which was 100%. Especially, cases of ALL at onset all failed. As for the relation between in vitro and in vivo effects, cases for which it was possible to make evaluation both in vitro and in vivo numbered 16. The results for these cases were; true positive rate, 71%; true negative rate, 50%; predictive accuracy, 69%. The true positive rate was higher than the usual rate. As for the efficiency of each anticancer drug, in vitro predictive accuracy for ADR, Ara-C and 4 HCP (CPM) was higher than for other drugs. From these results, it became clear that our method is very useful for the screening of effective anticancer drugs.

Acute Disease↗

Mercury-selenium interaction in workers exposed to elemental mercury vapor.

Mercury (Hg) and selenium (Se) levels were determined for erythrocytes, plasma and urine of 25 male and 29 female workers exposed to elemental mercury (Hgo) vapor. Interrelationship between the Hg levels and the Se levels was examined by the correlational analysis and the stepwise regression analysis. Indicators of Se status (erythrocyte Se levels, plasma Se levels and urinary Se levels) were closely intercorrelated; similarly, indicators of exposure to Hgo vapor (erythrocyte inorganic Hg levels, plasma Hg levels and urinary Hg levels) were significantly intercorrelated. Since plasma Hg level was one of the significant independent variables in determining the erythrocyte Se and plasma Se levels, Hgo vapor exposure was thought likely to influence the Se metabolism in workers. None of the Se status indicators were significant as determinants of the indicators of Hgo vapor exposure.

Adult↗

Elemental composition of ancient Japanese bones.

Excavated bones (rib) obtained from 50 sites in Japan were measured by ICP atomic emission spectrometry and atomic absorption spectrometry for concentration of 19 elements, including Al, B, Ca, Cd, Cr, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Sr, Ti, V and Zn. One hundred and forty-one specimens were classified into five groups according to Japanese prehistoric and historic eras (Jomon, Yayoi, Kofun, Kamakura and Muromachi, and Edo). The elements, with concentrations which showed no significant change with era were Al, B and Cr. Average concentrations of Ca were in the range 2-2.5 X 10(-1) g g-1 and those of P ranged from 1.1 to 1.3 X 10(-1) g g-1, indicating a well-preserved bone mineral matrix. The Ca/P ratio (mol/mol) was lowest in the Edo group--1.48 as compared with 1.54-1.66 in the other groups. Among the elements which showed changes with era were Pb, Fe, Co and Mn, all of which showed remarkably elevated concentrations in the Edo group. In addition to this unique elemental composition of Edo bones, samples from the Kofun era showed a completely different composition from those of other periods, i.e. they had the highest concentrations of Cd, Zn and Mg, and the lowest concentrations of Cu, K, Ni and Sr. The cause of the elevated Pb concentration in Edo bones is discussed in relation to human activities which may have led to environmental Pb pollution.

Bone and Bones↗

Complete median cleft of the upper lip and alveolus with holoprosencephaly.

A case of complete median cleft of the upper lip and alveolus with holoprosencephaly is presented. An 8-month-old girl was successfully treated by closure of the median upper lip. In addition, 9 patients who have undergone cheiloplasty of complete median cleft of the upper lip with holoprosencephaly reported in the Japanese literature, are reviewed.

Abnormalities, Multiple↗

Light-induced potential and current across a large bacteriorhodopsin-asolectin planar membrane stabilized on a polyacrylamide gel surface.

A phospholipid bilayer membrane was spread from an organic solvent solution between a polyacrylamide gel surface and an aqueous buffer solution. The membrane was quite similar to the conventional black lipid membrane, but was of a large size and was stable since it was supported on the gel surface. Bacteriorhodopsin, impregnated into the membrane, generated membrane potential and current upon illumination. The induced current was large, and this was attributed to the large area of the present membrane. Remarkable responses of the light-induced potential and current were also observed with a thick layer of organic solvent containing phospholipids. The effects of applied membrane potential, carbonylcyanide-m-chlorophenyl hydrazone (CCCP) and gramicidin were examined on these photoresponses. Steady-state current, which is due to protons flowing through the membrane, was enormously enhanced by applying membrane potential opposite to the photopotential or by adding gramicidin to the membrane-forming solution.

Acrylic Resins↗

[A new anticancer drug sensitivity test using the microplate culture and surviving tumor cell staining method].

We have developed a new anticancer drug sensitivity test using the short-term microplate culture and viable cell staining method, and the details of this method are reported. The tumor cells are cultured with the anticancer drugs for 2 days and 4 days. After culture, the microplate is centrifuged. The surviving tumor cells are fixed with ethanol and stained with crystal violet. After washing out the remaining crystal violet, 200 microliters of sodium lauryl sulfate is put into each microwell and the absorbance of each is measured. When we examined this method using leukemic cell lines, we found that the numbers of cells were in proportion to the absorbance, and that the surviving cells could be counted by the absorbance within the range of 0.4 to 1.7. On the assumption that the effective range is more than 60% of the cytotoxicity index (CI), tables of CI classified into drugs, concentrations and duration of culture for each leukemic cell line were made. With these tables, comparison of the anticancer drugs and subsequent selection of the effective ones became easier. This method is simple, rapid and convenient for handling a large volume of material. Its application to further clinical practice is therefore expected.

Antineoplastic Agents↗